Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/19/14


AREA FORECAST DISCUSSION
NWS ALBANY NY
928 PM EST TUE NOV 18 2014 .SYNOPSIS... BLUSTERY AND COLD CONDITIONS WILL PREVAIL THROUGH THE REST OF THE WORK WEEK. LAKE EFFECT SNOW WILL SHIFT SOUTHWARD INTO THE WESTERN ADIRONDACKS TONIGHT INTO WEDNESDAY...WHILE THE REST OF THE AREA WILL BE DRY. A FAST MOVING STORM WILL TRACK THROUGH SOUTHEAST CANADA WEDNESDAY NIGHT INTO THURSDAY...BRINGING SOME SNOW SHOWERS. ANOTHER SURGE OF COLD AIR WILL FOLLOW IN WAKE OF THIS SYSTEM WITH ADDITIONAL LAKE EFFECT SNOW DEVELOPING ACROSS THE WESTERN ADIRONDACKS. HIGH PRESSURE WILL BUILD TO THE EASTERN SEABOARD TO END THE WEEK WITH MODERATING TEMPERATURES FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... LAKE EFFECT WARNING FOR NORTHERN HERKIMER AND ADVISORY FOR HAMILTON COUNTY CONTINUES. MIDLEVEL VORTICITY CENTER SEEN IN SATELLITE IMAGERY IS TRACKING ALONG THE CANADA/U.S. BORDER AND BOUNDARY LAYER FLOW IS TURNING MORE WESTERLY BEHIND THIS VORTICITY CENTER. THIS CAN BE SEEN IN 00Z AREA SOUNDINGS AND UPPER AIR DATA. AS THE FLOW TURNS MORE WESTERLY...THE LAKE EFFECT BAND WILL SHIFT SOUTH INTO NORTHERN HERKIMER AND HAMILTON COUNTIES...WHICH CAN BE SEEN JUST BEGINNING TO HAPPEN IN RADAR DATA. JUST SOME MINOR ADJUSTMENTS TO THE FORECAST BASED ON THE LATEST OBSERVATIONS AND TRENDS. MORE DETAILS ABOUT THE LAKE EFFECT AND COLD WEATHER IN THE REST OF THE REGION IN THE PREVIOUS AFD BELOW... WE ARE STILL WAITING FOR AN INTENSE...WELL DEFINED SINGLE LAKE EFFECT SNOW BAND CURRENTLY LOCATED JUST NORTH AND WEST OF THE HERKIMER AND LEWIS/ST LAWRENCE COUNTIES TRIPLE POINT...TO SHIFT SOUTHWARD. RADAR TRENDS OVER THE PAST FEW HOURS CONTINUE TO SHOW A STEADY-STATE POSITION TO THE BAND WITH A PERSISTENT 250 FLOW TRAJECTORY. BY EARLY TO MID EVENING...WE ARE ANTICIPATING THE BAND TO FINALLY MOVE SOUTHWARD AND IMPACT AT LEAST THE FAR NORTHERN PORTIONS OF HERKIMER COUNTY NORTH OF ROUTE 28...AS THE FLOW SHIFTS TO A 260-270 TRAJECTORY. MESOSCALE MODELS SUCH AS THE HRRR AND ALY 5KM WRF DEPICTS THE BAND SLOWLY DRIFTING S/SE AND EVENTUALLY IMPACTING THE OLD FORGE AREA ALONG ROUTE 28 BY AROUND MIDNIGHT AND THROUGH THE OVERNIGHT HOURS. LATER THIS EVENING INTO THE OVERNIGHT HOURS WE ARE ALSO EXPECTING AN UPSTREAM MOISTURE CONNECTION TO GEORGIAN BAY TO DEVELOP...WHICH WILL AID IN ALLOWING THE BAND TO IMPACT MUCH OF NORTHERN HERKIMER COUNTY BASED ON LOCAL CSTAR RESEARCH. THERE IS STILL FORECAST TO BE MODERATE DIRECTIONAL SHEAR ALONG WITH EXTREME LAKE INDUCED INSTABILITY...WHICH TENDS TO MITIGATE THE INLAND EXTENT. THUS WE ARE CONFIDENT IN NORTHERN HERKIMER COUNTY RECEIVING THE HEAVIEST SNOW MAINLY NORTH OLD FORGE WHERE 6-12 INCHES IS EXPECTED...WITH 4-8 INCHES FARTHER SOUTH ALONG AND JUST SOUTH OF ROUTE 28. BASED ON MITIGATING FACTORS...THE MOST INTENSE PORTION OF THE BAND IS NOT EXPECTED TO REACH HAMILTON COUNTY WHERE 2-6 INCHES OF ACCUMULATION ARE POSSIBLE MAINLY AROUND INLET...BUT LESSER AMOUNTS FARTHER EAST TOWARDS INDIAN LAKE. OUTSIDE OF LAKE EFFECT SNOW IN THE WESTERN ADIRONDACKS...THE REST OF THE AREA WILL BE COLD...DRY AND CONTINUED BLUSTERY WITH A GUSTY WESTERLY WIND PERSISTING. TEMPERATURES WILL BE WELL BELOW NORMA TONIGHT...WITH TEENS EXPECTED FOR LOWS AND WIND CHILLS IN THE 10 BELOW ZERO TO 10 ABOVE RANGE. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... LAKE EFFECT SNOW BAND IMPACTING THE NORTHERN HALF OF HERKIMER COUNTY AND POSSIBLY INTO WESTERN HAMILTON COUNTY TO START THE MORNING...WILL DRIFT NORTH OF THE AREA BY NOON IN RESPONSE TO THE LOW LEVEL FLOW BECOMING MORE SOUTHERLY AHEAD OF A TROUGH OF LOW PRESSURE MOVING ACROSS THE UPPER GREAT LAKES. SO WILL MENTION LIKELY TO CATEGORICAL POPS FOR THE WESTERN ADIRONDACKS INITIALLY...THEN WILL DECREASE SIGNIFICANTLY BY AFTERNOON AS SURFACE RIDGING WILL KEEP THE AREA DRY. TEMPERATURES WILL CONTINUE TO BE WELL BELOW NORMAL WITH READINGS EXPECTED TO BE VERY SIMILAR TO TUESDAY. HIGHS EXPECTED TO BE AROUND 15 DEGREES BELOW NORMAL. AS THE AFOREMENTIONED TROUGH THEN TRANSLATES EASTWARD THROUGH THE EASTERN GREAT LAKES WEDNESDAY NIGHT...SOME WEAK LIFT AHEAD OF THE THIS SYSTEM WILL RESULT IN SOME SNOW SHOWERS DEVELOPING. BEST CHANCE FOR ANY MEASURABLE SNOWFALL WILL BE FOR AREAS NORTH OF THE CAPITAL REGION...WHERE S/SW FLOW WILL ALLOW FOR UPSLOPE FLOW NEAR THE FOOTHILLS OF THE SOUTHERN ADIRONDACKS. ANY ACCUMULATIONS WILL BE VERY MINOR AND FOR NOW WILL ONLY MENTION CHANCE POPS. ANOTHER COLD NIGHT IN STORE...ALTHOUGH A FEW DEGREES "WARMER" DUE TO A DEVELOPING SOUTHERLY WIND AT THE SURFACE. ON THURSDAY LOW PRESSURE IS EXPECTED TO DEEPEN OVER SOUTHERN QUEBEC IN RESPONSE TO A POTENT UPPER LOW MOVING ACROSS THE UPPER GREAT LAKES AND SOUTHEAST ONTARIO. AS THIS SYSTEM TRACKS EAST...ANOTHER SHOT OF DEEP COLD AIR WILL FILTER INTO THE REGION...SHIFTING THE FLOW TO MORE OF A WESTERLY DIRECTION. WITH LAKE ONTARIO WATER TEMPS REMAINING RELATIVELY WARM...THIS WILL ALLOW FOR LAKE EFFECT SNOW TO DEVELOP DOWNWIND OF THE LAKE AND POTENTIALLY IMPACT THE WESTERN ADIRONDACKS DURING THE DAY THURSDAY. WILL MENTION THIS POTENTIAL IN THE HWO FOR NORTHERN HERKIMER AND HAMILTON COUNTIES. AS THE FLOW BECOMES WNW THURSDAY NIGHT...LAKE EFFECT SNOW MAY IMPACT PORTIONS OF CENTRAL/SOUTHERN HERKIMER COUNTY AND EVEN THE MOHAWK VALLEY BUT THIS IS HIGHLY UNCERTAIN AT THIS TIME. OUTSIDE OF LAKE EFFECT...ONCE AGAIN BLUSTERY AND COLD CONDITIONS ARE EXPECTED WITH TEMPERATURES CONTINUING TO RUN WELL BELOW NORMAL FOR MID TO LATE NOVEMBER. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MODERATING TEMPS IN THE LONG TERM WITH SOME INCLEMENT WEATHER TO CLOSE THE WEEKEND AND OPEN NEXT WEEK. FRIDAY-FRIDAY NIGHT...THE LAST REMNANTS OF LAKE EFFECT SNOW WILL IMPACT LOCATIONS WEST OF THE HUDSON VALLEY DURING THE DAY. THE UPPER LEVEL TROUGH AXIS SWINGS ACROSS THE REGION WITH SFC HIGH PRESSURE BUILDING IN FROM THE OHIO VALLEY AND MID ATLANTIC REGION. THE LOW AND MID LEVEL FLOW WILL BECOME ANTICYCLONIC WITH A LOWERING SUBSIDENCE INVERSION. H850 TEMPS WILL STILL BE BELOW NORMAL IN THE -13C TO -15C RANGE. HIGHS WILL ONLY BE IN THE 20S TO L30S WITH LOWS IN THE TEENS AND LOWER 20S WITH SOME SINGLE DIGITS IN THE SRN DACKS. SATURDAY-SATURDAY NIGHT...A QUIET START TO THE WEEKEND WITH HIGH PRESSURE BUILDING IN FROM THE SOUTH. A WARM FRONT WILL LIFT WELL NORTH AND WEST OF THE REGION. MID AND HIGH CLOUDS WILL INCREASE LATE IN THE DAY. SOME THERMAL ADVECTION SNOW SHOWERS WILL MOVE IN DURING THE NIGHT TIME PERIOD. HIGHS WILL STILL RUN BELOW NORMAL BY 10 DEGREES WITH MILDER MINS IN THE WARM ADVECTION REGIME. SUNDAY INTO MONDAY...A STORM SYSTEM APPROACHES FROM THE CNTRL MS RIVER VALLEY. THERE ARE SOME TIMING DIFFERENCES BETWEEN THE ECMWF...CAN GGEM...GFS...AND GEFS. AS THE WAVE LIFTS N/NE INTO THE GREAT LAKES REGION...STRONG ISENTROPIC LIFT WILL INCREASE AHEAD OF THE WARM FRONT. THE STRONG QG LIFT GENERATED BY THE DIFFERENTIAL THICKNESS ADVECTION WILL PROMOTE PERIODS OF SHOWERS LATE SUNDAY INTO MONDAY. TEMPS SOAR BACK ABOVE NORMAL WITH HIGHS REBOUNDING FROM THE U30S TO L50S ON SUNDAY...TO POTENTIALLY WIDESPREAD 50S TO L60S ON MONDAY...AS THE CYCLONE PASSES WELL WEST OF THE REGION INTO THE SE ONTARIO AND QUEBEC. THE HIGHEST POPS WERE PLACED IN THE FORECAST SUNDAY NIGHT INTO MONDAY WITH LIKELY AND HIGH CHC VALUES. MONDAY NIGHT INTO TUESDAY...A POSITIVELY TILTED LONGWAVE TROUGH AXIS REMAINS UPSTREAM...AND THE COLD FRONT TO THE SYSTEM GRADUALLY MOVES THROUGH ON TUESDAY. MORE CHANCES OF SHOWERS CONTINUE WITH TEMPS GRADUALLY LOWERING TO NORMAL TO BELOW NORMAL READINGS FOR LATE NOVEMBER. OVERALL...TEMPS COULD AVERAGE NEAR NORMAL IN THE LONG TERM DUE TO THE LATE WEEKEND/EARLY WEEK WARM UP AND PCPN ABOVE NORMAL. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS ARE EXPECTED THE NEXT 24 HOURS...AS A W TO NW FLOW ALOFT WILL DOMINATE WITH A STRONG UPPER LEVEL TROUGH OVER THE ERN CONUS. SCATTERED STRATOCUMULUS WILL OCCUR THIS EVENING WITH BRISK SW TO W WINDS OF 10 TO 15 KT WITH SOME GUSTS 20 TO 25 KT DIMINISHING THIS EVENING TO AROUND 10 KT. THE SKIES WILL CLEAR TONIGHT...AND THE WINDS WILL INCREASE SLIGHTLY AT 10-15 KTS AS NIGHTTIME SUBSIDENCE HELPS MIX SOME WINDS TO THE SURFACE. A FEW GUSTS IN THE 20-25 KT RANGE ARE POSSIBLE AT KALB AND KPSF. THE WINDS WILL CONTINUE TO BACK TO S TO SW AHEAD OF THE NEXT DISTURBANCE LATE TOMORROW MORNING AND INTO THE AFTERNOON. SOME MID AND HIGH CLOUDS WILL ALSO INCREASE TOWARDS NOONTIME. WINDS SHOULD EASE TO LESS THAN 10 KT AFTER 21Z. OUTLOOK... WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. THURSDAY: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: LOW OPERATIONAL IMPACT. BREEZY. CHANCE OF SHSN. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. && .HYDROLOGY... NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED THROUGH AT LEAST THE NEXT FIVE DAYS. MAINLY DRY CONDITIONS ARE EXPECTED ACROSS THE HSA...EXCEPT FOR LAKE EFFECT SNOW TONIGHT INTO WEDNESDAY ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. ADDITIONAL LIGHT SNOW SHOWERS ARE POSSIBLE WEDNESDAY NIGHT INTO THURSDAY...WITH MORE LAKE EFFECT SNOW ON THURSDAY FOR FAVORED AREAS. TEMPERATURES WILL BE BELOW FREEZING FOR MUCH OF THE PERIOD...SO ICE FORMATION IS EXPECTED ON SOME BODIES OF WATER AND ESPECIALLY SHALLOWER LAKES...PONDS AND STREAMS. 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...LAKE EFFECT SNOW WARNING UNTIL NOON EST WEDNESDAY FOR NYZ032. LAKE EFFECT SNOW ADVISORY UNTIL NOON EST WEDNESDAY FOR NYZ033. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...NAS/JPV SHORT TERM...JPV LONG TERM...WASULA AVIATION...NAS HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
611 PM EST TUE NOV 18 2014 .SYNOPSIS... BLUSTERY AND COLD CONDITIONS WILL PREVAIL THROUGH THE REST OF THE WORK WEEK. LAKE EFFECT SNOW WILL SHIFT SOUTHWARD INTO THE WESTERN ADIRONDACKS TONIGHT INTO WEDNESDAY...WHILE THE REST OF THE AREA WILL BE DRY. A FAST MOVING STORM WILL TRACK THROUGH SOUTHEAST CANADA WEDNESDAY NIGHT INTO THURSDAY...BRINGING SOME SNOW SHOWERS. ANOTHER SURGE OF COLD AIR WILL FOLLOW IN WAKE OF THIS SYSTEM WITH ADDITIONAL LAKE EFFECT SNOW DEVELOPING ACROSS THE WESTERN ADIRONDACKS. HIGH PRESSURE WILL BUILD TO THE EASTERN SEABOARD TO END THE WEEK WITH MODERATING TEMPERATURES FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... LAKE EFFECT WARNING FOR NORTHERN HERKIMER AND ADVISORY FOR HAMILTON COUNTIES CONTINUES. THE BAND EXTENDING JUST TO THE NORTHERN BORDER OF BOTH COUNTIES IS SLOWLY SHIFTING SOUTH. JUST SOME MINOR ADJUSTMENTS TO THE TIMING OF THE SOUTHWARD SHIFT OF THE BAND BASED ON CURRENT OBSERVATIONS AND TRENDS. MESOSCALE MODELS IN GOOD AGREEMENT ON THE TIMING. MORE DETAILS ABOUT THE LAKE EFFECT AND COLD WEATHER IN THE REST OF THE REGION IN THE PREVIOUS AFD BELOW... WE ARE STILL WAITING FOR AN INTENSE...WELL DEFINED SINGLE LAKE EFFECT SNOW BAND CURRENTLY LOCATED JUST NORTH AND WEST OF THE HERKIMER AND LEWIS/ST LAWRENCE COUNTIES TRIPLE POINT...TO SHIFT SOUTHWARD. RADAR TRENDS OVER THE PAST FEW HOURS CONTINUE TO SHOW A STEADY-STATE POSITION TO THE BAND WITH A PERSISTENT 250 FLOW TRAJECTORY. BY EARLY TO MID EVENING...WE ARE ANTICIPATING THE BAND TO FINALLY MOVE SOUTHWARD AND IMPACT AT LEAST THE FAR NORTHERN PORTIONS OF HERKIMER COUNTY NORTH OF ROUTE 28...AS THE FLOW SHIFTS TO A 260-270 TRAJECTORY. MESOSCALE MODELS SUCH AS THE HRRR AND ALY 5KM WRF DEPICTS THE BAND SLOWLY DRIFTING S/SE AND EVENTUALLY IMPACTING THE OLD FORGE AREA ALONG ROUTE 28 BY AROUND MIDNIGHT AND THROUGH THE OVERNIGHT HOURS. LATER THIS EVENING INTO THE OVERNIGHT HOURS WE ARE ALSO EXPECTING AN UPSTREAM MOISTURE CONNECTION TO GEORGIAN BAY TO DEVELOP...WHICH WILL AID IN ALLOWING THE BAND TO IMPACT MUCH OF NORTHERN HERKIMER COUNTY BASED ON LOCAL CSTAR RESEARCH. THERE IS STILL FORECAST TO BE MODERATE DIRECTIONAL SHEAR ALONG WITH EXTREME LAKE INDUCED INSTABILITY...WHICH TENDS TO MITIGATE THE INLAND EXTENT. THUS WE ARE CONFIDENT IN NORTHERN HERKIMER COUNTY RECEIVING THE HEAVIEST SNOW MAINLY NORTH OLD FORGE WHERE 6-12 INCHES IS EXPECTED...WITH 4-8 INCHES FARTHER SOUTH ALONG AND JUST SOUTH OF ROUTE 28. BASED ON MITIGATING FACTORS...THE MOST INTENSE PORTION OF THE BAND IS NOT EXPECTED TO REACH HAMILTON COUNTY WHERE 2-6 INCHES OF ACCUMULATION ARE POSSIBLE MAINLY AROUND INLET...BUT LESSER AMOUNTS FARTHER EAST TOWARDS INDIAN LAKE. OUTSIDE OF LAKE EFFECT SNOW IN THE WESTERN ADIRONDACKS...THE REST OF THE AREA WILL BE COLD...DRY AND CONTINUED BLUSTERY WITH A GUSTY WESTERLY WIND PERSISTING. TEMPERATURES WILL BE WELL BELOW NORMA TONIGHT...WITH TEENS EXPECTED FOR LOWS AND WIND CHILLS IN THE 10 BELOW ZERO TO 10 ABOVE RANGE. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... LAKE EFFECT SNOW BAND IMPACTING THE NORTHERN HALF OF HERKIMER COUNTY AND POSSIBLY INTO WESTERN HAMILTON COUNTY TO START THE MORNING...WILL DRIFT NORTH OF THE AREA BY NOON IN RESPONSE TO THE LOW LEVEL FLOW BECOMING MORE SOUTHERLY AHEAD OF A TROUGH OF LOW PRESSURE MOVING ACROSS THE UPPER GREAT LAKES. SO WILL MENTION LIKELY TO CATEGORICAL POPS FOR THE WESTERN ADIRONDACKS INITIALLY...THEN WILL DECREASE SIGNIFICANTLY BY AFTERNOON AS SURFACE RIDGING WILL KEEP THE AREA DRY. TEMPERATURES WILL CONTINUE TO BE WELL BELOW NORMAL WITH READINGS EXPECTED TO BE VERY SIMILAR TO TUESDAY. HIGHS EXPECTED TO BE AROUND 15 DEGREES BELOW NORMAL. AS THE AFOREMENTIONED TROUGH THEN TRANSLATES EASTWARD THROUGH THE EASTERN GREAT LAKES WEDNESDAY NIGHT...SOME WEAK LIFT AHEAD OF THE THIS SYSTEM WILL RESULT IN SOME SNOW SHOWERS DEVELOPING. BEST CHANCE FOR ANY MEASURABLE SNOWFALL WILL BE FOR AREAS NORTH OF THE CAPITAL REGION...WHERE S/SW FLOW WILL ALLOW FOR UPSLOPE FLOW NEAR THE FOOTHILLS OF THE SOUTHERN ADIRONDACKS. ANY ACCUMULATIONS WILL BE VERY MINOR AND FOR NOW WILL ONLY MENTION CHANCE POPS. ANOTHER COLD NIGHT IN STORE...ALTHOUGH A FEW DEGREES "WARMER" DUE TO A DEVELOPING SOUTHERLY WIND AT THE SURFACE. ON THURSDAY LOW PRESSURE IS EXPECTED TO DEEPEN OVER SOUTHERN QUEBEC IN RESPONSE TO A POTENT UPPER LOW MOVING ACROSS THE UPPER GREAT LAKES AND SOUTHEAST ONTARIO. AS THIS SYSTEM TRACKS EAST...ANOTHER SHOT OF DEEP COLD AIR WILL FILTER INTO THE REGION...SHIFTING THE FLOW TO MORE OF A WESTERLY DIRECTION. WITH LAKE ONTARIO WATER TEMPS REMAINING RELATIVELY WARM...THIS WILL ALLOW FOR LAKE EFFECT SNOW TO DEVELOP DOWNWIND OF THE LAKE AND POTENTIALLY IMPACT THE WESTERN ADIRONDACKS DURING THE DAY THURSDAY. WILL MENTION THIS POTENTIAL IN THE HWO FOR NORTHERN HERKIMER AND HAMILTON COUNTIES. AS THE FLOW BECOMES WNW THURSDAY NIGHT...LAKE EFFECT SNOW MAY IMPACT PORTIONS OF CENTRAL/SOUTHERN HERKIMER COUNTY AND EVEN THE MOHAWK VALLEY BUT THIS IS HIGHLY UNCERTAIN AT THIS TIME. OUTSIDE OF LAKE EFFECT...ONCE AGAIN BLUSTERY AND COLD CONDITIONS ARE EXPECTED WITH TEMPERATURES CONTINUING TO RUN WELL BELOW NORMAL FOR MID TO LATE NOVEMBER. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MODERATING TEMPS IN THE LONG TERM WITH SOME INCLEMENT WEATHER TO CLOSE THE WEEKEND AND OPEN NEXT WEEK. FRIDAY-FRIDAY NIGHT...THE LAST REMNANTS OF LAKE EFFECT SNOW WILL IMPACT LOCATIONS WEST OF THE HUDSON VALLEY DURING THE DAY. THE UPPER LEVEL TROUGH AXIS SWINGS ACROSS THE REGION WITH SFC HIGH PRESSURE BUILDING IN FROM THE OHIO VALLEY AND MID ATLANTIC REGION. THE LOW AND MID LEVEL FLOW WILL BECOME ANTICYCLONIC WITH A LOWERING SUBSIDENCE INVERSION. H850 TEMPS WILL STILL BE BELOW NORMAL IN THE -13C TO -15C RANGE. HIGHS WILL ONLY BE IN THE 20S TO L30S WITH LOWS IN THE TEENS AND LOWER 20S WITH SOME SINGLE DIGITS IN THE SRN DACKS. SATURDAY-SATURDAY NIGHT...A QUIET START TO THE WEEKEND WITH HIGH PRESSURE BUILDING IN FROM THE SOUTH. A WARM FRONT WILL LIFT WELL NORTH AND WEST OF THE REGION. MID AND HIGH CLOUDS WILL INCREASE LATE IN THE DAY. SOME THERMAL ADVECTION SNOW SHOWERS WILL MOVE IN DURING THE NIGHT TIME PERIOD. HIGHS WILL STILL RUN BELOW NORMAL BY 10 DEGREES WITH MILDER MINS IN THE WARM ADVECTION REGIME. SUNDAY INTO MONDAY...A STORM SYSTEM APPROACHES FROM THE CNTRL MS RIVER VALLEY. THERE ARE SOME TIMING DIFFERENCES BETWEEN THE ECMWF...CAN GGEM...GFS...AND GEFS. AS THE WAVE LIFTS N/NE INTO THE GREAT LAKES REGION...STRONG ISENTROPIC LIFT WILL INCREASE AHEAD OF THE WARM FRONT. THE STRONG QG LIFT GENERATED BY THE DIFFERENTIAL THICKNESS ADVECTION WILL PROMOTE PERIODS OF SHOWERS LATE SUNDAY INTO MONDAY. TEMPS SOAR BACK ABOVE NORMAL WITH HIGHS REBOUNDING FROM THE U30S TO L50S ON SUNDAY...TO POTENTIALLY WIDESPREAD 50S TO L60S ON MONDAY...AS THE CYCLONE PASSES WELL WEST OF THE REGION INTO THE SE ONTARIO AND QUEBEC. THE HIGHEST POPS WERE PLACED IN THE FORECAST SUNDAY NIGHT INTO MONDAY WITH LIKELY AND HIGH CHC VALUES. MONDAY NIGHT INTO TUESDAY...A POSITIVELY TILTED LONGWAVE TROUGH AXIS REMAINS UPSTREAM...AND THE COLD FRONT TO THE SYSTEM GRADUALLY MOVES THROUGH ON TUESDAY. MORE CHANCES OF SHOWERS CONTINUE WITH TEMPS GRADUALLY LOWERING TO NORMAL TO BELOW NORMAL READINGS FOR LATE NOVEMBER. OVERALL...TEMPS COULD AVERAGE NEAR NORMAL IN THE LONG TERM DUE TO THE LATE WEEKEND/EARLY WEEK WARM UP AND PCPN ABOVE NORMAL. && .AVIATION /23Z TUESDAY THROUGH SUNDAY/... VFR CONDITIONS ARE EXPECTED THE NEXT 24 HOURS...AS A W TO NW FLOW ALOFT WILL DOMINATE WITH A STRONG UPPER LEVEL TROUGH OVER THE ERN CONUS. SCATTERED STRATOCUMULUS WILL OCCUR THIS EVENING WITH BRISK SW TO W WINDS OF 10 TO 15 KT WITH SOME GUSTS 20 TO 25 KT DIMINISHING THIS EVENING TO AROUND 10 KT. THE SKIES WILL CLEAR TONIGHT...AND THE WINDS WILL INCREASE SLIGHTLY AT 10-15 KTS AS NIGHTTIME SUBSIDENCE HELPS MIX SOME WINDS TO THE SURFACE. A FEW GUSTS IN THE 20-25 KT RANGE ARE POSSIBLE AT KALB AND KPSF. THE WINDS WILL CONTINUE TO BACK TO S TO SW AHEAD OF THE NEXT DISTURBANCE LATE TOMORROW MORNING AND INTO THE AFTERNOON. SOME MID AND HIGH CLOUDS WILL ALSO INCREASE TOWARDS NOONTIME. WINDS SHOULD EASE TO LESS THAN 10 KT AFTER 21Z. OUTLOOK... WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. THURSDAY: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: LOW OPERATIONAL IMPACT. BREEZY. CHANCE OF SHSN. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. && .HYDROLOGY... NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED THROUGH AT LEAST THE NEXT FIVE DAYS. MAINLY DRY CONDITIONS ARE EXPECTED ACROSS THE HSA...EXCEPT FOR LAKE EFFECT SNOW TONIGHT INTO WEDNESDAY ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. ADDITIONAL LIGHT SNOW SHOWERS ARE POSSIBLE WEDNESDAY NIGHT INTO THURSDAY...WITH MORE LAKE EFFECT SNOW ON THURSDAY FOR FAVORED AREAS. TEMPERATURES WILL BE BELOW FREEZING FOR MUCH OF THE PERIOD...SO ICE FORMATION IS EXPECTED ON SOME BODIES OF WATER AND ESPECIALLY SHALLOWER LAKES...PONDS AND STREAMS. 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...LAKE EFFECT SNOW WARNING UNTIL NOON EST WEDNESDAY FOR NYZ032. LAKE EFFECT SNOW ADVISORY UNTIL NOON EST WEDNESDAY FOR NYZ033. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...NAS/JPV SHORT TERM...JPV LONG TERM...WASULA AVIATION...NAS HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS TAUNTON MA
348 AM EST MON NOV 17 2014 .SYNOPSIS... LOW PRESSURE WILL INTENSIFY AS IT PASSES OVER SOUTHERN NEW ENGLAND LATER TODAY...BRINGING RAIN TO THE REGION AND POSSIBLY DAMAGING WINDS TO SOUTHEAST NEW ENGLAND. MAINLY DRY BUT UNSEASONABLY COLD AND BLUSTERY WEATHER IS EXPECTED TUESDAY THROUGH THE REST OF THIS WEEK. THERE IS JUST THE RISK FOR A FEW FLURRIES/LIGHT SNOW SHOWERS WEDNESDAY NIGHT. APPEARS A SIGNIFICANT WARMUP IS IN STORE FOR EARLY NEXT WEEK WITH A HIGH LIKELIHOOD IN ABOVE NORMAL TEMPERATURES. && .NEAR TERM /THROUGH TODAY/... 350 AM UPDATE... PRECIPITATION SHIELD CONTINUES TO SPREAD N EARLY THIS MORNING... VERY MUCH IN LINE WITH 13KM RAP TIMING. SEEING SEVERAL REPORTS OF SNOW AND SLEET ON ITS LEADING EDGE DUE TO INITIAL WET BULB COOLING AND LOW LEVEL NORTHERLY AGEOSTROPHIC FLOW...BUT RAP SHOWS FAIRLY QUICK WARMING TAKING PLACE THROUGH DAYBREAK WHICH WILL RESULT IN CHANGE TO RAIN ACROSS MOST OF AREA. EXCEPTION IS ACROSS HIGHER TERRAIN OF W MA AND SW NH WHICH WILL TAKE A BIT LONGER... SO WE WILL KEEP THE WINTER WEATHER ADVISORY POSTED. NOT LOOKING FOR MUCH IN WAY OF SNOW OR ICE ACCUMULATION...BUT ENOUGH TO RESULT IN SLIPPERY TRAVEL ESPECIALLY FOR THE FIRST PART OF THE MORNING COMMUTE. TEMPERATURES WILL BOTTOM OUT ACROSS INTERIOR THROUGH DAYBREAK DUE TO WET BULB COOLING...BUT SHOULD REMAIN STEADY OR BEGIN TO RISE SLOWLY CLOSER TO COAST AS SOUTHERLY FLOW GETS UNDERWAY. MADE A FEW MINOR ADJUSTMENTS TO FORECAST BASED UPON 00Z MODELS WHICH ARE OUTLINED BELOW. MAIN CONCERN NOW REVOLVES AROUND DAMAGING WINDS AND HEAVY RAINFALL LATER TODAY AND THIS EVENING. * STRONG/DAMAGING WINDS... EXPANDED HIGH WIND WARNING TO INCLUDE MA S COAST AS WELL AS EASTERN PLYMOUTH COUNTY. NAM/GFS SHOW AXIS OF LOW LEVEL JET PASSING OVER CAPE COD AND ISLANDS CENTERED AROUND 00Z TUE. THESE LOCATIONS ARE CLOSE ENOUGH IN WARM SECTOR TO INCREASE POTENTIAL FOR 50-60KT WIND GUSTS ACROSS THESE AREAS IN ADDITION TO CAPE COD...MARTHAS VINEYARD AND NANTUCKET. IN ADDITION...HIGH RES MODELS SHOW STRONG POTENTIAL FOR LINE OF CONVECTION EARLY THIS EVENING WHICH COULD PRODUCE DAMAGING WINDS AS WELL. WIND ADVISORY WAS ALSO EXPANDED TO INCLUDE NW RI AND EASTERN MA FROM METRO BOSTON TO CAPE ANN. THESE LOCATIONS SHOULD ALSO GET INTO WARM SECTOR LATER THIS AFTERNOON WHICH WILL INCREASE POTENTIAL FOR STRONG WIND GUSTS /40-45KT/. * HEAVY RAINFALL... WIDESPREAD 1 TO 2 INCHES OF RAIN IS EXPECTED ACROSS SOUTHERN NEW ENGLAND...BUT HIGH-RES MODELS CONTINUE TO SHOW AXIS OF 2 TO 3 INCHES OF RAIN ACROSS RI AND SE MA WHICH MAY BE ASSOCIATED WITH LINE OF CONVECTION EARLY THIS EVENING. THIS IS NOT EXPECTED TO PRODUCE WIDESPREAD FLOODING...BUT COULD RESULT IN MINOR FLOODING OF TYPICAL POOR DRAINAGE AREAS. CERTAINLY NEED TO KEEP AN EYE ON ANY CONVECTIVE DEVELOPMENT AS THAT WOULD SIGNIFICANTLY INCREASE POTENTIAL FOR FLOODING. FOR NOW CONFIDENCE IS NOT OVERLY HIGH IN THAT OCCURRING. HIGHS TODAY WILL RANGE FROM 40S ACROSS INTERIOR WHERE COOLER AIR WILL BE LOCKED IN...WHILE LOCATIONS CLOSER TO COAST RISE INTO 50S AND LOWER 60S LATE IN DAY. BLENDED NAM 2M TEMPERATURES TO MOS GUIDANCE WHICH LOOKED A BIT TOO COOL. && .SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/... 350 AM UPDATE... RAIN ENDS QUICKLY FROM W TO E AS LOW PRESSURE DEPARTS SOUTHERN NEW ENGLAND. DRYING SETS IN RAPIDLY OVERNIGHT WITH CLEARING SKIES EXPECTED. TEMPERATURES ACROSS INTERIOR WILL DROP INTO THE 20S AND LOWER 30S...WHICH COULD CAUSE SOME FREEZING OF LEFTOVER STANDING WATER...BUT THERE SHOULD BE ENOUGH MIXING TO ALLOW W WINDS TO DRY THINGS OUT. NOT AN ISSUE CLOSER TO COAST WHERE LOWS WILL REMAIN ABOVE FREEZING. COLDER AIR ARRIVES TUE ON BRISK W WINDS. THIS WILL MAINTAIN SOME CLOUDINESS ACROSS W NEW ENGLAND WITH MORE SUNSHINE DUE TO DOWNSLOPE WINDS CLOSER TO COAST...ALTHOUGH CLOUD STREETS SHOULD ALSO FORM OFF COAST DUE TO COLDER AIR PASSING OVER MILDER OCEAN SURFACE. HIGHS WILL TOP OUT IN 30S INTERIOR TO LOWER 40S NEAR COAST. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... 350 AM UPDATE HIGHLIGHTS... * DRY BUT UNSEASONABLY COLD TUE NIGHT INTO WED * A FEW FLURRIES/LIGHT SNOW SHOWERS POSSIBLE WED NIGHT * TEMPS TURN A BIT MILDER ON THU...BUT STILL BELOW NORMAL * ANOTHER SHOT OF UNSEASONABLY COLD WEATHER FRI INTO SAT * SIGNIFICANT WARMUP EARLY NEXT WEEK DETAILS... TUESDAY NIGHT AND WEDNESDAY... ANOMALOUS UPPER LEVEL RIDGING INTO WESTERN NORTH AMERICA AND ALASKA WILL FORCE THE POLAR JET SOUTH INTO THE EASTERN U.S. THIS WILL RESULT IN MAINLY DRY...BUT UNSEASONABLY COLD/BLUSTERY WEATHER. DESPITE WINDS NOT DECOUPLING TUE NIGHT...LOW TEMPS SHOULD BOTTOM OUT IN THE UPPER TEENS TO MIDDLE 20S FOR MOST UNDER STRONG COLD ADVECTION. WIND CHILL VALUES WILL BE DOWN IN THE SINGLE DIGITS ACROSS THE INTERIOR AND 10 TO 15 DEGREES ALONG THE COASTAL PLAIN BY DAYBREAK WED! DESPITE PARTIAL SUNSHINE ON WED...850 MB TEMPS AROUND -14C WILL RESULT IN HIGH TEMPS 15 TO 20 DEGREES BELOW NORMAL. HIGH TEMPS SHOULD ONLY RECOVER TO AROUND 30 ACROSS THE HIGHER TERRAIN AND MIDDLE 30S ON THE COASTAL PLAIN. WIND GUSTS OF 25 TO 35 MPH WILL MAKE IT FEEL EVEN COLDER...CERTAINLY MORE LIKE JANUARY THAN NOVEMBER. WEDNESDAY NIGHT AND THURSDAY... MID LEVEL WARM ADVECTION WILL DEVELOP AHEAD OF THE NEXT COLD FRONT. GIVE THE COLD DOME IN PLACE...COULD SEE A BRIEF PERIOD OF FLURRIES/LIGHT SNOW SHOWERS WED NIGHT AS THIS WARMER AIR OVER RUNS IT. BOUNDARY LAYER SHOULD BE COLD ENOUGH FOR MAINLY LIGHT SNOW SHOWERS/FLURRIES...EXCEPT PERHAPS ACROSS FAR SOUTHEAST NEW ENGLAND COAST. CERTAINLY DO NOT EXPECT MUCH SNOW...BUT A FEW NEIGHBORHOODS COULD RECEIVE A COATING. ANY OF THIS ACTIVITY SHOULD EXIT THE REGION BY MID MORNING ON THU. OTHERWISE...SHOULD SEE PARTIAL SUNSHINE DEVELOP BY THU AFTERNOON. HIGHS WILL BE MILDER THAN TUE AND WED...RECOVERING TO THE UPPER 30S ACROSS THE HIGHER TERRAIN TO THE LOWER TO MIDDLE 40S ON THE COASTAL PLAIN. FRIDAY AND SATURDAY... UNSEASONABLY COLD AIR WORKS BACK INTO THE REGION FRI INTO SAT BEHIND THE COLD FRONT. HIGH TEMPS SHOULD MAINLY BE IN THE 30S...TO THE LOWER 40S ON FRI. SAT LOOKS VERY COLD WITH HIGHS NOT GETTING OUT OF THE 30S. IN FACT...IF THE ECMWF IS RIGHT HIGH TEMPS MAY NOT BREAK FREEZING ALONG THE COASTAL PLAIN! NOT SURE IF IT WILL BE THAT EXTREME...BUT THIS SHOT OF COLD AIR ALSO LOOKS VERY IMPRESSIVE. SUNDAY AND MONDAY... HIGH PRESSURE MOVES OFF THE COAST ON SUNDAY ALLOWING A SOUTHWEST FLOW OF MILDER AIR TO WORK INTO THE REGION. HIGHS SHOULD RECOVER WELL INTO THE 40S...TO PERHAPS NEAR 50 ALONG THE FAR SOUTHEAST NEW ENGLAND COAST. MOST OF THE DAY SHOULD BE DRY...BUT CHANCES FOR SHOWERS WILL INCREASE SUN NIGHT AND MON AS LOW PRESSURE PASSES TO OUR NORTHWEST ALLOWING LOW LEVEL MOISTURE TO STREAM NORTHWARD. THIS SHOULD RESULT IN WELL ABOVE NORMAL TEMPS BY NEXT MON...SO BIG CHANGES ARE EXPECTED BY EARLY NEXT WEEK. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. 350 AM UPDATE...MODERATE CONFIDENCE. MVFR CIGS NEAR S COAST SLOWLY EXPAND INLAND EARLY THIS MORNING WITH MOST SITES LOWERING TO MVFR BY 12Z AS RAIN SPREADS INTO SOUTHERN NEW ENGLAND. MAIN AREA OF -FZRA/-SN/-PL CONTINUES TO BE ON NORTHERN EDGE OF PRECIPITATION SHIELD ACROSS W MA AND SW NH...BUT THESE AREAS WILL TRANSITION TO RAIN DURING MORNING. CONDITIONS LOWER FURTHER TO IFR BY EARLY AFTERNOON IN RAIN AND FOG. INCREASING LOW LEVEL JET /75KT AT 3KFT/ WILL BRING LLWS TO MUCH OF RI AND SE MA DURING AFTERNOON AND EVENING. SURFACE WIND GUSTS 50-60KT POSSIBLE AROUND CAPE COD AND ISLANDS AND TO 45KT ACROSS RI AND EASTERN MA. LIGHTER SURFACE WINDS FARTHER INLAND BUT LLWS STILL A CONCERN WITH 40-45KT AT 3KFT. POTENTIAL FOR EMBEDDED TSTMS S OF I-90 LATE THIS AFTERNOON AND EARLY THIS EVENING...OR EVEN NARROW LINE OF TSTMS...BUT NOT INCLUDED IN TAFS DUE TO LOW PROBABILITY. CONDITIONS IMPROVE RAPIDLY TO VFR FROM W TO E BETWEEN 03Z AND 08Z TUE AS WINDS SHIFT TO W. VFR TUE WITH W WINDS GUSTING TO 30KT. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. CONDITIONS MAY LOWER A BIT FASTER THAN INDICATED THIS MORNING. MORE CONFIDENT ON WIND TRENDS. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. SOME UNCERTAINTY AS TO HOW QUICKLY CONDITIONS LOWER THIS MORNING. PRECIPITATION TYPE ALL RAIN. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... HIGH CONFIDENCE IN MAINLY VFR CONDITIONS OVER THIS TIME PERIOD. HOWEVER...BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE FROM TIME TO TIME. THE BEST SHOT FOR THIS IS WED NIGHT IN A FEW LIGHT SNOW SHOWERS/FLURRIES. WEST TO SOUTHWEST WINDS WILL GUST AT TIMES BETWEEN 20 AND 30 KNOTS THROUGH THU AND FROM THE WEST NORTHWEST ON FRI. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. * DANGEROUS CONDITIONS THIS AFTERNOON AND TONIGHT * 350 AM UPDATE...MODERATE CONFIDENCE. EXPANDED STORM WARNINGS TO INCLUDE MORE OF S COASTAL BAYS AND SOUNDS. ONSET OF GALES IS AROUND MIDDAY ON SOUTHERN WATERS AND EARLY THIS AFTERNOON ON EASTERN WATERS...WITH STRONGEST WINDS CENTERED FEW HOURS AROUND 7 PM TONIGHT. PERIODS OF RAIN EXPECTED TODAY BUT THERE IS ALSO POSSIBILITY OF EMBEDDED THUNDERSTORMS...OR A NARROW LINE OF STORMS...LATER THIS AFTERNOON AND THIS EVENING. IN RESPONSE TO INCREASING WINDS...SEAS WILL BUILD RAPIDLY THIS AFTERNOON WITH 12 FT SEAS ON OUTER WATERS THIS EVENING. WINDS SHIFT TO W LATER TONIGHT AS LOW PRESSURE EXITS REGION. WINDS WILL GRADUALLY DIMINISH BUT REMAIN GUSTY...AT LEAST 25-30KT...AND SEAS WILL REMAIN ROUGH. BRISK W WINDS GUSTING TO 30-35KT EXPECTED TUE AS HIGH PRESSURE BUILDS INTO NEW ENGLAND. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... TUESDAY NIGHT AND WEDNESDAY...HIGH CONFIDENCE. STRONG COLD ADVECTION OVER THE RELATIVELY MILD OCEAN WILL RESULT IN GALE FORCE WEST TO SOUTHWEST WIND GUSTS TUE NIGHT INTO WED MORNING OVER THE OPEN WATERS. WINDS PROBABLY DROP BACK TO SMALL CRAFT ADVISORY THRESHOLDS WED AFTERNOON AS PRESSURE GRADIENT WEAKENS A BIT. SEAS 6 TO 10 FEET ACROSS THE OUTER-WATERS WILL GRADUALLY DIMINISH WED AFTERNOON. WEDNESDAY NIGHT AND THURSDAY...MODERATE TO HIGH CONFIDENCE. WARM ADVECTION DEVELOPS AHEAD OF THE NEXT COLD FRONT. HOWEVER...THE AIRMASS WILL STILL BE COLDER THAN THE RELATIVELY MILD OCEAN AND SUPPORT GOOD MIXING. THEREFORE...EXPECT STRONG SCA TO GALE FORCE WIND GUSTS OVER THE OPEN WATERS. STRONGEST WINDS EXPECTED OVER THE SOUTHERN WATERS WITH SEAS BUILDING BACK BETWEEN 6 AND 10 FEET IN THIS REGION. FRIDAY...MODERATE TO HIGH CONFIDENCE. STRONG SMALL CRAFT TO GALE FORCE WEST TO NORTHWEST WIND GUSTS EXPECTED IN THE COLD AIR ADVECTION PATTERN BEHIND THE NEXT COLD FRONT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MAZ002>004-008>010-026. WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 PM EST THIS EVENING FOR MAZ007-013>018. HIGH WIND WARNING FROM 3 PM THIS AFTERNOON TO 11 PM EST THIS EVENING FOR MAZ019>024. NH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR NHZ011-012-015. RI...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 PM EST THIS EVENING FOR RIZ001>008. MARINE...STORM WARNING FROM 3 PM THIS AFTERNOON TO 1 AM EST TUESDAY FOR ANZ231>235. GALE WARNING FROM 5 PM THIS AFTERNOON TO 1 AM EST TUESDAY FOR ANZ230-236. GALE WARNING FROM NOON TODAY TO 1 AM EST TUESDAY FOR ANZ237- 251. GALE WARNING FROM NOON TODAY TO 5 AM EST TUESDAY FOR ANZ250- 256. STORM WARNING FROM 3 PM THIS AFTERNOON TO 3 AM EST TUESDAY FOR ANZ254-255. && $$ SYNOPSIS...FRANK/JWD NEAR TERM...JWD SHORT TERM...JWD LONG TERM...FRANK AVIATION...FRANK/JWD MARINE...FRANK/JWD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1006 AM EST MON NOV 17 2014 .DISCUSSION... ...SHOWERS/THUNDERSTORMS LIKELY LATE THIS AFTERNOON/EVENING... ...MUCH COLDER TUESDAY AND TUESDAY NIGHT... ...HAZARDOUS MARINE CONDITIONS TUESDAY-WEDNESDAY... .UPDATE... WARM SUMMERLIKE TEMPERATURES ARE EXPECTED OVER THE FORECAST AREA TODAY OUT AHEAD OF A STRONG COLD FRONT. WINDS IN THE 950-700MB LAYER BOTH STRENGTHENED AND VEERED OVERNIGHT (SOUTH SOUTHWEST 25 - 30 KNOTS) AND WILL CONTINUE TO DO SO THROUGH THE AFTERNOON AS THE COLD FRONT NEARS. THE MORNING XMR SOUNDING STILL SHOWS A SIGNIFICANT POCKET OF DRY AIR ABOVE 800MB...THOUGH THERE EXISTS PLENTY OF LOW LEVEL MOISTURE THAT IS CONTRIBUTING TO A PWAT OF AROUND 1.5". AS WINDS CONTINUE TO VEER THROUGH THE DAY AND DRAW IN MOISTURE FROM THE SOUTH AND WEST...EXPECT THE COLUMN TO MOISTEN FURTHER TO AROUND 2.0" BY THIS EVENING. AMPLE SUNSHINE SHOULD ALLOW TEMPERATURES TO WARM INTO THE MID AND UPPER 80S...THREATENING A FEW RECORD HIGHS ACROSS THE AREA (SEE CLIMATE SECTION BELOW). EXPECT BREEZY CONDITIONS LATE THIS MORNING AND EARLY THIS AFTERNOON AS MIXING BRINGS DOWN SOME OF THE STRONGER WINDS ALOFT. MUCH OF THE AREA SHOULD REMAIN DRY THROUGH EARLY THIS AFTERNOON AS THE ATMOSPHERE REMAINS RELATIVELY MOISTURE STARVED. A FEW STORMS SHOULD DEVELOP OUT WELL AHEAD OF THE FRONT AS DAYTIME HEATING AND INCREASED MOISTURE CONTINUE INTO THE MID AND LATER AFTERNOON. EXPECT THE MAIN EVENT AROUND AND AFTER SUNSET AS BETTER FORCING APPROACHES FROM THE WEST IN ASSOCIATION WITH THE FRONT. STRONG SOUTHWEST WINDS JUST ABOVE THE SURFACE THROUGH 500MB WILL CONTRIBUTE TO A GUSTY WIND POTENTIAL IN TODAYS STORMS. FLOW REMAINS FAIRLY UNIDIRECTIONAL...THUS TORNADO POTENTIAL APPEARS MINIMAL AT THIS TIME. LOCAL MODELLING AND HIGH-RES HRRR MODEL POINTS TO A BROKEN LINE OF SHOWERS AND STORMS APPROACHING OUR NORTHWESTERN ZONES...LAKE/VOLUSIA COUNTY...AROUND AND JUST AFTER SUNSET. ALL AVAILABLE GUIDANCE INDICATES A GRADUAL WEAKENING TREND IN THE CONVECTION AS IT MOVES THROUGH OUR CWA. THIS LINES UP WELL WITH MESOSCALE ANALYSES THAT POINT TO BETTER DYNAMICS THE FURTHER NORTH YOU GO OVER THE PENINSULA. EXPECT BROKEN LINE OF SHOWERS AND STORMS TO MOVE THROUGH THE SPACE AND TREASURE COASTS LATE THIS EVENING AND OVERNIGHT TONIGHT. FRONT WILL GRADUALLY WORK ITS WAY DOWN THE PENINSULA TONIGHT...APPROACHING LAKE AND VOLUSIA COUNTY WELL AFTER SUNSET AND BEHIND MOST OF THE CONVECTION. BREEZY NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN THE COLDEST AIR MASS OF THE SEASON FOR TOMORROW. MORE ON THAT IN THIS AFTERNOONS PACKAGE. && .AVIATION... INCREASING SOUTH TO SOUTHWEST FLOW TODAY AT ALL TERMINALS. LOW CLOUDS/STRATUS THIS MORNING SHOULD MIX OUT AS DAYTIME HEATING CONTINUES...LIFTING CURRENT MVFR/IFR CIGS TO VFR. ISOLATED SHRA AND PERHAPS A TSRA COULD DEVELOP THIS AFTERNOON OUT AHEAD OF A BROKEN LINE OF SHRA AND TSRA THAT WILL APPROACH OUR NORTHWESTERN TERMINALS (LEE AND DAB) AROUND AND AFTER SUNSET. EXPECT LINE OF CONVECTION TO MOVE THROUGH AS EVENING PROGRESSES. GUSTY WNW/NW WINDS EXPECTED BEHIND FRONTAL BOUNDARY AS IT MOVES THROUGH TONIGHT. && .MARINE...TODAY-TONIGHT...A STRONG COLD FRONT WILL PASS OVER THE COASTAL WATERS OVERNIGHT TONIGHT. SHOWER CHANCES WILL INCREASE FROM NORTH TO SOUTH INTO THE AFTERNOON WITH LIGHTNING STORM CHANCES INCREASING LATE TODAY/TONIGHT. ACTIVITY LATER TODAY WILL MOVE QUICKLY OFFSHORE WITH CLOUD TO WATER LIGHTNING...HEAVY RAINFALL AND GUSTY WINDS IN EXCESS OF 35 KTS POSSIBLE. SSE WINDS VEER TO SSW THIS MORNING AND EARLY AFTERNOON AHEAD OF THE FRONT...THEN GRADUALLY TOWARD THE W/NW BEHIND IT OVERNIGHT. WIND SPEEDS GENERALLY 10-15 KTS AND GUSTY NEAR SHORE AND 15-20 KTS AND GUSTY OFFSHORE/NORTH OF SEBASTIAN INLET INTO THIS EVENING. NORTHWEST WINDS SPREADING SOUTHWARD BEHIND THE FRONT LATE TONIGHT WILL INCREASE TO 20-25 KTS AND GUSTY. A SMALL CRAFT ADVISORY WILL GO INTO EFFECT FOR THE OFFSHORE WATERS NORTH OF SEBASTIAN INLET AND NEAR SHORE NORTH LEG AT 00Z AND SPREAD AREAWIDE AT 06Z. SEAS GENERALLY 3-5 FT BUT WILL APPROACH 6 FT WELL OFFSHORE NORTH OF SEBASTIAN INLET. TONIGHT...SEAS WILL BUILD NEAR SHORE 4-6 FT LATE OVERNIGHT NORTH OF THE CAPE AND UP TO 7 FT (LATE) NORTH OFFSHORE LEG. && .CLIMATE...HIGH TEMPERATURES ARE FORECAST NEAR RECORD LEVELS AT VERO BEACH TODAY. RECORD HIGHS FOR TODAY 17 NOV: DAB 88 IN 1988. MCO 89 IN 1957. MLB 88 IN 1948. VRB 86 IN 2011. && .PRELIMINARY POINT TEMPS/POPS... DAB 84 48 60 38 / 60 80 20 10 MCO 83 55 60 39 / 60 80 20 10 MLB 86 59 63 43 / 50 80 40 10 VRB 86 64 66 49 / 60 80 50 10 LEE 82 48 57 34 / 70 80 10 10 SFB 83 53 60 38 / 60 80 20 10 ORL 83 52 60 40 / 60 80 20 10 FPR 86 64 66 50 / 60 70 50 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 PM EST TUESDAY FOR COASTAL WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM. SMALL CRAFT ADVISORY FROM 1 AM TUESDAY TO 10 AM EST WEDNESDAY FOR COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20 NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET OUT 20 NM-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE. SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST WEDNESDAY FOR WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE. && $$ IMPACT WEATHER/RADAR...MOSES AVIATION/FORECAST...ULRICH
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1251 PM EST MON NOV 17 2014 .SYNOPSIS... A WARM FRONT WILL CONTINUE TO LIFT NORTH OF AREA LATE THIS MORNING... FOLLOWED BY THE PASSAGE OF A STRONG COLD FRONT FROM THE WEST LATE TODAY AND EARLY THIS EVENING. COLD ARCTIC HIGH PRESSURE WILL THEN BUILD OVER THE AREA INTO THE MIDDLE OF THE WEEK...THEN PREVAIL INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... THE PRIMARY CONCERN IS THE POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AS A POTENT COLD FRONT PUSHES THROUGH LATE IN THE DAY. A TORNADO WATCH IS IN EFFECT UNTIL 6 PM FOR ALL OF SOUTHEAST SC AND SOUTHEAST GA. A VERY WARM...MOIST AND MODERATELY UNSTABLE ENVIRONMENT HAS DEVELOPED ACROSS THE AREA IN WAKE OF A WARM FRONT THAT LIFTED THROUGH EARLIER THIS MORNING. DESPITE EXTENSIVE CLOUD COVER...TEMPERATURES HAVE ALREADY WARMED INTO THE MID AND UPPER 70S ALONG THE COASTAL CORRIDOR OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA...AND COULD BRIEFLY CLIMB INTO THE LOWER 80S IN SOME PLACES IN NORTH COASTAL GEORGIA EARLY THIS AFTERNOON WITH COMPRESSIONAL HEATING AND A STRONG SOUTH-SOUTHWEST FLOW AHEAD OF THE COLD FRONT. MEANWHILE DEW POINTS ACROSS THE AREA HAVE SURGED INTO THE UPPER 60S AND LOWER 70S. THE PRIMARY BAND OF CONVECTION AHEAD OF THE FRONT HAS ALREADY ENTERED WESTERN PORTIONS OF THE FORECAST AREA...AND WILL PROGRESS TOWARD THE I-95 CORRIDOR AROUND 2 PM...BEFORE PUSHING OFF THE SOUTH CAROLINA COAST AROUND 4 PM. THIS AREA OF CONVECTION WAS RESPONSIBLE FOR PRODUCING SEVERAL TORNADOES UPSTREAM ACROSS THE FL PANHANDLE AND SOUTHWEST GA. THE MODE OF CONVECTION HAS CLEARLY SHIFTED FROM THE DISCRETE SUPERCELLS SEEN EARLIER UPSTREAM...TO MORE LINEAR SEGMENTS DUE TO THE LOW LEVEL FLOW BECOMING MORE UNIDIRECTIONAL. WIND SHEAR WILL REMAIN IMPRESSIVE HOWEVER...WITH THE HRRR SOUNDINGS AT KSAV DEPICTING 0-1KM SHEAR VALUES OF 27 KT AND 0-3KM SHEAR VALUES OF 43 KT DUE TO A POTENT LOW LEVEL JET ALOFT. IN ORDER TO TAP INTO THESE WINDS HOWEVER...SUFFICIENT INSTABILITY IS NEEDED TO SUPPORT DEEP UPDRAFTS/DOWNDRAFTS...AND IT APPEARS THAT WE MAY ATTAIN CAPE VALUES UP AROUND 1000 J/KG THIS AFTERNOON BASED ON THE LATEST HIGH RESOLUTION MODEL SOUNDINGS. GIVEN THESE VALUES...IT APPEARS THE AREA IS PRIMED FOR A POTENTIAL HIGH SHEAR LOW CAPE SEVERE WEATHER EVENT...SUPPORTED BY SHERB VALUES OF 1.0 TO 1.2 ACROSS MUCH OF THE AREA. WHILE THE PRIMARY SEVERE WEATHER THREAT IS DAMAGING WINDS...THERE IS CERTAINLY THE POTENTIAL FOR AN ISOLATED TORNADO OR TWO TO OCCUR. THE HIGHEST SEVERE WEATHER PROBABILITIES WILL ALSO OCCUR ACROSS SOUTHEAST GEORGIA WHERE TEMPERATURES/INSTABILITY WILL BE GREATEST. THE COLD FRONT WILL BLAST THROUGH LATE TODAY AND EARLY THIS EVENING WITH CONVECTIVE RAINS SHIFTING QUICKLY OFF THE COAST SHORTLY AFTER SUNSET THEN COLD AIR WILL COME POURING IN ON THE HEELS OF STRONG PRES RISES. NEAR FREEZING TEMPS ARE LIKELY IN WESTERN GEORGIA AREAS AND BORDERING THE FAR SE MIDLANDS AND CSRA BUT WE HAVE HIGHLIGHTED THE BIG EVENT FOR WEDNESDAY MORNING WITH A FREEZE WATCH TO ALERT FOR SUB-FREEZING TEMPS ALL THE WAY TO THE OCEAN...A VERY RARE EVENT FOR MID NOVEMBER ON BEACHES AND BARRIER ISLANDS. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... TUESDAY AND TUESDAY NIGHT...STRONG COLD ADVECTION WILL BE ONGOING DURING TUESDAY IN THE WAKE OF THE ARCTIC FRONT. DOWNSLOPE WEST TO NORTHWEST WINDS WILL SOMEWHAT TEMPER THE IMPACT ON TEMPERATURES. EVEN SO...LOW LEVEL THICKNESS VALUES WITH FULL SUN SUPPORT HIGHS ONLY FROM THE UPPERS 40S IN THE NORTHWEST TO LOWER 50S IN THE EXTREME SOUTHEAST. MAINTAINED HIGHS FROM THE NEAR 50 IN MOST AREAS. THE STAGE IS SET FOR A WIDESPREAD HARD FREEZE FOR ALL AREAS TUESDAY NIGHT...WITH LIKELY RECORD BREAKING TEMPERATURES AT ALL THREE CLIMATE SITES. THIS WILL BE THE COLDEST IT HAS BEEN IN MANY AREAS SINCE JANUARY 25TH 2014. CLEAR SKIES AND VERY LOW DEWPOINTS COMBINED WITH DIMINISHING WINDS WILL SET THE STAGE FOR DECENT RADIATIONAL COOLING ACROSS INLAND AREAS. LATEST MODEL GUIDANCE SUGGEST LIGHT NORTH WINDS ALONG THE IMMEDIATE COAST WHICH SHOULD ALLOW SUB FREEZING TEMPERATURES TO REACH ALL BEACHES. LOOKS LIKE 10 TO 13 HOURS OF SUBFREEZING TEMPERATURES WILL OCCUR ACROSS FAR INLAND AREAS RANGING TO 2 TO 4 HOURS AT THE GEORGIA BEACHES. HAVE ISSUED A FREEZE WATCH FOR ALL AREAS FOR TUESDAY NIGHT. SINCE LOW TEMPERATURES ARE EXPECTED TO BE WELL BELOW FREEZING FOR MANY HOURS...PRECAUTIONS NEED TO BE TAKEN TO PROTECT EXPOSED PIPES. WEDNESDAY THROUGH THURSDAY...AFTER A FRIGID START ON WEDNESDAY MORNING...ABUNDANT SUNSHINE WILL HELP TEMPERATURES RECOVER TO NEAR 50 DEGREES IN MANY AREAS. WITH THE HIGH PRESSURE CENTERED NEAR THE AREA...WINDS WILL BE LIGHT...SO THERE WILL NOT BE ANY DOWNSLOPE FLOW TO HELP MODERATE TEMPERATURES MORE QUICKLY. A GOOD RADIATIONAL COOLING NIGHT IS EXPECTED WEDNESDAY NIGHT ACROSS THE AREA. HOWEVER...INCREASING LOW LEVEL THICKNESS VALUES AND HIGHER DEWPOINTS THAN TUESDAY NIGHT WILL KEEP TEMPERATURES FROM FALLING TO TUESDAY NIGHTS LEVELS. EXPECT FREEZING TEMPERATURES IN MOST AREAS...WITH LOWS IN THE MID TO UPPER 20S INLAND TO THE MID 30S NEAR THE COAST. IN ALL LIKELIHOOD FREEZING TEMPERATURES WILL OCCUR IN ALL AREAS TUESDAY NIGHT WHICH SHOULD EFFECTIVELY END THE GROWING SEASON. AS A RESULT...IT IS HIGHLY LIKELY THAT NO FREEZE WATCHES OR WARNINGS WILL BE ISSUED FOR WEDNESDAY NIGHT UNLESS FREEZING TEMPERATURES DO NOT OCCUR EVERYWHERE TUESDAY NIGHT. A MODERATING TREND BEGINS ON THURSDAY. ABUNDANT SUNSHINE AND INCREASING LOW LEVEL THICKNESS VALUES SUPPORT HIGH TEMPERATURES IN MOST AREA NEAR 60 DEGREES. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... DECENT CONFIDENCE IN A GENERAL MODERATING TREND DURING THIS PERIOD...WITH HIGH TEMPERATURES CLIMBING TO NEAR OR PERHAPS EVEN ABOVE NORMAL VALUES BY SUNDAY AND LIKELY TO ABOVE NORMAL LEVELS BY MONDAY. GOOD AGREEMENT BETWEEN ECMWF AND GFS THAT THE AREA WILL LIKELY REMAIN RAIN FREE THROUGH SATURDAY. MODEL DIFFERENCES BECOME QUITE PRONOUNCED BY SUNDAY AND MONDAY...BUT IT DOES APPEAR THAT THE WEATHER WILL GET MORE UNSETTLED THEN AND AT LEAST FOR NOW INCLUDED SLIGHT CHANCES FOR RAIN SHOWERS SUNDAY THROUGH MONDAY. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... A LINE OF SHOWERS AND THUNDERSTORMS AHEAD OF A COLD FRONT WILL AFFECT THE TERMINALS IN THE 19-21Z TIME FRAME. MODERATE TO HEAVY THUNDERSTORMS WILL RESULT IN FLIGHT RESTRICTIONS DUE TO REDUCED VISIBILITIES AND LOW CEILINGS. GUSTY AND ERRATIC WINDS ARE ALSO EXPECTED AS THE CONVECTION SHIFTS ACROSS THE TERMINALS. ONCE THE SHOWERS AND THUNDERSTORMS SHIFT OFFSHORE LATE THIS AFTERNOON...SKIES WILL BEGIN CLEARING BUT GUSTY WEST-NORTHWEST WINDS WILL CONTINUE INTO TUESDAY MORNING. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL. && .MARINE... OTHERWISE INCREASING LOW LEVEL JET AND WARM AIR ADVECTION BOTH IMPRESSIVE TODAY BUT THE MIXING PROFILES ARE QUITE POOR CLOSE TO SHORE AS SEA SURFACE TEMPS ARE CLOSER TO 60F. THE LAND/SEA INTERFACE SHOULD BECOME GUSTY BY EARLY AFTERNOON AND ALLOWED AN SCA TO CONTINUE NORTH OF SAVANNAH TODAY. THE TWO MOST SIGNIFICANT ISSUES WILL BE CONVECTION LATER TODAY AND POSSIBLE GALES OVER THE GEORGIA WATERS TONIGHT. THE CONVECTION WILL PRODUCE A RISK OF WIND GUSTS OVER 35 KT AND POSSIBLE WATERSPOUTS ESPECIALLY OVER WATERS SEAWARD FROM THE PILOT BUOYS. THE TIMING LOOKS TO BE MID AFTERNOON THROUGH EARLY EVENING. THE GALE RISK WAS HIGH ENOUGH THIS MORNING TO HOIST A GALE WATCH TONIGHT FOR THE OUTER GEORGIA WATERS. GRAYS REEF COULD SEE A PERIOD OF GALE FORCE GUSTS FROM LATE EVENING TO 6 AM AS JETTING AND LOW LEVEL MOMENTUM PROGS ARE EXTREMELY FAVORABLE GIVEN THE SHARP ISALLOBARIC RISES ANTICIPATED. OTHER WATERS WILL BE IN SMALL CRAFT ADVISORY CONDITIONS TONIGHT. TUESDAY THROUGH FRIDAY...HIGH PRESSURE WILL BUILD FROM THE WEST ON TUESDAY...WITH IMPROVING CONDITIONS ON THE WATERS. SMALL CRAFT ADVISORIES FOR AMZ352 AND AMZ354 ARE EXPECTED TO END TUESDAY MORNING. ANY GALE CONDITIONS ACROSS AMZ374 SHOULD END EARLY ON TUESDAY WITH SMALL CRAFT ADVISORY CONDITIONS THEN PERSISTING INTO TUESDAY NIGHT. IMPROVING CONDITIONS WILL THEN CONTINUE ACROSS ALL WATERS AS HIGH PRESSURE SETTLES OVER THE REGION. WINDS MAINLY AOB 10 KNOTS AND SEAS 1 TO 3 FEET ARE EXPECTED FROM WEDNESDAY MORNING INTO THURSDAY NIGHT AND POSSIBLY EVEN FRIDAY MORNING. && .CLIMATE... RECORD LOW MAXIMUM TEMPERATURES FOR NOVEMBER 18TH... KCHS...49 SET IN 2008. KCHL...48 SET IN 1951. KSAV...45 SET IN 1891. RECORD LOWS FOR NOVEMBER 19TH... KCHS...27 SET IN 1949. KCHL...31 SET IN 1903. KSAV...27 SET IN 2008 AND PREVIOUS. RECORD LOW MAXIMUM TEMPERATURES FOR NOVEMBER 19TH... KCHS...44 SET IN 2000. KCHL...45 SET IN 1951. KSAV...44 SET IN 2000. RECORD LOW FOR SO EARLY IN THE SEASON... KCHS...22 NOVEMBER 16 1940. KCHL...28 NOVEMBER 16 1940. KSAV...24 NOVEMBER 3 1954. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR GAZ087-088-099>101-114>119-137>141. SC...FREEZE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR SCZ040-042>045-047>052. LAKE WIND ADVISORY UNTIL 6 AM EST TUESDAY FOR SCZ045. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TUESDAY FOR AMZ352. SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ330-350. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO NOON EST TUESDAY FOR AMZ354. GALE WATCH FROM 7 PM EST THIS EVENING THROUGH TUESDAY MORNING FOR AMZ374. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ374. && $$ NEAR TERM...JAQ SHORT TERM...MTE LONG TERM...MTE AVIATION...JAQ/MTE MARINE...MTE CLIMATE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1135 AM EST MON NOV 17 2014 ...SEVERE WEATHER THREAT THIS AFTERNOON... .SYNOPSIS... A WARM FRONT WILL CONTINUE TO LIFT NORTH OF AREA LATE THIS MORNING... FOLLOWED BY THE PASSAGE OF A STRONG COLD FRONT FROM THE WEST LATE TODAY AND EARLY THIS EVENING. COLD ARCTIC HIGH PRESSURE WILL THEN BUILD OVER THE AREA INTO THE MIDDLE OF THE WEEK...THEN PREVAIL INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... THE PRIMARY CONCERN IS THE POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AS A POTENT COLD FRONT PUSHES THROUGH LATE IN THE DAY. A TORNADO WATCH IS IN EFFECT UNTIL 6 PM FOR ALL OF SOUTHEAST SC AND SOUTHEAST GA. A VERY WARM...MOIST AND MODERATELY UNSTABLE ENVIRONMENT HAS DEVELOPED ACROSS THE AREA IN WAKE OF A WARM FRONT THAT LIFTED THROUGH EARLIER THIS MORNING. DESPITE EXTENSIVE CLOUD COVER...TEMPERATURES HAVE ALREADY WARMED INTO THE MID AND UPPER 70S ALONG THE COASTAL CORRIDOR OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA...AND COULD CLIMB INTO THE LOWER 80S IN SOME PLACES IN NORTH COASTAL GEORGIA BY EARLY AFTERNOON WITH COMPRESSIONAL HEATING AND A STRONG SOUTH-SOUTHWEST FLOW AHEAD OF THE COLD FRONT. MEANWHILE DEW POINTS ACROSS THE AREA HAVE SURGED INTO THE UPPER 60S AND LOWER 70S. THE PRIMARY BAND OF CONVECTION AHEAD OF THE FRONT IS EXPECTED TO ENTER WESTERN PORTIONS OF THE FORECAST AREA AROUND NOON...THEN PROGRESS TOWARD THE I-95 CORRIDOR AROUND 2 PM...BEFORE PUSHING OFF THE SOUTH CAROLINA COAST AROUND 4 PM. THIS AREA OF CONVECTION WAS RESPONSIBLE FOR PRODUCING SEVERAL TORNADOES UPSTREAM ACROSS THE FL PANHANDLE AND SOUTHWEST GA. AS THE STORMS SHIFT INTO THE AREA...THE MODE OF CONVECTION WILL SHIFT FROM THE DISCRETE SUPERCELLS SEEN EARLIER UPSTREAM...TO MORE LINEAR SEGMENTS AS THE LOW LEVEL FLOW BECOMES MORE UNIDIRECTIONAL. WIND SHEAR WILL REMAIN IMPRESSIVE HOWEVER...WITH THE HRRR SOUNDINGS AT KSAV DEPICTING 0-1KM SHEAR VALUES OF 27 KT AND 0-3KM SHEAR VALUES OF 43 KT DUE TO A POTENT LOW LEVEL JET ALOFT. IN ORDER TO TAP INTO THESE WINDS HOWEVER...SUFFICIENT INSTABILITY IS NEEDED TO SUPPORT DEEP UPDRAFTS/DOWNDRAFTS...AND IT APPEARS THAT WE MAY ATTAIN CAPE VALUES UP AROUND 1000 J/KG THIS AFTERNOON BASED ON THE LATEST HIGH RESOLUTION MODEL SOUNDINGS. GIVEN THESE VALUES...IT APPEARS THE AREA IS PRIMED FOR A POTENTIAL HIGH SHEAR LOW CAPE SEVERE WEATHER EVENT...SUPPORTED BY SHERB VALUES OF 1.0 TO 1.2 ACROSS MUCH OF THE AREA. WHILE THE PRIMARY SEVERE WEATHER THREAT IS DAMAGING WINDS...THERE IS CERTAINLY THE POTENTIAL FOR AN ISOLATED TORNADO OR TWO TO OCCUR. THE HIGHEST SEVERE WEATHER PROBABILITIES WILL ALSO OCCUR ACROSS SOUTHEAST GEORGIA WHERE TEMPERATURES/INSTABILITY WILL BE GREATEST. THE COLD FRONT WILL BLAST THROUGH LATE TODAY AND EARLY THIS EVENING WITH CONVECTIVE RAINS SHIFTING QUICKLY OFF THE COAST SHORTLY AFTER SUNSET THEN COLD AIR WILL COME POURING IN ON THE HEELS OF STRONG PRES RISES. NEAR FREEZING TEMPS ARE LIKELY IN WESTERN GEORGIA AREAS AND BORDERING THE FAR SE MIDLANDS AND CSRA BUT WE HAVE HIGHLIGHTED THE BIG EVENT FOR WEDNESDAY MORNING WITH A FREEZE WATCH TO ALERT FOR SUB-FREEZING TEMPS ALL THE WAY TO THE OCEAN...A VERY RARE EVENT FOR MID NOVEMBER ON BEACHES AND BARRIER ISLANDS. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... TUESDAY AND TUESDAY NIGHT...STRONG COLD ADVECTION WILL BE ONGOING DURING TUESDAY IN THE WAKE OF THE ARCTIC FRONT. DOWNSLOPE WEST TO NORTHWEST WINDS WILL SOMEWHAT TEMPER THE IMPACT ON TEMPERATURES. EVEN SO...LOW LEVEL THICKNESS VALUES WITH FULL SUN SUPPORT HIGHS ONLY FROM THE UPPERS 40S IN THE NORTHWEST TO LOWER 50S IN THE EXTREME SOUTHEAST. MAINTAINED HIGHS FROM THE NEAR 50 IN MOST AREAS. THE STAGE IS SET FOR A WIDESPREAD HARD FREEZE FOR ALL AREAS TUESDAY NIGHT...WITH LIKELY RECORD BREAKING TEMPERATURES AT ALL THREE CLIMATE SITES. THIS WILL BE THE COLDEST IT HAS BEEN IN MANY AREAS SINCE JANUARY 25TH 2014. CLEAR SKIES AND VERY LOW DEWPOINTS COMBINED WITH DIMINISHING WINDS WILL SET THE STAGE FOR DECENT RADIATIONAL COOLING ACROSS INLAND AREAS. LATEST MODEL GUIDANCE SUGGEST LIGHT NORTH WINDS ALONG THE IMMEDIATE COAST WHICH SHOULD ALLOW SUB FREEZING TEMPERATURES TO REACH ALL BEACHES. LOOKS LIKE 10 TO 13 HOURS OF SUBFREEZING TEMPERATURES WILL OCCUR ACROSS FAR INLAND AREAS RANGING TO 2 TO 4 HOURS AT THE GEORGIA BEACHES. HAVE ISSUED A FREEZE WATCH FOR ALL AREAS FOR TUESDAY NIGHT. SINCE LOW TEMPERATURES ARE EXPECTED TO BE WELL BELOW FREEZING FOR MANY HOURS...PRECAUTIONS NEED TO BE TAKEN TO PROTECT EXPOSED PIPES. WEDNESDAY THROUGH THURSDAY...AFTER A FRIGID START ON WEDNESDAY MORNING...ABUNDANT SUNSHINE WILL HELP TEMPERATURES RECOVER TO NEAR 50 DEGREES IN MANY AREAS. WITH THE HIGH PRESSURE CENTERED NEAR THE AREA...WINDS WILL BE LIGHT...SO THERE WILL NOT BE ANY DOWNSLOPE FLOW TO HELP MODERATE TEMPERATURES MORE QUICKLY. A GOOD RADIATIONAL COOLING NIGHT IS EXPECTED WEDNESDAY NIGHT ACROSS THE AREA. HOWEVER...INCREASING LOW LEVEL THICKNESS VALUES AND HIGHER DEWPOINTS THAN TUESDAY NIGHT WILL KEEP TEMPERATURES FROM FALLING TO TUESDAY NIGHTS LEVELS. EXPECT FREEZING TEMPERATURES IN MOST AREAS...WITH LOWS IN THE MID TO UPPER 20S INLAND TO THE MID 30S NEAR THE COAST. IN ALL LIKELIHOOD FREEZING TEMPERATURES WILL OCCUR IN ALL AREAS TUESDAY NIGHT WHICH SHOULD EFFECTIVELY END THE GROWING SEASON. AS A RESULT...IT IS HIGHLY LIKELY THAT NO FREEZE WATCHES OR WARNINGS WILL BE ISSUED FOR WEDNESDAY NIGHT UNLESS FREEZING TEMPERATURES DO NOT OCCUR EVERYWHERE TUESDAY NIGHT. A MODERATING TREND BEGINS ON THURSDAY. ABUNDANT SUNSHINE AND INCREASING LOW LEVEL THICKNESS VALUES SUPPORT HIGH TEMPERATURES IN MOST AREA NEAR 60 DEGREES. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... DECENT CONFIDENCE IN A GENERAL MODERATING TREND DURING THIS PERIOD...WITH HIGH TEMPERATURES CLIMBING TO NEAR OR PERHAPS EVEN ABOVE NORMAL VALUES BY SUNDAY AND LIKELY TO ABOVE NORMAL LEVELS BY MONDAY. GOOD AGREEMENT BETWEEN ECMWF AND GFS THAT THE AREA WILL LIKELY REMAIN RAIN FREE THROUGH SATURDAY. MODEL DIFFERENCES BECOME QUITE PRONOUNCED BY SUNDAY AND MONDAY...BUT IT DOES APPEAR THAT THE WEATHER WILL GET MORE UNSETTLED THEN AND AT LEAST FOR NOW INCLUDED SLIGHT CHANCES FOR RAIN SHOWERS SUNDAY THROUGH MONDAY. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... THE DENSE FOG FROM THE OVERNIGHT HAS LIFTED AT KCHS AND HAS BEEN OUT OF KSAV FOR SEVERAL HOURS. OCCASIONAL MVFR CIGS MAY OCCUR AT BOTH TERMINALS BEFORE CONVECTION MOVES THROUGH FROM 18Z TO 22Z TODAY. THERE IS A SMALL CHANCE IT REACHES KSAV BEFORE 18Z GIVEN SOME OF THE LATEST UPSTREAM RADAR TRENDS. S TO SW WINDS WILL BE RAMPING UP THIS MORNING AND PRE-FRONTAL TODAY AND SIGNIFICANT CONVECTIVE WIND GUSTS ARE POSSIBLE IN THE VICINITY OF STRONG SHOWERS AND TSTMS THIS AFTERNOON. CIGS WILL BE VFR TONIGHT IN THE WAKE OF THE COLD FRONT WITH SURFACE FLOW FROM THE NW AND PERIODS OF GUSTINESS ARE LIKELY AT BOTH TERMINALS OVERNIGHT. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL. && .MARINE... OTHERWISE INCREASING LOW LEVEL JET AND WARM AIR ADVECTION BOTH IMPRESSIVE TODAY BUT THE MIXING PROFILES ARE QUITE POOR CLOSE TO SHORE AS SEA SURFACE TEMPS ARE CLOSER TO 60F. THE LAND/SEA INTERFACE SHOULD BECOME GUSTY BY EARLY AFTERNOON AND ALLOWED AN SCA TO CONTINUE NORTH OF SAVANNAH TODAY. THE TWO MOST SIGNIFICANT ISSUES WILL BE CONVECTION LATER TODAY AND POSSIBLE GALES OVER THE GEORGIA WATERS TONIGHT. THE CONVECTION WILL PRODUCE A RISK OF WIND GUSTS OVER 35 KT AND POSSIBLE WATERSPOUTS ESPECIALLY OVER WATERS SEAWARD FROM THE PILOT BUOYS. THE TIMING LOOKS TO BE EARLY TO MID AFTERNOON THROUGH EARLY EVENING. THE GALE RISK WAS HIGH ENOUGH THIS MORNING TO HOIST A GALE WATCH TONIGHT FOR THE OUTER GEORGIA WATERS. GRAYS REEF COULD SEE A PERIOD OF GALE FORCE GUSTS FROM LATE EVENING TO 6 AM AS JETTING AND LOW LEVEL MOMENTUM PROGS ARE EXTREMELY FAVORABLE GIVEN THE SHARP ISALLOBARIC RISES ANTICIPATED. OTHER WATERS WILL BE IN SMALL CRAFT ADVISORY CONDITIONS TONIGHT. TUESDAY THROUGH FRIDAY...HIGH PRESSURE WILL BUILD FROM THE WEST ON TUESDAY...WITH IMPROVING CONDITIONS ON THE WATERS. SMALL CRAFT ADVISORIES FOR AMZ352 AND AMZ354 ARE EXPECTED TO END TUESDAY MORNING. ANY GALE CONDITIONS ACROSS AMZ374 SHOULD END EARLY ON TUESDAY WITH SMALL CRAFT ADVISORY CONDITIONS THEN PERSISTING INTO TUESDAY NIGHT. IMPROVING CONDITIONS WILL THEN CONTINUE ACROSS ALL WATERS AS HIGH PRESSURE SETTLES OVER THE REGION. WINDS MAINLY AOB 10 KNOTS AND SEAS 1 TO 3 FEET ARE EXPECTED FROM WEDNESDAY MORNING INTO THURSDAY NIGHT AND POSSIBLY EVEN FRIDAY MORNING. && .CLIMATE... RECORD LOW MAXIMUM TEMPERATURES FOR NOVEMBER 18TH... KCHS...49 SET IN 2008. KCHL...48 SET IN 1951. KSAV...45 SET IN 1891. RECORD LOWS FOR NOVEMBER 19TH... KCHS...27 SET IN 1949. KCHL...31 SET IN 1903. KSAV...27 SET IN 2008 AND PREVIOUS. RECORD LOW MAXIMUM TEMPERATURES FOR NOVEMBER 19TH... KCHS...44 SET IN 2000. KCHL...45 SET IN 1951. KSAV...44 SET IN 2000. RECORD LOW FOR SO EARLY IN THE SEASON... KCHS...22 NOVEMBER 16 1940. KCHL...28 NOVEMBER 16 1940. KSAV...24 NOVEMBER 3 1954. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR GAZ087-088-099>101-114>119-137>141. SC...FREEZE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR SCZ040-042>045-047>052. LAKE WIND ADVISORY UNTIL 6 AM EST TUESDAY FOR SCZ045. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TUESDAY FOR AMZ352. SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ330-350. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO NOON EST TUESDAY FOR AMZ354. GALE WATCH FROM 7 PM EST THIS EVENING THROUGH TUESDAY MORNING FOR AMZ374. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ374. && $$ NEAR TERM...JAQ SHORT TERM...MTE LONG TERM...MTE AVIATION... MARINE...MTE CLIMATE...
AREA FORECAST DISCUSSION...CORRECTED TIMES
NWS NORTHERN INDIANA
713 PM EST TUE NOV 18 2014 .SYNOPSIS... ISSUED AT 639 PM EST TUE NOV 18 2014 LAKE EFFECT SNOW WILL DIMINISH THIS EVENING ACROSS SOUTHWESTERN MICHIGAN. A FAST MOVING DISTURBANCE DROPPING THROUGH THE NORTHERN PLAINS WILL BRING ABOUT A PERIOD OF LIGHT SNOW TO PRIMARILY AREAS ALONG AND NORTH OF HIGHWAY 30 WEDNESDAY MORNING. LOWS TONIGHT WILL RANGE FROM AROUND 10 DEGREES IN THE NORTH TO THE MIDDLE TEENS NEAR THE OHIO RIVER. HIGHS TOMORROW WILL RANGE FROM NEAR 30 OVER SOUTHERN MICHIGAN TO THE UPPER 30S ALONG THE OHIO RIVER. && .UPDATE... ISSUED AT 938 AM EST TUE NOV 18 2014 UPDATED ZONES AND GRIDS TO SHIFT HEAVIEST BANDS A BIT FURTHER NORTH BASED ON RADAR TRENDS AND SFC FLOW. HEAVIEST SNOW BANDS HAVE SHIFTED INTO BERRIEN AND CASS COUNTIES WITH A NARROW BAND OF SOMEWHAT LIGHTER SNOW OCCURRING VICINITY OF MICHIGAN CITY. POINTS EAST OF HERE WERE SEEING SCATTERED SNOW SHOWERS WITH LOCATIONS BETWEEN THE TOLL ROAD AND DOWN TO ROUGHLY US 24 IN INDIANA SEEING FLURRIES/LGT SNOW SHOWERS. THIS WAS ALL COURTESY OF A WEAK DISTURBANCE MOVING THROUGH THE AREA. WILL NEED TO WATCH ALONG/NORTH OF THE TOLL ROAD INTO EARLY AFTERNOON AS SOME INDICATIONS UPSTREAM OF FLOW BECOMING MORE WESTERLY AGAIN FOR A PERIOD. GIVEN CLEANUP STILL UNDERWAY AND RISK OF ADDITIONAL SNOW SHOWERS...WILL LEAVE WARNING ALONG FOR LA PORTE...ST JOE AND ELKHART COUNTIES IN INDIANA FOR THE TIME BEING. ADDED MENTION OF LGT SNOW SHOWERS FURTHER SOUTH GIVEN VISIBILITIES DROPPING INTO THE 3 TO 5 MILE RANGE...BIT MORE THAN FLURRIES. NO ACCUMS EXPECTED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 428 AM EST TUE NOV 18 2014 BUSY SHORT TERM THIS MORNING WITH IMPRESSIVE ONGOING LAKE EFFECT SNOW EVENT. AS FEARED AND MENTIONED IN PREVIOUS DISCUSSIONS...SOUTHERN EXTENT OF LAKE BANDS DID MAKE IT SOUTH OF THE MICHIGAN STATE LINE...A RARE OCCURRENCE FOR THESE WESTERLY FLOW EVENTS. RUC13 AND OTHER HIRES GUIDANCE SHOWED A SLIGHT VEERING TO THE 925-850MB WINDS ALONG WITH SURFACE THERMAL INDUCED CONVERGENCE WHICH ALLOWED SOUTHERN MOST BAND TO BECOME STRONGER. THIS BAND HAS PERSISTED NON STOP SINCE ABOUT 9 PM LAST NIGHT. HI RES GUIDANCE LOCKED ONTO LOW LEVEL FLOW AND ONLY SHOWING A SLIGHT BACKING THROUGH MID MORNING DESPITE A COUPLE WEAK SHORT WAVES. THIS GUIDANCE COMBINED WITH REPORTS THROUGH 1 AM OF BETWEEN 2 AND 4 INCHES OF SNOW PROMPTED THE OVERNIGHT UPGRADE TO A WARNING. BLOWING AND DRIFTING ALSO LEADING TO NUMEROUS ACCIDENTS AND ISSUES AND EXPECT MORE PROBLEMS AS MORNING TRAFFIC INCREASES. THE HIRES ARW EAST HAD A GOOD HANDLE ON THIS SOUTHERN BAND AND GENERALLY FOLLOWED IT WITH A BLEND OF RUC AND LOCAL WRF TO TWEAK SNOW FORECASTS. SATELLITE SHOWS A RATHER STRONG SHORT WAVE OVER WI HEADING SOUTH AND MODELS SEEM LOCKED ONTO THIS FEATURE...CROSSING SOUTHERN LAKE MICHIGAN THIS MORNING FOLLOWED BY INCREASING SUBSIDENCE AND BACKING LOW LEVEL FLOW. EXPECT BANDS TO PERSIST WITH ONLY MINOR FLUCTUATIONS THROUGH MID MORNING...SIMILAR TO WHAT WE HAVE SEEN OVERNIGHT. THIS WILL LEAD TO ADDITIONAL SNOWFALL RATES OF BETWEEN ONE HALF AND ONE INCH PER HOUR. GREATEST SNOWFALL AMOUNTS EARLY THIS MORNING HAVE BEEN OVER CENTRAL CASS COUNTY WITH LAST REPORTS OF 10 INCHES AROUND CASSOPOLIS SEVERAL HOURS AGO. STILL EXPECT ISOLATED AMOUNTS IN CASSOPOLIS AREA TO BE CLOSER TO 15 TO 18 INCHES BY THE TIME EVENT ENDS. REMAINDER OF AREA WILL VARY WITH AMOUNTS AS USUAL FOR LAKE EFFECT WITH 4 TO 8 LIKELY NEAR TOLL ROAD AND 8 TO 12 IN MICHIGAN. COUNTING ON COMBINATION OF SHORT WAVE AND DIURNAL TIMING TO CREATE MORE OF A CELLULAR NATURE TO BANDS LATER THIS MORNING AND AID IN REDUCING INTENSITY A BIT THROUGH THE DAY AS FLOW BACKS. STRONG WEST WINDS OF 15 TO 25 TODAY WILL CREATE HAVOC ON ROADS AND NEAR WHITEOUT CONDITIONS IN STRONGER BANDS. BASED ON 00Z FCST SOUNDINGS FROM ARW AND NAM DID INCREASE POPS FROM 00-06Z TONIGHT OVER BERRIEN AND CASS COUNTIES AS SOUTHWEST FLOW PERSISTS WITH SATURATED BUT SHRINKING DGZ. ACCUMS SHOULD BE FALLING OFF BUT STILL MAY SEE SOME LIGHT ACCUMS. REMAINDER OF AREA TO SEE CLOUDS INCREASE TODAY SIMILAR TO YESTERDAY WITH SHORT WAVE PASSING THROUGH. SOME FLURRIES POSSIBLE ONCE AGAIN. RECORD LOW MAX TEMPERATURES TODAY MOST AREAS...ACTUALLY SHATTERING RECORDS BY SEVERAL DEGREES. ALREADY BROKE THE RECORD LOW FOR TODAY AT KFWA DESPITE WIND. WIND CHILLS STILL FROM ZERO TO 10 BELOW THIS MORNING. TONIGHT...LOWS LIKELY TO OCCUR EARLY WITH TEMPS STEADY OR RISING AS CLOUD COVER INCREASES AHEAD OF NEXT SHORT WAVE. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 428 AM EST TUE NOV 18 2014 ANOTHER BOUT WITH POSSIBILITY OF SYSTEM SNOW IS EXPECTED WEDNESDAY FOLLOWED BY LAKE EFFECT SNOW WEDNESDAY NIGHT THROUGH AT LEAST THURSDAY NIGHT. THE 12KM NAM PER 285K ISENTROPIC CHART STILL SUPPORTS UP TO AN INCH OF SNOW ACCUMULATION PER GARCIA/MIXING RATIO METHOD. CONCERN FOR INCOMPLETE SATURATION OF THE CLOUD LAYER WILL LIMIT SNOWFALL. HOWEVER...GOOD LIFT IS INDICATED WITH OVER 2 G/KG OF MOISTURE. HAVE RAMPED UP LAKE EFFECT SNOW CHANCES WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS ARCTIC AIR SPREADS BACK OVER THE AREA. SFC/700 MB DELTA T VALUES BECOME SUBSTANTIAL AGAIN AROUND 30C. EVEN WITH A LIMITED FETCH...EXPECT SNOW SHOWERS TO INCREASE WEDNESDAY NIGHT AND PERSIST INTO THURSDAY AS DELTA T VALUES INCREASE AND WINDS VEER A LITTLE MORE TO THE NORTHWEST. FOR THE REST OF THE PERIOD...MUCH WARMER AIR WILL RETURN TO THE AREA THIS WEEKEND. A RAIN/SNOW MIX IS POSSIBLE SATURDAY...BUT PRECIPITATION SHOULD BECOME ALL RAIN BY SATURDAY NIGHT AS THERMAL PROFILES INDICATED LIQUID PRECIPITATION. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 639 PM EST TUE NOV 18 2014 A FAST MOVING DISTURBANCE ALOFT WILL SPREAD LIGHT SNOW ACRS THE TERMINALS JUST AFT DAYBREAK WED BEFORE ENDING BY EARLY AFTN. VIS/CIG IMPACTS XPCD TO REMAIN IN MVFR RANGE OTRWS BECOMING WINDY AGAIN W/SFC GUSTS ARND 25KTS ESP DURING THE AFTN AS SHARP LL CAA WEDGE WRAPS EWD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE THURSDAY NIGHT FOR INZ003>006. MI...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE THURSDAY NIGHT FOR MIZ077>080. WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR MIZ077-078. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 10 AM EST FRIDAY FOR LMZ043-046. && $$ UPDATE...FISHER SYNOPSIS...LOTHAMER SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
639 PM EST TUE NOV 18 2014 .SYNOPSIS... ISSUED AT 1150 AM EST TUE NOV 18 2014 LAKE EFFECT SNOW WILL DIMINISH THIS EVENING ACROSS SOUTHWESTERN MICHIGAN. A FAST MOVING DISTURBANCE DROPPING THROUGH THE NORTHERN PLAINS WILL BRING ABOUT A PERIOD OF LIGHT SNOW TO PRIMARILY AREAS ALONG AND NORTH OF HIGHWAY 30 WEDNESDAY MORNING. LOWS TONIGHT WILL RANGE FROM AROUND 10 DEGREES IN THE NORTH TO THE MIDDLE TEENS NEAR THE OHIO RIVER. HIGHS TOMORROW WILL RANGE FROM NEAR 30 OVER SOUTHERN MICHIGAN TO THE UPPER 30S ALONG THE OHIO RIVER. && .UPDATE... ISSUED AT 938 AM EST TUE NOV 18 2014 UPDATED ZONES AND GRIDS TO SHIFT HEAVIEST BANDS A BIT FURTHER NORTH BASED ON RADAR TRENDS AND SFC FLOW. HEAVIEST SNOW BANDS HAVE SHIFTED INTO BERRIEN AND CASS COUNTIES WITH A NARROW BAND OF SOMEWHAT LIGHTER SNOW OCCURRING VICINITY OF MICHIGAN CITY. POINTS EAST OF HERE WERE SEEING SCATTERED SNOW SHOWERS WITH LOCATIONS BETWEEN THE TOLL ROAD AND DOWN TO ROUGHLY US 24 IN INDIANA SEEING FLURRIES/LGT SNOW SHOWERS. THIS WAS ALL COURTESY OF A WEAK DISTURBANCE MOVING THROUGH THE AREA. WILL NEED TO WATCH ALONG/NORTH OF THE TOLL ROAD INTO EARLY AFTERNOON AS SOME INDICATIONS UPSTREAM OF FLOW BECOMING MORE WESTERLY AGAIN FOR A PERIOD. GIVEN CLEANUP STILL UNDERWAY AND RISK OF ADDITIONAL SNOW SHOWERS...WILL LEAVE WARNING ALONG FOR LA PORTE...ST JOE AND ELKHART COUNTIES IN INDIANA FOR THE TIME BEING. ADDED MENTION OF LGT SNOW SHOWERS FURTHER SOUTH GIVEN VISIBILITIES DROPPING INTO THE 3 TO 5 MILE RANGE...BIT MORE THAN FLURRIES. NO ACCUMS EXPECTED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 428 AM EST TUE NOV 18 2014 BUSY SHORT TERM THIS MORNING WITH IMPRESSIVE ONGOING LAKE EFFECT SNOW EVENT. AS FEARED AND MENTIONED IN PREVIOUS DISCUSSIONS...SOUTHERN EXTENT OF LAKE BANDS DID MAKE IT SOUTH OF THE MICHIGAN STATE LINE...A RARE OCCURRENCE FOR THESE WESTERLY FLOW EVENTS. RUC13 AND OTHER HIRES GUIDANCE SHOWED A SLIGHT VEERING TO THE 925-850MB WINDS ALONG WITH SURFACE THERMAL INDUCED CONVERGENCE WHICH ALLOWED SOUTHERN MOST BAND TO BECOME STRONGER. THIS BAND HAS PERSISTED NON STOP SINCE ABOUT 9 PM LAST NIGHT. HI RES GUIDANCE LOCKED ONTO LOW LEVEL FLOW AND ONLY SHOWING A SLIGHT BACKING THROUGH MID MORNING DESPITE A COUPLE WEAK SHORT WAVES. THIS GUIDANCE COMBINED WITH REPORTS THROUGH 1 AM OF BETWEEN 2 AND 4 INCHES OF SNOW PROMPTED THE OVERNIGHT UPGRADE TO A WARNING. BLOWING AND DRIFTING ALSO LEADING TO NUMEROUS ACCIDENTS AND ISSUES AND EXPECT MORE PROBLEMS AS MORNING TRAFFIC INCREASES. THE HIRES ARW EAST HAD A GOOD HANDLE ON THIS SOUTHERN BAND AND GENERALLY FOLLOWED IT WITH A BLEND OF RUC AND LOCAL WRF TO TWEAK SNOW FORECASTS. SATELLITE SHOWS A RATHER STRONG SHORT WAVE OVER WI HEADING SOUTH AND MODELS SEEM LOCKED ONTO THIS FEATURE...CROSSING SOUTHERN LAKE MICHIGAN THIS MORNING FOLLOWED BY INCREASING SUBSIDENCE AND BACKING LOW LEVEL FLOW. EXPECT BANDS TO PERSIST WITH ONLY MINOR FLUCTUATIONS THROUGH MID MORNING...SIMILAR TO WHAT WE HAVE SEEN OVERNIGHT. THIS WILL LEAD TO ADDITIONAL SNOWFALL RATES OF BETWEEN ONE HALF AND ONE INCH PER HOUR. GREATEST SNOWFALL AMOUNTS EARLY THIS MORNING HAVE BEEN OVER CENTRAL CASS COUNTY WITH LAST REPORTS OF 10 INCHES AROUND CASSOPOLIS SEVERAL HOURS AGO. STILL EXPECT ISOLATED AMOUNTS IN CASSOPOLIS AREA TO BE CLOSER TO 15 TO 18 INCHES BY THE TIME EVENT ENDS. REMAINDER OF AREA WILL VARY WITH AMOUNTS AS USUAL FOR LAKE EFFECT WITH 4 TO 8 LIKELY NEAR TOLL ROAD AND 8 TO 12 IN MICHIGAN. COUNTING ON COMBINATION OF SHORT WAVE AND DIURNAL TIMING TO CREATE MORE OF A CELLULAR NATURE TO BANDS LATER THIS MORNING AND AID IN REDUCING INTENSITY A BIT THROUGH THE DAY AS FLOW BACKS. STRONG WEST WINDS OF 15 TO 25 TODAY WILL CREATE HAVOC ON ROADS AND NEAR WHITEOUT CONDITIONS IN STRONGER BANDS. BASED ON 00Z FCST SOUNDINGS FROM ARW AND NAM DID INCREASE POPS FROM 00-06Z TONIGHT OVER BERRIEN AND CASS COUNTIES AS SOUTHWEST FLOW PERSISTS WITH SATURATED BUT SHRINKING DGZ. ACCUMS SHOULD BE FALLING OFF BUT STILL MAY SEE SOME LIGHT ACCUMS. REMAINDER OF AREA TO SEE CLOUDS INCREASE TODAY SIMILAR TO YESTERDAY WITH SHORT WAVE PASSING THROUGH. SOME FLURRIES POSSIBLE ONCE AGAIN. RECORD LOW MAX TEMPERATURES TODAY MOST AREAS...ACTUALLY SHATTERING RECORDS BY SEVERAL DEGREES. ALREADY BROKE THE RECORD LOW FOR TODAY AT KFWA DESPITE WIND. WIND CHILLS STILL FROM ZERO TO 10 BELOW THIS MORNING. TONIGHT...LOWS LIKELY TO OCCUR EARLY WITH TEMPS STEADY OR RISING AS CLOUD COVER INCREASES AHEAD OF NEXT SHORT WAVE. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 428 AM EST TUE NOV 18 2014 ANOTHER BOUT WITH POSSIBILITY OF SYSTEM SNOW IS EXPECTED WEDNESDAY FOLLOWED BY LAKE EFFECT SNOW WEDNESDAY NIGHT THROUGH AT LEAST THURSDAY NIGHT. THE 12KM NAM PER 285K ISENTROPIC CHART STILL SUPPORTS UP TO AN INCH OF SNOW ACCUMULATION PER GARCIA/MIXING RATIO METHOD. CONCERN FOR INCOMPLETE SATURATION OF THE CLOUD LAYER WILL LIMIT SNOWFALL. HOWEVER...GOOD LIFT IS INDICATED WITH OVER 2 G/KG OF MOISTURE. HAVE RAMPED UP LAKE EFFECT SNOW CHANCES WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS ARCTIC AIR SPREADS BACK OVER THE AREA. SFC/700 MB DELTA T VALUES BECOME SUBSTANTIAL AGAIN AROUND 30C. EVEN WITH A LIMITED FETCH...EXPECT SNOW SHOWERS TO INCREASE WEDNESDAY NIGHT AND PERSIST INTO THURSDAY AS DELTA T VALUES INCREASE AND WINDS VEER A LITTLE MORE TO THE NORTHWEST. FOR THE REST OF THE PERIOD...MUCH WARMER AIR WILL RETURN TO THE AREA THIS WEEKEND. A RAIN/SNOW MIX IS POSSIBLE SATURDAY...BUT PRECIPITATION SHOULD BECOME ALL RAIN BY SATURDAY NIGHT AS THERMAL PROFILES INDICATED LIQUID PRECIPITATION. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 633 PM EST TUE NOV 18 2014 A FAST MOVING DISTURBANCE ALOFT WILL SPREAD LIGHT SNOW ACRS THE TERMINALS JUST AFT DAYBREAK WED BEFORE ENDING BY EARLY AFTN. VIS/CIG IMPACTS XPCD TO REMAIN IN MVFR RANGE OTRWS BECOMING WINDY AGAIN W/SFC GUSTS ARND 25KTS ESP DURING THE AFTN AS SHARP LL CAA WEDGE WRAPS EWD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE THURSDAY NIGHT FOR INZ003>006. MI...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE THURSDAY NIGHT FOR MIZ077>080. WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR MIZ077-078. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 10 AM EST FRIDAY FOR LMZ043-046. && $$ UPDATE...FISHER SYNOPSIS...LOTHAMER SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
259 PM EST MON NOV 17 2014 .UPDATE... THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 255 PM EST MON NOV 17 2014 SCATTERED SNOW SHOWERS WILL DEVELOP AND CONTINUE INTO THE EVENING AS MUCH COLDER AIR SPREADS INTO THE OHIO VALLEY. VERY COLD WEATHER WILL CONTINUE THROUGH MIDWEEK...WITH CHANCES FOR SNOW AGAIN ON WEDNESDAY AS A WEAK UPPER LEVEL WAVE PASSES THROUGH THE REGION. LOW PRESSURE TRACKING INTO THE REGION OVER THE WEEKEND WILL BRING A RETURN TO UNSETTLED WEATHER ALONG WITH WARMER TEMPERATURES. && .NEAR TERM /REST OF THIS AFTERNOON THROUGH TUESDAY/... ISSUED AT 255 PM EST MON NOV 17 2014 CLEARLY DEFINED CLOUD STREETS ON THE VISIBLE SATELLITE A FEW HOURS AGO BEGAN DEVELOPING SNOW SHOWERS AND FLURRIES IN THE LAST HOUR AND THESE HAVE MADE IT INTO WEST CENTRAL INDIANA. THUS FAR THE IMPACT SEEMS TO BE VISIBILITIES ONLY AS LOW AS 2-3SM OR WITH NO VISIBILITY IMPACT AT ALL. BASED ON HRRR AND CONDITIONS UPSTREAM EXPECT THESE SNOW SHOWERS TO INCREASE IN COVERAGE ACROSS THE AREA AND POSSIBLY IN INTENSITY. WILL CONTINUE TO CARRY SCATTERED SNOW SHOWERS THROUGH EARLY THIS EVENING. ONLY CHANGE WAS TO CUT OFF TIMING A LITTLE EARLY BASED ON LATEST HRRR GUIDANCE. APPEARS THESE CONVECTIVE SNOW SHOWERS SHOULD BE WANING SIGNIFICANTLY AFTER 00Z...AND TRIED TO DEPICT THIS IN THE GRIDS. OPTED TO STICK WITH AN SPS TO HANDLE THE SCATTERED SNOW SHOWERS AND GUSTY WINDS WHICH COULD CAUSE SOME POTENTIAL TRAVEL CONCERNS...ESPECIALLY FOR THE EVENING COMMUTE. THE HWO AND WX STORY WILL ALSO REFLECT THE IMPACTS OF LATE AFTERNOON AND EVENING TRAVEL WX. LEFT IN CHANCES FOR FLURRIES FOR OVERNIGHT AND TUESDAY AS ENERGY FROM UPPER LEVEL SYSTEM CONTINUES TO ROTATE THROUGH THE REGION. BIG STORY THEN TURNS TO TEMPS AS 850MB TEMPS PLUMMET TO -20-22 TONIGHT. THIS WILL ALLOW LOWS TO GET DOWN TO 7-10 FOR THE CWA TONIGHT...AND COMBINED WITH THE GUSTY WESTERLY WINDS...WIND CHILLS WILL BE IN THE 0 TO -10 RANGE BY EARLY TUESDAY MORNING. ALREADY THIS AFTERNOON CENTRAL INDIANA IS FEELING THE IMPACT OF WIND CHILLS IN THE LOW TEENS TO SINGLE DIGITS. TUESDAY MAY BREAK THE RECORD FOR LOW MAXIMUM WITH HIGHS NOT EXPECTED TO GET OUT OF THE LOW 20S. FORECASTING 19 FOR KIND WITH HIGHS ONLY IN THE HIGH TEENS ACROSS THE NORTH TO LOW 20S FAR SOUTHERN COUNTIES. AGAIN WE WILL BE PLAGUED WITH STRONG WINDS THAT WILL MAKE FOR COLD WIND CHILLS EVEN DURING THE MIDDLE OF THE DAY IN THE SINGLE DIGITS. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... ISSUED AT 255 PM EST MON NOV 17 2014 FORECAST CONCERNS FOR THE SHORT TERM CONTINUE TO BE SNOW CHANCES ON WEDNESDAY AND THE MUCH BELOW AVERAGE TEMPERATURES. THE PERIOD WILL BEGIN DRY AS THE AREA IS SANDWICHED BETWEEN LOW PRESSURE NEAR THE WESTERN GREAT LAKES AND HIGH PRESSURE ACROSS THE SOUTHEASTERN CONUS. TEMPERATURES WILL REMAIN WELL BELOW NORMAL FOR TUESDAY NIGHT. HOWEVER...WITH SOME WARM ADVECTION KICKING IN DURING THE OVERNIGHT HOURS...READINGS SHOULD STAY OUT OF THE SINGLE DIGITS. WEAK WARM ADVECTION AHEAD OF A COLD FRONT LOOKS TO ALLOW TEMPERATURES TO REACH AT LEAST THE FREEZING MARK ON WEDNESDAY...FOR THE FIRST TIME IN SEVERAL DAYS. ALTHOUGH MOISTURE PROFILES ARE NOT INCREDIBLY IMPRESSIVE PER MODEL SOUNDINGS...SOME LIGHT SNOW SHOWERS ARE NOT OUT OF THE QUESTION WITH FRONTAL PASSAGE...MAINLY ACROSS THE NORTHERN TWO THIRDS OF THE AREA CLOSEST TO THE BEST FORCING ASSOCIATED WITH AN UPPER WAVE. DRY CONDITIONS WILL RETURN ON THURSDAY AS SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE AREA FROM THE SOUTH. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ISSUED AT 255 PM EST MON NOV 17 2014 MODEL ENSEMBLES INDICATE WE WILL BE TRANSITIONING FROM COLD AND DRY WEATHER THURSDAY NIGHT AND FRIDAY...TO MILD AND WET WEATHER BY THE MIDDLE OF THE WEEKEND ON. A STRONG UPPER TROUGH OVER THE EAST COAST ON FRIDAY WILL MVOE TO THE EAST AS MODELS MOVE AN UPPER TROUGH INITIALLY NEAR THE PACIFIC COAST TO THE UPPER MIDWEST AND CENTRAL PLAINS BY MONDAY. AT THE SURFACE HIGH PRESSURE WILL BE ACROSS OUR REGION FRIDAY AS A WARM FRONT DEVELOPS OVER THE SOUTHERN PLAINS INTO THE DEEP SOUTH. MODELS HAVE TRENDED IN MOVING PRECIPITATION QUICKER OUR WAY IN THE LATEST RUN. THEY ALL BRING IN SOME PRECIPITATION FRIDAY NIGHT AND INCREASE IT OVER THE WEEKEND AS STRONG LOW PRESSURE MOVES INTO THE CENTRAL PLAINS AND EVENTUALLY INTO THE WESTERN GREAT LAKES. WITH TEMPERATURES WARMING UP...PRECIPITATION TYPE WILL BE A BIG ISSUE FRIDAY NIGHT INTO SATURDAY. INCREASING LOW LEVEL THICKNESS ALONG WITH SURFACE TEMPERATURES BELOW 32 INDICATE FREEZING RAIN THE MOST LIKELY TYPE SOUTH HALF FRIDAY NIGHT AND MOST AREAS SATURDAY MORNING. WILL MENTION CHANCE OF FREEZING RAIN THOSE AREAS THEN AND THEN ALL RAIN FROM SATURDAY AFTERNOON ON. CONCERNING TEMPERATURES...WENT A LITTLE WARMER THAN MOS BLEND FRIDAY NIGHT AS MODELS BRING IN CLOUDS ALONG WITH WARM ADVECTION. OTHERWISE...ONLY MINOR TWEAKS MADE TO SUPERBLEND TEMPERATURES MOST OTHER PERIODS. && .AVIATION /DISCUSSION FOR THE 171800Z TAF ISSUANCE/... ISSUED AT 1200 PM EST MON NOV 17 2014 MOSTLY MVFR CEILINGS WITH SCATTERED LIGHT SNOW SHOWERS THROUGH THIS EVENING. THEN VFR LATE TONIGHT UNTIL MIDDAY TUESDAY. SATELLITE AND WEATHER DEPICTION INDICATED BROKEN TO SCATTERED CLOUDS AROUND 25 HUNDRED FEET ACROSS THE AREA. WITH STRONG COLD ADVECTION AIRMASS WILL BECOME MORE UNSTABLE LATE THIS AFTERNOON AND EARLY TONIGHT AS AN UPPER TROUGH MOVES INTO OUR AREA. SEVERAL HIGH RESOLUTION MODELS HINT AT DEVELOPMENT OF SNOW SHOWERS WHICH COULD CAUSE RAPID FLUCTUATION IN VISIBILITIES BY 20Z AND LASTING AT LEAST THROUGH MIDNIGHT. WILL ADD A PREVAILING 4 MILES AND SNOW SHOWERS BEGINNING 20Z...ALTHOUGH VISIBILITIES COULD BE BRIEFLY LOWER. AIRMASS WILL BECOME MORE STABLE LATE TONIGHT AND EXPECT MOSTLY VFR WITH SCATTERED CLOUDS AFTER 07Z. WEST SURFACE WINDS MAY PRODUCE WIND GUSTS UP TO 25 KNOTS AT TIMES THIS AFTERNOON AND EARLY TONIGHT. OTHERWISE...WEST OR SOUTHWEST WINDS UP TO 12 KNOTS WILL BE THE RULE LATE TONIGHT AND TUESDAY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF SHORT TERM...LEE LONG TERM....JEH AVIATION...JEH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1200 PM EST MON NOV 17 2014 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 SCATTERED SNOW SHOWERS WILL DEVELOP AND CONTINUE INTO THE EVENING AS MUCH COLDER AIR SPREADS INTO THE OHIO VALLEY. VERY COLD WEATHER WILL CONTINUE THROUGH MIDWEEK...WITH CHANCES FOR SNOW AGAIN ON WEDNESDAY AS A WEAK UPPER LEVEL WAVE PASSES THROUGH THE REGION. LOW PRESSURE TRACKING INTO THE REGION OVER THE WEEKEND WILL BRING A RETURN TO UNSETTLED WEATHER ALONG WITH WARMER TEMPERATURES. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1121 AM EST MON NOV 17 2014 THE REMAINING COUNTIES IN THE WINTER WEATHER ADVISORY WERE CANCELLED AS THE SNOW HAS SINCE EXITED THE REGION. DRIER AIR IS WRAPPING BACK INTO THE REGION AND HAS EVEN BROUGHT A FEW PEAKS OF SUNSHINE WHICH SHOULD CONTINUE THROUGH MIDDAY. THE COLD POOL WILL BEGIN TO SETTLE OVER THE REGION DURING THE AFTERNOON AS THE UPPER LOW PINWHEELS INTO THE NORTHERN GREAT LAKES. THE POTENTIAL FOR SCATTERED SHOWERS AND FLURRIES TO DEVELOP...WHICH HAS BEEN DISCUSSED THE PAST FEW DAYS...HAS ALREADY COME TO FRUITION OVER A GOOD PORTION OF CENTRAL INDIANA. INCREASED POPS HERE TO HIGH CHANCE FOR SCATTERED SNOW SHOWERS AND CONTINUED MENTION OF SCATTERED FLURRIES ELSEWHERE. AGREE WITH PREVIOUS THINKING THAT MODELS IN GENERAL TEND TO STRUGGLE IN THIS SETUP AND OFTEN UNDERDO THE SNOW POTENTIAL BECAUSE THEY DO NOT CAPTURE THE MESOSCALE FEATURES WELL. AND INDEED THAT APPEARS TO BE THE CASE AS ALL OF THE REGULAR SHORT TERM GUIDANCE IS NOT PICKING UP ON THESE CURRENT SNOW SHOWERS AND FLURRIES...NOR SHOWING ANYTHING DEVELOP LATER THIS AFTERNOON AND EVENING. HOWEVER THE WRF AND EVEN THE HRRR ARE PICKING UP ON THIS TREND AND SHOW THESE SCATTERED SNOW SHOWERS INCREASING BOTH IN COVERAGE OVER THE COUNTY WARNING AREA...AND INTENSITY. THESE MODELS ARE CLEARLY SUPPORTING SCATTERED CONVECTIVE SNOW SHOWERS AND POSSIBLY SQUALLS LATER THIS AFTERNOON AND INTO THE EVENING WHILE THE NAM/GFS/EURO/GEM HAVE ABSOLUTELY NO PRECIP ACROSS THE AREA. IF THE WRF/HRRR ARE CORRECT...AND COMBINED WITH THE GUSTY WESTERLY WINDS OF 30 MPH EXPECTED...THIS COULD CAUSE SOME POTENTIALLY SIGNIFICANT TRAVEL CONCERNS AND ESPECIALLY FOR THE EVENING COMMUTE. AN SPS FOR THE ABOVE CONCERNS WAS ISSUED EARLIER THIS MORNING AND JUST RECENTLY UPDATED AND RESENT. POPS WERE ALSO INCREASED ACROSS MOST OF THE REST OF THE CWA BASED ON THE WRF/HRRR TIMING TO HIT HARDER ON THE CHANCES FOR WIDESPREAD SCATTERED SNOW SHOWERS. THE HWO AND WX STORY ALSO REFLECT THIS MESSAGE...QUESTION THEN IS IS ANOTHER ADVISORY NEEDED FOR THE EVENING COMMUTE IF POTENTIALLY WHITE OUT CONDITIONS ARE POSSIBLE? EVEN THOUGH NO TECHNICAL CRITERIA FOR A WINTER WX ADVISORY OR HEAVY SNOW ADVISORY WILL BE MET...AS THE SNOW FALL ACCUMULATIONS ARE EXPECTED TO BE MINIMAL IF AT ALL ANY ACCUM...THE IMPACT COULD BE THERE AND THAT IS WHAT WILL BE LOOKED AT AND DISCUSSED IN THE VERY NEAR TERM. AND AS MENTIONED IN THE PREVIOUS DISCUSSION...THE EVENING COMMUTE MIGHT BE OF GREATER CONCERN THAN THIS MORNING/S. WHILE SNOWFALL WILL BE ONLY A DUSTING TO A FEW TENTHS OF AN INCH AT BEST...THE SNOW WILL BE DRIER AND MUCH EASIER TO BLOW AROUND WITH THE POTENTIAL FOR LOCALLY REDUCED VISIBILITIES IN HEAVIER SNOW SHOWERS. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 331 AM EST MON NOV 17 2014 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AND SNOW CHANCES...PRIMARILY WEDNESDAY. AN EVEN STRONGER BLAST OF COLD AIR OF POLAR ORIGIN POISED TO OVERSPREAD THE OHIO VALLEY AND GREAT LAKES FOR MOST OF THE SHORT TERM. AFOREMENTIONED SCATTERED SNOW SHOWERS WILL BE ONGOING THIS EVENING...LIKELY NOT DIMINISHING IN INTENSITY AND COVERAGE UNTIL CLOSER TO MIDNIGHT. WILL MAINTAIN SCATTERED FLURRIES OVERNIGHT WITH STILL PLENTY OF FORCING ALOFT AND WILL HAVE TO MONITOR AS COULD EVEN SEE A FEW SNOW SHOWERS LINGER WELL INTO THE OVERNIGHT. UPPER TROUGH AND COLD POOL ALOFT CENTERED OVER THE REGION EARLY TUESDAY...GRADUALLY LIFTING OUT BY LATE TUESDAY AS THE UPPER LOW SHIFTS EAST INTO QUEBEC. WILL MAINTAIN A MENTION OF SCATTERED FLURRIES INTO THE AFTERNOON...ENDING FROM WEST TO EAST AS FORCING ALOFT WEAKENS. WEAK SURFACE RIDGING WILL QUICKLY TRACK ACROSS THE REGION TUESDAY NIGHT BRINGING A BRIEF PERIOD OF CLEARING BEFORE CLOUDS INCREASE IN ADVANCE OF ANOTHER APPROACHING WAVE ALOFT FROM THE NORTHWEST. THE UPPER WAVE WILL SWING ACROSS THE LOWER GREAT LAKES WEDNESDAY WITH LIGHT SNOW SHOWERS IMPACTING PRIMARILY THE NORTHERN HALF OF THE FORECAST AREA. COULD SEE SOME VERY LIGHT ACCUMS NORTH OF I-70 FROM A DUSTING UP TO CLOSE TO AN INCH IN FAR NORTHERN COUNTIES BY LATE DAY WEDNESDAY. BUMPED UP TO CHANCE POPS IN THE NORTH WEDNESDAY. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE REESTABLISHES ALONG WITH A RENEWED SURGE OF COLDER AIR. TEMPS...DEFINITELY THE BIG STORY OF THE SHORT TERM. UNDERCUT MOS GUIDANCE FOR LOWS TONIGHT WITH SNOWCOVER AND 850MB TEMPS BOTTOMING OUT AT -21 TO -20C BY TUESDAY MORNING. THINK MOST LOCATIONS GET INTO THE SINGLE DIGITS. ONLY MODEST RECOVERY FOR TUESDAY AS HIGHS WILL END UP RIGHT AROUND 20. LEANED CLOSER TO COOLER END OF GUIDANCE THE REST OF THE WAY...WITH HIGHS RECOVERING INTO THE LOWER/MID 30S FOR WEDNESDAY. INDY RECORDS FOR TUESDAY...RECORD LOW IS 5 (1880) AND RECORD LOW MAX TEMP IS 20 (1880). POTENTIAL FOR THE FIRST SINGLE DIGIT LOW IN NOVEMBER SINCE 11/30/1976. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 331 AM EST MON NOV 17 2014 ENSEMBLES SUGGEST A DEEP UPPER TROUGH INITIALLY OVER THE EASTERN PARTS OF THE COUNTRY WILL BE LIFTING OFF TO THE NORTHEAST BY LATE IN THE WEEK...LEAVING A MORE ZONAL FLOW OVER THE LOCAL AREA. THE NEXT SYSTEM THAT MAY AFFECT THE AREA DURING THIS PERIOD WILL BE A DISTURBANCE OF PACIFIC ORIGIN. THERE IS STILL QUITE A BIT OF SPREAD AMONG THE ENSEMBLES AS TO THE TIMING OF THIS FEATURE...FROM AS EARLY AS FRIDAY NIGHT TO AS LATE AS SATURDAY NIGHT OR SUNDAY. FOR NOW...WILL BROADBRUSH POPS STARTING FRIDAY NIGHT THROUGH NEXT SUNDAY. THERE MAY STILL BE ENOUGH RESIDUAL COLD AIR AROUND FOR MIXED PRECIPITATION OVER PARTS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT...BUT ENSEMBLES SUGGEST LITTLE THREAT FOR SIGNIFICANT ACCUMULATIONS AT THIS TIME. && .AVIATION /DISCUSSION FOR THE 171800Z TAF ISSUANCE/... ISSUED AT 1200 PM EST MON NOV 17 2014 MOSTLY MVFR CEILINGS WITH SCATTERED LIGHT SNOW SHOWERS THROUGH THIS EVENING. THEN VFR LATE TONIGHT UNTIL MIDDAY TUESDAY. SATELLITE AND WEATHER DEPICTION INDICATED BROKEN TO SCATTERED CLOUDS AROUND 25 HUNDRED FEET ACROSS THE AREA. WITH STRONG COLD ADVECTION AIRMASS WILL BECOME MORE UNSTABLE LATE THIS AFTERNOON AND EARLY TONIGHT AS AN UPPER TROUGH MOVES INTO OUR AREA. SEVERAL HIGH RESOLUTION MODELS HINT AT DEVELOPMENT OF SNOW SHOWERS WHICH COULD CAUSE RAPID FLUCTUATION IN VISIBILITIES BY 20Z AND LASTING AT LEAST THROUGH MIDNIGHT. WILL ADD A PREVAILING 4 MILES AND SNOW SHOWERS BEGINNING 20Z...ALTHOUGH VISIBILITIES COULD BE BRIEFLY LOWER. AIRMASS WILL BECOME MORE STABLE LATE TONIGHT AND EXPECT MOSTLY VFR WITH SCATTERED CLOUDS AFTER 07Z. WEST SURFACE WINDS MAY PRODUCE WIND GUSTS UP TO 25 KNOTS AT TIMES THIS AFTERNOON AND EARLY TONIGHT. OTHERWISE...WEST OR SOUTHWEST WINDS UP TO 12 KNOTS WILL BE THE RULE LATE TONIGHT AND TUESDAY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMF/RYAN NEAR TERM...SMF SHORT TERM...RYAN LONG TERM....JAS AVIATION...JH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1148 AM EST MON NOV 17 2014 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 SCATTERED SNOW SHOWERS WILL DEVELOP AND CONTINUE INTO THE EVENING AS MUCH COLDER AIR SPREADS INTO THE OHIO VALLEY. VERY COLD WEATHER WILL CONTINUE THROUGH MIDWEEK...WITH CHANCES FOR SNOW AGAIN ON WEDNESDAY AS A WEAK UPPER LEVEL WAVE PASSES THROUGH THE REGION. LOW PRESSURE TRACKING INTO THE REGION OVER THE WEEKEND WILL BRING A RETURN TO UNSETTLED WEATHER ALONG WITH WARMER TEMPERATURES. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1121 AM EST MON NOV 17 2014 THE REMAINING COUNTIES IN THE WINTER WEATHER ADVISORY WERE CANCELLED AS THE SNOW HAS SINCE EXITED THE REGION. DRIER AIR IS WRAPPING BACK INTO THE REGION AND HAS EVEN BROUGHT A FEW PEAKS OF SUNSHINE WHICH SHOULD CONTINUE THROUGH MIDDAY. THE COLD POOL WILL BEGIN TO SETTLE OVER THE REGION DURING THE AFTERNOON AS THE UPPER LOW PINWHEELS INTO THE NORTHERN GREAT LAKES. THE POTENTIAL FOR SCATTERED SHOWERS AND FLURRIES TO DEVELOP...WHICH HAS BEEN DISCUSSED THE PAST FEW DAYS...HAS ALREADY COME TO FRUITION OVER A GOOD PORTION OF CENTRAL INDIANA. INCREASED POPS HERE TO HIGH CHANCE FOR SCATTERED SNOW SHOWERS AND CONTINUED MENTION OF SCATTERED FLURRIES ELSEWHERE. AGREE WITH PREVIOUS THINKING THAT MODELS IN GENERAL TEND TO STRUGGLE IN THIS SETUP AND OFTEN UNDERDO THE SNOW POTENTIAL BECAUSE THEY DO NOT CAPTURE THE MESOSCALE FEATURES WELL. AND INDEED THAT APPEARS TO BE THE CASE AS ALL OF THE REGULAR SHORT TERM GUIDANCE IS NOT PICKING UP ON THESE CURRENT SNOW SHOWERS AND FLURRIES...NOR SHOWING ANYTHING DEVELOP LATER THIS AFTERNOON AND EVENING. HOWEVER THE WRF AND EVEN THE HRRR ARE PICKING UP ON THIS TREND AND SHOW THESE SCATTERED SNOW SHOWERS INCREASING BOTH IN COVERAGE OVER THE COUNTY WARNING AREA...AND INTENSITY. THESE MODELS ARE CLEARLY SUPPORTING SCATTERED CONVECTIVE SNOW SHOWERS AND POSSIBLY SQUALLS LATER THIS AFTERNOON AND INTO THE EVENING WHILE THE NAM/GFS/EURO/GEM HAVE ABSOLUTELY NO PRECIP ACROSS THE AREA. IF THE WRF/HRRR ARE CORRECT...AND COMBINED WITH THE GUSTY WESTERLY WINDS OF 30 MPH EXPECTED...THIS COULD CAUSE SOME POTENTIALLY SIGNIFICANT TRAVEL CONCERNS AND ESPECIALLY FOR THE EVENING COMMUTE. AN SPS FOR THE ABOVE CONCERNS WAS ISSUED EARLIER THIS MORNING AND JUST RECENTLY UPDATED AND RESENT. POPS WERE ALSO INCREASED ACROSS MOST OF THE REST OF THE CWA BASED ON THE WRF/HRRR TIMING TO HIT HARDER ON THE CHANCES FOR WIDESPREAD SCATTERED SNOW SHOWERS. THE HWO AND WX STORY ALSO REFLECT THIS MESSAGE...QUESTION THEN IS IS ANOTHER ADVISORY NEEDED FOR THE EVENING COMMUTE IF POTENTIALLY WHITE OUT CONDITIONS ARE POSSIBLE? EVEN THOUGH NO TECHNICAL CRITERIA FOR A WINTER WX ADVISORY OR HEAVY SNOW ADVISORY WILL BE MET...AS THE SNOW FALL ACCUMULATIONS ARE EXPECTED TO BE MINIMAL IF AT ALL ANY ACCUM...THE IMPACT COULD BE THERE AND THAT IS WHAT WILL BE LOOKED AT AND DISCUSSED IN THE VERY NEAR TERM. AND AS MENTIONED IN THE PREVIOUS DISCUSSION...THE EVENING COMMUTE MIGHT BE OF GREATER CONCERN THAN THIS MORNING/S. WHILE SNOWFALL WILL BE ONLY A DUSTING TO A FEW TENTHS OF AN INCH AT BEST...THE SNOW WILL BE DRIER AND MUCH EASIER TO BLOW AROUND WITH THE POTENTIAL FOR LOCALLY REDUCED VISIBILITIES IN HEAVIER SNOW SHOWERS. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 331 AM EST MON NOV 17 2014 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AND SNOW CHANCES...PRIMARILY WEDNESDAY. AN EVEN STRONGER BLAST OF COLD AIR OF POLAR ORIGIN POISED TO OVERSPREAD THE OHIO VALLEY AND GREAT LAKES FOR MOST OF THE SHORT TERM. AFOREMENTIONED SCATTERED SNOW SHOWERS WILL BE ONGOING THIS EVENING...LIKELY NOT DIMINISHING IN INTENSITY AND COVERAGE UNTIL CLOSER TO MIDNIGHT. WILL MAINTAIN SCATTERED FLURRIES OVERNIGHT WITH STILL PLENTY OF FORCING ALOFT AND WILL HAVE TO MONITOR AS COULD EVEN SEE A FEW SNOW SHOWERS LINGER WELL INTO THE OVERNIGHT. UPPER TROUGH AND COLD POOL ALOFT CENTERED OVER THE REGION EARLY TUESDAY...GRADUALLY LIFTING OUT BY LATE TUESDAY AS THE UPPER LOW SHIFTS EAST INTO QUEBEC. WILL MAINTAIN A MENTION OF SCATTERED FLURRIES INTO THE AFTERNOON...ENDING FROM WEST TO EAST AS FORCING ALOFT WEAKENS. WEAK SURFACE RIDGING WILL QUICKLY TRACK ACROSS THE REGION TUESDAY NIGHT BRINGING A BRIEF PERIOD OF CLEARING BEFORE CLOUDS INCREASE IN ADVANCE OF ANOTHER APPROACHING WAVE ALOFT FROM THE NORTHWEST. THE UPPER WAVE WILL SWING ACROSS THE LOWER GREAT LAKES WEDNESDAY WITH LIGHT SNOW SHOWERS IMPACTING PRIMARILY THE NORTHERN HALF OF THE FORECAST AREA. COULD SEE SOME VERY LIGHT ACCUMS NORTH OF I-70 FROM A DUSTING UP TO CLOSE TO AN INCH IN FAR NORTHERN COUNTIES BY LATE DAY WEDNESDAY. BUMPED UP TO CHANCE POPS IN THE NORTH WEDNESDAY. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE REESTABLISHES ALONG WITH A RENEWED SURGE OF COLDER AIR. TEMPS...DEFINITELY THE BIG STORY OF THE SHORT TERM. UNDERCUT MOS GUIDANCE FOR LOWS TONIGHT WITH SNOWCOVER AND 850MB TEMPS BOTTOMING OUT AT -21 TO -20C BY TUESDAY MORNING. THINK MOST LOCATIONS GET INTO THE SINGLE DIGITS. ONLY MODEST RECOVERY FOR TUESDAY AS HIGHS WILL END UP RIGHT AROUND 20. LEANED CLOSER TO COOLER END OF GUIDANCE THE REST OF THE WAY...WITH HIGHS RECOVERING INTO THE LOWER/MID 30S FOR WEDNESDAY. INDY RECORDS FOR TUESDAY...RECORD LOW IS 5 (1880) AND RECORD LOW MAX TEMP IS 20 (1880). POTENTIAL FOR THE FIRST SINGLE DIGIT LOW IN NOVEMBER SINCE 11/30/1976. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 331 AM EST MON NOV 17 2014 ENSEMBLES SUGGEST A DEEP UPPER TROUGH INITIALLY OVER THE EASTERN PARTS OF THE COUNTRY WILL BE LIFTING OFF TO THE NORTHEAST BY LATE IN THE WEEK...LEAVING A MORE ZONAL FLOW OVER THE LOCAL AREA. THE NEXT SYSTEM THAT MAY AFFECT THE AREA DURING THIS PERIOD WILL BE A DISTURBANCE OF PACIFIC ORIGIN. THERE IS STILL QUITE A BIT OF SPREAD AMONG THE ENSEMBLES AS TO THE TIMING OF THIS FEATURE...FROM AS EARLY AS FRIDAY NIGHT TO AS LATE AS SATURDAY NIGHT OR SUNDAY. FOR NOW...WILL BROADBRUSH POPS STARTING FRIDAY NIGHT THROUGH NEXT SUNDAY. THERE MAY STILL BE ENOUGH RESIDUAL COLD AIR AROUND FOR MIXED PRECIPITATION OVER PARTS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT...BUT ENSEMBLES SUGGEST LITTLE THREAT FOR SIGNIFICANT ACCUMULATIONS AT THIS TIME. && .AVIATION /DISCUSSION FOR THE 171500Z KIND TAF UPDATE/... ISSUED AT 928 AM EST MON NOV 17 2014 MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS. NO OTHER CHANGES ARE NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOWS... BACK EDGE OF LOWER MVFR CEILINGS AROUND 012 CURRENTLY MOVING INTO THE WESTERN BORDER ZONES. EXTRAPOLATION AND SHORT TERM MODELS SUGGEST THESE LOWER CEILINGS WILL SCATTER OUT OVER THE TAF SITES BY 171400Z. LOW LEVEL LAPSE RATES BECOME NEAR DRY ADIABATIC BY EARLY AFTERNOON...SO EXPECTING VFR CEILINGS AROUND 040 TO DEVELOP BY THAT TIME...AS WELL AS SCATTERED SNOW SHOWERS. MODEL GUIDANCE SUGGESTS BRIEF IFR VISIBILITY RESTRICTIONS POSSIBLE IN THE HEAVIER SHOWERS...BUT DUE TO THE SCATTERED NATURE OF THE SHOWERS...WILL REFRAIN FROM AN EXPLICIT MENTION AT THIS TIME. SURFACE WINDS EXPECTED TO GRADUALLY INCREASE AS THE MORNING GOES BY...WITH GUSTS AROUND 25 KTS FROM 270-300 DEGREES EXPECTED BY THIS AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMF/RYAN NEAR TERM...SMF SHORT TERM...RYAN LONG TERM....JAS AVIATION...JAS/JH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
