AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 1001 PM EDT MON AUG 15 2005 .SYNOPSIS...ANOTHER ACTIVE EVENING ACROSS THE CWA AS MID LVL DIFFERENTIAL VORTICITY ADVECTION AROUND AN UPPER LOW OVER THE FL BIG BEND ENHANCED SEABREEZE AND OUTFLOW BOUNDARY LOW LVL CONVERGENCE. STORMS IGNITED ALONG THE HWY 301 AND HWY 1 CORRIDOR IN N FL AND SE GA AROUND 6 PM WITH EXCESSIVE LIGHTNING THE MAIN HAZARD. ISOLD TS CONTINUE THIS HOUR WHERE LOW LVL CONVERGENCE REMAINS IN EASTERN MARION COUNTY AND ACROSS OUR WESTERN SUWANNEE RIVER VALLEY ZONES IN FL. THE RUC40 850-500 MB DPVA SHOWS ENERGY ROTATING NWD THROUGH MIDNIGHT AS SUBSIDENCE BUILDS IN FROM THE ATLANTIC. THUS EXPECT CURRENT CONVECTION WILL SLOWLY WEAKEN WITH A FEW ISOLD SHRA POSSIBLE ELSEWHERE UNTIL MIDNIGHT. HAVE ADJUSTED POP AND WX GRIDS TO REFLECT DECREASING P0P TREND. PATCHY TO AREAS OF FOG ARE EXPECTED OVERNIGHT AS SKIES CLEAR AND WINDS DECOUPLE. ALSO NOTED THAT KJAX WAS NEAR FORECASTED MIN AT 9 PM...LIKELY A REMNANT COLD POOL/MESOHIGH IN THE WAKE OF THIS EVENINGS CONVECTION. ADJUSTED MINS DOWN SLIGHTLY ONLY BY A DEG OR SO ACROSS THE INTERIOR. && .MARINE...SSW 10-12 KTS PREVAIL OVER THE WATERS WITH SEAS ~2 FT. FLOW WILL GRADUALLY VEER TO THE S AS HIGH PRESSURE BUILDS NWD FROM SOUTH FL. MAGNITUDES EXPECTED NEAR 10 KTS OVERNIGHT. CURRENT CWF LOOKS ON TRACK. && .PRELIMINARY POINT TEMPS/POPS... AMG 74 96 74 95 / 30 40 40 50 SSI 78 93 78 94 / 20 30 30 40 JAX 74 96 75 96 / 30 40 40 50 SGJ 76 93 77 94 / 20 30 30 30 GNV 73 95 74 95 / 30 40 30 30 OCF 73 95 74 94 / 30 40 30 30 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. MARINE...NONE. && $$ ENYEDI fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 855 PM EDT MON AUG 15 2005 .DISCUSSION...WHAT A BUSY EVENING THIS HAS BEEN WITH NUMEROUS SPECIAL WEATHER STATEMENTS ISSUED AND A FEW SEVERE THUNDERSTORM WARNINGS AS WELL IN SOUTHEAST ALABAMA. VISIBLE SATELLITE IMAGE SHOWS A COUNTERCLOCKWISE ROTATION ACROSS OUR FORECAST AREA WITH CENTER OF CIRCULATION APPEARING OVER SOUTHWESTERN GEORGIA. EXAMINATION OF THE RUC MODEL SHOWS A STRING OF VORTICITY MAXIMA FROM PENSACOLA TO DOTHAN TO WAYCROSS. MSAS ALSO REVEALS A WEAK SURFACE LOW NEAR ALBANY GEORGIA. RADAR TRENDS HAVE BEEN DIMINISHING OVER SOUTHEAST ALABAMA BUT STARTING TO PICK UP OVER GEORGIA. THIS ACTIVITY IS ALSO MOVING TOWARD SOUTHEAST ALABAMA. MAIN THREATS FROM THESE STORMS WILL BE GUSTY WINDS AND FREQUENT CLOUD TO GROUND LIGHTNING. EVENING SOUNDING FROM KTAE SHOWS A FREEZING LEVEL AROUND 16KFT AND THIS WILL LIKELY PRECLUDE ANY HAIL THREAT. THE CURRENT CONFIGURATION OF POPS IN THE EVENING FORECAST WILL BE REALIGNED IN THE FIRST SIX HOURS (00Z TO 06Z) TO MATCH BETTER WITH CURRENT RADAR TRENDS. THIS WILL TRANSLATE TO 50 POPS OVER GA AND AL...40 POPS OVER PANHANDLE FLORIDA WITH 30 POPS ELSEWHERE. THINK THAT THERE MAY BE SOME OF THESE SHOWERS AND THUNDERSTORMS REMAINING PAST MIDNIGHT SO WILL WORD THE TONIGHT PERIOD "SHOWERS AND THUNDERSTORMS DIMINISHING LATE IN THE NIGHT." TEMPS ALREADY COOLER THAN FORECAST MINS IN ALABAMA DUE TO THE RAIN. THE PANHANDLE OF FLORIDA LOOKS TO BE A LITTLE WARM SO WILL LOWER TEMPS WEST OF THE APALACHICOLA RIVER IN FLORIDA. REST OF THE FORECAST IS IN GOOD SHAPE. WILL ISSUE ZONES AND OTHER PRODUCTS SHORTLY. HAVE A GREAT NIGHT! && .AVIATION...SCT SHWRS/TSRA ACTIVITY IS ON A DIMINISHING TREND ACROSS THE FL PANHANDLE AND BIG BEND...HOWEVER ACTIVITY IS STILL ONGOING ACROSS SE AL AND SW GA. KEPT TEMPO GROUPS IN FOR MOST SITES THROUGH 02Z...BUT MAY EXTEND IT A FEW HOURS FOR DHN AND ABY SITES IF ACTIVITY IS SLOW TO DISSIPATE. EXPECT AREAS OF REDUCED VSBYS TO NEAR MVFR DURING THE EARLY MORNING HOURS...ESPECIALLY NEAR VLD. && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. && $$ PUBLIC/MARINE-GODSEY AVIATION-SHAFER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 1030 AM EDT MON AUG 15 2005 ...TRANSITIONING TOWARD MUCH LOWER RAIN CHANCES NEXT FEW DAYS... .DISCUSSION... DATA FROM WEATHER BALLOON THIS MORNING SHOWS DRIER AIR HAS BEGUN TO ADVECT FROM THE EAST AND LOW LEVEL RIDGE AXIS HAS LIFTED A BIT FARTHER NORTH TOWARD CENTRAL FLORIDA. PWATS ARE DOWN TO 1.73" AND EXPECT TO SEE AN EARLIER EAST COAST SEA BREEZE THAN PREVIOUS DAYS. WATER VAPOR IMAGERY OVERLAID WITH RUC40 ANALYSIS SHOWS VORT AXIS SHIFTING NORTHWEST INTO THE EASTERN GULF OF MEXICO. IN ITS WAKE... ATM IS BECOMING INCREASINGLY SUPPRESSED AS STRONG UPPER HIGH BUILDS IN FROM THE EAST. MUCH DRIER AIR (IN THE MID LEVELS) CAN BE SEEN APPROACHING THE BAHAMAS AND THIS IS FORECAST TO OVERSPREAD FLORIDA NEXT FEW DAYS. RAIN CHANCES ARE LOWEST ALONG THE IMMEDIATE COAST IN MARTIN AND ST LUCIE COUNTY (15%) AND HIGHEST OVER INTERIOR COUNTIES (30%). STEERING FLOW REMAINS VERY LIGHT OUT OF THE S/SE SO SLOW MOVING STORMS MAY PRODUCE PROLONGED HEAVY RAINFALL IN A FEW AREAS BUT AS MENTIONED COVERAGE WILL NOT BE HIGH. H5 TEMPS STILL RATHER COOL (-7.7C) SO ISOLATED STRONG STORMS POSSIBLE INVOF BOUNDARY COLLISIONS LATE THIS AFTN OVER THE INTERIOR. BUT TREND IS TOWARD WARMING AND STABILIZING ALOFT. FORECAST FOR MID 90S INTERIOR AND LOW 90S COAST LOOKS GOOD. HAVE UPDATED GRAPHICAL WIND PRODUCTS FOR TODAY AND WILL UPLOAD TO WEB PAGE SHORTLY. && .MARINE...RIDGE AXIS ACROSS SRN LEG OF CSTL WATERS THIS MORNING WITH SW WIND NR 5 KTS AT BUOY 41009 AT 8 AM. FOR MARINE UPDATE...EXPECT WINDS TO BECOME ONSHORE AT 5 TO 10 KNOTS THIS AFTN AS EAST COAST SEA BREEZE DEVELOPS. OTHERWISE LITTLE CHANGE TO FCST WITH A 2-3 FT SWELL EXPECTED. && .AVIATION...LOWER COVERAGE OF AFTN STORMS EXPECTED TODAY. TAF SITES MCO AND SFB HAVE PROB30 FOR LATE AFTN CIG/VSBY REDUCTIONS IN TSRA. WILL HAVE TO DECIDE TO REMOVE THIS OR GO TEMPO AT 18Z TAF ISSUANCE AND AM LEANING TOWARD REMOVING IT. PROBABILITY OF RESTRICTIONS AT COASTAL TAFS (DAB/MLB/VRB) ARE TOO LOW TO INCLUDE AT THIS TIME. && .RADAR...RESET THE STORM TOTAL PRECIP PRODUCT AT 12Z. && NOAA GOES-N WEATHER SATELLITE IS SCHEDULED TO BE LAUNCHED FROM CAPE CANAVERAL THIS EVENING. LAUNCH WINDOW IS 6:32 TO 7:06 PM. THE GEOSTATIONARY OPERATIONAL ENVIRONMENTAL SATELLITES OPERATE IN GEOSYNCHRONOUS ORBIT 22,300 MILES ABOVE THE SURFACE. BY REMAINING OVER A FIXED LOCATION...THEY PROVIDE INVALUABLE ASSISTANCE TO METEOROLOGISTS 24 HOURS A DAY IN FORECASTING AND TRACKING SEVERE WEATHER (AND THE CONDITIONS OR "TRIGGERS" THAT CAN PRODUCE SEVERE WEATHER) INCLUDING HURRICANES...FLOODING...TORNADOES AND HAILSTORMS. && .MLB WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KELLY/VOLKMER fl WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL 920 AM EDT MON AUG 15 2005 .DISCUSSION...GENERAL RIDGING ALOFT CONTINUES TO DOMINATE MUCH OF THE AREA...HOWEVER...WATER VAPOR STLT AND RUC PLACES WEAK LOW OVER THE GULF WATERS TO THE WEST. MEANWHILE...THE RUC/MSAS/SFC OBS SUPPORT LOCATING A SURFACE RIDGE FROM THE ATLANTIC WESTWARD WITH AN AXIS ALONG THE FL/GA/AL STATE LINE. THIS IS PROVIDING A LIGHT EASTERLY FLOW ACROSS THE SOUTHERN CWFA WHILE THE NORTH END ...CLOSER TO THE RIDGE AXIS...HAS CALM OR MOSTLY VARIABLE VERY LIGHT WINDS. THE 12Z TBW RAOB SHOWS A PWAT OF ~1.75 INCHES WITH -8.7 AT H5. VERY SIMILAR TO YESTERDAY. SO...ANOTHER AFTERNOON OF SCATTERED TSTMS/ 40 POPS/ ALONG WITH A WEAK SEA BREEZE. CURRENT FORECAST HANDLES THIS WELL WITH NO UPDATE NEEDED. HOWEVER WILL RE-ISSUE THE GRAPHIC HWO AND BUMP UP THE LIGHTING ACROSS MOST OF THE INTERIOR AND SOUTH. && .MARINE...NO CONCERNS ON THE COASTAL WATERS UNLESS YOU ARE NEAR OR IN A TSTM. THE LATE NIGHT CONVECTION HAS WEAKENED AND NW OF THE AREA. HOWEVER ISOLATED RW/TSTMS CAN BE EXPECTED FROM NOON TIME INTO THE EVENING WITH SLIGHTLY MORE COVERAGE ALONG THE SHORE. ONLY CHANGE TO THE CURRENT FOREST WILL BE ADJUST FIRST PERIOD WORDING FOR THE NORTH ZONE TO: VARIABLE BECOMING WEST. OTHERWISE NO CHANGE WITH THE FORECAST OUT BY 1015 AM. && .TBW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ RKR fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 957 AM MDT MON AUG 15 2005 .UPDATE...A LEE TROF DEVELOPING OVER COLORADO IS HELPING KICK WIND SPEED UP INTO THE 10 TO 15 MPH RANGE...STILL LIGHT BY LOCAL STANDARDS. TEMPERATURES ARE ON TRACK TO REACH THE LOWER 80S AT MOST LOCATIONS. LOW CLOUDS AND STRATUS SURROUND THE SOUTHERN AND WESTERN FORECAST AREA...AND SOME OF THIS WILL SPREAD NORTH TOWARD I-70 AS 850MB FLOW TURNS MORE SOUTHEASTERLY. KIT CARSON AND CHEYENNE COUNTIES COLORADO SHOULD SEE THE MOST CLOUD COVER...AND THIS MAY HINDER AFTERNOON HIGH TEMPERATURES JUST A BIT. ALSO EXPECT AFTERNOON CUMULUS TO DEVELOP NORTH OF THE INTERSTATE. TAKING A LOOK AT INSTABILITY...THE 12Z DENVER SOUNDING SHOWED AN IMPROVEMENT IN MID LEVEL LAPSE RATES COMPARED TO RECENT DAYS. MODELS DO NOT DEVELOP ANY INSTABILITY OR THUNDERSTORMS THIS AFTERNOON...BUT MODIFIED GFS AND RUC SOUNDINGS INDICATE AN AXIS OF AT LEAST 500 J/KG CAPE OVER EAST CENTRAL COLORADO IF TEMPERATURES CAN REACH THE LOWER 80S. ON THE OTHER HAND...MID LEVEL FORCING IS ABSENT. LOW LEVEL UPSLOPE APPEARS THE ONLY SOURCE OF LIFT. FEEL THIS IS INSUFFICIENT TO WARRANT POPS IN THE ZONES...BUT WOULD NOT BE SURPRISED TO SEE A FEW ATTEMPTS AT THUNDERSTORM DEVELOPMENT ALONG AND WEST OF HIGHWAY 385 THIS AFTERNOON. THE ACTIVITY WOULD LIKELY BE SHORT-LIVED AND HAVE LITTLE IMPACT. && .PREV DISCUSSION... (ISSUED 140 AM MDT MON AUG 15 2005) DISCUSSION...THE SHORT RANGE MODELS ARE IN REASONABLE AGREEMENT WITH THE LARGE SCALE PATTERN THROUGH THE SHORT TERM PERIODS. THE SUBTROPICAL RIDGE ACROSS THE SOUTHEAST WILL BUILD ACROSS THE GULF COAST AND INTO THE SOUTHERN PLAINS WHILE THE SHORT WAVE TROUGH NEAR SOUTHERN CALIFORNIA LIFTS SLOWLY NORTH AND EVENTUALLY RIDES OVER THE RIDGE INTO THE CENTRAL/NORTHERN PLAINS BY MIDWEEK. SEE LITTLE REASON FOR MAJOR CHANGES THROUGH TUESDAY WITH A GRADUAL WARMING TREND. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...A SHORT WAVE WILL MOVE INTO WESTERN NEBRASKA TUESDAY NIGHT WITH THE BEST FORCING REMAINING NORTH OF THE AREA. DECIDED TO HOLD THE DRY FORECAST TUESDAY NIGHT ALTHOUGH THE GFS IS ADVERTISING PRECIPITATION. WEDNESDAY LOOKS MORE INTERESTING AS LEE TROUGH DEVELOPS ALONG THE KANSAS/COLORADO BORDER AREA ACROSS THE SOUTHWEST ZONES AND THE EXIT REGION OF UPPER JET BUILDS ACROSS THE CENTRAL HIGH PLAINS LATE IN THE PERIOD. EXPECT SCATTERED COVERAGE AFTER 18Z IN CONVERGENCE NORTH OF LEE TROUGH ALONG THE PALMER DIVIDE. 0-6KM MEAN WIND WILL ALLOW THUNDERSTORMS TO QUICKLY SPREAD ACROSS THE EAST/NORTHEAST ZONES. KEPT AN EVENING MENTION WITH THE HIGHEST POPS ACROSS THE NORTHEAST ZONES. DAYS 4 THROUGH 7...NO CHANGES. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ BURKE/MWM ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 1045 AM EDT MON AUG 15 2005 .UPDATE... SATELLITE TRENDS SHOW CLOUDS HAVE BEEN SLOW TO EXIT CENTRAL PORTIONS OF OUR FORECAST AREA. SURFACE OBS HAVE SHOWN A RATHER WEAK PUSH BEHIND THE FRONT...WITH THE FRONTAL BOUNDARY STALLING AS UPPER LEVEL FLOW BECOMES PARALLEL WITH THE BOUNDARY. 12Z RUC/NAM DATA ALSO SUPPORT THE SLOWER CLEARING. WILL ADJUST ZONES TO REFLECT MORE CLOUD COVER...ESPECIALLY IN SOUTHERN SECTIONS. SHOWERS HAVE MOVED TO EXTREME SOUTHERN NEW HAMPSHIRE...AND SHOULD BE OUT OF HERE BY ISSUANCE TIME. WILL TWEAK TEMPERATURES BASED ON CLOUD TRENDS (UP IN CLEAR AREAS...DOWN IN CLOUDY AREAS). ALSO ADJUSTED HOURLY TEMPERATURE/DEWPOINT GRIDS TO REFLECT CURRENT OBS. DEW POINTS WERE RUNNING SEVERAL DEGREES HIGHER THAN PREVIOUS MODEL FORECASTS. && .SHORT TERM (TODAY THROUGH TONIGHT)...SHRA VERY SLOW TO EXIT THE COASTLINE. GFS IN THE SHORT RANGE DROPS HEALTHY DOES OF QPF THROUGH THE EARLY MORNING HOURS TO THE COASTLINE...AND TO SOME EXTENT...THIS IS VERIFYING. PCPN SHOULD BE OFF THE COASTLINE BY 13Z. DRYING SLOW TO OCCUR OVER SOUTHERN AREAS TODAY AS PLENTY OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE ON A NE FLOW. CLEARING TO ARRIVE FROM NORTH TO SOUTH LATE. WILL GO WITH MOSTLY CLEAR SKIES TONIGHT ALL ZONES. WINDS WILL BECOME LIGHT HOWEVER. WITH A MOIST GROUND FROM LAST NIGHT'S RAIN... EXPECT TEMPS TO QUICKLY COOL TO DEW POINT LEVELS. EXPECT AT LEAST PATCHY FOG...HOWEVER THE FOG MAY BE MORE WIDESPREAD THAN THIS. A VERY CHILLY NIGHT ON TAP FOR THE MOUNTAINS. && .LONG TERM (TUESDAY THROUGH SUNDAY)... A RATHER BENIGN WEATHER PATTERN THROUGH THE WEEK. A WEAK DISTURBANCE WILL MOVE THRU THE AREA LATE TUESDAY AND TUESDAY NIGHT THEN FOLLOWED BY A WIND SHIFT TO A DRIER NWLY SURFACE FLOW FOR WED AND THU AS CANADIAN HIGH PRESSURE BUILDS ACROSS NORTHERN NEW ENGLAND. A RETURN TO THE HEAT AND HUMIDITY MAY OCCUR OVER THE WEEKEND AND IN ADVANCE OF THE 3H(HAZY HOT HUMID) WEATHER CLOUDS WITH SHOWERS AND THUNDERSTORMS MAY BE NOTED AHEAD OF THE WARM FRONT FRIDAY NIGHT AND AGAIN SATURDAY. && .AVIATION...AREAS OF IFR THIS MORNING...FOLLOWED BY LIFTING CEILINGS. MOSTLY CLEAR TONIGHT...BUT IFR CONDITIONS DEVELOPING AS FOG DEVELOPS IN PROTECTED AREAS. && .MARINE...WILL DROP THE SCA THIS AFTERNOON. WINDS APPEAR TO HAVE PEAKED EARLY THIS MORNING...WITH GUSTS AT 20 TO 25 KT. THIS BROUGHT SEAS UP TO 3 TO 4 FT IN MOST OF OUR WATERS. WITH WINDS ON THEIR WAY DOWN...SEAS SHOULD LEVEL OFF...AND EVENTUALLY DROPPING. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE && $$ UPDATE: APFFEL me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1050 PM EDT MON AUG 15 2005 .UPDATE... MAIN FCST ISSUE OVERNIGHT IS POTENTIAL OF SHRA. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A STRONG SHORTWAVE SLIPPING INTO NW ONTARIO WITH ASSOCIATED UPPER JET EXTENDING ACROSS SRN MANITOBA INTO ONTARIO. ASSOCIATED COLD FRONT RUNS FROM ND INTO NW MN AND ONTARIO. ISOLD/SCT CONVECTION WAS OCCURRING AHEAD OF FRONT EARLIER THIS EVENING...BUT ACTIVITY DISSIPATED. HOWEVER...SHRA HAVE ACTUALLY REDEVELOPED IN NE MN DURING THE LAST HR. ANOTHER SHORTWAVE MOVING INTO SRN MN HAS PRODUCED A BATCH OF MID CLOUDS FROM SRN MN INTO WCNTRL WI. 00Z KINL SOUNDING SHOWED SBCAPE UPWARDS OF 1000J/KG WHICH SUPPORTED ISOLD/SCT CONVECTION LATE AFTN/EARLY EVENING. WITH LOSS OF DAYTIME HEATING...CONVECTION WILL NO LONGER BE SFC BASED. AS FOR ELEVATED CONVECTION...SMALL AREA OF 200-400J/KG CAPE FOR PARCELS LIFTED FROM 850MB OVER NE MN RIGHT NOW PER RUC WHERE CURRENT SHRA ARE REDEVELOPING GRADUALLY LOWERS BLO 100 J/KG AS IT SHIFTS E TOWARD THE KEWEENAW OVERNIGHT...SUGGESTING SHRA POTENTIAL WILL BE LIMITED FARTHER E. EVEN SO...WILL HOLD ONTO SLIGHT CHC FOR THE KEWEENAW OVERNIGHT. WILL REMOVE ANY PCPN MENTION ELSEWHERE. && .PREV DISCUSSION... DISCUSSION ISSUED AT 430 PM EDT. FOR TONIGHT STILL LOOKS TO BE A SLIGHT CHANCE FOR MAINLY A LIGHT RAIN SHOWER AS UPPER DISTURBANCE TRACKS TO OUR NORTH AND UPPER MICHIGAN RECEIVES THE TAIL END OF ASSOCIATED DYNAMICS...MAINLY WEAK 850MB-700MB Q-VECT CONVERGENCE AND MINIMAL UPPER SUPPORT FROM 300MB JET STREAK TRACKING THROUGH NORTHERN ONTARIO. HIGH PRES BUILDING DOWN SHOULD REMAIN IN CONTROL FOR TUE THROUGH WED...WITH GOOD RADIATIONAL COOLING TUE NIGHT. OVERNIGHT LOWS ARE EXPECTED TO DROP INTO THE LOWER TO MIDDLE 40S...WITH WARMER TEMPS NEAR THE LAKESHORES. FOR WED...SURFACE LOW DEVELOPING OVER THE NORTHERN PLAINS AS SHORTWAVE EJECTS INTO THE DAKOTAS LOOKS TO CREATE A DECENT RETURN FLOW...WITH HIGH TEMPERATURES WARMING SLIGHTLY ON WED AND AGAIN ON THU AS 850MB TEMPS RISE TO 14C TO 16C. WITH THE WARM AIR ADVECTION AND INCREASING 310K ISENTROPIC LIFT...EXPECTING SHRA/TSRA CHANCES TO ARRIVE TO THE WESTERN CWA WED AFTERNOON AND CONTINUE THROUGH THU AFTERNOON AS CWA LIES IN THE WARM SECTOR. GFS/NAM SHOW SOME CONVECTIVE FEEDBACK PROBLEMS...PUTTING LARGE AMOUNTS OF QPF OVER THE UPPER GREAT LAKES AND NOSING AN INVERTED TROUGH INTO THE CWA. HAVE LEANED TOWARD THE ECMWF SOLUTION WHICH DEPICTS LIGHTER STRATIFORM RAINFALL...WITH MORE INTENSE SHOWER/THUNDERSTORM ACTIVITY FOR THU NIGHT INTO FRI AS COLD FRONT MOVES THROUGH. IN THE EXTENDED...A DRASTIC CHANGE FROM PREVIOUS MODEL RUNS...AS THE GENERAL CONSENSUS NOW IS FOR A SLOWER TREND OF THE SHORTWAVE MOVING THROUGH SOUTHERN CANADA...AND THE SURFACE TROUGH TO IMPACT THE UPPER MIDWEST AND GREAT LAKES THROUGH SAT. THERE IS SOME SLIGHT DIFFERENCES WITH THE OVERALL TRACK OF THE UPPER LOW...GFS IS MORE SOUTHERLY TAKING IT ACROSS UPPER MICHIGAN BY 12Z SUN...WHILE THE ECMWF/UKMET DEPICT A MORE PROGRESSIVE AND NORTHERLY TRACK FROM SOUTHERN MANITOBA AT 00Z SAT TO JAMES BAY BY 00Z SUN. HPC GUIDANCE FAVORS THE ECMWF/UKMET SOLUTIONS GIVEN THE INCONSISTENCY BETWEEN GFS MODEL RUNS...AND WILL FOLLOW SUIT. THIS DEPICTS THE TROUGH OVER THE UPPER GREAT LAKES ON FRI AND SAT WITH SURFACE HIGH PRES BUILDING OVERHEAD FOR SUN AND MON. TEMPERATURES SHOULD BE ABOVE NORMAL FOR FRI AS CWA LIES IN THE WARM SECTOR...THEN AS THE FRONT MOVES THROUGH EXPECT A COOL DOWN FOR THE WEEKEND. AS TO HOW MUCH COLD AIR ADVECTION WILL OCCUR REMAINS TO BE SEEN...ECMWF DEPICTS 850MB TEMPS DROPPING TO AROUND 6C ACROSS THE CWA BY 00Z SUN. WITH SURFACE HIGH OVERHEAD ON SUN AND POTENTIAL FOR GOOD RADIATIONAL COOLING...COULD BE A CHILLY NIGHT FOR THE INLAND AREAS SUN NIGHT. HOWEVER GIVEN THE RECENT LOW CONFIDENCE WITH DAYS 6-7 OF THE FORECAST...WILL HOLD OFF ON GOING TOO MUCH BELOW GUIDANCE. