Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/18/16


AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
858 PM MST WED FEB 17 2016 .UPDATE... ISSUED AT 858 PM MST WED FEB 17 2016 EVERYTHING IS ON TRACK FOR A HIGH WIND EVENT IN THE FRONT RANGE MOUNTAINS AND FOOTHILLS...AND POSSIBLY THE ADJACENT PLAINS. LATEST 00Z MODELS SHOW A CORE OF VERY STRONG CORE OF 600 MB WINDS NEAR 65 KNOTS STREAKING NORTHEAST ACROSS THE DESERT AND LIKELY REACHING OUR MOUNTAINS BY 09Z-12Z. BERTHOUD PASS HAS ALREADY SEEN A QUICK INCREASE IN WINDS THIS EVENING WITH GUSTS OF 50-55 KNOTS. AS THIS CORE OF WINDS MOVES IN...EXPECT A FURTHER STRENGTHENING AND RISE INTO HIGH WIND CRITERIA. AS A RESULT...HAVE UPGRADED THE HIGH WIND WATCH TO A WARNING...AND BUMPED UP THE START TIME A COUPLE HOURS. IN THE FOOTHILLS...NOT SURE EXACTLY WHEN THE HIGH WINDS WILL HIT AS THERE IS LITTLE MOUNTAIN WAVE REFLECTION DUE TO LACK OF A MOUNTAIN TOP STABLE LAYER. HOWEVER...LATEST MESOSCALE MODELS INCLUDING THE HRRR...HRRR-EXP...AND RAP SHOW POTENTIAL OF HIGH WIND AS EARLY AS 12Z-15Z. THOSE HIGHER WINDS SHOULD HAVE A TENDENCY OF WORKING DOWN THE FOOTHILLS TOMORROW AS GRADIENT STRENGTHENS. IF THEY DONT TOMORROW...THEN THEY ALMOST CERTAINLY WILL THURSDAY EVENING WITH THE PASSAGE OF THE SHORT WAVE AND STRONG SUBSIDENCE BEHIND IT...SO HAVE UPGRADED THE FOOTHILLS TO HIGH WIND WARNINGS AS WELL. THE LATEST 00Z NAM SHOWS A WIDE AREA OF 60-75 KNOT WINDS AT 700 MB. LOW LEVEL GRADIENTS ARE ALSO VERY TIGHT FOR A 3-6 HOUR PERIOD IN THE EVENING SO HIGH WINDS ARE MORE LIKELY TO SPREAD OUT OF THE FOOTHILLS AND INTO THE LOWER ELEVATIONS. WILL BE ADDING THE NEARBY ADJACENT PLAINS TO A HIGH WIND WATCH FOR THURSDAY NIGHT...WITH THE HIGHEST THREAT OF HIGH WINDS DURING THE EVENING HOURS WITH PASSAGE OF STRONG SUBSIDENCE. CANT EVEN RULE OUT HIGH WINDS FARTHER EAST ON THE PLAINS DUE TO STRENGTH OF SUBSIDENCE AND VERY STRONG GRADIENT. HOWEVER...NIGHT-TIME HOURS ARE NOT AS CONDUCIVE TO HIGH WINDS THERE SO HAVE OPTED TO KEEP THE EASTERN PLAINS OUT OF THE WATCH FOR NOW. FIRE WEATHER WATCH WILL REMAIN IN EFFECT TOMORROW DURING PERIOD OF STRONGER WINDS AND LOWEST HUMIDITIES. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 245 PM MST WED FEB 17 2016 BY EARLY THIS EVENING...MODELS SHOW THE UPPER LEVEL RIDGE AXIS OVER THE FRONT RANGE...RELATIVELY LIGHT ZONAL FLOW ALOFT AND A STRONG MID-LEVEL SUBSIDENCE INVERSION OVER THE AREA. OVERNIGHT RIDGE MIGRATES EAST POSITIONING A STRONGER DEEP LAYER SOUTHWEST FLOW OVER THE STATE. STRONGER S-SWLY SFC WINDS ALSO EXPECTED TO DEVELOP ON THE PLAINS LATE TONIGHT...ESPLY ACRS SERN SECTIONS OF THE CWA WITH A TIGHTENING SFC PRES GRADIENT. ENHANCED DOWNSLOPE FLOW ALONG AND NORTH OF THE PALMER DIVIDE WILL KEEP THE BNDRY LAYER WELL MIXED AND TEMPERATURES QUITE MILD OVERNIGHT. IN THE HIGH COUNTRY...SFC WINDS SHOULD STEADILY INCREASE OVERNIGHT ESPLY ON THE HIGHER PASSES AND ABOVE TIMBERLINE SOUTH OF THE INTERSTATE 70 CORRIDOR. AIRMASS STILL TOO DRY FOR ANY PRECIP TO DEVELOP IN THE HIGH COUNTRY. ON THURSDAY...SWLY FLOW ALOFT STRENGTHENS FURTHER WITH A +160 KT JET ROUNDING THE BOTTOM OF THE APPROACHING UPPER TROUGH. MODELS INDICATE 60-80KT 700-500 MB SWLY FLOW OVER THE FRONT RANGE BY THU EARLY AFTERNOON AND A LARGE WEST-EAST CROSS STATE PRESSURE GRADIENT. MTN TOP SWLY FLOW APPEARS TO MAX OUT IN SPEED WITH PASSAGE OF THE TROUGH AXIS BY AROUND 00Z/FRI. W-SWLY SFC WINDS ON AND NEAR THE FRONT RANGE AND IN THE PALMER DIVIDE AREA SHOULD ALSO PEAK OUT AT THIS TIME. THEN A SHIFT TO PERHAPS AN EVEN STRONGER NWLY FLOW ALOFT BEHIND THE TROUGH AXIS DURING THE EVENING. SEE DETAILS BELOW. AS FOR TEMPS ON THURSDAY...RECORD WARMTH A GOOD BET...ESPLY IN THE VERY WINDY AREAS ALONG THE FOOTHILLS AND OVER THE PALMER DIVIDE. RECORD HIGH AT DENVER IS 71 SET BACK IN 1930. MOS GUIDANCE IS GIVING A HIGH FOR DENVER ANYWHERE FROM 70 TO 75 DEGS. GOING WITH A MAX TEMP A DEG ABOVE THE RECORD. RHS ALSO BECOME QUITE LOW...IN THE 5-15 PCT RANGE EAST OF THE MTNS BY EARLY AFTERNOON WITH HOWLING DOWNSLOPE FLOW. AS HIGHLIGHTS...A FIRE WEATHER WATCH WAS ISSUED EARLIER TODAY FOR THE SRN FRONT RANGE FOOTHILLS AND PALMER DIVIDE AREA. WATCH BEGINS AT 11 AM MST THURSDAY. FOR DETAILS...REFER TO THE FIRE WEATHER WATCH STATEMENT ISSUED AT 924 AM MST THIS MORNING. NEXT...A HIGH WIND WATCH WAS ISSUED FOR THE FRONT RANGE MTNS AND FOOTHILLS. THIS WATCH BEGINS AT 5 AM MST THURSDAY AND RUNS UNTIL 12 NOON MST FRIDAY. FOR DETAILS...REFER TO THE HIGH WIND WATCH STATEMENT ISSUED AT 1020 AM MST THIS MORNING. STATEMENTS WILL LIKELY BE UPDATED WITHIN THE NEXT FEW HOURS. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 PM MST WED FEB 17 2016 MAIN CONCERN IS THE POTENTIAL FOR A HIGH WIND EVENT THURSDAY NIGHT AND FRIDAY MORNING OVER THE HIGH MOUNTAINS AND FRONT RANGE FOOTHILLS. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS COLORADO THURSDAY NIGHT WITH STRONG SUBSIDENCE AND QG DESCENT (+30-50MB/HR) WORKING IN ITS WAKE. APPEARS THE FRONT RANGE FOOTHILLS WILL SEE THE BRUNT OF THE WINDS AS CROSS SECTIONS SHOW 50-60KT CROSS BARRIER FLOW DEVELOPING AFTER 06Z FRIDAY. THE AIRMASS WILL TRANSITION FROM A STRONG BORA COLD ADVECTION THU EVENING TO A CHINOOK EVENT LATER THU NIGHT WITH WARM ADVECTION AT MOUNTAIN TOP. THERE WILL ALSO BE SOME GUSTY WINDS ON THE NORTHEAST PLAINS WITH THE TROF THURSDAY NIGHT BUT NOT ENOUGH FOR HIGH WINDS. THERE WILL ALSO BE A QUICK BATCH OF SNOW OVER THE MOUNTAINS THURSDAY EVENING WITH MODEST INSTABILITY AND OROGRAPHICS. TROF IS MOVING RATHER FAST SO DON`T EXPECT THE SNOW TO LAST MORE THAN 6 HOURS WITH ACCUMULATION OF 2-5 INCHES. WINDS WILL DECREASE FRIDAY AFTERNOON AS STRONGEST SUBSIDENCE MOVES INTO THE CENTRAL PLAINS. TEMPERATURES WILL ALSO BE COOLER ON FRIDAY BEHIND THE TROF. COLORADO WILL REMAIN UNDER A MODERATE WEST TO NORTHWEST FLOW ALOFT THROUGH EARLY NEXT WEEK. THERE IS A STRONGER WAVE IN THE FLOW THAT MOVES ACROSS COLORADO ON MONDAY WITH THE NEXT CHANCE OF SNOW IN THE MOUNTAINS AND COOLER TEMPERATURES. THIS COULD ALSO LEAD TO A SLIGHT CHANCE OF SNOW ON THE PLAINS AS WELL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 858 PM MST WED FEB 17 2016 MAIN CONCERN IS STRENGTH OF WINDS THURSDAY AFTERNOON AND NIGHT. UNTIL THEN...SOUTH/SOUTHWEST WINDS MAY GUST TO AROUND 20 KNOTS AT KAPA AND KDEN THROUGH THURSDAY MORNING WITH STRENGTHENING GRADIENT. MEANWHILE...KBJC WILL SEE LIGHTER WINDS DURING THIS TIME PERIOD WITH WEAK DENVER CYCLONE/CONVERGENCE ZONE IN PLACE. INCREASED MIXING AND MUCH STRONGER FLOW ALOFT WILL BRING AN INCREASE IN WINDS THURSDAY AFTERNOON...BUT TIMING IS IN QUESTION. MORE SUNSHINE IS EXPECTED TO DEVELOP BY AFTERNOON SO GUSTS UP TO 25-32 KNOTS SHOULD BE DEVELOPING OVER THE FRONT RANGE AIRPORTS IN THE 19Z-23Z TIME FRAME. UNTIL THEN...CANT RULE OUT A LULL OF WEAKER EASTERLY WINDS ESPECIALLY AT KBJC AND KDEN IF A BOUNDARY IS ENHANCED ACROSS THE METRO AREA. PEAK WINDS FROM THIS EVENT ARE EXPECTED TO OCCUR 01Z-06Z FRIDAY WHEN STRONGER SUBSIDENCE DEVELOPS BEHIND DEPARTING UPPER LEVEL DISTURBANCE. POTENTIAL FOR GUSTS OF AT LEAST 40 KNOTS AT KDEN AND KAPA AND NEAR 60 KNOTS AT KBJC GIVEN THE STRENGTH OF FLOW ALOFT AND STRONG SUBSIDENCE DEVELOPING. && .FIRE WEATHER... ISSUED AT 245 PM MST WED FEB 17 2016 A FIRE WEATHER WATCH HAS BEEN ISSUED FOR THE SRN FRONT RANGE FOOTHILLS ZONE 216 AND THE PALMER DIVIDE ZONES 241..245...246 AND 247. THIS WATCH WILL START AT 1100 MST ON THURSDAY AND RUN UNTIL 1800 PM MST ON THURSDAY. FOR DETAILS...REFER TO THE FIRE WEATHER WATCH STATEMENT ISSUED AT 924 AM MST THIS MORNING. THE POTENTIAL FOR VERY STRONG WEST-SOUTHWEST WINDS...VERY LOW RELATIVE HUMIDITY AND NEAR RECORD HIGH TEMPERATURES REASONS FOR THE WATCH. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 5 AM THURSDAY TO NOON MST FRIDAY FOR COZ035-036. HIGH WIND WATCH FROM THURSDAY EVENING THROUGH LATE THURSDAY NIGHT FOR COZ038-039. FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR COZ216-241-245>247. HIGH WIND WARNING FROM 3 AM THURSDAY TO NOON MST FRIDAY FOR COZ033-034. && $$ UPDATE...BARJENBRUCH SHORT TERM...BAKER LONG TERM...ENTREKIN AVIATION...BARJENBRUCH FIRE WEATHER...BAKER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
343 PM MST TUE FEB 16 2016 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 340 PM MST TUE FEB 16 2016 STRONG NORTHWEST FLOW /120-130KT MAXIMA/ WAS ANGLING ACRS CNTRL WY/EXTRM NERN CO AND WRN KS AT THIS TIME. CROSS SECTIONS ALSO SHOW AMPLIFICATION OF A LEE SIDE MTN WAVE OVER THE NEXT FEW HOURS AND THE PRESENCE OF A STRONG MTN TOP INVERSION...AS WELL AS MODEST ENHANCEMENT OF THE SFC LEE TROUGH. DO NOT SEE WIND SPEEDS REACHING HIGH WIND CRITERIA WITH THIS SETUP...THOUGH SPEEDS IN A FEW AREAS PRONE TO HIGH WINDS SUCH AS ALONG THE DUMONT- GEORGETOWN STRETCH OF I-70...UP AROUND BERTHOUD PASS...AND THE HIGHER FOOTHILLS WEST OF BOULDER WHERE GUSTS HAVE BEEN OBSERVED IN THE 50-60 KT RANGE TODAY. AT THIS HOUR...WLY WINDS IN THE 30-45 KT IN THE FRONT RANGE FOOTHILLS...AROUND 55 KTS ABOVE TIMBERLINE...AND 25-38 KTS ALONG THE BASE OF THE FOOTHILLS AND UP NEAR THE WYOMING BORDER. TODAY`S RUNS OF THE NAM...WRF...HRRR AND RAP HAVE BEEN HANDLING SPEEDS WELL...BUT THEY`VE NOT BEEN EXTENDING THESE GUSTY CHINOOK WINDS FAR ENOUGH EAST ACROSS THE I-25 URBAN CORRIDOR. OVER THE NEXT SEVERAL HOURS...WITH THE MTN WAVE RELAXING AND THE STRONGER FLOW ALOFT LIFTING AND SHIFTING EAST OF THE CWA...SHOULD SEE WIND SPEEDS LOWERING ON THE PLAINS DURING THE EARLY EVENING HOURS...AND BY AROUND MIDNIGHT/07Z OVER HIGHER EAST SLOPES OF THE FRONT RANGE. W-NWLY WINDS AROUND TIMBERLINE ARE LIKELY TO REMAIN STRONG AND GUSTY ALL NIGHT. WILL INTRODUCE AREAS OF BLOWING SNOW IN MTN AREAS WHERE GUSTS WILL LIKELY EXCEED 30 KTS. OTHERWISE DIMINISHING WINDS ON THE PLAINS SOON AFTER SUNSET AND CLEAR/MOSTLY CLEAR SKIES WILL ALLOW TEMPS TO FALL TO THE 20S AND LOWER 30S BY MORNING. THESE TEMPS STILL 10-18 DEGS F ABOVE AVERAGE. ON WEDNESDAY...LARGE UPPER RIDGE OUT WEST TONIGHT SHIFTS EAST OVER THE ROCKY MTN REGION WITH THE 500 MB RIDGE AXIS SITTING OVER CENTRAL COLORADO BY LATE IN THE DAY. MODERATE TO STRONG NORTHWEST FLOW ALOFT TO START THE DAY WEAKENS AS IT BECOMES ZONAL. THIS IS EXPECTED TO RESULT IN LIGHT SFC WINDS BOTH MTNS AND PLAINS. HOWEVER STRONG PRESSURE FALLS UP IN THE DAKOTAS WILL PROMOTE THE DEVELOPMENT OF GUSTY SLY GRADIENT WINDS OF 15-25 KTS ON THE ERN PLAINS OF COLORADO DURING THE AFTERNOON HOURS. OTHERWISE A WARMER DAY WITH HIGHS ON THE PLAINS GENERALLY 4-8 DEG F WARMER THAN TODAY...AND 2-6 DEG F WARMER IN THE MTNS AND HIGH VALLEYS. KEEP IN MIND...THESE TEMPERATURES ARE 14-20 DEG F ABOVE AVERAGE FOR THE DATE. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 PM MST TUE FEB 16 2016 UPPER LEVEL RIDGE WILL SHIFT EAST OF THE AREA WEDNESDAY NIGHT WHILE A SHORT WAVE TROUGH MOVES ONTO THE CALIFORNIA COAST. THIS WILL PRODUCE A STRONG WEST-SOUTHWEST FLOW ALOFT. AS THE TROUGH NEARS COLORADO THURSDAY...A LEE SIDE SURFACE TROUGH WILL DEEPEN ACROSS THE ROCKY MOUNTAIN REGION. THIS WILL CAUSE WINDS TO INCREASE THROUGH THE DAY. THE DOWNSLOPE WINDS COMBINED WITH THE WARM AIRMASS WILL PUSH HIGHS INTO THE UPPER 60S TO MID 70S. THE RECORD FOR DENVER IS 71 AND THERE IS A GOOD CHANCE IT WILL BE BROKEN. THE TROUGH WILL BRING SHOWERS TO THE MOUNTAINS THURSDAY AFTERNOON AND EVENING. MOST OF THE PRECIPITATION WILL FALL AS SNOW BECAUSE IT QUICKLY COOLS BEHIND THE PACIFIC COLD FRONT. AS THE FRONT RACES EASTWARD...STRONG WINDS ARE EXPECTED TO SPREAD ACROSS THE AREA DURING THE LATE AFTERNOON AND EVENING HOURS. WINDS MAY APPROACH HIGH WIND CRITERIA AND WILL NEED TO BE MONITORED. AIRMASS QUICKLY DRIES BEHIND THE WAVE AND PRECIPITATION WILL END BY MIDNIGHT THURSDAY NIGHT. HIGH PRESSURE WILL SETTLE OVER THE AREA FRIDAY BRINGING LIGHTER WINDS. TEMPERATURES WILL BE COOLER BUT WELL ABOVE AVERAGE STILL. ZONAL FLOW WILL PREVAIL FRIDAY AND SATURDAY. THIS WILL KEEP DRY CONDITIONS OVER THE AREA. MILD TEMPERATURES WILL CONTINUE INTO SATURDAY WITH READINGS CLIMBING INTO THE 60S. FOR SUNDAY AND EARLY NEXT WEEK...UPPER LEVEL RIDGE WILL INTENSIFY OVER THE WESTERN U.S. FLOW ALOFT OVER COLORADO WILL TURN NORTHWESTERLY. A COLD FRONT IS PROGGED TO PUSH THROUGH AND DROP TEMPERATURES TO NEAR NORMAL. RIGHT NOW THE FLOW IS LOOKING DRY AND THE ONLY MENTION OF PRECIPITATION WILL BE CONFINED TO THE MOUNTAINS. THE COOLER TEMPERATURES ARE EXPECTED TO CONTINUE INTO MONDAY. TUESDAY MAY BE WARMER IF THE RIDGE SHIFTS EASTWARD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 340 PM MST TUE FEB 16 2016 STRONG AND GUSTY CHINOOK WINDS WILL CONTINUE TO POTENTIALLY IMPACT DEPARTURES AND LANDINGS AT KBJC NEAR THE FOOTHILLS AT LEAST THROUGH 02Z/WED. WINDS AT THIS TIME NOT AN ISSUE AT KAPA AND KDEN...ALTHOUGH THERE IS STILL A POTENTIAL FOR GUSTY W-NWLY WINDS OF 15-25 KTS AT THESE AIRPORTS UNTIL AROUND SUNSET. WINDS SHOULD THEN TURN S-SWLY AFTER DARK AT KAPA AND KDEN AND REMAIN AT SPEEDS UNDER 13 KTS OVERNIGHT. WINDS AT KBJC SHOULD REMAIN GUSTY AT SPEEDS OF 15-30 KTS AT LEAST THROUGH MID-EVENING...THEN GRADUALLY DROP OFF BELOW 15 KTS BY AROUND MIDNIGHT LST. VFR CONDITIONS ARE TO BE EXPECTED METRO WIDE. ON WEDNESDAY...LOOK FOR S-SWLY WINDS OF 5-12KTS THROUGH MID-MORNING...THEN A WEAK DENVER CYCLONE CENTERED OVER EASTERN SECTIONS OF THE METRO AREA WITH PRODUCE LIGHT N-NELY WINDS OVER WRN SECTIONS OF THE METRO AREA...I.E. KBJC AND S-SELY WINDS OF 10-20 KTS AT KAPA AND KDEN DURING THE AFTERNOON HOURS. VFR CONDITIONS WILL PREVAIL. O && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BAKER LONG TERM...MEIER AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
504 PM EST TUE FEB 16 2016 .SYNOPSIS... A COLD FRONT MOVES ACROSS THE REGION TONIGHT. ANOTHER COLD FRONT CROSSES THE REGION WEDNESDAY NIGHT. A HIGH PRESSURE SYSTEM WILL MOVE EAST ACROSS THE AREA THURSDAY AND THURSDAY NIGHT THEN MOVE OFFSHORE FRIDAY. AS A LOW PRESSURE SYSTEM TRACKS WELL NORTH OF THE AREA...A WARM FRONT WILL MOVE NORTH OF THE AREA FRIDAY NIGHT FOLLOWED BY A COLD FRONT ON SATURDAY. WEAK LOW PRESSURE WILL APPROACH FROM THE WEST AS A COLD FRONT MOVES SOUTHEAST TOWARD THE AREA LATE SUNDAY THROUGH TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... BAND OF HEAVY RAIN HAS QUICKLY RACED EAST ACROSS THE REGION ASSOCIATED WITH STRONG LOW LEVEL JET. WIND GUSTS HAVE GENERALLY BEEN BETWEEN 45 AND 55 MPH WITH SOME ISOLATED TREE AND POWER LINE DAMAGE. THIS LINE WILL BE WELL EAST OF THE CWA BY 22Z. HAVE TRENDED POPS IN THIS DIRECTION FOLLOWING LATEST RADAR TRENDS...HRRR...AND RAP DATA. POPS MAY NEED TO BE FURTHER TRENDED DOWN BASED ON LATEST RADAR TRENDS AND MUCH DRIER AIR MOVING OVER THE WESTERN PORTIONS OF THE CWA. AS THE BAND OF MODERATE TO HEAVY RAIN MOVES EAST OF THE AREA...WINDS WILL SHIFT TO A MORE S OR SSW DIRECTION. GUSTS WILL NOT BE AS STRONG AS LOW LEVEL WINDS ARE WEAKER WITH THE LOW LEVEL JET SHIFTING EAST. COLD FRONT WORKS ITS WAY ACROSS THE CWA THIS EVENING. WINDS WILL SHIFT TO THE W AND NW AND CONTINUE DIMINISH THROUGH THE NIGHT. FOLLOWED A MAV/MET BLEND FOR LOWS WHICH YIELDS READINGS IN THE UPPER 20S ACROSS THE INTERIOR AND LOWER 30S ELSEWHERE. MAY NEED AN SPS FOR BLACK ICE ACROSS INTERIOR PORTIONS OF THE LOWER HUDSON VALLEY FOR SOME ICY SPOTS IF ANY RESIDUAL MOISTURE REMAINS ON AREA ROADWAYS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... SEVERAL SHORTWAVES WILL SWING ACROSS THE REGION ON WEDNESDAY AS MEAN MIDDLE AND UPPER LEVEL TROUGH AXIS WILL STILL BE WEST OF THE REGION. MODEL GUIDANCE IS IN EXCELLENT AGREEMENT WITH THIS PATTERN. THE TROUGH AXIS SHOULD BEGIN TO SWING ACROSS WEDNESDAY NIGHT WITH HEIGHTS ALOFT SLOWLY RISING. HIGH PRESSURE MOVES INTO THE GREAT LAKES DURING THE DAY WITH ANOTHER SURFACE COLD FRONT AHEAD OF IT. THIS COLD FRONT APPROACHES DURING THE DAY AND MOVES THROUGH AT NIGHT. SKIES SHOULD AVERAGE PARTLY CLOUDY WEDNESDAY AND WEDNESDAY NIGHT WITH DRY CONDITIONS FORECAST. ABOVE NORMAL HIGHS IN THE LOWER 40S EXPECTED DURING THE DAY WITH TEMPERATURES FALLING WELL INTO THE 20S AT NIGHT BEHIND THE COLD FRONT. && .LONG TERM /THURSDAY THROUGH TUESDAY/... THURSDAY THROUGH THURSDAY NIGHT...AS A CANADIAN HIGH PRESSURE SYSTEM ADVECTS EAST ACROSS THE AREA FAIR WEATHER WITH SLIGHTLY BELOW NORMAL TEMPERATURES WILL OCCUR WITH DAY TIME HIGHS IN THE 30S AND LOWS FROM THE TEENS THROUGH THE 20S. FRIDAY THROUGH SATURDAY...FORECAST MODELS ALL SHOW LOW PRESSURE TRACKING WELL NORTH OF THE REGION WITH A WARM FRONT MOVING NORTH OF THE AREA AREA FRIDAY NIGHT FOLLOWED BY A COLD FRONT SATURDAY AFTERNOON. WITH LIMITED MOISTURE TO WORK WITH...TEMPERATURES WILL BE COLD ENOUGH FOR SCATTERED PATCHES OF LIGHT SNOW LATE IN THE DAY FRIDAY. AS SFC WINDS INCREASE FROM THE SOUTH FRIDAY NIGHT...THE BOUNDARY LAYER WILL WARM AS SNOW QUICKLY CHANGES TO RAIN ALONG THE COAST FIRST THEN INLAND LATER FRIDAY NIGHT. SCATTERED RAIN SHOWERS ARE FORECAST WITH THE FRONTAL PASSAGE SATURDAY AFTERNOON. SUNDAY THROUGH TUESDAY...FORECAST UNCERTAINTY INCREASES AS SEVERAL WEAK IMPULSES MOVE QUICKLY ALONG THE SOUTHERN EDGE OF THE POLAR JET.TEMPERATURES RETURN TO NEAR NORMAL WITH ONLY LIGHT SCATTERED PRECIPITATION EVENTS. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... A COLD FRONT OVER NYSTATE INTO ERN PA WILL CROSS THE REGION THIS EVE. HIGH PRES BUILDS TOWARDS THE AREA FROM THE MIDWEST ON WED. WINDS WILL SHIFT TO THE W BEHIND THE CDFNT THIS EVE AND COND WILL IMPROVE TO VFR THRU THE NGT. GUSTS DIMINISH AFT 4Z...THEN WLY FLOW INCREASES DURING THE DAY WED. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF WIND SHIFT AND IMPROVEMENT TO VFR. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF WIND SHIFT AND IMPROVEMENT TO VFR. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF WIND SHIFT AND IMPROVEMENT TO VFR. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF WIND SHIFT AND IMPROVEMENT TO VFR. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF WIND SHIFT AND IMPROVEMENT TO VFR. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF WIND SHIFT AND IMPROVEMENT TO VFR. .OUTLOOK FOR 18Z WED THROUGH SUNDAY... .WED-FRI...VFR. .FRI NIGHT...CHANCE OF MIXED PRECIP WITH MVFR OR LOWER CONDS. SW WINDS G20KT LATE. .SAT...CHANCE OF RAIN SHOWERS MVFR OR LOWER CONDS IN THE MORNING. W WINDS G20-25KT. .SUNDAY...VFR. && .MARINE... GALE WARNINGS REMAIN IN EFFECT FOR THE OCEAN AND GREAT SOUTH BAY...AS STRONG SOUTHERLY WIND GUSTS TO 35-40 KT ARE STILL POSSIBLE INTO THIS EVENING. ON ALL OTHER WATERS...25 TO 30 KT GUSTS ARE EXPECTED WITH AN ISOLATED GUST TO 35 KT POSSIBLE. GUSTS SHOULD START TO DIMINISH AS COLD FRONT MOVES THROUGH THIS EVENING. THE GALE WARNING MAY NEED TO BE CANCELLED A BIT EARLIER IF GUSTS FALL OFF QUICKER THAN EXPECTED. THE SCA ON THE HARBOR...PECONIC AND GARDNERS BAYS...AND LONG ISLAND SOUND MAY ALSO NEED TO BE CANCELLED SOONER AS WINDS MAY FALL BELOW 25 KT SOONER THAN 06Z. THEREAFTER...SUB-SCA CONDITIONS ARE FORECAST THROUGH WEDNESDAY NIGHT. ONCE GALES HAVE ENDED ON THE OCEAN THIS EVENING...A SCA WILL BE NEEDED AS SEAS WILL BE MUCH SLOWER TO SUBSIDE. SEAS WELL ABOVE 5 FT ARE LIKELY TO CONTINUE THROUGH WEDNESDAY NIGHT ON THE OCEAN. WINDS ON THE GREAT SOUTH BAY SHOULD SUBSIDE BELOW SCA THIS EVENING. A SMALL CRAFT ADVISORY IS POSSIBLE ON THURSDAY FOR NORTH WINDS OF 15-20 KT WITH GUSTS TO 25 KT WITH THE APPROACH OF A HIGH PRESSURE SYSTEM. FRIDAY NIGHT FOR SOUTHEAST WINDS OF 15-25 KT WITH THE APPROACH OF A WARM FRONT AND SATURDAY FOR SOUTHWEST WINDS OF 15-25 KT WITH THE APPROACH OF A COLD FRONT. && .HYDROLOGY... ONLY LIGHT SCATTERED PRECIPITATION OF LESS THAN 1/4 INCH LIQUID EQUIVALENT IS FORECAST WITH THE PASSAGE OF A WARM FRONT FRIDAY NIGHT FOLLOWED BY A COLD FRONT SATURDAY AFTERNOON.&& .TIDES/COASTAL FLOODING... HAVE CANCELLED THE COASTAL FLOOD ADVISORIES FOR THE SOUTH SHORE BAYS AND EASTERN WATERS OF LONG ISLAND. SURGE HAS NOT BEEN HIGH ENOUGH TO PROMOTE WIDESPREAD MINOR COASTAL FLOODING. A FEW ISOLATED SPOTS COULD BRIEFLY TOUCH MINOR...BUT NO SIGNIFICANT IMPACTS ARE EXPECTED. THE COASTAL FLOOD STATEMENT FOR SW CT COAST REMAINS IN EFFECT...BUT MAY NEED TO BE CANCELLED AS WATER LEVELS SHOULD MOSTLY STAY BELOW MINOR THRESHOLDS. && .TIDES/COASTAL FLOODING... HAVE CANCELLED THE COASTAL FLOOD ADVISORIES FOR THE SOUTH SHORE BAYS AND EASTERN WATERS OF LONG ISLAND. SURGE HAS NOT BEEN HIGH ENOUGH TO PROMOTE WIDESPREAD MINOR COASTAL FLOODING. A FEW ISOLATED SPOTS COULD BRIEFLY TOUCH MINOR...BUT NO SIGNIFICANT IMPACTS ARE EXPECTED. THE COASTAL FLOOD STATEMENT FOR SW CT COAST REMAINS IN EFFECT...BUT MAY NEED TO BE CANCELLED AS WATER LEVELS SHOULD MOSTLY STAY BELOW MINOR THRESHOLDS. && .EQUIPMENT... KOKX RADAR IS OUT OF SERVICE UNTIL FURTHER NOTICE. A PART IS ON ORDER...BUT A RETURN TO SERVICE TIME IS UNKNOWN. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ330-335- 338-340. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ345-350-353- 355. && $$ SYNOPSIS...GC/DS NEAR TERM...DS SHORT TERM...DS LONG TERM...GC AVIATION...JMC/GOODMAN MARINE...GC/DS HYDROLOGY...GC/DS TIDES/COASTAL FLOODING... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
404 PM EST TUE FEB 16 2016 .SYNOPSIS... A COLD FRONT MOVES ACROSS THE REGION TONIGHT. ANOTHER COLD FRONT CROSSES THE REGION WEDNESDAY NIGHT. A HIGH PRESSURE SYSTEM WILL MOVE EAST ACROSS THE AREA THURSDAY AND THURSDAY NIGHT THEN MOVE OFFSHORE FRIDAY. AS A LOW PRESSURE SYSTEM TRACKS WELL NORTH OF THE AREA...A WARM FRONT WILL MOVE NORTH OF THE AREA FRIDAY NIGHT FOLLOWED BY A COLD FRONT ON SATURDAY. WEAK LOW PRESSURE WILL APPROACH FROM THE WEST AS A COLD FRONT MOVES SOUTHEAST TOWARD THE AREA LATE SUNDAY THROUGH TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... BAND OF HEAVY RAIN HAS QUICKLY RACED EAST ACROSS THE REGION ASSOCIATED WITH STRONG LOW LEVEL JET. WIND GUSTS HAVE GENERALLY BEEN BETWEEN 45 AND 55 MPH WITH SOME ISOLATED TREE AND POWER LINE DAMAGE. THIS LINE WILL BE WELL EAST OF THE CWA BY 22Z. HAVE TRENDED POPS IN THIS DIRECTION FOLLOWING LATEST RADAR TRENDS...HRRR...AND RAP DATA. POPS MAY NEED TO BE FURTHER TRENDED DOWN BASED ON LATEST RADAR TRENDS AND MUCH DRIER AIR MOVING OVER THE WESTERN PORTIONS OF THE CWA. AS THE BAND OF MODERATE TO HEAVY RAIN MOVES EAST OF THE AREA...WINDS WILL SHIFT TO A MORE S OR SSW DIRECTION. GUSTS WILL NOT BE AS STRONG AS LOW LEVEL WINDS ARE WEAKER WITH THE LOW LEVEL JET SHIFTING EAST. COLD FRONT WORKS ITS WAY ACROSS THE CWA THIS EVENING. WINDS WILL SHIFT TO THE W AND NW AND CONTINUE DIMINISH THROUGH THE NIGHT. FOLLOWED A MAV/MET BLEND FOR LOWS WHICH YIELDS READINGS IN THE UPPER 20S ACROSS THE INTERIOR AND LOWER 30S ELSEWHERE. MAY NEED AN SPS FOR BLACK ICE ACROSS INTERIOR PORTIONS OF THE LOWER HUDSON VALLEY FOR SOME ICY SPOTS IF ANY RESIDUAL MOISTURE REMAINS ON AREA ROADWAYS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... SEVERAL SHORTWAVES WILL SWING ACROSS THE REGION ON WEDNESDAY AS MEAN MIDDLE AND UPPER LEVEL TROUGH AXIS WILL STILL BE WEST OF THE REGION. MODEL GUIDANCE IS IN EXCELLENT AGREEMENT WITH THIS PATTERN. THE TROUGH AXIS SHOULD BEGIN TO SWING ACROSS WEDNESDAY NIGHT WITH HEIGHTS ALOFT SLOWLY RISING. HIGH PRESSURE MOVES INTO THE GREAT LAKES DURING THE DAY WITH ANOTHER SURFACE COLD FRONT AHEAD OF IT. THIS COLD FRONT APPROACHES DURING THE DAY AND MOVES THROUGH AT NIGHT. SKIES SHOULD AVERAGE PARTLY CLOUDY WEDNESDAY AND WEDNESDAY NIGHT WITH DRY CONDITIONS FORECAST. ABOVE NORMAL HIGHS IN THE LOWER 40S EXPECTED DURING THE DAY WITH TEMPERATURES FALLING WELL INTO THE 20S AT NIGHT BEHIND THE COLD FRONT. && .LONG TERM /THURSDAY THROUGH TUESDAY/... THURSDAY THROUGH THURSDAY NIGHT...AS A CANADIAN HIGH PRESSURE SYSTEM ADVECTS EAST ACROSS THE AREA FAIR WEATHER WITH SLIGHTLY BELOW NORMAL TEMPERATURES WILL OCCUR WITH DAY TIME HIGHS IN THE 30S AND LOWS FROM THE TEENS THROUGH THE 20S. FRIDAY THROUGH SATURDAY...FORECAST MODELS ALL SHOW LOW PRESSURE TRACKING WELL NORTH OF THE REGION WITH A WARM FRONT MOVING NORTH OF THE AREA AREA FRIDAY NIGHT FOLLOWED BY A COLD FRONT SATURDAY AFTERNOON. WITH LIMITED MOISTURE TO WORK WITH...TEMPERATURES WILL BE COLD ENOUGH FOR SCATTERED PATCHES OF LIGHT SNOW LATE IN THE DAY FRIDAY. AS SFC WINDS INCREASE FROM THE SOUTH FRIDAY NIGHT...THE BOUNDARY LAYER WILL WARM AS SNOW QUICKLY CHANGES TO RAIN ALONG THE COAST FIRST THEN INLAND LATER FRIDAY NIGHT. SCATTERED RAIN SHOWERS ARE FORECAST WITH THE FRONTAL PASSAGE SATURDAY AFTERNOON. SUNDAY THROUGH TUESDAY...FORECAST UNCERTAINTY INCREASES AS SEVERAL WEAK IMPULSES MOVE QUICKLY ALONG THE SOUTHERN EDGE OF THE POLAR JET.TEMPERATURES RETURN TO NEAR NORMAL WITH ONLY LIGHT SCATTERED PRECIPITATION EVENTS. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/... A WARM FRONT HAS PASSED TO THE NORTH. MEANWHILE...LOW PRESSURE MOVING FROM NE PA INTO UPSTATE NY AND QUEBEC WILL DRAG A TRAILING COLD FRONT ACROSS EARLY THIS EVENING. NARROW LINE OF LOW-TOPPED CONVECTION...WITHOUT THUNDER BUT WITH VERY HEAVY RAIN...STRONG SFC WINDS AND POSSIBLY SMALL HAIL...WILL MOVE ACROSS THE NYC METRO AND THE LOWER HUDSON VALLEY TERMINALS BETWEEN 19Z-20Z...ACROSS KBDR/KISP 20Z-21Z...AND KGON 21Z-22Z. THIS LINE COULD TAP INTO VERY STRONG WINDS ALOFT THE ARE ALREADY CAUSING LLWS AND PRODUCE BRIEF WIND GUSTS 40-50 KT AND LIFR VSBY. AFTER IT MOVES THROUGH...PREVAILING GUSTY SE FLOW 20-25 KT WITH GUSTS 30-35 KT SHOULD TURN SOUTHERLY AND DIMINISH TO 15-20G25-30KT WITH FLIGHT CAT IMPROVING TO MVFR...THEN SHIFT WNW AFTER COLD FROPA AND DIMINISH FURTHER WITH VFR CONDS. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: PEAK FL020 WINDS 17080KT 18Z-20Z. KLGA FCSTER COMMENTS: PEAK FL020 WINDS 17075KT 18Z-20Z. KEWR FCSTER COMMENTS: PEAK FL020 WINDS 17075KT 18Z-20Z. KTEB FCSTER COMMENTS: PEAK FL020 WINDS 17075KT 18Z-20Z. KHPN FCSTER COMMENTS: PEAK FL020 WINDS 17075KT 18Z-20Z. KISP FCSTER COMMENTS: PEAK FL020 WINDS 17085KT 19Z-21Z. .OUTLOOK FOR 18Z WED THROUGH SUNDAY... .WED-FRI...VFR. .FRI NIGHT...CHANCE OF MIXED PRECIP WITH MVFR OR LOWER CONDS. SW WINDS G20KT LATE. .SAT...CHANCE OF RAIN SHOWERS MVFR OR LOWER CONDS IN THE MORNING. W WINDS G20-25KT. .SUNDAY...VFR. && .MARINE... GALE WARNINGS REMAIN IN EFFECT FOR THE OCEAN AND GREAT SOUTH BAY...AS STRONG SOUTHERLY WIND GUSTS TO 35-40 KT ARE STILL POSSIBLE INTO THIS EVENING. ON ALL OTHER WATERS...25 TO 30 KT GUSTS ARE EXPECTED WITH AN ISOLATED GUST TO 35 KT POSSIBLE. GUSTS SHOULD START TO DIMINISH AS COLD FRONT MOVES THROUGH THIS EVENING. THE GALE WARNING MAY NEED TO BE CANCELLED A BIT EARLIER IF GUSTS FALL OFF QUICKER THAN EXPECTED. THE SCA ON THE HARBOR...PECONIC AND GARDNERS BAYS...AND LONG ISLAND SOUND MAY ALSO NEED TO BE CANCELLED SOONER AS WINDS MAY FALL BELOW 25 KT SOONER THAN 06Z. THEREAFTER...SUB-SCA CONDITIONS ARE FORECAST THROUGH WEDNESDAY NIGHT. ONCE GALES HAVE ENDED ON THE OCEAN THIS EVENING...A SCA WILL BE NEEDED AS SEAS WILL BE MUCH SLOWER TO SUBSIDE. SEAS WELL ABOVE 5 FT ARE LIKELY TO CONTINUE THROUGH WEDNESDAY NIGHT ON THE OCEAN. WINDS ON THE GREAT SOUTH BAY SHOULD SUBSIDE BELOW SCA THIS EVENING. A SMALL CRAFT ADVISORY IS POSSIBLE ON ...THURSDAY FOR NORTH WINDS OF 15-20 KT WITH GUSTS TO 25 KT WITH THE APPROACH OF A HIGH PRESSURE SYSTEM. ...FRIDAY NIGHT FOR SOUTHEAST WINDS OF 15-25 KT WITH THE APPROACH OF A WARM FRONT AND ...SATURDAY FOR SOUTHWEST WINDS OF 15-25 KT WITH THE APPROACH OF A COLD FRONT. && .HYDROLOGY... ONLY LIGHT SCATTERED PRECIPITATION OF LESS THAN 1/4 INCH LIQUID EQUIVALENT IS FORECAST WITH THE PASSAGE OF A WARM FRONT FRIDAY NIGHT FOLLOWED BY A COLD FRONT SATURDAY AFTERNOON.&& .TIDES/COASTAL FLOODING... HAVE CANCELLED THE COASTAL FLOOD ADVISORIES FOR THE SOUTH SHORE BAYS AND EASTERN WATERS OF LONG ISLAND. SURGE HAS NOT BEEN HIGH ENOUGH TO PROMOTE WIDESPREAD MINOR COASTAL FLOODING. A FEW ISOLATED SPOTS COULD BRIEFLY TOUCH MINOR...BUT NO SIGNIFICANT IMPACTS ARE EXPECTED. THE COASTAL FLOOD STATEMENT FOR SW CT COAST REMAINS IN EFFECT...BUT MAY NEED TO BE CANCELLED AS WATER LEVELS SHOULD MOSTLY STAY BELOW MINOR THRESHOLDS. && .EQUIPMENT... KOKX RADAR IS OUT OF SERVICE UNTIL FURTHER NOTICE. A PART IS ON ORDER...BUT A RETURN TO SERVICE TIME IS UNKNOWN. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ330-335- 338-340. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ345-350-353- 355. && $$ SYNOPSIS...GC/DS NEAR TERM...DS SHORT TERM...DS LONG TERM...GC AVIATION...GOODMAN MARINE...GC/DS HYDROLOGY...GC/DS TIDES/COASTAL FLOODING... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
120 PM EST TUE FEB 16 2016 .SYNOPSIS... LOW PRESSURE TRACKS WEST OF THE APPALACHIANS TODAY BEFORE MOVING INTO EASTERN CANADA BY THIS EVENING. A COLD FRONT MOVES ACROSS THE REGION TONIGHT. ANOTHER COLD FRONT APPROACHES FROM THE NORTHWEST ON WEDNESDAY...THEN CROSSES THE TRI-STATE WEDNESDAY NIGHT. CANADIAN HIGH PRESSURE BUILDS IN THROUGH THURSDAY NIGHT...THEN SLIDES OFFSHORE ON FRIDAY. A WARM FRONT APPROACHES FROM THE SOUTHWEST FRIDAY NIGHT...THEN LIFTS TO THE NORTH ON SATURDAY...FOLLOWED BY A COLD FRONTAL PASSAGE INTO SATURDAY NIGHT. WEAK HIGH PRESSURE BUILDS IN ON SUNDAY. A COMPLEX STORM SYSTEM IMPACTS THE AREA SUNDAY NIGHT AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... REGION WELL INTO THE WARM SECTOR EARLY THIS AFTERNOON. BAND OF MODERATE TO HEAVY RAINFALL APPROACHING FROM THE WEST ASSOCIATED WITH DEEPENING LOW PRESSURE MOVING FROM CENTRAL PA INTO UPSTATE NEW YORK. WITHIN THE BAND OF RAIN IS A FINE LINE OF HEAVY RAINFALL STRETCHING FROM SE PA THROUGH SOUTHERN NJ. ALONG AND AHEAD OF THE FINE LINE IS VERY STRONG WINDS JUST ABOVE THE SURFACE. LOW LEVEL JET AT 925 MB PROGGED BY THE NAM TO BE BETWEEN 80 AND 85 KT ACROSS LONG ISLAND AND SOUTHERN CT THIS AFTERNOON. HAVE SEEN A FEW OBSERVATIONS OF GUSTS CLOSE TO 50 MPH ALONG AND JUST AHEAD OF THIS FINE LINE. LATEST RADAR TRENDS TAKE IT INTO THE NYC/NJ METRO AROUND 19Z. ANY STRONG WIND GUST POTENTIAL WILL BE HANDLED WITH SHORT FUSED PRODUCTS. ONCE THE LINE MOVES THROUGH...WINDS WILL SHIFT TO MORE OF A SOUTH OR SOUTHWEST DIRECTION WITH SPEEDS DECREASING AS THE LOW LEVEL JET MOVES EAST. HAVE UPDATED POPS AND WX GRIDS...WITH INCREASED EMPHASIS ON GUSTY WIND POTENTIAL AND THE ADDITION OF ISOLATED THUNDER. LIMITED CAPE...BUT WITH STRONG LOW LEVEL JET AND STRONG FORCING...IT WOULD NOT BE OUT OF THE QUESTION FOR A FEW RUMBLES OF THUNDER. POPS TRENDED SIGNIFICANTLY DOWNWARD ONCE THE RAIN MOVES EAST. BLENDED LATEST HRRR AND RAP POPS. IN GENERAL...AROUND 1" OF LIQUID PRECIPITATION IS FORECAST WITH LOCALLY HIGHER AMOUNTS. NOT EXPECTING FLASH FLOODING...BUT MINOR URBAN FLOODING DUE TO EXCESS RUNOFF AND MINOR RISES IN AREA RIVERS ARE POSSIBLE. COLD FRONT WORKS ITS WAY ACROSS THE CWA THIS EVENING. WINDS SHIFT TO THE NW AND DIMINISH FAIRLY QUICKLY...BECOMING LESS THAN 10 MPH THIS EVENING. WITH COLD AIR ADVECTION UNDERWAY...LOWS TONIGHT WILL DROP INTO THE UPPER 20S INLAND TO THE MID 30S NEAR THE COAST. WITH RESIDUAL MOISTURE ON ROADWAYS...SOME ICY SPOTS MAY DEVELOP THIS EVENING...ESPECIALLY ACROSS INTERIOR PORTIONS OF THE LOWER HUDSON VALLEY. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... MEAN TROUGHING BUILDS INTO THE EASTERN U.S. WEDNESDAY AND WEDNESDAY NIGHT...THEN SLIDES OFFSHORE ON THURSDAY. LOW LEVELS SHOULD BE FAIRLY DRY...SO OUTSIDE OF SLIGHT CHANCE POPS OVER FAR W ORANGE COUNTY FOR SNOW SHOWERS (COULD SEE SOME ENHANCEMENT OF LOW LEVEL MOISTURE FROM THE GREAT LAKES THERE) ON WEDNESDAY...HAVE GONE DRY IN THIS TIME FRAME. DEEP LAYERED RIDGING BUILDS IN THURSDAY NIGHT...SO HAVE GONE DRY THEN AS WELL. FOR HIGHS WEDNESDAY...A BLEND OF MAV/MET/ECS GUIDANCE...A MIX DOWN FROM 925 HPA...AND NAM 2-METER TEMPERATURES WAS USED. A BLEND OF MAV/ECS/MET GUIDANCE AND NAM 2-METER TEMPERATURES WAS USED FOR LOWS WEDNESDAY NIGHT. READINGS ARE FORECAST TO BE NEAR TO SLIGHTLY ABOVE NORMAL IN BOTH PERIODS. FOR HIGHS THURSDAY...A BLEND OF MET/MET GUIDANCE...NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 900 HPA WAS USED. A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE AND NAM 2-METER TEMPERATURES WAS USED FOR LOWS THURSDAY NIGHT. VALUES SHOULD BE AROUND 5 DEGREES BELOW NORMAL FOR BOTH PERIODS. && .LONG TERM /FRIDAY THROUGH MONDAY/... A DEEP LAYERED RIDGE SLIDES TO THE EAST ON FRIDAY...WITH ASSOCIATED SUBSIDENCE KEEPING THINGS DRY. MULTIPLE NORTHERN STREAM SHORTWAVES APPROACH FRIDAY NIGHT...THEN PASS TO THE EAST ON SATURDAY. HAVE CHANCE POPS EVERYWHERE FRIDAY NIGHT...FOR A RAIN/SNOW MIX ACROSS SOUTHERN ZONES...AND A WINTRY MIX TO SNOW FOR NORTHERN ZONES. ON SATURDAY...HAVE SLIGHT CHANCE POPS WEST 1/3 AS SHORTWAVES APPEAR TO EXIT FAIRLY QUICKLY SATURDAY MORNING...WITH CHANCE POPS ELSEWHERE. PRECIPITATION CHANGES TO ALL RAIN THROUGHOUT BY AFTERNOON. SHORTWAVE 700-500 HPA RIDGING CROSSES THE AREA SATURDAY NIGHT...FOLLOWED BY A WEAK SHORT WAVE PASSING ON SUNDAY. THERE IS SOME DIFFERENCES IN TIMING OF THESE FEATURES...BUT WITH DRY LOW LEVELS...FOR NOW EXPECT THE SHORTWAVE TO PASS THROUGH DRY...SO HAVE GONE WITH A DRY FORECAST FOR BOTH PERIODS. THERE ARE DIFFERENCES IN THE HANDLING OF THE NEXT SYSTEM FOR SUNDAY NIGHT/MONDAY BETWEEN THE ECMWF AND GFS/CMC/GEFS MEAN...SO LEANED TOWARDS THE LARGER CONSENSUS IN THIS TIME FRAME...WITH ONLY SLIGHT CHANCE POPS SUNDAY NIGHT AND CHANCE POPS ON MONDAY. AT THIS TIME IT APPEARS TO BE MAINLY A RAIN EVENT...WITH MAYBE SOME MIXING IN OF SNOW OVER FAR NW ZONES. HOWEVER...GIVEN THE HIGH DEGREE OF UNCERTAINTY ON THE EVOLUTION OF THE SYSTEM...THIS IS COULD CHANGE. FOR TEMPERATURES FRIDAY-MONDAY THE SUPER BLEND WAS USED...WITH BELOW NORMAL TEMPERATURES FRIDAY...GIVING WAY TO ABOVE NORMAL TEMPERATURES FOR THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... A WARM FRONT HAS PASSED TO THE NORTH. MEANWHILE...LOW PRESSURE MOVING FROM NE PA INTO UPSTATE NY AND QUEBEC WILL DRAG A TRAILING COLD FRONT ACROSS EARLY THIS EVENING. NARROW LINE OF LOW-TOPPED CONVECTION...WITHOUT THUNDER BUT WITH VERY HEAVY RAIN...STRONG SFC WINDS AND POSSIBLY SMALL HAIL...WILL MOVE ACROSS THE NYC METRO AND THE LOWER HUDSON VALLEY TERMINALS BETWEEN 19Z-20Z...ACROSS KBDR/KISP 20Z-21Z...AND KGON 21Z-22Z. THIS LINE COULD TAP INTO VERY STRONG WINDS ALOFT THE ARE ALREADY CAUSING LLWS AND PRODUCE BRIEF WIND GUSTS 40-50 KT AND LIFR VSBY. AFTER IT MOVES THROUGH...PREVAILING GUSTY SE FLOW 20-25 KT WITH GUSTS 30-35 KT SHOULD TURN SOUTHERLY AND DIMINISH TO 15-20G25-30KT WITH FLIGHT CAT IMPROVING TO MVFR...THEN SHIFT WNW AFTER COLD FROPA AND DIMINISH FURTHER WITH VFR CONDS. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: PEAK FL020 WINDS 17080KT 18Z-20Z. KLGA FCSTER COMMENTS: PEAK FL020 WINDS 17075KT 18Z-20Z. KEWR FCSTER COMMENTS: PEAK FL020 WINDS 17075KT 18Z-20Z. KTEB FCSTER COMMENTS: PEAK FL020 WINDS 17075KT 18Z-20Z. KHPN FCSTER COMMENTS: PEAK FL020 WINDS 17075KT 18Z-20Z. KISP FCSTER COMMENTS: PEAK FL020 WINDS 17085KT 19Z-21Z. .OUTLOOK FOR 18Z WED THROUGH SUNDAY... .WED-FRI...VFR. .FRI NIGHT...CHANCE OF MIXED PRECIP WITH MVFR OR LOWER CONDS. SW WINDS G20KT LATE. .SAT...CHANCE OF RAIN SHOWERS MVFR OR LOWER CONDS IN THE MORNING. W WINDS G20-25KT. .SUNDAY...VFR. && .MARINE... THE FORECAST REMAINS ON TRACK THIS AFTERNOON. GALE WARNINGS REMAIN IN EFFECT FOR THE OCEAN AND GREAT SOUTH BAY...AS STRONG SOUTHERLY WINDS WILL GUST TO 35-40 KT...POSSIBLY AS HIGH AS 45 KT ON THE OPEN ATLANTIC OCEAN WATERS. ON ALL OTHER WATERS...A FEW GUSTS TO 35 KT ARE POSSIBLE...BUT THINK MOST OF THE GUSTS WILL TOP OFF AROUND 30 KT. WITH THE STORM DEPARTING THIS EVENING...WINDS WILL DIMINISH FAIRLY QUICKLY...AND SUB-SCA CONDITIONS LIKELY ON MOST WATERS BEFORE MIDNIGHT TONIGHT. OCEAN SEAS WILL REMAIN HIGH...AND SCA WILL LIKELY BE NEEDED FOR THOSE WATERS WHEN THE GALES END. SEAS SHOULD REMAIN ABOVE SMALL CRAFT LEVELS ON THE COASTAL OCEAN WATERS ON WEDNESDAY...WITH SUB-SMALL CRAFT CONDITIONS ON THE NON- OCEAN WATERS. WINDS INCREASE WEDNESDAY NIGHT AND THURSDAY IN RESPONSE TO COLD AIR ADVECTION...WITH SMALL CRAFT CONDITIONS LIKELY ON THE COASTAL OCEAN WATERS AND POSSIBLE ON THE NON-OCEAN WATERS. WINDS ON THE NON-OCEAN WATERS SHOULD BE 15 KT OR LESS THURSDAY NIGHT-SATURDAY. ON THE COASTAL OCEAN WATERS SMALL CRAFT CONDITIONS ARE LIKELY IN THIS TIME FRAME DUE TO BOTH WIND GUSTS TO AROUND 25 KT AND SEAS 5 FT OR GREATER. && .HYDROLOGY... A TOTAL OF AROUND 1 INCH OF LIQUID PRECIPITATION...WITH LOCALLY HIGHER AMOUNTS POSSIBLE...IS EXPECTED THROUGH THIS EVENING. HEAVY RAIN MAY LEAD TO URBAN AND POOR DRAINAGE ISSUES. SOME SMALLER AND FASTER REACTING STREAMS ACROSS NORTHEASTERN NEW JERSEY MAY APPROACH BANKFULL THIS AFTERNOON. NO SIGNIFICANT PRECIPITATION IS EXPECTED FROM WEDNESDAY INTO SUNDAY. && .TIDES/COASTAL FLOODING... A COASTAL FLOOD ADVISORY REMAINS UP FOR THE SOUTH SHORE BAYS OF NASSAU AND SUFFOLK COUNTIES FOR THE HIGH TIDE CYCLE THIS AFTERNOON AND EVENING. TIDES ARE ASTRONOMICALLY LOW...BEING BETWEEN A NEW AND FULL MOON. THE HIGH TIDE CYCLE THIS AFTERNOON AND EVENING WILL COINCIDE WITH A PROLONGED PERIOD OF STRONG SE WINDS AND THE HIGHEST SURGE. SURGE VALUES OF 2 1/2 TO 3 FT WILL BE SUFFICIENT FOR MINOR COASTAL FLOODING ACROSS THE SOUTH SHORE BACK BAYS OF LONG ISLAND AS WELL AS LOCATIONS ADJACENT TO PECONIC AND GARDINERS BAYS. WATER LEVELS LOOK TO FALL JUST SHY OF MINOR FLOOD BENCHMARKS AT THE NYC SOUTH SHORE BAYS. WILL GO AHEAD AND ISSUE A COASTAL FLOOD STATEMENT FOR THE CT COAST FOR THE LATE AFTERNOON/EARLY EVENING HIGH TIDE CYCLE...AS THE STRONG SOUTHERLY WINDS MAY RESULT IN LOCALIZED MINOR COASTAL FLOODING. && .EQUIPMENT... KOKX RADAR IS OUT OF SERVICE UNTIL FURTHER NOTICE. A PART IS ON ORDER...BUT A RETURN TO SERVICE TIME IS UNKNOWN. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...COASTAL FLOOD ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ080- 179. COASTAL FLOOD ADVISORY UNTIL 8 PM EST THIS EVENING FOR NYZ079- 081. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ330-335- 338-340. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ345-350-353- 355. && $$ SYNOPSIS...MALOIT/MPS NEAR TERM...DS SHORT TERM...MPS LONG TERM...MALOIT AVIATION...GOODMAN MARINE...MALOIT/MPS/DS HYDROLOGY...MALOIT/MPS TIDES/COASTAL FLOODING... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1257 PM EST TUE FEB 16 2016 .SYNOPSIS... LOW PRESSURE TRACKS WEST OF THE APPALACHIANS TODAY BEFORE MOVING INTO EASTERN CANADA BY THIS EVENING. A COLD FRONT MOVES ACROSS THE REGION TONIGHT. ANOTHER COLD FRONT APPROACHES FROM THE NORTHWEST ON WEDNESDAY...THEN CROSSES THE TRI-STATE WEDNESDAY NIGHT. CANADIAN HIGH PRESSURE BUILDS IN THROUGH THURSDAY NIGHT...THEN SLIDES OFFSHORE ON FRIDAY. A WARM FRONT APPROACHES FROM THE SOUTHWEST FRIDAY NIGHT...THEN LIFTS TO THE NORTH ON SATURDAY...FOLLOWED BY A COLD FRONTAL PASSAGE INTO SATURDAY NIGHT. WEAK HIGH PRESSURE BUILDS IN ON SUNDAY. A COMPLEX STORM SYSTEM IMPACTS THE AREA SUNDAY NIGHT AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... REGION WELL INTO THE WARM SECTOR EARLY THIS AFTERNOON. BAND OF MODERATE TO HEAVY RAINFALL APPROACHING FROM THE WEST ASSOCIATED WITH DEEPENING LOW PRESSURE MOVING FROM CENTRAL PA INTO UPSTATE NEW YORK. WITHIN THE BAND OF RAIN IS A FINE LINE OF HEAVY RAINFALL STRETCHING FROM SE PA THROUGH SOUTHERN NJ. ALONG AND AHEAD OF THE FINE LINE IS VERY STRONG WINDS JUST ABOVE THE SURFACE. LOW LEVEL JET AT 925 MB PROGGED BY THE NAM TO BE BETWEEN 80 AND 85 KT ACROSS LONG ISLAND AND SOUTHERN CT THIS AFTERNOON. HAVE SEEN A FEW OBSERVATIONS OF GUSTS CLOSE TO 50 MPH ALONG AND JUST AHEAD OF THIS FINE LINE. LATEST RADAR TRENDS TAKE IT INTO THE NYC/NJ METRO AROUND 19Z. ANY STRONG WIND GUST POTENTIAL WILL BE HANDLED WITH SHORT FUSED PRODUCTS. ONCE THE LINE MOVES THROUGH...WINDS WILL SHIFT TO MORE OF A SOUTH OR SOUTHWEST DIRECTION WITH SPEENDS DECREASING AS THE LOW LEVEL JET MOVES EAST. HAVE UPDATED POPS AND WX GRIDS...WITH INCREASED EMPHASIS ON GUSTY WIND POTENTIAL AND THE ADDITION OF ISOLATED THUNDER. LIMITED CAPE...BUT WITH STRONG LOW LEVEL JET AND STRONG FORCING...IT WOULD NOT BE OUT OF THE QUESTION FOR A FEW RUMBLES OF THUNDER. POPS TRENDED SIGNIFICANTLY DOWNWARD ONCE THE RAIN MOVES EAST. BLENDED LATEST HRRR AND RAP POPS. IN GENERAL...AROUND 1" OF LIQUID PRECIPITATION IS FORECAST WITH LOCALLY HIGHER AMOUNTS. NOT EXPECTING FLASH FLOODING...BUT MINOR URBAN FLOODING DUE TO EXCESS RUNOFF AND MINOR RISES IN AREA RIVERS ARE POSSIBLE. COLD FRONT WORKS ITS WAY ACROSS THE CWA THIS EVENING. WINDS SHIFT TO THE NW AND DIMINISH FAIRLY QUICKLY...BECOMING LESS THAN 10 MPH THIS EVENING. WITH COLD AIR ADVECTION UNDERWAY...LOWS TONIGHT WILL DROP INTO THE UPPER 20S INLAND TO THE MID 30S NEAR THE COAST. WITH RESIDUAL MOISTURE ON ROADWAYS...SOME ICY SPOTS MAY DEVELOP THIS EVENING...ESPECIALLY ACROSS INTERIOR PORTIONS OF THE LOWER HUDSON VALLEY. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... MEAN TROUGHING BUILDS INTO THE EASTERN U.S. WEDNESDAY AND WEDNESDAY NIGHT...THEN SLIDES OFFSHORE ON THURSDAY. LOW LEVELS SHOULD BE FAIRLY DRY...SO OUTSIDE OF SLIGHT CHANCE POPS OVER FAR W ORANGE COUNTY FOR SNOW SHOWERS (COULD SEE SOME ENHANCEMENT OF LOW LEVEL MOISTURE FROM THE GREAT LAKES THERE) ON WEDNESDAY...HAVE GONE DRY IN THIS TIME FRAME. DEEP LAYERED RIDGING BUILDS IN THURSDAY NIGHT...SO HAVE GONE DRY THEN AS WELL. FOR HIGHS WEDNESDAY...A BLEND OF MAV/MET/ECS GUIDANCE...A MIX DOWN FROM 925 HPA...AND NAM 2-METER TEMPERATURES WAS USED. A BLEND OF MAV/ECS/MET GUIDANCE AND NAM 2-METER TEMPERATURES WAS USED FOR LOWS WEDNESDAY NIGHT. READINGS ARE FORECAST TO BE NEAR TO SLIGHTLY ABOVE NORMAL IN BOTH PERIODS. FOR HIGHS THURSDAY...A BLEND OF MET/MET GUIDANCE...NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 900 HPA WAS USED. A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE AND NAM 2-METER TEMPERATURES WAS USED FOR LOWS THURSDAY NIGHT. VALUES SHOULD BE AROUND 5 DEGREES BELOW NORMAL FOR BOTH PERIODS. && .LONG TERM /FRIDAY THROUGH MONDAY/... A DEEP LAYERED RIDGE SLIDES TO THE EAST ON FRIDAY...WITH ASSOCIATED SUBSIDENCE KEEPING THINGS DRY. MULTIPLE NORTHERN STREAM SHORTWAVES APPROACH FRIDAY NIGHT...THEN PASS TO THE EAST ON SATURDAY. HAVE CHANCE POPS EVERYWHERE FRIDAY NIGHT...FOR A RAIN/SNOW MIX ACROSS SOUTHERN ZONES...AND A WINTRY MIX TO SNOW FOR NORTHERN ZONES. ON SATURDAY...HAVE SLIGHT CHANCE POPS WEST 1/3 AS SHORTWAVES APPEAR TO EXIT FAIRLY QUICKLY SATURDAY MORNING...WITH CHANCE POPS ELSEWHERE. PRECIPITATION CHANGES TO ALL RAIN THROUGHOUT BY AFTERNOON. SHORTWAVE 700-500 HPA RIDGING CROSSES THE AREA SATURDAY NIGHT...FOLLOWED BY A WEAK SHORT WAVE PASSING ON SUNDAY. THERE IS SOME DIFFERENCES IN TIMING OF THESE FEATURES...BUT WITH DRY LOW LEVELS...FOR NOW EXPECT THE SHORTWAVE TO PASS THROUGH DRY...SO HAVE GONE WITH A DRY FORECAST FOR BOTH PERIODS. THERE ARE DIFFERENCES IN THE HANDLING OF THE NEXT SYSTEM FOR SUNDAY NIGHT/MONDAY BETWEEN THE ECMWF AND GFS/CMC/GEFS MEAN...SO LEANED TOWARDS THE LARGER CONSENSUS IN THIS TIME FRAME...WITH ONLY SLIGHT CHANCE POPS SUNDAY NIGHT AND CHANCE POPS ON MONDAY. AT THIS TIME IT APPEARS TO BE MAINLY A RAIN EVENT...WITH MAYBE SOME MIXING IN OF SNOW OVER FAR NW ZONES. HOWEVER...GIVEN THE HIGH DEGREE OF UNCERTAINTY ON THE EVOLUTION OF THE SYSTEM...THIS IS COULD CHANGE. FOR TEMPERATURES FRIDAY-MONDAY THE SUPER BLEND WAS USED...WITH BELOW NORMAL TEMPERATURES FRIDAY...GIVING WAY TO ABOVE NORMAL TEMPERATURES FOR THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... A WARM FRONT HAS PASSED TO THE NORTH. MEANWHILE...LOW PRESSURE MOVING FROM CENTRAL PA INTO UPSTATE NY AND QUEBEC WILL DRAG A TRAILING COLD FRONT ACROSS EARLY THIS EVENING. WIDELY VARYING CONDITIONS LATE THIS MORNING...WITH PREVAILING IFR AT KHPN/KSWF AND MOST INLAND SECTIONS...MVFR WITH PASSING SHOWERS AT MOST OF THE NYC METRO TERMINALS...AND VFR TO THE EAST. A PRE- FRONTAL RAIN BAND WILL MOVE IN AHEAD OF THE APPROACHING COLD FRONT LATE THIS AFTERNOON AND EARLY THIS EVENING...WITH PREVAILING IFR CONDS AND TEMPO LIFR IN HEAVY RAIN. EXPECT GUSTY SSE WINDS AHEAD OF AND WITH THE RAIN BAND...AS WELL AS LLWS. WINDS AT FL020 WILL BE AS HIGH AS BE 80-85 KT...BUT THINK ACTUAL LLWS WILL OCCUR MUCH CLOSER TO GROUND LEVEL WITH SPEEDS 55-65 KT...HIGHEST AT KJFK/KISP AND LOWER INLAND. THERE IS A CHANCE SOME OF THESE VERY STRONG WINDS COULD BE TRANSPORTED DOWN TO THE SURFACE IN HEAVIER RAIN. MVFR CONDS COULD LINGER FOR A COUPLE OF HRS THIS EVENING BETWEEN PASSAGE OF THE RAIN BAND AND THE COLD FRONT...THEN VFR WITH WINDS SHIFTING WSW TO W AFTER FROPA THIS EVENING. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: PEAK FL020 WINDS 17080KT AND BRIEF SFC WND G45KT POSSIBLE WITH HEAVIER RAIN 18Z-20Z. KLGA FCSTER COMMENTS: PEAK FL020 WINDS 17075KT AND BRIEF SFC WND G40KT POSSIBLE WITH HEAVIER RAIN 18Z-20Z. KEWR FCSTER COMMENTS: PEAK FL020 WINDS 17075KT AND BRIEF SFC WND G40KT POSSIBLE WITH HEAVIER RAIN 18Z-20Z. KTEB FCSTER COMMENTS: PEAK FL020 WINDS 17075KT AND BRIEF SFC WND G40KT POSSIBLE WITH HEAVIER RAIN 18Z-20Z. KHPN FCSTER COMMENTS: PEAK FL020 WINDS 17075KT AND BRIEF SFC WND G40KT POSSIBLE WITH HEAVIER RAIN 18Z-20Z. KISP FCSTER COMMENTS: PEAK FL020 WINDS 17085KT AND BRIEF SFC WND G50KT POSSIBLE WITH HEAVIER RAIN 19Z-21Z. .OUTLOOK FOR 12Z WED THROUGH SAT... .WED-FRI...VFR. .FRI NIGHT...CHANCE OF MIXED PRECIP WITH MVFR OR LOWER CONDS. SW WINDS G20KT LATE. .SAT...CHANCE OF RAIN SHOWERS MVFR OR LOWER CONDS IN THE MORNING. W WINDS G20-25KT. && .MARINE... THE FORECAST REMAINS ON TRACK THIS AFTERNOON. GALE WARNINGS REMAIN IN EFFECT FOR THE OCEAN AND GREAT SOUTH BAY...AS STRONG SOUTHERLY WINDS WILL GUST TO 35-40 KT...POSSIBLY AS HIGH AS 45 KT ON THE OPEN ATLANTIC OCEAN WATERS. ON ALL OTHER WATERS...A FEW GUSTS TO 35 KT ARE POSSIBLE...BUT THINK MOST OF THE GUSTS WILL TOP OFF AROUND 30 KT. WITH THE STORM DEPARTING THIS EVENING...WINDS WILL DIMINISH FAIRLY QUICKLY...AND SUB-SCA CONDITIONS LIKELY ON MOST WATERS BEFORE MIDNIGHT TONIGHT. OCEAN SEAS WILL REMAIN HIGH...AND SCA WILL LIKELY BE NEEDED FOR THOSE WATERS WHEN THE GALES END. SEAS SHOULD REMAIN ABOVE SMALL CRAFT LEVELS ON THE COASTAL OCEAN WATERS ON WEDNESDAY...WITH SUB-SMALL CRAFT CONDITIONS ON THE NON- OCEAN WATERS. WINDS INCREASE WEDNESDAY NIGHT AND THURSDAY IN RESPONSE TO COLD AIR ADVECTION...WITH SMALL CRAFT CONDITIONS LIKELY ON THE COASTAL OCEAN WATERS AND POSSIBLE ON THE NON-OCEAN WATERS. WINDS ON THE NON-OCEAN WATERS SHOULD BE 15 KT OR LESS THURSDAY NIGHT-SATURDAY. ON THE COASTAL OCEAN WATERS SMALL CRAFT CONDITIONS ARE LIKELY IN THIS TIME FRAME DUE TO BOTH WIND GUSTS TO AROUND 25 KT AND SEAS 5 FT OR GREATER. && .HYDROLOGY... A TOTAL OF AROUND 1 INCH OF LIQUID PRECIPITATION...WITH LOCALLY HIGHER AMOUNTS POSSIBLE...IS EXPECTED THROUGH THIS EVENING. HEAVY RAIN MAY LEAD TO URBAN AND POOR DRAINAGE ISSUES. SOME SMALLER AND FASTER REACTING STREAMS ACROSS NORTHEASTERN NEW JERSEY MAY APPROACH BANKFULL THIS AFTERNOON. NO SIGNIFICANT PRECIPITATION IS EXPECTED FROM WEDNESDAY INTO SUNDAY. && .TIDES/COASTAL FLOODING... A COASTAL FLOOD ADVISORY REMAINS UP FOR THE SOUTH SHORE BAYS OF NASSAU AND SUFFOLK COUNTIES FOR THE HIGH TIDE CYCLE THIS AFTERNOON AND EVENING. TIDES ARE ASTRONOMICALLY LOW...BEING BETWEEN A NEW AND FULL MOON. THE HIGH TIDE CYCLE THIS AFTERNOON AND EVENING WILL COINCIDE WITH A PROLONGED PERIOD OF STRONG SE WINDS AND THE HIGHEST SURGE. SURGE VALUES OF 2 1/2 TO 3 FT WILL BE SUFFICIENT FOR MINOR COASTAL FLOODING ACROSS THE SOUTH SHORE BACK BAYS OF LONG ISLAND AS WELL AS LOCATIONS ADJACENT TO PECONIC AND GARDINERS BAYS. WATER LEVELS LOOK TO FALL JUST SHY OF MINOR FLOOD BENCHMARKS AT THE NYC SOUTH SHORE BAYS. WILL GO AHEAD AND ISSUE A COASTAL FLOOD STATEMENT FOR THE CT COAST FOR THE LATE AFTERNOON/EARLY EVENING HIGH TIDE CYCLE...AS THE STRONG SOUTHERLY WINDS MAY RESULT IN LOCALIZED MINOR COASTAL FLOODING. && .EQUIPMENT... KOKX RADAR IS OUT OF SERVICE UNTIL FURTHER NOTICE. A PART IS ON ORDER...BUT A RETURN TO SERVICE TIME IS UNKNOWN. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...COASTAL FLOOD ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ080- 179. COASTAL FLOOD ADVISORY UNTIL 8 PM EST THIS EVENING FOR NYZ079- 081. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ330-335- 338-340. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ345-350-353- 355. && $$ SYNOPSIS...MALOIT/MPS NEAR TERM...DS SHORT TERM...MPS LONG TERM...MALOIT AVIATION...GOODMAN MARINE...MALOIT/MPS/DS HYDROLOGY...MALOIT/MPS TIDES/COASTAL FLOODING... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1031 AM EST TUE FEB 16 2016 .SYNOPSIS... A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING, FOLLOWED BY A STRONG LOW PRESSURE SYSTEM AND COLD FRONT THIS AFTERNOON. A WEAKENING COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE AREA LATER THURSDAY INTO EARLY FRIDAY, BEFORE MOVING OFFSHORE LATER FRIDAY. A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT LAKES AND INTO SOUTHERN CANADA FRIDAY, PULLING A WARM FRONT ACROSS THE AREA FRIDAY NIGHT, THEN A COLD FRONT SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE WARM FRONT HAS MOVED THROUGH THE REGION AS OF 10 AM...WITH TEMPERATURES RISING INTO THE 50S AT MOST LOCATIONS. THE HEAVIER RAIN OVER EASTERN PA AND DELMARVA WILL OVERSPREAD THE REGION THIS MORNING AND CONTINUE INTO THIS AFTERNOON. WHILE THERE IS A STOUT INVERSION ALOFT WHICH WILL PROHIBIT STRONGER WINDS FROM MIXING DOWN, GUSTS UP TO 40 MPH POSSIBLE IN HEAVIER RAIN BANDS. WE HAVE MADE SOME ADJUSTMENTS TO POPS, BRINGING THEM IN LINE WITH CURRENT RADAR AND SHORT RANGE MODEL TRENDS. OTHERWISE, ADJUSTMENTS WERE MADE TO TEMPERATURES, TIMING THE WARM FRONT THROUGH THE REGION, AS WELL AS MINOR ADJUSTMENTS TO THE WINDS. PREVIOUS DISCUSSION... SOME SPECTACULAR TEMPERATURE CHANGES DURING THIS TIME PERIOD. FREEZING RAIN ADVISORY ENDS IN NEXT TIER OF ZONES AT 500 AM AND THE WINTER WEATHER ADVISORY ENDS IN THE FAR NORTH AT 700 AM. LAST SEVERAL RUNS OF HRRR ARE ADAMANT THAT AIR TEMPERATURES WILL BE ABOVE FREEZING ACROSS THE REGION BY 600 AM, AND ON THEIR WAY TO HIGH TEMPERATURES FOR MUCH OF THE REGION WELL INTO THE 50S LATER TODAY. THAT AGREES WELL WITH OUR PREVIOUS FORECAST AND CURRENT FORECAST FOLLOWS THAT SCENARIO. PRECIPITATION IS EBBING FOR THE TIME BEING WITH JUST SOME VERY LIGHT PRECIPITATION (IF ANYTHING) DURING MUCH OF THE EARLY TO MID MORNING HOURS. THE COLD FRONT THIS AFTERNOON WILL BRING A ROUND OF MODERATE TO HEAVY RAINFALL ACROSS THE REGION. STRONG FORCING WILL BRING SOME VERY STRONG WINDS INTO THE REGION JUST OFF THE SURFACE. THE STRONGER STORMS MAY BE ABLE TO TAP INTO THOSE WINDS, SO BE PREPARED FOR SOME STRONG GUSTY WINDS WITH THE HEAVIER RAIN SHOWERS. A RUMBLE OF THUNDER IS ALSO STILL POSSIBLE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... THE HEAVY RAINFALL IS EXPECTED TO BE EXITING THE AREA VERY EARLY IN THIS TIME PERIOD. DIMINISHING CLOUD COVER AND MODERATE WESTERLY WINDS ARE EXPECTED DURING THIS TIME PERIOD. SUPERBLEND WAS USED FOR THE OVERNIGHT LOW TEMPERATURE FORECAST AND RESULTED IN ONLY MINOR CHANGES FROM PREVIOUS FORECAST. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... QUIETER/DRIER WEATHER IS IN STORE FOR MOST OF THE AREA, AT LEAST FOR THE BEGINNING OF THE LONG TERM FORECAST. MORE PRECIPITATION COULD RETURN FOR SOME OF THE WEEKEND AND EARLY NEXT WEEK. ON WEDNESDAY, THE LOW PRESSURE SYSTEM THAT BROUGHT ALL THE RAIN TUESDAY WILL BE WAY TO OUR NORTH, WHILE HIGH PRESSURE APPROACHES FROM THE WEST. THIS WILL KEEP A GENERAL WEST-NORTHWEST FLOW ACROSS THE AREA. A WEAKENING COLD FRONT APPROACHES THE AREA DURING THE DAY, WHILE A SHORT WAVE/VORTICITY IMPULSE SLIDES ACROSS THE AREA. IT IS POSSIBLE SOME LIGHT SHOWERS MAY AFFECT THE FAR NORTHWESTERN ZONES OF OUR AREA, BUT MOST EVERYONE SHOULD REMAIN DRY. IF THE FRONT HOLDS TOGETHER, IT WOULDN`T CROSS UNTIL WEDNESDAY NIGHT, BUT ANY PRECIPITATION WILL DISSIPATE AS IT MOVES ACROSS THE AREA. HIGH PRESSURE THEN BUILDS ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT, CENTERING ITSELF ACROSS THE AREA EARLY FRIDAY, THEN BEGINS TO BUILD OFFSHORE DURING THE DAY FRIDAY. DRY WEATHER IS CURRENTLY EXPECTED THURSDAY INTO FRIDAY AS THE HIGH BUILDS ACROSS THE AREA. AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES REGION FRIDAY AND INTO SOUTHERN CANADA FRIDAY NIGHT, PULLING A WARM FRONT ACROSS THE AREA, FOLLOWED BY A COLD FRONT EARLY SATURDAY. THERE COULD BE ENOUGH LOW-MID LEVEL MOISTURE COMBINED WITH A PASSING SHORT WAVE/VORTICITY IMPULSE TO CREATE SOME PRECIPITATION ACROSS THE AREA. IT IS POSSIBLE THAT TEMPERATURES COULD BE COLD ENOUGH FOR A WINTRY MIX TO OCCUR, ESPECIALLY ACROSS FAR NORTHERN AREAS WHERE SOME FREEZING RAIN MAY OCCUR. SOME LIGHT PRECIPITATION MAY FOLLOW DURING THE DAY SATURDAY AS THE FRONT PASSES ACROSS THE AREA, BUT ANY PRECIPITATION MAY ACTUALLY CHANGE TO RAIN DURING THE DAY. SATURDAY NIGHT INTO SUNDAY IS EXPECTED TO BE DRY IN THE WAKE OF THE FRONTAL PASSAGE. BUT THIS MAY NOT LAST LONG. THERE IS INDICATION THAT ANOTHER LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY COULD AFFECT THE AREA EARLY NEXT WEEK. THERE ARE DIFFERENCES BETWEEN THE GFS AND ECMWF, WITH THE GFS DEVELOPING A LOW TO OUR SOUTHWEST AND MOVING IT ACROSS THE AREA. THE LATEST ECMWF THE LOW TO OUR WEST AND PASSES IT NORTH OF THE AREA. DEPENDING ON THE TRACK OF THIS DEVELOPING LOW, IT IS POSSIBLE ANOTHER ROUND OF WINTRY PRECIPITATION COULD AFFECT THE AREA EARLY NEXT WEEK. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...CEILINGS LOWERING TO IFR AS RAIN OVERSPREADS THE REGION. WE ALSO EXPECT SOME FOG...PARTICULARLY AT ABE, RDG, AND ACY. SOUTHEAST WINDS 15 TO 25 KNOTS WITH GUSTS TO 35 KNOTS POSSIBLE BEFORE VEERING TO THE SOUTHWEST THIS AFTERNOON. LOW-LEVEL WIND SHEAR IS EXPECTED FOR THIS MORNING AND EARLY THIS AFTERNOON AS A SOUTHERLY LOW-LEVEL JET NEAR 65 KNOTS MOVES ACROSS THE AREA. TONIGHT...GENERALLY MVFR. OUTLOOK... WEDNESDAY-FRIDAY...MAINLY VFR. GUSTY AFTERNOON WINDS AROUND 20 KNOTS. FRIDAY NIGHT...LIGHT RAIN OR LIGHT WINTRY MIX ACROSS THE NORTH MAY AFFECT THE AREA AND RESULT IN SUB-VFR CONDITIONS. SATURDAY-GENERALLY VFR. SOME LIGHT RAIN POSSIBLE DURING THE DAY.GUSTY AFTERNOON WINDS 20-25 KNOTS POSSIBLE. && .MARINE... GALE WARNINGS CONTINUE AS VERY STRONG SOUTHERLY WINDS DEVELOP IN RESPONSE TO RAPIDLY INTENSIFYING SURFACE LOW TRACKING INLAND UP THE EAST COAST. THE STRONGEST WINDS ARE EXPECTED AROUND MIDDAY TODAY AS A LINE OF HEAVIER RAIN AND POSSIBLY EMBEDDED THUNDER CROSSES THE COASTAL WATERS...W/ LOCALIZED STORM FORCE GUSTS POSSIBLE ASSOCIATED WITH THIS LINE. OVERALL...THIS IS EXPECTED TO BE A HIGH END GALE EVENT. SEAS ON THE ATLC WATERS SHOULD RISE TO BETWEEN 10 AND 13 FT. AS THE COLD FRONT PASSES OVER THE WATERS LATE TODAY INTO TONIGHT, THERE SHOULD AGAIN BE GALE FORCE GUSTS, AS WINDS VEER FROM SOUTH TO SOUTHWEST. WINDS WILL BECOME WEST OVERNIGHT AND DIMIMISH TO SUB-GALE LEVELS AFTER MIDNIGHT. OUTLOOK... WEDNESDAY-THURSDAY...SMALL CRAFT ADVISORY LEVEL SEAS MAY REMAIN ACROSS THE AREA. WINDS COULD GUST 20-25 KNOTS AS WELL. THURSDAY NIGHT-FRIDAY...SUB SMALL CRAFT ADVISORY CONDITIONS WITH HIGH PRESSURE ACROSS THE WATERS. FRIDAY NIGHT-SATURDAY...WINDS LIKELY TO INCREASE TO SMALL CRAFT ADVISORY LEVELS, WITH POSSIBLE NEAR GALE FORCE GUSTS FRIDAY NIGHT SATURDAY MORNING. && .HYDROLOGY... THERE STILL REMAINS THE THREAT FOR SOME URBANIZED AND POOR DRAINAGE FLOODING AT TIMES LATER THIS MORNING AND INTO THIS AFTERNOON WITH THE HEAVY RAIN. WHERE STORM DRAINS ARE BLOCKED BY SNOW, ICE AND DEBRIS, POOR DRAINAGE STREET FLOODING IS POSSIBLE. ONE TO ONE AND A HALF INCHES OF RAINFALL, POSSIBLY UP TO TWO INCHES IN SOME AREAS, FALLING ON TOP OF THE SNOW COULD MAKE FOR EFFICIENT RUNOFF AND CAUSE SOME LOCALIZED FLOODING, ESPECIALLY ACROSS THE NORTHERN TWO THIRDS OF THE AREA. AREAS ACROSS THE SOUTHERN THIRD MAY NOT GET AS MUCH RAIN, ONLY A HALF INCH TO ONE INCH. THERE WILL ALSO BE SHARP RISES ON OUR LOCAL CREEKS, STEAMS, AND RIVERS. HOWEVER, NONE OF THE FORECAST RIVER GAUGES ARE EXPECTED TO GET TO FLOOD STAGE AT THIS TIME. && .TIDES/COASTAL FLOODING... THE DEVELOPMENT OF A MODERATE SOUTHERLY FLOW TODAY SHOULD PUSH WATER UP CHESAPEAKE BAY AND UP DELAWARE BAY AND INTO THE TIDAL DELAWARE RIVER. HOWEVER, MOST OF THE AVAILABLE GUIDANCE STILL SUGGESTS THAT NO FLOODING WILL OCCUR. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...GALE WARNING UNTIL 11 PM EST THIS EVENING FOR ANZ450>453. GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ430-431-454- 455. && $$ SYNOPSIS...ROBERTSON NEAR TERM...FRANCK SHORT TERM...SZATKOWSKI LONG TERM...ROBERTSON AVIATION...SZATKOWSKI/ROBERTSON/FRANCK MARINE...SZATKOWSKI/ROBERTSON/FRANCK HYDROLOGY... TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
657 AM EST TUE FEB 16 2016 .SYNOPSIS... A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING, FOLLOWED BY A STRONG LOW PRESSURE SYSTEM AND COLD FRONT THIS AFTERNOON. A WEAKENING COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE AREA LATER THURSDAY INTO EARLY FRIDAY, BEFORE MOVING OFFSHORE LATER FRIDAY. A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT LAKES AND INTO SOUTHERN CANADA FRIDAY, PULLING A WARM FRONT ACROSS THE AREA FRIDAY NIGHT, THEN A COLD FRONT SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... TEMPERATURES HAVE WARMED ABOVE FREEZING SO ALL THE WINTER WEATHER HEADLINE PRODUCTS HAVE BEEN ALLOWED TO EXPIRE. AFTER A BREAK IN THE PRECIPITATION DURING THE EARLY MORNING HOURS, THE NEXT ROUND OF MODERATE TO HEAVY RAIN IS OFF TO OUR WEST AND WILL BE IMPACTING OUR REGION LATER THIS MORNING. PREVIOUS DISCUSSION... SOME SPECTACULAR TEMPERATURE CHANGES DURING THIS TIME PERIOD. FREEZING RAIN ADVISORY ENDS IN NEXT TIER OF ZONES AT 500 AM AND THE WINTER WEATHER ADVISORY ENDS IN THE FAR NORTH AT 700 AM. LAST SEVERAL RUNS OF HRRR ARE ADAMANT THAT AIR TEMPERATURES WILL BE ABOVE FREEZING ACROSS THE REGION BY 600 AM, AND ON THEIR WAY TO HIGH TEMPERATURES FOR MUCH OF THE REGION WELL INTO THE 50S LATER TODAY. THAT AGREES WELL WITH OUR PREVIOUS FORECAST AND CURRENT FORECAST FOLLOWS THAT SCENARIO. PRECIPITATION IS EBBING FOR THE TIME BEING WITH JUST SOME VERY LIGHT PRECIPITATION (IF ANYTHING) DURING MUCH OF THE EARLY TO MID MORNING HOURS. THE COLD FRONT THIS AFTERNOON WILL BRING A ROUND OF MODERATE TO HEAVY RAINFALL ACROSS THE REGION. STRONG FORCING WILL BRING SOME VERY STRONG WINDS INTO THE REGION JUST OFF THE SURFACE. THE STRONGER STORMS MAY BE ABLE TO TAP INTO THOSE WINDS, SO BE PREPARED FOR SOME STRONG GUSTY WINDS WITH THE HEAVIER RAIN SHOWERS. A RUMBLE OF THUNDER IS ALSO STILL POSSIBLE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... THE HEAVY RAINFALL IS EXPECTED TO BE EXITING THE AREA VERY EARLY IN THIS TIME PERIOD. DIMINISHING CLOUD COVER AND MODERATE WESTERLY WINDS ARE EXPECTED DURING THIS TIME PERIOD. SUPERBLEND WAS USED FOR THE OVERNIGHT LOW TEMPERATURE FORECAST AND RESULTED IN ONLY MINOR CHANGES FROM PREVIOUS FORECAST. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... QUIETER/DRIER WEATHER IS IN STORE FOR MOST OF THE AREA, AT LEAST FOR THE BEGINNING OF THE LONG TERM FORECAST. MORE PRECIPITATION COULD RETURN FOR SOME OF THE WEEKEND AND EARLY NEXT WEEK. ON WEDNESDAY, THE LOW PRESSURE SYSTEM THAT BROUGHT ALL THE RAIN TUESDAY WILL BE WAY TO OUR NORTH, WHILE HIGH PRESSURE APPROACHES FROM THE WEST. THIS WILL KEEP A GENERAL WEST-NORTHWEST FLOW ACROSS THE AREA. A WEAKENING COLD FRONT APPROACHES THE AREA DURING THE DAY, WHILE A SHORT WAVE/VORTICITY IMPULSE SLIDES ACROSS THE AREA. IT IS POSSIBLE SOME LIGHT SHOWERS MAY AFFECT THE FAR NORTHWESTERN ZONES OF OUR AREA, BUT MOST EVERYONE SHOULD REMAIN DRY. IF THE FRONT HOLDS TOGETHER, IT WOULDN`T CROSS UNTIL WEDNESDAY NIGHT, BUT ANY PRECIPITATION WILL DISSIPATE AS IT MOVES ACROSS THE AREA. HIGH PRESSURE THEN BUILDS ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT, CENTERING ITSELF ACROSS THE AREA EARLY FRIDAY, THEN BEGINS TO BUILD OFFSHORE DURING THE DAY FRIDAY. DRY WEATHER IS CURRENTLY EXPECTED THURSDAY INTO FRIDAY AS THE HIGH BUILDS ACROSS THE AREA. AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES REGION FRIDAY AND INTO SOUTHERN CANADA FRIDAY NIGHT, PULLING A WARM FRONT ACROSS THE AREA, FOLLOWED BY A COLD FRONT EARLY SATURDAY. THERE COULD BE ENOUGH LOW-MID LEVEL MOISTURE COMBINED WITH A PASSING SHORT WAVE/VORTICITY IMPULSE TO CREATE SOME PRECIPITATION ACROSS THE AREA. IT IS POSSIBLE THAT TEMPERATURES COULD BE COLD ENOUGH FOR A WINTRY MIX TO OCCUR, ESPECIALLY ACROSS FAR NORTHERN AREAS WHERE SOME FREEZING RAIN MAY OCCUR. SOME LIGHT PRECIPITATION MAY FOLLOW DURING THE DAY SATURDAY AS THE FRONT PASSES ACROSS THE AREA, BUT ANY PRECIPITATION MAY ACTUALLY CHANGE TO RAIN DURING THE DAY. SATURDAY NIGHT INTO SUNDAY IS EXPECTED TO BE DRY IN THE WAKE OF THE FRONTAL PASSAGE. BUT THIS MAY NOT LAST LONG. THERE IS INDICATION THAT ANOTHER LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY COULD AFFECT THE AREA EARLY NEXT WEEK. THERE ARE DIFFERENCES BETWEEN THE GFS AND ECMWF, WITH THE GFS DEVELOPING A LOW TO OUR SOUTHWEST AND MOVING IT ACROSS THE AREA. THE LATEST ECMWF THE LOW TO OUR WEST AND PASSES IT NORTH OF THE AREA. DEPENDING ON THE TRACK OF THIS DEVELOPING LOW, IT IS POSSIBLE ANOTHER ROUND OF WINTRY PRECIPITATION COULD AFFECT THE AREA EARLY NEXT WEEK. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...LIFR CONDITIONS POSSIBLE AT ABE AND RDG IN LOW CLOUDS AND FOG UNTIL AROUND 12Z. OTHERWISE GENERALLY MVFR/IFR CONDITIONS TODAY. PERIODS OF RAIN WHICH WILL BE MODERATE TO HEAVY STARTING LATE THIS MORNING AND CONTINUING INTO THE AFTERNOON. SOUTHEAST WINDS MOSTLY 10-15 KNOTS AND POSSIBLY LOCALLY GUSTY, TURNING SOUTHWEST IN THE AFTERNOON. LOW-LEVEL WIND SHEAR IS EXPECTED FOR AWHILE AS A SOUTHERLY LOW-LEVEL JET NEAR 65 KNOTS MOVES ACROSS THE AREA. TONIGHT...GENERALLY MVFR. OUTLOOK... WEDNESDAY-FRIDAY...MAINLY VFR. GUSTY AFTERNOON WINDS AROUND 20 KNOTS. FRIDAY NIGHT...LIGHT RAIN OR LIGHT WINTRY MIX ACROSS THE NORTH MAY AFFECT THE AREA AND RESULT IN SUB-VFR CONDITIONS. SATURDAY-GENERALLY VFR. SOME LIGHT RAIN POSSIBLE DURING THE DAY.GUSTY AFTERNOON WINDS 20-25 KNOTS POSSIBLE. && .MARINE... NO SIGNIFICANT CHANGES TO THE SHORT TERM SECTION OF THE MARINE FORECAST. GALE WARNINGS CONTINUE AS VERY STRONG SOUTHERLY WINDS DEVELOP IN RESPONSE TO RAPIDLY INTENSIFYING SURFACE LOW TRACKING INLAND UP THE EAST COAST. STRONGEST WINDS ARE EXPECTED AROUND MIDDAY TODAY. EXPECTED TO BE A HIGH END GALE EVENT. A FEW GUSTS TO STORM FORCE ARE POSSIBLE. SUBSEQUENTLY, AS THE COLD FRONT PASSES OVER THE WATERS LATE TODAY INTO TONIGHT, THERE SHOULD AGAIN BE GALE FORCE GUSTS. SEAS ON THE ATLC WATERS SHOULD RISE TO BETWEEN 10 AND 13 FT. OUTLOOK... WEDNESDAY-THURSDAY...SMALL CRAFT ADVISORY LEVEL SEAS MAY REMAIN ACROSS THE AREA. WINDS COULD GUST 20-25 KNOTS AS WELL. THURSDAY NIGHT-FRIDAY...SUB SMALL CRAFT ADVISORY CONDITIONS WITH HIGH PRESSURE ACROSS THE WATERS. FRIDAY NIGHT-SATURDAY...WINDS LIKELY TO INCREASE TO SMALL CRAFT ADVISORY LEVELS, WITH POSSIBLE NEAR GALE FORCE GUSTS FRIDAY NIGHT SATURDAY MORNING. && .HYDROLOGY... THERE STILL REMAINS THE THREAT FOR SOME URBANIZED AND POOR DRAINAGE FLOODING AT TIMES LATER THIS MORNING AND INTO THIS AFTERNOON WITH THE HEAVY RAIN. WHERE STORM DRAINS ARE BLOCKED BY SNOW, ICE AND DEBRIS, POOR DRAINAGE STREET FLOODING IS POSSIBLE. ONE TO ONE AND A HALF INCHES OF RAINFALL, POSSIBLY UP TO TWO INCHES IN SOME AREAS, FALLING ON TOP OF THE SNOW COULD MAKE FOR EFFICIENT RUNOFF AND CAUSE SOME LOCALIZED FLOODING, ESPECIALLY ACROSS THE NORTHERN TWO THIRDS OF THE AREA. AREAS ACROSS THE SOUTHERN THIRD MAY NOT GET AS MUCH RAIN, ONLY A HALF INCH TO ONE INCH. THERE WILL ALSO BE SHARP RISES ON OUR LOCAL CREEKS, STEAMS, AND RIVERS. HOWEVER, NONE OF THE FORECAST RIVER GAUGES ARE EXPECTED TO GET TO FLOOD STAGE AT THIS TIME. && .TIDES/COASTAL FLOODING... THE DEVELOPMENT OF A MODERATE SOUTHERLY FLOW TODAY SHOULD PUSH WATER UP CHESAPEAKE BAY AND UP DELAWARE BAY AND INTO THE TIDAL DELAWARE RIVER. HOWEVER, MOST OF THE AVAILABLE GUIDANCE STILL SUGGESTS THAT NO FLOODING WILL OCCUR. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...GALE WARNING UNTIL 11 PM EST THIS EVENING FOR ANZ450>453. GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ430-431-454- 455. && $$ SYNOPSIS...ROBERTSON NEAR TERM...SZATKOWSKI SHORT TERM...SZATKOWSKI LONG TERM...ROBERTSON AVIATION...SZATKOWSKI/ROBERTSON MARINE...SZATKOWSKI HYDROLOGY... TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
403 AM EST TUE FEB 16 2016 .SYNOPSIS... A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING, FOLLOWED BY A STRONG LOW PRESSURE SYSTEM AND COLD FRONT THIS AFTERNOON. A WEAKENING COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE AREA LATER THURSDAY INTO EARLY FRIDAY, BEFORE MOVING OFFSHORE LATER FRIDAY. A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT LAKES AND INTO SOUTHERN CANADA FRIDAY, PULLING A WARM FRONT ACROSS THE AREA FRIDAY NIGHT, THEN A COLD FRONT SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SOME SPECTACULAR TEMPERATURE CHANGES DURING THIS TIME PERIOD. FREEZING RAIN ADVISORY ENDS IN NEXT TIER OF ZONES AT 500 AM AND THE WINTER WEATHER ADVISORY ENDS IN THE FAR NORTH AT 700 AM. LAST SEVERAL RUNS OF HRRR ARE ADAMANT THAT AIR TEMPERATURES WILL BE ABOVE FREEZING ACROSS THE REGION BY 600 AM, AND ON THEIR WAY TO HIGH TEMPERATURES FOR MUCH OF THE REGION WELL INTO THE 50S LATER TODAY. THAT AGREES WELL WITH OUR PREVIOUS FORECAST AND CURRENT FORECAST FOLLOWS THAT SCENARIO. PRECIPITATION IS EBBING FOR THE TIME BEING WITH JUST SOME VERY LIGHT PRECIPITATION (IF ANYTHING) DURING MUCH OF THE EARLY TO MID MORNING HOURS. THE COLD FRONT THIS AFTERNOON WILL BRING A ROUND OF MODERATE TO HEAVY RAINFALL ACROSS THE REGION. STRONG FORCING WILL BRING SOME VERY STRONG WINDS INTO THE REGION JUST OFF THE SURFACE. THE STRONGER STORMS MAY BE ABLE TO TAP INTO THOSE WINDS, SO BE PREPARED FOR SOME STRONG GUSTY WINDS WITH THE HEAVIER RAIN SHOWERS. A RUMBLE OF THUNDER IS ALSO STILL POSSIBLE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... THE HEAVY RAINFALL IS EXPECTED TO BE EXITING THE AREA VERY EARLY IN THIS TIME PERIOD. DIMINISHING CLOUD COVER AND MODERATE WESTERLY WINDS ARE EXPECTED DURING THIS TIME PERIOD. SUPERBLEND WAS USED FOR THE OVERNIGHT LOW TEMPERATURE FORECAST AND RESULTED IN ONLY MINOR CHANGES FROM PREVIOUS FORECAST. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... QUIETER/DRIER WEATHER IS IN STORE FOR MOST OF THE AREA, AT LEAST FOR THE BEGINNING OF THE LONG TERM FORECAST. MORE PRECIPITATION COULD RETURN FOR SOME OF THE WEEKEND AND EARLY NEXT WEEK. ON WEDNESDAY, THE LOW PRESSURE SYSTEM THAT BROUGHT ALL THE RAIN TUESDAY WILL BE WAY TO OUR NORTH, WHILE HIGH PRESSURE APPROACHES FROM THE WEST. THIS WILL KEEP A GENERAL WEST-NORTHWEST FLOW ACROSS THE AREA. A WEAKENING COLD FRONT APPROACHES THE AREA DURING THE DAY, WHILE A SHORT WAVE/VORTICITY IMPULSE SLIDES ACROSS THE AREA. IT IS POSSIBLE SOME LIGHT SHOWERS MAY AFFECT THE FAR NORTHWESTERN ZONES OF OUR AREA, BUT MOST EVERYONE SHOULD REMAIN DRY. IF THE FRONT HOLDS TOGETHER, IT WOULDN`T CROSS UNTIL WEDNESDAY NIGHT, BUT ANY PRECIPITATION WILL DISSIPATE AS IT MOVES ACROSS THE AREA. HIGH PRESSURE THEN BUILDS ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT, CENTERING ITSELF ACROSS THE AREA EARLY FRIDAY, THEN BEGINS TO BUILD OFFSHORE DURING THE DAY FRIDAY. DRY WEATHER IS CURRENTLY EXPECTED THURSDAY INTO FRIDAY AS THE HIGH BUILDS ACROSS THE AREA. AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES REGION FRIDAY AND INTO SOUTHERN CANADA FRIDAY NIGHT, PULLING A WARM FRONT ACROSS THE AREA, FOLLOWED BY A COLD FRONT EARLY SATURDAY. THERE COULD BE ENOUGH LOW-MID LEVEL MOISTURE COMBINED WITH A PASSING SHORT WAVE/VORTICITY IMPULSE TO CREATE SOME PRECIPITATION ACROSS THE AREA. IT IS POSSIBLE THAT TEMPERATURES COULD BE COLD ENOUGH FOR A WINTRY MIX TO OCCUR, ESPECIALLY ACROSS FAR NORTHERN AREAS WHERE SOME FREEZING RAIN MAY OCCUR. SOME LIGHT PRECIPITATION MAY FOLLOW DURING THE DAY SATURDAY AS THE FRONT PASSES ACROSS THE AREA, BUT ANY PRECIPITATION MAY ACTUALLY CHANGE TO RAIN DURING THE DAY. SATURDAY NIGHT INTO SUNDAY IS EXPECTED TO BE DRY IN THE WAKE OF THE FRONTAL PASSAGE. BUT THIS MAY NOT LAST LONG. THERE IS INDICATION THAT ANOTHER LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY COULD AFFECT THE AREA EARLY NEXT WEEK. THERE ARE DIFFERENCES BETWEEN THE GFS AND ECMWF, WITH THE GFS DEVELOPING A LOW TO OUR SOUTHWEST AND MOVING IT ACROSS THE AREA. THE LATEST ECMWF THE LOW TO OUR WEST AND PASSES IT NORTH OF THE AREA. DEPENDING ON THE TRACK OF THIS DEVELOPING LOW, IT IS POSSIBLE ANOTHER ROUND OF WINTRY PRECIPITATION COULD AFFECT THE AREA EARLY NEXT WEEK. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...LIFR CONDITIONS POSSIBLE AT ABE AND RDG IN LOW CLOUDS AND FOG UNTIL AROUND 12Z. OTHERWISE GENERALLY MVFR/IFR CONDITIONS TODAY. PERIODS OF RAIN WHICH WILL BE MODERATE TO HEAVY STARTING LATE THIS MORNING AND CONTINUING INTO THE AFTERNOON. SOUTHEAST WINDS MOSTLY 10-15 KNOTS AND POSSIBLY LOCALLY GUSTY, TURNING SOUTHWEST IN THE AFTERNOON. LOW-LEVEL WIND SHEAR IS EXPECTED FOR AWHILE AS A SOUTHERLY LOW-LEVEL JET NEAR 65 KNOTS MOVES ACROSS THE AREA. TONIGHT...GENERALLY MVFR. OUTLOOK... WEDNESDAY-FRIDAY...MAINLY VFR. GUSTY AFTERNOON WINDS AROUND 20 KNOTS. FRIDAY NIGHT...LIGHT RAIN OR LIGHT WINTRY MIX ACROSS THE NORTH MAY AFFECT THE AREA AND RESULT IN SUB-VFR CONDITIONS. SATURDAY-GENERALLY VFR. SOME LIGHT RAIN POSSIBLE DURING THE DAY.GUSTY AFTERNOON WINDS 20-25 KNOTS POSSIBLE. && .MARINE... NO SIGNIFICANT CHANGES TO THE SHORT TERM SECTION OF THE MARINE FORECAST. GALE WARNINGS CONTINUE AS VERY STRONG SOUTHERLY WINDS DEVELOP IN RESPONSE TO RAPIDLY INTENSIFYING SURFACE LOW TRACKING INLAND UP THE EAST COAST. STRONGEST WINDS ARE EXPECTED AROUND MIDDAY TODAY. EXPECTED TO BE A HIGH END GALE EVENT. A FEW GUSTS TO STORM FORCE ARE POSSIBLE. SUBSEQUENTLY, AS THE COLD FRONT PASSES OVER THE WATERS LATE TODAY INTO TONIGHT, THERE SHOULD AGAIN BE GALE FORCE GUSTS. SEAS ON THE ATLC WATERS SHOULD RISE TO BETWEEN 10 AND 13 FT. OUTLOOK... WEDNESDAY-THURSDAY...SMALL CRAFT ADVISORY LEVEL SEAS MAY REMAIN ACROSS THE AREA. WINDS COULD GUST 20-25 KNOTS AS WELL. THURSDAY NIGHT-FRIDAY...SUB SMALL CRAFT ADVISORY CONDITIONS WITH HIGH PRESSURE ACROSS THE WATERS. FRIDAY NIGHT-SATURDAY...WINDS LIKELY TO INCREASE TO SMALL CRAFT ADVISORY LEVELS, WITH POSSIBLE NEAR GALE FORCE GUSTS FRIDAY NIGHT SATURDAY MORNING. && .HYDROLOGY... THERE STILL REMAINS THE THREAT FOR SOME URBANIZED AND POOR DRAINAGE FLOODING AT TIMES THIS AFTERNOON WITH THE HEAVY RAIN. WHERE STORM DRAINS ARE BLOCKED BY SNOW, ICE AND DEBRIS, POOR DRAINAGE STREET FLOODING IS POSSIBLE. ONE TO ONE AND A HALF INCHES OF RAINFALL, POSSIBLY UP TO TWO INCHES IN SOME AREAS, FALLING ON TOP OF THE SNOW COULD MAKE FOR EFFICIENT RUNOFF AND CAUSE SOME LOCALIZED FLOODING, ESPECIALLY ACROSS THE NORTHERN TWO THIRDS OF THE AREA. AREAS ACROSS THE SOUTHERN THIRD MAY NOT GET AS MUCH RAIN, ONLY A HALF INCH TO ONE INCH. THERE WILL ALSO BE SHARP RISES ON OUR LOCAL CREEKS, STEAMS, AND RIVERS. HOWEVER, NONE OF THE FORECAST RIVER GAUGES ARE EXPECTED TO GET TO FLOOD STAGE AT THIS TIME. && .TIDES/COASTAL FLOODING... THE DEVELOPMENT OF A MODERATE SOUTHERLY FLOW TODAY SHOULD PUSH WATER UP CHESAPEAKE BAY AND UP DELAWARE BAY AND INTO THE TIDAL DELAWARE RIVER. HOWEVER, MOST OF THE AVAILABLE GUIDANCE STILL SUGGESTS THAT NO FLOODING WILL OCCUR. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR PAZ060>062-101-103-105. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ054- 055. NJ...FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR NJZ007>010. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NJZ001. DE...NONE. MD...NONE. MARINE...GALE WARNING FROM 7 AM THIS MORNING TO 11 PM EST THIS EVENING FOR ANZ450>453. GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ454-455. GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...ROBERTSON NEAR TERM...SZATKOWSKI SHORT TERM...SZATKOWSKI LONG TERM...ROBERTSON AVIATION...SZATKOWSKI/ROBERTSON MARINE...SZATKOWSKI HYDROLOGY... TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