928 AM EST MON NOV 17 2014 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 WIDESPREAD SNOW WILL END THIS MORNING WITH SCATTERED SNOW SHOWERS INTO THE EVENING AS MUCH COLDER AIR SPREADS INTO THE OHIO VALLEY. VERY COLD WEATHER WILL CONTINUE THROUGH MIDWEEK...WITH CHANCES FOR SNOW AGAIN ON WEDNESDAY AS A WEAK UPPER LEVEL WAVE PASSES THROUGH THE REGION. LOW PRESSURE TRACKING INTO THE REGION OVER THE WEEKEND WILL BRING A RETURN TO UNSETTLED WEATHER ALONG WITH WARMER TEMPERATURES. && .NEAR TERM /REST OF TODAY/... ISSUED AT 848 AM EST MON NOV 17 2014 1345Z UPDATE...QUICK UPDATE THIS MORNING TO REMOVE COUNTIES FROM THE ADVISORY AREA WHERE THE BULK OF THE SNOW HAS ENDED. NEEDED TO DO A LITTLE EXTENSION FOR FAR SE/EASTERN TIER OF COUNTIES WHERE SNOW IS A LITTLE SLOWER THAN EXPECTED TO EXIT THE AREA THIS MORNING. THESE COUNTIES SHOULD SEE AN ADDITIONAL 1 INCH...POSSIBLY UP TO 2 INCHES BEFORE THE ADVISORY IS NOW SET TO THROUGH 11AM. ALSO MADE SOME MINOR ADJUSTMENTS TO ACCOUNT FOR THE LATEST TRENDS IN TEMP/SKY/WIND. PREVIOUS DISCUSSION FOLLOWS... STEADY SNOWFALL CONTINUES ALONG AND SOUTHEAST OF A TERRE HAUTE-INDY METRO-MUNCIE LINE AS OF 08Z. BACK EDGE OF THE PRECIP SHIELD HAS BACKPEDALED NORTHWEST OVER THE LAST 2-3 HOURS AS THE SHARP UPPER WAVE QUICKLY TRACKS INTO THE LOWER MISSISSIPPI VALLEY. TEMPS WERE GENERALLY IN THE 20S AND FALLING WITH THE INITIAL ARRIVAL OF THE ARCTIC AIRMASS. INITIAL ISSUE FOCUSES ON THE SNOW CONTINUING EARLY THIS MORNING WITH ITS DEPARTURE OFF TO THE EAST BETWEEN 12-15Z. DESPITE THE PIVOT BACK TO THE WEST OF THE PRECIP SHIELD...DO NOT EXPECT IT TO SHIFT MUCH FURTHER NORTHWEST FROM ITS CURRENT POSITION AS UPPER LEVEL ENERGY IS QUICKLY APPROACHING FROM THE SOUTHWEST WHILE THE MAIN SURFACE LOW TRACKS INTO NORTHERN GEORGIA. HRRR AND THE WRF BOTH HAVE A NICE HANDLE ON THE LOCATION OF THE SNOWFALL AND EXPECTED EVOLUTION THROUGH DAYBREAK. SNOW WILL BEGIN TO SHIFT EAST AFTER 09-10Z...WITH PRECIP ENDING OVER FAR EASTERN COUNTIES BY 14-15Z. WITH THE POTENTIAL FOR ANOTHER INCH OR TWO OF ADDITIONAL ACCUM OVER THE SOUTHEAST HALF OF THE FORECAST AREA...WILL CONTINUE WITH THE ADVISORY IN ITS CURRENT STATE THROUGH 14Z. HEAVIER SNOWFALL WILL REMAIN SOUTHEAST OF THE INDY METRO...BUT STILL QUITE POSSIBLE TO TACK ON ANOTHER HALF INCH OR SO IN THE CITY BEFORE SNOW ENDS. FURTHER NORTHWEST...EXPECT LITTLE MORE THAN FLURRIES OVER THE NEXT FEW HOURS. DRIER AIR WILL WRAP INTO THE REGION BEHIND THE SNOWFALL LATER THIS MORNING AND MAY EVEN BRING A FEW PEAKS OF SUNSHINE THROUGH MIDDAY. COLD POOL BEGINS TO SETTLE OVER THE REGION DURING THE AFTERNOON AS THE UPPER LOW PINWHEELS INTO THE NORTHERN GREAT LAKES. AS HAS BEEN DISCUSSED OVER THE LAST FEW DAYS...POTENTIAL FOR SCATTERED SNOW SHOWERS TO REDEVELOP THIS AFTERNOON AND EVENING. MODELS IN GENERAL TEND TO STRUGGLE IN THIS SETUP AND OFTEN UNDER-DO THE SNOW POTENTIAL BECAUSE THEY DO NOT CAPTURE THE MESOSCALE FEATURES WELL. THE WRF DOES A BETTER JOB IN THIS REGARD AND NOW THAT WE ARE WITHIN ITS WINDOW...IT IS SUPPORTING POTENTIAL FOR SCATTERED CONVECTIVE SNOW SHOWERS/SQUALLS LATER THIS AFTERNOON...AND THESE COULD CAUSE SOME PROBLEMS OVER THE REGION. PLENTY OF MID LEVEL ENERGY ROTATING AROUND THE BASE OF THE UPPER LOW AND THROUGH THE REGION. THIS COMBINED WITH INTENSIFYING COLD ADVECTION AND SHALLOW INSTABILITY WITH STEEPENING LAPSE RATES TO 850MB SUPPORT CONVECTIVE SNOW SHOWERS. WITH WIND GUSTS STEADILY STRENGTHENING TO AROUND 30MPH THIS AFTERNOON...THESE SNOW SHOWERS/SQUALLS HAVE THE POTENTIAL TO CREATE A GREATER IMPACT ON TRAVEL THAN THE SNOW EXPERIENCED SUNDAY NIGHT AND EARLY THIS MORNING. WHILE SNOWFALL WILL BE ONLY A DUSTING TO A FEW TENTHS OF AN INCH AT BEST...THE SNOW WILL BE DRIER AND MUCH EASIER TO BLOW AROUND WITH THE POTENTIAL FOR LOCALLY REDUCED VISIBILITIES IN HEAVIER SNOW SHOWERS. AS CRAZY AS THIS SOUNDS...HAVE A GROWING CONCERN THAT THE LATE AFTERNOON/EVENING RUSH HOUR COULD BE MORE GREATLY IMPACTED THAN THIS MORNING. WILL BE INTRODUCING AN SPS TO HIGHLIGHT THESE THREATS FOR LATER TODAY. TEMPS...HIGHS ARE TRICKY FOR TODAY CONSIDERING THEY ARE LARGELY LOWER THAN CURRENT READINGS THIS MORNING. MAY SEE A BRIEF RISE IN TEMPS THROUGH MIDDAY WITH FALLING TEMPS THEREAFTER AS THE STRONGER COLD ADVECTION ARRIVES. A MOS BLEND WAS REASONABLE FOR HIGHS...THEN USED A MIX OF NAM/LAMP DATA FOR THE FALLING TEMPS THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 331 AM EST MON NOV 17 2014 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AND SNOW CHANCES...PRIMARILY WEDNESDAY. AN EVEN STRONGER BLAST OF COLD AIR OF POLAR ORIGIN POISED TO OVERSPREAD THE OHIO VALLEY AND GREAT LAKES FOR MOST OF THE SHORT TERM. AFOREMENTIONED SCATTERED SNOW SHOWERS WILL BE ONGOING THIS EVENING...LIKELY NOT DIMINISHING IN INTENSITY AND COVERAGE UNTIL CLOSER TO MIDNIGHT. WILL MAINTAIN SCATTERED FLURRIES OVERNIGHT WITH STILL PLENTY OF FORCING ALOFT AND WILL HAVE TO MONITOR AS COULD EVEN SEE A FEW SNOW SHOWERS LINGER WELL INTO THE OVERNIGHT. UPPER TROUGH AND COLD POOL ALOFT CENTERED OVER THE REGION EARLY TUESDAY...GRADUALLY LIFTING OUT BY LATE TUESDAY AS THE UPPER LOW SHIFTS EAST INTO QUEBEC. WILL MAINTAIN A MENTION OF SCATTERED FLURRIES INTO THE AFTERNOON...ENDING FROM WEST TO EAST AS FORCING ALOFT WEAKENS. WEAK SURFACE RIDGING WILL QUICKLY TRACK ACROSS THE REGION TUESDAY NIGHT BRINGING A BRIEF PERIOD OF CLEARING BEFORE CLOUDS INCREASE IN ADVANCE OF ANOTHER APPROACHING WAVE ALOFT FROM THE NORTHWEST. THE UPPER WAVE WILL SWING ACROSS THE LOWER GREAT LAKES WEDNESDAY WITH LIGHT SNOW SHOWERS IMPACTING PRIMARILY THE NORTHERN HALF OF THE FORECAST AREA. COULD SEE SOME VERY LIGHT ACCUMS NORTH OF I-70 FROM A DUSTING UP TO CLOSE TO AN INCH IN FAR NORTHERN COUNTIES BY LATE DAY WEDNESDAY. BUMPED UP TO CHANCE POPS IN THE NORTH WEDNESDAY. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE REESTABLISHES ALONG WITH A RENEWED SURGE OF COLDER AIR. TEMPS...DEFINITELY THE BIG STORY OF THE SHORT TERM. UNDERCUT MOS GUIDANCE FOR LOWS TONIGHT WITH SNOWCOVER AND 850MB TEMPS BOTTOMING OUT AT -21 TO -20C BY TUESDAY MORNING. THINK MOST LOCATIONS GET INTO THE SINGLE DIGITS. ONLY MODEST RECOVERY FOR TUESDAY AS HIGHS WILL END UP RIGHT AROUND 20. LEANED CLOSER TO COOLER END OF GUIDANCE THE REST OF THE WAY...WITH HIGHS RECOVERING INTO THE LOWER/MID 30S FOR WEDNESDAY. INDY RECORDS FOR TUESDAY...RECORD LOW IS 5 (1880) AND RECORD LOW MAX TEMP IS 20 (1880). POTENTIAL FOR THE FIRST SINGLE DIGIT LOW IN NOVEMBER SINCE 11/30/1976. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 331 AM EST MON NOV 17 2014 ENSEMBLES SUGGEST A DEEP UPPER TROUGH INITIALLY OVER THE EASTERN PARTS OF THE COUNTRY WILL BE LIFTING OFF TO THE NORTHEAST BY LATE IN THE WEEK...LEAVING A MORE ZONAL FLOW OVER THE LOCAL AREA. THE NEXT SYSTEM THAT MAY AFFECT THE AREA DURING THIS PERIOD WILL BE A DISTURBANCE OF PACIFIC ORIGIN. THERE IS STILL QUITE A BIT OF SPREAD AMONG THE ENSEMBLES AS TO THE TIMING OF THIS FEATURE...FROM AS EARLY AS FRIDAY NIGHT TO AS LATE AS SATURDAY NIGHT OR SUNDAY. FOR NOW...WILL BROADBRUSH POPS STARTING FRIDAY NIGHT THROUGH NEXT SUNDAY. THERE MAY STILL BE ENOUGH RESIDUAL COLD AIR AROUND FOR MIXED PRECIPITATION OVER PARTS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT...BUT ENSEMBLES SUGGEST LITTLE THREAT FOR SIGNIFICANT ACCUMULATIONS AT THIS TIME. && .AVIATION /DISCUSSION FOR THE 171500Z KIND TAF UPDATE/... ISSUED AT 928 AM EST MON NOV 17 2014 MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS. NO OTHER CHANGES ARE NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOWS... BACK EDGE OF LOWER MVFR CEILINGS AROUND 012 CURRENTLY MOVING INTO THE WESTERN BORDER ZONES. EXTRAPOLATION AND SHORT TERM MODELS SUGGEST THESE LOWER CEILINGS WILL SCATTER OUT OVER THE TAF SITES BY 171400Z. LOW LEVEL LAPSE RATES BECOME NEAR DRY ADIABATIC BY EARLY AFTERNOON...SO EXPECTING VFR CEILINGS AROUND 040 TO DEVELOP BY THAT TIME...AS WELL AS SCATTERED SNOW SHOWERS. MODEL GUIDANCE SUGGESTS BRIEF IFR VISIBILITY RESTRICTIONS POSSIBLE IN THE HEAVIER SHOWERS...BUT DUE TO THE SCATTERED NATURE OF THE SHOWERS...WILL REFRAIN FROM AN EXPLICIT MENTION AT THIS TIME. SURFACE WINDS EXPECTED TO GRADUALLY INCREASE AS THE MORNING GOES BY...WITH GUSTS AROUND 25 KTS FROM 270-300 DEGREES EXPECTED BY THIS AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR INZ042- 049-057-064-065-071-072. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM....JAS AVIATION...JAS/JH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
909 AM EST MON NOV 17 2014 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 WIDESPREAD SNOW WILL END THIS MORNING WITH SCATTERED SNOW SHOWERS INTO THE EVENING AS MUCH COLDER AIR SPREADS INTO THE OHIO VALLEY. VERY COLD WEATHER WILL CONTINUE THROUGH MIDWEEK...WITH CHANCES FOR SNOW AGAIN ON WEDNESDAY AS A WEAK UPPER LEVEL WAVE PASSES THROUGH THE REGION. LOW PRESSURE TRACKING INTO THE REGION OVER THE WEEKEND WILL BRING A RETURN TO UNSETTLED WEATHER ALONG WITH WARMER TEMPERATURES. && .NEAR TERM /REST OF TODAY/... ISSUED AT 848 AM EST MON NOV 17 2014 1345Z UPDATE...QUICK UPDATE THIS MORNING TO REMOVE COUNTIES FROM THE ADVISORY AREA WHERE THE BULK OF THE SNOW HAS ENDED. NEEDED TO DO A LITTLE EXTENSION FOR FAR SE/EASTERN TIER OF COUNTIES WHERE SNOW IS A LITTLE SLOWER THAN EXPECTED TO EXIT THE AREA THIS MORNING. THESE COUNTIES SHOULD SEE AN ADDITIONAL 1 INCH...POSSIBLY UP TO 2 INCHES BEFORE THE ADVISORY IS NOW SET TO THROUGH 11AM. ALSO MADE SOME MINOR ADJUSTMENTS TO ACCOUNT FOR THE LATEST TRENDS IN TEMP/SKY/WIND. PREVIOUS DISCUSSION FOLLOWS... STEADY SNOWFALL CONTINUES ALONG AND SOUTHEAST OF A TERRE HAUTE-INDY METRO-MUNCIE LINE AS OF 08Z. BACK EDGE OF THE PRECIP SHIELD HAS BACKPEDALED NORTHWEST OVER THE LAST 2-3 HOURS AS THE SHARP UPPER WAVE QUICKLY TRACKS INTO THE LOWER MISSISSIPPI VALLEY. TEMPS WERE GENERALLY IN THE 20S AND FALLING WITH THE INITIAL ARRIVAL OF THE ARCTIC AIRMASS. INITIAL ISSUE FOCUSES ON THE SNOW CONTINUING EARLY THIS MORNING WITH ITS DEPARTURE OFF TO THE EAST BETWEEN 12-15Z. DESPITE THE PIVOT BACK TO THE WEST OF THE PRECIP SHIELD...DO NOT EXPECT IT TO SHIFT MUCH FURTHER NORTHWEST FROM ITS CURRENT POSITION AS UPPER LEVEL ENERGY IS QUICKLY APPROACHING FROM THE SOUTHWEST WHILE THE MAIN SURFACE LOW TRACKS INTO NORTHERN GEORGIA. HRRR AND THE WRF BOTH HAVE A NICE HANDLE ON THE LOCATION OF THE SNOWFALL AND EXPECTED EVOLUTION THROUGH DAYBREAK. SNOW WILL BEGIN TO SHIFT EAST AFTER 09-10Z...WITH PRECIP ENDING OVER FAR EASTERN COUNTIES BY 14-15Z. WITH THE POTENTIAL FOR ANOTHER INCH OR TWO OF ADDITIONAL ACCUM OVER THE SOUTHEAST HALF OF THE FORECAST AREA...WILL CONTINUE WITH THE ADVISORY IN ITS CURRENT STATE THROUGH 14Z. HEAVIER SNOWFALL WILL REMAIN SOUTHEAST OF THE INDY METRO...BUT STILL QUITE POSSIBLE TO TACK ON ANOTHER HALF INCH OR SO IN THE CITY BEFORE SNOW ENDS. FURTHER NORTHWEST...EXPECT LITTLE MORE THAN FLURRIES OVER THE NEXT FEW HOURS. DRIER AIR WILL WRAP INTO THE REGION BEHIND THE SNOWFALL LATER THIS MORNING AND MAY EVEN BRING A FEW PEAKS OF SUNSHINE THROUGH MIDDAY. COLD POOL BEGINS TO SETTLE OVER THE REGION DURING THE AFTERNOON AS THE UPPER LOW PINWHEELS INTO THE NORTHERN GREAT LAKES. AS HAS BEEN DISCUSSED OVER THE LAST FEW DAYS...POTENTIAL FOR SCATTERED SNOW SHOWERS TO REDEVELOP THIS AFTERNOON AND EVENING. MODELS IN GENERAL TEND TO STRUGGLE IN THIS SETUP AND OFTEN UNDER-DO THE SNOW POTENTIAL BECAUSE THEY DO NOT CAPTURE THE MESOSCALE FEATURES WELL. THE WRF DOES A BETTER JOB IN THIS REGARD AND NOW THAT WE ARE WITHIN ITS WINDOW...IT IS SUPPORTING POTENTIAL FOR SCATTERED CONVECTIVE SNOW SHOWERS/SQUALLS LATER THIS AFTERNOON...AND THESE COULD CAUSE SOME PROBLEMS OVER THE REGION. PLENTY OF MID LEVEL ENERGY ROTATING AROUND THE BASE OF THE UPPER LOW AND THROUGH THE REGION. THIS COMBINED WITH INTENSIFYING COLD ADVECTION AND SHALLOW INSTABILITY WITH STEEPENING LAPSE RATES TO 850MB SUPPORT CONVECTIVE SNOW SHOWERS. WITH WIND GUSTS STEADILY STRENGTHENING TO AROUND 30MPH THIS AFTERNOON...THESE SNOW SHOWERS/SQUALLS HAVE THE POTENTIAL TO CREATE A GREATER IMPACT ON TRAVEL THAN THE SNOW EXPERIENCED SUNDAY NIGHT AND EARLY THIS MORNING. WHILE SNOWFALL WILL BE ONLY A DUSTING TO A FEW TENTHS OF AN INCH AT BEST...THE SNOW WILL BE DRIER AND MUCH EASIER TO BLOW AROUND WITH THE POTENTIAL FOR LOCALLY REDUCED VISIBILITIES IN HEAVIER SNOW SHOWERS. AS CRAZY AS THIS SOUNDS...HAVE A GROWING CONCERN THAT THE LATE AFTERNOON/EVENING RUSH HOUR COULD BE MORE GREATLY IMPACTED THAN THIS MORNING. WILL BE INTRODUCING AN SPS TO HIGHLIGHT THESE THREATS FOR LATER TODAY. TEMPS...HIGHS ARE TRICKY FOR TODAY CONSIDERING THEY ARE LARGELY LOWER THAN CURRENT READINGS THIS MORNING. MAY SEE A BRIEF RISE IN TEMPS THROUGH MIDDAY WITH FALLING TEMPS THEREAFTER AS THE STRONGER COLD ADVECTION ARRIVES. A MOS BLEND WAS REASONABLE FOR HIGHS...THEN USED A MIX OF NAM/LAMP DATA FOR THE FALLING TEMPS THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 331 AM EST MON NOV 17 2014 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AND SNOW CHANCES...PRIMARILY WEDNESDAY. AN EVEN STRONGER BLAST OF COLD AIR OF POLAR ORIGIN POISED TO OVERSPREAD THE OHIO VALLEY AND GREAT LAKES FOR MOST OF THE SHORT TERM. AFOREMENTIONED SCATTERED SNOW SHOWERS WILL BE ONGOING THIS EVENING...LIKELY NOT DIMINISHING IN INTENSITY AND COVERAGE UNTIL CLOSER TO MIDNIGHT. WILL MAINTAIN SCATTERED FLURRIES OVERNIGHT WITH STILL PLENTY OF FORCING ALOFT AND WILL HAVE TO MONITOR AS COULD EVEN SEE A FEW SNOW SHOWERS LINGER WELL INTO THE OVERNIGHT. UPPER TROUGH AND COLD POOL ALOFT CENTERED OVER THE REGION EARLY TUESDAY...GRADUALLY LIFTING OUT BY LATE TUESDAY AS THE UPPER LOW SHIFTS EAST INTO QUEBEC. WILL MAINTAIN A MENTION OF SCATTERED FLURRIES INTO THE AFTERNOON...ENDING FROM WEST TO EAST AS FORCING ALOFT WEAKENS. WEAK SURFACE RIDGING WILL QUICKLY TRACK ACROSS THE REGION TUESDAY NIGHT BRINGING A BRIEF PERIOD OF CLEARING BEFORE CLOUDS INCREASE IN ADVANCE OF ANOTHER APPROACHING WAVE ALOFT FROM THE NORTHWEST. THE UPPER WAVE WILL SWING ACROSS THE LOWER GREAT LAKES WEDNESDAY WITH LIGHT SNOW SHOWERS IMPACTING PRIMARILY THE NORTHERN HALF OF THE FORECAST AREA. COULD SEE SOME VERY LIGHT ACCUMS NORTH OF I-70 FROM A DUSTING UP TO CLOSE TO AN INCH IN FAR NORTHERN COUNTIES BY LATE DAY WEDNESDAY. BUMPED UP TO CHANCE POPS IN THE NORTH WEDNESDAY. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE REESTABLISHES ALONG WITH A RENEWED SURGE OF COLDER AIR. TEMPS...DEFINITELY THE BIG STORY OF THE SHORT TERM. UNDERCUT MOS GUIDANCE FOR LOWS TONIGHT WITH SNOWCOVER AND 850MB TEMPS BOTTOMING OUT AT -21 TO -20C BY TUESDAY MORNING. THINK MOST LOCATIONS GET INTO THE SINGLE DIGITS. ONLY MODEST RECOVERY FOR TUESDAY AS HIGHS WILL END UP RIGHT AROUND 20. LEANED CLOSER TO COOLER END OF GUIDANCE THE REST OF THE WAY...WITH HIGHS RECOVERING INTO THE LOWER/MID 30S FOR WEDNESDAY. INDY RECORDS FOR TUESDAY...RECORD LOW IS 5 (1880) AND RECORD LOW MAX TEMP IS 20 (1880). POTENTIAL FOR THE FIRST SINGLE DIGIT LOW IN NOVEMBER SINCE 11/30/1976. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 331 AM EST MON NOV 17 2014 ENSEMBLES SUGGEST A DEEP UPPER TROUGH INITIALLY OVER THE EASTERN PARTS OF THE COUNTRY WILL BE LIFTING OFF TO THE NORTHEAST BY LATE IN THE WEEK...LEAVING A MORE ZONAL FLOW OVER THE LOCAL AREA. THE NEXT SYSTEM THAT MAY AFFECT THE AREA DURING THIS PERIOD WILL BE A DISTURBANCE OF PACIFIC ORIGIN. THERE IS STILL QUITE A BIT OF SPREAD AMONG THE ENSEMBLES AS TO THE TIMING OF THIS FEATURE...FROM AS EARLY AS FRIDAY NIGHT TO AS LATE AS SATURDAY NIGHT OR SUNDAY. FOR NOW...WILL BROADBRUSH POPS STARTING FRIDAY NIGHT THROUGH NEXT SUNDAY. THERE MAY STILL BE ENOUGH RESIDUAL COLD AIR AROUND FOR MIXED PRECIPITATION OVER PARTS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT...BUT ENSEMBLES SUGGEST LITTLE THREAT FOR SIGNIFICANT ACCUMULATIONS AT THIS TIME. && .AVIATION /DISCUSSION FOR THE 171200Z TAFS/... ISSUED AT 538 AM EST MON NOV 17 2014 BACK EDGE OF LOWER MVFR CEILINGS AROUND 012 CURRENTLY MOVING INTO THE WESTERN BORDER ZONES. EXTRAPOLATION AND SHORT TERM MODELS SUGGEST THESE LOWER CEILINGS WILL SCATTER OUT OVER THE TAF SITES BY 171400Z. LOW LEVEL LAPSE RATES BECOME NEAR DRY ADIABATIC BY EARLY AFTERNOON...SO EXPECTING VFR CEILINGS AROUND 040 TO DEVELOP BY THAT TIME...AS WELL AS SCATTERED SNOW SHOWERS. MODEL GUIDANCE SUGGESTS BRIEF IFR VISIBILITY RESTRICTIONS POSSIBLE IN THE HEAVIER SHOWERS...BUT DUE TO THE SCATTERED NATURE OF THE SHOWERS...WILL REFRAIN FROM AN EXPLICIT MENTION AT THIS TIME. SURFACE WINDS EXPECTED TO GRADUALLY INCREASE AS THE MORNING GOES BY...WITH GUSTS AROUND 25 KTS FROM 270-300 DEGREES EXPECTED BY THIS AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR INZ042- 049-057-064-065-071-072. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM....JAS AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
538 AM EST MON NOV 17 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 WIDESPREAD SNOW WILL END THIS MORNING WITH SCATTERED SNOW SHOWERS INTO THE EVENING AS MUCH COLDER AIR SPREADS INTO THE OHIO VALLEY. VERY COLD WEATHER WILL CONTINUE THROUGH MIDWEEK...WITH CHANCES FOR SNOW AGAIN ON WEDNESDAY AS A WEAK UPPER LEVEL WAVE PASSES THROUGH THE REGION. LOW PRESSURE TRACKING INTO THE REGION OVER THE WEEKEND WILL BRING A RETURN TO UNSETTLED WEATHER ALONG WITH WARMER TEMPERATURES. && .NEAR TERM /TODAY/... ISSUED AT 331 AM EST MON NOV 17 2014 STEADY SNOWFALL CONTINUES ALONG AND SOUTHEAST OF A TERRE HAUTE-INDY METRO-MUNCIE LINE AS OF 08Z. BACK EDGE OF THE PRECIP SHIELD HAS BACKPEDALED NORTHWEST OVER THE LAST 2-3 HOURS AS THE SHARP UPPER WAVE QUICKLY TRACKS INTO THE LOWER MISSISSIPPI VALLEY. TEMPS WERE GENERALLY IN THE 20S AND FALLING WITH THE INITIAL ARRIVAL OF THE ARCTIC AIRMASS. INITIAL ISSUE FOCUSES ON THE SNOW CONTINUING EARLY THIS MORNING WITH ITS DEPARTURE OFF TO THE EAST BETWEEN 12-15Z. DESPITE THE PIVOT BACK TO THE WEST OF THE PRECIP SHIELD...DO NOT EXPECT IT TO SHIFT MUCH FURTHER NORTHWEST FROM ITS CURRENT POSITION AS UPPER LEVEL ENERGY IS QUICKLY APPROACHING FROM THE SOUTHWEST WHILE THE MAIN SURFACE LOW TRACKS INTO NORTHERN GEORGIA. HRRR AND THE WRF BOTH HAVE A NICE HANDLE ON THE LOCATION OF THE SNOWFALL AND EXPECTED EVOLUTION THROUGH DAYBREAK. SNOW WILL BEGIN TO SHIFT EAST AFTER 09-10Z...WITH PRECIP ENDING OVER FAR EASTERN COUNTIES BY 14-15Z. WITH THE POTENTIAL FOR ANOTHER INCH OR TWO OF ADDITIONAL ACCUM OVER THE SOUTHEAST HALF OF THE FORECAST AREA...WILL CONTINUE WITH THE ADVISORY IN ITS CURRENT STATE THROUGH 14Z. HEAVIER SNOWFALL WILL REMAIN SOUTHEAST OF THE INDY METRO...BUT STILL QUITE POSSIBLE TO TACK ON ANOTHER HALF INCH OR SO IN THE CITY BEFORE SNOW ENDS. FURTHER NORTHWEST...EXPECT LITTLE MORE THAN FLURRIES OVER THE NEXT FEW HOURS. DRIER AIR WILL WRAP INTO THE REGION BEHIND THE SNOWFALL LATER THIS MORNING AND MAY EVEN BRING A FEW PEAKS OF SUNSHINE THROUGH MIDDAY. COLD POOL BEGINS TO SETTLE OVER THE REGION DURING THE AFTERNOON AS THE UPPER LOW PINWHEELS INTO THE NORTHERN GREAT LAKES. AS HAS BEEN DISCUSSED OVER THE LAST FEW DAYS...POTENTIAL FOR SCATTERED SNOW SHOWERS TO REDEVELOP THIS AFTERNOON AND EVENING. MODELS IN GENERAL TEND TO STRUGGLE IN THIS SETUP AND OFTEN UNDERDO THE SNOW POTENTIAL BECAUSE THEY DO NOT CAPTURE THE MESOSCALE FEATURES WELL. THE WRF DOES A BETTER JOB IN THIS REGARD AND NOW THAT WE ARE WITHIN ITS WINDOW...IT IS SUPPORTING POTENTIAL FOR SCATTERED CONVECTIVE SNOW SHOWERS/SQUALLS LATER THIS AFTERNOON...AND THESE COULD CAUSE SOME PROBLEMS OVER THE REGION. PLENTY OF MID LEVEL ENERGY ROTATING AROUND THE BASE OF THE UPPER LOW AND THROUGH THE REGION. THIS COMBINED WITH INTENSIFYING COLD ADVECTION AND SHALLOW INSTABILITY WITH STEEPENING LAPSE RATES TO 850MB SUPPORT CONVECTIVE SNOW SHOWERS. WITH WIND GUSTS STEADILY STRENGTHENING TO AROUND 30MPH THIS AFTERNOON...THESE SNOW SHOWERS/SQUALLS HAVE THE POTENTIAL TO CREATE A GREATER IMPACT ON TRAVEL THAN THE SNOW EXPERIENCED SUNDAY NIGHT AND EARLY THIS MORNING. WHILE SNOWFALL WILL BE ONLY A DUSTING TO A FEW TENTHS OF AN INCH AT BEST...THE SNOW WILL BE DRIER AND MUCH EASIER TO BLOW AROUND WITH THE POTENTIAL FOR LOCALLY REDUCED VISIBILITIES IN HEAVIER SNOW SHOWERS. AS CRAZY AS THIS SOUNDS...HAVE A GROWING CONCERN THAT THE LATE AFTERNOON/EVENING RUSH HOUR COULD BE MORE GREATLY IMPACTED THAN THIS MORNING. WILL BE INTRODUCING AN SPS TO HIGHLIGHT THESE THREATS FOR LATER TODAY. TEMPS...HIGHS ARE TRICKY FOR TODAY CONSIDERING THEY ARE LARGELY LOWER THAN CURRENT READINGS THIS MORNING. MAY SEE A BRIEF RISE IN TEMPS THROUGH MIDDAY WITH FALLING TEMPS THEREAFTER AS THE STRONGER COLD ADVECTION ARRIVES. A MOS BLEND WAS REASONABLE FOR HIGHS...THEN USED A MIX OF NAM/LAMP DATA FOR THE FALLING TEMPS THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 331 AM EST MON NOV 17 2014 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AND SNOW CHANCES...PRIMARILY WEDNESDAY. AN EVEN STRONGER BLAST OF COLD AIR OF POLAR ORIGIN POISED TO OVERSPREAD THE OHIO VALLEY AND GREAT LAKES FOR MOST OF THE SHORT TERM. AFOREMENTIONED SCATTERED SNOW SHOWERS WILL BE ONGOING THIS EVENING...LIKELY NOT DIMINISHING IN INTENSITY AND COVERAGE UNTIL CLOSER TO MIDNIGHT. WILL MAINTAIN SCATTERED FLURRIES OVERNIGHT WITH STILL PLENTY OF FORCING ALOFT AND WILL HAVE TO MONITOR AS COULD EVEN SEE A FEW SNOW SHOWERS LINGER WELL INTO THE OVERNIGHT. UPPER TROUGH AND COLD POOL ALOFT CENTERED OVER THE REGION EARLY TUESDAY...GRADUALLY LIFTING OUT BY LATE TUESDAY AS THE UPPER LOW SHIFTS EAST INTO QUEBEC. WILL MAINTAIN A MENTION OF SCATTERED FLURRIES INTO THE AFTERNOON...ENDING FROM WEST TO EAST AS FORCING ALOFT WEAKENS. WEAK SURFACE RIDGING WILL QUICKLY TRACK ACROSS THE REGION TUESDAY NIGHT BRINGING A BRIEF PERIOD OF CLEARING BEFORE CLOUDS INCREASE IN ADVANCE OF ANOTHER APPROACHING WAVE ALOFT FROM THE NORTHWEST. THE UPPER WAVE WILL SWING ACROSS THE LOWER GREAT LAKES WEDNESDAY WITH LIGHT SNOW SHOWERS IMPACTING PRIMARILY THE NORTHERN HALF OF THE FORECAST AREA. COULD SEE SOME VERY LIGHT ACCUMS NORTH OF I-70 FROM A DUSTING UP TO CLOSE TO AN INCH IN FAR NORTHERN COUNTIES BY LATE DAY WEDNESDAY. BUMPED UP TO CHANCE POPS IN THE NORTH WEDNESDAY. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE REESTABLISHES ALONG WITH A RENEWED SURGE OF COLDER AIR. TEMPS...DEFINITELY THE BIG STORY OF THE SHORT TERM. UNDERCUT MOS GUIDANCE FOR LOWS TONIGHT WITH SNOWCOVER AND 850MB TEMPS BOTTOMING OUT AT -21 TO -20C BY TUESDAY MORNING. THINK MOST LOCATIONS GET INTO THE SINGLE DIGITS. ONLY MODEST RECOVERY FOR TUESDAY AS HIGHS WILL END UP RIGHT AROUND 20. LEANED CLOSER TO COOLER END OF GUIDANCE THE REST OF THE WAY...WITH HIGHS RECOVERING INTO THE LOWER/MID 30S FOR WEDNESDAY. INDY RECORDS FOR TUESDAY...RECORD LOW IS 5 (1880) AND RECORD LOW MAX TEMP IS 20 (1880). POTENTIAL FOR THE FIRST SINGLE DIGIT LOW IN NOVEMBER SINCE 11/30/1976. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 331 AM EST MON NOV 17 2014 ENSEMBLES SUGGEST A DEEP UPPER TROUGH INITIALLY OVER THE EASTERN PARTS OF THE COUNTRY WILL BE LIFTING OFF TO THE NORTHEAST BY LATE IN THE WEEK...LEAVING A MORE ZONAL FLOW OVER THE LOCAL AREA. THE NEXT SYSTEM THAT MAY AFFECT THE AREA DURING THIS PERIOD WILL BE A DISTURBANCE OF PACIFIC ORIGIN. THERE IS STILL QUITE A BIT OF SPREAD AMONG THE ENSEMBLES AS TO THE TIMING OF THIS FEATURE...FROM AS EARLY AS FRIDAY NIGHT TO AS LATE AS SATURDAY NIGHT OR SUNDAY. FOR NOW...WILL BROADBRUSH POPS STARTING FRIDAY NIGHT THROUGH NEXT SUNDAY. THERE MAY STILL BE ENOUGH RESIDUAL COLD AIR AROUND FOR MIXED PRECIPITATION OVER PARTS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT...BUT ENSEMBLES SUGGEST LITTLE THREAT FOR SIGNIFICANT ACCUMULATIONS AT THIS TIME. && .AVIATION /DISCUSSION FOR THE 171200Z TAFS/... ISSUED AT 538 AM EST MON NOV 17 2014 BACK EDGE OF LOWER MVFR CEILINGS AROUND 012 CURRENTLY MOVING INTO THE WESTERN BORDER ZONES. EXTRAPOLATION AND SHORT TERM MODELS SUGGEST THESE LOWER CEILINGS WILL SCATTER OUT OVER THE TAF SITES BY 171400Z. LOW LEVEL LAPSE RATES BECOME NEAR DRY ADIABATIC BY EARLY AFTERNOON...SO EXPECTING VFR CEILINGS AROUND 040 TO DEVELOP BY THAT TIME...AS WELL AS SCATTERED SNOW SHOWERS. MODEL GUIDANCE SUGGESTS BRIEF IFR VISIBILITY RESTRICTIONS POSSIBLE IN THE HEAVIER SHOWERS...BUT DUE TO THE SCATTERED NATURE OF THE SHOWERS...WILL REFRAIN FROM AN EXPLICIT MENTION AT THIS TIME. SURFACE WINDS EXPECTED TO GRADUALLY INCREASE AS THE MORNING GOES BY...WITH GUSTS AROUND 25 KTS FROM 270-300 DEGREES EXPECTED BY THIS AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR INZ037>042-045>049-051>057-060>065-067>072. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....JAS AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
331 AM EST MON NOV 17 2014 .UPDATE... THE SYNOPSIS...NEAR TERM...SHORT TERM...LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 WIDESPREAD SNOW WILL END THIS MORNING WITH SCATTERED SNOW SHOWERS INTO THE EVENING AS MUCH COLDER AIR SPREADS INTO THE OHIO VALLEY. VERY COLD WEATHER WILL CONTINUE THROUGH MIDWEEK...WITH CHANCES FOR SNOW AGAIN ON WEDNESDAY AS A WEAK UPPER LEVEL WAVE PASSES THROUGH THE REGION. LOW PRESSURE TRACKING INTO THE REGION OVER THE WEEKEND WILL BRING A RETURN TO UNSETTLED WEATHER ALONG WITH WARMER TEMPERATURES. && .NEAR TERM /TODAY/... ISSUED AT 331 AM EST MON NOV 17 2014 STEADY SNOWFALL CONTINUES ALONG AND SOUTHEAST OF A TERRE HAUTE-INDY METRO-MUNCIE LINE AS OF 08Z. BACK EDGE OF THE PRECIP SHIELD HAS BACKPEDALED NORTHWEST OVER THE LAST 2-3 HOURS AS THE SHARP UPPER WAVE QUICKLY TRACKS INTO THE LOWER MISSISSIPPI VALLEY. TEMPS WERE GENERALLY IN THE 20S AND FALLING WITH THE INITIAL ARRIVAL OF THE ARCTIC AIRMASS. INITIAL ISSUE FOCUSES ON THE SNOW CONTINUING EARLY THIS MORNING WITH ITS DEPARTURE OFF TO THE EAST BETWEEN 12-15Z. DESPITE THE PIVOT BACK TO THE WEST OF THE PRECIP SHIELD...DO NOT EXPECT IT TO SHIFT MUCH FURTHER NORTHWEST FROM ITS CURRENT POSITION AS UPPER LEVEL ENERGY IS QUICKLY APPROACHING FROM THE SOUTHWEST WHILE THE MAIN SURFACE LOW TRACKS INTO NORTHERN GEORGIA. HRRR AND THE WRF BOTH HAVE A NICE HANDLE ON THE LOCATION OF THE SNOWFALL AND EXPECTED EVOLUTION THROUGH DAYBREAK. SNOW WILL BEGIN TO SHIFT EAST AFTER 09-10Z...WITH PRECIP ENDING OVER FAR EASTERN COUNTIES BY 14-15Z. WITH THE POTENTIAL FOR ANOTHER INCH OR TWO OF ADDITIONAL ACCUM OVER THE SOUTHEAST HALF OF THE FORECAST AREA...WILL CONTINUE WITH THE ADVISORY IN ITS CURRENT STATE THROUGH 14Z. HEAVIER SNOWFALL WILL REMAIN SOUTHEAST OF THE INDY METRO...BUT STILL QUITE POSSIBLE TO TACK ON ANOTHER HALF INCH OR SO IN THE CITY BEFORE SNOW ENDS. FURTHER NORTHWEST...EXPECT LITTLE MORE THAN FLURRIES OVER THE NEXT FEW HOURS. DRIER AIR WILL WRAP INTO THE REGION BEHIND THE SNOWFALL LATER THIS MORNING AND MAY EVEN BRING A FEW PEAKS OF SUNSHINE THROUGH MIDDAY. COLD POOL BEGINS TO SETTLE OVER THE REGION DURING THE AFTERNOON AS THE UPPER LOW PINWHEELS INTO THE NORTHERN GREAT LAKES. AS HAS BEEN DISCUSSED OVER THE LAST FEW DAYS...POTENTIAL FOR SCATTERED SNOW SHOWERS TO REDEVELOP THIS AFTERNOON AND EVENING. MODELS IN GENERAL TEND TO STRUGGLE IN THIS SETUP AND OFTEN UNDERDO THE SNOW POTENTIAL BECAUSE THEY DO NOT CAPTURE THE MESOSCALE FEATURES WELL. THE WRF DOES A BETTER JOB IN THIS REGARD AND NOW THAT WE ARE WITHIN ITS WINDOW...IT IS SUPPORTING POTENTIAL FOR SCATTERED CONVECTIVE SNOW SHOWERS/SQUALLS LATER THIS AFTERNOON...AND THESE COULD CAUSE SOME PROBLEMS OVER THE REGION. PLENTY OF MID LEVEL ENERGY ROTATING AROUND THE BASE OF THE UPPER LOW AND THROUGH THE REGION. THIS COMBINED WITH INTENSIFYING COLD ADVECTION AND SHALLOW INSTABILITY WITH STEEPENING LAPSE RATES TO 850MB SUPPORT CONVECTIVE SNOW SHOWERS. WITH WIND GUSTS STEADILY STRENGTHENING TO AROUND 30MPH THIS AFTERNOON...THESE SNOW SHOWERS/SQUALLS HAVE THE POTENTIAL TO CREATE A GREATER IMPACT ON TRAVEL THAN THE SNOW EXPERIENCED SUNDAY NIGHT AND EARLY THIS MORNING. WHILE SNOWFALL WILL BE ONLY A DUSTING TO A FEW TENTHS OF AN INCH AT BEST...THE SNOW WILL BE DRIER AND MUCH EASIER TO BLOW AROUND WITH THE POTENTIAL FOR LOCALLY REDUCED VISIBILITIES IN HEAVIER SNOW SHOWERS. AS CRAZY AS THIS SOUNDS...HAVE A GROWING CONCERN THAT THE LATE AFTERNOON/EVENING RUSH HOUR COULD BE MORE GREATLY IMPACTED THAN THIS MORNING. WILL BE INTRODUCING AN SPS TO HIGHLIGHT THESE THREATS FOR LATER TODAY. TEMPS...HIGHS ARE TRICKY FOR TODAY CONSIDERING THEY ARE LARGELY LOWER THAN CURRENT READINGS THIS MORNING. MAY SEE A BRIEF RISE IN TEMPS THROUGH MIDDAY WITH FALLING TEMPS THEREAFTER AS THE STRONGER COLD ADVECTION ARRIVES. A MOS BLEND WAS REASONABLE FOR HIGHS...THEN USED A MIX OF NAM/LAMP DATA FOR THE FALLING TEMPS THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 331 AM EST MON NOV 17 2014 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AND SNOW CHANCES...PRIMARILY WEDNESDAY. AN EVEN STRONGER BLAST OF COLD AIR OF POLAR ORIGIN POISED TO OVERSPREAD THE OHIO VALLEY AND GREAT LAKES FOR MOST OF THE SHORT TERM. AFOREMENTIONED SCATTERED SNOW SHOWERS WILL BE ONGOING THIS EVENING...LIKELY NOT DIMINISHING IN INTENSITY AND COVERAGE UNTIL CLOSER TO MIDNIGHT. WILL MAINTAIN SCATTERED FLURRIES OVERNIGHT WITH STILL PLENTY OF FORCING ALOFT AND WILL HAVE TO MONITOR AS COULD EVEN SEE A FEW SNOW SHOWERS LINGER WELL INTO THE OVERNIGHT. UPPER TROUGH AND COLD POOL ALOFT CENTERED OVER THE REGION EARLY TUESDAY...GRADUALLY LIFTING OUT BY LATE TUESDAY AS THE UPPER LOW SHIFTS EAST INTO QUEBEC. WILL MAINTAIN A MENTION OF SCATTERED FLURRIES INTO THE AFTERNOON...ENDING FROM WEST TO EAST AS FORCING ALOFT WEAKENS. WEAK SURFACE RIDGING WILL QUICKLY TRACK ACROSS THE REGION TUESDAY NIGHT BRINGING A BRIEF PERIOD OF CLEARING BEFORE CLOUDS INCREASE IN ADVANCE OF ANOTHER APPROACHING WAVE ALOFT FROM THE NORTHWEST. THE UPPER WAVE WILL SWING ACROSS THE LOWER GREAT LAKES WEDNESDAY WITH LIGHT SNOW SHOWERS IMPACTING PRIMARILY THE NORTHERN HALF OF THE FORECAST AREA. COULD SEE SOME VERY LIGHT ACCUMS NORTH OF I-70 FROM A DUSTING UP TO CLOSE TO AN INCH IN FAR NORTHERN COUNTIES BY LATE DAY WEDNESDAY. BUMPED UP TO CHANCE POPS IN THE NORTH WEDNESDAY. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE REESTABLISHES ALONG WITH A RENEWED SURGE OF COLDER AIR. TEMPS...DEFINITELY THE BIG STORY OF THE SHORT TERM. UNDERCUT MOS GUIDANCE FOR LOWS TONIGHT WITH SNOWCOVER AND 850MB TEMPS BOTTOMING OUT AT -21 TO -20C BY TUESDAY MORNING. THINK MOST LOCATIONS GET INTO THE SINGLE DIGITS. ONLY MODEST RECOVERY FOR TUESDAY AS HIGHS WILL END UP RIGHT AROUND 20. LEANED CLOSER TO COOLER END OF GUIDANCE THE REST OF THE WAY...WITH HIGHS RECOVERING INTO THE LOWER/MID 30S FOR WEDNESDAY. INDY RECORDS FOR TUESDAY...RECORD LOW IS 5 (1880) AND RECORD LOW MAX TEMP IS 20 (1880). POTENTIAL FOR THE FIRST SINGLE DIGIT LOW IN NOVEMBER SINCE 11/30/1976. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 331 AM EST MON NOV 17 2014 ENSEMBLES SUGGEST A DEEP UPPER TROUGH INITIALLY OVER THE EASTERN PARTS OF THE COUNTRY WILL BE LIFTING OFF TO THE NORTHEAST BY LATE IN THE WEEK...LEAVING A MORE ZONAL FLOW OVER THE LOCAL AREA. THE NEXT SYSTEM THAT MAY AFFECT THE AREA DURING THIS PERIOD WILL BE A DISTURBANCE OF PACIFIC ORIGIN. THERE IS STILL QUITE A BIT OF SPREAD AMONG THE ENSEMBLES AS TO THE TIMING OF THIS FEATURE...FROM AS EARLY AS FRIDAY NIGHT TO AS LATE AS SATURDAY NIGHT OR SUNDAY. FOR NOW...WILL BROADBRUSH POPS STARTING FRIDAY NIGHT THROUGH NEXT SUNDAY. THERE MAY STILL BE ENOUGH RESIDUAL COLD AIR AROUND FOR MIXED PRECIPITATION OVER PARTS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT...BUT ENSEMBLES SUGGEST LITTLE THREAT FOR SIGNIFICANT ACCUMULATIONS AT THIS TIME. && .AVIATION /DISCUSSION FOR THE 170900Z TAF UPDATE/... ISSUED AT 331 AM EST MON NOV 17 2014 NORTHWEST EDGE OF SNOW SHIELD JUST SCRAPING THE KIND VICINITY. EXPECTING THE SNOW TO END AT KIND OVER THE NEXT HOUR. OTHERWISE...IFR CEILINGS LIFTING INTO AN MVFR DECK AROUND 012-015 OVER THE WESTERN PARTS OF THE STATE AT THIS TIME...SO EXPECTING CEILINGS TO RISE ABOVE IFR IN THE NEXT FEW HOURS. PREVIOUS DISCUSSION FOLLOWS. SNOW HAS ENDED AT KLAF AND AND KHUF...AND IS MAINLY CONFINED TO KIND AND KBMG AT THIS TIME. CONDITIONS HAVE ALREADY IMPROVED TO MVFR CATEGORY AT KHUF...BUT IFR CEILINGS WILL LINGER AT KLAF A BIT LONGER. ELSEWHERE...MVFR CONDITIONS SHOULD RETURN TO KIND AND KBMG AFTER MON 08Z WHEN SNOW INTENSITY WEAKENS. HOWEVER...DID HOLD ONTO MENTION OF LIGHT SNOW SHOWERS THROUGH DAYBREAK AT THOSE 2 SITES WHICH ARE CLOSER TO THE NEXT WAVE. VFR CONDITIONS SHOULD BE THE PREVAILING FLIGHT CATEGORY BY MON 14Z AT ALL TAF SITES. HOWEVER...STRONG WEST WINDS WILL THEN BECOME AN ISSUE...BLOWING SNOW AROUND. SUSTAINED SPEEDS WILL RANGE BETWEEN 12 TO 15 KTS WITH GUSTS UP TO 25 KTS THROUGH THE END OF TAF PERIOD AT KLAF/KIND/KHUF. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR INZ037>042-045>049-051>057-060>065-067>072. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....JAS AVIATION...TDUD/JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1108 PM CST Sun Nov 16 2014 .UPDATE... Issued at 1105 PM CST SUN NOV 16 2014 Updated Aviation discussion for 06Z TAF Issuance. UPDATE Issued at 937 CST SUN NOV 16 2014 Making some minor adjustments to snow totals, but overall the package looks good. The heaviest precipitation band has set up from Stoddard county in SEMO to the northwest half of McCracken towards Henderson county to Spencer county. This has pretty much been the story so far this evening. The HRRR model depicts things pretty well and we expect that heavier band to stay in place through about midnight, then the band should actually shift to the north a bit as the main short wave gets closer. This band then slides southeast through the early morning hours. Already had some 2+ inch amounts along the Wabash/Ohio River areas and once the temperature drops to 32 the accumulations start. The 32 degree line essentially runs from EVV to PAH and is slowly moving southeast. && .SHORT TERM...(Tonight through Tuesday night) Issued at 134 PM CST SUN NOV 16 2014 Confidence in increasing that there will be a fairly significant snow event along the Ohio River and back into extreme southeast Missouri. 12z GFS, in particular has honed in on a precip max along that axis for several runs now, and thermal profiles suggest that axis will likely correspond to where the initial snow/mix line will set up early this evening. Expecting very close to .40 inches liquid QPF, so will increase snow projections into the 3-5 inch range. Have already upgraded to warning headlines along the Ohio River for tonight. See no need for further adjustments at this time. Still looking for all snow northwest of the warning area, but QPF will likely not be quite as high. Will need to monitor though, because have already heard of at least one report of 3.5 inches out to our west in the SGF CWA. Will stick with the advisory in our nw half for the time being. Still lots of uncertainties concerning precip type and the timing of the transition from rain/sleet over to snow, most likely around or after the midnight time frame far southeast locations. Believe there will still be enough moisture left after the transition over to snow later tonight for an inch or so to accumulate before the precip comes to an end around dawn Monday. Thus, will continue with the Winter Weather Advisory for the rest of the CWA surrounding the warning area. Next big story lies with the bitterly cold Arctic air that will follow early in the week. Blustery winds gusting over 20 mph on Monday may cause some blowing or drifting of any snow that is on the ground and hold daytime temps nearly steady in the 20s. Will then challenge record low temps Monday night as reading fall down into the 10 to 15 degree range. Wind chill values could be near zero by the time many awake and head out on Tuesday. .LONG TERM...(Wednesday through Sunday) Issued at 320 PM CST SUN NOV 16 2014 Surface high pressure over the southeast U.S. will keep our region dry Tuesday night into Wednesday, and a return of south to southwest winds will help temperatures moderate a little from the very cold temperatures early in the work week. Models continue to show a weak dry cold front moving across the middle Mississippi and lower Ohio valleys Wednesday into Wednesday night. This will bring another shot of colder air, with highs Thursday and Friday again dropping back a couple to several degrees. For Thursday night and beyond, models continue to be all over the place. GFS brings in a shot of precip late Thursday into Thursday night, then another shot Saturday and through the weekend. ECMWF bring precip into the area late Friday and continues through the weekend. GEM keeps us dry through 12z Saturday, but does match up well to the GFS at that time. Went ahead and kept some small PoPs in across much of the PAH forecast area Thursday night for some light snow. By Saturday, when models seems to be lining up, went with slight chance pops for Saturday for most of the PAH fa, with increasing chances Saturday night into Sunday. Fortunately, it looks like temperatures will be warm enough that it will just be rain through the weekend. High by Sunday will only be a few degrees below normal. && .AVIATION... Issued at 1105 PM CST SUN NOV 16 2014 All terminals should have changed over to snow by press time, as the 32 line likewise makes its passage soon thereafter. IFR cigs and vsbys accompany bands of moderate snow, while low end MVFR cigs and vsbys prevail through the course of the night. The system lifts out early, with improvement to VFR conditions anticipated during the daylight hours, although cigs may maintain in the northeast (KEVV/KOWB). Winds will stiffen and become gusty during the pm hours. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...WINTER STORM WARNING until 6 AM CST Monday FOR ILZ087-089>094. WINTER WEATHER ADVISORY until 6 AM CST Monday FOR ILZ075>078- 080>086-088. MO...WINTER STORM WARNING until 6 AM CST Monday FOR MOZ110>112-114. WINTER WEATHER ADVISORY until 6 AM CST Monday FOR MOZ076-086-087- 100-107>109. IN...WINTER STORM WARNING until 6 AM CST Monday FOR INZ085>088. WINTER WEATHER ADVISORY until 6 AM CST Monday FOR INZ081-082. KY...WINTER STORM WARNING until 6 AM CST Monday FOR KYZ003>005-007- 010-014-015-018-019. WINTER WEATHER ADVISORY until 6 AM CST Monday FOR KYZ001-002-006- 008-009-011>013-016-017-020>022. && $$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1151 PM EST Sun Nov 16 2014 ...Updated Aviation Discussion... ...Forecast Update... Issued at 1110 PM EST Nov 16 2014 Will be issuing an update to the Winter headline product soon, just to freshen up the wording, not change any of the main points. Have a pretty solid band of snow headed towards our northern forecast area with more mixy precip still occurring on the south side of the band. KOWB still is reporting rain even at 33 degrees, and KSDF has been fluctuating between -RA, -RASN, and -RAPL, indicative of that warm layer aloft, which should finally start pushing steadily south a few hours after Midnight. With the approach of the shortwave over Oklahoma still expecting an increase in radar coverage overnight, which should hit most of the advisory area. The southern edge will continue to run low on totals given the warm initial ground cover as well as the antecedent rains. Issued at 840 PM EST Nov 16 2014 Had another ACARS soundings showing a thinner warm layer aloft, but still enough to melt the ice and then allow for some re-freezing, as we have been getting a few more sleet reports. Observations deeper into the cold over southern Indiana are showing all snow. Latest water vapor loop shows the area of enhanced lift associated with the right rear quadrant of an upper jet to our north. A potent shortwave, now over Oklahoma, will merge with a longer wave trough dropping down over the Central Plains to enhance precip further overnight. The warm nose may briefly re-exert it`s influence northward over the next few hours before the cold air smashes through here late tonight. The timing mentioned in our web briefings still looks reasonable as well as the totals. Will add in better chances for sleet, but overall this package is not a big change. Issued at 620 PM EST Nov 16 2014 Had some good ACARS soundings in an hour or two ago, and basically matched these up with the latest RUC temps aloft. Have used this model for the next few hours to generate the transition zone for rain to rain/snow mix to all snow. These changes did not change the overall snow totals significantly, so no need to change the advisory/warning area at this point. Will continue to monitor multiple sources and adjust the forecast as needed through the evening hours. .SHORT TERM (Now through Monday Night)... Issued at 340 PM EST Sun Nov 16 2014 ...Accumulating Snows Likely Tonight into Monday... Overview -------- The short term period will feature a broad trough across much of the CONUS. A strong PV anomaly is currently getting ready to enter the southern Plains and will quickly slide east toward the mid Mississipi Valley toward dawn. Ahead of this feature, surface cyclogenesis is already occurring over the lower Mississippi. This system will quickly lift NE and deepen as it slides by to our east on Monday. Moisture is already spreading north into the region, and will continue into tonight ahead of these slowly phasing systems. This deep moisture will interact with increasingly colder temperature profiles and produce a period of wintery weather across the Ohio Valley. Model Preference ---------------- There has been a wide model discrepancy with respect to thermal profiles below 700 mb leading up to this event, overall leading to low confidence. We did get a trend toward some better agreement with the 12z runs, so decided to blend mainly between the 12z NAM/GFS temperature profiles. Do think the outcome of this event ultimately hinges more on the lower mid levels than nearer the surface, however did want to mention that surface temperatures are expected to hover around or just above freezing until the heavier snow falls toward dawn. Sensible Weather and Impacts ---------------------------- Current radar does show the two separate storm systems nicely with light rain over southern KY and mainly light snow overspreading central IL/IN. We`ll watch through the evening hours as deeper moisture slowly invades the area, however expect only light precipitation and no real impacts initially. Southern Indiana could see light accumulations as early as around sunset. Precipitation will likely mix at times even across our north as temp profiles fluctuate under varying degrees of saturation. Really not expecting the main show to get going until we approach Midnight as system becomes more organized, column becomes more saturated, and surface temps wet bulb down toward more wintery precip conducive numbers. A frontogenetically forced band of snow will then ride SW to NE across our Warning area, pivoting to a more SSW to NNE orientation through the night as the right entrance region of an upper level jet slides overhead. This pivoting should actually enhance the frontogenesis as well as keep the warm nose near the Ohio River. Thereafter, the approaching PV anomaly begins to rapidly push the system east with cold air crashing in in the low to mid levels. The surface low will strengthen as it slides just to our east, providing more deep moisture to interact with the cold air. Since the warm layer aloft is going to drive this event, will characterize how the overnight progresses by describing its evolution through several geographic areas. Southern Indiana (Winter Storm Warning 3-5" of Snow) ---------------------------------------------------- This area is expected to stay below freezing through the thermal column, so all snow is expected other than a brief mix at onset. This is expected to yield 3-5 inches by Monday morning, with the heaviest snow falling between Midnight and 7 AM EST. Impacts to roads and travel are expected. Right Along the Ohio River (Winter Weather Advisory 2-3" Snow) -------------------------------------------------------------- This area is the northern portion of the battleground between the warm nose aloft. Expect to see mainly snow, however a few brief periods of wintery mix including some sleet should cut down on totals a bit. Expect all snow around and after Midnight EST. Just South of the Ohio River (Winter Weather Advisory 1-3" Snow and a mix) ------------------------------------------------------------------- This area will be more see more of the warm air aloft for a longer time and should cut down on snow totals. Could also see more bouts of sleet with no impact. The city of Louisville will be right underneath this battleground, so bust potential is high in this transition zone. Much will depend on how quick the changeover occurs. Expect change over between 1 and 4 AM EST. Bluegrass Region North of I-64 (Winter Weather Advisory 2-4" Snow) ------------------------------------------------------------------ Mostly rain before 4 AM EST. An enhanced area of snow after 4 AM EST, where deeper moisture mentioned above will be present as two storm systems phase. South Central Kentucky (Impact Based Winter Weather Advisory 1" or less and a brief mix) ----------------------------------------------------------------- Transition time and the amount of deep moisture left are in question in this area, as well as rainfall`s effect on ability to accumulate. Nevertheless, a quick shot of snow around the morning commute, and the first snow of the year is enough to warrant the advisory. .LONG TERM (Tuesday through Sunday)... Issued at 335 PM EST Sun Nov 16 2014 Forecast thoughts in the long term period have not changed much for this forecast issuance as most of the forecasting focus was on the Winter Storm Warning/Advisories in the short term period. See the following excerpts from the previous discussion with a few added thoughts below. Deep upper troffing digging from eastern Canada into the United States, with occasional small reinforcing shots moving through the flow, will keep us cold for much of the work week, with any appreciable moderation in temperatures holding off until the weekend and into next week. Most moisture associated with the upper trof will stay bottled up to our north, so though it will be cold, it will also be mostly on the drier side (not necessarily *completely* dry), with some moisture return possible next weekend. The models are a mess in the long term, especially Thursday through Sunday. Models are having difficulty with various shortwaves diving south across the Plains in an a broad digging upper level trough. These shortwaves will eventually bring us precip during the latter half of the week but when, how much, and what type all remain in question. The main story Tuesday through Wednesday will be the cold. Tuesday night we will drop well into the teens. Depending on the location and depth of any snowpack from tonight`s snowfall, a reading or two in the single digits may not be out of the question in sheltered areas from southeast Indiana into the northern Blue Grass. High temperatures on Tuesday will only be in the lower and middle 20s, which is about 30 degrees colder than normal! Wednesday we may be able to moderate up to around 40 in southwest low level flow between high pressure over Dixie and a cold front crossing the Great Lakes, but that will be offset by winds gusting to 25 mph and afternoon wind chills mostly in the 20s. As mentioned earlier, Thursday through Sunday are tough to figure out right now. Will lean toward the drier side of the forecast envelope and keep PoPs small for now. Will bring MaxT`s well up into the 40s by Saturday with the anticipated pattern change. && .AVIATION (06Z TAF Update)... Updated at 1150 PM EST Sun Nov 16 2014 Winter conditions are on their way for the sites tonight. Have had some sleet mixed in with rain at SDF, and this threat will push east. Cigs have dropped to LIFR or worse and we should stay that way for most if not all the overnight period. Expect a transition over to all snow, first between now and roughly 07Z at KSDF and later at the other two sites. Vsby will be worse once it goes over to all snow, but have LIFR conditions persisting through mid morning, when snow will start to exit off to the east and cigs will rise slowly. Cannot rule out additional snow showers through the afternoon and evening, as soundings don`t show much moisture, but that moisture is in the ice crystal growth zone and there is some instability as well. Winds will pick up from the west through the day tomorrow as the cold air behind this system rushes in. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...WINTER STORM WARNING until Noon EST /11 AM CST/ Monday FOR KYZ023-032. WINTER WEATHER ADVISORY from 3 AM EST /2 AM CST/ to Noon EST /11 AM CST/ Monday FOR KYZ027-036-037-039>043-045>049-053>057- 061>065-070>072. WINTER WEATHER ADVISORY until Noon EST /11 AM CST/ Monday FOR KYZ024>026-028>031-033>035-038. IN...WINTER STORM WARNING until Noon EST /11 AM CST/ Monday FOR INZ076>079-083-084-089>092. && $$ Update.........RJS Short Term.....BJS Long Term......AMS Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1112 PM EST Sun Nov 16 2014 ...Forecast Update... Issued at 1110 PM EST Nov 16 2014 Will be issuing an update to the Winter headline product soon, just to freshen up the wording, not change any of the main points. Have a pretty solid band of snow headed towards our northern forecast area with more mixy precip still occurring on the south side of the band. KOWB still is reporting rain even at 33 degrees, and KSDF has been fluctuating between -RA, -RASN, and -RAPL, indicative of that warm layer aloft, which should finally start pushing steadily south a few hours after Midnight. With the approach of the shortwave over Oklahoma still expecting an increase in radar coverage overnight, which should hit most of the advisory area. The southern edge will continue to run low on totals given the warm initial ground cover as well as the antecedent rains. Issued at 840 PM EST Nov 16 2014 Had another ACARS soundings showing a thinner warm layer aloft, but still enough to melt the ice and then allow for some re-freezing, as we have been getting a few more sleet reports. Observations deeper into the cold over southern Indiana are showing all snow. Latest water vapor loop shows the area of enhanced lift associated with the right rear quadrant of an upper jet to our north. A potent shortwave, now over Oklahoma, will merge with a longer wave trough dropping down over the Central Plains to enhance precip further overnight. The warm nose may briefly re-exert it`s influence northward over the next few hours before the cold air smashes through here late tonight. The timing mentioned in our web briefings still looks reasonable as well as the totals. Will add in better chances for sleet, but overall this package is not a big change. Issued at 620 PM EST Nov 16 2014 Had some good ACARS soundings in an hour or two ago, and basically matched these up with the latest RUC temps aloft. Have used this model for the next few hours to generate the transition zone for rain to rain/snow mix to all snow. These changes did not change the overall snow totals significantly, so no need to change the advisory/warning area at this point. Will continue to monitor multiple sources and adjust the forecast as needed through the evening hours. .SHORT TERM (Now through Monday Night)... Issued at 340 PM EST Sun Nov 16 2014 ...Accumulating Snows Likely Tonight into Monday... Overview -------- The short term period will feature a broad trough across much of the CONUS. A strong PV anomaly is currently getting ready to enter the southern Plains and will quickly slide east toward the mid Mississipi Valley toward dawn. Ahead of this feature, surface cyclogenesis is already occurring over the lower Mississippi. This system will quickly lift NE and deepen as it slides by to our east on Monday. Moisture is already spreading north into the region, and will continue into tonight ahead of these slowly phasing systems. This deep moisture will interact with increasingly colder temperature profiles and produce a period of wintery weather across the Ohio Valley. Model Preference ---------------- There has been a wide model discrepancy with respect to thermal profiles below 700 mb leading up to this event, overall leading to low confidence. We did get a trend toward some better agreement with the 12z runs, so decided to blend mainly between the 12z NAM/GFS temperature profiles. Do think the outcome of this event ultimately hinges more on the lower mid levels than nearer the surface, however did want to mention that surface temperatures are expected to hover around or just above freezing until the heavier snow falls toward dawn. Sensible Weather and Impacts ---------------------------- Current radar does show the two separate storm systems nicely with light rain over southern KY and mainly light snow overspreading central IL/IN. We`ll watch through the evening hours as deeper moisture slowly invades the area, however expect only light precipitation and no real impacts initially. Southern Indiana could see light accumulations as early as around sunset. Precipitation will likely mix at times even across our north as temp profiles fluctuate under varying degrees of saturation. Really not expecting the main show to get going until we approach Midnight as system becomes more organized, column becomes more saturated, and surface temps wet bulb down toward more wintery precip conducive numbers. A frontogenetically forced band of snow will then ride SW to NE across our Warning area, pivoting to a more SSW to NNE orientation through the night as the right entrance region of an upper level jet slides overhead. This pivoting should actually enhance the frontogenesis as well as keep the warm nose near the Ohio River. Thereafter, the approaching PV anomaly begins to rapidly push the system east with cold air crashing in in the low to mid levels. The surface low will strengthen as it slides just to our east, providing more deep moisture to interact with the cold air. Since the warm layer aloft is going to drive this event, will characterize how the overnight progresses by describing its evolution through several geographic areas. Southern Indiana (Winter Storm Warning 3-5" of Snow) ---------------------------------------------------- This area is expected to stay below freezing through the thermal column, so all snow is expected other than a brief mix at onset. This is expected to yield 3-5 inches by Monday morning, with the heaviest snow falling between Midnight and 7 AM EST. Impacts to roads and travel are expected. Right Along the Ohio River (Winter Weather Advisory 2-3" Snow) -------------------------------------------------------------- This area is the northern portion of the battleground between the warm nose aloft. Expect to see mainly snow, however a few brief periods of wintery mix including some sleet should cut down on totals a bit. Expect all snow around and after Midnight EST. Just South of the Ohio River (Winter Weather Advisory 1-3" Snow and a mix) ------------------------------------------------------------------- This area will be more see more of the warm air aloft for a longer time and should cut down on snow totals. Could also see more bouts of sleet with no impact. The city of Louisville will be right underneath this battleground, so bust potential is high in this transition zone. Much will depend on how quick the changeover occurs. Expect change over between 1 and 4 AM EST. Bluegrass Region North of I-64 (Winter Weather Advisory 2-4" Snow) ------------------------------------------------------------------ Mostly rain before 4 AM EST. An enhanced area of snow after 4 AM EST, where deeper moisture mentioned above will be present as two storm systems phase. South Central Kentucky (Impact Based Winter Weather Advisory 1" or less and a brief mix) ----------------------------------------------------------------- Transition time and the amount of deep moisture left are in question in this area, as well as rainfall`s effect on ability to accumulate. Nevertheless, a quick shot of snow around the morning commute, and the first snow of the year is enough to warrant the advisory. .LONG TERM (Tuesday through Sunday)... Issued at 335 PM EST Sun Nov 16 2014 Forecast thoughts in the long term period have not changed much for this forecast issuance as most of the forecasting focus was on the Winter Storm Warning/Advisories in the short term period. See the following excerpts from the previous discussion with a few added thoughts below. Deep upper troffing digging from eastern Canada into the United States, with occasional small reinforcing shots moving through the flow, will keep us cold for much of the work week, with any appreciable moderation in temperatures holding off until the weekend and into next week. Most moisture associated with the upper trof will stay bottled up to our north, so though it will be cold, it will also be mostly on the drier side (not necessarily *completely* dry), with some moisture return possible next weekend. The models are a mess in the long term, especially Thursday through Sunday. Models are having difficulty with various shortwaves diving south across the Plains in an a broad digging upper level trough. These shortwaves will eventually bring us precip during the latter half of the week but when, how much, and what type all remain in question. The main story Tuesday through Wednesday will be the cold. Tuesday night we will drop well into the teens. Depending on the location and depth of any snowpack from tonight`s snowfall, a reading or two in the single digits may not be out of the question in sheltered areas from southeast Indiana into the northern Blue Grass. High temperatures on Tuesday will only be in the lower and middle 20s, which is about 30 degrees colder than normal! Wednesday we may be able to moderate up to around 40 in southwest low level flow between high pressure over Dixie and a cold front crossing the Great Lakes, but that will be offset by winds gusting to 25 mph and afternoon wind chills mostly in the 20s. As mentioned earlier, Thursday through Sunday are tough to figure out right now. Will lean toward the drier side of the forecast envelope and keep PoPs small for now. Will bring MaxT`s well up into the 40s by Saturday with the anticipated pattern change. && .AVIATION (00Z TAF Update)... Updated at 620 PM EST Sun Nov 16 2014 Winter conditions are on their way for the sites tonight. Cigs will drop to LIFR or worse for most if not all the overnight period. Rain ongoing now will transition over to snow, first between 04 and 07Z at KSDF and later at the other two sites. Vsby will be worse once it goes over to all snow, but have LIFR conditions persiste through mid morning, when snow will start to exit off to the east and cigs will rise slowly. Cannot rule out additional snow showers through the afternoon and evening, as soundings don`t show much moisture, but that moisture is in the ice crystal growth zone and there is some instability as well. Winds will pick up from the west and northwest through the day tomorrow as the cold air behind this system rushes in. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...WINTER STORM WARNING until Noon EST /11 AM CST/ Monday FOR KYZ023-032. WINTER WEATHER ADVISORY from 3 AM EST /2 AM CST/ to Noon EST /11 AM CST/ Monday FOR KYZ027-036-037-039>043-045>049-053>057- 061>065-070>072. WINTER WEATHER ADVISORY until Noon EST /11 AM CST/ Monday FOR KYZ024>026-028>031-033>035-038. IN...WINTER STORM WARNING until Noon EST /11 AM CST/ Monday FOR INZ076>079-083-084-089>092. && $$ Update.........RJS Short Term.....BJS Long Term......AMS Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1137 PM CST SUN NOV 16 2014 .AVIATION... SECOND FRONT EXTENDS FROM RAPIDES SOUTH TO CAMERON PARISH THEN OUT INTO THE GULF. CLOUDS EXTEND BACK INTO CENTRAL TEXAS AS NW WINDS HAVE PICKED UP OVER THE REGION. LOW CLOUDS LOOK TO EXIT DRG THE OVERNIGHT HOURS WHILE MID DECK HANGS ON THRU SUNRISE BEFORE BEGINNING TO BREAK. LFT AND ARA WILL SEE MORE SHWRS IN THE NEXT SEVERAL HOURS BEFORE THEY EXIT INTO EASTERN LOUISIANA. && .PREV DISCUSSION... /ISSUED 1021 PM CST SUN NOV 16 2014/ UPDATE...ZONES AND GRIDS UPDATED TO REFLECT WIND ADVISORY. BEAUMONT IS JUST NOW APPROACHING WIND ADVISORY CRITERIA. THE SECONDARY FRONTAL BAND EXTENDS FROM BEAUMONT TO DERIDDER AND ALEXANDRIA. THIS BAND IS MOVING SOUTHEAST AT AROUND 25 MPH. GUSTS TO 35 MPH APPEAR POSSIBLE. SWEENEY PREV DISCUSSION... /ISSUED 937 PM CST SUN NOV 16 2014/ UPDATE...MADE MINOR ADJUSTMENT TO THE SURFACE WINDS WITH SLIGHTLY STRONGER WINDS OVERNIGHT WITH THE REINFORCING COLD FRONT CURRENTLY MOVING THROUGH SOUTHEAST TEXAS AND CENTRAL LOUISIANA. BLENDED IN LATEST RUC TEMP DATA AND DEW POINT TRENDS AS WELL AS ACCOUNTING FOR A SLOWER MOVEMENT OF THE COLD FRONT THROUGH ACADIANA TO ADJUST OVERNIGHT TEMPERATURES. STILL QUITE A DROP EXPECTED BUT NOW EXPECTING MID 40S FOR SW LA AND UPPER 40S FOR S CEN LA BY SUNRISE DUE LARGELY TO THE INCREASING WINDS. THESE CHANGES WILL BE REFLECTED IN ANOTHER ZONE UPDATE OUT SHORTLY. SWEENEY PREV DISCUSSION... /ISSUED 832 PM CST SUN NOV 16 2014/ UPDATE...WENT AHEAD AND CANCELLED THE TOR WATCH A COUPLE OF HOURS EARLY. WAS IN THE PROCESS OF TRIMMING BACK HOWEVER THE WINDS AND LIFT BOTH APPEAR TO HAVE WEAKEN AROUND THE FRONTAL BAND. ZONE UPDATE TO FOLLOW. SWEENEY PREV DISCUSSION... /ISSUED 553 PM CST SUN NOV 16 2014/ AVIATION... STRONG THUNDERSTORMS ARE RUMBLING THRU SOUTH CENTRAL LA AND WILL BE AN OPERATIONAL ISSUE FOR ARA AND LFT OVER THE NEXT HOUR OR SO. OTHERWISE LOW CEILINGS WITH PERIODS OF RAINS AND FOG WILL KEEP VSBY DOWN AT TIMES. CONDITIONS WILL IMPROVE AS A SECOND FRONT MOVES THROUGH LATE TONIGHT WITH WINDS PICKING UP. PREV DISCUSSION... /ISSUED 344 PM CST SUN NOV 16 2014/ DISCUSSION... BUSY WEATHER SITUATION ACROSS THE FORECAST AREA...WITH CONDITIONS VARYING FROM SPRING TO WINTER WITH SOME 25F DEGREE AIR TEMPERATURE BETWEEN THE NORTHWEST PORTION OF THE FORECAST AREA WITH THE SOUTHEAST. OLD FRONTAL BOUNDARY IS BISECTING THE FORECAST AREA WITH A SURFACE LOW/FRONTAL WAVE LOCATED AS OF 16/21Z BETWEEN JENNINGS AND LAFAYETTE. WARM SECTOR ON THE EAST SIDE OF THE LOW EXTENDS FROM EASTERN ST. LANDRY PARISH NEAR THE ATCHAFALAYA BASIN TO INTO THE GULF WATERS AROUND THE CAMERON/VERMILION PARISH BORDER. SOME STRONG LOW LEVEL INFLOW WITH A VERY WARM AND MOIST ENVIRONMENT IS LEADING TO THE DEVELOPMENT OF SHOWERS WITH SOME EMBEDDED STRONG THUNDERSTORMS IN THE WARM SECTOR. THERE IS A CHANCE OF SOME ROTATING CELLS BECOMING SURFACE BASED IN THE WARM SECTOR...AND THEREFORE...SPC HAS ISSUED A TORNADO WATCH FOR SOUTH CENTRAL LOUISIANA THROUGH 10 PM...ALTHOUGH THE THREAT SHOULD DIMINISH FOR PORTIONS OF THE AREA BEFORE THEN...AS THE LOW CONTINUES TO MOVE TO THE NORTHEAST AND LOSS OF DAYTIME HEATING DECREASES THE LOW LEVEL INSTABILITY. ANOTHER STRONG COLD FRONT WITH ARCTIC ORIGINS IS CURRENTLY MOVING SOUTHEAST ACROSS NORTHEAST TEXAS AND NORTHWEST LOUISIANA. THIS SYSTEM WILL MOVE INTO THE FORECAST AREA THIS EVENING AND INTO THE COASTAL WATERS DURING THE OVERNIGHT. SHOWERS WILL DECREASE BEHIND THIS FRONT AS MUCH DRIER AIR BEGINS TO MOVE IN...ALONG WITH BLUSTERY CONDITIONS. COLD AIR ADVECTION WILL CONTINUE ON MONDAY...AS THE STRONG HIGH PRESSURE SYSTEM BUILDS DOWN FROM THE NORTH. CLEAR SKIES ARE EXPECTED ON MONDAY NIGHT INTO TUESDAY MORNING...WITH A DECREASE IN WINDS EXPECTED. THEREFORE...A VERY COLD NIGHT IS EXPECTED WITH A FREEZE FOR A MAJORITY OF THE FORECAST AREA...AND HARD FREEZE CONDITIONS GETTING DOWN CLOSE TO I-10. CONDITIONS WILL BEGIN TO MODERATE BY MID-WEEK AS THE HIGH MOVES OFF TO THE EAST...AND RETURN FLOW OFF THE GULF COMMENCES. ENOUGH MOISTURE BUILD-UP BY THURSDAY INTO THE WEEKEND...TO INCLUDE A CHANCE FOR SHOWERS AND STORMS AS A SERIES OF UPPER LEVEL DISTURBANCES MOVE ACROSS. RUA MARINE... A SURFACE LOW/FRONTAL WAVE WILL MOVE ACROSS SOUTH CENTRAL LOUISIANA THIS EVENING...THEN SOUTHEAST LOUISIANA TONIGHT. MODERATE SOUTHERLY WINDS AND INSTABILITY WILL BRING ABOUT SHOWERS AND STORMS...ESPECIALLY EAST OF CAMERON DURING THE EVENING HOURS. SOME OF THESE STORMS WILL PRODUCE FREQUENT LIGHTNING...STRONG WINDS...AND EVEN AN ISOLATED WATER SPOUT CAN NOT BE RULED OUT. A STRONG COLD FRONT...WILL THEN MOVE ACROSS THE COASTAL WATERS LATER TONIGHT...REACHING THE WESTERN PORTIONS OF THE COASTAL WATERS DURING THE LATE EVENING HOURS...AND THEN ACROSS THE REMAINDER OF THE COASTAL WATERS AFTER MIDNIGHT. AIR FROM THE POLAR REGION WILL BE BEHIND THIS FRONT. THE DEVELOPING PRESSURE GRADIENT FROM THE STRONG HIGH PRESSURE SYSTEM...AND STRONG COLD AIR ADVECTION...WILL PROVIDE TURBULENT AIR MIXING...ALLOWING SOME STRONG WIND GUSTS TO REACH THE SURFACE...ESPECIALLY OVER THE OUTER WATERS. THEREFORE...SMALL CRAFT ADVISORY CONDITIONS WILL OVERTAKE THE COASTAL WATERS TONIGHT...WITH A GALE WARNING FOR FREQUENT WIND GUSTS OVER 40 KNOTS...BEYOND 20 NM. THE NORTH WIND WILL ALSO PUSH WATER OUT OF THE CHANNELS AND BAYS AND AWAY FROM THE COAST. THEREFORE...A LOW WATER ADVISORY WILL ALSO BE IN EFFECT FOR THE COASTAL LAKES AND BAYS FROM ROUGHLY MIDNIGHT TONIGHT THROUGH NOON MONDAY. THE STRONG NORTHERLY WINDS WILL BEGIN TO DECREASE BY TUESDAY AS THE COLD AIR ADVECTION BEGINS TO WANE AND THE HIGH PRESSURE SYSTEM SETTLES OVER THE REGION. RUA && .PRELIMINARY POINT TEMPS/POPS... KLCH 44 50 27 49 32 / 80 10 0 0 0 KBPT 41 51 29 50 37 / 70 10 0 0 0 KAEX 38 47 24 46 29 / 80 10 0 0 0 KLFT 48 49 27 47 31 / 90 10 0 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...WIND ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING ZONES: ACADIA...ALLEN...BEAUREGARD...CALCASIEU...EAST CAMERON... IBERIA...JEFFERSON DAVIS...LAFAYETTE...ST. MARY... VERMILION...WEST CAMERON. TX...WIND ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING ZONES: JEFFERSON...ORANGE. GM...SMALL CRAFT ADVISORY FROM NOON MONDAY TO NOON CST TUESDAY FOR THE FOLLOWING ZONES: WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. GALE WARNING UNTIL NOON CST MONDAY FOR THE FOLLOWING ZONES: WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. GALE WARNING UNTIL NOON CST MONDAY FOR THE FOLLOWING ZONES: WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM. LOW WATER ADVISORY UNTIL NOON CST MONDAY FOR THE FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE...VERMILION BAY. SMALL CRAFT ADVISORY UNTIL NOON CST MONDAY FOR THE FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE...VERMILION BAY. SMALL CRAFT ADVISORY UNTIL NOON CST TUESDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM. SMALL CRAFT ADVISORY UNTIL NOON CST TUESDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSLAKECHARLES WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1021 PM CST SUN NOV 16 2014 .UPDATE...ZONES AND GRIDS UPDATED TO REFLECT WIND ADVISORY. BEAUMONT IS JUST NOW APPROACHING WIND ADVISORY CRITERIA. THE SECONDARY FRONTAL BAND EXTENDS FROM BEAUMONT TO DERIDDER AND ALEXANDRIA. THIS BAND IS MOVING SOUTHEAST AT AROUND 25 MPH. GUSTS TO 35 MPH APPEAR POSSIBLE. SWEENEY && .PREV DISCUSSION... /ISSUED 937 PM CST SUN NOV 16 2014/ UPDATE...MADE MINOR ADJUSTMENT TO THE SURFACE WINDS WITH SLIGHTLY STRONGER WINDS OVERNIGHT WITH THE REINFORCING COLD FRONT CURRENTLY MOVING THROUGH SOUTHEAST TEXAS AND CENTRAL LOUISIANA. BLENDED IN LATEST RUC TEMP DATA AND DEW POINT TRENDS AS WELL AS ACCOUNTING FOR A SLOWER MOVEMENT OF THE COLD FRONT THROUGH ACADIANA TO ADJUST OVERNIGHT TEMPERATURES. STILL QUITE A DROP EXPECTED BUT NOW EXPECTING MID 40S FOR SW LA AND UPPER 40S FOR S CEN LA BY SUNRISE DUE LARGELY TO THE INCREASING WINDS. THESE CHANGES WILL BE REFLECTED IN ANOTHER ZONE UPDATE OUT SHORLTY. SWEENEY PREV DISCUSSION... /ISSUED 832 PM CST SUN NOV 16 2014/ UPDATE...WENT AHEAD AND CANCELLED THE TOR WATCH A COUPLE OF HOURS EARLY. WAS IN THE PROCESS OF TRIMMING BACK HOWEVER THE WINDS AND LIFT BOTH APPEAR TO HAVE WEAKEND AROUND THE FRONTAL BAND. ZONE UPDATE TO FOLLOW. SWEENEY PREV DISCUSSION... /ISSUED 553 PM CST SUN NOV 16 2014/ AVIATION... STRONG THUNDERSTORMS ARE RUMBLING THRU SOUTH CENTRAL LA AND WILL BE AN OPERATIONAL ISSUE FOR ARA AND LFT OVER THE NEXT HOUR OR SO. OTHERWISE LOW CEILINGS WITH PERIODS OF RAINS AND FOG WILL KEEP VSBY DOWN AT TIMES. CONDITIONS WILL IMPROVE AS A SECOND FRONT MOVES THROUGH LATE TONIGHT WITH WINDS PICKING UP. PREV DISCUSSION... /ISSUED 344 PM CST SUN NOV 16 2014/ DISCUSSION... BUSY WEATHER SITUATION ACROSS THE FORECAST AREA...WITH CONDITIONS VARYING FROM SPRING TO WINTER WITH SOME 25F DEGREE AIR TEMPERATURE BETWEEN THE NORTHWEST PORTION OF THE FORECAST AREA WITH THE SOUTHEAST. OLD FRONTAL BOUNDARY IS BISECTING THE FORECAST AREA WITH A SURFACE LOW/FRONTAL WAVE LOCATED AS OF 16/21Z BETWEEN JENNINGS AND LAFAYETTE. WARM SECTOR ON THE EAST SIDE OF THE LOW EXTENDS FROM EASTERN ST. LANDRY PARISH NEAR THE ATCHAFALAYA BASIN TO INTO THE GULF WATERS AROUND THE CAMERON/VERMILION PARISH BORDER. SOME STRONG LOW LEVEL INFLOW WITH A VERY WARM AND MOIST ENVIRONMENT IS LEADING TO THE DEVELOPMENT OF SHOWERS WITH SOME EMBEDDED STRONG THUNDERSTORMS IN THE WARM SECTOR. THERE IS A CHANCE OF SOME ROTATING CELLS BECOMING SURFACE BASED IN THE WARM SECTOR...AND THEREFORE...SPC HAS ISSUED A TORNADO WATCH FOR SOUTH CENTRAL LOUISIANA THROUGH 10 PM...ALTHOUGH THE THREAT SHOULD DIMINISH FOR PORTIONS OF THE AREA BEFORE THEN...AS THE LOW CONTINUES TO MOVE TO THE NORTHEAST AND LOSS OF DAYTIME HEATING DECREASES THE LOW LEVEL INSTABILITY. ANOTHER STRONG COLD FRONT WITH ARCTIC ORIGINS IS CURRENTLY MOVING SOUTHEAST ACROSS NORTHEAST TEXAS AND NORTHWEST LOUISIANA. THIS SYSTEM WILL MOVE INTO THE FORECAST AREA THIS EVENING AND INTO THE COASTAL WATERS DURING THE OVERNIGHT. SHOWERS WILL DECREASE BEHIND THIS FRONT AS MUCH DRIER AIR BEGINS TO MOVE IN...ALONG WITH BLUSTERY CONDITIONS. COLD AIR ADVECTION WILL CONTINUE ON MONDAY...AS THE STRONG HIGH PRESSURE SYSTEM BUILDS DOWN FROM THE NORTH. CLEAR SKIES ARE EXPECTED ON MONDAY NIGHT INTO TUESDAY MORNING...WITH A DECREASE IN WINDS EXPECTED. THEREFORE...A VERY COLD NIGHT IS EXPECTED WITH A FREEZE FOR A MAJORITY OF THE FORECAST AREA...AND HARD FREEZE CONDITIONS GETTING DOWN CLOSE TO I-10. CONDITIONS WILL BEGIN TO MODERATE BY MID-WEEK AS THE HIGH MOVES OFF TO THE EAST...AND RETURN FLOW OFF THE GULF COMMENCES. ENOUGH MOISTURE BUILD-UP BY THURSDAY INTO THE WEEKEND...TO INCLUDE A CHANCE FOR SHOWERS AND STORMS AS A SERIES OF UPPER LEVEL DISTURBANCES MOVE ACROSS. RUA MARINE... A SURFACE LOW/FRONTAL WAVE WILL MOVE ACROSS SOUTH CENTRAL LOUISIANA THIS EVENING...THEN SOUTHEAST LOUISIANA TONIGHT. MODERATE SOUTHERLY WINDS AND INSTABILITY WILL BRING ABOUT SHOWERS AND STORMS...ESPECIALLY EAST OF CAMERON DURING THE EVENING HOURS. SOME OF THESE STORMS WILL PRODUCE FREQUENT LIGHTNING...STRONG WINDS...AND EVEN AN ISOLATED WATER SPOUT CAN NOT BE RULED OUT. A STRONG COLD FRONT...WILL THEN MOVE ACROSS THE COASTAL WATERS LATER TONIGHT...REACHING THE WESTERN PORTIONS OF THE COASTAL WATERS DURING THE LATE EVENING HOURS...AND THEN ACROSS THE REMAINDER OF THE COASTAL WATERS AFTER MIDNIGHT. AIR FROM THE POLAR REGION WILL BE BEHIND THIS FRONT. THE DEVELOPING PRESSURE GRADIENT FROM THE STRONG HIGH PRESSURE SYSTEM...AND STRONG COLD AIR ADVECTION...WILL PROVIDE TURBULENT AIR MIXING...ALLOWING SOME STRONG WIND GUSTS TO REACH THE SURFACE...ESPECIALLY OVER THE OUTER WATERS. THEREFORE...SMALL CRAFT ADVISORY CONDITIONS WILL OVERTAKE THE COASTAL WATERS TONIGHT...WITH A GALE WARNING FOR FREQUENT WIND GUSTS OVER 40 KNOTS...BEYOND 20 NM. THE NORTH WIND WILL ALSO PUSH WATER OUT OF THE CHANNELS AND BAYS AND AWAY FROM THE COAST. THEREFORE...A LOW WATER ADVISORY WILL ALSO BE IN EFFECT FOR THE COASTAL LAKES AND BAYS FROM ROUGHLY MIDNIGHT TONIGHT THROUGH NOON MONDAY. THE STRONG NORTHERLY WINDS WILL BEGIN TO DECREASE BY TUESDAY AS THE COLD AIR ADVECTION BEGINS TO WANE AND THE HIGH PRESSURE SYSTEM SETTLES OVER THE REGION. RUA && .PRELIMINARY POINT TEMPS/POPS... KLCH 44 50 27 49 32 / 80 10 0 0 0 KBPT 41 51 29 50 37 / 70 10 0 0 0 KAEX 38 47 24 46 29 / 80 10 0 0 0 KLFT 48 49 27 47 31 / 90 10 0 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...WIND ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING ZONES: ACADIA...ALLEN...BEAUREGARD...CALCASIEU...EAST CAMERON... IBERIA...JEFFERSON DAVIS...LAFAYETTE...ST. MARY... VERMILION...WEST CAMERON. TX...WIND ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING ZONES: JEFFERSON...ORANGE. GM...SMALL CRAFT ADVISORY FROM NOON MONDAY TO NOON CST TUESDAY FOR THE FOLLOWING ZONES: WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. GALE WARNING UNTIL NOON CST MONDAY FOR THE FOLLOWING ZONES: WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. GALE WARNING UNTIL NOON CST MONDAY FOR THE FOLLOWING ZONES: WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM. LOW WATER ADVISORY UNTIL NOON CST MONDAY FOR THE FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE...VERMILION BAY. SMALL CRAFT ADVISORY UNTIL NOON CST MONDAY FOR THE FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE...VERMILION BAY. SMALL CRAFT ADVISORY UNTIL NOON CST TUESDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM. SMALL CRAFT ADVISORY UNTIL NOON CST TUESDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSLAKECHARLES WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
