AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 353 AM MST SAT NOV 19 2005 .SHORT TERM... (TODAY AND TONIGHT) ...WINDY DAY CONDITIONS ACROSS SERN CO TODAY... CURRENTLY...REGIONAL RADAR DATA IMAGERY WAS SHOWING ISOLD RAIN AND SNOW SHOWERS ACROSS THE PALMER DIVIDE...PIKES PEAK...WET MOUNTAINS...AND SANGRE DE CRISTO MOUNTAINS VERY EARLY THIS MORNING. WEB CAMS SHOWED A DUSTING OF SNOWFALL AROUND MONUMENT...SO DOUBT MUCH OF THE SNOWFALL IS AMOUNTING TO MUCH. ACROSS THE SERN CO PLAINS...ISOLATED RAIN SHOWERS ARE TRYING TO REACH THE GROUND DESPITE RELATIVELY DRY CONDITIONS IN THE SUB-CLOUD REGION. THE COLD FRONT HAS BLASTED SOUTH OF SERN CO. WINDS ACROSS SERN CO HAVE BEEN SUSTAINED 15-25KTS WITH GUSTS UP TO 35KTS...SO FAR. ALL OF THIS WAS IN RESPONSE TO ANOTHER WEATHER SYSTEM MOVING SOUTH THROUGH THE CNTRL US AND CNTRL ROCKIES PER WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES ANIMATION. MID LEVEL TROUGH AXIS WAS CURRENTLY MOVING THROUGH NERN CO AND SUSPECT IT WILL CONTINUE DIGGING ACROSS SERN CO LATER THIS MORNING. IRONICALLY...WITH THE COLD FRONTAL PASSAGE...TEMPS HAVE CLIMBED IN THE 30S AND 40S FROM YESTERDAY EVENINGS TEMPS IN THE 20S AND 30S THANKS TO LOW LEVEL TURBULENT MIXING. TODAY...WILL PLAN ON THE MID/UPPER LEVEL TROUGH TO CONTINUE DRIVING S-SEWD THROUGH ERN CO AND THE CNTRL PLAINS AS THE PARENT ULJ STREAK MOVES OVER ERN CO. MUCH OF THE CLOUDS AND PRECIPITATION ARE RESULTING FROM THE H7-H6 AND H6-H5 FRONTOGENETICAL FORCING... POSITIVE VALUES IMPLYING ASCENT...ACROSS ERN CO. SHOULD SEE CLOUDS ON THE DECREASE FROM NORTH TO SOUTH LATER THIS MORNING AND ESPECIALLY THIS AFTN. WILL MAINTAIN SOME LOW POPS/WX ACROSS OUR SERN CO MOUNTAINS AND ADJACENT PLAINS...BUT MUCH OF THE RAIN SHOWERS ACROSS THE SERN CO PLAINS WILL LIKELY JUST BE LIGHT RAIN AND SPRINKLES. GFS80 IS WAY TOO "WET" WITH THE QPF ALONG THE INTERSTATE 25 CORRIDOR EARLY THIS MORNING. SFC WINDS ACROSS SERN CO WILL BE THE MAIN STORY WITH THIS WEATHER SYSTEM. MODEL SOUNDINGS ACROSS SERN CO CONTINUE TO SUGGEST SUSTAINED SPEEDS OF 15-30KTS WITH POSSIBLE GUSTS TO AROUND 40KTS. AS FOR MAX TEMPS...SINCE THE AIR MASS IN SERN CO ARE ALREADY "MIXED UP"...THEN TEMPS ARE PROBABLY ONLY A CAT OR TWO AWAY FROM THE POTENTIAL HIGH OF AROUND 50F. TONIGHT...THE CNTRL PLAINS SYSTEM PULLS AWAY FROM ERN CO WITH A NEARLY CLEAR SKY AND RELATIVELY LIGHT DRAINAGE SFC WINDS. TEMPS SHOULD BE COLDER THAN THIS MORNING...MAINLY IN LOW LYING VALLEYS AND RIVER VALLEYS. INVERSION SHOULD DEVELOP FROM 6-8K FT MSL ALONG THE ERN SLOPES OF OUR ERN MOUNTAINS DURING THE NGT. METZE .LONG TERM... (SUNDAY THROUGH FRIDAY) MAIN CHALLENGE THROUGH LONG TERM WILL BE TEMPS AND TIMING OF COLD FRONTS THROUGH SE CO... ON SUNDAY...UPPER TROF SHIFTS OFF TO THE SOUTHEAST...WITH NAM HOLDING UPPER LOW FARTHER BACK TO THE SOUTHWEST THAN GFS. THIS CAUSES DIFFERENCES IN THE AMOUNT OF WARM UP FOR SUNDAY...WITH NAM KEEPING H7 TEMPS ABOUT 2 DEGREES COOLER THAN GFS DUE TO SLOWER EASTWARD PROGRESSION OF UPPER LVL FEATURES. FOR NOW NAM APPEARS TO BE THE OUTLIER AND HAVE GONE CLOSER TO THE GFS. DID COOL OFF MAX TEMPS A COUPLE DEGREES...BUT NOT AS MUCH AS THE NAM WOULD SUGGEST. OTHERWISE...SUNDAY WILL BE BREEZY ONCE AGAIN...ESP ACROSS SE PLAINS. NORTHWEST FLOW PATTERN CONTINUES THROUGH THE REMAINDER OF THE EXTENDED...WITH FCST AREA WAVERING ALONG THE EASTERN SIDE OF WESTERN US UPPER RIDGE. NEXT SHORTWAVE TO DROP OUT OF CANADA WILL MOVE INTO THE GREAT LAKES REGION ON MONDAY...WITH NEXT COLD FRONT EXPECTED TO ARRIVE ON MONDAY. NOT MUCH UPPER FORCING OR MOISTURE... SO GOING DRY FCST STILL LOOKS GOOD. MAIN COLD CORE STAYS OFF TO THE NORTHEAST SO MAX TEMPS MAY NOT DIFFER MUCH FROM THE PREVIOUS DAY. TUES APPEARS TO BE THE WARMEST DAY OF THE WEEK...THEN ANOTHER COOL DOWN FOR WED AS THE NEXT SYSTEM MOVES SOUTH OUT OF CANADA. LONG RANGE MODELS (ESP 06Z GFS) DEVELOP A LARGE CLOSED LOW ACROSS THE GREAT LAKES REGION AND UPPER MID WEST THROUGH THE REMAINDER OF THE EXTENDED...WITH NORTHERLY FLOW ACROSS CO SENDING REINFORCING SHOTS OF COLDER AIR INTO THE REGION FOR THURS/FRI. WILL HAVE TO MONITOR THIS POTENTIAL AS THIS COULD MEAN COLDER TEMPS FOR THE HOLIDAY WEEKEND THAN CURRENT GRIDS PORTRAY. BUT WITH UNCERTAINTY ON HOW FAR WEST THESE COLD SURGES WILL PENETRATE...WILL HOLD THE COURSE FOR NOW. -KT && .PUB WATCHES/WARNINGS/ADVISORIES...NONE. && $$ co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 930 AM EST SAT NOV 19 2005 .DISCUSSION... ...RAIN CHANCES INCREASING LATE IN THE WEEKEND THEN COLDER BY TUE... TODAY...AIR MASS GRADUALLY MODIFYING WITH DEW POINTS IN THE 60S IN ALL SECTIONS EXCEPT THE NORTHWEST. WEAK ISENTROPIC LIFT OCCURRING AND PRODUCING A CLOUD DECK GENERALLY 5-6 KFT. COASTAL TROUGH STILL EVIDENT WITH NORTH NORTHEAST FLOW OVER THE PENINSULA AND FLOW SHIFTING TO THE EAST OFFSHORE. FEW CONVERGENCE LINES OFFSHORE PRODUCING SCATTERED SHOWERS WITH MAIN COVERAGE IN SOUTHERN SECTIONS. MOISTENING OF THE LOW LEVELS WILL MAKE FOR A MOSTLY CLOUDY DAY. HIGHEST COVERAGE OF SHOWERS SHOULD BE IN THE SOUTH WHERE THE MOISTURE IS DEEPEST. NORTHERN SECTIONS STILL HAVE SHALLOW MOISTURE SO THINK THAT POPS NEED TO BE LOWERED...ESPECIALLY FOR THE INTERIOR. && .MARINE...GRADIENT LOOKS TIGHTER JUST TO OUR NORTH BUT OVERALL THE GRADIENT LOOKS ENOUGH TO SUPPORT NEAR 20 KNOTS...ESPECIALLY IN THE NORTHERN WATERS. BUOYS HAVE BEEN SHOWING STEADY GUSTS A LITTLE OVER 20 KNOTS. RUC DOES NOT SHOW MUCH CHANGE THROUGH THIS AFTERNOON... THEREFORE PLAN TO GO WITH STRAIGHT ADVISORY FOR THE REST OF THE DAY. GFS SHOWS GRADIENT SLACKENING THIS EVENING SO AN ADVISORY FOR SEAS WILL BE NECESSARY THEN. && .AVIATION...LOOKS MAINLY LIKE VFR CIGS EXCEPT FOR AREAS NEAR THE COAST WHERE SHOWERS PRODUCE MVFR CONDITIONS. && .MLB WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY FLAGLER BEACH TO JUPITER INLET. && $$ LASCODY/SEDLOCK fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 325 PM EST SAT NOV 19 2005 .SHORT TERM... THE COLD FRONT IS CURRENTLY THROUGH WISCONSIN...FAR EASTERN IOWA AND THE NORTHERN PART OF MISSOURI. AS THIS FRONT MAKES ITS WAY EASTWARD IT WILL BE DISSIPATING. THE ENERGY WILL TEND TO STAY UP IN CANADA AND WITH AN UPPER LEVEL LOW TO THE SOUTHWEST OF OUR CWA. AS WHAT REMAINS OF THIS FRONT MOVES INTO THE AREA TONIGHT...JUST BROKEN SKIES ARE EXPECTED. THE RUC40 1000-500MB RELATIVE HUMIDITY HAS HAD THE BEST HANDLE ON THE CLOUD COVER TODAY. AT 3Z IT HAS SOME CLOUDS IN THE AREA BUT NOT MANY AND IT ALSO LESSENS THE AMOUNT OF RH ASSOCIATED WITH THE TROUGH...ANOTHER SIGN THE FRONT IS WEAKENING. DURING THE DAY SUNDAY THE CLOUD COVER WILL HOVER AROUND THE HIGHER END OF THE PARTLY CLOUDY RANGE AND THE LOWER END OF THE BROKEN SKY COVER RANGE...50-75 PERCENT SKY COVERAGE. THAT UPPER LEVEL LOW TO OUR SOUTHWEST WILL NOT MOVE MUCH AT ALL AND HIGH PRESSURE WILL HANG OFF OF THE CENTRAL EAST COAST. SO WINDS TOMORROW WILL BE NOTHING TOO GREAT. TEMPERATURES TONIGHT SHOULD STOP FALLING AT AROUND THE FREEZING MARK. OUR LOW TEMPS FOR TONIGHT IN THE WESTERN PART OF THE CWA MAY BE WARMER THAN WHAT IS IN THE FORECAST IF THOSE CLOUDS TO THE WEST MOVE IN FASTER THAN EXPECTED. 