333 AM EST TUE FEB 16 2016 .DISCUSSION... ...TORNADO WATCH IN EFFECT FOR OSCEOLA...OKEECHOBEE...BREVARD... INDIAN RIVER...ST LUCIE AND MARTIN COUNTIES UNTIL 8 AM... CURRENTLY-TODAY...CAPE WIND PROFILERS SHOW LOW LEVEL WINDS 30-40 KNOTS BUT THE FLOW HAS BEEN VEERING AROUND TO THE SOUTH AND LOOKING MORE UNIDIRECTIONAL WITH TIME. A BAND OF PRE FRONTAL CONVECTION HAS BEEN MOVING EAST OVER THE GULF OF MEXICO AROUND 30 KNOTS. AN AREA OF CONVECTION THAT HAD FORMED OVER THE LOOP CURRENT WAS SPREADING INLAND AHEAD OF THE CONVECTIVE BAND. THE LIGHTNING DETECTION NETWORK SHOWS A DECREASE IN ACTIVITY EXCEPT FOR THE SOUTHERN END WHERE INFLOW OF MORE MOIST/UNSTABLE AIR WAS BEING MAINTAINED. FOR THIS REASON A TORNADO WATCH HAS BEEN ISSUED FROM OSCEOLA/BREVARD SOUTHWARD TO OKEECHOBEE AND THE TREASURE COAST. THE LATEST HRRR SHOWS A BAND HOLDING TOGETHER AND CROSSING OUR AREA FROM ABOUT 3 TO 8 AM...EXCEPT POSSIBLY SLOWING AND LINGERING UNTIL LATE MORNING ALONG THE TREASURE COAST. ONCE THE PRE FRONTAL CONVECTION SHIFTS OFFSHORE...THE HRRR IR CLOUD PRODUCT SHOWS IT CLEARING OUT RATHER QUICKLY. THE COLD FRONT WILL BE SLOWING DOWN...SO THE AFTERNOON LOOKS WARM. SURFACE THETA E FIELD SHOWS PASSAGE OF THE FRONT LATE IN THE DAY. TEMPS EXPECTED TO REACH AROUND 80 DEGREES OVER MUCH OF THE AREA...EXCEPT MID-UPPER 70S IN THE NORTH. DRYING AND COOL AIR ADVECTION TONIGHT WILL DROP TEMPS DOWN INTO THE UPPER 40S TO MID 50S UNDER MOSTLY CLEAR SKIES. WED-SUN...MOSTLY DRY WITH NEAR NORMAL TEMPERATURES EXPECTED THROUGH MUCH OF THE PERIOD. A WEAK COLD FRONT WILL CROSS THE AREA WEDNESDAY BUT MODELS SHOW LIMITED MOISTURE WITH THIS BOUNDARY SO NOT EXPECTING ANY RAINFALL. HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL EVENTUALLY PUSH OFF THE MID ATLANTIC COAST AND SHIFT SOUTHEAST WITH RIDGE AXIS GRADUALLY BUILDING DOWN ACROSS THE REGION INTO THE WEEKEND. THIS WILL ALLOW LOW LEVEL NORTHERLY FLOW BEHIND THE FRONT TO VEER ONSHORE LATE WEEK INTO THE WEEKEND. SOME MOISTURE INCREASE IS INDICATED BY THE MODELS AND MAY SEE A FEW ONSHORE MOVING SHOWERS BY WEEKS END...BUT FOR NOW RAIN CHANCES TOO LOW TO MENTION. HIGHS WILL BE IN THE LOW TO MID 70S MOST DAYS WITH LOWS IN THE 40S AND 50S. MON...FRONT MOVING ACROSS SOUTHEAST AND GULF COAST PUSHES THE FLORIDA RIDGE SOUTH. SOUTHEAST WINDS SHIFT TO THE SOUTH THEN SOUTHWEST. MOISTURE LEVELS DO NOT INCREASE APPRECIABLY SO MODEL POP MAY BE A BIT HIGH. && .AVIATION... A PERIOD OF MVFR-IFR WILL OCCUR WITH A PRE FRONTAL BAND OF SHOWERS/STORMS. THE LATEST HRRR MODEL SHOWS THE BAND REACHING THE INTERSTATE 4 CORRIDOR AROUND 09Z. GUIDANCE INDICATES CONDITIONS WILL BECOME VFR QUICKLY BEHIND THE BAND...MOST LIKELY BEFORE MIDDAY AT ALL THE TAF SITES. .MARINE... TODAY-TONIGHT... ADVISORY CONDITIONS OVER ALL BUT THE IMMEDIATE VOLUSIA COASTAL EARLY THIS MORNING. OCCASIONAL GUSTS TO GALE FORCE WILL OCCUR OVER THE OUTER WATERS EARLY. SOUTH WINDS WILL VEER TO SOUTHWEST THEN BECOME WEST/NORTHWEST BEHIND THE FRONT LATE TODAY AND TONIGHT. WINDS WILL DIMINISH TO 15 KNOTS OR LESS BY AFTERNOON...BUT WILL HOLD ONTO ADVISORY THROUGH 4 PM DUE TO SEAS BEING SLOW TO SUBSIDE. WED-SAT...A WEAK FRONT WILL CROSS THE WATERS WEDNESDAY WITH ELEVATED WESTERLY FLOW UP TO AROUND 15 KNOTS BECOMING NORTHWEST TO NORTH INTO WEDNESDAY NIGHT. THIS WILL BUILD SEAS TO 6 TO 8 FEET OFFSHORE/GULF STREAM WEDNESDAY NIGHT THROUGH DAY BREAK FRIDAY. SEAS SUBSIDE TO 6 FEET AND LESS SATURDAY MORNING THROUGH SUNDAY NIGHT. SUN...ANOTHER WEAK FRONT FORECAST TO MOVE THROUGH SATURDAY NIGHT WITH EAST TO SOUTHEAST WINDS SHIFTING TO THE WEST AND NORTHWEST SUNDAY BEHIND THE FRONT. && .PRELIMINARY POINT TEMPS/POPS... DAB 77 50 71 48 / 20 0 10 0 MCO 80 51 76 49 / 20 0 10 0 MLB 81 51 74 51 / 30 0 10 0 VRB 80 52 74 51 / 40 0 10 0 LEE 77 50 74 47 / 20 0 10 0 SFB 78 50 74 49 / 20 0 10 0 ORL 79 52 74 50 / 20 0 10 0 FPR 81 53 74 51 / 40 0 10 0 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...TORNADO WATCH UNTIL 8 AM EST THIS MORNING FOR INDIAN RIVER- MARTIN-NORTHERN BREVARD COUNTY-OKEECHOBEE-OSCEOLA-SOUTHERN BREVARD COUNTY-ST. LUCIE. AM...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR SEBASTIAN INLET TO JUPITER INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 0-20 NM. SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN INLET TO JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM. && $$ SHORT TERM...LASCODY IMPACT WX....WEITLICH LONG TERM....WIMMER
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1131 AM CST TUE FEB 16 2016 .UPDATE... ISSUED AT 1008 AM CST TUE FEB 16 2016 Upper wave continues to dig southeastward and had reached northern Arkansas this morning, with the majority of the associated precipitation skirting just to our south. Radar and surface reports indicating some light freezing rain/snow mixture from about Quincy to Taylorville southward, but this continues to push south with time and should largely be out of west central Illinois by midday. Further north, snow showers were advancing along the I-39 corridor and were starting to edge in the far northern CWA, with a separate piece of energy currently moving through northern Illinois. Have introduced some PoP`s across the northern CWA through the afternoon with this feature, and extended them into areas near Champaign and Danville for early evening before the wave exits the area. Not a lot in the way of ice crystals available in the -10 to -20C elevation per forecast soundings, so snow is less of a concern and the precip type is more of a light rain/drizzle with some freezing potential late this morning. However, temperatures have reached the lower 30s from about Macomb to Paris southward, so the icing potential will be on the wane over the next hour or so. && .SHORT TERM...(Today) ISSUED AT 318 AM CST TUE FEB 16 2016 Next system slated to impact central Illinois is evident on 08z/2am water vapor imagery over eastern Nebraska. Much like the wave that passed by the area yesterday, this particular feature is digging further southward than models had predicted. With the 500mb vort max now progged to track from its current position over eastern Nebraska to northeast Arkansas by 18z, the associated band of light precip has been displaced southward. In fact, the HRRR and Rapid Refresh suggest it will only graze the far S/SE KILX CWA today. As a result, have trimmed PoPs considerably...with locations along/north of a Bloomington to Paris line remaining dry. Highest precip chances will be focused south of I-70 where likely PoPs are warranted. Forecast soundings indicate only shallow boundary layer moisture with a complete lack of ice crystals: therefore, think any precip that occurs will be in liquid form. With surface temps initially in the 20s and lower 30s, some light freezing rain may occur as the precip arrives this morning...primarily along and southwest of a Galesburg to Taylorville line. Icing will be minimal, as temps are expected to climb above freezing by mid to late morning. Fog will also be an issue this morning, although with increasing mid clouds associated with the approaching wave, do not think widespread dense fog will develop. Will therefore not be issuing a Dense Fog Advisory at this time. Instead, a Special Weather Statement addressing the low visibilities has been issued. .LONG TERM...(Tonight through Monday) ISSUED AT 318 AM CST TUE FEB 16 2016 A weak secondary wave will track across the southern Great Lakes tonight, potentially bringing some very light snow or flurries to the northern KILX CWA. Once this feature passes, cool and dry weather will be on tap for Wednesday with high temperatures in the middle to upper 30s. After that, the long-advertised warming trend will finally arrive by the end of the week. A deep upper trough coming onshore across the Pacific Northwest will induce pronounced ridging downstream over the central and eastern CONUS, resulting in much warmer weather. As the pressure gradient tightens between a departing high and an approaching frontal boundary, strong southerly winds will develop on Thursday and Friday. Winds will gust to around 30mph Thursday afternoon, then to between 35 and 40mph on Friday as the front arrives. Thanks to rising upper heights, strong southerly winds, and the return of some sunshine, high temperatures will soar into the 60s by Friday. Once the weak cold front passes, a mild Pacific-origin airmass will prevail through the weekend with highs in the 50s for both Saturday and Sunday. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 1130 AM CST TUE FEB 16 2016 A hole in the IFR conditions has formed late this morning from near KPIA-KCMI, allowing ceilings to rise well above 3,000 feet and visibilities to improve. Some improvement has also recently been noted further south as well. Have kept this in the TAF`s for a couple hours, with deteriorating conditions again mid/late afternoon as widespread MVFR/IFR conditions across Iowa and northwest Illinois track southeast. Not expecting any sort of improvement through the night as an area of high pressure just to the west keeps an inversion in place, but have indicated some modest improvement toward sunrise. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Geelhart SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1008 AM CST TUE FEB 16 2016 .UPDATE... ISSUED AT 1008 AM CST TUE FEB 16 2016 Upper wave continues to dig southeastward and had reached northern Arkansas this morning, with the majority of the associated precipitation skirting just to our south. Radar and surface reports indicating some light freezing rain/snow mixture from about Quincy to Taylorville southward, but this continues to push south with time and should largely be out of west central Illinois by midday. Further north, snow showers were advancing along the I-39 corridor and were starting to edge in the far northern CWA, with a separate piece of energy currently moving through northern Illinois. Have introduced some PoP`s across the northern CWA through the afternoon with this feature, and extended them into areas near Champaign and Danville for early evening before the wave exits the area. Not a lot in the way of ice crystals available in the -10 to -20C elevation per forecast soundings, so snow is less of a concern and the precip type is more of a light rain/drizzle with some freezing potential late this morning. However, temperatures have reached the lower 30s from about Macomb to Paris southward, so the icing potential will be on the wane over the next hour or so. && .SHORT TERM...(Today) ISSUED AT 318 AM CST TUE FEB 16 2016 Next system slated to impact central Illinois is evident on 08z/2am water vapor imagery over eastern Nebraska. Much like the wave that passed by the area yesterday, this particular feature is digging further southward than models had predicted. With the 500mb vort max now progged to track from its current position over eastern Nebraska to northeast Arkansas by 18z, the associated band of light precip has been displaced southward. In fact, the HRRR and Rapid Refresh suggest it will only graze the far S/SE KILX CWA today. As a result, have trimmed PoPs considerably...with locations along/north of a Bloomington to Paris line remaining dry. Highest precip chances will be focused south of I-70 where likely PoPs are warranted. Forecast soundings indicate only shallow boundary layer moisture with a complete lack of ice crystals: therefore, think any precip that occurs will be in liquid form. With surface temps initially in the 20s and lower 30s, some light freezing rain may occur as the precip arrives this morning...primarily along and southwest of a Galesburg to Taylorville line. Icing will be minimal, as temps are expected to climb above freezing by mid to late morning. Fog will also be an issue this morning, although with increasing mid clouds associated with the approaching wave, do not think widespread dense fog will develop. Will therefore not be issuing a Dense Fog Advisory at this time. Instead, a Special Weather Statement addressing the low visibilities has been issued. .LONG TERM...(Tonight through Monday) ISSUED AT 318 AM CST TUE FEB 16 2016 A weak secondary wave will track across the southern Great Lakes tonight, potentially bringing some very light snow or flurries to the northern KILX CWA. Once this feature passes, cool and dry weather will be on tap for Wednesday with high temperatures in the middle to upper 30s. After that, the long-advertised warming trend will finally arrive by the end of the week. A deep upper trough coming onshore across the Pacific Northwest will induce pronounced ridging downstream over the central and eastern CONUS, resulting in much warmer weather. As the pressure gradient tightens between a departing high and an approaching frontal boundary, strong southerly winds will develop on Thursday and Friday. Winds will gust to around 30mph Thursday afternoon, then to between 35 and 40mph on Friday as the front arrives. Thanks to rising upper heights, strong southerly winds, and the return of some sunshine, high temperatures will soar into the 60s by Friday. Once the weak cold front passes, a mild Pacific-origin airmass will prevail through the weekend with highs in the 50s for both Saturday and Sunday. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 455 AM CST TUE FEB 16 2016 Areas of dense fog and low cigs will prevail over the forecast area through the morning hours with only a gradual improvement expected this afternoon. There still is the chance for a brief period of very light snow or freezing rain at SPI in the 14z-17z time frame with any precip after that falling in the form of light rain as surface temperatures rise above freezing. LIFR to VLIFR cigs will dominate into the early afternoon hours with forecast soundings suggesting some improvement to low MVFR cigs in the 20z-23z time frame. May see a few flurries this evening across our northern TAF sites from PIA to CMI but coverage appears to be too low to include in the TAFs this issuance. Surface winds will not be much of a factor this forecast period with a light southeast to east wind today with speeds of 10 kts or less, with winds northwest tonight at 5 to 10 kts. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Geelhart SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
458 AM CST TUE FEB 16 2016 .SHORT TERM...(Today) ISSUED AT 318 AM CST TUE FEB 16 2016 Next system slated to impact central Illinois is evident on 08z/2am water vapor imagery over eastern Nebraska. Much like the wave that passed by the area yesterday, this particular feature is digging further southward than models had predicted. With the 500mb vort max now progged to track from its current position over eastern Nebraska to northeast Arkansas by 18z, the associated band of light precip has been displaced southward. In fact, the HRRR and Rapid Refresh suggest it will only graze the far S/SE KILX CWA today. As a result, have trimmed PoPs considerably...with locations along/north of a Bloomington to Paris line remaining dry. Highest precip chances will be focused south of I-70 where likely PoPs are warranted. Forecast soundings indicate only shallow boundary layer moisture with a complete lack of ice crystals: therefore, think any precip that occurs will be in liquid form. With surface temps initially in the 20s and lower 30s, some light freezing rain may occur as the precip arrives this morning...primarily along and southwest of a Galesburg to Taylorville line. Icing will be minimal, as temps are expected to climb above freezing by mid to late morning. Fog will also be an issue this morning, although with increasing mid clouds associated with the approaching wave, do not think widespread dense fog will develop. Will therefore not be issuing a Dense Fog Advisory at this time. Instead, a Special Weather Statement addressing the low visibilities has been issued. .LONG TERM...(Tonight through Monday) ISSUED AT 318 AM CST TUE FEB 16 2016 A weak secondary wave will track across the southern Great Lakes tonight, potentially bringing some very light snow or flurries to the northern KILX CWA. Once this feature passes, cool and dry weather will be on tap for Wednesday with high temperatures in the middle to upper 30s. After that, the long-advertised warming trend will finally arrive by the end of the week. A deep upper trough coming onshore across the Pacific Northwest will induce pronounced ridging downstream over the central and eastern CONUS, resulting in much warmer weather. As the pressure gradient tightens between a departing high and an approaching frontal boundary, strong southerly winds will develop on Thursday and Friday. Winds will gust to around 30mph Thursday afternoon, then to between 35 and 40mph on Friday as the front arrives. Thanks to rising upper heights, strong southerly winds, and the return of some sunshine, high temperatures will soar into the 60s by Friday. Once the weak cold front passes, a mild Pacific-origin airmass will prevail through the weekend with highs in the 50s for both Saturday and Sunday. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 455 AM CST TUE FEB 16 2016 Areas of dense fog and low cigs will prevail over the forecast area through the morning hours with only a gradual improvement expected this afternoon. There still is the chance for a brief period of very light snow or freezing rain at SPI in the 14z-17z time frame with any precip after that falling in the form of light rain as surface temperatures rise above freezing. LIFR to VLIFR cigs will dominate into the early afternoon hours with forecast soundings suggesting some improvement to low MVFR cigs in the 20z-23z time frame. May see a few flurries this evening across our northern TAF sites from PIA to CMI but coverage appears to be too low to include in the TAFs this issuance. Surface winds will not be much of a factor this forecast period with a light southeast to east wind today with speeds of 10 kts or less, with winds northwest tonight at 5 to 10 kts. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
318 AM CST TUE FEB 16 2016 .SHORT TERM...(Today) ISSUED AT 318 AM CST TUE FEB 16 2016 Next system slated to impact central Illinois is evident on 08z/2am water vapor imagery over eastern Nebraska. Much like the wave that passed by the area yesterday, this particular feature is digging further southward than models had predicted. With the 500mb vort max now progged to track from its current position over eastern Nebraska to northeast Arkansas by 18z, the associated band of light precip has been displaced southward. In fact, the HRRR and Rapid Refresh suggest it will only graze the far S/SE KILX CWA today. As a result, have trimmed PoPs considerably...with locations along/north of a Bloomington to Paris line remaining dry. Highest precip chances will be focused south of I-70 where likely PoPs are warranted. Forecast soundings indicate only shallow boundary layer moisture with a complete lack of ice crystals: therefore, think any precip that occurs will be in liquid form. With surface temps initially in the 20s and lower 30s, some light freezing rain may occur as the precip arrives this morning...primarily along and southwest of a Galesburg to Taylorville line. Icing will be minimal, as temps are expected to climb above freezing by mid to late morning. Fog will also be an issue this morning, although with increasing mid clouds associated with the approaching wave, do not think widespread dense fog will develop. Will therefore not be issuing a Dense Fog Advisory at this time. Instead, a Special Weather Statement addressing the low visibilities has been issued. && .LONG TERM...(Tonight through Monday) ISSUED AT 318 AM CST TUE FEB 16 2016 A weak secondary wave will track across the southern Great Lakes tonight, potentially bringing some very light snow or flurries to the northern KILX CWA. Once this feature passes, cool and dry weather will be on tap for Wednesday with high temperatures in the middle to upper 30s. After that, the long-advertised warming trend will finally arrive by the end of the week. A deep upper trough coming onshore across the Pacific Northwest will induce pronounced ridging downstream over the central and eastern CONUS, resulting in much warmer weather. As the pressure gradient tightens between a departing high and an approaching frontal boundary, strong southerly winds will develop on Thursday and Friday. Winds will gust to around 30mph Thursday afternoon, then to between 35 and 40mph on Friday as the front arrives. Thanks to rising upper heights, strong southerly winds, and the return of some sunshine, high temperatures will soar into the 60s by Friday. Once the weak cold front passes, a mild Pacific-origin airmass will prevail through the weekend with highs in the 50s for both Saturday and Sunday. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1122 PM CST MON FEB 15 2016 Clear skies that occurred in the west have worked their way to the east, but with sfc winds becoming more southeast as the high pressure ridge pushes east of the area, satellite loops show some of the lower clouds beginning to push back to west. This combined with visibilities dropping to below 1sm in some area, making for a tricky forecast overnight. PIA and BMI will remain mostly clear with some scattered cirrus advecting over the sites overnight. CMI, though scattering out some, will have lower clouds to advect back over the site early. SPI and DEC already seeing lower clouds and low vis coming back to the sites due to light easterly winds. Believe these conditions will continue overnight at all sites ahead of the next system coming tomorrow to bring some very light pcpn to the southwestern half of the area. Believe this will effect only SPI and DEC, but with models still trending south with the system, going to have VCSH at these two sites, and have other sites dry for the period. Cigs will drop into MVFR ranges for other sites while SPI and DEC will be IFR until afternoon. Then think MVFR cigs will come to SPI and DEC in the afternoon and continue into evening...along with other sites. Winds will be light and variable to light southeast overnight and then become light and variable during the afternoon as the low pressure area passes to the south. Then wind switch to westerly for the evening. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Auten
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
220 AM CST TUE FEB 16 2016 .UPDATE... MAIN FORECAST CONCERNS ARE THE POTENTIAL FOR DENSE FREEZING FOG OVERNIGHT INTO TUESDAY MORNING AND LIGHT SNOW SHOWERS/LIGHT SNOW TUESDAY AFTERNOON INTO TUESDAY EVENING. DENSE FREEZING FOG POTENTIAL OVERNIGHT INTO TUESDAY: THERE WILL BE NO DRY AIR ADVECTION DUE TO NON EXISTENT PRESSURE GRADIENT/LIGHT WIND REGIME TONIGHT INTO TUESDAY MORNING. SURFACE ANALYSIS SHOWS THE AXIS OF HIGHER 25+ DEGREE DEWPOINTS ALONG AND SOUTH OF INTERSTATE 80. ALREADY SEEING SOME SITES IN CENTRAL ILLINOIS DROP DOWN TO 1/2 MILE VISIBILITY. ANTICIPATE THAT TEMPERATURES WILL SLOWLY FALL WHILE DEWPOINTS DO NOT BUDGE THE REST OF THE NIGHT. LOW LEVEL SATURATION SHOULD THEN ENABLE AREAS OF FREEZING FOG TO BLOSSOM. THERE ARE CONFLICTING SIGNALS ON THE GUIDANCE IN TERMS OF DENSE FOG COVERAGE WITHIN THE CWA. HOWEVER...LAV/LAMP AND EXPERIMENTAL HRRR HAVE CONSISTENTLY FAVORED INCREASING DENSE FOG COVERAGE AFTER MIDNIGHT. FEEL THAT PATTERN RECOGNITION ALSO SUPPORTS THERE BEING AREAS OF DENSE FREEZING FOG OVERNIGHT. ONLY CHANGE TO THE GOING FORECAST WAS TO ADD PATCHY FREEZING FOG THIS EVENING AND ALSO MID TO LATE TUESDAY MORNING. DO NOT HAVE ENOUGH CONFIDENCE YET TO ISSUE A DENSE FOG ADVISORY. PLAN IS TO MONITOR TRENDS THE NEXT FEW HOURS AND PASS ON CONCERNS TO EVENING SHIFT. SNOW SHOWER/LIGHT SNOW POTENTIAL TUES AFTERNOON-TUESDAY EVENING: FAIRLY STRONG CLIPPER WILL MISS CWA TO THE SOUTHWEST ON TUESDAY MORNING. FOCUS WILL THEN SHIFT MID/UPPER TROUGH AXIS EXTENDING SOUTHWARD FROM HUDSON BAY. ELONGATED VORTICITY MAXIMA ALONG THE TROUGH WILL PIVOT ACROSS THE AREA LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. FORECAST SOUNDINGS FOR 18Z GFS DO NOT SHOW SUPERSATURATION OF SNOW GROWTH ZONE...BUT THIS WILL BE COMPENSATED FOR BY DECENT LIFT FROM THE TROUGH/VORT MAX AND ALSO FAIRLY STEEP MIDLEVEL LAPSE RATES. 00Z NAM DID COME INTO BETTER AGREEMENT WITH CONSISTENT DEPICTION ON GLOBAL MODELS. HAVE ADJUSTED POPS UPWARD TO THE CHANCE (UP TO 40%) RANGE FOR NORTHWEST 1/3 OF THE CWA LATE TUESDAY AFTERNOON AND THEN MAINTAINED UP TO 40 POPS TUESDAY EVENING FROM PREVIOUS FORECAST. COULD SEE NEEDING TO ADD LIKELY POPS. TRANSIENT NATURE OF THE TROUGH...LACK OF SUPERSATURATION OF THE DGZ...AND ONLY BRIEF PERIOD OF GOOD LIFT SUGGEST THAT ANY ACCUMULATIONS WILL BE LIGHT AND GENERALLY UP TO 1/2 INCH. IN SUMMARY...MORNING COMMUTE MAY BE IMPACTED BY DENSE FOG AND EVENING COMMUTE COULD HAVE MINOR IMPACTS FROM SNOW SHOWERS/LIGHT SNOW. REST OF FORECAST IS IN GOOD SHAPE AND UPDATED ZONES HAVE BEEN SENT. RC && .SHORT TERM... 228 PM CST THROUGH TUESDAY NIGHT... PRIMARY SHORT TERM CONCERNS INCLUDE CLOUD COVER AND POTENTIAL FOR MORE FOG TONIGHT. STRATUS DECK HOLDING STRONG THIS AFTERNOON WITH ONLY MINOR DIRUNAL IMPROVEMENT NOTED THIS AFTERNOON. LIGHT FLOW...LINGERING LOW LEVEL MOISTURE ALONG WITH SOME VERY WEAK MOIST ADVECTION TONIGHT...COMBINED WITH ADDED BOUNDARY LAYER COOLING DUE TO FRESH SNOW PACK ALL POINT TO CIGS BULDING DOWNWARD AFTER SUNSET AND LIKELY CULMINATING INTO A FOG EVENT OVERNIGHT INTO TUESDAY MORNING. STILL TOO MUCH UNCERTAINTY TO CONSIDER GOING WITH ANY SORT OF FOG ADVISORY...BUT DID INCLUDE POTENTIAL FOR DENSE FREEZING FOG IN THE GRIDS AND WILL ADD TO HWO AS WELL. FOG AND STRATUS LIKELY TO BE SLOW TO BURN OFF AGAIN TUESDAY. HAVE TRENDED TOWARD THE LOWER END OF GUIDANCE TEMPS DUE TO THE ANTICIPATED CLOUD COVER. MAINTAINED SOME SLIGHT CHANCE POPS EXTREME WEST AND SOUTHWEST PORTION OF THE CWA FOR THE CLIPPER PASSING TO OUR WEST DURING THE DAY...BUT TRENDS IN THE GUIDANCE WOULD STRONGLY FAVOR PRECIP WITH THIS FEATURE REMAINING WELL WEST OF OUR CWA. GLOBAL MODELS ARE ALL TRYING TO SQUEEZE OUT SOME LIGHT QPF TUESDAY EVENING WITH SECONDARY WEAKER SHORTWAVE FOLLOWING QUICKLY ON THE HEELS OF THE AFTERNOON CLIPPER...BUT TRACKING FARTHER EAST. FORECAST SOUNDINGS ARE NOT PARTICULARLY IMPRESSIVE OR SATURATED...SO REALLY NOT INCLINED TO GO GUNG-HO WITH POPS TUESDAY EVENING BUT GIVEN MODEL CONSENSUS DID NUDGE THEM UP A BIT. IF ANYTHING FALLS...ACCUMULATION LOOKS TO BE MINIMAL. IZZI && .LONG TERM... 228 PM CST WEDNESDAY THROUGH MONDAY... SHOULD START THE DAY WEDNESDAY SOCKED IN UNDER THE STRATUS DECK...BUT GUIDANCE SUGGESTS WE CLEAR OUT DURING THE AFTERNOON. ALWAYS PRETTY SKEPTICAL OF THIS SIGNAL IN THE MODELS SO TRIED TO NUDGE SKY COVER UP A BIT IN THE GRIDS...BUT WOULDNT BE SHOCKED TO SEE CLEARING BE EVEN SLOWER THAN WHAT I HAVE DEPICTED. TRANSITION AWAY FROM OUR RECENT WEEK LONG SPELL OF TYPICAL CHICAGO WINTER WEATHER SHOULD COMMENCE THURSDAY. TEMPS ON THURSDAY ARE TRICKY AS WARM AIR ADVECTION WILL BE QUICKLY RAMPING UP...BUT AM CONCERNED THAT MUCH OF THE WARMING WILL BE CONFINED TO ABOVE THE BOUNDARY LAYER WITH OUR A GOOD DEAL OF THE WARMING WASTED ON MELTING OUR SNOW COVER. THE LIQUID CONTENT OF THE SNOW IS FAIRLY LOW AND DEEP LOW PRESSURE TRACKING INTO THE UPPER MISSISSIPPI VALLEY THURSDAY NIGHT SHOULD RESULT IN VERY STRONG SOUTHERLY WINDS AND WARM AIR ADVECTION. SUSPECT HIGH TEMPS ON THURSDAY WILL BE REACHED THURSDAY EVENNG AFTER DARK AND CONTINUED STRONG WINDS WILL ADVECT IN DEWPOINTS OF 40F+ WHICH SHOULD MAKE SHORT ORDER OF ANY LINGERING SNOW THURSDAY NIGHT. MEDIUM RANGE GUIDANCE FOR FRIDAY HAS BEEN TRENDING QUICKER WITH THE TIMING OF THE PACIFIC COLD FRONT. WHILE TEMPERATURES WILL LIKELY RISE THROUGH THE 40S AND COULD BE PUCHING 50 FRIDAY MORNING...THE EARLY ARRIVAL OF THE COLD FRONT FRIDAY MAY END UP NIPPING THE CHANCES OF 60F IN THE BUD. NONE-THE-LESS WITH ONLY WEAK COLD AIR ADVECTION BEHIND THE FRONT AND SUCH A WARM START TO THE DAY...HIGHS FRIDAY STILL LOOK SOLIDLY IN THE 50S. VERY STRONG SOUTH BECOMING WESTERLY WINDS SHOULD DAMPER HOW MILD IT FEELS JUST A BIT THOUGH. GENERALLY LOOKING FOR A CONTINUATION OF ABOVE AVERAGE TEMPS THROUGH THE WEEKEND AND PROBABLY INTO THE START OF NEXT WEEK AS WELL. GIVEN THE FAIRLY FAST FLOW...LITTLE TIME SHOULD EXIST FOR APPRECIABLE MOISTURE RETURN SO CHANCES OF SEEING MUCH PRECIP WITH FRONT FRIDAY OR OVER THE WEEKEND LOOKS PRETTY LOW. IZZI && .AVIATION... FOR THE 06Z TAFS... MAIN CONCERN OVERNIGHT CONTINUES TO BE ON POSSIBLE FOG WITH IFR/LIFR CIGS/VSBY AFTER 9Z THROUGH DAYBREAK. IR IMAGERY THIS EVENING SHOWS A NARROW CHANNEL OF CLEAR SKIES THAT HAS PUSHED INTO FAR WESTERN IL...MEANWHILE FURTHER EAST OF THIS AND CLOSER TO THE ORD/MDW A STRATUS LAYER REMAINS. THERE HAVE BEEN A FEW POCKETS OF FREEZING DRIZZLE/LIGHT SNOW THAT HAS BEEN FALLING UNDER THE STRATUS LAYER...HOWEVER THAT HAS BEEN STEADILY TRENDING DOWN. EXPECT TAFS TO REMAIN DRY THROUGH THE OVERNIGHT...WITH THE FOCUS REMAINING ON THE POSSIBLE DEVELOPMENT OF FOG AND LOW CIGS. WHERE THE SKIES HAVE CLEARED TEMPS HAVE BEEN QUICK TO DROP...ALLOWING FOR THE DEVELOPMENT OF FOG AND VSBYS DOWN TO LESS THAN 1 MILE IN A FEW AREAS. GUIDANCE HAS HAD SOME CONSISTENCY WITH FOG MOVING EAST OVERNIGHT AND IMPACTING RFD/DPA AFT 9Z...HOWEVER FURTHER EAST OF THIS AND CLOSER TO ORD/MDW GUIDANCE HAS BEEN STRUGGLING. HAVE OPTED TO TREND A LITTLE HIGHER WITH CIGS/VSBYS HAS IT APPEARS THE STRATUS MAY LINGER LONGER DUE TO THE LACK OF WIND IN THE LOW LEVELS. MANY SURFACE DATA SITES ARE SHOWING WINDS HAVE BECOME CALM TO VRB AT 3KT...AND IT APPEARS THIS WILL PERSIST OVERNIGHT. AROUND DAYBREAK GUIDANCE IS THEN INDICATING THAT ANOTHER SLUG OF LOWER CLOUDS AND POSSIBLE FOG MAY ARRIVE OVER NORTHERN IL/NORTHWEST IN AIRFIELDS...AND COULD PERSIST THROUGH MUCH OF THE MORNING HOURS. HAVE BEEN SLOW TO SHOW AN INCREASE IN THE CURRENT TAF...AND IT IS POSSIBLE LOW CIGS/STRATUS OR IFR CONDS WILL LINGER THROUGH MUCH OF THE DAY TUE. WINDS WILL BE SLOWLY TURNING SOUTHWEST THEN WITH A FRONTAL BOUNDARY ARRIVING THEY WILL TURN TO THE NORTHWEST LATE TUE AFTN. BEACHLER && .MARINE... 219 AM CST RELATIVELY LIGHTER WINDS IN PLACE ACROSS THE LAKE EARLY THIS MORNING WILL LIKELY PERSIST THIS MORNING THROUGH MIDDAY. HOWEVER...DIRECTION WILL BEGIN TO FAVOR A WEST NORTHWEST WIND LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON INTO THIS EVENING AS A TROUGH OF LOW PRESSURE MOVES SOUTHEAST THROUGH THE REGION. NORTHWEST TO NORTH WINDS WILL INCREASE BEHIND THIS SYSTEM TONIGHT WITH SPEEDS INCREASING TO 15 TO 25 KT OVER THE OPEN WATERS...AND WITH A FEW GUSTS TO 30KT POSSIBLE ESPECIALLY ACROSS THE NORTH HALF. THE GRADIENT DOES RELAX ONCE AGAIN ON WEDNESDAY WITH SPEEDS DIMINISHING THROUGH THE DAY. AS LOW PRESSURE DEVELOPS OVER THE CENTRAL U.S. LATER THIS WEEK...WINDS WILL BECOME MORE ORGANIZED OUT OF THE SOUTH WEDNESAY NIGHT INTO THURSDAY. AS THIS SYSTEM TAKES SHAPE AND THEN BEGINS APPROACHING THE REGION...SPEEDS ARE EXPECTED TO INCREASE TO 30KT THURSDAY AND THEN WITH GALES BECOMING LIKELY THURSDAY NIGHT. THESE HIGHER SPEEDS COULD PERSIST ON THE BACKSIDE OF THIS SYSTEM FRIDAY BUT WITH LOWER CONFIDENCE AT THIS TIME...DO BRING SPEEDS BACK DOWN TO THE 30 KT RANGE DURING THAT TIME. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ 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
1053 PM CST MON FEB 15 2016 .UPDATE...905 PM CST MAIN FORECAST CONCERNS ARE THE POTENTIAL FOR DENSE FREEZING FOG OVERNIGHT INTO TUESDAY MORNING AND LIGHT SNOW SHOWERS/LIGHT SNOW TUESDAY AFTERNOON INTO TUESDAY EVENING. DENSE FREEZING FOG POTENTIAL OVERNIGHT INTO TUESDAY: THERE WILL BE NO DRY AIR ADVECTION DUE TO NON EXISTENT PRESSURE GRADIENT/LIGHT WIND REGIME TONIGHT INTO TUESDAY MORNING. SURFACE ANALYSIS SHOWS THE AXIS OF HIGHER 25+ DEGREE DEWPOINTS ALONG AND SOUTH OF INTERSTATE 80. ALREADY SEEING SOME SITES IN CENTRAL ILLINOIS DROP DOWN TO 1/2 MILE VISIBILITY. ANTICIPATE THAT TEMPERATURES WILL SLOWLY FALL WHILE DEWPOINTS DO NOT BUDGE THE REST OF THE NIGHT. LOW LEVEL SATURATION SHOULD THEN ENABLE AREAS OF FREEZING FOG TO BLOSSOM. THERE ARE CONFLICTING SIGNALS ON THE GUIDANCE IN TERMS OF DENSE FOG COVERAGE WITHIN THE CWA. HOWEVER...LAV/LAMP AND EXPERIMENTAL HRRR HAVE CONSISTENTLY FAVORED INCREASING DENSE FOG COVERAGE AFTER MIDNIGHT. FEEL THAT PATTERN RECOGNITION ALSO SUPPORTS THERE BEING AREAS OF DENSE FREEZING FOG OVERNIGHT. ONLY CHANGE TO THE GOING FORECAST WAS TO ADD PATCHY FREEZING FOG THIS EVENING AND ALSO MID TO LATE TUESDAY MORNING. DO NOT HAVE ENOUGH CONFIDENCE YET TO ISSUE A DENSE FOG ADVISORY. PLAN IS TO MONITOR TRENDS THE NEXT FEW HOURS AND PASS ON CONCERNS TO EVENING SHIFT. SNOW SHOWER/LIGHT SNOW POTENTIAL TUES AFTERNOON-TUESDAY EVENING: FAIRLY STRONG CLIPPER WILL MISS CWA TO THE SOUTHWEST ON TUESDAY MORNING. FOCUS WILL THEN SHIFT MID/UPPER TROUGH AXIS EXTENDING SOUTHWARD FROM HUDSON BAY. ELONGATED VORTICITY MAXIMA ALONG THE TROUGH WILL PIVOT ACROSS THE AREA LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. FORECAST SOUNDINGS FOR 18Z GFS DO NOT SHOW SUPERSATURATION OF SNOW GROWTH ZONE...BUT THIS WILL BE COMPENSATED FOR BY DECENT LIFT FROM THE TROUGH/VORT MAX AND ALSO FAIRLY STEEP MIDLEVEL LAPSE RATES. 00Z NAM DID COME INTO BETTER AGREEMENT WITH CONSISTENT DEPICTION ON GLOBAL MODELS. HAVE ADJUSTED POPS UPWARD TO THE CHANCE (UP TO 40%) RANGE FOR NORTHWEST 1/3 OF THE CWA LATE TUESDAY AFTERNOON AND THEN MAINTAINED UP TO 40 POPS TUESDAY EVENING FROM PREVIOUS FORECAST. COULD SEE NEEDING TO ADD LIKELY POPS. TRANSIENT NATURE OF THE TROUGH...LACK OF SUPERSATURATION OF THE DGZ...AND ONLY BRIEF PERIOD OF GOOD LIFT SUGGEST THAT ANY ACCUMULATIONS WILL BE LIGHT AND GENERALLY UP TO 1/2 INCH. IN SUMMARY...MORNING COMMUTE MAY BE IMPACTED BY DENSE FOG AND EVENING COMMUTE COULD HAVE MINOR IMPACTS FROM SNOW SHOWERS/LIGHT SNOW. REST OF FORECAST IS IN GOOD SHAPE AND UPDATED ZONES HAVE BEEN SENT. RC && .SHORT TERM... 228 PM CST THROUGH TUESDAY NIGHT... PRIMARY SHORT TERM CONCERNS INCLUDE CLOUD COVER AND POTENTIAL FOR MORE FOG TONIGHT. STRATUS DECK HOLDING STRONG THIS AFTERNOON WITH ONLY MINOR DIRUNAL IMPROVEMENT NOTED THIS AFTERNOON. LIGHT FLOW...LINGERING LOW LEVEL MOISTURE ALONG WITH SOME VERY WEAK MOIST ADVECTION TONIGHT...COMBINED WITH ADDED BOUNDARY LAYER COOLING DUE TO FRESH SNOW PACK ALL POINT TO CIGS BULDING DOWNWARD AFTER SUNSET AND LIKELY CULMINATING INTO A FOG EVENT OVERNIGHT INTO TUESDAY MORNING. STILL TOO MUCH UNCERTAINTY TO CONSIDER GOING WITH ANY SORT OF FOG ADVISORY...BUT DID INCLUDE POTENTIAL FOR DENSE FREEZING FOG IN THE GRIDS AND WILL ADD TO HWO AS WELL. FOG AND STRATUS LIKELY TO BE SLOW TO BURN OFF AGAIN TUESDAY. HAVE TRENDED TOWARD THE LOWER END OF GUIDANCE TEMPS DUE TO THE ANTICIPATED CLOUD COVER. MAINTAINED SOME SLIGHT CHANCE POPS EXTREME WEST AND SOUTHWEST PORTION OF THE CWA FOR THE CLIPPER PASSING TO OUR WEST DURING THE DAY...BUT TRENDS IN THE GUIDANCE WOULD STRONGLY FAVOR PRECIP WITH THIS FEATURE REMAINING WELL WEST OF OUR CWA. GLOBAL MODELS ARE ALL TRYING TO SQUEEZE OUT SOME LIGHT QPF TUESDAY EVENING WITH SECONDARY WEAKER SHORTWAVE FOLLOWING QUICKLY ON THE HEELS OF THE AFTERNOON CLIPPER...BUT TRACKING FARTHER EAST. FORECAST SOUNDINGS ARE NOT PARTICULARLY IMPRESSIVE OR SATURATED...SO REALLY NOT INCLINED TO GO GUNG-HO WITH POPS TUESDAY EVENING BUT GIVEN MODEL CONSENSUS DID NUDGE THEM UP A BIT. IF ANYTHING FALLS...ACCUMULATION LOOKS TO BE MINIMAL. IZZI && .LONG TERM... 228 PM CST WEDNESDAY THROUGH MONDAY... SHOULD START THE DAY WEDNESDAY SOCKED IN UNDER THE STRATUS DECK...BUT GUIDANCE SUGGESTS WE CLEAR OUT DURING THE AFTERNOON. ALWAYS PRETTY SKEPTICAL OF THIS SIGNAL IN THE MODELS SO TRIED TO NUDGE SKY COVER UP A BIT IN THE GRIDS...BUT WOULDNT BE SHOCKED TO SEE CLEARING BE EVEN SLOWER THAN WHAT I HAVE DEPICTED. TRANSITION AWAY FROM OUR RECENT WEEK LONG SPELL OF TYPICAL CHICAGO WINTER WEATHER SHOULD COMMENCE THURSDAY. TEMPS ON THURSDAY ARE TRICKY AS WARM AIR ADVECTION WILL BE QUICKLY RAMPING UP...BUT AM CONCERNED THAT MUCH OF THE WARMING WILL BE CONFINED TO ABOVE THE BOUNDARY LAYER WITH OUR A GOOD DEAL OF THE WARMING WASTED ON MELTING OUR SNOW COVER. THE LIQUID CONTENT OF THE SNOW IS FAIRLY LOW AND DEEP LOW PRESSURE TRACKING INTO THE UPPER MISSISSIPPI VALLEY THURSDAY NIGHT SHOULD RESULT IN VERY STRONG SOUTHERLY WINDS AND WARM AIR ADVECTION. SUSPECT HIGH TEMPS ON THURSDAY WILL BE REACHED THURSDAY EVENNG AFTER DARK AND CONTINUED STRONG WINDS WILL ADVECT IN DEWPOINTS OF 40F+ WHICH SHOULD MAKE SHORT ORDER OF ANY LINGERING SNOW THURSDAY NIGHT. MEDIUM RANGE GUIDANCE FOR FRIDAY HAS BEEN TRENDING QUICKER WITH THE TIMING OF THE PACIFIC COLD FRONT. WHILE TEMPERATURES WILL LIKELY RISE THROUGH THE 40S AND COULD BE PUCHING 50 FRIDAY MORNING...THE EARLY ARRIVAL OF THE COLD FRONT FRIDAY MAY END UP NIPPING THE CHANCES OF 60F IN THE BUD. NONE-THE-LESS WITH ONLY WEAK COLD AIR ADVECTION BEHIND THE FRONT AND SUCH A WARM START TO THE DAY...HIGHS FRIDAY STILL LOOK SOLIDLY IN THE 50S. VERY STRONG SOUTH BECOMING WESTERLY WINDS SHOULD DAMPER HOW MILD IT FEELS JUST A BIT THOUGH. GENERALLY LOOKING FOR A CONTINUATION OF ABOVE AVERAGE TEMPS THROUGH THE WEEKEND AND PROBABLY INTO THE START OF NEXT WEEK AS WELL. GIVEN THE FAIRLY FAST FLOW...LITTLE TIME SHOULD EXIST FOR APPRECIABLE MOISTURE RETURN SO CHANCES OF SEEING MUCH PRECIP WITH FRONT FRIDAY OR OVER THE WEEKEND LOOKS PRETTY LOW. IZZI && .AVIATION... FOR THE 06Z TAFS... MAIN CONCERN OVERNIGHT CONTINUES TO BE ON POSSIBLE FOG WITH IFR/LIFR CIGS/VSBY AFTER 9Z THROUGH DAYBREAK. IR IMAGERY THIS EVENING SHOWS A NARROW CHANNEL OF CLEAR SKIES THAT HAS PUSHED INTO FAR WESTERN IL...MEANWHILE FURTHER EAST OF THIS AND CLOSER TO THE ORD/MDW A STRATUS LAYER REMAINS. THERE HAVE BEEN A FEW POCKETS OF FREEZING DRIZZLE/LIGHT SNOW THAT HAS BEEN FALLING UNDER THE STRATUS LAYER...HOWEVER THAT HAS BEEN STEADILY TRENDING DOWN. EXPECT TAFS TO REMAIN DRY THROUGH THE OVERNIGHT...WITH THE FOCUS REMAINING ON THE POSSIBLE DEVELOPMENT OF FOG AND LOW CIGS. WHERE THE SKIES HAVE CLEARED TEMPS HAVE BEEN QUICK TO DROP...ALLOWING FOR THE DEVELOPMENT OF FOG AND VSBYS DOWN TO LESS THAN 1 MILE IN A FEW AREAS. GUIDANCE HAS HAD SOME CONSISTENCY WITH FOG MOVING EAST OVERNIGHT AND IMPACTING RFD/DPA AFT 9Z...HOWEVER FURTHER EAST OF THIS AND CLOSER TO ORD/MDW GUIDANCE HAS BEEN STRUGGLING. HAVE OPTED TO TREND A LITTLE HIGHER WITH CIGS/VSBYS HAS IT APPEARS THE STRATUS MAY LINGER LONGER DUE TO THE LACK OF WIND IN THE LOW LEVELS. MANY SURFACE DATA SITES ARE SHOWING WINDS HAVE BECOME CALM TO VRB AT 3KT...AND IT APPEARS THIS WILL PERSIST OVERNIGHT. AROUND DAYBREAK GUIDANCE IS THEN INDICATING THAT ANOTHER SLUG OF LOWER CLOUDS AND POSSIBLE FOG MAY ARRIVE OVER NORTHERN IL/NORTHWEST IN AIRFIELDS...AND COULD PERSIST THROUGH MUCH OF THE MORNING HOURS. HAVE BEEN SLOW TO SHOW AN INCREASE IN THE CURRENT TAF...AND IT IS POSSIBLE LOW CIGS/STRATUS OR IFR CONDS WILL LINGER THROUGH MUCH OF THE DAY TUE. WINDS WILL BE SLOWLY TURNING SOUTHWEST THEN WITH A FRONTAL BOUNDARY ARRIVING THEY WILL TURN TO THE NORTHWEST LATE TUE AFTN. BEACHLER && .MARINE... 228 PM CST DID NOT ISSUE ANY HEADLINES...BUT A GALE WATCH WILL BE NEEDED FOR THURSDAY NIGHT THROUGH FRIDAY EVENING FOR THE SOUTH HALF AND THURSDAY NIGHT FOR THE NORTH HALF. A GALE WATCH WILL LIKELY BE NEEDED FOR THE NSH WATERS FRIDAY AS WELL. LIGHT WINDS ARE EXPECTED THROUGH TUESDAY DUE TO A WEAK PRESSURE GRADIENT. FOG CONTINUES IN THE NSH WATERS...AND FREEZING FOG IS EXPECTED AFTER MIDNIGHT TONIGHT. NORTHWEST TO NORTH WINDS INCREASE TO 30 KT TUESDAY NIGHT AHEAD OF AN APPROACHING HIGH PRESSURE SYSTEM. WINDS DIMINISH UNDER THE HIGH WEDNESDAY AFTERNOON AND NIGHT...AND THEN BECOME SOUTH BEHIND THE HIGH THURSDAY MORNING. WINDS INCREASE TO 30 KT THROUGHOUT THURSDAY. SOUTHERLY GALES ARE EXPECTED ACROSS THE OPEN WATERS THURSDAY NIGHT. A LOW PRESSURE SYSTEM MOVES OVER THE LAKES FRIDAY LEADING TO A POSSIBLE SHORT BREAK IN THE GALES. GUIDANCE DIFFERS ON HOW FAR NORTH THE LOW WILL PASS...AND A MORE NORTHERLY PATH COULD RESULT IN GALES ACROSS THE LAKE FRIDAY. HOWEVER...WENT WITH A MORE SOUTHERLY PATH IN THE FORECAST SO ONLY HAVE GALES CONTINUING FRIDAY ACROSS THE NSH WATERS AND ACROSS THE SOUTHERN HALF OF THE LAKE. WEST WINDS DIMINISH THROUGH SATURDAY. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ 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 QUAD CITIES IA IL
1132 AM CST TUE FEB 16 2016 ...AVIATION UPDATE... .UPDATE... ISSUED AT 558 AM CST TUE FEB 16 2016 THE HRRR AND RAP MODELS NOW KEEP MY EXTREME SOUTHWEST COUNTIES SLIGHTLY SUB FREEZING THROUGH MID MORNING AS THE FREEZING RAIN...SNOW...RAIN MIX MOVES IN. SOME ICING IS LIKELY ON UNTREATED ROADS EARLY TODAY...AND HAVE COORDINATED A SHORT WINTER WEATHER ADVISORY FOR THE SOUTHWESTERN MOST 3 COUNTIES TO COVER THIS EVENT. && .SYNOPSIS... ISSUED AT 305 AM CST TUE FEB 16 2016 THE STORM OF RADICALLY DIFFERENT PATH FORECASTS IN THE PAST FEW DAYS IN MODELS...IS FINALLY MAKING ITS WAY THROUGH THE MIDWEST THIS MORNING. AS OF 3 AM...THE LOW IS FOUND IN TWO CENTERS...ONE IN SOUTHWEST IOWA...AND ANOTHER NEAR KANSAS CITY. THAT STRUCTURE IS LIKELY THE SOURCE OF THE CONTINUATION OF VARIABLE MODEL TRACKS AND EVOLUTION OF THIS STORM. OUR CWA HAS BEEN UNDER THE INFLUENCE IN ILLINOIS OF A VERY NARROW RIDGE...ALLOWING FOR SOME CLEAR SKIES...AND RESULTANT SHARP TEMPERATURES DROP TO THE 9 TO 15 RANGE OVER SNOW...AND PATCHY DENSE FOG TO GO ALONG WITH IT. IOWA...UNDER CLOUDS AND LIGHT SOUTHEAST WINDS...IS HOLDING IN THE UPPER 20S TO LOWER 30S FOR THE MOST PART. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 305 AM CST TUE FEB 16 2016 TODAY IS GOING TO BE A CLOSE CALL...WITH THE VORT AND NARROW BUT RATHER INTENSE WAA PCPN BRUSHING MAINLY SOUTHWEST OF THE CWA LINES...OR FROM CENTRAL IOWA TO CENTRAL MISSOURI. THIS LEAVES MAINLY OUR SOUTHWEST AT RISK FOR MEASURABLE SNOW...AND POSSIBLY RAIN SNOW MIX. OTHER LOCATIONS...ESPECIALLY NORTH WILL SEE SOME EVENTUAL SATURATION FOR VERY LIGHT SNOW. FOR EVERYONE...IT WILL BE CLOUDY...AND SEASONAL DAY IN THE LOWER TO MID 30S...AND WITH DEWPOINTS IN THE 20S AND 30S...WE WILL MELT MORE SNOW THAN ANYTHING THAT FALLS. TODAY WILL BE NET LOSS OF SNOW COVER. FOG...CANNOT BE RULED OUT IN THIS LIGHT CONVERGENT FLOW TODAY...BUT FOR NOW...I WILL KEEP MENTION OF IT TO THE EARLY MORNING...ESPECIALLY SOUTHEAST WHERE SOME PATCHY DENSE FOG IS BEING REPORTED. IF...SNOW DOES ACCUMULATE IN THE SOUTHWEST...UP TO AN INCH APPEARS TO BE THE BEST FIT FOR ACCUMULATIONS. IT IS JUST TOO MILD TO PRODUCE FLUFFY RATIOS TODAY...AND WITH THE MAIN FORCING SHIFTING SOUTH SO EARLY TODAY...THE MAIN EVENT SHOULD BE OVER BY MID MORNING. I WILL KEEP SOME MENTION OF POPS GOING TO EARLY EVENING THOUGH...AS THERE IS WEAK FORCING ALOFT COMBINING WITH CONVERGENT LOW LEVELS. THAT MIGHT BE A QUESTION OF HIGH POP/LOW QPF FOR THE NEXT SHIFT. OTHERWISE...WE SHOULD KEEP THE CLOUD AROUND TONIGHT...WITH WEAK COLD ADVECTION. LOWS IN THE UPPER TEENS TO MID 20S APPEAR ON TRACK FROM NORTH TO SOUTH. ERVIN .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 305 AM CST TUE FEB 16 2016 FORECAST FOCUS ON BIG WARM-UP LATE IN THE WEEK FOLLOWED BY A COOL DOWN BY EARLY NEXT WEEK. LITTLE IF ANY PRECIPITATION EXPECTED. BIG WARM-UP AS THE WEEK PROGRESSES WITH THE AO/NAO GOING POSITIVE AND THE UPPER FLOW BECOMING ZONAL. MUCH OF THE SNOW WILL HAVE MELTED BY THE TIME WE GET TO THURSDAY AND FRIDAY THAT CONFIDENCE IS HIGH WE WILL SEE MAXIMUM TEMPERATURES WELL INTO THE 50S TO LOWER 60S. HOWEVER...THIS IS NOT EVEN CLOSE TO RECORDS WHICH ARE WELL INTO THE 60S TO 70. THE WARMTH WILL BE TEMPERED SOMEWHAT BY STRONG SOUTHWEST WINDS GUSTING OVER 40 MPH IN THE WARM SECTOR. THIS AS A STRONG CYCLONE TRACKS ACROSS MN AND WI WITH MODELS DEPICTING 50+ KNOT WINDS AT 850 MB. ANY PRECIPITATION WILL BE CONFINED TO AREAS WELL NORTH OF THE DVN CWA WHERE THE BETTER FORCING WILL BE LOCATED. THIS WEEKEND INTO EARLY NEXT WEEK...IN THE WAKE OF THE SYSTEM COOLER TEMPERATURES WILL RETURN FOR THE WEEKEND WITH HIGHS BACK DOWN INTO THE 40S TO AROUND 50. NORTHWEST FLOW RETURNS EARLY NEXT WEEK AS A STRONGER COLD FRONT ARRIVES....DROPPING HIGHS DOWN INTO THE 30S. HAASE && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1124 AM CST TUE FEB 16 2016 IFR/MVFR CONDITIONS TO DOMINATE THE NEXT 24 HOURS WITH POSSIBLE LIFR/VLIFR CONDITIONS LATE TONIGHT AND EARLY WEDNESDAY. TRAPPED LOW LEVEL MOISTURE WILL REMAIN IN PLACE WITH LIGHT WINDS BECOMING WEAK NORTHERLY THIS AFTERNOON AND THEN BECOMING LIGHT AND VARAIBLE AGAIN LATE TONIGHT. CEILINGS WILL BE MAINLY AOB 1K AGL WITH PERIODS OF 1-3K AGL POSSIBLE AND CEILINGS AOB 500 FEET POSSIBLE LATE TONIGHT. VISIBILITIES WILL BE MAINLY 2 TO 5 MILES THIS AFTERNOON AND MOST OF THIS EVENING. AFTER 17/06Z...VISIBILITIES MAY FALL TO AOB 1 MILES AND POSSIBLY TO 1/2 MILE IN FOG UNTIL LATE MORNING. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...ERVIN SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...HAASE AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
600 AM CST TUE FEB 16 2016 .UPDATE... ISSUED AT 558 AM CST TUE FEB 16 2016 THE HRRR AND RAP MODELS NOW KEEP MY EXTREME SOUTHWEST COUNTIES SLIGHTLY SUB FREEZING THROUGH MID MORNING AS THE FREEZING RAIN...SNOW...RAIN MIX MOVES IN. SOME ICING IS LIKELY ON UNTREATED ROADS EARLY TODAY...AND HAVE COORDINATED A SHORT WINTER WEATHER ADVISORY FOR THE SOUTHWESTERN MOST 3 COUNTIES TO COVER THIS EVENT. && .SYNOPSIS... ISSUED AT 305 AM CST TUE FEB 16 2016 THE STORM OF RADICALLY DIFFERENT PATH FORECASTS IN THE PAST FEW DAYS IN MODELS...IS FINALLY MAKING ITS WAY THROUGH THE MIDWEST THIS MORNING. AS OF 3 AM...THE LOW IS FOUND IN TWO CENTERS...ONE IN SOUTHWEST IOWA...AND ANOTHER NEAR KANSAS CITY. THAT STRUCTURE IS LIKELY THE SOURCE OF THE CONTINUATION OF VARIABLE MODEL TRACKS AND EVOLUTION OF THIS STORM. OUR CWA HAS BEEN UNDER THE INFLUENCE IN ILLINOIS OF A VERY NARROW RIDGE...ALLOWING FOR SOME CLEAR SKIES...AND RESULTANT SHARP TEMPERATURES DROP TO THE 9 TO 15 RANGE OVER SNOW...AND PATCHY DENSE FOG TO GO ALONG WITH IT. IOWA...UNDER CLOUDS AND LIGHT SOUTHEAST WINDS...IS HOLDING IN THE UPPER 20S TO LOWER 30S FOR THE MOST PART. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 305 AM CST TUE FEB 16 2016 TODAY IS GOING TO BE A CLOSE CALL...WITH THE VORT AND NARROW BUT RATHER INTENSE WAA PCPN BRUSHING MAINLY SOUTHWEST OF THE CWA LINES...OR FROM CENTRAL IOWA TO CENTRAL MISSOURI. THIS LEAVES MAINLY OUR SOUTHWEST AT RISK FOR MEASURABLE SNOW...AND POSSIBLY RAIN SNOW MIX. OTHER LOCATIONS...ESPECIALLY NORTH WILL SEE SOME EVENTUAL SATURATION FOR VERY LIGHT SNOW. FOR EVERYONE...IT WILL BE CLOUDY...AND SEASONAL DAY IN THE LOWER TO MID 30S...AND WITH DEWPOINTS IN THE 20S AND 30S...WE WILL MELT MORE SNOW THAN ANYTHING THAT FALLS. TODAY WILL BE NET LOSS OF SNOW COVER. FOG...CANNOT BE RULED OUT IN THIS LIGHT CONVERGENT FLOW TODAY...BUT FOR NOW...I WILL KEEP MENTION OF IT TO THE EARLY MORNING...ESPECIALLY SOUTHEAST WHERE SOME PATCHY DENSE FOG IS BEING REPORTED. IF...SNOW DOES ACCUMULATE IN THE SOUTHWEST...UP TO AN INCH APPEARS TO BE THE BEST FIT FOR ACCUMULATIONS. IT IS JUST TOO MILD TO PRODUCE FLUFFY RATIOS TODAY...AND WITH THE MAIN FORCING SHIFTING SOUTH SO EARLY TODAY...THE MAIN EVENT SHOULD BE OVER BY MID MORNING. I WILL KEEP SOME MENTION OF POPS GOING TO EARLY EVENING THOUGH...AS THERE IS WEAK FORCING ALOFT COMBINING WITH CONVERGENT LOW LEVELS. THAT MIGHT BE A QUESTION OF HIGH POP/LOW QPF FOR THE NEXT SHIFT. OTHERWISE...WE SHOULD KEEP THE CLOUD AROUND TONIGHT...WITH WEAK COLD ADVECTION. LOWS IN THE UPPER TEENS TO MID 20S APPEAR ON TRACK FROM NORTH TO SOUTH. ERVIN .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 305 AM CST TUE FEB 16 2016 FORECAST FOCUS ON BIG WARM-UP LATE IN THE WEEK FOLLOWED BY A COOL DOWN BY EARLY NEXT WEEK. LITTLE IF ANY PRECIPITATION EXPECTED. BIG WARM-UP AS THE WEEK PROGRESSES WITH THE AO/NAO GOING POSITIVE AND THE UPPER FLOW BECOMING ZONAL. MUCH OF THE SNOW WILL HAVE MELTED BY THE TIME WE GET TO THURSDAY AND FRIDAY THAT CONFIDENCE IS HIGH WE WILL SEE MAXIMUM TEMPERATURES WELL INTO THE 50S TO LOWER 60S. HOWEVER...THIS IS NOT EVEN CLOSE TO RECORDS WHICH ARE WELL INTO THE 60S TO 70. THE WARMTH WILL BE TEMPERED SOMEWHAT BY STRONG SOUTHWEST WINDS GUSTING OVER 40 MPH IN THE WARM SECTOR. THIS AS A STRONG CYCLONE TRACKS ACROSS MN AND WI WITH MODELS DEPICTING 50+ KNOT WINDS AT 850 MB. ANY PRECIPITATION WILL BE CONFINED TO AREAS WELL NORTH OF THE DVN CWA WHERE THE BETTER FORCING WILL BE LOCATED. THIS WEEKEND INTO EARLY NEXT WEEK...IN THE WAKE OF THE SYSTEM COOLER TEMPERATURES WILL RETURN FOR THE WEEKEND WITH HIGHS BACK DOWN INTO THE 40S TO AROUND 50. NORTHWEST FLOW RETURNS EARLY NEXT WEEK AS A STRONGER COLD FRONT ARRIVES....DROPPING HIGHS DOWN INTO THE 30S. HAASE && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 529 AM CST TUE FEB 16 2016 A STORM SYSTEM WILL MAINLY SWEEP SOUTHWEST OF EASTERN IOWA TODAY...RESULTING IN WIDESPREAD LOW CLOUDS...LIGHT FOG...AND SCATTERED AREAS OF SNOW. THIS WILL MAINLY IMPACT CIGS THROUGH TONIGHT...AS THEY VARY FROM 300 TO 800 FT THIS MORNING...THOUGH SOME VFR POCKETS ARE ALSO POSSIBLE. THIS VARIABLE COMBINATION SHOULD BECOME MORE STEADY DURING THE DAY. MVFR CLOUDS SHOULD DOMINATE THE AFTERNOON INTO TONIGHT. LIGHT FOG...AND SOME SNOW WILL LOWER VISIBILITIES TO 2 TO 5 MILES THROUGH THE DAY. DRY CONDITIONS ARE EXPECTED TONIGHT WITH MVFR POSSIBLY LIFTING TO VFR WITH TIME. ERVIN && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WINTER WEATHER ADVISORY UNTIL 10 AM CST THIS MORNING FOR VAN BUREN. IL...NONE. MO...WINTER WEATHER ADVISORY UNTIL 10 AM CST THIS MORNING FOR CLARK- SCOTLAND. && $$ UPDATE...ERVIN SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...HAASE AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
120 PM MST TUE FEB 16 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM MST TUE FEB 16 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW NW FLOW STILL IN PLACE ACROSS THE PLAINS WITH A SHORTWAVE TROUGH CURRENTLY OVER CENTRAL NEBRASKA. AT THE SURFACE A COLD FRONT HAS PUSHED THROUGH OUR CWA WITH HIGH PRESSURE NOW BUILDING FROM THE NEBRASKA PANHANDLE INTO NE COLORADO AND NW KANSAS. THE MAIN CONCERN THIS FORECAST UPDATE WAS ON POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS MAINLY THURSDAY...SEE FIRE WEATHER DISCUSSION FOR DETAILS. EARLY THIS MORNING...RADAR CONTINUES TO SHOW LIGHT RETURNS ASSOCIATED WITH MID LEVEL FRONTOGENESIS...WITH VIRGA OR A FEW SPRINKLES. DRIER AND MUCH MORE STABLE AIR BEHIND EXITING SHORTWAVE TROUGH HAS HELPED WEAKEN THIS ACTIVITY AND SHORT RANGE GUIDANCE CONTINUES TO SHOW A DIMINISHING TREND THROUGH 12Z. TODAY-THURSDAY NIGHT...STRONG H5 RIDGE OVER THE WESTERN US COAST WILL SLIDE EASTWARD OVER THE CENTRAL ROCKIES AND PLAINS THROUGH MID WEEK. THIS WILL SUPPORT A VERY DEEP/DRY AIR MASS AND UNSEASONABLY WARM TEMPERATURES THROUGH THESE PERIODS. TEMPS MAY BE A LITTLE COOLER TODAY THAN YESTERDAY DUE TO POST FRONTAL AIR MASS THROUGH MIDDAY...HOWEVER AS LEE TROUGH DEVELOPS LATE THIS AFTERNOON WE COULD ACTUALLY END UP PRETTY SIMILAR IF OPAQUE CIRRUS DOESNT COMPLICATE THINGS. WEDNESDAY SHOULD BE SUNNY AND WARMER WITH HIGHS IN THE 60S...POSSIBLE AROUND 70 IN OUR SOUTH. DEEP SW FLOW DEVELOPS ON BACK EDGE OF RIDGE THURSDAY A BUILDING TROUGH WILL RESULT IN DEEP SW FLOW ACROSS THE CENTRAL ROCKIES/PLAINS. MODELS CONTINUE TO SHOW VERY STRONG WAA WITH THIS PATTERN AS STRONGER LEE TROUGH DEVELOPS. THIS WILL RESULT IN HIGH TEMPERATURE RECORDS BEING MET AT A FEW LOCATIONS. A DRY COLD FRONT WILL MOVE THROUGH THE REGION WITH SHORTWAVE TROUGH PASSING JUST NORTH OF OUR CWA. DEEP DRY AIR MASS IN PLACE WILL PRECLUDE ANY PRECIP CHANCES. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 115 PM MST TUE FEB 16 2016 H5 RIDGE AXIS REMAINS IN POSITION OVER THE CWA ON THURSDAY ENHANCED BY A QUASI STATIONARY LOW PRESSURE AREA SITUATED IN THE GULF OF ALASKA AS WELL AS A TROUGH OVER THE EASTERN US. TEMPERATURES WILL BE WELL ABOVE NORMAL ON THURSDAY AS THE RIDGE PREVAILS ACROSS THE REGION. PROGRESSIVE FLOW ALONG THE SOUTHERN PERIPHERY OF THE RIDGE WILL TRIGGER SHORTWAVE DEVELOPMENT ON THE LEE SIDE OF THE ROCKIES EARLY ON FRIDAY AS THE RIDGE BREAKS DOWN AND MOVES EAST. WEST TO SOUTHWEST FLOW ALOFT WILL ALLOW FOR DRY AIR TO ACCOMPANY THE SHORTWAVE THUS INHIBITING ANY PRECIPITATION FROM FORMING AS IT TRAVERSES THE REGION. THERE IS GOOD AGREEMENT IN THE GUIDANCE UPON THE TIMING AND PLACEMENT OF FRIDAYS SHORTWAVE THUS THERE IS HIGH CONFIDENCE IN DRY CONDITIONS ON FRIDAY WITH ABOVE NORMAL TEMPERATURES. PROGRESSIVE FLOW AND WESTERLY WINDS ALOFT CONTINUE INTO SATURDAY AND EARLY SUNDAY WITH DRY WEATHER EXPECTED BOTH DAYS. COOLER AIR WILL MOVE IN ON SUNDAY IN RESPONSE TO ANOTHER FAST MOVING WEAK SHORTWAVE. FLOW ALOFT WILL SHIFT TO A WEST TO NORTHWESTERLY DIRECTION VERY LATE ON SUNDAY AND INTO MONDAY AS A RIDGE TAKES SHAPE IN THE WEST AND SOUTHWEST US. GUIDANCE SUGGESTS A BRIEF PERIOD OF LIGHT PRECIPITATION AS THE NEXT SHORTWAVE DIVES SOUTHEASTWARD EARLY MONDAY AND INTO TUESDAY HOWEVER CONFIDENCE IS LOW AT THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1032 AM MST TUE FEB 16 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH MCK AND GLD. A FEW MID-LEVEL CLOUDS AROUND 7KFT AGL WILL MOVE THROUGH THE CENTRAL HIGH PLAINS REGION BETWEEN 21Z-06Z...OTHERWISE ONLY HIGH CLOUDS ARE ANTICIPATED WITH GENERALLY LIGHT WESTERLY WINDS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR KSZ027>029-041-042. CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR COZ254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...TL AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1108 AM MST TUE FEB 16 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM MST TUE FEB 16 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW NW FLOW STILL IN PLACE ACROSS THE PLAINS WITH A SHORTWAVE TROUGH CURRENTLY OVER CENTRAL NEBRASKA. AT THE SURFACE A COLD FRONT HAS PUSHED THROUGH OUR CWA WITH HIGH PRESSURE NOW BUILDING FROM THE NEBRASKA PANHANDLE INTO NE COLORADO AND NW KANSAS. THE MAIN CONCERN THIS FORECAST UPDATE WAS ON POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS MAINLY THURSDAY...SEE FIRE WEATHER DISCUSSION FOR DETAILS. EARLY THIS MORNING...RADAR CONTINUES TO SHOW LIGHT RETURNS ASSOCIATED WITH MID LEVEL FRONTOGENESIS...WITH VIRGA OR A FEW SPRINKLES. DRIER AND MUCH MORE STABLE AIR BEHIND EXITING SHORTWAVE TROUGH HAS HELPED WEAKEN THIS ACTIVITY AND SHORT RANGE GUIDANCE CONTINUES TO SHOW A DIMINISHING TREND THROUGH 12Z. TODAY-THURSDAY NIGHT...STRONG H5 RIDGE OVER THE WESTERN US COAST WILL SLIDE EASTWARD OVER THE CENTRAL ROCKIES AND PLAINS THROUGH MID WEEK. THIS WILL SUPPORT A VERY DEEP/DRY AIR MASS AND UNSEASONABLY WARM TEMPERATURES THROUGH THESE PERIODS. TEMPS MAY BE A LITTLE COOLER TODAY THAN YESTERDAY DUE TO POST FRONTAL AIR MASS THROUGH MIDDAY...HOWEVER AS LEE TROUGH DEVELOPS LATE THIS AFTERNOON WE COULD ACTUALLY END UP PRETTY SIMILAR IF OPAQUE CIRRUS DOESNT COMPLICATE THINGS. WEDNESDAY SHOULD BE SUNNY AND WARMER WITH HIGHS IN THE 60S...POSSIBLE AROUND 70 IN OUR SOUTH. DEEP SW FLOW DEVELOPS ON BACK EDGE OF RIDGE THURSDAY A BUILDING TROUGH WILL RESULT IN DEEP SW FLOW ACROSS THE CENTRAL ROCKIES/PLAINS. MODELS CONTINUE TO SHOW VERY STRONG WAA WITH THIS PATTERN AS STRONGER LEE TROUGH DEVELOPS. THIS WILL RESULT IN HIGH TEMPERATURE RECORDS BEING MET AT A FEW LOCATIONS. A DRY COLD FRONT WILL MOVE THROUGH THE REGION WITH SHORTWAVE TROUGH PASSING JUST NORTH OF OUR CWA. DEEP DRY AIR MASS IN PLACE WILL PRECLUDE ANY PRECIP CHANCES. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 225 AM MST TUE FEB 16 2016 FOR THE EXTENDED PERIOD...DRY CONDITIONS ACROSS THE FORECAST AREA CONTINUE AS BROAD H5 RIDGE SEEN EARLIER IN THE WEEK BEGINS TO BREAKS DOWN/FLATTEN ALLOWING FOR ZONAL FLOW OVER THE PLAINS/ROCKIES REGION. A WEAK SHORTWAVE PASSES SOUTH OF THE REGION SUNDAY NIGHT INTO NEXT MONDAY...FOLLOWED BY A STRONGER SYSTEM COMING OFF THE ROCKIES MONDAY NIGHT ON INTO TUESDAY. SOME MODEL DIFFERENCES IN AVAILABLE QPF WITH ITS PASSAGE...BUT HAVE STAYED CLOSE TO GFS GIVING AREA A CHANCE FOR LIGHT RAIN BASED ON EXPECTED TEMPS DURING PASSAGE. THIS SYSTEM LOOKS TO HAVE POTENTIAL FOR STRONG GUSTY WINDS BEHIND IT AS IT TRAVERSES AREA. CURRENT MODEL GUIDANCE BRING 25-35 MPH POTENTIAL. FOR TEMPS...ABOVE NORMAL CONDITIONS EXPECTED WITH HIGHS REACHING INTO THE 60S FRIDAY/SATURDAY AHEAD OF THE AFOREMENTIONED TROUGHS...THEN 50S FOR SUNDAY THRU TUESDAY AS SLIGHTLY COOLER AIR IS DRAGGED INTO AREA WITH EACH SYSTEM PASSAGE. OVERNIGHT LOWS WILL DROP FROM THE 30S INTO THE 20S FOR THE SAME ABOVE MENTIONED REASON...ARRIVAL OF COOLER/COLDER AIR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1032 AM MST TUE FEB 16 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH MCK AND GLD. A FEW MID-LEVEL CLOUDS AROUND 7KFT AGL WILL MOVE THROUGH THE CENTRAL HIGH PLAINS REGION BETWEEN 21Z-06Z...OTHERWISE ONLY HIGH CLOUDS ARE ANTICIPATED WITH GENERALLY LIGHT WESTERLY WINDS. && .FIRE WEATHER... ISSUED AT 1045 AM MST TUE FEB 16 2016 ON THURSDAY...WITH DRY CONDITIONS AND GUSTY WINDS EXPECTED MAINLY ACROSS THE SOUTHWESTERN PORTION OF THE FORECAST AREA...EXTENDING NORTH AND EAST FROM THERE...A FIRE WEATHER WATCH REMAINS IN EFFECT ACROSS THE SOUTHERN EXTENT OF THE FORECAST AREA. AREAS WITHIN THE CURRENT FIRE WEATHER WATCH AREA HAVE DRY FINE FUELS THAT ARE AVAILABLE TO BURN SINCE THAT AREA DID NOT RECEIVE THE SIGNIFICANT SNOW AREAS FURTHER NORTH RECEIVED DURING RECENT WINTER PRECIPITATION EVENTS. HOWEVER...THE FUEL MOISTURE REMAINS QUESTIONABLE ACROSS AREAS TO THE NORTH OF THE WATCH AREA. DUE TO RECENT MELTING OF THE SNOW COVER AND FROZEN SUBSOIL CONDITIONS...THE TOPMOST LAYER OF SOIL AND COVER OF FINE FUELS ABOVE THAT IS STILL WET. IT REMAINS QUESTIONABLE WHETHER OR NOT THESE FINE FUELS WILL HAVE THE OPPORTUNITY TO DRY AND BECOME AVAILABLE TO BURN BEFORE THURSDAY. WILL KEEP THE CURRENT WATCH AREA INTACT FOR NOW WITH A POSSIBLE EXTENSION OF THE WATCH AREA OR EVENTUAL RED FLAG WARNING ON THURSDAY IF CONDITIONS CHANGE OVER THE NEXT COUPLE OF DAYS. && .CLIMATE... ISSUED AT 314 AM MST TUE FEB 16 2016 DAILY RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES THURSDAY. SITE.............RECORD...CURRENT FORECAST GOODLAND, KS.......74...........78 MCCOOK, NE.........82...........76 BURLINGTON,CO......74...........76 HILL CITY,KS.......75...........80 COLBY, KS..........81...........78 TRIBUNE, KS........79...........79 YUMA, CO...........73...........74 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR KSZ027>029-041-042. CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR COZ254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JN AVIATION...LOCKHART FIRE WEATHER...LOCKHART CLIMATE...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1045 AM MST TUE FEB 16 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM MST TUE FEB 16 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW NW FLOW STILL IN PLACE ACROSS THE PLAINS WITH A SHORTWAVE TROUGH CURRENTLY OVER CENTRAL NEBRASKA. AT THE SURFACE A COLD FRONT HAS PUSHED THROUGH OUR CWA WITH HIGH PRESSURE NOW BUILDING FROM THE NEBRASKA PANHANDLE INTO NE COLORADO AND NW KANSAS. THE MAIN CONCERN THIS FORECAST UPDATE WAS ON POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS MAINLY THURSDAY...SEE FIRE WEATHER DISCUSSION FOR DETAILS. EARLY THIS MORNING...RADAR CONTINUES TO SHOW LIGHT RETURNS ASSOCIATED WITH MID LEVEL FRONTOGENESIS...WITH VIRGA OR A FEW SPRINKLES. DRIER AND MUCH MORE STABLE AIR BEHIND EXITING SHORTWAVE TROUGH HAS HELPED WEAKEN THIS ACTIVITY AND SHORT RANGE GUIDANCE CONTINUES TO SHOW A DIMINISHING TREND THROUGH 12Z. TODAY-THURSDAY NIGHT...STRONG H5 RIDGE OVER THE WESTERN US COAST WILL SLIDE EASTWARD OVER THE CENTRAL ROCKIES AND PLAINS THROUGH MID WEEK. THIS WILL SUPPORT A VERY DEEP/DRY AIR MASS AND UNSEASONABLY WARM TEMPERATURES THROUGH THESE PERIODS. TEMPS MAY BE A LITTLE COOLER TODAY THAN YESTERDAY DUE TO POST FRONTAL AIR MASS THROUGH MIDDAY...HOWEVER AS LEE TROUGH DEVELOPS LATE THIS AFTERNOON WE COULD ACTUALLY END UP PRETTY SIMILAR IF OPAQUE CIRRUS DOESNT COMPLICATE THINGS. WEDNESDAY SHOULD BE SUNNY AND WARMER WITH HIGHS IN THE 60S...POSSIBLE AROUND 70 IN OUR SOUTH. DEEP SW FLOW DEVELOPS ON BACK EDGE OF RIDGE THURSDAY A BUILDING TROUGH WILL RESULT IN DEEP SW FLOW ACROSS THE CENTRAL ROCKIES/PLAINS. MODELS CONTINUE TO SHOW VERY STRONG WAA WITH THIS PATTERN AS STRONGER LEE TROUGH DEVELOPS. THIS WILL RESULT IN HIGH TEMPERATURE RECORDS BEING MET AT A FEW LOCATIONS. A DRY COLD FRONT WILL MOVE THROUGH THE REGION WITH SHORTWAVE TROUGH PASSING JUST NORTH OF OUR CWA. DEEP DRY AIR MASS IN PLACE WILL PRECLUDE ANY PRECIP CHANCES. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 225 AM MST TUE FEB 16 2016 FOR THE EXTENDED PERIOD...DRY CONDITIONS ACROSS THE FORECAST AREA CONTINUE AS BROAD H5 RIDGE SEEN EARLIER IN THE WEEK BEGINS TO BREAKS DOWN/FLATTEN ALLOWING FOR ZONAL FLOW OVER THE PLAINS/ROCKIES REGION. A WEAK SHORTWAVE PASSES SOUTH OF THE REGION SUNDAY NIGHT INTO NEXT MONDAY...FOLLOWED BY A STRONGER SYSTEM COMING OFF THE ROCKIES MONDAY NIGHT ON INTO TUESDAY. SOME MODEL DIFFERENCES IN AVAILABLE QPF WITH ITS PASSAGE...BUT HAVE STAYED CLOSE TO GFS GIVING AREA A CHANCE FOR LIGHT RAIN BASED ON EXPECTED TEMPS DURING PASSAGE. THIS SYSTEM LOOKS TO HAVE POTENTIAL FOR STRONG GUSTY WINDS BEHIND IT AS IT TRAVERSES AREA. CURRENT MODEL GUIDANCE BRING 25-35 MPH POTENTIAL. FOR TEMPS...ABOVE NORMAL CONDITIONS EXPECTED WITH HIGHS REACHING INTO THE 60S FRIDAY/SATURDAY AHEAD OF THE AFOREMENTIONED TROUGHS...THEN 50S FOR SUNDAY THRU TUESDAY AS SLIGHTLY COOLER AIR IS DRAGGED INTO AREA WITH EACH SYSTEM PASSAGE. OVERNIGHT LOWS WILL DROP FROM THE 30S INTO THE 20S FOR THE SAME ABOVE MENTIONED REASON...ARRIVAL OF COOLER/COLDER AIR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1032 AM MST TUE FEB 16 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH MCK AND GLD. A FEW MID-LEVEL CLOUDS AROUND 7KFT AGL WILL MOVE THROUGH THE CENTRAL HIGH PLAINS REGION BETWEEN 21Z-06Z...OTHERWISE ONLY HIGH CLOUDS ARE ANTICIPATED WITH GENERALLY LIGHT WESTERLY WINDS. && .FIRE WEATHER... ISSUED AT 314 AM MST TUE FEB 16 2016 CONSIDERING THE VERY DRY AIR MASS ADVERTISED BY GUIDANCE WE COULD SEE NEAR CRITICAL CRITERIA RH MET IN OUR FAR SW WEDNESDAY AFTERNOON...BUT THIS SHOULDNT NECESSITATE A WATCH ISSUANCE CONSIDERING THE MARGINAL NATURE OF THE RH/WINDS. STRONG UNIDIRECTIONAL GRADIENT (STRONG WINDS)...GOOD MIXING...RECORD HIGH TEMPERATURES...AND VERY DRY AIR SHOULD MAKE CRITICAL CRITERIA CROSSOVER OF RH/WINDS A SLAM DUNK THURSDAY FOR SW PORTIONS OF OUR CWA (ROUGHLY SW OF YUMA TO GOVE LINE). AT THIS JUNCTURE THE BIGGEST QUESTION ON WHERE TO DRAW UP A FIRE WEATHER WATCH THURSDAY IS FUELS. OVER THE NEXT FEW DAYS FURTHER MELTING/CURING SHOULD TAKE PLACE. LOCATIONS FURTHER NORTH AND EAST MAY STILL BE WET ENOUGH FROM RECENT SNOW MELT THAT WITHOUT COLLABORATING WITH PARTNERS IM NOT COMFORTABLE ISSUING ANY HAZARD PRODUCTS FOR THOSE LOCATIONS. IM MORE CONFIDENT THAT LOCATIONS ALONG/SOUTH OF HWY 40 WILL HAVE AMPLE OPPORTUNITY TO CURE AND THE MAJORITY OF FUELS WILL BE READY TO GO. I DECIDED TO LIMIT A FIRE WEATHER WATCH TO THESE SOUTHERN AREAS DURING THIS UPDATE...AND WILL ALLOW COORDINATION WITH PARTNERS DURING DAY SHIFT TO FINE TUNE FUELS EXPECTATIONS NORTH OF THIS. && .CLIMATE... ISSUED AT 314 AM MST TUE FEB 16 2016 DAILY RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES THURSDAY. SITE.............RECORD...CURRENT FORECAST GOODLAND, KS.......74...........78 MCCOOK, NE.........82...........76 BURLINGTON,CO......74...........76 HILL CITY,KS.......75...........80 COLBY, KS..........81...........78 TRIBUNE, KS........79...........79 YUMA, CO...........73...........74 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR KSZ027>029-041-042. CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR COZ254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JN AVIATION...LOCKHART FIRE WEATHER...DR CLIMATE...DR
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
614 AM CST TUE FEB 16 2016 ...UPDATED AVIATION SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 420 AM CST TUE FEB 16 2016 Upper level northwesterly flow continues over the central CONUS this morning. A fast moving shortwave trough embedded in the flow was tracking southeast over Nebraska and Kansas into Missouri overnight. This system had brought some scattered light rain showers and sprinkles to portions of central Kansas around Hays earlier tonight. A cool front had pushed through western Kansas with gusty northwest winds behind it. Latest radar trends show the bulk of this precipitation moving into eastern Kansas while lingering precipitation echoes over the western part of the state continue to dissipate. For the rest of today, expect to see the gusty north winds continuing for a while this morning but winds should diminish and become light/variable by midday as surface high pressure moves into the area. Some weak southerly return flow should develop out toward the Colorado border as surface low pressure develops in the lee of the Rockies. Temperatures will be a little cooler today with highs ranging from the mid 50s around Hays to around 60 at Elkhart. Southerly flow continues into tonight but another weak disturbance could push the Colorado surface trough out into western Kansas late tonight. .LONG TERM...(Wednesday THROUGH Monday) ISSUED AT 420 AM CST TUE FEB 16 2016 An upper level ridge will move out of the western states over the Plains by Wednesday evening. A strong shortwave trough will move east on the heels of the ridge and move out over the northern and central Plains Thursday evening. Temperatures will be warming across western Kansas through midweek with highs on Thursday warming well into the 80s over parts of southwest Kansas under strong low level southwesterly downslope flow. As this shortwave moves through, a cold front will push across western Kansas Thursday night. Temperatures will cool somewhat behind the front on Friday and Saturday but should still be above normal. Through the weekend, the upper flow continues to be more zonal. A weak upper shortwave moves out over the central Plains late in the weekend. At this time it appears that any significant moisture return will stay just to the south of Kansas. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Wednesday MORNING) ISSUED AT 559 AM CST TUE FEB 16 2016 The stratus moving southwest across north central Kansas begins to retreat back to the northeast based on the HRRR ceilings trend. Breezy northwest winds will prevail through the morning before becoming light in the afternoon. Light surface winds will then veer overnight to the south by early Wednesday. && .FIRE WEATHER... ISSUED AT 420 AM CST TUE FEB 16 2016 Very warm and windy conditions are expected to develop across western and central Kansas on Thursday. Relative humidity levels are expected to fall into the single digits and lower teens across a good part of southwest Kansas. With winds increasing during the day, critical wildfire conditions are expected to develop during the afternoon hours. A fire weather watch has been issued. && .PRELIMINARY POINT TEMPS/POPS... DDC 58 33 68 43 / 0 0 0 0 GCK 58 32 68 39 / 0 0 0 0 EHA 61 34 72 43 / 0 0 0 0 LBL 60 33 72 43 / 0 0 0 0 HYS 54 32 64 41 / 0 0 0 0 P28 59 33 68 45 / 0 0 0 0 && .DDC Watches/Warnings/Advisories... Fire Weather Watch Thursday afternoon for KSZ030-031-043>046- 061>066-074>081-084>090. && $$ SHORT TERM...Gerard LONG TERM...Gerard AVIATION...Russell FIRE WEATHER...Gerard
AREA FORECAST DISCUSSION
NWS GOODLAND KS
434 AM MST TUE FEB 16 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM MST TUE FEB 16 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW NW FLOW STILL IN PLACE ACROSS THE PLAINS WITH A SHORTWAVE TROUGH CURRENTLY OVER CENTRAL NEBRASKA. AT THE SURFACE A COLD FRONT HAS PUSHED THROUGH OUR CWA WITH HIGH PRESSURE NOW BUILDING FROM THE NEBRASKA PANHANDLE INTO NE COLORADO AND NW KANSAS. THE MAIN CONCERN THIS FORECAST UPDATE WAS ON POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS MAINLY THURSDAY...SEE FIRE WEATHER DISCUSSION FOR DETAILS. EARLY THIS MORNING...RADAR CONTINUES TO SHOW LIGHT RETURNS ASSOCIATED WITH MID LEVEL FRONTOGENESIS...WITH VIRGA OR A FEW SPRINKLES. DRIER AND MUCH MORE STABLE AIR BEHIND EXITING SHORTWAVE TROUGH HAS HELPED WEAKEN THIS ACTIVITY AND SHORT RANGE GUIDANCE CONTINUES TO SHOW A DIMINISHING TREND THROUGH 12Z. TODAY-THURSDAY NIGHT...STRONG H5 RIDGE OVER THE WESTERN US COAST WILL SLIDE EASTWARD OVER THE CENTRAL ROCKIES AND PLAINS THROUGH MID WEEK. THIS WILL SUPPORT A VERY DEEP/DRY AIR MASS AND UNSEASONABLY WARM TEMPERATURES THROUGH THESE PERIODS. TEMPS MAY BE A LITTLE COOLER TODAY THAN YESTERDAY DUE TO POST FRONTAL AIR MASS THROUGH MIDDAY...HOWEVER AS LEE TROUGH DEVELOPS LATE THIS AFTERNOON WE COULD ACTUALLY END UP PRETTY SIMILAR IF OPAQUE CIRRUS DOESNT COMPLICATE THINGS. WEDNESDAY SHOULD BE SUNNY AND WARMER WITH HIGHS IN THE 60S...POSSIBLE AROUND 70 IN OUR SOUTH. DEEP SW FLOW DEVELOPS ON BACK EDGE OF RIDGE THURSDAY A BUILDING TROUGH WILL RESULT IN DEEP SW FLOW ACROSS THE CENTRAL ROCKIES/PLAINS. MODELS CONTINUE TO SHOW VERY STRONG WAA WITH THIS PATTERN AS STRONGER LEE TROUGH DEVELOPS. THIS WILL RESULT IN HIGH TEMPERATURE RECORDS BEING MET AT A FEW LOCATIONS. A DRY COLD FRONT WILL MOVE THROUGH THE REGION WITH SHORTWAVE TROUGH PASSING JUST NORTH OF OUR CWA. DEEP DRY AIR MASS IN PLACE WILL PRECLUDE ANY PRECIP CHANCES. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 225 AM MST TUE FEB 16 2016 FOR THE EXTENDED PERIOD...DRY CONDITIONS ACROSS THE FORECAST AREA CONTINUE AS BROAD H5 RIDGE SEEN EARLIER IN THE WEEK BEGINS TO BREAKS DOWN/FLATTEN ALLOWING FOR ZONAL FLOW OVER THE PLAINS/ROCKIES REGION. A WEAK SHORTWAVE PASSES SOUTH OF THE REGION SUNDAY NIGHT INTO NEXT MONDAY...FOLLOWED BY A STRONGER SYSTEM COMING OFF THE ROCKIES MONDAY NIGHT ON INTO TUESDAY. SOME MODEL DIFFERENCES IN AVAILABLE QPF WITH ITS PASSAGE...BUT HAVE STAYED CLOSE TO GFS GIVING AREA A CHANCE FOR LIGHT RAIN BASED ON EXPECTED TEMPS DURING PASSAGE. THIS SYSTEM LOOKS TO HAVE POTENTIAL FOR STRONG GUSTY WINDS BEHIND IT AS IT TRAVERSES AREA. CURRENT MODEL GUIDANCE BRING 25-35 MPH POTENTIAL. FOR TEMPS...ABOVE NORMAL CONDITIONS EXPECTED WITH HIGHS REACHING INTO THE 60S FRIDAY/SATURDAY AHEAD OF THE AFOREMENTIONED TROUGHS...THEN 50S FOR SUNDAY THRU TUESDAY AS SLIGHTLY COOLER AIR IS DRAGGED INTO AREA WITH EACH SYSTEM PASSAGE. OVERNIGHT LOWS WILL DROP FROM THE 30S INTO THE 20S FOR THE SAME ABOVE MENTIONED REASON...ARRIVAL OF COOLER/COLDER AIR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 434 AM MST TUE FEB 16 2016 VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK TERMINAL. SEVERAL POCKETS OF 3000-3500KFT AGL CIG UPSTREAM MAY TRY TO ADVECT TOWARDS BOTH TERMINAL...HOWEVER CURRENT TRENDS IN SATELLITE AND SHORT RANGE GUIDANCE SHOW THESE POCKETS DISSIPATING OVER THE NEXT FEW HOURS AND REMAINING WELL OUTSIDE THE VICINITY OF EITHER TERMINAL. GUSTY NORTH-NORTHWEST WINDS THIS MORNING SHOULD DECREASE AS SURFACE HIGH PRESSURE MOVES SOUTH AND EAST ACROSS THE REGION. WINDS WILL EVENTUALLY VEER TO THE WEST BY LATE THIS EVENING/TONIGHT AS SURFACE LOW PRESSURE BEGINS TO REDEVELOP IN EASTERN COLORADO BEHIND THE EXITING HIGH PRESSURE. && .FIRE WEATHER... ISSUED AT 314 AM MST TUE FEB 16 2016 CONSIDERING THE VERY DRY AIR MASS ADVERTISED BY GUIDANCE WE COULD SEE NEAR CRITICAL CRITERIA RH MET IN OUR FAR SW WEDNESDAY AFTERNOON...BUT THIS SHOULDNT NECESSITATE A WATCH ISSUANCE CONSIDERING THE MARGINAL NATURE OF THE RH/WINDS. STRONG UNIDIRECTIONAL GRADIENT (STRONG WINDS)...GOOD MIXING...RECORD HIGH TEMPERATURES...AND VERY DRY AIR SHOULD MAKE CRITICAL CRITERIA CROSSOVER OF RH/WINDS A SLAM DUNK THURSDAY FOR SW PORTIONS OF OUR CWA (ROUGHLY SW OF YUMA TO GOVE LINE). AT THIS JUNCTURE THE BIGGEST QUESTION ON WHERE TO DRAW UP A FIRE WEATHER WATCH THURSDAY IS FUELS. OVER THE NEXT FEW DAYS FURTHER MELTING/CURING SHOULD TAKE PLACE. LOCATIONS FURTHER NORTH AND EAST MAY STILL BE WET ENOUGH FROM RECENT SNOW MELT THAT WITHOUT COLLABORATING WITH PARTNERS IM NOT COMFORTABLE ISSUING ANY HAZARD PRODUCTS FOR THOSE LOCATIONS. IM MORE CONFIDENT THAT LOCATIONS ALONG/SOUTH OF HWY 40 WILL HAVE AMPLE OPPORTUNITY TO CURE AND THE MAJORITY OF FUELS WILL BE READY TO GO. I DECIDED TO LIMIT A FIRE WEATHER WATCH TO THESE SOUTHERN AREAS DURING THIS UPDATE...AND WILL ALLOW COORDINATION WITH PARTNERS DURING DAY SHIFT TO FINE TUNE FUELS EXPECTATIONS NORTH OF THIS. && .CLIMATE... ISSUED AT 314 AM MST TUE FEB 16 2016 DAILY RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES THURSDAY. SITE.............RECORD...CURRENT FORECAST GOODLAND, KS.......74...........78 MCCOOK, NE.........82...........76 BURLINGTON,CO......74...........76 HILL CITY,KS.......75...........80 COLBY, KS..........81...........78 TRIBUNE, KS........79...........79 YUMA, CO...........73...........74 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR KSZ027>029-041-042. CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR COZ254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JN AVIATION...DR FIRE WEATHER...DR CLIMATE...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