640 PM EST TUE NOV 18 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 421 PM EST TUE NOV 18 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A HIGHLY AMPLIFIED PATTERN OVER NAMERICA...FEATURING A STRONG RIDGE OVER THE WRN PART OF THE CONTINENT AND A DEEP TROF EXTENDING S DOWN THE MISSISSIPPI RIVER VALLEY. WITH THE TROF SLOWLY SHIFTING E...SFC WINDS ARE IN THE PROCESS OF BACKING...AND THUS LES IS SHIFTING AS WELL. LES IS NOW CONFINED TO AREAS FROM THE PORCUPINE MTNS NORTHWARD AND ROUGHLY EAST OF A MUNISING-GERMFASK LINE. UPSTREAM 12Z SOUNDINGS AT KINL/CWPL STILL SHOWED MOISTURE EXTENDING UP TO AROUND 800MB...SO LES INTENSITY REMAINS MDT/HVY IN THE MAIN BANDS...ESPECIALLY WITH SHORT TERM MODEL GUIDANCE STILL SHOWING A NICE INTERSECTION OF BEST UPWARD MOTION CENTERED IN THE DGZ. SHORT TERM FCST CONTINUES TO RESEMBLE CONDITIONS IN THE HEART OF WINTER. WITH ONE LAKE EFFECT EVENT CURRENTLY WINDING DOWN...NEXT SYSTEM THAT WILL BRING ANOTHER ROUND OF MDT TO HVY LES WILL BE MOVING INTO THE UPPER GREAT LAKES ALREADY ON WED. TONIGHT...PAIR OF SHORTWAVES WILL BE DROPPING SSE THRU SASKATCHEWAN/MANITOBA (SECOND STRONGER THAN THE LEAD). AS A RESULT...WINDS WILL CONTINUE TO BACK TONIGHT...REACHING SW BY 12Z WED. SO...EXPECT LAKE SUPERIOR LES TO SHIFT COMPLETELY OFFSHORE OF UPPER MI DURING THE OVERNIGHT. AT LEAST THRU 12Z...WINDS WON`T HAVE ENOUGH SOUTHERLY COMPONENT TO BRING ANY LES CONCERNS OFF LAKE MICHIGAN INTO SCHOOLCRAFT/LUCE COUNTIES. THERE WILL BE SOME ENHANCED CONVERGENCE ON THE BACK EDGE OF THE LINGERING LES WHERE BACKING WINDS INTERSECT WITH WINDS THAT STAY MORE VEERED LONGER OVER THE RELATIVELY WARM WATERS OF THE LAKE. AS A RESULT...THE LAST SNOW BAND LIFTING N ACROSS WRN UPPER MI TONIGHT AND THE LAST SHIFTING E ACROSS THE ERN FCST AREA THIS EVENING WILL BE FAIRLY HVY. OVER THE W...THIS BAND MIGHT PROVIDE A QUICK INCH OR TWO OF SNOW...ESPECIALLY ACROSS THE KEWEENAW AS FETCH ACROSS THE WATER INCREASES AS THE ORIENTATION OF THE BAND BECOMES W-E THEN WSW-ENE UNDER BACKING WINDS. AN INCH OR TWO OF SNOW IS ALSO LIKELY OVER THE NE FCST AREA BEFORE LES SHIFTS OFFSHORE. AS LAKE EFFECT CLOUDS SHIFT N...THERE SHOULD BE A PERIOD OF PARTIAL CLEARING BEFORE CLOUDS BEGIN TO OVERSPREAD THE AREA AHEAD OF THE INCOMING SHORTWAVES. HOWEVER...THAT`S NOT CERTAIN GIVEN THE LARGE MASS OF STRATOCU TO THE W. WITH MUCH OF THOSE CLOUDS PRESENT BEFORE SUNRISE TODAY...NOT ALL OF THOSE CLOUDS WERE DIURNALLY DRIVEN...SO THEY MAY BE SLOWER TO DISSIPATE TONIGHT. FOR NOW... DIDN`T GO TOO LOW WITH MINS. TRADITIONAL COLD SPOTS MAY SLIP JUST BELOW 0F. ALTHOUGH DEEP LAYER FORCING SPREADS INTO WRN UPPER MI LATE TONIGHT IN ASSOCIATION WITH APPROACHING SHORTWAVES...LOW-LEVELS ARE SLOW TO MOISTEN. WILL CONTINUE TO CARRY JUST SCHC POPS ALONG THE WI BORDER AND LOW CHC POPS OVER THE W TOWARD KIWD LATE TONIGHT. ON WED....MAIN SHORTWAVE WILL BE DIVING INTO THE UPPER GREAT LAKES. AT THE SFC...ASSOCIATED LOW PRES TROF WILL ALSO SWING INTO THE UPPER GREAT LAKES AND THEN BEGIN TO DEEPEN OVER THE WARMER WATERS. AHEAD OF THE DEEPENING SFC TROF...LOW-LEVEL WINDS WILL CONTINUE TO BACK... BRINGING CONCERNS FOR LAKE ENHANCED SNOW SPREADING N AND W OFF LAKE MICHIGAN INTO SCHOOLCRAFT/LUCE COUNTIES. OF THE HIGH RES MODELS... THE NAM/GEM ARE A LITTLE SLOWER AND ALLOW WINDS TO BACK ENOUGH TO BRING HEAVIER SNOW INTO THE FAR ERN FCST AREA IN THE MID TO LATE AFTN. THE NCEP ARW AND NMM ARE FASTER AND NEVER REALLY QUITE BACK THE WINDS SUFFICIENTLY TO BRING SNOW FAR ENOUGH W. OPTED TO LEAN TOWARD THE NAM/GEM WITH THE IDEA OF FALLING PRES ALONG TROF HELPING TO BACK WINDS/SLOW TROF DOWN...ESPECIALLY WITH THE MAGNITUDE OF THE COLD AIR ALREADY OVER THE AREA THAT WILL ENHANCE LATENT/SENSIBLE HEATING OVER THE LAKES. FOR NOW...PAINTED AS MUCH AS 2-4 INCHES OF SNOW IN FAR SE SCHOOLCRAFT COUNTY AND SE LUCE COUNTY BY 00Z THU. COULD BE QUITE A BIT MORE IF WINDS BACK ENOUGH AND THEN DON`T SHIFT FOR SEVERAL HRS. TO THE W...EXPECT HVY LAKE ENHANCED SNOW TO DEVELOP ALONG SFC TROF AXIS AS IT SWINGS ACROSS WRN LAKE SUPERIOR. THAT HVY SNOW WILL PUSH ONSHORE IN THE AFTN...PROVIDING 2 TO 4 INCHES OF ACCUMULATION. ELSEWHERE...EXPECT SOME -SN IN ASSOCIATION WITH SHORTWAVE. ACCUMULATIONS SHOULD GENERALLY BE AROUND 1 INCH. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 441 PM EST TUE NOV 18 2014 NEW LAKE EFFECT SNOW ADVISORIES WILL NEED TO BE HOISTED ONCE AGAIN IN THE NW WIND SNOW BELTS FOR WEDNESDAY LATE AFTERNOON/EARLY EVENING THROUGH MUCH OF THURSDAY. MAY GET CLOSE TO THE 24 HOUR /12IN OR MORE/ WARNING CRITERIA IF BANDED PRECIP STAYS OVER E ALGER AND N PORTIONS OF LUCE COUNTY. WILL NOT HOIST ANY NEW HEADLINES AT THIS TIME...TO LIMIT CONFUSION WITH THE ONGOING ADVISORIES OVER THE E HALF OF UPPER MI. PERSISTENT NW FLOW FROM 00Z THURSDAY THROUGH 00Z FRIDAY WILL KEEP MODERATE TO AT TIMES HEAVY LES GOING...AS NOTED ABOVE...BEHIND THE EXITING SFC LOW OVER N AND E LAKE SUPERIOR AT 00Z THURSDAY. THE LOW WILL DEEPEN ACROSS THE S ONTARIO/QUEBEC BORDER AT 12Z THURSDAY...WITH THE SFC TROUGH LINGERING ACROSS THE AREA. THE LARGE AREA OF HIGH PRESSURE EXTENDING FROM THE N PLAINS THROUGH THE GULF COAST THURSDAY AFTERNOON WILL PUSH A RIDGE ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT THROUGH FRIDAY...BEFORE THE PARENT HIGH EXITS TO THE MID ATLANTIC. THIS WILL PUSH THE RIDGE OVER THE LOWER GREAT LAKES. AT THAT POINT WE WILL BRIEFLY SAY GOODBYE TO OUR COLD WINTER WEATHER. STRONG WAA WILL BE THE RULE FRIDAY NIGHT IN ADVANCE OF LOW PRESSURE TO THE W /FROM A SFC LOW OVER MANITOBA...AND ANOTHER ONE ORGANIZING ACROSS THE S PLAINS/. LOOK FOR SFC TEMPS TO RISE INTO THE 30S SATURDAY...SUNDAY...AND MONDAY. THE INITIAL LOW OVER MANITOBA WILL SKIRT ACROSS ONTARIO INTO S HUDSON BAY SATURDAY...WITH THE SFC RIDGE ERODING ACROSS UPPER MI. FCST SOUNDINGS INDICATE THE POTENTIAL FOR FREEZING DRIZZLE /OR MORE LIKELY FREEZING RAIN IF THE HIGHER QPF LIKE THAT FROM THE 18/12Z ECMWF PAN OUT. THE GFS IS LESS ROBUST...SO WILL ONLY ADD THE MENTION FOR NOW AND WAIT UNTIL FCST SOLUTIONS COME TO A BETTER CONSENSUS BEFORE HIGHLIGHTING MORE THAN JUST LIGHT PRECIP /FREEZING DRIZZLE/. THE NEXT CONCERN FOR THE PERIOD WILL BE THE INTERACTION/PHASING OF THE S STREAM LOW EJECTING OUT OF THE S PLAINS SUNDAY...AND AN ADDITIONAL LOW PUSHING ACROSS THE ND/CANADA BORDER SUNDAY MORNING. LOOK FOR THE S LOW TO PUSH ACROSS LAKE MI/ILLINOIS BY 00Z MONDAY...AND CONTINUE TO DEEPEN ACROSS E UPPER MI/W LAKE HURON BY DAYBREAK MONDAY. GIVEN WHERE THIS SYSTEM IS COMING FROM...RAIN WILL BE POSSIBLE INITIALLY. HOW MUCH OF THAT FALLS AS FREEZING RAIN/OVER OUR SNOW PACK IS IN QUESTION. PRECIP WILL TRANSITION BACK TO ALL SNOW SUNDAY NIGHT-MONDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 639 PM EST TUE NOV 18 2014 LAKE EFFECT SNOWBANDS CONTINUE TO MOVE NORTH AS WINDS SHIFT TO THE SOUTHWEST. LES TO END AT KCMX WITH THIS WIND SHIFT AS WEAK BAND MOVES OFF THE KEWEENAW PENINSULA. LATEST SATELLITE IMAGERY AND SFC OBSERVATIONS SHOW AREAS OF MVFR CIGS CONTINUING TO MOVE TOWARD THE AREA. WHILE KSAW HAS TEMPORARILY BROKEN OUT IN TO VFR CONDITIONS... CLOUD COVER WILL MOVE BACK IN BY MIDNIGHT THERE. KIWD WILL ALSO SEE A FEW PERIODS OF VFR...BUT CIGS WILL MAINLY BE MVFR THROUGH THE NIGHT THERE. SNOW RETURNS TO THE REGION WITH THE APPROACH OF THE NEXT SYSTEM WITH VSBYS FALLING LATE IN THE FORECAST AS LES DEVELOPS WITH WINDS SHIFTING WEST. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 PM EST TUE NOV 18 2014 THE BRIEF RIDGE ACROSS LAKE SUPERIOR THIS EVENING WILL BE REPLACED BY TROUGH WEDNESDAY MORNING...THAT WILL DEEPEN WEDNESDAY EVENING ACROSS N AND E LAKE SUPERIOR. OUR INITIAL GUSTS NEARING 20-30KTS WILL BE ON THE INCREASE AGAIN WEDNESDAY NIGHT THROUGH EARLY THURSDAY AFTERNOON...WITH W-NW GALE FORCE GUSTS NEARING 35KTS. A GALE WATCH HAS BEEN ISSUED FOR THIS PERIOD ACROSS PORTIONS OF CENTRAL AND E LAKE SUPERIOR. EXPECT THE LOW TO EXIT ACROSS S QUEBEC ON THURSDAY. LOOK FOR A RIDGE ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT THROUGH FRIDAY...BEFORE SHIFTING TO THE LOWER GREAT LAKES LATE FRIDAY AFTERNOON THROUGH FRIDAY EVENING. LOW PRESSURE ACROSS MANITOBA FRIDAY NIGHT WILL SWING ACROSS ONTARIO AND SOUTHERN HUDSON BAY SATURDAY...WITH THE RIDGE ACROSS LAKE SUPERIOR WEAKENING SLIGHTLY. EXPECT A VERY DEEP LOW ACROSS THE MID MS VALLEY SUNDAY MORNING TO PUSH OVER THE UPPER GREAT LAKES SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ006- 007-085. LAKE SUPERIOR... GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING FOR LSZ266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING FOR LSZ264. GALE WATCH FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY NIGHT FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...RJT MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
501 PM EST MON NOV 17 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 500 PM EST MON NOV 17 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGHLY AMPLIFIED PATTERN OVER NAMERICA...FEATURING A STRONG RIDGE OVER THE WRN PART OF THE CONTINENT AND A SHARP...DEEPENING DOWNSTREAM TROF OVER THE CNTRL PART. WITH THE RIDGE...THE 500MB HEIGHT ANOMALY PEAKS AT 2.5 STANDARD DEVIATIONS ABOVE AVG FOR THIS TIME OF YEAR OVER FAR NW CANADA WHILE THE DOWNSTREAM TROF IS DEEPENING TOWARD 3.5 STANDARD DEVIATIONS BELOW AVG OVER THE UPPER MISSISSIPPI VALLEY BY EVENING. AT THE SFC...LOW PRES WAS LOCATED OVER FAR NE LAKE SUPERIOR WITH SFC TROF EXTENDING SW INTO WRN UPPER MI. UPSTREAM 12Z SOUNDINGS AT KINL/CWPL SHOWED DEEP MOISTURE EXTENDING UP PAST 500MB WITH 850MB TEMPS OF -19/-20C RESPECTIVELY...OBVIOUSLY A FAVORABLE SETUP FOR HVY SNOW OFF LAKE SUPERIOR. THE SHORT TERM FCST WILL BE DOMINATED BY LES TRENDS/SNOW AMOUNTS AND HEADLINES. MDT/HVY SNOW HAS CONTINUED TO EXPAND OVER WRN UPPER MI THIS AFTN AND THAT WILL CONTINUE THIS EVENING AS WEAK DEEP LAYER FORCING/DEEP MOISTURE AND ESSENTIALLY AN ABSENT INVERSION ALLOW FOR DEEP LAKE EFFECT CONVECTION. ALTHOUGH DGZ IS ONLY AROUND 2KFT THICK...FCST SOUNDINGS SHOW IT IDEALLY PLACED WITHIN MAX UPWARD MOTION. HIGHER RES MODEL GUIDANCE CONTINUES TO SHOW BEST LOW-LEVEL CONVERGENCE TONIGHT IN AN AREA FROM KIWD INTO CNTRL/SRN HOUGHTON COUNTY AND ALSO DEVELOPING THIS EVENING IN ALGER/NRN SCHOOLCRAFT COUNTIES. THUS... EXPECT HEAVIEST SNOWFALL IN THESE AREAS. WHILE THE W GETS A BETTER BOOST FROM TERRAIN ENHANCEMENT...A NICE LAKE NIPIGON CONNECTION AND LAND BREEZE CONVERGENCE OFF MARQUETTE COUNTY WILL BOOST SNOWFALL INTO ALGER/NRN SCHOOLCRAFT. ISOLATED LOCATIONS IN BOTH AREAS MAY SEE TOTAL SNOW ACCUMULATIONS AROUND 20 INCHES BY THE TIME THE SNOW DIMINISHES/ENDS. OTHERWISE...12-18 INCHES OF SNOW WILL GENERALLY BE THE RULE. A LITTLE CONCERNED ABOUT HOW FAR THE HEAVIER SNOW MAY EXTEND INTO SRN SCHOOLCRAFT TONIGHT. IF DOMINANT BAND SETS UP AND DOESN`T MOVE MUCH FOR SEVERAL HRS...AMOUNTS MAY SNEAK INTO WARNING CRITERIA THERE. OVER NRN HOUGHTON/KEWEENAW COUNTIES...MANY LOCATIONS WILL PROBABLY END UP WITH SUB WARNING AMOUNTS GIVEN LACK OF ENHANCING FACTORS THAT ARE PRESENT IN THE OTHER AFORMENTIONED AREAS. BEST POTENTIAL OF EXCEEDING A FOOT WILL BE SOUTH OF PAINESDALE AND PERHAPS NRN KEWEENAW COUNTY AS LAKE NIPIGON CONNECTION MAY IMPACT THAT AREA FOR A TIME THIS EVENING. BLSN WILL BE MORE SIGNIFICANT ACROSS THE KEWEENAW...SO THAT WILL BE A FACTOR SUPPORTING MAINTAINING WARNING HEADLINES FOR NOW. CONSIDERED DROPPING ADVY FOR MARQUETTE COUNTY AS WINDS HAVE A BIT TOO MUCH OF A WESTERLY COMPONENT TO BRING MUCH OF THE HEAVIER SNOW INTO THE COUNTY. HAVE LOWERED SNOW ACCUMULATIONS...BUT SOME HIGH RES GUIDANCE CONTINUES TO SHOW HEAVIER SNOW BANDS BRUSHING THE SHORELINE AREAS. IN PARTICULAR...THE AREA TOWARD SHOT POINT MAY BE AFFECTED BY HVY SNOW AT TIMES. WRN PART OF THE COUNTY MAY SEE FAIRLY PERSISTENT SNOW FOR THE NEXT SEVERAL HRS AS WELL BEFORE WINDS VEER A LITTLE MORE NW. FOR NOW...MAINTAINED MARQUETTE COUNTY ADVY...BUT EVENING SHIFT MAY BE ABLE TO DROP ADVY IF IT DOES APPEAR HEAVIER SNOW WILL REMAIN E. ON TUE...DEEP MOISTURE SLOWLY SHIFTS E...LARGER SCALE LOW-LEVEL FLOW TRENDS ANTICYCLONIC AND OVERALL LOW-LEVEL CONVERGENCE WEAKENS. THIS WILL SPELL DIMINISHING LES FROM W TO E DURING THE DAY. BACKING WINDS WILL PUSH LINGERING -SHSN N OF KIWD DURING THE AFTN AND SHIFT THE BACK EDGE OF LES EASTWARD WITH TIME IN CNTRL UPPER MI. THOSE BACKING WINDS WILL ALSO LEAD TO A NARROW ENHANCED CONVERGENCE ZONE SHIFTING N OVER FAR WRN UPPER MI LATER IN THE AFTN...RESULTING IN A NARROW BAND OF HEAVIER SNOW SHIFTING N TOWARD HOUGHTON IN THE EVENING. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 444 PM EST MON NOV 17 2014 BY 00Z WEDNESDAY THE 500MB LOW WILL HAVE SHIFTED FROM FAR E ONTARIO TO E QUEBEC...WITH RIDGING AT THE SFC AND ALOFT. THIS WILL ALLOW THE NEAR SFC WINDS TO SHIFT A BIT MORE OUT OF THE W AND SW OVERNIGHT...ALLOWING LES TO PUSH OFFSHORE AND INTO LAKE SUPERIOR. THIS DRY WX WILL BE TEMPORARILY...AS THE NEXT SFC TROUGH AND 500MB SHORTWAVE LOOK TO BE SET UP ACROSS MN ALREADY AT 06Z WEDNESDAY. THERE ISN/T A LOT OF MOISTURE TO WORK WITH INITIALLY. HOWEVER...THE SFC THROUGH WILL SLIDE ACROSS W AND CENTRAL UPPER MI BY 18Z WEDNESDAY...WITH STRONGER DYNAMICS MOVING IN LATER WEDNESDAY AFTERNOON. NW WINDS BEHIND THIS TROUGH DOES NOT LOOK TOO STRONG WEDNESDAY NIGHT INTO THURSDAY /AT LEAST COMPARED TO THE NEARLY 40KTS OF THIS CURRENT SYSTEM/. WINDS ARE MORE ON THE ORDER OF 30KTS ABOVE 900MB. A 500MB LOW ROTATING IN WEDNESDAY NIGHT WILL USHER IN MUCH COOLER AIR...WITH 850MB TEMPS FALLING FROM AN AVERAGE -14C WEDNESDAY AFTERNOON TO AROUND -19C BY THURSDAY AFTERNOON. THE GFS IS A COUPLE DEGREES WARMER ALOFT THAN THE ECMWF VALUES LISTED ABOVE. THIS SHOULD HAVE LITTLE IMPACT ON THE OVERALL TRENDS. CONTINUE TO HIGHLIGHT THE POTENTIAL FOR MODERATE TO HEAVY LAKE EFFECT SNOW SHOWERS LATE WEDNESDAY AFTERNOON/WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. LOOK FOR A CHANGE IN THE PERSISTENT COOL NW FLOW THURSDAY NIGHT...WITH CLEARING CONDITIONS OVER THE INTERIOR W HALF. THIS SHOULD ALLOW SFC TEMPS TO FALL TO AROUND 0F. THE DEEPENING/EXITING SFC LOW OVER S QUEBEC THURSDAY WILL KEEP A TROUGH ACROSS THE UPPER GREAT LAKES INTO THURSDAY EVENING...AS LARGE 500MB TROUGH FINALLY EXITS INTO E CANADA. LOOK FOR LES TO SLOWLY END ONCE AGAIN AS WINDS BECOME A BIT MORE VARIANT...SHIFTING OUT OF THE W. HIGH PRESSURE WILL THEN RETURN TO THE AREA...WITH DRY WEATHER FOR MUCH OF FRIDAY INTO SATURDAY. FRIDAY NIGHT INTO SATURDAY IS A BIT OF A CONUNDRUM...WITH STRONG WAA ON 850MB WINDS OF 40-50KTS FCST OFF BOTH THE 12Z GFS AND ECMWF. WHILE WINTER IS FAR FROM OVER...WE MAY GET A BIT OF A BREAK FROM THE WHITE STUFF. MAY HAVE WAA SHOWERS SATURDAY AFTERNOON IN ADVANCE OF THE SFC TROUGH AND ASSOCIATED SHORTWAVE ACROSS NW MN. AT THIS POINT THE BEST CHANCE FOR A MIX OF RAIN AND SNOW WILL BE ACROSS LAKE MI. WILL NOT GET TOO INTO THE DETAILS FOR SUNDAY AND MONDAY...OTHER THAN TO NOTE THAT MUCH WARMER AIR LOOKS TO PUSH IN FOR SUNDAY. HIGHS COULD TOP OUT IN THE MID TO UPPER 30S...AS S-SSE WINDS CONTINUE IN ADVANCE OF LOW PRESSURE EJECTING OUT OF THE S PLAINS. THE 12Z ECMWF TRACKS A VERY STRONG/WRAPPED UP 927MB SFC LOW ACROSS WI AND UPPER MI SUNDAY NIGHT INTO MONDAY. WHILE THE GFS IS SHOWING A SIMILAR FEATURE...ITS/S TRACK IS ACROSS LOWER MI STARTING OFF AT 989MB AND WEAKENING OVER THIS TIME PERIOD. WILL KEEP A GENERAL BLEND GOING FOR FRIDAY NIGHT AND BEYOND. WOULD NOT BE SURPRISED IF WE NEED TO INCREASE OUR CURRENT WIND FCST FOR THIS PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1216 PM EST MON NOV 17 2014 DEEP MID/UPPER LEVEL TROF AND ASSOCIATED DEEP MOISTURE PUSHING ACROSS THE AREA WILL LEAD TO HEAVIER LAKE EFFECT SNOW SHOWERS AFFECTING KIWD/KCMX UNDER NW FLOW. COMBINATION OF SNOW AND GUSTY NW WINDS CREATING BLSN WILL LIKELY RESULT IN LIFR CONDITIONS PREVAILING AT BOTH TERMINALS. AS DEEPER MOISTURE BEGINS TO EXIT...EXPECT IMPROVEMENT TO IFR LATE TONIGHT/EARLY TUE MORNING AND THEN TO MVFR BY TUE AFTN. AT KSAW...NW WIND DIRECTION WILL NOT BE FAVORABLE FOR ANYTHING MORE THAN -SHSN AT TIMES. MVFR CIGS WILL DEVELOP THIS AFTN AND CONTINUE THRU THE REMAINDER OF THE FCST PERIOD. THERE MAY BE A FEW PERIODS OF MVFR VIS IN -SHSN LATER THIS AFTN. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 500 PM EST MON NOV 17 2014 LOW PRESSURE OVER FAR NE LAKE SUPERIOR WILL SHIFT EAST THIS EVENING WITH TRAILING SFC TROF SWEEPING SE. BEHIND THE TROF...EXPECT NW GALES OF 35-40KT TO SRPEAD FROM WRN LAKE SUPERIOR TO ERN LAKE SUPERIOR. COULD BE SOME GUSTS TO NEAR 45KT OVER SCNTRL LAKE SUPERIOR FOR A TIME TONIGHT. GALES WILL END OVER THE W OVERNIGHT AND OVER THE E LATE TUE MORNING/EARLY AFTN. COLD AIR/STRONG WINDS/HIGH WAVES WILL ALSO LEAD TO SOME FREEZING SPRAY. WINDS SHOULD GENERALLY BE IN THE 15-25KT RANGE TUE NIGHT AS WINDS BACK SW AHEAD OF THE NEXT TROF. THAT TROF WILL SWEEP ACROSS THE LAKE WED AFTN/EVENING...FOLLOWED BY ANOTHER ROUND OF NW WINDS TO AT LEAST 30KT. GALES MAY OCCUR OVER THE E HALF OF THE LAKE WED NIGHT/THU MORNING. NO ADDITIONAL GALES ARE EXPECTED THRU SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ TUESDAY FOR MIZ001>003-009-084. LAKE EFFECT SNOW WARNING UNTIL 7 PM EST TUESDAY FOR MIZ006-085. LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ007. LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ004-005. LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ014. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 1 PM EST TUESDAY FOR LSZ251-267. GALE WARNING UNTIL 1 PM EST TUESDAY FOR LSZ248>250-265-266. GALE WARNING UNTIL 9 AM EST TUESDAY FOR LSZ264. GALE WARNING UNTIL 4 AM EST /3 AM CST/ TUESDAY FOR LSZ240>242- 263. GALE WARNING UNTIL 7 AM EST TUESDAY FOR LSZ243>245. GALE WARNING UNTIL 1 AM EST /MIDNIGHT CST/ TUESDAY FOR LSZ162. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
452 PM EST MON NOV 17 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EST MON NOV 17 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS INDICATE A DEEPENING UPR TROF OVER CENTRAL NAMERICA WITH CLOSED H5 LO OVER ONTARIO JUST NW OF LK SUP CAUSING 12HR H5 HGT FALLS UP TO 130M BTWN 16/12Z AND 17/00Z AT INL AND DRAWING H5 TEMPS CLOSE TO -40C S UNDER THE AXIS OF LOWEST HGTS. BAND OF DPVA/DEEP LYR QVECTOR CNVGC/AXIS OF MID LVL MSTR IN ADVANCE OF SHRTWV ROTATING ARND THE CLOSED LO IS CROSSING UPR MI EARLY THIS MRNG...BUT DRYNESS OF AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.16 INCH IS 45 PCT OF NORMAL/ IS GREATLY LIMITING THE COVERAGE/INTENSITY OF ACCOMPANYING LIGHT SN. THERE HAS BEEN SOME LIGHT SN OVER THE FAR E NEAR NEWBERRY WITH A SW WIND OFF NRN LK MI...BUT THE FLOW HAS NOT BACKED SUFFICIENTLY TO CAUSE THE HEAVIER SN SHOWERS IN MACKINAC COUNTY TO IMPACT LUCE/SCHOOLCRAFT COUNTIES. LOOKING TO THE W...THE 00Z H85/7 TEMPS WERE -17C/-27C AT INL /VS -14C AND -16C AT GRB/. THE 00Z INL IS QUITE MOIST ALMOST UP TO H5 WITHIN A DEEP CYC FLOW. THERE IS A SHARP SFC WSHFT FM W TO NW ALONG A SFC LO PRES TROF RUNNING THRU NRN MN INTO ADJACENT ONTARIO...WITH SFC REPORTS SHOWING SOME MODERATE SN ALONG AND JUST BEHIND THIS BNDRY. MAIN FOCUS IN THE SHORT TERM WL BE ON LES AMOUNTS/GOING HEADLINES ASSOCIATED WITH INCOMING COLD/MOIST AIRMASS. MADE NO CHANGES ATTM TO HEADLINES ISSUED BY THE PREVIOUS SHIFT. TODAY...AS CUTOFF H5 LO DEEPENS FURTHER AND SLIDES SLOWLY TO THE E ACROSS UPR MI...SHARP CYC LLVL FLOW IS FCST TO SLOWLY ENVELOP THE CWA W-E WITH A WSHFT FM WSW EARLY THIS MRNG TO NW BY LATE IN THE DAY EXCEPT OVER THE SE CWA. THE SHARPER LLVL CNVGC WL ARRIVE OVER THE W ARND 12Z AND RESULT IN INCRSG SN RATES DESPITE SOME DEEP LYR QVECTOR DVGC IN THE WAKE OF THE SHRTWV ROTATING THRU THE UPR LKS EARLY THIS MRNG. THE HIER RES MODELS HAVE CONSISTENTLY POINTED TO THE AREA ARND ONTONAGON COUNTY AS THE FOCUS FOR THE SHARPEST CNVGC. GOING START TIME OF 12Z FOR THE WARNINGS OVER THE W APPEARS TO BE ON TRACK. SINCE THE RATHER LO UVV MAX IN THE ABSENCE OF DEEP LYR FORCING WL BE CENTERED IN THE DGZ...EXPECT GOOD SN/WATER RATIOS IN EXCESS OF 20:1 DESPITE A DGZ DEPTH OF ONLY ABOUT 3K FT AND INCRSG WINDS THAT WOULD TEND TO FRAGMENT THE SN FLAKES. WITH SOME INCRSG DEEP LYR QVECTOR CNVGC/UVV OVER THE W HALF LATER IN THE DAY UNDER THE DEEPENING UPR TROF AXIS...FCST SDNGS ALSO INDICATE INCRSG DEEP MSTR THRU THE DAY PER THE 00Z INL RAOB WITH EQUILIBRIUM LVLS APRCHG 10K FT OVER THE BY LATER IN THE DAY AS H85/7 TEMPS DIP TO -16C TO -17C/-27C. INCRSG NW WINDS/DESTABILIZATION WL RESULT IN GUSTY SFC WINDS AND SOME BLSN AS WELL. FARTHER TO THE E...THE LLVL FLOW IS FCST TO BE OUT OF THE W MOST OF THE DAY...SO THE SN SHOWERS THERE SHOULD BE MAINLY CONFINED TO THE LK SHORE UNTIL AT LEAST 21Z...WHEN THE FASTER HI RES CNDN MODEL SHOWS THE ARRIVAL OF SHARPER CYC FLOW/ WSHFT TO THE NW. FCST LES WARNINGS FOR ALGER/NRN SCHOOLCRAFT COUNTIES BEGINS AT 21Z...SO WL NOT CHANGE THIS START TIME. THERE SHOULD BE NOTHING MORE THAN FLURRIES/LIGHT SN SHOWERS OVER THE SCENTRAL WITH DOWNSLOPE FLOW. TNGT...UPR TROF/AXIS OF DEEP LYR QVECTOR CNVGC AND MSTR/SFC LO PRES TROF AND CYC WSHFT TO THE NW ARE PROGGED TO DRIFT SLOWLY E. THESE TRENDS WL RESULT IN INCRSG POPS/SN RATES IN THE NW SN BELTS MAINLY E OF MARQUETTE. THE 00Z NAM AND ESPECIALLY THE HI RES CNDN MODEL HINT LK NIPIGON MOISTENING WL GREATLY ENHANCE SN RATES OVER ALGER/NRN SCHOOLCRAFT COUNTIES...SO THE GOING WRNGS APPEAR ON TRACK. AS WL BE THE CASE TODAY OVER THE W...HI EQUILIBRIUM LVL AND FAVORABLE UVV MAX WITHIN THE DGZ WL BE ENHANCING FACTORS FOR SN RATES IN THIS AREA. ALTHOUGH THE DEPARTURE OF THE DYANAMIC SUPPORT/VERY DEEP MSTR MAY SLOW DOWN THE HEAVY SN RATES OVER THE W BY THE OVERNGT HRS... LINGERING CYC NW BACKING TOWARD THE WNW OVER THE FAR W TOWARD 12Z WL CONTINUE WIDESPREAD SN SHOWERS/CATEGORICAL POPS IN THE FAVORED SN BELTS THERE. ALTHOUGH THE EXPECTED NW FLOW IS NOT FAVORABLE FOR MARQUETTE COUNTY...WL CONTINUE THE ADVY FOR THIS AREA GIVEN POTENTIAL FOR HIER WINDS NEAR THE LK SHORE AND HEAVIER SN IN THE EASTERN PART OF THE COUNTY. ONCE AGAIN...THE LIGHTEST AND LEAST WIDESPREAD SN SHOWERS WL BE OVER THE SCENTRAL. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 444 PM EST MON NOV 17 2014 BY 00Z WEDNESDAY THE 500MB LOW WILL HAVE SHIFTED FROM FAR E ONTARIO TO E QUEBEC...WITH RIDGING AT THE SFC AND ALOFT. THIS WILL ALLOW THE NEAR SFC WINDS TO SHIFT A BIT MORE OUT OF THE W AND SW OVERNIGHT...ALLOWING LES TO PUSH OFFSHORE AND INTO LAKE SUPERIOR. THIS DRY WX WILL BE TEMPORARILY...AS THE NEXT SFC TROUGH AND 500MB SHORTWAVE LOOK TO BE SET UP ACROSS MN ALREADY AT 06Z WEDNESDAY. THERE ISN/T A LOT OF MOISTURE TO WORK WITH INITIALLY. HOWEVER...THE SFC THROUGH WILL SLIDE ACROSS W AND CENTRAL UPPER MI BY 18Z WEDNESDAY...WITH STRONGER DYNAMICS MOVING IN LATER WEDNESDAY AFTERNOON. NW WINDS BEHIND THIS TROUGH DOES NOT LOOK TOO STRONG WEDNESDAY NIGHT INTO THURSDAY /AT LEAST COMPARED TO THE NEARLY 40KTS OF THIS CURRENT SYSTEM/. WINDS ARE MORE ON THE ORDER OF 30KTS ABOVE 900MB. A 500MB LOW ROTATING IN WEDNESDAY NIGHT WILL USHER IN MUCH COOLER AIR...WITH 850MB TEMPS FALLING FROM AN AVERAGE -14C WEDNESDAY AFTERNOON TO AROUND -19C BY THURSDAY AFTERNOON. THE GFS IS A COUPLE DEGREES WARMER ALOFT THAN THE ECMWF VALUES LISTED ABOVE. THIS SHOULD HAVE LITTLE IMPACT ON THE OVERALL TRENDS. CONTINUE TO HIGHLIGHT THE POTENTIAL FOR MODERATE TO HEAVY LAKE EFFECT SNOW SHOWERS LATE WEDNESDAY AFTERNOON/WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. LOOK FOR A CHANGE IN THE PERSISTENT COOL NW FLOW THURSDAY NIGHT...WITH CLEARING CONDITIONS OVER THE INTERIOR W HALF. THIS SHOULD ALLOW SFC TEMPS TO FALL TO AROUND 0F. THE DEEPENING/EXITING SFC LOW OVER S QUEBEC THURSDAY WILL KEEP A TROUGH ACROSS THE UPPER GREAT LAKES INTO THURSDAY EVENING...AS LARGE 500MB TROUGH FINALLY EXITS INTO E CANADA. LOOK FOR LES TO SLOWLY END ONCE AGAIN AS WINDS BECOME A BIT MORE VARIANT...SHIFTING OUT OF THE W. HIGH PRESSURE WILL THEN RETURN TO THE AREA...WITH DRY WEATHER FOR MUCH OF FRIDAY INTO SATURDAY. FRIDAY NIGHT INTO SATURDAY IS A BIT OF A CONUNDRUM...WITH STRONG WAA ON 850MB WINDS OF 40-50KTS FCST OFF BOTH THE 12Z GFS AND ECMWF. WHILE WINTER IS FAR FROM OVER...WE MAY GET A BIT OF A BREAK FROM THE WHITE STUFF. MAY HAVE WAA SHOWERS SATURDAY AFTERNOON IN ADVANCE OF THE SFC TROUGH AND ASSOCIATED SHORTWAVE ACROSS NW MN. AT THIS POINT THE BEST CHANCE FOR A MIX OF RAIN AND SNOW WILL BE ACROSS LAKE MI. WILL NOT GET TOO INTO THE DETAILS FOR SUNDAY AND MONDAY...OTHER THAN TO NOTE THAT MUCH WARMER AIR LOOKS TO PUSH IN FOR SUNDAY. HIGHS COULD TOP OUT IN THE MID TO UPPER 30S...AS S-SSE WINDS CONTINUE IN ADVANCE OF LOW PRESSURE EJECTING OUT OF THE S PLAINS. THE 12Z ECMWF TRACKS A VERY STRONG/WRAPPED UP 927MB SFC LOW ACROSS WI AND UPPER MI SUNDAY NIGHT INTO MONDAY. WHILE THE GFS IS SHOWING A SIMILAR FEATURE...ITS/S TRACK IS ACROSS LOWER MI STARTING OFF AT 989MB AND WEAKENING OVER THIS TIME PERIOD. WILL KEEP A GENERAL BLEND GOING FOR FRIDAY NIGHT AND BEYOND. WOULD NOT BE SURPRISED IF WE NEED TO INCREASE OUR CURRENT WIND FCST FOR THIS PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1216 PM EST MON NOV 17 2014 DEEP MID/UPPER LEVEL TROF AND ASSOCIATED DEEP MOISTURE PUSHING ACROSS THE AREA WILL LEAD TO HEAVIER LAKE EFFECT SNOW SHOWERS AFFECTING KIWD/KCMX UNDER NW FLOW. COMBINATION OF SNOW AND GUSTY NW WINDS CREATING BLSN WILL LIKELY RESULT IN LIFR CONDITIONS PREVAILING AT BOTH TERMINALS. AS DEEPER MOISTURE BEGINS TO EXIT...EXPECT IMPROVEMENT TO IFR LATE TONIGHT/EARLY TUE MORNING AND THEN TO MVFR BY TUE AFTN. AT KSAW...NW WIND DIRECTION WILL NOT BE FAVORABLE FOR ANYTHING MORE THAN -SHSN AT TIMES. MVFR CIGS WILL DEVELOP THIS AFTN AND CONTINUE THRU THE REMAINDER OF THE FCST PERIOD. THERE MAY BE A FEW PERIODS OF MVFR VIS IN -SHSN LATER THIS AFTN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 646 AM EST MON NOV 17 2014 LOW PRESSURE OVER FAR NORTHERN LAKE SUPERIOR WILL SHIFT EAST TODAY...SWEEPING A SURFACE TROUGH SOUTHEAST ACROSS LAKE SUPERIOR TODAY. BEHIND THE TROUGH...LOOK FOR GUSTS TO INCREASE TO GALES OF 35-40KTS OVER PORTIONS OF W LAKE SUPERIOR THIS AFTERNOON...BEFORE EXPANDING TO THE E HALF OF LAKE SUPERIOR THIS EVENING THROUGH EARLY TUESDAY. THE TIMING OF THE GALE WARNING WAS IN GOOD SHAPE AND WILL CONTINUE. A TROUGH WILL THEN LINGER ACROSS LAKE SUPERIOR THROUGH TUESDAY MORNING...BEFORE BRIEFLY BEING REPLACED BY A RIDGE TUESDAY AFTERNOON AND EVENING. ANOTHER TROUGH OVER N MANITOBA ON TUESDAY WILL SLIDE ACROSS THE UPPER GREAT LAKES LATE TUESDAY NIGHT THROUGH WEDNESDAY...BEFORE EXITING ACROSS THE ONTARIO AND QUEBEC BORDER THURSDAY MORNING. A FEW NORTHWEST GALE FORCE GUSTS TO 35 KNOTS ARE POSSIBLE OVER EASTERN LAKE SUPERIOR LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. HIGH PRESSURE OVER THE N PLAINS ON THURSDAY WILL DIVE ACROSS THE OHIO VALLEY LATE FRIDAY...EXTENDING A RIDGE OVER THE UPPER GREAT LAKES ON FRIDAY AND DIMINISHING WINDS BELOW 25 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ TUESDAY FOR MIZ001>003-009-084. LAKE EFFECT SNOW WARNING UNTIL 7 PM EST TUESDAY FOR MIZ006-085. LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ007. LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ004-005. LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ014. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 1 PM EST TUESDAY FOR LSZ251-267. GALE WARNING UNTIL 1 PM EST TUESDAY FOR LSZ248>250-265-266. GALE WARNING UNTIL 9 AM EST TUESDAY FOR LSZ264. GALE WARNING UNTIL 4 AM EST /3 AM CST/ TUESDAY FOR LSZ240>242- 263. GALE WARNING UNTIL 7 AM EST TUESDAY FOR LSZ243>245. GALE WARNING UNTIL 1 AM EST /MIDNIGHT CST/ TUESDAY FOR LSZ162. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...ROLFSON MARINE...SRF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
135 PM EST MON NOV 17 2014 .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 LOW PRESSURE PASSING TO OUR NORTH TODAY...WILL USHER IN ANOTHER SURGE OF COLD AIR. LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN SOME PLACES TODAY...BUT HEAVY SNOW IS EXPECTED TONIGHT AND TUESDAY IN SOME OF THE CLASSIC SNOWBELTS. ANOTHER SYSTEM WILL BRING LIGHT SNOW TO THE REGION WEDNESDAY...AND MORE LAKE EFFECT SNOW WILL FOLLOW BEHIND IT. HOWEVER...TEMPERATURES WILL BECOME MILDER DURING THE UPCOMING WEEKEND. && .UPDATE... ISSUED AT 112 PM EST MON NOV 17 2014 THINGS SEEM TO BE ON TRACK FOR THE FORECAST WITH THE BANDS REALIGNING IN SOME KIND OF W OR WNW BAND BASED ON THE KAPX RADAR AND VIS SATELLITE IMAGE. IN E UPPER A DOMINATE W BAND HAS FORMED IS JUST OFF THE SHORE AT WHITEFISH POINT. SO WILL MAKE SOME MINOR TWEAKS TO WEATHER AND SNOW AMOUNTS, BUT LITTLE WILL CHANGE FOR THE NEXT COUPLE OF HOURS. UPDATE ISSUED AT 1013 AM EST MON NOV 17 2014 THE FRONT IS MAKING ITS WAY FROM N LAKE MICHIGAN TO NW LOWER. THIS HAS LEAD TO THE SW SNOW BANDS MERGING AND FLARING UP AS THEY MOVE INLAND. THIS WILL LEAD TO TO BRIEFLY HEAVY SNOW AS THE BANDS TRANSIT THE REGION OVER THE NEXT COUPLE OF HOURS. WILL EXPECT THAT THE BANDS WILL LOSE THEIR INTENSITY AS THEY MOVE EAST AWAY FROM THE LAKE. BEHIND THE FRONT, THE SNOW BANDS ARE ALREADY REFORMING WITH THE WEST WIND OVER THE N LAKE MICHIGAN. WILL BE EXPECTING THAT THE SNOW BANDS WILL REESTABLISH QUICKLY, BUT THE WHETHER THEY WILL REMAIN STATIONARY OR BE TRANSIENT OVER THE AFTERNOON IS UNCERTAIN AS THE MODELS HAVE VARYING SOLUTIONS WITH A SPREAD OF ABOUT 30 DEGREES IN THE 1000-850 MB WIND DIRECTIONS. WILL CONTINUE THE GOING AFTERNOON FORECAST UNTIL THE BANDS SHOW THEIR INTENTIONS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 331 AM EST MON NOV 17 2014 ...SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED LATER TODAY THROUGH TUESDAY... HIGH IMPACT WEATHER POTENTIAL: LOCALIZED VERY HEAVY LAKE EFFECT SNOW. AREAS OF BLOWING SNOW AND NEAR WHITEOUT CONDITIONS POSSIBLE TONIGHT. PATTERN SYNOPSIS/CURRENT CONDITIONS: KINDA STATING THE OBVIOUS...BUT MID-WINTER LIKE PATTERN WELL ESTABLISHED ACROSS THE NORTHERN LAKES. REASON FOR SUCH IS ONE ANOMALOUSLY DEEP MERIDIONAL FLOW REGIME...CONSISTING OF FULL LENGTH WESTERN NOAM RIDGING AND JUST AS IMPRESSIVE TROUGHING EXTENDING THROUGH THE CENTRAL PLAINS INTO THE WESTERN LAKES. MOST IMPRESSIVE COLD SURGE YET TIED TO WAVE OF ARCTIC ORIGIN DIVING INTO SOUTHWEST ONTARIO AND INTO MINNESOTA (-20C H8 TEMPERATURES PER LATEST RAP ANALYSIS!). SURFACE COLD FRONT RUNNING WELL AHEAD OF THIS WAVE...ALREADY PUSHING INTO NORTHWEST MICHIGAN AT THIS EARLY HOUR. AREA OUT AHEAD OF THIS FRONT PLENTY COLD ENOUGH TO CONTINUE TO ENTICE A SIGNIFICANT LAKE RESPONSE (A PRETTY RARE FEAT TO HAVE SUCH COLD PRE-FRONTAL AIR DURING MID NOVEMBER). MAIN SHOW TONIGHT HAS BEEN DIRECTED INTO PARTS OF EASTERN UPPER MICHIGAN.. WHERE NO DOUBT SEVERAL INCHES OF ACCUMULATION HAVE ALREADY OCCURRED. SOMEWHAT LIGHTER MORE NUISANCE TYPE SNOWS IMPACTING NORTHER LOWER...ALTHOUGH SOME EMBEDDED HEAVIER LAKE ENHANCED SNOWS WERE NOTED...ESPECIALLY ACROSS PARTS OF EMMET COUNTY. SIMPLY NO END IN SIGHT...WITH CURRENT UPSTREAM WAVE SET TO AMPLIFY OVERHEAD LATER TODAY AND TONIGHT...FORCING A SHIFTING OF THE WINDS TO MORE W/NW AND PUTTING THE MORE TRADITIONAL LAKE EFFECT AREAS UNDER THE GUN FOR A HIGH IMPACT WINTER WEATHER EVENT. PRIMARY FORECAST CONCERNS/CHALLENGES: MULTIPLE! INITIAL FOCUS ON ONGOING SW FLOW LAKE EFFECT AND ASSOCIATED HEADLINES THIS MORNING. OVERNIGHT FOCUS ON MUCH MORE WIDESPREAD LAKE SNOW EVENT...INCLUDING AMOUNTS AND HEADLINE MANAGEMENT CONCERNS. DETAILS: NOT PRETTY! FIRST OFF...ONGOING SW FLOW LAKE SNOWS SHOULD STEADILY DECLINE IN INTENSITY SHORTLY AFTER 09Z AS WINDS BEGIN TO SLOWLY VEER AND BRIEF CORRIDOR OF UPSTREAM DRIER AIR OVERSPEADS THE LAKES. CURRENT HEADLINES RUN THROUGH 15Z...WHICH OFFERS SOME FLEXIBILITY IF BANDS SHOULD PERSIST LONGER THAN ANTICIPATED (NEVER SEEN THAN BEFORE :)). NO OFFICIAL REPORTS JUST YET...BUT BASED OFF MACKINAC BRIDGE WEB CAMS AND SOME INFORMATION GLEANED FROM CALLING ST. IGNACE...GOTTA FEELING WE WILL BE DEALING WITH SOME IMPRESSIVE SNOWFALL TOTALS UP IN THE STRAITS AREA BEFORE ALL IS SAID AND DONE THIS MORNING. ELSEWHERE...JUST SOME LIGHTER SNOWS EXPECTED AS THE COLD FRONT PUSHES EAST...EXITING STAGE RIGHT BY MID-MORNING. WITH PART ONE DONE...ALL FOCUS SHIFTS TO WHAT INCREASINGLY LOOKS LIKE A VERY SIGNIFICANT AND PROLONGED LAKE EFFECT EVENT FOR THE MORE TRADITIONAL SNOW BELTS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN. CURRENT SOUTHWEST ONTARIO WAVE CONTINUES TO DIG...SLOWLY CROSSING THE NORTHERN LAKES THROUGH THE OVERNIGHT. DESPITE MAIN CORE OF ATTENDANT CAA ACTUALLY PASSING US BY TO THE SOUTH...INSTABILITY RAMPS UP IMPRESSIVELY LATE TODAY THROUGH THE OVERNIGHT...WITH NEAR EXTREME DELTA T/S COLLOCATED WITH DEEP SYNOPTIC MOISTURE SUPPORT AND ESSENTIALLY ALL LOSS OF AN INVERSION. CYCLONIC FLOW IS IMPRESSIVE... SUGGESTING ENHANCED CONVERGENCE TARGETING NORTHWEST LOWER MICHIGAN. LOW LEVEL FLOW IS SLIGHTLY MORE BACKED IN RECENT GUIDANCE RUNS...WELL SUPPORTED BY WHAT SHOULD BE STRENGTHENING LAKE DRIVEN SURFACE TROUGH DEVELOPMENT. AFTER A BRIEF BREAK THIS AFTERNOON... EXPECT SNOWS TO GET GOING IN EARNEST THIS EVENING...WITH INITIAL FOCUS IN FAVORED WEST FLOW AREAS...WITH A SLIGHT SOUTHWARD TREND EXPECTED DURING THE OVERNIGHT TOWARD THE M-32 CORRIDOR. SNOWFALL AMOUNTS COULD BE QUITE IMPRESSIVE...WITH STRONG OMEGA CENTERED RIGHT IN PRIME DGZ RIGHT THROUGH THE OVERNIGHT. DESPITE SOME FRAGMENTATION OF FLAKES FROM VERY GUSTY WINDS (MORE ON THE WINDS TO FOLLOW)...EXPECT SNOW TO LIQUID RATIOS TO PUSH 20 TO 1...PERHAPS EVEN HIGHER IF STRONG LOW LEVEL CONVERGENCE UNDER BANDS HELP SLACKING THE WIND FIELDS. SLIGHT SOUTHWARD DRIFT LOOKS TO BE THE ONLY THING FROM PREVENTING SNOW AMOUNTS FROM GETTING TOO OUT OF HAND. STILL...COULD EASILY SEE PARTS OF CHARLEVOIX/ANTRIM/OTSEGO/EMMET/CHEBOYGAN COUNTIES EXCEEDING 8 INCHES BY MORNING...WITH THE HIGHEST AMOUNTS JUST DOWNWIND OF LITTLE TRAVERSE BAY. ANY SLOWER DRIFT OF BANDS THAN CURRENTLY ANTICIPATED WILL RESULT IN LOCALLY HIGHER AMOUNTS. FURTHER SOUTH...COMPLETE LACK OF A LAKE SUPERIOR CONNECTION REALLY SHORTENS THE EFFECTIVE FETCH LENGTH. SO...DESPITE EXCELLENT INSTABILITY...JUST NOT SEEING THE OPPORTUNITY FOR A WHOLE LOT OF ACCUMULATION ALONG AND SOUTH OF THE M- 72 CORRIDOR. HOWEVER...GUSTY WINDS OF 20 TO 30 MPH WILL MAKE FOR SOME NASTY CONDITIONS...CREATING AREAS OF BLOWING AND DRIFTING SNOW AND BRIEF PERIODS OF VERY LOW VISIBILITIES. OFF LAKE SUPERIOR: INITIAL FOCUS THIS EVENING LOOKS TO REMAIN WEST OF WHITEFISH POINT...REALLY TARGETING AREAS OVER NEAR MUNISING AND SENEY. WINDS BEGIN TO SHIFT MORE W/NW LATE...BRINGING ACCUMULATING SNOW BANDS INTO NORTHWEST CHIPPEWA COUNTY. LATER START AND SIGNALS FOR BEST LOW LEVEL CONVERGENCE TO REMAIN OFF TO THE WEST SUGGESTS LOWER SNOW TOTALS THAN THOSE TO THE SOUTH...WITH 2 TO 4 INCHES EXPECTED BY MORNING. STRONG WINDS WILL PUSH BANDS FURTHER INLAND THAN WHAT IS NORMAL...PERHAPS EVEN BRINGING PARTS OF NORTHWEST MACKINAC COUNTY SEVERAL INCHES BY MORNING. MORE SNOW WILL FALL IN ALL THE ABOVE AREAS TOMORROW...WITH SEVERAL MORE INCHES EXPECTED (SEE LONG TERM SECTION BELOW). HEADLINES: FOR NORTHERN LOWER...GIVEN GUSTY WINDS AND WHAT COULD BE WIDESPREAD BLOWING SNOW EVEN OUTSIDE THE BETTER SNOW BANDS...HAVE DECIDED TO FORGO THE SPECIFIC LAKE EFFECT HEADLINES FOR MORE GENERIC WINTER WEATHER HEADLINES. HIGHEST SNOW TOTAL AREA MENTIONED EARLIER WILL BE UPGRADED TO A WINTER STORM WARNING...STARTING AT 00Z THIS EVENING RUNNING RIGHT THROUGH TUESDAY. WINTER WEATHER ADVISORIES SHOULD DO FOR AREAS SOUTH OF M-72...AS WELL AS PARTS OF NORTHEAST LOWER AS STRONG WINDS HELP PUSH WEAKENING BANDS FAR INLAND. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 331 AM EST MON NOV 17 2014 HIGH IMPACT WEATHER POTENTIAL...PLENTY OF SNOW AND COLD DURING THE WORK WEEK. HEAVY LAKE EFFECT SNOW IN WNW/NW FLOW TUESDAY. SOME POTENTIAL FOR HEAVY LAKE EFFECT SNOW WED NIGHT TO THU NIGHT. TUESDAY...UPPER LOW WILL EJECT FROM NORTH OF LAKE HURON INTO EASTERN QUEBEC. ONE TRAILING SHORTWAVE WILL CROSS CENTRAL LOWER MI IN THE AFTERNOON...ANOTHER WEAK WAVE WILL DIG TOWARD EASTERN SUPERIOR. A 980MB SURFACE LOW STARTS THE MORNING IN CENTRAL QUEBEC...AND WILL ADVANCE NE. SUBSTANTIAL TROFFING LINGERS ACROSS THE AREA EARLY IN THE MORNING...THIS RELAXES AS THE UPPER LOW PULLS OUT...BUT LAKE- INDUCED TROFFING REMAINS EVIDENT THRU THE DAY. 1000-850MB WINDS REMAIN STEADY-STATE IN THE MORNING...WNW INTO NORTHERN LOWER AND NW INTO EASTERN UPPER. WINDS WILL BACK SOME DURING THE AFTERNOON...BY EARLY EVENING WE WILL SEE A W FETCH INTO NORTHERN LOWER AND WNW INTO EASTERN UPPER. PLENTY OF DEEP MOISTURE...HIGH INVERSION HEIGHTS (TO NEARLY 500MB)...AND DELTA T/S NEAR 20C SHOULD ENSURE RAMPAGING LAKE EFFECT SNOW IN THE MORNING HOURS. IN THE AFTERNOON...THE INVERSION LOWERS TOWARD 700MB WITH DRYING ALOFT. THAT WILL REDUCE SNOW INTENSITY SOMEWHAT...BUT BY AND LARGE PARAMETERS AND STILL VERY FAVORABLE. AS IS THE CASE FOR TONIGHT...THE LOW-LEVEL FLOW IS A LITTLE BACKED COMPARED TO PREVIOUS RUNS. IN NORTHERN LOWER...THIS REQUIRES ADJUSTING THE MAX SNOW TOTALS NORTHWARD SLIGHTLY. CHARLEVOIX/ANTRIM/OTSEGO ARE THE MAIN ONES UNDER THE GUN...BUT THE FETCH NOW SUPPORTS MORE SNOW IN SOUTHERN EMMET/CHEBOYGAN THAN IT DOES IN NORTHERN KALKASKA/CRAWFORD. 5-9 INCHES STILL LIKES A GOOD FORECAST FOR THE DAY IN THE HARDEST-HIT LOCALES...CENTERED ON ELMIRA. 1-4 INCHES WORKS ELSEWHERE IN NW LOWER...WHERE THE FETCH IS MUCH SHORTER AND HAS NO CONNECTION TO SUPERIOR. IN EASTERN UPPER...THE BACKED FLOW OPENS UP MORE OF CHIPPEWA...BUT SHOULD STILL KEEP THE STRONGEST BANDS WEST OF THE SAULT. BUT THINGS ARE LOOKING CONSIDERABLY MORE FAVORABLE UP THERE...AND WILL INCREASE WESTERN CHIP AND FAR NW MACK INTO THE 3-5 INCH RANGE. MAX TEMPS WILL BE MAINLY IN THE 20S. HOWEVER...IN THE HIGH TERRAIN IN THE SOUTH...WHERE MARINE MODIFICATION WILL BE SMALLER DUE TO THE SHORTER FETCH...SOME PLACES (LIKE CAD) WILL LIKELY NOT ESCAPE THE TEENS. (HARD TO BELIEVE IT/S ONLY MID-NOVEMBER.) TUE NIGHT/WED...NOT MUCH REST FOR THE SNOW-WEARY. CLIPPER SHORTWAVE WILL ADVANCE INTO THE WESTERN LAKES ON WED. ASSOCIATED SURFACE LOW WILL ADVANCE FROM THE UPPER MS VALLEY TO NORTHERN LOWER MI ON WED. LOW LEVEL FLOW WILL BACK TO THE SW TUE NIGHT...WITH MOISTENING OVERNIGHT. SOME POTENTIAL FOR SOME SNEAKY 1-3 INCH ACCUMS OVER THE TIP OF NORTHERN LOWER TUE EVENING. SYNOPTIC -SN MIGHT SNEAK INTO SW SECTIONS LATE TUE NIGHT...BUT THE BULK OF THE THAT WILL WAIT UNTIL WED. BY THEN...A SOUTH 1000-850MB FETCH SHOULD KEEP MOST OF THE LAKE- INDUCED NONSENSE AT BAY...OTHER THAN ALONG THE SOUTH SHORE OF UPPER MI (AND IT IS UNCERTAIN WHETHER SYNOPTIC PRECIP WILL MAKE IT THAT FAR NORTH). THIS SYSTEM DOES NOT LOOK LIKE A MAJOR PROBLEM...1-2 INCHES...ESPECIALLY SOUTH OF M-32. MIN TEMPS TEENS TO PERHAPS HIGH SINGLE DIGITS (YIKES). MAX TEMPS 20S. REST OF THE FORECAST...POST-CLIPPER LAKE EFFECT SNOW WILL OCCUR WED NIGHT INTO THU NIGHT...AIDED BY ANOTHER CLIPPER SHORTWAVE DROPPING IN FROM THE NW. THE SET-UP FOR HEAVY SNOW LOOKS BETTER IN EASTERN UPPER IN THIS EVENT...AS DEEPER MOISTURE WILL LINGER LONGER THERE VS MID-LEVEL DRY AIR TRYING TO ENTRAIN INTO THE SOUTHER/CENTRAL LAKES. REGARDLESS...LAKE EFFECT SHSN WILL AGAIN BE FAIRLY WIDESPREAD IN BOTH PENINSULAS. THOUGH THE MODELS TEND TO BE TOO FAST TO BREAK PATTERNS DOWN...ALL MODELS HAVE THE CURRENT ONE FALL APART AFTER THIS LAST CLIPPER. 500MB FLOW BECOMES CONSIDERABLY MORE ZONAL...AND MORE SEASONABLE AIR WILL FINALLY GET A CHANCE TO MOVE INTO THE REGION...ESPECIALLY BY THE TAIL END OF THE WEEKEND. A SOUTHERN STREAM SYSTEM MOVING INTO THE CENTRAL STATES WILL AMPLIFY WARM ADVECTION...AND INCREASE PRECIP CHANCES BY SUNDAY. THIS ACTUALLY LOOKS TO BE MOSTLY RAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 112 PM EST MON NOV 17 2014 WINDS ARE NOW MORE WEST AND WITH IT, THE SNOW BANDS ARE ALIGNING THEMSELVES WITH THE WIND SO THE MAIN ISSUE IS THE ENDING OF THE HEAVY SNOW AT PLN AND FINDING THE RIGHT MIX OF PREVAILING AND TEMPO GROUPS FOR TVC AND MBL. APN LOOKS TO BE IN GOOD SHAPE WITH VFR CONDITIONS EXPECTED THROUGH 12Z TUES. WINDS LOOK TO TURN MORE BACK FROM NNW TO NW BETWEEN 12Z AND 18Z SO THAT SNOW BANDS WILL SHIFT THROUGH APN DURING THE MORNING. TO SUMMARIZE, PLN, TVC, AND MBL, WILL HAVE MVFR CIGS AND VSBYS AS THE SNOW BANDS CONTINUE, WITH OCCASIONAL VFR OR IFR DEPENDING ON BAND MOVEMENT AND INTENSIFICATION. APN WILL MAINLY BE VFR, WITH OCCASIONAL MVFR VSBYS AS SNOW BANDS MOVE OVER THE TAF SITE, BUT THAT WILL MAINLY BE TUESDAY MORNING. && .MARINE... ISSUED AT 331 AM EST MON NOV 17 2014 STRONG SURGE OF CAA AND INCREASINGLY SHARP PRESSURE GRADIENT WILL BRING VERY GUSTY WINDS BY LATER TODAY RIGHT THROUGH TUESDAY. GREATEST IMPACT EXPECTED ACROSS NORTHERN LAKE MICHIGAN...WHERE GALE FORCE WEST WINDS ARE EXPECTED TO DEVELOP QUICKLY THIS EVENING. SCA CONDITIONS EXPECTED ELSEWHERE...ALTHOUGH WILL NEED TO BE ON THE LOOKOUT FOR SOME GALE GUSTS ALONG THE NORTHEAST LOWER COASTLINE. WINDS ARE EXPECTED TO SUBSIDE LATE TUESDAY...AND ESPECIALLY TUESDAY NIGHT. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY FOR MIZ018-020-023-025>028-031>033. WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY FOR MIZ016-017-019-021-022. WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR MIZ008. LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LMZ341. GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LMZ323-342-344>346. LS...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EST TUESDAY FOR LSZ321-322. && $$ UPDATE...JSL SYNOPSIS...JAZ SHORT TERM...MSB LONG TERM...JAZ AVIATION...JSL MARINE...MSB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1217 PM EST MON NOV 17 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EST MON NOV 17 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS INDICATE A DEEPENING UPR TROF OVER CENTRAL NAMERICA WITH CLOSED H5 LO OVER ONTARIO JUST NW OF LK SUP CAUSING 12HR H5 HGT FALLS UP TO 130M BTWN 16/12Z AND 17/00Z AT INL AND DRAWING H5 TEMPS CLOSE TO -40C S UNDER THE AXIS OF LOWEST HGTS. BAND OF DPVA/DEEP LYR QVECTOR CNVGC/AXIS OF MID LVL MSTR IN ADVANCE OF SHRTWV ROTATING ARND THE CLOSED LO IS CROSSING UPR MI EARLY THIS MRNG...BUT DRYNESS OF AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.16 INCH IS 45 PCT OF NORMAL/ IS GREATLY LIMITING THE COVERAGE/INTENSITY OF ACCOMPANYING LIGHT SN. THERE HAS BEEN SOME LIGHT SN OVER THE FAR E NEAR NEWBERRY WITH A SW WIND OFF NRN LK MI...BUT THE FLOW HAS NOT BACKED SUFFICIENTLY TO CAUSE THE HEAVIER SN SHOWERS IN MACKINAC COUNTY TO IMPACT LUCE/SCHOOLCRAFT COUNTIES. LOOKING TO THE W...THE 00Z H85/7 TEMPS WERE -17C/-27C AT INL /VS -14C AND -16C AT GRB/. THE 00Z INL IS QUITE MOIST ALMOST UP TO H5 WITHIN A DEEP CYC FLOW. THERE IS A SHARP SFC WSHFT FM W TO NW ALONG A SFC LO PRES TROF RUNNING THRU NRN MN INTO ADJACENT ONTARIO...WITH SFC REPORTS SHOWING SOME MODERATE SN ALONG AND JUST BEHIND THIS BNDRY. MAIN FOCUS IN THE SHORT TERM WL BE ON LES AMOUNTS/GOING HEADLINES ASSOCIATED WITH INCOMING COLD/MOIST AIRMASS. MADE NO CHANGES ATTM TO HEADLINES ISSUED BY THE PREVIOUS SHIFT. TODAY...AS CUTOFF H5 LO DEEPENS FURTHER AND SLIDES SLOWLY TO THE E ACROSS UPR MI...SHARP CYC LLVL FLOW IS FCST TO SLOWLY ENVELOP THE CWA W-E WITH A WSHFT FM WSW EARLY THIS MRNG TO NW BY LATE IN THE DAY EXCEPT OVER THE SE CWA. THE SHARPER LLVL CNVGC WL ARRIVE OVER THE W ARND 12Z AND RESULT IN INCRSG SN RATES DESPITE SOME DEEP LYR QVECTOR DVGC IN THE WAKE OF THE SHRTWV ROTATING THRU THE UPR LKS EARLY THIS MRNG. THE HIER RES MODELS HAVE CONSISTENTLY POINTED TO THE AREA ARND ONTONAGON COUNTY AS THE FOCUS FOR THE SHARPEST CNVGC. GOING START TIME OF 12Z FOR THE WARNINGS OVER THE W APPEARS TO BE ON TRACK. SINCE THE RATHER LO UVV MAX IN THE ABSENCE OF DEEP LYR FORCING WL BE CENTERED IN THE DGZ...EXPECT GOOD SN/WATER RATIOS IN EXCESS OF 20:1 DESPITE A DGZ DEPTH OF ONLY ABOUT 3K FT AND INCRSG WINDS THAT WOULD TEND TO FRAGMENT THE SN FLAKES. WITH SOME INCRSG DEEP LYR QVECTOR CNVGC/UVV OVER THE W HALF LATER IN THE DAY UNDER THE DEEPENING UPR TROF AXIS...FCST SDNGS ALSO INDICATE INCRSG DEEP MSTR THRU THE DAY PER THE 00Z INL RAOB WITH EQUILIBRIUM LVLS APRCHG 10K FT OVER THE BY LATER IN THE DAY AS H85/7 TEMPS DIP TO -16C TO -17C/-27C. INCRSG NW WINDS/DESTABILIZATION WL RESULT IN GUSTY SFC WINDS AND SOME BLSN AS WELL. FARTHER TO THE E...THE LLVL FLOW IS FCST TO BE OUT OF THE W MOST OF THE DAY...SO THE SN SHOWERS THERE SHOULD BE MAINLY CONFINED TO THE LK SHORE UNTIL AT LEAST 21Z...WHEN THE FASTER HI RES CNDN MODEL SHOWS THE ARRIVAL OF SHARPER CYC FLOW/ WSHFT TO THE NW. FCST LES WARNINGS FOR ALGER/NRN SCHOOLCRAFT COUNTIES BEGINS AT 21Z...SO WL NOT CHANGE THIS START TIME. THERE SHOULD BE NOTHING MORE THAN FLURRIES/LIGHT SN SHOWERS OVER THE SCENTRAL WITH DOWNSLOPE FLOW. TNGT...UPR TROF/AXIS OF DEEP LYR QVECTOR CNVGC AND MSTR/SFC LO PRES TROF AND CYC WSHFT TO THE NW ARE PROGGED TO DRIFT SLOWLY E. THESE TRENDS WL RESULT IN INCRSG POPS/SN RATES IN THE NW SN BELTS MAINLY E OF MARQUETTE. THE 00Z NAM AND ESPECIALLY THE HI RES CNDN MODEL HINT LK NIPIGON MOISTENING WL GREATLY ENHANCE SN RATES OVER ALGER/NRN SCHOOLCRAFT COUNTIES...SO THE GOING WRNGS APPEAR ON TRACK. AS WL BE THE CASE TODAY OVER THE W...HI EQUILIBRIUM LVL AND FAVORABLE UVV MAX WITHIN THE DGZ WL BE ENHANCING FACTORS FOR SN RATES IN THIS AREA. ALTHOUGH THE DEPARTURE OF THE DYANAMIC SUPPORT/VERY DEEP MSTR MAY SLOW DOWN THE HEAVY SN RATES OVER THE W BY THE OVERNGT HRS... LINGERING CYC NW BACKING TOWARD THE WNW OVER THE FAR W TOWARD 12Z WL CONTINUE WIDESPREAD SN SHOWERS/CATEGORICAL POPS IN THE FAVORED SN BELTS THERE. ALTHOUGH THE EXPECTED NW FLOW IS NOT FAVORABLE FOR MARQUETTE COUNTY...WL CONTINUE THE ADVY FOR THIS AREA GIVEN POTENTIAL FOR HIER WINDS NEAR THE LK SHORE AND HEAVIER SN IN THE EASTERN PART OF THE COUNTY. ONCE AGAIN...THE LIGHTEST AND LEAST WIDESPREAD SN SHOWERS WL BE OVER THE SCENTRAL. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 646 AM EST MON NOV 17 2014 UPPER TROUGH THAT IS IN THE PROCESS OF MOVING OVER THE AREA TODAY WILL BE STARTING TO MOVE OUT OF THE AREA WHILE A WEAK SURFACE RIDGE OVER THE NORTHERN PLAINS SHIFTS EAST INTO THE UPPER GREAT LAKES REGION. MODERATE TO HEAVY SNOW WILL BE ONGOING OVER PORTIONS OF THE CWA...ESPECIALLY OVER THE EAST (ALGER AND NORTHERN SCHOOLCRAFT COUNTIES) WHERE THE NORTHWEST FLOW LAKE EFFECT WILL BE AIDED BY LOW LEVEL WINDS STARTING TO BACK IN RESPONSE TO THE SURFACE RIDGE AND INCREASING CONVERGENCE. EXPECT THE FAVORABLE CONDITIONS TO CONTINUE THROUGH THE MORNING OVER THE EAST...BEFORE THE DRYING AND LOWERING INVERSION HEIGHTS SEEN OVER THE WEST DURING THE MORNING...MOVES INTO THE AREA AND DIMINISHES THE INTENSITY OF THE LAKE EFFECT. WINDS WILL ALSO BE STEADILY BACKING THROUGH THE DAY...TO THE SOUTHWEST OVER THE WESTERN CWA AND WESTERLY OVER THE EASTERN CWA BY THE EVENING HOURS TUESDAY. THUS...WOULD EXPECT TRANSIENT BANDS BECOMING FOCUSED OVER THE KEWEENAW PENINSULA AND NEAR LAKE SUPERIOR EAST OF PICTURED ROCKS. AS FOR SNOWFALL ACCUMULATION...HAVE ANOTHER 3-5 INCHES NORTHWEST OF A LINE FROM DEERTON TO MANISTIQUE AND ANOTHER 1-3 INCHES OVER THE TRADITIONAL AREAS OVER THE WEST. TUESDAY EVENING...COULD SEE ANOTHER 1-2 INCHES AS THE LAKE EFFECT TRANSITIONS NORTH ACROSS THE KEWEENAW PENINSULA BEFORE IT MOVES OFFSHORE. ALSO ON TUESDAY NIGHT...A SHORTWAVE WILL DIVE SOUTHEAST FROM CENTRAL CANADA...THROUGH NORTHERN MINNESOTA AND INTO WISCONSIN. AT THE SURFACE...A BROAD TROUGH WILL QUICKLY DROP INTO THE AREA AND BRING MORE VARIABLE LOW LEVEL WINDS TO THE AREA. WILL CONTINUE TO SHOW SLIGHT AND LOW CHANCE POPS FOR AREAS NEAR THE WISCONSIN BORDER LATE TUESDAY NIGHT. THIS COULD CONTINUE INTO WEDNESDAY FOR MUCH OF THE AREA AS BROAD MID LEVEL Q-VECTOR CONVERGENCE CONTINUES ALTHOUGH MUCH OF THE AREA WILL BE BETWEEN THE INITIAL SHORTWAVE MOVING INTO LOWER MICHIGAN AND THE SECONDARY SHORTWAVE DROPPING INTO NORTHWEST WISCONSIN LATE WEDNESDAY AFTERNOON. THUS...WILL SHOW SOME POTENTIAL FOR LIGHT SNOW SHOWERS ON WEDNESDAY. ALSO ON WEDNESDAY...COULD SEE LAKE EFFECT OFF LAKE MICHIGAN OVER SOUTHEAST LUCE COUNTY ON WEDNESDAY AFTERNOON AS LOW LEVEL WINDS BACK FAR ENOUGH TO THE SOUTH-SOUTHWEST TO PUSH THE BAND INTO THAT AREA. THEN AS WINDS SHIFT TO THE WEST-NORTHWEST BEHIND A SECONDARY SURFACE TROUGH...EXPECT THE LAKE EFFECT SNOW TO PICKUP IN THE KEWEENAW FIRST (WEDNESDAY AFTERNOON) AND THEN SPREAD OVER THE REST OF THE NORMAL WEST-NORTHWEST FAVORED LOCATIONS OVER THE WEST DURING THE EVENING AND EAST OVERNIGHT. WINDS ON THURSDAY WILL DEPEND ON THE TRAILING SURFACE TROUGH ATTEMPTING TO HOLD OVER EASTERN LAKE SUPERIOR. MODELS VARY ON ITS LOCATION LATE WEDNESDAY NIGHT INTO THURSDAY AND HOW QUICKLY IT DEPARTS. DUE TO THESE DIFFERENCES...THE FINER DETAILS ARE HARD TO PIN DOWN AND WILL FOCUS ON GENERAL NORTHWEST WIND LAKE EFFECT FOR THE TIME BEING. STILL EXPECT VERY FAVORABLE LAKE EFFECT CONDITIONS (DELTA-T VALUES AROUND 23) BUT LAKE INDUCED EQUILIBRIUM VALUES WILL BE 5KFT LOWER THAN TONIGHT (UP TO 13KFT) AND LAKE INDUCED CAPE VALUES WILL PEAK AROUND 800 J/KG. WINDS DO LOOK TO BE WEAKER DURING THIS PERIOD...WHICH WOULD LEAD TO LESS FRACTURING OF THE DENDRITES...BUT DO HAVE A LITTLE CONCERN THAT THE TOP HALF OF THE CLOUD WILL BE ABOVE THE DGZ AND SUPPORT MORE COLUMNS IN THE SNOW AND LEAD TO LOWER RATIOS. THUS...WILL STICK WITH SNOW RATIOS AROUND OR JUST ABOVE 20-1 AT THIS POINT AND WILL BE ABLE TO FINE TUNE WITH FUTURE SHIFTS. THIS PRODUCES SNOWFALL AMOUNTS OF 5 TO 11 INCHES IN THE NORTHWEST TO WEST-NORTHWEST WIND SNOW BELTS FOR WEDNESDAY AFTERNOON INTO THURSDAY EVENING. CURRENT THINKING IS A GENERAL LES ADVISORY WILL BE NEEDED AT SOME POINT (UNLESS INCREASED CONVERGENCE OCCURS ALONG THE TRAILING SURFACE TROUGH) AND WILL CONTINUE TO HIGHLIGHT IN THE HWO/EHWO. UPPER TROUGH WILL BEGIN TO SHIFT EAST AND OUT OF THE AREA ON THURSDAY...ALLOWING AN UPPER RIDGE TO BUILD TOWARDS THE AREA THURSDAY NIGHT AND IN TURN A SURFACE RIDGE. THIS WILL GRADUALLY WEAKEN THE LAKE EFFECT ON THURSDAY NIGHT INTO FRIDAY AS INVERSION HEIGHTS STEADILY FALL AND WINDS BACK TO THE WEST AND EVENTUALLY SOUTHWEST. THE HIGH PRESSURE RIDGE WILL CONTINUE EAST ON FRIDAY NIGHT...AS THE CENTER OF THE HIGH MOVES INTO THE MID ATLANTIC STATES. WITH THE MORE ZONAL FLOW ALOFT...EXPECT TEMPERATURES TO BEGIN TO MODERATE HEADING INTO THE WEEKEND BUT STILL BE BELOW NORMAL FOR THIS TIME OF YEAR. MODELS STILL DON/T HAVE MUCH CONSISTENCY FOR THIS WEEKEND...AS THEY AREA STRUGGLING WITH THE TIMING/LOCATION OF THE INITIAL SHORTWAVE EJECTING NORTHEAST OUT OF THE UPPER TROUGH OVER THE ROCKIES. THUS...WILL FOLLOW A GENERAL MODEL CONSENSUS AND BRING SLIGHT CHANCE POPS INTO THE AREA FOR SATURDAY NIGHT AND CHANCE ON SUNDAY. WITH THE WARM AIR WRAPPING NORTHWARD...DID GO WITH MAINLY RAIN ON SUNDAY OVER THE EASTERN U.P. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1216 PM EST MON NOV 17 2014 DEEP MID/UPPER LEVEL TROF AND ASSOCIATED DEEP MOISTURE PUSHING ACROSS THE AREA WILL LEAD TO HEAVIER LAKE EFFECT SNOW SHOWERS AFFECTING KIWD/KCMX UNDER NW FLOW. COMBINATION OF SNOW AND GUSTY NW WINDS CREATING BLSN WILL LIKELY RESULT IN LIFR CONDITIONS PREVAILING AT BOTH TERMINALS. AS DEEPER MOISTURE BEGINS TO EXIT...EXPECT IMPROVEMENT TO IFR LATE TONIGHT/EARLY TUE MORNING AND THEN TO MVFR BY TUE AFTN. AT KSAW...NW WIND DIRECTION WILL NOT BE FAVORABLE FOR ANYTHING MORE THAN -SHSN AT TIMES. MVFR CIGS WILL DEVELOP THIS AFTN AND CONTINUE THRU THE REMAINDER OF THE FCST PERIOD. THERE MAY BE A FEW PERIODS OF MVFR VIS IN -SHSN LATER THIS AFTN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 646 AM EST MON NOV 17 2014 LOW PRESSURE OVER FAR NORTHERN LAKE SUPERIOR WILL SHIFT EAST TODAY...SWEEPING A SURFACE TROUGH SOUTHEAST ACROSS LAKE SUPERIOR TODAY. BEHIND THE TROUGH...LOOK FOR GUSTS TO INCREASE TO GALES OF 35-40KTS OVER PORTIONS OF W LAKE SUPERIOR THIS AFTERNOON...BEFORE EXPANDING TO THE E HALF OF LAKE SUPERIOR THIS EVENING THROUGH EARLY TUESDAY. THE TIMING OF THE GALE WARNING WAS IN GOOD SHAPE AND WILL CONTINUE. A TROUGH WILL THEN LINGER ACROSS LAKE SUPERIOR THROUGH TUESDAY MORNING...BEFORE BRIEFLY BEING REPLACED BY A RIDGE TUESDAY AFTERNOON AND EVENING. ANOTHER TROUGH OVER N MANITOBA ON TUESDAY WILL SLIDE ACROSS THE UPPER GREAT LAKES LATE TUESDAY NIGHT THROUGH WEDNESDAY...BEFORE EXITING ACROSS THE ONTARIO AND QUEBEC BORDER THURSDAY MORNING. A FEW NORTHWEST GALE FORCE GUSTS TO 35 KNOTS ARE POSSIBLE OVER EASTERN LAKE SUPERIOR LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. HIGH PRESSURE OVER THE N PLAINS ON THURSDAY WILL DIVE ACROSS THE OHIO VALLEY LATE FRIDAY...EXTENDING A RIDGE OVER THE UPPER GREAT LAKES ON FRIDAY AND DIMINISHING WINDS BELOW 25 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ004-084. LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR MIZ006-085. LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ TUESDAY FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR MIZ007. LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST TUESDAY FOR MIZ005. LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST TUESDAY FOR MIZ014. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 1 PM EST TUESDAY FOR LSZ251-267. GALE WARNING FROM 4 PM THIS AFTERNOON TO 1 PM EST TUESDAY FOR LSZ248>250-265-266. GALE WARNING UNTIL 9 AM EST TUESDAY FOR LSZ264. GALE WARNING UNTIL 4 AM EST /3 AM CST/ TUESDAY FOR LSZ240>242- 263. GALE WARNING UNTIL 7 AM EST TUESDAY FOR LSZ243>245. GALE WARNING UNTIL 1 AM EST /MIDNIGHT CST/ TUESDAY FOR LSZ162. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...ROLFSON MARINE...SRF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1022 AM EST MON NOV 17 2014 .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 LOW PRESSURE PASSING TO OUR NORTH TODAY...WILL USHER IN ANOTHER SURGE OF COLD AIR. LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN SOME PLACES TODAY...BUT HEAVY SNOW IS EXPECTED TONIGHT AND TUESDAY IN SOME OF THE CLASSIC SNOWBELTS. ANOTHER SYSTEM WILL BRING LIGHT SNOW TO THE REGION WEDNESDAY...AND MORE LAKE EFFECT SNOW WILL FOLLOW BEHIND IT. HOWEVER...TEMPERATURES WILL BECOME MILDER DURING THE UPCOMING WEEKEND. && .UPDATE... ISSUED AT 1013 AM EST MON NOV 17 2014 THE FRONT IS MAKING ITS WAY FROM N LAKE MICHIGAN TO NW LOWER. THIS HAS LEAD TO THE SW SNOW BANDS MERGING AND FLARING UP AS THEY MOVE INLAND. THIS WILL LEAD TO TO BRIEFLY HEAVY SNOW AS THE BANDS TRANSIT THE REGION OVER THE NEXT COUPLE OF HOURS. WILL EXPECT THAT THE BANDS WILL LOSE THEIR INTENSITY AS THEY MOVE EAST AWAY FROM THE LAKE. BEHIND THE FRONT, THE SNOW BANDS ARE ALREADY REFORMING WITH THE WEST WIND OVER THE N LAKE MICHIGAN. WILL BE EXPECTING THAT THE SNOW BANDS WILL REESTABLISH QUICKLY, BUT THE WHETHER THEY WILL REMAIN STATIONARY OR BE TRANSIENT OVER THE AFTERNOON IS UNCERTAIN AS THE MODELS HAVE VARYING SOLUTIONS WITH A SPREAD OF ABOUT 30 DEGREES IN THE 1000-850 MB WIND DIRECTIONS. WILL CONTINUE THE GOING AFTERNOON FORECAST UNTIL THE BANDS SHOW THEIR INTENTIONS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 331 AM EST MON NOV 17 2014 ...SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED LATER TODAY THROUGH TUESDAY... HIGH IMPACT WEATHER POTENTIAL: LOCALIZED VERY HEAVY LAKE EFFECT SNOW. AREAS OF BLOWING SNOW AND NEAR WHITEOUT CONDITIONS POSSIBLE TONIGHT. PATTERN SYNOPSIS/CURRENT CONDITIONS: KINDA STATING THE OBVIOUS...BUT MID-WINTER LIKE PATTERN WELL ESTABLISHED ACROSS THE NORTHERN LAKES. REASON FOR SUCH IS ONE ANOMALOUSLY DEEP MERIDIONAL FLOW REGIME...CONSISTING OF FULL LENGTH WESTERN NOAM RIDGING AND JUST AS IMPRESSIVE TROUGHING EXTENDING THROUGH THE CENTRAL PLAINS INTO THE WESTERN LAKES. MOST IMPRESSIVE COLD SURGE YET TIED TO WAVE OF ARCTIC ORIGIN DIVING INTO SOUTHWEST ONTARIO AND INTO MINNESOTA (-20C H8 TEMPERATURES PER LATEST RAP ANALYSIS!). SURFACE COLD FRONT RUNNING WELL AHEAD OF THIS WAVE...ALREADY PUSHING INTO NORTHWEST MICHIGAN AT THIS EARLY HOUR. AREA OUT AHEAD OF THIS FRONT PLENTY COLD ENOUGH TO CONTINUE TO ENTICE A SIGNIFICANT LAKE RESPONSE (A PRETTY RARE FEAT TO HAVE SUCH COLD PRE-FRONTAL AIR DURING MID NOVEMBER). MAIN SHOW TONIGHT HAS BEEN DIRECTED INTO PARTS OF EASTERN UPPER MICHIGAN.. WHERE NO DOUBT SEVERAL INCHES OF ACCUMULATION HAVE ALREADY OCCURRED. SOMEWHAT LIGHTER MORE NUISANCE TYPE SNOWS IMPACTING NORTHER LOWER...ALTHOUGH SOME EMBEDDED HEAVIER LAKE ENHANCED SNOWS WERE NOTED...ESPECIALLY ACROSS PARTS OF EMMET COUNTY. SIMPLY NO END IN SIGHT...WITH CURRENT UPSTREAM WAVE SET TO AMPLIFY OVERHEAD LATER TODAY AND TONIGHT...FORCING A SHIFTING OF THE WINDS TO MORE W/NW AND PUTTING THE MORE TRADITIONAL LAKE EFFECT AREAS UNDER THE GUN FOR A HIGH IMPACT WINTER WEATHER EVENT. PRIMARY FORECAST CONCERNS/CHALLENGES: MULTIPLE! INITIAL FOCUS ON ONGOING SW FLOW LAKE EFFECT AND ASSOCIATED HEADLINES THIS MORNING. OVERNIGHT FOCUS ON MUCH MORE WIDESPREAD LAKE SNOW EVENT...INCLUDING AMOUNTS AND HEADLINE MANAGEMENT CONCERNS. DETAILS: NOT PRETTY! FIRST OFF...ONGOING SW FLOW LAKE SNOWS SHOULD STEADILY DECLINE IN INTENSITY SHORTLY AFTER 09Z AS WINDS BEGIN TO SLOWLY VEER AND BRIEF CORRIDOR OF UPSTREAM DRIER AIR OVERSPEADS THE LAKES. CURRENT HEADLINES RUN THROUGH 15Z...WHICH OFFERS SOME FLEXIBILITY IF BANDS SHOULD PERSIST LONGER THAN ANTICIPATED (NEVER SEEN THAN BEFORE :)). NO OFFICIAL REPORTS JUST YET...BUT BASED OFF MACKINAC BRIDGE WEB CAMS AND SOME INFORMATION GLEANED FROM CALLING ST. IGNACE...GOTTA FEELING WE WILL BE DEALING WITH SOME IMPRESSIVE SNOWFALL TOTALS UP IN THE STRAITS AREA BEFORE ALL IS SAID AND DONE THIS MORNING. ELSEWHERE...JUST SOME LIGHTER SNOWS EXPECTED AS THE COLD FRONT PUSHES EAST...EXITING STAGE RIGHT BY MID-MORNING. WITH PART ONE DONE...ALL FOCUS SHIFTS TO WHAT INCREASINGLY LOOKS LIKE A VERY SIGNIFICANT AND PROLONGED LAKE EFFECT EVENT FOR THE MORE TRADITIONAL SNOW BELTS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN. CURRENT SOUTHWEST ONTARIO WAVE CONTINUES TO DIG...SLOWLY CROSSING THE NORTHERN LAKES THROUGH THE OVERNIGHT. DESPITE MAIN CORE OF ATTENDANT CAA ACTUALLY PASSING US BY TO THE SOUTH...INSTABILITY RAMPS UP IMPRESSIVELY LATE TODAY THROUGH THE OVERNIGHT...WITH NEAR EXTREME DELTA T/S COLLOCATED WITH DEEP SYNOPTIC MOISTURE SUPPORT AND ESSENTIALLY ALL LOSS OF AN INVERSION. CYCLONIC FLOW IS IMPRESSIVE... SUGGESTING ENHANCED CONVERGENCE TARGETING NORTHWEST LOWER MICHIGAN. LOW LEVEL FLOW IS SLIGHTLY MORE BACKED IN RECENT GUIDANCE RUNS...WELL SUPPORTED BY WHAT SHOULD BE STRENGTHENING LAKE DRIVEN SURFACE TROUGH DEVELOPMENT. AFTER A BRIEF BREAK THIS AFTERNOON... EXPECT SNOWS TO GET GOING IN EARNEST THIS EVENING...WITH INITIAL FOCUS IN FAVORED WEST FLOW AREAS...WITH A SLIGHT SOUTHWARD TREND EXPECTED DURING THE OVERNIGHT TOWARD THE M-32 CORRIDOR. SNOWFALL AMOUNTS COULD BE QUITE IMPRESSIVE...WITH STRONG OMEGA CENTERED RIGHT IN PRIME DGZ RIGHT THROUGH THE OVERNIGHT. DESPITE SOME FRAGMENTATION OF FLAKES FROM VERY GUSTY WINDS (MORE ON THE WINDS TO FOLLOW)...EXPECT SNOW TO LIQUID RATIOS TO PUSH 20 TO 1...PERHAPS EVEN HIGHER IF STRONG LOW LEVEL CONVERGENCE UNDER BANDS HELP SLACKING THE WIND FIELDS. SLIGHT SOUTHWARD DRIFT LOOKS TO BE THE ONLY THING FROM PREVENTING SNOW AMOUNTS FROM GETTING TOO OUT OF HAND. STILL...COULD EASILY SEE PARTS OF CHARLEVOIX/ANTRIM/OTSEGO/EMMET/CHEBOYGAN COUNTIES EXCEEDING 8 INCHES BY MORNING...WITH THE HIGHEST AMOUNTS JUST DOWNWIND OF LITTLE TRAVERSE BAY. ANY SLOWER DRIFT OF BANDS THAN CURRENTLY ANTICIPATED WILL RESULT IN LOCALLY HIGHER AMOUNTS. FURTHER SOUTH...COMPLETE LACK OF A LAKE SUPERIOR CONNECTION REALLY SHORTENS THE EFFECTIVE FETCH LENGTH. SO...DESPITE EXCELLENT INSTABILITY...JUST NOT SEEING THE OPPORTUNITY FOR A WHOLE LOT OF ACCUMULATION ALONG AND SOUTH OF THE M- 72 CORRIDOR. HOWEVER...GUSTY WINDS OF 20 TO 30 MPH WILL MAKE FOR SOME NASTY CONDITIONS...CREATING AREAS OF BLOWING AND DRIFTING SNOW AND BRIEF PERIODS OF VERY LOW VISIBILITIES. OFF LAKE SUPERIOR: INITIAL FOCUS THIS EVENING LOOKS TO REMAIN WEST OF WHITEFISH POINT...REALLY TARGETING AREAS OVER NEAR MUNISING AND SENEY. WINDS BEGIN TO SHIFT MORE W/NW LATE...BRINGING ACCUMULATING SNOW BANDS INTO NORTHWEST CHIPPEWA COUNTY. LATER START AND SIGNALS FOR BEST LOW LEVEL CONVERGENCE TO REMAIN OFF TO THE WEST SUGGESTS LOWER SNOW TOTALS THAN THOSE TO THE SOUTH...WITH 2 TO 4 INCHES EXPECTED BY MORNING. STRONG WINDS WILL PUSH BANDS FURTHER INLAND THAN WHAT IS NORMAL...PERHAPS EVEN BRINGING PARTS OF NORTHWEST MACKINAC COUNTY SEVERAL INCHES BY MORNING. MORE SNOW WILL FALL IN ALL THE ABOVE AREAS TOMORROW...WITH SEVERAL MORE INCHES EXPECTED (SEE LONG TERM SECTION BELOW). HEADLINES: FOR NORTHERN LOWER...GIVEN GUSTY WINDS AND WHAT COULD BE WIDESPREAD BLOWING SNOW EVEN OUTSIDE THE BETTER SNOW BANDS...HAVE DECIDED TO FORGO THE SPECIFIC LAKE EFFECT HEADLINES FOR MORE GENERIC WINTER WEATHER HEADLINES. HIGHEST SNOW TOTAL AREA MENTIONED EARLIER WILL BE UPGRADED TO A WINTER STORM WARNING...STARTING AT 00Z THIS EVENING RUNNING RIGHT THROUGH TUESDAY. WINTER WEATHER ADVISORIES SHOULD DO FOR AREAS SOUTH OF M-72...AS WELL AS PARTS OF NORTHEAST LOWER AS STRONG WINDS HELP PUSH WEAKENING BANDS FAR INLAND. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 331 AM EST MON NOV 17 2014 HIGH IMPACT WEATHER POTENTIAL...PLENTY OF SNOW AND COLD DURING THE WORK WEEK. HEAVY LAKE EFFECT SNOW IN WNW/NW FLOW TUESDAY. SOME POTENTIAL FOR HEAVY LAKE EFFECT SNOW WED NIGHT TO THU NIGHT. TUESDAY...UPPER LOW WILL EJECT FROM NORTH OF LAKE HURON INTO EASTERN QUEBEC. ONE TRAILING SHORTWAVE WILL CROSS CENTRAL LOWER MI IN THE AFTERNOON...ANOTHER WEAK WAVE WILL DIG TOWARD EASTERN SUPERIOR. A 980MB SURFACE LOW STARTS THE MORNING IN CENTRAL QUEBEC...AND WILL ADVANCE NE. SUBSTANTIAL TROFFING LINGERS ACROSS THE AREA EARLY IN THE MORNING...THIS RELAXES AS THE UPPER LOW PULLS OUT...BUT LAKE- INDUCED TROFFING REMAINS EVIDENT THRU THE DAY. 1000-850MB WINDS REMAIN STEADY-STATE IN THE MORNING...WNW INTO NORTHERN LOWER AND NW INTO EASTERN UPPER. WINDS WILL BACK SOME DURING THE AFTERNOON...BY EARLY EVENING WE WILL SEE A W FETCH INTO NORTHERN LOWER AND WNW INTO EASTERN UPPER. PLENTY OF DEEP MOISTURE...HIGH INVERSION HEIGHTS (TO NEARLY 500MB)...AND DELTA T/S NEAR 20C SHOULD ENSURE RAMPAGING LAKE EFFECT SNOW IN THE MORNING HOURS. IN THE AFTERNOON...THE INVERSION LOWERS TOWARD 700MB WITH DRYING ALOFT. THAT WILL REDUCE SNOW INTENSITY SOMEWHAT...BUT BY AND LARGE PARAMETERS AND STILL VERY FAVORABLE. AS IS THE CASE FOR TONIGHT...THE LOW-LEVEL FLOW IS A LITTLE BACKED COMPARED TO PREVIOUS RUNS. IN NORTHERN LOWER...THIS REQUIRES ADJUSTING THE MAX SNOW TOTALS NORTHWARD SLIGHTLY. CHARLEVOIX/ANTRIM/OTSEGO ARE THE MAIN ONES UNDER THE GUN...BUT THE FETCH NOW SUPPORTS MORE SNOW IN SOUTHERN EMMET/CHEBOYGAN THAN IT DOES IN NORTHERN KALKASKA/CRAWFORD. 5-9 INCHES STILL LIKES A GOOD FORECAST FOR THE DAY IN THE HARDEST-HIT LOCALES...CENTERED ON ELMIRA. 1-4 INCHES WORKS ELSEWHERE IN NW LOWER...WHERE THE FETCH IS MUCH SHORTER AND HAS NO CONNECTION TO SUPERIOR. IN EASTERN UPPER...THE BACKED FLOW OPENS UP MORE OF CHIPPEWA...BUT SHOULD STILL KEEP THE STRONGEST BANDS WEST OF THE SAULT. BUT THINGS ARE LOOKING CONSIDERABLY MORE FAVORABLE UP THERE...AND WILL INCREASE WESTERN CHIP AND FAR NW MACK INTO THE 3-5 INCH RANGE. MAX TEMPS WILL BE MAINLY IN THE 20S. HOWEVER...IN THE HIGH TERRAIN IN THE SOUTH...WHERE MARINE MODIFICATION WILL BE SMALLER DUE TO THE SHORTER FETCH...SOME PLACES (LIKE CAD) WILL LIKELY NOT ESCAPE THE TEENS. (HARD TO BELIEVE IT/S ONLY MID-NOVEMBER.) TUE NIGHT/WED...NOT MUCH REST FOR THE SNOW-WEARY. CLIPPER SHORTWAVE WILL ADVANCE INTO THE WESTERN LAKES ON WED. ASSOCIATED SURFACE LOW WILL ADVANCE FROM THE UPPER MS VALLEY TO NORTHERN LOWER MI ON WED. LOW LEVEL FLOW WILL BACK TO THE SW TUE NIGHT...WITH MOISTENING OVERNIGHT. SOME POTENTIAL FOR SOME SNEAKY 1-3 INCH ACCUMS OVER THE TIP OF NORTHERN LOWER TUE EVENING. SYNOPTIC -SN MIGHT SNEAK INTO SW SECTIONS LATE TUE NIGHT...BUT THE BULK OF THE THAT WILL WAIT UNTIL WED. BY THEN...A SOUTH 1000-850MB FETCH SHOULD KEEP MOST OF THE LAKE- INDUCED NONSENSE AT BAY...OTHER THAN ALONG THE SOUTH SHORE OF UPPER MI (AND IT IS UNCERTAIN WHETHER SYNOPTIC PRECIP WILL MAKE IT THAT FAR NORTH). THIS SYSTEM DOES NOT LOOK LIKE A MAJOR PROBLEM...1-2 INCHES...ESPECIALLY SOUTH OF M-32. MIN TEMPS TEENS TO PERHAPS HIGH SINGLE DIGITS (YIKES). MAX TEMPS 20S. REST OF THE FORECAST...POST-CLIPPER LAKE EFFECT SNOW WILL OCCUR WED NIGHT INTO THU NIGHT...AIDED BY ANOTHER CLIPPER SHORTWAVE DROPPING IN FROM THE NW. THE SET-UP FOR HEAVY SNOW LOOKS BETTER IN EASTERN UPPER IN THIS EVENT...AS DEEPER MOISTURE WILL LINGER LONGER THERE VS MID-LEVEL DRY AIR TRYING TO ENTRAIN INTO THE SOUTHER/CENTRAL LAKES. REGARDLESS...LAKE EFFECT SHSN WILL AGAIN BE FAIRLY WIDESPREAD IN BOTH PENINSULAS. THOUGH THE MODELS TEND TO BE TOO FAST TO BREAK PATTERNS DOWN...ALL MODELS HAVE THE CURRENT ONE FALL APART AFTER THIS LAST CLIPPER. 500MB FLOW BECOMES CONSIDERABLY MORE ZONAL...AND MORE SEASONABLE AIR WILL FINALLY GET A CHANCE TO MOVE INTO THE REGION...ESPECIALLY BY THE TAIL END OF THE WEEKEND. A SOUTHERN STREAM SYSTEM MOVING INTO THE CENTRAL STATES WILL AMPLIFY WARM ADVECTION...AND INCREASE PRECIP CHANCES BY SUNDAY. THIS ACTUALLY LOOKS TO BE MOSTLY RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 632 AM EST MON NOV 17 2014 VFR TO MVFR AT APN...MVFR TO IFR ELSEWHERE IN LAKE EFFECT CLOUDS/SHSN. LOW PRESSURE ALONG THE NORTH SHORE OF SUPERIOR WILL MOVE EAST TODAY...BRINGING ANOTHER SHOT OF COLD AIR TO THE REGION. LAKE EFFECT SHSN TODAY WILL BECOME LESS ORGANIZED DUE TO VARYING WINDS AND DRYING ALOFT. HOWEVER...SHSN WILL RAMP UP TONIGHT IN THE SNOWBELTS OF FAR NORTHERN LOWER MICHIGAN...BETWEEN PLN AND GOV. WILL HAVE VARYING CONDITIONS TODAY...TENDING TO MVFR NEAR LAKE MI AND VFR AT APN. TONIGHT..LAKE MI TAF SITES WILL BE MAINLY IFR (LIFR LATE AT PLN)...WHILE APN BECOMES MVFR. WINDS WILL VEER W TODAY...STAY W AND INCREASE/BECOME GUSTY TONIGHT. && .MARINE... ISSUED AT 331 AM EST MON NOV 17 2014 STRONG SURGE OF CAA AND INCREASINGLY SHARP PRESSURE GRADIENT WILL BRING VERY GUSTY WINDS BY LATER TODAY RIGHT THROUGH TUESDAY. GREATEST IMPACT EXPECTED ACROSS NORTHERN LAKE MICHIGAN...WHERE GALE FORCE WEST WINDS ARE EXPECTED TO DEVELOP QUICKLY THIS EVENING. SCA CONDITIONS EXPECTED ELSEWHERE...ALTHOUGH WILL NEED TO BE ON THE LOOKOUT FOR SOME GALE GUSTS ALONG THE NORTHEAST LOWER COASTLINE. WINDS ARE EXPECTED TO SUBSIDE LATE TUESDAY...AND ESPECIALLY TUESDAY NIGHT. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY FOR MIZ018-020-023-025>028-031>033. WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY FOR MIZ016-017-019-021-022. WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR MIZ008. LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LMZ341. GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LMZ323-342-344>346. LS...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EST TUESDAY FOR LSZ321-322. && $$ UPDATE...JSL SYNOPSIS...JAZ SHORT TERM...MSB LONG TERM...JAZ AVIATION...JAZ MARINE...MSB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
647 AM EST MON NOV 17 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EST MON NOV 17 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS INDICATE A DEEPENING UPR TROF OVER CENTRAL NAMERICA WITH CLOSED H5 LO OVER ONTARIO JUST NW OF LK SUP CAUSING 12HR H5 HGT FALLS UP TO 130M BTWN 16/12Z AND 17/00Z AT INL AND DRAWING H5 TEMPS CLOSE TO -40C S UNDER THE AXIS OF LOWEST HGTS. BAND OF DPVA/DEEP LYR QVECTOR CNVGC/AXIS OF MID LVL MSTR IN ADVANCE OF SHRTWV ROTATING ARND THE CLOSED LO IS CROSSING UPR MI EARLY THIS MRNG...BUT DRYNESS OF AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.16 INCH IS 45 PCT OF NORMAL/ IS GREATLY LIMITING THE COVERAGE/INTENSITY OF ACCOMPANYING LIGHT SN. THERE HAS BEEN SOME LIGHT SN OVER THE FAR E NEAR NEWBERRY WITH A SW WIND OFF NRN LK MI...BUT THE FLOW HAS NOT BACKED SUFFICIENTLY TO CAUSE THE HEAVIER SN SHOWERS IN MACKINAC COUNTY TO IMPACT LUCE/SCHOOLCRAFT COUNTIES. LOOKING TO THE W...THE 00Z H85/7 TEMPS WERE -17C/-27C AT INL /VS -14C AND -16C AT GRB/. THE 00Z INL IS QUITE MOIST ALMOST UP TO H5 WITHIN A DEEP CYC FLOW. THERE IS A SHARP SFC WSHFT FM W TO NW ALONG A SFC LO PRES TROF RUNNING THRU NRN MN INTO ADJACENT ONTARIO...WITH SFC REPORTS SHOWING SOME MODERATE SN ALONG AND JUST BEHIND THIS BNDRY. MAIN FOCUS IN THE SHORT TERM WL BE ON LES AMOUNTS/GOING HEADLINES ASSOCIATED WITH INCOMING COLD/MOIST AIRMASS. MADE NO CHANGES ATTM TO HEADLINES ISSUED BY THE PREVIOUS SHIFT. TODAY...AS CUTOFF H5 LO DEEPENS FURTHER AND SLIDES SLOWLY TO THE E ACROSS UPR MI...SHARP CYC LLVL FLOW IS FCST TO SLOWLY ENVELOP THE CWA W-E WITH A WSHFT FM WSW EARLY THIS MRNG TO NW BY LATE IN THE DAY EXCEPT OVER THE SE CWA. THE SHARPER LLVL CNVGC WL ARRIVE OVER THE W ARND 12Z AND RESULT IN INCRSG SN RATES DESPITE SOME DEEP LYR QVECTOR DVGC IN THE WAKE OF THE SHRTWV ROTATING THRU THE UPR LKS EARLY THIS MRNG. THE HIER RES MODELS HAVE CONSISTENTLY POINTED TO THE AREA ARND ONTONAGON COUNTY AS THE FOCUS FOR THE SHARPEST CNVGC. GOING START TIME OF 12Z FOR THE WARNINGS OVER THE W APPEARS TO BE ON TRACK. SINCE THE RATHER LO UVV MAX IN THE ABSENCE OF DEEP LYR FORCING WL BE CENTERED IN THE DGZ...EXPECT GOOD SN/WATER RATIOS IN EXCESS OF 20:1 DESPITE A DGZ DEPTH OF ONLY ABOUT 3K FT AND INCRSG WINDS THAT WOULD TEND TO FRAGMENT THE SN FLAKES. WITH SOME INCRSG DEEP LYR QVECTOR CNVGC/UVV OVER THE W HALF LATER IN THE DAY UNDER THE DEEPENING UPR TROF AXIS...FCST SDNGS ALSO INDICATE INCRSG DEEP MSTR THRU THE DAY PER THE 00Z INL RAOB WITH EQUILIBRIUM LVLS APRCHG 10K FT OVER THE BY LATER IN THE DAY AS H85/7 TEMPS DIP TO -16C TO -17C/-27C. INCRSG NW WINDS/DESTABILIZATION WL RESULT IN GUSTY SFC WINDS AND SOME BLSN AS WELL. FARTHER TO THE E...THE LLVL FLOW IS FCST TO BE OUT OF THE W MOST OF THE DAY...SO THE SN SHOWERS THERE SHOULD BE MAINLY CONFINED TO THE LK SHORE UNTIL AT LEAST 21Z...WHEN THE FASTER HI RES CNDN MODEL SHOWS THE ARRIVAL OF SHARPER CYC FLOW/ WSHFT TO THE NW. FCST LES WARNINGS FOR ALGER/NRN SCHOOLCRAFT COUNTIES BEGINS AT 21Z...SO WL NOT CHANGE THIS START TIME. THERE SHOULD BE NOTHING MORE THAN FLURRIES/LIGHT SN SHOWERS OVER THE SCENTRAL WITH DOWNSLOPE FLOW. TNGT...UPR TROF/AXIS OF DEEP LYR QVECTOR CNVGC AND MSTR/SFC LO PRES TROF AND CYC WSHFT TO THE NW ARE PROGGED TO DRIFT SLOWLY E. THESE TRENDS WL RESULT IN INCRSG POPS/SN RATES IN THE NW SN BELTS MAINLY E OF MARQUETTE. THE 00Z NAM AND ESPECIALLY THE HI RES CNDN MODEL HINT LK NIPIGON MOISTENING WL GREATLY ENHANCE SN RATES OVER ALGER/NRN SCHOOLCRAFT COUNTIES...SO THE GOING WRNGS APPEAR ON TRACK. AS WL BE THE CASE TODAY OVER THE W...HI EQUILIBRIUM LVL AND FAVORABLE UVV MAX WITHIN THE DGZ WL BE ENHANCING FACTORS FOR SN RATES IN THIS AREA. ALTHOUGH THE DEPARTURE OF THE DYANAMIC SUPPORT/VERY DEEP MSTR MAY SLOW DOWN THE HEAVY SN RATES OVER THE W BY THE OVERNGT HRS... LINGERING CYC NW BACKING TOWARD THE WNW OVER THE FAR W TOWARD 12Z WL CONTINUE WIDESPREAD SN SHOWERS/CATEGORICAL POPS IN THE FAVORED SN BELTS THERE. ALTHOUGH THE EXPECTED NW FLOW IS NOT FAVORABLE FOR MARQUETTE COUNTY...WL CONTINUE THE ADVY FOR THIS AREA GIVEN POTENTIAL FOR HIER WINDS NEAR THE LK SHORE AND HEAVIER SN IN THE EASTERN PART OF THE COUNTY. ONCE AGAIN...THE LIGHTEST AND LEAST WIDESPREAD SN SHOWERS WL BE OVER THE SCENTRAL. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 646 AM EST MON NOV 17 2014 UPPER TROUGH THAT IS IN THE PROCESS OF MOVING OVER THE AREA TODAY WILL BE STARTING TO MOVE OUT OF THE AREA WHILE A WEAK SURFACE RIDGE OVER THE NORTHERN PLAINS SHIFTS EAST INTO THE UPPER GREAT LAKES REGION. MODERATE TO HEAVY SNOW WILL BE ONGOING OVER PORTIONS OF THE CWA...ESPECIALLY OVER THE EAST (ALGER AND NORTHERN SCHOOLCRAFT COUNTIES) WHERE THE NORTHWEST FLOW LAKE EFFECT WILL BE AIDED BY LOW LEVEL WINDS STARTING TO BACK IN RESPONSE TO THE SURFACE RIDGE AND INCREASING CONVERGENCE. EXPECT THE FAVORABLE CONDITIONS TO CONTINUE THROUGH THE MORNING OVER THE EAST...BEFORE THE DRYING AND LOWERING INVERSION HEIGHTS SEEN OVER THE WEST DURING THE MORNING...MOVES INTO THE AREA AND DIMINISHES THE INTENSITY OF THE LAKE EFFECT. WINDS WILL ALSO BE STEADILY BACKING THROUGH THE DAY...TO THE SOUTHWEST OVER THE WESTERN CWA AND WESTERLY OVER THE EASTERN CWA BY THE EVENING HOURS TUESDAY. THUS...WOULD EXPECT TRANSIENT BANDS BECOMING FOCUSED OVER THE KEWEENAW PENINSULA AND NEAR LAKE SUPERIOR EAST OF PICTURED ROCKS. AS FOR SNOWFALL ACCUMULATION...HAVE ANOTHER 3-5 INCHES NORTHWEST OF A LINE FROM DEERTON TO MANISTIQUE AND ANOTHER 1-3 INCHES OVER THE TRADITIONAL AREAS OVER THE WEST. TUESDAY EVENING...COULD SEE ANOTHER 1-2 INCHES AS THE LAKE EFFECT TRANSITIONS NORTH ACROSS THE KEWEENAW PENINSULA BEFORE IT MOVES OFFSHORE. ALSO ON TUESDAY NIGHT...A SHORTWAVE WILL DIVE SOUTHEAST FROM CENTRAL CANADA...THROUGH NORTHERN MINNESOTA AND INTO WISCONSIN. AT THE SURFACE...A BROAD TROUGH WILL QUICKLY DROP INTO THE AREA AND BRING MORE VARIABLE LOW LEVEL WINDS TO THE AREA. WILL CONTINUE TO SHOW SLIGHT AND LOW CHANCE POPS FOR AREAS NEAR THE WISCONSIN BORDER LATE TUESDAY NIGHT. THIS COULD CONTINUE INTO WEDNESDAY FOR MUCH OF THE AREA AS BROAD MID LEVEL Q-VECTOR CONVERGENCE CONTINUES ALTHOUGH MUCH OF THE AREA WILL BE BETWEEN THE INITIAL SHORTWAVE MOVING INTO LOWER MICHIGAN AND THE SECONDARY SHORTWAVE DROPPING INTO NORTHWEST WISCONSIN LATE WEDNESDAY AFTERNOON. THUS...WILL SHOW SOME POTENTIAL FOR LIGHT SNOW SHOWERS ON WEDNESDAY. ALSO ON WEDNESDAY...COULD SEE LAKE EFFECT OFF LAKE MICHIGAN OVER SOUTHEAST LUCE COUNTY ON WEDNESDAY AFTERNOON AS LOW LEVEL WINDS BACK FAR ENOUGH TO THE SOUTH-SOUTHWEST TO PUSH THE BAND INTO THAT AREA. THEN AS WINDS SHIFT TO THE WEST-NORTHWEST BEHIND A SECONDARY SURFACE TROUGH...EXPECT THE LAKE EFFECT SNOW TO PICKUP IN THE KEWEENAW FIRST (WEDNESDAY AFTERNOON) AND THEN SPREAD OVER THE REST OF THE NORMAL WEST-NORTHWEST FAVORED LOCATIONS OVER THE WEST DURING THE EVENING AND EAST OVERNIGHT. WINDS ON THURSDAY WILL DEPEND ON THE TRAILING SURFACE TROUGH ATTEMPTING TO HOLD OVER EASTERN LAKE SUPERIOR. MODELS VARY ON ITS LOCATION LATE WEDNESDAY NIGHT INTO THURSDAY AND HOW QUICKLY IT DEPARTS. DUE TO THESE DIFFERENCES...THE FINER DETAILS ARE HARD TO PIN DOWN AND WILL FOCUS ON GENERAL NORTHWEST WIND LAKE EFFECT FOR THE TIME BEING. STILL EXPECT VERY FAVORABLE LAKE EFFECT CONDITIONS (DELTA-T VALUES AROUND 23) BUT LAKE INDUCED EQUILIBRIUM VALUES WILL BE 5KFT LOWER THAN TONIGHT (UP TO 13KFT) AND LAKE INDUCED CAPE VALUES WILL PEAK AROUND 800 J/KG. WINDS DO LOOK TO BE WEAKER DURING THIS PERIOD...WHICH WOULD LEAD TO LESS FRACTURING OF THE DENDRITES...BUT DO HAVE A LITTLE CONCERN THAT THE TOP HALF OF THE CLOUD WILL BE ABOVE THE DGZ AND SUPPORT MORE COLUMNS IN THE SNOW AND LEAD TO LOWER RATIOS. THUS...WILL STICK WITH SNOW RATIOS AROUND OR JUST ABOVE 20-1 AT THIS POINT AND WILL BE ABLE TO FINE TUNE WITH FUTURE SHIFTS. THIS PRODUCES SNOWFALL AMOUNTS OF 5 TO 11 INCHES IN THE NORTHWEST TO WEST-NORTHWEST WIND SNOW BELTS FOR WEDNESDAY AFTERNOON INTO THURSDAY EVENING. CURRENT THINKING IS A GENERAL LES ADVISORY WILL BE NEEDED AT SOME POINT (UNLESS INCREASED CONVERGENCE OCCURS ALONG THE TRAILING SURFACE TROUGH) AND WILL CONTINUE TO HIGHLIGHT IN THE HWO/EHWO. UPPER TROUGH WILL BEGIN TO SHIFT EAST AND OUT OF THE AREA ON THURSDAY...ALLOWING AN UPPER RIDGE TO BUILD TOWARDS THE AREA THURSDAY NIGHT AND IN TURN A SURFACE RIDGE. THIS WILL GRADUALLY WEAKEN THE LAKE EFFECT ON THURSDAY NIGHT INTO FRIDAY AS INVERSION HEIGHTS STEADILY FALL AND WINDS BACK TO THE WEST AND EVENTUALLY SOUTHWEST. THE HIGH PRESSURE RIDGE WILL CONTINUE EAST ON FRIDAY NIGHT...AS THE CENTER OF THE HIGH MOVES INTO THE MID ATLANTIC STATES. WITH THE MORE ZONAL FLOW ALOFT...EXPECT TEMPERATURES TO BEGIN TO MODERATE HEADING INTO THE WEEKEND BUT STILL BE BELOW NORMAL FOR THIS TIME OF YEAR. MODELS STILL DON/T HAVE MUCH CONSISTENCY FOR THIS WEEKEND...AS THEY AREA STRUGGLING WITH THE TIMING/LOCATION OF THE INITIAL SHORTWAVE EJECTING NORTHEAST OUT OF THE UPPER TROUGH OVER THE ROCKIES. THUS...WILL FOLLOW A GENERAL MODEL CONSENSUS AND BRING SLIGHT CHANCE POPS INTO THE AREA FOR SATURDAY NIGHT AND CHANCE ON SUNDAY. WITH THE WARM AIR WRAPPING NORTHWARD...DID GO WITH MAINLY RAIN ON SUNDAY OVER THE EASTERN U.P. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 646 AM EST MON NOV 17 2014 THE COMBINATION OF INCRSG DEEP MSTR AND AN APRCHG LO PRES TROF WL BRING HEAVIER LAKE EFFECT SN TO CMX AND IWD...WITH CONDITIONS AT THOSE SITES DETERIORATING TO IFR THIS MRNG. AS CYC NW WINDS BECOME QUITE GUSTY FOLLOWING THE PASSAGE OF THE TROF...EXPECT CONSIDERABLE BLSN TO REDUCE VSBYS INTO THE LIFR RANGE AT IWD AND CMX FOR THE REST OF THE FCST PERIOD. THE STRONGEST WINDS WITH GUSTS NEAR 30KTS WL IMPACT THE MORE EXPOSED CMX LOCATION. SINCE THE FLOW WL BE A DOWNSLOPE W WIND AT SAW THRU THIS MRNG...VFR CONDITIONS WL PREDOMINATE THERE UNTIL THE ARRIVAL OF DEEPER MSTR AND THE TROF LATER THIS AFTN. IFR TO AT TIMES MVFR VSBYS WL THEN BE THE RULE UNTIL LATE TNGT...WHEN THE DEEPER MSTR WL BEGIN TO DIMINISH AND CONDITIONS IMPROVE TO MVFR/PERHAPS VFR WITH DOWNSLOPE WIND COMPONENT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 646 AM EST MON NOV 17 2014 LOW PRESSURE OVER FAR NORTHERN LAKE SUPERIOR WILL SHIFT EAST TODAY...SWEEPING A SURFACE TROUGH SOUTHEAST ACROSS LAKE SUPERIOR TODAY. BEHIND THE TROUGH...LOOK FOR GUSTS TO INCREASE TO GALES OF 35-40KTS OVER PORTIONS OF W LAKE SUPERIOR THIS AFTERNOON...BEFORE EXPANDING TO THE E HALF OF LAKE SUPERIOR THIS EVENING THROUGH EARLY TUESDAY. THE TIMING OF THE GALE WARNING WAS IN GOOD SHAPE AND WILL CONTINUE. A TROUGH WILL THEN LINGER ACROSS LAKE SUPERIOR THROUGH TUESDAY MORNING...BEFORE BRIEFLY BEING REPLACED BY A RIDGE TUESDAY AFTERNOON AND EVENING. ANOTHER TROUGH OVER N MANITOBA ON TUESDAY WILL SLIDE ACROSS THE UPPER GREAT LAKES LATE TUESDAY NIGHT THROUGH WEDNESDAY...BEFORE EXITING ACROSS THE ONTARIO AND QUEBEC BORDER THURSDAY MORNING. A FEW NORTHWEST GALE FORCE GUSTS TO 35 KNOTS ARE POSSIBLE OVER EASTERN LAKE SUPERIOR LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. HIGH PRESSURE OVER THE N PLAINS ON THURSDAY WILL DIVE ACROSS THE OHIO VALLEY LATE FRIDAY...EXTENDING A RIDGE OVER THE UPPER GREAT LAKES ON FRIDAY AND DIMINISHING WINDS BELOW 25 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ004-084. LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR MIZ006-085. LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ TUESDAY FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR MIZ007. LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST TUESDAY FOR MIZ005. LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST TUESDAY FOR MIZ014. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 1 PM EST TUESDAY FOR LSZ251-267. GALE WARNING FROM 4 PM THIS AFTERNOON TO 1 PM EST TUESDAY FOR LSZ248>250-265-266. GALE WARNING FROM 1 PM THIS AFTERNOON TO 9 AM EST TUESDAY FOR LSZ264. GALE WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO 4 AM EST /3 AM CST/ TUESDAY FOR LSZ240>242-263. GALE WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST TUESDAY FOR LSZ243>245. GALE WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO 1 AM EST /MIDNIGHT CST/ TUESDAY FOR LSZ162. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...SRF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