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON (UPDATE) LAROSA (DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 1207 PM CDT MON AUG 15 2005 .DISCUSSION... BASED ON LATEST OBSERVATION AND RADAR TRENDS...WILL NOT MAKE ANY FURTHER CHANGES TO THE GOING FORECAST. WSR 88-D REGIONAL MOSAIC SHOWING SHRA/TSRA DEVELOPMENT TO OUR SOUTH...WEST AND NORTH THIS HOUR. HIGHEST CONCENTRATION OF ACTIVITY IS ALONG THE SEABREEZE CONVERGENCE ZONE ALONG THE LA COAST...AND IN THE VERY MOIST ATMOSPHERE OVER E TX/W LA/SW ARK. 250MB JET DIAGNOSIS FROM THE LATEST RUC ANALYSIS HAS MY NW ZONES UNDER THE FAVORABLE RIGHT ENTRANCE REGION...HOWEVER THIS AREA IS ALSO IN A LOW LEVEL (1000-850MB) THETA-E MINIMA. IN ADDITION...SFC DEWPOINTS HAVE MIXED OUT INTO THE UPPER 60S. CONVECTION DEVELOPING OVER W/LA AND S ARK IS ASSOC WITH SOME WEAK LOW LEVEL THETA-E ADVECTION...WHICH MAY COUNTERACT THE MINIMA CURRENTLY OBSERVED. IN ANY EVENT...CONVECTION WILL FLIRT W/ MY NW ZONES AND WILL MAINTAIN LOW CHC POPS. ELSEWHERE...VIS IMAGERY STILL SHOWING A VOID OF CU. THIS WILL CHANGE THIS AFTERNOON W/ A CU FIELD DEVELOPING AROUND 5KFT. LIKE YESTERDAY...LITTLE IN THE WAY OF UPPER SUPPORT FOR ORGANIZATION OF SHRA/TSRA...HOWEVER THERE IS LITTLE TO PREVENT VERY ISO AIRMASS SHRA/TSRA. THE LACK OF WIND SHEAR (SFC-6KM VALUES AT 3 M/S) WILL MEAN THAT ANYTHING THAT DOES DEVELOP WILL NOT MOVE VERY FAR. THIS WILL RESULT IN MOST AREAS OBSERVING NO RAINFALL...AND VERY ISO SPOTS SEEING A HALF INCH OF RAINFALL. SO...GOING FORECAST OF SLIGHT CHC POPS QUITE REASONABLE. TEMPS ARE ON TRACK AND NO CHANGES ARE NEEDED. NEW ZONES OUT SHORTLY. && .AVIATION... 18Z PACKAGE WILL FEATURE A PERSISTENCE FORECAST...WITH VCTS AT KHBG AND KGLH THIS AFTERNOON. A SCT CU DECK AT 5KFT WILL DEVELOP THIS AFTERNOON AND DISINTEGRATE AFTER SUNSET. BRIEF MVFR VIS EXPECTED AGAIN TOMORROM MORNING MOST SITES...OTHERWISE NO OTHER RESTRICTIONS EXPECTED. && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ GAGAN ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 1025 AM CDT MON AUG 15 2005 .DISCUSSION... BASED ON THIS MORNING'S SOUNDING...AND CURRENT WAT VAP/RUC INITIALIZATION DATA...HAVE DECIDED TO UPDATE THE FORECAST. AS EXPECTED...THE UPPER RIDGE CENTERED OVER THE AREA WILL THWART SHRA/TSRA DEVELOPMENT AGAIN TODAY. PWS ARE A LITTLE LOWER TODAY... AROUND 1.7 INCHES...AND SFC DEWPOINTS ARE EXPECTED TO MIX OUT INTO THE UPPER 60S/LOWER 70S. WITH A GREAT DEAL OF SUN EXPECTED...HIGH TEMPS SHOULD BE VERY SIMILAR TO YESTERDAY (93-97F). ALL OF THIS WILL RESULT IN SBCAPES AND MLCAPES AROUND 2500 J/KG WITH LIS AROUND -6C. WHILE LAPSE RATES ARE STILL QUITE DECENT FOR THIS TIME OF YEAR (6.7C/KM AND 850/500 T DIFFERENCE OF 28C)...THE LACK OF FOCUSING MECHANISMS WILL KEEP RAIN CHANCES BELOW CLIMO TODAY. FOR NOW...HAVE CUT POPS BACK IN MY CENTRAL ZONES TO SLIGHT CHC...AND LOWERED POPS IN MY NW ZONES TO 30%. ANOTHER UPDATE MAY BE NEEDED TO ADDRESS LOWERING POPS AGAIN IN THE NW AS A THETA-E MIN HAS BEEN NOTED IN THIS AREA AT LOW LEVELS. AM EXPECTING THE SEABREEZE CONVERGENCE TO APPROACH SW ZONES BY LATE AFTERNOON AND NO CHANGES WERE MADE TO THE POPS IN THIS AREA. PRODUCTS ALREADY SENT. && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ GAGAN ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 917 AM MDT MON AUG 15 2005 .SHORT TERM...FOR NORTHEAST MONTANA TODAY THROUGH WEDNESDAY...UPDATE MORNING SATELLITE IMAGES SHOW A DECK OF CLOUDS JUST ALONG THE NORTHERN BORDER. THESE CLOUDS SHOULD REMAIN IN THIS LOCATION AS UPPER LEVEL FLOW IS FROM THE WEST-NORTHWEST. ALSO MODELS/RUC AND ETA/INDICATE VIA THE CU RULE THAT CLOUDS SHOULD NOT DEVELOP MUCH DURING THE DAY. SO HAVE REDUCED SKY COVER IN THE GRIDS AND THIS RESULTS IN LESS CLOUDY WORDING IN THE ZONES. TEMPERATURES LOOK GOOD AND SO DOES WIND. WILL HAVE UPDATE OUT SHORTLY. TLSJR .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... MODELS STARTING TO COME INTO BETTER AGREEMENT TOWARD THE END OF THE PERIOD...BUT STILL PLENTY OF UNCERTAINTY DURING THE BEGINNING OF THE PERIOD. FOR THE SECOND NIGHT IN A ROW GFS HAS PUSHED BACK TIMING OF COLD FRONT...WITH ITS SOLUTION NOW SHOWING FRONTAL PASSAGE WEDNESDAY NIGHT. OTHER MODELS A BIT QUICKER WITH THE FRONT...AND WILL LEAN TOWARD THIS SOLUTION. IN EITHER CASE TEMPERATURES THURSDAY WILL BE ON THE COOL SIDE. HAVE KEPT THINGS NEAR ENSEMBLE MEAN...WITH A 25-30 DEGREE SPREAD BETWEEN WARMEST AND COOLEST MEMBERS AT ALL LOCATIONS OF THE FORECAST AREA. BAROCLINIC ZONE ASSOCIATED WITH FRONT SHOULD RESULT IN CHANCE OF SHOWERS AND STORMS...SO HAVE KEPT POPS AS IS WEDNESDAY NIGHT AND THURSDAY. THURSDAY NIGHT INTO FRIDAY MODELS BEGINNING TO PULL SURFACE LOW FURTHER SOUTH SO BACKED OFF POPS...BUT WITH UPPER LOW IN THE AREA A FEW SHOWERS NOT OUT OF THE QUESTION. FOR THE WEEKEND INTO EARLY NEXT WEEK LATEST MODEL RUNS HAVE COME INTO AGREEMENT THAT UPPER RIDGE WILL AMPLIFY OVER THE AREA WITH TROUGH DIGGING OFF THE WEST COAST. DRY AND WARM FORECAST ALREADY IN PLACE...AND ONLY CHANGES WERE TO BUMP UP TEMPS A TAD AND LOWER CLOUD COVER. WILL NEED TO KEEP AN EYE ON HOW STRONG THERMAL RIDGE GETS...AS PATTERN COULD RESULT IN TEMPERATURES CLIMBING BACK INTO THE 90S. JJZ && .AVIATION... HIGH PRESSURE IN CONTROL OVER THE AREA...SO EXPECT VFR CONDITIONS THROUGH MONDAY NIGHT. LIGHT WINDS ALSO EXPECTED THROUGH MONDAY NIGHT...EXCEPT AT KGGW WHERE EAST WIND IN THE MID TEENS EXPECTED TO DEVELOP BY MIDNIGHT. JJZ && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 603 PM EDT MON AUG 15 2005 .SHORT TERM (REST OF TONIGHT)... WILL ISSUE AN EARLY UPDATE TO TONE DOWN THE POPS THIS EVENING. && .PREVIOUS DISCUSSION... (ISSUED 220 PM EDT MON AUG 15 2005) SHORT TERM (TONIGHT THROUGH THURSDAY)... THROUGH TONIGHT: CONVECTION POPPING OVER THE HIGHER TERRAIN BENEATH THE UPPER LEVEL SHEAR AXIS SHOULD PROPAGATE SOUTHEASTWARD INTO THE PIEDMONT OVER THE NEXT FEW HOURS AS TEMPS ACROSS THE CWA HIT THE CONVECTIVE TEMP. ACTIVITY HAS ALSO DEVELOPED ALONG THE VERY WEAK SURFACE TROUGH BISECTING THE CWA & THIS IS LIKELY TO FILL IN AS WELL. WILL CARRY SCATTERED STORMS... MORE NUMEROUS ACROSS THE NORTH EARLY TRANSLATING TO THE SOUTH LATE THIS EVENING... THEN DRY OVERNIGHT WITH THE NAM INDICATING PREVAILING NW FLOW AT 850 MB. THE RUC INDICATES A STEEPENING SUBCLOUD LAYER LAPSE RATE THROUGH 00Z & WILL NEED TO WATCH FOR POTENTIAL STRONG DOWNDRAFTS WITH ISOLATED CELLS. LOWS 71-75. TUE THROUGH THU: DISTINCT LARGE-SCALE FORCING FEATURES ARE HARD TO COME BY... WHICH MAKES TRYING TO TIME RAINFALL WITH ANY PRECISION DIFFICULT. THE NAM/GFS HOLD A WEAK SURFACE TROUGH OVER THE EASTERN PIEDMONT AND COASTAL PLAIN THROUGH TUE THEN DROP IT WELL SOUTH AS THE SYNOPTIC FRONT PUSHES IN FROM THE NORTH. THE LATEST GFS RUN CONTINUES TO PUSH THE FRONT & DRIER AIR TO SOUTHEAST NC BY LATE WED WITH THE NAM LAGGING A LITTLE BEHIND. HAVE SOME SKEPTICISM THAT MUCH IN THE WAY OF LOW LEVEL DRY AIR WILL MAKE IT INTO NC SINCE CURRENT PRECIP LOOKS TO BE LARGELY BEHIND THE FRONT FROM MO TO OH... SO WHILE SURFACE WINDS ARE LIKELY TO BE NW OR N FROM LATE WED INTO THU... TEND TO FAVOR THE GFS'S WETTER SOLUTION WITH ISENTROPIC UPGLIDE ON THE 305K SURFACE. WILL HOLD ONTO SCATTERED STORMS TUE. HIGHER CHANCES WED WITH WEAK MID LEVEL WAVE PASSING THROUGH... AND IF LATER MODEL RUNS COME INTO BETTER AGREEMENT... LIKELY POPS MIGHT BE WARRANTED IN LATER FORECASTS. EXPECT HIGHS 90-96 TUE... THEN 82-87 WED WHICH IS A NOTCH ABOVE GFS MOS GUIDANCE. WITH THE POSSIBILITY THAT A BOUNDARY MAY LIE ACROSS SOUTHERN NC THU & WITH BOTH MODELS SHOWING DRYING AND STABILIZATION ACROSS THE NORTH... WITH KEEP CHANCE POPS PRIMARILY SOUTH FOR THU WITH HIGHS 81-86... NEAR GFS ENSEMBLE MOS. LONG TERM (THURSDAY NIGHT THROUGH MONDAY)... THE PRIMARY FEATURES FOR THIS TIME PERIOD INCLUDE AN ANOMALOUS UPPER VORTEX TRACKING ACROSS SOUTHERN CANADA PRODUCING A BRIEF SOUTHWARD NUDGE OF THE WESTERLIES...AND THE RESIDUAL FRONTAL ZONE THAT IS LIKELY TO BE STRETCHED ACROSS NC FRI BEFORE GRADUALLY DISSOLVING AND RETREATING NORTHWARD OVER THE WEEKEND. MEDIUM RANGE MODELS DIFFER ON SYSTEM SPEED AND TROUGH AMPLITUDE ALTHOUGH THIS APPEARS TO NOT HAVE SIGNIFICANT RAMIFICATIONS FOR NC UNTIL TUE ONWARD. THE LATEST GFS IS NOT AS DEEP AS THE 00Z GFS/06Z DGEX AND THIS LESS AMPLIFIED SOLUTION LOOKS MORE REASONABLE. WITH CONSIDERABLE UNCERTAINTY ABOUT WHETHER OR NOT THE FRONT AND ASSOCIATED MOISTURE WILL PUSH WELL TO OUR SOUTH THU BASED ON THE WEAK CHARACTER OF THE NOSING HIGH TO THE NORTH AND ITS UPPER JET... FAVOR A RETENTION OF CHANCE POPS DAILY... SCATTERED SHOWERS AND STORMS ROUGHLY 16Z-02Z FOLLOWED BY ISOLATED SHOWERS AT NIGHT... WITH HIGHEST VALUES ACROSS THE SOUTHERN CWA WHERE LOW LEVEL CONVERGENCE IS LIKELY TO BE MAXIMIZED. ON FRI A MINOR MID LEVEL PERTURBATION CROSSES EASTERN NC AND MOVES OFF THE COAST WITH INCREASINGLY DIFFLUENT 850 MB FLOW... SO POPS SHOULD HOLD ON THE LOW END OF CHANCE IN THE NORTH & SLIGHTLY HIGHER ALONG THE SOUTH/EAST FRINGES. EXPECT A BIT BETTER POPS FOR SAT... STILL HIGHEST SOUTHEAST AS THE FRONT HEADS NORTHWARD & A LOW LEVEL SHEAR ZONE SITS OVER THE COASTAL PLAIN. 850 MB FLOW INCREASES FROM THE WNW ON SUNDAY THROUGH MON WITH THE SYNOPTIC FRONT ACCORDING TO THE GFS LIKELY TO EXTEND ACROSS VA/KY SUNDAY AND SRN VA/TN MON... SO CONVECTIVE COVERAGE SHOULD BE LESS PARTICULARLY OVER THE IMMEDIATE LEE AREAS BOTH DAYS. PROGGED THICKNESSES SUGGEST TEMPS SHOULD HIT JUST BELOW NORMAL FRI THEN ABOVE NORMAL SAT-MON. AVIATION... CONVECTION BEGINNING AT THIS TIME WITH SOME CELLS MOVING IN FROM THE FOOTHILLS. LITTLE REASON TO THINK ACTIVITY WILL PERSIST MUCH PAST SUNSET. DO NOT EXPECT VISIBILITIES TO FALL MUCH BELOW SIX MILES AFTER MIDNIGHT OUTSIDE THE INFLUENCE OF RIVERS OR LAKES. CEILINGS UNLIMITED OUTSIDE CONVECTION AND AREA WIDE AFTER DARK. CUMULUS SHOULD DEVELOP EARLIER IN THE DAY TUESDAY THAN TODAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MLM nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 220 PM EDT MON AUG 15 2005 .SHORT TERM (TONIGHT THROUGH THURSDAY)... THROUGH TONIGHT: CONVECTION POPPING OVER THE HIGHER TERRAIN BENEATH THE UPPER LEVEL SHEAR AXIS SHOULD PROPAGATE SOUTHEASTWARD INTO THE PIEDMONT OVER THE NEXT FEW HOURS AS TEMPS ACROSS THE CWA HIT THE CONVECTIVE TEMP. ACTIVITY HAS ALSO DEVELOPED ALONG THE VERY WEAK SURFACE TROUGH BISECTING THE CWA & THIS IS LIKELY TO FILL IN AS WELL. WILL CARRY SCATTERED STORMS... MORE NUMEROUS ACROSS THE NORTH EARLY TRANSLATING TO THE SOUTH LATE THIS EVENING... THEN DRY OVERNIGHT WITH THE NAM INDICATING PREVAILING NW FLOW AT 850 MB. THE RUC INDICATES A STEEPENING SUBCLOUD LAYER LAPSE RATE THROUGH 00Z & WILL NEED TO WATCH FOR POTENTIAL STRONG DOWNDRAFTS WITH ISOLATED CELLS. LOWS 71-75. TUE THROUGH THU: DISTINCT LARGE-SCALE FORCING FEATURES ARE HARD TO COME BY... WHICH MAKES TRYING TO TIME RAINFALL WITH ANY PRECISION DIFFICULT. THE NAM/GFS HOLD A WEAK SURFACE TROUGH OVER THE EASTERN PIEDMONT AND COASTAL PLAIN THROUGH TUE THEN DROP IT WELL SOUTH AS THE SYNOPTIC FRONT PUSHES IN FROM THE NORTH. THE LATEST GFS RUN CONTINUES TO PUSH THE FRONT & DRIER AIR TO SOUTHEAST NC BY LATE WED WITH THE NAM LAGGING A LITTLE BEHIND. HAVE SOME SKEPTICISM THAT MUCH IN THE WAY OF LOW LEVEL DRY AIR WILL MAKE IT INTO NC SINCE CURRENT PRECIP LOOKS TO BE LARGELY BEHIND THE FRONT FROM MO TO OH... SO WHILE SURFACE WINDS ARE LIKELY TO BE NW OR N FROM LATE WED INTO THU... TEND TO FAVOR THE GFS'S WETTER SOLUTION WITH ISENTROPIC UPGLIDE ON THE 305K SURFACE. WILL HOLD ONTO SCATTERED STORMS TUE. HIGHER CHANCES WED WITH WEAK MID LEVEL WAVE PASSING THROUGH... AND IF LATER MODEL RUNS COME INTO BETTER AGREEMENT... LIKELY POPS MIGHT BE WARRANTED IN LATER FORECASTS. EXPECT HIGHS 90-96 TUE... THEN 82-87 WED WHICH IS A NOTCH ABOVE GFS MOS GUIDANCE. WITH THE POSSIBILITY THAT A BOUNDARY MAY LIE ACROSS SOUTHERN NC THU & WITH BOTH MODELS SHOWING DRYING AND STABILIZATION ACROSS THE NORTH... WITH KEEP CHANCE POPS PRIMARILY SOUTH FOR THU WITH HIGHS 81-86... NEAR GFS ENSEMBLE MOS. && .LONG TERM (THURSDAY NIGHT THROUGH MONDAY)... THE PRIMARY FEATURES FOR THIS TIME PERIOD INCLUDE AN ANOMALOUS UPPER VORTEX TRACKING ACROSS SOUTHERN CANADA PRODUCING A BRIEF SOUTHWARD NUDGE OF THE WESTERLIES...AND THE RESIDUAL FRONTAL ZONE THAT IS LIKELY TO BE STRETCHED ACROSS NC FRI BEFORE GRADUALLY DISSOLVING AND RETREATING NORTHWARD OVER THE WEEKEND. MEDIUM RANGE MODELS DIFFER ON SYSTEM SPEED AND TROUGH AMPLITUDE ALTHOUGH THIS APPEARS TO NOT HAVE SIGNIFICANT RAMIFICATIONS FOR NC UNTIL TUE ONWARD. THE LATEST GFS IS NOT AS DEEP AS THE 00Z GFS/06Z DGEX AND THIS LESS AMPLIFIED SOLUTION LOOKS MORE REASONABLE. WITH CONSIDERABLE UNCERTAINTY ABOUT WHETHER OR NOT THE FRONT AND ASSOCIATED MOISTURE WILL PUSH WELL TO OUR SOUTH THU BASED ON THE WEAK CHARACTER OF THE NOSING HIGH TO THE NORTH AND ITS UPPER JET... FAVOR A RETENTION OF CHANCE POPS DAILY... SCATTERED SHOWERS AND STORMS ROUGHLY 16Z-02Z FOLLOWED BY ISOLATED SHOWERS AT NIGHT... WITH HIGHEST VALUES ACROSS THE SOUTHERN CWA WHERE LOW LEVEL CONVERGENCE IS LIKELY TO BE MAXIMIZED. ON FRI A MINOR MID LEVEL PERTURBATION CROSSES EASTERN NC AND MOVES OFF THE COAST WITH INCREASINGLY DIFFLUENT 850 MB FLOW... SO POPS SHOULD HOLD ON THE LOW END OF CHANCE IN THE NORTH & SLIGHTLY HIGHER ALONG THE SOUTH/EAST FRINGES. EXPECT A BIT BETTER POPS FOR SAT... STILL HIGHEST SOUTHEAST AS THE FRONT HEADS NORTHWARD & A LOW LEVEL SHEAR ZONE SITS OVER THE COASTAL PLAIN. 850 MB FLOW INCREASES FROM THE WNW ON SUNDAY THROUGH MON WITH THE SYNOPTIC FRONT ACCORDING TO THE GFS LIKELY TO EXTEND ACROSS VA/KY SUNDAY AND SRN VA/TN MON... SO CONVECTIVE COVERAGE SHOULD BE LESS PARTICULARLY OVER THE IMMEDIATE LEE AREAS BOTH DAYS. PROGGED THICKNESSES SUGGEST TEMPS SHOULD HIT JUST BELOW NORMAL FRI THEN ABOVE NORMAL SAT-MON. && .AVIATION... CONVECTION BEGINNING AT THIS TIME WITH SOME CELLS MOVING IN FROM THE FOOTHILLS. LITTLE REASON TO THINK ACTIVITY WILL PERSIST MUCH PAST SUNSET. DO NOT EXPECT VISIBILITIES TO FALL MUCH BELOW SIX MILES AFTER MIDNIGHT OUTSIDE THE INFLUENCE OF RIVERS OR LAKES. CEILINGS UNLIMITED OUTSIDE CONVECTION AND AREA WIDE AFTER DARK. CUMULUS SHOULD DEVELOP EARLIER IN THE DAY TUESDAY THAN TODAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...RLH nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 140 PM EDT MON AUG 15 2005 .SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...SAT AND RADAR PIX SHOWG CBRZ JUST STRTG TO FORM DURING THE ERLY AFTN HRS. THRS A LTL ACTVTY JUST N OF CWA AND IN SC. WND MAY HV TOO MUCH OF A WLY COMPONENT TO ALLOW CBRZ TO PENETRATE TOO FAR INLAND. WL GO WI ISOLD NR THE CST TNGT WI NO MNTN PCPN INLAND...UNLESS THINGS CHGS BFR ISSUE TM. ON TUE XPCT MR CHC AS THE LO LVL CNVRGNC STARTS TO INCRS WI THE TROF TO OUR W. FRNT TO DROP INTO TROF POSN TUE EVE AND THRU THE AREA BY SR WED. WL HV HIEST POPS TUE EVE AND NGT. TEMPS WL BE SEASONABLE TNGT THRU TUE NGT WI HIGHS IN THE 90S AND LOWS IN THE 70S. HTNDX WL BE HI TUE AHD OF THE APPCHG FRNT...BUT DONT XPCT IT TO RCH ADV CRIT. WL HDLN IT IN THE ZFP. && .LONG TERM (WEDNESDAY THROUGH MONDAY)...TEMPS TO DROP WED BHND FRNT. WL HV NO WX IN GRIDS BHDN FRNT IN NLY FLO SINCE MDLS SHOWG A MARKED DCRS IN MSTR. ONSHR FLO WL INCRS MSTR AGAIN THU AFTN SO HV TYPICAL DIURNAL ACTVTY THU INTO SAT. TEMPS TO COME BACK TO SEASONABLE BY THE END OF THE WK. BEGINNING OF NXT WK CUD SEE ANTHR SYS TO DROP INTO AREA SO HV INCRSD POPS FOR THE LAST PD. && .AVIATION...ISOLATED TSTMS FORMING ON THE SEABREEZE AGAIN THIS AFTERNOON. MAY PRODUCE A TEMPORARY REDUCTION TO MVFR CONDITIONS...BUT OVERALL JUST SCATTERED VFR CUMULUS FOR THE BALANCE OF THE DAY. BUFKIT FOG ANALYSIS SHOWS LTL IN THE WAY OF DENSE FOG FORMATION TONIGHT WITH LOW CROSSOVER TEMPS...BUT WILL INCLUDE HAZE IN AVIATION PRODUCTS TOWARD MORNING. && .MARINE...LIGHT MAINLY OFFSHORE FLOW PRODUCING 2 TO 3 FT SEAS THIS AFTERNOON. AS PREDICTED BY RUC...FLOW IS STARTING TO BACK AND BECOME MORE S/SSW AS WEAK SEABREEZE DEVELOPS THIS AFTERNOON. FCST THRU TUES NIGHT WILL BE FOR CONTINUED LIGHT SW FLOW AND SEAS 2 TO 3 FT. BY WEDS...BOTH THE GFS AND DGEX PUSH BOUNDARY THRU MUCH OF THE CSTL WATERS. THIS BOUNDARY WILL MAINLY BE A WIND SHIFT LINE WITH LITTLE IN THE WAY OF TEMP/MOISTURE CHANGE ALONG IT. WINDS WILL VEER TO N/NE WEDS INTO EARLY THURS. THE FRONT THEN LIFTS BACK NORTH AND WILL EVENTUALLY WASH OUT WITH GENERAL FLOW BECOMING SE/S/SW AGAIN BY FRI INTO THE WEEKEND. SEAS REMAIN AOB 4 FT. NO SCA FLAGS ARE ANTICIPATED THRU THE FCST PERIOD. .RIP CURRENTS...WITH LITTLE IN THE WAY OF SWELL ENERGY AND LIGHT WINDS...WILL PROBABLY BE ABLE TO GO BACK DOWN TO A LOW THREAT OF RIP CURRENTS OVER THE NRN WATERS ON TUES. SRN WATERS WILL BE A LTL MORE MARGINAL...GIVEN SLIGHTLY MORE WINDS AND HIGH ASTRONOMICAL TIDES...AND MAY LOOK OVER A LTL MORE DATA BEFORE DECIDING. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ CGG/CTC nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 1050 AM CDT MON AUG 15 2005 .UPDATE... UPDATED TO ADD ISOLATED SHOWERS OVER NORTH PORTIONS OF THE CWA THIS AFTERNOON. CANADIAN RADAR SHOWS A FEW AREAS OF LIGHT SHOWERS JUST NORTH OF THE NORTH DAKOTA STATE LINE MOVING EAST SOUTHEAST ACROSS SOUTHERN MANITOBA. SHOWERS CONTINUE TO HOLD TOGETHER ALONG A WEAK SURFACE TROUGH WITH SUPPORT FROM AN UPPER LEVEL WAVE OVER NORTHERN MANITOBA. ALSO...EXTENDED THE SLIGHT CHANCE OF THUNDERSTORMS THIS EVENING OVER NORTHWEST AND WEST CENTRAL MINNESOTA WESTWARD. MODEL HAVE MOVED INTO BETTER AGREEMENT OVER THE SHORT-TERM WITH THE GFS BEING A LITTLE MORE AGRESSIVE WITH UPPER WAVE OVER NORTHERN CANADA. BOTH INDICATE PRECIPITATION DEVELOPMENT OVER PREVIOUSLY MENTIONED AREA THIS EVENING. INSTABLITY PARAMETERS ARE RELATIVELY WEAK WITH 0 TO +2 SHOWALTERS...LI OF -2 AND 0-6 KM BULK SHEAR OF 30 TO 35 KTS. WILL WAIT FOR 12Z GFS TO UPDATE THUNDER CHANCES IN THE NORTH. && .SYNOPSIS... 