314 AM MST TUE FEB 16 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM MST TUE FEB 16 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW NW FLOW STILL IN PLACE ACROSS THE PLAINS WITH A SHORTWAVE TROUGH CURRENTLY OVER CENTRAL NEBRASKA. AT THE SURFACE A COLD FRONT HAS PUSHED THROUGH OUR CWA WITH HIGH PRESSURE NOW BUILDING FROM THE NEBRASKA PANHANDLE INTO NE COLORADO AND NW KANSAS. THE MAIN CONCERN THIS FORECAST UPDATE WAS ON POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS MAINLY THURSDAY...SEE FIRE WEATHER DISCUSSION FOR DETAILS. EARLY THIS MORNING...RADAR CONTINUES TO SHOW LIGHT RETURNS ASSOCIATED WITH MID LEVEL FRONTOGENESIS...WITH VIRGA OR A FEW SPRINKLES. DRIER AND MUCH MORE STABLE AIR BEHIND EXITING SHORTWAVE TROUGH HAS HELPED WEAKEN THIS ACTIVITY AND SHORT RANGE GUIDANCE CONTINUES TO SHOW A DIMINISHING TREND THROUGH 12Z. TODAY-THURSDAY NIGHT...STRONG H5 RIDGE OVER THE WESTERN US COAST WILL SLIDE EASTWARD OVER THE CENTRAL ROCKIES AND PLAINS THROUGH MID WEEK. THIS WILL SUPPORT A VERY DEEP/DRY AIR MASS AND UNSEASONABLY WARM TEMPERATURES THROUGH THESE PERIODS. TEMPS MAY BE A LITTLE COOLER TODAY THAN YESTERDAY DUE TO POST FRONTAL AIR MASS THROUGH MIDDAY...HOWEVER AS LEE TROUGH DEVELOPS LATE THIS AFTERNOON WE COULD ACTUALLY END UP PRETTY SIMILAR IF OPAQUE CIRRUS DOESNT COMPLICATE THINGS. WEDNESDAY SHOULD BE SUNNY AND WARMER WITH HIGHS IN THE 60S...POSSIBLE AROUND 70 IN OUR SOUTH. DEEP SW FLOW DEVELOPS ON BACK EDGE OF RIDGE THURSDAY A BUILDING TROUGH WILL RESULT IN DEEP SW FLOW ACROSS THE CENTRAL ROCKIES/PLAINS. MODELS CONTINUE TO SHOW VERY STRONG WAA WITH THIS PATTERN AS STRONGER LEE TROUGH DEVELOPS. THIS WILL RESULT IN HIGH TEMPERATURE RECORDS BEING MET AT A FEW LOCATIONS. A DRY COLD FRONT WILL MOVE THROUGH THE REGION WITH SHORTWAVE TROUGH PASSING JUST NORTH OF OUR CWA. DEEP DRY AIR MASS IN PLACE WILL PRECLUDE ANY PRECIP CHANCES. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 225 AM MST TUE FEB 16 2016 FOR THE EXTENDED PERIOD...DRY CONDITIONS ACROSS THE FORECAST AREA CONTINUE AS BROAD H5 RIDGE SEEN EARLIER IN THE WEEK BEGINS TO BREAKS DOWN/FLATTEN ALLOWING FOR ZONAL FLOW OVER THE PLAINS/ROCKIES REGION. A WEAK SHORTWAVE PASSES SOUTH OF THE REGION SUNDAY NIGHT INTO NEXT MONDAY...FOLLOWED BY A STRONGER SYSTEM COMING OFF THE ROCKIES MONDAY NIGHT ON INTO TUESDAY. SOME MODEL DIFFERENCES IN AVAILABLE QPF WITH ITS PASSAGE...BUT HAVE STAYED CLOSE TO GFS GIVING AREA A CHANCE FOR LIGHT RAIN BASED ON EXPECTED TEMPS DURING PASSAGE. THIS SYSTEM LOOKS TO HAVE POTENTIAL FOR STRONG GUSTY WINDS BEHIND IT AS IT TRAVERSES AREA. CURRENT MODEL GUIDANCE BRING 25-35 MPH POTENTIAL. FOR TEMPS...ABOVE NORMAL CONDITIONS EXPECTED WITH HIGHS REACHING INTO THE 60S FRIDAY/SATURDAY AHEAD OF THE AFOREMENTIONED TROUGHS...THEN 50S FOR SUNDAY THRU TUESDAY AS SLIGHTLY COOLER AIR IS DRAGGED INTO AREA WITH EACH SYSTEM PASSAGE. OVERNIGHT LOWS WILL DROP FROM THE 30S INTO THE 20S FOR THE SAME ABOVE MENTIONED REASON...ARRIVAL OF COOLER/COLDER AIR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1033 PM MST MON FEB 15 2016 AT THIS TIME VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. FOR KGLD...NARROW BAND OF LIGHT PRECIPITATION THAT CURRENTLY TO THE NORTH THROUGH EAST OF KGLD APPEARS TO BE DECREASING IN COVERAGE AND INTENSITY WITH SOME LIGHT PRECIPITATION STILL UPSTREAM. IT DOES NOT LOOK LIKE THIS PRECIPITATION WILL AFFECT THE SITE SO JUST PUT IN VCSH FOR THE FIRST COUPLE OF HOURS. A MINORITY OF THE GUIDANCE IS INDICATING SUB VFR CONDITIONS. THERE IS MVFR CONDITIONS WELL UPSTREAM OF THE AREA AT THIS TIME. CHOSE TO NOT GO MVFR BUT JUST ABOVE MVFR AND LET THE OVERNIGHT SHIFT ADJUST. OTHERWISE NORTHWEST WINDS NEAR 15 KNOTS WITH GUSTS NEAR 24 KNOTS ARE EXPECTED UNTIL 14Z. AFTER THAT THE WINDS BE SHIFTING THROUGH THE AFTERNOON AS THEY STAY BELOW 10 KNOTS. FOR KMCK...PRECIPITATION SHOULD STAY WEST THROUGH SOUTH OF THE SITE. AGAIN AM NOT BUYING INTO THE MVFR CEILINGS THAT SOME GUIDANCE IS SHOWING AND AGAIN WENT JUST ABOVE MVFR FROM O9Z TO 14Z. LLWS WILL BE IN PLACE UNTIL 09Z. AT THAT TIME THE NORTHWEST WINDS WILL INCREASE WITH SUSTAINED WINDS NEAR 17 KNOTS AND GUSTS TO NEAR 25 KNOTS. THIS WILL CONTINUE UNTIL 14Z WHEN THE WINDS WILL STAY BELOW 12 KNOTS AS THEY SHIFT THROUGH THE AFTERNOON. && .FIRE WEATHER... ISSUED AT 314 AM MST TUE FEB 16 2016 CONSIDERING THE VERY DRY AIR MASS ADVERTISED BY GUIDANCE WE COULD SEE NEAR CRITICAL CRITERIA RH MET IN OUR FAR SW WEDNESDAY AFTERNOON...BUT THIS SHOULDNT NECESSITATE A WATCH ISSUANCE CONSIDERING THE MARGINAL NATURE OF THE RH/WINDS. STRONG UNIDIRECTIONAL GRADIENT (STRONG WINDS)...GOOD MIXING...RECORD HIGH TEMPERATURES...AND VERY DRY AIR SHOULD MAKE CRITICAL CRITERIA CROSSOVER OF RH/WINDS A SLAM DUNK THURSDAY FOR SW PORTIONS OF OUR CWA (ROUGHLY SW OF YUMA TO GOVE LINE). AT THIS JUNCTURE THE BIGGEST QUESTION ON WHERE TO DRAW UP A FIRE WEATHER WATCH THURSDAY IS FUELS. OVER THE NEXT FEW DAYS FURTHER MELTING/CURING SHOULD TAKE PLACE. LOCATIONS FURTHER NORTH AND EAST MAY STILL BE WET ENOUGH FROM RECENT SNOW MELT THAT WITHOUT COLLABORATING WITH PARTNERS IM NOT COMFORTABLE ISSUING ANY HAZARD PRODUCTS FOR THOSE LOCATIONS. IM MORE CONFIDENT THAT LOCATIONS ALONG/SOUTH OF HWY 40 WILL HAVE AMPLE OPPORTUNITY TO CURE AND THE MAJORITY OF FUELS WILL BE READY TO GO. I DECIDED TO LIMIT A FIRE WEATHER WATCH TO THESE SOUTHERN AREAS DURING THIS UPDATE...AND WILL ALLOW COORDINATION WITH PARTNERS DURING DAY SHIFT TO FINE TUNE FUELS EXPECTATIONS NORTH OF THIS. && .CLIMATE... ISSUED AT 314 AM MST TUE FEB 16 2016 DAILY RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES THURSDAY. SITE.............RECORD...CURRENT FORECAST GOODLAND, KS.......74...........78 MCCOOK, NE.........82...........76 BURLINGTON,CO......74...........76 HILL CITY,KS.......75...........80 COLBY, KS..........81...........78 TRIBUNE, KS........79...........79 YUMA, CO...........73...........74 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR KSZ027>029-041-042. CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR COZ254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JN AVIATION...BULLER FIRE WEATHER...DR CLIMATE...DR
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1144 PM CST MON FEB 15 2016 ...Updated aviation discussion... .UPDATE... ISSUED AT 853 PM CST MON FEB 15 2016 Radar trends showing that there are some showers across C Kansas in association with a passing shortwave trough. Threw in some 20 pops in the NE zones as this activity could measure a couple of hundredths. The HRRR is picking up on this activity as well. && .SHORT TERM...(THIS EVENING THROUGH Tuesday) ISSUED AT 211 PM CST MON FEB 15 2016 A shortwave trough embedded in northwest flow will drag a weak cold front through western Kansas later tonight. West winds at 10 kts ahead of the front and 15 kt northwest winds behind the front after 09 UTC will prevent temperatures from falling a lot. Lows should be in the mid to upper 30s in far western Kansas, with some lower 40s in south central Kansas. Weak surface high pressure is expected to settle across western Kansas on Tuesday. With mostly sunny skies, temperatures ought to reach into the 50s, with perhaps some lower 60s in far southwestern Kansas. .LONG TERM...(Tuesday NIGHT THROUGH Monday) ISSUED AT 211 PM CST MON FEB 15 2016 A surface trough will develop in the lee of the Rockies by Wednesday as the mid level flow increases across the Rockies in advance of a shortwave trough. Temperatures should warm well into the 60s, with some lower 70s possible at Liberal and Elkhart. On Thursday, as the strong shortwave trough approaches, downslope southwest winds will develop, allowing temperatures to rise into the lower to middle 80s. Winds will be from the southwest at 20-25 mph, and with relative humidity as low as 10 percent, fire danger will be high. A cold front will pass through western Kansas by Thursday night, with highs falling back into the 60s for Friday, before rebounding back into the upper 60s to near 70 degrees by Saturday. Another cold front will pass across western Kansas by Saturday night as an upper level trough moves southeastward into the upper Midwest. Therefore, highs may drop back into the 50s to lower 60s for Sunday. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Tuesday NIGHT) ISSUED AT 1143 PM CST MON FEB 15 2016 Scattered light showers, mostly just sprinkles, will impact the Hays terminal for a few hours at the beginning of the period. Ceilings and visibilities will be VFR at all the terminals. A weak cold front will push through western and central Kansas early this morning. Winds will become gusty behind the front and should continue through midday before becoming light and variable during the afternoon. && .PRELIMINARY POINT TEMPS/POPS... DDC 39 59 33 68 / 0 0 0 0 GCK 37 60 32 69 / 0 0 0 0 EHA 37 63 32 72 / 0 0 0 0 LBL 38 61 33 72 / 0 0 0 0 HYS 37 56 33 63 / 20 0 0 0 P28 42 59 34 70 / 10 0 0 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ UPDATE...Sugden SHORT TERM...Finch LONG TERM...Finch AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
ISSUED BY NATIONAL WEATHER SERVICE GAYLORD MI 1222 PM EST TUE FEB 16 2016 .UPDATE... ISSUED AT 1124 AM EST TUE FEB 16 2016 13Z SURFACE/COMPOSITE ANALYSIS SHOWS A COLD FRONT ACROSS WESTERN LAKE SUPERIOR/FAR NORTHWEST WISCONSIN/CENTRAL MINNESOTA...WITH A 1005MB FRONTAL WAVE NORTH OF LAKE SUPERIOR. WATER VAPOR IMAGERY SHOWS A PAIR OF SHORT WAVE TROUGHS ROTATING IN THE VICINITY OF UPPER MICHIGAN... ONE TRACKING INTO NORTHERN LAKE MICHIGAN WITH SOME LIGHT SNOW AROUND THE NORTHERN/DEFORMATION SIDE OF THIS VORTICITY CENTER INTO EASTERN/ SOUTHERN UPPER MICHIGAN...ANOTHER DIGGING SOUTHEAST FROM NORTHWEST ONTARIO WITH A LITTLE LIGHT SNOW OUT AHEAD OF THAT. LOW LEVEL COLD ADVECTION SPREADING ACROSS THE WESTERN HALF OF LAKE SUPERIOR EXPECTED TO INCREASE LAKE CONVECTION AS THE AFTERNOON PROGRESSES INTO FAR WESTERN PORTIONS OF THE FORECAST AREA. ONLY MINOR FORECAST ADJUSTMENTS MADE FOR THE AFTERNOON HOURS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 413 AM EST TUE FEB 16 2016 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW SOME UPR TROFFING CENTERED NEAR HUDSON BAY DOMINATING CENTRAL AND ERN NAMERICA. THERE IS AN APRCHG SHRTWV OVER NRN MN THAT IS EMBEDDED IN THE WNW FLOW ALF. AXIS OF MODEST DEEP LYR QVECTOR CNVGC AHEAD OF THIS FEATURE CAUSING 12HR H5 HGT FALLS UNDER 30M AS WELL AS SOME MODEST MSTR SHOWN ON THE WV IMAGERY/HINTED AT BY THE 00Z MPX RAOB IS RESULTING IN SOME SCT SN SHOWERS OVER THE W AND CENTRAL CWA EARLY THIS MRNG WELL TO THE E OF ACCOMPANYING SFC LO PRES TROF MOVING THRU NE MN. SHARP SUBSIDENCE INVRN NEAR H85 DEPICTED ON THE 00Z GRB RAOB IS KEEPING THE FAR ERN CWA DRY...BUT THERE IS A GOOD DEAL OF LO CLD TRAPPED BENEATH THIS INVRN. H85 TEMPS RIGHT ALONG THIS LO PRES TROF ARE NOT THAT COLD...AS 00Z H85 TEMP AT INL WAS ONLY -7C. FARTHER TO THE NNW...THE 00Z H85 TEMPS WERE -13C AT YPL AND -16C AT THE PAS MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS TODAY ASSOCIATED WITH APRCHG SHRTWV/LO PRES TROF AND THEN ON LES COVERAGE/INTENSITY TNGT AS COLDER AIR FOLLOWS IN THE NNW FLOW BEHIND THE TROF PASSAGE. TODAY...AS SHRTWV/AXIS OF ACCOMPANYING DEEP LYR FORCING AND DEEPER MSTR MOVE E TODAY...EXPECT THE SCT SN SHOWERS TO OVERSPREAD THE ENTIRE CWA THIS MORNING. BUT ALL THE SHORT TERM GUIDANCE HINTS THE MARGINAL FORCING/MSTR WL RESTRICT PCPN TOTALS WITH NO MORE THAN ABOUT AN INCH OF SN AT ANY ONE SPOT. BUT AS COLDER AIR MOVES IN TO THE NW CWA LATER IN THE DAY...LOWERING H85 TEMPS DOWN TO ABOUT -15C/- 16C OVER THE KEWEENAW BY 00Z WED...SOME MORE NMRS/HEAVER LK EFFECT SN SHOWERS MAY DVLP IN THAT AREA. SINCE SGNFTLY COLDER AIR WL NOT ARRIVE UNTIL LATER...GOING FCST HI TEMPS MAINLY IN THE 30S SEEMS ON TRACK. TNGT...LLVL NNW FLOW AHEAD OF APRCHG CNDN HI PRES THAT IS FCST TO REACH NEAR THUNDER BAY ONTARIO BY DAYBREAK WED WL DRIVE H85 TEMPS AS LO AS -18C TO -20C OVER THE E HALF LK SUP AT 12Z. THIS INFLUX OF COLD AIR WL SUPPORT LES IN THE FAVORED SN BELTS IN GOGEBIC/ONTONAGON COUNTIES AND FM MARQUETTE TO THE E. WHILE FCST SHARPER LLVL SFC CNVGC IN THESE AREAS AS WELL AS FAVORABLE LOCATION OF THE DGZ/LLVL UVV MAX WITHIN THE MOIST LYR ARE FAVORABLE FOR SOME HEAVIER LES... ARRIVAL OF DEEP LYR QVECTOR DVGC/MID LVL DRYING THAT ARE FCST TO LOWER THE INVRN BASE TO 3-4K FT AGL/MORE ACYC H925 FLOW BY 12Z WED WL ACT TO LIMIT LES INTENSITY. THERE COULD BE SOME PATCHY BLSN NEAR LK SUP MAINLY IN THE EVNG WHEN H925 WINDS ARE FCST UP TO 25 KTS DURING PERIOD OF SHAPER LLVL CAA THAT WL ENHANCE MIXING OF THIS MOMENTUM TO THE SFC. ALTHOUGH THERE COULD BE SEVERAL INCHES OF FLUFFY SN IN THE FAVORED SN BELTS...OVERALL LARGER SCALE NEGATIVES AND MARGINAL WINDS/BLSN POTENTIAL INDICATE THIS LES EVENT WL NOT REQUIRE A HEADLINE. MIN TEMPS TNGT WL FALL TO 5-10F OVER THE INTERIOR W HALF BUT SHOULD HOLD NO LOWER THAN THE MID TEENS IN THE FAVORED SN BELTS E OF MARQUETTE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 413 AM EST TUE FEB 16 2016 ...WINTRY MIX THU NIGHT INTO FRI... STRONG JET DIGGING INTO CNTRL CONUS RESULTS IN UPPER TROUGHING AND COLD AIR ACROSS GREAT LAKES ON WED. THEN...ENERGETIC PACIFIC JET OF 175-200KT AT H25...FORCES TROUGH CURRENTLY OVER EASTERN PACIFIC OVER WESTERN CONUS THU WITH DOWNSTREAM RIDGING SPREADING OVER GOOD PORTION OF CONUS...INCLUDING GREAT LAKES. WESTERN TROUGH HEADS TOWARD GREAT LAKES ON FRI ALONG WITH DEEPENING SFC LOW AND WARM FRONT. MODELS ARE GOING BACK AND FORTH ON HOW FAR NORTH PRIMARY SFC LOW TRACKS THU NIGHT THROUGH FRI NIGHT WHICH AFFECTS HOW QUICKLY WARM AIR ADVECTION AND MIXED PRECIP ISSUES ARRIVE OVER THE UPPER GREAT LAKES. IN WAKE OF THE SFC LOW...COOLER AIR MOVES BACK OVER UPPER GREAT LAKES NEXT WEEKEND...BUT EXTENT OF COOLING REMAINS UNCERTAIN. SWIFT WNW FLOW ALOFT COULD BRING ANOTHER DISTURBANCE AND SNOW CHANCES...MAINLY LATER IN THE WEEKEND. STARTING OFF ON WED...TROUGHING AND COLD AIR WILL BE TEMPORARILY IN PLACE. LOOKING AT H85 TEMPS -18C TO -20C...LOWEST OVER EASTERN LK SUPERIOR AND NORTHERN ONTARIO...BUT MODERATION OCCURS FAIRLY QUICKLY BY WED EVENING WITH RISING HEIGHTS ALOFT. TROUGH AXIS STAYING NORTHEAST OF UPPER GREAT LAKES LEADS TO LARGE SCALE SUBSIDENCE TAKING CHARGE BY WED MORNING WITH STRONG H7-H5 Q-VECTOR DIVERGENCE AND DRYING ABOVE H85. SFC HIGH OVER 1025MB SLIDING IN FM MANITOBA AND NORTHERN ONTARIO BRINGS ANTICYCLONIC SFC FLOW ACROSS LK SUPERIOR THOUGH NEUTRAL TO WEAKLY CYCLONIC FLOW MAY HANG AROUND FOR MORNING HOURS OVER EASTERN LK SUPERIOR AND DOWNSTREAM NCNTRL AND EASTERN CWA. AS THE HIGH BUILDS IN...THE INVERSION HEIGHTS FALL TO LESS THAN 4KFT OVER LK SUPERIOR. LAKE EQUILIBRIUM LEVELS SIMILAR OVER WEST BUT ARE MORE AROUND 6KFT OVER SCNTRL LK SUPERIOR DUE TO INCREASED FETCH WITH NNW TO N BLYR FLOW. DEEPER LAKE CONVECTIVE LAYER...BLYR WINDS 15-20 KTS HELPING ORGANIZATION...AND FAVORABLE DGZ MAY OFFSET THE NEGATIVE LARGE SCALE FACTORS TO HELP FLUFF UP A COUPLE INCHES OF SNOW ON WED MORNING. EXPECTED BLYR FLOW FAVORS SNOW BELTS OVER EASTERN MARQUETTE COUNTY INTO ALGER COUNTY AND MAYBE EVEN INTO DELTA AND SCHOOLCRAFT COUNTIES FOR PERSISTENT SNOW SHOWERS AND ACCUMS. SUBSIDENCE AND DRYING WITH THE HIGH EVENTUALLY WILL PUT CRIMP ON LES LATE WED MORNING INTO WED AFTN...THOUGH ONSHORE FLOW AND ENOUGH MOISTURE IN LOW-LEVELS WILL KEEP CLOUDS AND FLURRIES OVER PARTS OF CNTRL CWA UNTIL LATE AFTN. AWAY FM LAKE EFFECT...SCT STRATOCU MAY EXPAND WITH HEATING OF THE DAY...BUT WOULD ONLY BE FLURRIES INLAND DUE TO VERY LOW INVERSIONS AND NO SUPPORT IN LARGER SCALE. TEMPS IN THE TEENS MOST AREAS...BUT THAT IS AS COLD AS MAX TEMPS WILL BE THE REST OF THE WEEK. SFC RIDGE CENTERS OVER EAST HALF OF CWA WED EVENING THEN DRIFTS TO LOWER GREAT LAKES BY THU MORNING. BEST CHANCE OF CLEARING AND LIGHT WINDS WITH THE RIDGE WILL BE OVER EAST HALF IN THE EVENING. RISK OF LOW CLOUDS STAYING TRAPPED BENEATH INVERSION OVER WEST HALF. NAM IS MOST AGGRESSIVE ON THAT IDEA AND SOMETIMES HAS BIAS TO SO SUCH A SCENARIO. IN ANY CASE...RETURN FLOW AND/OR CLOUDS SHOULD KEEP TEMPS FM TANKING WEST...BUT THAT MIGHT NOT BE THE CASE OVER THE EAST. WILL KEEP FAVORING COLDER GUIDANCE THERE. RIDGE HEADS TOWARD NEW ENGLAND AND MID ATLANTIC ON THU WHILE BROAD AND RATHER COMPLEX AREA OF DEEP LOW PRESSURE SHIFTS FROM THE PACIFIC NORTHWEST AND BRITISH COLUMBIA ACROSS THE ROCKIES TOWARD THE NORTHERN PLAINS. SOUNDINGS INDICATE MID-HIGH CLOUDS LATER IN THE DAY BUT LOW-LEVELS STAY DRY. EXCEPTION IS OVER INTERIOR WEST HALF WHERE UPSLOPE SSE WINDS BTWN THE DEPARTING RIDGE AND APPROACHING LOW MAY HELP DEVELOP LOW CLOUDS/FLURRIES/FZDZ. WARM/MOIST ADVECTION ALOFT RAMPS UP THU NIGHT INTO FRI. SCENARIO NOT COMPLETELY CLEAR CUT THOUGH DUE TO DRYING ALOFT THAT IS SHOWN BY ECMWF...WHICH IS WPC FAVORED MODEL ATTM WITH THIS SYSTEM AND ALSO HAS BEEN MOST CONSISTENT WITH TRACK OF SFC LOW. WOULD SEE SOME SORT OF SNOW TO DZ/FZDZ TRANSITION IF DRYING ALOFT OCCURRED AND EVEN THE DZ/FZDZ RISK LATER THU NIGHT COULD BE AN IFFY PROPOSITION DUE TO LOW-LEVEL DRYING IN DRY SLOT OF APPROACHING SFC LOW. AREA OF CNTRL UPR MICHIGAN WITH SSE WINDS PROVIDING UPSLOPE AND MOISTURE OFF LK MICHIGAN MAY BE THE EXCEPTION. FOR NOW...SHOWED HIGHER/LIKELY POPS THU EVENING THEN TAPERED TO CHANCE POPS OVERNIGHT. THOUGH PTYPE WOULD BE MORE DZ/FZDZ KEPT WITH RAIN/FZRA. DID NOT WANT TO GET TOO SPECIFIC AS TIMING OUT A DRY SLOT AND ITS AFFECT ON PTYPE IS KIND OF RISKY 3 DAYS OUT. CONCERNED THAT COLD SFC TEMPS AND ROAD TEMPS MAY RESULT IN FZRA/ICING AT LEAST ON UNTREATED ROADS LATE THU NIGHT INTO FRI MORNING EVEN IF AIR TEMPS ARE SLIGHTLY ABOVE FREEZING. WILL BE SOMETHING TO KEEP IN MIND ON LATER SHIFTS. DEEP MOISTURE WOULD THEN FILL BACK IN ON FRIDAY MORNING WITH ARRIVAL OF SHORTWAVE TROUGH/FAVORABLE DYNAMICS. BY TIME THE DEEPER MOISTURE RETURNS ON FRI...PTYPE WOULD BE LIQUID WITH SOUNDINGS SHOWING DEEP/MOIST WELL ABOVE FREEZING LAYER THROUGH 5KFT/H8. DID KEEP MENTION OF FZRA 12Z-15Z WHERE TEMPS WERE 35 DEGREES OR LOWER. EVENTUALLY COLDER AIR WORKS IN BUT IT IS NOT AS EMPHATIC AS IT LOOKED LIKE A COUPLE NIGHTS AGO. THUS...PTYPE FRI NIGHT AND/OR SAT COULD STILL HAVE SOME RAIN/SNOW. DOES BECOME SUFFICIENTLY COLD ENOUGH SAT NIGHT INTO SUN FOR JUST SNOW. 00Z MODELS SHOW SHORTWAVE CROSSING SO HAVE POTENTIAL FOR AT LEAST WIDESPREAD LIGHT SNOW ON SUN WITH SMALL CHANCE OF LES SUN NIGHT INTO MON BEHIND THAT SYSTEM. TWEAKED TEMPS DOWN SLIGHTLY FM CONSENSUS FOR MON AS 00Z ECMWF/GFS TRENDED COLDER THAN 12Z/15 SOLNS. ECMWF SHOWS -20C H85 TEMPS RETURNING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 1222 PM EST TUE FEB 16 2016 LAKE INDUCED SNOW SHOWERS TO BECOME MORE COMMON THIS AFTERNOON AND WILL PERSIST THROUGH TONIGHT WITH PREVAILING IFR VISIBILITIES EXPECTED. SNOW SHOWER INTENSITY LIKELY TO DIMINISH TOWARD DAYBREAK WEDNESDAY THOUGH MVFR CEILINGS STILL EXPECTED THROUGH WEDNESDAY MORNING && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 413 AM EST TUE FEB 16 2016 EXPECT LIGHT WSW WINDS THIS MORNING TO SHIFT TO THE NNW DURING THE DAY FOLLOWING A COLD FRONTAL PASSAGE AND INCREASE UP TO 30 KTS INTO THE EARLY MORNING HOURS ON WED UNDER A TIGHTENING PRES GRADIENT AHEAD OF HI PRES BUILDING INTO FAR NW ONTARIO ON WED MORNING. THERE MAY BE POCKETS OF HEAVY FREEZING SPRAY OVER PORTIONS OF THE NCENTRAL LAKE TONIGHT WITH THE INFLUX OF ARCTIC AIR. WINDS WILL DIMINISH TO UNDER 20KT WED AS HI PRES ARRIVES OVER THE UPPER LAKES. STRONGER SSE WINDS UP TO 30KT WILL THEN DEVELOP ON THU UNDER A TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING HI AND ANOTHER APPROACHING LO PRES. OVER THE E HALF OF THE LAKE...S GALES TO 35 KTS ARE LIKELY AT LEAST PART OF THE TIME ON THU AFTERNOON AND NIGHT. THE LO WILL PASS OVER OR JUST N OF LAKE SUPERIOR FRI. STRONG W TO NW WINDS UP TO 30KT WILL THEN FOLLOW INTO FRI NIGHT AND SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JPB SHORT TERM...KC LONG TERM...JLA AVIATION...JPB MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
643 AM EST TUE FEB 16 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 413 AM EST TUE FEB 16 2016 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW SOME UPR TROFFING CENTERED NEAR HUDSON BAY DOMINATING CENTRAL AND ERN NAMERICA. THERE IS AN APRCHG SHRTWV OVER NRN MN THAT IS EMBEDDED IN THE WNW FLOW ALF. AXIS OF MODEST DEEP LYR QVECTOR CNVGC AHEAD OF THIS FEATURE CAUSING 12HR H5 HGT FALLS UNDER 30M AS WELL AS SOME MODEST MSTR SHOWN ON THE WV IMAGERY/HINTED AT BY THE 00Z MPX RAOB IS RESULTING IN SOME SCT SN SHOWERS OVER THE W AND CENTRAL CWA EARLY THIS MRNG WELL TO THE E OF ACCOMPANYING SFC LO PRES TROF MOVING THRU NE MN. SHARP SUBSIDENCE INVRN NEAR H85 DEPICTED ON THE 00Z GRB RAOB IS KEEPING THE FAR ERN CWA DRY...BUT THERE IS A GOOD DEAL OF LO CLD TRAPPED BENEATH THIS INVRN. H85 TEMPS RIGHT ALONG THIS LO PRES TROF ARE NOT THAT COLD...AS 00Z H85 TEMP AT INL WAS ONLY -7C. FARTHER TO THE NNW...THE 00Z H85 TEMPS WERE -13C AT YPL AND -16C AT THE PAS MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS TODAY ASSOCIATED WITH APRCHG SHRTWV/LO PRES TROF AND THEN ON LES COVERAGE/INTENSITY TNGT AS COLDER AIR FOLLOWS IN THE NNW FLOW BEHIND THE TROF PASSAGE. TODAY...AS SHRTWV/AXIS OF ACCOMPANYING DEEP LYR FORCING AND DEEPER MSTR MOVE E TODAY...EXPECT THE SCT SN SHOWERS TO OVERSPREAD THE ENTIRE CWA THIS MORNING. BUT ALL THE SHORT TERM GUIDANCE HINTS THE MARGINAL FORCING/MSTR WL RESTRICT PCPN TOTALS WITH NO MORE THAN ABOUT AN INCH OF SN AT ANY ONE SPOT. BUT AS COLDER AIR MOVES IN TO THE NW CWA LATER IN THE DAY...LOWERING H85 TEMPS DOWN TO ABOUT -15C/- 16C OVER THE KEWEENAW BY 00Z WED...SOME MORE NMRS/HEAVER LK EFFECT SN SHOWERS MAY DVLP IN THAT AREA. SINCE SGNFTLY COLDER AIR WL NOT ARRIVE UNTIL LATER...GOING FCST HI TEMPS MAINLY IN THE 30S SEEMS ON TRACK. TNGT...LLVL NNW FLOW AHEAD OF APRCHG CNDN HI PRES THAT IS FCST TO REACH NEAR THUNDER BAY ONTARIO BY DAYBREAK WED WL DRIVE H85 TEMPS AS LO AS -18C TO -20C OVER THE E HALF LK SUP AT 12Z. THIS INFLUX OF COLD AIR WL SUPPORT LES IN THE FAVORED SN BELTS IN GOGEBIC/ONTONAGON COUNTIES AND FM MARQUETTE TO THE E. WHILE FCST SHARPER LLVL SFC CNVGC IN THESE AREAS AS WELL AS FAVORABLE LOCATION OF THE DGZ/LLVL UVV MAX WITHIN THE MOIST LYR ARE FAVORABLE FOR SOME HEAVIER LES... ARRIVAL OF DEEP LYR QVECTOR DVGC/MID LVL DRYING THAT ARE FCST TO LOWER THE INVRN BASE TO 3-4K FT AGL/MORE ACYC H925 FLOW BY 12Z WED WL ACT TO LIMIT LES INTENSITY. THERE COULD BE SOME PATCHY BLSN NEAR LK SUP MAINLY IN THE EVNG WHEN H925 WINDS ARE FCST UP TO 25 KTS DURING PERIOD OF SHAPER LLVL CAA THAT WL ENHANCE MIXING OF THIS MOMENTUM TO THE SFC. ALTHOUGH THERE COULD BE SEVERAL INCHES OF FLUFFY SN IN THE FAVORED SN BELTS...OVERALL LARGER SCALE NEGATIVES AND MARGINAL WINDS/BLSN POTENTIAL INDICATE THIS LES EVENT WL NOT REQUIRE A HEADLINE. MIN TEMPS TNGT WL FALL TO 5-10F OVER THE INTERIOR W HALF BUT SHOULD HOLD NO LOWER THAN THE MID TEENS IN THE FAVORED SN BELTS E OF MARQUETTE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 413 AM EST TUE FEB 16 2016 ...WINTRY MIX THU NIGHT INTO FRI... STRONG JET DIGGING INTO CNTRL CONUS RESULTS IN UPPER TROUGHING AND COLD AIR ACROSS GREAT LAKES ON WED. THEN...ENERGETIC PACIFIC JET OF 175-200KT AT H25...FORCES TROUGH CURRENTLY OVER EASTERN PACIFIC OVER WESTERN CONUS THU WITH DOWNSTREAM RIDGING SPREADING OVER GOOD PORTION OF CONUS...INCLUDING GREAT LAKES. WESTERN TROUGH HEADS TOWARD GREAT LAKES ON FRI ALONG WITH DEEPENING SFC LOW AND WARM FRONT. MODELS ARE GOING BACK AND FORTH ON HOW FAR NORTH PRIMARY SFC LOW TRACKS THU NIGHT THROUGH FRI NIGHT WHICH AFFECTS HOW QUICKLY WARM AIR ADVECTION AND MIXED PRECIP ISSUES ARRIVE OVER THE UPPER GREAT LAKES. IN WAKE OF THE SFC LOW...COOLER AIR MOVES BACK OVER UPPER GREAT LAKES NEXT WEEKEND...BUT EXTENT OF COOLING REMAINS UNCERTAIN. SWIFT WNW FLOW ALOFT COULD BRING ANOTHER DISTURBANCE AND SNOW CHANCES...MAINLY LATER IN THE WEEKEND. STARTING OFF ON WED...TROUGHING AND COLD AIR WILL BE TEMPORARILY IN PLACE. LOOKING AT H85 TEMPS -18C TO -20C...LOWEST OVER EASTERN LK SUPERIOR AND NORTHERN ONTARIO...BUT MODERATION OCCURS FAIRLY QUICKLY BY WED EVENING WITH RISING HEIGHTS ALOFT. TROUGH AXIS STAYING NORTHEAST OF UPPER GREAT LAKES LEADS TO LARGE SCALE SUBSIDENCE TAKING CHARGE BY WED MORNING WITH STRONG H7-H5 Q-VECTOR DIVERGENCE AND DRYING ABOVE H85. SFC HIGH OVER 1025MB SLIDING IN FM MANITOBA AND NORTHERN ONTARIO BRINGS ANTICYCLONIC SFC FLOW ACROSS LK SUPERIOR THOUGH NEUTRAL TO WEAKLY CYCLONIC FLOW MAY HANG AROUND FOR MORNING HOURS OVER EASTERN LK SUPERIOR AND DOWNSTREAM NCNTRL AND EASTERN CWA. AS THE HIGH BUILDS IN...THE INVERSION HEIGHTS FALL TO LESS THAN 4KFT OVER LK SUPERIOR. LAKE EQUILIBRIUM LEVELS SIMILAR OVER WEST BUT ARE MORE AROUND 6KFT OVER SCNTRL LK SUPERIOR DUE TO INCREASED FETCH WITH NNW TO N BLYR FLOW. DEEPER LAKE CONVECTIVE LAYER...BLYR WINDS 15-20 KTS HELPING ORGANIZATION...AND FAVORABLE DGZ MAY OFFSET THE NEGATIVE LARGE SCALE FACTORS TO HELP FLUFF UP A COUPLE INCHES OF SNOW ON WED MORNING. EXPECTED BLYR FLOW FAVORS SNOW BELTS OVER EASTERN MARQUETTE COUNTY INTO ALGER COUNTY AND MAYBE EVEN INTO DELTA AND SCHOOLCRAFT COUNTIES FOR PERSISTENT SNOW SHOWERS AND ACCUMS. SUBSIDENCE AND DRYING WITH THE HIGH EVENTUALLY WILL PUT CRIMP ON LES LATE WED MORNING INTO WED AFTN...THOUGH ONSHORE FLOW AND ENOUGH MOISTURE IN LOW-LEVELS WILL KEEP CLOUDS AND FLURRIES OVER PARTS OF CNTRL CWA UNTIL LATE AFTN. AWAY FM LAKE EFFECT...SCT STRATOCU MAY EXPAND WITH HEATING OF THE DAY...BUT WOULD ONLY BE FLURRIES INLAND DUE TO VERY LOW INVERSIONS AND NO SUPPORT IN LARGER SCALE. TEMPS IN THE TEENS MOST AREAS...BUT THAT IS AS COLD AS MAX TEMPS WILL BE THE REST OF THE WEEK. SFC RIDGE CENTERS OVER EAST HALF OF CWA WED EVENING THEN DRIFTS TO LOWER GREAT LAKES BY THU MORNING. BEST CHANCE OF CLEARING AND LIGHT WINDS WITH THE RIDGE WILL BE OVER EAST HALF IN THE EVENING. RISK OF LOW CLOUDS STAYING TRAPPED BENEATH INVERSION OVER WEST HALF. NAM IS MOST AGGRESSIVE ON THAT IDEA AND SOMETIMES HAS BIAS TO SO SUCH A SCENARIO. IN ANY CASE...RETURN FLOW AND/OR CLOUDS SHOULD KEEP TEMPS FM TANKING WEST...BUT THAT MIGHT NOT BE THE CASE OVER THE EAST. WILL KEEP FAVORING COLDER GUIDANCE THERE. RIDGE HEADS TOWARD NEW ENGLAND AND MID ATLANTIC ON THU WHILE BROAD AND RATHER COMPLEX AREA OF DEEP LOW PRESSURE SHIFTS FROM THE PACIFIC NORTHWEST AND BRITISH COLUMBIA ACROSS THE ROCKIES TOWARD THE NORTHERN PLAINS. SOUNDINGS INDICATE MID-HIGH CLOUDS LATER IN THE DAY BUT LOW-LEVELS STAY DRY. EXCEPTION IS OVER INTERIOR WEST HALF WHERE UPSLOPE SSE WINDS BTWN THE DEPARTING RIDGE AND APPROACHING LOW MAY HELP DEVELOP LOW CLOUDS/FLURRIES/FZDZ. WARM/MOIST ADVECTION ALOFT RAMPS UP THU NIGHT INTO FRI. SCENARIO NOT COMPLETELY CLEAR CUT THOUGH DUE TO DRYING ALOFT THAT IS SHOWN BY ECMWF...WHICH IS WPC FAVORED MODEL ATTM WITH THIS SYSTEM AND ALSO HAS BEEN MOST CONSISTENT WITH TRACK OF SFC LOW. WOULD SEE SOME SORT OF SNOW TO DZ/FZDZ TRANSITION IF DRYING ALOFT OCCURRED AND EVEN THE DZ/FZDZ RISK LATER THU NIGHT COULD BE AN IFFY PROPOSITION DUE TO LOW-LEVEL DRYING IN DRY SLOT OF APPROACHING SFC LOW. AREA OF CNTRL UPR MICHIGAN WITH SSE WINDS PROVIDING UPSLOPE AND MOISTURE OFF LK MICHIGAN MAY BE THE EXCEPTION. FOR NOW...SHOWED HIGHER/LIKELY POPS THU EVENING THEN TAPERED TO CHANCE POPS OVERNIGHT. THOUGH PTYPE WOULD BE MORE DZ/FZDZ KEPT WITH RAIN/FZRA. DID NOT WANT TO GET TOO SPECIFIC AS TIMING OUT A DRY SLOT AND ITS AFFECT ON PTYPE IS KIND OF RISKY 3 DAYS OUT. CONCERNED THAT COLD SFC TEMPS AND ROAD TEMPS MAY RESULT IN FZRA/ICING AT LEAST ON UNTREATED ROADS LATE THU NIGHT INTO FRI MORNING EVEN IF AIR TEMPS ARE SLIGHTLY ABOVE FREEZING. WILL BE SOMETHING TO KEEP IN MIND ON LATER SHIFTS. DEEP MOISTURE WOULD THEN FILL BACK IN ON FRIDAY MORNING WITH ARRIVAL OF SHORTWAVE TROUGH/FAVORABLE DYNAMICS. BY TIME THE DEEPER MOISTURE RETURNS ON FRI...PTYPE WOULD BE LIQUID WITH SOUNDINGS SHOWING DEEP/MOIST WELL ABOVE FREEZING LAYER THROUGH 5KFT/H8. DID KEEP MENTION OF FZRA 12Z-15Z WHERE TEMPS WERE 35 DEGREES OR LOWER. EVENTUALLY COLDER AIR WORKS IN BUT IT IS NOT AS EMPHATIC AS IT LOOKED LIKE A COUPLE NIGHTS AGO. THUS...PTYPE FRI NIGHT AND/OR SAT COULD STILL HAVE SOME RAIN/SNOW. DOES BECOME SUFFICIENTLY COLD ENOUGH SAT NIGHT INTO SUN FOR JUST SNOW. 00Z MODELS SHOW SHORTWAVE CROSSING SO HAVE POTENTIAL FOR AT LEAST WIDESPREAD LIGHT SNOW ON SUN WITH SMALL CHANCE OF LES SUN NIGHT INTO MON BEHIND THAT SYSTEM. TWEAKED TEMPS DOWN SLIGHTLY FM CONSENSUS FOR MON AS 00Z ECMWF/GFS TRENDED COLDER THAN 12Z/15 SOLNS. ECMWF SHOWS -20C H85 TEMPS RETURNING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 643 AM EST TUE FEB 16 2016 A COLD FNT WL CROSS UPR MI TODAY...ACCOMPANIED BY SOME SCT -SHSN AND PREDOMINANT MVFR CONDITIONS. WITH A WSHFT TO THE NNW BEHIND THE FROPA...COLDER AIR WL FLOW OVER LK SUP AND RESULT IN MORE NMRS SHSN THAT WL BRING IFR VSBYS AT TIMES. THE LOWEST CONDITIONS ARE MORE LIKELY TO PREDOMINATE AT IWD...WHERE THE LLVL FLOW WL UPSLOPE AND SHARPER LLVL CNVGC WL FOCUS SOME HEAVIER SHSN. IFR CONDITIONS WL BE POSSIBLE AT CMX AND SAW AS WELL...BUT THESE LOWER VSBYS WL BE MORE TRANSIENT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 413 AM EST TUE FEB 16 2016 EXPECT LIGHT WSW WINDS THIS MORNING TO SHIFT TO THE NNW DURING THE DAY FOLLOWING A COLD FRONTAL PASSAGE AND INCREASE UP TO 30 KTS INTO THE EARLY MORNING HOURS ON WED UNDER A TIGHTENING PRES GRADIENT AHEAD OF HI PRES BUILDING INTO FAR NW ONTARIO ON WED MORNING. THERE MAY BE POCKETS OF HEAVY FREEZING SPRAY OVER PORTIONS OF THE NCENTRAL LAKE TONIGHT WITH THE INFLUX OF ARCTIC AIR. WINDS WILL DIMINISH TO UNDER 20KT WED AS HI PRES ARRIVES OVER THE UPPER LAKES. STRONGER SSE WINDS UP TO 30KT WILL THEN DEVELOP ON THU UNDER A TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING HI AND ANOTHER APPROACHING LO PRES. OVER THE E HALF OF THE LAKE...S GALES TO 35 KTS ARE LIKELY AT LEAST PART OF THE TIME ON THU AFTERNOON AND NIGHT. THE LO WILL PASS OVER OR JUST N OF LAKE SUPERIOR FRI. STRONG W TO NW WINDS UP TO 30KT WILL THEN FOLLOW INTO FRI NIGHT AND SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 AM EST TUE FEB 16 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 413 AM EST TUE FEB 16 2016 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW SOME UPR TROFFING CENTERED NEAR HUDSON BAY DOMINATING CENTRAL AND ERN NAMERICA. THERE IS AN APRCHG SHRTWV OVER NRN MN THAT IS EMBEDDED IN THE WNW FLOW ALF. AXIS OF MODEST DEEP LYR QVECTOR CNVGC AHEAD OF THIS FEATURE CAUSING 12HR H5 HGT FALLS UNDER 30M AS WELL AS SOME MODEST MSTR SHOWN ON THE WV IMAGERY/HINTED AT BY THE 00Z MPX RAOB IS RESULTING IN SOME SCT SN SHOWERS OVER THE W AND CENTRAL CWA EARLY THIS MRNG WELL TO THE E OF ACCOMPANYING SFC LO PRES TROF MOVING THRU NE MN. SHARP SUBSIDENCE INVRN NEAR H85 DEPICTED ON THE 00Z GRB RAOB IS KEEPING THE FAR ERN CWA DRY...BUT THERE IS A GOOD DEAL OF LO CLD TRAPPED BENEATH THIS INVRN. H85 TEMPS RIGHT ALONG THIS LO PRES TROF ARE NOT THAT COLD...AS 00Z H85 TEMP AT INL WAS ONLY -7C. FARTHER TO THE NNW...THE 00Z H85 TEMPS WERE -13C AT YPL AND -16C AT THE PAS MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS TODAY ASSOCIATED WITH APRCHG SHRTWV/LO PRES TROF AND THEN ON LES COVERAGE/INTENSITY TNGT AS COLDER AIR FOLLOWS IN THE NNW FLOW BEHIND THE TROF PASSAGE. TODAY...AS SHRTWV/AXIS OF ACCOMPANYING DEEP LYR FORCING AND DEEPER MSTR MOVE E TODAY...EXPECT THE SCT SN SHOWERS TO OVERSPREAD THE ENTIRE CWA THIS MORNING. BUT ALL THE SHORT TERM GUIDANCE HINTS THE MARGINAL FORCING/MSTR WL RESTRICT PCPN TOTALS WITH NO MORE THAN ABOUT AN INCH OF SN AT ANY ONE SPOT. BUT AS COLDER AIR MOVES IN TO THE NW CWA LATER IN THE DAY...LOWERING H85 TEMPS DOWN TO ABOUT -15C/- 16C OVER THE KEWEENAW BY 00Z WED...SOME MORE NMRS/HEAVER LK EFFECT SN SHOWERS MAY DVLP IN THAT AREA. SINCE SGNFTLY COLDER AIR WL NOT ARRIVE UNTIL LATER...GOING FCST HI TEMPS MAINLY IN THE 30S SEEMS ON TRACK. TNGT...LLVL NNW FLOW AHEAD OF APRCHG CNDN HI PRES THAT IS FCST TO REACH NEAR THUNDER BAY ONTARIO BY DAYBREAK WED WL DRIVE H85 TEMPS AS LO AS -18C TO -20C OVER THE E HALF LK SUP AT 12Z. THIS INFLUX OF COLD AIR WL SUPPORT LES IN THE FAVORED SN BELTS IN GOGEBIC/ONTONAGON COUNTIES AND FM MARQUETTE TO THE E. WHILE FCST SHARPER LLVL SFC CNVGC IN THESE AREAS AS WELL AS FAVORABLE LOCATION OF THE DGZ/LLVL UVV MAX WITHIN THE MOIST LYR ARE FAVORABLE FOR SOME HEAVIER LES... ARRIVAL OF DEEP LYR QVECTOR DVGC/MID LVL DRYING THAT ARE FCST TO LOWER THE INVRN BASE TO 3-4K FT AGL/MORE ACYC H925 FLOW BY 12Z WED WL ACT TO LIMIT LES INTENSITY. THERE COULD BE SOME PATCHY BLSN NEAR LK SUP MAINLY IN THE EVNG WHEN H925 WINDS ARE FCST UP TO 25 KTS DURING PERIOD OF SHAPER LLVL CAA THAT WL ENHANCE MIXING OF THIS MOMENTUM TO THE SFC. ALTHOUGH THERE COULD BE SEVERAL INCHES OF FLUFFY SN IN THE FAVORED SN BELTS...OVERALL LARGER SCALE NEGATIVES AND MARGINAL WINDS/BLSN POTENTIAL INDICATE THIS LES EVENT WL NOT REQUIRE A HEADLINE. MIN TEMPS TNGT WL FALL TO 5-10F OVER THE INTERIOR W HALF BUT SHOULD HOLD NO LOWER THAN THE MID TEENS IN THE FAVORED SN BELTS E OF MARQUETTE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 413 AM EST TUE FEB 16 2016 ...WINTRY MIX THU NIGHT INTO FRI... STRONG JET DIGGING INTO CNTRL CONUS RESULTS IN UPPER TROUGHING AND COLD AIR ACROSS GREAT LAKES ON WED. THEN...ENERGETIC PACIFIC JET OF 175-200KT AT H25...FORCES TROUGH CURRENTLY OVER EASTERN PACIFIC OVER WESTERN CONUS THU WITH DOWNSTREAM RIDGING SPREADING OVER GOOD PORTION OF CONUS...INCLUDING GREAT LAKES. WESTERN TROUGH HEADS TOWARD GREAT LAKES ON FRI ALONG WITH DEEPENING SFC LOW AND WARM FRONT. MODELS ARE GOING BACK AND FORTH ON HOW FAR NORTH PRIMARY SFC LOW TRACKS THU NIGHT THROUGH FRI NIGHT WHICH AFFECTS HOW QUICKLY WARM AIR ADVECTION AND MIXED PRECIP ISSUES ARRIVE OVER THE UPPER GREAT LAKES. IN WAKE OF THE SFC LOW...COOLER AIR MOVES BACK OVER UPPER GREAT LAKES NEXT WEEKEND...BUT EXTENT OF COOLING REMAINS UNCERTAIN. SWIFT WNW FLOW ALOFT COULD BRING ANOTHER DISTURBANCE AND SNOW CHANCES...MAINLY LATER IN THE WEEKEND. STARTING OFF ON WED...TROUGHING AND COLD AIR WILL BE TEMPORARILY IN PLACE. LOOKING AT H85 TEMPS -18C TO -20C...LOWEST OVER EASTERN LK SUPERIOR AND NORTHERN ONTARIO...BUT MODERATION OCCURS FAIRLY QUICKLY BY WED EVENING WITH RISING HEIGHTS ALOFT. TROUGH AXIS STAYING NORTHEAST OF UPPER GREAT LAKES LEADS TO LARGE SCALE SUBSIDENCE TAKING CHARGE BY WED MORNING WITH STRONG H7-H5 Q-VECTOR DIVERGENCE AND DRYING ABOVE H85. SFC HIGH OVER 1025MB SLIDING IN FM MANITOBA AND NORTHERN ONTARIO BRINGS ANTICYCLONIC SFC FLOW ACROSS LK SUPERIOR THOUGH NEUTRAL TO WEAKLY CYCLONIC FLOW MAY HANG AROUND FOR MORNING HOURS OVER EASTERN LK SUPERIOR AND DOWNSTREAM NCNTRL AND EASTERN CWA. AS THE HIGH BUILDS IN...THE INVERSION HEIGHTS FALL TO LESS THAN 4KFT OVER LK SUPERIOR. LAKE EQUILIBRIUM LEVELS SIMILAR OVER WEST BUT ARE MORE AROUND 6KFT OVER SCNTRL LK SUPERIOR DUE TO INCREASED FETCH WITH NNW TO N BLYR FLOW. DEEPER LAKE CONVECTIVE LAYER...BLYR WINDS 15-20 KTS HELPING ORGANIZATION...AND FAVORABLE DGZ MAY OFFSET THE NEGATIVE LARGE SCALE FACTORS TO HELP FLUFF UP A COUPLE INCHES OF SNOW ON WED MORNING. EXPECTED BLYR FLOW FAVORS SNOW BELTS OVER EASTERN MARQUETTE COUNTY INTO ALGER COUNTY AND MAYBE EVEN INTO DELTA AND SCHOOLCRAFT COUNTIES FOR PERSISTENT SNOW SHOWERS AND ACCUMS. SUBSIDENCE AND DRYING WITH THE HIGH EVENTUALLY WILL PUT CRIMP ON LES LATE WED MORNING INTO WED AFTN...THOUGH ONSHORE FLOW AND ENOUGH MOISTURE IN LOW-LEVELS WILL KEEP CLOUDS AND FLURRIES OVER PARTS OF CNTRL CWA UNTIL LATE AFTN. AWAY FM LAKE EFFECT...SCT STRATOCU MAY EXPAND WITH HEATING OF THE DAY...BUT WOULD ONLY BE FLURRIES INLAND DUE TO VERY LOW INVERSIONS AND NO SUPPORT IN LARGER SCALE. TEMPS IN THE TEENS MOST AREAS...BUT THAT IS AS COLD AS MAX TEMPS WILL BE THE REST OF THE WEEK. SFC RIDGE CENTERS OVER EAST HALF OF CWA WED EVENING THEN DRIFTS TO LOWER GREAT LAKES BY THU MORNING. BEST CHANCE OF CLEARING AND LIGHT WINDS WITH THE RIDGE WILL BE OVER EAST HALF IN THE EVENING. RISK OF LOW CLOUDS STAYING TRAPPED BENEATH INVERSION OVER WEST HALF. NAM IS MOST AGGRESSIVE ON THAT IDEA AND SOMETIMES HAS BIAS TO SO SUCH A SCENARIO. IN ANY CASE...RETURN FLOW AND/OR CLOUDS SHOULD KEEP TEMPS FM TANKING WEST...BUT THAT MIGHT NOT BE THE CASE OVER THE EAST. WILL KEEP FAVORING COLDER GUIDANCE THERE. RIDGE HEADS TOWARD NEW ENGLAND AND MID ATLANTIC ON THU WHILE BROAD AND RATHER COMPLEX AREA OF DEEP LOW PRESSURE SHIFTS FROM THE PACIFIC NORTHWEST AND BRITISH COLUMBIA ACROSS THE ROCKIES TOWARD THE NORTHERN PLAINS. SOUNDINGS INDICATE MID-HIGH CLOUDS LATER IN THE DAY BUT LOW-LEVELS STAY DRY. EXCEPTION IS OVER INTERIOR WEST HALF WHERE UPSLOPE SSE WINDS BTWN THE DEPARTING RIDGE AND APPROACHING LOW MAY HELP DEVELOP LOW CLOUDS/FLURRIES/FZDZ. WARM/MOIST ADVECTION ALOFT RAMPS UP THU NIGHT INTO FRI. SCENARIO NOT COMPLETELY CLEAR CUT THOUGH DUE TO DRYING ALOFT THAT IS SHOWN BY ECMWF...WHICH IS WPC FAVORED MODEL ATTM WITH THIS SYSTEM AND ALSO HAS BEEN MOST CONSISTENT WITH TRACK OF SFC LOW. WOULD SEE SOME SORT OF SNOW TO DZ/FZDZ TRANSITION IF DRYING ALOFT OCCURRED AND EVEN THE DZ/FZDZ RISK LATER THU NIGHT COULD BE AN IFFY PROPOSITION DUE TO LOW-LEVEL DRYING IN DRY SLOT OF APPROACHING SFC LOW. AREA OF CNTRL UPR MICHIGAN WITH SSE WINDS PROVIDING UPSLOPE AND MOISTURE OFF LK MICHIGAN MAY BE THE EXCEPTION. FOR NOW...SHOWED HIGHER/LIKELY POPS THU EVENING THEN TAPERED TO CHANCE POPS OVERNIGHT. THOUGH PTYPE WOULD BE MORE DZ/FZDZ KEPT WITH RAIN/FZRA. DID NOT WANT TO GET TOO SPECIFIC AS TIMING OUT A DRY SLOT AND ITS AFFECT ON PTYPE IS KIND OF RISKY 3 DAYS OUT. CONCERNED THAT COLD SFC TEMPS AND ROAD TEMPS MAY RESULT IN FZRA/ICING AT LEAST ON UNTREATED ROADS LATE THU NIGHT INTO FRI MORNING EVEN IF AIR TEMPS ARE SLIGHTLY ABOVE FREEZING. WILL BE SOMETHING TO KEEP IN MIND ON LATER SHIFTS. DEEP MOISTURE WOULD THEN FILL BACK IN ON FRIDAY MORNING WITH ARRIVAL OF SHORTWAVE TROUGH/FAVORABLE DYNAMICS. BY TIME THE DEEPER MOISTURE RETURNS ON FRI...PTYPE WOULD BE LIQUID WITH SOUNDINGS SHOWING DEEP/MOIST WELL ABOVE FREEZING LAYER THROUGH 5KFT/H8. DID KEEP MENTION OF FZRA 12Z-15Z WHERE TEMPS WERE 35 DEGREES OR LOWER. EVENTUALLY COLDER AIR WORKS IN BUT IT IS NOT AS EMPHATIC AS IT LOOKED LIKE A COUPLE NIGHTS AGO. THUS...PTYPE FRI NIGHT AND/OR SAT COULD STILL HAVE SOME RAIN/SNOW. DOES BECOME SUFFICIENTLY COLD ENOUGH SAT NIGHT INTO SUN FOR JUST SNOW. 00Z MODELS SHOW SHORTWAVE CROSSING SO HAVE POTENTIAL FOR AT LEAST WIDESPREAD LIGHT SNOW ON SUN WITH SMALL CHANCE OF LES SUN NIGHT INTO MON BEHIND THAT SYSTEM. TWEAKED TEMPS DOWN SLIGHTLY FM CONSENSUS FOR MON AS 00Z ECMWF/GFS TRENDED COLDER THAN 12Z/15 SOLNS. ECMWF SHOWS -20C H85 TEMPS RETURNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1220 AM EST TUE FEB 16 2016 FCST FOR TONIGHT WILL BE CHALLENGING AS LARGER SCALE SUBSIDENCE/LOWERING INVERSION IN THE PRESENCE OF NOCTURNAL COOLING MAY BRING ABOUT IFR CIGS LATE TONIGHT INTO TUE MORNING. EXPECT CIGS TO LOWER TO IFR DEVELOPING LATE OVERNIGHT/EARLY MORNING AT KIWD/KCMX...PARTLY IN RESPONSE TO SOME -SN SPREADING INTO THE AREA. KSAW MAY SEE A PERIOD OF IFR VSBYS IN LIGHT SNOW TUE AFTERNOON AS COLD FRONT MOVES ACROSS THE AREA. MVFR CONDITIONS IN LIGHT LAKE EFFECT SNOW WILL LINGER OVER THE AREA LATE TUE AFTERNOON INTO TUE EVENING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 413 AM EST TUE FEB 16 2016 EXPECT LIGHT WSW WINDS THIS MORNING TO SHIFT TO THE NNW DURING THE DAY FOLLOWING A COLD FRONTAL PASSAGE AND INCREASE UP TO 30 KTS INTO THE EARLY MORNING HOURS ON WED UNDER A TIGHTENING PRES GRADIENT AHEAD OF HI PRES BUILDING INTO FAR NW ONTARIO ON WED MORNING. THERE MAY BE POCKETS OF HEAVY FREEZING SPRAY OVER PORTIONS OF THE NCENTRAL LAKE TONIGHT WITH THE INFLUX OF ARCTIC AIR. WINDS WILL DIMINISH TO UNDER 20KT WED AS HI PRES ARRIVES OVER THE UPPER LAKES. STRONGER SSE WINDS UP TO 30KT WILL THEN DEVELOP ON THU UNDER A TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING HI AND ANOTHER APPROACHING LO PRES. OVER THE E HALF OF THE LAKE...S GALES TO 35 KTS ARE LIKELY AT LEAST PART OF THE TIME ON THU AFTERNOON AND NIGHT. THE LO WILL PASS OVER OR JUST N OF LAKE SUPERIOR FRI. STRONG W TO NW WINDS UP TO 30KT WILL THEN FOLLOW INTO FRI NIGHT AND SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1222 AM EST TUE FEB 16 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 406 PM EST MON FEB 15 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE ALONG THE W COAST OF THE CONUS/CANADA AND A DOWNSTREAM TROF OVER CNTRL/ERN N AMERICA WITH AXIS GENERALLY FROM THE WRN GREAT LAKES TO THE LWR MISSISSIPPI VALLEY. SHORTWAVE TROF THAT BROUGHT SOME -SN TO THE AREA LAST NIGHT/THIS MORNING HAS SHIFTED E OF THE AREA. KGRB RADAR AND SFC OBS/WEBCAMS SHOWED A BAND OF LAKE ENHANCED SNOW ALONG SFC TROF THAT MOVED OUT ACROSS LAKE MI LATE LAST NIGHT/THIS MORNING. AT LEAST AT LOCATIONS WITH WEBCAMS...IT DID NOT APPEAR THAT THERE WAS MORE THAN 2-3 INCHES OF SNOW WITH THE LAKE ENHANCEMENT...BUT THERE CERTAINLY COULD HAVE BEEN SOME ISOLATED HIGHER AMOUNTS. SOME -SN STILL LINGERS IN THE VCNTY OF THE WEAKENING TROF WHICH IS NOW INTO LUCE COUNTY. TO THE W...THERE HAVE BEEN SCT FLURRIES...BUT LATEST KMQT RADAR SUGGESTS THE FLURRIES HAVE MOSTLY DISSIPATED. UPSTREAM...NEXT SHORTWAVE OF INTEREST IS IN NRN MANITOBA/NRN SASKATCHEWAN. A GENERALLY QUIET EVENING IS EXPECTED. LINGERING -SN OVER THE FAR E WILL END THIS EVENING AS SFC TROF DRIFTS E AND WINDS BECOME WSW ACROSS NRN LAKE MI. THERE MAY BE A FEW FLURRIES ELSEWHERE... ESPECIALLY IF SMALL AREA OF -SHSN/FLURRIES OVER NE MN HOLDS TOGETHER. OVERNIGHT...AS SHORTWAVE IN MANITOBA/SASKATCHEWAN DROPS SE...THERE IS AN INCREASE IN MOISTURE DEPTH AND DEEP LAYER FORCING PER QVECTORS INTO THE WRN FCST AREA. WITH MOST MODELS GENERATING SOME PCPN...GRADUALLY INCREASED POPS THRU THE CHC CATEGORY OVER THE W OVERNIGHT. AS FOR TEMPS...WHILE CLOUDS SHOULD PERSIST ACROSS THE BOARD TONIGHT AND HOLD TEMPS UP...THERE IS SOME CONCERN THAT CLOUDS COULD BREAK FOR A TIME OVER PORTIONS OF THE CNTRL AND ERN FCST AREA WHERE LIGHT DOWNSLOPING OCCURS. THE BIAS CORRECTED REGIONAL AND GLOBAL CANADIAN MODELS WHICH ARE OFTEN SUPERIOR PERFORMERS WITH RADIATIONAL COOLING INDICATE MIN TEMPS DOWN INTO THE LWR SINGLE DIGITS FROM PARTS OF MENOMINEE COUNTY EASTWARD...WITH SOME TEMPS SUB ZERO TEMPS IN SCHOOLCRAFT COUNTY. FOR NOW...LOWERED TEMPS SLIGHTLY DOWN TOWARD 10F OVER PORTIONS OF THE ERN FCST AREA. ON TUE...AFOREMENTIONED SHORTWAVE SWINGS INTO THE UPPER GREAT LAKES WITH ASSOCIATED COLD FRONT REACHING THE KEWEENAW LATE MORNING/EARLY AFTN AND EXITING THE SE FCST AREA LATE AFTN/EARLY EVENING. BAND OF DEEP LAYER FORCING/DEEP MOISTURE WHICH BEGINS TO ARRIVE OVER THE W LATE TONIGHT SHIFTS ACROSS THE FCST AREA ON TUE. AS A RESULT...MOST AREAS SHOULD SEE SOME -SN AT SOME POINT TUE. UTILIZED CHC POPS. EXPECT A BURST OF HEAVIER SNOW TO ACCOMPANY COLD FRONT AS IT DROPS SSE ACROSS LAKE SUPERIOR AND INTO UPPER MI AS 850MB TEMPS ARE JUST COLD ENOUGH TO SUPPORT LAKE ENHANCEMENT. AS A RESULT...INCLUDED A SHORT PERIOD OF LIKELY POPS ALONG THE COLD FRONT AND INTO WRN/NRN UPPER MI WITH SNOW ACCUMULATIONS OF 1-2 INCHES NEAR THE LAKE. ELSEWHERE...ANY SNOW ACCUMULATION WILL BE UNDER 1 INCH. PATCHY BLSN SHOULD DEVELOP CLOSE TO THE LAKE FROM THE KEWEENAW EASTWARD AFTER FROPA. WITH AN OPPORTUNITY TO WARM UP PRIOR TO FROPA...TEMPS SHOULD TOP OUT AROUND 30F ACROSS THE FCST AREA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 314 PM EST MON FEB 15 2016 A 500MB TROUGH WILL BE SET UP ACROSS MUCH OF THE E THIRD OF THE NATION THROUGH WEDNESDAY. EXPECT ANOTHER BLAST OF COLD AIR TO SWING IN ON N WINDS TUESDAY NIGHT/WEDNESDAY...WITH 850MB TEMPS AVERAGING -16C. ACCOMPANYING THIS COLD AIR WILL BE ANOTHER SHORTWAVE TUESDAY NIGHT...AND INCREASED NNW WINDS...WHICH WILL COMBINE TO HELP CREATE SNOW AND BLOWING SNOW OVER THE KEWEENAW PENINSULA THROUGH WHITEFISH POINT. WILL CONTINUE TO MENTION THE POTENTIAL FOR LIGHT-MODERATE SNOW AND BLOWING SNOW IN THE HWO BEFORE WINDS DIMINISH W-E WEDNESDAY MORNING AS THE SFC HIGH SHIFTS OVERHEAD. HIGHS WEDNESDAY WILL STRUGGLE TO GET OUT OF THE TEENS. LOOK FOR THE 500MB RIDGE CURRENTLY PUSHING INTO THE W SEABOARD TO SHIFT E...AND BE CENTERED ACROSS THE PLAINS STATES THURSDAY MORNING. IT WILL BE A RACE TO SEE HOW LOW TEMPERATURES CAN FALL BEFORE HIGH CLOUDS NEAR FROM THE NW AND WAA TAKES COLD ON INCREASED S-SW WINDS THURSDAY MORNING AS 850MB TEMPS WARM TO AROUND -8C BY DAYBREAK THURSDAY. SINGLE DIGIT LOWS STILL LOOK REASONABLE. THE WAA WILL ALSO PUT AN END TO THE LES OFF E LAKE SUPERIOR EARLY WEDNESDAY EVENING. THE 500MB RIDGE WILL SWIFTLY SLIDE OVER THE GREAT LAKES REGION THURSDAY AFTERNOON/THURSDAY EVENING. LOOK FOR A TEMPORARY BREAK FROM THE SNOW...ALTHOUGH WAA SNOW MAY RETURN WITH THE PASSAGE OF THE WARM FRONT THURSDAY EVENING. MIXED PRECIP WILL BE A CONCERN. BY 00Z FRIDAY 850MB WINDS OUT OF THE S AT 40-55KT WILL HELP USHER 850MB TEMPS OF -3 TO +3C OVER THE CWA. THERE ARE ENOUGH DIFFERENCES IN THE FCST MODELS AT THIS DISTANCE TO GIVE MODERATE TO LOW CONFIDENCE IN SPECIFIC PRECIP TYPES...ALTHOUGH SNOW...FREEZING RAIN...AND RAIN WILL ALL BE POSSIBLE AT SOME POINT THURSDAY NIGHT INTO FRIDAY MORNING. WILL KEEP THE MENTION OF A WINTRY MIX OF PRECIP IN THE HWO. THAT WILL BE UNTIL SFC TEMPS WARM UP ENOUGH FOR MOST OF THE PRECIP TO FALL IN THE FORM OF RAIN. THE 00Z ECMWF AND 06Z GFS WERE FAIRLY IN LINE WITH SLIDING THE NEARING SFC LOW OVER MN EARLY FRIDAY MORNING...CROSSING UPPER MI/N LAKE MI DURING THE DAY...AND EXITING ACROSS LAKE HURON FRIDAY EVENING. THE 06Z CANADIAN MODEL WAS MUCH FARTHER TO THE N WITH THE LOW...WHICH WAS BACKED BY THE ECMWF YESTERDAY. OVERALL...THE GFS HAS BEEN MORE CONSISTENT OVERALL WITH THE TRACK. THE 12Z SOLUTIONS ARE COMING IN WITH AT LEAST SOME BETTER AGREEMENT ON THE TRACK OF THE LOW NEAR LAKE SUPERIOR FRIDAY AFTERNOON-EVENING...BUT STILL PLENTY OF TIME FOR CHANGES. COLDER AIR WILL FILTER IN BEHIND THE EXITING SFC LOW FRIDAY NIGHT. JUST HOW COLD IS ANOTHER QUESTION...AS THE GFS AND ECMWF VARY BY AROUND 5C...RANGING FROM -9C TO -2C /COLDEST OFF THE ECMWF/ BY 12Z SATURDAY. THIS COULD MAKE THE DIFFERENCE IN ALL SNOW OR LINGERING RAIN/SNOW MIX INLAND SATURDAY MORNING. W-NW WINDS WILL BE THE RULE FROM 00Z SATURDAY-00Z SUNDAY. WILL RUN WITH A BLENDED MODEL SOLUTION FOR SATURDAY NIGHT THROUGH NEXT MONDAY...AS THE NEXT 500MB TROUGH DIVES IN. THE SMALL SCALE DIFFERENCES ARE GOING TO BE DIFFICULT TO PERFECT AT THIS TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1220 AM EST TUE FEB 16 2016 FCST FOR TONIGHT WILL BE CHALLENGING AS LARGER SCALE SUBSIDENCE/LOWERING INVERSION IN THE PRESENCE OF NOCTURNAL COOLING MAY BRING ABOUT IFR CIGS LATE TONIGHT INTO TUE MORNING. EXPECT CIGS TO LOWER TO IFR DEVELOPING LATE OVERNIGHT/EARLY MORNING AT KIWD/KCMX...PARTLY IN RESPONSE TO SOME -SN SPREADING INTO THE AREA. KSAW MAY SEE A PERIOD OF IFR VSBYS IN LIGHT SNOW TUE AFTERNOON AS COLD FRONT MOVES ACROSS THE AREA. MVFR CONDITIONS IN LIGHT LAKE EFFECT SNOW WILL LINGER OVER THE AREA LATE TUE AFTERNOON INTO TUE EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 PM EST MON FEB 15 2016 WITH A WEAKENING PRES GRADIENT OVER THE UPPER LAKES...WINDS ACROSS LAKE SUPERIOR WILL DIMINISH TO UNDER 20KT TONIGHT INTO TUE MORNING. PASSAGE OF A COLD FRONT ON TUE AND TIGHTENING PRES GRADIENT AHEAD OF HIGH PRES BUILDING INTO MANITOBA WILL BRING A PERIOD OF STRONGER N WINDS UP TO 30KT TUE AFTN/NIGHT...WITH THE STRONGEST WINDS OVER THE CNTRL AND ERN PORTIONS OF LAKE SUPERIOR LATE TUE AFTN/EVENING. THERE MAY BE A FEW GALE FORCE GUSTS. IN ADDITION...EXPECT SOME HEAVY FREEZING SPRAY TO DEVELOP OVER PORTIONS OF CENTRAL LAKE SUPERIOR. WINDS WILL DIMINISH TO UNDER 20KT WED AS HIGH PRES ARRIVES OVER THE UPPER LAKES. STRONGER SSE WINDS UP TO 30KT WILL THEN DEVELOP ON THU UNDER A TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING HIGH AND ANOTHER APPROACHING LOW PRES. WINDS MAY INCREASE FURTHER TO GALES THU NIGHT OVER THE E HALF OF LAKE SUPERIOR. THE LOW WILL PASS OVER OR JUST N OF LAKE SUPERIOR FRI. STRONG W TO NW WINDS UP TO 30KT WILL THEN FOLLOW INTO FRI NIGHT AND SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
1136 PM CST MON FEB 15 2016 .UPDATE... ISSUED AT 711 PM CST MON FEB 15 2016 THE KDLH RADAR HAS SHOWN SNOW SHOWERS...SOME MODERATE TO HEAVY...MOVING THROUGH NORTHERN WISCONSIN AND FAR NORTHEASTERN MINNESOTA THIS EVENING. MOST OF THE MODELS WERE NOT DOING A GOOD JOB HANDLING THIS PRECIP. WE UPDATED POPS TONIGHT TO ACCOUNT FOR THE LATEST RADAR TRENDS. STEEP LAPSE RATES WERE IN PLACE AND WERE AIDING IN PRODUCING THE SNOW SHOWERS. WE ALSO INCREASED SNOW ACCUMULATION TONIGHT. SOME LOCALIZED AMOUNTS OF 2 TO 3 INCHES IS NOT OUT OF THE QUESTION WHERE SNOW SHOWERS MOVE OVER THE SAME AREA...MOST LIKELY OVER PORTIONS OF FAR NORTHERN WISCONSIN. MOST AREAS WILL RECEIVE LESS THAN AN INCH. EARLIER RUNS OF THE HRRR SUGGESTS EVEN HIGHER SNOWFALL OVER FAR NORTHWEST WISCONSIN...BUT RECENT VERSIONS HAVE BACKED OFF QUITE A BIT. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 318 PM CST MON FEB 15 2016 CURRENT RADAR IMAGERY DEPICTS AN AREA OF SNOW/FZDZ TRANSLATING EAST ACROSS NORTH CENTRAL MN AND INTO THE WESTERN LAKE SUPERIOR REGION. THE PRECIPITATION IS ASSOCIATED WITH A ZONE OF WARM AIR ADVECTION...ACCOMPANIED BY STEEP MID LEVEL LAPSE RATES AS 500HPA TEMPS ARE AROUND NEGATIVE 30C. THE PRIMARY PRECIPITATION TYPE WILL BE SNOW. HOWEVER...AREAS OF FREEZING DRIZZLE CAN NOT BE RULED OUT WITH ELEVATED DEW POINTS...SATURATED LOW LEVELS AND BUFR SOUNDINGS INDICATING FAVORABLE CLOUD TOP TEMPS FOR SUPER COOLED WATER DROPLETS. HAVE INCREASED POPS THIS EVENING FOR TWIN PORTS AND ARROWHEAD ZONES TO REFLECT CURRENT RADAR TRENDS. HOWEVER...THE PRECIPITATION WILL BE LIGHT WITH LITTLE OR NO SNOW ACCUMULATION. ELSEWHERE....AREAS OF FOG WILL PERSIST OVERNIGHT AS THE REGION REMAINS SITUATED IN THE WARM SECTOR AHEAD OF APPROACHING CANADIAN COLD FRONT. THE LEADING EDGE OF THE COLD AIR WILL MAKE ITS PUSH INTO THE BORDERLAND ZONES LATE TONIGHT...WITH 850HPA TEMPS FALLING INTO THE NEGATIVE TEENS ACROSS THE FORECAST AREA THROUGH THE DAY. THE COLD AIR AND NORTHERLY FLOW WILL PROMOTE LAKE EFFECT/ENHANCED SNOW SHOWERS ALONG THE SOUTH SHORE OF LAKE SUPERIOR. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 318 PM CST MON FEB 15 2016 AS THE SURFACE HIGH DRIFTS ACROSS MN AND WI EXPECT THE LAKE EFFECT SNOW SHOWERS TO DECREASE WEDNESDAY AS WINDS TURN SOUTHERLY ON THE BACKSIDE OF THE HIGH WEDNESDAY NIGHT. LINGERING COLD AIR OVER THE REGION AND CLEAR SKIES WILL MAKE IT ANOTHER COLD NIGHT...BUT THE RETURN FLOW MAY MEAN A QUICK BOTTOMING OUT OF THE TEMPS THEN BECOMING NEARLY STEADY OR MAYBE EVEN RISE OVERNIGHT. THERE WILL BE INTENSE WARM AIR ADVECTION ON THURSDAY WITH A STRONG LOW LEVEL JET DEVELOPING AHEAD OF LOW PRESSURE ADVANCING FROM THE ROCKIES. WITH A 50 KT 850HPA LOW LEVEL JET IT WON`T TAKE LONG FOR WARM AIR TO GET INTO OUR AREA. BY THURSDAY EVENING AN 8H WARM NOSE OF +8 TO +18C IS PROGGED WELL INTO CENTRAL MN AS SFC LOW MOVES OVER MN. THESE WARM TEMPS WILL BE HELPING TO PRODUCE MIXED TYPE OF PRECIPITATION AS THE SFC LOW AND FRONT MOVES THROUGH THURSDAY. THERE ARE STILL SOME DIFFERENCES OF TRACK OF THE LOW THE GFS KEEP SFC LOW OVER FAR NRN MN WHILE THE ECMWF BRINGS SFC LOW OVER SRN MN. MORE RESOLUTION WILL BE GIVEN IN THE FORECASTS AS TO TIMING AND TYPES AS THE WEEK PROGRESSES. THE REMAINDER OF THE EXTENDED PERIOD WILL BE DOMINATED BY A MORE ZONAL FLOW WITH EMBEDDED SHORTWAVES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1128 PM CST MON FEB 15 2016 A TROUGH OF LOW PRESSURE...SHORTWAVE ALOFT...AND 850-500MB LAPSE RATES FROM 6.5-7.5C/KM HAVE COMBINED TO PRODUCE SNOW SHOWERS THIS EVENING OVER NORTHWEST WISCONSIN AND PORTIONS OF FAR NORTHEAST MINNESOTA. THE SNOW SHOWERS WILL CONTINUE TO DIMINISH OVER NORTHEAST MINNESOTA...AND WILL DECREASE FROM WEST TO EAST OVER NORTHWEST WISCONSIN LATE TONIGHT INTO TUESDAY MORNING. CEILINGS RANGING FROM MVFR TO LIFR WILL PREVAIL TONIGHT BUT WILL IMPROVE DURING THE DAY TUESDAY. DRIER AIR MOVING IN TONIGHT WILL RAISE THE LIFR/IFR CEILINGS FROM NORTH TO SOUTH. WE IMPROVE CONDITIONS TO VFR FOR MOST TAF SITES LATE TUESDAY MORNING/EARLY AFTERNOON...BUT THERE MAY BE SOME STRATOCUMULUS THAT FORMS UNDER COLD AIR ALOFT DURING THE AFTERNOON. LAKE INDUCED MVFR CEILINGS SHOULD ALSO IMPACT KHYR TUESDAY AFTERNOON/EVENING. && .PRELIMINARY POINT TEMPS/POPS... DLH 20 25 0 18 / 70 30 0 10 INL 10 16 -10 17 / 10 10 0 10 BRD 22 27 1 21 / 20 20 0 10 HYR 20 31 4 22 / 80 50 10 10 ASX 22 31 7 20 / 80 50 40 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...NONE. && $$ UPDATE...MELDE SHORT TERM...GRANING LONG TERM...CLC AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
516 AM CST TUE FEB 16 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 320 AM CST TUE FEB 16 2016 THE MIDLEVEL CLOUDINESS THE CNTL AND NRN HIGH PLAINS STRETCHING FROM MT THROUGH WY...NRN COLO AND WRN NEB REPRESENTS A WELL ADVERTISED WARM FRONT ASSOCIATED WITH LOW PRESSURE ACROSS THE NRN HIGH PLAINS. THE CLOUDS AND THE WARMER AIR WILL ADVANCE SLOWLY EAST TODAY AS SFC LOW PRESSURE FILLS ACROSS THE NRN PLAINS. THE MIDLEVEL CLOUDINESS SHOULD PERSIST THROUGHOUT THE DAY AND MOVE EAST OF THE FCST AREA TONIGHT. THE LATEST BLEND OF GUIDANCE PLUS BIAS CORRECTION PRODUCES HIGHS MOSTLY IN THE 40S WITH 50S ACROSS SOUTHWESTERN NEB AND THE EASTERN PANHANDLE. NORTHWEST WINDS NEAR 15 MPH THIS MORNING BECOME WEST AND SLACKEN THIS AFTERNOON. LOWS TONIGHT FALL INTO THE UPPER 20S TO LOWER 30S WITH GENERALLY CLEAR SKIES DEVELOPING FROM WEST TO EAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 320 AM CST TUE FEB 16 2016 UPPER LEVEL RIDGING ALOFT WILL BUILD EAST ACROSS THE CENTRAL PORTION OF THE COUNTRY WEDNESDAY INTO THURSDAY AHEAD OF A LONG WAVE TROUGH/PACIFIC STORM SYSTEM THAT WILL BE MOVING ONTO THE WEST COAST. A THERMAL RIDGE WILL ACCOMPANY THE UPPER LEVEL RIDGING...WITH A COUPLE OF WARM DAYS EXPECTED WEDNESDAY AND ESPECIALLY THURSDAY. WILL BEGIN TO ADVECT WARMER AIR ALOFT NORTH/NORTHEAST INTO THE AREA WEDNESDAY...WITH H850MB TEMPERATURES RISING TO BETWEEN 7C AND 10C BY WEDNESDAY EVENING. BY THURSDAY...THE THERMAL RIDGE WILL BE ORIENTED FROM CENTRAL AND WESTERN NEBRASKA...SOUTHWARD THROUGH WESTERN KS AND THE TX/OK PANHANDLE REGION. H850MB TEMPERATURES WILL REACH AS WARM AS 25C ACROSS WESTERN KS AND THE OK/TX PANHANDLE...WITH A TONGUE OF OF 18C TO 21C EXTENDING NORTHWARD ACROSS OUR REGION. THESE TEMPERATURES ALOFT SHOULD SUPPORT HIGHS IN THE MID 60S TO LOWER 70S ACROSS THE ENTIRE FORECAST AREA. THERE WILL BE SOME CIRRUS CLOUD COVER...BUT EXPECTING THIS TO HAVE MINIMAL IMPACT ON TEMPERATURES DUE TO A WELL MIXED LOWER ATMOSPHERE. THE AFOREMENTIONED LONG WAVE TROUGH WILL DAMPEN AND QUICKLY MOVE EAST ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY NIGHT AND FRIDAY. SEEING A SIGNAL IN THE MODELS THAT INDICATE STRONG WINDS COULD ACCOMPANY THE PACIFIC COLD FRONT THURSDAY NIGHT. THE GFS AND NAM MODELS BOTH MOVE A MODEST TROP FOLD/PV ANOMALY RIGHT THROUGH THE FORECAST AREA. THIS COULD...AND HAS IN THE PAST...HELP MIX STRONGER WINDS ALOFT TO THE SURFACE. WILL BUMP WINDS UP A BIT WITH THIS FORECAST CYCLE...AND CONTINUE THE STRONG WIND MENTION IN THE HAZARDOUS WEATHER OUTLOOK. PRECIPITATION WITH THIS SYSTEM WILL STAY MAINLY NORTH AND NORTHEAST OF THE AREA WHERE BETTER MOISTURE AND STRONGER LIFT WILL BE LOCATED. IT WILL REMAIN MILD IN THE WAKE OF THE SYSTEM FRIDAY AND SATURDAY AS A PACIFIC AIRMASS REMAINS IN PLACE. A SYSTEM CROSSING CANADA SUNDAY WILL DRIVE A WEAK CANADIAN COLD FRONT SOUTH THROUGH THE AREA...WITH HIGHS SETTLING BACK INTO THE 40S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 516 AM CST TUE FEB 16 2016 MVFR/IFR CIGS ACROSS HOLT COUNTY AND ADJOINING AREAS IMPROVE TO MVFR THIS MORNING. THE RAP MODEL INDICATES MVFR/IFR CIGS MAY RETURN THIS EVENING BEFORE A WARM FRONT MOVES EAST OF THE FCST AREA LATE TONIGHT. VFR IS EXPECTED ELSEWHERE TODAY AND TONIGHT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
317 AM CST TUE FEB 16 2016 ...TEMPS NOT QUITE AS WARM AS YESTERDAY BUT STILL ABOVE NORMAL AND TEMPS WILL SURGE TO SIGNIFICANTLY WARMER THAN NORMAL THU-SAT WITH POSSIBLE FIRE WX CONCERNS N-CNTRL KS THU... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 317 AM CST TUE FEB 16 2016 ALOFT: SIMILAR TO 24 HRS AGO...A VORT MAX WAS MOVING THRU THE NRN PLAINS ON ITS WAY INTO THE ERN USA TROF. NW FLOW WILL REMAIN LOCKED IN THRU TONIGHT. A LOW WAS MOVING INTO SW CANADA. A WEAK VORT MAX WILL TOP THE RIDGE AND HEAD SE INTO ND BY 00Z/WED AND INTO IA/IL BY 12Z. SURFACE: A WEAK COOL FRONT PASSED THRU LAST EVENING. IN ITS WAKE ...A SMALL HIGH PRES CENTER WAS SLIDING DOWN THE FRONT RANGE. THIS HIGH WILL DEPART TO THE E LATE THIS AFTERNOON WHILE A NEW LOW CREEPS DOWN THE FRONT RANGE WITHIN THE REDEVELOPING LEE TROF. THIS LOW WILL EXIT THE TROF INTO SD TONIGHT...WITH A WARM FRONT FORMING TO ITS S. THIS FRONT WILL HEAD E SHOULD EXTEND FROM THE SANDHILLS SE INTO ERN KS BY DAYBREAK WED. NOW: CAA IS STRONGEST RIGHT NOW AND PEAKS PRIOR TO SUNRISE. MID- HIGH CLOUDS ARE CLEARING BEHIND THE DEPARTING VORT MAX...EXCEPT FOR THE BAND OF 7-11K FT CLOUDS FROM THE PANHANDLE SE INTO NW KS. THESE CLOUDS ARE NOT BEING MODELED WELL...AND THIS IS BOTHERSOME. THE 07Z AND 08Z RAP HAVE IT BUT QUICKLY ERASE IT WHICH IS NOT HAPPENING. IF THIS CLOUD DECK STICKS AROUND LONGER THAN EXPECTED THAT WILL BUST THE TEMP FCST OVER THE SW 1/3 OF THE FCST AREA. ORD GUSTED TO 40 KTS AT 821Z. TODAY: CAA WILL DIMINISH THIS MORNING AS PRES GRAD WEAKENS. WEAK WAA DEVELOPS THIS AFTERNOON AS WINDS BACK. NW WINDS WILL GUST 25-35 MPH UNTIL NOON. ONE-TIME PEAK G35-45 POSSIBLE...BUT NOT EVERYWHERE. HIGHEST GUSTS BEFORE 9 AM. VARIABLE CLOUD COVER WILL BE HARD TO ACCT FOR. WE SHOULD SEE A CONSIDERABLE AMT OF STRATOCU IN THE THERMAL TROF OVER THE E 1/2 OF THE FCST AREA. AS WINDS BACK AND WAA DEVELOPS...THE BACK EDGE OF THIS STRATOCU WILL DEPART TO THE E. HOWEVER...MULTI-MODEL CROSS SECTIONS SUGGEST MID-HIGH CLOUDS WILL RE-INVADE FROM THE NW THIS AFTERNOON. LOWERED HIGHS 2-3F FROM THE PRVS FCST. TONIGHT: M/CLOUDY THRU MIDNIGHT WITH MULTIPLE DECKS OF MID-HIGH CLOUDS...THEN CLEARING. LEFT LOW TEMPS NEARLY IDENTICAL TO PRVS FCST. ANOTHER MILD NIGHT WITH LOWS 10F WARMER THAN NORMAL. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 317 AM CST TUE FEB 16 2016 THE MAIN FORECAST CONCERN FOR THE MID AND LONG TERM PERIODS IS THE TEMPERATURES. IT WILL BE WELL ABOVE NORMAL...WITH THURSDAY APPROACHING RECORD TEMPERATURES IN SOME AREAS. THE NORMAL TO ABOVE NORMAL TREND WILL CONTINUE THROUGH THE END OF THE FORECAST. WEDNESDAY - SATURDAY: THIS PERIOD OF THE FORECAST WILL BE THE WARMEST. HIGHS WILL BE AROUND 20-30 DEGREES ABOVE NORMAL FOR MID FEBRUARY. THE UPPER LEVEL RIDGE WILL APPROACH ON WEDNESDAY AND MOVE OVERHEAD WEDNESDAY NIGHT INTO THURSDAY. WINDS WILL QUICKLY BECOME SOUTHERLY WEDNESDAY AS LEE TROUGHING DEVELOPS. THE LEE LOW WILL DEEPEN AND A SURFACE LOW WILL DEVELOP IN THE HIGHER TERRAIN OF THE NORTHERN PLAINS. THIS WILL CAUSE THE WIND FIELD TO BECOME MORE SOUTHWESTERLY ACROSS THE AREA THURSDAY. THE PRESSURE GRADIENT WILL SLACKEN OVER THE CENTRAL HIGH PLAINS ALLOWING WINDS TO NOT BE QUITE AS STRONG DURING THE DAY THURSDAY. THIS IN KEY FOR FIRE WEATHER CONCERNS... SEE DISCUSSION BELOW. ABUNDANT INSOLATION FOR MUCH OF THURSDAY AND THE STRONG WARM AIR ADVECTION AND MIXING WILL ALLOW TEMPERATURES TO REACH ABOUT 30 DEGREES ABOVE NORMAL...CURRENTLY STAYING SHY OF RECORD TEMPERATURES...BUT WILL NEED TO WATCH. SEE THE CLIMATE SECTION BELOW FOR MORE DETAILS. THE UPPER TROUGH APPROACHING FROM THE WEST WILL SLIDE OVERHEAD THURSDAY NIGHT. THE MAIN ENERGY WILL BE ACROSS NORTHERN NEBRASKA WHICH SHOULD KEEP THE MAIN PRECIP NORTH OF THE AREA. THIS WAVE WILL PULL A FRONT THROUGH THE REGION THURSDAY NIGHT...BUT BECAUSE IT IS NOT A CANADIAN AIRMASS...TEMPERATURES WILL BE HAMPERED ONLY SLIGHTLY WITH HIGHS AGAIN ON FRIDAY ABOVE NORMAL. WITH AN ACTIVE UPPER PATTERN ANOTHER FRONT WILL MOVE INTO THE AREA SATURDAY AFTERNOON...AGAIN NOT IMPACTING THE AIRMASS MUCH. HIGHS ON WEDNESDAY WILL BE IN THE 50S AND 60S BEFORE INCREASING ON THURSDAY INTO THE 60S AND LOW 70S. THE PASSAGE OF THE PACIFIC FRONT ON THURSDAY NIGHT WILL KNOCK TEMPS BACK INTO THE LOW 60S FOR FRIDAY AND SATURDAY. OVERALL THE END OF THE WORK WEEK AND START OF THE WEEKEND IS EXPECTED TO BE PLEASANT. SUNDAY - MONDAY: A SECONDARY FRONT WILL PUSH IN EARLY SUNDAY WITH A REINFORCING SHOT OF COOLER AIR. HIGHS ON SUNDAY AND MONDAY WILL BE IN THE 50S AND 40S RESPECTIVELY. THE PERIOD REMAINS ACTIVE WITH MULTIPLE DISTURBANCES MOVING ACROSS THE NORTHERN PLAINS AND NORTHWESTERLY UPPER LEVEL FLOW INCREASING INTO MONDAY. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUE NIGHT) ISSUED AT 1150 PM CST MON FEB 15 2016 SIGNIFICANT WX: NW WINDS WILL INCREASE AND GUST UP TO 35 KTS THRU 15Z. REST OF TONIGHT: VFR CIGS 9-12K FT. SOME SCT CLOUDS 4-6K FT POSSIBLE. THEN 2000-2500 FT MVFR STRATUS INVADES AROUND 09Z. NW WINDS INCREASE AND GUST UP TO 35 KTS. CONFIDENCE: LOW MAINLY DUE TO UNCERTAINTY ON IF MVFR CIGS MOVE IN. FCST GUIDANCE MAY BE TOO LOW WITH ITS CIGS. THERE IS NOT A LOT OF MVFR CIGS UPSTREAM. TUE: MVFR CIGS? BEST CHANCE AT GRI AS EAR WILL BE ON THE WRN EDGE AND MAY ONLY BE SCT025. MULTI-LAYERED MID-HIGH CLOUDS AT OR ABOVE 8K FT WILL INVADE AFTER 18Z. NW WINDS GUST UP TO 35 KTS UNTIL 18Z. THEN WINDS GRADUALLY SUBSIDE. CONFIDENCE: LOW DUE TO UNCERTAINTY ON MVFR CIGS. TUE EVE: VFR CIGS AROUND 8K FT. NW WINDS CONT TO SUBSIDE AND SHIFT TO SW. CONFIDENCE: HIGH && .FIRE WEATHER... ISSUED AT 317 AM CST TUE FEB 16 2016 FIRE WEATHER COULD STILL BE A CONCERN OVER MAINLY NORTH CENTRAL KANSAS...WHERE FUELS HAVE THE BEST CHANCE OF BEING DRY AND OTHER CONDITIONS FAVOR FIRE GROWTH. HOWEVER...THERE ARE A LOT OF CONCERNS REGARDING FAVORABLE FIRE GROWTH...WETTER FUELS...WIND SPEEDS AND RH`S. DUE TO RECENT SNOW MELT FUELS MAY BE TOO WET. THE BETTER PRESSURE GRADIENT WILL BE FURTHER TO THE SOUTH OF THE NORTH CENTRAL KANSAS AREA WHICH COULD LIMIT WIND SPEEDS ON THURSDAY AFTERNOON WHEN RH VALUES ARE EXPECTED TO BE THE LOWEST...AROUND 25 PERCENT. WILL ALLOW LATER SHIFTS...ESPECIALLY THE DAY SHIFT TO COORDINATE FUELS AND SEE HOW THE FORECAST TRENDS. && .CLIMATE... ISSUED AT 317 AM CST TUE FEB 16 2016 RECORD HIGHS FOR FEBRUARY 18TH GRAND ISLAND.....71 DEGREES IN 1948 HASTINGS.........74 DEGREES IN 1930 && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...HALBLAUB LONG TERM...BILLINGS WRIGHT AVIATION...HALBLAUB FIRE WEATHER...BILLINGS WRIGHT CLIMATE...BILLINGS WRIGHT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1118 PM CST MON FEB 15 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 335 PM CST MON FEB 15 2016 THE MAIN FORECAST CHALLENGES THROUGH TUESDAY AFTERNOON ARE PRECIPITATION AND TEMPERATURES. A POTENT SHORTWAVE ALONG WITH A SURFACE/LOW LEVEL TROUGH WILL CROSS THE FORECAST AREA THIS EVENING AND TONIGHT. THE CIRRUS DECK...WHICH EXTENDS INTO THE DAKOTAS AND MONTANA BASED ON IR/WV...HAS BEEN RATHER DENSE TODAY WHICH HAS SLOWED THE RISE IN TEMPS. DESPITE MID/UPPER LEVEL MOISTURE AND WEAK RADAR ECHOES OVER THE PANHANDLE AND NORTHWEST NEBRASKA TODAY...ABUNDANT DRY LEVEL AIR HAS JUST LED TO VIRGA. THIS EVENING AND TONIGHT...EXPECT SATURATION TO SLOWLY WORK DOWN TO ABOUT 800-850HPA AS INDICATED IN NAM...GFS...AND RAP FORECAST SOUNDINGS. THE RAP ALSO SHOWS SUFFICIENT LOW LEVEL LIFT TO SUPPORT SHOWER ACTIVITY...ESPECIALLY ACROSS NORTHERN NEBRASKA. BASED ON SOME VIRGA IN SOUTHWEST NEBRASKA AND LAPSE RATES OF 7-8C/KM DIRECTLY ABOVE THE SFC INVERSION FROM RAP SOUNDINGS...EXPANDED SCHC MENTION TO COVER THE REST OF THE CWA. A 120+KT 250HPA JET ENTERS THE AREA LATE TONIGHT...ADDING TO THE UPPER LEVEL DYNAMICS AND DIVERGENCE. WITH SFC TEMPS IN THE UPPER 30S/LOWER 40S THROUGH 06Z AND SFC WET BULB AOA 0C...EXPECT PREDOMINANT PTYPE TO BE RAIN. DRY AIR ENTRAINS INTO THE SYSTEM FROM THE WEST BY 06Z...LIMITING PRECIP CHANCES TO NORTH CENTRAL NEB. CUT MENTION TO SPRINKLES NEAR KONL WITH BULK OF MOISTURE STAYING BELOW 800HPA AND THE LOSS OF APPRECIABLE LIFT. A FEW SNOWFLAKES MAY MIX IN AT THE END...BUT MOISTURE REALLY SHUTS OFF WHEN THE TEMPERATURE PROFILE WOULD SUPPORT FZRA OR RASN. MADE LITTLE ADJUSTMENT TO MIN TEMPS AS THEY GENERALLY LIE NEAR MOS GUIDANCE...PRIMARILY MAV AND ECM. TEMPS REMAIN RATHER MILD DUE TO CONTINUED CLOUD COVER AND GUSTY WINDS. WENT SLIGHTLY ABOVE GUIDANCE FOR WIND SPEED DURING THE FROPA AS NORTHWEST 850HPA WINDS OF 35-45KTS ARE SHOWN BY THE NAM AND RAP. CONFIDENCE IN MIN TEMPS A LITTLE LOWER SOUTH OF I-80 WHERE SOME PARTIAL CLEARING AND LIGHTENING OF WINDS TOWARD DAWN IS POSSIBLE...LEADING TO COOLER TEMPS. TUESDAY...TRENDED MAX TEMPS DOWN A DEGREE OR SO FOR MOST LOCATIONS BUT STILL REMAIN MILD WITH 50S SW AND 40S NC. MODELS SHOW CAA FOR MOST OF THE DAY AND 850HPA TEMPS BELOW 0C UNTIL 00Z WED. ANOTHER MOSTLY CLOUDY DAY IS LIKELY AS THE MOISTURE PLUME AS SHOWN BY WV IMAGERY EXTENDS WELL TO THE NORTHWEST. ALSO...ANOTHER BOUNDARY EXITS THE PANHANDLE IN THE AFTERNOON...HELPING ENHANCE LOWER LEVEL LIFT. THE NAM SHOWS BROAD ISENTROPIC LIFT AT 290K ACROSS THE SANDHILLS AFTER 18Z AND 500HPA TEMPS NEAR -20C. FAR WEST/PANHANDLE...WHERE DOWNGLIDE WILL TAKE EFFECT EARLIER AFTER THE BOUNDARY PASSAGE AND 850HPA WAA...MAX TEMPS MAY BE ON THE COOL SIDE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 335 PM CST MON FEB 15 2016 LONG TERM DOMINATED BY ABOVE NORMAL TEMPERATURES AND LITTLE IF ANY CHANCE FOR PRECIPITATION. DURING THE MIDDLE PART OF THE WORK WEEK THE WESTERN RIDGE WILL MIGRATE EAST AND AMPLIFY OVER THE PLAINS. A WARM FRONT WILL LIFT ACROSS THE AREA WITH A THERMAL RIDGE PEAKING ON THURSDAY BEFORE A COLD FRONT MOVES THROUGH THURSDAY NIGHT. WITH THE FRONTAL PASSAGE A SLIGHT CHANCE FOR A RAIN SHOWER IS POSSIBLE NEAR THE NEB/S DAKOTA BORDER...HOWEVER WOULD NOT BE SURPRISED IF THE DRY LOWER LEVELS IS TOO MUCH TO OVERCOME AND NOTHING REACHING THE GROUND. BEHIND THE FRONT WEAK RIDGING REBUILDS QUICKLY ACROSS THE ROCKIES...KEEPING TEMPS ABOVE SEASONAL NORMS INTO THE WEEKEND. WARMEST DAY OF THE PERIOD IS EXPECTED TO BE THURSDAY AS MODELS SURGE 850 MB TEMPS WELL INTO THE TEENS TO AROUND 20 C. MOS GUIDANCE IS ALSO UNSEASONABLY HIGH WITH UPPER 60S TO LOWER 70S. SHOULD HAVE MOST OF THE SNOW MELTED BY THEN AND MODELS INDICATING BREEZY CONDITIONS SO MIXING SHOULD BE REALIZED AND FORECAST FOLLOWS CLOSE TO GUIDANCE. RECORDS THIS TIME OF YEAR ARE LOWER 70S...SO WILL HAVE TO MONITOR AS A RECORD HIGH MAY BE REACHED. ALSO GOING TO HAVE TO WATCH FIRE CONDITIONS...AS OFTEN WITH RECORD WARMTH IS A HIGH FIRE DANGER. MIN RH VALUES LIKELY NEAR 20 PERCENT IN A FEW LOCATIONS...AND COULD BE LOWER. WHILE THE PACIFIC COLD FRONT THURSDAY NIGHT WILL KNOCK DOWN TEMPS FOR THE WEEKEND...GUIDANCE STILL HAS TEMPS REBOUNDING TO AROUND 60...WHICH WILL BE ABOVE NORMAL. ANOTHER WEAK COLD FRONT WILL ARRIVE OVER THE WEEKEND WITH ANOTHER COOL DOWN EXPECTED. LIMITED MOISTURE WITH THIS FRONT AND FORECAST REMAINS DRY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1115 PM CST MON FEB 15 2016 CEILING TONIGHT AND TUESDAY WILL BE ABOVE 6000 FEET AGL WITH VISIBILITY GREATER THAN 5SM. A FEW LIGHT SHOWERS CAN BE EXPECTED TO CONTINUE UNTIL 09Z IN WESTERN NEBRASKA. AN UPPER FRONT IS EXPECTED TO MOVE ACROSS LATE TONIGHT. THE RESULTING WIND AT 1500-2000 FEET AGL WILL BE 300-340 AND INCREASE TO 45KT. IN THE NORTH...THE WIND WILL TRANSFER TO THE SURFACE THOUGH SURFACE FRICTION WILL REDUCE IT TO 18G26KT. IN THE SOUTHWEST...THE WIND IS LIKELY TO REMAIN CUT OFF FROM THE SURFACE BY A SURFACE TEMPERATURE INVERSION. THIS WILL RESULT IN SUBSTANTIAL LOW LEVEL WIND SHEAR IN LOW LYING AREAS SUCH AS THE NORTH PLATTE RIVER VALLEY. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SNIVELY LONG TERM...MASEK AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1045 PM CST MON FEB 15 2016 .SHORT TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 300 PM CST MON FEB 15 2016 NEXT CLIPPER SYSTEM WAS LOCATED OVER WESTERN NORTH DAKOTA AT 20Z WITH MILD TEMPERATURES FOUND ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA. MAIN CONCERN TONIGHT WILL BE TIMING OF THE FEATURE AS IT MOVES SOUTHEAST ALONG WITH EXTENT AND TYPE OF PRECIP. 19Z RUC BRINGS THE SURFACE LOW INTO EASTERN NEBRASKA PRIOR TO 06Z AND INTO CENTRAL MISSOURI BY 12Z. WITH SURFACE TEMPERATURES EXPECTED TO REMAIN ABOVE FREEZING IN MOST AREAS THROUGH 06Z PRECIP SHOULD BE LIQUID DURING THAT TIME THEN CHANGE OVER TO SNOW OR A RAIN SNOW MIX NORTH TO SOUTH AS TEMPERATURES COOL ALOFT AND SYSTEM TRACKS TO THE SOUTHEAST. SOME POTENTIAL FOR ISOLATED THUNDER IN THE FAR SOUTHEAST LATE TONIGHT WHERE SOME MID LEVEL INSTABILITY INDICATED. LATEST DAY1 OUTLOOK FROM SPC SHOWS AN AXIS FOR GENERAL THUNDER INTO CENTRAL MISSOURI. COOLER AIR FOLLOWS BEHIND THE SYSTEM ON TUESDAY WITH WEAK HIGH PRESSURE OVER THE REGION. WARM ADVECTION BEGINS TUESDAY NIGHT INTO WEDNESDAY AS WESTERN RIDGE STARTS TO MOVE EAST WITH SPRING LIKE TEMPERATURES FOR THE AREA ON THURSDAY. SOUTHEAST PARTS OF THE AREA WHICH HAVE BEEN SNOW FREE FOR MOST OF THE MONTH MAY APPROACH 70. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 300 PM CST MON FEB 15 2016 MILD PATTERN CONTINUES THROUGH THE PERIOD AS FLOW REMAINS NEARLY ZONAL. SOME PRECIP MAY CLIP NORTHERN PARTS OF THE AREA THURSDAY NIGHT AS FAST MOVING SHORT WAVE TRACKS ACROSS THE NORTHERN PLAINS BUT OTHERWISE LOOKS DRY AFTER THAT. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1036 PM CST MON FEB 15 2016 LIGHT RAIN IS ALREADY IN THE AREA AND WILL AFFECT SITES FOR THE NEXT FEW HOURS. AM GROWING SKEPTICAL OF A RAIN-SNOW MIX...BUT HELD ONTO MENTION AT KOMA/KOFK AS TEMPERATURES ARE FALLING INTO THE 30S. THAT SAID...DO THINK RAIN WILL DOMINATE...AS UPSTREAM OBS ARE STILL RAIN FOR QUITE A WAYS. MVFR CEILINGS ARE STILL EXPECTED TO FOLLOW THE RAIN AND LINGER THROUGH AT LEAST AROUND MIDDAY. STILL LOW CONFIDENCE ON WHETHER CEILINGS WILL SLIP INTO THE IFR RANGE...AND HAVE LEFT LOW-END MVFR FOR NOW. ALSO SOME UNCERTAINTY ON WHEN CEILINGS WILL BREAK...WITH VFR CEILINGS TO FOLLOW FOR THE REST OF THE TAF CYCLE. NORTHWEST WINDS WILL INCREASE WITH/BEHIND THE PRECIPITATION...CONTINUING THROUGH AFTERNOON BEFORE SLACKENING IN THE LATE AFTERNOON/EARLY EVENING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT LONG TERM...FOBERT AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