850MB TEMPS TOMORROW AFTERNOON WILL BE AROUND TWO DEGREES CELSIUS SO MADE NOT CHANGES TO TOMORROWS HIGHS. && .LONG TERM... SUNDAY NIGHT THROUGH SATURDAY. WILL BE USING A COMBINATION OF THE 12Z GFS AND 00Z ECMWF FOR THIS EXTENDED FORECAST PACKAGE. FOR SUNDAY NIGHT...UPR LVL CLOSED LOW OVER THE SOUTHEASTERN UNITED STATES WILL DRAW TROPICAL MSTR FROM TROPICAL STORM GAMMA INTO ITSELF. ALSO...A SFC LOW WILL DEVELOP...WHICH SHOULD DEEPEN RAPIDLY ALONG THE EASTERN SEABOARD MONDAY NIGHT INTO TUESDAY. DURING THIS PERIOD...OVERALL NORTHERN HEMISPHERIC PATTERN WILL FEATURE A TRANSITION TO A NEGATIVE NAO PATTERN...WHICH MEANS THE EASTERN UNITED STATES WILL BE UNDER A DEEP H5 TROF THROUGH NEXT WEEKEND. THE TROF WILL BE ENERGIZED BY SVRL S/WVS DIGGING SE INTO THE TROF. THE FIRST ONE WILL ARRIVE MONDAY NIGHT. THIS SYSTEM WILL BRING RAIN/SNOW SHOWERS LIKELY TO THE LAKESHORE REGION WITH A CHANCE OF LIGHT RAIN/SNOW SHOWERS MIXED ELSEWHERE. ONCE COLDER AIR FILTERS INTO THE REGION BY TUESDAY MORNING...ALL PCPN WILL BE IN THE FORM OF SNOW. NORTH NORTHWEST FLOW ACROSS LONG AXIS OF LAKE MICHIGAN WILL FAVOR NORTHWESTERN LAKESHORE COUNTIES FOR POSSIBLE SNOW ACCUMULATIONS. FOR TUESDAY NIGHT INTO WEDNESDAY...A CLIPPER SYSTEM WILL DIVE SOUTHEAST INTO THE GREAT LAKES REGION. WAA IN THE LOW LVLS SHOULD TURN OFF THE LAKE EFFECT SNOW SHOWERS...BUT SYNOPTIC SCALE LIFT FROM WAA WILL BRING AN INCREASING CHC FOR SNOW BY WEDNESDAY MORNING. SNOW WILL MIX WITH RAIN BY LATE WEDNESDAY MORNING DUE TO THE STRONG WAA/WARMER TEMPS ALOFT...BEFORE SWITCHING BACK TO THE FROZEN TYPE BY LATE WEDNESDAY. MUCH COLDER AIR (850 TEMPS NEAR -15 CELSIUS) WILL USHER INTO THE GREAT LAKES FOR THE REMAINDER OF THE EXTENDED. BRINGING A GOOD CHC FOR LAKE EFFECT SNOW SHOWERS...WITH LIGHT SNOW SHOWERS ELSEWHERE. TEMPERATURES WILL BE SOME 10 TO 15 DEGREES BELOW NORMAL THROUGH THE PERIOD. SIGNIFICANT LAKE EFFECT SNOW WILL LIKELY OCCUR...AND THIS IS HIGHLIGHTED IN THE CURRENT HAZARDOUS WEATHER OUTLOOK. && .AVIATION... SUNNY SKIES OUT THERE CURRENTLY AT MID DAY. THE RUC40 1000-500MB RH IS VERY CLOSE TO WHERE THE CLOUDS ARE WITH THE FRONT TO THE WEST...THROUGH WISCONSIN IOWA AND THROUGH CENTRAL OKLAHOMA. RUC40 DOES NOT BRING IN THOSE CLOUDS TIL CLOSE TO MIDNIGHT FOR SBN AND A LITTLE LATER FOR FWA. NOT EXPECTING MUCH MORE THAN LOWER LEVEL BROKEN VFR CEILINGS AT BOTH SBN AND FWA TONIGHT. MODELS ARE BREAKING UP THE FRONT AS IT APPROACHES AND ENTERS INDIANA LATER TONIGHT. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR LMZ043. && $$ SHORT TERM...98 LONG TERM....30 AVIATION...98 in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1239 PM EST SAT NOV 19 2005 .AVIATION... SUNNY SKIES OUT THERE CURRENTLY AT MID DAY. THE RUC40 1000-500MB RH IS VERY CLOSE TO WHERE THE CLOUDS ARE WITH THE FRONT TO THE WEST...THROUGH WISCONSIN IOWA AND THROUGH CENTRAL OKLAHOMA. RUC40 DOES NOT BRING IN THOSE CLOUDS TIL CLOSE TO MIDNIGHT FOR SBN AND A LITTLE LATER FOR FWA. NOT EXPECTING MUCH MORE THAN LOWER LEVEL BROKEN VFR CEILINGS AT BOTH SBN AND FWA TONIGHT. MODELS ARE BREAKING UP THE FRONT AS IT APPROACHES AND ENTERS INDIANA LATER TONIGHT. && .PREV DISCUSSION...(ISSUED AT 637 AM EST) SHORT TERM... TODAY AND TONIGHT A BRIEF RETURN TO BENIGN WEATHER AND WARMER TEMPERATURES WILL BEGIN TODAY AS A FLAT MID LEVEL RIDGE BUILDS OVER THE OHIO VALLEY WHILE THE PATTERN IS IN THE PROCESS OF RELOADING. INCREASING SSW BOUNDARY LAYER FLOW AHEAD OF A COLD FRONT DROPPING THROUGH THE UPPER MIDWEST WILL ADVECT A LOW LEVEL THERMAL RIDGE INTO THE REGION TODAY WITH H85 TEMPS CLIMBING ABOVE ZERO. NGM SURFACE TRAJECTORIES FOR 00Z SUN ORIGINATE FROM CENTRAL MISSOURI WHERE HIGHS WERE IN THE LOW 50S YESTERDAY. THIS WARMER AIR WILL QUICKLY OVERSPREAD THE REGION TODAY WITH WARMING TEMPS ALOFT AND AMPLE MECHANICAL MIXING IN MODERATE SSW GRADIENT. WILL GENERALLY GO BETWEEN MET/MAV GUIDANCE WITH HIGHS INTO THE LOW 50S FOR MUCH OF THE AREA. THE ONLY EXCEPTION WILL BE KAOH AREA WHICH SEEMS TO STRUGGLE TO WARM ON THE FIRST DAY OF A WARMING TREND AND WILL GO UPPER 40S HERE. PATCH OF STRATUS HAS BEEN SLOW TO CLEAR THE NE QUARTER OF THE CWA THIS MORNING BUT EXPECT THIS TO BE GONE BY OR SHORTLY AFTER SUNRISE AS LOW LEVEL WAA CONTINUES TO WEAKEN THE SUBSIDENCE INVERSION WHICH IS RESPONSIBLE FOR TRAPPING THE STRATUS LAYER. OTHERWISE JUST A SLOW INCREASE IN HIGH CLOUD THIS AFTERNOON ACROSS THE NW AS AFOREMENTIONED COLD FRONT OVER THE UPPER MIDWEST APPROACHES. TONIGHT THE COLD FRONT WILL WEAKEN SIGNIFICANTLY AS THE ASSOCIATED MID LEVEL TROUGH SPLITS...WITH ONE WAVE TRANSLATING RAPIDLY ACROSS SOUTHERN CANADA WHILE A MORE SIGNIFICANT PIECE WILL DIG SOUTH INTO THE SOUTHERN PLAINS OVER THE WEEKEND. THE FRONT WILL DO LITTLE MORE THAN BRING AN INCREASE IN CLOUD COVER OVERNIGHT ESPECIALLY TO THE NW ZONES. WILL TREND THE NW TO MOSTLY CLOUDY OVERNIGHT WHILE THE SOUTHEAST COUNTIES WILL STAY MAINLY CLEAR FOR MUCH OF THE NIGHT. WITH A WARMER AND MORE SEASONABLE AIRMASS IN PLACE LOW TEMPS WILL BE NEAR AVERAGE IN THE LOW 30S. LONG TERM... SUNDAY THROUGH FRIDAY. NORTHERN STREAM UL JET SPLIT WITH MOST ENERGY DIVING SOUTH ALONG FRONTRANGE. GFS GETS NOD FOR BETTER/FASTER TIMING WITH THIS FEATURE OVER NAM. FRONTALYTIC JET STREAK ON CLIPPER APPROACHING FOR SUNDAY TOTALLY WASHES FRONT OUT WITH CURRENT TEMP/DRY FORECAST GOOD. MAIN FORECAST CONCERN IS WITH POTENTIALLY PROLONGED AND SIGNIFICANT HOLIDAY LAKE EFFECT SNOW AND NOW MODEL DIFFERENCES A LITTLE DISCONCERTING. NAM APPEARS TOO SLOW WITH CUTOFF THROUGH SOUTHERN STATES...WHICH THOUGH IS GENERALLY A BETTER SOLUTION FOR CUTOFFS. HOWEVER...GIVEN APPARANT INITIAL SPEED OF DIGGING ENERGY NOW INTO NE CO/SE WY...THIS WAVE SHOULD BE ABLE TO RIDE OUT ON HEALS OF TX WAVE EJECTING EWD. AND GIVEN HIGHLY AMPLIFIED PATTERN WITH NEXT UPSTREAM ENERGY INTO GULFAK/150W PATTERN SHOULD REMAIN LARGELY PROGRESSIVE...FAVORING FASTER/CONSISTENT NOGAPS/ECMWF AND TO AN EXTENT GFS/GEM. NAM ALSO APPEARS TOO SLOW WITH GAMMAS NORTHEAST EXODUS...SUBSEQUENTLY NAM ABOUT 12-18 HOURS SLOWER WITH SOUTHEAST US CYCLOGENESIS. GFS DOES BEGIN TO SUFFER WITH HANDLING OF CYCLOGENESIS BEYOND F60 WITH TRACK TOO FAR WEST. OPERATIONAL GEM FURTHEST EAST AND WEAK...THOUGH ITS ENSEMBLE MEMBERS AT F72 AND 96 LEND SUPPORT TO ECMWF. STRONG EAST COAST BOMB TO DRAG MUCH COLDER AIR OVER GRTLKS STARTING LATE MONDAY NIGHT/TUESDAY. CURRENT FORECAST WITH LIKELY POPS IN LES REGION TUE/TUE NIGHT ON TRACK AS IS COLDER THAN MEX TEMPS DY4-7...CLOSER TO ENSEMBLE LOWS GIVEN SIGNIFICANT HIGH AMPLITUDE EASTERN TROF. DELTA-T INCREASE TO AT LEAST UPPER TEENS TUE AND IN CLOUD WINDS INTIIALLY 340/45-50KT TO BACK/SLOW TO ABOUT 320/30 BY TUE EVE CONDUCIVE FOR MULTI/MIGRATORY BANDS TO SETUP. NEXT REINFORCING SHOT OF COLD AIR INTO GRTLKS THU WITH HEIGHTENED SIGNIFICANT PURE LES POTENTIAL WITH GREAT THERMAL CONTRAST/DEEP MOISTURE/DENDRITIC ENHANCEMENT/HIGH EQL. WILL BUMP POPS TO LIKELY IN LES REGION DY6-7 AND CONTINUE TO HIGHLIGHT POTENTIAL IN HWO. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR LMZ043. && $$ SHORT TERM...44 LONG TERM....15 AVIATION...98 in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 901 PM CST SAT NOV 19 2005 .UPDATE... THE MAIN CONCERN TONIGHT WILL BE THE POTENTIAL FOR ANY LIGHT SHOWERS WITH AND HOW COOL TEMPERATURES WILL GET. LATEST WATER VAPOR LOOP SHOWING AN ELONGATED DEFORMATION ZONE/COLD POCKET EXTENDING FROM NORTHEAST KANSAS TO SOUTHERN IOWA. THIS FEATURE IS EXPECTED TO CONTINUE TO SLIDE SOUTHEAST DURING THE COURSE OF THE NIGHT. RADAR LOOP SHOWS SOME RAINFALL TAKING PLACE IN THIS DEFORMATION ZONE AROUND MANHATTAN AND JUNCTION CITY. 00Z SOUNDING AT TOPEKA SHOWS A FAIRLY SATURATED AIR MASS UP TO -12 DEG C, WHICH IS CLOSE TO THE ICE CRYSTAL FORMATION LAYER. HOWEVER, THE AIR IS STILL ABOVE FREEZING UP TO 4500FT WHICH IS ALLOWING FOR MELTING OF ANY ICE CRYSTALS BEFORE REACHING THE GROUND. THEREFORE, I WOULD ANTICIPATE MOSTLY RAIN SHOWERS THIS EVENING. LATER TONIGHT, 00Z NAM CONTINUES TO SHOW THE LOW LEVEL COLD AIR DIVING INTO THE AREA. IT LOOKS LIKE THIS MODEL MAY BE STILL OVERDOING THIS PUSH OF COLDER AIR ACCORDING TO THE LATEST SURFACE OBS. IN ADDITION, THE RUC IS SHOWING THE COLDER AIR MOVING INTO THE AREA TOWARDS DAYBREAK. AS A RESULT, WE HAVE BUMPED UP TEMPERATURES TONIGHT TO REFLECT THIS TREND. WE WILL ALSO BE MAINLY MENTIONING RAIN SINCE THE COLD AIR ADVECTION WILL BE LACKING, AND MOST OF THE PRECIPITATION WILL BE MOVING OUT THIS EVENING. .AVIATION... CEILINGS MAY ALSO END UP STAYING ABOVE 3KFT THROUGH MUCH OF THE NIGHT DUE TO LACK OF COLD AIR ADVECTION UNTIL TOWARDS DAYBREAK. SOME CEILINGS COULD DROP BELOW 2KFT AFTER 10Z. FOR NOW, WE WILL CONTINUE TO SHOW THAT TREND IN THE TAFS MAINLY IN CENTRAL AND SOUTH CENTRAL KANSAS. COX && .PREV DISCUSSION... /ISSUED 229 PM CST SAT NOV 19 2005/ DISCUSSION... TONIGHT: TOUGH FORECAST. NORTH AMERICAN MODEL SEEMED TO INITIALIZED UPPER FEATURES A BIT BETTER THAN GLOBAL FORECAST SYSTEM MODEL, HOWEVER BY 1800 UTC WAS SERIOUSLY STRUGGLING WITH BOUNDARY LAYER/SURFACE TEMPERATURES UPSTREAM. IT HAS OVERDONE THE LOW LEVEL COOL AIR...WHICH MAKES ITS MODEL OUTPUT STATISTICS PROBABILITY OF PRECIPITATION/TEMPERATURES SUSPECT. PRECIPITATION TYPE ALSO PROBLEMATIC. BOTH NORTH AMERICAN MODEL/GLOBAL FORECAST SYSTEM MODEL FORECAST SOUNDINGS SHOW EITHER A LACK OF ICE CRYSTALS OR WARM NEAR SURFACE TEMPERATURES OR BOTH. -RAIN/SPRINKLES OR MAYBE FZDZ SEEM TO BE THE MORE LIKELY COMBOS. HOWEVER WITH DYNAMIC COOLING IN THE VICINITY OF UPPER LOW, MIGHT SEE A BIT MORE COOLING. RATHER THAN GET TOO CUTE, CONSENSUS WAS GO WITH -RAIN/FLURRY COMBO LATE TONIGHT. MODEST CHANCE OF PRECIPITATION DEVELOPING, BUT MEASURING ANYTHING MORE THAN A TRACE WOULD APPEAR TO BE TOUGH BASED ON TRENDS. SUN: MAINLY TRACE PRECIPITATION POSSIBLE EAST OF I-35 IN THE MORNING. NIXED PRECIPITATION IN THE AFTERNOON WITH UPPER LOW MOST LIKELY JUST OUT OF THE STATE. CLEARING SHOULD MOVE ACROSS A GOOD PORTION OF THE AREA DURING THE DAY. THIS SHOULD ALLOW A BIT OF RECOVERY IN THE FAR WEST, WHILE TEMPERATURES STRUGGLE IN THE 40S IN THE EAST. MON: MOSTLY CLEAR/SUNNY CONDITIONS EXPECTED WITH SUBSIDENCE IN WAKE OF LOW/TROUGH. COMBO OF SUNSHINE AND DECENT DOWNSLOPE FLOW SHOULD ALLOW NICE REBOUND IN TEMPERATURES, ESPECIALLY IN THE FAR WEST. TUE-SAT: ONLY MODEST CHANGES FROM YESTERDAY FORECAST FOR THIS PERIOD. OVERALL PATTERN REMAINS THE SAME, WITH ENSEMBLES SHOWING VARIOUS SHADES OF SIMILAR SOLUTIONS. UNFORTUNATELY WITH TIGHT THERMAL GRADIENT...THESE NUANCES RESULT IN SUBSTANTIAL IMPACTS TO TEMPERATURES. ONCE AGAIN HAVE LEANED TOWARD THE ENSEMBLE MODEL OUTPUT STATISTICS MEAN VALUES. THIS SHOULD MINIMIZE OVERALL ERROR AND RUN TO RUN CHANGES. MAIN DIFFERENCE FROM YESTERDAY WAS TO COOL TEMPERATURES ON FRI WITH SLOWER/DEEPER LONGWAVE TROUGH. BIGGEST FEAR IS THAT LOW-MIDDLE LEVEL THERMAL GRADIENT ACROSS AREA LATE IN THE WEEK WILL BE OVERRUN BY WARMER AIR AND RESULT IN SUBSTANTIAL CLOUDS AND POTENTIALLY PRECIPITATION. AT THIS POINT, THAT APPEARS TO BE MOST LIKELY EAST OF THE FORECAST AREA. HOWERTON && PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 34 45 32 57 / 20 10 0 0 HUTCHINSON 32 46 31 58 / 20 10 0 0 NEWTON 33 46 31 56 / 20 10 0 0 ELDORADO 34 43 32 56 / 20 20 0 0 WINFIELD-KWLD 35 46 34 59 / 20 20 0 0 RUSSELL 29 49 29 59 / 20 5 0 0 GREAT BEND 29 47 30 60 / 20 5 0 0 SALINA 32 46 30 57 / 20 10 0 0 MCPHERSON 32 46 30 57 / 20 10 0 0 COFFEYVILLE 36 44 32 56 / 20 20 5 0 CHANUTE 34 43 30 55 / 20 20 5 0 IOLA 34 43 29 55 / 30 20 5 0 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1155 AM EST SAT NOV 19 2005 .UPDATE... MAIN FCST CONCERNS THIS AFTERNOON ARE LIGHT PCPN TRENDS ALONG WITH TEMPS. WV IMAGERY...12Z RAOBS AND RUC ANALYSIS INDICATED A MID LVL TROF FROM N CNTRL ONTARIO THROUGH W LK SUPERIOR TOWARD THE CNTRL PLAINS. AT THE SFC(15Z)...1005 MB LOW PRES WAS LOCATED OVER N LK SUPERIOR WITH A TROF TO THE SW THROUGH W UPR MI INTO CNTRL WI WHILE A COLD FRONT EXTENDED W THROUGH NRN MN. AREA OF LIGHT PCPN...A MIX OF -DZ/-RA OR -SN...ACRS E LK SUPERIOR AND CNTRL UPR MI WAS SUPPORTED BY 295K ISENTROPIC ASCENT AHEAD OF THE TROF. VIS LOOP AND SFC OBS INDICATED EXTENSIVE LOW CLOUDS UPSTREAM BEHIND THE TROF AND FRONT. TEMPS HAVE ALREADY CLIMBED TO THE LOWER 40S DOWNWIND FROM LK MI WHERE SNOW COVER WAS SPARSE AND INTO THE LOWER TO MID 30S OVER THE REST OF THE CWA. PER RADAR/SATELLITE TRENDS AND 12Z RUC/NAM...MAIN AREA OF LGT PCPN WILL CONTINUE TO SLIDE E THIS AFTERNOON LEAVING CLOUDY SKIES. EVEN THOUGH RADAR SHOWS LACK OF RETURNS UPSTREAM...A MENTION OF -DZ/-FZDZ/-SN WAS LEFT IN GIVEN DECENT AMOUNT OF LOW LVL MOISTURE DEPICTED ON TAMDAR AND UPSTREAM RAOBS AND OBS FROM NW OF LK SUPERIOR. OTHERWISE...BOOSTED MAX TEMPS IN LINE WITH OBS WITH SIGNFICANT CAA NOT EXPECTED INTO THE W TIL LATER IN THE AFTERNOON. && .PREV DISCUSSION...ISSUED 425 AM EST SAT NOV 19 2005 FOR TODAY AS WEAKENING SHORTWAVE MOVES THROUGH THE AREA...LACK OF SIGNIFICANT FORCING WILL KEEP PRECIPITATION LIGHT...MAINLY DZ/FZDZ OR -SN. UPSTREAM RADAR TRENDS AND SURFACE OBS FROM PRECIP FIELD SUPPORT THIS LIGHT PRECIP SCENARIO...AS DOES CURRENT OBS FROM AROUND THE CWA. WEAK COLD FRONT/COLD AIR ADVECTION MOVING IN THIS EVENING WILL CAUSE A GRADUAL CHANGEOVER TO MAINLY SCATTERED LIGHT SNOW SHOWERS WITH LITTLE ACCUMULATION. FOR SUN...ALTHOUGH MODELS AGREE WITH STRONG WARM AIR ADVECTION AND HAVE TRENDED WARMER WITH THE 850MB TEMPS...NAM SHOWING +7C REACHING THE WESTERN CWA WITH GFS ONLY 1 DEGREE COOLER...SOME CONCERN WHETHER MECHANICAL MIXING CAN COUNTERACT THE COLDER/MORE DENSE AIR AT THE SURFACE. ALSO...IF LOW STRATUS DEVELOPS AS HINTED AT BY FCST SOUNDINGS...THE LOW SUN ANGLE MIGHT NOT BE ENOUGH TO BURN OFF UNTIL LATE IN THE AFTERNOON. BANKING ON THIS SCENARIO...AM EXPECTING SOME PARTIAL SUNSHINE...ESPECIALLY FOR THE INLAND AREAS...AND A LATE AFTERNOON WARMING INTO THE LOWER 40S FOR MOST AREAS. ATTENTION THEN TURNS TO INITIAL COLD FRONT WITH SHORTWAVE MOVING THROUGH THE UPPER GREAT LAKES ON MON AFTERNOON. TEMPS ARE STILL WARM ENOUGH FOR MIXED PRECIP...BUT BY LATE AFTERNOON A CHANGEOVER TO SNOW SHOWERS IS EXPECTED AS COLD AIR ADVECTION NOSES IN. BIGGER CONCERN IS SECOND SHOT OF COLD AIR RIGHT BEHIND IT ARRIVING MON EVENING. NAM/GFS SHOW 850MB TEMPS FALLING INTO THE TEENS...WITH GOOD CYCLONIC FLOW ACROSS THE UPPER GREAT LAKES FROM DEEP LOW PRESSURE TRACKING RUNNING UP THE EASTERN SEABOARD AS PROGGED BY ALL MODELS. THIS SHOULD CREATE A SIGNIFICANT LAKE EFFECT SNOW SHOWER SETUP FOR THE NORTH HALF OF THE CWA...ESPECIALLY THE NORTH CENTRAL PORTIONS OF THE CWA WHERE NORTHEAST FLOW AND TERRAIN INFLUENCES WILL ENHANCE SNOWFALL AMOUNTS. GFS FCST SOUNDINGS FOR 00Z TUE SHOW AN UNSTABLE TEMPERATURE PROFILE WITH DEEP AVAILABLE MOISTURE AND UNIDIRECTIONAL FLOW THROUGH 600MB. QUICK BUILDING RIDGE MOVING IN BY EARLY TUE WILL HELP TO DIMINISH SIGNIFICANT SNOWFALL AMOUNTS...BUT THE SETUP STILL LOOKS LIKE A POTENTIAL HEADLINE SCENARIO. THE QUICK BUILDING RIDGE WILL ALSO QUICKLY EXIT THE UPPER GREAT LAKES REGION...AS STRONG CLIPPER SYSTEM ARRIVES BY 12Z WED. MODELS SHOW SOME DIFFERENCES IN EXACT TRACK...BUT AS IT SLIDES SOUTHEAST OF THE REGION ANOTHER DECENT LAKE EFFECT SNOW SETUP DEVELOPS. NO CHANGES MADE TO THIS PORTION OF THE FCST...AND ASIDE FROM A FEW TEMPERATURE ISSUES IN THE FIRST FEW PERIODS EXPECT BELOW NORMAL TEMPERATURES THROUGH THE THANKSGIVING HOLIDAY WEEKEND. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB(UPDATE) LAROSA(PREV DISCUSSION) mi AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE ALBANY NY 947 PM EST SAT NOV 19 2005 .SHORT TERM (REST OF TONIGHT)... THIS UPDATE IS FOR CLOUD COVERAGE AND MIN TEMPS. SURFACE HIGH PRESSURE HAS DRIFTED OFF THE SRN NEW ENGLAND COAST. THE 500 MB FLOW ASSOCIATED WITH MID-LEVEL RIDGE OVER THE WRN ATLANTIC HAS FLATTENED A BIT WITH A SHORT WAVE IN THE W/SW FLOW MOVING ACROSS W-CNTRL PA AND WRN NY. THIS SHORTWAVE HAS GENERATED SOME SCT-BKN CIRRUS CLOUDS OVER UPSTATE NY. THESE CLOUDS ARE MAKING THERE WAY INTO THE GREATER CAPITAL REGION...LOWER CATSKILLS AND MID HUDSON VALLEY AT THIS TIME PER THE IR SAT PICTURE. THE 40KM RUC NICELY HAS THE 500 MB VORT MAX JUST SOUTH OF KELM AT THIS TIME. WE WILL MAKE THE CLOUD COVER PARTLY CLOUDY W AND N OF ALY FOR A BRIEF PERIOD AND THEN TREND TO MOSTLY CLEAR. ALSO...TEMPS IN SOME LOCATIONS HAVE FALLEN TO THE PREV. FORECAST MIN VALUES (I.E. ALB 28F AT 02Z/9 PM). THIS WAS DUE TO IDEAL RADIATIONAL COOLING CONDITIONS EARLY ON...CLEAR SKIES AND CALM WINDS. WE FEEL THIS FALLING OF THE TEMPS WILL STOP IN THE 05Z-07Z TIME FRAME OVER THE CAPITAL REGION...LOWER CATSKILLS... HELDERBERGS... BERKSHIRES AND MID HUDSON VALLEY WITH LIGHT SOUTHERLY WINDS AND THE CIRRUS CLOUDS. HOWEVER...WE WILL LOWER MIN TEMPS A CATEGORY (2-3 DEGREES) MAINLY OVER THE CAPITAL REGION... HELDERBERGS...CNTRL MOHAWK VALLEY AND LOWER CATSKILLS BASED ON THE 02Z OBSERVATIONS. NON-DIURNAL TEMP TRENDS WILL BE DONE IN THE REST OF THE OVERNIGHT PERIOD. UPDATE...WASULA && .PREVIOUS DISCUSSION... (ISSUED AT 315 PM) SHORT TERM (TONIGHT THROUGH TUESDAY)...STORMY AND EVENTUALLY COLDER WEATHER PATTERN SETTING UP ACROSS THE NORTHEAST. AIRMASS ACROSS THE REGION CONTINUES TO MODERATE. MID/HI CLOUDINESS DEPARTED THIS MORNING BUT WIDESPREAD HIGH-BASED STRATOCU SPREAD OVER MOST OF NY N AND W OF KALB BY LATE MORNING. DECK SHIFTED EAST AND AND WAS STEADILY SHRINKING BY MID AFTERNOON. A WEAK COLD FRONT APPROACHES FROM THE WEST LATER TONIGHT AND SUNDAY. SURFACE REFLECTION WEAK BUT H8 THERMAL ANALYSIS INDICATES REMNANTS OF FRONT DROP THROUGH NY SUNDAY WITH H8 TEMPERATURES COOLING TO -1/-3C IN FAR NORTH. THAT MAY BE ENOUGH TO PRODUCE A FEW LAKE INDUCED FLURRIES OR SPITS. WILL CONFINE CHANCE OR SLIGHT CHANCE POPS TO SOUTHERN ADIRONDACKS. MOST MODEL HAVE COME INTO AGREEMENT ON MAJOR EAST COAST CYCLOGENESIS EARLY NEXT WEEK. DIFFERENCES REMAIN WHICH WILL BE IMPORTANT TO EVENTUAL EVOLUTION OF SENSIBLE WEATHER IN CWA. GFS HAS BEEN PRETTY CONSISTENT FOR PAST 36 HOURS WITH A WARM INLAND TRACK. 06Z GFS HAS A 972 MB LOW NEAR KPOU AT 12Z TUE. 00Z NOGAPS ALMOST IDENTICAL WITH LOW POSITION BUT ABOUT 12 HOURS SLOWER THAN WHAT WE SAW YESTERDAY. 00Z/12Z UKMET IN THE BALLPARK ALSO AND A LITTLE SLOWER THAN GFS. INTERESTINGLY GFS WAS THE SLOW MODEL YESTERDAY. 00Z OUTLIER WAS CANADIAN GLOBAL WITH A LESS STRONG LOW FURTHER OFFSHORE AND HENCE COLDER SOLUTION BUT CWA PRECIP LIGHT. CANADIAN MEAN ENSEMBLE FORECAST TRACK IS CLOSE TO CAPE COD. 12Z GUIDANCE...12Z NAM LOOKS DECIDEDLY LIKE THE 00Z CANADIAN WITH A LESS INTENSE LOW...(988 MB)...TRACKING A LITTLE EAST OF CAPE COD. RESULTANT QPF FOR CWA IS LIGHT. WITH VERY LITTLE OVER NW 2/3'S CWA. EVEN WITH EASTERLY TRACK MOST PRECIP (IN SE) IS LIQUID. PARTIAL THICKNESS SUPPORT SOME ELEVATION SNOW NEAR END. 12Z GFS IS SIMILAR TO PREVIOUS RUNS BUT TRACK SLIGHTLY FURTHER EAST...BUT OVERALL SUPPORTS PREVIOUS FORECAST. && LONG TERM (TUESDAY NIGHT THROUGH SATURDAY)... IN WAKE OF EAST COAST STORM...ARCTIC AIR BLOWS INTO THE REGION WITH ACTIVE LAKE EFFECT SETTING UP. LAKE ONTARIO WATER TEMPERATURE DOWN TO 9-10C. H8 TEMPERATURES -10/-11C WHICH SHOULD PROVIDE PLENTY OF INSTABILITY FOR LAKE EFFECT. PERIOD OF LAKE EFFECT WILL BE RELATIVELY SHORT LIVED AS WEATHER SYSTEMS MOVE QUICKLY. WEAK SURFACE RIDGING BUILDS IN BY WEDNESDAY MORNING WITH MIXED LAYER SHRINKING UP. A NEXT SYSTEM APPROACHES FLOW GOES MORE SW BY WEDNESDAY AFTERNOON. UPPER LOW EVENTUALLY TAKES UP RESIDENCE NEAR OR A LITTLE N OF NORTHERN GREAT LAKES. A NUMBER OF IMPULSES ROTATE AROUND IT. TIMING CONSISTENCY NOT REAL GOOD. FIRST SYSTEM AFFECTS REGION WEDNESDAY NIGHT-THURSDAY NIGHT. MORE RECENT SOLUTIONS ARE NOT AS COLD AND FAVOR A MIXED BAD. FRIDAY MAY BE SPENT IN DRY SLOT. COLD AIR WORKING IN BUT FLOW SOUTHWEST...MIXED LAYER NOT LARGE AND WEAK SURFACE RIDGING PRESENT. THAT MAY LIMIT PRECIP. WILL KEEP LOW POP -SHSN N ONLY. && AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY EVENING. SOME LOCALIZED MVFR WILL BE ENCOUNTERED OVER THE HIGHER TERRAIN OF THE ADIRONDACKS THIS AFTERNOON WITH BROKEN TO OVERCAST CLOUDS 4500 TO 6500 FT MSL. THESE CLOUDS WILL THIN AND DIMINISH LATER THIS AFTERNOON. WINDS WILL GENERALLY BE SOUTH TO SOUTHWEST 5 TO 10 KNOTS THIS AFTERNOON...BECOMING NEARLY CALM TONIGHT...THEN LIGHT FROM THE SOUTH SUNDAY. WEATHER IS LIKELY TO DETERIORATE MONDAY AFTERNOON. && .HYDROLOGY... ABOUT 10 THOUSAND CFS IS BEING RELEASED FROM THE GREAT SACANDAGA LAKE TO BRING THE LAKE LEVEL DOWN SO THERE WILL BE SOME STORAGE AVAILABLE TO IMPOUND RUNOFF FROM FUTURE STORMS. IN ADDITION TO THIS...HINCKLEY...DELTA...SCHOHARIE...AND ASHOKAN RESERVOIRS ARE FULL. THIS IS RESULTING IN THE HUDSON BEING ABOUT TWO FEET ABOVE NORMAL AND THE MOHAWK ABOUT A FOOT ABOVE NORMAL. NATURAL STORAGE IN SCHROON LAKE IS KEEPING THE SCHROON RIVER ABOUT TWO FEET ABOVE NORMAL AS WELL. NO SIGNIFICANT PRECIP IS EXPECTED UNTIL MONDAY NIGHT...BUT THE INTENSITY AND TRACK THAT SEVERAL MODELS MAKE OF THE NEXT STORM WOULD BRING ONE TO TWO INCHES OF RAIN OVER THE REGION MONDAY NIGHT INTO MIDDAY TUESDAY. THIS WOULD LIKELY RESULT IN SOME FLOODING IN PLACES LIKE THE STILLWATER FLATS AND ALONG THE MOHAWK WEST OF FONDA. A RIVER STATEMENT WAS ISSUED EARLY THIS AFTERNOON. WE WILL RE-EXAMINE THINGS SUNDAY AND THEN GO WITH AN ESF IF THE MODELS CONTINUE TO PROJECT HEAVY RAIN OVER THE AREA. A CHANGE IN TRACK COULD MAKE A BIG DIFFERENCE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NY...NONE. VT...NONE. && $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 943 PM EST SAT NOV 19 2005 .SHORT TERM (TONIGHT)...SKIES CONTINUE TO CLOUD OVER AS WINDS ON THE KLTX VAD WIND PROFILE ARE SHOWING SOUTHEAST TO SOUTH WINDS JUST ABOVE THE SURFACE. ISENTROPIC LIFT IS SEEN ON THE 00 UTC RUC 290 KELVIN SURFACE. THIS INCREASE IN MOISTURE IS SEEN WITH THE 3000 FT CEILING AT FLORENCE. WILL UPDATE CURRENT FORECAST FOR SKY COVER OTHERWISE REST OF THE FORECAST LOOKS FINE. && .AVIATION...MOISTURE CONTINUES TO INCREASE ACROSS THE AREA...ESPECIALLY SOUTHERN AREAS VIA SATELLITE IMAGERY AND REGIONAL RADAR LOOPS. HAVE INCREASED THE TIMING OF LOWER CEILINGS SLIGHTLY FROM PREVIOUS PACKAGE WHILE USING THE SAME SPATIAL RESOLUTION. ADDED MVFR CIGS AND VISIBILITIES TO MYR AND CRE FOR SUNDAY PM PER MAV POPS. && .MARINE...SURFACE HIGH REMAINS NORTH OF THE REGION WITH SURFACE ANALYSIS SHOWING A WEAK TROF OFF THE SOUTHEAST COAST. NORTHEAST WINDS WILL SHIFT TO EAST AS HIGH MOVES FURTHER EAST AND COASTAL TROF MOVES CLOSER TO THE COAST. TROF REMAINS OFFSHORE BUT MAY MOVE OVER THE NEAR SHORE WATERS LATE SUNDAY...SHIFTING WINDS TO A SOUTHEASTERLY DIRECTION. ONLY CHANGES FOR EVENING UPDATE WILL BE SLIGHT TWEAKS TO WINDS/SEAS BUT NO MAJOR CHANGES PLANNED. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...NONE. SC...NONE. MARINE...NONE. && $$ SHORT TERM...HAWKINS AVIATION...SHK MARINE...III nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 300 PM CST SAT NOV 19 2005 .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT... MAIN FORECAST PROBLEM IN THE SHORT TERM WILL BE CLOUDS/FOG TONIGHT THEN TEMPERATURES THEREAFTER. QUIET PERIOD EXPECTED WITH NO PRECIP ANTICIPATED IN THE SHORT TERM. GFS/NAM APPEAR SIMILAR THROUGH THE SHORT TERM...WILL UTILIZE A BLEND FOR DETAILS. CURRENTLY..SATELLITE INDICATES CLOUD SHIELD ERODING SLOWLY FROM WEST TO EAST WITH FAR WESTERN COUNTIES IN THE SUN. FIRST THOUGHT IS WHEN WILL THESE CLOUDS CLEAR. LATEST RUC AND NAM MODEL RUNS INDICATE 925 MB RH DRYING OUT. NEXT THOUGHT IS IF FOG WILL DEVELOP. BUFKIT SOUNDINGS INDICATE THAT IF GRADIENT DROPS OFF TONIGHT...THERE IS A POSSIBILITY. THEREFORE WILL CONTINUE A GRADUAL WEST TO EAST CLEARING AS INDICATED BY RUC AND NAM AND MENTION PATCHY FOG PER BUFKIT ANALYSIS...EXCEPT FOR THE SOUTHWEST...AFTER MIDNIGHT. A SHORTWAVE CONTINUES TO SUPPRESS THE PACIFIC UPPER RIDGE ON SUNDAY. TEMPERATURES ON SUNDAY WILL STILL BE ABOVE NORMAL BUT WITH A GOOD GRADIENT FROM CLOSER TO SEASONAL TEMPERATURES NORTHEAST TO WELL ABOVE NORMAL TEMPERATURES SOUTHWEST. UPPER RIDGE BUILDS BACK EAST MONDAY AND TUESDAY BEFORE GETTING SUPPRESSED AGAIN TUESDAY NIGHT...THIS TIME FROM AN IMPULSE RIDING OVER WESTERN CANADIAN RIDGE THAT PHASES WITH THE HUDSON BAY LOW AND PULLS SOME COLDER AIR SOUTH. OVERALL VERY FEW CHANGES IN THE SHORT TERM PERIOD. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT... MAIN LONGWAVE PATTERN CONTINUES WITH RIDGE OVER THE WEST COAST AND A TROUGH OVER EASTERN NORTH AMERICA. THIS KEEPS NORTH DAKOTA IN A PATTERN WITH NORTHWEST FLOW ALOFT. THIS MEANS A SERIES OF SURFACE LOWS MOVING OUT OF CENTRAL CANADA DIVING TOWARDS THE WESTERN GREAT LAKES ACCOMPANIED BY COLD FRONTS MOVING THROUGH NORTH DAKOTA...WITH SHORT PERIODS OF WARMER PACIFIC AIR PUSHING INTO WESTERN NORTH DAKOTA. THIS TRANSLATES TO HIGH TEMPERATURES IN THE 20S AND 30S FOR EASTERN PARTS OF THE STATE...AND HIGHS IN THE 30S AND 40S FOR THE WEST. KEPT A SLIGHT CHANCE OF PRECIPITATION FOR WEDNESDAY AND THURSDAY WITH UPPER LEVEL ENERGY MOVING THROUGH THE NORTHWEST FLOW. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ TWH/JV nd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 931 AM CST SAT NOV 19 2005 .UPDATE... COLD FRONT QUICKLY PUSHING SWD THRU THE NWRN CWFA WITH STRONG ISALLOBARIC HIGH OF 5MB/3HR ACRS SE NM. PRESSURE GRADIENT FROM 12Z RUC FAVORS WINDS WELL INTO THE BREEZY CATEGORY. CONSIDERING ISALLOBARIC CONTRIBUTIONS HAVE OPTED TO INCREASE WINDS ESPECIALLY N AND HAVE ADDED WIND GUSTS TO 35 MPH. ADDITIONAL UPDATES WILL BE POSSIBLE LATE MORNING TO INCLUDE HIER WINDS FARTHER S. ALSO THICK DECK OF MID CLOUDS HAVE DEVELOPED ACRS PANHANDLE/ERN NM AND HAVE REFLECTED INCREASED CLOUDS IN GRIDS...PROBABLY PERIODS OF MOSTLY CLOUDY CONDITIONS ACRS THE NW-N LATER TODAY. CLOUDS TO IMPACT TEMPS AND HAVE DECREASED TODAY/S HIGHS A COUPLE OF DEGREES. UPDATED PRODUCTS SENT. && .PREV DISCUSSION... (ISSUED 257 AM CST SAT NOV 19 2005) SHORT TERM... A POSITIVELY TILTED SHORTWAVE TROUGH IS EXITING THE REGION AT THIS TIME. ANOTHER STRONGER TROUGH IS DEVELOPING OVER THE NORTHERN HIGH PLAINS. AT THE SURFACE...A COLD FRONT EXTENDED FROM THE COLORADO ROCKIES NORTHEAST INTO A SURFACE LOW OVER SOUTHWESTERN ONTARIO. MODEST ISENTROPIC UPGLIDE IS NOTED OVER SOUTHEASTERN ZONES WHERE BROKEN TO OVERCAST MVFR CEILINGS PERSIST. THIS MOISTURE IS FORECAST TO ADVECT EAST THIS MORNING AS THE LOW LEVEL FLOW ACQUIRES MORE OF A WESTERLY COMPONENT. SURFACE ANTICYCLOGENESIS IN RESPONSE TO THE SECONDARY SHORTWAVE TROUGH IS EVIDENT VIA PRESSURE RISES ON THE ORDER OF 1MB/HR CENTERED OVER NORTHEASTERN COLORADO. THIS ANTICYCLOGENESIS IS FORECAST TO CONTINUE TODAY AS THE ASSOCIATED SHORTWAVE TROUGH TRANSLATES SOUTHEAST AND AMPLIFIES...AND AS IT DOES SO...THE SURFACE COLD FRONT WILL CONTINUE TO EVOLVE SOUTH...REACHING OUR NORTHWESTERN ZONES AROUND 19/15Z OR SO...EVENTUALLY REACHING THE RIO BRAVO DEL NORTE SOMETIME LATE THIS AFTERNOON. THE POTENTIAL IS THERE FOR GAP WINDS TO DEVELOP THROUGH GUADALUPE PASS THIS AFTERNOON...BUT THE PRESSURE GRADIENT LOOKS WEAK ENOUGH THAT HIGH WIND WARNING CRITERIA WILL NOT BE MET. THE AIRMASS BEHIND THIS FEATURE ISN'T PARTICULARLY COLD...AND AS THE ATMOSPHERE IS FORECAST TO REMAIN QUITE DRY...NO SIGNIFICANT WEATHER IS EXPECTED WITH THIS FRONTAL PASSAGE. THUS ALL WE CAN EXPECT WITH FRONTAL PASSAGE IS A WIND SHIFT TO THE NORTH AND AN INCREASE IN WIND SPEED. WE EXPECT THESE WINDS WILL SUBSIDE AROUND SUNSET AS THE SURFACE PRESSURE GRADIENT RELAXES AND THE PBL DECOUPLES. TONIGHT LOOKS QUIESCENT AS SURFACE RIDGING AND AMPLE DOWNGLIDE ALOFT ARE FORECAST. WE SEE LITTLE DIFFERENCE BETWEEN THE NAM AND GFS MODELS REGARDING THE TIMING OF FRONTAL PASSAGE. HOWEVER...NOT SURPRISINGLY THE NAM DOES SEEM TO CAPTURE THE INCREASE IN WINDS BEHIND THE FRONT BETTER THAN THE GFS. CONSEQUENTLY THE WIND GRIDS ARE WEIGHTED TOWARD THE NAM SOLUTION. LIKEWISE...THERE IS LITTLE DIFFERENCE SEEN BETWEEN THE NAM AND GFS MODELS REGARDING TEMPERATURE AND DEWPOINT GRIDS... AND THESE GRIDS REFLECT A COMPROMISE BETWEEN THESE TWO SOLUTIONS. SKY GRIDS TRACK THE GFS 285K-295K MOISTURE PROGS IN CLOSE...THEN TRENDING TOWARD THE SIGNIFICANT LAYER RH PROGS FOR THIS AFTERNOON AND TONIGHT. LASTLY...POP...QPF...AND SENSIBLE WEATHER GRIDS REFLECT SIG WX NIL. LONG TERM... PATTERN OF BLOCKING UPPER RIDGE ACROSS THE WESTERN STATES WITH A COUPLE OF STRONG UPPER TROUGHS/LOWS DEVELOPING AND TRANSLATING ACROSS THE CENTRAL AND EASTERN STATES WILL BE IN PLACE FOR THE NEXT WEEK. THE SOUTHERN STREAM LOW THAT WILL AFFECT THE REGION SUNDAY WILL NOT BE ABLE TO TAP INTO ANY SIGNIFICANT COLD AIR FROM THE NORTHERN STREAM AS IT TRACKS ACROSS THE LOWER MISSISSIPPI AND OHIO VALLEYS MONDAY AND TUESDAY. DURING THIS TIME THE COLD AIR FROM THE NORTHERN STREAM WILL REMAIN WELL NORTH AND EAST OF THE FORECAST AREA. A SECOND STRONG UPPER LOW WILL DEVELOP ACROSS THE GREAT LAKES AND EASTERN STATES WEDNESDAY THROUGH NEXT FRIDAY BUT AGAIN IT APPEARS THE COLD AIR WILL STAY WELL NORTHEAST OF THE REGION. THE SOUTHERN STREAM UPPER LOW CURRENTLY OFF THE WEST COAST WILL MAKE ONLY VERY SLOW PROGRESS EASTWARD THROUGH AT LEAST NEXT THURSDAY AS IT ENCOUNTERS RESISTANCE FROM THE UPPER RIDGE. TEMPERATURES THE NEXT WORK WEEK WILL BE NEAR TO ABOVE NORMAL WITH NO PRECIPITATION. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 99/99 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1237 AM EST SUN NOV 20 2005 .AVIATION... VFR CONDITIONS WILL CONTINUE TO PREVAIL FOR THE 06Z TAF CYCLE. JUST SOME THIN SCT CIRRUS DRIFTING NE OVER THE TERMINALS EARLY THIS MORNING AHEAD OF ADVANCING MID LEVEL TROUGH. SURFACE COLD FRONT WILL WEAKEN RAPIDLY AS IT APPROACHES THE AREA TODAY AS ASSOCIATED MID LEVEL TROUGH SPLITS. NAM BRINGS FROPA THROUGH KSBN AROUND MIDDAY WHILE GFS WASHES FRONT OUT TO THE WEST OF KSBN. THIS HAS SIGNIFICANT IMPLICATIONS ON CIG FORECAST WITH EXPANSIVE STRATUS DECK ON THE COLD SIDE OF THE FRONT. WILL GIVE A NOD TO THE HIGHER LOW LEVEL RESOLUTION OF THE NAM AND BRING A WIND SHIFT AND LOW VFR DECK INTO KSBN THIS AFTERNOON. FRONT WILL NEVER REACH KFWA HOWEVER WITH JUST AN INCREASE IN HIGH AND EVENTUALLY MID LEVEL CLOUD THROUGH THE PERIOD WITH APPROACH OF THE MID LEVEL TROUGH AXIS. && .SHORT TERM... THE COLD FRONT IS CURRENTLY THROUGH WISCONSIN...FAR EASTERN IOWA AND THE NORTHERN PART OF MISSOURI. AS THIS FRONT MAKES ITS WAY EASTWARD IT WILL BE DISSIPATING. THE ENERGY WILL TEND TO STAY UP IN CANADA AND WITH AN UPPER LEVEL LOW TO THE SOUTHWEST OF OUR CWA. AS WHAT REMAINS OF THIS FRONT MOVES INTO THE AREA TONIGHT...JUST BROKEN SKIES ARE EXPECTED. THE RUC40 1000-500MB RELATIVE HUMIDITY HAS HAD THE BEST HANDLE ON THE CLOUD COVER TODAY. AT 3Z IT HAS SOME CLOUDS IN THE AREA BUT NOT MANY AND IT ALSO LESSENS THE AMOUNT OF RH ASSOCIATED WITH THE TROUGH...ANOTHER SIGN THE FRONT IS WEAKENING. DURING THE DAY SUNDAY THE CLOUD COVER WILL HOVER AROUND THE HIGHER END OF THE PARTLY CLOUDY RANGE AND THE LOWER END OF THE BROKEN SKY COVER RANGE...50-75 PERCENT SKY COVERAGE. THAT UPPER LEVEL LOW TO OUR SOUTHWEST WILL NOT MOVE MUCH AT ALL AND HIGH PRESSURE WILL HANG OFF OF THE CENTRAL EAST COAST. SO WINDS TOMORROW WILL BE NOTHING TOO GREAT. TEMPERATURES TONIGHT SHOULD STOP FALLING AT AROUND THE FREEZING MARK. OUR LOW TEMPS FOR TONIGHT IN THE WESTERN PART OF THE CWA MAY BE WARMER THAN WHAT IS IN THE FORECAST IF THOSE CLOUDS TO THE WEST MOVE IN FASTER THAN EXPECTED. 850MB TEMPS TOMORROW AFTERNOON WILL BE AROUND TWO DEGREES CELSIUS SO MADE NOT CHANGES TO TOMORROWS HIGHS. && .LONG TERM... SUNDAY NIGHT THROUGH SATURDAY WILL BE USING A COMBINATION OF THE 12Z GFS AND 00Z ECMWF FOR THIS EXTENDED FORECAST PACKAGE. FOR SUNDAY NIGHT...UPR LVL CLOSED LOW OVER THE SOUTHEASTERN UNITED STATES WILL DRAW TROPICAL MSTR FROM TROPICAL STORM GAMMA INTO ITSELF. ALSO...A SFC LOW WILL DEVELOP...WHICH SHOULD DEEPEN RAPIDLY ALONG THE EASTERN SEABOARD MONDAY NIGHT INTO TUESDAY. DURING THIS PERIOD...OVERALL NORTHERN HEMISPHERIC PATTERN WILL FEATURE A TRANSITION TO A NEGATIVE NAO PATTERN...WHICH MEANS THE EASTERN UNITED STATES WILL BE UNDER A DEEP H5 TROF THROUGH NEXT WEEKEND. THE TROF WILL BE ENERGIZED BY SVRL S/WVS DIGGING SE INTO THE TROF. THE FIRST ONE WILL ARRIVE MONDAY NIGHT. THIS SYSTEM WILL BRING RAIN/SNOW SHOWERS LIKELY TO THE LAKESHORE REGION WITH A CHANCE OF LIGHT RAIN/SNOW SHOWERS MIXED ELSEWHERE. ONCE COLDER AIR FILTERS INTO THE REGION BY TUESDAY MORNING...ALL PCPN WILL BE IN THE FORM OF SNOW. NORTH NORTHWEST FLOW ACROSS LONG AXIS OF LAKE MICHIGAN WILL FAVOR NORTHWESTERN LAKESHORE COUNTIES FOR POSSIBLE SNOW ACCUMULATIONS. FOR TUESDAY NIGHT INTO WEDNESDAY...A CLIPPER SYSTEM WILL DIVE SOUTHEAST INTO THE GREAT LAKES REGION. WAA IN THE LOW LVLS SHOULD TURN OFF THE LAKE EFFECT SNOW SHOWERS...BUT SYNOPTIC SCALE LIFT FROM WAA WILL BRING AN INCREASING CHC FOR SNOW BY WEDNESDAY MORNING. SNOW WILL MIX WITH RAIN BY LATE WEDNESDAY MORNING DUE TO THE STRONG WAA/WARMER TEMPS ALOFT...BEFORE SWITCHING BACK TO THE FROZEN TYPE BY LATE WEDNESDAY. MUCH COLDER AIR (850 TEMPS NEAR -15 CELSIUS) WILL USHER INTO THE GREAT LAKES FOR THE REMAINDER OF THE EXTENDED. BRINGING A GOOD CHC FOR LAKE EFFECT SNOW SHOWERS...WITH LIGHT SNOW SHOWERS ELSEWHERE. TEMPERATURES WILL BE SOME 10 TO 15 DEGREES BELOW NORMAL THROUGH THE PERIOD. SIGNIFICANT LAKE EFFECT SNOW WILL LIKELY OCCUR...AND THIS IS HIGHLIGHTED IN THE CURRENT HAZARDOUS WEATHER OUTLOOK. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ AVIATION...HITCHCOCK SHORT TERM...98 LONG TERM....30 in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 255 AM EST SUN NOV 20 2005 .DISCUSSION... A POTENTIALLY INTERESTING WEEK SHAPING UP ACROSS THE AREA...WITH THE POTENTIAL FOR DECENT LES LATE MONDAY INTO EARLY TUESDAY THEN AGAIN FROM LATE WEDNESDAY INTO FRIDAY. LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES SHOW A BROAD UPPER RIDGE OVER THE WESTERN US WITH A VIGOROUS SHORT WAVE/UPPER LOW DIVING TOWARD THE LOWER MISSISSIPPI VALLEY. THE MAIN THEME FOR THIS WEEK WILL BE THE DEVELOPMENT OF AN HIGHLY AMPLIFIED LONG WAVE TROUGH OVER THE EASTERN US...BRINGING COLD TEMPERATURES INTO THE GREAT LAKES REGION AND SETTING THE STAGE FOR LAKE EFFECT SNOW SHOWERS. THE MOST NOTEWORTHY FEATURE OVER THE NEXT FEW DAYS WILL BE AN INTENSE SURFACE LOW WHICH WILL DEVELOP OVER THE SOUTHEAST US AND MOVE UP THE EAST COAST. THERE IS GENERAL AGREEMENT AMONGST THE VARIOUS MODEL GUIDANCE ON THE DEVELOPMENT OF THIS INTENSE SYSTEM...BUT THERE ARE DIFFERENCES IN TIMING AND INTENSITY...WHICH WILL ACTUALLY HAVE SOME IMPACT ON THE WEATHER IN OUR AREA. THE SPHERE OF INFLUENCE OF THIS FEATURE WILL IMPACT THE DEGREE OF COLD AIR AND CYCLONIC FLOW OVER OUR AREA...WHICH WILL OBVIOUSLY HAVE AN IMPACT ON THE LES POTENTIAL DURING THE FIRST PART OF THE WEEK. WILL FOLLOW A BLEND OF THE NAM AND GFS THROUGH 36 HOURS...THEN TREND TOWARD A BLEND OF THE GFS AND UKMET SOLUTIONS. FEEL THE GFS IS A BIT TOO STRONG WITH THE EAST COAST SYSTEM...POSSIBLY DUE TO SOME CONVECTIVE FEEDBACK ISSUES OFF THE MID ATLANTIC COAST AS DISCUSSED BY HPC. THE UKMET PROVIDES SOMEWHAT OF A COMPROMISE BETWEEN THE NAM AND GFS...AND IS ALSO REASONABLY IN LINE WITH THE CANADIAN HANDLING OF THIS FEATURE. ALL OF THE GUIDANCE IS IN GOOD AGREEMENT WITH THE TIMING OF THE COLD FRONT EXPECTED TO MOVE THROUGH OUR AREA ON MONDAY...WHICH ULTIMATELY SETS THE STAGE FOR LES MONDAY AFTERNOON INTO TUESDAY WITH THE ARRIVAL OF CONDITIONAL INSTABILITY OVER LAKE SUPERIOR. IN THE SHORTER TERM...RADAR IMAGERY CURRENTLY SHOWING SOME LAKE EFFECT PCPN MOVING INTO THE NORTH CENTRAL UP OFF OF LAKE SUPERIOR. ALTHOUGH MODEL SOUNDINGS WOULD SUGGEST THIS SHOULD JUST BE DRIZZLE GIVEN ONLY -5C OR SO TEMPERATURES WITHIN THE MOIST LAYER...LIGHT SNOW SHOWERS HAVE BEEN OBSERVED. A TAMDAR SOUNDING FROM KCMX AROUND 04Z INDICATED TEMPERATURES AS COLD AS -8C IN THE MOIST LAYER...WHICH WOULD BE MARGINALLY SUPPORTIVE FOR THE ACTIVATION OF ICE NUCLEI...SO IT APPEARS THAT THIS IS THE CASE. BOUNDARY LAYER WINDS WILL BACK SUBSTANTIALLY OVER THE NEXT SEVERAL HOURS AND INVERSION HEIGHTS ARE EXPECTED TO LOWER FURTHER...SO THIS LINGERING LAKE EFFECT PCPN SHOULD BE GONE BEFORE DAYBREAK. THE EVOLUTION OF CLOUD COVER THEN BECOMES THE MAIN FORECAST CONCERN THROUGH THE REMAINDER OF TODAY. BOTH THE NAM AND GFS INDICATE THINGS DRYING OUT ALL THE WAY DOWN THROUGH 925 MB BY THIS