AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 915 PM MDT FRI AUG 3 2007 .UPDATE...TO REMOVE FLASH FLOOD WATCH HEADLINE FOR SOUTHWEST COLORADO. SHOWER AND THUNDERSTORM DEVELOPMENT HAS BEEN SUPPRESSED THIS EVENING SO THE CHANCE OF HEAVY RAIN DIDN`T MATERIALIZE. HEAVIER SHOWERS AND THUNDERSTORMS DEVELOPED OVER THE TAVAPUTS PLATEAU IN NE UTAH AND NW COLORADO. DOPPLER INDICATING LOCAL HEAVY RAIN. THIS APPEARS TO BE ASSOCIATED WITH A SMALL VORTICITY MAXIMA AND AREA OF STRONG UPWARD MOTION PROJECTE BY RUC MODEL FOR THIS EVENING...BUT DISPLACE NORTH OF AREA RUC PREDICTED. && .SHORT TERM...TONIGHT THROUGH SUNDAY... CLOCKWISE FLOW AROUND AN UPPER HIGH CENTERED SOUTHEAST OF THE AREA CONTINUES TO STREAM DEEP SUBTROPICAL MOISTURE ACROSS EASTERN UTAH AND WESTERN COLORADO THIS AFTERNOON. THUNDERSTORMS HAVE DEVELOPED IN THE HEAT OF THE DAY WITH NUMEROUS STORMS FORMING OVER SAN JUAN COUNTY UTAH AND ACROSS WESTERN MONTROSE COUNTY SOUTH INTO MONTEZUMA COUNTY. AN EMBEDDED SHORTWAVE TROUGH NEAR THE FOUR CORNERS IS ENHANCING FORCING ACROSS THE SOUTH AND THIS WAVE IS PROGGED TO MOVE SLOWLY NORTHEAST OVER WESTERN COLORADO THROUGH TONIGHT. THIS WILL KEEP SHOWERS AND THUNDERSTORMS FOCUSED ACROSS THE SOUTH THROUGH THIS EVENING. AREAS OF HEAVIEST RAINFALL THE PAST 24 HOURS WERE ACROSS THE SAN JUAN MOUNTAINS AND WITH HEAVY RAIN POTENTIAL AGAIN TONIGHT HAVE HOISTED A FLASH FLOOD WATCH FOR SOUTHEAST UTAH AND SOUTH CENTRAL AND SOUTHWEST COLORADO. ENOUGH FLOW ALOFT TO MOVE STORMS ALONG BUT TRAINING STORMS WILL NEED TO BE MONITORED FOR FLOODING. ISOLATED TO SCATTERED NOCTURNAL SHOWERS AND THUNDERSTORMS EXPECTED LATE TONIGHT BUT THE HEAVY RAIN THREAT SHOULD DIMINISH. ANOTHER ROUND OF THUNDERSTORMS WILL OCCUR AGAIN SATURDAY AFTERNOON AND AGAIN SUNDAY WITH THE ATMOSPHERE REMAINING MOIST AND UNSTABLE. A TROUGH ALONG THE PACIFIC NORTHWEST COAST WILL FURTHER SUPPRESS THE HIGH CENTER TO THE SOUTHEAST AND MAY BRING A LITTLE DRIER AIR INTO EASTERN UTAH AND NORTHWEST COLORADO OVER THE WEEKEND. STORM MOTION MAY INCREASE A LITTLE AS WELL SO FLASH FLOOD THREAT SHOULD BE LESS. NO SIGNIFICANT CHANGE TO THE TEMPERATURE FORECAST WITH MAX AND MIN TEMPERATURES AROUND SEASONAL NORMALS. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY... EXTENDED FORECAST CONTINUES TO ADVERTISE LITTLE CHANGE WITH A FAIRLY MOIST PATTERN THROUGH MOST OF NEXT WEEK. MOIST SOUTHWEST FLOW WILL CONTINUE OVER THE CWA AS FLATTENED RIDGE REMAINS EAST OF THE CWA. HAVE KEPT MAINLY CHANCE POPS EACH DAY THROUGH MID-WEEK...WITH A POTENTIAL FOR LOCALLY HEAVY RAIN EACH AFTERNOON AND EVENING. BY MID- WEEK...TROUGH WILL DEEPEN TO OUR WEST ALLOWING DRIER AIR FROM THE WEST TO MOVE INTO THE AREA BY THURSDAY AND FRIDAY. AS A RESULT...HAVE CONTINUED TREND OF DECREASED POPS BY LATE WEEK. EXPECT NEAR NORMAL TEMPERATURES THROUGH THE PERIOD. && .AVIATION... UPPER LEVEL HIGH PRESSURE IS CENTERED SOUTHEAST OF THE AREA RESULTING IN A MOIST AND UNSTABLE SOUTHERLY FLOW OVER THE AREA. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS UNTIL ABOUT MIDNIGHT WILL PRODUCE SCATTERED MVFR TO ISOLATED IFR DUE TO REDUCED VISIBILITY AND LOW CEILINGS IN HEAVY RAIN ACROSS SOUTHEAST UTAH AND SOUTHWEST COLORADO. ELSEWHERE...LOCALIZED MVFR WITH SHOWERS AND THUNDERSTORMS EXPECTED. TYPICAL GUSTY AND ERRATIC THUNDERSTORM OUTFLOW WINDS WILL PLAGUE THE AREA AS WELL. VFR CONDITIONS TO DOMINATE AFTER MIDNIGHT INTO SATURDAY MORNING && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. $$ SHORT TERM...TAL/CJC LONG TERM...MPM AVIATION...TAL co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 229 PM MDT FRI AUG 3 2007 .SHORT TERM... (TONIGHT AND SAT) ...HEAVY RAIN/FLASH FLOOD POTENTIAL CONTINUES FOR NEXT 24 HOURS... CURRENTLY...MIDDLE AND UPPER LEVEL PATTERN HAS SHIFTED A LITTLE PER WATER VAPOR IMAGERY AND RUC MODEL ANALYSIS ANIMATION. HIGH PRESSURE IS NOW CENTERED OVER THE CNTRL/SRN PLAINS WITH SW-WLY FLOW OVER THE CNTRL ROCKIES. VERY MOIST AIR MASS STILL REMAINS TRAPPED OVER CO WITH 12Z/03 SOUNDING DATA SHOWING PRECIPITABLE WATER INDICES OF 150 TO NEAR 200 PERCENT ACROSS THE REGION. SURFACE DEW POINTS ARE IN THE 50S AND 60S ACROSS SERN CO. ALSO...RELATIVELY MOIST SURFACE DEW POINTS ARE IN THE MOUNTAINS AS LEADVILLE...APPROX 10K FT MSL...HAD DEW POINTS IN THE LOWER 50S...WHICH IS PRETTY HIGH FOR THAT ELEVATION. EARLY AFTN REGIONAL RADAR SHOWED A FEW SHOWERS AND TSTMS DEVELOPING ACROSS FAR WRN AND INTO N CNTRL CO...AND A FEW OVER THE OUR CWFA MOUNTAINS. THE GOOD NEWS IS THE FIRE DANGER ACROSS OUR CWFA IS PRETTY LOW RIGHT NOW. LATE THIS AFTN THROUGH TNGT...MUCH LIKE YDA AFTN AND EVE...TOUGH TO LOCATE ANY FEATURE/TRIGGER IN SATELLITE/MODEL DATA TO ENHANCE CONVECTION ACROSS OUR CWFA. PLENTY OF MOISTURE AND CONVECTIVE ENERGY JUST SITTING AROUND TO BE RELEASED. RUC40 AND MESOSCALE MODELS SHOWING SHOWERS AND TSTMS DEVELOPING OVER THE MOUNTAINS AND MOVING E-NEWD INTO ADJACENT HIGH VALLEYS AND I-25 CORRIDOR THIS AFTN AND TNGT. THE MAIN TSTM IMPACT WEATHER WILL BE HEAVY RAIN GIVEN H7-H5 SPECIFIC HUMIDITY VALUES OF 7-8 G/KG AND FREEZING LEVEL/WET BULB ZERO HEIGHTS OF 14K-17K FT MSL. SOME HAIL MAY OCCUR WITH MORE INTENSE TSTM UPDRAFTS...BUT MAINLY 1/2 INCH OR LESS IN DIAMETER. RAINFALL RATES OF 1-2 INCHES PER HOUR WILL BE POSSIBLE ACROSS THE MOUNTAINS AND I-25 CORRIDOR...ESPECIALLY WITH CELL TRAINING OR MERGERS. TSTM CELLS WILL BE MOVING A LITTLE FASTER(10-15KTS) COMPARED TO THE LAST FEW DAYS. SINCE THE CNTRL MOUNTAINS APPEAR TO HAVE THE HIGHEST POTENTIAL FOR SHOWER AND TSTM COVERAGE...WILL CONTINUE FLASH FLOOD WATCH FOR THAT AREA. HAVE DECIDED TO EXPAND FLASH FLOOD WATCH TO ALL OF OUR MOUNTAINS AND FREMONT COUNTY. ROCK AND MUD SLIDES HAVE OCCURRED IN LAKE AND CHAFFEE COUNTIES OVER THE PAST WEEKS. ACTUALLY...JUST ABOUT ANYWHERE IN THE MOUNTAINS AND I-25 CORRIDOR COULD HAVE SERIOUS HEAVY RAIN ISSUES...BUT TOUGH TO PINPOINT. OBVIOUSLY...WILDFIRE BURN SCARS WILL BE UNDER THE GUN TOO. WILL MAINTAIN HEAVY RAIN MENTION IN FORECAST FOR I-25 CORRIDOR AND WWD. MUCH OF THE SHOWER AND TSTM ACTIVITY WILL LIKELY EVOLVE INTO A MESOSCALE CONVECTION SYSTEM POSSIBLY IN NERN CO/WRN NE/NWR KS...WHICH COULD START TO SHOVE A FEW WEAK FRONTAL BOUNDARY TOWARDS SERN CO LATE TNGT OR EARLY SAT AM. SAT...WEAK MIDDLE TO UPPER LEVEL HIGH REMAINS OVER THE SRN PLAINS WITH SW-WLY FLOW OVER THE CNTRL ROCKIES. VERY MOIST AND UNSTABLE AIR MASS REMAINS IN PLACE FOR TSTM DEVELOPMENT MAINLY IN THE AFTN AND EVE. HEAVY RAIN AND FLASH FLOODING POTENTIAL CONTINUES TO BE THE MAIN TSTM IMPACT WEATHER GIVEN FREEZING LEVEL/WET BULB ZERO HEIGHTS OF 14K-17K FT MSL AND H7-H5 SPECIFIC HUMIDITY VALUES OF 6-8 G/KG. MESOSCALE MODELS CONTINUE TO SUPPORT SHOWER AND TSTM DEVELOPMENT OVER THE MOUNTAINS BY AROUND NOON AND THEN DRIFT EWD WITH THE MEAN CLOUD LAYER FLOW. THE SERN CO PLAINS WILL BE CHALLENGING GIVEN THE POTENTIAL OF A WEAK FRONTAL BOUNDARY MOVING THROUGH THE AREA. WRF HAS THIS FEATURE...BUT THE GFS DOES NOT. AS USUAL...IT ALL DEPENDS WHERE AND HOW THE NOCTURNAL MESOSCALE CONVECTIVE SYSTEM EVOLVES TNGT. ELY FLOW DEVELOPS ACROSS MUCH OF SERN CO SAT AFTN WITH CONVECTIVE PRECIPITATION BULLSEYES DEVELOPING AROUND TELLER/EL PASO COUNTIES WITH THE POTENTIAL FOR HEAVY RAIN. CERTAINLY IS DOABLE. WILL LET THE MIDNIGHT CREW RE-EVALUATE FOR A POSSIBLE FLASH FLOOD WATCH FOR SAT AFTN/EVE. MUCH OF THIS IMPACT WEATHER IS DRIVEN BY MESOSCALE FEATURE WHICH IS DIFFICULT TO FORECAST BEYOND 24 HOURS. METZE .LONG TERM... SATURDAY NIGHT THROUGH FRIDAY...MODELS FAIRLY CONSISTENT FROM RUN TO RUN IN THE EXTENDED PORTION WITH UPPER RIDGE EXPANDING TO THE SOUTHEAST. RETURN FLOW WILL CONTINUE TO PROVIDE DEEP MOISTURE PLUME THAT WILL SERVE UP DAILY CONVECTION. AT THE SAME TIME WITHIN THAT PLUME WILL BE THOSE PESKY IMPULSES THAT ARE TOUGH TO PREDICT. EACH ONE COULD ENHANCE MOUNTAIN CONVECTION THAT WILL IN TURN LEAD TO SLOW MOVING HEAVY RAINERS. GFS TRENDING TOWARD A PASSING IMPULSE EVERY OTHER DAY WITH BETTER PRECIP COVERAGE SAT...MON AND WED EVENINGS. RATHER THAN BOUNCE THE FORECAST AROUND STAYED CLOSE TO CURRENT FORECAST THAT IS CLOSE TO CLIMO FOR POPS. TEMPS LEVEL OFF THROUGH THE WEEK AND HELD ON TO CURRENT MAX TEMP GRIDS. -FORTUNE- && .AVIATION... ISOLATED TO SCATTERED TSTMS WILL AFFECT KCOS...KPUB...AND KALS THROUGH 06Z/03 TNGT. THE MAIN THREAT WILL BE HEAVY RAIN WITH IFR-MVFR VIS/CIGS...ERRATIC WINDS WITH POTENTIAL GUSTS UP TO 35KTS...AND PEA SIZE HAIL. METZE && .PUB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ058>068- 072>083-087. && $$ 17/21 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 200 PM MDT THU AUG 2 2007 .SHORT TERM... (TONIGHT AND FRIDAY) ...HEAVY RAIN/FLASH FLOOD POTENTIAL CONTINUES FOR NEXT 24 HOURS... CURRENTLY...WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES SHOWED A MIDDLE AND UPPER LEVEL HIGH PRESSURE SYSTEM CENTERED DIRECTLY OVER CO. PLENTY OF MOISTURE AROUND WITH 12Z/02 REGIONAL SOUNDING ANALYSES SHOWING PRECIPITABLE WATER INDICES AROUND 150 PERCENT ABOVE NORMAL. RELATIVELY HIGH LOW LEVEL MOISTURE IN PLACE WITH SURFACE DEW POINTS IN THE 60S GENERALLY UP AGAINST THE ERN CO MOUNTAINS...ALONG THE I-25 CORRIDOR AND EWD. TOUGH TO PICK OUT A FEATURE TO ENHANCE CONVECTION THIS AFTN...PRIMARILY LOOKING FOR PULSE TSTMS AND COULD POP UP JUST ABOUT ANYWHERE...LAUNCHING ADDITIONAL PULSE TSTMS. STORM SPOTTER REPORTS...RADAR ESTIMATES... AND SURFACE OBSERVATIONS SUGGESTED 2 TO 6 INCHES DID FALL AROUND THE WET AND SRN SANGRE DE CRISTO MOUNTAINS WED EVE THROUGH EARLY THU AM...MORE IMPORTANTLY IN EXTREME WRN PUEBLO COUNTY AROUND BEULAH. A STORM SPOTTER REPORTED 6.40 INCHES OF RAINFALL LAST WED EVE THROUGH EARLY THU AM. THE ANTECEDENT CONDITIONS ALREADY SUPPORT THE POTENTIAL FOR FLASH FLOODING IN THESE AREAS. EARLY AFTN REGIONAL RADAR SHOWED A FEW SHOWERS AND TSTMS TRYING TO GET GOING OVER THE PALMER DVD AND RATON MESA...BUT NOT MUCH ELSEWHERE. TEMPERATURES HAVE BEEN SLIGHTLY COOLER IN THE SERN CO PLAINS TODAY. LATE THIS AFTN AND TNGT...NOT MUCH CHANGE ANTICIPATED IN THE MIDDLE AND UPPER LEVEL FLOW PATTERN. VERY TOUGH CALL EXACTLY WHERE STORMS WILL FORM...IF AT ALL. NOT MUCH IN THE WAY OF A SYNOPTIC SCALE TRIGGER/FEATURE TO ENHANCE PRE-STORM CONVECTION. RUC40 AND MESOSCALE MODELS SUGGEST TSTMS POPPING UP JUST ABOUT ANYWHERE THIS AFTN THROUGH THIS EVE. HARD TO TRULY PINPOINT THESE LOCATIONS IN PULSE TSTM ENVIRONMENTS. CONDITIONS ARE ALL IN PLACE FOR MODERATE TO HEAVY RAINFALL...ESPECIALLY WITH CELL TRAINING AND MERGERS...MUCH LIKE LAST NIGHT. THIS IS SIMILAR TO BEING IN A ROOM OF PING-PONG BALLS ON MOUSETRAPS...THROWING A PING-PONG BALL INTO THE ROOM OF MOUSETRAPS AND TRYING TO FIGURE OUT WHERE AND WHICH PING-PONG BALLS WILL BE SENT FLYING BY EACH OF THE MOUSETRAPS. ANYWAY... MIDLEVEL STEERING CURRENTS ARE <5KTS...H7-H5 SPECIFIC HUMIDITY VALUES ARE 6-8 G/KG...AND FREEZING LEVEL/WET BULB ZERO HEIGHTS ARE 14K-17K FT MSL ALL SUPPORT THE HEAVY RAIN POTENTIAL...WHICH IS TYPICAL FOR CO IN AUG. INTENSE TSTMS COULD BE QUITE PROLIFIC HEAVY RAINERS WITH 1-3 INCHES PER HOUR.... ESPECIALLY IN TSTM MERGERS AND STORMS GETTING ANCHORED NEAR THE MOUNTAINS. THE LOCATION HAVING THE GREATEST POTENTIAL FOR FLASH FLOODING STILL LOOKS TO BE FROM AROUND PIKES PEAK THROUGH THE WET AND SANGRE DE CRISTO MOUNTAINS GIVEN THE COMBINATION OF HEAVY RAIN...COMPLEX TERRAIN...WILDFIRE BURN SCARS...AND ANTECEDENT CONDITIONS. ACTUALLY...OTHER AREAS ACROSS CNTRL...S CNTRL...E CNTRL...AND SE CO COULD SEE LOCALIZED HEAVY RAIN AND POSSIBLY FLOODING. IT JUST DEPENDS WHERE THESE PULSE TSTMS FORM...TRAVEL... AND TRIGGER ADDITIONAL TSTMS. PLANNING TO KEEP CURRENT FLASH FLOOD WATCH GOING FOR THE SAME AREA...AND THE MENTION OF HEAVY RAIN JUST ABOUT EVERYWHERE TNGT. TSTMS COULD END AROUND MIDNIGHT...BUT TOUGH CALL AND WILL MAINTAIN POTENTIAL AFTER MIDNIGHT. FRI...THERE IS A SLIGHT PATTERN CHANGE. THE MIDDLE AND UPPER LEVEL HIGH CENTERED OVER CO SHIFTS FURTHER E INTO THE CNTRL/SRN PLAINS. RELATIVELY DEEP S-SWLY FLOW DEVELOPS OVER CO. MOISTURE AND INSTABILITY REMAINS OVER THE CNTRL ROCKIES. MESOSCALE MODELS SUGGEST TSTMS TO BREAKOUT OVER THE MOUNTAINS AROUND NOON AND MOVE E-NEWD WITH THE FLOW. TSTM POTENTIAL IMPACT WEATHER WILL CONTINUE TO BE MODERATE TO HEAVY RAIN...SMALL HAIL...AND GUSTY WINDS. HEAVY RAIN CONTINUES TO BE THE GREATEST THREAT GIVEN H7-H5 SPECIFIC HUMIDITY VALUES OF 6-8 G/KG OVER THE MOUNTAINS AND FREEZING LEVEL/WET BULB ZERO HEIGHTS 14K-17K FT MSL. STORMS MIGHT BE MOVING A LITTLE FASTER FRI AFTN GIVEN H7-H5 FLOW OF 15-20KTS. AGAIN...HEAVY RAIN COULD OCCUR JUST ABOUT ANYWHERE...SO WILL ADD TO THE FORECAST. TEMPERATURES ARE A TOUCH WARMER THAN TODAY. METZE .LONG TERM... (FRIDAY NIGHT THROUGH THURSDAY) ...WET MONSOONAL PATTERN TO CONTINUE NEXT WEEK... NO SIGNIFICANT CHANGE IN THE LONG-TERM SYNOPSIS. MODELS IN FAIRLY GOOD CONSENSUS IN MAINTAINING THE PERSISTENT RIDGE OVER THE GULF AND S CENTRAL U.S. THIS WILL MAINTAIN A FLOW OF MOISTURE UP FROM MEXICO AND INTO THE 4 CORNERS REGION. HAVE MAINTAINED CHANCE POPS OVER THE WRN PART OF THE CWA AND LOWER/SLIGHT CHCE POPS OVR THE PLAINS. TEMPS WILL CONTINUE TO BE AROUND CLIMO. FRIDAY...CANNOT RULE OUT A STRONG STORM OR TWO...PARTICULARLY OVER THE PALMER DVD...BUT SHEAR DOES NOT LOOK AS GOOD AS IT HAD IN EARLIER MODEL RUNS. HEAVY RAINFALL WILL CONTINUE TO BE AN ISSUE ESPECIALLY WITH THE SATURATED SOIL CONDITIONS...HIGH PRECIP H2O...AND SLOW STORM MOVEMENT. WILL SEE A BIT OF A BREAK ON SAT...AS THE SHORTWAVE TO OUR NORTH MOVES INTO THE DAKOTAS AND WE SEE A BIT OF SHORTWAVE RIDGING BEHIND THIS SYSTEM. SHOULD BE FAIRLY SHORT-LIVED HOWEVER...AS WILL SEE A RETURN OF MONSOONAL FLOW ON SUNDAY. MONDAY MAY BE THE BEST BET FOR HEAVY RAINFALL...AS CO FALLS IN THE ENTRANCE REGION OF A 130+ KT JET STREAK OVER THE N PLAINS. LOW PRESSURE SHOULD DEEPEN SOMEWHERE INVOF THE SE PLAINS OR OK PANHANDLE...SETTING THE STAGE FOR FRONTOGENESIS OVR SERN CO. ALONG WITH THE CONTINUED PLUME OF MOISTURE MOVING TO THE N AND E THROUGH THE 4 CORNERS REGION...ALL THE INGREDIENTS MAY FALL IN PLACE FOR STRONG CONVECTIVE DEVELOPMENT. EC AND GFS NOW BOTH ON BOARD WITH IDEA OF CUTTING OFF THE BASE OF THE PACNW TROUGH...WHICH WILL KEEP THE FLOW OF MOISTURE FLOWING INTO CO THROUGH AT LEAST THE FIRST HALF OF THE WEEK. MAY FINALLY SEE SOME SIGNIFICANT DRYING AS THIS W COAST TROUGH FINALLY MOVES EWD LATE IN THE WEEK. ROSE && .AVIATION... ISOLATED TO SCATTERED TSTMS WILL AFFECT KCOS...KPUB...AND KALS THROUGH 06Z/03 TNGT. THE MAIN THREAT WILL BE HEAVY RAIN WITH IFR-MVFR VIS/CIGS...ERRATIC WINDS WITH POTENTIAL GUSTS UP TO 35KTS...AND PEA SIZE HAIL. METZE && .PUB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 11 PM MDT THIS EVENING FOR COZ072>081- 083-087. && $$ 17/44 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 1030 AM EDT FRI AUG 3 2007 .SYNOPSIS... A WARM AND VERY HUMID AIR MASS WILL BE OVER EASTERN NEW YORK AND WESTERN NEW ENGLAND ONE MORE DAY. A COLD FRONT WILL MOVE SLOWLY SOUTH AND EAST FROM THE SAINT LAWRENCE RIVER VALLEY DURING THE AFTERNOON. SCATTERED STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE ALONG...AND AHEAD OF THE COLD FRONT INTO THE EARLY EVENING. HIGH PRESSURE WILL BUILD IN FROM THE NORTHERN GREAT LAKES ON SATURDAY WITH SLIGHTLY COOLER AND DRY AIR FOR SATURDAY. THE SURFACE HIGH WILL CONTINUE TO PRODUCE NICE EARLY AUGUST WEATHER INTO SUNDAY. && .NEAR TERM /UNTIL MIDNIGHT SATURDAY/... MINOR UPDATED THIS MORNING. THUNDERSTORMS DEVELOPED OVER MADISON COUNTY NY AROUND 630 AM. THE RUC ANALYSIS INDICATED A WEAK SHORT WAVE MOVING ACROSS CENTRAL AND EASTERN NEW YORK. THE STORMS FORMED IN A LINE AS THEY MOVED DOWN THE MOHAWK VALLEY WITH FREQUENT LIGHTNING. THE STORMS HAVE WEAKEN SINCE 9 AM WITH NO OTHER ACTIVITY ACROSS FORECAST AREA AT THIS TIME. ADJUSTED POP/WX GRIDS TO ACCOUNT FOR EARLY CONVECTION. ADJUSTED HOURLY TEMPS AND DEW POINTS TO BETTER REFLECT OBSERVATIONS. THE THERMODYNAMICS CONTINUE TO LOOK IMPRESSIVE TODAY WITH THE APPROACHING COLD FRONT. THE KALB 12Z SOUNDING THIS MORNING IS LOADED WITH MUCAPE CAPE SITTING AT 2300 J/KG WITH A FORECAST SURFACE CAPE UP TO AROUND 3000 J/KG THIS AFTERNOON. 850-500 MB LAPSE RATE IS STEEP WITH 7.1 C/KM AND THE WET-BULB HEIGHT HAS DROPPED TO 11 KFT. THE WET-BULB HEIGHT IS EXPECTED TO DROP EVEN MORE AHEAD OF THE COLD FRONT DOWN TO 8.5 TO 9 KFT. EVEN THOUGH THE DYNAMICS ALOFT ARE NOT IMPRESSIVE WITH THE BEST DEEP LAYER SHEAR IS WELL NORTH OF THE REGION HAVE LIFT AND ABUNDANT INSTABILITY AND MOISTURE TO WORK WITH. KEPT ENHANCED WORDING IN WX GRIDS AND ZONES AND STRONG TO SEVERE STORMS IN OUR HAZARDOUS WEATHER OUTLOOK. WILL HAVE AN 18Z SOUNDING THIS AFTERNOON. && .SHORT TERM /MIDNIGHT SATURDAY THROUGH SUNDAY/... THE COLD AIR ADVECTION ASSOCIATED WITH THE FRONTAL PASSAGE DOES NOT KICK IN UNTIL AFTER 12Z SATURDAY. A MOIST BOUNDARY LAYER IS LEFT BEHIND BETWEEN 06Z-12Z WITH A WEAK SFC WIND GRADIENT. WE PLACED SOME PATCHY FOG IN THE VALLEY LOCATIONS. SATURDAY INTO SUNDAY...HIGH PRESSURE BUILDS IN FROM THE UPPER GREAT LAKES REGION ON SATURDAY. COLD AIR ADVECTION WILL BE ONGOING WITH H850 TEMPS FALLING TO AROUND 15C BY 18Z AT KALB. LOCATIONS SOUTH AND EAST SHOULD STILL SEE TEMPS CLOSE TO 90F. WE WENT 2-3 DEGREES CLOSER TO THE GFSMOS VALUES. SATURDAY NIGHT...MOSTLY CLEAR AND COOL CONDITIONS WILL BE ON TAP WITH THE SFC RIDGE BUILDING IN OVER UPSTATE NY. HUMIDITY LEVELS SHOULD BE QUITE COMFORTABLE WITH LOWS IN THE 50S IN THE VALLEYS AND M40S TO L50S IN THE HILLS AND MTNS. ANOTHER NICE DAY ON SUNDAY WITH THE HIGH SLIDING E/SE OFF THE ERN NEW ENGLAND COAST. SOME MID AND HIGH CLOUDS WILL APPROACH LATE IN THE DAY...AS A WARM FRONT BEGINS TO LIFT N/NE FROM THE UPPER MID ATLANTIC REGION. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... SUNDAY NIGHT...OVER RUNNING SHOWERS FROM A WEAK BAROCLINIC ZONE AHEAD OF A WARM FRONT MOVE IN FROM THE SOUTH. THE TIMING VARIES BETWEEN THE DETERMINISTIC MODELS. WE PLACED A CHANCE OF SHOWERS IN AFTER MIDNIGHT ACROSS THE REGION. CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE ON MONDAY...AS THE WARM FRONT LIFTS NORTHEAST. IT APPEARS THE FCST AREA WILL GET INTO A WARM SECTOR LATE MONDAY INTO TUESDAY. THE TIMING OF A COLD FRONT AND AN APPROACHING WAVE IS TRICKY TUESDAY INTO WEDNESDAY. IT LOOKS LIKE THE COLD FRONT WILL TRY TO MOVE ACROSS THE REGION TUESDAY PM INTO THE EVENING WITH SOME STRONG THUNDERSTORMS POSSIBLE. WE ARE HIGHLIGHTED IN THE DAY 4-8 GRAPHIC. CANADIAN HIGH PRESSURE MAY BRIEFLY BUILD IN BY THE MID WEEK. NO CHANGES WERE MADE BEYOND MONDAY. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... PATCHY MVFR/IFR IN BR EXPECTED THROUGH 13Z...OTHERWISE EXPECT AREAS OF HAZE...BUT VSBYS SHOULD HOLD IN THE VFR RANGE THROUGH EARLY TONIGHT. SCATTERED SHOWERS/TSTMS MAY PRODUCE LOCALIZED MVFR/IFR CONDITIONS THIS AFTERNOON INTO EARLY TONIGHT. AREAS OF MVFR/IFR SHOULD THEN REDEVELOP LATER TONIGHT...ESPECIALLY IN ANY AREAS THAT RECEIVE ANTECEDENT RAINFALL. AS FOR TSTM POTENTIAL...LOOKS LIKE CHANCES INCREASE AFTER 17Z/FRI...WITH HIGHEST PROBABILITIES FROM KALB NORTHWARD TO KGFL. THERE MAY BE 2 SEPARATE ROUNDS OF TSTMS...ONE WITH A PREFRONTAL TROUGH...BETWEEN 17Z-22Z/FRI...THEN PERHAPS WITH THE ACTUAL COLD FRONT...BETWEEN 00Z-04Z/SAT. THIS AFTERNOON...THE AREAL COVERAGE SHOULD REMAIN ISOLATED TO SCATTERED...AND THUS...WILL ONLY INCLUDE A CB APPENDAGE IN 06Z/FRI TAF ISSUANCE. WILL THEN INCLUDE A VCSH AND CB APPENDAGE TOWARD AND AFTER 00Z/SAT...DUE TO POSSIBLE GREATER AREAL COVERAGE OF CONVECTION WITH COLD FRONT. AS FOR WINDS...OUTSIDE OF TSTMS...EXPECT DIRECTION TO REMAIN 170-200 THROUGH THE MORNING...AT 5-10 KT...THEN VEER SLIGHTLY INTO A 200-230 DIRECTION AT 8-12 KT THIS AFTERNOON. WINDS WILL THEN BECOME LIGHT/VARIABLE AFTER 00Z/SAT...BEFORE BECOMING NW TO N AFTER MIDNIGHT/SAT. WINDS IN AND NEAR ANY TSTMS MAY BE MUCH STRONGER IN GUSTS...AND VARIABLE IN DIRECTION. OUTLOOK... SAT AND SUN...VFR CONDITIONS WITH NO SIGNIFICANT WEATHER EXPECTED AT THIS TIME. SUN NIGHT THRU TUE...VFR...MVFR POSSIBLE...WITH A CHANCE OF SHOWERS AND THUNDERSTORMS. && .FIRE WEATHER... A COLD FRONT WILL APPROACH THE REGION LATE THIS AFTERNOON...AND PASS THROUGH THE REGION TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THIS FRONT. WARM BUT LESS HUMID CONDITIONS WILL THEN FILTER INTO THE REGION FROM THE NORTHWEST ON SATURDAY INTO SUNDAY. RELATIVE HUMIDITIES WILL FALL INTO THE 40 TO 55 PERCENT RANGE THIS AFTERNOON...WITH THE LOWEST VALUES WITHIN VALLEY LOCATIONS. THE HUMIDITY WILL RECOVER INTO THE 90 TO 100 PERCENT RANGE TONIGHT. RELATIVE HUMIDITIES WILL THEN FALL SATURDAY AFTERNOON INTO THE 35 TO 45 PERCENT RANGE...WITH THE LOWEST VALUES EXPECTED ACROSS THE LOWER AND MID HUDSON VALLEY. WINDS WILL BE FROM THE SOUTH TO SOUTHWEST TODAY...WITH SPEEDS OF 5 TO 10 MPH. WINDS WILL BE LIGHT AND VARIABLE TONIGHT...BEFORE SHIFTING INTO THE WEST TO NORTHWEST ON SATURDAY. WIND SPEEDS SATURDAY AFTERNOON WILL RANGE FROM 8 TO 12 MPH. HAINES INDICES WILL RANGE FROM 4 TO 5 THIS AFTERNOON...AND INCREASE TO BETWEEN 5 AND 6 SATURDAY AFTERNOON...AS DEEPER MIXING DEVELOPS IN THE WAKE OF THE COLD FRONT. && .HYDROLOGY... A COLD FRONT WILL MOVE THROUGH A VERY UNSTABLE AND MOIST AIRMASS THIS AFTERNOON AND EVENING...TRIGGERING SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN STEM RIVERS ARE AT NORMAL TO BELOW NORMAL LEVELS FOR EARLY AUGUST...SO THE STORMS SHOULD HAVE LITTLE IF ANY IMPACT ON THEM. HOWEVER...INDIVIDUAL STORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS WHICH MAY LEAD TO SOME MINOR NUISANCE FLOODING. THE COLD FRONTAL BOUNDARY WILL STALL WELL TO OUR SOUTH ACROSS THE MID ATLANTIC REGION. A DRIER AND COOLER AIRMASS WILL FILTER INTO OUR AREA OVER THE WEEKEND WITH HIGH PRESSURE BUILDING IN. HOWEVER WARM...HUMID AND UNSETTLED WEATHER WILL RETURN EARLY NEXT WEEK AS THE STALLED BOUNDARY MOVES NORTHWARD AS A WARM FRONT MONDAY. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1006 PM EDT FRI AUG 3 2007 ...FLOODING RAINS STILL POSSIBLE ACROSS SOUTH COASTAL SOUTH CAROLINA AND THE SAVANNAH METRO AREA... ...TORNADO/WATERSPOUT RISK SLOWLY INCREASING ALONG THE CHARLESTON AND COLLETON COUNTY COASTS... .SYNOPSIS... A WARM FRONT WILL SLOWLY DRIFT NORTH ACROSS THE AREA TONIGHT AND SATURDAY. AN AREA OF LOW PRESSURE ALONG THE FRONT WILL SHIFT NORTHEAST THROUGH SATURDAY. A LOW PRESSURE TROUGH WILL REMAIN ACROSS THE AREA THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... LOW PRES CONTINUES TO MEANDER BTWN VDI AND AMG THIS EVNG WITH WMFNT EXTENDING E/NE THROUGH HINESVILLE TO TYBEE ISLAND THEN TURNING SHARPLY E ACROSS THE WATERS OFF BEAUFORT COUNTY. THE NOSE OF A 30 KT LLJ IN THE 925-850MB LYR REMAINS ORTHOGONAL THE WMFNT OFF BEAUFORT COUNTY AND IS SUPPORTING A RATHER CONCENTRATED AREA OF DEEP CONVECTION ALONG AND JUST OFF THE FAR LWR SC COAST. SHORT TERM MODELS INDICATE THERE WL BE A CONTINUED INTERACTION BTWN THE LLJ AND THE WMFNT UNDERNEATH A POCKET OF UPR LVL DIFLUENCE THROUGH SUNRISE. THIS SUGGESTS THE RAIN AREA OFF BEAUFORT WL SLOWLY EXPAND IN COVERAGE AND INTENSITY THROUGH THE NGT WITH A CONTINUED RISK FOR HVY RAIN. THIS IS WELL SUPPORTED BY THE LATEST RUC AND SREF ENSEMBLE GUIDANCE. WL MAINTAIN THE FLOOD WATCH THROUGH 8 AM FOR ALL SC COASTAL ZONES WHICH INCLUDES THE CHARLESTON METRO AREA. SUSPECT THE RISK FOR HVY RAIN IS DIMINISHING ACROSS MUCH OF SE GA WITH DRIER AIR BEGINNING TO FILTER IN ALOFT...THUS WL CANCEL THE FLOOD WATCH FOR MOST OF OUR GA ZONES. THE ONLY EXCEPTION WL BE INLAND/COASTAL CHATHAM COUNTY WHERE THE FLOOD WATCH WL CONTINUE. WE ARE JUST NOT COMPLETELY CONVINCED THAT THE RISK FOR HVY RAIN AND FLOODING HAS ENDED IN CHATHAM COUNTY...ESPECIALLY SINCE THE SAVANNAH METRO AREA IS PRONE TO SVR URBAN FLOODING. THE CORE OF 0-1KM HELICITY ON THE ORDER OF 300 M2/S2 IS SLOWLY WORKING ITS WAY UP THE LWR SC COAST AS THE WMFNT BUCKLES N. ALTHOUGH THE TORNADO/WATERSPOUT RISK IS DIMINISHING ACROSS BEAUFORT COUNTY...ANOTHER ENHANCED TORNADO AREA COULD DVLP ALONG COASTAL COLLETON AND CHARLESTON COUNTIES OVR THE NXT FEW HRS AS A NOSE OF 1500 J/KG OF SBCAPE NUDGES IN FROM THE SE. A TORNADO WRNG WAS ISSUED EARLIER FOR BEAUFORT COUNTY WHERE TWO STRONG CYCLONIC COUPLETS WERE DETECTED BY THE KCLX RADAR NEAR HILTON HEAD ISLAND. NO DAMAGE HAS BEEN REPORTED SO FAR PER A CONF CALL WITH BEAUFORT COUNTY EMERGENCY MANAGER. WL UPDATE THE GRIDS SHORTLY CUT POPS BACK INTO THE CHANCE CATEGORY FOR MUCH OF INTERIOR SE GA. WL MAINTAIN LIKELY-CATEGORICAL POPS ELSEWHERE WITH THE HIGHEST GRIDDED POPS ACROSS CHARLESTON AND COASTAL COLLETON COUNTIES. ONLY MINOR TWEAKS TO TEMPS AND CLOUD COVER WL BE MADE. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... 35 KT LLVL JET AHEAD OF THE 850 MB LOW CENTER PROGGED TO BE JUST OFFSHORE SAT MORNING...WITH THE STRONGEST OMEGA TO BE RIGHT ALONG THE COAST. ISENTROPIC ASCENT EXPECTED TO CONTINUE ACROSS MUCH OF THE AREA WITH THE HEAVIEST RAINFALL ALONG THE COAST WHERE DIVERGENT JET REGION...850 MB JET...AND THETA-E TONGUE COINCIDE. SOME BREAKS ARE POSSIBLE IN CLOUD COVER SAT...ESPECIALLY WESTERN SECTIONS...THUS A FEW MORE THUNDERSTORMS ARE POSSIBLE THAN TODAY. CONVECTIVE PARAMETERS DO NOT LOOK CONDUCIVE TO ORGANIZED SEVERE STORMS...ALTHOUGH A FEW WIND PRODUCERS ARE POSSIBLE. TEMPS ARE AGAIN TRICKY DUE TO THE CLOUD COVER AND RAIN. DROPPED TEMPS WELL BELOW MAV GUIDANCE ACROSS THE TRI-COUNTY AREA AND CLOSER TO THE COAST. INLAND GA COULD REACH 90 IN A FEW SPOTS. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE FRONTAL BOUNDARY IS EXPECTED TO SHIFT FARTHER OFF THE COAST SATURDAY NIGHT INTO SUNDAY...TAKING MUCH OF THE DEEP MOISTURE WITH IT. WHILE WEAK TROUGHING WILL PERSIST AT THE SURFACE THROUGH THE UPCOMING WEEK...UPPER LEVEL RIDGING WILL BUILD ACROSS THE AREA FROM THE DEEP SOUTH. A MID-LEVEL DOWNSLOPE FLOW COMBINED WITH STRONG SUBSIDENCE ALOFT AND RISING THICKNESS VALUES WILL RESULT IN VERY WARM TEMPERATURES DURING MUCH OF THE LONG TERM PERIOD. MOS GUIDANCE AND THICKNESS VALUES WOULD SUGGEST HIGHS REACHING THE UPPER 90S TO AROUND 100 IN MANY LOCATIONS AWAY FROM THE COAST THROUGH WEDNESDAY...HOWEVER GIVEN THE MOIST SOILS WILL KNOCK A FEW DEGREES OFF THOSE VALUES...AT LEAST EARLY ON IN THE LONG TERM PERIOD. OF EVEN GREATER CONCERN ARE HEAT INDEX VALUES...WHICH COULD REACH HEAT ADVISORY CRITERIA AS EARLY AS MONDAY...BUT MORE LIKELY FROM TUESDAY THROUGH FRIDAY AS LOW LEVEL MOISTURE BEGINS TO RETURN. PRECIPITATION CHANCES WILL ALSO DECREASE SIGNIFICANTLY BEGINNING SATURDAY NIGHT. DRIER AIR AS A RESULT OF THE DOWNSLOPE FLOW WILL GENERALLY KEEP MOST AREAS FREE OF ANY SHOWER ACTIVITY ON SUNDAY AND MONDAY...EXCEPT FOR PERHAPS SOME ISOLATED CONVECTION ACROSS FAR SOUTHERN AREAS SUNDAY AFTERNOON DUE TO THE PROXIMITY OF THE DEPARTING FRONT. A GRADUAL INCREASE IN LOW LEVEL MOISTURE COULD BRING ISOLATED CONVECTION TO THE FORECAST AREA TUESDAY THROUGH FRIDAY DURING THE AFTERNOON/EVENING HOURS. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... RAIN WILL CONTINUE TO BE AN ISSUE AT BOTH TERMINALS THIS EVENING AND INTO TONIGHT. EXPECT BRIEF PERIODS OF MVFR VSBYS AND CIGS ESPECIALLY AS THE RAIN IS OCCURRING. THE THREAT OF RAIN SHOULD END OVER THE SAV TERM BY LATE TONIGHT. THE CHS TERMINAL WILL SEE THE RAIN A BIT LONGER DUE TO THE LOW PRESSURE SYSTEM PUSHING SLOWLY TO THE NORTHEAST. MVFR CIGS APPEAR TO BE THE PRIMARY CONCERN TONIGHT AS CLOUD COVER IS EXPECTED TO REMAIN OVER THE AREA. THERE IS A CHANCE THAT CLOUDS COULD BREAK LATE TONIGHT ALLOWING FOR A SMALL WINDOW OF REDUCED VSBYS BETWEEN 6Z AND 12Z FOR BOTH TERMINALS. GIVEN THE AMOUNT OF MOISTURE AT THE SFC FROM RAINFALL TODAY...REDUCED VSBYS ARE POSSIBLE IF CLOUDS BREAK. CONDITIONS SHOULD IMPROVE TO VFR TOMORROW MORNING AS A DOWNSLOPING WEST WIND DEVELOPS BEHIND THE LOW PRESSURE SYSTEM. EXTENDED AVIATION OUTLOOK...A POTENTIAL FOR PERIODS OF MVFR OR LOWER CONDITIONS IN/NEAR SHOWERS/THUNDERSTORMS THROUGH SATURDAY. MAINLY VFR CONDITIONS ARE EXPECTED THEREAFTER THROUGH THE MIDDLE OF NEXT WEEK. && .MARINE... WL NEED TO MAKE SOME FAIRLY SIGNIFICANT CHANGES TO THE FCST THIS EVNG...MAINLY TO ACCOUNT FOR WNDS N OF THE WMFNT AND HIGHER THAN XPCTD WNDS S OF THE WMFNT. NO HEADLINES ARE XPCTD ATTM. THERE WL BE A CONTINUED RISK FOR WATERSPOUTS ACROSS MAINLY THE SC WTRS OVR THE NXT FEW HRS. THE SURFACE PRESSURE GRADIENT MAY TIGHTEN WITH A SOUTHWEST FLOW IN PLACE SATURDAY NIGHT...WITH WINDS UP TO 15 KT ACROSS THE NEAR SHORE WATERS AND 15-20 KT ACROSS THE OUTER GEORGIA WATERS. A WEAK PRESSURE GRADIENT SUNDAY THROUGH WEDNESDAY WILL GENERALLY KEEP WINDS UNDER 15 KT AND SEAS LESS THAN 4 FT. && .EQUIPMENT... THE KCLX RADAR CONTINUES TO UNDERESTIMATE PRECIPITATION AMOUNTS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FLOOD WATCH UNTIL 8 AM EDT SATURDAY FOR GAZ118-119. SC...FLOOD WATCH UNTIL 8 AM EDT SATURDAY FOR SCZ048>051. MARINE...NONE. && $$ ST ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 758 PM EDT FRI AUG 3 2007 ...ENHANCED TORNADO/WATERSPOUT RISK FROM TYBEE ISLAND TO BEAUFORT OVER THE NEXT FEW HOURS... .SYNOPSIS... A WARM FRONT WILL SLOWLY DRIFT NORTH ACROSS THE AREA TONIGHT AND SATURDAY. AN AREA OF LOW PRESSURE ALONG THE FRONT WILL SHIFT NORTHEAST THROUGH SATURDAY. A LOW PRESSURE TROUGH WILL REMAIN ACROSS THE AREA THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... MESOSCALE UPDATE... EARLY EVNG SFC ANALYSIS SHOWS WEAK LOW PRES SPINNING BTWN VDI AND AMG WITH A WMFNT BISECTING SE GA AND XTNDG E INTO THE COASTAL WTRS OFF OF BEAUFORT COUNTY. THE INITIAL WAVE WHICH MOVED UP THE FNT EARLIER IN THE AFTN HAS EXITED OFF THE MIDDLE SC COAST AND NLY FLOW BEHIND THE WAVE HAS PUSHED THE FNT S OF EDISTO BEACH AND ORIENTED IT MORE W-E. KCLX VWP SHOWS THE NOSE OF THE 925MB LLJ IS BECMG MORE ORTHOGONAL TO THE FNT WITH TIME WITH STRONG 850MB MOISTURE TRANSPORT NOTED IN THE LATEST RUC ANALYSIS. THUS ITS NO SURPRISE THAT NUMEROUS HEAVY CONVECTIVE CELLS HAVE RECENTLY DVLPD ALONG THE N GA COAST FROM SAVANNAH TROUGH THROUGH SAINT CATHERINES ISLAND...MAINLY IN RESPONSE TO THIS INTERACTION WITH THE LLJ AND THE SFC WMFNT. 0-1KM HELICITIES HAVE RECENTLY JUMPED TO 300-350 M2/S2 IN THE BEAUFORT AREA WITH SBCAPES AS HIGH AS 1500 J/KG NOSING IN FROM THE SE JUST OFF TYBEE ISLAND. WE ARE WATCHING CELLS DVLPG ALONG THE N GA COAST VERY CAREFULLY FOR SIGNS OF ROTATION AS CONDITIONS APPEAR FAVORABLE FOR WATERSPOUT FORMATION. ANY WATERSPOUTS THAT DVLP JUST OFF THE COAST HAVE THE POTENTIAL TO MOVE INLAND AS TORNADOES THUS THERE WL BE AN ENHANCED TORNADO/WATERSPOUT RISK FROM TYBEE ISLAND UP THROUGH BEAUFORT COUNTY FOR THE NXT FEW HRS. THE LATEST SHORT TERM MODEL GUIDANCE STILL SUGGESTS A REASONABLY HIGH RISK FOR FLOODING THROUGH NGT AS THE LLJ CONTINUES TO INTERACT WITH THE WMFNT NOW XTNDG W-E ACROSS SE GA WITH PWATS AS HIGH AS 2.50 INCHES. THE FLOOD WATCH WL CONTINUE. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... 35 KT LLVL JET AHEAD OF THE 850 MB LOW CENTER PROGGED TO BE JUST OFFSHORE SAT MORNING...WITH THE STRONGEST OMEGA TO BE RIGHT ALONG THE COAST. ISENTROPIC ASCENT EXPECTED TO CONTINUE ACROSS MUCH OF THE AREA WITH THE HEAVIEST RAINFALL ALONG THE COAST WHERE DIVERGENT JET REGION...850 MB JET...AND THETA-E TONGUE COINCIDE. SOME BREAKS ARE POSSIBLE IN CLOUD COVER SAT...ESPECIALLY WESTERN SECTIONS...THUS A FEW MORE THUNDERSTORMS ARE POSSIBLE THAN TODAY. CONVECTIVE PARAMETERS DO NOT LOOK CONDUCIVE TO ORGANIZED SEVERE STORMS...ALTHOUGH A FEW WIND PRODUCERS ARE POSSIBLE. TEMPS ARE AGAIN TRICKY DUE TO THE CLOUD COVER AND RAIN. DROPPED TEMPS WELL BELOW MAV GUIDANCE ACROSS THE TRI-COUNTY AREA AND CLOSER TO THE COAST. INLAND GA COULD REACH 90 IN A FEW SPOTS. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE FRONTAL BOUNDARY IS EXPECTED TO SHIFT FARTHER OFF THE COAST SATURDAY NIGHT INTO SUNDAY...TAKING MUCH OF THE DEEP MOISTURE WITH IT. WHILE WEAK TROUGHING WILL PERSIST AT THE SURFACE THROUGH THE UPCOMING WEEK...UPPER LEVEL RIDGING WILL BUILD ACROSS THE AREA FROM THE DEEP SOUTH. A MID-LEVEL DOWNSLOPE FLOW COMBINED WITH STRONG SUBSIDENCE ALOFT AND RISING THICKNESS VALUES WILL RESULT IN VERY WARM TEMPERATURES DURING MUCH OF THE LONG TERM PERIOD. MOS GUIDANCE AND THICKNESS VALUES WOULD SUGGEST HIGHS REACHING THE UPPER 90S TO AROUND 100 IN MANY LOCATIONS AWAY FROM THE COAST THROUGH WEDNESDAY...HOWEVER GIVEN THE MOIST SOILS WILL KNOCK A FEW DEGREES OFF THOSE VALUES...AT LEAST EARLY ON IN THE LONG TERM PERIOD. OF EVEN GREATER CONCERN ARE HEAT INDEX VALUES...WHICH COULD REACH HEAT ADVISORY CRITERIA AS EARLY AS MONDAY...BUT MORE LIKELY FROM TUESDAY THROUGH FRIDAY AS LOW LEVEL MOISTURE BEGINS TO RETURN. PRECIPITATION CHANCES WILL ALSO DECREASE SIGNIFICANTLY BEGINNING SATURDAY NIGHT. DRIER AIR AS A RESULT OF THE DOWNSLOPE FLOW WILL GENERALLY KEEP MOST AREAS FREE OF ANY SHOWER ACTIVITY ON SUNDAY AND MONDAY...EXCEPT FOR PERHAPS SOME ISOLATED CONVECTION ACROSS FAR SOUTHERN AREAS SUNDAY AFTERNOON DUE TO THE PROXIMITY OF THE DEPARTING FRONT. A GRADUAL INCREASE IN LOW LEVEL MOISTURE COULD BRING ISOLATED CONVECTION TO THE FORECAST AREA TUESDAY THROUGH FRIDAY DURING THE AFTERNOON/EVENING HOURS. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... RAIN WILL CONTINUE TO BE AN ISSUE AT BOTH TERMINALS THIS EVENING AND INTO TONIGHT. EXPECT BRIEF PERIODS OF MVFR VSBYS AND CIGS ESPECIALLY AS THE RAIN IS OCCURRING. THE THREAT OF RAIN SHOULD END OVER THE SAV TERM BY LATE TONIGHT. THE CHS TERMINAL WILL SEE THE RAIN A BIT LONGER DUE TO THE LOW PRESSURE SYSTEM PUSHING SLOWLY TO THE NORTHEAST. MVFR CIGS APPEAR TO BE THE PRIMARY CONCERN TONIGHT AS CLOUD COVER IS EXPECTED TO REMAIN OVER THE AREA. THERE IS A CHANCE THAT CLOUDS COULD BREAK LATE TONIGHT ALLOWING FOR A SMALL WINDOW OF REDUCED VSBYS BETWEEN 6Z AND 12Z FOR BOTH TERMINALS. GIVEN THE AMOUNT OF MOISTURE AT THE SFC FROM RAINFALL TODAY...REDUCED VSBYS ARE POSSIBLE IF CLOUDS BREAK. CONDITIONS SHOULD IMPROVE TO VFR TOMORROW MORNING AS A DOWNSLOPING WEST WIND DEVELOPS BEHIND THE LOW PRESSURE SYSTEM. EXTENDED AVIATION OUTLOOK...A POTENTIAL FOR PERIODS OF MVFR OR LOWER CONDITIONS IN/NEAR SHOWERS/THUNDERSTORMS THROUGH SATURDAY. MAINLY VFR CONDITIONS ARE EXPECTED THEREAFTER THROUGH THE MIDDLE OF NEXT WEEK. && .MARINE... WINDS HAVE GENERALLY BEEN VARIABLE ACROSS THE NRN TWO-THIRDS OF THE WATERS BUT SOLIDLY SE ACROSS SRN AREAS. WINDS HAVE SLOWLY INCREASED AT 41008 THIS AFTERNOON WITH SEAS RESPONDING AS WELL...WITH 3 FT NOW BEING REPORTED AT R2 TOWER AND 41008. WINDS SHOULD SLOWLY VEER TONIGHT AS THE WARM FRONT SHIFTS A BIT NORTH WITH INCREASE IN SPEEDS NEAR THE COAST AS LLVL PRES GRADIENT INCREASES. WIDESPREAD RAIN SHOWERS WILL OCCASIONALLY MIX SOME 20-25 KT WINDS GUSTS DOWN FROM THE LLVL JET. THE SURFACE PRESSURE GRADIENT MAY TIGHTEN WITH A SOUTHWEST FLOW IN PLACE SATURDAY NIGHT...WITH WINDS UP TO 15 KT ACROSS THE NEAR SHORE WATERS AND 15-20 KT ACROSS THE OUTER GEORGIA WATERS. A WEAK PRESSURE GRADIENT SUNDAY THROUGH WEDNESDAY WILL GENERALLY KEEP WINDS UNDER 15 KT AND SEAS LESS THAN 4 FT. && .EQUIPMENT... THE KCLX RADAR CONTINUES TO UNDERESTIMATE PRECIPITATION AMOUNTS. THIS MAY CHANGE NOW THAT DEEPER CONVECTION IS BEGINNING TO DVLP OFF THE COAST. THERE ARE NO PLANS TO SWITCH TO A TROPICAL Z/R RELATIONSHIP ATTM. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FLOOD WATCH THROUGH SATURDAY MORNING FOR GAZ116>119-137>141. SC...FLOOD WATCH THROUGH SATURDAY MORNING FOR SCZ048>051. MARINE...NONE. && $$ REV/ST ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1223 PM CDT FRI AUG 3 2007 .UPDATE... .AVIATION...18Z TAFS [RSL/SLN/HUT/ICT/CNU] ISOLATED THUNDERSTORMS WILL CONTINUE DEVELOPING THIS AFTERNOON ACROSS CENTRAL/SOUTHEASTERN KS AS ATMOSPHERE WILL BE VERY MOIST AND UNCAPPED. ACTIVITY WILL LIKELY BE DIURNAL...DISSIPATING TOWARD SUNSET. WILL CARRY VCTS AT THE TAF SITES TIL 02Z. HAZE MAY POSE SOME VISIBILITY PROBLEMS THIS AFTERNOON AT CNU FOR VFR/MVFR PILOTS. JMC && .PREV DISCUSSION... /ISSUED 1107 AM CDT FRI AUG 3 2007/ UPDATE... WILL MAINTAIN A SLIGHT CHANCE FOR ISOLATED CONVECTION IN FORECAST THIS AFTERNOON/EARLY EVE. LATEST RUC/SURFACE DATA INDICATING ATMOSPHERE BECOMING WEAKLY CAPPED ALREADY WITH CAPES OF NEAR 2,000 J/KG. RESIDUAL WEAK BOUNDARY WAS DRAPED ACROSS SOUTH CENTRAL/SOUTHEAST KS WHICH COULD PROVIDE A FOCUS. PRECIPITABLE WATER 1.5 TO 2 INCHES AREAWIDE AND WITH SLOW...ERRATIC STORM MOVEMENT EXPECTED...ISOLATED HEAVY RAINFALL POSSIBLE ONCE AGAIN. BASED ON PROJECTED DEWPOINTS/LATE AFTERNOON HIGHS...SOME LOCALES NEAR THE OKLAHOMA BORDER COULD SEE HEAT INDICES NEAR 100 THIS PM. JMC PREV DISCUSSION... /ISSUED 627 AM CDT FRI AUG 3 2007/ AVIATION...FOR THE 12Z TAF ISSUANCE PATCHY GROUND FOG (3-5SM) WAS IN PLACE ACROSS SEVERAL OF THE TAF SITES THIS MORNING. THIS FOG SHOULD GIVE WAY FAIRLY QUICKLY AFTER SUNRISE WITH MORE SCATTERED CUMULUS DEVELOPING AFTER 16Z AS THE CONVECTIVE TEMPERATURE IS MET. COULD SEE MORE ISOLATED STORMS DEVELOP THIS AFTERNOON FROM THE OUTFLOWS WHERE THE CURRENT SHOWERS ARE DEVELOPING. OTHERWISE...VFR CONDITIONS WILL BE THE RULE WITH MORE PATCHY FOG POSSIBLE TONIGHT. COX PREV DISCUSSION... /ISSUED 553 AM CDT FRI AUG 3 2007/ UPDATE... QUICK UPDATE TO EXPAND CHANCES FOR THUNDERSTORMS A LITTLE FURTHER SOUTH GIVEN CURRENT RADAR AND SATELLITE TRENDS. ISOLATED SHOWERS HAVE DEVELOPED FROM THE ALTOCUMULUS THAT WAS MOVING INTO THE FORECAST AREA OVERNIGHT AND ARE LIKELY TO PERSIST INTO THE MORNING HOURS. SCHRECK PREV DISCUSSION... /ISSUED 305 AM CDT FRI AUG 3 2007/ DISCUSSION... FORECAST CONCERNS ARE MAINLY PRECIPITATION CHANCES THROUGH THE PERIOD. TODAY-SUNDAY: AREA RADARS HAVE REMAINED QUIET SO FAR OVERNIGHT...WITH JUST SOME ALTOCUMULUS ACROSS THE CENTRAL AND HIGH PLAINS. THE NEAREST PRECIPITATION IS OVER SOUTHEAST WYOMING...IN ASSOCIATION WITH A WEAK UPPER DISTURBANCE IN THAT REGION. ASIDE FROM PATCHY GROUND FOG AT MANY SITES ACROSS THE REGION...ALL REMAINS FAIRLY QUIET. THE PERSISTENT PATTERN THAT HAS BEEN THE STORY LATELY WILL CONTINUE FOR AT LEAST ANOTHER FEW DAYS IF NOT THROUGH THE NEXT WEEK. A BROAD UPPER RIDGE OVER MUCH OF THE US WILL REMAIN INTACT...WITH SOME WEAK DISTURBANCES THROUGH THE FLOW AT TIMES. MOISTURE TRANSPORT CONTINUES TO BRING MOISTURE RIGHT THROUGH EASTERN KANSAS...AND CAPE VALUES INCREASE WITH DAYTIME HEATING EACH DAY. SO IN GENERAL...IT SEEMS QUITE REASONABLE THAT THERE IS A CHANCE FOR INSTABILITY SHOWERS EACH AFTERNOON/EARLY EVENING. FORECAST SOUNDINGS DO BECOME A BIT DRIER THROUGH THE NEXT COUPLE DAYS...SO LIKELY THE COVERAGE OF THESE SHOWERS/THUNDERSTORMS WILL DECREASE EACH DAY. TEMPERATURES WILL CONTINUE TO BE NEAR NORMAL...GETTING A SMIDGE WARMER EACH DAY. MONDAY-THURSDAY: AGAIN...MODELS INDICATE THAT THE GENERAL PATTERN PERSISTS THROUGH THE WEEK. A MORE SIGNIFICANT UPPER LEVEL SHORTWAVE TROUGH IS PROGGED TO MOVE ACROSS NORTHERN KANSAS ON TUESDAY AND TUESDAY NIGHT...BRINGING PERHAPS GREATER CHANCES FOR THUNDERSTORMS ACROSS THE REGION. OTHERWISE...HIGH TEMPERATURES IN THE MIDDLE 90S CONTINUE...ALONG WITH MILD NIGHTS. SCHRECK AVIATION... 06Z TAFS...DIURNAL COOLING COUPLED WITH VERY MOIST LOW-LEVELS AND LIGHT WINDS SHOULD PROMOTE MVFR VISIBILITIES TOWARD MORNING ACROSS THE AREA. OTHERWISE...MORE ISOLATED TO WIDELY SCATTERED SHOWERS/THUNDERSTORMS ANTICIPATED FOR FRIDAY AFTERNOON/EVENING...ESPECIALLY ACROSS EAST-CENTRAL/NORTHEAST KANSAS WHERE CONVERGENCE SHOULD BE GREATEST ALONG WEAK BOUNDARY. KLEINSASSER && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 93 72 94 74 / 20 20 10 10 HUTCHINSON 92 71 95 73 / 20 20 10 10 NEWTON 93 72 94 73 / 20 20 10 10 ELDORADO 93 71 93 73 / 20 20 10 10 WINFIELD-KWLD 93 72 94 74 / 20 20 10 10 RUSSELL 91 72 96 73 / 20 20 10 10 GREAT BEND 91 72 96 73 / 20 20 10 10 SALINA 92 72 95 74 / 20 20 10 10 MCPHERSON 92 71 95 73 / 20 20 10 10 COFFEYVILLE 93 71 94 73 / 20 20 10 10 CHANUTE 91 71 93 73 / 20 20 10 10 IOLA 91 71 93 73 / 20 20 10 10 PARSONS-KPPF 93 71 94 72 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1107 AM CDT FRI AUG 3 2007 .UPDATE... WILL MAINTAIN A SLIGHT CHANCE FOR ISOLATED CONVECTION IN FORECAST THIS AFTERNOON/EARLY EVE. LATEST RUC/SURFACE DATA INDICATING ATMOSPHERE BECOMING WEAKLY CAPPED ALREADY WITH CAPES OF NEAR 2,000 J/KG. RESIDUAL WEAK BOUNDARY WAS DRAPED ACROSS SOUTH CENTRAL/SOUTHEAST KS WHICH COULD PROVIDE A FOCUS. PRECIPITABLE WATER 1.5 TO 2 INCHES AREAWIDE AND WITH SLOW...ERRATIC STORM MOVEMENT EXPECTED...ISOLATED HEAVY RAINFALL POSSIBLE ONCE AGAIN. BASED ON PROJECTED DEWPOINTS/LATE AFTERNOON HIGHS...SOME LOCALES NEAR THE OKLAHOMA BORDER COULD SEE HEAT INDICES NEAR 100 THIS PM. JMC && .PREV DISCUSSION... /ISSUED 627 AM CDT FRI AUG 3 2007/ AVIATION...FOR THE 12Z TAF ISSUANCE PATCHY GROUND FOG (3-5SM) WAS IN PLACE ACROSS SEVERAL OF THE TAF SITES THIS MORNING. THIS FOG SHOULD GIVE WAY FAIRLY QUICKLY AFTER SUNRISE WITH MORE SCATTERED CUMULUS DEVELOPING AFTER 16Z AS THE CONVECTIVE TEMPERATURE IS MET. COULD SEE MORE ISOLATED STORMS DEVELOP THIS AFTERNOON FROM THE OUTFLOWS WHERE THE CURRENT SHOWERS ARE DEVELOPING. OTHERWISE...VFR CONDITIONS WILL BE THE RULE WITH MORE PATCHY FOG POSSIBLE TONIGHT. COX PREV DISCUSSION... /ISSUED 553 AM CDT FRI AUG 3 2007/ UPDATE... QUICK UPDATE TO EXPAND CHANCES FOR THUNDERSTORMS A LITTLE FURTHER SOUTH GIVEN CURRENT RADAR AND SATELLITE TRENDS. ISOLATED SHOWERS HAVE DEVELOPED FROM THE ALTOCUMULUS THAT WAS MOVING INTO THE FORECAST AREA OVERNIGHT AND ARE LIKELY TO PERSIST INTO THE MORNING HOURS. SCHRECK PREV DISCUSSION... /ISSUED 305 AM CDT FRI AUG 3 2007/ DISCUSSION... FORECAST CONCERNS ARE MAINLY PRECIPITATION CHANCES THROUGH THE PERIOD. TODAY-SUNDAY: AREA RADARS HAVE REMAINED QUIET SO FAR OVERNIGHT...WITH JUST SOME ALTOCUMULUS ACROSS THE CENTRAL AND HIGH PLAINS. THE NEAREST PRECIPITATION IS OVER SOUTHEAST WYOMING...IN ASSOCIATION WITH A WEAK UPPER DISTURBANCE IN THAT REGION. ASIDE FROM PATCHY GROUND FOG AT MANY SITES ACROSS THE REGION...ALL REMAINS FAIRLY QUIET. THE PERSISTENT PATTERN THAT HAS BEEN THE STORY LATELY WILL CONTINUE FOR AT LEAST ANOTHER FEW DAYS IF NOT THROUGH THE NEXT WEEK. A BROAD UPPER RIDGE OVER MUCH OF THE US WILL REMAIN INTACT...WITH SOME WEAK DISTURBANCES THROUGH THE FLOW AT TIMES. MOISTURE TRANSPORT CONTINUES TO BRING MOISTURE RIGHT THROUGH EASTERN KANSAS...AND CAPE VALUES INCREASE WITH DAYTIME HEATING EACH DAY. SO IN GENERAL...IT SEEMS QUITE REASONABLE THAT THERE IS A CHANCE FOR INSTABILITY SHOWERS EACH AFTERNOON/EARLY EVENING. FORECAST SOUNDINGS DO BECOME A BIT DRIER THROUGH THE NEXT COUPLE DAYS...SO LIKELY THE COVERAGE OF THESE SHOWERS/THUNDERSTORMS WILL DECREASE EACH DAY. TEMPERATURES WILL CONTINUE TO BE NEAR NORMAL...GETTING A SMIDGE WARMER EACH DAY. MONDAY-THURSDAY: AGAIN...MODELS INDICATE THAT THE GENERAL PATTERN PERSISTS THROUGH THE WEEK. A MORE SIGNIFICANT UPPER LEVEL SHORTWAVE TROUGH IS PROGGED TO MOVE ACROSS NORTHERN KANSAS ON TUESDAY AND TUESDAY NIGHT...BRINGING PERHAPS GREATER CHANCES FOR THUNDERSTORMS ACROSS THE REGION. OTHERWISE...HIGH TEMPERATURES IN THE MIDDLE 90S CONTINUE...ALONG WITH MILD NIGHTS. SCHRECK AVIATION... 06Z TAFS...DIURNAL COOLING COUPLED WITH VERY MOIST LOW-LEVELS AND LIGHT WINDS SHOULD PROMOTE MVFR VISIBILITIES TOWARD MORNING ACROSS THE AREA. OTHERWISE...MORE ISOLATED TO WIDELY SCATTERED SHOWERS/THUNDERSTORMS ANTICIPATED FOR FRIDAY AFTERNOON/EVENING...ESPECIALLY ACROSS EAST-CENTRAL/NORTHEAST KANSAS WHERE CONVERGENCE SHOULD BE GREATEST ALONG WEAK BOUNDARY. KLEINSASSER && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 93 72 94 74 / 20 20 10 10 HUTCHINSON 92 71 95 73 / 20 20 10 10 NEWTON 93 72 94 73 / 20 20 10 10 ELDORADO 93 71 93 73 / 20 20 10 10 WINFIELD-KWLD 93 72 94 74 / 20 20 10 10 RUSSELL 91 72 96 73 / 20 20 10 10 GREAT BEND 91 72 96 73 / 20 20 10 10 SALINA 92 72 95 74 / 20 20 10 10 MCPHERSON 92 71 95 73 / 20 20 10 10 COFFEYVILLE 93 71 94 73 / 20 20 10 10 CHANUTE 91 71 93 73 / 20 20 10 10 IOLA 91 71 93 73 / 20 20 10 10 PARSONS-KPPF 93 71 94 72 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 344 AM CDT THU AUG 2 2007 .DISCUSSION... REGIONAL RADAR LOOP SHOWS OUTFLOW BOUNDARY PUSHING SOUTHEAST ACROSS THE CWA THIS MORNING. OTHER SMALL OUTFLOWS WERE NOTED ACROSS REPUBLIC COUNTY AS WELL. AN MCV WAS STILL SPINNING OVER FAR NORTHEAST KANSAS...SE NEBRASKA AND NW MISSOURI THIS MORNING. THIS HAS SUSTAINED CONVECTION IN THIS GENERAL AREA OVER THE PAST FEW HOURS. THETA RIDGE LAY ACROSS THE CWA THIS MORNING AND RUC KEEPS IT IN PLACE. CONVECTION THAT LED TO FLASH FLOODING IN REPUBLIC COUNTY IS DISSIPATING AT THIS TIME. ADDITIONAL CONVECTION WAS OCCURRING ACROSS SOUTH CENTRAL NEBRASKA. MCV MENTIONED ABOVE LOOKS TO REMAIN IN THE SAME AREA THROUGH THE MORNING HOURS. ADDITIONALLY SEVERAL BOUNDARIES WILL BE PRESENT ACROSS THE FORECAST AREA TODAY AND WILL BROAD BRUSH THE POPS ACROSS THE AREA. WILL MAINTAIN THE HIGHEST IN NORTH CENTRAL AND NORTHEAST KANSAS ESPECIALLY NEAR THE NEBRASKA BORDER TODAY. WILL KEEP THE FLASH FLOOD WATCH GOING THROUGH 18Z TODAY EVEN THROUGH CONVECTION IS DISSIPATING ACROSS NORTH CENTRAL KANSAS. GIVEN TREND OF THE PAST FEW DAYS WILL POSSIBLY SEE SOME ADDITIONAL DEVELOPMENT THIS MORNING OF CONVECTION AND WITH VERY HIGH PWS EXPECT TO SEE RAINFALL RATES OF 2 TO 3 INCHES PER HOUR ALONG WITH VERY SLOW MOVEMENT OF CELLS. CLOUDS WILL AGAIN PLAY A ROLE WITH HIGHS TODAY AND ADJUSTED PRIOR FORECAST SLIGHTLY WITH HIGHS IN THE UPPER 80S TO LOWER 90S. FOR TONIGHT WEAK ENERGY TO MOVE OUT OF MONTANA ACROSS NEBRASKA OVERNIGHT. BOUNDARIES LEFT FROM CONVECTION WILL ACT AS A FOCUS FOR ADDITIONAL DEVELOPMENT THIS EVENING. AGAIN LOCALLY HEAVY RAINS ARE POSSIBLE WITH 2 INCH PWS. ON FRIDAY...NORTHERN PLAINS SHORTWAVE WILL MOVE ACROSS NEBRASKA WITH GOOD WARM AND MOISTURE ADVECTION ACROSS KANSAS. SOME ISENTROPIC LIFT MAY BE ENOUGH TO GENERATE SOME CONVECTION ESPECIALLY ACROSS NORTH CENTRAL KANSAS AND MADE ONLY SLIGHT ADJUSTMENTS TO POPS. PRECIPITATION CHANCES SHIFT NORTHWARD BY SATURDAY MORNING WITH NORTHERN COUNTIES ON THE FRINGE OF POSSIBLE MCS ACROSS NEBRASKA AND IOWA. RIDGE BUILDS THEREAFTER FOR THE REST OF THE WEEKEND. NO CHANGES TO THE EXTENDED. 53 && .AVIATION... TROPICAL TYPE CONVECTION BEEN MAINLY CONFINED TO FAR NORTHERN SECTIONS OF THE CWA THROUGH EARLY MORNING THUS FAR. NO LARGE SCALE FORCING PRESENT WITH PREVIOUS CONVECTION COLD POOLS ENHANCING AND DEVELOPING NEW CONVECTION. SEVERAL DIFFUSE SURFACE BOUNDARIES ARE STRETCHED ACROSS THE AREA AND NEW ISOLATED CONVECTION CERTAINLY POSSIBLE THROUGHOUT REGION. THIN MID/UPPER CLOUD DECK ACROSS THE AREA FROM DISSIPATED CONVECTION OVERHEAD WITH VISIBILITIES RANGING FROM 4 TO 6 MILES. GRADUAL IMPROVEMENT IN VISIBILITY ANTICIPATED THROUGH THE MID TO LATE MORNING HOURS. REFER TO SHORT TERM FORECAST DISCUSSION FOR ADDITIONAL DETAILS. BLAIR && .TOP WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH NORTHERN BORDER COUNTIES AND CLOUD COUNTY UNTIL 18Z TODAY. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 125 AM EDT FRI AUG 3 2007 UPDATED FOR 06Z TAF ISSUANCE .UPDATE (ISSUED AT 743 PM EDT THU AUG 2)... ISSUED A RED FLAG WARNING EARLIER TO INCLUDE MUCH OF THE WEST HALF OF UPPER MICHIGAN AFTER COORDINATION WITH MICHIGAN DNR AND USFS. RHS MADE A VERY QUICK FALL LATE THIS AFTERNOON AS LOW PRECIPITABLE WATER AIRMASS ADVECTING IN BEHIND THE FRONTAL PASSAGE LAST NIGHT COMBINED WITH DEEP MIXING. 18Z TAMDAR SOUNDING FROM SAW LOOKED EXTREMELY DRY WHILE MIXED UP TO 800MB. COORDINATION WITH USERS ALSO REVEALED QUITE A FEW SMALL FIRES DEVELOPED THIS AFTERNOON... INCLUDING ONE THAT CAN BE SEEN ON VISIBLE SATELLITE AND 3.9 UM IMAGERY ABOUT 4 MILES SE OF PINE STUMP JUNCTION IN LUCE COUNTY. WITH THE SUN GOING DOWN...RELATIVE HUMIDITIES ARE STARTING TO CLIMB BACK UP AND WINDS ARE DIMINISHING...THUS THE EXPIRE TIME OF 8 PM EDT LOOKS GOOD. IN ADDITION...HAVE LOWERED DEWPOINTS TOMORROW GIVEN THE FACT THAT THE AIRMASS UPSTREAM IS AS JUST AS DRY AS THAT OVER US NOW. GOING HIGH TEMPERATURES FOR FRIDAY LOOKED OKAY...THUS THE AREA CURRENTLY EXPERIENCING LOW RELATIVE HUMIDITIES MAY SEE SIMILAR READINGS TOMORROW. HOWEVER...TEMPERATURES ARE NOT AS HIGH AS THEY ARE TODAY...THUS THE RH VALUE SHOULD BE A BIT HIGHER...AROUND THE RED FLAG CRITERIA OF 25 PERCENT. AS FOR RED FLAG POTENTIAL TOMORROW... THE BIG QUESTION IS WHETHER THE WINDS WILL REACH CRITERIA. RIGHT NOW THEY LOOK TO BE AROUND 10 KNOTS OVER THE AREA THAT SEES THE LOWEST RELATIVE HUMIDITIES...WHICH WOULD BE JUST UNDER CRITERIA. NAM SOUNDINGS WOULD NOT SUGGEST MUCH GUSTING...THOUGH THE 13 KM RUC SHOWS 20 KNOT GUSTS (SIMILAR TO TODAY) OVER THE LOW RELATIVE HUMIDITY AREA. AFTER COORDINATION WITH MICHIGAN DNR AND USFS...HAVE DECIDED TO GO WITH A FIRE WEATHER WATCH. IF WINDS LOOK LIKE THE 13 KM RUC AND THE RELATIVE HUMIDITIES ARE CERTAIN TO FALL TO THE 25 PERCENT LEVEL DURING THE MIDNIGHT SHIFT...THE WATCH CAN BE UPGRADED TO A RED FLAG WARNING. && .SHORT TERM (TONIGHT AND FRI)... THE UPPER AIR PATTERN CONSISTS OF A 500 MB RIDGE ACROSS THE WESTERN U.S. WITH A TROUGH ACROSS THE GREAT BASIN...A TROUGH ACROSS CENTRAL CANADA DOWN INTO THE UPPER GREAT LAKES AND RIDGING ACROSS THE ERN U.S. FAIRLY STRONG 500 MB CLOSED LOW ALONG THE HUDSON BAY SHORELINE OF MANITOBA/ONTARIO WITH STRONG CYCLONIC SPIN NOTED ON WATER VAPOR AND WRAPAROUND MOISTURE HEADING SOUTHEAST. TROUGH REMAINS IN PLACE WITH A SHORTWAVE MOVING THROUGH IT THIS AFTERNOON AND EARLY EVENING. PROBLEM IS VERY LITTLE MOISTURE IS AVAILABLE AS IT LOOKS LIKE WITH EXTRAPOLATION THAT THE WRAPAROUND MOISTURE WILL STAY TO THE NORTH. DRY AIR CONTINUES TO WORK ITS WAY INTO THE AREA AS DEW POINTS HAVE DROPPED INTO THE 40S AND 50S ACROSS THE WESTERN HALF OF THE CWA LATE THIS MORNING. DRY AIR HAS MADE IT FAR ENOUGH EAST THAT IS HAS SUPPRESSED CONVECTION ON THE LAKE MICHIGAN LAKE BREEZE FOR THE MOST PART AS CONVECTION TRIED TO GO TO THE EAST AND SOUTH OF THE AREA THIS AFTERNOON. OVERALL...QUIET WEATHER WILL CONTINUE. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST TEMPERATURE WISE AS WHAT WE HAD IN THERE LOOKED GOOD. WENT CLOSE TO ADJMAV FOR LOWS AND HIGHS WITH A FEW MINOR TWEAKS HERE AND THERE. PLENTY OF SUNSHINE SHOULD ALLOW MIXING 850 MB TEMPERATURES DOWN TO THE SFC FOR HIGHS WHICH GIVES ME CLOSE TO ADJMAV CONDITIONS. .LONG TERM (FRI NIGHT THROUGH NEXT WED)... THE LOW OVER SOUTHEAST HUDSON BAY WILL CONTINUE TO TREK EAST FRIDAY NIGHT AND SATURDAY AS THE RIDGE OVER SASKATCHEWAN SHIFT INTO MANITOBA. MEANWHILE...A SHORTWAVE WILL SLIDE THROUGH WISCONSIN ON SATURDAY. THE AIR MASS WILL REMAIN DRY OVER THE FORECAST AREA. A SHORTWAVE WILL MOVE INTO THE WESTERN U.P. ON SATURDAY NIGHT AND SUNDAY. GFS TRIES TO KEEP THIS SOUTH OF THE FORECAST AREA...WHEREAS NAM/ECMWF/GEM MOVE THE SHORTWAVE INTO THE U.P. WILL FAVOR THE MAJOR SOLUTION AND KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS. A SURFACE LOW WILL MOVE ACROSS JAMES BAY INTO WEST CENTRAL QUEBEC SUNDAY NIGHT DRAGGING A COLD FRONT OUT OF THE NORTHERN PLAINS INTO THE NORTHERN MISSISSIPPI RIVER VALLEY. VERY WEAK SHORTWAVES WILL ACCOMPANY THIS FRONTAL SYSTEM. ISENTROPIC ASCENT AHEAD OF THE FRONT ALONG WITH MID LEVEL INSTABILITY WILL PRODUCE SOME SHOWERS AND THUNDERSTORMS. LIMITING FACTOR WILL THE AMOUNT OF AVAILABLE MOISTURE. THIS WILL PERSIST THROUGH MONDAY. IN THE AFTERNOON TEMPERATURES WILL REACH TO AROUND 80 WHICH WILL SUPPORT SOME LAKE BREEZES CONVERGENCE WHICH COULD AIDE IN THE DEVELOPMENT OF MORE SHOWERS. THUS WILL KEEP A CHANCE GOING THROUGH THE PERIOD FOR NOW. A NEW ZONAL FLOW WILL SET UP ACROSS THE NORTHERN CONUS. A SHORTWAVE WILL MOVE THROUGH THE FORECAST AREA MONDAY NIGHT FOLLOWED BY ANOTHER ON TUESDAY. A SURFACE LOW MOVING UP THE FRONT WILL MOVE ACROSS NORTHERN LAKE MICHIGAN. MOIST AIR WILL SPREAD INTO THE AREA WRAPPING AROUND THE LOW. THE COLD FRONT WILL CONTINUE TO SHIFT SOUTHEAST INTO THE LOWER GREAT LAKES TUESDAY NIGHT AND WEDNESDAY. FOLLOWED BY A WEAK RIDGE WHICH WILL MOVE INTO THE U P ON WEDNESDAY. A WEAK SHORTWAVE WILL RACE ACROSS THE FORECAST AREA ON WEDNESDAY. LOW LEVEL MOISTURE WILL BE VERY LIMITED. LAKE BREEZES SHOULD SET UP AND COULD POSSIBLY TRIGGER A SHOWERS WITH THUNDER OR TWO...SO WILL KEEP A SLIGHT CHANCE GOING FOR NOW. MORE DRY AIR WILL MOVE INTO THE FORECAST AREA UNDER THE INFLUENCE OF A HIGH LATE WEDNESDAY...SO WILL DROP EVEN A MENTION OF EVEN A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. CONDITIONS WILL REMAIN DRY THROUGH THE REST OF THE WEEK NEXT WEEK. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... VFR CONDITIONS AND CLEAR SKIES ARE EXPECTED TO CONTINUE THROUGH THE NEXT 24 HOURS WITH DRY HIGH PRESSURE BUILDING IN. WINDS WILL PICK BACK UP AGAIN AT THE TAF SITES WITH DAYTIME HEATING ON FRI...BUT DEFINITELY NOT AS STRONG AS YESTERDAY. IN ADDITION...A LAKE BREEZE FROM LAKE SUPERIOR MAY ENTER SAW LATE FRIDAY AFTERNOON. EXPECT WINDS TO DIMINISH FRI EVENING AS THE HIGH PRESSURE AREA MOVES OVERHEAD. && .MARINE (FOR 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... 10 TO 20 KT WINDS WILL CONTINUE ACROSS THE LAKE TONIGHT AS A SECONDARY COLD FRONT TIGHTENS GRADIENT OVR ENTIRE LAKE THIS EVENING INTO MUCH OF FRIDAY. WINDS DIMINISH SUBSTANTIALLY BY FRI EVENING AS HIGH PRES RIDGE MOVES IN. DESPITE ANOTHER LOW PRES SYSTEM/WARM FRONT AFFECTING THE UPPER GREAT LAKES BY EARLY NEXT WEEK...EXPECT WINDS TO REMAIN BLO 20 KT AND NO GALES FORESEEN. $$ .MQT WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FOR THIS AFTERNOON AND EVENING MIZ001>005-009>013-084. && $$ UPDATE/AVIATION...AJ SHORT TERM/MARINE...GM LONG TERM...DLG mi AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE MARQUETTE MI 743 PM EDT THU AUG 2 2007 .UPDATE... ISSUED A RED FLAG WARNING EARLIER TO INCLUDE MUCH OF THE WEST HALF OF UPPER MICHIGAN AFTER COORDINATION WITH MICHIGAN DNR AND USFS. RHS MADE A VERY QUICK FALL LATE THIS AFTERNOON AS LOW PRECIPITABLE WATER AIRMASS ADVECTING IN BEHIND THE FRONTAL PASSAGE LAST NIGHT COMBINED WITH DEEP MIXING. 18Z TAMDAR SOUNDING FROM SAW LOOKED EXTREMELY DRY WHILE MIXED UP TO 800MB. COORDINATION WITH USERS ALSO REVEALED QUITE A FEW SMALL FIRES DEVELOPED THIS AFTERNOON... INCLUDING ONE THAT CAN BE SEEN ON VISIBLE SATELLITE AND 3.9 UM IMAGERY ABOUT 4 MILES SE OF PINE STUMP JUNCTION IN LUCE COUNTY. WITH THE SUN GOING DOWN...RELATIVE HUMIDITIES ARE STARTING TO CLIMB BACK UP AND WINDS ARE DIMINISHING...THUS THE EXPIRE TIME OF 8 PM EDT LOOKS GOOD. IN ADDITION...HAVE LOWERED DEWPOINTS TOMORROW GIVEN THE FACT THAT THE AIRMASS UPSTREAM IS AS JUST AS DRY AS THAT OVER US NOW. GOING HIGH TEMPERATURES FOR FRIDAY LOOKED OKAY...THUS THE AREA CURRENTLY EXPERIENCING LOW RELATIVE HUMIDITIES MAY SEE SIMILAR READINGS TOMORROW. HOWEVER...TEMPERATURES ARE NOT AS HIGH AS THEY ARE TODAY...THUS THE RH VALUE SHOULD BE A BIT HIGHER...AROUND THE RED FLAG CRITERIA OF 25 PERCENT. AS FOR RED FLAG POTENTIAL TOMORROW... THE BIG QUESTION IS WHETHER THE WINDS WILL REACH CRITERIA. RIGHT NOW THEY LOOK TO BE AROUND 10 KNOTS OVER THE AREA THAT SEES THE LOWEST RELATIVE HUMIDITIES...WHICH WOULD BE JUST UNDER CRITERIA. NAM SOUNDINGS WOULD NOT SUGGEST MUCH GUSTING...THOUGH THE 13 KM RUC SHOWS 20 KNOT GUSTS (SIMILAR TO TODAY) OVER THE LOW RELATIVE HUMIDITY AREA. AFTER COORDINATION WITH MICHIGAN DNR AND USFS...HAVE DECIDED TO GO WITH A FIRE WEATHER WATCH. IF WINDS LOOK LIKE THE 13 KM RUC AND THE RELATIVE HUMIDITIES ARE CERTAIN TO FALL TO THE 25 PERCENT LEVEL DURING THE MIDNIGHT SHIFT...THE WATCH CAN BE UPGRADED TO A RED FLAG WARNING. && .SHORT TERM (TONIGHT AND FRI)... THE UPPER AIR PATTERN CONSISTS OF A 500 MB RIDGE ACROSS THE WESTERN U.S. WITH A TROUGH ACROSS THE GREAT BASIN...A TROUGH ACROSS CENTRAL CANADA DOWN INTO THE UPPER GREAT LAKES AND RIDGING ACROSS THE ERN U.S. FAIRLY STRONG 500 MB CLOSED LOW ALONG THE HUDSON BAY SHORELINE OF MANITOBA/ONTARIO WITH STRONG CYCLONIC SPIN NOTED ON WATER VAPOR AND WRAPAROUND MOISTURE HEADING SOUTHEAST. TROUGH REMAINS IN PLACE WITH A SHORTWAVE MOVING THROUGH IT THIS AFTERNOON AND EARLY EVENING. PROBLEM IS VERY LITTLE MOISTURE IS AVAILABLE AS IT LOOKS LIKE WITH EXTRAPOLATION THAT THE WRAPAROUND MOISTURE WILL STAY TO THE NORTH. DRY AIR CONTINUES TO WORK ITS WAY INTO THE AREA AS DEW POINTS HAVE DROPPED INTO THE 40S AND 50S ACROSS THE WESTERN HALF OF THE CWA LATE THIS MORNING. DRY AIR HAS MADE IT FAR ENOUGH EAST THAT IS HAS SUPPRESSED CONVECTION ON THE LAKE MICHIGAN LAKE BREEZE FOR THE MOST PART AS CONVECTION TRIED TO GO TO THE EAST AND SOUTH OF THE AREA THIS AFTERNOON. OVERALL...QUIET WEATHER WILL CONTINUE. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST TEMPERATURE WISE AS WHAT WE HAD IN THERE LOOKED GOOD. WENT CLOSE TO ADJMAV FOR LOWS AND HIGHS WITH A FEW MINOR TWEAKS HERE AND THERE. PLENTY OF SUNSHINE SHOULD ALLOW MIXING 850 MB TEMPERATURES DOWN TO THE SFC FOR HIGHS WHICH GIVES ME CLOSE TO ADJMAV CONDITIONS. .LONG TERM (FRI NIGHT THROUGH NEXT WED)... THE LOW OVER SOUTHEAST HUDSON BAY WILL CONTINUE TO TREK EAST FRIDAY NIGHT AND SATURDAY AS THE RIDGE OVER SASKATCHEWAN SHIFT INTO MANITOBA. MEANWHILE...A SHORTWAVE WILL SLIDE THROUGH WISCONSIN ON SATURDAY. THE AIR MASS WILL REMAIN DRY OVER THE FORECAST AREA. A SHORTWAVE WILL MOVE INTO THE WESTERN U.P. ON SATURDAY NIGHT AND SUNDAY. GFS TRIES TO KEEP THIS SOUTH OF THE FORECAST AREA...WHEREAS NAM/ECMWF/GEM MOVE THE SHORTWAVE INTO THE U.P. WILL FAVOR THE MAJOR SOLUTION AND KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS. A SURFACE LOW WILL MOVE ACROSS JAMES BAY INTO WEST CENTRAL QUEBEC SUNDAY NIGHT DRAGGING A COLD FRONT OUT OF THE NORTHERN PLAINS INTO THE NORTHERN MISSISSIPPI RIVER VALLEY. VERY WEAK SHORTWAVES WILL ACCOMPANY THIS FRONTAL SYSTEM. ISENTROPIC ASCENT AHEAD OF THE FRONT ALONG WITH MID LEVEL INSTABILITY WILL PRODUCE SOME SHOWERS AND THUNDERSTORMS. LIMITING FACTOR WILL THE AMOUNT OF AVAILABLE MOISTURE. THIS WILL PERSIST THROUGH MONDAY. IN THE AFTERNOON TEMPERATURES WILL REACH TO AROUND 80 WHICH WILL SUPPORT SOME LAKE BREEZES CONVERGENCE WHICH COULD AIDE IN THE DEVELOPMENT OF MORE SHOWERS. THUS WILL KEEP A CHANCE GOING THROUGH THE PERIOD FOR NOW. A NEW ZONAL FLOW WILL SET UP ACROSS THE NORTHERN CONUS. A SHORTWAVE WILL MOVE THROUGH THE FORECAST AREA MONDAY NIGHT FOLLOWED BY ANOTHER ON TUESDAY. A SURFACE LOW MOVING UP THE FRONT WILL MOVE ACROSS NORTHERN LAKE MICHIGAN. MOIST AIR WILL SPREAD INTO THE AREA WRAPPING AROUND THE LOW. THE COLD FRONT WILL CONTINUE TO SHIFT SOUTHEAST INTO THE LOWER GREAT LAKES TUESDAY NIGHT AND WEDNESDAY. FOLLOWED BY A WEAK RIDGE WHICH WILL MOVE INTO THE U P ON WEDNESDAY. A WEAK SHORTWAVE WILL RACE ACROSS THE FORECAST AREA ON WEDNESDAY. LOW LEVEL MOISTURE WILL BE VERY LIMITED. LAKE BREEZES SHOULD SET UP AND COULD POSSIBLY TRIGGER A SHOWERS WITH THUNDER OR TWO...SO WILL KEEP A SLIGHT CHANCE GOING FOR NOW. MORE DRY AIR WILL MOVE INTO THE FORECAST AREA UNDER THE INFLUENCE OF A HIGH LATE WEDNESDAY...SO WILL DROP EVEN A MENTION OF EVEN A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. CONDITIONS WILL REMAIN DRY THROUGH THE REST OF THE WEEK NEXT WEEK. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... VFR CONDITIONS AND CLEAR SKIES ARE EXPECTED THROUGHOUT THE NEXT 24 HOURS. GUSTY WEST WINDS WILL END THIS EVENING AT KCMX AND KSAW DUE TO THE LOSS OF DAYTIME HEATING. WINDS WILL PICK UP A BIT AGAIN ON FRIDAY WITH DAYTIME HEATING...BUT ARE NOT EXPECTED TO BE AS GUSTY AS THEY WERE TODAY...ESPECIALLY AT CMX. A LAKE BREEZE MAY ENTER KSAW BY LATE FRIDAY AFTERNOON...WITH WINDS FROM THE NORTHEAST. && .MARINE (FOR 4 PM LAKE SUPERIOR FORECAST ISSUANCE)...10 TO 20 KT WINDS WILL CONTINUE ACROSS THE LAKE TONIGHT AS A SECONDARY COLD FRONT TIGHTENS GRADIENT OVR ENTIRE LAKE THIS EVENING INTO MUCH OF FRIDAY. WINDS DIMINISH SUBSTANTIALLY BY FRI EVENING AS HIGH PRES RIDGE MOVES IN. DESPITE ANOTHER LOW PRES SYSTEM/WARM FRONT AFFECTING THE UPPER GREAT LAKES BY EARLY NEXT WEEK...EXPECT WINDS TO REMAIN BLO 20 KT AND NO GALES FORESEEN. $$ .MQT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM EDT (7 PM CDT) THIS EVENING MIZ002-004-005-009>013-084. FIRE WEATHER WATCH FOR FRIDAY AFTERNOON AND EVENING MIZ001>005-009>013-084. && $$ UPDATE...AJ SHORT TERM/MARINE...GM LONG TERM...DLG AVIATION...MRC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 143 AM EDT THU AUG 2 2007 .AVIATION...FINALLY SOME ACTUAL WX TO WORRY ABOUT. BUT...FOR THE MOST PART...VFR CONDITIONS ARE EXPECTED THROUGH THE NEXT 24 HOURS. WINDS ARE NOT EXPECTED TO REMAIN COMPLETELY CALM OVERNIGHT...AS A LIGHT WEST WIND HOLDS. HOWEVER...STRONGER WINDS JUST OFF THE SFC MAY LEAD TO A PERIOD OF LOW LEVEL WIND SHEAR PARTICULARLY AT PLN AND TVC. MID AND HIGH CLOUDS WILL INCREASE AROUND SUNRISE WELL IN ADVANCE OF A COLD FRONT THAT IS NOW MOVING THROUGH CENTRAL WI. THIS FRONT WILL MOVE ACROSS NRN LOWER MICHIGAN LATE MORNING THROUGH THE AFTERNOON ON THURSDAY...WITH AN ATTENDANT CHANCE OF SHOWERS/STORMS WITH IT. THIS CHANCE THOUGH IS NOT ESPECIALLY HIGH. WILL HAVE A PROB30 FOR THUNDER ONLY AT APN...AWAY FROM THE LAKE MI SHADOW...AND WHERE SOME INSTABILITY CAN BUILD BEFORE THE FRONT ARRIVES EARLY/MID AFTERNOON. ONLY A VCSH AT PLN/TVC. BEST CHANCE OF RAIN WILL BE SOUTH OF APN. ADAM && .UPDATE...ISSUED AT 936 PM WED AUG 1. SKIES ARE CLEAR ACROSS THE FORECAST AREA...BUT WON/T STAY THAT WAY. COLD FRONT PUSHING INTO FAR NW WI. VIGOROUS CONVECTION IS OCCURRING ALONG THE COAST OF NW UPPER MI...ESPECIALLY ONTONAGON AND VICINITY. WOW...ACTUAL WEATHER FOR ONCE. PRECIP CHANCES LATE TONIGHT ARE THE MAIN CONCERN. 