Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/19/13


AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1000 PM MST SAT NOV 16 2013 .UPDATE... ISSUED AT 950 PM MST SAT NOV 16 2013 SNOW LEVELS WERE AROUND 6.5KFT NORTH TO 8.5KFT SOUTH WITH CONVECTION PULLING IT LOWER LOCALLY. A QUICK REVIEW OF SNOTEL SITES TOTAL STORM AMOUNTS: IN EASTERN UTAH MTNS 1-4 INCHES. IN WESTERN COLORADO IN THE NORTHERN MTNS 6-12 INCHES WITH HIGHER AMOUNTS NEAR THE WYOMING BORDER AND NORTH SIDE OF THE FLATTOPS. CENTRAL MTNS 5-10 INCHES WITH 17 INCHES AT SCHOFIELD PASS. SOUTHERN MTNS 6-15 INCHES FAVORING THE NW SAN JUANS BUT MOLAS PASS HAS GOTTEN AROUND 15 INCHES. THE SNOW LULL EARLY SATURDAY MORNING IS EVIDENT IN MOST GRAPHS. THE 120KT JET NOSE IS ORIENTED FROM POCATELLO TO PAGOSA SPRINGS THIS EVENING AND WILL LIFT NE OUT OF THE FORECAST AREA BY SUNRISE. THE UPPER LEVEL SUPPORT FOR THIS STORM IS SHIFTING EAST OF THE CONTINENTAL DIVIDE. AFTER MIDNIGHT THE FORECAST AREA WILL GENERALLY BE IN THE COLD ADVECTIVE NW FLOW THAT CAN PRODUCE GOOD SHALLOW CONVECTIVE SNOWFALL ALONG NW FACING SLOPES. THE ELKHEADS/PARK/GORE/FLATTOPS/ELKS/WEST ELKS LOOK TO BE FAVORED WITH SNOWFALL OVERNIGHT WITH THE NEW NAM12 PRODUCING UP TO 6 NEW INCHES. THE SAN JUANS ARE PROGGED TO RECEIVE LESS AND THE UNCOMPAHGRE GORGE DOES NOT LOOK FAVORED WITH TEMPERATURES TOO MILD AND THE MTN TOP WINDS FROM THE WNW WHICH IS NOT FAVORABLE. SNOW ACCUMULATIONS SUNDAY MORNING LOOK TO BE LIGHT...SO MOST HIGHLIGHTS WILL LIKELY END WITH SUNRISE. THE NW COLORADO MTNS HIGHLIGHTS MAY STAY IN EFFECT UNTIL NOON WITH LIGHT SNOW FALLING IN THE MORNING HOURS. THE BROAD TROUGH REMAINS OVER THE WEST WITH SOME CHANCE OF MTN SNOWS TUESDAY AND ESPECIALLY THURSDAY AND PERHAPS INTO NEXT WEEKEND IF THE GFS IS FOLLOWED. && UPDATE ISSUED AT 525 PM MST SAT NOV 16 2013 JET AXIS WILL TRANSLATE ACROSS NWRN COLORADO TONIGHT...EXPECT THIS TO ENHANCE OROGRAPHIC SNOW THIS EVENING. EXPECT ONE MORE BURST OF HEAVY SNOW RATES BEFORE THE FLOW ALOFT BECOMES ANTICYCLONIC AND THE MOISTURE ERODES FROM THE WEST (ALREADY UNDERWAY). RAP AND HRRR MODELS SEEM TO INDICATE THAT AREAS EAST OF CRAIG WILL GET DECENT SNOW ACCUMULATIONS THIS EVENING. ELECTED TO HOIST WINTER WEATHER ADVISORY FOR THE STEAMBOAT SPRINGS VICINITY. CONSIDERED CRAIG/MEEKER AND GLENWOOD SPRINGS/EAGLE AREAS AS WELL...BUT APPEARS THAT SNOWFALL WILL NOT REACH THE 2-4 INCH RANGE FOR THESE LOCATIONS. THE I-70 CORRIDOR IS LESS LIKELY TO EXCEED 1 INCH...BUT SPOTTY ACCUMULATIONS ON GRASSY SURFACES MAY OCCUR. THE WIND ADVISORY DID NOT PAN OUT IN THE MOIST POST FRONTAL ENVIRONMENT AND HAS BEEN CANCELLED 1 HOUR EARLY. && .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 248 PM MST SAT NOV 16 2013 WINTER WEATHER PRODUCTS WILL CONTINUE FOR MOST OF THE WRN CO MOUNTAINS. ONE SHORTWAVE TROUGH OVER NORTHERN AND CENTRAL CO THIS AFTERNOON WILL MOVE EAST AND PRODUCE SNOWFALL IN THE MOUNTAINS AND MIX OF RAIN AND SNOW IN THE HIGHER VALLEYS THROUGH THIS EVENING. A BRIEF LULL SHOULD OCCUR IN THE LATE EVENING...THEN ANOTHER WEAKER SHORTWAVE WILL MOVE OVER THE NORTHERN HALF OF CO FROM JUST BEFORE MIDNIGHT TO JUST BEFORE SUNRISE. SKIES SHOULD CLEAR FROM WEST TO EAST SUNDAY MORNING. TEMPS...MOISTURE AND COLD ADVECTION ARE ALL GOOD FOR DECENT SNOW ACCUMULATION. THE 700 MB TEMPS DROPPING TO -6 AND -7 DEGREE C TONIGHT WILL BRING SNOWFALL DOWN TO VALLEY BOTTOMS LATE. STEADY WNW ALOFT WILL PROVIDE GOOD OROGRAPHIC SUPPORT FOR SNOWFALL ON WEST AND NORTHWEST FACING SLOPES. SUNDAY AND SUNDAY NIGHT SHOULD SEE DRAMATICALLY CLEARING SKIES. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 248 PM MST SAT NOV 16 2013 MONDAY WILL BE CALM AND UNEVENTFUL AS LIGHT WESTERLY WINDS FROM WEAK RIDGING TAKE OVER THE WEATHER PATTERN. TEMPERATURES WILL ADVANCE BACK UP TO NEAR NORMAL MONDAY AND TUESDAY BEFORE A WEAK WAVE SWINGS BY THE NORTHERN COUNTIES THURSDAY NIGHT...PRODUCING CLOUDY CONDITIONS AND A TRACE OF PRECIPITATION AT BEST ALONG THE CO/WY BORDER. THE 12Z MODELS MOVE IN A WEAK UPPER LEVEL TROUGH WHICH BRINGS A CHANCE OF PRECIPITATION TO THE HIGHER ELEVATIONS WEDNESDAY AFTERNOON. THE BIG STORY IN THE LONG RANGE WILL BE A SYSTEM APPROACHING LATE WEEK...POTENTIALLY EARLY THURSDAY OR POTENTIALLY FRIDAY DEPENDING ON WHICH WX MODEL YOU ARE ANALYZING. CONFIDENCE IS LOW AS THE MODELS DIVERGE ON TIMING AND SPATIAL COVERAGE OF THIS LATE WEEK FEATURE. NONETHELESS...THE LAST FEW MODEL RUNS HAVE BEEN SIGNALING A STRONG STORM THROUGHOUT THE GREAT BASIN FOR A COUPLE OF DAYS NOW SO CONFIDENCE IS MODERATE FOR AN INTERESTING WX SYSTEM TO UNFOLD LATE IN THE WEEK INTO THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 950 PM MST SAT NOV 16 2013 PRECIPITATION WILL CONTINUE TONIGHT WITH PERIODS OF LOWERED CIGS AND LOWERED VSBYS. WIDESPREAD MTN SNOW SHOWERS WILL BECOME SCT TOWARDS MORNING. FOG MAY DEVELOP BETWEEN SNOW SHOWERS KEEPING VISIBILITY DOWN INTO EARLY SUNDAY MORNING WITH GRADUAL IMPROVEMENT THEREAFTER. EXPECT WIDESPREAD MVFR CIGS AND VSBYS WITH THE HEAVIER SHOWERS WITH MOUNTAINS FQTLY OBSCD INTO SUNDAY MORNING. LOCAL IFR TO LIFR CIGS WILL BE FOUND NEAR THE STRONGER SHOWERS. IN ADDITION...GUSTY NORTHWEST WINDS WILL BE COMMON ACROSS THE REGION...WITH SPEEDS EXCEEDING 40 KTS AT AND ABOVE MTN TOP LEVEL. EXPECT AREAS OF MODERATE TO STRONG TURBULENCE THROUGH THIS PERIOD. PRECIPITATION AND GUSTY WINDS WILL END THROUGHOUT THE MORNING SUNDAY FROM WEST TO EAST WITH VFR CONDITIONS EXPECTED SUNDAY AFTERNOON AND EVENING. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR COZ003-005-009- 014-017-018. WINTER STORM WARNING UNTIL 6 AM MST SUNDAY FOR COZ012-019. WINTER STORM WARNING UNTIL 11 AM MST SUNDAY FOR COZ004-010-013. UT...NONE. && $$ UPDATE...JOE SHORT TERM...CC LONG TERM...JAM AVIATION...JOE
AREA FORECAST DISCUSSION
NWS ALBANY NY
630 PM EST MON NOV 18 2013 .SYNOPSIS... AS COLDER AIR WORKS INTO THE REGION TONIGHT...LAKE ENHANCED RAIN AND SNOW SHOWERS WILL AFFECT WESTERN AND NORTHERN PARTS OF THE AREA. TEMPERATURES TOMORROW WILL BE MUCH COLDER THAN RECENT DAYS...WITH A GUSTY WESTERLY WIND. HIGH PRESSURE PASSING OVER THE AREA WILL ALLOW FOR DRY WEATHER FOR THE REMAINDER OF THE WORK WEEK...WITH TEMPERATURES SLOWLY MODERATING BACK TO NORMAL LEVELS. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 530 PM EST...COLD FRONT JUST SLIPPED SOUTH OF I90 PER THE DUAL POL RADAR DATA. SOME SHOWERS HAVE DEVELOPED ON THE UPSLOPE AREAS OF THE SCHOHARIE VALLEY AND HELDERBERGS AND WITH THE MEAN WESTERLY FLOW...THESE ISOLATED SHOWERS HAVE MOVED INTO THE CAPITAL REGION. FURTHERMORE...TERRAIN ENHANCEMENT ACROSS THE SOUTHERN GREENS HAVE TOO INITIATED SOME SHOWERS. SO WE WILL INCREASE POPS/WX THROUGH THE EVENING HOURS AND WATCH LAKE EFFECT ACTIVITY PICK UP DOWNWIND OF LAKE ONTARIO. PER THE RUC13 LOW LEVEL CONVERGENCE FIELDS...SEEMS BAND/S/ OF PRECIP SHOULD INCREASE ACROSS CENTRAL HERKIMER COUNTY WITH A TENDENCY TO SLIDE SOUTHWARD AND WEAKEN OVERNIGHT. THE CURRENT FORECAST ACROSS THAT PART OF THE CWA REMAINS IN EXCELLENT SHAPE. OTHERWISE...PER HOURLY TEMPS...DID SLOW DOWN THE NOCTURNAL CURVE A BIT AND CLOSER TO THE LAMP/LAV AND 2KM HRRR/RUC13. AS OF 400 PM EST...A STRONG AND VERTICALLY STACKED STORM SYSTEM OVER WESTERN QUEBEC WILL FILL IN AND WEAKEN OVERNIGHT. WITH THE TROUGH AXIS CENTERED OVER THE NORTHEASTERN US...THE CYCLONIC FLOW AROUND THE UPPER LOW WILL PASS OVER THE NORTHERN AND EASTERN GREAT LAKES. INITIALLY...THE LOW TO MID LEVEL FLOW WILL BE IN A W-SW DIRECTION...WHICH WILL ALLOW FOR SOME LAKE ENHANCED RAIN AND SNOW SHOWERS THIS EVENING OVER THE NORTHWESTERN ADIRONDACKS...AS STRONG CAA DROP 850 HPA TEMPS FROM AROUND 0 TO +4 DEGREES C THIS AFTN...TO -8 TO -12 DEGREES C BY LATE TONIGHT. AS BOUNDARY LAYER TEMPS ALSO COOL DOWN...PTYPE WILL CHANGE TO SNOW ACROSS THE REGION. THE MEAN WIND SHIFTS TO THE WEST DURING THE OVERNIGHT HOURS AND EVENTUALLY NORTHWEST BY LATE TONIGHT. OUR LOCAL WFOWRF...AS WELL AS THE LATEST 3KM HRRR...ALL SUGGEST THAT SOME OF THIS LAKE ENHANCED ACTIVITY WILL PASS ACROSS WESTERN AND NORTHERN PARTS OF OUR AREA DURING THE OVERNIGHT HOURS. DUE TO THE EXPECTED AMOUNTS OF SHEAR AND WIND DIRECTION...THE ACTIVITY WILL GENERALLY BE MULTI-BAND IN NATURE...AND THE INVERSION HEIGHT OF ONLY 2.5-3 KM WILL PREVENT ANY MEANINGFUL SNOW BANDS FROM OCCURRING. WHILE THE BULK OF THE ACTIVITY WILL EITHER BY ACROSS THE HIGH TERRAIN OR THE WESTERN MOHAWK VALLEY...IT/S POSSIBLE THAT A FLURRY OR SPRINKLE MAY MAKE IT INTO THE HUDSON VALLEY REGION AND CAPITAL REGION BY LATE TONIGHT. NO SNOW ACCUMULATION IS EXPECTED FOR THE CAPITAL REGION/HUDSON VALLEY AREAS. ELSEWHERE..SNOW ACCUM WILL RANGE FROM JUST A DUSTING TO UP TO TWO INCHES ACROSS THE WESTERN ADIRONDACKS. TEMPS WILL BE MUCH COLDER FOR TONIGHT THAN RECENT NIGHTS...WITH MINS RANGING FROM THE MID 20S TO MID 30S. IN ADDITION...THE W-NW SFC WIND WILL CONTINUE TO BE GUSTY OVERNIGHT...WITH SUSTAINED WINDS OF 10 TO 20 MPH WITH A FEW HIGHER GUSTS...ESP FOR THE MOHAWK VALLEY AND CAPITAL REGION. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... WITH SFC HIGH PRESSURE BUILDING INTO THE REGION ON TUESDAY AND THE FLOW ALOFT BECOMING ANTICYCLONIC AND INVERSION HEIGHTS LOWERING...LAKE EFFECT ACTIVITY WILL END. A FEW SNOW SHOWERS ARE POSSIBLE EARLY IN THE DAY ACROSS SCHOHARIE COUNTY AND THE EASTERN CATSKILLS...OTHERWISE IT WILL BE DRY UNDER A PARTLY TO MOSTLY SUNNY SKY WITH A CONTINUED GUSTY NW BREEZE. TEMPS WILL BE MUCH COLDER THAN RECENT DAYS...WITH MAX TEMPS IN THE 30S TO MID 40S ACROSS THE REGION. AS THE HIGH PRESSURE AREA BUILDS INTO THE REGION FOR TUESDAY NIGHT...THE WIND WILL DIE OFF AND THIS SHOULD ALLOW FOR GOOD RADIATIONAL COOLING. TEMPS WILL BE VERY COLD TOMORROW NIGHT...WITH TEMPS RANGING FROM THE SINGLE DIGITS OVER THE CENTRAL ADIRONDACKS TO THE TEENS AND LOW 20S ELSEWHERE. THE HIGH PRESSURE AREA WILL REMAIN SITUATED OVER THE NORTHEAST FOR WEDNESDAY THROUGH THURSDAY AS WELL...KEEPING THE DRY WEATHER IN PLACE. MAX TEMPS ON WED WILL BE COLD ONCE AGAIN...WITH 30S AND LOW 40S. HOWEVER...WITH A LIGHT SOUTHERLY WIND DEVELOPING FOR WED NIGHT AND A FEW MORE CLOUDS ACROSS THE AREA...MIN TEMPS WON/T BE AS COLD FOR WED NIGHT...WITH 20S OVER THE MAJORITY OF THE AREA. TEMPS WILL START TO MODERATE ON THURSDAY AS OUR REGION WILL BE IN A RETURN FLOW AROUND THE SLOWLY DEPARTING HIGH...WITH 40S ACROSS THE ENTIRE REGION...AND A FEW MORE CLOUDS AROUND...ESP FOR WESTERN PARTS OF THE AREA. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE PERIOD BEGINS WITH THE PASSAGE OF A COLD FRONT THAT WILL BRING VERY LITTLE MOISTURE AND THUS LITTLE IN THE WAY OF PRECIPITATION. BUT LOW PRESSURE STRENGTHENING ALONG THE FRONT OVER THE OHIO VALLEY ON FRIDAY WILL RAPIDLY BUILD MOISTURE INTO THE REGION. THE LOW WILL TRACK ALONG THE MID-ATLANTIC REGION AND UP THE NEW ENGLAND COAST FRIDAY NIGHT AND SATURDAY...A TRAJECTORY WHICH COULD RESULT IN OUR FIRST SIGNIFICANT WINTER WEATHER EVENT...CONSISTING OF A MIXED BAG OF PRECIPITATION TYPES. A WEST TO NORTHWESTERLY FLOW BEHIND THE SYSTEM ON SUNDAY WILL DRAW IN SIGNIFICANTLY COLDER AIR AND TURN ON THE LAKE EFFECT MACHINE... WITH A GOOD CHANCE FOR SNOW SHOWERS FROM SATURDAY AFTERNOON THROUGH SUNDAY. THIS COULD BE WET SNOW FOR THE MID HUDSON VALLEY. WITH THE FLOW WEAKENING SUNDAY NIGHT...LAKE EFFECT SHOULD BECOME LIMITED TO THE WESTERN ADIRONDACKS...ALTHOUGH MOST REMAINING LOCATIONS WILL STILL HAVE A SLIGHT CHANCE OF SEEING SOMETHING. BY MONDAY...THINGS SHOULD BE QUIETED DOWN AS HIGH PRESSURE RIDGES IN FROM THE SOUTHERN APPALACHIANS. THERE WILL BE A GOOD MIX OF SUN AND CLOUDS MONDAY...B UT LITTLE BOUNCE BACK IN TEMPERATURES. LOWS THURSDAY AND FRIDAY NIGHTS WILL RANGE FROM THE MID OR UPPER 20S TO THE MID 30S. BEHIND THE WEEKEND STORM SYSTEM...LOWS WILL BE IN THE UPPER TEENS AND THE 20S SATURDAY NIGHT. THEY WILL RANGE FROM ONLY AROUND 10 DEGREES IN THE ADIRONDACKS...TO AROUND 20 DEGREES IN THE MID HUDSON VALLEY SUNDAY NIGHT. HIGH TEMPERATURES WILL RANGE FROM THE MID 30S IN THE WESTERN ADIRONDACKS...TO AROUND 50 DEGREES IN THE MID HUDSON VALLEY ON FRIDAY...COOLING TO FROM AROUND 30 TO THE MID 40S ON SATURDAY...THE LOWER 20S TO MID 30S ON SUNDAY...WITH A COUPLE OF DEGREES OF BOUNCE BACK IN THE NORTHWESTERN HALF OF THE FORECAST AREA FOR MONDAY. NORMAL TEMPERATURES FOR ALBANY DURING THIS PERIOD ARE MID 40S FOR HIGHS AND AROUND 30 FOR LOWS. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... A COLD FRONT ALONG WITH UPSLOPE CONDITIONS HAS RESULTED IN SOME SHOWER DEVELOPMENT BUT ITS RATHER ISOLATED AND HAVE PLACED A VCSH FOR A FEW HOURS THIS EVENING. FLIGHT CONDITIONS SHOULD REMAIN VFR...HOWEVER...UPSTREAM SOLID AREA OF STRATUS WAS CLOSE TO MVFR AS WE WILL TREND THE TAFS IN THIS DIRECTION OVERNIGHT. LAKE EFFECT ACTIVITY MAY BRING SOME SHOWERS INTO KALB-KGFL-KPSF AS WE WILL PLACE A PROB30 AROUND 09Z-12Z. DURING THE DAYLIGHT HOURS TUESDAY...IMPROVING CONDITIONS TO VFR IS EXPECTED. WINDS ARE ANOTHER ISSUE WITH RATHER GUSTY WEST-NORTHWEST WINDS THAT WILL CONTINUE TONIGHT AND ESPECIALLY THROUGH THE DAYLIGHT HOURS TUESDAY WITH GUSTS FREQUENTLY OVER 20KTS. OUTLOOK... TUESDAY NIGHT-THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN...RA. FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...RA...SN...SLEET. && .HYDROLOGY... NO HYDRO ISSUES ARE EXPECTED OVER THE NEXT FIVE DAYS. LAKE EFFECT RAIN AND SNOW SHOWERS WILL AFFECT THE ADIRONDACKS AND MOHAWK VALLEY TONIGHT...WITH UP TO A QUARTER OF AN INCH OF LIQUID EQUIVALENT PRECIPITATION EXPECTED. THIS PRECIP WILL HAVE LITTLE TO NO EFFECT ON AREA WATERWAYS. ANY LAKE EFFECT ACTIVITY WILL END ON TUESDAY MORNING...AS HIGH PRESSURE BUILDS INTO THE AREA. HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER OVER THE REGION THROUGH THURSDAY...ALLOWING FOR DRY WEATHER. THIS WILL ALLOW RIVERS AND STREAMS TO HOLD STEADY OR RECEDE...WITH FLOWS EXPECTED TO BE AROUND SEASONAL LEVELS. A STORM SYSTEM LOOKS TO MOVE ACROSS THE REGION SOMETIME BETWEEN FRIDAY AND NEXT WEEKEND...WITH RAIN AND SNOW POSSIBLE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS/BGM SHORT TERM...FRUGIS LONG TERM...ELH AVIATION...BGM HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1002 AM EST SUN NOV 17 2013 .SYNOPSIS... HIGH PRESSURE ALONG THE EASTERN SEABOARD WILL SLIDE OUT TO SEA TODAY. A POWERFUL STORM WILL MOVE FROM THE UPPER GREAT LAKES TOWARD JAMES BAY SUNDAY NIGHT INTO MONDAY. IT WILL BRING WINDY CONDITIONS TO THE REGION...AND DRIVE A COLD FRONT ACROSS THE REGION MONDAY MORNING. MUCH COLDER AIR WILL POUR INTO THE REGION MONDAY NIGHT AND TUESDAY WITH SOME CLOUDS AND SNOW SHOWERS. HIGH PRESSURE WILL BUILD FROM ONTARIO TO THE GULF COAST TUESDAY...THEN SETTLE OVER OUR REGION MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... ...SLIGHT RISK FROM SPC HAS BEEN EXPANDED TO INCLUDE THE ENTIRE REGION THROUGH TONIGHT... AS OF 930 AM EST...LOW STRATUS AND DRIZZLE HAVE QUICKLY EVOLVED ACROSS THE SOUTHERN HALF OF OUR COUNTY WARNING AREA AND HAVE EXPANDED THE POPS AND MENTION OF DRIZZLE THROUGH THE REMAINDER OF THE MORNING HOURS. TEMPERATURE ANALYSIS REVEALS THE COLDER AIR HAS REMAINED LOCKED IN ACROSS THE EASTERN GREENS OF SOUTHERN VERMONT WHERE MID-UPR 30S RESIDE WITH THE WESTERN GREENS WELL INTO THE 50S. SO WE HAVE MODIFIED HOURLY TEMPS A BIT TO MATCH UP BETTER WITH OBSERVATIONS. PER THE 12Z SOUNDING HERE...AMPLE LOW LEVEL MOISTURE BELOW THE STRENGTHENING INVERSION AROUND H850 AND INCREASING LOW LEVEL SHEAR HAS BEEN THE RESULT OF THE DRIZZLE EXPANDING. THIS IS ALSO CONFIRMED WITH THE LATEST VWP REVEALING AMPLE LOW LEVEL SHEAR AND NO ECHOES IN THE MID LEVELS /TOO DRY/ BETWEEN 8K-11K FEET. REGIONAL RADAR SHOWS SHOWERS/PERIODS OF RAIN ACROSS WESTERN AND CENTRAL NY WITH EXPECTATIONS OF THIS REACHING THE WESTERN MOHAWK VALLEY AND DACKS LATER THIS MORNING. THIS SHOULD EXPAND ACROSS MOST OF EASTERN NY AND INTO THE UPSLOPE ENHANCEMENTS OF WESTERN NEW ENGLAND LATER THIS AFTERNOON PER THE LATEST HRRR REFLECTIVITY. BROAD INCREASING ISENTROPIC LIFT AND WARM MOIST ADVECTION WILL BE SURE TO KEEP CLOUDS AND THAT EXPANDING AREA OF SHOWERS IN THE FORECAST WITH LITTLE CHANGES TO THE POPS/WX FOR THE LATER AFTERNOON HOURS. A VERY POWERFUL NEGATIVELY TROUGH AND ASSOCIATED COLD FRONT WILL BE PLOWING THROUGH THE OHIO VALLEY LATER TODAY. THIS FRONT COULD MAKE WEATHER HISTORY IN THAT IT COULD SPAWN AN UNUSUAL PLETHORA OF SEVERE WEATHER IN THOSE AREAS...ESPECIALLY CONSIDERING IT IS MID NOVEMBER. PLEASE REFER TO THE LATEST OUTLOOKS FROM THE STORM PREDICATION CENTER. FOR THE AFTERNOON...IT WILL BECOME NOTICEABLY BREEZIER IN MANY SPOTS...OVERCAST WITH A CHANCE OF SHOWERS AS LOW LEVEL MOISTURE INCREASES. PWAT VALUES LOOK TO RAMP UP TO AN INCH BY THE END OF THE DAY...WHICH WOULD MAKE IT ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL. FORCING WILL REMAIN WEAK TODAY. HIGH TEMPERATURES TODAY WILL BE SIMILAR TO YESTERDAY/S...GENERALLY IN THE 55 TO 60 RANGE...WELL ABOVE NORMAL. THE COLD WILL APPROACH WESTERN NEW YORK THIS EVENING. IT WILL HAVE RUN OUT OF DAYLIGHT AND REALLY ANY GOOD SURFACE INSTABILITY. HOWEVER...A STRONG LOW LEVEL JET OF OVER 50 MPH AS LOW AS 2000 FEET OFF THE DECK WILL BE AHEAD OF IT...AND UP TO 75 MPH ABOUT 5,000 FEET UP! WHILE SURFACE INSTABILITY NEVER REALLY IS THERE...IT DOES APPEARS THAT THE SHOWALTER INDEX (INSTABILITY FROM THE 850 MB LEVEL) WILL GO TO ZERO OR EVEN -1 TO -2 ACROSS PORTIONS OF OUR REGION...JUST AHEAD OF IT OVERNIGHT. THE STORM PREDICTION CENTER HAS NOW PLACED A SLIGHT RISK OVER OUR ENTIRE REGION...NAMELY FOR TONIGHT. AT THIS POINT WE FEEL ANY CONVECTION WOULD BE LOW TOPPED...SCATTERED AT BEST AND CONFINED TO NEAR THE ACTUAL PASSAGE OF THE COLD FRONT. HOWEVER...IT COULD EASILY TAP INTO THE VERY POWERFUL WIND FIELD WHICH COULD TRANSLATE TO WIND GUSTS OVER 50 MPH! IT IS A GOOD BET THAT A CONVECTIVE LINE (PERHAPS WITHOUT ANY CLOUD TO GROUND LIGHTNING STRIKES) WILL DEVELOP AHEAD OF THIS COLD FRONT AND MOVE QUICKLY THROUGH OUR REGION OVERNIGHT. AGAIN THIS LINE COULD BRING GUSTY WINDS TO ABOUT 50 MPH OR MORE. WE HAVE INCLUDED THE CHANCE OF THUNDERSTORMS WITH THE FRONT...SOME OF WHICH MIGHT CONTAIN GUSTY WINDS. WITH THE HIGH PWATS AND STRONG CONVERGENCE WITH THE FRONT...RAIN COULD BE HEAVY AT TIMES WITH THE LINE. WE DID NOT PUT ANY AREA IN A HIGH WIND WATCH. IT LOOKS TO US AS MUCH OF THE TIME THE GRADIENT OVERNIGHT WILL BE BELOW WIND ADVISORY THRESHOLDS DUE TO AN INVERSION OVERHEAD (UNTIL THE COLD FRONT ARRIVES). ONE EXCEPTION COULD THE ADIRONDACKS WHICH COULD SEE WIND GUSTS EXCEEDING 40 MPH. HOWEVER...WE WERE NOT CONFIDENT JUST YET IN PLACING THEM INTO A HIGH WIND WATCH. LATER CREWS MIGHT BE ISSUING ONE LATER ON TODAY. THE BETTER CHANCE FOR ANY DAMAGING WINDS WOULD BE ALONG THE SQUALL LINE SHOULD IT FORM. OVERNIGHT LOWS WILL REMAIN EXCEPTIONALLY MILD FOR THE TIME OF YEAR...FALLING LITTLE IF ANY...REMAINING IN THE 50S IN MOST AREAS. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... MODEL SUITE DURING THIS PERIOD IS VERY MUCH IN AGREEMENT. INTENSE STORM IS VERTICAL AND LIFTING QUICKLY NE ACROSS ONTARIO/QB BORDER REGIONS MONDAY MORNING AS ITS CDFNT HAS CLEARED THE FCA. CLEARING SHOULD BE RAPID ACROSS FCA AS DRY SLOT OVERSPREADS REGION. SFC WIND GRADIENT SHIFTS TO WEST AND REMAINS ABOUT 12MB MON ACROSS NYS. SO BRISK WEST WINDS WITH SOME DOWN SLOPING AND COMPRESSION WILL FOLLOW FROPA WITH A MILD BUT BRISK DAY. TEMPS WILL REMAIN IN THE 50S AND LOW TO MID 60S S&E OF ALB. 2NDRY CDFNT AND A STRONG 500 HPA SHORT WV WILL APPROACH TWRD EVENING WITH CLOUDS INCR FM NW TO SE. MON NT FLOW WILL SHIFT TO NW BEHIND SECONDARY CDFNT...THEN N AS TROF AXIS MOVES ACROSS RGN AND CAA INCR WITH SFC HIGH BUILDING FM OH VLY TO GRTLKS. MODEST LK EFFECT RESPONSE AND UPSLOPE N FLOW OVER HIR TRRN WILL INCR CLOUDS AND RESULT IN -SHSN N AND W MON NT INTO TUE MRNG. THIS ACTIVITY WILL END QUICKLY TUESDAY MORNING AS TROF SHIFTS EAST...UVM FM TROF BCMS DVM...AND SFC FLOW IS MOSTLY N..BUT WINDS WILL STILL BE VERY BRISK TUES. THE PERIOD ENDS WITH TRANQUILITY AS SFC HIGH CENTER SHIFTS OVER RGN WED MORNING...AND RIDGING BUILDS OVER NE USA MIDWEEK. WITH IDEAL RADIATIONAL COOLING...CLEAR SKIES...LIGHT WINDS...14 HOURS OF NIGHT...TEMPS WILL DROP TO SINGLE DIGITS N TO LOW 20S SE. MOS MDL MINS HAVE BEEN TRENDING COLDER FOR THIS PERIOD SINCE LATE LAST WEEK. WED WILL START COLD AND REMAIN CHILLY WITH MAX TEMPS 5-10 DEG BLOW NORMAL. BUT WITH LIGHT WINDS AND LOTS OF SUN WILL BE RELATIVELY PLEASANT FOR MID NOV. WED NT WILL BE ANOTHER COLD ONE UNDER THE SFC HIGH CENTER WITH LOWS 10 TO LOW 20S. && .LONG TERM /THURSDAY THROUGH SATURDAY/... THE PERIOD FEATURES A FAST ZONAL 500HPA FLOW OVER N TIER OF USA...ENDING WITH A BREAKING WAVE AND DEEPENING TROF OVER THE EAST. AS SUCH ITS NOT A HIGH CONFIDENCE EFP AFTER FRIDAY MORNING. MODEL SUITE BEGINS IN AGREEMENT AT FIRST...BUT SPREADS WIDELY BY END OF PERIOD WITH MAINLY TIMING ISSUES BETWEEN ECMWF/GEM AND GFS. THUR 500HPA RIDGE FLATTENS INTO ZONAL FLOW. HVWR SFC HIGH REMAINS ALONG E SEABOARD WITH LT S-SW SFC FLOW. RESULT IS FAIR DAY WITH A SLIGHT MODERATION IN TEMPS TO NR NORMALS. THU NT A WEAK BACKDOOR CDNFT DROPS S ACROSS RGN WITH REINFORCING SHOT OF COLD AIR. HWVR CDFNTS MAGNITUDE AND WIND GRADIENT BEHIND IT OVR RGN FRI VARIES GREATLY FM BTWN THE ECMWF/GEM/GFS AND HPC. ALL THE GUIDS HAS A GENERALLY FAIR BUT COOLER DAY. THE EFP PERIOD ENDS WITH A SERIES OF SHORT WVS DIGGING OUT A TROF AND 500HPA CUT OFF OVER THE EAST. THE GFS PUSHES THIS STRONG CLIPPER TYPE SYSTEM THROUGH REGION FRI NT INTO SAT MORNING...WITH STRONG CAA FOR THE WEEKEND. THE ECMWF/GEM AS FAR AS IT GOES KEEP THE FLOW ZONAL AT 500HPA ...WITH SFC HIGH OVER RGN FRIDAY AND FRI NT. THESE MODELS HAVE THIS STRONG FROPA AND CAA COMING THROUGH A DAY LATER ON SAT NT AND SUN. HPC GUIDANCE IS MORE IN LINE WITH THIS LATER SOLUTION...AND GIVEN LOW CONFIDENCE AT END OF EFP...SEE NO REASON WHY NOT TO GO WITH IT. SO WILL POPULATE WITH HPC ON THIS UPDATE. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... A STRONG COLD FRONT WITH A LIKELY LINE OF SHOWERS AND POSSIBLE WILL IMPACT THE TERMINAL OVERNIGHT. LOW END MVFR AND IFR CONDITIONS HAVE DEVELOPED AS WE DID AMMEND THE TAFS ACCORDINGLY. THESE CIGS WILL LIKELY BOUNCE BETWEEN CATEGORIES FOR THE REMAINDER OF THE DAY ALONG WITH AN INCREASE IN THE LOW LEVEL JET THAT WILL BE ADDRESSED IN FUTURE UPDATES. CIGS LOOK TO LIFT BACK TO THE HIGH END OF MVFR LATER IN THE MORNING AFTER THE MORNING PEAK WITH OVERALL DECENT SURFACE VISIBILITY AS ANY MIST DISSIPATES. HOWEVER...PATCHES OF DRIZZLE COULD DEVELOP DURING THE AFTERNOON (NOT REFLECTED IN THE TAFS) BUT USED VCSH AT THAT TIME. A LIGHT WIND WILL BECOME SOUTH OR SOUTHEAST AROUND 10KTS LATER ON SUNDAY...WITH GUSTS UP TO 20KTS MAINLY AT KALB AND KPSF. AS A STRONG COLD FRONT APPROACHES TO NIGHT...THE SOUTH SURFACE WIND WILL CONTINUE AT 10-15 KTS. STRONGER WINDS ALOFT PROMPTED US TO INCLUDE WIND SHEAR AT THE KGFL TAF AFTER 00Z. AT THIS POINT...IT WILL BE A CLOSE CALL AT THE OTHER TAF SITES BUT DID NOT INCLUDE IT IN JUST YET AS THE DIFFERENTIAL BETWEEN THE SURFACE WIND AND 2000 FEET DID NOT QUITE MEET THE OFFICIAL THRESHOLD...BUT AGAIN IT IS VERY CLOSE AND PILOTS SHOULD LOOK FOR ANY UPDATES. SHOWERS SUNDAY NIGHT COULD REDUCE CONDITIONS TO IFR AT TIMES...ALTHOUGH MVFR LOOKS TO PREDOMINATE. THERE LOOKS TO BE A LINE OF GUSTY SHOWERS (AND POSSIBLY EVEN THUNDERSTORMS) WITH THE COLD FRONT AS IT LOOKS TO CROSS THE TAFS BETWEEN ABOUT 08Z-12Z OVERNIGHT. THE BIGGEST CONCERN COULD BE STRONG GUSTY WINDS ALONG AND JUST BEHIND THIS FEATURE. WE REFLECTED THIS TREND IN THE TAFS. THE EXACT TIMING WILL LIKELY BE ADJUSTED A LITTLE AS THIS LINE APPROACHES AND THE WINDS COULD CERTAINLY BE BRIEFLY STRONGER THAN THE 30KT GUSTS WE ARE CURRENTLY ADVERTISING. OUTLOOK... MONDAY NIGHT AND TUESDAY: LOW OPERATIONAL IMPACT.BREEZY TUESDAY NIGHT THROUGH THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... TODAY WILL BE THE LAST DAY WE ISSUE THE NFDRS FORECASTS AT 300 PM THIS AFTERNOON. TOMORROW MORNING WILL BE LAST ISSUANCE OF THE FIRE WEATHER PRODUCT AND FIRE WEATHER DISCUSSION FOR THIS YEAR. WE WILL CONTINUE TO POPULATE FIRE WEATHER GRIDS TWO TIMES A DAY FOR THE REMAINDER OF THE YEAR. FOR TODAY...HIGH HUMIDITY LEVELS WILL PERSIST ALONG WITH PLENTY OF CLOUDS...SOME PATCHY MORNING DRIZZLE AND THE CHANCE FOR AFTERNOON SHOWERS. A SOUTHERLY WIND WILL INCREASE TO 10 TO 15 MPH BY AFTERNOON. A STRONG COLD FRONT WILL WORK ACROSS THE REGION OVERNIGHT LIKELY BRINGING A SQUALL LINE OF HEAVY SHOWERS AND POSSIBLY SOME EMBEDDED THUNDERSTORMS. MOST PLACES SHOULD RECEIVE A QUARTER INCH OF RAIN OR MORE. WIND GUSTS COULD BRIEFLY REACH 40 MPH OR MORE WITH THIS LINE. MOST PLACES WILL DRY OUT QUICKLY BEHIND THE FRONT...ALTHOUGH SOME SHOWERS COULD LINGER ACROSS MAINLY THE ADIRONDACKS. IT WILL BE SOMEWHAT WINDY WITH SOUTHWEST WIND BECOMING WESTERLY 10 TO 20 MPH WITH A FEW HIGHER GUSTS. DRY AND COLDER WEATHER WILL FOLLOW FOR MUCH OF THE REMAINDER OF THE WORKWEEK. && .HYDROLOGY... NO FLOODING OF RIVERS OR STREAMS ARE EXPECTED OVER THE NEXT FIVE DAYS. HOWEVER...RAIN COULD FALL HEAVILY ENOUGH OVERNIGHT TO PRODUCE AREAS OF PONDING WHERE FALLEN LEAVES MIGHT CLOG DRAINS. TODAY WILL FEATURE SOME PATCHES OF LIGHT DRIZZLE OR RAIN SHOWERS WITH MOST AREAS EXPECTED TO RECEIVE A TENTH OF AN INCH OF RAINFALL OR LESS. A LINE OF SHOWERS AND POSSIBLY EVEN A FEW THUNDERSTORMS WILL WORK ACROSS THE REGION OVERNIGHT...BRINGING MORE SIGNIFICANT RAINFALL. RIGHT NOW WE BELIEVE MOST AREAS WILL HAVE AROUND A HALF INCH OF RAINFALL. THIS WOULD BE ENOUGH TO PRODUCE SOME MINOR RISES ON MANY RIVERS AND STREAMS SINCE VEGETATION IS NOW COMPLETELY DORMANT. HOWEVER...RIVERS AND STREAMS WERE RUNNING A BIT BELOW NORMAL...SO IS VERY UNLIKELY ANY OF THEM WOULD REACH NEAR BANKFULL SINCE IT LOOKS AS IF THE RAIN IS OUT OF HERE FOR THE MOST PART COME MONDAY. A FEW ADDITIONAL LIGHT SHOWERS COULD FALL ACROSS THE ADIRONDACKS THROUGH EARLY TUESDAY...WITH ADDITIONAL AMOUNTS OF RAINFALL UNDER A QUARTER OF AN INCH. LITTLE OR NO ADDITIONAL RESPONSES ARE EXPECTED ON ANY OF THE WATERSHEDS IN OUR REGION. OTHERWISE...WE ARE DRY AGAIN THROUGH MUCH OF THE UPCOMING WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM/SNYDER NEAR TERM...HWJIV/BGM SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...HWJIV/BGM FIRE WEATHER...HWJIV HYDROLOGY...HWJIV FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1108 AM EST SUN NOV 17 2013 ...DENSE SEA FOG OFF THE COAST OF FAR NORTH COASTAL GEORGIA AND FAR SOUTH COASTAL SOUTH CAROLINA... .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE NORTHEAST THROUGH TONIGHT. A STRONG COLD FRONT WILL THEN MOVE THROUGH LATE MONDAY FOLLOWED BY COLDER HIGH PRESSURE BUILDING FROM THE NORTH THROUGH THE MIDDLE OF THE WEEK. ANOTHER COLD FRONT COULD MOVE THROUGH SATURDAY WITH HIGH PRESSURE RETURNING FOR THE END OF NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ISENTROPICALLY INDUCED SHOWER ACTIVITY HAS BEEN DIMINISHING OVER THE PAST TWO HOURS. SHORT TERM GUIDANCE IS NOT OVERLY EXCITED ABOUT THE PROSPECTS FOR MEASURABLE RAINFALL THROUGH EARLY AFTERNOON ANYWHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA...HOWEVER RAP ISENTROPIC FIELDS SHOW MODEST 295-305K ISENTROPIC ASSENT GOING THROUGH THE DAY. WILL LOWER POPS OUT OF THE LIKELY CATEGORY INTO THE MID-RANGE CHANCE CATEGORY ACROSS THE SOUTH BASED ON CURRENT RADAR DATA. THERE ARE SOME SIGNALS THAT A LOOSELY CONCENTRATED AREA OF SHOWERS COULD BRUSH THE CHARLESTON METRO AREA BY EARLY AFTERNOON...BUT AGAIN...MODELS ARE NOT OVERLY IMPRESSED. WILL SHOW 30-40 PERCENT POPS AREA WIDE TODAY...WITH INCREASING POPS ACROSS THE NORTH AS MORE ORGANIZED SHOWER ACTIVITY ATTEMPTS TO APPROACH THE SOUTH CAROLINA ZONES LATER THIS AFTERNOON AS SHORTWAVE ENERGY APPROACHES. EXTENSIVE CLOUD COVER WILL LIMIT HIGHS SOMEWHAT TODAY...ALTHOUGH PRE-FRONTAL COMPRESSIONAL HEATING AND ONGOING WARM AIR ADVECTION COULD COUNTERACT THE LACK OF STRONG INSOLATION. WILL MAINTAIN HIGHS IN THE MID 70S FOR NOW. THE REMAINDER OF THE FORECAST IS ON TRACK. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... TONIGHT...A SOUTH-SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT FROM THE NORTHWEST WILL KEEP DEEP LAYERED MOISTURE IN PLACE ACROSS THE REGION. PRE-FRONTAL SHOWERS ARE EXPECTED TO OCCUR AND THE FORECAST SHOWS A CHANCE OF SHOWERS FOR THE ENTIRE FORECAST AREA. HAVE REMOVED THE MENTION OF THUNDERSTORMS DUE TO LIMITED INSTABILITY BECAUSE OF NOCTURNAL COOLING. IT SHOULD BE A RELATIVELY WARM NIGHT GIVEN THE SOUTH-SOUTHWEST FLOW AND EXTENSIVE CLOUD COVER...WITH LOWS FORECAST IN THE MID 60S IN MOST AREAS. MONDAY THROUGH WEDNESDAY...A COLD FRONT IS SLATED TO APPROACH FROM THE WEST MONDAY MORNING AND THEN SLOWLY PUSH TOWARD THE COAST DURING THE AFTERNOON...ALTHOUGH THERE IS STILL SOME UNCERTAINTY REGARDING THE TIMING OF THIS FEATURE. OVERALL WE THINK THE BEST RAIN CHANCES WILL COME IN THE MORNING WHEN THE DEEPEST MOISTURE WILL BE IN PLACE...BUT THE NAM12 RE-FIRES SOME CONVECTION IN THE AFTERNOON ALONG AND AHEAD OF A SLOWER-MOVING FRONT AS TEMPERATURES WARM TO NEAR 80 DEGREES. THUS...WOULD NOT BE SURPRISED TO SEE A FEW GUSTY THUNDERSTORMS DURING THE AFTERNOON IF THE FRONT IS INDEED SLOWER TO PASS THROUGH. MUCH DRIER AND COOLER AIR WILL PUSH IN FROM THE NORTH MONDAY NIGHT BEHIND THE FRONT...CONTINUING THROUGH WEDNESDAY. THIS WILL LEAD TO BREEZY NORTH/NORTHEAST WINDS TUESDAY AND WEDNESDAY...ESPECIALLY ALONG THE COAST. LAKE WINDS...SMALL RISK FOR LOW-END ADVISORY CONDITIONS DEVELOPING ON LAKE MOULTRIE LATE MONDAY NIGHT INTO EARLY TUESDAY AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... COOL/DRY HIGH PRESSURE WILL PERSIST NORTH OF THE AREA THROUGH THE MIDDLE OF THE WEEK BEFORE BREAKING DOWN LATE IN THE WEEK AS A COLD FRONT APPROACHES. THERE IS NOW MUCH BETTER AGREEMENT BETWEEN THE GFS AND ECMWF SHOWING THE FRONT PUSHING THROUGH SATURDAY WITH COOLER/DRIER HIGH PRESSURE BUILDING BACK IN FOR THE END OF THE WEEKEND. OTHERWISE...IT WILL BE BREEZY THROUGH MID WEEK DUE TO THE TIGHT PRESSURE GRADIENT...WITH HIGHEST WINDS CLOSER TO THE COAST. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... GIVEN EXPANSIVE MID AND UPPER LEVELS CLOUDS...THE THREAT FOR FOG HAS ENDED AT THE TERMINALS THIS MORNING. KCHS...VFR CONDITIONS ARE EXPECTED TO PREVAIL TODAY...ALTHOUGH THERE IS THE POTENTIAL FOR CEILINGS TO DROP TO MVFR LEVELS AT TIMES. SCATTERED SHOWERS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND PERSIST INTO EARLY THIS EVENING AS A DISTURBANCE CROSSES THE REGION...THUS HAVE INCLUDED VICINITY SHOWERS IN THE TAF/S FROM 18-02Z. MODELS ARE IN FAIRLY GOOD AGREEMENT INDICATING THE POTENTIAL FOR IFR CEILINGS AND MVFR VISIBILITIES FROM ABOUT 02Z THROUGH THE END OF THE FORECAST PERIOD AT 12Z MONDAY. KSAV...STRATUS ACROSS SOUTHERN GEORGIA WILL LIFT NORTHWARD THIS MORNING AND IS EXPECTED TO IMPACT THE TERMINAL FROM ABOUT 14-18Z. DURING THIS TIME...THE TAF INDICATES PREVAILING MVFR CEILINGS WITH TEMPORARY IFR CEILINGS FROM 14-16Z. THEN...CEILINGS SHOULD LIFT TO LOW-END VFR LEVELS THROUGH THE REMAINDER OF THE DAY...ALTHOUGH THEY COULD DROP TO MVFR LEVELS AT TIMES. SCATTERED SHOWERS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND PERSIST INTO EARLY THIS EVENING AS A DISTURBANCE CROSSES THE REGION...THUS HAVE INCLUDED VICINITY SHOWERS IN THE TAF/S FROM 18-02Z. MODELS ARE IN FAIRLY GOOD AGREEMENT INDICATING THE POTENTIAL FOR IFR CEILINGS AND MVFR VISIBILITIES FROM ABOUT 02Z THROUGH THE END OF THE FORECAST PERIOD AT 12Z MONDAY. EXTENDED AVIATION OUTLOOK...MVFR...POSSIBLY IFR...CONDITIONS MON ALONG AND AHEAD OF A COLD FRONT. OTHERWISE...MAINLY VFR THROUGH FRIDAY...ALTHOUGH BREEZY/GUSTY CONDITIONS ARE EXPECTED TUESDAY/WEDNESDAY AND POSSIBLY THURSDAY. && .MARINE... TODAY...TYBEE ISLAND WEBCAMS AND REPORTS FROM THE TYBEE ISLAND COAST GUARD INDICATE AN AREA OF DENSE SEA FOG HAS DEVELOPED FROM ROUGHLY HILTON HEAD SOUTH TO SAINT CATHERINES SOUND. ITS UNCLEAR HOW FAR OFFSHORE THE FOG EXTENDS WITH MID-LEVEL CLOUDS BLOCKING VIEWS FROM SATELLITE...BUT HAVE HOISTED A MARINE DENSE FOG ADVISORY FOR THE GEORGIA NEARSHORE WATERS AND THE FAR SOUTHERN SOUTH CAROLINA NEARSHORE WATERS UNTIL 4 PM EST. A COASTAL TROUGH WILL DISSIPATE EAST OF THE WATERS...ALLOWING A RETURN FLOW TO DEVELOP ALONG THE PERIPHERY OF HIGH PRESSURE NORTHEAST OF THE REGION. THIS WILL CAUSE WINDS TO GRADUALLY VEER SOUTHEAST OR SOUTH THROUGH THE DAY. WIND SPEEDS WILL GENERALLY BE AROUND 10 KT OR LESS DUE TO THE LACK ANY SIGNIFICANT PRESSURE GRADIENT. SEAS WILL REMAIN IN THE 2-4 FT RANGE. TONIGHT...A SOUTH-SOUTHWEST FLOW WILL STRENGTHEN TO AS MUCH AS 10-15 KT IN ADVANCE OF AN APPROACHING COLD FRONT FROM THE NORTHWEST. SEAS WILL BUILD BY ABOUT A FOOT OR SO AS A RESULT. PERHAPS THE BIGGEST CONCERN TONIGHT IS FOR THE POTENTIAL FOR SEA FOG TO FORM AS DEWPOINTS SURGE IN THE UPPER 60S ON THE STRENGTHENING SOUTHERLY FLOW. GIVEN CONSIDERABLY COOLER SEA SURFACE TEMPERATURES...THIS WILL RESULT IN CONDITIONS FAVORABLE FOR SEA FOG TO FORM OR ADVECT IN FROM THE SOUTH TONIGHT AND COULD REDUCE VISIBILITIES ENOUGH TO WARRANT A DENSE FOG ADVISORY FOR PORTIONS OF THE NEAR SHORE COASTAL WATERS AND CHARLESTON HARBOR. MONDAY THROUGH FRIDAY...A COLD FRONT WILL PUSH THROUGH LATE MONDAY WITH WINDS/SEAS INCREASING GREATLY MONDAY NIGHT FROM THE NORTH AS STRONG HIGH PRESSURE BUILDS INTO THE OHIO VALLEY. SOLID SMALL CRAFT ADVISORY CONDITIONS ARE ANTICIPATED FOR ALL WATERS INTO THURSDAY WITH THE POTENTIAL FOR GALE FORCE WINDS...MAINLY BEYOND 20 NM FROM SHORE. INCREASING LOW-LEVEL MOISTURE ATOP THE RELATIVELY COOL NEARSHORE WATERS COULD PRODUCE SOME SEA FOG MONDAY UNTIL THE FRONT PUSHES THROUGH. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...DENSE FOG ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ352- 354. && $$ ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
915 AM EST SUN NOV 17 2013 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE NORTHEAST THROUGH TONIGHT. A STRONG COLD FRONT WILL THEN MOVE THROUGH LATE MONDAY FOLLOWED BY COLDER HIGH PRESSURE BUILDING FROM THE NORTH THROUGH THE MIDDLE OF THE WEEK. ANOTHER COLD FRONT COULD MOVE THROUGH SATURDAY WITH HIGH PRESSURE RETURNING FOR THE END OF NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ISENTROPICALLY INDUCED SHOWER ACTIVITY HAS BEEN DIMINISHING OVER LAST FOR THE PAST TWO HOURS. SHORT TERM GUIDANCE IS NOT OVERLY EXCITED ABOUT THE PROSPECTS FOR MEASURABLE RAINFALL THROUGH EARLY AFTERNOON ANYWHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA...HOWEVER RAP ISENTROPIC FIELDS SHOW MODEST 295-305K ISENTROPIC ASSENT GOING THROUGH THE DAY. WILL LOWER POPS OUT OF THE LIKELY CATEGORY INTO THE MID-RANGE CHANCE CATEGORY ACROSS THE SOUTH BASED ON CURRENT RADAR DATA. THERE ARE SOME SIGNALS THAT A LOOSELY CONCENTRATED AREA OF SHOWERS COULD BRUSH THE CHARLESTON METRO AREA BY EARLY AFTERNOON...BUT AGAIN...MODELS ARE NOT OVERLY IMPRESSED. WILL SHOW 30-40 PERCENT POPS AREA WIDE TODAY...WITH INCREASING POPS ACROSS THE NORTH AS MORE ORGANIZED SHOWER ACTIVITY ATTEMPTS TO APPROACH THE SOUTH CAROLINA ZONES LATER THIS AFTERNOON AS SHORTWAVE ENERGY APPROACHES. EXTENSIVE CLOUD COVER WILL LIMIT HIGHS SOMEWHAT TODAY...ALTHOUGH PRE-FRONTAL COMPRESSIONAL HEATING AND ONGOING WARM AIR ADVECTION COULD COUNTERACT THE LACK OF STRONG INSOLATION. WILL MAINTAIN HIGHS IN THE MID 70S FOR NOW. THE REMAINDER OF THE FORECAST IS ON TRACK. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... TONIGHT...A SOUTH-SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT FROM THE NORTHWEST WILL KEEP DEEP LAYERED MOISTURE IN PLACE ACROSS THE REGION. PRE-FRONTAL SHOWERS ARE EXPECTED TO OCCUR AND THE FORECAST SHOWS A CHANCE OF SHOWERS FOR THE ENTIRE FORECAST AREA. HAVE REMOVED THE MENTION OF THUNDERSTORMS DUE TO LIMITED INSTABILITY BECAUSE OF NOCTURNAL COOLING. IT SHOULD BE A RELATIVELY WARM NIGHT GIVEN THE SOUTH-SOUTHWEST FLOW AND EXTENSIVE CLOUD COVER...WITH LOWS FORECAST IN THE MID 60S IN MOST AREAS. MONDAY THROUGH WEDNESDAY...A COLD FRONT IS SLATED TO APPROACH FROM THE WEST MONDAY MORNING AND THEN SLOWLY PUSH TOWARD THE COAST DURING THE AFTERNOON...ALTHOUGH THERE IS STILL SOME UNCERTAINTY REGARDING THE TIMING OF THIS FEATURE. OVERALL WE THINK THE BEST RAIN CHANCES WILL COME IN THE MORNING WHEN THE DEEPEST MOISTURE WILL BE IN PLACE...BUT THE NAM12 RE-FIRES SOME CONVECTION IN THE AFTERNOON ALONG AND AHEAD OF A SLOWER-MOVING FRONT AS TEMPERATURES WARM TO NEAR 80 DEGREES. THUS...WOULD NOT BE SURPRISED TO SEE A FEW GUSTY THUNDERSTORMS DURING THE AFTERNOON IF THE FRONT IS INDEED SLOWER TO PASS THROUGH. MUCH DRIER AND COOLER AIR WILL PUSH IN FROM THE NORTH MONDAY NIGHT BEHIND THE FRONT...CONTINUING THROUGH WEDNESDAY. THIS WILL LEAD TO BREEZY NORTH/NORTHEAST WINDS TUESDAY AND WEDNESDAY...ESPECIALLY ALONG THE COAST. LAKE WINDS...SMALL RISK FOR LOW-END ADVISORY CONDITIONS DEVELOPING ON LAKE MOULTRIE LATE MONDAY NIGHT INTO EARLY TUESDAY AS STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... COOL/DRY HIGH PRESSURE WILL PERSIST NORTH OF THE AREA THROUGH THE MIDDLE OF THE WEEK BEFORE BREAKING DOWN LATE IN THE WEEK AS A COLD FRONT APPROACHES. THERE IS NOW MUCH BETTER AGREEMENT BETWEEN THE GFS AND ECMWF SHOWING THE FRONT PUSHING THROUGH SATURDAY WITH COOLER/DRIER HIGH PRESSURE BUILDING BACK IN FOR THE END OF THE WEEKEND. OTHERWISE...IT WILL BE BREEZY THROUGH MID WEEK DUE TO THE TIGHT PRESSURE GRADIENT...WITH HIGHEST WINDS CLOSER TO THE COAST. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... GIVEN EXPANSIVE MID AND UPPER LEVELS CLOUDS...THE THREAT FOR FOG HAS ENDED AT THE TERMINALS THIS MORNING. KCHS...VFR CONDITIONS ARE EXPECTED TO PREVAIL TODAY...ALTHOUGH THERE IS THE POTENTIAL FOR CEILINGS TO DROP TO MVFR LEVELS AT TIMES. SCATTERED SHOWERS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND PERSIST INTO EARLY THIS EVENING AS A DISTURBANCE CROSSES THE REGION...THUS HAVE INCLUDED VICINITY SHOWERS IN THE TAF/S FROM 18-02Z. MODELS ARE IN FAIRLY GOOD AGREEMENT INDICATING THE POTENTIAL FOR IFR CEILINGS AND MVFR VISIBILITIES FROM ABOUT 02Z THROUGH THE END OF THE FORECAST PERIOD AT 12Z MONDAY. KSAV...STRATUS ACROSS SOUTHERN GEORGIA WILL LIFT NORTHWARD THIS MORNING AND IS EXPECTED TO IMPACT THE TERMINAL FROM ABOUT 14-18Z. DURING THIS TIME...THE TAF INDICATES PREVAILING MVFR CEILINGS WITH TEMPORARY IFR CEILINGS FROM 14-16Z. THEN...CEILINGS SHOULD LIFT TO LOW-END VFR LEVELS THROUGH THE REMAINDER OF THE DAY...ALTHOUGH THEY COULD DROP TO MVFR LEVELS AT TIMES. SCATTERED SHOWERS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND PERSIST INTO EARLY THIS EVENING AS A DISTURBANCE CROSSES THE REGION...THUS HAVE INCLUDED VICINITY SHOWERS IN THE TAF/S FROM 18-02Z. MODELS ARE IN FAIRLY GOOD AGREEMENT INDICATING THE POTENTIAL FOR IFR CEILINGS AND MVFR VISIBILITIES FROM ABOUT 02Z THROUGH THE END OF THE FORECAST PERIOD AT 12Z MONDAY. EXTENDED AVIATION OUTLOOK...MVFR...POSSIBLY IFR...CONDITIONS MON ALONG AND AHEAD OF A COLD FRONT. OTHERWISE...MAINLY VFR THROUGH FRIDAY...ALTHOUGH BREEZY/GUSTY CONDITIONS ARE EXPECTED TUESDAY/WEDNESDAY AND POSSIBLY THURSDAY. && .MARINE... TODAY...A COASTAL TROUGH WILL DISSIPATE EAST OF THE WATERS...ALLOWING A RETURN FLOW TO DEVELOP ALONG THE PERIPHERY OF HIGH PRESSURE NORTHEAST OF THE REGION. THIS WILL CAUSE WINDS TO GRADUALLY VEER SOUTHEAST OR SOUTH THROUGH THE DAY. WIND SPEEDS WILL GENERALLY BE AROUND 10 KT OR LESS DUE TO THE LACK ANY SIGNIFICANT PRESSURE GRADIENT. SEAS WILL REMAIN IN THE 2-4 FT RANGE. TONIGHT...A SOUTH-SOUTHWEST FLOW WILL STRENGTHEN TO AS MUCH AS 10-15 KT IN ADVANCE OF AN APPROACHING COLD FRONT FROM THE NORTHWEST. SEAS WILL BUILD BY ABOUT A FOOT OR SO AS A RESULT. PERHAPS THE BIGGEST CONCERN TONIGHT IS FOR THE POTENTIAL FOR SEA FOG TO FORM AS DEWPOINTS SURGE IN THE UPPER 60S ON THE STRENGTHENING SOUTHERLY FLOW. GIVEN CONSIDERABLY COOLER SEA SURFACE TEMPERATURES...THIS WILL RESULT IN CONDITIONS FAVORABLE FOR SEA FOG TO FORM OR ADVECT IN FROM THE SOUTH TONIGHT AND COULD REDUCE VISIBILITIES ENOUGH TO WARRANT A DENSE FOG ADVISORY FOR PORTIONS OF THE NEAR SHORE COASTAL WATERS AND CHARLESTON HARBOR. MONDAY THROUGH FRIDAY...A COLD FRONT WILL PUSH THROUGH LATE MONDAY WITH WINDS/SEAS INCREASING GREATLY MONDAY NIGHT FROM THE NORTH AS STRONG HIGH PRESSURE BUILDS INTO THE OHIO VALLEY. SOLID SMALL CRAFT ADVISORY CONDITIONS ARE ANTICIPATED FOR ALL WATERS INTO THURSDAY WITH THE POTENTIAL FOR GALE FORCE WINDS...MAINLY BEYOND 20 NM FROM SHORE. INCREASING LOW-LEVEL MOISTURE ATOP THE RELATIVELY COOL NEARSHORE WATERS COULD PRODUCE SOME SEA FOG MONDAY UNTIL THE FRONT PUSHES THROUGH. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