AFTERNOON...SUGGESTING THAT THE LOW CLOUDS SHOULD TEND TO BREAK UP AS WE PROGRESS THROUGH THE DAY. HOWEVER...THE 11-3.9 MICRON IMAGERY SHOWS EXTENSIVE LOW CLOUDS BACK INTO NORTHWEST MINNESOTA...SO IT MAY TAKE A BIT LONGER THAN ADVERTISED BY THE 00Z GUIDANCE. IN ANY EVENT...WILL ALLOW THINGS TO BECOME PARTLY SUNNY DURING THE AFTERNOON HOURS. SOME AC...WHICH CAN CURRENTLY BE SEEN OVER MANITOBA...WILL MOVE IN BY AFTERNOON...SO EVEN IF THE LOW CLOUDS DISSIPATE MORE QUICKLY THAN EXPECTED...THERE SHOULD STILL BE SOME MID/HIGH CLOUDS TO HELP KEEP TEMPERATURES IN CHECK. THE SHORTWAVE CURRENTLY SEEN MOVING THROUGH NORTHERN ALBERTA WILL DIVE SOUTHEAST OVER THE NEXT 24 TO 36 HOURS...HELPING TO DRIVE A COLD FRONT THROUGH THE AREA MONDAY MORNING. THE GFS IS MORE AMBITIOUS THAN THE NAM...CANADIAN AND UKMET WITH LOWERING 850MB TEMPERATURES BEHIND THE FRONT MONDAY AFTERNOON AND MONDAY NIGHT...BUT EVEN THE WARMER NAM HAS SUFFICIENTLY COLD TEMPERATURES FOR LES BY LATE MONDAY AFTERNOON WITH 850MB TEMPERATURES OF AROUND -10C. THE GFS ACTUALLY COOLS 850MB TEMPERATURES TO AROUND -16C BY TUESDAY MORNING...WHEREAS THE NAM ONLY TAKES THINGS DOWN TO AROUND -12C. THE DEEPER COLD AIR SHOWN BY THE GFS RESULTS IN ITS HAVING HIGHER INVERSION HEIGHTS MONDAY NIGHT INTO EARLY TUESDAY. IT APPEARS THAT THE GFS IS A BIT MORE AMBITIOUS DUE TO ITS MOVING THE EAST COAST SYSTEM UP THE COAST MORE RAPIDLY AND INTENSIFYING IT MORE THAN THE NAM...THEREBY ALLOWING IT TO HOLD ONTO CYCLONIC FLOW AND NORTHEAST TRAJECTORIES OVER OUR AREA FOR A LONGER PERIOD OF TIME. INDEED...THE NAM STARTS TO BACK THE BOUNDARY LAYER FLOW AND BRING RIDGING INTO THE AREA BY MONDAY EVENING...WHILE THE GFS DOESN/T DO THIS UNTIL TUESDAY AFTERNOON. THE UKMET OFFERS SOMEWHAT OF A COMPROMISE ON THESE ISSUES...AND FEEL IT MAY HAVE THE BEST HANDLE ON THINGS. SO...WITH SUFFICIENTLY COLD TEMPERATURES FOR LES AND FAIRLY DEEP MOISTURE FOR AT LEAST A 6 TO 12 HOUR PERIOD...WILL CONTINUE TO MENTION LES AND INCLUDE SOME ACCUMULATIONS TO AROUND 6 INCHES OVER THE 24 HOUR PERIOD FROM MONDAY AFTERNOON INTO TUESDAY AFTERNOON. WITH THE BOUNDARY LAYER FLOW EXPECTED TO BE NNW-NNE...THE SOUTHERN KEWEENAW THROUGH THE PORCUPINE MOUNTAINS AND LOCATIONS FROM BIG BAY TO GRAND MARAIS WILL SEE THE BULK OF THE SNOWFALL. LATER SHIFTS WILL OBVIOUSLY NEED TO KEEP AN EYE ON HOW MUCH COLD AIR AND MOISTURE WILL MAKE IT INTO THE AREA...AND HOW LONG THEY WILL LINGER...SINCE AMOUNTS COULD BE POTENTIALLY HIGHER. ESSENTIALLY MADE NO CHANGES TO THE GOING FORECAST BEYOND TUESDAY. THE GFS STILL POINTS TOWARD AN ALBERTA CLIPPER MOVING THROUGH ON WEDNESDAY...BRINGING A REINFORCING SHOT OF COLD AIR FOR THE BALANCE OF THE WEEK. THERE IS A SUBSTANTIAL DEGREE OF VARIATION IN THE MEDIUM RANGE GUIDANCE AS TO WHAT WILL BECOME OF THIS SYSTEM AS IT MOVES BY OUR AREA...WITH THE GFS LINGERING IT JUST TO OUR EAST FOR A COUPLE OF DAYS WHICH COULD POTENTIALLY PRODUCE A LONG DURATION OF N-NE LES WITH DEEP MOISTURE AND HIGH INVERSION HEIGHTS. THE DAY SHIFT WILL TAKE A CLOSER LOOK AT THE MEDIUM RANGE DETERMINISTIC AND ENSEMBLE GUIDANCE...AND MODIFY THE GOING FORECAST IF NEEDED. AS THINGS CURRENTLY STAND...THE GOING FORECAST MATCHES THE LATEST GFS FAIRLY WELL...WITH SNOW SHOWERS MENTIONED FROM WEDNESDAY INTO FRIDAY. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ TRH mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 320 AM MST SUN NOV 20 2005 .SYNOPSIS...HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH THE UPCOMING WEEK. && .DISCUSSION...MID LEVEL RIDGE CENTERED OVER THE GREAT BASIN PER EARLY MORNING WATER VAPOR IMAGERY...SANDWICHED BETWEEN CUTOFF LOW OFF CA COAST AND DEEPENING LONGWAVE TROUGH ACROSS CENTRAL/EASTERN CONUS. SHORTWAVE TROUGH WHICH GRAZED FORECAST AREA AND COOLED 700MB TEMPS SATURDAY HAS DUG INTO SOUTHERN PLAINS RESULTING IN DEVELOPMENT OF CLOSED LOW ALONG KS/MO BORDER. AS THIS LOW CONTINUES TO DEVELOP AND DIG FURTHER AWAY FROM THE REGION TODAY WARMER 700MB TEMPS OF +3 TO +4...CURRENTLY ALONG THE UT/NV BORDER PER RUC ANALYSIS...WILL SPREAD ACROSS THE ENTIRE FORECAST AREA THIS AFTERNOON. THIS WARMER AIR ALOFT WILL CONSIDERABLY STRENGTHEN VALLEY INVERSIONS...BUT RESULT IN WARMING TEMPERATURES ABOVE BASE OF INVERSION...ROUGHLY 7000 FEET PER PROG NAM SOUNDINGS. REX BLOCK EXPECTED TO DEVELOP TONIGHT INTO MONDAY ALONG PACIFIC COAST...AND CONTINUE TO INFLUENCE THE WESTERN CONUS THROUGH THANKSGIVING. AS A RESULT STAGNANT CONDITIONS WILL REMAIN IN VALLEY LOCATIONS. MAY SEE FOG IN MOUNTAIN VALLEY LOCATIONS ALONG WITH THE CACHE VALLEY THROUGH TUESDAY WITH CONTINUED HAZY CONDITIONS ELSEWHERE. SOME POTENTIAL FOR DEVELOPMENT OF FOG EXISTS BY MIDWEEK ALONG THE WASATCH FRONT...AND IF THIS OCCURS WOULD HAVE A BIG IMPACT ON TEMPERATURES NOT TO MENTION HOLIDAY TRAVELERS. MEDIUM RANGE MODELS SUGGEST LARGE SCALE PATTERN MAY BEGIN TO BREAK DOWN ALONG WEST COAST FRIDAY AS SHORTWAVE TROUGH PROGGED BY GFS/EC/UK/GEM TO MOVE INTO PACIFIC NORTHWEST...THEN POSSIBLY DIG SOUTHWARD THROUGH GREAT BASIN SATURDAY. CONFIDENCE IN MODELS HANDLING OF SHORTWAVE FEATURES DURING LONGWAVE TRANSITION IS FAIRLY LOW...THUS HAVE GENERALLY GONE WITH A PERSISTENCE FORECAST THROUGH THE EXTENDED. && .AVIATION...SEE LATEST SLCTAFSLC. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...NONE. WY...NONE. && $$ SEAMAN ut AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE WAKEFIELD VA 952 AM EST SUN NOV 20 2005 .SHORT TERM (REST OF TODAY)...LATEST RADAR SHWNG SOME LGT RETURNS JUST S OF THE ALBEMARLE SND THIS MRNG. AREA SNDGS TO OUR SOUTH SHOW AMPLE MSTR IN PLACE FOR OVC CONDS AND SHWRS TODAY...WHILE WAL SNDG QUITE DRY EXCEPT FOR SOME MID AND UPR LVL CLDNSS. RUC SNDGS SHOW SOME INCREASE IN LOW LVL MSTR AND LOW LVL CONV INTO NE NC AND EXTREME SRN VA BY THIS AFTN. HAVE SENT UPDATED ZONES TO ADD MORE CLD CVR IN SRN ZONES...LWR TEMPS A FEW DEGREES THERE AND ADD SCHC RAIN IN NC FAR SRN VA. ELSEWHERE...EXPECT PSNNY SKIES AND A HIGH NEAR 60. && .PREVIOUS DISCUSSION... (ISSUED 303 AM EST SUN NOV 20 2005) TODAY...MID/HIGH LVL CLDS ASSCTD WITH S/W RESULTS IN PT SUNNY SKIES. TMPS 55-60. S/W NRGY DIVES SE INTO ERN TROF SPAWNING CYCLOGENSIS OVR NRN FLA TDY. SYSTM BEGINS TO DEEPEN AS IT MOVES NE LATER TODAY AND TONITE. TONITE...CONSENSUS IS TO FOLLOW A GFS SOLN WITH EVOLUTION AND TRACK OF ENERGENIC SYSTM NXT 24-48 HRS. WAA PCPN XPCTD TO DVLP ACROSS SRN HALF OF FA THIS EVE...THEN SPREAD NE OVRNITE. LOWS FM U30S MD ERN SHORE TO NR 50 SE. MONDAY / MONDAY NITE...DEEPENING LOW TRACKS NE ALONG NC CSTL PLAIN TO CHES BAY AND DELMARVA CNTYS...A BIT FRTHR E THAN THOUGHT YSTRDY. TMPS WILL BE HIGHLY DEPENDENT ON WHERE TRIPLE PT LOW TRACKS. SERN AREAS SHUD SEE L60S WHILE NW CNTYS STAY NR 50. SHUD GET RTHR BREEZY ALONG CSTL SCTNS AS WELL. WDSPRD RAIN OVRSPRDS ENTIRE FA...WILL LIMIT THUNDER CHC TO TIDEWATER VA / NE NC CNTYS BRDRG ALBERMARLE SND WHERE BEST INSTBLTY PROGGED. BEST LIFT/VV'S AFTR 18Z. RNFL CUD GET HVY AT TIMES MON AFTRN /EVE (PW'S OF 1.5 INCHES) DEPENDING ON AMT OF TRPLCL MSTR THAT GETS TAPPED FROM GOM. XPCTD QPF BTWN .5 - 1.5 INCHES B4 ALL SAID & DONE. SYSTM RACES NE TO A PSN OFF NJ COAST BY MIDNITE THEN TO NR LONG ISLAND BY 12Z TUE. RAIN GRDLY TAPER OFF MON NITE. TUESDAY...LINGERING UP LVL NRGY CONT CHC