18Z NAM PRETTY MUCH NAILED THE TIMING OF THE FRONT AND DEEP CONVECTION TO THE WEST...AND WILL FOLLOW THE FLAVOR OF IT/S PROG. (BY COMPARISON...THE RUC IS MUCH TOO SLOW...WITH PRECIP STILL OFFSHORE UPPER MI THRU 02Z.) BETWEEN THE NAM AND RADAR TRENDS...WILL SPEED UP PRECIP ONSET A BIT. LEADING CONVECTIVE ELEMENTS COULD REACH WHITEFISH PT JUST AFTER 06Z/2AM...1-2 HOURS AHEAD OF THE FRONT...AND SLOWLY PUSHING INTO EASTERN UPPER MI. DON/T SEE ANY MAJOR PUSH INTO NORTHERN LOWER MI BY 12Z/8AM...BUT NORTHERN EMMET COUNTY (AND BEAVER ISLAND) COULD SEE A SHOWER/STORM VERY LATE. CONVECTION SHOULD DECREASE IN COVERAGE AND INTENSITY AS IT HEADS EAST. OBVIOUSLY...DIURNAL HEATING WILL CONTINUE TO BE LOST. WE DO HAVE A RESPECTABLE LOW LEVEL JET...WITH 850MB WINDS NEARING 30KT. THOSE SW WINDS ARE CONTRIBUTING TO STORM DEVELOPMENT IN WESTERN UPPER MI. HOWEVER...THESE WINDS VEER WSW TONIGHT...LARGELY PARALLEL TO THE FRONT...AND THUS ARE POORLY ALIGNED TO PROVIDE SUBSTANTIAL ELEVATED INFLOW. WILL HAVE TO WATCH IF CONVECTIVE ELEMENTS CAN MAKE A RIGHT HAND TURN...BUT MEAN FLOW WILL REMAIN WESTERLY...AND ORGANIZED CONVECTION UPSTREAM IS SHOWING NO SIGNS OF DEVIANT MOTION. NO MAJOR CHANGES TO MIN TEMPS. ZOLTOWSKI && .PREV DISCUSSION...ISSUED 358 PM WED AUG 1... SFC/RUC/SATELLITE/RADAR AND UPPER AIR ANALYSIS SHOWING VERY FLAT CUMULUS OUTSIDE DEVELOPING AGAINST THE HIGHER TERRAIN IN INTERIOR NRN LOWER...UNDER STRONG SUBSIDENCE/CAPPED OFF HOT ATMOSPHERE. SFC TEMPS WERE RUNNING JUST SLIGHTLY LOWER THAN EXPECTED WITH NUMEROUS LOWER AND MIDDLE 90S. SFC TD`S HAVE BEEN ABLE TO MIX OUT TO THE UPPER 50S IN SOME LOCALES...BUT MOST AREAS WERE IN THE LOWER 60S...WHILE THE JUICIEST PLACES WERE ALONG THE LAKESHORES WHERE DEW POINTS WERE IN THE LOWER 70S (WATER TEMPS IN THE LOW TO MID 70S). HEAT INDICES UNDER THESE TEMPS/DEW POINTS WERE RUNNING ANYWHERE FROM 90F TO THE UPPER 90S. UPSTREAM COOL FRONT IS NOW PROGRESSING THROUGH SW ONTARIO AND INTERNATIONAL FALLS TO NORTH CENTRAL NEBRASKA. EARLIER CONVECTION ALONG THE FRONT WAS DIMINISHING (FROM THIS MORNING)...WHILE NEW CONVECTION IS NOW STARTING TO POP ALONG THE FRONTAL ZONE. TONIGHT...WITH ATMOSPHERE CAPPED OFF AROUND 750MB (CINH STILL >50J/KG...AND CONVECTIVE TEMPS OF >100F NEEDED WITH A DEW POINT OF 73F) EXPECT NO PRECIP THROUGH THE EVENING...WHILE THE FEW CUMULUS WE HAVE...ERODES TO CLEAR SKIES. COOL FRONT WILL MAKE SLOW BUT STEADY PROGRESS EASTWARD WHILE CONVECTION CONTINUES TO FIRE ACROSS MN. THIS ACTIVITY WILL SUSTAIN ITSELF TO SOME DEGREE WITH WEAK/MODERATE H8-H5 -DIVQ FROM UPPER SHORTWAVE TROUGH SWINGING THROUGH WESTERN ONTARIO. THE FRONT WILL MAKE IT INTO FAR WESTERN CHIP/MACK COUNTIES BY 12Z. ATTM...FORCING WITH ASSOCIATED SHORTWAVE TROUGH BEGINS TO LIFT NORTHEASTWARD AND EASTERN UPPER WILL BE ON THE TAIL END OF THE WEAKISH H8 LLJ (NOSE POINTING WELL EAST OF NRN MICHIGAN). WOULD EXPECT SOME ISOLATED SHOWERS AND MAYBE A FEW STORMS TRICKLING INTO CHIP/MACK OVERNIGHT. THIS SCENARIO DOES NOT LOOK TO HAVE CHANGED...ESPECIALLY CONSIDERING THE MONSOONAL MOISTURE SOURCE THAT GETS STRETCHED FARTHER AND FARTHER AWAY TO THE EAST...THINNING OUT TO JUST A NARROW CORRIDOR OF H8-H7 THETA-E THAT LAYS OUT ALONG THE FRONT. MOISTURE NOT EXPECTED TO BE AS GREAT AS PREVIOUSLY THOUGHT IN THE LOW LEVELS/SFC. WITH DEW POINTS MIXING OUT THE WAY THEY DID TO THE UPPER 50S AND LOWER 60S AGAIN TODAY....HAVE LOWERED MINS JUST A TOUCH INLAND AND FURTHER SOUTHEAST...MORE AHEAD OF THE FRONT. RAISED LOWS ALONG THE LAKESHORES...ESPECIALLY LAKE MICHIGAN WHERE WEAK SW FLOW AND WATER TEMPS IN THE LOWER 70S WILL KEEP A RATHER WARM NIGHT FOR THOSE REGIMES. THURSDAY...NARROW RIBBON OF H8-H7 THETA-E ALONG THE FRONT DRAGS SLOWLY ACROSS NRN LOWER IN THE LATE MORNING AND AFTERNOON. WITH THE ASSISTANCE OF DAYTIME HEATING...THIS WILL BE THE LIKELY BETTER CHANCE FOR STORMS...EVEN THOUGH THE UPPER SUPPORT FROM THE SHORTWAVE TROUGH PULLS EVEN FURTHER TO THE NORTHEAST. H8-H5 -DIV Q CONTINUES TO WEAKEN THROUGH THE AFTERNOON. WINDS DO NOT LOOK WEAK ENOUGH FOR LAKE BREEZES TO HELP INITIATE AFTERNOON ACTIVITY...BUT THE FRONT WILL AT LEAST HAVE SOME ISOLATED TO SCATTERED SHOWERS AND STORMS. IT JUST DOES NOT LOOK LIKE A SITUATION WHERE MANY AREAS CAN SEE RELIEF FROM THE RECENT DRY WEATHER. AS FAR AS INSTABILITY GOES...STRONG HEATING PRIOR TO THE ARRIVAL OF THE FRONT (PARTICULARLY SE CWA BY THE SAG BAY) WILL ALLOW TEMPS TO SOAR AGAIN INTO THE LOWER 90S. WITH HIGHER SFC TD`S POOLING ALONG THE FRONT IN TO THE MIDDLE AND POSSIBLY UPPER 60S (LOW 70S DO NOT LOOK POSSIBLE WITH OFFSHORE FLOW)...MLCAPES BY LATE AFTERNOON COULD BE AS HIGH AS 1500 J/KG. IT DOES LOOK LIKE IT WILL TAKE UNTIL VERY LATE IN THE AFTERNOON BEFORE ANYTHING CAN FIRE THOUGH WITHOUT ANY DECENT UPPER SUPPORT. THROW IN THE FACT THAT THIS FRONT WILL BE ARRIVING RIGHT AROUND MAX HEATING...AND WE COULD SEE A SITUATION WHERE STORMS WILL NOT BE ABLE TO FIRE EXCEPT FOR AREAS SOUTH OF M-72. WILL KEEP RIDING A SMALLISH CHANCE POP OF 25%...AND KEEP 30-35% CHANCES ACROSS THE SOUTHERN-MOST AREAS WHERE THE CAP CAN BE ERODED MORE EASILY. FREEZING LEVELS ARE IN THE 14KFT RANGE...BUT WET BULBS ARE AROUND 10.5KFT SO MAYBE SOME LOW END THREAT FOR THREE-QUARTER INCH HAIL IN ONE OF THE STRONGEST OF CELLS. MID LEVEL WIND FIELDS AROUND 35-40KTS MAY POSE A LOW END THREAT FOR A DAMAGING WIND EVENT TOO...BUT THE STRONGER WIND FIELDS ARE EXPECTED TO BE A BIT BEHIND THE FRONT. OVERALL...MINIMAL CHANCES FOR SEVERE WEATHER CONSIDERING THE EXPECTED COVERAGE OF STORMS AND KINEMATIC/THERMODYNAMIC ENVIRONMENT. DO NOT FEEL THAT THE HEAT ADVISORY IS WARRANTED...IN LIGHT OF LOWER SFC TD`S EXPECTED (NOT WIDESPREAD UPPER 60S/LOW 70S...IF FRONT SLOWS DOWN A BIT...MAYBE THERE IS A CHANCE...BUT UPPER 90S HEAT INDICES LOOK OK FOR THE FAR SE CWA. THEREFORE...NO HEAT ADVISORY SEEN AT THIS TIME. BAND OF DEEPER MOISTURE COMING THROUGH DOES NOT APPEAR TO HOLD ENOUGH MOISTURE AT THE SFC TO RESULT IN MARINE FOG (WITH WATER TEMPS IN THE LOWER 70S). SMD LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...AFTER SEVERAL DAYS OF EXCEEDINGLY WARM CONDITIONS (EVEN FOR LATE JULY/EARL AUGUST STANDARDS)...LOOKS LIKE A RETURN CLOSER TO NORMAL FOR MUCH OF THE EXTENDED AS UPPER MIDWEST DOMINATE MID AND UPPER LEVEL RIDGING GETS SHUNTED SOUTH IN RESPONSE TO SHORTWAVES TRAVERSING CENTRAL AND SOUTHERN CANADA. THIS SETS UP A MORE ZONAL APPEARANCE TO THE MID LEVEL FLOW...WITH NORTHERN MICHIGAN LYING JUST SOUTH OF STRONGEST WESTERLIES. BESIDES SOMEWHAT COOLER TEMPERATURES...HARD TO TIME SHORTWAVES TRAVERSING THE MID LEVELS COINCIDENT WITH POTENTIAL FOR SOME SEMBLANCE OF LOW LEVEL WAVY FRONTAL BOUNDARY WORKING ACROSS THE AREA...SHOULD SET THE STAGE FOR AT LEAST SOME MUCH NEEDED RAINFALL (LATEST U.S. DROUGHT MONITOR HAS MUCH OF NORTHERN MICHIGAN IN DROUGHT CONDITIONS...WITH NORTHWEST LOWER AND EASTERN UPPER MICHIGAN EXPERIENCING MODERATE DROUGHT. WOULD EXPECT FURTHER EXPANSION AND STRENGTHENING OF DROUGHT WHEN UPDATED READINGS COME OUT TOMORROW). FORECAST CONCERNS THROUGH THE EXTENDED CENTER ON AFOREMENTIONED SHOWER AND THUNDERSTORM THREAT WITH PASSAGE OF INDIVIDUAL SHORTWAVES. THURSDAY NIGHT THROUGH SATURDAY NIGHT...SOUTHERN EXTENSION OF SHORTWAVE PRIMARILY RESPONSIBLE FOR UPCOMING PATTERN CHANGE CROSSES NORTHERN MICHIGAN THURSDAY AFTERNOON AND EVENING. ASSOCIATED COOL FRONT EXPECTED TO CLEAR THE FORECAST AREA TO THE SOUTHEAST BY EVENING...PUTTING AN END TO ANY SHOWER THREAT EARLY THURSDAY NIGHT. AFTER SOME CONCERN EARLIER THIS WEEK THAT FRONT MAY HANG UP ACROSS CENTRAL OR SOUTHERN MICHIGAN...IT APPEARS LOW AND MID LEVEL FLOW WILL BE STRONG ENOUGH TO PUSH FRONTAL ZONE INTO THE UPPER OHIO VALLEY ON FRIDAY...ALLOWING HIGH PRESSURE TO BUILD INTO THE NORTHERN LAKES FRIDAY AND FRIDAY NIGHT. BY SATURDAY NIGHT...APPROACHING LOW AMPLITUDE SHORTWAVE BEGINS TO BUCKLE FRONT BACK NORTH AS HIGH PRESSURE SLIDES INTO THE NORTHEAST CONUS. HOWEVER...WITH LINGERING DRY MOISTURE PROFILES AND BETTER DYNAMICS WEST OF THE AREA...FEEL ASSOCIATED SHOWER THREAT WILL HOLD OFF UNTIL SUNDAY. THUS...WILL RUN WITH DRY CONDITIONS THROUGH THIS PERIOD (REMOVING CURRENT SATURDAY NIGHT POPS) UNDER GENERALLY CLEAR TO PARTLY CLOUDY SKIES. ALTHOUGH BY NO MEANS COOL...TEMPERATURES DO FALL OFF SOME BEHIND FRONTAL PASSAGE...WITH LOWS THURSDAY AND FRIDAY NIGHT FALLING INTO THE MID AND UPPER 50S...WITH HIGHS FRIDAY AND SATURDAY APPROACHING 80 TO THE MID 80S. LOWS SATURDAY NIGHT WILL BE A COUPLE DEGREES MILDER...THE LOW TO MID 60S...WITH WEAK WAA OVERSPREADING THE LAKES AND SOME INCREASE IN CLOUD COVER. SUNDAY THROUGH MONDAY...SOMEWHAT MORE ACTIVE WEATHER REGIME IN STORE FOR THE AREA AS HARD TO TIME SHORTWAVES TRAVERSING THE ZONAL FLOW WORK IN TANDEM WITH INCREASING WESTERN GULF OF MEXICO MOISTURE ADVECTION. AT THE SURFACE...AT LEAST AT THIS JUNCTURE...IT APPEARS OLD FRONT TO OUR SOUTH BOWS BACK NORTH AS A WARM FRONT...CROSSING NORTHERN MICHIGAN SUNDAY AFTERNOON AND EVENING...AND POSSIBLY RETURNING AS A COLD FRONT EARLY NEXT WEEK. GIVEN INHERENT TIMING ISSUES AT THIS POINT...AND FACT THAT OVERALL INTENSITY AND DYNAMICS OF SHORTWAVES REMAIN IN QUESTION...WILL CONTINUE CHANCE POP THEME. DESPITE ONGOING DROUGHT CONDITIONS AND NOT WANTING TO SOUND TOO OPTIMISTIC WITH PRECIPITATION CHANCES...HARD TO IGNORE DEEP MOISTURE PROFILES (PWATS APPROACHING OR EXCEEDING 2.00 INCHES) AND PRESENCE OF STRONG MID LEVEL FLOW JUST TO OUR NORTH EARLY NEXT WEEK...SO WENT AHEAD AND EXTENDED SHOWER AND THUNDERSTORM THREAT INTO MONDAY. MONDAY NIGHT THROUGH WEDNESDAY...MANY QUESTIONS WITH REGARD TO EVENTUALLY FRONTAL POSITION THROUGH THIS PERIOD. LATEST GFS SPINS UP A CONVECTIVELY INDUCED SURFACE LOW MONDAY NIGHT ACROSS UPPER MICHIGAN...WITH SUBSEQUENT NORTHWEST FLOW BEHIND SYSTEM HELPING PROPEL A COLD FRONT INTO THE NORTHERN OHIO VALLEY TUESDAY NIGHT. ON THE OTHER HAND...AND WHAT SEEMS MORE PLAUSIBLE GIVEN PROJECTED ZONAL FLOW...THE 00Z ECMWF HANGS THE FRONTAL BOUNDARY OVER THE NORTHERN LAKES. GIVEN THESE UNCERTAINTIES...TRIED TO FOLLOW HPC GUIDANCE...USING SLIGHT CHANCE POPS IN GRIDS (WILL NOT EXPLICITLY SHOW UP IN ZONES AT THIS TIME) TUESDAY THROUGH WEDNESDAY. AS FOR TEMPERATURES...EXPECT SEASONALLY MILD TO WARM CONDITIONS TO PREVAIL...WITH HIGH TEMPERATURES NEXT WEEK GENERALLY RANGING FROM THE UPPER 70S OVER EASTERN UPPER MICHIGAN TO THE LOW TO MID 80S OVER NORTHERN LOWER MICHIGAN. LOW TEMPERATURES THROUGH THE PERIOD WILL RANGE FROM THE UPPER 50S TO MIDDLE 60S. MSB && .APX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 142 AM CDT THU AUG 2 2007 .AVIATION...06Z TAF. START OUT THE TAF WITH PREVAILING VFR CONDITIONS. MAY BE SOME MID-LEVEL CLOUDINESS AT TIMES...BUT MAIN FOCUS WILL BE ON THE DEVELOPING LOW-LEVEL CLOUDINESS. START OUT WITH PREVAILING SCATTERED LOW-LEVEL CLOUDINESS WITH A TEMPO OF MVFR CONDITIONS WITH SHOWERS IN THE AREA. THEN AT 10Z WENT WITH IFR AS THE CEILING IS EXPECTED TO DROP TO 800 FEET. RETURN TO VFR AT 15Z WITH A PROB GROUP FOR MVFR AND SHOWERS TOWARD LATE MORNING AND AFTERNOON AS VERY MOIST AIR HANGS AROUND. && .PREV DISCUSSION... /ISSUED 1004 PM CDT WED AUG 1 2007/ DISCUSSION...UPDATED THE FORECAST TO REDUCE POPS ACROSS NORTHWESTERN CWA. THUNDERSTORMS HAVE DIED OFF ACROSS THIS AREA AND REDEVELOPMENT LATER TONIGHT SHOULD BE CONFINED TO THE SOUTHERN TWO THIRDS OF THE CWA BASED ON LATEST FORECAST MODEL RUNS. THEREFORE...ALSO CANCELED THE FLOOD WATCH ACROSS NORTHERN MOST COUNTIES. PREV DISCUSSION... /ISSUED 643 PM CDT WED AUG 1 2007/ AVIATION...00Z TAF. A COLD FRONT CONTINUES TO APPROACH THE KGRI TERMINAL FROM THE NORTHWEST EARLY THIS EVENING WITH SHOWERS AND THUNDERSTORMS ALONG AND BEHIND THE FRONT...AND ADDITIONAL SCATTERED THUNDERSTORMS AHEAD OF THE FRONT. VERY DIFFICULT TO TELL WHETHER SCATTERED THUNDERSTORMS AHEAD OF THE FRONT WILL TRACK RIGHT OVER THE TERMINAL...BUT THEY WILL BE SCATTERED ABOUT THE AREA. RAIN CHANCES CONTINUE OVERNIGHT AS THE FRONT MOVES IN...WITH WINDS BECOMING LIGHT AND VARIABLE IN THE VICINITY OF THE FRONT. BESIDES THE SHOWER/THUNDERSTORM ACTIVITY...THE OTHER CONCERN FOR THIS PERIOD IS THE DEVELOPMENT OF FOG AND LOW CEILINGS OVERNIGHT. WITH THE MOISTURE LADEN AIR MASS STILL IN PLACE AND WINDS BECOMING LIGHT NEAR THE FRONT...BELIEVE FOG AND ASSOCIATED REDUCED VISIBILITIES AND LOW CEILINGS WILL AGAIN DEVELOP DURING THE PRE-DAWN HOURS. PREV DISCUSSION... /ISSUED 309 PM CDT WED AUG 1 2007/ SHORT TERM...LATEST WATER VAPOR IMAGERY FROM THIS AFTERNOON CONTINUES TO SHOW AN UPPER RIDGE OVER THE ROCKIES WHILE A STRONG NORTHERN STREAM WAVE IS SEEN RIDING ACROSS THE UPPER MIDWEST. BETWEEN THESE SYSTEMS THE CENTRAL PLAINS REMAINS UNDER A VERY MOIST AND ACTIVE WEST TO NORTHWEST FLOW REGIME. CURRENT OBJECTIVE SURFACE ANALYSIS SHOWS A SLOWLY ADVANCING COLD FRONT STRETCHING FROM NORTHEAST COLORADO INTO NORTH CENTRAL NEBRASKA AND THE UPPER MIDWEST. DEEP BOUNDARY LAYER MOISTURE IS SEEN AHEAD OF THIS FRONT WITH DEWPOINTS IN THE UPPER 60S TO MID 70S. PAST MORNING UPPER AIR DATA ALONG WITH RUC INITIALIZATION DATA REVEALS PW VALUES AROUND 150 TO 200 PERCENT OF NORMAL. THE ATMOSPHERE UNDER THIS PATTERN IS GENERALLY UNCAPPED TO DEEP CONVECTION WITH SCATTERED CONVECTION SEEN NOT ONLY ALONG THE ADVANCING FRONT BUT WELL AHEAD IT AS WELL. A VERY WET PERIOD IS STARTING TO TAKE SHAPE FOR CENTRAL NEBRASKA INTO NORTH CENTRAL KANSAS AS THE COLD FRONT IS SHOWN TO SLIDE SOUTH INTO THE FORECAST AREA OVER THE NEXT 24 HOURS. WITH THE TAIL END OF THE NORTHERN STREAM WAVE AIDING THIS BOUNDARY TO THE SOUTH...DEEP CONVECTION OVER MOST OF THE AREA LOOKS VERY LIKELY TONIGHT INTO TOMORROW. AS MENTIONED ABOVE...PW VALUES REMAIN HIGH AND WITH SLOW STORM MOTION ALONG WITH BACK BUILDING OF CONVECTION LOOKING VERY POSSIBLE AT TIME...VERY HEAVY RAINFALL IS ALMOST A CERTAINTY. GIVEN PREEXISTING FLOODING CONDITIONS ACROSS LARGE PORTIONS OF THE AREA...A FLOOD WATCH HAS BEEN ISSUED THROUGH 18Z TOMORROW. MAIN QUESTION AS THE AREA HEADS INTO THURSDAY AFTERNOON TO THURSDAY NIGHT IS HOW FAR SOUTH THE BOUNDARY WILL PUSH. THE POTENTIAL DOES EXIST FOR FLOODING TO CONTINUE WELL INTO THE AFTERNOON TO EVENING HOURS DEPENDING ON HOW FAR SOUTH THIS FRONT SINKS. MOST OF THE MODELS ATTEMPT TO STALL THE BOUNDARY ACROSS CENTRAL KANSAS BY TOMORROW EVENING WITH THE CONVECTION EXPECTED TO SLOWLY DRIFT SOUTH ACROSS THE FORECAST AREA. THIS MAY MEAN THE FLOOD WATCH WILL NEED TO BE EXTENDED BEYOND 18Z AND MIDNIGHT SHIFT WILL HAVE TO LOOK THIS OVER CLOSELY. LONG TERM...12Z FRIDAY THROUGH WEDNESDAY. IDENTIFYING PERIODS FOR BETTER PRECIPITATION CHANCES IS THE MAIN DIFFICULTY. THERE APPEAR TO BE SEVERAL SHOTS FOR PRECIPITATION DURING THE EXTENDED PERIOD...BUT IDENTIFYING THE TIMING AND FAVORED LOCATIONS FOR THIS PRECIPITATION REMAINS DIFFICULT. MODEL-TO-MODEL AND RUN-TO-RUN CONSISTENCY CONTINUES TO STRUGGLE AS TO BE EXPECTED GIVEN THE SUBTLE SHORTWAVES AND BOUNDARIES RESPONSIBLE FOR THE PRECIP CHANCES. THUS GENERALLY KEPT PRECIP CHANCES CONFINED TO THOSE PERIODS FOR WHICH THE MODELS HAVE BEEN DISPLAYING BETTER RUN-TO-RUN CONSISTENCY AND ALSO RELIED HEAVILY ON ENSEMBLE DATA. WITH THIS BEING SAID...ONE OF THE BETTER CHANCES FOR RAIN LOOKS TO COME ON FRIDAY. A WARM FRONT LIFTS NORTHWARD ACROSS THE AREA WITH ATTENDANT INCREASED MOISTURE AND WARM AIR ADVECTION WHILE A MID-LEVEL SHORTWAVE SLIDES BY JUST TO THE NORTH. THUS HAVE INCREASED POPS ON FRIDAY AS THIS SHOULD GIVE US AN APPRECIABLE CHANCE FOR RAIN GIVEN THE PATTERN OF LATE...WITH PRECIP CHANCES PUSHING OFF TO THE NORTHEAST IN ASSOCIATION WITH THE WAVE AND LIFTING FRONT FRIDAY NIGHT. AFTER COOLER TEMPS ON FRIDAY WITH A GOOD AMOUNT OF CLOUDS AND POSSIBLE PRECIP...THE UPPER RIDGE BUILDS BACK IN OVER THE WEEKEND YIELDING WARMER TEMPS WITH HIGHS EXPECTED TO CLIMB BACK INTO THE 90S. BY SUNDAY EVENING...THE UPPER RIDGE BEGINS TO GET SHUNTED SOUTHEAST OPENING THE TRACK BACK UP FOR SHORTWAVES EMBEDDED IN THE WEST/SOUTHWEST FLOW ALOFT AND MCS ACTIVITY ON THE NORTHWEST SIDE OF THE RIDGE TO IMPACT THE FORECAST AREA. MODELS AND ENSEMBLE DATA HAVE BEEN FAIRLY CONSISTENT IN ADVERTISING SUCH EPISODES LATE SUNDAY INTO SUNDAY NIGHT AND TUESDAY NIGHT INTO WEDNESDAY...SO WILL CARRY POPS THESE PERIODS. LATEST RUN OF THE GFS SUGGESTS SOME POSSIBLE MCS ACTIVITY MONDAY NIGHT AS WELL...BUT HAVE DECIDED TO HOLD OFF ON PRECIP MENTION FOR THIS PERIOD UNTIL BETTER MODEL CONTINUITY AND ENSEMBLE SUPPORT SHOWS UP...BUT OVERALL PATTERN WOULD SUPPORT THIS POSSIBILITY. TEMPERATURES REMAIN WARMER EARLY TO MID NEXT WEEK UNDER SOUTHWEST FLOW ALOFT WITH HIGHS GENERALLY IN THE 90S AND LOWS AROUND 70. && .GID WATCHES/WARNINGS/ADVISORIES... NE...FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR NEZ041-048-049- 060>064-072>077-082>087. KS...FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR KSZ005>007-017>019. && $$ HEINLEIN ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 300 AM MDT FRI AUG 3 2007 .DISCUSSION... 400-250MB AIRCRAFT WIND PLOT EARLY THIS MORNING SHOWS THE UPPER LEVEL HIGH CENTER OVER KGUP...A 40-60 KNOT SOUTHWESTERLY JET OVER THE GREAT BASIN...AND A 20-30 KNOT NORTHEASTERLY JET OVER NE NM. WATER VAPOR LOOP SHOWS THE MAIN MOISTURE PLUME SHIFTING OVER WESTERN NM WHERE THE GOES SOUNDER HAS PICKED UP A FEW PWAT PIXELS AROUND 2.0 INCHES. LOWEST PWAT VALUES ARE OVER NE NM WHERE DRYING HAS BEEN DEVELOPING SINCE THURS EVE. 08Z SFC ANALYSIS SHOWS A BROAD AREA OF SFC LOW PRES OVER WESTERN NM BENEATH THIS MOISTURE PLUME WITH THE 08Z RUC ANALYSIS SHOWING THE BEST LOW LEVEL MOISTURE CONVERGENCE OVER THIS AREA. THINK THE BEST CHANCE FOR HEAVY RAINFALL TODAY WILL BE ALONG AND WEST OF THE CONTINENTAL DIVIDE PER LATEST OBSERVED SATELLITE TRENDS...RUC ANALYSIS...AND THE GENERAL AGREEMENT AMONGST THE 00Z GFS/NOGAPS/NGM. RAISED POPS IN THIS AREA AND CONTINUED MENTION OF HEAVY RAINFALL. A FEW SHOWERS AND STORMS WILL ALSO DEVELOP OVER THE CENTRAL MTNS THIS AFTERNOON HOWEVER COVERAGE SHOULD BE LIMITED COMPARED TO THURS SINCE THE BEST UPPER LEVEL DYNAMICS ARE SHIFTING INTO THE WESTERN HALF OF THE STATE. STILL HAVE TO CONTEND WITH HIGH CHANCE POPS OVER THE SE AND SACRAMENTO MTNS AS A WEAK UPPER DISTURBANCE OVER W TX SHIFTS SLOWLY WESTWARD TOWARD KELP. 06Z MREF/03Z SREF SOLUTIONS IN GOOD AGREEMENT THAT A 576DM H5 TROUGH BUILDING OVER THE NW CONUS OVER THE WEEKEND WILL PUSH THE MOISTURE PLUME EASTWARD INTO THE CENTRAL PORTIONS OF THE STATE AS SW FLOW DEVELOPS OVER THE GREAT BASIN. RAISED POPS OVER THE CENTRAL MTNS AND VALLEYS SAT AND SUN. MODELS THEN DISAGREE ON HOW FAR EAST THE MAIN MOISTURE PLUME SETS UP INTO EARLY NEXT WEEK. LEFT EXTENDED SLIGHT CHANCE/CHANCE POPS UNCHANGED TO AWAIT TRENDS FROM 12Z MODEL RUNS. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 89 64 88 64 / 50 50 40 40 GALLUP.......................... 82 58 83 58 / 60 50 50 40 GRANTS.......................... 84 58 81 57 / 40 50 50 40 GLENWOOD........................ 84 63 84 62 / 50 60 50 40 CHAMA........................... 81 53 77 50 / 60 60 50 40 LOS ALAMOS...................... 79 57 83 57 / 40 40 50 40 RED RIVER....................... 77 47 72 46 / 50 40 50 30 TAOS............................ 82 54 82 54 / 30 30 50 30 SANTA FE........................ 81 57 81 59 / 40 30 50 30 SANTA FE AIRPORT................ 83 59 83 60 / 30 30 40 30 ESPANOLA........................ 85 59 88 60 / 30 20 30 20 ALBUQUERQUE HEIGHTS............. 88 67 87 67 / 30 30 40 30 ALBUQUERQUE VALLEY.............. 91 64 89 65 / 30 30 40 30 ALBUQUERQUE FOOTHILLS........... 86 63 84 63 / 40 30 40 30 ALBUQUERQUE WEST MESA........... 90 65 88 65 / 30 30 40 30 SOCORRO......................... 89 64 88 63 / 30 30 40 30 SANDIA PARK/CEDAR CREST......... 80 55 79 57 / 40 30 50 30 MORIARTY/ESTANCIA............... 82 57 85 58 / 30 30 40 20 CARRIZOZO....................... 84 60 83 61 / 30 30 30 30 RUIDOSO......................... 74 52 76 54 / 50 40 50 30 RATON........................... 81 57 81 58 / 30 20 30 30 LAS VEGAS....................... 78 56 78 56 / 20 20 30 30 ROY............................. 80 61 86 63 / 10 20 20 20 CLAYTON......................... 85 63 89 64 / 10 10 20 10 SANTA ROSA...................... 85 61 90 64 / 20 20 20 20 TUCUMCARI....................... 87 66 92 68 / 20 10 10 10 FORT SUMNER..................... 84 65 91 66 / 20 20 10 10 CLOVIS.......................... 81 64 88 65 / 30 20 10 10 PORTALES........................ 83 65 90 66 / 30 30 10 10 ROSWELL......................... 84 66 90 68 / 50 30 20 10 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 42 nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 300 AM MDT THU AUG 2 2007 .DISCUSSION... 12Z SFC ANALYSIS EARLY THIS MORNING SHOWS 1017MB HIGH PRES OVER SE CO NOSING SW INTO NE NM. 400-250MB AIRCRAFT DATA SHOWS A 30-40 KNOT NW TO SE ORIENTED JET FROM KFMN SE ACROSS KROW INTO KMAF. RADAR TRENDS SHOW INCREASING ACTIVITY ACROSS MUCH OF THE E PLAINS AND OVER PORTIONS OF THE CENTRAL VALLEY. LATEST RUC GUIDANCE INDICATES THE UPPER JET WILL TRANSLATE SE TOWARD W TX AND DISSIPATE THROUGH THE EARLY MORNING HOURS AS THE 500-300MB UPPER HIGH MOVES WESTWARD INTO SW NM. RAISED POPS TO HIGH CHANCE/LOW LIKELY IN AREAS E OF THE CENTRAL MTN CHAIN FOR THIS MORNING SINCE CONVECTION SHOULD HOLD TOGETHER AS UPPER DIVERGENCE ASSCD WITH EXITING UPPER JET MOVES ACROSS THE AREA. LOCALLY HEAVY RAINS ARE POSSIBLE WITH ANY STORMS TODAY...ESPECIALLY ACROSS THE E PLAINS AND SW MTNS AS GOES PWATS SHOW VALUES 150 PERCENT OF NORMAL IN THESE AREAS. THETA E RIDGE CURRENTLY POSITIONED FROM SE TO NW ACROSS THE SW HALF IS ADVERTISED TO BECOME MORE NORTH TO SOUTH ORIENTED INTO FRIDAY WITH THE BEST LIFT AND MOISTURE CONVERGENCE TO FOLLOW. LEFT HIGHEST POPS OVER THE W HALF OF THE STATE THROUGH WEEKEND AS ADVERTISED BY THE 00Z NOGAPS/GFS/UKMET. AN UPPER TROUGH IS PROGGED TO BUILD ALONG THE WEST COAST PUSHING THE UPPER HIGH EAST INTO THE CENTRAL PLAINS STATES. THIS TREND INDICATES THE MOISTURE PLUME WILL SLOWLY SHIFT FROM WEST TO EAST ACROSS THE STATE EARLY NEXT WEEK WITH DAILY ROUNDS SHOWERS AND STORMS. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 92 64 91 65 / 30 30 40 40 GALLUP.......................... 85 56 83 56 / 30 30 40 40 GRANTS.......................... 87 57 85 56 / 20 30 40 40 GLENWOOD........................ 85 61 85 61 / 40 30 50 50 CHAMA........................... 80 48 79 50 / 30 50 50 40 LOS ALAMOS...................... 84 56 82 56 / 40 50 40 40 RED RIVER....................... 73 44 76 44 / 60 50 50 40 TAOS............................ 85 53 85 53 / 40 30 30 30 SANTA FE........................ 83 57 84 58 / 40 40 40 30 SANTA FE AIRPORT................ 86 60 86 60 / 40 40 30 30 ESPANOLA........................ 90 61 89 59 / 20 30 20 30 ALBUQUERQUE HEIGHTS............. 89 66 89 65 / 30 40 30 30 ALBUQUERQUE VALLEY.............. 90 64 91 63 / 30 40 30 30 ALBUQUERQUE FOOTHILLS........... 86 62 87 62 / 30 40 30 30 ALBUQUERQUE WEST MESA........... 91 64 90 65 / 30 40 30 30 SOCORRO......................... 90 64 90 63 / 20 30 30 20 SANDIA PARK/CEDAR CREST......... 80 56 81 56 / 50 50 40 40 MORIARTY/ESTANCIA............... 84 53 84 52 / 50 60 30 20 CARRIZOZO....................... 83 61 84 61 / 40 60 30 20 RUIDOSO......................... 75 55 75 55 / 60 60 50 20 RATON........................... 85 55 86 57 / 50 50 20 20 LAS VEGAS....................... 80 52 82 54 / 60 40 30 20 ROY............................. 81 59 84 60 / 50 50 20 20 CLAYTON......................... 85 61 87 62 / 40 30 20 10 SANTA ROSA...................... 87 62 87 63 / 60 50 20 20 TUCUMCARI....................... 87 67 90 68 / 50 40 20 20 FORT SUMNER..................... 87 65 89 66 / 60 50 20 20 CLOVIS.......................... 85 63 85 64 / 60 30 20 10 PORTALES........................ 88 64 87 65 / 60 30 20 10 ROSWELL......................... 88 68 88 68 / 50 50 40 20 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 138 PM EDT FRI AUG 3 2007 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL CROSS THE AREA THROUGH THIS EVENING...BRINGING THE CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WITH DRIER AIR WILL BUILD INTO THE AREA LATER TONIGHT AND REMAIN THROUGH SUNDAY. A MORE ACTIVE PATTERN WILL BEGIN THE WORK WEEK WITH CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SLOW MOVING COLD FRONT STRETCHES ACROSS SRN ONTARIO PROVINCE SWD THRU LOWER MI AS OF MID MORNING. OBVIOUSLY A VERY WARM AND UNSTABLE AIRMASS OUT AHEAD OF THE BOUNDARY WITH MODIFIED BUF SOUNDING THIS MORNING SHOWING CAPES UP TO 2800 J/KG. THE MODEL WIND FIELDS ARE NOT OVERLY IMPRESSIVE, BUT RUC 500MB WINDS OF 30-35 KNTS OVER LOWER ONTARIO THIS MORNING IS HIGHER THAN MODELS. ANOTHER FACTOR IS THAT BEST S/W ENERGY IS MOVING EAST OF THE FA THIS MORNING, BUT NAM HINTS AT ANOTHER WEAKER WAVE PSBLY MOVING THRU THIS AFTN AND LOCAL WRF MODEL IS ALL FOR BLOWING UP CONVECTION ACROSS THE AREA. MUCH DRIER AND STABLE AIR OVER MI MAY BE ABLE TO CAP OFF WESTERN ZONES AS IT MOVES EAST...SO COULD SEE THE BEST CHC FOR STORMS ACROSS SUSQUEHANNA REGION...EAST THRU THE MOHAWK VALLEY AND WESTERN CATSKILLS. AREA WILL BE UNDER THE INFLUENCE OF RR QUAD OF UPPER JET THIS AFTN...AND WITH AMT OF CAPE AND WEAK BOUNDARY APPROACHING THE REGION...THERE IS CHC FOR AT LEAST A FEW STORMS TO REACH SEVERE LEVELS WITH DAMAGING WINDS AND LARGE HAIL. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... FRONT WILL CONTINUE PUSHING THROUGH WITH THE CHANCE FOR CONVECTION CONTINUING. ACTIVITY WILL END ACROSS NYS BY EARLY EVENING AND AROUND MIDNIGHT IN THE POCONOS AND WYOMING VALLEY. BEHIND FRONT DRIER AIR WILL BUILD IN AS HIGH PRESSURE OVER THE UPPER GREAT LAKES SLIDES EAST. SATURDAY/SATURDAY NIGHT WILL BE MOSTLY SUNNY/MAINLY CLEAR AS SFC HIGH PRESSURE MOVES EAST ACROSS NEARBY SOUTHERN ONTARIO/QUEBEC. MAX TEMPS ON SATURDAY WILL BE NEAR OR SLIGHTLY ABOVE NORMAL BUT LOWER DEW POINTS WILL MAKE IT FEEL FAIRLY COMFORTABLE. SUNDAY WILL START MOSTLY SUNNY THEN INCREASING CLOUDS FROM SOUTHWEST TO NORTHEAST AS LOW PRESSURE MOVING INTO THE GREAT LAKES PRODUCES MID LEVEL WAA. WILL CONTINUE WITH DRY FORECAST AS BEST ISENTROPIC LIFT AND MOISTURE WILL REMAIN WEST OF FA THROUGH 00Z MON. TEMPS SUNDAY WILL GENERALLY RANGE IN THE LOWER 80S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... LARGE SCALE PATTERN IS MORE ZONAL AT UPPER LEVELS OVER THE NORTHERN U.S. THRU THE PERIOD WITH VARIOUS SFC FEATURES CROSSING SRN CANADA AND AFFECTING THE NORTHERN TIER STATES. CONFIDENCE ON TIMING OF THESE SYSTEMS THIS FAR IS NOT HIGH. AT THIS POINT...LOOKS LIKE BEST PRECIP CHCS ARE TO OCCUR SOMETIME SUNDAY NIGHT, THEN AGAIN ON WEDNESDAY. HAVE INDICATED JUST LOW CHC POPS ATTM SINCE TIMING IS LIKELY TO CHANGE. TEMPS LOOK TO REMAIN A FEW DEGREES ABOVE NORMAL WITH LOW TO MID 80S PREVAILING FOR MAXES. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... NUMEROUS TSRA THIS AFTN/EVNG WITH MVFR TO IFR CONDITIONS. IMPVMNT LATER THIS EVENING AS ACTIVITY MOVS OUT AND DIES DOWN. FOG LIKELY TNGT...MVFR MOST SPOTS BUT DENSER AT ELM WHERE IFR TO LIFR CONDITIONS ARE XPCTD BETWEEN 08-12Z. VFR ALL SITES ON SAT. WINDS GNRLY WRLY 10-15 KTS THIS AFTN BUT G35 PSBL NEAR STRONGER TSRA. NW WINDS ARND 10 KTS ON SAT. ANOTHER FRONTAL SYSTEM LATER SUNDAY MAY BRIEFLY LOWER CIGS AND VISBY IN SHRA/TSRA. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...RRM NEAR TERM...JML SHORT TERM...RRM LONG TERM...JML AVIATION... ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 900 PM EDT FRI AUG 3 2007 .SYNOPSIS... WEAK LOW PRESSURE OVER GEORGIA THIS AFTERNOON WILL GRADUALLY MOVE OVER PORTIONS OF SC TONIGHT. OTHERWISE...ANOTHER AREA OF WEAK LOW PRESSURE WILL DEVELOP OFF THE CAROLINA COAST AND WEAKEN AS IT DRIFTS OFF TO THE NORTHEAST. AN AXIS OF MOISTURE WILL REMAIN OVER THE EASTERN CWA THROUGH SATURDAY...THEN AN UPPER RIDGE WILL BUILD IN FROM THE SOUTHWEST THROUGH THURSDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... DIFFUSE AREA OF LOW PRESSURE IN SW GA IS EXPECTED TO MOVE ENE DURING THE PD. MAIN FCST ISSUE OVERNIGHT IS HOW FAR N INTO THE CWA THIS WILL MANAGE TO SPREAD PRECIP. RUC HAS PREVIOUSLY BEEN OVERFORECASTING THIS TREND BUT IS SEEMINGLY BECOMING BETTER INTIALZIED WITH THE CONVECTION NOW OCCURRING NEAR THE SC/GA BORDER. NEWER RUNS KEEP ALL MEASUREABLE RAIN IN EXTREME SRN ZONES MUCH AS DEPICTED IN CONTINUITY. WILL STILL SHOW SOME SLGHT CHANCE POPS FARTHER N ALONG THE COAST AS THE NAM AND GFS STILL SHOW A RATHER IMPRESSIVE NOCTURNAL CONVECTIVE SIGNAL JUST OFFSHORE...SOME OF WHICH MAY GLANCE THE COAST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... WEAK LOW PRESSURE AND WEAKENING FRONTAL BOUNDARY WILL START OUT THE PERIOD WITH BEST CHANCES OF PCP ALONG THE BOUNDARY ACROSS SOUTHERN PORTIONS OF CWA EXTENDING INTO COASTAL WATERS. KEPT BEST CHC OF PCP ALONG THE COAST FOR TOMORROW. BY SUNDAY...WEAK SFC LOW DRIFTS OFF SHORE AND HEIGHTS BUILDING ALOFT...KEEPING AREA ON BACK END OF MID TO UPPER TROUGH AND LOWER CHC OF PCP. KEPT MAX TEMPS SLIGHTLY COOLER ON SAT WITH MORE CLOUDS AND SHOWERS IN AREA..ESPECIALLY ALONG COASTAL SECTIONS. TEMPS UP INTO THE MID 90S IN MOST PLACES ON SUNDAY WITH SLIGHTLY LOWER TEMPS ALONG THE COAST. && .LONG TERM /MONDAY THROUGH FRIDAY/... 5H RIDGE AND PIEDMONT TROF WILL REMAIN SEMI-PERMANENT FEATURES THROUGH THE LONG TERM PERIOD. SUBSIDENCE UNDER THE RIDGE WILL KEEP TEMPERATURES ABOVE CLIMO AND POPS SLIGHTLY BELOW CLIMO. BOTH GFS/ECMWF SHOWING 850 TEMPS LATE IN THE PERIOD AT OR ABOVE 20C. GUIDANCE SHOWS WEAK SURFACE LOW OFF THE COAST AT THE START OF THE PERIOD BUT FLOW AROUND THE UPPER RIDGE WILL PUSH THIS FEATURE WELL SOUTHEAST OF THE REGION. WARMEST TEMPERATURES WILL BE WEDNESDAY AND THURSDAY WHEN 5H RIDGE IS THE STRONGEST. THESE DAYS WILL ALSO HAVE THE LEAST LIKELY CHANCE OF SEEING PRECIP DEVELOP...EVEN ALONG THE ANTICIPATED SEA BREEZE. && .AVIATION /00Z SATURDAY THROUGH THURSDAY/... GIVEN THAT LBT WENT DOWN IN FOG LAST NIGHT...AND THE FACT THAT THERE WILL BE LESS CLOUD COVER INLAND...COULD SEE SOME RADIATION MVFR/IFR FOG FOR LBT AND FLO...HOWEVER CONFIDENCE IS NOT HIGH. BOUNDARY ON RADAR PASSED NORTHWEST TO SOUTHEAST EARLY THIS EVENING...SUPPRESSING PRECIP SOUTH OF THE CWA. THINK PRECIP WILL CONTINUE TO BE SUPPRESSED TO THE SOUTH OVERNIGHT...PERHAPS AFFECTING MYR AND CRE JUST AFTER SUNRISE AS THE MOISTURE TRIES TO WAVE NORTH. INTERACTION WITH THE SEA BREEZE AROUND 15-17Z SHOULD ENHANCE WHATEVER SCATTERED CONVECTION IS AROUND. ISOLATED CONVECTION SUNDAY...SCATTERED MONDAY AND TUESDAY...WITH LITTLE OR NO CONVECTION WEDNESDAY AND THURSDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... A LITTLE UNCERTAINTY WITH WIND SPEED AND DIRECTION THIS PD STEMMING FROM THE LOW IN SW GA THAT WILL LIFT TO THE ENE. A GENERAL SRLY DIRECTION SHOULD CONTINUE WITH A BACKING FROM SW TO SE POSSIBLE. SPEEDS SHOULD STAY CAPPED AT 15 KTS. SPEEDS HAVE BEEN BUMPED UP A FEW KTS FROM PREV FCST AS KCLX VWP/INCREASED STORM STRUCTURE NEAR SC/GA BORDER AND OCP7 BOUY ALL SUGGEST THAT SOME COASTAL JETTING MAY BE OCCURRING. SHORT TERM /SATURDAY MORNING THROUGH SUNDAY NIGHT/... THE WIND FIELD ACROSS THE WATERS WILL BECOME TRICKY AS WRF CONTINUES TO SHOW ANOTHER WEAK LOW TO DRIFT ACROSS GA INTO SC SATURDAY THROUGH SATURDAY NIGHT. MAINLY REMAIN IN SOUTHERLY FLOW...BUT DEPENDING ON MOVEMENT OF LOW PRESSURE OFF THE COAST ON SATURDAY NIGHT...WILL SEE A PERIOD OF ON SHORE WINDS SAT NIGHT INTO SUNDAY MORNING WITH WINDS INCREASING TO AROUND 15 KTS BUILDING SEAS UP TO AROUND 4 FT IN OFF SHORE WATERS. OTHERWISE SEAS 2 TO 4 FT AND WINDS 10 TO 15 KTS. LONG TERM /SUNDAY THROUGH MONDAY/... SURFACE FLOW WILL REMAIN LIGHT AND FROM THE SOUTH/SOUTHEAST THROUGH THE PERIOD WITH BERMUDA HIGH OFF THE COAST AND PIEDMONT TROF INLAND. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...MBB SHORT TERM...RGZ LONG TERM...III AVIATION...DL nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 246 PM EDT FRI AUG 3 2007 .SYNOPSIS... AN AREA OF LOW PRESSURE ALONG THE FLORIDA GULF COAST IS EXPECTED TO REMAIN SOUTH OF THE AREA AS IT SLOWLY MOVES OFF THE SOUTHEAST COAST THIS WEEKEND. ABOVE NORMAL TEMPERATURES AND BELOW NORMAL CHANCES FOR PRECIPITATION ARE EXPECTED TO CONTINUE ACROSS CENTRAL NORTH CAROLINA THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... SFC ANALYSIS THIS AFTERNOON SHOWS A WEAK 1015MB AREA OF LOW PRESSURE IN SOUTHERN GA. A SFC TROUGH ASSOC/W THE LOW EXTENDED NE ALONG THE SOUTHEAST COAST. A LEE TROUGH AXIS WAS LOCATED OVER CENTRAL NC...STRETCHING NNE INTO EASTERN PA. DEWPOINTS ACROSS CENTRAL NC RANGED FROM 60F IN THE TRIAD TO 70F IN THE FAR SE COASTAL PLAIN. ALOFT...A DEEP RIDGE WAS LOCATED OVER THE DESERT SOUTHWEST...WITH TROUGHING OVER THE GREAT LAKES AND EASTERN US. AT 250MB...A TROUGH WAS LOCATED ALONG AND JUST WEST OF THE SOUTHERN APPALACHIANS... EXTENDING FROM WV SOUTH THROUGH EASTERN TN...NORTHERN GA...AL AND THE FL PANHANDLE. A SHORTWAVE WAS NOTED FURTHER UPSTREAM OVER IN/OH...FURTHER CONFIRMED BY RUC 250MB HEIGHT/VORT FIELDS WHICH SHOW A VORT MAX IN THIS LOCATION. MOISTURE AND INSTABILITY THIS AFT/EVE... THE 12Z GSO SOUNDING SHOWS A MOISTENING ATMOSPHERE...WITH A 1.33" PWAT (COMPARED TO 1.07" YESTERDAY). THE REASON FOR THIS CAN BE SEEN IN WV IMAGERY...WHICH SHOWS MOISTURE ALOFT STREAMING N/NE INTO SC/NC FROM THE FL GULF COAST. THE 12Z MHX SOUNDING IS SIMILAR...WITH A 1.50" PWAT TODAY COMPARED TO 1.04" YESTERDAY. OF NOTE IN THE GSO SOUNDING IS THE ABSENCE OF THE MID-LEVEL SUBSIDENCE INVERSION EVIDENT IN THE SOUNDING YESTERDAY...WITH 650MB TEMPS ABOUT 3C COLDER TODAY VERSUS YESTERDAY. THE OBSERVED SOUNDINGS THIS MORNING AND FCST SOUNDINGS FOR THIS AFTERNOON SHOW DEEP MIXING LIKELY AGAIN...WITH DEWPOINTS DROPPING THIS AFTERNOON INTO THE LOWER 60S. WITH TEMPS IN THE LOWER/MID 90S AND DEWPOINTS IN THE LOWER 60S...WEAK INSTABILITY IS FCST THIS AFTERNOON...WITH SFC BASED CAPE VALUES LESS THAN 1000 J/KG. SFC AND UPPER LEVEL LIFT THIS AFT/EVE... SSE WINDS ON THE COAST AND ENE WINDS IN THE COASTAL PLAIN INDICATE A SFC CONVERGENCE AXIS THAT WILL SERVE AS A FOCUS FOR DEVELOPMENT THIS AFTERNOON...ALTHOUGH THIS WILL LIKELY REMAIN JUST SOUTH/EAST OF CENTRAL NC NEAR THE COAST. SFC CONVERGENCE ASSOC/W THE LEE TROUGH AXIS OVER CENTRAL NC WILL SERVE AS THE PRIMARY FOCUS FOR DEVELOPMENT THIS AFTERNOON. ALOFT...THERE IS A WELL-DEFINED TROUGH JUST WEST OF THE MOUNTAINS PER 12Z RAOB DATA...AND RUC 250MB HEIGHT/VORT FIELDS SHOW AN ELONGATED VORTMAX ASSOC/W THIS FEATURE...HOWEVER...IT DOES NOT APPEAR THAT THIS WILL MOVE MUCH DURING THE DAY ACCORDING TO SHORT TERM MODEL PROGS. THE RUC DOES SHOW THE VORTMAX ASSOC/W THE 250MB SHORTWAVE CURRENTLY UPSTREAM OVER IN/OH DIVING SOUTHEAST TOWARD NC/VA LATER THIS EVENING...AND THIS COULD PROVIDE SOME BENEFICIAL DIFFERENTIAL PVA. SUMMARY FOR THIS AFT/EVE... THE THERMODYNAMICS HAVE IMPROVED TODAY...WITH HIGHER PWAT VALUES AND COOLER MID-LEVEL TEMPS WHEN COMPARED TO YESTERDAY. DIURNAL MIXING HAS ALLOWED DEWPOINTS TO DROP INTO THE LOWER 60S OVER MOST OF CENTRAL NC AGAIN (EXCEPT THE FAR SE COASTAL PLAIN)...AND THIS WILL SERVE TO LIMIT THE AMOUNT OF INSTABILITY TO MARGINAL LEVELS THE REMAINDER OF THIS AFT/EVE. HOWEVER...THE COMBINATION OF MARGINAL INSTABILITY AND SFC CONVERGENCE ASSOC/W THE LEE TROUGH AXIS HAS APPARENTLY BEEN ENOUGH FOR ISOLATED SHOWER DEVELOPMENT TO OCCUR... WITH LATEST RADAR/SAT IMAGERY CONFIRMING A FEW ISOLATED SHOWERS ALONG AND WEST OF US 1 THIS AFTERNOON. THEREFORE...WILL ADD A SLIGHT CHANCE OF A SHOWER ACROSS THE ENTIRE FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON...ENDING JUST BEFORE SUNSET. SHOWER ACTIVITY WILL BE BRIEF AND ISOLATED...AND THE BEST CHANCE WILL BE WEST OF US 1 AND NORTH OF HWY 64. -VINCENT && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... UPPER LEVEL RIDGING OVER THE WEST COAST SHIFTS EAST INTO THE MIDWEST DURING THE SHORT TERM PERIOD...AND FLOW ALOFT OVER THE MID-ATLANTIC BECOMES NW OR WNW ON THE EASTERN PERIPHERY OF THE RIDGE. THE GFS/NAM ARE IN BETTER AGREEMENT ON HOW TO HANDLE THE SFC LOW CURRENTLY IN SOUTHERN GA...KEEPING THE LOW SOUTH OF NC AND TAKING IT EAST INTO THE ATLANTIC OFF THE GA/SC COAST BY SUNDAY AFTERNOON. SATURDAY... CHANCES FOR PRECIP APPEAR VERY SLIM ON SATURDAY...WITH A FEW ISOLATED SHOWERS POSSIBLE DURING PEAK HEATING...AND THAT`S ONLY IF THE MID-LEVELS DO NOT WARM UP AND A THERMAL TROUGH DEVELOPS AND PROVIDES A FOCUS IN THE FORM OF SFC CONVERGENCE...SIMILAR TO TODAY. A BLEND OF MAV/MET GUIDANCE AND THICKNESSES IN THE 1430-1435M RANGE INDICATE HIGH TEMPS IN THE 94-98F RANGE...ABOUT 5-8F ABOVE NORMAL. SUNDAY... THE GFS/NAM ARE IN BETTER AGREEMENT ON BRINGING IN REMNANT MCS ACTIVITY THAT DEVELOPS ALONG A BOUNDARY IN THE OHIO VALLEY SUNDAY AFT/EVE. FOR THIS REASON...WILL KEEP A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE AREA SUN AFT/EVE...AND THIS MAY NEED TO BE INCREASED INTO THE CHANCE CATEGORY IF SUBSEQUENT MODEL RUNS CONTINUE TO INDICATE SUCH A SCENARIO OCCURRING. GFS/NAM THICKNESSES ARE STILL RUNNING IN THE 1430-1435M RANGE...HOWEVER...CLOUD COVER ASSOC/W CONVECTION THAT WILL BE RIDING AROUND THE EASTERN PERIPHERY OF THE RIDGE INTO THE AREA SHOULD HELP KEEP TEMPS A BIT LOWER THAN ON SAT...BUT STILL ABOVE NORMAL WITH HIGHS IN THE 93-96F RANGE. MONDAY... THE DEEP UPPER RIDGE OVER THE MIDWEST BEGINS TO SHIFT FURTHER EAST...WITH HEIGHTS RISING OVER CENTRAL NC ON MONDAY. THE GFS INDICATES NW FLOW ALOFT WILL REMAIN OVER THE AREA. IT APPEARS THERE WILL BE BETTER LOW LEVEL MOISTURE AROUND MON AFTERNOON...AND THIS IN ADDITION TO THE POSSIBILITY OF SHORTWAVE ENERGY DROPPING INTO THE AREA VIA NW FLOW ALOFT WILL ALLOW FOR A CHANCE OF SHOWERS/STORMS... PRIMARILY DURING THE NORMAL PEAK HEATING HOURS. HIGH TEMPS CONTINUED ABOVE NORMAL IN THE MID 90S. -VINCENT && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... MUCH OF NEXT WEEK STILL LOOKS UNSEASONABLY WARM AND DRY AS THE WESTERLIES HOLD PRIMARILY TO OUR NORTH. WE`VE BEEN WATCHING THE POTENTIAL FOR A MESOSCALE CONVECTIVE VORTEX ORIGINATING FROM UPPER MIDWEST MCS ACTIVITY AND DROPPING AROUND THE NORTHEAST SIDE OF THE MID LEVEL RIDGE LATE SUNDAY THROUGH MONDAY...PASSING NEAR AND JUST NORTHEAST OF NC. THIS FEATURE... IF IT COMES TO PASS... SHOULD BE OUT OF THE AREA PRIOR TO MONDAY NIGHT... ALTHOUGH LINGERING CLOUDINESS ESPECIALLY OVER NORTHEAST NC IS EXPECTED. OTHERWISE... MID LEVEL HEIGHTS CONTINUE TO RISE OVER THE REGION TUESDAY THROUGH FRIDAY WITH THE GLOBAL ENSEMBLES STILL SHOWING VALUES 1-2 STANDARD DEVIATIONS ABOVE NORMAL INTO FRIDAY. FORECAST SOUNDINGS INDICATE A PERSISTENT STABLE LAYER AT 700-400 MB... ALTHOUGH WITH THIS DEGREE OF BOUNDARY LAYER HEATING AND NEAR NORMAL PRECIPITABLE WATER VALUES... MARGINAL POTENTIAL BUOYANCY MAY STILL BE ACHIEVED... ENOUGH TO CONTINUE ISOLATED STORM CHANCES EACH AFTERNOON. THE GFS CONTINUES TO SHOW A RETROGRESSIVE TREND OF THE MID LEVEL RIDGE CENTER... PRODUCING A WEAKNESS DOWN THE EAST COAST LATE IN THE PERIOD AND DROPPING A BACKDOOR FRONT TOWARD THE NC/VA BORDER. THE 00Z/03 ECMWF WAS MUCH MORE EMPHATIC WITH THIS TROUGHING... A DEPARTURE FROM THE HIGHER HEIGHTS OF ITS PREVIOUS RUN AND THE GFS... BUT IT DOES HAVE SUPPORT FROM THE CANADIAN. THIS SORT OF ANOMALOUSLY SOUTHWARD PUSH OF A COLD FRONT THIS TIME OF YEAR IS FAR FROM A SURE BET... AND FOR NOW HAVE ONLY RAISED SKY COVER A BIT ON FRIDAY WITH NO INCREASE IN POPS OR SHIFT IN WIND. THICKNESSES AND A DRY ADIABATIC LAPSE RATE IN THE LOWEST 2-3 KM STILL SUGGEST HIGHS ONE TO TWO CATEGORIES ABOVE NORMAL THROUGH THE PERIOD... YIELDING HIGHS INTO THE MID-UPPER 90S. TUESDAY/WEDNESDAY LOOK TO BE THE HOTTEST DAYS... AND WOULD NOT BE SURPRISED TO SEE A FEW 100 DEGREE HIGHS IN CENTRAL NC EITHER DAY. IF THE GFS TREND OF INCREASING DEWPOINTS PERSISTS AND APPEARS IMMINENT... HEAT INDICES COULD REACH ADVISORY LEVELS FOR A FEW DAYS IN A ROW. -GIH && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... WILL AGAIN LARGELY FOLLOW PERSISTENCE FOR THE TERMINAL FORECASTS. DESPITE LIMITED MOISTURE AND MARGINAL INSTABILITY... A FEW SHOWERS HAVE MANAGED TO DEVELOP ACROSS THE PIEDMONT AND MAY AFFECT KRDU... HOWEVER ANY CONVECTION SHOULD BE VERY ISOLATED. OTHERWISE... SCATTERED CUMULUS SHOULD PERSIST THIS AFTERNOON. WITH THE OLD FRONT EXTENDING FROM THE FL PANHANDLE NORTHEAST ALONG THE SOUTHEAST COAST... MID CLOUDS ARE ALSO LIKELY AT FAY. WITH THE LOSS OF HEATING THE CUMULUS SHOULD DISSIPATE THIS EVENING. EXPECT AT LEAST MVFR FOG TO RETURN LATER TONIGHT... PARTICULARLY AT KRWI/KFAY WHERE IFR FOG IS POSSIBLE... ALTHOUGH THE LOCAL FOG/STRATUS FORECASTING SCHEME SUGGESTS THAT FOG WON`T BE A MAJOR PROBLEM. OF BIGGER CONCERN AT KFAY MAY BE THE STRATOCUMULUS CURRENTLY OVER GA/SC COASTAL SECTIONS WHICH IS POISED TO ADVECT INTO SOUTHEAST NC TONIGHT INTO SATURDAY. HAVE KEPT THIS JUST A PERIOD OF SCATTERED-BROKEN VFR CLOUDS FOR NOW BUT AVIATION INTERESTS WILL NEED TO WATCH OUT FOR THIS CLOUDINESS NEAR AND SOUTH/EAST OF KFAY. ANY FOG SHOULD MIX OUT SATURDAY MORNING WITH FORECAST SOUNDINGS REMAINING LARGELY DRY... AND JUST SCATTERED DAYTIME CUMULUS IS AGAIN ANTICIPATED THROUGH 18Z SATURDAY. LOOKING AHEAD TO LATE FRIDAY AFTERNOON THROUGH MIDWEEK... ASIDE FROM AREAS OF PRIMARILY MVFR FOG AND HAZE LATE NIGHT THROUGH DAYBREAK EACH DAY... PRIMARILY VFR CONDITIONS ARE EXPECTED. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... AIR QUALITY ACTION DAY UNTIL 9 PM EDT THIS EVENING FOR NCZ021>023-038-039. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...VINCENT LONG TERM...HARTFIELD AVIATION...HARTFIELD nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 259 PM EDT THU AUG 2 2007 .SYNOPSIS... AN UPPER LEVEL RIDGE WILL BUILD ACROSS THE CENTRAL AND EASTERN U.S. THROUGH THE EARLY WEEKEND...KEEPING CONDITIONS WARM AND DRY ACROSS CENTRAL NORTH CAROLINA. && .NEAR TERM /THROUGH TONIGHT/... SFC ANALYSIS THIS AFTERNOON SHOWS 1018 MB HIGH PRESSURE CENTERED OVER THE MID-ATLANTIC...AND A WEAK AREA OF LOW PRESSURE LOCATED ALONG THE GULF COAST. DEWPOINTS WERE IN THE UPPER 50S TO MID 60S ACROSS CENTRAL NC...AND SKIES WERE MOSTLY CLEAR TO PARTLY CLOUDY. ALOFT...H25 ANALYSIS SHOWS WHAT APPEARS TO BE A VERY WEAK CYCLONIC CIRCULATION OVER CENTRAL VA. WV IMAGERY CONFIRMS THIS...SHOWING A WELL DEFINED CYCLONIC SWIRL THAT DROPPED SOUTH THROUGH WV OVERNIGHT INTO CENTRAL OR SOUTHWEST VA THIS MORNING. MOISTURE AND INSTABILITY THIS AFTERNOON... THE 12Z GSO SOUNDING TODAY SHOWS A DRY AIRMASS...WITH A PWAT OF 1.07"...VERSUS 1.44" YESTERDAY AT THIS TIME. ALSO OF NOTE THIS MORNING IS A MID-LEVEL SUBSIDENCE INVERSION...WITH TEMPS IN THE 600-700MB LAYER AS MUCH AS 4C WARMER THAN YESTERDAY. ALTHOUGH DEWPOINTS ARE CURRENTLY IN THE MID/UPPER 60S ACROSS CENTRAL NC... THEY ARE EXPECTED TO MIX OUT INTO THE LOWER 60S AND UPPER 50S DURING PEAK HEATING/MIXING THIS AFTERNOON. SO BASICALLY...A DRY COLUMN WITH A MID-LEVEL SUBSIDENCE INVERSION AND FALLING SFC DEWPOINTS WILL ALLOW ONLY MEAGER AMOUNTS OF INSTABILITY THIS AFTERNOON. SFC AND UPPER LEVEL LIFT THIS AFTERNOON... WITH HIGH PRESSURE CENTERED OVER THE MID-ATLANTIC...THERE WILL BE NO REAL SURFACE LIFT OR FOCUS THIS AFTERNOON. ALOFT...THERE IS A WELL DEFINED CYCLONIC SWIRL THAT SHOWS UP WELL IN WV IMAGERY AND IN H25 UPPER AIR ANALYSIS THIS MORNING...CURRENTLY LOCATED IN CENTRAL/SW VA. LOOKING AT THE LATEST WV IMAGERY...IT APPEARS THE SOUTHWARD PROGRESS OF THIS FEATURE HAS STALLED IN VA...AND ALTHOUGH RUC/NAM12 FCST HEIGHT AND VORTICITY FIELDS HAVE A TOUGH TIME PICKING UP ON IT...THEY DO SEEM TO SHOW ANY ENERGY OVER VA BEING KICKED OUT EASTWARD INTO THE ATLANTIC BY LATER THIS EVENING/TONIGHT. EITHER WAY...THERE IS NO MOISTURE ASSOC/W THIS FEATURE AND IT APPEARS THE BETTER LIFT WOULD BE FURTHER NORTH IN VA. SUMMARY FOR THIS AFTERNOON AND TONIGHT... THE COMBINATION OF MEAGER INSTABILITY...A VERY DRY ATMOSPHERIC COLUMN AND HIGH PRESSURE AT THE SURFACE WILL LARGELY PREVENT ANY CONVECTION OTHER THAN DIURNAL CU THIS AFTERNOON...EXCEPT FOR PERHAPS AREAS ALONG/NEAR THE VA BORDER THAT ARE CLOSER TO UPPER LEVEL LIFT ASSOC/W THE CYCLONIC SWIRL SEEN IN WV IMAGERY IN CENTRAL VA. ENHANCED CU CAN BE SEEN IN VIS SAT IMAGERY IN THESE AREAS. THEREFORE...TO COVER THE POSSIBILITY OF A FEW SPRINKLES OR A VERY BRIEF AND ISOLATED SHOWER...WILL INTRODUCE A 10% CHANCE OF -SHRA IN NORTHERN COUNTIES ALONG THE VA BORDER UNTIL 22-23Z...AND CONTINUE WITH A DRY FORECAST FOR THE REMAINDER OF THE AREA TODAY. HIGH TEMPS STILL IN THE 92-95F RANGE. OVERNIGHT...MOSTLY CLEAR SKIES WITH LOW TEMPS IN THE UPPER 60S. -VINCENT && .SHORT TERM /FRIDAY THROUGH SUNDAY/... UPPER LEVEL RIDGING OVER THE WEST COAST SHIFTS TOWARD THE MIDWEST DURING THE SHORT TERM PERIOD...AND FLOW ALOFT OVER THE MID-ATLANTIC BECOMES NW OR WNW. THE GFS/NAM ARE VERY DIFFERENT IN HOW THEY HANDLE THE AREA OF LOW PRESSURE CURRENTLY ALONG THE GULF COAST. THE GFS TAKES THE SYSTEM ALONG THE SE COAST JUST SOUTH OF THE AREA AND OUT INTO THE ATLANTIC BY SAT AFTERNOON...AND THE NAM KEEPS IT IN SOUTHERN AL/GA. EITHER WAY IT SEEMS LIKE THIS SYSTEM WILL GENERALLY REMAIN TOO FAR SOUTH OF CENTRAL NC TO PROVIDE ANY MOISTURE/LIFT FOR PRECIP. FRIDAY... BOTH THE NAM/GFS SHOW AN UPPER LEVEL WAVE CROSSING THROUGH CENTRAL NC SOMETIME BETWEEN FRIDAY EVENING AND SATURDAY MORNING. IF THE TIMING OF THIS FEATURE WAS DURING THE AFTERNOON ON FRIDAY...IT WOULD PROBABLY WARRANT A SLIGHT CHANCE OF SHRA/TSRA IN THE WESTERN HALF OF THE FORECAST AREA...HOWEVER...IT SEEMS LIKE THE TIMING OF THE BEST UPPER LEVEL LIFT ASSOC/W THE WAVE WILL MORE LIKELY BE AFTER SUNSET WHEN THE THERMODYNAMICS WOULD BE MUCH LESS SUPPORTIVE. FCST SOUNDINGS SHOW A MAXIMUM OF 500-1000 J/KG OF CAPE DURING FRIDAY AFTERNOON...WITH SFC DEWPOINTS AGAIN FALLING INTO THE UPPER 50S AND LOWER 60S DURING PEAK HEATING/MIXING. THEREFORE...AT THIS TIME WILL OPT TO LEAVE OUT ANY MENTION OF PRECIP ON FRIDAY. MOSTLY CLEAR SKIES EXPECTED ON FRI MORNING...WITH PARTLY CLOUDY SKIES AS DIURNAL CU DEVELOP IN THE AFTERNOON. BLEND OF MAV/MET GUIDANCE AND THICKNESSES INDICATE HIGH TEMPS IN THE 91-94F RANGE. SATURDAY AND SUNDAY... THERMODYNAMIC ENVIRONMENT DOES NOT SEEM TO CHANGE MUCH...WITH GFS/NAM FCST SOUNDINGS SHOWING VERY MARGINAL INSTABILITY (500-1000 J/KG OR LESS) WITH DEEP MIXING LAYERS AND DRY AIR ALOFT ALLOWING SFC DEWPOINTS TO CONTINUE TO FALL INTO THE 50S AND LOWER 60S DURING PEAK HEATING. AS LONG AS THE LOW CURRENTLY ALONG THE GULF COAST STAYS SOUTH OF THE AREA...THERE SHOULD BE NO SIGNIFICANT SURFACE OR UPPER LEVEL LIFT ON SAT/SUN. THERE WILL BE THE POTENTIAL FOR WEAK SHORTWAVES IN NW FLOW ALOFT TO RIPPLE INTO THE AREA...HOWEVER...AT THIS TIME IT DOES NOT APPEAR THE LIFT WITH THESE FEATURES WOULD BE SUFFICIENT FOR THE DEVELOPMENT OF CONVECTION GIVEN THE WEAK THERMODYNAMICS PROGGED IN THE FCST SOUNDINGS. THE GFS SHOWS MCS ACTIVITY ASSOC/W A SURFACE LOW AND BOUNDARY THAT DEVELOP IN THE MIDWEST AND OHIO VALLEY ON SAT/SUN. IT IS POSSIBLE THAT REMNANT MCS ACTIVITY OR AN MCV COULD ADVECT INTO THE AREA FROM THE N/NW SUNDAY AFT/EVE...ALTHOUGH AT THIS TIME THE GFS KEEPS ANY PRECIP WELL NORTH OF THE AREA. WILL CONTINUE A SLIGHT (20%) CHANCE OF CONVECTION ACROSS THE AREA SUN AFT/EVE DUE TO THE ABOVE-MENTIONED MCS/MCV POSSIBILITY...WITH A REMINDER THAT THIS IS PROBABLY A LONG SHOT AND BELOW CLIMATOLOGY FOR POPS THIS TIME OF YEAR. HIGH TEMPS ABOVE NORMAL ON SAT/SUN...IN THE MID 90S. -VINCENT && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... MUCH OF NEXT WEEK STILL LOOKS UNSEASONABLY WARM AND DRY AS THE WESTERLIES HOLD PRIMARILY TO OUR NORTH. THE GFS/ECMWF/CANADIAN INDICATE A POSSIBLE MESOSCALE CONVECTIVE VORTEX ORIGINATING FROM UPPER MIDWEST MCS ACTIVITY AND DROPPING AROUND THE NORTHEAST SIDE OF THE MID LEVEL RIDGE LATE SUNDAY THROUGH MONDAY MORNING... MOST LIKELY PASSING NEAR AND NORTH OF NC BASED ON THE MEAN CLOUD LAYER FLOW. THE OCCURRENCE... MOVEMENT... AND ULTIMATE EFFECTS OF ANY SUCH FEATURE REMAIN QUITE UNCERTAIN AT THIS RANGE... AND WILL RETAIN ENHANCED CLOUD COVER AND SLIGHT CHANCE POPS FOR NOW. IF THE 06Z GFS TREND OF GREATER INSTABILITY AND BETTER MOISTURE THROUGH THE COLUMN PERSISTS FOR ANOTHER FEW RUNS... POPS AND CLOUDS MAY NEED TO BE INCREASED FURTHER. THEN MONDAY NIGHT ONWARD... MID LEVEL HEIGHTS CONTINUE TO RISE OVER THE REGION WITH THE GEFS STILL SHOWING VALUES 1-2 STANDARD DEVIATIONS ABOVE NORMAL. FORECAST SOUNDINGS INDICATE FAIRLY STABLE AIR ALOFT... ALTHOUGH WITH THIS DEGREE OF BOUNDARY LAYER HEATING... MARGINAL POTENTIAL BUOYANCY MAY STILL BE ACHIEVED... ENOUGH TO CONTINUE ISOLATED STORM CHANCES EACH AFTERNOON. THE LATEST GFS/ECMWF SHOW A RETROGRESSIVE TREND OF THE MID LEVEL RIDGE CENTER... PRODUCING A WEAKNESS DOWN THE EAST COAST LATE IN THE PERIOD AND DROPPING A BACKDOOR FRONT TOWARD THE NC/VA BORDER. THIS IS FAR FROM A SURE BET AND HAVE ONLY RAISED SKY COVER TO PARTLY-MOSTLY CLOUDY FOR NOW WITH NO INCREASE IN POPS OR SHIFT IN WIND. THICKNESSES AND A DRY ADIABATIC LAPSE RATE IN THE LOWEST 2-3 KM SUGGEST HIGHS ONE TO TWO CATEGORIES ABOVE NORMAL THROUGH THE PERIOD... TYPICAL FOR THIS SORT OF PATTERN. -GIH && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... PERSISTENCE APPEARS TO BE THE BEST FORECAST FOR AVIATION CONCERNS. WITH HIGH PRESSURE DOMINATING AT THE SURFACE... EXPECT A CONTINUATION OF A GENERALLY DRY COLUMN AND WARM STABLE AIR IN THE MID LEVELS. STRONG HEATING OF THE BOUNDARY LAYER WITH THE MOISTURE IN PLACE IN THE LOWEST FEW KM WILL KEEP SCATTERED TO BROKEN VFR CUMULUS OVER THE TAF SITES THROUGH THE LATE AFTERNOON... FOLLOWED BY CLEARING... AND THE DEVELOPMENT OF MAINLY MVFR FOG AND HAZE OVERNIGHT. POCKETS OF IFR VISIBILITIES ARE EXPECTED AT RWI AND FAY WHERE SURFACE DEWPOINTS HAVE BEEN AND ARE EXPECTED TO REMAIN HIGHER AS COMPARED TO INT/GSO/RDU... AND LOCAL INFLUENCES OF NEARBY CREEKS AT RWI COULD PRODUCE BANKS OF LIFR FOG THERE LATE TONIGHT. VISIBILITIES SHOULD THEN IMPROVE TO VFR WITHIN AN HOUR OR TWO AFTER DAYBREAK... AND WILL AGAIN BE FOLLOWED BY SCATTERED TO BROKEN CUMULUS THROUGH 18Z FRIDAY. THE MODELS INDICATE VERY LIGHT MAINLY EAST TO SOUTHEAST FLOW SHIFTING TO SOUTHEAST TO SOUTH FOR FRIDAY... BUT REMAINING AT 8 KTS OR LESS AND LARGELY DIFFLUENT... HAMPERING ATTEMPTS OF DAYTIME HEATING TO INSTIGATE CONVECTION. OF INTEREST HOWEVER IS THE GFS WHICH BRINGS THE LOW PRESSURE OVER THE EASTERN GULF TOWARD THE NORTHEAST... ENHANCING THE ONSHORE FLOW INTO PLACES LIKE FAY. HAVE INCLUDED A PREVAILING BROKEN VFR SKY HERE PRIOR TO 18Z FRIDAY. LOOKING AHEAD TO FRIDAY NIGHT THROUGH EARLY NEXT WORK WEEK... ASIDE FROM AREAS OF PRIMARILY MVFR FOG AND HAZE LATE NIGHT THROUGH DAYBREAK EACH DAY... VFR CONDITIONS ARE EXPECTED. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...VINCENT LONG TERM...HARTFIELD AVIATION...HARTFIELD nc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 855 PM CDT FRI AUG 3 2007 .UPDATE... AT THIS TIME NO ADDITIONAL UPDATE WILL BE ISSUED. WATER VAPOR SHOWS ONE LONG PLUME OF MOISTURE FROM ARIZONA TO NRN COLORADO/WYOMING AND THEN ACROSS SOUTH DAKOTA. SEVERAL VORT MAXES IN THIS FLOW SETTING OFF CLUSTERS OF TSTMS. LATER TONIGHT MODELS INSIST ON INCREASING 850 MB JET BUT VARY IN SPEED FROM 40 KTS FROM GFS TO 50 KTS ON THE RUC OVER CNTL/ERN SD. THIS SHOULD HELP CLUSTERS OF TSTMS IN SOUTH DAKOTA CONTINUE TO ORGANIZE WITH THE RESULT BEING ONE LARGE COMPLEX OF HVY RAIN OVER MUCH OF SOUTH DAKOTA. RUC INSISTS NRN EDGE OF DEVELOPMENT WILL REACH FAR SE ND AFTER 06Z SO WILL MAINTAIN CHC POPS OVER MY SOUTH. ADDITIONALLY WATER VAPOR SHOWS UPR LOW OVER THE BRITISH COLUMBIA/ALBERTA PEACE DISTRICT WEST OF EDMONTON WITH SRN EDGE OF MOISTURE AND 300 MB JET MOVING FROM ACROSS MONTANA INTO SASK. THIS WOULD PUT CNTRL/WRN ND IN SOME UPPER LEVEL DIVERGENCE AND THUS SUPPORT ONGOING CONVECTION THAT HAS BEEN PRESENT FROM FAR ERN MT INTO DVL REGION. MOVEMENT HAS BEEN VERY VERY SLOW AND THUS LOCALLY HVY RAINS HAS OCCURRED. WOULD EXPECT STORMS IN NORTH DAKOTA TO CONTNUE TONIGHT BUT GRADUALLY WEAKEN IN TIME WITH SOUTH DAKOTA ACTIVITY TAKING OVER. NO 12Z OR 18Z MODELS/SREF HAD HANDLE ON ND CONVECTION SO CONFIDENCE IN EVOLUTION IS NOT THAT GREAT. WILL MAINTAIN HIGH CHC POPS THRU 06Z FOR DVL REGION AND THEN LOWER CHANCES AFTERWARDS. CONTINUE LOW CHC POPS INTO NRN RED RIVER VALLEY FOR ANYTHING THAT MAY MAKE IT EAST AND ACROSS MY SOUTH PER OVERNIGHT POSSIBLE TSTMS. CURRENT FCST LOW TEMPS/DEW PTS APPEAR FINE ATTM. && .PREV DISCUSSION... /ISSUED 637 PM CDT FRI AUG 3 2007/ UPDATE... QUICK UPDATE TO UP POPS IN DVL REGION AS NEW STORMS FIRING WEST OF AREA NR MINOT TO WILLISTON AND CONTINUED STORMS SITTING OVER WELLS COUNTY. STILL HARD TO GET A HANDLE ON HOW TSTMS IN NRN ND WILL EVOLVE OVERNIGHT BUT DEFINITE SFC BOUNDARY LOCATED THRU CNTRL ND FROM NR SIDNEY MT TO NORTH OF BISMARCK TO NR FARGO WITH GOOD CONVERGENCE RIGHT ALONG BOUNDARY NOTED ATTM FROM NR SIDNEY MT TO NR GARRISON ND WHERE NEW TSTMS FIRING. WOULD EXPECT THIS ACTIVITY TO MOVE NORTH AND NORTHEAST TONIGHT BUT AS 850 MB JET FOCUSES SOUTHWARD INTO SD UNSURE IT ACTIVITY WILL WEAKEN A LOT OVERNIGHT OR CONTINUE. KEPT CHC POPS EASTWARD INTO GRAND FORKS AREA AND OVER SE ND/WCNTRL MN MAINLY FOR THE OVERNIGHT HOURS AS RUC WOULD STILL SHOW CONTINUED DEVELOP OF ELEVATED COMPLEX IN SOUTH DAKOTA POSSIBLY AFFECTING MY SOUTHERN FCST AREA 06Z-12Z TIME PERIOD. PREV DISCUSSION... /ISSUED 225 PM CDT FRI AUG 3 2007/ SHORT TERM... MAIN CHALLENGE WILL CHANCES FOR CONVECTION THROUGH THE FORECAST...WITH SEVERAL SHORTWAVES EXPECTED TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. A PERSISTENT CLUSTER OF ELEVATED STORMS CONTINUES TO DRIFT EAST IN 850-700MB MOIST ADVECTION AND MODEST INSTABILITY. THIS CLUSTER SHOULD EVENTUALLY WEAKEN AS IT ENCOUNTERS MORE STABILITY FURTHER EAST. MODELS HAVE CONVERGED ON THE GFS SOLUTION FOR A MORE SOUTHERN TRACK FOR THIS NEXT EVENT TONIGHT/SAT...SO WILL FOLLOW THE GFS WHICH HAS BEEN SUPERIOR ALL SUMMER. FOR TONIGHT...EXPECT AN ELEVATED BAND OF THUNDER TO CONTINUE TO MOVE INTO EASTERN ND AND WEAKEN THIS EVENING. THIS IS IN RESPONSE TO 700-850MB WARM/MOIST ADVECTION AND 40KT OF AVAILABLE SHEAR. ANOTHER AREA OF CONVECTION SHOULD DEVELOP IN NORTHEAST SD AND BRUSH SOUTHERN AREAS WITH MAINLY SHOWERS AND THE THREAT FOR SOME THUNDER. ON SAT...THE BULK OF THE CONVECTION WILL SLIDE SOUTH OF THE AREA AS STRONG SHORTWAVE MOVES SOUTHEAST OF THE REGION. RETURN FLOW WILL DEVELOP FOR SAT NIGHT/SUNDAY AHEAD OF THE NEXT SHORTWAVE. BY SUNDAY...ANOTHER CHANCE FOR STORMS IS POSSIBLE MAINLY DURING THE AFTERNOON WITH ZONAL FLOW DEVELOPING. IF THE REGION CAN HEAT OUT INTO THE MID 80S...DEEP LAYERED SHEAR WOULD BE SUFFICIENT FOR THE THREAT FOR A FEW SEVERE STORMS. BY MONDAY...EXPECT ANOTHER SHORTWAVE TO BRING THE THREAT FOR SOME THUNDER...MAINLY LATE IN THE DAY. LONG TERM (TUE-FRI)...MODELS IN GOOD AGREEMENT WITH LARGE SCALE (PLACING THE FA IN ZONAL FLOW). SHOULD BE A PERIOD OF PRECIP ACTIVITY EVERY DAY OR TWO. HOWEVER...GIVEN THIS PATTERN...TIMING/DETAILS WILL REMAIN UNCERTAIN FOR AWHILE. MODELS HINTING AT A STRONGER SIGNAL TOWARD PRECIP MON NIGHT INTO TUE AND WILL GO WITH CURRENT FORECAST OF THUNDER FOR TUE AND DRY FOR WED. BEYOND THAT...NO STRONG SIGNALS ARE APPARENT. WILL GO WITH LOW END POPS (AS PER HPC GUIDANCE) THU-FRI GIVEN INCREASING LOW-LEVEL MOISTURE AND FLOW ALOFT TURNING A BIT MORE SW. TEMPERATURE NEAR TO SLIGHTLY ABOVE NORMAL GIVEN LARGE SCALE PATTERN. AVIATION...TAF SITES SHOULD REMAIN WITH VFR CEILINGS AND VSBY THROUGH THE PERIOD. SYSTEM MOVING ACROSS SOUTH DAKOTA WILL SPREAD LOWER CEILINGS (AROUND 5000 FT) UP TOWARD KFAR WITH SHOWERS POSSIBLE FOR A BRIEF PERIOD AFTER MIDNIGHT. KGFK AND KBJI SHOULD BE ENOUGH NORTH THAT PRECIP WILL NOT BE INCLUDED IN TAF (PROBABILITY TOO LOW). && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ RIDDLE nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 637 PM CDT FRI AUG 3 2007 .UPDATE... QUICK UPDATE TO UP POPS IN DVL REGION AS NEW STORMS FIRING WEST OF AREA NR MINOT TO WILLISTON AND CONTINUED STORMS SITTING OVER WELLS COUNTY. STILL HARD TO GET A HANDLE ON HOW TSTMS IN NRN ND WILL EVOLVE OVERNIGHT BUT DEFINITE SFC BOUNDARY LOCATED THRU CNTRL ND FROM NR SIDNEY MT TO NORTH OF BISMARCK TO NR FARGO WITH GOOD CONVERGENCE RIGHT ALONG BOUNDARY NOTED ATTM FROM NR SIDNEY MT TO NR GARRISON ND WHERE NEW TSTMS FIRING. WOULD EXPECT THIS ACTIVITY TO MOVE NORTH AND NORTHEAST TONIGHT BUT AS 850 MB JET FOCUSES SOUTHWARD INTO SD UNSURE IT ACTIVITY WILL WEAKEN A LOT OVERNIGHT OR CONTINUE. KEPT CHC POPS EASTWARD INTO GRAND FORKS AREA AND OVER SE ND/WCNTRL MN MAINLY FOR THE OVERNIGHT HOURS AS RUC WOULD STILL SHOW CONTINUED DEVELOP OF ELEVATED COMPLEX IN SOUTH DAKOTA POSSIBLY AFFECTING MY SOUTHERN FCST AREA 06Z-12Z TIME PERIOD. && .PREV DISCUSSION... /ISSUED 225 PM CDT FRI AUG 3 2007/ SHORT TERM... MAIN CHALLENGE WILL CHANCES FOR CONVECTION THROUGH THE FORECAST...WITH SEVERAL SHORTWAVES EXPECTED TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. A PERSISTENT CLUSTER OF ELEVATED STORMS CONTINUES TO DRIFT EAST IN 850-700MB MOIST ADVECTION AND MODEST INSTABILITY. THIS CLUSTER SHOULD EVENTUALLY WEAKEN AS IT ENCOUNTERS MORE STABILITY FURTHER EAST. MODELS HAVE CONVERGED ON THE GFS SOLUTION FOR A MORE SOUTHERN TRACK FOR THIS NEXT EVENT TONIGHT/SAT...SO WILL FOLLOW THE GFS WHICH HAS BEEN SUPERIOR ALL SUMMER. FOR TONIGHT...EXPECT AN ELEVATED BAND OF THUNDER TO CONTINUE TO MOVE INTO EASTERN ND AND WEAKEN THIS EVENING. THIS IS IN RESPONSE TO 700-850MB WARM/MOIST ADVECTION AND 40KT OF AVAILABLE SHEAR. ANOTHER AREA OF CONVECTION SHOULD DEVELOP IN NORTHEAST SD AND BRUSH SOUTHERN AREAS WITH MAINLY SHOWERS AND THE THREAT FOR SOME THUNDER. ON SAT...THE BULK OF THE CONVECTION WILL SLIDE SOUTH OF THE AREA AS STRONG SHORTWAVE MOVES SOUTHEAST OF THE REGION. RETURN FLOW WILL DEVELOP FOR SAT NIGHT/SUNDAY AHEAD OF THE NEXT SHORTWAVE. BY SUNDAY...ANOTHER CHANCE FOR STORMS IS POSSIBLE MAINLY DURING THE AFTERNOON WITH ZONAL FLOW DEVELOPING. IF THE REGION CAN HEAT OUT INTO THE MID 80S...DEEP LAYERED SHEAR WOULD BE SUFFICIENT FOR THE THREAT FOR A FEW SEVERE STORMS. BY MONDAY...EXPECT ANOTHER SHORTWAVE TO BRING THE THREAT FOR SOME THUNDER...MAINLY LATE IN THE DAY. LONG TERM (TUE-FRI)...MODELS IN GOOD AGREEMENT WITH LARGE SCALE (PLACING THE FA IN ZONAL FLOW). SHOULD BE A PERIOD OF PRECIP ACTIVITY EVERY DAY OR TWO. HOWEVER...GIVEN THIS PATTERN...TIMING/DETAILS WILL REMAIN UNCERTAIN FOR AWHILE. MODELS HINTING AT A STRONGER SIGNAL TOWARD PRECIP MON NIGHT INTO TUE AND WILL GO WITH CURRENT FORECAST OF THUNDER FOR TUE AND DRY FOR WED. BEYOND THAT...NO STRONG SIGNALS ARE APPARENT. WILL GO WITH LOW END POPS (AS PER HPC GUIDANCE) THU-FRI GIVEN INCREASING LOW-LEVEL MOISTURE AND FLOW ALOFT TURNING A BIT MORE SW. TEMPERATURE NEAR TO SLIGHTLY ABOVE NORMAL GIVEN LARGE SCALE PATTERN. AVIATION...TAF SITES SHOULD REMAIN WITH VFR CEILINGS AND VSBY THROUGH THE PERIOD. SYSTEM MOVING ACROSS SOUTH DAKOTA WILL SPREAD LOWER CEILINGS (AROUND 5000 FT) UP TOWARD KFAR WITH SHOWERS POSSIBLE FOR A BRIEF PERIOD AFTER MIDNIGHT. KGFK AND KBJI SHOULD BE ENOUGH NORTH THAT PRECIP WILL NOT BE INCLUDED IN TAF (PROBABILITY TOO LOW). && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ RIDDLE nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 1035 PM EDT FRI AUG 3 2007 .SYNOPSIS... A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA OVERNIGHT. HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE GREAT LAKES ON SATURDAY. THEN THE FRONT WILL RETURN BACK ACROSS THE REGION ON SUNDAY AS A WARM FRONT. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... WEAK COLD FRONT BISECTING FCST AREA ATTM. ISOLD CONVECTION HAD FIRED ALONG BNDRY WITHIN THE LAST HOUR IN THE WHITEWATER VLY...FROM PREBLE CO EAST INTO GREENE CO. APPEARS THAT SOME LO LVL CONV IS AIDING THE DVLPMNT. OTHERWISE SKIES ARE MSTLY CLR ACRS FCST AREA. HAVE READJUSTED 20 POPS FOR ISOLD TSTMS FOR AREAS ALONG AND SOUTH OF I-70 AND EXTENDED THEM OUT THRU 1-2 AM. 00Z RUC INDCG LO LVL CONV WILL WEAKEN AS FRONT CONTINUES TO SLIDE TO THE SOUTH...WITH ANY REMAINING CONVECTION DYING OUT. MVFR HZ/BR WILL BE CONFINED TO SRN FCST AREA WHERE SFC DEWPTS WILL REMAIN HIGHER. MUCH DRIER AIRMASS NORTH OF BNDRY (EVIDENCED BY DEWPTS IN M/U50S IN NW OHIO) SHOULD MAKE FOR A PLEASANT NIGHT. REST OF FCST LOOKED GOOD. ZONE AND GRID UPDATES OUT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... HIGH PRESSURE WILL MOVE ACROSS THE NORTHERN GREAT LAKES ON SATURDAY. NOT MUCH COOLING BEHIND THE FRONT WITH TEMPERATURES ONLY FORECAST TO BE A COUPLE OF DEGREES LOWER THAN TODAYS HIGHS. THEREFORE...HAVE TRENDED HIGHS CLOSER TO WARMER MAV GUID NUMBERS. BOUNDARY WILL BEGIN TO LIFT BACK NORTH AND EAST LATE SATURDAY NIGHT. EXPECT ELEVATED THUNDERSTORMS TO DEVELOP INTO THE WEST AT NOSE OF THE LO LEVEL JET. WEST CENTRAL OHIO IS IN THE MOST FAVORABLE POSITION AND HAVE CHC POPS THERE WITH SLIGHT CHC ACRS THE SW. AT THIS TIME HAVE KEPT THE SE DRY ON SAT NIGHT. AGAIN PREFER LOWS A LTL WARMER THAN GUID. && .LONG TERM /SUNDAY THROUGH FRIDAY/... UPPER RIDGE IS PROGGED TO REMAIN ENTRENCHED ACROSS MOST OF THE CONUS. THIS WILL ALLOW HOT WEATHER TO PERSIST. EXPECT SCATTERED THUNDERSTORMS TO DEVELOP SUNDAY IN THE VICINITY OF A DEVELOPING WARM FRONT. A DRY PERIOD WILL FOLLOW MONDAY AND TUESDAY AFTER THE FRONT LIFTS NORTH. LOW PRESSURE WILL TRAIL A SLOW MOVING COLD FRONT LYING PARALLEL TO THE UPPER FLOW WEDNESDAY THROUGH FRIDAY...WHICH WARRANTS LOW CHANCE POPS FOR THUNDERSTORMS. EXPECT AFTERNOON TEMPERATURES IN THE 90S EACH DAY. THOUGH 1000-850 MB THICKNESS STILL SUGGESTS MID TO UPPER 90S...STAYED CONSERVATIVE AND KEPT CLOSE TO HPC GUIDANCE IN LOW TO MID 90S. WITH THE HEAT AND INCREASING HUMIDITY BUILDING IN NEXT WEEK...HAVE A MENTION OF POTENTIAL HEAT INDICES OF 100 TO 105 DEGREES IN HWO NEXT MON AND TUE. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... COLD FRONT SHWNG UP NICELY ON VIS SAT THIS EVNG...ROUGHLY LOCATED FROM NEAR KMFD W/SW TO NEAR KMIE AND NORTH OF KIND. ISOLD -TSRA CONTINUE TO DRIFT SE ALONG BNDRY. AN OUTSIDE CHANCE AT SOME PCPN WILL EXIST FOR THE NEXT FEW HOURS AT KDAY/KCMH/KLCK UNTIL THE FRONT PUSHES SOUTH OF THESE TERMINALS BY LATE EVNG...AND HAVE MAINTAINED CB WORDING FOR MUCH OF THE EVENING. FURTHER SOUTH...ISOLD -TSRA HAVE DVLPD OFF TO SE OF KCVG/KLUK/KILN AND WILL NOT IMPACT THESE TERMINALS. MUCH DRIER AIRMASS IN WAKE OF FRNTL BNDRY WILL ADVECT INTO NRN FCST AREA AFT MIDNIGHT... RESULTING IN MSTLY CLR SKIES AND LGT WINDS. FURTHER SOUTH...SCT MID LVL CLOUDS WILL LIKELY PERSIST THRU THE NIGHT. MUCH OF THE HZ HAS MIXED OUT ACRS SRN FCST AREA AS SLIGHTLY DRIER AIR HAS MIXED DOWN FROM THE MID LVLS. EXPECT MVFR HZ/BR TO REDVLP LATER TONIGHT WITH POSSIBILITY OF SOME BRIEF IFR CONDITIONS AT KLUK/KILN. CI WILL DRIFT INTO REGION ON SAT AHEAD OF WARM FRONT APPCHG FROM THE MID MISSISSIPPI VLY. WILL SEE GOOD DEAL OF SUNSHINE ONCE AGAIN BUT CI WILL INCREASE AND THICKEN FROM THE WEST BY LATE AFTN/ERLY EVNG. WITH SLIGHTLY DRIER AIRMASS IN PLACE AS SFC HI PRES TRAVERSES GRT LKS...DO NOT EXPECT AS MUCH IN WAY OF HZ DURING DAY SAT. OUTLOOK...SCATTERED THUNDERSTORMS ARE POSSIBLE SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ NEAR TERM...RYAN SHORT TERM...AR LONG TERM...CONIGLIO AVIATION...RYAN oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1005 PM EDT FRI AUG 3 2007 .SYNOPSIS... UPPER LEVEL RIDGE STRENGTHENS ACROSS THE DEEP SOUTH AND BUILDS OVER THE REGION INTO NEXT WEEK. AN AREA OF LOW SURFACE PRESSURE ALONG THE GULF IS EXPECTED TO MOVE NE TO THE CAROLINA COAST BY SUN...BUT REMAIN SOUTH OF THE FORECAST AREA. && .NEAR TERM /THROUGH SATURDAY/... THE LATEST RUC HAS AN H5 SHORT WAVE BISECTING THE FA. THIS PLACES THE MOUNTAINS AND FOOTHILLS IN NVA...WHICH SHOULD INHIBIT ANY CONVECTION THE REST OF THE NIGHT. NOT MUCH IS HAPPENING AHEAD OF THE WAVE EITHER...SO I/VE LOWERED ALL POPS TO 10 PERCENT OR LESS. I DECREASED SKY COVER IN THE GRIDS AS SKIES HAVE CLEARED FOR THE MOST PART...AND THE CI ASSOCIATED WITH THE OLD FRONTAL BAND TO OUR SOUTH HAS MADE LITTLE IF ANY PROGRESS TO THE NORTH. OTHERWISE VERY FEW CHANGES MADE TO THE GRIDS. GFS AND NAM BOTH KEEP THE STALLED BOUNDARY...AND THE WAVE TRACKING ALONG IT...S OF THE FORECAST AREA SAT. FCST BUFKIT SOUNDINGS SHOW WEAK MID LEVEL INVERSION BUT NOT ENOUGH TO CAP CONVECTION OVER MTNS. KEPT SLIGHT CHANCE AFTN-EVE POPS OVER MTNS WITH RESIDUAL MOISTURE... AFTN HEATING AND CAPES OVER 1000 J/KG. UPPER RIDGE CONTINUES BUILDING AND INCREASING THICKNESS OVER AREA. TEMPS SHOULD ONCE AGAIN WARM INTO THE LOW TO MID 90S WITH UPPER 70S AND 80S IN THE MTNS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... H5 RIDGE WILL BECOME A MORE DOMINATE FEATURE OVER THE SOUTHERN APPALACHIANS SUN AND MON. COVERAGE WITHIN THE CWA WILL REMAIN QUITE LOW ON SUNDAY DUE TO A SIGNIFICANT INVERSION AROUND H6...LIKELY LIMITING CAPES TO AROUND 500 J/KG. SREF/MOS POPS SUPPORT ONLY RIDGE TOP CHCS WITH LITTLE TO NO COVERAGE EAST OF THE HIGHER TERRAIN. WARM LLVL THICKNESSES AND FAIR INSOLATION SHOULD RESULT IN SUN MAX TEMPS 3-7 DEGREES ABOVE NORMAL. HEIGHTS WILL REMAIN SLIGHTLY NW...POSSIBLY LEADING TO AN MCS PASSING OVER NRN NC/VIRGINA SUN EVENING...NORTH OF THE CWA. THE RIDGE WILL CONTINUE TO BUILD INTO MONDAY. REMNANT NOCTURNAL DEBRIS CLOUDS...WARM LLVL THICKNESS...AND WEAK DOWNSLOPE FLOW MAY RESULT IN HIGH TEMPS A DEGREE OR TWO WARMER THAN SUN. USING A BLEND OF MAINLY GMOS AND MEX...I EXPECT TEMPS TO PUSH WELL INTO THE MID 90S EAST AND AROUND 90 IN THE MTN VALLEYS. THE TRIPLE DIGIT RECORD HIGHS FOR KGSP AND KCLT FOR THE 6TH OF AUGUST WILL NOT BE THREATENED. HOWEVER...THE RECORD AT KAVL IS 92 SET BACK IN 2002...THE CURRENT FORECAST IS 90. DWPTS SHOULD MIX DURING THE AFTERNOON TO KEEP HEAT INDEX VALUES WITHIN A 3 DEGREE SPREAD FROM THE ACTUAL TEMPERATURE. SHRA/TSRA COVERAGE MON AFTERNOON AND EVENING SHOULD BE A LITTLE HIGHER OVER THE MTNS THAN ON SUNDAY. A WEAKER INVERSION...QUICKER STORM MOTIONS...AND SLIGHTLY GREATER INSTABILITY SHOULD SUPPORT SCT COVERAGE OVER THE HIGHER RIDGES. ISO CONVECTION CAN BE EXPECTED WITHIN THE ADJACENT FOOTHILL COUNTIES...WITH LITTLE TO NO COVERAGE FURTHER EAST. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... CENTER OF A STRONG UPPER LEVEL HIGH LOCATED OVER THE SOUTHEAST GRADUALLY SHIFTS EASTWARD TOWARD THE CAROLINAS FROM TUES THROUGH THE END OF THE WEEK. A FEW S/W TROFS MOVE QUICKLY EASTWARD WELL NORTH OF THE REGION DURING THE PERIOD...WITH GENERAL SUBSIDENCE IN PLACE ACROSS THE FA. ONLY SURFACE FEATURE OF NOTE IS A FRONTAL BOUNDARY FEATURED BY THE 06Z GFS THAT REMAINS STATIONARY ACROSS THE UPPER MIDWEST AND WASHES OUT BY THE END OF THE WEEK. WITH SUBSIDENCE IN PLACE...AND FRONTAL BOUNDARY STAYING WELL NORTH OF THE REGION...HOT AND DRY FORECAST APPEARS QUITE REASONABLE. INSTABILITY DOES INCREASE A BIT EACH AFTERNOON THROUGHOUT THE PERIOD...BUT ONLY SLGHT CHC POPS ARE FEATURED MAINLY ACROSS THE MOUNTAINS AND FOOTHILLS AS WARM MID LEVEL TEMPS ARE EXPECTED TO SUPPRESS ANY WIDESPREAD CONVECTION. ABOVE NORMAL TEMPS EXPECTED TO CONTINUE THROUGH EARLY PART OF THE WEEKEND. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... ANOTHER NIGHT WITH MVFR FOG AND HAZE EXPECTED AT A FEW SITES. AT KAVL THERE WAS A PROLONGED PERIOD OF VERY LOW CIGS AND LOW VSBYS LAST NIGHT. THAT WAS A LITTLE SURPRISING. SEEING AS THE AIRPORT HAD HALF AN INCH OF RAIN TODAY...THEY SHOULD GO DOWN AGAIN TONIGHT...AND I HAVE SEVERAL HOURS OF LIFR CIGS AND IFR VSBYS WITH EVEN WORSE CONDITIONS IN A TEMP GROUP. WINDS TONIGHT WILL BE LIGHT...BUT GENERALLY OUT OF THE SOUTH. AS A WEAK LOW MOVES ALONG THE SE COAST...THERE ARE SOME DIFFERENCES IN MODEL WIND DIRECTIONS TMRW. THE GFS TAKES THE FLOW NE ACROSS THE FA. I THINK THIS IS OVERDONE AND THAT THE LEE TROUGH WILL HAVE MORE INFLUENCE ON THE MASS FIELDS. THEREFORE I KEEP THE WINDS OUT OF THE SOUTH. EXPECT ISOLATED TSTMS AGAIN TMRW...ESPECIALLY IN THE MOUNTAINS. AVIATION OUTLOOK...OTHER THAN EARLY MORNING FOG AND ISOLD AFTN-EVE SHWRS/TSTMS...MAINLY MTNS...VFR CONDITIONS EXPECTED INTO THE MIDDLE OF NEXT WEEK. A WAVE OF LOW PRESSURE IN THE NORTHEAST GULF WILL HAVE TO BE WATCHED BUT LATEST FCST TRENDS KEEP MOST MOISTURE WITH THIS SYSTEM S AND E OF AREA THROUGH THE WEEKEND. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...AIR QUALITY ACTION DAY FROM 6 AM TO 9 PM EDT SATURDAY FOR NCZ036-057-069>072-082. SC...AIR QUALITY ACTION DAY FROM 6 AM TO 9 PM EDT SATURDAY FOR SCZ001>008-010>013-019. && $$ SYNOPSIS...RB NEAR TERM...MCAVOY/RB SHORT TERM...NED LONG TERM...BSH AVIATION...MCAVOY/RB sc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ABERDEEN SD 1101 AM CDT FRI AUG 3 2007 .UPDATE... MADE A FEW ADJUSTMENTS TO THE GRIDS/ZONES THIS MORNING TO UP POPS OVER THE WESTERN CWA. FOR NOW HAVE NOT ADJUSTED TEMPS...BUT MAY NEED TO IF CLOUDS HOLD IN LONGER THAN EXPECTED. OTHERWISE LATEST MODEL RUN OF THE NAM DID NOT INTRODUCE ANY SURPRISES. && .PREV DISCUSSION... .SHORT TERM...TODAY THROUGH 12Z SUNDAY. BIGGEST CHALLENGE IN THE NEAR TERM DEALS WITH IMPENDING PCPN EVENT AND TIMING. MODELS REMAIN IN GOOD AGREEMENT WITH NEXT 5H WAVE TRAVERSING OVER THE TOP OF THE MID-CONUS RIDGE...HELPING TO FLATTEN FEATURE. WATER VAP PIX SHOW FEATURE JUST NOW COMING INTO WRN WY WITH INCREASING HIGH LEVEL CLOUDINESS PRECEDING FEATURE. REGIONAL 88D MOSIAC SHOWS AREA OF -SHRA/EMBEDDED -TSRA MOVING INTO FAR SW SD WHERE AREA OF BEST WAA STILL EXISTS. BOTH NAM AND GFS SHOW INCREASING 7H THETA-E FORCING SETTING UP THROUGH DAY...BUT BEST 85H THETA-E FORCING WAITS UNTIL LATER IN THE AFTN. MODELS SHOW PCPN DEVELOPING ACROSS THE WRN CWA A BIT LATER THAN INHERITED WX GRIDS HAD...WITH THE 06Z RUC WAITING UNTIL NEARLY 18Z BEFORE BRINGING PCPN INTO FAR WRN COUNTIES. HAVE SLOWED DOWN ONSET OF PCPN 3 TO 6 HOURS FOR MOST AREAS. ANOTHER CONCERN IS MOISTURE. MODELS ARE SHOWING MOISTURE RETURNING VERY QUICKLY TO AREA...AND CURRENTLY HAVE MID TO UPPER 60S DWPTS LOCATED ACROSS PARTS OF WRN NEB. GIVEN STRONG SOUTHERLY FETCH THAT SETS UP LATER TODAY...ADVECTING THESE HIGHER DWPTS INTO THE CWA MAKES SENSE. ALSO NOTICED THAT BY 00Z SATURDAY BOTH NAM AND GFS BRING 2+ INCHES PWATS INTO AREA. NAM 310K LAYERS SHOWS SPEC HUMIDITY OF 12 G/KG WITH THE GFS 10 TO 12 G/KG MOISTURE. BY 09Z SATURDAY...BUFKIT SHOWS 2.28" PWATS FOR KABR. HAVE CONTINUED MENTION OF LIKELY TSRA AND ADDED MENTION OF HVY RAIN AS WELL. 50+ KT 85H JET SETS UP TONIGHT HELPING TO SUSTAIN CONVECTION THAT DEVELOPS. ENVISION ISOLD CELLS DEVELOPING LATER THIS AFTERNOON...WITH MCS DEVELOPMENT LATE AFTERNOON...TREKING ACROSS NRN 1/2 OF SD THROUGH EARLY MORNING HOURS. LINGERING 7H/85H THETA-E FORCING...KEEPS TSRA CHANCES ACROSS THE EAST DURING THE MORNING SATURDAY. DOWNGLIDE FINALLY SETS IN BY 18Z SATURDAY 305-310K LAYERS...HELPING TO END THE RAINFALL CHANCES. CLOUDS LINGERING ACROSS THE EAST SATURDAY WILL KEEP TEMPS FROM REACHING TRUE POTENTIAL...AND LOWERED THEM A BIT MORE THAN WHAT WAS INHERITED. DRY WEATHER LOOKS GOOD FOR SATURDAY NIGHT WITH NEUTRAL/CAA REGIME SETTING IN AND LAYERS DRYING OUT. .LONG TERM...SUNDAY THROUGH THURSDAY MAIN FORECAST CHALLENGE IN THE EXTENDED PERIOD IS PINPOINTING BEST CHANCES FOR PRECIP AS WEAK WAVES MOVE THROUGH IN FAST UPPER LEVEL ZONAL FLOW. MODELS STILL SHOWING FLAT UPPER RIDGE STARTING OFF THE PERIOD ON SUNDAY...BUT THEN QUICKLY TURNS TO ZONAL FLOW WITH A TROUGH ON THE WEST COAST. MODELS SHOWING NUMEROUS WEAK WAVES MOVING EAST WITHIN FLOW WITH WEAK SURFACE BOUNDARIES DANCING AROUND THE UPPER MIDWEST. WILL BE HARD TO NAIL DOWN BEST CHANCES FOR PRECIP SO HAVE STAYED CLOSE TO PREVIOUS WX/POP GRIDS THROUGH THE EXTENDED. DID ADD A SLIGHT CHANCE ACROSS CENTRAL SD SUNDAY AFTERNOON AS NAM AND GFS SHOWING WEAK FRONTAL BOUNDARY SAGGING SOUTH INTO THE AREA BY AFTERNOON...AND GENERATING PRECIP ALONG IT. TEMPERATURES WILL BE ON THE WARM TO HOT SIDE WITH 80S AND 90S COMMON ACROSS THE AREA. WILL MORE THAN LIKELY ALSO SEE AN INCREASE IN HUMIDITY BY SUNDAY AS 60S DEWPOINTS CREEP BACK INTO THE AREA. WITH THE MOIST AIRMASS IN PLACE...COMBINED WITH THE WEAK WAVES/SFC BOUNDARIES MOVING THROUGH THE AREA...WILL PROBABLY SEE A HANDFUL OF PRECIP EPISODES SCATTERED ABOUT THE DAKOTAS. BUT AS MENTIONED PREVIOUSLY...VERY HARD TO NAIL DOWN SPECIFICS IN TIMING/LOCATIONS AT THIS TIME. && .AVIATION... FOR THE MOST PART...VFR CONDITIONS ARE EXPECTED OVER CENTRAL/NORTHEAST SOUTH DAKOTA THROUGH TODAY. HOWEVER...CIGS AND VSBYS WITH SHOWERS/THUNDERSTORMS AROUND THE KMBG/KPIR REGIONS COULD FALL INTO THE MVFR RANGE FOR SHORT PERIODS OF TIME. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...TDK SHORT TERM...HINTZ LONG TERM...TMT AVIATION...TDK sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 317 AM CDT FRI AUG 3 2007 .SHORT TERM...TODAY THROUGH 12Z SUNDAY. BIGGEST CHALLENGE IN THE NEAR TERM DEALS WITH IMPENDING PCPN EVENT AND TIMING. MODELS REMAIN IN GOOD AGREEMENT WITH NEXT 5H WAVE TRAVERSING OVER THE TOP OF THE MID-CONUS RIDGE...HELPING TO FLATTEN FEATURE. WATER VAP PIX SHOW FEATURE JUST NOW COMING INTO WRN WY WITH INCREASING HIGH LEVEL CLOUDINESS PRECEDING FEATURE. REGIONAL 88D MOSIAC SHOWS AREA OF -SHRA/EMBEDDED -TSRA MOVING INTO FAR SW SD WHERE AREA OF BEST WAA STILL EXISTS. BOTH NAM AND GFS SHOW INCREASING 7H THETA-E FORCING SETTING UP THROUGH DAY...BUT BEST 85H THETA-E FORCING WAITS UNTIL LATER IN THE AFTN. MODELS SHOW PCPN DEVELOPING ACROSS THE WRN CWA A BIT LATER THAN INHERITED WX GRIDS HAD...WITH THE 06Z RUC WAITING UNTIL NEARLY 18Z BEFORE BRINGING PCPN INTO FAR WRN COUNTIES. HAVE SLOWED DOWN ONSET OF PCPN 3 TO 6 HOURS FOR MOST AREAS. ANOTHER CONCERN IS MOISTURE. MODELS ARE SHOWING MOISTURE RETURNING VERY QUICKLY TO AREA...AND CURRENTLY HAVE MID TO UPPER 60S DWPTS LOCATED ACROSS PARTS OF WRN NEB. GIVEN STRONG SOUTHERLY FETCH THAT SETS UP LATER TODAY...ADVECTING THESE HIGHER DWPTS INTO THE CWA MAKES SENSE. ALSO NOTICED THAT BY 00Z SATURDAY BOTH NAM AND GFS BRING 2+ INCHES PWATS INTO AREA. NAM 310K LAYERS SHOWS SPEC HUMIDITY OF 12 G/KG WITH THE GFS 10 TO 12 G/KG MOISTURE. BY 09Z SATURDAY...BUFKIT SHOWS 2.28" PWATS FOR KABR. HAVE CONTINUED MENTION OF LIKELY TSRA AND ADDED MENTION OF HVY RAIN AS WELL. 50+ KT 85H JET SETS UP TONIGHT HELPING TO SUSTAIN CONVECTION THAT DEVELOPS. ENVISION ISOLD CELLS DEVELOPING LATER THIS AFTERNOON...WITH MCS DEVELOPMENT LATE AFTERNOON...TREKING ACROSS NRN 1/2 OF SD THROUGH EARLY MORNING HOURS. LINGERING 7H/85H THETA-E FORCING...KEEPS TSRA CHANCES ACROSS THE EAST DURING THE MORNING SATURDAY. DOWNGLIDE FINALLY SETS IN BY 18Z SATURDAY 305-310K LAYERS...HELPING TO END THE RAINFALL CHANCES. CLOUDS LINGERING ACROSS THE EAST SATURDAY WILL KEEP TEMPS FROM REACHING TRUE POTENTIAL...AND LOWERED THEM A BIT MORE THAN WHAT WAS INHERITED. DRY WEATHER LOOKS GOOD FOR SATURDAY NIGHT WITH NEUTRAL/CAA REGIME SETTING IN AND LAYERS DRYING OUT. .LONG TERM...SUNDAY THROUGH THURSDAY MAIN FORECAST CHALLENGE IN THE EXTENDED PERIOD IS PINPOINTING BEST CHANCES FOR PRECIP AS WEAK WAVES MOVE THROUGH IN FAST UPPER LEVEL ZONAL FLOW. MODELS STILL SHOWING FLAT UPPER RIDGE STARTING OFF THE PERIOD ON SUNDAY...BUT THEN QUICKLY TURNS TO ZONAL FLOW WITH A TROUGH ON THE WEST COAST. MODELS SHOWING NUMEROUS WEAK WAVES MOVING EAST WITHIN FLOW WITH WEAK SURFACE BOUNDARIES DANCING AROUND THE UPPER MIDWEST. WILL BE HARD TO NAIL DOWN BEST CHANCES FOR PRECIP SO HAVE STAYED CLOSE TO PREVIOUS WX/POP GRIDS THROUGH THE EXTENDED. DID ADD A SLIGHT CHANCE ACROSS CENTRAL SD SUNDAY AFTERNOON AS NAM AND GFS SHOWING WEAK FRONTAL BOUNDARY SAGGING SOUTH INTO THE AREA BY AFTERNOON...AND GENERATING PRECIP ALONG IT. TEMPERATURES WILL BE ON THE WARM TO HOT SIDE WITH 80S AND 90S COMMON ACROSS THE AREA. WILL MORE THAN LIKELY ALSO SEE AN INCREASE IN HUMIDITY BY SUNDAY AS 60S DEWPOINTS CREEP BACK INTO THE AREA. WITH THE MOIST AIRMASS IN PLACE...COMBINED WITH THE WEAK WAVES/SFC BOUNDARIES MOVING THROUGH THE AREA...WILL PROBABLY SEE A HANDFUL OF PRECIP EPISODES SCATTERED ABOUT THE DAKOTAS. BUT AS MENTIONED PREVIOUSLY...VERY HARD TO NAIL DOWN SPECIFICS IN TIMING/LOCATIONS AT THIS TIME. && .AVIATION... VFR CONDITIONS EXPECTED THROUGH LATE AFTERNOON ACROSS ALL TAF/TWEB LOCATIONS. EXPECT SCT-BKN CIGS GENERALLY ABOVE 10000 FT. AS AN AREA OF LOW PRESSURE MOVES INTO WESTERN SOUTH DAKOTA THIS AFTERNOON...-TSRA/TSRAS ARE POSSIBLE NEAR THE KMBG/KPIR TERMINALS DURING THE EVENING HOURS. CONDITIONS WILL MORE THAN LIKELY DROP INTO MVFR WITHIN ANY TSRAS. THIS TSRA ACTIVITY IS FORECAST TO MOVE EAST ACROSS SOUTH DAKOTA OVERNIGHT. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...HINTZ LONG TERM...TMT AVIATION...TMT sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 1116 AM CDT THU AUG 2 2007 .UPDATE... ADJUSTED GRIDS SLIGHTLY TO BETTER REFLECT CLOUD COVER OVER SW CWA. BUMPED UP HIGH TEMPERATURES A HAIR OVER WESTERN CWA TO ACCOUNT FOR WAA THIS AFTERNOON...AS WELL AS OVER EASTERN CWA TO BETTER ACCOUNT FOR DAYTIME HEATING...LOW DEWPOINTS...AND RELATIVELY LIGHT WINDS. OTHERWISE...NO REAL CHANGES MADE AS HIGH PRESSURE CURRENTLY SITS JUST NORTH OF CWA. THE ISOLATED SHOWERS FROM EARLIER THIS MORNING IN WESTERN STANLEY COUNTY HAVE CEASED...LEAVING BEHIND SOME SCATTERED MID CLOUDS. && .PREV DISCUSSION... .SHORT TERM...TODAY THROUGH FRIDAY NIGHT SURFACE HIGH PRESSURE BEGINNING TO BUILD INTO THE REGION EARLY THIS MORNING WITH MUCH DRIER AND COOLER AIR THAN WHATS BEEN SEEN THE PAST SEVERAL DAYS. DEWPOINTS RANGE FROM THE MID 40S TO MID 50S ACROSS THE CWA WITH TEMPS IN THE 50S. FARTHER WEST OVER WESTERN SD...CLOUDS ARE ON THE INCREASE AND ISO SHOWERS HAVE FORMED OVER THE PAST COUPLE HOURS AS DECENT THETA E ADVECTION FROM 850-700 MB SPREADS ACROSS THE AREA. RUC/HI RES NAM SHOWING THIS PERSISTING OVER THE NEXT SEVERAL HOURS. ACTIVITY MAY BE ABLE TO SNEAK INTO PORTIONS OF CENTRAL SD BUT WILL REMAIN VERY ISOLATED. HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH FRIDAY MORNING ALLOWING FOR FAIR SKIES AND DRY CONDITIONS...ALONG WITH FAIRLY LIGHT WINDS. BY FRIDAY MORNING THE HIGH IS CENTERED JUST TO OUR EAST...WITH SOUTHERLY FLOW AND A 25-30 KT LLJ ACROSS WESTERN SD. THERE IS A LITTLE BIT OF THETA E ADVECTION GOING ON ALSO...SO HAVE KEPT SLIGHT CHANCE POPS IN PLACE FOR FRIDAY MORNING. ALTHOUGH...WILL PROBABLY HAVE TO WAIT UNTIL LATE FRIDAY AFTERNOON AND INTO FRIDAY NIGHT BEFORE PRECIP CHANCES INCREASE IN RESPONSE TO A STRONGER WAVE WHICH WILL MOVE EAST ACROSS THE AREA. STILL SOME PLACEMENT ISSUES WITH THE WAVE AND WHERE BEST CHANCES FOR PRECIP WILL BE. GFS FAVORS A MORE SOUTHERLY TRACK WITH BEST CHANCES ACROSS SOUTHERN SD...WHILE THE NAM IS FARTHER NORTH. SREF MEMBERS TEND TO FAVOR A MORE SOUTHERLY TRACK ALSO. GENERALLY LEFT WX/POP GRIDS AS IS FOR FRIDAY NIGHT. .LONG TERM...SATURDAY THROUGH WEDNESDAY MAIN FORECAST CHALLENGE IN THE EXTENDED CONTINUES TO CENTER AROUND PRECIPITATION CHANCES. AN UPPER LEVEL HIGH WILL BE OVER THE SOUTHERN PLAINS SATURDAY...THEN SHIFTS JUST SLIGHTLY EASTWARD TO THE SOUTHEASTERN UNITED STATES SUNDAY AND MONDAY. THE FLOW OVER THE NORTHERN PLAINS WILL BE NEARLY ZONAL...WITH A SERIES OF SHORTWAVES TRACKING EASTWARD IN THE FLOW. A BROAD TROUGH OF SURFACE LOW PRESSURE WILL REMAIN OVER THE PLAINS DURING THIS TIME...KEEPING THE REGION IN A FAIRLY UNSETTLED PATTERN. A STRONGER SHORTWAVE TROUGH WILL TRACK ACROSS THE AREA ON TUESDAY...THEN HIGH PRESSURE FINALLY SLIDES OVER THE AREA ON WEDNESDAY. THE SHORTWAVES ARE NOT REAL EASY TO TIME...BUT THE MODELS ARE IN SOME AGREEMENT THAT LATE SATURDAY NIGHT AND SUNDAY WILL BE DRY. OTHERWISE...WILL KEEP A SMALL POP GOING THROUGH TUESDAY NIGHT...AND WILL KEEP WEDNESDAY DRY UNDER THE INFLUENCE OF THE HIGH MOVING IN. LOWERED TEMPERATURES A BIT ON SATURDAY AS SIGNIFICANT CLOUD COVER AND POSSIBLE PRECIPITATION WILL AFFECT THE AREA. WILL THEN SEE TEMPS RIGHT AROUND NORMAL SUNDAY AND MONDAY...THEN JUST A HINT OF A WARM UP BY WEDNESDAY UNDER MORE SUNSHINE. && .AVIATION... VFR CONDITIONS ARE EXPECTED THROUGH TONIGHT WITH JUST SCT MID AND HIGH CLOUDS AOA 10K FEET OVER THE CENTRAL PART OF SOUTH DAKOTA. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...GIONTA SHORT TERM...TMT LONG TERM...PARKIN AVIATION...DORN sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 336 AM CDT THU AUG 2 2007 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT SURFACE HIGH PRESSURE BEGINNING TO BUILD INTO THE REGION EARLY THIS MORNING WITH MUCH DRIER AND COOLER AIR THAN WHATS BEEN SEEN THE PAST SEVERAL DAYS. DEWPOINTS RANGE FROM THE MID 40S TO MID 50S ACROSS THE CWA WITH TEMPS IN THE 50S. FARTHER WEST OVER WESTERN SD...CLOUDS ARE ON THE INCREASE AND ISO SHOWERS HAVE FORMED OVER THE PAST COUPLE HOURS AS DECENT THETA E ADVECTION FROM 850-700 MB SPREADS ACROSS THE AREA. RUC/HI RES NAM SHOWING THIS PERSISTING OVER THE NEXT SEVERAL HOURS. ACTIVITY MAY BE ABLE TO SNEAK INTO PORTIONS OF CENTRAL SD BUT WILL REMAIN VERY ISOLATED. HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH FRIDAY MORNING ALLOWING FOR FAIR SKIES AND DRY CONDITIONS...ALONG WITH FAIRLY LIGHT WINDS. BY FRIDAY MORNING THE HIGH IS CENTERED JUST TO OUR EAST...WITH SOUTHERLY FLOW AND A 25-30 KT LLJ ACROSS WESTERN SD. THERE IS A LITTLE BIT OF THETA E ADVECTION GOING ON ALSO...SO HAVE KEPT SLIGHT CHANCE POPS IN PLACE FOR FRIDAY MORNING. ALTHOUGH...WILL PROBABLY HAVE TO WAIT UNTIL LATE FRIDAY AFTERNOON AND INTO FRIDAY NIGHT BEFORE PRECIP CHANCES INCREASE IN RESPONSE TO A STRONGER WAVE WHICH WILL MOVE EAST ACROSS THE AREA. STILL SOME PLACEMENT ISSUES WITH THE WAVE AND WHERE BEST CHANCES FOR PRECIP WILL BE. GFS FAVORS A MORE SOUTHERLY TRACK WITH BEST CHANCES ACROSS SOUTHERN SD...WHILE THE NAM IS FARTHER NORTH. SREF MEMBERS TEND TO FAVOR A MORE SOUTHERLY TRACK ALSO. GENERALLY LEFT WX/POP GRIDS AS IS FOR FRIDAY NIGHT. .LONG TERM...SATURDAY THROUGH WEDNESDAY MAIN FORECAST CHALLENGE IN THE EXTENDED CONTINUES TO CENTER AROUND PRECIPITATION CHANCES. AN UPPER LEVEL HIGH WILL BE OVER THE SOUTHERN PLAINS SATURDAY...THEN SHIFTS JUST SLIGHTLY EASTWARD TO THE SOUTHEASTERN UNITED STATES SUNDAY AND MONDAY. THE FLOW OVER THE NORTHERN PLAINS WILL BE NEARLY ZONAL...WITH A SERIES OF SHORTWAVES TRACKING EASTWARD IN THE FLOW. A BROAD TROUGH OF SURFACE LOW PRESSURE WILL REMAIN OVER THE PLAINS DURING THIS TIME...KEEPING THE REGION IN A FAIRLY UNSETTLED PATTERN. A STRONGER SHORTWAVE TROUGH WILL TRACK ACROSS THE AREA ON TUESDAY...THEN HIGH PRESSURE FINALLY SLIDES OVER THE AREA ON WEDNESDAY. THE SHORTWAVES ARE NOT REAL EASY TO TIME...BUT THE MODELS ARE IN SOME AGREEMENT THAT LATE SATURDAY NIGHT AND SUNDAY WILL BE DRY. OTHERWISE...WILL KEEP A SMALL POP GOING THROUGH TUESDAY NIGHT...AND WILL KEEP WEDNESDAY DRY UNDER THE INFLUENCE OF THE HIGH MOVING IN. LOWERED TEMPERATURES A BIT ON SATURDAY AS SIGNIFICANT CLOUD COVER AND POSSIBLE PRECIPITATION WILL AFFECT THE AREA. WILL THEN SEE TEMPS RIGHT AROUND NORMAL SUNDAY AND MONDAY...THEN JUST A HINT OF A WARM UP BY WEDNESDAY UNDER MORE SUNSHINE. && .AVIATION... VFR CONDITIONS WILL BE IN PLACE ACROSS THE AREA TODAY. A SCT-BKN DECK OF CLOUDS ABOVE 7000 ARE LIKELY WEST OF THE MISSOURI RIVER THROUGH 14Z...WITH THE REST OF THE REGION SEEING MOSTLY CLEAR SKIES. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...TMT LONG TERM...PARKIN AVIATION...PARKIN sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 855 PM CDT FRI AUG 3 2007 .UPDATE...WATER VAPOR IMAGERY AND 600 MB RUC/NAM STREAMLINES INDICATE THAT THE UPPER TROUGH IS APPROACHING THE COAST FROM THE EAST. ANTICIPATE THAT CONVECTION WL DEVELOP OVERNIGHT AS THE UPPER TROUGH AXIS MOVES WEST. WL RETAIN THE CURRENT FCST OF CONVECTION DEVELOPING AFT 06Z SAT OVR THE COASTAL WATERS...WITH ACTIVITY APPROACHING THE COAST BY 12Z SAT. CURRENT SFC MIN TEMP FCST REASONABLE BASED IN PART ON CURRENT SFC DEW POINTS. BASED ON EXPECTED SYNOPTIC SCALE MSLP PATTERN OVERNIGHT...WIND/SEAS WL REMAIN WELL BELOW SCEC CRITERIA...ALTHOUGH BRIEF GUSTY CONDITIONS PSBL NEAR CONVECTION. NO SIGNIFICANT CHANGES TO THE FCST WARRANTED. && .AVIATION...PATCHY MVFR VSBYS IN MIST ARE EXPECTED BETWEEN 06Z-14Z WITH LOCALIZED IFR VSBYS/CIGS IN FOG FROM 10Z-13Z. ISOLATED TO SCATTERED CONVECTION WITH MVFR CIGS/VSBYS WILL DEVELOP AROUND 10Z ALONG THE COAST AND SPREAD WESTWARD TO THE RIO GRANDE PLAINS AROUND 20Z. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 75 92 76 94 78 / 10 30 10 20 20 VICTORIA 75 93 76 93 77 / 20 30 10 20 20 LAREDO 78 97 79 101 80 / 20 20 10 10 10 ALICE 74 95 75 98 77 / 20 30 10 20 10 ROCKPORT 79 91 80 92 81 / 20 30 10 20 20 COTULLA 74 96 75 99 76 / 20 20 10 10 10 KINGSVILLE 75 94 77 97 79 / 20 30 10 20 10 NAVY CORPUS 80 91 80 93 81 / 20 30 10 20 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...SHORT TERM BB/85...AVIATION tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 715 PM CDT THU AUG 2 2007 .UPDATE... CONVECTION DYING RAPIDLY THIS EVENING AS EVIDENCED BY MAJOR REDUCTION IN RADAR RETURNS AND RAPID CLOUD TOP WARMING VIA IR LOOP. LATEST RUNS OF NAM/RUC SUGGEST LINGERING ACTIVITY ON THE CAPROCK THIS EVENING AND OVERNIGHT WITH NAM SUGGESTING SOME ADDITIONAL DEVELOPMENT OVER WESTERN SOUTH PLAINS TOWARD SUNRISE FRIDAY AHEAD OF NEXT WEAK IMPULSE MOVING WEST OVER THE REGION. OF COURSE...VERY MOIST AIRMASS WILL REMAIN IN PLACE AND CONVECTION COULD STILL FORM WHEREVER ENOUGH FORCING OCCURS. WILL GO AHEAD AT LET FFW RUN UNTIL 8 PM...BUT DOUBT EXTENSION WILL BE NECESSARY AT THIS POINT. WILL LOWER POPS OFF THE CAPROCK THROUGH THE REMAINDER OF THE EVENING IF CONVECTION CONTINUES TO DISSIPATE AS EXPECTED. CONTINUES TO APPEAR THAT LOW CLOUDS AND FOG WILL DEVELOP LATE TONIGHT ACROSS THE REGION GIVEN RECENT RAINS...PARTICULARLY ACROSS THE SOUTHEAST PANHANDLE NEAR CHILDRESS AND OTHER AREAS THAT HAVE EXPERIENCED THE HEAVIEST RAINFALL THE LAST COUPLE OF DAYS. && .PREV DISCUSSION... /ISSUED 346 PM CDT THU AUG 2 2007/ SHORT TERM... INTERESTING BUT NOT HIGHLY UNUSUAL OCCURRENCE OF LANDSPOUTS AND FUNNELS ACROSS PORTIONS OF THE SOUTH PLAINS THIS AFTERNOON. BREAKS IN CLOUDS AROUND LUBBOCK AREA CREATED ENVIRONMENT FAVORABLE FOR BRIEF SPINUPS WITH STEEP LOW LEVEL RATES...MOIST BOUNDARY LAYER AND LOW LEVEL VORTICITY GENERATION VIA DIFFERENTIAL HEATING BOUNDARIES. REPORTS QUICKLY WANED ONCE DEVELOPING SHOWERS CREATED DOWNDRAFTS AND AIRMASS STABILIZED SOME WITH RECURRENCE OF THICK CLOUD COVER. ONGOING HEAVY RAIN EVENT ACROSS WESTERN ROLLING PLAINS WILL BE THE STORY FOR THE REMAINDER OF THE EVENING AS IT PROPAGATES WWD. REPORTS CONFIRM REMOTE SENSING ESTIMATES OF RAINFALL RATES APPROACHING THREE INCHES PER HOUR FROM CELL MERGERS AND HEAVIEST CORES. WITH CONVECTION HEAVILY DRIVEN BY MESOSCALE OUTFLOW AND CELL INTERACTIONS WOULD EXPECT TO SEE FURTHER LOCALIZED FLASH FLOODING PROBLEMS ESPECIALLY AS CORES MOVE OVER MORE HEAVILY POPULATED AREAS OF SOUTH PLAINS AND ROLLING PLAINS. AS A RESULT HAVE CONTEMPLATED SHORT FUSE FLASH FLOOD WATCH FOR CENTRAL AND SOUTHERN AREAS. WITH BACK EDGE OF PRECIPITATION STILL IN SW OK...ENDING TIME OF PRECIP MAY NEED TO BE ADJUSTED LATER AS WELL. 12Z NAM AND 18Z RUN SUPPORTED IDEA OF STRONG DEEP LAYER SHEAR MOVING INTO AREA THIS EVENING WHICH SHOULD AID IN KEEPING COMPLEX GOING INTO THE NIGHT. SHRTWV ACROSS RED RIVER OFFERING ADDITIONAL SUPPORT FOR STORMS WILL ROTATE W OVERNIGHT BENEATH BUILDING RIDGE ACROSS CENTRAL PLAINS. DAYTIME HEATING AND RESIDUAL MOISTURE WILL COMBINE WITH THIS FEATURE TO PRODUCE CHANCE OF PRECIP AGAIN ACROSS SW CORNER ON FRI. WITH HEIGHTS BUILDING EXPECT COVERAGE TO BE LIMITED BUT STILL COULD SEE TERRAIN DRIVEN STORMS ALONG THE CAPROCK AS WELL LATE IN THE AFTERNOON. WITH DECREASING CLOUDS IN WAKE OF SYSTEM EXPECT TEMPS TO ONCE AGAIN CLIMB INTO THE LOWER 90S OFF THE CAPROCK WITH A MILD START TO THE DAY. LONG TERM... 12Z MODEL SUITE AND GFS ENSEMBLES SUPPORT THE ONGOING FORECAST WITH LITTLE CHANGES. AS THE LAST UPPER-LEVEL DISTURBANCES MOVE WEST INTO NM AND ARIZ...UPPER LEVEL RIDGE WILL EXPAND TO THE EAST OVER TX/OKLA FOR THE WEEKEND...AND THEN CONTINUE TO MIGRATE EASTWARD AND SETTLE IN ACROSS THE LOWER MS VALLEY THROUGH THE EARLY TO MIDDLE PART OF NEXT WEEK. WE MAY SEE A FEW LINGERING SHOWERS ACROSS THE WESTERN ZONES FRI NIGHT AND THEN IT APPEARS THAT THERE WILL BE A CHANCE FOR SOME LOW CLOUDS AND FOG TO DEVELOP SAT MORN AS THE MID-UPR LVLS OF THE ATMOSPHERE BEGIN TO DRY OUT. THIS POSSIBILITY MAY HINGE ON HOW WIDESPREAD HEAVY RAINFALL IS ACROSS THE AREA THIS EVENING TO PRODUCE THE WET SOILS. OTHERWISE...THE WELL ADVERTISED WARMING TREND IS STILL ANTICIPATED. BUT WE DO EXPECT THIS TO TREND SLOWER THAN MOS GUIDANCE INDICATED. BY MONDAY...AS WEST TEXAS BECOMES SITUATED MORE ON THE WESTERN PERIPHERY OF THE UPPER RIDGE AND A FAIRLY HIGH AMPLITUDE TROUGH MOVES INTO THE WESTERN U.S....HEIGHTS WILL ACTUALLY BEGIN TO DECREASE. THE RESULTING DEEP SW FLOW AND A SOMEWHAT DRIER AIRMASS SHOULD KEEP TEMPS QUITE WARM THOUGH. THIS PATTERN WITH MORE WIND FLOW NORMAL TO THE SPINE OF THE ROCKIES WILL ALSO RESULT IN SOME LEE-TROUGHING ACROSS THE HIGH PLAINS AND EXTENDING SOUTH ALONG THE TX/NM BORDER. AS INDICATED PREVIOUSLY...CONVERGENCE IN THE TROUGH MAY BE SUFFICIENT FOR ISOLD TSTM DEVELOPMENT DURING ANY AFTN OR EVE...BUT CONFIDENCE IS TOO LOW TO ADD TO GRIDS ATTM. IN ADDITION...THE GFS INDICATES THAT A WEAK SHTWV TROUGH MOVING OUT OF THE ROCKIES AND THROUGH THE CENTRAL PLAINS ON TUE MAY DRIVE A COLD FRONT SOUTH...POSSIBLY INTO THE PANHANDLES TUE NIGHT. ALTHOUGH EXPECT IT TO STALL OUR NORTH OF THE CWA...WILL HAVE TO WATCH FOR ANY PUSH FROM OUTFLOWS. AVIATION... COULD SEE BRIEF STRATUS/FOG DEVELOPMENT IN WAKE OF CONVECTION ACROSS SOUTHERN PNHDL FRI MORNING. DEGREE OF CLEARING OVERNIGHT IN THIS AREA WILL FIGURE INTO HOW DENSE THE FOG GETS BUT IFR VSBYS NOT OUT OF THE QUESTION. CONFIDENCE LOW ENOUGH TO ATTM TO ONLY HINT AT IN TAFS. EXPECT LOW CIGS NEAR 1K FEET BY 12Z FRI AT KLBB WITH MVFR CIGS POSSIBLY PERSISTING INTO THE LATE MORNING. TSTM CHCS WILL BE DIMINISHING ON FRI HOWEVER ISOLATED EARLY MORNING SHOWERS IN VCNTY KLBB NOT OUT OF THE QUESTION. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 65 87 66 90 66 / 40 20 10 10 10 TULIA 67 89 67 91 67 / 40 20 10 10 10 PLAINVIEW 67 88 67 90 68 / 40 20 10 10 10 LEVELLAND 66 87 67 91 68 / 40 30 10 10 10 LUBBOCK 67 89 70 91 70 / 40 30 10 10 10 BROWNFIELD 68 87 68 91 69 / 50 30 20 10 10 CHILDRESS 71 92 72 95 71 / 30 10 10 10 10 SPUR 71 90 70 92 71 / 40 20 10 10 10 ASPERMONT 71 91 72 94 72 / 40 20 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 8 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: TXZ029>032-035>038-041>044. && $$ 17/13 tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 1234 PM CDT THU AUG 2 2007 .AVIATION... 18Z TAF ISSUANCE MAIN CONVECTIVE SHOW IS OFF TO THE WEST OF THE TRACON RIGHT NOW...BUT AFTERNOON HEATING OVER THE EAST WILL ALLOW FOR WIDELY SCATTERED CONVECTION TO DEVELOP DURING THE NEXT COUPLE HOURS. WILL SHOW VCTS/TEMPO TSRA FOR METROPLEX SITES THROUGH THE AFTERNOON HOURS. ACTIVITY SHOULD DIMINISH BY 23Z-0Z AND QUIET/VFR CONDITIONS WILL PREVAIL THROUGH THE OVERNIGHT HOURS. WILL SHOW A TEMPO FOR MVFR BR/HZ AT ALL SITES WITH LIGHT EASTERLY FLOW CONTINUING. AIRMASS WILL DRY OUT DURING THE NEXT DAY...SO WILL HAVE NO CONVECTION TOMORROW MORNING IN TAFS...BUT ENOUGH LOW LEVEL MOISTURE WILL REMAIN FOR SOME MVFR CUMULUS IN THE LATE MORNING HOURS. TR.92 && .UPDATE... 1000 AM MORNING SOUNDING SHOWS CONVECTIVE TEMP OF 88 DEGREES...WELL WITHIN REACH BY EARLY AFTERNOON IN MOST AREAS EXCEPT FOR WHERE RAIN IS CURRENTLY FALLING. HAVE UPPED POPS IN THE NORTHEAST TO CHANCE FROM SLIGHT CHANCE BECAUSE OF INSTABILITY. OTHERWISE...PACKAGE REMAINS SIMILAR. 84 .AVIATION... 710 AM SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE MOSTLY SOUTHWEST OF THE METROPLEX TAF SITES THIS MORNING. CEILINGS HAVE BEEN A HEADACHE...AS THEY HAVE GONE FROM SCT-BKN 004-010 OVERNIGHT. HAVE JUST PLACED SCT006 WITH A TEMPO 5SM BR BKN006 FOR THE 12-15Z PERIOD. WITH SHOWERS/THUNDERSTORMS IN THE WACO AREA HAVE KEPT TEMPO SHRA AND VCTS THROUGH 14Z. SCATTERED SHOWERS AND THUNDERSTORMS MAY REDEVELOP THIS AFTERNOON SO HAVE PLACED CB IN THE TAFS FOR THE 17-01Z PERIOD. && .PREV DISCUSSION... /ISSUED 616 AM CDT THU AUG 2 2007/ UPDATE...HAVE MADE SOME MINOR ADJUSTMENTS TO POPS THIS MORNING BASED ON LATEST RADAR TRENDS. ACTIVITY IS INCREASING TO THE WEST SO HAVE RAISED POPS TO 50 PERCENT FOR THE MORNING. ALSO MADE SOME MINOR TWEAKS TO HOURLY GRIDS. PREV DISCUSSION... /ISSUED 320 AM CDT THU AUG 2 2007/ LOOKS LIKE ONE MORE DAY OF ABOVE NORMAL RAIN CHANCES ACROSS NORTH TEXAS...THEN MORE SUMMER LIKE CONDITIONS BUILD IN WITH MINIMAL RAIN CHANCES AND TEMPERATURES NEAR 100 DEGREES. SCATTERED SHOWERS AND THUNDERSTORMS ALREADY DEVELOPING AGAIN TO THE NORTHWEST OF THE METROPLEX AND WELL TO THE SOUTHEAST. OLD SYNOPTIC BOUNDARY IS BARELY DISCERNIBLE...BUT BEST CONVERGENT LOW LEVEL WINDS AND TIGHTER THETA-E GRADIENT RESIDES ACROSS THE FAR WESTERN CWA. CURRENT ACTIVITY TO THE NORTHWEST IS LIKELY BEING AIDED BY A WEAK S/W MOVING SOUTH OUT OF OKLAHOMA AS INDICATED BY THE 7Z RUC WIND ANALYSIS. THIS WILL CONTINUE TO MOVE SOUTH THROUGH THE DAY. NEW CONVECTION WILL AGAIN BE DRIVEN BY RESIDUAL OUTFLOW AND ADDITIONAL BOUNDARY INTERACTION...SO PRECIP CHANCES ARE HIGH...BUT NOT EVERYONE WILL SEE RAIN...AS HAS BEEN THE CASE FOR THE LAST SEVERAL DAYS. DO EXPECT HIGHEST CHANCES TO BE SLIGHTLY FARTHER SOUTH AND WEST TODAY THAN THEY WERE YESTERDAY. PWS STILL IN EXCESS OF 2 INCHES AND STORM MOTIONS AROUND 5 KTS WILL MEAN LOCALLY HEAVY RAINFALL AND ISOLATED FLASH FLOODING WILL STILL BE POSSIBLE. TEMPS AGAIN WILL BE TRICKY WITH THE PRECIP/CLOUDS BUT LAST FEW DAYS HAVE SEEN TEMPS IN THE LO/MID 90S...SO SEE NO OVERWHELMING REASON TO DEVIATE DESPITE MOS HIGHS IN THE UPPER 80S/NEAR 90. UPPER RIDGING BUILDS IN STRONGER ON FRIDAY WITH PWS COMING DOWN SO DONT EXPECT MORE THAN ISOLATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. OTHER THAN AN ISOLATED SEABREEZE THUNDERSTORM MAKING IT INTO THE SOUTHEAST ON SATURDAY...EXPECT A DRY FORECAST THROUGH THE WEEKEND AND INTO NEXT WEEK. 1000-500MB THICKNESSES CONTINUE TO RISE INTO NEXT WEEK...SO EXPECT HIGH TEMPS TO BE AOA 100 DEGREES MANY AREAS BY MONDAY WITH HEAT INDEX VALUES AROUND 105. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 76 97 76 98 / 40 20 20 10 10 WACO, TX 94 74 97 74 98 / 50 20 20 10 10 PARIS, TX 93 74 94 72 95 / 20 10 10 10 10 DENTON, TX 93 74 95 73 96 / 30 20 10 10 10 MCKINNEY, TX 93 73 95 73 96 / 30 20 10 10 10 DALLAS, TX 94 77 96 77 97 / 40 20 20 10 10 TERRELL, TX 93 74 96 74 96 / 40 20 20 10 10 CORSICANA, TX 93 74 95 74 96 / 50 20 20 10 10 TEMPLE, TX 93 74 94 74 95 / 50 20 20 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 58/91/58 tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 1000 AM CDT THU AUG 2 2007 .UPDATE... 1000 AM MORNING SOUNDING SHOWS CONVECTIVE TEMP OF 88 DEGREES...WELL WITHIN REACH BY EARLY AFTERNOON IN MOST AREAS EXCEPT FOR WHERE RAIN IS CURRENTLY FALLING. HAVE UPPED POPS IN THE NORTHEAST TO CHANCE FROM SLIGHT CHANCE BECAUSE OF INSTABILITY. OTHERWISE...PACKAGE REMAINS SIMILAR. 84 .AVIATION... 