730 PM EST WED FEB 17 2016 .SYNOPSIS... A QUICK MOVING UPPER LEVEL TROUGH OF LOW PRESSURE WILL CROSS THE NORTH COUNTRY TONIGHT AND BRING SNOW SHOWERS TO THE AREA...ESPECIALLY IN THE MOUNTAINS. ANY SNOW ACCUMULATIONS WILL GENERALLY BE A DUSTING TO TWO INCHES. COLDER AND DRIER AIR FOLLOWS IN BEHIND THIS SYSTEM FOR THURSDAY WITH BELOW NORMAL TEMPERATURES EXPECTED. A WARMING TREND BEGINS FRIDAY AND CONTINUES RIGHT INTO THE WEEKEND WITH HIGH TEMPERATURES CLIMBING BACK INTO THE 40S. && .NEAR TERM /THROUGH THURSDAY/... AS OF 638 PM EST WEDNESDAY...REGIONAL COMPOSITE RADAR MOSAIC SHOWS SOME LIGHT RETURNS FROM THE CHAMPLAIN VALLEY EASTWARD, ALONG AND AHEAD OF A COLD FRONT WHICH IS NOW ADVANCING INTO WESTERN ST. LAWRENCE COUNTY. MUCH OF THIS IN THE CHAMPLAIN VALLEY IS VIRGA DUE TO DRY SUB-CLOUD AIR. FRONT WILL CONTINUE TO PUSH EASTWARD, WITH THE BEST CHANCE FOR LIGHT ACCUMULATING SNOW (AROUND 2 INCHES OR LESS) ACROSS THE MOUNTAINS. THOUGH FORECAST IS GENERALLY HOLDING UP TO THIS POINT, I`VE TRIED TO BETTER REFINE POPS WITH THIS UPDATE, ESSENTIALLY LOWERING THEM IN LOWER ELEVATIONS AND ADJUSTING UPWARD A TAD ABOVE THE 1000` ELEVATIONAL BAND THROUGH MIDNIGHT. WITH THE FRONTAL PASSAGE AND ASSOCIATED UPPER TROUGH PASSAGE, SHARP LOWER TO MID TROPOSPHERIC COLD ADVECTION AND DRYING SHOULD THEN COMMENCE THROUGH LATE EVENING ACROSS NORTHERN NEW YORK AND AROUND/AFTER MIDNIGHT ACROSS VERMONT. BY THAT POINT CLEARING SKIES AND QUICKLY FALLING TEMPERATURES IS THE RULE. HOWEVER BTV-4 AND RAP BUFKIT SOUNDINGS SHOW SHALLOW RH LAYER UNDERNEATH INVERSION AROUND MOUNTAIN SITES, SUGGESTING LINGERING CLOUDS AND PERHAPS RIMING IN THESE AREAS INTO THE AM HRS. LOW TEMPERATURES REMAIN ON TRACK...IN THE TEENS ACROSS VERMONT TO 0 TO 5 BELOW ACROSS NORTHERN NEW YORK. BEST CHANCE AT SUB-ZERO LOWS IN THE ST. LAWRENCE VALLEY GIVEN FRESH SNOWPACK AND EARLIER CLEARING. PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 307 PM FOLLOWS... UPPER TROUGH AXIS EXTENDS FROM SOUTHWEST QUEBEC PROVINCE SOUTHWESTWARD TO THE WESTERN TIP OF LAKE ONTARIO THIS AFTERNOON. FEATURE IS MOVING EASTWARD WITH NARROW BAND OF MOISTURE JUST AHEAD OF THE TROUGH AXIS. EXPECTING ABOUT A 3 TO 6 HOUR WINDOW OF SNOW/SNOW SHOWERS WITH THE TROUGH...ESPECIALLY OVER THE MOUNTAINS. LOOKING AT A DUSTING TO TWO INCHES WITH THE BEST CHANCE FOR ANY ACCUMULATING SNOW BEING IN THE MOUNTAINS. BEHIND THE TROUGH AXIS I LITTLE IN THE WAY OF ANY CLOUD COVER...THUS LOOKING AT ANY PRECIPITATION QUICKLY COMING TO AN END AFTER MIDNIGHT. SKIES WILL ALSO BE CLEARING BEHIND THE TROUGH AND WITH COLD AIR ADVECTION DEVELOPING OVERNIGHT LOWS ACROSS THE SAINT LAWRENCE VALLEY AND NORTHERN ADIRONDACKS OF NEW YORK SHOULD FALL INTO THE ZERO TO 5 BELOW RANGE WHILE LOWS REMAIN IN THE TEENS FROM THE CHAMPLAIN VALLEY EASTWARD. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 307 PM EST WEDNESDAY...SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE CREST OVER THE REGION THURSDAY NIGHT AND SLIDE OFF THE EASTERN SEABOARD ON FRIDAY. THIS WILL RESULT IN IDEAL CONDITIONS FOR RADIATIONAL COOLING THURSDAY NIGHT WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO UNDER CLEAR SKIES AND LIGHT WINDS. ONLY CAVEAT WILL BE SOME LOW STRATUS INDUCED BY WARMER OPEN WATERS OF LAKE CHAMPLAIN THOUGH SHOULD BE CONFINED BETWEEN THE EAST/WEST SHORELINES NORTH OF ADDISON COUNTY TO THE INTL BORDER. ON FRIDAY AS THE HIGH SLIDES EAST, WARMER SOUTHERLY RETURN FLOW WILL DEVELOP WITH INCREASING CLOUDS THROUGH THE DAY AS A CLIPPER SYSTEM APPROACHES FROM THE WEST. TEMPERATURES WILL WARM TO SLIGHTLY ABOVE NORMAL LEVELS WITH HIGHS RANGING THROUGH THE LOW TO MID 30S. MAJORITY OF THE DAY WILL BE DRY AS WELL, THOUGH CHANCES FOR PRECIP INCREASE IN THE LATE AFTERNOON TO EARLY EVENING HOURS ACROSS FAR WESTERN NEW YORK. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 307 PM EST WEDNESDAY...AFOREMENTIONED CLIPPER WILL CONTINUE TO APPROACH THE NORTH COUNTRY FRIDAY NIGHT AND PASS NORTH OF THE BORDER SATURDAY. WE`LL BE ON THE WARM SIDE OF THE SYSTEM WITH STRONG LOW/MID LEVEL WARM AIR ADVECTION ASSOCIATED WITH A 40-70KT 925-850MB JET PASSING THROUGH. THIS RESULTS IN TEMPERATURES RISING STEADILY THROUGH THE NIGHT, AND INTO THE 40S VALLEYS, 30S MOUNTAIN TOPS ON SATURDAY. IN ADDITION, INCREASING SOUTH/SOUTHWESTERLY DOWNSLOPE FLOW ASSOCIATED WITH SAID JET WILL LIKELY INHIBIT PRECIPITATION CHANCES IN THE VALLEYS FRIDAY NIGHT, WHILE ENHANCING CHANCES ALONG THE SOUTHWEST FACING SLOPES OF THE HIGHER ELEVATIONS. DURING THE DAY SATURDAY WE SHOULD SEE FAIRLY WIDESPREAD PRECIPITATION THOUGH, ESPECIALLY ACROSS THE HIGHER ELEVATIONS DURING THE AFTERNOON AS THE FLOW SHIFTS TO THE NORTHWEST AND COLD AIR ADVECTION ENSUES. AS FAR AS PTYPE GOES, ALL AREAS SHOULD START OFF AS SNOW FRIDAY NIGHT, BUT AS THE BOUNDARY LAYER WARMS ABOVE 0C WE`LL SEE A TRANSITION TO RAIN IN THE VALLEYS SATURDAY MORNING. ALOFT MEAN 925-850MB TEMPS DO REMAIN BELOW 0C SO THE HIGHEST ELEVATIONS SHOULD SEE MOSTLY SNOW WITH A FEW WET INCHES OF ACCUMULATION POSSIBLE. FOR SATURDAY NIGHT THROUGH SUNDAY, THE MEAN MID/UPPER LEVEL FLOW TURNS GENERALLY ZONAL WITH LITTLE SHORTWAVE ENERGY PASSING THROUGH SO OVERALL PRECIPITATION CHANCES WANE. WE`LL REMAIN FAIRLY CLOUDY AND MILD WITH LOWS ONLY IN THE 20S AND 30S, AND HIGHS BUMPING INTO THE MID 30S TO LOW 40S ON SUNDAY. SUNDAY NIGHT INTO MONDAY ANOTHER WEAKER SHORTWAVE TROUGH AND CLIPPER SYSTEM SWING THROUGH THE NORTHEAST, BUT IN CONTRAST TO THE SATURDAY SYSTEM, THIS ONE LOOKS TO TRACK SOUTH OF THE BTV CWA. THIS WILL PUT US ON THE COLD SIDE OF THE STORM, BUT UNFORTUNATELY LATEST TRENDS ARE FOR A FAR ENOUGH TRACK SOUTH THAT WE ARE FAR REMOVED FROM THE BEST MOISTURE AND LIFT AND WE SEE LITTLE PRECIPITATION. LOOKING OUT TOWARDS NEXT WEEK, HIGH PRESSURE BUILDS INTO THE REGION AGAIN FOR MONDAY NIGHT AND TUESDAY, BUT ONCE AGAIN MODELS ARE DEPICTING SOME SORT OF SYSTEM DEVELOPING TUESDAY ACROSS THE SOUTHEAST AND NORTHEAST ALONG THE COAST TUESDAY NIGHT INTO WEDNESDAY. IT SEEMS EVERY WEEK GUIDANCE HAS A COASTAL OUT ON DAY 6- 7, SOME OF WHICH HAS PANNED OUT, MOST HAVE NOT. IN FACT, THE ENERGY ALOFT ASSOCIATED WITH THIS SYSTEM DOESN`T EVEN COME ONTO THE PACIFIC COAST UNTIL MONDAY, SO WE LIKELY WON`T HAVE AN IDEA OF WHAT HAPPENS WITH THIS UNTIL MAYBE LATE WEEKEND. STAY TUNED. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... THROUGH 00Z FRIDAY...A COLD FRONT WILL MOVE THROUGH THE REGION OVERNIGHT WITH SOME AREAS OF MVFR/IFR IN LIGHT SNOW SHOWERS. EXPECTING MAINLY VFR CONDITIONS TO DEVELOP ACROSS THE REGION AFTER 06Z THURSDAY AS A RIDGE OF HIGH PRESSURE BUILDS SLOWLY EAST FROM THE GREAT LAKES. EXPECTING CLEAR SKIES ACROSS THE REGION FROM 18Z THURSDAY THROUGH 00Z FRIDAY. OUTLOOK 00Z FRIDAY THROUGH MONDAY... 00Z THURSDAY THROUGH 18Z FRIDAY...HIGH PRESSURE IN CONTROL WITH LIGHT WINDS, VFR CONDITIONS. 18Z FRIDAY THROUGH 00Z SUNDAY...WEAK CLIPPER SYSTEM PASSING NORTH OF THE INTL BORDER WILL BRING PERIODS OF LIGHT SNOW OR LIGHT MIXED PRECIP WITH BRIEF PERIODS OF MVFR POSSIBLE. MAY SEE S-SW WIND GUSTS REACHING 25 MPH LATE FRIDAY AFTN INTO FRIDAY NIGHT. ISOLD RAIN AND SNOW SHOWERS ARE POSSIBLE DURING THE DAY ON SATURDAY IN VALLEY LOCATIONS. 00Z SUNDAY THROUGH 00Z MONDAY...MAINLY VFR. 00Z MONDAY THROUGH 00Z TUESDAY...AREAS OF MVFR/IFR IN LIGHT SNOW. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...EVENSON/LOCONTO SHORT TERM...LAHIFF LONG TERM...LAHIFF AVIATION...EVENSON/WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
638 PM EST WED FEB 17 2016 .SYNOPSIS... A QUICK MOVING UPPER LEVEL TROUGH OF LOW PRESSURE WILL CROSS THE NORTH COUNTRY TONIGHT AND BRING SNOW SHOWERS TO THE AREA...ESPECIALLY IN THE MOUNTAINS. ANY SNOW ACCUMULATIONS WILL GENERALLY BE A DUSTING TO TWO INCHES. COLDER AND DRIER AIR FOLLOWS IN BEHIND THIS SYSTEM FOR THURSDAY WITH BELOW NORMAL TEMPERATURES EXPECTED. A WARMING TREND BEGINS FRIDAY AND CONTINUES RIGHT INTO THE WEEKEND WITH HIGH TEMPERATURES CLIMBING BACK INTO THE 40S. && .NEAR TERM /THROUGH THURSDAY/... AS OF 638 PM EST WEDNESDAY...REGIONAL COMPOSITE RADAR MOSAIC SHOWS SOME LIGHT RETURNS FROM THE CHAMPLAIN VALLEY EASTWARD, ALONG AND AHEAD OF A COLD FRONT WHICH IS NOW ADVANCING INTO WESTERN ST. LAWRENCE COUNTY. MUCH OF THIS IN THE CHAMPLAIN VALLEY IS VIRGA DUE TO DRY SUB-CLOUD AIR. FRONT WILL CONTINUE TO PUSH EASTWARD, WITH THE BEST CHANCE FOR LIGHT ACCUMULATING SNOW (AROUND 2 INCHES OR LESS) ACROSS THE MOUNTAINS. THOUGH FORECAST IS GENERALLY HOLDING UP TO THIS POINT, I`VE TRIED TO BETTER REFINE POPS WITH THIS UPDATE, ESSENTIALLY LOWERING THEM IN LOWER ELEVATIONS AND ADJUSTING UPWARD A TAD ABOVE THE 1000` ELEVATIONAL BAND THROUGH MIDNIGHT. WITH THE FRONTAL PASSAGE AND ASSOCIATED UPPER TROUGH PASSAGE, SHARP LOWER TO MID TROPOSPHERIC COLD ADVECTION AND DRYING SHOULD THEN COMMENCE THROUGH LATE EVENING ACROSS NORTHERN NEW YORK AND AROUND/AFTER MIDNIGHT ACROSS VERMONT. BY THAT POINT CLEARING SKIES AND QUICKLY FALLING TEMPERATURES IS THE RULE. HOWEVER BTV-4 AND RAP BUFKIT SOUNDINGS SHOW SHALLOW RH LAYER UNDERNEATH INVERSION AROUND MOUNTAIN SITES, SUGGESTING LINGERING CLOUDS AND PERHAPS RIMING IN THESE AREAS INTO THE AM HRS. LOW TEMPERATURES REMAIN ON TRACK...IN THE TEENS ACROSS VERMONT TO 0 TO 5 BELOW ACROSS NORTHERN NEW YORK. BEST CHANCE AT SUB-ZERO LOWS IN THE ST. LAWRENCE VALLEY GIVEN FRESH SNOWPACK AND EARLIER CLEARING. PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 307 PM FOLLOWS... UPPER TROUGH AXIS EXTENDS FROM SOUTHWEST QUEBEC PROVINCE SOUTHWESTWARD TO THE WESTERN TIP OF LAKE ONTARIO THIS AFTERNOON. FEATURE IS MOVING EASTWARD WITH NARROW BAND OF MOISTURE JUST AHEAD OF THE TROUGH AXIS. EXPECTING ABOUT A 3 TO 6 HOUR WINDOW OF SNOW/SNOW SHOWERS WITH THE TROUGH...ESPECIALLY OVER THE MOUNTAINS. LOOKING AT A DUSTING TO TWO INCHES WITH THE BEST CHANCE FOR ANY ACCUMULATING SNOW BEING IN THE MOUNTAINS. BEHIND THE TROUGH AXIS I LITTLE IN THE WAY OF ANY CLOUD COVER...THUS LOOKING AT ANY PRECIPITATION QUICKLY COMING TO AN END AFTER MIDNIGHT. SKIES WILL ALSO BE CLEARING BEHIND THE TROUGH AND WITH COLD AIR ADVECTION DEVELOPING OVERNIGHT LOWS ACROSS THE SAINT LAWRENCE VALLEY AND NORTHERN ADIRONDACKS OF NEW YORK SHOULD FALL INTO THE ZERO TO 5 BELOW RANGE WHILE LOWS REMAIN IN THE TEENS FROM THE CHAMPLAIN VALLEY EASTWARD. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 307 PM EST WEDNESDAY...SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE CREST OVER THE REGION THURSDAY NIGHT AND SLIDE OFF THE EASTERN SEABOARD ON FRIDAY. THIS WILL RESULT IN IDEAL CONDITIONS FOR RADIATIONAL COOLING THURSDAY NIGHT WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO UNDER CLEAR SKIES AND LIGHT WINDS. ONLY CAVEAT WILL BE SOME LOW STRATUS INDUCED BY WARMER OPEN WATERS OF LAKE CHAMPLAIN THOUGH SHOULD BE CONFINED BETWEEN THE EAST/WEST SHORELINES NORTH OF ADDISON COUNTY TO THE INTL BORDER. ON FRIDAY AS THE HIGH SLIDES EAST, WARMER SOUTHERLY RETURN FLOW WILL DEVELOP WITH INCREASING CLOUDS THROUGH THE DAY AS A CLIPPER SYSTEM APPROACHES FROM THE WEST. TEMPERATURES WILL WARM TO SLIGHTLY ABOVE NORMAL LEVELS WITH HIGHS RANGING THROUGH THE LOW TO MID 30S. MAJORITY OF THE DAY WILL BE DRY AS WELL, THOUGH CHANCES FOR PRECIP INCREASE IN THE LATE AFTERNOON TO EARLY EVENING HOURS ACROSS FAR WESTERN NEW YORK. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 307 PM EST WEDNESDAY...AFOREMENTIONED CLIPPER WILL CONTINUE TO APPROACH THE NORTH COUNTRY FRIDAY NIGHT AND PASS NORTH OF THE BORDER SATURDAY. WE`LL BE ON THE WARM SIDE OF THE SYSTEM WITH STRONG LOW/MID LEVEL WARM AIR ADVECTION ASSOCIATED WITH A 40-70KT 925-850MB JET PASSING THROUGH. THIS RESULTS IN TEMPERATURES RISING STEADILY THROUGH THE NIGHT, AND INTO THE 40S VALLEYS, 30S MOUNTAIN TOPS ON SATURDAY. IN ADDITION, INCREASING SOUTH/SOUTHWESTERLY DOWNSLOPE FLOW ASSOCIATED WITH SAID JET WILL LIKELY INHIBIT PRECIPITATION CHANCES IN THE VALLEYS FRIDAY NIGHT, WHILE ENHANCING CHANCES ALONG THE SOUTHWEST FACING SLOPES OF THE HIGHER ELEVATIONS. DURING THE DAY SATURDAY WE SHOULD SEE FAIRLY WIDESPREAD PRECIPITATION THOUGH, ESPECIALLY ACROSS THE HIGHER ELEVATIONS DURING THE AFTERNOON AS THE FLOW SHIFTS TO THE NORTHWEST AND COLD AIR ADVECTION ENSUES. AS FAR AS PTYPE GOES, ALL AREAS SHOULD START OFF AS SNOW FRIDAY NIGHT, BUT AS THE BOUNDARY LAYER WARMS ABOVE 0C WE`LL SEE A TRANSITION TO RAIN IN THE VALLEYS SATURDAY MORNING. ALOFT MEAN 925-850MB TEMPS DO REMAIN BELOW 0C SO THE HIGHEST ELEVATIONS SHOULD SEE MOSTLY SNOW WITH A FEW WET INCHES OF ACCUMULATION POSSIBLE. FOR SATURDAY NIGHT THROUGH SUNDAY, THE MEAN MID/UPPER LEVEL FLOW TURNS GENERALLY ZONAL WITH LITTLE SHORTWAVE ENERGY PASSING THROUGH SO OVERALL PRECIPITATION CHANCES WANE. WE`LL REMAIN FAIRLY CLOUDY AND MILD WITH LOWS ONLY IN THE 20S AND 30S, AND HIGHS BUMPING INTO THE MID 30S TO LOW 40S ON SUNDAY. SUNDAY NIGHT INTO MONDAY ANOTHER WEAKER SHORTWAVE TROUGH AND CLIPPER SYSTEM SWING THROUGH THE NORTHEAST, BUT IN CONTRAST TO THE SATURDAY SYSTEM, THIS ONE LOOKS TO TRACK SOUTH OF THE BTV CWA. THIS WILL PUT US ON THE COLD SIDE OF THE STORM, BUT UNFORTUNATELY LATEST TRENDS ARE FOR A FAR ENOUGH TRACK SOUTH THAT WE ARE FAR REMOVED FROM THE BEST MOISTURE AND LIFT AND WE SEE LITTLE PRECIPITATION. LOOKING OUT TOWARDS NEXT WEEK, HIGH PRESSURE BUILDS INTO THE REGION AGAIN FOR MONDAY NIGHT AND TUESDAY, BUT ONCE AGAIN MODELS ARE DEPICTING SOME SORT OF SYSTEM DEVELOPING TUESDAY ACROSS THE SOUTHEAST AND NORTHEAST ALONG THE COAST TUESDAY NIGHT INTO WEDNESDAY. IT SEEMS EVERY WEEK GUIDANCE HAS A COASTAL OUT ON DAY 6- 7, SOME OF WHICH HAS PANNED OUT, MOST HAVE NOT. IN FACT, THE ENERGY ALOFT ASSOCIATED WITH THIS SYSTEM DOESN`T EVEN COME ONTO THE PACIFIC COAST UNTIL MONDAY, SO WE LIKELY WON`T HAVE AN IDEA OF WHAT HAPPENS WITH THIS UNTIL MAYBE LATE WEEKEND. STAY TUNED. && .AVIATION /23Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...VFR CONDITIONS WILL BEGIN AT THE START OF THE PERIOD THEN TREND DOWN INTO THE MVFR/IFR CATEGORY BETWEEN 21Z AND 06Z WITH RESPECT TO CEILINGS AS AN UPPER LEVEL TROUGH OF LOW PRESSURE MOVES INTO THE REGION. THE BEST CHANCE FOR IFR CEILINGS WILL BE AT KSLK. AFTER 06Z CEILINGS WILL IMPROVE BACK INTO THE MVFR AND VFR CATEGORIES. WITH THE LOWERING CEILINGS LIGHT SNOW SHOWERS ARE EXPECTED AND VISIBILITIES WILL GENERALLY BE IN THE VFR AND MVFR CATEGORIES BETWEEN 21Z AND 06Z BEFORE SNOW ENDS AND VISIBILITIES RETURN TO VFR FOR THE REMAINDER OF THE PERIOD. AGAIN BEST CHANCE FOR A PERIOD OF IFR VISIBILITIES WILL BE AT KSLK. WINDS WILL BE VARIABLE AT THE START OF THE PERIOD...THEN SHIFT TO THE NORTHWEST BETWEEN 21Z AND 03Z BEFORE BACKING TO THE WEST AND DECREASING IN SPEEDS BY 12Z. OUTLOOK 18Z THURSDAY THROUGH SUNDAY... 18Z THURSDAY THROUGH 18Z FRIDAY...HIGH PRESSURE IN CONTROL WITH LIGHT WINDS, VFR CONDITIONS. 18Z FRIDAY THROUGH 00Z SUNDAY...WEAK CLIPPER SYSTEM PASSING NORTH OF THE INTL BORDER WILL BRING PERIODS OF LIGHT SNOW OR LIGHT MIXED PRECIP WITH BRIEF PERIODS OF MVFR POSSIBLE. MAY SEE S-SW WIND GUSTS REACHING 25 MPH LATE FRIDAY AFTN INTO FRIDAY NIGHT. ISOLD RAIN AND SNOW SHOWERS ARE POSSIBLE DURING THE DAY ON SATURDAY IN VALLEY LOCATIONS. 00Z SUNDAY THROUGH 00Z MONDAY...MAINLY VFR. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...EVENSON/LOCONTO SHORT TERM...LAHIFF LONG TERM...LAHIFF AVIATION...BANACOS/EVENSON
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1147 PM EST MON FEB 15 2016 .SYNOPSIS... A DEEP STORM SYSTEM WILL MOVE INTO THE REGION TONIGHT AND TUESDAY WITH HEAVY SNOW DEVELOPING ACROSS WESTERN NEW YORK AND SNOW CHANGING TO RAIN ACROSS CENTRAL NEW YORK. SIGNIFICANT ICE ACCUMULATIONS ARE POSSIBLE ALONG THE SAINT LAWRENCE RIVER VALLEY IN NORTHERN JEFFERSON COUNTY ON TUESDAY. THIS WILL ALL CHANGE BACK TO SNOW SHOWERS TUESDAY EVENING BEFORE ENDING. BEYOND THIS STORM SYSTEM... A FEW LIGHT SNOW SHOWERS ARE POSSIBLE WEDNESDAY WITH COLDER AIR LINGERING THROUGH THE END OF THE WEEK BEFORE MORE MODERATE TEMPERATURES BY THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY NIGHT/... THE LATEST REGIONAL RADAR IMAGERY CONTINUES TO SHOW SNOW FILLING IN ACROSS MUCH OF THE FORECAST AREA. RADAR RETURNS ARE MATCHING UP NICELY WITH HRRR GUIDANCE IN SHOWING A PERSISTENT AREA OF LOWER RETURNS ACROSS THE NIAGARA FRONTIER WHERE LOWER LEVEL DRY AIR REMAINS STUBBORNLY ENTRENCHED. NONETHELESS...GIVEN CURRENT RADAR TRENDS...REMAIN CONFIDENT IN THE HRRR WHICH ALSO SUPPORTS CURRENT FORECAST THAT GENERATES A BAND OF HEAVY SNOW ALONG A LINE RUNNING ROUGHLY FROM THE WESTERN SOUTHERN TIER ACROSS THE GENESEE VALLEY TO THE VICINITY OF WATERTOWN. SNOWFALL IS STILL EXPECTED TO INCREASE IN INTENSITY OVERNIGHT WITH PEAK SNOWFALL RATES OCCURRING TUESDAY MORNING AS A ZONE OF STRONG DEFORMATION PIVOTS ACROSS THE AREA BEFORE TAPERING OFF FROM WEST TO EAST BY TUESDAY AFTERNOON AS THE RESPONSIBLE SURFACE LOW BEGINS TO PULL AWAY TO THE NORTHEAST. THE EXPECTED TRACK OF THE SURFACE LOW WILL KEEP WESTERN NY ON THE COLD SIDE OF THE STRONG BAROCLINIC ZONE... THUS STILL EXPECT MUCH OF WESTERN NY TO SEE 6 TO 12 INCHES OF SNOW... WITH A NARROW CORRIDOR OF 12 TO 18 INCHES LIKELY IN THE VICINITY OF THE AFOREMENTIONED LINE BETWEEN BUFFALO AND ROCHESTER WHERE THE BEST DEFORMATION AND BANDED SNOW DEVELOPS. THE BULK OF THE SNOW WILL IMPACT WESTERN NY BETWEEN BETWEEN 3AM AND EARLY AFTERNOON TUESDAY... WITH THE POTENTIAL FOR HEAVY SNOWFALL RATES OF 1 TO 2 INCHES AN HOUR DEVELOPING BETWEEN ABOUT 5AM AND NOON IN THE FAVORED AXIS OF HEAVIEST SNOWFALL BETWEEN BUFFALO AND ROCHESTER. NEAR ROCHESTER AND ALONG THE GENESEE VALLEY... SIMILAR TO WESTERN NY SNOW WILL DEVELOP OVERNIGHT AND BECOME HEAVIEST TOWARD SUNRISE TUESDAY. HOWEVER... THERE WILL BE A SHARP TRANSITION ZONE BETWEEN SNOW TO THE WEST AND RAIN TO THE EAST THAT DEVELOPS NEAR THE GENESEE VALLEY DURING THE DAY TUESDAY. SNOW ACCUMULATIONS FOR LOCATIONS ALONG THIS TRANSITION ZONE WILL BE HEAVILY DEPENDENT ON THE TRACK OF THE SURFACE LOW... WITH LOCATIONS JUST WEST OF THE TRANSITION ZONE LIKELY THE SEE SOME OF THE HEAVIEST SNOWFALL AMOUNTS... WHILE LOCATIONS JUST TO THE EAST WILL SEE MUCH LOWER AMOUNTS WITH A PERIOD OF RAIN DURING THE DAY TUESDAY. PRESENTLY... ROCHESTER LOOKS TO BE JUST ON THE COLD SIDE OF THIS AXIS... BUT WOULD NOT RULE OUT A FEW HOURS WHERE PRECIPITATION CHANGES TO A WINTRY MIX DURING THE DAY. SNOWFALL AMOUNTS WILL RANGE FROM 9 TO 18 INCHES TOWARD THE NORTHWEST CORNERS OF THESE COUNTIES WITH LOWER AMOUNTS OF 5 TO 7 INCHES TOWARD THE SOUTHEAST CORNERS OF THESE COUNTIES. FROM WAYNE COUNTY EAST TO LEWIS COUNTY (EXCLUDING JEFFERSON COUNTY)... A BAND OF MODERATE TO HEAVY SNOW WILL TRACK NORTHWARD ACROSS THIS AREA OVERNIGHT BEFORE MUCH WARMER AIR SURGES INTO THE AREA BY TUESDAY. THIS WILL CAUSE SNOW TO QUICKLY TRANSITION THROUGH A WINTRY MIX TO ALL RAIN THROUGH MUCH OF THE DAY. THESE LOCATIONS CAN EXPECT 4 TO 7 INCHES OF SNOW TONIGHT BEFORE JUST SOME SLUSHY LIGHT ACCUMULATIONS ON TUESDAY BEFORE PRECIPITATION CHANGES TO ALL RAIN. RAIN MAY ACTUALLY BE HEAVY AT TIMES TUESDAY WITH RAINFALL AMOUNTS OF AN INCH OR TWO ON TUESDAY. RAIN WILL THEN CHANGE BACK TO SNOW TUESDAY EVENING WITH A BURST OF MODERATE TO HEAVY SNOW PRODUCING A QUICK 2 TO 5 INCHES AS THE DEFORMATION AXIS ON THE BACK SIDE OF THE SURFACE LOW TRACK ACROSS THE AREA. JEFFERSON COUNTY...JEFFERSON COUNTY WILL EVOLVE SIMILARLY TO LOCATIONS SOUTH OF THERE (SEE SECTION ABOVE)... HOWEVER THE IMPORTANT DIFFERENCE IS THE POTENTIAL FOR SIGNIFICANT ICE ACCUMULATIONS OVER NORTHERN PORTIONS OF THE COUNTY ALONG THE SAINT LAWRENCE RIVER VALLEY. WITH MODELS MORE CONSISTENT ON THE TRACK OF THE SURFACE LOW... IT REMAINS VERY LIKELY THAT NORTHEAST WINDS WILL FUNNEL COLDER AIR AT THE SURFACE DOWN THE VALLEY. THE STRONG SURGE OF WARM ADVECTION AHEAD OF THE SURFACE LOW RIDING OVER THE SUB- FREEZING SURFACE TEMPERATURES WILL PRODUCE SIGNIFICANT FREEZING RAIN ACCUMULATIONS ALONG THE VALLEY. SURFACE TEMPERATURES ARE MOST LIKELY TO REMAIN BELOW FREEZING JUST NORTH OF WATERTOWN ALONG THE RIVER VALLEY... WHICH WILL ALLOW FOR A HALF INCH TO AN INCH OF ICE ACCUMULATION DURING THE DAY TUESDAY. THIS COULD BRING DOWN NUMEROUS TREE LIMBS AND POWER LINES RESULTING IN WIDESPREAD POWER OUTAGES ALONG THE VALLEY. IN ADDITION... THE THREAT OF HEAVY RAINFALL ACROSS CENTRAL AND NORTH CENTRAL NEW YORK HAS PROMPTED A FLOOD WATCH. STORM TOTAL QPF AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED... WITH AROUND AN INCH AND HALF TO TWO INCHES OF THAT FALLING AS RAIN. EXCESSIVE RUNOFF FROM HEAVY RAIN AND SOME SNOW MELT MAY RESULT IN FLOODING IN LOW LYING AND POOR DRAINAGE AREAS. SMALL CREEKS MAY ALSO SEE SIGNIFICANT RISES. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... ON WEDNESDAY A RELATIVELY WEAK MID LEVEL TROUGH AND SURFACE COLD FRONT WILL CROSS THE LOWER LAKES. A PERIOD OF LARGE SCALE ASCENT IN THE DPVA REGIME AHEAD OF THE TROUGH MAY PROVIDE ENOUGH FORCING FOR A FEW SCATTERED SNOW SHOWERS. A MODEST AMOUNT OF LAKE MOISTURE AND ALSO UPSLOPE FLOW WILL BRING A HIGHER LIKELIHOOD OF SOME LIGHT SNOW EAST OF LAKES ERIE AND ONTARIO WHERE SOME VERY MINOR ACCUMULATIONS ARE POSSIBLE WEDNESDAY AND WEDNESDAY EVENING. EXPECT HIGHS NEAR THE MID FEBRUARY AVERAGES WITH LOW 30S ON THE LAKE PLAINS AND UPPER 20S HIGHER TERRAIN. LATER WEDNESDAY NIGHT INTO EARLY THURSDAY BOUNDARY LAYER FLOW WILL BECOME NORTHWEST. THIS MAY PRODUCE A BRIEF PERIOD OF SCATTERED LAKE EFFECT SNOW SHOWERS SOUTHEAST OF THE LAKES...BUT MARGINAL INSTABILITY AND A DRY AIRMASS WILL GREATLY LIMIT INTENSITY AND COVERAGE. EXPECT ANY ACCUMULATION TO BE AN INCH OR LESS FROM ROCHESTER TO OSWEGO COUNTY AND ACROSS THE WESTERN SOUTHERN TIER. A COLDER AIRMASS WILL BUILD INTO THE REGION WEDNESDAY NIGHT WITH LOW TEMPS BY DAYBREAK THURSDAY IN THE LOWER TEENS ON THE LAKE PLAINS AND SINGLE DIGITS INLAND. THURSDAY HIGH PRESSURE BUILDS OVER THE LOWER LAKES. ANY LINGERING LAKE EFFECT SNOW SHOWERS SOUTHEAST OF LAKE ONTARIO WILL END EARLY IN THE DAY. STRONG SUBSIDENCE AND DRYING WILL BRING A GOOD DEAL OF SUNSHINE. TEMPERATURES WILL REMAIN CHILLY WITH HIGHS ONLY IN THE UPPER TEENS TO LOWER 20S IN MOST AREAS. HIGH PRESSURE DRIFTS EAST TO NEW ENGLAND THURSDAY NIGHT WITH SUBSIDENCE AND DRY AIR HOLDING OFF ANY PRECIP FROM THE NEXT SYSTEM UNTIL FRIDAY MORNING. && .LONG TERM /FRIDAY THROUGH MONDAY/... FRIDAY THROUGH SATURDAY A STRONG CLIPPER SYSTEM WILL MOVE FROM LAKE SUPERIOR ACROSS SOUTHERN QUEBEC. DEEP SOUTHWESTERLY FLOW AHEAD OF THIS SYSTEM WILL TRANSPORT WARMER AIR INTO OUR REGION WITH HIGHS IN THE LOWER 40S FRIDAY AND MID 40S SATURDAY FOR MOST OF THE AREA. THIS WILL ALLOW MOST OF THE PRECIP TO FALL AS LIGHT RAIN. THE NORTH COUNTRY WILL STAY COOLER...ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE TUG HILL AND WESTERN ADIRONDACKS. THIS MAY ALLOW PRECIP TYPE TO REMAIN MORE WET SNOW WITH HIGHS IN THE MID TO UPPER 30S INLAND FROM THE LAKE. BY SUNDAY NIGHT AND MONDAY MODEL GUIDANCE BEGINS TO DIVERGE. THE GFS BRINGS A COLD FRONT SOUTH ACROSS THE LAKES WITH A FEW SNOW SHOWERS AND COLDER TEMPERATURES...WHILE THE ECMWF DEVELOPS A WEAK SOUTHERN STREAM WAVE WITH SOME LIGHT SNOW ON MONDAY. EITHER SCENARIO WILL BRING A CHANCE OF SOME LIGHT SNOW WITH TEMPERATURES RETURNING CLOSER TO AVERAGE. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... LATEST RADAR TRENDS INDICATE THAT SNOW IS BEGINNING TO FILL IN ACROSS MUCH OF CENTRAL NY AND THE SOUTHERN TIER WHERE IFR CONDITIONS HAVE DEVELOPED. MVFR CONDITIONS REMAIN ACROSS THE NIAGARA FRONTIER AT THIS TIME DUE TO THE CONTINUED PRESENCE OF DRY AIR IN THE LOW LEVELS. NONETHELESS...LIGHT SNOW IS BEGINNING TO MOVE INTO THE AREA AND IS EXPECTED TO PICK UP IN INTENSITY AFTER 06Z AS A STRONG DEFORMATION ZONE SETS UP INVOF THE GENESEE VALLEY. WITH THIS EXPECT CONDITIONS TO DETERIORATE TO IFR EVEN ACROSS THE NIAGARA FRONTIER. AS THE MAIN SNOWBAND COALESCES ALONG A LINE ROUGHLY FROM KJHW TO KFZY...EXPECT LIFR CONDITIONS IN +SN WITHIN THIS BAND WITH IFR CONDITIONS BRACKETING MUCH OF WESTERN NY. TO THE SOUTHEAST OF THIS LINE...EXPECT MIXED PRECIP WITH SLEET/FREEZING RAIN. THE AFOREMENTIONED LINE WILL PIVOT ACROSS THE FINGER LAKES AND THE VICINITY OF KROC THROUGH THE MORNING HOURS ON TUESDAY WITH MIXED PRECIP MOVING INTO THE NORTH COUNTRY INCLUDING KART BEFORE CHANGING OVER TO RAIN LATER IN THE DAY. BY THE END OF THE PERIOD PRECIP SHOULD CHANGE BACK TO SNOW AS THE LOW MOVES OFF TO THE NORTHEAST AND DRAGS THE COLDER AIR AND SNOW ASSOCIATED WITH THE DEFORMATION ZONE BACK ACROSS THE AREA. MEANWHILE...MODERATE TO HEAVY SNOW WILL CONTINUE ACROSS WRN NY BEFORE TAPERING OFF LATER IN THE DAY AS THE AFOREMENTIONED DEFORMATION ZONE MOVES OFF TO THE EAST. IFR CONDITIONS WILL GRADUALLY IMPROVE TO MVFR...AND EVENTUALLY VFR AS THIS SNOW MOVES OFF TO THE EAST. OUTLOOK... TUESDAY...WIDESPREAD IFR WITH SNOW IN WESTERN NEW YORK AND SNOW CHANGING TO RAIN IN CENTRAL NEW YORK. WEDNESDAY...MVFR WITH A CHANCE OF SNOW SHOWERS. THURSDAY...MAINLY VFR. FRIDAY AND SATURDAY...MVFR WITH A CHANCE OF RAIN AND SNOW. && .MARINE... A STRONG LOW PRESSURE SYSTEM WILL MOVE THROUGH NY STATE ON TUESDAY... WITH NORTHEAST WINDS BECOMING NORTHWEST LATER IN THE DAY AS THE LOW TRACKS TOWARD QUEBEC. HAVE ISSUED SMALL CRAFT ADVISORIES FOR WINDS AND WAVES ALONG THE SOUTHERN LAKE ONTARIO SHORELINE TUESDAY THROUGH TUESDAY NIGHT. && .HYDROLOGY... A VERY COMPLEX HYDRO EVENT WILL UNFOLD ON TUESDAY ACROSS THE NORTHERN FINGER LAKES AND EASTERN LAKE ONTARIO REGION. SNOW WILL OVERSPREAD THE AREA OVERNIGHT...THEN CHANGE TO RAIN EARLY TUESDAY BEFORE GOING BACK TO SNOW BY EARLY EVENING. THE RAIN WILL BE HEAVY DURING THE DAY TUESDAY WITH RAINFALL AMOUNTS OF 1.5 TO 2 INCHES POSSIBLE. THE HEAVIEST RAINFALL IS LIKELY TO FOCUS IN A CORRIDOR ALONG AND JUST WEST OF INTERSTATE 81. EXCESSIVE RUNOFF FROM THE RAINFALL PLUS SOME SNOW MELT MAY RESULT IN FLOODING IN LOW LYING AND POOR DRAINAGE AREAS AND POSSIBLY SMALL CREEKS. THE NEW SNOW ON THE GROUND WILL INITIALLY ABSORB SOME OF THE RAINFALL...BUT SHOULD THEN RELEASE WATER FOR AT LEAST SEVERAL HOURS IN THE MIDDLE OF THE DAY WHEN TEMPERATURES ARE WARMEST. WITH THE ABOVE IN MIND...WE HAVE ISSUED A FLOOD WATCH FOR ONTARIO... WAYNE...NORTHERN CAYUGA...OSWEGO...JEFFERSON...AND LEWIS COUNTIES. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...FLOOD WATCH FROM 8 AM EST TUESDAY THROUGH TUESDAY EVENING FOR NYZ004>008-014. WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR NYZ004>008. WINTER STORM WARNING UNTIL 7 PM EST TUESDAY FOR NYZ001>003- 010>014-019>021-085. MARINE...SMALL CRAFT ADVISORY FROM 10 AM TUESDAY TO 7 AM EST WEDNESDAY FOR LOZ042>044. && $$ SYNOPSIS...CHURCH NEAR TERM...CHURCH/WOOD SHORT TERM...HITCHCOCK LONG TERM...HITCHCOCK AVIATION...WOOD MARINE...CHURCH HYDROLOGY...HITCHCOCK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1202 AM EST TUE FEB 16 2016 .SYNOPSIS... A COASTAL WARM FRONT WILL ADVANCE INLAND INTO EASTERN SECTIONS OF NORTH CAROLINA TONIGHT AS THE LOW PRESSURE TRACKS THROUGH THE REGION. THE COLD FRONT WILL MOVE EAST ACROSS OUR REGION LATER TODAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 945 PM MONDAY... ...WINTER STORM WARNING FOR THE TRIAD EAST TO PERSON COUNTY EXTENDED THROUGH 700 AM TUESDAY MORNING... ...WINTER WEATHER ADVISORY FOR DAVIDSON AND RANDOLPH COUNTIES EXTENDED THROUGH MIDNIGHT TONIGHT... WE CONTINUE TO SEE SHOWERS PROPAGATING NORTH ACROSS THE STUBBORN CAD AIRMASS...WITH SOME WEAK ELEVATED INSTABILITY ANALYZED ON THE SPC MESOANALYSIS ACROSS THE PIEDMONT. THE SLOW EROSION OF THE CAD AIRMASS AND SUB-FREEZING TEMPS IS PROBLEMATIC...WITH THESE SHOWERS EXPECTED TO CONTINUE AS THE LOW LEVEL JET SHIFTS EAST WITH THE CONVECTIVE LINE CROSSING THE SOUTHEAST STATES. EVEN THE THE COLDEST GUIDANCE...THE HRRR/WRFNMM...WHICH MAY STILL WARM THE NORTHWEST PIEDMONT TO QUICKLY...SHOWS TEMPS GETTING ABOVE FREEZING IN THE CURRENT WINTER WX ADVISORY AREA BY 10PM AND THE WINTER STORM AREA BY 2AM. IT DOESN`T LOOK LIKE THE ENTIRE ADVISORY AREA WILL BE ABOVE FREEZING BY 10PM...BUT GIVEN THAT THE BULK OF THE SHOWERS IN THE NEXT COUPLE OF HOURS SHOULD BE OVER THE WESTERN PIEDMONT...WE WILL LET THE ADVISORY EXPIRE AT 10PM. THE WARNING AND ADDITIONAL ADVISORY AREA FOR RANDOLPH AND DAVIDSON COUNTIES WILL CONTINUE AND THE ADVISORY WILL BE REEVALUATED AT MIDNIGHT. WE ARE A CONCERNED ABOUT ICE ACCRUAL IN FORSYTH COUNTY (TEMPS ARE STILL IN THE UPPER 20S) WHERE THE CAD AIRMASS MAY NOT COMPLETELY ERODE UNTIL THE CONVECTIVE LINE SWEEPS THROUGH...AND GIVEN HRRR HOURLY PRECIP AMOUNTS OF .04 TO .08 INCHES IN THE SHOWERS... ANOTHER TENTH OR TWO OF ICE ISN`T COMPLETELY OUR OF THE QUESTION IN THE FAR NORTHWESTERN PORTIONS OF THE COUNTY. REGARDING SOME OF THE FOG IN THE PIEDMONT...THIS LOOKS TO BE TRANSIENT WITH THE WEDGE FRONT AND WILL LIKELY SPREAD WEST IN THE NEXT FEW HOURS AND THEN BE ERODED WITH THE STRENGTHENING SOUTHEASTERLY FLOW AHEAD OF THE CONVECTIVE LINE. A DENSE FOG ADVISORY DOESN`T APPEAR TO BE NEEDED AT THE MOMENT. AND FOR THE CONVECTIVE LINE...THE TIMING APPEARS TO BE UNCHANGED...ARRIVING IN THE WESTERN PIEDMONT CLOSE AROUND 4AM...THOUGH WARM ADVECTION IS LIKELY TO SUPPORT SOME PREFRONTAL SHOWERS IMMEDIATELY AHEAD OF THE LINE AS WELL. SURFACE BASED INSTABILITY WILL BE LIMITED BY THE SLOW INLAND PROGRESSION OF THE COASTAL FRONT AND WARM SECTOR...AND SO THE COASTAL PLAIN STILL APPEARS TO BE FAVORED FOR THE STRONGEST CONVECTIVE WIND GUSTS...WHERE A FEW HUNDRED J/KG OF CAPE SHOULD MATERIALIZE. MODELS STILL SHOW THE PRIMARY LOW TRACK THROUGH THE PIEDMONT...BUT IT SEEMS THIS STILL HAS SOME WESTWARD ERROR AND ANY TORNADO THREAT IS ALSO MOST LIKELY NEAR THE COAST. STILL...HRRR SOUNDINGS SUGGEST THE EROSION OF THE NEAR SURFACE STABLE LAYER AND ADDED DOWNWARD MOMENTUM TRANSPORT WITHIN THE SHOWERS AND ISOLATED THUNDERSTORMS COULD STILL LEAD TO SOME 40-50KT WIND GUSTS...PRIMARILY EAST OF HIGHWAY 1. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... AS OF 255 PM MONDAY... PRECIP...IN THE FORM OF RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL BE ONGOING TO START THE DAY ON TUESDAY. THE LEADING EDGE OF THE LINE OF SHOWERS/STORMS IS EXPECTED TO BE QUICKLY RACING FROM THE TRIAD TO THE TRIANGLE BY 12Z AND AND THEN OFFSHORE BY EARLY AFTERNOON. INSTABILITY WILL BE VERY WEAK (BUT NON-ZERO) DURING THE TIME...WITH ONLY A COUPLE HUNDRED J/KG EXPECTED ACROSS THE EASTERN HALF OF THE FORECAST AREA. NEVERTHELESS...THE SPC HAS PLACED THIS AREA IN A MARGINAL RISK GIVEN THE STRONG FORCING AHEAD OF AN APPROACHING ROBUST SHORT WAVE TROUGH. IN ADDITION...AN INTENSE LOW LEVEL JET (60- 70 KNOTS)...WILL BE PRESENT...BUT RAPIDLY SHIFTING OFFSHORE THROUGH 18Z. THEREFORE...DAMAGING WINDS WILL BE POSSIBLE WITH ANY OF THE STRONGER STORMS. REGARDLESS...WINDS WILL BE RATHER GUSTY...EVEN OUTSIDE OF ANY CONVECTION...WITH GUSTS UP TO 30 MPH POSSIBLE. HIGHS SHOULD BE IN THE MID/UPPER 50S TO LOWER 60S. ANOTHER SHORT WAVE TROUGH IS EXPECTED TO SHIFT THROUGH THE REGION TUESDAY NIGHT. THERE WILL BE LIMITED MOISTURE TO WORK WITH BY THIS TIME AND THEREFORE AM NOT EXPECTING TOO MUCH IN THE WAY OF PRECIP OVERNIGHT...JUST AN INCREASE IN SOME CLOUDS. HOWEVER...GIVEN THE STRENGTH OF THIS WAVE...A SLIGHT CHANCE OF SOME LIGHT RAIN WILL BE POSSIBLE...MAINLY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA. OVERNIGHT LOWS SHOULD GENERALLY BE IN THE MID TO UPPER 30S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... AS OF 310 PM MONDAY... UPPER LEVEL TROUGH WILL PERSIST ALONG THE EASTERN SEABOARD WEDNESDAY- THURSDAY...MAINTAINING A CYCLONIC FLOW OVER CENTRAL NC. A SERIES OF UPPER DISTURBANCES ROUNDING THE BASE OF THE TROUGH WILL CAUSE PERIODS OF CLOUDINESS BUT LITTLE IN THE WAY OF PRECIP AS THE MOISTURE...WHILE ENOUGH TO PRODUCE CLOUDS...NOT ENOUGH TO GENERATE PRECIPITATION. TEMPERATURES WILL AVERAGE CLOSE TO NORMAL WITH AFTERNOON TEMPS GENERALLY 50-55 WITH OVERNIGHT LOWS A COUPLE OF DEGREES BELOW FREEZING. THE TROUGH WEAKENS AND LIFTS NEWD BY THE END OF THE WEEK...PERMITTING A PERIOD OF S/W RIDGING TO OCCUR. THIS WILL INITIATE A WARMING PERIOD WITH TEMPERATURES 5-8 DEGREES ABOVE NORMAL BY SATURDAY/SUNDAY. A S/W IN THE NORTHERN BRANCH OF THE JET STREAM WILL CROSS NORTH OF OUR REGION...DRAGGING A MOISTURE STARVED FRONT ACROSS THE AREA LATE SATURDAY-SATURDAY NIGHT. AIR MASS BEHIND THE FRONT OF PACIFIC ORIGIN SO NOT EXPECTING A BLAST OF COLD AIR. MODELS DIVERGE WITH THE STRENGTH OF THE S/W EXITING THE CENTRAL- NORTHERN PLAINS LATE SUNDAY INTO MONDAY WITH THE 00Z ECMWF DEPICTING MORE AMPLITUDE THAN THE 12Z GFS. FOR NOW...WILL INCREASE CLOUDINESS MONDAY BUT KEEP POPS AOB 20%. && .AVIATION /05Z TUESDAY THROUGH SATURDAY/... AS OF 555 PM MONDAY... DANGEROUS AVIATION CONDITIONS THROUGH TONIGHT... (V)LIFR CONDITIONS; PERIODS OF PRECIPITATION --ALL OCCASIONALLY MODERATE TO HEAVY AND SOME WINTRY FOR THE NEXT SEVERAL HOURS-- AND DEVELOPING LOW LEVEL WIND SHEAR CONDITIONS...WILL AFFECT CENTRAL NC TAF SITES. SCATTERED TO NUMEROUS SHOWERS...INCLUDING MODERATE TO HEAVY FREEZING RAIN ONES OVER TRIAD TAF SITES WHERE TEMPERATURES WILL REMAIN IN THE UPPER 20S TO AROUND 30 DEGREES THROUGH AROUND MIDNIGHT...WILL TRANSITION TO LIQUID ONES AS TEMPERATURES RISE ABOVE FREEZING SHORTLY THEREAFTER. MEANWHILE TO THE EAST...THE TEMPERATURE WILL BREACH FREEZING AND RESULT IN FOLLOWING ALL LIQUID SHOWERY PRECIPITATION FROM SOUTHEAST TO NORTHWEST FROM RWI TO RDU IN THE NEXT FEW HOURS...WHILE THE TEMPERATURE HAS ALREADY RISEN ABOVE FREEZING AT FAY. AN EXPANSION OF LOCALLY DENSE FOG MAY ALSO ACCOMPANY THE ONGOING LIFR CEILINGS TONIGHT...AS A WARM FRONT RETREATS ACROSS THE AREA. THE APPROACH OF A POWERFUL UPPER LEVEL TROUGH AND PASSAGE OF AN ASSOCIATED SURFACE LOW WILL RESULT IN THE EASTWARD MIGRATION OF A BAND OF HEAVY RAIN AND ISOLATED THUNDERSTORMS ACROSS CENTRAL NC LATE TONIGHT AND EARLY TUESDAY. WINDS WESTERLY FLOW AND VFR CONDITIONS WILL DEVELOP IN THE WAKE OF THE BAND OF SHOWERS BY EARLY TUE AFTERNOON. HOWEVER...A FAST-MOVING UPPER LEVEL DISTURBANCE...ON THE HEELS OF THE LEAD ONE TONIGHT...WILL SWEEP EAST ACROSS THE MIDDLE ATLANTIC STATES LATE TUE-EARLY TUE NIGHT. LOW VFR CEILINGS AND LIGHT RAIN MAY RESULT...PARTICULARLY ACROSS NORTHERN TAF SITES. && .RAH WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR NCZ007>010-021>026-038>041-073>076-083-084. DENSE FOG ADVISORY UNTIL 3 AM EST EARLY THIS MORNING FOR NCZ011-027-028-042-043-077-085-086-088. WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR NCZ007- 021>024. && $$ SYNOPSIS...BADGETT NEAR TERM...SMITH SHORT TERM...KRD LONG TERM...WSS AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1127 PM EST MON FEB 15 2016 .SYNOPSIS... A COASTAL WARM FRONT WILL ADVANCE INLAND INTO EASTERN SECTIONS OF NORTH CAROLINA TONIGHT AS THE LOW PRESSURE TRACKS THROUGH THE REGION. THE COLD FRONT WILL MOVE EAST ACROSS OUR REGION TUESDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 945 PM MONDAY... ...WINTER STORM WARNING FOR THE TRIAD EAST TO PERSON COUNTY EXTENDED THROUGH 700 AM TUESDAY MORNING... ...WINTER WEATHER ADVISORY FOR DAVIDSON AND RANDOLPH COUNTIES EXTENDED THROUGH MIDNIGHT TONIGHT... WE CONTINUE TO SEE SHOWERS PROPAGATING NORTH ACROSS THE STUBBORN CAD AIRMASS...WITH SOME WEAK ELEVATED INSTABILITY ANALYZED ON THE SPC MESOANALYSIS ACROSS THE PIEDMONT. THE SLOW EROSION OF THE CAD AIRMASS AND SUB-FREEZING TEMPS IS PROBLEMATIC...WITH THESE SHOWERS EXPECTED TO CONTINUE AS THE LOW LEVEL JET SHIFTS EAST WITH THE CONVECTIVE LINE CROSSING THE SOUTHEAST STATES. EVEN THE THE COLDEST GUIDANCE...THE HRRR/WRFNMM...WHICH MAY STILL WARM THE NORTHWEST PIEDMONT TO QUICKLY...SHOWS TEMPS GETTING ABOVE FREEZING IN THE CURRENT WINTER WX ADVISORY AREA BY 10PM AND THE WINTER STORM AREA BY 2AM. IT DOESN`T LOOK LIKE THE ENTIRE ADVISORY AREA WILL BE ABOVE FREEZING BY 10PM...BUT GIVEN THAT THE BULK OF THE SHOWERS IN THE NEXT COUPLE OF HOURS SHOULD BE OVER THE WESTERN PIEDMONT...WE WILL LET THE ADVISORY EXPIRE AT 10PM. THE WARNING AND ADDITIONAL ADVISORY AREA FOR RANDOLPH AND DAVIDSON COUNTIES WILL CONTINUE AND THE ADVISORY WILL BE REEVALUATED AT MIDNIGHT. WE ARE A CONCERNED ABOUT ICE ACCRUAL IN FORSYTH COUNTY (TEMPS ARE STILL IN THE UPPER 20S) WHERE THE CAD AIRMASS MAY NOT COMPLETELY ERODE UNTIL THE CONVECTIVE LINE SWEEPS THROUGH...AND GIVEN HRRR HOURLY PRECIP AMOUNTS OF .04 TO .08 INCHES IN THE SHOWERS... ANOTHER TENTH OR TWO OF ICE ISN`T COMPLETELY OUR OF THE QUESTION IN THE FAR NORTHWESTERN PORTIONS OF THE COUNTY. REGARDING SOME OF THE FOG IN THE PIEDMONT...THIS LOOKS TO BE TRANSIENT WITH THE WEDGE FRONT AND WILL LIKELY SPREAD WEST IN THE NEXT FEW HOURS AND THEN BE ERODED WITH THE STRENGTHENING SOUTHEASTERLY FLOW AHEAD OF THE CONVECTIVE LINE. A DENSE FOG ADVISORY DOESN`T APPEAR TO BE NEEDED AT THE MOMENT. AND FOR THE CONVECTIVE LINE...THE TIMING APPEARS TO BE UNCHANGED...ARRIVING IN THE WESTERN PIEDMONT CLOSE AROUND 4AM...THOUGH WARM ADVECTION IS LIKELY TO SUPPORT SOME PREFRONTAL SHOWERS IMMEDIATELY AHEAD OF THE LINE AS WELL. SURFACE BASED INSTABILITY WILL BE LIMITED BY THE SLOW INLAND PROGRESSION OF THE COASTAL FRONT AND WARM SECTOR...AND SO THE COASTAL PLAIN STILL APPEARS TO BE FAVORED FOR THE STRONGEST CONVECTIVE WIND GUSTS...WHERE A FEW HUNDRED J/KG OF CAPE SHOULD MATERIALIZE. MODELS STILL SHOW THE PRIMARY LOW TRACK THROUGH THE PIEDMONT...BUT IT SEEMS THIS STILL HAS SOME WESTWARD ERROR AND ANY TORNADO THREAT IS ALSO MOST LIKELY NEAR THE COAST. STILL...HRRR SOUNDINGS SUGGEST THE EROSION OF THE NEAR SURFACE STABLE LAYER AND ADDED DOWNWARD MOMENTUM TRANSPORT WITHIN THE SHOWERS AND ISOLATED THUNDERSTORMS COULD STILL LEAD TO SOME 40-50KT WIND GUSTS...PRIMARILY EAST OF HIGHWAY 1. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 255 PM MONDAY... PRECIP...IN THE FORM OF RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL BE ONGOING TO START THE DAY ON TUESDAY. THE LEADING EDGE OF THE LINE OF SHOWERS/STORMS IS EXPECTED TO BE QUICKLY RACING FROM THE TRIAD TO THE TRIANGLE BY 12Z AND AND THEN OFFSHORE BY EARLY AFTERNOON. INSTABILITY WILL BE VERY WEAK (BUT NON-ZERO) DURING THE TIME...WITH ONLY A COUPLE HUNDRED J/KG EXPECTED ACROSS THE EASTERN HALF OF THE FORECAST AREA. NEVERTHELESS...THE SPC HAS PLACED THIS AREA IN A MARGINAL RISK GIVEN THE STRONG FORCING AHEAD OF AN APPROACHING ROBUST SHORT WAVE TROUGH. IN ADDITION...AN INTENSE LOW LEVEL JET (60- 70 KNOTS)...WILL BE PRESENT...BUT RAPIDLY SHIFTING OFFSHORE THROUGH 18Z. THEREFORE...DAMAGING WINDS WILL BE POSSIBLE WITH ANY OF THE STRONGER STORMS. REGARDLESS...WINDS WILL BE RATHER GUSTY...EVEN OUTSIDE OF ANY CONVECTION...WITH GUSTS UP TO 30 MPH POSSIBLE. HIGHS SHOULD BE IN THE MID/UPPER 50S TO LOWER 60S. ANOTHER SHORT WAVE TROUGH IS EXPECTED TO SHIFT THROUGH THE REGION TUESDAY NIGHT. THERE WILL BE LIMITED MOISTURE TO WORK WITH BY THIS TIME AND THEREFORE AM NOT EXPECTING TOO MUCH IN THE WAY OF PRECIP OVERNIGHT...JUST AN INCREASE IN SOME CLOUDS. HOWEVER...GIVEN THE STRENGTH OF THIS WAVE...A SLIGHT CHANCE OF SOME LIGHT RAIN WILL BE POSSIBLE...MAINLY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA. OVERNIGHT LOWS SHOULD GENERALLY BE IN THE MID TO UPPER 30S. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 310 PM MONDAY... UPPER LEVEL TROUGH WILL PERSIST ALONG THE EASTERN SEABOARD WEDNESDAY- THURSDAY...MAINTAINING A CYCLONIC FLOW OVER CENTRAL NC. A SERIES OF UPPER DISTURBANCES ROUNDING THE BASE OF THE TROUGH WILL CAUSE PERIODS OF CLOUDINESS BUT LITTLE IN THE WAY OF PRECIP AS THE MOISTURE...WHILE ENOUGH TO PRODUCE CLOUDS...NOT ENOUGH TO GENERATE PRECIPITATION. TEMPERATURES WILL AVERAGE CLOSE TO NORMAL WITH AFTERNOON TEMPS GENERALLY 50-55 WITH OVERNIGHT LOWS A COUPLE OF DEGREES BELOW FREEZING. THE TROUGH WEAKENS AND LIFTS NEWD BY THE END OF THE WEEK...PERMITTING A PERIOD OF S/W RIDGING TO OCCUR. THIS WILL INITIATE A WARMING PERIOD WITH TEMPERATURES 5-8 DEGREES ABOVE NORMAL BY SATURDAY/SUNDAY. A S/W IN THE NORTHERN BRANCH OF THE JET STREAM WILL CROSS NORTH OF OUR REGION...DRAGGING A MOISTURE STARVED FRONT ACROSS THE AREA LATE SATURDAY-SATURDAY NIGHT. AIR MASS BEHIND THE FRONT OF PACIFIC ORIGIN SO NOT EXPECTING A BLAST OF COLD AIR. MODELS DIVERGE WITH THE STRENGTH OF THE S/W EXITING THE CENTRAL- NORTHERN PLAINS LATE SUNDAY INTO MONDAY WITH THE 00Z ECMWF DEPICTING MORE AMPLITUDE THAN THE 12Z GFS. FOR NOW...WILL INCREASE CLOUDINESS MONDAY BUT KEEP POPS AOB 20%. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 555 PM MONDAY... DANGEROUS AVIATION CONDITIONS THROUGH TONIGHT... (V)LIFR CONDITIONS; PERIODS OF PRECIPITATION --ALL OCCASIONALLY MODERATE TO HEAVY AND SOME WINTRY FOR THE NEXT SEVERAL HOURS-- AND DEVELOPING LOW LEVEL WIND SHEAR CONDITIONS...WILL AFFECT CENTRAL NC TAF SITES. SCATTERED TO NUMEROUS SHOWERS...INCLUDING MODERATE TO HEAVY FREEZING RAIN ONES OVER TRIAD TAF SITES WHERE TEMPERATURES WILL REMAIN IN THE UPPER 20S TO AROUND 30 DEGREES THROUGH AROUND MIDNIGHT...WILL TRANSITION TO LIQUID ONES AS TEMPERATURES RISE ABOVE FREEZING SHORTLY THEREAFTER. MEANWHILE TO THE EAST...THE TEMPERATURE WILL BREACH FREEZING AND RESULT IN FOLLOWING ALL LIQUID SHOWERY PRECIPITATION FROM SOUTHEAST TO NORTHWEST FROM RWI TO RDU IN THE NEXT FEW HOURS...WHILE THE TEMPERATURE HAS ALREADY RISEN ABOVE FREEZING AT FAY. AN EXPANSION OF LOCALLY DENSE FOG MAY ALSO ACCOMPANY THE ONGOING LIFR CEILINGS TONIGHT...AS A WARM FRONT RETREATS ACROSS THE AREA. THE APPROACH OF A POWERFUL UPPER LEVEL TROUGH AND PASSAGE OF AN ASSOCIATED SURFACE LOW WILL RESULT IN THE EASTWARD MIGRATION OF A BAND OF HEAVY RAIN AND ISOLATED THUNDERSTORMS ACROSS CENTRAL NC LATE TONIGHT AND EARLY TUESDAY. WINDS WESTERLY FLOW AND VFR CONDITIONS WILL DEVELOP IN THE WAKE OF THE BAND OF SHOWERS BY EARLY TUE AFTERNOON. HOWEVER...A FAST-MOVING UPPER LEVEL DISTURBANCE...ON THE HEELS OF THE LEAD ONE TONIGHT...WILL SWEEP EAST ACROSS THE MIDDLE ATLANTIC STATES LATE TUE-EARLY TUE NIGHT. LOW VFR CEILINGS AND LIGHT RAIN MAY RESULT...PARTICULARLY ACROSS NORTHERN TAF SITES. && .RAH WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 5 AM EST TUESDAY FOR NCZ007>010- 021>026-038>041-073>076-083-084. DENSE FOG ADVISORY UNTIL 3 AM EST TUESDAY FOR NCZ011-027-028- 042-043-077-085-086-088. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ038- 039. WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR NCZ007-021>024. && $$ SYNOPSIS...BADGETT NEAR TERM...SMITH SHORT TERM...KRD LONG TERM...WSS AVIATION...MWS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
935 PM CST WED FEB 17 2016 .UPDATE... ISSUED AT 917 PM CST WED FEB 17 2016 FOR LATE EVENING UPDATE HAVE INCREASED FOG COVERAGE WITH VARIOUS LOCATIONS REPORTING REDUCED VISIBILITIES OVER THE AREA. HAVE ALSO EXPANDED CLOUD COVER THROUGHOUT THE AREA AS MOIST SOUTHEAST FLOW CONTINUES TO KEEP CLOUDS IN PLACE. UPDATE ISSUED AT 624 PM CST WED FEB 17 2016 PREVIOUS FORECAST WAS IN GOOD SHAPE WITH PATCHY FOG OVER THE AREA. LOWEST VISIBILITIES REMAIN ALONG THE WESTERN EDGE OF RETREATING LOW CLOUD COVER STRETCHING FROM DICKINSON TO TIOGA. EXPECT THIS TREND TO CONTINUE WITH LOW CLOUDS DOING A VERY SLOW RETRACTION TOWARDS THE EAST THIS EVENING. UPDATES HAVE BEEN SENT. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 300 PM CST WED FEB 17 2016 PATCHY FOG AND POSSIBLE LIGHT FREEZING DRIZZLE IS IN THE FORECAST TONIGHT AND EARLY THURSDAY AHEAD OF A MILD THURSDAY AFTERNOON. LOWER ATMOSPHERIC CONDITIONS TONIGHT INTO THURSDAY MORNING WILL BE VERY FAVORABLE FOR STRATUS MAINTENANCE AND DEVELOPMENT THANKS TO A STOUT AND STRENGTHENING INVERSION ALOFT WITH MILD...SOUTHERLY LOW- LEVEL FLOW THAT WILL ACCESS DEWPOINTS WHICH AVERAGE 30 F UPSTREAM AS OF MID AFTERNOON. PATCHY FOG IS ALSO INCLUDED IN THE FORECAST GIVEN EXPECTED BUILD-DOWN OF THE STRATUS...BUT FORECAST SOUNDINGS SUGGEST THE NEAR-GROUND LAYER MAY BE TOO TURBULENT FOR DENSE FOG DEVELOPMENT OWING TO SOUTHERLY WINDS OVER 15 KT WITHIN 1000 FT OF THE SURFACE. THE 15 TO 19 UTC HRRR AND ESRL-HRRR ITERATIONS ON THE OTHER HAND SIMULATE SOME DENSE FOG DEVELOPMENT...SO WE WILL WATCH THIS SCENARIO CLOSELY EVEN THOUGH WE BELIEVE THE PROBABILITY OF ANYTHING MORE THAN TRANSIENT SUB-3/4SM VISIBILITIES IS RATHER LOW. WE CHOSE TO KEEP A SLIGHT CHANCE OF LIGHT FREEZING DRIZZLE IN THE FORECAST OVER PARTS OF CENTRAL ND TONIGHT INTO THURSDAY MORNING IN RESPECT TO THE DEEPENING MOIST LAYER BENEATH THE INVERSION SEEN ON MODEL-DERIVED FORECAST SOUNDINGS. THE 12 UTC GFS DEEPENS THE MOIST LAYER SUFFICIENTLY TO GENERATE LIGHT QPF IN ITS SIMULATION ACROSS NORTH CENTRAL AND EAST CENTRAL ND BETWEEN 06 AND 12 UTC...WHICH IS SUGGESTIVE OF A VERY LOW PROBABILITY OF BONAFIDE LIGHT FREEZING RAIN NEAR THE PEAK OF THE WARM-ADVECTIVE REGIME. HOWEVER...THAT IS AN OUTLIER SOLUTION...AND FORECAST OMEGA FIELDS FROM BOTH THE GFS AND NAM SUGGEST VERTICAL MOTION IN THE STRATUS LAYER MAY BE WEAK. WE THUS ARE NOT PARTICULARLY IMPRESSED WITH FREEZING DRIZZLE RISK EVEN THOUGH IT WAS HIGH ENOUGH TO STILL INCLUDE IN THE FORECAST. BY THURSDAY AFTERNOON...A VERY MILD AIR MASS WILL BE IN PLACE IN ADVANCE OF A STRONG 500-MB SHORTWAVE TROUGH EXPECTED TO BE MOVING INTO THE NORTHERN ROCKIES. LOW CLOUDS MAY HOLD BACK HEATING WHERE THEY REMAIN THICK ENOUGH THROUGH THE DAY...BUT WITH TEMPERATURES AT 850 MB OF +13 TO +15 C IN SOUTHWEST ND...HIGHS WILL LIKELY HIT 60 F IN PLACES LIKE BOWMAN...WITH WIDESPREAD 40S AND 50S F SOUTH AND WEST OF THE MISSOURI RIVER. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 PM CST WED FEB 17 2016 THE LONG TERM APPEARS ACTIVE WITH SEVERAL CHANCES FOR RAIN...FREEZING RAIN AND SNOW. TEMPERATURES WILL REMAIN NEAR THE MAGIC FREEZING THRESHOLD AND THEREFORE A MIX OF RAIN...FREEZING RAIN AND SNOW APPEARS POSSIBLE. LIGHT FREEZING RAIN AND SNOW APPEAR THE MORE FAVORABLE PRECIPITATION TYPE DURING THE MORNING AND EVENING HOURS OF FRIDAY...SATURDAY AND SUNDAY...CHANGING OVER TO MAINLY RAIN DURING THE AFTERNOONS. ONLY LIGHT AMOUNTS OF MOISTURE ARE EXPECTED ANY GIVEN DAY...GENERALLY LESS THAN A TENTH OF AN INCH. A CLIPPER WILL MOVE THROUGH THE NORTHERN PLAINS FRIDAY. THIS CLIPPER MAY BRING SOME HIGH WINDS TO THE REGION. MIXING WEST WINDS...STEEP LAPSE RATES AND MODERATE PRESSURE RISES COULD PRODUCE WINDS AROUND 50 MPH. IF TRENDS CONTINUE TO INDICATE THE PRESENCE OF THESE FEATURES THEN A WIND ADVISORY APPEARS LIKELY...WITH A HIGH WIND WARNING POSSIBLE. DECIDED TO WITHHOLD ISSUING A HIGH WIND WATCH TODAY AS THERE IS SOME UNCERTAINTY WITH RESPECT TO THE TIMING OF THE PRESSURE RISES AND MIXING DOWN OF MID-LEVEL WINDS AND HIGHER WINDS AREN`T EXPECTED FOR ANOTHER 48 HOURS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 917 PM CST WED FEB 17 2016 WIDESPREAD LIFR CIGS WILL REMAIN OVER THE AREA THROUGH TONIGHT INTO EARLY THURSDAY WITH GRADUAL IMPROVEMENT EXPECTED THURSDAY MORNING. BY THURSDAY MID-DAY VFR CONDITIONS EXPECTED OVER SOUTHWEST NORTH DAKOTA WHILE MOST REMAINING AREAS WILL CONTINUE TO EXPERIENCE IFR TO MVFR CIGS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...CJS LONG TERM...AJ AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
634 PM CST WED FEB 17 2016 .UPDATE... ISSUED AT 624 PM CST WED FEB 17 2016 PREVIOUS FORECAST WAS IN GOOD SHAPE WITH PATCHY FOG OVER THE AREA. LOWEST VISIBILITIES REMAIN ALONG THE WESTERN EDGE OF RETREATING LOW CLOUD COVER STRETCHING FROM DICKINSON TO TIOGA. EXPECT THIS TREND TO CONTINUE WITH LOW CLOUDS DOING A VERY SLOW RETRACTION TOWARDS THE EAST THIS EVENING. UPDATES HAVE BEEN SENT. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 300 PM CST WED FEB 17 2016 PATCHY FOG AND POSSIBLE LIGHT FREEZING DRIZZLE IS IN THE FORECAST TONIGHT AND EARLY THURSDAY AHEAD OF A MILD THURSDAY AFTERNOON. LOWER ATMOSPHERIC CONDITIONS TONIGHT INTO THURSDAY MORNING WILL BE VERY FAVORABLE FOR STRATUS MAINTENANCE AND DEVELOPMENT THANKS TO A STOUT AND STRENGTHENING INVERSION ALOFT WITH MILD...SOUTHERLY LOW- LEVEL FLOW THAT WILL ACCESS DEWPOINTS WHICH AVERAGE 30 F UPSTREAM AS OF MID AFTERNOON. PATCHY FOG IS ALSO INCLUDED IN THE FORECAST GIVEN EXPECTED BUILD-DOWN OF THE STRATUS...BUT FORECAST SOUNDINGS SUGGEST THE NEAR-GROUND LAYER MAY BE TOO TURBULENT FOR DENSE FOG DEVELOPMENT OWING TO SOUTHERLY WINDS OVER 15 KT WITHIN 1000 FT OF THE SURFACE. THE 15 TO 19 UTC HRRR AND ESRL-HRRR ITERATIONS ON THE OTHER HAND SIMULATE SOME DENSE FOG DEVELOPMENT...SO WE WILL WATCH THIS SCENARIO CLOSELY EVEN THOUGH WE BELIEVE THE PROBABILITY OF ANYTHING MORE THAN TRANSIENT SUB-3/4SM VISIBILITIES IS RATHER LOW. WE CHOSE TO KEEP A SLIGHT CHANCE OF LIGHT FREEZING DRIZZLE IN THE FORECAST OVER PARTS OF CENTRAL ND TONIGHT INTO THURSDAY MORNING IN RESPECT TO THE DEEPENING MOIST LAYER BENEATH THE INVERSION SEEN ON MODEL-DERIVED FORECAST SOUNDINGS. THE 12 UTC GFS DEEPENS THE MOIST LAYER SUFFICIENTLY TO GENERATE LIGHT QPF IN ITS SIMULATION ACROSS NORTH CENTRAL AND EAST CENTRAL ND BETWEEN 06 AND 12 UTC...WHICH IS SUGGESTIVE OF A VERY LOW PROBABILITY OF BONAFIDE LIGHT FREEZING RAIN NEAR THE PEAK OF THE WARM-ADVECTIVE REGIME. HOWEVER...THAT IS AN OUTLIER SOLUTION...AND FORECAST OMEGA FIELDS FROM BOTH THE GFS AND NAM SUGGEST VERTICAL MOTION IN THE STRATUS LAYER MAY BE WEAK. WE THUS ARE NOT PARTICULARLY IMPRESSED WITH FREEZING DRIZZLE RISK EVEN THOUGH IT WAS HIGH ENOUGH TO STILL INCLUDE IN THE FORECAST. BY THURSDAY AFTERNOON...A VERY MILD AIR MASS WILL BE IN PLACE IN ADVANCE OF A STRONG 500-MB SHORTWAVE TROUGH EXPECTED TO BE MOVING INTO THE NORTHERN ROCKIES. LOW CLOUDS MAY HOLD BACK HEATING WHERE THEY REMAIN THICK ENOUGH THROUGH THE DAY...BUT WITH TEMPERATURES AT 850 MB OF +13 TO +15 C IN SOUTHWEST ND...HIGHS WILL LIKELY HIT 60 F IN PLACES LIKE BOWMAN...WITH WIDESPREAD 40S AND 50S F SOUTH AND WEST OF THE MISSOURI RIVER. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 PM CST WED FEB 17 2016 THE LONG TERM APPEARS ACTIVE WITH SEVERAL CHANCES FOR RAIN...FREEZING RAIN AND SNOW. TEMPERATURES WILL REMAIN NEAR THE MAGIC FREEZING THRESHOLD AND THEREFORE A MIX OF RAIN...FREEZING RAIN AND SNOW APPEARS POSSIBLE. LIGHT FREEZING RAIN AND SNOW APPEAR THE MORE FAVORABLE PRECIPITATION TYPE DURING THE MORNING AND EVENING HOURS OF FRIDAY...SATURDAY AND SUNDAY...CHANGING OVER TO MAINLY RAIN DURING THE AFTERNOONS. ONLY LIGHT AMOUNTS OF MOISTURE ARE EXPECTED ANY GIVEN DAY...GENERALLY LESS THAN A TENTH OF AN INCH. A CLIPPER WILL MOVE THROUGH THE NORTHERN PLAINS FRIDAY. THIS CLIPPER MAY BRING SOME HIGH WINDS TO THE REGION. MIXING WEST WINDS...STEEP LAPSE RATES AND MODERATE PRESSURE RISES COULD PRODUCE WINDS AROUND 50 MPH. IF TRENDS CONTINUE TO INDICATE THE PRESENCE OF THESE FEATURES THEN A WIND ADVISORY APPEARS LIKELY...WITH A HIGH WIND WARNING POSSIBLE. DECIDED TO WITHHOLD ISSUING A HIGH WIND WATCH TODAY AS THERE IS SOME UNCERTAINTY WITH RESPECT TO THE TIMING OF THE PRESSURE RISES AND MIXING DOWN OF MID-LEVEL WINDS AND HIGHER WINDS AREN`T EXPECTED FOR ANOTHER 48 HOURS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 624 PM CST WED FEB 17 2016 WIDESPREAD IFR/LCL LIFR CIGS CONTINUE ACROSS THE AREA THIS EVENING. GRADUAL IMPROVEMENT TO MVFR/VFR IS EXPECTED OVER PORTIONS OF WESTERN NORTH DAKOTA TONIGHT AS LOW CIGS GRADUALLY RETRACT TOWARDS THE EAST. LOW CIGS WILL AGAIN PUSH WESTWARD FOR A PERIOD THURSDAY MORNING BEFORE IMPROVING AGAIN LATER THURSDAY MORNING/AFTERNOON OVER THE WEST. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...CJS LONG TERM...AJ AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
359 PM CST TUE FEB 16 2016 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 359 PM CST TUE FEB 16 2016 THE HIGHLIGHT IN THE SHORT TERM IS THE POTENTIAL FOR A WINTRY MIX TONIGHT. WE ARE CARRYING UP TO AROUND AN INCH OF SNOW IN THE FORECAST FROM NORTHWEST INTO SOUTH CENTRAL NORTH DAKOTA THROUGH TONIGHT ROUGHLY ALONG A LINE FROM WILLISTON TO BISMARCK AND ASHLEY. THAT IS BASED ON A BLEND OF THE 12 UTC GLOBAL MODEL QPF GUIDANCE AND THE TIME- LAGGED HIGH-RESOLUTION MODEL SUITE /INCLUDING THE RAP AND HRRR/. RADAR ECHOES ARE INTENSIFYING SOUTHWEST OF THAT LINE AS OF 2145 UTC AS MID-LEVEL FRONTOGENESIS INCREASES...AND RECENT RAP OUTPUT SUGGESTS THE FRONTOGENESIS BASED IN THE 850-700 MB LAYER WILL BE MAXIMIZED OVER CENTRAL ND AROUND 01 UTC. GIVEN A QUICK BURST OF MODERATE TO STRONG QG-FORCING TIED TO THE EXIT REGION OF A 110 KT 300-MB JET STREAK...THE AGEOSTROPHIC CIRCULATION WILL LIKELY BE SUFFICIENTLY DEEP FOR A BRIEF PERIOD OF NOTEWORTHY PRECIPITATION RATES. HOWEVER...RUN-TOTAL QPF FROM THE LAST FEW RUNS OF THE RAP AND HRRR HAS BEEN TRENDING A BIT LOWER THAN ITS EARLIER FLAVORS AND THE RESIDENCE TIME OF THE FORCING WILL BE SHORT IN ANY ONE PLACE...WHICH IS WHY WE HAVE DOWNPLAYED THE OVERALL SNOW EVENT. RELATIVELY WARM LOW- AND MID-LEVEL THERMAL PROFILES WILL LIKELY PREVENT EFFICIENT SNOW GROWTH TOO...LIMITING THE SNOW-TO-LIQUID RATIOS TO AROUND 11 TO 1. EVEN SO...GIVEN THE POTENTIAL FOR A PERIOD OF STRONG FRONTOGENESIS...WE WILL HAVE TO MONITOR LATER TRENDS IN CASE ADJUSTMENTS TO THE SNOWFALL FORECAST ARE NEEDED. NOTE THAT MAXIMUM TEMPERATURES ALOFT SUGGEST A MIX OF RAIN AND SNOW OR OUTRIGHT RAIN IN SOUTHWEST ND THROUGH THIS EVENING. THAT IDEA IS BEING CARRIED IN THE FORECAST...BUT OBSERVATIONAL TRENDS HAVE SUGGESTED WET BULB COOLING HAS BEEN FAVORING SNOW THUS FAR. FINALLY...WE ARE STILL ADVERTISING A CHANCE OF LIGHT FREEZING DRIZZLE TONIGHT ON THE BACK SIDE OF THE PRECIPITATION...AND ALL THE WAY INTO WEDNESDAY MORNING IN CENTRAL ND. FORECAST SOUNDINGS SHOW DRYING ALOFT AND A LINGERING STRATUS LAYER THAT IS MAINLY WARMER THAN -10 C...SUPPORTING POTENTIAL SUPERCOOLED DROPS AND THUS FREEZING DRIZZLE. BY WEDNESDAY AFTERNOON...THE WEATHER WILL HAVE QUIETED DOWN WITH THE AREA BETWEEN WAVES. STRATUS /LOW CLOUDS/ COULD HINDER WARMING IF IT IS THICK ENOUGH...BUT THE 12 UTC MULTI-MODEL CONSENSUS THAT WE USED TO BUILD THE FORECAST CALLS FOR HIGHS FROM THE LOWER 30S F IN JAMESTOWN TO THE LOWER 50S F IN BOWMAN. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 359 PM CST TUE FEB 16 2016 A PROGRESSIVE FLOW WITH A MEAN UPPER RIDGE IN THE WEST AND A TROUGH IN THE EAST WILL RESULT IN SERIES OF SYSTEMS WITH MIXED PRECIPITATION AND PERIODS OF WINDY CONDITIONS. BEGINNING WEDNESDAY NIGHT INTO FRIDAY...BOTH THE NAM/GFS ARE ADVERTISING AN H85 COLD POCKET TO WORK ACROSS CENTRAL NORTH DAKOTA WEDNESDAY NIGHT THROUGH THURSDAY MORNING. NAM/GFS BUFKIT SOUNDINGS AGREE THAT ENOUGH OMEGA WITHIN THE SUPERCOOLED WATER DROPLET REGIME COULD PRODUCE A LIGHT FREEZING RAIN POTENTIAL BEGINNING 09Z-12Z THURSDAY NOON THURSDAY. HAVE ADDED A SLIGHT CHANCE FOR LIGHT FREEZING RAIN INTO THE GRIDS ACROSS CENTRAL NORTH DAKOTA FROM 09Z- 18Z THURSDAY. WARM AIR ADVECTION WILL OVERSPREAD THE REGION THROUGH 00Z FRIDAY BEFORE A DOUBLE AREA OF SURFACE LOW PRESSURE AND ASSOCIATED SHORTWAVE TROUGH ALOFT SHIFT ACROSS WESTERN AND CENTRAL NORTH DAKOTA THURSDAY NIGHT INTO FRIDAY. A MIX OF RAIN/SNOW/LIGHT FREEZING RAIN ALL POSSIBLE WITH THIS SYSTEM BASED UPON LOCATION AND THERMODYNAMIC PROFILE. THE OTHER SIGNIFICANT WEATHER ELEMENT WILL BE WIND LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON. STRONGEST WINDS ARE ADVERTISED FROM MID MORNING FRIDAY THROUGH MID AFTERNOON FRIDAY WITH BOUNDARY LAYER WINDS OF BETWEEN 40KT AND 45KT ACROSS THE SOUTHWEST...AND 30KT TO 35KT MOST ELSEWHERE. POTENTIAL HIGH WIND WARNING SOUTHWEST WITH A SOLID WIND ADVISORY MOST OF WESTERN AND CENTRAL NORTH DAKOTA DURING THIS TIME. THE TIME WINDOW OVERALL IS BRIEF BUT WOULD STILL BE WORTHY OF THE ABOVE IF DATA REMAINS CONSISTENT. FRIDAY NIGHT THROUGH SUNDAY...ANOTHER CLIPPER SYSTEM WITH WARM AIR ADVECTION AHEAD OF THIS SYSTEM FRIDAY AND THE ACTUAL CLIPPER SWEEPING ACROSS SATURDAY EVENING THROUGH SUNDAY. HIGHEST PRECIPITATION CHANCES SLATED FOR NORTHERN NORTH DAKOTA SATURDAY THROUGH SUNDAY WITH DRIER CONDITIONS SOUTH. WINDS INCREASE SATURDAY NIGHT BUT REMAIN UNDER ADVISORY CRITERIA FOR NOW...WEST TO NORTHWEST WIND OF 20 TO 30 MPH. SUNDAY NIGHT THROUGH MONDAY NIGHT...THE NEXT SHORTWAVE IS FORECAST TO SHIFT ACROSS EASTERN MONTANA AND FAVOR SOUTHWEST NORTH DAKOTA MONDAY AFTERNOON THROUGH MONDAY NIGHT WITH A SLIGHT CHANCE OF SNOW. MILD HIGH TEMPERATURES THURSDAY AND FRIDAY WITH UPPER 50S SOUTHWEST TO MID 40S CENTRAL AND MID 30S TURTLE MOUNTAINS. MILD AIR CONTINUES INTO FRIDAY WITH GOOD MIXING ALOFT AND WIDESPREAD/MORE UNIFORM HIGHS IN THE 40S TO LOWER 50S SOUTHWEST. A GRADUAL COOL DOWN SATURDAY THROUGH TUESDAY...BUT REMAINING ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 359 PM CST TUE FEB 16 2016 RAIN AND SNOW WILL SPREAD EAST THROUGH THE EVENING HOURS...MAINLY TRANSITIONING TO ALL SNOW AFTER 03Z WEDNESDAY. CEILINGS HAVE BEEN VARIABLE EARLY THIS AFTERNOON...ALTERNATING BETWEEN MVFR AND IFR CONDITIONS AND VISIBILITIES. EXPECT THIS VARIANCE TO CONTINUE THROUGH THE FORECAST PERIOD. LIGHT FREEZING DRIZZLE IS POSSIBLE IN THE WAKE OF THE SNOW...AND WILL BE CONSIDERED FOR INCLUSION IN THE 00 UTC TAFS. && .HYDROLOGY... ISSUED AT 359 PM CST TUE FEB 16 2016 FLUCTUATING WATER LEVELS WILL CONTINUE ON THE MISSOURI RIVER THROUGH BISMARCK AND MANDAN THROUGH MIDWEEK. SEE THE HYDROLOGIC OUTLOOK ON OUR WEB PAGE FOR FULL DETAILS. THE LACK OF UPSTREAM ICE AND WARMER TEMPERATURES WILL HELP TO LOWER THE RISK OF HIGHER WATER OVER THE COMING DAYS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CJS LONG TERM...KS AVIATION...ZH HYDROLOGY...CJS/AJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1231 AM CST TUE FEB 16 2016 .UPDATE... ISSUED AT 1231 AM CST TUE FEB 16 2016 MAIN CHANGE THIS UPDATE WAS FOR PRECIP CHANCES EXPECTED DURING THE EARLY MORNING HOURS. MAIN AREA OF RAIN/SNOW MIX OR LIGHT SNOW HAS ALREADY EXITED THE STATE TO OUR SOUTHEAST. HOWEVER...SCATTERED LIGHT SNOW BAND EVIDENT ON REGIONAL RADARS EXTENDED FROM THE CROSBY/SHERWOOD AREA OF NORTHWESTERN NORTH DAKOTA SOUTH TOWARDS LAKE SAKAKAWEA AND THROUGH THE SOUTHERN MISSOURI VALLEY OF NORTH DAKOTA. SMALL CHANCES OF LIGHT SNOW THIS AREA EARLY THIS MORNING...DIMINISHING TOWARDS DAYBREAK. SLIGHT CHANGES IN HOURLY TEMPERATURE TRENDS. OTHERWISE THE REST OF THE FORECAST ON TRACK WITH CLOUDY SKIES EXPECTED AS NORTHWEST WINDS CONTINUE THIS MORNING. UPDATE ISSUED AT 817 PM CST MON FEB 15 2016 UPDATED POPS AND WEATHER FOR THE LATEST TRENDS. SNOW FROM MINOT SOUTHWEST TO NEAR HAZEN WILL MOVE SOUTHEAST TO BISMARCK BY 9-930. THEN SOUTHEAST TOWARD JAMESTOWN. VISIBILITIES IN THE SNOW SEEM TO DROP TO ABOUT 1 MILE AND LAST FOR ABOUT AN HOUR. AREA MOVING SOUTHEAST AT 45 TO 50 MPH. EXPECT SOME GUSTY WINDS BEHIND IT AS WELL. UPDATE ISSUED AT 635 PM CST MON FEB 15 2016 AT 630 PM CST...SEVERAL BANDS OF LIGHT PRECIPITATION WERE DETECTED BY RADAR AND SURFACE OBSERVATIONS ACROSS WEST AND CENTRAL NORTH DAKOTA. HAVE REFINED THE POPS AND WEATHER TYPES ALONE THESE OBSERVATIONS. THE FIRST AREA EXTENDED FROM ROLLA AND RUGBY SOUTHEAST TO NEAR BISMARCK. THIS AREA IS MAINLY SNOW BUT A RAIN MIX POSSIBLE EARLY AS IT MOVES THROUGH TO THE JAMES RIVER VALLEY THIS EVENING. A SECOND AREA OF SNOW BRIEFLY PRODUCED 1/2 MILE VISIBILITY FOR A SHORT TIME AT ESTEVAN SASKATCHEWAN. THIS NARROW BAND OF PRECIP WILL MOVE THROUGH NORTH CENTRAL FOLLOWING THE PREVIOUS ONE BUT REMAINING FURTHER NORTH FROM MINOT THROUGH DEVILS LAKE LATER THIS EVENING. THE PRECIPITATION WILL THEN BE GENERALLY ENDING FROM WEST TO EAST AFTER MIDNIGHT. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 334 PM CST MON FEB 15 2016 AN ACTIVE PATTERN WILL CONTINUE THE NEXT FEW DAYS...WITH A BRIEF COOL-DOWN EXPECTED ON TUESDAY. AS OF 21 UTC...LOW- AND MID-LEVEL SATURATION HAS BEEN TAKING PLACE AT A SLOWER RATE THAN PERHAPS EXPECTED BASED ON A LACK OF SURFACE PRECIPITATION REPORTS AND RELATIVELY ANEMIC REFLECTIVITY ON 0.5 DEGREE RADAR DATA. RECENT HIGH-RESOLUTION...RAPID-REFRESH MODEL GUIDANCE /INCLUDING THE RAP AND HRRR/ STILL SUPPORTS THE FORMATION OF LIGHT PRECIPITATION OVER WESTERN AND CENTRAL ND BY 00 UTC WITH THE PASSAGE OF A MID-LEVEL SHORTWAVE TROUGH. HOWEVER...THAT MODEL GUIDANCE HAS ALSO BEEN TRENDING LOWER WITH QPF...AND SINCE THAT IS IN LINE WITH OBSERVATIONAL TRENDS WE BELIEVE THAT TO BE ACCURATE. OUR FORECAST THUS CALLS FOR AN INCH OR LESS OF SNOW ACCUMULATION THROUGH TONIGHT FROM NORTH CENTRAL ND INTO THE JAMES RIVER VALLEY. THERMAL PROFILES SUPPORT RAIN INITIALLY OVER WESTERN AND PARTS OF SOUTH CENTRAL ND...BEFORE A SWITCH TO POSSIBLE LIGHT SNOW BY THE TIME THE BULK OF THE PRECIPITATION IS WINDING DOWN THIS EVENING. WE ARE STILL CALLING FOR A PERIOD OF NORTHWEST WIND GUSTS TO ABOUT 30 MPH THIS EVENING BEHIND THE SHORTWAVE TROUGH AND ACCOMPANYING SURFACE COLD FRONT BASED ON RAP-FORECAST 3-HOUR SURFACE PRESSURE CHANGES OF 3-5 MB /HIGHEST IN SOUTHWEST ND/. GUIDANCE SUGGESTS AN AREA OF STRATUS /LOW CLOUDS/ WILL FOLLOW THE SYSTEM LATE TONIGHT INTO TUESDAY...WITH SOME HINTS OF ADDITIONAL...WEAK IMPULSES IN LINGERING CYCLONIC NORTHWEST FLOW ALOFT. WE HAVE LOW POPS IN PLAY FOR SOME LIGHT SNOW OVER CENTRAL ND AFTER 06 UTC TO ACCOUNT FOR THAT...BUT FORECAST SOUNDINGS SUGGEST THE STRATUS DECK MIGHT BE WARMER THAN -12 C...SUGGESTING SOME RISK OF FREEZING DRIZZLE. WE CHOSE TO WITHHOLD THAT FROM THE FORECAST AT THIS POINT WITH WEAK VERTICAL MOTION IN THAT LAYER PER MODEL GUIDANCE. MOREOVER...THE PRECIPITATION-TYPE ALGORITHM OUTPUT FROM THE 12 UTC GLOBAL MODEL OUTPUT AND MORE RECENT HRRR AND RAP GUIDANCE SUPPORTS LIGHT SNOW AS THE PRIMARY TYPE WITH ANY LIGHT PRECIPITATION THAT MAY OCCUR AFTER MIDNIGHT AND INTO EARLY TUESDAY MORNING. THAT WILL REQUIRE MONITORING THOUGH. ON TUESDAY...A SURFACE RIDGE WILL BUILD INTO EASTERN ND AND WILL BRING A COLDER DAY TO THE AREA. WARM AIR ADVECTION WILL BEGIN TO THE WEST ACROSS MT THOUGH AND THE 12 UTC GUIDANCE ALL SUGGESTS A BAND OF LIGHT SNOW WILL MOVE INTO WESTERN ND DURING THE DAY AND INTO CENTRAL ND BY EARLY TUESDAY EVENING. THIS WOULD BE ANOTHER LIGHT QPF EVENT WITH LITTLE IN THE WAY OF IMPACTS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 334 PM CST MON FEB 15 2016 ACTIVE PERIOD WITH SEVERAL SYSTEMS SLIDING THROUGH WESTERN AND CENTRAL NORTH DAKOTA...APPROXIMATELY ONE EVERY 24HR TO 48HR. WE ARE LIKELY TO SEE A COMBINATION OR RAIN...SNOW...AND/OR LIGHT FREEZING DRIZZLE AT TIMES WITH THESE SYSTEMS. SUCCESSIVE WARM AIR ADVECTION/PRECIPITATION EVENTS WILL EVENTUALLY RESULT IN A GRADUAL WARMING TREND LATER IN THE WEEK. THE NAEFS 850T-500T SHOWS A FAIRLY STRONG THERMAL RIDGE SHIFTING OVER NORTH DAKOTA THURSDAY. 850 TEMPS OF +8C TO +10C WILL BE COMMON RESULTING IN SURFACE HIGHS IN THE 40S TO LOWER 50S. FOR TUESDAY NIGHT INTO WEDNESDAY MORNING...FIRST SHORTWAVE IN THE LONG TERM PERIOD EMBEDDED WITHIN A NORTHWEST FLOW WILL MOVE FROM WITH A SURFACE LOW REFLECTED IN SOUTHEAST MONTANA SHIFTING INTO CENTRAL SOUTH DAKOTA THROUGH WEDNESDAY MORNING. ANOTHER...STRONGER SHORTWAVE TROUGH HAS BEEN CONSISTENTLY SHOWN TO CROSS THE REGION THURSDAY NIGHT INTO FRIDAY BY THE LAST SEVERAL RUNS OF THE GFS AND ECMWF. A MIX OF PRECIPITATION IS POSSIBLE WITH THAT WAVE...AND STRONG WINDS ARE POSSIBLE ON ITS BACK SIDE IF THE 12 UTC GFS AND ECMWF ARE RIGHT WITH 850-MB WINDS UP TO 55 KT FROM THURSDAY NIGHT INTO FRIDAY. FINALLY...THERE ARE HINTS OF ONE MORE SHORTWAVE TROUGH PASSAGE ON SATURDAY OR SUNDAY...SUPPORTIVE OF MORE LOW POPS IN THAT PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1231 AM CST TUE FEB 16 2016 A COLD FRONT EXTENDED FROM SOUTHERN MINNESOTA NORTHWESTWARD ACROSS NORTH DAKOTA TO SOUTHERN SASKATCHEWAN. THE COLD HIGH PRESSURE BEHIND THE FRONT WILL MOVE SOUTHEAST INTO THE RED RIVER VALLEY LATER TUESDAY. LOOK FOR LOWERING CIGS WITH TIME AS MVFR AND IFR CIGS BECOME MORE WIDESPREAD. LIGHT SNOW POSSIBLE MAINLY AT KBIS UNTIL AROUND 10Z OR SO...BUT VFR VSBYS EXPECTED. && .HYDROLOGY... ISSUED AT 334 PM CST MON FEB 15 2016 ICE RESTRICTIONS IN THE CHANNEL AND SOME CONTRIBUTION FROM LOCAL RUNOFF DUE TO RECENT SNOWMELT HAS CAUSED THE MISSOURI RIVER TO RISE IN THE BISMARCK/MANDAN AREA. WE ARE MONITORING THE SITUATION CLOSELY AND ARE PROVIDING INFORMATION IN A HYDROLOGIC OUTLOOK ON OUR WEB PAGE. RIGHT NOW THE MAIN MESSAGE WE ARE CONVEYING IS THAT THERE WILL BE SHARP FLUCTUATIONS...WITH RAPID RISES FOLLOWED BY LOWER LEVELS...UNTIL THE ICE IS NATURALLY REMOVED BY MIDWEEK. .BIS WATCHES/WARNINGS/ADVISORIES... && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JV SHORT TERM...CJS LONG TERM...KS/CJS AVIATION...JV HYDROLOGY...CJS/KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1250 AM EST TUE FEB 16 2016 .SYNOPSIS... LOW PRESSURE WILL DEVELOP IN THE SOUTHEASTERN STATES TONIGHT...MOVING NORTHEAST INTO PENNSYLVANIA BY TUESDAY. RAIN AND SNOW ARE EXPECTED FOR THE OHIO VALLEY OVERNIGHT AND INTO THE MORNING. A WEAK MID-LEVEL TROUGH WILL PASS SOUTH OF THE REGION ON TUESDAY. AFTER THAT...GRADUAL RIDGING WILL DEVELOP BY THE END OF THE WEEK...WITH WARMING CONDITIONS THROUGH FRIDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... EXTENDED THE DENSE FOG ADVISORY A COUPLE OF COUNTIES TO THE NW...WAYNE COUNTY INDIANA AND MIAMI COUNTY OHIO...BASED ON LATEST OBSERVATIONS. FARTHER S AND E INTO THE PCPN SHIELD...THE RAIN HAS BEGUN TO CHANGE TO SNOW...ESPECIALLY IN CENTRAL OHIO. LATEST HRRR AND EARLIER RAP RUNS WERE KEEPING THE BACK EDGE OF THE PCPN SHIELD A LITTLE FARTHER E. THEREFORE TIGHTENED THE GRADIENT SOME MORE ACROSS THE FA. DRIED OUT PARTS OF THE MIAMI AND WHITEWATER VALLEY AND DIDNT CARRY ANY ACCUMULATING POPS IN SE INDIANA...BUT CANT RULE OUT SOME FLURRIES. DIDNT MAKE ANY MAJOR CHANGES TO THE SNOW TOTALS IN THE EAST. STILL EXPECT LOWS TO FALL INTO THE UPPER 20S TO LOWER 30S BY MORNING. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... THE MODEL TREND TOWARD A SOUTHERLY TRACK FOR THE MID-LEVEL TROUGH ON TUESDAY HAS CONTINUED. THOUGH GFS/NAM SOLUTIONS STILL SUGGEST PRECIPITATION IN THE SOUTHERN ILN COUNTIES...CMC/ECMWF PROJECTIONS ARE ALMOST COMPLETELY DRY. WILL KEEP SOME LOW-END POPS (WITH A CHANCE OF EITHER RAIN OR SNOW BASED ON TEMPERATURE)...WHILE ACKNOWLEDGING THAT PRECIPITATION AMOUNTS MAY VERY WELL BE ZERO OR JUST A TRACE. THERE ARE STILL SIGNS OF A VERY WEAK COLD FRONT AND SHORTWAVE MOVING INTO THE REGION ON WEDNESDAY...BUT AS CAN BE THE CASE WITH WEAK AND MOISTURE-LACKING SYSTEMS LIKE THIS...MODEL AGREEMENT ON TIMING AND PLACEMENT OF THE QPF RESPONSE IS NOT GREAT. IT IS DIFFICULT TO EVEN FOLLOW THE PLACEMENT OF THE WAVE...AND THE 500MB WIND MAX THAT ACCOMPANIES IT. TRYING TO FOLLOW THIS FEATURE AS BEST AS POSSIBLE...IT APPEARS A CHANCE OF SNOW FOR THE NORTHERN HALF OF THE FORECAST AREA IS STILL WARRANTED. ACCUMULATIONS...IF ANY...SHOULD BE VERY LIGHT. FLURRIES MIGHT END UP POSSIBLE JUST ABOUT ANYWHERE IN THE REGION. TEMPERATURES WILL CHANGE VERY LITTLE FROM TUESDAY THROUGH WEDNESDAY...WITH HIGHS TOPPING OUT IN THE 30S. MIN TEMPS TUESDAY NIGHT WILL BE A FEW DEGREES COOLER THAN THE CONDITIONS ON MONDAY NIGHT...WITH DRIER AIR MOVING IN BEHIND THE MONDAY NIGHT / TUESDAY MORNING WEATHER SYSTEM. BEHIND THE WEAK COLD FRONT ON WEDNESDAY NIGHT...MIN TEMPS SHOULD FALL BY A FEW MORE DEGREES FROM TUESDAY NIGHT. && .LONG TERM /THURSDAY THROUGH MONDAY/... HIGH PRESSURE WILL STRETCH FROM SOUTHEAST CANADA SOUTHWEST INTO THE MIDDLE OHIO VALLEY ON THURSDAY. THERE IS STILL SOME QUESTION AS TO HOW MUCH COLDER AIR WILL FILTER INTO THE REGION...SO THERE WILL BE A GRADIENT IN THE HIGH TEMPERATURES. HAVE CONTINUED WITH A BLEND OF THE GOING FORECAST AND THE 12Z ECMWF AS THIS BLEND SEEMS TO BE THE BEST SOLUTION. HIGHS WILL RANGE FROM THE LOWER 30S NORTHEAST TO THE LOWER 40S SOUTH/SOUTHWEST. FOR THURSDAY NIGHT INTO FRIDAY NIGHT ...HAVE SIDED WITH THE 12Z ECMWF AND WPC GUIDANCE WITH THE NEXT FRONT TO APPROACH AND THEN MOVE THROUGH THE REGION. MID LEVEL TROUGH IS OF PACIFIC ORIGIN AND ACTUALLY SHEARS AS IT MOVES ACROSS THE GREAT LAKES. THIS POSITION IS NOT GOOD FOR DEEP MOISTURE TRANSPORT FORM THE GULF DESPITE AN INCREASING WARM...SOUTHERLY FLOW...SO HAVE LIMITED POPS TO SLIGHT CHANCE THROUGH THIS PERIOD. TEMPERATURES WILL BOTTOM OUT EARLY THURSDAY EVENING..THEN SLOWLY RISE THROUGH THE NIGHT AS A WARM FRONT APPROACHES AND THEN LIFTS NORTHWARD THROUGH THE AREA BY FRIDAY MORNING. TEMPERATURES IN THE WARM SECTOR ON FRIDAY WILL WARM INTO THE 50S REGION WIDE...WITH A 60 DEGREE VALUE NOT OUT OF THE QUESTION ALONG AND SOUTH OF THE OHIO RIVER. SATURDAY IS EXPECTED TO BE QUIET AS SURFACE RIDGING BUILDS INTO THE REGION. CAA IS WEAK BEHIND THE COLD FRONT...SO HIGHS WILL BE MILD...IN THE 50S ONCE AGAIN. FOR SUNDAY INTO MONDAY...MODELS DIFFER ON THE STRENGTH...TIMING AND PLACEMENT OF THE NEXT WEATHER SYSTEM TO AFFECT THE REGION. IT WILL CONTINUE TO BE MILD AHEAD OF THIS SYSTEM ON SUNDAY FOLLOWED BY SOME COOLING ON MONDAY. WILL MAINTAIN A CHANCE OF RAIN DURING THIS PERIOD. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... IFR TO LIFR CONDITIONS WILL CONTINUE THROUGH THE EARLY PART OF THE TAF PERIOD. SNOW IMPACTING KCMH/KLCK AND KILN WILL MOVE OFF TO THE EAST AND END BEFORE 12Z. THERE IS SOME UNCERTAINTY WHETHER LOW VISIBILITIES IN FOG TO THE WEST OF THOSE TERMINALS WILL MOVE IN BEHIND THE SNOW. BUT LOW CEILINGS WILL PERSIST. UNCERTAINTIES FROM KDAY TO KCVG/KLUK REGARD WHEN VISIBILITIES WILL IMPROVE. CONDITIONS TO THE WEST ARE NOT AS LOW AND IT APPEARS THAT THIS MAY SPREAD IN AS STORM TO THE EAST MOVES OFF. SO HAVE BROUGHT VISIBILITIES UP TO 1SM AROUND 09Z ALTHOUGH WITH LOW CONFIDENCE. BEYOND 12Z VISIBILITIES SHOULD IMPROVE QUICKER THAN CEILINGS AREA WIDE. EXPECT IFR CEILINGS TO PERSIST INTO THE AFTERNOON AND THEN LIFT TO MVFR. LOW CLOUDS MAY SCATTER LATE IN THE TAF PERIOD. OUTLOOK...MVFR CEILINGS ARE LIKELY WITH IFR CEILINGS AND MVFR VISIBILITIES POSSIBLE WEDNESDAY INTO WEDNESDAY NIGHT. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...DENSE FOG ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR OHZ026-035-042>046-051>054-060>062-070-071-077. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR OHZ046-055-056-063>065-073-074-079>082-088. KY...DENSE FOG ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR KYZ089>093. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR KYZ097>100. IN...DENSE FOG ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR INZ050-059-066-073>075-080. && $$ SYNOPSIS...HATZOS NEAR TERM...SITES SHORT TERM...HATZOS LONG TERM...HICKMAN AVIATION...