632 AM EST MON NOV 17 2014 .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 LOW PRESSURE PASSING TO OUR NORTH TODAY...WILL USHER IN ANOTHER SURGE OF COLD AIR. LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN SOME PLACES TODAY...BUT HEAVY SNOW IS EXPECTED TONIGHT AND TUESDAY IN SOME OF THE CLASSIC SNOWBELTS. ANOTHER SYSTEM WILL BRING LIGHT SNOW TO THE REGION WEDNESDAY...AND MORE LAKE EFFECT SNOW WILL FOLLOW BEHIND IT. HOWEVER...TEMPERATURES WILL BECOME MILDER DURING THE UPCOMING WEEKEND. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 331 AM EST MON NOV 17 2014 ...SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED LATER TODAY THROUGH TUESDAY... HIGH IMPACT WEATHER POTENTIAL: LOCALIZED VERY HEAVY LAKE EFFECT SNOW. AREAS OF BLOWING SNOW AND NEAR WHITEOUT CONDITIONS POSSIBLE TONIGHT. PATTERN SYNOPSIS/CURRENT CONDITIONS: KINDA STATING THE OBVIOUS...BUT MID-WINTER LIKE PATTERN WELL ESTABLISHED ACROSS THE NORTHERN LAKES. REASON FOR SUCH IS ONE ANOMALOUSLY DEEP MERIDIONAL FLOW REGIME...CONSISTING OF FULL LENGTH WESTERN NOAM RIDGING AND JUST AS IMPRESSIVE TROUGHING EXTENDING THROUGH THE CENTRAL PLAINS INTO THE WESTERN LAKES. MOST IMPRESSIVE COLD SURGE YET TIED TO WAVE OF ARCTIC ORIGIN DIVING INTO SOUTHWEST ONTARIO AND INTO MINNESOTA (-20C H8 TEMPERATURES PER LATEST RAP ANALYSIS!). SURFACE COLD FRONT RUNNING WELL AHEAD OF THIS WAVE...ALREADY PUSHING INTO NORTHWEST MICHIGAN AT THIS EARLY HOUR. AREA OUT AHEAD OF THIS FRONT PLENTY COLD ENOUGH TO CONTINUE TO ENTICE A SIGNIFICANT LAKE RESPONSE (A PRETTY RARE FEAT TO HAVE SUCH COLD PRE-FRONTAL AIR DURING MID NOVEMBER). MAIN SHOW TONIGHT HAS BEEN DIRECTED INTO PARTS OF EASTERN UPPER MICHIGAN.. WHERE NO DOUBT SEVERAL INCHES OF ACCUMULATION HAVE ALREADY OCCURRED. SOMEWHAT LIGHTER MORE NUISANCE TYPE SNOWS IMPACTING NORTHER LOWER...ALTHOUGH SOME EMBEDDED HEAVIER LAKE ENHANCED SNOWS WERE NOTED...ESPECIALLY ACROSS PARTS OF EMMET COUNTY. SIMPLY NO END IN SIGHT...WITH CURRENT UPSTREAM WAVE SET TO AMPLIFY OVERHEAD LATER TODAY AND TONIGHT...FORCING A SHIFTING OF THE WINDS TO MORE W/NW AND PUTTING THE MORE TRADITIONAL LAKE EFFECT AREAS UNDER THE GUN FOR A HIGH IMPACT WINTER WEATHER EVENT. PRIMARY FORECAST CONCERNS/CHALLENGES: MULTIPLE! INITIAL FOCUS ON ONGOING SW FLOW LAKE EFFECT AND ASSOCIATED HEADLINES THIS MORNING. OVERNIGHT FOCUS ON MUCH MORE WIDESPREAD LAKE SNOW EVENT...INCLUDING AMOUNTS AND HEADLINE MANAGEMENT CONCERNS. DETAILS: NOT PRETTY! FIRST OFF...ONGOING SW FLOW LAKE SNOWS SHOULD STEADILY DECLINE IN INTENSITY SHORTLY AFTER 09Z AS WINDS BEGIN TO SLOWLY VEER AND BRIEF CORRIDOR OF UPSTREAM DRIER AIR OVERSPEADS THE LAKES. CURRENT HEADLINES RUN THROUGH 15Z...WHICH OFFERS SOME FLEXIBILITY IF BANDS SHOULD PERSIST LONGER THAN ANTICIPATED (NEVER SEEN THAN BEFORE :)). NO OFFICIAL REPORTS JUST YET...BUT BASED OFF MACKINAC BRIDGE WEB CAMS AND SOME INFORMATION GLEANED FROM CALLING ST. IGNACE...GOTTA FEELING WE WILL BE DEALING WITH SOME IMPRESSIVE SNOWFALL TOTALS UP IN THE STRAITS AREA BEFORE ALL IS SAID AND DONE THIS MORNING. ELSEWHERE...JUST SOME LIGHTER SNOWS EXPECTED AS THE COLD FRONT PUSHES EAST...EXITING STAGE RIGHT BY MID-MORNING. WITH PART ONE DONE...ALL FOCUS SHIFTS TO WHAT INCREASINGLY LOOKS LIKE A VERY SIGNIFICANT AND PROLONGED LAKE EFFECT EVENT FOR THE MORE TRADITIONAL SNOW BELTS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN. CURRENT SOUTHWEST ONTARIO WAVE CONTINUES TO DIG...SLOWLY CROSSING THE NORTHERN LAKES THROUGH THE OVERNIGHT. DESPITE MAIN CORE OF ATTENDANT CAA ACTUALLY PASSING US BY TO THE SOUTH...INSTABILITY RAMPS UP IMPRESSIVELY LATE TODAY THROUGH THE OVERNIGHT...WITH NEAR EXTREME DELTA T/S COLLOCATED WITH DEEP SYNOPTIC MOISTURE SUPPORT AND ESSENTIALLY ALL LOSS OF AN INVERSION. CYCLONIC FLOW IS IMPRESSIVE... SUGGESTING ENHANCED CONVERGENCE TARGETING NORTHWEST LOWER MICHIGAN. LOW LEVEL FLOW IS SLIGHTLY MORE BACKED IN RECENT GUIDANCE RUNS...WELL SUPPORTED BY WHAT SHOULD BE STRENGTHENING LAKE DRIVEN SURFACE TROUGH DEVELOPMENT. AFTER A BRIEF BREAK THIS AFTERNOON... EXPECT SNOWS TO GET GOING IN EARNEST THIS EVENING...WITH INITIAL FOCUS IN FAVORED WEST FLOW AREAS...WITH A SLIGHT SOUTHWARD TREND EXPECTED DURING THE OVERNIGHT TOWARD THE M-32 CORRIDOR. SNOWFALL AMOUNTS COULD BE QUITE IMPRESSIVE...WITH STRONG OMEGA CENTERED RIGHT IN PRIME DGZ RIGHT THROUGH THE OVERNIGHT. DESPITE SOME FRAGMENTATION OF FLAKES FROM VERY GUSTY WINDS (MORE ON THE WINDS TO FOLLOW)...EXPECT SNOW TO LIQUID RATIOS TO PUSH 20 TO 1...PERHAPS EVEN HIGHER IF STRONG LOW LEVEL CONVERGENCE UNDER BANDS HELP SLACKING THE WIND FIELDS. SLIGHT SOUTHWARD DRIFT LOOKS TO BE THE ONLY THING FROM PREVENTING SNOW AMOUNTS FROM GETTING TOO OUT OF HAND. STILL...COULD EASILY SEE PARTS OF CHARLEVOIX/ANTRIM/OTSEGO/EMMET/CHEBOYGAN COUNTIES EXCEEDING 8 INCHES BY MORNING...WITH THE HIGHEST AMOUNTS JUST DOWNWIND OF LITTLE TRAVERSE BAY. ANY SLOWER DRIFT OF BANDS THAN CURRENTLY ANTICIPATED WILL RESULT IN LOCALLY HIGHER AMOUNTS. FURTHER SOUTH...COMPLETE LACK OF A LAKE SUPERIOR CONNECTION REALLY SHORTENS THE EFFECTIVE FETCH LENGTH. SO...DESPITE EXCELLENT INSTABILITY...JUST NOT SEEING THE OPPORTUNITY FOR A WHOLE LOT OF ACCUMULATION ALONG AND SOUTH OF THE M- 72 CORRIDOR. HOWEVER...GUSTY WINDS OF 20 TO 30 MPH WILL MAKE FOR SOME NASTY CONDITIONS...CREATING AREAS OF BLOWING AND DRIFTING SNOW AND BRIEF PERIODS OF VERY LOW VISIBILITIES. OFF LAKE SUPERIOR: INITIAL FOCUS THIS EVENING LOOKS TO REMAIN WEST OF WHITEFISH POINT...REALLY TARGETING AREAS OVER NEAR MUNISING AND SENEY. WINDS BEGIN TO SHIFT MORE W/NW LATE...BRINGING ACCUMULATING SNOW BANDS INTO NORTHWEST CHIPPEWA COUNTY. LATER START AND SIGNALS FOR BEST LOW LEVEL CONVERGENCE TO REMAIN OFF TO THE WEST SUGGESTS LOWER SNOW TOTALS THAN THOSE TO THE SOUTH...WITH 2 TO 4 INCHES EXPECTED BY MORNING. STRONG WINDS WILL PUSH BANDS FURTHER INLAND THAN WHAT IS NORMAL...PERHAPS EVEN BRINGING PARTS OF NORTHWEST MACKINAC COUNTY SEVERAL INCHES BY MORNING. MORE SNOW WILL FALL IN ALL THE ABOVE AREAS TOMORROW...WITH SEVERAL MORE INCHES EXPECTED (SEE LONG TERM SECTION BELOW). HEADLINES: FOR NORTHERN LOWER...GIVEN GUSTY WINDS AND WHAT COULD BE WIDESPREAD BLOWING SNOW EVEN OUTSIDE THE BETTER SNOW BANDS...HAVE DECIDED TO FORGO THE SPECIFIC LAKE EFFECT HEADLINES FOR MORE GENERIC WINTER WEATHER HEADLINES. HIGHEST SNOW TOTAL AREA MENTIONED EARLIER WILL BE UPGRADED TO A WINTER STORM WARNING...STARTING AT 00Z THIS EVENING RUNNING RIGHT THROUGH TUESDAY. WINTER WEATHER ADVISORIES SHOULD DO FOR AREAS SOUTH OF M-72...AS WELL AS PARTS OF NORTHEAST LOWER AS STRONG WINDS HELP PUSH WEAKENING BANDS FAR INLAND. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 331 AM EST MON NOV 17 2014 HIGH IMPACT WEATHER POTENTIAL...PLENTY OF SNOW AND COLD DURING THE WORK WEEK. HEAVY LAKE EFFECT SNOW IN WNW/NW FLOW TUESDAY. SOME POTENTIAL FOR HEAVY LAKE EFFECT SNOW WED NIGHT TO THU NIGHT. TUESDAY...UPPER LOW WILL EJECT FROM NORTH OF LAKE HURON INTO EASTERN QUEBEC. ONE TRAILING SHORTWAVE WILL CROSS CENTRAL LOWER MI IN THE AFTERNOON...ANOTHER WEAK WAVE WILL DIG TOWARD EASTERN SUPERIOR. A 980MB SURFACE LOW STARTS THE MORNING IN CENTRAL QUEBEC...AND WILL ADVANCE NE. SUBSTANTIAL TROFFING LINGERS ACROSS THE AREA EARLY IN THE MORNING...THIS RELAXES AS THE UPPER LOW PULLS OUT...BUT LAKE- INDUCED TROFFING REMAINS EVIDENT THRU THE DAY. 1000-850MB WINDS REMAIN STEADY-STATE IN THE MORNING...WNW INTO NORTHERN LOWER AND NW INTO EASTERN UPPER. WINDS WILL BACK SOME DURING THE AFTERNOON...BY EARLY EVENING WE WILL SEE A W FETCH INTO NORTHERN LOWER AND WNW INTO EASTERN UPPER. PLENTY OF DEEP MOISTURE...HIGH INVERSION HEIGHTS (TO NEARLY 500MB)...AND DELTA T/S NEAR 20C SHOULD ENSURE RAMPAGING LAKE EFFECT SNOW IN THE MORNING HOURS. IN THE AFTERNOON...THE INVERSION LOWERS TOWARD 700MB WITH DRYING ALOFT. THAT WILL REDUCE SNOW INTENSITY SOMEWHAT...BUT BY AND LARGE PARAMETERS AND STILL VERY FAVORABLE. AS IS THE CASE FOR TONIGHT...THE LOW-LEVEL FLOW IS A LITTLE BACKED COMPARED TO PREVIOUS RUNS. IN NORTHERN LOWER...THIS REQUIRES ADJUSTING THE MAX SNOW TOTALS NORTHWARD SLIGHTLY. CHARLEVOIX/ANTRIM/OTSEGO ARE THE MAIN ONES UNDER THE GUN...BUT THE FETCH NOW SUPPORTS MORE SNOW IN SOUTHERN EMMET/CHEBOYGAN THAN IT DOES IN NORTHERN KALKASKA/CRAWFORD. 5-9 INCHES STILL LIKES A GOOD FORECAST FOR THE DAY IN THE HARDEST-HIT LOCALES...CENTERED ON ELMIRA. 1-4 INCHES WORKS ELSEWHERE IN NW LOWER...WHERE THE FETCH IS MUCH SHORTER AND HAS NO CONNECTION TO SUPERIOR. IN EASTERN UPPER...THE BACKED FLOW OPENS UP MORE OF CHIPPEWA...BUT SHOULD STILL KEEP THE STRONGEST BANDS WEST OF THE SAULT. BUT THINGS ARE LOOKING CONSIDERABLY MORE FAVORABLE UP THERE...AND WILL INCREASE WESTERN CHIP AND FAR NW MACK INTO THE 3-5 INCH RANGE. MAX TEMPS WILL BE MAINLY IN THE 20S. HOWEVER...IN THE HIGH TERRAIN IN THE SOUTH...WHERE MARINE MODIFICATION WILL BE SMALLER DUE TO THE SHORTER FETCH...SOME PLACES (LIKE CAD) WILL LIKELY NOT ESCAPE THE TEENS. (HARD TO BELIEVE IT/S ONLY MID-NOVEMBER.) TUE NIGHT/WED...NOT MUCH REST FOR THE SNOW-WEARY. CLIPPER SHORTWAVE WILL ADVANCE INTO THE WESTERN LAKES ON WED. ASSOCIATED SURFACE LOW WILL ADVANCE FROM THE UPPER MS VALLEY TO NORTHERN LOWER MI ON WED. LOW LEVEL FLOW WILL BACK TO THE SW TUE NIGHT...WITH MOISTENING OVERNIGHT. SOME POTENTIAL FOR SOME SNEAKY 1-3 INCH ACCUMS OVER THE TIP OF NORTHERN LOWER TUE EVENING. SYNOPTIC -SN MIGHT SNEAK INTO SW SECTIONS LATE TUE NIGHT...BUT THE BULK OF THE THAT WILL WAIT UNTIL WED. BY THEN...A SOUTH 1000-850MB FETCH SHOULD KEEP MOST OF THE LAKE- INDUCED NONSENSE AT BAY...OTHER THAN ALONG THE SOUTH SHORE OF UPPER MI (AND IT IS UNCERTAIN WHETHER SYNOPTIC PRECIP WILL MAKE IT THAT FAR NORTH). THIS SYSTEM DOES NOT LOOK LIKE A MAJOR PROBLEM...1-2 INCHES...ESPECIALLY SOUTH OF M-32. MIN TEMPS TEENS TO PERHAPS HIGH SINGLE DIGITS (YIKES). MAX TEMPS 20S. REST OF THE FORECAST...POST-CLIPPER LAKE EFFECT SNOW WILL OCCUR WED NIGHT INTO THU NIGHT...AIDED BY ANOTHER CLIPPER SHORTWAVE DROPPING IN FROM THE NW. THE SET-UP FOR HEAVY SNOW LOOKS BETTER IN EASTERN UPPER IN THIS EVENT...AS DEEPER MOISTURE WILL LINGER LONGER THERE VS MID-LEVEL DRY AIR TRYING TO ENTRAIN INTO THE SOUTHER/CENTRAL LAKES. REGARDLESS...LAKE EFFECT SHSN WILL AGAIN BE FAIRLY WIDESPREAD IN BOTH PENINSULAS. THOUGH THE MODELS TEND TO BE TOO FAST TO BREAK PATTERNS DOWN...ALL MODELS HAVE THE CURRENT ONE FALL APART AFTER THIS LAST CLIPPER. 500MB FLOW BECOMES CONSIDERABLY MORE ZONAL...AND MORE SEASONABLE AIR WILL FINALLY GET A CHANCE TO MOVE INTO THE REGION...ESPECIALLY BY THE TAIL END OF THE WEEKEND. A SOUTHERN STREAM SYSTEM MOVING INTO THE CENTRAL STATES WILL AMPLIFY WARM ADVECTION...AND INCREASE PRECIP CHANCES BY SUNDAY. THIS ACTUALLY LOOKS TO BE MOSTLY RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 632 AM EST MON NOV 17 2014 VFR TO MVFR AT APN...MVFR TO IFR ELSEWHERE IN LAKE EFFECT CLOUDS/SHSN. LOW PRESSURE ALONG THE NORTH SHORE OF SUPERIOR WILL MOVE EAST TODAY...BRINGING ANOTHER SHOT OF COLD AIR TO THE REGION. LAKE EFFECT SHSN TODAY WILL BECOME LESS ORGANIZED DUE TO VARYING WINDS AND DRYING ALOFT. HOWEVER...SHSN WILL RAMP UP TONIGHT IN THE SNOWBELTS OF FAR NORTHERN LOWER MICHIGAN...BETWEEN PLN AND GOV. WILL HAVE VARYING CONDITIONS TODAY...TENDING TO MVFR NEAR LAKE MI AND VFR AT APN. TONIGHT..LAKE MI TAF SITES WILL BE MAINLY IFR (LIFR LATE AT PLN)...WHILE APN BECOMES MVFR. WINDS WILL VEER W TODAY...STAY W AND INCREASE/BECOME GUSTY TONIGHT. && .MARINE... ISSUED AT 331 AM EST MON NOV 17 2014 STRONG SURGE OF CAA AND INCREASINGLY SHARP PRESSURE GRADIENT WILL BRING VERY GUSTY WINDS BY LATER TODAY RIGHT THROUGH TUESDAY. GREATEST IMPACT EXPECTED ACROSS NORTHERN LAKE MICHIGAN...WHERE GALE FORCE WEST WINDS ARE EXPECTED TO DEVELOP QUICKLY THIS EVENING. SCA CONDITIONS EXPECTED ELSEWHERE...ALTHOUGH WILL NEED TO BE ON THE LOOKOUT FOR SOME GALE GUSTS ALONG THE NORTHEAST LOWER COASTLINE. WINDS ARE EXPECTED TO SUBSIDE LATE TUESDAY...AND ESPECIALLY TUESDAY NIGHT. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY FOR MIZ018-020-023-025>028-031>033. WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY FOR MIZ016-017-019-021-022. LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ008-016. WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR MIZ008. LAKE EFFECT SNOW WARNING UNTIL 10 AM EST THIS MORNING FOR MIZ015. LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LMZ341. GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LMZ323-342-344>346. LS...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EST TUESDAY FOR LSZ321-322. && $$ SYNOPSIS...JAZ SHORT TERM...MSB LONG TERM...JAZ AVIATION...JAZ MARINE...MSB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 AM EST MON NOV 17 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EST MON NOV 17 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS INDICATE A DEEPENING UPR TROF OVER CENTRAL NAMERICA WITH CLOSED H5 LO OVER ONTARIO JUST NW OF LK SUP CAUSING 12HR H5 HGT FALLS UP TO 130M BTWN 16/12Z AND 17/00Z AT INL AND DRAWING H5 TEMPS CLOSE TO -40C S UNDER THE AXIS OF LOWEST HGTS. BAND OF DPVA/DEEP LYR QVECTOR CNVGC/AXIS OF MID LVL MSTR IN ADVANCE OF SHRTWV ROTATING ARND THE CLOSED LO IS CROSSING UPR MI EARLY THIS MRNG...BUT DRYNESS OF AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.16 INCH IS 45 PCT OF NORMAL/ IS GREATLY LIMITING THE COVERAGE/INTENSITY OF ACCOMPANYING LIGHT SN. THERE HAS BEEN SOME LIGHT SN OVER THE FAR E NEAR NEWBERRY WITH A SW WIND OFF NRN LK MI...BUT THE FLOW HAS NOT BACKED SUFFICIENTLY TO CAUSE THE HEAVIER SN SHOWERS IN MACKINAC COUNTY TO IMPACT LUCE/SCHOOLCRAFT COUNTIES. LOOKING TO THE W...THE 00Z H85/7 TEMPS WERE -17C/-27C AT INL /VS -14C AND -16C AT GRB/. THE 00Z INL IS QUITE MOIST ALMOST UP TO H5 WITHIN A DEEP CYC FLOW. THERE IS A SHARP SFC WSHFT FM W TO NW ALONG A SFC LO PRES TROF RUNNING THRU NRN MN INTO ADJACENT ONTARIO...WITH SFC REPORTS SHOWING SOME MODERATE SN ALONG AND JUST BEHIND THIS BNDRY. MAIN FOCUS IN THE SHORT TERM WL BE ON LES AMOUNTS/GOING HEADLINES ASSOCIATED WITH INCOMING COLD/MOIST AIRMASS. MADE NO CHANGES ATTM TO HEADLINES ISSUED BY THE PREVIOUS SHIFT. TODAY...AS CUTOFF H5 LO DEEPENS FURTHER AND SLIDES SLOWLY TO THE E ACROSS UPR MI...SHARP CYC LLVL FLOW IS FCST TO SLOWLY ENVELOP THE CWA W-E WITH A WSHFT FM WSW EARLY THIS MRNG TO NW BY LATE IN THE DAY EXCEPT OVER THE SE CWA. THE SHARPER LLVL CNVGC WL ARRIVE OVER THE W ARND 12Z AND RESULT IN INCRSG SN RATES DESPITE SOME DEEP LYR QVECTOR DVGC IN THE WAKE OF THE SHRTWV ROTATING THRU THE UPR LKS EARLY THIS MRNG. THE HIER RES MODELS HAVE CONSISTENTLY POINTED TO THE AREA ARND ONTONAGON COUNTY AS THE FOCUS FOR THE SHARPEST CNVGC. GOING START TIME OF 12Z FOR THE WARNINGS OVER THE W APPEARS TO BE ON TRACK. SINCE THE RATHER LO UVV MAX IN THE ABSENCE OF DEEP LYR FORCING WL BE CENTERED IN THE DGZ...EXPECT GOOD SN/WATER RATIOS IN EXCESS OF 20:1 DESPITE A DGZ DEPTH OF ONLY ABOUT 3K FT AND INCRSG WINDS THAT WOULD TEND TO FRAGMENT THE SN FLAKES. WITH SOME INCRSG DEEP LYR QVECTOR CNVGC/UVV OVER THE W HALF LATER IN THE DAY UNDER THE DEEPENING UPR TROF AXIS...FCST SDNGS ALSO INDICATE INCRSG DEEP MSTR THRU THE DAY PER THE 00Z INL RAOB WITH EQUILIBRIUM LVLS APRCHG 10K FT OVER THE BY LATER IN THE DAY AS H85/7 TEMPS DIP TO -16C TO -17C/-27C. INCRSG NW WINDS/DESTABILIZATION WL RESULT IN GUSTY SFC WINDS AND SOME BLSN AS WELL. FARTHER TO THE E...THE LLVL FLOW IS FCST TO BE OUT OF THE W MOST OF THE DAY...SO THE SN SHOWERS THERE SHOULD BE MAINLY CONFINED TO THE LK SHORE UNTIL AT LEAST 21Z...WHEN THE FASTER HI RES CNDN MODEL SHOWS THE ARRIVAL OF SHARPER CYC FLOW/ WSHFT TO THE NW. FCST LES WARNINGS FOR ALGER/NRN SCHOOLCRAFT COUNTIES BEGINS AT 21Z...SO WL NOT CHANGE THIS START TIME. THERE SHOULD BE NOTHING MORE THAN FLURRIES/LIGHT SN SHOWERS OVER THE SCENTRAL WITH DOWNSLOPE FLOW. TNGT...UPR TROF/AXIS OF DEEP LYR QVECTOR CNVGC AND MSTR/SFC LO PRES TROF AND CYC WSHFT TO THE NW ARE PROGGED TO DRIFT SLOWLY E. THESE TRENDS WL RESULT IN INCRSG POPS/SN RATES IN THE NW SN BELTS MAINLY E OF MARQUETTE. THE 00Z NAM AND ESPECIALLY THE HI RES CNDN MODEL HINT LK NIPIGON MOISTENING WL GREATLY ENHANCE SN RATES OVER ALGER/NRN SCHOOLCRAFT COUNTIES...SO THE GOING WRNGS APPEAR ON TRACK. AS WL BE THE CASE TODAY OVER THE W...HI EQUILIBRIUM LVL AND FAVORABLE UVV MAX WITHIN THE DGZ WL BE ENHANCING FACTORS FOR SN RATES IN THIS AREA. ALTHOUGH THE DEPARTURE OF THE DYANAMIC SUPPORT/VERY DEEP MSTR MAY SLOW DOWN THE HEAVY SN RATES OVER THE W BY THE OVERNGT HRS... LINGERING CYC NW BACKING TOWARD THE WNW OVER THE FAR W TOWARD 12Z WL CONTINUE WIDESPREAD SN SHOWERS/CATEGORICAL POPS IN THE FAVORED SN BELTS THERE. ALTHOUGH THE EXPECTED NW FLOW IS NOT FAVORABLE FOR MARQUETTE COUNTY...WL CONTINUE THE ADVY FOR THIS AREA GIVEN POTENTIAL FOR HIER WINDS NEAR THE LK SHORE AND HEAVIER SN IN THE EASTERN PART OF THE COUNTY. ONCE AGAIN...THE LIGHTEST AND LEAST WIDESPREAD SN SHOWERS WL BE OVER THE SCENTRAL. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 519 PM EST SUN NOV 16 2014 MONDAY NIGHT...THE MID LEVEL TROUGH OVER CENTRAL UPPER MI AT 00Z/TUE IS EXPECTED TO MOVE THROUGH NRN LAKE HURON BY TUE MORNING AS THE SFC TROUGH ALSO SLIDES THROUGH NRN LOWER MICHIGAN. CYCLONIC NW LOW LEVEL FLOW WILL PREVAIL ACROSS UPPER WITH VERY COLD AIR MOVING IN AS CAA DROP 850/700 MB TEMPS TO AROUND -17C/-26C. INSTABILITY WILL BE VERY FAVORALB FOR HEAVY LES WITH LAKE INDUCED CAPE VALUES TO NEAR 1K J/KG AND EQUILIBRIUM LEVELS TO NEAR 17K FT. STRONG UPWARD MOTION IN THE 3K-6K FT DGZ WILL SUPPORT SLR VALUES AOA 20/1 BUT WILL BE LIMITED BY FRACTURING/COMPACTION WITH THE STRONG WINDS. THE MAIN QUESTION WILL BE THE POSITION/DURATION OF THE HEAVY BANDS WITH THE GRADUALLY SHIFTING WINDS. THE 330 FLOW GRADUALLY BACKING OVERNIGHT SHOULD BRING THE HEAVIEST SNOW INTO THE WEST FROM IWD TO ROCKLAND AND INTO ALGER COUNTY OVER THE EAST. SNOWFALL RATES OF AT LEAST AN INCH OR TWO PER HOUR ARE EXPECTED AT TIMES WITH ADDITIONAL AMOUNTS OF 4 TO 8 INCHES OVER THE WEST AND TO NEAR 10 INCHES INTO ALGER AND NW SCHOOLCRAFT COUNTY. THE STRONG WINDS SHOULD ALSO PUSH SOME OF THE HEAVIER SNOW INTO SRN SCHOOLCRAFT COUNTY. THERE IS MORE UNCERTAINTY WITH THE SNOWFALL AMOUNTS INTO MARQUETTE COUNTY AS THE LOW LEVEL WIND LINES UP PARALLEL TO THE SHORELINE FROM BIG BAY TO MARQUETTE. EXPECT THERE WILL BE A PERIOD WHERE WINDS VEER ENOUGH SO THAT THE TRAJECTORIES STILL BRING SOME OF THE HEAVIER BANDS INTO THE NORTH AND EAST PARTS OF THE COUNTY FROM BIG BAY AND THE HURON MOUNTAINS TO NEGAUNEE AND MARQUETTE. HOWEVER...THERE IS LOWER CONFIDENCE THAT THE HEAVY BANDS WILL PERSIST LONG ENOUGH TO PRODUCE WARNING AMOUNTS SNOW TOTALS (8 INCHES OR GREATER IN 12 HOURS). THE STRONG WINDS GUSTING INTO THE 30 TO 40 MPH RANGE NEAR THE SHORE WILL PRODUCE CONSIDERABLE BLSN WITH VERY POOR VSBY IN THE HEAVIER BANDS. TUE...AS THE MID LEVEL TROUGH MOVES AWAY WITH QVECTOR DIV..SUBSIDENCE AND LOWERING INVERSION HEIGHTS AND STEADILY BACKING LOW LEVEL WINDS WITH THE APPROACH OF THE SFC RIDGE THE LES WILL DIMINISH...ESPECIALLY OVER THE WEST. HOWEVER... THE LONGER FETCH INTO THE EAST COULD STILL SUPPORT ADDITIONAL AMOUNTS IN THE 3 TO 6 INCH RANGE FROM MUNISING EASTWARD. TUE NIGHT...WITH THE WINDS BACKING TO WESTERLY THERE MAY BE PERIOD WHEN LOW LEVEL CONV FAVORS A STRONGER BAND INTO THE KEWEENAW WITH A BRIEF PERIOD OF HEAVIER SNOW. OTHERWISE...THE LES IS EXPECTED TO END OVER THE REST OF THE CWA AS WINDS BECOME SW. WED-THU...A COUPLE OF SHORTWAVE TROUGHS DIVING SE INTO THE NRN LAKES WILL REINFORCE THE COLD AIR OVER THE REGION AND REINVIGORATE THE LES FOR LOCATIONS FAVORED BY WNW FLOW. ADDITIONAL HEADLINES MAY EVENTUALLY BE NEEDED FOR ANOTHER ROUND OF HEAVIER SNOW. AWAY FROM THE LES SNOWBELTS...THERE MAY ALSO BE SOME LIGHT SNOW SHOWERS WITH THE SHRTWV AND SFC TROUGH ON WED. HOWEVER...AWAY FROM THE SNOWBELTS ACCUMULATIONS SHOULD REMAIN LESS THAN AN INCH. FRI-SAT...A MODERATING TREND IS EXPECTED AS THE PATTERN BECOMES LESS AMPLIFIED. WAA WITH SW FLOW BY SAT COULD BRING TEMPS BACK TO AROUND 30F...STILL BELOW NORMAL. THERE IS MORE UNCERTAINTY BY SUN AS THE MODELS SUGGEST AT A SHORTWAVE MOVING OUT OF THE SRN/CNTRL PLAINS AND ACCOMPANYING AREA OF PCPN COULD AFFECT THE AREA. THE 12Z/16 ECMWF EVEN BRINGS IN ENOUGH WARM AIR FOR MAINLY RAIN BY SAT NIGHT AND SUN. HOWEVER...CONFIDENCE IN EITHER PCPN POTENTIAL/TYPE/AMOUNT IS LOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1200 AM EST MON NOV 17 2014 SFC LOW OVER NORTHERN LK SUPERIOR WILL SLIDE EAST THROUGH THE MORNING WHILE DRAGGING A COLD FRONT OVER UPR MICHIGAN. EXPECT VFR TO MVFR CONDITIONS TO TREND IFR /MAINLY VSBY/ IN MODERATE TO HEAVY LAKE EFFECT SNOW SHOWERS BY DAYBREAK THIS MORNING AT KIWD AND KCMX BEHIND THE FRONT. IFR CONDITIONS WILL CONTINUE THROUGH THE END OF THE TAF PERIOD WITH SOME LIFR CONDITIONS POSSIBLE DURING HEAVIEST SNOW SHOWERS. WINDS WILL BECOME GUSTY FM THE NORTHWEST BY THIS AFTN WITH GUSTS OVER 30 KTS AT THE MORE EXPOSED KCMX LOCATION. MAINLY MVFR CONDITIONS AT KSAW THROUGH MOST OF THE DAY...BUT WILL GO FOR IFR VSBY LATE THIS AFTN WITH ARRIVAL OF DEEPER MOISTURE AND WIDESPREAD SNOW SHOWERS. WINDS WILL BECOME GUSTY BY LATE AFTN AT KSAW AS WELL...WITH GUSTS OVER 25 KTS INTO THIS EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 314 PM EST SUN NOV 16 2014 LOW PRESSURE WILL CROSS LAKE SUPERIOR TONIGHT INTO MONDAY MORNING WHILE DEEPENING. THE LOW WILL THEN EXIT THROUGH FAR E ONTARIO MONDAY AFTERNOON. LOOK FOR GUSTS TO INCREASE TO GALES OF 35-40KTS OVER PORTIONS OF W LAKE SUPERIOR MONDAY AFTERNOON...BEFORE EXPANDING TO THE E HALF OF LAKE SUPERIOR LATE MONDAY EVENING THROUGH EARLY TUESDAY. GALE WATCH HAS BEEN UPGRADED TO A GALE WARNING. A TROUGH WILL THEN LINGER ACROSS LAKE SUPERIOR THROUGH TUESDAY MORNING...BEFORE BRIEFLY BEING REPLACED BY A RIDGE TUESDAY AFTERNOON AND EVENING. ANOTHER TROUGH OVER N MANITOBA ON TUESDAY WILL SLIDE ACROSS THE UPPER GREAT LAKES LATE TUESDAY NIGHT THROUGH WEDNESDAY...BEFORE EXITING ACROSS THE ONTARIO AND QUEBEC BORDER THURSDAY MORNING. HIGH PRESSURE OVER THE N PLAINS ON THURSDAY WILL DIVE ACROSS THE OHIO VALLEY LATE FRIDAY...EXTENDING A RIDGE OVER THE UPPER GREAT LAKES ON FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY FROM 9 AM THIS MORNING TO 7 AM EST TUESDAY FOR MIZ004-084. LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR MIZ006-085. LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ TUESDAY FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR MIZ007. LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST TUESDAY FOR MIZ005. LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST TUESDAY FOR MIZ014. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 1 PM EST TUESDAY FOR LSZ251-267. GALE WARNING FROM 4 PM THIS AFTERNOON TO 1 PM EST TUESDAY FOR LSZ248>250-265-266. GALE WARNING FROM 1 PM THIS AFTERNOON TO 9 AM EST TUESDAY FOR LSZ264. GALE WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO 4 AM EST /3 AM CST/ TUESDAY FOR LSZ240>242-263. GALE WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST TUESDAY FOR LSZ243>245. GALE WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO 1 AM EST /MIDNIGHT CST/ TUESDAY FOR LSZ162. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLB AVIATION...JLA MARINE...KF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
335 AM EST MON NOV 17 2014 .SYNOPSIS... ISSUED AT 331 AM EST MON NOV 17 2014 LOW PRESSURE PASSING TO OUR NORTH TODAY...WILL USHER IN ANOTHER SURGE OF COLD AIR. LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN SOME PLACES TODAY...BUT HEAVY SNOW IS EXPECTED TONIGHT AND TUESDAY IN SOME OF THE CLASSIC SNOWBELTS. ANOTHER SYSTEM WILL BRING LIGHT SNOW TO THE REGION WEDNESDAY...AND MORE LAKE EFFECT SNOW WILL FOLLOW BEHIND IT. HOWEVER...TEMPERATURES WILL BECOME MILDER DURING THE UPCOMING WEEKEND. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 331 AM EST MON NOV 17 2014 ...SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED LATER TODAY THROUGH TUESDAY... HIGH IMPACT WEATHER POTENTIAL: LOCALIZED VERY HEAVY LAKE EFFECT SNOW. AREAS OF BLOWING SNOW AND NEAR WHITEOUT CONDITIONS POSSIBLE TONIGHT. PATTERN SYNOPSIS/CURRENT CONDITIONS: KINDA STATING THE OBVIOUS...BUT MID-WINTER LIKE PATTERN WELL ESTABLISHED ACROSS THE NORTHERN LAKES. REASON FOR SUCH IS ONE ANOMALOUSLY DEEP MERIDIONAL FLOW REGIME...CONSISTING OF FULL LENGTH WESTERN NOAM RIDGING AND JUST AS IMPRESSIVE TROUGHING EXTENDING THROUGH THE CENTRAL PLAINS INTO THE WESTERN LAKES. MOST IMPRESSIVE COLD SURGE YET TIED TO WAVE OF ARCTIC ORIGIN DIVING INTO SOUTHWEST ONTARIO AND INTO MINNESOTA (-20C H8 TEMPERATURES PER LATEST RAP ANALYSIS!). SURFACE COLD FRONT RUNNING WELL AHEAD OF THIS WAVE...ALREADY PUSHING INTO NORTHWEST MICHIGAN AT THIS EARLY HOUR. AREA OUT AHEAD OF THIS FRONT PLENTY COLD ENOUGH TO CONTINUE TO ENTICE A SIGNIFICANT LAKE RESPONSE (A PRETTY RARE FEAT TO HAVE SUCH COLD PRE-FRONTAL AIR DURING MID NOVEMBER). MAIN SHOW TONIGHT HAS BEEN DIRECTED INTO PARTS OF EASTERN UPPER MICHIGAN.. WHERE NO DOUBT SEVERAL INCHES OF ACCUMULATION HAVE ALREADY OCCURRED. SOMEWHAT LIGHTER MORE NUISANCE TYPE SNOWS IMPACTING NORTHER LOWER...ALTHOUGH SOME EMBEDDED HEAVIER LAKE ENHANCED SNOWS WERE NOTED...ESPECIALLY ACROSS PARTS OF EMMET COUNTY. SIMPLY NO END IN SIGHT...WITH CURRENT UPSTREAM WAVE SET TO AMPLIFY OVERHEAD LATER TODAY AND TONIGHT...FORCING A SHIFTING OF THE WINDS TO MORE W/NW AND PUTTING THE MORE TRADITIONAL LAKE EFFECT AREAS UNDER THE GUN FOR A HIGH IMPACT WINTER WEATHER EVENT. PRIMARY FORECAST CONCERNS/CHALLENGES: MULTIPLE! INITIAL FOCUS ON ONGOING SW FLOW LAKE EFFECT AND ASSOCIATED HEADLINES THIS MORNING. OVERNIGHT FOCUS ON MUCH MORE WIDESPREAD LAKE SNOW EVENT...INCLUDING AMOUNTS AND HEADLINE MANAGEMENT CONCERNS. DETAILS: NOT PRETTY! FIRST OFF...ONGOING SW FLOW LAKE SNOWS SHOULD STEADILY DECLINE IN INTENSITY SHORTLY AFTER 09Z AS WINDS BEGIN TO SLOWLY VEER AND BRIEF CORRIDOR OF UPSTREAM DRIER AIR OVERSPEADS THE LAKES. CURRENT HEADLINES RUN THROUGH 15Z...WHICH OFFERS SOME FLEXIBILITY IF BANDS SHOULD PERSIST LONGER THAN ANTICIPATED (NEVER SEEN THAN BEFORE :)). NO OFFICIAL REPORTS JUST YET...BUT BASED OFF MACKINAC BRIDGE WEB CAMS AND SOME INFORMATION GLEANED FROM CALLING ST. IGNACE...GOTTA FEELING WE WILL BE DEALING WITH SOME IMPRESSIVE SNOWFALL TOTALS UP IN THE STRAITS AREA BEFORE ALL IS SAID AND DONE THIS MORNING. ELSEWHERE...JUST SOME LIGHTER SNOWS EXPECTED AS THE COLD FRONT PUSHES EAST...EXITING STAGE RIGHT BY MID-MORNING. WITH PART ONE DONE...ALL FOCUS SHIFTS TO WHAT INCREASINGLY LOOKS LIKE A VERY SIGNIFICANT AND PROLONGED LAKE EFFECT EVENT FOR THE MORE TRADITIONAL SNOW BELTS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN. CURRENT SOUTHWEST ONTARIO WAVE CONTINUES TO DIG...SLOWLY CROSSING THE NORTHERN LAKES THROUGH THE OVERNIGHT. DESPITE MAIN CORE OF ATTENDANT CAA ACTUALLY PASSING US BY TO THE SOUTH...INSTABILITY RAMPS UP IMPRESSIVELY LATE TODAY THROUGH THE OVERNIGHT...WITH NEAR EXTREME DELTA T/S COLLOCATED WITH DEEP SYNOPTIC MOISTURE SUPPORT AND ESSENTIALLY ALL LOSS OF AN INVERSION. CYCLONIC FLOW IS IMPRESSIVE... SUGGESTING ENHANCED CONVERGENCE TARGETING NORTHWEST LOWER MICHIGAN. LOW LEVEL FLOW IS SLIGHTLY MORE BACKED IN RECENT GUIDANCE RUNS...WELL SUPPORTED BY WHAT SHOULD BE STRENGTHENING LAKE DRIVEN SURFACE TROUGH DEVELOPMENT. AFTER A BRIEF BREAK THIS AFTERNOON... EXPECT SNOWS TO GET GOING IN EARNEST THIS EVENING...WITH INITIAL FOCUS IN FAVORED WEST FLOW AREAS...WITH A SLIGHT SOUTHWARD TREND EXPECTED DURING THE OVERNIGHT TOWARD THE M-32 CORRIDOR. SNOWFALL AMOUNTS COULD BE QUITE IMPRESSIVE...WITH STRONG OMEGA CENTERED RIGHT IN PRIME DGZ RIGHT THROUGH THE OVERNIGHT. DESPITE SOME FRAGMENTATION OF FLAKES FROM VERY GUSTY WINDS (MORE ON THE WINDS TO FOLLOW)...EXPECT SNOW TO LIQUID RATIOS TO PUSH 20 TO 1...PERHAPS EVEN HIGHER IF STRONG LOW LEVEL CONVERGENCE UNDER BANDS HELP SLACKING THE WIND FIELDS. SLIGHT SOUTHWARD DRIFT LOOKS TO BE THE ONLY THING FROM PREVENTING SNOW AMOUNTS FROM GETTING TOO OUT OF HAND. STILL...COULD EASILY SEE PARTS OF CHARLEVOIX/ANTRIM/OTSEGO/EMMET/CHEBOYGAN COUNTIES EXCEEDING 8 INCHES BY MORNING...WITH THE HIGHEST AMOUNTS JUST DOWNWIND OF LITTLE TRAVERSE BAY. ANY SLOWER DRIFT OF BANDS THAN CURRENTLY ANTICIPATED WILL RESULT IN LOCALLY HIGHER AMOUNTS. FURTHER SOUTH...COMPLETE LACK OF A LAKE SUPERIOR CONNECTION REALLY SHORTENS THE EFFECTIVE FETCH LENGTH. SO...DESPITE EXCELLENT INSTABILITY...JUST NOT SEEING THE OPPORTUNITY FOR A WHOLE LOT OF ACCUMULATION ALONG AND SOUTH OF THE M- 72 CORRIDOR. HOWEVER...GUSTY WINDS OF 20 TO 30 MPH WILL MAKE FOR SOME NASTY CONDITIONS...CREATING AREAS OF BLOWING AND DRIFTING SNOW AND BRIEF PERIODS OF VERY LOW VISIBILITIES. OFF LAKE SUPERIOR: INITIAL FOCUS THIS EVENING LOOKS TO REMAIN WEST OF WHITEFISH POINT...REALLY TARGETING AREAS OVER NEAR MUNISING AND SENEY. WINDS BEGIN TO SHIFT MORE W/NW LATE...BRINGING ACCUMULATING SNOW BANDS INTO NORTHWEST CHIPPEWA COUNTY. LATER START AND SIGNALS FOR BEST LOW LEVEL CONVERGENCE TO REMAIN OFF TO THE WEST SUGGESTS LOWER SNOW TOTALS THAN THOSE TO THE SOUTH...WITH 2 TO 4 INCHES EXPECTED BY MORNING. STRONG WINDS WILL PUSH BANDS FURTHER INLAND THAN WHAT IS NORMAL...PERHAPS EVEN BRINGING PARTS OF NORTHWEST MACKINAC COUNTY SEVERAL INCHES BY MORNING. MORE SNOW WILL FALL IN ALL THE ABOVE AREAS TOMORROW...WITH SEVERAL MORE INCHES EXPECTED (SEE LONG TERM SECTION BELOW). HEADLINES: FOR NORTHERN LOWER...GIVEN GUSTY WINDS AND WHAT COULD BE WIDESPREAD BLOWING SNOW EVEN OUTSIDE THE BETTER SNOW BANDS...HAVE DECIDED TO FORGO THE SPECIFIC LAKE EFFECT HEADLINES FOR MORE GENERIC WINTER WEATHER HEADLINES. HIGHEST SNOW TOTAL AREA MENTIONED EARLIER WILL BE UPGRADED TO A WINTER STORM WARNING...STARTING AT 00Z THIS EVENING RUNNING RIGHT THROUGH TUESDAY. WINTER WEATHER ADVISORIES SHOULD DO FOR AREAS SOUTH OF M-72...AS WELL AS PARTS OF NORTHEAST LOWER AS STRONG WINDS HELP PUSH WEAKENING BANDS FAR INLAND. && .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 331 AM EST MON NOV 17 2014 HIGH IMPACT WEATHER POTENTIAL...PLENTY OF SNOW AND COLD DURING THE WORK WEEK. HEAVY LAKE EFFECT SNOW IN WNW/NW FLOW TUESDAY. SOME POTENTIAL FOR HEAVY LAKE EFFECT SNOW WED NIGHT TO THU NIGHT. TUESDAY...UPPER LOW WILL EJECT FROM NORTH OF LAKE HURON INTO EASTERN QUEBEC. ONE TRAILING SHORTWAVE WILL CROSS CENTRAL LOWER MI IN THE AFTERNOON...ANOTHER WEAK WAVE WILL DIG TOWARD EASTERN SUPERIOR. A 980MB SURFACE LOW STARTS THE MORNING IN CENTRAL QUEBEC...AND WILL ADVANCE NE. SUBSTANTIAL TROFFING LINGERS ACROSS THE AREA EARLY IN THE MORNING...THIS RELAXES AS THE UPPER LOW PULLS OUT...BUT LAKE- INDUCED TROFFING REMAINS EVIDENT THRU THE DAY. 1000-850MB WINDS REMAIN STEADY-STATE IN THE MORNING...WNW INTO NORTHERN LOWER AND NW INTO EASTERN UPPER. WINDS WILL BACK SOME DURING THE AFTERNOON...BY EARLY EVENING WE WILL SEE A W FETCH INTO NORTHERN LOWER AND WNW INTO EASTERN UPPER. PLENTY OF DEEP MOISTURE...HIGH INVERSION HEIGHTS (TO NEARLY 500MB)...AND DELTA T/S NEAR 20C SHOULD ENSURE RAMPAGING LAKE EFFECT SNOW IN THE MORNING HOURS. IN THE AFTERNOON...THE INVERSION LOWERS TOWARD 700MB WITH DRYING ALOFT. THAT WILL REDUCE SNOW INTENSITY SOMEWHAT...BUT BY AND LARGE PARAMETERS AND STILL VERY FAVORABLE. AS IS THE CASE FOR TONIGHT...THE LOW-LEVEL FLOW IS A LITTLE BACKED COMPARED TO PREVIOUS RUNS. IN NORTHERN LOWER...THIS REQUIRES ADJUSTING THE MAX SNOW TOTALS NORTHWARD SLIGHTLY. CHARLEVOIX/ANTRIM/OTSEGO ARE THE MAIN ONES UNDER THE GUN...BUT THE FETCH NOW SUPPORTS MORE SNOW IN SOUTHERN EMMET/CHEBOYGAN THAN IT DOES IN NORTHERN KALKASKA/CRAWFORD. 5-9 INCHES STILL LIKES A GOOD FORECAST FOR THE DAY IN THE HARDEST-HIT LOCALES...CENTERED ON ELMIRA. 1-4 INCHES WORKS ELSEWHERE IN NW LOWER...WHERE THE FETCH IS MUCH SHORTER AND HAS NO CONNECTION TO SUPERIOR. IN EASTERN UPPER...THE BACKED FLOW OPENS UP MORE OF CHIPPEWA...BUT SHOULD STILL KEEP THE STRONGEST BANDS WEST OF THE SAULT. BUT THINGS ARE LOOKING CONSIDERABLY MORE FAVORABLE UP THERE...AND WILL INCREASE WESTERN CHIP AND FAR NW MACK INTO THE 3-5 INCH RANGE. MAX TEMPS WILL BE MAINLY IN THE 20S. HOWEVER...IN THE HIGH TERRAIN IN THE SOUTH...WHERE MARINE MODIFICATION WILL BE SMALLER DUE TO THE SHORTER FETCH...SOME PLACES (LIKE CAD) WILL LIKELY NOT ESCAPE THE TEENS. (HARD TO BELIEVE IT/S ONLY MID-NOVEMBER.) TUE NIGHT/WED...NOT MUCH REST FOR THE SNOW-WEARY. CLIPPER SHORTWAVE WILL ADVANCE INTO THE WESTERN LAKES ON WED. ASSOCIATED SURFACE LOW WILL ADVANCE FROM THE UPPER MS VALLEY TO NORTHERN LOWER MI ON WED. LOW LEVEL FLOW WILL BACK TO THE SW TUE NIGHT...WITH MOISTENING OVERNIGHT. SOME POTENTIAL FOR SOME SNEAKY 1-3 INCH ACCUMS OVER THE TIP OF NORTHERN LOWER TUE EVENING. SYNOPTIC -SN MIGHT SNEAK INTO SW SECTIONS LATE TUE NIGHT...BUT THE BULK OF THE THAT WILL WAIT UNTIL WED. BY THEN...A SOUTH 1000-850MB FETCH SHOULD KEEP MOST OF THE LAKE- INDUCED NONSENSE AT BAY...OTHER THAN ALONG THE SOUTH SHORE OF UPPER MI (AND IT IS UNCERTAIN WHETHER SYNOPTIC PRECIP WILL MAKE IT THAT FAR NORTH). THIS SYSTEM DOES NOT LOOK LIKE A MAJOR PROBLEM...1-2 INCHES...ESPECIALLY SOUTH OF M-32. MIN TEMPS TEENS TO PERHAPS HIGH SINGLE DIGITS (YIKES). MAX TEMPS 20S. REST OF THE FORECAST...POST-CLIPPER LAKE EFFECT SNOW WILL OCCUR WED NIGHT INTO THU NIGHT...AIDED BY ANOTHER CLIPPER SHORTWAVE DROPPING IN FROM THE NW. THE SET-UP FOR HEAVY SNOW LOOKS BETTER IN EASTERN UPPER IN THIS EVENT...AS DEEPER MOISTURE WILL LINGER LONGER THERE VS MID-LEVEL DRY AIR TRYING TO ENTRAIN INTO THE SOUTHER/CENTRAL LAKES. REGARDLESS...LAKE EFFECT SHSN WILL AGAIN BE FAIRLY WIDESPREAD IN BOTH PENINSULAS. THOUGH THE MODELS TEND TO BE TOO FAST TO BREAK PATTERNS DOWN...ALL MODELS HAVE THE CURRENT ONE FALL APART AFTER THIS LAST CLIPPER. 500MB FLOW BECOMES CONSIDERABLY MORE ZONAL...AND MORE SEASONABLE AIR WILL FINALLY GET A CHANCE TO MOVE INTO THE REGION...ESPECIALLY BY THE TAIL END OF THE WEEKEND. A SOUTHERN STREAM SYSTEM MOVING INTO THE CENTRAL STATES WILL AMPLIFY WARM ADVECTION...AND INCREASE PRECIP CHANCES BY SUNDAY. THIS ACTUALLY LOOKS TO BE MOSTLY RAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1145 PM EST SUN NOV 16 2014 S/SW FLOW LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO TARGET OUR NW LWR MICHIGAN TAF SITES (PLN/TVC/MBL)THROUGH MONDAY...DROPPING CONDITIONS TO IFR WITHIN HEAVIER SNOW BANDS. APN WILL REMAIN VFR THRU MONDAY AWAY FROM THE LAKE SNOW SHOWERS...WITH JUST A PASSING LIGHT SNOW SHOWER EXPECTED. S/SW WINDS WILL REMAIN AOB 10 KTS THRU THE FORECAST PERIOD. && .MARINE... ISSUED AT 331 AM EST MON NOV 17 2014 STRONG SURGE OF CAA AND INCREASINGLY SHARP PRESSURE GRADIENT WILL BRING VERY GUSTY WINDS BY LATER TODAY RIGHT THROUGH TUESDAY. GREATEST IMPACT EXPECTED ACROSS NORTHERN LAKE MICHIGAN...WHERE GALE FORCE WEST WINDS ARE EXPECTED TO DEVELOP QUICKLY THIS EVENING. SCA CONDITIONS EXPECTED ELSEWHERE...ALTHOUGH WILL NEED TO BE ON THE LOOKOUT FOR SOME GALE GUSTS ALONG THE NORTHEAST LOWER COASTLINE. WINDS ARE EXPECTED TO SUBSIDE LATE TUESDAY...AND ESPECIALLY TUESDAY NIGHT. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY FOR MIZ018-020-023-025>028-031>033. WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY FOR MIZ016-017-019-021-022. LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ008-016. WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR MIZ008. LAKE EFFECT SNOW WARNING UNTIL 10 AM EST THIS MORNING FOR MIZ015. LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LMZ341. GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST TUESDAY FOR LMZ323-342-344>346. LS...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EST TUESDAY FOR LSZ321-322. && $$ SYNOPSIS...JAZ SHORT TERM...MSB LONG TERM...JAZ AVIATION...MLR MARINE...MSB
AREA FORECAST DISCUSSION
NWS DULUTH MN
353 PM CST MON NOV 17 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 352 PM CST MON NOV 17 2014 AT 352 PM...SNOW HAD STARTED TO INTENSIFY ALONG PORTIONS OF THE GOGEBIC RANGE OF IRON COUNTY. OUR SNOWFALL OBSERVER IN GILE REPORTED 1 INCH OF NEW SNOWFALL TODAY...BUT IT HAD JUST RECENTLY STARTED TO INTENSIFY. FURTHER WEST...4 INCHES OF SNOW HAD FALLEN IN THE IRON RIVER AREA...FROM PERSISTENT LIGHT SNOW THAT HAD SET UP IN THAT AREA EARLIER TODAY. THE REMAINDER OF THE CWA WAS GENERALLY SEEING PARTLY TO MOSTLY CLOUDY SKIES AND SCATTERED SNOW SHOWERS. ASIDE FROM THE SOUTH SHORE THERE WAS LITTLE SNOW ACCUMULATION. THE MAIN FOCUS FOR TONIGHT IS DEFINITELY THE SOUTH SHORE LAKE EFFECT SNOWFALL EVENT. FORECAST SOUNDINGS LOOK QUITE FAVORABLE OVERNIGHT...ALBEIT A BIT TOO WESTERLY FOR PORTIONS OF THE NIGHT. HIGH RESOLUTION MODELING...INCLUDING THE HRRR AND THE WRF INDICATE SNOW SQUALLS WILL BECOME INTENSE DURING THE EVENING...AND THEN REMAIN THAT WAY FOR MUCH OF THE NIGHT. FORECAST SOUNDINGS AND BUFKIT ANALYSIS INDICATES EXTREME INSTABILITY AND INVERSION HEIGHTS OF UP TO AN AMAZING 5 KM. INVERSION HEIGHTS CRASH DURING THE DAY TUESDAY...BUT WINDS WILL BECOME MORE WESTERLY AS THE DAY WEARS ON...DRAMATICALLY REDUCING THE LAKE EFFECT POTENTIAL. WILL CONTINUE WITH THE LAKE EFFECT SNOW WARNING FOR THE GOGEBIC RANGE AREA...FOR A TOTAL OF 8 TO 14 INCHES. FURTHER WEST...WILL CONTINUE THE ADVISORY FOR BAYFIELD COUNTY...WITH GENERALLY 4 TO 8 INCHES. LOWS TONIGHT WILL BE THE OTHER ISSUE. WIND CHILL READINGS MAY DROP TO AS LOW AS 15 TO 20 BELOW IN MUCH OF NORTHEASTERN MINNESOTA OVERNIGHT. WINDS WILL REMAIN A BIT GUSTY THROUGHOUT THE NIGHT. OTHERWISE OVERNIGHT...WE SHOULD SEE PARTLY TO MOSTLY CLOUDY SKIES AND ISOLATED TO SCATTERED SNOW SHOWERS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 352 PM CST MON NOV 17 2014 COLD AND CLOUDY WEATHER TO BEGIN THE LONG TERM PERIOD WITH A BRIEF WARM UP EXPECTED THIS WEEKEND. PRECIPITATION CHANCES ARE LOW OVERALL WITH A FEW CHANCES FOR SNOW ON WEDNESDAY AND LATE IN THE WEEKEND. WEDNESDAY/THURSDAY...GOOD CHANCE FOR LIGHT ACCUMULATIONS ON WEDNESDAY GENERALLY NORTH OF HIGHWAY 2...WITH THE BEST CHANCE FROM INTERNATIONAL FALLS EAST THROUGH THE TIP OF THE ARROWHEAD REGION. THIS WILL BE CAUSED BY AN ELONGATED MID-LEVEL DISTURBANCE MOVING SOUTH OUT OF MANITOBA ALONG A DEEPENING UPPER LOW. THIS UPPER LOW WILL QUICKLY MOVE SOUTHEAST OVER THE NORTHERN PART OF THE GREAT LAKES REGION ON THURSDAY. THIS WILL LEAVE NORTHERN MINNESOTA AND NORTHERN WISCONSIN IN A STRONG NORTHWESTERLY FLOW AT UPPER LEVELS /AROUND 80 KTS AT H5/ AND WITH AROUND 24 HOURS OF COLD /850MB TEMPS AS COLD AS -20 C/ NORTHWEST FLOW AT LOW LEVELS THERE MAY BE SOME MODERATE TO HEAVY LAKE EFFECT SNOWFALL ALONG THE SOUTH SHORE. SKIES WILL BE OVERCAST MOST OF THE TIME...WITH SOME CLEARING ON THURSDAY SOUTH OF HIGHWAY 2. FRIDAY/SATURDAY/SUNDAY...WARMING UP AS HIGH PRESSURE MOVES EAST THROUGH THE MIDWEST LATE THURS/EARLY FRI RESULTING IN SOUTHWEST FLOW AT MID/LOW LEVELS FRI/SAT. 850 MB TEMPS RISE AS WARM AS JUST ABOVE FREEZING OVER THE WEEKEND...AND WITH PARTLY TO MOSTLY SUNNY SKIES SURFACE TEMPS WILL WARM UP TO NEAR FREEZING FRI/SAT AND LIKELY ABOVE FREEZING INTO THE MID/UPPER 30S ON SUNDAY...WHICH IS NEAR TO ABOVE NORMAL FOR MUCH OF THE NORTHLAND. OVER THE WEEKEND AN UPPER LEVEL DISTURBANCE WILL DEEPEN OVER THE SOUTHERN PLAINS AND MOVE NORTH UP THE MISSISSIPPI RIVER VALLEY TO THE CENTRAL GREAT LAKES. MODEL GUIDANCE STILL VARIES WIDELY IN PLACEMENT OF THE UPPER LOW...AND IF IT TRENDS WESTWARD AS THE ECMWF IS HINTING THEN SUNDAY MAY BE COOLER AND CLOUDIER THAN CURRENTLY FORECAST WITH LIGHT SNOW POSSIBLY MIXED WITH RAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1139 AM CST MON NOV 17 2014 MVFR TO VFR CONDITIONS AT TAF SITES ACROSS THE REGION DUE TO LOW CEILINGS AND OFF AND ON SNOW SHOWERS BRIEFLY LOWERING VIS. SNOWFALL WILL TAPER OFF THIS AFTERNOON AND CEILINGS SHOULD RISE TO VFR FOR A FEW HOURS BEFORE DROPPING TO MVFR OVERNIGHT TONIGHT AT MOST SITES...WITH HIGHEST CONFIDENCE IN MVFR CIGS AT BRD AND HYR. WINDS THIS AFTERNOON ARE OUT OF THE NORTHWEST GUSTING TO NEAR 25 KTS...WHICH IS CAUSING BLOWING SNOW AND REDUCED VISIBILITY AT A FEW SPOTS. WINDS WILL WEAKEN THIS EVENING AND BECOME LIGHT OUT OF THE WEST AT 5 TO 10 KTS OVERNIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 2 17 6 20 / 30 0 40 20 INL 0 18 7 19 / 30 20 40 40 BRD 0 16 7 18 / 10 0 40 10 HYR 2 16 3 20 / 30 10 60 30 ASX 7 19 7 23 / 60 30 40 50 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...LAKE EFFECT SNOW WARNING UNTIL NOON CST TUESDAY FOR WIZ003-004. LAKE EFFECT SNOW ADVISORY UNTIL NOON CST TUESDAY FOR WIZ002. LS...GALE WARNING UNTIL 3 AM CST TUESDAY FOR LSZ121-144>148. SMALL CRAFT ADVISORY UNTIL 11 AM CST TUESDAY FOR LSZ140>143. && $$ SHORT TERM...DAP LONG TERM...MOORE AVIATION...MOORE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1122 PM CST Sun Nov 16 2014 .UPDATE: Issued at 923 PM CST Sun Nov 16 2014 Accumulating snow has ended across the area allowing the winter weather advisory to expire at 9 pm. The band of accumulating snow continues just south of the CWA which is being forced by strong frontogenesis that will eventually shift southeast tonight. Some snow may still occur along and south of a Fredericktown to Salem, IL line on the northern periphery of this area of snow before 08Z per the HRRR, but any accumulation is expected to be minor. Temperatures are falling into the teens over northeast Missouri, and decent cold air advection should allow most of the area to fall into the teens before sunrise. Britt && .SHORT TERM: (Through Late Tonight) Issued at 345 PM CST Sun Nov 16 2014 Snow is clearing from the west to east this afternoon, and latest short-range guidance shows that it should continue to push east at a decent clip through early evening. RAP and HRRR have done a very good job with this system (as they did with yesterday`s precipitation) so am following them closely. The surface cold front which currently looks to be along a line from near Pittsfield to near the Lake of the Ozarks, will push slowly eastward tonight. While accumulating snow should end across most of the area by 00-02Z, some flurries could linger along and east of the Mississippi from St. Louis southward until the cold front finally pushes through bringing drier low level air to the area. An additional 1-2 inches of snow with locally higher amounts is still possible until the snow ends...primarily on elevated surfaces. Based on current obs and latest radar trends, will be dropping the advisory west and north of the STL area, while continuing the advisory into the early evening hours over southeast sections of the CWA. Guidance appears to have a reasonable handle on overnight lows. Leading edge of the first round of Arctic air (as defined by single digits dewpoints) currently entering northwest sections of the CWA, and this will be followed by a secondary surge of Arctic air (now working into the mid-Missouri Valley) that will enter the CWA during the predawn hours. In this situation guidance has a tendency to be a bit too cool due to mixing and some clouds, but due to the shear strength of cold air in this situation believe "thinking cold" is the way to go. Carney/Truett .LONG TERM: (Monday through Next Sunday) Issued at 313 PM CST Sun Nov 16 2014 Monday-Wednesday Deep and unseasonably strong UA trof over the eastern half of the CONUS will mean more unseasonably cold November temperatures in our area through midweek. Obviously, temperature specifics are going to be the main forecast problem in the short term, and going forecasts appear to have a fairly good handle on the expected trends. Secondary surge of Arctic air that enters the FA late tonight will be a much colder airmass than any we`ve experienced during this early taste of winter, and there is good agreement in the 12z synoptic runs that 850mb temps of -18 to -20C will be common over the mid-Mississippi Valley by Monday evening. Low level RH progs suggest quite a bit of low level cloudiness overspreading the area on Monday in the wake of the secondary cold front, and this cloud cover combined with the very cold airmass will almost certainly mean highs only in the 20s for most of the CWA. Perhaps the biggest question is Monday night. While airmass is extremely cold for this time of year and there may be snow on the ground in some locations over the southeast half of the CWA, the center of the Arctic high is forecast to drop from the Plains into the Arklatex region. The resultant pressure gradient in our area should mean that westerly winds will persist throughout much of the night, with this mixing keeping low temps from reaching record levels. Normally in this situation would be worried about climo bias causing guidance to be too warm, but due to the aforementioned winds and mixing believe it may have a good handle on Monday night temp trends at this point in time. See climate section for more info on record lows/record low max temps for the next few days/nights. AMS moderation will begin on Tuesday as the center of the Arctic high works its way in the the se U.S., with additional warming on Wednesday due to warm advection ahead of next shortwave. Precipitation threat over the next few days should be limited to a few flurries with the arrival of the cold air and low clouds tomorrow. Thursday-Sunday Another shot of cold air will settle into the region in the wake of Wednesday`s shortwave. However, this next round of cold air will not be nearly as strong as the Arctic airmass that invades the region tomorrow and tomorrow night, and as a result it`s impact on late week temps will not be nearly as dramatic. Temperatures will moderate heading into next weekend as trof axis works east and allows a more zonal flow regime to develop over the nation`s heartland. Resultant low level warm advection/isentropic ascent, combined with an approach of an upper level trof in the southern branch of the westerlies, should mean a chance of precipitation. Last several medium range runs, as well as latest 12z guidance, suggests ams will warm enough that the bulk of this precip will be in liquid form. Truett && .AVIATION: (For the 06z TAFs through 06z Monday Night) Issued at 1121 PM CST Sun Nov 16 2014 Vfr conditions have returned to the taf sites, though some lingering mvfr cigs around KCPS through 07z. Otherwise, northwest winds to pickup by mid morning with gusts to near 25kts at times. Will see sc develop on back side of system, so kept tempo mention of mvfr cigs through the afternoon hours before scattering out towards sunset. Winds will diminish towards sunset as well. Specifics for KSTL: Vfr conditions have returned to the metro area, though some lingering mvfr cigs around KCPS through 07z. Otherwise, northwest winds to pickup by 16z Monday with gusts to near 25kts at times. Will see sc develop on back side of system, so kept tempo mention of mvfr cigs through the afternoon hours before scattering out towards sunset. Winds will diminish towards sunset as well. Byrd && .CLIMATE: The following are record low maximums and record low minimums for each of the next 3 days, which corresponds to the expected length of the current cold spell and record snowfall for St. Louis and Columbia for Sunday and Monday. Date: 11/16 11/17 11/18 St. Louis Low High: 29/1997 17/1880 25/1880 Low: 13/1959 6/1959 14/1932 Snowfall: 0.1/1997 1.0/1951 Columbia Low High: 30/1932 23/1959 27/1903 Low: 8/1959 4/1959 8/1891 Snowfall: 4.8/1932 0.1/1989 Quincy Low High: 28/1997 19/1959 24/1903 Low: 4/1959 3/1959 7/1903 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
908 PM EST TUE NOV 18 2014 .SYNOPSIS... ARCTIC AIR HAS INVADED THE REGION. OTHER THAN OCCASIONAL LAKE EFFECT SNOW SHOWERS AND FLURRIES IN CENTRAL NEW YORK...COLD YET MAINLY DRY CONDITIONS CAN BE EXPECTED. WIND CHILLS AT TIMES WILL DIP INTO THE SINGLE DIGITS OR BELOW ZERO THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 910 PM UPDATE... THE BIG CHANGE THIS PERIOD WAS TO PULL THE POPS OUT OF THE CENTRAL SOUTHERN TIER. BAND IS WELL NORTHWEST OF STEUBEN CTY AT THIS TIME, AND IF ANYTHING, THE BAND SHOULD TREND NORTHWARD. ONEIDA COUNTY IS A TOUGHER CALL. FOR NOW, HAVE DELAYED THE EDGE OF THE BAND TOUCHING NORTHERN ONEIDA. NOT CONVINCED POPS DON`T NEED TO BE LOWERED HERE IS WELL, BUT WILL CONTINUE TO MONITOR AND ASSESS. 120 PM UPDATE... LK SNOWS WL CONTINUE PUMMEL AREAS NORTH AND WEST OF CWA TONIGHT. LK SNOWS WL CONTINUE INTO THE EVNG HRS IN THE SAME LOCALES. SFC TROF CURRENTLY LOCATED ACRS LK HURON AND ACRS NRN LOWER MI WL SWING THRU AFT MIDNIGHT AND SHIFT SNOWBAND SOUTH INTO EXTREME NRN ONEIDA CNTY. HWVR, HOW FAR SOUTH THIS BAND GETS IS THE QUESTION. ALL MODELS ARE DOING A GOOD JOB OF HANDLING THE CURRENT SNOWBANDS QUITE WELL, ENUF TO LEAD TO INCREASED CONFIDENCE ON HANDLING OF SNOW FCST FOR THE OVRNGT. HIRES NMM, ARW, RUC AND HRRR AND TO A LESSER EXTENT THE 12Z NAM SHOW INTENSE PORTION OF BAND DROPPING INTO EXTRM NERN ONEIDA CNTY TONIGHT AFT 05Z. THIS BAND LOOKS TO HOLD PRETTY STEADY-STATE THRU 12Z, POSSIBLY WITH A SLIGHT WAFFLE TO THE SOUTH DRG THE OVRNGT. THUS, FEEL CONFIDENT ENUF TO RAISE A LK EFFECT ADVISORY FOR NRN ONEIDA CNTY FM 03Z TO 14Z WED WITH STORM TOTAL ACCUMS IN A 12-HR PD RANGING FM 4-7 INCHES. IF THIS BAND OVERPERFORMS THAN CUD EASILY SEE WARNING CRITERIA SNOWS FOR THE BOONVILLE AND WOODGATE AREAS BUT CONFIDENCE IS LOW ON THAT ACTUALLY OCCURRING. OVRNGT LOWS WL DIP INTO THE LOWER TEENS, ESPECIALLY UNDER CLR SKIES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... 240 PM UPDATE... UPR LVL WV CURRENTLY DROPPING THRU NRN PRAIRIE PROVINCES WL APPCH CWA DURING THE DAY TOMORROW. THIS WL SERVE TO SHIFT BACK SWRLY FLOW TWD THE SOUTH AND ALLOW LK SNOWS TO BCM DISRUPTED AND SHIFT NORTH BY AFTN. CLDS WL BE ON THE INCRS FM WEST TO EAST DRG THE MRNG HRS. WL LKLY JUST SEE SLGT CHC FOR SNOW SHOWERS AND A FEW FLURRIES SKIRTING THRU CNTRL NY AS WV SHEARS OUT INTO CANADA. SYSTEM WL GIVE WRN SXNS OF CWA JUST A GLANCING BLOW TOMORROW NGT WITH JUST MINOR ACCUMS OF SNOW. AS THE TROF LIFTS NORTH AND LOW-LVL FLOW VEERS ARND TO THE SW AGAIN EXPECT LK SNOWS TO GET GOING ONCE AGAIN THUR MRNG THRU THE END OF THE SHORT TERM. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... 115 PM EST UPDATE... SNOW SHOWERS DURING THE DAY ON FRIDAY WILL START TO SLOWLY END FRIDAY NIGHT AS THE UPPER LEVEL TROUGH AXIS WILL SHIFT FAR ENOUGH EAST TO NOT IMPACT THE CWA. THE EASTWARD SHIFT IN THE AXIS WILL ALLOW ANTI-CYCLONIC FLOW ALOFT AND SFC RIDGING TO BUILD OVER THE REGION. THIS RIDGING PATTERN WILL REMAIN OVER THE REGION JUST BRIEFLY BUT LONG ENOUGH TO ALLOW MUCH OF THE DAY ON SATURDAY TO REMAIN DRY. GUIDANCE IS ON PRETTY GOOD AGREEMENT ON THE NEXT STORM SYSTEM THAT WILL MOVE INTO OUR AREA. THAT IS THE CHANCE FOR RAIN SHOWERS WILL RETURN TO PORTIONS OF CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA. A SFC LOW WILL DEVELOP OVER THE SOUTHERN PLAINS THEN PROPAGATE NORTHEAST TOWARDS THE MIDWEST SUNDAY. WHAT THAT MEANS FOR OUR CWA IS THAT A CHANCE FOR SHOWERS WILL EXIST STARTING SUNDAY MORNING AND PREVAIL THROUGH EARLY NEXT WEEK. A WARM FRONT WILL PASS THROUGH THE REGION EARLY SUNDAY MORNING RESULTING IN STRONG WAA. THIS WILL BE OUR FIRST FEATURE THAT MAY BRING THE CHANCE FOR SHOWERS. SHORTLY AFTER AN OCCLUDED FRONT WILL PASS THROUGH BRINGING ADDITIONAL CHANCES FOR SHOWERS. TEMPS WITH THIS SYSTEM WILL BE FAIRLY WARM FOR THIS TIME OF THE YEAR. TEMPERATURES WILL MANAGE TO REACH THE LOW TO MID 50S SUNDAY AND MONDAY BEFORE THE COOLER AIR MOVES IN ON TUESDAY. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... VFR CONDS CONT AND ARE XPCTD THRU THE TAF PD. HEAVY LE BANDS SHD CONT WELL NORTH OF RME AND SYR...WITH ONLY OCNL ROGUE FLURRIES MVG THRU BRINGING BRIEF LWRG OF CIGS AND VSBYS. GUSTY WINDS WILL DIMINISH THIS EVENING AS THE LL STABILIZE A BIT...AND BECOME MORE SWLY ON WED AHD OF A SHRT WV. PCPN FROM WV SHD BEGIN AFTER THE END OF THE TAF PD. OUTLOOK... WED NGT-THU-FRI...RESTRICTIONS IN LAKE EFFECT -SHSN...ESP RME AND SYR. SAT...VFR. SUN... RESTRICTIONS POSSIBLE IN RAIN/SNOW SHOWERS. && .CLIMATE... 345 AM TUESDAY UPDATE... TODAY RECORD COLD NOT IN JEOPARDY SINCE AT MIDNIGHT SEVERAL DEGREES ABOVE THE DAILY RECORD LOWEST MAXIMUM TEMPERATURES. TOMORROW 11/19 FORECAST WILL BE WITHIN 2 DEGREES OF THE RECORD LOW TEMPERATURES FOR THE DAY. AT AVOCA (SCRANTON/WB) RECORD DAILY LOW 14 IN 1924 LOWEST HIGH TEMP 28 IN 1951 AND LOWEST AVERAGE TEMP 24.5 IN 1936 AT BINGHAMTON RECORD DAILY LOW 13 IN 1986 LOWEST HIGH TEMP 23 IN 1951 AND LOWEST AVERAGE TEMP 20.5 IN 1951 AT SYRACUSE RECORD DAILY LOW 14 IN 1962 LOWEST HIGH TEMP 27 IN 1951 AND LOWEST AVERAGE TEMP 21.5 IN 1986 && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 9 AM EST WEDNESDAY FOR NYZ009. && $$ SYNOPSIS...PVF NEAR TERM...DJP/PVF SHORT TERM...PVF LONG TERM...KAH AVIATION...DGM/KAH CLIMATE...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
643 PM EST TUE NOV 18 2014 .SYNOPSIS... ARCTIC AIR HAS INVADED THE REGION. OTHER THAN OCCASIONAL LAKE EFFECT SNOW SHOWERS AND FLURRIES IN CENTRAL NEW YORK...COLD YET MAINLY DRY CONDITIONS CAN BE EXPECTED. WIND CHILLS AT TIMES WILL DIP INTO THE SINGLE DIGITS OR BELOW ZERO THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 120 PM UPDATE... LK SNOWS WL CONTINUE PUMMEL AREAS NORTH AND WEST OF CWA TONIGHT. LK SNOWS WL CONTINUE INTO THE EVNG HRS IN THE SAME LOCALES. SFC TROF CURRENTLY LOCATED ACRS LK HURON AND ACRS NRN LOWER MI WL SWING THRU AFT MIDNIGHT AND SHIFT SNOWBAND SOUTH INTO EXTREME NRN ONEIDA CNTY. HWVR, HOW FAR SOUTH THIS BAND GETS IS THE QUESTION. ALL MODELS ARE DOING A GOOD JOB OF HANDLING THE CURRENT SNOWBANDS QUITE WELL, ENUF TO LEAD TO INCREASED CONFIDENCE ON HANDLING OF SNOW FCST FOR THE OVRNGT. HIRES NMM, ARW, RUC AND HRRR AND TO A LESSER EXTENT THE 12Z NAM SHOW INTENSE PORTION OF BAND DROPPING INTO EXTRM NERN ONEIDA CNTY TONIGHT AFT 05Z. THIS BAND LOOKS TO HOLD PRETTY STEADY-STATE THRU 12Z, POSSIBLY WITH A SLIGHT WAFFLE TO THE SOUTH DRG THE OVRNGT. THUS, FEEL CONFIDENT ENUF TO RAISE A LK EFFECT ADVISORY FOR NRN ONEIDA CNTY FM 03Z TO 14Z WED WITH STORM TOTAL ACCUMS IN A 12-HR PD RANGING FM 4-7 INCHES. IF THIS BAND OVERPERFORMS THAN CUD EASILY SEE WARNING CRITERIA SNOWS FOR THE BOONVILLE AND WOODGATE AREAS BUT CONFIDENCE IS LOW ON THAT ACTUALLY OCCURRING. OVRNGT LOWS WL DIP INTO THE LOWER TEENS, ESPECIALLY UNDER CLR SKIES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... 240 PM UPDATE... UPR LVL WV CURRENTLY DROPPING THRU NRN PRAIRIE PROVINCES WL APPCH CWA DURING THE DAY TOMORROW. THIS WL SERVE TO SHIFT BACK SWRLY FLOW TWD THE SOUTH AND ALLOW LK SNOWS TO BCM DISRUPTED AND SHIFT NORTH BY AFTN. CLDS WL BE ON THE INCRS FM WEST TO EAST DRG THE MRNG HRS. WL LKLY JUST SEE SLGT CHC FOR SNOW SHOWERS AND A FEW FLURRIES SKIRTING THRU CNTRL NY AS WV SHEARS OUT INTO CANADA. SYSTEM WL GIVE WRN SXNS OF CWA JUST A GLANCING BLOW TOMORROW NGT WITH JUST MINOR ACCUMS OF SNOW. AS THE TROF LIFTS NORTH AND LOW-LVL FLOW VEERS ARND TO THE SW AGAIN EXPECT LK SNOWS TO GET GOING ONCE AGAIN THUR MRNG THRU THE END OF THE SHORT TERM. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... 115 PM EST UPDATE... SNOW SHOWERS DURING THE DAY ON FRIDAY WILL START TO SLOWLY END FRIDAY NIGHT AS THE UPPER LEVEL TROUGH AXIS WILL SHIFT FAR ENOUGH EAST TO NOT IMPACT THE CWA. THE EASTWARD SHIFT IN THE AXIS WILL ALLOW ANTI-CYCLONIC FLOW ALOFT AND SFC RIDGING TO BUILD OVER THE REGION. THIS RIDGING PATTERN WILL REMAIN OVER THE REGION JUST BRIEFLY BUT LONG ENOUGH TO ALLOW MUCH OF THE DAY ON SATURDAY TO REMAIN DRY. GUIDANCE IS ON PRETTY GOOD AGREEMENT ON THE NEXT STORM SYSTEM THAT WILL MOVE INTO OUR AREA. THAT IS THE CHANCE FOR RAIN SHOWERS WILL RETURN TO PORTIONS OF CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA. A SFC LOW WILL DEVELOP OVER THE SOUTHERN PLAINS THEN PROPAGATE NORTHEAST TOWARDS THE MIDWEST SUNDAY. WHAT THAT MEANS FOR OUR CWA IS THAT A CHANCE FOR SHOWERS WILL EXIST STARTING SUNDAY MORNING AND PREVAIL THROUGH EARLY NEXT WEEK. A WARM FRONT WILL PASS THROUGH THE REGION EARLY SUNDAY MORNING RESULTING IN STRONG WAA. THIS WILL BE OUR FIRST FEATURE THAT MAY BRING THE CHANCE FOR SHOWERS. SHORTLY AFTER AN OCCLUDED FRONT WILL PASS THROUGH BRINGING ADDITIONAL CHANCES FOR SHOWERS. TEMPS WITH THIS SYSTEM WILL BE FAIRLY WARM FOR THIS TIME OF THE YEAR. TEMPERATURES WILL MANAGE TO REACH THE LOW TO MID 50S SUNDAY AND MONDAY BEFORE THE COOLER AIR MOVES IN ON TUESDAY. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... VFR CONDS CONT AND ARE XPCTD THRU THE TAF PD. HEAVY LE BANDS SHD CONT WELL NORTH OF RME AND SYR...WITH ONLY OCNL ROGUE FLURRIES MVG THRU BRINGING BRIEF LWRG OF CIGS AND VSBYS. GUSTY WINDS WILL DIMINISH THIS EVENING AS THE LL STABILIZE A BIT...AND BECOME MORE SWLY ON WED AHD OF A SHRT WV. PCPN FROM WV SHD BEGIN AFTER THE END OF THE TAF PD. OUTLOOK... WED NGT-THU-FRI...RESTRICTIONS IN LAKE EFFECT -SHSN...ESP RME AND SYR. SAT...VFR. SUN... RESTRICTIONS POSSIBLE IN RAIN/SNOW SHOWERS. && .CLIMATE... 345 AM TUESDAY UPDATE... TODAY RECORD COLD NOT IN JEOPARDY SINCE AT MIDNIGHT SEVERAL DEGREES ABOVE THE DAILY RECORD LOWEST MAXIMUM TEMPERATURES. TOMORROW 11/19 FORECAST WILL BE WITHIN 2 DEGREES OF THE RECORD LOW TEMPERATURES FOR THE DAY. AT AVOCA (SCRANTON/WB) RECORD DAILY LOW 14 IN 1924 LOWEST HIGH TEMP 28 IN 1951 AND LOWEST AVERAGE TEMP 24.5 IN 1936 AT BINGHAMTON RECORD DAILY LOW 13 IN 1986 LOWEST HIGH TEMP 23 IN 1951 AND LOWEST AVERAGE TEMP 20.5 IN 1951 AT SYRACUSE RECORD DAILY LOW 14 IN 1962 LOWEST HIGH TEMP 27 IN 1951 AND LOWEST AVERAGE TEMP 21.5 IN 1986 && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST WEDNESDAY FOR NYZ009. && $$ SYNOPSIS...PVF NEAR TERM...PVF SHORT TERM...PVF LONG TERM...KAH AVIATION...DGM/KAH CLIMATE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
958 AM EST MON NOV 17 2014 .SYNOPSIS... A COMPLEX LOW PRESSURE SYSTEM AND ASSOCIATED FRONTS WILL MOVE ACROSS THE NORTH COUNTRY TODAY. PRECIPITATION WILL START OUT AS SNOW...CHANGE TO A MIX...THEN RAIN BEFORE ENDING. A SIGNIFICANT LAKE EFFECT SNOW EVENT IS EXPECTED FOR THE NORTHERN ADIRONDACKS AND THE SOUTHERN SAINT LAWRENCE VALLEY EARLY THIS WEEK. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 958 AM EST MONDAY...MINOR UPDATES HERE AT MID MORNING. RADAR SHOWING LOTS OF PRECIPITATION ACROSS THE REGION, THOUGH THERE IS A SLIGHT LULL ACROSS MUCH OF NORTHERN VERMONT. SURFACE TEMPERATURES IN MOST LOWER ELEVATION AREAS ARE IN THE 32-36F RANGE, SO ROADS SEEM TO BE IN DECENT SHAPE. STILL 22-24F UP ON MANSFIELD AND WHITEFACE, SO THE NOSE OF WARMER AIR ALOFT IS STILL NOT THAT FAR NORTH, SO SNOW IS STILL THE MAIN P-TYPE ABOVE ROUGHLY 800FT ELEVATION. BELOW THAT, IT`S RAIN/SNOW OR ALREADY TURNED OVER TO RAIN. CAN`T RULE OUT A TOUCH OF FREEZING DRIZZLE EITHER, ESPECIALLY IN SOUTHERN SECTIONS OF VERMONT. ASOS IN SPRINGFIELD HAS RECORDED 0.02" OF ICING. FORECAST ISSUE IS TRYING TO TIME THE VARIOUS P-TYPE CHANGEOVER TIMES. HAVE RELIED HEAVILY ON THE 13Z RAP FOR GUIDANCE FOR TEMPERATURES ALOFT. 12Z ALBANY SOUNDING SHOWED THE ABOVE-FREEZING AIR BETWEEN 800-700MB (5000-8000FT) AND THIS WAS PUSHING NORTHWARD. BASED UPON THE RAP, THAT WARMER AIR SHOULD REACH THE CANADIAN BORDER ABOUT 20Z. BY THAT POINT, PRETTY MUCH ALL OF US WILL BE SEEING LIGHT RAIN, THOUGH THE LOWER ELEVATIONS SUCH AS THE CHAMPLAIN VALLEY SHOULD BE ALL RAIN BY 16Z (11AM). LOOKING UPSTREAM, WE STILL HAVE SOME PRECIPITATION TO MOVE THROUGH, THOUGH NOTHING LOOKS TOO TERRIBLY HEAVY. PERHAPS 0.04"/HOUR AT BEST. ADD THAT UP OVER THE AFTERNOON, AND WE ARE LOOKING AT PERHAPS 1/4" OF LIQUID EQUIVALENT. COMBINE THAT WITH WHEN IT WILL ACTUALLY BE IN THE FORM OF SNOW, WE AREN`T LOOKING AT MUCH ACCUMULATION - ANOTHER 1/2" IN THE HIGHER ELEVATIONS. I JUST WANT TO SEE HOW THINGS PLAY OUT OVER THE NEXT FEW HOURS, AND ASSUMING MOTHER NATURE FOLLOWS OUR EXPECTATIONS, I WOULD THINK WE SHOULD BE ABLE TO TAKE DOWN THE WINTER WEATHER ADVISORY FOR THE `DACKS EARLY (JUST LEAVING THE LAKE EFFECT WARNING IN PLACE). && .SHORT TERM /7 PM THIS EVENING THROUGH WEDNESDAY/... AS OF 400 AM EST MONDAY...THIS EVENING COLD AIR STREAMS BACK INTO THE AREA FROM THE WEST AND ANY PRECIPITATION REMAINING WILL CHANGE TO SNOW SHOWERS FROM WEST TO EAST ACROSS OUR FORECAST AREA. AS COLD AIR MOVES IN...STRONG FLOW ACROSS MILD LAKE ONTARIO WILL CREATE PERSISTENT BAND OF LAKE EFFECT SNOW IN THE SOUTHERN SAINT LAWRENCE VALLEY AND NORTHERN ADIRONDACKS. HAVE UPGRADED OUR LAKE EFFECT SNOW WATCH TO A WARNING...ALSO MOVED UP THE START TIME TO 00Z TUESDAY...ENDING 12Z WEDNESDAY. STRONG AND UNIFORM SSW FLOW OF 40+ KNOTS SHOULD SUSTAIN SIGNIFICANT BAND OF LAKE EFFECT. THERE IS ALSO PLENTY OF LOW LEVEL INSTABILITY TO SUSTAIN THIS. ANALOGS INDICATE THAT THIS COULD BE A MAJOR LAKE EFFECT SNOW EVENT DOWNWIND OF LAKE ONTARIO. A SOUTHWEST FLOW SINGLE BAND LAKE EFFECT SNOW EVENT IS EXPECTED. UPPER TROF CROSSING OUR AREA DURING THIS TIME INFLUENCES FLOW AND SET UP OF THE SNOW BAND. SURFACE WINDS WILL ALSO BE STRONG WITH INCREASED PRESSURE GRADIENT...MAKING CONDITIONS EVEN WORSE WHERE THE HEAVY SNOW IS FALLING. THUNDER AND LIGHTNING WILL BE POSSIBLE WITH LAKE EFFECT SNOW DUE TO HIGH CAPE...AND HEAVY RAINFALL RATES ARE POSSIBLE WITH THE WELL ALIGNED FLOW AND TEMPERATURE CONTRAST. LAKE EFFECT SNOW WILL TEMPORARILY SHUT DOWN WEDNESDAY AFTERNOON WITH THE UPPER TROF PASSING AND FLOW BECOMING MORE SOUTHERLY. ADDITIONAL LAKE EFFECT SNOW IS EXPECTED LATER IN THE WEEK. TEMPERATURES WILL BE COLD FROM TONIGHT THROUGH WEDNESDAY...ABOUT 10 TO 15 DEGREES BELOW SEASONAL NORMALS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 320 AM EST SUNDAY...THIS MORNING`S GLOBAL MODELS REMAIN IN GOOD AGREEMENT SHOWING PRIMARY SURGE OF CP AIR TO AFFECT THE NORTHEAST DURING THE THU-SAT TIME FRAME WITH DAILY TEMPERATURES AVERAGING SOME 12 TO 18 DEGREES BELOW LATE AUTUMN NORMS. THEREAFTER INCREASING SIGNS THAT A SIGNIFICANT WARM-UP WILL SPREAD EAST ACROSS THE CENTRAL/ERN U.S. BY LATER NEXT WEEKEND INTO EARLY NEXT WEEK AS STRONG BELT OF WESTERLIES UNDERCUT THE DEPARTING ARCTIC AIRMASS. DETAILS...IN THE LATE WEEK TIME FRAME WILL STILL BE DEALING WITH COLD TEMPERATURES AND PERSISTENT LAKE EFFECT SNOWS DOWNWIND OF LAKE ONTARIO. FINAL BUT FAIRLY SHARP ARCTIC SHORTWAVE TROUGH AND ASSOCIATED FRONTAL PASSAGE WILL CROSS THE AREA THURSDAY INTO THURSDAY NIGHT WITH LAKE SNOWS SHIFTING SLOWLY N-S OVER TIME WITH ADDITIONAL...POTENTIALLY SIGNIFICANT ACCUMULATIONS ACROSS THE SNOWBELTS THU/EARLY FRI. ELSEWHERE SCT FLURRIES/SHSN STILL A GOOD BET...ESP IN THE NRN GREENS ON THU WHERE SOME ADDITIONAL MINOR ACCUMULATIONS WILL ALSO BE POSSIBLE. HIGHS GENERALLY RUNNING FROM 25 TO 35 ON THURSDAY...THEN COLDER IN THE 20S BEHIND THE FRONT FRI. LOWS MAINLY IN THE TEENS/20S THU...THEN TEENS BY FRI. BY SATURDAY ARCTIC HIGH PRESSURE SETTLES ACROSS THE EAST COAST AS LAKE SNOWS COME TO AND END AND SKIES TREND CLR/PTLY CLOUDY. STILL UNSEASONABLY CHILLY WITH MORNING LOWS SINGLE DIGITS/TEENS AND HIGHS REMAINING IN THE 20S DESPITE THE INCREASING SUN. THEREAFTER THERE IS INCREASING CONFIDENCE THAT A MAJOR PATTERN CHANGE WILL OCCUR ACROSS THE NORTHEAST BY LATER NEXT WEEKEND AND BEYOND AS ARCTIC AIR LIFTS OUT TO THE NORTHEAST AND IS REPLACED BY INCREASINGLY MILD WEST/SOUTHWEST CONUS FLOW. THUS HAVE ADVERTISED TEMPERATURES CLIMBING BACK ABOVE THE FREEZING MARK (30S) IN ALL AREAS BY NEXT SUNDAY WITH EVEN MILDER AIR ON THE HORIZON FOR EARLY NEXT WEEK AS CHANCES FOR RAIN SLOWLY INCREASE. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... THROUGH 12Z TUESDAY...MIVFR/IFR CONDITIONS IN SNOW THIS MORNING AS LOW PRESSURE LIFTS ACROSS THE AREA WITH WIDESPREAD PCPN. PCPN CHANGING TO A MIX THEN PLAIN RAIN SOUTH TO NORTH FOR KPBG AND VT TERMINALS FROM 14-18Z. SNOW HANGS ON LONGER IN THE COLDER AIR AT KMSS/KSLK AND MAY REMAIN ALL SNOW AT KMSS DEPENDING ON DEGREE OF WARMER AIR ALOFT. PCPN TAPERS OFF BY 00Z LEAVING GENERALLY BKN/OVC MVFR/VFR CIGS. EXCEPTION AT KSLK WHERE PERSISTENT MVFR/IFR SHSN WILL CONTINUE. WINDS GENERALLY SOUTH/SOUTHEASTERLY 5 TO 10 KTS TODAY (NORTHEASTERLY AT KMSS)...VEERING TO SOUTHWESTERLY 8 TO 15 KTS AND BECOMING GUSTY AFTER 00Z AS SFC FRONT CLEARS EAST. OUTLOOK 12Z TUESDAY THROUGH FRIDAY... 12Z TUESDAY ONWARD...SCT/BKN MAINLY VFR WITH INTERMITTENT SNOW SHOWERS/FLURRIES AND BRIEF PERIODS OF MVFR/IFR POSSIBLE. EXCEPTION AT KSLK WHERE INFLUENCE OF LAKE ONTARIO LAKE EFFECT SNOWS WILL COME INTO PLAY WITH MVFR AND OCCNL IFR SHSN MORE PREVALENT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...LAKE EFFECT SNOW WARNING FROM 7 PM THIS EVENING TO 7 AM EST WEDNESDAY FOR NYZ029-030-087. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ029>031-034. && $$ SYNOPSIS...NEILES NEAR TERM...NASH SHORT TERM...NEILES/SISSON LONG TERM...JMG AVIATION...JMG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1204 PM CST MON NOV 17 2014 .UPDATE... ISSUED AT 1204 AM CST MON NOV 17 2014 ISOLATED FLURRIES AND LIGHT SNOW SHOWERS HAVE DEVELOPED ACROSS WESTERN AND CENTRAL NORTH DAKOTA. ADDED ISOLATED FLURRIES TO THE AFTERNOON FORECAST AS A RESULT. THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 837 AM CST MON NOV 17 2014 NO MAJOR CHANGES WERE MADE TO THE ONGOING FORECAST. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS TO COME MORE IN LINE WITH THE CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 644 AM CST MON NOV 17 2014 NO SIGNIFICANT CHANGES REQUIRED WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC WITH A FRIGID DAY EXPECTED AREA WIDE IN THE WAKE OF THE SUNDAY REINFORCING COLD FRONT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CST MON NOV 17 2014 HUDSON BAY UPPER LOW WITH SUCCESSIVE SHORTWAVE TROUGHS ROTATING AROUND HAS CARVED OUT A SIGNIFICANT UPPER TROUGH EXTENDING SOUTH INTO THE MIDWEST AND SOUTHERN PLAINS PER LATEST WATER VAPOR IMAGERY. NORTHERLY FLOW INTO NORTH DAKOTA WITH ANOTHER MINOR SHORTWAVE NOW LOCATED JUST WEST OF LAKE WINNIPEG IS FORECAST TO REACH INTO THE BISMARCK VICINITY BY 18Z TODAY. THE LATEST FOG/STRATUS LOOP SHOWS CLOUDS AND FLURRIES OVER THE SOUTHWEST...WHICH EXTENDS ACROSS MOST OF EASTERN MONTANA. FARTHER UPSTREAM CLOSER TO THE LOCATION OF THE INCOMING SHORTWAVE...QUITE A BIT OF CLOUDS PUSHING SOUTH. THE LATEST HRRR REINFORCES CLOUDS ESPECIALLY IN THE WEST...BUT THINK THE CENTRAL WILL ALSO CLOUD UP DURING THE LATE MORNING AND EARLY AFTERNOON. THE HIGH RESOLUTION ARW AND NMM MODELS CONTINUE WITH THE FLURRIES WEST THROUGH 18Z TODAY AND HAVE FOLLOWED THIS AS THEY ARE VERIFYING THE BEST EARLY THIS MORNING WITH THE CURRENT ACTIVITY. WARM AIR ADVECTION COMMENCES MONDAY NIGHT WITH A PUSH OF H7-H5 MOISTURE. THIS WILL PROGRESS FROM WEST TO EAST OVERNIGHT RESULTING IN PARTLY CLOUDY CONDITIONS. HIGHS TODAY WILL RANGE FROM 10F TO 15F WITH OVERNIGHT LOWS BETWEEN 3 BELOW ZERO TO 3 ABOVE. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 334 AM CST MON NOV 17 2014 A POTENTIAL MODERATION IN TEMPERATURES LATE THIS WEEK HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC SUITE IS IN AGREEMENT ON THE ANOMALOUS HIGH AMPLITUDE UPPER LEVEL PATTERN ACROSS NORTH AMERICA BREAKING DOWN TO A NEAR ZONAL PATTERN BY NEXT WEEKEND IN A BROAD VERY LOW AMPLITUDE TROUGH. THIS WOULD SIGNAL A RECOVERY FROM THE ARCTIC TEMPERATURES TO STILL BELOW NORMAL...YET MORE TOLERABLE HIGHS NEAR FREEZING FRIDAY INTO THE WEEKEND. THE EXTENDED FORECAST LOOKS TO BE LARGELY PRECIPITATION FREE...WITH SPLIT FLOW DEVELOPING AND THE LACK OF MOISTURE RECOVERY FROM THE ARCTIC AIRMASS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1204 AM CST MON NOV 17 2014 VFR/TEMPO MVFR CONDITIONS IN CIGS AND FLURRIES WILL CONTINUE OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. CONDITIONS SHOULD IMPROVE TO VFR OVERNIGHT THROUGH TUESDAY MORNING. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...KS LONG TERM...AYD AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
837 AM CST MON NOV 17 2014 .UPDATE... ISSUED AT 837 AM CST MON NOV 17 2014 NO MAJOR CHANGES WERE MADE TO THE ONGOING FORECAST. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS TO COME MORE IN LINE WITH THE CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 644 AM CST MON NOV 17 2014 NO SIGNIFICANT CHANGES REQUIRED WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC WITH A FRIGID DAY EXPECTED AREA WIDE IN THE WAKE OF THE SUNDAY REINFORCING COLD FRONT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CST MON NOV 17 2014 HUDSON BAY UPPER LOW WITH SUCCESSIVE SHORTWAVE TROUGHS ROTATING AROUND HAS CARVED OUT A SIGNIFICANT UPPER TROUGH EXTENDING SOUTH INTO THE MIDWEST AND SOUTHERN PLAINS PER LATEST WATER VAPOR IMAGERY. NORTHERLY FLOW INTO NORTH DAKOTA WITH ANOTHER MINOR SHORTWAVE NOW LOCATED JUST WEST OF LAKE WINNIPEG IS FORECAST TO REACH INTO THE BISMARCK VICINITY BY 18Z TODAY. THE LATEST FOG/STRATUS LOOP SHOWS CLOUDS AND FLURRIES OVER THE SOUTHWEST...WHICH EXTENDS ACROSS MOST OF EASTERN MONTANA. FARTHER UPSTREAM CLOSER TO THE LOCATION OF THE INCOMING SHORTWAVE...QUITE A BIT OF CLOUDS PUSHING SOUTH. THE LATEST HRRR REINFORCES CLOUDS ESPECIALLY IN THE WEST...BUT THINK THE CENTRAL WILL ALSO CLOUD UP DURING THE LATE MORNING AND EARLY AFTERNOON. THE HIGH RESOLUTION ARW AND NMM MODELS CONTINUE WITH THE FLURRIES WEST THROUGH 18Z TODAY AND HAVE FOLLOWED THIS AS THEY ARE VERIFYING THE BEST EARLY THIS MORNING WITH THE CURRENT ACTIVITY. WARM AIR ADVECTION COMMENCES MONDAY NIGHT WITH A PUSH OF H7-H5 MOISTURE. THIS WILL PROGRESS FROM WEST TO EAST OVERNIGHT RESULTING IN PARTLY CLOUDY CONDITIONS. HIGHS TODAY WILL RANGE FROM 10F TO 15F WITH OVERNIGHT LOWS BETWEEN 3 BELOW ZERO TO 3 ABOVE. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 334 AM CST MON NOV 17 2014 A POTENTIAL MODERATION IN TEMPERATURES LATE THIS WEEK HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC SUITE IS IN AGREEMENT ON THE ANOMALOUS HIGH AMPLITUDE UPPER LEVEL PATTERN ACROSS NORTH AMERICA BREAKING DOWN TO A NEAR ZONAL PATTERN BY NEXT WEEKEND IN A BROAD VERY LOW AMPLITUDE TROUGH. THIS WOULD SIGNAL A RECOVERY FROM THE ARCTIC TEMPERATURES TO STILL BELOW NORMAL...YET MORE TOLERABLE HIGHS NEAR FREEZING FRIDAY INTO THE WEEKEND. THE EXTENDED FORECAST LOOKS TO BE LARGELY PRECIPITATION FREE...WITH SPLIT FLOW DEVELOPING AND THE LACK OF MOISTURE RECOVERY FROM THE ARCTIC AIRMASS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 645 AM CST MON NOV 17 2014 CIGS WILL TRANSITION FROM LOW VFR AT KISN/KDIK TO MVFR BETWEEN 15Z-16Z...WITH IMPROVING CONDITIONS TO VFR BY 00Z TUESDAY. ISOLATED FLURRIES ARE POSSIBLE AT KDIK AND KISN THIS MORNING WITH MINIMAL VISIBILITY IMPACTS. LOW VFR CIGS EXPECTED AT KMOT/KBIS/KJMS THROUGH THE PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...KS LONG TERM...AYD AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
645 AM CST MON NOV 17 2014 .UPDATE... ISSUED AT 644 AM CST MON NOV 17 2014 NO SIGNIFICANT CHANGES REQUIRED WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC WITH A FRIGID DAY EXPECTED AREA WIDE IN THE WAKE OF THE SUNDAY REINFORCING COLD FRONT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CST MON NOV 17 2014 HUDSON BAY UPPER LOW WITH SUCCESSIVE SHORTWAVE TROUGHS ROTATING AROUND HAS CARVED OUT A SIGNIFICANT UPPER TROUGH EXTENDING SOUTH INTO THE MIDWEST AND SOUTHERN PLAINS PER LATEST WATER VAPOR IMAGERY. NORTHERLY FLOW INTO NORTH DAKOTA WITH ANOTHER MINOR SHORTWAVE NOW LOCATED JUST WEST OF LAKE WINNIPEG IS FORECAST TO REACH INTO THE BISMARCK VICINITY BY 18Z TODAY. THE LATEST FOG/STRATUS LOOP SHOWS CLOUDS AND FLURRIES OVER THE SOUTHWEST...WHICH EXTENDS ACROSS MOST OF EASTERN MONTANA. FARTHER UPSTREAM CLOSER TO THE LOCATION OF THE INCOMING SHORTWAVE...QUITE A BIT OF CLOUDS PUSHING SOUTH. THE LATEST HRRR REINFORCES CLOUDS ESPECIALLY IN THE WEST...BUT THINK THE CENTRAL WILL ALSO CLOUD UP DURING THE LATE MORNING AND EARLY AFTERNOON. THE HIGH RESOLUTION ARW AND NMM MODELS CONTINUE WITH THE FLURRIES WEST THROUGH 18Z TODAY AND HAVE FOLLOWED THIS AS THEY ARE VERIFYING THE BEST EARLY THIS MORNING WITH THE CURRENT ACTIVITY. WARM AIR ADVECTION COMMENCES MONDAY NIGHT WITH A PUSH OF H7-H5 MOISTURE. THIS WILL PROGRESS FROM WEST TO EAST OVERNIGHT RESULTING IN PARTLY CLOUDY CONDITIONS. HIGHS TODAY WILL RANGE FROM 10F TO 15F WITH OVERNIGHT LOWS BETWEEN 3 BELOW ZERO TO 3 ABOVE. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 334 AM CST MON NOV 17 2014 A POTENTIAL MODERATION IN TEMPERATURES LATE THIS WEEK HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC SUITE IS IN AGREEMENT ON THE ANOMALOUS HIGH AMPLITUDE UPPER LEVEL PATTERN ACROSS NORTH AMERICA BREAKING DOWN TO A NEAR ZONAL PATTERN BY NEXT WEEKEND IN A BROAD VERY LOW AMPLITUDE TROUGH. THIS WOULD SIGNAL A RECOVERY FROM THE ARCTIC TEMPERATURES TO STILL BELOW NORMAL...YET MORE TOLERABLE HIGHS NEAR FREEZING FRIDAY INTO THE WEEKEND. THE EXTENDED FORECAST LOOKS TO BE LARGELY PRECIPITATION FREE...WITH SPLIT FLOW DEVELOPING AND THE LACK OF MOISTURE RECOVERY FROM THE ARCTIC AIRMASS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 645 AM CST MON NOV 17 2014 CIGS WILL TRANSITION FROM LOW VFR AT KISN/KDIK TO MVFR BETWEEN 15Z-16Z...WITH IMPROVING CONDITIONS TO VFR BY 00Z TUESDAY. ISOLATED FLURRIES ARE POSSIBLE AT KDIK AND KISN THIS MORNING WITH MINIMAL VISIBILITY IMPACTS. LOW VFR CIGS EXPECTED AT KMOT/KBIS/KJMS THROUGH THE PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...AYD AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
335 AM CST MON NOV 17 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CST MON NOV 17 2014 HUDSON BAY UPPER LOW WITH SUCCESSIVE SHORTWAVE TROUGHS ROTATING AROUND HAS CARVED OUT A SIGNIFICANT UPPER TROUGH EXTENDING SOUTH INTO THE MIDWEST AND SOUTHERN PLAINS PER LATEST WATER VAPOR IMAGERY. NORTHERLY FLOW INTO NORTH DAKOTA WITH ANOTHER MINOR SHORTWAVE NOW LOCATED JUST WEST OF LAKE WINNIPEG IS FORECAST TO REACH INTO THE BISMARCK VICINITY BY 18Z TODAY. THE LATEST FOG/STRATUS LOOP SHOWS CLOUDS AND FLURRIES OVER THE SOUTHWEST...WHICH EXTENDS ACROSS MOST OF EASTERN MONTANA. FARTHER UPSTREAM CLOSER TO THE LOCATION OF THE INCOMING SHORTWAVE...QUITE A BIT OF CLOUDS PUSHING SOUTH. THE LATEST HRRR REINFORCES CLOUDS ESPECIALLY IN THE WEST...BUT THINK THE CENTRAL WILL ALSO CLOUD UP DURING THE LATE MORNING AND EARLY AFTERNOON. THE HIGH RESOLUTION ARW AND NMM MODELS CONTINUE WITH THE FLURRIES WEST THROUGH 18Z TODAY AND HAVE FOLLOWED THIS AS THEY ARE VERIFYING THE BEST EARLY THIS MORNING WITH THE CURRENT ACTIVITY. WARM AIR ADVECTION COMMENCES MONDAY NIGHT WITH A PUSH OF H7-H5 MOISTURE. THIS WILL PROGRESS FROM WEST TO EAST OVERNIGHT RESULTING IN PARTLY CLOUDY CONDITIONS. HIGHS TODAY WILL RANGE FROM 10F TO 15F WITH OVERNIGHT LOWS BETWEEN 3 BELOW ZERO TO 3 ABOVE. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 334 AM CST MON NOV 17 2014 A POTENTIAL MODERATION IN TEMPERATURES LATE THIS WEEK HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC SUITE IS IN AGREEMENT ON THE ANOMALOUS HIGH AMPLITUDE UPPER LEVEL PATTERN ACROSS NORTH AMERICA BREAKING DOWN TO A NEAR ZONAL PATTERN BY NEXT WEEKEND IN A BROAD VERY LOW AMPLITUDE TROUGH. THIS WOULD SIGNAL A RECOVERY FROM THE ARCTIC TEMPERATURES TO STILL BELOW NORMAL...YET MORE TOLERABLE HIGHS NEAR FREEZING FRIDAY INTO THE WEEKEND. THE EXTENDED FORECAST LOOKS TO BE LARGELY PRECIPITATION FREE...WITH SPLIT FLOW DEVELOPING AND THE LACK OF MOISTURE RECOVERY FROM THE ARCTIC AIRMASS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 334 AM CST MON NOV 17 2014 CIGS WILL VARY BETWEEN VFR AT KISN/KDIK TO MVFR CONDITIONS DURING THE DAY MONDAY. PERIODIC LOW VFR CIGS ARE FORECAST AT KBIS/KMOT WITH VFR AT KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KS LONG TERM...AYD AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
920 AM EST MON NOV 17 2014 .SYNOPSIS... A STORM SYSTEM WILL MOVE EAST OF THE REGION TODAY. ARCTIC AIR WILL FOLLOW IN THE WAKE OF THE STORM...BRINGING VERY COLD CONDITIONS THROUGH TUESDAY NIGHT. A COLD FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MORNING UPDATE CENTERED ON PULLING THE BACK EDGE OF SNOW FURTHER WEST WHERE IT IS CURRENTLY RIGHT ON WESTERN CWA EDGE. IT WILL BLOW THROUGH PRETTY QUICK THIS LATE MORNING AND I WAS ABLE TO KEEP THE 18Z SNOW FORECAST THE SAME - GENERALLY DRY OVER CWA WITH SOME LINGERING LIGHT STUFF IN THE SCIOTO VALLEY AND HOCKING HILLS. TEMPS AND DEWPOINTS WERE RUNNING ON WITH CURRENT FORECAST. PREV DISC BELOW PRECIPITATION CONTINUES ACROSS ALMOST THE ENTIRE FORECAST AREA EARLY THIS MORNING. CORRELATION COEFFICIENT ON KILN RADAR INDICATES THAT THE RAIN-SNOW LINE EXTENDS FROM ROBERTSON COUNTY NORTHEAST TO HOCKING COUNTY. THIS TRANSITION WILL CONTINUE TO PUSH EAST THROUGH THE MORNING SO THAT ALL AREAS WILL SEE SNOW BEFORE THE PRECIPITATION COMES TO AN END. LATEST HRRR AND RAP RUNS SUGGEST THAT THERE MAY BE A TEMPORARY LULL IN PRECIPITATION OVER THE NEXT FEW HOURS WITH ONE MORE SURGE AFTER 12Z. THIS LAST ROUND OF PRECIPITATION WILL QUICKLY MOVE OFF TO THE EAST OF THE AREA BETWEEN 15Z AND 18Z. WARM GROUND SEEMS TO BE DOING QUITE A JOB IN LIMITING ACCUMULATIONS THUS FAR. THIS IS EVEN MORE SO ON PAVEMENT. A MAJORITY OF ROAD TEMPERATURE SENSORS ACROSS THE FORECAST AREA ARE STILL ABOVE FREEZING BUT ROADS ARE STARTING TO GET COVERED. AND AS SNOW CONTINUES AND GROUND TEMPERATURES FALL IN TANDEM WITH COLDER AIR TEMPERATURES FILTERING IN...SLIPPERY CONDITIONS WILL OCCUR ON AREA ROADS. BASED ON ACCUMULATIONS SEEN THUS FAR HAVE PULLED BACK SLIGHTLY ON STORM TOTAL AMOUNTS. WARNING AREA IS MARGINAL AT THIS POINT BUT WILL KEEP IT GOING FOR NOW WITH ADDITIONAL SNOW COMING. ADVISORY AREA REMAINS UNCHANGED. HIGH TEMPERATURES WILL BE REALIZED EARLY THIS MORNING WITH READINGS FALLING AS ARCTIC AIR SURGES INTO THE REGION. WEST WINDS WILL BECOME GUSTY AND FLURRIES WILL LIKELY DEVELOP IN THE AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... ARCTIC AIR WILL CONTINUE TO POUR INTO THE AREA TONIGHT AND TUESDAY. THIS WILL KEEP GUSTY WINDS GOING. LOW CLOUDS SHOULD PERSIST. CLOUD COVER SHOULD BE ENOUGH TO KEEP LOWS JUST ABOVE RECORD BUT RECORD LOW HIGHS ON TUESDAY ARE A NEAR CERTAINTY. FLURRIES WILL CONTINUE FROM TIME TO TIME. FLOW WILL TURN AROUND TO THE SOUTH TUESDAY NIGHT AHEAD OF THE NEXT SYSTEM BUT TEMPERATURES WILL REMAIN VERY COLD. READINGS WILL REBOUND RELATIVELY SPEAKING ON WEDNESDAY. HOWEVER A COLD FRONT WILL PUSH TOWARDS THE REGION AND THEN MOVE THROUGH WEDNESDAY NIGHT. APPEARS THAT SCATTERED SNOW SHOWERS MAY OCCUR WITH THE BOUNDARY. && .LONG TERM /THURSDAY THROUGH SUNDAY/... FOR THURSDAY THROUGH FRIDAY...MODELS ARE SOMEWHAT DIFFERENT IN REGARDS TO THE AMOUNT OF RESURGING ARCTIC AIR THAT WILL BLEED BACK INTO OUR AREA IN ASSOCIATION WITH SFC HIGH PRESSURE. IT SHOULD BE DRY...BUT TEMPERATURES WILL STILL BE WELL BELOW NORMAL. MODELS KEEP ADVERTISING A PATTERN SHIFT FOR THE UPCOMING WEEKEND AS THE LONGWAVE PATTERN WILL PUSH ARCTIC AIR BACK NORTH INTO CANADA WHILE A SERIES OF WEATHER SYSTEMS MOVING INTO THE REGION WILL BE OF A PACIFIC ORIGIN. THERE ARE SOME TIMING ISSUES BUT IT APPEARS THAT RETURN FLOW/WAA PATTERN ALONG WITH A WEATHER SYSTEM WILL BRING AN INCREASING THREAT FOR SHOWERS SATURDAY NIGHT INTO SUNDAY. TEMPERATURES BY SUNDAY ARE FORECAST TO APPROACH NORMAL HIGHS IN THE MID 40S TO AROUND 50 DEGREES. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... HEAVIEST BURST OF SNOW PULLING THROUGH MOST TAF LOCATIONS AT THIS TIME WITH IFR CIGS AND VSBYS TO CONTINUE THROUGH 14-15Z. SLOW IMPROVEMENT THROUGH THE DAY OF VSBYS WITH VFR EXPECTED ONCE MAIN BAND OF SNOW PULLS OUT...THOUGH LOW MVFR CIGS TO REMAIN THROUGH MUCH OF THE DAY. FLURRIES AND SPOTTY SNOW SHOWERS THIS AFTERNOON WILL BRING A CHANCE FOR MVFR VSBYS THROUGH 00Z...THEN VFR CIGS AFTER ABOUT 05Z. OUTLOOK...SNOW SQUALLS ON TUESDAY COULD YIELD MVFR/IFR CONDITIONS AT TIMES. && .CLIMATE... RECORD LOWS FOR TUESDAY MORNING NOVEMBER 18 CVG...12 DEGREES...1880 CMH...10 DEGREES...1880 DAY...13 DEGREES...1959 RECORD LOW MAX TEMPERATURES ON NOVEMBER 18 CVG...26 DEGREES...1951 CMH...26 DEGREES...1903 DAY...27 DEGREES...1951 AND 1903 && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR OHZ026-034- 035-042>045-051>054-060>062. WINTER STORM WARNING UNTIL NOON EST TODAY FOR OHZ063-064- 070>072-077>080. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR OHZ046-055-056-065-073-074-081-082. KY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR KYZ094>097. WINTER STORM WARNING UNTIL NOON EST TODAY FOR KYZ089>093. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR KYZ098-099. IN...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR INZ050-058- 059. WINTER STORM WARNING UNTIL NOON EST TODAY FOR INZ066-073>075- 080. && $$ SYNOPSIS... NEAR TERM...FRANKS SHORT TERM... LONG TERM...HICKMAN AVIATION...JDR CLIMATE...
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
701 AM EST MON NOV 17 2014 .SYNOPSIS... A STORM SYSTEM WILL MOVE EAST OF THE REGION TODAY. ARCTIC AIR WILL FOLLOW IN THE WAKE OF THE STORM...BRINGING VERY COLD CONDITIONS THROUGH TUESDAY NIGHT. A COLD FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PRECIPITATION CONTINUES ACROSS ALMOST THE ENTIRE FORECAST AREA EARLY THIS MORNING. CORRELATION COEFFICIENT ON KILN RADAR INDICATES THAT THE RAIN-SNOW LINE EXTENDS FROM ROBERTSON COUNTY NORTHEAST TO HOCKING COUNTY. THIS TRANSITION WILL CONTINUE TO PUSH EAST THROUGH THE MORNING SO THAT ALL AREAS WILL SEE SNOW BEFORE THE PRECIPITATION COMES TO AN END. LATEST HRRR AND RAP RUNS SUGGEST THAT THERE MAY BE A TEMPORARY LULL IN PRECIPITATION OVER THE NEXT FEW HOURS WITH ONE MORE SURGE AFTER 12Z. THIS LAST ROUND OF PRECIPITATION WILL QUICKLY MOVE OFF TO THE EAST OF THE AREA BETWEEN 15Z AND 18Z. WARM GROUND SEEMS TO BE DOING QUITE A JOB IN LIMITING ACCUMULATIONS THUS FAR. THIS IS EVEN MORE SO ON PAVEMENT. A MAJORITY OF ROAD TEMPERATURE SENSORS ACROSS THE FORECAST AREA ARE STILL ABOVE FREEZING BUT ROADS ARE STARTING TO GET COVERED. AND AS SNOW CONTINUES AND GROUND TEMPERATURES FALL IN TANDEM WITH COLDER AIR TEMPERATURES FILTERING IN...SLIPPERY CONDITIONS WILL OCCUR ON AREA ROADS. BASED ON ACCUMULATIONS SEEN THUS FAR HAVE PULLED BACK SLIGHTLY ON STORM TOTAL AMOUNTS. WARNING AREA IS MARGINAL AT THIS POINT BUT WILL KEEP IT GOING FOR NOW WITH ADDITIONAL SNOW COMING. ADVISORY AREA REMAINS UNCHANGED. HIGH TEMPERATURES WILL BE REALIZED EARLY THIS MORNING WITH READINGS FALLING AS ARCTIC AIR SURGES INTO THE REGION. WEST WINDS WILL BECOME GUSTY AND FLURRIES WILL LIKELY DEVELOP IN THE AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... ARCTIC AIR WILL CONTINUE TO POUR INTO THE AREA TONIGHT AND TUESDAY. THIS WILL KEEP GUSTY WINDS GOING. LOW CLOUDS SHOULD PERSIST. CLOUD COVER SHOULD BE ENOUGH TO KEEP LOWS JUST ABOVE RECORD BUT RECORD LOW HIGHS ON TUESDAY ARE A NEAR CERTAINTY. FLURRIES WILL CONTINUE FROM TIME TO TIME. FLOW WILL TURN AROUND TO THE SOUTH TUESDAY NIGHT AHEAD OF THE NEXT SYSTEM BUT TEMPERATURES WILL REMAIN VERY COLD. READINGS WILL REBOUND RELATIVELY SPEAKING ON WEDNESDAY. HOWEVER A COLD FRONT WILL PUSH TOWARDS THE REGION AND THEN MOVE THROUGH WEDNESDAY NIGHT. APPEARS THAT SCATTERED SNOW SHOWERS MAY OCCUR WITH THE BOUNDARY. && .LONG TERM /THURSDAY THROUGH SUNDAY/... FOR THURSDAY THROUGH FRIDAY...MODELS ARE SOMEWHAT DIFFERENT IN REGARDS TO THE AMOUNT OF RESURGING ARCTIC AIR THAT WILL BLEED BACK INTO OUR AREA IN ASSOCIATION WITH SFC HIGH PRESSURE. IT SHOULD BE DRY...BUT TEMPERATURES WILL STILL BE WELL BELOW NORMAL. MODELS KEEP ADVERTISING A PATTERN SHIFT FOR THE UPCOMING WEEKEND AS THE LONGWAVE PATTERN WILL PUSH ARCTIC AIR BACK NORTH INTO CANADA WHILE A SERIES OF WEATHER SYSTEMS MOVING INTO THE REGION WILL BE OF A PACIFIC ORIGIN. THERE ARE SOME TIMING ISSUES BUT IT APPEARS THAT RETURN FLOW/WAA PATTERN ALONG WITH A WEATHER SYSTEM WILL BRING AN INCREASING THREAT FOR SHOWERS SATURDAY NIGHT INTO SUNDAY. TEMPERATURES BY SUNDAY ARE FORECAST TO APPROACH NORMAL HIGHS IN THE MID 40S TO AROUND 50 DEGREES. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... HEAVIEST BURST OF SNOW PULLING THROUGH MOST TAF LOCATIONS AT THIS TIME WITH IFR CIGS AND VSBYS TO CONTINUE THROUGH 14-15Z. SLOW IMPROVEMENT THROUGH THE DAY OF VSBYS WITH VFR EXPECTED ONCE MAIN BAND OF SNOW PULLS OUT...THOUGH LOW MVFR CIGS TO REMAIN THROUGH MUCH OF THE DAY. FLURRIES AND SPOTTY SNOW SHOWERS THIS AFTERNOON WILL BRING A CHANCE FOR MVFR VSBYS THROUGH 00Z...THEN VFR CIGS AFTER ABOUT 05Z. OUTLOOK...SNOW SQUALLS ON TUESDAY COULD YIELD MVFR/IFR CONDITIONS AT TIMES. && .CLIMATE... RECORD LOWS FOR TUESDAY MORNING NOVEMBER 18 CVG...12 DEGREES...1880 CMH...10 DEGREES...1880 DAY...13 DEGREES...1959 RECORD LOW MAX TEMPERATURES ON NOVEMBER 18 CVG...26 DEGREES...1951 CMH...26 DEGREES...1903 DAY...27 DEGREES...1951 AND 1903 && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR OHZ026-034- 035-042>045-051>054-060>062. WINTER STORM WARNING UNTIL NOON EST TODAY FOR OHZ063-064- 070>072-077>080. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR OHZ046-055-056-065-073-074-081-082. KY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR KYZ094>097. WINTER STORM WARNING UNTIL NOON EST TODAY FOR KYZ089>093. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR KYZ098-099. IN...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR INZ050-058- 059. WINTER STORM WARNING UNTIL NOON EST TODAY FOR INZ066-073>075- 080. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM...HICKMAN AVIATION...JDR CLIMATE...
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
528 AM EST MON NOV 17 2014 .SYNOPSIS... A STORM SYSTEM WILL MOVE EAST OF THE REGION TODAY. ARCTIC AIR WILL FOLLOW IN THE WAKE OF THE STORM...BRINGING VERY COLD CONDITIONS THROUGH TUESDAY NIGHT. A COLD FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PRECIPITATION CONTINUES ACROSS ALMOST THE ENTIRE FORECAST AREA EARLY THIS MORNING. CORRELATION COEFFICIENT ON KILN RADAR INDICATES THAT THE RAIN-SNOW LINE EXTENDS FROM ROBERTSON COUNTY NORTHEAST TO HOCKING COUNTY. THIS TRANSITION WILL CONTINUE TO PUSH EAST THROUGH THE MORNING SO THAT ALL AREAS WILL SEE SNOW BEFORE THE PRECIPITATION COMES TO AN END. LATEST HRRR AND RAP RUNS SUGGEST THAT THERE MAY BE A TEMPORARY LULL IN PRECIPITATION OVER THE NEXT FEW HOURS WITH ONE MORE SURGE AFTER 12Z. THIS LAST ROUND OF PRECIPITATION WILL QUICKLY MOVE OFF TO THE EAST OF THE AREA BETWEEN 15Z AND 18Z. WARM GROUND SEEMS TO BE DOING QUITE A JOB IN LIMITING ACCUMULATIONS THUS FAR. THIS IS EVEN MORE SO ON PAVEMENT. A MAJORITY OF ROAD TEMPERATURE SENSORS ACROSS THE FORECAST AREA ARE STILL ABOVE FREEZING BUT ROADS ARE STARTING TO GET COVERED. AND AS SNOW CONTINUES AND GROUND TEMPERATURES FALL IN TANDEM WITH COLDER AIR TEMPERATURES FILTERING IN...SLIPPERY CONDITIONS WILL OCCUR ON AREA ROADS. BASED ON ACCUMULATIONS SEEN THUS FAR HAVE PULLED BACK SLIGHTLY ON STORM TOTAL AMOUNTS. WARNING AREA IS MARGINAL AT THIS POINT BUT WILL KEEP IT GOING FOR NOW WITH ADDITIONAL SNOW COMING. ADVISORY AREA REMAINS UNCHANGED. HIGH TEMPERATURES WILL BE REALIZED EARLY THIS MORNING WITH READINGS FALLING AS ARCTIC AIR SURGES INTO THE REGION. WEST WINDS WILL BECOME GUSTY AND FLURRIES WILL LIKELY DEVELOP IN THE AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... ARCTIC AIR WILL CONTINUE TO POUR INTO THE AREA TONIGHT AND TUESDAY. THIS WILL KEEP GUSTY WINDS GOING. LOW CLOUDS SHOULD PERSIST. CLOUD COVER SHOULD BE ENOUGH TO KEEP LOWS JUST ABOVE RECORD BUT RECORD LOW HIGHS ON TUESDAY ARE A NEAR CERTAINTY. FLURRIES WILL CONTINUE FROM TIME TO TIME. FLOW WILL TURN AROUND TO THE SOUTH TUESDAY NIGHT AHEAD OF THE NEXT SYSTEM BUT TEMPERATURES WILL REMAIN VERY COLD. READINGS WILL REBOUND RELATIVELY SPEAKING ON WEDNESDAY. HOWEVER A COLD FRONT WILL PUSH TOWARDS THE REGION AND THEN MOVE THROUGH WEDNESDAY NIGHT. APPEARS THAT SCATTERED SNOW SHOWERS MAY OCCUR WITH THE BOUNDARY. && .LONG TERM /THURSDAY THROUGH SUNDAY/... FOR THURSDAY THROUGH FRIDAY...MODELS ARE SOMEWHAT DIFFERENT IN REGARDS TO THE AMOUNT OF RESURGING ARCTIC AIR THAT WILL BLEED BACK INTO OUR AREA IN ASSOCIATION WITH SFC HIGH PRESSURE. IT SHOULD BE DRY...BUT TEMPERATURES WILL STILL BE WELL BELOW NORMAL. MODELS KEEP ADVERTISING A PATTERN SHIFT FOR THE UPCOMING WEEKEND AS THE LONGWAVE PATTERN WILL PUSH ARCTIC AIR BACK NORTH INTO CANADA WHILE A SERIES OF WEATHER SYSTEMS MOVING INTO THE REGION WILL BE OF A PACIFIC ORIGIN. THERE ARE SOME TIMING ISSUES BUT IT APPEARS THAT RETURN FLOW/WAA PATTERN ALONG WITH A WEATHER SYSTEM WILL BRING AN INCREASING THREAT FOR SHOWERS SATURDAY NIGHT INTO SUNDAY. TEMPERATURES BY SUNDAY ARE FORECAST TO APPROACH NORMAL HIGHS IN THE MID 40S TO AROUND 50 DEGREES. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... PCPN FROM THE APPROACHING WINTER STORM HAS YET TO REALLY AFFECT THE MAJORITY OF THE TAFS. THE ONE EXCEPTION IS KDAY WHEN THE IFR SNOW HAS ALREADY STARTED. SRN TAFS HAVE SEEN THEIR CIGS ALREADY FALL TO IFR WHILE THE CENTRAL OHIO TAFS ARE STILL MVFR. SNOW SHOULD FILL IN ACROSS SRN INDIANA/NRN KENTUCKY AND LIFT UP THE I-71 CORRIDOR. WORST CONDITIONS WILL OCCUR BETWEEN 06-12Z. AT KCMH/KLCK THE PCPN SHOULD STAY RAIN LONGER...PAST 06Z...BEFORE CHANGING TO SNOW. EXPECT IFR CONDITIONS FOR ALL THE TAFS AFT 06Z. LATEST RUNS OF THE MODELS ARE A LITTLE SLOWER WITH THE BACK EDGE...SO HELD ONTO LOWER CIGS AND VSBYS UNTIL 13-15Z. AS THE PCPN ENDS...WINDS WILL SHIFT TO THE WEST AND INCREASE TO 10-15KT...WITH GUSTS INTO THE 20S. CAA ALOFT ON THE AFTERNOON MAY LEAD TO SOME SCATTERED SNOW SHOWERS REDUCING CONDITIONS TO MVFR. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WITH SCATTERED SNOW SHOWERS ARE POSSIBLE MONDAY AFTERNOON/EVENING. SNOW SQUALLS AGAIN ON TUESDAY COULD YIELD MVFR/IFR CONDITIONS AT TIMES. && .CLIMATE... RECORD LOWS FOR TUESDAY MORNING NOVEMBER 18 CVG...12 DEGREES...1880 CMH...10 DEGREES...1880 DAY...13 DEGREES...1959 RECORD LOW MAX TEMPERATURES ON NOVEMBER 18 CVG...26 DEGREES...1951 CMH...26 DEGREES...1903 DAY...27 DEGREES...1951 AND 1903 && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR OHZ026-034- 035-042>045-051>054-060>062. WINTER STORM WARNING UNTIL NOON EST TODAY FOR OHZ063-064- 070>072-077>080. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR OHZ046-055-056-065-073-074-081-082. KY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR KYZ094>097. WINTER STORM WARNING UNTIL NOON EST TODAY FOR KYZ089>093. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR KYZ098-099. IN...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR INZ050-058- 059. WINTER STORM WARNING UNTIL NOON EST TODAY FOR INZ066-073>075- 080. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM...HICKMAN AVIATION...JDR CLIMATE...