621 AM EST SUN NOV 17 2013 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WILL DIRECT AN ONSHORE FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY. COLD HIGH PRESSURE WILL FOLLOW THE FRONT AND DOMINATE THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... DENSE FOG COVERED MUCH OF THE FORECAST AREA EARLY THIS MORNING. SHALLOW LOW-LEVEL MOISTURE AND LIGHT WIND HELPED CAUSE THE FOG. BASED ON THE HRRR GUIDANCE EXPECT IMPROVING VISIBILITIES BEGINNING AROUND 1000 AM. WE HAVE POSTED A DENSE FOG ADVISORY. MOISTURE WILL BECOME DEEPER LATER TODAY WITH A MOIST SOUTHEAST TO SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH PLUS AN APPROACHING MID-LEVEL SHORTWAVE TROUGH. THE SHOWER CHANCE SHOULD INCREASE DURING THE AFTERNOON. THE GUIDANCE CONSENSUS SUPPORTS POPS OF 40 TO 60 PERCENT. WE LEANED TOWARD THE GFS AND ECMWF MOS FOR THE TEMPERATURE FORECAST. THE NAM MOS MAY BE TOO WARM BECAUSE OF THE MORNING FOG AND SOME CLOUDINESS CONTINUING FOR MUCH OF THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE COLD FRONT WILL CONTINUE TO APPROACH TONIGHT. THE NAM AND GFS INDICATE DEEP MOISTURE WITH PRECIPITABLE WATER INCREASING TO NEAR 1.8 OF AN INCH. USED THE HIGHER POP GUIDANCE. AN AVERAGE OF THE GFS AND NAM PLUS SREF MEAN SUPPORTS TOTAL RAINFALL AROUND ONE- QUARTER OF AN INCH. DESPITE THE HIGH PRECIPITABLE WATER THIS RELATIVELY LIGHT AMOUNT MAY BE CORRECT BECAUSE OF WEAK LIFT. THERE MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS. THE NAM INDICATES A SHOWALTER INDEX AROUND -1 TONIGHT. ITS LOWEST SURFACE-BASED LI IS AROUND ZERO. THE MODEL TREND HAS BEEN DIMINISHING INSTABILITY. THE WEAK INSTABILITY APPEARS REASONABLE BECAUSE MOST OF THE UPPER-LEVEL LIFT SHOULD STAY WELL NORTH OF THE FORECAST AREA. SHEAR WILL BE STRONG WITH H85 WINDS NEAR 30 KNOTS BUT WITH A LACK OF SIGNIFICANT INSTABILITY THE THREAT OF SEVERE THUNDERSTORMS IS LOW. THE NAM AND GFS ARE CONSISTENT SHOWING DRYING BEGINNING BY MIDDAY MONDAY BEHIND THE FRONT. BELIEVE THE WARMER TEMPERATURE GUIDANCE IS BETTER TODAY BECAUSE OF THE WARM AIR MASS AHEAD OF THE FRONT. CLOUDINESS AND MIXING SHOULD HOLD UP TEMPERATURES TONIGHT. THE TEMPERATURE GUIDANCE IS LIKELY TOO COOL. WE WILL GET OFF TO A RELATIVELY WARM START MONDAY AND THE COOLER AIR WILL BE LAGGING BEHIND THE FRONT. IT SHOULD BE ANOTHER VERY WARM DAY. USED THE WARMER TEMPERATURE GUIDANCE. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE MEDIUM-RANGE MODELS ARE IN GOOD AGREEMENT INDICATING DRY RIDGING DOMINATING TUESDAY THROUGH WEDNESDAY. MOISTURE MAY BEGIN TO INCREASE THURSDAY WITH AN ONSHORE FLOW AND THE MOISTURE MAY BE DEEP BY SATURDAY ASSOCIATED WITH A FRONTAL SYSTEM. THE ECMWF WAS SLOWER WITH THE TIMING OF THE FRONT. AN AVERAGE OF THE GFS...ECMWF...AND EKD MOS SUPPORTED CHANCE POPS SATURDAY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... WEAK WEDGE CONTINUES OVER THE AREA EARLY THIS MORNING. CONDITIONS DETERIORATING TO IFR/LIFR LEVELS ACROSS MUCH OF THE AREA. MODELS STILL SUGGESTING IFR/LIFR FOG WILL PERSIST UNTIL AROUND 14Z. COULD SEE SOME VARIABILITY IN CONDITIONS AMONG THE TAF SITES...WITH CLOUDS POSSIBLY KEEPING AGS/DNL AT VFR EARLY THIS MORNING. SHOULD SEE CIG/VSBY IMPROVEMENT TO MVFR OR VFR 15Z-17Z. CHANCE FOR SHOWERS LATER THIS AFTERNOON WILL INCREASE FOR TONIGHT AS A COLD FRONT APPROACHES FROM THE WEST. WILL MENTION MVFR CIGS/VSBYS WITH SHOWERS AFTER 06Z MONDAY...BUT LOWER CONDITIONS MAY BE POSSIBLE AS THE FRONT GETS CLOSER. EXTENDED AVIATION OUTLOOK...RESTRICTIONS CAN BE EXPECTED EARLY MONDAY MORNING AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT IS FORECAST TO CROSS THE AREA BY LATE MONDAY MORNING. BREEZY CONDITIONS POSSIBLE TUESDAY AND WEDNESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
521 AM EST SUN NOV 17 2013 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WILL DIRECT AN ONSHORE FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY. COLD HIGH PRESSURE WILL FOLLOW THE FRONT AND DOMINATE THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... DENSE FOG COVERED MUCH OF THE FORECAST AREA EARLY THIS MORNING. SHALLOW LOW-LEVEL MOISTURE AND LIGHT WIND HELPED CAUSE THE FOG. BASED ON THE HRRR GUIDANCE EXPECT IMPROVING VISIBILITIES BEGINNING AROUND 1000 AM. WE HAVE POSTED A DENSE FOG ADVISORY. MOISTURE WILL BECOME DEEPER LATER TODAY WITH A MOIST SOUTHEAST TO SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH PLUS AN APPROACHING MID-LEVEL SHORTWAVE TROUGH. THE SHOWER CHANCE SHOULD INCREASE DURING THE AFTERNOON. THE GUIDANCE CONSENSUS SUPPORTS POPS OF 40 TO 60 PERCENT. WE LEANED TOWARD THE GFS AND ECMWF MOS FOR THE TEMPERATURE FORECAST. THE NAM MOS MAY BE TOO WARM BECAUSE OF THE MORNING FOG AND SOME CLOUDINESS CONTINUING FOR MUCH OF THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE COLD FRONT WILL CONTINUE TO APPROACH TONIGHT. THE NAM AND GFS INDICATE DEEP MOISTURE WITH PRECIPITABLE WATER INCREASING TO NEAR 1.8 OF AN INCH. USED THE HIGHER POP GUIDANCE. AN AVERAGE OF THE GFS AND NAM PLUS SREF MEAN SUPPORTS TOTAL RAINFALL AROUND ONE- QUARTER OF AN INCH. DESPITE THE HIGH PRECIPITABLE WATER THIS RELATIVELY LIGHT AMOUNT MAY BE CORRECT BECAUSE OF WEAK LIFT. THERE MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS. THE NAM INDICATES A SHOWALTER INDEX AROUND -1 TONIGHT. ITS LOWEST SURFACE-BASED LI IS AROUND ZERO. THE MODEL TREND HAS BEEN DIMINISHING INSTABILITY. THE WEAK INSTABILITY APPEARS REASONABLE BECAUSE MOST OF THE UPPER-LEVEL LIFT SHOULD STAY WELL NORTH OF THE FORECAST AREA. SHEAR WILL BE STRONG WITH H85 WINDS NEAR 30 KNOTS BUT WITH A LACK OF SIGNIFICANT INSTABILITY THE THREAT OF SEVERE THUNDERSTORMS IS LOW. THE NAM AND GFS ARE CONSISTENT SHOWING DRYING BEGINNING BY MIDDAY MONDAY BEHIND THE FRONT. BELIEVE THE WARMER TEMPERATURE GUIDANCE IS BETTER TODAY BECAUSE OF THE WARM AIR MASS AHEAD OF THE FRONT. CLOUDINESS AND MIXING SHOULD HOLD UP TEMPERATURES TONIGHT. THE TEMPERATURE GUIDANCE IS LIKELY TOO COOL. WE WILL GET OFF TO A RELATIVELY WARM START MONDAY AND THE COOLER AIR WILL BE LAGGING BEHIND THE FRONT. IT SHOULD BE ANOTHER VERY WARM DAY. USED THE WARMER TEMPERATURE GUIDANCE. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE MEDIUM-RANGE MODELS ARE IN GOOD AGREEMENT INDICATING DRY RIDGING DOMINATING TUESDAY THROUGH WEDNESDAY. MOISTURE MAY BEGIN TO INCREASE THURSDAY WITH AN ONSHORE FLOW AND THE MOISTURE MAY BE DEEP BY SATURDAY ASSOCIATED WITH A FRONTAL SYSTEM. THE ECMWF WAS SLOWER WITH THE TIMING OF THE FRONT. AN AVERAGE OF THE GFS...ECMWF...AND EKD MOS SUPPORTED CHANCE POPS SATURDAY. && .AVIATION /11Z SUNDAY THROUGH THURSDAY/... WEAK WEDGE CONTINUES OVER THE AREA EARLY THIS MORNING. CONDITIONS DETERIORATING TO IFR/LIFR LEVELS ACROSS MUCH OF THE AREA. MODELS STILL SUGGESTING IFR/LIFR FOG WILL PERSIST UNTIL AROUND 14Z. COULD BE SOME VARIABILITY IN CONDITIONS AMONG THE TAF SITES...WITH CLOUDS POSSIBLY KEEPING AGS/DNL AT VFR EARLY THIS MORNING. WATER VAPOR SATELLITE IMAGE INDICATING HIGH LEVEL MOISTURE STREAMING ACROSS THE REGION. SHOULD SEE CIG/VSBY IMPROVEMENT TO MVFR OR VFR 15Z- 17Z. CHANCE FOR SHOWERS LATER THIS AFTERNOON WILL INCREASE FOR TONIGHT AS A COLD FRONT APPROACHES FROM THE WEST. EXTENDED AVIATION OUTLOOK...MODERATE TO HIGH CONFIDENCE IN RESTRICTIONS LATE SUNDAY NIGHT INTO MONDAY MORNING AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT IS FORECAST TO CROSS THE AREA MONDAY MORNING. BREEZY CONDITIONS POSSIBLE TUESDAY AND WEDNESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
514 AM EST SUN NOV 17 2013 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WILL DIRECT AN ONSHORE FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY. COLD HIGH PRESSURE WILL FOLLOW THE FRONT AND DOMINATE THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... DENSE FOG COVERED MUCH OF THE FORECAST AREA EARLY THIS MORNING. SHALLOW LOW-LEVEL MOISTURE AND LIGHT WIND HELPED CAUSE THE FOG. BASED ON THE HRRR GUIDANCE EXPECT IMPROVING VISIBILITIES BEGINNING AROUND 1000 AM. WE HAVE POSTED A DENSE FOG ADVISORY. MOISTURE WILL BECOME DEEPER LATER TODAY WITH A MOIST SOUTHEAST TO SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH PLUS AN APPROACHING MID-LEVEL SHORTWAVE TROUGH. THE SHOWER CHANCE SHOULD INCREASE DURING THE AFTERNOON. THE GUIDANCE CONSENSUS SUPPORTS POPS OF 40 TO 60 PERCENT. WE LEANED TOWARD THE GFS AND ECMWF MOS FOR THE TEMPERATURE FORECAST. THE NAM MOS MAY BE TOO WARM BECAUSE OF THE MORNING FOG AND SOME CLOUDINESS CONTINUING FOR MUCH OF THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE COLD FRONT WILL CONTINUE TO APPROACH TONIGHT. THE NAM AND GFS INDICATE DEEP MOISTURE WITH PRECIPITABLE WATER INCREASING TO NEAR 1.8 OF AN INCH. USED THE HIGHER POP GUIDANCE. AN AVERAGE OF THE GFS AND NAM PLUS SREF MEAN SUPPORTS TOTAL RAINFALL AROUND ONE- QUARTER OF AN INCH. DESPITE THE HIGH PRECIPITABLE WATER THIS RELATIVELY LIGHT AMOUNT MAY BE CORRECT BECAUSE OF WEAK LIFT. THERE MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS. THE NAM INDICATES A SHOWALTER INDEX AROUND -1 TONIGHT. ITS LOWEST SURFACE-BASED LI IS AROUND ZERO. THE MODEL TREND HAS BEEN DIMINISHING INSTABILITY. THE WEAK INSTABILITY APPEARS REASONABLE BECAUSE MOST OF THE UPPER-LEVEL LIFT SHOULD STAY WELL NORTH OF THE FORECAST AREA. SHEAR WILL BE STRONG WITH H85 WINDS NEAR 30 KNOTS BUT WITH A LACK OF SIGNIFICANT INSTABILITY THE THREAT OF SEVERE THUNDERSTORMS IS LOW. THE NAM AND GFS ARE CONSISTENT SHOWING DRYING BEGINNING BY MIDDAY MONDAY BEHIND THE FRONT. BELIEVE THE WARMER TEMPERATURE GUIDANCE IS BETTER TODAY BECAUSE OF THE WARM AIR MASS AHEAD OF THE FRONT. CLOUDINESS AND MIXING SHOULD HOLD UP TEMPERATURES TONIGHT. THE TEMPERATURE GUIDANCE IS LIKELY TOO COOL. WE WILL GET OFF TO A RELATIVELY WARM START MONDAY AND THE COOLER AIR WILL BE LAGGING BEHIND THE FRONT. IT SHOULD BE ANOTHER VERY WARM DAY. USED THE WARMER TEMPERATURE GUIDANCE. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE MEDIUM-RANGE MODELS ARE IN GOOD AGREEMENT INDICATING DRY RIDGING DOMINATING TUESDAY THROUGH WEDNESDAY. MOISTURE MAY BEGIN TO INCREASE THURSDAY WITH AN ONSHORE FLOW AND THE MOISTURE MAY BE DEEP BY SATURDAY ASSOCIATED WITH A FRONTAL SYSTEM. THE ECMWF WAS SLOWER WITH THE TIMING OF THE FRONT. AN AVERAGE OF THE GFS...ECMWF...AND EKD MOS SUPPORTED CHANCE POPS SATURDAY. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... WEAK WEDGE CONTINUES OVER THE AREA EARLY THIS MORNING. CONFIDENCE STILL HIGH FOR LIFR/IFR CONDITIONS AT ALL TERMINALS. SHOULD SEE CIG/VSBY IMPROVEMENT TO MVFR OR VFR 16Z-18Z. CHANCE FOR SHOWERS LATER THIS AFTERNOON WILL INCREASE FOR TONIGHT AS A COLD FRONT APPROACHES FROM THE WEST. EXTENDED AVIATION OUTLOOK...MODERATE TO HIGH CONFIDENCE IN RESTRICTIONS SUNDAY NIGHT INTO MONDAY MORNING AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT IS FORECAST TO CROSS THE AREA MONDAY MORNING. BREEZY CONDITIONS POSSIBLE TUESDAY AND WEDNESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS BOISE ID
842 PM MST MON NOV 18 2013 .DISCUSSION...LIGHT RAIN WAS REPORTED IN BURNS OREGON AND RADAR ECHOES INDICATE VIRGA OR POSSIBLY LIGHT PRECIPITATION ACROSS PORTION OF BAKER HARNEY AND MALHEUR COUNTIES IN OREGON TO WESTERN WASHINGTON COUNTY IDAHO...BUT WEB CAMS IN THOSE AREA ARE SO FAR SNOW FREE. HIGHS WERE A BIT COOLER THAN EXPECTED DUE TO THE RAPID INCREASE IN CLOUD COVER TODAY. 8 PM TEMPERATURES IN THE LOWER 30S WERE COMMON ACROSS THE NORTH FROM THE ELKHORNS TO MCCALL SO HAVE LOWERED SNOW LEVELS AND MIN TEMPS SLIGHTLY. THIS RESULTED IN 2 INCHES OF SNOW FALL FOR MCCALL TONIGHT /SEE PFMBOI/. THROUGH WEDNESDAY MORNING THE STORM TOTAL SNOW ACCUMULATION IN THE HIGHER MOUNTAINS ABOVE 6500 FEET COULD REACH A FOOT. THE TREASURE VALLEY /GENERALLY VALE TO MOUNTAIN HOME/ WILL SEE ALL RAIN...AROUND ONE QUARTER OF AN INCH BASIN AVERAGE. REMAINDER OF FORECAST IS ON TRACK WITH ZONES AND GRID UPDATES ALREADY OUT. && .AVIATION...CEILINGS WILL LOWER THROUGH THE NIGHT. LOCAL IFR CONDITIONS IN SNOW ACROSS MTNS OF EAST-CENTRAL OREGON AND WEST-CENTRAL IDAHO TONIGHT THROUGH WEDNESDAY MORNING WITH SNOW AOA 5K FEET MSL. RAIN AND AREAS OF MVFR DEVELOPING IN LOWER VALLEYS THROUGH TUESDAY AFTERNOON. SURFACE WINDS TO 15 KTS WITH WESTERLY WINDS ALOFT TO 35 KTS AT 10K FEET MSL. CONDITIONS WILL GRADUALLY IMPROVE FROM NW TO SE ON WEDNESDAY. && .PREV DISCUSSION... SHORT TERM...TONIGHT THROUGH WEDNESDAY...A VIGOROUS AND FAST- MOVING SERIES OF SYSTEMS IS MOVING EAST TOWARD THE PAC NW. THE INITIAL WAVE IS SET TO MOVE INTO SE OREGON THIS EVENING AND INTO SW IDAHO OVERNIGHT. LATEST GUIDANCE FROM THE 18Z NAM IS SLOWING THE SYSTEM DOWN SIGNIFICANTLY...BUT WILL GO WITH THE OVERWHELMING AGREEMENT OF THE GFS AND EC...ALONG WITH THE 12Z NAM AND THE LATEST HRRR RUNS...ON THE PRECIP AREA GETTING THROUGH THE TREASURE VALLEY BY 12Z. CLOUD COVER WILL BE EXTENSIVE TONIGHT...KEEPING LOW TEMPS WELL ABOVE NORMAL. THE SECOND MAJOR WAVE IN THE SERIES WILL MOVE THROUGH TUE NIGHT INTO WED...BRINGING ANOTHER ROUND OF WIDESPREAD PRECIP. SNOW LEVELS FOR BOTH EVENTS WILL BE TOO HIGH TO BRING SNOW TO THE VALLEYS...WITH HEIGHTS RANGING FROM 5000 FEET IN THE NORTH TO 7500 FEET IN THE SOUTH TONIGHT...AND FROM 5500 FEET IN THE NORTH TO 6500 FEET IN THE SOUTH FOR TUE NIGHT INTO WED MORNING WHEN THE MAJORITY OF THE PRECIP ASSOCIATED WITH THE SECOND SYSTEM WILL FALL. HEIGHTS WILL COME DOWN SWIFTLY THROUGH THE DAY WED...CHANGING THE RAIN TO SNOW IN THE NORTH...BUT BY THAT TIME MOST OF THE PRECIP WILL HAVE ENDED. TEMPS THROUGH THE SHORT TERM WILL HAVE MINIMAL DIURNAL RANGE OWING TO CLOUD COVER. CHANGES FROM THE PREVIOUS FORECAST WERE MINOR. LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...MOSTLY DRY CONDITIONS WEDNESDAY NIGHT AND THURSDAY WITH LINGERING SHOWERS ALONG THE NEVADA BORDER AS A WEATHER SYSTEM EXITS TO THE EAST AND A RIDGE OF HIGH PRESSURE BUILDS OFF THE WEST COAST. DRY CONDITIONS WILL CONTINUE OVER THE FORECAST AREA FRIDAY THROUGH MONDAY. AS THE RIDGE OF HIGH PRESSURE STRENGTHENS OVER THE FORECAST AREA TEMPERATURE INVERSIONS WILL DEVELOP FRIDAY MORNING AND WILL PERSIST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. WITH RESIDUAL MOISTURE FROM THE PRECIPITATION FROM TUESDAY AND WEDNESDAY COMBINED WITH THE INVERSIONS WILL SEE AREAS OF VALLEY FOG AND LOW STRATUS. TEMPERATURES WILL AVERAGE NEAR NORMAL BUT VALLEY LOCATIONS UNDER THE INVERSION WILL LIKELY SEE TEMPERATURES A FEW DEGREES BELOW NORMAL. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && $$ WEATHER.GOV/BOISE DISCUSSION...VM AVIATION.....DG PREV SHORT TERM...SP PREV LONG TERM....JA/WH
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1056 AM CST SUN NOV 17 2013 .MESOSCALE DISCUSSION... 1055 AM CST CONVECTION CONTINUES TO BLOSSOM ACROSS CENTRAL INTO NORTHERN IL WITH THE CWA FULL ENTRENCHED IN THE UNCAPPED WARM SECTOR. CONVECTIVE MODE CONTINUES TO BE QUICKLY DEVELOPING CELLS WITH EMBEDDED ROTATION. WHILE MANY CELLS ARE NOT TRULY DISCRETE THEY ARE MAINTAINING SUPERCELL CHARACTERISTICS. ANTICIPATED THAT MORE TRULY DISCRETE CONVECTION WILL DEVELOP IN THE NEXT 1-2 HOURS INTO THE SOUTHEAST HALF/TWO-THIRDS OF THE FORECAST AREA...WHICH IS WHERE THE RAP IS CONTINUING TO KEEP 0-1KM SHEAR AT 35-45 KT. THE POTENTIAL FOR TORNADOES...SOME SIGNIFICANT...LOOKS TO BE RAPIDLY INCREASING THERE. THE CHICAGO AREA IS INCLUDED IN THIS. ALREADY SEEING SOME OF THESE DISCRETE CELLS IN THE ILX CWA. MOVEMENT WILL BE RAPIDLY TO THE NORTHEAST. THE CHICAGO AREA STILL LOOKS TO BE IMPACTED PRIMARILY BETWEEN 12PM- 3PM. FURTHER NORTH AND WEST TOWARD ROCKFORD THE SEVERE WEATHER THREAT REMAINS HIGH EVEN WITH DIMINISHING LOW-LEVEL SHEAR...WITH PRIMARY THREATS WINDS AND TORNADOES. MTF && .DISCUSSION... 304 AM CST HIGH SEVERE WEATHER POTENTIAL ACROSS MUCH OF THE AREA TODAY WITH TORNADOES AND DAMAGING STRAIGHT LINE WINDS A SIGNIFICANT THREAT. SYNOPSIS...NEAR TERM FOCUS CONTINUES TO BE SEVERE WEATHER THREAT AS A MAJOR FALL STORM SYSTEM TAKES SHAPE AND MOVES ACROSS THE REGION. WATER VAPOR IMAGERY SHOWS A BROAD UPPER TROUGH PIVOTING ACROSS THE MID SECTION OF THE COUNTRY WITH EVENING UPPER AIR ANALYSIS SHOWING A 150 KT UPPER JET DIGGING DOWN ITS WESTERN FLANK. AT THE SAME TIME A SUB TROPICAL JET OF AROUND 120 KT IS STRETCHED FROM OKLAHOMA UP THE OHIO VALLEY. SEVERAL SHORTWAVES ARE EMBEDDED IN THE SOUTHWESTERLY FLOW AHEAD OF THE TROUGH WI ONE WAVE CROSSING NORTHWEST ILLINOIS EARLY THIS MORNING AND A HINT OF ANOTHER ACROSS EASTERN KANSAS. AT THE SURFACE...ONE AREA OF LOW PRESSURE IS STRETCHED FROM NORTHERN MINNESOTA ACROSS LAKE SUPERIOR WITH ANOTHER LOW MOVING NORTHEAST FROM CENTRAL KANSAS. SYNOPTICALLY...THE UPPER TROUGH WILL AMPLIFY AS THE UPPER JET ROUNDS THE BASE WITH IT TAKING ON A NEGATIVE TILT AS IT PIVOTS ACROSS THE LOCAL AREA THROUGH THE AFTERNOON. THIS WILL CAUSE THE SURFACE LOW OVER KANSAS TO CONTINUE NORTHEAST REACHING SOUTHERN WISCONSIN BY EARLY AFTERNOON. THE LOW WILL THEN DEEPEN AS THE UPPER TROUGH AMPLIFIES AND CATCHES UP WITH IT ACROSS NORTHERN LAKE MICHIGAN LATE THIS AFTERNOON. A COLD FRONTAL BOUNDARY WILL CROSS THE AREA DURING THE AFTERNOON. DETAILS FOR TODAY...CONVECTION CONTINUES TO WORK NORTHWARD ACROSS THE NORTHWEST HALF OR SO OF THE AREA EARLY THIS MORNING IN CONJUNCTION WITH THE AFOREMENTIONED SHORTWAVE. THIS WAVE IS COINCIDENT WITH A TIGHTENING LOW/MID LEVEL BAROCLINIC ZONE/WARM FRONT THAT IS LIFTING NORTHWARD. STEADY ASCENT WILL CONTINUE OVER THIS BOUNDARY WHICH WILL PROGRESS NORTHWARD THROUGH DAYBREAK KEEPING AT LEAST SCATTERED CONVECTIVE DEVELOPMENT POSSIBLE ACROSS THE NORTHERN CWA BEFORE LIFTING NORTH. HAVE NOT SEEN MUCH IN THE WAY OF WIND GUSTS WITH THE PRECIP THUS FAR WITH INTENSITY HAVING WANED INTO THE OVERNIGHT HOURS...BUT SOME PULSEY CORES ARE POSSIBLE WITH SOME SMALL HAIL. SATELLITE IMAGERY SHOWS A FAIR AMOUNT OF SCT-BKN SKIES UPSTREAM OF THE AREA WITH A MORE WIDESPREAD AREA OF CLOUDS WORKING NORTHWARD TO THE WEST OF THE CWA. SUSPECT THAT THERE WILL BE BREAKS IN THE CLOUDS ACROSS PORTIONS OF THE CWA THIS MORNING. ATTENTION TURNS TO SEVERE POTENTIAL THROUGH THE REST OF THE DAY AS THE ABOVE SYNOPTIC EVOLUTION COMMENCES. BOTH DYNAMIC AND THERMODYNAMIC ASPECTS OF THE SYSTEM ARE IMPRESSIVE AND WILL COME TOGETHER TO PRODUCE AN OUTBREAK OF SEVERE WEATHER ACROSS THE REGION. THE MAIN QUESTION FOR THE LOCAL AREA WILL BE THE AMOUNT OF COVERAGE AS THE SYSTEM WORKS THROUGH INTO THE LATE AFTERNOON. THE WESTERN UPPER JET WILL ROUND THE BASE OF THE TROUGH AND NOSE INTO THE AREA FROM THE SOUTHWEST DURING THE LATE MORNING AND EARLY AFTERNOON. THIS JET WILL ALSO COUPLE WITH THE SUB-TROPICAL JET ALREADY IN PLACE ACROSS THE OHIO VALLEY. IN ADDITION...A 85-90 KT MID LEVEL SPEED MAX WILL NOSE IN UNDERNEATH THE UPPER JET DURING THIS TIME AS WELL. THE COMBINATION OF THESE FEATURES AND THE DEEPENING SURFACE TROUGH WILL PROVIDE DEEP LAYER SHEAR VALUES OF 55-60 KT ACROSS MUCH OF THE AREA BY MIDDAY...WITH AN INCREASE TO NEAR 70 KT ACROSS THE SOUTHEASTERN CWA THIS AFTERNOON...WITH 0-1KM SHEAR VALUES OF AROUND 40 KT. UNSEASONABLY STRONG INSTABILITY WILL DEVELOP AS DEW POINTS RISE INTO THE LOWER 60S WITH CAPE VALUES OF AROUND 1000 J/KG. FORECAST SOUNDINGS SHOW HIGH VALUES OF LOW LEVEL CAPE WITH 150 TO EVEN 200 J/KG IN THE LOWEST 3 KM. ALL OF THIS RESULTS IN IMPRESSIVE VALUES FOR VARIOUS SEVERE WEATHER PARAMETERS. BASED ON ALL OF THIS EXPECT THAT STORMS WILL INITIATE BY LATE MORNING OVER OR JUST SOUTHWEST/WEST OF THE SOUTHWEST CWA AS THE ABOVE SYNOPTIC FEATURES ADVANCE NORTHEAST. COVERAGE OF STORMS LOOKS TO TAKE OFF EARLY THIS AFTERNOON AS THE COUPLING OF THE MID/UPPER JETS MAXIMIZES AND CONTINUES THROUGH THE AFTERNOON. THE SEVERE THREAT WILL MARKEDLY INCREASE AS THIS OCCURS AS WELL. THE RATE AT WHICH COVERAGE INCREASES IS STILL SOMEWHAT UNCERTAIN...AT LEAST THROUGH MIDDAY...WITH IT POSSIBLE THAT A FEW STORMS DEVELOP INITIALLY WITH A MORE RAPID INCREASE HOLDING OFF UNTIL EARLY AFTERNOON WITH THE ARRIVAL OF BETTER FORCING. THE MYRIAD OF AVAILABLE CONVECTIVE ALLOWING GUIDANCE RUNS THE GAMUT OF COVERAGE SCENARIOS. THE LATEST SPC DAY 1 OUTLOOK LINES UP WELL WITH LOCAL THINKING PLACING THE HIGHEST RISK FROM BASICALLY CHICAGO SOUTH TO FORD COUNTY AND POINTS EAST. THIS AREA WILL LINE UP WELL WITH THE BEST FORCING PARAMETERS AND TIMING OF INCREASING COVERAGE THIS AFTERNOON. THE REMAINDER OF THE CWA TO THE WEST INCLUDING THE ROCKFORD AREA IS IN A MODERATE RISK AND MAY BE MORE IN LINE WITH THE INITIAL DEVELOPMENT. AS FAR AS THREATS...THE STRONG SHEAR AND INSTABILITY WILL POINT TO DISCRETE SUPERCELL DEVELOPMENT WITH AN EVENTUAL EVOLUTION INTO A SQUALL LINE LATER TODAY. IT IS POSSIBLE THAT MUCH OF THE ACTIVITY REMAINS FAIRLY DISCRETE ACROSS THE CWA WITH EVOLUTION INTO A PREDOMINATELY LINEAR STRUCTURE TAKING PLACE OVER OR JUST EAST OF THE EASTERN CWA. GIVEN THE STRONG LOW LEVEL SHEAR AND INSTABILITY...TORNADOES ARE A DEFINITE THREAT ALONG WITH DAMAGING WINDS FOLLOWED BY LARGE HAIL. THE STRONG SHEAR AND POTENTIAL FOR MAINTENANCE OF DISCRETE CELLS SUGGEST THE POTENTIAL FOR STRONGER AND LONGER TRACKED TORNADOES SHOULD THEY OCCUR. THE OTHER HIGHLIGHT IS THE SYNOPTIC NON-THUNDERSTORM WINDS. SOUTHERLY SPEEDS WILL INCREASE THROUGH THE MORNING...ESPECIALLY IF ANY MEANINGFUL CLEARING CAN OCCUR AS PRESSURE FALLS INCREASE AHEAD OF THE LOW. THE BIGGEST CONCERN HOWEVER IS WINDS BEHIND THE COLD FRONT WHICH WILL CROSS THE AREA LATER THIS AFTERNOON. THE STRONG GRADIENT AND ASSOCIATED PRESSURE RISES ARE EXPECTED TO ALLOW FOR STRONG MIXING AND GENERATION OF WIND GUSTS THAT COULD TOP 50 KT ACROSS MUCH OF THE CWA...ESPECIALLY FROM THE NORTHERN CHICAGO SUBURBS BACK TOWARDS THE MENDOTA AREA AND POINTS SOUTH. HAVE UPGRADED THIS PORTION OF THE WIND ADVISORY TO A HIGH WIND WARNING THIS AFTERNOON STARTING TOWARD MIDDAY...WITH THE HIGHEST WINDS...OUTSIDE OF STORMS...THIS AFTERNOON. MDB TONIGHT THROUGH SATURDAY... LOW PRESSURE WILL QUICKLY BE LIFTING ACROSS THE NORTHERN LAKES THIS EVENING AND INTO WESTERN QUEBEC MONDAY MORNING...WHILE STILL DEEPENING WHILE HIGH PRESSURE STRENGTHENS ACROSS THE PLAINS TONIGHT AND CONTINUES TO STRENGTHEN AS IT MOVES ACROSS THE OHIO VALLEY AND SOUTHERN LAKES REGION MONDAY NIGHT. THE STRONGEST WINDS/GUSTS SHOULD DIMINISH QUICKLY EARLY THIS EVENING BUT IT WILL REMAIN WINDY THROUGH THE EARLY MORNING HOURS...GRADUALLY DIMINISHING OVERNIGHT. WRAP AROUND SHOWERS WILL BE POSSIBLE FOR A FEW HOURS THIS EVENING...MAINLY ACROSS FAR NORTHERN IL...THEN SHOULD SEE CLEARING SKIES. MUCH COLDER AIR WILL SPREAD ACROSS THE REGION WITH LOWS IN THE MID/UPPER 30S BUT COMBINED WITH THE GUSTY WESTERLY WINDS...WIND CHILLS WILL RANGE FROM THE MID 20S TO AROUND 30 RANGE BY MORNING. MONDAY WILL REMAIN BREEZY WITH HIGHS IN THE LOWER/MID 40S WITH MAINLY SUNNY SKIES. WINDS SHOULD STEADILY DIMINISH FROM MID AFTERNOON THROUGH SUNSET AS THE HIGH CONTINUES TO BUILD EAST. LIGHT WINDS AND GENERALLY CLEAR SKIES SHOULD ALLOW FOR A FAST TEMP DROP MONDAY EVENING WITH THE USUAL COLD SPOTS PERHAPS AS LOW AS THE LOWER 20S...BUT WITH WEAK WARM AIR ADVECTION OVERNIGHT...TEMPS MAY LEVEL OFF AT SOME POINT. SOUTHERLY FLOW RETURNS TUESDAY AND WITH MOSTLY SUNNY SKIES EXPECTED...HIGHS INTO THE UPPER 40S LOOK REASONABLE WITH GUIDANCE SUGGESTING LOWER 50S COULD BE REACHED THUS TEMPS COULD BE SLIGHTLY WARMER. RETURN MOISTURE COMBINED WITH WEAK WAVES LIFTING ACROSS THE AREA NOW APPEAR SUFFICIENT TO PRODUCE SOME SHOWERS WEDNESDAY INTO WEDNESDAY NIGHT. THE MODELS ARE IN MUCH BETTER AGREEMENT WITH THIS SOLUTION BUT STILL SOME TIMING DIFFERENCES AS THE ECMWF HOLDS OFF PRECIP UNTIL WEDNESDAY NIGHT FOR MUCH OF THE AREA AND A SLOWER TIMING COULD MEAN WARMER TEMPS ON WEDNESDAY. A COLD FRONT THEN SAGS SOUTH INTO THE AREA THURSDAY AHEAD OF ANOTHER VERY STRONG HIGH BUILDING SOUTH INTO THE NORTHERN PLAINS. AS THE UPPER TROUGH DIGS ACROSS THE LAKES REGION...ANOTHER WAVE MOVES EAST/NORTHEAST ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. TIMING OF COLDER AIR ALONG WITH END TIME OF PRECIP ALL REMAIN UNCERTAIN FROM THIS DISTANCE. CURRENT TRENDS WOULD SUGGEST A COLD RAIN WITH A BRIEF MIX BEFORE ENDING. HOWEVER...GIVEN THE DIFFERENCES...ITS DIFFICULT TO LOWER OR RAISE POPS FOR VARIOUS TIME PERIODS. THUS HAVE CHANCE POPS FOR THE ENTIRE WEDNESDAY NIGHT THROUGH FRIDAY NIGHT TIME PERIOD AND THERE WILL LIKELY BE PERIODS OF NO PRECIP DURING THIS TIME. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * SOUTH SOUTHWEST WINDS 20-31 KT INCREASING TO 22-35 KT EARLY AFTERNOON. THEN SOUTHWEST WINDS 30-50 KT MID AFTERNOON THROUGH EARLY EVENING. WEST WINDS 20-35 KT OVERNIGHT. * ISOLATED SHOWERS LATE THIS MORNING. A PERIOD OF STRONG TO SEVERE THUNDERSTORMS POSSIBLE MID DAY TO MID AFTERNOON. * MVFR CIGS THROUGH MID AFTERNOON. BRIEFLY IFR CIG/VSBY IN HEAVIER SHOWERS AND THUNDERSTORMS. RODRIGUEZ //DISCUSSION...UPDATED 12Z... ...HIGH WINDS ESPECIALLY MID AFTERNOON TO EARLY EVENING... ...MDT TO HIGH RISK OF SEVERE STORMS LATE MORNING-MID AFTERNOON... SYNOPSIS AND THUNDERSTORM THREAT...NOT A GOOD DAY FOR FLYING. LOW PRESSURE NEAR THE IA/MO BORDER THIS MORNING WILL INTENSIFY AS IT MOVES INTO SOUTH CENTRAL WISCONSIN BY MIDDAY...WITH A STRONG COLD FRONT SURGING EAST ACROSS NORTHERN IL. THE LOW WILL THEN RAPIDLY DEEPEN LATE THIS AFTERNOON AND EARLY THIS EVENING AS IT MOVES ACROSS NORTHERN LAKE MICHIGAN AND THE COLD FRONT SWEEPS INTO INDIANA. UNSEASONABLY MILD AND HUMID AIR IS SURGING NORTH AHEAD OF THE LOW...PRODUCING AREAS OF SHOWERS AND A FEW THUNDERSTORMS THIS MORNING. AS THE LOW INTENSIFIES AND THE ATMOSPHERE DESTABILIZES...MORE ORGANIZED THUNDERSTORM CLUSTERS WILL DEVELOP AHEAD OF THE COLD FRONT OVER CENTRAL ILLINOIS AND MOVE RAPIDLY NORTHEAST. SOME OF THE STORMS WILL PRODUCE DAMAGING WINDS AND EVEN TORNADOES. THUNDERSTORMS WILL END WITH THE PASSAGE OF THE STRONG COLD FRONT. WINDS...SOUTH WINDS ARE IN A LULL EARLY THIS MORNING BUT WILL RAMP UP TO 20 TO 30 KTS BY LATE MORNING. BEHIND THE COLD FRONT VERY STRONG PRESSURE RISES WILL PRODUCED SUSTAINED SOUTHWEST WINDS 25 TO 30 KT WITH GUSTS TO AROUND 50 KT. THE STRONGEST WINDS WILL BE MID AFTERNOON THROUGH EARLY EVENING. WINDS WILL TURN WEST AND GRADUALLY DIMINISH OVERNIGHT. CIG/VSBY...LOOKING AT SURFACE OBS AROUND THE AREA THIS MORNING...CIGS ARE GENERALLY 1000-2000 FT BUT WILL DROP BRIEFLY TO IFR ESPECIALLY IN HEAVIER SHOWERS AND THUNDERSTORMS. CIG/VSBY WILL IMPROVE RAPIDLY AFTER THE COLD FRONTAL PASSAGE THIS EVENING...AND SKIES WILL CLEAR OVERNIGHT. ALLSOPP //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST. * MEDIUM CONFIDENCE IN CIG/VSBY TRENDS. * MEDIUM HIGH CONFIDENCE IN TIMING OF PERIOD OF STRONG STORMS. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR. STRONG WEST WINDS. TUESDAY...VFR. WEDNESDAY AND THURSDAY...CHC SHRA. MVFR POSSIBLE. FRIDAY...CHC RASN. MVFR LIKELY. IFR POSSIBLE. SATURDAY...VFR. ALLSOPP && .MARINE... 142 AM CST ...STORM WARNING ISSUED FOR SOUTH 2/3 OF LAKE MI LATE AFTERNOON AND TONIGHT... POWERHOUSE STORM WILL INTENSIFY RAPIDLY THIS AFTERNOON AND TONIGHT AS IT MOVES FROM NORTHERN ILLINOIS TO SOUTHERN ONTARIO. THERE WILL BE A BIT OF A LULL IN THE WINDS THIS MORNING...AND WINDS WILL BE JUST BELOW GALE FORCE FOR A BIT BUT WILL MAINTAIN THE GALE THROUGH MID AFTERNOON. AS THE LOW PRESSURE MOVES ACROSS THE NORTH END OF THE LAKE THIS AFTERNOON A STRONG COLD FRONT WILL SWEEP RAPIDLY ACROSS THE LAKE. A LARGE PRESSURE FALL/RISE COUPLET WILL MOVE ACROSS NORTHERN IL THIS AFTERNOON AND OVER CENTRAL AND SOUTHERN LAKE MICHIGAN THIS EVENING. EXPECT WINDS TO INTENSIFY LATE AFTERNOON AND EVENING WITH GUSTS OF 50 TO 60 KTS. NORTH PART OF THE LAKE MAY SEE SOME NEAR STORM FORCE GUSTS LATE EVENING THROUGH THE OVERNIGHT HOURS...BUT NOT AS STRONG AS THE SOUTH AND CENTRAL. SO HAVE MAINTAINED THE GALE FOR THE NORTH. GALES WILL THEN CONTINUE OVER THE ENTIRE LAKE THROUGH MONDAY AFTERNOON. FOR THE NEARSHORE...WINDS WILL RAMP UP TO STORM FORCE GUSTS BY LATE AFTERNOON BUT DROP BACK TO GALES THIS EVENING...SO A SHORTER PERIOD OF POTENTIAL STORM FORCE WINDS NEARSHORE. HIGH PRESSURE WILL THEN SETTLE INTO THE AREA FOR MONDAY NIGHT AND TUESDAY. ALLSOPP && .LOT WATCHES/WARNINGS/ADVISORIES... IL...HIGH WIND WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 8 PM SUNDAY. WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012 UNTIL 8 PM SUNDAY. IN...HIGH WIND WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM SUNDAY. LM...GALE WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673- LMZ675-LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 2 PM SUNDAY. GALE WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673- LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876- LMZ878...4 AM MONDAY TO 3 PM MONDAY. STORM WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673- LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876- LMZ878...2 PM SUNDAY TO 4 AM MONDAY. GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ563 UNTIL 3 PM MONDAY. GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...8 PM SUNDAY TO 4 AM MONDAY. STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...2 PM SUNDAY TO 8 PM SUNDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
142 PM EST SUN NOV 17 2013 .UPDATE... THE LONG TERM DISCUSSION HAS BEEN UPDATED BELOW. && .MESOSCALE UPDATE... LATEST SURFACE ANALYSIS SHOWS A WARM FRONT THAT EXTENDS FROM NW INDIANA SSEWD OVER PARKE COUNTY TO NEAR THE LOUISVILLE AREA. TEMPS IN THE WARM SECTOR ARE INTO THE LOWER 70S. LOW LEVEL JET IS SWLY WHICH SHOULD PUSH THE WARM FRONT NEWD OVER THE NEXT TWO HOURS. THIS IS AGREEABLE ANALYZING THE RAP MODEL WHICH PUTS FAVORABLE INSTABILITY AND SHEAR OVER THE WRN COUNTIES OF INDIANA BY 19Z. EXPECT STORMS TO DEVELOP OVER WRN SECTIONS OF INDIANA BY 2PM EST DEVELOPING INTO A DISCRETE LINE AHEAD OF MAIN COLD FRONT. LOOKS LIKE STORMS WILL SPREAD ACROSS WRN AND CENTRAL INDIANA BETWEEN 2PM EST AND 7PM EST. EXPECT TORNADOES...LARGE HAIL AND DAMAGING WINDS TO ACCOMPANY THESE STORMS. && .SYNOPSIS... ISSUED AT 355 AM EST SUN NOV 17 2013 SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND. && .NEAR TERM /UPDATE FOR TODAY/... ISSUED AT 927 AM EST SUN NOV 17 2013 NO SIGNIFICANT CHANGES MADE TO FORECASTS. GUSTS HAVE BEGUN. INTERMITTENT SUNSHINE WILL ADD TO INSTABILITY. STORM PREDICTION CENTER HAD EXPANDED HIGH RISK TO NEARLY ALL OF INDIANA BUT NO REAL CHANGE FOR CENTRAL INDIANA OTHER THAN ADDING EASTERN COUNTIES. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 355 AM EST SUN NOV 17 2013 MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY BELOW NORMAL TEMPERATURES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ISSUED AT 142 PM EST SUN NOV 17 2013 EXTENDED MODELS AND ENSEMBLES IN GOOD AGREEMENT THAT SEPARATE FRONTAL SYSTEMS AND FAST MOIST PACIFIC FLOW ALOFT ARE EXPECTED TO RESULT IN NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES AND SHOWER CHANCES WEDNESDAY NIGHT THROUGH SATURDAY. THEN...HIGH PRESSURE WILL BUILD IN FROM THE CANADIAN PRAIRIES WHICH SHOULD KEEP THE REMAINDER OF NEXT WEEKEND DRY WITH BELOW NORMAL TEMPERATURES. REGIONAL ALLBLEND IS HANDLING THINGS WELL. && .AVIATION /DISCUSSION FOR THE 171800Z TAF ISSUANCE/... ISSUED AT 1127 AM EST SUN NOV 17 2013 STRONG LOW PRESSURE SYSTEM WAS SPAWNING SUPERCELL THUNDERSTORMS ACROSS ILLINOIS AND MISSOURI LATE THIS MORNING. ADDITIONAL AFTERNOON SUPERCELL DEVELOPMENT IS EXPECTED ACROSS CENTRAL INDIANA THIS AFTERNOON FOLLOWED BY A LINE OF SEVERE STORMS. THE BEST TIMING FOR THE LINE...WHICH WILL BE JUST AHEAD OF THE FRONT...WILL BE IN THE LAF AND HUF AREAS AROUND 19Z-21Z AND IND AND BMG AROUND 20-22Z. CONFIDENCE IS GOOD REGARDING THE TIMING OF THIS SQUALL LINE. SO...WILL START WITH VCTS AND THEN GO WITH TEMPO THUNDERSTORMS FOR 2 HOURS WITH SEVERE GUSTS TO 50 KNOTS FROM THE SOUTHWEST AS STORM MOTION IS EXPECTED TO BE SOUTHWEST AT 50 KNOTS OR MORE. SOUTH AND SOUTHWEST GRADIENT WINDS ALONE SHOULD GUST TO 35 KNOTS OR MORE WITH SUSTAINED WINDS NEAR 25 KNOTS. MVFR AND POSSIBLY IFR CONDITIONS IN STORMS WILL IMPROVE TO VFR AS THE FRONT MOVES THROUGH WITH CLEARING LATE IN THE EVENING. SHOULD ONLY SCATTERED DIURNAL CU TOMORROW AFTER 16Z. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ MESO UPDATE...DWM SYNOPSIS...CP NEAR TERM...TUCEK SHORT TERM...CP LONG TERM....MK AVIATION...MK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
100 PM EST SUN NOV 17 2013 .UPDATE... ADDED MESOSCALE DISCUSSION. && .MESOSCALE UPDATE... LATEST SURFACE ANALYSIS SHOWS A WARM FRONT THAT EXTENDS FROM NW INDIANA SSEWD OVER PARKE COUNTY TO NEAR THE LOUISVILLE AREA. TEMPS IN THE WARM SECTOR ARE INTO THE LOWER 70S. LOW LEVEL JET IS SWLY WHICH SHOULD PUSH THE WARM FRONT NEWD OVER THE NEXT TWO HOURS. THIS IS AGREEABLE ANALYZING THE RAP MODEL WHICH PUTS FAVORABLE INSTABILITY AND SHEAR OVER THE WRN COUNTES OF INDIANA BY 19Z. EXPECT STORMS TO DEVELOP OVER WRN SECTIONS OF INDIANA BY 2PM EST DEVELOPING INTO A DISCRETE LINE AHEAD OF MAIN COLD FRONT. LOOKS LIKE STORMS WILL SPREAD ACROSS WRN AND CENTRAL INDIANA BETWEEN 2PM EST AND 7PM EST. EXPECT TORNADOES...LARGE HAIL AND DAMAGING WINDS TO ACCOMPANY THESE STORMS. && .SYNOPSIS... ISSUED AT 355 AM EST SUN NOV 17 2013 SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND. && .NEAR TERM /UPDATE FOR TODAY/... ISSUED AT 927 AM EST SUN NOV 17 2013 NO SIGNIFICANT CHANGES MADE TO FORECASTS. GUSTS HAVE BEGUN. INTERMITTENT SUNSHINE WILL ADD TO INSTABILITY. STORM PREDICTION CENTER HAD EXPANDED HIGH RISK TO NEARLY ALL OF INDIANA BUT NO REAL CHANGE FOR CENTRAL INDIANA OTHER THAN ADDING EASTERN COUNTIES. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 355 AM EST SUN NOV 17 2013 MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY BELOW NORMAL TEMPERATURES. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 147 AM EST SUN NOV 17 2013 ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY. THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR THE 171800Z TAF ISSUANCE/... ISSUED AT 1127 AM EST SUN NOV 17 2013 STRONG LOW PRESSURE SYSTEM WAS SPAWNING SUPERCELL THUNDERSTORMS ACROSS ILLINOIS AND MISSOURI LATE THIS MORNING. ADDITIONAL AFTERNOON SUPERCELL DEVELOPMENT IS EXPECTED ACROSS CENTRAL INDIANA THIS AFTERNOON FOLLOWED BY A LINE OF SEVERE STORMS. THE BEST TIMING FOR THE LINE...WHICH WILL BE JUST AHEAD OF THE FRONT...WILL BE IN THE LAF AND HUF AREAS AROUND 19Z-21Z AND IND AND BMG AROUND 20-22Z. CONFIDENCE IS GOOD REGARDING THE TIMING OF THIS SQUALL LINE. SO...WILL START WITH VCTS AND THEN GO WITH TEMPO THUNDERSTORMS FOR 2 HOURS WITH SEVERE GUSTS TO 50 KNOTS FROM THE SOUTHWEST AS STORM MOITON IS EXPECTED TO BE SOUTHWEST AT 50 KNOTS OR MORE. SOUTH AND SOUTHWEST GRADIENT WINDS ALONE SHOULD GUST TO 35 KNOTS OR MORE WITH SUSTAINED WINDS NEAR 25 KNOTS. MVFR AND POSSIBLY IFR CONDITIONS IN STORMS WILL IMPROVE TO VFR AS THE FRONT MOVES THROUGH WITH CLEARING LATE IN THE EVENING. SHOULD ONLY SCATTERED DIURNAL CU TOMORROW AFTER 16Z. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ MESO UPDATE...DWM SYNOPSIS...CP NEAR TERM...TUCEK SHORT TERM...CP LONG TERM....PUMA AVIATION...MK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
931 AM EST SUN NOV 17 2013 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 355 AM EST SUN NOV 17 2013 SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND. && .NEAR TERM /UPDATE FOR TODAY/... ISSUED AT 927 AM EST SUN NOV 17 2013 NO SIGNIFICANT CHANGES MADE TO FORECASTS. GUSTS HAVE BEGUN. INTERMITTENT SUNSHINE WILL ADD TO INSTABILITY. STORM PREDICTION CENTER HAD EXPANDED HIGH RISK TO NEARLY ALL OF INDIANA BUT NO REAL CHANGE FOR CENTRAL INDIANA OTHER THAN ADDING EASTERN COUNTIES. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 355 AM EST SUN NOV 17 2013 MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY BELOW NORMAL TEMPERATURES. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 147 AM EST SUN NOV 17 2013 ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY. THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR THE 171200Z TAFS/... ISSUED AT 511 AM EST SUN NOV 17 2013 POOR FLYING CONDITIONS ARE EXPECTED THIS TAF PERIOD AS MVFR TO IFR CONDITIONS WILL BE EXPECTED FOR THE NEXT 12 HOURS ALONG WITH GUSTY SOUTH TO SOUTHWEST WINDS. A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS INDIANA TODAY. HRRR REFLECTIVITY SHOWS AN EXPECTED BAND OF TSRA TO DEVELOP AND PUSH ACROSS INDIANA ALONG OR JUST SLIGHTLY AHEAD OF THE COLD FRONT THIS AFTERNOON. IN THE MEANTIME...RADAR CONTINUES TO SHOW SCT SHRA ACROSS CENTRAL INDIANA AS WARM AND MOIST AIR ARRIVES IN THE AREA ON SW WINDS. FORECAST SOUNDINGS SHOW GOOD LOWER LEVEL MOISTURE THIS MORNING...INDICATING THE MVFR TO IFR CIGS...FOLLOWED BY STEEP LAPSE RATES ALOFT LATER THIS AFTERNOON AS THE COLD FRONT APPROACHES AND PASSES. STRONG PRESSURE GRADIENT REMAINS IN PLACE AS A STRONG LLJ OF 50 KNTS IS EXPECTED TO PASS AHEAD OF THE COLD FRONT...THUS WILL CONTINUE TO INCLUDE GUSTY WINDS IN THE TAFS. IN THE WAKE OF THE FRONT...FORECAST SOUNDINGS SHOW STRONG SUBSIDENCE AND DRYING AND A RETURN TO VFR CONDITIONS BY LATE THIS EVENING. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ SYNOPSIS...CP NEAR TERM...TUCEK SHORT TERM...CP LONG TERM....PUMA AVIATION...JP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
930 AM EST SUN NOV 17 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 355 AM EST SUN NOV 17 2013 SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND. && .NEAR TERM /TODAY/... ISSUED AT 355 AM EST SUN NOV 17 2013 THE TRIGGER HAS BEEN PULLED ON THE HIGH RISK WITH CENTRAL INDIANA BEING UNDER THE GUN FOR SEVERE WEATHER TODAY. SPC HAS PLACED MUCH OF THE AREA IN A 30 PERCENT HATCHED RISK FOR TORNADOES...MEANING THERE IS A 30 PERCENT CHANCE OF AN EF2 OR STRONGER TORNADO WITHIN 25 MILES OF ANY GIVEN POINT. THE SYSTEM IS EXTREMELY DYNAMIC WITH THE UPPER TROUGH BECOMING NEGATIVELY TILTED AS IT SWINGS OUT OF ITS CURRENT POSITION OVER THE INTERMOUNTAIN WEST AND INTO THE UPPER MIDWEST BY 0Z. DEW POINTS ACROSS THE AREA ARE ALREADY IN THE UPPER 50S TO AROUND 60 IN THE SOUTH WITH LOW 60S UPSTREAM. GUIDANCE HIGHS FOR THE DAY HAVE COME BACK DOWN A BIT GIVEN CLOUD COVER SHOULD BE IN PLACE FOR THE ENTIRE DAY BUT STILL YIELDS HIGHS ACROSS THE AREA IN THE UPPER 60S TO LOWER 70S. THUS SURFACE BASED CAPES THE GFS ARE RUNNING IN THE LOW TO MIDDLE HUNDREDS FOR MIDDAY AND HIGHER IN THE NAM WITH MIXED LAYER CAPES IN THE LOW HUNDREDS. WHILE THESE INSTABILITY NUMBERS ARE NOT HIGH...THEY SHOULD BE SUFFICIENT GIVEN SIGNIFICANT SHEAR WITH LOW LEVEL...MID LEVEL AND UPPER LEVEL JET MAXES GOING THROUGH LATER TODAY. LONG CURVED HODOGRAPHS AND 0-1 KM HELICITY VALUES OF 300-500 SHOW THE SIGNIFICANT POTENTIAL FOR SUPERCELL AND TORNADO FORMATION. ONE POSSIBLE WRENCH IN TODAY/S EVENT FOR THIS FORECAST AREA IS THE OVERNIGHT CONVECTION. A BIT OF CONCERN THAT THIS COULD LEAVE A STABLE RAIN COOLED AIRMASS OVER THE AREA WITH A BOUNDARY ACROSS THE SOUTHERN FORECAST AREA OR JUST SOUTH OF THERE THAT COULD IN EFFECT INHIBIT DEVELOPMENT OVER MUCH OF THE FORECAST AREA DURING THE LATE MORNING/EARLY AFTERNOON...THUS PREVENTING SUPERCELL DEVELOPMENT. SHOULD THIS OCCUR...GREAT POTENTIAL WILL STILL BE IN PLACE FOR SIGNIFICANT DAMAGING WINDS AND SPIN UP TORNADOES WITH THE SQUALL LINE THAT SHOULD FORM AHEAD OF THE COLD FRONT BY LATE MORNING/EARLY AFTERNOON ACROSS CENTRAL ILLINOIS. THE RAPID REFRESH BRINGS THE DEVELOPING SQUALL LINE INTO THE NORTHWEST COUNTIES AROUND 19Z. THIS AGREES WITH SREF TIMING THAT BRINGS THE HIGHEST OMEGA THROUGH THE CENTRAL FORECAST AREA AROUND 21Z AND SWINGS THE FRONT AND ASSOCIATED UPWARD MOTION EAST OF THE AREA BY 0Z AND STUCK WITH THIS TIMING FOR HIGHEST POPS. ON NON-THUNDERSTORM WIND POTENTIAL...THE LOW PRESSURE SYSTEM WILL DEEPEN SIGNIFICANTLY AS IT TRAVERSES THE UPPER MIDWEST AND THIS COULD PRODUCE SOME STRONG WINDS JUST AHEAD OF OR MORE LIKELY JUST BEHIND THE COLD FRONT. THINK THE STRONGEST OF THESE WINDS WILL STAY NORTH OF THE FORECAST AREA CLOSER TO THE TRACK OF THE LOW AND THE GREATEST PRESSURE CHANGES...HOWEVER...WIND ADVISORY STRENGTH GUST OF 50 MPH STILL LOOK LIKE A GOOD POSSIBILITY AND THUS CONTINUED WITH WIND ADVISORY FOR THE AREA. THINK THE NORTHERN COUNTIES COULD FLIRT WITH HIGH WIND WARNING CRITERIA...BUT AT THIS POINT THINK THEY WILL STAY IN HIGH END ADVISORY TERRITORY. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 355 AM EST SUN NOV 17 2013 MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY BELOW NORMAL TEMPERATURES. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 147 AM EST SUN NOV 17 2013 ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY. THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR THE 171500Z IND TAF UPDATE/... ISSUED AT 930 AM EST SUN NOV 17 2013 INCREASED WINDS TO 16 KNOTS WITH GUSTS TO 28 KNOTS AS THE ATMOSPHERIC MIXING HAS BEGUN. ALSO...KEPT MVFR CEILINGS AND VCSH WITH RADAR SHOWING SCATTERED WEAK SHOWER ACTIVITY IN THE VICINITY. PREVIOUS DISCUSSION FOLLOWS... POOR FLYING CONDITIONS ARE EXPECTED THIS TAF PERIOD AS MVFR TO IFR CONDITIONS WILL BE EXPECTED FOR THE NEXT 12 HOURS ALONG WITH GUSTY SOUTH TO SOUTHWEST WINDS. A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS INDIANA TODAY. HRRR REFLECTIVITY SHOWS AN EXPECTED BAND OF TSRA TO DEVELOP AND PUSH ACROSS INDIANA ALONG OR JUST SLIGHTLY AHEAD OF THE COLD FRONT THIS AFTERNOON. IN THE MEANTIME...RADAR CONTINUES TO SHOW SCT SHRA ACROSS CENTRAL INDIANA AS WARM AND MOIST AIR ARRIVES IN THE AREA ON SW WINDS. FORECAST SOUNDINGS SHOW GOOD LOWER LEVEL MOISTURE THIS MORNING...INDICATING THE MVFR TO IFR CIGS...FOLLOWED BY STEEP LAPSE RATES ALOFT LATER THIS AFTERNOON AS THE COLD FRONT APPROACHES AND PASSES. STRONG PRESSURE GRADIENT REMAINS IN PLACE AS A STRONG LLJ OF 50 KNTS IS EXPECTED TO PASS AHEAD OF THE COLD FRONT...THUS WILL CONTINUE TO INCLUDE GUSTY WINDS IN THE TAFS. IN THE WAKE OF THE FRONT...FORECAST SOUNDINGS SHOW STRONG SUBSIDENCE AND DRYING AND A RETURN TO VFR CONDITIONS BY LATE THIS EVENING. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM NOON TODAY TO 9 PM EST THIS EVENING FOR INZ021-028>031-035>049-051>057-060>065-067>072. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....PUMA AVIATION...JP/MK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