15Z ANALYSIS SHOWS GOOD UPPER LEVEL WAVE OVER NORTHERN MANITOBA WITH WEAK SURFACE TROUGH EXTENDING SOUTHWEST WARD ACROSS WESTERN MANITOBA AND INTO WESTERN NORTH DAKOTA. WEAK SHOWERS HAVE DEVELOPED AHEAD OF THE TROUGH ALONG A WIND SHIFT BOUNDARY. A SHORT WAVE OVER WESTERN SOUTH DAKOTA HAS DEVELOPED SOME SHOWER AND A LITTLE THUNDERSTORM ACTIVITY ACROSS THE CENTRAL AND EASTERN PORTIONS OF THE STATE. && .PREV DISCUSSION... (ISSUED 340 AM CDT MON AUG 15 2005) DISCUSSION AND SHORT TERM (TODAY-TONIGHT)...SEVERAL SHORTWAVES APPROACHING FROM THE WEST BUT NONE APPEAR A THREAT TO TOUCH OFF CONVECTION TODAY EXCEPT POSSIBLY ONE OVER NORTHWEST CORNER OF MT ATTM. A VERY WEAK ONE OVER EXTREME NORTHWEST ND IS PROGRESSING QUICKLY ON WATER VAPOR. ITS MOMENTUM WILL TAKE IT WELL EAST OF THE AREA BEFORE CONVECTION BEGINS. SO THUNDER WAS REMOVED FOR THIS AFTERNOON IN NORTHWEST MN. ONE OVER SOUTH CENTRAL MT WILL SLIDE INTO SD WITHOUT AFFECTING EASTERN ND. ONE GENERATING A FEW SHOWERS OVER SOUTHERN SASK AND ALBERTA IS NOT RECOGNIZED WELL BY MODELS...EXCEPT RUC DOES AT LEAST ACKNOWLEDGE ITS PRESCENCE BEFORE WASHING OUT THE SOUTHERN PORTION OF IT BEFORE ENTERING ND. ALL OF THESE ARE MUCH WEAKER THAN THE SHORTWAVE APPROACHING YESTERDAY MORNING AND THEY SHOW LESS POTENTIAL TO CAUSE STORMS. HOWEVER LEFT THE SLIGHT CHANCE FOR THIS EVENING IN THE OFF CHANCE THE SHORTWAVE IN NORTHWEST MT CAN LIFT MOISTURE IN SD TRYING TO ADVECT NORTHWARD. LONGER TERM (TUE ONWARD)...NAM STILL ADVOCATES A TIGHTER BAROCLINIC BOUNDARY SETTING UP OVER ND ON TUE. OTHER MODELS KEEP IT FARTHER NORTH ESPECIALLY NORTHEAST OF A LOW THEY INSIST ON DEVELOPING IN EASTERN MT. AM STILL NOT CONVINCED THE NAM IS WRONG AND IF NOT THEN WE HAVE AN INCREASED THREAT OF SEVERE STORMS TUE NIGHT AS THE LOW LEVEL JET NOSES OVER THE BAROCLINIC ZONE WITH A DECENT JET COUPLET. MOST THREAT PROBABLY NEAR AND NORTH OF INTERSTATE 90. LIKE THE IDEA OF INCREASING POPS DURING THIS TIME AND ACCEPTED HPC QPF GRIDS FOR THIS PERIOD BUT HAVE NOT SUGGESTED SEVERE. BEYOND THIS TIME HAVE LITTLE CONFIDENCE IN MODEL CHOICES STILL AND MADE FEW CHANGES. EUROPEAN STILL SEEMS TO BE PERFORMING WELL AND ITS 00Z RUN SUGGESTS DRYING US OUT BEYOND THU IN CONTRAST TO GFS SWEEPING SIGNIFICANT QPF ACROSS THE AREA DURING THESE DAYS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ JDS nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 204 PM EDT MON AUG 15 2005 .AVIATION (18Z-18Z)... WAVY BOUNDARY REMAINS ACROSS SOUTHERN OH/IN. SATELLITE IMAGERY DEPICTS WEAK CIRCULATION MOVING INTO SOUTHWEST OHIO CURRENTLY...WHICH IS HELPING TO PRODUCE A SLIGHT ENHANCEMENT TO THE -SHRA/DZ. STRONGER WAVE EVIDENT ON WATER VAPOR IMAGERY BACK ACROSS MO IS ACCOMPANIED BY A LARGER AREA OF SHOWERS. FOCUSED PRECIP CHANCES IN THE TAFS ON SECOND WAVE...WHICH THE LATEST SHORT RANGE GUIDANCE INDICATES WILL AFFECT THE AREA IN THE 06-12Z TIMEFRAME. WIDESPREAD IFR CIGS/VSBY NORTH OF THE BOUNDARY TODAY...AND EXPECT THIS TO CONTINUE OVERNIGHT. TAFS RELFLECT TREND OF WORSENING CONDITIONS FROM SOUTH TO NORTH OVERNIGHT AS BOUNDARY SLOWLY PUSHES SOUTH. && .PREVIOUS DISCUSSION... (ISSUED 824 AM EDT MON AUG 15 2005) SHORT TERM (REST OF TODAY)... UPDATED FORECAST TO COVER AREA OF SHOWERS ACROSS THE NORTHERN MIAMI VALLEY. UPPED POPS TO LIKELY IN THAT AREA FOR EARLY THIS MORNING. UPPED POPS TO 50 IN DELAWARE...UNION...LICKING. REST OF FORECAST UNCHANGED. SITES PREVIOUS DISCUSSION... (ISSUED 645 AM EDT MON AUG 15 2005) AVIATION (12Z-12Z)... WEAK MID LVL VORT HELPING TO KEEP AREA OF -SHRA GOING ACRS NRN FCST AREA...JUST NORTH OF KDAY AND KCMH. THIS SHOULD PERSIST THRU MID MRNG AND MAY CONTRIBUTE TO PCPN AT THESE TWO TAF SITES. MORE RAIN ACRS SRN ILLINOIS IN ASSOC WITH STRONGER S/WV. THIS FEATURE PROGGED TO TRACK EAST ACRS REGION THIS AFTN. WHILE PCPN IS POSSIBLE AT JUST ABOUT ANY TIME DURING THE TAF FCST...HAVE KEPT KCVG/KLUK/KILN/KLCK DRY THIS MRNG. BRING IN VCSH FOR AFTN AND ERLY EVNG WITH AREAL COVERAGE TO PCPN LIKELY TO INCREASE WITH APPROACH OF S/WV. BOTH 06Z GFS AND CURRENT RUC INDCG INSTABILITY WILL BE CONFINED TO AREAS ALONG AND SOUTH OF THE OHIO RIVER THIS AFTN...WHERE SOME SUNSHINE IS EXPECTED. ONLY MENTION OF VCTS WILL BE AT KCVG/KLUK DURING AFTN HOURS. APPEARS THERE WILL BE A BREAK IN PCPN CHANCES LATER THIS EVNG BEFORE ANOTHER S/WV AND SFC LO APPCH FCST AREA AFT 06Z. AC/CU WILL BE IN ABUNDANCE AT ALL TAF SITES THRU FCST PERIOD...WITH LOWERING CIGS/VSBYS LATE TONIGHT. 06Z ETA ALREADY HAVING PROBLEMS RESOLVING ONGOING PCPN. HAVE TRENDED TAF FCST TOWARDS 06Z GFS AND CURRENT RUC AS A RESULT. RYAN PREVIOUS DISCUSSION... (ISSUED 218 AM EDT MON AUG 15 2005) SHORT TERM (TODAY THROUGH WEDNESDAY)... SURFACE ANALYSIS SHOWS NEARLY STATIONARY BOUNDARY ACROSS NORTHERN KENTUCKY. KILN RADAR SHOWING SOME SHOWERS MOVING INTO SWRN FORECAST AREA. SATELLITE IMAGERY SHOW MAINLY CLOUDY SKIES WITH CLOUDS BEING A THINNER ACROSS THE SOUTH. NAM AND GFS ARE IN PRETTY GOOD AGREEMENT SYNOPTICALLY. SURFACE FRONT WILL REMAIN NEAR THE OHIO RIVER. BOTH THE NAM AND GFS SHOW PLENTY OF LIFT WITH MID LEVEL WAVE WORKING IN THE WESTERLY FLOW ALOFT...ESPECIALLY TODAY INTO TONIGHT. SURFACE FRONT THEN TRIES TO PULL TO THE SOUTH OF REGION WITH SURFACE HIGH BUILDING IN. WILL GO CONSERVATIVE WITH POPS TODAY INTO TONIGHT AS MODELS AND GUIDANCE HAS NOT BEEN VERY RELIABLE FOR PIN POINTING PRECIP. THUS NOT GOING TO BUY 00Z RUNS HOOK AND SINKER. BUT WILL NOT IGNORE LATEST RUN AND TRENDS. WILL STICK CLOSE TO MAV FOR LOWS AND TO MET FOR HIGHS. TIPTON LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)... NO SIGNIFICANT CHANGES WERE MADE IN THE EXTENDED. FOR THOUGHTS OF PREVIOUS FORECASTER SEE DISCUSSION BELOW. TIPTON (ISSUED 434 PM EDT SUN AUG 14 2005) LONG TERM (TUESDAY THROUGH SUNDAY)... NAM A LITTLE FARTHER TO THE SOUTH THAN THE GFS WITH THE FRONT ON TUESDAY...BUT BOTH GENERALLY SHOWING IT ALONG OR TO THE SOUTH OF THE OHIO RIVER THROUGH THE DAY. SERIES OF WAVES FORECAST TO RIDE EAST ALONG THE FRONT. MAIN IMPACT WITH THESE SHOULD BE ACROSS THE SOUTH BUT NORTHWARD EXTENT SOMEWHAT IN DOUBT. AS A RESULT...WILL KEEP CHANCE POPS GOING FOR ALL BUT THE FAR NORTH ON TUESDAY AND INDICATE HIGHEST POPS ACROSS THE FAR SOUTH. SOME DISCREPANCIES WITH THE MODELS AS TO HOW FAR SOUTH TO PUSH THE FRONT BUT GENERAL CONSENSUS SEEMS TO INDICATE THAT IT WILL BE FAR ENOUGH SOUTH ON WEDNESDAY TO KEEP FA DRY. HOWEVER...HAVE OPTED TO MAINTAIN A SLIGHT CHANCE ACROSS THE FAR SOUTH AS FARTHER NORTH GFS WOULD PUT OUR SOUTHERN FA RIGHT ON THE EDGE OF PCPN CHANCES. LOOKS LIKE WHAT IS LEFT OF BOUNDARY WILL LIFT BACK NORTH OF THE AREA THROUGH THURSDAY...WITH A SLIGHT CHANCE OF PCPN CONTINUING. MODELS HAVE HAD QUITE A BIT OF INCONSISTENCY WITH HOW FAST TO PUSH NEXT FRONT TOWARD THE AREA FOR THE UPCOMING WEEKEND AND STRENGTH OF SURFACE HIGH BEHIND IT. THINK BEST WAY TO HANDLE IT AT THIS POINT IS TO STICK WITH CONSISTENCY AND GENERALLY GO WITH LOW CHANCE POPS FOR FRIDAY INTO SATURDAY AND THEN TRY TO DRY THINGS OUT FOR SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 824 AM EDT MON AUG 15 2005 .SHORT TERM (REST OF TODAY)... UPDATED FORECAST TO COVER AREA OF SHOWERS ACROSS THE NORTHERN MIAMI VALLEY. UPPED POPS TO LIKELY IN THAT AREA FOR EARLY THIS MORNING. UPPED POPS TO 50 IN DELAWARE...UNION...LICKING. REST OF FORECAST UNCHANGED. SITES && .PREVIOUS DISCUSSION... (ISSUED 645 AM EDT MON AUG 15 2005) AVIATION (12Z-12Z)... WEAK MID LVL VORT HELPING TO KEEP AREA OF -SHRA GOING ACRS NRN FCST AREA...JUST NORTH OF KDAY AND KCMH. THIS SHOULD PERSIST THRU MID MRNG AND MAY CONTRIBUTE TO PCPN AT THESE TWO TAF SITES. MORE RAIN ACRS SRN ILLINOIS IN ASSOC WITH STRONGER S/WV. THIS FEATURE PROGGED TO TRACK EAST ACRS REGION THIS AFTN. WHILE PCPN IS POSSIBLE AT JUST ABOUT ANY TIME DURING THE TAF FCST...HAVE KEPT KCVG/KLUK/KILN/KLCK DRY THIS MRNG. BRING IN VCSH FOR AFTN AND ERLY EVNG WITH AREAL COVERAGE TO PCPN LIKELY TO INCREASE WITH APPROACH OF S/WV. BOTH 06Z GFS AND CURRENT RUC INDCG INSTABILITY WILL BE CONFINED TO AREAS ALONG AND SOUTH OF THE OHIO RIVER THIS AFTN...WHERE SOME SUNSHINE IS EXPECTED. ONLY MENTION OF VCTS WILL BE AT KCVG/KLUK DURING AFTN HOURS. APPEARS THERE WILL BE A BREAK IN PCPN CHANCES LATER THIS EVNG BEFORE ANOTHER S/WV AND SFC LO APPCH FCST AREA AFT 06Z. AC/CU WILL BE IN ABUNDANCE AT ALL TAF SITES THRU FCST PERIOD...WITH LOWERING CIGS/VSBYS LATE TONIGHT. 06Z ETA ALREADY HAVING PROBLEMS RESOLVING ONGOING PCPN. HAVE TRENDED TAF FCST TOWARDS 06Z GFS AND CURRENT RUC AS A RESULT. RYAN PREVIOUS DISCUSSION... (ISSUED 218 AM EDT MON AUG 15 2005) SHORT TERM (TODAY THROUGH WEDNESDAY)... SURFACE ANALYSIS SHOWS NEARLY STATIONARY BOUNDARY ACROSS NORTHERN KENTUCKY. KILN RADAR SHOWING SOME SHOWERS MOVING INTO SWRN FORECAST AREA. SATELLITE IMAGERY SHOW MAINLY CLOUDY SKIES WITH CLOUDS BEING A THINNER ACROSS THE SOUTH. NAM AND GFS ARE IN PRETTY GOOD AGREEMENT SYNOPTICALLY. SURFACE FRONT WILL REMAIN NEAR THE OHIO RIVER. BOTH THE NAM AND GFS SHOW PLENTY OF LIFT WITH MID LEVEL WAVE WORKING IN THE WESTERLY FLOW ALOFT...ESPECIALLY TODAY INTO TONIGHT. SURFACE FRONT THEN TRIES TO PULL TO THE SOUTH OF REGION WITH SURFACE HIGH BUILDING IN. WILL GO CONSERVATIVE WITH POPS TODAY INTO TONIGHT AS MODELS AND GUIDANCE HAS NOT BEEN VERY RELIABLE FOR PIN POINTING PRECIP. THUS NOT GOING TO BUY 00Z RUNS HOOK AND SINKER. BUT WILL NOT IGNORE LATEST RUN AND TRENDS. WILL STICK CLOSE TO MAV FOR LOWS AND TO MET FOR HIGHS. TIPTON LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)... NO SIGNIFICANT CHANGES WERE MADE IN THE EXTENDED. FOR THOUGHTS OF PREVIOUS FORECASTER SEE DISCUSSION BELOW. TIPTON (ISSUED 434 PM EDT SUN AUG 14 2005) LONG TERM (TUESDAY THROUGH SUNDAY)... NAM A LITTLE FARTHER TO THE SOUTH THAN THE GFS WITH THE FRONT ON TUESDAY...BUT BOTH GENERALLY SHOWING IT ALONG OR TO THE SOUTH OF THE OHIO RIVER THROUGH THE DAY. SERIES OF WAVES FORECAST TO RIDE EAST ALONG THE FRONT. MAIN IMPACT WITH THESE SHOULD BE ACROSS THE SOUTH BUT NORTHWARD EXTENT SOMEWHAT IN DOUBT. AS A RESULT...WILL KEEP CHANCE POPS GOING FOR ALL BUT THE FAR NORTH ON TUESDAY AND INDICATE HIGHEST POPS ACROSS THE FAR SOUTH. SOME DISCREPANCIES WITH THE MODELS AS TO HOW FAR SOUTH TO PUSH THE FRONT BUT GENERAL CONSENSUS SEEMS TO INDICATE THAT IT WILL BE FAR ENOUGH SOUTH ON WEDNESDAY TO KEEP FA DRY. HOWEVER...HAVE OPTED TO MAINTAIN A SLIGHT CHANCE ACROSS THE FAR SOUTH AS FARTHER NORTH GFS WOULD PUT OUR SOUTHERN FA RIGHT ON THE EDGE OF PCPN CHANCES. LOOKS LIKE WHAT IS LEFT OF BOUNDARY WILL LIFT BACK NORTH OF THE AREA THROUGH THURSDAY...WITH A SLIGHT CHANCE OF PCPN CONTINUING. MODELS HAVE HAD QUITE A BIT OF INCONSISTENCY WITH HOW FAST TO PUSH NEXT FRONT TOWARD THE AREA FOR THE UPCOMING WEEKEND AND STRENGTH OF SURFACE HIGH BEHIND IT. THINK BEST WAY TO HANDLE IT AT THIS POINT IS TO STICK WITH CONSISTENCY AND GENERALLY GO WITH LOW CHANCE POPS FOR FRIDAY INTO SATURDAY AND THEN TRY TO DRY THINGS OUT FOR SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SHORT TERM... oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 645 AM EDT MON AUG 15 2005 .AVIATION (12Z-12Z)... WEAK MID LVL VORT HELPING TO KEEP AREA OF -SHRA GOING ACRS NRN FCST AREA...JUST NORTH OF KDAY AND KCMH. THIS SHOULD PERSIST THRU MID MRNG AND MAY CONTRIBUTE TO PCPN AT THESE TWO TAF SITES. MORE RAIN ACRS SRN ILLINOIS IN ASSOC WITH STRONGER S/WV. THIS FEATURE PROGGED TO TRACK EAST ACRS REGION THIS AFTN. WHILE PCPN IS POSSIBLE AT JUST ABOUT ANY TIME DURING THE TAF FCST...HAVE KEPT KCVG/KLUK/KILN/KLCK DRY THIS MRNG. BRING IN VCSH FOR AFTN AND ERLY EVNG WITH AREAL COVERAGE TO PCPN LIKELY TO INCREASE WITH APPROACH OF S/WV. BOTH 06Z GFS AND CURRENT RUC INDCG INSTABILITY WILL BE CONFINED TO AREAS ALONG AND SOUTH OF THE OHIO RIVER THIS AFTN...WHERE SOME SUNSHINE IS EXPECTED. ONLY MENTION OF VCTS WILL BE AT KCVG/KLUK DURING AFTN HOURS. APPEARS THERE WILL BE A BREAK IN PCPN CHANCES LATER THIS EVNG BEFORE ANOTHER S/WV AND SFC LO APPCH FCST AREA AFT 06Z. AC/CU WILL BE IN ABUNDANCE AT ALL TAF SITES THRU FCST PERIOD...WITH LOWERING CIGS/VSBYS LATE TONIGHT. 06Z ETA ALREADY HAVING PROBLEMS RESOLVING ONGOING PCPN. HAVE TRENDED TAF FCST TOWARDS 06Z GFS AND CURRENT RUC AS A RESULT. RYAN && .PREVIOUS DISCUSSION... (ISSUED 218 AM EDT MON AUG 15 2005) SHORT TERM (TODAY THROUGH WEDNESDAY)... SURFACE ANALYSIS SHOWS NEARLY STATIONARY BOUNDARY ACROSS NORTHERN KENTUCKY. KILN RADAR SHOWING SOME SHOWERS MOVING INTO SWRN FORECAST AREA. SATELLITE IMAGERY SHOW MAINLY CLOUDY SKIES WITH CLOUDS BEING A THINNER ACROSS THE SOUTH. NAM AND GFS ARE IN PRETTY GOOD AGREEMENT SYNOPTICALLY. SURFACE FRONT WILL REMAIN NEAR THE OHIO RIVER. BOTH THE NAM AND GFS SHOW PLENTY OF LIFT WITH MID LEVEL WAVE WORKING IN THE WESTERLY FLOW ALOFT...ESPECIALLY TODAY INTO TONIGHT. SURFACE FRONT THEN TRIES TO PULL TO THE SOUTH OF REGION WITH SURFACE HIGH BUILDING IN. WILL GO CONSERVATIVE WITH POPS TODAY INTO TONIGHT AS MODELS AND GUIDANCE HAS NOT BEEN VERY RELIABLE FOR PIN POINTING PRECIP. THUS NOT GOING TO BUY 00Z RUNS HOOK AND SINKER. BUT WILL NOT IGNORE LATEST RUN AND TRENDS. WILL STICK CLOSE TO MAV FOR LOWS AND TO MET FOR HIGHS. TIPTON LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)... NO SIGNIFICANT CHANGES WERE MADE IN THE EXTENDED. FOR THOUGHTS OF PREVIOUS FORECASTER SEE DISCUSSION BELOW. TIPTON (ISSUED 434 PM EDT SUN AUG 14 2005) LONG TERM (TUESDAY THROUGH SUNDAY)... NAM A LITTLE FARTHER TO THE SOUTH THAN THE GFS WITH THE FRONT ON TUESDAY...BUT BOTH GENERALLY SHOWING IT ALONG OR TO THE SOUTH OF THE OHIO RIVER THROUGH THE DAY. SERIES OF WAVES FORECAST TO RIDE EAST ALONG THE FRONT. MAIN IMPACT WITH THESE SHOULD BE ACROSS THE SOUTH BUT NORTHWARD EXTENT SOMEWHAT IN DOUBT. AS A RESULT...WILL KEEP CHANCE POPS GOING FOR ALL BUT THE FAR NORTH ON TUESDAY AND INDICATE HIGHEST POPS ACROSS THE FAR SOUTH. SOME DISCREPANCIES WITH THE MODELS AS TO HOW FAR SOUTH TO PUSH THE FRONT BUT GENERAL CONSENSUS SEEMS TO INDICATE THAT IT WILL BE FAR ENOUGH SOUTH ON WEDNESDAY TO KEEP FA DRY. HOWEVER...HAVE OPTED TO MAINTAIN A SLIGHT CHANCE ACROSS THE FAR SOUTH AS FARTHER NORTH GFS WOULD PUT OUR SOUTHERN FA RIGHT ON THE EDGE OF PCPN CHANCES. LOOKS LIKE WHAT IS LEFT OF BOUNDARY WILL LIFT BACK NORTH OF THE AREA THROUGH THURSDAY...WITH A SLIGHT CHANCE OF PCPN CONTINUING. MODELS HAVE HAD QUITE A BIT OF INCONSISTENCY WITH HOW FAST TO PUSH NEXT FRONT TOWARD THE AREA FOR THE UPCOMING WEEKEND AND STRENGTH OF SURFACE HIGH BEHIND IT. THINK BEST WAY TO HANDLE IT AT THIS POINT IS TO STICK WITH CONSISTENCY AND GENERALLY GO WITH LOW CHANCE POPS FOR FRIDAY INTO SATURDAY AND THEN TRY TO DRY THINGS OUT FOR SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 820 PM MDT MON AUG 15 2005 .DISCUSSION...02Z SURFACE ANALYSIS SHOWED RIDGE MOVING EAST OF THE NORTHERN PLAINS WITH WEAK RETURN FLOW OVER THE CWA. LOSS OF SOLAR INSOLATION HAS ALLOWED CU TO DISSIPATE LEAVING MAINLY CLEAR SKIES. EXPECT UPPER RIDGE TO BUILD OVER THE ROCKIES TONIGHT WITH WARM AIR ADVECTION AHEAD OF IT. RUC SUGGESTING ELEVATED ACTIVITY MAY DEVELOP ACROSS SD TONIGHT...BUT MAIN THRUST SHOULD BE EAST OF US. HENCE...HAVE REMOVED EVENING POPS AND LEFT OVERNIGHT DRY. REST OF FORECAST IN FINE SHAPE. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ HELGESON sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1040 AM CDT MON AUG 15 2005 .DISCUSSION... RETURN FLOW WAA HAS BEEN QUITE EFFICIENT IN PRODUCING AREA OF SCT SHRA ACRS NWRN CWA THIS MORNING. STILL QUITE COOL ALFT ON MORNING RAOBS...AND HELPED BY COMPACT UPR WAVE MOVING THRU WRN SD. FOCUS FOR PRECIP HAS NOW SHIFTED ENTIRELY N OF I 90...AND WL FOCUS WITHIN AREA OF MIDLVL CONVERGENCE. DO NOT BUY INTO RUC CONCEPT OF DEVELOPING A LITTLE OUTFLOW BNDRY FROM MORNING/EARLY AFTN CONVECTION WHICH FOCUSUS DEVELOPMENT ALG I 90 BY LATE AFTN. RATHER...WL SUBSCRIBE MORE ON ETA/WRF LOCATION ACRS NERN CWA CLOSER TO UPR WAVE AND LKLY RESTING PLACE OF MID LVL CONVERGENCE...AS DO NOT ANTICIPATE ANYTHING SFC BASED. WL ALSO INCLUDE ISOLD THUNDER WITH SOME STEEPER MID LVL LAPSE RATES UPSTREAM ON UNR RAOB. INCREASED N/S TEMP DIFFERENTIAL THRU THE DAY...AS LOWERED TMPS A NOTCH IN FAR NE AND TEMPERED A BIT ACRS N WITH EXTENSIVE CLOUDS EXPECTED TO LINGER WELL INTO THE AFTN. ACRS PARTS OF NW IA AND FAR SERN SD...INCREASED SUNSHINE SHUD ALLOW CLOSER TO FULL MIXING TMPS TO AT LEAST 900 HPA...AND RAISED A COUPLE DEGREES. && .PREV DISCUSSION... MAIN FORECAST PROBLEM IS TEMPS THROUGH TUESDAY AND THEN CHC FOR THUNDERSTORM WEDNESDAY AND WEDNESDAY NIGHT. EARLY THIS MORNING...MID LEVEL CLOUDS AND SCATTERED LIGHT SHOWERS HAVE DEVELOPED ACROSS CENTRAL SOUTH DAKOTA. THESE SHOWERS ARE EXPECTED TO MOVE NORTHEAST TOWARD HIGHWAY 14. WITH THE MID LEVEL WARM ADVECTION DURING THE MORNING. WITH MOISTURE VERY LIMITED...ESPECIALLY NEAR THE SURFACE...LITTLE IF ANY QPF IS EXPECTED. THE CLOUDS WILL BE ACROSS THE NRN AND WRN CWA THIS MORNING...ALSO SLOWLY LIFTING TO THE NORTHEAST DURING THE MORNING. THIS WILL SLOW THE DIURNAL RISE..ESPECIALLY FROM BKX TOWARD MML. ONLY THE FLOW TURNING SW DURING THE AFTERNOON WILL HELP TEMPS RISE INTO THE MID TO UPPER 70S. TONIGHT AND TUESDAY WILL SEE INCREASING SOUTHERLY FLOW AS LOW PRESSURE DEVELPS OVER THE HIGH PLAINS. A WEAK WAVE MOVING NORTH OF THE CWA MAY PRODUCE SOME CLOUDS IN SW MN BUT ANY PRECIPITATION WILL REMAIN OVER ERN MN TONIGHT. SIMILARLY...AS THE WARM FRONT INTENSIFIES ACROSS NRN SD AND CENTRAL MN...MORE STORMS MAY DEVELOP DURING THE AFTERNOON. AGAIN...THIS MAY MEAN MORE CLOUDS OVER SW MN BUT NO PRECIPITATION IS EXPECTED AS THE WARM FRONT WILL BE NORTH OF THE CWA AND 700 MB TEMPS WILL BE RISING ANY WEAK LIFT DUE TO THE WARM ADVECTION WILL NOT BE ABLE TO OVERCOME THE CAP AS MOISTURE WILL BE LIMITED. WITH INCREASING SRLY FLOW OVERNIGHT...TEMPS WILL BE MUCH WARMER IN MOST LOCALES. ON TUESDAY...MUCH WARMER AIR WILL MOVE OVER ALLOWING TEMPS TO RISE BACK ABOVE NORMAL. TEMPS WILL BE BACK IN THE 90S IN THE WRN CWA WITH 80S ELSEWHERE. ON TUESDAY NIGHT...BOTH THE NAM AND GFS SHOW MOISTURE RETURNING NORTH INTO CENTRAL SD AFTER MIDNIGHT AND LAPSE RATES RISE ABOVE 7 C/KM. THIS RESULTS IN LI/S BELOW -4. THEY ALSO SHOW A WEAK WAVE MOVING NORTHWARD ON THE SRN PERIPHARY OF THE WESTERLIES. WITH WEAK CONVEREGENCE SHOWN ABOVE THE NOCTURNAL INVERSION AND SOME SYNOPTIC SCALE LIFT...