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1124 PM CST MON FEB 15 2016 .AVIATION...16/06Z TAF ISSUANCE... A WEAK FRONTAL BOUNDARY WILL SLIDE S/SE ACROSS THE SOUTHERN PLAINS OVERNIGHT. IN RESPONSE... SOUTH WINDS WILL BEGIN TO VEER TO THE W/NW THROUGH DAYBREAK AT ALL SITES. ALONG WITH THE WIND SHIFT... MID TO HIGH STRATUS WILL INCREASE... ESPECIALLY ACROSS NORTHERN OKLAHOMA THROUGH THE FIRST HALF OF THE TAF PERIOD. WINDS WILL INCREASE MID MORNING INTO THE AFTERNOON... WITH GUSTS UP TO 25KTS... ESPECIALLY ACROSS NORTHERN AND CENTRAL OKLAHOMA. AS THE FRONT EXITS TO THE SOUTH LATE IN THE PERIOD... NORTH WINDS WILL RELAX THROUGH SUNSET... AND BEGIN TO VEER E/SE TOWARDS THE END OF THE PERIOD. JTK && .PREV DISCUSSION... /ISSUED 926 PM CST MON FEB 15 2016/ UPDATE... TWEAKED CLOUD COVER AND TEMPERATURES TONIGHT. ADDED SPRINKLE MENTION IN NORTHERN OKLAHOMA TONIGHT. INCREASED WINDS ON THURSDAY. DISCUSSION... QUIET WEATHER IS EXPECTED TONIGHT. THURSDAY WILL BE A WINDY DAY WITH VERY HIGH FIRE POTENTIAL AND NEAR RECORD WARMTH. REST OF TONIGHT...THERE MAY BE A FEW SPRINKLES BASED ON LATEST RADARS DEPICTING VERY LIGHT ECHOES IN SOUTHERN KANSAS. MENTIONED SPRINKLES IN NORTHERN OKLAHOMA...MAINLY NORTHEAST OF A CHEROKEE TO ENID TO STILLWATER LINE. OTHERWISE...RATHER QUIET WEATHER CAN BE EXPECTED. SURFACE WINDS SHOULD SLOWLY INCREASE THROUGH THE NIGHT AHEAD AND BEHIND A WEAK COLD FRONT THAT WILL MOVE THROUGH THE AREA BETWEEN MIDNIGHT TONIGHT AND 9 AM TUESDAY. CLOUDS WERE TWEAKED BASED ON LATEST SATELLITE IMAGERY AND HRRR CEILING MODEL OUTPUT. FORECAST LOWS WERE IN GOOD SHAPE...EXCEPT WERE LOWERED A FEW DEGREES SOUTHEAST OF I-44. AS FOR THURSDAY...INCREASED WINDS DURING THIS TIME FRAME...CLOSER TO CONSMOS BLEND. A WIND ADVISORY WILL LIKELY BE NECESSARY. WILDFIRE POTENTIAL WILL BE VERY HIGH DUE TO THE DRY CONDITIONS...ABUNDANT FUELS...AND NEAR RECORD WARM TEMPERATURES. SURFACE HUMIDITY VALUES REMAIN UNCERTAIN AND MAY NOT BE TOO LOW BASED ON LATEST MODEL GUIDANCE. HOWEVER...MODELS GENERALLY BEEN TOO HIGH WITH SURFACE DEWPOINTS AND TOO SHALLOW WITH VERTICAL MIXING OVER THE PAST WEEK OR TWO DUE TO THE RECENT DRY SPELL. WILL CLOSELY MONITOR THE WILDFIRE AND WIND POTENTIAL ON THIS DAY. MBS/JTK PREV DISCUSSION... /ISSUED 537 PM CST MON FEB 15 2016/ AVIATION...16/00Z TAF ISSUANCE... EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. THE PASSAGE OF A WEAK FRONTAL BOUNDARY THROUGH THE EARLY PART OF THE PERIOD WILL RESULT IN A WIND SHIFT FROM THE W/NW TO THE SOUTHWEST THROUGH THE FIRST THREE TO SIX HOURS... BEFORE SHIFTING BACK TO THE NORTHWEST THROUGH TUESDAY MORNING AND INCREASING. GUSTY WINDS WILL EXIST THROUGH THE MORNING AND MIDDAY AT MOST SITES... WITH GUSTS UP TO 25 KTS LIKELY. SCATTERED TO BROKEN HIGH CLOUDS WILL BUILD OVERNIGHT ACROSS THE REGION... SLOWLY CLEARING THROUGH THE DAY. JTK PREV DISCUSSION... /ISSUED 334 PM CST MON FEB 15 2016/ DISCUSSION... HIGH CLOUDS WILL INCREASE THIS EVENING AHEAD OF A FAST MOVING SHORTWAVE TROUGH. AN ASSOCIATED COLD FRONT WILL MOVE INTO NORTHERN OKLAHOMA BY EARLY TUESDAY...AND WILL PUSH ACROSS THE REST OF OKLAHOMA AND NORTH TEXAS BY MID AFTERNOON. THE FRONT WILL ESSENTIALLY DELAY A SIGNIFICANT WARMING TREND THAT WILL BEGIN WEDNESDAY. BY LATE WEDNESDAY...A TROUGH WILL BEGIN TO MOVE ACROSS THE PACIFIC NORTHWEST AND WILL CROSS THE NORTHERN AND CENTRAL PLAINS BY LATE THURSDAY. RATHER WINDY CONDITIONS ARE EXPECTED THURSDAY...AS A SURFACE LOW DEEPENS OVER WESTERN SOUTH DAKOTA. GULF MOISTURE WILL INCREASE SOMEWHAT LATE WEDNESDAY THROUGH THURSDAY BUT MUCH DRIER AIR OVER THE TEXAS PANHANDLE WILL MIX INTO FAR WESTERN OKLAHOMA THURSDAY AFTERNOON. THIS WILL RESULT IN TEMPERATURES WARMING INTO THE MID AND UPPER 80S. ANOTHER WEAK COLD FRONT WILL MOVE ACROSS OKLAHOMA AND NORTH TEXAS ON FRIDAY. THE MAIN RESULT WILL BE A BRIEF PERIOD OF NORTHERLY WINDS AND SLIGHTLY COOLER DAYTIME HIGHS. A STRONGER FRONT WILL MOVE ACROSS THE REGION LATE SATURDAY INTO SUNDAY. A FEW SHOWERS AND PERHAPS THUNDERSTORMS MAY DEVELOP ALONG AND NEAR THE FRONT...ESPECIALLY ACROSS THE EASTERN HALF OF OKLAHOMA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 40 65 36 71 / 0 0 0 0 HOBART OK 40 68 38 74 / 0 0 0 0 WICHITA FALLS TX 41 72 39 77 / 0 0 0 0 GAGE OK 37 64 34 73 / 0 0 0 0 PONCA CITY OK 38 62 33 69 / 10 0 0 0 DURANT OK 40 70 39 72 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 17/04/04
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
759 AM EST TUE FEB 16 2016 .SYNOPSIS... A COMPLEX STORM SYSTEM WILL MOVE NORTHEAST THROUGH THE MID ATLANTIC REGION TODAY...BRINGING A VARIETY OF WINTRY PRECIPITATION THIS MORNING...THEN RAIN AND SNOW SHOWERS THIS AFTERNOON. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE SOUTHEAST FROM THE UPPER GREAT LAKES WEDNESDAY...BRINGING ADDITIONAL SNOW SHOWERS TO NORTHWESTERN PENNSYLVANIA. HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES FRIDAY INTO SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... RAIN HAS BECOME TEMPORARILY LIGHTER AND MORE INTERMITTENT ACROSS THE SE HALF OF THE CWA THIS MORNING...AS STRENGTHENING 850-700 MB FGEN RIBBON HAS SHIFTED TO THE NW MTNS BETWEEN KFIG...KBFD...KELZ AND KELM. IN THIS AREA...WE EXTENDED THE WINTER WEATHER ADVISORY THROUGH 15Z TODAY...AND UPGRADED TO A WINTER STORM WARMING FOR SEVERAL COUNTIES IN THE WEST CENTRAL AND NW MTNS WHERE WE EXPECT TO SEE AOA O.50 INCH OF ICE ACCUM. SFC TEMPS CONTINUE TO LAG /BY UP TO SEVERAL DEG F/ THE WELL- ADVERTISED MULTI MODEL WARMUP THAT WOULD OTHERWISE CHANGE THE PRECIP OVER TO RAIN FROM SE TO NW ACROSS THE CWA EARLY TODAY. 09Z RAP DOES WARM UP THE NEAR SFC LAYER TEMPS TO THE MID 30S ACROSS THE LAURELS AND AREAS WEST OF THE SUSQ MAINSTEM LATE THIS MORNING...WITH MILDER TEMPS AROUND 40F EAST OF THE SUSQ. TEMPS ARE SHOWN BY THE RAP TO ONLY CREEP UP TO AROUND 32F THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION BY ABOUT 15Z...WHILE TEMPS STAY JUST BELOW FREEZING AT THE SFC AND ALOFT ACROSS THE FAR NW ZONES - MAINTAINING SNOW/SLEET AS THE PRIMARY PRECIP TYPE. COASTAL FRONT AND MILD AIR IN THE 40S TO ITS EAST /AND BEGINNING TO CROSS THE CHESAPEAKE BAY AND DELAWARE RIVER AT 1030Z/ SHOULD PUSH SOME MUCH MILDER AIR INTO OUR FAR ERN ZONES. HOWEVER...WITH THE LACK OF A STRONG SFC PRESSURE GRADIENT AND SOUTH TO SE FLOW PRECEDING THE LOW...IT/S DOUBTFUL THAT THE SHALLOW SUB-FREEZING AIR WILL BE ABLE TO GET SCOURED OUT OF THE CENTRAL MTNS THIS MORNING. PORTIONS OF EASTERN PA THAT BREAK INTO THE WARM SECTOR EAST OF SFC LOW SHOULD SEE HIGH TEMPS AOA 50F TUESDAY...WHILE THE NW MTNS PROBABLY BARELY GET ABV FREEZING. 998 MB SFC LOW MOVES ACROSS NCENT/NERN PENN DURING THE LATE MORNING AND EARLY AFTERNOON HOURS...WITH A COLD/OCCLUDED FRONT PUSHING EAST OF THE SUSQ VALLEY BETWEEN 18-20Z. THIS WILL SHUT DONW THE STEADY PRECIP ACROSS THE CENTRAL AND EASTERN ZONES...WHILE SOME LINGERING SNOW SHOWERS CONTINUE TO FLY ACROSS THE NW MTNS...WITH LIGHT ACCUMULATIONS OF UNDER ONE INCH. STORM TOTAL LIQ EQUIVALENT WILL BE 1.5 TO 2 INCHES...WITH THE HEAVIEST PRECIP ACROSS OUR NW ZONES EARLY TODAY...AND SHIFTING TO THE SUSQ VALLEY LATE THIS MORNING. MOST RIVER POINTS DO NOT SEEM IN DANGER OF FLOODING...ESPECIALLY CONSIDERING THAN THE RATHER DENSE SNOWPACK SHOULD ABSORB SOME OF THIS RAIN AS IT FALLS...THUS DAMPENING/SLOWING THE RESPONSE ON THE WATERWAYS. HOWEVER...THE NORMAL PLACES TO SEE RISES ON SMALL STREAMS AND CREEKS WILL CERTAINLY SEE THIS. IT IS DEFINITELY WORTH CONSIDERING A FLOOD WATCH FOR PART OF THE AREA. WILL HAVE TO MULL THIS OVER AND CONFAB WITH THE NEIGHBORING WFOS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... SLIGHTLY COLDER AIR FLOWS INTO THE REGION TONIGHT AND WEDNESDAY AS THE CURRENT LOW PRESSURE AREA LIFTS NE INTO NEW ENGLAND...AND A SECONDARY SHORT WAVES MOVES SE FROM THE GLAKES. THE COLD AIR WILL BE QUITE SHALLOW WITH THE SUBSIDNECE INVERSION BASE AOB 4 KFT AGL. THEREFORE...JUST SOME ADDITIONAL LIGHT ACCUMS OF A COATING TO AROUND 1 INCH ARE EXPECTED ACROSS THE NORTHERN AND WESTERN MTNS DURING THIS 24 HOUR PERIOD. THE CENTRAL MTNS AND SUSQ REGION SHOULD ONLY SEE A FEW FLURRIES AND SOME OCCASIONAL GLIMPSES OF SUNSHINE THROUGH THE DUAL LAYER OF CLOUDINESS DURING THE DAY WEDNESDAY. LOWS TONIGHT ARE EXPECTED TO RANGE FROM THE LOWER 20S ACROSS THE NORTHWEST...TO THE LOWER 30S IN THE FAR SE ZONES. HIGHS WEDNESDAY WILL BE NEAR FREEZING ACROSS THE NRN AND WRN MTNS...AND UPPER 30S TO LOWER 40S SE OF THE MTNS. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LOOKING A SW FLOW OF MILD AND DRY AIR OFF THE HIGH PLAINS FOR LATE IN THE WEEK. MOISTURE IS LIMITED WITH THIS AIRMASS...SO DID CUT BACK ON POPS WHERE POSSIBLE. COLDER AIR TRYS TO WORK BACK IN AFTER NEXT WEEKEND. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/... STRENGTHENING SFC LOW PRESSURE WILL TRACK ACROSS CENTRAL PENNSYLVANIA THROUGH EARLY AFTERNOON. UNTIL THEN...WIDESPREAD MAINLY IFR RESTRICTIONS...LLWS...AND ICING POTENTIAL WILL IMPACT AVIATION. POTENT SOUTHERLY 60-70KT LLJET FOCUSED OVER EASTERN HALF OF CWA AT 12Z WILL LIFT OFF TO THE EAST BY EARLY AFTERNOON. SIG SPEED SHEAR IS ASSOCIATED WITH THIS FEATURE...WITH SPEEDS INCREASING RAPIDLY BETWEEN 1000-3000FT AGL. WIDESPREAD MAINLY IFR RESTRICTIONS WILL CONTINUE AREWIDE THROUGH THE MORNING HOURS AS IMPACTS CONTINUE FROM LOW PRESSURE SYSTEM MOVING THROUGH. FREEZING RAIN CONTINUES OVER WESTERN AND CENTRAL MTNS /SNOW OVER FAR NW MTNS NEAR KBFD/ AT SUNRISE AS TEMPS REMAIN AT OR JUST BELOW FREEZING. THIS WILL KEEP POTENTIAL FOR SIG ICING AS ISSUE FOR SEVERAL MORE HOURS. ONE MORE WAVE OF PRECIP SLIDES THROUGH FROM 12-18Z...BRINGING ANOTHER PERIOD OF MORE WIDESPREAD PRECIPITATION TO ALL. ONGOING FREEZING/FROZEN PRECIP WILL TRANSITION TO A PLAIN RAIN IN MOST LOCALES AS WARMER TEMPS WORK IN FROM THE SE. OVER THE SE...THE WARMER AIR /AKA ABOVE FREEZING/ HAS ARRIVED...AND REMAINDER OF PRECIP SHOULD FALL AS PLAIN RAIN BEFORE ENDING EARLY THIS AFTERNOON. CONDITIONS BEGIN TO IMPROVE EARLY THIS AFTERNOON OVER THE SOUTHERN MTNS AND SE WITH A RETURN TO VFR. THIS SPREADS INTO NE AREAS LATE THIS AFTERNOON. BUT RESTRICTIONS WILL CONTINUE OVER WESTERN HIGHER TERRAIN AS FLOW TURNS TO THE NW BEHIND DEPARTING SYSTEM. WINDS DO PICK UP WITH PASSAGE OF COLD FRONT THIS AFTERNOON...AND AS WINDS TURN TO THE WEST SPEEDS WILL PICK UP TO AROUND 10G20KT. ANOTHER WEAKER WAVE SLIDES THROUGH ON WED...KEEPING RESTRICTIONS IN PLACE OVER THE WEST. THEY MAY SPILL INTO THE CENTRAL MTNS FOR A TIME...BUT OTHERWISE CENTRAL AND SE WILL REMAIN VFR. HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES FRIDAY INTO SATURDAY. OUTLOOK... WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE OVER THE WEST /AND POSS CENTRAL/ ALONG WITH POTENTIAL FOR LIGHT SNOW. THU...MAINLY VFR. FRI...MAINLY VFR. PERHAPS A RAIN SHOWER...MAINLY LATE. SAT...MAINLY VFR. A FEW RAIN SHOWERS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ005-006-019-025>028-037-041-042-045-046-049>053. WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR PAZ010>012-017-018-024-033>036-056-057-063>065. WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR PAZ004. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
601 AM EST TUE FEB 16 2016 .SYNOPSIS... A COMPLEX STORM SYSTEM WILL MOVE NORTHEAST THROUGH THE MID ATLANTIC REGION TODAY...BRINGING A VARIETY OF WINTRY PRECIPITATION THIS MORNING...THEN RAIN AND SNOW SHOWERS THIS AFTERNOON. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE SOUTHEAST FROM THE UPPER GREAT LAKES WEDNESDAY...BRINGING ADDITIONAL SNOW SHOWERS TO NORTHWESTERN PENNSYLVANIA. HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES FRIDAY INTO SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... RAIN HAS BECOME TEMPORARILY LIGHTER AND MORE INTERMITTENT ACROSS THE SE HALF OF THE CWA THIS MORNING...AS STRENGTHENING 850-700 MB FGEN RIBBON HAS SHIFTED TO THE NW MTNS BETWEEN KFIG...KBFD...KELZ AND KELM. IN THIS AREA...WE EXTENDED THE WINTER WEATHER ADVISORY THROUGH 15Z TODAY...AND UPGRADED TO A WINTER STORM WARMING FOR SEVERAL COUNTIES IN THE WEST CENTRAL AND NW MTNS WHERE WE EXPECT TO SEE AOA O.50 INCH OF ICE ACCUM. SFC TEMPS CONTINUE TO LAG /BY UP TO SEVERAL DEG F/ THE WELL- ADVERTISED MULTI MODEL WARMUP THAT WOULD OTHERWISE CHANGE THE PRECIP OVER TO RAIN FROM SE TO NW ACROSS THE CWA EARLY TODAY. 09Z RAP DOES WARM UP THE NEAR SFC LAYER TEMPS TO THE MID 30S ACROSS THE LAURELS AND AREAS WEST OF THE SUSQ MAINSTEM LATE THIS MORNING...WITH MILDER TEMPS AROUND 40F EAST OF THE SUSQ. TEMPS ARE SHOWN BY THE RAP TO ONLY CREEP UP TO AROUND 32F THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION BY ABOUT 15Z...WHILE TEMPS STAY JUST BELOW FREEZING AT THE SFC AND ALOFT ACROSS THE FAR NW ZONES - MAINTAINING SNOW/SLEET AS THE PRIMARY PRECIP TYPE. COASTAL FRONT AND MILD AIR IN THE 40S TO ITS EAST /AND BEGINNING TO CROSS THE CHESAPEAKE BAY AND DELAWARE RIVER AT 1030Z/ SHOULD PUSH SOME MUCH MILDER AIR INTO OUR FAR ERN ZONES. HOWEVER...WITH THE LACK OF A STRONG SFC PRESSURE GRADIENT AND SOUTH TO SE FLOW PRECEDING THE LOW...IT/S DOUBTFUL THAT THE SHALLOW SUB-FREEZING AIR WILL BE ABLE TO GET SCOURED OUT OF THE CENTRAL MTNS THIS MORNING. PORTIONS OF EASTERN PA THAT BREAK INTO THE WARM SECTOR EAST OF SFC LOW SHOULD SEE HIGH TEMPS AOA 50F TUESDAY...WHILE THE NW MTNS PROBABLY BARELY GET ABV FREEZING. 998 MB SFC LOW MOVES ACROSS NCENT/NERN PENN DURING THE LATE MORNING AND EARLY AFTERNOON HOURS...WITH A COLD/OCCLUDED FRONT PUSHING EAST OF THE SUSQ VALLEY BETWEEN 18-20Z. THIS WILL SHUT DONW THE STEADY PRECIP ACROSS THE CENTRAL AND EASTERN ZONES...WHILE SOME LINGERING SNOW SHOWERS CONTINUE TO FLY ACROSS THE NW MTNS...WITH LIGHT ACCUMULATIONS OF UNDER ONE INCH. STORM TOTAL LIQ EQUIVALENT WILL BE 1.5 TO 2 INCHES...WITH THE HEAVIEST PRECIP ACROSS OUR NW ZONES EARLY TODAY...AND SHIFTING TO THE SUSQ VALLEY LATE THIS MORNING. MOST RIVER POINTS DO NOT SEEM IN DANGER OF FLOODING...ESPECIALLY CONSIDERING THAN THE RATHER DENSE SNOWPACK SHOULD ABSORB SOME OF THIS RAIN AS IT FALLS...THUS DAMPENING/SLOWING THE RESPONSE ON THE WATERWAYS. HOWEVER...THE NORMAL PLACES TO SEE RISES ON SMALL STREAMS AND CREEKS WILL CERTAINLY SEE THIS. IT IS DEFINITELY WORTH CONSIDERING A FLOOD WATCH FOR PART OF THE AREA. WILL HAVE TO MULL THIS OVER AND CONFAB WITH THE NEIGHBORING WFOS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... SLIGHTLY COLDER AIR FLOWS INTO THE REGION TONIGHT AND WEDNESDAY AS THE CURRENT LOW PRESSURE AREA LIFTS NE INTO NEW ENGLAND...AND A SECONDARY SHORT WAVES MOVES SE FROM THE GLAKES. THE COLD AIR WILL BE QUITE SHALLOW WITH THE SUBSIDNECE INVERSION BASE AOB 4 KFT AGL. THEREFORE...JUST SOME ADDITIONAL LIGHT ACCUMS OF A COATING TO AROUND 1 INCH ARE EXPECTED ACROSS THE NORTHERN AND WESTERN MTNS DURING THIS 24 HOUR PERIOD. THE CENTRAL MTNS AND SUSQ REGION SHOULD ONLY SEE A FEW FLURRIES AND SOME OCCASIONAL GLIMPSES OF SUNSHINE THROUGH THE DUAL LAYER OF CLOUDINESS DURING THE DAY WEDNESDAY. LOWS TONIGHT ARE EXPECTED TO RANGE FROM THE LOWER 20S ACROSS THE NORTHWEST...TO THE LOWER 30S IN THE FAR SE ZONES. HIGHS WEDNESDAY WILL BE NEAR FREEZING ACROSS THE NRN AND WRN MTNS...AND UPPER 30S TO LOWER 40S SE OF THE MTNS. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LOOKING A SW FLOW OF MILD AND DRY AIR OFF THE HIGH PLAINS FOR LATE IN THE WEEK. MOISTURE IS LIMITED WITH THIS AIRMASS...SO DID CUT BACK ON POPS WHERE POSSIBLE. COLDER AIR TRYS TO WORK BACK IN AFTER NEXT WEEKEND. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... ELONGATED SFC LOW PRESSURE OVER THE SOUTHERN APPALACHIANS WILL SLOWLY STRENGTHEN AS IT MOVES NORTHEAST AND TRACKS ACROSS CENTRAL PENNSYLVANIA LATE THIS MORNING. UNTIL THEN...WIDESPREAD RESTRICTIONS...LLWS AND ICING POTENTIAL WILL IMPACT AVIATION. POTENT SOUTHERLY 60KT LLJET WILL SWING THROUGH OVER NEXT 6-12HRS...WITH SPEEDS INCREASING RAPIDLY BETWEEN 1000-3000FT. STRONGEST SHEAR WILL BE OVER SE HALF OF CWA. WIDESPREAD RESTRICTIONS WILL CONTINUE AREWIDE THROUGH THE OVERNIGHT HOURS AS IMPACTS FROM WINTRY MIX OF PRECIPITATION CONTINUES. TREND THROUGH SUNRISE WILL BE FOR FREEZING RAIN TO BECOME MORE SCATTERED OVER THE SUSQ VALLEY...BUT ANOTHER WAVE SLIDES THROUGH FROM 12-18Z BRINGING ANOTHER PERIOD OF MORE WIDESPREAD PRECIPITATION THERE. ONGOING FREEZING RAIN AND SNOW WILL CONTINUE THROUGH THAT PERIOD IN THE CENTRAL AND NW MTNS. WITH WARMER TEMPS SLIDING IN FROM THE SE...PRECIP WILL TRANSITION TO AND END AS RAIN IN MOST PLACES DURING THE LATE MORNING AND AFTERNOON HOURS. BUT ICING WILL REMAIN AN ISSUE THROUGH THEN. CONDITIONS BEGIN TO IMPROVE EARLY THIS AFTERNOON OVER THE SOUTHERN MTNS AND SE WITH A RETURN TO VFR. THIS SPREADS INTO THE NE LATE THIS AFTERNOON. BUT RESTRICTIONS WILL CONTINUE OVER WESTERN HIGHER TERRAIN AS FLOW TURNS TO THE NW BEHIND DEPARTING SYSTEM. ANOTHER WEAKER WAVE SLIDES THROUGH ON WED...KEEPING RESTRICTIONS IN PLACE OVER THE WEST. THEY MAY SPILL INTO THE CENTRAL MTNS FOR A TIME...BUT OTHERWISE CENTRAL AND SE WILL REMAIN VFR. HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES FRIDAY INTO SATURDAY. OUTLOOK... WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE OVER THE WEST /AND POSS CENTRAL/ ALONG WITH POTENTIAL FOR LIGHT SNOW. THU...MAINLY VFR. FRI...MAINLY VFR. PERHAPS A RAIN SHOWER...MAINLY LATE. SAT...MAINLY VFR. A FEW RAIN SHOWERS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ005-006-019-025>028-037-041-042-045. WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR PAZ010>012-017-018-024. WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR PAZ033>036-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ046- 049>053. WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR PAZ004. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
318 AM EST TUE FEB 16 2016 .SYNOPSIS... ELONGATED SFC LOW PRESSURE OVER THE SOUTHERN APPALACHIANS WILL SLOWLY STRENGTHEN AS IT MOVES NORTHEAST AND TRACKS ACROSS CENTRAL PENNSYLVANIA LATE THIS MORNING. THIS WEATHER SYSTEM WILL BRING A PROLONGED MIXED PRECIPITATION EVENT TO CENTRAL PENNSYLVANIA THAT WILL END AS RAIN IN MOST PLACES DURING THE LATE MORNING AND AFTERNOON HOURS TODAY. HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES FRIDAY INTO SATURDAY. && .NEAR TERM /UNTIL 10 AM THIS MORNING/... SFC TEMPS CONTINUE TO LAG /BY SEVERAL DEG F/ THE WELL-ADVERTISED MULTI-MODEL WARMUP THAT WOULD OTHERWISE CHANGE THE PRECIP OVER TO RAIN FROM SE TO NW ACROSS THE CWA EARLY TODAY. 06Z RAP DOES WARM UP THE NEAR SFC LAYER TEMPS AT ABOUT 1.5F/HR FROM NOW THROUGH 14Z...WHICH LEADS TO A CHANGEOVER FROM ICY TO MAINLY LIQUID PRECIP BETWEEN 12-13Z TODAY. POCKETS OF FZRA AND PL WILL LIKELY LINGER INTO LATE THIS MORNING...WHICH MAY MEAN EXTENDING THE CURRENT WINTER WEATHER FLAGS ACROSS OUR CENTRAL ZONES BY UP TO 2-3 HOURS. COASTAL FRONT AND MILD AIR IN THE 40S TO ITS EAST /AND EAST OF THE CHESAPEAKE BAY AND DELAWARE RIVER AT 0730Z/ MAY PUSH SOME MILDER AIR INTO OUR FAR SE ZONES. HOWEVER...WITH THE LACK OF A STRONG SFC PRESSURE GRADIENT AND SOUTH TO SE FLOW PRECEDING THE LOW...IT/S DOUBTFUL THAT THE SHALLOW SUB-FREEZING AIR WILL BE ABLE TO GET SCOURED OUT OF THE CENTRAL MTNS THIS MORNING. MAY HAVE TO EXTEND THE WINTER STORM WARNING FURTHER NORTH BY 2-3 LAYERS OF COUNTIES WITH THE 4 AM UPDATE...BASED ON PRECIP RATES OF 0.10-0.15 WHERE FZRA IS OCCURRING. WILL BE EVALUATING THIS ASPECT OF THE FCST VERY CLOSELY OVER THE NEXT FEW HOURS. PREVIOUS DISC... HAVE CHANGED THE SRN TIER OVER TO A WINTER STORM WARNING WITH HEAVY EMPHASIS ON ICE FROM FREEZING RAIN. CHANGEOVER TO PLAIN RAIN STILL EXPECTED TO OCCUR NEAR SUNRISE FOR THE BULK OF THE AREA. IT SHOULD TURN OVER A LITTLE EARLIER IN THE SE AND ON THE EDGES OF THE FAR E AND FAR W. 630 PM UPDATE... SLEET WIDESPREAD ACROSS THE SERN 3 COS...WITH FZRA JUST ACROSS THE MD BORDER. CHANGEOVER IS HAPPENING RIGHT ON SCHEDULE AND AS EXPECTED. ONE WORRY IS THAT THE NORTHERLY WINDS ARE SEEN ALL THE WAY INTO CENT NORTH CAROLINA WHILE THE FCST FROM ALL MDLS - ESP RAP/HRRR - ARE MORE EASTERLY/SERLY. THIS SEEMS TO BE A SIGN THAT CAD COULD BE STRONGER THAN EXPECTED CURRENTLY. CONCERN IS THAT SLEET/FZRA WILL LAST A FEW HOURS LONGER IN THE EAST. EARLIER SHIFTS HAD BUMPED ICE NUMBERS UP AND ANOTHER SLIGHT TICK UPWARD IS ON ORDER NOW TOO. NO REASON TO PANIC OR KNEEJERK WITH THE EVENT JUST STARTING AND STRONG WAA UNDERWAY ALOFT. NO HEADLINE CHANGES PLANNED WITH FIRST SURGE OF REAL MIXED PRECIP JUST INTO THE AREA AT THIS HOUR. ANOTHER CONCERN IS FOR MINOR FLOODING. FOR MANY SHIFTS WE HAVE BEEN WATCHING THE AXIS OF HEAVIEST QPF WAGGLE WEST THEN EAST AND ALL THE WHILE STAYING CONSISTENT AT 1.5 TO 2 INCHES TOTAL LIQUID. MOST RIVER POINTS DO NO SEEM IN DANGER OF FLOODING...ESP IF THE SNOWPACK CAN ABSORB SOME OF THIS RAIN AS IT FALLS...THUS DAMPENING/SLOWING THE RESPONSE ON THE WATERWAYS. HOWEVER...THE NORMAL PLACES TO SEE RISES ON SMALL STREAMS AND CREEKS WILL CERTAINLY SEE THIS. IT IS DEFINITELY WORTH CONSIDERING A FLOOD WATCH FOR PART OF THE AREA. WILL HAVE TO MULL THIS OVER AND CONFAB WITH THE NEIGHBORING WFOS. PREV... LULL IN SNOWFALL COMING TO AN END SHORTLY. UPSTREAM PRECIPITATION SHIELD EXPANDING FROM JUST SOUTH OF THE MASON DIXON TO THE LOWER MISSISSIPPI RIVER VALLEY AS LOW PRESSURE DEEPENS AND RACES NORTHEASTWARD TO THE CENTRAL APPALACHIANS BY LATE TONIGHT. ANOTHER ROUND OF SNOW WILL SPREAD NORTHWARD LATE THIS AFTERNOON AND EVENING AS THE MAIN EVENT GETS GOING. INCREASING ISENTROPIC LIFT AND MOISTURE RETURN OVERSPREADS THE STATE FROM THE SOUTH THIS EVENING...AS STRENGTHENING SOUTHERLY LL JET FORMS OVR THE EASTERN CONUS IN RESPONSE TO DIGGING UPPER TROF OVR THE MISS VALLEY. EXPECT A PERIOD OF STEADIER/HEAVIER SNOW TO MOVE INTO THE SOUTHERN COUNTIES THIS AFTN WITH A FEW INCHES OF ACCUM LIKELY BEFORE WARMING ALOFT RESULTS IN CHANGEOVER TO MIXED PRECIP THIS EVENING. NO ADDITIONAL HEADLINE CHANGES THIS AFTERNOON...AFTER EARLIER ADJUSTING ALIGNMENT OF EXISTING ADVISORIES OVERNIGHT (PATCHY FREEZING RAIN LASTING LONGER OVER THE SOUTH CENTRAL MOUNTAINS ALONG THE MD BORDER)...AND UPGRADING TO WINTER STORM WARNINGS FOR BEDFORD AND SOMERSET FOR COUNTY WIDE AVERAGE OF 0.25" OF ICE.. FLOOD WATCHES CONSIDERED BUT COLDER SOLUTIONS (AND EVEN COLDER BY 12Z ECMWF) PRECLUDE RAPID SNOWMELT...BUT RATHER ABSORPTION OF RAINFALL INTO SNOWPACK LATE TONIGHT AND TUESDAY. CONSENSUS OF 12Z GUIDANCE...INCLUDING A QUICK LOOK AT 12Z ECMWF... ALL INDICATE A STEADY SOUTH OT NORTH TRANSITION FROM SNOW TO FZRA AND EVENTUALLY RAIN OVER MOST OF CENTRAL PA TONIGHT. BY 06-08ZZ SNOW/MIX LINE SHOULD BE OVR THE NW MTNS. EXPECT FREEZING RAIN TO LINGER LONGEST ALONG AND JUST EAST OF THE ALLEGHENY CREST FROM BEDFORD AND BLAIR COUNTIES NORTHWARD TO CLEARFIELD AND CENTRE COUNTIES THROUGH 12Z TUE. && .SHORT TERM /10 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... LOOKED AT THE GUIDANCE AND WPC MAPS. CURRENT POPS...WEATHER...AND QPF LOOK GOOD FOR TUE. SYSTEM IS IN 3 PHASES. ONE BATCH OF SNOW MOVED ACROSS THE REGION EARLIER TODAY. ANOTHER SMALL AREA JUST BRUSHING THE SE PART OF THE CWA THE LAST FEW HRS. WARM ADVECTION WILL DRIVE NEXT BATCH OF PCPN. MODELS STILL SHOW THE UPPER LVL TROUGH GOING NEGATIVE TILT ON TUE. FOR NOW...DID NOT ADD THUNDER TO THE FCST. ALSO HELD OFF ANY FLOOD WATCHES FOR NOW. HAVE TO WATCH FOR HEAVY...WET SNOW ON THE BACK SIDE OF THIS SYSTEM. MORE DETAILS BELOW. BY DAWN TUESDAY...THERE REMAINS BROAD AGREEMENT AMONG GUIDANCE THAT PTYPE WILL BE PLAIN RAIN OVER ALL OF CENTRAL PA WITH THE EXCEPTION OF WARREN AND POSSIBLY MCKEAN COUNTY. WINTER STOR4M WARNING MAINTAINED FOR WARREN COUNTY WHERE 6-10 INCH AMTS MOST LIKELY. 0C 850 ISOTHERM IN MOST MDL GUIDANCE SUGGESTS MCKEAN CO WILL LIKELY CHANGEOVER TO RAIN/FZRA...KEEPING AMTS JUST BLW 12 AND 24HR WARNING CRITERIA. IN GENERAL...ICE ACCUMS EXPECTED TO REMAIN IN THE ADVISORY CATEGORY PER WPC GUIDANCE. LOCALLY HVY RAIN...COMBINED WITH SNOWMELT WILL POSE A FLOODING THREAT ACROSS EASTERN PA ON TUESDAY. LATEST RIVER ENSEMBLE OUTPUT AND WPC GUIDANCE SUGGEST MINOR FLOODING COULD BE A CONCERN. WILL HIGHLIGHT THIS THREAT IN THE HWO. HEAVIEST PRECIP WILL PASS EAST OF THE REGION BY TUESDAY AFTN...AS ANOMALOUS LL JET/PWATS SHIFT EAST. HOWEVER...POTENT MID LVL SHORTWAVE LIFTING NE THRU THE AREA WILL PRODUCE NUMEROUS RAIN/SNOW SHOWERS INTO THE AFTN ESP ACROSS THE W MTNS. MDL SOUNDINGS SUPPORT A FEW ADDITIONAL INCHES OF SNOW ACCUM ACROSS WARREN AND POSSIBLY MCKEAN COS DURING THE DAYLIGHT HRS OF TUESDAY. PORTIONS OF EASTERN PA THAT BREAK INTO THE WARM SECTOR EAST OF SFC LOW SHOULD SEE HIGH TEMPS AOA 50F TUESDAY...WHILE THE NW MTNS PROBABLY BARELY GET ABV FREEZING. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LOOKING A SW FLOW OF MILD AND DRY AIR OFF THE HIGH PLAINS FOR LATE IN THE WEEK. MOISTURE IS LIMITED WITH THIS AIRMASS...SO DID CUT BACK ON POPS WHERE POSSIBLE. COLDER AIR TRYS TO WORK BACK IN AFTER NEXT WEEKEND. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... ELONGATED SFC LOW PRESSURE OVER THE SOUTHERN APPALACHIANS WILL SLOWLY STRENGTHEN AS IT MOVES NORTHEAST AND TRACKS ACROSS CENTRAL PENNSYLVANIA LATE THIS MORNING. UNTIL THEN...WIDESPREAD RESTRICTIONS...LLWS AND ICING POTENTIAL WILL IMPACT AVIATION. POTENT SOUTHERLY 60KT LLJET WILL SWING THROUGH OVER NEXT 6-12HRS...WITH SPEEDS INCREASING RAPIDLY BETWEEN 1000-3000FT. STRONGEST SHEAR WILL BE OVER SE HALF OF CWA. WIDESPREAD RESTRICTIONS WILL CONTINUE AREWIDE THROUGH THE OVERNIGHT HOURS AS IMPACTS FROM WINTRY MIX OF PRECIPITATION CONTINUES. TREND THROUGH SUNRISE WILL BE FOR FREEZING RAIN TO BECOME MORE SCATTERED OVER THE SUSQ VALLEY...BUT ANOTHER WAVE SLIDES THROUGH FROM 12-18Z BRINGING ANOTHER PERIOD OF MORE WIDESPREAD PRECIPITATION THERE. ONGOING FREEZING RAIN AND SNOW WILL CONTINUE THROUGH THAT PERIOD IN THE CENTRAL AND NW MTNS. WITH WARMER TEMPS SLIDING IN FROM THE SE...PRECIP WILL TRANSITION TO AND END AS RAIN IN MOST PLACES DURING THE LATE MORNING AND AFTERNOON HOURS. BUT ICING WILL REMAIN AN ISSUE THROUGH THEN. CONDITIONS BEGIN TO IMPROVE EARLY THIS AFTERNOON OVER THE SOUTHERN MTNS AND SE WITH A RETURN TO VFR. THIS SPREADS INTO THE NE LATE THIS AFTERNOON. BUT RESTRICTIONS WILL CONTINUE OVER WESTERN HIGHER TERRAIN AS FLOW TURNS TO THE NW BEHIND DEPARTING SYSTEM. ANOTHER WEAKER WAVE SLIDES THROUGH ON WED...KEEPING RESTRICTIONS IN PLACE OVER THE WEST. THEY MAY SPILL INTO THE CENTRAL MTNS FOR A TIME...BUT OTHERWISE CENTRAL AND SE WILL REMAIN VFR. HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES FRIDAY INTO SATURDAY. OUTLOOK... WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE OVER THE WEST /AND POSS CENTRAL/ ALONG WITH POTENTIAL FOR LIGHT SNOW. THU...MAINLY VFR. FRI...MAINLY VFR. PERHAPS A RAIN SHOWER...MAINLY LATE. SAT...MAINLY VFR. A FEW RAIN SHOWERS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ005- 006-010>012-017-018-024-037-041-042. WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR PAZ033>036-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ019- 025>028-045-046-049>053. WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR PAZ004. && $$ SYNOPSIS...DEVOIR/LAMBERT NEAR TERM...DANGELO/DEVOIR/LAMBERT SHORT TERM...FITZGERALD/MARTIN LONG TERM...MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
241 AM EST TUE FEB 16 2016 .SYNOPSIS... ELONGATED SFC LOW PRESSURE OVER THE SOUTHERN APPALACHIANS WILL SLOWLY STRENGTHEN AS IT MOVES NORTHEAST AND TRACKS ACROSS CENTRAL PENNSYLVANIA LATE THIS MORNING. THIS WEATHER SYSTEM WILL BRING A PROLONGED MIXED PRECIPITATION EVENT TO CENTRAL PENNSYLVANIA THAT WILL END AS RAIN IN MOST PLACES DURING THE LATE MORNING AND AFTERNOON HOURS TODAY. HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES FRIDAY INTO SATURDAY. && .NEAR TERM /UNTIL 10 AM THIS MORNING/... SFC TEMPS CONTINUE TO LAG /BY SEVERAL DEG F/ THE WELL-ADVERTISED MULTI-MODEL WARMUP THAT WOULD OTHERWISE CHANGE THE PRECIP OVER TO RAIN FROM SE TO NW ACROSS THE CWA EARLY TODAY. 06Z RAP DOES WARM UP THE NEAR SFC LAYER TEMPS AT ABOUT 1.5F/HR FROM NOW THROUGH 14Z...WHICH LEADS TO A CHANGEOVER FROM ICY TO MAINLY LIQUID PRECIP BETWEEN 12-13Z TODAY. POCKETS OF FZRA AND PL WILL LIKELY LINGER INTO LATE THIS MORNING...WHICH MAY MEAN EXTENDING THE CURRENT WINTER WEATHER FLAGS ACROSS OUR CENTRAL ZONES BY UP TO 2-3 HOURS. COASTAL FRONT AND MILD AIR IN THE 40S TO ITS EAST /AND EAST OF THE CHESAPEAKE BAY AND DELAWARE RIVER AT 0730Z/ MAY PUSH SOME MILDER AIR INTO OUR FAR SE ZONES. HOWEVER...WITH THE LACK OF A STRONG SFC PRESSURE GRADIENT AND SOUTH TO SE FLOW PRECEDING THE LOW...IT/S DOUBTFUL THAT THE SHALLOW SUB-FREEZING AIR WILL BE ABLE TO GET SCOURED OUT OF THE CENTRAL MTNS THIS MORNING. MAY HAVE TO EXTEND THE WINTER STORM WARNING FURTHER NORTH BY 2-3 LAYERS OF COUNTIES WITH THE 4 AM UPDATE...BASED ON PRECIP RATES OF 0.10-0.15 WHERE FZRA IS OCCURRING. WILL BE EVALUATING THIS ASPECT OF THE FCST VERY CLOSELY OVER THE NEXT FEW HOURS. PREVIOUS DISC... HAVE CHANGED THE SRN TIER OVER TO A WINTER STORM WARNING WITH HEAVY EMPHASIS ON ICE FROM FREEZING RAIN. CHANGEOVER TO PLAIN RAIN STILL EXPECTED TO OCCUR NEAR SUNRISE FOR THE BULK OF THE AREA. IT SHOULD TURN OVER A LITTLE EARLIER IN THE SE AND ON THE EDGES OF THE FAR E AND FAR W. 630 PM UPDATE... SLEET WIDESPREAD ACROSS THE SERN 3 COS...WITH FZRA JUST ACROSS THE MD BORDER. CHANGEOVER IS HAPPENING RIGHT ON SCHEDULE AND AS EXPECTED. ONE WORRY IS THAT THE NORTHERLY WINDS ARE SEEN ALL THE WAY INTO CENT NORTH CAROLINA WHILE THE FCST FROM ALL MDLS - ESP RAP/HRRR - ARE MORE EASTERLY/SERLY. THIS SEEMS TO BE A SIGN THAT CAD COULD BE STRONGER THAN EXPECTED CURRENTLY. CONCERN IS THAT SLEET/FZRA WILL LAST A FEW HOURS LONGER IN THE EAST. EARLIER SHIFTS HAD BUMPED ICE NUMBERS UP AND ANOTHER SLIGHT TICK UPWARD IS ON ORDER NOW TOO. NO REASON TO PANIC OR KNEEJERK WITH THE EVENT JUST STARTING AND STRONG WAA UNDERWAY ALOFT. NO HEADLINE CHANGES PLANNED WITH FIRST SURGE OF REAL MIXED PRECIP JUST INTO THE AREA AT THIS HOUR. ANOTHER CONCERN IS FOR MINOR FLOODING. FOR MANY SHIFTS WE HAVE BEEN WATCHING THE AXIS OF HEAVIEST QPF WAGGLE WEST THEN EAST AND ALL THE WHILE STAYING CONSISTENT AT 1.5 TO 2 INCHES TOTAL LIQUID. MOST RIVER POINTS DO NO SEEM IN DANGER OF FLOODING...ESP IF THE SNOWPACK CAN ABSORB SOME OF THIS RAIN AS IT FALLS...THUS DAMPENING/SLOWING THE RESPONSE ON THE WATERWAYS. HOWEVER...THE NORMAL PLACES TO SEE RISES ON SMALL STREAMS AND CREEKS WILL CERTAINLY SEE THIS. IT IS DEFINITELY WORTH CONSIDERING A FLOOD WATCH FOR PART OF THE AREA. WILL HAVE TO MULL THIS OVER AND CONFAB WITH THE NEIGHBORING WFOS. PREV... LULL IN SNOWFALL COMING TO AN END SHORTLY. UPSTREAM PRECIPITATION SHIELD EXPANDING FROM JUST SOUTH OF THE MASON DIXON TO THE LOWER MISSISSIPPI RIVER VALLEY AS LOW PRESSURE DEEPENS AND RACES NORTHEASTWARD TO THE CENTRAL APPALACHIANS BY LATE TONIGHT. ANOTHER ROUND OF SNOW WILL SPREAD NORTHWARD LATE THIS AFTERNOON AND EVENING AS THE MAIN EVENT GETS GOING. INCREASING ISENTROPIC LIFT AND MOISTURE RETURN OVERSPREADS THE STATE FROM THE SOUTH THIS EVENING...AS STRENGTHENING SOUTHERLY LL JET FORMS OVR THE EASTERN CONUS IN RESPONSE TO DIGGING UPPER TROF OVR THE MISS VALLEY. EXPECT A PERIOD OF STEADIER/HEAVIER SNOW TO MOVE INTO THE SOUTHERN COUNTIES THIS AFTN WITH A FEW INCHES OF ACCUM LIKELY BEFORE WARMING ALOFT RESULTS IN CHANGEOVER TO MIXED PRECIP THIS EVENING. NO ADDITIONAL HEADLINE CHANGES THIS AFTERNOON...AFTER EARLIER ADJUSTING ALIGNMENT OF EXISTING ADVISORIES OVERNIGHT (PATCHY FREEZING RAIN LASTING LONGER OVER THE SOUTH CENTRAL MOUNTAINS ALONG THE MD BORDER)...AND UPGRADING TO WINTER STORM WARNINGS FOR BEDFORD AND SOMERSET FOR COUNTY WIDE AVERAGE OF 0.25" OF ICE.. FLOOD WATCHES CONSIDERED BUT COLDER SOLUTIONS (AND EVEN COLDER BY 12Z ECMWF) PRECLUDE RAPID SNOWMELT...BUT RATHER ABSORPTION OF RAINFALL INTO SNOWPACK LATE TONIGHT AND TUESDAY. CONSENSUS OF 12Z GUIDANCE...INCLUDING A QUICK LOOK AT 12Z ECMWF... ALL INDICATE A STEADY SOUTH OT NORTH TRANSITION FROM SNOW TO FZRA AND EVENTUALLY RAIN OVER MOST OF CENTRAL PA TONIGHT. BY 06-08ZZ SNOW/MIX LINE SHOULD BE OVR THE NW MTNS. EXPECT FREEZING RAIN TO LINGER LONGEST ALONG AND JUST EAST OF THE ALLEGHENY CREST FROM BEDFORD AND BLAIR COUNTIES NORTHWARD TO CLEARFIELD AND CENTRE COUNTIES THROUGH 12Z TUE. && .SHORT TERM /10 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... LOOKED AT THE GUIDANCE AND WPC MAPS. CURRENT POPS...WEATHER...AND QPF LOOK GOOD FOR TUE. SYSTEM IS IN 3 PHASES. ONE BATCH OF SNOW MOVED ACROSS THE REGION EARLIER TODAY. ANOTHER SMALL AREA JUST BRUSHING THE SE PART OF THE CWA THE LAST FEW HRS. WARM ADVECTION WILL DRIVE NEXT BATCH OF PCPN. MODELS STILL SHOW THE UPPER LVL TROUGH GOING NEGATIVE TILT ON TUE. FOR NOW...DID NOT ADD THUNDER TO THE FCST. ALSO HELD OFF ANY FLOOD WATCHES FOR NOW. HAVE TO WATCH FOR HEAVY...WET SNOW ON THE BACK SIDE OF THIS SYSTEM. MORE DETAILS BELOW. BY DAWN TUESDAY...THERE REMAINS BROAD AGREEMENT AMONG GUIDANCE THAT PTYPE WILL BE PLAIN RAIN OVER ALL OF CENTRAL PA WITH THE EXCEPTION OF WARREN AND POSSIBLY MCKEAN COUNTY. WINTER STOR4M WARNING MAINTAINED FOR WARREN COUNTY WHERE 6-10 INCH AMTS MOST LIKELY. 0C 850 ISOTHERM IN MOST MDL GUIDANCE SUGGESTS MCKEAN CO WILL LIKELY CHANGEOVER TO RAIN/FZRA...KEEPING AMTS JUST BLW 12 AND 24HR WARNING CRITERIA. IN GENERAL...ICE ACCUMS EXPECTED TO REMAIN IN THE ADVISORY CATEGORY PER WPC GUIDANCE. LOCALLY HVY RAIN...COMBINED WITH SNOWMELT WILL POSE A FLOODING THREAT ACROSS EASTERN PA ON TUESDAY. LATEST RIVER ENSEMBLE OUTPUT AND WPC GUIDANCE SUGGEST MINOR FLOODING COULD BE A CONCERN. WILL HIGHLIGHT THIS THREAT IN THE HWO. HEAVIEST PRECIP WILL PASS EAST OF THE REGION BY TUESDAY AFTN...AS ANOMALOUS LL JET/PWATS SHIFT EAST. HOWEVER...POTENT MID LVL SHORTWAVE LIFTING NE THRU THE AREA WILL PRODUCE NUMEROUS RAIN/SNOW SHOWERS INTO THE AFTN ESP ACROSS THE W MTNS. MDL SOUNDINGS SUPPORT A FEW ADDITIONAL INCHES OF SNOW ACCUM ACROSS WARREN AND POSSIBLY MCKEAN COS DURING THE DAYLIGHT HRS OF TUESDAY. PORTIONS OF EASTERN PA THAT BREAK INTO THE WARM SECTOR EAST OF SFC LOW SHOULD SEE HIGH TEMPS AOA 50F TUESDAY...WHILE THE NW MTNS PROBABLY BARELY GET ABV FREEZING. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LOOKING A SW FLOW OF MILD AND DRY AIR OFF THE HIGH PLAINS FOR LATE IN THE WEEK. MOISTURE IS LIMITED WITH THIS AIRMASS...SO DID CUT BACK ON POPS WHERE POSSIBLE. COLDER AIR TRYS TO WORK BACK IN AFTER NEXT WEEKEND. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... LATEST RADAR HAS SNOW THROUGH THE NORTHERN HALF OF CENTRAL PA WITH FREEZING RAIN AND SLEET MOVING THROUGH THE SOUTHERN HALF AND INTO CENTRAL PA. EXPECT TAF SITES TO BE IFR AND LOWER. CURRENTLY UNF AND IPT ARE MVFR IN THE FREEZING RAIN WITH PERIODS OF IFR...THIS SHOULD CONTINUE OVER THE NEXT FEW HOURS AS THEY TRANSITION. IFR ELSEWHERE. EXPECT THE PRECIPITATION TO TRANSITION FROM WINTRY MIX TO RAIN 09Z TO 14Z...WITH SLOWLY IMPROVING CONDITIONS TUESDAY MORNING INTO THE AFTERNOON...WITH VFR LATE TUESDAY AFTERNOON. THE OTHER FORECAST ISSUE IS THE WIND SHEAR ALOFT AT ALL TAF SITES OUTSIDE OF BFD. EXPECT UPWARDS OF 50KTS OF SHEAR BETWEEN 07Z TO 14Z AS THE GRADIENT PASSES. OUTLOOK... WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST. THU...MAINLY VFR. FRI...MAINLY VFR. PERHAPS A RAIN SHOWER...MAINLY LATE. SAT...MAINLY VFR. A FEW RAIN SHOWERS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ005- 006-010>012-017-018-024-037-041-042. WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR PAZ033>036-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ019- 025>028-045-046-049>053. WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR PAZ004. && $$ SYNOPSIS...DEVOIR/LAMBERT NEAR TERM...DANGELO/DEVOIR/LAMBERT SHORT TERM...FITZGERALD/MARTIN LONG TERM...MARTIN AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
555 PM CST WED FEB 17 2016 .AVIATION.../00Z TAF CYCLE/ VFR CONDITIONS PREVAIL ACROSS THE REGION THIS EARLY EVENING BUT A DETERIORATION OF BOTH LOWER CEILINGS AND VISIBILITY ARE EXPECTED OVERNIGHT FOR ALL TERMINALS. LOW-LEVEL MOISTURE WILL INCREASE OVERNIGHT AND WITH COOLING TEMPERATURES A SOLID SET-UP FOR BOTH IFR AND LIFR CONDITIONS WILL OCCUR. EXPECT CIGS TO GET DOWN TO 200- 500FTAND POCKETS OF VISIBILITIES REDUCING TO 1-2SM WITH SOME LOCALIZED LOWER SPOTS. HAVE MOVED UP TIMING OF LOW CLOUD AND FOG DEVELOPMENT IN THE IFR/LIFR RANGE FOR KSAT/KSSF TO NEAR 07Z. KAUS SHOULD FOLLOW SUITE BY 09Z WITH KDRT FALLING TO IFR/LIFR IN THE 09- 10Z RANGE. HRRR AND BUFR SOUNDING GUIDANCE SUGGEST POCKETS OF VLIFR CIGS COULD EVEN BE POSSIBLE FOR THE KSAT/KSSF TERMINALS. A GRADUAL IMPROVEMENT WILL OCCUR THROUGH MID MORNING HOURS THURSDAY BUT LOW CLOUDS WILL HOLD ON LONGER THEN PREVIOUS DAYS. ALL SITES SHOULD MIX OUT TO VFR BY EARLY AFTERNOON. SURFACE WINDS WILL ALSO BECOME GUSTY FROM THE SOUTH AT 15-20 KT WITH SOME GUSTS HAS HIGH AS 30 KT GIVEN A TIGHT PRESSURE GRADIENT AND STRONG VERTICAL MIXING. && .PREV DISCUSSION... /ISSUED 304 PM CST WED FEB 17 2016/ SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... INCREASING SOUTHERLY FLOW IN THE LOW-LEVELS WILL RESULT IN MOIST AIR ADVECTION ACROSS SOUTH CENTRAL TEXAS TONIGHT. THE INCREASED MOISTURE WILL RESULT IN LOW CLOUD DEVELOPMENT ALONG WITH ABOVE NORMAL OVERNIGHT LOWS ACROSS ALL AREAS. WE ALSO EXPECT PATCHY FOG TO DEVELOP ACROSS MOST OF SOUTH CENTRAL TEXAS LATE TONIGHT INTO MID-MORNING THURSDAY. SOUTHERLY WINDS AND MIXING WILL DISSIPATE THE FOG AND LOW CLOUDS ON THURSDAY...LEAVING MOSTLY SUNNY SKIES AND ANOTHER DAY OF ABOVE NORMAL HIGH TEMPERATURES THURSDAY AFTERNOON. LONG TERM (FRIDAY THROUGH WEDNESDAY)... SOUTHERLY FLOW IN THE LOW-LEVELS ALONG WITH WESTERLY FLOW ALOFT WILL REMAIN DOMINANT ACROSS THE REGION THROUGH THE WEEKEND INTO EARLY NEXT WEEK. THE MEDIUM RANGE MODELS DO SHOW SOME FAST MOVING MID-LEVEL SHORTWAVES MOVING THROUGH TEXAS ON SUNDAY. RAIN CHANCES WILL REMAIN LOW IN THIS PATTERN AND WE/LL ONLY MENTION A 20% CHANCE FOR PRECIPITATION AT THIS TIME. WE DID INCLUDE A MENTION OF THUNDERSTORMS ACROSS THE SOUTHERN EDWARDS PLATEAU AND PORTIONS OF THE HILL COUNTRY AS THE GFS SHOWS A COLD FRONT MOVING IN DURING THE LATE AFTERNOON OR EARLY EVENING HOURS. THE COLD FRONT APPEARS TO SLOW IT/S SOUTHWARD PROGRESS ON MONDAY AS THE FLOW ALOFT TRANSITIONS TO NORTHWESTERLY. WITH A BOUNDARY IN THE AREA AND AN INCREASINGLY ACTIVE NORTHWEST FLOW ALOFT...WE/LL MENTION A 20-50% CHANCE OF RAIN FOR THE REGION SUNDAY NIGHT AND MONDAY. A REINFORCING SURGE OF HIGH PRESSURE WILL MOVE SOUTHWARD INTO THE SOUTHERN U.S. PLAINS MONDAY NIGHT. THIS WILL USHER THE COLD FRONT SOUTHWARD ON TUESDAY AND KEEP ANY RAIN CHANCES LIMITED TO AREAS GENERALLY ALONG AND EAST OF HIGHWAY 281. RAINFALL AMOUNTS APPEAR FAIRLY LOW AT THIS TIME AND WILL KEEP AMOUNTS AT OR BELOW ONE QUARTER INCH. ON TUESDAY...GUSTY NORTH WINDS SPREAD ACROSS ALL AREAS BEHIND THE COLD FRONT. TEMPERATURES WILL DROP CLOSER TO CLIMATOLOGICAL NORMALS ON TUESDAY AND WEDNESDAY AS DRY WEATHER RETURNS TO THE REGION. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 53 78 60 81 59 / 0 - - - 10 AUSTIN BERGSTROM INTL AIRPORT 47 79 57 79 57 / 0 - - 10 10 NEW BRAUNFELS MUNI AIRPORT 50 80 56 80 57 / 0 - - 10 10 BURNET MUNI AIRPORT 49 77 56 79 56 / 0 0 0 0 - DEL RIO INTL AIRPORT 56 80 56 82 58 / 0 - 0 - 0 GEORGETOWN MUNI AIRPORT 50 77 58 79 58 / 0 - - - - HONDO MUNI AIRPORT 51 81 53 84 56 / - - - 10 10 SAN MARCOS MUNI AIRPORT 49 79 56 80 57 / 0 - - 10 10 LA GRANGE - FAYETTE REGIONAL 50 80 60 79 60 / 0 - - 10 - SAN ANTONIO INTL AIRPORT 53 79 57 81 58 / 0 - - 10 10 STINSON MUNI AIRPORT 52 81 56 82 58 / 0 - - 10 10 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...ALLEN SYNOPTIC/GRIDS...TB3 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1057 PM CST MON FEB 15 2016 .DISCUSSION...POSSIBILITY OF FOG DEVELOPMENT DURING THE EARLY MORNING REMAINS OVER COASTAL PLAINS/VCT CROSSROADS...THOUGH COULD REACH FURTHER WEST TOWARDS LRD. LIGHT AND VARIABLE WINDS WITH GENERALLY BECOME MORE EASTERLY THROUGH THE NIGHT. CURRENT FORECAST APPEARS WELL ON TRACK AT THIS TIME...AND ONLY A FEW TWEAKS WERE MADE TO HOURLY GRIDS BASED ON OBS. && .PREV DISCUSSION... /ISSUED 1050 PM CST MON FEB 15 2016/ DISCUSSION...SEE AVIATION SECTION FOR 00Z TAFS. AVIATION...WEAK FRONTAL BOUNDARY REMAINS STALLED ALONG THE COAST. THE SURFACE RIDGE BEHIND THE BOUNDARY WILL WEAKEN AND SHIFT TO THE NORTH TONIGHT. DEWPOINT TEMPS ARE IN THE LOWER 60S ALONG A CORPUS NAS TO BAFFIN BAY LINE. WINDS WILL VEER NORTHEAST AND EAST IN THE OVERNIGHT HOURS. HI-RES NMM AND RAP CONTINUE TO SHOW DENSE FOG AS A POSSIBILITY FROM NGP TO NQI TO HBV. ALI AND CRP WILL BE ON THE BORDER ON WHETHER THIS HIGHER BOUNDARY LAYER MOISTURE WILL REACH THIS AREA FOR DENSE FOG TO FORM. MOS GUIDANCE DEPICTS HIGHER PROBABILITY OF FOG WHILE THE FORECAST SOUNDINGS SHOW DRIER AIR SHOULD LIMIT FOG FORMATION. FOR NOW...WILL SHOW FOG WITH MVFR VSBYS AT ALI AND CRP FROM 09-10Z THROUGH 15Z WITH TEMPO FOR IFR VSBYS. RAP AND HI-RES NMM SHOW DENSE FOG OVER DEEP SOUTH TEXAS MAY ADVECT NORTHWEST TOWARD LAREDO AROUND DAYBREAK. KEPT TEMPO GROUP FOR 3SM VSBY FROM 12-16Z. VICTORIA AREA SHOULD BE IN REGION OF LOWER BOUNDARY LAYER MOISTURE BUT COULD SEE FOG FORM BEFORE DAYBREAK. PLACED A TEMPO GROUP FROM 09-13Z FOR MVFR VSBYS AT VCT. VFR/CLEAR SKIES WITH LIGHT SOUTH TO SOUTHWEST WINDS ARE EXPECTED AFTER 16Z. HIGHER BOUNDARY LAYER MOISTURE WILL MOVE INTO THE COASTAL PLAINS TUESDAY EVENING AND EXPECT FOG/MVFR VSBYS TO OCCUR FOR ALI/CRP/VCT BY 03-04Z. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 82 49 83 55 81 / 0 0 0 0 0 VICTORIA 78 45 80 50 80 / 10 0 0 0 0 LAREDO 83 51 85 57 88 / 0 0 0 0 0 ALICE 84 47 85 52 83 / 0 0 0 0 0 ROCKPORT 76 56 77 55 73 / 10 0 0 0 0 COTULLA 84 47 83 51 86 / 0 0 0 0 0 KINGSVILLE 83 47 82 51 82 / 0 0 0 0 0 NAVY CORPUS 78 58 77 60 74 / 10 0 0 0 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ LK/84...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1050 PM CST MON FEB 15 2016 .DISCUSSION...SEE AVIATION SECTION FOR 00Z TAFS. && .AVIATION...WEAK FRONTAL BOUNDARY REMAINS STALLED ALONG THE COAST. THE SURFACE RIDGE BEHIND THE BOUNDARY WILL WEAKEN AND SHIFT TO THE NORTH TONIGHT. DEWPOINT TEMPS ARE IN THE LOWER 60S ALONG A CORPUS NAS TO BAFFIN BAY LINE. WINDS WILL VEER NORTHEAST AND EAST IN THE OVERNIGHT HOURS. HI-RES NMM AND RAP CONTINUE TO SHOW DENSE FOG AS A POSSIBILITY FROM NGP TO NQI TO HBV. ALI AND CRP WILL BE ON THE BORDER ON WHETHER THIS HIGHER BOUNDARY LAYER MOISTURE WILL REACH THIS AREA FOR DENSE FOG TO FORM. MOS GUIDANCE DEPICTS HIGHER PROBABILITY OF FOG WHILE THE FORECAST SOUNDINGS SHOW DRIER AIR SHOULD LIMIT FOG FORMATION. FOR NOW...WILL SHOW FOG WITH MVFR VSBYS AT ALI AND CRP FROM 09-10Z THROUGH 15Z WITH TEMPO FOR IFR VSBYS. RAP AND HI-RES NMM SHOW DENSE FOG OVER DEEP SOUTH TEXAS MAY ADVECT NORTHWEST TOWARD LAREDO AROUND DAYBREAK. KEPT TEMPO GROUP FOR 3SM VSBY FROM 12-16Z. VICTORIA AREA SHOULD BE IN REGION OF LOWER BOUNDARY LAYER MOISTURE BUT COULD SEE FOG FORM BEFORE DAYBREAK. PLACED A TEMPO GROUP FROM 09-13Z FOR MVFR VSBYS AT VCT. VFR/CLEAR SKIES WITH LIGHT SOUTH TO SOUTHWEST WINDS ARE EXPECTED AFTER 16Z. HIGHER BOUNDARY LAYER MOISTURE WILL MOVE INTO THE COASTAL PLAINS TUESDAY EVENING AND EXPECT FOG/MVFR VSBYS TO OCCUR FOR ALI/CRP/VCT BY 03-04Z. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 49 83 55 81 58 / 0 0 0 0 0 VICTORIA 45 80 50 80 53 / 0 0 0 0 0 LAREDO 51 85 57 88 57 / 0 0 0 0 0 ALICE 47 85 52 83 56 / 0 0 0 0 0 ROCKPORT 56 77 55 73 60 / 0 0 0 0 0 COTULLA 47 83 51 86 55 / 0 0 0 0 0 KINGSVILLE 47 82 51 82 56 / 0 0 0 0 0 NAVY CORPUS 58 77 60 74 61 / 0 0 0 0 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ TMT/89...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
903 PM EST WED FEB 17 2016 .SYNOPSIS... A WEAK COLD FRONT WILL CROSS INTO THE MOUNTAINS OVERNIGHT BEFORE DISSIPATING BY THURSDAY MORNING. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND WILL COVER MUCH OF THE EASTERN UNITED STATES ON THURSDAY. A LOW PRESSURE SYSTEM IN THE UPPER MISSISSIPPI VALLEY FRIDAY WILL MOVE EAST ACROSS THE GREAT LAKES ON SATURDAY. && .NEAR TERM /THROUGH THURSDAY/... AS OF 840 PM EST WEDNESDAY... SOUNDINGS SHOW RATHER DEEP LOW LEVEL MOISTURE OVER THE MOUNTAINS THIS EVENING WITH A MOIST LAYER UNDER THE INVERSION ALOFT BETWEEN THE SURFACE AND 8H. THIS WITHIN A LAYER OF DECENT NW FLOW AHEAD OF A WEAK SURFACE COLD FRONT IN THE OHIO VALLEY THAT WILL BASICALLY DISSIPATE CROSSING THE REGION OVERNIGHT. AHEAD OF THE BOUNDARY HAVE SEEN JUST ENOUGH LIFT UNDER THE UPSLOPE FLOW TO PRODUCE A FEW SMALL BANDS OF FLURRIES AND SNOW SHOWERS OVER THE WEST BUT QUITE LIGHT/SPOTTY AT THIS POINT. THUS HAVE INCLUDED SOME ADDED LOW POPS OUT TOWARD THE NEW RIVER VALLEY AND THE HIGH COUNTRY OF NW NORTH CAROLINA UNTIL AROUND MIDNIGHT PER THE EARLIER 4KM NAM OUTPUT. EXPECT MORE DRYING TO DEVELOP FROM THE NORTH LATER TONIGHT AS HIGH PRESSURE BUILDS JUST NORTH OF THE REGION AND ADDED SUBSIDENCE SLOWLY ACTS TO DIMINISH THE LOW LEVEL MOISTURE. HOWEVER BEFORE THIS OCCURS MAY SEE SOME LOW CLOUDS SPILL OUT EAST OF THE BLUE RIDGE GIVEN THE DECENT NW JET WHILE STILL EXPECT THE LOW DECK TO PERSIST FAR WEST A BIT LONGER. THEREFORE BUMPED UP CLOUDS SOME MAINLY OVER THE NEXT FEW HOURS FROM THE BLUE RIDGE WESTWARD. LINGERING CLOUDS AND MIXING MAY ALSO ACT TO HOLD TEMPS UP AS THE LATEST LAMP QUITE A BIT WARMER PROVIDED CLOUDS REMAIN IN PLACE. SINCE THINK MORE BREAKS MAY DEVELOP WONT RAISE LOWS MORE THAN A CATEGORY ESPCLY GIVEN GRADUAL FILTERING IN OF WEAK COLD ADVECTION OVERNIGHT. PREVIOUS DISCUSSION AS OF 200 PM EST WEDNESDAY... A SHORTWAVE LOCATED IN KENTUCKY AROUND 18Z WILL ROTATE EAST AROUND THE BASE OF THE UPPER TROUGH THIS AFTERNOON INTO TONIGHT. THE UPPER TROF AXIS IS FORECAST TO PIVOT NORTHEAST TONIGHT...ALLOWING SOME RIDGING AND RISING 500 MB HEIGHTS. SFC COLD FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON WILL WEAKEN AND DISSIPATE OVER THE MID ATLANTIC REGION BY THURSDAY MORNING. THE HIRESW-ARW-E...RNK- WRFARW...GFS AND NAM SHOWED ISOLATED SCATTERED SHOWERS ACROSS THE WESTERN MOUNTAINS. THE ECMWF...RAP AND HRRR ARE LESS IMPRESSED FOR ACTIVITY. FOR TONIGHT...WILL MAINTAIN SCATTERED SNOW SHOWERS IN THE WESTERN MOUNTAINS. ANY SNOW ACCUMULATIONS WILL BE LIGHT AND LESS THAN AN INCH. THE BEST CHANCE OF SNOW WILL OCCUR ALONG THE WESTERN SLOPES OF GREENBRIER COUNTY OF WEST VIRGINIA. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MID TEENS IN THE NORTHWEST MOUNTAINS TO THE MID 20S IN THE SOUTHEAST. ANY LINGERING MOUNTAIN SNOW SHOWERS AND SNOW FLURRIES SHOULD BE GONE THURSDAY MORNING...AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. SOME LINGERING STRATOCUMULUS CLOUDS MAY STILL PERSIST UNTIL THE AFTERNOON WEST OF THE BLUE RIDGE...WHEN THE HIGH BUILDS OVERHEAD. EAST OF THE BLUE RIDGE...LOOK FOR PLENTY OF SUNSHINE. HIGH TEMPERATURES WILL VARY FROM THE LOWER 30S IN THE NORTHWEST MOUNTAINS TO THE UPPER 40S IN THE PIEDMONT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... AS OF 245 PM EST WEDNESDAY A CLASSIC WEDGE WILL TAKE RESIDENCE OVER THE EAST COAST THURSDAY NIGHT INTO FRIDAY. THE MID ATLANTIC PORTION OF THE WEDGE WILL DRIFT OUT TO SEA AS A NORTHERN STREAM DISTURBANCE TRACKS EAST OF THE GREAT LAKES FRIDAY NIGHT. THIS DISTURBANCE WILL PUSH A WEAK COLD FRONT OVER THE AREA EARLY SATURDAY. THE SOUTHERN PORTION OF THIS WEDGE WILL REMAIN OVER THE SOUTHEASTERN US WHILE BLOCKING THE GULF. THE FRONT COMING ACROSS EARLY SATURDAY WILL BE MOISTURE STARVED WITH A FEW LIGHT RAIN SHOWERS HITTING THE WESTERN SLOPES AND ONLY AN INCREASE IN CLOUDS ELSEWHERE. ZONAL FLOW BECOMES ESTABLISHED BY SATURDAY AFTERNOON AND WILL REMAIN THROUGH THE WEEKEND. BEING AHEAD OF THE FRONT FRIDAY...TEMPERATURES WILL WARM AT OR ABOVE NORMAL WITH READINGS IN THE M/U 40S WEST TO L50S EAST. DESPITE THE PASSING OF A WEAK FRONT SATURDAY MORNING...TEMPERATURES WILL MODERATE WARMER THAN NORMAL WITH WIDESPREAD 50S ACROSS THE AREA TO THE LOWER 60S IN THE PIEDMONT. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 115 PM EST WEDNESDAY THE NORTHERN AND SOUTHERN STREAMS WILL REMAIN SEPARATED THROUGH THE WEEKEND. DISTURBANCES IN THE NORTHERN STREAM WILL TRACK EAST FROM THE GREAT LAKES TO NORTHEASTERN US. ACROSS THE SOUTH...A STALLED BOUNDARY WILL KEEP RAIN FROM EASTERN TEXAS TO SOUTH CAROLINA. FOR THE IMMEDIATE AREA...A WEAK MOISTURE STARVED FRONT WILL PASS OVER THE REGION FRIDAY NIGHT INTO SATURDAY MORNING. SOME LIGHT PRECIPITATION MAY FALL ALONG WESTERN SLOPES...DRY ELSEWHERE. WITH ZONAL FLOW OVER THE WEEKEND...TEMPERATURES WILL WARM INTO THE 50S AND 60S. ON MONDAY...THE NORTHERN STREAM WILL SEND AN UPPER LEVEL TROUGH ACROSS THE PLAINS. WAVES OF LOW PRESSURE WILL FORM AND TRACK ALONG THE STALLED BOUNDARY ACROSS THE SOUTHERN STATES. MONDAY NIGHT INTO TUESDAY...MODEL GUIDANCE IS NOT IN AGREEMENT WITH TIMING OF THE NEXT LOW PRESSURE SYSTEM BRINGING POTENTIAL FOR RAIN AND SNOW TO THE AREA. A HIGH PRESSURE WEDGES DOWN ALONG THE EASTERN SLOPES OF THE BLUE RIDGE MONDAY EVENING. THE STRENGTH OF THE WEDGE WILL DEPEND ON WHAT TYPE OF PRECIP TO EXPECT OVERNIGHT. THE WEDGE MOVES OUT QUICKLY TUESDAY MORNING RETURNING TO RAIN BY THE AFTERNOON. THE UPPER LEVEL TROUGH DEEPENS THROUGH THE TENNESSEE VALLEY IT BECOMES NEGATIVE-TILTED WITH CONVECTIVE SHOWERS TRACKING EAST OF THE BLUE RIDGE TO THE COASTAL PIEDMONT. TEMPERATURES WILL REMAIN WELL ABOVE NORMAL MONDAY AND TUESDAY FOR ALL PRECIPITATION TO STAY LIQUID. THE FRONT WILL PASS TO THE EAST TUESDAY NIGHT...WITH UPSLOPE SNOW SHOWERS LIKELY INTO WEDNESDAY MORNING...ALL PRECIP SHOULD EXIT THE REGION BY WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS IN. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... AS OF 545 PM EST WEDNESDAY... WEAK PUSH OF LOW LEVEL COLD ADVECTION ON NW WINDS WILL CONTINUE TO CREATE MVFR TO IFR CIGS OVER THE WEST TONIGHT WITH SOME OF THIS CANOPY SPILLING OVER EAST OF THE BLUE RIDGE BUT MAINLY IN VFR FASHION. COULD SEE SOME IMPROVEMENT AT TIMES AS CLOUD BASES SCATTER OUT AT TIMES BUT OVERALL SUB-VFR FROM KBCB WESTWARD FOR MUCH OF THE OVERNIGHT. ANY RAIN/SNOW SHOWERS ALSO LOOK QUITE ISOLATED AND ALTHOUGH CANT RULE OUT A BRIEF VSBY REDUCTION IN SOME SPOTTY LIGHT PRECIP...NOT ENOUGH TO INCLUDE MENTION FOR NOW. ON THURSDAY...HIGH PRESSURE WILL MOVE OVER AND TO THE NORTH OF THE REGION ALLOWING DRYING FROM ALOFT TO GRADUALLY MIX OUT RESIDUAL LOWER CIGS OVER THE MOUNTAINS. HOWEVER MAY TAKE UNTIL LATE IN THE DAY TO BRING KBLF/KLWB BACK TO VFR...WITH SPOTS LIKE KBCB IMPROVING BY MIDDAY. ELSEWHERE EXPECTING MAINLY VFR UNDER SOME SHEARED HIGH LEVELS CLOUDS. SHOULD SEE ALL SITES REMAIN VFR THURSDAY NIGHT WITH AGAIN JUST SOME HIGH CLOUDS AROUND. EXTENDED DISCUSSION... VFR CONDITIONS PREVAIL AT ALL SITES THROUGH FRIDAY AS HIGH PRESSURE REPOSITIONS TO OFF THE CAROLINAS ALLOWING RETURN SW FLOW TO DEVELOP. ANOTHER LOW PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY. IT COULD SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS ON FRIDAY NIGHT AND SATURDAY AS A WEAK SURFACE TROUGH PASSES THROUGH. A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY AND SLIDE THROUGH THE REGION LATER SUNDAY NIGHT INTO MONDAY BEFORE SETTLING JUST SOUTH OF THE AREA. THIS COULD BRING A PERIOD OF SUB-VFR INCLUDING A FEW SHOWERS FROM LATE SUNDAY INTO SUNDAY NIGHT...AND OVER SOUTHERN SECTIONS ON MONDAY. OTHERWISE MAINLY VFR GIVEN FUTURE UNCERTAINTY WITH TIMING OF THESE FEATURES. && .HYDROLOGY... AS OF 815 PM EST WEDNESDAY... STAGES ARE FALLING ON THE UPPER DAN RIVER FROM DANVILLE UPSTREAM BUT CONTINUING TO SLOWLY RISE DOWNSTREAM. HOWEVER PACES ALONG THE DAN IS EXPECTED TO CREST IN THE NEXT FEW HOURS BEFORE FALLING BELOW FLOOD STAGE BY EARLY THURSDAY MORNING. LEVELS WILL CONTINUE TO SLIDE UPWARD AT SOUTH BOSTON WITH A CREST DURING THURSDAY MORNING. EXPECT MINOR FLOODING OF LOWLAND AREAS. STAGES ALSO CONTINUE TO CLIMB ALONG THE LOWER ROANOKE RIVER AT RANDOLPH WHICH WILL MAINLY IMPACT LOWLANDS AND SEVERAL ROADS NEAR THE RIVER. RANDOLPH IS EXPECTED TO CREST OVERNIGHT BUT REMAIN ABOVE FLOOD STAGE UNTIL LATE THURSDAY. THUS FLOOD WARNINGS CONTINUE FOR THE ROANOKE RIVER AT RANDOLPH AFFECTING CHARLOTTE AND HALIFAX COUNTIES...AS WELL AS THE DAN RIVER AT PACES AND SOUTH BOSTON AFFECTING HALIFAX COUNTY. CHECK THE LATEST WBCFLSRNK FOR ADDED DETAILS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/KK NEAR TERM...JH/KK SHORT TERM...RCS LONG TERM...RCS AVIATION...AMS/JH/KK HYDROLOGY...JH/KK/PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
605 PM EST WED FEB 17 2016 .SYNOPSIS... A COLD FRONT WILL CROSS THROUGH THE OHIO VALLEY TONIGHT...THEN WILL DISSIPATE OVER THE MID ATLANTIC REGION BY THURSDAY MORNING. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND WILL COVER MUCH OF THE EASTERN UNITED STATES ON THURSDAY. A LOW PRESSURE SYSTEM IN THE UPPER MISSISSIPPI VALLEY FRIDAY WILL MOVE EAST ACROSS THE GREAT LAKES ON SATURDAY. && .NEAR TERM /THROUGH THURSDAY/... AS OF 200 PM EST WEDNESDAY... A SHORTWAVE LOCATED IN KENTUCKY AROUND 18Z WILL ROTATE EAST AROUND THE BASE OF THE UPPER TROUGH THIS AFTERNOON INTO TONIGHT. THE UPPER TROF AXIS IS FORECAST TO PIVOT NORTHEAST TONIGHT...ALLOWING SOME RIDGING AND RISING 500 MB HEIGHTS. SFC COLD FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON WILL WEAKEN AND DISSIPATE OVER THE MID ATLANTIC REGION BY THURSDAY MORNING. THE HIRESW-ARW-E...RNK- WRFARW...GFS AND NAM SHOWED ISOLATED SCATTERED SHOWERS ACROSS THE WESTERN MOUNTAINS. THE ECMWF...RAP AND HRRR ARE LESS IMPRESSED FOR ACTIVITY. FOR TONIGHT...WILL MAINTAIN SCATTERED SNOW SHOWERS IN THE WESTERN MOUNTAINS. ANY SNOW ACCUMULATIONS WILL BE LIGHT AND LESS THAN AN INCH. THE BEST CHANCE OF SNOW WILL OCCUR ALONG THE WESTERN SLOPES OF GREENBRIER COUNTY OF WEST VIRGINIA. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MID TEENS IN THE NORTHWEST MOUNTAINS TO THE MID 20S IN THE SOUTHEAST. ANY LINGERING MOUNTAIN SNOW SHOWERS AND SNOW FLURRIES SHOULD BE GONE THURSDAY MORNING...AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. SOME LINGERING STRATOCUMULUS CLOUDS MAY STILL PERSIST UNTIL THE AFTERNOON WEST OF THE BLUE RIDGE...WHEN THE HIGH BUILDS OVERHEAD. EAST OF THE BLUE RIDGE...LOOK FOR PLENTY OF SUNSHINE. HIGH TEMPERATURES WILL VARY FROM THE LOWER 30S IN THE NORTHWEST MOUNTAINS TO THE UPPER 40S IN THE PIEDMONT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... AS OF 245 PM EST WEDNESDAY A CLASSIC WEDGE WILL TAKE RESIDENCE OVER THE EAST COAST THURSDAY NIGHT INTO FRIDAY. THE MID ATLANTIC PORTION OF THE WEDGE WILL DRIFT OUT TO SEA AS A NORTHERN STREAM DISTURBANCE TRACKS EAST OF THE GREAT LAKES FRIDAY NIGHT. THIS DISTURBANCE WILL PUSH A WEAK COLD FRONT OVER THE AREA EARLY SATURDAY. THE SOUTHERN PORTION OF THIS WEDGE WILL REMAIN OVER THE SOUTHEASTERN US WHILE BLOCKING THE GULF. THE FRONT COMING ACROSS EARLY SATURDAY WILL BE MOISTURE STARVED WITH A FEW LIGHT RAIN SHOWERS HITTING THE WESTERN SLOPES AND ONLY AN INCREASE IN CLOUDS ELSEWHERE. ZONAL FLOW BECOMES ESTABLISHED BY SATURDAY AFTERNOON AND WILL REMAIN THROUGH THE WEEKEND. BEING AHEAD OF THE FRONT FRIDAY...TEMPERATURES WILL WARM AT OR ABOVE NORMAL WITH READINGS IN THE M/U 40S WEST TO L50S EAST. DESPITE THE PASSING OF A WEAK FRONT SATURDAY MORNING...TEMPERATURES WILL MODERATE WARMER THAN NORMAL WITH WIDESPREAD 50S ACROSS THE AREA TO THE LOWER 60S IN THE PIEDMONT. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 115 PM EST WEDNESDAY THE NORTHERN AND SOUTHERN STREAMS WILL REMAIN SEPARATED THROUGH THE WEEKEND. DISTURBANCES IN THE NORTHERN STREAM WILL TRACK EAST FROM THE GREAT LAKES TO NORTHEASTERN US. ACROSS THE SOUTH...A STALLED BOUNDARY WILL KEEP RAIN FROM EASTERN TEXAS TO SOUTH CAROLINA. FOR THE IMMEDIATE AREA...A WEAK MOISTURE STARVED FRONT WILL PASS OVER THE REGION FRIDAY NIGHT INTO SATURDAY MORNING. SOME LIGHT PRECIPITATION MAY FALL ALONG WESTERN SLOPES...DRY ELSEWHERE. WITH ZONAL FLOW OVER THE WEEKEND...TEMPERATURES WILL WARM INTO THE 50S AND 60S. ON MONDAY...THE NORTHERN STREAM WILL SEND AN UPPER LEVEL TROUGH ACROSS THE PLAINS. WAVES OF LOW PRESSURE WILL FORM AND TRACK ALONG THE STALLED BOUNDARY ACROSS THE SOUTHERN STATES. MONDAY NIGHT INTO TUESDAY...MODEL GUIDANCE IS NOT IN AGREEMENT WITH TIMING OF THE NEXT LOW PRESSURE SYSTEM BRINGING POTENTIAL FOR RAIN AND SNOW TO THE AREA. A HIGH PRESSURE WEDGES DOWN ALONG THE EASTERN SLOPES OF THE BLUE RIDGE MONDAY EVENING. THE STRENGTH OF THE WEDGE WILL DEPEND ON WHAT TYPE OF PRECIP TO EXPECT OVERNIGHT. THE WEDGE MOVES OUT QUICKLY TUESDAY MORNING RETURNING TO RAIN BY THE AFTERNOON. THE UPPER LEVEL TROUGH DEEPENS THROUGH THE TENNESSEE VALLEY IT BECOMES NEGATIVE-TILTED WITH CONVECTIVE SHOWERS TRACKING EAST OF THE BLUE RIDGE TO THE COASTAL PIEDMONT. TEMPERATURES WILL REMAIN WELL ABOVE NORMAL MONDAY AND TUESDAY FOR ALL PRECIPITATION TO STAY LIQUID. THE FRONT WILL PASS TO THE EAST TUESDAY NIGHT...WITH UPSLOPE SNOW SHOWERS LIKELY INTO WEDNESDAY MORNING...ALL PRECIP SHOULD EXIT THE REGION BY WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS IN. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AS OF 545 PM EST WEDNESDAY... WEAK PUSH OF LOW LEVEL COLD ADVECTION ON NW WINDS WILL CONTINUE TO CREATE MVFR TO IFR CIGS OVER THE WEST TONIGHT WITH SOME OF THIS CANOPY SPILLING OVER EAST OF THE BLUE RIDGE BUT MAINLY IN VFR FASHION. COULD SEE SOME IMPROVEMENT AT TIMES AS CLOUD BASES SCATTER OUT AT TIMES BUT OVERALL SUB-VFR FROM KBCB WESTWARD FOR MUCH OF THE OVERNIGHT. ANY RAIN/SNOW SHOWERS ALSO LOOK QUITE ISOLATED AND ALTHOUGH CANT RULE OUT A BRIEF VSBY REDUCTION IN SOME SPOTTY LIGHT PRECIP...NOT ENOUGH TO INCLUDE MENTION FOR NOW. ON THURSDAY...HIGH PRESSURE WILL MOVE OVER AND TO THE NORTH OF THE REGION ALLOWING DRYING FROM ALOFT TO GRADUALLY MIX OUT RESIDUAL LOWER CIGS OVER THE MOUNTAINS. HOWEVER MAY TAKE UNTIL LATE IN THE DAY TO BRING KBLF/KLWB BACK TO VFR...WITH SPOTS LIKE KBCB IMPROVING BY MIDDAY. ELSEWHERE EXPECTING MAINLY VFR UNDER SOME SHEARED HIGH LEVELS CLOUDS. SHOULD SEE ALL SITES REMAIN VFR THURSDAY NIGHT WITH AGAIN JUST SOME HIGH CLOUDS AROUND. EXTENDED DISCUSSION... VFR CONDITIONS PREVAIL AT ALL SITES THROUGH FRIDAY AS HIGH PRESSURE REPOSITIONS TO OFF THE CAROLINAS ALLOWING RETURN SW FLOW TO DEVELOP. ANOTHER LOW PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY. IT COULD SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS ON FRIDAY NIGHT AND SATURDAY AS A WEAK SURFACE TROUGH PASSES THROUGH. A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY AND SLIDE THROUGH THE REGION LATER SUNDAY NIGHT INTO MONDAY BEFORE SETTLING JUST SOUTH OF THE AREA. THIS COULD BRING A PERIOD OF SUB-VFR INCLUDING A FEW SHOWERS FROM LATE SUNDAY INTO SUNDAY NIGHT...AND OVER SOUTHERN SECTIONS ON MONDAY. OTHERWISE MAINLY VFR GIVEN FUTURE UNCERTAINTY WITH TIMING OF THESE FEATURES. && .HYDROLOGY... AS OF 1252 PM EST TUESDAY... STAGES ARE FALLING ON THE UPPER DAN RIVER FROM DANVILLE UPSTREAM BUT CONTINUING TO RISE DOWNSTREAM. EXPECT MINOR FLOODING OF LOWLAND AREAS. STAGES ALSO CONTINUE TO CLIMB ALONG THE LOWER ROANOKE RIVER IMPACTING LOWLANDS AND SEVERAL ROADS NEAR THE RIVER. FLOOD WARNING CONTINUES FOR THE FOLLOWING RIVERS IN VIRGINIA...ROANOKE RIVER AT RANDOLPH AFFECTING CHARLOTTE AND HALIFAX COUNTIES, DAN RIVER AT PACES AFFECTING HALIFAX COUNTY AND DAN RIVER AT SOUTH BOSTON AFFECTING HALIFAX COUNTY. CHECK LATEST FLS FOR FLOOD DETAILS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...KK SHORT TERM...RCS LONG TERM...RCS AVIATION...AMS/JH/KK HYDROLOGY...KK/PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1248 PM EST TUE FEB 16 2016 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES WILL MOVE NORTHEAST INTO CANADA BY THIS EVENING. ANOTHER LOW OVER THE CENTRAL PLAINS WILL TRACK INTO THE TENNESSEE VALLEY BY THIS EVENING...THEN OFFSHORE BY WEDNESDAY MORNING. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST LATE WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1050 AM EST TUESDAY... WINTER STORM WATCH CANCELED FOR REST OF FORECAST AREA. THE RAIN HAS LIFTED TO THE NORTH THIS MORNING. WIDESPREAD FREEZING RAIN HAS ENDED THIS MORNING FOR THE AREA. TEMPERATURES ARE RISING AND HAVE CLIMB INTO THE MID AND UPPER 30S FOR MOST OF THE REGION. HOWEVER...ROADS REMAIN SNOW AND ICE COVERED IN MANY LOCATIONS. MADE SOME ADJUSTMENTS IN TEMPERATURES FOR THIS MORNING CLOSER TO SURFACE OBS AND TRENDED THE LATE MORNING READINGS TOWARDS A BLEND OF HRRR AND NAM. LEANED POPS FOR LATE MORNING INTO THIS AFTERNOON TOWARDS THE HRRR AND USED WEATHER TOOL WITH NAM PROFILE. MORE CHANGES LATER TODAY. AS OF 330 AM EST TUESDAY... UPPER LOW FROM KENTUCKY THROUGH GEORGIA WILL MOVE QUICKLY NORTHEAST THIS MORNING. BROAD BAND OF SHOWERS WITH THE UPPER LOW THAT EXTENDS SOUTH INTO FLORIDA WILL ALSO MOVE NORTHEAST. EXPECT THE WESTERN EDGE OF THIS PRECIPITATION TO EXIT THE EASTERN COUNTY WARNING AREA AROUND NOON. HRRR HAS THIS BEST TIMING OF THIS BAND OF PRECIPITATION SO WILL LEAN TOWARDS THIS TIMING IN THE FORECAST. THE SHORT WAVE OVER THE DAKOTAS WILL TRACK INTO THE TENNESSEE VALLEY BY 00Z WED/7PM THIS EVENING...THEN WILL MOVE EAST ACROSS NORTH CAROLINA. MODELS CONTINUED TO SHOW SOME Q-VECTOR FORCING AND GOOD UPPER DIFFLUENCE WITH THIS FEATURE THIS EVENING. TEMPERATURES IN THE WARM NOSE AROUND 2500 FEET AGL WERE WELL INTO THE 40S AND 50S. ALREADY SEEING SOME OF THE WARMER AIR MIXING DOWN TO THE SURFACE WITH THE HIGHER RAINFALL RATES. AT THE SAME TIME THE WEDGE WAS ERODING FROM BOTH THE EAST AND THE WEST. COLD AIR DAMMING WILL BE NEARLY GONE BY 8AM...WITH ALL LOCATIONS NOT IN THE WEDGE ABOVE FREEZING AT THE SURFACE. COLDER AIR FROM 850MB DOWN TO THE SURFACE WILL COME INTO THE MOUNTAINS BEHIND THE UPPER LOW THIS AFTERNOON THEN REMAIN BETWEEN -2 TO -5 AT 850 MB OVERNIGHT. TEMPERATURES WILL FOLLOW A NON DIURNAL TREND TODAY. LOCATIONS THAT ARE ABOVE FREEZING WILL BE REMOVED FROM THE WINTER STORM WARNING. AS THE COASTAL FRONT MOVES EAST AND AIDES IN ERODE THE EASTERN SIDE OF THE WEDGE...THE MUCH WARMER AIR OVER THE COLD GROUND AND SNOW COVER WILL PRODUCE WIDESPREAD FOG. VISIBILITIES IN SOME LOCATIONS WILL BE LESS THAN ONE HALF MILE. IF THESE AREAL COVERAGE OF THESE CONDITIONS BECOMES WIDESPREAD IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA A DENSE FOG ADVISORY WILL BE ISSUED. BUT AS OF 3AM...THE LEADING EDGE OF THE WARMER AIR WAS JUST MOVING THROUGH RALEIGH. NAM...RAP AND LOCAL WRF SUGGEST THE WARM AIR ADVANCES BRIEFLY INTO THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...JUST BEFORE WINDS SHIFT TO THE WEST AND THE WARM AIR GETS PUSHED BACK EAST. WINDS ARE ANOTHER RAPIDLY CHANGING FACTOR TODAY. ON THE WEST SIDE OF THE WEDGE...DOWNSLOPE SOUTHEAST WINDS WILL PRODUCE WIND GUSTS OF 35 TO 50 MPH...BUT THE BULK OF THE STRONG LOW LEVEL JET THAT WAS PRODUCING THESE HIGHER GUSTS WILL BE MOVING EAST THIS MORNING AND WINDS WILL SHIFT TO THE WEST BY 9AM. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EST TUESDAY... A CLIPPER SYSTEM SHOULD PASS OVERHEAD ON WEDNESDAY...AND MAINTAIN SCATTERED PRECIPITATION ALONG THE WESTERN SLOPES. ALTHOUGH IT MAY START AS SNOW...TEMPERATURES COULD RISE ENOUGH TO ALLOW A MIX WITH RAIN DURING THE AFTERNOON. HOWEVER...THE HIGHEST ELEVATIONS MAY STAY AS SNOW AND ACCUMULATE UP TO A COUPLE INCHES. ELSEWHERE...SOME PASSING CLOUDS AND A BREEZY NORTHWEST WIND SHOULD BE EXPECTED. BY WEDNESDAY NIGHT...SCATTERED SNOW SHOWERS SHOULD GRADUALLY FADE...AS HIGH PRESSURE BUILDS OVERHEAD. AN UPPER LEVEL TROUGH WILL ALSO PUSH THROUGH THE MID ATLANTIC...AND SEND OVERNIGHT LOWS BELOW FREEZING. ALTHOUGH MORE SUNSHINE WILL RETURN BY THURSDAY...A LINGERING NORTHWEST BREEZE SHOULD KEEP COLD AIR ADVECTION CONTINUING THROUGH THE DAY. THE UPPER LEVEL TROUGH SHOULD PULL AWAY FROM THE MID ATLANTIC DURING THURSDAY NIGHT...AND SOME UPPER LEVEL RIDGING SHOULD TAKE PLACE. HOWEVER...CLAM WINDS AND MOSTLY CLEAR SKIES COMBINED WITH ANY REMAINING SNOWPACK...SHOULD SEND LOWS BELOW FREEZING FOR ANOTHER NIGHT. OVERALL...TEMPERATURES WERE HELD ON THE COLDER SIDE OF MOS GUIDANCE THROUGHOUT THIS PERIOD. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 315 PM EST MONDAY RESIDUAL 500 MB TROUGH WILL FINALLY LIFT OUT TO THE NORTHEAST ON THURSDAY AS HEIGHTS START TO BUILD FROM THE WEST AHEAD OF A RATHER POTENT SHORTWAVE AND ASSOCIATED SURFACE LOW THAT WILL BE CROSSING THE GREAT LAKES ON FRIDAY. THIS SHOULD BOOT A SURFACE WARM FRONT THROUGH THE REGION FRIDAY AFTERNOON AS THE LINGERING WEDGE OF SURFACE HIGH PRESSURE TO THE NORTH REPOSITIONS OFF THE CAROLINAS BY LATE FRIDAY. RAPID JUMP IN 85H TEMPERATURES UNDER THE DEVELOPING SHORTWAVE RIDGE LOOKS TO PUSH HIGHS TO JUST ABOVE NORMAL AFTER REMAINING COOL THURSDAY UNDER THE CANADIAN HIGH TO THE NORTH. HOWEVER GIVEN SOME LINGERING SNOW PACK AND EVOLVING TRANSITION OF THE SURFACE HIGH...WILL STAY A BIT BELOW MOS FRIDAY ESPECIALLY EAST. OTHERWISE DRY BUT STILL ON THE COLD SIDE THURSDAY NIGHT THEN WARMER FRIDAY. MAJORITY OF THE NORTHERN STREAM ENERGY WILL PASS TO THE NORTH TO START THE WEEKEND WHILE ALLOWING ITS TRAILING TROUGH AXIS TO FLATTEN THE ONGOING MID LEVEL RIDGING TO SOME DEGREE. THE ASSOCIATED WEAK COLD FRONT SHOULD PRESS ACROSS THE REGION SATURDAY BUT GIVEN VERY LIMITED MOISTURE...AND MOST COLD ADVECTION TO THE NORTH APPEARS ONLY A FEW RAIN SHOWERS POSSIBLE MAINLY FAR WEST. WITH COOL AIR LIKELY TO LAG THE FRONT AND LESS CLOUDS HEADING EAST OF THE MOUNTAINS...WOULD EXPECT TEMPS TO REALLY JUMP UNDER WESTERLY FLOW WITH HIGHS WELL ABOVE NORMAL...MAINLY 50S WEST TO 60S EAST. WEAK BUBBLE HIGH WILL FOLLOW THIS WEAK FRONT ON SUNDAY WITH SKIES CLEARING BEFORE RETURN MOISTURE STARTS TO RETURN LATER IN THE DAY AHEAD OF THE NEXT UPSTREAM TROUGHS. TIMING OF THIS MOISTURE ALONG WITH POTENTIAL FOR A SOUTHERN STREAM WAVE TO PERHAPS SLOW UP THE NEXT FRONT....PER THE EARLIER EC...SUPPORTS MAINLY DRY AND CONTINUED MILD SUNDAY. SLOW RETURN TO EASTERN TROFFINESS APPEARS TO BE IN ORDER BY EARLY NEXT WEEK WITH THIS NEXT FRONT SLIDING ACROSS PRODUCING THE NEED FOR LOW RAIN SHOWER POPS AND SLIGHTLY COOLER TEMPS BUT STILL OVERALL A BIT ABOVE NORMAL FOR DAY 7. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 1248 PM EST TUESDAY... LOW PRESSURE TO OUR NORTH ACROSS PENNSYLVANIA THIS AFTERNOON WILL CONTINUE TO LIFT NORTHEAST TONIGHT INTO WEDNESDAY. WEST TO NORTHWEST WINDS AROUND 10 MPH WITH GUSTS OF 15 TO 30 KNOTS THIS AFTERNOON WILL CONTINUE INTO TONIGHT. A LOW COMING OUT OF THE PLAINS WILL SPREAD RAIN AND SNOW INTO THE AREA ALONG WITH MVFR TO IFR CEILINGS. THE TAF SITE WITH THE BEST CHANCE FOR PRECIPITATION IS KDAN WITH A SOUTHERN TRACK OF SHORTWAVE. SCATTERED MVFR/IFR SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES. KBLF HAS THE BEST CHANCE FOR SNOW SHOWERS. HIGH PRESSURE WILL BUILD ACROSS THE REGION WEDNESDAY NIGHT INTO THURSDAY. HIGH CONFIDENCES IN CEILINGS...VISIBILITIES AND WINDS DURING THE TAF PERIOD. EXTENDED DISCUSSION... WEDNESDAY NIGHT UPSLOPE IFR CEILINGS ARE EXPECTED IN THE MOUNTAINS. VISIBILITIES AT KBLF AND KLWB WILL OCCASIONALLY DROP TO MVFR IN SNOW SHOWERS. BY THURSDAY...HIGH PRESSURE WILL MOVE OVERHEAD...AND BRING A RETURN TO VFR CONDITIONS AT ALL SITES THROUGH FRIDAY. ANOTHER LOW PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY...BUT IT COULD SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS. && .HYDROLOGY... AS OF 1025 AM EST TUESDAY... PRECIPITATION DONE FOR THIS EVENT AND NOW WATCHING TO SEE IF SIGNIFICANT HYDROLOGIC ISSUES DEVELOP. A FEW FLOOD ADVISORIES AND AREAL FLOOD WARNINGS WERE ISSUED WITH THE HEAVY RAIN OVERNIGHT BUT VERY LITTLE HAS BEEN REPORTED IN THE WAY OF IMPACTS. STORM TOTAL PRECIPITATION (2-DAY) IN THE FORM OF SNOW AND RAIN (MUCH OF IT FREEZING) HAS RANGED GENERALLY FROM 1 TO 2.5 INCHES WITH UP TO 3+ INCHES ACROSS PORTIONS OF BEDFORD...EASTERN FRANKLIN AND SOUTHERN BOTETOURT COUNTIES...ALTHOUGH THIS IS RADAR INDICATED AND NOT WELL CORROBORATED BY RAIN GAGES. WITH MUCH OF THE OVERNIGHT RAIN FALLING ONTO AND INTO A SUBSTANTIAL SNOWPACK THE HYDROLOGIC RESPONSE HAS BEEN SOMEWHAT MUTED. FORECASTS ON THE JAMES HAVE BEEN REDUCED SLIGHTLY FROM YESTERDAY AND ARE NOW EXPECTING RISES TO BELOW ACTION STAGE WITH THE EXCEPTION OF SCOTTSVILLE. BOTH THE NEW AND GREENBRIER WILL SEE VERY MODEST RISES DUE TO THE SNOWPACK ABSORBTION AND ONLY SLOW MELT OVER COMING DAYS. THE ONLY FORECAST POINT SHOWING RFC GUIDANCE ABOVE FLOOD STAGE IS THE DAN RIVER AT SOUTH BOSTON. IF IT DOES GO ABOVE THIS WOULD BE THE 8TH SEPARATE FLOOD STAGE EXCEEDANCE SINCE LAST OCTOBER. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...PW LONG TERM...JH/RCS AVIATION...AMS/KK HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1050 AM EST TUE FEB 16 2016 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES WILL MOVE NORTHEAST INTO CANADA BY THIS EVENING. ANOTHER LOW OVER THE CENTRAL PLAINS WILL TRACK INTO THE TENNESSEE VALLEY BY THIS EVENING...THEN OFFSHORE BY WEDNESDAY MORNING. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST LATE WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1050 AM EST TUESDAY... WINTER STORM WATCH CANCELED FOR REST OF FORECAST AREA. THE RAIN HAS LIFTED TO THE NORTH THIS MORNING. WIDESPREAD FREEZING RAIN HAS ENDED THIS MORNING FOR THE AREA. TEMPERATURES ARE RISING AND HAVE CLIMB INTO THE MID AND UPPER 30S FOR MOST OF THE REGION. HOWEVER...ROADS REMAIN SNOW AND ICE COVERED IN MANY LOCATIONS. MADE SOME ADJUSTMENTS IN TEMPERATURES FOR THIS MORNING CLOSER TO SURFACE OBS AND TRENDED THE LATE MORNING READINGS TOWARDS A BLEND OF HRRR AND NAM. LEANED POPS FOR LATE MORNING INTO THIS AFTERNOON TOWARDS THE HRRR AND USED WEATHER TOOL WITH NAM PROFILE. MORE CHANGES LATER TODAY. AS OF 330 AM EST TUESDAY... UPPER LOW FROM KENTUCKY THROUGH GEORGIA WILL MOVE QUICKLY NORTHEAST THIS MORNING. BROAD BAND OF SHOWERS WITH THE UPPER LOW THAT EXTENDS SOUTH INTO FLORIDA WILL ALSO MOVE NORTHEAST. EXPECT THE WESTERN EDGE OF THIS PRECIPITATION TO EXIT THE EASTERN COUNTY WARNING AREA AROUND NOON. HRRR HAS THIS BEST TIMING OF THIS BAND OF PRECIPITATION SO WILL LEAN TOWARDS THIS TIMING IN THE FORECAST. THE SHORT WAVE OVER THE DAKOTAS WILL TRACK INTO THE TENNESSEE VALLEY BY 00Z WED/7PM THIS EVENING...THEN WILL MOVE EAST ACROSS NORTH CAROLINA. MODELS CONTINUED TO SHOW SOME Q-VECTOR FORCING AND GOOD UPPER DIFFLUENCE WITH THIS FEATURE THIS EVENING. TEMPERATURES IN THE WARM NOSE AROUND 2500 FEET AGL WERE WELL INTO THE 40S AND 50S. ALREADY SEEING SOME OF THE WARMER AIR MIXING DOWN TO THE SURFACE WITH THE HIGHER RAINFALL RATES. AT THE SAME TIME THE WEDGE WAS ERODING FROM BOTH THE EAST AND THE WEST. COLD AIR DAMMING WILL BE NEARLY GONE BY 8AM...WITH ALL LOCATIONS NOT IN THE WEDGE ABOVE FREEZING AT THE SURFACE. COLDER AIR FROM 850MB DOWN TO THE SURFACE WILL COME INTO THE MOUNTAINS BEHIND THE UPPER LOW THIS AFTERNOON THEN REMAIN BETWEEN -2 TO -5 AT 850 MB OVERNIGHT. TEMPERATURES WILL FOLLOW A NON DIURNAL TREND TODAY. LOCATIONS THAT ARE ABOVE FREEZING WILL BE REMOVED FROM THE WINTER STORM WARNING. AS THE COASTAL FRONT MOVES EAST AND AIDES IN ERODE THE EASTERN SIDE OF THE WEDGE...THE MUCH WARMER AIR OVER THE COLD GROUND AND SNOW COVER WILL PRODUCE WIDESPREAD FOG. VISIBILITIES IN SOME LOCATIONS WILL BE LESS THAN ONE HALF MILE. IF THESE AREAL COVERAGE OF THESE CONDITIONS BECOMES WIDESPREAD IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA A DENSE FOG ADVISORY WILL BE ISSUED. BUT AS OF 3AM...THE LEADING EDGE OF THE WARMER AIR WAS JUST MOVING THROUGH RALEIGH. NAM...RAP AND LOCAL WRF SUGGEST THE WARM AIR ADVANCES BRIEFLY INTO THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...JUST BEFORE WINDS SHIFT TO THE WEST AND THE WARM AIR GETS PUSHED BACK EAST. WINDS ARE ANOTHER RAPIDLY CHANGING FACTOR TODAY. ON THE WEST SIDE OF THE WEDGE...DOWNSLOPE SOUTHEAST WINDS WILL PRODUCE WIND GUSTS OF 35 TO 50 MPH...BUT THE BULK OF THE STRONG LOW LEVEL JET THAT WAS PRODUCING THESE HIGHER GUSTS WILL BE MOVING EAST THIS MORNING AND WINDS WILL SHIFT TO THE WEST BY 9AM. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EST TUESDAY... A CLIPPER SYSTEM SHOULD PASS OVERHEAD ON WEDNESDAY...AND MAINTAIN SCATTERED PRECIPITATION ALONG THE WESTERN SLOPES. ALTHOUGH IT MAY START AS SNOW...TEMPERATURES COULD RISE ENOUGH TO ALLOW A MIX WITH RAIN DURING THE AFTERNOON. HOWEVER...THE HIGHEST ELEVATIONS MAY STAY AS SNOW AND ACCUMULATE UP TO A COUPLE INCHES. ELSEWHERE...SOME PASSING CLOUDS AND A BREEZY NORTHWEST WIND SHOULD BE EXPECTED. BY WEDNESDAY NIGHT...SCATTERED SNOW SHOWERS SHOULD GRADUALLY FADE...AS HIGH PRESSURE BUILDS OVERHEAD. AN UPPER LEVEL TROUGH WILL ALSO PUSH THROUGH THE MID ATLANTIC...AND SEND OVERNIGHT LOWS BELOW FREEZING. ALTHOUGH MORE SUNSHINE WILL RETURN BY THURSDAY...A LINGERING NORTHWEST BREEZE SHOULD KEEP COLD AIR ADVECTION CONTINUING THROUGH THE DAY. THE UPPER LEVEL TROUGH SHOULD PULL AWAY FROM THE MID ATLANTIC DURING THURSDAY NIGHT...AND SOME UPPER LEVEL RIDGING SHOULD TAKE PLACE. HOWEVER...CLAM WINDS AND MOSTLY CLEAR SKIES COMBINED WITH ANY REMAINING SNOWPACK...SHOULD SEND LOWS BELOW FREEZING FOR ANOTHER NIGHT. OVERALL...TEMPERATURES WERE HELD ON THE COLDER SIDE OF MOS GUIDANCE THROUGHOUT THIS PERIOD. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 315 PM EST MONDAY RESIDUAL 500 MB TROUGH WILL FINALLY LIFT OUT TO THE NORTHEAST ON THURSDAY AS HEIGHTS START TO BUILD FROM THE WEST AHEAD OF A RATHER POTENT SHORTWAVE AND ASSOCIATED SURFACE LOW THAT WILL BE CROSSING THE GREAT LAKES ON FRIDAY. THIS SHOULD BOOT A SURFACE WARM FRONT THROUGH THE REGION FRIDAY AFTERNOON AS THE LINGERING WEDGE OF SURFACE HIGH PRESSURE TO THE NORTH REPOSITIONS OFF THE CAROLINAS BY LATE FRIDAY. RAPID JUMP IN 85H TEMPERATURES UNDER THE DEVELOPING SHORTWAVE RIDGE LOOKS TO PUSH HIGHS TO JUST ABOVE NORMAL AFTER REMAINING COOL THURSDAY UNDER THE CANADIAN HIGH TO THE NORTH. HOWEVER GIVEN SOME LINGERING SNOW PACK AND EVOLVING TRANSITION OF THE SURFACE HIGH...WILL STAY A BIT BELOW MOS FRIDAY ESPECIALLY EAST. OTHERWISE DRY BUT STILL ON THE COLD SIDE THURSDAY NIGHT THEN WARMER FRIDAY. MAJORITY OF THE NORTHERN STREAM ENERGY WILL PASS TO THE NORTH TO START THE WEEKEND WHILE ALLOWING ITS TRAILING TROUGH AXIS TO FLATTEN THE ONGOING MID LEVEL RIDGING TO SOME DEGREE. THE ASSOCIATED WEAK COLD FRONT SHOULD PRESS ACROSS THE REGION SATURDAY BUT GIVEN VERY LIMITED MOISTURE...AND MOST COLD ADVECTION TO THE NORTH APPEARS ONLY A FEW RAIN SHOWERS POSSIBLE MAINLY FAR WEST. WITH COOL AIR LIKELY TO LAG THE FRONT AND LESS CLOUDS HEADING EAST OF THE MOUNTAINS...WOULD EXPECT TEMPS TO REALLY JUMP UNDER WESTERLY FLOW WITH HIGHS WELL ABOVE NORMAL...MAINLY 50S WEST TO 60S EAST. WEAK BUBBLE HIGH WILL FOLLOW THIS WEAK FRONT ON SUNDAY WITH SKIES CLEARING BEFORE RETURN MOISTURE STARTS TO RETURN LATER IN THE DAY AHEAD OF THE NEXT UPSTREAM TROUGHS. TIMING OF THIS MOISTURE ALONG WITH POTENTIAL FOR A SOUTHERN STREAM WAVE TO PERHAPS SLOW UP THE NEXT FRONT....PER THE EARLIER EC...SUPPORTS MAINLY DRY AND CONTINUED MILD SUNDAY. SLOW RETURN TO EASTERN TROFFINESS APPEARS TO BE IN ORDER BY EARLY NEXT WEEK WITH THIS NEXT FRONT SLIDING ACROSS PRODUCING THE NEED FOR LOW RAIN SHOWER POPS AND SLIGHTLY COOLER TEMPS BUT STILL OVERALL A BIT ABOVE NORMAL FOR DAY 7. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... AS OF 650 AM EST TUESDAY... HIGH CONFIDENCE OF RAPIDLY CHANGING WEATHER DURING THE TAF FORECAST PERIOD. TIMING OF THE CHANGES IS MORE QUESTIONABLE AT ALL TAF SITES. WEDGE OF COLD AIR ALONG AND EAST OF THE BLUE RIDGE WAS ERODING AND AS SURFACE TEMPERATURES SLOWLY CLIMB AT KROA AND KLYH THIS MORNING FREEZING RAIN WILL CHANGE TO RAIN. A STRONG LOW PRESSURE SYSTEM WILL PUSH A BAND OF MODERATE TO HEAVY RAIN WITH IFR TO MVFR VISIBILITIES THROUGH KLYH AND KDAN THIS MORNING. CEILINGS WILL IMPROVE EAST OF THE BLUE RIDGE BEHIND THIS LOW. AS WINDS SWITCH TO THE WEST WITH THE PASSAGE OF THE LOW...LLWS WILL END BUT GUSTY SURFACE WINDS FROM THE WEST TO NORTHWEST ARE POSSIBLE. EXPECT MAXIMUM WINDS GUSTS OF 15 TO 25 KNOTS. A LOW COMING OUT OF THE PLAINS WILL SPREAD RAIN AND SNOW INTO THE AREA ALONG WITH MVFR TO IFR CEILINGS. THIS AREA OF PRECIPITATION WILL BE EXITING THE AREA EAST OF KDAN BY THE 12Z END OF THE TAF PERIOD. MEDIUM CONFIDENCE THAT THE NORTHERN EDGE OF THIS PRECIPITATION WILL STAY SOUTH OF KROA AND KLYH OVERNIGHT. EXTENDED DISCUSSION... WEDNESDAY NIGHT UPSLOPE IFR CEILINGS ARE EXPECTED IN THE MOUNTAINS. VISIBILITIES AT KBLF AND KLWB WILL OCCASIONALLY DROP TO MVFR IN SNOW SHOWERS. BY THURSDAY...HIGH PRESSURE WILL MOVE OVERHEAD...AND BRING A RETURN TO VFR CONDITIONS AT ALL SITES THROUGH FRIDAY. ANOTHER LOW PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY...BUT IT COULD SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS. && .HYDROLOGY... AS OF 1025 AM EST TUESDAY... PRECIPITATION DONE FOR THIS EVENT AND NOW WATCHING TO SEE IF SIGNIFICANT HYDROLOGIC ISSUES DEVELOP. A FEW FLOOD ADVISORIES AND AREAL FLOOD WARNINGS WERE ISSUED WITH THE HEAVY RAIN OVERNIGHT BUT VERY LITTLE HAS BEEN REPORTED IN THE WAY OF IMPACTS. STORM TOTAL PRECIPITATION (2-DAY) IN THE FORM OF SNOW AND RAIN (MUCH OF IT FREEZING) HAS RANGED GENERALLY FROM 1 TO 2.5 INCHES WITH UP TO 3+ INCHES ACROSS PORTIONS OF BEDFORD...EASTERN FRANKLIN AND SOUTHERN BOTETOURT COUNTIES...ALTHOUGH THIS IS RADAR INDICATED AND NOT WELL CORROBORATED BY RAIN GAGES. WITH MUCH OF THE OVERNIGHT RAIN FALLING ONTO AND INTO A SUBSTANTIAL SNOWPACK THE HYDROLOGIC RESPONSE HAS BEEN SOMEWHAT MUTED. FORECASTS ON THE JAMES HAVE BEEN REDUCED SLIGHTLY FROM YESTERDAY AND ARE NOW EXPECTING RISES TO BELOW ACTION STAGE WITH THE EXCEPTION OF SCOTTSVILLE. BOTH THE NEW AND GREENBRIER WILL SEE VERY MODEST RISES DUE TO THE SNOWPACK ABSORBTION AND ONLY SLOW MELT OVER COMING DAYS. THE ONLY FORECAST POINT SHOWING RFC GUIDANCE ABOVE FLOOD STAGE IS THE DAN RIVER AT SOUTH BOSTON. IF IT DOES GO ABOVE THIS WOULD BE THE 8TH SEPARATE FLOOD STAGE EXCEEDANCE SINCE LAST OCTOBER. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...PW LONG TERM...JH/RCS AVIATION...AMS/PW HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1034 AM EST TUE FEB 16 2016 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES WILL MOVE NORTHEAST INTO CANADA BY THIS EVENING. ANOTHER LOW OVER THE CENTRAL PLAINS WILL TRACK INTO THE TENNESSEE VALLEY BY THIS EVENING...THEN OFFSHORE BY WEDNESDAY MORNING. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST LATE WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM EST TUESDAY... UPPER LOW FROM KENTUCKY THROUGH GEORGIA WILL MOVE QUICKLY NORTHEAST THIS MORNING. BROAD BAND OF SHOWERS WITH THE UPPER LOW THAT EXTENDS SOUTH INTO FLORIDA WILL ALSO MOVE NORTHEAST. EXPECT THE WESTERN EDGE OF THIS PRECIPITATION TO EXIT THE EASTERN COUNTY WARNING AREA AROUND NOON. HRRR HAS THIS BEST TIMING OF THIS BAND OF PRECIPITATION SO WILL LEAN TOWARDS THIS TIMING IN THE FORECAST. THE SHORT WAVE OVER THE DAKOTAS WILL TRACK INTO THE TENNESSEE VALLEY BY 00Z WED/7PM THIS EVENING...THEN WILL MOVE EAST ACROSS NORTH CAROLINA. MODELS CONTINUED TO SHOW SOME Q-VECTOR FORCING AND GOOD UPPER DIFFLUENCE WITH THIS FEATURE THIS EVENING. TEMPERATURES IN THE WARM NOSE AROUND 2500 FEET AGL WERE WELL INTO THE 40S AND 50S. ALREADY SEEING SOME OF THE WARMER AIR MIXING DOWN TO THE SURFACE WITH THE HIGHER RAINFALL RATES. AT THE SAME TIME THE WEDGE WAS ERODING FROM BOTH THE EAST AND THE WEST. COLD AIR DAMMING WILL BE NEARLY GONE BY 8AM...WITH ALL LOCATIONS NOT IN THE WEDGE ABOVE FREEZING AT THE SURFACE. COLDER AIR FROM 850MB DOWN TO THE SURFACE WILL COME INTO THE MOUNTAINS BEHIND THE UPPER LOW THIS AFTERNOON THEN REMAIN BETWEEN -2 TO -5 AT 850 MB OVERNIGHT. TEMPERATURES WILL FOLLOW A NON DIURNAL TREND TODAY. LOCATIONS THAT ARE ABOVE FREEZING WILL BE REMOVED FROM THE WINTER STORM WARNING. AS THE COASTAL FRONT MOVES EAST AND AIDES IN ERODE THE EASTERN SIDE OF THE WEDGE...THE MUCH WARMER AIR OVER THE COLD GROUND AND SNOW COVER WILL PRODUCE WIDESPREAD FOG. VISIBILITIES IN SOME LOCATIONS WILL BE LESS THAN ONE HALF MILE. IF THESE AREAL COVERAGE OF THESE CONDITIONS BECOMES WIDESPREAD IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA A DENSE FOG ADVISORY WILL BE ISSUED. BUT AS OF 3AM...THE LEADING EDGE OF THE WARMER AIR WAS JUST MOVING THROUGH RALEIGH. NAM...RAP AND LOCAL WRF SUGGEST THE WARM AIR ADVANCES BRIEFLY INTO THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...JUST BEFORE WINDS SHIFT TO THE WEST AND THE WARM AIR GETS PUSHED BACK EAST. WINDS ARE ANOTHER RAPIDLY CHANGING FACTOR TODAY. ON THE WEST SIDE OF THE WEDGE...DOWNSLOPE SOUTHEAST WINDS WILL PRODUCE WIND GUSTS OF 35 TO 50 MPH...BUT THE BULK OF THE STRONG LOW LEVEL JET THAT WAS PRODUCING THESE HIGHER GUSTS WILL BE MOVING EAST THIS MORNING AND WINDS WILL SHIFT TO THE WEST BY 9AM. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EST TUESDAY... A CLIPPER SYSTEM SHOULD PASS OVERHEAD ON WEDNESDAY...AND MAINTAIN SCATTERED PRECIPITATION ALONG THE WESTERN SLOPES. ALTHOUGH IT MAY START AS SNOW...TEMPERATURES COULD RISE ENOUGH TO ALLOW A MIX WITH RAIN DURING THE AFTERNOON. HOWEVER...THE HIGHEST ELEVATIONS MAY STAY AS SNOW AND ACCUMULATE UP TO A COUPLE INCHES. ELSEWHERE...SOME PASSING CLOUDS AND A BREEZY NORTHWEST WIND SHOULD BE EXPECTED. BY WEDNESDAY NIGHT...SCATTERED SNOW SHOWERS SHOULD GRADUALLY FADE...AS HIGH PRESSURE BUILDS OVERHEAD. AN UPPER LEVEL TROUGH WILL ALSO PUSH THROUGH THE MID ATLANTIC...AND SEND OVERNIGHT LOWS BELOW FREEZING. ALTHOUGH MORE SUNSHINE WILL RETURN BY THURSDAY...A LINGERING NORTHWEST BREEZE SHOULD KEEP COLD AIR ADVECTION CONTINUING THROUGH THE DAY. THE UPPER LEVEL TROUGH SHOULD PULL AWAY FROM THE MID ATLANTIC DURING THURSDAY NIGHT...AND SOME UPPER LEVEL RIDGING SHOULD TAKE PLACE. HOWEVER...CLAM WINDS AND MOSTLY CLEAR SKIES COMBINED WITH ANY REMAINING SNOWPACK...SHOULD SEND LOWS BELOW FREEZING FOR ANOTHER NIGHT. OVERALL...TEMPERATURES WERE HELD ON THE COLDER SIDE OF MOS GUIDANCE THROUGHOUT THIS PERIOD. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 315 PM EST MONDAY RESIDUAL 500 MB TROUGH WILL FINALLY LIFT OUT TO THE NORTHEAST ON THURSDAY AS HEIGHTS START TO BUILD FROM THE WEST AHEAD OF A RATHER POTENT SHORTWAVE AND ASSOCIATED SURFACE LOW THAT WILL BE CROSSING THE GREAT LAKES ON FRIDAY. THIS SHOULD BOOT A SURFACE WARM FRONT THROUGH THE REGION FRIDAY AFTERNOON AS THE LINGERING WEDGE OF SURFACE HIGH PRESSURE TO THE NORTH REPOSITIONS OFF THE CAROLINAS BY LATE FRIDAY. RAPID JUMP IN 85H TEMPERATURES UNDER THE DEVELOPING SHORTWAVE RIDGE LOOKS TO PUSH HIGHS TO JUST ABOVE NORMAL AFTER REMAINING COOL THURSDAY UNDER THE CANADIAN HIGH TO THE NORTH. HOWEVER GIVEN SOME LINGERING SNOW PACK AND EVOLVING TRANSITION OF THE SURFACE HIGH...WILL STAY A BIT BELOW MOS FRIDAY ESPECIALLY EAST. OTHERWISE DRY BUT STILL ON THE COLD SIDE THURSDAY NIGHT THEN WARMER FRIDAY. MAJORITY OF THE NORTHERN STREAM ENERGY WILL PASS TO THE NORTH TO START THE WEEKEND WHILE ALLOWING ITS TRAILING TROUGH AXIS TO FLATTEN THE ONGOING MID LEVEL RIDGING TO SOME DEGREE. THE ASSOCIATED WEAK COLD FRONT SHOULD PRESS ACROSS THE REGION SATURDAY BUT GIVEN VERY LIMITED MOISTURE...AND MOST COLD ADVECTION TO THE NORTH APPEARS ONLY A FEW RAIN SHOWERS POSSIBLE MAINLY FAR WEST. WITH COOL AIR LIKELY TO LAG THE FRONT AND LESS CLOUDS HEADING EAST OF THE MOUNTAINS...WOULD EXPECT TEMPS TO REALLY JUMP UNDER WESTERLY FLOW WITH HIGHS WELL ABOVE NORMAL...MAINLY 50S WEST TO 60S EAST. WEAK BUBBLE HIGH WILL FOLLOW THIS WEAK FRONT ON SUNDAY WITH SKIES CLEARING BEFORE RETURN MOISTURE STARTS TO RETURN LATER IN THE DAY AHEAD OF THE NEXT UPSTREAM TROUGHS. TIMING OF THIS MOISTURE ALONG WITH POTENTIAL FOR A SOUTHERN STREAM WAVE TO PERHAPS SLOW UP THE NEXT FRONT....PER THE EARLIER EC...SUPPORTS MAINLY DRY AND CONTINUED MILD SUNDAY. SLOW RETURN TO EASTERN TROFFINESS APPEARS TO BE IN ORDER BY EARLY NEXT WEEK WITH THIS NEXT FRONT SLIDING ACROSS PRODUCING THE NEED FOR LOW RAIN SHOWER POPS AND SLIGHTLY COOLER TEMPS BUT STILL OVERALL A BIT ABOVE NORMAL FOR DAY 7. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... AS OF 650 AM EST TUESDAY... HIGH CONFIDENCE OF RAPIDLY CHANGING WEATHER DURING THE TAF FORECAST PERIOD. TIMING OF THE CHANGES IS MORE QUESTIONABLE AT ALL TAF SITES. WEDGE OF COLD AIR ALONG AND EAST OF THE BLUE RIDGE WAS ERODING AND AS SURFACE TEMPERATURES SLOWLY CLIMB AT KROA AND KLYH THIS MORNING FREEZING RAIN WILL CHANGE TO RAIN. A STRONG LOW PRESSURE SYSTEM WILL PUSH A BAND OF MODERATE TO HEAVY RAIN WITH IFR TO MVFR VISIBILITIES THROUGH KLYH AND KDAN THIS MORNING. CEILINGS WILL IMPROVE EAST OF THE BLUE RIDGE BEHIND THIS LOW. AS WINDS SWITCH TO THE WEST WITH THE PASSAGE OF THE LOW...LLWS WILL END BUT GUSTY SURFACE WINDS FROM THE WEST TO NORTHWEST ARE POSSIBLE. EXPECT MAXIMUM WINDS GUSTS OF 15 TO 25 KNOTS. A LOW COMING OUT OF THE PLAINS WILL SPREAD RAIN AND SNOW INTO THE AREA ALONG WITH MVFR TO IFR CEILINGS. THIS AREA OF PRECIPITATION WILL BE EXITING THE AREA EAST OF KDAN BY THE 12Z END OF THE TAF PERIOD. MEDIUM CONFIDENCE THAT THE NORTHERN EDGE OF THIS PRECIPITATION WILL STAY SOUTH OF KROA AND KLYH OVERNIGHT. EXTENDED DISCUSSION... WEDNESDAY NIGHT UPSLOPE IFR CEILINGS ARE EXPECTED IN THE MOUNTAINS. VISIBILITIES AT KBLF AND KLWB WILL OCCASIONALLY DROP TO MVFR IN SNOW SHOWERS. BY THURSDAY...HIGH PRESSURE WILL MOVE OVERHEAD...AND BRING A RETURN TO VFR CONDITIONS AT ALL SITES THROUGH FRIDAY. ANOTHER LOW PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY...BUT IT COULD SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS. && .HYDROLOGY... AS OF 1025 AM EST TUESDAY... PRECIPITATION DONE FOR THIS EVENT AND NOW WATCHING TO SEE IF SIGNIFICANT HYDROLOGIC ISSUES DEVELOP. A FEW FLOOD ADVISORIES AND AREAL FLOOD WARNINGS WERE ISSUED WITH THE HEAVY RAIN OVERNIGHT BUT VERY LITTLE HAS BEEN REPORTED IN THE WAY OF IMPACTS. STORM TOTAL PRECIPITATION (2-DAY) IN THE FORM OF SNOW AND RAIN (MUCH OF IT FREEZING) HAS RANGED GENERALLY FROM 1 TO 2.5 INCHES WITH UP TO 3+ INCHES ACROSS PORTIONS OF BEDFORD...EASTERN FRANKLIN AND SOUTHERN BOTETOURT COUNTIES...ALTHOUGH THIS IS RADAR INDICATED AND NOT WELL CORROBORATED BY RAIN GAGES. WITH MUCH OF THE OVERNIGHT RAIN FALLING ONTO AND INTO A SUBSTANTIAL SNOWPACK THE HYDROLOGIC RESPONSE HAS BEEN SOMEWHAT MUTED. FORECASTS ON THE JAMES HAVE BEEN REDUCED SLIGHTLY FROM YESTERDAY AND ARE NOW EXPECTING RISES TO BELOW ACTION STAGE WITH THE EXCEPTION OF SCOTTSVILLE. BOTH THE NEW AND GREENBRIER WILL SEE VERY MODEST RISES DUE TO THE SNOWPACK ABSORBTION AND ONLY SLOW MELT OVER COMING DAYS. THE ONLY FORECAST POINT SHOWING RFC GUIDANCE ABOVE FLOOD STAGE IS THE DAN RIVER AT SOUTH BOSTON. IF IT DOES GO ABOVE THIS WOULD BE THE 8TH SEPARATE FLOOD STAGE EXCEEDANCE SINCE LAST OCTOBER. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...PW LONG TERM...JH/RCS AVIATION...AMS/PW HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
721 AM EST TUE FEB 16 2016 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES WILL MOVE NORTHEAST INTO CANADA BY THIS EVENING. ANOTHER LOW OVER THE CENTRAL PLAINS WILL TRACK INTO THE TENNESSEE VALLEY BY THIS EVENING...THEN OFFSHORE BY WEDNESDAY MORNING. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST LATE WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM EST TUESDAY... UPPER LOW FROM KENTUCKY THROUGH GEORGIA WILL MOVE QUICKLY NORTHEAST THIS MORNING. BROAD BAND OF SHOWERS WITH THE UPPER LOW THAT EXTENDS SOUTH INTO FLORIDA WILL ALSO MOVE NORTHEAST. EXPECT THE WESTERN EDGE OF THIS PRECIPITATION TO EXIT THE EASTERN COUNTY WARNING AREA AROUND NOON. HRRR HAS THIS BEST TIMING OF THIS BAND OF PRECIPITATION SO WILL LEAN TOWARDS THIS TIMING IN THE FORECAST. THE SHORT WAVE OVER THE DAKOTAS WILL TRACK INTO THE TENNESSEE VALLEY BY 00Z WED/7PM THIS EVENING...THEN WILL MOVE EAST ACROSS NORTH CAROLINA. MODELS CONTINUED TO SHOW SOME Q-VECTOR FORCING AND GOOD UPPER DIFFLUENCE WITH THIS FEATURE THIS EVENING. TEMPERATURES IN THE WARM NOSE AROUND 2500 FEET AGL WERE WELL INTO THE 40S AND 50S. ALREADY SEEING SOME OF THE WARMER AIR MIXING DOWN TO THE SURFACE WITH THE HIGHER RAINFALL RATES. AT THE SAME TIME THE WEDGE WAS ERODING FROM BOTH THE EAST AND THE WEST. COLD AIR DAMMING WILL BE NEARLY GONE BY 8AM...WITH ALL LOCATIONS NOT IN THE WEDGE ABOVE FREEZING AT THE SURFACE. COLDER AIR FROM 850MB DOWN TO THE SURFACE WILL COME INTO THE MOUNTAINS BEHIND THE UPPER LOW THIS AFTERNOON THEN REMAIN BETWEEN -2 TO -5 AT 850 MB OVERNIGHT. TEMPERATURES WILL FOLLOW A NON DIURNAL TREND TODAY. LOCATIONS THAT ARE ABOVE FREEZING WILL BE REMOVED FROM THE WINTER STORM WARNING. AS THE COASTAL FRONT MOVES EAST AND AIDES IN ERODE THE EASTERN SIDE OF THE WEDGE...THE MUCH WARMER AIR OVER THE COLD GROUND AND SNOW COVER WILL PRODUCE WIDESPREAD FOG. VISIBILITIES IN SOME LOCATIONS WILL BE LESS THAN ONE HALF MILE. IF THESE AREAL COVERAGE OF THESE CONDITIONS BECOMES WIDESPREAD IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA A DENSE FOG ADVISORY WILL BE ISSUED. BUT AS OF 3AM...THE LEADING EDGE OF THE WARMER AIR WAS JUST MOVING THROUGH RALEIGH. NAM...RAP AND LOCAL WRF SUGGEST THE WARM AIR ADVANCES BRIEFLY INTO THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...JUST BEFORE WINDS SHIFT TO THE WEST AND THE WARM AIR GETS PUSHED BACK EAST. WINDS ARE ANOTHER RAPIDLY CHANGING FACTOR TODAY. ON THE WEST SIDE OF THE WEDGE...DOWNSLOPE SOUTHEAST WINDS WILL PRODUCE WIND GUSTS OF 35 TO 50 MPH...BUT THE BULK OF THE STRONG LOW LEVEL JET THAT WAS PRODUCING THESE HIGHER GUSTS WILL BE MOVING EAST THIS MORNING AND WINDS WILL SHIFT TO THE WEST BY 9AM. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EST TUESDAY... A CLIPPER SYSTEM SHOULD PASS OVERHEAD ON WEDNESDAY...AND MAINTAIN SCATTERED PRECIPITATION ALONG THE WESTERN SLOPES. ALTHOUGH IT MAY START AS SNOW...TEMPERATURES COULD RISE ENOUGH TO ALLOW A MIX WITH RAIN DURING THE AFTERNOON. HOWEVER...THE HIGHEST ELEVATIONS MAY STAY AS SNOW AND ACCUMULATE UP TO A COUPLE INCHES. ELSEWHERE...SOME PASSING CLOUDS AND A BREEZY NORTHWEST WIND SHOULD BE EXPECTED. BY WEDNESDAY NIGHT...SCATTERED SNOW SHOWERS SHOULD GRADUALLY FADE...AS HIGH PRESSURE BUILDS OVERHEAD. AN UPPER LEVEL TROUGH WILL ALSO PUSH THROUGH THE MID ATLANTIC...AND SEND OVERNIGHT LOWS BELOW FREEZING. ALTHOUGH MORE SUNSHINE WILL RETURN BY THURSDAY...A LINGERING NORTHWEST BREEZE SHOULD KEEP COLD AIR ADVECTION CONTINUING THROUGH THE DAY. THE UPPER LEVEL TROUGH SHOULD PULL AWAY FROM THE MID ATLANTIC DURING THURSDAY NIGHT...AND SOME UPPER LEVEL RIDGING SHOULD TAKE PLACE. HOWEVER...CLAM WINDS AND MOSTLY CLEAR SKIES COMBINED WITH ANY REMAINING SNOWPACK...SHOULD SEND LOWS BELOW FREEZING FOR ANOTHER NIGHT. OVERALL...TEMPERATURES WERE HELD ON THE COLDER SIDE OF MOS GUIDANCE THROUGHOUT THIS PERIOD. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 315 PM EST MONDAY RESIDUAL 500 MB TROUGH WILL FINALLY LIFT OUT TO THE NORTHEAST ON THURSDAY AS HEIGHTS START TO BUILD FROM THE WEST AHEAD OF A RATHER POTENT SHORTWAVE AND ASSOCIATED SURFACE LOW THAT WILL BE CROSSING THE GREAT LAKES ON FRIDAY. THIS SHOULD BOOT A SURFACE WARM FRONT THROUGH THE REGION FRIDAY AFTERNOON AS THE LINGERING WEDGE OF SURFACE HIGH PRESSURE TO THE NORTH REPOSITIONS OFF THE CAROLINAS BY LATE FRIDAY. RAPID JUMP IN 85H TEMPERATURES UNDER THE DEVELOPING SHORTWAVE RIDGE LOOKS TO PUSH HIGHS TO JUST ABOVE NORMAL AFTER REMAINING COOL THURSDAY UNDER THE CANADIAN HIGH TO THE NORTH. HOWEVER GIVEN SOME LINGERING SNOW PACK AND EVOLVING TRANSITION OF THE SURFACE HIGH...WILL STAY A BIT BELOW MOS FRIDAY ESPECIALLY EAST. OTHERWISE DRY BUT STILL ON THE COLD SIDE THURSDAY NIGHT THEN WARMER FRIDAY. MAJORITY OF THE NORTHERN STREAM ENERGY WILL PASS TO THE NORTH TO START THE WEEKEND WHILE ALLOWING ITS TRAILING TROUGH AXIS TO FLATTEN THE ONGOING MID LEVEL RIDGING TO SOME DEGREE. THE ASSOCIATED WEAK COLD FRONT SHOULD PRESS ACROSS THE REGION SATURDAY BUT GIVEN VERY LIMITED MOISTURE...AND MOST COLD ADVECTION TO THE NORTH APPEARS ONLY A FEW RAIN SHOWERS POSSIBLE MAINLY FAR WEST. WITH COOL AIR LIKELY TO LAG THE FRONT AND LESS CLOUDS HEADING EAST OF THE MOUNTAINS...WOULD EXPECT TEMPS TO REALLY JUMP UNDER WESTERLY FLOW WITH HIGHS WELL ABOVE NORMAL...MAINLY 50S WEST TO 60S EAST. WEAK BUBBLE HIGH WILL FOLLOW THIS WEAK FRONT ON SUNDAY WITH SKIES CLEARING BEFORE RETURN MOISTURE STARTS TO RETURN LATER IN THE DAY AHEAD OF THE NEXT UPSTREAM TROUGHS. TIMING OF THIS MOISTURE ALONG WITH POTENTIAL FOR A SOUTHERN STREAM WAVE TO PERHAPS SLOW UP THE NEXT FRONT....PER THE EARLIER EC...SUPPORTS MAINLY DRY AND CONTINUED MILD SUNDAY. SLOW RETURN TO EASTERN TROFFINESS APPEARS TO BE IN ORDER BY EARLY NEXT WEEK WITH THIS NEXT FRONT SLIDING ACROSS PRODUCING THE NEED FOR LOW RAIN SHOWER POPS AND SLIGHTLY COOLER TEMPS BUT STILL OVERALL A BIT ABOVE NORMAL FOR DAY 7. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 650 AM EST TUESDAY... HIGH CONFIDENCE OF RAPIDLY CHANGING WEATHER DURING THE TAF FORECAST PERIOD. TIMING OF THE CHANGES IS MORE QUESTIONABLE AT ALL TAF SITES. WEDGE OF COLD AIR ALONG AND EAST OF THE BLUE RIDGE WAS ERODING AND AS SURFACE TEMPERATURES SLOWLY CLIMB AT KROA AND KLYH THIS MORNING FREEZING RAIN WILL CHANGE TO RAIN. A STRONG LOW PRESSURE SYSTEM WILL PUSH A BAND OF MODERATE TO HEAVY RAIN WITH IFR TO MVFR VISIBILITIES THROUGH KLYH AND KDAN THIS MORNING. CEILINGS WILL IMPROVE EAST OF THE BLUE RIDGE BEHIND THIS LOW. AS WINDS SWITCH TO THE WEST WITH THE PASSAGE OF THE LOW...LLWS WILL END BUT GUSTY SURFACE WINDS FROM THE WEST TO NORTHWEST ARE POSSIBLE. EXPECT MAXIMUM WINDS GUSTS OF 15 TO 25 KNOTS. A LOW COMING OUT OF THE PLAINS WILL SPREAD RAIN AND SNOW INTO THE AREA ALONG WITH MVFR TO IFR CEILINGS. THIS AREA OF PRECIPITATION WILL BE EXITING THE AREA EAST OF KDAN BY THE 12Z END OF THE TAF PERIOD. MEDIUM CONFIDENCE THAT THE NORTHERN EDGE OF THIS PRECIPITATION WILL STAY SOUTH OF KROA AND KLYH OVERNIGHT. EXTENDED DISCUSSION... WEDNESDAY NIGHT UPSLOPE IFR CEILINGS ARE EXPECTED IN THE MOUNTAINS. VISIBILITIES AT KBLF AND KLWB WILL OCCASIONALLY DROP TO MVFR IN SNOW SHOWERS. BY THURSDAY...HIGH PRESSURE WILL MOVE OVERHEAD...AND BRING A RETURN TO VFR CONDITIONS AT ALL SITES THROUGH FRIDAY. ANOTHER LOW PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY...BUT IT COULD SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS. && .HYDROLOGY... AS OF 505 AM EST TUESDAY... TRANSITION FROM A WINTER EVENT TO POTENTIAL FOR HYDRO EVENT CONTINUES TO BE ONE OF THE ISSUES ON THE TABLE. ACCUMULATING SNOW WAS FINISHED ACROSS THE CWA AS THE WARM NOSE WORKS FURTHER NORTH. WIDESPREAD 5 TO 10 INCHES OF SNOW WAS OBSERVED WITH THE EXCEPTION OF SOUTHEAST PIEDMONT COUNTIES WITH 2 TO 4 INCHES. WITH SNOW- LIQUID RATIOS RUNNING CLOSE TO 10:1 WE HAVE A SOLID 0.50 TO 1 INCH OF SNOW WATER EQUIVALENT ON THE GROUND. PRECIPITATION WAS CHANGING TO ALL LIQUID FROM SOUTHWEST TO NORTHEAST EARLY THIS MORNING. AS THE MODERATE RAIN FALLS OVER THE SNOW AND ICE...THERE HAS BEEN WIDESPREAD PONDING OF WATER AND SOME OF THE RAIN HAD BEEN RUNNING OFF THE SURFACE OF THE ICE AND SNOW. AT THIS TIME WE HAVE RECEIVED NO REPORTS OF ANYTHING MORE THAN NUISANCE FLOODING. BASICALLY FOLLOWED WPC QPF NEXT 24 HOURS... WHICH IS RUNNING IN THE 1.00 TO 1.75 INCH RANGE CWA-WIDE THROUGH 12Z/7AM THIS MORNING.NORMALLY THIS AMOUNT WOULD BE SUFFICIENT FOR SOME FLOODING BOTH SHORT-FUSE (FLASH) AND LONG-FUSE (RIVERS). BUT THE EXISTING SNOWPACK IS A BIG COMPLICATING FACTOR. IT WILL ABSORB QUITE A BIT OF RAIN AND DEPENDING ON THE EXACT TEMPERATURE/DEWPOINT REGIME IT COULD BE THAT MOST IS ABSORBED...WITH ONLY LIMITED RUNOFF. HENCE...AFTER COORDINATING WITH SURROUNDING WFOS HAVE OPTED TO NOT ISSUE ANY TYPE OF FLOOD WATCH FOR THE CWA. ONCE IT ALL MELTS SOME RIVER FLOODING SEEMS VERY LIKELY..ESPECIALLY ON THE DAN AND LOWER ROANOKE. VARIOUS ENSEMBLE RIVER FORECAST GUIDANCE SHOWS UP TO A 70 PERCENT CHANCE OF MINOR FLOODING ON THE LOWER DAN AND MORE LIKE 30 PERCENT ALONG PARTS OF THE JAMES RIVER WITHIN A FEW DAYS. ALTHOUGH THE SIGNAL FOR WIDESPREAD FLOODING REMAINS AMBIGUOUS...WILL HAVE TO WATCH CLOSELY EVOLVING QPF FORECASTS AND THE OBSERVED AND MODELED RATE OF SNOWMELT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER STORM WARNING UNTIL NOON EST TODAY FOR VAZ011-013-014- 017>020-022>024-032>035-043>047-058-059. NC...WINTER STORM WARNING UNTIL NOON EST TODAY FOR NCZ004>006. WV...WINTER STORM WARNING UNTIL NOON EST TODAY FOR WVZ043-044-507- 508. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...PW LONG TERM...JH/RCS AVIATION...AMS/PW HYDROLOGY...AMS/PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
515 AM EST TUE FEB 16 2016 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES WILL MOVE NORTHEAST INTO CANADA BY THIS EVENING. ANOTHER LOW OVER THE CENTRAL PLAINS WILL TRACK INTO THE TENNESSEE VALLEY BY THIS EVENING...THEN OFFSHORE BY WEDNESDAY MORNING. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST LATE WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM EST TUESDAY... UPPER LOW FROM KENTUCKY THROUGH GEORGIA WILL MOVE QUICKLY NORTHEAST THIS MORNING. BROAD BAND OF SHOWERS WITH THE UPPER LOW THAT EXTENDS SOUTH INTO FLORIDA WILL ALSO MOVE NORTHEAST. EXPECT THE WESTERN EDGE OF THIS PRECIPITATION TO EXIT THE EASTERN COUNTY WARNING AREA AROUND NOON. HRRR HAS THIS BEST TIMING OF THIS BAND OF PRECIPITATION SO WILL LEAN TOWARDS THIS TIMING IN THE FORECAST. THE SHORT WAVE OVER THE DAKOTAS WILL TRACK INTO THE TENNESSEE VALLEY BY 00Z WED/7PM THIS EVENING...THEN WILL MOVE EAST ACROSS NORTH CAROLINA. MODELS CONTINUED TO SHOW SOME Q-VECTOR FORCING AND GOOD UPPER DIFFLUENCE WITH THIS FEATURE THIS EVENING. TEMPERATURES IN THE WARM NOSE AROUND 2500 FEET AGL WERE WELL INTO THE 40S AND 50S. ALREADY SEEING SOME OF THE WARMER AIR MIXING DOWN TO THE SURFACE WITH THE HIGHER RAINFALL RATES. AT THE SAME TIME THE WEDGE WAS ERODING FROM BOTH THE EAST AND THE WEST. COLD AIR DAMMING WILL BE NEARLY GONE BY 8AM...WITH ALL LOCATIONS NOT IN THE WEDGE ABOVE FREEZING AT THE SURFACE. COLDER AIR FROM 850MB DOWN TO THE SURFACE WILL COME INTO THE MOUNTAINS BEHIND THE UPPER LOW THIS AFTERNOON THEN REMAIN BETWEEN -2 TO -5 AT 850 MB OVERNIGHT. TEMPERATURES WILL FOLLOW A NON DIURNAL TREND TODAY. LOCATIONS THAT ARE ABOVE FREEZING WILL BE REMOVED FROM THE WINTER STORM WARNING. AS THE COASTAL FRONT MOVES EAST AND AIDES IN ERODE THE EASTERN SIDE OF THE WEDGE...THE MUCH WARMER AIR OVER THE COLD GROUND AND SNOW COVER WILL PRODUCE WIDESPREAD FOG. VISIBILITIES IN SOME LOCATIONS WILL BE LESS THAN ONE HALF MILE. IF THESE AREAL COVERAGE OF THESE CONDITIONS BECOMES WIDESPREAD IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA A DENSE FOG ADVISORY WILL BE ISSUED. BUT AS OF 3AM...THE LEADING EDGE OF THE WARMER AIR WAS JUST MOVING THROUGH RALEIGH. NAM...RAP AND LOCAL WRF SUGGEST THE WARM AIR ADVANCES BRIEFLY INTO THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...JUST BEFORE WINDS SHIFT TO THE WEST AND THE WARM AIR GETS PUSHED BACK EAST. WINDS ARE ANOTHER RAPIDLY CHANGING FACTOR TODAY. ON THE WEST SIDE OF THE WEDGE...DOWNSLOPE SOUTHEAST WINDS WILL PRODUCE WIND GUSTS OF 35 TO 50 MPH...BUT THE BULK OF THE STRONG LOW LEVEL JET THAT WAS PRODUCING THESE HIGHER GUSTS WILL BE MOVING EAST THIS MORNING AND WINDS WILL SHIFT TO THE WEST BY 9AM. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EST TUESDAY... A CLIPPER SYSTEM SHOULD PASS OVERHEAD ON WEDNESDAY...AND MAINTAIN SCATTERED PRECIPITATION ALONG THE WESTERN SLOPES. ALTHOUGH IT MAY START AS SNOW...TEMPERATURES COULD RISE ENOUGH TO ALLOW A MIX WITH RAIN DURING THE AFTERNOON. HOWEVER...THE HIGHEST ELEVATIONS MAY STAY AS SNOW AND ACCUMULATE UP TO A COUPLE INCHES. ELSEWHERE...SOME PASSING CLOUDS AND A BREEZY NORTHWEST WIND SHOULD BE EXPECTED. BY WEDNESDAY NIGHT...SCATTERED SNOW SHOWERS SHOULD GRADUALLY FADE...AS HIGH PRESSURE BUILDS OVERHEAD. AN UPPER LEVEL TROUGH WILL ALSO PUSH THROUGH THE MID ATLANTIC...AND SEND OVERNIGHT LOWS BELOW FREEZING. ALTHOUGH MORE SUNSHINE WILL RETURN BY THURSDAY...A LINGERING NORTHWEST BREEZE SHOULD KEEP COLD AIR ADVECTION CONTINUING THROUGH THE DAY. THE UPPER LEVEL TROUGH SHOULD PULL AWAY FROM THE MID ATLANTIC DURING THURSDAY NIGHT...AND SOME UPPER LEVEL RIDGING SHOULD TAKE PLACE. HOWEVER...CLAM WINDS AND MOSTLY CLEAR SKIES COMBINED WITH ANY REMAINING SNOWPACK...SHOULD SEND LOWS BELOW FREEZING FOR ANOTHER NIGHT. OVERALL...TEMPERATURES WERE HELD ON THE COLDER SIDE OF MOS GUIDANCE THROUGHOUT THIS PERIOD. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 315 PM EST MONDAY RESIDUAL 500 MB TROUGH WILL FINALLY LIFT OUT TO THE NORTHEAST ON THURSDAY AS HEIGHTS START TO BUILD FROM THE WEST AHEAD OF A RATHER POTENT SHORTWAVE AND ASSOCIATED SURFACE LOW THAT WILL BE CROSSING THE GREAT LAKES ON FRIDAY. THIS SHOULD BOOT A SURFACE WARM FRONT THROUGH THE REGION FRIDAY AFTERNOON AS THE LINGERING WEDGE OF SURFACE HIGH PRESSURE TO THE NORTH REPOSITIONS OFF THE CAROLINAS BY LATE FRIDAY. RAPID JUMP IN 85H TEMPERATURES UNDER THE DEVELOPING SHORTWAVE RIDGE LOOKS TO PUSH HIGHS TO JUST ABOVE NORMAL AFTER REMAINING COOL THURSDAY UNDER THE CANADIAN HIGH TO THE NORTH. HOWEVER GIVEN SOME LINGERING SNOW PACK AND EVOLVING TRANSITION OF THE SURFACE HIGH...WILL STAY A BIT BELOW MOS FRIDAY ESPECIALLY EAST. OTHERWISE DRY BUT STILL ON THE COLD SIDE THURSDAY NIGHT THEN WARMER FRIDAY. MAJORITY OF THE NORTHERN STREAM ENERGY WILL PASS TO THE NORTH TO START THE WEEKEND WHILE ALLOWING ITS TRAILING TROUGH AXIS TO FLATTEN THE ONGOING MID LEVEL RIDGING TO SOME DEGREE. THE ASSOCIATED WEAK COLD FRONT SHOULD PRESS ACROSS THE REGION SATURDAY BUT GIVEN VERY LIMITED MOISTURE...AND MOST COLD ADVECTION TO THE NORTH APPEARS ONLY A FEW RAIN SHOWERS POSSIBLE MAINLY FAR WEST. WITH COOL AIR LIKELY TO LAG THE FRONT AND LESS CLOUDS HEADING EAST OF THE MOUNTAINS...WOULD EXPECT TEMPS TO REALLY JUMP UNDER WESTERLY FLOW WITH HIGHS WELL ABOVE NORMAL...MAINLY 50S WEST TO 60S EAST. WEAK BUBBLE HIGH WILL FOLLOW THIS WEAK FRONT ON SUNDAY WITH SKIES CLEARING BEFORE RETURN MOISTURE STARTS TO RETURN LATER IN THE DAY AHEAD OF THE NEXT UPSTREAM TROUGHS. TIMING OF THIS MOISTURE ALONG WITH POTENTIAL FOR A SOUTHERN STREAM WAVE TO PERHAPS SLOW UP THE NEXT FRONT....PER THE EARLIER EC...SUPPORTS MAINLY DRY AND CONTINUED MILD SUNDAY. SLOW RETURN TO EASTERN TROFFINESS APPEARS TO BE IN ORDER BY EARLY NEXT WEEK WITH THIS NEXT FRONT SLIDING ACROSS PRODUCING THE NEED FOR LOW RAIN SHOWER POPS AND SLIGHTLY COOLER TEMPS BUT STILL OVERALL A BIT ABOVE NORMAL FOR DAY 7. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... AS OF 1250 AM EST TUESDAY... POOR FLYING CONDITIONS SHOULD CONTINUE THROUGH THE REMAINDER OF TONIGHT. CONFIDENCE IS HIGH FOR LIFR/IFR CEILINGS AND VISIBILITIES TO OCCUR AT SOME POINT DURING EARLY TUESDAY MORNING. SIGNIFICANT ICING WILL REMAIN A CONCERN DUE TO PERIODS OF FREEZING RAIN...AS TEMPERATURES HOLD JUST BELOW FREEZING AT ALL SITES...EXCEPT FOR BLF WHERE SURFACE TEMPERATURES HAVE ALLOWED FOR COLD RAIN TO FALL. SOUTH WINDS MAY GUST UP TO 30 KT AT BLF THROUGH THE NIGHT DUE TO A STRONG LOW LEVEL JET. WARMER AIR ALOFT SHOULD FINALLY ERODE THE COOL WEDGE ON TUESDAY...SO ANY FREEZING RAIN SHOULD TRANSITION OVER TOWARD LIGHT TO MODERATE RAIN. HOWEVER...CEILINGS AND VISIBILITIES MAY NOT IMPROVE MUCH UNTIL LATER IN THE DAY. WINDS SHOULD TURN TO THE WEST AS THE COLD FRONT CROSSES OVERHEAD...AND GUST UP TO 25 KT BY THE AFTERNOON. WHILE CONDITIONS SHOULD EVENTUALLY REACH VFR FOR ROA/LYH/DAN DURING THE START OF TUESDAY NIGHT...BLF/LWB/BCB WILL ENCOUNTER A TRAILING CLIPPER SYSTEM THAT SHOULD SPARK SOME MOUNTAIN SNOW SHOWERS AND MORE IFR/LIFR CONDITIONS. EXTENDED DISCUSSION... A CLIPPER SYSTEM WILL BRING MOUNTAIN SNOW SHOWERS AND POOR FLYING CONDITIONS WEST OF THE BLUE RIDGE THROUGH THE REMAINDER OF TUESDAY NIGHT INTO WEDNESDAY. ELSEWHERE...VFR CONDITIONS SHOULD PREVAIL. BY THURSDAY...HIGH PRESSURE WILL MOVE OVERHEAD...AND BRING A RETURN TO VFR CONDITIONS AT ALL SITES THROUGH FRIDAY. ANOTHER LOW PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY...BUT IT COULD SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS. && .HYDROLOGY... AS OF 505 AM EST TUESDAY... TRANSITION FROM A WINTER EVENT TO POTENTIAL FOR HYDRO EVENT CONTINUES TO BE ONE OF THE ISSUES ON THE TABLE. ACCUMULATING SNOW WAS FINISHED ACROSS THE CWA AS THE WARM NOSE WORKS FURTHER NORTH. WIDESPREAD 5 TO 10 INCHES OF SNOW WAS OBSERVED WITH THE EXCEPTION OF SOUTHEAST PIEDMONT COUNTIES WITH 2 TO 4 INCHES. WITH SNOW- LIQUID RATIOS RUNNING CLOSE TO 10:1 WE HAVE A SOLID 0.50 TO 1 INCH OF SNOW WATER EQUIVALENT ON THE GROUND. PRECIPITATION WAS CHANGING TO ALL LIQUID FROM SOUTHWEST TO NORTHEAST EARLY THIS MORNING. AS THE MODERATE RAIN FALLS OVER THE SNOW AND ICE...THERE HAS BEEN WIDESPREAD PONDING OF WATER AND SOME OF THE RAIN HAD BEEN RUNNING OFF THE SURFACE OF THE ICE AND SNOW. AT THIS TIME WE HAVE RECEIVED NO REPORTS OF ANYTHING MORE THAN NUISANCE FLOODING. BASICALLY FOLLOWED WPC QPF NEXT 24 HOURS... WHICH IS RUNNING IN THE 1.00 TO 1.75 INCH RANGE CWA-WIDE THROUGH 12Z/7AM THIS MORNING.NORMALLY THIS AMOUNT WOULD BE SUFFICIENT FOR SOME FLOODING BOTH SHORT-FUSE (FLASH) AND LONG-FUSE (RIVERS). BUT THE EXISTING SNOWPACK IS A BIG COMPLICATING FACTOR. IT WILL ABSORB QUITE A BIT OF RAIN AND DEPENDING ON THE EXACT TEMPERATURE/DEWPOINT REGIME IT COULD BE THAT MOST IS ABSORBED...WITH ONLY LIMITED RUNOFF. HENCE...AFTER COORDINATING WITH SURROUNDING WFOS HAVE OPTED TO NOT ISSUE ANY TYPE OF FLOOD WATCH FOR THE CWA. ONCE IT ALL MELTS SOME RIVER FLOODING SEEMS VERY LIKELY..ESPECIALLY ON THE DAN AND LOWER ROANOKE. VARIOUS ENSEMBLE RIVER FORECAST GUIDANCE SHOWS UP TO A 70 PERCENT CHANCE OF MINOR FLOODING ON THE LOWER DAN AND MORE LIKE 30 PERCENT ALONG PARTS OF THE JAMES RIVER WITHIN A FEW DAYS. ALTHOUGH THE SIGNAL FOR WIDESPREAD FLOODING REMAINS AMBIGUOUS...WILL HAVE TO WATCH CLOSELY EVOLVING QPF FORECASTS AND THE OBSERVED AND MODELED RATE OF SNOWMELT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER STORM WARNING UNTIL NOON EST TODAY FOR VAZ011-013-014- 017>020-022>024-032>035-043>047-058-059. NC...WINTER STORM WARNING UNTIL NOON EST TODAY FOR NCZ004>006. WV...WINTER STORM WARNING UNTIL NOON EST TODAY FOR WVZ043-044-507- 508. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...PW LONG TERM...JH/RCS AVIATION...PW HYDROLOGY...AMS/PC
AREA FORECAST DISCUSSION
NWS SEATTLE WA
928 AM PST TUE FEB 16 2016 .SYNOPSIS...A WARM FRONT OVER NORTHWEST OREGON WILL LIFT NORTHEAST ACROSS THE AREA LATE THIS AFTERNOON AND THIS EVENING. A LARGE UPPER LEVEL TROUGH WILL DEVELOP OFF THE COAST ON WEDNESDAY THEN MOVE THROUGH THE AREA ON THURSDAY. ANOTHER FRONT WILL ARRIVE ON FRIDAY. && .SHORT TERM...THE FRONT THAT BROUGHT HEAVY RAINFALL TO PORTIONS OF THE AREA OVER THE PAST COUPLE OF DAYS HAS MOVED DOWN INTO OREGON AND WEAKENED. IN RESPONSE TO DEVELOPING LOW PRESSURE NOW SEEN AT 47N 143W...THE FRONT WILL LIFT BACK TO THE NORTH ACROSS THE REGION LATER THIS AFTERNOON AND THIS EVENING. SHORT TERM MODELS SHOW FLOW ALOFT IS STILL WSW AND INFRARED SATELLITE IMAGERY SHOWS A GOOD DEAL OF MOISTURE OFF TO THE SW OF THE AREA THAT APPEARS TO BE POISED TO MOVE INTO THE AREA THIS AFTERNOON AND EVENING. THIS IS CONFIRMED BY THE LATEST HRRR SOLUTIONS THAT BRING PRECIPITATION NE TO AROUND SEATTLE BY 23Z AND NORTH INTO SOUTHERN PORTIONS OF THE NORTH INTERIOR BY 04Z. PRECIPITATION AMOUNTS IN THE LATEST HRRR AND GFS20 SOLUTIONS ARE ON THE ORDER OF 0.1 INCHES IN THE INTERIOR LOWLANDS AND 0.25 TO 0.5 INCHES ON THE COAST. AS A RESULT...POPS AND PRECIPITATION AMOUNTS WERE INCREASED FOR LATER THIS AFTERNOON AND EVENING...PARTICULARLY IN THE INTERIOR. WHILE IT IS PARTLY SUNNY IN PORT ANGELES EARLY THIS MORNING...MOST OF THE AREA IS SEEING LOW CLOUDS WITH SOME FOG AND AREAS OF DRIZZLE. AS A RESULT THE CLOUD COVER FORECAST WAS INCREASED FOR TODAY. THE WARM FRONT WILL LIFT INTO FAR NORTHERN PORTIONS OF WESTERN WASHINGTON LATE TONIGHT INTO WEDNESDAY MORNING. THE THE COLD FRONT ASSOCIATED WITH THE DEVELOPING OFFSHORE LOW WILL PUSH ONSHORE LATE WEDNESDAY AFTERNOON BRINGING ANOTHER INCREASE IN RAIN...ESPECIALLY ON THE COAST. FORECAST MODELS ARE QUITE INCONSISTENT WITH THE HANDLING OF THE OFFSHORE LOW AND POTENTIAL DEVELOPMENT OF A SECONDARY FEATURE OVER THE NORTHERN OREGON TO CENTRAL WASHINGTON COASTAL ZONES THAT WILL PUSH INLAND LATER THU. THE 00Z ECMWF AND 06Z GFS BOTH SHOWED EITHER THE OFFSHORE LOW OR POSSIBLY SOME SECONDARY DEVELOPMENT OVER THE SOUTH WASHINGTON OFFSHORE WATERS THAT WILL PUSH ONSHORE AS A 980- 990MB CENTER ON THE OLYMPIC PENINSULA. THIS TYPE OF SOLUTION WOULD GIVE RATHER WINDY CONDITIONS TO THE CENTRAL COAST AND POTENTIALLY TO THE PUGET SOUND LOWLANDS FROM ABOUT EVERETT SOUTHWARD LATE THURSDAY AFTERNOON. THE 12Z NAM12 TAKES A 990 MB LOW INTO SEASIDE OREGON THU AFTERNOON AND KEEPS WIND WELL SOUTH OF THE AREA. THE 12Z GFS20 TAKES THE MAIN 984 MB CENTER INTO QUEEN CHARLOTTE SOUND WITH A TRIPLE POINT FEATURE THAT MOVES INLAND AROUND SW WASHINGTON THAT LIFTS NE INTO THE CENTRAL CASCADES LATE THU AFTERNOON. THE 12Z GFS IS BREEZY TO WINDY...BUT NOT AS MUCH AS THE ECMWF. WITH ALL OF THE UNCERTAINTY...THE CURRENT FORECAST OF BREEZY CONDITIONS THU AFTERNOON AND EVENING WILL BE MAINTAINED FOR NOW. ALBRECHT .LONG TERM...FROM THE PREVIOUS LONG TERM DISCUSSION...EXTENDED MODELS ARE IN GOOD AGREEMENT WITH ANOTHER COLD FRONT MOVING THROUGH WESTERN WASHINGTON ON FRIDAY WITH A LITTLE BIT OF A BREAK IN THE ACTION ON SATURDAY AS A WEAK UPPER LEVEL RIDGE AHEAD OF THE NEXT FRONTAL SYSTEM ON SUNDAY. MODELS STILL GENERATING SOME LIGHT PRECIPITATION ON SATURDAY SO WILL KEEP CHANCE POPS IN THE FORECAST. TRAILING UPPER LEVEL TROUGH MOVING THROUGH ON MONDAY FOR A CHANCE OF SHOWERS. FELTON && .AVIATION...AT 9AM THERE IS SUNSHINE OVER MOST OF THE OLYMPICS AND ON THE NORTH COAST. THE AIR IS STILL MOIST AND CLOUDY FROM I-5 INTO THE CASCADES FOR THE MOST PART. A WEAK WARM FRONT OVER NW OREGON WILL LIFT NORTH THROUGH THE AREA THIS AFTERNOON AND EVENING. OFFSHORE FLOW WILL INCREASE TONIGHT AND WED...THEN ANOTHER FRONT ARRIVES LATER WED. KSEA...THERE SHOULD BE SOME IMPROVEMENT INTO THE EARLY AFTERNOON AND THEN A WEAK WARM FRONT ARRIVES LATE AFTERNOON FOR SEVERAL HOURS OF RAIN. LIGHT WIND. && .MARINE...A WEAK FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON AND EVENING. A VIGOROUS LOW PRESSURE SYSTEM WILL AFFECT THE AREA LATER WED THROUGH FRI WITH SEVERAL DISTURBANCES MOVING OUT OF THE LOW. && .HYDROLOGY...HYDROLOGICALLY SIGNIFICANT PRECIPITATION HAS COME TO AN END AS THE COLD FRONT THAT PRODUCED HEAVY RAINFALL MOVED INTO OREGON AND WEAKENED. MOST UNCONTROLLED RIVERS HAVE EITHER CRESTED OR WILL CREST THIS EVENING. SOME RIVERS ACROSS THE AREA REMAIN ABOVE FLOOD STAGE THIS MORNING. RIVERS WILL GENERALLY RECEDE LATER TODAY THROUGH THURSDAY. MODERATE PRECIPITATION IS EXPECTED WITH A VIGOROUS FRONTAL SYSTEM THAT WILL MOVE ACROSS THE AREA ON FRIDAY. HOWEVER SNOW LEVELS WILL GENERALLY BE AROUND 3000-4000 FEET AND THE FRONT WILL BE PROGRESSIVE. AT THIS TIME THE FRIDAY FRONT WILL LIKELY PRODUCE RISES ON AREA RIVERS...BUT RENEWED FLOODING IS NOT EXPECTED. ALBRECHT/BOWER && .CLIMATE...RAINFALL TOTAL AT SEATTLE-TACOMA AIRPORT THROUGH 3 AM THIS MORNING FOR THE MONTH OF FEBRUARY WAS 3.53 INCHES. THE NORMAL FOR THE ENTIRE MONTH OF FEBRUARY IS 3.50 INCHES. THE RAINFALL TOTAL FROM DECEMBER 1ST THROUGH 3 AM FEBRUARY 16TH WAS 22.19 INCHES. THE RECORD FOR THE MOST PRECIPITATION FROM DECEMBER 1ST THROUGH THE ENTIRE MONTH OF FEBRUARY IS 22.77 INCHES SET IN THE LA NINA YEAR OF 1998-1999. FELTON && .SEW WATCHES/WARNINGS/ADVISORIES... WA...FLOOD WATCHES OR WARNINGS ARE IN EFFECT FOR PORTIONS OF THE AREA. SEE THE LATEST FLOOD BULLETIN FOR DETAILS. PZ...SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL MIDNIGHT PST TONIGHT FOR GRAYS HARBOR BAR. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM PST WEDNESDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM-WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. && $$ WWW.WEATHER.GOV/SEATTLE YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
244 PM CST TUE FEB 16 2016 .TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS HIGH THE LAST OF A BAND OF LIGHT SNOW SHOWERS WILL MOVE OUT OF THE FORECAST AREA THIS EVENING AS A CLIPPER SYSTEM TRANSLATES THROUGH THE MISSISSIPPI RIVER VALLEY DOWN OVER THE SOUTHEASTERN UNITED STATES. NO ACCUMULATIONS ARE EXPECTED WITH THE REMAINING SNOW SHOWERS AS RAP AND NAM BUFKIT SOUNDINGS INDICATE DRYING WITHIN THE DENDRITIC SNOW GROWTH ZONE. AS THE LAST OF THE SNOW MOVES OUT...WINDS WILL VEER TO A MORE NORTHWESTERLY DIRECTION OVERNIGHT...WHICH SHOULD HELP ENHANCE COLD AIR ADVECTION...REDUCING TEMPERATURES. MODEL 925 MB TEMPERATURES LOOK TO BE GENERALLY BETWEEN -12 AND -7C...TAKING THE ECMWF...NAM...AND GFS MODELS INTO ACCOUNT. OVERNIGHT LOWS SHOULD RANGE FROM THE MID TO UPPER TEENS. CLOUDS LOOK TO SLOWLY DETERIORATE OVERNIGHT AS A DRIER AIR MASS SLOWLY MOVES IN FROM THE NORTH AFTER MIDNIGHT. SFC HIGH PRESSURE MOVING SOUTHEAST FROM MANITOBA WILL TRANSLATE OVER OUR REGION...KEEPING CONDITIONS QUIET FOR WEDNESDAY. EXPECTING PARTLY TO MOSTLY SUNNY SKIES DURING THE DAY WEDNESDAY...BUT HIGH TEMPERATURES WILL BE COOLER THAN THEY WERE TUESDAY AS HIGHS REACH INTO THE MID TO UPPER 20S. .WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH. HIGH PRESSURE WILL CONTINUE TO SLIDE OFF TO THE EAST. SOUTHERLY WINDS WILL BE INCREASING...BUT GENERALLY ABOVE A DECOUPLED BOUNDARY LAYER DURING THE OVERNIGHT HOURS. THE LOW TEMP WILL LIKELY OCCUR RIGHT AFTER SUNSET...THEN SLOWLY RISE AS ELEVATED WARM ADVECTION ARRIVES. DESPITE THE WAA...MOISTURE IS LIMITED...SO STILL DRY. .THURSDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM. A STRONG MID LEVEL SHORT WAVE WILL BEGIN TO KICK OUT OF THE NRN ROCKIES AND INTO THE WESTERN DAKOTAS BY LATE THU AFTERNOON. SFC CYCLOGENESIS WILL BEGIN ON THU OVR THE NRN HIGH PLAINS. THE INCREASING SOUTHERLY WINDS WILL BRING SUSTAINED AND VERY DEEP WARM AIR ADVECTION TO HIT WRN WI THU AFTN...THEN CONTINUES INTO EARLY FRIDAY MORNING. THERE/S A SMALL CHANCE OF LIGHT RAIN ACROSS THE WEST LATE THURSDAY AFTERNOON. BUT PRECIP CHANCES INCREASE AND SPREAD ACROSS THE REST OF SRN WISCONSIN OVERNIGHT INTO FRIDAY. THE BEST CHANCE WILL BE FOCUSED NORTH OF MILWAUKEE AND MADISON. TEMPS WILL STAY WARM ENOUGH TO KEEP IT ALL RAIN. THE TRACK OF THE SFC LOW HAS STRONG CONSENSUS AMONG THE MODELS...MOVING ACROSS THE U.P. OF MICHIGAN ON FRIDAY. THIS PUTS US SOLIDLY IN THE WARM SECTOR. THE SYSTEM WILL BE OCCLUDED...BUT IT/S POSSIBLE THE SFC WARM FRONT WILL GET JUST NORTH OF THE WI/IL STATE LINE BETWEEN 6-10AM FRI MORNING. IT STILL LOOKS LIKE WE WILL BE ABLE TO HIT THE LOWER AND POSSIBLY MID 50S FROM KJVL TO KENW. THE SFC TROUGH/COLD FRONT STRETCHING SOUTH FROM THE LOW WILL LIKELY MOVE ACROSS THE AREA BY MID DAY. THIS WILL BE FOLLOWED BY A SHOT COLD AIR ADVECTION THAT WILL LIKELY ONLY LOWER TEMPS A BIT DURING THE AFTERNOON. IF WE GET SOME CLEARING IN THE DRY SLOT BEHIND THE FRONT...WE MAY EVEN SEE TEMPS RISE A BIT. .FRIDAY NIGHT THRU SATURDAY NIGHT...FORECAST CONFIDENCE MEDIUM. HIGH PRESSURE BUILDS IN QUICKLY IN THE WAKE OF THE DEPARTING LOW. WE DON/T SEE STRONG COLD ADVECTION BEHIND THE LOW...SO SATURDAY IS SHAPING UP TO BE QUITE MILD AGAIN WITH HIGHS HITTING THE MID AND UPPER 40S. IF WE CAN GET MORE SUNSHINE...IT/S POSSIBLE WE COULD SEE SOME LOW 50S ACROSS THE SOUTH AGAIN. DRY THIS PERIOD. .SUNDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM. A VERY WEAK TROUGH DROPPING SOUTHEAST THROUGH THE GREAT LAKES WILL BRING US A SMALL CHANCE OF LIGHT PRECIP THROUGH THIS PERIOD. NOT MUCH IMPACT FOR SURE. TEMPS WILL BEGIN TO SINK CLOSER TO SEASONAL LEVELS ONCE THIS MOVES THROUGH BY MONDAY INTO TUESDAY. && .AVIATION/00Z TAFS/... MAINLY MVFR CONDITIONS...WITH THE POTENTIAL FOR IFR CIGS AND VSBYS...TO CONTINUE FOR THE REST OF THE AFTERNOON AS SOME FLURRIES/- SN CONTINUES TO MOVE THROUGH S WI. VSBYS WILL IMPROVE ONCE THE LIGHT SNOW MOVES OUT...WHICH SHOULD BE BETWEEN 6 AND 9 PM CST TONIGHT. ANY SNOW THAT FALLS WILL BE MORE OF THE DRY TYPE WITH SNOW-TO-LIQUID RATIOS OF 16:1 THIS EVENING AND OVERNIGHT. MODEL SOUNDINGS INDICATE LOW LEVEL LAPSE RATES WILL REMAIN STEEP OVERNIGHT...WHICH SHOULD KEEP LOW CIGS IN THE AREA...WITH CIG HEIGHTS BETWEEN 1-3 KFT POSSIBLE. NORTHWESTERLY WINDS WILL SLOWLY VEER TO A MORE NORTHERLY DIRECTION BY WEDNESDAY MORNING...WITH MORE NORTHEAST TO EASTERLY WINDS POSSIBLE DURING THE DAY WEDNESDAY AS AN AREA OF HIGH PRESSURE MOVES IN FROM CANADA. EXPECT VFR SKY CONDITIONS DURING THE DAY WEDNESDAY AS SKIES WILL CHANGE FROM OVC/BKN CATEGORIES OVERNIGHT TO SCT/FEW AS A DRIER AIR MASS ASSOCIATED WITH THE SFC HIGH PRESSURE MOVES IN. && .MARINE... GUSTY WINDS AND HIGH WAVES ARE POSSIBLE THURSDAY INTO FRIDAY NIGHT ACROSS THE NEARSHORE WATERS OF LAKE MICHIGAN...AS LOW PRESSURE PASSES BY TO THE NORTHWEST OF THE AREA. GUSTS COULD BE BETWEEN 25- 30 KTS THURSDAY AFTERNOON AND EVENING. A TIGHT PRESSURE GRADIENT IS EXPECTED DURING THIS TIME...WHICH SHOULD BRING THESE GUSTY WINDS AND BUILDING WAVES. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR THIS PERIOD IN LATER FORECASTS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TONIGHT/WEDNESDAY AND AVIATION/MARINE...JTS WEDNESDAY NIGHT THROUGH TUESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1129 PM CST MON FEB 15 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 322 PM CST MON FEB 15 2016 PRIMARY CONCERNS INVOLVE FOG AND SNOW CHANCES/AMOUNTS TONIGHT THROUGH TUESDAY. 15.12Z MODEL SUITE IN GOOD OVERALL AGREEMENT AND WILL FOLLOW A BLENDED SOLUTION...ALTHOUGH FOCUS FOR THE NEXT 6 TO 12 HOURS WILL BE ON THE LATEST RAP/HRRR OUTPUT. 15.20Z WATER VAPOR LOOP SHOWS A WEAK SHORT-WAVE MOVING ACROSS CENTRAL MN AND THIS HAS RESULTED IN A COMPACT AREA OF SNOW SHOWERS NOW MOVING INTO SOUTHEAST MN. 15.20Z HRRR SHOWS THESE SHOWERS MOVING EAST INTO THE EARLY EVENING AND THEN FALLING APART NEAR THE MS RIVER. WITH SFC OBS UNDER THIS SNOW REPORTING VISIBILITY FROM 3 TO 5SM...A QUICK DUSTING IS POSSIBLE LATE THIS AFTERNOON/EARLY EVENING. BIGGER CONCERN THIS EVENING IS FOG POTENTIAL. WITH MOIST WARM AIR ADVECTION REGIME OVER THE SNOWPACK AND RELATIVELY LIGHT NEAR SURFACE FLOW...THINK THERE COULD BE A REPEAT FROM THIS MORNING WITH RAPIDLY DEVELOPING FOG AFTER SUNSET. THIS IS ESPECIALLY TRUE IF THE LIMITED CLEARING AREA ACROSS CENTRAL MN CAN WORK ITS WAY INTO THE FORECAST AREA AND ALLOW FOR GREATER NOCTURNAL COOLING. AREAS OF DENSE FOG A REAL POSSIBILITY...BUT TIMING/COVERAGE UNCERTAIN AND SOMETHING TO WATCH THROUGHOUT THE EVENING FOR POSSIBLE ADVISORY CONDITIONS. FOR NOW...WILL EXPAND PATCHY/AREAS OF FOG FROM WEST TO EAST THIS EVENING AND OVERNIGHT. ANY FOG THAT DOES DEVELOP IS NOT LIKELY TO DISSIPATE UNTIL SOMETIME TUESDAY MORNING AT THE EARLIEST. TEMPERATURES TONIGHT WILL BE WARM... GENERALLY IN THE UPPER TEENS TO MID 20S ABOVE ZERO. 15.12Z GLOBAL MODELS NOW IN GOOD AGREEMENT...SHOWING THE NEXT SHORT-WAVE ALOFT FOR TONIGHT DIVING TO THE SOUTH AND WEST OF THE FORECAST AREA. BEST 500 TO 300 HPA POSITIVE VORTICITY ADVECTION AND MID-LEVEL FRONTOGENESIS WITH THIS WAVE IS BETTER ALIGNED ALONG THE MO RIVER VALLEY WHERE A FEW INCHES OF SNOW ARE POSSIBLE. A SECONDARY WEAKER SHORT-WAVE/SURFACE COLD FRONT WILL MOVE ACROSS THE FORECAST AREA LATER TONIGHT THROUGH TUESDAY...BRINGING A CHANCE FOR LIGHT SNOW ACROSS MUCH OF REGION. HOWEVER...LIFT AND MOISTURE ARE RATHER UNIMPRESSIVE. NAM BUFKIT SOUNDINGS IN PARTICULAR LACK ICE FOR MUCH OF THE PERIOD...WHEREAS THE GFS SHOWS A DEEPER SATURATED LAYER. WILL NEED TO WATCH FOR POSSIBLE FREEZING RAIN/DRIZZLE...BUT FOR NOW THINK THE NAM IS UNDER DOING COLDER CLOUDS ALOFT AND WILL KEEP PRECIPITATION TYPE AS SNOW. IF SNOW DOES DEVELOP WITHIN WEAK LIFT REGIME...ACCUMULATIONS WILL GENERALLY BE AN INCH OR LESS REGION-WIDE. TEMPERATURES TUESDAY WILL AGAIN HINGE ON CLOUD COVER...BUT SHOULD RISE INTO THE LOWER 30S MOST AREAS PRIOR TO THE COLD FRONTAL PASSAGE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 322 PM CST MON FEB 15 2016 TUESDAY NIGHT THROUGH THURSDAY LOOK MAINLY DRY AS BROAD SURFACE HIGH PRESSURE DOMINATES THE REGIONAL WEATHER PATTERN. A SLIGHTLY COOLER AIR MASS ON WEDNESDAY IN THE WAKE OF TUESDAY/S COLD FRONT WILL KEEP TEMPERATURES MAINLY IN THE 20S. HOWEVER...A MUCH DRIER AIR MASS SHOULD LEND ITSELF TO SOME SUNSHINE FOR AT LEAST THE LATTER HALF OF THE DAY. SIGNIFICANT WARM AIR ADVECTION ENSUES AFTER 06Z THURSDAY SO THAT BY 06Z FRIDAY...925 HPA TEMPERATURES RANGE FROM +3 TO +7 CELSIUS. ALTHOUGH DEPENDENT ON CLOUD COVER... TEMPERATURES THURSDAY SHOULD CLIMB INTO THE MID TO UPPER 30S. ATTENTION THEN TURNS TO THURSDAY NIGHT INTO FRIDAY AS THE NEXT PACIFIC TROUGH LIFTS INTO THE UPPER MIDWEST. 15.12Z GFS/ECMWF ARE IN BETTER AGREEMENT WITH THIS SYSTEM...ALTHOUGH THE GFS SURFACE LOW TRACK IS A BIT FURTHER NORTH. THE GFS IS ALSO MORE BULLISH ON QPF MAINLY THURSDAY NIGHT IN THE SYSTEM/S WARM SECTOR. STILL NEED TO WATCH POTENTIAL FOR SOME MIXED FREEZING PRECIPITATION THURSDAY NIGHT FOR AREAS NORTH OF I-94 THAT HAVE SUB-FREEZING SURFACE TEMPERATURES. DEGREE OF WARMTH ON FRIDAY A BIT MORE UNCERTAIN NOW AS BOTH MODELS ALIGN THE SURFACE COLD FRONT ALONG THE MS RIVER BY 12Z FRIDAY. HOWEVER...OVERALL POST-FRONTAL THERMAL PROFILE REMAINS WARM ENOUGH SO THAT PRECIPITATION FALLS AS RAIN. FOR NOW...EXPECT TEMPERATURES INTO THE 40S WITH CONSENSUS 30 TO 60 POPS. A DRY AND WARM SATURDAY GIVES WAY TO ANOTHER SHOT OF PRECIPITATION SUNDAY AS A SHORT-WAVE DROPS SOUTH FROM CANADA. TOO FAR OUT TO PROVIDE MANY DETAILS...BUT PRECIPITATION TYPE SHOULD BE MAINLY LIQUID. MONDAY DRIES OUT AND COOLS BACK DOWN ON THE BACKSIDE OF DEPARTING WAVE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1129 PM CST MON FEB 15 2016 THROUGH MID MORNING TUESDAY...PLAN ON MVFR TO LIFR CONDITIONS AT KRST WITH MVFR TO IFR CONDITIONS EXPECTED A KLSE. A WEAK UPPER LEVEL DISTURBANCE AND COLD FRONT WILL PUSH ACROSS THE TAF SITES TUESDAY MORNING BRINGING A ROUND OF LIGHT SNOW...AND POSSIBLY SOME PATCHY FREEZING DRIZZLE. LOW STRATUS AND BR WILL ALSO BE A CONCERN WITH CEILINGS FALLING TO AROUND 400 FT AT KRST AND TO 800 FT AT KLSE. VISIBILITIES COULD FALL TO AROUND 1SM AT TIMES IN FOG AND BR. LOOK FOR CONDITIONS TO IMPROVE TO MVFR TUESDAY EVENING IN THE WAKE OF THE COLD FRONT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...WETENKAMP SHORT TERM...ROGERS LONG TERM...ROGERS AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1105 PM MST MON FEB 15 2016 .UPDATE... ISSUED AT 1105 PM MST MON FEB 15 2016 WINDS HAVE BEEN ON THE STEADY DECLINE THIS EVENING AS THE COLD FRONT MARCHES SOUTH ACROSS THE PLAINS...SO CANCELLED THE WIND HIGHLIGHTS FOR THE NON-WIND PRONE AREAS EARLIER. SNOTELS DO NOT INDICATE THE MOUNTAINS ARE RECEIVING MUCH SNOW THIS EVENING...SO WILL ALLOW THE SNOW ADVISORY TO EXPIRE ON TIME. OTHERWISE...WILL CONTINUE TO SEE THE BAND OF RAIN/SNOW SHOWERS STEADILY TREK SOUTH THROUGH SHORTLY AFTER MIDNIGHT BEFORE DISSIPATING. WINDS WILL REMAIN ON THE BREEZY SIDE OVERNIGHT...BUT WILL INCREASE THROUGH TUESDAY MORNING IN THE WIND PRONE AREAS WHERE A HIGH WIND WARNING REMAINS IN EFFECT. && .SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT) ISSUED AT 403 PM MST MON FEB 15 2016 WIDESPREAD HIGH WIND EVENT IS CURRENTLY PEAKING OVER MUCH OF SOUTHEAST WYOMING. MANY LOCATIONS IN THE WARNED AREA HAVE BEEN GUSTING TO 50-60 KTS SINCE MIDDAY. PRESSURE FALLS AHEAD OF THE SHORTWAVE OVER SOUTHEAST MONTANA IS RESPONSIBLE FOR THE STRONG LLVL GRADIENT. THE MODELS SHOW THE 850 MB CAG-CPR GRADIENT ABOVE 70 METERS THROUGH 03Z..AND THEN DECREASING TO AROUND 60. EXTENDED THE HIGH WIND WARNING TO EAST LARAMIE COUNTY AND ISSUED A WIND ADVISORY FOR KIMBALL COUNTY THROUGH THE EVENING. WINDS WILL DECREASE BY 03-06Z AS THE PRESSURE GRADIENT WEAKENS BEHIND THE FROPA. WITH THE CAG-CPR GRADIENT REMAINING NEAR 60 THROUGH TUES AFTN...DECIDED TO EXTEND THE HIGH WIND WARNING OVER THE WIND PRONE AREAS THROUGH THAT TIME. THERE WILL BE A NOTABLE DECREASE IN WINDS EARLY TONIGHT THROUGH TUESDAY MORNING...THEN PRESSURE FALLS OCCUR TO THE EAST OF THE LARAMIE RANGE BY LATE TUES MORNING. THIS WILL LIKELY BE A MARGINAL EVENT WITH GUSTS TO 50-60 MPH. RADAR IMAGERY SHOWS A BAND OF RAIN SHOWERS STRETCHING FROM DOUGLAS TO SCOTTSBLUFF. THE HRRR SHOWS BANDS OF SHOWERS PERSISTING THROUGH THE EVENING OVER AREAS TO THE EAST OF THE LARAMIE RANGE. THE GFS DOES SHOW WEAK FRONTOGENESIS AND INSTABILITY...SO THIS MAKES SENSE. THE QUESTION WILL BE HOW MUCH OF THIS PRECIP WILL FALL AS SNOW BY LATER THIS EVENING. CURRENT THINKING IS A RAIN/SNOW MIX WILL BE FOUND IN THE SHOWERS ACROSS THE PLAINS AND IMPACTS WILL BE LOW...BUT THIS WILL HAVE TO BE WATCHED BY THE EVENING SHIFT. THE NICEST DAY OF THE WEEK IS STILL LOOKING LIKE WEDNESDAY AS THE RIDGE AXIS MOVES OVERHEAD AND WINDS WEAKEN AND BECOME MORE SOUTHERLY/SOUTHWESTERLY. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 403 PM MST MON FEB 15 2016 MAIN WEATHER CONCERNS THROUGH THE EXTENDED PERIOD WILL REMAIN FOCUSED ON THE POTENTIAL FOR STRONG WINDS. THURSDAY AFTERNOON AND EVENING LOOKS PARTICULARLY WINDY. BASED ON CURRENT MODEL DATA...WIND SPEEDS ON THURSDAY SHOULD BE SIMILAR TO THAT OF TODAY. ACTUALLY WINDS COULD BE SLIGHTLY STRONGER THAN TODAY AND MORE WIDESPREAD. STRONG WINDS MAY EVEN SPREAD INTO THE NEBRASKA PANHANDLE. CHANCES FOR PRECIPITATION WILL BE LIMITED THROUGH THE WEEKEND. THE MAIN CHANCE FOR MEASURABLE PRECIPITATION WILL OCCUR WEST OF THE LARAMIE RANGE...PARTICULARLY INTO THE SNOWY AND SIERRA MADRE RANGES WHERE SEVERAL INCHES OF SNOW MAY OCCUR THURSDAY. WINDY CONDITIONS WILL PERSIST THROUGH THE WEEKEND...ESPECIALLY OVER THE WIND PRONE PORTIONS OF SOUTHEAST WYOMING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1105 PM MST MON FEB 15 2016 WINDS WILL REMAIN BREEZY AT TIMES THROUGH THE PERIOD OVER MUCH OF THE FORECAST AREA. A BAND OF RAIN/SNOW SHOWERS MAY AFFECT KCYS AND KLAR THROUGH ROUGHLY 08Z BEFORE DISSIPATING THROUGH THE REMAINDER OF THE OVERNIGHT PERIOD. COULD SEE A PERIOD OF MVFR CONDITIONS IN THE PRECIPITATION. && .FIRE WEATHER... ISSUED AT 403 PM MST MON FEB 15 2016 TEMPERATURES WILL BE MUCH ABOVE NORMAL FOR THIS TIME OF THE YEAR THROUGH THURSDAY AND FRIDAY. IT WILL BE WINDY THROUGH MOST OF THIS WEEK. AN ELEVATED FIRE WEATHER THREAT WILL BE POSSIBLE ON THURSDAY AND FRIDAY TO THE EAST OF THE LARAMIE RANGE AS MINIMUM RELATIVE HUMIDITY DROPS TO AROUND 25 PERCENT AND GUSTY WINDS OCCUR. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...HIGH WIND WARNING UNTIL 5 PM MST TUESDAY FOR WYZ106-110-116-117. NE...NONE. && $$ UPDATE...RJM SHORT TERM...ZF LONG TERM...SML AVIATION...RJM FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