523 AM EST SUN NOV 17 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 355 AM EST SUN NOV 17 2013 SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND. && .NEAR TERM /TODAY/... ISSUED AT 355 AM EST SUN NOV 17 2013 THE TRIGGER HAS BEEN PULLED ON THE HIGH RISK WITH CENTRAL INDIANA BEING UNDER THE GUN FOR SEVERE WEATHER TODAY. SPC HAS PLACED MUCH OF THE AREA IN A 30 PERCENT HATCHED RISK FOR TORNADOES...MEANING THERE IS A 30 PERCENT CHANCE OF AN EF2 OR STRONGER TORNADO WITHIN 25 MILES OF ANY GIVEN POINT. THE SYSTEM IS EXTREMELY DYNAMIC WITH THE UPPER TROUGH BECOMING NEGATIVELY TILTED AS IT SWINGS OUT OF ITS CURRENT POSITION OVER THE INTERMOUNTAIN WEST AND INTO THE UPPER MIDWEST BY 0Z. DEW POINTS ACROSS THE AREA ARE ALREADY IN THE UPPER 50S TO AROUND 60 IN THE SOUTH WITH LOW 60S UPSTREAM. GUIDANCE HIGHS FOR THE DAY HAVE COME BACK DOWN A BIT GIVEN CLOUD COVER SHOULD BE IN PLACE FOR THE ENTIRE DAY BUT STILL YIELDS HIGHS ACROSS THE AREA IN THE UPPER 60S TO LOWER 70S. THUS SURFACE BASED CAPES THE GFS ARE RUNNING IN THE LOW TO MIDDLE HUNDREDS FOR MIDDAY AND HIGHER IN THE NAM WITH MIXED LAYER CAPES IN THE LOW HUNDREDS. WHILE THESE INSTABILITY NUMBERS ARE NOT HIGH...THEY SHOULD BE SUFFICIENT GIVEN SIGNIFICANT SHEAR WITH LOW LEVEL...MID LEVEL AND UPPER LEVEL JET MAXES GOING THROUGH LATER TODAY. LONG CURVED HODOGRAPHS AND 0-1 KM HELICITY VALUES OF 300-500 SHOW THE SIGNIFICANT POTENTIAL FOR SUPERCELL AND TORNADO FORMATION. ONE POSSIBLE WRENCH IN TODAY/S EVENT FOR THIS FORECAST AREA IS THE OVERNIGHT CONVECTION. A BIT OF CONCERN THAT THIS COULD LEAVE A STABLE RAIN COOLED AIRMASS OVER THE AREA WITH A BOUNDARY ACROSS THE SOUTHERN FORECAST AREA OR JUST SOUTH OF THERE THAT COULD IN EFFECT INHIBIT DEVELOPMENT OVER MUCH OF THE FORECAST AREA DURING THE LATE MORNING/EARLY AFTERNOON...THUS PREVENTING SUPERCELL DEVELOPMENT. SHOULD THIS OCCUR...GREAT POTENTIAL WILL STILL BE IN PLACE FOR SIGNIFICANT DAMAGING WINDS AND SPIN UP TORNADOES WITH THE SQUALL LINE THAT SHOULD FORM AHEAD OF THE COLD FRONT BY LATE MORNING/EARLY AFTERNOON ACROSS CENTRAL ILLINOIS. THE RAPID REFRESH BRINGS THE DEVELOPING SQUALL LINE INTO THE NORTHWEST COUNTIES AROUND 19Z. THIS AGREES WITH SREF TIMING THAT BRINGS THE HIGHEST OMEGA THROUGH THE CENTRAL FORECAST AREA AROUND 21Z AND SWINGS THE FRONT AND ASSOCIATED UPWARD MOTION EAST OF THE AREA BY 0Z AND STUCK WITH THIS TIMING FOR HIGHEST POPS. ON NON-THUNDERSTORM WIND POTENTIAL...THE LOW PRESSURE SYSTEM WILL DEEPEN SIGNIFICANTLY AS IT TRAVERSES THE UPPER MIDWEST AND THIS COULD PRODUCE SOME STRONG WINDS JUST AHEAD OF OR MORE LIKELY JUST BEHIND THE COLD FRONT. THINK THE STRONGEST OF THESE WINDS WILL STAY NORTH OF THE FORECAST AREA CLOSER TO THE TRACK OF THE LOW AND THE GREATEST PRESSURE CHANGES...HOWEVER...WIND ADVISORY STRENGTH GUST OF 50 MPH STILL LOOK LIKE A GOOD POSSIBILITY AND THUS CONTINUED WITH WIND ADVISORY FOR THE AREA. THINK THE NORTHERN COUNTIES COULD FLIRT WITH HIGH WIND WARNING CRITERIA...BUT AT THIS POINT THINK THEY WILL STAY IN HIGH END ADVISORY TERRITORY. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 355 AM EST SUN NOV 17 2013 MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY BELOW NORMAL TEMPERATURES. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 147 AM EST SUN NOV 17 2013 ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY. THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR THE 171200Z TAFS/... ISSUED AT 511 AM EST SUN NOV 17 2013 POOR FLYING CONDITIONS ARE EXPECTED THIS TAF PERIOD AS MVFR TO IFR CONDITIONS WILL BE EXPECTED FOR THE NEXT 12 HOURS ALONG WITH GUSTY SOUTH TO SOUTHWEST WINDS. A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS INDIANA TODAY. HRRR REFLECTIVITY SHOWS AN EXPECTED BAND OF TSRA TO DEVELOP AND PUSH ACROSS INDIANA ALONG OR JUST SLIGHTLY AHEAD OF THE COLD FRONT THIS AFTERNOON. IN THE MEANTIME...RADAR CONTINUES TO SHOW SCT SHRA ACROSS CENTRAL INDIANA AS WARM AND MOIST AIR ARRIVES IN THE AREA ON SW WINDS. FORECAST SOUNDINGS SHOW GOOD LOWER LEVEL MOISTURE THIS MORNING...INDICATING THE MVFR TO IFR CIGS...FOLLOWED BY STEEP LAPSE RATES ALOFT LATER THIS AFTERNOON AS THE COLD FRONT APPROACHES AND PASSES. STRONG PRESSURE GRADIENT REMAINS IN PLACE AS A STRONG LLJ OF 50 KNTS IS EXPECTED TO PASS AHEAD OF THE COLD FRONT...THUS WILL CONTINUE TO INCLUDE GUSTY WINDS IN THE TAFS. IN THE WAKE OF THE FRONT...FORECAST SOUNDINGS SHOW STRONG SUBSIDENCE AND DRYING AND A RETURN TO VFR CONDITIONS BY LATE THIS EVENING. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM NOON TODAY TO 9 PM EST THIS EVENING FOR INZ021-028>031-035>049-051>057-060>065-067>072. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....PUMA AVIATION...JP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
334 AM EST SUN NOV 17 2013 .UPDATE... AVIATION SECTION UPDATED. && .SYNOPSIS... ISSUED AT 138 PM EST SAT NOV 16 2013 A POTENT AND STRENGTHENING LOW PRESSURE SYSTEM WILL LIFT NORTHEAST OVER THE WESTERN GREAT LAKES LATE SUNDAY. AN ASSOCIATED STRONG COLD FRONT WILL SWEEP EAST ACROSS CENTRAL INDIANA SUNDAY AFTERNOON AND EVENING. INCREASING MOISTURE STREAMING NORTHWARD AHEAD OF THE FRONT WILL INTERACT WITH THE FRONT AND RESULT IN WIDESPREAD SHOWERS AND ALSO THUNDERSTORMS TONIGHT THROUGH SUNDAY EVENING. THERE IS ALSO A MODERATE RISK OF SEVERE WEATHER SUNDAY AND SUNDAY EVENING WITH DAMAGING WINDS THE MAIN THREAT ALONG WITH HAIL AND ISOLATED TORNADOES. HIGH PRESSURE WILL BUILD IN NEXT WEEK WITH DRY CONDITIONS AND NORMAL TO BELOW NORMAL TEMPERATURES. THE NEXT CHANCE OF SHOWERS WILL BE LATE IN THE WEEK AND INTO THE WEEKEND AS ANOTHER COLD FRONT TAKES AIM AT THE OHIO VALLEY. && .NEAR TERM /OVERNIGHT/... ISSUED AT 1007 PM EST SAT NOV 16 2013 RAIN SHOWERS BECOME MORE ORGANIZED AND INCREASING IN COVERAGE ACROSS THE WESTERN HALF OF THE FORECAST AREA THIS EVENING AS STRONG LOW LEVEL JET APPROACHES FROM THE WEST. WINDS HAVE STEADILY INCREASED THROUGH THE EVENING...WITH GUSTS TO 20-25MPH BECOMING MORE COMMON. TEMPS REMAINED PRIMARILY IN THE UPPER 50S AT 0230Z. EVENING SURFACE ANALYSIS INDICATING AN OCCLUDING LOW PRESSURE SYSTEM OVER MINNESOTA WITH A SECONDARY LOW EJECTING INTO THE CENTRAL PLAINS. A SUBTLE WARM FRONT EXTENDING FROM THE OCCLUDED LOW ACROSS CENTRAL ILLINOIS AND SOUTHWEST INDIANA WILL LIFT NORTH ACROSS THE FORECAST AREA OVERNIGHT. BROAD 55-60KT 850MB JET WILL TRANSPORT DEEP MOISTURE INTO THE REGION TONIGHT...WITH MESOANALYSIS INDICATING A PLUME OF 1.2-1.4 IN PRECIP WATER VALUES POISED TO EXPAND ACROSS THE FORECAST AREA WITHIN THE NEXT FEW HOURS. BOTH THE HRRR AND THE WRF-NMM BOTH CONSISTENT IN EXPANDING PRECIP OVER CENTRAL INDIANA INTO THE OVERNIGHT...WITH WIDESPREAD RAIN FROM 06-12Z. COULD SEE LOCALLY HEAVY RAINFALL CONSIDERING THE HIGH PRECIP WATER VALUES WITH POTENTIAL FOR MANY LOCATIONS TO PICK UP 0.50 TO 1 INCH OVERNIGHT. SEEING A SLOW EXPANSION IN LIGHTNING STRIKES OVER THE MID MISSISSIPPI VALLEY AS WELL AS ELEVATED INSTABILITY INCREASES. WILL CONTINUE WITH THE ISOLATED THUNDER MENTION OVERNIGHT. SURFACE BASED CONVECTION SHOULD REMAIN TO THE WEST OF THE WABASH RIVER THROUGH DAYBREAK. POTENTIAL DOES EXIST LATE TONIGHT FOR A FEW STRONGER STORMS TO PRODUCE HAIL...ESPECIALLY OVER THE LOWER WABASH VALLEY...BUT OVERALL ANTICIPATE CONVECTION TO REMAIN SUBSEVERE THROUGH 12Z. ZONE AND GRID UPDATES OUT. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 138 PM EST SAT NOV 16 2013 OBVIOUS FOCUS FOR THE SHORT TERM WILL BE ON SEVERE WEATHER POTENTIAL ON SUNDAY AND SUNDAY EVENING AS A CLASSIC FALL SEVERE WEATHER OUTBREAK LOOKS MORE AND MORE LIKELY WITH DAMAGING WINDS THE MAIN THREAT...BUT TORNADOES CERTAINLY ARE A CONCERN AS WELL. MODELS ARE NOW IN GOOD AGREEMENT THAT PACIFIC NORTHWEST TROUGH WILL BECOME NEGATIVELY TILTED ON SUNDAY CAUSING RAPID INTENSIFICATION OF A SURFACE LOW PRESSURE SYSTEM. DEEPENING SURFACE LOW WILL LIFT TO NORTHWEST LOWER MICHIGAN OR THE NORTHERN WATERS OF LAKE MICHIGAN BY 00Z MONDAY. ASSOCIATED COLD FRONT WILL THEN SWEEP QUICKLY EAST ACROSS CENTRAL INDIANA FROM AROUND 18Z SUNDAY TO 00Z MONDAY. PRIOR TO THAT...A STALLED COLD FRONT IS EXPECTED TO RETURN NORTH AS A WARM FRONT ACROSS CENTRAL INDIANA AROUND 12-16Z SUNDAY. UPPER SPEED MAX TO AROUND 120 KNOTS AROUND THE BASE OF THE TROUGH ALONG WITH WEAKENING...BUT STILL FORMIDABLE OHIO VALLEY UPPER JET WILL PROVIDE BROAD DILUENT FLOW ON TOP OF WARM CONVEYOR BELT/60 PLUS KNOT LOW LEVEL JET AHEAD OF THE COLD FRONT. VERY STRONG WIND SHEAR /40 KNOTS OR MORE FROM 1000-700 MILLIBARS AND 60 KNOTS OR MORE FROM 1000-500 MILLIBARS/ ALONG WITH LONG CURVED HODOGRAPHS AND VERY HIGH HELICITY NUMBERS OVER 300 METERS SQUARED PER SECONDS SQUARED WILL PROVIDE AMPLE SPIN IN THE ATMOSPHERE FOR TORNADIC ACTIVITY GIVEN ENOUGH INSTABILITY. REGARDING INSTABILITY...TEMPERATURES IN THE UPPER 60S TO MID 70S WITH WARM ADVECTION ALONE...DEW POINTS APPROACHING 60 DEGREES...700-500 MILLIBAR LAPSE RATES TO 6 DEGREES CELSIUS PER KILOMETER OR MORE AND DRY INTRUSION ALOFT SHOULD RESULT IN AT LEAST SOME SURFACE INSTABILITY DESPITE EXPECTED THICK CLOUD COVER AND EARLIER OR ONGOING OVERNIGHT AND MORNING CONVECTION. EVEN THE LESS UNSTABLE...12Z DETERMINISTIC GFS IS NOW FORECASTING 500 J/KG CAPE OR MORE DURING THE AFTERNOON HOURS BUT WEAKENING SIGNIFICANTLY AFTER DARK. BASED ON THE ABOVE...AGREE WITH SPC DAY2 MODERATE RISK AND EXPECT A SEVERE WEATHER OUTBREAK SUNDAY MORNING THROUGH EARLY SUNDAY EVENING. WILL HAVE TO WATCH OUT FOR DISCRETE SUPERCELLS ESPECIALLY DURING THE MORNING NEAR THE SURFACE WARM FRONT AND AFTERNOON IN THE WARM SECTOR THEN...WITH ELONGATED FRONTOGENESIS OCCURRING NEAR THE COLD FRONT...SHOULD SEE LINEAR ACTIVITY MOVE THROUGH AROUND 18Z IN THE NORTHWEST TO 00Z IN THE SOUTHEAST ALONG AND JUST AHEAD OF THE FRONT. THIS WILL BE MORE OF A WIDESPREAD DAMAGING WIND THREAT BUT WITH ALSO THE POTENTIAL FOR A FEW BRIEF SPIN UPS IN ANY CIRCULATION COUPLET. HEAVY RAIN COULD ALSO BE AN ISSUE ESPECIALLY EARLY...BEFORE THE DRY PUNCH ALOFT MOVES IN. IT WILL ALSO CONTINUE TO BE WINDY...BUT DO NOT THINK THE HIGHER WINDS AT THE TOP OF THE BOUNDARY LAYER FROM THE BUFKIT 12Z NAM WILL BE ABLE TO MIX DOWN WITHOUT SUNSHINE. WILL CONTINUE WITH CATEGORICAL POPS PER MOS AND DROPPING DRAMATICALLY AFTER 06Z MONDAY AND ALTOGETHER AFTER 06Z. THE REST OF THE SHORT TERM WILL BE CHARACTERIZED BY DRY WEATHER WITH SLIGHTLY BELOW NORMAL TEMPERATURES AS CANADIAN HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT. MOS HIGHS IN THE UPPER 40S TO LOWER 50S MONDAY AND ALLBLEND IN THE 40S ON TUESDAY LOOK GOOD. ALSO...SHOULD SEE PLENTY OF SUNSHINE... ESPECIALLY TUESDAY AS THE HIGH PASSES OVERHEAD. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 147 AM EST SUN NOV 17 2013 ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY. THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR THE 170900Z IND TAF UPDATE/... IFR CONDITIONS ARE EXPECTED TO IMPROVE TO MVFR CIGS OR BETTER AS THE CURRENT WAVE OF PRECIP OVER EASTERN AND SOUTHERN INDIANA DEPARTS TO THE EAST. HAVE UPDATED THE TAFS IN THE SHORT TERM TO REFLECT THESE EXPECTED TRENDS. /DISCUSSION FOR THE 170600Z TAFS/... ISSUED AT 1130 PM EST SAT NOV 16 2013 UPPER DISTURBANCE CURRENTLY LIFTING OUT OF NORTHERN MISSOURI WITH INCREASING RAIN/EMBEDDED CONVECTION ASSOCIATED WITH IT. THIS DISTURBANCE...COUPLED WITH LIFT ALONG A STRONG LOW LEVEL JET AND A PLUME OF STEEPER MID LEVEL LAPSE RATES ADVECTING INTO THE AREA...SUGGEST FAIRLY WIDESPREAD RAIN/EMBEDDED CONVECTION SHOULD AFFECT THE TAF SITES OVERNIGHT. THIS DISTURBANCE EXPECTED TO CONTINUE PUSHING OFF TO THE NORTHEAST EARLY SUNDAY...SO RAIN/CONVECTIVE THREAT SHOULD DIMINISH AROUND SUNRISE OR SHORTLY AFTER. BRIEF PERIODS OF IFR VISIBILITY RESTRICTIONS EXPECTED WITHIN THE HEAVIER CELLS. OTHERWISE...STRONG LOW LEVEL JET OF 55-60 KTS EXPECTED TO MOVE OVERHEAD OVERNIGHT. STARTING TO SEE WIND GUSTS REACH THE SURFACE...SO DOUBTFUL THERE IS MUCH OF A CHANCE OF THE NOCTURNAL INVERSION DEVELOPING. AS A RESULT...DON/T THINK LOW LEVEL WIND SHEAR WILL REACH CRITERIA. OUTSIDE OF ANY CONVECTION...EXPECTING CEILINGS GENERALLY AROUND 020 THROUGH MIDDAY ON SUNDAY. SURFACE WIND GUSTS 25-30 KTS FROM 170-190 DEGREES EXPECTED THROUGH THE LATE MORNING...WITH MODELS SUGGEST SOME GUSTS AROUND 35 KTS TOWARDS MIDDAY. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM NOON TODAY TO 9 PM EST THIS EVENING FOR INZ021-028>031-035>049-051>057-060>065-067>072. && $$ SYNOPSIS...MK NEAR TERM...RYAN SHORT TERM...MK LONG TERM....PUMA AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
158 AM EST SUN NOV 17 2013 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 138 PM EST SAT NOV 16 2013 A POTENT AND STRENGTHENING LOW PRESSURE SYSTEM WILL LIFT NORTHEAST OVER THE WESTERN GREAT LAKES LATE SUNDAY. AN ASSOCIATED STRONG COLD FRONT WILL SWEEP EAST ACROSS CENTRAL INDIANA SUNDAY AFTERNOON AND EVENING. INCREASING MOISTURE STREAMING NORTHWARD AHEAD OF THE FRONT WILL INTERACT WITH THE FRONT AND RESULT IN WIDESPREAD SHOWERS AND ALSO THUNDERSTORMS TONIGHT THROUGH SUNDAY EVENING. THERE IS ALSO A MODERATE RISK OF SEVERE WEATHER SUNDAY AND SUNDAY EVENING WITH DAMAGING WINDS THE MAIN THREAT ALONG WITH HAIL AND ISOLATED TORNADOES. HIGH PRESSURE WILL BUILD IN NEXT WEEK WITH DRY CONDITIONS AND NORMAL TO BELOW NORMAL TEMPERATURES. THE NEXT CHANCE OF SHOWERS WILL BE LATE IN THE WEEK AND INTO THE WEEKEND AS ANOTHER COLD FRONT TAKES AIM AT THE OHIO VALLEY. && .NEAR TERM /OVERNIGHT/... ISSUED AT 1007 PM EST SAT NOV 16 2013 RAIN SHOWERS BECOME MORE ORGANIZED AND INCREASING IN COVERAGE ACROSS THE WESTERN HALF OF THE FORECAST AREA THIS EVENING AS STRONG LOW LEVEL JET APPROACHES FROM THE WEST. WINDS HAVE STEADILY INCREASED THROUGH THE EVENING...WITH GUSTS TO 20-25MPH BECOMING MORE COMMON. TEMPS REMAINED PRIMARILY IN THE UPPER 50S AT 0230Z. EVENING SURFACE ANALYSIS INDICATING AN OCCLUDING LOW PRESSURE SYSTEM OVER MINNESOTA WITH A SECONDARY LOW EJECTING INTO THE CENTRAL PLAINS. A SUBTLE WARM FRONT EXTENDING FROM THE OCCLUDED LOW ACROSS CENTRAL ILLINOIS AND SOUTHWEST INDIANA WILL LIFT NORTH ACROSS THE FORECAST AREA OVERNIGHT. BROAD 55-60KT 850MB JET WILL TRANSPORT DEEP MOISTURE INTO THE REGION TONIGHT...WITH MESOANALYSIS INDICATING A PLUME OF 1.2-1.4 IN PRECIP WATER VALUES POISED TO EXPAND ACROSS THE FORECAST AREA WITHIN THE NEXT FEW HOURS. BOTH THE HRRR AND THE WRF-NMM BOTH CONSISTENT IN EXPANDING PRECIP OVER CENTRAL INDIANA INTO THE OVERNIGHT...WITH WIDESPREAD RAIN FROM 06-12Z. COULD SEE LOCALLY HEAVY RAINFALL CONSIDERING THE HIGH PRECIP WATER VALUES WITH POTENTIAL FOR MANY LOCATIONS TO PICK UP 0.50 TO 1 INCH OVERNIGHT. SEEING A SLOW EXPANSION IN LIGHTNING STRIKES OVER THE MID MISSISSIPPI VALLEY AS WELL AS ELEVATED INSTABILITY INCREASES. WILL CONTINUE WITH THE ISOLATED THUNDER MENTION OVERNIGHT. SURFACE BASED CONVECTION SHOULD REMAIN TO THE WEST OF THE WABASH RIVER THROUGH DAYBREAK. POTENTIAL DOES EXIST LATE TONIGHT FOR A FEW STRONGER STORMS TO PRODUCE HAIL...ESPECIALLY OVER THE LOWER WABASH VALLEY...BUT OVERALL ANTICIPATE CONVECTION TO REMAIN SUBSEVERE THROUGH 12Z. ZONE AND GRID UPDATES OUT. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 138 PM EST SAT NOV 16 2013 OBVIOUS FOCUS FOR THE SHORT TERM WILL BE ON SEVERE WEATHER POTENTIAL ON SUNDAY AND SUNDAY EVENING AS A CLASSIC FALL SEVERE WEATHER OUTBREAK LOOKS MORE AND MORE LIKELY WITH DAMAGING WINDS THE MAIN THREAT...BUT TORNADOES CERTAINLY ARE A CONCERN AS WELL. MODELS ARE NOW IN GOOD AGREEMENT THAT PACIFIC NORTHWEST TROUGH WILL BECOME NEGATIVELY TILTED ON SUNDAY CAUSING RAPID INTENSIFICATION OF A SURFACE LOW PRESSURE SYSTEM. DEEPENING SURFACE LOW WILL LIFT TO NORTHWEST LOWER MICHIGAN OR THE NORTHERN WATERS OF LAKE MICHIGAN BY 00Z MONDAY. ASSOCIATED COLD FRONT WILL THEN SWEEP QUICKLY EAST ACROSS CENTRAL INDIANA FROM AROUND 18Z SUNDAY TO 00Z MONDAY. PRIOR TO THAT...A STALLED COLD FRONT IS EXPECTED TO RETURN NORTH AS A WARM FRONT ACROSS CENTRAL INDIANA AROUND 12-16Z SUNDAY. UPPER SPEED MAX TO AROUND 120 KNOTS AROUND THE BASE OF THE TROUGH ALONG WITH WEAKENING...BUT STILL FORMIDABLE OHIO VALLEY UPPER JET WILL PROVIDE BROAD DILUENT FLOW ON TOP OF WARM CONVEYOR BELT/60 PLUS KNOT LOW LEVEL JET AHEAD OF THE COLD FRONT. VERY STRONG WIND SHEAR /40 KNOTS OR MORE FROM 1000-700 MILLIBARS AND 60 KNOTS OR MORE FROM 1000-500 MILLIBARS/ ALONG WITH LONG CURVED HODOGRAPHS AND VERY HIGH HELICITY NUMBERS OVER 300 METERS SQUARED PER SECONDS SQUARED WILL PROVIDE AMPLE SPIN IN THE ATMOSPHERE FOR TORNADIC ACTIVITY GIVEN ENOUGH INSTABILITY. REGARDING INSTABILITY...TEMPERATURES IN THE UPPER 60S TO MID 70S WITH WARM ADVECTION ALONE...DEW POINTS APPROACHING 60 DEGREES...700-500 MILLIBAR LAPSE RATES TO 6 DEGREES CELSIUS PER KILOMETER OR MORE AND DRY INTRUSION ALOFT SHOULD RESULT IN AT LEAST SOME SURFACE INSTABILITY DESPITE EXPECTED THICK CLOUD COVER AND EARLIER OR ONGOING OVERNIGHT AND MORNING CONVECTION. EVEN THE LESS UNSTABLE...12Z DETERMINISTIC GFS IS NOW FORECASTING 500 J/KG CAPE OR MORE DURING THE AFTERNOON HOURS BUT WEAKENING SIGNIFICANTLY AFTER DARK. BASED ON THE ABOVE...AGREE WITH SPC DAY2 MODERATE RISK AND EXPECT A SEVERE WEATHER OUTBREAK SUNDAY MORNING THROUGH EARLY SUNDAY EVENING. WILL HAVE TO WATCH OUT FOR DISCRETE SUPERCELLS ESPECIALLY DURING THE MORNING NEAR THE SURFACE WARM FRONT AND AFTERNOON IN THE WARM SECTOR THEN...WITH ELONGATED FRONTOGENESIS OCCURRING NEAR THE COLD FRONT...SHOULD SEE LINEAR ACTIVITY MOVE THROUGH AROUND 18Z IN THE NORTHWEST TO 00Z IN THE SOUTHEAST ALONG AND JUST AHEAD OF THE FRONT. THIS WILL BE MORE OF A WIDESPREAD DAMAGING WIND THREAT BUT WITH ALSO THE POTENTIAL FOR A FEW BRIEF SPIN UPS IN ANY CIRCULATION COUPLET. HEAVY RAIN COULD ALSO BE AN ISSUE ESPECIALLY EARLY...BEFORE THE DRY PUNCH ALOFT MOVES IN. IT WILL ALSO CONTINUE TO BE WINDY...BUT DO NOT THINK THE HIGHER WINDS AT THE TOP OF THE BOUNDARY LAYER FROM THE BUFKIT 12Z NAM WILL BE ABLE TO MIX DOWN WITHOUT SUNSHINE. WILL CONTINUE WITH CATEGORICAL POPS PER MOS AND DROPPING DRAMATICALLY AFTER 06Z MONDAY AND ALTOGETHER AFTER 06Z. THE REST OF THE SHORT TERM WILL BE CHARACTERIZED BY DRY WEATHER WITH SLIGHTLY BELOW NORMAL TEMPERATURES AS CANADIAN HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT. MOS HIGHS IN THE UPPER 40S TO LOWER 50S MONDAY AND ALLBLEND IN THE 40S ON TUESDAY LOOK GOOD. ALSO...SHOULD SEE PLENTY OF SUNSHINE... ESPECIALLY TUESDAY AS THE HIGH PASSES OVERHEAD. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 147 AM EST SUN NOV 17 2013 ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY. THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR THE 170600Z TAFS/... ISSUED AT 1130 PM EST SAT NOV 16 2013 UPPER DISTURBANCE CURRENTLY LIFTING OUT OF NORTHERN MISSOURI WITH INCREASING RAIN/EMBEDDED CONVECTION ASSOCIATED WITH IT. THIS DISTURBANCE...COUPLED WITH LIFT ALONG A STRONG LOW LEVEL JET AND A PLUME OF STEEPER MID LEVEL LAPSE RATES ADVECTING INTO THE AREA...SUGGEST FAIRLY WIDESPREAD RAIN/EMBEDDED CONVECTION SHOULD AFFECT THE TAF SITES OVERNIGHT. THIS DISTURBANCE EXPECTED TO CONTINUE PUSHING OFF TO THE NORTHEAST EARLY SUNDAY...SO RAIN/CONVECTIVE THREAT SHOULD DIMINISH AROUND SUNRISE OR SHORTLY AFTER. BRIEF PERIODS OF IFR VISIBILITY RESTRICTIONS EXPECTED WITHIN THE HEAVIER CELLS. OTHERWISE...STRONG LOW LEVEL JET OF 55-60 KTS EXPECTED TO MOVE OVERHEAD OVERNIGHT. STARTING TO SEE WIND GUSTS REACH THE SURFACE...SO DOUBTFUL THERE IS MUCH OF A CHANCE OF THE NOCTURNAL INVERSION DEVELOPING. AS A RESULT...DON/T THINK LOW LEVEL WIND SHEAR WILL REACH CRITERIA. OUTSIDE OF ANY CONVECTION...EXPECTING CEILINGS GENERALLY AROUND 020 THROUGH MIDDAY ON SUNDAY. SURFACE WIND GUSTS 25-30 KTS FROM 170-190 DEGREES EXPECTED THROUGH THE LATE MORNING...WITH MODELS SUGGEST SOME GUSTS AROUND 35 KTS TOWARDS MIDDAY. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM NOON TODAY TO 9 PM EST THIS EVENING FOR INZ021-028>031-035>049-051>057-060>065-067>072. && $$ SYNOPSIS...MK NEAR TERM...RYAN SHORT TERM...MK LONG TERM....PUMA AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1130 PM EST SAT NOV 16 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 138 PM EST SAT NOV 16 2013 A POTENT AND STRENGTHENING LOW PRESSURE SYSTEM WILL LIFT NORTHEAST OVER THE WESTERN GREAT LAKES LATE SUNDAY. AN ASSOCIATED STRONG COLD FRONT WILL SWEEP EAST ACROSS CENTRAL INDIANA SUNDAY AFTERNOON AND EVENING. INCREASING MOISTURE STREAMING NORTHWARD AHEAD OF THE FRONT WILL INTERACT WITH THE FRONT AND RESULT IN WIDESPREAD SHOWERS AND ALSO THUNDERSTORMS TONIGHT THROUGH SUNDAY EVENING. THERE IS ALSO A MODERATE RISK OF SEVERE WEATHER SUNDAY AND SUNDAY EVENING WITH DAMAGING WINDS THE MAIN THREAT ALONG WITH HAIL AND ISOLATED TORNADOES. HIGH PRESSURE WILL BUILD IN NEXT WEEK WITH DRY CONDITIONS AND NORMAL TO BELOW NORMAL TEMPERATURES. THE NEXT CHANCE OF SHOWERS WILL BE LATE IN THE WEEK AND INTO THE WEEKEND AS ANOTHER COLD FRONT TAKES AIM AT THE OHIO VALLEY. && .NEAR TERM /OVERNIGHT/... ISSUED AT 1007 PM EST SAT NOV 16 2013 RAIN SHOWERS BECOME MORE ORGANIZED AND INCREASING IN COVERAGE ACROSS THE WESTERN HALF OF THE FORECAST AREA THIS EVENING AS STRONG LOW LEVEL JET APPROACHES FROM THE WEST. WINDS HAVE STEADILY INCREASED THROUGH THE EVENING...WITH GUSTS TO 20-25MPH BECOMING MORE COMMON. TEMPS REMAINED PRIMARILY IN THE UPPER 50S AT 0230Z. EVENING SURFACE ANALYSIS INDICATING AN OCCLUDING LOW PRESSURE SYSTEM OVER MINNESOTA WITH A SECONDARY LOW EJECTING INTO THE CENTRAL PLAINS. A SUBTLE WARM FRONT EXTENDING FROM THE OCCLUDED LOW ACROSS CENTRAL ILLINOIS AND SOUTHWEST INDIANA WILL LIFT NORTH ACROSS THE FORECAST AREA OVERNIGHT. BROAD 55-60KT 850MB JET WILL TRANSPORT DEEP MOISTURE INTO THE REGION TONIGHT...WITH MESOANALYSIS INDICATING A PLUME OF 1.2-1.4 IN PRECIP WATER VALUES POISED TO EXPAND ACROSS THE FORECAST AREA WITHIN THE NEXT FEW HOURS. BOTH THE HRRR AND THE WRF-NMM BOTH CONSISTENT IN EXPANDING PRECIP OVER CENTRAL INDIANA INTO THE OVERNIGHT...WITH WIDESPREAD RAIN FROM 06-12Z. COULD SEE LOCALLY HEAVY RAINFALL CONSIDERING THE HIGH PRECIP WATER VALUES WITH POTENTIAL FOR MANY LOCATIONS TO PICK UP 0.50 TO 1 INCH OVERNIGHT. SEEING A SLOW EXPANSION IN LIGHTNING STRIKES OVER THE MID MISSISSIPPI VALLEY AS WELL AS ELEVATED INSTABILITY INCREASES. WILL CONTINUE WITH THE ISOLATED THUNDER MENTION OVERNIGHT. SURFACE BASED CONVECTION SHOULD REMAIN TO THE WEST OF THE WABASH RIVER THROUGH DAYBREAK. POTENTIAL DOES EXIST LATE TONIGHT FOR A FEW STRONGER STORMS TO PRODUCE HAIL...ESPECIALLY OVER THE LOWER WABASH VALLEY...BUT OVERALL ANTICIPATE CONVECTION TO REMAIN SUBSEVERE THROUGH 12Z. ZONE AND GRID UPDATES OUT. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 138 PM EST SAT NOV 16 2013 OBVIOUS FOCUS FOR THE SHORT TERM WILL BE ON SEVERE WEATHER POTENTIAL ON SUNDAY AND SUNDAY EVENING AS A CLASSIC FALL SEVERE WEATHER OUTBREAK LOOKS MORE AND MORE LIKELY WITH DAMAGING WINDS THE MAIN THREAT...BUT TORNADOES CERTAINLY ARE A CONCERN AS WELL. MODELS ARE NOW IN GOOD AGREEMENT THAT PACIFIC NORTHWEST TROUGH WILL BECOME NEGATIVELY TILTED ON SUNDAY CAUSING RAPID INTENSIFICATION OF A SURFACE LOW PRESSURE SYSTEM. DEEPENING SURFACE LOW WILL LIFT TO NORTHWEST LOWER MICHIGAN OR THE NORTHERN WATERS OF LAKE MICHIGAN BY 00Z MONDAY. ASSOCIATED COLD FRONT WILL THEN SWEEP QUICKLY EAST ACROSS CENTRAL INDIANA FROM AROUND 18Z SUNDAY TO 00Z MONDAY. PRIOR TO THAT...A STALLED COLD FRONT IS EXPECTED TO RETURN NORTH AS A WARM FRONT ACROSS CENTRAL INDIANA AROUND 12-16Z SUNDAY. UPPER SPEED MAX TO AROUND 120 KNOTS AROUND THE BASE OF THE TROUGH ALONG WITH WEAKENING...BUT STILL FORMIDABLE OHIO VALLEY UPPER JET WILL PROVIDE BROAD DILUENT FLOW ON TOP OF WARM CONVEYOR BELT/60 PLUS KNOT LOW LEVEL JET AHEAD OF THE COLD FRONT. VERY STRONG WIND SHEAR /40 KNOTS OR MORE FROM 1000-700 MILLIBARS AND 60 KNOTS OR MORE FROM 1000-500 MILLIBARS/ ALONG WITH LONG CURVED HODOGRAPHS AND VERY HIGH HELICITY NUMBERS OVER 300 METERS SQUARED PER SECONDS SQUARED WILL PROVIDE AMPLE SPIN IN THE ATMOSPHERE FOR TORNADIC ACTIVITY GIVEN ENOUGH INSTABILITY. REGARDING INSTABILITY...TEMPERATURES IN THE UPPER 60S TO MID 70S WITH WARM ADVECTION ALONE...DEW POINTS APPROACHING 60 DEGREES...700-500 MILLIBAR LAPSE RATES TO 6 DEGREES CELSIUS PER KILOMETER OR MORE AND DRY INTRUSION ALOFT SHOULD RESULT IN AT LEAST SOME SURFACE INSTABILITY DESPITE EXPECTED THICK CLOUD COVER AND EARLIER OR ONGOING OVERNIGHT AND MORNING CONVECTION. EVEN THE LESS UNSTABLE...12Z DETERMINISTIC GFS IS NOW FORECASTING 500 J/KG CAPE OR MORE DURING THE AFTERNOON HOURS BUT WEAKENING SIGNIFICANTLY AFTER DARK. BASED ON THE ABOVE...AGREE WITH SPC DAY2 MODERATE RISK AND EXPECT A SEVERE WEATHER OUTBREAK SUNDAY MORNING THROUGH EARLY SUNDAY EVENING. WILL HAVE TO WATCH OUT FOR DISCRETE SUPERCELLS ESPECIALLY DURING THE MORNING NEAR THE SURFACE WARM FRONT AND AFTERNOON IN THE WARM SECTOR THEN...WITH ELONGATED FRONTOGENESIS OCCURRING NEAR THE COLD FRONT...SHOULD SEE LINEAR ACTIVITY MOVE THROUGH AROUND 18Z IN THE NORTHWEST TO 00Z IN THE SOUTHEAST ALONG AND JUST AHEAD OF THE FRONT. THIS WILL BE MORE OF A WIDESPREAD DAMAGING WIND THREAT BUT WITH ALSO THE POTENTIAL FOR A FEW BRIEF SPIN UPS IN ANY CIRCULATION COUPLET. HEAVY RAIN COULD ALSO BE AN ISSUE ESPECIALLY EARLY...BEFORE THE DRY PUNCH ALOFT MOVES IN. IT WILL ALSO CONTINUE TO BE WINDY...BUT DO NOT THINK THE HIGHER WINDS AT THE TOP OF THE BOUNDARY LAYER FROM THE BUFKIT 12Z NAM WILL BE ABLE TO MIX DOWN WITHOUT SUNSHINE. WILL CONTINUE WITH CATEGORICAL POPS PER MOS AND DROPPING DRAMATICALLY AFTER 06Z MONDAY AND ALTOGETHER AFTER 06Z. THE REST OF THE SHORT TERM WILL BE CHARACTERIZED BY DRY WEATHER WITH SLIGHTLY BELOW NORMAL TEMPERATURES AS CANADIAN HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT. MOS HIGHS IN THE UPPER 40S TO LOWER 50S MONDAY AND ALLBLEND IN THE 40S ON TUESDAY LOOK GOOD. ALSO...SHOULD SEE PLENTY OF SUNSHINE... ESPECIALLY TUESDAY AS THE HIGH PASSES OVERHEAD. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 219 PM EST SAT NOV 16 2013 MODELS CONTINUE TO HOLD ONTO HIGH PRESSURE EARLY IN THE LONG TERM PERIOD...WITH A TREND TOWARD WETTER FORECASTS LATE IN THE WEEK AND INTO THE WEEKEND. INITIALIZATION PROVIDED SLIGHT CHANCE TO LOW CHANCE POPS FROM WEDNESDAY NIGHT ONWARD...AND CANNOT REALLY ARGUE WITH IT...ALTHOUGH THE LENGTH OF TIME POPS ARE IN MAY BE A BIT OVERDONE. THIS WILL BE REFINED AS THE WEEK WEARS ON. QUASIZONAL FLOW MUCH OF THE PERIOD SUGGESTS TEMPS NEAR CLIMATOLOGY...AND INITIALIZATION HANDLED THIS WELL. && .AVIATION /DISCUSSION FOR THE 170600Z TAFS/... ISSUED AT 1130 PM EST SAT NOV 16 2013 UPPER DISTURBANCE CURRENTLY LIFTING OUT OF NORTHERN MISSOURI WITH INCREASING RAIN/EMBEDDED CONVECTION ASSOCIATED WITH IT. THIS DISTURBANCE...COUPLED WITH LIFT ALONG A STRONG LOW LEVEL JET AND A PLUME OF STEEPER MID LEVEL LAPSE RATES ADVECTING INTO THE AREA...SUGGEST FAIRLY WIDESPREAD RAIN/EMBEDDED CONVECTION SHOULD AFFECT THE TAF SITES OVERNIGHT. THIS DISTURBANCE EXPECTED TO CONTINUE PUSHING OFF TO THE NORTHEAST EARLY SUNDAY...SO RAIN/CONVECTIVE THREAT SHOULD DIMINISH AROUND SUNRISE OR SHORTLY AFTER. BRIEF PERIODS OF IFR VISIBILITY RESTRICTIONS EXPECTED WITHIN THE HEAVIER CELLS. OTHERWISE...STRONG LOW LEVEL JET OF 55-60 KTS EXPECTED TO MOVE OVERHEAD OVERNIGHT. STARTING TO SEE WIND GUSTS REACH THE SURFACE...SO DOUBTFUL THERE IS MUCH OF A CHANCE OF THE NOCTURNAL INVERSION DEVELOPING. AS A RESULT...DON/T THINK LOW LEVEL WIND SHEAR WILL REACH CRITERIA. OUTSIDE OF ANY CONVECTION...EXPECTING CEILINGS GENERALLY AROUND 020 THROUGH MIDDAY ON SUNDAY. SURFACE WIND GUSTS 25-30 KTS FROM 170-190 DEGREES EXPECTED THROUGH THE LATE MORNING...WITH MODELS SUGGEST SOME GUSTS AROUND 35 KTS TOWARDS MIDDAY. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM NOON TO 9 PM EST SUNDAY FOR INZ021-028>031- 035>049-051>057-060>065-067>072. && $$ SYNOPSIS...MK NEAR TERM...RYAN SHORT TERM...MK LONG TERM....NIELD AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS WICHITA KS
1242 PM CST SUN NOV 17 2013 .UPDATE... ISSUED AT 1226 PM CST SUN NOV 17 2013 HOISTED HIGH WIND WARNING ACROSS NORTHERN PORTION OF CWA. SURFACE OBSERVATIONS UPSTREAM CONTINUING TO DETECT WIND GUSTS FLIRTING OR EXCEEDING 50KTS. BOTH HRRR AND RUC DEPICTING NARROW CORRIDOR OF 50KT OR GREATER WINDS AFFECTING RUSSELL AND LINCOLN COUNTIES...WITH 0.5 PV FOLD TRAVERSING THE REGION BETWEEN 18-21UTC...WHICH SHOULD ENHANCE MOMENTUM TRANSPORT. HWW THREAT WILL BE ON THE LOW END ACROSS ELLSWORTH AND SALINE COUNTIES...HOWEVER GIVEN I-70 RUNS THROUGH THESE AREAS...FELT INCLUDING THEM WOULD BE PRUDENT GIVEN POTENTIAL IMPACT TO TRAFFIC. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 257 AM CST SUN NOV 17 2013 CURRENT SATELLITE WATER VAPOR IMAGERY SHOWS A VIGOROUS UPPER WAVE OVER COLORADO WHICH WILL SWEEP EASTWARD ACROSS THE CENTRAL PLAINS TODAY. DEEP ADIABATIC MIXING/STRONG DOWNWARD MOMENTUM TRANSFER BEHIND THE COLD FRONT WILL CAUSE VERY STRONG NORTHWEST WINDS TO SPREAD ACROSS MUCH OF THE AREA TODAY...THUS WILL EXPAND THE WIND ADVISORY INTO SOUTHEAST KANSAS FOR THIS AFTERNOON. ITS POSSIBLE THAT SOME LOCATIONS IN CENTRAL KANSAS AROUND I-70 CORRIDOR COULD GET VERY CLOSE TO HIGH WIND WARNING LEVELS. OTHERWISE THE WINDS SHOULD DIMINISH RAPIDLY AROUND SUNSET AS THE BOUNDARY LAYER COOLS AND STABILIZES. SURFACE HIGH PRESSURE WILL BUILD OVER THE REGION ON MONDAY THEN SLIDE EAST OF KANSAS ON TUESDAY...WITH NEAR NORMAL TEMPERATURES AND DRY WEATHER EXPECTED. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 257 AM CST SUN NOV 17 2013 THE MODEL DIFFERENCES CONTINUE BETWEEN THE GFS/ECMWF MODELS ON THE HANDLING/TIMING OF THE COLD AIR AND RESULTANT AFFECTS ON PRECIPITATION TYPE FOR THURSDAY INTO SATURDAY...HOWEVER THE SYNOPTIC PATTERN BY BOTH MODELS STILL SUGGESTS THAT THE COLD DENSE AIR COULD WIN OUT AND SURGE SOUTHWARD FOR LATE NEXT WEEK. WE WILL TREND TEMPERATURES DOWN AND CHANGE PRECIP TYPE OVER TO WINTER TYPE PRECIP SOONER. DEFINITELY A PERIOD TO KEEP AN EYE ON WITH LATER FORECAST UPDATES...SINCE ACCUMULATING SNOW COULD MATERIALIZE FOR KANSAS. JAKUB && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1226 PM CST SUN NOV 17 2013 WIND WILL BE THE MAIN AVIATION IMPACT THIS AFTERNOON. DEEP MIXING WILL RESULT IN SUSTAINED WINDS IN THE 30-35KT RANGE WITH GUSTS 35-45KTS AT KICT...KHUT AND KCNU DURING THE AFTERNOON. STRONGER WINDS EXPECTED AT KRSL AND KSLN...WHERE SUSTAINED WINDS WILL AVERAGE 40KTS WITH GUSTS 50KTS. WINDS WILL SUBSIDE AROUND SUNSET AS MIXING DIMINISHES. VFR SKIES AND VISIBILITY EXPECTED THROUGHOUT THE TAF PERIOD. SF && .FIRE WEATHER... ISSUED AT 257 AM CST SUN NOV 17 2013 THE COMBINATION OF VERY STRONG NORTHWEST WINDS AND MUCH DRIER AIR SPREADING SOUTHWARD WILL CREATE CRITICAL GRASSLAND FIRE DANGER LEVELS ACROSS CENTRAL KANSAS...AND A GOOD PORTION OF SOUTH CENTRAL KANSAS TODAY. A RED FLAG WARNING REMAINS IN EFFECT FOR TODAY AND IF ANY FIRES WERE TO DEVELOP THEY WOULD BECOME NEARLY IMPOSSIBLE TO CONTROL. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 31 58 34 60 / 0 0 0 0 HUTCHINSON 29 58 33 60 / 0 0 0 0 NEWTON 30 57 34 60 / 0 0 0 0 ELDORADO 32 58 34 59 / 0 0 0 0 WINFIELD-KWLD 32 59 35 61 / 0 0 0 0 RUSSELL 25 58 33 60 / 0 0 0 0 GREAT BEND 26 58 33 61 / 0 0 0 0 SALINA 28 58 33 60 / 0 0 0 0 MCPHERSON 29 58 33 60 / 0 0 0 0 COFFEYVILLE 34 59 34 61 / 0 0 0 10 CHANUTE 33 58 33 59 / 0 0 0 10 IOLA 33 57 33 59 / 0 0 0 10 PARSONS-KPPF 33 58 33 60 / 0 0 0 10 && .ICT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ032-033- 047>053-067>069-082-083. WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ047-050>053- 067>072-082-083-094>096. HIGH WIND WARNING UNTIL 3 PM CST THIS AFTERNOON FOR KSZ032-033- 048-049. WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ032-033-048-049. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1215 PM CST Sun Nov 17 2013 .UPDATE... Issued at 1151 AM CST SUN NOV 17 2013 The latest runs of the RAP and HRRR have been highlighting the potential for wind gusts around 50 kt for areas south and west of a line from Concordia to Topeka to Emporia. The forecast soundings show strong sinking motion in the low levels which may enhance the downward momentum transfer of winds to the surface. The low level jet is forecast to increase through the early afternoon hours directly over the area. There has already been gusts up to 53 mph in north central KS. These wind gusts will likely begin now around central KS and work eastward into east central KS during the early afternoon hours. Therefore have upgraded the wind advisory to a high wind warning. There is also the possibility that the red flag warning may need to be expanded eastward very soon given this deeper mixing in the boundary layer resulting in lower dew points. && ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 335 AM CST SUN NOV 17 2013 Latest surface analysis at 08Z had a surface low over north central Kansas along a stationary front that extended from Iowa back into southeast Colorado. Satellite imagery this morning shows the shortwave trough moving out of the Rockies. The surface low pressure is forecast to move off to the east as the upper wave moves through the Central Plains with an increasing pressure gradient behind the cold front moving across northeast Kansas. This will bring strong winds of 25 to 30 mph with gusts to around 45 mph possible from mid morning through late afternoon as forecast soundings show deep mixing today with steep low level lapse rates. These stronger winds will affect the entire forecast area and sustained winds around 30 mph will be common so will go with a wind advisory today from 10 am to 5 pm. The deep mixing will also mix down drier air and as a result minimum afternoon humidity of 20 percent or less is expected across parts of north central Kansas. The low relative humidity and critical fuels will produce very high to extreme fire danger and will continue with the Red Flag Warning for parts of north central Kansas today. Tonight the winds will be on the decrease through the early evening hours as the lower boundary layer decouples and broad surface high pressure builds into central and eastern Kansas. Lows tonight will fall into the middle 20s in north central to the mid 30s in east central Kansas. .LONG TERM...(Monday through Saturday) Issued at 335 AM CST SUN NOV 17 2013 Early week periods starting fairly quiet, but southerly winds under zonal flow aloft will bring moisture back rather quickly. Models are trending faster with a shortwave zipping though the flow, with moderate upper level potential vorticity advection and mid-level isentropic lift combining for elevated precipitation possibilities as early as Tuesday evening. Increasing lapse rates and PW values again well above normal support some mention of thunder as well. The faster timing should keep mixing up for a warmer night as well as a quicker drying trend for Wednesday. The medium range models are in agreement with increasingly amplified split flow setting up for the late week periods, but much is left be desired in agreement in the details and a low confidence forecast continues. One issue is how fast the cold air will surge in behind a northern branch wave and another is the character and speed of southern branch upper energy. At this point have the highest PoPs Thursday night and Friday with temps steadily cooling with column temps increasingly supporting snow inclusion with time. There is decent agreement with a secondary cold surge pushing precip chances to the south by the weekend. && .AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon) Issued at 1151 AM CST SUN NOV 17 2013 Have increased the wind speeds at all the taf sites due to the latest guidance suggesting higher winds moving across the area early this afternoon. The winds should diminish in the late afternoon and early evening especially after sunset. && .TOP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY until 5 PM CST this afternoon FOR KSZ008>012-024- 026-040-056-058-059. HIGH WIND WARNING until 3 PM CST this afternoon FOR KSZ020>023- 034>039-054-055. RED FLAG WARNING until 6 PM CST this evening FOR KSZ008-020>022- 034>037. && $$ UPDATE...Sanders SHORT TERM...53 LONG TERM...65 AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS PADUCAH KY
549 AM CST Sun Nov 17 2013 .SHORT TERM...(Today and Tonight) ISSUED AT 423 AM CST SUN NOV 17 2013 Will have to monitor the embedded linear segment near KPAH at 10Z closely, but it appears that the severe weather threat for early this morning may not pan out. We have had some gusts 40 to 50 MPH generally associated in or close to convective elements, and this will likely continue through at least daybreak. The current band of convection should continue to creep eastward and should be exiting the southeast around 15Z. The latest HRRR was holding onto it a bit longer til nearly 18Z, so the grids will keep likely pops through the morning in the far southeast. To the northwest of this band, little precipitation is expected until early afternoon. Previous runs of the HRRR and other mesoscale models had been generating discrete convection over the Evansville Tri State ahead of the front from midday through mid afternoon. Isolated supercell storms with the potential for all forms of severe weather including significant tornadoes would be possible with these storms if they develop. The latest few HRRR runs have not been generating the pre-frontal activity, apparently due to some minor capping developing in the wake of this mornings activity. Will keep an emphasis in the PoP fields over the Tri State area through the afternoon, but it will only be good chance to low end likelies due to the discrete nature of the storms, if they can develop. The one thing that seems to be a given in all of the models is for a broken line of most likely discrete supercell thunderstorms to develop southward along the eastward advancing cold front. This activity should enter the far northwest portions of southern Illinois around 19Z, and then continue to develop southward as the whole line moves east through the afternoon. All of the convection is expected to be east of the area by 00Z. Southeast Missouri as well as the Purchase area of west Kentucky may come through this event unscathed, as the frontal convection moves/develops southeastward from southern Illinois into the Lakes and Pennyrile region of west Kentucky late this afternoon. The full gamut of severe weather will be possible with the frontal convection, including significant tornadoes. These frontal storms may begin to coalesce into a line or at least linear segments before exiting the area. This would result in more of a bowing/damaging wind threat. As for the Wind Advisory, only the raw NAM winds are in support, but given observations this morning the Advisory looks good. Did modify the winds a bit to emphasize the northern half of the southern Illinois and the Evansville Tri State for the strongest winds. However, guidance has trended considerably lower with the winds behind the cold front, so decided to expire the Advisory at 23Z, instead of the original 02Z. High pressure will build across the area tonight. Modest west northwest winds will bring much drier and cooler air to the region. Did not stray too far from guidance for lows tonight. Generally favored the warm side of guidance for highs today. .LONG TERM...(Monday through Saturday) ISSUED AT 423 AM CST SUN NOV 17 2013 Not much overall change for the extended portion of the forecast. There is good model agreement with the synoptic features influencing the area through Thursday, then there is much divergence. Look for high pressure to finally settle over the area Monday evening, allowing for good radiational cooling overnight into Tuesday morning. Definitely undercut guidance for lows Monday night. The surface high will shift quickly east Tuesday into Tuesday night, allowing for weak return southeasterly flow across the area. As the flow aloft become southwesterly heading into Wednesday, clouds will begin to increase, and a disturbance will bring a chance of showers to the area Wednesday night into Thursday. The ECMWF continues to have a dominant northern stream system and brings Arctic surface high pressure into the area beginning late Thursday. The GFS has a stronger southern stream which effectively holds off the Arctic airmass about 24 hours later. Both models indicate a decent chance of showers Thursday night into Friday, but the temperatures would be much warmer if the GFS is right. Tremendous bust potential here. This forecast still leans a bit toward the warmer GFS solution. Both models are now clearing the area out by Saturday morning with somewhat modified Arctic high pressure building over the region. && .AVIATION... ISSUED AT 547 AM CST SUN NOV 17 2013 For the 12z Sunday WFO PAH TAF issuance, kept MVFR ceilings in place through the frontal passage at each location. For Thunderstorms, the use of vicinity thunder was kept given the variability and coverage of thunderstorm this after over each of the sites. Near term changes may be required as the frontal boundary and associated convection move through later today. Withing 1 to 3 hours of the cold frontal passage, skies were cleared out and winds/wind gusts were reduced dramatically. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...WIND ADVISORY until 5 PM CST this afternoon FOR ILZ075>078- 080>094. MO...WIND ADVISORY until 5 PM CST this afternoon FOR MOZ076-086-087- 100-107>112-114. IN...WIND ADVISORY until 5 PM CST this afternoon FOR INZ081-082- 085>088. KY...WIND ADVISORY until 5 PM CST this afternoon FOR KYZ001>022. && $$ SHORT TERM...DRS LONG TERM...DRS AVIATION...Smith
AREA FORECAST DISCUSSION
NWS PADUCAH KY