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1208 PM CST MON NOV 17 2014 .DISCUSSION... UPDATED FOR THE 18Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 1037 AM CST MON NOV 17 2014/ UPDATE... STARTING TO SEE WHAT MAY BE THE BEGINNING OF OUR AFTERNOON FLURRIES DEVELOPING OVER MISSOURI...SO WILL HANG ON TO THE PREVIOUS FORECAST. TEMPERATURES HAVE WARMED TO NEAR OR EVEN SLIGHTLY FREEZING AT THE WARMEST LOCATIONS ACROSS THE MIDSOUTH...BUT NORTH WIND WILL KEEP CONDITIONS FROM WARMING MUCH MORE TODAY. STAY WARM. && .PREV DISCUSSION... /ISSUED 441 AM CST MON NOV 17 2014/ CURRENTLY...BANDS OF LIGHT SNOW ARE MOVING ACROSS THE NORTHERN HALF OF THE MIDSOUTH. SOME SLEET HAS BEEN MIXED IN AROUND THE MEMPHIS AREA. DECIDED TO GO AHEAD AND EXPAND THE ADVISORY TO INCLUDE MOST OF THE I-40 CORRIDOR SINCE BRIDGES AND OVERPASSES COULD BECOME SLICK AHEAD OF THE MONDAY MORNING COMMUTE AS TEMPS FALL BELOW FREEZING. LATEST HRRR PULLS THESE BANDS NE AND OUT OF THE AREA BY 7 OR 8 AM. MEANWHILE RAIN HAS CLEARED OUT OF NORTH MISSISSIPPI. TODAY...PRECIP WILL QUICKLY EXIT THIS MORNING AND SOME TEMPORARY CLEARING WILL OCCUR. MEANWHILE MUCH COLDER AIR WILL FILTER IN ON BRISK NW WINDS. EXPECT COLD AIR STRATOCU TO DEVELOP AND MOVE INTO THE AREA FROM THE NORTH AS 850 MB TEMPS DROP TO -14C AS FAR SOUTH AS THE I-40 CORRIDOR THIS AFTERNOON. THE NAM 925 MB RH FIELDS DEPICT THIS WELL. SOME FLURRIES ARE ALSO POSSIBLE ACROSS THE NORTH HALF THIS AFTERNOON. TEMPS WILL BE VERY COLD WITH HIGHS AROUND 30 NEAR THE KY/MO BORDERS TO AROUND 40 SOUTH. TONIGHT THROUGH TUESDAY NIGHT...ARCTIC HIGH PRESSURE SETTLES OVER THE REGION. VERY COLD TONIGHT WITH TEMPS DROPPING WELL INTO THE TEENS. WOULD GO COLDER THAN GUIDANCE EXCEPT THERE IS SOME GRADIENT LEFT ACROSS THE AREA WHICH WILL KEEP WINDS UP A BIT. THIS OF COURSE WILL CAUSE WIND CHILLS TO DROPS INTO THE SINGLE DIGITS ACROSS THE NORTH HALF BY TUESDAY MORNING. TUESDAY WILL BE VERY COLD WITH UPPER 20S NEAR PARIS TO MID 30S SOUTH. THIS IS PUSHING 35 DEGREES BELOW NORMAL. TEMPS WILL FALL QUICKLY INTO THE 20S TUESDAY EVENING AND THEN LEVEL OFF AS SOUTH WINDS DEVELOP AHEAD OF AN APPROACHING SURFACE TROF. WEDNESDAY AND WEDNESDAY NIGHT...SURFACE TROF MOVES THROUGH WITH WARMER SW WINDS ACROSS THE AREA AND TEMPS SHOULD CLIMB INTO THE UPPER 40S AND LOWER 50S...WHICH THOUGH PLEASANT SOUNDING IS STILL 10 DEGREES BELOW NORMAL. WEAK HIGH PRESSURE PREVAILS WEDNESDAY NIGHT WITH WITH LOWS IN THE 20S AND 30S. THURSDAY THROUGH THE WEEKEND...00Z MEDIUM RANGE MODELS ARE IN MUCH BETTER AGREEMENT TODAY. A MAJOR PATTERN SHIFT WILL OCCUR AS THE COLD UPPER TROF PUSHES EAST AND THE UPPER FLOW BECOME ZONAL BY THE END OF THE WEEK. AN OVERRUNNING PATTERN SETS UP AS A DISTURBANCE MOVES THROUGH IN THE ZONAL FLOW ALOFT. AS A RESULT EXPECT RAIN CHANCES THURSDAY NIGHT AND FRIDAY. BY SATURDAY A BROAD UPPER RIDGE WILL BUILD OVER THE AREA AS A POTENT MID LEVEL TROF PUSHES OUT OF THE SW U.S. INTO TEXAS. AS A RESULT EXPECT WARMER AIR TO START MOVING NORTH INTO THE MIDSOUTH WITH HIGHS IN THE 50S AND 60S. BY SAT NIGHT AND SUNDAY THE UPPER TROF WILL PUSH THROUGH WITH SHOWERS AND THUNDERSTORMS LIKELY. SJM && .AVIATION... 18Z TAF CYCLE VFR CIGS AND VSBYS WILL CONTINUE FOR THE NEXT COUPLE OF HOURS AT ALL SITES. MVFR CIGS WILL LIKELY DEVELOP AT KJBR AND KMKL BY MID AFTERNOON AS STRATOCUMULUS DEVELOPS. THERE MAY BE ENOUGH INSTABILITY WITHIN FAVORABLE DENDRITIC ZONE TO SUPPORT SOME SNOW SHOWERS AFTER 21Z AT KMKL. KEPT VSBYS P6SM AT KMKL FOR AFTER 21Z...BUT THIS WILL NEED TO BE MONITORED CLOSELY AS HEAVIER SNOW SHOWERS COULD REDUCE VSBYS. ELSEWHERE...A FEW FLURRIES WILL BE POSSIBLE BUT NOT EXPECTING ANY VSBY REDUCTIONS. VFR CIGS WILL PREVAIL AT BOTH KMEM AND KTUP THROUGH THE AFTERNOON AND EARLY EVENING. GUSTY NORTHWEST WINDS WILL CONTINUE AT ALL SITES THROUGH EARLY EVENING. STRATOCUMULUS WILL SCATTER OUT THIS EVENING WITH SKIES CLEARING AT ALL LOCATIONS OVERNIGHT. WINDS WILL ALSO DIMINISH THROUGH THE EVENING HOURS TO 6 KTS OR LESS FROM THE NORTHWEST. CLEAR SKIES WILL PERSIST AT ALL SITES TUESDAY MORNING WITH WINDS INCREASING TO BETWEEN 8-10 KTS FROM THE WEST NORTHWEST. JLH && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1037 AM CST MON NOV 17 2014 .UPDATE... STARTING TO SEE WHAT MAY BE THE BEGINNING OF OUR AFTERNOON FLURRIES DEVELOPING OVER MISSOURI...SO WILL HANG ON TO THE PREVIOUS FORECAST. TEMPERATURES HAVE WARMED TO NEAR OR EVEN SLIGHTLY FREEZING AT THE WARMEST LOCATIONS ACROSS THE MIDSOUTH...BUT NORTH WIND WILL KEEP CONDITIONS FROM WARMING MUCH MORE TODAY. STAY WARM. && .PREV DISCUSSION... /ISSUED 714 AM CST MON NOV 17 2014/ DISCUSSION... WIND WEATHER ADVISORIES HAVE BEEN CANCELLED AS PRECIPITATION HAS MOVED EAST. PREV DISCUSSION... /ISSUED 441 AM CST MON NOV 17 2014/ CURRENTLY...BANDS OF LIGHT SNOW ARE MOVING ACROSS THE NORTHERN HALF OF THE MIDSOUTH. SOME SLEET HAS BEEN MIXED IN AROUND THE MEMPHIS AREA. DECIDED TO GO AHEAD AND EXPAND THE ADVISORY TO INCLUDE MOST OF THE I-40 CORRIDOR SINCE BRIDGES AND OVERPASSES COULD BECOME SLICK AHEAD OF THE MONDAY MORNING COMMUTE AS TEMPS FALL BELOW FREEZING. LATEST HRRR PULLS THESE BANDS NE AND OUT OF THE AREA BY 7 OR 8 AM. MEANWHILE RAIN HAS CLEARED OUT OF NORTH MISSISSIPPI. TODAY...PRECIP WILL QUICKLY EXIT THIS MORNING AND SOME TEMPORARY CLEARING WILL OCCUR. MEANWHILE MUCH COLDER AIR WILL FILTER IN ON BRISK NW WINDS. EXPECT COLD AIR STRATOCU TO DEVELOP AND MOVE INTO THE AREA FROM THE NORTH AS 850 MB TEMPS DROP TO -14C AS FAR SOUTH AS THE I-40 CORRIDOR THIS AFTERNOON. THE NAM 925 MB RH FIELDS DEPICT THIS WELL. SOME FLURRIES ARE ALSO POSSIBLE ACROSS THE NORTH HALF THIS AFTERNOON. TEMPS WILL BE VERY COLD WITH HIGHS AROUND 30 NEAR THE KY/MO BORDERS TO AROUND 40 SOUTH. TONIGHT THROUGH TUESDAY NIGHT...ARCTIC HIGH PRESSURE SETTLES OVER THE REGION. VERY COLD TONIGHT WITH TEMPS DROPPING WELL INTO THE TEENS. WOULD GO COLDER THAN GUIDANCE EXCEPT THERE IS SOME GRADIENT LEFT ACROSS THE AREA WHICH WILL KEEP WINDS UP A BIT. THIS OF COURSE WILL CAUSE WIND CHILLS TO DROPS INTO THE SINGLE DIGITS ACROSS THE NORTH HALF BY TUESDAY MORNING. TUESDAY WILL BE VERY COLD WITH UPPER 20S NEAR PARIS TO MID 30S SOUTH. THIS IS PUSHING 35 DEGREES BELOW NORMAL. TEMPS WILL FALL QUICKLY INTO THE 20S TUESDAY EVENING AND THEN LEVEL OFF AS SOUTH WINDS DEVELOP AHEAD OF AN APPROACHING SURFACE TROF. WEDNESDAY AND WEDNESDAY NIGHT...SURFACE TROF MOVES THROUGH WITH WARMER SW WINDS ACROSS THE AREA AND TEMPS SHOULD CLIMB INTO THE UPPER 40S AND LOWER 50S...WHICH THOUGH PLEASANT SOUNDING IS STILL 10 DEGREES BELOW NORMAL. WEAK HIGH PRESSURE PREVAILS WEDNESDAY NIGHT WITH WITH LOWS IN THE 20S AND 30S. THURSDAY THROUGH THE WEEKEND...00Z MEDIUM RANGE MODELS ARE IN MUCH BETTER AGREEMENT TODAY. A MAJOR PATTERN SHIFT WILL OCCUR AS THE COLD UPPER TROF PUSHES EAST AND THE UPPER FLOW BECOME ZONAL BY THE END OF THE WEEK. AN OVERRUNNING PATTERN SETS UP AS A DISTURBANCE MOVES THROUGH IN THE ZONAL FLOW ALOFT. AS A RESULT EXPECT RAIN CHANCES THURSDAY NIGHT AND FRIDAY. BY SATURDAY A BROAD UPPER RIDGE WILL BUILD OVER THE AREA AS A POTENT MID LEVEL TROF PUSHES OUT OF THE SW U.S. INTO TEXAS. AS A RESULT EXPECT WARMER AIR TO START MOVING NORTH INTO THE MIDSOUTH WITH HIGHS IN THE 50S AND 60S. BY SAT NIGHT AND SUNDAY THE UPPER TROF WILL PUSH THROUGH WITH SHOWERS AND THUNDERSTORMS LIKELY. SJM AVIATION... 12Z TAFS BRIEF VFR WEATHER NOW SHIFTING INTO MEM AND JBR...AND WILL FOLLOW SUITE THIS MORNING AT MKL AND TUP. FOR THIS AFTERNOON EXPECTING A MVFR DECK TO REFORM...WITH LIGHT SNOW FLURRIES ALSO REDVELOPING. SECOND CLEARING OF SKY COVER WILL ARRIVE TONIGHT. NORTHWEST TO NORTH WINDS AT 12-14KTS WITH FREQUENT GUSTS OF 18-20 KTS. WINDS WILL DIMINISH FOR THE LATTER HALF OF THE CYCLE. JAB && .AVIATION... && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
714 AM CST MON NOV 17 2014 .DISCUSSION... WIND WEATHER ADVISORIES HAVE BEEN CANCELLED AS PRECIPITATION HAS MOVED EAST. && PREV DISCUSSION... /ISSUED 441 AM CST MON NOV 17 2014/ CURRENTLY...BANDS OF LIGHT SNOW ARE MOVING ACROSS THE NORTHERN HALF OF THE MIDSOUTH. SOME SLEET HAS BEEN MIXED IN AROUND THE MEMPHIS AREA. DECIDED TO GO AHEAD AND EXPAND THE ADVISORY TO INCLUDE MOST OF THE I-40 CORRIDOR SINCE BRIDGES AND OVERPASSES COULD BECOME SLICK AHEAD OF THE MONDAY MORNING COMMUTE AS TEMPS FALL BELOW FREEZING. LATEST HRRR PULLS THESE BANDS NE AND OUT OF THE AREA BY 7 OR 8 AM. MEANWHILE RAIN HAS CLEARED OUT OF NORTH MISSISSIPPI. TODAY...PRECIP WILL QUICKLY EXIT THIS MORNING AND SOME TEMPORARY CLEARING WILL OCCUR. MEANWHILE MUCH COLDER AIR WILL FILTER IN ON BRISK NW WINDS. EXPECT COLD AIR STRATOCU TO DEVELOP AND MOVE INTO THE AREA FROM THE NORTH AS 850 MB TEMPS DROP TO -14C AS FAR SOUTH AS THE I-40 CORRIDOR THIS AFTERNOON. THE NAM 925 MB RH FIELDS DEPICT THIS WELL. SOME FLURRIES ARE ALSO POSSIBLE ACROSS THE NORTH HALF THIS AFTERNOON. TEMPS WILL BE VERY COLD WITH HIGHS AROUND 30 NEAR THE KY/MO BORDERS TO AROUND 40 SOUTH. TONIGHT THROUGH TUESDAY NIGHT...ARCTIC HIGH PRESSURE SETTLES OVER THE REGION. VERY COLD TONIGHT WITH TEMPS DROPPING WELL INTO THE TEENS. WOULD GO COLDER THAN GUIDANCE EXCEPT THERE IS SOME GRADIENT LEFT ACROSS THE AREA WHICH WILL KEEP WINDS UP A BIT. THIS OF COURSE WILL CAUSE WIND CHILLS TO DROPS INTO THE SINGLE DIGITS ACROSS THE NORTH HALF BY TUESDAY MORNING. TUESDAY WILL BE VERY COLD WITH UPPER 20S NEAR PARIS TO MID 30S SOUTH. THIS IS PUSHING 35 DEGREES BELOW NORMAL. TEMPS WILL FALL QUICKLY INTO THE 20S TUESDAY EVENING AND THEN LEVEL OFF AS SOUTH WINDS DEVELOP AHEAD OF AN APPROACHING SURFACE TROF. WEDNESDAY AND WEDNESDAY NIGHT...SURFACE TROF MOVES THROUGH WITH WARMER SW WINDS ACROSS THE AREA AND TEMPS SHOULD CLIMB INTO THE UPPER 40S AND LOWER 50S...WHICH THOUGH PLEASANT SOUNDING IS STILL 10 DEGREES BELOW NORMAL. WEAK HIGH PRESSURE PREVAILS WEDNESDAY NIGHT WITH WITH LOWS IN THE 20S AND 30S. THURSDAY THROUGH THE WEEKEND...00Z MEDIUM RANGE MODELS ARE IN MUCH BETTER AGREEMENT TODAY. A MAJOR PATTERN SHIFT WILL OCCUR AS THE COLD UPPER TROF PUSHES EAST AND THE UPPER FLOW BECOME ZONAL BY THE END OF THE WEEK. AN OVERRUNNING PATTERN SETS UP AS A DISTURBANCE MOVES THROUGH IN THE ZONAL FLOW ALOFT. AS A RESULT EXPECT RAIN CHANCES THURSDAY NIGHT AND FRIDAY. BY SATURDAY A BROAD UPPER RIDGE WILL BUILD OVER THE AREA AS A POTENT MID LEVEL TROF PUSHES OUT OF THE SW U.S. INTO TEXAS. AS A RESULT EXPECT WARMER AIR TO START MOVING NORTH INTO THE MIDSOUTH WITH HIGHS IN THE 50S AND 60S. BY SAT NIGHT AND SUNDAY THE UPPER TROF WILL PUSH THROUGH WITH SHOWERS AND THUNDERSTORMS LIKELY. SJM && .AVIATION... 12Z TAFS BRIEF VFR WEATHER NOW SHIFTING INTO MEM AND JBR...AND WILL FOLLOW SUITE THIS MORNING AT MKL AND TUP. FOR THIS AFTERNOON EXPECTING A MVFR DECK TO REFORM...WITH LIGHT SNOW FLURRIES ALSO REDVELOPING. SECOND CLEARING OF SKY COVER WILL ARRIVE TONIGHT. NORTHWEST TO NORTH WINDS AT 12-14KTS WITH FREQUENT GUSTS OF 18-20 KTS. WINDS WILL DIMINISH FOR THE LATTER HALF OF THE CYCLE. JAB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
521 AM CST MON NOV 17 2014 .DISCUSSION... UPDATED FOR 12Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 441 AM CST MON NOV 17 2014/ DISCUSSION... CURRENTLY...BANDS OF LIGHT SNOW ARE MOVING ACROSS THE NORTHERN HALF OF THE MIDSOUTH. SOME SLEET HAS BEEN MIXED IN AROUND THE MEMPHIS AREA. DECIDED TO GO AHEAD AND EXPAND THE ADVISORY TO INCLUDE MOST OF THE I-40 CORRIDOR SINCE BRIDGES AND OVERPASSES COULD BECOME SLICK AHEAD OF THE MONDAY MORNING COMMUTE AS TEMPS FALL BELOW FREEZING. LATEST HRRR PULLS THESE BANDS NE AND OUT OF THE AREA BY 7 OR 8 AM. MEANWHILE RAIN HAS CLEARED OUT OF NORTH MISSISSIPPI. TODAY...PRECIP WILL QUICKLY EXIT THIS MORNING AND SOME TEMPORARY CLEARING WILL OCCUR. MEANWHILE MUCH COLDER AIR WILL FILTER IN ON BRISK NW WINDS. EXPECT COLD AIR STRATOCU TO DEVELOP AND MOVE INTO THE AREA FROM THE NORTH AS 850 MB TEMPS DROP TO -14C AS FAR SOUTH AS THE I-40 CORRIDOR THIS AFTERNOON. THE NAM 925 MB RH FIELDS DEPICT THIS WELL. SOME FLURRIES ARE ALSO POSSIBLE ACROSS THE NORTH HALF THIS AFTERNOON. TEMPS WILL BE VERY COLD WITH HIGHS AROUND 30 NEAR THE KY/MO BORDERS TO AROUND 40 SOUTH. TONIGHT THROUGH TUESDAY NIGHT...ARCTIC HIGH PRESSURE SETTLES OVER THE REGION. VERY COLD TONIGHT WITH TEMPS DROPPING WELL INTO THE TEENS. WOULD GO COLDER THAN GUIDANCE EXCEPT THERE IS SOME GRADIENT LEFT ACROSS THE AREA WHICH WILL KEEP WINDS UP A BIT. THIS OF COURSE WILL CAUSE WIND CHILLS TO DROPS INTO THE SINGLE DIGITS ACROSS THE NORTH HALF BY TUESDAY MORNING. TUESDAY WILL BE VERY COLD WITH UPPER 20S NEAR PARIS TO MID 30S SOUTH. THIS IS PUSHING 35 DEGREES BELOW NORMAL. TEMPS WILL FALL QUICKLY INTO THE 20S TUESDAY EVENING AND THEN LEVEL OFF AS SOUTH WINDS DEVELOP AHEAD OF AN APPROACHING SURFACE TROF. WEDNESDAY AND WEDNESDAY NIGHT...SURFACE TROF MOVES THROUGH WITH WARMER SW WINDS ACROSS THE AREA AND TEMPS SHOULD CLIMB INTO THE UPPER 40S AND LOWER 50S...WHICH THOUGH PLEASANT SOUNDING IS STILL 10 DEGREES BELOW NORMAL. WEAK HIGH PRESSURE PREVAILS WEDNESDAY NIGHT WITH WITH LOWS IN THE 20S AND 30S. THURSDAY THROUGH THE WEEKEND...00Z MEDIUM RANGE MODELS ARE IN MUCH BETTER AGREEMENT TODAY. A MAJOR PATTERN SHIFT WILL OCCUR AS THE COLD UPPER TROF PUSHES EAST AND THE UPPER FLOW BECOME ZONAL BY THE END OF THE WEEK. AN OVERRUNNING PATTERN SETS UP AS A DISTURBANCE MOVES THROUGH IN THE ZONAL FLOW ALOFT. AS A RESULT EXPECT RAIN CHANCES THURSDAY NIGHT AND FRIDAY. BY SATURDAY A BROAD UPPER RIDGE WILL BUILD OVER THE AREA AS A POTENT MID LEVEL TROF PUSHES OUT OF THE SW U.S. INTO TEXAS. AS A RESULT EXPECT WARMER AIR TO START MOVING NORTH INTO THE MIDSOUTH WITH HIGHS IN THE 50S AND 60S. BY SAT NIGHT AND SUNDAY THE UPPER TROF WILL PUSH THROUGH WITH SHOWERS AND THUNDERSTORMS LIKELY. SJM && .AVIATION... 12Z TAFS BRIEF VFR WEATHER NOW SHIFTING INTO MEM AND JBR...AND WILL FOLLOW SUITE THIS MORNING AT MKL AND TUP. FOR THIS AFTERNOON EXPECTING A MVFR DECK TO REFORM...WITH LIGHT SNOW FLURRIES ALSO REDVELOPING. SECOND CLEARING OF SKY COVER WILL ARRIVE TONIGHT. NORTHWEST TO NORTH WINDS AT 12-14KTS WITH FREQUENT GUSTS OF 18-20 KTS. WINDS WILL DIMINISH FOR THE LATTER HALF OF THE CYCLE. JAB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR CLAY-CRAIGHEAD-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH. WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR CRITTENDEN. MO...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR DUNKLIN-PEMISCOT. MS...WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR DESOTO. TN...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR LAKE-OBION. WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR BENTON TN-CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON- HARDEMAN-HAYWOOD-HENDERSON-HENRY-LAUDERDALE-MADISON-SHELBY- TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
441 AM CST MON NOV 17 2014 .DISCUSSION... CURRENTLY...BANDS OF LIGHT SNOW ARE MOVING ACROSS THE NORTHERN HALF OF THE MIDSOUTH. SOME SLEET HAS BEEN MIXED IN AROUND THE MEMPHIS AREA. DECIDED TO GO AHEAD AND EXPAND THE ADVISORY TO INCLUDE MOST OF THE I-40 CORRIDOR SINCE BRIDGES AND OVERPASSES COULD BECOME SLICK AHEAD OF THE MONDAY MORNING COMMUTE AS TEMPS FALL BELOW FREEZING. LATEST HRRR PULLS THESE BANDS NE AND OUT OF THE AREA BY 7 OR 8 AM. MEANWHILE RAIN HAS CLEARED OUT OF NORTH MISSISSIPPI. TODAY...PRECIP WILL QUICKLY EXIT THIS MORNING AND SOME TEMPORARY CLEARING WILL OCCUR. MEANWHILE MUCH COLDER AIR WILL FILTER IN ON BRISK NW WINDS. EXPECT COLD AIR STRATOCU TO DEVELOP AND MOVE INTO THE AREA FROM THE NORTH AS 850 MB TEMPS DROP TO -14C AS FAR SOUTH AS THE I-40 CORRIDOR THIS AFTERNOON. THE NAM 925 MB RH FIELDS DEPICT THIS WELL. SOME FLURRIES ARE ALSO POSSIBLE ACROSS THE NORTH HALF THIS AFTERNOON. TEMPS WILL BE VERY COLD WITH HIGHS AROUND 30 NEAR THE KY/MO BORDERS TO AROUND 40 SOUTH. TONIGHT THROUGH TUESDAY NIGHT...ARCTIC HIGH PRESSURE SETTLES OVER THE REGION. VERY COLD TONIGHT WITH TEMPS DROPPING WELL INTO THE TEENS. WOULD GO COLDER THAN GUIDANCE EXCEPT THERE IS SOME GRADIENT LEFT ACROSS THE AREA WHICH WILL KEEP WINDS UP A BIT. THIS OF COURSE WILL CAUSE WIND CHILLS TO DROPS INTO THE SINGLE DIGITS ACROSS THE NORTH HALF BY TUESDAY MORNING. TUESDAY WILL BE VERY COLD WITH UPPER 20S NEAR PARIS TO MID 30S SOUTH. THIS IS PUSHING 35 DEGREES BELOW NORMAL. TEMPS WILL FALL QUICKLY INTO THE 20S TUESDAY EVENING AND THEN LEVEL OFF AS SOUTH WINDS DEVELOP AHEAD OF AN APPROACHING SURFACE TROF. WEDNESDAY AND WEDNESDAY NIGHT...SURFACE TROF MOVES THROUGH WITH WARMER SW WINDS ACROSS THE AREA AND TEMPS SHOULD CLIMB INTO THE UPPER 40S AND LOWER 50S...WHICH THOUGH PLEASANT SOUNDING IS STILL 10 DEGREES BELOW NORMAL. WEAK HIGH PRESSURE PREVAILS WEDNESDAY NIGHT WITH WITH LOWS IN THE 20S AND 30S. THURSDAY THROUGH THE WEEKEND...00Z MEDIUM RANGE MODELS ARE IN MUCH BETTER AGREEMENT TODAY. A MAJOR PATTERN SHIFT WILL OCCUR AS THE COLD UPPER TROF PUSHES EAST AND THE UPPER FLOW BECOME ZONAL BY THE END OF THE WEEK. AN OVERRUNNING PATTERN SETS UP AS A DISTURBANCE MOVES THROUGH IN THE ZONAL FLOW ALOFT. AS A RESULT EXPECT RAIN CHANCES THURSDAY NIGHT AND FRIDAY. BY SATURDAY A BROAD UPPER RIDGE WILL BUILD OVER THE AREA AS A POTENT MID LEVEL TROF PUSHES OUT OF THE SW U.S. INTO TEXAS. AS A RESULT EXPECT WARMER AIR TO START MOVING NORTH INTO THE MIDSOUTH WITH HIGHS IN THE 50S AND 60S. BY SAT NIGHT AND SUNDAY THE UPPER TROF WILL PUSH THROUGH WITH SHOWERS AND THUNDERSTORMS LIKELY. SJM && .AVIATION... 06Z TAFS LIGHT WINTRY PRECIP EVENT UNDERWAY AT LATE EVENING FOR JBR AND FOR A FEW HOURS DURING THE OVERNIGHT...MEM AND MKL. PL POTENTIAL APPEARS A BIT LESS AT MEM WITH RADAR RETURNS MORE INDICATIVE OF SNOW ALOFT. NONETHELESS...CAN/T RULE OUT A VERY BRIEF PL EPISODE AT MEM THROUGH 08Z. SN ACCUMULATION AT MEM SHOULD BE 1/2 INCH OR LESS ON ELEVATED SURFACES. VFR WILL PREVAIL AREAWIDE ON MONDAY...WITH VERY DRY REINFORCING ARCTIC AIR FLOWING INTO THE MIDSOUTH. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR CLAY-CRAIGHEAD-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH. WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR CRITTENDEN. MO...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR DUNKLIN-PEMISCOT. MS...WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR DESOTO. TN...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR LAKE-OBION. WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR BENTON TN-CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON- HARDEMAN-HAYWOOD-HENDERSON-HENRY-LAUDERDALE-MADISON-SHELBY- TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1135 AM CST MON NOV 17 2014 .AVIATION... VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. LIGHT AND VARIABLE WINDS THIS MORNING WILL COME AROUND TO THE SOUTHWEST BUT GENERALLY REMAIN UNDER 10 KTS. && .PREV DISCUSSION... /ISSUED 527 AM CST MON NOV 17 2014/ AVIATION... VFR AND SKC WITH LIGHT WINDS THRU 18/12Z. PREV DISCUSSION... /ISSUED 412 AM CST MON NOV 17 2014/ SHORT TERM... DEEP AND DRY NORTHERLY FLOW OCCUPIED THE ENTIRE EXTENT OF THE GREAT PLAINS THIS MORNING AND THIS THEME WILL REMAIN INTACT THROUGH TONIGHT. A BROAD MERIDIONAL SURFACE RIDGE ANCHORED IN THE LEE OF THE ROCKIES WILL SHIFT SLOWLY EAST TODAY AND BE LOCATED OFF THE CAPROCK BY THE AFTERNOON AHEAD OF MILDER SW BREEZES. SNOWPACK COLOR CURVE ON IR IMAGERY SHOWS THAT THE NAM AND RUC INITIALIZED THE SNOW COVER RATHER WELL ACROSS OUR NORTHERN TWO ROWS OF COUNTIES...SO WITH THIS IN MIND WE HAVE SCALED BACK MAX TEMPS IN THESE AREAS AS 1 TO 3 INCHES OF SNOW WILL CERTAINLY STUNT RADIATIONAL WARMING...ESPECIALLY AFTER SOME BITTER LOWS TO START THE DAY. AWAY FROM THE SNOW COVER... WENT WITH THE MILD MET NUMBERS AS THESE DRY AIRMASSES OFTEN WARM SURPRISINGLY FAST UNDER FULL SUN WITH DOWNSLOPING WINDS. STEADY SW WINDS AREA WIDE TONIGHT WILL MAKE FOR MILDER LOWS...HOWEVER EVEN THESE ARE STILL 10 TO 20 DEGREES BELOW CLIMO. LONG TERM... PROGRESSIVE PATTERN WILL DEVELOP THIS WEEK WITH A WEAK SHORTWAVE MOVING OVER THE REGION TOMORROW. THIS WAVE WILL BRING LITTLE IN THE WAY OF SENSIBLE WEATHER CHANGES. A BIT STRONGER SHORTWAVE WILL MOVE OVER THE AREA DURING THE DAY THURSDAY WHICH THE MODELS HAVE SLIGHT TIMING AND STRENGTH DIFFERENCES. AHEAD OF THIS SHORTWAVE TROUGH...LOW LEVEL MOISTURE WILL TRY TO STREAM NORTHWARD AND SOME BOUNDARY LAYER MOISTURE MAY MANAGE TO MAKE IT INTO THE ROLLING PLAINS. INCREASED HIGH CLOUDS WITH THIS WAVE ALONG WITH THE INCREASED MOISTURE MAY LIMIT THE AMOUNT OF WARMING THAT WILL TAKE PLACE. WITH THE BEST MOISTURE RETURN TAKING PLACE EAST OF THE FORECAST AREA...RAIN CHANCES LOOK TO STAY TOO FAR TO THE EAST OF US TO PUT ANY MENTION IN THE FORECAST. AS THIS WAVE PASSES BY...A WEAK COLD FRONT WILL MOVE ACROSS THE AREA BUT ONLY DROP TEMPS BY A FEW DEGREES. A MUCH STRONGER WAVE IS FORECAST TO MOVE OVER THE REGION DURING THE DAY SATURDAY. MODELS ARE STILL STRUGGLING WITH HOW STRONG THIS WAVE WILL BE. REGARDLESS...BOUNDARY LAYER MOISTURE CREEPS INTO THE ROLLING PLAINS AND ONTO THE CAPROCK BY SATURDAY AFTERNOON. IF THE CURRENT SOLUTIONS HOLD TRUE...WE MAY SEE SOME SHOWER/THUNDERSTORM ACTIVITY ACROSS THE REGION. DID NOT FEEL CONFIDENT ENOUGH TO GO WITH LOW- END CHANCE AT THIS TIME BUT DID BRING SLIGHT CHANCE POPS ACROSS ALL BUT THE NORTHWESTERN SOUTH PLAINS. JORDAN && .PRELIMINARY POINT TEMPS/POPS... FRIONA 34 14 46 24 49 / 0 0 0 0 0 TULIA 35 16 47 26 50 / 0 0 0 0 0 PLAINVIEW 37 18 48 26 51 / 0 0 0 0 0 LEVELLAND 39 20 49 27 52 / 0 0 0 0 0 LUBBOCK 40 19 48 28 52 / 0 0 0 0 0 DENVER CITY 39 21 50 27 54 / 0 0 0 0 0 BROWNFIELD 40 21 50 28 53 / 0 0 0 0 0 CHILDRESS 37 20 50 29 54 / 0 0 0 0 0 SPUR 41 22 49 31 54 / 0 0 0 0 0 ASPERMONT 42 22 51 32 57 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1119 AM CST MON NOV 17 2014 .UPDATE...UPDATE FOR 18Z AVIATION BELOW. && .AVIATION...VFR CONDITIONS THROUGH THE TAF PERIOD. CLEAR SKIES TODAY WITH HIGH CIRRUS POSSIBLE OVERNIGHT. N WINDS 10-15 KTS THROUGH THE AFTERNOON...OCCASIONAL GUSTS TO AROUND 20 KTS ALONG AND EAST OF I-35. WINDS DECREASING TO 5-10 KTS 22Z-00Z THEN BECOMING LGT/VRB OVERNIGHT. && .PREV DISCUSSION... /ISSUED 943 AM CST MON NOV 17 2014/ UPDATE... TO REMOVE FREEZE WARNING. DISCUSSION... TEMPERATURES HAVE WARMED BACK ABOVE FREEZING AND THE FREEZE WARNING HAS EXPIRED. SENDING NEW ZONES TO REMOVE THE FREEZE WARNING HEADLINE. PREV DISCUSSION... /ISSUED 534 AM CST MON NOV 17 2014/ AVIATION... /12Z TAF UPDATE/ MVFR CIGS CLEARED RAPIDLY OVER THE PAST SEVERAL HOURS...AND VFR SKIES ARE FORECAST FOR THE REST OF THE TAF PERIODS. SOME STRONG LOW LEVEL NORTHERLIES WILL ADD SOME GUST POTENTIAL FOR DRT THROUGH 16Z AND FOR THE I-35 TERMINAL SITES THROUGH 20Z. THE HIGHER GUSTS SHOULD BE GENERALLY AROUND 25 KNOTS. LIGHT WINDS ARE FORECAST BY THIS EVENING. PREV DISCUSSION... /ISSUED 422 AM CST MON NOV 17 2014/ SHORT TERM (TODAY THROUGH TUESDAY)... EARLY MORNING OBSERVATIONS REVEAL A STEADY FALL IN TEMPERATURES AS COLD AIR POURS INTO THE REGION AND LOW CLOUDS DECREASE. BASED ON THE LATEST OBSERVATIONS AND THE HRRR GUIDANCE...WE HAVE OPTED FOR A FREEZE WARNING FOR COUNTIES ALONG AND NEAR THE U.S. HIGHWAY 90 CORRIDOR. WELL BELOW NORMAL HIGH TEMPERATURES ARE EXPECTED ACROSS ALL OF SOUTH CENTRAL TEXAS TODAY AS SURFACE HIGH PRESSURE BUILDS. HIGHS WILL RANGE FROM THE UPPER 40S IN THE HILL COUNTRY TO THE LOWER 50S ALONG THE RIO GRANDE. WE EXPECT GUSTY NORTH WINDS TO CONTINUE THROUGH MID-AFTERNOON. WINDS WILL THEN DECREASE QUICKLY BY SUNSET AS THE PRESSURE GRADIENT RELAXES. TEMPERATURES WILL FALL BELOW FREEZING ACROSS THE VAST MAJORITY OF SOUTH CENTRAL TEXAS TONIGHT. LOWS IN THE 20S ARE EXPECTED FOR MOST AREAS TONIGHT. THE EXCEPTION WILL BE ALONG THE SOUTHERN RIO GRANDE PLAINS...WHERE LOWS MAY REMAIN CLOSER TO FREEZING. BELOW NORMAL HIGH TEMPERATURES ARE EXPECTED AGAIN ON TUESDAY WITH HIGHS IN THE 50S. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... A WARMING TREND IS EXPECTED THROUGH THE REMAINDER OF THE WORK WEEK AND UPCOMING WEEKEND AS SOUTHERLY FLOW IN THE LOW-LEVELS REMAINS INTACT. THERE IS SOME INDICATION IN THE MODELS WE COULD SEE A WEAK COLD FRONT MOVE INTO THE HILL COUNTRY ON FRIDAY. THIS FEATURE IS RATHER WEAK AND WOULD LIKELY NOT HAVE A SIGNIFICANT IMPACT ON TEMPERATURES. DRY WEATHER IS EXPECTED ON WEDNESDAY...WITH RAIN CHANCES RETURNING TO THE FORECAST ON THURSDAY FOR AREAS EAST OF I-35. RAIN CHANCES EXPAND WESTWARD FRIDAY AND SATURDAY AS AN UPPER LEVEL TROUGH APPROACHES FROM THE WEST. THIS UPPER LEVEL TROUGH WILL AID IN SENDING A PACIFIC COLD FRONT INTO THE REGION LATE SATURDAY INTO SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 50 27 53 36 61 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 51 23 53 32 60 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 53 27 54 35 61 / 0 0 0 0 0 BURNET MUNI AIRPORT 48 25 52 32 61 / 0 0 0 0 0 DEL RIO INTL AIRPORT 53 30 53 35 59 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 49 22 52 33 60 / 0 0 0 0 0 HONDO MUNI AIRPORT 52 24 52 34 55 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 52 26 53 33 59 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 50 27 52 34 60 / 0 0 - 0 10 SAN ANTONIO INTL AIRPORT 53 27 53 38 60 / 0 0 0 0 0 STINSON MUNI AIRPORT 53 30 54 37 59 / 0 0 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...76 PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
943 AM CST MON NOV 17 2014 .UPDATE... TO REMOVE FREEZE WARNING. && .DISCUSSION... TEMPERATURES HAVE WARMED BACK ABOVE FREEZING AND THE FREEZE WARNING HAS EXPIRED. SENDING NEW ZONES TO REMOVE THE FREEZE WARNING HEADLINE. && .PREV DISCUSSION... /ISSUED 534 AM CST MON NOV 17 2014/ AVIATION... /12Z TAF UPDATE/ MVFR CIGS CLEARED RAPIDLY OVER THE PAST SEVERAL HOURS...AND VFR SKIES ARE FORECAST FOR THE REST OF THE TAF PERIODS. SOME STRONG LOW LEVEL NORTHERLIES WILL ADD SOME GUST POTENTIAL FOR DRT THROUGH 16Z AND FOR THE I-35 TERMINAL SITES THROUGH 20Z. THE HIGHER GUSTS SHOULD BE GENERALLY AROUND 25 KNOTS. LIGHT WINDS ARE FORECAST BY THIS EVENING. PREV DISCUSSION... /ISSUED 422 AM CST MON NOV 17 2014/ SHORT TERM (TODAY THROUGH TUESDAY)... EARLY MORNING OBSERVATIONS REVEAL A STEADY FALL IN TEMPERATURES AS COLD AIR POURS INTO THE REGION AND LOW CLOUDS DECREASE. BASED ON THE LATEST OBSERVATIONS AND THE HRRR GUIDANCE...WE HAVE OPTED FOR A FREEZE WARNING FOR COUNTIES ALONG AND NEAR THE U.S. HIGHWAY 90 CORRIDOR. WELL BELOW NORMAL HIGH TEMPERATURES ARE EXPECTED ACROSS ALL OF SOUTH CENTRAL TEXAS TODAY AS SURFACE HIGH PRESSURE BUILDS. HIGHS WILL RANGE FROM THE UPPER 40S IN THE HILL COUNTRY TO THE LOWER 50S ALONG THE RIO GRANDE. WE EXPECT GUSTY NORTH WINDS TO CONTINUE THROUGH MID-AFTERNOON. WINDS WILL THEN DECREASE QUICKLY BY SUNSET AS THE PRESSURE GRADIENT RELAXES. TEMPERATURES WILL FALL BELOW FREEZING ACROSS THE VAST MAJORITY OF SOUTH CENTRAL TEXAS TONIGHT. LOWS IN THE 20S ARE EXPECTED FOR MOST AREAS TONIGHT. THE EXCEPTION WILL BE ALONG THE SOUTHERN RIO GRANDE PLAINS...WHERE LOWS MAY REMAIN CLOSER TO FREEZING. BELOW NORMAL HIGH TEMPERATURES ARE EXPECTED AGAIN ON TUESDAY WITH HIGHS IN THE 50S. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... A WARMING TREND IS EXPECTED THROUGH THE REMAINDER OF THE WORK WEEK AND UPCOMING WEEKEND AS SOUTHERLY FLOW IN THE LOW-LEVELS REMAINS INTACT. THERE IS SOME INDICATION IN THE MODELS WE COULD SEE A WEAK COLD FRONT MOVE INTO THE HILL COUNTRY ON FRIDAY. THIS FEATURE IS RATHER WEAK AND WOULD LIKELY NOT HAVE A SIGNIFICANT IMPACT ON TEMPERATURES. DRY WEATHER IS EXPECTED ON WEDNESDAY...WITH RAIN CHANCES RETURNING TO THE FORECAST ON THURSDAY FOR AREAS EAST OF I-35. RAIN CHANCES EXPAND WESTWARD FRIDAY AND SATURDAY AS AN UPPER LEVEL TROUGH APPROACHES FROM THE WEST. THIS UPPER LEVEL TROUGH WILL AID IN SENDING A PACIFIC COLD FRONT INTO THE REGION LATE SATURDAY INTO SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 50 27 53 36 61 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 51 23 53 32 60 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 53 27 54 35 61 / 0 0 0 0 0 BURNET MUNI AIRPORT 48 25 52 32 61 / 0 0 0 0 0 DEL RIO INTL AIRPORT 53 30 53 35 59 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 49 22 52 33 60 / 0 0 0 0 0 HONDO MUNI AIRPORT 52 24 52 34 55 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 52 26 53 33 59 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 50 27 52 34 60 / 0 0 - 0 10 SAN ANTONIO INTL AIRPORT 53 27 53 38 60 / 0 0 0 0 0 STINSON MUNI AIRPORT 53 30 54 37 59 / 0 0 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...76 SYNOPTIC/GRIDS...05 PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
534 AM CST MON NOV 17 2014 .AVIATION... /12Z TAF UPDATE/ MVFR CIGS CLEARED RAPIDLY OVER THE PAST SEVERAL HOURS...AND VFR SKIES ARE FORECAST FOR THE REST OF THE TAF PERIODS. SOME STRONG LOW LEVEL NORTHERLIES WILL ADD SOME GUST POTENTIAL FOR DRT THROUGH 16Z AND FOR THE I-35 TERMINAL SITES THROUGH 20Z. THE HIGHER GUSTS SHOULD BE GENERALLY AROUND 25 KNOTS. LIGHT WINDS ARE FORECAST BY THIS EVENING. && .PREV DISCUSSION... /ISSUED 422 AM CST MON NOV 17 2014/ SHORT TERM (TODAY THROUGH TUESDAY)... EARLY MORNING OBSERVATIONS REVEAL A STEADY FALL IN TEMPERATURES AS COLD AIR POURS INTO THE REGION AND LOW CLOUDS DECREASE. BASED ON THE LATEST OBSERVATIONS AND THE HRRR GUIDANCE...WE HAVE OPTED FOR A FREEZE WARNING FOR COUNTIES ALONG AND NEAR THE U.S. HIGHWAY 90 CORRIDOR. WELL BELOW NORMAL HIGH TEMPERATURES ARE EXPECTED ACROSS ALL OF SOUTH CENTRAL TEXAS TODAY AS SURFACE HIGH PRESSURE BUILDS. HIGHS WILL RANGE FROM THE UPPER 40S IN THE HILL COUNTRY TO THE LOWER 50S ALONG THE RIO GRANDE. WE EXPECT GUSTY NORTH WINDS TO CONTINUE THROUGH MID-AFTERNOON. WINDS WILL THEN DECREASE QUICKLY BY SUNSET AS THE PRESSURE GRADIENT RELAXES. TEMPERATURES WILL FALL BELOW FREEZING ACROSS THE VAST MAJORITY OF SOUTH CENTRAL TEXAS TONIGHT. LOWS IN THE 20S ARE EXPECTED FOR MOST AREAS TONIGHT. THE EXCEPTION WILL BE ALONG THE SOUTHERN RIO GRANDE PLAINS...WHERE LOWS MAY REMAIN CLOSER TO FREEZING. BELOW NORMAL HIGH TEMPERATURES ARE EXPECTED AGAIN ON TUESDAY WITH HIGHS IN THE 50S. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... A WARMING TREND IS EXPECTED THROUGH THE REMAINDER OF THE WORK WEEK AND UPCOMING WEEKEND AS SOUTHERLY FLOW IN THE LOW-LEVELS REMAINS INTACT. THERE IS SOME INDICATION IN THE MODELS WE COULD SEE A WEAK COLD FRONT MOVE INTO THE HILL COUNTRY ON FRIDAY. THIS FEATURE IS RATHER WEAK AND WOULD LIKELY NOT HAVE A SIGNIFICANT IMPACT ON TEMPERATURES. DRY WEATHER IS EXPECTED ON WEDNESDAY...WITH RAIN CHANCES RETURNING TO THE FORECAST ON THURSDAY FOR AREAS EAST OF I-35. RAIN CHANCES EXPAND WESTWARD FRIDAY AND SATURDAY AS AN UPPER LEVEL TROUGH APPROACHES FROM THE WEST. THIS UPPER LEVEL TROUGH WILL AID IN SENDING A PACIFIC COLD FRONT INTO THE REGION LATE SATURDAY INTO SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 50 27 53 36 61 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 51 23 53 32 60 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 53 27 54 35 61 / 0 0 0 0 0 BURNET MUNI AIRPORT 48 25 52 32 61 / 0 0 0 0 0 DEL RIO INTL AIRPORT 53 30 53 35 59 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 49 22 52 33 60 / 0 0 0 0 0 HONDO MUNI AIRPORT 52 24 52 34 55 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 52 26 53 33 59 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 50 27 52 34 60 / 0 0 - 0 10 SAN ANTONIO INTL AIRPORT 53 27 53 38 60 / 0 0 0 0 0 STINSON MUNI AIRPORT 53 30 54 37 59 / 0 0 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING COUNTIES: BEXAR...CALDWELL...COMAL...FAYETTE...GONZALES... GUADALUPE...KINNEY...MEDINA...UVALDE...VAL VERDE...WILSON. && $$ MESOSCALE/AVIATION...18 SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
527 AM CST MON NOV 17 2014 .AVIATION... VFR AND SKC WITH LIGHT WINDS THRU 18/12Z. && .PREV DISCUSSION... /ISSUED 412 AM CST MON NOV 17 2014/ SHORT TERM... DEEP AND DRY NORTHERLY FLOW OCCUPIED THE ENTIRE EXTENT OF THE GREAT PLAINS THIS MORNING AND THIS THEME WILL REMAIN INTACT THROUGH TONIGHT. A BROAD MERIDIONAL SURFACE RIDGE ANCHORED IN THE LEE OF THE ROCKIES WILL SHIFT SLOWLY EAST TODAY AND BE LOCATED OFF THE CAPROCK BY THE AFTERNOON AHEAD OF MILDER SW BREEZES. SNOWPACK COLOR CURVE ON IR IMAGERY SHOWS THAT THE NAM AND RUC INITIALIZED THE SNOW COVER RATHER WELL ACROSS OUR NORTHERN TWO ROWS OF COUNTIES...SO WITH THIS IN MIND WE HAVE SCALED BACK MAX TEMPS IN THESE AREAS AS 1 TO 3 INCHES OF SNOW WILL CERTAINLY STUNT RADIATIONAL WARMING...ESPECIALLY AFTER SOME BITTER LOWS TO START THE DAY. AWAY FROM THE SNOW COVER... WENT WITH THE MILD MET NUMBERS AS THESE DRY AIRMASSES OFTEN WARM SURPRISINGLY FAST UNDER FULL SUN WITH DOWNSLOPING WINDS. STEADY SW WINDS AREA WIDE TONIGHT WILL MAKE FOR MILDER LOWS...HOWEVER EVEN THESE ARE STILL 10 TO 20 DEGREES BELOW CLIMO. LONG TERM... PROGRESSIVE PATTERN WILL DEVELOP THIS WEEK WITH A WEAK SHORTWAVE MOVING OVER THE REGION TOMORROW. THIS WAVE WILL BRING LITTLE IN THE WAY OF SENSIBLE WEATHER CHANGES. A BIT STRONGER SHORTWAVE WILL MOVE OVER THE AREA DURING THE DAY THURSDAY WHICH THE MODELS HAVE SLIGHT TIMING AND STRENGTH DIFFERENCES. AHEAD OF THIS SHORTWAVE TROUGH...LOW LEVEL MOISTURE WILL TRY TO STREAM NORTHWARD AND SOME BOUNDARY LAYER MOISTURE MAY MANAGE TO MAKE IT INTO THE ROLLING PLAINS. INCREASED HIGH CLOUDS WITH THIS WAVE ALONG WITH THE INCREASED MOISTURE MAY LIMIT THE AMOUNT OF WARMING THAT WILL TAKE PLACE. WITH THE BEST MOISTURE RETURN TAKING PLACE EAST OF THE FORECAST AREA...RAIN CHANCES LOOK TO STAY TOO FAR TO THE EAST OF US TO PUT ANY MENTION IN THE FORECAST. AS THIS WAVE PASSES BY...A WEAK COLD FRONT WILL MOVE ACROSS THE AREA BUT ONLY DROP TEMPS BY A FEW DEGREES. A MUCH STRONGER WAVE IS FORECAST TO MOVE OVER THE REGION DURING THE DAY SATURDAY. MODELS ARE STILL STRUGGLING WITH HOW STRONG THIS WAVE WILL BE. REGARDLESS...BOUNDARY LAYER MOISTURE CREEPS INTO THE ROLLING PLAINS AND ONTO THE CAPROCK BY SATURDAY AFTERNOON. IF THE CURRENT SOLUTIONS HOLD TRUE...WE MAY SEE SOME SHOWER/THUNDERSTORM ACTIVITY ACROSS THE REGION. DID NOT FEEL CONFIDENT ENOUGH TO GO WITH LOW- END CHANCE AT THIS TIME BUT DID BRING SLIGHT CHANCE POPS ACROSS ALL BUT THE NORTHWESTERN SOUTH PLAINS. JORDAN && .PRELIMINARY POINT TEMPS/POPS... FRIONA 34 14 46 24 49 / 0 0 0 0 0 TULIA 35 16 47 26 50 / 0 0 0 0 0 PLAINVIEW 37 18 48 26 51 / 0 0 0 0 0 LEVELLAND 39 20 49 27 52 / 0 0 0 0 0 LUBBOCK 40 19 48 28 52 / 0 0 0 0 0 DENVER CITY 39 21 50 27 54 / 0 0 0 0 0 BROWNFIELD 40 21 50 28 53 / 0 0 0 0 0 CHILDRESS 37 20 50 29 54 / 0 0 0 0 0 SPUR 41 22 49 31 54 / 0 0 0 0 0 ASPERMONT 42 22 51 32 57 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 93
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
422 AM CST MON NOV 17 2014 .SHORT TERM (TODAY THROUGH TUESDAY)... EARLY MORNING OBSERVATIONS REVEAL A STEADY FALL IN TEMPERATURES AS COLD AIR POURS INTO THE REGION AND LOW CLOUDS DECREASE. BASED ON THE LATEST OBSERVATIONS AND THE HRRR GUIDANCE...WE HAVE OPTED FOR A FREEZE WARNING FOR COUNTIES ALONG AND NEAR THE U.S. HIGHWAY 90 CORRIDOR. WELL BELOW NORMAL HIGH TEMPERATURES ARE EXPECTED ACROSS ALL OF SOUTH CENTRAL TEXAS TODAY AS SURFACE HIGH PRESSURE BUILDS. HIGHS WILL RANGE FROM THE UPPER 40S IN THE HILL COUNTRY TO THE LOWER 50S ALONG THE RIO GRANDE. WE EXPECT GUSTY NORTH WINDS TO CONTINUE THROUGH MID-AFTERNOON. WINDS WILL THEN DECREASE QUICKLY BY SUNSET AS THE PRESSURE GRADIENT RELAXES. TEMPERATURES WILL FALL BELOW FREEZING ACROSS THE VAST MAJORITY OF SOUTH CENTRAL TEXAS TONIGHT. LOWS IN THE 20S ARE EXPECTED FOR MOST AREAS TONIGHT. THE EXCEPTION WILL BE ALONG THE SOUTHERN RIO GRANDE PLAINS...WHERE LOWS MAY REMAIN CLOSER TO FREEZING. BELOW NORMAL HIGH TEMPERATURES ARE EXPECTED AGAIN ON TUESDAY WITH HIGHS IN THE 50S. && .LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... A WARMING TREND IS EXPECTED THROUGH THE REMAINDER OF THE WORK WEEK AND UPCOMING WEEKEND AS SOUTHERLY FLOW IN THE LOW-LEVELS REMAINS INTACT. THERE IS SOME INDICATION IN THE MODELS WE COULD SEE A WEAK COLD FRONT MOVE INTO THE HILL COUNTRY ON FRIDAY. THIS FEATURE IS RATHER WEAK AND WOULD LIKELY NOT HAVE A SIGNIFICANT IMPACT ON TEMPERATURES. DRY WEATHER IS EXPECTED ON WEDNESDAY...WITH RAIN CHANCES RETURNING TO THE FORECAST ON THURSDAY FOR AREAS EAST OF I-35. RAIN CHANCES EXPAND WESTWARD FRIDAY AND SATURDAY AS AN UPPER LEVEL TROUGH APPROACHES FROM THE WEST. THIS UPPER LEVEL TROUGH WILL AID IN SENDING A PACIFIC COLD FRONT INTO THE REGION LATE SATURDAY INTO SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 50 27 53 36 61 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 51 23 53 32 60 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 53 27 54 35 61 / 0 0 0 0 0 BURNET MUNI AIRPORT 48 25 52 32 61 / 0 0 0 0 0 DEL RIO INTL AIRPORT 53 30 53 35 59 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 49 22 52 33 60 / 0 0 0 0 0 HONDO MUNI AIRPORT 52 24 52 34 55 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 52 26 53 33 59 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 50 27 52 34 60 / 0 0 - 0 10 SAN ANTONIO INTL AIRPORT 53 27 53 38 60 / 0 0 0 0 0 STINSON MUNI AIRPORT 53 30 54 37 59 / 0 0 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING COUNTIES: BEXAR...CALDWELL...COMAL...FAYETTE...GONZALES... GUADALUPE...KINNEY...MEDINA...UVALDE...VAL VERDE...WILSON. && $$ MESOSCALE/AVIATION...18 SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
412 AM CST MON NOV 17 2014 .SHORT TERM... DEEP AND DRY NORTHERLY FLOW OCCUPIED THE ENTIRE EXTENT OF THE GREAT PLAINS THIS MORNING AND THIS THEME WILL REMAIN INTACT THROUGH TONIGHT. A BROAD MERIDIONAL SURFACE RIDGE ANCHORED IN THE LEE OF THE ROCKIES WILL SHIFT SLOWLY EAST TODAY AND BE LOCATED OFF THE CAPROCK BY THE AFTERNOON AHEAD OF MILDER SW BREEZES. SNOWPACK COLOR CURVE ON IR IMAGERY SHOWS THAT THE NAM AND RUC INITIALIZED THE SNOW COVER RATHER WELL ACROSS OUR NORTHERN TWO ROWS OF COUNTIES...SO WITH THIS IN MIND WE HAVE SCALED BACK MAX TEMPS IN THESE AREAS AS 1 TO 3 INCHES OF SNOW WILL CERTAINLY STUNT RADIATIONAL WARMING...ESPECIALLY AFTER SOME BITTER LOWS TO START THE DAY. AWAY FROM THE SNOW COVER... WENT WITH THE MILD MET NUMBERS AS THESE DRY AIRMASSES OFTEN WARM SURPRISINGLY FAST UNDER FULL SUN WITH DOWNSLOPING WINDS. STEADY SW WINDS AREA WIDE TONIGHT WILL MAKE FOR MILDER LOWS...HOWEVER EVEN THESE ARE STILL 10 TO 20 DEGREES BELOW CLIMO. && .LONG TERM... PROGRESSIVE PATTERN WILL DEVELOP THIS WEEK WITH A WEAK SHORTWAVE MOVING OVER THE REGION TOMORROW. THIS WAVE WILL BRING LITTLE IN THE WAY OF SENSIBLE WEATHER CHANGES. A BIT STRONGER SHORTWAVE WILL MOVE OVER THE AREA DURING THE DAY THURSDAY WHICH THE MODELS HAVE SLIGHT TIMING AND STRENGTH DIFFERENCES. AHEAD OF THIS SHORTWAVE TROUGH...LOW LEVEL MOISTURE WILL TRY TO STREAM NORTHWARD AND SOME BOUNDARY LAYER MOISTURE MAY MANAGE TO MAKE IT INTO THE ROLLING PLAINS. INCREASED HIGH CLOUDS WITH THIS WAVE ALONG WITH THE INCREASED MOISTURE MAY LIMIT THE AMOUNT OF WARMING THAT WILL TAKE PLACE. WITH THE BEST MOISTURE RETURN TAKING PLACE EAST OF THE FORECAST AREA...RAIN CHANCES LOOK TO STAY TOO FAR TO THE EAST OF US TO PUT ANY MENTION IN THE FORECAST. AS THIS WAVE PASSES BY...A WEAK COLD FRONT WILL MOVE ACROSS THE AREA BUT ONLY DROP TEMPS BY A FEW DEGREES. A MUCH STRONGER WAVE IS FORECAST TO MOVE OVER THE REGION DURING THE DAY SATURDAY. MODELS ARE STILL STRUGGLING WITH HOW STRONG THIS WAVE WILL BE. REGARDLESS...BOUNDARY LAYER MOISTURE CREEPS INTO THE ROLLING PLAINS AND ONTO THE CAPROCK BY SATURDAY AFTERNOON. IF THE CURRENT SOLUTIONS HOLD TRUE...WE MAY SEE SOME SHOWER/THUNDERSTORM ACTIVITY ACROSS THE REGION. DID NOT FEEL CONFIDENT ENOUGH TO GO WITH LOW- END CHANCE AT THIS TIME BUT DID BRING SLIGHT CHANCE POPS ACROSS ALL BUT THE NORTHWESTERN SOUTH PLAINS. JORDAN && .PRELIMINARY POINT TEMPS/POPS... FRIONA 34 14 46 24 49 / 0 0 0 0 0 TULIA 35 16 47 26 50 / 0 0 0 0 0 PLAINVIEW 37 18 48 26 51 / 0 0 0 0 0 LEVELLAND 39 20 49 27 52 / 0 0 0 0 0 LUBBOCK 40 19 48 28 52 / 0 0 0 0 0 DENVER CITY 39 21 50 27 54 / 0 0 0 0 0 BROWNFIELD 40 21 50 28 53 / 0 0 0 0 0 CHILDRESS 37 20 50 29 54 / 0 0 0 0 0 SPUR 41 22 49 31 54 / 0 0 0 0 0 ASPERMONT 42 22 51 32 57 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 93/14
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1128 PM CST SUN NOV 16 2014 .AVIATION... /06Z TAFS/ GUSTY NORTHERLY WINDS UP TO 25 KNOTS WILL PERSIST OVERNIGHT ACROSS SOUTH CENTRAL TEXAS. MVFR CONDITIONS WILL LINGER AROUND TO ABOUT 09Z MONDAY MAINLY ALONG THE I-35 CORRIDOR SITES. ACROSS KDRT... VFR CONDITIONS ARE ANTICIPATED FOR THE ENTIRE FORECAST CYCLE. CIGS WILL LIFT TO VFR EARLY MONDAY MORNING AND CONTINUE THAT WAY FOR THE REMAINDER OF THE FORECAST PERIOD. BREEZY NORTHERLY WINDS WILL REMAIN THROUGH MONDAY EVENING. && .PREV DISCUSSION... /ISSUED 751 PM CST SUN NOV 16 2014/ UPDATE... THE COLD FRONT IS NOW LOCATED ACROSS OUR SOUTHERN COUNTIES. MUCH COLDER WEATHER IS MOVING IN BEHIND THE BOUNDARY AND AT 8 PM THE FREEZING LINE WAS JUST ENTERING OUR NORTHERN COUNTIES NEAR EDWARDS AND KERR COUNTY. A LARGE AREA OF VERY LIGHT PRECIPITATION REMAINS CONFINED TO AREAS NORTH OF OUR CWA AND THIS SHOULD CONTINUE TO BE THE CASE FOR MOST OF THE NIGHT. THIS AFTERNOON THE HRRR HAD BEEN SHOWING A BAND OF PRECIP PUSHING THROUGH SOUTH-CENTRAL TEXAS BUT HAS SINCE BACKED OFF. THE BEST CHANCES FOR WINTER PRECIP TONIGHT WILL BE IN THE NORTHERN HILL COUNTRY...NEAR LLANO AND BURNET COUNTY THROUGH MIDNIGHT. CURRENTLY...A BAND OF SNOWFALL EXTENDS SOUTH NEAR ELDORADO AND WITH A CONTINUED EASTWARD MOVEMENT THIS WOULD QUICKLY CLIP LLANO AND BURNET COUNTIES. THE QUESTION THEN TURNS INTO WHAT THE PRECIPITATION TYPE WOULD BE. ALL MODEL FORECAST SOUNDINGS SHOW A WARM LAYER AROUND 750 MB THAT WOULD LIKELY PREVENT SNOW THIS FAR SOUTH. HOWEVER...A FAIRLY DEEP SUB- FREEZING LAYER BELOW 800 WOULD LEAD TO A SLEET/RAIN MIX OR ALL SLEET. IF MODELS ARE OVERDOING THIS WARM LAYER...THEN BRIEF SNOW WOULD BE POSSIBLE. AM NOT EXPECTING ACTIVITY TO BE HEAVY OR LAST FOR A VERY LONG TIME SO THERE SHOULD NOT BE MANY IMPACTS. SINCE IT WILL BE SUCH A SHORT-TERM TYPE EVENT WILL MOST LIKELY HANDLE ANY IMPACTS WITH AN SPS LATER THIS EVENING IF NEEDED. MODEL SOUNDINGS SHOW A LOT OF DRYING IN THE LOW-LEVELS AFTER 6Z AND MUCH OF THE PRECIP SHOULD SHUT OFF. THE HRRR IS SHOWING THIS WELL. HAMPSHIRE PREV DISCUSSION... /ISSUED 507 PM CST SUN NOV 16 2014/ AVIATION... A COLD FRONT IS PUSHING ACROSS THE AREA LATE THIS AFTERNOON. THE COLD FRONT IS LOCATED SOUTH OF HIGHWAY 90 ACROSS OUR SOUTHERN COUNTIES AND EXPECTED TO PUSH AWAY FROM OUR AREA EARLY THIS EVENING. IN THE WAKE OF THE FROPA...BREEZY NORTHERLY WINDS WILL PREVAIL FOR MOST OF TONIGHT. ALSO...GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE THROUGH ABOUT MIDNIGHT TONIGHT. CIGS AND VSBYS WILL IMPROVE TO MVFR THIS EVENING AND THEN BECOMING VFR OVERNIGHT/EARLY MONDAY. CLEARING IS FORECAST ACROSS AREA SITES MONDAY MORNING WITH NORTHERLY WINDS OF 8 TO 12 KNOTS. PREV DISCUSSION... /ISSUED 330 PM CST SUN NOV 16 2014/ SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)... UPPER AIR ANALYSIS THIS MORNING SHOWED A TROUGH SWINGING THROUGH THE SOUTHWEST WITH SOUTHWESTERN FLOW ACROSS TEXAS. AT THE SURFACE A COLD FRONT WAS ENTERING OUR CWA THIS AFTERNOON. IT STRETCHED FROM WACO TO JUNCTION TO LANGTRY. THERE HAS ONLY BEEN ISOLATED LIGHT RAIN WITH THE FRONT AND THE MAIN CHANGE IS THE STRONG NORTH WINDS. THERE WAS MORE WIDESPREAD PRECIP ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO WEST TEXAS. THESE FEATURE WILL MOVE TOWARD OUR FORECAST AREA LATER TONIGHT AND MODELS SUGGEST THAT WE WILL BE ON THE SOUTHERN EDGE OF IT. WE WILL HAVE SLIGHT TO LOW END CHANCE POPS THIS EVENING ACROSS OUR EASTERN COUNTIES. WITHIN THIS AREA THERE WILL A CHANCE FOR SOME WINTER PRECIP IN PARTS OF BURNET AND WILLIAMSON COUNTIES. IT LOOKS LIKE THE MOST LIKELY SCENARIO IS FOR A MIX OF RAIN AND SLEET AND THE BEST TIME WILL BE BETWEEN ABOUT 9PM AND MIDNIGHT. PRECIP AMOUNTS SHOULD BE LIGHT AND WITH THE GROUND SO WARM WE DO NOT EXPECT ANY WINTER PRECIP TO HAVE ANY IMPACTS TONIGHT. AFTER MIDNIGHT PRECIP CHANCES WILL SHIFT TO THE SOUTH WHERE TEMPERATURES WILL STAY ABOVE FREEZING SO WE ONLY HAVE RAIN IN THE FORECAST. MORNING LOW TEMPERATURES WILL DROP TO OR BELOW FREEZING ACROSS THE HILL COUNTRY AND EDWARDS PLATEAU. MONDAY THE FRONT WILL MOVE AWAY AND THE UPPER TROUGH WILL SWING THROUGH THE REGION. EXPECT SKIES TO CLEAR THROUGH THE DAY. CLEAR SKIES AND LIGHT WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING MONDAY NIGHT AND A WIDESPREAD FREEZE. EXPECT THAT A FREEZE WARNING WILL BE NEEDED FOR THE PARTS OF THE CWA THAT HAVE NOT YET HAD A FREEZE. LONG TERM (TUESDAY THROUGH SUNDAY)... THE UPPER PATTERN WILL BECOME MORE ZONAL INTO THE MIDDLE OF THE WEEK AS THE LOW LEVEL FLOW TURNS BACK TO THE SOUTHEAST. THIS WILL LEAD TO A WARMING TREND INTO THURSDAY. BY THURSDAY AN OVER RUNNING PATTERN WILL BECOME ESTABLISHED ACROSS THE EASTERN HALF OF THE AREA. THERE WILL BE SLIGHT TO LOW END CHANCE POPS STARTING THURSDAY AND CONTINUING THROUGH THE END OF THE PERIOD. THIS SEEMS LIKE TOO LONG A PERIOD FOR RAIN EVEN THOUGH CHANCES WILL BE LOW. TIME FRAME SHOULD COME INTO BETTER FOCUS AS WE GET CLOSER. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 33 50 29 53 36 / 20 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 33 51 24 53 32 / 20 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 33 53 28 54 35 / 20 0 0 0 10 BURNET MUNI AIRPORT 29 48 27 52 32 / 20 0 0 0 0 DEL RIO INTL AIRPORT 34 53 31 53 35 / 10 0 0 0 0 GEORGETOWN MUNI AIRPORT 31 49 25 52 33 / 20 0 0 0 0 HONDO MUNI AIRPORT 32 52 25 52 34 / 10 0 0 0 10 SAN MARCOS MUNI AIRPORT 33 52 26 53 33 / 20 0 0 0 10 LA GRANGE - FAYETTE REGIONAL 34 50 27 52 34 / 30 0 - - 10 SAN ANTONIO INTL AIRPORT 35 53 29 53 38 / 10 0 0 0 10 STINSON MUNI AIRPORT 36 53 29 54 37 / 10 0 0 0 10 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...17 SYNOPTIC/GRIDS...29
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1238 PM EST MON NOV 17 2014 .SYNOPSIS... A STRONG COLD FRONT SWINGS ACROSS THE AREA TODAY. ARCTIC AIR WILL FOLLOW TONIGHT WITH HIGH PRESSURE MOVING INTO THE MID MISSISSIPPI VALLEY. EXPECT A PERIOD OF SNOW SHOWERS...WINDS AND COLD WIND CHILLS LATE TONIGHT INTO TUESDAY MORNING AS A RESULT. HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1040 AM EST MONDAY... BASED ON LATEST SURFACE OBSERVATIONS... THE COLD FRONT APPEARS TO BE MOVING A COUPLE HOURS AHEAD OF THE PREVIOUS FORECAST. THIS IS REFLECTED IN THE FORECAST WITH REDUCED TEMPERATURES AND EARLIER ONSET OF SNOW IN THE WESTERN SLOPES. SNOW IS NOW FORECAST TO BEGIN AROUND 3PM FOR WESTERN GREENBRIER COUNTRY. PREVIOUS DISCUSSION... EARLIER RUN OF THE HRRR HAD A GREAT HANDLE ON THE RAIN MOVING IN FROM THE SOUTHWEST. FOLLOWED ITS SOLUTION THROUGH THE MORNING...BLENDING IN THE 00Z GFS/NAM. LOOKS LIKE A SLAM DUNK FOR EVERYONE SEEING RAIN TODAY...THOUGH AMOUNTS MAY BE LESS THAN EARLIER THOUGHT AS DID NOT SEE AS MUCH FALL SUNDAY. STILL A GOOD ONE HALF TO THREE QUARTERS OF AN INCH WILL OCCUR TODAY. THIS FRONT LOCATED ACROSS THE CENTRAL APPALACHIANS SOUTHWEST INTO ALABAMA WILL SLIDE EAST ACROSS THE AREA TODAY...WITH A COUPLE WAVES OF LOW PRESSURE ALONG IT. THE MAIN FORECAST ISSUE WILL BE THE COLDER AIR ARRIVING BEHIND THE FRONT. THE 00Z NAM DEPICTED THE COLDER AIR BETTER AT 06Z AT 8H THAN THE GFS/ECMWF...SO LEANED TOWARD IT TEMP FORECAST. SHOULD SEE DEEP MOISTURE EDGE EAST EARLY THIS AFTERNOON IN THE MTNS WHILE THE COLDER AIR STARTS TURNING RESIDUAL SHOWERS OVER TO SNOW LATER IN THE AFTERNOON. BY DUSK MOST OF THE EASTERN HALF OF THE CWA WILL BE DRYING OUT AS WINDS TURN WNW. TEMPS DESPITE THE RAIN...OR REALLY AS A RESULT OF THE RAIN BRINGING DOWN THE WARMER TEMPS ALOFT MAY BRING READINGS INTO THE 50S BEFORE THE COLD AIR ARRIVES IN THE PIEDMONT THIS AFTERNOON. IN THE MTNS HIGHS SHOULD BE OCCURRING BY MIDDAY THEN DROPPING IN THE LATE AFTERNOON. FORECAST SOUNDINGS IN THE MTNS SHOW MOISTURE BECOMING SHALLOW FAST...WITH THE FAVORABLE SNOW GROWTH TEMPS ALOFT NOT BEING REALIZED UNTIL LATE EVENING...SO COULD BE SOME PATCHY FREEZING DRIZZLE ISSUES...AND WILL ADVERTISE THIS IN THE MTNS OF THE FAR WEST THIS EVENING. THIS HERE LIES THE PROBLEM...WHERE IT RAINS...COMBINED WITH ARCTIC AIR ARRIVING AND SNIZZLE(SNOW AND FREEZING DRIZZLE) FOLLOWING...ROADS WILL BECOME SLICK IN THE HIGHER ELEVATIONS BY LATE DUSK. AFTER COLLABORATING WITH NEIGHBORING OFFICES...IT WAS DECIDED TO GO WITH A WINTER WX ADVISORY FOR THE NC MTNS INTO THE GRAYSON HIGHLANDS...BUT TO DELAY ANY HEADLINES...IF THEY ARE NEEDED FURTHER NORTH INTO THE MTN EMPIRE OF SW VA AND SE WV MTNS. STILL THINK THE TEMPS FALLING FAST LATE TONIGHT MAY REQUIRE AT LEAST A SPECIAL WX STATEMENT. THE SNOWFALL ACCUMULATION WILL BE LIGHT GIVEN THE LIMITED MOISTURE BUT 1 TO 3 INCHES IN THE WESTERN SLOPES ARE POSSIBLE INTO TUESDAY MORNING. IN ADDITION...THE WINDS WILL BE GUSTING OVER 40 MPH WITH 6 HR PRESSURE RISES OF 5-7MB EXPECTED BEHIND THE FRONT THIS EVENING INTO TUESDAY MORNING. THIS WAS ADDED TO THE WINTER WX ADVISORY IN THE NC MTNS. CLOUDS MAY PREVENT IDEAL MIXING OF THE STRONGER WINDS ALOFT...BUT WHERE IT THE CLOUD/CLEARING LINE IS ALONG/NEAR THE BLUE RIDGE...THINK AN OCCASIONAL 50 MPH GUST WILL BE REALIZED. OUTSIDE THE WINTER WX ADVISORY FOR ELEVATIONS ABOVE 3000 FT...HIGHLIGHT WEATHER IN THE HAZARDOUS WEATHER OUTLOOK. WILL TAKE A LOOK AT MORE DATA COMING IN AND FURTHER COORDINATING WITH OTHER WFO OFFICES TO SEE IF MORE HEADLINES ARE NEEDED. FOR TONIGHT...TEMPS WILL DROP INTO THE TEENS MOUNTAINS...SOME SINGLE DIGITS HIGHEST ELEVATIONS...WITH 20S IN THE EAST. WIND CHILLS BY DAWN TUESDAY WILL RANGE FROM 5 ABOVE TO 5 BELOW IN THE MOUNTAINS...TO THE TEENS IN THE EAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 315 AM EST MONDAY... COLD FRONT PUSHES OUT INTO THE ATLANTIC OCEAN TUESDAY AS THE 1033 SURFACE HIGH PRESSURE IN TEXAS BUILDS NORTHWARD INTO OUR REGION. THE AXIS OF THE UPPER TROF CROSS OUR AREA TUESDAY INTO TUESDAY NIGHT. GUSTY NORTHWEST WINDS WILL CONTINUE TUESDAY AS A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE REGION THROUGH TUESDAY. THE GFS...NAM AND HIRESW-ARW SHOWED UPSLOPE SNOW SHOWERS AND SNOW FLURRIES CONTINUE IN THE WESTERN MOUNTAINS. ADDITIONAL LIGHT ACCUMULATIONS MAY BE POSSIBLE IN THE NORTHWEST UPSLOPE FAVORED LOCATIONS. HIGH TEMPERATURES TUESDAY WILL RANGE FROM THE UPPER TEENS IN THE NORTHWEST MOUNTAINS TO THE MID 30S IN THE PIEDMONT. HIGH PRESSURE CONTINUES TRAVEL EASTWARD TUESDAY NIGHT. TUESDAY NIGHT WILL BE A VERY COLD NIGHT WITH TEMPERATURES ACROSS THE AREA RANGING FROM THE SINGLE DIGITS IN THE HIGHER ELEVATIONS TO THE UPPER TEENS ACROSS THE PIEDMONT. WINDS WILL DECREASE TUESDAY NIGHT...BUT WIND CHILLS WILL BE COLD WITH SINGLE DIGITS IN THE WEST TO TEENS IN THE EAST. A WARM FRONT WILL PASS OVER THE REGION WEDNESDAY...AS A COLD FRONT DROPS SOUTH INTO THE OHIO VALLEY. WEDNESDAY AFTERNOON HIGH TEMPERATURES WILL AVERAGE 20F COLDER THAN NORMAL WITH READINGS FROM THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE PIEDMONT. COLD FRONT APPROACHES FROM THE WEST WEDNESDAY NIGHT. ALLOWED FOR ISOLATED SNOW SHOWERS ACROSS THE NORTH. LOW TEMPERATURES WEDNESDAY NIGHT WILL GENERALLY BE FROM AROUND 20 DEGREES TO THE MID 20S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 400 PM EST SUNDAY... SURGE OF ARCTIC AIR TO INVADE THE REGION INTO THURSDAY. THIS WAS NOT ADVERTISED A FEW RUNS BACK...BUT GIVEN GENERAL CONSENSUS AMONG THE MODELS AND A PREVAILING MEAN DEEP MERIDIONAL TROUGH ACROSS THE EASTERN HALF OF THE U.S...THIS APPEARS TO BE A REASONABLE SOLUTION AND THUS WILL LEAN IN THIS DIRECTION. HOWEVER...IN TERMS OF INTENSITY...THIS FINAL ARCTIC SURGE WILL NOT EVEN COME CLOSE TO THE ONE EARLIER IN THE WEEK. MOISTURE IS LIMITED...BUT SLIGHT CHC TO LOW CHC POPS FOR UPSLOPE -SHSN ACROSS THE USUAL WESTERN UPSLOPE AREAS OF THE ALLEGHANYS SEEMS REASONABLE AND HAVE BEEN INCLUDED...WITH NO MENTION OF POPS EAST OF THE ALLEGHANY FRONT. THE PARENT ARCTIC HIGH WILL SETTLE OVER THE REGION EARLY SATURDAY...SO BELOW NORMAL TEMPERATURES SHOULD REMAIN IN PLACE THROUGH SAT MORNING. MODEL TEMPS IN REASONABLE AGREEMENT THROUGH FRI...BUT FEEL THE GFS MOS IS TOO QUICK TO SPREAD WARMER RETURN FLOW INTO THE REGION SAT...SO LEANED TOWARD THE COLDER ECMWF MOS. BIGGER QUESTIONS REMAIN FOR THE REMAINDER OF THE EXTENDED PERIODS. AS THE ARCTIC HIGH RETREATS TOWARD THE COAST SAT...THE LONG AWAITED RETURN TO A LESS AMPLIFIED FLOW PATTERN BEGINS TO EVOLVE. THE EASTERN U.S. TROUGH IS REPLACED BY A SHORT WAVE RIDGE AS BROAD MEAN TROUGHING RELOCATES TO THE WESTERN/CENTRAL U.S. THE MAIN CONCERN FOR THE WEEKEND IS THE TIMING AND ASSOCIATED WARMING/MOISTENING WITH A STRONG NEGATIVELY TITLED HIGHLY PROGRESSIVE SHORT WAVE PROGGED TO EJECT OUT OF THE BASE OF THE MEAN TROUGH INTO THE SOUTHEAST STATES SAT NIGHT-SUN. 12Z ECMWF IN EXCELLENT AGREEMENT WITH 12Z GFS IN BRINGING THIS SYSTEM THROUGH OUR REGION SUN AFTERNOON. SUPERBLEND POPS WERE LIKELY TO CATEGORICAL SUN NIGHT-MON. GIVEN THE ASSOCIATED PVA...AND AMOUNT OF MOIST/WARM ADVECTION INTO THE REGION...THIS SEEMED REASONABLE. HOWEVER...NEIGHBORING OFFICES WERE NOT ON BOARD WITH THESE HIGH VALUES THIS FAR OUT...SO STOPPED AT A MORE REASONABLE 50 PERCENT VALUE FOR NOW. GIVEN RECENT MODEL RUN-TO-RUN VARIATION...THAT SEEMED REASONABLE FOR SURE. A SIGNIFICANT WARM UP WILL ENSUE SAT- SUN...BUT AS NOTED ABOVE...PERHAPS NOT TO THE DEGREE ADVERTISED BY THE MEX MOS. THUS...HAVE USED A MODEL BLEND FOR SAT- SUN. AN EVEN MORE SIGNIFICANT NEGATIVELY TILTED UPPER TROUGH APPEARS ON TRACK FOR THE REGION INTO MON. ECMWF/GFS SHOWING SOME INCREDIBLY WARM/MOIST AIR FOR THIS TIME OF YEAR SPREADING INTO THE REGION FROM THE SOUTH BY MON MORNING ON THE HEELS A STRONG LOW-LEVEL SOUTHERLY JET WITH DEWPOINTS APPROACHING 60 DEGREES BY MON AFTERNOON ACROSS THE PIEDMONT AND SOUTHSIDE. PROGGED LIFTED INDICES AND CAPES ALONG WITH EVIDENT SHEAR SUGGEST SOME -TSRA MAY NEED TO BE CONSIDERED BY MON AFTERNOON ACROSS THE PIEDMONT. TO SAY THE LEAST...EARLY NEXT WEEK WILL BE IN SHARP CONTRAST TO THE WEATHER EXPECTED THIS WEEK WITH TEMPERATURES ACTUALLY ABOVE SEASONAL NORMALS...ESPECIALLY IF LOWS ARE ONLY IN THE 50S MON MORNING WITH HIGHS IN THE 60S. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 640 AM EST MONDAY... HEAVY RAIN AXIS SHIFTS EAST EARLY THIS AFTERNOON. THE COLD FRONT/WIND SHIFT IS EXPECTED ACROSS WESTERN SLOPES (BLF/LWB) BY 19Z...ALONG THE BLUE RIDGE (BCB/ROA) AROUND 20Z-22Z...AND THE PIEDMONT (LYH/DAN) BY 00Z THIS EVENING. VISIBILITIES/CEILINGS WILL IMPROVE SOME THROUGH THE DAY AND CONTINUE TO IMPROVE FOR AREAS EAST OF THE BLUE RIDGE (ROA/LYH/DAN). ACROSS THE MOUNTAINS MVFR VISIBILITIES/CEILING FOR MOST AREAS...WESTERN SLOPES IFR WITH SNOW THROUGH EARLY MORNING. PRESSURE RISES BEHIND THE FRONT WILL BRING WINDY/GUSTY CONDITIONS TO THE AREA. STRONGER WINDS WILL BE OVER THE MOUNTAINS THROUGH TONIGHT...THEN AS INVERSION LOWERS ALL SITES WILL HAVE GUSTY CONDITIONS THROUGH THE DAY TUESDAY. ARCTIC BLAST OF AIR MAY LEAD TO WATER FREEZING ON RUNWAYS/AIRPLANES THIS EVENING...THOUGH WINDS MAY LEAD TO QUICKER EVAPORATION OF THE WET SFCS. EXTENDED DISCUSSION... EXPECT MAINLY VFR WEATHER TUESDAY NIGHT-THURSDAY. NEXT SYSTEM APPEARS TO ARRIVE FRIDAY WITH MVFR CIGS IN THE MTNS. && .CLIMATE... AS OF 315 PM EST SUNDAY... RECORD COOLEST HIGHS...TUESDAY NOV 18TH BLACKSBURG VA...30 IN 2008 BLUEFIELD WV....27 IN 2008 DANVILLE VA.....38 IN 1959 ROANOKE VA......33 IN 1951 LEWISBURG WV....30 IN 2008 LYNCHBURG VA....32 IN 1924 && .EQUIPMENT... AS OF 120 AM EST MONDAY... KFCX RADAR DOWN DUE TO TRANSMITTER FAULT. TECHNICIANS WILL WORK ON RESTORING THIS BY NOON TODAY. THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT OF SERVICE UNTIL MONDAY WHEN TECHNICIANS WILL REPLACE THE SENSOR. UNTIL THEN THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS STAFFED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST TUESDAY FOR VAZ015. NC...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST TUESDAY FOR NCZ001-018. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...RCS/WP SHORT TERM...KK LONG TERM...RAB AVIATION...RCS/WP CLIMATE...RCS EQUIPMENT...WERT/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1102 AM EST MON NOV 17 2014 .SYNOPSIS... A STRONG COLD FRONT SWINGS ACROSS THE AREA TODAY. ARCTIC AIR WILL FOLLOW TONIGHT WITH HIGH PRESSURE MOVING INTO THE MID MISSISSIPPI VALLEY. EXPECT A PERIOD OF SNOW SHOWERS...WINDS AND COLD WIND CHILLS LATE TONIGHT INTO TUESDAY MORNING AS A RESULT. HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1040 AM EST MONDAY... BASED ON LATEST SURFACE OBSERVATIONS... THE COLD FRONT APPEARS TO BE MOVING A COUPLE HOURS AHEAD OF THE PREVIOUS FORECAST. THIS IS REFLECTED IN THE FORECAST WITH REDUCED TEMPERATURES AND EARLIER ONSET OF SNOW IN THE WESTERN SLOPES. SNOW IS NOW FORECAST TO BEGIN AROUND 3PM FOR WESTERN GREENBRIER COUNTRY. PREVIOUS DISCUSSION... EARLIER RUN OF THE HRRR HAD A GREAT HANDLE ON THE RAIN MOVING IN FROM THE SOUTHWEST. FOLLOWED ITS SOLUTION THROUGH THE MORNING...BLENDING IN THE 00Z GFS/NAM. LOOKS LIKE A SLAM DUNK FOR EVERYONE SEEING RAIN TODAY...THOUGH AMOUNTS MAY BE LESS THAN EARLIER THOUGHT AS DID NOT SEE AS MUCH FALL SUNDAY. STILL A GOOD ONE HALF TO THREE QUARTERS OF AN INCH WILL OCCUR TODAY. THIS FRONT LOCATED ACROSS THE CENTRAL APPALACHIANS SOUTHWEST INTO ALABAMA WILL SLIDE EAST ACROSS THE AREA TODAY...WITH A COUPLE WAVES OF LOW PRESSURE ALONG IT. THE MAIN FORECAST ISSUE WILL BE THE COLDER AIR ARRIVING BEHIND THE FRONT. THE 00Z NAM DEPICTED THE COLDER AIR BETTER AT 06Z AT 8H THAN THE GFS/ECMWF...SO LEANED TOWARD IT TEMP FORECAST. SHOULD SEE DEEP MOISTURE EDGE EAST EARLY THIS AFTERNOON IN THE MTNS WHILE THE COLDER AIR STARTS TURNING RESIDUAL SHOWERS OVER TO SNOW LATER IN THE AFTERNOON. BY DUSK MOST OF THE EASTERN HALF OF THE CWA WILL BE DRYING OUT AS WINDS TURN WNW. TEMPS DESPITE THE RAIN...OR REALLY AS A RESULT OF THE RAIN BRINGING DOWN THE WARMER TEMPS ALOFT MAY BRING READINGS INTO THE 50S BEFORE THE COLD AIR ARRIVES IN THE PIEDMONT THIS AFTERNOON. IN THE MTNS HIGHS SHOULD BE OCCURRING BY MIDDAY THEN DROPPING IN THE LATE AFTERNOON. FORECAST SOUNDINGS IN THE MTNS SHOW MOISTURE BECOMING SHALLOW FAST...WITH THE FAVORABLE SNOW GROWTH TEMPS ALOFT NOT BEING REALIZED UNTIL LATE EVENING...SO COULD BE SOME PATCHY FREEZING DRIZZLE ISSUES...AND WILL ADVERTISE THIS IN THE MTNS OF THE FAR WEST THIS EVENING. THIS HERE LIES THE PROBLEM...WHERE IT RAINS...COMBINED WITH ARCTIC AIR ARRIVING AND SNIZZLE(SNOW AND FREEZING DRIZZLE) FOLLOWING...ROADS WILL BECOME SLICK IN THE HIGHER ELEVATIONS BY LATE DUSK. AFTER COLLABORATING WITH NEIGHBORING OFFICES...IT WAS DECIDED TO GO WITH A WINTER WX ADVISORY FOR THE NC MTNS INTO THE GRAYSON HIGHLANDS...BUT TO DELAY ANY HEADLINES...IF THEY ARE NEEDED FURTHER NORTH INTO THE MTN EMPIRE OF SW VA AND SE WV MTNS. STILL THINK THE TEMPS FALLING FAST LATE TONIGHT MAY REQUIRE AT LEAST A SPECIAL WX STATEMENT. THE SNOWFALL ACCUMULATION WILL BE LIGHT GIVEN THE LIMITED MOISTURE BUT 1 TO 3 INCHES IN THE WESTERN SLOPES ARE POSSIBLE INTO TUESDAY MORNING. IN ADDITION...THE WINDS WILL BE GUSTING OVER 40 MPH WITH 6 HR PRESSURE RISES OF 5-7MB EXPECTED BEHIND THE FRONT THIS EVENING INTO TUESDAY MORNING. THIS WAS ADDED TO THE WINTER WX ADVISORY IN THE NC MTNS. CLOUDS MAY PREVENT IDEAL MIXING OF THE STRONGER WINDS ALOFT...BUT WHERE IT THE CLOUD/CLEARING LINE IS ALONG/NEAR THE BLUE RIDGE...THINK AN OCCASIONAL 50 MPH GUST WILL BE REALIZED. OUTSIDE THE WINTER WX ADVISORY FOR ELEVATIONS ABOVE 3000 FT...HIGHLIGHT WEATHER IN THE HAZARDOUS WEATHER OUTLOOK. WILL TAKE A LOOK AT MORE DATA COMING IN AND FURTHER COORDINATING WITH OTHER WFO OFFICES TO SEE IF MORE HEADLINES ARE NEEDED. FOR TONIGHT...TEMPS WILL DROP INTO THE TEENS MOUNTAINS...SOME SINGLE DIGITS HIGHEST ELEVATIONS...WITH 20S IN THE EAST. WIND CHILLS BY DAWN TUESDAY WILL RANGE FROM 5 ABOVE TO 5 BELOW IN THE MOUNTAINS...TO THE TEENS IN THE EAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 315 AM EST MONDAY... COLD FRONT PUSHES OUT INTO THE ATLANTIC OCEAN TUESDAY AS THE 1033 SURFACE HIGH PRESSURE IN TEXAS BUILDS NORTHWARD INTO OUR REGION. THE AXIS OF THE UPPER TROF CROSS OUR AREA TUESDAY INTO TUESDAY NIGHT. GUSTY NORTHWEST WINDS WILL CONTINUE TUESDAY AS A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE REGION THROUGH TUESDAY. THE GFS...NAM AND HIRESW-ARW SHOWED UPSLOPE SNOW SHOWERS AND SNOW FLURRIES CONTINUE IN THE WESTERN MOUNTAINS. ADDITIONAL LIGHT ACCUMULATIONS MAY BE POSSIBLE IN THE NORTHWEST UPSLOPE FAVORED LOCATIONS. HIGH TEMPERATURES TUESDAY WILL RANGE FROM THE UPPER TEENS IN THE NORTHWEST MOUNTAINS TO THE MID 30S IN THE PIEDMONT. HIGH PRESSURE CONTINUES TRAVEL EASTWARD TUESDAY NIGHT. TUESDAY NIGHT WILL BE A VERY COLD NIGHT WITH TEMPERATURES ACROSS THE AREA RANGING FROM THE SINGLE DIGITS IN THE HIGHER ELEVATIONS TO THE UPPER TEENS ACROSS THE PIEDMONT. WINDS WILL DECREASE TUESDAY NIGHT...BUT WIND CHILLS WILL BE COLD WITH SINGLE DIGITS IN THE WEST TO TEENS IN THE EAST. A WARM FRONT WILL PASS OVER THE REGION WEDNESDAY...AS A COLD FRONT DROPS SOUTH INTO THE OHIO VALLEY. WEDNESDAY AFTERNOON HIGH TEMPERATURES WILL AVERAGE 20F COLDER THAN NORMAL WITH READINGS FROM THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE PIEDMONT. COLD FRONT APPROACHES FROM THE WEST WEDNESDAY NIGHT. ALLOWED FOR ISOLATED SNOW SHOWERS ACROSS THE NORTH. LOW TEMPERATURES WEDNESDAY NIGHT WILL GENERALLY BE FROM AROUND 20 DEGREES TO THE MID 20S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 400 PM EST SUNDAY... SURGE OF ARCTIC AIR TO INVADE THE REGION INTO THURSDAY. THIS WAS NOT ADVERTISED A FEW RUNS BACK...BUT GIVEN GENERAL CONSENSUS AMONG THE MODELS AND A PREVAILING MEAN DEEP MERIDIONAL TROUGH ACROSS THE EASTERN HALF OF THE U.S...THIS APPEARS TO BE A REASONABLE SOLUTION AND THUS WILL LEAN IN THIS DIRECTION. HOWEVER...IN TERMS OF INTENSITY...THIS FINAL ARCTIC SURGE WILL NOT EVEN COME CLOSE TO THE ONE EARLIER IN THE WEEK. MOISTURE IS LIMITED...BUT SLIGHT CHC TO LOW CHC POPS FOR UPSLOPE -SHSN ACROSS THE USUAL WESTERN UPSLOPE AREAS OF THE ALLEGHANYS SEEMS REASONABLE AND HAVE BEEN INCLUDED...WITH NO MENTION OF POPS EAST OF THE ALLEGHANY FRONT. THE PARENT ARCTIC HIGH WILL SETTLE OVER THE REGION EARLY SATURDAY...SO BELOW NORMAL TEMPERATURES SHOULD REMAIN IN PLACE THROUGH SAT MORNING. MODEL TEMPS IN REASONABLE AGREEMENT THROUGH FRI...BUT FEEL THE GFS MOS IS TOO QUICK TO SPREAD WARMER RETURN FLOW INTO THE REGION SAT...SO LEANED TOWARD THE COLDER ECMWF MOS. BIGGER QUESTIONS REMAIN FOR THE REMAINDER OF THE EXTENDED PERIODS. AS THE ARCTIC HIGH RETREATS TOWARD THE COAST SAT...THE LONG AWAITED RETURN TO A LESS AMPLIFIED FLOW PATTERN BEGINS TO EVOLVE. THE EASTERN U.S. TROUGH IS REPLACED BY A SHORT WAVE RIDGE AS BROAD MEAN TROUGHING RELOCATES TO THE WESTERN/CENTRAL U.S. THE MAIN CONCERN FOR THE WEEKEND IS THE TIMING AND ASSOCIATED WARMING/MOISTENING WITH A STRONG NEGATIVELY TITLED HIGHLY PROGRESSIVE SHORT WAVE PROGGED TO EJECT OUT OF THE BASE OF THE MEAN TROUGH INTO THE SOUTHEAST STATES SAT NIGHT-SUN. 12Z ECMWF IN EXCELLENT AGREEMENT WITH 12Z GFS IN BRINGING THIS SYSTEM THROUGH OUR REGION SUN AFTERNOON. SUPERBLEND POPS WERE LIKELY TO CATEGORICAL SUN NIGHT-MON. GIVEN THE ASSOCIATED PVA...AND AMOUNT OF MOIST/WARM ADVECTION INTO THE REGION...THIS SEEMED REASONABLE. HOWEVER...NEIGHBORING OFFICES WERE NOT ON BOARD WITH THESE HIGH VALUES THIS FAR OUT...SO STOPPED AT A MORE REASONABLE 50 PERCENT VALUE FOR NOW. GIVEN RECENT MODEL RUN-TO-RUN VARIATION...THAT SEEMED REASONABLE FOR SURE. A SIGNIFICANT WARM UP WILL ENSUE SAT- SUN...BUT AS NOTED ABOVE...PERHAPS NOT TO THE DEGREE ADVERTISED BY THE MEX MOS. THUS...HAVE USED A MODEL BLEND FOR SAT- SUN. AN EVEN MORE SIGNIFICANT NEGATIVELY TILTED UPPER TROUGH APPEARS ON TRACK FOR THE REGION INTO MON. ECMWF/GFS SHOWING SOME INCREDIBLY WARM/MOIST AIR FOR THIS TIME OF YEAR SPREADING INTO THE REGION FROM THE SOUTH BY MON MORNING ON THE HEELS A STRONG LOW-LEVEL SOUTHERLY JET WITH DEWPOINTS APPROACHING 60 DEGREES BY MON AFTERNOON ACROSS THE PIEDMONT AND SOUTHSIDE. PROGGED LIFTED INDICES AND CAPES ALONG WITH EVIDENT SHEAR SUGGEST SOME -TSRA MAY NEED TO BE CONSIDERED BY MON AFTERNOON ACROSS THE PIEDMONT. TO SAY THE LEAST...EARLY NEXT WEEK WILL BE IN SHARP CONTRAST TO THE WEATHER EXPECTED THIS WEEK WITH TEMPERATURES ACTUALLY ABOVE SEASONAL NORMALS...ESPECIALLY IF LOWS ARE ONLY IN THE 50S MON MORNING WITH HIGHS IN THE 60S. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... AS OF 640 AM EST MONDAY... RAINFALL INCREASING OVER THE AREA THIS MORNING AND SHOULD SPREAD EAST THRU LATE MORNING. AIRPORTS WILL FLUCTUATE IN THE CIGS/VSBYS WITH MODERATE TO AT TIMES HEAVY RAIN BRING CIGS UP AND VSBYS DOWN WHILE LIGHTER RAINS ALLOW CIGS TO DROP TO IFR/LIFR. STRONG LLJ TO INCREASE AT THE TAF START TIME THEN LIFT OUT BY MIDDAY. INVERSION AT THE SFC WILL ALLOW FOR LIGHT WINDS...SUCH THAT LOW LVL WIND SHEAR WILL OCCUR AS 2KFT AGL WILL START RUNNING INTO THE 30-45 KT JET. LOOK FOR THE RAIN TO DIMINISH IN THE MTNS BY EARLY AFTERNOON WITH COLDER AIR WORKING IN BY 21-00Z...WITH UPSLOPE SNOW SHOWERS GETTING GOING. FURTHER EAST THE RAIN SHIELD SHOULD EXIT ROA/BCB BY 19-21Z...LYH/DAN 22Z. WINDS WILL PICK UP FROM THE WNW AND GUST TO 30 TO 40 MPH IN THE MTNS TONIGHT. CIGS WILL STAY MVFR IN THE MTNS TONIGHT AND VFR EAST. ARCTIC BLAST OF AIR MAY LEAD TO WATER FREEZING ON RUNWAYS/AIRPLANES THIS EVENING...THOUGH WINDS MAY LEAD TO QUICKER EVAPORATION OF THE WET SFCS. EXTENDED DISCUSSION... EXPECT MAINLY VFR WEATHER TUESDAY-THURSDAY. NEXT SYSTEM APPEARS TO ARRIVE FRIDAY WITH MVFR CIGS IN THE MTNS. && .CLIMATE... AS OF 315 PM EST SUNDAY... RECORD COOLEST HIGHS...TUESDAY NOV 18TH BLACKSBURG VA...30 IN 2008 BLUEFIELD WV....27 IN 2008 DANVILLE VA.....38 IN 1959 ROANOKE VA......33 IN 1951 LEWISBURG WV....30 IN 2008 LYNCHBURG VA....32 IN 1924 && .EQUIPMENT... AS OF 120 AM EST MONDAY... KFCX RADAR DOWN DUE TO TRANSMITTER FAULT. TECHNICIANS WILL WORK ON RESTORING THIS BY NOON TODAY. THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT OF SERVICE UNTIL MONDAY WHEN TECHNICIANS WILL REPLACE THE SENSOR. UNTIL THEN THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS STAFFED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST TUESDAY FOR VAZ015. NC...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST TUESDAY FOR NCZ001-018. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...SMR/RCS/WP SHORT TERM...KK LONG TERM...RAB AVIATION...WP CLIMATE...RCS EQUIPMENT...WERT/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
654 AM EST MON NOV 17 2014 .SYNOPSIS... A STRONG COLD FRONT SWINGS ACROSS THE AREA TODAY. ARCTIC AIR WILL FOLLOW TONIGHT WITH HIGH PRESSURE MOVING INTO THE MID MISSISSIPPI VALLEY. EXPECT A PERIOD OF SNOW SHOWERS...WINDS AND COLD WIND CHILLS LATE TONIGHT INTO TUESDAY MORNING AS A RESULT. HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM EST MONDAY... RADAR STARTING TO FILL IN OVER THE MTNS THIS MORNING. FORECAST ON TRACK...SO NO MAJOR CHANGES WITH UPDATE...EXCEPT WITH WARMER TEMPS IN THE FAR SW VA AREA. PREVIOUS DISCUSSION... EARLIER RUN OF THE HRRR HAD A GREAT HANDLE ON THE RAIN MOVING IN FROM THE SOUTHWEST. FOLLOWED ITS SOLUTION THROUGH THE MORNING...BLENDING IN THE 00Z GFS/NAM. LOOKS LIKE A SLAM DUNK FOR EVERYONE SEEING RAIN TODAY...THOUGH AMOUNTS MAY BE LESS THAN EARLIER THOUGHT AS DID NOT SEE AS MUCH FALL SUNDAY. STILL A GOOD ONE HALF TO THREE QUARTERS OF AN INCH WILL OCCUR TODAY. THIS FRONT LOCATED ACROSS THE CENTRAL APPALACHIANS SOUTHWEST INTO ALABAMA WILL SLIDE EAST ACROSS THE AREA TODAY...WITH A COUPLE WAVES OF LOW PRESSURE ALONG IT. THE MAIN FORECAST ISSUE WILL BE THE COLDER AIR ARRIVING BEHIND THE FRONT. THE 00Z NAM DEPICTED THE COLDER AIR BETTER AT 06Z AT 8H THAN THE GFS/ECMWF...SO LEANED TOWARD IT TEMP FORECAST. SHOULD SEE DEEP MOISTURE EDGE EAST EARLY THIS AFTERNOON IN THE MTNS WHILE THE COLDER AIR STARTS TURNING RESIDUAL SHOWERS OVER TO SNOW LATER IN THE AFTERNOON. BY DUSK MOST OF THE EASTERN HALF OF THE CWA WILL BE DRYING OUT AS WINDS TURN WNW. TEMPS DESPITE THE RAIN...OR REALLY AS A RESULT OF THE RAIN BRINGING DOWN THE WARMER TEMPS ALOFT MAY BRING READINGS INTO THE 50S BEFORE THE COLD AIR ARRIVES IN THE PIEDMONT THIS AFTERNOON. IN THE MTNS HIGHS SHOULD BE OCCURRING BY MIDDAY THEN DROPPING IN THE LATE AFTERNOON. FORECAST SOUNDINGS IN THE MTNS SHOW MOISTURE BECOMING SHALLOW FAST...WITH THE FAVORABLE SNOW GROWTH TEMPS ALOFT NOT BEING REALIZED UNTIL LATE EVENING...SO COULD BE SOME PATCHY FREEZING DRIZZLE ISSUES...AND WILL ADVERTISE THIS IN THE MTNS OF THE FAR WEST THIS EVENING. THIS HERE LIES THE PROBLEM...WHERE IT RAINS...COMBINED WITH ARCTIC AIR ARRIVING AND SNIZZLE(SNOW AND FREEZING DRIZZLE) FOLLOWING...ROADS WILL BECOME SLICK IN THE HIGHER ELEVATIONS BY LATE DUSK. AFTER COLLABORATING WITH NEIGHBORING OFFICES...IT WAS DECIDED TO GO WITH A WINTER WX ADVISORY FOR THE NC MTNS INTO THE GRAYSON HIGHLANDS...BUT TO DELAY ANY HEADLINES...IF THEY ARE NEEDED FURTHER NORTH INTO THE MTN EMPIRE OF SW VA AND SE WV MTNS. STILL THINK THE TEMPS FALLING FAST LATE TONIGHT MAY REQUIRE AT LEAST A SPECIAL WX STATEMENT. THE SNOWFALL ACCUMULATION WILL BE LIGHT GIVEN THE LIMITED MOISTURE BUT 1 TO 3 INCHES IN THE WESTERN SLOPES ARE POSSIBLE INTO TUESDAY MORNING. IN ADDITION...THE WINDS WILL BE GUSTING OVER 40 MPH WITH 6 HR PRESSURE RISES OF 5-7MB EXPECTED BEHIND THE FRONT THIS EVENING INTO TUESDAY MORNING. THIS WAS ADDED TO THE WINTER WX ADVISORY IN THE NC MTNS. CLOUDS MAY PREVENT IDEAL MIXING OF THE STRONGER WINDS ALOFT...BUT WHERE IT THE CLOUD/CLEARING LINE IS ALONG/NEAR THE BLUE RIDGE...THINK AN OCCASIONAL 50 MPH GUST WILL BE REALIZED. OUTSIDE THE WINTER WX ADVISORY FOR ELEVATIONS ABOVE 3000 FT...HIGHLIGHT WEATHER IN THE HAZARDOUS WEATHER OUTLOOK. WILL TAKE A LOOK AT MORE DATA COMING IN AND FURTHER COORDINATING WITH OTHER WFO OFFICES TO SEE IF MORE HEADLINES ARE NEEDED. FOR TONIGHT...TEMPS WILL DROP INTO THE TEENS MOUNTAINS...SOME SINGLE DIGITS HIGHEST ELEVATIONS...WITH 20S IN THE EAST. WIND CHILLS BY DAWN TUESDAY WILL RANGE FROM 5 ABOVE TO 5 BELOW IN THE MOUNTAINS...TO THE TEENS IN THE EAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 315 AM EST MONDAY... COLD FRONT PUSHES OUT INTO THE ATLANTIC OCEAN TUESDAY AS THE 1033 SURFACE HIGH PRESSURE IN TEXAS BUILDS NORTHWARD INTO OUR REGION. THE AXIS OF THE UPPER TROF CROSS OUR AREA TUESDAY INTO TUESDAY NIGHT. GUSTY NORTHWEST WINDS WILL CONTINUE TUESDAY AS A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE REGION THROUGH TUESDAY. THE GFS...NAM AND HIRESW-ARW SHOWED UPSLOPE SNOW SHOWERS AND SNOW FLURRIES CONTINUE IN THE WESTERN MOUNTAINS. ADDITIONAL LIGHT ACCUMULATIONS MAY BE POSSIBLE IN THE NORTHWEST UPSLOPE FAVORED LOCATIONS. HIGH TEMPERATURES TUESDAY WILL RANGE FROM THE UPPER TEENS IN THE NORTHWEST MOUNTAINS TO THE MID 30S IN THE PIEDMONT. HIGH PRESSURE CONTINUES TRAVEL EASTWARD TUESDAY NIGHT. TUESDAY NIGHT WILL BE A VERY COLD NIGHT WITH TEMPERATURES ACROSS THE AREA RANGING FROM THE SINGLE DIGITS IN THE HIGHER ELEVATIONS TO THE UPPER TEENS ACROSS THE PIEDMONT. WINDS WILL DECREASE TUESDAY NIGHT...BUT WIND CHILLS WILL BE COLD WITH SINGLE DIGITS IN THE WEST TO TEENS IN THE EAST. A WARM FRONT WILL PASS OVER THE REGION WEDNESDAY...AS A COLD FRONT DROPS SOUTH INTO THE OHIO VALLEY. WEDNESDAY AFTERNOON HIGH TEMPERATURES WILL AVERAGE 20F COLDER THAN NORMAL WITH READINGS FROM THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE PIEDMONT. COLD FRONT APPROACHES FROM THE WEST WEDNESDAY NIGHT. ALLOWED FOR ISOLATED SNOW SHOWERS ACROSS THE NORTH. LOW TEMPERATURES WEDNESDAY NIGHT WILL GENERALLY BE FROM AROUND 20 DEGREES TO THE MID 20S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 400 PM EST SUNDAY... SURGE OF ARCTIC AIR TO INVADE THE REGION INTO THURSDAY. THIS WAS NOT ADVERTISED A FEW RUNS BACK...BUT GIVEN GENERAL CONSENSUS AMONG THE MODELS AND A PREVAILING MEAN DEEP MERIDIONAL TROUGH ACROSS THE EASTERN HALF OF THE U.S...THIS APPEARS TO BE A REASONABLE SOLUTION AND THUS WILL LEAN IN THIS DIRECTION. HOWEVER...IN TERMS OF INTENSITY...THIS FINAL ARCTIC SURGE WILL NOT EVEN COME CLOSE TO THE ONE EARLIER IN THE WEEK. MOISTURE IS LIMITED...BUT SLIGHT CHC TO LOW CHC POPS FOR UPSLOPE -SHSN ACROSS THE USUAL WESTERN UPSLOPE AREAS OF THE ALLEGHANYS SEEMS REASONABLE AND HAVE BEEN INCLUDED...WITH NO MENTION OF POPS EAST OF THE ALLEGHANY FRONT. THE PARENT ARCTIC HIGH WILL SETTLE OVER THE REGION EARLY SATURDAY...SO BELOW NORMAL TEMPERATURES SHOULD REMAIN IN PLACE THROUGH SAT MORNING. MODEL TEMPS IN REASONABLE AGREEMENT THROUGH FRI...BUT FEEL THE GFS MOS IS TOO QUICK TO SPREAD WARMER RETURN FLOW INTO THE REGION SAT...SO LEANED TOWARD THE COLDER ECMWF MOS. BIGGER QUESTIONS REMAIN FOR THE REMAINDER OF THE EXTENDED PERIODS. AS THE ARCTIC HIGH RETREATS TOWARD THE COAST SAT...THE LONG AWAITED RETURN TO A LESS AMPLIFIED FLOW PATTERN BEGINS TO EVOLVE. THE EASTERN U.S. TROUGH IS REPLACED BY A SHORT WAVE RIDGE AS BROAD MEAN TROUGHING RELOCATES TO THE WESTERN/CENTRAL U.S. THE MAIN CONCERN FOR THE WEEKEND IS THE TIMING AND ASSOCIATED WARMING/MOISTENING WITH A STRONG NEGATIVELY TITLED HIGHLY PROGRESSIVE SHORT WAVE PROGGED TO EJECT OUT OF THE BASE OF THE MEAN TROUGH INTO THE SOUTHEAST STATES SAT NIGHT-SUN. 12Z ECMWF IN EXCELLENT AGREEMENT WITH 12Z GFS IN BRINGING THIS SYSTEM THROUGH OUR REGION SUN AFTERNOON. SUPERBLEND POPS WERE LIKELY TO CATEGORICAL SUN NIGHT-MON. GIVEN THE ASSOCIATED PVA...AND AMOUNT OF MOIST/WARM ADVECTION INTO THE REGION...THIS SEEMED REASONABLE. HOWEVER...NEIGHBORING OFFICES WERE NOT ON BOARD WITH THESE HIGH VALUES THIS FAR OUT...SO STOPPED AT A MORE REASONABLE 50 PERCENT VALUE FOR NOW. GIVEN RECENT MODEL RUN-TO-RUN VARIATION...THAT SEEMED REASONABLE FOR SURE. A SIGNIFICANT WARM UP WILL ENSUE SAT- SUN...BUT AS NOTED ABOVE...PERHAPS NOT TO THE DEGREE ADVERTISED BY THE MEX MOS. THUS...HAVE USED A MODEL BLEND FOR SAT- SUN. AN EVEN MORE SIGNIFICANT NEGATIVELY TILTED UPPER TROUGH APPEARS ON TRACK FOR THE REGION INTO MON. ECMWF/GFS SHOWING SOME INCREDIBLY WARM/MOIST AIR FOR THIS TIME OF YEAR SPREADING INTO THE REGION FROM THE SOUTH BY MON MORNING ON THE HEELS A STRONG LOW-LEVEL SOUTHERLY JET WITH DEWPOINTS APPROACHING 60 DEGREES BY MON AFTERNOON ACROSS THE PIEDMONT AND SOUTHSIDE. PROGGED LIFTED INDICES AND CAPES ALONG WITH EVIDENT SHEAR SUGGEST SOME -TSRA MAY NEED TO BE CONSIDERED BY MON AFTERNOON ACROSS THE PIEDMONT. TO SAY THE LEAST...EARLY NEXT WEEK WILL BE IN SHARP CONTRAST TO THE WEATHER EXPECTED THIS WEEK WITH TEMPERATURES ACTUALLY ABOVE SEASONAL NORMALS...ESPECIALLY IF LOWS ARE ONLY IN THE 50S MON MORNING WITH HIGHS IN THE 60S. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 640 AM EST MONDAY... RAINFALL INCREASING OVER THE AREA THIS MORNING AND SHOULD SPREAD EAST THRU LATE MORNING. AIRPORTS WILL FLUCTUATE IN THE CIGS/VSBYS WITH MODERATE TO AT TIMES HEAVY RAIN BRING CIGS UP AND VSBYS DOWN WHILE LIGHTER RAINS ALLOW CIGS TO DROP TO IFR/LIFR. STRONG LLJ TO INCREASE AT THE TAF START TIME THEN LIFT OUT BY MIDDAY. INVERSION AT THE SFC WILL ALLOW FOR LIGHT WINDS...SUCH THAT LOW LVL WIND SHEAR WILL OCCUR AS 2KFT AGL WILL START RUNNING INTO THE 30-45 KT JET. LOOK FOR THE RAIN TO DIMINISH IN THE MTNS BY EARLY AFTERNOON WITH COLDER AIR WORKING IN BY 21-00Z...WITH UPSLOPE SNOW SHOWERS GETTING GOING. FURTHER EAST THE RAIN SHIELD SHOULD EXIT ROA/BCB BY 19-21Z...LYH/DAN 22Z. WINDS WILL PICK UP FROM THE WNW AND GUST TO 30 TO 40 MPH IN THE MTNS TONIGHT. CIGS WILL STAY MVFR IN THE MTNS TONIGHT AND VFR EAST. ARCTIC BLAST OF AIR MAY LEAD TO WATER FREEZING ON RUNWAYS/AIRPLANES THIS EVENING...THOUGH WINDS MAY LEAD TO QUICKER EVAPORATION OF THE WET SFCS. EXTENDED DISCUSSION... EXPECT MAINLY VFR WEATHER TUESDAY-THURSDAY. NEXT SYSTEM APPEARS TO ARRIVE FRIDAY WITH MVFR CIGS IN THE MTNS. && .CLIMATE... AS OF 315 PM EST SUNDAY... RECORD COOLEST HIGHS...TUESDAY NOV 18TH BLACKSBURG VA...30 IN 2008 BLUEFIELD WV....27 IN 2008 DANVILLE VA.....38 IN 1959 ROANOKE VA......33 IN 1951 LEWISBURG WV....30 IN 2008 LYNCHBURG VA....32 IN 1924 && .EQUIPMENT... AS OF 120 AM EST MONDAY... KFCX RADAR DOWN DUE TO TRANSMITTER FAULT. TECHNICIANS WILL WORK ON RESTORING THIS BY NOON TODAY. THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT OF SERVICE UNTIL MONDAY WHEN TECHNICIANS WILL REPLACE THE SENSOR. UNTIL THEN THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS STAFFED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST TUESDAY FOR VAZ015. NC...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST TUESDAY FOR NCZ001-018. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...WP SHORT TERM...KK LONG TERM...RAB AVIATION...WP CLIMATE...RCS EQUIPMENT...WERT/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
405 AM EST MON NOV 17 2014 .SYNOPSIS... A STRONG COLD FRONT SWINGS ACROSS THE AREA TODAY. ARCTIC AIR WILL FOLLOW TONIGHT WITH HIGH PRESSURE MOVING INTO THE MID MISSISSIPPI VALLEY. EXPECT A PERIOD OF SNOW SHOWERS...WINDS AND COLD WIND CHILLS LATE TONIGHT INTO TUESDAY MORNING AS A RESULT. HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM EST MONDAY... EARLIER RUN OF THE HRRR HAD A GREAT HANDLE ON THE RAIN MOVING IN FROM THE SOUTHWEST. FOLLOWED ITS SOLUTION THROUGH THE MORNING...BLENDING IN THE 00Z GFS/NAM. LOOKS LIKE A SLAM DUNK FOR EVERYONE SEEING RAIN TODAY...THOUGH AMOUNTS MAY BE LESS THAN EARLIER THOUGHT AS DID NOT SEE AS MUCH FALL SUNDAY. STILL A GOOD ONE HALF TO THREE QUARTERS OF AN INCH WILL OCCUR TODAY. THIS FRONT LOCATED ACROSS THE CENTRAL APPALACHIANS SOUTHWEST INTO ALABAMA WILL SLIDE EAST ACROSS THE AREA TODAY...WITH A COUPLE WAVES OF LOW PRESSURE ALONG IT. THE MAIN FORECAST ISSUE WILL BE THE COLDER AIR ARRIVING BEHIND THE FRONT. THE 00Z NAM DEPICTED THE COLDER AIR BETTER AT 06Z AT 8H THAN THE GFS/ECMWF...SO LEANED TOWARD IT TEMP FORECAST. SHOULD SEE DEEP MOISTURE EDGE EAST EARLY THIS AFTERNOON IN THE MTNS WHILE THE COLDER AIR STARTS TURNING RESIDUAL SHOWERS OVER TO SNOW LATER IN THE AFTERNOON. BY DUSK MOST OF THE EASTERN HALF OF THE CWA WILL BE DRYING OUT AS WINDS TURN WNW. TEMPS DESPITE THE RAIN...OR REALLY AS A RESULT OF THE RAIN BRINGING DOWN THE WARMER TEMPS ALOFT MAY BRING READINGS INTO THE 50S BEFORE THE COLD AIR ARRIVES IN THE PIEDMONT THIS AFTERNOON. IN THE MTNS HIGHS SHOULD BE OCCURRING BY MIDDAY THEN DROPPING IN THE LATE AFTERNOON. FORECAST SOUNDINGS IN THE MTNS SHOW MOISTURE BECOMING SHALLOW FAST...WITH THE FAVORABLE SNOW GROWTH TEMPS ALOFT NOT BEING REALIZED UNTIL LATE EVENING...SO COULD BE SOME PATCHY FREEZING DRIZZLE ISSUES...AND WILL ADVERTISE THIS IN THE MTNS OF THE FAR WEST THIS EVENING. THIS HERE LIES THE PROBLEM...WHERE IT RAINS...COMBINED WITH ARCTIC AIR ARRIVING AND SNIZZLE(SNOW AND FREEZING DRIZZLE) FOLLOWING...ROADS WILL BECOME SLICK IN THE HIGHER ELEVATIONS BY LATE DUSK. AFTER COLLABORATING WITH NEIGHBORING OFFICES...IT WAS DECIDED TO GO WITH A WINTER WX ADVISORY FOR THE NC MTNS INTO THE GRAYSON HIGHLANDS...BUT TO DELAY ANY HEADLINES...IF THEY ARE NEEDED FURTHER NORTH INTO THE MTN EMPIRE OF SW VA AND SE WV MTNS. STILL THINK THE TEMPS FALLING FAST LATE TONIGHT MAY REQUIRE AT LEAST A SPECIAL WX STATEMENT. THE SNOWFALL ACCUMULATION WILL BE LIGHT GIVEN THE LIMITED MOISTURE BUT 1 TO 3 INCHES IN THE WESTERN SLOPES ARE POSSIBLE INTO TUESDAY MORNING. IN ADDITION...THE WINDS WILL BE GUSTING OVER 40 MPH WITH 6 HR PRESSURE RISES OF 5-7MB EXPECTED BEHIND THE FRONT THIS EVENING INTO TUESDAY MORNING. THIS WAS ADDED TO THE WINTER WX ADVISORY IN THE NC MTNS. CLOUDS MAY PREVENT IDEAL MIXING OF THE STRONGER WINDS ALOFT...BUT WHERE IT THE CLOUD/CLEARING LINE IS ALONG/NEAR THE BLUE RIDGE...THINK AN OCCASIONAL 50 MPH GUST WILL BE REALIZED. OUTSIDE THE WINTER WX ADVISORY FOR ELEVATIONS ABOVE 3000 FT...HIGHLIGHT WEATHER IN THE HAZARDOUS WEATHER OUTLOOK. WILL TAKE A LOOK AT MORE DATA COMING IN AND FURTHER COORDINATING WITH OTHER WFO OFFICES TO SEE IF MORE HEADLINES ARE NEEDED. FOR TONIGHT...TEMPS WILL DROP INTO THE TEENS MOUNTAINS...SOME SINGLE DIGITS HIGHEST ELEVATIONS...WITH 20S IN THE EAST. WIND CHILLS BY DAWN TUESDAY WILL RANGE FROM 5 ABOVE TO 5 BELOW IN THE MOUNTAINS...TO THE TEENS IN THE EAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 315 AM EST MONDAY... COLD FRONT PUSHES OUT INTO THE ATLANTIC OCEAN TUESDAY AS THE 1033 SURFACE HIGH PRESSURE IN TEXAS BUILDS NORTHWARD INTO OUR REGION. THE AXIS OF THE UPPER TROF CROSS OUR AREA TUESDAY INTO TUESDAY NIGHT. GUSTY NORTHWEST WINDS WILL CONTINUE TUESDAY AS A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE REGION THROUGH TUESDAY. THE GFS...NAM AND HIRESW-ARW SHOWED UPSLOPE SNOW SHOWERS AND SNOW FLURRIES CONTINUE IN THE WESTERN MOUNTAINS. ADDITIONAL LIGHT ACCUMULATIONS MAY BE POSSIBLE IN THE NORTHWEST UPSLOPE FAVORED LOCATIONS. HIGH TEMPERATURES TUESDAY WILL RANGE FROM THE UPPER TEENS IN THE NORTHWEST MOUNTAINS TO THE MID 30S IN THE PIEDMONT. HIGH PRESSURE CONTINUES TRAVEL EASTWARD TUESDAY NIGHT. TUESDAY NIGHT WILL BE A VERY COLD NIGHT WITH TEMPERATURES ACROSS THE AREA RANGING FROM THE SINGLE DIGITS IN THE HIGHER ELEVATIONS TO THE UPPER TEENS ACROSS THE PIEDMONT. WINDS WILL DECREASE TUESDAY NIGHT...BUT WIND CHILLS WILL BE COLD WITH SINGLE DIGITS IN THE WEST TO TEENS IN THE EAST. A WARM FRONT WILL PASS OVER THE REGION WEDNESDAY...AS A COLD FRONT DROPS SOUTH INTO THE OHIO VALLEY. WEDNESDAY AFTERNOON HIGH TEMPERATURES WILL AVERAGE 20F COLDER THAN NORMAL WITH READINGS FROM THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE PIEDMONT. COLD FRONT APPROACHES FROM THE WEST WEDNESDAY NIGHT. ALLOWED FOR ISOLATED SNOW SHOWERS ACROSS THE NORTH. LOW TEMPERATURES WEDNESDAY NIGHT WILL GENERALLY BE FROM AROUND 20 DEGREES TO THE MID 20S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 400 PM EST SUNDAY... SURGE OF ARCTIC AIR TO INVADE THE REGION INTO THURSDAY. THIS WAS NOT ADVERTISED A FEW RUNS BACK...BUT GIVEN GENERAL CONSENSUS AMONG THE MODELS AND A PREVAILING MEAN DEEP MERIDIONAL TROUGH ACROSS THE EASTERN HALF OF THE U.S...THIS APPEARS TO BE A REASONABLE SOLUTION AND THUS WILL LEAN IN THIS DIRECTION. HOWEVER...IN TERMS OF INTENSITY...THIS FINAL ARCTIC SURGE WILL NOT EVEN COME CLOSE TO THE ONE EARLIER IN THE WEEK. MOISTURE IS LIMITED...BUT SLIGHT CHC TO LOW CHC POPS FOR UPSLOPE -SHSN ACROSS THE USUAL WESTERN UPSLOPE AREAS OF THE ALLEGHANYS SEEMS REASONABLE AND HAVE BEEN INCLUDED...WITH NO MENTION OF POPS EAST OF THE ALLEGHANY FRONT. THE PARENT ARCTIC HIGH WILL SETTLE OVER THE REGION EARLY SATURDAY...SO BELOW NORMAL TEMPERATURES SHOULD REMAIN IN PLACE THROUGH SAT MORNING. MODEL TEMPS IN REASONABLE AGREEMENT THROUGH FRI...BUT FEEL THE GFS MOS IS TOO QUICK TO SPREAD WARMER RETURN FLOW INTO THE REGION SAT...SO LEANED TOWARD THE COLDER ECMWF MOS. BIGGER QUESTIONS REMAIN FOR THE REMAINDER OF THE EXTENDED PERIODS. AS THE ARCTIC HIGH RETREATS TOWARD THE COAST SAT...THE LONG AWAITED RETURN TO A LESS AMPLIFIED FLOW PATTERN BEGINS TO EVOLVE. THE EASTERN U.S. TROUGH IS REPLACED BY A SHORT WAVE RIDGE AS BROAD MEAN TROUGHING RELOCATES TO THE WESTERN/CENTRAL U.S. THE MAIN CONCERN FOR THE WEEKEND IS THE TIMING AND ASSOCIATED WARMING/MOISTENING WITH A STRONG NEGATIVELY TITLED HIGHLY PROGRESSIVE SHORT WAVE PROGGED TO EJECT OUT OF THE BASE OF THE MEAN TROUGH INTO THE SOUTHEAST STATES SAT NIGHT-SUN. 12Z ECMWF IN EXCELLENT AGREEMENT WITH 12Z GFS IN BRINGING THIS SYSTEM THROUGH OUR REGION SUN AFTERNOON. SUPERBLEND POPS WERE LIKELY TO CATEGORICAL SUN NIGHT-MON. GIVEN THE ASSOCIATED PVA...AND AMOUNT OF MOIST/WARM ADVECTION INTO THE REGION...THIS SEEMED REASONABLE. HOWEVER...NEIGHBORING OFFICES WERE NOT ON BOARD WITH THESE HIGH VALUES THIS FAR OUT...SO STOPPED AT A MORE REASONABLE 50 PERCENT VALUE FOR NOW. GIVEN RECENT MODEL RUN-TO-RUN VARIATION...THAT SEEMED REASONABLE FOR SURE. A SIGNIFICANT WARM UP WILL ENSUE SAT- SUN...BUT AS NOTED ABOVE...PERHAPS NOT TO THE DEGREE ADVERTISED BY THE MEX MOS. THUS...HAVE USED A MODEL BLEND FOR SAT- SUN. AN EVEN MORE SIGNIFICANT NEGATIVELY TILTED UPPER TROUGH APPEARS ON TRACK FOR THE REGION INTO MON. ECMWF/GFS SHOWING SOME INCREDIBLY WARM/MOIST AIR FOR THIS TIME OF YEAR SPREADING INTO THE REGION FROM THE SOUTH BY MON MORNING ON THE HEELS A STRONG LOW-LEVEL SOUTHERLY JET WITH DEWPOINTS APPROACHING 60 DEGREES BY MON AFTERNOON ACROSS THE PIEDMONT AND SOUTHSIDE. PROGGED LIFTED INDICES AND CAPES ALONG WITH EVIDENT SHEAR SUGGEST SOME -TSRA MAY NEED TO BE CONSIDERED BY MON AFTERNOON ACROSS THE PIEDMONT. TO SAY THE LEAST...EARLY NEXT WEEK WILL BE IN SHARP CONTRAST TO THE WEATHER EXPECTED THIS WEEK WITH TEMPERATURES ACTUALLY ABOVE SEASONAL NORMALS...ESPECIALLY IF LOWS ARE ONLY IN THE 50S MON MORNING WITH HIGHS IN THE 60S. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... AS OF 1150 PM EST SUNDAY... ANOTHER LARGE AREA OF LIGHT TO MODERATE RAIN WILL CROSS THE REGION BETWEEN 08Z/3AM AND 15Z/10AM BASED ON THE LATEST HRRR AND LOCAL WRF MODELS. HIGH CONFIDENCE THAT CEILINGS WILL DROP TO IFR AS THIS RAIN MOVES IN. VISIBILITIES WILL LOWER TO MVFR WITH THE RAIN. SLEET...WHICH IS REPORTED AS U P...UNKNOWN PRECIPITATION...BY AWOS AND ASOS SENSORS IS FALLING AT KLWB. HOWEVER...WARMER AIR IS GRADUALLY ADVECTING INTO THE REGION. LITTLE DROP IN TEMPERATURE IS EXPECTED FOR THE REST OF THE NIGHT. THE SLEET AT KLWB WILL END BY MIDNIGHT WITH LITTLE TO NO ACCUMULATIONS. LOW PRESSURE OVER LOUISIANA WILL MOVE INTO THE OHIO VALLEY BY MORNING THEN WILL PUSH A STRONG COLD FRONT THROUGH THE REGION. WITH THE ARRIVAL OF THE STRONG COLD FRONT AND DOWNSLOPING WINDS CONDITIONS RETURN BACK TO VFR EAST OF THE BLUE RIDGE ON MONDAY AFTERNOON AS RAIN ENDS FROM THE WEST. BUT STRONG COLD ADVECTION AND UPSLOPE CLOUDS EXPECTED TO PERSIST WEST OF THE BLUE RIDGE WITH A PROLONGED PERIOD OF MVFR TO OCCASIONALLY IFR WEATHER IN SCATTERED SNOW SHOWERS LATER MONDAY AFTERNOON. A STRONG LOW LEVEL JET OF 50-70 KNOTS DEVELOPS OVER THE AREA TOWARD DAYBREAK. HAVE ADDED LOW LEVEL WIND SHEAR IN FOR THE TAFS. WIND GUSTS WILL INCREASE FROM THE NORTHWEST BEHIND THE FRONT UP 30 KNOTS BY EVENING. EXTENDED DISCUSSION... EXPECT MAINLY VFR WEATHER EAST OF THE BLUE RIDGE IN THE TUESDAY-FRIDAY. CONDITIONS WILL BECOME VFR WEST OF THE BLUE RIDGE UNDER SURFACE HIGH PRESSURE WEDNESDAY...BUT ANOTHER PERIOD OF UPSLOPING CLOUDS WILL BRING MVFR CONDITIONS THURSDAY AFTERNOON INTO FRIDAY AS NEXT COLD FRONT MOVES THROUGH THE AREA. && .CLIMATE... AS OF 315 PM EST SUNDAY... RECORD COOLEST HIGHS...TUESDAY NOV 18TH BLACKSBURG VA...30 IN 2008 BLUEFIELD WV....27 IN 2008 DANVILLE VA.....38 IN 1959 ROANOKE VA......33 IN 1951 LEWISBURG WV....30 IN 2008 LYNCHBURG VA....32 IN 1924 && .EQUIPMENT... AS OF 120 AM EST MONDAY... KFCX RADAR DOWN DUE TO TRANSMITTER FAULT. TECHNICIANS WILL WORK ON RESTORING THIS BY NOON TODAY. THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT OF SERVICE UNTIL MONDAY WHEN TECHNICIANS WILL REPLACE THE SENSOR. UNTIL THEN THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS STAFFED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST TUESDAY FOR VAZ015. NC...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST TUESDAY FOR NCZ001-018. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...WP SHORT TERM...KK LONG TERM...RAB AVIATION...AMS/WERT CLIMATE...RCS EQUIPMENT...WERT/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