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS. BASED UPON TIMING OF WAVE AND INSTABILITY...EXPECT THIS CHANCE TO BE AFTER MIDNIGHT AND CONTINUE INTO WEDNESDAY MORNING NORTH OF I90. THE SURFACE FRONT THEN MOVES INTO CENTRAL SD WEDNESDAY AFTERNOON. WITH ALMOST 2 DAYS OF SRLY FLOW...DEW POINTS SHOULD BE INTO THE MID TO UPPER 60S AND TEMPS WILL ONCE AGAIN RISE TO NEAR 90 DEGREES. A STRONG WAVE IS EXPECTED TO MOVE ACROSS THE AREA WHICH SHOULD ALLOW CONVECTION TO DEVELOP DURING THE LATE AFTERNOON OR EVENING IN CENTRAL SD AND THEN SPREAD EAST OR NORTHEAST. SOME SHEAR...PRIMARILY BELOW 3 KM...EXISTS WEDNESDAY EVENING. HOWEVER...FLOW IS RELATIVELY WEAK SO DESPITE DECENT INSTABILITY...SEVERE RISK APPEARS LIMITED TO THE WRN CWA LATE IN THE DAY. ANY CONVECTION THAT DOES DEVELOP SHOULD MOVE NORTHEAST...MEANING NORTHWEST IOWA WILL HAVE THE LEAST CHC OF PRECIP WEDNESDAY NIGHT. MODELS ARE HINTING THAT STRONGER WAVE OVER THE NRN ROCKIES MAY PREVENT FROPA UNTIL LATE THURSDAY OR EVEN ON FRIDAY. BECAUSE OF THE LARGE UNCERTAINTY THAT HAS EXISTED WITH THE PROPAGATION OF THIS FRONT THE PAST COUPLE OF DAYS WILL NOT MAKE ANY CHANCE TO FORECAST AT THIS TIME. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ CHAPMAN/SCHUMACHER sd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BLACKSBURG VA 844 PM EDT MON AUG 15 2005 .SHORT TERM (REST OF TONIGHT)... CLUSTERS OF SHOWERS/STORMS ASSOCIATED WITH WEAK MID LEVEL WAVES CONTINUING TO MOVE ESE ALONG FRONT STUCK JUST N OF THE AREA THIS EVENING. MSAS AS WELL AS 00Z RAOBS SHOW INSTABILITY REMAINING DECENT ESPECIALLY OVER THE NW CLOSER TO THE FRONT...SO SUSPECT THAT WILL TAKE A WHILE FOR RESIDUAL TSRA TO DIE OUT ACROSS THE N THIS EVENING. HOWEVER THE LATEST WRF INDICATES SHOWERS LINGERING ALONG THE FRONT PAST MIDNIGHT WHILE THE RUC BASICALLY DRY OVERNIGHT. THUS PLAN TO LEAVE IN A LOW CHANCE UP N OVERNIGHT ALTHO IFFY AFTER 02Z WHILE GOING SLIGHT CHANCE TO JUST DRY PARTS OF NW NC WHERE DRIER AIR ALOFT AND LESS INSTABILITY PERSIST. FOG QUITE A BIT LESS LAST NIGHT UNDER MARGINAL FOG STABILITY VALUES...AND WITH SIMILAR CONDITIONS TONIGHT EXPECT MAINLY VALLEYS AND LOCATIONS THAT SAW RAINFALL TO SEE PATCHY COVERAGE. GIVEN SLIGHTLY HIGHER DEWPOINTS TONIGHT...APPEARS NOT A LOT OF CHANGE NEEDED TO CURRENT MUGGY FORECAST LOWS. && .PREVIOUS DISCUSSION... (ISSUED 725 PM EDT MON AUG 15 2005) AVIATION... SHOWERS AND TSTMS BEGINNING TO DIE OUT ACROSS OUR AREA AND CONCENTRATE FURTHER NE. WILL STILL BE A SMALL THREAT THRU THE NIGHT. A LITTLE MORE IFR/LIFR FOG LIKELY TONIGHT WITH LIGHTER WINDS AND HIGHER DWPTS. DEEPER MOISTR DROPPING DOWN AHEAD OF THE COLD FRONT WILL RESULT IN MORE CLOUDS AND A GOOD CHC TO LIKLIHOOD OF TSTMS. SOME MVFR CU CIGS POSSIBLE TMRW...ESP BLF/LWB. PREVIOUS DISCUSSION... (ISSUED 248 PM EDT MON AUG 15 2005) SHORT TERM (TONIGHT THROUGH TUESDAY)... AFTERNOON THUNDERSTORMS HAVE DEVELOPED IN STRONG LOW LEVEL CONVERGENCE ALONG THE BLUE RIDGE IN EXTREME SW VA AND NW NC. THESE STORMS SHOULD CONTINUE PROPAGATING EAST-SOUTHEAST INTO THE NW NC PIEDMONT. LAPS AND MSAS SHOWS ANOTHER AREA OF LOW LEVEL CONVERGENCE ALONG THE BLUE RIDGE FROM THE NEAR THE PEAKS OF OTTER...NORTHEAST INTO NORTHERN VA...WHILE SATELLITE SHOWS BUILDING CUMULUS ACROSS THE APPALACHIANS. IT IS HARD TO PICK THE AREA THAT HAS THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS THIS EVENING...BUT THE MODEL CONSENSUS WOULD BE FOR THE PIEDMONT AREAS AS ANY CONVECTION THAT GETS GOING THIS AFTERNOON WOULD BE MOVING EAST-SOUTHEAST INTO THE PIEDMONT. I HAVE CLOSE TO A 50 PERCENT CHANCE THERE IN THE EVENING...BUT THEN KEPT 40 PERCENT ELSEWHERE. MODELS KEEP THE CONVECTION GOING OVERNIGHT NEAR THE OLD SFC FRONT...SO I KEPT A LOW CHANCE OF SHOWERS ACROSS THE NORTHERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. TUESDAY...A NORTHERN STREAM SHORT WAVE INDUCES A WAVE ALONG THE OLD FRONTAL BOUNDARY...AND BOTH THE GFS AND NAM BRING AN AREA OF SHOWERS/THUNDERSTROMS INTO THE MOUNTAINS IN THE AFTERNOON. I PUT A LIKELY CHANCE INTO SOUTHEAST WEST VIRGINIA AND THE SOUTHWEST VIRGINIA MOUNTAINS...AND A HIGH CHANCE ELSEWHERE. STAYED CLOSE THE WARM OVERNIGHT LOWS THAT WE WERE ALREADY FORECASTING. THE MOS HIGH TEMPERATURES FOR TUESDAY LOOKED A LITTLE COOL UNLESS WE HAVE A LOT OF SKY COVER...SO I RAISED HIGH TEMPERATURES 2 TO 5 DEGREES. LONG TERM (TUESDAY NIGHT THROUGH MONDAY)... THE TREND FOR THE UPCOMING DAYS LOOKS TO BE ONE OF TRANSITIONS FOR THE MAIN CENTERS OF HIGH AND LOW PRESSURE OVER THE UNITED STATES AND CANADA. CURRENTLY THE WEATHER OVER THE SOUTHEAST UNITED STATES IS BEING DOMINATED BY AN AREA OF HIGH PRESSURE SITUATED OFF THE COAST OF SOUTH CAROLINA. HOT...MOIST AND UNSTABLE AIR HAS BEEN ROTATING CLOCKWISE AROUND THIS HIGH AND INTO OUR REGION. THE RESULT HAS BEEN ISOLATED SHOWERS AND STORMS AS THERE HAS NOT BEEN ANY ADDITIONAL FOCUSING MECHANISMS FOR BETTER COVERAGE THAN THAT. HEADING INTO THE WEEKEND THIS HIGH PRESSURE CENTER IS EXPECTED TO RETROGRADE WEST ALONG THE GULF COAST SHORE...AND THEN EVENTUALLY INTO THE SOUTHERN CENTRAL PLAINS STATES. AS THIS IS TAKING PLACE...LOW PRESSURE CENTERS IN CANADA WILL HAVE BETTER OPPORTUNITY TO BOTH INTENSIFY OVER THE NORTHEAST UNITED STATES AND SOUTHEAST CANADA...AND THUS A BETTER CHANCE ALLOWING A COLD FRONT OR COLD FRONTS TO ENTER OR MOVE THROUGH OUR REGION. THE FIRST OF THESE FRONTS IS CURRENTLY SLATED TO STALL SOUTH OF THE AREA TOMORROW EVENING. THIS FEATURE WILL PROVIDE BETTER COVERAGE OF PRECIPITATION ACROSS PRIMARILY THE SOUTHERN HALF OF THE REGION...BUT CHANCES WILL BE ON THE DECLINE AS THE NIGHT PROGRESSES. THEN AGAIN ON WEDNESDAY...THE FRONTS PROXIMITY TO THE SOUTHERN HALF OF THE AREA WILL MEAN THE BEST FOCUS FOR SHOWERS AND STORMS ACROSS NORTHWEST NORTH CAROLINA WITH ONLY ISOLATED ACTIVITY ACROSS CENTRAL VIRGINIA AND SOUTHEAST WEST VIRGINIA. THIS FRONT WILL CONTINUE TO BE STALLED JUST SOUTHWEST OF THE REGION HEADING INTO FRIDAY...SO BEST CHANCES OF SHOWERS OF STORMS WILL BE THE AFTERNOON AND EARLY EVENING HOURS OVER NORTHWEST MOUNTAINS OF NORTH CAROLINA. AN EVEN MORE IMPRESSIVE FRONT CURRENTLY IS INDICATED TO PUSH THROUGH THE REGION ON SUNDAY/MONDAY AS AN IMPRESSIVE LOW PRESSURE SYSTEM DEEPENS OVER QUEBEC AND HEADS INTO ONTARIO. TIMING OF THIS FEATURE HAS TENDED SLOWER TODAY THAN PREVIOUS MODEL SOLUTIONS...BUT BEHIND IT LOOKS TO BE SIGNIFICANTLY DRIER...AND COOLER AIR...ASSUMING IT DOES IN FACT MAKE IT THROUGH THE AREA...FOR THE BEGINNING OF NEXT WEEK. AVIATION... SCATTERED CONVECTION HAS ALREADY DEVELOPED ALONG THE BLUE RIDGE IN EXTREME SOUTHWEST VA AND NORTHWEST NORTH CAROLINA. THE MODELS SHOW THIS ORGANIZING SOMEWHAT AND PROPAGATING INTO THE PIEDMONT LATE IN THE AFTERNOON. HOWEVER...SATELLITE SHOWS SOME DEVELOPMENT TO THE CUMULUS CLOUDS ACROSS MUCH OF THE MTNS AND FOOTHILLS...SO I EXPECT AT LEAST SCATTERED THUNDERSTROMS ACROSS THE AREA LATE THIS AFTERNOON AND INTO THIS EVENING. BEST CHC FOR A TSTM WOULD BE LYH AND DAN AT THIS POINT...BUT STILL LESS THAN A 50 PERCENT CHANCE...SO I ONLY INCLUDED VCNTY SHOWERS IN THE THE TAFS. DEPENDING UPON RAINFALL...WE COULD SEE IFR FOG AND STRATUS DEVELOP. I INCLUDED A BRIEF PERIOD TOWARD MORNING FOR LWB...BLF AND DAN. LOOKS LIKE ANOTHER ROUND OF AFTERNOON THUNDERSTROMS FOR THE AREA TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ JH va AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BLACKSBURG VA 138 PM EDT MON AUG 15 2005 .AVIATION... SCATTERED CONVECTION HAS ALREADY DEVELOPED ALONG THE BLUE RIDGE IN EXTREME SOUTHWEST VA AND NORTHWEST NORTH CAROLINA. THE MODELS SHOW THIS ORGANIZING SOMEWHAT AND PROPAGATING INTO THE PIEDMONT LATE IN THE AFTERNOON. HOWEVER...SATELLITE SHOWS SOME DEVELOPMENT TO THE CUMULUS CLOUDS ACROSS MUCH OF THE MTNS AND FOOTHILLS...SO I EXPECT AT LEAST SCATTERED THUNDERSTROMS ACROSS THE AREA LATE THIS AFTERNOON AND INTO THIS EVENING. BEST CHC FOR A TSTM WOULD BE LYH AND DAN AT THIS POINT...BUT STILL LESS THAN A 50 PERCENT CHANCE...SO I ONLY INCLUDED VCNTY SHOWERS IN THE THE TAFS. DEPENDING UPON RAINFALL...WE COULD SEE IFR FOG AND STRATUS DEVELOP. I INCLUDED A BRIEF PERIOD TOWARD MORNING FOR LWB...BLF AND DAN. LOOKS LIKE ANOTHER ROUND OF AFTERNOON THUNDERSTROMS FOR THE AREA TUESDAY. && .PREVIOUS DISCUSSION... (ISSUED 1038 AM EDT MON AUG 15 2005) SHORT TERM (REST OF TODAY THROUGH TONIGHT)... IT IS GETTING HARDER TO FIND WHAT IS LEFT OF THE SURFACE FRONT TO OUR NORTH...BUT USING THE SURFACE EQUIVALENT POTENTIAL TEMPERATURE INDICATES IT EXTENDS ACROSS CEN WV AND INTO EXTREME NRN VA AT THIS TIME AND IS NEARLY STATIONARY. STILL THINKING THAT THIS BOUNDARY WILL PROVIDE A FOCUS FOR MORE ORGANIZED AFTERNOON CONVECTION WHICH COULD IMPACT SOUTHEAST WV AND THE HIGHLANDS OF VA. HOWEVER...BOTH THE RUC AND THE 06 AND 12Z NAM MODELS ARE SHOWING A SECONDARY AREA OF THUNDERSTORM DEVELOPMENT TODAY IN THE LOW LEVEL MOISTURE CONVERGENCE ALONG THE BLUE RIDGE- ESPECIALLY FAR SOUTHWEST VA AND NORTHWEST NORTH CAROLINA. THESE STORMS...IF THEY DEVELOP...WOULD PROPAGATE SOUTHEAST INTO THE PIEDMONT LATE IN THE DAY. THE NORTHWEST FLOW WAS STRONG ENOUGH YESTERDAY TO SUPPRESS MOST THUNDERSTORM DEVELOPMENT IN MY REGION...BUT MODELS SHOW IT WEAKENING THIS AFTERNOON. THE PROBABILITY OF PRECIPITATION /POPS/ IN ALL OF THE MOS OUTPUTS IS ALSO FINALLY A LITTLE HIGHER TODAY. SO...HAVE LEFT CHANCE POPS BUT RAISED CLOSER TO 50 PERCENT ALONG THE BLUE RIDGE IN EXTREME SOUTHWEST VA AND NORTHWEST NC. RAISED POPS TO 40 PERCENT THIS EVENING IN THE PIEDMONT. STORMS WILL BE SLOW MOVING- ESPECIALLY IN THE PIEDMONT SO LOCALLY VERY HEAVY DOWNPOURS ARE LIKELY. MODIFIED SOUNDINGS SHOW CAPES GREATER THAN 3000 J/KG...SO ISOLATED STRONG PULSE STORMS WITH DAMAGING WINDS ARE POSSIBLE. FREEZING LEVELS ARE HIGH ENOUGH THAT LARGE HAIL WOULD BE LESS OF A THREAT. AS FOR HIGH TEMPERATURES...12Z SOUNDINGS INDICATE HIGHS SHOULD BE JUST AS WARM AS THEY HAVE BEEN THE PAST FEW DAYS- AND IT LOOKS LIKE WE WILL HAVE PLENTY OF SUN. THE GREENSBORO SOUNDING IS ACTUALLY A LITTLE WARMER THAN THE PAST FEW DAYS. I HAVE RAISED THE HIGH TEMPERATURE ACROSS THE AREA A FEW DEGREES- SHOULD SEE A LOT OF MID 90S IN THE PIEDMONT TODAY AND WITH HIGH HUMIDITY HEAT IDICES WILL BE AROUND 100. PREVIOUS DISCUSSION... (ISSUED 632 AM EDT MON AUG 15 2005) AVIATION... FROM 11 TO 13 UTC...THERE WILL BE SOME LCL IFR CONDITIONS IN THE MTN VALLEYS WEST OF THE BLUE RIDGE DUE TO FOG NEAR THE RIVERS. ELSEWHERE ONLY LIGHT HAZE WILL BE OBSERVED. THE MORNING FOG SHOULD DISSIPATE BY 14 UTC. WIDELY SCATTERED DEEP CONVECTION WILL DEVELOP DURING THE AFTERNOON... COINCIDING WITH PEAK HEATING. BEST FOCUS FOR ORGANIZED DEEP CONVECTION WILL BE ACROSS WVA WHICH MAY EFFECT BLF/LWB. PREVIOUS DISCUSSION... (ISSUED 334 AM EDT MON AUG 15 2005) SHORT TERM (TODAY)... ANOTHER SULTRY DAY ACROSS THE FCST AREA. NORTHWEST WINDS SHOULD AID DOWNSLOPE ADIABATIC PROCESSES AND COMBINE WITH WARM 85H TEMPS (+21 DEG C) FOR ANOTHER L/M 90 DEG AFTERNOON ALONG AND EAST OF THE BLUE RIDGE. THIS COMBINED WITH DEWPOINTS AROUND 70 SHOULD YIELD HEAT INDICIES NR 100 FOR DANVILLE. MTNS WILL ALSO EXPERIENCE ANOTHER VERY WARM DAY...BUT ANTICIPATE MORE IN THE WAY OF AFTNERNOON CU FORMATION THERE PER INCREASE IN LOW LEVEL MOISTURE FROM THE OH VLY. POP THREAT THIS AFTERNOON LOOKS TO BE HIGHEST ACROSS WVA. SFC FRONT THAT CURRENTLY RUNS ALONG MASON DIXON...THEN SW ALONG OH RIVER...WILL BE FOCUS FOR AFTN THUNDERSTORMS. ORGANIZED THUNDERSTORMS WHICH FORM ALONG THIS BOUNDARY MAY VERY WELL THREATEN PARTS OF OUR NORTHWESTERN CWA LATER IN THE DAY. ELSEWHERE FORCING APPEARS TO BE LIMITED...ALTHOUGH WILL KEEP POPS IN LOW CHC RANGE PER POTENTIAL FOR SINGLE CELL DEVELOPMENT FROM MOUNTAIN DIFFERENCIAL HEATING. ANOTHER AREA TO WATCH FOR POTENTIAL TSTM DEVELOPMENT IS THE THERMAL TROF WHICH WILL BE INDUCED EAST OF THE MTNS FROM THE HEAT. THIS LEE TROF MAY PRODUCE ENOUGH LIFT FOR DEEP CONVECTION THERE. BOTTOM LINE...ENTIRE FCST AREA SUBJECT TO CHC AFTN TSTM...HIGHEST POPS IN OUR WVA COUNTIES PER ANTICIPATED ORGANIZED DEVELOPMENT ALONG FRONTAL BOUNDARY. LONG TERM (TONIGHT THROUGH SUNDAY)... MODELS FAIRLY CONSISTENT WITH SFC FRONT TO OUR NORTH MAKING A RUN FOR US ON TUESDAY. THE NAM BRINGS FRONT INTO AREA LATE IN THE DAY WITH NORTHEAST LOW LEVEL FLOW DEVELOPING ACROSS THE AREA TUESDAY NIGHT AND INTO WEDNESDAY. WITH FRONT OVER THE AREA...ANTICIPATE HIGHEST CONVECTIVE THREAT AT THAT TIME. SINCE FRONT APPEARS THAT IT WILL NOT ARRIVE UNTIL LATE IN THE DAY...BUMPED TUESDAYS TMAX UPWARD A FEW DEGREES FROM PREVIOUS FCST...ESP SOUTHERN CWA. NO CHANGES MADE BEYOND TUESDAY. FRONT IS EXPECTED TO STALL...SO UNCERTAINTY EXISTS ON HOW MUCH OF A POP IS NEEDED FOR THE REMAINDER OF THE WEEK. TEMP FCST ALSO APPEARS TO BE A BIT TRICKY...ALL FCST ELEMENTS HIGHLY DEPENDANT ON PROXIMITY OF FRONT AT THAT TIME. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ JJ va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 1038 AM EDT MON AUG 15 2005 .SHORT TERM (REST OF TODAY THROUGH TONIGHT)... IT IS GETTING HARDER TO FIND WHAT IS LEFT OF THE SURFACE FRONT TO OUR NORTH...BUT USING THE SURFACE EQUIVALENT POTENTIAL TEMPERATURE INDICATES IT EXTENDS ACROSS CEN WV AND INTO EXTREME NRN VA AT THIS TIME AND IS NEARLY STATIONARY. STILL THINKING THAT THIS BOUNDARY WILL PROVIDE A FOCUS FOR MORE ORGANIZED AFTERNOON CONVECTION WHICH COULD IMPACT SOUTHEAST WV AND THE HIGHLANDS OF VA. HOWEVER...BOTH THE RUC AND THE 06 AND 12Z NAM MODELS ARE SHOWING A SECONDARY AREA OF THUNDERSTORM DEVELOPMENT TODAY IN THE LOW LEVEL MOISTURE CONVERGENCE ALONG THE BLUE RIDGE- ESPECIALLY FAR SOUTHWEST VA AND NORTHWEST NORTH CAROLINA. THESE STORMS...IF THEY DEVELOP...WOULD PROPAGATE SOUTHEAST INTO THE PIEDMONT LATE IN THE DAY. THE NORTHWEST FLOW WAS STRONG ENOUGH YESTERDAY TO SUPPRESS MOST THUNDERSTORM DEVELOPMENT IN MY REGION...BUT MODELS SHOW IT WEAKENING THIS AFTERNOON. THE PROBABILITY OF PRECIPITATION /POPS/ IN ALL OF THE MOS OUTPUTS IS ALSO FINALLY A LITTLE HIGHER TODAY. SO...HAVE LEFT CHANCE POPS BUT RAISED CLOSER TO 50 PERCENT ALONG THE BLUE RIDGE IN EXTREME SOUTHWEST VA AND NORTHWEST NC. RAISED POPS TO 40 PERCENT THIS EVENING IN THE PIEDMONT. STORMS WILL BE SLOW MOVING- ESPECIALLY IN THE PIEDMONT SO LOCALLY VERY HEAVY DOWNPOURS ARE LIKELY. MODIFIED SOUNDINGS SHOW CAPES GREATER THAN 3000 J/KG...SO ISOLATED STRONG PULSE STORMS WITH DAMAGING WINDS ARE POSSIBLE. FREEZING LEVELS ARE HIGH ENOUGH THAT LARGE HAIL WOULD BE LESS OF A THREAT. AS FOR HIGH TEMPERATURES...12Z SOUNDINGS INDICATE HIGHS SHOULD BE JUST AS WARM AS THEY HAVE BEEN THE PAST FEW DAYS- AND IT LOOKS LIKE WE WILL HAVE PLENTY OF SUN. THE GREENSBORO SOUNDING IS ACTUALLY A LITTLE WARMER THAN THE PAST FEW DAYS. I HAVE RAISED THE HIGH TEMPERATURE ACROSS THE AREA A FEW DEGREES- SHOULD SEE A LOT OF MID 90S IN THE PIEDMONT TODAY AND WITH HIGH HUMIDITY HEAT IDICES WILL BE AROUND 100. && .PREVIOUS DISCUSSION... (ISSUED 632 AM EDT MON AUG 15 2005) AVIATION... FROM 11 TO 13 UTC...THERE WILL BE SOME LCL IFR CONDITIONS IN THE MTN VALLEYS WEST OF THE BLUE RIDGE DUE TO FOG NEAR THE RIVERS. ELSEWHERE ONLY LIGHT HAZE WILL BE OBSERVED. THE MORNING FOG SHOULD DISSIPATE BY 14 UTC. WIDELY SCATTERED DEEP CONVECTION WILL DEVELOP DURING THE AFTERNOON... COINCIDING WITH PEAK HEATING. BEST FOCUS FOR ORGANIZED DEEP CONVECTION WILL BE ACROSS WVA WHICH MAY EFFECT BLF/LWB. PREVIOUS DISCUSSION... (ISSUED 334 AM EDT MON AUG 15 2005) SHORT TERM (TODAY)... ANOTHER SULTRY DAY ACROSS THE FCST AREA. NORTHWEST WINDS SHOULD AID DOWNSLOPE ADIABATIC PROCESSES AND COMBINE WITH WARM 85H TEMPS (+21 DEG C) FOR ANOTHER L/M 90 DEG AFTERNOON ALONG AND EAST OF THE BLUE RIDGE. THIS COMBINED WITH DEWPOINTS AROUND 70 SHOULD YIELD HEAT INDICIES NR 100 FOR DANVILLE. MTNS WILL ALSO EXPERIENCE ANOTHER VERY WARM DAY...BUT ANTICIPATE MORE IN THE WAY OF AFTNERNOON CU FORMATION THERE PER INCREASE IN LOW LEVEL MOISTURE FROM THE OH VLY. POP THREAT THIS AFTERNOON LOOKS TO BE HIGHEST ACROSS WVA. SFC FRONT THAT CURRENTLY RUNS ALONG MASON DIXON...THEN SW ALONG OH RIVER...WILL BE FOCUS FOR AFTN THUNDERSTORMS. ORGANIZED THUNDERSTORMS WHICH FORM ALONG THIS BOUNDARY MAY VERY WELL THREATEN PARTS OF OUR NORTHWESTERN CWA LATER IN THE DAY. ELSEWHERE FORCING APPEARS TO BE LIMITED...ALTHOUGH WILL KEEP POPS IN LOW CHC RANGE PER POTENTIAL FOR SINGLE CELL DEVELOPMENT FROM MOUNTAIN DIFFERENCIAL HEATING. ANOTHER AREA TO WATCH FOR POTENTIAL TSTM DEVELOPMENT IS THE THERMAL TROF WHICH WILL BE INDUCED EAST OF THE MTNS FROM THE HEAT. THIS LEE TROF MAY PRODUCE ENOUGH LIFT FOR DEEP CONVECTION THERE. BOTTOM LINE...ENTIRE FCST AREA SUBJECT TO CHC AFTN TSTM...HIGHEST POPS IN OUR WVA COUNTIES PER ANTICIPATED ORGANIZED DEVELOPMENT ALONG FRONTAL BOUNDARY. LONG TERM (TONIGHT THROUGH SUNDAY)... MODELS FAIRLY CONSISTENT WITH SFC FRONT TO OUR NORTH MAKING A RUN FOR US ON TUESDAY. THE NAM BRINGS FRONT INTO AREA LATE IN THE DAY WITH NORTHEAST LOW LEVEL FLOW DEVELOPING ACROSS THE AREA TUESDAY NIGHT AND INTO WEDNESDAY. WITH FRONT OVER THE AREA...ANTICIPATE HIGHEST CONVECTIVE THREAT AT THAT TIME. SINCE FRONT APPEARS THAT IT WILL NOT ARRIVE UNTIL LATE IN THE DAY...BUMPED TUESDAYS TMAX UPWARD A FEW DEGREES FROM PREVIOUS FCST...ESP SOUTHERN CWA. NO CHANGES MADE BEYOND TUESDAY. FRONT IS EXPECTED TO STALL...SO UNCERTAINTY EXISTS ON HOW MUCH OF A POP IS NEEDED FOR THE REMAINDER OF THE WEEK. TEMP FCST ALSO APPEARS TO BE A BIT TRICKY...ALL FCST ELEMENTS HIGHLY DEPENDANT ON PROXIMITY OF FRONT AT THAT TIME. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ JJ va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 401 AM MDT TUE AUG 16 2005 .SHORT TERM... (TODAY AND TONIGHT) MAIN SHORT TERM CONCERNS CONTINUE TO BE PRECIP COVERAGE AND INTENSITY WITH PASSING SYSTEM. CURRENT WATER VAPOR IMAGERY AND RUC UPPER ANALYSIS INDICATING WEAK UPPER LEVEL RIDGE AXIS ACROSS EASTERN COLORADO MOVING EAST WITH VIGOROUS UPPER LEVEL LOW ACROSS SOUTHERN NEVADA MOVING ACROSS THE GREAT BASIN REGION. WATER VAPOR IMAGERY ALSO INDICATING 60KT JET CORE ROUNDING BASE OF LOW ACROSS CENTRAL ARIZONA AIDING IN ONGOING CONVECTION ACROSS EASTERN ARIZONA AND UTAH ATTM. AT THE SFC... AMPLE LOW LEVEL MOISTURE REMAINS IN PLACE ACROSS THE REGION... WITH SATELLITE DATA INDICATING SOME PATCHY MVFR STRATUS DEVELOPING ATTM. MSAS DATA AND SFC OBS ALSO INDICATING WEAK LEE TROUGHING DEVELOPING ACROSS THE I-25 CORRIDOR ATTM. TODAY AND TONIGHT...UPPER LOW ACROSS SOUTHERN NEVADA TO WEAKEN AS IT CONTINUES TO MOVE ACROSS THE GREAT BASIN AND INTO THE WESTERN WYOMING TONIGHT...WITH ASSOCIATED JET MOVING INTO WESTERN COLORADO. AMPLE MOISTURE CONTINUES TO BE IN PLACE ACROSS THE REGION...AND WITH INCREASED UVV WITH PASSING SYSTEM...WILL SEE SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE SW AND CENTRAL MTS THIS MORNING...SPREADING ACROSS THE HIGH MT VALLEYS THROUGH THE EASTERN MTS THIS AFTERNOON. ACROSS THE EASTERN PLAINS...SOUTHEASTERLY LOW LEVEL FLOW WILL KEEP AMPLE LOW LEVEL MOISTURE IN PLACE AS WELL... WITH SOUNDINGS INDICATING CAPES BETWEEN 500-1200J/KG THIS AFTERNOON. WITH STRENGTHENING LEE TROUGH AND SOME WEAK QG ASCENT ASSOCIATED WITH JET HAVE INCREASED POPS A TAD ACROSS EASTERN COLORADO AS WELL. BULK SHEARS INCREASE ACROSS THE REGION WITH JET NOSING INTO WESTERN COLORADO THIS AFTERNOON...AND COULD SEE A FEW STRONGER STORMS...PRODUCING SOME SMALL HAIL...GUSTY WINDS AND LOCALLY HEAVY RAIN. HOWEVER SHOULD SEE CONVECTION DIMINISH FROM WEST TO EAST ACROSS THE REGION LATE THIS AFTERNOON AND EVENING...WITH H5 DRY SLOT MOVING INTO THE STATE. -MW .LONG TERM... (WEDNESDAY THROUGH TUESDAY) MAIN FORECAST CHALLENGE WILL BE A COUPLE OF WARM AND RELATIVELY DRY DAYS WED THROUGH FRI...A POTENTIAL COOL DOWN SAT FOR SERN CO...AND THEN BACK TO MODERATING TEMPS AND DRIER WEATHER NEXT WEEK. WED THROUGH FRI...SPLIT FLOW CONTINUES ACROSS THE US WITH THE NRN JET STREAM RUNNING AROUND THE US-CANADIAN BORDER AND THE SRN JET STREAM OVER THE DESERT SW INTO THE CNTRL ROCKIES AND NRN PLAINS. DURING WED AND THU...RELATIVELY DEEP S-SWLY FLOW MIGHT TAP INTO SOME OF THE DRIER UPPER LEVEL AIR OVER THE DESERT SW PER CURRENT WATER VAPOR IMAGERY. HOWEVER...THERE WILL BE ENOUGH MID LEVEL MOISTURE (H7-H5) AND INSTABILITY TO POSSIBLY TRIGGER A FEW SHRA AND TSRA OVER THE HIGH TERRAIN AND DRIFTING E-NEWD GIVEN THE MEAN CLOUD LAYER FLOW. SFC DRYLINE WILL LIKELY GO THROUGH ITS DIURNAL MIGRATION ACROSS ERN CO THANKS TO MIXING AND PBL COOLING. SOUNDINGS SUGGEST INVERTED-V THERMAL STRUCTURE...SO THE MAIN THREAT FROM ANY SHRA OR TSRA WOULD BE LITTLE RAINFALL AND LOCALLY GUSTY WINDS. WITH H7 TEMPS APPROACHING +16C...THIS WOULD TEND TO PROMOTE HIGH TEMPS REACHING INTO THE 90S ACROSS SERN CO. BY FRI...THE NRN AND SRN ULJ STREAMS ARE POTENTIALLY PHASING OVER THE NRN PLAINS. SOME 00Z/16 MODEL DIVERGENCE STARTING TO OCCUR AS GFS80 IS NOT AS AMPLIFIED WITH THE LONGWAVE TROUGH OVER THE NRN ROCKIES AS THE NAM. NAM'S SFC HIGH PRESSURE IS A LITTLE STRONGER THAN THE GFS80. STILL ENOUGH MID LEVEL MOISTURE AND INSTABILITY TO KEEP LOW POPS GOING FOR FRI. SAT...THIS FORECAST PERIOD IS VERY CHALLENGING THIS FAR OUT. GFS80 WANTS TO "BLOW UP" SOME CONVECTIVE SYSTEMS OVER ERN CO/WRN KS INTO RESPONSE TO THE MODEL GENERATING A H5 LOW PRESSURE SYSTEM IN A "COLD POCKET". THE STRENGTH OF SFC COOLING DEPENDS ON HOW STRONG THE CP AIRMASS IS COMING OUT OF CANADA...ANY POST FRONTAL MESOSCALE CONVECTIVE SYSTEMS FORMING...OR IF ANY POST FRONTAL STRATUS/FOG DEVELOPS. 00Z/16 ECMWF IS A LITTLE STRONGER WITH THE SFC HIGH PRESSURE. LOTS OF UNCERTAINTIES. CURRENT FORECAST ALREADY HAS SERN CO SOME 5-10 DEGS COOLER THAN FRI...SO WILL MAINTAIN THE CURRENT FORECAST. SUN THROUGH TUE...IF THE COOL DOWN DOES MATERIALIZE...THEN IT WILL LIKELY BE SHORT LIVED WITH A MODERATING TEMP TREND AND LESS POTENTIAL FOR RELATIVELY DRIER CONDITIONS. [METZE] && .PUB WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 23/17 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 422 AM EDT TUE AUG 16 2005 .SHORT TERM..TODAY AND TONIGHT... STATIONARY FRONT EXTENDS ACROSS NORTHERN KY THROUGH CENTRAL VA TO THE SOUTHERN TIP OF THE DELMARVA PENINSULA AT 06Z. LEANING TOWARD THE 00Z NAM AND 06Z RUC SOLUTIONS FOR TODAY AND TONIGHT...AS THE GFS LOOKS TO STRONG WITH THE SHORTWAVE MOVING FROM THE LOWER OH VALLEY ACROSS THE NORTHERN MID ATLANTIC TODAY. MSAS 3 HOUR PRESSURE FALLS INDICATE AN AREA OF SLOWLY FALLING SFC PRESSURE ACROSS EASTERN OH AND CENTRAL AND EASTERN WV THROUGH 08Z...AND RADAR TRENDS BETWEEN 07Z AND 08Z SHOW LIGHT RAIN FILLING IN ACROSS THESE AREAS. NAM AND RUC SHOW A VORTMAX MOVING ACROSS NORTHERN VA AND NORTHERN MD BETWEEN 12Z AND 18Z FOLLOWED BY A SECOND VORTMAX BETWEEN 18Z AND 00Z WEDNESDAY WHICH IS PROGGED TO MOVE ALONG MORE SOUTHERN TRACK ACROSS CENTRAL VA. THIS UPPER LEVEL SUPPORT WILL RESULT IN WEAK WAVES OF LOW PRESSURE FORMING ALONG THE STATIONARY BOUNDARY TODAY THROUGH EARLY EVENING. WILL INCLUDE LIKELY POPS FOR RAIN THROUGH EARLY THIS EVENING AND THEN DECREASE POPS TO CHANCE CATEGORY TONIGHT...AS SFC WAVES OF LOW PRESSURE EXIT TO THE SOUTHEAST AND DRIER AIR FILTERS IN FROM THE NORTH. MOSTLY CLOUDY SKIES TODAY WILL KEEP HIGHS AROUND 80. && .LONG TERM...WEDNESDAY THROUGH MONDAY... HAVE REMOVED MENTION OF POPS TO THE FCST ON WEDNESDAY AND WEDNESDAY NIGHT...WITH FORCING REMAINING TO THE SOUTH AND FAIRLY OBVIOUS SUBSIDENCE AND DRYING WORKING INTO OUR AREA. ON THURSDAY A WEAK S/W MOVES ACROSS THE MID ATLANTIC REGION BUT THE LOW LEVEL RIDGING APPEARS TO HAVE A MORE SUBSTANTIAL HOLD ON THE PATTERN...THEREFORE HAVE BACKED OFF SLIGHTLY ON THE POPS THURSDAY AND THE NEXT MENTION OF PRECIP WILL NOT BE TIL FRIDAY WHEN A STRONGER S/W APPROACHES...AND OVERALL FLOW PATTERN IS MUCH MORE PROGRESSIVE. MEANWHILE A SFC RIDGE REMAINS BLANKETED ACROSS THE REGION AND OVERALL QPF SHOULD REMAIN MINOR IF THIS PATTERN CONTINUES. TEMPS IN THIS EXTENDED RANGE FCST SHOULD BE RELATIVELY CLOSE TO LATE AUGUST NORMALS...MAINLY IN THE MID 80S FOR HIGHS AND MID TO UPPER 60S FOR LOWS. NO OTHER SIGNIFICANT CHANGES NECESSARY ATTM. && .AVIATION... LIGHT RAIN WILL RESULT IN MVFR CIGS AND VSBYS AT BWI/MTN/DCA/IAD/MRB TODAY WITH VFR CIGS AGAIN TONIGHT AFTER 04Z AS DRIER AIR MOVES IN FROM THE NORTH. EXPECT LIFR VSBYS AND CIGS IN FOG AT CHO THROUGH 11Z THIS MORNING...WHEN LIGHT RAIN WILL INITIATE SOME MIXING AND CONDITIONS WILL BECOME IFR. AFTER 13Z MVFR CIGS/VSBYS WILL PREDOMINATE IN LIGHT RAIN AND MIST THROUGH 06Z WEDNESDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SHORT TERM/AVIATION...SMITH LONG TERM...JB md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 353 AM CDT TUE AUG 16 2005 .DISCUSSION...TODAY THROUGH THURSDAY NIGHT CONVECTION CURRENTLY ON RADAR OVER WEST CENTRAL MINNESOTA APPEARS TO BE OVER A 925 MB WIND MAXIMUM AND IN AN AREA OF 850 MB WARM ADVECTION. THE RUC MODEL CONFINES THESE FEATURES TO AREAS JUST WEST OF THE TWIN CITIES AND DAMPENS THEM OUT 15Z THIS MORNING. THE NAM AND GFS MODELS HAVE SIGNIFICANT DIFFERENCES IN THE FORECAST MOVEMENT OF THE APPROACHING COLD FRONT. FAVOR THE GFS SOLUTION WHICH IS NOT AS AGGRESSIVE IN BRINGING THE COLD FRONT DOWN ACROSS OUR FORECAST AREA. THE LATEST SURFACE ANALYSIS SHOWS NO PUSH BEHIND THE COLD FRONT AND THE UPPER LEVEL JET IS EXPECTED TO REMAIN TO OUR NORTH. BEST AREA OF CONVECTION TODAY IS EXPECTED TO REMAIN TO OUR WEST IN HIGH THETA E AIR AND LOW LEVEL FLOW. THE CHANCE OF CONVECTION WILL SPREAD ACROSS THE AREA TONIGHT IN ANTICIPATION OF A MESO SCALE CONVECTIVE COMPLEX DEVELOPING TO OUR WEST BUT THE FRONT WILL LIKELY STALL TO OUR NORTH AND FORECAST LOW LEVEL THETA E ADVECTION IS ALSO TO OUR NORTH. CONVECTION SHOULD BECOME MORE ACTIVE ACROSS OUR COUNTY WARNING AREA WEDNESDAY THROUGH THURSDAY NIGHT AS THE THETA E RIDGE WORKS FROM WEST TO EAST ACROSS THE AREA IN ADVANCE OF THE FRONT THAT SHOULD FINALLY MAKE A MOVE ACROSS THE AREA THURSDAY AND THURSDAY NIGHT. SEVERAL UPPER LEVEL DISTURBANCES MAY TRIGGER THE BEST CHANCE OF CONVECTION AND THESE ARE TIMED TO MOVE OVER THE AREA WEDNESDAY AFTERNOON AND EVENING THEN AGAIN LATE WEDNESDAY NIGHT INTO EARLY THURSDAY. LONGER TERM...FRIDAY THROUGH TUESDAY LATEST RUNS OF BOTH ECMWF AND GFS (12Z AUG 15 AND 00Z AUG 16...RESPECTIVELY) CONTINUE TO SHOW A DEEP 50H CLOSED LOW OVER MANITOBA BY 12Z FRIDAY WITH SOUTHWEST FLOW ALOFT ACROSS THE MPX CWA. CONFIGURATION OF DIFLUENT 1000-500 MB THICKNESSES AND SURFACE PRESSURE FORECAST SUGGEST GOOD CONVECTIVE POTENTIAL ALONG A TRIPLE POINT OCCLUSION. PATTERN IS STRONG FOR THIS TIME OF YEAR AND SUGGESTIVE OF SOME SEVERE WEATHER POTENTIAL ON FRIDAY. WE ARE CURRENTLY CARRYING PRECIP ON FRIDAY WITH NEW MEX FIGURES SUGGESTIVE OF LINGERING PRECIPITATION INTO SATURDAY. HOWEVER...SURROUNDING OFFICES HAVE OPTED TO STAY WITH A DRY FORECAST. HAVE DECIDED TO LINGER THUNDERSTORMS ACROSS OUR SOUTHEAST ZONES INTO FRIDAY NIGHT AND BEEF UP SYSTEM STRENGTH. NEW GFS AND ECMWF TAKE CENTER OF WEEKEND COLD OUTBREAK TO THE NORTH AND EAST OF OUR AREA...WHILE LATEST DGEX DRIVES COLD AIR INTO WISCONSIN WHICH WOULD MEAN A MUCH COLDER WEEKEND. WE WILL STAY WITH THE WARMER SOLUTION FOR THE MOMENT. .MPX WATCHES/WARNINGS/ADVISORIES... .MN...NONE. .WI...NONE. && $$ mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ST LOUIS MO 350 AM CDT TUE AUG 16 2005 .DISCUSSION... QUASI-STATIONARY FRONTAL BOUNDARY STILL DRAPED ACROSS SOUTHERN MISSOURI THIS MORNING. BOUNDARY IS DIFFICULT TO PICK OUT ATTM...BUT THE EFFECTIVE FRONT IS PROBABLY SOMEWHERE ALONG A LINE FROM SPRINGFIELD MO TO FARMINGTON OUT TO EVANSVILLE INDIANA. THERE'S DEFINITELY A NICE CONTRAST BETWEEN AIRMASSES WITH FARMINGTON REPORTING 72/70 AND QUINCY REPORTING 64/63 AT 300 AM. FRONTOGENETICAL PRECIP BAND IS SHOWING UP NICELY ON RADAR STRETCHING FROM CALLAWAY COUNTY THROUGH THE STL METRO INTO SOUTHWEST ILLINOIS. THE RUC SHIFTS THE FRONTOGENESIS A BIT EAST OVER THE NEXT FEW HOURS...SO I'LL LIKELY CALL AN AUDIBLE BEFORE ZONE-TIME FOR MORNING POPS. WILL PROBABLY HAVE TO BUMP UP A BIT OVER EASTERN SECTIONS. NEITHER THE GFS OR THE NAM SHOW MUCH SUPPORT FOR PUSHING THE BOUNDARY ONE WAY OR ANOTHER TODAY SO HAVE KEPT THE STATUS QUO. DIDN'T STRAY TOO FAR FROM GUIDANCE TODAY AS FAR AS POPS GO...WITH CHANCES FROM AROUND VANDALIA TO JEFFERSON CITY AND SOUTHWARD. WITH DRIER AIR TRYING TO FILTER SOUTH OUT OF IOWA...I THINK THE COVERAGE SHOULD BE MORE SCATTERED IN NATURE THAN THE PAST COUPLE OF DAYS...BUT MY CHANCE POPS WILL MOST LIKELY BE TOO DRY SOMEWHERE...AND TOO WET IN OTHER PLACES. HIGH TEMPERATURES WILL OF COURSE DEPEND VERY STRONGLY ON PRECIPITATION. GUIDANCE TEMPS HAVE SHOWN A BIT OF A WARM BIAS OVER THE PAST COUPLE OF DAYS...ESPECIALLY OVER CENTRAL SECTIONS OF THE CWFA. HAVE THEREFORE GONE WITH HIGHS A FEW DEGREES BELOW GUIDANCE TEMPS FOR TODAY...ESPECIALLY WHERE I'VE GOT POPS IN THE FORECAST. ALL GUIDANCE AGREES THAT THE FRONT WILL SAG SOUTH OVERNIGHT TONIGHT...BUT THERE STILL SEEMS TO BE SOME LOW LEVEL FRONTOGENESIS OVER THE SOUTHERN PARTS OF THE CWFA...MUCH LIKE WHAT'S HAPPENING OVER EASTERN MISSOURI AND SOUTHWEST ILLINOIS RIGHT NOW. HAVE KEPT SOME SLIGHT CHANCE POPS GOING FOR TONIGHT OVER SOUTHERN SECTIONS TO ACCOUNT FOR THIS. FRONT FINALLY WASHES OUT ON WEDNESDAY AND WE GET MORE SOUTHERLY FLOW. NAM TRIES TO GET SOME WARM ADVECTION PRECIP GOING LATE WEDNESDAY AFTERNOON ACROSS WESTERN PORTIONS OF THE AREA...WHILE GFS REMAINS DRY. ECMWF AND UKMET TEND TO SUPPORT THE NAM WITH A WEAK SHORTWAVE RIPPLING ALONG INTO EASTERN KANSAS/WESTERN MISSOURI WEDNESDAY AFTERNOON AND WARM ADVECTION/PLENTY OF LOW LEVEL MOISTURE. THINK IT'S ENOUGH FOR SOME SLIGHT CHANCES ON WEDNESDAY AFTERNOON. THE NAM SPAWNS AN MCS OVER THE PLAINS ON WEDNESDAY NIGHT AND PUSHES IT EAST INTO THE AREA ON THURSDAY. GFS IS SIMILAR...BUT THERE LOOKS LIKE A LOT OF CONVECTIVE FEEDBACK IN THEIR SOLUTIONS AT THIS TIME. HAVE OPTED TO BASICALLY TWEAK GOING FORECAST JUST SLIGHTLY TO BLEND WITH SURROUNDING OFFICES AND ADOPT THE WAIT-AND-SEE APPROACH TO CONVECTION WEDNESDAY NIGHT AND THURSDAY. GUIDANCE WARMS US BACK INTO THE UPPER 80S AND LOW 90S BY THURSDAY AND THIS LOOKS REASONABLE...AS LONG AS THE FRONT ACTUALLY WASHES OUT AND WE GET BACK INTO SOUTHERLY FLOW AS DISCUSSED ABOVE. && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ CARNEY mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 516 AM EDT TUE AUG 16 2005 .SHORT TERM (REST OF TODAY THROUGH TONIGHT)... HAVE ADJUSTED MENTION OF PRECIPITATION TO SHOWERS AND ISOLATED THUNDERSTORMS ALL DAY BASED ON CURRENT RADAR AND LIGHTNING DATA. STILL EXPECT SHOWER PROBABILITIES TO DECREASE THIS AFTERNOON AND EVENING AS FRONTAL CONVERGENCE AND LIFT EXIT SOUTHWARD OUT OF THE UPPER OHIO VALLEY. KEPT MAX TEMPERATURES THE SAME TODAY BUT HAVE CONCERNS THESE COULD BE ONLY LOWER TO MID 70S IF COVERAGE OF SHOWERS PERSISTS INTO MIDDAY. && .PREVIOUS DISCUSSION... (ISSUED 312 AM EDT TUE AUG 16 2005) SHORT TERM (TODAY THROUGH THURSDAY NIGHT)... HAVE MENTION OF A CHANCE OF SHOWERS THIS MORNING BASED ON RADAR SHOWING SCATTERED SHOWERS STARTING TO MOVE EASTWARD ACROSS THE UPPER OHIO VALLEY. RUC AND NAM MODELS SHOW INSTABILITY LIMITED THIS MORNING BUT THEN SUFFICIENT FOR THUNDERSTORMS TO DEVELOP THIS AFTERNOON AND EVENING. SO A CHANCE OF SHOWERS AND THUNDERSTORMS KEPT THIS AFTERNOON AND EVENING. AFTER THAT NAM AND GFS MODELS SHOW THE THE CONVERGENCE AND LIFT ASSOCIATED WITH THE SLOWLY SOUTHWARD MOVING COLD FRONT FINALLY EXITING THE UPPER OHIO VALLEY. SO WENT WITH DRY CONDITIONS LATE TONIGHT INTO THURSDAY. FOR TEMPERATURES...FAVORED COOLER GFS MOS VALUES OVER WARMER NAM MOS AS THE GFS MOS VERIFIED BETTER YESTERDAY. LONG TERM (FRIDAY THROUGH MONDAY)... LATEST GFS MODEL RUNS CONTINUES TO FOLLOW TREND OF EARLIER RUNS IN SHOWING THE NEXT OPPORTUNITY OF SHOWERS AND THUNDERSTORMS TO BE FRIDAY INTO SUNDAY. THE INITIAL CHANCE WILL COME WITH THE PASSAGE OF A SHORT WAVE TROUGH EMBEDDED IN A STRENGTHENING WESTERLY UPPER FLOW FRIDAY...COUPLED WITH A SOUTHERLY RETURN FLOW OF GULF MOISTURE AT LOW LEVELS. THIS CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE UNTIL THE PASSAGE OF A STRONG UPPER LEVEL TROUGH ON SUNDAY. EXPECT SOME COOL RELIEF EARLY NEXT WEEK IN THE NORTHWEST FLOW BEHIND THE SURFACE COLD FRONTAL PASSAGE LATE SUNDAY OR EARLY MONDAY. AVIATION... EXPECT GENERALLY P6SM OVC040-050 STRATOCUMULUS TODAY PER LATEST UPWIND SURFACE AND SATELLITE DATA. CONDITIONS CAN DETERIORATE TO 5SM -SHRA BR OVC020 IN THE SCATTERED PRECIPITATION WITH CUMULONIMBUS POSSIBLE WITH INCREASED INSTABILITY DURING PEAK HEATING AFTERNOON HOURS. EXPECT STRATOCUMULUS TO BEGIN DECREASING DURING THE AFTERNOON AND TONIGHT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 312 AM EDT TUE AUG 16 2005 .SHORT TERM (TODAY THROUGH THURSDAY NIGHT)... HAVE MENTION OF A CHANCE OF SHOWERS THIS MORNING BASED ON RADAR SHOWING SCATTERED SHOWERS STARTING TO MOVE EASTWARD ACROSS THE UPPER OHIO VALLEY. RUC AND NAM MODELS SHOW INSTABILITY LIMITED THIS MORNING BUT THEN SUFFICIENT FOR THUNDERSTORMS TO DEVELOP THIS AFTERNOON AND EVENING. SO A CHANCE OF SHOWERS AND THUNDERSTORMS KEPT THIS AFTERNOON AND EVENING. AFTER THAT NAM AND GFS MODELS SHOW THE THE CONVERGENCE AND LIFT ASSOCIATED WITH THE SLOWLY SOUTHWARD MOVING COLD FRONT FINALLY EXITING THE UPPER OHIO VALLEY. SO WENT WITH DRY CONDITIONS LATE TONIGHT INTO THURSDAY. FOR TEMPERATURES...FAVORED COOLER GFS MOS VALUES OVER WARMER NAM MOS AS THE GFS MOS VERIFIED BETTER YESTERDAY. && .LONG TERM (FRIDAY THROUGH MONDAY)... LATEST GFS MODEL RUNS CONTINUES TO FOLLOW TREND OF EARLIER RUNS IN SHOWING THE NEXT OPPORTUNITY OF SHOWERS AND THUNDERSTORMS TO BE FRIDAY INTO SUNDAY. THE INITIAL CHANCE WILL COME WITH THE PASSAGE OF A SHORT WAVE TROUGH EMBEDDED IN A STRENGTHENING WESTERLY UPPER FLOW FRIDAY...COUPLED WITH A SOUTHERLY RETURN FLOW OF GULF MOISTURE AT LOW LEVELS. THIS CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE UNTIL THE PASSAGE OF A STRONG UPPER LEVEL TROUGH ON SUNDAY. EXPECT SOME COOL RELIEF EARLY NEXT WEEK IN THE NORTHWEST FLOW BEHIND THE SURFACE COLD FRONTAL PASSAGE LATE SUNDAY OR EARLY MONDAY. && .AVIATION... EXPECT GENERALLY P6SM OVC040-050 STRATOCUMULUS TODAY PER LATEST UPWIND SURFACE AND SATELLITE DATA. CONDITIONS CAN DETERIORATE TO 5SM -SHRA BR OVC020 IN THE SCATTERED PRECIPITATION WITH CUMULONIMBUS POSSIBLE WITH INCREASED INSTABILITY DURING PEAK HEATING AFTERNOON HOURS. EXPECT STRATOCUMULUS TO BEGIN DECREASING DURING THE AFTERNOON AND TONIGHT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 130 AM EDT TUE AUG 16 2005 .AVIATION... STATIONARY FRONT DRAPED ACROSS S WV/N VA WILL HAVE A COUPLE OF WAVES TRACKING ALONG IT THRU TUE NIGHT. ONE WAVE BROUGHT A FEW SCT TSRA TO THE AREA THIS AFTN/EVENING. THESE STORMS HAVE EXITED THE AREA. WHERE IT RAIN MON AFTN AND MTN/RIVER VALLEYS WILL BE THE BEST AREA TO SEE MVFR/IFR FOG OVERNIGHT. A STRONGER WAVE WILL ENTER THE REGION LATE TUE AFTN BRINGING BETTER AREAL COVERAGE OF TSRA TO THE AREA. THESE STORMS MAY BE SEVERE AND LINGER DEEP INTO TUE NIGHT. COMMS PROBLEMS CONTINUES AT KDAN. WILL ISSUE TAF WITH NO AMENDMENTS SCHEDULED. && .PREVIOUS DISCUSSION... (ISSUED 