235 AM MST THU FEB 18 2016 .SYNOPSIS... A TURN TOWARDS SOMEWHAT COOLER TEMPERATURES AND AN INCREASE IN CLOUDINESS IS ON TAP TODAY AND FRIDAY...AS A UPPER LEVEL LOW PRESSURE SYSTEM MOVES OFF TO OUR NORTH ACROSS THE GREAT BASIN. HOWEVER...TEMPERATURES ARE AGAIN EXPECTED TO WARM WELL BACK UP INTO THE 80S FROM THIS WEEKEND ONWARD INTO AT LEAST THE MIDDLE PART OF NEXT WEEK...AS STRONG HIGH PRESSURE REBUILDS OVER THE DESERT SOUTHWEST. && .DISCUSSION... TODAY THROUGH FRIDAY... AFTER A VERY WARM DAY ON WEDNESDAY...WHICH SAW THE EARLIEST 90 DEGREE HIGH ON RECORD AT PHOENIX SKY HARBOR...A TURN TOWARDS SOMEWHAT COOLER TEMPERATURES IS STILL EXPECTED TODAY AND FRIDAY...AS THE VERY STRONG UPPER-LEVEL RIDGE THAT BROUGHT US THE VERY WARM WEATHER IS FLATTENED BY AN UPPER TROF THAT IS NOW MOVING INLAND INTO THE WESTERN GREAT BASIN. ALTHOUGH THE SFC COLD FRONT CAN BE SEEN ON LATEST SATELLITE/RADAR IMAGERY MOVING EASTWARD ACROSS SE CA THIS MORNING...VIRTUALLY ALL OF THE RAINFALL ASSOCIATED WITH THE FRONT IS PASSING OFF TO THE NORTH OF OUR CWA...WITH JUST A FEW SPRINKLES PERHAPS REACHING THE GROUND OVER THE HIGHER ELEVATIONS OF JOSHUA TREE NATIONAL PARK. THE LATEST HRRR IS SHOWING VIRTUALLY NO RAINFALL WILL MAKE IT TO THE LOWER ELEVATIONS OF SE CA AS THE SFC FRONT CONTINUES TO WEAKEN AS MOST OF THE DYNAMICS/MOISTURE SHIFT OFF TO THE NORTH AS THE MAIN TROF LIFTS OUT TO THE NE. THE MAIN IMPACTS FOR MOST OF OUR CWA WILL BR A INCREASE IN MID AND HIGH-LEVEL CLOUDINESS AND SLIGHT COOLING ALOFT (500MB TEMPS FALLING FROM AROUND -8C TO 12C)...WHICH IS EXPECTED TO RESULT IN ABOUT A 8-10F COOLING OF OUR HIGH TEMPERATURES FROM WEDNESDAY/S VALUES...TAKING LOWER DESERT HIGHS DOWN INTO THE LOWER 80S ON BOTH DAYS. ON FRIDAY...THE GFS...NAM...AND SREF ARE ALL SHOWING A PLUME OF SUBTROPICAL MOISTURE MOVING INTO SW AND SOUTH-CENTRAL AZ...AS A VERY WEAK SHORTWAVE THAT IS EMBEDDED IN BROAD MID-LEVEL SW-LY FLOW MOVES INTO THE AREA. ALTHOUGH PWATS DO BRIEFLY SURGE UP INTO THE 0.70-0.90 INCH RANGE AS THE SHORTWAVE PASSES THROUGH...ONLY VIRGA OR LIGHT SPRINKLES ARE EXPECTED...SINCE MOST MOISTURE IS EXPECTED TO REMAIN AOA 600MB...WITH VIRTUALLY ALL OF THE NCEP SREF PLUMES SHOWING NO MEASURABLE PRECIP AT PHOENIX. SATURDAY THOUGH NEXT THURSDAY... THERE CONTINUES TO BE VERY GOOD CONSENSUS BETWEEN THE MAIN GLOBAL MODEL SUITES AND MANY OF THEIR RESPECTIVE MEMBERS ON THE FORECAST FOR THIS PERIOD. THEY ALL ARE BUILDING VERY STRONG RIDGING NORTHWARD ALONG THE WEST COAST AND INTO THE DESERT SOUTHWEST...AS A DEEP LONGWAVE TROF DROPS SOUTHWARD INTO THE CENTRAL/EASTERN CONUS. THE RESULT IS A DRY FORECAST FOR THE ENTIRE PERIOD...WITH LOWER DESERT HIGHS ONCE AGAIN RISING UP INTO THE MIDDLE/UPPER 80S...UNDER MOSTLY SUNNY SKIES. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE FROM THE WEST OVERNIGHT AHEAD OF AN APPROACHING UPPER LEVEL TROUGH AND ASSOCIATED SFC FRONT. TYPICAL DRAINAGE AND DIURNALLY DRIVEN WINDS WILL PRESENT AT THE SFC OVERNIGHT...HOWEVER WINDS OFF SFC MAY MAINTAIN SOUTH TO SOUTHWESTERLY HEADINGS LONGER INTO THE EVENING WITH SPEEDS OF 20KTS OR SO. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... ELEVATED WINDS WILL CONTINUE OVERNIGHT...WESTERLY AT KIPL AND SOUTHERLY AT KBLH...AHEAD OF AN ADVANCING SFC FRONT. WIND SPEEDS WILL RANGE 10 TO 15KTS SUSTAINED WITH OCCASIONAL GUSTS OF 20KTS. BKN-OVC MID LEVEL CLOUDS WILL CONTINUE TO INCREASE FROM THE WEST WITH SOME ISOLATED LIGHT RAIN SHOWER ACTIVITY POSSIBLE MAINLY ACROSS EASTERN RIVERSIDE COUNTY OVERNIGHT. SOME LOWERED CLOUD DECKS...5-7KFT...COULD DEVELOP FOR KIPL LATER BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE MENTION IN 18/06Z TAFS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... FRIDAY THROUGH TUESDAY... WHILE SOMEWHAT COOLER WEATHER WILL BE SETTLED ACROSS THE DISTRICT FRIDAY...NEAR RECORD SETTING WARMTH WILL REGAIN A FOOTHOLD ON THE REGION THROUGH THE WEEKEND AND EARLY NEXT WEEK. DRY CONDITIONS WILL ALSO PREDOMINATE...ALTHOUGH A SPRINKLE WOULD NOT BE UNUSUAL OVER SRN GILA COUNTY FRIDAY AFTERNOON. MINIMUM HUMIDITY LEVELS TEMPORARILY IN A 15 TO 30 PERCENT RANGE THIS WEEK WILL FALL BACK TO THE TEENS EARLY NEXT WEEK. WINDS WILL GENERALLY REMAIN WEAK WITH THE TYPICAL DIURNAL UPSLOPE/DRAINAGE COMPONENT...HOWEVER PERIODS OF GUSTY NORTHERLY WINDS MAY BE COMMON THROUGHOUT THE LOWER COLORADO RIVER VALLEY EARLY NEXT WEEK. && .CLIMATE... PHOENIX | YUMA FCST | RECORD /YEAR/ | FCST | RECORD /YEAR/ HIGH HIGH THU FEB 18 82 | 86 /2014 | 83 | 90 /1981 && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA AVIATION...NOLTE FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS EUREKA CA
1042 PM PST WED FEB 17 2016 .SYNOPSIS...COLD FRONTS WILL BRING PERIODS OF MODERATE RAIN AND SHOWERS...GUSTY WINDS...AND HIGH ELEVATION SNOW TONIGHT THROUGH FRIDAY. A GRADUAL WARMING AND DRYING TREND IS EXPECTED SATURDAY THROUGH THE MIDDLE OF NEXT WEEK...HOWEVER PERIODS OF LIGHT RAIN CAN BE EXPECTED SUNDAY AND TUESDAY. && .UPDATE...ACCUMULATING SNOW HAS BEEN REPORTED AS LOW AS 2700 FEET THIS EVENING SO HAVE UPDATED THE FORECAST. LOWERED THE WINTER WEATHER ADVISORY TO 3000 FEET AND ADDED THE MENDOCINO INTERIOR TO IT. THERE IS A LULL IN THE SHOWERS NOW BUT THE NAM AND HRRR SHOWS SHOWERS PICKING UP AGAIN OVER THE NEXT FEW HOURS AS THE UPPER LEVEL TROUGH MOVES ONSHORE. THE ADVISORY NOW INCLUDES BUCKHORN SUMMIT ON HWY 299 AND PORTIONS OF HWY 3 AND 36. BERRY SUMMIT AND OREGON MAY SEE SOME SNOW...BUT ACCUMULATIONS ARE EXPECTED TO BE LESS THAN AN INCH. MKK && .PREV DISCUSSION......ISSUED AT 739 PM PST... UPDATE...SNOW LEVELS DROPPED A BIT MORE QUICKLY THAN EXPECTED. SO UPDATED THE FORECAST TO LOWER SNOW LEVELS TO 2500 TO 3000 FEET LATER TONIGHT. SNOW WAS REPORTED FALLING AT 2500 FT IN KNEELAND AND THE SURFACE TEMPERATURES SUPPORTED THIS. WITH THE RECENT WARM TEMPERATURES THE GROUND IS LIKELY FAIRLY WARM. THIS IS EXPECTED TO KEEP ACCUMULATING SNOW ABOVE 3000 FEET AND SIGNIFICANT ACCUMULATION ABOUT 3500 FT. SO WILL LEAVE THE ADVISORY THE SAME. IF THE GROUND COOLS OFF MORE THAN EXPECTED THE ADVISORY MAY NEED TO BE LOWERED. IN MENDOCINO COUNTY SNOW WAS REPORTED AS STICKING AT 4000 FEET...BUT ONLY A FEW OF THE HIGHEST PEAKS MAY REACH ADVISORY LEVEL SO HELD OFF ON ISSUING AN ADVISORY. MKK PREV DISCUSSION......ISSUED AT 354 PM PST... DISCUSSION...WEATHER IS BECOMING MUCH MORE ACTIVE ACROSS NORTHWEST CALIFORNIA THIS AFTERNOON AS AN IMPRESSIVE TROUGH AND COLD FRONT GRADUALLY MOVES ONTO THE COAST. AS THE FRONT MOVED ONTO THE COAST EARLY THIS AFTERNOON...GUSTY WINDS WERE ABLE TO MIX DOWNWARD ALONG THE LEADING EDGE OF THE FRONTAL PRECIPITATION BAND WITH GUST SPEEDS REACHING APPROXIMATELY 40 TO 50 MPH ALONG THE IMMEDIATE COAST. THIS WAS IN ADDITION TO THE GUSTY INTERIOR RIDGETOP WINDS THAT PERSISTED MUCH OF THE DAY TODAY...PROMPTING THE ISSUANCE OF A WIND ADVISORY EARLY THIS MORNING. WIND SPEEDS ARE QUICKLY DROPPING BELOW ADVISORY CRITERIA BEHIND THE LEADING EDGE OF THE PRECIPITATION AND COLD FRONT...AND THUS THE WIND ADVISORY WAS ALLOWED TO EXPIRE. OVER THE NEXT FEW HOURS...THE PRIMARY BAND OF MODERATE STRATIFORM RAIN ASSOCIATED WITH THE COLD FRONT WILL CONTINUE TO MOVE INLAND. MEANWHILE...SNOW LEVELS ARE QUICKLY DROPPING NEAR THE COAST...AND WILL LIKELY FALL TO AROUND 4000 FEET THIS EVENING NEAR THE BACK EDGE OF THE FRONTAL PRECIPITATION BAND...AND EVENTUALLY TO AROUND 3000 TO 3500 FEET BY TOMORROW MORNING. AFTER WHAT WILL LIKELY BE A 2 TO 3 HOUR LULL IN PRECIPITATION...WAVES OF VIGOROUS SHOWERS WILL MOVE ONTO THE COAST AND INLAND...RESULTING IN HIGH ELEVATION SNOW AND PERHAPS A FEW THUNDERSTORMS WITH SMALL HAIL NEAR THE COAST. THIS SHOWER ACTIVITY WILL CONTINUE THROUGH TOMORROW AFTERNOON...WITH A SURGE IN ACTIVITY LIKELY EARLY TOMORROW MORNING. SHOWERS WILL TAPER OFF LATE TOMORROW...HOWEVER SOME AREAS NEAR THE COAST MAY SEE SCATTERED SHOWERS CONTINUE RIGHT UP UNTIL THE NEXT COLD FRONT ARRIVES EARLY FRIDAY. AS FOR THE WINTER WEATHER ADVISORY...NO CHANGES WERE MADE AS THE SNOW FORECAST REMAINS ON TRACK. EXPECT 2 TO 5 INCHES OF SNOW BETWEEN 3500 AND 4500 FEET ELEVATION...WITH TOTALS APPROACHING A FOOT AT ELEVATIONS ABOVE 4500 FEET. A FEW FLAKES TO PERHAPS A DUSTING OF SNOW WILL ALSO BE POSSIBLE TONIGHT AND TOMORROW MORNING TO AS LOW AS 2500 TO 3000 FEET...HOWEVER TEMPERATURES ARE LIKELY TO BE TOO WARM TO CAUSE SIGNIFICANT TRAVEL IMPACTS BELOW 3500 FEET...IE AT BERRY AND OREGON MOUNTAIN SUMMIT PASSES ON HIGHWAY 299. THE NEXT COLD FRONT AND NEGATIVELY TILTED SHORTWAVE WILL ARRIVE AT THE COAST EARLY FRIDAY...BRINGING WITH IT ANOTHER ROUND OF MODERATE RAIN...GUSTY WINDS...AND HIGH ELEVATION SNOW ABOVE 4000 FEET. ALL IN ALL...BETWEEN THE TWO SYSTEMS TOTAL RAINFALL WILL BE SIGNIFICANT ENOUGH TO BE BENEFICIAL TO THE REGION...BUT NOT ENOUGH TO CAUSE ANY FLOODING CONCERNS. AN ADDITIONAL WIND ADVISORY MAY BE NEEDED IN FUTURE FORECASTS FOR EARLY FRIDAY AS WELL. AFTER FRIDAY...A BUILDING RIDGE ACROSS THE WESTERN U.S. WILL BRING A RETURN TO OVERALL DRIER AND WARMER THAN NORMAL CONDITIONS TO THE REGION. GLANCING BLOWS OF LIGHT RAIN CAN BE EXPECTED SUNDAY AND AGAIN TUESDAY/WEDNESDAY...HOWEVER THESE SYSTEMS WILL WEAKEN AS THEY APPROACH THE COAST AND RAINFALL TOTALS ARE EXPECTED TO BE GENERALLY LIGHT. /BRC AVIATION...AN ACTIVE WEATHER PATTERN WILL ALLOW STRONGER WIND GUSTS UP TO 30-40KTS TO CONTINUE THROUGH 0Z BEFORE SLIGHTLY WEAKENING FOR THE EVENING DUE TO THE COLD FRONT MOVING THROUGH. WITH THESE WINDS COMBINED WITH THE RAIN TERMINALS SHOULD STAY IN VFR TO MVFR DURING THIS TIME FRAME. IF HEAVIER BANDS OF RAIN OR STRONGER SHOWERS PASS THROUGH...IFR CONDITIONS ARE NOT OUT OF THE QUESTION. ONCE THE FRONT EXITS A TROUGH WILL TRACK OVER US. PRECIP WILL CONTINUE BUT MAY BE SHOWERY IN NATURE. CURRENT THINKING IS THAT WE WILL LIKELY STAY IN VFR AND MVFR CONDITIONS FOR THE OVERNIGHT...THERE IS A POSSIBILITY THAT WE COULD SEE IFR CRITERIA AGAIN BUT THAT WILL DEPEND ON THE INTENSITY OF THE PRECIP. MARINE...A PASSING FRONT BROUGHT STRONG, GUSTY WINDS TO THE WATERS TODAY WITH THE NEARSHORE BUOYS REPORTING 45 KT GUSTS LATE THIS AFTERNOON. WINDS SHOULD REMAIN FRESH AND SOUTHERLY TONIGHT AND EASE SLIGHTLY LATER THURSDAY. FEW GALE FORCE GUSTS WILL BE POSSIBLE DURING THIS TIME FRAME AS THE OVERHEAD TROUGH MAINTAINS A TIGHT PRESSURE GRADIENT AGAINST THE INTERIOR SURFACE RIDGE SO SMALL CRAFT ADVISORIES SHOULD SUFFICE FOR THE TIME BEING. THE NEXT FRONTAL BOUNDARY IS FORECAST TO BRING STRONGER GUSTS TO THE WATERS LATE THURSDAY NIGHT THROUGH EARLY FRIDAY MORNING. A GALE WARNING WAS ISSUED FOR THE NORTHERN WATERS AND THE SOUTHERN OUTER WATERS AS WIND GUSTS ARE FORECAST TO REACH 45 KT. SOME STORM FORCE GUSTS MAY BE POSSIBLE BUT THERE IS NOT ENOUGH CONFIDENCE THAT WINDS OF THIS MAGNITUDE WILL MIX TO THE SURFACE. THE STRONGEST WINDS, HOWEVER, SHOULD BE MOSTLY NORTH OF CAPE MENDOCINO AS THE FRONT LIFTS OVER THE REGION. MEANWHILE, A WESTERLY SWELL WILL CONTINUE TO BUILD ACROSS THE WATERS TONIGHT AND PEAK NEAR 16 TO 18 FT EARLY THURSDAY. THEN LARGE, STEEP WAVES WILL BUILDING IN RESPONSE TO THE INCREASING WINDS THURSDAY NIGHT AND FRIDAY MORNING. MARINE CONDITIONS WILL THEN SETTLE OVER THE WEEKEND AS HIGH PRESSURE MOVES OVER THE WESTERN UNITED STATES. KML && .EKA WATCHES/WARNINGS/ADVISORIES... CA... WINTER WEATHER ADVISORY UNTIL 4 PM PST THURSDAY ABOVE 3000 FEET FOR CAZ003-004-076. NORTHWEST CALIFORNIA COASTAL WATERS... SMALL CRAFT ADVISORY UNTIL 9 PM PST THURSDAY FOR PZZ450-470-475. GALE WARNING FROM 9 PM THURSDAY TO 3 PM PST FRIDAY FOR PZZ450-470. GALE WARNING FROM 9 PM THURSDAY TO 9 AM PST FRIDAY FOR PZZ475. SMALL CRAFT ADVISORY UNTIL 9 PM PST SATURDAY FOR PZZ455. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/NWSEUREKA HTTP://WWW.TWITTER.COM/NWSEUREKA FOR FORECAST ZONE INFORMATION SEE FORECAST ZONE MAP ONLINE: HTTP://WWW.WEATHER.GOV/EUREKA/ZONEMAP.PNG
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
323 AM CST THU FEB 18 2016 .SHORT TERM...(Today and Tonight) Issued at 323 AM CST THU FEB 18 2016 High clouds on water vapor imagery were noted lifting over the upper ridge building into the western high plains this morning. A broad and strong upper trough entering the Pac NW was streaming steady moisture off the southern CA coast towards the southwest Conus. Sfc Observations showed the developing lee trough across eastern CO inducing southerly winds to increase between 10 and 15 mph. Low level moisture across southern TX was quickly advecting northward with a strong 50+ kt low level jet ongoing and anticipated to increase after sunrise. This low level moisture advection is a major factor as to how low RH readings fall during the late afternoon as a stout dryline mixes eastward across KS. Fire weather details follow below on the current thinking. Forecast was based on a combination of the RAP and HRRR (previous and current runs) with the low 40 degree dewpoints and highs in the lower 70s for east central/north central areas. North central KS may be able to mix out to the upper 70s as forecast soundings are consistent in the warm inversion layer reaching the sfc in addition to the drier air. Wind speeds are also of concern with speeds expected to increase shortly after sunrise between 25 and 35 mph sustained with gusts between 40 and 50 mph possible. For this reason, have expanded the wind advisory for areas generally along and south of Interstate 70. For tonight, winds are expected to stay up between 15 and 25 mph sustained as they veer to the west with the upper trough crossing over Nebraska. High clouds increase while temps stay mild in the lower 50s. .LONG TERM...(Friday through Wednesday) Issued at 323 AM CST THU FEB 18 2016 A quasi zonal pattern sets up for Friday and through the weekend with the bulk of energy passing to the north of the forecast area. Models continue to show low level moisture advection into east central KS for Saturday and Saturday night as a subtle piece of energy passes across the state. Both the NAM and GFS suggest there will be little to no instability however and model progs of 850 winds remain rather light for this time of year. Nevertheless there has been a persistent signal from the models for the possibility for showers and thunderstorms so have maintained a small chance POP for Saturday afternoon and Saturday evening. By Sunday morning, a cold front is expected to push south of the forecast area with dry air moving in. This should bring and end to the precip changes as well as cooler temps for Sunday. Temps for Friday and Saturday should remain well above normal. Forecast soundings show the boundary layer mixing fairly deeply on Friday but also bring in some cooler temps at 850 MB such that adiabatic mixing would only support highs in the mid and upper 60s. Because of this have shaved a degree or two off the highs from the prev forecast. The airmass stays pretty similar for Saturday. The one wild car is possible low clouds moving into eastern KS and limiting insolation. For now have continued with highs in the mid and upper 60s for Saturday. For next week, the models are suggesting the pattern becomes more amplified with a return to northwest flow for the central plains. However there are differences in how the pattern sets up and where week waves within the flow move. Its plausible that there could be some light precip with these passing waves, similar to what we experienced earlier this week. However low confidence in the small scale features preclude a mention of precip chances at this time. With the return of northwest flow, models bring the occasional ridge of high pressure through the plains. This is expected to keep temps cooler with highs in the 50s and lows around freezing next week. && .AVIATION...(For the 06Z TAFS through 06Z Thursday Night) Issued at 1130 PM CST WED FEB 17 2016 VFR conditions are expected through the period. The first concern will be low level wind shear through 14Z, then south to southwest winds of 17 kts to 22 kts sustained with gusts to 32 kts expected through 01Z then decreasing slightly through the end of the period. && .FIRE WEATHER... Issued at 323 AM CST THU FEB 18 2016 High resolution guidance is still struggling on dewpoints during the afternoon as it appears to still overestimate the amount of moisture advection from the southwest while underestimating the depth of vertical mixing in regards to the drier air aloft. Forecast was collaborated to side closer to the RAP and HRRR solutions which represent an even compromise of RH values falling to the low and middle 30 percent range for most of the area. Most uncertain area is across north central Kansas where stronger mixing aloft and from the dryline may help realize RH values dropping sharply towards the upper teen to lower 20 percent range during the late afternoon. Regardless of the RH values being borderline, winds sustained at 25 to 35 mph with gusts in upwards of 45 to 50 mph will easily promote uncontrolled fire growth given the critical fuels reported. Therefore have upgraded the watch to a Red Flag Warning in effect at 11 AM until 6 PM this evening for the entire area. Uncertainty increases for this evening as RH values rise. Winds remain strong however so any fire that forms during the afternoon will remain uncontrollable overnight. Have maintained the watch overnight for the next shift to review. For Friday, dry air is still expected to overspread the forecast area with min RH values falling to around 20 percent during the afternoon. However models show the pressure gradient relaxing pretty quickly in the morning Friday and wind speeds are forecast to be quite a bit lighter. There remains the possibility to see some gusts around 20 MPH especially across northern KS where the gradient will be slower to relax. But the overall trend in the models has been for weaker winds. Will keep the fire weather watch in tact for now because of the dry air, but there is a real possibility that conditions will not make it to red flag on Friday. && .TOP Watches/Warnings/Advisories... Red Flag Warning from 11 AM this morning to 7 PM CST this evening for KSZ008>012-020>024-026-034>040-054>056-058-059. Fire Weather Watch from this evening through Friday afternoon for KSZ008>012-020>024-026-034>040-054>056-058-059. Wind Advisory from 11 AM this morning to 7 PM CST this evening for KSZ021>024-026-034>040-054>056-058-059. && $$ SHORT TERM...Bowen LONG TERM...Wolters AVIATION...53 FIRE WEATHER...Bowen/Wolters
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1113 PM EST WED FEB 17 2016 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE REGION OVERNIGHT WITH MUCH COLDER AIR FOLLOWING FOR THURSDAY AS HIGH PRESSURE SLOWLY BUILDS TOWARD THE AREA. THE HIGH WILL MOVE EAST ON FRIDAY. A CLIPPER TYPE SYSTEM WILL BRING SOME LIGHT SNOW TO THE REGION ON SATURDAY. && .NEAR TERM /THROUGH THURSDAY NIGHT/... 11 PM UPDATE: ADJUSTED THE HRLY TEMPS/DEWPOINTS TO ACCOUNT FOR THE LATEST CONDITIONS. CLOUDS MOVING IN FROM THE W AS THE COLD FRONT SLIDES SE. TEMPERATURES ARE FALLING OFF BUT STILL SLOWER THAN PREVIOUSLY FORECAST. THE LATEST ADJLAV DOING THE BEST W/TEMPS SHOWING THEM TO DROP OFF AFTER 3 AM W/CAA ARRIVING. IR SATELLITE IMAGERY SHOWED GOOD ENHANCEMENT ACROSS THE CENTRAL AND WESTERN AREAS. THE LATEST REGIONAL RADAR ALONG W/THE MRMS SHOWED SOME ECHOES SHOWING UP ACROSS SOUTHERN QUEBEC. THE HRRR AND RAP SHOW BEST SUPPORT FOR SNOW SHOWERS ACROSS THE WEST-CENTRAL AREAS OVERNIGHT. STAYED CLOSE TO THE DAYCREW W/THE 30% POPS ATTM BUT A SHIFT FURTHER S TOWARD PISCATAQUIS COUNTY AND MT. KATAHDIN. PREVIOUS DISCUSSION... AS FAR AS SNOW ACCUMULATIONS GO, HAVE GENERALLY KEPT ACCUMULATIONS LESS THAN AN INCH IN ANY SNOW SHOWERS TONIGHT. BUT AS IS TYPICALLY THE CASE WITH THESE SITUATIONS, SOME LOCATIONS UNDER ANY HEAVIER BANDS COULD PICK UP A QUICK INCH OR TWO BY EARLY THURSDAY MORNING. OTHERWISE EXPECT MAINLY CLOUDY SKIES OVERNIGHT WITH THE COLDEST READINGS ACROSS FAR NORTHERN MAINE AND THE ST JOHN VALLEY WHERE TEMPERATURES WILL FALL INTO THE SINGLE DIGITS ABOVE ZERO BY MORNING BUT ONLY INTO THE LOW TO MID 20S ACROSS INTERIOR DOWN EAST MAINE AND COASTAL LOCATIONS. THURSDAY WILL BE A COLDER DAY IN THE WAKE OF THE FRONT WITH HIGH TEMPERATURES ABOUT 5 TO 10 DEGREES COOLER THAN TODAY. WE COULD STILL SEE SOME LINGERING SNOW STREAMERS FIRST THING THURSDAY MORNING UNTIL THE PASSAGE OF AN UPPER TROF DURING THURSDAY AFTERNOON. EXPECT PARTLY TO MOSTLY CLOUDY SKIES TO GIVE WAY TO INCREASING SUNSHINE BY LATE THURSDAY AFTERNOON. HIGH TEMPERATURES THURSDAY WILL BE IN THE UPPER TEENS TO NEAR 20 NORTH AND LOW TO MID TEENS DOWN EAST AND THE COAST. THURSDAY NIGHT WILL SEE HIGH PRESSURE BUILDING EAST TOWARD THE AREA WITH MAINLY CLEAR SKIES EXPECTED. LOOKS LIKE THE POTENTIAL IS THERE FOR SOME RADIATIONAL COOLING, ESPECIALLY ACROSS WESTERN AND INTERIOR DOWN EAST AREAS. AS SUCH, HAVE GONE A LITTLE COLDER THAN GUIDANCE FOR LOW TEMPERATURES THURSDAY NIGHT WHERE FEEL TEMPERATURES MAY DROP WELL BELOW ZERO, ESPECIALLY ACROSS THE COLDER VALLEY LOCALES OF THE NORTH AND WEST. AGAIN, THIS IS ALL DEPENDENT ON WHETHER OF NOT WE DECOUPLE AND WINDS CAN DROP OFF QUICK ENOUGH. EXPECT LOWS 5 TO 10 BELOW ACROSS NORTHWEST AREAS TO 5 TO 10 ABOVE DOWN EAST && .SHORT TERM /FRIDAY THROUGH SATURDAY/... AFTER A CHILLY START FRI MORN WITH THE PASSAGE OF SFC HI PRES TO OUR E...TEMPS SHOULD RECOVER TO SLIGHTLY ABV NORMAL AFTN HIGHS. CLDS INCREASE W TO E ACROSS THE AREA FRI EVE AND OVRNGT...WITH LGT SN MOVG INTO THE FA LATE AS S/WV ENERGY ALF AND LLVL WARM ADVCN INCREASE. IN FACT...WITH THE SFC LOW FROM ONT PROV TRACKING WELL TO OUR N...MOST MODELS SHOW ENOUGH LLVL WARM ADVCN FOR LGT SNFL SAT MORN MIXING WITH EVEN CHGNG TO RN BY SAT AFTN...SPCLY DOWNEAST AS FCST 925MB TEMPS RISE TO OR JUST ABV ZERO C...SO MOST SN ACCUMULATION WITH THIS LITTLE EVENT WILL BE PRIOR TO 1 PM SAT. MILD TEMPS WILL CONTINUE INTO SAT EVE FOR MIXED LGT RN/SN OR RN/SN SHWRS N AND ALL LGT RN/LGT RN SHWRS CNTRL AND DOWNEAST THEN ENDING OVRNGT SAT. TOTAL EVENT SNFL FOR LATE FRI NGT INTO ERLY SAT EVE WE SHOW MATCHES CLOSE TO THE 50TH PERCENTILE OF SNOW PROB TOTALS FROM WPC ENSEMBLES. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... SLIGHTLY COLDER AIR SHOULD ARRIVE FOR SUN BEHIND THE LOW EXITING THRU THE NRN CAN MARITIMES SAT NGT. A SIG DIFFERENCE EXITS BETWEEN THE 12Z OPNL GFS AND THE OTHER LONGER TERM OPNL MODELS FOR LATE SUN NGT INTO MON...WITH THE GFS SHOWING A SIG S/WV MOVG TOWARD AND ACROSS THE FA FROM THE GREAT LKS WITH OVRRNG ATLC MOISTURE. OTHER MODELS ARE MUCH WEAKER AND FLATTER/FURTHER S WITH THE S/WV FEATURE ALF...WITH LITTLE OR NO ORGANIZED STRATIFORM PRECIP AS FAR N AS OUR FA...BUT RATHER SCT SN SHWRS OR FLURRIES. WITH THE 12Z GFS ENSM SHOWING A SOLUTION MORE IN LN WITH THE 12Z CANGEM...WHICH KEEPS ANY LGT STRATIFORM PRECIP S OF OUR FA...WE KEPT POPS FOR SN SHWRS IN THE LOW CHC RANGE N TO HIGHER CHC DOWNEAST FOR NOW. OTHERWISE...FAIR AND SEASONALLY COLDER CONDITIONS FOLLOW MON`S WEAK S/WV FOR MON NGT AND TUE AS SEMI ARCTIC AIR MOVES EWRD INTO THE FA. LONGER RANGE MODELS ARE IN BETTER AGREEMENT WITH REGARD TO THE EVOLUTION OF A SIG COASTAL MID ATLC LOW PRES SYSTEM FOR THE MID TO LATE WEEK...WITH THE TYPICAL GFS EARLY TMG AND LATER ECMWF TMG BIASES. TAKING A BLEND OF THE MODELS BRINGS THE LEADING EDGE OF PRECIP TO DOWNEAST AREAS LATE TUE NGT...SLOWLY SPREADING NWRD INTO THE REST OF THE FA WED INTO WED NGT. BOTH MODELS SHOW STRONG MID LVL WARMING WELL ALF...IN THE 750 TO 850 MB LAYER...TO BEGIN OCCURRING N OF THE DEVELOPING LOW BY WED NGT...POTENTIALLY BRINGING A FAIRLY WIDE BAND OF SLEET TO THE REGION...MORE TYPICAL OF MARCH WNTR STMS IN THIS AREA. STILL WAY TO EARLY TO NAIL DOWN SPECIFICS ABOUT WHO AND WHEN WILL HAVE WHAT PRECIP TYPES GIVEN UNCERTAINTIES OF STM TRACK AND INTENSITY...BUT WE DID GENERATE PRECIP FROM THICKNESS USING A BLEND OF 12Z OPNL GFS/ECMWF...SHOWING THE POTENTIAL OF SLEET AND PERHAPS A NARROW BAND OF FZRA BY WED NGT. FOR NOW...WE GO WITH MAX POPS OF HI CHC N AND CNTRL AND LOW LIKELY FOR DOWNEAST AREAS BY WED EVE...ABOUT AS HIGH AS WE ASSIGN WITH AN EVENT AT DAY 7 TO 7.5. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... NEAR TERM: SKY CONDITION, VFR VS MVFR IS A POTENTIAL CHALLENGE TONIGHT. FCST SOUNDING ARE HINTING AT THE POTENTIAL FOR AN MVFR CLOUD LAYER BENEATH A SHALLOW INVERSION LATER TONIGHT, MAINLY KFVE/KCAR/KPQI/KHUL NORTH. ANOTHER CHALLENGE WILL BE THE POTENTIAL FOR SCATTERED SNOW SHOWERS. AVIATORS SHOULD EXPECT AT LEAST THE POTENTIAL FOR MVFR CIGS OR VSBY IN ANY SNOW SHOWERS, MAINLY NRN TAF SITES. THESE CONDITIONS MAY PERSIST INTO THURSDAY MORNING FOLLOWED BY A RETURN TO VFR THURSDAY AFTERNOON. SHORT TERM: ALL SITES INITIALLY VFR FRI INTO FRI EVE...THEN CLGS AND VSBYS LOWERING TO MVFR AND IFR IN LGT FALLING SN LATE FRI NGT INTO SAT MORN AND THEN MIXED PRECIP SAT AFTN INTO SAT EVE. CONDITIONS IMPROVE TO MVFR CLGS N AND VFR DOWNEAST LATE SAT NGT CONTG INTO SUN EVE...THEN BECOME MVFR ALL SITES MON WITH CLGS AND OCNL VSBYS WITH SN SHWRS. && .MARINE... NEAR TERM: LONG PERIOD WAVES (CURRENTLY 11S) WERE AFFECTING THE COASTAL WATERS AND WE ARE EXPECTING WAVES TO ONLY SLOWLY SUBSIDE OVERNIGHT AND INTO THU. WILL EXTEND THE SMALL CRAFT ADVISORY FOR SEAS THROUGH THE DAY THURSDAY FOR THE OUTER MOST WATERS. WITH SEAS ACROSS THE INTRACOASTAL TO ONLY BE AROUND 5 FEET WITH LONG PERIOD SWELL WILL DROP SCA FOR THAT ZONE. SHORT TO LONG TERM: NO DEFINABLE GALE OR GREATER HDLN POTENTIAL FOR OUR WATERS AT LEAST THRU TUE...WITH THE BEST POTENTIAL OF SCA WVS AND SEAS SAT INTO SAT EVE WITH A MDT SRLY WIND FETCH. OTHERWISE WINDS AND SEAS WILL BE AT OR BELOW MIN SCA THRESHOLDS. KEPT CLOSE TO WW3 WV HTS FOR FCST WV HTS FOR THESE PTNS OF THE MARINE FCST. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST THURSDAY FOR ANZ050-051. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
322 AM CST THU FEB 18 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 322 AM CST THU FEB 18 2016 TODAY AND TONIGHT...A BLEND OF THE 4 GUIDANCE DATA SET PLUS BIAS CORRECTION SUGGESTS HIGHS IN THE LOWER 70S TODAY. IT LOOKS LIKE HIGH CLOUDS WILL BE IN AND OUT OF THE FCST AREA SO THE WARMEST NUMBERS PROBABLY WOULD NOT VERIFY. THE BAROCLINIC LEAF STRETCHING ACROSS THE WRN U.S. WILL MOVE OVER THE FCST AREA TODAY. THE LATEST MODELS SHOW HIGH WINDS MORE LIKELY TONIGHT. THE RAP MODEL INDICATES AN ASTONISHING 3 HR PRESSURE RISE OF 13 MB NEAR RAWLINS WY AT 01Z TONIGHT. THIS COUPLED WITH A PV1.5 ANOMALY AND H850 WINDS RISING TO 60-70KT PRODUCES A MODERATE OR HIGHER POTENTIAL FOR HIGH WINDS ACROSS WRN AND NCNTL NEB. THE GFS20 CLOCKS THE COLD FRONT MOVING EAST AT 60 MPH. THE NAM FCSTS WIND GUSTS APPROACHING 70 MPH IN SOME LOCATIONS. THIS WOULD BE THE MAX WE WOULD EXPECT ASSUMING A MIXED LAYER FORMS ALONG THE COLD FRONT. PEAK WIND GUSTS WOULD LAST 1 TO 2 HOURS AS THE FRONT RACES THROUGH THE FCST AREA BETWEEN 03Z AND 09Z. THE PV1.5 ANOMALY SUGGESTS INTERSTATE 80 AND NCNTL NEB ALONG AND EAST OF HIGHWAY 83 WOULD BE MOST FAVORED FOR HIGH WINDS. THE NAM WIND GUSTS INDICATE ALL ZONES. THE GFS SOUNDINGS FOR NORTH PLATTE SHOW A MIXED LAYER EXTENDING TO 550MB AT 03Z JUST AHEAD OF THE COLD FRONT WHICH COLLAPSES TO 780MB BEHIND THE FRONT. THE 500M AGL TEMPERATURE FALLS FROM 73F AT 03Z TO 47F AT 06Z WITH 55 TO 65 KT WINDS AT THIS LEVEL...OFF THE CHARTS. A HIGH WIND WATCH IS IN PLACE FOR ALL ZONES TONIGHT. THE RAP AND HRRR MODELS COULD PERHAPS CULL SOME COUNTIES FROM THE WATCH LATER TODAY. THE MODEL CONSENSUS SUGGEST SPRINKLES OR ISOLATED SHOWERS TONIGHT...MAINLY ALONG AND NORTH OF HIGHWAY 20. THIS WOULD EASILY MIX THE STRONG WINDS ALOFT DOWN TO THE SFC IN THESE AREAS. THUS THE CONVECTION MAY WORK FOR HIGH WINDS WHERE THE PV1.5 ANOMALY IS ABSENT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 322 AM CST THU FEB 18 2016 MID RANGE...FRIDAY AND SATURDAY...MAIN FORECAST CHALLENGES ARE TEMPERATURES AND WIND. GUSTY WINDS CONTINUE IN THE WAKE OF THE STRONG PACIFIC FRONT AND PV ANOMALY WHILE DOWNSLOPE WINDS AND WARM 850HPA TEMPS CONTRIBUTE TO WELL ABOVE NORMAL HIGHS. GFS AND NAM KEEP LOW/MID LEVEL WINDS AOA 40 KTS THROUGH 18Z FRIDAY...PRIMARILY ACROSS THE NORTHERN HALF OF THE FORECAST AREA. WIDESPREAD SUBSIDENCE WILL RESULT IN FAIR CONDITIONS AND A WELL MIXED BOUNDARY LAYER. FORECAST SOUNDINGS SHOW MIXING TO 700HPA AT KLBF AND KVTN FRIDAY AFTERNOON WITH NEARLY UNIDIRECTIONAL WINDS. EDGED MAX TEMPS CLOSER TO THE MAV AND ECS GUIDANCE...WHICH BOTH SHOW UPPER 60S FOR MOST OF WESTERN NEBRASKA. A WEAK FRONT DROPS SOUTH ACROSS THE REGION SATURDAY...RESULTING IN SLIGHTLY COOLER MAX TEMPS NORTH BUT ABOUT THE SAME SOUTH. SOUNDINGS STILL INDICATE GOOD MIXING SATURDAY...BUT WIND WILL NOT BE A BIG AN ISSUE AS THE MID AND UPPER LEVEL SUPPORT WILL HAVE MOVED EAST. LONG RANGE...SUNDAY TO WEDNESDAY...A COUPLE WAVES TRAVERSE THE AREA SUNDAY AND TUESDAY WHILE 500HPA FLOW TRANSITIONS FROM QUASI ZONAL TO NORTHWEST. A SURFACE HIGH BUILDING OVER THE NORTHERN PLAINS AND 850HPA CAA LEADING TO TEMPS NEAR 0C AT 18Z SUNDAY WILL TAKE HIGHS MUCH CLOSER TO NORMAL. FRONTOGENESIS LOOKS IMPRESSIVE EARLY SUNDAY...BUT MOISTURE AND LIFT ARE LACKING. SOUTHERLY FLOW RETURNS MONDAY WITH LITTLE IN TERMS OF TEMPERATURE RECOVERY. THE GFS AND EURO SHOW BETTER MOISTURE AND MARGINAL LIFT FOR THE SYSTEM ON TUESDAY...HOWEVER DISCREPANCIES REMAIN WITH THE TIMING OF THE BEST FORCING. EXTENDED PROCEDURE INTRODUCED SCHC POPS...BUT DECIDED TO KEEP DRY WITH THIS FORECAST PACKAGE DUE TO LOW CONFIDENCE. MORE DOWNSLOPING WINDS WITH A 850HPA RIDGE AXIS MOVING THROUGH THE SANDHILLS WEDNESDAY...PUSHING HIGHS INTO THE LOWER 50S AGAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1145 PM CST WED FEB 17 2016 FOR BOTH THE KLBF AND KVTN TERMINALS...EXPECT SCATTERED TO BROKEN CIGS OF 20000 FT AGL OVER THE NEXT 24 HOURS. WINDS WILL BE FROM THE SOUTH OVERNIGHT AT 10 KTS...SHIFTING TO THE SOUTHWEST AT 10 TO 20 KTS THURSDAY AFTERNOON. WINDS WILL TEMPORARILY SHIFT TO THE SOUTH AT 10 KTS THURSDAY EVENING WITH AN ABRUPT SHIFT TO THE WEST AFTER 03Z FRIDAY. WIND SPEEDS WILL QUICKLY INCREASE TO 15 TO 25 KTS WITH GUSTS APPROACHING 35 KTS. && .LBF WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM THIS EVENING THROUGH LATE TONIGHT FOR NEZ004>010-022>029-035>038-056>059-069>071-094. && $$ SHORT TERM...CDC LONG TERM...SNIVELY AVIATION...BUTTLER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1224 AM CST THU FEB 18 2016 .UPDATE... ISSUED AT 1223 AM CST THU FEB 18 2016 INCREASED SOUTHEASTERLY WINDS IN THE JAMES VALLEY FOR THE EARLY MORNING HOURS...AS WINDS AT THE SURFACE WERE GUSTING OVER 20 KNOTS. MODELS INDICATE STRENGTHENING H925 AND H850 WINDS OVER THE EASTERN DAKOTAS WHICH IS TRANSLATING TO THE SURFACE. OTHERWISE LOW CLOUDS AND AREAS OF FOG REMAINS ACROSS THE REGION FOR THE OVERNIGHT HOURS. VISIBILITIES HAVE BEEN VARYING QUITE A BIT ACROSS WESTERN AND CENTRAL NORTH DAKOTA...RANGING FROM 1/2 MILE TO BETTER THAN 6 AT TIMES. UPDATE ISSUED AT 917 PM CST WED FEB 17 2016 FOR LATE EVENING UPDATE HAVE INCREASED FOG COVERAGE WITH VARIOUS LOCATIONS REPORTING REDUCED VISIBILITIES OVER THE AREA. HAVE ALSO EXPANDED CLOUD COVER THROUGHOUT THE AREA AS MOIST SOUTHEAST FLOW CONTINUES TO KEEP CLOUDS IN PLACE. UPDATE ISSUED AT 624 PM CST WED FEB 17 2016 PREVIOUS FORECAST WAS IN GOOD SHAPE WITH PATCHY FOG OVER THE AREA. LOWEST VISIBILITIES REMAIN ALONG THE WESTERN EDGE OF RETREATING LOW CLOUD COVER STRETCHING FROM DICKINSON TO TIOGA. EXPECT THIS TREND TO CONTINUE WITH LOW CLOUDS DOING A VERY SLOW RETRACTION TOWARDS THE EAST THIS EVENING. UPDATES HAVE BEEN SENT. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 300 PM CST WED FEB 17 2016 PATCHY FOG AND POSSIBLE LIGHT FREEZING DRIZZLE IS IN THE FORECAST TONIGHT AND EARLY THURSDAY AHEAD OF A MILD THURSDAY AFTERNOON. LOWER ATMOSPHERIC CONDITIONS TONIGHT INTO THURSDAY MORNING WILL BE VERY FAVORABLE FOR STRATUS MAINTENANCE AND DEVELOPMENT THANKS TO A STOUT AND STRENGTHENING INVERSION ALOFT WITH MILD...SOUTHERLY LOW- LEVEL FLOW THAT WILL ACCESS DEWPOINTS WHICH AVERAGE 30 F UPSTREAM AS OF MID AFTERNOON. PATCHY FOG IS ALSO INCLUDED IN THE FORECAST GIVEN EXPECTED BUILD-DOWN OF THE STRATUS...BUT FORECAST SOUNDINGS SUGGEST THE NEAR-GROUND LAYER MAY BE TOO TURBULENT FOR DENSE FOG DEVELOPMENT OWING TO SOUTHERLY WINDS OVER 15 KT WITHIN 1000 FT OF THE SURFACE. THE 15 TO 19 UTC HRRR AND ESRL-HRRR ITERATIONS ON THE OTHER HAND SIMULATE SOME DENSE FOG DEVELOPMENT...SO WE WILL WATCH THIS SCENARIO CLOSELY EVEN THOUGH WE BELIEVE THE PROBABILITY OF ANYTHING MORE THAN TRANSIENT SUB-3/4SM VISIBILITIES IS RATHER LOW. WE CHOSE TO KEEP A SLIGHT CHANCE OF LIGHT FREEZING DRIZZLE IN THE FORECAST OVER PARTS OF CENTRAL ND TONIGHT INTO THURSDAY MORNING IN RESPECT TO THE DEEPENING MOIST LAYER BENEATH THE INVERSION SEEN ON MODEL-DERIVED FORECAST SOUNDINGS. THE 12 UTC GFS DEEPENS THE MOIST LAYER SUFFICIENTLY TO GENERATE LIGHT QPF IN ITS SIMULATION ACROSS NORTH CENTRAL AND EAST CENTRAL ND BETWEEN 06 AND 12 UTC...WHICH IS SUGGESTIVE OF A VERY LOW PROBABILITY OF BONAFIDE LIGHT FREEZING RAIN NEAR THE PEAK OF THE WARM-ADVECTIVE REGIME. HOWEVER...THAT IS AN OUTLIER SOLUTION...AND FORECAST OMEGA FIELDS FROM BOTH THE GFS AND NAM SUGGEST VERTICAL MOTION IN THE STRATUS LAYER MAY BE WEAK. WE THUS ARE NOT PARTICULARLY IMPRESSED WITH FREEZING DRIZZLE RISK EVEN THOUGH IT WAS HIGH ENOUGH TO STILL INCLUDE IN THE FORECAST. BY THURSDAY AFTERNOON...A VERY MILD AIR MASS WILL BE IN PLACE IN ADVANCE OF A STRONG 500-MB SHORTWAVE TROUGH EXPECTED TO BE MOVING INTO THE NORTHERN ROCKIES. LOW CLOUDS MAY HOLD BACK HEATING WHERE THEY REMAIN THICK ENOUGH THROUGH THE DAY...BUT WITH TEMPERATURES AT 850 MB OF +13 TO +15 C IN SOUTHWEST ND...HIGHS WILL LIKELY HIT 60 F IN PLACES LIKE BOWMAN...WITH WIDESPREAD 40S AND 50S F SOUTH AND WEST OF THE MISSOURI RIVER. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 PM CST WED FEB 17 2016 THE LONG TERM APPEARS ACTIVE WITH SEVERAL CHANCES FOR RAIN...FREEZING RAIN AND SNOW. TEMPERATURES WILL REMAIN NEAR THE MAGIC FREEZING THRESHOLD AND THEREFORE A MIX OF RAIN...FREEZING RAIN AND SNOW APPEARS POSSIBLE. LIGHT FREEZING RAIN AND SNOW APPEAR THE MORE FAVORABLE PRECIPITATION TYPE DURING THE MORNING AND EVENING HOURS OF FRIDAY...SATURDAY AND SUNDAY...CHANGING OVER TO MAINLY RAIN DURING THE AFTERNOONS. ONLY LIGHT AMOUNTS OF MOISTURE ARE EXPECTED ANY GIVEN DAY...GENERALLY LESS THAN A TENTH OF AN INCH. A CLIPPER WILL MOVE THROUGH THE NORTHERN PLAINS FRIDAY. THIS CLIPPER MAY BRING SOME HIGH WINDS TO THE REGION. MIXING WEST WINDS...STEEP LAPSE RATES AND MODERATE PRESSURE RISES COULD PRODUCE WINDS AROUND 50 MPH. IF TRENDS CONTINUE TO INDICATE THE PRESENCE OF THESE FEATURES THEN A WIND ADVISORY APPEARS LIKELY...WITH A HIGH WIND WARNING POSSIBLE. DECIDED TO WITHHOLD ISSUING A HIGH WIND WATCH TODAY AS THERE IS SOME UNCERTAINTY WITH RESPECT TO THE TIMING OF THE PRESSURE RISES AND MIXING DOWN OF MID-LEVEL WINDS AND HIGHER WINDS AREN`T EXPECTED FOR ANOTHER 48 HOURS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1223 AM CST THU FEB 18 2016 WIDESPREAD LIFR CIGS WILL REMAIN OVER THE AREA THROUGH TONIGHT INTO EARLY THURSDAY WITH GRADUAL IMPROVEMENT EXPECTED THURSDAY MORNING. BY THURSDAY MID-DAY VFR CONDITIONS EXPECTED OVER SOUTHWEST NORTH DAKOTA WHILE MOST REMAINING AREAS WILL CONTINUE TO EXPERIENCE IFR TO MVFR CIGS. AROUND/AFT 00Z CIGS IMPROVE TO VFR AT KISN. KBIS TO IMPROVE TO VFR FOR A SHORT TIME AROUND 00Z-03Z THEN BACK DOWN TO MVFR/IFR. LATE IN THE TAF PERIOD A CLIPPER SYSTEM OUT OF ALBERTA APPROACHES THE NORTHERN PLAINS AND STRONG WINDS IN THE WARM SECTOR BEGIN ALOFT AT KISN/KDIK/KBIS...AND ADDED MENTION OF WIND SHEAR ALOFT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JV SHORT TERM...CJS LONG TERM...AJ AVIATION...JV
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1102 PM CST WED FEB 17 2016 .AVIATION.../06Z TAF CYCLE/ LOW CIGS ARE ALREADY BEGINNING TO DEVELOP ACROSS SOUTH TEXAS AND THIS AREA WILL SHIFT NORTH AND EXPAND ACROSS ALL TERMINALS OVERNIGHT. THE CURRENT VFR CONDITIONS WILL FALL TO IFR AND LIFR PAST 08Z THROUGH 15- 16Z ACROSS THE REGION. SREF AND HRRR OUTPUT SUGGESTS A BUILD DOWN OF THE LOWER CIGS TO PATCHY AND AREAS OF FOG THAT WILL REDUCE VISIBILITIES TO 2-4 SM. LOCATIONS ACROSS THE ESCARPMENT BETWEEN KSAT AND KDRT COULD EXPERIENCE VLIFR AT TIMES BUT WILL BE LOW PROBABILITY AT THE ACTUAL TERMINAL SITES OF KSAT/KSSF. A GRADUAL IMPROVEMENT WILL OCCUR THROUGH MID MORNING HOURS THURSDAY BUT LOW CLOUDS WILL HOLD ON LONGER THEN PREVIOUS DAYS. ALL SITES SHOULD MIX OUT TO VFR BY EARLY AFTERNOON. SURFACE WINDS WILL ALSO BECOME GUSTY FROM THE SOUTH AT 15-20 KT WITH SOME GUSTS HAS HIGH AS 30 KT GIVEN A TIGHTER PRESSURE GRADIENT AND STRONG VERTICAL MIXING. && .PREV DISCUSSION... /ISSUED 1025 PM CST WED FEB 17 2016/ EVENING UPDATE... MADE SOME ADJUSTMENTS TO THE WX GRID TO HIGHLIGHT AREAS OF FOG ALONG THE ESCARPMENT. MOISTURE ADVECTION SHOULD CONTINUE TO BE STRONG BUT WINDS MAY STAY HIGH ENOUGH TO PROHIBIT MUCH DENSE FOG. THAT BEING SAID...HIGHEST CONFIDENCE OF AREAS VS PATCHY WILL BE ALONG AND NORTH OF THE ESCARPMENT PERIPHERY NORTH OF SAN ANTONIO. OTHERWISE...NO OTHER FORECAST UPDATES WERE NEEDED. PREV DISCUSSION... /ISSUED 304 PM CST WED FEB 17 2016/ SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... INCREASING SOUTHERLY FLOW IN THE LOW-LEVELS WILL RESULT IN MOIST AIR ADVECTION ACROSS SOUTH CENTRAL TEXAS TONIGHT. THE INCREASED MOISTURE WILL RESULT IN LOW CLOUD DEVELOPMENT ALONG WITH ABOVE NORMAL OVERNIGHT LOWS ACROSS ALL AREAS. WE ALSO EXPECT PATCHY FOG TO DEVELOP ACROSS MOST OF SOUTH CENTRAL TEXAS LATE TONIGHT INTO MID-MORNING THURSDAY. SOUTHERLY WINDS AND MIXING WILL DISSIPATE THE FOG AND LOW CLOUDS ON THURSDAY...LEAVING MOSTLY SUNNY SKIES AND ANOTHER DAY OF ABOVE NORMAL HIGH TEMPERATURES THURSDAY AFTERNOON. LONG TERM (FRIDAY THROUGH WEDNESDAY)... SOUTHERLY FLOW IN THE LOW-LEVELS ALONG WITH WESTERLY FLOW ALOFT WILL REMAIN DOMINANT ACROSS THE REGION THROUGH THE WEEKEND INTO EARLY NEXT WEEK. THE MEDIUM RANGE MODELS DO SHOW SOME FAST MOVING MID-LEVEL SHORTWAVES MOVING THROUGH TEXAS ON SUNDAY. RAIN CHANCES WILL REMAIN LOW IN THIS PATTERN AND WE/LL ONLY MENTION A 20% CHANCE FOR PRECIPITATION AT THIS TIME. WE DID INCLUDE A MENTION OF THUNDERSTORMS ACROSS THE SOUTHERN EDWARDS PLATEAU AND PORTIONS OF THE HILL COUNTRY AS THE GFS SHOWS A COLD FRONT MOVING IN DURING THE LATE AFTERNOON OR EARLY EVENING HOURS. THE COLD FRONT APPEARS TO SLOW IT/S SOUTHWARD PROGRESS ON MONDAY AS THE FLOW ALOFT TRANSITIONS TO NORTHWESTERLY. WITH A BOUNDARY IN THE AREA AND AN INCREASINGLY ACTIVE NORTHWEST FLOW ALOFT...WE/LL MENTION A 20-50% CHANCE OF RAIN FOR THE REGION SUNDAY NIGHT AND MONDAY. A REINFORCING SURGE OF HIGH PRESSURE WILL MOVE SOUTHWARD INTO THE SOUTHERN U.S. PLAINS MONDAY NIGHT. THIS WILL USHER THE COLD FRONT SOUTHWARD ON TUESDAY AND KEEP ANY RAIN CHANCES LIMITED TO AREAS GENERALLY ALONG AND EAST OF HIGHWAY 281. RAINFALL AMOUNTS APPEAR FAIRLY LOW AT THIS TIME AND WILL KEEP AMOUNTS AT OR BELOW ONE QUARTER INCH. ON TUESDAY...GUSTY NORTH WINDS SPREAD ACROSS ALL AREAS BEHIND THE COLD FRONT. TEMPERATURES WILL DROP CLOSER TO CLIMATOLOGICAL NORMALS ON TUESDAY AND WEDNESDAY AS DRY WEATHER RETURNS TO THE REGION. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 75 53 78 60 81 / 0 0 - - - AUSTIN BERGSTROM INTL AIRPORT 75 47 79 57 79 / 0 0 - - 10 NEW BRAUNFELS MUNI AIRPORT 76 50 80 56 80 / 0 0 - - 10 BURNET MUNI AIRPORT 75 49 77 56 79 / 0 0 0 0 0 DEL RIO INTL AIRPORT 82 56 80 56 82 / 0 0 - 0 - GEORGETOWN MUNI AIRPORT 75 50 77 58 79 / 0 0 - - - HONDO MUNI AIRPORT 79 51 81 53 84 / 0 - - - 10 SAN MARCOS MUNI AIRPORT 76 49 79 56 80 / 0 0 - - 10 LA GRANGE - FAYETTE REGIONAL 75 50 80 60 79 / 0 0 - - 10 SAN ANTONIO INTL AIRPORT 77 53 79 57 81 / 0 0 - - 10 STINSON MUNI AIRPORT 79 52 81 56 82 / 0 0 - - 10 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...ALLEN SYNOPTIC/GRIDS...TB3 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1144 PM EST WED FEB 17 2016 .SYNOPSIS... A WEAK COLD FRONT WILL CROSS INTO THE MOUNTAINS OVERNIGHT BEFORE DISSIPATING BY THURSDAY MORNING. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND WILL COVER MUCH OF THE EASTERN UNITED STATES ON THURSDAY. A LOW PRESSURE SYSTEM IN THE UPPER MISSISSIPPI VALLEY FRIDAY WILL MOVE EAST ACROSS THE GREAT LAKES ON SATURDAY. && .NEAR TERM /THROUGH THURSDAY/... AS OF 840 PM EST WEDNESDAY... SOUNDINGS SHOW RATHER DEEP LOW LEVEL MOISTURE OVER THE MOUNTAINS THIS EVENING WITH A MOIST LAYER UNDER THE INVERSION ALOFT BETWEEN THE SURFACE AND 8H. THIS WITHIN A LAYER OF DECENT NW FLOW AHEAD OF A WEAK SURFACE COLD FRONT IN THE OHIO VALLEY THAT WILL BASICALLY DISSIPATE CROSSING THE REGION OVERNIGHT. AHEAD OF THE BOUNDARY HAVE SEEN JUST ENOUGH LIFT UNDER THE UPSLOPE FLOW TO PRODUCE A FEW SMALL BANDS OF FLURRIES AND SNOW SHOWERS OVER THE WEST BUT QUITE LIGHT/SPOTTY AT THIS POINT. THUS HAVE INCLUDED SOME ADDED LOW POPS OUT TOWARD THE NEW RIVER VALLEY AND THE HIGH COUNTRY OF NW NORTH CAROLINA UNTIL AROUND MIDNIGHT PER THE EARLIER 4KM NAM OUTPUT. EXPECT MORE DRYING TO DEVELOP FROM THE NORTH LATER TONIGHT AS HIGH PRESSURE BUILDS JUST NORTH OF THE REGION AND ADDED SUBSIDENCE SLOWLY ACTS TO DIMINISH THE LOW LEVEL MOISTURE. HOWEVER BEFORE THIS OCCURS MAY SEE SOME LOW CLOUDS SPILL OUT EAST OF THE BLUE RIDGE GIVEN THE DECENT NW JET WHILE STILL EXPECT THE LOW DECK TO PERSIST FAR WEST A BIT LONGER. THEREFORE BUMPED UP CLOUDS SOME MAINLY OVER THE NEXT FEW HOURS FROM THE BLUE RIDGE WESTWARD. LINGERING CLOUDS AND MIXING MAY ALSO ACT TO HOLD TEMPS UP AS THE LATEST LAMP QUITE A BIT WARMER PROVIDED CLOUDS REMAIN IN PLACE. SINCE THINK MORE BREAKS MAY DEVELOP WONT RAISE LOWS MORE THAN A CATEGORY ESPCLY GIVEN GRADUAL FILTERING IN OF WEAK COLD ADVECTION OVERNIGHT. PREVIOUS DISCUSSION AS OF 200 PM EST WEDNESDAY... A SHORTWAVE LOCATED IN KENTUCKY AROUND 18Z WILL ROTATE EAST AROUND THE BASE OF THE UPPER TROUGH THIS AFTERNOON INTO TONIGHT. THE UPPER TROF AXIS IS FORECAST TO PIVOT NORTHEAST TONIGHT...ALLOWING SOME RIDGING AND RISING 500 MB HEIGHTS. SFC COLD FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON WILL WEAKEN AND DISSIPATE OVER THE MID ATLANTIC REGION BY THURSDAY MORNING. THE HIRESW-ARW-E...RNK- WRFARW...GFS AND NAM SHOWED ISOLATED SCATTERED SHOWERS ACROSS THE WESTERN MOUNTAINS. THE ECMWF...RAP AND HRRR ARE LESS IMPRESSED FOR ACTIVITY. FOR TONIGHT...WILL MAINTAIN SCATTERED SNOW SHOWERS IN THE WESTERN MOUNTAINS. ANY SNOW ACCUMULATIONS WILL BE LIGHT AND LESS THAN AN INCH. THE BEST CHANCE OF SNOW WILL OCCUR ALONG THE WESTERN SLOPES OF GREENBRIER COUNTY OF WEST VIRGINIA. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MID TEENS IN THE NORTHWEST MOUNTAINS TO THE MID 20S IN THE SOUTHEAST. ANY LINGERING MOUNTAIN SNOW SHOWERS AND SNOW FLURRIES SHOULD BE GONE THURSDAY MORNING...AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. SOME LINGERING STRATOCUMULUS CLOUDS MAY STILL PERSIST UNTIL THE AFTERNOON WEST OF THE BLUE RIDGE...WHEN THE HIGH BUILDS OVERHEAD. EAST OF THE BLUE RIDGE...LOOK FOR PLENTY OF SUNSHINE. HIGH TEMPERATURES WILL VARY FROM THE LOWER 30S IN THE NORTHWEST MOUNTAINS TO THE UPPER 40S IN THE PIEDMONT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... AS OF 245 PM EST WEDNESDAY A CLASSIC WEDGE WILL TAKE RESIDENCE OVER THE EAST COAST THURSDAY NIGHT INTO FRIDAY. THE MID ATLANTIC PORTION OF THE WEDGE WILL DRIFT OUT TO SEA AS A NORTHERN STREAM DISTURBANCE TRACKS EAST OF THE GREAT LAKES FRIDAY NIGHT. THIS DISTURBANCE WILL PUSH A WEAK COLD FRONT OVER THE AREA EARLY SATURDAY. THE SOUTHERN PORTION OF THIS WEDGE WILL REMAIN OVER THE SOUTHEASTERN US WHILE BLOCKING THE GULF. THE FRONT COMING ACROSS EARLY SATURDAY WILL BE MOISTURE STARVED WITH A FEW LIGHT RAIN SHOWERS HITTING THE WESTERN SLOPES AND ONLY AN INCREASE IN CLOUDS ELSEWHERE. ZONAL FLOW BECOMES ESTABLISHED BY SATURDAY AFTERNOON AND WILL REMAIN THROUGH THE WEEKEND. BEING AHEAD OF THE FRONT FRIDAY...TEMPERATURES WILL WARM AT OR ABOVE NORMAL WITH READINGS IN THE M/U 40S WEST TO L50S EAST. DESPITE THE PASSING OF A WEAK FRONT SATURDAY MORNING...TEMPERATURES WILL MODERATE WARMER THAN NORMAL WITH WIDESPREAD 50S ACROSS THE AREA TO THE LOWER 60S IN THE PIEDMONT. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 115 PM EST WEDNESDAY THE NORTHERN AND SOUTHERN STREAMS WILL REMAIN SEPARATED THROUGH THE WEEKEND. DISTURBANCES IN THE NORTHERN STREAM WILL TRACK EAST FROM THE GREAT LAKES TO NORTHEASTERN US. ACROSS THE SOUTH...A STALLED BOUNDARY WILL KEEP RAIN FROM EASTERN TEXAS TO SOUTH CAROLINA. FOR THE IMMEDIATE AREA...A WEAK MOISTURE STARVED FRONT WILL PASS OVER THE REGION FRIDAY NIGHT INTO SATURDAY MORNING. SOME LIGHT PRECIPITATION MAY FALL ALONG WESTERN SLOPES...DRY ELSEWHERE. WITH ZONAL FLOW OVER THE WEEKEND...TEMPERATURES WILL WARM INTO THE 50S AND 60S. ON MONDAY...THE NORTHERN STREAM WILL SEND AN UPPER LEVEL TROUGH ACROSS THE PLAINS. WAVES OF LOW PRESSURE WILL FORM AND TRACK ALONG THE STALLED BOUNDARY ACROSS THE SOUTHERN STATES. MONDAY NIGHT INTO TUESDAY...MODEL GUIDANCE IS NOT IN AGREEMENT WITH TIMING OF THE NEXT LOW PRESSURE SYSTEM BRINGING POTENTIAL FOR RAIN AND SNOW TO THE AREA. A HIGH PRESSURE WEDGES DOWN ALONG THE EASTERN SLOPES OF THE BLUE RIDGE MONDAY EVENING. THE STRENGTH OF THE WEDGE WILL DEPEND ON WHAT TYPE OF PRECIP TO EXPECT OVERNIGHT. THE WEDGE MOVES OUT QUICKLY TUESDAY MORNING RETURNING TO RAIN BY THE AFTERNOON. THE UPPER LEVEL TROUGH DEEPENS THROUGH THE TENNESSEE VALLEY IT BECOMES NEGATIVE-TILTED WITH CONVECTIVE SHOWERS TRACKING EAST OF THE BLUE RIDGE TO THE COASTAL PIEDMONT. TEMPERATURES WILL REMAIN WELL ABOVE NORMAL MONDAY AND TUESDAY FOR ALL PRECIPITATION TO STAY LIQUID. THE FRONT WILL PASS TO THE EAST TUESDAY NIGHT...WITH UPSLOPE SNOW SHOWERS LIKELY INTO WEDNESDAY MORNING...ALL PRECIP SHOULD EXIT THE REGION BY WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS IN. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1135 PM EST WEDNESDAY... WEAK PUSH OF LOW LEVEL COLD ADVECTION ON NW WINDS WILL CONTINUE TO CREATE PERIODS OF MVFR TO IFR CIGS OVER THE WEST OVERNIGHT WITH SOME OF THIS CANOPY SPILLING OUT TO THE BLUE RIDGE BUT MAINLY IN VFR FASHION. COULD SEE SOME IMPROVEMENT AT TIMES AS CLOUD BASES SCATTER OUT AFTER MIDNIGHT BUT OVERALL SUB- VFR FROM KBCB WESTWARD FOR MUCH OF THE OVERNIGHT. ANY SNOW SHOWER BANDS ALSO LOOK QUITE ISOLATED BUT SINCE CONTINUE TO FOCUS AROUND KBLF ADDED IN A PERIOD OF SUB-VFR VSBYS OVER THE NEXT FEW HOURS BEFORE BETTER DRYING OCCURS LATE. OTHERWISE WILL LEAVE OUT ANY PRECIP ELSEWHERE OVERNIGHT. ON THURSDAY...HIGH PRESSURE WILL MOVE OVER AND TO THE NORTH OF THE REGION ALLOWING DRYING FROM ALOFT TO GRADUALLY MIX OUT RESIDUAL LOWER CIGS OVER THE MOUNTAINS. HOWEVER MAY TAKE UNTIL LATE IN THE DAY TO BRING KBLF/KLWB BACK TO VFR...WITH SPOTS LIKE KBCB IMPROVING BY MIDDAY. ELSEWHERE EXPECTING MAINLY VFR UNDER SOME SHEARED HIGH LEVELS CLOUDS. SHOULD SEE ALL SITES REMAIN VFR THURSDAY NIGHT WITH AGAIN JUST SOME HIGH CLOUDS AROUND. EXTENDED DISCUSSION... VFR CONDITIONS PREVAIL AT ALL SITES THROUGH FRIDAY AS HIGH PRESSURE REPOSITIONS TO OFF THE CAROLINAS ALLOWING RETURN SW FLOW TO DEVELOP. ANOTHER LOW PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY. IT COULD SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS ON FRIDAY NIGHT AND SATURDAY AS A WEAK SURFACE TROUGH PASSES THROUGH. A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY AND SLIDE THROUGH THE REGION LATER SUNDAY NIGHT INTO MONDAY BEFORE SETTLING JUST SOUTH OF THE AREA. THIS COULD BRING A PERIOD OF SUB-VFR INCLUDING A FEW SHOWERS FROM LATE SUNDAY INTO SUNDAY NIGHT...AND OVER SOUTHERN SECTIONS ON MONDAY. OTHERWISE MAINLY VFR GIVEN FUTURE UNCERTAINTY WITH TIMING OF THESE FEATURES. && .HYDROLOGY... AS OF 815 PM EST WEDNESDAY... STAGES ARE FALLING ON THE UPPER DAN RIVER FROM DANVILLE UPSTREAM BUT CONTINUING TO SLOWLY RISE DOWNSTREAM. HOWEVER PACES ALONG THE DAN IS EXPECTED TO CREST IN THE NEXT FEW HOURS BEFORE FALLING BELOW FLOOD STAGE BY EARLY THURSDAY MORNING. LEVELS WILL CONTINUE TO SLIDE UPWARD AT SOUTH BOSTON WITH A CREST DURING THURSDAY MORNING. EXPECT MINOR FLOODING OF LOWLAND AREAS. STAGES ALSO CONTINUE TO CLIMB ALONG THE LOWER ROANOKE RIVER AT RANDOLPH WHICH WILL MAINLY IMPACT LOWLANDS AND SEVERAL ROADS NEAR THE RIVER. RANDOLPH IS EXPECTED TO CREST OVERNIGHT BUT REMAIN ABOVE FLOOD STAGE UNTIL LATE THURSDAY. THUS FLOOD WARNINGS CONTINUE FOR THE ROANOKE RIVER AT RANDOLPH AFFECTING CHARLOTTE AND HALIFAX COUNTIES...AS WELL AS THE DAN RIVER AT PACES AND SOUTH BOSTON AFFECTING HALIFAX COUNTY. CHECK THE LATEST WBCFLSRNK FOR ADDED DETAILS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK NEAR TERM...JH/KK SHORT TERM...RCS LONG TERM...RCS AVIATION...JH/KK HYDROLOGY...KK/PC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
321 AM CST THU FEB 18 2016 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 321 AM CST THU FEB 18 2016 SURFACE MAP SHOWS DEEP LOW PRESSURE MOVING EASTWARD OUT OF MONTANA WITH A WARM FRONT ARCHING THROUGH SD INTO EASTERN NE AND WESTERN MO. IR SATELLITE SHOWS A BAND OF ALTOSTRATUS IN ADVANCE OF THIS WARM FRONT COVERING ALL OF THE FORECAST AREA. COMBINATION OF CLOUD COVER AND LIGHT SOUTHEAST WINDFLOW KEEPING TEMPERATURES IN CHECK IN THE UPPER TEENS TO THE MIDDLE 20S AS OF 2 AM. SOUTHERLY FLOW PICKS UP TODAY INTO TONIGHT AS THE AREA OF LOW PRESSURE AND WARM FRONT APPROACH THE REGION. RAP BUFKIT SHOWS MOSTLY MID/HIGH CLOUD OVER THE AREA TODAY WITH STRATUS HOLDING OFF TO THE WEST...HOWEVER AS THE WARM FRONT APPROACHES THIS EVENING/OVERNIGHT... LOWEST 1.5KM OF COLUMN QUICKLY SATURATES LEADING TO WIDESPREAD STRATUS. LIFT/TURNING THROUGH THIS STRATUS WILL LEAD TO AREAS OF DRIZZLE WITH THE POSSIBILITY OF A LITTLE FREEZING DRIZZLE NORTH OF HIGHWAY 10 IN NORTH CENTRAL WI. ONLY LOOKS LIKE A 3-4 HOUR WINDOW AS TEMPERATURES WILL BE WARMING THROUGH THE NIGHT. LOOKS LIKE SHOWERS TAKE OVER WITH EVEN A CHANCE OF A RUMBLE OR TWO OF THUNDER IN THE 3-6AM TIME FRAME WITH 850MB MOISTURE TRANSPORT MAXIMIZING AND AS MID-LEVEL PV-ANOMALY/SURFACE LOW/COLD FRONT APPROACH FROM MN. WILL HAVE TO WATCH HIGH TEMPERATURES TODAY IN FILTERED SUNSHINE. HAVE MID 30S-LOWER 40S GOING NOW...BUT COULD END UP BEING A FEW DEGREES WARMER IF SUN FILTERS THROUGH ENOUGH. FRIDAY WILL SEE MAINLY MORNING TO EARLY AFTERNOON SHOWER CHANCES AS THE LOW AND COLD FRONT SWING THROUGH. THERE WILL ALSO BE A SLIGHT CHANCE OF A FEW MORNING THUNDERSTORMS AS WELL. OTHERWISE...LOOKS LIKE WE BREAK OUT IN ALMOST FULL SUNSHINE BY AFTERNOON WITH A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING LOW/COLD FRONT. THIS SHOULD ALLOW FOR DECENT MIXING. THIS LOOKS TO TAP SOME FAIRLY STRONG WINDS WITH NAM/GFS BUFKIT SHOWING 40-50KT ONLY 0.5KM AGL. RIGHT NOW...LOOKING LIKE SUSTAINED WESTERLY WINDS OF 20-30MPH WITH GUSTS 35 TO 40 MPH...POSSIBLY CLOSING IN ON 50 MPH IN THE MORE WIND PRONE AREAS OF NORTHEAST IA/SOUTHEAST MN AND HIGHER TERRAIN/BLUFF TOPS ALONG THE MISSISSIPPI RIVER. LOOKING LIKELY WE WILL EVENTUALLY NEED A WIND ADVISORY HEADLINE BASED ON THIS. OTHERWISE...A COLD FRONT PASSED THROUGH...MIXING OF PLAINS DOWNSLOPED AIR BEHIND THIS SYSTEM SHOULD PUSH HIGHS WELL INTO THE 40S WITH A FEW LOWER 50S ACROSS NORTHEAST IA INTO SOUTHWEST WI. STRATUS CLOUDS FILL BACK IN FROM NORTHWEST TO SOUTHEAST INTO THE AREA FRIDAY NIGHT BUT REMAINING RELATIVELY MILD WITH LOWS ONLY FALLING INTO THE LOWER/MIDDLE 30S. .LONG TERM...(SATURDAY THROUGH WEDESDAY) ISSUED AT 321 AM CST THU FEB 18 2016 HIGH ZONAL FLOW ACROSS THE NORTHERN CONUS FOR SATURDAY INTO SUNDAY. THIS USHERS IN A WEAK MID-LEVEL TROUGH WITH A SMALL CHANCE OF SNOW LATE SATURDAY NIGHT AND MOSTLY RAIN CHANCES SUNDAY AS TEMPERATURES WARM INTO THE MIDDLE 30S TO LOWER 40S. MONDAY THROUGH WEDNESDAY LOOKING DRY AND A BIT COOLER/BACK TO NEAR NORMAL AS UPPER LEVEL TROUGHING CARVES INTO THE CENTRAL CONUS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1100 PM CST WED FEB 17 2016 BAND OF MID LEVEL CLOUDS ASSOCIATED WITH MID LEVEL WARM AIR ADVECTION WORKING NORTHEAST...WITH A THIN BAND OF IFR/MVFR CLOUDS JUST BEHIND THAT. LOW LEVEL RAP/NAM RH FIELDS CAPTURE THIS REASONABLY WELL...WITH SATELLITE TRENDS BRINGING THE LOWER CIGS INTO KRST NEAR 08Z AND KLSE TOWARD 10Z. THE BAND IS RELATIVELY THIN...AND MESO MODELS SUGGEST IT MAY ONLY STICK AROUND FOR A FEW HOURS. A RETURN TO VFR CONDITIONS WOULD RESULT BEFORE INCREASING LOW SATURATION ON THE NOSE OF LOW LEVEL MOISTURE TRANSPORT RETURNS IFR/MVFR BY MID AFTERNOON. NOT COMPLETELY SOLD ON THE BREAK TO VFR...BUT BELIEVE THE TRENDS SUPPORT IT. WITH THE INCREASING DEPTH TO THE LOW SATURATION...STRONG ISENTROPIC LIFT/THERMODYNAMICS WOULD SAY DRIZZLE AND/OR RAIN BECOMES LIKELY FOR THU EVENING. LIGHT WINDS WILL INCREASE OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS...BECOMING RELATIVELY STRONG/GUSTY FOR THU. DIRECTION SHOULD HOLD SOUTHEASTERLY INTO THU NIGHT. && .HYDROLOGY... ISSUED AT 321 AM CST THU FEB 18 2016 WITH CLIMBING TEMPERATURES INTO THE WEEKEND...SIGNIFICANT SNOW MELT WILL TAKE PLACE...MELTING A 1-2 INCH WATER EQUIVALENT SNOWPACK WHICH WILL ENTER THE RIVERS. A FEW MODELS SHOWING A COMPLETE MELT OF THIS SNOWPACK. AS A RESULT...EXPECT RIVER RISES AND THE POSSIBILITY OF ICE BREAKUP ON STREAMS/RIVERS. A FEW ICE JAMS COULD RESULT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION....RIECK HYDROLOGY...DAS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
859 AM MST THU FEB 18 2016 .SYNOPSIS... A TURN TOWARDS SOMEWHAT COOLER TEMPERATURES AND AN INCREASE IN CLOUDINESS IS ON TAP TODAY AND FRIDAY...AS A UPPER LEVEL LOW PRESSURE SYSTEM MOVES OFF TO OUR NORTH ACROSS THE GREAT BASIN. HOWEVER...TEMPERATURES ARE AGAIN EXPECTED TO WARM WELL BACK UP INTO THE 80S FROM THIS WEEKEND ONWARD INTO AT LEAST THE MIDDLE PART OF NEXT WEEK...AS STRONG HIGH PRESSURE REBUILDS OVER THE DESERT SOUTHWEST. && .DISCUSSION... COLD FRONTAL BOUNDARY IS MAKING SOUTHEASTWARD PROGRESS ACROSS SOUTHERN CALIFORNIA WITH WEAK FORCING AHEAD OF THE FRONT PROVIDING EXTENSIVE MID LEVEL CLOUDINESS AND A THIN BAND OF VERY LIGHT SHOWERS OR SPRINKLES. FOR THE REST OF TODAY AM EXPECTING THE COLD FRONT TO PUSH THROUGH ARIZONA WITH SKIES BECOMING MOSTLY CLOUDY OVER MUCH OF OUR AREA THROUGH THIS AFTERNOON. THE BAND OF LIGHT SHOWERS AND SPRINKLES WILL MOVE THROUGH THE PHOENIX AREA LATE THIS MORNING AND THEN PUSH SOUTHWARD INTO THIS AFTERNOON. NOT EXPECTING ANY MEASURABLE RAINFALL OUT OF THIS BAND...BUT IT MAY BE ENOUGH TO WET THE GROUND IN VERY LOCALIZED AREAS...MORE LIKELY OVER THE HIGHER TERRAIN. HAVE UPDATED THE NEAR TERM FORECAST TO REFLECT THIS...MAINLY COVERING AREAS WITH SPRINKLES THROUGH MID AFTERNOON. HAVE ALSO KNOCKED A DEGREE OR TWO OFF OUR HIGHS TODAY ACROSS SOUTH-CENTRAL ARIZONA AS THE CLOUDINESS DURING THE MID PART OF THE DAY AND COOLING ALOFT SHOULD KEEP MANY AREAS FROM BREACHING THE 80 DEGREE MARK. ADDITIONAL MID LEVEL MOISTURE IS FORECAST TO SPREAD NORTHEASTWARD ACROSS SOUTHERN ARIZONA LATE TONIGHT INTO FRIDAY WHICH WILL AGAIN PROVIDE FOR QUITE A BIT OF CLOUDINESS AND CONTINUED COOLER DAYTIME HIGHS. && .PREVIOUS DISCUSSION... TODAY THROUGH FRIDAY... AFTER A VERY WARM DAY ON WEDNESDAY WHICH SAW THE EARLIEST 90 DEGREE HIGH ON RECORD AT PHOENIX SKY HARBOR...A TURN TOWARDS SOMEWHAT COOLER TEMPERATURES IS STILL EXPECTED TODAY AND FRIDAY AS THE VERY STRONG UPPER LEVEL RIDGE THAT BROUGHT US THE VERY WARM WEATHER IS FLATTENED BY AN UPPER TROF THAT IS NOW MOVING INLAND INTO THE WESTERN GREAT BASIN. ALTHOUGH THE SFC COLD FRONT CAN BE SEEN ON LATEST SATELLITE/RADAR IMAGERY MOVING EASTWARD ACROSS SE CA THIS MORNING...VIRTUALLY ALL OF THE RAINFALL ASSOCIATED WITH THE FRONT IS PASSING OFF TO THE NORTH OF OUR CWA WITH JUST A FEW SPRINKLES PERHAPS REACHING THE GROUND OVER THE HIGHER ELEVATIONS OF JOSHUA TREE NATIONAL PARK. THE LATEST HRRR IS SHOWING VIRTUALLY NO RAINFALL WILL MAKE IT TO THE LOWER ELEVATIONS OF SE CA AS THE SFC FRONT CONTINUES TO WEAKEN AND MOST OF THE DYNAMICS/MOISTURE SHIFT OFF TO THE NORTH WITH THE MAIN TROF. THE MAIN IMPACTS FOR MOST OF OUR CWA WILL BR A INCREASE IN MID AND HIGH LEVEL CLOUDINESS AND SLIGHT COOLING ALOFT (500MB TEMPS FALLING FROM AROUND -8C TO 12C)...WHICH IS EXPECTED TO RESULT IN ABOUT A 8-10F COOLING OF OUR HIGH TEMPERATURES FROM WEDNESDAY/S VALUES TAKING LOWER DESERT HIGHS DOWN INTO THE LOWER 80S ON BOTH DAYS. ON FRIDAY...THE GFS...NAM...AND SREF ARE ALL SHOWING A PLUME OF SUBTROPICAL MOISTURE MOVING INTO SW AND SOUTH-CENTRAL AZ AS A VERY WEAK SHORTWAVE THAT IS EMBEDDED IN BROAD MID LEVEL SWLY FLOW MOVES INTO THE AREA. ALTHOUGH PWATS DO BRIEFLY SURGE UP INTO THE 0.70-0.90 INCH RANGE AS THE SHORTWAVE PASSES THROUGH...ONLY VIRGA OR LIGHT SPRINKLES ARE EXPECTED SINCE MOST MOISTURE IS EXPECTED TO REMAIN AOA 600MB WITH VIRTUALLY ALL OF THE NCEP SREF PLUMES SHOWING NO MEASURABLE PRECIP AT PHOENIX. SATURDAY THOUGH NEXT THURSDAY... THERE CONTINUES TO BE VERY GOOD CONSENSUS BETWEEN THE MAIN GLOBAL MODEL SUITES AND MANY OF THEIR RESPECTIVE MEMBERS ON THE FORECAST FOR THIS PERIOD. THEY ALL ARE BUILDING VERY STRONG RIDGING NORTHWARD ALONG THE WEST COAST AND INTO THE DESERT SOUTHWEST AS A DEEP LONGWAVE TROF DROPS SOUTHWARD INTO THE CENTRAL/EASTERN CONUS. THE RESULT IS A DRY FORECAST FOR THE ENTIRE PERIOD WITH LOWER DESERT HIGHS ONCE AGAIN RISING UP INTO THE MIDDLE/UPPER 80S UNDER MOSTLY SUNNY SKIES. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... MID AND HIGH CLOUDS WILL INCREASE THROUGH THE DAY...THOUGH CIGS WILL REMAIN AOA 12K FT LIMITING ANY AVIATION IMPACT. STEADY EAST SFC WINDS WILL RAPIDLY SWITCH TO A WESTERLY COMPONENT FASTER THAN USUAL BY EARLY AFTERNOON BEHIND A WEAK FRONTAL BOUNDARY. HOWEVER...THE PRESSURE GRADIENT WILL BE RATHER WEAK ALLOWING FAIR CONFIDENCE THAT THE EASTERLY WINDS WILL RESUME BY MID EVENING. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... TIMING WIND SHIFTS AND OCCASIONAL STRONGER GUSTS WILL THE MAIN AVIATION FORECAST CHALLENGE TODAY. A WEAK FRONTAL BOUNDARY NEAR TERMINAL LOCATIONS THIS MORNING SHOULD SHIFT EAST ALLOWING A PERIOD OF GUSTY W/SW WINDS TO DEVELOP BY LATE MORNING/EARLY AFTERNOON...THOUGH SPEEDS SHOULD REMAIN BELOW 25KT. NOCTURNAL DECOUPLING SHOULD OCCUR QUICKLY AFTER SUNSET WITH A NWLY COMPONENT AND WIND SPEED UNDER 10KT. A FEW-SCT CLOUDS NEAR THE 6K FT LEVEL MAY PASS WITH THE FRONT...BUT OTHERWISE CIGS WILL GENERALLY BY ABOVE 12K FT. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... TEMPERATURES WILL WARM STEADILY THROUGH THE WEEKEND WITH NEAR RECORD SETTING WARMTH REGAINING A FOOTHOLD ON THE REGION EARLY NEXT WEEK. VERY DRY CONDITIONS WILL ALSO PREDOMINATE WITH MINIMUM HUMIDITY LEVELS IN THE TEENS LOCALLY TOUCHING SINGLE DIGIT VALUES BY EARLY NEXT WEEK. WINDS WILL GENERALLY REMAIN WEAK WITH THE TYPICAL DIURNAL UPSLOPE/DRAINAGE COMPONENT...HOWEVER PERIODS OF GUSTY NORTHERLY WINDS MAY BE COMMON THROUGHOUT THE LOWER COLORADO RIVER VALLEY SUNDAY AND MONDAY YIELDING A LOCALLY ELEVATED FIRE DANGER. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...KUHLMAN PREVIOUS DISCUSSION...PERCHA AVIATION...MO FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
410 AM MST THU FEB 18 2016 ...UPDATED AVIATION AND FIRE WEATHER... .SYNOPSIS... A TURN TOWARDS SOMEWHAT COOLER TEMPERATURES AND AN INCREASE IN CLOUDINESS IS ON TAP TODAY AND FRIDAY...AS A UPPER LEVEL LOW PRESSURE SYSTEM MOVES OFF TO OUR NORTH ACROSS THE GREAT BASIN. HOWEVER...TEMPERATURES ARE AGAIN EXPECTED TO WARM WELL BACK UP INTO THE 80S FROM THIS WEEKEND ONWARD INTO AT LEAST THE MIDDLE PART OF NEXT WEEK...AS STRONG HIGH PRESSURE REBUILDS OVER THE DESERT SOUTHWEST. && .DISCUSSION... TODAY THROUGH FRIDAY... AFTER A VERY WARM DAY ON WEDNESDAY WHICH SAW THE EARLIEST 90 DEGREE HIGH ON RECORD AT PHOENIX SKY HARBOR...A TURN TOWARDS SOMEWHAT COOLER TEMPERATURES IS STILL EXPECTED TODAY AND FRIDAY AS THE VERY STRONG UPPER LEVEL RIDGE THAT BROUGHT US THE VERY WARM WEATHER IS FLATTENED BY AN UPPER TROF THAT IS NOW MOVING INLAND INTO THE WESTERN GREAT BASIN. ALTHOUGH THE SFC COLD FRONT CAN BE SEEN ON LATEST SATELLITE/RADAR IMAGERY MOVING EASTWARD ACROSS SE CA THIS MORNING...VIRTUALLY ALL OF THE RAINFALL ASSOCIATED WITH THE FRONT IS PASSING OFF TO THE NORTH OF OUR CWA WITH JUST A FEW SPRINKLES PERHAPS REACHING THE GROUND OVER THE HIGHER ELEVATIONS OF JOSHUA TREE NATIONAL PARK. THE LATEST HRRR IS SHOWING VIRTUALLY NO RAINFALL WILL MAKE IT TO THE LOWER ELEVATIONS OF SE CA AS THE SFC FRONT CONTINUES TO WEAKEN AND MOST OF THE DYNAMICS/MOISTURE SHIFT OFF TO THE NORTH WITH THE MAIN TROF. THE MAIN IMPACTS FOR MOST OF OUR CWA WILL BR A INCREASE IN MID AND HIGH LEVEL CLOUDINESS AND SLIGHT COOLING ALOFT (500MB TEMPS FALLING FROM AROUND -8C TO 12C)...WHICH IS EXPECTED TO RESULT IN ABOUT A 8-10F COOLING OF OUR HIGH TEMPERATURES FROM WEDNESDAY/S VALUES TAKING LOWER DESERT HIGHS DOWN INTO THE LOWER 80S ON BOTH DAYS. ON FRIDAY...THE GFS...NAM...AND SREF ARE ALL SHOWING A PLUME OF SUBTROPICAL MOISTURE MOVING INTO SW AND SOUTH-CENTRAL AZ AS A VERY WEAK SHORTWAVE THAT IS EMBEDDED IN BROAD MID LEVEL SWLY FLOW MOVES INTO THE AREA. ALTHOUGH PWATS DO BRIEFLY SURGE UP INTO THE 0.70-0.90 INCH RANGE AS THE SHORTWAVE PASSES THROUGH...ONLY VIRGA OR LIGHT SPRINKLES ARE EXPECTED SINCE MOST MOISTURE IS EXPECTED TO REMAIN AOA 600MB WITH VIRTUALLY ALL OF THE NCEP SREF PLUMES SHOWING NO MEASURABLE PRECIP AT PHOENIX. SATURDAY THOUGH NEXT THURSDAY... THERE CONTINUES TO BE VERY GOOD CONSENSUS BETWEEN THE MAIN GLOBAL MODEL SUITES AND MANY OF THEIR RESPECTIVE MEMBERS ON THE FORECAST FOR THIS PERIOD. THEY ALL ARE BUILDING VERY STRONG RIDGING NORTHWARD ALONG THE WEST COAST AND INTO THE DESERT SOUTHWEST AS A DEEP LONGWAVE TROF DROPS SOUTHWARD INTO THE CENTRAL/EASTERN CONUS. THE RESULT IS A DRY FORECAST FOR THE ENTIRE PERIOD WITH LOWER DESERT HIGHS ONCE AGAIN RISING UP INTO THE MIDDLE/UPPER 80S UNDER MOSTLY SUNNY SKIES. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... MID AND HIGH CLOUDS WILL INCREASE THROUGH THE DAY...THOUGH CIGS WILL REMAIN AOA 12K FT LIMITING ANY AVIATION IMPACT. STEADY EAST SFC WINDS WILL RAPIDLY SWITCH TO A WESTERLY COMPONENT FASTER THAN USUAL BY EARLY AFTERNOON BEHIND A WEAK FRONTAL BOUNDARY. HOWEVER...THE PRESSURE GRADIENT WILL BE RATHER WEAK ALLOWING FAIR CONFIDENCE THAT THE EASTERLY WINDS WILL RESUME BY MID EVENING. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... TIMING WIND SHIFTS AND OCCASIONAL STRONGER GUSTS WILL THE MAIN AVIATION FORECAST CHALLENGE TODAY. A WEAK FRONTAL BOUNDARY NEAR TERMINAL LOCATIONS THIS MORNING SHOULD SHIFT EAST ALLOWING A PERIOD OF GUSTY W/SW WINDS TO DEVELOP BY LATE MORNING/EARLY AFTERNOON...THOUGH SPEEDS SHOULD REMAIN BELOW 25KT. NOCTURNAL DECOUPLING SHOULD OCCUR QUICKLY AFTER SUNSET WITH A NWLY COMPONENT AND WIND SPEED UNDER 10KT. A FEW-SCT CLOUDS NEAR THE 6K FT LEVEL MAY PASS WITH THE FRONT...BUT OTHERWISE CIGS WILL GENERALLY BY ABOVE 12K FT. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... TEMPERATURES WILL WARM STEADILY THROUGH THE WEEKEND WITH NEAR RECORD SETTING WARMTH REGAINING A FOOTHOLD ON THE REGION EARLY NEXT WEEK. VERY DRY CONDITIONS WILL ALSO PREDOMINATE WITH MINIMUM HUMIDITY LEVELS IN THE TEENS LOCALLY TOUCHING SINGLE DIGIT VALUES BY EARLY NEXT WEEK. WINDS WILL GENERALLY REMAIN WEAK WITH THE TYPICAL DIURNAL UPSLOPE/DRAINAGE COMPONENT...HOWEVER PERIODS OF GUSTY NORTHERLY WINDS MAY BE COMMON THROUGHOUT THE LOWER COLORADO RIVER VALLEY SUNDAY AND MONDAY YIELDING A LOCALLY ELEVATED FIRE DANGER. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA AVIATION...MO FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1020 AM EST THU FEB 18 2016 .UPDATE (TODAY-FRIDAY)... 15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFIED UPPER LEVEL PATTERN IN PLACE. LOOKING FROM WEST TO EAST WE FIND A POTENT UPPER LEVEL LOW/TROUGH ARRIVING ALONG THE PACIFIC COAST...WITH A STRONG UPPER JET SPREADING OVER THE INTERMOUNTAIN WEST. THIS STRONG JET FURTHER DOWNSTREAM BUILDS A LARGE RIDGE THROUGH THE CENTRAL PORTION OF THE CONUS BEFORE DIVING BACK TO THE SOUTH INTO LONGWAVE TROUGHING NOW EXITING INTO THE WESTERN ATLANTIC. CLOSER TO HOME...THE FLORIDA PENINSULA RESIDES ON THE BACKSIDE OF THIS DEPARTING LONGWAVE TROUGH WITH DEEP LAYER SUBSIDENCE IN PLACE AND SLOWLY BUILDING HEIGHTS ALOFT. THESE BUILDING HEIGHTS WILL ENSURE OUR SENSIBLE WEATHER REMAINS DRY THROUGH THE UPCOMING WEEKEND. 18/12Z KTBW SOUNDING PROFILE SHOWS A VERY DRY COLUMN OVER OUR HEADS WITH A DEFINED SUBSIDENCE INVERSION LOCATED AROUND 850MB. WITH THE VERY DRY AIR IN PLACE...AND LITTLE IN THE WAY OF FORCING FOR LIFT...OUR SKIES ARE GENERALLY CLEAR THIS MORNING...WITH ABUNDANT SUNSHINE FOR ALL. AT THE SURFACE...THE FLORIDA PENINSULA IS UNDER CONTROL OF A RIDGE OF HIGH PRESSURE THAT EXPANDS ALL THE WAY SOUTH FROM A CENTER OVER THE OHIO VALLEY/NE STATES. THIS RIDGE IS PROVIDING THE REGION WITH A GENERAL NORTHEASTERLY FLOW PATTERN. THE FORECAST AREA IS SEEING A PLEASANT WINTER DAY UNDERWAY. WITH THE ABUNDANT SUNSHINE AND GOOD DIURNAL MIXING...TEMPERATURES ARE RESPONDING AND QUICKLY RISING THROUGH THE 60S. AFTERNOON HIGH TEMPERATURES SHOULD REACH MAXIMUM VALUES IN THE MIDDLE 60S TO AROUND 70 NORTH TO THE LOWER/MID 70S ACROSS THE SOUTHERN ZONES. FAIR...DRY...AND SEASONABLE WEATHER WILL CONTINUE FOR TONIGHT INTO FRIDAY. THE DRY AIR AND CLEAR SKIES IN PLACE WILL HELP TEMPERATURES COOL DOWN OVERNIGHT. BY SUNRISE LOOKING FOR LOWS IN THE LOWER/MID 40S FAR NORTH...TO THE UPPER 40S/LOWER 50S THROUGH THE I-4 CORRIDOR...AND MIDDLE 50S DOWN THROUGH FORT MYERS...AND ALSO SOUTHERN PINELLAS COUNTY. TEMPERATURES ON FRIDAY WILL RESPOND QUICKLY ONCE AGAIN AFTER THE COOL START...REACHING THE LOWER TO MIDDLE 70S ALMOST REGION-WIDE UNDER MOSTLY SUNNY SKIES. ...AND MORE OF THE SAME FOR THE UPCOMING WEEKEND. && .AVIATION... VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WINDS SHIFTING FROM NORTHEAST TODAY TO EASTERLY FRIDAY. && .MARINE... HIGH PRESSURE CENTERED OVER THE OHIO VALLEY WILL DRIFT SOUTHEAST TOWARD TEH CAROLINAS BY FRIDAY...AND INTO THE WESTERN ATLANTIC THIS WEEKEND. THIS RIDGE WILL REMAIN IN CONTROL OF THE FORECAST WATERS WITH WINDS SHIFTING FROM NORTHEAST TO EAST THROUGH THE PERIOD. WINDS WILL DROP BELOW CAUTIONARY LEVELS TODAY...BUT QUICKLY RAMP BACK UP TO CAUTIONARY LEVELS THIS EVENING AND THROUGH THE OVERNIGHT. THERE IS SOME POTENTIAL THAT THE WINDS MAY REACH A PERIOD OF ADVISORY LEVEL WINDS TONIGHT AS WELL. WINDS WILL ONCE AGAIN SUBSIDE DURING THE DAY FRIDAY...AND THEN GENERALLY REMAIN BELOW HEADLINE CRITERIA THROUGH THE WEEKEND AS THE RIDGE CENTER MOVES CLOSER TO THE REGION. && .PRELIMINARY POINT TEMPS/POPS... TPA 72 53 74 55 / 0 0 0 0 FMY 76 55 76 55 / 0 0 10 10 GIF 72 52 74 53 / 0 0 0 0 SRQ 75 53 75 54 / 0 0 0 0 BKV 72 47 75 47 / 0 0 0 0 SPG 71 57 72 57 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/AVIATION/MARINE...MROCZKA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