128 AM EST MON NOV 17 2014 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL MOVE THROUGH VIRGINIA AND ADJACENT STATES ON MONDAY MORNING. A STRONG COLD FRONT WILL THEN SWEEP EAST THOUGH THE AREA ON MONDAY AFTERNOON...BRINGING ANOTHER ROUND OF VERY COLD TEMPERATURES WITH GUSTY WINDS FOR MONDAY NIGHT INTO TUESDAY...ALONG WITH SOME MOUNTAIN SNOW SHOWERS. && .NEAR TERM /THROUGH TODAY/... AS OF 120 AM EST MONDAY... RADAR BEFORE GOING DOWN SHOWED LIMITED COVERAGE OF RAIN IN THE CWA...WITH NARROW AXIS FROM THE NC FOOTHILLS INTO THE VA PIEDMONT. THE LATEST HRRR WAS HANDLING THIS FAIRLY WELL...AND THINK OVERALL A LIGHT RAIN/DRIZZLE OR NO PRECIP WILL BE THE RULE THROUGH DAWN OVER THE EASTERN 2/3 OF THE CWA. LARGER SHIELD OF RAIN FROM SCNTL KY SOUTH INTO THE NRN AL/GA SPREADING NE TO MOVE INTO THE WEST BY 4AM...REACHING THE PIEDMONT AROUND 8 AM. 00Z RNK SOUNDING SHOWED DEEP INVERSION THE LOW LVLS WHICH WITH STRONG LLJ SHOULD KEEP WINDS ABOVE MOST LOCATIONS FROM MIXING DOWN. STILL HIGHER TERRAIN OF THE MTN EMPIRE INTO THE NC/TN BORDER AREA COULD SEE SOME GUSTS OVER 40 MPH BY DAWN. MINOR ADJUSTMENTS MADE TO TEMPS PER LATEST OBS. LIMITED TEMPS NEAR FREEZING IN THE BATH COUNTY AREA SHOULD WARM AS MODERATE RAIN SHIELD MOVES IN LATER THIS MORNING. NOT EXPECTING ANY FROZEN/FREEZING PRECIP ISSUES THERE. PREVIOUS VALID DISCUSSION... ALL OF THE INGREDIENTS ARE IN PLACE FOR A WIDESPREAD RAINFALL EVENT INTO MONDAY MORNING AS LOW PRESSURE LIFTS NORTHEAST OUT OF THE GULF COAST STATES...THROUGH THE OHIO VALLEY AND MID APPALACHIAN REGION ON MONDAY MORNING...AND INTO NEW ENGLAND LATER MONDAY AFTERNOON INTO MONDAY NIGHT. INCREASING AND DEEPENING AREA OF ISENTROPIC LIFT IN 850-600 MILLIBAR LAYER WILL COMBINE WITH APPROACH OF RIGHT ENTRANCE REGION OF UPPER JET AND DIFFERENTIAL POSITIVE VORTICITY ADVECTION IN ADVANCE OF STRONG UPSTREAM SHORT WAVE TO RESULT IN BROAD UPWARD VERTICAL MOTIONS FIELDS THROUGH INCREASINGLY SATURATED MID AND LOWER TROPOSPHERE. BEST AREA OF FORCING...UPWARD VERTICAL MOTION FIELDS...AND DEEPER MOISTURE EXPECTED TO RAPIDLY TRANSLATE NORTHEAST OF THE AREA LATE MONDAY MORNING/EARLY AFTERNOON AS SURFACE LOW PRESSURE REFLECTION RIDES UP ALONG STRONG COLD FRONT WHICH THEN SWEEPS EAST OF THE PIEDMONT COUNTIES BY LATER AFTERNOON. STRATIFORM RAIN EXPECTED TO BE REPLACED BY SHOWERY UPSLOPING SNOW SHOWERS WITH ONSET OF VERY STRONG COLD ADVECTION AND PLUMMETING TEMPERATURES IN THE MOUNTAINS AS THE AFTERNOON PROGRESSES. EAST OF THE BLUE RIDGE...ONSET OF DOWNSLOPING WINDS SHOULD RESULT IN RAPID END OF RAIN FROM WEST TO EAST BEFORE NIGHTFALL IN MOST AREAS...TO BE FOLLOWED BY GRADUALLY CLEARING SKIES. POST-FRONTAL WINDS COULD BECOME STRONG ENOUGH MONDAY AFTERNOON TO WARRANT ADVISORY LEVEL CONSIDERATION...BUT CURRENT INDICATIONS ARE THAT WINDS WILL REMAIN JUST BELOW HEADLINE LEVELS AT THE PRESENT TIME...SO WILL NOT YET BE POSTED. REGARDLESS...MODERATE GUSTY WINDS AND FALLING TEMPERATURES WILL LIKELY DRIVE DOWN WIND CHILLS INTO THE TEENS BY LATE IN THE DAY...AND SOME PREFERRED UPSLOPE AREAS MAY EXPERIENCE AN INCH OR SO OF SNOW BY NIGHTFALL...ESPECIALLY IN WESTERN GREENBRIER COUNTY. AS WOULD BE EXPECTED...NON-DIURNAL TEMPERATURE TRENDS WILL POSE A SIGNIFICANT FORECAST CHALLENGE THROUGH THE NEAR-TERM PERIOD...ESPECIALLY OVER THE SOUTHEASTERN COUNTIES WHICH COULD EXPERIENCE A TEMPERATURE BUST ON MONDAY IF THE COOL WEDGE ERODES PRIOR TO THE ARRIVAL OF THE STRONG COLD FRONT...AND ACROSS THE WESTERN MOUNTAINS...WHERE TIMING FOR THE ARRIVAL OF THE STRONG COLD FRONT MAY ALSO RESULT IN A FORECAST BUST. TEMPERATURES WILL BE WARMER THAN CURRENTLY FORECAST WITH A LATE FRONTAL ARRIVAL IN THE SOUTHEAST...AND WILL BE COLDER THAN CURRENTLY FORECAST IF THE FRONT CAN SNEAK INTO THE WESTERN COUNTIES AN HOUR OR TWO EARLIER THAN CURRENTLY PROJECTED. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... AS OF 315 PM EST SUNDAY... THE PARENT SURFACE LOW WHICH WILL BRING RAIN TO THE AREA MONDAY WILL TRACK TO NEW ENGLAND BY MONDAY EVENING. THE FRONT ASSOCIATED WITH THIS SYSTEM WILL BE ALONG THE EASTERN SHORE WITH A POTENT ARCTIC AIRMASS SPILLING INTO THE REGION INTO TUESDAY NIGHT. PRESSURE RISES IMMEDIATELY BEHIND THE FRONT AND A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE REGION THROUGH THE DAY TUESDAY. WINDY/GUSTY CONDITIONS WILL MAKE FOR A BLUSTERY 24-36 HOUR PERIOD STARTING MONDAY NIGHT. TEMPERATURES MONDAY NIGHT WILL DROP INTO THE 10F-20F RANGE ACROSS THE MOUNTAINS WITH EARLY TUESDAY MORNING WIND CHILLS RANGING FROM BELOW ZERO IN THE HIGHER ELEVATIONS TO ABOVE ZERO SINGLE DIGITS IN MOUNTAIN VALLEYS. NOT MUCH OF A WARM-UP TUESDAY AS THE MOUNTAINS WILL NOT MAKE THE FREEZING MARK. VERY COLD TEMPERATURES FOR MID NOVEMBER ALSO EXPECTED IN THE EAST...ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES. MONDAY NIGHT TEMPERATURES WILL BE IN THE 20S WITH TUESDAY MORNING WIND CHILLS IN THE MID TEENS TO LOWER 20S. AS THE WIND RELAXES TUESDAY AFTERNOON...THE EAST WILL WARM INTO THE 30S. TUESDAY NIGHT WILL ALSO BE A VERY COLD NIGHT WITH TEMPERATURES ACROSS THE AREA RANGING FROM THE SINGLE DIGITS IN THE HIGHER ELEVATIONS TO THE UPPER TEENS ACROSS THE PIEDMONT. WINDS WILL BE LESS OF AN ISSUE TUESDAY NIGHT BUT WIND CHILLS WILL AGAIN BE COLD WITH SINGLE DIGITS IN THE WEST TO TEENS IN THE EAST. A WARM FRONT WILL PASS OVER THE REGION WEDNESDAY. TEMPERATURES WILL MODERATE INTO THE 30S WEST TO 40S EAST. DESPITE THE MILD TEMPERATURES ENTER THE REGION WEDNESDAY...AFTERNOON HIGHS WILL STILL RUN 20F COLDER THAN NORMAL. ACCUMULATING SNOW IS LIKELY FOR WESTERN SLOPES MONDAY NIGHT INTO TUESDAY. TRAJECTORIES FROM THE GREAT LAKES IS NOT IDEAL. WESTERN GREENBRIER COULD SEE 2-3 INCHES OF SNOW BY TUESDAY EVENING...1-2 INCHES AROUND BLUEFIELD. OUTSIDE OF WESTERN SLOPES...A DUSTING TO A HALF OF AN INCH IF SNOW BANDS FORM. MORE THAN NOT...24-36 HOURS OF MOUNTAIN FLURRIES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 400 PM EST SUNDAY... MANY CHANGES TO CONSIDER THROUGH THE LONG TERM PERIODS. FIRST...MOST OF THE MODELS HAVE COME INTO AGREEMENT IN SHOWING YET ANOTHER SURGE OF ARCTIC AIR TO INVADE THE REGION WED NIGHT INTO THURSDAY. THIS WAS NOT ADVERTISED A FEW RUNS BACK...BUT GIVEN GENERAL CONSENSUS AMONG THE MODELS AND A PREVAILING MEAN DEEP MERIDIONAL TROUGH ACROSS THE EASTERN HALF OF THE U.S...THIS APPEARS TO BE A REASONABLE SOLUTION AND THUS WILL LEAN IN THIS DIRECTION. HOWEVER...IN TERMS OF INTENSITY...THIS FINAL ARCTIC SURGE WILL NOT EVEN COME CLOSE TO THE ONE EARLIER IN THE WEEK. MOISTURE IS LIMITED...BUT SLIGHT CHC TO LOW CHC POPS FOR UPSLOPE -SHSN ACROSS THE USUAL WESTERN UPSLOPE AREAS OF THE ALLEGHANYS SEEMS REASONABLE AND HAVE BEEN INCLUDED...WITH NO MENTION OF POPS EAST OF THE ALLEGHANY FRONT. THE PARENT ARCTIC HIGH WILL SETTLE OVER THE REGION EARLY SATURDAY...SO BELOW NORMAL TEMPERATURES SHOULD REMAIN IN PLACE THROUGH SAT MORNING. MODEL TEMPS IN REASONABLE AGREEMENT THROUGH FRI...BUT FEEL THE GFS MOS IS TOO QUICK TO SPREAD WARMER RETURN FLOW INTO THE REGION SAT...SO LEANED TOWARD THE COLDER ECMWF MOS. BIGGER QUESTIONS REMAIN FOR THE REMAINDER OF THE EXTENDED PERIODS. AS THE ARCTIC HIGH RETREATS TOWARD THE COAST SAT...THE LONG AWAITED RETURN TO A LESS AMPLIFIED FLOW PATTERN BEGINS TO EVOLVE. THE EASTERN U.S. TROUGH IS REPLACED BY A SHORT WAVE RIDGE AS BROAD MEAN TROUGHING RELOCATES TO THE WESTERN/CENTRAL U.S. THE MAIN CONCERN FOR THE WEEKEND IS THE TIMING AND ASSOCIATED WARMING/MOISTENING WITH A STRONG NEGATIVELY TITLED HIGHLY PROGRESSIVE SHORT WAVE PROGGED TO EJECT OUT OF THE BASE OF THE MEAN TROUGH INTO THE SOUTHEAST STATES SAT NIGHT-SUN. 12Z ECMWF IN EXCELLENT AGREEMENT WITH 12Z GFS IN BRINGING THIS SYSTEM THROUGH OUR REGION SUN AFTERNOON. SUPERBLEND POPS WERE LIKELY TO CATEGORICAL SUN NIGHT-MON. GIVEN THE ASSOCIATED PVA...AND AMOUNT OF MOIST/WARM ADVECTION INTO THE REGION...THIS SEEMED REASONABLE. HOWEVER...NEIGHBORING OFFICES WERE NOT ON BOARD WITH THESE HIGH VALUES THIS FAR OUT...SO STOPPED AT A MORE REASONABLE 50 PERCENT VALUE FOR NOW. GIVEN RECENT MODEL RUN-TO-RUN VARIATION...THAT SEEMED REASONABLE FOR SURE. A SIGNIFICANT WARM UP WILL ENSUE SAT- SUN...BUT AS NOTED ABOVE...PERHAPS NOT TO THE DEGREE ADVERTISED BY THE MEX MOS. THUS...HAVE USED A MODEL BLEND FOR SAT- SUN. AN EVEN MORE SIGNIFICANT NEGATIVELY TILTED UPPER TROUGH APPEARS ON TRACK FOR THE REGION INTO MON. ECMWF/GFS SHOWING SOME INCREDIBLY WARM/MOIST AIR FOR THIS TIME OF YEAR SPREADING INTO THE REGION FROM THE SOUTH BY MON MORNING ON THE HEELS A STRONG LOW-LEVEL SOUTHERLY JET WITH DEWPOINTS APPROACHING 60 DEGREES BY MON AFTERNOON ACROSS THE PIEDMONT AND SOUTHSIDE. PROGGED LIFTED INDICES AND CAPES ALONG WITH EVIDENT SHEAR SUGGEST SOME -TSRA MAY NEED TO BE CONSIDERED BY MON AFTERNOON ACROSS THE PIEDMONT. TO SAY THE LEAST...EARLY NEXT WEEK WILL BE IN SHARP CONTRAST TO THE WEATHER EXPECTED THIS WEEK WITH TEMPERATURES ACTUALLY ABOVE SEASONAL NORMALS...ESPECIALLY IF LOWS ARE ONLY IN THE 50S MON MORNING WITH HIGHS IN THE 60S. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 1150 PM EST SUNDAY... ANOTHER LARGE AREA OF LIGHT TO MODERATE RAIN WILL CROSS THE REGION BETWEEN 08Z/3AM AND 15Z/10AM BASED ON THE LATEST HRRR AND LOCAL WRF MODELS. HIGH CONFIDENCE THAT CEILINGS WILL DROP TO IFR AS THIS RAIN MOVES IN. VISIBILITIES WILL LOWER TO MVFR WITH THE RAIN. SLEET...WHICH IS REPORTED AS U P...UNKNOWN PRECIPITATION...BY AWOS AND ASOS SENSORS IS FALLING AT KLWB. HOWEVER...WARMER AIR IS GRADUALLY ADVECTING INTO THE REGION. LITTLE DROP IN TEMPERATURE IS EXPECTED FOR THE REST OF THE NIGHT. THE SLEET AT KLWB WILL END BY MIDNIGHT WITH LITTLE TO NO ACCUMULATIONS. LOW PRESSURE OVER LOUISIANA WILL MOVE INTO THE OHIO VALLEY BY MORNING THEN WILL PUSH A STRONG COLD FRONT THROUGH THE REGION. WITH THE ARRIVAL OF THE STRONG COLD FRONT AND DOWNSLOPING WINDS CONDITIONS RETURN BACK TO VFR EAST OF THE BLUE RIDGE ON MONDAY AFTERNOON AS RAIN ENDS FROM THE WEST. BUT STRONG COLD ADVECTION AND UPSLOPE CLOUDS EXPECTED TO PERSIST WEST OF THE BLUE RIDGE WITH A PROLONGED PERIOD OF MVFR TO OCCASIONALLY IFR WEATHER IN SCATTERED SNOW SHOWERS LATER MONDAY AFTERNOON. A STRONG LOW LEVEL JET OF 50-70 KNOTS DEVELOPS OVER THE AREA TOWARD DAYBREAK. HAVE ADDED LOW LEVEL WIND SHEAR IN FOR THE TAFS. WIND GUSTS WILL INCREASE FROM THE NORTHWEST BEHIND THE FRONT UP 30 KNOTS BY EVENING. EXTENDED DISCUSSION... EXPECT MAINLY VFR WEATHER EAST OF THE BLUE RIDGE IN THE TUESDAY-FRIDAY. CONDITIONS WILL BECOME VFR WEST OF THE BLUE RIDGE UNDER SURFACE HIGH PRESSURE WEDNESDAY...BUT ANOTHER PERIOD OF UPSLOPING CLOUDS WILL BRING MVFR CONDITIONS THURSDAY AFTERNOON INTO FRIDAY AS NEXT COLD FRONT MOVES THROUGH THE AREA. && .HYDROLOGY... AS OF 105 PM EST SUNDAY... FORECAST PRECIPITATION FOR THE UPCOMING EVENT STILL EXPECTED TO RANGE FROM ABOUT ONE-HALF /0.50/ INCH OVER THE NORTHERN RIVER BASINS UP TO ABOUT ONE /1.25/ INCHES OVER THE SOUTHERN RIVER BASINS BY THE TIME IT ENDS LATE MONDAY. THE RAINFALL IS NEEDED AS PRECIPITATION IN NOVEMBER TO DATE HAS BEEN VERY SCANTY. MOST OF THE COOP NETWORK SITES HAVE RECEIVED UNDER 0.50 INCHES FOR THE MONTH...AND SOME LESS THAN 0.25 INCHES. A SUBSTANTIAL PORTION OF THE PIEDMONT IN OUR HYDROLOGIC SERVICE AREA IS ALREADY IN THE ABNORMALLY DRY CATEGORY ON THE WEEKLY U.S. DROUGHT MONITOR...WITH RAINFALL DEFICITS OF 2 TO 4 INCHES OVER THE PAST 60 DAYS. THE DRY PERIOD IS REFLECTED IN DECLINING STREAM FLOWS AS MONITORED BY THE USGS STREAM GAGING NETWORK AND ALSO BY FALLING RESERVOIR STORAGE. && .CLIMATE... AS OF 315 PM EST SUNDAY... RECORD COOLEST HIGHS...TUESDAY NOV 18TH BLACKSBURG VA...30 IN 2008 BLUEFIELD WV....27 IN 2008 DANVILLE VA.....38 IN 1959 ROANOKE VA......33 IN 1951 LEWISBURG WV....30 IN 2008 LYNCHBURG VA....32 IN 1924 && .EQUIPMENT... AS OF 120 AM EST MONDAY... KFCX RADAR DOWN DUE TO TRANSMITTER FAULT. TECHNICIANS WILL WORK ON RESTORING THIS BY NOON TODAY. THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT OF SERVICE UNTIL MONDAY WHEN TECHNICIANS WILL REPLACE THE SENSOR. UNTIL THEN THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS STAFFED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...WERT/WP SHORT TERM...RCS LONG TERM...RAB AVIATION...AMS/WERT HYDROLOGY...PC/WERT/WP CLIMATE...RCS EQUIPMENT...WERT/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1151 PM EST SUN NOV 16 2014 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL LIFT NORTHEAST OUT OF THE GULF COAST STATES TONIGHT...AND MOVE THROUGH VIRGINIA AND ADJACENT STATES ON MONDAY MORNING. THIS SYSTEM WILL BE PRECEDED AND ACCOMPANIED BY WIDESPREAD LIGHT TO MODERATE RAIN. A STRONG COLD FRONT WILL THEN SWEEP EAST THOUGH THE AREA ON MONDAY AFTERNOON...BRINGING ANOTHER ROUND OF VERY COLD TEMPERATURES WITH GUSTY WINDS FOR MONDAY NIGHT INTO TUESDAY...ALONG WITH SOME MOUNTAIN SNOW SHOWERS. && .NEAR TERM /THROUGH MONDAY/... AS OF 315 PM EST SUNDAY... ALL OF THE INGREDIENTS ARE IN PLACE FOR A WIDESPREAD RAINFALL EVENT TONIGHT INTO MONDAY MORNING AS LOW PRESSURE LIFTS NORTHEAST OUT OF THE GULF COAST STATES...THROUGH THE OHIO VALLEY AND MID APPALACHIAN REGION ON MONDAY MORNING...AND INTO NEW ENGLAND LATER MONDAY AFTERNOON INTO MONDAY NIGHT. INCREASING AND DEEPENING AREA OF ISENTROPIC LIFT IN 850-600 MILLIBAR LAYER WILL COMBINE WITH APPROACH OF RIGHT ENTRANCE REGION OF UPPER JET AND DIFFERENTIAL POSITIVE VORTICITY ADVECTION IN ADVANCE OF STRONG UPSTREAM SHORT WAVE TO RESULT IN BROAD UPWARD VERTICAL MOTIONS FIELDS THROUGH INCREASINGLY SATURATED MID AND LOWER TROPOSPHERE. LIGHT RAIN IN ADVANCE OF THE SYSTEM HAS ALREADY BEGUN...OR WAS IN THE PROCESS OF BEGINNING FROM THE NW NC MOUNTAINS NORTH THROUGH PORTIONS OF THE NEW RIVER VALLEY INTO THE ALLEGHANY HIGHLANDS OF VA...WEST INTO THE SE WV COUNTIES. PRECIPITATION IS EXPECTED TO CONTINUE TO OVERSPREAD THE PIEDMONT COUNTIES BY/DURING THE EARLY- MID EVENING HOURS. ONSET OF PRECIPITATION IS WET-BULBING TEMPERATURES BACK DOWN INTO THE 30S IN THE MOUNTAINS...AND WILL DRIVE TEMPERATURES BACK DOWN TO AROUND 40F ACROSS THE PIEDMONT WHEN IT BEGINS...WITH TEMPERATURES THEN LIKELY TO FLATLINE FOR THE REST OF THE NIGHT AS WARM ADVECTION CONTINUES AND INCREASES OVER INVERSION LAYER. A BRIEF PERIOD OF SLEET IS EVEN POSSIBLE AT THE ONSET OF THE EVENT...ESPECIALLY IN AREAS NORTH OF INTERSTATE 64...BUT NO ACCUMULATIONS ARE EXPECTED CONSIDERING TEMPERATURES ARE EXPECTED TO REMAIN ABOVE FREEZING DESPITE WET-BULB INFLUENCES. STRENGTH OF INVERSION LIKELY TO BE OF SUFFICIENT DEPTH TO LIMIT/HINDER WINDS UNDER DEVELOPING LOW LEVEL JET OF 40-50 KNOTS LATER TONIGHT INTO MONDAY MORNING FROM PENETRATING DOWN TO SURFACE...EVEN ACROSS THE HIGHER TERRAIN. BEST AREA OF FORCING...UPWARD VERTICAL MOTION FIELDS...AND DEEPER MOISTURE EXPECTED TO RAPIDLY TRANSLATE NORTHEAST OF THE AREA LATE MONDAY MORNING/EARLY AFTERNOON AS SURFACE LOW PRESSURE REFLECTION RIDES UP ALONG STRONG COLD FRONT WHICH THEN SWEEPS EAST OF THE PIEDMONT COUNTIES BY LATER AFTERNOON. STRATIFORM RAIN EXPECTED TO BE REPLACED BY SHOWERY UPSLOPING SNOW SHOWERS WITH ONSET OF VERY STRONG COLD ADVECTION AND PLUMMETING TEMPERATURES IN THE MOUNTAINS AS THE AFTERNOON PROGRESSES. EAST OF THE BLUE RIDGE...ONSET OF DOWNSLOPING WINDS SHOULD RESULT IN RAPID END OF RAIN FROM WEST TO EAST BEFORE NIGHTFALL IN MOST AREAS...TO BE FOLLOWED BY GRADUALLY CLEARING SKIES. POST-FRONTAL WINDS COULD BECOME STRONG ENOUGH MONDAY AFTERNOON TO WARRANT ADVISORY LEVEL CONSIDERATION...BUT CURRENT INDICATIONS ARE THAT WINDS WILL REMAIN JUST BELOW HEADLINE LEVELS AT THE PRESENT TIME...SO WILL NOT YET BE POSTED. REGARDLESS...MODERATE GUSTY WINDS AND FALLING TEMPERATURES WILL LIKELY DRIVE DOWN WIND CHILLS INTO THE TEENS BY LATE IN THE DAY...AND SOME PREFERRED UPSLOPE AREAS MAY EXPERIENCE AN INCH OR SO OF SNOW BY NIGHTFALL...ESPECIALLY IN WESTERN GREENBRIER COUNTY. AS WOULD BE EXPECTED...NON-DIURNAL TEMPERATURE TRENDS WILL POSE A SIGNIFICANT FORECAST CHALLENGE THROUGH THE NEAR-TERM PERIOD...ESPECIALLY OVER THE SOUTHEASTERN COUNTIES WHICH COULD EXPERIENCE A TEMPERATURE BUST ON MONDAY IF THE COOL WEDGE ERODES PRIOR TO THE ARRIVAL OF THE STRONG COLD FRONT...AND ACROSS THE WESTERN MOUNTAINS...WHERE TIMING FOR THE ARRIVAL OF THE STRONG COLD FRONT MAY ALSO RESULT IN A FORECAST BUST. TEMPERATURES WILL BE WARMER THAN CURRENTLY FORECAST WITH A LATE FRONTAL ARRIVAL IN THE SOUTHEAST...AND WILL BE COLDER THAN CURRENTLY FORECAST IF THE FRONT CAN SNEAK INTO THE WESTERN COUNTIES AN HOUR OR TWO EARLIER THAN CURRENTLY PROJECTED. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... AS OF 315 PM EST SUNDAY... THE PARENT SURFACE LOW WHICH WILL BRING RAIN TO THE AREA MONDAY WILL TRACK TO NEW ENGLAND BY MONDAY EVENING. THE FRONT ASSOCIATED WITH THIS SYSTEM WILL BE ALONG THE EASTERN SHORE WITH A POTENT ARCTIC AIRMASS SPILLING INTO THE REGION INTO TUESDAY NIGHT. PRESSURE RISES IMMEDIATELY BEHIND THE FRONT AND A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE REGION THROUGH THE DAY TUESDAY. WINDY/GUSTY CONDITIONS WILL MAKE FOR A BLUSTERY 24-36 HOUR PERIOD STARTING MONDAY NIGHT. TEMPERATURES MONDAY NIGHT WILL DROP INTO THE 10F-20F RANGE ACROSS THE MOUNTAINS WITH EARLY TUESDAY MORNING WIND CHILLS RANGING FROM BELOW ZERO IN THE HIGHER ELEVATIONS TO ABOVE ZERO SINGLE DIGITS IN MOUNTAIN VALLEYS. NOT MUCH OF A WARM-UP TUESDAY AS THE MOUNTAINS WILL NOT MAKE THE FREEZING MARK. VERY COLD TEMPERATURES FOR MID NOVEMBER ALSO EXPECTED IN THE EAST...ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES. MONDAY NIGHT TEMPERATURES WILL BE IN THE 20S WITH TUESDAY MORNING WIND CHILLS IN THE MID TEENS TO LOWER 20S. AS THE WIND RELAXES TUESDAY AFTERNOON...THE EAST WILL WARM INTO THE 30S. TUESDAY NIGHT WILL ALSO BE A VERY COLD NIGHT WITH TEMPERATURES ACROSS THE AREA RANGING FROM THE SINGLE DIGITS IN THE HIGHER ELEVATIONS TO THE UPPER TEENS ACROSS THE PIEDMONT. WINDS WILL BE LESS OF AN ISSUE TUESDAY NIGHT BUT WIND CHILLS WILL AGAIN BE COLD WITH SINGLE DIGITS IN THE WEST TO TEENS IN THE EAST. A WARM FRONT WILL PASS OVER THE REGION WEDNESDAY. TEMPERATURES WILL MODERATE INTO THE 30S WEST TO 40S EAST. DESPITE THE MILD TEMPERATURES ENTER THE REGION WEDNESDAY...AFTERNOON HIGHS WILL STILL RUN 20F COLDER THAN NORMAL. ACCUMULATING SNOW IS LIKELY FOR WESTERN SLOPES MONDAY NIGHT INTO TUESDAY. TRAJECTORIES FROM THE GREAT LAKES IS NOT IDEAL. WESTERN GREENBRIER COULD SEE 2-3 INCHES OF SNOW BY TUESDAY EVENING...1-2 INCHES AROUND BLUEFIELD. OUTSIDE OF WESTERN SLOPES...A DUSTING TO A HALF OF AN INCH IF SNOW BANDS FORM. MORE THAN NOT...24-36 HOURS OF MOUNTAIN FLURRIES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 400 PM EST SUNDAY... MANY CHANGES TO CONSIDER THROUGH THE LONG TERM PERIODS. FIRST...MOST OF THE MODELS HAVE COME INTO AGREEMENT IN SHOWING YET ANOTHER SURGE OF ARCTIC AIR TO INVADE THE REGION WED NIGHT INTO THURSDAY. THIS WAS NOT ADVERTISED A FEW RUNS BACK...BUT GIVEN GENERAL CONSENSUS AMONG THE MODELS AND A PREVAILING MEAN DEEP MERIDIONAL TROUGH ACROSS THE EASTERN HALF OF THE U.S...THIS APPEARS TO BE A REASONABLE SOLUTION AND THUS WILL LEAN IN THIS DIRECTION. HOWEVER...IN TERMS OF INTENSITY...THIS FINAL ARCTIC SURGE WILL NOT EVEN COME CLOSE TO THE ONE EARLIER IN THE WEEK. MOISTURE IS LIMITED...BUT SLIGHT CHC TO LOW CHC POPS FOR UPSLOPE -SHSN ACROSS THE USUAL WESTERN UPSLOPE AREAS OF THE ALLEGHANYS SEEMS REASONABLE AND HAVE BEEN INCLUDED...WITH NO MENTION OF POPS EAST OF THE ALLEGHANY FRONT. THE PARENT ARCTIC HIGH WILL SETTLE OVER THE REGION EARLY SATURDAY...SO BELOW NORMAL TEMPERATURES SHOULD REMAIN IN PLACE THROUGH SAT MORNING. MODEL TEMPS IN REASONABLE AGREEMENT THROUGH FRI...BUT FEEL THE GFS MOS IS TOO QUICK TO SPREAD WARMER RETURN FLOW INTO THE REGION SAT...SO LEANED TOWARD THE COLDER ECMWF MOS. BIGGER QUESTIONS REMAIN FOR THE REMAINDER OF THE EXTENDED PERIODS. AS THE ARCTIC HIGH RETREATS TOWARD THE COAST SAT...THE LONG AWAITED RETURN TO A LESS AMPLIFIED FLOW PATTERN BEGINS TO EVOLVE. THE EASTERN U.S. TROUGH IS REPLACED BY A SHORT WAVE RIDGE AS BROAD MEAN TROUGHING RELOCATES TO THE WESTERN/CENTRAL U.S. THE MAIN CONCERN FOR THE WEEKEND IS THE TIMING AND ASSOCIATED WARMING/MOISTENING WITH A STRONG NEGATIVELY TITLED HIGHLY PROGRESSIVE SHORT WAVE PROGGED TO EJECT OUT OF THE BASE OF THE MEAN TROUGH INTO THE SOUTHEAST STATES SAT NIGHT-SUN. 12Z ECMWF IN EXCELLENT AGREEMENT WITH 12Z GFS IN BRINGING THIS SYSTEM THROUGH OUR REGION SUN AFTERNOON. SUPERBLEND POPS WERE LIKELY TO CATEGORICAL SUN NIGHT-MON. GIVEN THE ASSOCIATED PVA...AND AMOUNT OF MOIST/WARM ADVECTION INTO THE REGION...THIS SEEMED REASONABLE. HOWEVER...NEIGHBORING OFFICES WERE NOT ON BOARD WITH THESE HIGH VALUES THIS FAR OUT...SO STOPPED AT A MORE REASONABLE 50 PERCENT VALUE FOR NOW. GIVEN RECENT MODEL RUN-TO-RUN VARIATION...THAT SEEMED REASONABLE FOR SURE. A SIGNIFICANT WARM UP WILL ENSUE SAT- SUN...BUT AS NOTED ABOVE...PERHAPS NOT TO THE DEGREE ADVERTISED BY THE MEX MOS. THUS...HAVE USED A MODEL BLEND FOR SAT- SUN. AN EVEN MORE SIGNIFICANT NEGATIVELY TILTED UPPER TROUGH APPEARS ON TRACK FOR THE REGION INTO MON. ECMWF/GFS SHOWING SOME INCREDIBLY WARM/MOIST AIR FOR THIS TIME OF YEAR SPREADING INTO THE REGION FROM THE SOUTH BY MON MORNING ON THE HEELS A STRONG LOW-LEVEL SOUTHERLY JET WITH DEWPOINTS APPROACHING 60 DEGREES BY MON AFTERNOON ACROSS THE PIEDMONT AND SOUTHSIDE. PROGGED LIFTED INDICES AND CAPES ALONG WITH EVIDENT SHEAR SUGGEST SOME -TSRA MAY NEED TO BE CONSIDERED BY MON AFTERNOON ACROSS THE PIEDMONT. TO SAY THE LEAST...EARLY NEXT WEEK WILL BE IN SHARP CONTRAST TO THE WEATHER EXPECTED THIS WEEK WITH TEMPERATURES ACTUALLY ABOVE SEASONAL NORMALS...ESPECIALLY IF LOWS ARE ONLY IN THE 50S MON MORNING WITH HIGHS IN THE 60S. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 1150 PM EST SUNDAY... ANOTHER LARGE AREA OF LIGHT TO MODERATE RAIN WILL CROSS THE REGION BETWEEN 08Z/3AM AND 15Z/10AM BASED ON THE LATEST HRRR AND LOCAL WRF MODELS. HIGH CONFIDENCE THAT CEILINGS WILL DROP TO IFR AS THIS RAIN MOVES IN. VISIBILITIES WILL LOWER TO MVFR WITH THE RAIN. SLEET...WHICH IS REPORTED AS U P...UNKNOWN PRECIPITATION...BY AWOS AND ASOS SENSORS IS FALLING AT KLWB. HOWEVER...WARMER AIR IS GRADUALLY ADVECTING INTO THE REGION. LITTLE DROP IN TEMPERATURE IS EXPECTED FOR THE REST OF THE NIGHT. THE SLEET AT KLWB WILL END BY MIDNIGHT WITH LITTLE TO NO ACCUMULATIONS. LOW PRESSURE OVER LOUISIANA WILL MOVE INTO THE OHIO VALLEY BY MORNING THEN WILL PUSH A STRONG COLD FRONT THROUGH THE REGION. WITH THE ARRIVAL OF THE STRONG COLD FRONT AND DOWNSLOPING WINDS CONDITIONS RETURN BACK TO VFR EAST OF THE BLUE RIDGE ON MONDAY AFTERNOON AS RAIN ENDS FROM THE WEST. BUT STRONG COLD ADVECTION AND UPSLOPE CLOUDS EXPECTED TO PERSIST WEST OF THE BLUE RIDGE WITH A PROLONGED PERIOD OF MVFR TO OCCASIONALLY IFR WEATHER IN SCATTERED SNOW SHOWERS LATER MONDAY AFTERNOON. A STRONG LOW LEVEL JET OF 50-70 KNOTS DEVELOPS OVER THE AREA TOWARD DAYBREAK. HAVE ADDED LOW LEVEL WIND SHEAR IN FOR THE TAFS. WIND GUSTS WILL INCREASE FROM THE NORTHWEST BEHIND THE FRONT UP 30 KNOTS BY EVENING. EXTENDED DISCUSSION... EXPECT MAINLY VFR WEATHER EAST OF THE BLUE RIDGE IN THE TUESDAY-FRIDAY. CONDITIONS WILL BECOME VFR WEST OF THE BLUE RIDGE UNDER SURFACE HIGH PRESSURE WEDNESDAY...BUT ANOTHER PERIOD OF UPSLOPING CLOUDS WILL BRING MVFR CONDITIONS THURSDAY AFTERNOON INTO FRIDAY AS NEXT COLD FRONT MOVES THROUGH THE AREA. && .HYDROLOGY... AS OF 105 PM EST SUNDAY... FORECAST PRECIPITATION FOR THE UPCOMING EVENT STILL EXPECTED TO RANGE FROM ABOUT ONE-HALF /0.50/ INCH OVER THE NORTHERN RIVER BASINS UP TO ABOUT ONE /1.25/ INCHES OVER THE SOUTHERN RIVER BASINS BY THE TIME IT ENDS LATE MONDAY. THE RAINFALL IS NEEDED AS PRECIPITATION IN NOVEMBER TO DATE HAS BEEN VERY SCANTY. MOST OF THE COOP NETWORK SITES HAVE RECEIVED UNDER 0.50 INCHES FOR THE MONTH...AND SOME LESS THAN 0.25 INCHES. A SUBSTANTIAL PORTION OF THE PIEDMONT IN OUR HYDROLOGIC SERVICE AREA IS ALREADY IN THE ABNORMALLY DRY CATEGORY ON THE WEEKLY U.S. DROUGHT MONITOR...WITH RAINFALL DEFICITS OF 2 TO 4 INCHES OVER THE PAST 60 DAYS. THE DRY PERIOD IS REFLECTED IN DECLINING STREAM FLOWS AS MONITORED BY THE USGS STREAM GAGING NETWORK AND ALSO BY FALLING RESERVOIR STORAGE. && .CLIMATE... AS OF 315 PM EST SUNDAY... RECORD COOLEST HIGHS...TUESDAY NOV 18TH BLACKSBURG VA...30 IN 2008 BLUEFIELD WV....27 IN 2008 DANVILLE VA.....38 IN 1959 ROANOKE VA......33 IN 1951 LEWISBURG WV....30 IN 2008 LYNCHBURG VA....32 IN 1924 && .EQUIPMENT... AS OF 650 PM EST SUNDAY... THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT OF SERVICE UNTIL MONDAY WHEN TECHNICIANS WILL REPLACE THE SENSOR. UNTIL THEN THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS STAFFED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...WERT SHORT TERM...RCS LONG TERM...RAB AVIATION...AMS/WERT HYDROLOGY...PC/WERT/WP CLIMATE...RCS EQUIPMENT...WERT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
252 PM CST MON NOV 17 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 143 PM CST MON NOV 17 2014 CHALLENGES INCLUDE LINGERING LIGHT SNOW SHOWERS/FLURRIES AND BLOWING SNOW THIS EVENING...FOLLOWED BY LIGHT ACCUMULATING SNOW TUESDAY NIGHT INTO WEDNESDAY MORNING AND THEN UNSEASONABLE COLD CONTINUING THROUGH FRIDAY. 17.12Z GLOBAL MODELS ARE IN GOOD AGREEMENT THROUGH 22.00Z (FRIDAY NIGHT)...DIVERGING INTO THE WEEKEND WITH THE TRACK AND EVOLUTION OF A STRONG EAST-PACIFIC WAVE AS IT EJECTS FROM THE SOUTHERN PLAINS INTO THE UPPER MIDWEST. FOR TONIGHT...LIGHT SNOW SHOWERS/FLURRIES IN COLD CYCLONIC FLOW ALOFT WILL DISSIPATE BY MIDNIGHT WITH NO MORE THAN A COUPLE TENTHS OF ACCUMULATION. BLOWING/DRIFTING SNOW ALSO EXPECTED TO SUBSIDE AFTER SUNSET. WITH ARCTIC AIR MASS FULLY IN PLACE AND AFTERNOON HIGHS TODAY ONLY REACHING THE MID TEENS...EXPECT LOWS TO EASILY DROP INTO THE SINGLE DIGITS ABOVE ZERO AND EVEN FAVORED COLD SPOTS A FEW DEGREES BELOW ZERO. 17.18Z RAP SHOWS 0.5 KM WINDS OVERNIGHT AROUND 30 KTS WITH A NEARLY DRY ADIABATIC BOUNDARY LAYER TO THIS LEVEL...SO EXPECT A BREEZY NIGHT WITH WESTERLY WINDS FROM 10 TO 15 MPH. THIS WILL RESULT IN WIND CHILL VALUES BY TUESDAY MORNING FROM 10 TO 20 BELOW ZERO. THE REST OF TUESDAY WILL BE MOSTLY CLOUDY BUT DRY AND BREEZY WITH AFTERNOON HIGHS SIMILAR TO TODAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 143 PM CST MON NOV 17 2014 THE NEXT SHORT-WAVE ALOFT ROTATES THROUGH THE UPPER MISSISSIPPI RIVER VALLEY TUESDAY NIGHT. 850 TO 600 HPA FORCING INCREASES ALONG WARM FRONTAL BOUNDARY AND WITH AROUND 4 UBAR/S OF OMEGA CENTERED ALONG THE DENDRITIC GROWTH ZONE...EXPECT A QUICK ONE INCH OR LESS OF ACCUMULATION MAINLY ALONG AND EAST OF THE MISSISSIPPI RIVER. INCREASED POPS INTO THE LIKELY CATEGORY TUESDAY NIGHT FOR THESE AREAS. TEMPERATURES TUESDAY NIGHT WILL DROP INTO THE SINGLE DIGITS TO LOW TEENS ABOVE ZERO. REINFORCING COLD FRONT SWINGS ACROSS THE REGION EARLY WEDNESDAY MORNING...KEEPING DAILY TEMPERATURES WELL BELOW SEASONAL NORMALS THROUGH THE REST OF THE WORK WEEK. EXPECT HIGHS IN THE TEENS AND 20S AND LOWS IN THE SINGLE DIGITS AND LOW TEENS. WEDNESDAY THROUGH FRIDAY WILL BE DRY...HOWEVER...WITH SURFACE HIGH PRESSURE MOVING ACROSS THE NATION/S MID-SECTION. BREEZY WEST-NORTHWEST WINDS WEDNESDAY AND THURSDAY WILL BECOME LIGHT THURSDAY NIGHT INTO FRIDAY AS CENTER OF SURFACE HIGH SLIDES ACROSS IOWA AND PRESSURE GRADIENT WEAKENS. SATURDAY THROUGH MONDAY...17.12Z GFS/ECMWF IN AGREEMENT THAT AN OPEN WAVE WILL MOVE INTO THE UPPER MIDWEST FROM THE SOUTHERN PLAINS. GFS IS QUICKER AND FARTHER EAST WITH SURFACE LOW TRACK COMPARED TO THE ECMWF AND THUS LESS ROBUST WITH PRECIP ACROSS THE FORECAST AREA. THE ECMWF...HOWEVER...DEPICTS 0.75 TO 1.5 INCHES OF LIQUID PRECIP THROUGH MONDAY AS IT DRAGS A SLOW-MOVING DEFORMATION PRECIP ZONE ACROSS THE AREA. BOTH MODELS WARM ENOUGH FOR ANY PRECIP TO INITIALLY FALL AS RAIN ON SATURDAY/SUNDAY AND EVENTUALLY CHANGING OVER TO SNOW SUNDAY NIGHT INTO MONDAY. CONFIDENCE HIGH ENOUGH TO INCREASE POPS INTO THE HIGH CHANCE CATEGORY...BUT STILL LOTS OF DETAILS TO SORT OUT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1146 AM CST MON NOV 17 2014 STRONG/COLD CYCLONIC FLOW CONTINUES OVER THE AREA IN THE WAKE OF ARCTIC COLD FRONTAL PASSAGE. NOTICED KRST HAS SLIPPED DOWN TO 4SM THIS PAST HOUR. CALL TO THE TOWER INDICATED THAT SNOW WAS MAINLY DRIFTING RIGHT NOW...BUT WITH STRONGER GUSTS THIS AFTERNOON... SHOULD SEE SOME MORE BLSN DOWN TO 1SM AT TIMES. KLSE..BEING A BIT MORE SHELTERED SHOULD JUST SEE SOME LOCALIZED DRIFTING OF SNOW. OTHERWISE...COLD CYCLONIC FLOW WAS ALSO PRODUCING MVFR CLOUD COVER WITH SNOW SHOWERS. EXPECTING MVFR CLOUD CONDITIONS WITH FLURRIES TO CONTINUE RIGHT THROUGH TONIGHT INTO TUESDAY MORNING. PLAN ON GUSTINESS OF THE WINDS TO SUBSIDE GOING INTO THIS EVENING WITH LOSS OF MIXING THROUGH THE BOUNDARY LAYER. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ086- 087-094-095. IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ008- 009-018-019. && $$ SHORT TERM...ROGERS LONG TERM...ROGERS AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1134 PM CST SUN NOV 16 2014 .UPDATE... ISSUED AT 528 PM CST SUN NOV 16 2014 LOSS OF DAYTIME HEATING HAS HELPED TO REALLY CLEAR SKIES OUT BACK IN THE DAKOTAS AND PARTS OF WESTERN MN. THIS CLEARING AREA LOOKS POISED TO MOVE INTO THE REGION OVERNIGHT...SO MAY HAVE TO ADJUST SKY COVER DOWNWARDS. STILL LOOKS LIKE CLOUDS WILL GREATLY INCREASE IN THE MORNING AS THE SUN DESTABILIZES THE ATMOSPHERE UNDER THE UNSEASONABLY COLD AIR ALOFT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 158 PM CST SUN NOV 16 2014 PRIMARY CHALLENGES INCLUDE LIGHT SNOW TONIGHT THROUGH MONDAY AND STRONG NORTHWEST WINDS IN THE WAKE OF AN ARCTIC FRONT THROUGH THE DAY ON MONDAY. 16.12Z GLOBAL MODELS ARE IN GOOD AGREEMENT THROUGH 19.12Z...DIVERGING SOMEWHAT THEREAFTER IN TIMING AND STRENGTH OF SHORT-WAVES MOVING THROUGH PARENT NORTHWEST FLOW ALOFT...BECOMING MORE ZONAL BY NEXT WEEKEND. 16.20Z SURFACE ANALYSIS SHOWS A STRONG ARCTIC/COLD FRONT DRAPED FROM NEAR ROSEAU MN TO ABERDEEN SD. THIS FEATURE WILL SWEEP ACROSS THE UPPER MISSISSIPPI RIVER VALLEY OVERNIGHT...BRINGING WITH IT SCATTERED LIGHT SNOW SHOWERS AMOUNTING TO NO MORE THAN AN INCH OF ACCUMULATION AND STRONG NORTHWEST WIND IN ITS WAKE. SURFACE OBS BEHIND THE FRONT THIS AFTERNOON ACROSS ND SHOWING GUSTS IN EXCESS OF 30 KTS AND ALTHOUGH THIS AIR MASS WILL MODIFY SOMEWHAT AS IT DROPS SOUTH...16.19Z RAP BRINGS A NOSE OF 35 TO 40 KTS AT 0.5 KM INTO THE WESTERN FORECAST AREA BY MONDAY MORNING. WITH A DEEPENING WELL-MIXED BOUNDARY LAYER...THIS SHOULD RESULT IN WIDESPREAD 20 TO 25 MPH NORTHWEST WINDS WITH FREQUENT GUSTS UP TO 35 MPH. THESE WINDS COMBINED WITH 2 TO 4 INCHES OF NEW SNOWFALL FROM SUNDAY AND SUNDAY NIGHT ACROSS PORTIONS OF SOUTHEAST MN AND NORTHEAST IA WILL RESULT IN AREAS OF BLOWING AND DRIFTING SNOW... REDUCING VISIBILITY AT TIMES TO ONE HALF MILE OR LESS. WILL ISSUE A WINTER WEATHER ADVISORY FOR BLOWING SNOW FROM 17.12Z TO 18.00Z ACROSS THE WESTERN THIRD OF THE FORECAST AREA. THE COMBINATION OF POOR VISIBILITY AND BLOWING SNOW WILL CREATE DIFFICULT TRAVEL CONDITIONS FOR THE MORNING COMMUTE AND CONTINUING THROUGH MUCH OF THE DAY. OTHERWISE...MONDAY WILL BE MOSTLY CLOUDY AND COLD WITH AFTERNOON HIGHS ONLY IN THE TEENS. SCATTERED LIGHT SNOW SHOWERS WILL RESULT IN MINOR ADDITIONAL ACCUMULATIONS. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 158 PM CST SUN NOV 16 2014 850 HPA TEMPERATURES PLUNGE TO -18 C ACROSS THE FORECAST AREA BY 18.12Z (TUESDAY MORNING). THIS WILL RESULT IN THE COLDEST MORNING SO FAR THIS SEASON. TEMPERATURES WILL FALL INTO THE SINGLE DIGITS ABOVE ZERO WITH FAVORED COLD SPOTS DROPPING BELOW ZERO. COMBINED WITH WESTERLY WINDS FROM 10 TO 15 MPH...WIND CHILL VALUES WILL BE IN THE 10 TO 20 BELOW RANGE. THE REST OF TUESDAY WILL BE DRY AND SHOULD SEE SOME PEAKS OF SUNSHINE LATE IN THE DAY AS MONDAY/S SNOW MOVES OFF TO THE EAST. TEMPERATURES WILL TOP OUT IN THE MID TEENS. A REINFORCING SHOT OF ARCTIC AIR WILL DROP SOUTH TUESDAY NIGHT BEHIND THE NEXT COLD FRONT. MOST SNOW WILL FALL TO THE NORTH AND EAST NEAREST THE BEST MID-LEVEL FORCING AND HIGHEST MOISTURE... ALTHOUGH SOME SCATTERED LIGHT SNOW IS POSSIBLE ACROSS THE FORECAST AREA WITH ACCUMULATIONS LESS THAN ONE INCH. WEDNESDAY THROUGH FRIDAY WILL BE DRY AND UNSEASONABLY COLD. BROAD SURFACE HIGH PRESSURE DRIFTS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY THROUGH THIS PERIOD...CENTERED ACROSS NORTHERN MO BY 12Z FRIDAY. THE REGION REMAINS FULLY ENTRENCHED WITHIN ARCTIC AIR MASS THROUGH FRIDAY WITH DAILY HIGHS IN THE MID TEENS AND 20S AND LOWS IN THE SINGLE DIGITS TO TEENS. DEPENDING ON CLOUD COVER... THURSDAY NIGHT LOWS COULD RIVAL THOSE FROM TUESDAY MORNING. MID-LEVEL THERMAL RIDGE FINALLY MAKES SOME EASTWARD PROGRESS BY THE WEEKEND. WARM AIR ADVECTION REGIME SHOULD ALLOW TEMPERATURES TO CLIMB BACK INTO THE 30S. HOWEVER...BOTH THE 16.12Z GFS AND ECMWF SHOW THE NEXT STORM SYSTEM LIFTING NORTH FROM THE SOUTHERN PLAINS OVER THE WEEKEND. THE ECMWF IS FARTHER WEST WITH ITS PRECIP THAN THE GFS...SO FOR NOW WILL FOLLOW A BLENDED APPROACH WITH 20 TO 30 POPS AND THE POTENTIAL FOR MIXED PRECIP GIVEN WARMER TEMPERATURES ALOFT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1134 PM CST SUN NOV 16 2014 CONDITIONS FOR THE MOST PART AROUND THE TAF SITES AS WELL AS IN THE DAKOTAS AND MN ARE IN THE VFR RANGE...IN THE WAKE OF A COLD FRONT PASSING THROUGH THE TAF SITES. THERE ARE A FEW ISOLATED POCKETS OF MVFR STRATUS...MAINLY IN NORTHERN MN. ANTICIPATING CONDITIONS TO STAY VFR EARLY THIS MORNING...THEN AN MVFR DECK DEVELOP AROUND OR SHORTLY AFTER 12Z AT BOTH TAF SITES AS THE AIRMASS BEGINS TO DESTABILIZE. BY 14Z...SOME SNOW SHOWERS SHOULD GET GOING...AND WITH NORTHWEST WINDS INCREASING TO 15-20 KT WITH GUSTS OF 20-30 KT...BLOWING SNOW APPEARS LIKELY TO OCCUR AT RST. THAT BLOWING SNOW SHOULD REDUCE VISIBILITIES TO MVFR...AND POSSIBLY BRIEFLY IFR AT TIMES BUT PINNING WHEN IS UNCERTAIN AT THIS TIME. CEILINGS AND VISIBILITIES SHOULD BOTH IMPROVE LATE IN THE DAY DUE TO LOSS OF DAYTIME HEATING. HAVE KEPT MVFR TO VFR CEILINGS GOING INTO THE EVENING HOURS...THOUGH ITS ENTIRELY POSSIBLE THE CLOUDS DISSIPATE TOO WITH LOSS OF HEATING. THE AFOREMENTIONED WINDS DO LOOK TO PERSIST THROUGH THE EVENING... THOUGH...AS ARCTIC AIR CONTINUES TO FLOW INTO THE TAF SITES WITH A TIGHT PRESSURE GRADIENT IN PLACE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST MONDAY FOR MNZ086- 087-094-095. IA...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST MONDAY FOR IAZ008- 009-018-019. && $$ UPDATE...AJ SHORT TERM...ROGERS LONG TERM...ROGERS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
412 AM EST WED NOV 19 2014 ...A WIDESPREAD FREEZE REACHES THE BEACHES OF SOUTH COASTAL SOUTH CAROLINA AND NORTH COASTAL GEORGIA THIS MORNING WITH RECORD LOWS LIKELY... .SYNOPSIS... HIGH PRESSURE WILL EXTEND ACROSS THE AREA THROUGH THE WEEKEND. THE HIGH WILL THEN MOVE OFF THE EAST COAST SATURDAY AHEAD OF A WARM FRONT THAT SHIFTS OVER THE REGION SUNDAY. A COLD FRONT WILL SHIFT THROUGH THE AREA LATE MONDAY...FOLLOWED BY HIGH PRESSURE INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... THROUGH SUNRISE...FREEZING TEMPERATURES HAVE MADE IT ALL THE WAY TO THE BEACHES EARLY THIS MORNING WITH ONLY A VERY TINY AREA FROM HILTON HEAD TO TYBEE ISLAND REMAINING A DEG OR TWO ABOVE THE FREEZING MARK AS OF 19/08Z. EVEN MERIDIAN/SAPELO ISLAND AND SAINT SIMMONS HAVE DROPPED WELL BELOW FREEZING--HIGHLY UNUSUAL ANY TIME OF YEAR...MUCH LESS THE MIDDLE OF NOVEMBER. SURPRISINGLY...THE BOUNDARY LAYER HAS SHOWN SIGNS OF RECOUPLING OFF AND ON OVER THE PAST FEW HOURS...WHICH IS A BIT UNUSUAL GIVEN THE STRENGTH OF THE NOCTURNAL INVERSION NOTED ON VARIOUS RAP FORECAST SOUNDINGS. THERE MUST BE JUST ENOUGH TURBULENT MIXING INDUCED BY 15-20 KT OF WIND ATOP THE BOUNDARY LAYER TO INDUCE TRANSIENT POCKETS OF RECOUPLING...WHICH IS NEARLY IMPOSSIBLE TO FORECAST. THIS HAS HAD SOMEWHAT OF A NEGATIVE IMPACT ON THERMAL DECLINES SINCE LATE TUESDAY EVENING...BUT SHOULD REVERSE ITSELF CLOSER TO SUNRISE AS THE CENTER OF ARCTIC ANTICYCLONE DRAWS CLOSER. ANY RELAXATION OF THE WIND WILL ALLOW FOR RAPID TEMPERATURE FALLS GIVEN THE LOW DEWPOINTS THAT ARE IN PLACE. WILL MAINTAIN LOWS IN THE UPPER TEENS/LOWER 20S INLAND WITH UPPER 20/NEAR 30 AT THE BEACHES. THE RECORD LOW FOR THE CHARLESTON AIRPORT HAS ALREADY FALLEN AND THE SAVANNAH AIRPORT AND DOWNTOWN CHARLESTON WILL LIKELY FOLLOW SOON. NOTE...PRELIMINARY DATA SUGGEST THAT WE SHOULD BE ABLE TO CANCEL THE FROST/FREEZE PROGRAM A FEW WEEKS EARLY SINCE A MULTI-HOUR FREEZE WILL LIKELY MAKE IT ALL THE WAY TO THE BEACHES. THIS DECISION WILL BE MADE BY THE INCOMING DAY SHIFT AFTER FINAL LOW TEMPERATURES ARE RECEIVED AND EVALUATED LATER THIS MORNING. A PUBLIC INFORMATION STATEMENT WILL BE ISSUED IF THE DECISION TO END THE FROST/FREEZE PROGRAM EARLY IS MADE. TODAY...WEAK SHORTWAVE ENERGY ROUNDING THE BASE OF THE MEAN LONG- WAVE TROUGH WILL PASS NORTH OF THE AREA TODAY AS A MUCH STRONGER SHORTWAVE DIGS INTO THE WESTERN GREAT LAKES REGION. A LARGE BATCH OF HIGH CLOUDS MOVING ACROSS THE MID-MISSISSIPPI VALLEY EARLY THIS MORNING IS ASSOCIATED WITH THE LEFT EXIT REGION OF A 120 KT 250 HPA JET STREAK...WHICH STRETCHES NORTHWEST-SOUTHEAST ACROSS THE CENTRAL PORTIONS OF THE COUNTRY. THESE CLOUDS ARE FORECAST TO REMAIN WELL TO THE NORTH...SO SUNNY SKIES SHOULD PREVAIL THROUGH THE DAY. DESPITE WEAK WARM AIR ADVECTION...FULL INSOLATION AND INCREASING LOW-LEVEL THICKNESSES...HIGHS MAY ACTUALLY END UP NEAR OR MAYBE EVEN A DEGREE OR TWO COOLER THAN WHAT WAS OBSERVED TUESDAY. THIS DUE IN PART TO A MUCH COLDER START TO THE DAY COMBINED WITH A FAIRLY LOW MID-NOVEMBER SUN ANGLE. EXPECT HIGHS TO RANGE FROM AROUND 50 ACROSS THE FAR NORTH AND NORTHWEST TIER TO THE LOWER 50S ELSEWHERE. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... TONIGHT...THE CENTER OF THE ARCTIC HIGH WILL BE LOCATED JUST TO THE SOUTHWEST TONIGHT...MUCH CLOSER THAN THIS MORNING. CLEAR SKIES AND CALM WINDS WILL ALLOW FOR RAPID TEMPERATURE FALLS AFTER SUNSET WITH ANOTHER HARD FREEZE LIKELY FOR MANY AREAS. LOWS WILL RANGE FROM THE MID-UPPER 20S INLAND TO THE UPPER 20S-LOWER 30S AT THE COAST WITH LOWER-MID 30S ALONG THE BEACHES. SOME GUIDANCE SHOW PACKAGES SHOW TEMPERATURES BOTTOMING OUT IN THE LOWER 20S IN SOME OF THE NORMALLY COLDER STATIONS WELL INLAND...SO FURTHER TEMPERATURE REDUCTIONS MAY BE NEEDED IN LATER FORECASTS. THURSDAY THROUGH SATURDAY...DRY AND COOLER CONDITIONS WILL PERSIST THROUGH LATE WEEK WHILE SFC HIGH PRESSURE REMAINS CENTERED OVER THE SOUTHEASTERN UNITED STATES ON THURSDAY BEFORE GRADUALLY BECOMING CENTERED OVER THE MID ATLANTIC STATES WITH HIGH PRESSURE WEDGING SOUTHWARD INTO THE AREA FRIDAY INTO EARLY SATURDAY. DESPITE A NORTH/NORTHEAST FLOW DEVELOPING AS THIS TRANSITION OCCURS...TEMPS ARE EXPECTED TO MODIFY EACH DAY WITH MOSTLY SUNNY SKIES IN PLACE AND A ZONAL FLOW ALOFT. TEMPS WILL GRADUALLY WARM INTO THE LOWER 60S THURSDAY...THEN INTO THE LOW/MID 60S FRIDAY AND SATURDAY. THURSDAY AND FRIDAY NIGHT LOWS WILL GENERALLY RANGE IN THE MID 30S INLAND TO UPPER 30S/LOWER 40S CLOSER TO THE COAST. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... HIGH PRESSURE WILL SHIFT OFF THE EASTERN SEABOARD SATURDAY NIGHT WHILE A WARM FRONT LIFTS NORTH THROUGH THE SOUTHEASTERN UNITED STATES ON SUNDAY. DEEP LAYERED MOISTURE CHARACTERIZED BY PWATS NEAR 2.0 INCHES ALONG WITH STRONG ISENTROPIC ASCENT SHOULD BRING A PERIOD OF ENHANCED RAINFALL ON SUNDAY...ESPECIALLY NEAR THE WARM FRONT. HAVE THEREFORE INCREASED POPS UP TO 60-70 PERCENT OVER MOST AREAS. CLOUD COVER WILL ALSO BE WIDESPREAD TO START OFF THE WEEK...BUT WARM AIR ADVECTION AHEAD OF AN APPROACHING COLD FRONT SUPPORTS OVERALL HIGH TEMPS IN THE LOW 70S ON SUNDAY...THEN MID/UPPER 70S ON MONDAY. THUNDERSTORMS WILL REMAIN IN THE FORECAST AHEAD OF THE COLD FRONT MONDAY...WITH FROPA EXPECTED TO OCCUR SOMETIME MONDAY NIGHT INTO EARLY TUESDAY. DRY AND COOLER HIGH PRESSURE IS THEN EXPECTED TO RETURN OVER THE AREA INTO THE MIDDLE OF NEXT WEEK WHILE THE AXIS OF A MID LVL TROUGH OF LOW PRESSURE SHIFTS OVER THE AREA. IN GENERAL...AFTERNOON HIGHS SHOULD RANGE IN THE MID 60S ON TUESDAY...FOLLOWED BY UPPER 50S ON WEDNESDAY. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... VFR. EXTENDED AVIATION OUTLOOK...MVFR VSBYS/CIGS CHANCES WILL INCREASE SATURDAY NIGHT INTO SUNDAY AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. FLIGHT RESTRICTIONS APPEAR LIKELY INTO MUCH OF MONDAY BEFORE A COLD FRONT SHIFTS OVER THE AREA MONDAY NIGHT. && .MARINE... TODAY...GUSTY NORTH TO NORTHWEST WINDS CONTINUE TO PLAGUE THE WATERS THIS MORNING. WINDS AND SEAS WILL DIMINISH LATER TODAY AS ARCTIC HIGH PRESSURE BUILDS EAST. WINDS MAY ACTUALLY GO VARIABLE BY AFTERNOON WITH THE SURFACE RIDGE FORECAST TO ALIGN ITSELF RIGHT ALONG THE BEACHES. TONIGHT...NORTHWEST WINDS WILL INCREASE TONIGHT AS THE SURFACE RIDGE BREAKS DOWN AND THE CENTER OF THE ARCTIC HIGH SETTLES IN TO THE SOUTHWEST OF THE FORECAST AREA. WINDS AND SEAS WILL GENERALLY REMAIN 15 KT OR LESS WITH SEAS 1-3 FT. THURSDAY THROUGH SATURDAY MORNING...WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS AS HIGH PRESSURE SETTLES OVER THE WATERS WELL AHEAD OF DEVELOPING LOW PRESSURE INLAND. HOWEVER...WINDS/SEAS WILL INCREASE/BUILD OVER THE PERIOD AS HIGH PRESSURE BEGINS TO SLIDE OFF THE EASTERN SEABOARD WHILE A WARM FRONT BEGINS TO LIFT NORTH TOWARDS THE AREA. SATURDAY AFTERNOON THROUGH MONDAY...WINDS/SEAS SHOULD APPROACH SMALL CRAFT ADVISORY LEVELS BY LATE WEEKEND AS AN ENHANCED PRESSURE GRADIENT DEVELOPS BETWEEN HIGH PRESSURE SLIDING OFF THE ATLANTIC COAST AND A WARM FRONT LIFTING OVER THE WATERS. ELEVATED WINDS/SEAS WILL LIKELY PERSIST THROUGH MUCH OF MONDAY UNTIL A COLD FRONT SHIFTS OFFSHORE MONDAY NIGHT. IN GENERAL...SOUTHERLY WINDS SHOULD PEAK NEAR 25 KTS OVER ALL WATERS SUNDAY AND SUNDAY NIGHT...WHILE SEAS BUILD TO 6-9 FT...HIGHEST BEYOND 15 NM FROM THE COAST. && .CLIMATE... THE RECORD LOW FOR THE CHARLESTON AIRPORT HAS ALREADY FALLEN AND THE SAVANNAH AIRPORT AND DOWNTOWN CHARLESTON WILL LIKELY FOLLOW SOON. RECORD LOWS FOR NOVEMBER 19TH... KCHS...27 SET IN 1949 /ALREADY BROKEN/... KCXM...31 SET IN 1903. KSAV...27 SET IN 2008 AND PREVIOUS. RECORD LOWS FOR NOVEMBER 20TH... KCHS...25 SET IN 1951. KCXM...28 SET IN 1951. KSAV...24 SET IN 1914. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WARNING UNTIL 10 AM EST THIS MORNING FOR GAZ087-088- 099>101-114>119-137>141. SC...FREEZE WARNING UNTIL 10 AM EST THIS MORNING FOR SCZ040-042>045- 047>052. MARINE...NONE. && $$ ST/DPB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
335 AM CST WED NOV 19 2014 .SHORT TERM... 335 AM CST TODAY THROUGH FRIDAY... MAIN FOCUS IN NEAR TERM IS WITH CLIPPER-TYPE SYSTEM MOVING THROUGH THE REGION THIS MORNING...AND THE POTENTIAL FOR SOME LIGHT ACCUMULATING SNOW MAINLY ACROSS FAR NORTHERN/NORTHEAST IL. OTHER HIGHLIGHTS...OR LOW LIGHTS AS THE CASE MAY BE...THROUGH FRIDAY ARE CONTINUED SUB-NORMAL CHILLY TEMPERATURES AND THE POTENTIAL FOR SOME LIGHT FREEZING RAIN FRIDAY NIGHT INTO EARLY SATURDAY MORNING AHEAD OF A SYSTEM WHICH WILL BRING RAIN AND WARMER WEATHER OVER THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY DEPICTS A SHORT-WAVE DIGGING SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY AND APPROACHING WI/IL AT 0830Z. SURFACE TROUGH REFLECTION WAS OVER SOUTHERN MN/EAST CENTRAL IA...WITH FAIRLY IMPRESSIVE SURFACE PRESSURE FALLS SPREADING INTO SOUTHERN WI/IL AND BACKING WINDS TO THE SOUTH AND RAISING TEMPS. RADAR RETURNS FROM MID-LEVEL CLOUDS HAVE DEVELOPED SOUTHEAST FROM TWIN CITIES AREA...THOUGH DRY LOW LEVEL AIR SO FAR HAS SLOWED DEVELOPMENT OF SNOW AT THE SURFACE. TRACK OF SYSTEM...RADAR TRENDS AND HIGH-RES HRRR GUIDANCE ALL INDICATE BEST POTENTIAL FOR MEASURABLE SNOW THROUGH THE EARLY MORNING HOURS WILL BE ALONG A ROUGHLY MSP-MKE CORRIDOR...WITH GENERALLY LIGHT AMOUNTS OF AN INCH OR LESS EXPECTED ACROSS FAR NORTHEAST IL AND PARTS OF NORTHERN IN. FORECAST SOUNDINGS INDICATE DRY AIR ARRIVING IN MID-LEVELS BY MID-LATE MORNING AND LIMITING BEST FORCING FOR SNOW TO A ONLY A FEW HOURS THIS AM. SURFACE TROUGH PASSES MID-DAY...WITH RENEWED COLD ADVECTION AND EXTENSIVE UPSTREAM CLOUDINESS SUPPORTING SCATTERED FLURRIES THIS AFTERNOON AS LOW-LEVEL THERMAL PROFILES COOL AGAIN. MOISTURE BECOMES VERY SHALLOW TONIGHT AND THURSDAY...DECREASING POTENTIAL FOR FLURRIES DESPITE ANOTHER DIGGING SHORT WAVE ACROSS THE WESTERN LAKES. THE MAIN LARGE-SCALE UPPER TROUGH AXIS THEN SHIFTS EAST THURSDAY NIGHT...ALLOWING SURFACE HIGH PRESSURE TO SPREAD EAST ACROSS THE AREA BY FRIDAY MORNING. TEMPERATURES WERE RISING INTO THE 20S WITH THE SOUTH WINDS THIS MORNING...WITH HIGHS EXPECTED TO TOP OUT IN THE MID 20S TO LOW 30S TODAY WITH THE MILDEST TEMPS ACROSS THE FAR EAST/SOUTHEAST CWA. COLDER TEMPS AGAIN TONIGHT AND THURSDAY...WITH THE COLDEST EXPECTED EARLY FRIDAY MORNING IN THE VICINITY OF THE SURFACE RIDGE AXIS. LOWS IN THE SINGLE DIGITS TO LOWER TEENS ARE LIKELY FRIDAY MORNING WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. MUCH-TOUTED CHANGE IN THE UPPER PATTERN WILL BE UNDERWAY FRIDAY... AS FLOW DE-AMPLIFIES AND UPPER TROUGH MOVES ACROSS THE SOUTHWESTERN STATES AND ACROSS THE CENTRAL AND SOUTHERN ROCKIES FRIDAY NIGHT. ALONG WITH A DISTURBANCE MOVING ACROSS CENTRAL CANADA...THIS WILL SET UP SOUTHERLY RETURN FLOW INTO THE REGION FRIDAY NIGHT WITH ASSOCIATED WARM/MOIST ADVECTION. MODELS CONTINUE TO INDICATE DEVELOPMENT OF SOME LIGHT PRECIP OVERNIGHT...WITH FORECAST SOUNDINGS INDICATING ELEVATED WARM LAYER TEMPS APPROACHING +5C WHILE SFC TEMPS ARE BELOW FREEZING. THIS SUPPORTS THE POTENTIAL FOR SOME LIGHT FREEZING RAIN OR SLEET FRIDAY NIGHT...BEFORE WARM ADVECTION EVENTUALLY RAISES SURFACE TEMPS ABOVE FREEZING ON SATURDAY. MODELS HAVE TRENDED A LITTLE SLOWER WITH ARRIVAL OF LIGHT PRECIP...THOUGH ALSO SOMEWHAT COLDER INITIALLY AT THE SURFACE. WILL CONTINUE TO MENTION POTENTIAL FOR FREEZING RAIN/SLEET AND WILL HAVE TO MONITOR TRENDS FOR THE POTENTIAL OF SOME LIGHT ICE ACCUMULATION LATER FRIDAY NIGHT INTO EARLY SATURDAY. RATZER && .LONG TERM... 335 AM CST SATURDAY THROUGH TUESDAY... LONGER RANGE MODEL SOLUTIONS CONTINUE TO LIFT SOUTHWESTERN TROUGH TOWARD THE AREA OVER THE WEEKEND...WITH LOW LEVELS QUICKLY WARMING ABOVE FREEZING SATURDAY MORNING AND CHANGING ANY MIXED PRECIP OVER TO RAIN. 00Z GFS/ECMWF HAVE COME INTO BETTER AGREEMENT IN TIMING THE NEGATIVELY-TILTED SOUTHWESTERN SHORT WAVE AND DEEPENING SURFACE LOW TO LIFT ACROSS THE FORECAST AREA SUNDAY AFTERNOON/EVENING...WITH TEMPS RISING INTO THE BALMY 45-50 RANGE. SOME DIFFERENCES REMAIN WITH THE DETAILS OF PHASING THIS SYSTEM WITH A NORTHERN STREAM DEVELOPING CLOSED UPPER LOW OVER THE REGION SUNDAY NIGHT INTO MONDAY...THOUGH REASONABLY SIMILAR IN THE IDEA OF MILD WITH RAIN/SHOWERS EVENTUALLY GIVING WAY TO LIGHTER RAIN/SNOW TRANSITION MONDAY-MONDAY NIGHT AND TO LINGERING SNOW SHOWERS TUESDAY AS WE SHIFT BACK TO A DEEP EASTERN CONUS UPPER TROUGH AND COLDER WEATHER EARLY NEXT WEEK. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * -SN MOVES IN EARLY THIS MORNING WITH MVFR VSBY AT FIRST. VSBY DROPS TO LIFR BY 12Z. * MVFR CIGS ACCOMPANY SNOW..AND MAY SEE CIGS DROP TO IFR. * -SN TAPERS TO FLURRIES BY MID MORNING. * GUSTY WEST WINDS RETURN MID MORNING AND PERSIST THROUGH THE NIGHT. MAX GUSTS IN THE AFTN WILL BE ARND 25 KT. JEE //DISCUSSION...UPDATED 06Z... A TROUGH OF LOW PRESSURE IS APPROACHING FROM THE WEST AND IT WILL BRING SNOW AND LOWER CIGS WITH IT. SW WINDS WILL BECOME SSE FOR A COUPLE OF HOURS EARLY THIS MORNING...BUT THEN QUICKLY RETURN TO SSW. DID NOT MAKE ANY CHANGES TO SNOW IN THE TAF AS IT ALL LOOKS VERY REASONABLE. SNOW MOVES IN EARLY THIS MORNING AND PICKS UP IN INTENSITY ARND 12Z. AT LEAST IFR VSBY IS EXPECTED...AND WILL LIKELY SEE A PERIOD OF LESS THAN ONE MILE VSBY. CIGS WILL ALSO COME DOWN WITH THE SNOW AND HAVE HIGHER CONFIDENCE IN MVFR CIGS VERSUS IFR GIVEN THE UPSTREAM OBSERVATIONS. ACCUMULATING SNOW COMES TO AN END BY MID MORNING BUT FLURRIES PERSIST THROUGH THE AFTERNOON. CIGS SLOWLY RISE AND GUSTY WEST WINDS SET UP WITH MAX GUSTS ARND 25 KT. GUSTS WILL SLOWLY DIMINISH THROUGH THE NIGHT. JEE //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH CONFIDENCE IN WIND FORECAST. * HIGH CONFIDENCE IN SNOW AND LOWER CIGS & VSBY...MEDIUM-HIGH CONFIDENCE IN TIMING. * MEDIUM-HIGH CONFIDENCE IN CIGS REMAINING ABOVE IFR WITH SNOW. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... THURSDAY...VFR. FRIDAY...CHANCE OF A WINTRY MIX OVERNIGHT. IFR LIKELY OVERNIGHT. SATURDAY...CHANCE OF A WINTRY MIX EARLY THEN BECOMING RAIN. IFR LIKELY. SUNDAY....RAIN. IFR LIKELY. MONDAY...CHANCE OF RAIN OR SNOW. MVFR TO IFR CIGS. RODRIGUEZ && .MARINE... 210 AM CST HEADLINES...DID NOT MAKE ANY CHANGES TO THE SMALL CRAFT ADVISORY BUT DID UPGRADE THE OPEN WATER GALE WATCH TO A WARNING. MAY SEE WINDS DIMINISH TO BELOW GALES FASTER THAN THE WARNING WOULD INDICATE...BUT HAVE LIMITED CONFIDENCE IN HOW LONG GALES WILL LAST SO LEFT THE END TIME AS IS. A TROUGH OF LOW PRESSURE MOVES OVER THE LAKE THIS AFTERNOON WITH WEST WINDS BECOMING SOUTH OVER THE NEXT FEW HOURS. WINDS RETURN TO WEST BEHIND THE TROUGH THIS AFTERNOON AND INCREASE TO GALES BY THE LATE AFTERNOON. GALES CONTINUE OVERNIGHT INTO THURSDAY MORNING...BUT THEY MAY COME DOWN BELOW GALE FORCE SOONER THAN THE WARNING INDICATES. NW WINDS TO 30 KT BECOME WEST 10-20 KT BY FRIDAY MORNING. HIGH PRESSURE PASSES SOUTH OF THE LAKE LATE THURSDAY NIGHT AND FRIDAY MORNING WITH LIGHT WINDS BECOMING SOUTH TO SOUTHWEST TO 20 KT BY FRIDAY EVENING. WINDS INCREASE TO 30 KT FRIDAY NIGHT AS THE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A LOW OVER NORTHERN QUEBEC. SOUTH WINDS PERSIST THROUGH SATURDAY NIGHT BEFORE BECOMING SOUTHEAST SUNDAY AHEAD OF THE NEXT LOW. GUIDANCE DIFFERS ON STRONG THE LOW WILL BE AND ITS EXACT PATH BUT GUIDANCE MEMBERS DO AGREE THAT THE LAKE WILL MOVE OVER THE LAKE AT SOME POINT SUNDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM WEDNESDAY TO 9 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
219 AM MST WED NOV 19 2014 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 218 AM MST WED NOV 19 2014 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS INDICATE LARGE SCALE TROUGHING ACROSS THE EASTERN UNITED STATES WITH AN AMPLIFIED RIDGE UPSTREAM ACROSS THE PACIFIC US COAST. BETWEEN THESE FEATURES NORTH-NORTHWEST FLOW IS IN PLACE FROM THE NORTHERN PLAINS TO SOUTHERN PLAINS. AT THE THE SURFACE ARCTIC COLD FRONT IS APPROXIMATELY ALONG THE SD/NE STATE LINE WITH A SURFACE LOW OVER NORTHCENTRAL COLORADO. SURFACE HIGH PRESSURE IS CURRENTLY IN PLACE OVER OUR CWA. UPPER LEVEL STORM TRACK IS SPLIT AROUND OUR CWA THROUGH THE END OF THE WEEK SO FORECAST CONDITIONS SHOULD REMAIN DRY DURING THESE PERIODS. AS OF 00Z GUIDANCE...NAM SNOW DEPTH CONTINUED TO BE UNREFLECTIVE OF CURRENT SNOW FIELD AND HOLDS THIS SNOW FIELD IN PLACE THROUGH THIS WEEKEND. AS A RESULT BL CONDITIONS AND SURFACE TEMPS FROM THE NAM WERE NOT USED IN CURRENT FORECAST...THOUGH LARGER SCALE FIELDS WERE TAKEN INTO CONSIDERATION. RAP/HRRR SNOW FIELDS WERE MORE REFLECTIVE OF REALITY...SO THESE MODELS WERE USED THROUGH THE NEXT 24 HR FOR ADJUSTING SHORT RANGE BL TRENDS. TODAY-TONIGHT...ARCTIC FRONT MOVES FROM NORTHERN PLAINS TOWARDS CENTRAL MISSISSIPPI RIVER VALLEY BY MIDDAY TODAY. WHILE COLDEST AIR MASS REMAINS NORTH AND EAST...THIS FRONT WILL LEAD TO A DECREASE IN TEMPS ALOFT OVER OUR CWA. LEE TROUGH REDEVELOPING THIS AFTERNOON WILL HELP BRING RETURN FLOW INTO MOST OF OUR CWA...SO WE SHOULD MANAGE TO WARM TO SEASONAL NORMALS IN THE UPPER 40S TO AROUND 50 FOR MOST LOCATIONS. THURSDAY-FRIDAY NIGHT...SHORTWAVE RIDGE QUICKLY SHIFTS EAST WITH SHORTWAVE TROUGHS SPLITTING AROUND OUR CWA DURING THESE PERIODS. AS THIS PATTERN EVOLVES TEMPS ALOFT WILL GENERALLY SUPPORT SEASONAL HIGHS IN THE UPPER 40S/LOWER 50S. AS THE SOUTHERN STREAM UPPER LOW AND SURFACE LOW TRANSITION ACROSS THE SOUTHERN PLAINS...EASTERLY TO SOUTHEAST FLOW WILL BRING INCREASING LOW LEVEL MOISTURE ACROSS WESTERN KS/SW NEBRASKA. GFS/SREF ARE SHOWING A SHALLOW SATURATED LAYER DEVELOPING THURSDAY NIGHT. THERE IS WEAK LIFT WITHIN THIS LAYER...HOWEVER DUE TO THE LIMITED DEPTH OF THIS LAYER CONFIDENCE IS HIGHER IN A FREEZING FOG/STRATUS EVENT RATHER THAN FREEZING DRIZZLE THURSDAY NIGHT/FRIDAY MORNING. I COULDNT RULE OUT A FEW POCKETS OF FREEZING DRIZZLE THOUGH. AS LEE TROUGH REDEVELOPS FRIDAY...DRY AIR ADVECTING IN FROM THE WEST SHOULD HELP ERODE ANY FOG/STRATUS. I AM CONCERNED THAT STRATUS MAY HOLD ON IN OUR EAST AND LIMIT DIURNAL WARMING...BUT AT THIS POINT I DONT HAVE ENOUGH CONFIDENCE TO UNDERCUT CONSENSUS IN OUR EAST BY MORE THAN A FEW DEGREES. GFS STILL SHOWS LOW LEVEL MOISTURE POOLING ACROSS OUR EAST FRIDAY NIGHT IN OUR FAR EASTERN CWA...SO FREEZING FOG MAY REDEVELOP. ANY FOG SHOULD BE QUICKLY TRENDING EAST WITH WEST/SOUTHWEST FLOW MOVING EAST THROUGH FRIDAY NIGHT. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 218 AM MST WED NOV 19 2014 SATURDAY...LOTS OF SUN DURING TIME OF PEAK HEATING BUT AN INCREASE IN MID AND HIGH CLOUDS MOVES INTO FAR EASTERN COLORADO TOWARD THE END OF THE DAY. THESE CLOUDS THEN TRAVERSE THE REST OF THE FORECAST AREA SATURDAY NIGHT. THERE IS SOME WEAK MID LEVEL FORCING WITH THE MOSTLY MID LEVEL CLOUDINESS WHICH COULD PRODUCE A FEW AREAS OF VIRGA BUT WITH RATHER LIMITED MOISTURE IN THE LOWER ATMOSPHERE PRECIPITATION CHANCES ARE PRETTY LOW. SOMETHING TO WATCH. BEHIND THE WAVE THAT MOVES THROUGH SATURDAY NIGHT WILL BE A COLD FRONT AND NORTHWEST WINDS INCREASING INTO THE 15 TO 20 MPH RANGE WITH SOME HIGHER GUSTS FOR MOST OF THE AREA. GFS/ECMWF 850MB TEMPERATURES SUPPORT HIGH TEMPERATURES PRODUCED BY MEX GUIDANCE (UPPER 50S AND LOW 60S) VS THE EXTENDED PROCEDURE WHICH IS PRODUCING LOW TO MID 50S. PER COORDINATION WITH NORTHERN AND EASTERN AND SOUTHERN OFFICES HAVE RAISED TEMPS ABOUT 3-4F AS A START. LOWS IN THE MID 20S TO AROUND 30. SUNDAY...UPPER TROUGH AXIS AND PLENTIFUL CLOUDINESS PASS ACROSS THE AREA DURING THE DAY LEAVING THE AREA UNDER NORTHWEST FLOW AND DECREASING CLOUDINESS OVERNIGHT. IT WILL BE WINDY DURING THE DAY WITH NORTHWEST WINDS AROUND 20 MPH WITH HIGHER GUSTS. DURING THE NIGHT 10 TO 20 MPH. GFS/ECMWF 850MB TEMPERATURES SUPPORT ADVERTISED HIGHS IN THE LOW TO MID 40S IN FAR EASTERN COLORADO...UPPER 40S TO LOW 50S EAST OF THE STATE LINE. LOWS SUNDAY NIGHT IN THE UPPER TEENS IN FAR EASTERN COLORADO TO THE MID 20S IN THE HILL CITY AREA. DESPITE INCREASING MOISTURE IN THE MID AND UPPER LEVELS FINER DETAILS AS TO WHERE IT WILL BE AND TIMING OF THE TROUGH PASSAGE PRECLUDE A PRECIPITATION MENTION AT PRESENT TIME. MONDAY...GFS/ECMWF HAVING A HARDER TIME AGREEING ON LARGE SCALE FEATURES AND POSSIBLY MORE IMPORTANTLY LOWER LEVEL FEATURES. ONE EXAMPLE IS 850MB TEMPERATURES. GFS ABOUT 6-7C WARMER THAN THE ECMWF WHICH MAKES A LARGE DIFFERENCE IN TEMPERATURE FORECAST. NO CHANGES MADE AT THIS POINT AND RAN WITH MID 30S TO LOW 40S IN FAR EASTERN COLORADO WITH LOW 40S EAST OF THE BORDER. VARIABLE CLOUDINESS THROUGH THE PERIOD WITH DRY CONDITIONS EXPECTED. LOWS MONDAY NIGHT TEENS TO LOW 20S. CURRENTLY LOOKING AT WINDY CONDITIONS FROM THE NORTHWEST DURING THE DAY. TUESDAY...MAY SEE MORE CLOUDINESS THEN CURRENTLY ADVERTISED AND ONCE AGAIN ITS CONFINED TO MID AND UPPER LEVELS WHICH ISNT FAVORABLE FOR PRECIPITATION. NO CHANGES TO TEMPERATURE FORECAST WITH HIGHS IN THE LOW TO MID 40S AND LOWS IN THE MID 20S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1019 PM MST TUE NOV 18 2014 VFR CONDITIONS EXPECTED FOR THE 6Z TAFS. LIGHT NORTHWEST WINDS WILL CONTINUE UNTIL LATE AFTERNOON THEN TURN TO THE SOUTHWEST AS A SURFACE TROUGH MOVES ACROSS THE AREA FROM THE WEST BEHIND THE EXITING SURFACE RIDGE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...JTL
AREA FORECAST DISCUSSION
NWS JACKSON KY
410 AM EST WED NOV 19 2014 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 345 AM EST WED NOV 19 2014 07Z SFC ANALYSIS SHOWS HIGH PRESSURE OVER EASTERN KENTUCKY. THE CLEAR SKIES IN PLACE...LIGHT WINDS...AND LOW DEWPOINTS ARE MAKING A RECORD SETTING COLD NIGHT EVEN COLDER FOR THE VALLEYS THROUGH THE AREA DUE TO AN INVERSION AND RADIATIONAL COOLING. CURRENTLY READINGS ARE VARYING FROM NEAR 10 DEGREES IN THE DEEPER VALLEYS TO THE MID AND UPPER TEENS ON THE RIDGES. DEWPOINTS...MEANWHILE...ARE RUNNING IN THE SINGLE DIGITS. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT A DEEP TROUGH GENERALLY ON THE WANE OVER THE OHIO VALLEY BUT WITH A SLIGHT RESURGENCE TAKING PLACE INTO THURSDAY MORNING DUE TO A SHARP SHORTWAVE CROSSING THE GREAT LAKES. THIS PROCESS LURES A WEAK ENERGY STREAM NORTH INTO KENTUCKY DURING THE DAY THURSDAY AS THE LARGER TROUGH STARTS TO MOVE OFF TO THE NORTHEAST. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR MODELS FOR THE WX DETAILS. SENSIBLE WEATHER WILL FEATURE A VERY COLD START TO THE DAY WITH READINGS SOME 5 DEGREES OR SO BELOW RECORD LEVELS IN MANY PLACES ACROSS EAST KENTUCKY. WITH AMPLE SUNSHINE IN THE MORNING... TEMPERATURES WILL CLIMB SMARTLY SO THAT HIGHS WILL BE AT LEAST 10 DEGREES WARMER THAN YESTERDAY THROUGHOUT THE AREA. HOWEVER...HIGH... AND LATER LOWER CLOUDS...WILL BE ON THE INCREASE DURING THE AFTERNOON FROM THE NORTHWEST AHEAD OF AN APPROACHING CLIPPER SYSTEM AND ITS TRAILING COLD FRONT. THIS FRONT WILL PRESS INTO THE AREA WITH A POCKET OF LOW LEVEL MOISTURE CAPABLE OF GENERATING LIGHT PCPN WHEN COMBINED WITH THE SMALL LIFT ACCOMPANYING THE FRONT. THE QUESTION BECOMES P-TYPE GIVEN THE COLD TEMPERATURES ALOFT AND DEPTH OF...OR LACK THEREOF...MOISTURE. IT DOES LOOK LIKE THERE WILL BE JUST ENOUGH MOISTURE AT THE COLDER TEMPERATURES TO GENERATE ICE CRYSTALS FOR SNOW AND SO THAT WAS THE MAIN WX FORECAST FOR TONIGHT. HOWEVER...SHOULD THIS NOT OCCUR...POCKETS OF FREEZING DRIZZLE WILL BE POSSIBLE. NEVERTHELESS...ONLY A HUNDREDTH OR TWO OF LIQUID EQUIVALENT IS EXPECTED FROM THIS FRONT SO IT IS A MARGINAL CONCERN...BUT ONE WORTH NOTING. LOW CLOUDS WILL THEN LINGER OVER THE AREA THROUGH THE REST OF THE DAY THURSDAY WITH LITTLE PUSH TO CLEAR THEM OUT...HINDERING OUR TEMPERATURE RECOVERY. USED THE BCCONSSHORT GUIDANCE FOR THE STARTING POINT OF THE T/TD AND WIND GRIDS THROUGH THE FIRST PART OF TONIGHT AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS FOR THE TERRAIN DIFFERENCES THROUGHOUT THE PERIOD. AS FOR POPS...ENDED UP HIGHER THAN ALL THE GUIDANCE TONIGHT...IN THE SCATTERED RANGE OF THE WX COVERAGE TERM. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 409 AM EST WED NOV 19 2014 A STRONG UPPER LEVEL TROUGH ACROSS MUCH OF THE NE CONUS WILL CONTINUE TO SHIFT EASTWARD AS WE HEAD INTO THURSDAY NIGHT. AS A RESULT...MUCH OF THE OHIO RIVER VALLEY REGION CAN EXPECT INCREASING HEIGHTS AND SURFACE HIGH PRESSURE TO BE MOVING IN. WITH BOTH DRY AIR IN THE MID AND UPPER LEVELS...THIS WILL PRODUCE STRONG RADIATIONAL COOLING AND ALLOW TEMPERATURES TO DROP BACK DOWN INTO THE UPPER TEENS AND LOW 20S ONCE MORE. LUCKILY...WINDS NEAR THE SURFACE WILL BE FAIRLY LIGHT...SO DON/T EXPECT THE WIND CHILL FACTOR TO BE MORE THAN A FEW DEGREES COOLER. WHAT IS OF CONCERN...HOWEVER...IS THE LOW LEVEL MOISTURE THAT COULD BE LINGERING FROM THE PREVIOUS DAY. ACCORDING TO THE LATEST FORECAST SOUNDINGS...A STRONG SUBSIDENCE INVERSION SETS UP THURSDAY NIGHT...TRAPPING A LAYER OF LOW LEVEL MOISTURE NEAR THE SURFACE. GIVEN THE EXPECTED TEMPERATURES...IF ANY FOG DEVELOPS FROM THIS...COULD BE LOOKING AT A FREEZING FOG EVENT. HIGH PRESSURE SHOULD HOLD ON THROUGH FRIDAY NIGHT...WITH HEIGHTS ALOFT CONTINUING TO INCREASE. THIS WILL ALLOW TEMPS TO RISE INTO THE UPPER 30S AND LOW 40S ON FRIDAY AFTERNOON...AND THEN INTO THE 50S AS WE HIT SATURDAY AFTERNOON. THERE WILL BE A DISTURBANCE WHICH IS POSED TO MOVE INTO THE AREA DURING THE WEEKEND. AS A RESULT...EXPECT CLOUD COVER TO SPREAD ACROSS EASTERN KY AHEAD OF THE SYSTEM THROUGHOUT FRIDAY NIGHT. THE LOW LEVELS LOOK TO BE QUITE DRY...WITH A WARM NOSE ABOVE FREEZING JUST ABOVE THE SURFACE. AS A RESULT...DO NOT EXPECT ANY FURTHER CONCERNS FOR FOG OR FREEZING PRECIP DURING THIS TIME PERIOD...BUT IF ANY PRECIP DOES MAKE IT INTO OUR WESTERN FRINGE COUNTIES BY 12Z SATURDAY...COULD SEE SOME SLIGHT CHANCES FOR FREEZING RAIN. DAYS 4 THROUGH 7... MODELS ARE IN FAIRLY GOOD AGREEMENT WITH UL PATTERN THROUGH THIS PERIOD. UL RIDGING GRADUALLY SHIFTS EWRD OVER THE ATLANTIC AS A BROAD UL TROF MOVES OVER THE EASTERN CONUS ON MONDAY. THE UL TROF WILL BE THE DOMINATE WX PATTERN FROM MONDAY THROUGH THE END OF THE PERIOD. AT LOWER LEVELS... LL MOISTURE INCREASES SATURDAY AHEAD OF THE NEXT SYSTEM THAT WILL EJECT OUT OF THE SOUTHERN PLAINS. THIS SYSTEM IS FORECASTED TO QUICKLY MOVE NEWD ACROSS THE CWA SUNDAY AFTERNOON. SINCE IT IS QUICK MOVING...THE MAIN BATCH OF PRECIP IS FORECASTED TO AFFECT THE AREA SUNDAY AFTERNOON AND EVENING. IN TERMS OF THE GRIDS...HAVE SLOWED DOWN THE ONSET OF THE PRECIP FROM PREVIOUS FORECAST SINCE THE GFS/ECMWF KEPT PRECIP OUT OF THE CWA UNTIL 12Z SUNDAY. AS THE SYSTEM LIFTS NEWD...THERE MAY BE SOME ADDITIONAL PRECIP ASSOCIATED WITH THE SFC LOW...AND ADDITIONAL S/WV ENERGY MOVING THROUGH THE BASE OF THE TROF. DEPENDING ON THE LOWS TRACK AND HOW IT PHASES WITH THE NORTHERN STREAM ENERGY...CLOUDS AND A CHANCE FOR PRECIP COULD LINGER THROUGH TUESDAY MORNING. BOTH THE GFS AND ECMWF DIFFER IN REGARDS TO THE PHASING OF THE NORTHERN AND SOUTHERN STREAM ENERGY...SO HAVE KEPT CHANCES FOR RAIN IN THE GRIDS THROUGH MONDAY EVENING. TUESDAY AND WEDNESDAY APPEAR TO BE MOSTLY QUIET AS THE SFC TROF SLOWLY MOVES OUT AND HIGH PRESSURE BUILDS INTO THE REGION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 130 AM EST WED NOV 19 2014 THE TAF SITES WILL EXPERIENCE VFR CONDITIONS FOR THE BULK OF THE TAF PERIOD. HOWEVER CLOUD COVER WILL DEVELOP AND THICKEN BY WEDNESDAY EVENING FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA AS A CLIPPER SYSTEM EJECTS OUT OF THE NORTHERN PLAINS AND ACROSS THE LOWER GREAT LAKES REGION. AFTER 00Z A FEW SNOW SHOWERS WILL BE POSSIBLE FROM THIS SYSTEM AND A VCSH WAS ADDED TO THE TAFS. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE REST OF THE NIGHT. THEY ARE THEN EXPECTED TO BE GUSTY TOMORROW FROM THE SOUTH TO SOUTHWEST WITH INCREASING INTENSITY AFTER 15Z TO AROUND 10 KTS SUSTAINED...GUSTING TO AROUND 20 KTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...JMW/JVM AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
345 AM EST WED NOV 19 2014 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 345 AM EST WED NOV 19 2014 07Z SFC ANALYSIS SHOWS HIGH PRESSURE OVER EASTERN KENTUCKY MAKING FOR A VERY COLD NIGHT. THE CLEAR SKIES IN PLACE...LIGHT WINDS...AND LOW DEWPOINTS ARE MAKING A RECORD SETTING COLD NIGHT EVEN COLDER FOR THE VALLEYS THROUGH THE AREA DUE TO AN INVERSION AND RADIATIONAL COOLING. CURRENTLY READINGS ARE VARYING FROM NEAR 1O DEGREES IN THE DEEPER VALLEYS TO THE MID AND UPPER TEENS ON THE RIDGES. DEWPOINTS... MEANWHILE...ARE RUNNING IN THE SINGLE DIGITS. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT A DEEP TROUGH IN GENERAL ON THE WAN OVER THE OHIO VALLEY BUT WITH A SLIGHT RESURGENCE TAKING PLACE INTO THURSDAY MORNING DUE TO A SHORTWAVE CROSSING THE GREAT LAKES. THIS PROCESS LURES A WEAK ENERGY STREAM NORTH INTO KENTUCKY DURING THE DAY THURSDAY AS THE LARGER TROUGH STARTS TO MOVE OFF TO THE NORTHEAST. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR FOR THE DETAILS. SENSIBLE WEATHER WILL FEATURE A VERY COLD START TO THE DAY WITH READINGS SOME 5 DEGREES OR SO BELOW RECORD LEVELS. WITH AMPLE SUNSHINE IN THE MORNING TEMPERATURES WILL CLIMB SMARTLY SO THAT HIGH WILL BE AT LEAST 10 DEGREES WARMER THAN YESTERDAY THROUGHOUT THE AREA. HOWEVER...HIGH...AND LATER LOWER CLOUDS...WILL BE ON THE INCREASE DURING THE AFTERNOON FROM THE NORTHWEST AHEAD OF AN APPROACHING CLIPPER SYSTEM AND ITS TRAILING COLD FRONT. THIS FRONT WILL PRESS INTO THE AREA WITH A POCKET OF LOW LEVEL MOISTURE CAPABLE OF GENERATING PCPN FROM THE SMALL LIFT PRESENT WITH THE FRONT. THE QUESTION BECOMES P-TYPE GIVEN THE COLD TEMPERATURES ALOFT AND DEPTH OF...OR LACK THEREOF...MOISTURE. IT DOES LOOK LIKE THERE WILL BE JUST ENOUGH MOISTURE AT THE COLDER TEMPERATURES TO GENERATE ICE CRYSTALS FOR SNOW AND SO THAT WAS THE MAIN WX FORECAST FOR TONIGHT. HOWEVER...SHOULD THIS NOT OCCUR...POCKETS OF FREEZING DRIZZLE WILL BE POSSIBLE. NEVERTHELESS...ONLY A HUNDREDTH OR TWO OF LIQUID EQUIVALENT IS EXPECTED FROM THIS FRONT SO IT IS A MARGINAL CONCERN...BUT ONE WORTH NOTING. LOW CLOUDS WILL THEN LINGER OVER THE AREA THROUGH THE REST OF THE DAY THURSDAY WITH LITTLE PUSH TO CLEAR THEM OUT... HINDERING OUR TEMPERATURE RECOVERY. USED THE BCCONSSHORT FOR THE STARTING POINT OF THE T/TD AND WIND GRIDS THROUGH THE FIRST PART OF TONIGHT AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS FOR THE TERRAIN DIFFERENCES THROUGHOUT THE PERIOD. AS FOR POPS...ENDED UP HIGHER THAN ALL THE GUIDANCE FOR TONIGHT...IN THE SCATTERED RANGE FOR THE WX COVERAGE TERM. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 457 PM EST TUE NOV 18 2014 ONGOING COLD AIR ADVECTION WITH MOISTURE AND STEEP LAPSE RATES IN THE LOW LEVELS WILL KEEP CLOUDS AND A POSSIBILITY OF FLURRIES IN THE FORECAST FOR THURSDAY MORNING. DRIER AIR WILL ARRIVE DURING THE DAY THURSDAY AND SURFACE HIGH PRESSURE SHOULD MOVE IN FROM THE WEST... BRINGING DECREASING CLOUDS. A CHILLY AIR MASS WILL PERSIST THROUGH FRIDAY...BUT BY FRIDAY NIGHT THE HIGH WILL BE TO OUR EAST AND WARM AIR ADVECTION WILL SET IN. MODELS SHOW AN INCREASE IN MOISTURE WITH THE ISENTROPIC LIFT IN OUR NW COUNTIES. IT IS ENOUGH TO WARRANT A SLIGHT CHANCE POP LATE FRIDAY NIGHT AND SATURDAY. TEMPS ALOFT LOOK TO WARM FOR ANYTHING BUT LIQUID TO FALL...BUT SURFACE TEMPS MAY BE NEAR FREEZING AROUND DAWN SATURDAY...AND HAVE INCLUDED A MENTION OF FREEZING RAIN. DURING THE WEEKEND MUCH WARMER AIR IS EXPECTED TO FLOW NORTH AS SURFACE LOW PRESSURE DEVELOPS OVER TX ON SATURDAY AND THEN RAPIDLY DEEPENS AS IT HEADS NE TO THE GREAT LAKES BY SUNDAY NIGHT. OUR FLOW LOOKS TO BE DOWNSLOPE AS THE SYSTEM MOVES BY. THIS WOULD LIMIT OUR DESTABILIZATION...BUT THE STRENGTH OF THE SYSTEM SHOULD STILL BE ENOUGH TO OVERCOME THE DRYING INFLUENCE AND RESULT IN RAIN. THE LOW AND ITS MID/UPPER LEVEL SHORTWAVE TROUGH LIFT OUT INTO CANADA SUNDAY NIGHT AND MONDAY...BUT THE ASSOCIATED SURFACE COLD FRONT TRAILING FROM THE LOW DOES NOT ARRIVE HERE UNTIL LATE MONDAY OR MONDAY EVENING AS ANOTHER LARGE VORTICITY LOBE SWINGS TOWARD US IN A LARGE SYNOPTIC SCALE TROUGH OVER THE CONTINENT. EVEN AFTER THE COLD FRONT PASSES...WE WILL BE UNDER THE UPPER TROUGH WITH A POTENTIAL FOR ADDITIONAL SHORTWAVES TO MOVE THROUGH...BUT WITH POOR CONFIDENCE IN TIMING OR PLACEMENT AT LONG RANGE. THESE FACTORS WILL KEEP A POP IN OUR FORECAST THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 130 AM EST WED NOV 19 2014 THE TAF SITES WILL EXPERIENCE VFR CONDITIONS FOR THE BULK OF THE TAF PERIOD. HOWEVER CLOUD COVER WILL DEVELOP AND THICKEN BY WEDNESDAY EVENING FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA AS A CLIPPER SYSTEM EJECTS OUT OF THE NORTHERN PLAINS AND ACROSS THE LOWER GREAT LAKES REGION. AFTER 00Z A FEW SNOW SHOWERS WILL BE POSSIBLE FROM THIS SYSTEM AND A VCSH WAS ADDED TO THE TAFS. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE REST OF THE NIGHT. THEY ARE THEN EXPECTED TO BE GUSTY TOMORROW FROM THE SOUTH TO SOUTHWEST WITH INCREASING INTENSITY AFTER 15Z TO AROUND 10 KTS SUSTAINED...GUSTING TO AROUND 20 KTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...HAL AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