424 AM CST Sun Nov 17 2013 .SHORT TERM...(Today and Tonight) ISSUED AT 423 AM CST SUN NOV 17 2013 Will have to monitor the embedded linear segment near KPAH at 10Z closely, but it appears that the severe weather threat for early this morning may not pan out. We have had some gusts 40 to 50 MPH generally associated in or close to convective elements, and this will likely continue through at least daybreak. The current band of convection should continue to creep eastward and should be exiting the southeast around 15Z. The latest HRRR was holding onto it a bit longer til nearly 18Z, so the grids will keep likely pops through the morning in the far southeast. To the northwest of this band, little precipitation is expected until early afternoon. Previous runs of the HRRR and other mesoscale models had been generating discrete convection over the Evansville Tri State ahead of the front from midday through mid afternoon. Isolated supercell storms with the potential for all forms of severe weather including significant tornadoes would be possible with these storms if they develop. The latest few HRRR runs have not been generating the pre-frontal activity, apparently due to some minor capping developing in the wake of this mornings activity. Will keep an emphasis in the PoP fields over the Tri State area through the afternoon, but it will only be good chance to low end likelies due to the discrete nature of the storms, if they can develop. The one thing that seems to be a given in all of the models is for a broken line of most likely discrete supercell thunderstorms to develop southward along the eastward advancing cold front. This activity should enter the far northwest portions of southern Illinois around 19Z, and then continue to develop southward as the whole line moves east through the afternoon. All of the convection is expected to be east of the area by 00Z. Southeast Missouri as well as the Purchase area of west Kentucky may come through this event unscathed, as the frontal convection moves/develops southeastward from southern Illinois into the Lakes and Pennyrile region of west Kentucky late this afternoon. The full gamut of severe weather will be possible with the frontal convection, including significant tornadoes. These frontal storms may begin to coalesce into a line or at least linear segments before exiting the area. This would result in more of a bowing/damaging wind threat. As for the Wind Advisory, only the raw NAM winds are in support, but given observations this morning the Advisory looks good. Did modify the winds a bit to emphasize the northern half of the southern Illinois and the Evansville Tri State for the strongest winds. However, guidance has trended considerably lower with the winds behind the cold front, so decided to expire the Advisory at 23Z, instead of the original 02Z. High pressure will build across the area tonight. Modest west northwest winds will bring much drier and cooler air to the region. Did not stray too far from guidance for lows tonight. Generally favored the warm side of guidance for highs today. .LONG TERM...(Monday through Saturday) ISSUED AT 423 AM CST SUN NOV 17 2013 Not much overall change for the extended portion of the forecast. There is good model agreement with the synoptic features influencing the area through Thursday, then there is much divergence. Look for high pressure to finally settle over the area Monday evening, allowing for good radiational cooling overnight into Tuesday morning. Definitely undercut guidance for lows Monday night. The surface high will shift quickly east Tuesday into Tuesday night, allowing for weak return southeasterly flow across the area. As the flow aloft become southwesterly heading into Wednesday, clouds will begin to increase, and a disturbance will bring a chance of showers to the area Wednesday night into Thursday. The ECMWF continues to have a dominant northern stream system and brings Arctic surface high pressure into the area beginning late Thursday. The GFS has a stronger southern stream which effectively holds off the Arctic airmass about 24 hours later. Both models indicate a decent chance of showers Thursday night into Friday, but the temperatures would be much warmer if the GFS is right. Tremendous bust potential here. This forecast still leans a bit toward the warmer GFS solution. Both models are now clearing the area out by Saturday morning with somewhat modified Arctic high pressure building over the region. && .AVIATION... ISSUED AT 1145 PM CST SAT NOV 16 2013 Strong southerly winds will only further escalate over the next 12 to 18 hours as a vigorous storm system ejects east from the Plains. By Sunday afternoon, sustained 25 knot winds will frequently gust to 40 to 45 knots even in the absence of thunderstorms. Two time frames continue to offer the greatest potential for convection. The first unfolds overnight in response to the passage of an initial wave of energy. Numerous showers and scattered thunderstorms are expected with this first round. The second round of potentially severe thunderstorms will focus during the afternoon hours Sunday as a strong cold front plows through. MVFR ceilings and VFR visibilities will prevail through much of the period, though a reduction to MVFR or IFR conditions may occur beneath showers and thunderstorms. Winds will shift to the west as skies clear in the wake of the passing cold front Sunday evening. .. RJP .. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...WIND ADVISORY from 8 AM this morning to 5 PM CST this afternoon FOR ILZ075>078-080>094. MO...WIND ADVISORY from 8 AM this morning to 5 PM CST this afternoon FOR MOZ076-086-087-100-107>112-114. IN...WIND ADVISORY from 8 AM this morning to 5 PM CST this afternoon FOR INZ081-082-085>088. KY...WIND ADVISORY from 8 AM this morning to 5 PM CST this afternoon FOR KYZ001>022. && $$ SHORT TERM...DRS LONG TERM...DRS AVIATION...RJP
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
637 PM EST MON NOV 18 2013 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL CROSS THE AREA OVERNIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY THROUGH WEDNESDAY. HIGH PRESSURE WILL SHIFT OFFSHORE WEDNESDAY NIGHT AND WILL REMAIN ANCHORED OFF THE COAST THROUGH THURSDAY. A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY AND WILL CROSS THE REGION FRIDAY NIGHT. LOW PRESSURE WILL APPROACH FROM THE NORTHWEST ON SATURDAY AND WILL PUSH EAST THROUGH NORTHERN NEW ENGLAND SATURDAY NIGHT AND SUNDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... .UPDATE... INCREASED POPS SPATIALLY AS SHOWERS ARE NOW MOVING ACROSS SOUTHERN NH AND INTO WESTERN MAINE. HRRR HAS THIS ACTIVITY SPREADING ACROSS LEWISTON TO AUGUSTA BEFORE DISSIPATING OVER THE NEXT FEW HOURS. CLOUDS WERE ALSO ADJUSTED...ALTHOUGH LARGE SWATHS OF THE REGION IS CLEAR. THIS WILL HAVE AN IMPACT ON LOW TEMPERATURES AND WILL UPDATE ACCORDINGLY. && PREVIOUS DISCUSSION... THE UPPER TROUGH WILL CROSS THE FORECAST AREA TONIGHT...BRINGING IN SOME MID LEVEL CLOUDINESS AFTER MIDNIGHT. NORTHWEST FLOW TO STRENGTHEN...SO EXPECT UPSLOPE MOISTURE AND A FEW SCATTERED SNOW SHOWERS TO DEVELOP OVER THE NORTHWEST FACING HIGH TERRAIN. OVER SOUTHERN AREAS...DOWNSLOPE CONDITIONS WILL KEEP MAINLY CLEAR SKIES AND DRY CONDITIONS. WITH STRONG COLD AIR ADVECTION AND INCREASING GRADIENT...WINDS WILL INCREASE FURTHER AS WE APPROACH THE MORNING HOURS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... UPPER LEVEL TROUGH SHIFTS TO OUR EAST...ALLOWING WINDS TO ALIGN THROUGH A DEEP LAYER. THEREFORE...EXPECT GUSTY CONDITIONS. USED A BLEND OF MAV/MET MOS FOR DAYTIME HIGHS...BUT STILL KNOCKED THE FORECAST DOWN A COUPLE DEGREES AS THE MAV APPEARED TO HAVE A WARM BIAS. THE SURFACE RIDGE WILL BEGIN TO BUILD OVER OUR REGION LATE TUESDAY NIGHT. THIS WILL ALLOW FOR TEMPERATURES TO DROP QUICKLY...ESPECIALLY IN THE WESTERN VALLEYS OF OUR FORECAST AREA. ENOUGH DRY AIR IN PLACE TO KEEP FROM MUCH PATCHY FOG TO DEVELOP. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... QUIET START TO THE LONG TERM AS HIGH PRES BUILDS INTO THE REGION WED AND THU. SFC RIDGE AXIS SETTLES OVER THE AREA EARLY THU...WITH H8 TEMPS HOVERING RIGHT AROUND 0 C. GIVEN IDEAL RADIATIONAL COOLING CONDITIONS...HAVE UNDERCUT GUIDANCE...WITH WIDESPREAD LOW 20S...AND TEENS IN THE MTNS...EXPECTED. BY THE WEEKEND...BIG CHANGES ARE UNDERWAY AS A STRONG COLD FRONT DRIVES INTO THE CENTER OF THE CONUS. NWP IS IN GOOD AGREEMENT THAT A 1050+ MB HIGH PRES BUILDS INTO THE NRN PLAINS...DRIVING THE BAROCLINIC ZONE SWD. NRN STREAM S/WV TROF RACING OUT OF THE CANADIAN PRAIRIES THEN SETS OFF CYCLOGENESIS IN VICINITY OF THE GREAT LAKES. SFC HIGH PRES WILL BE IN THE PLACE TO THE N ON SAT. THIS SHOULD ENSURE PLENTY OF LOW LEVEL COLD AIR IS IN PLACE...WHILE WAA ALOFT WILL DRIVE THE PRODUCTION OF PRECIPITATION. THE EVOLUTION OF THE RIDGING...SFC AND ALOFT...WILL DETERMINE THE ULTIMATE PATH OF LOW PRES...BUT FOR NOW WILL SIDE WITH THE WRN SOLUTION. THIS MEANS A PERIOD OF SNOWFALL FOLLOWED BY A TRANSITION TO RAIN. THE MOUNTAINS APPEAR TO BE IN LINE FOR SOME ACCUMULATION...BEFORE ANY MIXING. IT DOES APPEAR THIS STORM SYSTEM COULD BRING THE AREA THE FIRST WIDESPREAD WINTRY PRECIPITATION. IN THE SYSTEM/S WAKE THE COLDEST AIR OF THE SEASON LOOKS SET TO ARRIVE VIA SECONDARY COLD FRONT LATE SUN. H8 TEMPS FALLING TO -15 OR COLDER ARE BEING FORECAST BY THE GFS AND ECMWF ATTM. THIS WOULD SUPPORT HIGH TEMPS STRUGGLING TO BREAK 32 DEG EARLY NEXT WEEK. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... SHORT TERM...VFR ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT...EXCEPT FOR THE HIGHER TERRAIN. LONG TERM...VFR CONDITIONS TO PREVAIL FOR MOST OF THE EXTENDED. LOW PRES APPROACHES FORM THE W LATE IN THE PERIOD...WITH AREAS OF MVFR OR LOWER DEVELOPING FROM W TO E SAT. -SN CHANGING OVER TO RA IS THE MOST LIKELY SCENARIO OUTSIDE OF THE MOUNTAINS SAT INTO SUN. && .MARINE... SHORT TERM...WINDS ARE DOWN BUT WAVES ARE STILL RUNNING ABOVE 5 FEET...SO SCAS WILL REMAIN IN PLACE. WINDS INCREASE LATER TONIGHT AS WELL TO SCA LEVELS AND CONTINUE RIGHT INTO WEDNESDAY. LONG TERM...WINDS AND SEAS REMAIN BELOW SCA THRESHOLDS INTO THE WEEKEND. LOW PRES APPROACHING FROM THE W WILL BRING WINDS AND SEAS ABOVE SCA LEVELS SAT AND ESPECIALLY SUN. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST WEDNESDAY FOR ANZ150>154. && $$ UPDATE...HANES
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
634 AM EST SUN NOV 17 2013 .SYNOPSIS... A MILD BUT WET DAY IS EXPECTED TODAY. A COLD FRONT WILL CROSS THE REGION TONIGHT AND WILL PROVIDE WIDESPREAD SHOWERS AND STORMS. COOLER AIR WILL ARRIVE ON TUESDAY AND WILL LAST THROUGH MUCH OF THE WEEK. A STRONG COLD FRONT WILL USHER IN MUCH COLDER AIR NEXT WEEKEND. && .NEAR TERM /THROUGH MONDAY NIGHT/... UPDATES TO WX AND POP GRIDS TO REFLECT ONGOING AND XPCD EVOLUTION OF SHWRS. HIGH-RESOLUTION MODELS SHOW THE SHIELD OF SHWRS PERSISTING FOR MUCH OF THE DAY OVER WRN PA AND NRN WV. CNVCTN WILL INCR IN CVRG IN FAR WRN ZONES LATE THIS AFTN AS PRIMARY SHRTWV TROF APRCHS. IF THE HRRR IS TO BE BELIEVED...CELLULAR CNVCTN CAN BE XPCD AHEAD OF THE PRIMARY CNVCTV LINE. THREATS AS OUTLINED BLW WOULD APPLY IN SUCH A CASE...SO NO SGFNT CHGS TO LATE AFTN-OVNGT PDS. PREV DISCUSSION FOLLOWS... WMFNT OVER NRN KY WILL SHARPEN AND DVLP NWD TDA IN RESPONSE TO APRCH OF VIGOROUS H5 SHRTWV TROF AND ATTENDANT DPNG SFC CYCLONE. SFC LOW WILL BE LOCATED IN GRTLKS RGN BY 18/00Z AS NEGATIVELY- TILTED UPR TROF ACCELERATES THRU THE RGN. STRONG MSTR ADVCTN IN ASSOCIATION WITH POTENT LOW-LVL JET IS UNDERWAY. SHWRS HAVE DVLPD AND WILL CONT THE LUGUBRIOUS CONDITIONS PERIODICALLY THRU THE DAY. IN BETWEEN THESE EPISODES...MODEST HEATING CAN BE XPCD...ENABLING POCKETS OF MODEST INSTBY TO FORM. CELLULAR CNVCTN XPCD TO DVLP IN THE WARM SECTOR THIS AFTN IN IL/IN/MI AS FORCING FOR ASCENT INCRS AND WIND FIELD BCMS INCRGLY ORGANIZED. BY LATE THIS AFTN...HODOGRAPHS FROM IL TO WRN PA WILL BE EXTREMELY SUPPORTIVE OF TORNADIC DVLPMT. PRIMARY LMTG FACTOR FOR SVR WX THIS AFTN IN THE FCST AREA WILL BE GENL LACK OF DP INSTBY. ANY SVR THREAT THIS AFTN WILL BE CONDITIONAL ON DVLPMT OF DP MOIST CNVCTN. ATTM...IT APPEARS PRIMARY PCPN WILL BE WEAKER SHWRS. IF MRNG PCPN CVRG IS LESS THAN ANTICIPATED... BREAKS IN CLD CVR MAY PROMOTE MORE INSTBY AND POTL FOR EARLIER ONSET OF SVR WX. MAIN FOCUS FOR SVR WX WILL BE THIS EVE AS SFC TROF/CDFNT CROSS THE RGN. VORTICITY-RICH ENVIRONMENT AMID EXTREME KINEMATICS AND INCRG FORCING FOR ASCENT WILL SUPPORT VIGOROUS LINE OF CNVCTN CAPABLE OF DMGG WIND GUSTS AND MESOVORTICES/TORNADOES. INDEED...HI-RES MODELS DEPICT A WELL-ORGANIZED CNVCTV LINE DVLPG ALONG THIS BNDRY AND IMPACTING ALL OF THE FCST AREA FROM 18/01Z-18/07Z. POCKETS OF SGFNT WIND DMG ARE ANTICIPATED ALONG THIS BNDRY...PARTICULARLY WHERE MESOVORTICES DVLP. WDSPRD HVY RAIN IS NOT ANTICIPATED IN THIS EVENT OWING TO VERY RAPID STORM MVMT. RAIN TOTALS BY MON MRNG COULD BE AS HIGH AS RAPID CLRG XPCD IN WAKE OF THE BNDRY PASSAGE. LAPSE RATES IN THE POST-FRONTAL AMS WILL STEEPEN CONSIDERABLY...PROMOTING DOWNWARD MIXING OF HIGH-MOMENTUM AIR. WIND IN THIS MIXED LYR WILL EASILY REACH 40 KT...WITH GUSTS XPCD TO APRCH OR EXCEED THIS MAGNITUDE FOR A FEW HRS AFTER FROPA. THUS...WIND ADZY WILL BE IN EFFECT AFTER FROPA THRU 12Z...WHEN GUSTINESS XPCD TO SUBSIDE. LOW-LVL WINDS WILL VEER TO WNWLY MON EVE...PROMOTING MODEST FETCH OFF LAKE ERIE COINCIDENT WITH ONSET OF SLGTLY COOLER AIR. ISOLD LAKE-EFFECT AND LAKE-ENHANCED SHWRS XPCD TO DVLP MON NGT. WITH TEMPS FALLING BLW FRZG DURG THIS TIME...VERY LGT SNOW ACCUMS WILL BE PSBL IN NRN ZONES AND ALONG WEST-FACING SLOPES/RDGS. ARRIVAL OF VERY DRY SFC AMS WILL BRING A RAPID END TO ANY PCPN LATE MON NGT. MAXIMA TDA WILL BE IN THE LOW-MID 60S...WITH LOW 50S XPCD FOR HIGHS ON MON. MINIMA WILL BE IN THE LOW-MID 40S TNGT AND UPR 20S-LWR 30S MON NGT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... WHILE CYCLONIC NORTHWESTERLY FLOW CONTINUES OVER THE AREA INTO MONDAY NIGHT AND TUESDAY...A VERY LEAN RH COLUMN LOOKS TO EXIST AND IN FACT EVEN LOW LEVEL PROFILES BECOME STRONGLY INVERTED. AS A RESULT...A DEARTH OF CLOUD COVER IS EXPECTED WITH COLD ADVECTION REALLY ONLY APPARENT AT THE SURFACE...WHILE ALOFT WARM ADVECTION WILL ALREADY BE KICKING IN. AS A RESULT...VERY STABLE AND DRY CONDITIONS MEAN CLEAR SKIES...AND WIDE DIURNAL TEMPERATURE SPREADS SEEM LIKELY TO CONTINUE THROUGH THE SHORT TERM PERIOD. FRIES && .LONG TERM /THURSDAY THROUGH SATURDAY/... RUN-TO-RUN MODEL PERFORMANCE HAS BEEN LESS THAN STELLAR IN THE EXTENDED FORECAST OVER THE PAST FEW CYCLES WITH REGARD TO THE EVOLUTION FROM WEAK RIDGING MID-WEEK TO RATHER AMPLIFIED TROUGHING BY NEXT WEEKEND OR SO. IN FACT...WHILE THE 00Z OPERATIONAL ECMWF AND GFS BOTH SHOW INCREDIBLY LITTLE SPREAD...A DEEPER LOOK AT THE GEFS MEMBERS AS WELL AS THE CANADIAN AND ITS ENSEMBLES REVEAL SAID GLOBAL GUIDANCE AGREEMENT MAY BE SERENDIPITOUS MORE THAN IT IS SKILLFUL. THAT SAID...A STRONG FASTER TREND IS NOTED IN THE OPERATIONAL GFS/ECMWF LARGELY DUE TO A MORE PRONOUNCED CUTTING OFF OF A LARGE UPPER CYCLONE OVER THE DESERT SOUTHWEST BY NEXT WEEKEND UNDER A SPRAWLING UPPER RIDGE THAT ENCOMPASSES THE EASTERN PACIFIC AND ALL OF THE INTERMOUNTAIN WEST. PREVIOUS MODEL RUNS HAD ATTEMPTED TO MAINTAIN SOME DEGREE OF UPPER LEVEL CONNECTION BETWEEN THE UPPER LOW THAT RETROGRADES TOWARD THE SOUTHWEST AND THE DEEPENING NORTHERN STREAM UPPER TROUGH AS IT DIGS INTO THE NORTHERN PLAINS. THE SOLUTIONS THAT MAINTAIN SOME UPPER LEVEL CONNECTION OR ARE SLOWER TO SEVER SAID CONNECTION RETARD THE PROGRESS OF THE UPPER TROUGH AND ASSOCIATED MUCH COLDER AIR TOWARD OUR REGION. WHILE THE SPEED AT WHICH COLD AIR ARRIVES IN THE AREA IS STILL TO BE DETERMINED...THERE IS SEEMINGLY STRONG AGREEMENT THAT A DEEP UPPER THROUGH WILL EVENTUALLY MAKES ITS WAY HERE SOMETIME BETWEEN THE WEEKEND AND START OF NEXT WEEK. AS SUCH...DRY CONDITIONS ARE LIKELY TO CONTINUE UNTIL SOUTHWESTERLY MOISTURE AND WARM ADVECTION AHEAD OF THE ATTENDANT COLD FRONT ARRIVE IN THE AREA VERY LATE THIS UPCOMING WEEKEND. POPS WERE INCREASED FRIDAY NIGHT AND SATURDAY WITH THE MOST LIKELY TIME OF THE COLD FRONTAL PASSAGE LIKELY TO BE ON SATURDAY AT THIS JUNCTURE. THAT SAID...TEMPERATURES WERE ALLOWED TO STAY ELEVATED BEFORE SATURDAY BEFORE TRANSITIONING MUCH COLDER BY SUNDAY. AN EARLY LOOK AT THE DAY 8 GUIDANCE WOULD SUGGEST HIGHS BY SUNDAY UNDER 850 MB TEMPERATURES OF -16 TO -20C OVER THE AREA WILL BE LIKELY TO REMAIN LARGELY IN THE 20S. THIS WOULD BE ROUGHLY 20 DEGREES BELOW NORMAL BY THAT TIME. AS SUCH...LAKE EFFECT SNOW SEEMS LIKELY TO RETURN TO THE FORECAST BY THAT TIME AS WELL. FRIES && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... PERIODIC SHWRS XPCD TO IMPACT ALL TERMINALS THRU THE DAY. GENL VFR/MVFR CONDS SHOULD PREDOMINATE OUTSIDE OF ANY SHWRS. WIND SHEAR REMARKS WERE INCLD IN ALL TAFS THRU MID-MRNG OWING TO PRESENCE OF STEEP INVERSION. THIS INVERSION WILL MIX OUT BY MID-MRNG...WITH GUSTY SLY WINDS XPCD ALL TERMINALS. ORGANIZED LINE OF SHWRS/TSTMS WILL MOVE THRU THE RGN TNGT IN ASSOCIATION WITH SFC TROF/CDFNT. THE LINE SHOULD ENTER PA AROUND 18/03Z AND WILL CROSS THE APLCNS BY 18/06Z. THIS LINE LKLY WILL BE ACCOMPANIED BY MDT RAIN AND BRIEF WIND GUSTS IN EXCESS OF 50-60 KT. CIGS AND VSBYS COULD BE REDUCED TO IFR OR LWR WHEN THE LINE PASSES. RAPID CLRG XPCD IN THE WAKE OF THE LINE. GUSTY WLY WINDS WILL ENSUE FOR SVRL HRS OWING TO STEEP LOW-LVL LAPSE RATES IN THE POST- FRONTAL AMS. VFR CONDS XPCD THRU MON. .OUTLOOK.../MONDAY NIGHT THROUGH THURSDAY/... VFR CONDITIONS WILL RETURN LATER TUESDAY AND CONTINUE INTO THURSDAY AS HIGH PRESSURE BUILDS OVERHEAD. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WIND ADVISORY FROM 1 AM TO 7 AM EST MONDAY FOR MDZ001. OH...WIND ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST MONDAY FOR OHZ039>041-048>050-057>059-068-069. PA...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EST MONDAY FOR PAZ007>009-013>016-020>023-029-031-073-075. WIND ADVISORY FROM 1 AM TO 7 AM EST MONDAY FOR PAZ074-076. WV...WIND ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST MONDAY FOR WVZ001>004-012. WIND ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EST MONDAY FOR WVZ021-022. WIND ADVISORY FROM 1 AM TO 7 AM EST MONDAY FOR WVZ023-041. && $$ KRAMAR/FRIES
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1246 PM EST SUN NOV 17 2013 LATEST UPDATE... MESOSCALE DISCUSSION .MESOSCALE DISCUSSION... ISSUED AT 1245 PM EST SUN NOV 17 2013 SIGNIFICANT LINE OF SEVERE STORMS HAS ALREADY EVOLVED FROM SRN WISCONSIN SOUTHWARD ACROSS ILLINOIS. ALL OF THIS ACTIVITY WILL BE MOVING RAPIDLY INTO SRN LWR MI OVER THE NEXT FEW HOURS AT A VERY HIGH RATE OF SPEED NEAR 60 MPH AND SHOULD CONGEAL INTO MORE OF A SOLID SQUALL LINE. SFC BASED INSTABILITY HAS NOT YET DEVELOPED IN SW LWR MI AND THE CURRENT ACTIVITY IS IN AN AREA OF 1500 J/KG OF SFC BASED CAPE. LATEST RAP13 GUIDANCE KEEPS OUR SFC BASED CAPES UNDER 500 J/KG THROUGH 22Z THEN JUMPS ABOVE 500 J/KG AFTER 22Z. ALTHOUGH THE INSTABILITY IN SW LWR MI WILL LIKELY BE LESS THAN UPSTREAM AS THIS EVENT UNFOLDS... THE VERY STRONG SHEAR/DYNAMICS WILL PROBABLY COMPENSATE WITH A SIGNIFICANT WIND THREAT STILL LIKELY. THE SERIOUS TORNADO THREAT HAS BEEN HIGHLIGHTED IN ALL OF THE SPC UPDATES AND STATEMENTS AND SEVERAL TORNADO WARNINGS ARE CURRENTLY IN EFFECT UPSTREAM ACROSS ILLINOIS. BOTTOM LINE... A SIGNIFICANT SEVERE WEATHER OUTBREAK IS GOING TO HAPPEN SOON IN SW LWR MI... AND THE EVENT WILL PROGRESS VERY QUICKLY. && .SYNOPSIS... ISSUED AT 326 AM EST SUN NOV 17 2013 PEOPLE IN SOUTHWEST LOWER MICHIGAN SHOULD PAY ATTENTION TO THE WEATHER TODAY BECAUSE IT LOOKS LIKE WE/RE GOING TO SEE A SIGNIFICANT WIND EVENT. A HIGH WIND WARNING IS IN EFFECT FOR ALL OF SOUTHWEST LOWER MICHIGAN FROM 4 PM THIS AFTERNOON THROUGH 4 AM MONDAY. A STRONG AUTUMN STORM WILL STRENGTHEN AS IT MOVES FROM IOWA TOWARD THE LEELANAU PENINSULA. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP TODAY AS A WARM FRONT MOVES NORTH. HOWEVER THIS AFTERNOON...STORMS WILL LIKELY BECOME STRONG TO SEVERE AS VERY STRONG DYNAMICS TAP INTO A MOISTURE RICH AIRMASS AHEAD OF THE APPROACHING COLD FRONT. WIND GUSTS IN EXCESS OF 60 MPH ARE POSSIBLE THIS AFTERNOON ALONG WITH ISOLATED TORNADOES. THE STORM PREDICTION CENTER MAINTAINS A MODERATE RISK OF SEVERE STORMS ACROSS CENTRAL LOWER MICHIGAN TODAY WITH A HIGH RISK REACHING INTO SOUTHERN LOWER MICHIGAN. MIXED RAIN/SNOW SHOWERS ARE EXPECTED MONDAY AS HIGHS FALL BACK TO THE LOWER 40S. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 326 AM EST SUN NOV 17 2013 LATEST MODEL RUNS DIDN/T CHANGE THE THINKING THAT WE/RE STARING AT A SIGNIFICANT WIND THREAT TODAY. STRONG TO SEVERE STORMS ARE POSSIBLE ESPECIALLY THIS AFTERNOON FOLLOWED BY STRONG GRADIENT WINDS BEHIND THE COLD FRONT LATE AFTERNOON AND EVENING. AS A RESULT WE ISSUED A HIGH WIND WARNING THAT/S IN EFFECT FROM 4 PM TODAY THROUGH 4 AM MONDAY. A NEGATIVELY TILTED TROUGH WILL APPROACH THE GREAT LAKES. SFC LOW PRESSURE IN THE MISSOURI VALLEY WILL MOVE TOWARD THE LEELANAU PENINSULA LATE TODAY. A WARM FRONT LIFTING NORTH WILL BE AN INITIAL FOCUS FOR CONVECTION. HOWEVER THE MAIN SHOW WILL BE THIS AFTERNOON AHEAD OF THE COLD FRONT. A LOW LEVEL JET NEAR 65 KNOTS COUPLED WITH A MID LEVEL JET NEAR 95 KNOTS WILL GENERATE SIGNIFICANT SHEAR THIS AFTERNOON. IN ADDITION THE LEFT EXIT REGION OF THE UPPER JET WILL MOVE OVER THE CWA LATE THIS AFTERNOON. IF WE CAN REALIZE CLOSE TO THE 800 J/KG MLCAPE THE MODELS INDICATE WE SHOULD HAVE MORE THAN ENOUGH FORCING AND ORGANIZATION FOR SUPERCELLS TO DEVELOP AHEAD OF THE COLD FRONT. THE STRONG SHORT WAVE MOVING IN AT THE SAME TIME WILL ONLY AID IN THE LIFT. SPC MAINTAINS A MODERATE RISK FOR SEVERE STORMS WITH A HIGH RISK JUST SOUTH OF THE CWA. CAN/T ARGUE WITH THAT. THE HRRR SHOWS A BROKEN LINE OF STORMS ARRIVING AT THE SHORE AROUND 20Z. THIS TIMING IS CONSISTENT WITH OTHER MODELS. THE MAIN SEVERE THREAT LOOKS TO BE FROM 20Z THROUGH 01Z. AFTER THE COLD FRONT SWEEPS THROUGH THE ATTENTION WILL TURN TO SYNOPTIC WINDS. THE WIND THREAT WILL CONTINUE THIS EVENING. NAM SHOWS 3 HRLY PRESSURE RISES IN THE 9-10 MB RANGE WHICH IS PRETTY HIGH AND SHOULD RESULT IN HIGH WIND WARNING TYPE WINDS...ESPECIALLY ALONG THE COAST WHERE GUSTS TO 55-65 MPH ARE POSSIBLE. STRONG COLD ADVECTION WILL HELP TO PULL DOWN THE 55 KNOTS SEEN AT 900 FEET ON BUFKIT WIND PROFILES. SURE SEEMS LIKE SCATTERED POWER OUTAGES WILL BE POSSIBLE FROM THIS AFTERNOON THROUGH TONIGHT. WINDS WILL DIMINISH LATE TONIGHT. MIXED RAIN/SNOW SHOWERS POSSIBLE MONDAY/TUESDAY AS HIGHS ONLY CLIMB INTO THE LOWER 40S. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 326 AM EST SUN NOV 17 2013 NO BIG STORMS IN THE EXTENDED. BUMPED UP MAXES A BIT ON WEDNESDAY AS EURO HAS 850 MB TEMPS AROUND 5C WHICH LOOKS REASONABLE GIVEN DEEP SOUTHERLY FLOW. ENOUGH MOISTURE MAY BE DRAWN NORTHWARD TO BRING SOME SHOWERS BY WEDNESDAY NIGHT INTO THURSDAY AS IT POOLS IN FRONT OF ADVANCING COLD FRONT. COLDER AIR FILTERS IN FOR THURSDAY NIGHT AND FRIDAY WITH PRECIP TRANSITIONING TO SNOW BY FRIDAY NIGHT. FORECAST CONFIDENCE IN THE DETAILS IS LOW WITH POOR RUN TO RUN CONSISTENCY FOR FRIDAY AND SATURDAY. THE GFS HAS A SFC LOW AND SECONDARY COLD FRONT COMING THROUGH FRIDAY WHILE THE EURO IS FURTHER NORTH AND SLOWER WITH THE LOW. SHOULD BE COLD ENOUGH FOR ALL SNOW BY FRIDAY NIGHT AND SATURDAY IN EITHER SCENARIO. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY) ISSUED AT 1200 PM EST SUN NOV 17 2013 WIDESPREAD MVFR/IFR CONDITIONS WILL CONTINUE THIS AFTERNOON. SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON WITH HIGH WIND GUSTS ALONG WITH POTENTIAL FOR HAIL AND EVEN A FEW TORNADOES. ONCE THIS MOVES THROUGH...HIGH WIND THREAT CONTINUES WITH WIDESPREAD GUSTS OVER 40 MPH AND AS HIGH AS 60 MPH DURING THE EVENING. WINDS WILL START OUT SOUTH EARLY THIS AFTERNOON...GO SOUTHWEST LATER THIS AFTERNOON AND THEN WEST LATER TONIGHT. && .MARINE... ISSUED AT 326 AM EST SUN NOV 17 2013 UPGRADED THE GALE WARNING TO A STORM WARNING. IN ADDITION TO STRONG TO SEVERE THUNDERSTORMS TODAY STRONG GRADIENT WINDS WILL DEVELOP BEHIND A COLD FRONT LATE THIS AFTERNOON. WEST STORM FORCE WINDS TO 55 KNOTS ARE EXPECTED THROUGH THE EARLY OVERNIGHT HOURS BEFORE DECREASING TO 40 KNOT GALES. WAVES WILL BUILD TO 10 TO 15 FEET TONIGHT. && .HYDROLOGY... ISSUED AT 326 AM EST SUN NOV 17 2013 HEAVY RAINFALL POSSIBLE IN STORMS TODAY...ESPECIALLY THIS AFTERNOON. LOOK FOR ADDITIONAL RAINFALL ACCUMULATIONS AROUND AN INCH THROUGH EARLY EVENING. THIS LIKELY WON`T CAUSE RIVER FLOODING. HOWEVER LOCALIZED FLOODING MAY DEVELOP IN POOR DRAINAGE AREAS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR MIZ037>040-043>046-050>052-056>059-064>067-071>074. LM...STORM WARNING UNTIL 4 AM EST MONDAY FOR LMZ844>849. && $$ MESOSCALE...MEADE SYNOPSIS...93 SHORT TERM...93 LONG TERM...OSTUNO AVIATION...LAURENS HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1200 PM EST SUN NOV 17 2013 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 326 AM EST SUN NOV 17 2013 PEOPLE IN SOUTHWEST LOWER MICHIGAN SHOULD PAY ATTENTION TO THE WEATHER TODAY BECAUSE IT LOOKS LIKE WE/RE GOING TO SEE A SIGNIFICANT WIND EVENT. A HIGH WIND WARNING IS IN EFFECT FOR ALL OF SOUTHWEST LOWER MICHIGAN FROM 4 PM THIS AFTERNOON THROUGH 4 AM MONDAY. A STRONG AUTUMN STORM WILL STRENGTHEN AS IT MOVES FROM IOWA TOWARD THE LEELANAU PENINSULA. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP TODAY AS A WARM FRONT MOVES NORTH. HOWEVER THIS AFTERNOON...STORMS WILL LIKELY BECOME STRONG TO SEVERE AS VERY STRONG DYNAMICS TAP INTO A MOISTURE RICH AIRMASS AHEAD OF THE APPROACHING COLD FRONT. WIND GUSTS IN EXCESS OF 60 MPH ARE POSSIBLE THIS AFTERNOON ALONG WITH ISOLATED TORNADOES. THE STORM PREDICTION CENTER MAINTAINS A MODERATE RISK OF SEVERE STORMS ACROSS CENTRAL LOWER MICHIGAN TODAY WITH A HIGH RISK REACHING INTO SOUTHERN LOWER MICHIGAN. MIXED RAIN/SNOW SHOWERS ARE EXPECTED MONDAY AS HIGHS FALL BACK TO THE LOWER 40S. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 326 AM EST SUN NOV 17 2013 LATEST MODEL RUNS DIDN/T CHANGE THE THINKING THAT WE/RE STARING AT A SIGNIFICANT WIND THREAT TODAY. STRONG TO SEVERE STORMS ARE POSSIBLE ESPECIALLY THIS AFTERNOON FOLLOWED BY STRONG GRADIENT WINDS BEHIND THE COLD FRONT LATE AFTERNOON AND EVENING. AS A RESULT WE ISSUED A HIGH WIND WARNING THAT/S IN EFFECT FROM 4 PM TODAY THROUGH 4 AM MONDAY. A NEGATIVELY TILTED TROUGH WILL APPROACH THE GREAT LAKES. SFC LOW PRESSURE IN THE MISSOURI VALLEY WILL MOVE TOWARD THE LEELANAU PENINSULA LATE TODAY. A WARM FRONT LIFTING NORTH WILL BE AN INITIAL FOCUS FOR CONVECTION. HOWEVER THE MAIN SHOW WILL BE THIS AFTERNOON AHEAD OF THE COLD FRONT. A LOW LEVEL JET NEAR 65 KNOTS COUPLED WITH A MID LEVEL JET NEAR 95 KNOTS WILL GENERATE SIGNIFICANT SHEAR THIS AFTERNOON. IN ADDITION THE LEFT EXIT REGION OF THE UPPER JET WILL MOVE OVER THE CWA LATE THIS AFTERNOON. IF WE CAN REALIZE CLOSE TO THE 800 J/KG MLCAPE THE MODELS INDICATE WE SHOULD HAVE MORE THAN ENOUGH FORCING AND ORGANIZATION FOR SUPERCELLS TO DEVELOP AHEAD OF THE COLD FRONT. THE STRONG SHORT WAVE MOVING IN AT THE SAME TIME WILL ONLY AID IN THE LIFT. SPC MAINTAINS A MODERATE RISK FOR SEVERE STORMS WITH A HIGH RISK JUST SOUTH OF THE CWA. CAN/T ARGUE WITH THAT. THE HRRR SHOWS A BROKEN LINE OF STORMS ARRIVING AT THE SHORE AROUND 20Z. THIS TIMING IS CONSISTENT WITH OTHER MODELS. THE MAIN SEVERE THREAT LOOKS TO BE FROM 20Z THROUGH 01Z. AFTER THE COLD FRONT SWEEPS THROUGH THE ATTENTION WILL TURN TO SYNOPTIC WINDS. THE WIND THREAT WILL CONTINUE THIS EVENING. NAM SHOWS 3 HRLY PRESSURE RISES IN THE 9-10 MB RANGE WHICH IS PRETTY HIGH AND SHOULD RESULT IN HIGH WIND WARNING TYPE WINDS...ESPECIALLY ALONG THE COAST WHERE GUSTS TO 55-65 MPH ARE POSSIBLE. STRONG COLD ADVECTION WILL HELP TO PULL DOWN THE 55 KNOTS SEEN AT 900 FEET ON BUFKIT WIND PROFILES. SURE SEEMS LIKE SCATTERED POWER OUTAGES WILL BE POSSIBLE FROM THIS AFTERNOON THROUGH TONIGHT. WINDS WILL DIMINISH LATE TONIGHT. MIXED RAIN/SNOW SHOWERS POSSIBLE MONDAY/TUESDAY AS HIGHS ONLY CLIMB INTO THE LOWER 40S. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 326 AM EST SUN NOV 17 2013 NO BIG STORMS IN THE EXTENDED. BUMPED UP MAXES A BIT ON WEDNESDAY AS EURO HAS 850 MB TEMPS AROUND 5C WHICH LOOKS REASONABLE GIVEN DEEP SOUTHERLY FLOW. ENOUGH MOISTURE MAY BE DRAWN NORTHWARD TO BRING SOME SHOWERS BY WEDNESDAY NIGHT INTO THURSDAY AS IT POOLS IN FRONT OF ADVANCING COLD FRONT. COLDER AIR FILTERS IN FOR THURSDAY NIGHT AND FRIDAY WITH PRECIP TRANSITIONING TO SNOW BY FRIDAY NIGHT. FORECAST CONFIDENCE IN THE DETAILS IS LOW WITH POOR RUN TO RUN CONSISTENCY FOR FRIDAY AND SATURDAY. THE GFS HAS A SFC LOW AND SECONDARY COLD FRONT COMING THROUGH FRIDAY WHILE THE EURO IS FURTHER NORTH AND SLOWER WITH THE LOW. SHOULD BE COLD ENOUGH FOR ALL SNOW BY FRIDAY NIGHT AND SATURDAY IN EITHER SCENARIO. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY) ISSUED AT 1200 PM EST SUN NOV 17 2013 WIDESPREAD MVFR/IFR CONDITIONS WILL CONTINUE THIS AFTERNOON. SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON WITH HIGH WIND GUSTS ALONG WITH POTENTIAL FOR HAIL AND EVEN A FEW TORNADOES. ONCE THIS MOVES THROUGH...HIGH WIND THREAT CONTINUES WITH WIDESPREAD GUSTS OVER 40 MPH AND AS HIGH AS 60 MPH DURING THE EVENING. WINDS WILL START OUT SOUTH EARLY THIS AFTERNOON...GO SOUTHWEST LATER THIS AFTERNOON AND THEN WEST LATER TONIGHT. && .MARINE... ISSUED AT 326 AM EST SUN NOV 17 2013 UPGRADED THE GALE WARNING TO A STORM WARNING. IN ADDITION TO STRONG TO SEVERE THUNDERSTORMS TODAY STRONG GRADIENT WINDS WILL DEVELOP BEHIND A COLD FRONT LATE THIS AFTERNOON. WEST STORM FORCE WINDS TO 55 KNOTS ARE EXPECTED THROUGH THE EARLY OVERNIGHT HOURS BEFORE DECREASING TO 40 KNOT GALES. WAVES WILL BUILD TO 10 TO 15 FEET TONIGHT. && .HYDROLOGY... ISSUED AT 326 AM EST SUN NOV 17 2013 HEAVY RAINFALL POSSIBLE IN STORMS TODAY...ESPECIALLY THIS AFTERNOON. LOOK FOR ADDITIONAL RAINFALL ACCUMULATIONS AROUND AN INCH THROUGH EARLY EVENING. THIS LIKELY WON`T CAUSE RIVER FLOODING. HOWEVER LOCALIZED FLOODING MAY DEVELOP IN POOR DRAINAGE AREAS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR MIZ037>040-043>046-050>052-056>059-064>067-071>074. LM...STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR LMZ844>849. GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ844>849. && $$ SYNOPSIS...93 SHORT TERM...93 LONG TERM...OSTUNO AVIATION...LAURENS HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
655 AM EST SUN NOV 17 2013 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 326 AM EST SUN NOV 17 2013 PEOPLE IN SOUTHWEST LOWER MICHIGAN SHOULD PAY ATTENTION TO THE WEATHER TODAY BECAUSE IT LOOKS LIKE WE/RE GOING TO SEE A SIGNIFICANT WIND EVENT. A HIGH WIND WARNING IS IN EFFECT FOR ALL OF SOUTHWEST LOWER MICHIGAN FROM 4 PM THIS AFTERNOON THROUGH 4 AM MONDAY. A STRONG AUTUMN STORM WILL STRENGTHEN AS IT MOVES FROM IOWA TOWARD THE LEELANAU PENINSULA. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP TODAY AS A WARM FRONT MOVES NORTH. HOWEVER THIS AFTERNOON...STORMS WILL LIKELY BECOME STRONG TO SEVERE AS VERY STRONG DYNAMICS TAP INTO A MOISTURE RICH AIRMASS AHEAD OF THE APPROACHING COLD FRONT. WIND GUSTS IN EXCESS OF 60 MPH ARE POSSIBLE THIS AFTERNOON ALONG WITH ISOLATED TORNADOES. THE STORM PREDICTION CENTER MAINTAINS A MODERATE RISK OF SEVERE STORMS ACROSS CENTRAL LOWER MICHIGAN TODAY WITH A HIGH RISK REACHING INTO SOUTHERN LOWER MICHIGAN. MIXED RAIN/SNOW SHOWERS ARE EXPECTED MONDAY AS HIGHS FALL BACK TO THE LOWER 40S. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 326 AM EST SUN NOV 17 2013 LATEST MODEL RUNS DIDN/T CHANGE THE THINKING THAT WE/RE STARING AT A SIGNIFICANT WIND THREAT TODAY. STRONG TO SEVERE STORMS ARE POSSIBLE ESPECIALLY THIS AFTERNOON FOLLOWED BY STRONG GRADIENT WINDS BEHIND THE COLD FRONT LATE AFTERNOON AND EVENING. AS A RESULT WE ISSUED A HIGH WIND WARNING THAT/S IN EFFECT FROM 4 PM TODAY THROUGH 4 AM MONDAY. A NEGATIVELY TILTED TROUGH WILL APPROACH THE GREAT LAKES. SFC LOW PRESSURE IN THE MISSOURI VALLEY WILL MOVE TOWARD THE LEELANAU PENINSULA LATE TODAY. A WARM FRONT LIFTING NORTH WILL BE AN INITIAL FOCUS FOR CONVECTION. HOWEVER THE MAIN SHOW WILL BE THIS AFTERNOON AHEAD OF THE COLD FRONT. A LOW LEVEL JET NEAR 65 KNOTS COUPLED WITH A MID LEVEL JET NEAR 95 KNOTS WILL GENERATE SIGNIFICANT SHEAR THIS AFTERNOON. IN ADDITION THE LEFT EXIT REGION OF THE UPPER JET WILL MOVE OVER THE CWA LATE THIS AFTERNOON. IF WE CAN REALIZE CLOSE TO THE 800 J/KG MLCAPE THE MODELS INDICATE WE SHOULD HAVE MORE THAN ENOUGH FORCING AND ORGANIZATION FOR SUPERCELLS TO DEVELOP AHEAD OF THE COLD FRONT. THE STRONG SHORT WAVE MOVING IN AT THE SAME TIME WILL ONLY AID IN THE LIFT. SPC MAINTAINS A MODERATE RISK FOR SEVERE STORMS WITH A HIGH RISK JUST SOUTH OF THE CWA. CAN/T ARGUE WITH THAT. THE HRRR SHOWS A BROKEN LINE OF STORMS ARRIVING AT THE SHORE AROUND 20Z. THIS TIMING IS CONSISTENT WITH OTHER MODELS. THE MAIN SEVERE THREAT LOOKS TO BE FROM 20Z THROUGH 01Z. AFTER THE COLD FRONT SWEEPS THROUGH THE ATTENTION WILL TURN TO SYNOPTIC WINDS. THE WIND THREAT WILL CONTINUE THIS EVENING. NAM SHOWS 3 HRLY PRESSURE RISES IN THE 9-10 MB RANGE WHICH IS PRETTY HIGH AND SHOULD RESULT IN HIGH WIND WARNING TYPE WINDS...ESPECIALLY ALONG THE COAST WHERE GUSTS TO 55-65 MPH ARE POSSIBLE. STRONG COLD ADVECTION WILL HELP TO PULL DOWN THE 55 KNOTS SEEN AT 900 FEET ON BUFKIT WIND PROFILES. SURE SEEMS LIKE SCATTERED POWER OUTAGES WILL BE POSSIBLE FROM THIS AFTERNOON THROUGH TONIGHT. WINDS WILL DIMINISH LATE TONIGHT. MIXED RAIN/SNOW SHOWERS POSSIBLE MONDAY/TUESDAY AS HIGHS ONLY CLIMB INTO THE LOWER 40S. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 326 AM EST SUN NOV 17 2013 NO BIG STORMS IN THE EXTENDED. BUMPED UP MAXES A BIT ON WEDNESDAY AS EURO HAS 850 MB TEMPS AROUND 5C WHICH LOOKS REASONABLE GIVEN DEEP SOUTHERLY FLOW. ENOUGH MOISTURE MAY BE DRAWN NORTHWARD TO BRING SOME SHOWERS BY WEDNESDAY NIGHT INTO THURSDAY AS IT POOLS IN FRONT OF ADVANCING COLD FRONT. COLDER AIR FILTERS IN FOR THURSDAY NIGHT AND FRIDAY WITH PRECIP TRANSITIONING TO SNOW BY FRIDAY NIGHT. FORECAST CONFIDENCE IN THE DETAILS IS LOW WITH POOR RUN TO RUN CONSISTENCY FOR FRIDAY AND SATURDAY. THE GFS HAS A SFC LOW AND SECONDARY COLD FRONT COMING THROUGH FRIDAY WHILE THE EURO IS FURTHER NORTH AND SLOWER WITH THE LOW. SHOULD BE COLD ENOUGH FOR ALL SNOW BY FRIDAY NIGHT AND SATURDAY IN EITHER SCENARIO. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 655 AM EST SUN NOV 17 2013 WIDESPREAD MVFR AND PATCHY IFR CONDITIONS THIS MORNING IN ADVANCE OF A SQUALL LINE EXPECTED TO MOVE THROUGH FROM WEST TO EAST BETWEEN 19Z TO 22Z. WIND GUSTS WITH THE SQUALL LINE COULD BE IN EXCESS OF 50 KNOTS ALONG WITH THE POTENTIAL FOR LARGE HAIL AND TORNADOES. ONCE THIS MOVES THROUGH...HIGH WIND THREAT CONTINUES WITH WIDESPREAD GUSTS OVER 40 MPH AND AS HIGH AS 60 MPH DURING THE EVENING. WINDS WILL START OUT SOUTH THIS MORNING...GO SOUTHWEST THIS AFTERNOON AND THEN WEST LATER TONIGHT. && .MARINE... ISSUED AT 326 AM EST SUN NOV 17 2013 UPGRADED THE GALE WARNING TO A STORM WARNING. IN ADDITION TO STRONG TO SEVERE THUNDERSTORMS TODAY STRONG GRADIENT WINDS WILL DEVELOP BEHIND A COLD FRONT LATE THIS AFTERNOON. WEST STORM FORCE WINDS TO 55 KNOTS ARE EXPECTED THROUGH THE EARLY OVERNIGHT HOURS BEFORE DECREASING TO 40 KNOT GALES. WAVES WILL BUILD TO 10 TO 15 FEET TONIGHT. && .HYDROLOGY... ISSUED AT 326 AM EST SUN NOV 17 2013 HEAVY RAINFALL POSSIBLE IN STORMS TODAY...ESPECIALLY THIS AFTERNOON. LOOK FOR ADDITIONAL RAINFALL ACCUMULATIONS AROUND AN INCH THROUGH EARLY EVENING. THIS LIKELY WON`T CAUSE RIVER FLOODING. HOWEVER LOCALIZED FLOODING MAY DEVELOP IN POOR DRAINAGE AREAS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR MIZ037>040-043>046-050>052-056>059-064>067-071>074. LM...STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR LMZ844>849. GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ844>849. && $$ SYNOPSIS...93 SHORT TERM...93 LONG TERM...OSTUNO AVIATION...OSTUNO HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
326 AM EST SUN NOV 17 2013 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE .SYNOPSIS... ISSUED AT 326 AM EST SUN NOV 17 2013 PEOPLE IN SOUTHWEST LOWER MICHIGAN SHOULD PAY ATTENTION TO THE WEATHER TODAY BECAUSE IT LOOKS LIKE WE/RE GOING TO SEE A SIGNIFICANT WIND EVENT. A HIGH WIND WARNING IS IN EFFECT FOR ALL OF SOUTHWEST LOWER MICHIGAN FROM 4 PM THIS AFTERNOON THROUGH 4 AM MONDAY. A STRONG AUTUMN STORM WILL MOVE STRENGTHEN AS IT MOVES FROM IOWA TOWARD THE LEELANAU PENINSULA. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP TODAY AS A WARM FRONT MOVES NORTH. HOWEVER THIS AFTERNOON...STORMS WILL LIKELY BECOME STRONG TO SEVERE AS VERY STRONG DYNAMICS TAP INTO A MOISTURE RICH AIRMASS AHEAD OF THE APPROACHING COLD FRONT. WIND GUSTS IN EXCESS OF 60 MPH ARE POSSIBLE THIS AFTERNOON ALONG WITH ISOLATED TORNADOES. THE STORM PREDICTION CENTER MAINTAINS A MODERATE RISK OF SEVERE STORMS ACROSS SOUTHWEST LOWER MICHIGAN TODAY WITH A HIGH RISK JUST TO THE SOUTH. MIXED RAIN/SNOW SHOWERS ARE EXPECTED MONDAY AS HIGHS FALL BACK TO THE LOWER 40S. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 326 AM EST SUN NOV 17 2013 LATEST MODEL RUNS DIDN/T CHANGE THE THINKING THAT WE/RE STARING AT A SIGNIFICANT WIND THREAT TODAY. STRONG TO SEVERE STORMS ARE POSSIBLE ESPECIALLY THIS AFTERNOON FOLLOWED BY STRONG GRADIENT WINDS BEHIND THE COLD FRONT LATE AFTERNOON AND EVENING. AS A RESULT WE ISSUED A HIGH WIND WARNING THAT/S IN EFFECT FROM 4 PM TODAY THROUGH 4 AM MONDAY. A NEGATIVELY TILTED TROUGH WILL APPROACH THE GREAT LAKES. SFC LOW PRESSURE IN THE MISSOURI VALLEY WILL MOVE TOWARD THE LEELANAU PENINSULA LATE TODAY. A WARM FRONT LIFTING NORTH WILL BE AN INITIAL FOCUS FOR CONVECTION. HOWEVER THE MAIN SHOW WILL BE THIS AFTERNOON AHEAD OF THE COLD FRONT. A LOW LEVEL JET NEAR 65 KNOTS COUPLED WITH A MID LEVEL JET NEAR 95 KNOTS WILL GENERATE SIGNIFICANT SHEAR THIS AFTERNOON. IN ADDITION THE LEFT EXIT REGION OF THE UPPER JET WILL MOVE OVER THE CWA LATE THIS AFTERNOON. IF WE CAN REALIZE CLOSE TO THE 800 J/KG MLCAPE THE MODELS INDICATE WE SHOULD HAVE MORE THAN ENOUGH FORCING AND ORGANIZATION FOR SUPERCELLS TO DEVELOP AHEAD OF THE COLD FRONT. THE STRONG SHORT WAVE MOVING IN AT THE SAME TIME WILL ONLY AID IN THE LIFT. SPC MAINTAINS A MODERATE RISK FOR SEVERE STORMS WITH A HIGH RISK JUST SOUTH OF THE CWA. CAN/T ARGUE WITH THAT. THE HRRR SHOWS A BROKEN LINE OF STORMS ARRIVING AT THE SHORE AROUND 20Z. THIS TIMING IS CONSISTENT WITH OTHER MODELS. THE MAIN SEVERE THREAT LOOKS TO BE FROM 20Z THROUGH 01Z. AFTER THE COLD FRONT SWEEPS THROUGH THE ATTENTION WILL TURN TO SYNOPTIC WINDS. THE WIND THREAT WILL CONTINUE THIS EVENING. NAM SHOWS 3 HRLY PRESSURE RISES IN THE 9-10 MB RANGE WHICH IS PRETTY HIGH AND SHOULD RESULT IN HIGH WIND WARNING TYPE WINDS...ESPECIALLY ALONG THE COAST WHERE GUSTS TO 55-65 MPH ARE POSSIBLE. STRONG COLD ADVECTION WILL HELP TO PULL DOWN THE 55 KNOTS SEEN AT 900 FEET ON BUFKIT WIND PROFILES. SURE SEEMS LIKE SCATTERED POWER OUTAGES WILL BE POSSIBLE FROM THIS AFTERNOON THROUGH TONIGHT. WINDS WILL DIMINISH LATE TONIGHT. MIXED RAIN/SNOW SHOWERS POSSIBLE MONDAY/TUESDAY AS HIGHS ONLY CLIMB INTO THE LOWER 40S. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 326 AM EST SUN NOV 17 2013 NO BIG STORMS IN THE EXTENDED. BUMPED UP MAXES A BIT ON WEDNESDAY AS EURO HAS 850 MB TEMPS AROUND 5C WHICH LOOKS REASONABLE GIVEN DEEP SOUTHERLY FLOW. ENOUGH MOISTURE MAY BE DRAWN NORTHWARD TO BRING SOME SHOWERS BY WEDNESDAY NIGHT INTO THURSDAY AS IT POOLS IN FRONT OF ADVANCING COLD FRONT. COLDER AIR FILTERS IN FOR THURSDAY NIGHT AND FRIDAY WITH PRECIP TRANSITIONING TO SNOW BY FRIDAY NIGHT. FORECAST CONFIDENCE IN THE DETAILS IS LOW WITH POOR RUN TO RUN CONSISTENCY FOR FRIDAY AND SATURDAY. THE GFS HAS A SFC LOW AND SECONDARY COLD FRONT COMING THROUGH FRIDAY WHILE THE EURO IS FURTHER NORTH AND SLOWER WITH THE LOW. SHOULD BE COLD ENOUGH FOR ALL SNOW BY FRIDAY NIGHT AND SATURDAY IN EITHER SCENARIO. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1149 PM EST SAT NOV 16 2013 INITIAL BATCH OF SHOWER PUSHING THROUGH THE REGION AT THIS TIME WITH WIDESPREAD MVFR AND SOME IFR STARTING TO SHOW UP. THE TREND WILL BE MORE IFR THROUGH THE NIGHT...THE WILL PERSIST FOR MUCH OF SUNDAY. THUNDERSTORMS WILL BECOME MORE LIKELY LATE TONIGHT AND INTO SUNDAY AS THE ATMOSPHERE DESTABILIZES. THE COLD FRONT PUSHES THROUGH LATER SUNDAY SENDING THE STORMS OFF TO THE EAST OF KLAN BY 00Z. WINDS WILL GUSTS WELL OVER 25 KNOTS AT TIMES SUNDAY AND ESPECIALLY SUNDAY NIGHT. GUSTS OF 40 KNOTS APPEAR LIKELY ACCOMPANYING THE STORMS AND ALSO BEHIND THE COLD FRONT FOR SUNDAY EVENING. && .MARINE... ISSUED AT 326 AM EST SUN NOV 17 2013 UPGRADED THE GALE WARNING TO A STORM WARNING. IN ADDITION TO STRONG TO SEVERE THUNDERSTORMS TODAY STRONG GRADIENT WINDS WILL DEVELOP BEHIND A COLD FRONT LATE THIS AFTERNOON. WEST STORM FORCE WINDS TO 55 KNOTS ARE EXPECTED THROUGH THE EARLY OVERNIGHT HOURS BEFORE DECREASING TO 40 KNOT GALES. WAVES WILL BUILD TO 10 TO 15 FEET TONIGHT. && .HYDROLOGY... ISSUED AT 326 AM EST SUN NOV 17 2013 HEAVY RAINFALL POSSIBLE IN STORMS TODAY...ESPECIALLY THIS AFTERNOON. LOOK FOR ADDITIONAL RAINFALL ACCUMULATIONS AROUND AN INCH THROUGH EARLY EVENING. THIS LIKELY WON`T CAUSE RIVER FLOODING. HOWEVER LOCALIZED FLOODING MAY DEVELOP IN POOR DRAINAGE AREAS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR MIZ037>040-043>046-050>052-056>059-064>067-071>074. LM...STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR LMZ844>849. GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ844>849. && $$ SYNOPSIS...93 SHORT TERM...93 LONG TERM...OSTUNO AVIATION...MJS HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