844 PM EDT MON AUG 15 2005) SHORT TERM (REST OF TONIGHT)... CLUSTERS OF SHOWERS/STORMS ASSOCIATED WITH WEAK MID LEVEL WAVES CONTINUING TO MOVE ESE ALONG FRONT STUCK JUST N OF THE AREA THIS EVENING. MSAS AS WELL AS 00Z RAOBS SHOW INSTABILITY REMAINING DECENT ESPECIALLY OVER THE NW CLOSER TO THE FRONT...SO SUSPECT THAT WILL TAKE A WHILE FOR RESIDUAL TSRA TO DIE OUT ACROSS THE N THIS EVENING. HOWEVER THE LATEST WRF INDICATES SHOWERS LINGERING ALONG THE FRONT PAST MIDNIGHT WHILE THE RUC BASICALLY DRY OVERNIGHT. THUS PLAN TO LEAVE IN A LOW CHANCE UP N OVERNIGHT ALTHO IFFY AFTER 02Z WHILE GOING SLIGHT CHANCE TO JUST DRY PARTS OF NW NC WHERE DRIER AIR ALOFT AND LESS INSTABILITY PERSIST. FOG QUITE A BIT LESS LAST NIGHT UNDER MARGINAL FOG STABILITY VALUES...AND WITH SIMILAR CONDITIONS TONIGHT EXPECT MAINLY VALLEYS AND LOCATIONS THAT SAW RAINFALL TO SEE PATCHY COVERAGE. GIVEN SLIGHTLY HIGHER DEWPOINTS TONIGHT...APPEARS NOT A LOT OF CHANGE NEEDED TO CURRENT MUGGY FORECAST LOWS. PREVIOUS DISCUSSION... (ISSUED 725 PM EDT MON AUG 15 2005) AVIATION... SHOWERS AND TSTMS BEGINNING TO DIE OUT ACROSS OUR AREA AND CONCENTRATE FURTHER NE. WILL STILL BE A SMALL THREAT THRU THE NIGHT. A LITTLE MORE IFR/LIFR FOG LIKELY TONIGHT WITH LIGHTER WINDS AND HIGHER DWPTS. DEEPER MOISTR DROPPING DOWN AHEAD OF THE COLD FRONT WILL RESULT IN MORE CLOUDS AND A GOOD CHC TO LIKLIHOOD OF TSTMS. SOME MVFR CU CIGS POSSIBLE TMRW...ESP BLF/LWB. PREVIOUS DISCUSSION... (ISSUED 248 PM EDT MON AUG 15 2005) SHORT TERM (TONIGHT THROUGH TUESDAY)... AFTERNOON THUNDERSTORMS HAVE DEVELOPED IN STRONG LOW LEVEL CONVERGENCE ALONG THE BLUE RIDGE IN EXTREME SW VA AND NW NC. THESE STORMS SHOULD CONTINUE PROPAGATING EAST-SOUTHEAST INTO THE NW NC PIEDMONT. LAPS AND MSAS SHOWS ANOTHER AREA OF LOW LEVEL CONVERGENCE ALONG THE BLUE RIDGE FROM THE NEAR THE PEAKS OF OTTER...NORTHEAST INTO NORTHERN VA...WHILE SATELLITE SHOWS BUILDING CUMULUS ACROSS THE APPALACHIANS. IT IS HARD TO PICK THE AREA THAT HAS THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS THIS EVENING...BUT THE MODEL CONSENSUS WOULD BE FOR THE PIEDMONT AREAS AS ANY CONVECTION THAT GETS GOING THIS AFTERNOON WOULD BE MOVING EAST-SOUTHEAST INTO THE PIEDMONT. I HAVE CLOSE TO A 50 PERCENT CHANCE THERE IN THE EVENING...BUT THEN KEPT 40 PERCENT ELSEWHERE. MODELS KEEP THE CONVECTION GOING OVERNIGHT NEAR THE OLD SFC FRONT...SO I KEPT A LOW CHANCE OF SHOWERS ACROSS THE NORTHERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. TUESDAY...A NORTHERN STREAM SHORT WAVE INDUCES A WAVE ALONG THE OLD FRONTAL BOUNDARY...AND BOTH THE GFS AND NAM BRING AN AREA OF SHOWERS/THUNDERSTROMS INTO THE MOUNTAINS IN THE AFTERNOON. I PUT A LIKELY CHANCE INTO SOUTHEAST WEST VIRGINIA AND THE SOUTHWEST VIRGINIA MOUNTAINS...AND A HIGH CHANCE ELSEWHERE. STAYED CLOSE THE WARM OVERNIGHT LOWS THAT WE WERE ALREADY FORECASTING. THE MOS HIGH TEMPERATURES FOR TUESDAY LOOKED A LITTLE COOL UNLESS WE HAVE A LOT OF SKY COVER...SO I RAISED HIGH TEMPERATURES 2 TO 5 DEGREES. LONG TERM (TUESDAY NIGHT THROUGH MONDAY)... THE TREND FOR THE UPCOMING DAYS LOOKS TO BE ONE OF TRANSITIONS FOR THE MAIN CENTERS OF HIGH AND LOW PRESSURE OVER THE UNITED STATES AND CANADA. CURRENTLY THE WEATHER OVER THE SOUTHEAST UNITED STATES IS BEING DOMINATED BY AN AREA OF HIGH PRESSURE SITUATED OFF THE COAST OF SOUTH CAROLINA. HOT...MOIST AND UNSTABLE AIR HAS BEEN ROTATING CLOCKWISE AROUND THIS HIGH AND INTO OUR REGION. THE RESULT HAS BEEN ISOLATED SHOWERS AND STORMS AS THERE HAS NOT BEEN ANY ADDITIONAL FOCUSING MECHANISMS FOR BETTER COVERAGE THAN THAT. HEADING INTO THE WEEKEND THIS HIGH PRESSURE CENTER IS EXPECTED TO RETROGRADE WEST ALONG THE GULF COAST SHORE...AND THEN EVENTUALLY INTO THE SOUTHERN CENTRAL PLAINS STATES. AS THIS IS TAKING PLACE...LOW PRESSURE CENTERS IN CANADA WILL HAVE BETTER OPPORTUNITY TO BOTH INTENSIFY OVER THE NORTHEAST UNITED STATES AND SOUTHEAST CANADA...AND THUS A BETTER CHANCE ALLOWING A COLD FRONT OR COLD FRONTS TO ENTER OR MOVE THROUGH OUR REGION. THE FIRST OF THESE FRONTS IS CURRENTLY SLATED TO STALL SOUTH OF THE AREA TOMORROW EVENING. THIS FEATURE WILL PROVIDE BETTER COVERAGE OF PRECIPITATION ACROSS PRIMARILY THE SOUTHERN HALF OF THE REGION...BUT CHANCES WILL BE ON THE DECLINE AS THE NIGHT PROGRESSES. THEN AGAIN ON WEDNESDAY...THE FRONTS PROXIMITY TO THE SOUTHERN HALF OF THE AREA WILL MEAN THE BEST FOCUS FOR SHOWERS AND STORMS ACROSS NORTHWEST NORTH CAROLINA WITH ONLY ISOLATED ACTIVITY ACROSS CENTRAL VIRGINIA AND SOUTHEAST WEST VIRGINIA. THIS FRONT WILL CONTINUE TO BE STALLED JUST SOUTHWEST OF THE REGION HEADING INTO FRIDAY...SO BEST CHANCES OF SHOWERS OF STORMS WILL BE THE AFTERNOON AND EARLY EVENING HOURS OVER NORTHWEST MOUNTAINS OF NORTH CAROLINA. AN EVEN MORE IMPRESSIVE FRONT CURRENTLY IS INDICATED TO PUSH THROUGH THE REGION ON SUNDAY/MONDAY AS AN IMPRESSIVE LOW PRESSURE SYSTEM DEEPENS OVER QUEBEC AND HEADS INTO ONTARIO. TIMING OF THIS FEATURE HAS TENDED SLOWER TODAY THAN PREVIOUS MODEL SOLUTIONS...BUT BEHIND IT LOOKS TO BE SIGNIFICANTLY DRIER...AND COOLER AIR...ASSUMING IT DOES IN FACT MAKE IT THROUGH THE AREA...FOR THE BEGINNING OF NEXT WEEK. AVIATION... SCATTERED CONVECTION HAS ALREADY DEVELOPED ALONG THE BLUE RIDGE IN EXTREME SOUTHWEST VA AND NORTHWEST NORTH CAROLINA. THE MODELS SHOW THIS ORGANIZING SOMEWHAT AND PROPAGATING INTO THE PIEDMONT LATE IN THE AFTERNOON. HOWEVER...SATELLITE SHOWS SOME DEVELOPMENT TO THE CUMULUS CLOUDS ACROSS MUCH OF THE MTNS AND FOOTHILLS...SO I EXPECT AT LEAST SCATTERED THUNDERSTROMS ACROSS THE AREA LATE THIS AFTERNOON AND INTO THIS EVENING. BEST CHC FOR A TSTM WOULD BE LYH AND DAN AT THIS POINT...BUT STILL LESS THAN A 50 PERCENT CHANCE...SO I ONLY INCLUDED VCNTY SHOWERS IN THE THE TAFS. DEPENDING UPON RAINFALL...WE COULD SEE IFR FOG AND STRATUS DEVELOP. I INCLUDED A BRIEF PERIOD TOWARD MORNING FOR LWB...BLF AND DAN. LOOKS LIKE ANOTHER ROUND OF AFTERNOON THUNDERSTROMS FOR THE AREA TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ RCS va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 1030 AM EDT TUE AUG 16 2005 .DISCUSSION... ...RECORD HIGH FOR TODAY IN ORLANDO THREATENED... ...MOST AREAS WILL NOT SEE RAIN TODAY... DATA FROM MORNING WEATHER BALLOON SHOWS MOISTURE CONFINED BELOW 950 MB (2500 FT) WITH DRYING OCCURRING ABOVE THAT. SFC HEATING EARLY THIS MORNING HAS USED THIS LL MOISTURE TO GENERATE CUMULUS CLOUDS BUT DRIER AIR WILL GET MIXED DOWN AND SKIES WILL BECOME MOSTLY SUNNY BY AFTERNOON NEAR THE COAST AS THE SEA BREEZE PUSHES INLAND. PARTLY SUNNY INTERIOR. WATER VAPOR IMAGERY AND RUC40 SHOW VERY DRY AIR IN THE MID LEVELS JUST EAST OF FLORIDA ASSOCD WITH STRONG UPPER HIGH WHICH WILL SPREAD WEST ACROSS THE AREA NEXT COUPLE DAYS. SOME WEAKENING OF THE UPPER HIGH IS EXPECTED SO AMOUNT OF COMPRESSIONAL WARMING AND DRYING WILL LESSEN AS WELL. WARMING AND DRYING ALOFT HAS STABILIZED THE ATMOS CONSIDERABLY AND DESPITE TEMPS REACHING MID 90S ACROSS MUCH OF THE INTERIOR...RAIN CHANCES WILL BE VERY LOW. BEST CHANCE WILL BE THIS EVENING WITH THE COLLISION OF THE EAST AND WEST COAST SEA BREEZE BOUNDARIES EXPECTED OVER LAKE COUNTY. AT BEST A NARROW BAND OF STORMS WILL RESULT WITH OCCASIONAL LIGHTNING STRIKES AND A PERIOD OF HEAVY RAIN BUT ATMOS NOT CONDUCIVE TO PRODUCING DAMAGING WINDS OR HAIL. HEAT INDICES BETWEEN 102 AND 105 THIS AFTN WHICH IS PRETTY TYPICAL FOR AUG BUT THE DURATION WILL BE LONGER THAN USUAL BECAUSE THERE WILL BE LITTLE IF ANY RELIEF IN THE FORM OF SIGNIFICANT CLOUD COVER OR HEAVY RAIN. && .MARINE...SFC RIDGE AXIS N OF THE CAPE WITH SE WINDS 5-10 KNOTS AT BUOY 41009 THIS MORNING. EXPECT E-SE FLOW TO CONTINUE INTO THE AFTERNOON INCREASING TO AROUND 10 KNOTS NEAR THE COAST WITH THE AFTERNOON SEA BREEZE. SEAS 2 FT OR LESS. && .AVIATION...VFR CONDITIONS THROUGH THE AFTN AND OVERNIGHT. SEA BREEZE COLLISION THIS EVENING WILL OCCUR WEST OF MCO/SFB WITH NARROW LINE OF RA AND ISOLD TSRA POSSIBLE. && .CLIMATE...RECORD HIGH FOR TODAY AT MCO (95 IN 1998) WILL LIKELY BE TIED IF NOT BROKEN. SOME OTHER RECORD HIGHS FOR TODAY (THAT WILL LIKELY STAND): DAYTONA BEACH 95 IN 1957 MELBOURNE 96 IN 1957 VERO BEACH 94 IN 1955 && .MLB WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KELLY/VOLKMER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1036 AM EDT TUE AUG 16 2005 .SHORT TERM...REST OF TODAY... 12Z SFC ANALYSIS SHOWS A STATIONARY FRONT EXTENDING FROM CENTRAL VA WESTWARD ALONG THE OH RIVER VALLEY. 1021MB HIGH PRES OVER LOWER MI AND ANOTHER WEAK ANTICYCLONE OVER CENTRAL TN. GOOD SHEAR ALONG THIS BOUNDARY MAY FAVOR A FEW ISO SVR STORMS THIS AFTERNOON. HAVE ALREADY ISSUED MARINE WARNINGS THIS MORNING FOR GUSTY WINDS. BUMPED UP WINDS OVER MUCH OF BAY AND LOWER POTOMAC TO AROUND 10 KTS. THICK CLOUD SHIELD AND GOOD ISENTROPIC LIFT...AS NOTED ON VIS SAT...NAM 305K THETA SFC...ALONG WITH SATURATED 12Z KIAD SOUNDING. ACTIVITY MOSTLY LOCATED ALONG MD/PA BORDER THIS MORNING AND OVER SOUTHERN ZONES. WILL ALSO LOWER HIGH TEMPS A FEW DEGREES. STILL THINKING LIKELY POPS FOR SHRA ACROSS AREA AS 850MB BOUNDARY AND MID LEVEL VORT MAX MOVES EAST OVER AREA. .AVIATION... LOW CEILINGS AND SHRA WILL PREVAIL AT ALL TAF SITES THIS AFTERNOON. HAVE NOTED IFR CEILINGS AT BWI-MTN THIS MORNING. WILL CONTINUE TREND THROUGH THE EVENING. && .PREVIOUS DISCUSSION... (ISSUED 422 AM EDT TUE AUG 16 2005) .SHORT TERM..TODAY AND TONIGHT... STATIONARY FRONT EXTENDS ACROSS NORTHERN KY THROUGH CENTRAL VA TO THE SOUTHERN TIP OF THE DELMARVA PENINSULA AT 06Z. LEANING TOWARD THE 00Z NAM AND 06Z RUC SOLUTIONS FOR TODAY AND TONIGHT...AS THE GFS LOOKS TO STRONG WITH THE SHORTWAVE MOVING FROM THE LOWER OH VALLEY ACROSS THE NORTHERN MID ATLANTIC TODAY. MSAS 3 HOUR PRESSURE FALLS INDICATE AN AREA OF SLOWLY FALLING SFC PRESSURE ACROSS EASTERN OH AND CENTRAL AND EASTERN WV THROUGH 08Z...AND RADAR TRENDS BETWEEN 07Z AND 08Z SHOW LIGHT RAIN FILLING IN ACROSS THESE AREAS. NAM AND RUC SHOW A VORTMAX MOVING ACROSS NORTHERN VA AND NORTHERN MD BETWEEN 12Z AND 18Z FOLLOWED BY A SECOND VORTMAX BETWEEN 18Z AND 00Z WEDNESDAY WHICH IS PROGGED TO MOVE ALONG MORE SOUTHERN TRACK ACROSS CENTRAL VA. THIS UPPER LEVEL SUPPORT WILL RESULT IN WEAK WAVES OF LOW PRESSURE FORMING ALONG THE STATIONARY BOUNDARY TODAY THROUGH EARLY EVENING. WILL INCLUDE LIKELY POPS FOR RAIN THROUGH EARLY THIS EVENING AND THEN DECREASE POPS TO CHANCE CATEGORY TONIGHT...AS SFC WAVES OF LOW PRESSURE EXIT TO THE SOUTHEAST AND DRIER AIR FILTERS IN FROM THE NORTH. MOSTLY CLOUDY SKIES TODAY WILL KEEP HIGHS AROUND 80. && .LONG TERM...WEDNESDAY THROUGH MONDAY... HAVE REMOVED MENTION OF POPS TO THE FCST ON WEDNESDAY AND WEDNESDAY NIGHT...WITH FORCING REMAINING TO THE SOUTH AND FAIRLY OBVIOUS SUBSIDENCE AND DRYING WORKING INTO OUR AREA. ON THURSDAY A WEAK S/W MOVES ACROSS THE MID ATLANTIC REGION BUT THE LOW LEVEL RIDGING APPEARS TO HAVE A MORE SUBSTANTIAL HOLD ON THE PATTERN...THEREFORE HAVE BACKED OFF SLIGHTLY ON THE POPS THURSDAY AND THE NEXT MENTION OF PRECIP WILL NOT BE TIL FRIDAY WHEN A STRONGER S/W APPROACHES...AND OVERALL FLOW PATTERN IS MUCH MORE PROGRESSIVE. MEANWHILE A SFC RIDGE REMAINS BLANKETED ACROSS THE REGION AND OVERALL QPF SHOULD REMAIN MINOR IF THIS PATTERN CONTINUES. TEMPS IN THIS EXTENDED RANGE FCST SHOULD BE RELATIVELY CLOSE TO LATE AUGUST NORMALS...MAINLY IN THE MID 80S FOR HIGHS AND MID TO UPPER 60S FOR LOWS. NO OTHER SIGNIFICANT CHANGES NECESSARY ATTM. && .AVIATION... LIGHT RAIN WILL RESULT IN MVFR CIGS AND VSBYS AT BWI/MTN/DCA/IAD/MRB TODAY WITH VFR CIGS AGAIN TONIGHT AFTER 04Z AS DRIER AIR MOVES IN FROM THE NORTH. EXPECT LIFR VSBYS AND CIGS IN FOG AT CHO THROUGH 11Z THIS MORNING...WHEN LIGHT RAIN WILL INITIATE SOME MIXING AND CONDITIONS WILL BECOME IFR. AFTER 13Z MVFR CIGS/VSBYS WILL PREDOMINATE IN LIGHT RAIN AND MIST THROUGH 06Z WEDNESDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SHORT TERM/AVIATION...SMITH LONG TERM...JB MORNING UPDATE...GUYER md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1150 AM EDT TUE AUG 16 2005 .DISCUSSION... WEAK FRONT MOVING THROUGH THE UPPER GREAT LAKES SPAWNED A FEW SCATTERED TO ISOLATED SHOWERS ACROSS LAKE SUPERIOR AND NORTHERN UPPER MICHIGAN THIS MORNING. AS THE FRONT SAGS SOUTHWARD THROUGH THIS AFTERNOON...SCATTERED TO ISOLATED SHOWERS ARE POSSIBLE AS CONVERGENCE BAND ASSOCIATED WITH THE FRONT INTERACTS WITH MOISTURE AND INSTABILITY FROM DAYTIME HEATING. SURFACE OBS INDICATE TEMPS ALREADY IN THE 70-75 RANGE ACROSS THE SOUTHERN CWA...AND VISIBLE SATELLITE ALSO SHOWS DIURNAL CU STARTING TO BUILD ACROSS NORTHERN WI. NOT RULING OUT AN ISOLATED THUNDERSTORM EITHER AS RUC INDICATES 850MB-700MB LAPSE RATES AROUND 6C/KM AND MUCAPE VALUES AROUND 500 J/KG. EXPECTING HIGHS ACROSS THE SOUTH TO REACH THE 75-80 DEGREE RANGE...WHILE NORTHWESTERLY FLOW ACROSS THE NORTH KEEPS TEMPS DOWN IN THE UPPER 60S TO MIDDLE 70S. THE NORTHWESTERLY FLOW ACROSS LAKE SUPERIOR HAS ALSO CREATED SMALL CRAFT ADVISORY CONDITIONS FOR THE NEARSHORE AREAS FROM MUNISING EASTWARD. MARINE OBS INDICATE 15 TO 25 KT WINDS WITH WAVES AROUND 3 TO 5 FT FOR THE SOUTHEASTERN QUADRANT. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ LAROSA mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RALEIGH NC 914 AM EDT TUE AUG 16 2005 .SHORT TERM (REST OF TODAY)... NO SIGNIFICANT CHANGES TO THE FORECAST ARE PLANNED THIS MORNING. A MCV OVER ERN/CNTRL KY WILL MOVE EAST...AND AS IT REACHES THE DIFFERENTIAL HEATING ZONE OF THE MOUNTAINS...CONVECTION WILL LIKELY DEVELOP AND MOVE EAST INTO THE PIEDMONT THIS EVENING. RUC HAS A GOOD HANDLE ON THIS FEATURE WHILE THE NAM AND GFS VERIFIED POORLY. BEST CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA WILL BE IN THE NORTH...AS REFLECTED IN THE CURRENT FORECAST. 12Z GSO SOUNDING SHOWS PLENTY OF ENERGY AVAILABLE FOR THUNDERSTORMS (CAPE > 3500 J/KG)...WITH A THETA-E DIFFERENCE IN THE LOWEST 300 MB FAVORABLE FOR DAMAGING WIND GUSTS. HAIL THREAT APPEARS MINIMAL GIVEN HIGH FREEZING LEVELS. SEVERE WIND THREAT WILL HAVE TO BE MONITORED THIS AFTERNOON AND EVENING. TEMPERATURES WILL REACH INTO THE LOWER AND MID 90S THIS AFTERNOON WITH THE HEAT INDEX APPROACHING 105. SPS MENTIONING THE HEAT WILL BE CONTINUED. && .PREVIOUS DISCUSSION... (ISSUED 301 AM EDT TUE AUG 16 2005) SHORT TERM (TODAY THROUGH THURSDAY NIGHT)... ANTICYCLONIC FLOW ALOFT EVOLVES INTO FAST WESTERLY FLOW(ZONAL) AND CONTINUES THROUGH THIS PERIOD. THUS STRONGER S/W'S REMAIN NORTH OF THE AREA WITH ONLY A MINOR RIPPLE OR TWO ACROSS THE CWA. AT THE SURFACE...LATEST ANALYSIS INDICATE WEAK TROUGH LINGERING OVER COASTAL PLAIN TODAY...PUSHING SOUTH. THEN COLD FRONT FROM SOUTHERN OHIO VALLEY GRADUALLY HEAD SOUTH TOWARD THE REGION LATER TODAY AND TONIGHT. SO FOR TODAY...SURFACE BOUNDARY IN THE AREA ALONG WITH CONTINUED MOIST/UNSTABLE AIR WILL RESULT IN BETTER CHANCE FOR SHOWER/TSTM ACTIVITY. THEN WEDNESDAY INTO THURSDAY...UNCLEAR/PROBLEMATIC AS TO HOW FAR SOUTH/LOCATION OF FRONTAL BOUNDARY ACROSS THE CWA. GFS PUSHES FRONT SOUTH OF THE AREA LATE WEDNESDAY AS DRIER/STABLE AIR WORKS IN WEDNESDAY NIGHT INTO THURSDAY. NAM SLOWER. THUS TOUGH CALL ON CHANCES FOR SHOWERS/THUNDERSTORMS ON WEDNESDAY. AT THIS POINT WILL CONTINUE POPS IN THE 50 PERCENT RANGE FOR WEDNESDAY. HOWEVER LOOKS LIKE COUPLE WAVES WILL MOVE EAST ALONG BOUNDARY WEDNESDAY AFTERNOON. BOTH MAV/MET INDICATED LIKELY POPS...KEEP HIGH CHANCE FOR AS LOW CONFIDENCE. POPS TAPERING OFF TO LESSER CHANCE WEDNESDAY NIGHT INTO THURSDAY. HIGHEST POPS ACROSS SOUTHERN HALF THURSDAY. ON TEMPERATURES...ANOTHER HOT DAY IN STORE. HEAT INDEX VALUES OVER THE CENTURY MARK...100 TO 105...JUST BELOW ADVISORY CRITERIA. CLOUDS AND CHANCE FOR RAIN WEDNESDAY RESULT IN COOLER TEMPERATURES NORTHERN SECTIONS WARMEST SOUTHERN SECTIONS. LOW TO MID 80S REASONABLE FOR THURSDAY. LONG TERM (FRIDAY THROUGH MONDAY)... NO CHANGES TO CURRENT FORECAST TRENDS. AVIATION... CLEAR SKIES OVERNIGHT WITH VSBY 4-6 MIS IN HAZE AND FOG. 10Z-14Z VSBY LOWERING TO MVFR OCNL IFR IN FOG...EXCEPT RWI AREA WHERE CIGS AND VSBY WILL LOWER TO LIFR. AFTER 14Z SCATTERED TO BROKEN CLOUDS WITH BASES AT 5 THOUSAND FEET/VSBY 5-6 MIS IN HAZE. SCATTERED THUNDERSTORMS POSSIBLE DURING THE LATE AFTERNOON OR EARLY EVENING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DGS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 1109 AM EDT TUE AUG 16 2005 .SHORT TERM (REST OF TODAY)... STATIONARY FRONT REMAINS ACROSS THE EXTREME SOUTHERN PART OF FA. H5 VORT SLIDING UP OH VLY IS DRIVING AREA OF PCPN AROUND CVG. VORT WILL MOVE EAST OF THE FA BY LATE AFTN...BUT UNTIL THEN EXPECT NR CATEGORICAL COVERAGE ACROSS THE SOUTH. FARTHER NORTH DRY AIR ALREADY STARTING TO WORK IN...WITH NW COUNTIES NOW IN THE SUNSHINE. HAVE CREATED A SHARP GRADIENT ON THE PCPN AROUND I-70...DRYING OUT THE NW. LOWERED TEMPS A FEW DEGREES FOR MOST LOCATIONS. CLEZFPILN OUT. SITES && .PREVIOUS DISCUSSION... (ISSUED 825 AM EDT TUE AUG 16 2005) SHORT TERM (REST OF TODAY)... UPDATED TO INCREASE PCPN CHANCE SOUTH OF I-70 TO LIKELY. REST OF FORECAST OKAY RIGHT NOW. WILL KEEP AN EYE ON THINGS FOR A LATE MORNING UPDATE. SITES PREVIOUS DISCUSSION... (ISSUED 634 AM EDT TUE AUG 16 2005) AVIATION (12Z-12Z)... SURFACE ANALYSIS SHOWS NEARLY STATIONARY BOUNDARY JUST SOUTH OF THE OHIO RIVER. SATELLITE IMAGERY AND SURFACE OBS SHOW OVERCAST SKIES. A PATCH OF IFR TO LIFR CIGS HAVE FORMED IN SE INDIANA INTO KCVG. KILN RADAR SHOWS SCATTERED LIGHT RAIN. WILL MAKE ONLY A FEW CHANGES TO CURRENT TAFS. HAVE LINGERED THREAT OF PRECIP FOR KCVG AND KLUK TODAY. NAM AND RUC SHOWING MID LEVEL WAVE AFFECTING ALMOST THROUGH 18Z. KDAY AND KCMH WILL SEE GRADUAL IMPROVEMENT TODAY AS DRIER AIR WORKS IN BEHIND THE