346 AM EST WED NOV 19 2014 .SYNOPSIS... ISSUED AT 340 AM EST WED NOV 19 2014 LOW PRESSURE PASSING ACROSS THE NORTHERN LAKES WILL BRING ANOTHER ROUND OF LAKE EFFECT SNOW...AT TIMES HEAVY...THROUGH THURSDAY. TEMPERATURES WILL TURN MILDER DURING THE UPCOMING WEEKEND... SETTING THE STAGE FOR SOME RAIN...ESPECIALLY BY SUNDAY AND SUNDAY NIGHT. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 340 AM EST WED NOV 19 2014 ...MORE SIGNIFICANT LAKE EFFECT SNOW ON THE WAY... HIGH IMPACT WEATHER POTENTIAL: WIDESPREAD MOSTLY LIGHT SYNOPTIC SNOW TODAY WITH LAKE ENHANCEMENT NEAR LAKE MICHIGAN...THEN ANOTHER ROUND OF SIGNIFICANT LAKE EFFECT SNOWFALL DEVELOPING TONIGHT. PATTERN SYNOPSIS/FORECAST: UPSTREAM SHORTWAVE TROUGH OVER THE UPPER MISSISSIPPI VALLEY DRIVING A BAND OF WARM AIR ADVECTION SNOW ACROSS THE UPPER MIDWEST. THIS SHORTWAVE FEATURE WILL SERVE TO RE-INFORCE LONGWAVE TROUGH OVER THE EASTERN CONUS AND USHER IN ANOTHER SURGE OF EARLY SEASON ARCTIC AIR WITH LAKE EFFECT SNOW. PRIMARY FORECAST CONCERNS: NUMEROUS. LAKE ENHANCED SNOW ACCUMULATIONS TODAY NEAR THE LAKE MICHIGAN COAST. THEN QUICK TRANSITION TO WEST-NORTHWEST LAKE EFFECT TONIGHT WITH SIGNIFICANT ACCUMULATIONS POSSIBLE. IN ADDITION...GUSTY WINDS MAY CREATE LOW VISIBILITIES AND TRAVEL PROBLEMS WITHIN HEAVIER SNOWSHOWERS. AFOREMENTIONED WARM ADVECTION LIGHT SNOW WILL DEVELOP ACROSS NORTHERN MICHIGAN TODAY WITH BROAD AREA OF ISENTROPIC ASCENT. THIS IS THE EASIEST PORTION OF THE FORECAST...AS ALL AREAS SHOULD SEE AT LEAST SOME SNOW TODAY. H7 MIXING RATIO/S ONLY AROUND 1 G/KG...SO ONLY LIGHT ACCUMULATIONS ON THE ORDER OF 1-2 INCHES. THE EXCEPTION TO THE LIGHTER SNOWS WILL BE CLOSER TO LAKE MICHIGAN...WHERE INCREASING SYNOPTIC FORCING COMBINED WITH PLENTY OF OVER-LAKE INSTABILITY /DELTA T/S IN THE MID-UPPER TEENS/ WILL RESULT IN ENHANCED SNOWFALL. SOME QUESTION MARKS AS TO HOW THE LOW LEVEL FLOW WILL EVOLVE WITH SURFACE LOW OVER NORTHERN LAKE MICHIGAN. WILL LEAN TOWARD HIGH RESOLUTION HRRR FOR LOW LEVEL PATTERN EVOLUTION INTO EARLY THIS AFTERNOON. IMPRESSIVE LOW LEVEL CONVERGENCE SIGNATURE WITH 0-2KM CAPE OF 100 J/KG UP THE SPINE OF LAKE MICHIGAN THIS MORNING WILL BE DRIVEN INLAND TOWARD MANISTEE/BENZIE/LEELANAU COUNTIES AS COLD FRONT SLIDES EAST AND LOW LEVEL FLOW TURNS MORE WESTERLY. OVER WESTERN MACKINAC COUNTY...INITIALLY LOW LEVEL SOUTHWEST FLOW WILL BACK SOUTHEASTERLY THIS MORNING AS WEAK SURFACE LOW MOVES INTO NORTHERN LAKE MICHIGAN. THIS WILL SET UP AN ENHANCED LOW LEVEL CONVERGENCE BAND OF HEAVIER SNOWFALL JUST OFFSHORE OF MACKINAC COUNTY THIS MORNING WHICH WILL BE DRIVEN TOWARD US-2 THIS AFTERNOON WITH NORTHEAST PROGRESSION OF SURFACE LOW. EXPECT LAKE ENHANCED BAND OF HEAVIER SNOW WEST OF THE US-131 CORRIDOR LATE THIS AFTERNOON/EARLY EVENING TO PUSH INLAND THIS EVENING WITH THE FRONT...GRADUALLY WEAKENING AS IT LOSES THE LAKE INFLUENCE. LOW LEVEL FLOW TRANSITIONS RAPIDLY TO WESTERLY BY LATER THIS EVENING AND BUFKIT SOUNDINGS SHOW A QUICK RAMP UP TO THE LAKE EFFECT SNOW MACHINE. THE LAKE EFFECT PARAMETERS REALLY LOOK QUITE SIMILAR TO THE BIG LAKE EFFECT EVENT MONDAY NIGHT/TUESDAY OVER PARTS OF THE AREA AND EXPECT MANY OF THE SAME AREAS TO BE HIT AGAIN WITH SOME SIGNIFICANT LAKE EFFECT ACCUMULATIONS. FORECAST SOUNDINGS SHOW DEEP MOISTURE UP THROUGH H7 AND NO REAL INVERSION...WITH EXCELLENT OMEGA PEGGED SQUARELY IN THE DGZ WITH DELTA T/S OF 20+ DEGC. SNOW WILL BE OF THE DRY/POWDERY VARIETY AND WITH SOME GUSTY WINDS...WILL ONCE AGAIN BE DEALING WITH BLOWING/DRIFTING AND AREAS OF VERY LOW VISIBILITIES. HEADLINES...CHALLENGING TO SAY THE LEAST. LAKE ENHANCED EVENT TODAY WILL BE HANDLED WITH WINTER WEATHER ADVISORIES. WILL ONLY CARRY THE ADVISORY THROUGH THIS EVENING FOR MACKINAC COUNTY...WHERE TRANSITION TO WEST FLOW LAKE EFFECT SHOULD DIMINISH THEIR SNOWFALL. WILL RUN THE ADVISORY FOR MANISTEE/BENZIE/LEELANAU COUNTIES THROUGH 12Z THURSDAY...WILL FULL EXPECTATION THAT THESE HEADLINES WILL BE EXTENDED IN TIME/AREA FOR THURSDAY-THURSDAY NIGHT TO ACCOUNT FOR ONGOING LAKE EFFECT. WITH REGARD TO THE WEST-NORTHWEST FLOW LAKE EFFECT EVENT LATER TONIGHT THROUGH THURSDAY NIGHT...WILL HOIST A LAKE EFFECT SNOW WATCH. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 340 AM EST WED NOV 19 2014 ...ANOTHER SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED THURSDAY... HIGH IMPACT WEATHER POTENTIAL: ANOTHER ROUND OF POTENTIALLY HEAVY LAKE EFFECT SNOW THURSDAY. AREAS OF BLOWING SNOW AND HAZARDOUS DRIVING CONDITIONS EXPECTED. PATTERN SYNOPSIS/CURRENT CONDITIONS: EXTREMELY AMPLIFIED PATTERN CONTINUES FOR JUST A TOUCH LONGER...WITH ONE LAST ARCTIC SHORTWAVE SET TO VISIT OUR AREA LATER TODAY THROUGH THURSDAY. PATTERN CHANGE THEREAFTER IS RATHER AN ABRUPT ONE. AN EXCEPTIONALLY STRONG AND EXTENDED PACIFIC JET EXPECTED TO PUNCH INTO THE WESTERN CONUS LATER THIS WEEK WILL DO THE TRICK. THIS FEATURE ESSENTIALLY REVERSES THE CURRENT PATTERN BY ESTABLISHING WESTERN TROUGHING AND FLOODING MUCH OF THE CONUS WITH MODIFIED PACIFIC ORIGINATED AIR BY THE WEEKEND INTO THE START OF NEXT WEEK. PRIMARY FORECAST CONCERNS/CHALLENGES: NEARLY ALL FOCUS CENTERED ON ANOTHER POTENTIALLY SIGNIFICANT LAKE EFFECT/BLOWING SNOW EVENT THURSDAY. SNOW AMOUNTS...LOCATION OF STEADIEST AND HEAVIEST LAKE BANDING...AND HEADLINE CONSIDERATION ALL NEED ADDRESSING. DETAILS: MORE LAKE EFFECT FUN! WELL ESTABLISHED PRIMARILY WNW FLOW LAKE EFFECT EXPECTED TO BE ONGOING THURSDAY MORNING...WITH FLOW EXPECTED TO VEER MORE NW TO NNW NORTH OF THE BIG BRIDGE WITH PASSAGE OF SURFACE TROUGH DURING THE MORNING. THERMODYNAMIC AND KINEMATIC PROFILES LOOK GOOD TO EXCELLENT ONCE AGAIN...WITH LAKE INDUCED EQL EXCEEDING 10KFT...OMEGA MAX WELL WITHIN THE DGZ...AND GOOD CYCLONIC FLOW/MOISTURE VIA EXITING LOW PRESSURE. OFF LAKE MICHIGAN: WHILE PARAMETERS LOOK TO FALL JUST SHORT OF THIS PAST EVENT...CONDITIONS LOOK PRIME TO PRODUCE ANOTHER 3 TO 6 INCHES...LOCALLY HIGHER...THURSDAY (THIS WILL BE ON TOP OFF WHAT OCCURS WEDNESDAY NIGHT). TARGET AREAS WILL LOOK FAMILIAR...WITH NORTHWEST LOWER LOCATIONS BETWEEN M-32 AND M-68 EXPECTED TO TAKE THE BRUNT OF THE ACTIVITY...WITH LIGHTER SNOW ELSEWHERE. FLOW DOES NOT LOOK QUITE AS STRONG AS THIS PAST SYSTEM...SUGGESTING THE HIGHEST AMOUNTS IN THE MORE TRADITIONAL AREAS ALONG AND WEST OF INTERSTATE 75. OF COURSE...PREDICTING PLACEMENT OF PARTICULAR BANDS NEXT TO IMPOSSIBLE...ALTHOUGH STREAM-LINE WIND ANALYSIS SUGGEST POTENTIAL FOR DOMINATE BANDS ALONG/JUST NORTH OF THE M-32 CORRIDOR AND JUST SOUTHEAST OF LITTLE TRAVERSE BAY. WINDS DO BEGIN TO VEER DURING THE AFTERNOON WITH APPROACH AND PASSAGE OF LAKE REINFORCED TROUGHING. WHILE WINDS WILL NOT BE EXTREME...GUSTS TO 20 TO 25 MPH WILL PRODUCE AREAS OF BLOWING/DRIFTING SNOW...WHICH WILL FURTHER CONTRIBUTE TO VERY LOW VISIBILITIES IN THE HEAVIER SNOW BANDS. DEVELOPMENT OF MORE NEUTRAL TO SLIGHTLY ANTICYCLONIC FLOW AND LOWERING INVERSION/DEPLETING MOISTURE SHOULD BRING SNOW INTENSITY DOWN RATHER RAPIDLY HEADING INTO THURSDAY NIGHT...PERHAPS BRINGING JUST A COUPLE MORE INCHES TO NW FLOW AREAS. LAKE SUPERIOR...PARAMETERS LOOK AS GOOD AS OVER LAKE MICHIGAN...JUST WITH A MUCH QUICKER VEERING OF THE WINDS WITH PASSAGE OF TROUGHING THURSDAY MORNING. WOULD EXPECT A BAND OF ENHANCED SNOW ALONG THIS FEATURE...PERHAPS TARGETING THE SOO BEFORE PUSHING WELL WEST INTO FAR NORTHWEST CHIPPEWA AND MACKINAC COUNTIES FOR LATER IN THE MORNING AND AFTERNOON. SAME SNOW ACCUMULATIONS APPLY...3 TO 6 WITH LOCALLY HIGHER AMOUNTS IN THE TRADITIONAL SNOWBELTS. AS MENTIONED...LOOKS LIKE THE BEST SNOWS WILL EXIT SAULT STE MARIE BY MIDDAY. SNOW LOOKS TO POTENTIALLY PUSH BACK INTO THE SOO THURSDAY NIGHT AS WINDS BACK MORE NORTHWESTERLY...WITH A COUPLE MORE INCHES POSSIBLE. WHILE THE MAJORITY OF TIME WAS SPENT ON THE EARLIER PERIODS...PERUSAL OF LATEST MODEL TRENDS CONTINUES TO ADD INCREASING CONFIDENCE TO A MUCH DESERVED REPRIEVE FROM THE WINTER WEATHER OF LATE...ESPECIALLY BY THE END OF THE WEEKEND INTO THE START OF NEXT WEEK. STILL LOOKING COLD FRIDAY...WITH A FEW LINGERING LIGHT LAKE INDUCED SNOW SHOWERS. MODIFICATION RAMPS UP SATURDAY AS LONG WAVE PATTERN FLATTENS SUBSTANTIALLY AND CURRENT COLD DOME EJECTS WELL TO OUR NORTHEAST. NEARLY ALL HIGH RES DETERMINISTIC AND THEIR ENSEMBLE SUITES AGREE...A RATHER REMARKABLE QUICK EXIT TO SUCH AN ENTRENCHED COLD PATTERN. WAA MAY BE ABLE TO KICK OFF A LITTLE RAIN AND SNOW SATURDAY WHEN HIGHS...READY FOR THIS...ACTUALLY REACH ABOVE FREEZING. ONLY GETS MORE MILD AND WETTER BY SUNDAY INT MONDAY AS LOW PRESSURE MOVES NORTH INTO OR JUST WEST OF OUR AREA. REALLY NO COLD AIR IN SIGHT BY THIS TIME (HIGHS PUSHING THE LOWER 40S SUNDAY AND MONDAY)...SUGGESTING ALL PRECIPITATION FALLING AS RAIN. DEPTH OF THIS SYSTEM STILL IN QUESTION...WITH SOME PROGS SUPPORTING A SUB 980MB LOW...POTENTIALLY LEADING TO SOME RATHER WINDY CONDITIONS. TIMING DEPENDENT OF COURSE...BUT POST-SYSTEM COOL DOWN BEGINS SOMETIME LATER MONDAY/MONDAY NIGHT...BRINGING A RETURN TO BELOW NORMAL TEMPERATURES AND PERHAPS SOME MORE SNOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1145 PM EST TUE NOV 18 2014 W/SW FLOW LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO TARGET THE TIP OF THE MITT AND THE STRAITS. LOW LEVEL WINDS WILL GRADUALLY BACK TO THE S/SW ON WEDNESDAY AHEAD OF ANOTHER AREA OF LOW PRESSURE LIFTING INTO THE GREAT LAKES REGION. THIS SYSTEM WILL PRODUCE ANOTHER WAVE OF SYNOPTICALLY DRIVEN SNOW FOR ALL OF NRN LWR MICHIGAN...AND WILL ENHANCE ONGOING S/SW FLOW LAKE EFFECT SNOW SHOWERS IMPACTING PORTIONS OF FAR NW LWR MICHIGAN...THE STRAITS AND MACKINAC COUNTY. OVERALL CONDITIONS WITHIN ANY SNOW SHOWERS WILL REMAIN MVFR/IFR... WITH MAINLY VFR CONDITIONS AWAY FROM SNOW SHOWER ACTIVITY. && .MARINE... ISSUED AT 340 AM EST WED NOV 19 2014 A STORM SYSTEM WILL MOVE OUT OF THE UPPER MIDWEST AND INTO THE GREAT LAKES THROUGH TONIGHT...PUSHING A COLD FRONT THROUGH THE AREA. THE GRADIENT WILL TIGHTEN WITH FROPA...WITH WINDS SHIFTING TO THE WEST. GALE FORCE GUSTS WILL BE POSSIBLE ON PORTIONS OF LAKE MICHIGAN INTO EARLY THURSDAY...WITH SMALL CRAFT ADVISORIES ELSEWHERE. ADDITIONAL SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR LAKES HURON AND SUPERIOR TONIGHT INTO THURSDAY NIGHT. WEST/NORTHWEST FLOW LAKE EFFECT SNOW WILL DEVELOP LATER TONIGHT AND CONTINUE INTO THURSDAY...RESULTING IN AREAS OF REDUCED VISIBILITIES ALONG THE COASTLINE. QUIETER WEATHER AND HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES TO END THE WEEK. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 1 AM EST THURSDAY FOR MIZ015. WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ020-025- 031. LAKE EFFECT SNOW WATCH FROM THIS EVENING THROUGH LATE THURSDAY NIGHT FOR MIZ008-016-017-019-021-022. LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LHZ345. LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LMZ323-341. GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LMZ342-344>346. LS...NONE. && $$ SYNOPSIS...MSB SHORT TERM...KEYSOR LONG TERM...MSB AVIATION...MLR MARINE...KEYSOR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1219 AM EST WED NOV 19 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 421 PM EST TUE NOV 18 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A HIGHLY AMPLIFIED PATTERN OVER NAMERICA...FEATURING A STRONG RIDGE OVER THE WRN PART OF THE CONTINENT AND A DEEP TROF EXTENDING S DOWN THE MISSISSIPPI RIVER VALLEY. WITH THE TROF SLOWLY SHIFTING E...SFC WINDS ARE IN THE PROCESS OF BACKING...AND THUS LES IS SHIFTING AS WELL. LES IS NOW CONFINED TO AREAS FROM THE PORCUPINE MTNS NORTHWARD AND ROUGHLY EAST OF A MUNISING-GERMFASK LINE. UPSTREAM 12Z SOUNDINGS AT KINL/CWPL STILL SHOWED MOISTURE EXTENDING UP TO AROUND 800MB...SO LES INTENSITY REMAINS MDT/HVY IN THE MAIN BANDS...ESPECIALLY WITH SHORT TERM MODEL GUIDANCE STILL SHOWING A NICE INTERSECTION OF BEST UPWARD MOTION CENTERED IN THE DGZ. SHORT TERM FCST CONTINUES TO RESEMBLE CONDITIONS IN THE HEART OF WINTER. WITH ONE LAKE EFFECT EVENT CURRENTLY WINDING DOWN...NEXT SYSTEM THAT WILL BRING ANOTHER ROUND OF MDT TO HVY LES WILL BE MOVING INTO THE UPPER GREAT LAKES ALREADY ON WED. TONIGHT...PAIR OF SHORTWAVES WILL BE DROPPING SSE THRU SASKATCHEWAN/MANITOBA (SECOND STRONGER THAN THE LEAD). AS A RESULT...WINDS WILL CONTINUE TO BACK TONIGHT...REACHING SW BY 12Z WED. SO...EXPECT LAKE SUPERIOR LES TO SHIFT COMPLETELY OFFSHORE OF UPPER MI DURING THE OVERNIGHT. AT LEAST THRU 12Z...WINDS WON`T HAVE ENOUGH SOUTHERLY COMPONENT TO BRING ANY LES CONCERNS OFF LAKE MICHIGAN INTO SCHOOLCRAFT/LUCE COUNTIES. THERE WILL BE SOME ENHANCED CONVERGENCE ON THE BACK EDGE OF THE LINGERING LES WHERE BACKING WINDS INTERSECT WITH WINDS THAT STAY MORE VEERED LONGER OVER THE RELATIVELY WARM WATERS OF THE LAKE. AS A RESULT...THE LAST SNOW BAND LIFTING N ACROSS WRN UPPER MI TONIGHT AND THE LAST SHIFTING E ACROSS THE ERN FCST AREA THIS EVENING WILL BE FAIRLY HVY. OVER THE W...THIS BAND MIGHT PROVIDE A QUICK INCH OR TWO OF SNOW...ESPECIALLY ACROSS THE KEWEENAW AS FETCH ACROSS THE WATER INCREASES AS THE ORIENTATION OF THE BAND BECOMES W-E THEN WSW-ENE UNDER BACKING WINDS. AN INCH OR TWO OF SNOW IS ALSO LIKELY OVER THE NE FCST AREA BEFORE LES SHIFTS OFFSHORE. AS LAKE EFFECT CLOUDS SHIFT N...THERE SHOULD BE A PERIOD OF PARTIAL CLEARING BEFORE CLOUDS BEGIN TO OVERSPREAD THE AREA AHEAD OF THE INCOMING SHORTWAVES. HOWEVER...THAT`S NOT CERTAIN GIVEN THE LARGE MASS OF STRATOCU TO THE W. WITH MUCH OF THOSE CLOUDS PRESENT BEFORE SUNRISE TODAY...NOT ALL OF THOSE CLOUDS WERE DIURNALLY DRIVEN...SO THEY MAY BE SLOWER TO DISSIPATE TONIGHT. FOR NOW... DIDN`T GO TOO LOW WITH MINS. TRADITIONAL COLD SPOTS MAY SLIP JUST BELOW 0F. ALTHOUGH DEEP LAYER FORCING SPREADS INTO WRN UPPER MI LATE TONIGHT IN ASSOCIATION WITH APPROACHING SHORTWAVES...LOW-LEVELS ARE SLOW TO MOISTEN. WILL CONTINUE TO CARRY JUST SCHC POPS ALONG THE WI BORDER AND LOW CHC POPS OVER THE W TOWARD KIWD LATE TONIGHT. ON WED....MAIN SHORTWAVE WILL BE DIVING INTO THE UPPER GREAT LAKES. AT THE SFC...ASSOCIATED LOW PRES TROF WILL ALSO SWING INTO THE UPPER GREAT LAKES AND THEN BEGIN TO DEEPEN OVER THE WARMER WATERS. AHEAD OF THE DEEPENING SFC TROF...LOW-LEVEL WINDS WILL CONTINUE TO BACK... BRINGING CONCERNS FOR LAKE ENHANCED SNOW SPREADING N AND W OFF LAKE MICHIGAN INTO SCHOOLCRAFT/LUCE COUNTIES. OF THE HIGH RES MODELS... THE NAM/GEM ARE A LITTLE SLOWER AND ALLOW WINDS TO BACK ENOUGH TO BRING HEAVIER SNOW INTO THE FAR ERN FCST AREA IN THE MID TO LATE AFTN. THE NCEP ARW AND NMM ARE FASTER AND NEVER REALLY QUITE BACK THE WINDS SUFFICIENTLY TO BRING SNOW FAR ENOUGH W. OPTED TO LEAN TOWARD THE NAM/GEM WITH THE IDEA OF FALLING PRES ALONG TROF HELPING TO BACK WINDS/SLOW TROF DOWN...ESPECIALLY WITH THE MAGNITUDE OF THE COLD AIR ALREADY OVER THE AREA THAT WILL ENHANCE LATENT/SENSIBLE HEATING OVER THE LAKES. FOR NOW...PAINTED AS MUCH AS 2-4 INCHES OF SNOW IN FAR SE SCHOOLCRAFT COUNTY AND SE LUCE COUNTY BY 00Z THU. COULD BE QUITE A BIT MORE IF WINDS BACK ENOUGH AND THEN DON`T SHIFT FOR SEVERAL HRS. TO THE W...EXPECT HVY LAKE ENHANCED SNOW TO DEVELOP ALONG SFC TROF AXIS AS IT SWINGS ACROSS WRN LAKE SUPERIOR. THAT HVY SNOW WILL PUSH ONSHORE IN THE AFTN...PROVIDING 2 TO 4 INCHES OF ACCUMULATION. ELSEWHERE...EXPECT SOME -SN IN ASSOCIATION WITH SHORTWAVE. ACCUMULATIONS SHOULD GENERALLY BE AROUND 1 INCH. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 441 PM EST TUE NOV 18 2014 NEW LAKE EFFECT SNOW ADVISORIES WILL NEED TO BE HOISTED ONCE AGAIN IN THE NW WIND SNOW BELTS FOR WEDNESDAY LATE AFTERNOON/EARLY EVENING THROUGH MUCH OF THURSDAY. MAY GET CLOSE TO THE 24 HOUR /12IN OR MORE/ WARNING CRITERIA IF BANDED PRECIP STAYS OVER E ALGER AND N PORTIONS OF LUCE COUNTY. WILL NOT HOIST ANY NEW HEADLINES AT THIS TIME...TO LIMIT CONFUSION WITH THE ONGOING ADVISORIES OVER THE E HALF OF UPPER MI. PERSISTENT NW FLOW FROM 00Z THURSDAY THROUGH 00Z FRIDAY WILL KEEP MODERATE TO AT TIMES HEAVY LES GOING...AS NOTED ABOVE...BEHIND THE EXITING SFC LOW OVER N AND E LAKE SUPERIOR AT 00Z THURSDAY. THE LOW WILL DEEPEN ACROSS THE S ONTARIO/QUEBEC BORDER AT 12Z THURSDAY...WITH THE SFC TROUGH LINGERING ACROSS THE AREA. THE LARGE AREA OF HIGH PRESSURE EXTENDING FROM THE N PLAINS THROUGH THE GULF COAST THURSDAY AFTERNOON WILL PUSH A RIDGE ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT THROUGH FRIDAY...BEFORE THE PARENT HIGH EXITS TO THE MID ATLANTIC. THIS WILL PUSH THE RIDGE OVER THE LOWER GREAT LAKES. AT THAT POINT WE WILL BRIEFLY SAY GOODBYE TO OUR COLD WINTER WEATHER. STRONG WAA WILL BE THE RULE FRIDAY NIGHT IN ADVANCE OF LOW PRESSURE TO THE W /FROM A SFC LOW OVER MANITOBA...AND ANOTHER ONE ORGANIZING ACROSS THE S PLAINS/. LOOK FOR SFC TEMPS TO RISE INTO THE 30S SATURDAY...SUNDAY...AND MONDAY. THE INITIAL LOW OVER MANITOBA WILL SKIRT ACROSS ONTARIO INTO S HUDSON BAY SATURDAY...WITH THE SFC RIDGE ERODING ACROSS UPPER MI. FCST SOUNDINGS INDICATE THE POTENTIAL FOR FREEZING DRIZZLE /OR MORE LIKELY FREEZING RAIN IF THE HIGHER QPF LIKE THAT FROM THE 18/12Z ECMWF PAN OUT. THE GFS IS LESS ROBUST...SO WILL ONLY ADD THE MENTION FOR NOW AND WAIT UNTIL FCST SOLUTIONS COME TO A BETTER CONSENSUS BEFORE HIGHLIGHTING MORE THAN JUST LIGHT PRECIP /FREEZING DRIZZLE/. THE NEXT CONCERN FOR THE PERIOD WILL BE THE INTERACTION/PHASING OF THE S STREAM LOW EJECTING OUT OF THE S PLAINS SUNDAY...AND AN ADDITIONAL LOW PUSHING ACROSS THE ND/CANADA BORDER SUNDAY MORNING. LOOK FOR THE S LOW TO PUSH ACROSS LAKE MI/ILLINOIS BY 00Z MONDAY...AND CONTINUE TO DEEPEN ACROSS E UPPER MI/W LAKE HURON BY DAYBREAK MONDAY. GIVEN WHERE THIS SYSTEM IS COMING FROM...RAIN WILL BE POSSIBLE INITIALLY. HOW MUCH OF THAT FALLS AS FREEZING RAIN/OVER OUR SNOW PACK IS IN QUESTION. PRECIP WILL TRANSITION BACK TO ALL SNOW SUNDAY NIGHT-MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1217 AM EST WED NOV 19 2014 MVFR CIGS CONTINUE OVER KIWD AND KCMX THIS MORNING AHEAD OF NEXT SHORTWAVE/SFC LOW DROPPING INTO THE REGION. WHILE KSAW CURRENTLY VFR...THE LOWER CIGS WILL WORK THEIR WAY IN LATE OVERNIGHT. SNOW WILL ONCE AGAIN SPREAD INTO THE AREA AHEAD OF THE SHORT WAVE WITH VISIBILITIES BORDERLINE IFR AT KIWD AT TIMES. KSAW VISIBILITIES TO STAY MVFR WITH DOWNSLOPE WINDS. AS WINDS SHIFT TO THE WEST...SNOW SHOWERS TAPER OFF AT KIWD DUE TO DIMINISHED FETCH BUT INCREASED FETCH...GUSTY WINDS ALONG WITH TERRAIN INFLUENCES AT KCMX TO PRODUCE IFR VISIBILITIES FOR A TIME IN THE AFTERNOON TO EARLY EVENING THERE. LATEST NAM BUFKIT SHOWS INCREASING INVERSION HEIGHTS LATE IN THE FORECAST AND HAVE FOLLOWED THIS TREND WITH IMPROVING CIGS AND VISIBILITIES...BUT MVFR CONDITIONS TO REMAIN AT KIWD AND KCMX WHILE KSAW CIGS DO RISE AS DOWNSLOPE INCREASES AS WINDS SHIFT WEST. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 PM EST TUE NOV 18 2014 THE BRIEF RIDGE ACROSS LAKE SUPERIOR THIS EVENING WILL BE REPLACED BY TROUGH WEDNESDAY MORNING...THAT WILL DEEPEN WEDNESDAY EVENING ACROSS N AND E LAKE SUPERIOR. OUR INITIAL GUSTS NEARING 20-30KTS WILL BE ON THE INCREASE AGAIN WEDNESDAY NIGHT THROUGH EARLY THURSDAY AFTERNOON...WITH W-NW GALE FORCE GUSTS NEARING 35KTS. A GALE WATCH HAS BEEN ISSUED FOR THIS PERIOD ACROSS PORTIONS OF CENTRAL AND E LAKE SUPERIOR. EXPECT THE LOW TO EXIT ACROSS S QUEBEC ON THURSDAY. LOOK FOR A RIDGE ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT THROUGH FRIDAY...BEFORE SHIFTING TO THE LOWER GREAT LAKES LATE FRIDAY AFTERNOON THROUGH FRIDAY EVENING. LOW PRESSURE ACROSS MANITOBA FRIDAY NIGHT WILL SWING ACROSS ONTARIO AND SOUTHERN HUDSON BAY SATURDAY...WITH THE RIDGE ACROSS LAKE SUPERIOR WEAKENING SLIGHTLY. EXPECT A VERY DEEP LOW ACROSS THE MID MS VALLEY SUNDAY MORNING TO PUSH OVER THE UPPER GREAT LAKES SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR LSZ266. GALE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR LSZ264. GALE WATCH FROM THIS EVENING THROUGH LATE TONIGHT FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...RJT MARINE...KF
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
752 AM CST WED NOV 19 2014 .SHORT TERM... 335 AM CST TODAY THROUGH FRIDAY... MAIN FOCUS IN NEAR TERM IS WITH CLIPPER-TYPE SYSTEM MOVING THROUGH THE REGION THIS MORNING...AND THE POTENTIAL FOR SOME LIGHT ACCUMULATING SNOW MAINLY ACROSS FAR NORTHERN/NORTHEAST IL. OTHER HIGHLIGHTS...OR LOW LIGHTS AS THE CASE MAY BE...THROUGH FRIDAY ARE CONTINUED SUB-NORMAL CHILLY TEMPERATURES AND THE POTENTIAL FOR SOME LIGHT FREEZING RAIN FRIDAY NIGHT INTO EARLY SATURDAY MORNING AHEAD OF A SYSTEM WHICH WILL BRING RAIN AND WARMER WEATHER OVER THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY DEPICTS A SHORT-WAVE DIGGING SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY AND APPROACHING WI/IL AT 0830Z. SURFACE TROUGH REFLECTION WAS OVER SOUTHERN MN/EAST CENTRAL IA...WITH FAIRLY IMPRESSIVE SURFACE PRESSURE FALLS SPREADING INTO SOUTHERN WI/IL AND BACKING WINDS TO THE SOUTH AND RAISING TEMPS. RADAR RETURNS FROM MID-LEVEL CLOUDS HAVE DEVELOPED SOUTHEAST FROM TWIN CITIES AREA...THOUGH DRY LOW LEVEL AIR SO FAR HAS SLOWED DEVELOPMENT OF SNOW AT THE SURFACE. TRACK OF SYSTEM...RADAR TRENDS AND HIGH-RES HRRR GUIDANCE ALL INDICATE BEST POTENTIAL FOR MEASURABLE SNOW THROUGH THE EARLY MORNING HOURS WILL BE ALONG A ROUGHLY MSP-MKE CORRIDOR...WITH GENERALLY LIGHT AMOUNTS OF AN INCH OR LESS EXPECTED ACROSS FAR NORTHEAST IL AND PARTS OF NORTHERN IN. FORECAST SOUNDINGS INDICATE DRY AIR ARRIVING IN MID-LEVELS BY MID-LATE MORNING AND LIMITING BEST FORCING FOR SNOW TO A ONLY A FEW HOURS THIS AM. SURFACE TROUGH PASSES MID-DAY...WITH RENEWED COLD ADVECTION AND EXTENSIVE UPSTREAM CLOUDINESS SUPPORTING SCATTERED FLURRIES THIS AFTERNOON AS LOW-LEVEL THERMAL PROFILES COOL AGAIN. MOISTURE BECOMES VERY SHALLOW TONIGHT AND THURSDAY...DECREASING POTENTIAL FOR FLURRIES DESPITE ANOTHER DIGGING SHORT WAVE ACROSS THE WESTERN LAKES. THE MAIN LARGE-SCALE UPPER TROUGH AXIS THEN SHIFTS EAST THURSDAY NIGHT...ALLOWING SURFACE HIGH PRESSURE TO SPREAD EAST ACROSS THE AREA BY FRIDAY MORNING. TEMPERATURES WERE RISING INTO THE 20S WITH THE SOUTH WINDS THIS MORNING...WITH HIGHS EXPECTED TO TOP OUT IN THE MID 20S TO LOW 30S TODAY WITH THE MILDEST TEMPS ACROSS THE FAR EAST/SOUTHEAST CWA. COLDER TEMPS AGAIN TONIGHT AND THURSDAY...WITH THE COLDEST EXPECTED EARLY FRIDAY MORNING IN THE VICINITY OF THE SURFACE RIDGE AXIS. LOWS IN THE SINGLE DIGITS TO LOWER TEENS ARE LIKELY FRIDAY MORNING WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. MUCH-TOUTED CHANGE IN THE UPPER PATTERN WILL BE UNDERWAY FRIDAY... AS FLOW DE-AMPLIFIES AND UPPER TROUGH MOVES ACROSS THE SOUTHWESTERN STATES AND ACROSS THE CENTRAL AND SOUTHERN ROCKIES FRIDAY NIGHT. ALONG WITH A DISTURBANCE MOVING ACROSS CENTRAL CANADA...THIS WILL SET UP SOUTHERLY RETURN FLOW INTO THE REGION FRIDAY NIGHT WITH ASSOCIATED WARM/MOIST ADVECTION. MODELS CONTINUE TO INDICATE DEVELOPMENT OF SOME LIGHT PRECIP OVERNIGHT...WITH FORECAST SOUNDINGS INDICATING ELEVATED WARM LAYER TEMPS APPROACHING +5C WHILE SFC TEMPS ARE BELOW FREEZING. THIS SUPPORTS THE POTENTIAL FOR SOME LIGHT FREEZING RAIN OR SLEET FRIDAY NIGHT...BEFORE WARM ADVECTION EVENTUALLY RAISES SURFACE TEMPS ABOVE FREEZING ON SATURDAY. MODELS HAVE TRENDED A LITTLE SLOWER WITH ARRIVAL OF LIGHT PRECIP...THOUGH ALSO SOMEWHAT COLDER INITIALLY AT THE SURFACE. WILL CONTINUE TO MENTION POTENTIAL FOR FREEZING RAIN/SLEET AND WILL HAVE TO MONITOR TRENDS FOR THE POTENTIAL OF SOME LIGHT ICE ACCUMULATION LATER FRIDAY NIGHT INTO EARLY SATURDAY. RATZER && .LONG TERM... 335 AM CST SATURDAY THROUGH TUESDAY... LONGER RANGE MODEL SOLUTIONS CONTINUE TO LIFT SOUTHWESTERN TROUGH TOWARD THE AREA OVER THE WEEKEND...WITH LOW LEVELS QUICKLY WARMING ABOVE FREEZING SATURDAY MORNING AND CHANGING ANY MIXED PRECIP OVER TO RAIN. 00Z GFS/ECMWF HAVE COME INTO BETTER AGREEMENT IN TIMING THE NEGATIVELY-TILTED SOUTHWESTERN SHORT WAVE AND DEEPENING SURFACE LOW TO LIFT ACROSS THE FORECAST AREA SUNDAY AFTERNOON/EVENING...WITH TEMPS RISING INTO THE BALMY 45-50 RANGE. SOME DIFFERENCES REMAIN WITH THE DETAILS OF PHASING THIS SYSTEM WITH A NORTHERN STREAM DEVELOPING CLOSED UPPER LOW OVER THE REGION SUNDAY NIGHT INTO MONDAY...THOUGH REASONABLY SIMILAR IN THE IDEA OF MILD WITH RAIN/SHOWERS EVENTUALLY GIVING WAY TO LIGHTER RAIN/SNOW TRANSITION MONDAY-MONDAY NIGHT AND TO LINGERING SNOW SHOWERS TUESDAY AS WE SHIFT BACK TO A DEEP EASTERN CONUS UPPER TROUGH AND COLDER WEATHER EARLY NEXT WEEK. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * FLURRIES THIS MORNING. * LIGHT SNOW SHOWERS MIDDAY INTO EARLY AFTERNOON WITH MVFR CIGS/VSBY. * CIGS TRENDING TO MVFR THIS AFTERNOON. * GUSTY WEST WINDS RETURN LATE THIS MORNING WITH PEAK GUSTS ARND 25-28 KT THIS AFTN. KMD //DISCUSSION...UPDATED 14Z... MORNING SNOW SHOULD LARGELY REMAIN VFR WITH MODERATE SNOWS CONFINED TO FAR NORTHEAST ILLINOIS. THERE IS A BAND OF SNOW SHOWERS BACK IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA THAT HAS A HISTORY OF 3-5SM VISIBILITY FOR A 2-3 HOUR PERIOD. THE FORCING ASSOCIATED WITH THIS ACTIVITY COMES THROUGH NORTHERN ILLINOIS MIDDAY INTO EARLY AFTERNOON. IT DOES WEAKEN SOMEWHAT AS IT PROGRESSES SOUTH AND EAST...BUT WE WILL HAVE MORE UNSTABLE LOW LEVELS WHICH WILL SUPPORT SOME LIGHT SNOW SHOWERS. HAVE ATTEMPTED TO TIME THESE IN FOR THE MOST LIKELY PERIOD OF LOWER MVFR CONDITIONS. KMD PREVIOUS DISCUSSION FROM 12Z... RADAR SHOWS DECENT REFLECTIVY ACROSS NORTHERN IL AND NW INDIANA BUT DRY LOW LEVELS ARE IMPEDING SNOW FROM REACHING THE SURFACE. AS SUCH BACKED OF SNOW FOR THIS MORNING AND EXPECTING MOSTLY FLURRIES THROUGH THE EARLY AFTERNOON. MAY SEE A BRIEF HEAVIER SNOW SHOWER THAT BRINGS DOWN VSBY AND CIGS...BUT NOT OVERLY CONFIDENT. OUTSIDE OF THE HEAVIER SNOW...CIGS AND VSBY WILL BE VFR. SSE WINDS BCM WEST BY MID MORNING AND GUST TO ARND 25 KT THIS AFTN. GUSTY CONDITIONS REMAIN OVERNIGHT WITH GUSTS SLOWLY DIMINISHING OVERNIGHT. JEE //ORD AND MDW CONFIDENCE...UPDATED 14Z... * HIGH CONFIDENCE IN WINDS AND CIG FCST. * MEDIUM-HIGH CONFIDENCE IN A PERIOD OF SNOW SHOWERS WITH MVFR VSBY...MEDIUM ON TIMING. * MEDIUM-HIGH FOR PERIODS OF MVFR CIGS THIS AFTERNOON. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...CHANCE OF A WINTRY MIX OVERNIGHT. IFR LIKELY OVERNIGHT. SATURDAY...WINTRY MIX BCMG RAIN. IFR LIKELY. SUNDAY...RAIN AND IFR LIKELY. MONDAY...CHC -RASN BCMG -SN. MVFR TO IFR CIGS. TUESDAY...VFR. JEE && .MARINE... 210 AM CST HEADLINES...DID NOT MAKE ANY CHANGES TO THE SMALL CRAFT ADVISORY BUT DID UPGRADE THE OPEN WATER GALE WATCH TO A WARNING. MAY SEE WINDS DIMINISH TO BELOW GALES FASTER THAN THE WARNING WOULD INDICATE...BUT HAVE LIMITED CONFIDENCE IN HOW LONG GALES WILL LAST SO LEFT THE END TIME AS IS. A TROUGH OF LOW PRESSURE MOVES OVER THE LAKE THIS AFTERNOON WITH WEST WINDS BECOMING SOUTH OVER THE NEXT FEW HOURS. WINDS RETURN TO WEST BEHIND THE TROUGH THIS AFTERNOON AND INCREASE TO GALES BY THE LATE AFTERNOON. GALES CONTINUE OVERNIGHT INTO THURSDAY MORNING...BUT THEY MAY COME DOWN BELOW GALE FORCE SOONER THAN THE WARNING INDICATES. NW WINDS TO 30 KT BECOME WEST 10-20 KT BY FRIDAY MORNING. HIGH PRESSURE PASSES SOUTH OF THE LAKE LATE THURSDAY NIGHT AND FRIDAY MORNING WITH LIGHT WINDS BECOMING SOUTH TO SOUTHWEST TO 20 KT BY FRIDAY EVENING. WINDS INCREASE TO 30 KT FRIDAY NIGHT AS THE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A LOW OVER NORTHERN QUEBEC. SOUTH WINDS PERSIST THROUGH SATURDAY NIGHT BEFORE BECOMING SOUTHEAST SUNDAY AHEAD OF THE NEXT LOW. GUIDANCE DIFFERS ON STRONG THE LOW WILL BE AND ITS EXACT PATH BUT GUIDANCE MEMBERS DO AGREE THAT THE LAKE WILL MOVE OVER THE LAKE AT SOME POINT SUNDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM WEDNESDAY TO 9 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
555 AM CST WED NOV 19 2014 .SHORT TERM... 335 AM CST TODAY THROUGH FRIDAY... MAIN FOCUS IN NEAR TERM IS WITH CLIPPER-TYPE SYSTEM MOVING THROUGH THE REGION THIS MORNING...AND THE POTENTIAL FOR SOME LIGHT ACCUMULATING SNOW MAINLY ACROSS FAR NORTHERN/NORTHEAST IL. OTHER HIGHLIGHTS...OR LOW LIGHTS AS THE CASE MAY BE...THROUGH FRIDAY ARE CONTINUED SUB-NORMAL CHILLY TEMPERATURES AND THE POTENTIAL FOR SOME LIGHT FREEZING RAIN FRIDAY NIGHT INTO EARLY SATURDAY MORNING AHEAD OF A SYSTEM WHICH WILL BRING RAIN AND WARMER WEATHER OVER THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY DEPICTS A SHORT-WAVE DIGGING SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY AND APPROACHING WI/IL AT 0830Z. SURFACE TROUGH REFLECTION WAS OVER SOUTHERN MN/EAST CENTRAL IA...WITH FAIRLY IMPRESSIVE SURFACE PRESSURE FALLS SPREADING INTO SOUTHERN WI/IL AND BACKING WINDS TO THE SOUTH AND RAISING TEMPS. RADAR RETURNS FROM MID-LEVEL CLOUDS HAVE DEVELOPED SOUTHEAST FROM TWIN CITIES AREA...THOUGH DRY LOW LEVEL AIR SO FAR HAS SLOWED DEVELOPMENT OF SNOW AT THE SURFACE. TRACK OF SYSTEM...RADAR TRENDS AND HIGH-RES HRRR GUIDANCE ALL INDICATE BEST POTENTIAL FOR MEASURABLE SNOW THROUGH THE EARLY MORNING HOURS WILL BE ALONG A ROUGHLY MSP-MKE CORRIDOR...WITH GENERALLY LIGHT AMOUNTS OF AN INCH OR LESS EXPECTED ACROSS FAR NORTHEAST IL AND PARTS OF NORTHERN IN. FORECAST SOUNDINGS INDICATE DRY AIR ARRIVING IN MID-LEVELS BY MID-LATE MORNING AND LIMITING BEST FORCING FOR SNOW TO A ONLY A FEW HOURS THIS AM. SURFACE TROUGH PASSES MID-DAY...WITH RENEWED COLD ADVECTION AND EXTENSIVE UPSTREAM CLOUDINESS SUPPORTING SCATTERED FLURRIES THIS AFTERNOON AS LOW-LEVEL THERMAL PROFILES COOL AGAIN. MOISTURE BECOMES VERY SHALLOW TONIGHT AND THURSDAY...DECREASING POTENTIAL FOR FLURRIES DESPITE ANOTHER DIGGING SHORT WAVE ACROSS THE WESTERN LAKES. THE MAIN LARGE-SCALE UPPER TROUGH AXIS THEN SHIFTS EAST THURSDAY NIGHT...ALLOWING SURFACE HIGH PRESSURE TO SPREAD EAST ACROSS THE AREA BY FRIDAY MORNING. TEMPERATURES WERE RISING INTO THE 20S WITH THE SOUTH WINDS THIS MORNING...WITH HIGHS EXPECTED TO TOP OUT IN THE MID 20S TO LOW 30S TODAY WITH THE MILDEST TEMPS ACROSS THE FAR EAST/SOUTHEAST CWA. COLDER TEMPS AGAIN TONIGHT AND THURSDAY...WITH THE COLDEST EXPECTED EARLY FRIDAY MORNING IN THE VICINITY OF THE SURFACE RIDGE AXIS. LOWS IN THE SINGLE DIGITS TO LOWER TEENS ARE LIKELY FRIDAY MORNING WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. MUCH-TOUTED CHANGE IN THE UPPER PATTERN WILL BE UNDERWAY FRIDAY... AS FLOW DE-AMPLIFIES AND UPPER TROUGH MOVES ACROSS THE SOUTHWESTERN STATES AND ACROSS THE CENTRAL AND SOUTHERN ROCKIES FRIDAY NIGHT. ALONG WITH A DISTURBANCE MOVING ACROSS CENTRAL CANADA...THIS WILL SET UP SOUTHERLY RETURN FLOW INTO THE REGION FRIDAY NIGHT WITH ASSOCIATED WARM/MOIST ADVECTION. MODELS CONTINUE TO INDICATE DEVELOPMENT OF SOME LIGHT PRECIP OVERNIGHT...WITH FORECAST SOUNDINGS INDICATING ELEVATED WARM LAYER TEMPS APPROACHING +5C WHILE SFC TEMPS ARE BELOW FREEZING. THIS SUPPORTS THE POTENTIAL FOR SOME LIGHT FREEZING RAIN OR SLEET FRIDAY NIGHT...BEFORE WARM ADVECTION EVENTUALLY RAISES SURFACE TEMPS ABOVE FREEZING ON SATURDAY. MODELS HAVE TRENDED A LITTLE SLOWER WITH ARRIVAL OF LIGHT PRECIP...THOUGH ALSO SOMEWHAT COLDER INITIALLY AT THE SURFACE. WILL CONTINUE TO MENTION POTENTIAL FOR FREEZING RAIN/SLEET AND WILL HAVE TO MONITOR TRENDS FOR THE POTENTIAL OF SOME LIGHT ICE ACCUMULATION LATER FRIDAY NIGHT INTO EARLY SATURDAY. RATZER && .LONG TERM... 335 AM CST SATURDAY THROUGH TUESDAY... LONGER RANGE MODEL SOLUTIONS CONTINUE TO LIFT SOUTHWESTERN TROUGH TOWARD THE AREA OVER THE WEEKEND...WITH LOW LEVELS QUICKLY WARMING ABOVE FREEZING SATURDAY MORNING AND CHANGING ANY MIXED PRECIP OVER TO RAIN. 00Z GFS/ECMWF HAVE COME INTO BETTER AGREEMENT IN TIMING THE NEGATIVELY-TILTED SOUTHWESTERN SHORT WAVE AND DEEPENING SURFACE LOW TO LIFT ACROSS THE FORECAST AREA SUNDAY AFTERNOON/EVENING...WITH TEMPS RISING INTO THE BALMY 45-50 RANGE. SOME DIFFERENCES REMAIN WITH THE DETAILS OF PHASING THIS SYSTEM WITH A NORTHERN STREAM DEVELOPING CLOSED UPPER LOW OVER THE REGION SUNDAY NIGHT INTO MONDAY...THOUGH REASONABLY SIMILAR IN THE IDEA OF MILD WITH RAIN/SHOWERS EVENTUALLY GIVING WAY TO LIGHTER RAIN/SNOW TRANSITION MONDAY-MONDAY NIGHT AND TO LINGERING SNOW SHOWERS TUESDAY AS WE SHIFT BACK TO A DEEP EASTERN CONUS UPPER TROUGH AND COLDER WEATHER EARLY NEXT WEEK. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * FLURRIES INTO EARLY THIS AFTN. * LIGHT SNOW IS POSSIBLE OVER THE NEXT COUPLE OF HOURS. CIG AND VSBY RESTRICTIONS WILL ONLY BE WITH THE HEAVIER PERIODS OF SNOW. * GUSTY WEST WINDS RETURN LATE THIS MORNING WITH PEAK GUSTS ARND 25 KT THIS AFTN. JEE //DISCUSSION...UPDATED 12Z... RADAR SHOWS DECENT REFLECTIVY ACROSS NORTHERN IL AND NW INDIANA BUT DRY LOW LEVELS ARE IMPEDING SNOW FROM REACHING THE SURFACE. AS SUCH BACKED OF SNOW FOR THIS MORNING AND EXPECTING MOSTLY FLURRIES THROUGH THE EARLY AFTERNOON. MAY SEE A BRIEF HEAVIER SNOW SHOWER THAT BRINGS DOWN VSBY AND CIGS...BUT NOT OVERLY CONFIDENT. OUTSIDE OF THE HEAVIER SNOW...CIGS AND VSBY WILL BE VFR. SSE WINDS BCM WEST BY MID MORNING AND GUST TO ARND 25 KT THIS AFTN. GUSTY CONDITIONS REMAIN OVERNIGHT WITH GUSTS SLOWLY DIMINISHING OVERNIGHT. JEE //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE IN WINDS AND CIG FCST. * LOW CONFIDENCE IN PERIOD OF LIGHT SNOW OCCURRING. HIGH CONFIDENCE IN LOWER VSBY AND CIGS WITH HEAVIER SNOW. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...CHANCE OF A WINTRY MIX OVERNIGHT. IFR LIKELY OVERNIGHT. SATURDAY...WINTRY MIX BCMG RAIN. IFR LIKELY. SUNDAY...RAIN AND IFR LIKELY. MONDAY...CHC -RASN BCMG -SN. MVFR TO IFR CIGS. TUESDAY...VFR. JEE && .MARINE... 210 AM CST HEADLINES...DID NOT MAKE ANY CHANGES TO THE SMALL CRAFT ADVISORY BUT DID UPGRADE THE OPEN WATER GALE WATCH TO A WARNING. MAY SEE WINDS DIMINISH TO BELOW GALES FASTER THAN THE WARNING WOULD INDICATE...BUT HAVE LIMITED CONFIDENCE IN HOW LONG GALES WILL LAST SO LEFT THE END TIME AS IS. A TROUGH OF LOW PRESSURE MOVES OVER THE LAKE THIS AFTERNOON WITH WEST WINDS BECOMING SOUTH OVER THE NEXT FEW HOURS. WINDS RETURN TO WEST BEHIND THE TROUGH THIS AFTERNOON AND INCREASE TO GALES BY THE LATE AFTERNOON. GALES CONTINUE OVERNIGHT INTO THURSDAY MORNING...BUT THEY MAY COME DOWN BELOW GALE FORCE SOONER THAN THE WARNING INDICATES. NW WINDS TO 30 KT BECOME WEST 10-20 KT BY FRIDAY MORNING. HIGH PRESSURE PASSES SOUTH OF THE LAKE LATE THURSDAY NIGHT AND FRIDAY MORNING WITH LIGHT WINDS BECOMING SOUTH TO SOUTHWEST TO 20 KT BY FRIDAY EVENING. WINDS INCREASE TO 30 KT FRIDAY NIGHT AS THE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A LOW OVER NORTHERN QUEBEC. SOUTH WINDS PERSIST THROUGH SATURDAY NIGHT BEFORE BECOMING SOUTHEAST SUNDAY AHEAD OF THE NEXT LOW. GUIDANCE DIFFERS ON STRONG THE LOW WILL BE AND ITS EXACT PATH BUT GUIDANCE MEMBERS DO AGREE THAT THE LAKE WILL MOVE OVER THE LAKE AT SOME POINT SUNDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM WEDNESDAY TO 9 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
422 AM MST WED NOV 19 2014 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 218 AM MST WED NOV 19 2014 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS INDICATE LARGE SCALE TROUGHING ACROSS THE EASTERN UNITED STATES WITH AN AMPLIFIED RIDGE UPSTREAM ACROSS THE PACIFIC US COAST. BETWEEN THESE FEATURES NORTH-NORTHWEST FLOW IS IN PLACE FROM THE NORTHERN PLAINS TO SOUTHERN PLAINS. AT THE THE SURFACE ARCTIC COLD FRONT IS APPROXIMATELY ALONG THE SD/NE STATE LINE WITH A SURFACE LOW OVER NORTHCENTRAL COLORADO. SURFACE HIGH PRESSURE IS CURRENTLY IN PLACE OVER OUR CWA. UPPER LEVEL STORM TRACK IS SPLIT AROUND OUR CWA THROUGH THE END OF THE WEEK SO FORECAST CONDITIONS SHOULD REMAIN DRY DURING THESE PERIODS. AS OF 00Z GUIDANCE...NAM SNOW DEPTH CONTINUED TO BE UNREFLECTIVE OF CURRENT SNOW FIELD AND HOLDS THIS SNOW FIELD IN PLACE THROUGH THIS WEEKEND. AS A RESULT BL CONDITIONS AND SURFACE TEMPS FROM THE NAM WERE NOT USED IN CURRENT FORECAST...THOUGH LARGER SCALE FIELDS WERE TAKEN INTO CONSIDERATION. RAP/HRRR SNOW FIELDS WERE MORE REFLECTIVE OF REALITY...SO THESE MODELS WERE USED THROUGH THE NEXT 24 HR FOR ADJUSTING SHORT RANGE BL TRENDS. TODAY-TONIGHT...ARCTIC FRONT MOVES FROM NORTHERN PLAINS TOWARDS CENTRAL MISSISSIPPI RIVER VALLEY BY MIDDAY TODAY. WHILE COLDEST AIR MASS REMAINS NORTH AND EAST...THIS FRONT WILL LEAD TO A DECREASE IN TEMPS ALOFT OVER OUR CWA. LEE TROUGH REDEVELOPING THIS AFTERNOON WILL HELP BRING RETURN FLOW INTO MOST OF OUR CWA...SO WE SHOULD MANAGE TO WARM TO SEASONAL NORMALS IN THE UPPER 40S TO AROUND 50 FOR MOST LOCATIONS. THURSDAY-FRIDAY NIGHT...SHORTWAVE RIDGE QUICKLY SHIFTS EAST WITH SHORTWAVE TROUGHS SPLITTING AROUND OUR CWA DURING THESE PERIODS. AS THIS PATTERN EVOLVES TEMPS ALOFT WILL GENERALLY SUPPORT SEASONAL HIGHS IN THE UPPER 40S/LOWER 50S. AS THE SOUTHERN STREAM UPPER LOW AND SURFACE LOW TRANSITION ACROSS THE SOUTHERN PLAINS...EASTERLY TO SOUTHEAST FLOW WILL BRING INCREASING LOW LEVEL MOISTURE ACROSS WESTERN KS/SW NEBRASKA. GFS/SREF ARE SHOWING A SHALLOW SATURATED LAYER DEVELOPING THURSDAY NIGHT. THERE IS WEAK LIFT WITHIN THIS LAYER...HOWEVER DUE TO THE LIMITED DEPTH OF THIS LAYER CONFIDENCE IS HIGHER IN A FREEZING FOG/STRATUS EVENT RATHER THAN FREEZING DRIZZLE THURSDAY NIGHT/FRIDAY MORNING. I COULDNT RULE OUT A FEW POCKETS OF FREEZING DRIZZLE THOUGH. AS LEE TROUGH REDEVELOPS FRIDAY...DRY AIR ADVECTING IN FROM THE WEST SHOULD HELP ERODE ANY FOG/STRATUS. I AM CONCERNED THAT STRATUS MAY HOLD ON IN OUR EAST AND LIMIT DIURNAL WARMING...BUT AT THIS POINT I DONT HAVE ENOUGH CONFIDENCE TO UNDERCUT CONSENSUS IN OUR EAST BY MORE THAN A FEW DEGREES. GFS STILL SHOWS LOW LEVEL MOISTURE POOLING ACROSS OUR EAST FRIDAY NIGHT IN OUR FAR EASTERN CWA...SO FREEZING FOG MAY REDEVELOP. ANY FOG SHOULD BE QUICKLY TRENDING EAST WITH WEST/SOUTHWEST FLOW MOVING EAST THROUGH FRIDAY NIGHT. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 218 AM MST WED NOV 19 2014 SATURDAY...LOTS OF SUN DURING TIME OF PEAK HEATING BUT AN INCREASE IN MID AND HIGH CLOUDS MOVES INTO FAR EASTERN COLORADO TOWARD THE END OF THE DAY. THESE CLOUDS THEN TRAVERSE THE REST OF THE FORECAST AREA SATURDAY NIGHT. THERE IS SOME WEAK MID LEVEL FORCING WITH THE MOSTLY MID LEVEL CLOUDINESS WHICH COULD PRODUCE A FEW AREAS OF VIRGA BUT WITH RATHER LIMITED MOISTURE IN THE LOWER ATMOSPHERE PRECIPITATION CHANCES ARE PRETTY LOW. SOMETHING TO WATCH. BEHIND THE WAVE THAT MOVES THROUGH SATURDAY NIGHT WILL BE A COLD FRONT AND NORTHWEST WINDS INCREASING INTO THE 15 TO 20 MPH RANGE WITH SOME HIGHER GUSTS FOR MOST OF THE AREA. GFS/ECMWF 850MB TEMPERATURES SUPPORT HIGH TEMPERATURES PRODUCED BY MEX GUIDANCE (UPPER 50S AND LOW 60S) VS THE EXTENDED PROCEDURE WHICH IS PRODUCING LOW TO MID 50S. PER COORDINATION WITH NORTHERN AND EASTERN AND SOUTHERN OFFICES HAVE RAISED TEMPS ABOUT 3-4F AS A START. LOWS IN THE MID 20S TO AROUND 30. SUNDAY...UPPER TROUGH AXIS AND PLENTIFUL CLOUDINESS PASS ACROSS THE AREA DURING THE DAY LEAVING THE AREA UNDER NORTHWEST FLOW AND DECREASING CLOUDINESS OVERNIGHT. IT WILL BE WINDY DURING THE DAY WITH NORTHWEST WINDS AROUND 20 MPH WITH HIGHER GUSTS. DURING THE NIGHT 10 TO 20 MPH. GFS/ECMWF 850MB TEMPERATURES SUPPORT ADVERTISED HIGHS IN THE LOW TO MID 40S IN FAR EASTERN COLORADO...UPPER 40S TO LOW 50S EAST OF THE STATE LINE. LOWS SUNDAY NIGHT IN THE UPPER TEENS IN FAR EASTERN COLORADO TO THE MID 20S IN THE HILL CITY AREA. DESPITE INCREASING MOISTURE IN THE MID AND UPPER LEVELS FINER DETAILS AS TO WHERE IT WILL BE AND TIMING OF THE TROUGH PASSAGE PRECLUDE A PRECIPITATION MENTION AT PRESENT TIME. MONDAY...GFS/ECMWF HAVING A HARDER TIME AGREEING ON LARGE SCALE FEATURES AND POSSIBLY MORE IMPORTANTLY LOWER LEVEL FEATURES. ONE EXAMPLE IS 850MB TEMPERATURES. GFS ABOUT 6-7C WARMER THAN THE ECMWF WHICH MAKES A LARGE DIFFERENCE IN TEMPERATURE FORECAST. NO CHANGES MADE AT THIS POINT AND RAN WITH MID 30S TO LOW 40S IN FAR EASTERN COLORADO WITH LOW 40S EAST OF THE BORDER. VARIABLE CLOUDINESS THROUGH THE PERIOD WITH DRY CONDITIONS EXPECTED. LOWS MONDAY NIGHT TEENS TO LOW 20S. CURRENTLY LOOKING AT WINDY CONDITIONS FROM THE NORTHWEST DURING THE DAY. TUESDAY...MAY SEE MORE CLOUDINESS THEN CURRENTLY ADVERTISED AND ONCE AGAIN ITS CONFINED TO MID AND UPPER LEVELS WHICH ISNT FAVORABLE FOR PRECIPITATION. NO CHANGES TO TEMPERATURE FORECAST WITH HIGHS IN THE LOW TO MID 40S AND LOWS IN THE MID 20S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 422 AM MST WED NOV 19 2014 VFR CONDITIONS SHOULD PREVAIL AT BOTH KGLD AND KMCK. 12-18 KFT AGL CLOUDS WILL CONTINUE TO STREAM FROM THE NORTHWEST TO SOUTHEAST ACROSS THE REGION. HIGH PRESSURE WILL BUILD OVER BOTH TERMINALS AS A COLD FRONT MOVES SOUTH TODAY. NW WINDS AROUND 10 KT WILL LIKELY DECREASE AS SURFACE GRADIENT WEAKENS...BECOMING LIGHT AND VARIABLE AROUND 00Z THROUGH THE REST OF THE TAF PERIOD. 06Z NAM CONTINUES TO SHOW LOW LEVEL MOISTURE POOLING OVER SW NEBRASKA LATE TONIGHT...HOWEVER ALL OTHER SHORT RANGE GUIDANCE KEEPS BETTER BL MOISTURE WELL NORTH OF KMCK. THOUGH UPDATED SNOW FIELD APPEARS TO BE IN BETTER ALIGNMENT THAN 00Z...I STILL DO NOT HAVE A LOT OF CONFIDENCE IN THE NAM SOLUTION AT THIS POINT CONSIDERING OTHER GUIDANCE IS FAVORING VFR. I HAVE LEFT ANY MENTION OF SUB VFR CONDITIONS OUT OF KMCK TAF DURING THIS UPDATE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...DR
AREA FORECAST DISCUSSION
NWS JACKSON KY
ISSUED BY NATIONAL WEATHER SERVICE CHARLESTON WV 941 AM EST WED NOV 19 2014 .UPDATE... ISSUED AT 940 AM EST WED NOV 19 2014 SFC HIGH CENTERED OVER THE SOUTHEASTERN US...WITH SFC LOW OVER THE GREAT LAKES PLACING EASTERN KY UNDER SOUTH TO SOUTHWESTERLY GRADIENT FLOW TODAY. IR SAT IMAGERY SHOWING MID TO HI CLOUDS ERODING OVER CENTRAL KY THIS MORNING AS THEY APPROACH THE DRY ATMOSPHERIC COLUMN IN PLACE INVOF OF NORTHERN PERIPHERY OF HIGH TO OUR SOUTH. CLOUDS SHOULD GRADUALLY START TO WORK THEIR WAY INTO WESTERN PORTIONS OF THE CWA THIS AFTERNOON. NO MAJOR UPDATES PLANNED AS CURRENT TRENDS COVERED. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 345 AM EST WED NOV 19 2014 07Z SFC ANALYSIS SHOWS HIGH PRESSURE OVER EASTERN KENTUCKY. THE CLEAR SKIES IN PLACE...LIGHT WINDS...AND LOW DEWPOINTS ARE MAKING A RECORD SETTING COLD NIGHT EVEN COLDER FOR THE VALLEYS THROUGH THE AREA DUE TO AN INVERSION AND RADIATIONAL COOLING. CURRENTLY READINGS ARE VARYING FROM NEAR 10 DEGREES IN THE DEEPER VALLEYS TO THE MID AND UPPER TEENS ON THE RIDGES. DEWPOINTS...MEANWHILE...ARE RUNNING IN THE SINGLE DIGITS. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT A DEEP TROUGH GENERALLY ON THE WANE OVER THE OHIO VALLEY BUT WITH A SLIGHT RESURGENCE TAKING PLACE INTO THURSDAY MORNING DUE TO A SHARP SHORTWAVE CROSSING THE GREAT LAKES. THIS PROCESS LURES A WEAK ENERGY STREAM NORTH INTO KENTUCKY DURING THE DAY THURSDAY AS THE LARGER TROUGH STARTS TO MOVE OFF TO THE NORTHEAST. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR MODELS FOR THE WX DETAILS. SENSIBLE WEATHER WILL FEATURE A VERY COLD START TO THE DAY WITH READINGS SOME 5 DEGREES OR SO BELOW RECORD LEVELS IN MANY PLACES ACROSS EAST KENTUCKY. WITH AMPLE SUNSHINE IN THE MORNING... TEMPERATURES WILL CLIMB SMARTLY SO THAT HIGHS WILL BE AT LEAST 10 DEGREES WARMER THAN YESTERDAY THROUGHOUT THE AREA. HOWEVER...HIGH... AND LATER LOWER CLOUDS...WILL BE ON THE INCREASE DURING THE AFTERNOON FROM THE NORTHWEST AHEAD OF AN APPROACHING CLIPPER SYSTEM AND ITS TRAILING COLD FRONT. THIS FRONT WILL PRESS INTO THE AREA WITH A POCKET OF LOW LEVEL MOISTURE CAPABLE OF GENERATING LIGHT PCPN WHEN COMBINED WITH THE SMALL LIFT ACCOMPANYING THE FRONT. THE QUESTION BECOMES P-TYPE GIVEN THE COLD TEMPERATURES ALOFT AND DEPTH OF...OR LACK THEREOF...MOISTURE. IT DOES LOOK LIKE THERE WILL BE JUST ENOUGH MOISTURE AT THE COLDER TEMPERATURES TO GENERATE ICE CRYSTALS FOR SNOW AND SO THAT WAS THE MAIN WX FORECAST FOR TONIGHT. HOWEVER...SHOULD THIS NOT OCCUR...POCKETS OF FREEZING DRIZZLE WILL BE POSSIBLE. NEVERTHELESS...ONLY A HUNDREDTH OR TWO OF LIQUID EQUIVALENT IS EXPECTED FROM THIS FRONT SO IT IS A MARGINAL CONCERN...BUT ONE WORTH NOTING. LOW CLOUDS WILL THEN LINGER OVER THE AREA THROUGH THE REST OF THE DAY THURSDAY WITH LITTLE PUSH TO CLEAR THEM OUT...HINDERING OUR TEMPERATURE RECOVERY. USED THE BCCONSSHORT GUIDANCE FOR THE STARTING POINT OF THE T/TD AND WIND GRIDS THROUGH THE FIRST PART OF TONIGHT AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS FOR THE TERRAIN DIFFERENCES THROUGHOUT THE PERIOD. AS FOR POPS...ENDED UP HIGHER THAN ALL THE GUIDANCE TONIGHT...IN THE SCATTERED RANGE OF THE WX COVERAGE TERM. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 409 AM EST WED NOV 19 2014 A STRONG UPPER LEVEL TROUGH ACROSS MUCH OF THE NE CONUS WILL CONTINUE TO SHIFT EASTWARD AS WE HEAD INTO THURSDAY NIGHT. AS A RESULT...MUCH OF THE OHIO RIVER VALLEY REGION CAN EXPECT INCREASING HEIGHTS AND SURFACE HIGH PRESSURE TO BE MOVING IN. WITH BOTH DRY AIR IN THE MID AND UPPER LEVELS...THIS WILL PRODUCE STRONG RADIATIONAL COOLING AND ALLOW TEMPERATURES TO DROP BACK DOWN INTO THE UPPER TEENS AND LOW 20S ONCE MORE. LUCKILY...WINDS NEAR THE SURFACE WILL BE FAIRLY LIGHT...SO DON/T EXPECT THE WIND CHILL FACTOR TO BE MORE THAN A FEW DEGREES COOLER. WHAT IS OF CONCERN...HOWEVER...IS THE LOW LEVEL MOISTURE THAT COULD BE LINGERING FROM THE PREVIOUS DAY. ACCORDING TO THE LATEST FORECAST SOUNDINGS...A STRONG SUBSIDENCE INVERSION SETS UP THURSDAY NIGHT...TRAPPING A LAYER OF LOW LEVEL MOISTURE NEAR THE SURFACE. GIVEN THE EXPECTED TEMPERATURES...IF ANY FOG DEVELOPS FROM THIS...COULD BE LOOKING AT A FREEZING FOG EVENT. HIGH PRESSURE SHOULD HOLD ON THROUGH FRIDAY NIGHT...WITH HEIGHTS ALOFT CONTINUING TO INCREASE. THIS WILL ALLOW TEMPS TO RISE INTO THE UPPER 30S AND LOW 40S ON FRIDAY AFTERNOON...AND THEN INTO THE 50S AS WE HIT SATURDAY AFTERNOON. THERE WILL BE A DISTURBANCE WHICH IS POSED TO MOVE INTO THE AREA DURING THE WEEKEND. AS A RESULT...EXPECT CLOUD COVER TO SPREAD ACROSS EASTERN KY AHEAD OF THE SYSTEM THROUGHOUT FRIDAY NIGHT. THE LOW LEVELS LOOK TO BE QUITE DRY...WITH A WARM NOSE ABOVE FREEZING JUST ABOVE THE SURFACE. AS A RESULT...DO NOT EXPECT ANY FURTHER CONCERNS FOR FOG OR FREEZING PRECIP DURING THIS TIME PERIOD...BUT IF ANY PRECIP DOES MAKE IT INTO OUR WESTERN FRINGE COUNTIES BY 12Z SATURDAY...COULD SEE SOME SLIGHT CHANCES FOR FREEZING RAIN. DAYS 4 THROUGH 7... MODELS ARE IN FAIRLY GOOD AGREEMENT WITH UL PATTERN THROUGH THIS PERIOD. UL RIDGING GRADUALLY SHIFTS EWRD OVER THE ATLANTIC AS A BROAD UL TROF MOVES OVER THE EASTERN CONUS ON MONDAY. THE UL TROF WILL BE THE DOMINATE WX PATTERN FROM MONDAY THROUGH THE END OF THE PERIOD. AT LOWER LEVELS... LL MOISTURE INCREASES SATURDAY AHEAD OF THE NEXT SYSTEM THAT WILL EJECT OUT OF THE SOUTHERN PLAINS. THIS SYSTEM IS FORECASTED TO QUICKLY MOVE NEWD ACROSS THE CWA SUNDAY AFTERNOON. SINCE IT IS QUICK MOVING...THE MAIN BATCH OF PRECIP IS FORECASTED TO AFFECT THE AREA SUNDAY AFTERNOON AND EVENING. IN TERMS OF THE GRIDS...HAVE SLOWED DOWN THE ONSET OF THE PRECIP FROM PREVIOUS FORECAST SINCE THE GFS/ECMWF KEPT PRECIP OUT OF THE CWA UNTIL 12Z SUNDAY. AS THE SYSTEM LIFTS NEWD...THERE MAY BE SOME ADDITIONAL PRECIP ASSOCIATED WITH THE SFC LOW...AND ADDITIONAL S/WV ENERGY MOVING THROUGH THE BASE OF THE TROF. DEPENDING ON THE LOWS TRACK AND HOW IT PHASES WITH THE NORTHERN STREAM ENERGY...CLOUDS AND A CHANCE FOR PRECIP COULD LINGER THROUGH TUESDAY MORNING. BOTH THE GFS AND ECMWF DIFFER IN REGARDS TO THE PHASING OF THE NORTHERN AND SOUTHERN STREAM ENERGY...SO HAVE KEPT CHANCES FOR RAIN IN THE GRIDS THROUGH MONDAY EVENING. TUESDAY AND WEDNESDAY APPEAR TO BE MOSTLY QUIET AS THE SFC TROF SLOWLY MOVES OUT AND HIGH PRESSURE BUILDS INTO THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 705 AM EST WED NOV 19 2014 THE TAF SITES WILL EXPERIENCE VFR CONDITIONS FOR THE BULK OF THE PERIOD. HOWEVER CLOUD COVER WILL DEVELOP AND THICKEN THROUGH THE AFTERNOON FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA AS A CLIPPER SYSTEM EJECTS OUT OF THE NORTHERN PLAINS AND MOVES ACROSS THE LOWER GREAT LAKES REGION. AFTER 00Z A FEW SNOW SHOWERS WILL BE POSSIBLE FROM THIS SYSTEM...VCSH IS IN THE TAFS FOR THIS...AS CIGS DROP INTO THE MVFR RANGE WITH IFR POSSIBLE BEFORE DAWN THURSDAY. WINDS WILL PICK UP FROM THE SOUTH TO SOUTHWEST TODAY WITH INCREASING STRENGTH AFTER 15Z TO AROUND 10 KTS SUSTAINED...GUSTING TO 20 KTS DURING THE AFTERNOON. THE WINDS WILL SETTLE A BIT LATER TONIGHT AS THEY START TO TURN TO MORE TOWARD THE WEST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KMC SHORT TERM...GREIF LONG TERM...JMW/JVM AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
705 AM EST WED NOV 19 2014 .UPDATE... ISSUED AT 650 AM EST WED NOV 19 2014 DID AN UPDATE TO THE GRIDS TO FINE TUNE THE SKY COVER...T...AND TD ONES WITH THE LATEST OBS AND TRENDS. THIS CAPTURES THE SINGLE DIGITS IN SOME OF THE VALLEYS CURRENTLY AS WELL AS THE MILDER RIDGES AND SPOTS WEST OF I-75. HAVE SENT THESE TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 345 AM EST WED NOV 19 2014 07Z SFC ANALYSIS SHOWS HIGH PRESSURE OVER EASTERN KENTUCKY. THE CLEAR SKIES IN PLACE...LIGHT WINDS...AND LOW DEWPOINTS ARE MAKING A RECORD SETTING COLD NIGHT EVEN COLDER FOR THE VALLEYS THROUGH THE AREA DUE TO AN INVERSION AND RADIATIONAL COOLING. CURRENTLY READINGS ARE VARYING FROM NEAR 10 DEGREES IN THE DEEPER VALLEYS TO THE MID AND UPPER TEENS ON THE RIDGES. DEWPOINTS...MEANWHILE...ARE RUNNING IN THE SINGLE DIGITS. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT A DEEP TROUGH GENERALLY ON THE WANE OVER THE OHIO VALLEY BUT WITH A SLIGHT RESURGENCE TAKING PLACE INTO THURSDAY MORNING DUE TO A SHARP SHORTWAVE CROSSING THE GREAT LAKES. THIS PROCESS LURES A WEAK ENERGY STREAM NORTH INTO KENTUCKY DURING THE DAY THURSDAY AS THE LARGER TROUGH STARTS TO MOVE OFF TO THE NORTHEAST. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR MODELS FOR THE WX DETAILS. SENSIBLE WEATHER WILL FEATURE A VERY COLD START TO THE DAY WITH READINGS SOME 5 DEGREES OR SO BELOW RECORD LEVELS IN MANY PLACES ACROSS EAST KENTUCKY. WITH AMPLE SUNSHINE IN THE MORNING... TEMPERATURES WILL CLIMB SMARTLY SO THAT HIGHS WILL BE AT LEAST 10 DEGREES WARMER THAN YESTERDAY THROUGHOUT THE AREA. HOWEVER...HIGH... AND LATER LOWER CLOUDS...WILL BE ON THE INCREASE DURING THE AFTERNOON FROM THE NORTHWEST AHEAD OF AN APPROACHING CLIPPER SYSTEM AND ITS TRAILING COLD FRONT. THIS FRONT WILL PRESS INTO THE AREA WITH A POCKET OF LOW LEVEL MOISTURE CAPABLE OF GENERATING LIGHT PCPN WHEN COMBINED WITH THE SMALL LIFT ACCOMPANYING THE FRONT. THE QUESTION BECOMES P-TYPE GIVEN THE COLD TEMPERATURES ALOFT AND DEPTH OF...OR LACK THEREOF...MOISTURE. IT DOES LOOK LIKE THERE WILL BE JUST ENOUGH MOISTURE AT THE COLDER TEMPERATURES TO GENERATE ICE CRYSTALS FOR SNOW AND SO THAT WAS THE MAIN WX FORECAST FOR TONIGHT. HOWEVER...SHOULD THIS NOT OCCUR...POCKETS OF FREEZING DRIZZLE WILL BE POSSIBLE. NEVERTHELESS...ONLY A HUNDREDTH OR TWO OF LIQUID EQUIVALENT IS EXPECTED FROM THIS FRONT SO IT IS A MARGINAL CONCERN...BUT ONE WORTH NOTING. LOW CLOUDS WILL THEN LINGER OVER THE AREA THROUGH THE REST OF THE DAY THURSDAY WITH LITTLE PUSH TO CLEAR THEM OUT...HINDERING OUR TEMPERATURE RECOVERY. USED THE BCCONSSHORT GUIDANCE FOR THE STARTING POINT OF THE T/TD AND WIND GRIDS THROUGH THE FIRST PART OF TONIGHT AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS FOR THE TERRAIN DIFFERENCES THROUGHOUT THE PERIOD. AS FOR POPS...ENDED UP HIGHER THAN ALL THE GUIDANCE TONIGHT...IN THE SCATTERED RANGE OF THE WX COVERAGE TERM. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 409 AM EST WED NOV 19 2014 A STRONG UPPER LEVEL TROUGH ACROSS MUCH OF THE NE CONUS WILL CONTINUE TO SHIFT EASTWARD AS WE HEAD INTO THURSDAY NIGHT. AS A RESULT...MUCH OF THE OHIO RIVER VALLEY REGION CAN EXPECT INCREASING HEIGHTS AND SURFACE HIGH PRESSURE TO BE MOVING IN. WITH BOTH DRY AIR IN THE MID AND UPPER LEVELS...THIS WILL PRODUCE STRONG RADIATIONAL COOLING AND ALLOW TEMPERATURES TO DROP BACK DOWN INTO THE UPPER TEENS AND LOW 20S ONCE MORE. LUCKILY...WINDS NEAR THE SURFACE WILL BE FAIRLY LIGHT...SO DON/T EXPECT THE WIND CHILL FACTOR TO BE MORE THAN A FEW DEGREES COOLER. WHAT IS OF CONCERN...HOWEVER...IS THE LOW LEVEL MOISTURE THAT COULD BE LINGERING FROM THE PREVIOUS DAY. ACCORDING TO THE LATEST FORECAST SOUNDINGS...A STRONG SUBSIDENCE INVERSION SETS UP THURSDAY NIGHT...TRAPPING A LAYER OF LOW LEVEL MOISTURE NEAR THE SURFACE. GIVEN THE EXPECTED TEMPERATURES...IF ANY FOG DEVELOPS FROM THIS...COULD BE LOOKING AT A FREEZING FOG EVENT. HIGH PRESSURE SHOULD HOLD ON THROUGH FRIDAY NIGHT...WITH HEIGHTS ALOFT CONTINUING TO INCREASE. THIS WILL ALLOW TEMPS TO RISE INTO THE UPPER 30S AND LOW 40S ON FRIDAY AFTERNOON...AND THEN INTO THE 50S AS WE HIT SATURDAY AFTERNOON. THERE WILL BE A DISTURBANCE WHICH IS POSED TO MOVE INTO THE AREA DURING THE WEEKEND. AS A RESULT...EXPECT CLOUD COVER TO SPREAD ACROSS EASTERN KY AHEAD OF THE SYSTEM THROUGHOUT FRIDAY NIGHT. THE LOW LEVELS LOOK TO BE QUITE DRY...WITH A WARM NOSE ABOVE FREEZING JUST ABOVE THE SURFACE. AS A RESULT...DO NOT EXPECT ANY FURTHER CONCERNS FOR FOG OR FREEZING PRECIP DURING THIS TIME PERIOD...BUT IF ANY PRECIP DOES MAKE IT INTO OUR WESTERN FRINGE COUNTIES BY 12Z SATURDAY...COULD SEE SOME SLIGHT CHANCES FOR FREEZING RAIN. DAYS 4 THROUGH 7... MODELS ARE IN FAIRLY GOOD AGREEMENT WITH UL PATTERN THROUGH THIS PERIOD. UL RIDGING GRADUALLY SHIFTS EWRD OVER THE ATLANTIC AS A BROAD UL TROF MOVES OVER THE EASTERN CONUS ON MONDAY. THE UL TROF WILL BE THE DOMINATE WX PATTERN FROM MONDAY THROUGH THE END OF THE PERIOD. AT LOWER LEVELS... LL MOISTURE INCREASES SATURDAY AHEAD OF THE NEXT SYSTEM THAT WILL EJECT OUT OF THE SOUTHERN PLAINS. THIS SYSTEM IS FORECASTED TO QUICKLY MOVE NEWD ACROSS THE CWA SUNDAY AFTERNOON. SINCE IT IS QUICK MOVING...THE MAIN BATCH OF PRECIP IS FORECASTED TO AFFECT THE AREA SUNDAY AFTERNOON AND EVENING. IN TERMS OF THE GRIDS...HAVE SLOWED DOWN THE ONSET OF THE PRECIP FROM PREVIOUS FORECAST SINCE THE GFS/ECMWF KEPT PRECIP OUT OF THE CWA UNTIL 12Z SUNDAY. AS THE SYSTEM LIFTS NEWD...THERE MAY BE SOME ADDITIONAL PRECIP ASSOCIATED WITH THE SFC LOW...AND ADDITIONAL S/WV ENERGY MOVING THROUGH THE BASE OF THE TROF. DEPENDING ON THE LOWS TRACK AND HOW IT PHASES WITH THE NORTHERN STREAM ENERGY...CLOUDS AND A CHANCE FOR PRECIP COULD LINGER THROUGH TUESDAY MORNING. BOTH THE GFS AND ECMWF DIFFER IN REGARDS TO THE PHASING OF THE NORTHERN AND SOUTHERN STREAM ENERGY...SO HAVE KEPT CHANCES FOR RAIN IN THE GRIDS THROUGH MONDAY EVENING. TUESDAY AND WEDNESDAY APPEAR TO BE MOSTLY QUIET AS THE SFC TROF SLOWLY MOVES OUT AND HIGH PRESSURE BUILDS INTO THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 705 AM EST WED NOV 19 2014 THE TAF SITES WILL EXPERIENCE VFR CONDITIONS FOR THE BULK OF THE PERIOD. HOWEVER CLOUD COVER WILL DEVELOP AND THICKEN THROUGH THE AFTERNOON FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA AS A CLIPPER SYSTEM EJECTS OUT OF THE NORTHERN PLAINS AND MOVES ACROSS THE LOWER GREAT LAKES REGION. AFTER 00Z A FEW SNOW SHOWERS WILL BE POSSIBLE FROM THIS SYSTEM...VCSH IS IN THE TAFS FOR THIS...AS CIGS DROP INTO THE MVFR RANGE WITH IFR POSSIBLE BEFORE DAWN THURSDAY. WINDS WILL PICK UP FROM THE SOUTH TO SOUTHWEST TODAY WITH INCREASING STRENGTH AFTER 15Z TO AROUND 10 KTS SUSTAINED...GUSTING TO 20 KTS DURING THE AFTERNOON. THE WINDS WILL SETTLE A BIT LATER TONIGHT AS THEY START TO TURN TO MORE TOWARD THE WEST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...JMW/JVM AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
624 AM EST WED NOV 19 2014 .SYNOPSIS... ISSUED AT 340 AM EST WED NOV 19 2014 LOW PRESSURE PASSING ACROSS THE NORTHERN LAKES WILL BRING ANOTHER ROUND OF LAKE EFFECT SNOW...AT TIMES HEAVY...THROUGH THURSDAY. TEMPERATURES WILL TURN MILDER DURING THE UPCOMING WEEKEND... SETTING THE STAGE FOR SOME RAIN...ESPECIALLY BY SUNDAY AND SUNDAY NIGHT. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 340 AM EST WED NOV 19 2014 ...MORE SIGNIFICANT LAKE EFFECT SNOW ON THE WAY... HIGH IMPACT WEATHER POTENTIAL: WIDESPREAD MOSTLY LIGHT SYNOPTIC SNOW TODAY WITH LAKE ENHANCEMENT NEAR LAKE MICHIGAN...THEN ANOTHER ROUND OF SIGNIFICANT LAKE EFFECT SNOWFALL DEVELOPING TONIGHT. PATTERN SYNOPSIS/FORECAST: UPSTREAM SHORTWAVE TROUGH OVER THE UPPER MISSISSIPPI VALLEY DRIVING A BAND OF WARM AIR ADVECTION SNOW ACROSS THE UPPER MIDWEST. THIS SHORTWAVE FEATURE WILL SERVE TO RE-INFORCE LONGWAVE TROUGH OVER THE EASTERN CONUS AND USHER IN ANOTHER SURGE OF EARLY SEASON ARCTIC AIR WITH LAKE EFFECT SNOW. PRIMARY FORECAST CONCERNS: NUMEROUS. LAKE ENHANCED SNOW ACCUMULATIONS TODAY NEAR THE LAKE MICHIGAN COAST. THEN QUICK TRANSITION TO WEST-NORTHWEST LAKE EFFECT TONIGHT WITH SIGNIFICANT ACCUMULATIONS POSSIBLE. IN ADDITION...GUSTY WINDS MAY CREATE LOW VISIBILITIES AND TRAVEL PROBLEMS WITHIN HEAVIER SNOWSHOWERS. AFOREMENTIONED WARM ADVECTION LIGHT SNOW WILL DEVELOP ACROSS NORTHERN MICHIGAN TODAY WITH BROAD AREA OF ISENTROPIC ASCENT. THIS IS THE EASIEST PORTION OF THE FORECAST...AS ALL AREAS SHOULD SEE AT LEAST SOME SNOW TODAY. H7 MIXING RATIO/S ONLY AROUND 1 G/KG...SO ONLY LIGHT ACCUMULATIONS ON THE ORDER OF 1-2 INCHES. THE EXCEPTION TO THE LIGHTER SNOWS WILL BE CLOSER TO LAKE MICHIGAN...WHERE INCREASING SYNOPTIC FORCING COMBINED WITH PLENTY OF OVER-LAKE INSTABILITY /DELTA T/S IN THE MID-UPPER TEENS/ WILL RESULT IN ENHANCED SNOWFALL. SOME QUESTION MARKS AS TO HOW THE LOW LEVEL FLOW WILL EVOLVE WITH SURFACE LOW OVER NORTHERN LAKE MICHIGAN. WILL LEAN TOWARD HIGH RESOLUTION HRRR FOR LOW LEVEL PATTERN EVOLUTION INTO EARLY THIS AFTERNOON. IMPRESSIVE LOW LEVEL CONVERGENCE SIGNATURE WITH 0-2KM CAPE OF 100 J/KG UP THE SPINE OF LAKE MICHIGAN THIS MORNING WILL BE DRIVEN INLAND TOWARD MANISTEE/BENZIE/LEELANAU COUNTIES AS COLD FRONT SLIDES EAST AND LOW LEVEL FLOW TURNS MORE WESTERLY. OVER WESTERN MACKINAC COUNTY...INITIALLY LOW LEVEL SOUTHWEST FLOW WILL BACK SOUTHEASTERLY THIS MORNING AS WEAK SURFACE LOW MOVES INTO NORTHERN LAKE MICHIGAN. THIS WILL SET UP AN ENHANCED LOW LEVEL CONVERGENCE BAND OF HEAVIER SNOWFALL JUST OFFSHORE OF MACKINAC COUNTY THIS MORNING WHICH WILL BE DRIVEN TOWARD US-2 THIS AFTERNOON WITH NORTHEAST PROGRESSION OF SURFACE LOW. EXPECT LAKE ENHANCED BAND OF HEAVIER SNOW WEST OF THE US-131 CORRIDOR LATE THIS AFTERNOON/EARLY EVENING TO PUSH INLAND THIS EVENING WITH THE FRONT...GRADUALLY WEAKENING AS IT LOSES THE LAKE INFLUENCE. LOW LEVEL FLOW TRANSITIONS RAPIDLY TO WESTERLY BY LATER THIS EVENING AND BUFKIT SOUNDINGS SHOW A QUICK RAMP UP TO THE LAKE EFFECT SNOW MACHINE. THE LAKE EFFECT PARAMETERS REALLY LOOK QUITE SIMILAR TO THE BIG LAKE EFFECT EVENT MONDAY NIGHT/TUESDAY OVER PARTS OF THE AREA AND EXPECT MANY OF THE SAME AREAS TO BE HIT AGAIN WITH SOME SIGNIFICANT LAKE EFFECT ACCUMULATIONS. FORECAST SOUNDINGS SHOW DEEP MOISTURE UP THROUGH H7 AND NO REAL INVERSION...WITH EXCELLENT OMEGA PEGGED SQUARELY IN THE DGZ WITH DELTA T/S OF 20+ DEGC. SNOW WILL BE OF THE DRY/POWDERY VARIETY AND WITH SOME GUSTY WINDS...WILL ONCE AGAIN BE DEALING WITH BLOWING/DRIFTING AND AREAS OF VERY LOW VISIBILITIES. HEADLINES...CHALLENGING TO SAY THE LEAST. LAKE ENHANCED EVENT TODAY WILL BE HANDLED WITH WINTER WEATHER ADVISORIES. WILL ONLY CARRY THE ADVISORY THROUGH THIS EVENING FOR MACKINAC COUNTY...WHERE TRANSITION TO WEST FLOW LAKE EFFECT SHOULD DIMINISH THEIR SNOWFALL. WILL RUN THE ADVISORY FOR MANISTEE/BENZIE/LEELANAU COUNTIES THROUGH 12Z THURSDAY...WILL FULL EXPECTATION THAT THESE HEADLINES WILL BE EXTENDED IN TIME/AREA FOR THURSDAY-THURSDAY NIGHT TO ACCOUNT FOR ONGOING LAKE EFFECT. WITH REGARD TO THE WEST-NORTHWEST FLOW LAKE EFFECT EVENT LATER TONIGHT THROUGH THURSDAY NIGHT...WILL HOIST A LAKE EFFECT SNOW WATCH. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 340 AM EST WED NOV 19 2014 ...ANOTHER SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED THURSDAY... HIGH IMPACT WEATHER POTENTIAL: ANOTHER ROUND OF POTENTIALLY HEAVY LAKE EFFECT SNOW THURSDAY. AREAS OF BLOWING SNOW AND HAZARDOUS DRIVING CONDITIONS EXPECTED. PATTERN SYNOPSIS/CURRENT CONDITIONS: EXTREMELY AMPLIFIED PATTERN CONTINUES FOR JUST A TOUCH LONGER...WITH ONE LAST ARCTIC SHORTWAVE SET TO VISIT OUR AREA LATER TODAY THROUGH THURSDAY. PATTERN CHANGE THEREAFTER IS RATHER AN ABRUPT ONE. AN EXCEPTIONALLY STRONG AND EXTENDED PACIFIC JET EXPECTED TO PUNCH INTO THE WESTERN CONUS LATER THIS WEEK WILL DO THE TRICK. THIS FEATURE ESSENTIALLY REVERSES THE CURRENT PATTERN BY ESTABLISHING WESTERN TROUGHING AND FLOODING MUCH OF THE CONUS WITH MODIFIED PACIFIC ORIGINATED AIR BY THE WEEKEND INTO THE START OF NEXT WEEK. PRIMARY FORECAST CONCERNS/CHALLENGES: NEARLY ALL FOCUS CENTERED ON ANOTHER POTENTIALLY SIGNIFICANT LAKE EFFECT/BLOWING SNOW EVENT THURSDAY. SNOW AMOUNTS...LOCATION OF STEADIEST AND HEAVIEST LAKE BANDING...AND HEADLINE CONSIDERATION ALL NEED ADDRESSING. DETAILS: MORE LAKE EFFECT FUN! WELL ESTABLISHED PRIMARILY WNW FLOW LAKE EFFECT EXPECTED TO BE ONGOING THURSDAY MORNING...WITH FLOW EXPECTED TO VEER MORE NW TO NNW NORTH OF THE BIG BRIDGE WITH PASSAGE OF SURFACE TROUGH DURING THE MORNING. THERMODYNAMIC AND KINEMATIC PROFILES LOOK GOOD TO EXCELLENT ONCE AGAIN...WITH LAKE INDUCED EQL EXCEEDING 10KFT...OMEGA MAX WELL WITHIN THE DGZ...AND GOOD CYCLONIC FLOW/MOISTURE VIA EXITING LOW PRESSURE. OFF LAKE MICHIGAN: WHILE PARAMETERS LOOK TO FALL JUST SHORT OF THIS PAST EVENT...CONDITIONS LOOK PRIME TO PRODUCE ANOTHER 3 TO 6 INCHES...LOCALLY HIGHER...THURSDAY (THIS WILL BE ON TOP OFF WHAT OCCURS WEDNESDAY NIGHT). TARGET AREAS WILL LOOK FAMILIAR...WITH NORTHWEST LOWER LOCATIONS BETWEEN M-32 AND M-68 EXPECTED TO TAKE THE BRUNT OF THE ACTIVITY...WITH LIGHTER SNOW ELSEWHERE. FLOW DOES NOT LOOK QUITE AS STRONG AS THIS PAST SYSTEM...SUGGESTING THE HIGHEST AMOUNTS IN THE MORE TRADITIONAL AREAS ALONG AND WEST OF INTERSTATE 75. OF COURSE...PREDICTING PLACEMENT OF PARTICULAR BANDS NEXT TO IMPOSSIBLE...ALTHOUGH STREAM-LINE WIND ANALYSIS SUGGEST POTENTIAL FOR DOMINATE BANDS ALONG/JUST NORTH OF THE M-32 CORRIDOR AND JUST SOUTHEAST OF LITTLE TRAVERSE BAY. WINDS DO BEGIN TO VEER DURING THE AFTERNOON WITH APPROACH AND PASSAGE OF LAKE REINFORCED TROUGHING. WHILE WINDS WILL NOT BE EXTREME...GUSTS TO 20 TO 25 MPH WILL PRODUCE AREAS OF BLOWING/DRIFTING SNOW...WHICH WILL FURTHER CONTRIBUTE TO VERY LOW VISIBILITIES IN THE HEAVIER SNOW BANDS. DEVELOPMENT OF MORE NEUTRAL TO SLIGHTLY ANTICYCLONIC FLOW AND LOWERING INVERSION/DEPLETING MOISTURE SHOULD BRING SNOW INTENSITY DOWN RATHER RAPIDLY HEADING INTO THURSDAY NIGHT...PERHAPS BRINGING JUST A COUPLE MORE INCHES TO NW FLOW AREAS. LAKE SUPERIOR...PARAMETERS LOOK AS GOOD AS OVER LAKE MICHIGAN...JUST WITH A MUCH QUICKER VEERING OF THE WINDS WITH PASSAGE OF TROUGHING THURSDAY MORNING. WOULD EXPECT A BAND OF ENHANCED SNOW ALONG THIS FEATURE...PERHAPS TARGETING THE SOO BEFORE PUSHING WELL WEST INTO FAR NORTHWEST CHIPPEWA AND MACKINAC COUNTIES FOR LATER IN THE MORNING AND AFTERNOON. SAME SNOW ACCUMULATIONS APPLY...3 TO 6 WITH LOCALLY HIGHER AMOUNTS IN THE TRADITIONAL SNOWBELTS. AS MENTIONED...LOOKS LIKE THE BEST SNOWS WILL EXIT SAULT STE MARIE BY MIDDAY. SNOW LOOKS TO POTENTIALLY PUSH BACK INTO THE SOO THURSDAY NIGHT AS WINDS BACK MORE NORTHWESTERLY...WITH A COUPLE MORE INCHES POSSIBLE. WHILE THE MAJORITY OF TIME WAS SPENT ON THE EARLIER PERIODS...PERUSAL OF LATEST MODEL TRENDS CONTINUES TO ADD INCREASING CONFIDENCE TO A MUCH DESERVED REPRIEVE FROM THE WINTER WEATHER OF LATE...ESPECIALLY BY THE END OF THE WEEKEND INTO THE START OF NEXT WEEK. STILL LOOKING COLD FRIDAY...WITH A FEW LINGERING LIGHT LAKE INDUCED SNOW SHOWERS. MODIFICATION RAMPS UP SATURDAY AS LONG WAVE PATTERN FLATTENS SUBSTANTIALLY AND CURRENT COLD DOME EJECTS WELL TO OUR NORTHEAST. NEARLY ALL HIGH RES DETERMINISTIC AND THEIR ENSEMBLE SUITES AGREE...A RATHER REMARKABLE QUICK EXIT TO SUCH AN ENTRENCHED COLD PATTERN. WAA MAY BE ABLE TO KICK OFF A LITTLE RAIN AND SNOW SATURDAY WHEN HIGHS...READY FOR THIS...ACTUALLY REACH ABOVE FREEZING. ONLY GETS MORE MILD AND WETTER BY SUNDAY INT MONDAY AS LOW PRESSURE MOVES NORTH INTO OR JUST WEST OF OUR AREA. REALLY NO COLD AIR IN SIGHT BY THIS TIME (HIGHS PUSHING THE LOWER 40S SUNDAY AND MONDAY)...SUGGESTING ALL PRECIPITATION FALLING AS RAIN. DEPTH OF THIS SYSTEM STILL IN QUESTION...WITH SOME PROGS SUPPORTING A SUB 980MB LOW...POTENTIALLY LEADING TO SOME RATHER WINDY CONDITIONS. TIMING DEPENDENT OF COURSE...BUT POST-SYSTEM COOL DOWN BEGINS SOMETIME LATER MONDAY/MONDAY NIGHT...BRINGING A RETURN TO BELOW NORMAL TEMPERATURES AND PERHAPS SOME MORE SNOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 616 AM EST WED NOV 19 2014 LOW LEVEL WINDS WILL GRADUALLY BACK TO THE S/SW TODAY AHEAD OF AN AREA OF LOW PRESSURE LIFTING INTO THE GREAT LAKES REGION. THIS SYSTEM WILL PRODUCE WIDESPREAD LIGHT SYNOPTICALLY DRIVEN SNOW...AND WILL ENHANCE ONGOING S/SW FLOW LAKE EFFECT SNOW SHOWERS IMPACTING PORTIONS OF FAR NW LWR MICHIGAN...THE STRAITS AND MACKINAC COUNTY. WINDS WILL SHIFT TO THE WEST TONIGHT AND INCREASE WITH GUSTS OF 20-30KTS POSSIBLE. LAKE EFFECT SNOW SHOWERS WILL DEVELOP DOWNWIND OF LAKE MICHIGAN...ALONG WITH AREAS OF BLOWING SNOW. WIDESPREAD MVFR CONDITIONS THROUGH THE PERIOD WITH AREAS OF LIFR/IFR WITHIN HEAVIER SNOW SHOWER ACTIVITY. && .MARINE... ISSUED AT 340 AM EST WED NOV 19 2014 A STORM SYSTEM WILL MOVE OUT OF THE UPPER MIDWEST AND INTO THE GREAT LAKES THROUGH TONIGHT...PUSHING A COLD FRONT THROUGH THE AREA. THE GRADIENT WILL TIGHTEN WITH FROPA...WITH WINDS SHIFTING TO THE WEST. GALE FORCE GUSTS WILL BE POSSIBLE ON PORTIONS OF LAKE MICHIGAN INTO EARLY THURSDAY...WITH SMALL CRAFT ADVISORIES ELSEWHERE. ADDITIONAL SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR LAKES HURON AND SUPERIOR TONIGHT INTO THURSDAY NIGHT. WEST/NORTHWEST FLOW LAKE EFFECT SNOW WILL DEVELOP LATER TONIGHT AND CONTINUE INTO THURSDAY...RESULTING IN AREAS OF REDUCED VISIBILITIES ALONG THE COASTLINE. QUIETER WEATHER AND HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES TO END THE WEEK. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 1 AM EST THURSDAY FOR MIZ015. WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ020-025- 031. LAKE EFFECT SNOW WATCH FROM THIS EVENING THROUGH LATE THURSDAY NIGHT FOR MIZ008-016-017-019-021-022. LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LMZ323-341. GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LMZ342-344>346. LS...NONE. && $$ SYNOPSIS...MSB SHORT TERM...KEYSOR LONG TERM...MSB AVIATION...KEYSOR MARINE...KEYSOR
AREA FORECAST DISCUSSION
NWS TULSA OK
955 AM CST WED NOV 19 2014 .DISCUSSION... NW FLOW PREVAILS ALOFT OVER THE PLAINS...ON THE SOUTHWESTERN FRINGE OF A DEEP UPPER TROUGH OVER THE EASTERN CONUS. THE LOW LEVEL THERMAL RIDGE EXTENDS ACROSS OKLAHOMA THIS MORNING IN ADVANCE OF COLD FRONT OVER KANSAS MOVING SOUTH. THUS...THE WIND SHIFT AND ANY COOLING BEHIND THE BOUNDARY WILL BE TOO LITTLE AND TOO LATE TO PREVENT TEMPS FROM RISING ABOVE YESTERDAYS READINGS. IN FACT...THE COLD AIR WITH THIS FRONT SHOULD STAY TO OUR NORTHEAST AS THE UPPER TROUGH IS LIFTING OUT AS WE SPEAK. THUS...THE LATEST HRRR FORECAST HIGH FOR TODAY IS WARMER THAN YESTERDAY AND I HAVE FOLLOWED SUIT WITH THIS FORECAST UPDATE...NUDGING UP HIGHS A COUPLE DEGREES. NO OTHER NOTICEABLE CHANGES WERE MADE TO THE GOING FORECAST. LACY && .PREV DISCUSSION... /ISSUED 516 AM CST WED NOV 19 2014/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. A WEAK COLD FRONT WILL BRING A WIND SHIFT DURING THE DAY. PREV DISCUSSION... /ISSUED 301 AM CST WED NOV 19 2014/ DISCUSSION... A COLD FRONT STRETCHED ACROSS THE CENTRAL PLAINS WILL WORK ACROSS THE FORECAST AREA THIS AFTERNOON...ALTHOUGH MOST OF THE COLDER LOW-LEVEL AIR WILL REMAIN TO OUR NORTHEAST WITH NOT MUCH MORE THAN A WEAK WIND SHIFT EXPECTED. THAT SAID...FORECAST LOW-LEVEL THERMAL FIELDS SUGGESTS TEMPS A FEW DEGREES WARMER THAN YESTERDAY. THIS MODEST WARMING TREND WILL CONTINUE FOR THE REMAINDER OF THE WEEK...WITH DAYTIME TEMPS RETURNING CLOSER TO SEASONAL NORMS. 1000-850MB MOISTURE WILL INCREASE THURSDAY NIGHT INTO FRIDAY...WITH AREAS OF LIGHT RAIN AND PERHAPS SOME DRIZZLE DEVELOPING AHEAD OF A FAST MOVING UPPER WAVE. A MUCH STRONGER UPPER SYSTEM WILL MOVE FROM THE SWRN STATES FRIDAY AND INTO TX BY SATURDAY...WITH SHOWERS AND EMBEDDED THUNDERSTORMS BECOMING WIDESPREAD ACROSS MOST OF THE AREA SATURDAY MORNING AND INTO THE AFTERNOON. THE BEST CHANCES OF SEVERE WEATHER SHOULD REMAIN WELL SOUTH OF THE AREA...BUT LOCALLY HEAVY RAINFALL WILL BE POSSIBLE GENERALLY ALONG AND EAST OF I-44. PRECIPITATION WILL TAPER OFF SATURDAY NIGHT INTO SUNDAY...WITH COOLER WEATHER EXPECTED GOING INTO EARLY NEXT WEEK. OUTLOOK FOR THANKSGIVING DAY AND BEYOND REMAINS VERY MUCH IN DOUBT AS LATEST ECMWF/GFS ARE COMPLETELY OUT OF PHASE AT THE UPPER LEVELS. THE ECMWF...HOWEVER...REMAINS CONSISTENT WITH ITS PREVIOUS RUNS IN BRINGING ANOTHER SHOT OF MUCH COLDER AIR IN THE THURSDAY/FRIDAY TIMEFRAME. STAY TUNED. && .PRELIMINARY POINT TEMPS/POPS... TUL 54 29 54 40 / 0 0 0 30 FSM 55 30 55 41 / 0 0 0 40 MLC 56 31 59 47 / 0 0 0 40 BVO 52 24 53 36 / 0 0 0 20 FYV 52 23 50 38 / 0 0 0 30 BYV 52 24 50 36 / 0 0 0 30 MKO 55 28 55 42 / 0 0 0 40 MIO 49 23 51 36 / 0 0 0 30 F10 55 30 56 44 / 0 0 10 40 HHW 57 33 60 49 / 0 0 10 40 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...30
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
335 PM EST WED NOV 19 2014 .SYNOPSIS... HIGH PRESSURE SLIDES OFFSHORE TONIGHT AND IS FOLLOWED BY A COLD FRONTAL PASSAGE ON THURSDAY. BEHIND THIS FRONT, A STRONGER HIGH PRESSURE SYSTEM WILL MOVE IN FROM THE WEST ON FRIDAY, AND CREST OVER THE REGION ON SATURDAY BEFORE MOVING OFFSHORE ON SUNDAY. MEANWHILE, LOW PRESSURE WILL DEVELOP ACROSS THE INTER-MOUNTAIN WEST, AND TRACK NORTHEASTWARD TO LAKE MICHIGAN. THIS LOW WILL BRING A COLD FRONT THROUGH THE REGION EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... THE MAIN FEATURE WORKING THROUGH OUR REGION IN THIS PERIOD WILL BE A WARM FRONT COMING IN FROM THE SOUTHWEST, THE ASSOCIATED LOW PRESSURE SYSTEM WILL PASS WELL TO OUR NORTHWEST. THIS WARM FRONT WILL RESULT IN THE INCREASE OF MID AND HIGH LEVEL CLOUDS. WE CURRENTLY HAVE A VERY DRY AIRMASS IN PLACE, MARKED WITH DEWPOINTS AT OR UNDER 15 DEGREES. THIS WILL TEND TO LIMIT ANY PRECIPITATION. THE ONE EXCEPTION WOULD WITH THE AID OF TERRAIN IN THE POCONOS AND NW NJ LEADING TO SOME PATCHY FLURRIES. THE RGEM AND NAM ARE MOST AGGRESSIVE WITH THIS CHANCE. STILL OUTSIDE THE RANGE OF THE HRRR AND RAP MODELS ATTM. BOTH THE GFS AND ECMWF AGREE ON TEMPERATURES FALLING A LITTLE DUE TO RADIATIONAL COOLING DURING THE EVENING THEN RISING WITH THE WARM FRONTAL PASSAGE AROUND MIDNIGHT AND THEN FALLING SOMEWHAT TOWARD SUNRISE. TOOK THIS TREND INTO ACCOUNT BUT STAYED CLOSE TO THE MAV AND MET GOING A TOUCH COOLER IN SPOTS FAVORABLE FOR RADIATIONAL COOLING. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... SOUTHERLY FLOW WILL GIVE WAY ONCE AGAIN TO WESTERLY BEHIND THE COLD FRONT. STILL VERY DRY NO PRECIPITATION EXPECTED FROM THIS WITH THE EXCEPTION OF A FLURRY FOR THE POCONOS AND MORNING CLOUDS. THE MAIN CHALLENGE WILL BE THE FRONTAL TIMING AND TEMPERATURES. THE ECMWF IS SLOWER AND WARMER GIVING PHL A GOOD SHOT TO GET WELL INTO THE 40`S. HOWEVER THE GFS IS FASTER WITH PHL BARELY HITTING 40. FRONTAL PASSAGE NW OF PHL SHOULD OCCUR IN THE MORNING, LIMITING THE MODEL SPREAD FOR TEMPERATURES IN THIS REGION. A SLOWER FRONTAL PASSAGE ALLOWS FOR COASTAL AREAS TO SEE MORE SOUTHERLY FLOW AND MAKE A RUN AT 50. WENT A COUPLE OF DEGREES BELOW MAV/MET NORTHWEST GIVEN NW FLOW AND WENT ABOVE MAV/MET ALONG THE COAST DUE TO THE SOUTHERLY FLOW. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... HIGHLIGHTS... * TEMPERATURES WELL BELOW NORMAL FRIDAY W/SNOW SHOWERS POSSIBLE IN THE POCONOS * CHANCE OF RAIN LATE SUNDAY INTO EARLY NEXT WEEK W/TEMPERATURES ABOVE NORMAL * TEMPERATURES PROJECTED TO RETURN TO SEASONABLE LEVELS MID-WEEK DETAILS... A PATTERN CHANGE IS UNDERWAY AS THE PERSISTENT BLOCKING PATTERN ALONG THE WEST COAST OF NOAM /POSITIVE HEIGHT ANOMALIES/ BREAKS DOWN...ALLOWING A VIGOROUS S/WV TO MOVE INTO THE FOUR CORNERS REGION ON SATURDAY...LEADING TO STRONG DOWNSTREAM HEIGHT RISES ACROSS THE E CONUS, W/THE MID-LEVEL TROUGH GRADUALLY LIFTING TO THE NORTHEAST ON FRIDAY AND RIDGING TAKING ITS PLACE BY MONDAY. THIS WILL LEAD TO A WARMING TREND...WITH MAXIMUM TEMPERATURES WELL BELOW NORMAL ON FRIDAY MODERATING TO ABOVE NORMAL LEVELS BY MONDAY. THE GFS...ECMWF AND THEIR RESPECTIVE ENSEMBLES ARE IN GENERAL AGREEMENT ON TAKING THE SOUTHERN STREAM S/WV INTO THE FOUR- CORNERS REGION ON SATURDAY...BUT DIFFER ON THE STRENGTH OF THE NORTHERN STREAM S/WV COMING ASHORE IN THE PACIFIC NORTHWEST AT THAT TIME. THIS HAS IMPLICATIONS FOR THE DEGREE OF DOWNSTREAM PHASING OVER THE UPPER MS VALLEY ON SUNDAY AND THE EVOLUTION OF THE RESULTANT STORM SYSTEM. THE MODELS AGREE ON A STORM TRACK OVER THE MICHIGAN PENINSULA...BUT THE WEAKER NORTHERN STREAM SHORTWAVE HAS LEAD TO A FASTER SOLUTION BY 24-HOURS...W/THE LOW NOW PROGGED OVER THE MICHIGAN PENINSULA AT 12Z MONDAY. BUT AT D+5 IT/S TOUGH TO SPECULATE IF THIS TRACK AND TIMING WILL HOLD. NEVERTHELESS...THE PATTERN FAVORS A STORM TRACK TO THE WEST OF THE APPALACHIANS AS WELL AS WARMER AIR MOVING INTO THE E CONUS... BUT UNCERTAINTY IN THE TRACK AND STRENGTH OF THIS STORM SYSTEM TRANSLATES INTO UNCERTAINTY IN THE TEMPERATURE FORECAST SUNDAY AND BEYOND. LOOKING AHEAD TO TUESDAY AND WEDNESDAY...A FRONTAL PASSAGE DURING THIS TIME FRAME LOOKS TO DELIVER A REINFORCING SHOT OF COLD AIR...WHILE CYCLOGENSIS MAY TAKE PLACE INVOF THE EAST COAST, WHICH BEARS WATCHING AS THE NAO IS PROJECTED TO GO NEGATIVE. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CLEAR SKIES THIS AFTERNOON AND EVENING WILL GIVE WAY TO SCATTERED AND BROKEN MID TO HIGH LEVEL CLOUDS WITH THE PASSAGE OF A WARM FRONT TONIGHT. THIS WILL ALSO RESULT IN A WIND SHIFT TO THE SOUTHWEST. AFTER SOME GUSTS AROUND 15 KNOTS THIS AFTERNOON, WINDS SHOULD SUBSIDE TO AROUND 10 KNOTS TONIGHT. VFR. ON THURSDAY, WITH THE PASSAGE OF A COLD FRONT THE WINDS WILL GRADUALLY SHIFT BACK TO THE WEST BY AFTERNOON WITH INCREASING GUSTS REACHING 25 KNOTS. MID TO HIGH LEVEL CLOUDS WILL CLEAR OUT BY DAYS END. VFR. OUTLOOK... FRIDAY...VFR. NORTHWEST WINDS MAY GUST TO 25 KNOTS DURING THE LATE MORNING THRU EARLY AFTERNOON HOURS. SATURDAY...VFR. SUNDAY AND MONDAY...MVFR POSSIBLE IN LOW CEILINGS AND -SHRA ESPECIALLY LATE SUNDAY AND PARTICULARLY ON MONDAY. && .MARINE... SEAS AND WINDS SHOULD INCREASE THIS EVENING. THE ENVIRONMENT WILL BE FAVORABLE FOR SOME SOUTHWEST GALE FORCE WIND GUSTS AROUND 35 KNOTS ON THE OCEAN WATERS FROM 04-12Z THURSDAY. A GALE WARNING IS IN EFFECT. THE GALE GUSTS MAY NOT BE SUSTAINED THROUGH THIS WHOLE PERIOD BUT MAY BE MORE OF A INTERMITTENT VARIETY. SCA CONDITIONS LIKELY WILL CONTINUE THROUGHOUT THE DAY THURSDAY WITH NORTHWESTERLY WINDS. OUTLOOK... FRIDAY...SCA WINDS AND SEAS LIKELY THURSDAY NIGHT AND FRIDAY... SLOWLY SUBSIDING TO SUB-SCA CONDITIONS FRIDAY NIGHT. SATURDAY AND SUNDAY...SUB-SCA CONDITIONS ARE ANTICIPATED ATTM. MONDAY...A GALE WARNING MAY BE NEEDED. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...GALE WARNING FROM 11 PM THIS EVENING TO 7 AM EST THURSDAY FOR ANZ450>455. SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST THURSDAY FOR ANZ430-431. && $$ SYNOPSIS...FRANCK NEAR TERM...GAINES SHORT TERM...GAINES LONG TERM...FRANCK AVIATION...FRANCK/GAINES MARINE...FRANCK/GAINES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 PM CST WED NOV 19 2014 .SHORT TERM...TONIGHT THROUGH FRIDAY... 300 PM...COLD FRONT WELL EAST OF THE AREA THIS AFTERNOON WITH SCATTERED LIGHT SNOW SHOWERS AND FLURRIES AS ANOTHER PUNCH OF COLDER AIR SPREADS ACROSS THE REGION WITH SLOWLY FALLING TEMPS THIS AFTERNOON. EXTENSIVE CLOUD COVER BACK THROUGH THE UPPER MIDWEST AND EXPECT MOSTLY CLOUDY SKIES INTO THE OVERNIGHT HOURS WITH SOME SCATTERING ACROSS THE SOUTHWEST TOWARD MORNING. FLURRIES AND FEW SNOW SHOWERS WILL ALSO CONTINUE THIS EVENING AND POSSIBLY INTO THE OVERNIGHT HOURS BUT ONLY A DUSTING...AT THE MOST...WILL BE POSSIBLE IN SOME LOCATIONS. WINDS HAVE ALSO INCREASED WITH GUSTS 35 TO 40 MPH IN MANY LOCATIONS. THE STRONGEST WINDS WILL DIMINISH WITH SUNSET...BUT IT WILL STILL REMAIN QUITE BLUSTERY THROUGH THE EVENING WITH WINDS STILL IN THE 10-15 MPH OVERNIGHT. THESE WINDS COMBINED WITH THE EXPECTED CLOUD COVER WILL LIKELY KEEP LOW TEMPS IN THE TEENS BY MORNING...THOUGH WIND CHILLS WILL BE AROUND ZERO. STILL BREEZY ON THURSDAY WITH HIGHS STRUGGLING INTO THE MID 20S WITH A RIDGE OF HIGH PRESSURE MOVING ACROSS THE AREA THURSDAY NIGHT. WITH MOSTLY CLEAR SKIES AND LIGHT WINDS...TEMPS WILL LIKELY TANK WITH LOWS IN THE SINGLE DIGITS IN MANY LOCATIONS BY FRIDAY MORNING. WINDS TURN LIGHT SOUTHERLY FRIDAY AS THE HIGH DEPARTS WITH TEMPS REBOUNDING BACK INTO THE UPPER 20S TO NEAR 30 ACROSS THE SOUTH WITH SOME SUNSHINE AT LEAST THRU EARLY AFTERNOON. CMS && .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY... 300 PM...MULTIPLE FORECAST CONCERNS AND CHALLENGES INCLUDING FREEZING RAIN FRIDAY NIGHT/EARLY SATURDAY MORNING...POSSIBLE HEAVY RAIN SUNDAY...FOG SATURDAY NIGHT INTO SUNDAY...THEN POSSIBLE VERY STRONG WINDS SUNDAY NIGHT INTO MONDAY. BROAD WEAK LIFT COMBINED WITH STRONG WARM AIR ADVECTION WILL ALLOW LIGHT PRECIPITATION TO BEGIN FALLING FRIDAY EVENING...FROM SOUTH TO NORTH ACROSS THE AREA. AFTER A WEEK AND A HALF OF MAINLY SUB FREEZING TEMPS AND HIGH TEMPS NOT EXPECTED TO REACH FREEZING FRIDAY AFTERNOON...IN ADDITION TO VERY DRY LOW LEVELS...SURFACES AND SURFACE TEMPERATURES WILL BE BELOW FREEZING AS PRECIPITATION BEGINS FRIDAY EVENING. SOUNDINGS SHOW A VERY DEEP WARM LAYER SO WHILE THERE COULD BE A LITTLE SLEET AT ONSET...BULK OF PRECIP SHOULD BE LIGHT FREEZING RAIN. RATHER GOOD CONSISTENCY FROM THE GEM/GFS/ECMWF OF BOTH TEMPS AND DEWPOINTS SLOWLY BUT STEADILY RISING LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING AND HAVE THE FREEZING LINE TO ABOUT THE I-80 CORRIDOR BY 12Z SATURDAY MORNING...WHICH IS ACTUALLY SLOWER/COLDER THAN THESE MODELS. THE NAM KEEPS TEMPS WELL BELOW FREEZING INTO MID MORNING SATURDAY AND CONSIDERING WINDS ARE ALL SOUTHERLY DURING THIS EVENT...WARMER/MORE MOIST AIR MIGHT ARRIVE SOONER RATHER THAN LATER. NEVERTHELESS...ANY AMOUNT OF ICING WILL CAUSE SIGNIFICANT PROBLEMS...SO AS THIS TIME PERIOD APPROACHES...THESE TRENDS WILL BECOME MORE IMPORTANT FOR PRECIP TIMING/DURATION. AS TEMPS AND DEWPOINTS CONTINUE TO INCREASE SATURDAY...HIGHS MAY REACH THE MID 40S BUT WILL LIKELY BE ACCOMPANIED BY PERIODS OF LIGHT RAIN OR DRIZZLE. WITH NO CHANGES SATURDAY NIGHT...THIS MOIST AIR OVER THE COLD GROUND WILL LIKELY RESULT IN FOG AND ADDED THIS TO THE FORECAST. HOW DENSE IT BECOMES OR HOW LONG IT PERSISTS IS A BIT UNCERTAIN THOUGH. LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS SATURDAY NIGHT AND TURN NORTH AND DEEPEN AS IT REACHES NORTHERN IL SUNDAY AFTERNOON INTO SUNDAY EVENING. THE LOW CONTINUES TO DEEPEN TO AS LOW AS 973MB BY MONDAY MORNING OVER NORTHEAST WI AS SHOWN BY THE 12Z GFS/ECMWF. WHILE PLENTY WARM ENOUGH FOR NO WINTER PRECIP CONCERNS AS IT MOVES ACROSS THE AREA...THE TRACK WILL BE IMPORTANT REGARDING WHERE THE HEAVIEST RAINS FALL. PRECIPITABLE WATER VALUES REACH INTO THE 1.0 TO 1.2 INCH RANGE BY SUNDAY AFTERNOON ALONG WITH EVENT TOTAL QPF FROM THE MODELS IN THE 1 TO 2 INCH RANGE OVER PARTS OF THE REGION...ESPECIALLY TO THE WEST AND SOUTHWEST. TOO EARLY FOR SPECIFIC RAINFALL AMOUNTS...BUT GIVEN THE AMOUNT OF MOISTURE TO WORK WITH...HEAVY RAINFALL WILL BE A POSSIBILITY AND IF THIS DOES MATERIALIZE...IT WILL BE FALLING ONTO FROZEN OR PARTIALLY FROZEN GROUND. THUS...AS THIS TIME PERIOD APPROACHES... HYDRO ISSUES MAY BECOME A CONCERN. AFTER THE LOW PASSES...FORECAST SOUNDINGS SUGGEST VERY STRONG WINDS AND GUSTS MAY DEVELOP SUNDAY NIGHT AND CONTINUE MONDAY AND MONDAY NIGHT. AS COLDER AIR SPREADS ACROSS THE REGION SUNDAY NIGHT INTO MONDAY...LINGERING LIGHT RAIN WILL MIX WITH THEN CHANGE TO LIGHT SNOW. WHILE THE DETAILS ARE STILL SEVERAL DAYS AWAY...THERE DOES APPEAR TO BE SOME POTENTIAL FOR LIGHT SNOW OR SNOW SHOWERS BY MONDAY AFTERNOON INTO MONDAY EVENING. COLD AND BELOW NORMAL TEMPS WILL THEN CONTINUE THROUGH MID WEEK. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * LIGHT SNOW SHOWERS MIDDAY INTO EARLY AFTERNOON WITH MVFR CIGS/VSBY AT TIMES. * GUSTY WEST WINDS RETURN LATE THIS MORNING WITH PEAK GUSTS ARND 25-28 KT THIS AFTN. KMD //DISCUSSION...UPDATED 20Z... SNOW SHOWERS IN SOUTHWEST WISCONSIN HAVE A HISTORY OF 2-5SM VISIBILITY FOR A 2-3 HOUR PERIOD AT MOST...BUT THIS FAR SOUTH VSBYS HAVE STRUGGLED TO GET LOWER THAN 5 SM. THE FORCING ASSOCIATED WITH THIS ACTIVITY COMES THROUGH NORTHERN ILLINOIS THIS AFTERNOON. IT DOES WEAKEN SOMEWHAT AS IT PROGRESSES SOUTH AND EAST...BUT WE WILL HAVE MORE UNSTABLE LOW LEVELS WHICH WILL SUPPORT SOME LIGHT SNOW SHOWERS. MUCH OF THIS ACTIVITY WILL BE LIGHT AND NON ACCUMULATING DUE TO THE GUSTY WEST WINDS WITH LARGELY LOW END VFR CONDITIONS. CIGS TREND BACK TO VFR TONIGHT WITH SOME CLEARING POSSIBLE. WINDS REMAIN WESTERLY THROUGH THE PERIOD...STRONGEST THIS AFTERNOON. KMD //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH IN A PERIOD OF NON ACCUMULATING SNOW SHOWERS THIS AFTERNOON WITH FLURRIES POSSIBLE INTO THE EVENING. MEDIUM THAT MVFR VSBY SHOULD BE LESS FREQUENT THAN VFR. * HIGH FOR PERIODS OF MVFR CIGS THIS AFTERNOON. * HIGH FOR WIND TRENDS. KMD //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...CHANCE OF A WINTRY MIX OVERNIGHT. IFR LIKELY OVERNIGHT. SATURDAY...WINTRY MIX BCMG RAIN. IFR LIKELY. SUNDAY...RAIN AND IFR LIKELY. MONDAY...CHC -RASN BCMG -SN. MVFR TO IFR CIGS. TUESDAY...VFR. JEE && .MARINE... 134 PM CST A VERY ACTIVE PATTERN CONTINUES FOR LAKE MICHIGAN. HAVE MADE NO CHANGES TO THE GOING GALE WARNING OR SMALL CRAFT ADVISORY AS FORECAST CONDITIONS REMAIN ON TRACK. A SURFACE TROUGH CROSSING LAKE MICHIGAN TODAY HAD BROUGHT A BRIEF LULL TO THE WINDS EARLIER TODAY...BUT FOLLOWING THE PASSAGE OF THIS TROUGH...WINDS HAVE SHIFTED FROM SWLY TO WLY EARLY THIS AFTERNOON AND ARE RAMPING BACK UP TO PREVAILING WEST GALES. A SERIES OF MID LEVEL IMPULSES ROTATING AROUND THE PERIPHERY OF A DEEP UPPER LOW CENTERED OVER THE HUDSON BAY AREA WILL CONTINUE THE INFLUX OF UNSEASONABLY COLD AIR INTO THE GREAT LAKES REGION. THESE IMPULSES WILL ALLOW SURFACE LOW PRESSURE TO DEEPEN OVER THE UPPER GREAT LAKES TONIGHT AS HIGH PRESSURE BUILDS ACROSS THE CENTRAL PLAINS. THE SFC LOW WILL CONTINUE TO LIFT OUT TO THE NORTHEAST THROUGH ERN QUEBEC AND INTO NOVA SCOTIA THURSDAY AND THURSDAY NIGHT AS THE HIGH PRESSURE BUILDS ACROSS THE MIDDLE MISSISSIPPI VALLEY. THE PRESSURE GRADIENT OVER THE LAKE WILL GRADUALLY WEAKEN ...BUT WITH THE CENTER OF THE HIGH SLIDING SOUTH OF THE LAKE...BRISK WEST TO NORTHWEST WINDS WILL PERSIST THROUGH THURSDAY...THOUGH WITH A WEAKENING GRADIENT...WINDS SHOULD DROP BELOW GALE FORCE BY LATE THURSDAY MORNING. THE RIDGE AXIS SHOULD CROSS THE LAKE THURSDAY NIGHT AND FRIDAY MORNING...ALLOWING WINDS TO DECREASE FURTHER...AND ANTICIPATE THAT THE SMALL CRAFT ADVISORY CONDITIONS FOR THE NEARSHORE WATERS SHOULD STILL COME TO THE END DURING THE DAY ON FRIDAY...AS RESIDUAL WAVE ACTION SUBSIDES...THOUGH THE ADVISORY CRITERIA WAVES SHOULD OUTLAST THE ADVISORY CRITERIA WINDS. THE PERIOD FOR THE POTENTIAL FOR HAZARDOUS CONDITIONS OVER THE LAKE WILL BE RELATIVELY BRIEF. AS THE SFC HIGH MOVES OFF THE SOUTH ATLANTIC COAST OVER THE WEEKEND...A TROUGH OF LOW PRESSURE WILL DEVELOP OVER THE WESTERN PLAINS...SETTING UP STRENGTHENING...MORE SOUTHERLY WINDS SATURDAY NIGHT AND SUNDAY. BY EARLY NEXT WEEK...THE LONGER RANGE MODELS ARE INDICATING THAT TWO LOW PRESSURE SYSTEM WILL EVENTUALLY DEVELOP...ONE OVER THE SOUTHERN CANADIAN PRAIRIES AND ANOTHER OVER THE RED RIVER VALLEY. THE FORECAST MODELS ARE SHOWING THAT THE TWO SYSTEM SHOULD EVENTUALLY MERGE SOMEWHERE OVER THE UPPER MIDWEST AND DEEPEN OVER THE GREAT LAKES REGION...POSSIBLY BRINGING ANOTHER PERIOD OVER GALES TO THE LAKE...POSSIBLY AS EARLY AS MONDAY AND THEN CONTINUING THROUGH THE MIDDLE OF NEXT WEEK. HOWEVER THERE IS SOME DISAGREEMENT AMONG THE MODELS AS THE EXACTLY WHERE THE CONSOLIDATED LOW WILL DEVELOP AND HOW DEEP IT WILL BECOME...SO WILL GO WITH A RELATIVELY CONSERVATIVE FORECAST FOR NOW...BUT ANTICIPATE THAT THE FORECAST WINDS IN THE LATTER PORTIONS OF THE PERIOD WILL INCREASE WITH LATER UPDATES. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 255 PM CST Wed Nov 19 2014 .SHORT TERM...(Tonight) ISSUED AT 254 PM CST WED NOV 19 2014 Breezy and cold weather will be the rule across central Illinois tonight. 19z/1pm surface analysis shows cold front exiting into Indiana, while ridge of high pressure builds into the Plains. Pressure gradient between these two features will continue to create W/NW wind gusts of 25 to 35 mph this afternoon. Gustiness will begin to subside toward sunset: however, with ridge axis staying west of Illinois until Thursday, gradient will remain tight enough to support winds of around 10 mph through the night. Clouds and a few flurries will prevail early in the evening, with the big weather question being how fast skies will clear later tonight. Widespread cloud cover is currently evident on satellite imagery from Illinois northwestward to the US/Canada border: however, several holes in the overcast have developed upstream across the Dakotas/Minnesota. All model guidance suggests clouds will begin to scatter this evening, with mostly clear conditions expected overnight. Given current satellite imagery and continued deep northwesterly flow, think this is too fast. Have therefore gone with a slower clearing trend more in line with the HRRR solution. End result will be cloudy skies this evening, followed by gradual clearing overnight. Due to the clouds and continued breeze, have gone with the higher end of numeric guidance for lows tonight, with readings ranging from 14 degrees in Galesburg to around 20 degrees south of I-70. && .LONG TERM...(Thursday through Wednesday) ISSUED AT 254 PM CST WED NOV 19 2014 Moisture channel satellite imagery and the morning upper air shows deep upper level trof over eastern US with main jet from central Canada into the midwest. This upper flow will bring in another surge of cold air, with cold surface high moving into region during the day Thursday and Thursday night. With clear skies by Thursday night, have lowered Friday morning lows some due to light winds and cold airmass. Main precipitation concern is for Friday evening and Friday night, as overrunning precipitation develops from AR into MO ahead of digging shortwave in the southwest US. Precipitation will reach central IL Friday evening, so temperature forecast will be critical, as warm air aloft will produce precipitation in form of rain. A detailed look at the model surface temperature forecasts depicts EUR warmest, GFS, and NAM coolest. Feel the warming temperatures will be blend of GFs and NAM, as conditions will start off cooler Friday morning, as lowered morning lows. Feel current forecast grids a good compromise and so looks like pcpn will start in evening Friday as light freezing rain, with the freezing line gradually moving to the northeast overnight. Pcpn amounts still look to be light, so impacts will be on the light scale. Saturday pcpn will be rain, as overrunning pcpn continues to develop and move into the region. Strongest dynamics look to be on Sunday, as the shortwave system and surface low approach and move through region. Models are similar in the movement of system, with low center tracking just west of the cwa Sunday, with front moving through area and gusty winds. Vertical stacking of the upper low over Lake MI on sunday night. Cool conditions will conditions into midweek, as the upper low gradually moves off and allows another cool high pressure area into the midwest. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 1209 PM CST WED NOV 19 2014 Cold front has pushed east of the central Illinois terminals late this morning, resulting in strong W/NW winds across the board. Based on 12z forecast soundings and the latest upstream observations, wind gusts will generally remain in the 25 to 30kt range before gradually subsiding toward sunset. Even though winds will drop off tonight, pressure gradient will remain tight enough to support sustained winds of around 10kt through the entire night. 17z/11am satellite imagery shows low cloud cover spilling into central Illinois behind the departing front, with the leading edge currently approaching the I-57 corridor. A narrow band of MVFR ceilings are noted across the Illinois River Valley, but these should gradually rise to VFR over the next couple of hours. Have therefore included MVFR conditions at KPIA/KBMI/KSPI through 20/21z. After that, the big question will be how fast skies clear tonight. Due to ample upstream cloud cover within the northwesterly flow pattern, have trended toward the more pessimistic HRRR solution. End result will be a slow clearing trend after dark, with ceilings scattering out at KSPI by 03z and further northeast at KCMI by around 06z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Barnes LONG TERM...Goetsch AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