624 AM CST SUN NOV 17 2013 .UPDATE...FOR 12Z AVIATION DISCUSSION BELOW && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM CST SUN NOV 17 2013 THE SURFACE LOW HAD ENTERED NORTHEASTERN MN BY 09Z THIS MORNING. FOG AND STRATUS CLOUDS ON THE WEST/SOUTHWEST PERIPHERY OF THE LOW PLAGUED NORTH CENTRAL INTO WEST CENTRAL MN OVERNIGHT. AS THE LOW MEANDERS NORTH AND EAST THIS MORNING...NORTHWEST WINDS WILL STRENGTHEN. SHOULD SEE FOG IMPROVE DURING THE MID TO LATE MORNING...BUT CYCLONIC FLOW WILL LIKELY BE CONDUCIVE TO PROLONGED LOW CLOUD COVER...WITH THE EXCEPTION OF WEST AND SOUTH CENTRAL MN WHERE SOME AFTERNOON BREAKS ARE POSSIBLE. THE EXTENSIVE CLOUD COVER AND COLD AIR ADVECTION TODAY WILL RESULT IN LIMITED DIURNAL WARMING...WITH HIGH TEMPERATURES IN THE 40S. PRECIPITATION IS EXPECTED TO STAY CONFINED TO THE FAR SOUTHERN/SOUTHEASTERN PORTION OF THE FORECAST AREA /SOUTH CENTRAL MN NORTHEAST TO NEAR EAU CLAIRE WI/ DURING THE DAYTIME HOURS. ADDITIONAL RAINFALL AMOUNTS SHOULD MAX OUT AROUND ONE TENTH OF AN INCH OR LESS. A VERY BRIEF PERIOD OF SNOW WILL BE POSSIBLE IN THE NORTHEAST NEAR LADYSMITH TONIGHT...BUT THE PRECIP IS EXPECTED TO PRETTY MUCH BE FINISHED BY THE TIME IT TRANSITIONS TO SNOW. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 410 AM CST SUN NOV 17 2013 RELATIVELY QUIET WEATHER IS EXPECTED FOR THE UPCOMING WEEK ONCE THIS POWERFUL CYCLONE EXITS THE REGION. THE MAIN CONCERN IS TRYING TO TIME THE COLD FRONT THAT WILL MOVE THROUGH AND WEDNESDAY...AND ANY ASSOCIATED PRECIP THAT MAY ACCOMPANY IT. AT THE START OF THE PERIOD HIGH PRESSURE WILL BE BUILDING ACROSS THE UPPER MIDWEST...AND THE LARGE SCALE SUBSIDENCE RESPONSIBLE FOR THIS SURFACE HIGH WILL KEEP THE REGION DRY. AS THIS HIGH SLIDES EASTWARD WARM AIR ADVECTION WILL OVERSPREAD THE WEST LATE MONDAY INTO TUESDAY NIGHT. FORECAST SOUNDINGS FOR TUESDAY OFF THE GFS SHOW SOUTHERLY WINDS OF 20KTS THROUGHOUT THE MIXED LAYER WITH ONLY A FEW HIGH CLOUDS POSSIBLE. THIS SHOULD RESULT IN AFTERNOON TEMPERATURES SIMILAR TO THE PAST COUPLE OF DAYS...SO RAISED TEMPERATURES ABOVE GUIDANCE WITH MID 50S ON THE LEE SIDE OF THE BUFFALO RIDGE...TAPERING TO UPPER 40S ACROSS THE NORTHERN PORTION OF THE CWA. CONFIDENCE BEYOND THIS PERIOD IS LOW. ON TUESDAY NIGHT AN UPPER LEVEL TROUGH WILL MOVE ACROSS SOUTHERN CANADA AND CAUSE A SURFACE LOW TO DEVELOP...WITH A TRAILING COLD FRONT FORECAST TO MOVE THROUGH THE REGION ON WEDNESDAY. THE GEM AND ECMWF ARE FASTER WITH THIS FRONT THAN THE GFS. ALSO THE ECMWF HAS POST FRONTAL PRECIP DRIVEN BY THE MID LEVEL FGEN...WHEREAS THE GFS KEEPS THE PRECIP CONFINED TO THE DAKOTAS. HAVE DECIDED TO KEEP POPS FOR WEDNESDAY NIGHT THROUGH FRIDAY DUE TO THE HIGH UNCERTAINTY IN THE FORECAST. AS MENTIONED EARLIER...THE POLAR JET WILL BE OVER SOUTHERN CANADA...WHILE THE SOUTHERN STREAM DIGS A TROUGH OVER THE DESERT SOUTHWEST. HOW THESE TWO FEATURES PHASE ACROSS THE MIDWEST WILL DETERMINE IF SIGNIFICANT SNOW DEVELOPS TOWARD THE END OF THE WEEK...AS INDICATED BY THE GFS AND GEM...OR IF THE COLD ARCTIC HIGH PRESSURE KEEPS THE REGION DRY AND COOL. FOR NOW DID NOT HAVE THE CONFIDENCE TO LEAN TOWARDS ANY PARTICULAR SOLUTION...SO STUCK WITH THE 20POPS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 623 AM CST SUN NOV 17 2013 STRATUS CLOUDS ASSOCIATED WITH THE AREA OF LOW PRESSURE MOVING FROM NORTHEASTERN MN TOWARD THE GREAT LAKES WILL PLAGUE THE TAF SITES THIS MORNING...WITH SUB-1000FT CIGS AND AREAS OF BR WITH MVFR VSBYS. THE RAP 0.5KM AGL CONDENSATIONAL PRESSURE DEFICIT PROG HAS BEEN REFLECTING THE ACTUAL TRENDS FAIRLY WELL...AND INDICATES A FEW BREAKS IN THE LOW CLOUDS DEVELOPING EVENTUALLY TODAY /ESPECIALLY FROM NEAR KRWF TO NEAR OR JUST SOUTH OF KMSP/...AROUND 21Z. HAVE THEREFORE INCLUDED SLIGHT IMPROVEMENTS IN CIGS FOR THIS AFTERNOON. PRECIPITATION IS EXPECTED TO FALL MOSTLY SOUTHEAST OF THE TAF SITES...ALTHOUGH LIGHT RAIN MAY SCRAPE KEAU DURING THE LATE MORNING AND EARLY AFTERNOON HOURS. WINDS WILL BECOME GUSTY FROM THE NORTHWEST...NEARING SUSTAINED SPEEDS OF 20 KTS WITH GUSTS TO 30 KTS. SUBSTANTIAL SCOURING OUT OF THE LOW CLOUDS DOES NOT APPEAR AS IF ITS GOING TO HAPPEN UNTIL LATE TONIGHT AND MONDAY MORNING. KMSP... EXPECT CIGS TO PERSIST THROUGH THE MORNING...WITH MVFR VSBYS LIKELY AS WELL. VSBYS SHOULD IMPROVE TO VFR BY 18Z...WITH SOME IMPROVEMENT IN CIGS TO MVFR EXPECTED AROUND/AFTER 18Z. VFR CONDITIONS ARE EXPECTED TO DEVELOP OVERNIGHT...WITH MOSTLY CLEAR SKIES BY DAYBREAK MONDAY. SOUTHWEST WINDS SHIFT TO 290-300 DEGREES BY 18Z AND INCREASE TO SUSTAINED 15-18KT SPEEDS WITH GUSTS TO AROUND 25 KTS. WINDS DECREASE A TAD THIS EVE...BUT ARE EXPECTED TO CONTINUE GUSTING TO NEARLY 25 KTS THROUGH MUCH OF TONIGHT. /OUTLOOK FOR KMSP/ MON...MVFR CIGS EARLY...THEN VFR. WINDS WNW AT 10G15KTS. TUE...VFR. WINDS SE AT 10-15KTS. WED...VFR WITH MVFR AND -RA LATE. WINDS SSW AT 10G15KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...LS LONG TERM...JRB AVIATION...LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1134 PM CST SAT NOV 16 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 240 PM CST SAT NOV 16 2013 FIRST WAVE OF -RA/-DZ...AND EVEN A FEW THUNDERSTORMS THAT DEVELOPED ALONG THE LEADING EDGE OF THE STRONG VERTICAL LIFT ACROSS EC/SC MN EARLIER THIS AFTN. VISIBLE SATELLITE IMAGERY THIS AFTN INDICATED THE DRIER AIR MOVING ACROSS NW IOWA WHICH WILL IMPACT FAR SOUTHERN MN THIS EVENING. SOME BREAKS IN THE CLD CVR ARE LIKELY WITH THIS AREA OF DRIER AIR...BUT HOW FAR NORTH THIS CLEARING DEVELOPS REMAINS UNCERTAIN. LATEST RAP HAS AREAS SOUTH OF HWY 212 REMAINING NEARLY SATURATED BLW 2K THRU TONIGHT. DEEP SFC LOW IN NE SD WILL SLOWLY MOVE ENE ACROSS CENTRAL MN THIS EVENING...AND THEN ACROSS NE MN BY SUNDAY MORNING. THIS WILL KEEP MOST OF CENTRAL MN IN A WEAK FLOW IN THE BOUNDARY LAYER AND THEREFORE KEEPING LOW CLDS/FOG AND OCCASIONAL DRIZZLE IN THE FORECAST. NEXT SHRTWV OF INTEREST WILL IMPACT MAINLY THE SE CWA WITH -RA SUNDAY MORNING...INTO THE EARLY AFTN. FURTHER TO THE NW...THERE REMAINS ENOUGH ENERGY TO KEEP LOW POPS OVERNIGHT...BUT WITH CAA ANY PRECIPITATION AMTS WILL REMAIN LIGHT. SOME -SN/FLURRIES ARE POSSIBLE SUNDAY AFTN BEFORE ANY LEFTOVER PRECIPITATION ENDS ACROSS CENTRAL MN...BUT NOT CONFIDENT ENOUGH TO INCLUDE IN THIS FORECAST PACKAGE. TEMPS MAY BE A BIT LOWER IN FAR SOUTHERN MN IF SKIES CLR. THE LOW CLDS/FOG AND DRIZZLE WILL KEEP THE REST OF THE CWA WITH LITTLE TEMP CHG UNTIL SUNDAY AS WINDS SHIFT TO THE W/NW AND BEGIN TO GUST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 240 PM CST SAT NOV 16 2013 DRIER AIR SHOULD FOLLOW THE FROPA QUICKLY SUNDAY NIGHT WITH CLEARING SKIES INTO MONDAY. MODELS CONTINUE TO ADVERTISE A SIDESWIPING OF THE TROUGH MONDAY BEFORE IMPRESSIVE RIDGING RETURNS TUESDAY AND WEDNESDAY. INCREASED TEMPS A DEGREE OR TWO MONDAY AND MONDAY NIGHT...BUT SEVERAL DEGREES TUESDAY AS 925 MB TEMPS OF +4C TO +8C PUSH INTO THE CWA. MIXING TO THAT LEVEL WOULD YIELD HIGHS IN THE MID/UPPER 50S OVER SOUTHERN MN AND UPPER 40S OVER WRN WI. DID NOT QUITE GO THAT HIGH YET SINCE THIS IS A RELATIVELY NEW MODEL TREND...BUT EACH OF THE LAST SEVERAL RUNS HAVE BEEN GETTING PROGRESSIVELY WARMER. MODEL CONSISTENCY HAS IMPROVED TODAY WITH A DRY COLD FRONT PROGGED TO PUSH THROUGH LATE WEDNESDAY OR WEDNESDAY NIGHT. THERMAL RIDGING IN ADVANCE OF THE FRONT WILL KEEP TEMPERATURES MILD TUESDAY NIGHT AND WEDNESDAY. A 1040 MB HIGH WILL BUILD IN BEHIND THE FRONT...BUT MODELS DIFFER A BIT WHERE THIS WILL TRACK WHICH WILL DETERMINE THE DEGREE OF COLD AIR LATE NEXT WEEK. AN INVERTED TROUGH PUSHING THROUGH THURSDAY NIGHT OR FRIDAY MAY BRING A COATING OF SNOW TO THE REGION. INTRODUCED LOW POPS FOR NOW DURING THIS PERIOD. AN INTERESTING DEVELOPMENT HAS EMERGED ON THE 12Z ECMWF AND CANADIAN FOR NEXT WEEKEND. FOLLOWING THE INVERTED TROUGH...A PROLIFIC 1050-1055MB HIGH BUILDING INTO THE NORTHERN ROCKIES/NORTHWESTERN PLAINS COULD BRING OUR FIRST SHOT AT VERY COLD TEMPERATURES. HOWEVER...THE GFS AND FIM MAINTAIN A MUCH MILDER SOLUTION WITH A WEAKER AND MORE PROGRESSIVE HIGH REMAINING IN CANADA SO CANNOT TREND TOWARD EITHER SOLUTION YET. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1058 PM CST SAT NOV 16 2013 LOW PRES SHIFTING FROM THE ERN DAKOTAS INTO N-CENTRAL MN AND IT/S ASSOCIATED MOISTURE PROFILES ARE MAKING FOR A TRICKY TAF SET TONIGHT. THE OVERALL SCHEME LOOKS TO HAVE KAXN-KSTC SOCKED IN WITH LIFR FOG AND LOW CEILINGS...WHILE THE REMAINING TAF SITES WILL REMAIN MVFR TO VFR OVERNIGHT WITH PREVAILING S TO SW WINDS. THIS AREA OF LOW PRES WILL REACH NE MN BY DAYBREAK...SPREADING THE DEGRADED CONDS INTO CENTRAL MN...POSSIBLY AFFECTING KMSP ARND 12Z. CEILINGS DROP INTO MVFR RANGE FOR MOST SITES ARND DAYBREAK...BUT THE ERN TAF SITES WILL BE MORE SUSCEPTIBLE TO NOT ONLY THE DEGRADED CONDS BUT ALSO ADDITIONAL ROUNDS OF -RA AS A SECONDARY LOW PRES CENTER EJECTS FROM THE CENTRAL PLAINS TWD NRN IA/IL. AS THIS SECONDARY LOW PRES CENTER SHIFTS E...CONDS WILL IMPROVE SUN AFTN/EVE. HOWEVER...MODELS INDICATE THAT SUBSIDENCE ON THE BACKSIDE OF THE SECONDARY LOW WITHIN STILL A FAIRLY DEEP MOISTURE COLUMN WILL RESULT IN MVFR CIGS TMRW NIGHT SO HAVE ADVERTISED AS SUCH AT ALL SITES. WINDS STILL LOOK TO TAKE A SIGNIFICANT SHIFT FROM SW TO NW DURG THE DAY TMRW AND WILL SHOW A STRONG INCRS IN SPEED...APPROACHING 20G30KT. SPEEDS WILL DECRS ONLY SLIGHTLY FOR TMRW NIGHT...MAKING 15G25KT SPEEDS COMMON SUN NIGHT INTO MON MRNG. KMSP...CONDS HAVE IMPROVED SIGNIFICANTLY OVER THE PAST 6 HOURS AND BOTH OBSERVATIONAL TRENDS AND MODELS INDICATE THE THE IMPROVEMENT WILL LAST THRU MUCH OF THE OVERNIGHT HOURS. CEILINGS DO LOOK TO DROP BACK INTO MVFR RANGE DURG THE PRE-DAWN HRS BUT IFR CONDS LOOK MUCH LESS LIKELY. CONDS DROP FURTHER ARND DAYBREAK WITH A MINOR INVERSION DEVELOPING BUT SUCH CONDITIONS WILL HAVE A SHORT DURATION AS -RA MOVES IN FROM THE SE AND HELPS SCOUR OUT LOWER VSBY AND POSSIBLY CEILINGS AS WELL. CONDS THEN CONTINUE TO IMPROVE AS THE SECONDARY LOW PRES CENTER SHIFTS AWAY...MAKING FOR STRONG/GUSTY NW WINDS AND CEILINGS EVENTUALLY REACHING VFR. HOWEVER...ANOTHER ROUND OF MVFR CEILINGS LOOKS FAIRLY LIKELY SUN NIGHT INTO MON MRNG BEHIND THE DEPARTING SYSTEM. /OUTLOOK FOR KMSP/ MON...MVFR CIGS EARLY. THEN VFR. WINDS WNW AT 10G15KTS. TUE...VFR. WINDS SE AT 10KTS. WED...VFR WITH MVFR AND -RA LATE. WINDS SSW AT 10G15KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JLT LONG TERM...BORGHOFF AVIATION...JPC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1234 PM CST SUN NOV 17 2013 .UPDATE... ISSUED AT 1233 PM CST SUN NOV 17 2013 WINDS HAVE STARTED TO INCREASE MORE THAN EXPECTED ESPECIALLY IN NORTH CENTRAL KANSAS. THE LATEST HRRR INDICATES THE STRONGEST WINDS WILL BE EARLY THIS AFTERNOON IN NORTH CENTRAL KANSAS. HAVE ISSUED A HIGH WIND WARNING FOR THIS AREA. WINDS CONTINUE TO BE GUSTY ACROSS THE REMAINDER OF THE AREA AND WILL CONTINUE THE WIND ADVISORY FOR NEBRASKA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 307 AM CST SUN NOV 17 2013 FOCUS IS ON A PERIOD OF INTENSE WINDS TODAY AND CRITICAL FIRE WEATHER CONDITIONS. SPRINKLES OR A BANDED AREA OF VERY LIGHT RAIN DEVELOPED DURING THE PRE DAWN HOURS IN PRESENCE OF MID LEVEL FRONTOGENESIS AND DYNAMICS AS A LEAD SHORTWAVE TROUGH CROSSES NEB AND A COLD FRONTAL BOUNDARY WORKS EAST/SOUTHEAST. LIFT IS FOCUSED MAINLY NORTH OF INTERSTATE 80 AND MAY LINGER JUST BEYOND 12Z IN OUR EASTERN ZONES. SFC COLD FRONT WILL CLEAR OUR CWA BY DAYBREAK WITH A STRONGER SHORTWAVE TROUGH CROSSING THE NORTHERN/CENTRAL PLAINS MID/LATE MORNING WITH A SECONDARY COLD FRONT AND COOLER AIR MAKING A PUSH SOUTHEASTWARD BY MIDDAY...AND THE MID LEVEL THERMAL TROUGH SWEEPS SOUTHEAST TOWARD THE MISSOURI RIVER BY LATE AFTN. 3HR PRESSURE RISES BEHIND THE INITIAL FRONT BY DAYBREAK AVERAGE NEAR 7MB ACROSS PORTIONS OF CENTRAL/EASTERN KANSAS...THEN AVERAGE 4 TO 6MB ACROSS CENTRAL/EASTERN NEB BEHIND SECONDARY BOUNDARY THIS AFTN. IN A TIGHT PRESSURE GRADIENT BEHIND THE BOUNDARIES...AN INTENSE PERIOD OF NORTHWEST WINDS ARE EXPECTED BEGINNING AROUND MID MORNING...PEAKING AROUND MID DAY OR EARLY AFTERNOON...THEN SUBSIDING IN THE EVENING AS THE SYSTEM DEPARTS AND GRADIENT RELAXES. MODEL FORECAST SOUNDINGS SUGGEST THE DEEPEST MIXING WILL OCCUR ACROSS OUR SOUTHERN/SOUTHWEST ZONES WHERE MIXING WILL REACH JUST ABOVE H8. WINDS AT THE TOP OF THE LAYER ARE NEAR 50KTS IN NC KANSAS AROUND MID DAY THEN DECREASE THE AROUND 35KTS BY MID/LATE AFTN. FARTHER NORTH ACROSS OUR NORTHERN ZONES MIXING IS BETWEEN H8 AND H85 WITH WINDS AT THE TOP OF THE LAYER AVERAGING 35 TO 40KTS. IN ANY CASE...VERY WINDY CONDITIONS WILL DEVELOP TODAY AND CURRENT WIND ADVISORY HEADLINE REMAINS ON TRACK. HAVE SOME CONCERNS THAT PORTIONS OF NC KANSAS TOWARDS THE RUSSEL AREA MAY NEAR OR REACH HIGH WIND WARNING CRITERIA AND THIS WILL NEED TO BE MONITORED CLOSELY. SHORT TERM MODELS INDICATE THE PRESENCE OF MID LEVEL MOISTURE ACROSS OUR NORTHEAST ZONES TODAY AND PLACE CONVECTIVE TEMPS IN THE UPPER 40S TO AROUND 50F...WHICH ARE AROUND FORECAST HIGHS FOR TODAY. CONFIDENCE IS NOT HIGH ON THE DEGREE OF CLOUD COVER IN THIS AREA...BUT DID GO WITH AT LEAST PARTLY CLOUDY CONDITIONS. AS FAR AS TEMPERATURES GO...WE WILL BE ON A DOWNWARD TREND COMPARED TO THE MILD CONDITIONS ON SATURDAY WITH HIGHS TODAY AVERAGING IN THE 50S. THE COLDER AIRMASS WILL BE MORE NOTICEABLE TONIGHT IN GOOD RADIATIONAL CONDITIONS. A SURFACE RIDGE AXIS SETTLES ONTO THE PLAINS AND WINDS DROP OFF...SKIES CLEAR AND VERY DRY DPS FM THE TEENS TO LOW 20S WILL BE IN PLACE. HAVE TARGETED LOWS FROM THE TEENS IN THE RIVER VALLEYS IN OUR WESTERN ZONES...TO THE LOW/MID 20S IN THE EAST. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 307 AM CST SUN NOV 17 2013 ALOFT: HEIGHTS WILL BE RISING MON IN THE WAKE OF THE STORM EXITING THE REGION TODAY...WITH A BROAD LOW-AMPLITUDE RIDGE ENVELOPING THE CNTRL USA. AS THE WEEK PROGRESSES...SPLIT FLOW WILL EVOLVE WITH GOOD MODEL AGREEMENT ON THE NRN STREAM /ALONG THE US-CANADA BORDER/ DELIVERING ANOTHER COLD AIR MASS TO THE REGION. MEANWHILE...A TROF WILL MOVE INTO THE DESERT SW LATE WED AND CLOSE OFF INTO A CUT-OFF LOW AS THE WAVELENGTH SHORTENS AND HIGHER LATITUDE AMPLIFICATION OCCURS. HEIGHTS WILL THEN BUILD DOWNSTREAM OVER THE SRN PLAINS AND SE...RESULTING IN CONFLUENT FLOW OVER THE ERN HALF OF THE CONUS. SURFACE: HIGH PRES WILL BE OVERHEAD AT DAWN MON. THIS HIGH WILL DEPART INTO THE ERN USA TUE. THE FCST AREA WILL BE IN THE WARM SECTOR OF LOW PRES ADVANCING E ALONG THE US-CANADA BORDER TUE. THE ASSOCIATED COLD FRONT WILL SURGE S...CROSSING THE FCST AREA WED AFTERNOON. THE CONSISTENCY OF THE PAST SEVERAL RUNS OF THE EC IS PREFERRED AND ITS ENSEMBLE MEAN IS SUPPORTIVE. THE 00Z GEM IS ALSO ON BOARD. THE 18Z/00Z GFS HAVE TRENDED FASTER VS 24 HRS AGO...BUT THEY ARE STILL LAGGING. STRONG AND COLD HIGH PRES WILL SETTLE OVER THE PLAINS THU. FRI THE HIGH WILL DEPART FOR THE GREAT LAKES AS A CLIPPER RACES ACROSS SRN CANADA. THIS SYSTEM WILL DELIVER A REINFORCING COLD SHOT AND HIGH PRES...BUT THE CORE OF THE COLDEST AIR WILL HEAD INTO THE ERN USA. THE 142 AM AND 11 AM/SAT EXTENDED FCST DISCUSSIONS FROM WPC WERE REVIEWED FOR INCLUSION INTO THE FCST AND SUPPORT THE ABOVE SCENARIOS. ENJOY THE FIRST FEW DAYS THIS WEEK BECAUSE THE EXTENDED FCST AND BEYOND IS LOOKING COLD. THE WEEK WILL START WITH MILD /WARMER THAN NORMAL/ TEMPS. THAT WILL END THU AS ARCTIC AIR SURGES S. THE EC ENSEMBLE MEAN AND CFSV2 TEMP ANOMALIES SUGGEST TEMPS THEN AVERAGE AT OR BELOW NORMAL TO FINISH OUT THE MONTH. THAT DOESN/T MEAN WE WON/T HAVE A DAY HERE OR THERE OF ABOVE NORMAL WARMTH. BUT OVERALL...THE AVERAGE SHOULD BE COLDER. OVERALL CHANCE FOR PRECIP ARE NIL UNTIL THU NIGHT OR FRI. GFS ENSEMBLE PROBABILITIES FOR .10" INCREASE TO 60+ PERCENT WITH A 40-50 PERCENT CHANCE OF .25" AND 15 PERCENT FOR .50". A LITTLE OVER HALF OF THE EC ENSEMBLE MEMBERS OFFER ANYWHERE FROM .10" TO .50". HAZARDS: FOR NOW NOTHING SPECIFIC. HOWEVER...WE CONTINUE TO SEE HINTS OF THE CUT-OFF LOW EJECTING SHORTWAVE TROFS THAT COULD RESULT IN A SOME LIGHT PRECIP OF THE WINTRY VARIETY IN THE THU-FRI TIMEFRAME. THE DAILY DETAILS... MON: A COLD/FROSTY START. SUNNY AND TEMPS WILL REBOUND NICELY. TUE: INCREASING MID-HIGH CLOUDS. BELIEVE WE HAVE THIS BETTER DEPICTED VS 24 HRS AGO. BREEZY S WINDS WILL GUST TO 25-30 MPH. WED: DRY AFTERNOON COLD FRONTAL PASSAGE. PARTLY SUNNY WITH MULTI-LAYERED MID-HIGH CLOUDS. WINDS SHOULD BE FAIRLY LIGHT UNTIL FRONTAL PASSAGE...THEN THEY SHOULD CRANK IT UP FROM THE N. THU: PROBABLY CLOUDY VIA GEM/EC/GFS CROSS SECTIONS. TEMPS MAY RISE VERY LITTLE FROM MORNING LOWS. HIGH IN THE 30S LOOK PLAUSIBLE AND ORD-GREELEY MAY NOT REACH 30F. FRI-SAT: UNCERTAIN. BUT CONFLUENT FLOW ALOFT WILL RESULT IN A VERY STRONG UPPER-LEVEL JET CORE /140 KTS/ OVER THE OH VALLEY. THIS WILL PUT US IN THE RIGHT ENTRANCE REGION. THE IMPORTANT QUESTION IS MOISTURE AND IF IT/S FAR ENOUGH N. BOTH THE GFS AND EC HAVE IT THU NIGHT AND THEN PUSH IT S OF THE FCST AREA FRI WITH THE POSSIBILITY OF IMPROVING WX SAT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1122 AM CST SUN NOV 17 2013 WINDS WILL BE THE PRIMARY CONCERN THROUGH THE AFTERNOON. EXPECT GUSTY NORTHWEST WINDS TO CONTINUE THROUGH AROUND SUNSET. WINDS WILL GRADUALLY BECOME LIGHT DURING THE NIGHT. A FEW MID LEVEL CLOUDS WILL MOVE THROUGH THIS AFTERNOON. && .FIRE WEATHER... ISSUED AT 307 AM CST SUN NOV 17 2013 A RED FLAG WARNING REMAINS IN EFFECT TODAY FOR ALL OF NORTH CENTRAL KANSAS AND LOCATIONS WEST OF A LINE FROM LEXINGTON TO FRANKLIN IN SOUTH CENTRAL NEBRASKA. INTENSE NORTHWEST WINDS ARE FORECAST TODAY IN DEEP MIXING BEHIND A COLD FRONTAL BOUNDARY. THE INTENSE WINDS WILL DEVELOP MID TO LATE MORNING AND REMAIN STRONG THIS AFTN BEFORE SUBSIDING IN THE EVENING. DRY AIRMASS ADVECTS SOUTHEAST AND LOW RELATIVE HUMIDITY VALUES WILL DROP NEAR OR BELOW 20 PERCENT IN THE RED FLAG WARNING AREA. THIS BEING SAID...LATEST MODEL RUNS HAVE TRENDED HIGHER WITH DPS/RH LEVELS ACROSS PORTIONS OF SOUTH CENTRAL NEBRASKA...NAMELY DAWSON...GOSPER AND PHELPS COUNTIES. CONDITIONS ACROSS NORTH CENTRAL KANSAS PARTICULARLY PHILLIPS AND ROOKS COUNTIES STAND TO SEE THE MOST CRITICAL FIRE DANGER CONDITIONS WHERE DPS IN THE SINGLE DIGITS ARE FORECAST...RESULTING IN LOW RELATIVE HUMIDITY VALUES AROUND 15 PERCENT. THE LOCATION OF CURRENT RED FLAG WARNING WILL REMAIN AS IS WITH A BUFFER SURROUNDING OUR FAR SW ZONES WHERE CONDITIONS WILL BE MOST CRITICAL. HOWEVER...IF TEMPS TREND UP AND LOWER DPS MATERIALIZE FARTHER EAST THAN WHAT CURRENT MODELS SHOW...THEN HEADLINE MAY NEED TO BE EXPANDED. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049- 060>064-072>077-082>087. RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ060-072-073- 082>084. KS...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ005>007- 017>019. HIGH WIND WARNING UNTIL 3 PM CST THIS AFTERNOON FOR KSZ005>007- 017>019. && $$ UPDATE...JCB SHORT TERM...FAY LONG TERM...HALBLAUB AVIATION...JCB FIRE WEATHER...FAY
AREA FORECAST DISCUSSION
NWS BUFFALO NY
729 AM EST SUN NOV 17 2013 .SYNOPSIS... LOW PRESSURE WILL RAPIDLY STRENGTHEN ACROSS THE UPPER LAKES TODAY...WHICH WILL SWEEP A POWERFUL COLD FRONT ACROSS OUR REGION TONIGHT. AHEAD OF THE FRONT WILL BE WARM TEMPERATURES AND SOME SHOWERS...WITH A LINE OF SEVERE THUNDERSTORMS POSSIBLE ALONG THE FRONT TONIGHT. THERE WILL ALSO BE GUSTY WINDS AHEAD OF THE FRONT AND MORE WIDESPREAD STRONG WINDS BEHIND THE FRONT. THE FRONT WILL EVENTUALLY USHER IN COOLER TEMPERATURES MONDAY NIGHT THROUGH TUESDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... LOW PRESSURE DEVELOPING ACROSS MINNESOTA THIS MORNING WILL RAPIDLY INTENSIFY AS IT LIFTS ACROSS THE UPPER LAKES TODAY. THE INTENSE LOW WILL CLOSE OFF ALOFT SOUTH OF HUDSON BAY AS IT SWEEPS A STRONG COLD FRONT ACROSS WESTERN NEW YORK TONIGHT. THIS WILL BRING STRONG SYNOPTIC WINDS TO SOME LOCATIONS...AND POSSIBLY SOME SEVERE WEATHER WITH THE FRONTAL PASSAGE. NOW FOR THE DETAILS... TODAY WILL GET OFF TO A WARM START...WITH MORNING TEMPERATURES ALREADY IN THE 50S IN MANY LOCATIONS. TEMPERATURES RISE INTO THE UPPER 50S ACROSS HIGHER TERRAIN AND INTO THE MID 60S IN DOWNSLOPE REGIONS NORTH OF I-90. AN AREA OF SHOWERS HAS DEVELOPED WELL AHEAD OF THE COLD FRONT IN THE OHIO VALLEY. MUCH OF THE SUPPORT FOR THESE SHOWERS IS FROM THE COMBINATION OF UPPER LEVEL LIFT AND MOISTURE ADVECTION WITH THE DEVELOPING LLJ. SHOWERS WILL GRADUALLY WEAKEN AS THE SSW FLOW LIFTS THEM AHEAD OF SYNOPTIC SUPPORT AND INTO OUR REGION THIS MORNING. THIS WILL BRING A PERIOD OF SHOWERS TO MOST THIS MORNING...BUT HIGH RESOLUTION MODEL GUIDANCE (00/06Z NAM/RGEM/HRRR) HAS BEEN FAIRLY CONSISTENT IN FORECASTING A BREAK BETWEEN THIS INITIAL ROUND AND COLD FRONT. WITH SUPPORT FROM IR SATELLITE TRENDS..EXPECT MOST AREAS WILL GET A BREAK FROM THE SHOWERS THIS AFTERNOON...WITH JUST WARM AND BREEZY CONDITIONS UNTIL THE NEXT ROUND OF SHOWERS MOVES IN FROM THE SOUTHWEST LATE AFTERNOON. WINDS WILL BE GUSTY TODAY DUE TO A 45 KNOT FLOW ALOFT. FOR THE MOST PART...THIS WILL NOT MIX DOWN TO THE SURFACE...EXCEPT ALONG THE CHAUTAUQUA RIDGE AND BLACK RIVER VALLEY WHERE GUSTS TO 40 MPH ARE LIKELY. THIS SAID...EXPECT DAMAGING WINDS TO HOLD OFF UNTIL THIS EVENING WHEN WINDS ALOFT INCREASE. NEARLY ALL LOCATIONS WILL EXPERIENCE STRONG WINDS AT SOME POINT TONIGHT. ALTHOUGH THE TRACK OF THE LOW IS A BIT NW OF THE TYPICALLY FAVORED TRACK FOR HIGH WINDS IN OUR REGION...THE SHEAR INTENSITY OF THE 970MB LOW AS IT CLOSES OFF ALOFT SUPPORTS A SIGNIFICANT WIND DAMAGE THREAT FOR OUR REGION. THE FIRST ISSUE WILL BE THE INCREASING LOW LEVEL JET OUT AHEAD OF THE FRONT...WITH BUFKIT FOR THE GFS/NAM/SREF ENSEMBLE SUPPORTING A PREFRONTAL LLJ OF 65 KTS AT 925MB. WHILE THIS IS NOT EXPECTED TO MIX TO THE SURFACE IN MOST LOCATIONS...EXPECT DAMAGING GUSTS WILL MIX OFF THE CHAUTAUQUA RIDGE AND BLACK RIVER VALLEY. BECAUSE OF THIS...THE HIGH WIND WARNING NOW ALSO INCLUDES LEWIS AND JEFFERSON COUNTIES. ELSEWHERE THE CONFIDENCE IN SYNOPTIC DAMAGING WINDS IS LOWER. THE BIG QUESTION WILL BE TO WHAT EXTENT WINDS MIX ACROSS HIGHER TERRAIN. GIVEN THE POTENTIAL FOR 60 MPH WINDS STILL EXISTS...HAVE KEPT THE HIGH WIND WATCH IN PLACE. HOWEVER...00Z/06Z GUIDANCE SEEMS TO SUGGEST MORE OF AN ADVISORY TYPE EVENT ACROSS INTERIOR SECTIONS. THIS WILL CONTINUE TO BE MONITORED...WITH FUTURE TRENDS IN THE STRENGTH OF THE LLJ KEY TO THIS HEADLINE DECISION. IN ADDITION TO SYNOPTIC WINDS...PRECIPITATION ALONG THE FRONT ITSELF MAY MIX STRONG WINDS ALOFT AND RESULT IN CONVECTIVELY DRIVEN DAMAGING WINDS. THERE ALSO MAY BE A TEMPORARY BURST IN WINDS IMMEDIATELY BEHIND THE FRONT AS A STRONG SHORTWAVE PIVOTS AROUND THE RAPIDLY DEEPENING LOW. BECAUSE OF THIS...SPC HAS WESTERN NEW YORK IN A SLIGHT RISK FOR SEVERE WEATHER...WITH DAMAGING WINDS THE MAIN THREAT. THE FRONT WILL ENTER WESTERN NEW YORK THIS EVENING...AND QUICKLY SWEEP ACROSS THE REGION DURING THE EARLY MORNING HOURS. FORECAST HEDGES ON THE FASTER SIDE OF MOST GUIDANCE...WITH THE FRONT LIKELY TO ACCELERATE SIMILAR TO THE HRRR FORECAST. SHOWERS SHOULD END QUICKLY FROM WEST TO EAST...WITH THE ATMOSPHERE BRIEFLY DRYING OUT IMMEDIATELY BEHIND THE FRONT. TEMPERATURES WILL QUICKLY COOL INTO THE 40S BEHIND THE FRONT. WINDY CONDITIONS WILL CONTINUE...WITH WEAKER WINDS ALOFT BEING OFFSET BY BETTER MIXING IN THE COLD AIR ADVECTION. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... THIS TIME PERIOD WILL TRANSITION FROM THE MILD AND POTENTIAL SEVERE/WINDY WEATHER TO MORE WINTRY. BY 12Z MONDAY THE COLD FRONT AND ITS ASSOCIATED PRECIPITATION WILL BE EAST OF THE REGION. THE SURFACE LOW...THAT NOW WILL BE ENTERING INTO AND CROSSING QUEBEC WILL CONTINUE TO DEEPEN MONDAY MORNING BENEATH A NEGATIVELY TILTED UPPER LEVEL TROUGH. WINDS AROUND THIS AREA OF LOW PRESSURE WILL BRING MUCH COLDER AIR ALOFT ACROSS OUR REGION WHICH WILL AID IN MIXING STRONGER WIND GUSTS DOWN TO THE SURFACE. ALSO A STRONG PRESSURE GRADIENT ORIGINATING FROM THIS DEEP AREA OF LOW PRESSURE IN ADDITION TO GOOD PRESSURE RISES BEHIND THE FRONT WILL CONTINUE TO BRING GUSTY TO STRONG WINDS ACROSS THE REGION. STRONGEST WINDS...ONES THAT WILL NEAR 60 MPH WILL BE FOUND DOWNWIND OF LAKE ERIE AND INLAND TOWARDS MONROE COUNTY...AND ALSO ACROSS THE NORTH COUNTRY AND THE SAINT LAWRENCE VALLEY. FARTHER INLAND ACROSS THE SOUTHERN TIER AND UPPER GENESEE VALLEY AND FINGER LAKES REGION WILL LEAVE THE HIGH WIND WATCH IN EFFECT...AS WIND GUSTS MAY REMAIN WITHIN ADVISORY LEVEL CRITERIA. BEHIND THE COLD FRONT 850 HPA TEMPERATURES WILL DROP TO AROUND -6C OVER THE LAKES MONDAY...WHICH WITH THE +8C OR SO LAKES WILL LIKELY BRING LAKE EFFECT RAIN SHOWERS THROUGH THE DAY MONDAY. WITH A STILL WSW WIND LIGHT BANDS OF RAIN WILL LIKELY BE JUST TO THE SOUTH OF BUFFALO...AND ACROSS WATERTOWN AND TOWARDS THE SAINT LAWRENCE RIVER MONDAY MORNING. AS THE COLD AIR DEEPENS AND WINDS VEER AROUND TO WEST...AND THEN NORTHWEST THESE BANDS OF LAKE EFFECT SHOWERS WILL DROP SOUTHWARD. MODEL SOUNDINGS SUGGEST THAT PRECIPITATION WILL STAY MAINLY RAIN THROUGH THE DAY...AND THEN AS THE COLDER AIR DEEPENS TO AROUND -8 TO -10C MONDAY NIGHT PRECIPITATION WILL CHANGE OVER TO LAKE EFFECT SNOW SHOWERS. ONE CONCERN FOR LATER MONDAY NIGHT IS DEPTH OF THE MOISTURE WILL BE BELOW THE GOOD SNOW CRYSTAL GROWTH ZONE. THIS MAY ALLOW FOR SOME FREEZING DRIZZLE TO DEVELOP LATER IN THE NIGHT. THIS MINIMAL MOISTURE IN THE SNOW GROWTH ZONES WILL ALSO HOLD ACCUMULATION TO THE LIGHTER SIDE MONDAY NIGHT. TUESDAY LAKE EFFECT PRECIPITATION WILL END THROUGH THE MORNING HOURS AS TEMPERATURES BEGIN TO WARM ALOFT AND HIGH PRESSURE FUNNELS SOME DRIER AIR ACROSS THE LAKES. THIS DRIER AIR WILL ALSO HELP TO ERODE THE LOW CLOUDS AND ALLOW FOR SOME SUNSHINE THROUGH THE DAY. THOUGH SOME SUNSHINE WILL DEVELOP...OUR HIGHS TUESDAY WILL ONLY REACH INTO THE MID AND UPPER 30S...WHICH WILL BE A RETURN BACK TO BELOW NORMAL TEMPERATURES. CLEARING SKIES TUESDAY NIGHT AND LIGHT WINDS SHOULD BRING WIDESPREAD 20S AT NIGHT WITH A FEW OF THE COLDER VALLEYS OF THE INLAND SOUTHERN TIER AND NORTH COUNTRY POSSIBLY DROPPING INTO THE UPPER TEENS. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... TRANQUIL WEATHER WILL CHARACTERIZE THE FIRST HALF OF THIS PERIOD AS A BROAD SURFACE RIDGE BUILDS ACROSS THE GREAT LAKES AND NORTHEAST PART OF THE COUNTRY. THE SURFACE HIGH SHOULD BRING MOSTLY SUNNY SKIES WEDNESDAY AS IT CRESTS OVER NEW YORK STATE NEW ENGLAND. AS THE HIGH SETTLES OFF THE NEW ENGLAND COAST THURSDAY...THERE WILL BE SOME INCREASE IN CLOUDS AS A COLD FRONT SHIFTS EAST TOWARD THE LOWER LAKES. THE FRONT WILL BRING A CHANCE FOR RAIN AND SNOW SHOWERS...ACROSS THE LAKE ONTARIO REGION THURSDAY AND THURSDAY NIGHT. A BETTER CHANCE WILL BE LATER FRIDAY AND SATURDAY WHEN A STRONG COLD FRONT CROSSES THE REGION WITH CHANCES FOR RAIN AND SNOW. WINDS WILL ALSO BECOME STRONGER BEHIND THIS COLD FRONT TO START THE WEEKEND...THOUGH MODEL SOUNDINGS SUGGEST THE LOW LEVEL JET WILL NOT BE AS STRONG AS THIS SUNDAY`S EVENT. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AN AREA OF SHOWERS WILL MOVE FROM NORTHEASTER OHIO TO NORTHWESTERN NEW YORK THROUGH THE MORNING HOURS. EXPECT THIS AREA TO EXIT EAST OF LAKE ONTARIO EARLY AFTERNOON WHICH WILL PROBABLY PROVIDE A BRIEF BREAK FOR MOST SITES DURING THE AFTERNOON HOURS. FOR THE MOST PART...TAF LOCATIONS SHOULD STAY VFR TODAY...WITH THE EXCEPTION OF THE SOUTHERN TIER (JHW) WHERE IFR/MVFR CIGS WILL LIKELY PERSIST FOR MUCH OF THE DAY. SOUTHERLY WINDS OF 40 TO 50 KTS WILL PERSIST THROUGH MOST OF THE DAY. INITIALLY THIS WILL RESULT IN LLWS AT MOST TAF LOCATIONS SINCE IT WILL NOT MIX DOWN...BUT SUSPECT PARTIAL MIXING TODAY TO DIMINISH THE LLWS THIS AFTERNOON. DESPITE FAIRLY STRONG WINDS THIS EVENING...WINDS ALOFT WILL BE SO STRONG THAT MORE LLWS IS LIKELY WITH A 55-60 KNOT FLOW AT 2000 FEET. A POWERFUL COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST TONIGHT. THIS FRONT COULD BE ACCOMPANIED BY A LINE OF THUNDERSTORMS CAPABLE OF PRODUCING IFR/LOW MVFR CONDITIONS AND SURFACE WIND GUSTS TO 50 KNOTS. FOLLOWING THE FRONTAL PASSAGE...EXPECT WINDS TO VEER TO SOUTHWESTERLY AND INCREASE...PRODUCING A MORE PROLONGED ROUND OF 40-50 KNOT WIND GUSTS THAT WILL LAST INTO MONDAY MORNING. OTHERWISE...DRY WEATHER WILL RETURN FOLLOWING THE FROPA AS STRONG DRY SLOTTING OVERSPREADS THE REGION ALOFT...THOUGH SOME MVFR TO LOW VFR CIGS MAY LINGER. OUTLOOK... MONDAY...STRONG WINDS IN THE MORNING...OTHERWISE MVFR/VFR WITH A CHANCE OF SHOWERS EAST OF THE LAKES IN THE AFTERNOON. TUESDAY...VFR WITH LOCAL MVFR IN LIGHT LAKE EFFECT SNOW SHOWERS SOUTHEAST OF THE LAKES. WEDNESDAY AND THURSDAY...VFR. && .MARINE... SOUTHERLY WINDS WILL PERSIST TODAY...AND WILL BE GUSTY IN SOME LOCATIONS...PARTICULARLY ON LAKE ERIE. THIS INCREASING SOUTHERLY FLOW WILL ALSO BUILD WAVES ON EASTERN LAKE ONTARIO DUE TO THE LONGER FETCH. THE MAIN PERIOD OF CONCERN WILL BE THIS EVENING THROUGH MONDAY WHEN GALE FORCE WINDS ARE A NEAR CERTAINTY ON BOTH LAKES. LOW PRESSURE DEEPENING TO 970 MB SOUTH OF JAMES BAY LATE TONIGHT WILL PRODUCE A PERIOD OF SOLID GALES ON THE LAKES TONIGHT AND MONDAY. IT WILL BE A BIT MORE MARGINAL ON THE RIVERS...BUT THE SHEAR STRENGTH OF THE LOW AND STRONG WINDS ALOFT JUSTIFY GALES ON THE RIVERS TOO. WINDS WILL GRADUALLY DIMINISH MONDAY NIGHT AND TUESDAY AS THE FLOW BECOMES NORTHWESTERLY. && .TIDES/COASTAL FLOODING... A RAPIDLY DEEPENING AREA OF LOW PRESSURE MOVING FROM THE CENTRAL LAKES TOWARDS WESTERN QUEBEC WILL FOLLOW A FAVORABLE PATH TO PRODUCE STRONG SOUTHWEST WINDS ON LAKE ERIE AND PUSH RISING WATER TO THE NORTHEAST END OF THE LAKE. WINDS WILL SHIFT FROM SOUTHERLY TO SOUTHWESTERLY FOLLOWING A STRONG COLD FRONT LATE SUNDAY EVENING. NORMALLY THIS SCENARIO GIVEN THE FORECAST WIND SPEEDS WOULD NOT ALLOW THE LAKE LEVEL TO QUITE REACH FLOOD STAGE...WITH MODEL GUIDANCE SUGGESTING A PEAK AROUND 5 FEET. BUT THERE IS THE POTENTIAL FOR A SQUALL LINE ALONG THE COLD FRONT. SQUALL LINE DRIVEN SEICHE EVENTS ARE NOT AS COMMON AS SYNOPTICALLY DRIVEN...BUT IF THE SQUALL LINE IS STRONG ENOUGH IT MAY ENHANCE THE SEICHE AND PUSH THE WATER LEVEL AT BUFFALO TO NEAR THE FLOOD STAGE OF 8 FEET ABOVE LOW WATER DATUM. CONFIDENCE IN LAKESHORE FLOODING REMAINS MARGINAL GIVEN THE FAIRLY INFREQUENT NATURE OF SIMILAR EVENTS. WITH THIS IN MIND...A LAKESHORE FLOOD WATCH REMAINS IN EFFECT FOR TONIGHT INTO EARLY MONDAY MORNING. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 1 PM EST MONDAY FOR NYZ019-085. LAKESHORE FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR NYZ010-019-085. HIGH WIND WARNING FROM 7 PM THIS EVENING TO 4 PM EST MONDAY FOR NYZ007-008. HIGH WIND WATCH FROM THIS EVENING THROUGH MONDAY AFTERNOON FOR NYZ004>006. HIGH WIND WARNING FROM 7 PM THIS EVENING TO 1 PM EST MONDAY FOR NYZ001>003-010-011. HIGH WIND WATCH FROM THIS EVENING THROUGH MONDAY AFTERNOON FOR NYZ012>014-020-021. MARINE...GALE WARNING FROM 7 PM THIS EVENING TO 4 PM EST MONDAY FOR LEZ020-040-041. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ040-041. GALE WARNING FROM 7 PM THIS EVENING TO 4 PM EST MONDAY FOR LOZ030. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LOZ043>045. GALE WARNING FROM 7 PM THIS EVENING TO 7 PM EST MONDAY FOR LOZ043>045-063>065. GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST MONDAY FOR LOZ042-062. GALE WARNING FROM 1 AM TO 7 PM EST MONDAY FOR SLZ022- 024. && $$ SYNOPSIS...APFFEL NEAR TERM...APFFEL SHORT TERM...THOMAS LONG TERM...THOMAS/TJP AVIATION...APFFEL/JJR MARINE...APFFEL/THOMAS TIDES/COASTAL FLOODING...HITCHCOCK/APFFEL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1238 PM EST SUN NOV 17 2013 .SYNOPSIS... LOW PRESSURE OVER THE PLAINS STATES WILL DEEPEN RAPIDLY AS IT MOVES NORTHEAST TODAY REACHING NORTHERN LAKE MICHIGAN BY THIS EVENING AND INTO QUEBEC ON MONDAY. THIS WILL PUSH A STRONG COLD FRONT ACROSS THE AREA THIS EVENING. HIGH PRESSURE WILL MOVE EAST OUT OF THE SOUTHERN PLAINS STATES INTO THE OHIO VALLEY BY TUESDAY AND THEN OFF THE EAST COAST ON WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... REMOVED THUNDER ACROSS NORTH CENTRAL OHIO AND POINTS EAST UNTIL VERY LATE AFTERNOON/EVENING. WHILE I CANNOT RULE OUT THUNDER... WOULD LIKE TO MAKE THE THUNDER AND WIND WITH THE FRONT MORE OF THE FOCAL POINT OF THE FORECAST. TOUGH TO DO IN THESE DAYS OF AUTOMATED TEXT FORMATTERS...SO NOT SURE EXACTLY WHAT THE WORDING WILL SAY. BETTER CHANCE FOR THUNDER AT ANY TIME IN THE DRY SLOT THAT IS CREEPING ACROSS NORTHWEST OHIO. SORT OF LOOKS LIKE OKLAHOMA IN THE SPRING TIME...HMMM. NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. DID NUDGE UP HIGH TEMPERATURES A COUPLE OF DEGREES ACROSS NW OHIO AND PARTS OF NORTH CENTRAL OHIO WHERE THERE WILL NOT BE AS MANY SHOWERS. RECORD HIGH IN TOLEDO IS 71 AND WE WILL TAKE A RUN AT IT. 72 AT CLE IS POTENTIALLY WITHIN REACH. RELEVANT EARLY MORNING UPDATED DISCUSSION... SHOWERS CONTINUE TO MOVE EAST AND OUT OF THE AREA AT THIS TIME. CELLULAR CONVECTION CONTINUES TO MOVE INTO EXTREME NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN. THE WATER VAPOR PLUME IS ALSO PUSHING EAST ALLOWING FOR SOME DRIER AIR TO MOVE EAST AND ALLOW FOR A BREAK IN THE ACTION. LATEST HRRR MODEL SHOWS MASSIVE SQUALL LINE DEVELOPING OVER ILLINOIS AND RAPIDLY INTENSIFIES AS IT MOVES EAST TOWARD OHIO. TIMING WOULD PUT THE LINE AT TOLEDO AND FINDLAY AT 22Z AND TO CLEVELAND AND MANSFIELD BY ABOUT 00Z AND FINALLY TO ERIE AND YOUNGSTOWN BY 02Z OR SO. SO THE WAIT BEGINS. STAY TUNED. PREVIOUS DISCUSSION... THE LONG ANTICIPATED SEVERE WEATHER THREAT DAY HAS ARRIVED. TWO LOW PRESSURE SYSTEMS IN THE UPPER MIDWEST ARE BEGINNING TO MERGE AND INTENSIFY THIS MORNING. SOUTHERLY FLOW HAS INCREASED ACROSS THE FORECAST AREA AND THIS WILL BE THE BEGINNING OF THE STRENGTHENING WIND FLOW THROUGHOUT THE DAY. MODERATELY STRONG LOW LEVEL JET WILL REMAIN PERSISTENT OVER THE FORECAST AREA TODAY AND WITH THE WARM AIR ADVECTION...SOME OF THE STRONGER WINDS WILL MIX DOWN TO THE SURFACE. SO...WILL GO AHEAD AND ISSUE A WIND ADVISORY FOR THE ENTIRE AREA BUT WILL BE FOR MAINLY LATER THIS EVENING INTO TONIGHT SINCE THE STRONGEST WINDS WILL TAKE PLACE AFTER THE COLD FRONTAL PASSAGE. 60 TO 70 KNOT SPEED MAXIMUM AT 850 MB WILL POSE A PROBLEM AS CONVECTION DEVELOPS LATER THIS MORNING INTO THE AFTERNOON HOURS. THE STRONGER WINDS COULD BE FORCED TO THE SURFACE IN THE THUNDERSTORMS AND PRODUCE WIDESPREAD WIND DAMAGE. LATEST STORM PREDICTION CENTER OUTLOOK CONTINUES TO HIGHLIGHT A MODERATE RISK FOR SEVERE THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A HIGH RISK JUST WEST OF THE FORECAST AREA. EVEN THOUGH THE MAIN THREATS WILL BE THE STRONG DAMAGING WINDS...LATEST MODEL SOUNDING HODOGRAPHS INDICATE SOME FAIRLY HIGH LEVELS OF HELICITY...ESPECIALLY ACROSS AREAS FROM CLEVELAND TO AKRON CANTON WEST. I CANT RULE OUT THE POTENTIAL FOR ANY THUNDERSTORMS THAT DEVELOP THAT THEY COULD BEGIN TO ROTATE RATHER QUICKLY AND PRODUCE TORNADOES. TEMPERATURE DEW POINT SPREADS ARE PROGGED TO BE AT OR BELOW THE 5 DEGREE THRESHOLD AND THIS IS ONE KEY INGREDIENT FOR TORNADOES TO DEVELOP. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... THE SEVERE WEATHER THREAT WILL NOT BE OVER TONIGHT. THE COLD FRONT AND POTENTIAL SQUALL LINE IS EXPECTED TO MOVE THROUGH THE AREA THIS EVENING AND THIS IS WHEN WE HAVE THE HIGHEST THREAT FOR WIDESPREAD WIND DAMAGE. ONE FACTOR IS WE WILL BE LOSING THE DAY TIME HEATING AND THIS MAY HELP TO STABILIZE THINGS A BIT. AS THE COLD FRONT SHIFTS EAST...COLD AIR ADVECTION WILL TAKE PLACE AND ALLOW WINDS TO MIX DOWN TO THE SURFACE. WILL HOIST A WIND ADVISORY FOR TONIGHT DUE TO THE POST FRONTAL WINDS EXPECTED. AS THE STRONG LOW PRESSURE SYSTEM MOVES RATHER QUICKLY TO THE NORTHEAST...WINDS ARE EXPECTED TO DIMINISH FAIRLY QUICKLY MONDAY INTO TUESDAY. CYCLONIC FLOW AROUND THE BACK SIDE OF THE LOW AND IN ADVANCE OF THE NEXT HIGH PRESSURE WILL CAUSE SHOWERS TO CONTINUE OVER THE EXTREME NORTHEAST PORTION OF THE FORECAST AREA. OTHERWISE...DRIER AIR WILL BEGIN TO RETURN BACK TO THE REGION ON MONDAY. THE COLD AIR ADVECTION WILL LIKELY PRODUCE SOME LAKE EFFECT RAIN AND SNOW SHOWERS OVER THE NORTHEAST MONDAY NIGHT AND TUESDAY. THE HIGH WILL BUILD IN ACROSS THE OHIO VALLEY AND SHIFT THE FLOW AWAY FROM THE LAKE ENDING THE LAKE EFFECT THREAT. OTHERWISE...FAIR WEATHER IS EXPECTED ACROSS THE REST OF THE FORECAST AREA MONDAY INTO TUESDAY AND OVER ALL AREAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THE COLD FRONT WILL RESULT IN COLD AIR ADVECTION AND PLUNGE TEMPERATURES BACK TO NEAR NORMAL IN THE 40S FOR HIGHS AND OVERNIGHT LOWS IN THE 20S TO LOWER 30S. && .LONG TERM /THURSDAY THROUGH SATURDAY/... NOT MANY CHANGES TO THE LONG TERM TODAY. THE NEW GUIDANCE CONTINUES TO SHOW THE POSSIBILITY OF WARM AIR ADVECTION SHOWERS ON THURSDAY...ESPECIALLY IN THE WEST. UNSETTLED WEATHER WILL THEN CONTINUE INTO NEXT WEEKEND AS A SERIES OF FRONTAL SYSTEMS AFFECTS THE REGION. IT APPEARS BEST CHANCES FOR PRECIP WILL BE FRIDAY NIGHT INTO SATURDAY AS A WAVE MOVES ACROSS THE OHIO VALLEY. MOST OF THE PRECIP SHOULD BE LIQUID ALTHOUGH MIXED RAIN AND SNOW COULD OCCUR EARLY SATURDAY. TEMPS DURING THE PERIOD WILL BE SEASONABLE AND HAVE STAYED FAIRLY CLOSE TO GUIDANCE. && .AVIATION /18Z SUNDAY THROUGH THURSDAY/... SOUTHERLY WINDS WILL INCREASE THROUGH THE AFTERNOON WITH GUSTS TO 35 KNOTS COMMON ACROSS THE WEST AND ALONG THE LAKESHORE. EXPECT TO SEE MVFR CLOUD COVER TO SPREAD BACK INTO THE AREA FROM THE SOUTHWEST. THIS MAY BE A BIT SLOWER TO OCCUR ACROSS THE EAST BUT WITH SOME SCATTERED SHOWERS WE EXPECT THERE WILL STILL BE AT LEAST SOME PATCHY MVFR CONDITIONS. THE MAIN CONCERN WILL BE THE SEVERE THUNDERSTORM POTENTIAL ALONG A STRONG COLD FRONT THAT WILL ARRIVE IN THE TOLEDO AREA AROUND 22Z...KCLE AND KMFD AROUND 00Z AND KYNG AND KERI AROUND 02Z. SEVERE GUSTS WILL BE POSSIBLE WITH THE STRONGEST THUNDERSTORMS. WINDS IN THE WAKE OF THE FRONT WILL SHIFT TO THE SOUTHWEST AND INCREASE. MOST LOCATIONS WILL SEE GUSTS 35 TO 40 KNOTS THROUGH THE OVERNIGHT. OUTLOOK...NON-VFR CONDITIONS WILL BE SCATTERED ACROSS THE REGION IN SHOWERS. A FEW SHSN MONDAY NIGHT...MAINLY ACROSS NE OH/NW PA. CONDITIONS IMPROVING TO VFR FROM WEST TO EAST TUESDAY. && .MARINE... NO CHANGES TO THE HEADLINES ON THE LAKE TODAY. THE GALE STILL LOOKS GOOD FOR LATE TODAY AND TONIGHT. STILL EXPECTING A SQUALL LINE TO MOVE ACROSS THE LAKE THIS EVENING AND WIND GUSTS COULD APPROACH 50 KNOTS. WINDS WILL BECOME WESTERLY BEHIND THE COLD FRONT RESPONSIBLE FOR THE SQUALL LINE. SPEEDS SHOULD GRADUALLY DIMINISH ON MONDAY AND EXPECT A PROLONGED PERIOD OF SMALL CRAFT ADVISORIES ONCE THE GALE COMES DOWN. LOCAL GUIDANCE ALSO SHOWS WATER LEVELS MAKING A RUN FOR THE CRITICAL MARK LATE TONIGHT. WILL SEE HOW THINGS DEVELOP BUT LATER SHIFTS MAY NEED TO GO WITH A LOW WATER ADVISORY. THE FLOW WILL BECOME NW ON MONDAY AS HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. A SURFACE RIDGE WILL EVENTUALLY MOVE EAST OF THE LAKE TUESDAY NIGHT ALLOWING THE FLOW TO BECOME SOUTHERLY. SOUTH TO SOUTHWEST FLOW WILL THEN CONTINUE TILL A COLD FRONT CROSSES THE LAKE AT THE VERY END OF THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR OHZ003-006>014-017>023-027>033-036>038-047-089. PA...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR PAZ001>003. MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 4 PM EST MONDAY FOR LEZ061-142>149-162>169. LOW WATER ADVISORY FROM 7 PM THIS EVENING TO 4 PM EST MONDAY FOR LEZ142>144-162>164. && $$ SYNOPSIS...KOSARIK/LOMBARDY NEAR TERM...KOSARIK/LOMBARDY SHORT TERM...LOMBARDY LONG TERM...KUBINA AVIATION...MULLEN MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1033 AM EST SUN NOV 17 2013 .SYNOPSIS... LOW PRESSURE OVER THE PLAINS STATES WILL DEEPEN RAPIDLY AS IT MOVES NORTHEAST TODAY REACHING NORTHERN LAKE MICHIGAN BY THIS EVENING AND INTO QUEBEC ON MONDAY. THIS WILL PUSH A STRONG COLD FRONT ACROSS THE AREA THIS EVENING. HIGH PRESSURE WILL MOVE EAST OUT OF THE SOUTHERN PLAINS STATES INTO THE OHIO VALLEY BY TUESDAY AND THEN OFF THE EAST COAST ON WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... REMOVED THUNDER ACROSS NORTH CENTRAL OHIO AND POINTS EAST UNTIL VERY LATE AFTERNOON/EVENING. WHILE I CANNOT RULE OUT THUNDER... WOULD LIKE TO MAKE THE THUNDER AND WIND WITH THE FRONT MORE OF THE FOCAL POINT OF THE FORECAST. TOUGH TO DO IN THESE DAYS OF AUTOMATED TEXT FORMATTERS...SO NOT SURE EXACTLY WHAT THE WORDING WILL SAY. BETTER CHANCE FOR THUNDER AT ANY TIME IN THE DRY SLOT THAT IS CREEPING ACROSS NORTHWEST OHIO. SORT OF LOOKS LIKE OKLAHOMA IN THE SPRING TIME...HMMM. NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. DID NUDGE UP HIGH TEMPERATURES A COUPLE OF DEGREES ACROSS NW OHIO AND PARTS OF NORTH CENTRAL OHIO WHERE THERE WILL NOT BE AS MANY SHOWERS. RECORD HIGH IN TOLEDO IS 71 AND WE WILL TAKE A RUN AT IT. 72 AT CLE IS POTENTIALLY WITHIN REACH. RELEVANT EARLY MORNING UPDATED DISCUSSION... SHOWERS CONTINUE TO MOVE EAST AND OUT OF THE AREA AT THIS TIME. CELLULAR CONVECTION CONTINUES TO MOVE INTO EXTREME NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN. THE WATER VAPOR PLUME IS ALSO PUSHING EAST ALLOWING FOR SOME DRIER AIR TO MOVE EAST AND ALLOW FOR A BREAK IN THE ACTION. LATEST HRRR MODEL SHOWS MASSIVE SQUALL LINE DEVELOPING OVER ILLINOIS AND RAPIDLY INTENSIFIES AS IT MOVES EAST TOWARD OHIO. TIMING WOULD PUT THE LINE AT TOLEDO AND FINDLAY AT 22Z AND TO CLEVELAND AND MANSFIELD BY ABOUT 00Z AND FINALLY TO ERIE AND YOUNGSTOWN BY 02Z OR SO. SO THE WAIT BEGINS. STAY TUNED. PREVIOUS DISCUSSION... THE LONG ANTICIPATED SEVERE WEATHER THREAT DAY HAS ARRIVED. TWO LOW PRESSURE SYSTEMS IN THE UPPER MIDWEST ARE BEGINNING TO MERGE AND INTENSIFY THIS MORNING. SOUTHERLY FLOW HAS INCREASED ACROSS THE FORECAST AREA AND THIS WILL BE THE BEGINNING OF THE STRENGTHENING WIND FLOW THROUGHOUT THE DAY. MODERATELY STRONG LOW LEVEL JET WILL REMAIN PERSISTENT OVER THE FORECAST AREA TODAY AND WITH THE WARM AIR ADVECTION...SOME OF THE STRONGER WINDS WILL MIX DOWN TO THE SURFACE. SO...WILL GO AHEAD AND ISSUE A WIND ADVISORY FOR THE ENTIRE AREA BUT WILL BE FOR MAINLY LATER THIS EVENING INTO TONIGHT SINCE THE STRONGEST WINDS WILL TAKE PLACE AFTER THE COLD FRONTAL PASSAGE. 60 TO 70 KNOT SPEED MAXIMUM AT 850 MB WILL POSE A PROBLEM AS CONVECTION DEVELOPS LATER THIS MORNING INTO THE AFTERNOON HOURS. THE STRONGER WINDS COULD BE FORCED TO THE SURFACE IN THE THUNDERSTORMS AND PRODUCE WIDESPREAD WIND DAMAGE. LATEST STORM PREDICTION CENTER OUTLOOK CONTINUES TO HIGHLIGHT A MODERATE RISK FOR SEVERE THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A HIGH RISK JUST WEST OF THE FORECAST AREA. EVEN THOUGH THE MAIN THREATS WILL BE THE STRONG DAMAGING WINDS...LATEST MODEL SOUNDING HODOGRAPHS INDICATE SOME FAIRLY HIGH LEVELS OF HELICITY...ESPECIALLY ACROSS AREAS FROM CLEVELAND TO AKRON CANTON WEST. I CANT RULE OUT THE POTENTIAL FOR ANY THUNDERSTORMS THAT DEVELOP THAT THEY COULD BEGIN TO ROTATE RATHER QUICKLY AND PRODUCE TORNADOES. TEMPERATURE DEW POINT SPREADS ARE PROGGED TO BE AT OR BELOW THE 5 DEGREE THRESHOLD AND THIS IS ONE KEY INGREDIENT FOR TORNADOES TO DEVELOP. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... THE SEVERE WEATHER THREAT WILL NOT BE OVER TONIGHT. THE COLD FRONT AND POTENTIAL SQUALL LINE IS EXPECTED TO MOVE THROUGH THE AREA THIS EVENING AND THIS IS WHEN WE HAVE THE HIGHEST THREAT FOR WIDESPREAD WIND DAMAGE. ONE FACTOR IS WE WILL BE LOSING THE DAY TIME HEATING AND THIS MAY HELP TO STABILIZE THINGS A BIT. AS THE COLD FRONT SHIFTS EAST...COLD AIR ADVECTION WILL TAKE PLACE AND ALLOW WINDS TO MIX DOWN TO THE SURFACE. WILL HOIST A WIND ADVISORY FOR TONIGHT DUE TO THE POST FRONTAL WINDS EXPECTED. AS THE STRONG LOW PRESSURE SYSTEM MOVES RATHER QUICKLY TO THE NORTHEAST...WINDS ARE EXPECTED TO DIMINISH FAIRLY QUICKLY MONDAY INTO TUESDAY. CYCLONIC FLOW AROUND THE BACK SIDE OF THE LOW AND IN ADVANCE OF THE NEXT HIGH PRESSURE WILL CAUSE SHOWERS TO CONTINUE OVER THE EXTREME NORTHEAST PORTION OF THE FORECAST AREA. OTHERWISE...DRIER AIR WILL BEGIN TO RETURN BACK TO THE REGION ON MONDAY. THE COLD AIR ADVECTION WILL LIKELY PRODUCE SOME LAKE EFFECT RAIN AND SNOW SHOWERS OVER THE NORTHEAST MONDAY NIGHT AND TUESDAY. THE HIGH WILL BUILD IN ACROSS THE OHIO VALLEY AND SHIFT THE FLOW AWAY FROM THE LAKE ENDING THE LAKE EFFECT THREAT. OTHERWISE...FAIR WEATHER IS EXPECTED ACROSS THE REST OF THE FORECAST AREA MONDAY INTO TUESDAY AND OVER ALL AREAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THE COLD FRONT WILL RESULT IN COLD AIR ADVECTION AND PLUNGE TEMPERATURES BACK TO NEAR NORMAL IN THE 40S FOR HIGHS AND OVERNIGHT LOWS IN THE 20S TO LOWER 30S. && .LONG TERM /THURSDAY THROUGH SATURDAY/... NOT MANY CHANGES TO THE LONG TERM TODAY. THE NEW GUIDANCE CONTINUES TO SHOW THE POSSIBILITY OF WARM AIR ADVECTION SHOWERS ON THURSDAY...ESPECIALLY IN THE WEST. UNSETTLED WEATHER WILL THEN CONTINUE INTO NEXT WEEKEND AS A SERIES OF FRONTAL SYSTEMS AFFECTS THE REGION. IT APPEARS BEST CHANCES FOR PRECIP WILL BE FRIDAY NIGHT INTO SATURDAY AS A WAVE MOVES ACROSS THE OHIO VALLEY. MOST OF THE PRECIP SHOULD BE LIQUID ALTHOUGH MIXED RAIN AND SNOW COULD OCCUR EARLY SATURDAY. TEMPS DURING THE PERIOD WILL BE SEASONABLE AND HAVE STAYED FAIRLY CLOSE TO GUIDANCE. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... A LARGE AREA OF SHOWERS REMAINS OVER THE EASTERN HALF OF THE AREA THIS MORNING AND IS EXPECTED TO EXIT TO THE EAST IN A COUPLE OF HOURS. MOST LOCATIONS REMAIN VFR BUT SOME PATCHY MVFR IS BEING REPORTED. A LOT OF MVFR CIGS TO THE WEST AND EXPECT ALL AREAS TO DIP TO MVFR CIGS BY MIDDAY. SHOWER ACTIVITY TO THE WEST OF THE MAIN AREA WILL BE SCATTERED IN NATURE THIS MORNING. EXPECT MUCH OF THE AFTERNOON TO BE DRY WITH A FEW PEAKS OF SUNSHINE POSSIBLE. NEW GUIDANCE COMING IN CONTINUES TO SHOW A SQUALL LINE DEVELOPING OVER NW OH TOWARD EVENING. CONFIDENCE IN THIS SCENARIO IS UNUSUALLY HIGH. THIS LINE SHOULD REACH KTOL AND KFDY AROUND SUNSET AND IS THEN EXPECTED TO RACE EAST ACROSS THE REMAINDER OF THE AREA THIS EVENING. THE LINE COULD MOVE AS FAST AS 45 TO 50 KNOTS AT TIMES. VERY STRONG WINDS ARE FORECAST JUST ABOVE THE SURFACE AND ANY SIGNIFICANT RAIN WILL BRING THESE STRONG WINDS DOWN TO THE SURFACE. AS A RESULT HAVE CONTINUED TO HIT THE WINDS PRETTY HARD IN THE NEW FORECAST. A COLD FRONT WILL FOLLOW THE SQUALL LINE ACROSS THE AREA THIS EVENING AND EXPECT CIGS TO LIFT TO VFR AND THEN DISSIPATE FROM WEST TO EAST OVERNIGHT. WINDS TODAY WILL BE MAINLY FROM THE SOUTH WITH GUSTS INCREASING TO 35 KNOTS THIS AFTERNOON. THE FLOW BEHIND THE FRONT WILL BE WSW AND GUSTS COULD GET TO 40 KNOTS OVERNIGHT. OUTLOOK...NON-VFR CONDITIONS WILL CONTINUE SUNDAY NIGHT INTO MONDAY WITH A FEW SHRA. A FEW SHSN MONDAY NIGHT...MAINLY ACROSS NE OH/NW PA. CONDITIONS IMPROVING TO VFR FROM WEST TO EAST TUESDAY. && .MARINE... NO CHANGES TO THE HEADLINES ON THE LAKE TODAY. THE GALE STILL LOOKS GOOD FOR LATE TODAY AND TONIGHT. STILL EXPECTING A SQUALL LINE TO MOVE ACROSS THE LAKE THIS EVENING AND WIND GUSTS COULD APPROACH 50 KNOTS. WINDS WILL BECOME WESTERLY BEHIND THE COLD FRONT RESPONSIBLE FOR THE SQUALL LINE. SPEEDS SHOULD GRADUALLY DIMINISH ON MONDAY AND EXPECT A PROLONGED PERIOD OF SMALL CRAFT ADVISORIES ONCE THE GALE COMES DOWN. LOCAL GUIDANCE ALSO SHOWS WATER LEVELS MAKING A RUN FOR THE CRITICAL MARK LATE TONIGHT. WILL SEE HOW THINGS DEVELOP BUT LATER SHIFTS MAY NEED TO GO WITH A LOW WATER ADVISORY. THE FLOW WILL BECOME NW ON MONDAY AS HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. A SURFACE RIDGE WILL EVENTUALLY MOVE EAST OF THE LAKE TUESDAY NIGHT ALLOWING THE FLOW TO BECOME SOUTHERLY. SOUTH TO SOUTHWEST FLOW WILL THEN CONTINUE TILL A COLD FRONT CROSSES THE LAKE AT THE VERY END OF THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR OHZ003-006>014-017>023-027>033-036>038-047-089. PA...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR PAZ001>003. MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 4 PM EST MONDAY FOR LEZ061-142>149-162>169. && $$ SYNOPSIS...KOSARIK/LOMBARDY NEAR TERM...KOSARIK/LOMBARDY SHORT TERM...LOMBARDY LONG TERM...KUBINA AVIATION...KUBINA MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1020 AM EST SUN NOV 17 2013 .SYNOPSIS... LOW PRESSURE OVER THE PLAINS STATES WILL DEEPEN RAPIDLY AS IT MOVES NORTHEAST TODAY REACHING NORTHERN LAKE MICHIGAN BY THIS EVENING AND INTO QUEBEC ON MONDAY. THIS WILL PUSH A STRONG COLD FRONT ACROSS THE AREA THIS EVENING. HIGH PRESSURE WILL MOVE EAST OUT OF THE SOUTHERN PLAINS STATES INTO THE OHIO VALLEY BY TUESDAY AND THEN OFF THE EAST COAST ON WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... REMOVED THUNDER ACROSS NORTH CENTRAL OHIO AND POINTS EAST UNTIL VERY LATE AFTERNOON/EVENING. WHILE I CANNOT RULE OUT THUNDER... WOULD LIKE TO MAKE THE THUNDER AND WIND WITH THE FRONT MORE OF THE FOCAL POINT OF THE FORECAST. TOUGH TO DO IN THESE DAYS OF AUTOMATED TEXT FORMATTERS...SO NOT SURE EXACTLY WHAT THE WORDING WILL SAY. THUNDER FORECAST ON THE EAST FOR MIDDAY AND EARLY AFTERNOON. BETTER CHANCE FOR THUNDER AT ANY TIME IN THE DRY SLOT THAT IS CREEPING ACROSS NORTHWEST OHIO. SORT OF LOOKS LIKE OKLAHOMA IN THE SPRING TIME...HMMM. NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. DID NUDGE UP HIGH TEMPERATURES A COUPLE OF DEGREES ACROSS NW OHIO AND PARTS OF NORTH CENTRAL OHIO WHERE THERE WILL NOT BE AS MANY SHOWERS. RECORD HIGH IN TOLEDO IS 71 AND WE WILL TAKE A RUN AT IT. 72 AT CLE IS POTENTIALLY WITHIN REACH. RELEVANT EARLY MORNING UPDATED DISCUSSION... SHOWERS CONTINUE TO MOVE EAST AND OUT OF THE AREA AT THIS TIME. CELLULAR CONVECTION CONTINUES TO MOVE INTO EXTREME NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN. THE WATER VAPOR PLUME IS ALSO PUSHING EAST ALLOWING FOR SOME DRIER AIR TO MOVE EAST AND ALLOW FOR A BREAK IN THE ACTION. LATEST HRRR MODEL SHOWS MASSIVE SQUALL LINE DEVELOPING OVER ILLINOIS AND RAPIDLY INTENSIFIES AS IT MOVES EAST TOWARD OHIO. TIMING WOULD PUT THE LINE AT TOLEDO AND FINDLAY AT 22Z AND TO CLEVELAND AND MANSFIELD BY ABOUT 00Z AND FINALLY TO ERIE AND YOUNGSTOWN BY 02Z OR SO. SO THE WAIT BEGINS. STAY TUNED. PREVIOUS DISCUSSION... THE LONG ANTICIPATED SEVERE WEATHER THREAT DAY HAS ARRIVED. TWO LOW PRESSURE SYSTEMS IN THE UPPER MIDWEST ARE BEGINNING TO MERGE AND INTENSIFY THIS MORNING. SOUTHERLY FLOW HAS INCREASED ACROSS THE FORECAST AREA AND THIS WILL BE THE BEGINNING OF THE STRENGTHENING WIND FLOW THROUGHOUT THE DAY. MODERATELY STRONG LOW LEVEL JET WILL REMAIN PERSISTENT OVER THE FORECAST AREA TODAY AND WITH THE WARM AIR ADVECTION...SOME OF THE STRONGER WINDS WILL MIX DOWN TO THE SURFACE. SO...WILL GO AHEAD AND ISSUE A WIND ADVISORY FOR THE ENTIRE AREA BUT WILL BE FOR MAINLY LATER THIS EVENING INTO TONIGHT SINCE THE STRONGEST WINDS WILL TAKE PLACE AFTER THE COLD FRONTAL PASSAGE. 60 TO 70 KNOT SPEED MAXIMUM AT 850 MB WILL POSE A PROBLEM AS CONVECTION DEVELOPS LATER THIS MORNING INTO THE AFTERNOON HOURS. THE STRONGER WINDS COULD BE FORCED TO THE SURFACE IN THE THUNDERSTORMS AND PRODUCE WIDESPREAD WIND DAMAGE. LATEST STORM PREDICTION CENTER OUTLOOK CONTINUES TO HIGHLIGHT A MODERATE RISK FOR SEVERE THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A HIGH RISK JUST WEST OF THE FORECAST AREA. EVEN THOUGH THE MAIN THREATS WILL BE THE STRONG DAMAGING WINDS...LATEST MODEL SOUNDING HODOGRAPHS INDICATE SOME FAIRLY HIGH LEVELS OF HELICITY...ESPECIALLY ACROSS AREAS FROM CLEVELAND TO AKRON CANTON WEST. I CANT RULE OUT THE POTENTIAL FOR ANY THUNDERSTORMS THAT DEVELOP THAT THEY COULD BEGIN TO ROTATE RATHER QUICKLY AND PRODUCE TORNADOES. TEMPERATURE DEW POINT SPREADS ARE PROGGED TO BE AT OR BELOW THE 5 DEGREE THRESHOLD AND THIS IS ONE KEY INGREDIENT FOR TORNADOES TO DEVELOP. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... THE SEVERE WEATHER THREAT WILL NOT BE OVER TONIGHT. THE COLD FRONT AND POTENTIAL SQUALL LINE IS EXPECTED TO MOVE THROUGH THE AREA THIS EVENING AND THIS IS WHEN WE HAVE THE HIGHEST THREAT FOR WIDESPREAD WIND DAMAGE. ONE FACTOR IS WE WILL BE LOSING THE DAY TIME HEATING AND THIS MAY HELP TO STABILIZE THINGS A BIT. AS THE COLD FRONT SHIFTS EAST...COLD AIR ADVECTION WILL TAKE PLACE AND ALLOW WINDS TO MIX DOWN TO THE SURFACE. WILL HOIST A WIND ADVISORY FOR TONIGHT DUE TO THE POST FRONTAL WINDS EXPECTED. AS THE STRONG LOW PRESSURE SYSTEM MOVES RATHER QUICKLY TO THE NORTHEAST...WINDS ARE EXPECTED TO DIMINISH FAIRLY QUICKLY MONDAY INTO TUESDAY. CYCLONIC FLOW AROUND THE BACK SIDE OF THE LOW AND IN ADVANCE OF THE NEXT HIGH PRESSURE WILL CAUSE SHOWERS TO CONTINUE OVER THE EXTREME NORTHEAST PORTION OF THE FORECAST AREA. OTHERWISE...DRIER AIR WILL BEGIN TO RETURN BACK TO THE REGION ON MONDAY. THE COLD AIR ADVECTION WILL LIKELY PRODUCE SOME LAKE EFFECT RAIN AND SNOW SHOWERS OVER THE NORTHEAST MONDAY NIGHT AND TUESDAY. THE HIGH WILL BUILD IN ACROSS THE OHIO VALLEY AND SHIFT THE FLOW AWAY FROM THE LAKE ENDING THE LAKE EFFECT THREAT. OTHERWISE...FAIR WEATHER IS EXPECTED ACROSS THE REST OF THE FORECAST AREA MONDAY INTO TUESDAY AND OVER ALL AREAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THE COLD FRONT WILL RESULT IN COLD AIR ADVECTION AND PLUNGE TEMPERATURES BACK TO NEAR NORMAL IN THE 40S FOR HIGHS AND OVERNIGHT LOWS IN THE 20S TO LOWER 30S. && .LONG TERM /THURSDAY THROUGH SATURDAY/... NOT MANY CHANGES TO THE LONG TERM TODAY. THE NEW GUIDANCE CONTINUES TO SHOW THE POSSIBILITY OF WARM AIR ADVECTION SHOWERS ON THURSDAY...ESPECIALLY IN THE WEST. UNSETTLED WEATHER WILL THEN CONTINUE INTO NEXT WEEKEND AS A SERIES OF FRONTAL SYSTEMS AFFECTS THE REGION. IT APPEARS BEST CHANCES FOR PRECIP WILL BE FRIDAY NIGHT INTO SATURDAY AS A WAVE MOVES ACROSS THE OHIO VALLEY. MOST OF THE PRECIP SHOULD BE LIQUID ALTHOUGH MIXED RAIN AND SNOW COULD OCCUR EARLY SATURDAY. TEMPS DURING THE PERIOD WILL BE SEASONABLE AND HAVE STAYED FAIRLY CLOSE TO GUIDANCE. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... A LARGE AREA OF SHOWERS REMAINS OVER THE EASTERN HALF OF THE AREA THIS MORNING AND IS EXPECTED TO EXIT TO THE EAST IN A COUPLE OF HOURS. MOST LOCATIONS REMAIN VFR BUT SOME PATCHY MVFR IS BEING REPORTED. A LOT OF MVFR CIGS TO THE WEST AND EXPECT ALL AREAS TO DIP TO MVFR CIGS BY MIDDAY. SHOWER ACTIVITY TO THE WEST OF THE MAIN AREA WILL BE SCATTERED IN NATURE THIS MORNING. EXPECT MUCH OF THE AFTERNOON TO BE DRY WITH A FEW PEAKS OF SUNSHINE POSSIBLE. NEW GUIDANCE COMING IN CONTINUES TO SHOW A SQUALL LINE DEVELOPING OVER NW OH TOWARD EVENING. CONFIDENCE IN THIS SCENARIO IS UNUSUALLY HIGH. THIS LINE SHOULD REACH KTOL AND KFDY AROUND SUNSET AND IS THEN EXPECTED TO RACE EAST ACROSS THE REMAINDER OF THE AREA THIS EVENING. THE LINE COULD MOVE AS FAST AS 45 TO 50 KNOTS AT TIMES. VERY STRONG WINDS ARE FORECAST JUST ABOVE THE SURFACE AND ANY SIGNIFICANT RAIN WILL BRING THESE STRONG WINDS DOWN TO THE SURFACE. AS A RESULT HAVE CONTINUED TO HIT THE WINDS PRETTY HARD IN THE NEW FORECAST. A COLD FRONT WILL FOLLOW THE SQUALL LINE ACROSS THE AREA THIS EVENING AND EXPECT CIGS TO LIFT TO VFR AND THEN DISSIPATE FROM WEST TO EAST OVERNIGHT. WINDS TODAY WILL BE MAINLY FROM THE SOUTH WITH GUSTS INCREASING TO 35 KNOTS THIS AFTERNOON. THE FLOW BEHIND THE FRONT WILL BE WSW AND GUSTS COULD GET TO 40 KNOTS OVERNIGHT. OUTLOOK...NON-VFR CONDITIONS WILL CONTINUE SUNDAY NIGHT INTO MONDAY WITH A FEW SHRA. A FEW SHSN MONDAY NIGHT...MAINLY ACROSS NE OH/NW PA. CONDITIONS IMPROVING TO VFR FROM WEST TO EAST TUESDAY. && .MARINE... NO CHANGES TO THE HEADLINES ON THE LAKE TODAY. THE GALE STILL LOOKS GOOD FOR LATE TODAY AND TONIGHT. STILL EXPECTING A SQUALL LINE TO MOVE ACROSS THE LAKE THIS EVENING AND WIND GUSTS COULD APPROACH 50 KNOTS. WINDS WILL BECOME WESTERLY BEHIND THE COLD FRONT RESPONSIBLE FOR THE SQUALL LINE. SPEEDS SHOULD GRADUALLY DIMINISH ON MONDAY AND EXPECT A PROLONGED PERIOD OF SMALL CRAFT ADVISORIES ONCE THE GALE COMES DOWN. LOCAL GUIDANCE ALSO SHOWS WATER LEVELS MAKING A RUN FOR THE CRITICAL MARK LATE TONIGHT. WILL SEE HOW THINGS DEVELOP BUT LATER SHIFTS MAY NEED TO GO WITH A LOW WATER ADVISORY. THE FLOW WILL BECOME NW ON MONDAY AS HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. A SURFACE RIDGE WILL EVENTUALLY MOVE EAST OF THE LAKE TUESDAY NIGHT ALLOWING THE FLOW TO BECOME SOUTHERLY. SOUTH TO SOUTHWEST FLOW WILL THEN CONTINUE TILL A COLD FRONT CROSSES THE LAKE AT THE VERY END OF THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR OHZ003-006>014-017>023-027>033-036>038-047-089. PA...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR PAZ001>003. MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 4 PM EST MONDAY FOR LEZ061-142>149-162>169. && $$ SYNOPSIS...KOSARIK/LOMBARDY NEAR TERM...KOSARIK/LOMBARDY SHORT TERM...LOMBARDY LONG TERM...KUBINA AVIATION...KUBINA MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
642 AM EST SUN NOV 17 2013 .SYNOPSIS... A DOUBLED BARRELED LOW PRESSURE FROM SOUTHERN MINNESOTA TO WESTERN KANSAS WILL MOVE TO NORTHERN LAKE MICHIGAN BY THIS EVENING. MEANWHILE...THE LOW PRESSURE WILL DEEPEN RAPIDLY AS IT MOVES INTO WEST CENTRAL QUEBEC BY MONDAY AFTERNOON. A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE AREA TONIGHT. HIGH PRESSURE WILL MOVE EAST OUT OF THE SOUTHERN PLAINS STATES INTO THE OHIO VALLEY BY TUESDAY AND THEN OFF THE EAST COAST ON WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SHOWERS CONTINUE TO MOVE EAST AND OUT OF THE AREA AT THIS TIME. CELLULAR CONVECTION CONTINUES TO MOVE INTO EXTREME NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN. THE WATER VAPOR PLUME IS ALSO PUSHING EAST ALLOWING FOR SOME DRIER AIR TO MOVE EAST AND ALLOW FOR A BREAK IN THE ACTION. LATEST HRRR MODEL SHOWS MASSIVE SQUALL LINE DEVELOPING OVER ILLINOIS AND RAPIDLY INTENSIFIES AS IT MOVES EAST TOWARD OHIO. TIMING WOULD PUT THE LINE AT TOLEDO AND FINDLAY AT 22Z AND TO CLEVELAND AND MANSFIELD BY ABOUT 00Z AND FINALLY TO ERIE AND YOUNGSTOWN BY 02Z OR SO. SO THE WAIT BEGINS. STAY TUNED. PREVIOUS DISCUSSION... THE LONG ANTICIPATED SEVERE WEATHER THREAT DAY HAS ARRIVED. TWO LOW PRESSURE SYSTEMS IN THE UPPER MIDWEST ARE BEGINNING TO MERGE AND INTENSIFY THIS MORNING. SOUTHERLY FLOW HAS INCREASED ACROSS THE FORECAST AREA AND THIS WILL BE THE BEGINNING OF THE STRENGTHENING WIND FLOW THROUGHOUT THE DAY. MODERATELY STRONG LOW LEVEL JET WILL REMAIN PERSISTENT OVER THE FORECAST AREA TODAY AND WITH THE WARM AIR ADVECTION...SOME OF THE STRONGER WINDS WILL MIX DOWN TO THE SURFACE. SO...WILL GO AHEAD AND ISSUE A WIND ADVISORY FOR THE ENTIRE AREA BUT WILL BE FOR MAINLY LATER THIS EVENING INTO TONIGHT SINCE THE STRONGEST WINDS WILL TAKE PLACE AFTER THE COLD FRONTAL PASSAGE. 60 TO 70 KNOT SPEED MAXIMUM AT 850 MB WILL POSE A PROBLEM AS CONVECTION DEVELOPS LATER THIS MORNING INTO THE AFTERNOON HOURS. THE STRONGER WINDS COULD BE FORCED TO THE SURFACE IN THE THUNDERSTORMS AND PRODUCE WIDESPREAD WIND DAMAGE. LATEST STORM PREDICTION CENTER OUTLOOK CONTINUES TO HIGHLIGHT A MODERATE RISK FOR SEVERE THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A HIGH RISK JUST WEST OF THE FORECAST AREA. EVEN THOUGH THE MAIN THREATS WILL BE THE STRONG DAMAGING WINDS...LATEST MODEL SOUNDING HODOGRAPHS INDICATE SOME FAIRLY HIGH LEVELS OF HELICITY...ESPECIALLY ACROSS AREAS FROM CLEVELAND TO AKRON CANTON WEST. I CANT RULE OUT THE POTENTIAL FOR ANY THUNDERSTORMS THAT DEVELOP THAT THEY COULD BEGIN TO ROTATE RATHER QUICKLY AND PRODUCE TORNADOES. TEMPERATURE DEW POINT SPREADS ARE PROGGED TO BE AT OR BELOW THE 5 DEGREE THRESHOLD AND THIS IS ONE KEY INGREDIENT FOR TORNADOES TO DEVELOP. LOOKING AT THE LATEST WATER VAPOR IMAGERY SHOWS AN EXTENSIVE AREA OF MOISTURE STREAMING NORTH ACROSS THE FORECAST AREA AT THIS TIME. HOWEVER...JUST WEST OF THE AREA...THIS MOISTURE PLUME DIMINISHES AND THIS IS RESULTING IN CLEARING SKIES WELL AHEAD OF THE COLD FRONT. WITH THIS IN MIND...I AM CONCERNED THAT WE WILL SEE A LOT MORE SUN THAN I CURRENTLY HAVE IN THE FORECAST. IF THIS IS THE CASE...THEN CURRENT FORECAST TEMPERATURES COULD BE TOO LOW AND THEREFORE WILL SEE EVEN GREATER INSTABILITY DEVELOP. THIS WILL HAVE TO BE WATCHED CLOSELY TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... THE SEVERE WEATHER THREAT WILL NOT BE OVER TONIGHT. THE COLD FRONT AND POTENTIAL SQUALL LINE IS EXPECTED TO MOVE THROUGH THE AREA THIS EVENING AND THIS IS WHEN WE HAVE THE HIGHEST THREAT FOR WIDESPREAD WIND DAMAGE. ONE FACTOR IS WE WILL BE LOSING THE DAY TIME HEATING AND THIS MAY HELP TO STABILIZE THINGS A BIT. AS THE COLD FRONT SHIFTS EAST...COLD AIR ADVECTION WILL TAKE PLACE AND ALLOW WINDS TO MIX DOWN TO THE SURFACE. WILL HOIST A WIND ADVISORY FOR TONIGHT DUE TO THE POST FRONTAL WINDS EXPECTED. AS THE STRONG LOW PRESSURE SYSTEM MOVES RATHER QUICKLY TO THE NORTHEAST...WINDS ARE EXPECTED TO DIMINISH FAIRLY QUICKLY MONDAY INTO TUESDAY. CYCLONIC FLOW AROUND THE BACK SIDE OF THE LOW AND IN ADVANCE OF THE NEXT HIGH PRESSURE WILL CAUSE SHOWERS TO CONTINUE OVER THE EXTREME NORTHEAST PORTION OF THE FORECAST AREA. OTHERWISE...DRIER AIR WILL BEGIN TO RETURN BACK TO THE REGION ON MONDAY. THE COLD AIR ADVECTION WILL LIKELY PRODUCE SOME LAKE EFFECT RAIN AND SNOW SHOWERS OVER THE NORTHEAST MONDAY NIGHT AND TUESDAY. THE HIGH WILL BUILD IN ACROSS THE OHIO VALLEY AND SHIFT THE FLOW AWAY FROM THE LAKE ENDING THE LAKE EFFECT THREAT. OTHERWISE...FAIR WEATHER IS EXPECTED ACROSS THE REST OF THE FORECAST AREA MONDAY INTO TUESDAY AND OVER ALL AREAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THE COLD FRONT WILL RESULT IN COLD AIR ADVECTION AND PLUNGE TEMPERATURES BACK TO NEAR NORMAL IN THE 40S FOR HIGHS AND OVERNIGHT LOWS IN THE 20S TO LOWER 30S. && .LONG TERM /THURSDAY THROUGH SATURDAY/... NOT MANY CHANGES TO THE LONG TERM TODAY. THE NEW GUIDANCE CONTINUES TO SHOW THE POSSIBILITY OF WARM AIR ADVECTION SHOWERS ON THURSDAY...ESPECIALLY IN THE WEST. UNSETTLED WEATHER WILL THEN CONTINUE INTO NEXT WEEKEND AS A SERIES OF FRONTAL SYSTEMS AFFECTS THE REGION. IT APPEARS BEST CHANCES FOR PRECIP WILL BE FRIDAY NIGHT INTO SATURDAY AS A WAVE MOVES ACROSS THE OHIO VALLEY. MOST OF THE PRECIP SHOULD BE LIQUID ALTHOUGH MIXED RAIN AND SNOW COULD OCCUR EARLY SATURDAY. TEMPS DURING THE PERIOD WILL BE SEASONABLE AND HAVE STAYED FAIRLY CLOSE TO GUIDANCE. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A LARGE AREA OF SHOWERS REMAINS OVER THE EASTERN HALF OF THE AREA THIS MORNING AND IS EXPECTED TO EXIT TO THE EAST IN A COUPLE OF HOURS. MOST LOCATIONS REMAIN VFR BUT SOME PATCHY MVFR IS BEING REPORTED. A LOT OF MVFR CIGS TO THE WEST AND EXPECT ALL AREAS TO DIP TO MVFR CIGS BY MIDDAY. SHOWER ACTIVITY TO THE WEST OF THE MAIN AREA WILL BE SCATTERED IN NATURE THIS MORNING. EXPECT MUCH OF THE AFTERNOON TO BE DRY WITH A FEW PEAKS OF SUNSHINE POSSIBLE. NEW GUIDANCE COMING IN CONTINUES TO SHOW A SQUALL LINE DEVELOPING OVER NW OH TOWARD EVENING. CONFIDENCE IN THIS SCENARIO IS UNUSUALLY HIGH. THIS LINE SHOULD REACH KTOL AND KFDY AROUND SUNSET AND IS THEN EXPECTED TO RACE EAST ACROSS THE REMAINDER OF THE AREA THIS EVENING. THE LINE COULD MOVE AS FAST AS 45 TO 50 KNOTS AT TIMES. VERY STRONG WINDS ARE FORECAST JUST ABOVE THE SURFACE AND ANY SIGNIFICANT RAIN WILL BRING THESE STRONG WINDS DOWN TO THE SURFACE. AS A RESULT HAVE CONTINUED TO HIT THE WINDS PRETTY HARD IN THE NEW FORECAST. A COLD FRONT WILL FOLLOW THE SQUALL LINE ACROSS THE AREA THIS EVENING AND EXPECT CIGS TO LIFT TO VFR AND THEN DISSIPATE FROM WEST TO EAST OVERNIGHT. WINDS TODAY WILL BE MAINLY FROM THE SOUTH WITH GUSTS INCREASING TO 35 KNOTS THIS AFTERNOON. THE FLOW BEHIND THE FRONT WILL BE WSW AND GUSTS COULD GET TO 40 KNOTS OVERNIGHT. OUTLOOK...NON-VFR CONDITIONS WILL CONTINUE SUNDAY NIGHT INTO MONDAY WITH A FEW SHRA. A FEW SHSN MONDAY NIGHT...MAINLY ACROSS NE OH/NW PA. CONDITIONS IMPROVING TO VFR FROM WEST TO EAST TUESDAY. && .MARINE... NO CHANGES TO THE HEADLINES ON THE LAKE TODAY. THE GALE STILL LOOKS GOOD FOR LATE TODAY AND TONIGHT. STILL EXPECTING A SQUALL LINE TO MOVE ACROSS THE LAKE THIS EVENING AND WIND GUSTS COULD APPROACH 50 KNOTS. WINDS WILL BECOME WESTERLY BEHIND THE COLD FRONT RESPONSIBLE FOR THE SQUALL LINE. SPEEDS SHOULD GRADUALLY DIMINISH ON MONDAY AND EXPECT A PROLONGED PERIOD OF SMALL CRAFT ADVISORIES ONCE THE GALE COMES DOWN. LOCAL GUIDANCE ALSO SHOWS WATER LEVELS MAKING A RUN FOR THE CRITICAL MARK LATE TONIGHT. WILL SEE HOW THINGS DEVELOP BUT LATER SHIFTS MAY NEED TO GO WITH A LOW WATER ADVISORY. THE FLOW WILL BECOME NW ON MONDAY AS HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. A SURFACE RIDGE WILL EVENTUALLY MOVE EAST OF THE LAKE TUESDAY NIGHT ALLOWING THE FLOW TO BECOME SOUTHERLY. SOUTH TO SOUTHWEST FLOW WILL THEN CONTINUE TILL A COLD FRONT CROSSES THE LAKE AT THE VERY END OF THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR OHZ003-006>014-017>023-027>033-036>038-047-089. PA...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR PAZ001>003. MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 4 PM EST MONDAY FOR LEZ061-142>149-162>169. && $$ SYNOPSIS...LOMBARDY NEAR TERM...LOMBARDY SHORT TERM...LOMBARDY LONG TERM...KUBINA AVIATION...KUBINA MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
505 PM EST SUN NOV 17 2013 .SYNOPSIS... A POTENT STORM SYSTEM WILL BE HEADED ACROSS THE UPPER MIDWEST AND THROUGH THE GREAT LAKES TODAY AND TONIGHT. THIS WILL BRING A STRONG COLD FRONT THROUGH THE REGION OVERNIGHT. COOLER AND DRIER...BUT WINDY CONDITIONS WILL FOLLOW BEHIND THE FRONT ON MONDAY...WITH HIGH PRESSURE RETURNING FAIR WEATHER TO THE AREA INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... THE RADAR HASN`T CHANGED APPRECIABLY IN THE LAST SEVERAL HOURS WITH GENERALLY LIGHT-MODERATE STRATIFORM RAINS CONTINUING OVER ABOUT THE NWRN 1/2-2/3 OF MY FCST AREA. EXPECT THIS TO CONTINUE INTO THE EVENING OUT AHEAD OF ALL THE MAIN ACTION THAT IS REALLY GEARING UP NOW OVER ILLINOIS IN THE FORM OF A VIOLENT SQUALL LINE THAT HAS ALREADY TRIGGERED SEVERAL DAMAGING TORNADOES. THE LINE OF STORMS WILL CONTINUE EAST THIS EVENING AND EVENTUALLY RACE ACROSS OUR AREA LATE THIS EVENING INTO THE WEE HOURS OF MONDAY MORNING. INSTABILITY WILL AS USUAL BE LIMITED...BUT SHEAR IS EXTREMELY STRONG. WHILE THE 15Z HRRR AND LATEST WRF RUNS INDICATE A WEAKENING TREND AS THE LINE MOVES OUR WAY...IT STILL LOOKS GOOD FOR ISOLATED STRONG WIND GUSTS ALONG AND JUST AHEAD OF THE COLD FRONT. BEST TIME FRAME FOR THE WORST OF THE WEATHER OVERNIGHT LOOKS TO BE ABOUT 03-09Z WHEN THE BIGGEST PWATS AND LOW LEVEL WINDS SURGE THROUGH THE AREA. 850 WINDS ARE PROGGED IN THE 50-70KT RANGE...SOME 3-4STD ABOVE NORMAL. WE EXPECT THE LINE TO BRING BRIEF DOWNPOURS AND THE INITIAL BLAST OF STRONG AND POSSIBLY DAMAGING WIND GUSTS. THEN OVERALL GRADIENT WINDS SHOULD KICK IN AND GUST IN THE 25-45MPH RANGE FOR A TIME. SHORT RANGE OPERATIONAL MODELS ARE SHOWING A STRONG ISSALOBARIC SURGE BEHIND THE FRONT SUPPORTING THE IDEA OF GUSTY POST FRONTAL WINDS...AT LEAST THROUGH EARLY MONDAY MORNING WHEN THE STRONGEST WINDS SHOULD THEN SHIFT OFF TO OUR NORTH AND NORTHEAST. A WIND ADVISORY HAS BEEN ISSUED FOR LATER TONIGHT THROUGH EARLY MONDAY MORNING. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... THE COLD FRONT SHOULD BE EXITING THE COASTAL PLAIN BY 12Z MONDAY...LEAVING PA IN A GUSTY WEST-SOUTHWEST FLOW. TEMPERATURES...AT LEAST INITIALLY WILL NOT BE ALL THAT COLD WITHIN THE NEW AIRMASS. ANY SHOWERS THAT DEVELOP AS THE COOLER AIR MOVES OVER THE GREAT LAKES WILL ONLY GRADUALLY MIX WITH WET SNOW BY THE END OF THE DAY OVER THE NW. THE BULK OF THE REST OF THE REGION WILL ENJOY THE DRY SLOT...AND DESPITE BEING RATHER WINDY WILL SEE HIGHS THAT WILL STILL AVERAGE SEVERAL DEG ABOVE NORMAL FOR NOVEMBER OVER ALL BUT THE FAR NW. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... IN THE WAKE OF FRONTAL/TROF PASSAGE ON MONDAY...UPPER RIDGING WILL DOMINATE THE MIDDLE ATLANTIC ON TUESDAY AND EARLY WEDNESDAY. UPPER FLOW WILL THEN TURN SOUTHWESTHERLY THROUGH MUCH OF THE REMAINER OF THE LONG TERM PERIOD AS A SRN STREAM UPPER LOW IS FORECAST TO DEVELOP OVER SRN CALIFORNIA. A PRONOUNCED NORTHERN STREAM UPPER TROF IS FORECAST TO DROP THROUGH THE GREAT LAKES LATE IN THE WEEK AND TOWARDS PA NEXT WEEKEND. AT THE SFC...HIGH PRESSURE...EXTENDING FROM NEW ENGLAND TO THE GULF COAST...WILL DOMINATE MUCH OF WEEK. THIS WILL PROVIDE DRY WEATHER WITH NEAR SEASONAL TEMPERATURES. THE LATE WEEK UPPER TROF WILL BRING A COLD FRONT ACROSS PA ON SATURDAY WITH THE MOST SIGNIFICANT CHANCES FOR PCPN DURING THIS FORECAST PD...NEXT SAT INTO SUNDAY. TEMPERATURES WILL BE COLD ENOUGH FOR SNOW OR A MIX OF SNOW OR RAIN OVER A GOOD PORTION OF THE CWA WITH THIS FROPA. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/... ADJUSTMENTS MADE FOR CURRENT AND EXPECTED CONDITIONS. EARLIER DISCUSSION BELOW. WIDESPREAD REDUCED CIG/VIZ IN PLACE AT ALL TERMINALS EXCEPT JST WHICH IS ON THE EDGE OF THE LOWER CLOUDS AND VIZ ASSOCIATED WITH THE ADVANCING RAIN. RADAR TRENDS INDICATE THE NW 1/2-2/3RDS OF THE AIRSPACE WILL SEE SHOWERS INTO THE EVENING WITH WIDESPREAD IFR/MVFR CONTINUING TONIGHT WILL BE A VERY ACTIVE PERIOD WITH A STRONG COLD FRONT AND ATTENDANT LOW-TOPPED SQUALL LINE EXPECTED TO RACE EWD ACROSS THE AIRSPACE. SOUTHERLY WINDS WILL STEADILY INCREASE AHEAD OF THE FRONT WITH LLWS EXPECTED GIVEN 50+KT LOW LEVEL JET. MODERATE TO HEAVY SHOWERS AND LOCAL HIGHER WIND GUSTS WILL BE POSSIBLE ALONG AND IMMEDIATELY BEHIND THE SQUALL LINE WITH AN ABRUPT WIND SHIFT TO THE WEST- SOUTHWEST. GUSTY WINDS WILL CONTINUE INTO EARLY MONDAY WITH FQNT GUSTS IN THE 25-45MPH RANGE..ESPECIALLY OVER WESTERN AREAS. MONDAY WILL SEE RAPID IMPROVEMENT IN CEILING/VIZ AS THE FRONT MOVES OUT OF THE REGION...BUT SOME LOCALLY REDUCED CONDITIONS WILL BECOME POSSIBLE ONCE AGAIN OVER THE NW AS COOLER AIR BEGINS TO SWEEP OVER THE GR LAKES AND BRING SOME SCATTERED RAIN/SNOW SHOWERS. THE WIND WILL STAY GUSTY IN THE 20-35MPH RANGE...GRADUALLY DIMINISHING IN THE AFTERNOON. OUTLOOK... TUE...MAINLY VFR...LOCALLY MVFR OVER THE NW WITH SCATTERED SNOW SHOWERS. WED-THU...NO SIG WX. FRI...SHOWERS POSSIBLE...WITH NEXT FRONTAL SYSTEM. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 11 PM THIS EVENING TO 8 AM EST MONDAY FOR PAZ004>006-010>012-017>019-024-025-033-034-037-041-042-045-046. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...FITZGERALD/LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
424 PM EST SUN NOV 17 2013 .SYNOPSIS... A POTENT STORM SYSTEM WILL BE HEADED ACROSS THE UPPER MIDWEST AND THROUGH THE GREAT LAKES TODAY AND TONIGHT. THIS WILL BRING A STRONG COLD FRONT THROUGH THE REGION OVERNIGHT. COOLER AND DRIER...BUT WINDY CONDITIONS WILL FOLLOW BEHIND THE FRONT ON MONDAY...WITH HIGH PRESSURE RETURNING FAIR WEATHER TO THE AREA INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... THE RADAR HASN`T CHANGED APPRECIABLY IN THE LAST SEVERAL HOURS WITH GENERALLY LIGHT-MODERATE STRATIFORM RAINS CONTINUING OVER ABOUT THE NWRN 1/2-2/3 OF MY FCST AREA. EXPECT THIS TO CONTINUE INTO THE EVENING OUT AHEAD OF ALL THE MAIN ACTION THAT IS REALLY GEARING UP NOW OVER ILLINOIS IN THE FORM OF A VIOLENT SQUALL LINE THAT HAS ALREADY TRIGGERED SEVERAL DAMAGING TORNADOES. THE LINE OF STORMS WILL CONTINUE EAST THIS EVENING AND EVENTUALLY RACE ACROSS OUR AREA LATE THIS EVENING INTO THE WEE HOURS OF MONDAY MORNING. INSTABILITY WILL AS USUAL BE LIMITED...BUT SHEAR IS EXTREMELY STRONG. WHILE THE 15Z HRRR AND LATEST WRF RUNS INDICATE A WEAKENING TREND AS THE LINE MOVES OUR WAY...IT STILL LOOKS GOOD FOR ISOLATED STRONG WIND GUSTS ALONG AND JUST AHEAD OF THE COLD FRONT. BEST TIME FRAME FOR THE WORST OF THE WEATHER OVERNIGHT LOOKS TO BE ABOUT 03-09Z WHEN THE BIGGEST PWATS AND LOW LEVEL WINDS SURGE THROUGH THE AREA. 850 WINDS ARE PROGGED IN THE 50-70KT RANGE...SOME 3-4STD ABOVE NORMAL. WE EXPECT THE LINE TO BRING BRIEF DOWNPOURS AND THE INITIAL BLAST OF STRONG AND POSSIBLY DAMAGING WIND GUSTS. THEN OVERALL GRADIENT WINDS SHOULD KICK IN AND GUST IN THE 25-45MPH RANGE FOR A TIME. SHORT RANGE OPERATIONAL MODELS ARE SHOWING A STRONG ISSALOBARIC SURGE BEHIND THE FRONT SUPPORTING THE IDEA OF GUSTY POST FRONTAL WINDS...AT LEAST THROUGH EARLY MONDAY MORNING WHEN THE STRONGEST WINDS SHOULD THEN SHIFT OFF TO OUR NORTH AND NORTHEAST. A WIND ADVISORY HAS BEEN ISSUED FOR LATER TONIGHT THROUGH EARLY MONDAY MORNING. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... THE COLD FRONT SHOULD BE EXITING THE COASTAL PLAIN BY 12Z MONDAY...LEAVING PA IN A GUSTY WEST-SOUTHWEST FLOW. TEMPERATURES...AT LEAST INITIALLY WILL NOT BE ALL THAT COLD WITHIN THE NEW AIRMASS. ANY SHOWERS THAT DEVELOP AS THE COOLER AIR MOVES OVER THE GREAT LAKES WILL ONLY GRADUALLY MIX WITH WET SNOW BY THE END OF THE DAY OVER THE NW. THE BULK OF THE REST OF THE REGION WILL ENJOY THE DRY SLOT...AND DESPITE BEING RATHER WINDY WILL SEE HIGHS THAT WILL STILL AVERAGE SEVERAL DEG ABOVE NORMAL FOR NOVEMBER OVER ALL BUT THE FAR NW. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... IN THE WAKE OF FRONTAL/TROF PASSAGE ON MONDAY...UPPER RIDGING WILL DOMINATE THE MIDDLE ATLANTIC ON TUESDAY AND EARLY WEDNESDAY. UPPER FLOW WILL THEN TURN SOUTHWESTHERLY THROUGH MUCH OF THE REMAINER OF THE LONG TERM PERIOD AS A SRN STREAM UPPER LOW IS FORECAST TO DEVELOP OVER SRN CALIFORNIA. A PRONOUNCED NORTHERN STREAM UPPER TROF IS FORECAST TO DROP THROUGH THE GREAT LAKES LATE IN THE WEEK AND TOWARDS PA NEXT WEEKEND. AT THE SFC...HIGH PRESSURE...EXTENDING FROM NEW ENGLAND TO THE GULF COAST...WILL DOMINATE MUCH OF WEEK. THIS WILL PROVIDE DRY WEATHER WITH NEAR SEASONAL TEMPERATURES. THE LATE WEEK UPPER TROF WILL BRING A COLD FRONT ACROSS PA ON SATURDAY WITH THE MOST SIGNIFICANT CHANCES FOR PCPN DURING THIS FORECAST PD...NEXT SAT INTO SUNDAY. TEMPERATURES WILL BE COLD ENOUGH FOR SNOW OR A MIX OF SNOW OR RAIN OVER A GOOD PORTION OF THE CWA WITH THIS FROPA. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/... WIDESPREAD REDUCED CIG/VIZ IN PLACE AT ALL TERMINALS EXCEPT JST WHICH IS ON THE EDGE OF THE LOWER CLOUDS AND VIZ ASSOCIATED WITH THE ADVANCING RAIN. RADAR TRENDS INDICATE THE NW 1/2-2/3RDS OF THE AIRSPACE WILL SEE SHOWERS INTO THE EVENING WITH WIDESPREAD IFR/MVFR CONTINUING TONIGHT WILL BE A VERY ACTIVE PERIOD WITH A STRONG COLD FRONT AND ATTENDANT LOW-TOPPED SQUALL LINE EXPECTED TO RACE EWD ACROSS THE AIRSPACE. SOUTHERLY WINDS WILL STEADILY INCREASE AHEAD OF THE FRONT WITH LLWS EXPECTED GIVEN 50+KT LOW LEVEL JET. MODERATE TO HEAVY SHOWERS AND LOCAL HIGHER WIND GUSTS WILL BE POSSIBLE ALONG AND IMMEDIATELY BEHIND THE SQUALL LINE WITH AN ABRUPT WIND SHIFT TO THE WEST- SOUTHWEST. GUSTY WINDS WILL CONTINUE INTO EARLY MONDAY WITH FQNT GUSTS IN THE 25-45MPH RANGE..ESPECIALLY OVER WESTERN AREAS. MONDAY WILL SEE RAPID IMPROVEMENT IN CEILING/VIZ AS THE FRONT MOVES OUT OF THE REGION...BUT SOME LOCALLY REDUCED CONDITIONS WILL BECOME POSSIBLE ONCE AGAIN OVER THE NW AS COOLER AIR BEGINS TO SWEEP OVER THE GR LAKES AND BRING SOME SCATTERED RAIN/SNOW SHOWERS. THE WIND WILL STAY GUSTY IN THE 20-35MPH RANGE...GRADUALLY DIMINISHING IN THE AFTERNOON. OUTLOOK... TUE...MAINLY VFR...LOCALLY MVFR OVER THE NW WITH SCATTERED SNOW SHOWERS. WED-THU...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 11 PM THIS EVENING TO 8 AM EST MONDAY FOR PAZ004>006-010>012-017>019-024-025-033-034-037-041-042-045-046. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
141 PM EST SUN NOV 17 2013 .SYNOPSIS... A POTENT STORM SYSTEM WILL BE HEADED ACROSS THE UPPER MIDWEST AND THROUGH THE GREAT LAKES TODAY AND TONIGHT. THIS WILL BRING A STRONG COLD FRONT THROUGH THE REGION OVERNIGHT. COOLER AND DRIER...BUT WINDY CONDITIONS WILL FOLLOW BEHIND THE FRONT ON MONDAY...WITH HIGH PRESSURE RETURNING FAIR WEATHER TO THE AREA INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE RADAR HASN`T CHANGED APPRECIABLY IN THE LAST SEVERAL HOURS WITH GENERALLY LIGHT-MODERATE STRATIFORM RAINS CONTINUING OVER ABOUT THE NWRN 1/2-2/3 OF MY FCST AREA. EXPECT THIS TO CONTINUE INTO THE EVENING OUT AHEAD OF ALL THE MAIN ACTION THAT IS REALLY GEARING UP NOW OVER ILLINOIS IN THE FORM OF A VIOLENT SQUALL LINE THAT HAS ALREADY TRIGGERED SEVERAL DAMAGING TORNADOES. THE LINE OF STORMS WILL CONTINUE EAST THIS EVENING AND EVENTUALLY RACE ACROSS OUR AREA LATE THIS EVENING INTO THE WEE HOURS OF MONDAY MORNING. INSTABILITY WILL AS USUAL BE LIMITED...BUT SHEAR IS EXTREMELY STRONG. WHILE THE 15Z HRRR AND LATEST WRF RUNS INDICATE A WEAKENING TREND AS THE LINE MOVES OUR WAY...IT STILL LOOKS GOOD FOR ISOLATED STRONG WIND GUSTS ALONG AND JUST AHEAD OF THE COLD FRONT. BEST TIME FRAME FOR THE WORST OF THE WEATHER OVERNIGHT LOOKS TO BE ABOUT 03-09Z WHEN THE BIGGEST PWATS AND LOW LEVEL WINDS SURGE THROUGH THE AREA. 850 WINDS ARE PROGGED IN THE 50-70KT RANGE...SOME 3-4STD ABOVE NORMAL. WE EXPECT THE LINE TO BRING BRIEF DOWNPOURS AND THE INITIAL BLAST OF STRONG AND POSSIBLY DAMAGING WIND GUSTS. THEN OVERALL GRADIENT WINDS SHOULD KICK IN AND GUST IN THE 25-45MPH RANGE FOR A TIME. SHORT RANGE OPERATIONAL MODELS ARE SHOWING A STRONG ISSALOBARIC SURGE BEHIND THE FRONT SUPPORTING THE IDEA OF GUSTY POST FRONTAL WINDS...AT LEAST THROUGH EARLY MONDAY MORNING WHEN THE STRONGEST WINDS SHOULD THEN SHIFT OFF TO OUR NORTH AND NORTHEAST. A WIND ADVISORY HAS BEEN ISSUED FOR LATER TONIGHT THROUGH EARLY MONDAY MORNING. && .SHORT TERM /MONDAY/... THE COLD FRONT SHOULD BE EXITING THE COASTAL PLAIN BY 12Z MONDAY...LEAVING PA IN A GUSTY WEST-SOUTHWEST FLOW. TEMPERATURES...AT LEAST INITIALLY WILL NOT BE ALL THAT COLD WITHIN THE NEW AIRMASS. ANY SHOWERS THAT DEVELOP AS THE COOLER AIR MOVES OVER THE GREAT LAKES WILL ONLY GRADUALLY MIX WITH WET SNOW BY THE END OF THE DAY OVER THE NW. THE BULK OF THE REST OF THE REGION WILL ENJOY THE DRY SLOT...AND DESPITE BEING RATHER WINDY WILL SEE HIGHS THAT WILL STILL AVERAGE SEVERAL DEG ABOVE NORMAL FOR NOVEMBER OVER ALL BUT THE FAR NW. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... SCATTERED LIGHT PRECIPITATION /INITIALLY IN THE FORM OF RAIN SHOWERS DURING THE DAYLIGHT HOURS MONDAY...THEN EVENTUALLY SNOW SHOWERS BY MONDAY NIGHT/...WILL AFFECT THE NORTHERN AND WESTERN MOUNTAINS OF THE STATE. MINOR SNOW ACCUMS OF A COATING...TO PERHAPS AROUND 1 INCH IN WARREN COUNTY...WILL OCCUR MONDAY NIGHT ACROSS THE MTNS. BIG NEGATING FACTOR AGAINST ACCUMULATING OROGRAPHIC/LES SNOW SHOWERS WILL BE THE RATHER SHALLOW DEPTH OF THE COLD AIR...AND CLOUD TEMPS WARMER THAN -12C WHICH WILL GREATLY LIMIT THE INTENSITY AND DENDRITIC GROWTH OF THE SNOW. AFTER PASSAGE OF UPPER TROF AXIS MONDAY/EARLY TUESDAY...THE UPPER FLOW PATTERN BECOMES FAIRLY ZONAL THROUGH THE REMAINDER OF THE PERIOD AS ENERGY IS FORECAST TO DIG INTO THE WESTERN U.S. 00Z MODEL GUIDANCE IS SOMEWHAT GOOD AGREEMENT ON A DRY AND SLOWLY MODERATING PERIOD FOR THE SECOND HALF OF THE WEEK AS HIGH PRESSURE SLIDES OFF THE SOUTHERN NEW ENGLAND COAST. AN ARCTIC FRONT WILL PLOW SOUTHEAST ACROSS THE NORTHERN PLAINS AND UPPER GLAKES FRIDAY...THANKS TO A HIGHLY AMPLIFIED RIDGE FORMING ACROSS THE ERN PACIFIC AND INTO THE GULF OF ALASKA...WITH AN EVENTUAL REX BLOCK PATTERN OVER THE WEST COAST OF CANADA AND THE U.S. INTERESTING SCENARIO SHAPING UP FOR NEXT WEEKEND WITH THE FIRST POTENTIAL FOR A WIDESPREAD SYNOPTIC LIGHT TO MODERATE SNOW OR MIXED PRECIP EVENT. 00Z GFS AND EC OPERATIONAL MODELS AND ENSEMBLE SUITES DIVERGE SLIGHTLY BY NEXT WEEKEND WITH THE TRACK/ORIENTATION OF THE ARCTIC FRONT...AND THE AMOUNT OF ENERGY DIGGING SOUTHEAST IN ITS WAKE INTO THE MISS VALLEY AND APPALACHIANS. HOWEVER...BOTH MODELS AND THEIR ENSEMBLES INDICATE A CLIPPER TYPE SYSTEM HEADING SE ACROSS THE GLAKES...BRINGING US AT LEAST SOME SNOW/OR SNOW SHOWERS /THAT COULD BE MIXED WITH RAIN ACROSS SOUTHERN PENN FRIDAY NIGHT INTO EARLY SAT/. THE COLDEST AIR SO FAR THIS FALL WILL LIKELY FOLLOW FOR LATER NEXT WEEKEND INTO THE WEEK OF NOV 25TH. && .AVIATION /17Z SUNDAY THROUGH THURSDAY/... WIDESPREAD REDUCED CIG/VIZ IN PLACE AT ALL TERMINALS EXCEPT JST WHICH IS ON THE EDGE OF THE LOWER CLOUDS AND VIZ ASSOCIATED WITH THE ADVANCING RAIN. RADAR TRENDS INDICATE THE NW 1/2-2/3RDS OF THE AIRSPACE WILL SEE SHOWERS INTO THE EVENING WITH WIDESPREAD IFR/MVFR CONTINUING TONIGHT WILL BE A VERY ACTIVE PERIOD WITH A STRONG COLD FRONT AND ATTENDANT LOW-TOPPED SQUALL LINE EXPECTED TO RACE EWD ACROSS THE AIRSPACE. SOUTHERLY WINDS WILL STEADILY INCREASE AHEAD OF THE FRONT WITH LLWS EXPECTED GIVEN 50+KT LOW LEVEL JET. MODERATE TO HEAVY SHOWERS AND LOCAL HIGHER WIND GUSTS WILL BE POSSIBLE ALONG AND IMMEDIATELY BEHIND THE SQUALL LINE WITH AN ABRUPT WIND SHIFT TO THE WEST- SOUTHWEST. GUSTY WINDS WILL CONTINUE INTO EARLY MONDAY WITH FQNT GUSTS IN THE 25-45MPH RANGE..ESPECIALLY OVER WESTERN AREAS. MONDAY WILL SEE RAPID IMPROVEMENT IN CEILING/VIZ AS THE FRONT MOVES OUT OF THE REGION...BUT SOME LOCALLY REDUCED CONDITIONS WILL BECOME POSSIBLE ONCE AGAIN OVER THE NW AS COOLER AIR BEGINS TO SWEEP OVER THE GR LAKES AND BRING SOME SCATTERED RAIN/SNOW SHOWERS. THE WIND WILL STAY GUSTY IN THE 20-35MPH RANGE...GRADUALLY DIMINISHING IN THE AFTERNOON. OUTLOOK... TUE...MAINLY VFR...LOCALLY MVFR OVER THE NW WITH SCATTERED SNOW SHOWERS. WED-THU...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 11 PM THIS EVENING TO 8 AM EST MONDAY FOR PAZ004>006-010>012-017>019-024-025-033-034-037-041-042-045-046. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
909 AM EST SUN NOV 17 2013 .SYNOPSIS... THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 9 AM...WESTWARD EXPANSION OF THE DENSE FOG APPEARS TO HAVE BEEN HALTED BY THE WARMING BOUNDARY LAYER NOW THAT THE SUN IS GETTING A BIT HIGHER IN THE SKY...AND SOME THIN SPOTS ARE BEGINNING TO APPEAR OVER THE PIEDMONT. HOWEVER...THE DENSE FOG ADVISORY RAN OUT AT 14Z AND CONDITIONS WILL IMPROVE ONLY SLOWLY...SO IT WAS EXTENDED THROUGH 16Z. TEMPS ARE IN DECENT SHAPE. EXPECT FREQUENT UPDATES THROUGH THIS AFTERNOON. PREVIOUS DISCUSSION... AS OF 545 AM EST SUNDAY...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR THE I-77 CORRIDOR. VSBYS HAVE BEEN STEADILY DECLINING AND A LARGE AREA OF THE WRN PIEDMONT IS NOW DOWN TO A QUARTER MILE. THE ADVISORY WAS RUN THROUGH 14 UTC. HOWEVER...THE LIGHT EASTERLY FLOW AND INCREASING WARM ADVECTION ALOFT MAY HELP THE FOG TO HANG AROUND MOST OF THE MORNING. AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING CHANCES OF SHOWER ACTIVITY OVER THE FORECAST AREA. SHOWER CHANCES WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEING FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING. LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE LOW. WHILE THE FORCING WILL BE STRONGER OVER WESTERN NC...THERE IS HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL WEAKEN CONSIDERABLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A WEAKENING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE NORMAL. THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL. THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH. UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY. HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A COMPROMISE FROM THE DAYS 5 TO 7 MODELS. THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY INTO SATURDAY. THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA. THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS. NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY. TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND SATURDAY. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... AT KCLT...CLEAR SKIES EARLIER IN THE NIGHT SET THE STAGE FOR DENSE FOG AT THE AIRFIELD. WITH WEAK WARM ADVECTION ALOFT...THIS IS THE KIND OF FOG EVENT WHICH COULD LAST MOST OF THE MORNING. FOR NOW I ONLY HAVE 1/4SM THROUGH 14 UTC AND 1/2SM TIL 15 UTC. THE DAY SHIFT MAY NEED TO EXTEND THAT A FEW HOURS. CIGS SHOULD GRADUALLY LIFT INTO THE AFTN BEFORE THEY FALL QUICKLY AGAIN THIS EVENING. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT AND GUSTY WINDS SHOULD ACCOMPANY BNDRY ACROSS THE AIRFIELD. A WIND SHIFT WAS NOT INCLUDED IN THIS ISSUANCE BUT BE AWARE THAT THE BNDRY IS EXPECTED TO ARRIVE RIGHT AROUND 12 UTC...OR POSSIBLY AN HOUR OR 2 BEFORE. ELSEWHERE...IFR OR LIFR CIGS HAVE DEVELOPED AT KHKY AND KAVL AND THE CIGS WILL BE SLOW TO LIFT. IN FACT BOTH THE CIGS AND VSBYS MAY BECOME WORSE OVER THE NEXT COUPLE HOURS. IFR CIGS WERE BEGINNING TO DEVELOP OVER THE UPSTATE A LITTLE BEFORE 12 UTC. BASED ON MODEL SOUNDINGS AND THE GENERAL SET UP THIS MORNING I EXPECT THAT IFR CIGS WILL SOON COVER ALL THE UPSTATE WITH IFR CONDITIONS LASTING THROUGH NOON. HOPEFULLY THERE WILL BE ENOUGH MIXING TO KEEP THE AREAS OF DENSE FOG EAST OF THE UPSTATE AIRFIELDS THIS MORNING. SCATTERED SHOWERS WILL BECOME MORE WIDESPREAD THIS AFTERNOON. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS BETWEEN 06-09 UTC. WINDS SHOULD SHIFT AT KAVL AROUND OR A LITTLE BEFORE 09 UTC. NOT SURE IF THE LINE WILL STILL BE PRODUCING LIGHTNING BY THE TIME IT HITS KAVL...BUT THERE SHOULD BE GUSTY NW WINDS. THE LINE SHOULD FURTHER WEAKEN AS IT MOVES OUT OF THE MTNS...BUT A SHARP WIND SHIFT IS LIKELY TO AFFECT ALL OF THE TAF SITES BETWEEN 09-12 UTC. OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY. CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE OF THE UPCOMING WEEK. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-14Z KCLT MED 63% HIGH 94% HIGH 87% HIGH 97% KGSP HIGH 86% HIGH 87% HIGH 100% HIGH 87% KAVL MED 75% HIGH 91% HIGH 87% HIGH 95% KHKY HIGH 91% HIGH 87% HIGH 96% HIGH 82% KGMU HIGH 86% MED 79% HIGH 100% HIGH 97% KAND HIGH 83% HIGH 87% HIGH 93% HIGH 82% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR NCZ033- 035>037-056-057-068>072-082-501>504. SC...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR SCZ009-014. && $$ SYNOPSIS...DEO NEAR TERM...MCAVOY/PM SHORT TERM...JAT LONG TERM...DEO AVIATION...MCAVOY FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