COLD FRONT. CIGS WILL IMPROVE FARTHER SOUTH...JUST MORE SLOWLY. TIPTON PREVIOUS DISCUSSION... (ISSUED 349 AM EDT TUE AUG 16 2005) SHORT TERM (TODAY THROUGH THURSDAY NIGHT)... DIFFUSE FRNTL BNDRY LOCATED ACRS CNTRL KY JUST TO SOUTH OF OHIO RIVER. AREA OF -SHRA ASSOCD WITH WEAK MID LVL VORT EXITING EASTERN FCST AREA ATTM. WEAK 300K ISENT LIFT AND MID LVL DEFORMATION APPEAR TO BE AIDING THIS PCPN AREA AS WELL. FURTHER TO WEST...WDLY SCT -SHRA ACRS REMAINDER OF FCST AREA WITH ADDL SHRA ACRS SW INDIANA/WESTERN KY AND SRN ILLINOIS ASSOCD WITH SFC WAVE. SFC WAVE WILL RIDE EAST ALONG BNDRY TODAY MOVING INTO WEST VIRGINIA BY THIS EVNG. MORE WIDESPREAD COVERAGE TO SHRA EXPECTED ACRS SRN 1/2 FCST AREA THIS MRNG AS WAVE APPCHS. NICE LO LVL CONV AXIS ALONG AND SOUTH OF OHIO RIVER THRU MIDDAY WITH HINTS OF A WEAK 850 LLJ. AFOREMENTIONED MID LVL DEFORMATION AXIS SAGS SLOWLY SOUTH ACRS SRN FCST AREA THRU MID AFTN. 90 KT UPR JET TRACKING ACRS LWR GRT LKS TODAY WITH MUCH OF FCST AREA IN RIGHT REAR QUAD. ALL OF THESE FACTORS SHOULD CONTRIBUTE TO FAIRLY WIDESPREAD COVERAGE OF LIGHT TO OCCASIONALLY MODERATE PCPN THIS MRNG ACRS SRN 1/2 FCST AREA. WILL MAINTAIN LKLY POPS ALONG AND SOUTH OF OHIO RIVER TODAY...WITH CHANCE POPS FURTHER NORTH. WILL KEEP THUNDER OUT OF FCST TODAY AS INSTABILITY AXIS REMAINS TO SOUTH OF BNDRY ACRS CNTRL/SRN KY. SCT -SHRA WILL QUICKLY END NORTH OF I-70 THIS MRNG AS HI PRES OVER GRT LKS PUSHES DRIER AIR FURTHER SOUTH. SOUTH OF I-70...PCPN WILL END FROM NW TO SE THIS AFTN AS SFC WAVE PASSES TO SOUTH OF FCST AREA. SHRA MAY LINGER INTO THIS EVNG ACRS NRN KY...BUT ENTIRE FCST AREA SHOULD BE DRY BY MIDNIGHT. EXPECTING PLENTY OF CLOUDS ACRS SRN FCST AREA...WITH POTENTIAL FOR SOME SUN ALONG AND NORTH OF I-70 AS SFC HI BUILDS SOUTH. PTLY CLDY SKIES EXPECTED OVERNIGHT AS FRNTL BNDRY DROPS INTO TN VLY. SFC HI ACRS REGION WED AND SHOULD SEE A PLEASANT DAY WITH GOOD AMOUNT OF SUNSHINE. MODEL SOUNDINGS INDCG STRONG MID LVL CAP DVLPG WHICH SHOULD KEEP CLOUDS TO A MINIMUM. FRNTL BNDRY WILL BEGIN TO LIFT BACK NORTH WED NIGHT AND APPCH FCST AREA THURS AS WARM FRNT. 00Z NAM/GFS SOLNS DISAGREE ON HOW QUICK TO BRING BNDRY BACK NORTH. NAM WANTS TO SHOOT BNDRY ACRS FCST AREA THURS AFTN WHILE GFS HANGS IT BACK UNTIL ERLY FRI. WILL TAKE A COMPROMISE OF TWO SOLNS AND BRING A 20 POP BACK INTO FCST AREA FOR THURS AFTN AS BNDRY APPCHS. LITTLE IN WAY OF FORCING AND MODEL SOUNDINGS CONTINUE TO INDICATE SOME SEMBLANCE OF A MID LVL CAP...SO EXPECT MANY LOCATIONS WILL REMAIN DRY. TEMPS...KEPT CLOSE TO COOLER MAV GUID AS CLOUDS KEPT TEMPS DOWN QUITE A BIT ON MONDAY...ESPECIALLY AT KCMH AND KDAY. AFTN HIGHS BACK INTO THE M80S FOR WED/THURS AND POTENTIALLY WARMER THAN THAT FRI AS FCST AREA GETS BACK INTO WARM HUMID AIRMASS. LOWS WILL BE PLEASANT NEXT TWO NIGHTS...WITH POTENTIAL FOR A FEW U50S IN RURAL LOCALES ACRS NRN FCST AREA. RYAN LONG TERM (FRIDAY THROUGH MONDAY)... ONLY CHANGE TO PREV FCST WAS TO INSERT 20 POPS INTO FCST AREA FOR FRI AFTN. OTHERWISE...APPEARS UPR LVL RIDGE TO EXPAND NORTH INTO REGION FOR FRI/SAT BEFORE STRONG COLD FRONT COOLS TEMPS DOWN FOR LATTER PART OF EXTENDED. PREVIOUS LONG TERM DISCUSSION FOLLOWS BELOW. RYAN PREVIOUS DISCUSSION... (ISSUED 117 AM EDT TUE AUG 16 2005) AVIATION (06Z-06Z)... SURFACE ANALYSIS SHOWS WEAK STATIONARY BOUNDARY JUST SOUTH OF THE OHIO RIVER. KILN RADAR SHOWS SCT -SHRA FROM KCMH DOWN I-71 TO KCVG. ALOFT AT 500 MB WE ARE UNDER WESTERLY FLOW. SEVERAL MID LEVEL WAVES WILL MOVE EAST JUST NORTH OF THE BOUNDARY BRINGING A GOOD CHANCE FOR -SHRA TO TAF SITES. THE NORTHERN SITES WILL SEE THE BEST THREAT BEFORE 12Z WHILE SOUTHERN SITES WILL LAST THROUGH 16Z. CIGS WILL SLOWLY DROP THROUGH 12Z TO AROUND 1 KFT. CIGS WILL MIX UP DURING THE DAY AND SHOULD BE MVFR BY LATE AFTERNOON. TIPTON (ISSUED 355 PM EDT MON AUG 15 2005) PREVIOUS LONG TERM (THURSDAY THROUGH MONDAY)... WRMFNT LIFTS NORTH ACROSS FA ON THU. FA IS WARM SECTORED UNTIL SAT NGT INTO SUNDAY WHEN COLD FRONT DROPS SOUTHEAST OUT OF GREAT LAKES. 06Z AND 12Z GFS ARE ABOUT 6 HOURS QUICKER THAN THE 00Z GFS WITH THE FROPA. WILL GO WITH THE QUICKER TREND. FRONT IS ASSOCIATED WITH A STRONG H5 S/W THAT SWINGS THROUGH THE GREAT LAKES. SIGNIFICANT COOL DOWN BEHIND THE FRONT WITH HIGHS ONLY INTO THE UPPER 70S TO LOWER 80S ON MONDAY. SITES && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SHORT TERM... oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE WILMINGTON OH 825 AM EDT TUE AUG 16 2005 .SHORT TERM (REST OF TODAY)... UPDATED TO INCREASE PCPN CHANCE SOUTH OF I-70 TO LIKELY. REST OF FORECAST OKAY RIGHT NOW. WILL KEEP AN EYE ON THINGS FOR A LATE MORNING UPDATE. SITES && .PREVIOUS DISCUSSION... (ISSUED 634 AM EDT TUE AUG 16 2005) AVIATION (12Z-12Z)... SURFACE ANALYSIS SHOWS NEARLY STATIONARY BOUNDARY JUST SOUTH OF THE OHIO RIVER. SATELLITE IMAGERY AND SURFACE OBS SHOW OVERCAST SKIES. A PATCH OF IFR TO LIFR CIGS HAVE FORMED IN SE INDIANA INTO KCVG. KILN RADAR SHOWS SCATTERED LIGHT RAIN. WILL MAKE ONLY A FEW CHANGES TO CURRENT TAFS. HAVE LINGERED THREAT OF PRECIP FOR KCVG AND KLUK TODAY. NAM AND RUC SHOWING MID LEVEL WAVE AFFECTING ALMOST THROUGH 18Z. KDAY AND KCMH WILL SEE GRADUAL IMPROVEMENT TODAY AS DRIER AIR WORKS IN BEHIND THE COLD FRONT. CIGS WILL IMPROVE FARTHER SOUTH...JUST MORE SLOWLY. TIPTON PREVIOUS DISCUSSION... (ISSUED 349 AM EDT TUE AUG 16 2005) SHORT TERM (TODAY THROUGH THURSDAY NIGHT)... DIFFUSE FRNTL BNDRY LOCATED ACRS CNTRL KY JUST TO SOUTH OF OHIO RIVER. AREA OF -SHRA ASSOCD WITH WEAK MID LVL VORT EXITING EASTERN FCST AREA ATTM. WEAK 300K ISENT LIFT AND MID LVL DEFORMATION APPEAR TO BE AIDING THIS PCPN AREA AS WELL. FURTHER TO WEST...WDLY SCT -SHRA ACRS REMAINDER OF FCST AREA WITH ADDL SHRA ACRS SW INDIANA/WESTERN KY AND SRN ILLINOIS ASSOCD WITH SFC WAVE. SFC WAVE WILL RIDE EAST ALONG BNDRY TODAY MOVING INTO WEST VIRGINIA BY THIS EVNG. MORE WIDESPREAD COVERAGE TO SHRA EXPECTED ACRS SRN 1/2 FCST AREA THIS MRNG AS WAVE APPCHS. NICE LO LVL CONV AXIS ALONG AND SOUTH OF OHIO RIVER THRU MIDDAY WITH HINTS OF A WEAK 850 LLJ. AFOREMENTIONED MID LVL DEFORMATION AXIS SAGS SLOWLY SOUTH ACRS SRN FCST AREA THRU MID AFTN. 90 KT UPR JET TRACKING ACRS LWR GRT LKS TODAY WITH MUCH OF FCST AREA IN RIGHT REAR QUAD. ALL OF THESE FACTORS SHOULD CONTRIBUTE TO FAIRLY WIDESPREAD COVERAGE OF LIGHT TO OCCASIONALLY MODERATE PCPN THIS MRNG ACRS SRN 1/2 FCST AREA. WILL MAINTAIN LKLY POPS ALONG AND SOUTH OF OHIO RIVER TODAY...WITH CHANCE POPS FURTHER NORTH. WILL KEEP THUNDER OUT OF FCST TODAY AS INSTABILITY AXIS REMAINS TO SOUTH OF BNDRY ACRS CNTRL/SRN KY. SCT -SHRA WILL QUICKLY END NORTH OF I-70 THIS MRNG AS HI PRES OVER GRT LKS PUSHES DRIER AIR FURTHER SOUTH. SOUTH OF I-70...PCPN WILL END FROM NW TO SE THIS AFTN AS SFC WAVE PASSES TO SOUTH OF FCST AREA. SHRA MAY LINGER INTO THIS EVNG ACRS NRN KY...BUT ENTIRE FCST AREA SHOULD BE DRY BY MIDNIGHT. EXPECTING PLENTY OF CLOUDS ACRS SRN FCST AREA...WITH POTENTIAL FOR SOME SUN ALONG AND NORTH OF I-70 AS SFC HI BUILDS SOUTH. PTLY CLDY SKIES EXPECTED OVERNIGHT AS FRNTL BNDRY DROPS INTO TN VLY. SFC HI ACRS REGION WED AND SHOULD SEE A PLEASANT DAY WITH GOOD AMOUNT OF SUNSHINE. MODEL SOUNDINGS INDCG STRONG MID LVL CAP DVLPG WHICH SHOULD KEEP CLOUDS TO A MINIMUM. FRNTL BNDRY WILL BEGIN TO LIFT BACK NORTH WED NIGHT AND APPCH FCST AREA THURS AS WARM FRNT. 00Z NAM/GFS SOLNS DISAGREE ON HOW QUICK TO BRING BNDRY BACK NORTH. NAM WANTS TO SHOOT BNDRY ACRS FCST AREA THURS AFTN WHILE GFS HANGS IT BACK UNTIL ERLY FRI. WILL TAKE A COMPROMISE OF TWO SOLNS AND BRING A 20 POP BACK INTO FCST AREA FOR THURS AFTN AS BNDRY APPCHS. LITTLE IN WAY OF FORCING AND MODEL SOUNDINGS CONTINUE TO INDICATE SOME SEMBLANCE OF A MID LVL CAP...SO EXPECT MANY LOCATIONS WILL REMAIN DRY. TEMPS...KEPT CLOSE TO COOLER MAV GUID AS CLOUDS KEPT TEMPS DOWN QUITE A BIT ON MONDAY...ESPECIALLY AT KCMH AND KDAY. AFTN HIGHS BACK INTO THE M80S FOR WED/THURS AND POTENTIALLY WARMER THAN THAT FRI AS FCST AREA GETS BACK INTO WARM HUMID AIRMASS. LOWS WILL BE PLEASANT NEXT TWO NIGHTS...WITH POTENTIAL FOR A FEW U50S IN RURAL LOCALES ACRS NRN FCST AREA. RYAN LONG TERM (FRIDAY THROUGH MONDAY)... ONLY CHANGE TO PREV FCST WAS TO INSERT 20 POPS INTO FCST AREA FOR FRI AFTN. OTHERWISE...APPEARS UPR LVL RIDGE TO EXPAND NORTH INTO REGION FOR FRI/SAT BEFORE STRONG COLD FRONT COOLS TEMPS DOWN FOR LATTER PART OF EXTENDED. PREVIOUS LONG TERM DISCUSSION FOLLOWS BELOW. RYAN PREVIOUS DISCUSSION... (ISSUED 117 AM EDT TUE AUG 16 2005) AVIATION (06Z-06Z)... SURFACE ANALYSIS SHOWS WEAK STATIONARY BOUNDARY JUST SOUTH OF THE OHIO RIVER. KILN RADAR SHOWS SCT -SHRA FROM KCMH DOWN I-71 TO KCVG. ALOFT AT 500 MB WE ARE UNDER WESTERLY FLOW. SEVERAL MID LEVEL WAVES WILL MOVE EAST JUST NORTH OF THE BOUNDARY BRINGING A GOOD CHANCE FOR -SHRA TO TAF SITES. THE NORTHERN SITES WILL SEE THE BEST THREAT BEFORE 12Z WHILE SOUTHERN SITES WILL LAST THROUGH 16Z. CIGS WILL SLOWLY DROP THROUGH 12Z TO AROUND 1 KFT. CIGS WILL MIX UP DURING THE DAY AND SHOULD BE MVFR BY LATE AFTERNOON. TIPTON (ISSUED 355 PM EDT MON AUG 15 2005) PREVIOUS LONG TERM (THURSDAY THROUGH MONDAY)... WRMFNT LIFTS NORTH ACROSS FA ON THU. FA IS WARM SECTORED UNTIL SAT NGT INTO SUNDAY WHEN COLD FRONT DROPS SOUTHEAST OUT OF GREAT LAKES. 06Z AND 12Z GFS ARE ABOUT 6 HOURS QUICKER THAN THE 00Z GFS WITH THE FROPA. WILL GO WITH THE QUICKER TREND. FRONT IS ASSOCIATED WITH A STRONG H5 S/W THAT SWINGS THROUGH THE GREAT LAKES. SIGNIFICANT COOL DOWN BEHIND THE FRONT WITH HIGHS ONLY INTO THE UPPER 70S TO LOWER 80S ON MONDAY. SITES && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 634 AM EDT TUE AUG 16 2005 .AVIATION (12Z-12Z)... SURFACE ANALYSIS SHOWS NEARLY STATIONARY BOUNDARY JUST SOUTH OF THE OHIO RIVER. SATELLITE IMAGERY AND SURFACE OBS SHOW OVERCAST SKIES. A PATCH OF IFR TO LIFR CIGS HAVE FORMED IN SE INDIANA INTO KCVG. KILN RADAR SHOWS SCATTERED LIGHT RAIN. WILL MAKE ONLY A FEW CHANGES TO CURRENT TAFS. HAVE LINGERED THREAT OF PRECIP FOR KCVG AND KLUK TODAY. NAM AND RUC SHOWING MID LEVEL WAVE AFFECTING ALMOST THROUGH 18Z. KDAY AND KCMH WILL SEE GRADUAL IMPROVEMENT TODAY AS DRIER AIR WORKS IN BEHIND THE COLD FRONT. CIGS WILL IMPROVE FARTHER SOUTH...JUST MORE SLOWLY. TIPTON && .PREVIOUS DISCUSSION... (ISSUED 349 AM EDT TUE AUG 16 2005) SHORT TERM (TODAY THROUGH THURSDAY NIGHT)... DIFFUSE FRNTL BNDRY LOCATED ACRS CNTRL KY JUST TO SOUTH OF OHIO RIVER. AREA OF -SHRA ASSOCD WITH WEAK MID LVL VORT EXITING EASTERN FCST AREA ATTM. WEAK 300K ISENT LIFT AND MID LVL DEFORMATION APPEAR TO BE AIDING THIS PCPN AREA AS WELL. FURTHER TO WEST...WDLY SCT -SHRA ACRS REMAINDER OF FCST AREA WITH ADDL SHRA ACRS SW INDIANA/WESTERN KY AND SRN ILLINOIS ASSOCD WITH SFC WAVE. SFC WAVE WILL RIDE EAST ALONG BNDRY TODAY MOVING INTO WEST VIRGINIA BY THIS EVNG. MORE WIDESPREAD COVERAGE TO SHRA EXPECTED ACRS SRN 1/2 FCST AREA THIS MRNG AS WAVE APPCHS. NICE LO LVL CONV AXIS ALONG AND SOUTH OF OHIO RIVER THRU MIDDAY WITH HINTS OF A WEAK 850 LLJ. AFOREMENTIONED MID LVL DEFORMATION AXIS SAGS SLOWLY SOUTH ACRS SRN FCST AREA THRU MID AFTN. 90 KT UPR JET TRACKING ACRS LWR GRT LKS TODAY WITH MUCH OF FCST AREA IN RIGHT REAR QUAD. ALL OF THESE FACTORS SHOULD CONTRIBUTE TO FAIRLY WIDESPREAD COVERAGE OF LIGHT TO OCCASIONALLY MODERATE PCPN THIS MRNG ACRS SRN 1/2 FCST AREA. WILL MAINTAIN LKLY POPS ALONG AND SOUTH OF OHIO RIVER TODAY...WITH CHANCE POPS FURTHER NORTH. WILL KEEP THUNDER OUT OF FCST TODAY AS INSTABILITY AXIS REMAINS TO SOUTH OF BNDRY ACRS CNTRL/SRN KY. SCT -SHRA WILL QUICKLY END NORTH OF I-70 THIS MRNG AS HI PRES OVER GRT LKS PUSHES DRIER AIR FURTHER SOUTH. SOUTH OF I-70...PCPN WILL END FROM NW TO SE THIS AFTN AS SFC WAVE PASSES TO SOUTH OF FCST AREA. SHRA MAY LINGER INTO THIS EVNG ACRS NRN KY...BUT ENTIRE FCST AREA SHOULD BE DRY BY MIDNIGHT. EXPECTING PLENTY OF CLOUDS ACRS SRN FCST AREA...WITH POTENTIAL FOR SOME SUN ALONG AND NORTH OF I-70 AS SFC HI BUILDS SOUTH. PTLY CLDY SKIES EXPECTED OVERNIGHT AS FRNTL BNDRY DROPS INTO TN VLY. SFC HI ACRS REGION WED AND SHOULD SEE A PLEASANT DAY WITH GOOD AMOUNT OF SUNSHINE. MODEL SOUNDINGS INDCG STRONG MID LVL CAP DVLPG WHICH SHOULD KEEP CLOUDS TO A MINIMUM. FRNTL BNDRY WILL BEGIN TO LIFT BACK NORTH WED NIGHT AND APPCH FCST AREA THURS AS WARM FRNT. 00Z NAM/GFS SOLNS DISAGREE ON HOW QUICK TO BRING BNDRY BACK NORTH. NAM WANTS TO SHOOT BNDRY ACRS FCST AREA THURS AFTN WHILE GFS HANGS IT BACK UNTIL ERLY FRI. WILL TAKE A COMPROMISE OF TWO SOLNS AND BRING A 20 POP BACK INTO FCST AREA FOR THURS AFTN AS BNDRY APPCHS. LITTLE IN WAY OF FORCING AND MODEL SOUNDINGS CONTINUE TO INDICATE SOME SEMBLANCE OF A MID LVL CAP...SO EXPECT MANY LOCATIONS WILL REMAIN DRY. TEMPS...KEPT CLOSE TO COOLER MAV GUID AS CLOUDS KEPT TEMPS DOWN QUITE A BIT ON MONDAY...ESPECIALLY AT KCMH AND KDAY. AFTN HIGHS BACK INTO THE M80S FOR WED/THURS AND POTENTIALLY WARMER THAN THAT FRI AS FCST AREA GETS BACK INTO WARM HUMID AIRMASS. LOWS WILL BE PLEASANT NEXT TWO NIGHTS...WITH POTENTIAL FOR A FEW U50S IN RURAL LOCALES ACRS NRN FCST AREA. RYAN LONG TERM (FRIDAY THROUGH MONDAY)... ONLY CHANGE TO PREV FCST WAS TO INSERT 20 POPS INTO FCST AREA FOR FRI AFTN. OTHERWISE...APPEARS UPR LVL RIDGE TO EXPAND NORTH INTO REGION FOR FRI/SAT BEFORE STRONG COLD FRONT COOLS TEMPS DOWN FOR LATTER PART OF EXTENDED. PREVIOUS LONG TERM DISCUSSION FOLLOWS BELOW. RYAN PREVIOUS DISCUSSION... (ISSUED 117 AM EDT TUE AUG 16 2005) AVIATION (06Z-06Z)... SURFACE ANALYSIS SHOWS WEAK STATIONARY BOUNDARY JUST SOUTH OF THE OHIO RIVER. KILN RADAR SHOWS SCT -SHRA FROM KCMH DOWN I-71 TO KCVG. ALOFT AT 500 MB WE ARE UNDER WESTERLY FLOW. SEVERAL MID LEVEL WAVES WILL MOVE EAST JUST NORTH OF THE BOUNDARY BRINGING A GOOD CHANCE FOR -SHRA TO TAF SITES. THE NORTHERN SITES WILL SEE THE BEST THREAT BEFORE 12Z WHILE SOUTHERN SITES WILL LAST THROUGH 16Z. CIGS WILL SLOWLY DROP THROUGH 12Z TO AROUND 1 KFT. CIGS WILL MIX UP DURING THE DAY AND SHOULD BE MVFR BY LATE AFTERNOON. TIPTON (ISSUED 355 PM EDT MON AUG 15 2005) PREVIOUS LONG TERM (THURSDAY THROUGH MONDAY)... WRMFNT LIFTS NORTH ACROSS FA ON THU. FA IS WARM SECTORED UNTIL SAT NGT INTO SUNDAY WHEN COLD FRONT DROPS SOUTHEAST OUT OF GREAT LAKES. 06Z AND 12Z GFS ARE ABOUT 6 HOURS QUICKER THAN THE 00Z GFS WITH THE FROPA. WILL GO WITH THE QUICKER TREND. FRONT IS ASSOCIATED WITH A STRONG H5 S/W THAT SWINGS THROUGH THE GREAT LAKES. SIGNIFICANT COOL DOWN BEHIND THE FRONT WITH HIGHS ONLY INTO THE UPPER 70S TO LOWER 80S ON MONDAY. SITES && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE PITTSBURGH PA 1140 AM EDT TUE AUG 16 2005 .SHORT TERM (REST OF TODAY THROUGH TONIGHT)... AS MAIN AREA OF PRECIPITATION IN ASSOCIATION WITH THE FIRST SHORT WAVE LEAVES THE CWA I WILL DO AN UPDATE TO LOWER THE CAHNCE OF PRECIPITATION OVER THE NORTHERN SECTIONS. ANOTHER WAVE WILL MOVE OVER THE SOUTHERN PORTION OF THE REGION BRINGING MORE RAIN THIS AFTERNOON AND EVENING. CLOUDINESS WILL REMAIN FROM PITTSBURGH SOUTH SO I LOWERED HIGH TEMPS TO ABOUT MID 70S FOR THIS AREA. THE NORTHERN HIGHS (WITH SUNSHINE) MAY ACTUALLY BE HIGHER THAN THE SOUTHERN HIGHS (WITH CLOUDS). && .PREVIOUS DISCUSSION... (ISSUED 516 AM EDT TUE AUG 16 2005) SHORT TERM (REST OF TODAY THROUGH TONIGHT)... HAVE ADJUSTED MENTION OF PRECIPITATION TO SHOWERS AND ISOLATED THUNDERSTORMS ALL DAY BASED ON CURRENT RADAR AND LIGHTNING DATA. STILL EXPECT SHOWER PROBABILITIES TO DECREASE THIS AFTERNOON AND EVENING AS FRONTAL CONVERGENCE AND LIFT EXIT SOUTHWARD OUT OF THE UPPER OHIO VALLEY. KEPT MAX TEMPERATURES THE SAME TODAY BUT HAVE CONCERNS THESE COULD BE ONLY LOWER TO MID 70S IF COVERAGE OF SHOWERS PERSISTS INTO MIDDAY. PREVIOUS DISCUSSION... (ISSUED 312 AM EDT TUE AUG 16 2005) SHORT TERM (TODAY THROUGH THURSDAY NIGHT)... HAVE MENTION OF A CHANCE OF SHOWERS THIS MORNING BASED ON RADAR SHOWING SCATTERED SHOWERS STARTING TO MOVE EASTWARD ACROSS THE UPPER OHIO VALLEY. RUC AND NAM MODELS SHOW INSTABILITY LIMITED THIS MORNING BUT THEN SUFFICIENT FOR THUNDERSTORMS TO DEVELOP THIS AFTERNOON AND EVENING. SO A CHANCE OF SHOWERS AND THUNDERSTORMS KEPT THIS AFTERNOON AND EVENING. AFTER THAT NAM AND GFS MODELS SHOW THE THE CONVERGENCE AND LIFT ASSOCIATED WITH THE SLOWLY SOUTHWARD MOVING COLD FRONT FINALLY EXITING THE UPPER OHIO VALLEY. SO WENT WITH DRY CONDITIONS LATE TONIGHT INTO THURSDAY. FOR TEMPERATURES...FAVORED COOLER GFS MOS VALUES OVER WARMER NAM MOS AS THE GFS MOS VERIFIED BETTER YESTERDAY. LONG TERM (FRIDAY THROUGH MONDAY)... LATEST GFS MODEL RUNS CONTINUES TO FOLLOW TREND OF EARLIER RUNS IN SHOWING THE NEXT OPPORTUNITY OF SHOWERS AND THUNDERSTORMS TO BE FRIDAY INTO SUNDAY. THE INITIAL CHANCE WILL COME WITH THE PASSAGE OF A SHORT WAVE TROUGH EMBEDDED IN A STRENGTHENING WESTERLY UPPER FLOW FRIDAY...COUPLED WITH A SOUTHERLY RETURN FLOW OF GULF MOISTURE AT LOW LEVELS. THIS CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE UNTIL THE PASSAGE OF A STRONG UPPER LEVEL TROUGH ON SUNDAY. EXPECT SOME COOL RELIEF EARLY NEXT WEEK IN THE NORTHWEST FLOW BEHIND THE SURFACE COLD FRONTAL PASSAGE LATE SUNDAY OR EARLY MONDAY. AVIATION... EXPECT GENERALLY P6SM OVC040-050 STRATOCUMULUS TODAY PER LATEST UPWIND SURFACE AND SATELLITE DATA. CONDITIONS CAN DETERIORATE TO 5SM -SHRA BR OVC020 IN THE SCATTERED PRECIPITATION WITH CUMULONIMBUS POSSIBLE WITH INCREASED INSTABILITY DURING PEAK HEATING AFTERNOON HOURS. EXPECT STRATOCUMULUS TO BEGIN DECREASING DURING THE AFTERNOON AND TONIGHT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ pa AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE WICHITA KS 101 PM CDT TUE AUG 16 2005 .DISCUSSION... WILL FIRE OUT ONE LAST UPDATE TO KEEP UP WITH COMPLEX WEATHER