151 PM CST WED NOV 19 2014 .SHORT TERM... 335 AM CST TODAY THROUGH FRIDAY... MAIN FOCUS IN NEAR TERM IS WITH CLIPPER-TYPE SYSTEM MOVING THROUGH THE REGION THIS MORNING...AND THE POTENTIAL FOR SOME LIGHT ACCUMULATING SNOW MAINLY ACROSS FAR NORTHERN/NORTHEAST IL. OTHER HIGHLIGHTS...OR LOW LIGHTS AS THE CASE MAY BE...THROUGH FRIDAY ARE CONTINUED SUB-NORMAL CHILLY TEMPERATURES AND THE POTENTIAL FOR SOME LIGHT FREEZING RAIN FRIDAY NIGHT INTO EARLY SATURDAY MORNING AHEAD OF A SYSTEM WHICH WILL BRING RAIN AND WARMER WEATHER OVER THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY DEPICTS A SHORT-WAVE DIGGING SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY AND APPROACHING WI/IL AT 0830Z. SURFACE TROUGH REFLECTION WAS OVER SOUTHERN MN/EAST CENTRAL IA...WITH FAIRLY IMPRESSIVE SURFACE PRESSURE FALLS SPREADING INTO SOUTHERN WI/IL AND BACKING WINDS TO THE SOUTH AND RAISING TEMPS. RADAR RETURNS FROM MID-LEVEL CLOUDS HAVE DEVELOPED SOUTHEAST FROM TWIN CITIES AREA...THOUGH DRY LOW LEVEL AIR SO FAR HAS SLOWED DEVELOPMENT OF SNOW AT THE SURFACE. TRACK OF SYSTEM...RADAR TRENDS AND HIGH-RES HRRR GUIDANCE ALL INDICATE BEST POTENTIAL FOR MEASURABLE SNOW THROUGH THE EARLY MORNING HOURS WILL BE ALONG A ROUGHLY MSP-MKE CORRIDOR...WITH GENERALLY LIGHT AMOUNTS OF AN INCH OR LESS EXPECTED ACROSS FAR NORTHEAST IL AND PARTS OF NORTHERN IN. FORECAST SOUNDINGS INDICATE DRY AIR ARRIVING IN MID-LEVELS BY MID-LATE MORNING AND LIMITING BEST FORCING FOR SNOW TO A ONLY A FEW HOURS THIS AM. SURFACE TROUGH PASSES MID-DAY...WITH RENEWED COLD ADVECTION AND EXTENSIVE UPSTREAM CLOUDINESS SUPPORTING SCATTERED FLURRIES THIS AFTERNOON AS LOW-LEVEL THERMAL PROFILES COOL AGAIN. MOISTURE BECOMES VERY SHALLOW TONIGHT AND THURSDAY...DECREASING POTENTIAL FOR FLURRIES DESPITE ANOTHER DIGGING SHORT WAVE ACROSS THE WESTERN LAKES. THE MAIN LARGE-SCALE UPPER TROUGH AXIS THEN SHIFTS EAST THURSDAY NIGHT...ALLOWING SURFACE HIGH PRESSURE TO SPREAD EAST ACROSS THE AREA BY FRIDAY MORNING. TEMPERATURES WERE RISING INTO THE 20S WITH THE SOUTH WINDS THIS MORNING...WITH HIGHS EXPECTED TO TOP OUT IN THE MID 20S TO LOW 30S TODAY WITH THE MILDEST TEMPS ACROSS THE FAR EAST/SOUTHEAST CWA. COLDER TEMPS AGAIN TONIGHT AND THURSDAY...WITH THE COLDEST EXPECTED EARLY FRIDAY MORNING IN THE VICINITY OF THE SURFACE RIDGE AXIS. LOWS IN THE SINGLE DIGITS TO LOWER TEENS ARE LIKELY FRIDAY MORNING WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. MUCH-TOUTED CHANGE IN THE UPPER PATTERN WILL BE UNDERWAY FRIDAY... AS FLOW DE-AMPLIFIES AND UPPER TROUGH MOVES ACROSS THE SOUTHWESTERN STATES AND ACROSS THE CENTRAL AND SOUTHERN ROCKIES FRIDAY NIGHT. ALONG WITH A DISTURBANCE MOVING ACROSS CENTRAL CANADA...THIS WILL SET UP SOUTHERLY RETURN FLOW INTO THE REGION FRIDAY NIGHT WITH ASSOCIATED WARM/MOIST ADVECTION. MODELS CONTINUE TO INDICATE DEVELOPMENT OF SOME LIGHT PRECIP OVERNIGHT...WITH FORECAST SOUNDINGS INDICATING ELEVATED WARM LAYER TEMPS APPROACHING +5C WHILE SFC TEMPS ARE BELOW FREEZING. THIS SUPPORTS THE POTENTIAL FOR SOME LIGHT FREEZING RAIN OR SLEET FRIDAY NIGHT...BEFORE WARM ADVECTION EVENTUALLY RAISES SURFACE TEMPS ABOVE FREEZING ON SATURDAY. MODELS HAVE TRENDED A LITTLE SLOWER WITH ARRIVAL OF LIGHT PRECIP...THOUGH ALSO SOMEWHAT COLDER INITIALLY AT THE SURFACE. WILL CONTINUE TO MENTION POTENTIAL FOR FREEZING RAIN/SLEET AND WILL HAVE TO MONITOR TRENDS FOR THE POTENTIAL OF SOME LIGHT ICE ACCUMULATION LATER FRIDAY NIGHT INTO EARLY SATURDAY. RATZER && .LONG TERM... 335 AM CST SATURDAY THROUGH TUESDAY... LONGER RANGE MODEL SOLUTIONS CONTINUE TO LIFT SOUTHWESTERN TROUGH TOWARD THE AREA OVER THE WEEKEND...WITH LOW LEVELS QUICKLY WARMING ABOVE FREEZING SATURDAY MORNING AND CHANGING ANY MIXED PRECIP OVER TO RAIN. 00Z GFS/ECMWF HAVE COME INTO BETTER AGREEMENT IN TIMING THE NEGATIVELY-TILTED SOUTHWESTERN SHORT WAVE AND DEEPENING SURFACE LOW TO LIFT ACROSS THE FORECAST AREA SUNDAY AFTERNOON/EVENING...WITH TEMPS RISING INTO THE BALMY 45-50 RANGE. SOME DIFFERENCES REMAIN WITH THE DETAILS OF PHASING THIS SYSTEM WITH A NORTHERN STREAM DEVELOPING CLOSED UPPER LOW OVER THE REGION SUNDAY NIGHT INTO MONDAY...THOUGH REASONABLY SIMILAR IN THE IDEA OF MILD WITH RAIN/SHOWERS EVENTUALLY GIVING WAY TO LIGHTER RAIN/SNOW TRANSITION MONDAY-MONDAY NIGHT AND TO LINGERING SNOW SHOWERS TUESDAY AS WE SHIFT BACK TO A DEEP EASTERN CONUS UPPER TROUGH AND COLDER WEATHER EARLY NEXT WEEK. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * LIGHT SNOW SHOWERS MIDDAY INTO EARLY AFTERNOON WITH MVFR CIGS/VSBY AT TIMES. * GUSTY WEST WINDS RETURN LATE THIS MORNING WITH PEAK GUSTS ARND 25-28 KT THIS AFTN. KMD //DISCUSSION...UPDATED 20Z... SNOW SHOWERS IN SOUTHWEST WISCONSIN HAVE A HISTORY OF 2-5SM VISIBILITY FOR A 2-3 HOUR PERIOD AT MOST...BUT THIS FAR SOUTH VSBYS HAVE STRUGGLED TO GET LOWER THAN 5 SM. THE FORCING ASSOCIATED WITH THIS ACTIVITY COMES THROUGH NORTHERN ILLINOIS THIS AFTERNOON. IT DOES WEAKEN SOMEWHAT AS IT PROGRESSES SOUTH AND EAST...BUT WE WILL HAVE MORE UNSTABLE LOW LEVELS WHICH WILL SUPPORT SOME LIGHT SNOW SHOWERS. MUCH OF THIS ACTIVITY WILL BE LIGHT AND NON ACCUMULATING DUE TO THE GUSTY WEST WINDS WITH LARGELY LOW END VFR CONDITIONS. CIGS TREND BACK TO VFR TONIGHT WITH SOME CLEARING POSSIBLE. WINDS REMAIN WESTERLY THROUGH THE PERIOD...STRONGEST THIS AFTERNOON. KMD //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH IN A PERIOD OF NON ACCUMULATING SNOW SHOWERS THIS AFTERNOON WITH FLURRIES POSSIBLE INTO THE EVENING. MEDIUM THAT MVFR VSBY SHOULD BE LESS FREQUENT THAN VFR. * HIGH FOR PERIODS OF MVFR CIGS THIS AFTERNOON. * HIGH FOR WIND TRENDS. KMD //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...CHANCE OF A WINTRY MIX OVERNIGHT. IFR LIKELY OVERNIGHT. SATURDAY...WINTRY MIX BCMG RAIN. IFR LIKELY. SUNDAY...RAIN AND IFR LIKELY. MONDAY...CHC -RASN BCMG -SN. MVFR TO IFR CIGS. TUESDAY...VFR. JEE && .MARINE... 134 PM CST A VERY ACTIVE PATTERN CONTINUES FOR LAKE MICHIGAN. HAVE MADE NO CHANGES TO THE GOING GALE WARNING OR SMALL CRAFT ADVISORY AS FORECAST CONDITIONS REMAIN ON TRACK. A SURFACE TROUGH CROSSING LAKE MICHIGAN TODAY HAD BROUGHT A BRIEF LULL TO THE WINDS EARLIER TODAY...BUT FOLLOWING THE PASSAGE OF THIS TROUGH...WINDS HAVE SHIFTED FROM SWLY TO WLY EARLY THIS AFTERNOON AND ARE RAMPING BACK UP TO PREVAILING WEST GALES. A SERIES OF MID LEVEL IMPULSES ROTATING AROUND THE PERIPHERY OF A DEEP UPPER LOW CENTERED OVER THE HUDSON BAY AREA WILL CONTINUE THE INFLUX OF UNSEASONABLY COLD AIR INTO THE GREAT LAKES REGION. THESE IMPULSES WILL ALLOW SURFACE LOW PRESSURE TO DEEPEN OVER THE UPPER GREAT LAKES TONIGHT AS HIGH PRESSURE BUILDS ACROSS THE CENTRAL PLAINS. THE SFC LOW WILL CONTINUE TO LIFT OUT TO THE NORTHEAST THROUGH ERN QUEBEC AND INTO NOVA SCOTIA THURSDAY AND THURSDAY NIGHT AS THE HIGH PRESSURE BUILDS ACROSS THE MIDDLE MISSISSIPPI VALLEY. THE PRESSURE GRADIENT OVER THE LAKE WILL GRADUALLY WEAKEN ...BUT WITH THE CENTER OF THE HIGH SLIDING SOUTH OF THE LAKE...BRISK WEST TO NORTHWEST WINDS WILL PERSIST THROUGH THURSDAY...THOUGH WITH A WEAKENING GRADIENT...WINDS SHOULD DROP BELOW GALE FORCE BY LATE THURSDAY MORNING. THE RIDGE AXIS SHOULD CROSS THE LAKE THURSDAY NIGHT AND FRIDAY MORNING...ALLOWING WINDS TO DECREASE FURTHER...AND ANTICIPATE THAT THE SMALL CRAFT ADVISORY CONDITIONS FOR THE NEARSHORE WATERS SHOULD STILL COME TO THE END DURING THE DAY ON FRIDAY...AS RESIDUAL WAVE ACTION SUBSIDES...THOUGH THE ADVISORY CRITERIA WAVES SHOULD OUTLAST THE ADVISORY CRITERIA WINDS. THE PERIOD FOR THE POTENTIAL FOR HAZARDOUS CONDITIONS OVER THE LAKE WILL BE RELATIVELY BRIEF. AS THE SFC HIGH MOVES OFF THE SOUTH ATLANTIC COAST OVER THE WEEKEND...A TROUGH OF LOW PRESSURE WILL DEVELOP OVER THE WESTERN PLAINS...SETTING UP STRENGTHENING...MORE SOUTHERLY WINDS SATURDAY NIGHT AND SUNDAY. BY EARLY NEXT WEEK...THE LONGER RANGE MODELS ARE INDICATING THAT TWO LOW PRESSURE SYSTEM WILL EVENTUALLY DEVELOP...ONE OVER THE SOUTHERN CANADIAN PRAIRIES AND ANOTHER OVER THE RED RIVER VALLEY. THE FORECAST MODELS ARE SHOWING THAT THE TWO SYSTEM SHOULD EVENTUALLY MERGE SOMEWHERE OVER THE UPPER MIDWEST AND DEEPEN OVER THE GREAT LAKES REGION...POSSIBLY BRINGING ANOTHER PERIOD OVER GALES TO THE LAKE...POSSIBLY AS EARLY AS MONDAY AND THEN CONTINUING THROUGH THE MIDDLE OF NEXT WEEK. HOWEVER THERE IS SOME DISAGREEMENT AMONG THE MODELS AS THE EXACTLY WHERE THE CONSOLIDATED LOW WILL DEVELOP AND HOW DEEP IT WILL BECOME...SO WILL GO WITH A RELATIVELY CONSERVATIVE FORECAST FOR NOW...BUT ANTICIPATE THAT THE FORECAST WINDS IN THE LATTER PORTIONS OF THE PERIOD WILL INCREASE WITH LATER UPDATES. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
135 PM CST WED NOV 19 2014 .SHORT TERM... 335 AM CST TODAY THROUGH FRIDAY... MAIN FOCUS IN NEAR TERM IS WITH CLIPPER-TYPE SYSTEM MOVING THROUGH THE REGION THIS MORNING...AND THE POTENTIAL FOR SOME LIGHT ACCUMULATING SNOW MAINLY ACROSS FAR NORTHERN/NORTHEAST IL. OTHER HIGHLIGHTS...OR LOW LIGHTS AS THE CASE MAY BE...THROUGH FRIDAY ARE CONTINUED SUB-NORMAL CHILLY TEMPERATURES AND THE POTENTIAL FOR SOME LIGHT FREEZING RAIN FRIDAY NIGHT INTO EARLY SATURDAY MORNING AHEAD OF A SYSTEM WHICH WILL BRING RAIN AND WARMER WEATHER OVER THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY DEPICTS A SHORT-WAVE DIGGING SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY AND APPROACHING WI/IL AT 0830Z. SURFACE TROUGH REFLECTION WAS OVER SOUTHERN MN/EAST CENTRAL IA...WITH FAIRLY IMPRESSIVE SURFACE PRESSURE FALLS SPREADING INTO SOUTHERN WI/IL AND BACKING WINDS TO THE SOUTH AND RAISING TEMPS. RADAR RETURNS FROM MID-LEVEL CLOUDS HAVE DEVELOPED SOUTHEAST FROM TWIN CITIES AREA...THOUGH DRY LOW LEVEL AIR SO FAR HAS SLOWED DEVELOPMENT OF SNOW AT THE SURFACE. TRACK OF SYSTEM...RADAR TRENDS AND HIGH-RES HRRR GUIDANCE ALL INDICATE BEST POTENTIAL FOR MEASURABLE SNOW THROUGH THE EARLY MORNING HOURS WILL BE ALONG A ROUGHLY MSP-MKE CORRIDOR...WITH GENERALLY LIGHT AMOUNTS OF AN INCH OR LESS EXPECTED ACROSS FAR NORTHEAST IL AND PARTS OF NORTHERN IN. FORECAST SOUNDINGS INDICATE DRY AIR ARRIVING IN MID-LEVELS BY MID-LATE MORNING AND LIMITING BEST FORCING FOR SNOW TO A ONLY A FEW HOURS THIS AM. SURFACE TROUGH PASSES MID-DAY...WITH RENEWED COLD ADVECTION AND EXTENSIVE UPSTREAM CLOUDINESS SUPPORTING SCATTERED FLURRIES THIS AFTERNOON AS LOW-LEVEL THERMAL PROFILES COOL AGAIN. MOISTURE BECOMES VERY SHALLOW TONIGHT AND THURSDAY...DECREASING POTENTIAL FOR FLURRIES DESPITE ANOTHER DIGGING SHORT WAVE ACROSS THE WESTERN LAKES. THE MAIN LARGE-SCALE UPPER TROUGH AXIS THEN SHIFTS EAST THURSDAY NIGHT...ALLOWING SURFACE HIGH PRESSURE TO SPREAD EAST ACROSS THE AREA BY FRIDAY MORNING. TEMPERATURES WERE RISING INTO THE 20S WITH THE SOUTH WINDS THIS MORNING...WITH HIGHS EXPECTED TO TOP OUT IN THE MID 20S TO LOW 30S TODAY WITH THE MILDEST TEMPS ACROSS THE FAR EAST/SOUTHEAST CWA. COLDER TEMPS AGAIN TONIGHT AND THURSDAY...WITH THE COLDEST EXPECTED EARLY FRIDAY MORNING IN THE VICINITY OF THE SURFACE RIDGE AXIS. LOWS IN THE SINGLE DIGITS TO LOWER TEENS ARE LIKELY FRIDAY MORNING WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. MUCH-TOUTED CHANGE IN THE UPPER PATTERN WILL BE UNDERWAY FRIDAY... AS FLOW DE-AMPLIFIES AND UPPER TROUGH MOVES ACROSS THE SOUTHWESTERN STATES AND ACROSS THE CENTRAL AND SOUTHERN ROCKIES FRIDAY NIGHT. ALONG WITH A DISTURBANCE MOVING ACROSS CENTRAL CANADA...THIS WILL SET UP SOUTHERLY RETURN FLOW INTO THE REGION FRIDAY NIGHT WITH ASSOCIATED WARM/MOIST ADVECTION. MODELS CONTINUE TO INDICATE DEVELOPMENT OF SOME LIGHT PRECIP OVERNIGHT...WITH FORECAST SOUNDINGS INDICATING ELEVATED WARM LAYER TEMPS APPROACHING +5C WHILE SFC TEMPS ARE BELOW FREEZING. THIS SUPPORTS THE POTENTIAL FOR SOME LIGHT FREEZING RAIN OR SLEET FRIDAY NIGHT...BEFORE WARM ADVECTION EVENTUALLY RAISES SURFACE TEMPS ABOVE FREEZING ON SATURDAY. MODELS HAVE TRENDED A LITTLE SLOWER WITH ARRIVAL OF LIGHT PRECIP...THOUGH ALSO SOMEWHAT COLDER INITIALLY AT THE SURFACE. WILL CONTINUE TO MENTION POTENTIAL FOR FREEZING RAIN/SLEET AND WILL HAVE TO MONITOR TRENDS FOR THE POTENTIAL OF SOME LIGHT ICE ACCUMULATION LATER FRIDAY NIGHT INTO EARLY SATURDAY. RATZER && .LONG TERM... 335 AM CST SATURDAY THROUGH TUESDAY... LONGER RANGE MODEL SOLUTIONS CONTINUE TO LIFT SOUTHWESTERN TROUGH TOWARD THE AREA OVER THE WEEKEND...WITH LOW LEVELS QUICKLY WARMING ABOVE FREEZING SATURDAY MORNING AND CHANGING ANY MIXED PRECIP OVER TO RAIN. 00Z GFS/ECMWF HAVE COME INTO BETTER AGREEMENT IN TIMING THE NEGATIVELY-TILTED SOUTHWESTERN SHORT WAVE AND DEEPENING SURFACE LOW TO LIFT ACROSS THE FORECAST AREA SUNDAY AFTERNOON/EVENING...WITH TEMPS RISING INTO THE BALMY 45-50 RANGE. SOME DIFFERENCES REMAIN WITH THE DETAILS OF PHASING THIS SYSTEM WITH A NORTHERN STREAM DEVELOPING CLOSED UPPER LOW OVER THE REGION SUNDAY NIGHT INTO MONDAY...THOUGH REASONABLY SIMILAR IN THE IDEA OF MILD WITH RAIN/SHOWERS EVENTUALLY GIVING WAY TO LIGHTER RAIN/SNOW TRANSITION MONDAY-MONDAY NIGHT AND TO LINGERING SNOW SHOWERS TUESDAY AS WE SHIFT BACK TO A DEEP EASTERN CONUS UPPER TROUGH AND COLDER WEATHER EARLY NEXT WEEK. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * LIGHT SNOW SHOWERS MIDDAY INTO EARLY AFTERNOON WITH MVFR CIGS/VSBY. * CIGS TRENDING TO MVFR THIS AFTERNOON. * GUSTY WEST WINDS RETURN LATE THIS MORNING WITH PEAK GUSTS ARND 25-28 KT THIS AFTN. KMD //DISCUSSION...UPDATED 18Z... SNOW SHOWERS IN SOUTHWEST WISCONSIN HAVE A HISTORY OF 2-5SM VISIBILITY FOR A 2-3 HOUR PERIOD AT MOST. THE FORCING ASSOCIATED WITH THIS ACTIVITY COMES THROUGH NORTHERN ILLINOIS MIDDAY INTO EARLY AFTERNOON. IT DOES WEAKEN SOMEWHAT AS IT PROGRESSES SOUTH AND EAST...BUT WE WILL HAVE MORE UNSTABLE LOW LEVELS WHICH WILL SUPPORT SOME LIGHT SNOW SHOWERS. MUCH OF THIS ACTIVITY WILL BE LIGHT AND NON ACCUMULATING WITH NO SIGNFICIANT VSBY REDUCTION...BUT THERE COULD BE A BRIEF DUSTING WITH ANY OF THE HEAVIER SNOW SHOWERS. CIGS TREND BACK TO VFR TONIGHT WITH SOME CLEARING POSSIBLE. WINDS REMAIN WESTERLY THROUGH THE PERIOD...STRONGEST THIS AFTERNOON. KMD //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH IN A PERIOD OF LIGHT AND GENERALLY NON ACCUMULATING SNOW SHOWERS THIS AFTERNOON. MEDIUM ON HOW LONG VISIBLITIES WILL BE REDUCED TO MVFR AND LOW ON WHETHER CIGS WILL DROP BELOW 2000 FT. * HIGH FOR PERIODS OF MVFR CIGS THIS AFTERNOON. * HIGH FOR WIND TRENDS. KMD //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...CHANCE OF A WINTRY MIX OVERNIGHT. IFR LIKELY OVERNIGHT. SATURDAY...WINTRY MIX BCMG RAIN. IFR LIKELY. SUNDAY...RAIN AND IFR LIKELY. MONDAY...CHC -RASN BCMG -SN. MVFR TO IFR CIGS. TUESDAY...VFR. JEE && .MARINE... 134 PM CST A VERY ACTIVE PATTERN CONTINUES FOR LAKE MICHIGAN. HAVE MADE NO CHANGES TO THE GOING GALE WARNING OR SMALL CRAFT ADVISORY AS FORECAST CONDITIONS REMAIN ON TRACK. A SURFACE TROUGH CROSSING LAKE MICHIGAN TODAY HAD BROUGHT A BRIEF LULL TO THE WINDS EARLIER TODAY...BUT FOLLOWING THE PASSAGE OF THIS TROUGH...WINDS HAVE SHIFTED FROM SWLY TO WLY EARLY THIS AFTERNOON AND ARE RAMPING BACK UP TO PREVAILING WEST GALES. A SERIES OF MID LEVEL IMPULSES ROTATING AROUND THE PERIPHERY OF A DEEP UPPER LOW CENTERED OVER THE HUDSON BAY AREA WILL CONTINUE THE INFLUX OF UNSEASONABLY COLD AIR INTO THE GREAT LAKES REGION. THESE IMPULSES WILL ALLOW SURFACE LOW PRESSURE TO DEEPEN OVER THE UPPER GREAT LAKES TONIGHT AS HIGH PRESSURE BUILDS ACROSS THE CENTRAL PLAINS. THE SFC LOW WILL CONTINUE TO LIFT OUT TO THE NORTHEAST THROUGH ERN QUEBEC AND INTO NOVA SCOTIA THURSDAY AND THURSDAY NIGHT AS THE HIGH PRESSURE BUILDS ACROSS THE MIDDLE MISSISSIPPI VALLEY. THE PRESSURE GRADIENT OVER THE LAKE WILL GRADUALLY WEAKEN ...BUT WITH THE CENTER OF THE HIGH SLIDING SOUTH OF THE LAKE...BRISK WEST TO NORTHWEST WINDS WILL PERSIST THROUGH THURSDAY...THOUGH WITH A WEAKENING GRADIENT...WINDS SHOULD DROP BELOW GALE FORCE BY LATE THURSDAY MORNING. THE RIDGE AXIS SHOULD CROSS THE LAKE THURSDAY NIGHT AND FRIDAY MORNING...ALLOWING WINDS TO DECREASE FURTHER...AND ANTICIPATE THAT THE SMALL CRAFT ADVISORY CONDITIONS FOR THE NEARSHORE WATERS SHOULD STILL COME TO THE END DURING THE DAY ON FRIDAY...AS RESIDUAL WAVE ACTION SUBSIDES...THOUGH THE ADVISORY CRITERIA WAVES SHOULD OUTLAST THE ADVISORY CRITERIA WINDS. THE PERIOD FOR THE POTENTIAL FOR HAZARDOUS CONDITIONS OVER THE LAKE WILL BE RELATIVELY BRIEF. AS THE SFC HIGH MOVES OFF THE SOUTH ATLANTIC COAST OVER THE WEEKEND...A TROUGH OF LOW PRESSURE WILL DEVELOP OVER THE WESTERN PLAINS...SETTING UP STRENGTHENING...MORE SOUTHERLY WINDS SATURDAY NIGHT AND SUNDAY. BY EARLY NEXT WEEK...THE LONGER RANGE MODELS ARE INDICATING THAT TWO LOW PRESSURE SYSTEM WILL EVENTUALLY DEVELOP...ONE OVER THE SOUTHERN CANADIAN PRAIRIES AND ANOTHER OVER THE RED RIVER VALLEY. THE FORECAST MODELS ARE SHOWING THAT THE TWO SYSTEM SHOULD EVENTUALLY MERGE SOMEWHERE OVER THE UPPER MIDWEST AND DEEPEN OVER THE GREAT LAKES REGION...POSSIBLY BRINGING ANOTHER PERIOD OVER GALES TO THE LAKE...POSSIBLY AS EARLY AS MONDAY AND THEN CONTINUING THROUGH THE MIDDLE OF NEXT WEEK. HOWEVER THERE IS SOME DISAGREEMENT AMONG THE MODELS AS THE EXACTLY WHERE THE CONSOLIDATED LOW WILL DEVELOP AND HOW DEEP IT WILL BECOME...SO WILL GO WITH A RELATIVELY CONSERVATIVE FORECAST FOR NOW...BUT ANTICIPATE THAT THE FORECAST WINDS IN THE LATTER PORTIONS OF THE PERIOD WILL INCREASE WITH LATER UPDATES. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1148 AM CST WED NOV 19 2014 .SHORT TERM... 335 AM CST TODAY THROUGH FRIDAY... MAIN FOCUS IN NEAR TERM IS WITH CLIPPER-TYPE SYSTEM MOVING THROUGH THE REGION THIS MORNING...AND THE POTENTIAL FOR SOME LIGHT ACCUMULATING SNOW MAINLY ACROSS FAR NORTHERN/NORTHEAST IL. OTHER HIGHLIGHTS...OR LOW LIGHTS AS THE CASE MAY BE...THROUGH FRIDAY ARE CONTINUED SUB-NORMAL CHILLY TEMPERATURES AND THE POTENTIAL FOR SOME LIGHT FREEZING RAIN FRIDAY NIGHT INTO EARLY SATURDAY MORNING AHEAD OF A SYSTEM WHICH WILL BRING RAIN AND WARMER WEATHER OVER THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY DEPICTS A SHORT-WAVE DIGGING SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY AND APPROACHING WI/IL AT 0830Z. SURFACE TROUGH REFLECTION WAS OVER SOUTHERN MN/EAST CENTRAL IA...WITH FAIRLY IMPRESSIVE SURFACE PRESSURE FALLS SPREADING INTO SOUTHERN WI/IL AND BACKING WINDS TO THE SOUTH AND RAISING TEMPS. RADAR RETURNS FROM MID-LEVEL CLOUDS HAVE DEVELOPED SOUTHEAST FROM TWIN CITIES AREA...THOUGH DRY LOW LEVEL AIR SO FAR HAS SLOWED DEVELOPMENT OF SNOW AT THE SURFACE. TRACK OF SYSTEM...RADAR TRENDS AND HIGH-RES HRRR GUIDANCE ALL INDICATE BEST POTENTIAL FOR MEASURABLE SNOW THROUGH THE EARLY MORNING HOURS WILL BE ALONG A ROUGHLY MSP-MKE CORRIDOR...WITH GENERALLY LIGHT AMOUNTS OF AN INCH OR LESS EXPECTED ACROSS FAR NORTHEAST IL AND PARTS OF NORTHERN IN. FORECAST SOUNDINGS INDICATE DRY AIR ARRIVING IN MID-LEVELS BY MID-LATE MORNING AND LIMITING BEST FORCING FOR SNOW TO A ONLY A FEW HOURS THIS AM. SURFACE TROUGH PASSES MID-DAY...WITH RENEWED COLD ADVECTION AND EXTENSIVE UPSTREAM CLOUDINESS SUPPORTING SCATTERED FLURRIES THIS AFTERNOON AS LOW-LEVEL THERMAL PROFILES COOL AGAIN. MOISTURE BECOMES VERY SHALLOW TONIGHT AND THURSDAY...DECREASING POTENTIAL FOR FLURRIES DESPITE ANOTHER DIGGING SHORT WAVE ACROSS THE WESTERN LAKES. THE MAIN LARGE-SCALE UPPER TROUGH AXIS THEN SHIFTS EAST THURSDAY NIGHT...ALLOWING SURFACE HIGH PRESSURE TO SPREAD EAST ACROSS THE AREA BY FRIDAY MORNING. TEMPERATURES WERE RISING INTO THE 20S WITH THE SOUTH WINDS THIS MORNING...WITH HIGHS EXPECTED TO TOP OUT IN THE MID 20S TO LOW 30S TODAY WITH THE MILDEST TEMPS ACROSS THE FAR EAST/SOUTHEAST CWA. COLDER TEMPS AGAIN TONIGHT AND THURSDAY...WITH THE COLDEST EXPECTED EARLY FRIDAY MORNING IN THE VICINITY OF THE SURFACE RIDGE AXIS. LOWS IN THE SINGLE DIGITS TO LOWER TEENS ARE LIKELY FRIDAY MORNING WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. MUCH-TOUTED CHANGE IN THE UPPER PATTERN WILL BE UNDERWAY FRIDAY... AS FLOW DE-AMPLIFIES AND UPPER TROUGH MOVES ACROSS THE SOUTHWESTERN STATES AND ACROSS THE CENTRAL AND SOUTHERN ROCKIES FRIDAY NIGHT. ALONG WITH A DISTURBANCE MOVING ACROSS CENTRAL CANADA...THIS WILL SET UP SOUTHERLY RETURN FLOW INTO THE REGION FRIDAY NIGHT WITH ASSOCIATED WARM/MOIST ADVECTION. MODELS CONTINUE TO INDICATE DEVELOPMENT OF SOME LIGHT PRECIP OVERNIGHT...WITH FORECAST SOUNDINGS INDICATING ELEVATED WARM LAYER TEMPS APPROACHING +5C WHILE SFC TEMPS ARE BELOW FREEZING. THIS SUPPORTS THE POTENTIAL FOR SOME LIGHT FREEZING RAIN OR SLEET FRIDAY NIGHT...BEFORE WARM ADVECTION EVENTUALLY RAISES SURFACE TEMPS ABOVE FREEZING ON SATURDAY. MODELS HAVE TRENDED A LITTLE SLOWER WITH ARRIVAL OF LIGHT PRECIP...THOUGH ALSO SOMEWHAT COLDER INITIALLY AT THE SURFACE. WILL CONTINUE TO MENTION POTENTIAL FOR FREEZING RAIN/SLEET AND WILL HAVE TO MONITOR TRENDS FOR THE POTENTIAL OF SOME LIGHT ICE ACCUMULATION LATER FRIDAY NIGHT INTO EARLY SATURDAY. RATZER && .LONG TERM... 335 AM CST SATURDAY THROUGH TUESDAY... LONGER RANGE MODEL SOLUTIONS CONTINUE TO LIFT SOUTHWESTERN TROUGH TOWARD THE AREA OVER THE WEEKEND...WITH LOW LEVELS QUICKLY WARMING ABOVE FREEZING SATURDAY MORNING AND CHANGING ANY MIXED PRECIP OVER TO RAIN. 00Z GFS/ECMWF HAVE COME INTO BETTER AGREEMENT IN TIMING THE NEGATIVELY-TILTED SOUTHWESTERN SHORT WAVE AND DEEPENING SURFACE LOW TO LIFT ACROSS THE FORECAST AREA SUNDAY AFTERNOON/EVENING...WITH TEMPS RISING INTO THE BALMY 45-50 RANGE. SOME DIFFERENCES REMAIN WITH THE DETAILS OF PHASING THIS SYSTEM WITH A NORTHERN STREAM DEVELOPING CLOSED UPPER LOW OVER THE REGION SUNDAY NIGHT INTO MONDAY...THOUGH REASONABLY SIMILAR IN THE IDEA OF MILD WITH RAIN/SHOWERS EVENTUALLY GIVING WAY TO LIGHTER RAIN/SNOW TRANSITION MONDAY-MONDAY NIGHT AND TO LINGERING SNOW SHOWERS TUESDAY AS WE SHIFT BACK TO A DEEP EASTERN CONUS UPPER TROUGH AND COLDER WEATHER EARLY NEXT WEEK. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * LIGHT SNOW SHOWERS MIDDAY INTO EARLY AFTERNOON WITH MVFR CIGS/VSBY. * CIGS TRENDING TO MVFR THIS AFTERNOON. * GUSTY WEST WINDS RETURN LATE THIS MORNING WITH PEAK GUSTS ARND 25-28 KT THIS AFTN. KMD //DISCUSSION...UPDATED 18Z... SNOW SHOWERS IN SOUTHWEST WISCONSIN HAVE A HISTORY OF 2-5SM VISIBILITY FOR A 2-3 HOUR PERIOD AT MOST. THE FORCING ASSOCIATED WITH THIS ACTIVITY COMES THROUGH NORTHERN ILLINOIS MIDDAY INTO EARLY AFTERNOON. IT DOES WEAKEN SOMEWHAT AS IT PROGRESSES SOUTH AND EAST...BUT WE WILL HAVE MORE UNSTABLE LOW LEVELS WHICH WILL SUPPORT SOME LIGHT SNOW SHOWERS. MUCH OF THIS ACTIVITY WILL BE LIGHT AND NON ACCUMULATING WITH NO SIGNFICIANT VSBY REDUCTION...BUT THERE COULD BE A BRIEF DUSTING WITH ANY OF THE HEAVIER SNOW SHOWERS. CIGS TREND BACK TO VFR TONIGHT WITH SOME CLEARING POSSIBLE. WINDS REMAIN WESTERLY THROUGH THE PERIOD...STRONGEST THIS AFTERNOON. KMD //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH IN A PERIOD OF LIGHT AND GENERALLY NON ACCUMULATING SNOW SHOWERS THIS AFTERNOON. MEDIUM ON HOW LONG VISIBLITIES WILL BE REDUCED TO MVFR AND LOW ON WHETHER CIGS WILL DROP BELOW 2000 FT. * HIGH FOR PERIODS OF MVFR CIGS THIS AFTERNOON. * HIGH FOR WIND TRENDS. KMD //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...CHANCE OF A WINTRY MIX OVERNIGHT. IFR LIKELY OVERNIGHT. SATURDAY...WINTRY MIX BCMG RAIN. IFR LIKELY. SUNDAY...RAIN AND IFR LIKELY. MONDAY...CHC -RASN BCMG -SN. MVFR TO IFR CIGS. TUESDAY...VFR. JEE && .MARINE... 210 AM CST HEADLINES...DID NOT MAKE ANY CHANGES TO THE SMALL CRAFT ADVISORY BUT DID UPGRADE THE OPEN WATER GALE WATCH TO A WARNING. MAY SEE WINDS DIMINISH TO BELOW GALES FASTER THAN THE WARNING WOULD INDICATE...BUT HAVE LIMITED CONFIDENCE IN HOW LONG GALES WILL LAST SO LEFT THE END TIME AS IS. A TROUGH OF LOW PRESSURE MOVES OVER THE LAKE THIS AFTERNOON WITH WEST WINDS BECOMING SOUTH OVER THE NEXT FEW HOURS. WINDS RETURN TO WEST BEHIND THE TROUGH THIS AFTERNOON AND INCREASE TO GALES BY THE LATE AFTERNOON. GALES CONTINUE OVERNIGHT INTO THURSDAY MORNING...BUT THEY MAY COME DOWN BELOW GALE FORCE SOONER THAN THE WARNING INDICATES. NW WINDS TO 30 KT BECOME WEST 10-20 KT BY FRIDAY MORNING. HIGH PRESSURE PASSES SOUTH OF THE LAKE LATE THURSDAY NIGHT AND FRIDAY MORNING WITH LIGHT WINDS BECOMING SOUTH TO SOUTHWEST TO 20 KT BY FRIDAY EVENING. WINDS INCREASE TO 30 KT FRIDAY NIGHT AS THE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A LOW OVER NORTHERN QUEBEC. SOUTH WINDS PERSIST THROUGH SATURDAY NIGHT BEFORE BECOMING SOUTHEAST SUNDAY AHEAD OF THE NEXT LOW. GUIDANCE DIFFERS ON STRONG THE LOW WILL BE AND ITS EXACT PATH BUT GUIDANCE MEMBERS DO AGREE THAT THE LAKE WILL MOVE OVER THE LAKE AT SOME POINT SUNDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM WEDNESDAY TO 9 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1007 AM CST WED NOV 19 2014 .SHORT TERM... 335 AM CST TODAY THROUGH FRIDAY... MAIN FOCUS IN NEAR TERM IS WITH CLIPPER-TYPE SYSTEM MOVING THROUGH THE REGION THIS MORNING...AND THE POTENTIAL FOR SOME LIGHT ACCUMULATING SNOW MAINLY ACROSS FAR NORTHERN/NORTHEAST IL. OTHER HIGHLIGHTS...OR LOW LIGHTS AS THE CASE MAY BE...THROUGH FRIDAY ARE CONTINUED SUB-NORMAL CHILLY TEMPERATURES AND THE POTENTIAL FOR SOME LIGHT FREEZING RAIN FRIDAY NIGHT INTO EARLY SATURDAY MORNING AHEAD OF A SYSTEM WHICH WILL BRING RAIN AND WARMER WEATHER OVER THE WEEKEND. EARLY MORNING WATER VAPOR IMAGERY DEPICTS A SHORT-WAVE DIGGING SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY AND APPROACHING WI/IL AT 0830Z. SURFACE TROUGH REFLECTION WAS OVER SOUTHERN MN/EAST CENTRAL IA...WITH FAIRLY IMPRESSIVE SURFACE PRESSURE FALLS SPREADING INTO SOUTHERN WI/IL AND BACKING WINDS TO THE SOUTH AND RAISING TEMPS. RADAR RETURNS FROM MID-LEVEL CLOUDS HAVE DEVELOPED SOUTHEAST FROM TWIN CITIES AREA...THOUGH DRY LOW LEVEL AIR SO FAR HAS SLOWED DEVELOPMENT OF SNOW AT THE SURFACE. TRACK OF SYSTEM...RADAR TRENDS AND HIGH-RES HRRR GUIDANCE ALL INDICATE BEST POTENTIAL FOR MEASURABLE SNOW THROUGH THE EARLY MORNING HOURS WILL BE ALONG A ROUGHLY MSP-MKE CORRIDOR...WITH GENERALLY LIGHT AMOUNTS OF AN INCH OR LESS EXPECTED ACROSS FAR NORTHEAST IL AND PARTS OF NORTHERN IN. FORECAST SOUNDINGS INDICATE DRY AIR ARRIVING IN MID-LEVELS BY MID-LATE MORNING AND LIMITING BEST FORCING FOR SNOW TO A ONLY A FEW HOURS THIS AM. SURFACE TROUGH PASSES MID-DAY...WITH RENEWED COLD ADVECTION AND EXTENSIVE UPSTREAM CLOUDINESS SUPPORTING SCATTERED FLURRIES THIS AFTERNOON AS LOW-LEVEL THERMAL PROFILES COOL AGAIN. MOISTURE BECOMES VERY SHALLOW TONIGHT AND THURSDAY...DECREASING POTENTIAL FOR FLURRIES DESPITE ANOTHER DIGGING SHORT WAVE ACROSS THE WESTERN LAKES. THE MAIN LARGE-SCALE UPPER TROUGH AXIS THEN SHIFTS EAST THURSDAY NIGHT...ALLOWING SURFACE HIGH PRESSURE TO SPREAD EAST ACROSS THE AREA BY FRIDAY MORNING. TEMPERATURES WERE RISING INTO THE 20S WITH THE SOUTH WINDS THIS MORNING...WITH HIGHS EXPECTED TO TOP OUT IN THE MID 20S TO LOW 30S TODAY WITH THE MILDEST TEMPS ACROSS THE FAR EAST/SOUTHEAST CWA. COLDER TEMPS AGAIN TONIGHT AND THURSDAY...WITH THE COLDEST EXPECTED EARLY FRIDAY MORNING IN THE VICINITY OF THE SURFACE RIDGE AXIS. LOWS IN THE SINGLE DIGITS TO LOWER TEENS ARE LIKELY FRIDAY MORNING WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. MUCH-TOUTED CHANGE IN THE UPPER PATTERN WILL BE UNDERWAY FRIDAY... AS FLOW DE-AMPLIFIES AND UPPER TROUGH MOVES ACROSS THE SOUTHWESTERN STATES AND ACROSS THE CENTRAL AND SOUTHERN ROCKIES FRIDAY NIGHT. ALONG WITH A DISTURBANCE MOVING ACROSS CENTRAL CANADA...THIS WILL SET UP SOUTHERLY RETURN FLOW INTO THE REGION FRIDAY NIGHT WITH ASSOCIATED WARM/MOIST ADVECTION. MODELS CONTINUE TO INDICATE DEVELOPMENT OF SOME LIGHT PRECIP OVERNIGHT...WITH FORECAST SOUNDINGS INDICATING ELEVATED WARM LAYER TEMPS APPROACHING +5C WHILE SFC TEMPS ARE BELOW FREEZING. THIS SUPPORTS THE POTENTIAL FOR SOME LIGHT FREEZING RAIN OR SLEET FRIDAY NIGHT...BEFORE WARM ADVECTION EVENTUALLY RAISES SURFACE TEMPS ABOVE FREEZING ON SATURDAY. MODELS HAVE TRENDED A LITTLE SLOWER WITH ARRIVAL OF LIGHT PRECIP...THOUGH ALSO SOMEWHAT COLDER INITIALLY AT THE SURFACE. WILL CONTINUE TO MENTION POTENTIAL FOR FREEZING RAIN/SLEET AND WILL HAVE TO MONITOR TRENDS FOR THE POTENTIAL OF SOME LIGHT ICE ACCUMULATION LATER FRIDAY NIGHT INTO EARLY SATURDAY. RATZER && .LONG TERM... 335 AM CST SATURDAY THROUGH TUESDAY... LONGER RANGE MODEL SOLUTIONS CONTINUE TO LIFT SOUTHWESTERN TROUGH TOWARD THE AREA OVER THE WEEKEND...WITH LOW LEVELS QUICKLY WARMING ABOVE FREEZING SATURDAY MORNING AND CHANGING ANY MIXED PRECIP OVER TO RAIN. 00Z GFS/ECMWF HAVE COME INTO BETTER AGREEMENT IN TIMING THE NEGATIVELY-TILTED SOUTHWESTERN SHORT WAVE AND DEEPENING SURFACE LOW TO LIFT ACROSS THE FORECAST AREA SUNDAY AFTERNOON/EVENING...WITH TEMPS RISING INTO THE BALMY 45-50 RANGE. SOME DIFFERENCES REMAIN WITH THE DETAILS OF PHASING THIS SYSTEM WITH A NORTHERN STREAM DEVELOPING CLOSED UPPER LOW OVER THE REGION SUNDAY NIGHT INTO MONDAY...THOUGH REASONABLY SIMILAR IN THE IDEA OF MILD WITH RAIN/SHOWERS EVENTUALLY GIVING WAY TO LIGHTER RAIN/SNOW TRANSITION MONDAY-MONDAY NIGHT AND TO LINGERING SNOW SHOWERS TUESDAY AS WE SHIFT BACK TO A DEEP EASTERN CONUS UPPER TROUGH AND COLDER WEATHER EARLY NEXT WEEK. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * LIGHT SNOW SHOWERS MIDDAY INTO EARLY AFTERNOON WITH MVFR CIGS/VSBY. * CIGS TRENDING TO MVFR THIS AFTERNOON. * GUSTY WEST WINDS RETURN LATE THIS MORNING WITH PEAK GUSTS ARND 25-28 KT THIS AFTN. KMD //DISCUSSION...UPDATED 14Z... MORNING SNOW SHOULD LARGELY REMAIN VFR WITH MODERATE SNOWS CONFINED TO FAR NORTHEAST ILLINOIS. THERE IS A BAND OF SNOW SHOWERS BACK IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA THAT HAS A HISTORY OF 3-5SM VISIBILITY FOR A 2-3 HOUR PERIOD. THE FORCING ASSOCIATED WITH THIS ACTIVITY COMES THROUGH NORTHERN ILLINOIS MIDDAY INTO EARLY AFTERNOON. IT DOES WEAKEN SOMEWHAT AS IT PROGRESSES SOUTH AND EAST...BUT WE WILL HAVE MORE UNSTABLE LOW LEVELS WHICH WILL SUPPORT SOME LIGHT SNOW SHOWERS. HAVE ATTEMPTED TO TIME THESE IN FOR THE MOST LIKELY PERIOD OF LOWER MVFR CONDITIONS. KMD PREVIOUS DISCUSSION FROM 12Z... RADAR SHOWS DECENT REFLECTIVY ACROSS NORTHERN IL AND NW INDIANA BUT DRY LOW LEVELS ARE IMPEDING SNOW FROM REACHING THE SURFACE. AS SUCH BACKED OF SNOW FOR THIS MORNING AND EXPECTING MOSTLY FLURRIES THROUGH THE EARLY AFTERNOON. MAY SEE A BRIEF HEAVIER SNOW SHOWER THAT BRINGS DOWN VSBY AND CIGS...BUT NOT OVERLY CONFIDENT. OUTSIDE OF THE HEAVIER SNOW...CIGS AND VSBY WILL BE VFR. SSE WINDS BCM WEST BY MID MORNING AND GUST TO ARND 25 KT THIS AFTN. GUSTY CONDITIONS REMAIN OVERNIGHT WITH GUSTS SLOWLY DIMINISHING OVERNIGHT. JEE //ORD AND MDW CONFIDENCE...UPDATED 14Z... * HIGH CONFIDENCE IN WINDS AND CIG FCST. * HIGH CONFIDENCE IN A PERIOD OF SNOW SHOWERS WITH MVFR VSBY ...MEDIUM-HIGH ON TIMING. * HIGH FOR PERIODS OF MVFR CIGS THIS AFTERNOON. KMD //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...CHANCE OF A WINTRY MIX OVERNIGHT. IFR LIKELY OVERNIGHT. SATURDAY...WINTRY MIX BCMG RAIN. IFR LIKELY. SUNDAY...RAIN AND IFR LIKELY. MONDAY...CHC -RASN BCMG -SN. MVFR TO IFR CIGS. TUESDAY...VFR. JEE && .MARINE... 210 AM CST HEADLINES...DID NOT MAKE ANY CHANGES TO THE SMALL CRAFT ADVISORY BUT DID UPGRADE THE OPEN WATER GALE WATCH TO A WARNING. MAY SEE WINDS DIMINISH TO BELOW GALES FASTER THAN THE WARNING WOULD INDICATE...BUT HAVE LIMITED CONFIDENCE IN HOW LONG GALES WILL LAST SO LEFT THE END TIME AS IS. A TROUGH OF LOW PRESSURE MOVES OVER THE LAKE THIS AFTERNOON WITH WEST WINDS BECOMING SOUTH OVER THE NEXT FEW HOURS. WINDS RETURN TO WEST BEHIND THE TROUGH THIS AFTERNOON AND INCREASE TO GALES BY THE LATE AFTERNOON. GALES CONTINUE OVERNIGHT INTO THURSDAY MORNING...BUT THEY MAY COME DOWN BELOW GALE FORCE SOONER THAN THE WARNING INDICATES. NW WINDS TO 30 KT BECOME WEST 10-20 KT BY FRIDAY MORNING. HIGH PRESSURE PASSES SOUTH OF THE LAKE LATE THURSDAY NIGHT AND FRIDAY MORNING WITH LIGHT WINDS BECOMING SOUTH TO SOUTHWEST TO 20 KT BY FRIDAY EVENING. WINDS INCREASE TO 30 KT FRIDAY NIGHT AS THE GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A LOW OVER NORTHERN QUEBEC. SOUTH WINDS PERSIST THROUGH SATURDAY NIGHT BEFORE BECOMING SOUTHEAST SUNDAY AHEAD OF THE NEXT LOW. GUIDANCE DIFFERS ON STRONG THE LOW WILL BE AND ITS EXACT PATH BUT GUIDANCE MEMBERS DO AGREE THAT THE LAKE WILL MOVE OVER THE LAKE AT SOME POINT SUNDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM WEDNESDAY TO 9 AM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1009 AM MST WED NOV 19 2014 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 218 AM MST WED NOV 19 2014 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS INDICATE LARGE SCALE TROUGHING ACROSS THE EASTERN UNITED STATES WITH AN AMPLIFIED RIDGE UPSTREAM ACROSS THE PACIFIC US COAST. BETWEEN THESE FEATURES NORTH-NORTHWEST FLOW IS IN PLACE FROM THE NORTHERN PLAINS TO SOUTHERN PLAINS. AT THE THE SURFACE ARCTIC COLD FRONT IS APPROXIMATELY ALONG THE SD/NE STATE LINE WITH A SURFACE LOW OVER NORTHCENTRAL COLORADO. SURFACE HIGH PRESSURE IS CURRENTLY IN PLACE OVER OUR CWA. UPPER LEVEL STORM TRACK IS SPLIT AROUND OUR CWA THROUGH THE END OF THE WEEK SO FORECAST CONDITIONS SHOULD REMAIN DRY DURING THESE PERIODS. AS OF 00Z GUIDANCE...NAM SNOW DEPTH CONTINUED TO BE UNREFLECTIVE OF CURRENT SNOW FIELD AND HOLDS THIS SNOW FIELD IN PLACE THROUGH THIS WEEKEND. AS A RESULT BL CONDITIONS AND SURFACE TEMPS FROM THE NAM WERE NOT USED IN CURRENT FORECAST...THOUGH LARGER SCALE FIELDS WERE TAKEN INTO CONSIDERATION. RAP/HRRR SNOW FIELDS WERE MORE REFLECTIVE OF REALITY...SO THESE MODELS WERE USED THROUGH THE NEXT 24 HR FOR ADJUSTING SHORT RANGE BL TRENDS. TODAY-TONIGHT...ARCTIC FRONT MOVES FROM NORTHERN PLAINS TOWARDS CENTRAL MISSISSIPPI RIVER VALLEY BY MIDDAY TODAY. WHILE COLDEST AIR MASS REMAINS NORTH AND EAST...THIS FRONT WILL LEAD TO A DECREASE IN TEMPS ALOFT OVER OUR CWA. LEE TROUGH REDEVELOPING THIS AFTERNOON WILL HELP BRING RETURN FLOW INTO MOST OF OUR CWA...SO WE SHOULD MANAGE TO WARM TO SEASONAL NORMALS IN THE UPPER 40S TO AROUND 50 FOR MOST LOCATIONS. THURSDAY-FRIDAY NIGHT...SHORTWAVE RIDGE QUICKLY SHIFTS EAST WITH SHORTWAVE TROUGHS SPLITTING AROUND OUR CWA DURING THESE PERIODS. AS THIS PATTERN EVOLVES TEMPS ALOFT WILL GENERALLY SUPPORT SEASONAL HIGHS IN THE UPPER 40S/LOWER 50S. AS THE SOUTHERN STREAM UPPER LOW AND SURFACE LOW TRANSITION ACROSS THE SOUTHERN PLAINS...EASTERLY TO SOUTHEAST FLOW WILL BRING INCREASING LOW LEVEL MOISTURE ACROSS WESTERN KS/SW NEBRASKA. GFS/SREF ARE SHOWING A SHALLOW SATURATED LAYER DEVELOPING THURSDAY NIGHT. THERE IS WEAK LIFT WITHIN THIS LAYER...HOWEVER DUE TO THE LIMITED DEPTH OF THIS LAYER CONFIDENCE IS HIGHER IN A FREEZING FOG/STRATUS EVENT RATHER THAN FREEZING DRIZZLE THURSDAY NIGHT/FRIDAY MORNING. I COULD NOT RULE OUT A FEW POCKETS OF FREEZING DRIZZLE THOUGH. AS LEE TROUGH REDEVELOPS FRIDAY...DRY AIR ADVECTING IN FROM THE WEST SHOULD HELP ERODE ANY FOG/STRATUS. I AM CONCERNED THAT STRATUS MAY HOLD ON IN OUR EAST AND LIMIT DIURNAL WARMING...BUT AT THIS POINT I DO NOT HAVE ENOUGH CONFIDENCE TO UNDERCUT CONSENSUS IN OUR EAST BY MORE THAN A FEW DEGREES. GFS STILL SHOWS LOW LEVEL MOISTURE POOLING ACROSS OUR EAST FRIDAY NIGHT IN OUR FAR EASTERN CWA...SO FREEZING FOG MAY REDEVELOP. ANY FOG SHOULD BE QUICKLY TRENDING EAST WITH WEST/SOUTHWEST FLOW MOVING EAST THROUGH FRIDAY NIGHT. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 218 AM MST WED NOV 19 2014 SATURDAY...LOTS OF SUN DURING TIME OF PEAK HEATING BUT AN INCREASE IN MID AND HIGH CLOUDS MOVES INTO FAR EASTERN COLORADO TOWARD THE END OF THE DAY. THESE CLOUDS THEN TRAVERSE THE REST OF THE FORECAST AREA SATURDAY NIGHT. THERE IS SOME WEAK MID LEVEL FORCING WITH THE MOSTLY MID LEVEL CLOUDINESS WHICH COULD PRODUCE A FEW AREAS OF VIRGA BUT WITH RATHER LIMITED MOISTURE IN THE LOWER ATMOSPHERE PRECIPITATION CHANCES ARE PRETTY LOW. SOMETHING TO WATCH. BEHIND THE WAVE THAT MOVES THROUGH SATURDAY NIGHT WILL BE A COLD FRONT AND NORTHWEST WINDS INCREASING INTO THE 15 TO 20 MPH RANGE WITH SOME HIGHER GUSTS FOR MOST OF THE AREA. GFS/ECMWF 850MB TEMPERATURES SUPPORT HIGH TEMPERATURES PRODUCED BY MEX GUIDANCE (UPPER 50S AND LOW 60S) VS THE EXTENDED PROCEDURE WHICH IS PRODUCING LOW TO MID 50S. PER COORDINATION WITH NORTHERN AND EASTERN AND SOUTHERN OFFICES HAVE RAISED TEMPS ABOUT 3-4F AS A START. LOWS IN THE MID 20S TO AROUND 30. SUNDAY...UPPER TROUGH AXIS AND PLENTIFUL CLOUDINESS PASS ACROSS THE AREA DURING THE DAY LEAVING THE AREA UNDER NORTHWEST FLOW AND DECREASING CLOUDINESS OVERNIGHT. IT WILL BE WINDY DURING THE DAY WITH NORTHWEST WINDS AROUND 20 MPH WITH HIGHER GUSTS. DURING THE NIGHT 10 TO 20 MPH. GFS/ECMWF 850MB TEMPERATURES SUPPORT ADVERTISED HIGHS IN THE LOW TO MID 40S IN FAR EASTERN COLORADO...UPPER 40S TO LOW 50S EAST OF THE STATE LINE. LOWS SUNDAY NIGHT IN THE UPPER TEENS IN FAR EASTERN COLORADO TO THE MID 20S IN THE HILL CITY AREA. DESPITE INCREASING MOISTURE IN THE MID AND UPPER LEVELS FINER DETAILS AS TO WHERE IT WILL BE AND TIMING OF THE TROUGH PASSAGE PRECLUDE A PRECIPITATION MENTION AT PRESENT TIME. MONDAY...GFS/ECMWF HAVING A HARDER TIME AGREEING ON LARGE SCALE FEATURES AND POSSIBLY MORE IMPORTANTLY LOWER LEVEL FEATURES. ONE EXAMPLE IS 850MB TEMPERATURES. GFS ABOUT 6-7C WARMER THAN THE ECMWF WHICH MAKES A LARGE DIFFERENCE IN TEMPERATURE FORECAST. NO CHANGES MADE AT THIS POINT AND RAN WITH MID 30S TO LOW 40S IN FAR EASTERN COLORADO WITH LOW 40S EAST OF THE BORDER. VARIABLE CLOUDINESS THROUGH THE PERIOD WITH DRY CONDITIONS EXPECTED. LOWS MONDAY NIGHT TEENS TO LOW 20S. CURRENTLY LOOKING AT WINDY CONDITIONS FROM THE NORTHWEST DURING THE DAY. TUESDAY...MAY SEE MORE CLOUDINESS THEN CURRENTLY ADVERTISED AND ONCE AGAIN ITS CONFINED TO MID AND UPPER LEVELS WHICH IS NOT FAVORABLE FOR PRECIPITATION. NO CHANGES TO TEMPERATURE FORECAST WITH HIGHS IN THE LOW TO MID 40S AND LOWS IN THE MID 20S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1007 AM MST WED NOV 19 2014 AN AREA OF HIGH PRESSURE WILL MOVE ACROSS THE HIGH PLAINS TODAY...WHICH WILL BRING LIGHT WIND SHIFTS AT THE SURFACE THROUGH THE TAF PERIOD. VFR CONDITIONS WILL PREVAIL FOR THE DURATION OF THE PERIOD FOR BOTH TERMINALS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...MK
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1244 PM EST WED NOV 19 2014 .SYNOPSIS... ISSUED AT 340 AM EST WED NOV 19 2014 LOW PRESSURE PASSING ACROSS THE NORTHERN LAKES WILL BRING ANOTHER ROUND OF LAKE EFFECT SNOW...AT TIMES HEAVY...THROUGH THURSDAY. TEMPERATURES WILL TURN MILDER DURING THE UPCOMING WEEKEND... SETTING THE STAGE FOR SOME RAIN...ESPECIALLY BY SUNDAY AND SUNDAY NIGHT. && .UPDATE... ISSUED AT 1148 AM EST WED NOV 19 2014 14Z SURFACE ANALYSIS SHOWS A WEAK 1006MB LOW OVER NORTHERN WISCONSIN WITH A TRAILING COLD FRONT INTO ILLINOIS/CENTRAL MISSOURI. COMBINATION OF WARM ADVECTION AND LOW/MID LEVEL TROUGHING PUSHING AN AREA OF MOSTLY LIGHT SNOW ACROSS MICHIGAN...WITH ENHANCED RADAR RETURNS OVER LAKE MICHIGAN WITH SOME DECENT LAKE INDUCED INSTABILITY AND STRONG MID LEVEL CONVERGENCE HELPING FORCE A CONVECTIVE COMPONENT. UPSTREAM COLD FRONT MAKING STEADY PROGRESS EAST WITH A BROAD AREA OF 2-3MB/3H PRESSURE FALLS OUT AHEAD OF IT...EXPECTING FRONT TO PUSH IN TO WESTERN LOWER IN THE 18Z-19Z TIME FRAME. AS IT DOES...EXPECT HEAVIER SNOW SQUALL OVER LAKE MICHIGAN TO GET PUSHED INLAND ALONG THE US-31 CORRIDOR. ALSO EXPECT TO SEE NARROWER LAKE CONVECTION OVER THE FAR NORTHERN PART OF THE LAKE TO EXPAND AS LOW LEVEL CONVERGENCE STRENGTHENS...FOCUSING SNOWFALL INTO WESTER MACKINAC COUNTY. SO "TODAY" ADVISORIES WILL REMAIN AS IT. REMAINDER OF THE AREA WILL SEE PERIODS OF LIGHT SNOW WITH MINIMAL ACCUMULATIONS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 340 AM EST WED NOV 19 2014 ...MORE SIGNIFICANT LAKE EFFECT SNOW ON THE WAY... HIGH IMPACT WEATHER POTENTIAL: WIDESPREAD MOSTLY LIGHT SYNOPTIC SNOW TODAY WITH LAKE ENHANCEMENT NEAR LAKE MICHIGAN...THEN ANOTHER ROUND OF SIGNIFICANT LAKE EFFECT SNOWFALL DEVELOPING TONIGHT. PATTERN SYNOPSIS/FORECAST: UPSTREAM SHORTWAVE TROUGH OVER THE UPPER MISSISSIPPI VALLEY DRIVING A BAND OF WARM AIR ADVECTION SNOW ACROSS THE UPPER MIDWEST. THIS SHORTWAVE FEATURE WILL SERVE TO RE-INFORCE LONGWAVE TROUGH OVER THE EASTERN CONUS AND USHER IN ANOTHER SURGE OF EARLY SEASON ARCTIC AIR WITH LAKE EFFECT SNOW. PRIMARY FORECAST CONCERNS: NUMEROUS. LAKE ENHANCED SNOW ACCUMULATIONS TODAY NEAR THE LAKE MICHIGAN COAST. THEN QUICK TRANSITION TO WEST-NORTHWEST LAKE EFFECT TONIGHT WITH SIGNIFICANT ACCUMULATIONS POSSIBLE. IN ADDITION...GUSTY WINDS MAY CREATE LOW VISIBILITIES AND TRAVEL PROBLEMS WITHIN HEAVIER SNOWSHOWERS. AFOREMENTIONED WARM ADVECTION LIGHT SNOW WILL DEVELOP ACROSS NORTHERN MICHIGAN TODAY WITH BROAD AREA OF ISENTROPIC ASCENT. THIS IS THE EASIEST PORTION OF THE FORECAST...AS ALL AREAS SHOULD SEE AT LEAST SOME SNOW TODAY. H7 MIXING RATIO/S ONLY AROUND 1 G/KG...SO ONLY LIGHT ACCUMULATIONS ON THE ORDER OF 1-2 INCHES. THE EXCEPTION TO THE LIGHTER SNOWS WILL BE CLOSER TO LAKE MICHIGAN...WHERE INCREASING SYNOPTIC FORCING COMBINED WITH PLENTY OF OVER-LAKE INSTABILITY /DELTA T/S IN THE MID-UPPER TEENS/ WILL RESULT IN ENHANCED SNOWFALL. SOME QUESTION MARKS AS TO HOW THE LOW LEVEL FLOW WILL EVOLVE WITH SURFACE LOW OVER NORTHERN LAKE MICHIGAN. WILL LEAN TOWARD HIGH RESOLUTION HRRR FOR LOW LEVEL PATTERN EVOLUTION INTO EARLY THIS AFTERNOON. IMPRESSIVE LOW LEVEL CONVERGENCE SIGNATURE WITH 0-2KM CAPE OF 100 J/KG UP THE SPINE OF LAKE MICHIGAN THIS MORNING WILL BE DRIVEN INLAND TOWARD MANISTEE/BENZIE/LEELANAU COUNTIES AS COLD FRONT SLIDES EAST AND LOW LEVEL FLOW TURNS MORE WESTERLY. OVER WESTERN MACKINAC COUNTY...INITIALLY LOW LEVEL SOUTHWEST FLOW WILL BACK SOUTHEASTERLY THIS MORNING AS WEAK SURFACE LOW MOVES INTO NORTHERN LAKE MICHIGAN. THIS WILL SET UP AN ENHANCED LOW LEVEL CONVERGENCE BAND OF HEAVIER SNOWFALL JUST OFFSHORE OF MACKINAC COUNTY THIS MORNING WHICH WILL BE DRIVEN TOWARD US-2 THIS AFTERNOON WITH NORTHEAST PROGRESSION OF SURFACE LOW. EXPECT LAKE ENHANCED BAND OF HEAVIER SNOW WEST OF THE US-131 CORRIDOR LATE THIS AFTERNOON/EARLY EVENING TO PUSH INLAND THIS EVENING WITH THE FRONT...GRADUALLY WEAKENING AS IT LOSES THE LAKE INFLUENCE. LOW LEVEL FLOW TRANSITIONS RAPIDLY TO WESTERLY BY LATER THIS EVENING AND BUFKIT SOUNDINGS SHOW A QUICK RAMP UP TO THE LAKE EFFECT SNOW MACHINE. THE LAKE EFFECT PARAMETERS REALLY LOOK QUITE SIMILAR TO THE BIG LAKE EFFECT EVENT MONDAY NIGHT/TUESDAY OVER PARTS OF THE AREA AND EXPECT MANY OF THE SAME AREAS TO BE HIT AGAIN WITH SOME SIGNIFICANT LAKE EFFECT ACCUMULATIONS. FORECAST SOUNDINGS SHOW DEEP MOISTURE UP THROUGH H7 AND NO REAL INVERSION...WITH EXCELLENT OMEGA PEGGED SQUARELY IN THE DGZ WITH DELTA T/S OF 20+ DEGC. SNOW WILL BE OF THE DRY/POWDERY VARIETY AND WITH SOME GUSTY WINDS...WILL ONCE AGAIN BE DEALING WITH BLOWING/DRIFTING AND AREAS OF VERY LOW VISIBILITIES. HEADLINES...CHALLENGING TO SAY THE LEAST. LAKE ENHANCED EVENT TODAY WILL BE HANDLED WITH WINTER WEATHER ADVISORIES. WILL ONLY CARRY THE ADVISORY THROUGH THIS EVENING FOR MACKINAC COUNTY...WHERE TRANSITION TO WEST FLOW LAKE EFFECT SHOULD DIMINISH THEIR SNOWFALL. WILL RUN THE ADVISORY FOR MANISTEE/BENZIE/LEELANAU COUNTIES THROUGH 12Z THURSDAY...WILL FULL EXPECTATION THAT THESE HEADLINES WILL BE EXTENDED IN TIME/AREA FOR THURSDAY-THURSDAY NIGHT TO ACCOUNT FOR ONGOING LAKE EFFECT. WITH REGARD TO THE WEST-NORTHWEST FLOW LAKE EFFECT EVENT LATER TONIGHT THROUGH THURSDAY NIGHT...WILL HOIST A LAKE EFFECT SNOW WATCH. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 340 AM EST WED NOV 19 2014 ...ANOTHER SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED THURSDAY... HIGH IMPACT WEATHER POTENTIAL: ANOTHER ROUND OF POTENTIALLY HEAVY LAKE EFFECT SNOW THURSDAY. AREAS OF BLOWING SNOW AND HAZARDOUS DRIVING CONDITIONS EXPECTED. PATTERN SYNOPSIS/CURRENT CONDITIONS: EXTREMELY AMPLIFIED PATTERN CONTINUES FOR JUST A TOUCH LONGER...WITH ONE LAST ARCTIC SHORTWAVE SET TO VISIT OUR AREA LATER TODAY THROUGH THURSDAY. PATTERN CHANGE THEREAFTER IS RATHER AN ABRUPT ONE. AN EXCEPTIONALLY STRONG AND EXTENDED PACIFIC JET EXPECTED TO PUNCH INTO THE WESTERN CONUS LATER THIS WEEK WILL DO THE TRICK. THIS FEATURE ESSENTIALLY REVERSES THE CURRENT PATTERN BY ESTABLISHING WESTERN TROUGHING AND FLOODING MUCH OF THE CONUS WITH MODIFIED PACIFIC ORIGINATED AIR BY THE WEEKEND INTO THE START OF NEXT WEEK. PRIMARY FORECAST CONCERNS/CHALLENGES: NEARLY ALL FOCUS CENTERED ON ANOTHER POTENTIALLY SIGNIFICANT LAKE EFFECT/BLOWING SNOW EVENT THURSDAY. SNOW AMOUNTS...LOCATION OF STEADIEST AND HEAVIEST LAKE BANDING...AND HEADLINE CONSIDERATION ALL NEED ADDRESSING. DETAILS: MORE LAKE EFFECT FUN! WELL ESTABLISHED PRIMARILY WNW FLOW LAKE EFFECT EXPECTED TO BE ONGOING THURSDAY MORNING...WITH FLOW EXPECTED TO VEER MORE NW TO NNW NORTH OF THE BIG BRIDGE WITH PASSAGE OF SURFACE TROUGH DURING THE MORNING. THERMODYNAMIC AND KINEMATIC PROFILES LOOK GOOD TO EXCELLENT ONCE AGAIN...WITH LAKE INDUCED EQL EXCEEDING 10KFT...OMEGA MAX WELL WITHIN THE DGZ...AND GOOD CYCLONIC FLOW/MOISTURE VIA EXITING LOW PRESSURE. OFF LAKE MICHIGAN: WHILE PARAMETERS LOOK TO FALL JUST SHORT OF THIS PAST EVENT...CONDITIONS LOOK PRIME TO PRODUCE ANOTHER 3 TO 6 INCHES...LOCALLY HIGHER...THURSDAY (THIS WILL BE ON TOP OFF WHAT OCCURS WEDNESDAY NIGHT). TARGET AREAS WILL LOOK FAMILIAR...WITH NORTHWEST LOWER LOCATIONS BETWEEN M-32 AND M-68 EXPECTED TO TAKE THE BRUNT OF THE ACTIVITY...WITH LIGHTER SNOW ELSEWHERE. FLOW DOES NOT LOOK QUITE AS STRONG AS THIS PAST SYSTEM...SUGGESTING THE HIGHEST AMOUNTS IN THE MORE TRADITIONAL AREAS ALONG AND WEST OF INTERSTATE 75. OF COURSE...PREDICTING PLACEMENT OF PARTICULAR BANDS NEXT TO IMPOSSIBLE...ALTHOUGH STREAM-LINE WIND ANALYSIS SUGGEST POTENTIAL FOR DOMINATE BANDS ALONG/JUST NORTH OF THE M-32 CORRIDOR AND JUST SOUTHEAST OF LITTLE TRAVERSE BAY. WINDS DO BEGIN TO VEER DURING THE AFTERNOON WITH APPROACH AND PASSAGE OF LAKE REINFORCED TROUGHING. WHILE WINDS WILL NOT BE EXTREME...GUSTS TO 20 TO 25 MPH WILL PRODUCE AREAS OF BLOWING/DRIFTING SNOW...WHICH WILL FURTHER CONTRIBUTE TO VERY LOW VISIBILITIES IN THE HEAVIER SNOW BANDS. DEVELOPMENT OF MORE NEUTRAL TO SLIGHTLY ANTICYCLONIC FLOW AND LOWERING INVERSION/DEPLETING MOISTURE SHOULD BRING SNOW INTENSITY DOWN RATHER RAPIDLY HEADING INTO THURSDAY NIGHT...PERHAPS BRINGING JUST A COUPLE MORE INCHES TO NW FLOW AREAS. LAKE SUPERIOR...PARAMETERS LOOK AS GOOD AS OVER LAKE MICHIGAN...JUST WITH A MUCH QUICKER VEERING OF THE WINDS WITH PASSAGE OF TROUGHING THURSDAY MORNING. WOULD EXPECT A BAND OF ENHANCED SNOW ALONG THIS FEATURE...PERHAPS TARGETING THE SOO BEFORE PUSHING WELL WEST INTO FAR NORTHWEST CHIPPEWA AND MACKINAC COUNTIES FOR LATER IN THE MORNING AND AFTERNOON. SAME SNOW ACCUMULATIONS APPLY...3 TO 6 WITH LOCALLY HIGHER AMOUNTS IN THE TRADITIONAL SNOWBELTS. AS MENTIONED...LOOKS LIKE THE BEST SNOWS WILL EXIT SAULT STE MARIE BY MIDDAY. SNOW LOOKS TO POTENTIALLY PUSH BACK INTO THE SOO THURSDAY NIGHT AS WINDS BACK MORE NORTHWESTERLY...WITH A COUPLE MORE INCHES POSSIBLE. WHILE THE MAJORITY OF TIME WAS SPENT ON THE EARLIER PERIODS...PERUSAL OF LATEST MODEL TRENDS CONTINUES TO ADD INCREASING CONFIDENCE TO A MUCH DESERVED REPRIEVE FROM THE WINTER WEATHER OF LATE...ESPECIALLY BY THE END OF THE WEEKEND INTO THE START OF NEXT WEEK. STILL LOOKING COLD FRIDAY...WITH A FEW LINGERING LIGHT LAKE INDUCED SNOW SHOWERS. MODIFICATION RAMPS UP SATURDAY AS LONG WAVE PATTERN FLATTENS SUBSTANTIALLY AND CURRENT COLD DOME EJECTS WELL TO OUR NORTHEAST. NEARLY ALL HIGH RES DETERMINISTIC AND THEIR ENSEMBLE SUITES AGREE...A RATHER REMARKABLE QUICK EXIT TO SUCH AN ENTRENCHED COLD PATTERN. WAA MAY BE ABLE TO KICK OFF A LITTLE RAIN AND SNOW SATURDAY WHEN HIGHS...READY FOR THIS...ACTUALLY REACH ABOVE FREEZING. ONLY GETS MORE MILD AND WETTER BY SUNDAY INT MONDAY AS LOW PRESSURE MOVES NORTH INTO OR JUST WEST OF OUR AREA. REALLY NO COLD AIR IN SIGHT BY THIS TIME (HIGHS PUSHING THE LOWER 40S SUNDAY AND MONDAY)...SUGGESTING ALL PRECIPITATION FALLING AS RAIN. DEPTH OF THIS SYSTEM STILL IN QUESTION...WITH SOME PROGS SUPPORTING A SUB 980MB LOW...POTENTIALLY LEADING TO SOME RATHER WINDY CONDITIONS. TIMING DEPENDENT OF COURSE...BUT POST-SYSTEM COOL DOWN BEGINS SOMETIME LATER MONDAY/MONDAY NIGHT...BRINGING A RETURN TO BELOW NORMAL TEMPERATURES AND PERHAPS SOME MORE SNOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1240 PM EST WED NOV 19 2014 SYNOPTIC SNOW TRANSITIONING TO LAKE EFFECT SNOW SHOWERS WILL RESULT IN PERIODS OF IFR CONDITIONS AT PLN/TVC/MBL THROUGH TONIGHT. IFR CONDITIONS AT APN THIS AFTERNOON WILL PROBABLY TRANSITION TO PREVAILING MVFR CONDITIONS THIS EVENING. && .MARINE... ISSUED AT 340 AM EST WED NOV 19 2014 A STORM SYSTEM WILL MOVE OUT OF THE UPPER MIDWEST AND INTO THE GREAT LAKES THROUGH TONIGHT...PUSHING A COLD FRONT THROUGH THE AREA. THE GRADIENT WILL TIGHTEN WITH FROPA...WITH WINDS SHIFTING TO THE WEST. GALE FORCE GUSTS WILL BE POSSIBLE ON PORTIONS OF LAKE MICHIGAN INTO EARLY THURSDAY...WITH SMALL CRAFT ADVISORIES ELSEWHERE. ADDITIONAL SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR LAKES HURON AND SUPERIOR TONIGHT INTO THURSDAY NIGHT. WEST/NORTHWEST FLOW LAKE EFFECT SNOW WILL DEVELOP LATER TONIGHT AND CONTINUE INTO THURSDAY...RESULTING IN AREAS OF REDUCED VISIBILITIES ALONG THE COASTLINE. QUIETER WEATHER AND HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES TO END THE WEEK. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY UNTIL 1 AM EST THURSDAY FOR MIZ015. WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ020-025- 031. LAKE EFFECT SNOW WATCH FROM 10 PM EST THIS EVENING THROUGH LATE THURSDAY NIGHT FOR MIZ008-016-017-019-021-022. LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LMZ323-341. GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LMZ342-344>346. LS...NONE. && $$ UPDATE...JPB SYNOPSIS...MSB SHORT TERM...KEYSOR LONG TERM...MSB MARINE...KEYSOR
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1148 AM EST WED NOV 19 2014 .SYNOPSIS... ISSUED AT 340 AM EST WED NOV 19 2014 LOW PRESSURE PASSING ACROSS THE NORTHERN LAKES WILL BRING ANOTHER ROUND OF LAKE EFFECT SNOW...AT TIMES HEAVY...THROUGH THURSDAY. TEMPERATURES WILL TURN MILDER DURING THE UPCOMING WEEKEND... SETTING THE STAGE FOR SOME RAIN...ESPECIALLY BY SUNDAY AND SUNDAY NIGHT. && .UPDATE... ISSUED AT 1148 AM EST WED NOV 19 2014 14Z SURFACE ANALYSIS SHOWS A WEAK 1006MB LOW OVER NORTHERN WISCONSIN WITH A TRAILING COLD FRONT INTO ILLINOIS/CENTRAL MISSOURI. COMBINATION OF WARM ADVECTION AND LOW/MID LEVEL TROUGHING PUSHING AN AREA OF MOSTLY LIGHT SNOW ACROSS MICHIGAN...WITH ENHANCED RADAR RETURNS OVER LAKE MICHIGAN WITH SOME DECENT LAKE INDUCED INSTABILITY AND STRONG MID LEVEL CONVERGENCE HELPING FORCE A CONVECTIVE COMPONENT. UPSTREAM COLD FRONT MAKING STEADY PROGRESS EAST WITH A BROAD AREA OF 2-3MB/3H PRESSURE FALLS OUT AHEAD OF IT...EXPECTING FRONT TO PUSH IN TO WESTERN LOWER IN THE 18Z-19Z TIME FRAME. AS IT DOES...EXPECT HEAVIER SNOW SQUALL OVER LAKE MICHIGAN TO GET PUSHED INLAND ALONG THE US-31 CORRIDOR. ALSO EXPECT TO SEE NARROWER LAKE CONVECTION OVER THE FAR NORTHERN PART OF THE LAKE TO EXPAND AS LOW LEVEL CONVERGENCE STRENGTHENS...FOCUSING SNOWFALL INTO WESTER MACKINAC COUNTY. SO "TODAY" ADVISORIES WILL REMAIN AS IT. REMAINDER OF THE AREA WILL SEE PERIODS OF LIGHT SNOW WITH MINIMAL ACCUMULATIONS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 340 AM EST WED NOV 19 2014 ...MORE SIGNIFICANT LAKE EFFECT SNOW ON THE WAY... HIGH IMPACT WEATHER POTENTIAL: WIDESPREAD MOSTLY LIGHT SYNOPTIC SNOW TODAY WITH LAKE ENHANCEMENT NEAR LAKE MICHIGAN...THEN ANOTHER ROUND OF SIGNIFICANT LAKE EFFECT SNOWFALL DEVELOPING TONIGHT. PATTERN SYNOPSIS/FORECAST: UPSTREAM SHORTWAVE TROUGH OVER THE UPPER MISSISSIPPI VALLEY DRIVING A BAND OF WARM AIR ADVECTION SNOW ACROSS THE UPPER MIDWEST. THIS SHORTWAVE FEATURE WILL SERVE TO RE-INFORCE LONGWAVE TROUGH OVER THE EASTERN CONUS AND USHER IN ANOTHER SURGE OF EARLY SEASON ARCTIC AIR WITH LAKE EFFECT SNOW. PRIMARY FORECAST CONCERNS: NUMEROUS. LAKE ENHANCED SNOW ACCUMULATIONS TODAY NEAR THE LAKE MICHIGAN COAST. THEN QUICK TRANSITION TO WEST-NORTHWEST LAKE EFFECT TONIGHT WITH SIGNIFICANT ACCUMULATIONS POSSIBLE. IN ADDITION...GUSTY WINDS MAY CREATE LOW VISIBILITIES AND TRAVEL PROBLEMS WITHIN HEAVIER SNOWSHOWERS. AFOREMENTIONED WARM ADVECTION LIGHT SNOW WILL DEVELOP ACROSS NORTHERN MICHIGAN TODAY WITH BROAD AREA OF ISENTROPIC ASCENT. THIS IS THE EASIEST PORTION OF THE FORECAST...AS ALL AREAS SHOULD SEE AT LEAST SOME SNOW TODAY. H7 MIXING RATIO/S ONLY AROUND 1 G/KG...SO ONLY LIGHT ACCUMULATIONS ON THE ORDER OF 1-2 INCHES. THE EXCEPTION TO THE LIGHTER SNOWS WILL BE CLOSER TO LAKE MICHIGAN...WHERE INCREASING SYNOPTIC FORCING COMBINED WITH PLENTY OF OVER-LAKE INSTABILITY /DELTA T/S IN THE MID-UPPER TEENS/ WILL RESULT IN ENHANCED SNOWFALL. SOME QUESTION MARKS AS TO HOW THE LOW LEVEL FLOW WILL EVOLVE WITH SURFACE LOW OVER NORTHERN LAKE MICHIGAN. WILL LEAN TOWARD HIGH RESOLUTION HRRR FOR LOW LEVEL PATTERN EVOLUTION INTO EARLY THIS AFTERNOON. IMPRESSIVE LOW LEVEL CONVERGENCE SIGNATURE WITH 0-2KM CAPE OF 100 J/KG UP THE SPINE OF LAKE MICHIGAN THIS MORNING WILL BE DRIVEN INLAND TOWARD MANISTEE/BENZIE/LEELANAU COUNTIES AS COLD FRONT SLIDES EAST AND LOW LEVEL FLOW TURNS MORE WESTERLY. OVER WESTERN MACKINAC COUNTY...INITIALLY LOW LEVEL SOUTHWEST FLOW WILL BACK SOUTHEASTERLY THIS MORNING AS WEAK SURFACE LOW MOVES INTO NORTHERN LAKE MICHIGAN. THIS WILL SET UP AN ENHANCED LOW LEVEL CONVERGENCE BAND OF HEAVIER SNOWFALL JUST OFFSHORE OF MACKINAC COUNTY THIS MORNING WHICH WILL BE DRIVEN TOWARD US-2 THIS AFTERNOON WITH NORTHEAST PROGRESSION OF SURFACE LOW. EXPECT LAKE ENHANCED BAND OF HEAVIER SNOW WEST OF THE US-131 CORRIDOR LATE THIS AFTERNOON/EARLY EVENING TO PUSH INLAND THIS EVENING WITH THE FRONT...GRADUALLY WEAKENING AS IT LOSES THE LAKE INFLUENCE. LOW LEVEL FLOW TRANSITIONS RAPIDLY TO WESTERLY BY LATER THIS EVENING AND BUFKIT SOUNDINGS SHOW A QUICK RAMP UP TO THE LAKE EFFECT SNOW MACHINE. THE LAKE EFFECT PARAMETERS REALLY LOOK QUITE SIMILAR TO THE BIG LAKE EFFECT EVENT MONDAY NIGHT/TUESDAY OVER PARTS OF THE AREA AND EXPECT MANY OF THE SAME AREAS TO BE HIT AGAIN WITH SOME SIGNIFICANT LAKE EFFECT ACCUMULATIONS. FORECAST SOUNDINGS SHOW DEEP MOISTURE UP THROUGH H7 AND NO REAL INVERSION...WITH EXCELLENT OMEGA PEGGED SQUARELY IN THE DGZ WITH DELTA T/S OF 20+ DEGC. SNOW WILL BE OF THE DRY/POWDERY VARIETY AND WITH SOME GUSTY WINDS...WILL ONCE AGAIN BE DEALING WITH BLOWING/DRIFTING AND AREAS OF VERY LOW VISIBILITIES. HEADLINES...CHALLENGING TO SAY THE LEAST. LAKE ENHANCED EVENT TODAY WILL BE HANDLED WITH WINTER WEATHER ADVISORIES. WILL ONLY CARRY THE ADVISORY THROUGH THIS EVENING FOR MACKINAC COUNTY...WHERE TRANSITION TO WEST FLOW LAKE EFFECT SHOULD DIMINISH THEIR SNOWFALL. WILL RUN THE ADVISORY FOR MANISTEE/BENZIE/LEELANAU COUNTIES THROUGH 12Z THURSDAY...WILL FULL EXPECTATION THAT THESE HEADLINES WILL BE EXTENDED IN TIME/AREA FOR THURSDAY-THURSDAY NIGHT TO ACCOUNT FOR ONGOING LAKE EFFECT. WITH REGARD TO THE WEST-NORTHWEST FLOW LAKE EFFECT EVENT LATER TONIGHT THROUGH THURSDAY NIGHT...WILL HOIST A LAKE EFFECT SNOW WATCH. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 340 AM EST WED NOV 19 2014 ...ANOTHER SIGNIFICANT LAKE EFFECT SNOW EVENT EXPECTED THURSDAY... HIGH IMPACT WEATHER POTENTIAL: ANOTHER ROUND OF POTENTIALLY HEAVY LAKE EFFECT SNOW THURSDAY. AREAS OF BLOWING SNOW AND HAZARDOUS DRIVING CONDITIONS EXPECTED. PATTERN SYNOPSIS/CURRENT CONDITIONS: EXTREMELY AMPLIFIED PATTERN CONTINUES FOR JUST A TOUCH LONGER...WITH ONE LAST ARCTIC SHORTWAVE SET TO VISIT OUR AREA LATER TODAY THROUGH THURSDAY. PATTERN CHANGE THEREAFTER IS RATHER AN ABRUPT ONE. AN EXCEPTIONALLY STRONG AND EXTENDED PACIFIC JET EXPECTED TO PUNCH INTO THE WESTERN CONUS LATER THIS WEEK WILL DO THE TRICK. THIS FEATURE ESSENTIALLY REVERSES THE CURRENT PATTERN BY ESTABLISHING WESTERN TROUGHING AND FLOODING MUCH OF THE CONUS WITH MODIFIED PACIFIC ORIGINATED AIR BY THE WEEKEND INTO THE START OF NEXT WEEK. PRIMARY FORECAST CONCERNS/CHALLENGES: NEARLY ALL FOCUS CENTERED ON ANOTHER POTENTIALLY SIGNIFICANT LAKE EFFECT/BLOWING SNOW EVENT THURSDAY. SNOW AMOUNTS...LOCATION OF STEADIEST AND HEAVIEST LAKE BANDING...AND HEADLINE CONSIDERATION ALL NEED ADDRESSING. DETAILS: MORE LAKE EFFECT FUN! WELL ESTABLISHED PRIMARILY WNW FLOW LAKE EFFECT EXPECTED TO BE ONGOING THURSDAY MORNING...WITH FLOW EXPECTED TO VEER MORE NW TO NNW NORTH OF THE BIG BRIDGE WITH PASSAGE OF SURFACE TROUGH DURING THE MORNING. THERMODYNAMIC AND KINEMATIC PROFILES LOOK GOOD TO EXCELLENT ONCE AGAIN...WITH LAKE INDUCED EQL EXCEEDING 10KFT...OMEGA MAX WELL WITHIN THE DGZ...AND GOOD CYCLONIC FLOW/MOISTURE VIA EXITING LOW PRESSURE. OFF LAKE MICHIGAN: WHILE PARAMETERS LOOK TO FALL JUST SHORT OF THIS PAST EVENT...CONDITIONS LOOK PRIME TO PRODUCE ANOTHER 3 TO 6 INCHES...LOCALLY HIGHER...THURSDAY (THIS WILL BE ON TOP OFF WHAT OCCURS WEDNESDAY NIGHT). TARGET AREAS WILL LOOK FAMILIAR...WITH NORTHWEST LOWER LOCATIONS BETWEEN M-32 AND M-68 EXPECTED TO TAKE THE BRUNT OF THE ACTIVITY...WITH LIGHTER SNOW ELSEWHERE. FLOW DOES NOT LOOK QUITE AS STRONG AS THIS PAST SYSTEM...SUGGESTING THE HIGHEST AMOUNTS IN THE MORE TRADITIONAL AREAS ALONG AND WEST OF INTERSTATE 75. OF COURSE...PREDICTING PLACEMENT OF PARTICULAR BANDS NEXT TO IMPOSSIBLE...ALTHOUGH STREAM-LINE WIND ANALYSIS SUGGEST POTENTIAL FOR DOMINATE BANDS ALONG/JUST NORTH OF THE M-32 CORRIDOR AND JUST SOUTHEAST OF LITTLE TRAVERSE BAY. WINDS DO BEGIN TO VEER DURING THE AFTERNOON WITH APPROACH AND PASSAGE OF LAKE REINFORCED TROUGHING. WHILE WINDS WILL NOT BE EXTREME...GUSTS TO 20 TO 25 MPH WILL PRODUCE AREAS OF BLOWING/DRIFTING SNOW...WHICH WILL FURTHER CONTRIBUTE TO VERY LOW VISIBILITIES IN THE HEAVIER SNOW BANDS. DEVELOPMENT OF MORE NEUTRAL TO SLIGHTLY ANTICYCLONIC FLOW AND LOWERING INVERSION/DEPLETING MOISTURE SHOULD BRING SNOW INTENSITY DOWN RATHER RAPIDLY HEADING INTO THURSDAY NIGHT...PERHAPS BRINGING JUST A COUPLE MORE INCHES TO NW FLOW AREAS. LAKE SUPERIOR...PARAMETERS LOOK AS GOOD AS OVER LAKE MICHIGAN...JUST WITH A MUCH QUICKER VEERING OF THE WINDS WITH PASSAGE OF TROUGHING THURSDAY MORNING. WOULD EXPECT A BAND OF ENHANCED SNOW ALONG THIS FEATURE...PERHAPS TARGETING THE SOO BEFORE PUSHING WELL WEST INTO FAR NORTHWEST CHIPPEWA AND MACKINAC COUNTIES FOR LATER IN THE MORNING AND AFTERNOON. SAME SNOW ACCUMULATIONS APPLY...3 TO 6 WITH LOCALLY HIGHER AMOUNTS IN THE TRADITIONAL SNOWBELTS. AS MENTIONED...LOOKS LIKE THE BEST SNOWS WILL EXIT SAULT STE MARIE BY MIDDAY. SNOW LOOKS TO POTENTIALLY PUSH BACK INTO THE SOO THURSDAY NIGHT AS WINDS BACK MORE NORTHWESTERLY...WITH A COUPLE MORE INCHES POSSIBLE. WHILE THE MAJORITY OF TIME WAS SPENT ON THE EARLIER PERIODS...PERUSAL OF LATEST MODEL TRENDS CONTINUES TO ADD INCREASING CONFIDENCE TO A MUCH DESERVED REPRIEVE FROM THE WINTER WEATHER OF LATE...ESPECIALLY BY THE END OF THE WEEKEND INTO THE START OF NEXT WEEK. STILL LOOKING COLD FRIDAY...WITH A FEW LINGERING LIGHT LAKE INDUCED SNOW SHOWERS. MODIFICATION RAMPS UP SATURDAY AS LONG WAVE PATTERN FLATTENS SUBSTANTIALLY AND CURRENT COLD DOME EJECTS WELL TO OUR NORTHEAST. NEARLY ALL HIGH RES DETERMINISTIC AND THEIR ENSEMBLE SUITES AGREE...A RATHER REMARKABLE QUICK EXIT TO SUCH AN ENTRENCHED COLD PATTERN. WAA MAY BE ABLE TO KICK OFF A LITTLE RAIN AND SNOW SATURDAY WHEN HIGHS...READY FOR THIS...ACTUALLY REACH ABOVE FREEZING. ONLY GETS MORE MILD AND WETTER BY SUNDAY INT MONDAY AS LOW PRESSURE MOVES NORTH INTO OR JUST WEST OF OUR AREA. REALLY NO COLD AIR IN SIGHT BY THIS TIME (HIGHS PUSHING THE LOWER 40S SUNDAY AND MONDAY)...SUGGESTING ALL PRECIPITATION FALLING AS RAIN. DEPTH OF THIS SYSTEM STILL IN QUESTION...WITH SOME PROGS SUPPORTING A SUB 980MB LOW...POTENTIALLY LEADING TO SOME RATHER WINDY CONDITIONS. TIMING DEPENDENT OF COURSE...BUT POST-SYSTEM COOL DOWN BEGINS SOMETIME LATER MONDAY/MONDAY NIGHT...BRINGING A RETURN TO BELOW NORMAL TEMPERATURES AND PERHAPS SOME MORE SNOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 616 AM EST WED NOV 19 2014 LOW LEVEL WINDS WILL GRADUALLY BACK TO THE S/SW TODAY AHEAD OF AN AREA OF LOW PRESSURE LIFTING INTO THE GREAT LAKES REGION. THIS SYSTEM WILL PRODUCE WIDESPREAD LIGHT SYNOPTICALLY DRIVEN SNOW...AND WILL ENHANCE ONGOING S/SW FLOW LAKE EFFECT SNOW SHOWERS IMPACTING PORTIONS OF FAR NW LWR MICHIGAN...THE STRAITS AND MACKINAC COUNTY. WINDS WILL SHIFT TO THE WEST TONIGHT AND INCREASE WITH GUSTS OF 20-30KTS POSSIBLE. LAKE EFFECT SNOW SHOWERS WILL DEVELOP DOWNWIND OF LAKE MICHIGAN...ALONG WITH AREAS OF BLOWING SNOW. WIDESPREAD MVFR CONDITIONS THROUGH THE PERIOD WITH AREAS OF LIFR/IFR WITHIN HEAVIER SNOW SHOWER ACTIVITY. && .MARINE... ISSUED AT 340 AM EST WED NOV 19 2014 A STORM SYSTEM WILL MOVE OUT OF THE UPPER MIDWEST AND INTO THE GREAT LAKES THROUGH TONIGHT...PUSHING A COLD FRONT THROUGH THE AREA. THE GRADIENT WILL TIGHTEN WITH FROPA...WITH WINDS SHIFTING TO THE WEST. GALE FORCE GUSTS WILL BE POSSIBLE ON PORTIONS OF LAKE MICHIGAN INTO EARLY THURSDAY...WITH SMALL CRAFT ADVISORIES ELSEWHERE. ADDITIONAL SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR LAKES HURON AND SUPERIOR TONIGHT INTO THURSDAY NIGHT. WEST/NORTHWEST FLOW LAKE EFFECT SNOW WILL DEVELOP LATER TONIGHT AND CONTINUE INTO THURSDAY...RESULTING IN AREAS OF REDUCED VISIBILITIES ALONG THE COASTLINE. QUIETER WEATHER AND HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES TO END THE WEEK. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY UNTIL 1 AM EST THURSDAY FOR MIZ015. WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ020-025- 031. LAKE EFFECT SNOW WATCH FROM 10 PM EST THIS EVENING THROUGH LATE THURSDAY NIGHT FOR MIZ008-016-017-019-021-022. LH...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LMZ323-341. GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR LMZ342-344>346. LS...NONE. && $$ UPDATE...JPB SYNOPSIS...MSB SHORT TERM...KEYSOR LONG TERM...MSB AVIATION...KEYSOR MARINE...KEYSOR
AREA FORECAST DISCUSSION
NWS BILLINGS MT
338 PM MST WED NOV 19 2014 .SHORT TERM...VALID FOR THU AND FRI... A WARMING TREND IS EXPECTED THE NEXT FEW DAYS AS FLOW ALOFT SHIFTS TO A MORE WESTERLY DIRECTION AND ALLOWS MILD PACIFIC AIR TO SPREAD EASTWARD INTO THE REGION. TONIGHT...THE STRATUS /LOW CLOUDS/ IN SOUTHEASTERN MT HAS ACTUALLY BEEN BREAKING UP THIS AFTERNOON PER RECENT SATELLITE IMAGERY...BUT WE FEEL THAT IT WILL REDEVELOP AGAIN OVERNIGHT. THAT IDEA HAS GOOD SUPPORT FROM RECENT HRRR RUNS AND THE 12 UTC NAM AS WEAK LOW-LEVEL FLOW PERSISTS. WE ALSO ADDED PATCHY FOG INTO THE FORECAST AFTER 06 UTC OVER SOUTHEASTERN MT AND AS FAR WEST AS HYSHAM AS THE EDGES OF A STRATUS FIELD LIKE THE ONE WE EXPECT ARE TYPICALLY FAVORABLE FOR THE FORMATION OF FOG. THAT NOTION TOO HAS STRONG SUPPORT IN THE 12 UTC NCEP WRF-ARW AND WRF-NMM AS WELL AS RECENT HRRR RUNS. IT LOOKS LIKE AN UNEVENTFUL NIGHT OVER THE REST OF THE AREA. THURSDAY...IF LOW CLOUDS AND/OR PATCHY FOG DOES INDEED FORM ACROSS SOUTHEASTERN MT TONIGHT...IT WILL LIKELY LINGER THROUGH THE MIDDAY HOURS AS LIGHT LOW-LEVEL WINDS BECOME SOUTHERLY AND BOUNDARY LAYER MIXING REMAINS VERY WEAK. WE LEANED ON THE SLIGHTLY COOLER...RAW 2 METER TEMPERATURES FOR HIGHS IN THOSE AREAS WITH WARMING DEPENDENT ON HOW WIDESPREAD OR LONG-LASTING STRATUS IS /OR IS NOT/. HIGHS IN GENERAL WILL WARM OVER THE REST OF THE AREA THOUGH AND THE BLENDED 12 UTC MODEL GUIDANCE WE USED TO BUILD THE FORECAST CALLS FOR HIGH TEMPERATURES IN THE LOWER TO MIDDLE 40S F IN MOST AREAS. FRIDAY...SEASONABLY MILD WEATHER WILL CONTINUE WITH HIGHS EXPECTED TO BE IN THE 40S F ONCE AGAIN IN AN AIR MASS CHARACTERIZED BY 850- MB TEMPERATURES OF +4 TO +6 C. THE LEE-SIDE PRESSURE TROUGH SHOULD DEEPEN FRIDAY NIGHT IN ADVANCE OF AN ENERGETIC SHORTWAVE TROUGH SO WINDS SHOULD INCREASE IN THE FOOTHILLS. LIVINGSTON AND NYE WILL BE CANDIDATES FOR A WIND ADVISORY GIVEN THE EXPECTED PLACEMENT OF THE SURFACE PRESSURE FALL MAXIMUM TO THEIR NORTHWEST LATE FRIDAY NIGHT AS A MOUNTAIN-TOP STABLE LAYER STRENGTHENS. SCHULTZ .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... MILD AND WINDY WEATHER SATURDAY WILL TRANSITION TO SEASONABLY COOL AND UNSETTLED WEATHER BEGINNING SUNDAY. THE 12 UTC GUIDANCE STAYED IN RELATIVELY GOOD AGREEMENT WITH REGARD TO A STRENGTHENING SHORT- WAVE TROUGH THAT WILL CROSS THE REGION AROUND SATURDAY NIGHT. SNOW SHOULD FALL IN THE HIGH COUNTRY AS THE WAVE PASSES AND THERE IS AT LEAST A CHANCE OF LOWER-ELEVATION SHOWER ACTIVITY TOO. WINDS COULD BE AT THEIR PEAK IN THE FOOTHILLS DURING THE DAY SATURDAY WITH 60+ MPH GUSTS POSSIBLE AT LIVINGSTON AND NYE. IN THE WAKE OF THE WEEKEND SHORTWAVE...FLOW ALOFT WILL TURN NORTH- WESTERLY AS A MEAN TROUGH DEEPENS IN THE CENTRAL UNITED STATES. WE ARE CALLING FOR SEASONABLY COOL TEMPERATURES WITH A CHANCE OF SNOW SHOWERS IN THIS PATTERN IN THE EARLY AND MIDDLE PART OF NEXT WEEK. HOWEVER...THERE IS CONSIDERABLE UNCERTAINTY IN THE FORECAST BY THE TIME NEXT WEDNESDAY ROLLS AROUND...WHICH IS TROUBLING SINCE THAT/S A MAJOR TRAVEL DAY AHEAD OF THANKSGIVING. THE ISSUE IS THAT THE 00 AND 12 UTC ECMWF SOLUTIONS AMPLIFY RIDGING OFF THE WEST COAST MUCH MORE THAN THEIR GFS COUNTERPARTS...WHICH ALLOWS ARCTIC AIR TO DUMP SOUTHWARD AND A SO-CALLED SLIDER SHORTWAVE TO CUT UNDER IT. IF THE ECMWF IDEA IS RIGHT THEN SNOW AND MUCH COLDER WEATHER WOULD RESULT RIGHT NEAR THE HOLIDAY TRAVEL PERIOD. HOWEVER...THE GFS IS CALLING FOR MUCH-LESS-AMPLIFIED RIDGING OFF THE COAST...WHICH IN TURN DOES NOT OPEN THE DOOR TO NEARLY AS COLD OF AN AIR MASS. IT IS TOO SOON TO SAY WHICH OF THESE IDEAS IS RIGHT AS EVEN THOUGH IT/S COMMON TO SEE THE ECMWF PICK UP ON A SCENARIO LIKE THIS FIRST...ITS VERY OWN ENSEMBLE MEMBERS SUGGEST IT COULD BE TOO COLD AND SNOWY OF A MODEL SOLUTION. STAY TUNED. SCHULTZ && .AVIATION... EXPECT VFR CONDITIONS TO PREVAIL ACROSS MUCH OF THE AREA TONIGHT INTO TOMORROW. SOME LOW CEILINGS AND MVFR CONDITIONS WILL BE POSSIBLE AT MILES CITY. SOME FOG MAY BE POSSIBLE AROUND MILES CITY...BUT ONLY HAVE VCFG IN THE TAFS. REIMER && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 019/044 029/045 029/046 029/040 025/037 023/037 022/035 00/B 00/B 13/W 32/J 22/J 33/J 33/J LVM 019/044 028/043 031/042 023/034 020/033 017/033 023/034 00/N 00/N 14/W 32/J 22/J 33/J 33/J HDN 014/042 023/045 021/047 026/040 020/036 018/037 017/036 00/B 00/B 03/W 32/J 22/J 33/J 33/J MLS 009/032 020/041 020/040 025/034 014/029 013/033 014/031 00/B 00/B 02/W 32/J 22/J 22/J 32/J 4BQ 010/037 020/043 020/043 025/036 017/031 016/033 015/032 00/B 00/B 02/W 32/J 22/J 23/J 32/J BHK 003/030 017/040 020/039 024/030 011/024 011/029 013/028 00/B 00/B 01/B 33/J 22/J 23/J 22/J SHR 016/045 021/045 020/045 022/036 016/033 014/035 016/034 00/B 10/B 02/W 32/J 22/J 23/J 33/J && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS TULSA OK
1125 AM CST WED NOV 19 2014 .DISCUSSION... THE 18Z TAF DISCUSSION IS INCLUDED BELOW... && .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS WILL PREVAIL. A WIND SHIFT FROM WEST TO LIGHT NORTHERLY WILL OCCUR TODAY AT MOST SITES...WITH A LIGHT AND VARIABLE WIND AFTER THAT. THE LATEST MODEL DATA SUGGESTS LOW LEVEL MOISTURE RETURN WILL BE UNDERWAY AS WE GO INTO THURSDAY...BUT THERE IS UNCERTAINTY IN HOW LOW CIGS WILL BE INITIALLY. FOR NOW...WILL GO WITH A LOW END VFR CIG AT KMLC AND KFSM AFT 12Z THURSDAY MORNING...WHICH CAN BE ADJUSTED DOWN INTO THE MVFR RANGE IN FUTURE FORECAST UPDATES IF NEED BE. LACY && .PREV DISCUSSION... /ISSUED 955 AM CST WED NOV 19 2014/ DISCUSSION... NW FLOW PREVAILS ALOFT OVER THE PLAINS...ON THE SOUTHWESTERN FRINGE OF A DEEP UPPER TROUGH OVER THE EASTERN CONUS. THE LOW LEVEL THERMAL RIDGE EXTENDS ACROSS OKLAHOMA THIS MORNING IN ADVANCE OF COLD FRONT OVER KANSAS MOVING SOUTH. THUS...THE WIND SHIFT AND ANY COOLING BEHIND THE BOUNDARY WILL BE TOO LITTLE AND TOO LATE TO PREVENT TEMPS FROM RISING ABOVE YESTERDAYS READINGS. IN FACT...THE COLD AIR WITH THIS FRONT SHOULD STAY TO OUR NORTHEAST AS THE UPPER TROUGH IS LIFTING OUT AS WE SPEAK. THUS...THE LATEST HRRR FORECAST HIGH FOR TODAY IS WARMER THAN YESTERDAY AND I HAVE FOLLOWED SUIT WITH THIS FORECAST UPDATE...NUDGING UP HIGHS A COUPLE DEGREES. NO OTHER NOTICEABLE CHANGES WERE MADE TO THE GOING FORECAST. LACY PREV DISCUSSION... /ISSUED 516 AM CST WED NOV 19 2014/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. A WEAK COLD FRONT WILL BRING A WIND SHIFT DURING THE DAY. PREV DISCUSSION... /ISSUED 301 AM CST WED NOV 19 2014/ DISCUSSION... A COLD FRONT STRETCHED ACROSS THE CENTRAL PLAINS WILL WORK ACROSS THE FORECAST AREA THIS AFTERNOON...ALTHOUGH MOST OF THE COLDER LOW-LEVEL AIR WILL REMAIN TO OUR NORTHEAST WITH NOT MUCH MORE THAN A WEAK WIND SHIFT EXPECTED. THAT SAID...FORECAST LOW-LEVEL THERMAL FIELDS SUGGESTS TEMPS A FEW DEGREES WARMER THAN YESTERDAY. THIS MODEST WARMING TREND WILL CONTINUE FOR THE REMAINDER OF THE WEEK...WITH DAYTIME TEMPS RETURNING CLOSER TO SEASONAL NORMS. 1000-850MB MOISTURE WILL INCREASE THURSDAY NIGHT INTO FRIDAY...WITH AREAS OF LIGHT RAIN AND PERHAPS SOME DRIZZLE DEVELOPING AHEAD OF A FAST MOVING UPPER WAVE. A MUCH STRONGER UPPER SYSTEM WILL MOVE FROM THE SWRN STATES FRIDAY AND INTO TX BY SATURDAY...WITH SHOWERS AND EMBEDDED THUNDERSTORMS BECOMING WIDESPREAD ACROSS MOST OF THE AREA SATURDAY MORNING AND INTO THE AFTERNOON. THE BEST CHANCES OF SEVERE WEATHER SHOULD REMAIN WELL SOUTH OF THE AREA...BUT LOCALLY HEAVY RAINFALL WILL BE POSSIBLE GENERALLY ALONG AND EAST OF I-44. PRECIPITATION WILL TAPER OFF SATURDAY NIGHT INTO SUNDAY...WITH COOLER WEATHER EXPECTED GOING INTO EARLY NEXT WEEK. OUTLOOK FOR THANKSGIVING DAY AND BEYOND REMAINS VERY MUCH IN DOUBT AS LATEST ECMWF/GFS ARE COMPLETELY OUT OF PHASE AT THE UPPER LEVELS. THE ECMWF...HOWEVER...REMAINS CONSISTENT WITH ITS PREVIOUS RUNS IN BRINGING ANOTHER SHOT OF MUCH COLDER AIR IN THE THURSDAY/FRIDAY TIMEFRAME. STAY TUNED. && .PRELIMINARY POINT TEMPS/POPS... TUL 54 29 54 40 / 0 0 0 30 FSM 55 30 55 41 / 0 0 10 40 MLC 56 31 59 47 / 0 0 10 40 BVO 52 24 53 36 / 0 0 0 20 FYV 52 23 50 38 / 0 0 0 30 BYV 52 24 50 36 / 0 0 0 30 MKO 55 28 55 42 / 0 0 0 40 MIO 49 23 51 36 / 0 0 0 30 F10 55 30 56 44 / 0 0 0 40 HHW 57 33 60 49 / 0 0 0 40 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...30
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1151 AM CST WED NOV 19 2014 .UPDATE... SURFACE TROUGH AXIS WILL MOVE OVER LAKE MICHIGAN BY THIS AFTERNOON WITH CYCLONIC FLOW OVER SOUTHERN WI. SOUNDINGS FROM THE RAP AND HRRR TO SOME DEGREE INDICATE WEAK OMEGA IN THE DENDRITE GROWTH ZONE THIS AFTERNOON MAINLY IN THE WESTERN CWA. LIGHT SNOW SHOWERS ARE FALLING UPSTREAM IN THE LA CROSSE AREA SO SEEMS THIS LIFT IS ENOUGH TO GENERATE SOME LIGHT SNOW IN THE WESTERN CWA AND FLURRIES ELSEWHERE THIS AFTERNOON. && .AVIATION/18Z TAFS/... UPSTREAM OBS IN THE LA CROSSE AREA INDICATE SOME MVFR CEILINGS WITH SOME LIGHT SNOW SHOWERS OR FLURRIES. FORCING FOR ANY LIGHT SNOW...ESPECIALLY FOR EASTERN TAF SITES...IS MINIMAL. THINK SOME LIGHT SNOW SHOWERS ARE POSSIBLE EARLY THIS AFTERNOON...MAINLY AT KMSN WITH SCATTERED FLURRIES LATER IN THE AFTERNOON. SCATTERED FLURRIES ARE EXPECTED AT EASTERN TAF SITES. VFR/MVFR CEILINGS EXPECTED TO LINGER INTO THURSDAY. WEST WINDS WILL PICK UP THIS AFTERNOON AND WILL REMAIN ELEVATED OVERNIGHT AND THROUGH TOMORROW. && .MARINE... THE SMALL CRAFT ADVISORY CONTINUES THROUGH THURSDAY. GUSTY WEST WINDS ARE EXPECTED TO CONTINUE THROUGH THURSDAY WITH TIGHT PRESSURE GRADIENT AND GOOD LOW LEVEL MIXING. GUSTS UP TO 30 KTS POSSIBLE AT TIMES. HIGHEST WAVES WILL BE TOWARD THE OPEN WATERS WITH THE OFFSHORE FLOW. && .PREV DISCUSSION... /ISSUED 307 AM CST WED NOV 19 2014/ TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH. A BROAD 250 MB UPPER TROUGH EXTENDS ACROSS THE WESTERN GREAT LAKES. LITTLE IN THE WAY OF UPPER DIVERGENCE. A WEAK MID LEVEL 500 MB SHORTWAVE WILL DROP SOUTHEAST ACROSS SOUTHERN WISCONSIN THIS MORNING WITH A STRONGER SHORTWAVE MOVING ACROSS THE LAKE SUPERIOR REGION THIS AFTERNOON. THE 700 MB UPWARD MOTION INCREASES EARLY THIS MORNING WITH DOWNWARD MOTION OVER SOUTH CENTRAL WISCONSIN BEFORE NOON...AND OVER THE SOUTHEAST DURING THE AFTERNOON. ISENTROPIC ANALYSIS SHOWS CONDENSATION PRESSURE DEFICITS FALL TO LESS THAN 10 MB IN THE 780 TO 620 MB LAYER...BUT ONLY FOR A BRIEF TIME... ESPECIALLY AROUND SUNRISE. A WEAK SURFACE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE AREA THIS MORNING. THE MESOSCALE MODELS BRING LIGHT REFLECTIVITY/QPF ACROSS THE AREA...AND KEEP THE BEST VALUES EAST OF THE AREA. NAM FORECAST SOUNDINGS ARE STILL SHOWING ABOUT A 5 TO 6 HOUR WINDOW OF DECENT AIR COLUMN SATURATION WITHIN A 7 THOUSAND FOOT DENDRITE SNOW GROWTH ZONE THIS MORNING. THUS...KEPT THE LIKELY/CATEGORICAL POPS GOING FOR THIS PERIOD...WITH A CHANCE IN THE FAR SOUTHWEST. FLUFFY SNOW ACCUMULATIONS OF MAINLY UP TO 1 INCH ARE EXPECTED IN MOST AREAS...BUT A LITTLE LESS SOUTHWEST OF MADISON. COLD HIGHS IN THE 20S ARE EXPECTED TODAY...WITH BRISK WEST WINDS DEVELOPING IN THE AFTERNOON BEHIND THE TROUGH. THIS WILL BRING SINGLE DIGIT ABOVE ZERO WIND CHILLS LATER IN THE AFTERNOON. WINDS WILL DIMINISH OVER SOUTH CENTRAL WISCONSIN LATE AS A RIDGE OF HIGH PRESSURE APPROACHES FROM THE PLAINS. THURSDAY - CONFIDENCE...MEDIUM UPPER FLOW REMAINS BROADLY CYCLONIC WITH ELONGATED/SHEARED VORT ACROSS THE STATE. MAIN UPPER TROUGH AXIS DOES SHIFT TO THE EASTERN LAKES. LOW LEVEL COLD POOL WILL BE WELL ENTRENCHED WITH 925 TEMPS -13 TO -15C WITH 20-25 KNOTS AT THAT LEVEL AS WELL. MOST HIGHS WILL REMAIN IN THE TEENS. SO EXPECTING A BLUSTERY DAY WITH TEMPS CONTINUING WAY BELOW NORMAL. SURFACE RIDGE AXIS MOVES TO IA THROUGH SRN IL BY DAYS END. THURSDAY NIGHT THROUGH FRIDAY EVENING - CONFIDENCE...HIGH SURFACE HIGH EXPECTED TO DOMINATE THIS PERIOD WITH QUIET WEATHER BUT COLD CONDITIONS PERSISTING. WITH THE RIDGE AXIS BECOMING SITUATED ACROSS THE CWA THURSDAY NIGHT EXPECTING WIDESPREAD SINGLE DIGIT LOWS. THE HIGH SHIFTS INTO THE OHIO VALLEY FRIDAY WITH PRONOUNCED 925/850 WAA RETURN FLOW SETTING UP. 925 TEMPS MODERATE TO -3C TO -6C. SO EXPECT TEMPS TO NUDGE INTO THE MID 20S. THE WAA REGIME CONTINUES INTO FRIDAY EVENING WITH MODELS DELAYING PRECIP ARRIVAL. LATER FRIDAY NIGHT AND SATURDAY MORNING - CONFIDENCE...MEDIUM THIS PERIOD WILL HAVE POTENTIAL FOR MIXY PRECIP DUE THE WARMING ALOFT AND COLDER SURFACE TEMPS SLOWER TO MODERATE. SO AFTER 6Z THROUGH ABOUT 15Z WILL BE THE WINDOW OF CONCERN AS ALL PRECIP TYPES WILL BE POSSIBLE THOUGH GREATEST CONCERN WILL BE THE ELEVATED WARM LAYER AND LACK OF SUSTAINED SATURATION IN THE DENDRIDIC GROWTH ZONE BEARING SOME CONCERN FOR FREEZING RAIN POTENTIAL. QPF AMOUNTS ARE FORECAST TO BE ON THE LOW SIDE. SATURDAY AFTERNOON THROUGH SATURDAY NIGHT - CONFIDENCE...MEDIUM MILDER AIRMASS PROGGD TO BE IN PLACE WITH 850/925 TEMPS WELL ABOVE ZERO CELSIUS. BROAD WAA/MOIST ADVECTION PERSISTS THOUGH BETTER FORCING/BAROCLINICITY LIFTS NORTH AND INTERACTS WITH A NORTHERN STREAM WAVE LIFTING NORTHEAST. QPF AMOUNTS ONLY A FEW HUNDREDTHS. WITH THE SUSTAINED SOUTHWEST LOW LEVEL FLOW MILD TEMPS WILL BE IN PLACE WITH SOME AREAS...ESP IN THE SOUTH POTENTIALLY EXCEEDING 40. SUNDAY AND MONDAY - CONFIDENCE...MEDIUM PRIMARY SURGE OF RAIN ARRIVES WITH POTENT SHORTWAVE LIFTING NORTHEAST FROM THE SOUTHERN PLAINS. STRENGTHENING SURFACE LOW REACHES EITHER NRN IL OR SE WI BY 00Z MON. THE SURFACE LOW LIFTS NORTHEAST WITH COLDER AIR WRAPING IN AROUND THE LOW SUNDAY NIGHT INTO MONDAY. SO EXPECT SOME CHANGEOVER TO OCCUR AS THE PROFILE/COLUMN COOLS. LOW LEVEL TROUGH AND UPPER CYCLONIC FLOW WILL KEEP SNOW SHOWER CHANCES GOING MONDAY WITH SOME LIGHT ACCUMULATION POSSIBLE. TUESDAY - CONFIDENCE...MEDIUM LINGERING CYCLONIC FLOW AND LOW LEVEL TROUGHINESSS SUGGESTS KEEPING SMALL POPS GOING IN THE EAST FOR NOW...PER SUPERBLEND POPS. GFS SHOWS DRY WX WHILE THE ECMWF LINGERS JUST A SMIDGE OF QPF AROUND. AVIATION/12Z TAFS/...AN AREA OF LIGHT SNOW SHOULD SPREAD EAST ACROSS TAF SITES THROUGH 15Z AT MADISON...AND 17Z AT THE EASTERN SITES. VISIBILITIES SHOULD DROP TO NEAR 1 MILE OR NEAR ALTERNATE MINIMUMS DURING THIS TIME...WITH CEILINGS MVFR TO PERHAPS IFR CATEGORY. FLUFFY SNOW ACCUMULATIONS OF 1/2 TO 1 INCH ARE POSSIBLE...WITH 0.1 TO 0.2 INCH RATES PER HOUR. SHOULD SEE VFR CONDITIONS RETURN BY THE AFTERNOON HOURS ON WEDNESDAY...WITH GUSTY WEST WINDS AS WELL. MAY SEE A LITTLE BLOWING AND DRIFTING SNOW...BUT VISIBILITIES SHOULD REMAIN VFR CATEGORY. MARINE...THE PRESSURE GRADIENT AND SUBSEQUENT WINDS WILL WEAKEN THIS MORNING...AS A TROUGH OF LOW PRESSURE MOVES THROUGH THE AREA. GUSTY WEST WINDS ARE EXPECTED AGAIN THIS AFTERNOON AND INTO THURSDAY...AS ANOTHER TIGHT PRESSURE GRADIENT DEVELOPS BEHIND THE DEPARTING LOW. COULD SEE GUSTS TO 30 KNOTS AT TIMES. HIGH WAVES WOULD BE TOWARD AND OVER THE OPEN WATERS WITH THE OFFSHORE FLOW. A SMALL CRAFT ADVISORY IS IN EFFECT DURING THIS PERIOD. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THURSDAY FOR LMZ643>646. && $$ UPDATE...SM/WOOD TODAY/TONIGHT AND AVIATION/MARINE...HENTZ THURSDAY THROUGH TUESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
214 PM MST WED NOV 19 2014 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 214 PM MST WED NOV 19 2014 FAIRLY TRANQUIL WEATHER EXPECTED ACROSS THE CWA FOR MOST OF THIS PERIOD WITH TEMPERATURES RATHER MILD THROUGH SATURDAY. THIS COMPLIMENTS OF AN UPPER RIDGE INITIALLY TO THE WEST THAT WILL MOVE EAST ACROSS THE CWA WHILE WEAKENING OVER THE NEXT COUPLE DAYS. WINDS WILL BE GENERALLY MODEST THROUGH FRIDAY. A WEAK IMPULSE WILL CROSS THE CENTRAL ROCKYS LATE THURSDAY AND COULD BRING A FEW SNOW SHOWERS TO THE HIGHER MTNS AT THAT TIME WITH A ZONAL FLOW SETTING UP OVER THE REGION BEHIND IT FOR FRIDAY. BY LATE FRIDAY A LEE TROUGH IS EXPECTED TO DEVELOP AND DEEPEN OVER THE HIGH PLAINS WHICH WILL INITIATE AN INCREASE IN WINDS AROUND THE MOUNTAINS LATE THAT EVENING...A PRECURSOR OF MORE WIND TO COME. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 214 PM MST WED NOV 19 2014 STRONG WINDS ARE GOING TO BE THE MAIN FORECAST CHALLENGE THROUGH MUCH OF THE EXTENDED PERIOD. STARTING OFF SATURDAY...WEAK SHORTWAVE AND ASSOCIATED COLD FRONT MOVE THROUGH THE AREA THROUGH THE DAY SATURDAY WITH SNOW SHOWERS MAINLY CONFINED TO THE SNOWY AND SIERRA MADRE RANGES. AFTER A FAIRLY WARM DAY SATURDAY...GFS 700MB TEMPERATURES FALL FROM 0 TO+2C SATURDAY AT NOON...DOWN TO -8 TO-10C SUNDAY MORNING. GOING TO BE PRETTY WINDY ONCE THE FRONT MOVES THROUGH THE AREA SATURDAY AFTERNOON. GFS 700MB WINDS PRETTY CLOSE TO 45-50KTS BEHIND THE FRONT WITH 850MB WINDS 35 TO 40KTS OUT IN THE PANHANDLE. 700MB CRAIG TO CASPER GRADIENTS PRETTY STRONG THROUGH THE DAY SATURDAY...STARTING OFF AROUND 990MTRS SATURDAY MORNING...EASING TO 60MTRS SATURDAY NIGHT. WIND HEADLINES FOR THE WIND PRONE AREAS AT LEAST LOOKS LIKE A CERTAINTY. LOOKS LIKE A SLIGHT REPRIEVE SUNDAY AS THE JET DIVES SOUTH INTO SOUTHERN COLORADO AND INTO NEW MEXICO. 700MB WINDS EASE TO 20-30KTS THROUGH THE DAY SUNDAY. WINDY AREA LOOKS TO BE THE PANHANDLE WHERE 850MB WINDS ARE STILL FORECAST AT 35-40KTS THROUGH THE DAY. A MUCH MORE WIDESPREAD AND STRONGER WIND EVENT SUNDAY NIGHT...PERSISTING INTO PROBABLY WEDNESDAY NEXT WEEK. HAVE A SHORTWAVE TRACKING THROUGH MONTANA AND INTO EASTERN WYOMING LATE SUNDAY NIGHT INTO MONDAY AROUND THE LOW OVER THE GREAT LAKES. THIS DRAGS A BACKDOOR COLD FRONT INTO THE NORTHERN PANHANDLE AND NORTHEAST WYOMING BY MONDAY AFTERNOON. OUT WEST IN CARBON AND ALBANY COUNTIES...700MB WINDS ARE INITIALLY 50+KTS MONDAY MORNING. THEN EASE SOME DURING THE LATE MORNING. BY LATE MONDAY AFTERNOON...UPPER SHORTWAVE PASSES TO THE SOUTHEAST WITH THE LONGWAVE RIDGE BUILDING INTO THE AREA. LOOKING AT 60 TO 80 MTR HEIGHT RISES AT 500MB AS THE RIDGE BUILDS INTO SOUTHEAST WYOMING. 700MB WINDS OF 50 TO 60KTS MONDAY EVENING OUT OF THE NORTHWEST. BY TUESDAY AFTERNOON...WINDS TURN MORE WESTERLY AND REALLY BEGIN TO INCREASE. GFS WINDS TUESDAY AFTERNOON APPROACHING 70KT ACROSS THE WESTERN HALF OF THE CWFA WITH 90+MTR 700MB CRAIG TO CASPER GRADIENTS FORECAST. BY WEDNESDAY MORNING...700MB WINDS INCREASE TO 80KTS OVER LARAMIE AND 700MB CRAIG TO CASPER GRADIENTS NEAR 120MTRS. SHOULD SEE WIDESPREAD HIGH WIND HEADLINES IF THIS COMES TRUE FOR BOTH TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 933 AM MST WED NOV 19 2014 VFR CONDITIONS WITH VERY LITTLE IMPACT FROM WEATHER THE NEXT 12 HOURS OR SO. NEED TO WATCH THOUGH THE LOW CLOUDS TO OUR NORTHEAST THIS AFTERNOON AND EVENING AS A WEAK COLD FRONT LAYS OVER WESTERN SOUTH DAKOTA INTO CENTRAL NEBRASKA. LATEST HRRR KEEPS THE LOW CLOUDS EAST AND NORTHEAST OF KCDR THROUGH THE OVERNIGHT HOURS. && .FIRE WEATHER... ISSUED AT 214 PM MST WED NOV 19 2014 NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND WITH WEATHER FACTORS EXPECTED TO BE NON-CRITICAL. BY LATE SATURDAY ONWARD INTO NEXT WEEK STRONG WINDS WILL RETURN TO AREAS ESPECIALLY AROUND THE MOUNTAINS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RE LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
938 AM MST WED NOV 19 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 419 AM MST WED NOV 19 2014 WEST-SOUTHWEST SFC WINDS CONTINUE TO BE A BIT STRONG THIS MORNING IN THE SOUTHERN LARAMIE RANGE AND IN THE ARLINGTON AREA. GUSTS OF 35 TO 50 MPH HAVE BEEN COMMON IN THESE AREAS FOR MUCH OF THE NIGHT...AND EXPECT THESE WINDS TO PERSIST THROUGH AT LEAST MID MORNING. THE UPPER JET WILL MOVE TO THE EAST AND ACROSS THE CWA TODAY WITH WINDS THROUGH THE COLUMN WEAKENING OVERALL THROUGH AFTERNOON. THEREFORE...SHOULD SEE SFC WINDS STEADILY DECREASE THROUGH THE DAY. SATELLITE PICS SHOW STRATUS OVER THE NORTHERN PLAINS STEADILY MOVING SOUTH-SOUTHEAST...WITH FORECAST SOUNDINGS AND BL RH PROGS SHOWING LLVL CLOUDS DEVELOPING THIS MORNING OVER THE PINE RIDGE AND PERSISTING THROUGH MUCH OF THE DAY. THESE LLVL CLOUDS WILL KEEP TEMPS A FEW DEGREES COOLER THAN SURROUNDING LOCATIONS. BROADSCALE SUBSIDENCE IN THE WAKE OF THE DEPARTING JET WILL KEEP PRECIP CHANCES MINIMAL TODAY WITH AREAS OUTSIDE OF THE PINE RIDGE EXPECTED TO REMAIN MILD AS H7 TEMPS INCREASE A FEW DEGREES. NORTHWEST FLOW ALOFT WILL WEAKEN SUBSTANTIALLY AND BECOME MORE ZONAL IN NATURE ON THURSDAY WITH H7 TEMPS INCREASING TO AROUND -1C. THIS SHOULD TRANSLATE TO SFC TEMPS IN THE 40S AND 50S ACROSS THE EASTERN PLAINS AND 30S AND 40S OUT WEST. NAM DOES SHOW THE STRATUS LINGERING OVER THE PINE RIDGE THROUGH THURSDAY AFTERNOON...SO COULD ONCE AGAIN SEE COOLER TEMPS FOR THESE LOCATIONS IF THE STRATUS INDEED PERSISTS. GFS AND WRF BOTH PUSH THE LLVL CLOUDS TO THE EAST LATER TODAY THO...AND WILL TREND TEMPS CLOSER TO THE WARMER AND MORE FAVORABLE SOLUTION. A WEAK SHORTWAVE TROUGH WILL MOVE EAST ACROSS THE ROCKIES THURSDAY NIGHT AND FRIDAY AND WILL CARRY WITH IT SOME PACIFIC MOISTURE. COULD SEE SOME LIGHT SNOW SHOWERS MOVE WEST TO EAST WITH THE WAVE...BUT LIKELY WILL REMAIN CONFINED TO THE MOUNTAINS ON THURSDAY NIGHT WHEN MIDLEVEL ENERGY...MOISTURE AND OROGRAPHIC FORCING WILL FOCUS BEST CHANCE FOR PRECIP. FRIDAY WILL CONTINUE TO BE MILD...WITH TEMPS ACROSS THE PLAINS PEAKING IN THE 50S AS DOWNSLOPE WINDS DEVELOP IN RESPONSE TO THE WAVE MOVING ACROSS AND PRODUCING A LEESIDE PRESSURE TROUGH. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 419 AM MST WED NOV 19 2014 SATURDAY...ONE FINAL MILD DAY IN THE WARM SECTOR AHEAD OF THE APPROACHING COLD FRONT. DECENT ZONAL FLOW ALOFT WILL HELP PRODUCE A WELL DEVELOPED SURFACE LEE TROUGH...WITH DOWNSLOPE WINDS AIDING IN WARMING THE ATMOSPHERE. IF MIDDLE AND HIGH CLOUD OPACITY... THICKNESS...IS LIMITED...EXPECT MAXIMUM TEMPERATURES TO SOAR WELL INTO THE 50S EAST OF INTERSTATE 25...WITH UPPER 30S TO MID 40S WEST OF I-25. BY LATE IN THE DAY...COPIOUS LOW AND MID LEVEL MOISTURE WILL ADVECT INTO OUR SNOWY AND SIERRA MADRE ZONES TO PRODUCE SCATTERED TO WIDESPREAD OROGRAPHIC SNOW SHOWERS THERE...DRY ELSEWHERE. SUNDAY...RATHER STRONG NORTHWEST FLOW ALOFT AND A PASSING SHORTWAVE TROUGH ALOFT WILL SEND A MODERATELY STRONG PACIFIC ORIGIN COLD FRONT ACROSS OUR COUNTIES EARLY. THOUGH THE BULK OF THE QPF IS PROGGED TO MOVE ACROSS COLORADO...WE WILL SEE SCATTERED TO NUMEROUS SNOW SHOWERS OVER OUR SNOWY AND SIERRA MADRE RANGES. LOOKS WINDY PER PROGGED SURFACE THROUGH 700 MB GRADIENTS. MONDAY...OROGRAPHIC SNOW MACHINE WILL CONTINUE IN MOIST NORTHWEST FLOW OVER THE SNOWY AND SIERRA MADRE RANGES...AND WE WILL LIKELY NEED SOME TYPE OF LONG TERM WINTER WEATHER ADVISORY OR WINTER STORM WARNINGS THERE. DRY ELSEWHERE WITH DOWNSLOPE WEST AND NORTHWEST WINDS IN THE LOW AND MID LEVELS. TUESDAY...STRONG NORTHWEST FLOW ALOFT PREVAILS IN THE WAKE OF A PASSING SHORTWAVE TROUGH ALOFT. AS MENTIONED BY THE TUESDAY LONG TERM FORECASTER...WE MAY SEE STRONG WINDS THIS DAY PER PROGGED SURFACE THROUGH 700 MB GRADIENTS AND DEEP UNIDIRECTIONAL NORTHWEST FLOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 933 AM MST WED NOV 19 2014 VFR CONDITIONS WITH VERY LITTLE IMPACT FROM WEATHER THE NEXT 12 HOURS OR SO. && .FIRE WEATHER... ISSUED AT 419 AM MST WED NOV 19 2014 MINIMAL FIRE WEATHER CONCERNS THROUGH THE NEAR TERM DUE TO RELATIVELY COOL TEMPS AND HIGHER HUMIDITIES. NEED TO WATCH THOUGH THE LOW CLOUDS TO OUR NORTHEAST THIS AFTERNOON AND EVENING AS A WEAK COLD FRONT LAYS OVER WESTERN SOUTH DAKOTA INTO CENTRAL NEBRASKA. LATEST HRRR KEEPS THE LOW CLOUDS EAST AND NORTHEAST OF KCDR THROUGH THE OVERNIGHT HOURS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RJM LONG TERM...SAR AVIATION...GCC FIRE WEATHER...RJM