816 AM EST SUN NOV 17 2013 .SYNOPSIS... THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 8 AM...DENSE FOG CONTINUES TO OOZE ITS WAY WESTWARD TOWARD THE BLUE RIDGE. HAVE ADDED ANOTHER STRIPE OF ZONES TO THE DENSE FOG ADVISORY TO ACCOUNT FOR VISIBILITY DROPPING DOWN TO 1/4 MILE FROM GASTONIA TO LINCOLNTON AND HICKORY. INCLUDED THE AREA AROUND THE TABLE ROCK FIRE AS WELL. RADAR NOT DETECTING ANY PRECIP YET ACROSS THE WESTERN CAROLINAS...SO THE PRECIP CHANCES WERE PUSHED BACK A FEW HOURS TOWARD MIDDAY. TEMPS WERE ALSO ADJUSTED. EXPECT FREQUENT UPDATES TODAY. PREVIOUS DISCUSSION... AS OF 545 AM EST SUNDAY...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR THE I-77 CORRIDOR. VSBYS HAVE BEEN STEADILY DECLINING AND A LARGE AREA OF THE WRN PIEDMONT IS NOW DOWN TO A QUARTER MILE. THE ADVISORY WAS RUN THROUGH 14 UTC. HOWEVER...THE LIGHT EASTERLY FLOW AND INCREASING WARM ADVECTION ALOFT MAY HELP THE FOG TO HANG AROUND MOST OF THE MORNING. AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING CHANCES OF SHOWER ACTIVITY OVER THE FORECAST AREA. SHOWER CHANCES WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEING FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING. LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE LOW. WHILE THE FORCING WILL BE STRONGER OVER WESTERN NC...THERE IS HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL WEAKEN CONSIDERABLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A WEAKENING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE NORMAL. THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL. THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH. UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY. HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A COMPROMISE FROM THE DAYS 5 TO 7 MODELS. THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY INTO SATURDAY. THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA. THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS. NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY. TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND SATURDAY. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... AT KCLT...CLEAR SKIES EARLIER IN THE NIGHT SET THE STAGE FOR DENSE FOG AT THE AIRFIELD. WITH WEAK WARM ADVECTION ALOFT...THIS IS THE KIND OF FOG EVENT WHICH COULD LAST MOST OF THE MORNING. FOR NOW I ONLY HAVE 1/4SM THROUGH 14 UTC AND 1/2SM TIL 15 UTC. THE DAY SHIFT MAY NEED TO EXTEND THAT A FEW HOURS. CIGS SHOULD GRADUALLY LIFT INTO THE AFTN BEFORE THEY FALL QUICKLY AGAIN THIS EVENING. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT AND GUSTY WINDS SHOULD ACCOMPANY BNDRY ACROSS THE AIRFIELD. A WIND SHIFT WAS NOT INCLUDED IN THIS ISSUANCE BUT BE AWARE THAT THE BNDRY IS EXPECTED TO ARRIVE RIGHT AROUND 12 UTC...OR POSSIBLY AN HOUR OR 2 BEFORE. ELSEWHERE...IFR OR LIFR CIGS HAVE DEVELOPED AT KHKY AND KAVL AND THE CIGS WILL BE SLOW TO LIFT. IN FACT BOTH THE CIGS AND VSBYS MAY BECOME WORSE OVER THE NEXT COUPLE HOURS. IFR CIGS WERE BEGINNING TO DEVELOP OVER THE UPSTATE A LITTLE BEFORE 12 UTC. BASED ON MODEL SOUNDINGS AND THE GENERAL SET UP THIS MORNING I EXPECT THAT IFR CIGS WILL SOON COVER ALL THE UPSTATE WITH IFR CONDITIONS LASTING THROUGH NOON. HOPEFULLY THERE WILL BE ENOUGH MIXING TO KEEP THE AREAS OF DENSE FOG EAST OF THE UPSTATE AIRFIELDS THIS MORNING. SCATTERED SHOWERS WILL BECOME MORE WIDESPREAD THIS AFTERNOON. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS BETWEEN 06-09 UTC. WINDS SHOULD SHIFT AT KAVL AROUND OR A LITTLE BEFORE 09 UTC. NOT SURE IF THE LINE WILL STILL BE PRODUCING LIGHTNING BY THE TIME IT HITS KAVL...BUT THERE SHOULD BE GUSTY NW WINDS. THE LINE SHOULD FURTHER WEAKEN AS IT MOVES OUT OF THE MTNS...BUT A SHARP WIND SHIFT IS LIKELY TO AFFECT ALL OF THE TAF SITES BETWEEN 09-12 UTC. OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY. CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE OF THE UPCOMING WEEK. CONFIDENCE TABLE... 13-19Z 19-01Z 01-07Z 07-13Z KCLT MED 68% HIGH 89% MED 76% HIGH 94% KGSP HIGH 81% HIGH 91% HIGH 90% HIGH 87% KAVL MED 64% HIGH 91% HIGH 85% HIGH 88% KHKY HIGH 91% HIGH 91% HIGH 85% HIGH 82% KGMU HIGH 81% HIGH 83% HIGH 93% HIGH 96% KAND MED 77% HIGH 91% HIGH 85% HIGH 83% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ033- 035>037-056-057-068>072-082-501>504. SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ009-014. && $$ SYNOPSIS...DEO NEAR TERM...MCAVOY/PM SHORT TERM...JAT LONG TERM...DEO AVIATION...MCAVOY FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
646 AM EST SUN NOV 17 2013 .SYNOPSIS... THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 545 AM EST SUNDAY...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR THE I-77 CORRIDOR. VSBYS HAVE BEEN STEADILY DECLINING AND A LARGE AREA OF THE WRN PIEDMONT IS NOW DOWN TO A QUARTER MILE. THE ADVISORY WAS RUN THROUGH 14 UTC. HOWEVER...THE LIGHT EASTERLY FLOW AND INCREASING WARM ADVECTION ALOFT MAY HELP THE FOG TO HANG AROUND MOST OF THE MORNING. AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING CHANCES OF SHOWER ACTIVITY OVER THE FORECAST AREA. SHOWER CHANCES WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEING FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING. LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE LOW. WHILE THE FORCING WILL BE STRONGER OVER WESTERN NC...THERE IS HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL WEAKEN CONSIDERABLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A WEAKENING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE NORMAL. THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL. THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH. UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY. HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A COMPROMISE FROM THE DAYS 5 TO 7 MODELS. THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY INTO SATURDAY. THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA. THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS. NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY. TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND SATURDAY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AT KCLT...CLEAR SKIES EARLIER IN THE NIGHT SET THE STAGE FOR DENSE FOG AT THE AIRFIELD. WITH WEAK WARM ADVECTION ALOFT...THIS IS THE KIND OF FOG EVENT WHICH COULD LAST MOST OF THE MORNING. FOR NOW I ONLY HAVE 1/4SM THROUGH 14 UTC AND 1/2SM TIL 15 UTC. THE DAY SHIFT MAY NEED TO EXTEND THAT A FEW HOURS. CIGS SHOULD GRADUALLY LIFT INTO THE AFTN BEFORE THEY FALL QUICKLY AGAIN THIS EVENING. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT AND GUSTY WINDS SHOULD ACCOMPANY BNDRY ACROSS THE AIRFIELD. A WIND SHIFT WAS NOT INCLUDED IN THIS ISSUANCE BUT BE AWARE THAT THE BNDRY IS EXPECTED TO ARRIVE RIGHT AROUND 12 UTC...OR POSSIBLY AN HOUR OR 2 BEFORE. ELSEWHERE...IFR OR LIFR CIGS HAVE DEVELOPED AT KHKY AND KAVL AND THE CIGS WILL BE SLOW TO LIFT. IN FACT BOTH THE CIGS AND VSBYS MAY BECOME WORSE OVER THE NEXT COUPLE HOURS. IFR CIGS WERE BEGINNING TO DEVELOP OVER THE UPSTATE A LITTLE BEFORE 12 UTC. BASED ON MODEL SOUNDINGS AND THE GENERAL SET UP THIS MORNING I EXPECT THAT IFR CIGS WILL SOON COVER ALL THE UPSTATE WITH IFR CONDITIONS LASTING THROUGH NOON. HOPEFULLY THERE WILL BE ENOUGH MIXING TO KEEP THE AREAS OF DENSE FOG EAST OF THE UPSTATE AIRFIELDS THIS MORNING. SCATTERED SHOWERS WILL BECOME MORE WIDESPREAD THIS AFTERNOON. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS BETWEEN 06-09 UTC. WINDS SHOULD SHIFT AT KAVL AROUND OR A LITTLE BEFORE 09 UTC. NOT SURE IF THE LINE WILL STILL BE PRODUCING LIGHTNING BY THE TIME IT HITS KAVL...BUT THERE SHOULD BE GUSTY NW WINDS. THE LINE SHOULD FURTHER WEAKEN AS IT MOVES OUT OF THE MTNS...BUT A SHARP WIND SHIFT IS LIKELY TO AFFECT ALL OF THE TAF SITES BETWEEN 09-12 UTC. OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY. CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE OF THE UPCOMING WEEK. CONFIDENCE TABLE... 11-17Z 17-23Z 23-05Z 05-11Z KCLT LOW 54% HIGH 87% MED 74% HIGH 82% KGSP HIGH 80% HIGH 93% HIGH 81% HIGH 93% KAVL LOW 57% HIGH 96% HIGH 84% HIGH 80% KHKY HIGH 88% HIGH 100% MED 78% HIGH 84% KGMU MED 78% HIGH 87% HIGH 81% HIGH 97% KAND MED 66% HIGH 96% MED 74% HIGH 88% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ036-037- 057-071-072-082. SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ009-014. && $$ SYNOPSIS...DEO NEAR TERM...MCAVOY SHORT TERM...JAT LONG TERM...DEO AVIATION...MCAVOY FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
631 AM EST SUN NOV 17 2013 .SYNOPSIS... THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 545 AM EST SUNDAY...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR THE I-77 CORRIDOR. VSBYS HAVE BEEN STEADILY DECLINING AND A LARGE AREA OF THE WRN PIEDMONT IS NOW DOWN TO A QUARTER MILE. THE ADVISORY WAS RUN THROUGH 14 UTC. HOWEVER...THE LIGHT EASTERLY FLOW AND INCREASING WARM ADVECTION ALOFT MAY HELP THE FOG TO HANG AROUND MOST OF THE MORNING. AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING CHANCES OF SHOWER ACTIVITY OVER THE FORECAST AREA. SHOWER CHANCES WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEING FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING. LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE LOW. WHILE THE FORCING WILL BE STRONGER OVER WESTERN NC...THERE IS HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL WEAKEN CONSIDERABLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A WEAKENING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE NORMAL. THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL. THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH. UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY. HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A COMPROMISE FROM THE DAYS 5 TO 7 MODELS. THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY INTO SATURDAY. THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA. THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS. NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY. TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND SATURDAY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AT KCLT...SKIES HAVE CLEARED TEMPORARILY AT THE AIRFIELD. JUST A FEW MILES TO THE WEST THERE IS AN BORDERLINE MVFR/VFR DECK. JUST A FEW MILES TO THE EAST THERE IS AN EXPANDING AREA OF FOG AND IFR/LIFR STRATUS AND FOG. BASED ON THE H8 DRYING SEEN ON THE LATEST NAM AND RUC...WENT WITH TEMPO IFR VSBYS AND LIFR CIGS. ONCE A HIGHER DECK FINALLY SPREADS BACK IN HOPEFULLY THE LOWER STUFF WILL LIFT FOR A WHILE. THAT SAID...IFR CIGS ARE EXPECTED TO DEVELOP AGAIN TOWARD 12 UTC AND LAST THROUGH THE MORNING. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE MORNING HOURS. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT AND GUSTY WINDS MAY ACCOMPANY THE OUTFLOW BNDRY TOWARD MONDAY MORNING. THIS IS A LITTLE OUTSIDE THE VALID PERIOD OF THE TAF...BUT IT/S SOMETHING TO WATCH CLOSELY. ELSEWHERE...VFR CIGS ARE CURRENTLY OVER ALL THE REMAINING TAF SITES. STRENGTHENING UPSLOPE FLOW WILL HELP THESE CIGS TO GRADUALLY LOWER DURING THE NIGHT. EXPECT THAT AN MVFR CIG WILL DEVELOP FIRST AROUND 2500 FEET WITH IFR STRATUS DEVELOPING TOWARD MORNING. THE LOW CIGS ARE THEN EXPECTED TO LAST A LITTLE PAST NOON. SHOWERS WILL BECOME MORE WIDESPREAD THIS EVENING. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS BETWEEN 06-09 UTC. THE LINE MAY AFFECT KAVL. EVEN IF THE STORMS WEAKEN...A SHARP WIND SHIFT IS LIKELY TO AFFECT ALL OF THE TAF SITES A LITTLE BEYOND THE VALID PERIOD OF THE CURRENT SET OF TAFS. OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY. CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE OF THE UPCOMING WEEK. CONFIDENCE TABLE... 11-17Z 17-23Z 23-05Z 05-11Z KCLT LOW 54% HIGH 87% MED 74% HIGH 82% KGSP HIGH 80% HIGH 93% HIGH 81% HIGH 93% KAVL LOW 57% HIGH 96% HIGH 84% HIGH 80% KHKY HIGH 88% HIGH 100% MED 78% HIGH 84% KGMU MED 78% HIGH 87% HIGH 81% HIGH 97% KAND MED 66% HIGH 96% MED 74% HIGH 88% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ036-037- 057-071-072-082. SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ009-014. && $$ SYNOPSIS...DEO NEAR TERM...MCAVOY SHORT TERM...JAT LONG TERM...DEO AVIATION...MCAVOY FIRE WEATHER...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
250 AM EST SUN NOV 17 2013 .SYNOPSIS... THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING CHANCES OF SHOWER ACTIVITY OVER THE FOREAST AREA. SHOWER CHANCES WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEGING FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING. LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE LOW. WHILE THE FORECING WILL BE STRONGER OVER WESTERN NC...THERE IS HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL WEAKEN CONSIDERLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A WEAKING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE NORMAL. THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL. THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH. UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY. HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A COMPROMISE FROM THE DAYS 5 TO 7 MODELS. THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY INTO SATURDAY. THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA. THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS. NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY. TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND SATURDAY. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... AT KCLT...SKIES HAVE CLEARED TEMPORARILY AT THE AIRFIELD. JUST A FEW MILES TO THE WEST THERE IS AN BORDERLINE MVFR/VFR DECK. JUST A FEW MILES TO THE EAST THERE IS AN EXPANDING AREA OF FOG AND IFR/LIFR STRATUS AND FOG. BASED ON THE H8 DRYING SEEN ON THE LATEST NAM AND RUC...WENT WITH TEMPO IFR VSBYS AND LIFR CIGS. ONCE A HIGHER DECK FINALLY SPREADS BACK IN HOPEFULLY THE LOWER STUFF WILL LIFT FOR A WHILE. THAT SAID...IFR CIGS ARE EXPECTED TO DEVELOP AGAIN TOWARD 12 UTC AND LAST THROUGH THE MORNING. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE MORNING HOURS. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT AND GUSTY WINDS MAY ACCOMPANY THE OUTFLOW BNDRY TOWARD MONDAY MORNING. THIS IS A LITTLE OUTSIDE THE VALID PERIOD OF THE TAF...BUT IT/S SOMETHING TO WATCH CLOSELY. ELSEWHERE...VFR CIGS ARE CURRENTLY OVER ALL THE REMAINING TAF SITES. STRENGTHENING UPSLOPE FLOW WILL HELP THESE CIGS TO GRADUALLY LOWER DURING THE NIGHT. EXPECT THAT AN MVFR CIG WILL DEVELOP FIRST AROUND 2500 FEET WITH IFR STRATUS DEVELOPING TOWARD MORNING. THE LOW CIGS ARE THEN EXPECTED TO LAST A LITTLE PAST NOON. SHOWERS WILL BECOME MORE WIDESPREAD THIS EVENING. A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS BETWEEN 06-09 UTC. THE LINE MAY AFFECT KAVL. EVEN IF THE STORMS WEAKEN...A SHARP WIND SHIFT IS LIKELY TO AFFECT ALL OF THE TAF SITES A LITTLE BEYOND THE VALID PERIOD OF THE CURRENT SET OF TAFS. OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY. CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE OF THE UPCOMING WEEK. CONFIDENCE TABLE... 07-13Z 13-19Z 19-01Z 01-07Z KCLT LOW 59% MED 73% MED 79% MED 75% KGSP MED 72% MED 69% HIGH 83% HIGH 90% KAVL HIGH 94% MED 77% HIGH 85% HIGH 91% KHKY HIGH 86% HIGH 82% HIGH 88% HIGH 93% KGMU MED 71% MED 67% MED 77% HIGH 86% KAND MED 65% MED 63% HIGH 85% HIGH 86% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...DEO NEAR TERM...MCAVOY SHORT TERM...JAT LONG TERM...DEO AVIATION...MCAVOY FIRE WEATHER...MCAVOY
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
554 AM CST SUN NOV 17 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 412 AM CST SUN NOV 17 2013 ON THE BIG PICTURE EARLY THIS MORNING...DEEP TROUGH THROUGH THE PLAINS STATES WITH STRONG JET ENERGY JET GETTING READY TO BOTTOM OUT AND SWING NORTHEAST THROUGH THE OHIO VALLEY TODAY. MAIN SURFACE LOW PRESSURE STARTING TO WIND UP ACROSS NORTHEAST KANSAS...WITH REFLECTION OF UPPER TROUGH EXTENDING BACK INTO SOUTHWEST SOUTH DAKOTA. LEADING WAVE LIFTING/WEAKENING THROUGH NORTHERN MINNESOTA... WITH BACKWASH OF STRATUS ACROSS NORTHERN MINNESOTA/EASTERN NORTH DAKOTA...EXTENDING INTO EAST CENTRAL SOUTH DAKOTA. SMALLER POCKET OF STRATUS/FOG SLIPPING SOUTHWARD TOWARD KFSD AREA ALONG I29...WITH EVEN A FEW 1/4 TO 1/2SM VISIBILITIES NOTED ALONG LEADING EDGE. MANY SUBTLE ELEMENTS TO FORECAST OVER THE NEXT 12 TO 24 HOURS... BUT FOR THE MOST PART WILL BE SPARED BY ANYTHING TOO SIGNIFICANT AS UPPER TROUGH SLIPS THROUGH THE REGION EARLY TODAY. MAIN UPPER ENERGY FOCUSED WELL SOUTH OF THE AREA TODAY...HOWEVER... WILL HAVE PERIOD OF DECENT DIV Q AND PV ADVECTION FOR MAINLY SOUTHEASTERN CWA THROUGH THE MID TO LATE MORNING HOURS. AREA OF LIGHT RAINFALL WILL MOVE OUT OF NEBRASKA AND CONTINUE TO EXPAND ACROSS SOUTHERN PORTIONS OF NORTHWEST IOWA IN PREDAWN HOURS. HIGH RESOLUTION MODEL SOLUTIONS SUPPORT A HIGHER POP/LOWER QPF SCENARIO AS BAND WORKS EASTWARD EARLY THIS MORNING...SO BUMPED POPS UP TO A BRIEF PERIOD OF LIKELY IN FAR SOUTHERN/SOUTHEASTERN CWA... MAINLY TIMED ALONG WITH MID LEVEL FRONTAL BOUNDARY WHICH DOES HAVE ENOUGH NEUTRALITY TO STABILITY FIELDS TO SUPPORT CONTRACTING BAND OF PRECIP THIS MORNING. THIS AREA SHOULD BE PRIMARILY OUT OF THE CWA BY VERY LATE MORNING. MEANWHILE...LIGHT PRECIP CURRENTLY ACROSS WESTERN SOUTH DAKOTA INDICATIVE OF THE LIFT FORCING WITH SECONDARY ENERGY COMING OUT OF WYOMING. THIS PRECIP SHOULD APPROACH SOUTH CENTRAL SOUTH DAKOTA LOCATIONS BY MID MORNING. FORTUNATELY... TEMPERATURES SHOULD BE INCREASING BACK ABOVE FREEZING AS PRECIP MOVES IN...AND ALSO THE OVERALL FORCING WILL START TO DIMINISH SOME AS WORK INTO THE AFTERNOON HOURS...LIMITING COVERAGE AND INTENSITY TO TRAILING PRECIP. THIS ROUND OF DYNAMICS HAS MORE FOCUS TOWARD THE MISSOURI VALLEY...AND SHIFTED THE LOWER POP THREAT FOR THIS PRECIPITATION SOUTHWARD FROM EARLIER FORECAST. OTHER GOOD NEWS IS THAT THE OVERALL WIND GRADIENT SHOULD NOT BE QUITE AS STRONG AS MODELS INDICATED THIS TIME YESTERDAY...AND THIS SHOULD KEEP WINDS SPEEDS FROM REACHING ADVISORY CRITERIA DURING THE LATER MORNING AND AFTERNOON. LIKELY TO GET A FEW 35-40 MPH GUSTS THROUGH THE MISSOURI RIVER CORRIDOR...ESPECIALLY TOWARD LOWER BRULE AREAS. AS GO INTO TONIGHT...GRADIENT WILL START TO GRADUALLY DIMINISH... SOMEWHAT QUICKER IN WESTERN AREAS DURING THE EVENING. SKIES WILL ALSO TREND TOWARD MORE CLEARING SOUTH AND WEST...AS NORTHWEST FLOW CONTINUES TO DUMP STRATUS THROUGH THE NORTHEAST HALF OF THE AREA OVERNIGHT. QUITE A BIT OF SUBSIDENCE INDICATED WHICH SHOULD START TO MAKE AREA MORE RAGGED BY VERY LATE NIGHT. TEMPS WILL COOL ACCORDINGLY...WITH THE WEAKER GRADIENT IN THE WEST AND DRY AIR IN RIDGE FOR SOME UPPER TEENS...WITH MAINLY LOWER TO MID 20S ELSEWHERE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 412 AM CST SUN NOV 17 2013 WE SEE A RETURN TO SOUTHERLY FLOW AND WARMING ALOFT ON MONDAY...SETTING UP A MILD DAY. IN A SIMILAR TYPE PATTERN THIS PAST WEEK THE WARMEST GUIDANCE WAS THE WAY TO GO...SO KEPT THAT TREND GOING WITH HIGHS IN THE 40S AND 50S. THE UNSEASONABLE WARMTH WILL CONTINUE INTO TUESDAY...WITH ANOTHER DAY OF READINGS IN THE 50S. WILL LIKELY SEE INCREASING HIGH AND MID CLOUDS THROUGH THE DAY AS AN UPPER WAVE MOVES ACROSS THE AREA. THESE CLOUDS MAY TEMPER THE WARMING SOMEWHAT SO DID NOT WANT TO GO TOO HIGH...ALTHOUGH IF CLOUDS END UP THINNER OR LESS WIDESPREAD...TEMPERATURES WOULD PROBABLY END UP A FEW DEGREES WARMER THAN CURRENTLY FORECAST. TUESDAY NIGHT WILL BE A RELATIVELY MILD ONE WITH LOWS IN THE 30S AND 40S...WITH CLOUD COVER AND A SOUTHERLY BREEZE OUT AHEAD OF OUR NEXT COLD FRONT. PRETTY GOOD AGREEMENT ON THE COLD FRONT COMING ACROSS WEDNESDAY MORNING. COLD AIR ALOFT LAGS THE SURFACE FRONT A BIT...WHICH COMBINED WITH INCREASED MIXING BEHIND THE FRONT...WILL LEAD TO ANOTHER MILD DAY...ESPECIALLY ACROSS OUR EAST. THUS WENT AHEAD AND RAISED HIGHS SOME OVER NORTHWEST IOWA AND PORTIONS OF SOUTHWEST MINNESOTA. OVERALL EXPECTING 50S THERE...WITH 40S OVER THE NORTHWEST HALF OF THE AREA. SEEMS LIKE WE WOULD SEE FALLING TEMPERATURES BY AFTERNOON AS THE STRONG COLD AIR ADVECTION KICKS IN. MODELS THEN BEGIN TO DIVERGE WEDNESDAY NIGHT INTO THE END OF THE WEEK. A COMPLEX PATTERN WITH THE COLD AIRMASS ASSOCIATED WITH THE NORTHERN STREAM WAVE INTERACTING WITH SOUTHERN STREAM ENERGY COMING INTO CALIFORNIA FROM THE PACIFIC. A LARGE SPREAD IN THE OPERATIONAL MODELS AND GFS ENSEMBLES CONFIRM THAT THIS IS A LOW PREDICTABILITY TYPE OF PATTERN. THE ECMWF IS MOST AGGRESSIVE WITH THE NORTHERN STREAM WAVE...PUSHING COLD AND DRY AIR INTO OUR REGION THURSDAY INTO FRIDAY. WHILE THE GFS AND GEM ARE NOT QUITE AS AGGRESSIVE...AND RIDE SOME OF THE SOUTHERN STREAM ENERGY OVER THE BAROCLINIC ZONE RESULTING IN A PERIOD OF PRECIPITATION FOR US SOMETIME THURSDAY INTO FRIDAY MORNING. GFS ENSEMBLES OFFER A WIDE ARRAY OF SOLUTIONS...RANGING FROM A MORE COLD AND DRY ECMWF LIKE SOLUTION...TO A MUCH FURTHER NORTH...MORE PHASED AND WARMER SOLUTION. CANT SEE MUCH REASON TO FAVOR ONE IDEA OVER ANOTHER AT THIS POINT...SO WILL JUST CONTINUE TO MONITOR TRENDS OVER THE COMING DAYS....NOTING THE POTENTIAL FOR AT LEAST A LIGHT PRECIPITATION EVENT IN THIS TIME FRAME. WOULD SEEM LIKE WE WOULD TEND TO BE DRY ON SATURDAY WITH HIGH PRESSURE BUILDING IN AND ANOTHER POTENTIAL ARCTIC FRONT DIVING SOUTH OUT OF CANADA. MODELS AGAIN JUMPING ALL OVER THE PLACE WITH REGARDS TO WHETHER THIS COLD SHOT DIVES INTO THE PLAINS...OR FURTHER EAST INTO THE GREAT LAKES REGION. SO OVERALL...CONSENSUS TEMPERATURE GUIDANCE WAS PRETTY MUCH ACCEPTED FROM THURSDAY INTO SATURDAY UNTIL MODEL AGREEMENT AND RUN TO RUN CONSISTENCY INCREASES. TEMPERATURES SHOULD TEND TO RUN BELOW NORMAL THIS PERIOD THOUGH...WITH CURRENT CONSENSUS GIVING HIGHS IN THE 20S AND 30S AND LOWS IN THE TEENS AND 20S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 554 AM CST SUN NOV 17 2013 VERY COMPLEX AVIATION FORECAST THIS MORNING. STRATUS FIELD OBSCURED FROM VIEW BY HIGHER LEVEL CLOUDS THIS MORNING...MAKING IT DIFFICULT TO DIAGNOSE COVERAGE OF LOWER CLOUDS/FOG. OBSERVATIONS INDICATE THERE IS SOME DENSE FOG ALONG THE WESTERN LEADING EDGE OF AREA...MAINLY THROUGH THE JAMES VALLEY...INCLUDING THE KHON TAF. THESE CONDITIONS SHOULD NOT LAST LONG...AND HAVE REFLECTED A SOMEWHAT MORE OPTIMISTIC START WITH 12Z TAF. HRRR HAS PROVIDED SOME ADEQUATE GUIDANCE AS TO SPREAD OF LOWER CEILINGS...AND INDICATED THAT MUCH OF THE LIFR CEILINGS SHOULD START TO DIMINISH BY 16Z TO 17Z. QUESTIONS REMAIN IF ANY WILL BE ABLE TO PUSH SOUTH INTO KSUX AREA BEFORE MORE MIXY ENVIRONMENT SETS UP AND STRONGER SUBSIDENCE ERODES ADVANCING CLOUDS. WINDS WILL GUST 25 TO 30 KNOTS THROUGH THE AFTERNOON HOURS...BEFORE DIMINISHING THIS EVENING. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHAPMAN LONG TERM...CHENARD AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
205 PM CST SUN NOV 17 2013 .DISCUSSION... IN THE SHORT TERM...CLOUDY SKIES HANGING ON TOUGH ACROSS THE EAST AND SOUTH WITH THE LOW LEVEL MOISTURE AXIS. TO THE NORTH AND WEST MIDLEVEL DRY HAS SURGED AHEAD OF THE FRONTAL BOUNDARY AND HAS PROVIDED MOSTLY CLEAR SKIES AND GOOD MIXING IN THE BOUNDARY LAYER BUT LIKELY CAPPED JUST ABOVE. AS OF 20Z THE COLD FRONT/DRYLINE IS NOW CROSSING LAWRENCE AND RANDOLPH COUNTIES WITH CONVECTION REALLY STRUGGLING TO GET GOING DESPITE THE CLEARING AND DEWPOINTS NEAR 70F. WITH THIS SAID...THE NAM...GFS AND HRRR MODELS SHOW THE FRONT BECOMING SOMEWHAT MORE ACTIVE ACROSS NORTHWEST TENNESSEE BETWEEN 21-00Z. THIS STILL SEEMS VERY CONDITIONAL AND ISOLATED AS MAX TEMPERATURES WILL START TO FALL. WILL BE TRIMMING BACK THE CURRENT TORNADO WATCH BY 4 PM FOR THE COUNTIES WEST OF THE RIVER. FURTHER SOUTH...FEEL RAIN SHOWERS WILL BE MORE LIKELY ESPECIALLY THIS EVENING AS THE TAIL OF THE FRONT PASSES THROUGH NORTHEAST MISSISSIPPI. THE SOUTHWEST DELTA COUNTIES WILL HAVE THE LOWEST RAIN CHANCES FOR THE REMAINDER OF THE DAY. SKIES WILL CLEAR OUT ACROSS THE SOUTH DURING THE NIGHT WITH SOME PATCHY FOG POSSIBLE. MONDAY THROUGH WEDNESDAY...SURFACE HIGH PRESSURE WILL KEEP THE MIDSOUTH DRY WITH NEAR SEASONAL TEMPERATURES. WINDS WILL VEER FROM NORTH ON MONDAY TO SOUTHEASTERLY ON WEDNESDAY. LOWS TUESDAY AND WEDNESDAY MORNING WILL BE NEAR FREEZING OVER THE NORTH AND EAST. WEDNESDAY NIGHT THROUGH SUNDAY...GFS AND ECMWF BECOMING MORE IN LINE DURING THIS PERIOD THAT WAA AND ISENTROPIC LIFT WILL GENERATE LIGHT RAIN SHOWER ACTIVITY ACROSS THE MIDWEST FIRST...AND THEN EXTEND IT SOUTHWARD ON THURSDAY. THIS IS IN RESPONSE TO A DESCENDING 1040MB SURFACE HIGH IN THE NORTHERN PLAINS...AS IT GENERATES A NEW COLD FRONT OVER THE MIDWEST. THIS BOUNDARY IS FORECASTED TO SLOWLY PUSH SOUTH THROUGH OUR AREA THURSDAY NIGHT THROUGH FRIDAY AND INTO EARLY SATURDAY. THUS THE END OF THE WORK WEEK LOOKS TO BE COOL AND WET. THOUGH WITH THE LACK OF ANY SIGNIFICANT UPPER LEVEL SUPPORT THUNDERSTORMS WILL BE MINIMAL. AS THE FRONT MOVES TOWARDS THE GULF COAST ON SATURDAY...NORTH WINDS WILL KEEP THE WEEKEND HIGHS TEN TO FIFTEEN DEGREES BELOW NORMAL...WITH MAINLY 40S TO LOW 50S. JAB && .AVIATION... A MID LEVEL DRY SLOT WILL CONTINUE TO ROTATE NORTHEASTWARD INTO NORTHERN PORTIONS OF THE MID SOUTH HELPING TO MIX OUT LOW LEVEL STRATUS. THIS SHOULD BE COMMON WITHIN THE NEXT FEW HOURS AT KJBR...KMKL...AND KMEM WITH CIGS EVENTUALLY GOING VFR. FURTHER SOUTH...LOW LEVEL MOISTURE AXIS WILL LIKELY MAINTAIN A LONGER TIME PERIOD WITH IFR TO MVFR CIGS PERSISTING THROUGH MUCH OF THE AFTERNOON. SHOWER AND THUNDERSTORMS POTENTIAL REMAINS MUCH MORE CONDITIONAL ACROSS OUR REGION THIS AFTERNOON AND THIS EVENING. BEST POTENTIAL WILL REMAIN ACROSS OUR NORTHERN TIER COUNTIES WITH THE BEST POTENTIAL AT KMKL WHERE A TEMPO HAS BEEN MAINTAINED FOR LATER THIS AFTERNOON. THIS WILL BE MONITORED THROUGH THE DAY AS TEMPO COVERAGE MAY STILL BE TOO HIGH. FOR NOW...HAVE KEPT A VICINITY THUNDER MENTION AT KMEM AND KJBR. AGAIN MAY NEED TO PULL THIS WITHIN THE NEXT FEW HOURS AS BEST LIFT REMAINS NORTH. STRONG AND GUSTY SOUTHWEST WINDS WILL BE LIKELY AT ALL TERMINALS THROUGH THE EARLY EVENING HOURS. THE FRONT WILL COME ACROSS THE TERMINALS FROM WEST TO EAST THIS EVENING WITH SKIES CLEARING AND WINDS BECOMING NORTHWESTERLY AND WEAKENING AS HIGH PRESSURE BUILDS IN. LATER TONIGHT CLEAR SKIES AND DIMINISHED WINDS ARE EXPECTED AND WILL CONTINUE THROUGH MID DAY MONDAY. JLH && .PRELIMINARY POINT TEMPS/POPS... MEM 49 63 41 59 / 20 0 0 0 MKL 43 62 35 57 / 20 0 0 0 JBR 43 61 36 55 / 10 0 0 0 TUP 48 66 38 60 / 40 0 0 0 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR DUNKLIN-PEMISCOT. MS...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ALCORN-BENTON MS- CALHOUN-COAHOMA-DESOTO-LAFAYETTE-MARSHALL-PANOLA-PONTOTOC- QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TUNICA-UNION-YALOBUSHA. TN...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1216 PM CST SUN NOV 17 2013 .MESOSCALE UPDATE... REGIONAL RADAR IMAGERY IS SHOWING AN INTENSE LINE OF SEVERE/TORNADIC THUNDERSTORMS EXTENDING SOUTHWARD FROM NORTHERN IL INTO SOUTHEAST MO. THIS LINE IS DEVELOPING JUST AHEAD OF A STRONG COLD FRONT...WHICH ALSO HAS A THINNER LINE OF STORMS ALONG IT...FURTHER WEST TOWARDS THE IA/IL BORDER. THE INITIAL LINE OF STORMS COULD CONTINUE TO FILL IN SOUTHWARD. A RUC SOUNDING FROM THE BOOTHEEL OF MO SHOWS PLENTY OF CAPE (WELL OVER 1000 J/KG) OVER THE NEXT FEW HOURS. ONLY CONCERN FOR STORMS NOT CONTINUING TO BUILD SOUTHWARD ALONG THE PRE-FRONTAL LINE WOULD BE A LITTLE WARMING FORECAST IN THE NAM/GFS MODELS AROUND 800MB WHICH COULD CAP OUR REGION AHEAD OF THE FRONT. GOOD LOW-LEVEL MOISTURE CONVERGENCE NEAR THE TN/MO/AR BORDER THOUGH COULD OVERCOME THAT. WILL HAVE TO MONITOR OVER THE NEXT COUPLE OF HOURS...BUT THAT WAS THE REASON FOR THE TOR WATCH BEING ISSUED TO OUR WEST. IF STORMS DO IN FACT CONTINUE TO BUILD SOUTH...THE LINE SHOULD BE THINNER AND LESS POTENT THAN THE INTENSE STORMS ACROSS THE LOWER GREAT LAKES REGION AT THE MOMENT (AS EVIDENCED BY ACTIVITY OVER NE AR FORMING NOW). YET THESE STORMS COULD STILL POSE THE DAMAGING WIND/ISOLATED TORNADO THREAT HERE MOST LIKELY AFTER 3PM OVER OUR FAR WESTERN COUNTIES. && .OHX WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR TNZ009>011-028>034- 062>066-075-077>080. WIND ADVISORY UNTIL 10 PM CST THIS EVENING FOR TNZ005>008- 022>027-056>061-093>095. && $$ AL
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1050 AM CST SUN NOV 17 2013 .UPDATE... UPDATED FOR TORNADO WATCH. && .DISCUSSION... TORNADO WATCH THROUGH 7 PM LST NORTH OF A HARRISBURG ARKANSAS TO HUNTINGDON TENNESSEE LINE. CURRENT DRY LINE ACROSS NORTH CENTRAL ARKANSAS AND SOUTH CENTRAL MISSOURI WILL LIKELY BECOME MORE ATICVE OVER THE NEXT FEW HOURS AS IT PUSHES TOWARDS THE MS RIVER. A FEW OF THESE STORMS MAY BECOME SEVERE WITH DAMAGING WINDS AND A POSSIBLE BRIEF TORNADO. HAVE ADJUSTED THE HWO ACCORDINGLY. JAB && .PREV DISCUSSION... /ISSUED 944 AM CST SUN NOV 17 2013/ UPDATE... UPDATED TO REDUCE MORNING AND AFTERNOON RAIN CHANCES AND TO ADJUST SEVERE WEATHER WORDING. DISCUSSION... FIRST...CONVECTION WITH THE LOW LEVEL INSTABILITY AXIS MOVING FASTER EAST THAN PREVIOUSLY FORECASTED...SO HAVE ADJUSTED RAIN CHANCES ACCORDINGLY FOR THE REMAINDER OF THE MORNING. SECOND...AFTER ANALYSIS OF THE HRRR MODEL...CURRENT SIGNIFICANT MIXING IN THE OBSERVATIONS AHEAD OF THE FRONT IN NORTHWEST ARKANSAS...AND STRONG CAP DEVELOPING AHEAD OF THE FRONT OFF OF 12Z SGF SOUNDING...IT APPEARS THAT THE SEVERE THREAT WILL REMAIN ACROSS THE NORTHERN AND EASTERN COUNTIES FOR THIS AFTERNOON WHERE FRONTAL FORCING WILL BE STRONGEST. HELICITY VALUES NEAR 200 M^2/S^2 SUGGESTS WEAK TORNADOES WILL STILL BE POSSIBLE...THOUGH DAMAGING WIND GUSTS IS STILL THE PRIMARY SEVERE THREAT. HAVE ADJUSTED THE HWO ACCORDINGLY. THIRD...MADE SOME ADJUSTMENTS TO AFTERNOON CLOUD COVER AS MORE BREAKS IN THE LOW LEVEL MOISTURE IS ANTICIPATED...AIDING THE SOUTH TO SOUTHWEST WINDS TO REACH THE WIND ADVISORY CRITERIA EAST OF THE MS RIVER. JAB PREV DISCUSSION... /ISSUED 523 AM CST SUN NOV 17 2013/ DISCUSSION... /ISSUED 458 AM CST SUN NOV 17 2013/ EARLY MORNING GOES WATER IMAGERY SHOWED A DEEP UPPER LEVEL TROF OVER THE CENTRAL AND NORTHERN PLAINS. THIS FEATURE WAS LIFTING EAST AND BECOMING NEGATIVELY TILTED. A 160KT 200MB JET EXTENDED FROM NORTH TX ACROSS THE OZARK PLATEAU...WITH INCREASINGLY DIFFLUENT FLOW EVIDENT DOWNSTREAM OF THE JET CORE. CLOSER TO HOME... THUNDERSTORMS HAD FORMED ON THE SOUTHERN FLANK OF THE JET CORE OVER NORTHERN AR...INTO WEST TN. THIS CONVECTION WAS ROOTED IN AN ELEVATED LAYER...THUS FAR UNABLE TO TAP INTO THE GREATER HELICITY EMBEDDED IN A WEAK NOCTURNAL INVERSION BELOW 925MB. EXPECT THE SHOWERS AND THUNDERSTORMS TO SHIFT EASTWARD THROUGH THE DAY PERHAPS LEAVING AREAS WEST OF THE RIVER FREE OF RAIN LATER THIS MORNING. LATE MORNING AND EARLY AFTERNOON SEVERE CHANCES WILL LIKELY DEPEND ON STORMS BECOMING ROOTED IN THE BOUNDARY LAYER... TAPPING BETTER DIRECTIONAL SHEAR FOR MORE PERSISTENT AND ORGANIZED STORM STRUCTURES. NAM BUFR SOUNDINGS SUGGESTS THIS IS A DISTINCT POSSIBILITY...PARTICULARLY IN THE 18Z TO 21Z TIME FRAME. STORMS WILL HAVE BETTER CHANCES OF BECOMING SURFACED BASED WITH THE ARRIVAL OF A SURFACE COLD FRONT INTO EASTERN AR AROUND 21Z/3PM. STORMS MAY REFORM AS FAR WEST AS JONESBORO...FORMING A LINE THAT WILL PROGRESS SOUTHEAST INTO THE NORTHEAST MS TOWARD 03Z/9 PM. MAIN SEVERE WEATHER THREAT ACROSS THE MIDSOUTH WILL DAMAGING STRAIGHT LINE WINDS. 06Z NAM PROGGED 700MB WEST/SOUTHWEST WINDS OF 60 TO 75 KTS NORTH OF I40 THIS AFTERNOON...PERHAPS LEADING TO SOME BOWING LINE SEGMENTS. THERE WILL BE SUFFICIENT HELICITY AND CAPE FOR SECONDARY TORNADO THREAT DURING THE MID TO LATE AFTERNOON. THE NAM PROGGED 03Z/9PM SURFACE CAPE NEAR 1000 J/KG AND 3KM HELICITY NEAR 300 M2/S2 AT TUPELO. STORMS ALONG THE ADVANCING COLD FRONT WILL HAVE A SHOT AT BECOMING ROOTED IN THE BOUNDARY LAYER. OTHERWISE...HIGHER CINH AND LOWER ELEVATED CAPE SHOULD PREVAIL OVER NORTH MS AS THE NOCTURNAL INVERSION FORMS. TRANQUIL WEATHER WILL PREVAIL MONDAY THROUGH WEDNESDAY...COURTESY OF PACIFIC SURFACE HIGH PRESSURE AND ZONAL FLOW ALOFT. GFS AND ECMWF HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO THE SPLIT UPPER LEVEL FLOW PATTERN LATE IN THE WEEK. BY THURSDAY...MIDLEVEL PACIFIC SUBTROPICAL MOISTURE WILL ACCOMPANY MODEST LOW LEVEL WARM ADVECTION TO SUPPORT A RETURN OF SCATTERED SHOWERS TO THE MIDSOUTH. BY LATE FRIDAY... COLLAPSING HEIGHTS OVER THE GREAT LAKES AND UPPER MIDWEST WILL DRIVE A SURFACE COLD FRONT THE MIDSOUTH LATE FRIDAY. COOLER AND MUCH DRIER MODIFIED ARCTIC AIR WILL SPREAD IN SATURDAY... WITH MIDLEVEL CLOUDS AND MOISTURE LIKEWISE PUSHING OFF TO THE SOUTH...INTO THE NORTHERN GULF OF MEXICO. NEXT WEEKEND/S WEATHER SHOULD BE MORE TYPICAL OF LATE NOVEMBER. PWB && .AVIATION... 12Z TAF SET IFR CIGS STILL HAVE YET TO MATERIALIZE EXCEPT AT KTUP. AREA OF SHRAS WITH EMBEDDED TSRAS CONTINUES TO DEVELOP AND PUSH EAST ACROSS THE CWA. CAN/T RULE OUT CIGS LOWERING TO IFR UNDERNEATH THE HEAVIER SHRAS/TSRAS...OTHERWISE EXPECT MVFR CONDITIONS TO PREVAIL THROUGH MUCH OF THE DAY AGAIN WITH THE POSSIBLE EXCEPTION OF KTUP. WOULD NOT BE SURPRISED TO SEE CONDITIONS RETURN TO VFR AT LOCATIONS SUCH AS KMEM AND KJBR THIS AFTERNOON. REDEVELOPMENT OF TSRAS IS EXPECTED ALONG THE FRONT THIS AFTERNOON INTO THIS EVENING. BEST CHANCES WILL OCCUR AT KMKL AND KTUP BETWEEN 23Z-05Z. SKIES WILL QUICKLY CLEAR BEHIND THE FRONT. STRONG S TO SW WINDS EXPECTED TODAY WITH SUSTAIN SPEEDS OF 10-17 KTS WITH GUSTS BETWEEN 15-28 KTS. WINDS WILL TURN AROUND TO THE NW AND EVENTUALLY N BEHIND THE FRONT. SPEEDS WILL DIMINISH TO BETWEEN 5-10 KTS AS WELL DURING THE OVERNIGHT HOURS. KRM && .PRELIMINARY POINT TEMPS/POPS... MEM 78 46 62 40 / 100 20 0 0 MKL 76 41 61 34 / 100 30 0 0 JBR 79 42 60 35 / 60 10 0 0 TUP 76 46 65 37 / 100 40 0 0 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR DUNKLIN-PEMISCOT. MS...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ALCORN-BENTON MS- CALHOUN-COAHOMA-DESOTO-LAFAYETTE-MARSHALL-PANOLA-PONTOTOC- QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TUNICA-UNION-YALOBUSHA. TN...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
944 AM CST SUN NOV 17 2013 .UPDATE... UPDATED TO REDUCE MORNING AND AFTERNOON RAIN CHANCES AND TO ADJUST SEVERE WEATHER WORDING. && .DISCUSSION... FIRST...CONVECTION WITH THE LOW LEVEL INSTABILITY AXIS MOVING FASTER EAST THAN PREVIOUSLY FORECASTED...SO HAVE ADJUSTED RAIN CHANCES ACCORDINGLY FOR THE REMAINDER OF THE MORNING. SECOND...AFTER ANALYSIS OF THE HRRR MODEL...CURRENT SIGNIFICANT MIXING IN THE OBSERVATIONS AHEAD OF THE FRONT IN NORTHWEST ARKANSAS...AND STRONG CAP DEVELOPING AHEAD OF THE FRONT OFF OF 12Z SGF SOUNDING...IT APPEARS THAT THE SEVERE THREAT WILL REMAIN ACROSS THE NORTHERN AND EASTERN COUNTIES FOR THIS AFTERNOON WHERE FRONTAL FORCING WILL BE STRONGEST. HELICITY VALUES NEAR 200 M^2/S^2 SUGGESTS WEAK TORNADOES WILL STILL BE POSSIBLE...THOUGH DAMAGING WIND GUSTS IS STILL THE PRIMARY SEVERE THREAT. HAVE ADJUSTED THE HWO ACCORDINGLY. THIRD...MADE SOME ADJUSTMENTS TO AFTERNOON CLOUD COVER AS MORE BREAKS IN THE LOW LEVEL MOISTURE IS ANTICIPATED...AIDING THE SOUTH TO SOUTHWEST WINDS TO REACH THE WIND ADVISORY CRITERIA EAST OF THE MS RIVER. JAB && .PREV DISCUSSION... /ISSUED 523 AM CST SUN NOV 17 2013/ DISCUSSION... /ISSUED 458 AM CST SUN NOV 17 2013/ EARLY MORNING GOES WATER IMAGERY SHOWED A DEEP UPPER LEVEL TROF OVER THE CENTRAL AND NORTHERN PLAINS. THIS FEATURE WAS LIFTING EAST AND BECOMING NEGATIVELY TILTED. A 160KT 200MB JET EXTENDED FROM NORTH TX ACROSS THE OZARK PLATEAU...WITH INCREASINGLY DIFFLUENT FLOW EVIDENT DOWNSTREAM OF THE JET CORE. CLOSER TO HOME... THUNDERSTORMS HAD FORMED ON THE SOUTHERN FLANK OF THE JET CORE OVER NORTHERN AR...INTO WEST TN. THIS CONVECTION WAS ROOTED IN AN ELEVATED LAYER...THUS FAR UNABLE TO TAP INTO THE GREATER HELICITY EMBEDDED IN A WEAK NOCTURNAL INVERSION BELOW 925MB. EXPECT THE SHOWERS AND THUNDERSTORMS TO SHIFT EASTWARD THROUGH THE DAY PERHAPS LEAVING AREAS WEST OF THE RIVER FREE OF RAIN LATER THIS MORNING. LATE MORNING AND EARLY AFTERNOON SEVERE CHANCES WILL LIKELY DEPEND ON STORMS BECOMING ROOTED IN THE BOUNDARY LAYER... TAPPING BETTER DIRECTIONAL SHEAR FOR MORE PERSISTENT AND ORGANIZED STORM STRUCTURES. NAM BUFR SOUNDINGS SUGGESTS THIS IS A DISTINCT POSSIBILITY...PARTICULARLY IN THE 18Z TO 21Z TIME FRAME. STORMS WILL HAVE BETTER CHANCES OF BECOMING SURFACED BASED WITH THE ARRIVAL OF A SURFACE COLD FRONT INTO EASTERN AR AROUND 21Z/3PM. STORMS MAY REFORM AS FAR WEST AS JONESBORO...FORMING A LINE THAT WILL PROGRESS SOUTHEAST INTO THE NORTHEAST MS TOWARD 03Z/9 PM. MAIN SEVERE WEATHER THREAT ACROSS THE MIDSOUTH WILL DAMAGING STRAIGHT LINE WINDS. 06Z NAM PROGGED 700MB WEST/SOUTHWEST WINDS OF 60 TO 75 KTS NORTH OF I40 THIS AFTERNOON...PERHAPS LEADING TO SOME BOWING LINE SEGMENTS. THERE WILL BE SUFFICIENT HELICITY AND CAPE FOR SECONDARY TORNADO THREAT DURING THE MID TO LATE AFTERNOON. THE NAM PROGGED 03Z/9PM SURFACE CAPE NEAR 1000 J/KG AND 3KM HELICITY NEAR 300 M2/S2 AT TUPELO. STORMS ALONG THE ADVANCING COLD FRONT WILL HAVE A SHOT AT BECOMING ROOTED IN THE BOUNDARY LAYER. OTHERWISE...HIGHER CINH AND LOWER ELEVATED CAPE SHOULD PREVAIL OVER NORTH MS AS THE NOCTURNAL INVERSION FORMS. TRANQUIL WEATHER WILL PREVAIL MONDAY THROUGH WEDNESDAY...COURTESY OF PACIFIC SURFACE HIGH PRESSURE AND ZONAL FLOW ALOFT. GFS AND ECMWF HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO THE SPLIT UPPER LEVEL FLOW PATTERN LATE IN THE WEEK. BY THURSDAY...MIDLEVEL PACIFIC SUBTROPICAL MOISTURE WILL ACCOMPANY MODEST LOW LEVEL WARM ADVECTION TO SUPPORT A RETURN OF SCATTERED SHOWERS TO THE MIDSOUTH. BY LATE FRIDAY... COLLAPSING HEIGHTS OVER THE GREAT LAKES AND UPPER MIDWEST WILL DRIVE A SURFACE COLD FRONT THE MIDSOUTH LATE FRIDAY. COOLER AND MUCH DRIER MODIFIED ARCTIC AIR WILL SPREAD IN SATURDAY... WITH MIDLEVEL CLOUDS AND MOISTURE LIKEWISE PUSHING OFF TO THE SOUTH...INTO THE NORTHERN GULF OF MEXICO. NEXT WEEKEND/S WEATHER SHOULD BE MORE TYPICAL OF LATE NOVEMBER. PWB && .AVIATION... 12Z TAF SET IFR CIGS STILL HAVE YET TO MATERIALIZE EXCEPT AT KTUP. AREA OF SHRAS WITH EMBEDDED TSRAS CONTINUES TO DEVELOP AND PUSH EAST ACROSS THE CWA. CAN/T RULE OUT CIGS LOWERING TO IFR UNDERNEATH THE HEAVIER SHRAS/TSRAS...OTHERWISE EXPECT MVFR CONDITIONS TO PREVAIL THROUGH MUCH OF THE DAY AGAIN WITH THE POSSIBLE EXCEPTION OF KTUP. WOULD NOT BE SURPRISED TO SEE CONDITIONS RETURN TO VFR AT LOCATIONS SUCH AS KMEM AND KJBR THIS AFTERNOON. REDEVELOPMENT OF TSRAS IS EXPECTED ALONG THE FRONT THIS AFTERNOON INTO THIS EVENING. BEST CHANCES WILL OCCUR AT KMKL AND KTUP BETWEEN 23Z-05Z. SKIES WILL QUICKLY CLEAR BEHIND THE FRONT. STRONG S TO SW WINDS EXPECTED TODAY WITH SUSTAIN SPEEDS OF 10-17 KTS WITH GUSTS BETWEEN 15-28 KTS. WINDS WILL TURN AROUND TO THE NW AND EVENTUALLY N BEHIND THE FRONT. SPEEDS WILL DIMINISH TO BETWEEN 5-10 KTS AS WELL DURING THE OVERNIGHT HOURS. KRM && .PRELIMINARY POINT TEMPS/POPS... MEM 78 46 62 40 / 100 20 0 0 MKL 76 41 61 34 / 100 30 0 0 JBR 79 42 60 35 / 60 10 0 0 TUP 76 46 65 37 / 100 40 0 0 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR DUNKLIN-PEMISCOT. MS...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ALCORN-BENTON MS- CALHOUN-COAHOMA-DESOTO-LAFAYETTE-MARSHALL-PANOLA-PONTOTOC- QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TUNICA-UNION-YALOBUSHA. TN...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
357 PM EST SUN NOV 17 2013 .SYNOPSIS... LOW PRESSURE WAS OVER THE GREAT LAKES WITH A STRONG COLD FRONT EXTENDING FROM THE LOW INTO THE SOUTHERN PLAINS. THIS FRONT WILL RACE EAST TONIGHT AND WILL BE OFF THE COAST BY MONDAY AFTERNOON. COLD HIGH PRESSURE SETTLES OVER THE GREAT LAKES TUESDAY AND WEDNESDAY BRINGING DRIER WEATHER INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH MONDAY/... AS OF 345 PM EST SUNDAY... RAPIDLY CHANGING WEATHER TONIGHT AND MONDAY. AREA OF LIGHT TO MODERATE SHOWERS WAS MOVING INTO THE WESTERN COUNTY WARNING AREA AS OF 300PM. LOCAL WRF...HRRR AND RAP MODELS HAVE THESE SHOWERS MOVING EAST ACROSS THE FORECAST AREA BY MIDNIGHT. INTENSE COLD FRONT EXTENDED FROM NORTHERN ILLINOIS INTO CENTRAL ARKANSAS. THIS FRONT WILL MOVE QUICKLY EAST AND WILL REACH THE WESTERN COUNTIES OF THE FORECAST AREA AROUND 11PM. AHEAD OF THE FRONT THE LOW LEVEL JET INCREASES...WITH 850 MB WINDS IN THE 50 TO 60 KNOT RANGE. HAVE EXPANDED THE WIND ADVISORY INTO TAZEWELL COUNTY FOR TONIGHT. STILL A THREAT OF STRONG TO DAMAGING WINDS AFTER MIDNIGHT WITH THE BAND OF SHOWERS AND POSSIBLY ISOLATED THUNDERSTORMS ALONG THE FRONT. THE FRONT IS EXPECTED TO EXIT THE EASTERN COUNTY WARNING AREA BETWEEN 4AM AND 7AM. NOT MUCH DROP IN TEMPERATURES UNTIL THE FRONT GOES THROUGH THEN ON MONDAY NOT MUCH RECOVERY OF TEMPERATURES WITH MODERATE COLD AIR ADVECTION. STRONG ENOUGH PRESSURE RISES...IN THE +5 TO +10 MB/6HR RANGE TO ENHANCE THE WINDS FOR MUCH OF THE DAY. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... AS OF 311 PM EST SUNDAY... STILL A GRADIENT LEFT MONDAY NIGHT ALTHOUGH SURFACE HIGH PRESSURE IS ON APPROACH. LEFTOVER WINDS COMBINED WITH SOME CLOUDS ACROSS SE WEST VA WILL KEEP TEMPS A LITTLE WARMER THAN THEY WOULD BE IF THE CENTER OF THE SURFACE HIGH WAS PARKED OVERHEAD. INTO TUESDAY AFTERNOON...HIGH PRESSURE BEGINS A TRIP TOWARDS PENNSYLVANIA AND NEW ENGLAND...EVENTUALLY IN THE QUINTESSENTIAL WEDGE POSITION FOR WEDNESDAY. WITH DOWNSLOPING FLOW REMOVED...COLDER H85 VALUES AROUND 0C WILL COVER MOST OF THE CWA UNDER CLEAR SKIES TUESDAY. DEWPOINTS MAY FALL INTO THE LOWER 20S AND UPPER TEENS SETTING THE STAGE FOR A VERY COLD TUESDAY NIGHT...IF MID AND HIGH CLOUDS HOLD OFF FROM THE SOUTH...AND DEVELOPING EASTERLY FLOW REMAINS WEAK. INCREASING MID/HIGH CLOUDS WEDNESDAY...A VERY COLD START AND SUBTLE EASTERLY BREEZES WITHIN THE WEDGE MAY KEEP MOST LOCATIONS BELOW 50F FOR WEDNESDAY...WHICH IS BELOW THE MEX/ECMWF MOS NUMBERS. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 340 PM EST SUNDAY... A FEW CHANGES IN THE EXTENDED FORECAST BUT STILL LOOKS WET FRIDAY NIGHT INTO SATURDAY EVENING. MODELS ARE ARGUING WHICH WEATHER FEATURE WILL BRING RAIN TO THE AREA. THE 12Z GFS FAVORS A SHORT COMING ACROSS THE TENN VALLEY AND OVER THE WEDGE THURSDAY NIGHT. FRIDAY AND FRIDAY NIGHT...THE GFS HAS WAVES RIDING ALONG THE FRONT..EVENTUALLY PUSHING THE COLD FRONT TO THE EAST COAST SATURDAY MORNING. THE 12Z ECMWF HAS A COLD FRONT MOVING SLOWLY TO THE EAST...FROM MISSISSIPPI VALLEY THURSDAY NIGHT...INTO THE OHIO VALLEY FRIDAY AFTERNOON...THEN STALLS IT OVER THE MID ATLANTIC-SOUTHERN APPALACHIAN MOUNTAINS SATURDAY MORNING. A SURFACE WAVE THEN DEVELOPS ALONG THE FRONT...POSSIBLY OVER THE FORECAST AREA SATURDAY. THIS WAVE WILL THEN TRACK NORTHEAST...PULLING THE FRONT ACROSS THE REGION BY SATURDAY EVENING. SINCE THERE IS DISCONTINUITY BETWEEN MODELS AND RUN-TO-RUN WITH EACH MODEL...WILL KEEP POPS IN A 20-40 PERCENT RANGE FRIDAY AFTERNOON INTO SATURDAY AFTERNOON. WITH EITHER MODEL AND/OR SCENARIO...THE GULF IS OPEN TO BRING THE AREA MUCH NEEDED RAIN FRIDAY INTO SATURDAY. ALSO...MILD TO WARM TEMPERATURES LIKELY FRIDAY...DEPENDING ON IF A LOCATION SEES RAIN. ONCE THE FRONT MOVES TO THE COAST...85H TEMPERATURES DROP TO -10C. && .AVIATION /21Z SUNDAY THROUGH FRIDAY/... AS OF 1250 AM EST SUNDAY... SIGNIFICANT CHANGES WILL BE OCCURRING DURING THE TAF PERIOD. LIFR TO IFR STRATUS AND FOG EAST OF THE BLUE RIDGE WILL GRADUALLY LIFT AS A SURFACE WEDGE ERODES AND WINDS BECOME SOUTH TO SOUTHWEST. THE VISIBILITY AT KROA AND KDAN HAD ALREADY BECOME VFR. KLYH MAY TAKE UNTIL 20/3PM TO IMPROVE. A BAND OF SHOWERS FROM WEST VIRGINIA INTO CENTRAL TENNESSEE WILL MOVE ACROSS THE REGION BETWEEN 21Z/4PM AND 06Z/1AM. EXPECT THIS PRECIPITATION TO REACH KLWB AROUND 21Z/4PM WITH OCCASIONAL MVFR VISIBILITIES AND VFR CEILINGS JUST ABOVE 3000 FEET. THESE SHOWERS ARE NOT EXPECTED TO REACH KLYH AND KDAN UNTIL AFTER 00Z/7PM. A STRONG COLD FRONT WILL BE CROSSING THE AREA BETWEEN 00Z AND 12Z. MODELS WERE ALL SIMILAR WITH THE TIMING OF THE FRONT. LINE OF SHOWERS ALONG THE BOUNDARY MAY PRODUCE WIND GUSTS AT KLWB AND KBLF OF 40 TO 50 KNOTS BUT CONFIDENCE IS LOW THAT OTHER TAF SITES WILL HAVE THE POTENTIAL FOR WINDS THAT STRONG SINCE LINE IS EXPECTED TO WEAKEN AS IT MOVES EAST. COLD AIR ADVECTION AND TIGHT PRESSURE GRADIENTS WILL RESULT IN GUSTY WINDS BY MONDAY AFTERNOON. EXPECT WIND GUSTS OF 25 TO 35 KNOTS. THE SKY WILL CLEAR MONDAY MORNING AS A MUCH DRIER AIR MASS ADVECTS INTO THE REGION. DRY HIGH PRESSURE WILL SUPPORT VFR CONDITIONS THROUGH TUESDAY AFTERNOON...BEFORE WEDGING AGAINST THE EASTERN FACE OF THE APPALACHIANS. MAY SEE A RETURN OF STRATUS THURSDAY MORNING AS THE NORTHEAST FLOW WORKS ATLANTIC MOISTURE TOWARD THE BLUE RIDGE. && .FIRE WEATHER... AS OF 450 AM EST SUNDAY... REGION STAYS IN MOIST AIR MASS TONIGHT IN ADVANCE OF A STRONG COLD FRONT. THE PROBABILITY OF A WETTING RAIN RISES SHARPLY BY THIS EVENING. WINDS FROM THE SOUTH AND SOUTHWEST INCREASE LATER OVERNIGHT....ESPECIALLY AT HIGHER ELEVATIONS AHEAD OF THE FRONT. ONCE THE FRONT COMES THROUGH EARLY MONDAY MORNING...WIND WILL SHIFT TO THE WEST AND NORTHWEST. GUSTY WINDS ARE EXPECTED MONDAY AND MONDAY NIGHT. BY THE TIME RELATIVE HUMIDITIES DROP BACK DOWN TO AROUND 30 PERCENT ON TUESDAY...WIND SPEEDS WILL BE DIMINISHING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR VAZ007-019-020-024-035. NC...NONE. WV...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR WVZ042-043-045. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KM LONG TERM...RCS AVIATION...AMS/NF FIRE WEATHER...AMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