710 AM SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE MOSTLY SOUTHWEST OF THE METROPLEX TAF SITES THIS MORNING. CEILINGS HAVE BEEN A HEADACHE...AS THEY HAVE GONE FROM SCT-BKN 004-010 OVERNIGHT. HAVE JUST PLACED SCT006 WITH A TEMPO 5SM BR BKN006 FOR THE 12-15Z PERIOD. WITH SHOWERS/THUNDERSTORMS IN THE WACO AREA HAVE KEPT TEMPO SHRA AND VCTS THROUGH 14Z. SCATTERED SHOWERS AND THUNDERSTORMS MAY REDEVELOP THIS AFTERNOON SO HAVE PLACED CB IN THE TAFS FOR THE 17-01Z PERIOD. && .PREV DISCUSSION... /ISSUED 616 AM CDT THU AUG 2 2007/ UPDATE...HAVE MADE SOME MINOR ADJUSTMENTS TO POPS THIS MORNING BASED ON LATEST RADAR TRENDS. ACTIVITY IS INCREASING TO THE WEST SO HAVE RAISED POPS TO 50 PERCENT FOR THE MORNING. ALSO MADE SOME MINOR TWEAKS TO HOURLY GRIDS. PREV DISCUSSION... /ISSUED 320 AM CDT THU AUG 2 2007/ LOOKS LIKE ONE MORE DAY OF ABOVE NORMAL RAIN CHANCES ACROSS NORTH TEXAS...THEN MORE SUMMER LIKE CONDITIONS BUILD IN WITH MINIMAL RAIN CHANCES AND TEMPERATURES NEAR 100 DEGREES. SCATTERED SHOWERS AND THUNDERSTORMS ALREADY DEVELOPING AGAIN TO THE NORTHWEST OF THE METROPLEX AND WELL TO THE SOUTHEAST. OLD SYNOPTIC BOUNDARY IS BARELY DISCERNIBLE...BUT BEST CONVERGENT LOW LEVEL WINDS AND TIGHTER THETA-E GRADIENT RESIDES ACROSS THE FAR WESTERN CWA. CURRENT ACTIVITY TO THE NORTHWEST IS LIKELY BEING AIDED BY A WEAK S/W MOVING SOUTH OUT OF OKLAHOMA AS INDICATED BY THE 7Z RUC WIND ANALYSIS. THIS WILL CONTINUE TO MOVE SOUTH THROUGH THE DAY. NEW CONVECTION WILL AGAIN BE DRIVEN BY RESIDUAL OUTFLOW AND ADDITIONAL BOUNDARY INTERACTION...SO PRECIP CHANCES ARE HIGH...BUT NOT EVERYONE WILL SEE RAIN...AS HAS BEEN THE CASE FOR THE LAST SEVERAL DAYS. DO EXPECT HIGHEST CHANCES TO BE SLIGHTLY FARTHER SOUTH AND WEST TODAY THAN THEY WERE YESTERDAY. PWS STILL IN EXCESS OF 2 INCHES AND STORM MOTIONS AROUND 5 KTS WILL MEAN LOCALLY HEAVY RAINFALL AND ISOLATED FLASH FLOODING WILL STILL BE POSSIBLE. TEMPS AGAIN WILL BE TRICKY WITH THE PRECIP/CLOUDS BUT LAST FEW DAYS HAVE SEEN TEMPS IN THE LO/MID 90S...SO SEE NO OVERWHELMING REASON TO DEVIATE DESPITE MOS HIGHS IN THE UPPER 80S/NEAR 90. UPPER RIDGING BUILDS IN STRONGER ON FRIDAY WITH PWS COMING DOWN SO DONT EXPECT MORE THAN ISOLATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. OTHER THAN AN ISOLATED SEABREEZE THUNDERSTORM MAKING IT INTO THE SOUTHEAST ON SATURDAY...EXPECT A DRY FORECAST THROUGH THE WEEKEND AND INTO NEXT WEEK. 1000-500MB THICKNESSES CONTINUE TO RISE INTO NEXT WEEK...SO EXPECT HIGH TEMPS TO BE AOA 100 DEGREES MANY AREAS BY MONDAY WITH HEAT INDEX VALUES AROUND 105. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 76 97 76 98 / 40 20 20 10 10 WACO, TX 94 74 97 74 98 / 50 20 20 10 10 PARIS, TX 93 74 94 72 95 / 20 10 10 10 10 DENTON, TX 93 74 95 73 96 / 30 20 10 10 10 MCKINNEY, TX 93 73 95 73 96 / 30 20 10 10 10 DALLAS, TX 94 77 96 77 97 / 40 20 20 10 10 TERRELL, TX 93 74 96 74 96 / 40 20 20 10 10 CORSICANA, TX 93 74 95 74 96 / 50 20 20 10 10 TEMPLE, TX 93 74 94 74 95 / 50 20 20 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 58/91/58 tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 710 AM CDT THU AUG 2 2007 .AVIATION... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE MOSTLY SOUTHWEST OF THE METROPLEX TAF SITES THIS MORNING. CEILINGS HAVE BEEN A HEADACHE...AS THEY HAVE GONE FROM SCT-BKN 004-010 OVERNIGHT. HAVE JUST PLACED SCT006 WITH A TEMPO 5SM BR BKN006 FOR THE 12-15Z PERIOD. WITH SHOWERS/THUNDERSTORMS IN THE WACO AREA HAVE KEPT TEMPO SHRA AND VCTS THROUGH 14Z. SCATTERED SHOWERS AND THUNDERSTORMS MAY REDEVELOP THIS AFTERNOON SO HAVE PLACED CB IN THE TAFS FOR THE 17-01Z PERIOD. && .PREV DISCUSSION... /ISSUED 616 AM CDT THU AUG 2 2007/ UPDATE...HAVE MADE SOME MINOR ADJUSTMENTS TO POPS THIS MORNING BASED ON LATEST RADAR TRENDS. ACTIVITY IS INCREASING TO THE WEST SO HAVE RAISED POPS TO 50 PERCENT FOR THE MORNING. ALSO MADE SOME MINOR TWEAKS TO HOURLY GRIDS. PREV DISCUSSION... /ISSUED 320 AM CDT THU AUG 2 2007/ LOOKS LIKE ONE MORE DAY OF ABOVE NORMAL RAIN CHANCES ACROSS NORTH TEXAS...THEN MORE SUMMER LIKE CONDITIONS BUILD IN WITH MINIMAL RAIN CHANCES AND TEMPERATURES NEAR 100 DEGREES. SCATTERED SHOWERS AND THUNDERSTORMS ALREADY DEVELOPING AGAIN TO THE NORTHWEST OF THE METROPLEX AND WELL TO THE SOUTHEAST. OLD SYNOPTIC BOUNDARY IS BARELY DISCERNIBLE...BUT BEST CONVERGENT LOW LEVEL WINDS AND TIGHTER THETA-E GRADIENT RESIDES ACROSS THE FAR WESTERN CWA. CURRENT ACTIVITY TO THE NORTHWEST IS LIKELY BEING AIDED BY A WEAK S/W MOVING SOUTH OUT OF OKLAHOMA AS INDICATED BY THE 7Z RUC WIND ANALYSIS. THIS WILL CONTINUE TO MOVE SOUTH THROUGH THE DAY. NEW CONVECTION WILL AGAIN BE DRIVEN BY RESIDUAL OUTFLOW AND ADDITIONAL BOUNDARY INTERACTION...SO PRECIP CHANCES ARE HIGH...BUT NOT EVERYONE WILL SEE RAIN...AS HAS BEEN THE CASE FOR THE LAST SEVERAL DAYS. DO EXPECT HIGHEST CHANCES TO BE SLIGHTLY FARTHER SOUTH AND WEST TODAY THAN THEY WERE YESTERDAY. PWS STILL IN EXCESS OF 2 INCHES AND STORM MOTIONS AROUND 5 KTS WILL MEAN LOCALLY HEAVY RAINFALL AND ISOLATED FLASH FLOODING WILL STILL BE POSSIBLE. TEMPS AGAIN WILL BE TRICKY WITH THE PRECIP/CLOUDS BUT LAST FEW DAYS HAVE SEEN TEMPS IN THE LO/MID 90S...SO SEE NO OVERWHELMING REASON TO DEVIATE DESPITE MOS HIGHS IN THE UPPER 80S/NEAR 90. UPPER RIDGING BUILDS IN STRONGER ON FRIDAY WITH PWS COMING DOWN SO DONT EXPECT MORE THAN ISOLATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. OTHER THAN AN ISOLATED SEABREEZE THUNDERSTORM MAKING IT INTO THE SOUTHEAST ON SATURDAY...EXPECT A DRY FORECAST THROUGH THE WEEKEND AND INTO NEXT WEEK. 1000-500MB THICKNESSES CONTINUE TO RISE INTO NEXT WEEK...SO EXPECT HIGH TEMPS TO BE AOA 100 DEGREES MANY AREAS BY MONDAY WITH HEAT INDEX VALUES AROUND 105. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 76 97 76 98 / 40 20 20 10 10 WACO, TX 94 74 97 74 98 / 50 20 20 10 10 PARIS, TX 93 74 94 72 95 / 20 10 10 10 10 DENTON, TX 93 74 95 73 96 / 30 20 10 10 10 MCKINNEY, TX 93 73 95 73 96 / 30 20 10 10 10 DALLAS, TX 94 77 96 77 97 / 40 20 20 10 10 TERRELL, TX 93 74 96 74 96 / 40 20 20 10 10 CORSICANA, TX 93 74 95 74 96 / 50 20 20 10 10 TEMPLE, TX 93 74 94 74 95 / 50 20 20 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 58/91/58 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FORT WORTH TX 616 AM CDT THU AUG 2 2007 .UPDATE...HAVE MADE SOME MINOR ADJUSTMENTS TO POPS THIS MORNING BASED ON LATEST RADAR TRENDS. ACTIVITY IS INCREASING TO THE WEST SO HAVE RAISED POPS TO 50 PERCENT FOR THE MORNING. ALSO MADE SOME MINOR TWEAKS TO HOURLY GRIDS. && .PREV DISCUSSION... /ISSUED 320 AM CDT THU AUG 2 2007/ LOOKS LIKE ONE MORE DAY OF ABOVE NORMAL RAIN CHANCES ACROSS NORTH TEXAS...THEN MORE SUMMER LIKE CONDITIONS BUILD IN WITH MINIMAL RAIN CHANCES AND TEMPERATURES NEAR 100 DEGREES. SCATTERED SHOWERS AND THUNDERSTORMS ALREADY DEVELOPING AGAIN TO THE NORTHWEST OF THE METROPLEX AND WELL TO THE SOUTHEAST. OLD SYNOPTIC BOUNDARY IS BARELY DISCERNIBLE...BUT BEST CONVERGENT LOW LEVEL WINDS AND TIGHTER THETA-E GRADIENT RESIDES ACROSS THE FAR WESTERN CWA. CURRENT ACTIVITY TO THE NORTHWEST IS LIKELY BEING AIDED BY A WEAK S/W MOVING SOUTH OUT OF OKLAHOMA AS INDICATED BY THE 7Z RUC WIND ANALYSIS. THIS WILL CONTINUE TO MOVE SOUTH THROUGH THE DAY. NEW CONVECTION WILL AGAIN BE DRIVEN BY RESIDUAL OUTFLOW AND ADDITIONAL BOUNDARY INTERACTION...SO PRECIP CHANCES ARE HIGH...BUT NOT EVERYONE WILL SEE RAIN...AS HAS BEEN THE CASE FOR THE LAST SEVERAL DAYS. DO EXPECT HIGHEST CHANCES TO BE SLIGHTLY FARTHER SOUTH AND WEST TODAY THAN THEY WERE YESTERDAY. PWS STILL IN EXCESS OF 2 INCHES AND STORM MOTIONS AROUND 5 KTS WILL MEAN LOCALLY HEAVY RAINFALL AND ISOLATED FLASH FLOODING WILL STILL BE POSSIBLE. TEMPS AGAIN WILL BE TRICKY WITH THE PRECIP/CLOUDS BUT LAST FEW DAYS HAVE SEEN TEMPS IN THE LO/MID 90S...SO SEE NO OVERWHELMING REASON TO DEVIATE DESPITE MOS HIGHS IN THE UPPER 80S/NEAR 90. UPPER RIDGING BUILDS IN STRONGER ON FRIDAY WITH PWS COMING DOWN SO DONT EXPECT MORE THAN ISOLATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. OTHER THAN AN ISOLATED SEABREEZE THUNDERSTORM MAKING IT INTO THE SOUTHEAST ON SATURDAY...EXPECT A DRY FORECAST THROUGH THE WEEKEND AND INTO NEXT WEEK. 1000-500MB THICKNESSES CONTINUE TO RISE INTO NEXT WEEK...SO EXPECT HIGH TEMPS TO BE AOA 100 DEGREES MANY AREAS BY MONDAY WITH HEAT INDEX VALUES AROUND 105. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 76 97 76 98 / 40 20 20 10 10 WACO, TX 94 74 97 74 98 / 50 20 20 10 10 PARIS, TX 93 74 94 72 95 / 20 10 10 10 10 DENTON, TX 93 74 95 73 96 / 30 20 10 10 10 MCKINNEY, TX 93 73 95 73 96 / 30 20 10 10 10 DALLAS, TX 94 77 96 77 97 / 40 20 20 10 10 TERRELL, TX 93 74 96 74 96 / 40 20 20 10 10 CORSICANA, TX 93 74 95 74 96 / 50 20 20 10 10 TEMPLE, TX 93 74 94 74 95 / 50 20 20 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DUNN tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FORT WORTH TX 320 AM CDT THU AUG 2 2007 .DISCUSSION...LOOKS LIKE ONE MORE DAY OF ABOVE NORMAL RAIN CHANCES ACROSS NORTH TEXAS...THEN MORE SUMMER LIKE CONDITIONS BUILD IN WITH MINIMAL RAIN CHANCES AND TEMPERATURES NEAR 100 DEGREES. SCATTERED SHOWERS AND THUNDERSTORMS ALREADY DEVELOPING AGAIN TO THE NORTHWEST OF THE METROPLEX AND WELL TO THE SOUTHEAST. OLD SYNOPTIC BOUNDARY IS BARELY DISCERNIBLE...BUT BEST CONVERGENT LOW LEVEL WINDS AND TIGHTER THETA-E GRADIENT RESIDES ACROSS THE FAR WESTERN CWA. CURRENT ACTIVITY TO THE NORTHWEST IS LIKELY BEING AIDED BY A WEAK S/W MOVING SOUTH OUT OF OKLAHOMA AS INDICATED BY THE 7Z RUC WIND ANALYSIS. THIS WILL CONTINUE TO MOVE SOUTH THROUGH THE DAY. NEW CONVECTION WILL AGAIN BE DRIVEN BY RESIDUAL OUTFLOW AND ADDITIONAL BOUNDARY INTERACTION...SO PRECIP CHANCES ARE HIGH...BUT NOT EVERYONE WILL SEE RAIN...AS HAS BEEN THE CASE FOR THE LAST SEVERAL DAYS. DO EXPECT HIGHEST CHANCES TO BE SLIGHTLY FARTHER SOUTH AND WEST TODAY THAN THEY WERE YESTERDAY. PWS STILL IN EXCESS OF 2 INCHES AND STORM MOTIONS AROUND 5 KTS WILL MEAN LOCALLY HEAVY RAINFALL AND ISOLATED FLASH FLOODING WILL STILL BE POSSIBLE. TEMPS AGAIN WILL BE TRICKY WITH THE PRECIP/CLOUDS BUT LAST FEW DAYS HAVE SEEN TEMPS IN THE LO/MID 90S...SO SEE NO OVERWHELMING REASON TO DEVIATE DESPITE MOS HIGHS IN THE UPPER 80S/NEAR 90. UPPER RIDGING BUILDS IN STRONGER ON FRIDAY WITH PWS COMING DOWN SO DONT EXPECT MORE THAN ISOLATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. OTHER THAN AN ISOLATED SEABREEZE THUNDERSTORM MAKING IT INTO THE SOUTHEAST ON SATURDAY...EXPECT A DRY FORECAST THROUGH THE WEEKEND AND INTO NEXT WEEK. 1000-500MB THICKNESSES CONTINUE TO RISE INTO NEXT WEEK...SO EXPECT HIGH TEMPS TO BE AOA 100 DEGREES MANY AREAS BY MONDAY WITH HEAT INDEX VALUES AROUND 105. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 95 76 97 76 98 / 40 20 20 10 10 WACO, TX 94 74 97 74 98 / 50 20 20 10 10 PARIS, TX 93 74 94 72 95 / 20 10 10 10 10 DENTON, TX 93 74 95 73 96 / 40 20 10 10 10 MCKINNEY, TX 93 73 95 73 96 / 30 20 10 10 10 DALLAS, TX 94 77 96 77 97 / 40 20 20 10 10 TERRELL, TX 93 74 96 74 96 / 40 20 20 10 10 CORSICANA, TX 93 74 95 74 96 / 50 20 20 10 10 TEMPLE, TX 93 74 94 74 95 / 50 20 20 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DUNN tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 359 AM CDT THU AUG 2 2007 .DISCUSSION...FCST FOCUS IS ON CHANCE OF CONVECTION TODAY AND THEN ON A MORE UNSETTLED PERIOD INTO THE WEEKEND AND EARLY NEXT. WATER VAPOR/RUC SHOWS STRONG UPPER LOW VCNTY SRN HUDSON BAY. THE COMMA TAIL EXTENDS SW ACRS NRN WI. CLEARLY THE BRUNT OF THE UPPER FORCING IS STAYING NORTH OF HERE...FROM LAKE SUPERIOR NEWD...AS EVIDENCED BY WHERE THE CONVECTION HAS BEEN SUSTAINED. THE RUC DOES INDICATE ONLY A WEAK LOBE OF VORTICITY AND THIS IS PROGGD TO COME THROUGH THE CWA LATE THIS MRNG AND ERLY THIS AFTN. MEANWHILE THE LOW LEVEL FORCING...ALBEIT WEAK...IS STILL INDICATED BY SUBTLE WIND SHIFT AT H8 AND THE WEAK SURFACE FRONT. INSTAB AND MOIST AXIS IN PLACE AT THE RIGHT TIME OF THE DAY. GFS AND LOCAL WRF DEVELOPS MORE FOCUSED CONVECTION ACRS THE NRN CWA ASSOC WITH LOW LEVEL FRONTAL CONVERGENCE WITHIN THE MOIST/UNSTBL ENVIRONMENT. SPEAKING OF INSTABILITY...SURFACE BASED CAPES OFF THE NAM BUFFY SOUNDINGS DONT LOOK TOO BAD...RUNNING AROUND 1600 J/KG AND THE DEW POINTS LOOK REASONABLE IN THE MID TO UPPER 60S. SO WHILE NOT MUCH HELP FROM THE UPPER DYNAMICS...THE WEAK LOW LEVEL LIFT AND INSTAB AXIS CERTAINLY SUGGESTS KEEPING GOING POPS. GUID POPS ARE ALL IN THE SINGLE DIGITS BUT WILL PROB ADJUST THESE UP IN LINE WITH GOING GRID FORECAST. FRIDAY STILL LOOKING QUIET WITH WEAK RIDGE OF HIGH PRESSURE SETTLING ACRS WRN GRT LAKES. H8 TEMPS DROP A FEW DEGREES SO SOME RELIEF FROM THE HEAT EXPECTED. FCST GETS MUDDIED HEADING INTO SATURDAY DEALING WITH RETURN FLOW. NAM HAS STRAYED FROM THE GFS SOLUTION AND DEVELOPED A NORTHERN PLAINS LOW WITH MUCH OF THE WAA FOCUSED PCPN NORTHWEST OF HERE ON SATURDAY. MEANWHILE THE GFS HAS REMAINED CONSISTENT WITH MORE OF A CENTRAL PLAINS LOW WITH FRONT DRAPED WELL TO OUR SOUTH. THE ECMWF AND CANADIAN REFLECT A COMPROMISE AND HPC HAS STEERED IN THIS DIRECTION. OVERALL...APPEARS THE HIGH WILL HAVE A LINGERING INFLUENCE INTO SATURDAY WITH THE BEST H8 LOW LEVEL FORCING LARGELY TO THE WEST OF HERE. EVEN THE MORE ROBUST GFS SHOWS H8 MOIST CONVERGENCE INTO ONLY THE SW PART OF THE CWA BY 00Z SUNDAY. SO WHILE KEEPING A CHC IN PLACE FOR SATURDAY WILL TREND THE HIGHER POPS FOR SATURDAY NIGHT. BUT FOR NOW BANKING ON INITIATION TO OUR WEST AND THEN ROLLING IN HERE LATE SATURDAY BUT MORE LIKELY SATURDAY NIGHT. FRONTAL POSITION AND TIMING OF ANY RIPPLES WILL BE THE KEY IN SUNDAY/MONDAY TIME FRAME...FOR NOW WILL KEEP THE WELL COLLABORATED CHCY POP SCENARIO IN PLACE. && 10 .AVIATION...BOUNDARY LAYER WINDS OF 10 TO 20 KNOTS SHOULD OFFSET HIGHER DEWPOINTS AND KEEP SHALLOW GROUND FOG PATCHY THROUGH THE EARLY MORNING...EXCEPT IN THE RVR VALLEYS. VERY WEAK LOW LEVEL CONVERGENCE EXPECTED AS SFC BOUNDARY MOVES THROUGH KMSN AROUND 21Z AND KMKE AROUND 00Z. ENUF INSTABILITY TO RESULT IN ISOLD TO WDLY SCT COVERAGE. WL EITHER GO WITH VCNTY REMARK OR BRIEF 1-2 HR TEMPO PD OF LGT THUNDER. CEILINGS MAY FLIRT WITH MVFR PENDING AMOUNT OF CONVECTION COVERAGE DUE TO HIGH LOW LEVEL RH. && .MKX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 410 AM EDT SAT AUG 4 2007 .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER THE GRT LKS BTWN SLOWLY RETREATING VORTEX IN NRN QUEBEC AND UPR RDG OVER THE PLAINS. SFC HI CENTER IS SITUATED NEARLY OVER THE CWA...AND ASSOCIATED AIRMASS IS PARTICULARLY DRY/STABLE AS SHOWN ON 00Z INL/GRB SDNGS (PWAT/KINX 0.49 INCH/2 AND 0.58 INCH/1 RESPECTIVELY). SO SKIES GENERALLY CLR ATTM. HOWEVER...SOME HI CLDS TO THE E OF AREA OF SHRA/TSRA OVER ND TO THE NE OF H85 WARM FNT/AHEAD OF H5 SHRTWV MOVING TOWARD THE NRN PLAINS ARE SPILLING INTO THE UPR LKS. ANOTHER AREA OF SHRA/TSRA NOTED TO THE S OVER SD/NB. MAIN FCST CONCERNS TDAY ARE RELATED TO FIRE WX. FOCUS FOR TNGT/SUN TURNS TO PCPN CHCS ASSOCIATED WITH H85 WARM FNT NOW IN THE NRN PLAINS. FOR TDAY...LATEST GFS/NAM SHOW CENTER OF HI PRES DRIFTING SLOWLY TO SE ONTARIO BY 00Z SUN. AREA OF LOWEST PWAT BLO 0.75 INCH PROGGED TO LINGER THRU THE DAY OVER THE E HALF. OTRW...00Z NAM F6 H85-7 FGEN FIELD CORRELATES WELL WITH OBSVD AREA OF SHRA/TSRA NOW IN ND. MODEL TENDS TO MOVE THIS FORCING MORE NE INTO NW ONTARIO. SO ALTHOUGH SOME HI CLD WL SPILL INTO THE WRN FA WHERE GUIDANCE SHOWS PWAT INCHING ABV 1 INCH...SKIES SHOULD BE MOSUNNY. MIXING TO H8 ON GFS/NAM FCST SDNGS YIELD HI TEMPS ARND 80-82 AWAY FM LK MODERATION. RETURN SLY FLOW ON THE BACK SIDE OF HI DRIFTING TO THE E WL TRANSPORT A BIT HIER LLVL MSTR INTO THE FA AS COMPARED TO YDAY. BUT SINCE LLVL DRY AIR HAS SPREAD FAIRLY FAR TO THE S...PREFER THE SOMEWHAT DRIER LLVLS OF THE GFS FCST SDNGS...WHICH WOULD SUG DWPTS WL MIX OUT AS LO AS 40 TO 45 AGAIN AWAY FM MODERATING FLOW OFF THE LK. T/TD OF 80/45 WOULD LOWER RH TO JUST BLO 30 PCT...AND T/TD OF 80/40 WOULD YIELD 25 PCT. EVEN IF THE LOWER RH VALUES VERIFY...EXPECTED WINDS APPEAR TO BE TOO LO FOR FIRE WX WATCH/WRNG. WL REISSUE WILDFIRE POTENTIAL STATEMENT TO HIGHLIGHT CONTINUED HIER RISK FOR WILDFIRES. NAM REMAINS THE WETTEST OF THE MODELS FOR TNGT SHOWING AN H85 SW WIND OF 40 KTS RETURNING QUITE A BIT OF LLVL MSTR. NAM QPF ALG THE WI BORDER FCST TO ARPCH 0.35 INCH. GFS IS STILL ONE OF THE DRIER SCENARIOS AND SHOWS NO QPF. CONSIDERING MODELS SHOW MAIN H85 WARM FNT LINGERING TO THE S AND NAM IS TRENDING WEAKER WITH THE IMPULSE/ LOWER WITH THE QPF...SEEMS THE GFS IS PROBABLY ON THE RIGHT TRACK. TEMPTED TO DISCOUNT THE NAM ALTOGETHER...BUT 00Z CNDN SHOWS QPF FARTHER N TO AREA OF SHARP H85-7 FGEN AT 12Z SUN ACRS THE NRN CWA AND MORE CONFLUENT H85 WINDS...ALSO WELL N OF THE SHARPER H85 FNT. RUC13 MODEL ALSO SHOWS PCPN SPREADING FARTHER TO THE N...SIMILAR TO AT LEAST SOME OF THE SREF MEMBERS. WITH H85 WARM FNT SO FAR TO THE S AND ANTECEDENT AIRMASS SO DRY...STILL LIKE THE CONSISTENT GFS FCST DESPITE THE OTHER MODEL SUPPORT FOR A SCENARIO SIMILAR TO THE NAM. HOWEVER...OPTED TO SPREAD LO CHC POPS FARTHER N IN THE 06Z-12Z TIMEFRAME THAN CURRENTLY FCST BASED ON THE ARRAY OF SUPPORT...AND USED CNDN MODEL SHARPER FGEN FCST AS THE LINE SO ADVANCE THE POP. WL END PCPN CHCS W-E ON SUN AS MODELS WHICH SUPPORT PCPN SHOW H85 FLOW VEERING TO MORE W IN THE WAKE OF TROF. SINCE THE GFS/NAM DIVERGE SO MUCH ON THE FCST TNGT...EACH PAINTS A VERY DIFFERENT PICTURE OF WHAT WL HAPPEN ON SUN. NOT SURPRISINGLY...GFS SHOWS A MUCH DRIER LLVL ENVIRONMENT OVER THE E WITH MORE SUNSHINE/DWPTS ARND 50 AT ERY THRU THE DAY. NAM HINTS DWPTS WOULD RISE INTO THE 60S WITH MORE CLD COVER. BOTH MODELS DO SHOW A CONSIDERABLE RISE IN LLVL MSTR OVER THE W IN ADVANCE OF SFC LO TRACKING ACRS CNTRL CNA. TENDED TOWARD THE GFS FCST SCENARIO GIVEN PREFERENCE FOR THE MORE MINIMAL MSTR TRANSPORT TO THE NE TNGT. COLD FROPA FCST SUN NGT ATTENDANT TO SFC LO TRACKING ACRS CNTRL CAN. NAM IS QUITE A BIT STRONGER WITH THIS LO...EXHIBITING A STRONGER WNW FLOW IN ITS WAKE/FASTER COLD FROPA. TENDED TOWARD A COMPROMISE UKMET SCENARIO...WHICH SUGS BNDRY WL REACH NR ERY-MNM AT 12Z MON. SINCE ANY DEEPER MSTR EXITS DURING THE DAY ON SUN WITH SYS RESPONSIBLE FOR PCPN CHCS LATE TNGT/SUN AND FROPA WL BE IN ABSENCE OF ANY DIURNAL HTG...EXPECT THE FROPA WL BE DRY DESPITE SOME FAIRLY STEEP H85-5 LAPSE RATES 7-7.5C/KM. UKMET SHOWS SFC COLD FNT EDGING PAST THE SCNTRL AND ERN COUNTIES EARLY ON MON MRNG AND GIVING WAY TO HI PRES BLDG IN FM ONTARIO. EXPECT TEMPS OVER THE INTERIOR SCNTRL AWAY FM LK SUP MODERATION IN DVLPG NE FLOW TO RISE WELL INTO THE 80S PER MIXING TO H75-8 ON GFS FCST SDNGS AND UKMET H85 TEMP FCST JUST BLO 20C. SINCE PREVIOUS FCST HAD A 30 POP OVER THE ENTIRE FA...MAINTAINED THOSE LO CHC POPS IN THE AFTN OVER THE SCNTRL GIVEN CONSIDERABLE SFC HTG AND POTENTIAL FOR LK BREEZE CNVGC...ESPECIALLY IF SFC COLD FNT HANGS UP JUST TO THE S. GUIDANCE PERSISTS IN SHOWING SFC LO APRCHG THE CNTRL GRT LKS MON NGT/TUE...WITH MOST MODELS TRENDING S OF THE GFS FCST...WHICH MAY BE SUFFERING CONVECTIVE FEEDBACK AND DVLPG LO TOO FAR TO THE N. MAINTAINED GOING CHC POPS DURING THIS TIME. THEN WENT DRY ON WED TO REFLECT RDG BLDG IN THE WAKE OF THIS SHRTWV. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... VFR CONDITIONS IN THE FORM OF SCT MID-HIGH CLOUDS PREVAIL TODAY AS DRY HIGH PRES CONTINUES TO DOMINATE WX. WAVE OF LOW PRES AND A WARM FRONT OVER MN LATE SAT WILL LEAD TO DEVELOPMENT OF SHOWERS AND THUNDERSTORMS TO THE SW OF UPR MI. ANY PCPN WILL STAY OUT OF FORECAST AREA UNTIL AFT 06Z SUN. && .MARINE (FOR 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS ARE EXPECTED TO REMAIN BELOW 20 KT THROUGH THE PERIOD. HOWEVER...THERE ARE TWO PERIODS OF CONCERN WHERE THE WINDS COULD GET CLOSE TO 20 KT. THE FIRST IS LATE TONIGHT INTO SUN ON EASTERN LAKE SUPERIOR...DUE TO THE PRESSURE GRADIENT TIGHTENING BETWEEN A TROUGH ADVANCING EASTWARD ACROSS THE NORTHERN PLAINS AND HIGH PRESSURE MOVING TOWARDS NEW ENGLAND. THE SECOND IS ON ALL OF LAKE SUPERIOR LATE MON NIGHT INTO TUE MORNING AS A RESULT OF A LOW PRESSURE AREA MOVING FROM SOUTH DAKOTA ACROSS CENTRAL LAKE MICHIGAN...TIGHTENING THE PRESSURE GRADIENT BRIEFLY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...KC AVIATION...AJ MARINE...AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 135 AM EDT FRI AUG 4 2007 .SYNOPSIS... WEAK LOW PRESSURE OVER SOUTHEAST GEORGIA AND SOUTH CAROLINA WILL MOVE OFF THE SOUTH CAROLINA COAST TODAY AND MOVE EASTWARD... FURTHER AWAY FROM THE SOUTHEAST U.S. COAST TONIGHT AND SUNDAY. AN UPPER RIDGE WILL BUILD IN FROM THE SOUTHWEST SUNDAY THROUGH TUESDAY...AND BECOME THE DOMINATE WEATHER FEATURE FOR THE REMAINDER OF NEXT WEEK. SOME OF THE HOTTEST TEMPERATURES THIS SUMMER SEASON WILL LIKELY OCCUR NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... DIFFUSE AREA OF LOW PRESSURE IN SW GA IS EXPECTED TO MOVE ENE DURING THE PD. MAIN FCST ISSUE OVERNIGHT IS HOW FAR N INTO THE CWA THIS WILL MANAGE TO SPREAD PRECIP. RUC HAS PREVIOUSLY BEEN OVERFORECASTING THIS TREND BUT IS SEEMINGLY BECOMING BETTER INTIALZIED WITH THE CONVECTION NOW OCCURRING NEAR THE SC/GA BORDER. NEWER RUNS KEEP ALL MEASUREABLE RAIN IN EXTREME SRN ZONES MUCH AS DEPICTED IN CONTINUITY. WILL STILL SHOW SOME SLGHT CHANCE POPS FARTHER N ALONG THE COAST AS THE NAM AND GFS STILL SHOW A RATHER IMPRESSIVE NOCTURNAL CONVECTIVE SIGNAL JUST OFFSHORE...SOME OF WHICH MAY GLANCE THE COAST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... WEAK LOW PRESSURE AND WEAKENING FRONTAL BOUNDARY WILL START OUT THE PERIOD WITH BEST CHANCES OF PCP ALONG THE BOUNDARY ACROSS SOUTHERN PORTIONS OF CWA EXTENDING INTO COASTAL WATERS. KEPT BEST CHC OF PCP ALONG THE COAST FOR TOMORROW. BY SUNDAY...WEAK SFC LOW DRIFTS OFF SHORE AND HEIGHTS BUILDING ALOFT...KEEPING AREA ON BACK END OF MID TO UPPER TROUGH AND LOWER CHC OF PCP. KEPT MAX TEMPS SLIGHTLY COOLER ON SAT WITH MORE CLOUDS AND SHOWERS IN AREA..ESPECIALLY ALONG COASTAL SECTIONS. TEMPS UP INTO THE MID 90S IN MOST PLACES ON SUNDAY WITH SLIGHTLY LOWER TEMPS ALONG THE COAST. && .LONG TERM /MONDAY THROUGH FRIDAY/... 5H RIDGE AND PIEDMONT TROF WILL REMAIN SEMI-PERMANENT FEATURES THROUGH THE LONG TERM PERIOD. SUBSIDENCE UNDER THE RIDGE WILL KEEP TEMPERATURES ABOVE CLIMO AND POPS SLIGHTLY BELOW CLIMO. BOTH GFS/ECMWF SHOWING 850 TEMPS LATE IN THE PERIOD AT OR ABOVE 20C. GUIDANCE SHOWS WEAK SURFACE LOW OFF THE COAST AT THE START OF THE PERIOD BUT FLOW AROUND THE UPPER RIDGE WILL PUSH THIS FEATURE WELL SOUTHEAST OF THE REGION. WARMEST TEMPERATURES WILL BE WEDNESDAY AND THURSDAY WHEN 5H RIDGE IS THE STRONGEST. THESE DAYS WILL ALSO HAVE THE LEAST LIKELY CHANCE OF SEEING PRECIP DEVELOP...EVEN ALONG THE ANTICIPATED SEA BREEZE. && .AVIATION /06Z SATURDAY THROUGH THURSDAY/... THE LOWER SFC DEWPOINTS PROVIDED BY SUBSIDENCE THIS AFTERNOON AND EVENING...WILL LIKELY CURTAIL MUCH OF THE FOG POTENTIAL. AS A RESULT...HAVE ONLY INDICATED TEMPO MVFR CONDITIONS AROUND A 1-2 HR WINDOW CENTERED AT SUNRISE. WITH THE SFC LOW DEPICTED TO MOVE OFF THE SOUTHERN SC COAST AND OFFSHORE TODAY...MYR AND CRE WILL LIKELY BE THE TERMINALS UNDER THE GUN FOR POSSIBLE MVFR CONDITIONS FROM CLOUDS AND WX AFFECTING VSBY. ELSEWHERE...MAINLY VFR CONDITIONS. SFC PRESSURE PATTERN FROM DEPARTING SFC LOW AND THE SEA BREEZE WILL BE THE FEATURES AFFECTING WINDS. ISOLATED CONVECTION SUNDAY AND MONDAY...WITH LITTLE OR NO CONVECTION TUESDAY THROUGH THURSDAY DUE TO A WELL ESTABLISHED UPPER RIDGE AFFECTING THE AREA. && .MARINE... NEAR TERM /THROUGH TONIGHT/... A LITTLE UNCERTAINTY WITH WIND SPEED AND DIRECTION THIS PD STEMMING FROM THE LOW IN SW GA THAT WILL LIFT TO THE ENE. A GENERAL SRLY DIRECTION SHOULD CONTINUE WITH A BACKING FROM SW TO SE POSSIBLE. SPEEDS SHOULD STAY CAPPED AT 15 KTS. SPEEDS HAVE BEEN BUMPED UP A FEW KTS FROM PREV FCST AS KCLX VWP/INCREASED STORM STRUCTURE NEAR SC/GA BORDER AND OCP7 BOUY ALL SUGGEST THAT SOME COASTAL JETTING MAY BE OCCURRING. SHORT TERM /SATURDAY MORNING THROUGH SUNDAY NIGHT/... THE WIND FIELD ACROSS THE WATERS WILL BECOME TRICKY AS WRF CONTINUES TO SHOW ANOTHER WEAK LOW TO DRIFT ACROSS GA INTO SC SATURDAY THROUGH SATURDAY NIGHT. MAINLY REMAIN IN SOUTHERLY FLOW...BUT DEPENDING ON MOVEMENT OF LOW PRESSURE OFF THE COAST ON SATURDAY NIGHT...WILL SEE A PERIOD OF ON SHORE WINDS SAT NIGHT INTO SUNDAY MORNING WITH WINDS INCREASING TO AROUND 15 KTS BUILDING SEAS UP TO AROUND 4 FT IN OFF SHORE WATERS. OTHERWISE SEAS 2 TO 4 FT AND WINDS 10 TO 15 KTS. LONG TERM /SUNDAY THROUGH MONDAY/... SURFACE FLOW WILL REMAIN LIGHT AND FROM THE SOUTH/SOUTHEAST THROUGH THE PERIOD WITH BERMUDA HIGH OFF THE COAST AND PIEDMONT TROF INLAND. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...HOEHLER NEAR TERM...MBB SHORT TERM...RGZ LONG TERM...III AVIATION...HOEHLER nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 430 AM CDT SAT AUG 4 2007 .SHORT TERM... PROGRESSIVE UPPER AIR PATTERN IS FORECAST ACROSS THE NORTHERN US AND SOUTHERN CANADA THROUGH THE PERIOD. UPPER LEVEL RIDGE OVER THE WESTERN SOUTHERN PLAINS SHIFTS OVER THE SOUTHEAST STATES BY 84 HOURS. UPPER LEVEL RIDGE OVER MB/SK WILL MOVE TO THE NEW ENGLAND/SOUTHERN QUEBEC BY SUN NIGHT. EMBEDDED UPPER TROUGH WAS OVER SD WILL MOVE OVER THE EASTERN GREAT LAKES BY SUN NIGHT. WATER VAPOR LOOP INDICATES SOME DRYING OVER WESTERN SD. RUC APPEARS TO HAVE THE BEST HANDLE ON WIND FIELD FROM THE AREA VAD WINDS IN THE NORTHERN PLAINS. MOST SITES HAVE VEERING WINDS EXCEPT UNR WITH BACKING FLOW. WILL USE THE GFS AND RUC. COLD FRONT WILL APPROACH SAT NIGHT. GFS INDICATING SOME NEGATIVE SHOWALTERS. MODEL SOUNDINGS HAVE LITTLE CIN AND MODEST CAPES IF LIFTED FROM 850 HPA TONIGHT. WILL ADD CHANCE OF THUNDER IN NORTHWEST ZONES TONIGHT. NEXT UPPER WAVE OVER BC WILL SWEEP ACROSS MB AND ONTARIO SUN WITH A COLD FRONT DROPPING OUT OF CANADA SUN. .LONG TERM... TEMPS TWEAKED. && .AVIATION... FOG LOOP AND SURFACE OBS SHOW MVFR AND SOME IFR CIGS OVER THE WESTERN DAKOTAS AND WAS MOVING NORTH INTO ND. WILL BRING LOWER CIGS INTO FAR THIS MORNING. LOW CLOUDS MAY REACH GFK LATER THIS MORNING. OTHERWISE LOW CLOUDS EXPECTED TO SHIFT EAST ACROSS SD AND SOUTHERN ND THIS AFTERNOON AND TONIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ HOPPES nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 1112 AM EDT SAT AUG 4 2007 .SYNOPSIS... SURFACE WEAK LOW PRESSURE IS LOCATED OFFSHORE. WEAK TROUGH OF LOW PRESSURE WILL LINGER OVER THE AREA TODAY. AN UPPER RIDGE WILL THEN BUILD OVER THE SOUTHEAST THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... SHORT WAVE HAS MOVED EAST OF THE AREA. RUC SHOWS WIND MAINLY DOWNSLOPE WINDS FOR THE AFTERNOON. EXPECT CONVERGENCE ALOFT. CONVERGENCE ALONG SURFACE TROUGH MAY TRIGGER ISOLATED CONVECTION. WILL KEEP POPS BELOW 15 PERCENT. TEMPS OFF TO A WARM START...IN THE LOW/MID 80S AND DEWPOINTS IN THE UPPER 60S/LOW 70S. MIXING SHOULD BRING LOWER DEWPOINTS FOR THE AFTERNOON. WILL RAISE TEMPS A DEGREE OR TWO. HIGHS IN THE LOW/MID 90S ARE EXPECTED. ALSO DECREASED CLOUD COVER. && .SHORT TERM /8 PM THIS EVENING THROUGH MONDAY/... MID/UPPER LEVEL WEAKNESS ALONG THE EAST COAST WILL GRADUALLY SHIFT EWD THROUGH THE PERIOD AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST. AT THE SURFACE...WEAK SURFACE SYSTEMS ALONG THE COAST WILL CONTINUE TO MAINLY STAY SOUTH OF THE AREA. GFS APPEARS TO BE A LITTLE FASTER WITH MOVING THESE SYSTEMS EWD. AS RIDGING GRADUALLY PUSHES EWD...MODEL SOUNDINGS INDICATE AIRMASS TO BECOME SLIGHTLY CAPPED THROUGH SUNDAY AND CHANCES FOR PCPN CONTINUE TO DECREASE. WILL KEEP POPS MOSTLY BELOW SLIGHT CHANCE. MODEL CONSENSUS MAX TEMPS STILL A COUPLE OF DEGREES ON THE HIGH SIDE BUT EXPECT FORECAST MAX TEMPS IN THE MID 90S AT MOST LOCATIONS SUNDAY AND MONDAY UNDER MOSTLY SUNNY/PARTLY CLOUDY SKIES. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... NO CHANGES TO THE EXTENDED FORECAST AT THIS TIME. GFS SHOWS MID/UPPER LEVEL RIDGE TO CONTINUE BUILDING EWD ACRS THE AREA EARLY NEXT WEEK AND CONTINUING THROUGH THE WEEK. CHANCE FOR POPS LOOKS LOW WITH RIDGE OVERHEAD...BUT WILL MENTION A SLIGHT CHANCE FOR THE MIDDLE/END OF NEXT WEEK. TEMPERATURES LOOK TO BE ABOVE NORMAL THROUGH THE PERIOD WITH BELOW NORMAL CHANCE FOR PCPN. WITH INCREASING TEMPS AND DEWPOINTS TEMPS IN THE LOWER 70S WILL RAISE HEAT INDEX VALUES AROUND 105 DEGREES BY NEXT WEEK. WILL NEED TO MONITOR FOR HEAT ADVISORY POTENTIAL. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... STRATUS ACROSS THE SRN MIDLANDS DISSIPATING. VFR CONDITIONS EXPECTED REST OF THE PERIOD AS DRIER AIR ADVECTS INTO THE AREA. AVIATION OUTLOOK 06Z SUNDAY THROUGH THURSDAY... NO SIGNIFICANT IMPACTS EXPECTED. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ SYNOPSIS...10 NEAR TERM...10 AVIATION...07 ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1036 AM EDT SAT AUG 4 2007 .SYNOPSIS... AN AREA OF LOW PRES WILL GRADUALLY MOVE EAST OF SOUTH CAROLINA THROUGH TONIGHT. A WEAK SURFACE TROUGH WILL LINGER ACROSS THE REGION INTO MID WEEK AS AN UPPER RIDGE BUILDS FROM THE WEST AND SOUTHWEST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WATER VAPOR IMAGERY SHOWS UPPER TROUGH AXIS SHIFTING EAST ACROSS THE CENTRAL CAROLINAS...PUSHING THE TROPICAL MOISTURE PLUME FARTHER OFF OUR COAST. ON VISIBLE...SFC LOW CAN BE EASILY SEEN SPINNING JUST OFF THE CHS COAST...WITH WRAP-AROUND MOISTURE RETAINING A LOW STRATUS DECK ACROSS MUCH OF SOUTHEAST GA AND SOUTHERN SC. PARTIAL CLEARING OCCURRED DURING THE LAST TWO HOURS ACROSS THE TRI-COUNTY AREA...BUT QUICKLY FILLED IN WITH CU AS SFC TEMPS ROSE. SFC LOW SHOULD PULL THE FRONTAL BOUNDARY FARTHER OFFSHORE TODAY WHILE A DOWNSLOPE FLOW BEGINS. HOWEVER...DEPENDING UPON HOW QUICKLY THE DOWNSLOPING BEGINS...CLOUD COVER COULD PERSIST FOR SEVERAL MORE HOURS ACROSS MUCH OF THE AREA. THIS WILL SIGNIFICANTLY IMPACT HIGH TEMP FORECAST FOR TODAY. NAM AND RUC SHOW DOWNSLOPE FLOW CRANKING UP BY 18Z WITH LLVL MOISTURE SHIFTING OFFSHORE BETWEEN 18 AND 20Z. AM THINKING THE CLOUDS SHOULD BE THINNING BEFORE 18Z...WITH RAPID CLEARING DURING THE LATE AFTERNOON DUE TO 850 MB SUBSIDENCE. COMPRESSIONAL WARMING COULD HELP TEMPS RECOVER QUITE RAPIDLY DURING THE AFTERNOON...BUT DO NOT SEE INTERIOR SECTIONS OF THE CWFA MAKING IT TO 90 T0DAY. BUMPED HIGH TEMPS DOWN A FEW DEGREES IN THOSE AREAS. ISOLATED SHOWERS AND TSTMS ARE POSSIBLE THIS AFTN ALONG A WEAK SEABREEZE BOUNDARY. CONVECTIVE PARAMETERS WILL BE QUITE WEAK AND GENERAL SUBSIDENCE SHOULD LIMIT CONVECTIVE DEVELOPMENT. PARED POPS BACK TO SLIGHT CHANCE OVER THE WATERS AND RIGHT ALONG THE COAST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... ISOLATED CONVECTION PSBL ALONG THE IMMEDIATE COAST VERY EARLY EVENING WILL GIVE WAY TO CLEARING SKIES TONIGHT. THERE COULD BE SOME MORE PTCHY FOG BUT HAVE NOT ADDED TO FORECAST AT THIS JUNCTURE. SUNDAY WILL SEE UPPER RIDGING BUILDING IN THE WSW AND WE WILL START TO SEE HEAT BUILDING IN EARNEST. HIGHS IN THE UPPER 90S AT SOME AREAS INLAND...NEAR 90 CLOSE TO THE COAST. ISOLATED AFTN TSTMS PSBL S OF THE SAVANNAH RIVER...BUT MOST AREAS DRY. HEAT INDICES WILL PEAK 100-105 IN THE AFTN BETWEEN THE COAST AND WELL INLAND WHERE DEW POINTS FCST TO BE SLIGHTLY LOWER. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... FAVORABLE PATTERN FOR EXCESSIVE HEAT MUCH OF THE UPCOMING WEEK WITH UPPER RIDGE IN PLACE. A ILL DEFINED AXIS OF DEEPER MID LEVEL MOISTURE WILL PERSIST MAYBE BRINGING SOME SCT MID CLOUD AT TIMES BUT OVERALL WEAK LAPSE RATES THANKS TO WARM TEMPS ALOFT SUGGEST RNFL CHCS ON THE LOW END. WILL CONTINUE TO HIGHLIGHT THE HOT WEATHER ISSUES IN THE HAZARDOUS WEATHER OUTLOOK. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... LIFR TO IFR CIGS AND SOME IFR VSBYS HAVE DEVELOPED UNDER A STRENGTHENING INVERSION THIS MORNING. LATEST MODEL DATA INDICATES THE CIGS WILL LIFT THROUGH MID MORNING BUT HAVE A TOUGH TIME BURNING OFF UNTIL LATE MORNING. WE HAVE MAINTAINED THIS TREND FOR BOTH KCHS AND KSAV TAFS AT 12Z. LAYERED CLOUDS APPEAR A LITTLE THICKER IN SOUTHEAST GEORGIA AND THIS MAY EVEN FURTHER DELAY IMPROVING CONDITIONS AT KSAV. BY THIS AFTN...CLOUDS BECOMING SCT BY MIDDAY AND VFR CONDITIONS EXPECTED. TOO MUCH MID LEVEL SUBSIDENCE TO MENTION CB AT EITHER TERM THIS AFTN. TONIGHT...DRIER AIR AT H7 BUT NOT VERY DRY AT H85. WE THINK THIS SHOULD BE A DETERRENT FOR MUCH FOG FORMATION DESPITE WET SOILS AND CLEAR SKIES WITH LIGHT W WINDS. EXTENDED AVIATION OUTLOOK... MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK. && .MARINE... BRIEF DENSE FOG EVENT IN THE HARBOR HAS BEEN DIMINISHING RAPIDLY OVER THE PAST HOUR BASED ON WEB CAM IMAGERY. WINDS AND SEAS HAVE SUBSIDED SIGNIFICANTLY THIS MORNING AS SFC LOW PUSHES FARTHER OFFSHORE AND TIGHTEST PRES GRADIENT REMAINS TO ITS EAST. WINDS ARE SLOWLY VEERING AT ALL BUOY LOCATIONS...WITH HIGHEST WIND SPEEDS 15-20 KT OVER AMZ374. WILL CONTINUE PREVIOUS TRENDS OF VEERING WINDS AND SUBSIDING SEAS THROUGH THIS AFTN. HIGH PRESSURE WILL THEN BUILD WESTWARD INTO THE FORECAST AREA TONIGHT AND WILL REMAIN THE DOMINANT WEATHER FEATURE THROUGH MUCH OF THE UPCOMING WORK WEEK. WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW HEADLINE CRITERIA THROUGH THE FORECAST PERIOD. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ JRL ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 953 AM MDT SAT AUG 4 2007 .DISCUSSION...GRIDS UPDATED AND FORECAST TEXT/TABULAR PRODUCTS ALREADY SENT. A WAVY MOISTURE AXIS ACROSS SW IDAHO HAS A HINT OF A WAVE ACROSS SE OREGON/NW NV BEHIND IT. WAVE CROSSES THROUGH BOISE MOUNTAINS THIS AFTERNOON WHERE CAP IS LIMITED TO ONLY AROUND -40 J/KG PER NAM12 AND RUC. ALREADY HAD LIGHTNING STRIKES IN SW OWYHEE COUNTY AND REMNANTS OF THAT CELL SHOW VIRGA EAST OF NWS WFO HEADED TOWARDS IDAHO CITY. UPPED POPS THIS MORNING AND EXPANDED POPS THIS AFTERNOON FOR THIS FEATURE THROUGH SW IDAHO. WEST CENTRAL MOUNTAINS COULD SEE OUTFLOW WINDS THIS AFTERNOON/EVENING BUT MOIST AXIS ONLY NIPS AT HEELS OF SE VALLEY COUNTY. SATELLITE IMAGERY SHOWS WIDESPREAD SMOKE OVER LONG VALLEY SO UPDATED SHORT TERM GRIDS TO AREAS OF SMOKE OVER WEST CENTRAL MOUNTAINS. PATCHY SMOKE ELSEWHERE OVER SW IDAHO INCLUDING THE TREASURE VALLEY IS EXPECTED TO MIX OUT WELL BOTH HORIZONTALLY AND VERTICALLY AS HIGH MIXING HEIGHTS COMBINE WITH SOUTHWEST 10 TO 20 MPH WINDS IN THE MIXED LAYER EACH AFTERNOON. OVERNIGHT RUNS HAVE BROUGHT THE HEIGHTS DOWN FOR COOLEST TEMPS MONDAY AS A SERIES OF SHORTWAVE ENERGY IMPULSES ROUNDING THE BASE OF THE LONG WAVE TROUGH OFF SW OREGON DRIVE LOWER HEIGHTS INLAND. ANY LONGER TERM UPDATES WILL BE MADE FOR THE AFTERNOON PACKAGE. && .AVIATION...LIGHTNING ALREADY OCCURRING SOUTHWEST CORNER OF IDAHO WILL MOVE ENE INTO S CENTRAL IDAHO 18Z-00Z. DRIER AND MORE STABLE AIR MASS WEST OF MYL-BOI-WMC LINE. LIGHT SURFACE WINDS TIL 18Z WILL BECOME WEST 5-15 KNOTS 18Z-00Z. BETTER VISIBILITY TODAY AS MODERATE SOUTHWEST WINDS ALOFT SHIFT SMOKE FURTHER EAST. && .PREV DISCUSSION... SHORT TERM...A SUBTLE CHANGE IN AIR MASS IS DEVELOPING OVER THE FORECAST AREA TODAY BUT ESPECIALLY NOTICEABLE BY SUNDAY WHEN COOLER TEMPERATURES ARRIVE. AN UPPER LEVEL TROF IS FORECAST TO MOVE ACROSS THE REGION WITH THE MAIN PART OF THE FEATURE CROSSING NORTHERN IDAHO. THIS WILL LOWER THE HEIGHTS AND THICKNESS VALUES AND PUSH ANY REMAINING MONSOONAL MOISTURE FARTHER TO THE EAST AND SOUTH. WHAT IS LEFT IN ITS PLACE IS A VERY DRY WEDGE OF AIR STREAMING UP FROM THE SOUTHWEST WELL AHEAD OF THE UPPER LOW DROPPING DOWN THE WEST COAST. HAVE LOWERED THE MAX TEMPS SLIGHTLY FOR TODAY BUT EVEN MORE SO ON SUNDAY AS THE UPPER TROF PASSES THRU THE AREA. A SMALL AREA OF UPPER LEVEL MOISTURE WILL PUSH NORTHEAST AHEAD OF THIS TROF ON SUNDAY BUT WILL DO LITTLE MORE THAN SPREAD SCATTERED TO BROKEN HIGH CLOUDS OVER THE AREA. HAVE LIMITED POPS TO 10 TO 15 PERCENT IN AREAS ADJACENT TO KMSO AND KPIH FOR THIS AFTERNOON AND AGAIN SUNDAY AFTERNOON. AS TROF CROSSES AND UPPER HEIGHTS FALL...UPPER WINDS ARE EXPECTED TO INCREASE FROM OUT OF THE SOUTHWEST. COMBINED WITH THE VERY LOW RH/S...NOT A GOOD THING FOR FIRE WEATHER CONCERNS BUT JUST BELOW WARNING CRITERIA. AREAS OF SMOKE WILL AGAIN BE PRESENT IN VALLEY AND BOISE COUNTIES BUT INCREASING SOUTHWEST WINDS ALOFT WILL PUSH THIS SMOKE AWAY FROM THE TREASURE VALLEY OF SOUTHWEST IDAHO. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...MODELS HAVE CONTINUED THE TREND OF A TROF TO REMAIN GENERALLY OVER THE WASHINGTON AND OREGON COAST THROUGH THE EXTENDED WITH THE SOUTHERN SECTION OF THE TROF OFF THE CENTRAL CALIFORNIA COAST. MODELS SHOW A PIECE OF THE PACIFIC NORTHWEST TROF WILL MOVE ACROSS NORTHERN AND CENTRAL IDAHO ON TUESDAY FOR A CHANCE OF THUNDERSTORMS OVER NORTHERN ZONES. OTHERWISE WITH THIS PATTERN OVER THE WESTERN SECTION OF THE COUNTRY THE DEEP MONSOON MOISTURE WILL STAY TO THE SOUTH AND EAST OF THE FORECAST AREA. THERE WILL STILL BE ENOUGH MOISTURE AND INSTABILITY OVER THE FORECAST AREA FOR A MENTION OF AT LEAST ISOLATED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS MAINLY OVER THE HIGHER TERRAIN. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && $$ WEATHER.GOV/BOISE DISCUSSION...VM AVIATION.....LC PREV SHORT TERM...GS PREV LONG TERM....JA id AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 712 AM EDT SAT AUG 4 2007 UPDATED AVIATION SECTION FOR 12Z TAF ISSUANCE .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER THE GRT LKS BTWN SLOWLY RETREATING VORTEX IN NRN QUEBEC AND UPR RDG OVER THE PLAINS. SFC HI CENTER IS SITUATED NEARLY OVER THE CWA...AND ASSOCIATED AIRMASS IS PARTICULARLY DRY/STABLE AS SHOWN ON 00Z INL/GRB SDNGS (PWAT/KINX 0.49 INCH/2 AND 0.58 INCH/1 RESPECTIVELY). SO SKIES GENERALLY CLR ATTM. HOWEVER...SOME HI CLDS TO THE E OF AREA OF SHRA/TSRA OVER ND TO THE NE OF H85 WARM FNT/AHEAD OF H5 SHRTWV MOVING TOWARD THE NRN PLAINS ARE SPILLING INTO THE UPR LKS. ANOTHER AREA OF SHRA/TSRA NOTED TO THE S OVER SD/NB. MAIN FCST CONCERNS TDAY ARE RELATED TO FIRE WX. FOCUS FOR TNGT/SUN TURNS TO PCPN CHCS ASSOCIATED WITH H85 WARM FNT NOW IN THE NRN PLAINS. FOR TDAY...LATEST GFS/NAM SHOW CENTER OF HI PRES DRIFTING SLOWLY TO SE ONTARIO BY 00Z SUN. AREA OF LOWEST PWAT BLO 0.75 INCH PROGGED TO LINGER THRU THE DAY OVER THE E HALF. OTRW...00Z NAM F6 H85-7 FGEN FIELD CORRELATES WELL WITH OBSVD AREA OF SHRA/TSRA NOW IN ND. MODEL TENDS TO MOVE THIS FORCING MORE NE INTO NW ONTARIO. SO ALTHOUGH SOME HI CLD WL SPILL INTO THE WRN FA WHERE GUIDANCE SHOWS PWAT INCHING ABV 1 INCH...SKIES SHOULD BE MOSUNNY. MIXING TO H8 ON GFS/NAM FCST SDNGS YIELD HI TEMPS ARND 80-82 AWAY FM LK MODERATION. RETURN SLY FLOW ON THE BACK SIDE OF HI DRIFTING TO THE E WL TRANSPORT A BIT HIER LLVL MSTR INTO THE FA AS COMPARED TO YDAY. BUT SINCE LLVL DRY AIR HAS SPREAD FAIRLY FAR TO THE S...PREFER THE SOMEWHAT DRIER LLVLS OF THE GFS FCST SDNGS...WHICH WOULD SUG DWPTS WL MIX OUT AS LO AS 40 TO 45 AGAIN AWAY FM MODERATING FLOW OFF THE LK. T/TD OF 80/45 WOULD LOWER RH TO JUST BLO 30 PCT...AND T/TD OF 80/40 WOULD YIELD 25 PCT. EVEN IF THE LOWER RH VALUES VERIFY...EXPECTED WINDS APPEAR TO BE TOO LO FOR FIRE WX WATCH/WRNG. WL REISSUE WILDFIRE POTENTIAL STATEMENT TO HIGHLIGHT CONTINUED HIER RISK FOR WILDFIRES. NAM REMAINS THE WETTEST OF THE MODELS FOR TNGT SHOWING AN H85 SW WIND OF 40 KTS RETURNING QUITE A BIT OF LLVL MSTR. NAM QPF ALG THE WI BORDER FCST TO ARPCH 0.35 INCH. GFS IS STILL ONE OF THE DRIER SCENARIOS AND SHOWS NO QPF. CONSIDERING MODELS SHOW MAIN H85 WARM FNT LINGERING TO THE S AND NAM IS TRENDING WEAKER WITH THE IMPULSE/ LOWER WITH THE QPF...SEEMS THE GFS IS PROBABLY ON THE RIGHT TRACK. TEMPTED TO DISCOUNT THE NAM ALTOGETHER...BUT 00Z CNDN SHOWS QPF FARTHER N TO AREA OF SHARP H85-7 FGEN AT 12Z SUN ACRS THE NRN CWA AND MORE CONFLUENT H85 WINDS...ALSO WELL N OF THE SHARPER H85 FNT. RUC13 MODEL ALSO SHOWS PCPN SPREADING FARTHER TO THE N...SIMILAR TO AT LEAST SOME OF THE SREF MEMBERS. WITH H85 WARM FNT SO FAR TO THE S AND ANTECEDENT AIRMASS SO DRY...STILL LIKE THE CONSISTENT GFS FCST DESPITE THE OTHER MODEL SUPPORT FOR A SCENARIO SIMILAR TO THE NAM. HOWEVER...OPTED TO SPREAD LO CHC POPS FARTHER N IN THE 06Z-12Z TIMEFRAME THAN CURRENTLY FCST BASED ON THE ARRAY OF SUPPORT...AND USED CNDN MODEL SHARPER FGEN FCST AS THE LINE SO ADVANCE THE POP. WL END PCPN CHCS W-E ON SUN AS MODELS WHICH SUPPORT PCPN SHOW H85 FLOW VEERING TO MORE W IN THE WAKE OF TROF. SINCE THE GFS/NAM DIVERGE SO MUCH ON THE FCST TNGT...EACH PAINTS A VERY DIFFERENT PICTURE OF WHAT WL HAPPEN ON SUN. NOT SURPRISINGLY...GFS SHOWS A MUCH DRIER LLVL ENVIRONMENT OVER THE E WITH MORE SUNSHINE/DWPTS ARND 50 AT ERY THRU THE DAY. NAM HINTS DWPTS WOULD RISE INTO THE 60S WITH MORE CLD COVER. BOTH MODELS DO SHOW A CONSIDERABLE RISE IN LLVL MSTR OVER THE W IN ADVANCE OF SFC LO TRACKING ACRS CNTRL CNA. TENDED TOWARD THE GFS FCST SCENARIO GIVEN PREFERENCE FOR THE MORE MINIMAL MSTR TRANSPORT TO THE NE TNGT. COLD FROPA FCST SUN NGT ATTENDANT TO SFC LO TRACKING ACRS CNTRL CAN. NAM IS QUITE A BIT STRONGER WITH THIS LO...EXHIBITING A STRONGER WNW FLOW IN ITS WAKE/FASTER COLD FROPA. TENDED TOWARD A COMPROMISE UKMET SCENARIO...WHICH SUGS BNDRY WL REACH NR ERY-MNM AT 12Z MON. SINCE ANY DEEPER MSTR EXITS DURING THE DAY ON SUN WITH SYS RESPONSIBLE FOR PCPN CHCS LATE TNGT/SUN AND FROPA WL BE IN ABSENCE OF ANY DIURNAL HTG...EXPECT THE FROPA WL BE DRY DESPITE SOME FAIRLY STEEP H85-5 LAPSE RATES 7-7.5C/KM. UKMET SHOWS SFC COLD FNT EDGING PAST THE SCNTRL AND ERN COUNTIES EARLY ON MON MRNG AND GIVING WAY TO HI PRES BLDG IN FM ONTARIO. EXPECT TEMPS OVER THE INTERIOR SCNTRL AWAY FM LK SUP MODERATION IN DVLPG NE FLOW TO RISE WELL INTO THE 80S PER MIXING TO H75-8 ON GFS FCST SDNGS AND UKMET H85 TEMP FCST JUST BLO 20C. SINCE PREVIOUS FCST HAD A 30 POP OVER THE ENTIRE FA...MAINTAINED THOSE LO CHC POPS IN THE AFTN OVER THE SCNTRL GIVEN CONSIDERABLE SFC HTG AND POTENTIAL FOR LK BREEZE CNVGC...ESPECIALLY IF SFC COLD FNT HANGS UP JUST TO THE S. GUIDANCE PERSISTS IN SHOWING SFC LO APRCHG THE CNTRL GRT LKS MON NGT/TUE...WITH MOST MODELS TRENDING S OF THE GFS FCST...WHICH MAY BE SUFFERING CONVECTIVE FEEDBACK AND DVLPG LO TOO FAR TO THE N. MAINTAINED GOING CHC POPS DURING THIS TIME. THEN WENT DRY ON WED TO REFLECT RDG BLDG IN THE WAKE OF THIS SHRTWV. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE NEXT 24 HOURS WITH A FEW HIGH CLOUDS CROSSING TODAY AND MID CLOUDS INCREASING TONIGHT. THESE MID CLOUDS WILL BE ASSOCIATED WITH A WAVE OF LOW PRES AND PCPN OVER SOUTHERN MN AND WESTERN WI. SOME OF THIS PCPN MAY MOVE INTO THE FORECAST AREA AND TAF SITES...BUT NOT LIKELY UNTIL AFTER 12Z SUN. EVEN THEN...MUCH OF THE PCPN SHOULD BE CONFINED TO THE SOUTH CENTRAL U.P.. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS ARE EXPECTED TO REMAIN BELOW 20 KT THROUGH THE PERIOD. HOWEVER...THERE ARE TWO PERIODS OF CONCERN WHERE THE WINDS COULD GET CLOSE TO 20 KT. THE FIRST IS LATE TONIGHT INTO SUN ON EASTERN LAKE SUPERIOR...DUE TO THE PRESSURE GRADIENT TIGHTENING BETWEEN A TROUGH ADVANCING EASTWARD ACROSS THE NORTHERN PLAINS AND HIGH PRESSURE MOVING TOWARDS NEW ENGLAND. THE SECOND IS ON ALL OF LAKE SUPERIOR LATE MON NIGHT INTO TUE MORNING AS A RESULT OF A LOW PRESSURE AREA MOVING FROM SOUTH DAKOTA ACROSS CENTRAL LAKE MICHIGAN...TIGHTENING THE PRESSURE GRADIENT BRIEFLY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...KC AVIATION...AJ MARINE...AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 1046 AM EDT SAT AUG 4 2007 .SYNOPSIS...AN UPPER LEVEL RIDGE WILL EXPAND INTO THE AREA FROM THE MIDWEST AND DOMINATE THE WEATHER PATTERN THROUGH NEXT WEEK...BRINGING ABOVE NORMAL TEMPERATURES AND BELOW NORMAL CHANCES FOR PRECIPITATION TO CENTRAL NORTH CAROLINA THROUGH MID TO LATE WEEK. && .NEAR TERM /THROUGH TONIGHT/... SFC ANALYSIS THIS MORNING SHOWS A 1015MB AREA OF LOW PRESSURE LOCATED NEAR CHARLESTON SC...WITH A SFC TROF AXIS EXTENDING NORTH INTO THE MID-ATLANTIC...AND FURTHER NORTH ALONG THE EAST COAST IN ASSOC/W LOW PRESSURE IN THE NORTHEAST STATES. DEWPOINTS ACROSS CENTRAL NC WERE IN THE MID 60S TO LOWER 70S. ALOFT...A TROUGH WAS ANALYZED AT 250MB OVER EASTERN NC/SC STRETCHING SOUTHWEST THROUGH SOUTHERN GA AND THE FLORIDA PANHANDLE. AN ANALYSIS OF WV IMAGERY AND RUC/NAM12 HEIGHT/VORT FIELDS DO NOT SHOW ANY VORT MAXES OR SHORTWAVES UPSTREAM OF THE AREA. MOISTURE AND INSTABILITY THIS AFTERNOON... THE 12Z GSO SOUNDING WAS SIMILAR TO FRIDAY`S SOUNDING...WITH A PWAT VALUE OF 1.26" AND SIMILAR MID-LEVEL TEMPS. THE SOUNDING SHOWED A BIT MORE DRY AIR IN THE MID-LEVELS THAN YESTERDAY. WITH TEMPS EXPECTED TO REACH INTO THE MID 90S THIS AFTERNOON...DEEP MIXING SHOULD ALLOW TO DEWPOINTS TO DROP ONCE AGAIN DURING PEAK HEATING. HOWEVER...GIVEN WHAT HAS HAPPENED THE PAST FEW DAYS...DEWPOINTS SHOULD REMAIN AT LEAST IN THE LOWER 60S ACROSS MOST OF THE AREA TODAY. THE 12Z GSO SOUNDING MODIFIED FOR A TEMP OF 93 AND A DEWPOINT OF 63 YIELDS A MEAN LAYER CAPE OF ABOUT 1000 J/KG THIS AFTERNOON. SFC AND UPPER LEVEL LIFT THIS AFTERNOON... A MORE WELL-DEFINED SFC TROF EXISTS ACROSS THE AREA THIS MORNING... AND IT SHOULD BECOME FURTHER DEFINED THIS AFTERNOON WITH TEMPS RISING WELL INTO THE MID AND POSSIBLY UPPER 90S. THE SFC CONVERGENCE ASSOC/W THE AXIS OF THIS FEATURE WILL PROVIDE A POTENTIAL FOCUS FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON. ALOFT...AFTER REVIEWING WV IMAGERY AND RUC/NAM12 MODEL DATA...IT DOES NOT APPEAR THERE WILL BE ANY SIGNIFICANT UPPER LEVEL FEATURES TO BENEFIT CONVECTIVE DEVELOPMENT. RUC 250MB HEIGHT/DIVERGENCE FIELDS ACTUALLY SHOW SOME UPPER LEVEL CONVERGENCE OVER THE AREA IN THE WAKE OF THE SHORTWAVE CURRENTLY PASSING TO THE EAST...WHICH COULD HELP SUPPRESS ACTIVITY. SUMMARY FOR THIS AFTERNOON... VERY ISOLATED SHOWER ACTIVITY DEVELOPED YESTERDAY AFTERNOON AROUND 18Z...AND WITH A SIMILAR THERMODYNAMIC SETUP TODAY AND A BETTER DEFINED SFC TROF OVER THE AREA THIS AFTERNOON TO ACT AS A FOCUS...WILL ADD A SMALL (10%) CHANCE FOR ISOLATED SHOWERS THIS AFTERNOON. BEST EDUCATED GUESS FOR WHERE THE TROF AXIS WILL SETUP APPEARS TO BE NEAR FAY-RDU-RZZ GIVEN THE ORIENTATION OF THE TROF AXIS THIS MORNING AND RUC/NAM12 FCST MSLP FIELDS. SOME UPPER LEVEL CONVERGENCE OVER THE AREA IN THE WAKE OF THE 250MB SHORTWAVE PASSING TO THE EAST MAY HELP INHIBIT CONVECTIVE DEVELOPMENT...HOWEVER...THE POSITIVE FACTORS (1000 J/KG OF MLCAPE AND SFC CONVERGENCE ASSOC/W TROF AXIS) SEEM TO OUTWEIGH THIS POTENTIAL NEGATIVE FACTOR...AND THAT IS THE BASIS FOR THE 10% CHANCE OF SHOWERS THIS AFTERNOON. HIGH TEMPS LOOK ON TRACK IN THE MID TO UPPER 90S WITH THICKNESSES AROUND 1440M. -VINCENT && .SHORT TERM /TONIGHT THROUGH MONDAY/... HIGH PRESSURE RIDGE WILL CONTINUE TO BUILD EAST TONIGHT. SO ANOTHER MILD...MUGGY NIGHT ON TAP. THERE IS SOME DIFFERENCE IN THE MODELS FOR SUNDAY... WITH THE TRACKING OF AN UPPER LEVEL LOW ACROSS THE NORTHERN/NORTHEAST PORTION OF THE CWA. THERE IS ALSO DIFFERENCES IN THE AMOUNT OF MOISTURE... GFS BEING THE WETTER MODEL. THESE DIFFERENCES ARE REFLECT IN THE PROJECTED HIGHS. MORE CLOUDS FROM THE GFS LEADS TO LOWER TEMPERATURES. I AM NOT SOLD ON ALL OF THE CLOUDS SO WILL GO WITH 95-97 OVER MOST OF THE AREA. THE UPPER RIDGE WILL SHIFT FURTHER EAST MONDAY THUS HEIGHTS WILL CONTINUE TO RISE... HIGHS GENERALLY IN THE LOW TO MID 90S. ONCE AGAIN INCREASED MOISTURE AND AFTERNOON HEATING WILL LEAD TO ISOLATED THUNDERSTORMS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HOT WEATHER CONTINUES THROUGH THE BALANCE OF THE WEEK WITH HIGHS IN THE LOW TO MID 90S AND LOWS IN THE LOW TO MID 70S. WEAK BOUNDARIES AT THE SURFACE COMBINED WITH WEAK UPPER LEVEL IMPULSES COULD LEAD TO ISOLATED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. && .AVIATION /THIS AFTERNOON THROUGH WEDNESDAY/... DIURNAL CU EXPECTED TO DEVELOP THIS AFTERNOON...WITH CEILINGS AT AROUND 7 KFT. VERY ISOLATED SHOWERS MAY DEVELOP THIS AFTERNOON AFTER 18Z...WITH THE POSSIBILITY REMAINING UNTIL 23-00Z. HOWEVER...COVERAGE WILL BE SO LOW THAT WILL NOT MENTION IN THE TAFS THIS AFTERNOON. AREAS OF PRIMARILY MVFR FOG AND HAZE LATE NIGHT THROUGH DAYBREAK INTO WEDNESDAY...OTHERWISE PRIMARILY VFR CONDITIONS ARE EXPECTED. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...RHJ LONG TERM...RHJ AVIATION...VINCENT/RLH nc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 1012 AM CDT SAT AUG 4 2007 .UPDATE...MAIN CHALLENGE WILL BE CLOUD TRENDS AND RESULTANT TEMPS FOR TODAY. MAIN FEATURE OF INTEREST FOR WILL BE WEAK SFC LOW ACROSS SD. THIS FEATURE WILL SLOWLY WANDER E TODAY...KEEPING THE FA IN LOW-LEVEL SOUTHERLY FLOW. LOW-CLOUDS ACROSS MOST OF SD AND CENTRAL ND SHOULD CONTINUE TO SLOWLY MOVE N/NE. CHALLENGE WILL BE HOW FAR N THE CLOUDS CAN MAKE IT. 12Z RUC APPEARS TO HAVE A GOOD HANDLE ON THESE CLOUDS (925-850MB RH)...SHOWING CLOUDS TO BE ALONG AND SOUTH OF A CANDO-GFK-BJI LINE BY AFTERNOON. THE FEATURE THAT WILL SCOUR OR MOVE THESE CLOUDS EAST WILL BE THE SFC TROUGH NOW ENTERING W ND (PROPAGATE THROUGH TONIGHT). WILL ADJUST SKY GRIDS TO ACCOUNT FOR THIS THINKING. WILL ALSO LOWER MAX TEMPS A CATEGORY ACROSS THE S AND W FA WHERE CLOUDS ARE CURRENTLY LOCATED. NO CHANGES NEEDED TO TEMPS ACROSS NE FA WITH MINIMAL CLOUD COVER EXPECTED. THE HARDEST AREA WILL BE IN BETWEEN WHERE CLOUDS ARE EXPECTED TO MOVE INTO. WILL GENERALLY NOT MAKE MUCH CHANGE TO TEMPS HERE...THINKING THAT MORNING SUN SHOULD ALLOW TEMPS TO BE CLOSE TO FORECAST (MAYBE 1-2 DEGREES LOWER). && .AVIATION...SATELLITE AND SURFACE OBS SHOW MVFR CIGS OVER CENTRAL ND AND MOST OF SD. THESE CLOUDS ARE MOVING NORTH. LOW CLOUDS WILL AFFECT FAR A MAJORITY OF THE DAY...AND MAY REACH GFK BY EARLY AFTERNOON. LOW CLOUDS EXPECTED TO SHIFT EAST ACROSS SD AND ND THIS AFTERNOON AND TONIGHT. && .PREV DISCUSSION... /ISSUED 430 AM CDT SAT AUG 4 2007/ SHORT TERM... PROGRESSIVE UPPER AIR PATTERN IS FORECAST ACROSS THE NORTHERN US AND SOUTHERN CANADA THROUGH THE PERIOD. UPPER LEVEL RIDGE OVER THE WESTERN SOUTHERN PLAINS SHIFTS OVER THE SOUTHEAST STATES BY 84 HOURS. UPPER LEVEL RIDGE OVER MB/SK WILL MOVE TO THE NEW ENGLAND/SOUTHERN QUEBEC BY SUN NIGHT. EMBEDDED UPPER TROUGH WAS OVER SD WILL MOVE OVER THE EASTERN GREAT LAKES BY SUN NIGHT. WATER VAPOR LOOP INDICATES SOME DRYING OVER WESTERN SD. RUC APPEARS TO HAVE THE BEST HANDLE ON WIND FIELD FROM THE AREA VAD WINDS IN THE NORTHERN PLAINS. MOST SITES HAVE VEERING WINDS EXCEPT UNR WITH BACKING FLOW. WILL USE THE GFS AND RUC. COLD FRONT WILL APPROACH SAT NIGHT. GFS INDICATING SOME NEGATIVE SHOWALTERS. MODEL SOUNDINGS HAVE LITTLE CIN AND MODEST CAPES IF LIFTED FROM 850 HPA TONIGHT. WILL ADD CHANCE OF THUNDER IN NORTHWEST ZONES TONIGHT. NEXT UPPER WAVE OVER BC WILL SWEEP ACROSS MB AND ONTARIO SUN WITH A COLD FRONT DROPPING OUT OF CANADA SUN. LONG TERM... TEMPS TWEAKED. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ TG/JH nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 253 PM PDT SAT AUG 4 2007 .DISCUSSION...SUNNY SKIES PREVAILED OVER THE DISTRICT AS THE FLOW ALOFT WAS NOW FROM THE SOUTHWEST. SMOKE FROM SOUTHERN CALIFORNIA WAS ALSO PUSHED INTO THE DISTRICT...BUT WAS NOT THICK ENOUGH TO PREVENT VALLEY TEMPERATURES FROM REACHING THE 100 DEG-F MARK. FURTHERMORE...SATELLITE IMAGERY ALONG WITH RUC80 UPPER AIR ANALYSIS SHOWED A CLOSED UPPER LOW JUST OFF THE NORTHERN CALIFORNIA COAST. WILL EXPECT THIS UPPER LOW TO TRACK EASTWARD AND TIMED TO HIT THE CENTRAL COAST BY SUNDAY MORNING. MOREOVER... MOISTURE MOVING AROUND THE UPPER RIDGE MAY GET CAUGHT INTO THE PREVAILING FLOW AND PUSHED INTO CENTRAL CALIFORNIA. WITH MOST OF THE DYNAMIC LIFT CONFINED TO NORTHERN CALIFORNIA...WILL ONLY MENTION CLOUD COVER FROM FRESNO COUNTY NORTHWARD ON SUNDAY. OTHERWISE...THE PASSAGE OF THE UPPER TROF WILL ALLOW FOR A GENERAL COOL DOWN ACROSS THE DISTRICT. MODELS CONTINUE TO PROG 850MB TEMP/S NEAR 22 DEG-C...WHICH TRANSLATE INTO SURFACE TEMP/S OF MID TO UPPER 90S. THIS WILL BE A DROP OF SOME 10 DEG-F FROM TODAYS READINGS. A POSSIBLE MARINE PUSH BEHIND THE TROF PASSAGE COULD LOWER TEMP/S IN THE UPPER 80S TO LOWER 90S. THEREFORE...MONDAY AND TUESDAY WILL BE THE PERIOD WITH THE COOLEST CONDITIONS BEFORE A WARMING TREND STARTS ON WEDNESDAY. FURTHERMORE...THE TROF PASSAGE WILL ALLOW WINDS TO INCREASE ON SUNDAY AND CONTINUES BLOWING ON MONDAY. TOWARD THE END OF NEXT WEEK...MODELS DO SLOWLY RAISE HEIGHTS TO MAINTAIN A WARMING TREND THROUGH THE END OF THE WEEK. YET...MEDIUM RANGE MODELS ARE NOW INDICATING A POSSIBLE TROF PASSAGE BY FRIDAY. WHILE SOME WARMING WILL BE OBSERVED DURING THE LATTER PARTS OF THE WEEK...ANOTHER COOLING TREND WILL BE POSSIBLE BY NEXT WEEKEND. YET...WILL KEEP THE DISTRICT BELOW NORMAL THROUGH THE PERIOD. && .AVIATION...AREAS OF SMOKE WILL PERSIST ABOVE 15 THOUSAND FEET MAINLY SOUTH OF FRESNO COUNTY THROUGH 00Z SUNDAY. OTHERWISE VFR CONDITIONS CAN BE EXPECTED OVER THE CENTRAL CALIFORNIA INTERIOR THROUGH 00Z MONDAY. FOR SPECIFIC DETAILS...PLEASE REFER TO THE TAFS FOR KMCE...KFAT AND KBFL...AND TWEB ROUTES 421 AND 423. && .AIR QUALITY ISSUES...NONE. && .HNX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MOLINA AVN/FW...JDB WEATHER.GOV/HANFORD ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 300 PM MDT SAT AUG 04 2007 SHORT TERM...DEEP PLUME OF SUBTROPICAL MOISTURE CONTINUES TO STRING OUT ALONG THE OUTER EDGE OF THE UPR LVL HIGH PRES RIDGE NOW CENTERED OVER NWRN TEXAS. THE CLOUD BAND EXTENDING OVER THE CWFA THIS AFTERNOON PRETTY MUCH AT THE CENTER OF THIS PLUME. EVEN WITH ALL THE MOISTURE AROUND CONVECTION HAS BEEN SLOW TO DEVELOP THIS AFTERNOON ESPLY IN MTN AREAS NORTH OF INTERSTATE 70 AND OUT ACROSS THE PLAINS. LATEST ACARS SOUNDINGS AT POINTS NORTH AND EAST OF DENVER INDICATE A STRONG STABLE LAYER UP AROUND 550 MBS. SAME SOUNDINGS ALSO INDICATE 5-15KT N/NWLY WINDS UP THROUGH 600 MBS AND 15-30KT SWLY FLOW ABOVE THAT. THOUGH THE STEERING FLOW ALOFT IS SOMEWHAT STRONGER TODAY STORM MOTIONS HAVE REMAIN LIGHT...GENERALLY FM A W-SWLY COMPONENT AT 10-15KT. HIGHEST RUC CAPE VALUES ON THE PLAINS UP AROUND 2200 J/KG UP AROUND FORT COLLINS AND ACROSS WELD COUNTY WHERE LGT S-SELY ANTICYCLONIC FLOW HAS ACCUMULATED AIR WITH NEAR 60F DEW POINTS. BUT STORMS HAVE YET TO FIRE IN THIS AREA. ELSEWHERE DEWPOINTS ON THE PLAINS HAVE SLOWLY FALLEN THROUGH THE DAY WITH THE LIGHT N-NWLY LOW-LEVEL FLOW THAT DEVELOPED EARLIER THIS MORNING FOLLOWING PASSAGE OF A WEAK FRONTAL SURGE. FOR THE REST OF THE AFTERNOON WOULD EXPECT TO SEE WDLY SCT/SCT T-STORMS FORMING OVER MTNS...ALONG THE FRONT RANGE FOOTHILLS AND PALMER DIVIDE...AND POSSIBLY UP ALONG THE CHEYENNE RIDGE AROUND FORT COLLINS. CUMULUS CLOUDS FORMING ACROSS LINCOLN COUNTY POSSIBLY ANOTHER AREA FOR LATE AFTERNOON AND EARLY EVENING STORM FORMATION...BUT SBCAPES AND MID-LEVEL STABILITY LESS FAVORABLE FOR DEEP CONVECTION IN THIS AREA. BELIEVE HEAVY RAIN LESS OF A THREAT THIS EVENING...ALTHOUGH ONE OR TWO STORMS AROUND PARK COUNTY...THE SOUTHERN FOOTHILLS AND WESTERN PORTION OF THE PALMER DIVIDE MAY STILL PRODUCE A BRIEF INTENSE SHOWER. OVERNIGHT...COULD SEE ISOLATED CONVECTION LINGERING IN THE HIGH COUNTRY AND POSSIBLY ON THE NEARBY PLAINS. MODELS SHOW A SHORTWAVE AND VORT MAX IN THE FOUR CORNERS REGION AND ANOTHER WEAKER MID-LEVEL IMPULSE PASSING OVER SRN IDAHO/NRN UTAH AT THIS HOUR. MODELS SHOW THESE FEATURES MERGING OVER NERN COLORADO SOMETIME AFTER MIDNIGHT. MEANWHILE WIND FIELDS SHOW LOW-LEVELS WINDS BACKING AROUND TO A SELY COMPONENT WHICH SLOWLY ADVECTS HIGHER DEW POINTS BACK UP IN THE CWFA. THEREFORE WILL KEEP AT LEAST A SLIGHT CHANCE OF SHWRS/T-STORMS IN THE HIGH COUNTRY AND NEARBY PLAINS OVERNIGHT. ON SUNDAY....MID-LEVEL SHORTWAVE MOVES EAST OF THE CWFA IN THE MORNING WITH QG VERTICAL VELOCITY FIELDS INDICATING SINKING MID/UPR-LEVEL AIR OVER THE AREA. HOWEVER BY THE AFTERNOON...MODELS SHOW S-SELY LOW-LEVEL FLOW STRENGTHENING ACROSS THE PLAINS WHICH INCREASES SFC DEWPOINTS AND THETA-E VALUES. ANOTHER WEAK MID-LEVEL IMPULSE EMBEDDED WITHIN THE MONSOON MOISTURE PLUME IS PROGGED TO SWING OUT OF ERN UTAH AND OVER NERN COLORADO BY 21Z/SUNDAY OR SO. ALTHOUGH SEE LITTLE IMPROVEMENT IN LAYER PRECIPITABLE WATER VALUES IN MTN AREAS. NEVERTHELESS SHOULD SEE STORMS BEGIN TO FIRE IN THE MTNS NOT LONG AFTER MIDDAY AND A FEW HOURS LATER ON THE NEARBY PLAINS. OUTFLOW BOUNDARIES GENERATED BY HIGH COUNTRY STORMS MAY BE NECESSARY TO INITIATE STORM DVLPMNT ON THE PLAINS. BY LATE AFTERNOON WITH PW VALUES INCREASING ON THE PLAINS COULD SEE A FEW HEAVY RAIN PRODUCING STORMS...ESPECIALLY ALONG THE PALMER DIVIDE AND ACROSS FAR ERN PORTIONS OF THE CWFA. TEMPERATURES ON SUNDAY ABOUT THE SAME AS TODAY. .LONG TERM...A WEAK MID LVL SHORTWAVE NOW OVR SRN AZ WL MOV THRU THE REGION MONDAY AFTERNOON WHICH SHOULD ENHANCE TSTM CHANCES TWD EVENING. THIS FEATURE HAS ITS ORIGINS WITHIN THE DEEP MONSOONAL FLOW OVR THE SOUTHWEST AND HIR PRECIP WATER WILL BE INVOF THE SHORTWAVE AS IT MOVES THRU THE CWA. THUS...TSTM COVERAGE LOOKS A BIT HIR MONDAY AFTN/EVENING. HWVR...STRONGER SOUTHWESTERLY FLOW AND FASTER STORM MOVEMENT SHOULD LIMIT QPF AND FLOODING SHOULD NOT BE OF CONCERN. TUESDAY...A WEAK UPR TROUGH WL MOV THRU MONTANA WITH AN ASSOCIATED TROUGH PASSING THRU THE DISTRICT TUESDAY EVENING. DUE TO THE WEAK ASCENT WITH THIS TROUGH TUESDAY EVENING...ELECTED TO KEEP POPS GOING OVERNIGHT AS WE COULD SEE SOME CONVECTION LAST OVERNIGHT. LOOKING AHD...STG HIGH PRESSURE WL RMN STATIONARY OVER THE SOUTHEAST CONUS. HWVR...A SERIES OF TROUGHS FM THE PACIFIC NW WL GRADUALLY CAUSE THE FLOW ALF TO TURN MORE TO THE SOUTHWEST ACRS OUR REGION. MAIN PLUME OF MONSOONAL MSTR WL MOVE TO OUR EAST...BUT CANNOT RULE OUT AFTN/EVENING STORMS IN THE HIGH COUNTRY AS THERE CONTINUE TO BE A THIN LYR OF MSTR IN THE MID LVLS. PLAINS SHOULD DRY OUT AS THE STORMS AFT WED OR THURS SHOULD BE HIGH BASED. TEMPS WL BE VERY WARM THIS WEEK WITH 90 OR BETTER EACH DAY ON THE PLAINS. WARMED UP TEMPS ABOUT 5 DEGREES ACRS THE BOARD ON LONG TERM FCST...BUT OTWS FEW CHGS NEEDED AT THIS TIME. && .AVIATION...ISOLD/WDLY SCT TSRA IN THE DENVER VCNTY THRU 03Z. BRIEF HVY RAIN AND TSRA WND GUSTS TO 30KTS A POSSIBLITY. ISOLATED -TSRA POSSIBLE OVERNIGHT ASA WEAK UPR LVL WX DISTURBANCE EXPECTED TO PASS OVERTHE AREA BTWN 06Z-09Z. VSBYS BRIEFLY MVFR WITH HVY RAINFALL WITH PASSING TSRA. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && $$ BAKER/046 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 148 PM MDT SAT AUG 4 2007 .SHORT TERM... (TONIGHT AND SUNDAY) ...HEAVY RAIN/FLASH FLOOD POTENTIAL CONTINUES FOR NEXT 24 HOURS... CURRENTLY...WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES SHOWED A LARGE ANTICYCLONE CENTER OVER OK/TX WITH SWLY FLOW OVER THE CNTRL ROCKIES. MIDDLE AND UPPER MOISTURE PLUME STILL EXTENDS FROM THE DESERT SW INTO THE CNTRL ROCKIES. 12Z/04 SOUNDING DATA HAD PRECIPITABLE WATER INDICES OF 150-200 PERCENT ACROSS THE REGION...SO A PRETTY MOIST ATMOSPHERE IS IN PLACE. REGIONAL RADAR DATA INDICATED SHOWERS AND TSTMS DEVELOPING...PER CLIMATOLOGY...OVER THE CO MOUNTAINS JUST AROUND NOON. A COUPLE OF MODERATE TO INTENSE CELLS HAVE GONE UP IN THE SANGRE DE CRISTO/WET MOUNTAINS AND PIKES PEAK EARLY THIS AFTN. A SHALLOW VERY WEAK COLD FRONT MOVED INTO THE PALMER DIVIDE AREA JUST BEFORE NOON...AND IS JUST SOUTH OF KCOS-KLIC-KITR. WINDS VEERING TO THE E-SE AT KCOS AS UPSLOPE FLOW STARTING TO INCREASE. LATE THIS AFTN AND TNGT...WELL...SUFFICIENT AMOUNTS OF FUEL(MOISTURE) AND CONVECTIVE ENERGY ARE IN PLACE LIKE THE LAST FEW DAYS. MODELS WANT TO BREAK OUT CONVECTIVE PRECIPITATION OVER THE MOUNTAINS AND DRIFT IT TO NEARBY VALLEYS AND SERN CO PLAINS...OR FORM OVER THE SERN CO PLAINS NEAR THE WEAK LOW LEVEL BOUNDARY. MODERATE TO HEAVY RAIN IS STILL THE MAIN TSTM IMPACT WEATHER GIVEN FREEZING LEVEL/WET BULB ZERO HEIGHTS OF 14K-17K FT MSL AND H7-H5 SPECIFIC HUMIDITY VALUES OF 6-8 G/KG. STORM CELL MOTION WILL BE TOWARDS THE E-NE AROUND 10KTS...SO STORMS WILL BE MOVING. THE ONLY POTENTIAL FOR SERIOUS HEAVY RAIN WILL BE FOR CELL TRAINING OR MERGERS. THE FLASH FLOOD THREAT WILL BE VERY SPOTTY AND COULD OCCUR JUST ABOUT ANYWHERE. GIVEN THE VERY LOCALIZED THREAT AND NOT WANTING TO CONTINUE BLANKETING THE ENTIRE CWFA IN FLASH FLOOD WATCHES LIKE THE PAST DAYS...PLAN TO NOT ISSUE FLASH FLOOD WATCH...BUT WILL CONTINUE MENTION OF HEAVY RAIN IN THE FORECAST AND MENTIONING FLASH FLOOD THREAT IN THE AFD AND HWO TEXT PRODUCTS. AS USUAL...OLD WILDFIRE BURN SCARS WILL BE SUSCEPTIBLE TO FLASH FLOODING. RAINFALL RATES COULD BE 1-2 INCHES PER HOUR THIS AFTN AND EVE. ROCK AND MUD SLIDES COULD OCCUR IN THE TYPICAL MOUNTAIN LOCATIONS OF STEEP/COMPLEX TERRAIN WITH LOOSE GRAVEL...BOULDERS...ETC. HAIL UP TO 1/2 INCH AND WIND GUSTS UP TO 45-50 MPH COULD BE POSSIBLE WITH INTENSE TSTM UPDRAFTS THIS AFTN AND EVE. WRF MODEL WANTS EVOLVE THE ISOLD-SCT SHOWERS AND TSTMS INTO A MESOSCALE CONVECTIVE SYSTEM OVER SERN CO LATER TNGT...BUT HAVE SOME QUANDARIES ABOUT THIS DEVELOPMENT. ANOTHER MILD AND MOIST NIGHT WILL BE IN THE OFFING. SUN...MORE OF THE SAME AND PERSISTENCE LOOKS LIKE A GOOD TOOL. CONVECTIVE PRECIPITATION SHOULD DEVELOP OVER THE MOUNTAINS AND DRIFT EWD INTO VALLEYS AND SERN CO PLAINS. THE MAIN TSTM IMPACT WEATHER MODERATE TO HEAVY RAIN...SMALL HAIL...AND LOCALLY GUSTY WINDS. TEMPERATURES SHOULD BE AT OR SLIGHTLY ABOVE EARLY AUG AVERAGES. METZE .LONG TERM... (SUNDAY NIGHT THROUGH SATURDAY) WILL KEEP THIS DISCUSSION RELATIVELY BRIEF AS RATHER OCCUPIED MONITORING AFTERNOON CONVECTION. CWFA PROJECTED TO REMAIN UNDER THE MOISTURE PLUME THROUGH AT LEAST TUESDAY...WITH LATEST MODELS INDICATING SOME DRYING INFILTRATING REGION FROM LATER WEDNESDAY INTO NEXT SATURDAY...ESPECIALLY EASTERN SECTIONS. MINIMUM AND MAXIMUM TEMPERATURES SHOULD CONTINUE TO RUN AT OR ABOVE CLIMATOLOGICAL AVERAGES DURING THE LONG TERM. GRADIENT WINDS ARE EXPECTED TO PICK UP SOMEWHAT FROM LATE NEXT WEEK INTO NEXT WEEKEND. SO FOR SENSIBLE WEATHER...HAVE PAINTED IMPENDING GRIDS/ZONES WITH WARM EARLY AUGUST TEMPERATURES AS WELL AS PRIMARILY AFTERNOON AND EVENING ISOLATED TO SCATTERED POPS THROUGH WEDNESDAY. GENERALLY ISOLATED POPS THEN EXPECTED TO OCCUR OVER THE CWFA FROM THURSDAY THROUGH NEXT SATURDAY. && .AVIATION... ISOLATED TO SCATTERED TSTMS WILL AFFECT KCOS...KPUB...AND KALS THROUGH 06Z/05 TNGT. THE MAIN THREAT WILL BE HEAVY RAIN WITH IFR-MVFR VIS/CIGS...ERRATIC WINDS WITH POTENTIAL GUSTS UP TO 35KTS...AND PEA SIZE HAIL. METZE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 144 PM EDT SAT AUG 4 2007 .SYNOPSIS... SURFACE LOW PRESSURE IS LOCATED OFFSHORE. WEAK TROUGH OF LOW PRESSURE WILL LINGER OVER THE AREA TODAY. AN UPPER RIDGE WILL THEN BUILD OVER THE SOUTHEAST THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... SHORT WAVE HAS MOVED EAST OF THE AREA. RUC SHOWS WIND MAINLY DOWNSLOPE WINDS FOR THE AFTERNOON. EXPECT CONVERGENCE ALOFT. CONVERGENCE ALONG SURFACE TROUGH MAY TRIGGER ISOLATED CONVECTION. WILL KEEP POPS BELOW 15 PERCENT. TEMPS OFF TO A WARM START...IN THE LOW/MID 80S AND DEWPOINTS IN THE UPPER 60S/LOW 70S. MIXING SHOULD BRING LOWER DEWPOINTS FOR THE AFTERNOON. WILL RAISE TEMPS A DEGREE OR TWO. HIGHS IN THE LOW/MID 90S ARE EXPECTED. ALSO DECREASED CLOUD COVER. && .SHORT TERM /8 PM THIS EVENING THROUGH MONDAY/... MID/UPPER LEVEL WEAKNESS ALONG THE EAST COAST WILL GRADUALLY SHIFT EWD THROUGH THE PERIOD AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST. AT THE SURFACE...WEAK SURFACE SYSTEMS ALONG THE COAST WILL CONTINUE TO MAINLY STAY SOUTH OF THE AREA. GFS APPEARS TO BE A LITTLE FASTER WITH MOVING THESE SYSTEMS EWD. AS RIDGING GRADUALLY PUSHES EWD...MODEL SOUNDINGS INDICATE AIRMASS TO BECOME SLIGHTLY CAPPED THROUGH SUNDAY AND CHANCES FOR PCPN CONTINUE TO DECREASE. WILL KEEP POPS MOSTLY BELOW SLIGHT CHANCE. MODEL CONSENSUS MAX TEMPS STILL A COUPLE OF DEGREES ON THE HIGH SIDE BUT EXPECT FORECAST MAX TEMPS IN THE MID 90S AT MOST LOCATIONS SUNDAY AND MONDAY UNDER MOSTLY SUNNY/PARTLY CLOUDY SKIES. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... NO CHANGES TO THE EXTENDED FORECAST AT THIS TIME. GFS SHOWS MID/UPPER LEVEL RIDGE TO CONTINUE BUILDING EWD ACRS THE AREA EARLY NEXT WEEK AND CONTINUING THROUGH THE WEEK. CHANCE FOR POPS LOOKS LOW WITH RIDGE OVERHEAD...BUT WILL MENTION A SLIGHT CHANCE FOR THE MIDDLE/END OF NEXT WEEK. TEMPERATURES LOOK TO BE ABOVE NORMAL THROUGH THE PERIOD WITH BELOW NORMAL CHANCE FOR PCPN. WITH INCREASING TEMPS AND DEWPOINTS TEMPS IN THE LOWER 70S WILL RAISE HEAT INDEX VALUES AROUND 105 DEGREES BY NEXT WEEK. WILL NEED TO MONITOR FOR HEAT ADVISORY POTENTIAL. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... MOISTURE LIMITED ACROSS THE AREA THROUGH THE PERIOD. UPPER AIR DISTURBANCE MOVING OFF THE COAST THIS AFTERNOON WITH DRY AIR IN THE MID AND UPPER LEVELS. EXPECT SCT/BKN CUMULUS THIS AFTERNOON 5 TO 6 THOUSAND FEET TO DISSIPATE WITH SUNSET. COULD BE AN ISOLATED SHOWER OR THUNDERSTORM THIS AFTERNOON WITH SURFACE TROUGH OVER THE PIEDMONT. AFTER SUNSET CLEAR SKIES. COULD GET MVFR FOG 08-12Z AT KAGS/KOGB...OTHERWISE VFR CONDITIONS CONTINUE. AVIATION OUTLOOK 18Z SUNDAY THROUGH THURSDAY... NO SIGNIFICANT IMPACTS EXPECTED. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 256 PM MDT SAT AUG 4 2007 .DISCUSSION... MAIN FORECAST CONCERN AGAIN CENTERS ON PRECIP CHANCES AND TEMPS THROUGH THE SEVEN DAY PERIOD. MORNING UPPER AIR ANALYSIS SHOWS A BROAD MID/UPPER RIDGE OVER THE SOUTHERN U.S. MEANWHILE A WEAK SFC BOUNDARY LIES ACROSS CENTRAL NEBRASKA PER LATEST MSAS ANALYSIS WITH A SFC LEE TROUGH NEAR THE KANSAS/COLORADO BORDER. RUC/GFS/NAM INDICATE THIS FRONT WILL SLOWLY SINK SOUTH TONIGHT. WITH WEAK CONVERGENCE ALONG THIS BOUNDARY...TSRA APPEARS POSSIBLE TONIGHT AS DEEP MOISTURE REMAINS IN PLACE WITH FCST POINT SOUNDINGS SHOWING PWAT VALUES OF AROUND 1.50 INCHES. LOCALLY HEAVY RAIN REMAINS THE MAIN THREAT WITH THIS CONVECTION. PATTERN CHANGES VERY LITTLE SUN AND MON ALTHOUGH MODELS HAVE BEEN CONSISTENT IN MOVING THE RIDGE TOWARD THE SOUTHEAST U.S. CONVERGENCE ALONG A PERSISTENT SFC LEE TROUGH ALONG WITH SEVERAL WEAK VORT MAXES ROTATING INTO THE AREA ON SOUTHWESTERLY FLOW ALOFT WILL LEAD TO DAILY CHANCES OF TSRA. TEMPS WILL CONTINUE TO RUN ABOVE NORMALS AS 850 HPA TEMPS CLIMB TO NEAR THE 30 DEGREE C MARK YIELDING HIGHS WELL INTO THE 90S. FOR TUE...A DIFFUSE SFC BOUNDARY WILL HEAD INTO THE REGION WHILE A SFC LEE TROUGH REMAINS ESTABLISHED NEAR THE KANSAS/COLORADO BORDER. WITH SOUTHWESTERLY FLOW ALOFT...AMPLE LLVL MOISTURE WILL REMAIN IN PLACE. GIVEN THE ABOVE...INSERTED CATEGORICAL POPS TUE EVENING ESPECIALLY TO AREAS NORTH OF I-70 WHERE MID LEVEL TEMPS ARE EXPECTED TO BE A FEW DEGREES COOLER. THE FLOW ALOFT WILL REMAIN SOUTHWESTERLY WITH CONTINUED MOISTURE ADVECTION IN THE AREA. WEAK SFC GRADIENT WILL LIMIT WIDESPREAD PRECIP COVERAGE. PRECIP CHANCES DIMINISH WED EVENING OUT WEST AS MAIN UPPER DYNAMICS ASSOCIATED WITH SFC LOW LIFT TO THE NORTHEAST. A 40 KT H85 JET WILL ALSO DEVELOP FURTHER EAST WED NIGHT...SHIFTING THE FOCUS OF CONVECTION FURTHER EAST. DID HOLD ONTO SLIGHT CHANCE POPS FURTHER EAST OF FCST AREA IN CLOSER PROXIMITY OF THETA-E ADVECTION. TEMPS BOTH TUE AND WED WILL ONCE AGAIN REMAIN WELL INTO THE 90S. MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT WITH THE SOUTHEAST U.S. RIDGE RETROGRADING NEAR THE MISSISSIPPI RIVER VALLEY TOWARD THE END OF THE WEEK. WITH RISING HEIGHTS...TEMPS INCREASING A COUPLE OF DEGREES MORE LOOKS PLAUSIBLE. PRECIP CHANCES ALSO APPEAR MINIMAL ALTHOUGH ECMWF AND GFS ONCE AGAIN INDICATE SEVERAL ILL-DEFINED S/WV TROUGHS ROTATING ON THE NORTHERN PERIPHERY OF THIS RIDGE... CONFIDENCE IS LOW IN THE DETAILED TIMING SO LEFT EXTENDED DRY ATTM. && .AVIATION...FOR THE 18Z TAFS...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND EXPAND IN COVERAGE THROUGH THE REST OF THE DAY AND INTO THE EVENING AS AN UPPER LEVEL DISTURBANCE INTERACTS WITH A SURFACE TROUGH OVER THE AREA. VFR CONDITIONS ARE GENERALLY EXPECTED BUT IF A STORM MOVES OVER THE KGLD AND KMCK AIRPORTS VISIBILITIES AND CEILINGS COULD QUICKLY DROP INTO THE MVFR OR IFR RANGE AS HEAVY RAIN OBSTRUCTS VISIBILITIES. THIS IS EXPECTED AFTER 22Z OR SO AND WILL CONTINUE THROUGH 06Z. ONCE THE PRECIPITATION ENDS TONIGHT EXPECT CIRRUS OF A SCATTERED TO BROKEN VARIETY THROUGH 18Z SUNDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ CLK/DDT ks AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1257 PM EDT SAT AUG 4 2007 UPDATED AVIATION SECTION FOR 18Z TAF ISSUANCE .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER THE GRT LKS BTWN SLOWLY RETREATING VORTEX IN NRN QUEBEC AND UPR RDG OVER THE PLAINS. SFC HI CENTER IS SITUATED NEARLY OVER THE CWA...AND ASSOCIATED AIRMASS IS PARTICULARLY DRY/STABLE AS SHOWN ON 00Z INL/GRB SDNGS (PWAT/KINX 0.49 INCH/2 AND 0.58 INCH/1 RESPECTIVELY). SO SKIES GENERALLY CLR ATTM. HOWEVER...SOME HI CLDS TO THE E OF AREA OF SHRA/TSRA OVER ND TO THE NE OF H85 WARM FNT/AHEAD OF H5 SHRTWV MOVING TOWARD THE NRN PLAINS ARE SPILLING INTO THE UPR LKS. ANOTHER AREA OF SHRA/TSRA NOTED TO THE S OVER SD/NB. MAIN FCST CONCERNS TDAY ARE RELATED TO FIRE WX. FOCUS FOR TNGT/SUN TURNS TO PCPN CHCS ASSOCIATED WITH H85 WARM FNT NOW IN THE NRN PLAINS. FOR TDAY...LATEST GFS/NAM SHOW CENTER OF HI PRES DRIFTING SLOWLY TO SE ONTARIO BY 00Z SUN. AREA OF LOWEST PWAT BLO 0.75 INCH PROGGED TO LINGER THRU THE DAY OVER THE E HALF. OTRW...00Z NAM F6 H85-7 FGEN FIELD CORRELATES WELL WITH OBSVD AREA OF SHRA/TSRA NOW IN ND. MODEL TENDS TO MOVE THIS FORCING MORE NE INTO NW ONTARIO. SO ALTHOUGH SOME HI CLD WL SPILL INTO THE WRN FA WHERE GUIDANCE SHOWS PWAT INCHING ABV 1 INCH...SKIES SHOULD BE MOSUNNY. MIXING TO H8 ON GFS/NAM FCST SDNGS YIELD HI TEMPS ARND 80-82 AWAY FM LK MODERATION. RETURN SLY FLOW ON THE BACK SIDE OF HI DRIFTING TO THE E WL TRANSPORT A BIT HIER LLVL MSTR INTO THE FA AS COMPARED TO YDAY. BUT SINCE LLVL DRY AIR HAS SPREAD FAIRLY FAR TO THE S...PREFER THE SOMEWHAT DRIER LLVLS OF THE GFS FCST SDNGS...WHICH WOULD SUG DWPTS WL MIX OUT AS LO AS 40 TO 45 AGAIN AWAY FM MODERATING FLOW OFF THE LK. T/TD OF 80/45 WOULD LOWER RH TO JUST BLO 30 PCT...AND T/TD OF 80/40 WOULD YIELD 25 PCT. EVEN IF THE LOWER RH VALUES VERIFY...EXPECTED WINDS APPEAR TO BE TOO LO FOR FIRE WX WATCH/WRNG. WL REISSUE WILDFIRE POTENTIAL STATEMENT TO HIGHLIGHT CONTINUED HIER RISK FOR WILDFIRES. NAM REMAINS THE WETTEST OF THE MODELS FOR TNGT SHOWING AN H85 SW WIND OF 40 KTS RETURNING QUITE A BIT OF LLVL MSTR. NAM QPF ALG THE WI BORDER FCST TO ARPCH 0.35 INCH. GFS IS STILL ONE OF THE DRIER SCENARIOS AND SHOWS NO QPF. CONSIDERING MODELS SHOW MAIN H85 WARM FNT LINGERING TO THE S AND NAM IS TRENDING WEAKER WITH THE IMPULSE/ LOWER WITH THE QPF...SEEMS THE GFS IS PROBABLY ON THE RIGHT TRACK. TEMPTED TO DISCOUNT THE NAM ALTOGETHER...BUT 00Z CNDN SHOWS QPF FARTHER N TO AREA OF SHARP H85-7 FGEN AT 12Z SUN ACRS THE NRN CWA AND MORE CONFLUENT H85 WINDS...ALSO WELL N OF THE SHARPER H85 FNT. RUC13 MODEL ALSO SHOWS PCPN SPREADING FARTHER TO THE N...SIMILAR TO AT LEAST SOME OF THE SREF MEMBERS. WITH H85 WARM FNT SO FAR TO THE S AND ANTECEDENT AIRMASS SO DRY...STILL LIKE THE CONSISTENT GFS FCST DESPITE THE OTHER MODEL SUPPORT FOR A SCENARIO SIMILAR TO THE NAM. HOWEVER...OPTED TO SPREAD LO CHC POPS FARTHER N IN THE 06Z-12Z TIMEFRAME THAN CURRENTLY FCST BASED ON THE ARRAY OF SUPPORT...AND USED CNDN MODEL SHARPER FGEN FCST AS THE LINE SO ADVANCE THE POP. WL END PCPN CHCS W-E ON SUN AS MODELS WHICH SUPPORT PCPN SHOW H85 FLOW VEERING TO MORE W IN THE WAKE OF TROF. SINCE THE GFS/NAM DIVERGE SO MUCH ON THE FCST TNGT...EACH PAINTS A VERY DIFFERENT PICTURE OF WHAT WL HAPPEN ON SUN. NOT SURPRISINGLY...GFS SHOWS A MUCH DRIER LLVL ENVIRONMENT OVER THE E WITH MORE SUNSHINE/DWPTS ARND 50 AT ERY THRU THE DAY. NAM HINTS DWPTS WOULD RISE INTO THE 60S WITH MORE CLD COVER. BOTH MODELS DO SHOW A CONSIDERABLE RISE IN LLVL MSTR OVER THE W IN ADVANCE OF SFC LO TRACKING ACRS CNTRL CNA. TENDED TOWARD THE GFS FCST SCENARIO GIVEN PREFERENCE FOR THE MORE MINIMAL MSTR TRANSPORT TO THE NE TNGT. COLD FROPA FCST SUN NGT ATTENDANT TO SFC LO TRACKING ACRS CNTRL CAN. NAM IS QUITE A BIT STRONGER WITH THIS LO...EXHIBITING A STRONGER WNW FLOW IN ITS WAKE/FASTER COLD FROPA. TENDED TOWARD A COMPROMISE UKMET SCENARIO...WHICH SUGS BNDRY WL REACH NR ERY-MNM AT 12Z MON. SINCE ANY DEEPER MSTR EXITS DURING THE DAY ON SUN WITH SYS RESPONSIBLE FOR PCPN CHCS LATE TNGT/SUN AND FROPA WL BE IN ABSENCE OF ANY DIURNAL HTG...EXPECT THE FROPA WL BE DRY DESPITE SOME FAIRLY STEEP H85-5 LAPSE RATES 7-7.5C/KM. UKMET SHOWS SFC COLD FNT EDGING PAST THE SCNTRL AND ERN COUNTIES EARLY ON MON MRNG AND GIVING WAY TO HI PRES BLDG IN FM ONTARIO. EXPECT TEMPS OVER THE INTERIOR SCNTRL AWAY FM LK SUP MODERATION IN DVLPG NE FLOW TO RISE WELL INTO THE 80S PER MIXING TO H75-8 ON GFS FCST SDNGS AND UKMET H85 TEMP FCST JUST BLO 20C. SINCE PREVIOUS FCST HAD A 30 POP OVER THE ENTIRE FA...MAINTAINED THOSE LO CHC POPS IN THE AFTN OVER THE SCNTRL GIVEN CONSIDERABLE SFC HTG AND POTENTIAL FOR LK BREEZE CNVGC...ESPECIALLY IF SFC COLD FNT HANGS UP JUST TO THE S. GUIDANCE PERSISTS IN SHOWING SFC LO APRCHG THE CNTRL GRT LKS MON NGT/TUE...WITH MOST MODELS TRENDING S OF THE GFS FCST...WHICH MAY BE SUFFERING CONVECTIVE FEEDBACK AND DVLPG LO TOO FAR TO THE N. MAINTAINED GOING CHC POPS DURING THIS TIME. THEN WENT DRY ON WED TO REFLECT RDG BLDG IN THE WAKE OF THIS SHRTWV. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE NEXT 24 HOURS WITH A FEW HIGH CLOUDS CROSSING THIS AFTERNOON AND MID CLOUDS INCREASING TONIGHT. THESE MID CLOUDS WILL BE ASSOCIATED WITH A WAVE OF LOW PRES AND PCPN OVER SOUTHERN MN AND WESTERN WI. SOME OF THIS PCPN MAY MOVE INTO THE FORECAST AREA AND TAF SITES AFTER 12Z SUN. EVEN THEN...MUCH OF THE PCPN SHOULD BE CONFINED TO THE SOUTH CENTRAL U.P. AND CHANCES ARE TOO LOW TO PUT INTO THE TAFS RIGHT NOW. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS ARE EXPECTED TO REMAIN BELOW 20 KT THROUGH THE PERIOD. HOWEVER...THERE ARE TWO PERIODS OF CONCERN WHERE THE WINDS COULD GET CLOSE TO 20 KT. THE FIRST IS LATE TONIGHT INTO SUN ON EASTERN LAKE SUPERIOR...DUE TO THE PRESSURE GRADIENT TIGHTENING BETWEEN A TROUGH ADVANCING EASTWARD ACROSS THE NORTHERN PLAINS AND HIGH PRESSURE MOVING TOWARDS NEW ENGLAND. THE SECOND IS ON ALL OF LAKE SUPERIOR LATE MON NIGHT INTO TUE MORNING AS A RESULT OF A LOW PRESSURE AREA MOVING FROM SOUTH DAKOTA ACROSS CENTRAL LAKE MICHIGAN...TIGHTENING THE PRESSURE GRADIENT BRIEFLY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...KC AVIATION...MICHELS MARINE...AJ mi AREA FORECAST DISCUSSION... CORRECTED CLIMATE SECTION NATIONAL WEATHER SERVICE RALEIGH NC 459 PM EDT SAT AUG 4 2007 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE OVER THE UPPER MIDWEST TODAY... IS EXPECTED TO MOVE SOUTHEAST AND CROSS THE CENTRAL APPALACHIANS AND MID ATLANTIC STATES LATE SUNDAY. A STRONG RIDGE ALOFT... CENTERED OVER NORTHERN MISSISSIPPI TODAY... WILL EXPAND EASTWARD OVER CENTRAL NORTH CAROLINA LATE SUNDAY INTO NEXT WEEK. THIS WILL BRING VERY DRY AND HOT CONDITIONS TO THE STATE. && .NEAR TERM /THROUGH TONIGHT/... SFC ANALYSIS THIS AFTERNOON SHOWED A 1016 MB AREA OF LOW PRESSURE LOCATED JUST OFFSHORE SC...WITH A SFC TROF AXIS EXTENDING NORTH INTO THE MID-ATLANTIC...AND FURTHER NORTH ALONG THE EAST COAST IN ASSOC/W LOW PRESSURE IN THE NORTHEAST STATES. DEWPOINTS ACROSS CENTRAL NC WERE IN THE LOWER 60S (NW PIEDMONT) TO THE UPPER 60S AND NEAR 70F ELSEWHERE. ALOFT...A TROUGH WAS ANALYZED AT 250MB OVER COASTAL NC/SC STRETCHING SOUTHWEST THROUGH SOUTHERN GA AND THE FLORIDA PANHANDLE. AN ANALYSIS OF WV IMAGERY AND RUC/NAM12 HEIGHT/VORT FIELDS DO NOT SHOW ANY VORT MAXES OR SHORTWAVES UPSTREAM OF THE AREA. MOISTURE AND INSTABILITY THIS AFTERNOON... THE 12Z GSO SOUNDING WAS SIMILAR TO FRIDAY`S SOUNDING...WITH A PWAT VALUE OF 1.26" AND SIMILAR MID-LEVEL TEMPS. THE SOUNDING SHOWED A BIT MORE DRY AIR IN THE MID-LEVELS THAN YESTERDAY. WITH TEMPS EXPECTED TO REACH INTO THE MID 90S THIS AFTERNOON...DEEP MIXING SHOULD ALLOW TO DEWPOINTS TO DROP ONCE AGAIN DURING PEAK HEATING. HOWEVER...GIVEN WHAT HAS HAPPENED THE PAST FEW DAYS...DEWPOINTS SHOULD REMAIN AT LEAST IN THE LOWER 60S ACROSS THE AREA TODAY...AND MID/UPPER 60S ALONG/EAST OF THE SFC TROF AXIS. THE 12Z GSO SOUNDING MODIFIED FOR A TEMP OF 93 AND A DEWPOINT OF 63 YIELDS A MEAN LAYER CAPE OF ABOUT 1000 J/KG THIS AFT/EVE. SFC AND UPPER LEVEL LIFT THIS AFTERNOON... A MORE WELL-DEFINED SFC TROF EXISTS ACROSS THE AREA THIS AFTERNOON WHEN COMPARED TO YESTERDAY. THE SFC CONVERGENCE ASSOC/W THE AXIS OF THIS FEATURE WILL PROVIDE A FOCUS FOR POTENTIAL CONVECTIVE DEVELOPMENT THIS AFTERNOON. ALOFT...AFTER REVIEWING WV IMAGERY AND RUC/NAM12 MODEL DATA...IT DOES NOT APPEAR THERE WILL BE ANY SIGNIFICANT UPPER LEVEL FEATURES TO BENEFIT CONVECTIVE DEVELOPMENT. RUC 250MB HEIGHT/DIVERGENCE FIELDS ACTUALLY SHOW SOME UPPER LEVEL CONVERGENCE...AND SOME MID-LEVEL SUBSIDENCE WARMING/DRYING OVER THE AREA IN THE WAKE OF THE SHORTWAVE TROF THAT PASSED TO THE EAST THIS MORNING...WHICH WILL ACT TO HELP SUPPRESS ACTIVITY. SUMMARY FOR THIS AFTERNOON AND TONIGHT... VERY ISOLATED SHOWER ACTIVITY DEVELOPED YESTERDAY AFTERNOON AROUND 18-19Z...AND WITH A SIMILAR THERMODYNAMIC SETUP TODAY AND A BETTER DEFINED SFC TROF OVER THE AREA THIS AFTERNOON TO ACT AS A FOCUS...WILL KEEP MENTION OF A SMALL (10%) CHANCE FOR ISOLATED SHOWERS THIS AFTERNOON. THE SFC TROF AXIS IS CURRENTLY LOCATED ALONG A LINE STRETCHING FROM LAURINBURG...TO CHAPEL HILL...TO HENDERSON. THIS IS WHERE ANY ISOLATED SHOWERS WOULD MOST LIKELY DEVELOP. SOME UPPER LEVEL CONVERGENCE AND MID-LEVEL SUBSIDENCE WARMING/DRYING OVER THE AREA IN THE WAKE OF THE 250MB SHORTWAVE PASSING TO THE EAST WILL HELP INHIBIT CONVECTIVE DEVELOPMENT...HOWEVER...THE POSITIVE FACTORS (1000-1250 J/KG OF MLCAPE AND SFC CONVERGENCE ASSOC/W TROF AXIS) SEEM TO OUTWEIGH THIS NEGATIVE FACTOR ENOUGH TO WARRANT CONTINUING A SMALL (10%) CHANCE OF SHOWERS FOR THE REMAINDER OF THIS AFTERNOON UNTIL SUNSET. OVERNIGHT...MOSTLY CLEAR SKIES ARE EXPECTED...ALTHOUGH UPPER LEVEL CLOUD COVER (CONVECTIVE DEBRIS FROM ACTIVITY IN IL/WI/IA) WILL BE ON THE INCREASE AS MOISTURE ALOFT RIDES NW FLOW AROUND THE EASTERN PERIPHERY OF THE RIDGE INTO THE MID-ATLANTIC. LOW TEMPS IN THE LOWER 70S. -VINCENT && .SHORT TERM /SUNDAY THROUGH MONDAY/... THE UPPER RIDGE IS EXPECTED TO BUILD OVER THE TENNESSEE AND LOWER MISSISSIPPI VALLEY REGIONS SUNDAY INTO MONDAY. DISTURBANCES IN THE NW FLOW A TOP THIS RIDGE WILL AFFECT AREAS MAINLY TO THE NORTH OF CENTRAL NC. ONE SUCH DISTURBANCE WAS LOCATED OVER THE UPPER MIDWEST SATURDAY AFTERNOON. THE 12Z/04 AUGUST NAM/ECMWF/UKMET ARE FAVORED OVER THE GFS IN DEPICTING A STRONGER SHORT WAVE TROUGH TO MOVE ACROSS WVA/VA ON SUNDAY AFTERNOON AND EVENING. THIS WOULD INCREASE THE CHANCE OF DIURNAL CONVECTION JUST TO OUR NORTH SUNDAY AFTERNOON AND EVENING. MOST MODELS DO DEPICT A PIEDMONT SURFACE TROUGH DURING PEAK HEATING TO HELP WITH A LOW LEVEL FOCUS FOR CONVERGENCE. EVEN THOUGH THERE WILL BE PLENTY OF LOW LEVEL INSTABILITY ALONG AND EAST OF THE SURFACE TROUGH... IT STILL APPEARS THAT MOST OF THE UPPER SUPPORT WILL REMAIN NORTH OF CENTRAL NC. FOR NOW... WE WILL KEEP SLIGHT CHANCE POP FOR THE NORTHERN PIEDMONT AND COASTAL PLAIN TO ACCOUNT FOR THIS FEATURE SUNDAY AFTERNOON AND EVENING. MAX TEMPS SHOULD BE COMPARABLE TO TODAY WITH SIMILAR LOW LEVEL THICKNESSES. EXPECT HIGHS OF 93-98 UNDER MOSTLY SUNNY SKIES. THE UPPER SHORT WAVE IS EXPECTED TO PASS OFF TO OUR NE SUNDAY NIGHT WITH THE RIDGE EXPECTED TO BUILD IN FROM THE SW. EXPECT MOSTLY CLEAR SKIES SUNDAY NIGHT WITH LOWS 70-75. MOSTLY SUNNY MONDAY WITH HIGHS IN THE MID 90S. THE GRIDS WILL SHOW THE TYPICAL CLIMO DISTRIBUTION WITH MAX TEMPS IN THE NW ABOUT 3-4 DEGREES LOWER THAN THE SANDHILLS. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE OVERALL PATTERN ALOFT IS EXPECTED TO FEATURE A BUILDING UPPER RIDGE CENTERED FROM THE MID MISSISSIPPI VALLEY REGION TO THE TENNESSEE VALLEY AND SOUTHEASTERN STATES. SUBSIDENCE ASSOCIATED WITH THIS STRENGTHENING RIDGE AND THE POSITION OF THE RIDGE FAVORS VERY DRY AND HOT WEATHER FOR CENTRAL NC. ORGANIZED CONVECTION IS EXPECTED TO REMAIN NORTH OF CENTRAL NC ALONG THE SOUTHERN EDGE OF THE WESTERLIES A TOP THE UPPER RIDGE. NO POP WILL BE ADVERTISED. THE MAIN FOCUS FOR CENTRAL NC WILL BE THE VERY DRY AND HOT WEATHER WITH WORSENING DROUGHT CONDITIONS WITH THE POTENTIAL FOR SOME DAILY RECORD HIGHS. THE VERY DRY SOILS IN PLACE UNDER THIS RIDGE SUPPORT AT LEAST SOME RECORD HIGHS AROUND MID WEEK. SEE LIST OF RECORD HIGHS IN THE CLIMATE SECTION. THE HOTTEST WEATHER SHOULD BE TUESDAY INTO THURSDAY WHEN HIGHS SHOULD BE ABLE TO REACH 100... ESPECIALLY OVER PORTIONS OF THE SANDHILLS. THE TYPICAL DIURNAL TREND OF HIGH DEW POINTS AT NIGHT INTO THE EARLY MORNING... WITH SOME MIXING OF DRIER AIR DOWN TO THE SURFACE FROM THE MID LAYERS IN THE AFTERNOON IS EXPECTED. THE HIGHEST DEW POINTS (MID 70S) SHOULD BE FOUND ESPECIALLY OVER THE EASTERN PIEDMONT INTO THE COASTAL PLAIN AT NIGHT INTO THE MID MORNING HOURS... MIXING OUT TO UPPER 60S AT PEAK HEATING. THIS WOULD YIELD HEAT INDICES APPROACHING 105. LOWS AT NIGHT SHOULD BE ONLY IN THE LOWER TO MID 70S. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... EXCEPT FOR PERIODS OF MVFR CONDS IN HAZE...AND PRIMARILY AT THE INT/GSO TAF SITES...VFR CONDS ARE FORECAST THROUGH THE TAF PERIOD. FEW OR SCT070 DIURNAL CU WILL ABATE BY SUNSET...WITH SCT UPPER LEVEL CLOUD COVER ADVECTING INTO THE AREA OVERNIGHT FROM THE NORTHWEST. LIGHT/VARIABLE WINDS THROUGH THE REMAINDER OF THE EVENING AND OVERNIGHT HOURS...WITH LIGHT SSW WINDS EXPECTED SUNDAY. NORTHERN TAF SITES MAY SEE A SLIGHT CHANCE FOR A SHOWER OR STORM AND ASSOC LOW CIGS/VIS SUN AFT/EVE IF REMNANT MCS ACTIVITY IS ABLE TO RIDE NW FLOW ALOFT AROUND THE EASTERN PERIPHERY OF THE RIDGE INTO NC...THIS IS A LONG SHOT THOUGH AND MOST ACTIVITY WILL LIKELY REMAIN NORTH OF THE AREA IN VA. VFR CONDS ARE GENERALLY EXPECTED THROUGH THE MIDDLE OF NEXT WEEK AS A STRONG UPPER LEVEL RIDGE BUILDS OVER THE MID-ATLANTIC. A CHANCE OF DIURNAL CONVECTION MAY BE POSSIBLE TOWARDS THE LATTER HALF OF THE UPCOMING WEEK IF THE UPPER RIDGE BEGINS TO RETREAT WEST AS THE LATEST GFS RUN IS INDICATING...OTHERWISE...NO SIGNIFICANT WEATHER RESTRICTIONS (OTHER THAN MVFR HZ OR MVFR PRE-DAWN FOG) ARE EXPECTED DURING THE PERIOD. -VINCENT && .CLIMATE... THE FORECAST OF THE EXPANSION OF THE LARGE UPPER RIDGE EASTWARD FROM THE PLAINS TOWARD THE SOUTHERN APPALACHIANS THIS WEEK GENERALLY MEANS VERY DRY AND HOT WEATHER FOR CENTRAL NORTH CAROLINA. SOME DAILY RECORD HIGHS MAY BE IN JEOPARDY ESPECIALLY TUESDAY THROUGH FRIDAY (AUGUST 6-9). SEE THE LIST BELOW. IN ADDITION... THE DROUGHT WILL CONTINUE TO WORSEN. DAILY HIGHS IN THE 95-100 RANGE WILL COMBINE WITH LITTLE OR NO RAINFALL AND VERY HIGH EVAPORATION RATES TO EXACERBATE THE CURRENT DROUGHT. DAILY RECORD HIGHS FOR AUGUST 6-9 INCLUDE: AUGUST 6... AUGUST 7... AUGUST 8... AUGUST 9 RALEIGH-DURHAM... 97 (1999)...100(1999)...101 (1999)...100 (2001) GREENSBORO........97 (1977)... 99(1977)... 96 (1980)... 99 (1930) && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...VINCENT SHORT TERM...BADGETT LONG TERM...BADGETT AVIATION...VINCENT CLIMATE...BADGETT nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 303 PM EDT SAT AUG 4 2007 .SYNOPSIS... A STATIONARY FRONT ALONG THE OHIO RIVER VALLEY IS FORECAST TO LIFT NORTHEAST AS A WARM FRONT OVERNIGHT...CROSSING THE REGION ON SUNDAY. THIS FRONT WILL BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS...ESPECIALLY ON SUNDAY. A COLD FRONT WILL APPROACH THE REGION ON MONDAY...WHICH WILL KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FORECAST. && .NEAR TERM /THROUGH TONIGHT/... FORECAST DILEMMA OVER THE NEXT 12-15 HOURS WILL BE THE AMOUNT OF CONVECTION THE REGION WILL RECEIVE. WILL USE LATEST RUC40 AND 09Z SREF ENSEMBLE MEAN FOR THE IMMEDIATE NEAR TERM FORECAST. A FRONTAL BOUNDARY EXTENDED FROM SERN IOWA...SE INTO W CNTRL IL...SWRN INDIANA...THEN ALONG AND NEAR THE OHIO RIVER VALLEY TOWARD THE MID ATLANTIC REGION. THIS FRONTAL BOUNDARY WILL REMAIN RELATIVELY QUASI-STATIONARY THROUGH 06Z...THEN IT WILL BEGIN TO LIFT NE AS A WARM FRONT. MOSAIC RADAR AND VISIBLE SATELLITE IMAGERY WAS SHOWING ISOLATED CONVECTION ALONG AND SE OF THE FRONTAL BOUNDARY ACRS SE OHIO...NRN WEST VA...THEN WESTWARD ALONG THE OHIO RIVER VLY ACRS FAR SRN OHIO... NRN KY AND SRN INDIANA. MOST OF THIS CONVECTION IS EXPECTED TO DIE OUT AFTER SUNSET AS IT IS BASICALLY DIURNALLY DRIVEN IN THE WARM AND UNSTABLE AIRMASS. FARTHER TO THE NW...SCATTERED CONVECTION WAS NOTED ACRS CNTRL INDIANA. THIS CONVECTION SHOULD PROPAGATE SE INTO THE WHITEWATER/MIAMI RIVER VLY LATE THIS AFTN AND THIS EVENING. THIS CONVECTION SHOULD ALSO DIMINISH SOMETIME THIS EVENING. CONVECTION FURTHER TO THE WEST...NEAR SE IOWA...IS EXPECTED TO AFFECT W CNTRL ILLINOIS AND SWRN INDIANA THIS EVENING. ALL IN ALL...WILL EMPLOY 20 TO 30 POPS IN THE AFFECTED REGIONS THROUGH 06Z. THEREAFTER...ANOTHER S/WV WILL PIVOT TOWARD THE IOWA/NE NEBRASKA REGION. THIS FEATURE WILL COMBINE WITH AN INCREASING MOIST 925 MB-850 MB LOW LVL JET. THIS WILL LIKELY RESULT IN AN MCS ACRS THE IOWA...WRN WISCONSIN...SWRN MICHIGAN...NW INDIANA AND NRN ILLINOIS REGION BETWEEN 06Z AND 09Z. IF THE CONVECTION CONGEALS INTO A SIZABLE MCS...THE 850 MB-300 MB THERMAL WIND SUGGESTS THAT IT WILL PROPAGATE FROM NNW TO A SSE DIRECTION RIGHT INTO OUR FCST REGION. FOR NOW...WILL INCREASE POPS TO HIGH CHC ACRS THE WEST TOWARD MORNING. OVERNIGHT LOWS WILL RANGE FROM THE MID 60S NORTH TO THE LOWER 70S SOUTH. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... ON SUNDAY...ELEVATED CONVECTION SHOULD BE ONGOING AND WILL CONTINUE TO SPREAD SE INTO THE FCST AREA. HAVE FOLLOWED CLOSE TO THE 09Z SREF ENSEMBLE SOLUTION AND THUS WILL MAINTAIN LIKELY POPS FOR THE NE TWO THIRDS OF THE FCST AREA...WITH CHC POPS FAR SOUTH AND WEST. DUE TO THE POTENTIAL FOR PCPN AND CONSIDERABLE CLOUD COVER...AND A WARM FRONT THAT MAY BE SLOWED BECAUSE OF THE RAIN COOLED AIR...HAVE CONTOURED HIGH TEMPERATURES FROM NEAR 80 NORTHEAST TO THE LOWER 90S SOUTHWEST. IT COULD END UP BEING MUCH COOLER IF CLOUDS AND PCPN LINGER TOO LONG INTO MID AFTERNOON. THIS WILL BE SOMETHING FOR THE MID SHIFT TO CONSIDER AND THE DAY SHIFT ON SUNDAY. FOR SUNDAY NIGHT INTO MONDAY...THE AFOREMENTIONED WARM FRONT WILL LIFT NE OF THE REGION...FOLLOWED BY AN APCHING COLD FRONT FROM THE NORTHWEST ON MONDAY. OPERATIONAL 12Z NAM AND 12Z GFS CONTINUE TO PUSH A COLD FRONT INTO NRN INDIANA AND NRN OHIO ON MONDAY...WHILE ENSEMBLE MEANS KEEP THE FRONT A LITTLE FARTHER TO THE NORTH. IN ANY CASE...WILL MAINTAIN LOW CHC POPS ACRS THE REGION DUE TO THE PROXIMITY OF THE FRONT AND AN UNSTABLE AIRMASS. DEWPOINTS WILL INCREASE INTO THE LOWER 70S ON MONDAY. WITH HIGH TEMPERATURES FCST TO PUSH INTO THE LOWER TO MID 90S...HEAT INDEX VALUES WILL LIKELY APPROACH THE 100 DEGREE MARK. WILL NOT ISSUE ANY HEAT ADVISORIES YET AS THIS IS IN THE FOURTH PERIOD ATTM...BUT MIDNIGHT SHIFT MAY HAVE TO CONSIDER IT. FOR THE REMAINDER OF THE SHORT TERM...MONDAY NIGHT THROUGH TUESDAY NIGHT...THE COLD FRONT ON MONDAY WILL LIFT NE AS A WARM FRONT MONDAY NIGHT...LEAVING THE REGION IN A HOT...MOIST AIRMASS THROUGH THE PERIOD. WILL HAVE LOW CHC/S POPS THROUGH THE PERIOD...MAINLY DURING THE AFTN/EVENING HOURS. OVERNIGHT LOWS WILL GENERALLY FALL INTO THE LOWER 70S WITH HIGHS IN THE LOWER TO MID 90S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... UPPER RIDGE IS PROGGED TO REMAIN ENTRENCHED ACROSS MOST OF THE CONUS. THIS WILL ALLOW HOT WEATHER TO PERSIST. A SERIES OF SHORT WAVES WILL RIDE OVER THE TOP OF THE RIDGE AND EFFECT THE OHIO VALLEY REGION DURING THE MID AND LATER PART OF THE WEEK. TIMING AND CHANCE OF PRECIPITATION WILL BE DIFFICULT TO FORECAST. AT THE SURFACE...A WARM FRONT WILL EFFECT THE OHIO VALLEY REGION WED THROUGH THURS PRODUCING WIDELY SCATTERED/SCATTERED SHOWERS AND THUNDERSTORMS. A FRONT WILL MOVE THROUGH THE AREA FRI/FRI NIGHT SO SLGT CHANCE/CHANCE POPS CONTINUE IN FORECAST THROUGH FRIDAY. SATURDAY WILL BE DRY. EXPECT AFTERNOON TEMPERATURES MAINLY IN THE 90S EACH DAY. SATURDAYS HIGH TEMPERATURES WILL COOL A FEW DEGREES BEHIND THE FRONT. CONTINUED CONSERVATIVE AND KEPT CLOSE TO HPC GUIDANCE IN LOW TO MID 90S...MID TO UPPER 80S NORTH BY SAT. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... DRIER AIR WAS PUSHING IN BEHIND A FRONTAL BNDRY ACROSS SOUTHERN OHIO AND INDIANA. CIGS AND VSBYS WILL BE VFR. SCT CU WILL DEVELOP AFTER 15Z WITH ISOLD CB 19Z-02Z. WINDS WILL BE VARIABLE LESS THAN 10 KTS...DEPENDING ON PROXIMITY TO THE BNDRY...THEN EVENTUALLY TURNING SE AFTER 06Z. HIGH CLOUDS WILL DRIFT INTO REGION THROUGH 00Z...WITH MID CLOUDS 00Z-03Z. THE NAM REMAINS SLOWER AND FURTHER NORTH WITH A S/W MOVING ALONG THE BNDRY AND ASSOCIATED PCPN. LOOKING AT RUN TO RUN VARIABILITY AND MODEL DISAGREEMENT...THERE IS STILL CONSIDERABLE UNCERTAINTY...BUT IT APPEARS THAT STORMS ARE POSSIBLE AFTER 06Z AND HAVE ADDED VCSH WITH CB 06Z-08Z WEST TO EAST. OUTLOOK...THUNDERSTORMS ARE POSSIBLE SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...PARKER AVIATION...PARKER oh AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 145 PM MDT SAT AUG 4 2007 .DISCUSSION...VIS SAT SHOWS THE LOW LEVEL CLOUD DECK HAS ERODED OVER MOST OF THE SD PLAINS...THOUGH THE DECK IS PERSISTING ACROSS SOUTH CENTRAL SD. CU FIELD DEVELOPED QUICKLY LATE THIS MORNING OVER THE BLACK HILLS AND NE WY. SURFACE OBS SHOW A SURFACE TROUGH/DRY LINE EXTENDING ACROSS ACROSS THE WESTERN SD BORDER WITH DEWPOINTS IN MID TO UPPER 60S ON THE MOIST SIDE OF THE BOUNDARY. THE RUC AND NAM BOTH SHOW CAPE VALUES OVER 1000 J/KG ALONG THE DRY LINE...WITH THE HILLS REACHING OVER 2000 J/KG. THE CAP WILL CONTINUE TO ERODE OVER THE AREA...WHILE AREAS FARTHER EAST THAT HAD MORE CLOUD COVER THIS MORNING WILL REMAIN CAPPED THE REST OF THE DAY. HAVE INCREASED POPS OVER THE HILLS TO 30...AND ADDED 20 POPS ACROSS NE WY AND WRN SD. THERE IS ENOUGH SHEAR FOR SOME STORMS TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS POSSIBLE. WEAK UPPER RIDGE WILL REMAIN ACROSS THE CWA THE NEXT COUPLE DAYS. SEVERAL SHORTWAVES ARE PROGGED TO PUSH THROUGH KEEPING AN ACTIVE PATTERN SUNDAY AND MONDAY. A SURFACE TROUGH WILL REMAIN ACROSS THE CWA AIDING WITH CONVECTIVE INITIATION TOMORROW. INSTABILITY IS NOT LACKING WITH CAPE VALUES RANGING FROM 1000 J/KG ACROSS THE PLAINS TO 2000 TO 3000 J/KG OVER THE HILLS. WITH A JET STREAK ACROSS ND ENHANCING VERTICAL SHEAR...COULD SEE SOME STORMS BECOMING SEVERE AGAIN TOMORROW. EXTENDED...A FLAT UPPER RIDGE WILL DOMINATE THE WEATHER THROUGH MOST OF NEXT WEEK AS A SERIES OF WEAK DISTURBANCES CROSS THE AREA...CREATING A SLIGHT CHANCE OF THUNDERSTORMS OVER VARIOUS PORTIONS OF THE FORECAST AREA EACH DAY. HIGH TEMPERATURES WILL BE WELL INTO THE 90S ON THE PLAINS...WITH SOME 80S IN THE BLACK HILLS. && .AVIATION...ISOLD/SCT TSTMS EXPECTED ACROSS THE AREA THIS EVENING WITH A CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN NORTH DAKOTA OVERNIGHT. VFR CONDITIONS EXPECTED OVERNIGHT. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ CALDERON/RICHARDS sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 1100 AM MDT SAT AUG 4 2007 .DISCUSSION...SURFACE ANALYSIS SHOWS A SURFACE TROUGH EXTENDING FROM ERN MT DOWN THROUGH ERN WY. WATER VAPOR SHOWING A SERIES OF SUBTLE SHORTWAVES MOVING ACROSS NRN WYOMING AND SRN IDAHO. VIS SAT SHOWING EXTENSIVE STRATUS DECK ACROSS THE SD PLAINS...WHICH IS SLOWLY DISSIPATING AT THIS TIME. LATEST RUC AND NAM SHOWS A GOOD AMOUNT OF INSTABILITY ACROSS NE WY AND ESPECIALLY THE BLACK HILLS THIS AFTERNOON W/ CAPE VALUES OVER 2000 J/KG. WITH THE PRESENT LOW LEVEL MOISTURE...FORECAST PROFILES SHOW THE CAP ERODING BY EARLY AFTERNOON. SAT SHOWING CU DECK QUICKLY DEVELOPING OVER THE HILLS ATTM...SO HAVE ADDED 30 POPS FOR THIS AFTERNOON AND EVENING AND 20 POPS ALONG THE WY-MT/SD BORDER. THERE IS ENOUGH SHEAR FOR A FEW STORMS TO BECOME SEVERE...WITH HAIL AND WIND BOTH BEING THREATS. && .PREVIOUS DISCUSSION [310 AM MDT]...CURRENT SURFACE ANALYSIS PLACES PRIMARY LOW PRESSURE CENTER OVER SOUTHWESTERN SASKATCHEWAN...WITH SECONDARY LOW MOVING INTO SOUTH CENTRAL SOUTH DAKOTA. UPPER LEVEL ANALYSIS INDICATING ZONAL FLOW OVER THE AREA. CONVECTIVE ACTIVITY HAS GENERALLY MOVED EAST OF THE AREA. IN ITS WAKE...BROAD AREA OF STRATUS WITH AREAS OF FOG HAVE DEVELOPED OVER MUCH OF WESTERN INTO CENTRAL SOUTH DAKOTA. FOR TODAY...LOW STRATUS/FOG SHOULD DISSIPATE THIS MORNING GIVING WAY TO PARTLY CLOUDY SKIES BY THE NOON HOUR. ANOTHER WARM DAY IS ON TAP AS FLAT UPPER RIDGE REMAINS OVER THE REGION. THIS AFTERNOON INTO TONIGHT...A WEAK UPPER DISTURBANCE PUSHING IN FROM THE WEST MAY RESULT IN ISOLATED THUNDERSTORMS DEVELOPING OVER NE WYO PUSHING INTO WRN SD IN THE EVENING. SUNDAY IS EXPECTED TO BE SLIGHTLY WARMER WITH HIGHS GENERALLY IN THE 90S. A MORE VIGOROUS WAVE IS EXPECTED TO PUSH INTO THE AREA BY THE EVENING WHEN MODELS ARE INDICATING CAPE VALUES OF 1000-2000 J/KG OVER THE EASTERN CWFA. WITH THIS...HAVE UPPED POPS SLIGHTLY FROM THE BLACK HILLS EASTWARD. PRECIP CHANCES CONTINUE INTO MONDAY AS A WEAK FRONTAL BOUNDARY SLIDES THROUGH THE AREA. EXTENDED...A FLAT UPPER RIDGE WILL DOMINATE THE WEATHER NEXT WEEK. HAVE LEFT THE FORECAST DRY FOR NOW AS THERE ARE NO DISTINCT WAVES MOVING THROUGH...WITH A DECENT CAP IN PLACE. TEMPERATURES WILL BE 5-10F ABOVE NORMAL. && .AVIATION...IFR/MVFR CIGS OVER WESTERN AND CENTRAL SOUTH DAKOTA WILL CONTINUE TO IMPROVE...WITH VFR CONDITIONS EXPECTED BY EARLY AFTERNOON. A FEW THUNDERSTORMS ARE POSSIBLE OVER EASTERN WYOMING...THE NEBRASKA PANHANDLE...SOUTHEASTERN MONTANA...SOUTHWESTERN NORTH DAKOTA AND WESTERN SOUTH DAKOTA DURING THE AFTERNOON AND EVENING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ CALDERON/RICHARDS sd