SHWRS. BIGGEST STORY HERE WILL BE GUSTY WNDS BEHIND DEPARTING SYSTM. TMPS NRLY STDY IN THE U40S - M50S. WEDNESDAY...COOL / DRY. TURKEY DAY...ANTHR ENERGENIC S/W DIVES SE FROM GT LAKES RGN INTO PA WITH ASSCTD CDFRNT PROGGED ACROSS FA. XPCT CHC SHWRS WITH THIS BNDRY. FRIDAY / SATURDAY...CYCLONIC FLOW SETS UP ACROSS FA AS UPL LVL CLOSED LOW ACROSS GT LAKES SLOWLY LIFTS NE INTO ERN CANADA. THIS TYPICALLY RESULTS IN COOL BUT DRY WX HERE. AVIATION...MAINLY VFR. AREAS OF MID AND HIGH CLOUD TODAY...WITH SOME LOWERING CIGS...MAINLY SRN LOCATIONS...THIS EVENING. CIGS REMAINING VFR THROUGH 6Z MON. MARINE...GENERALLY LIGHT WINDS AND SEAS THROUGH TONIGHT. CONDITIONS DETERIORATE RAPIDLY ON MONDAY...AS DEVELOPING CYCLONE MOVES UP FROM THE SOUTH. HAVE GONE JUST A TAD UNDER WAVEWATCH...WHICH GENERATES SEAS OFF THE GFS WIND FORECAST... FOR THE MON AND TUE PERIOD...WITH SEAS AS HIGH AS 7 TO 9 FT MON AFTERNOON AND NIGHT. MAY APPROACH GALES...BOTH WITH THE CYCLONE...AND THEN AGAIN TUE WITH STG CAA...BEHIND A COLD FRONT AS LOW LIFTS N OF THE AREA. AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FOR ANZ656-658 FROM 9 AM MONDAY TO 1 AM WEDNESDAY. ...SMALL CRAFT ADVISORY FOR ANZ650-652-654 FROM 3 PM MONDAY TO 1 AM WEDNESDAY. $$ SHORT / LONG TERM...44 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FOR ANZ656-658 FROM 9 AM MONDAY TO 1 AM WEDNESDAY. ...SMALL CRAFT ADVISORY FOR ANZ650-652-654 FROM 3 PM MONDAY TO 1 AM WEDNESDAY. && $$ SHORT TERM...BROWN va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 150 PM EST SUN NOV 20 2005 .SHORT TERM (TONIGHT THROUGH TUESDAY)... WHILE THIS WON'T BE A DROUGHT-BUSTER BY ANY STRETCH... IT LOOKS LIKE EVERYONE SHOULD SEE AT LEAST SOME RAIN DURING THIS PERIOD. IN THE NEAR TERM... THE LATEST WATER VAPOR IMAGERY AND RUC DATA INDICATE INCREASING JETS ACROSS NORTHERN MEXICO AND OVER MS AND CENTRAL TN... SUPPORTING CONVECTION JUST SOUTH OF LA. AS THIS SECOND JET SPEEDS UP FURTHER TO OUR NORTH ALONG WITH THE INCREASING SUBTROPICAL JET PUSHING INTO FL TONIGHT... STRONG UPPER DIVERGENCE ASSOCIATED WITH THE EXISTING BAROCLINIC ZONE OFFSHORE SHOULD BRING SWIFT CYCLOGENESIS OFF THE SC COAST LATE TONIGHT. THE 850 MB WARM FRONT MOVING NORTH INTO THE CWA THROUGH MONDAY SHOULD ACT AS A FOCUS FOR WIDESPREAD RAIN WITH STRONG ISENTROPIC UPGLIDE ON THE 300K SURFACE... AND WILL BRING IN CATEGORICAL POPS MAINLY AFTER MIDNIGHT TONIGHT FROM SOUTHEAST TO NORTHWEST... CONTINUING THROUGH MONDAY MORNING. AS THE 850 MB WARM FRONT AND THE BULK OF THE UPPER DIVERGENCE BOTH HEAD TO OUR NORTH BY MONDAY AFTERNOON... WILL TAPER RAIN CHANCES DOWN TO CHANCE POPS FOR MONDAY AFTERNOON AND EVENING WITH THE ISENTROPIC UPGLIDE DIMINISHING. RAINFALL AMOUNTS MAY SEE A RELATIVE MINIMUM OVER CENTRAL NC WITH THE POTENTIAL FOR RAIN TO BE MORE CONCENTRATED NEAR THE COASTAL FRONT OVER EASTERN NC/SC WITH A LESSER MAX IN THE UPSLOPE REGIONS WEST OF THE CWA. SEVERE THREAT LOOKS MARGINAL WITH GOOD SHEAR BUT LOW CAPE. WILL INCLUDE AN ISOLATED THUNDER THREAT IN THE EASTERN SECTIONS... AND WILL HAVE TO WATCH ANY CONVECTIVE CELLS WHICH FORM NEAR OR JUST NW OF THE COASTAL FRONT. THEN THE MODELS CONTINUE TO DIFFER A BIT ON THE SPEED AND EVOLUTION OF THE MID LEVEL VORTEX THAT CROSSES THE REGION MONDAY NIGHT INTO TUESDAY... HOWEVER THE RAINFALL PATTERN IS NOT APT TO BE MUCH DIFFERENT WITH EXPECTATIONS OF A COASTAL LOW OFF NORTHEAST NC BY LATE MONDAY WITH A SECONDARY CIRCULATION FARTHER SW OVER WESTERN SC BENEATH THE MID LEVEL CIRCULATION. THE HPC-PREFERRED GFS HINTS AT DRYING ALOFT LATE MONDAY AS THE JETLET NOW SHOWN ON WATER VAPOR DIVING INTO THE WEST SIDE OF THE UPPER VORTEX WRAPS AROUND TO ITS SOUTHEAST SIDE... BUT WITH THE LOW LEVELS STAYING MOIST AS 850 MB WINDS DON'T GO NORTHWESTERLY UNTIL TUESDAY MORNING... WILL LEAVE IN LOW CHANCE POPS UNTIL MIDDAY TUESDAY WITH CLEARING AND DRYING THEREAFTER. REGARDING TEMPS... EXPECT GOOD DEWPOINT RISES ESPECIALLY EAST OF HIGHWAY ONE TONIGHT AND WILL GO WITH LOWS IN THE MID 40S NW TRENDING TO LOWER 50S SOUTHEAST. TEMP RISES MONDAY SHOULD BE LITTLE MORE THAN A CATEGORY OR TWO. WILL GO WITH CONSENSUS OF MOS GUIDANCE NUMBERS MONDAY NIGHT THROUGH TUESDAY. -GIH && .LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... TUESDAY NIGHT AND WEDNESDAY: THE NAM AND GFS AGREE WELL IN TAKING A CLIPPER VORTICITY MAX DIVING THROUGH THE TROUGH BASE THROUGH NORTH AND SOUTH CAROLINA TUESDAY NIGHT... BUT PRECEDING NORTHWESTERLY FLOW FROM THE SURFACE THROUGH 850 MB SHOULD KEEP ANY PRECIP ALOFT FROM REACHING THE GROUND. WILL GO WITH MOSTLY CLOUDY SKIES WITH LOWS 28-35. EXPECT BRIEF CLEARING WEDNESDAY WITH CHILLY TEMPS. ENSEMBLE MOS GUIDANCE AND PROGGED THICKNESSES POINT TO HIGHS AT LEAST 10 DEGREES BELOW NORMAL... REASONABLE FOR THIS TYPE OF PATTERN AND INCOMING AIR MASS AND WILL REDUCE MAX TEMPS TO THE MID 40S TO LOWER 50S. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT: MODELS ARE IN GENERAL AGREEMENT ON A FORMIDABLE CLIPPER DIVING DOWN FROM THE MIDWEST DURING THIS PERIOD. THE OP GFS LOOKS TO BE THE STRONGEST WITH A VORTICITY MAX TRACKING ACROSS NC LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING. THE 12Z RUN TAKES IT ON A SLIGHTLY MORE NORTHERLY TRACK THAN ITS 06Z (CROSSING NC RATHER THAN SC) WHICH HELPS LEAD TO WARMER THICKNESSES (ABOUT 1315 M AT RDU ON THE 12Z RUN VERSUS 1305 M ON THE 06Z RUN). WHILE THERE ISN'T MUCH OPPORTUNITY FOR MOISTURE INFLOW AHEAD OF THIS FRONT DESPITE A PERIOD OF SOUTHWESTERLY BOUNDARY LAYER WINDS... IF THE CLIPPER IS STRONG ENOUGH WITH A MORE CONCENTRIC-SHAPED VORTICITY MAX... THE DYNAMICS ALONE COULD BE ENOUGH TO WRING OUT SOME PRECIP EAST OF THE MOUNTAINS. THICKNESSES AND SURFACE TEMPS AND DEWPOINTS FROM THE NEWEST GFS INDICATE THIS WOULD IN ALL LIKELIHOOD BE ALL LIQUID... ALTHOUGH WE HAVE SEE WHAT VERY STRONG DYNAMIC COOLING IS CAPABLE OF IN THE PAST. WHILE CONFIDENCE IN AN ALL-LIQUID SCENARIO IS FAIRLY HIGH... WILL NEED TO WATCH OUT FOR THIS SYSTEM OVER THE NEXT FEW DAYS. WILL CARRY JUST CHANCE POPS FOR NOW... MAINLY AFTER MIDNIGHT WEDNESDAY NIGHT AND ENDING BY THURSDAY AFTERNOON WITH MOSTLY CLOUDY SKIES. LOWS 35-39... HIGHS 50-58... THEN LOWS THURSDAY NIGHT 29-35. FRIDAY THROUGH SUNDAY: POSITIVE PNA PATTERN PERSISTS WITH THE LARGE COLD MID LEVEL VORTEX SPINNING AROUND TO OUR NORTH AS A CHILLY SURFACE HIGH BUILDS ACROSS NC FROM THE WEST. EXPECT MOSTLY CLEAR SKIES AND TEMPS MUCH BELOW NORMAL. SOME INCREASE IN CLOUDS IS POSSIBLE SUNDAY WITH INCREASING SUBTROPICAL FLOW ALOFT COMING OUT OF THE EXPECTED CLOSED LOW OVER THE SOUTHWEST U.S. -GIH && .AVIATION... CEILINGS WILL LOWER TO IFR/LIFR AND RAIN WILL OVERSPREAD FROM THE SOUTH THIS EVENING AND TONIGHT AS SECONDARY GULF WAVE APPROACHES THE AREA. EXPECT HEAVIEST RAINFALL AND LOWEST CEILINGS ACROSS THE SOUTH AND EAST...WITH LESS RAIN AND SLIGHTLY HIGHER CEILINGS TOWARDS THE NORTHWEST DURING THE LATE NIGHT TO MORNING HOURS. VISIBILITY SHOULD VARY FROM 5 TO 2SM WITH HEAVIER RAINFALL. ANOTHER AREA OF RAIN WILL DEVELOP ACROSS THE WEST IN AFTERNOON AS PRIMARY UPPER LOW APPROACHES FROM THE SOUTHWEST. BEST RAIN CHANCES AND IFR CEILINGS THEN SHIFT TO THE WEST WITH A DECREASE TO THE EAST. -BL && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...LOCKLEAR nc