408 AM EST TUE NOV 19 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST TODAY WHILE A TROUGH LINGERS OVER QUEBEC. WE HAD LITTLE IN THE WAY OF LAKE EFFECT SNOW OVERNIGHT WITH RIDGING OVER ALL BUT ABOUT THE EASTERN THIRD OF LAKE ERIE. SOME LIGHT SNOW SHOWERS THAT WERE FOCUSED TOWARDS NEW YORK MAY SHIFT WESTWARD INTO MAINLY NW PA AS WINDS THROUGH 850MB BECOME MORE NORTHERLY THIS MORNING. AFTER THAT TIME THE MOISTURE DEPTH DECREASES WITH STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME TO AN END. NO ACCUMULATION EXPECTED. MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE REGION WITH SKIES CLEARING BY LATE MORNING. INVERSION HEIGHTS LOWER TODAY AS THE HIGH BUILDS OVERHEAD AND THE RUC SEEMS TO BE DOING THE BEST WITH WITH HIGH 925MB MOISTURE THROUGH THE DAY. WILL FAVOR A MORE PESSIMISTIC CLOUD FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT THIS EVENING. HIGHS WILL ONLY RECOVER A FEW DEGREES WITH COOL NORTHERLY FLOW WITH HIGHS IN THE UPPER 30S/LOW 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S. UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE SLOWER AND LESS ROBUST WITH PRECIPITATION. PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL. && .LONG TERM /SATURDAY THROUGH MONDAY/... WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY 12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN. SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD WARMER ON MONDAY. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... DEEP LOW PRESSURE IN WESTERN QUEBEC WILL CONTINUE NORTHEAST OVERNIGHT AS HIGH PRESSURE BUILDS IN FROM THE WEST. LOW LEVEL WRAP AROUND MOISTURE IS CURRENTLY ACROSS NRN OHIO AND NWRN PA TRAPPED UNDER AN INVERSION. MOST CIGS VFR HOWEVER THERE ARE PATCHES OF MVFR MIXED IN. DO EXPECT PERIODS OF MVFR TO CONTINUE ESPECIALLY KERI WHERE COLD ADVECTION WILL INCREASINGLY TAP LAKE MOISTURE. ALSO A DECENT CHANCE OF AN MVFR CIG AT KMFD IN UPSLOPE FLOW AND ALSO KTOL...ADVECTING IN FROM SRN LWR MI. OTHERWISE EXPECT A LOW VFR CIGS TO CONTINUE ACROSS THE REGION THROUGH THE NIGHT. DID KEEP MVFR CONDITIONS AT KERI MOST OF THE NIGHT WITH A FEW LIGHT RAIN AND SNOW SHOWERS POSSIBLE WITH THE INCREASING LAKE INFLUENCE. TREND TO VFR FOR THE AREA TUESDAY WITH BUILDING HIGH PRESSURE HOWEVER THERE IS A POTENTIAL THAT THE STRATUS WILL HANG ON INTO/THRU THE MORNING HOURS...REMAINING TRAPPED UNDER THE INVERSION. OUTLOOK...NON VFR POSSIBLE THURSDAY. && .MARINE... STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME NORTHWEST ON SATURDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148- 149. SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR LEZ144>147. && $$ SYNOPSIS...KEC NEAR TERM...KEC SHORT TERM...KEC LONG TERM...KUBINA AVIATION...TK MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
348 AM CST TUE NOV 19 2013 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 348 AM CST TUE NOV 19 2013 AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS. THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE. FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO 50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A TENTH OF AND INCH. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 348 AM CST TUE NOV 19 2013 ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY DECLINE DURING THE EVENING. ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS... ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT. HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE. ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS WILL BE LESS THAN A HALF INCH. ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECWMF IS A BIT LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S. SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE ALL BLEND MAXIMUM TEMPERATURES. SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN COLDER. LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED WITH THE ALL BLEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1125 PM CST MON NOV 18 2013 THE MAIN CONCERN WILL BE INCREASING WINDS TUE AND LLWS TUE EVENING. THE SFC HIGH PRESSURE RIDGE AXIS WAS OVER THE AREA LATE THIS EVENING. WINDS WILL BE LIGHT THRU MUCH OF THE OVERNIGHT HOURS AS THE SFC HIGH DRIFTS ACROSS THE AREA. BY 12Z THE RIDGE AXIS WILL HAVE MOVED INTO EASTERN WI...WITH WINDS BECOMING SOUTH TO SOUTHEAST AND INCREASING LATE TONIGHT AND THRU TUE MORNING. BY TUE AFTERNOON THE HIGH WILL BE IN OH. A TIGHT PRESSURE GRADIENT WILL ONCE AGAIN BE OVER THE UPPER MIDWEST BY TUE AFTERNOON AND FOR TUE NIGHT. BY TUE AFTERNOON SOUTHEAST-SOUTH WINDS WILL INCREASE INTO THE 10-20KT G20- 30KT RANGE. THESE WINDS WILL CONTINUE TUE NIGHT...BUT AS THE NIGHT- TIME INVERSION DEVELOPS...WINDS 1500-2000FT AGL ARE GOING TO INCREASE INTO THE 50KT RANGE FROM THE SOUTH-SOUTHWEST. INCLUDED LLWS AT KLSE AFTER 00Z WED. THE AIRMASS WITH THE HIGH AND ON THE BACK SIDE OF THE HIGH IS DRY. SKC EXPECTED TONIGHT...MAINLY SCT-BKN HIGH CLOUDS TUE THEN SCT 8K- 10K FT CLOUDS TUE NIGHT...WITH VFR VSBYS THRU THE PERIOD. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
358 AM PST Tue Nov 19 2013 .Synopsis... A moist system from the Pacific Ocean will continue widespread precipitation across interior northern California through the middle of the week. && .Discussion... Strong zonal flow continues over the EPAC with 120-130 kt upper jet aligned along and south of 40N. Initial frontal band and moisture plume (TPW of 1 to 1.25 inches) has moved inland across NORCAL overnight, but its progress southward is stalling. Much of the northern half of the Sacramento Valley has received 1 to 2 tenths of an inch of rain since Monday evening while the mountains to the north of Redding have seen around 1/4 to 1/2 inch. Areas further to the south including the Sacramento area have seen much lighter rainfall amounts with only a trace to a few hundredths of an inch reported so far. Snow levels will start out around 6000 to 6500 feet early this morning, but are expected to rise over 7000 to 7500 feet later today as warm advection increases and drier air is mixed out. The higher elevation northern Sierra passes may see an inch or so of slushy accumulation today. Appears and front and moisture plume will stall out over the area today, and with weak forcing only light amounts of QPF are expected. Hi-res HRRR indicates a brief break early this morning over the southern Sacramento Valley with more light precip spreading into the region around 16Z. Some enhancement of precip is expected by late this afternoon into Wednesday as the next short-wave approaches leading to a little stronger lift across the region. Front forecast to shift south of the region Wednesday as a stronger short-wave moves through. Precip expected to turn more showery across the region, and appears there may be a chance for thunderstorms across the southern half of the forecast area as the short-wave moves through during the middle of the day. Snow levels expected to remain high (generally at or above 7000 feet through Wednesday), so significant snow accumulation will be limited to the crest of the northern Sierra. 60 hour snow accumulations from today into early Thursday may approach 10 inches around the 8000 ft level and above. Showers are expected to end over much of the interior of NORCAL by early Thursday as the trough digs southward and closes off vicinity of SOCAL. There may be some lingering showers through the day along the northern Sierra crest south of Lake Tahoe due to cyclonic (or backwash) flow of the upper low. By the end of the day on THU...anticyclonic flow aloft over the nrn portion of the CWA should begin to clear/erode cloud cover. With moist ground and ridging developing late in the week...we would be thinking about valley stratus/fog. However...at this time strong enough pressure gradients should result in a katabatic wind precluding fog/stratus formation most areas. && .Extended Discussion (Saturday through Tuesday)... Areas breezy to windy northeast to east winds continue over interior NorCal Saturday as positively tilted upper ridge builds inland. Pressure gradient weakens Sunday with lighter wind. Upper ridge persists over Northern Cal through the weekend into early next week bringing dry weather with slightly above normal temperatures. && .Aviation... Wdsprd MVFR/IFR conds tda into Wed in pcpn with lcl LIFR omtns. Snow lvls genly aoa 060. Isold tstms poss ovr srn hlf of fcst area Wed aftn. W flow alf with Sly wnds up to 20 kts nr sfc tda into tngt with Lcl SW sfc wnd gsts up to 35 kts ovr hyr mtn trrn. && .STO Watches/Warnings/Advisories...None. && $$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
945 AM EST TUE NOV 19 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A CLEARING TREND CAN BE SEEN UPSTREAM ACROSS MICHIGAN AND HAVE TRIED TO TIME THIS INTO OHIO THROUGH MID-DAY. CLOUDS MAY EXPERIENCE SOME DIURNAL ENHANCEMENT TOWARDS LATE MORNING...WITH THE DECREASING TREND RESUMING DURING THE AFTERNOON. NO SIGNIFICANT DEVIATION FROM THIS WITH THE MID MORNING UPDATE. PREVIOUS DISCUUSION...HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST TODAY WHILE A TROUGH LINGERS OVER QUEBEC. WE HAD LITTLE IN THE WAY OF LAKE EFFECT SNOW OVERNIGHT WITH RIDGING OVER ALL BUT ABOUT THE EASTERN THIRD OF LAKE ERIE. SOME LIGHT SNOW SHOWERS THAT WERE FOCUSED TOWARDS NEW YORK MAY SHIFT WESTWARD INTO MAINLY NW PA AS WINDS THROUGH 850MB BECOME MORE NORTHERLY THIS MORNING. AFTER THAT TIME THE MOISTURE DEPTH DECREASES WITH STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME TO AN END. NO ACCUMULATION EXPECTED. MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE REGION. INVERSION HEIGHTS LOWER TODAY AS THE HIGH BUILDS OVERHEAD AND THE RUC SEEMS TO BE DOING THE BEST WITH WITH HIGH 925MB MOISTURE THROUGH THE DAY. WILL FAVOR A MORE PESSIMISTIC CLOUD FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT THIS EVENING. HIGHS WILL ONLY RECOVER A FEW DEGREES WITH COOL NORTHERLY FLOW WITH HIGHS IN THE UPPER 30S/LOW 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S. UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE SLOWER AND LESS ROBUST WITH PRECIPITATION. PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL. && .LONG TERM /SATURDAY THROUGH MONDAY/... WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY 12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN. SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD WARMER ON MONDAY. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... STRATO CU CIGS CONTINUE TO BLANKET THE AREA THIS MORNING. STARTING TO SEE THE CLOUDS BREAK UP OVER LOWER MICHIGAN AND EXPECT CLEARING TO BEGIN ACROS THE AREA LATER THIS MORNING. IT WILL LIKELY TAKE TILL LATE IN THE DAY BEFORE KERI AND KYNG LOSE THEIR CIGS. FOR THE MOST PART CIGS SHOULD BE VFR THIS MORNING BUT A COUPLE OF POCKETS OF MVFR REMAIN. THESE SHOULD LIFT SHORTLY. NW FLOW WILL BECOME N THIS AFTERNOON AND THEN LIGHT AND VARIABLE OVERNIGHT. THE SECOND HALF OF THE TAF PERIOD SHOULD BE MAINLY CLEAR. OUTLOOK...NON VFR POSSIBLE THURSDAY. && .MARINE... STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME NORTHWEST ON SATURDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148- 149. && $$ SYNOPSIS...KEC NEAR TERM...KEC/OUDEMAN SHORT TERM...KEC LONG TERM...KUBINA AVIATION...KUBINA MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
652 AM EST TUE NOV 19 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A CLEARING TREND CAN BE SEEN UPSTREAM ACROSS MICHIGAN AND HAVE TRIED TO TIME THIS INTO OHIO THROUGH MID-DAY. CLOUDS MAY EXPERIENCE SOME DIURNAL ENHANCEMENT TOWARDS LATE MORNING...WITH THE DECREASING TREND RESUMING DURING THE AFTERNOON. PREVIOUS DISCUUSION...HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST TODAY WHILE A TROUGH LINGERS OVER QUEBEC. WE HAD LITTLE IN THE WAY OF LAKE EFFECT SNOW OVERNIGHT WITH RIDGING OVER ALL BUT ABOUT THE EASTERN THIRD OF LAKE ERIE. SOME LIGHT SNOW SHOWERS THAT WERE FOCUSED TOWARDS NEW YORK MAY SHIFT WESTWARD INTO MAINLY NW PA AS WINDS THROUGH 850MB BECOME MORE NORTHERLY THIS MORNING. AFTER THAT TIME THE MOISTURE DEPTH DECREASES WITH STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME TO AN END. NO ACCUMULATION EXPECTED. MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE REGION. INVERSION HEIGHTS LOWER TODAY AS THE HIGH BUILDS OVERHEAD AND THE RUC SEEMS TO BE DOING THE BEST WITH WITH HIGH 925MB MOISTURE THROUGH THE DAY. WILL FAVOR A MORE PESSIMISTIC CLOUD FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT THIS EVENING. HIGHS WILL ONLY RECOVER A FEW DEGREES WITH COOL NORTHERLY FLOW WITH HIGHS IN THE UPPER 30S/LOW 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S. UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE SLOWER AND LESS ROBUST WITH PRECIPITATION. PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL. && .LONG TERM /SATURDAY THROUGH MONDAY/... WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY 12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN. SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD WARMER ON MONDAY. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... STRATO CU CIGS CONTINUE TO BLANKET THE AREA THIS MORNING. STARTING TO SEE THE CLOUDS BREAK UP OVER LOWER MICHIGAN AND EXPECT CLEARING TO BEGIN ACROS THE AREA LATER THIS MORNING. IT WILL LIKELY TAKE TILL LATE IN THE DAY BEFORE KERI AND KYNG LOSE THEIR CIGS. FOR THE MOST PART CIGS SHOULD BE VFR THIS MORNING BUT A COUPLE OF POCKETS OF MVFR REMAIN. THESE SHOULD LIFT SHORTLY. NW FLOW WILL BECOME N THIS AFTERNOON AND THEN LIGHT AND VARIABLE OVERNIGHT. THE SECOND HALF OF THE TAF PERIOD SHOULD BE MAINLY CLEAR. OUTLOOK...NON VFR POSSIBLE THURSDAY. && .MARINE... STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME NORTHWEST ON SATURDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148- 149. SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR LEZ144>147. && $$ SYNOPSIS...KEC NEAR TERM...KEC SHORT TERM...KEC LONG TERM...KUBINA AVIATION...KUBINA MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
515 AM CST TUE NOV 19 2013 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 348 AM CST TUE NOV 19 2013 AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS. THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE. FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO 50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A TENTH OF AND INCH. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 348 AM CST TUE NOV 19 2013 ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY DECLINE DURING THE EVENING. ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS... ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT. HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE. ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS WILL BE LESS THAN A HALF INCH. ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECMWF IS A BIT LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S. SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE ALL BLEND MAXIMUM TEMPERATURES. SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN COLDER. LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED WITH THE ALL BLEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 515 AM CST TUE NOV 19 2013 PRESSURE GRADIENT WILL TIGHTEN TODAY ON THE BACKSIDE OF AN EASTWARD MOVING HIGH PRESSURE SYSTEM. WINDS WILL INCREASE QUICKLY - BY MID/LATE MORNING - FROM A SOUTHERLY DIRECTION. THERE WILL BE SOME GUSTINESS...BUT MINIMALIZED SOMEWHAT AS LOW LEVEL WINDS ARE NOT UNDIRECTIONAL AND MIXING IS INHIBITED SOMEWHAT. THE WINDS WILL STAY UP TONIGHT...WITH BUFKIT SOUNDINGS VIA THE RAP/NAM/GFS ALL POINTING TO A 50-60 KT 2 KFT JET DEVELOPING BY 03Z. LLWS A CONCERN AS A RESULT...AND WILL CONTINUE MENTION AT KLSE...AND ADD TO THE TAF FOR KRST. SOME HIGH THIN CLOUDS WILL SWEEP ACROSS THE REGION TODAY...WITH SOME MID 8-10 KFT CLOUDS TONIGHT. VFR CONDITIONS ARE ANTICIPATED INTO WEDNESDAY MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM....BOYNE AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
311 PM MST TUE NOV 19 2013 .SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT) ISSUED AT 310 PM MST TUE NOV 19 2013 MOIST LOW AMPLITUDE SHORT WAVE RACES ACROSS NORTHWEST COLORADO TONIGHT. RADAR SHOWING LOW DBZ RETURNS AS THE MOISTURE INCREASES THIS AFTERNOON...SOME OF THIS PCPN IS REACHING THE GROUND AS KCAG MEASURED A TRACE AND SUNLIGHT MOUNTAIN AWOS REPORTS LIGHT SNOW. THE COMBINATION OF OROGRAPHICS AND WEAK DYNAMICAL FORCING WILL RESULT IN WIDESPREAD LIGHT PCPN OVERNIGHT ACROSS NW COLORADO...POSSIBLY EXTENDING AS FAR SOUTH AS THE ELK MOUNTAINS. ENHANCED CLOUD COVER IN THE INFRARED IS SOMEWHAT FRAGMENTED AND UPSTREAM RADAR OBSERVATIONS SHOW BROKEN AREAS OF PCPN. THE RAP MODEL SHOW PCPN EXPANDING AS THE SHORT WAVE GETS LIFTED OVER THE DIVIDE...BUT APPEARS THAT THE TIME DURATION DOES NOT LAST LONG ENOUGH FOR ADVISORY CRITERIA SNOWFALL. APPEARS THE ELKHEADS AND PARK RANGE MAY GET A FEW INCHES OF SNOW TONIGHT...BUT TAPERING OFF AFTER MIDNIGHT. THE SRN HALF HALF GETS EXTENSIVE CLOUD COVER BUT THE MOISTURE IS NOT AS DEEP...FLURRIES OR BRIEF LIGHT SNOW MAY OCCUR OVER THE SAN JUAN MOUNTAINS AS THE SHORT WAVE DRAGS ACROSS WRN COLORADO. SATELLITE INFRARED AND WATER VAPOR CLEARLY SHOWS A STREAM OF MOISTURE FROM NW OF THE HAWAIIAN ISLES TO THE CALIFORNIA COAST. THE FORECAST AREA MAY GET ONLY ONE SHOT AT THIS MOISTURE AND THAT OCCURS FROM WEDNESDAY AFTERNOON INTO THURSDAY. BUT SHORT WAVE ENERGY ADVECTING THIS MOISTURE TO THE FOUR CORNERS REGION IS WEAK AND FRAGMENTED (SIMILAR TO THE LEAD SHORT WAVE). NO SHORTAGE OF MOISTURE AS 700 MB SPECIFIC HUMIDITY VALUES EXCEED 4 G/KG...BUT OTHER FEATURES THAT ARE NEEDED FOR EFFICIENT RAIN OR SNOW PRODUCTION ARE MISSING. LACKING ELEMENTS INCLUDE BAROCLINICITY AND DYNAMICAL/OROGRAPHICAL FORCING AS 700 MB GRADIENT FLOW IS LESS THAN 20 KNOTS. THE AREA OF PRECIPITATION WILL BE EXPANDING WEDNESDAY AFTERNOON OVER SW COLORADO AND SPREADING NEWD...CURRENT QPF PROJECTIONS SUGGEST SNOW POTENTIAL OF 4 TO 8 INCHES OVER THE SAN JUAN AND WRN COLORADO CENTRAL MOUNTAINS. THE DEEPEST MOISTURE WILL BE POSITIONED ACROSS THE REGION ON WEDNESDAY NIGHT BEFORE SHIFTING DOWNSTREAM BY THURSDAY MORNING...NOT COINCIDING WITH THE COLD FRONT SURGING SOUTHWARD NEAR THE WYOMING BORDER. SNOW LEVELS A BIT TRICKY AND WILL BE FLUCTUATING DEPENDING ON TIME OF DAY. IN GENERAL TERMS...SNOW LEVELS WILL RANGE FROM 7000 TO 8000 FEET. DIABATIC COOLING PROCESSES COULD RESULT IN WET SNOW TO NEAR THE VALLEY FLOORS LATE WEDNESDAY NIGHT. LATER SHIFTS MAY NEED TO CONSIDER HOISTING WINTER WEATHER ADVISORIES. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 310 PM MST TUE NOV 19 2013 BY THU THE SPLIT IN THE FLOW WILL BECOME MORE DISTINCT AS THE LOW BEGINS TO CLOSE OFF ROUGHLY OVER SOUTHERN CALIFORNIA. A MOIST AND UNSETTLED SOUTHWEST FLOW AHEAD OF THE LOW WILL CONTINUE TO STREAM OVER THE SOUTHWEST CORNER OF THE CONUS...AND ACROSS THE SOUTHERN AND CENTRAL ROCKIES. IN ADDITION...A COLD FRONT ASSOCIATED WITH A NORTHERN BRANCH SHORTWAVE WILL DROP INTO THE NORTHERN EDGE OF THE CWA BY AROUND MIDDAY. WE CAN EXPECT MOUNTAIN SNOW AND THE CHANCE FOR VALLEY RAIN TO CONTINUE THROUGH THU. MOST OF THE AREA WILL BE DOMINATED BY THE MOIST UNSTABLE SOUTHWEST FLOW WITH SOUTH- SOUTHWEST SLOPES FAVORED IN THIS REGIME. BUT THE OROGRAPHICS WILL GENERALLY REMAIN ON THE WEAK SIDE AS THE SOUTHWEST FLOW IS NOT EXPECTED TO BE OVERLY STRONG. OVER THE FAR NORTH HOWEVER...THE AREA IMPACTED BY THE THE NORTHERN BRANCH COLD FRONT WILL SPREAD SOUTH/SOUTHEAST. I EXPECT THAT THERE WILL BE A NICE ENHANCEMENT OF THE PRECIPITATION IN THE VICINITY OF THE FRONT. BUT MODELS INDICATE MUCH DRIER AIR WILL PUSH IN BEHIND THE FRONT. THIS WILL BRING A DOWNTURN IN POPS OVER THE NORTHWEST CORNER BY LATE IN THE AFTERNOON WITH THAT TREND EXTENDING SOUTH-SOUTHWEST THROUGH THE EVENING. ALSO A LOCALIZED AREA OF STRONG NORTHERLY WINDS WILL DEVELOP OVER WESTERN MOFFAT COUNTY INTO THE EASTERN UINTA BASIN DURING THE EVENING. MUCH COLDER TEMPS WILL RESULT IN THIS DRIER AIR BEHIND THE FRONT. MODELS DISAGREE ON JUST HOW FAR SOUTH THIS FRONT WILL REACH BEFORE IT WASHES OUT IN THE SOUTHWEST FLOW AHEAD OF THE SOUTHERN BRANCH LOW. BUT WE CAN CERTAINLY EXPECT MUCH COLDER TEMPS OVER THE FAR NORTH...WITH LESS COOLING AS ONE TRAVELS SOUTH. MODELS AGREE THAT THE LOW WILL STALL IN THE VICINITY OF SAN DIEGO BY EARLY FRIDAY...THEN PRETTY MUCH REMAIN STATIONARY UNTIL EARLY SUNDAY. BY SUN AFTERNOON THE LOW BEGINS TO SLOWLY SHIFT EAST...MAKING IT OVER NM/GFS...TO THE OK PANHANDLE/ECMWF ON MONDAY. THIS KEEPS THE DESERT SOUTHWEST THROUGH THE SOUTHERN CO MOUNTAINS UNDER A MOIST UNSETTLED FLOW AHEAD OF THIS LOW...AND STILL UNSETTLED AS IT PASSES. OVER THE NORTH...MODELS SHOW A COL AREA BETWEEN THE SOUTHERN BRANCH LOW AND THE NORTHERN BRANCH NORTHWESTERLIES WILL MORE OR LESS SET UP OVER WY/NORTHERN CO...AND EXTEND INTO NORTHEAST UT. THIS WILL KEEP THE NORTHERN HALF TO TWO/THIRDS OF THE CWA ON THE DRY SIDE. BUT OUR SOUTHERN EDGE MAY CONTINUE TO SEE PRECIPITATION TROUGH MONDAY. EXPECT THERE WILL BE BREAKS AT TIMES. AND AS ANY EMBEDDED DISTURBANCES MOVE INTO THE THE AREA... SHOWERS WILL BE ENHANCED. MODELS ALL AGREE THAT BY TUE...A DRIER NORTH-NORTHWEST FLOW WILL DOMINATE AREA-WIDE AS A LARGE AREA OF HIGH PRESSURE BUILDS TO OUR WEST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 310 PM MST TUE NOV 19 2013 MOUNTAIN TOPS WILL BE FREQUENTLY OBSCURED THROUGH THE NIGHT WITH WIDESPREAD -RA/-SN NORTH OF A LINE FROM KVEL-KRIL-KASE-K7BM. AREAS OF IFR CIGS/VIS WILL BE POSSIBLE NORTH OF THIS LINE. SNOW LEVELS WILL BE LOWERING TO NEAR THE VALLEY FLOORS OR AROUND 5500 FEET. VFR WITH AREA OF MVFR IS EXPECTED TONIGHT SOUTH OF A LINE FROM KVEL-KGJT-KMTJ-KGUC. MOUNTAIN AREAS MAY BE PARTLY OBSCURED TONIGHT. AFTER 12Z WEDNESDAY...VFR ALL TAF SITES EXCEPT LOWERING CIGS IN THE AFTERNOON. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ SHORT TERM...PF LONG TERM...EH AVIATION...PF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
121 PM EST TUE NOV 19 2013 .SYNOPSIS... LAKE EFFECT SNOW SHOWERS FLURRIES AND EVEN SOME PATCHY FREEZING DRIZZLE WILL GRADUALLY COME TO AN END EARLY THIS AFTERNOON AS HIGH PRESSURE SLOWLY BUILDS INTO THE REGION. BRISK NORTHWEST WINDS COMBINED WITH ABUNDANT CLOUD COVER WILL KEEP TEMPERATURES MAINLY IN THE MIDDLE TO UPPER 30S FOR DAYTIME HIGHS THIS AFTERNOON ACROSS CENTRAL NEW YORK...WITH UPPER 30S TO LOWER 40S ACROSS NORTHEAST PENNSYLVANIA. HIGH PRESSURE WILL THEN DOMINATE THE WEATHER PATTERN WITH DRY AND SLOWLY MODERATING TEMPERATURES EXPECTED THROUGH THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... RADARS STILL SHOW PERSISTENT LAKE EFFECT SNOW SHOWERS/FLURRIES AND DRIZZLE OR EVEN FREEZING DRIZZLE DOWNWIND OF LAKE ONTARIO. THE LOW-LEVEL FLOW WAS ABT FROM 310 DEGREES AND CONTS TO DIRECT LAKE EFFECT MOISTURE INTO THE HILLS OF CENTRAL NY AND FAR NE PA AS OF LATE THIS MORNING. MEANWHILE ALOFT THERE WAS STRG SYNOPTIC SCALE SUBSC ASSCTD WITH THE PASSAGE OF THE UPPER LEVEL TROF AXIS TO THE EAST INTO NEW ENGLAND. MODEL SOUNDINGS BETWEEN THE NAM...GFS AND RAP DIVERGE AS TO HOW THE BNDRY LAYER MOISTURE WILL EVOLVE THIS AFTERNOON INTO THE EVENING. THE NAM RAPIDLY CLEARS OUT THE AREA THIS AFTERNOON WITH SIGNIFICANT LL DRY AIR ADVECTION. THE RAP HOLDS ONTO THE MOISTURE TRAPPED BELOW THE INVERSION INTO THE EVENING HOURS. THE GFS IS IN BETWEEN. LOOKING AT THE VSBL SATELLITE IMAGERY I AM LEANING TWD THE RAP AS THERE WAS SIGNIFICANT CLD CVR N OF LAKE ONTARIO IN ERN ONT AND QUE. SFC DWPTS DO COME DOWN DURG THE AFTERNOON BUT THE SATELLITE IMAGERY STILL SHOWS CLD CVR EVEN WITH THE DROP IN SFC DWPTS UPSTREAM. THIS DRIER SFC AIR WILL ADVECT SOUTHWARD THIS AFTERNOON AND SHUD SNUFF OUT THE LAKE EFFECT SNOW SHOWERS AND DZ/FZDZ BY 19Z THE LATEST. ISSUED AN SPS EARLIER FOR PATCHY FZDZ WHICH IS ASSCTD WITH THE LAKE EFFECT MOISTURE. FZDZ WAS CONFIRMED BY SOME OF OUR FACEBOOK FANS OVER THE HIGHER TERRAIN IN C NY. CLD TOPS OUTSIDE THE LAKE EFFECT SNOW BANDS WERE TOO SHALLOW FOR GLACIATION AND HENCE WE ARE SEEING SOME PATCHY DRIZZLE. HIGHER TERRAIN AREAS REMAIN AT OR BELOW FREEZING WITH PATCHY FZDZ AT TIMES. WILL REISSUE SPS SHORTLY TO HIGHLIGHT THE END OF THE FREEZING DRIZZLE AND PRECIP. CLD CVR SHUD HANG ON DOWNWIND OF LAKE ONTARIO WELL INTO THE EVE AS PER RAP SOUNDINGS. GIVEN THE NW FLOW AND TRAJECTORIES ACRS LAKE ONTARIO AND PRESENT CLD CVR UPSTREAM FROM THE LAKES IN CANADA...HARD TO SEE CLRG IN THE HILLS OF C NY OR FAR NE PA B4 6Z. SO WILL HANG ONTO CLDS SIMILAR TO THE 925 MB RH FIELDS ON THE RAP. EVENTUALLY LATER TONIGHT...THE FLOW TURNS MORE N-NERLY AND THIS IS WHEN CLRG SHUD FINALLY TAKE PLACE. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... A VERY QUIET SHORT TERM PERIOD ANTICIPATED AS HIGH PRESSURE REMAINS IN FIRM CONTROL. BY WEDNESDAY...SE FLOW WILL INCREASE AS HIGH PRESSURE SLIDES TO OUR EAST. EXPECT A WARMER DAY THAN TODAY WITH MOST PLACES EXPECTED TO WARM INTO THE LWR TO MIDDLE 40S FOR HIGHS. SIMILAR CONDITIONS EXPECTED ON THURSDAY AS 850-HPA TEMPS SLOWLY BEGIN WARMING IN DEVELOPING SOUTHWEST FLOW ALOFT. PRECIP TO MAKE A POSSIBLE RETURN THU NGT/EARLY FRI AS WARM AIR ADVECTION INTERACTS WITH A NORTHWARD LIFTING WARM FRONT LIFTING NORTH THROUGH THE OHIO VLY. FOR NOW...HAVE CAPPED POPS IN THE SLGT CHC CATEGORY AS BEST ISENTROPIC ASCENT IS EXPECTED WELL WEST OF OUR REGION. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... 115 PM TUE UPDATE... GENERALLY USED WPC GUIDANCE EXCEPT FOR LOCALIZED ENHANCEMENTS TO POP AND SKY GRIDS FOR WHEN LAKE EFFECT SNOW WILL BE FAVORABLE. INTERESTING PATTERN TAKING SHAPE WITH INCREASING CONFIDENCE FOR SOLID SHOT OF ARCTIC AIR /COLDEST OF SEASON SO FAR/ DURING SECOND HALF OF WEEKEND...AND FOR LAKE EFFECT SNOW. DETAILS OF THAT SNOW OF COURSE WILL BE RESOLVED IN COMING DAYS...BUT IN THE BIG PICTURE IT LOOKS FAVORABLE WITHIN OUR GENERAL AREA AND FORECAST HAS BEEN ADJUSTED ACCORDINGLY WITH BEST CHANCES SUNDAY IN CENTRAL NEW YORK. BEFORE THEN HOWEVER...TIMING OF INITIAL COLD FRONT LOOKS LIKELY FOR SOMETIME FRIDAY NIGHT/EARLY SATURDAY. FRONTAL PRECIPITATION WILL PROBABLY BE MAINLY RAIN. COLD AIR ADVECTION OCCURS DURING THE DAY...ALLOWING LINGERING RAIN SHOWERS TO MIX WITH SNOW...THOUGH AMOUNTS PROBABLY LIMITED BY THEN DUE TO DRY SLOTTING /LOSS OF DEEPER MOISTURE/. ARCTIC FRONT WILL THEN BLAST THROUGH SOMETIME SATURDAY NIGHT...PLUMMETING 850MB TEMPERATURES INTO AT LEAST THE MID TEENS BELOW ZERO ON SUNDAY. WITH THE ARCTIC AIR MASS APPEARING TO ADVECT IN FROM WNW INSTEAD OF THE NORTHERLY DIRECTION...AND WITH THE DENDRITIC GROWTH LAYER BECOMING COMFORTABLY CONTAINED IN THE LOWEST 8 KFT AGL...IT IS A FAVORABLE SET UP FOR ACCUMULATING LAKE EFFECT SNOW INCLUDING UPSTREAM LAKE-TO-LAKE CONNECTIONS SUNDAY INTO PERHAPS SUNDAY NIGHT. IT HAS BEEN COMMON SO FAR THIS SEASON FOR AN INITIALLY VERY COLD AIR MASS IN THE MODELS...TO MODERATE AS THE EVENT GETS CLOSER TO THE POINT THAT IT IS NOT QUITE AS COLD AS ORIGINALLY ANTICIPATED ONCE IT ARRIVES. HOWEVER...IN THIS CASE...THE MODELS HAVE INDICATED THE ARCTIC AIR FOR AT LEAST A FEW RUNS AND ARE MAINTAINING ITS MAGNITUDE IF NOT TRENDING EVEN SLIGHTLY COLDER. BOTH 12Z GFS AND 00Z ECMWF DIVE 1000-500MB THICKNESSES BELOW 510 DECAMETER RANGE. GFS GUIDANCE TEMPERATURES HAVE NOW TRENDED TOWARDS THE VERY COLD ECMWF GUIDANCE VALUES. WE NOW EXPECT MOST LOCATIONS NOT TO GET OUT OF THE 20S FOR HIGHS SUNDAY. DRY SURFACE RIDGE MONDAY WITH WARM AIR ADVECTION ALOFT...BUT LIKELY MUCH MORE MUTED AT THE SURFACE AS WOULD BE TYPICAL ON BACK SIDE OF ARCTIC AIR MASS. SO AFTER MAINLY TEENS FOR LOWS SUNDAY NIGHT...ONLY UPPER 20S TO MID 30S ANTICIPATED FOR HIGHS MONDAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... 18Z UPDATE... DRY AIR IS TRYING TO FURTHER ENTRENCH INTO THE REGION...BUT SHALLOW LAYER OF GREAT LAKES MOISTURE REMAINS TRAPPED UNDER SUBSIDENCE INVERSION FOR AT LEAST A LITTLE LONGER. MVFR...IN SOME CASES AT FUEL ALT REG LEVEL...WILL PESTER THE TERMINALS THIS AFTERNOON THROUGH EVENING /SOME LONGER THAN OTHERS WITH TIMING AS NOTED IN SPECIFIC TAFS/. LAKE EFFECT FLURRIES ALSO STILL POSSIBLE INITIALLY FOR KITH-KBGM. NNW WINDS GUSTING TO 15-20 KTS THIS AFTERNOON...THEN SUBSIDING TO LIGHT NE OR VARIABLE OVERNIGHT INTO WEDNESDAY MORNING. AS THAT FLOW VEERS LIGHT NORTHEASTERLY OVERNIGHT...ANY REMAINING MVFR CIGS WILL SCATTER OUT AND CLEAR. VFR FOR REMAINDER OF TAF PERIOD AS HIGH PRESSURE TAKES CHARGE. OUTLOOK... WED THROUGH THU...VFR. FRI...VFR/MVFR. SHOWERS POSSIBLE. FRI NGT/SAT...RESTRICTIONS POSSIBLE FROM SHRA AS COLD FRONT PASSES. SAT NGT/SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT SHSN ESPECIALLY CENTRAL NY TERMINALS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJN NEAR TERM...DJN SHORT TERM...CMG LONG TERM...MDP AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1127 AM EST TUE NOV 19 2013 .SYNOPSIS... LAKE EFFECT SNOW SHOWERS FLURRIES AND EVEN SOME PATCHY FREEZING DRIZZLE WILL GRADUALLY COME TO AN END EARLY THIS AFTERNOON AS HIGH PRESSURE SLOWLY BUILDS INTO THE REGION. BRISK NORTHWEST WINDS COMBINED WITH ABUNDANT CLOUD COVER WILL KEEP TEMPERATURES MAINLY IN THE MIDDLE TO UPPER 30S FOR DAYTIME HIGHS THIS AFTERNOON ACROSS CENTRAL NEW YORK...WITH UPPER 30S TO LOWER 40S ACROSS NORTHEAST PENNSYLVANIA. HIGH PRESSURE WILL THEN DOMINATE THE WEATHER PATTERN ...WITH DRY AND SLOWLY MODERATING TEMPERATURES EXPECTED THROUGH THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... RADARS STILL SHOW PERSISTENT LAKE EFFECT SNOW SHOWERS/FLURRIES AND DRIZZLE OR EVEN FREEZING DRIZZLE DOWNWIND OF LAKE ONTARIO. THE LOW-LEVEL FLOW WAS ABT FROM 310 DEGREES AND CONTS TO DIRECT LAKE EFFECT MOISTURE INTO THE HILLS OF CENTRAL NY AND FAR NE PA AS OF LATE THIS MORNING. MEANWHILE ALOFT THERE WAS STRG SYNOPTIC SCALE SUBSC ASSCTD WITH THE PASSAGE OF THE UPPER LEVEL TROF AXIS TO THE EAST INTO NEW ENGLAND. MODEL SOUNDINGS BETWEEN THE NAM...GFS AND RAP DIVERGE AS TO HOW THE BNDRY LAYER MOISTURE WILL EVOLVE THIS AFTERNOON INTO THE EVENING. THE NAM RAPIDLY CLEARS OUT THE AREA THIS AFTERNOON WITH SIGNIFICANT LL DRY AIR ADVECTION. THE RAP HOLDS ONTO THE MOISTURE TRAPPED BELOW THE INVERSION INTO THE EVENING HOURS. THE GFS IS IN BETWEEN. LOOKING AT THE VSBL SATELLITE IMAGERY I AM LEANING TWD THE RAP AS THERE WAS SIGNIFICANT CLD CVR N OF LAKE ONTARIO IN ERN ONT AND QUE. SFC DWPTS DO COME DOWN DURG THE AFTERNOON BUT THE SATELLITE IMAGERY STILL SHOWS CLD CVR EVEN WITH THE DROP IN SFC DWPTS UPSTREAM. THIS DRIER SFC AIR WILL ADVECT SOUTHWARD THIS AFTERNOON AND SHUD SNUFF OUT THE LAKE EFFECT SNOW SHOWERS AND DZ/FZDZ BY 19Z THE LATEST. ISSUED AN SPS EARLIER FOR PATCHY FZDZ WHICH IS ASSCTD WITH THE LAKE EFFECT MOISTURE. FZDZ WAS CONFIRMED BY SOME OF OUR FACEBOOK FANS OVER THE HIGHER TERRAIN IN C NY. CLD TOPS OUTSIDE THE LAKE EFFECT SNOW BANDS WERE TOO SHALLOW FOR GLACIATION AND HENCE WE ARE SEEING SOME PATCHY DRIZZLE. HIGHER TERRAIN AREAS REMAIN AT OR BELOW FREEZING WITH PATCHY FZDZ AT TIMES. WILL REISSUE SPS SHORTLY TO HIGHLIGHT THE END OF THE FREEZING DRIZZLE AND PRECIP. CLD CVR SHUD HANG ON DOWNWIND OF LAKE ONTARIO WELL INTO THE EVE AS PER RAP SOUNDINGS. GIVEN THE NW FLOW AND TRAJECTORIES ACRS LAKE ONTARIO AND PRESENT CLD CVR UPSTREAM FROM THE LAKES IN CANADA...HARD TO SEE CLRG IN THE HILLS OF C NY OR FAR NE PA B4 6Z. SO WILL HANG ONTO CLDS SIMILAR TO THE 925 MB RH FIELDS ON THE RAP. EVENTUALLY LATER TONIGHT...THE FLOW TURNS MORE N-NERLY AND THIS IS WHEN CLRG SHUD FINALLY TAKE PLACE. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... A VERY QUIET SHORT TERM PERIOD ANTICIPATED AS HIGH PRESSURE REMAINS IN FIRM CONTROL. BY WEDNESDAY...SE FLOW WILL INCREASE AS HIGH PRESSURE SLIDES TO OUR EAST. EXPECT A WARMER DAY THAN TODAY WITH MOST PLACES EXPECTED TO WARM INTO THE LWR TO MIDDLE 40S FOR HIGHS. SIMILAR CONDITIONS EXPECTED ON THURSDAY AS 850-HPA TEMPS SLOWLY BEGIN WARMING IN DEVELOPING SOUTHWEST FLOW ALOFT. PRECIP TO MAKE A POSSIBLE RETURN THU NGT/EARLY FRI AS WARM AIR ADVECTION INTERACTS WITH A NORTHWARD LIFTING WARM FRONT LIFTING NORTH THROUGH THE OHIO VLY. FOR NOW...HAVE CAPPED POPS IN THE SLGT CHC CATEGORY AS BEST ISENTROPIC ASCENT IS EXPECTED WELL WEST OF OUR REGION. && .LONG TERM /FRIDAY THROUGH MONDAY/... THE LATEST GFS AND ECMWF MODEL RUNS SUGGEST AT LEAST A SHORT TERM PATTERN CHANGE FOR THE UPCOMING WEEKEND AS A HIGH AMPLITUDE 500 MB TROF IS FORECAST TO DIG ACROSS THE NORTHEASTERN CONUS. DIFFERENCES EXIST IN TIMING AND STRENGTH OF THE FEATURES ALOFT AND AT THE SURFACE...BUT SUFFICE IT TO SAY THE FRI-SAT TIME FRAME LOOKS TO HAVE A HIGH POTENTIAL FOR INCLEMENT WEATHER. THE SFC LOW TRACK CURRENTLY SUGGESTS A PASSAGE RIGHT OVER THE CWA WHICH COULD BRING SOME WINTRY PRECIP TO THE REGION... ALTHOUGH THERMAL PROFILES ONLY SEEM TO SUGGEST A RAIN OR WET SNOW ENVIRONMENT FROM FRI-SAT AS WET BULB TEMPS APPEAR TO BE WELL ABOVE ZERO IN THE BOUNDARY LAYER. IN SOME RESPECTS...THE MOS GUIDANCE TEMPS MAY BE A BIT TOO COLD AT NIGHT ON FRIDAY NIGHT...AND AGAIN SATURDAY NIGHT. AT THIS TIME THERE REMAINS TOO MUCH UNCERTAINTY IN HOW MUCH PRE-PRECIPITATION COOLING WOULD TAKE PLACE FRI EVENING...AND HOW MUCH CAA COOLING MIGHT OCCUR BEFORE SUNRISE ON SUNDAY AFTER THE FROPA TO MAKE ANY SIGNIFICANT DEVIATIONS FROM THE MOS NUMBERS...OR OUR PREVIOUS FORECAST. SIGNIFICANTLY COLDER AIR DOES APPEAR TO BE DRAWN SOUTH AT SOME POINT DURING THE LATTER HALF OF THE WEEKEND INTO NEXT WEEK WITH DAILY TEMPS AVERAGING WELL BELOW NORMAL ALONG WITH GOOD PROBABILITIES FOR NORTHWESTERLY ORIENTED LAKE EFFECT SNOWS. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... GNRL VFR CONDS WILL CONT THRU THE TAF PD. NW FLOW OF CAA WILL PRODUCE CLDS AND SOME LGT LE SNOW AND RAIN SHWRS EARLY. SKIES WILL CLR AFT 21Z AS DRIER AIR MVES. WINDS WILL CONT TO BE GUSTY THRU THE DAYLIGHT HRS...THEN BECOME LGTR AFT 00Z THE HIPRES BLDS INTO THE AREA. OUTLOOK... WED THROUGH THU...VFR. FRI...VFR/MVFR. SHOWERS POSSIBLE. SAT...MVFR. PERIODS OF RAIN POSSIBLE. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJN NEAR TERM...DJN SHORT TERM...CMG LONG TERM...JAB AVIATION...DGM
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
319 PM CST TUE NOV 19 2013 .SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT QUITE A CHANGE COMING IN THE SHORT TERM FROM THIS AFTERNOON THROUGH THURSDAY NIGHT. FOR TONIGHT...EXPECT RR QUAD JET INDUCED HIGH CLOUDS TO MOVE ON THIS EVENING WHILE MORE HIGH CLOUDS SPREAD IN FROM THE WEST. BREEZY SOUTH WINDS WILL DECREASE THIS EVENING WITH WINDS BECOMING NORTHWEST THROUGH NORTH BY MORNING AS A WEAK SURFACE LOW PRESSURE TROUGH MOVES THROUGH. TEMPERATURES WILL NOT FALL OFF MUCH TONIGHT WITH THE MILD AIR MASS REMAINING. LOWS ARE EXPECTED TO RANGE FROM AROUND 30 DEGREES NORTH CENTRAL TO THE MID TO UPPER 30S IN THE WATERTOWN/ORTONVILLE AREA. OTHERWISE...HIGHS ON WEDNESDAY WILL LIKELY BE IN THE MORNING AS AN ARCTIC BOUNDARY PUSHES IN DURING THE AFTERNOON WITH NORTH WINDS PICKING UP AND TEMPERATURES FALLING ACROSS THE NORTH. EXPECT WINDS TO BECOME BLUSTERY AT 15 TO 30 MPH WITH HIGHER GUSTS. THE OTHER ISSUE WILL BE THE LIGHT SNOW DEVELOPING ALONG AND BEHIND THE SURFACE COLD FRONT. MID LEVEL FRONTOGENESIS ALONG WITH SOME JET STREAK HELP WILL BRING LIGHT SNOW TO NORTH CENTRAL SOUTH DAKOTA BY LATE AFTERNOON. THE MODELS INDICATE LESSER AMOUNTS OF LIFT AND QPF AS THIS REGION DESCENDS SOUTH ACROSS OUR CWA THROUGH WEDNESDAY NIGHT. THUS...HAVE LIKELY CHANCES EARLY DIMINISHING THROUGH THE NIGHT. SNOWFALL AMOUNTS SHOULD BE GENERALLY BELOW AN INCH BY THURSDAY MORNING. ARCTIC AIR ENCOMPASSES THE ENTIRE CWA ON THURSDAY WITH LESS WIND. MUCH BELOW NORMAL TEMPERATURES ARE EXPECTED ON THURSDAY WITH HIGHS IN THE 20 TO 25 DEGREE RANGE ACROSS THE CWA. THE MODELS THEN SHOW AN UPPER LEVEL LOW PRESSURE TROUGH AND THE ASSOCIATED LIFT SWINGING OVER THE REGION THURSDAY AND THURSDAY EVENING. WITH MUCH OF THE NORTHERN CWA UNDER LOW LEVEL DRY AIR...EXPECT THE BEST CHANCES OF LIGHT SNOW WITH THIS SYSTEM TO BE FROM PIR TO HURON TO ATY. EXPECT MORE CLOUD COVER AND LIGHT SNOW TO SPREAD QUICKLY WEST TO EAST ON THURSDAY ACROSS MAINLY THE SOUTHERN CWA. COULD HAVE SOME MORE SNOWFALL ACCUMULATIONS OF AN INCH OR TWO. THE LIGHT SNOW WILL END QUICKLY THURSDAY NIGHT WITH CLEARING SKIES IN BEHIND AND SINGLE DIGIT LOWS. .LONG TERM...FRIDAY THROUGH TUESDAY NORTHWEST FLOW ALOFT WILL DOMINATE THE LONG TERM PORTION OF THE FORECAST. A SURFACE LOW PRESSURE SYSTEM PASSING ACROSS THE GREAT LAKES REGION ON FRIDAY WILL ALLOW FOR BITTER ARCTIC COLD TEMPERATURES TO FILTER INTO THE AREA BY FRIDAY NIGHT. BY 12Z SATURDAY TEMPERATURES AT H85 RANGE IN THE MID TO UPPER TEENS BELOW ZERO...WHICH IS APPROACHING TWO STANDARD DEVIATIONS BELOW NORMAL. LOW TEMPERATURES SHOULD EASILY DROP TO THE SINGLE DIGITS ON EITHER SIDE OF ZERO BY SATURDAY MORNING. THE SURFACE HIGH PRESSURE WILL EXIT THE REGION ON SATURDAY NIGHT ALLOWING FOR WAA TO SPREAD INTO THE CWA. TEMPERATURES THROUGH THE REST OF THE PERIOD WILL BE AROUND NORMAL...DUE TO EXPECTED SNOW COVER. NO SIGNIFICANT PRECIPITATION CHANCES ARE EXPECTED FOR THE PERIOD. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS PREVAILING VFR CONDITIONS ARE EXPECTED FOR ALL TERMINALS THROUGH THE VALID TAF PERIOD. AN AREA OF LOW PRESSURE WILL PASS THROUGH THE REGION DRY WITH ONLY HIGH CIRRUS EXPECTED. STRONG SOUTHERLY WINDS AFFECTING THE TERMINALS OF KABR/KATY WILL DIMINISH BELOW 12 KNOTS LATER THIS EVENING. WINDS SHOULD BE LIGHT AND VARIABLE THROUGH THE MORNING HOURS ON WEDNESDAY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...MOHR LONG TERM...SD AVIATION...SD WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1128 AM CST TUE NOV 19 2013 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 348 AM CST TUE NOV 19 2013 AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS. THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE. FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO 50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A TENTH OF AND INCH. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 348 AM CST TUE NOV 19 2013 ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY DECLINE DURING THE EVENING. ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS... ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT. HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE. ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS WILL BE LESS THAN A HALF INCH. ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECMWF IS A BIT LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S. SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE ALL BLEND MAXIMUM TEMPERATURES. SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN COLDER. LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED WITH THE ALL BLEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY) ISSUED AT 1128 AM CST TUE NOV 19 2013 PRESSURE GRADIENT ACROSS THE UPPER MIDWEST WILL CONTINUE TO TIGHTEN FOR THIS AFTERNOON/TONIGHT AS LOW PRESSURE DEEPENS INTO THE CENTRAL/ NORTHERN PLAINS. SOUTHEAST TO SOUTH GRADIENT WINDS ARE GOING TO INCREASE INTO THE 10-20KT G20-30KT RANGE THRU THE AFTERNOON AND CONTINUE TONIGHT INTO WED. WINDS WILL INCREASE ON TOP OF THE NOCTURNAL INVERSION /AROUND 2K FT/ TONIGHT...TO 50-60KTS. CONTINUED THE MENTION OF LLWS AT BOTH KRST/KLSE IN THE 03Z-15Z TIME-FRAME FOR THE RAPID SPEED AND DIRECTIONAL CHANGE OF THE WIND IN THE SFC-2K FT LAYER. CLOUDS TODAY WILL BE SCT-BKN HIGH CLOUDS. SOME MID LEVEL MOISTURE ARRIVES ON THE SOUTHERLY FLOW TONIGHT...WITH CLOUDS EXPECTED TO BE IN THE 8K-10K FT RANGE. MOISTURE CONTINUES TO DEEPEN ON WED ALONG WITH AN INCREASE OF LIFTING. MODEL CONSENSUS CONTINUE TO PRODUCE SOME -RA IN/AROUND THE AREA BY LATE MORNING. INCLUDED VCSH AND CIGS IN THE 6K-7K FT RANGE AFTER 15Z WED. ANY PRECIP LATE WED MORNING LOOKS TO BE LIGHT ENOUGH TO HAVE MINIMAL IMPACT ON VSBYS. BIT MORE WIDESPREAD -RA WED AFTERNOON MAY PRODUCE SOME MVFR VSBYS AFTER 18Z WED. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM....BOYNE AVIATION.....RRS