SCENARIO. SHOWERS HAVE PERSISTED THIS MORNING AND EARLY AFTERNOON ALONG A CONVERGENCE/DEFORMATION ZONE WHICH EXTENDS FROM ICT TO NEAR HUT TO GBD. THIS FEATURE IS EVIDENT WHEN LOOKING AT A LOOP OF VIS SATELLITE WHERE MORE ENHANCED CU HAVE PERSISTED. ON TOP OF THIS, A WEAK UPPER WAVE IS STILL LIFTING OUT OF OK AND IS AFFECTING AREA. RUC FORECAST SOUNDING SHOW QUITE A BIT CAPE BELOW 750MB WHICH WOULD EXPLAIN THE SHALLOW NATURE OF THE SHOWERS. SO EXPANDED SHOWERS TO INCLUDE ALL AREAS THROUGH 00Z, BUT LEFT REMAINDER OF THE FORECAST UNCHANGED. && LAWSON .PREV DISCUSSION... /ISSUED 1010 AM CDT TUE AUG 16 2005/ DISCUSSION... WILL PUT OUT A QUICK UPDATE TO ACCOUNT FOR RAIN THAT HAS DEVELOP OVER THE LAST HOUR OR SO. EVEN THOUGH RADAR IS NOT SHOWING MUCH, LOCATIONS NEAR HUT HAVE PICKED CLOSE TO A HALF INCH OF RAIN. IT APPEARS THAT THIS ACTIVITY IS FAIRLY ISOLATED BUT HAS ALSO AFFECTED SOME OF THE WICHITA METRO. THESE SHOWERS ARE DEVELOPING IN RESPONSE TO AN UPPER WAVE THAT IS LIFTING OUT OF NW OKLAHOMA WHICH IS EVIDENT ON WATER VAPOR IMAGERY. SO WILL INSERT A SLIGHT CHANCE FOR RAIN THROUGH AROUND 18Z AND WILL ALSO LOWER TEMPS A BIT SINCE CLOUD COVER SHOULD STICK AROUND A BIT LONGER THAN EXPECTED. LAWSON PREV DISCUSSION... /ISSUED 317 AM CDT TUE AUG 16 2005/ DISCUSSION... TDY-TONIGHT FOG HAS BEEN HELD IN CHECK DUE TO LOW CLOUDS NOT GIVING UP, HOWEVER STRATUS BUILD DOWN EFFECTS COULD STILL CAUSE SOME REDUCED VISIBILITIES EARLY THIS MORNING. TRYING TO CLEAR OUT THESE PESKY LOW CLOUDS ACROSS OUR AREA HAS BEEN A STRUGGLE THE PAST FEW DAYS. MODEL SOUNDINGS STILL INDICATE DECENT MOISTURE REMAINING TRAPPED BELOW AN INVERSION. COMBINE THIS WITH LIMITED MIXING AND THE LOW CLOUDS COULD BECOME RATHER BEARISH ONCE AGAIN, THUS MAKING TEMP FORECASTING TRICKY THIS AFTERNOON. FOG CHANCES/LOCATIONS FOR TONIGHT WILL BE PREDICATED ON BEHAVIOR OF LOW CLOUDS DURING THE DAY AS LOW LEVELS REMAIN MOIST. WE WILL ONLY INSERT PATCHY FOG WORDING AT THIS JUNCTURE AND LET DAYSHIFT INVESTIGATE FURTHER. WED-THUR A NICE WARMING TREND IS IN STORE FOR TEMPS THIS 48HR PERIOD, HOWEVER THURSDAY MIGHT BE A BIT WARMER THEN PREVIOUSLY THOUGHT SO WE WILL RAISE MAXES A BIT FOR THAT DAY. OTHERWISE, THE NEXT SYSTEM IS STILL ON TRACK TO MOVE INTO NEBRASKA/SOUTH DAKOTA REGION ON WED WITH ASSOCIATED JET STREAK. AIRMASS WILL BECOME QUITE UNSTABLE AND SHEAR IS ACTUALLY SUPPORTIVE OF SEVERE THUNDERSTORM ACTIVITY IN WESTERN AND CENTRAL KANSAS. STORMS ARE EXPECTED TO FIRE IN WESTERN SECTIONS OF KANSAS AND NEBRASKA ALONG A SURFACE TROUGH AXIS WED AFTERNOON. SOME OF THIS ACTIVITY COULD AFFECT PORTIONS OF OUR AREA BY LATE WED AFTERNOON OR WED NIGHT. THIS ACTIVITY SHOULD MAINTAIN A EASTWARD TREK WEDNESDAY NIGHT AS THETA-E ADVECTION SUPPLIES THE NECESSARY FUEL. WE WILL CONTINUE TO MONITOR THIS PERIOD FOR ANY SEVERE WEATHER ACTIVITY. EXTENDED: FRI-MON DEPENDING ON THE TIMING OF THE NEXT COLD FRONT, FRIDAY COULD BE THE LAST WARM DAY BEFORE COOLER CANADIAN AIR PUSHES INTO THE REGION FOR THE WEEKEND. WILL KEEP CHANCES OF PRECIP GOING FOR FRIDAY INTO SATURDAY AS A COLD FRONT PUSHES ACROSS KS. TIMING OF THE FRONT IS STILL A BIT UNCERTAIN BUT WILL CONTINUE TO STICK WITH SATURDAY TIMING FOR FRONTAL PASSAGE. BELOW NORMAL TEMPS LOOK TO BE IN STORE FOR THE WEEKEND AND INTO EARLY NEXT WEEK. PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 81 67 88 71 / 10 10 20 30 HUTCHINSON 82 66 88 69 / 10 10 20 30 NEWTON 81 67 87 70 / 10 10 20 30 ELDORADO 80 66 87 69 / 10 10 10 30 WINFIELD-KWLD 82 69 88 70 / 20 20 10 20 RUSSELL 84 65 90 68 / 10 10 30 30 GREAT BEND 84 65 89 69 / 10 10 30 30 SALINA 84 67 90 69 / 10 10 20 30 MCPHERSON 82 65 88 69 / 10 10 20 30 COFFEYVILLE 82 68 87 70 / 20 20 10 20 CHANUTE 79 68 86 71 / 10 20 10 30 IOLA 79 68 86 70 / 10 10 10 30 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ JAKUB/ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 300 PM EDT TUE AUG 16 2005 .DISCUSSION... WITH THE EXCEPTION OF SOME LINGERING SHOWERS CURRENTLY IN THE AREA...THE MAIN FORECAST CONCERN FOR THE NEXT FEW DAYS WILL BE CHANCES FOR SHRA/TSRA FROM LATE TOMORROW THROUGH FRIDAY AS A FEW SHORTWAVES AND FRONTAL BOUNDARIES AFFECT THE AREA. LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES SHOW A SHORTWAVE TO OUR NORTH QUICKLY MOVING EAST THROUGH EASTERN ONTARIO...WITH FAIRLY QUICK WNW UPPER FLOW OVER OUR AREA. THE NEXT FEATURES OF NOTE ARE AN UPPER LOW OVER NEVADA...AND SHORTWAVE ENERGY MOVING INTO BRITISH COLUMBIA. THE UPPER LEVEL PV ANOMALY DRIVING THE NEVADA UPPER LOW WILL MOVE EAST OVER THE NEXT FEW DAYS...AND HELP TO BRING A CHANCE OF PCPN TO OUR AREA LATE TOMORROW INTO THURSDAY...WHILE THE WESTERN CANADA SHORTWAVE WILL COALESCE INTO A MORE SUBSTANTIAL UPPER LOW WHICH WILL TRACK EAST AND IMPACT OUR AREA TOWARD THE WEEKEND. LATEST 88D IMAGERY SHOWS A FEW LONELY SHOWERS MOVING INTO LAKE MICHIGAN AT THIS TIME. THESE SHOWERS DEVELOPED ALONG THE FRONTAL BOUNDARY WHICH CONTINUES TO SAG SOUTH THROUGH THE CWFA AT THIS TIME. TAMDAR SOUNDINGS FROM KSAW LATE THIS MORNING SUGGESTED AROUND 500 J/KG OF CAPE WAS AVAILABLE AHEAD OF THE BOUNDARY...WITH MINIMAL CIN...SO IT APPEARS THAT SOME ACTIVITY WAS ABLE TO TAKE ADVANTAGE OF THIS INSTABILITY. A FEW ADDITIONAL SHOWERS...AND POSSIBLY A THUNDERSTORM...COULD POP UP THROUGH LATE AFTERNOON AS THE BOUNDARY AND LIMITED MID-LEVEL DIFFERENTIAL VORTICITY ADVECTION SINK SOUTH INTO WISCONSIN. EXPECT THE BOUNDARY TO BE OUT OF THE AREA BY THIS EVENING...WITH SUBSIDENCE AND DRIER AIR CONTINUING TO WORK IN...SO WILL GO WITH A DRY FORECAST FOR TONIGHT. AS WE LOOK AHEAD THROUGH THE NEXT FEW DAYS...THERE IS INCREASING DISAGREEMENT THROUGH TIME BETWEEN THE 12Z GFS AND NAM...PRIMARILY STEMMING FROM HOW THEY HANDLE THE UPPER LOW WHICH WILL MOVE OUT OF WESTERN CANADA DURING THE SECOND HALF OF THE WEEK. PREFER THE GFS/S HANDLING OF THIS SYSTEM...SINCE IT HAS BEEN MORE CONSISTENT...IS IN BETTER AGREEMENT WITH THE CANADIAN...UKMET AND ECMWF...AND IS GENERALLY BETTER BEYOND 48 HOURS DUE TO ITS LARGER DOMAIN AND BETTER DATA ASSIMILATION. WILL USE A BLEND OF THE GFS AND NAM THROUGH 24 HOURS OR SO...THEN TREND MUCH MORE TOWARD THE GFS SOLUTION. LOW LEVEL RIDGING WILL BE IN PLACE OVER THE REGION TONIGHT THROUGH WEDNESDAY MORNING...WITH LOW LEVEL RETURN FLOW BEGINNING TO SETUP BY LATE IN THE DAY ON WEDNESDAY. DECENT MID-LEVEL SHORTWAVE RIDGING WILL ARRIVE BY LATER TONIGHT AND REMAIN IN PLACE THROUGH MOST OF WEDNESDAY...WHICH SHOULD HELP TO KEEP THINGS DRY...ALTHOUGH SOME MID AND UPPER CLOUDS WILL LIKELY BEGIN TO SPILL OVER THE RIDGE WEDNESDAY AFTERNOON. MID LEVEL WARM ADVECTION WILL INCREASE BY LATE IN THE DAY WEDNESDAY...PARTICULARLY OVER THE WEST...WHERE SOME ELEVATED INSTABILITY IN COMBINATION WITH THE WARM ADVECTION COULD RESULT IN A FEW SHRA/TSRA. WILL INCLUDE THE MENTION OF A SLIGHT CHANCE OF PCPN OVER THE WEST FOR LATE IN THE DAY ON WEDNESDAY...WHILE LEAVING THE REMAINDER OF THE AREA DRY. THE SHORTWAVE CURRENTLY OVER NEVADA WILL BEGIN TO WORK TOWARD THE CWFA WEDNESDAY NIGHT...WHICH SHOULD PROVIDE SOME MORE MEANINGFUL FORCING FOR PCPN AS WE HEAD THROUGH THE NIGHT. IN ADDITION...EXPECT THE LOW LEVEL SOUTHWESTERLY JET TO INCREASE THROUGH THE NIGHT AS THE 925-700MB GRADIENT TIGHTENS. A LOOK AT THE 850-500MB DIFFERENTIAL THETA-E PROGS SUGGESTS DECENT ELEVATED INSTABILITY WILL MAKE IT INTO THE WESTERN AND CENTRAL CWFA AS WE HEAD THROUGH THE NIGHT...SO WILL MARCH THE CHANCE OF SHRA/TSRA EASTWARD THROUGH THE NIGHT. THE SHORTWAVE AXIS WILL PASS ACROSS THE CWFA DURING THE DAY ON THURSDAY...ALONG WITH A PRE-FRONTAL TROUGH...WHICH SHOULD WORK TO KEEP SOME SHRA/TSRA GOING ACROSS THE AREA. CHANCES FOR PCPN WILL LINGER INTO THURSDAY EVENING UNTIL SUBSIDENCE AND SHORTWAVE RIDGING WORK INTO THE AREA BEHIND THE INITIAL SHORTWAVE. EXPECT THINGS TO DRY OUT SUFFICIENTLY TO ALLOW FOR A DRY PERIOD OF TIME BETWEEN THIS INITIAL SHORTWAVE AND THE MORE SUBSTANTIAL UPPER LOW WHICH WILL TRACK JUST NORTH OF THE US/CANADA BORDER FRIDAY INTO SATURDAY. AS A RESULT...WILL GO WITH A DRY FORECAST FOR PART OF THE DAY ON FRIDAY...BEFORE THE MAIN COLD FRONTAL BOUNDARY AND FORCING ASSOCIATED WITH THE NORTHERN UPPER LOW WORK INTO THE AREA LATE FRIDAY AFTERNOON AND FRIDAY NIGHT. WILL BLANKET THE CWFA WITH A CHANCE OF SHRA/TSRA FRIDAY NIGHT INTO SATURDAY AS THE FRONT MOVES THROUGH THE AREA. MEDIUM RANGE GUIDANCE HAS COME INTO BETTER AGREEMENT WITH THEIR HANDLING OF THINGS DURING THE LATER PORTIONS OF THE FORECAST...SATURDAY THROUGH TUESDAY. IN ADDITION...THE ENSEMBLE GUIDANCE FROM THE GFS AND CANADIAN ARE SIMILAR TO THEIR DETERMINISTIC COUNTERPARTS...AND SHOW A FAIRLY LIMITED AMOUNT OF SPREAD THROUGH THE PERIOD...SUGGESTING THAT A BLEND OF THE OPERATIONAL RUNS IS PROBABLY THE MOST SENSIBLE THING TO DO AT THIS POINT. A FAIRLY POTENT UPPER LOW/SHORT WAVE WILL PASS JUST NORTH OF THE REGION FRIDAY NIGHT THROUGH SATURDAY...HELPING TO DRAG A COLD FRONT ACROSS OUR AREA SATURDAY MORNING. THE 00Z GFS IS A BIT FARTHER SOUTH WITH THIS FEATURE IN COMPARISON TO THE ECMWF AND UKMET...WITH THE CANADIAN OFFERING A COMPROMISE. REGARDLESS OF THE SPECIFICS...THE GENERAL TIMING OF THE FRONT IS VERY SIMILAR AMONGST THE MODELS...WITH CHANCES FOR SHRA/TSRA FRIDAY NIGHT THROUGH SATURDAY MORNING...ENDING WEST TO EAST THROUGH THE REMAINDER OF THE DAY. IF THE UPPER LOW IS FARTHER SOUTH...THERE COULD BE SOME POST FRONTAL SHOWER ACTIVITY LATER IN THE DAY ON SATURDAY...BUT WILL NOT WORRY ABOUT THAT AT THIS POINT. THE GFS...CANADIAN...AND UKMET BRING SHORTWAVE RIDGING INTO THE AREA QUICKLY ON SUNDAY...WHILE THE ECMWF TENDS TO KEEP MORE UPPER LEVEL CYCLONIC FLOW IN THE AREA. HOWEVER...THE ECMWF IS FAIRLY SIMILAR IN BUILDING IN LOW LEVEL RIDGING...AND ALL OF THE AVAILABLE GUIDANCE SHOWS THINGS DRYING OUT CONSIDERABLY. WE SHOULD SEE THINGS COOL OFF AND DRY OUT NICELY SATURDAY NIGHT THROUGH SUNDAY. RIDGING PERSISTS OVER THE AREA THROUGH MONDAY...WITH RETURN FLOW BEGINNING TO SETUP BY MONDAY EVENING. THE GFS MANAGES TO BRING A WEAK SHORTWAVE OUT OF THE CENTRAL PLAINS AND THROUGH OUR AREA LATE MONDAY NIGHT AND TUESDAY. THE ECMWF ALSO HINTS AT THIS FEATURE...ALTHOUGH BOTH SOLUTIONS SHEAR IT OUT QUITE A BIT AS IT HEADS EAST...AND NEITHER WOULD SUGGEST MUCH IN THE WAY OF MOISTURE PRESENT IN ADVANCE OF IT. AT THIS POINT...WITH THE MAIN UPPER TROUGH STILL WELL TO THE WEST...AND THE LOW LEVEL JET LIKELY STILL OVER THE PLAINS...WILL NOT MENTION ANY PCPN WITH THIS FEATURE AND KEEP THINGS DRY THROUGH TUESDAY. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ TRH mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 235 PM EDT TUE AUG 16 2005 .SHORT TERM (TONIGHT THROUGH FRIDAY)... THROUGH TONIGHT: AS EXPECTED... NUMEROUS STORMS HAVE DEVELOPED ON THE HIGHER TERRAIN THIS AFTERNOON WITH MORE SCATTERED ACTIVITY IN THE COASTAL PLAIN AND SANDHILLS ALONG THE WEAK SURFACE MOISTURE CONVERGENCE AXIS & INSTABILITY GRADIENT. THE MOUNTAIN STORMS WILL DROP INTO THE NORTHWEST PIEDMONT OVER THE NEXT FEW HOURS NECESSITATING LIKELY POPS THERE THROUGH EARLY EVENING. DAMAGING WIND GUSTS ARE POSSIBLE AS THE INITIALLY VERY WEAK WIND PROFILE IMPROVES SOMEWHAT... AND STEEP LOW LEVEL LAPSE RATES ALONG WITH POTENTIAL LOW LEVEL DRYING FROM THE INCREASING WSW WINDS COULD EXACERBATE DOWNDRAFTS. THEN WITH THE MESOSCALE VORTICITY CENTER NOW CROSSING KY ALONG THE SYNOPTIC FRONT EXPECTED TO TRACK ALONG THE NC/VA BORDER TONIGHT ACCOMPANIED BY UPPER DIVERGENCE NOTED ON THE 345K SURFACE... WILL EXTEND LIKELY POPS ACROSS THE REST OF THE NORTHERN & NORTHEAST CWA OVERNIGHT. LOWS 71-75. WED THROUGH FRI: WILL CARRY LIKELY POPS IN THE EAST THROUGH MIDDAY WED WITH LOWER CHANCES ELSEWHERE... TAPERING OFF IN THE AFTERNOON AS THE FRONT DROPS TO OUR SOUTH & MORE STABLE AIR WORKS INTO THE NORTH WITH INCREASINGLY DIFFLUENT 850 MB FLOW. HIGHS 83-90 WED... BUT CONFIDENCE IS NOT HIGH IN THESE NUMBERS AS THEY WILL DEPEND ON HOW MUCH IF ANY CLEARING TAKES PLACE IN THE AFTERNOON. THE FRONT WILL LIKELY HANG UP ALONG COASTAL NC ACROSS SC THU AS THE WEAK HIGH PRESSURE AREA NOSES IN FROM THE NORTH... & WILL LEAVE JUST LOW CHANCE POPS THU MAINLY ACROSS THE SOUTH WITH VARIABLY CLOUDY SKIES. HIGHS 83-88. FORECAST GROWS MORE UNCERTAIN BY FRI WITH THE GFS HANGING ONTO MUCH MORE SURFACE RIDGING DOWN THE EASTERN SLOPES. TEND TO PREFER THE MILDER NAM SOLUTION WITH THE SURFACE FRONT DISSIPATING AND A STRONGER MID LEVEL WAVE CROSSING THE GREAT LAKES TENDING TO SHOVE THE PARENT HIGH OUT TO SEA... SINCE IT LOOKS LIKE THE GFS'S FEEDBACK CONTAMINATION CAUSES THIS WAVE TO LOSE DEFINITION THUS KEEPING THE PARENT HIGH IN PLACE. WILL HAVE CHANCE POPS AND HIGHS IN THE MID 80S TO NEAR 90. && .LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)... MID LEVEL RIDGING APPEARS TO DOMINATE THE REGION FRI NIGHT THROUGH SAT. THE ECMWF/GFS MODELS BOTH INDICATE THE FRONT WELL TO OUR SOUTH WITH SURFACE HIGH PRESSURE AREA TRYING TO NOSE IN FROM THE NORTH... HOWEVER SINCE THE GFS APPEARS TO BE OVERZEALOUS WITH ITS COOL NOSE... WILL LEAN MORE TOWARD CLIMATOLOGY FOR MAXES... 86-91. THEN SUN THROUGH MON... THE ANOMALOUS UPPER VORTEX TRACKING ACROSS SOUTHEAST CANADA IS EXPECTED TO BE DEEP ENOUGH (ACCORDING TO THE ECMWF/GFS) TO PUSH A FRONT SOUTHWARD INTO THE REGION... AND A PREFRONTAL TROUGH OVER THE PIEDMONT IS LIKELY TO PRECEDE IT. THEREFORE WILL RESUME POPS SUNDAY AFTERNOON THROUGH MONDAY. TEMPS A BIT ABOVE NORMAL SUNDAY THEN HIGHS SHOULD DROP BACK NEAR OR A LITTLE BELOW NORMAL MONDAY WITH EXPECTATIONS OF COPIOUS CLOUD COVER. TUE FORECAST IS A WILD CARD WITH UNCERTAINTY AS TO HOW FAR SOUTHWARD THE FRONT PUSHES... WITH ONLY A 1020 MB HIGH PUSHING SOUTHWESTWARD BEHIND IT. THE GFS HAS BEEN TRENDING SLIGHTLY NORTH WITH THE FRONT AND ASSOCIATED PRECIP. WITH SYNOPTIC SCALE FRONTAL PASSAGES SO RARE IN NC THIS TIME OF YEAR... WILL HOLD THE FRONT ACROSS NC AND CONTINUE CHANCE POPS TUE... PRIMARILY DURING THE AFTERNOON AND EVENING... AND SLIGHTLY HIGHER ACROSS THE SOUTH & SOUTHEAST WHERE ANY LEE DRYING EFFECTS FROM WESTERLY 850 MB WINDS WILL BE LESSENED. HIGHS TUE 85-89. && .AVIATION... SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE BLUE RIDGE WILL MOVE EAST INTO THE AREA...REACHING THE TRIAD BETWEEN 20 AND 22Z. THE STORMS COULD PRODUCE STRONG WIND GUSTS...AND TAFS WILL MENTION A TEMPO WITH IFR VIS/MVFR CIGS AND WIND GUSTS UP TO 30 KTS. RUC MODEL SHOWS UPPER DIVERGENCE PERSISTING AND A VORTICITY CENTER MOVING EAST ACROSS THE NORTHERN PIEDMONT THROUGH THE EVENING HOURS...SO STORMS WILL LIKELY AFFECT RDU AND RWI BETWEEN 22Z AND 04Z. FAY MAY SEE AN ISOLATED STORM BUT COVERAGE WILL BE GREATEST TO THE NORTH. AREAS THAT RECEIVE RAIN ARE LIKELY TO HAVE IFR FOG OVERNIGHT. WINDS SHIFT TO NORTH-NORTHEAST TOMORROW MORNING AS A SURFACE BOUNDARY MOVES INTO THE AREA. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...DGS nc AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 300 PM MDT TUE AUG 16 2005 .DISCUSSION...CURRENT SURFACE ANALYSIS PLACES LOW PRESSURE CENTERED JUST EAST OF KBIL...WITH BROAD AREA OF HIGH PRESSURE OVER THE MIDWEST. SURFACE BOUNDARY REMAINS DRAPED GENERALLY ALONG THE ND/SD BORDER..WITH SOME CONVECTION FIRING UP NORTH AND EAST OF CWFA. WV IMAGERY CLEARLY SHOWING POTENT SHORT WAVE ENERGY PUSHING THROUGH WYOMING...WHICH WILL ACT AS THE FOCAL POINT FOR CONVECTION THIS EVENING. THE CONCERN WILL BE HOW STRONG THE STORMS WILL GET AND WHERE. RIGHT NOW THINKING THAT THE BEST POTENTIAL FOR SEVERE ACTIVITY WILL BE IN THE NORTHERN PTNS OF CWFA WHERE SFC BOUNDARY/WARM FRONT REMAINS SITUATED. MODELS INDICATING FAIR AMOUNT OF SHEAR...PLENTY TO SUPPORT SUPERCELL DEVELOPMENT OVER NORTHWEST SOUTH DAKOTA. INSTABILITY LOOKING GOOD...WITH MODELS INDICATING 1000+ J/KG...WHICH MAY EVEN BE A CONSERVATIVE ESTIMATE. DECIDED TO GO WITH SEVERE WORDING BEFORE MIDNIGHT ACROSS THE NORTHERN 3 COUNTIES OF CWFA...THOUGH SVR WX IS STILL NOT OUT OF THE QUESTION ACROSS REMAINDER OF NE WYO AND WESTERN SD. THE NEXT CONCERN IS RAINFALL. LATEST RUC AND ETA INDICATING SLOW MOVING STORMS...ESPECIALLY RIGHT MOVERS... WHICH COULD LEAD TO LOCALIZED HEAVY RAINFALL CONCERNS. THIS EVENING UPPER LEVEL LOW BEGINS TO DROP DOWN FROM NORTHERN ALBERTA AND STARTS PUSHING EASTWARD NORTH OF THE INTERNATIONAL BORDER OVER THE NEXT FEW DAYS. GFS REMAINS MUCH MORE AGGRESSIVE WITH THE SPEED OF THE SYSTEM WHICH WILL AFFECT THE FORECAST GOING INTO THE END OF THE WEEK. TOMORROW WILL BRING ANOTHER CHANCE FOR THUNDERSTORMS AS NEXT WAVE COMES SWINGING THROUGH THE CWFA EARLY IN THE AFTERNOON. COLD FRONT IS STILL EXPECTED TO COME PUSHING THROUGH CWFA ON THURSDAY...BRINGING A CONTRAST IN TEMPERATURES FROM NORTH TO SOUTH...ALONG WITH A GENERALLY WET DAY ACROSS CWFA. FRIDAY LOOKING TO BE REASONABLY MILD WITH SOME LINGERING ACTIVITY ACROSS THE AREA. EXTENDED...AFTER UPPER TROF EXITS THE REGION FRIDAY NIGHT...RIDGE OVER THE WEST WILL PUSH INTO THE PLAINS...BRINGING MAINLY DRY AND WARM WEATHER FOR THE WEEKEND. AS RIDGE TRANSLATES EAST OF THE AREA EARLY NEXT WEEK...MAY SEE A RETURN OF THUNDERSTORM CHANCES BY TUESDAY OR WEDNESDAY AS UPPER TROF IS PROGGED TO MOVE ACROSS THE PACIFIC NW. WILL KEEP FORECAST DRY AT THE END OF THE EXTENDED FOR NOW. && .AVIATION...A STRONG UPPER LEVEL DISTURBANCE WILL MOVE ACROSS WY AND EASTERN MT TONIGHT...BRINGING A GOOD CHANCE FOR SHOWERS AND STORMS ACROSS MOST TWEB ROUTES THIS EVENING AND OVERNIGHT...ESPECIALLY TWEB ROUTES 259...260...AND 285. SOME OF THESE STORMS COULD BE SVR WITH LARGE HAIL AND DAMAGING WINDS...ESPECIALLY ACROSS THE BLACK HILLS AND AREAS TO THE NORTH AND WEST. CONDITIONS SHOULD GENERALLY REMAIN VFR THRU TONIGHT AT KGCC AND KRAP. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ sd