427 AM MST THU FEB 18 2016 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 322 AM MST THU FEB 18 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW RIDGE IN PLACE ACROSS THE CENTRAL US...WITH A STRONG UPPER LOW OFF THE PACIFIC NW COAST. 130-145 KT 300MB JET WAS OBSERVED OVER CALIFORNIA ON 00Z RAOBS AND ON WV THIS CAN BE SEE AS STRONG AREA OF CLEARING NOSING INTO DIFFLUENT REGION BETWEEN RIDING AND UPPER LOW. DEEP SW FLOW IS IN PLACE ACROSS THE CENTRAL ROCKIES WITH PLUME OF THICK HIGH CLOUD COVER STREAMING INTO THE PLAINS. AT THE SURFACE...LOW PRESSURE IS IN PLACE OVER EASTERN COLORADO WITH DRY LINE APPROXIMATELY FROM LAMAR COLORADO SOUTH. FOCUS ON THIS FORECAST PERIOD IS ON FIRE WEATHER TODAY AND A POSSIBLE HIGH WIND EVENT TONIGHT. SEE FIRE WEATHER SECTION REGARDING UPDATES ON RFW. TODAY...VERY WARM AIR MASS WILL BE IN PLACE TODAY WITH DEEP SW FLOW ALOFT AND WAA ALONG/EAST OF SURFACE LOW. CIRRUS IS ALREADY CONSIDERABLY MORE EXTENSIVE IN COVERAGE THAN MODELS WOULD INDICATE AND SATELLITE TRENDS GENERALLY SUPPORT THIS TREND CONTINUING. THIS COMPLICATES OUR HIGH TEMP FORECAST AND POTENTIAL MIXING HEIGHTS FOR WIND/TDS. WITH SURFACE LOW SHIFTING TOWARD THE NORTHERN HALF OF OUR CWA AHEAD OF APPROACHING COLD FRONT WILL RESULT IN STRONGEST SURFACE GRADIENT REMAINING EAST THROUGH THE DAY. BETTER MIXING WOULD STILL ALLOW FOR GUSTS IN THE 40-45 MPH RANGE TODAY...HOWEVER DUE TO THE CIRRUS THESE STRONGER GUSTS MAY NOT BE REALIZED THIS AFTERNOON. I LEANED TOWARD THE "COOLER" END OF GUIDANCE FOR HIGHS...WHICH STILL SUPPORTS DAILY RECORDS AT MOST LOCATIONS (UPPER 70S/NEAR 80). IF WE CAN SEE GOOD BREAKS AND LESS OPAQUE CLOUD COVER WE MAY BE LOOKING AT MONTHLY RECORDS. TONIGHT...UPPER LOW MOVES FROM PACIFIC NORTHWEST ACROSS NORTHERN PLAINS WITH NEGATIVELY TILTED OPEN WAVE ACROSS NORTHERN NEBRASKA TONIGHT. THE ASSOCIATED COLD FRONT WILL DROP SOUTH ACROSS OUR CWA AROUND 06Z. MODELS SHOW A VERY STRONG LLJ DEVELOPING OVER OUR CWA WITH H85 WINDS 60KT OR HIGHER. GFS IS THE STRONGEST ON BL WINDS...AND MAY BE RUNNING HIGH AS THE STRONG FRONTAL INVERSION (AIDED BY RADIATIONAL COOLING) COULD LIMIT MIXING. 3HR PRESSURE RISES 8-10 MB BEHIND THIS FRONT WILL SUPPORT WINDY CONDITIONS...I AM JUST NOT AS CONFIDENT THAT THE STRONGEST WINDS ALOFT WILL MAKE IT TO THE SURFACE. LOCATIONS FURTHER NORTH WILL BE AIDED BY STRONG SUBSIDENCE BEHIND TROUGH AXIS (HIGHLIGHTED BY STRONG PV ANOMALY ON DYNAMIC TROPOPAUSE FIELD). THIS TYPE OF PATTERN TENDS TO BE SHORT LIVED IN NATURE WITH STRONGEST GUSTS OVER SHORTER TIME SPANS. I INCREASED WIND GUSTS ACROSS THE NORTHERN HALF OF OUR CWA TO INCLUDE GUSTS 50-55 MPH TONIGHT...BUT DECIDED AGAINST HIGH WIND WATCH ISSUANCE DUE TO UNCERTAINTY REGARDING NIGHTTIME MIXING OVER OUR CWA. FRIDAY-SATURDAY...WESTERLY FLOW WILL BE IN PLACE THROUGH THESE PERIOD WITH DEEP DRY AIR AND ABOVE NORMAL TEMPS. HIGHS SHOULD BE 10 TO 15 DEGREES COOLER AFTER THE FROPA TONIGHT...HOWEVER THEY WILL STILL BE IN THE 60S ACROSS OUR CWA (15-20F ABOVE NORMAL). .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 147 AM MST THU FEB 18 2016 UPPER FLOW WILL BE WESTERLY SUNDAY AND MONDAY FOLLOWED BY A COUPLE OF TROUGHS TUESDAY AND WEDNESDAY. SURFACE HIGH PRESSURE WILL RESIDE OVER THE HIGH PLAINS SUNDAY. A TROUGH WILL MOVE INTO EASTERN COLORADO MONDAY AND THEN SHIFT EAST TUESDAY WITH A COLD FRONT MOVING INTO THE REGION. SURFACE HIGH PRESSURE WILL CONTINUE WEDNESDAY. A COUPLE OF SHORTWAVE TROUGHS WILL BRING A SLIGHT CHANCE OF RAIN AND SNOW TO THE FA MONDAY NIGHT AND TUESDAY. THE MOISTURE AND LIFT SUPPORT AT LEAST SLIGHT CHANCE POPS. OTHERWISE ALL OTHER PERIODS WILL BE DRY. MAX TEMPERATURES FROM SUNDAY THROUGH WEDNESDAY SHOULD REACH THE LOWER 50S WITH SOME MID TO UPPER 40S TUESDAY. MIN TEMPERATURES SHOULD BE IN THE MID AND UPPER 20S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 427 AM MST THU FEB 18 2016 VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. GUSTY WINDS SHOULD DEVELOP BY MIDDAY...WITH SOUTH WINDS GUSTING 30-35KT AT KGLD (LIGHTER AT KMCK WHERE GRADIENT IS WEAKER). A STRONG COLD FRONT WILL MOVE THROUGH THE REGION TONIGHT WITH WINDS SHIFTING TO THE WEST. STRONG WINDS WILL BE POSSIBLE WITH GUSTS 38-45KT EXPECTED (STRONGEST AT KMCK). STRONGER GUSTS ARE POSSIBLE...BUT CONFIDENCE IN OCCURRENCE AND DURATION IS TOO LOW TO INCLUDE IN TAFS. DUE TO THE PRESENCE OF A VERY STRONG LLJ...LOW LEVEL WIND SHEER WILL ALSO BE POSSIBLE. THE BEST CHANCE WILL BE AT KMCK LATE THIS EVENING THROUGH EARLY FRIDAY MORNING. && .FIRE WEATHER... ISSUED AT 322 AM MST THU FEB 18 2016 FORECAST APPEARS TO BE IN LINE FOR CRITICAL FIRE WEATHER CONDITIONS AT LEAST THE SOUTHERN HALF OF OUR CWA. THERE IS LESS CERTAINTY NORTH OF INTERSTATE 70 AS A RESULT OF HIGH CLOUD COVER POTENTIALLY LIMITING MIXING WHICH IMPACTS RH AND WINDS. LOWER BOUNDARY LAYER WINDS ADVERTISED BY MOST GUIDANCE IN OUR NORTH AS A RESULT OF A SHIFT IN SURFACE LOW POSITION ALSO LOWERS CONFIDENCE IN MEETING A 3HR DURATION OF WINDS IN OUR NORTHERN CWA. I WAS COMFORTABLE KEEPING CURRENT RED FLAG WARNING IN PLACE AND ADDING THOMAS AND SHERIDAN TO RFW AS THESE LOCATIONS SHOULD BE ABLE TO MEET THE 3HR CROSSOVER OF WIND/RH EVEN IF WINDS ARE NOT QUITE AS STRONG. I DECIDED TO CANCEL THE FIRE WEATHER WATCH FOR YUMA (CO)...CHEYENNE (KS)...AND RAWLINS (KS) AS CONFIDENCE IS MUCH LOWER AND WE ARE TOO CLOSE TO THE EVENT TO HANG ONTO THE WATCH ANY LONGER. HAVING SAID THIS...IF CLOUD COVER ENDS UP BEING MUCH LESS THIS AFTERNOON AND FULL MIXING IS ACHIEVED THE RFW MAY NEED TO BE EXPANDED NORTH. THIS SITUATION NEEDS TO BE MONITORED. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE ALONG THE CO/KS BORDER FRIDAY AFTERNOON AS LEE TROUGH BEGINS TO REDEVELOP AND SOUTHERLY SURFACE GRADIENT INCREASES. THIS WILL BE MONITORED...HOWEVER CONFIDENCE IS LOW IN REACHING THE 3HR REQUIREMENT FOR FIRE WEATHER HIGHLIGHTS. && .CLIMATE... ISSUED AT 322 AM MST THU FEB 18 2016 RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES TODAY. SITE.............DAILY RECORD...CURRENT FORECAST GOODLAND, KS.........74...............78 MCCOOK, NE...........82...............75 BURLINGTON,CO........74...............78 HILL CITY,KS.........75...............82 COLBY, KS............81...............79 TRIBUNE, KS..........79...............82 YUMA, CO.............73...............74 CURRENT FEBRUARY MONTHLY HIGH TEMP RECORDS... GOODLAND.....81 (02-28-2006 AND PREVIOUS YEARS) MCCOOK.......83 (02-23-1933 AND PREVIOUS YEARS) BURLINGTON...82 (02-11-1962) HILL CITY....86 (02-28-2006 AND PREVIOUS YEARS) COLBY........83 (02-12-1911) TRIBUNE......81 (02-20-1981) YUMA.........79 (02-12-1962 AND PREVIOUS YEARS) && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING FROM 11 AM MST /NOON CST/ THIS MORNING TO 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ013>015-027>029-041- 042. CO...RED FLAG WARNING FROM 11 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR COZ253-254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...FS AVIATION...DR FIRE WEATHER...DR CLIMATE...DR
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
511 AM CST THU FEB 18 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 323 AM CST THU FEB 18 2016 High clouds on water vapor imagery were noted lifting over the upper ridge building into the western high plains this morning. A broad and strong upper trough entering the Pac NW was streaming steady moisture off the southern CA coast towards the southwest Conus. Sfc Observations showed the developing lee trough across eastern CO inducing southerly winds to increase between 10 and 15 mph. Low level moisture across southern TX was quickly advecting northward with a strong 50+ kt low level jet ongoing and anticipated to increase after sunrise. This low level moisture advection is a major factor as to how low RH readings fall during the late afternoon as a stout dryline mixes eastward across KS. Fire weather details follow below on the current thinking. Forecast was based on a combination of the RAP and HRRR (previous and current runs) with the low 40 degree dewpoints and highs in the lower 70s for east central/north central areas. North central KS may be able to mix out to the upper 70s as forecast soundings are consistent in the warm inversion layer reaching the sfc in addition to the drier air. Wind speeds are also of concern with speeds expected to increase shortly after sunrise between 25 and 35 mph sustained with gusts between 40 and 50 mph possible. For this reason, have expanded the wind advisory for areas generally along and south of Interstate 70. For tonight, winds are expected to stay up between 15 and 25 mph sustained as they veer to the west with the upper trough crossing over Nebraska. High clouds increase while temps stay mild in the lower 50s. .LONG TERM...(Friday through Wednesday) Issued at 323 AM CST THU FEB 18 2016 A quasi zonal pattern sets up for Friday and through the weekend with the bulk of energy passing to the north of the forecast area. Models continue to show low level moisture advection into east central KS for Saturday and Saturday night as a subtle piece of energy passes across the state. Both the NAM and GFS suggest there will be little to no instability however and model progs of 850 winds remain rather light for this time of year. Nevertheless there has been a persistent signal from the models for the possibility for showers and thunderstorms so have maintained a small chance POP for Saturday afternoon and Saturday evening. By Sunday morning, a cold front is expected to push south of the forecast area with dry air moving in. This should bring and end to the precip changes as well as cooler temps for Sunday. Temps for Friday and Saturday should remain well above normal. Forecast soundings show the boundary layer mixing fairly deeply on Friday but also bring in some cooler temps at 850 MB such that adiabatic mixing would only support highs in the mid and upper 60s. Because of this have shaved a degree or two off the highs from the prev forecast. The airmass stays pretty similar for Saturday. The one wild car is possible low clouds moving into eastern KS and limiting insolation. For now have continued with highs in the mid and upper 60s for Saturday. For next week, the models are suggesting the pattern becomes more amplified with a return to northwest flow for the central plains. However there are differences in how the pattern sets up and where week waves within the flow move. Its plausible that there could be some light precip with these passing waves, similar to what we experienced earlier this week. However low confidence in the small scale features preclude a mention of precip chances at this time. With the return of northwest flow, models bring the occasional ridge of high pressure through the plains. This is expected to keep temps cooler with highs in the 50s and lows around freezing next week. && .AVIATION...(For the 12Z TAFS through 12Z Friday Morning) Issued at 508 AM CST THU FEB 18 2016 VFR prevails through period with main concern being strong southerly winds. Profiler winds throughout Kansas depict strong low level wind shear above 1500 feet from the south continuing through 14Z. Thereafter, south sfc winds increase to above 20 kts sustained with gusts in upwards of 35 kts. The strong winds gradually veer to the southwest overnight as the system passes through. && .FIRE WEATHER... Issued at 323 AM CST THU FEB 18 2016 High resolution guidance is still struggling on dewpoints during the afternoon as it appears to still overestimate the amount of moisture advection from the southwest while underestimating the depth of vertical mixing in regards to the drier air aloft. Forecast was collaborated to side closer to the RAP and HRRR solutions which represent an even compromise of RH values falling to the low and middle 30 percent range for most of the area. Most uncertain area is across north central Kansas where stronger mixing aloft and from the dryline may help realize RH values dropping sharply towards the upper teen to lower 20 percent range during the late afternoon. Regardless of the RH values being borderline, winds sustained at 25 to 35 mph with gusts in upwards of 45 to 50 mph will easily promote uncontrolled fire growth given the critical fuels reported. Therefore have upgraded the watch to a Red Flag Warning in effect at 11 AM until 6 PM this evening for the entire area. Uncertainty increases for this evening as RH values rise. Winds remain strong however so any fire that forms during the afternoon will remain uncontrollable overnight. Have maintained the watch overnight for the next shift to review. For Friday, dry air is still expected to overspread the forecast area with min RH values falling to around 20 percent during the afternoon. However models show the pressure gradient relaxing pretty quickly in the morning Friday and wind speeds are forecast to be quite a bit lighter. There remains the possibility to see some gusts around 20 MPH especially across northern KS where the gradient will be slower to relax. But the overall trend in the models has been for weaker winds. Will keep the fire weather watch in tact for now because of the dry air, but there is a real possibility that conditions will not make it to red flag on Friday. && .TOP Watches/Warnings/Advisories... Red Flag Warning from 11 AM this morning to 7 PM CST this evening for KSZ008>012-020>024-026-034>040-054>056-058-059. Fire Weather Watch from this evening through Friday afternoon for KSZ008>012-020>024-026-034>040-054>056-058-059. Wind Advisory from 11 AM this morning to 7 PM CST this evening for KSZ021>024-026-034>040-054>056-058-059. && $$ SHORT TERM...Bowen LONG TERM...Wolters AVIATION...Bowen FIRE WEATHER...Bowen/Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
322 AM MST THU FEB 18 2016 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 322 AM MST THU FEB 18 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW RIDGE IN PLACE ACROSS THE CENTRAL US...WITH A STRONG UPPER LOW OFF THE PACIFIC NW COAST. 130-145 KT 300MB JET WAS OBSERVED OVER CALIFORNIA ON 00Z RAOBS AND ON WV THIS CAN BE SEE AS STRONG AREA OF CLEARING NOSING INTO DIFFLUENT REGION BETWEEN RIDING AND UPPER LOW. DEEP SW FLOW IS IN PLACE ACROSS THE CENTRAL ROCKIES WITH PLUME OF THICK HIGH CLOUD COVER STREAMING INTO THE PLAINS. AT THE SURFACE...LOW PRESSURE IS IN PLACE OVER EASTERN COLORADO WITH DRY LINE APPROXIMATELY FROM LAMAR COLORADO SOUTH. FOCUS ON THIS FORECAST PERIOD IS ON FIRE WEATHER TODAY AND A POSSIBLE HIGH WIND EVENT TONIGHT. SEE FIRE WEATHER SECTION REGARDING UPDATES ON RFW. TODAY...VERY WARM AIR MASS WILL BE IN PLACE TODAY WITH DEEP SW FLOW ALOFT AND WAA ALONG/EAST OF SURFACE LOW. CIRRUS IS ALREADY CONSIDERABLY MORE EXTENSIVE IN COVERAGE THAN MODELS WOULD INDICATE AND SATELLITE TRENDS GENERALLY SUPPORT THIS TREND CONTINUING. THIS COMPLICATES OUR HIGH TEMP FORECAST AND POTENTIAL MIXING HEIGHTS FOR WIND/TDS. WITH SURFACE LOW SHIFTING TOWARD THE NORTHERN HALF OF OUR CWA AHEAD OF APPROACHING COLD FRONT WILL RESULT IN STRONGEST SURFACE GRADIENT REMAINING EAST THROUGH THE DAY. BETTER MIXING WOULD STILL ALLOW FOR GUSTS IN THE 40-45 MPH RANGE TODAY...HOWEVER DUE TO THE CIRRUS THESE STRONGER GUSTS MAY NOT BE REALIZED THIS AFTERNOON. I LEANED TOWARD THE "COOLER" END OF GUIDANCE FOR HIGHS...WHICH STILL SUPPORTS DAILY RECORDS AT MOST LOCATIONS (UPPER 70S/NEAR 80). IF WE CAN SEE GOOD BREAKS AND LESS OPAQUE CLOUD COVER WE MAY BE LOOKING AT MONTHLY RECORDS. TONIGHT...UPPER LOW MOVES FROM PACIFIC NORTHWEST ACROSS NORTHERN PLAINS WITH NEGATIVELY TILTED OPEN WAVE ACROSS NORTHERN NEBRASKA TONIGHT. THE ASSOCIATED COLD FRONT WILL DROP SOUTH ACROSS OUR CWA AROUND 06Z. MODELS SHOW A VERY STRONG LLJ DEVELOPING OVER OUR CWA WITH H85 WINDS 60KT OR HIGHER. GFS IS THE STRONGEST ON BL WINDS...AND MAY BE RUNNING HIGH AS THE STRONG FRONTAL INVERSION (AIDED BY RADIATIONAL COOLING) COULD LIMIT MIXING. 3HR PRESSURE RISES 8-10 MB BEHIND THIS FRONT WILL SUPPORT WINDY CONDITIONS...I AM JUST NOT AS CONFIDENT THAT THE STRONGEST WINDS ALOFT WILL MAKE IT TO THE SURFACE. LOCATIONS FURTHER NORTH WILL BE AIDED BY STRONG SUBSIDENCE BEHIND TROUGH AXIS (HIGHLIGHTED BY STRONG PV ANOMALY ON DYNAMIC TROPOPAUSE FIELD). THIS TYPE OF PATTERN TENDS TO BE SHORT LIVED IN NATURE WITH STRONGEST GUSTS OVER SHORTER TIME SPANS. I INCREASED WIND GUSTS ACROSS THE NORTHERN HALF OF OUR CWA TO INCLUDE GUSTS 50-55 MPH TONIGHT...BUT DECIDED AGAINST HIGH WIND WATCH ISSUANCE DUE TO UNCERTAINTY REGARDING NIGHTTIME MIXING OVER OUR CWA. FRIDAY-SATURDAY...WESTERLY FLOW WILL BE IN PLACE THROUGH THESE PERIOD WITH DEEP DRY AIR AND ABOVE NORMAL TEMPS. HIGHS SHOULD BE 10 TO 15 DEGREES COOLER AFTER THE FROPA TONIGHT...HOWEVER THEY WILL STILL BE IN THE 60S ACROSS OUR CWA (15-20F ABOVE NORMAL). .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 147 AM MST THU FEB 18 2016 UPPER FLOW WILL BE WESTERLY SUNDAY AND MONDAY FOLLOWED BY A COUPLE OF TROUGHS TUESDAY AND WEDNESDAY. SURFACE HIGH PRESSURE WILL RESIDE OVER THE HIGH PLAINS SUNDAY. A TROUGH WILL MOVE INTO EASTERN COLORADO MONDAY AND THEN SHIFT EAST TUESDAY WITH A COLD FRONT MOVING INTO THE REGION. SURFACE HIGH PRESSURE WILL CONTINUE WEDNESDAY. A COUPLE OF SHORTWAVE TROUGHS WILL BRING A SLIGHT CHANCE OF RAIN AND SNOW TO THE FA MONDAY NIGHT AND TUESDAY. THE MOISTURE AND LIFT SUPPORT AT LEAST SLIGHT CHANCE POPS. OTHERWISE ALL OTHER PERIODS WILL BE DRY. MAX TEMPERATURES FROM SUNDAY THROUGH WEDNESDAY SHOULD REACH THE LOWER 50S WITH SOME MID TO UPPER 40S TUESDAY. MIN TEMPERATURES SHOULD BE IN THE MID AND UPPER 20S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1024 PM MST WED FEB 17 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THE MAIN STORY CONTINUES TO BE THE WIND. FOR KGLD...LLWS WILL BE IN PLACE UNTIL NEAR 12Z. AFTER HEATING/MIXING THE SOUTHWEST WILL INCREASE AND BECOME GUSTY. THE STRONGEST WINDS DURING THE DAY WILL BE IN THE AFTERNOON WITH SUSTAINED WINDS NEAR 24 KNOTS WITH GUSTS TO NEAR 36 KNOTS. LATE IN THE AFTERNOON INTO EARLY EVENING THE WINDS TEMPORARILY DECREASE. HOWEVER DURING THE MID TO LATE AFTERNOON EVENING THE WINDS INCREASE AGAIN TO SIMILAR VALUES AS SEEN DURING THE AFTERNOON. FOR KMCK...LESS WIND EXPECTED HERE. HOWEVER LLWS SHEAR WILL BE IN PLACE UNTIL NEAR 12Z. AFTER THAT THE WINDS INCREASE NEAR 03Z WITH SUSTAINED WINDS NEAR 15 KNOTS AND GUSTS NEAR 23 KNOTS. THAT IS ALSO WHEN THE LLWS WILL DEVELOP AGAIN. && .FIRE WEATHER... ISSUED AT 322 AM MST THU FEB 18 2016 FORECAST APPEARS TO BE IN LINE FOR CRITICAL FIRE WEATHER CONDITIONS AT LEAST THE SOUTHERN HALF OF OUR CWA. THERE IS LESS CERTAINTY NORTH OF INTERSTATE 70 AS A RESULT OF HIGH CLOUD COVER POTENTIALLY LIMITING MIXING WHICH IMPACTS RH AND WINDS. LOWER BOUNDARY LAYER WINDS ADVERTISED BY MOST GUIDANCE IN OUR NORTH AS A RESULT OF A SHIFT IN SURFACE LOW POSITION ALSO LOWERS CONFIDENCE IN MEETING A 3HR DURATION OF WINDS IN OUR NORTHERN CWA. I WAS COMFORTABLE KEEPING CURRENT RED FLAG WARNING IN PLACE AND ADDING THOMAS AND SHERIDAN TO RFW AS THESE LOCATIONS SHOULD BE ABLE TO MEET THE 3HR CROSSOVER OF WIND/RH EVEN IF WINDS ARE NOT QUITE AS STRONG. I DECIDED TO CANCEL THE FIRE WEATHER WATCH FOR YUMA (CO)...CHEYENNE (KS)...AND RAWLINS (KS) AS CONFIDENCE IS MUCH LOWER AND WE ARE TOO CLOSE TO THE EVENT TO HANG ONTO THE WATCH ANY LONGER. HAVING SAID THIS...IF CLOUD COVER ENDS UP BEING MUCH LESS THIS AFTERNOON AND FULL MIXING IS ACHIEVED THE RFW MAY NEED TO BE EXPANDED NORTH. THIS SITUATION NEEDS TO BE MONITORED. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE ALONG THE CO/KS BORDER FRIDAY AFTERNOON AS LEE TROUGH BEGINS TO REDEVELOP AND SOUTHERLY SURFACE GRADIENT INCREASES. THIS WILL BE MONITORED...HOWEVER CONFIDENCE IS LOW IN REACHING THE 3HR REQUIREMENT FOR FIRE WEATHER HIGHLIGHTS. && .CLIMATE... ISSUED AT 322 AM MST THU FEB 18 2016 RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES TODAY. SITE.............DAILY RECORD...CURRENT FORECAST GOODLAND, KS.........74...............78 MCCOOK, NE...........82...............75 BURLINGTON,CO........74...............78 HILL CITY,KS.........75...............82 COLBY, KS............81...............79 TRIBUNE, KS..........79...............82 YUMA, CO.............73...............74 CURRENT FEBRUARY MONTHLY HIGH TEMP RECORDS... GOODLAND.....81 (02-28-2006 AND PREVIOUS YEARS) MCCOOK.......83 (02-23-1933 AND PREVIOUS YEARS) BURLINGTON...82 (02-11-1962) HILL CITY....86 (02-28-2006 AND PREVIOUS YEARS) COLBY........83 (02-12-1911) TRIBUNE......81 (02-20-1981) YUMA.........79 (02-12-1962 AND PREVIOUS YEARS) && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING FROM 11 AM MST /NOON CST/ THIS MORNING TO 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ013>015-027>029-041- 042. CO...RED FLAG WARNING FROM 11 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR COZ253-254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...FS AVIATION...BULLER FIRE WEATHER...DR CLIMATE...DR
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
447 AM CST THU FEB 18 2016 .UPDATE... ISSUED AT 436 AM CST THU FEB 18 2016 A CHECK ON THE NAM SHOWS ELEVATED INSTABILITY TONIGHT WITH 100 TO 200 J/KG OF CAPE. THE REFLECTIVITY PRODUCT AND K INDICES OVER 30 SUGGEST ISOLATED HIGH BASED THUNDERSTORMS ARE POSSIBLE. A NEW FORECAST HAS BEEN ISSUED FOR THIS FEATURE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 322 AM CST THU FEB 18 2016 TODAY AND TONIGHT...A BLEND OF THE 4 GUIDANCE DATA SET PLUS BIAS CORRECTION SUGGESTS HIGHS IN THE LOWER 70S TODAY. IT LOOKS LIKE HIGH CLOUDS WILL BE IN AND OUT OF THE FCST AREA SO THE WARMEST NUMBERS PROBABLY WOULD NOT VERIFY. THE BAROCLINIC LEAF STRETCHING ACROSS THE WRN U.S. WILL MOVE OVER THE FCST AREA TODAY. THE LATEST MODELS SHOW HIGH WINDS MORE LIKELY TONIGHT. THE RAP MODEL INDICATES AN ASTONISHING 3 HR PRESSURE RISE OF 13 MB NEAR RAWLINS WY AT 01Z TONIGHT. THIS COUPLED WITH A PV1.5 ANOMALY AND H850 WINDS RISING TO 60-70KT PRODUCES A MODERATE OR HIGHER POTENTIAL FOR HIGH WINDS ACROSS WRN AND NCNTL NEB. THE GFS20 CLOCKS THE COLD FRONT MOVING EAST AT 60 MPH. THE NAM FCSTS WIND GUSTS APPROACHING 70 MPH IN SOME LOCATIONS. THIS WOULD BE THE MAX WE WOULD EXPECT ASSUMING A MIXED LAYER FORMS ALONG THE COLD FRONT. PEAK WIND GUSTS WOULD LAST 1 TO 2 HOURS AS THE FRONT RACES THROUGH THE FCST AREA BETWEEN 03Z AND 09Z. THE PV1.5 ANOMALY SUGGESTS INTERSTATE 80 AND NCNTL NEB ALONG AND EAST OF HIGHWAY 83 WOULD BE MOST FAVORED FOR HIGH WINDS. THE NAM WIND GUSTS INDICATE ALL ZONES. THE GFS SOUNDINGS FOR NORTH PLATTE SHOW A MIXED LAYER EXTENDING TO 550MB AT 03Z JUST AHEAD OF THE COLD FRONT WHICH COLLAPSES TO 780MB BEHIND THE FRONT. THE 500M AGL TEMPERATURE FALLS FROM 73F AT 03Z TO 47F AT 06Z WITH 55 TO 65 KT WINDS AT THIS LEVEL...OFF THE CHARTS. A HIGH WIND WATCH IS IN PLACE FOR ALL ZONES TONIGHT. THE RAP AND HRRR MODELS COULD PERHAPS CULL SOME COUNTIES FROM THE WATCH LATER TODAY. THE MODEL CONSENSUS SUGGEST SPRINKLES OR ISOLATED SHOWERS TONIGHT...MAINLY ALONG AND NORTH OF HIGHWAY 20. THIS WOULD EASILY MIX THE STRONG WINDS ALOFT DOWN TO THE SFC IN THESE AREAS. THUS THE CONVECTION MAY WORK FOR HIGH WINDS WHERE THE PV1.5 ANOMALY IS ABSENT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 322 AM CST THU FEB 18 2016 MID RANGE...FRIDAY AND SATURDAY...MAIN FORECAST CHALLENGES ARE TEMPERATURES AND WIND. GUSTY WINDS CONTINUE IN THE WAKE OF THE STRONG PACIFIC FRONT AND PV ANOMALY WHILE DOWNSLOPE WINDS AND WARM 850HPA TEMPS CONTRIBUTE TO WELL ABOVE NORMAL HIGHS. GFS AND NAM KEEP LOW/MID LEVEL WINDS AOA 40 KTS THROUGH 18Z FRIDAY...PRIMARILY ACROSS THE NORTHERN HALF OF THE FORECAST AREA. WIDESPREAD SUBSIDENCE WILL RESULT IN FAIR CONDITIONS AND A WELL MIXED BOUNDARY LAYER. FORECAST SOUNDINGS SHOW MIXING TO 700HPA AT KLBF AND KVTN FRIDAY AFTERNOON WITH NEARLY UNIDIRECTIONAL WINDS. EDGED MAX TEMPS CLOSER TO THE MAV AND ECS GUIDANCE...WHICH BOTH SHOW UPPER 60S FOR MOST OF WESTERN NEBRASKA. A WEAK FRONT DROPS SOUTH ACROSS THE REGION SATURDAY...RESULTING IN SLIGHTLY COOLER MAX TEMPS NORTH BUT ABOUT THE SAME SOUTH. SOUNDINGS STILL INDICATE GOOD MIXING SATURDAY...BUT WIND WILL NOT BE A BIG AN ISSUE AS THE MID AND UPPER LEVEL SUPPORT WILL HAVE MOVED EAST. LONG RANGE...SUNDAY TO WEDNESDAY...A COUPLE WAVES TRAVERSE THE AREA SUNDAY AND TUESDAY WHILE 500HPA FLOW TRANSITIONS FROM QUASI ZONAL TO NORTHWEST. A SURFACE HIGH BUILDING OVER THE NORTHERN PLAINS AND 850HPA CAA LEADING TO TEMPS NEAR 0C AT 18Z SUNDAY WILL TAKE HIGHS MUCH CLOSER TO NORMAL. FRONTOGENESIS LOOKS IMPRESSIVE EARLY SUNDAY...BUT MOISTURE AND LIFT ARE LACKING. SOUTHERLY FLOW RETURNS MONDAY WITH LITTLE IN TERMS OF TEMPERATURE RECOVERY. THE GFS AND EURO SHOW BETTER MOISTURE AND MARGINAL LIFT FOR THE SYSTEM ON TUESDAY...HOWEVER DISCREPANCIES REMAIN WITH THE TIMING OF THE BEST FORCING. EXTENDED PROCEDURE INTRODUCED SCHC POPS...BUT DECIDED TO KEEP DRY WITH THIS FORECAST PACKAGE DUE TO LOW CONFIDENCE. MORE DOWNSLOPING WINDS WITH A 850HPA RIDGE AXIS MOVING THROUGH THE SANDHILLS WEDNESDAY...PUSHING HIGHS INTO THE LOWER 50S AGAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1145 PM CST WED FEB 17 2016 FOR BOTH THE KLBF AND KVTN TERMINALS...EXPECT SCATTERED TO BROKEN CIGS OF 20000 FT AGL OVER THE NEXT 24 HOURS. WINDS WILL BE FROM THE SOUTH OVERNIGHT AT 10 KTS...SHIFTING TO THE SOUTHWEST AT 10 TO 20 KTS THURSDAY AFTERNOON. WINDS WILL TEMPORARILY SHIFT TO THE SOUTH AT 10 KTS THURSDAY EVENING WITH AN ABRUPT SHIFT TO THE WEST AFTER 03Z FRIDAY. WIND SPEEDS WILL QUICKLY INCREASE TO 15 TO 25 KTS WITH GUSTS APPROACHING 35 KTS. && .LBF WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM THIS EVENING THROUGH LATE TONIGHT FOR NEZ004>010-022>029-035>038-056>059-069>071-094. && $$ UPDATE...CDC SHORT TERM...CDC LONG TERM...SNIVELY AVIATION...BUTTLER
AREA FORECAST DISCUSSION...CORRECTED
NWS NORMAN OK
529 AM CST THU FEB 18 2016 .AVIATION... LOW-LEVEL WIND SHEAR THIS MORNING AND WINDY CONDITIONS WILL BE THE PRIMARY AVIATION ISSUES TODAY. MORNING SOUNDING FROM NORMAN INDICATES 50 KNOT WINDS AT ABOUT FL023... SO WIND SHEAR WILL BE STRONG UNTIL LATER THIS MORNING WHEN LOW-LEVELS BECOME MORE MIXED AND SURFACE WINDS INCREASE. WIDESPREAD 25-30 KNOTS SUSTAINED WINDS ARE EXPECTED WITH GUSTS OF 35-40 KNOTS. TODAY WILL ALSO BE A DAY OF POTENTIAL WILDFIRES... SO THERE WILL BE LOW CHANCES OF VISIBILITIES RESTRICTED BY SMOKE IF A WILDFIRE SHOULD DEVELOP NEAR AN AIRPORT. && .PREV DISCUSSION... /ISSUED 433 AM CST THU FEB 18 2016/ DISCUSSION... MAIN ISSUE AS EXPECTED IS THE FIRE WEATHER CONCERN FOR THIS AFTERNOON. WINDY CONDITIONS ARE EXPECTED TODAY AS SURFACE TROF IN THE HIGH PLAINS DEEPENS AND INCREASES PRESSURE GRADIENT. LOW-LEVEL MOISTURE IS EVEN SLOWER TO RETURN THAN PREVIOUSLY THOUGHT. ONE MOISTURE AXIS IS POKING UP THROUGH WEST TEXAS TOWARD LUBBOCK WITH MID TO UPPER 40S DEWPOINTS. THE SECOND AXIS IS DEVELOPING UP THROUGH SAN ANTONIO WITH LOWER 50S DEWPOINTS NOW REACHING LAMPASAS AND GEORGETOWN TEXAS. MORNING SOUNDINGS WILL GIVE BETTER IDEA OF MOISTURE DEPTH... BUT RECENT HISTORY AND CURRENT TRENDS WOULD SUGGEST LOWER DEWPOINTS THAN SYNOPTIC MODELS PROGS. EVEN THE HRRR AND RAP WOULD BRING SOME DEWPOINTS NEAR 50 INTO OKLAHOMA THIS AFTERNOON... BUT THAT SEEMS LIKE A STRETCH. INITIALIZED DEWPOINT GRIDS WITH RAP... BUT THEN GENERALLY LOWERED VALUES MORE /EXCEPT FOR INCREASING THEM SOMEWHAT IN THE EAST THIS MORNING GIVEN CURRENT ANALYSIS/. COORDINATION YESTERDAY WITH BOTH OKLAHOMA AND TEXAS FORESTRY DEPARTMENTS INDICATE A DESIRE TO HOIST THE RED FLAG TODAY AREAWIDE GIVEN THE EXPECTED WIND SPEEDS AND FUEL LOADING... DESPITE RH VALUES THAT MAY NOT QUITE REACH CRITERIA IN THE CENTRAL AND EASTERN SECTIONS. EVENING SHIFT ALREADY UPGRADED AND WILL CONTINUE THIS WARNING. ALSO WILL MAINTAIN THE CURRENT WIND ADVISORY AS WELL. AGAIN... ABOVE AVERAGE TEMPERATURES WILL PERSIST THROUGH THE WEEKEND WITH TEMPS CLOSER TO AVERAGE EARLY NEXT WEEK. THERE WILL BE SOME PRECIPITATION CHANCES SUNDAY THROUGH TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 78 57 74 54 / 0 0 0 0 HOBART OK 81 55 76 52 / 0 0 0 0 WICHITA FALLS TX 83 57 80 56 / 0 0 10 0 GAGE OK 86 49 74 44 / 0 0 0 0 PONCA CITY OK 78 55 73 49 / 0 0 0 0 DURANT OK 75 58 75 58 / 0 10 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING FROM NOON TODAY TO 7 PM CST THIS EVENING FOR OKZ004>048-050>052. WIND ADVISORY FROM NOON TODAY TO 7 PM CST THIS EVENING FOR OKZ004>042-044>046-050. TX...RED FLAG WARNING FROM NOON TODAY TO 7 PM CST THIS EVENING FOR TXZ083>090. WIND ADVISORY FROM NOON TODAY TO 7 PM CST THIS EVENING FOR TXZ083>090. && $$ FIX WORDS THAT HAD BEEN CUT OFF
AREA FORECAST DISCUSSION
NWS NORMAN OK
433 AM CST THU FEB 18 2016 .DISCUSSION... MAIN ISSUE AS EXPECTED IS THE FIRE WEATHER CONCERN FOR THIS AFTERNOON. WINDY CONDITIONS ARE EXPECTED TODAY AS SURFACE TROF IN THE HIGH PLAINS DEEPENS AND INCREASES PRESSURE GRADIENT. LOW-LEVEL MOISTURE IS EVEN SLOWER TO RETURN THAN PREVIOUSLY THOUGHT. ONE MOISTURE AXIS IS POKING UP THROUGH WEST TEXAS TOWARD LUBBOCK WITH MID TO UPPER 40S DEWPOINTS. THE SECOND AXIS IS DEVELOPING UP THROUGH SAN ANTONIO WITH LOWER 50S DEWPOINTS NOW REACHING LAMPASAS AND GEORGETOWN TEXAS. MORNING SOUNDINGS WILL GIVE BETTER IDEA OF MOISTURE DEPTH... BUT RECENT HISTORY AND CURRENT TRENDS WOULD SUGGEST LOWER DEWPOINTS THAN SYNOPTIC MODELS PROGS. EVEN THE HRRR AND RAP WOULD BRING SOME DEWPOINTS NEAR 50 INTO OKLAHOMA THIS AFTERNOON... BUT THAT SEEMS LIKE A STRETCH. INITIALIZED DEWPOINT GRIDS WITH RAP... BUT THEN GENERALLY LOWERED VALUES MORE /EXCEPT FOR INCREASING THEM SOMEWHAT IN THE EAST THIS MORNING GIVEN CURRENT ANALYSIS/. COORDINATION YESTERDAY WITH BOTH OKLAHOMA AND TEXAS FORESTRY DEPARTMENTS INDICATE A DESIRE TO HOIST THE RED FLAG TODAY AREAWIDE GIVEN THE EXPECTED WIND SPEEDS AND FUEL LOADING... DESPITE RH VALUES THAT MAY NOT QUITE REACH CRITERIA IN THE CENTRAL AND EASTERN SECTIONS. EVENING SHIFT ALREADY UPGRADED AND WILL CONTINUE THIS WARNING. ALSO WILL MAINTAIN THE CURRENT WIND ADVISORY AS WELL. AGAIN... ABOVE AVERAGE TEMPERATURES WILL PERSIST THROUGH THE WEEKEND WITH TEMPS CLOSER TO AVERAGE EARLY NEXT WEEK. THERE WILL BE SOME PRECIPITATION CHANCES SUNDAY THROUGH TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 78 57 74 54 / 0 0 0 0 HOBART OK 81 55 76 52 / 0 0 0 0 WICHITA FALLS TX 83 57 80 56 / 0 0 10 0 GAGE OK 86 49 74 44 / 0 0 0 0 PONCA CITY OK 78 55 73 49 / 0 0 0 0 DURANT OK 75 58 75 58 / 0 10 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING FROM NOON TODAY TO 7 PM CST THIS EVENING FOR OKZ004>048-050>052. WIND ADVISORY FROM NOON TODAY TO 7 PM CST THIS EVENING FOR OKZ004>042-044>046-050. TX...RED FLAG WARNING FROM NOON TODAY TO 7 PM CST THIS EVENING FOR TXZ083>090. WIND ADVISORY FROM NOON TODAY TO 7 PM CST THIS EVENING FOR TXZ083>090. && $$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
351 AM MST THU FEB 18 2016 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT ISSUED AT 351 AM MST THU FEB 18 2016 UPPER RIDGING SITS ACROSS THE CNTRL THIRD OF THE CONUS WITH THE MAIN AXIS NOW CROSSING THE DAKOTAS. A TROUGH/CUT OFF LOW IS CENTERED ALONG THE PAC NW COAST WITH A STRONG WAVE ROUNDING THE BASE ATTM. SWRLY LOW LEVEL FLOW HAS INCREASED OVER THE LAST FEW HOURS ACROSS NE WY AND THE NRN FOOTHILLS OF THE BLKHLS. OBS ALONG THE FOOTHILLS HAVE BEEN REPORTING VERY GUSTY WINDS WITH KSPF EVEN REACHING HIGH WIND WARNING CRITERIA BRIEFLY. THESE DOWNSLOPING WINDS HAVE RESULTED IN TEMPS RISING TO AROUND 60 DEGREES...WITH MANY OF THESE AREAS SEEING A 15 DEGREE JUMP WITHIN MINUTES. STRONG UPPER WAVE WILL QUICKLY PUSH ACROSS THE GREAT BASIN THIS MORNING...AND WYOMING THIS AFTERNOON. STRONG SWRLY FLOW WILL CONTINUE WITH INCREASING WARM AIR ADVECTION. THIS WILL MAKE FOR AN UNUSUALLY WARM DAY TODAY...WITH MANY LOCATIONS LIKELY BREAKING DAILY RECORD HIGHS. THE WAVE WILL BRING SOME SHOWERS TO THE AREA THIS EVENING...MAINLY ACROSS NE WY THROUGH THE BLKHLS AREA AND NW SD. HOWEVER WITH THE SPEED OF THE WAVE...THESE SHOWERS WILL QUICKLY PUSH THROUGH. WITH STEEP MIDLEVEL LAPSE RATES...COULD EVEN SEE A FEW LIGHTNING STRIKES. PRECIP WILL END LATE TONIGHT ACROSS THE AREA AS THE WAVE MOVES INTO THE MIDWEST. DRY WEATHER AND MOSTLY SUNNY SKIES ARE THEN EXPECTED FRIDAY...WITH HIGHS IN THE MID 50S TO MID 60S. THE CONCERN OF THE DAY WILL BE THE STRONG WINDS EXPECTED. SW WINDS AHEAD OF THE APPROACHING WAVE WILL INCREASE THIS MORNING ACROSS NE WY AND THE BLKHLS AREA THROUGH THE DAY...ESPECIALLY THIS AFTERNOON. FORECAST PROFILES AND THE LATEST HRRR SHOW GUSTS REACHING 50 TO 60 MPH MORE TOWARD THE AFTERNOON. HOWEVER SINCE THE NRN BLKHLS ALREADY HAS A HIGH WIND WARNING FOR DOWNSLOPING WINDS...WILL JUST EXTEND IT OUT. AS THE WAVE CROSSES THE ARE LATE THIS AFTERNOON INTO THE EVENING...A FAST MOVING COLD FRONT WILL PUSH ACROSS THE AREA. MODELS ARE SHOWING 50 TO EVEN 60 KT WINDS DEVELOPING WITHIN 5KFT OF THE SURFACE ACROSS NE WY AND MUCH OF WRN SD. SO WILL GO WITH A HIGH WIND WARNING FOR THE OVERNIGHT HOURS. THERE LOOKS TO BE A LITTLE BIT OF A LULL SETTING UP LATE TONIGHT SO WINDS COULD DROP TO BELOW CRITERIA...HOWEVER A SURFACE LOW CROSSING SRN CANADA FRIDAY WILL REINFORCE THE TIGHT PRESSURE GRADIENT. THIS WILL RESULT IN VERY STRONG WINDS AGAIN ACROSS THE AREA. WINDS WILL DECREASE FROM WEST TO EAST...SO THINK AREAS LIKE NE WY AND THE BLKHLS WILL SEE WARNING CRITERIA WINDS END BY MIDDAY FRIDAY...WHILE THE WRN SD PLAINS WILL CONTINUE TO SEE STRONG WINDS UNTIL LATE IN THE AFTERNOON. .LONG TERM...SATURDAY THROUGH WEDNESDAY ISSUED AT 351 AM MST THU FEB 18 2016 PROGRESSIVE UPPER FLOW FLOW WILL PERSIST INTO EARLY NEXT WEEK...WITH TRANSION TO AMPLIFIED WEST COAST RIDGE AND BROAD TROF FROM THE PLAINS TO THE GREAT LAKES FOR THE MIDDLE OF THE WEEK. DRY WEATHER AND ABOVE AVEARAGE TEMPERATURES EXPECTED FOR SUNDAY/MONDAY. AS FLOW BECOMES NORTHWESTERLY MID WEEK...ENSEMBLE MEMBERS SUGGEST MORE UNCERTAINTY WITH TEMPERATURES AS LOW LEVEL BAROCLINIC ZONE BACKS INTO FORECAST AREA. WITH LACK OF DECENT SHORTWAVES CROSSING THE AREA...WILL MAINTAIN DRY FORECAST. && .AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING ISSUED AT 351 AM MST THU FEB 18 2016 LIFR CIGS/VSBY WILL LINGER THROUGH THE MORNING ACROSS FAR NORTHWEST SOUTH DAKOTA...MAINLY ALONG THE NORTH DAKOTA BORDER. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH TODAY. GUSTY WEST-SOUTHWEST WINDS WILL OCCUR OVER PORTINOS OF NORTHEASTERN WYOMING AND THE BLACK HILLS. LOW LEVEL WIND SHEAR WILL CONTINUE FOR KRAP THROUGH MID MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT...WITH WIDESPREAD STRONG NORTHWEST WINDS. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...HIGH WIND WARNING UNTIL NOON MST FRIDAY FOR SDZ024. HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 PM MST FRIDAY FOR SDZ001-002-012>014-026-027-030>032-041>044-073-074. HIGH WIND WATCH FROM LATE TONIGHT THROUGH FRIDAY EVENING FOR SDZ046-047-049. HIGH WIND WARNING FROM 11 AM THIS MORNING TO NOON MST FRIDAY FOR SDZ028-029. HIGH WIND WARNING UNTIL 6 PM MST FRIDAY FOR SDZ025-072. WY...HIGH WIND WARNING UNTIL NOON MST FRIDAY FOR WYZ057. HIGH WIND WARNING FROM 11 AM THIS MORNING TO NOON MST FRIDAY FOR WYZ054>056-058-071. && $$ SHORT TERM...13 LONG TERM...7 AVIATION...7
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
534 AM CST THU FEB 18 2016 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 321 AM CST THU FEB 18 2016 SURFACE MAP SHOWS DEEP LOW PRESSURE MOVING EASTWARD OUT OF MONTANA WITH A WARM FRONT ARCHING THROUGH SD INTO EASTERN NE AND WESTERN MO. IR SATELLITE SHOWS A BAND OF ALTOSTRATUS IN ADVANCE OF THIS WARM FRONT COVERING ALL OF THE FORECAST AREA. COMBINATION OF CLOUD COVER AND LIGHT SOUTHEAST WINDFLOW KEEPING TEMPERATURES IN CHECK IN THE UPPER TEENS TO THE MIDDLE 20S AS OF 2 AM. SOUTHERLY FLOW PICKS UP TODAY INTO TONIGHT AS THE AREA OF LOW PRESSURE AND WARM FRONT APPROACH THE REGION. RAP BUFKIT SHOWS MOSTLY MID/HIGH CLOUD OVER THE AREA TODAY WITH STRATUS HOLDING OFF TO THE WEST...HOWEVER AS THE WARM FRONT APPROACHES THIS EVENING/OVERNIGHT... LOWEST 1.5KM OF COLUMN QUICKLY SATURATES LEADING TO WIDESPREAD STRATUS. LIFT/TURNING THROUGH THIS STRATUS WILL LEAD TO AREAS OF DRIZZLE WITH THE POSSIBILITY OF A LITTLE FREEZING DRIZZLE NORTH OF HIGHWAY 10 IN NORTH CENTRAL WI. ONLY LOOKS LIKE A 3-4 HOUR WINDOW AS TEMPERATURES WILL BE WARMING THROUGH THE NIGHT. LOOKS LIKE SHOWERS TAKE OVER WITH EVEN A CHANCE OF A RUMBLE OR TWO OF THUNDER IN THE 3-6AM TIME FRAME WITH 850MB MOISTURE TRANSPORT MAXIMIZING AND AS MID-LEVEL PV-ANOMALY/SURFACE LOW/COLD FRONT APPROACH FROM MN. WILL HAVE TO WATCH HIGH TEMPERATURES TODAY IN FILTERED SUNSHINE. HAVE MID 30S-LOWER 40S GOING NOW...BUT COULD END UP BEING A FEW DEGREES WARMER IF SUN FILTERS THROUGH ENOUGH. FRIDAY WILL SEE MAINLY MORNING TO EARLY AFTERNOON SHOWER CHANCES AS THE LOW AND COLD FRONT SWING THROUGH. THERE WILL ALSO BE A SLIGHT CHANCE OF A FEW MORNING THUNDERSTORMS AS WELL. OTHERWISE...LOOKS LIKE WE BREAK OUT IN ALMOST FULL SUNSHINE BY AFTERNOON WITH A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING LOW/COLD FRONT. THIS SHOULD ALLOW FOR DECENT MIXING. THIS LOOKS TO TAP SOME FAIRLY STRONG WINDS WITH NAM/GFS BUFKIT SHOWING 40-50KT ONLY 0.5KM AGL. RIGHT NOW...LOOKING LIKE SUSTAINED WESTERLY WINDS OF 20-30MPH WITH GUSTS 35 TO 40 MPH...POSSIBLY CLOSING IN ON 50 MPH IN THE MORE WIND PRONE AREAS OF NORTHEAST IA/SOUTHEAST MN AND HIGHER TERRAIN/BLUFF TOPS ALONG THE MISSISSIPPI RIVER. LOOKING LIKELY WE WILL EVENTUALLY NEED A WIND ADVISORY HEADLINE BASED ON THIS. OTHERWISE...A COLD FRONT PASSED THROUGH...MIXING OF PLAINS DOWNSLOPED AIR BEHIND THIS SYSTEM SHOULD PUSH HIGHS WELL INTO THE 40S WITH A FEW LOWER 50S ACROSS NORTHEAST IA INTO SOUTHWEST WI. STRATUS CLOUDS FILL BACK IN FROM NORTHWEST TO SOUTHEAST INTO THE AREA FRIDAY NIGHT BUT REMAINING RELATIVELY MILD WITH LOWS ONLY FALLING INTO THE LOWER/MIDDLE 30S. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 321 AM CST THU FEB 18 2016 HIGH ZONAL FLOW ACROSS THE NORTHERN CONUS FOR SATURDAY INTO SUNDAY. THIS USHERS IN A WEAK MID-LEVEL TROUGH WITH A SMALL CHANCE OF SNOW LATE SATURDAY NIGHT AND MOSTLY RAIN CHANCES SUNDAY AS TEMPERATURES WARM INTO THE MIDDLE 30S TO LOWER 40S. MONDAY THROUGH WEDNESDAY LOOKING DRY AND A BIT COOLER/BACK TO NEAR NORMAL AS UPPER LEVEL TROUGHING CARVES INTO THE CENTRAL CONUS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 534 AM CST THU FEB 18 2016 PRIMARILY VFR CONDITIONS EXPECTED THROUGH THE DAY...THOUGH WITH PERHAPS A TOUCH OF LIGHT FOG WORKING INTO KRST AS MOISTURE INCREASES OVER THE SNOW PACK. AN APPROACHING WARM FRONT SHOULD BRING QUICK DEVELOPMENT OF STRATUS AND PROBABLY SOME DRIZZLE THIS EVENING AND TONIGHT...THOUGH THERE REMAINS SOME QUESTION ABOUT HOW LONG THOSE CLOUDS WILL STICK AROUND...AS WINDS JUST ABOVE THE SURFACE REMAIN VERY STRONG. SOME OF THE LATEST TRENDS SUGGEST STRATUS MAY PUSH NORTH OF THE TAF SITES BY 06Z...ONLY TO RETURN TOWARD 12Z IN ADVANCE OF AN APPROACHING COLD FRONT. FOR NOW...GIVEN THE PATTERN WITH LOTS OF MOISTURE RUNNING UP OVER THE COLDER GROUND/SNOW...HAVE TO BELIEVE STRATUS WILL PROVE TOUGH TO COMPLETELY DISLODGE...BUT SOMETHING TO WATCH CLOSELY THROUGH THE DAY. WINDS WILL RAMP UP FROM THE SOUTHEAST TODAY...WITH LOW LEVEL WIND SHEAR A CONCERN TONIGHT...PARTICULARLY FOR KLSE. && .HYDROLOGY... ISSUED AT 321 AM CST THU FEB 18 2016 WITH CLIMBING TEMPERATURES INTO THE WEEKEND...SIGNIFICANT SNOW MELT WILL TAKE PLACE...MELTING A 1-2 INCH WATER EQUIVALENT SNOWPACK WHICH WILL ENTER THE RIVERS. A FEW MODELS SHOWING A COMPLETE MELT OF THIS SNOWPACK. AS A RESULT...EXPECT RIVER RISES AND THE POSSIBILITY OF ICE BREAKUP ON STREAMS/RIVERS. A FEW ICE JAMS COULD RESULT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...LAWRENCE HYDROLOGY...DAS
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
403 PM EST THU FEB 18 2016 .SYNOPSIS... 20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFIED UPPER LEVEL PATTERN IN PLACE. LOOKING FROM WEST TO EAST WE FIND A POTENT UPPER LEVEL LOW/TROUGH NOW ONSHORE ALONG THE PACIFIC COAST...WITH A STRONG UPPER JET SPREADING OVER THE INTERMOUNTAIN WEST. THIS STRONG JET FURTHER DOWNSTREAM BUILDS A LARGE RIDGE THROUGH THE CENTRAL PORTION OF THE CONUS BEFORE DIVING BACK TO THE SOUTH INTO LONGWAVE TROUGHING CONTINUING TO EXIT INTO THE WESTERN ATLANTIC. CLOSER TO HOME...THE FLORIDA PENINSULA RESIDES ON THE BACKSIDE OF THIS DEPARTING LONGWAVE TROUGH WITH DEEP LAYER SUBSIDENCE IN PLACE AND SLOWLY BUILDING HEIGHTS ALOFT. THESE BUILDING HEIGHTS WILL ENSURE OUR SENSIBLE WEATHER REMAINS DRY THROUGH THE UPCOMING WEEKEND. 18/12Z KTBW SOUNDING PROFILE SHOWED A VERY DRY COLUMN OVER OUR HEADS WITH A DEFINED SUBSIDENCE INVERSION LOCATED AROUND 850MB. FORECAST SOUNDING AND TIME-HEIGHT ANALYSIS SUGGEST THIS VERY DRY AIR WILL REMAIN IN PLACE THROUGH FRIDAY...AND LITTLE IN THE WAY OF FORCING FOR LIFT...OUR SKIES WILL REMAIN MOSTLY CLEAR. AT THE SURFACE...THE FLORIDA PENINSULA IS UNDER CONTROL OF A RIDGE OF HIGH PRESSURE THAT EXPANDS ALL THE WAY SOUTH FROM A CENTER OVER THE OHIO VALLEY/NE STATES. THIS RIDGE IS PROVIDING THE REGION WITH A GENERAL NORTHEASTERLY FLOW PATTERN. && .SHORT TERM (TONIGHT THROUGH FRIDAY)... FAIR...DRY...AND SEASONABLE WEATHER WILL CONTINUE THIS EVENING... TONIGHT...AND INTO FRIDAY. THE DRY AIR AND CLEAR SKIES IN PLACE WILL HELP TEMPERATURES COOL DOWN OVERNIGHT. BY SUNRISE LOOKING FOR LOWS IN THE LOWER/MID 40S FAR NORTH...TO THE UPPER 40S/LOWER 50S THROUGH THE I-4 CORRIDOR...AND MIDDLE 50S DOWN THROUGH FORT MYERS. MIDDLE 50S WILL ALSO BE FOUND ACROSS SOUTHERN PINELLAS COUNTY WITH THE FLOW OFF THE WATERS OF TAMPA BAY. TEMPERATURES ON FRIDAY WILL RISE QUICKLY AFTER THE COOL START...REACHING THE LOWER TO MIDDLE 70S ALMOST REGION-WIDE UNDER MOSTLY/PARTLY SUNNY SKIES. ONLY SAY PARTLY SUNNY ABOVE AS WE MAY SEE A FEW-SCT CUMULUS FIELD DURING THE AFTERNOON AS SOME LOWER LEVEL MOISTURE UNDER 850MB ARRIVES ON THE EASTERLY FLOW FROM THE ATLANTIC. LATE IN THE AFTERNOON WE ARE LIKELY TO MIX PAST THIS MOISTURE LEVEL...WHICH WILL DISSIPATE THIS CUMULUS FIELD. ...AND MORE OF THE SAME FOR THE UPCOMING WEEKEND. && .LONG TERM (FRIDAY NIGHT-THURSDAY)... FLOW ALOFT WILL REMAIN ZONAL THROUGH THE WEEKEND WITH SURFACE HIGH PRESSURE OVER THE WESTERN ATLANTIC EXTENDING OVER THE FLORIDA PENINSULA. THIS SET-UP WILL LEND A NICE WEEKEND WITH TEMPERATURES WARMING INTO THE 70S EACH AFTERNOON. FLOW AROUND THE HIGH WILL KEEP EASTERLY WINDS IN PLACE BOTH DAYS. DRIER AIR WILL KEEP RAIN OUT OF THE FORECAST...ALTHOUGH THE ATMOSPHERE WILL MOISTEN A BIT FOR SUNDAY...BUT THAT WILL LIKELY ONLY LEAD TO A FEW MORE CLOUDS SUNDAY THAN SATURDAY. THE PATTERN BEGINS TO AMPLIFY EARLY NEXT WEEK AS SHORTWAVE ENERGY DROPS SOUTHWARD INTO THE SOUTH-CENTRAL PART OF THE COUNTRY. AT THE SURFACE...GLOBAL MODELS ARE STILL SHOWING A SURFACE LOW FORMING OVER THE SOUTHEAST REGION...BUT LOCATION AND TIMING CONTINUES TO CHANGE FROM RUN TO RUN. THE FORECAST FOR NOW TO SHOW THE HIGHEST RAIN CHANCES TUESDAY INTO THE FIRST PART OF WEDNESDAY. THE UPPER TROUGH WILL SWING EASTWARD WEDNESDAY AND THURSDAY...AS THE SURFACE LOW MOVES QUICKLY NORTHEAST AND THE ASSOCIATED COLD FRONT CLEARS OUR CWA BY WEDNESDAY EVENING. THIS WILL BRING AN END TO THE RAIN WITH HIGH PRESSURE BUILDING INTO THE AREA FOR THE END OF THE WEEK. && .AVIATION... VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WINDS SHIFTING FROM NORTHEAST TODAY TO EASTERLY FRIDAY. && .MARINE... HIGH PRESSURE CENTERED OVER THE OHIO VALLEY WILL DRIFT SOUTHEAST TOWARD THE CAROLINAS BY FRIDAY...AND INTO THE WESTERN ATLANTIC THIS WEEKEND. THIS RIDGE WILL REMAIN IN CONTROL OF THE FORECAST WATERS WITH WINDS SHIFTING FROM NORTHEAST TO EAST THROUGH THE PERIOD. WINDS ARE EXPECTED TO QUICKLY RAMP BACK UP TO CAUTIONARY LEVELS THIS EVENING AND THROUGH THE OVERNIGHT. THERE IS SOME POTENTIAL THAT THE WINDS MAY REACH A PERIOD OF ADVISORY LEVEL WINDS TONIGHT AS WELL. WINDS WILL ONCE AGAIN SUBSIDE DURING THE DAY FRIDAY...AND THEN GENERALLY REMAIN BELOW HEADLINE CRITERIA THROUGH THE WEEKEND AS THE RIDGE CENTER MOVES CLOSER TO THE REGION. && .FIRE WEATHER... HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION KEEPING OUR WEATHER FAIR...DRY...AND SEASONABLE THROUGH THE UPCOMING WEEKEND. JUST ENOUGH LOW LEVEL MOISTURE FROM THE ATLANTIC WILL BE ARRIVING ON EASTERLY FLOW TO PREVENT CRITICAL LEVELS OF RELATIVE HUMIDITY... AND PREVENTING RED FLAG CONDITIONS FROM BEING ACHIEVED. FOG POTENTIAL... NO SIGNIFICANT FOG IS EXPECTED THROUGH FRIDAY NIGHT. && .PRELIMINARY POINT TEMPS/POPS... TPA 52 73 56 75 / 0 0 0 0 FMY 55 75 55 76 / 0 0 10 0 GIF 52 73 53 75 / 0 0 10 0 SRQ 54 74 54 74 / 0 0 0 0 BKV 47 74 48 76 / 0 0 0 0 SPG 54 72 58 73 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA LONG TERM/DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
254 PM CST THU FEB 18 2016 .SHORT TERM...(Tonight) ISSUED AT 253 PM CST THU FEB 18 2016 Southeast winds gusting over 30 mph at times this afternoon, helping to boost temperatures well into the 40s. Have seen some 50 degree readings west of Springfield early this afternoon and 60s are fairly widespread across central and western Missouri. Not looking for much of a drop off in temperatures tonight, with steady or rising temperatures from about 9 pm onward. Low level jet really ramps up during the evening, with the RAP mode forecasting 2000 foot winds of 60-65 knots this evening and around 70 knots after midnight over the southeast third of the forecast area. This will help keep the wind gusts up and will go with gusts 30-35 mph in most areas north of I-70. Stream of mid/high clouds will continue to affect primarily the northern half of the forecast area tonight, with some increase over the remainder of the area late tonight as the cold front approaches. && .LONG TERM...(Friday through Thursday) ISSUED AT 253 PM CST THU FEB 18 2016 High pressure to the east, combined with a low pressure area to the northeast will tighten the gradient considerably, and along with the very warm air, will bring much stronger winds into the region than this afternoon. Southwest winds in the morning are expected to increase with sustained winds between 25 and 30 mph, with gusts of near 40mph. These strong winds will continue into the afternoon, but begin to taper off late afternoon after the dry trough moves through and winds switch to more west-southwest. However, will keep the advisory going through 00z tomorrow. Wind Advisory will be for the whole area as well. Once this trough comes through Friday, zonal flow will control the area through the weekend. Another low pressure area will develop in the south and move toward the area for the weekend. Models differ on how far north the low pressure area gets, with the ECMWF furthest north. GFS and NAM are furthest south and therefore much drier over the CWA. However, going forecast for now is pcpn across the CWA Sat night and then just in the southeast for Sunday. With model uncertainty still, will keep forecast as is for now...which does include likely pops in the southeast Sat night. Temps will start out very warm tomorrow and should continue into Sat ahead of the pcpn. Then temps cool as clouds and pcpn move through the area Sunday. Temps next three days will be very above normal. Extended period looks to be very dry as flow remains somewhat zonal through the middle of next week. Extended models have some disagreement on chances of pcpn Wed night and Thur, but best to keep things dry for now until models work things out. Temps will be cooler than this weekend, but still be slightly above normal. Temps will be warmer early in the extended, then decrease some toward the end of the week. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 1135 AM CST THU FEB 18 2016 Main concern will be with the gusty winds over the next 24 hours. Already seeing gusts over 25 knots from about KPIA-KSPI westward, and the gusty winds will spread to KCMI this afternoon. Have maintained the mention of LLWS tonight, as the RAP model continues to show a low level jet of 60-70 knots at 2000 feet spreading into the area. Main cold front is expected to reach western Illinois by late Friday morning, with some of this jet mixing down to provide south-southwest wind gusts of 30-35 knots. Currently appears the front should be dry, but some ceilings may approach MVFR levels near KPIA/KBMI Friday morning. && .ILX Watches/Warnings/Advisories... Wind Advisory from 6 AM to 6 PM CST Friday for ILZ027>031- 036>038-040>057-061>063-066>068-071>073. && $$ SHORT TERM...Geelhart LONG TERM...Auten AVIATION...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1137 AM CST THU FEB 18 2016 .UPDATE... ISSUED AT 935 AM CST THU FEB 18 2016 Winds starting to pick up, with gusts 20-25 mph across the west half of the forecast area. This has helped temperatures rise a bit ahead of the curve, so have done some tweaks of the hourly trends into the afternoon. No substantial changes to the highs were made, with filtered sunshine allowing temperatures to reach the 50s across at least the southwest half of the forecast area. && .SHORT TERM...(Today) ISSUED AT 311 AM CST THU FEB 18 2016 Sprawling ridge of high pressure extending from the eastern Great Lakes to the Gulf States will shift eastward toward the East Coast later today. Meanwhile, a trough of low pressure will sharpen in the lee of the Rockies. The pressure gradient between these two features will tighten as the day progresses, leading to strong/gusty winds across central Illinois. Forecast soundings indicate sustained southeasterly winds of 15 to 25 mph with gusts to around 35 mph by mid to late afternoon. Skies will remain partly to mostly cloudy as a warm front develops across Nebraska into Missouri. Due to the cloud cover and a distinct easterly component to the wind, have not gone quite as warm as some of the numeric guidance would suggest. Have therefore kept afternoon high temperatures in the middle to upper 40s...with a few lower 50s across the far SW KILX CWA. .LONG TERM...(Tonight through Wednesday) ISSUED AT 311 AM CST THU FEB 18 2016 As a warm front lifts slowly northward through the area tonight, winds will gradually become southerly. Strong winds gusting to between 30 and 35 mph will continue, helping temperatures steadily rise through the night. Readings will start out in the 40s during the early evening, then will climb into the lower 50s by dawn Friday. NAM continues to show a very strong 70-80mph 925mb jet streak developing from the Ozarks northeastward into Indiana by 12z Fri. Once the sun rises, some of this high momentum air will mix to the surface, creating wind gusts in the 45 to 50 mph range along/east of the I-57 corridor. Further west, gusts to between 40 and 45 mph will be common. As a result, a Wind Advisory will likely be needed Friday morning over much of the area, but particularly the E/SE CWA. The winds will gradually decrease by Friday afternoon after a weak cold front sweeps through the region. The front will settle southward into the Ohio River Valley where it will become parallel to the upper flow and stall during the day Saturday. As has been advertised for the past few days, an upper wave will eject eastward through the Plains, interacting with the boundary to produce a period of rain Saturday night into Sunday morning. 00z Feb 18 models have come into relatively good agreement concerning the strength and timing of the associated low, with the NAM/GFS/GEM all taking it across southern Illinois late Saturday night. Meanwhile, the ECMWF features a further north track along/north of the I-70 corridor. This represents a shift from its previous runs, so have tossed it out in favor of the model consensus. Bottom line will mean rain showers developing everywhere Saturday night, with the highest PoPs concentrated south of the I-72 corridor. GFS forecast soundings show modest elevated instability developing across the southern CWA, with MUCAPE values of around 200 J/kg. Have therefore added isolated thunderstorms to the forecast along/south of a Paris to Taylorville line. Once the low pushes into Indiana, any lingering showers will come to an end from west to east across the area on Sunday. Mild temperatures in the 50s will persist. After that, several waves will drop southward out of Canada, gradually carving a long-wave trough across the eastern CONUS next week. End result will be slowly falling temps each day, with readings dropping back to near normal in the lower to middle 40s Monday through Wednesday. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 1135 AM CST THU FEB 18 2016 Main concern will be with the gusty winds over the next 24 hours. Already seeing gusts over 25 knots from about KPIA-KSPI westward, and the gusty winds will spread to KCMI this afternoon. Have maintained the mention of LLWS tonight, as the RAP model continues to show a low level jet of 60-70 knots at 2000 feet spreading into the area. Main cold front is expected to reach western Illinois by late Friday morning, with some of this jet mixing down to provide south-southwest wind gusts of 30-35 knots. Currently appears the front should be dry, but some ceilings may approach MVFR levels near KPIA/KBMI Friday morning. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Geelhart SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
242 PM CST THU FEB 18 2016 ...Updated Short term, Long term, and Fire weather discussions... .SHORT TERM...(THIS EVENING THROUGH Friday) ISSUED AT 239 PM CST THU FEB 18 2016 A cold front will move into southwest Kansas overnight as an upper level disturbance crosses the Northern Plains. This surface boundary will briefly stall out in southwest Kansas on Friday as a subtle upper level disturbance moves into the four corners region by late day. Models are in good agreement with some cooler air returning to western Kansas on Friday with the 850mb temperatures from the GFS and NAM indicating around a 10C drop from 00z Friday to 00z Saturday. Based on this and some high clouds during the afternoon the previous forecast still looks on track with highs ranging from the mid 60s in north central Kansas to around 70 along the Oklahoma border. .LONG TERM...(Friday NIGHT THROUGH Thursday) ISSUED AT 239 PM CST THU FEB 18 2016 The next in a series of upper level troughs will be crossing the plains over the weekend period. As this next upper level system passes...another cold front will cross southwest Kansas early Sunday. This weekend cold front will allow for some cooler, more seasonal, air to return to western Kansas as the surface boundary moves into northern Texas. Based on the cooling that is forecast to occur Saturday night and Sunday from the GFS and ECMWF it currently appears that highs will fall from the upper 60s to lower 70s on Saturday to the mid to upper 50s on Sunday. Another upper level disturbance will approach western Kansas early next week. As this next upper level system approaches southwest Kansas late Monday into Tuesday there will be improving lift developing across southwest Kansas based on the location of the upper level jet and 850mb warm air advection. This will give rise to increasing clouds which will keep temperatures on the cool side Monday and Tuesday. There may even be a chance for some light precipitation across portions of western and north central Kansas. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON) ISSUED AT 1121 AM CST THU FEB 18 2016 RAP and NAM mean mixed layer winds this afternoon continue to indicated gusty southwest winds continue at around 25 knots through at least 21z Thursday. These winds will then fall back to around 20 knots by 00z Friday and then fall back to into the 10 to 15 knot range after 06z Friday. The southwest winds will also be gradually veering to the northwest after midnight as a weak surface cold front crosses western Kansas. VFR conditions are expected over the next 24 hours based on NAM BUFR soundings along with the RAP and HRRR. && .FIRE WEATHER... ISSUED AT 239 PM CST THU FEB 18 2016 For this evening...the strong southwest winds will begin to gradually subside towards sunset. Wind speeds should begin to fall back into the 15 to 20 knots by 8pm. Along with the decreasing winds the relative humidity values will begin to rise as temperatures fall. At this time the relative humidity values will still be around 15 percent through 9 pm in some locations west of highway 283, however given the decreasing winds will not extend the Red Flag Warning past 8 pm at this time. Friday the afternoon relative humidity values will once again fall into the teens with the lower relative humidity values being located west of highway 283. Wind speeds however Friday afternoon will not be strong enough to support issuing a red flag warning, however elevated fire weather conditions are expected and out door burning on Friday is not recommended. && .PRELIMINARY POINT TEMPS/POPS... DDC 46 69 38 69 / 0 0 0 0 GCK 42 68 35 69 / 0 0 0 0 EHA 45 71 40 71 / 0 0 0 0 LBL 44 70 36 71 / 0 0 0 0 HYS 47 68 36 67 / 0 0 0 0 P28 53 71 43 71 / 0 0 0 10 && .DDC Watches/Warnings/Advisories... Red Flag Warning until 8 PM CST /7 PM MST/ this evening for KSZ030-031-043>046-061>066-074>081-084>090. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Burgert FIRE WEATHER...Burgert
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1128 AM CST THU FEB 18 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 323 AM CST THU FEB 18 2016 High clouds on water vapor imagery were noted lifting over the upper ridge building into the western high plains this morning. A broad and strong upper trough entering the Pac NW was streaming steady moisture off the southern CA coast towards the southwest Conus. Sfc Observations showed the developing lee trough across eastern CO inducing southerly winds to increase between 10 and 15 mph. Low level moisture across southern TX was quickly advecting northward with a strong 50+ kt low level jet ongoing and anticipated to increase after sunrise. This low level moisture advection is a major factor as to how low RH readings fall during the late afternoon as a stout dryline mixes eastward across KS. Fire weather details follow below on the current thinking. Forecast was based on a combination of the RAP and HRRR (previous and current runs) with the low 40 degree dewpoints and highs in the lower 70s for east central/north central areas. North central KS may be able to mix out to the upper 70s as forecast soundings are consistent in the warm inversion layer reaching the sfc in addition to the drier air. Wind speeds are also of concern with speeds expected to increase shortly after sunrise between 25 and 35 mph sustained with gusts between 40 and 50 mph possible. For this reason, have expanded the wind advisory for areas generally along and south of Interstate 70. For tonight, winds are expected to stay up between 15 and 25 mph sustained as they veer to the west with the upper trough crossing over Nebraska. High clouds increase while temps stay mild in the lower 50s. .LONG TERM...(Friday through Wednesday) Issued at 323 AM CST THU FEB 18 2016 A quasi zonal pattern sets up for Friday and through the weekend with the bulk of energy passing to the north of the forecast area. Models continue to show low level moisture advection into east central KS for Saturday and Saturday night as a subtle piece of energy passes across the state. Both the NAM and GFS suggest there will be little to no instability however and model progs of 850 winds remain rather light for this time of year. Nevertheless there has been a persistent signal from the models for the possibility for showers and thunderstorms so have maintained a small chance POP for Saturday afternoon and Saturday evening. By Sunday morning, a cold front is expected to push south of the forecast area with dry air moving in. This should bring and end to the precip changes as well as cooler temps for Sunday. Temps for Friday and Saturday should remain well above normal. Forecast soundings show the boundary layer mixing fairly deeply on Friday but also bring in some cooler temps at 850 MB such that adiabatic mixing would only support highs in the mid and upper 60s. Because of this have shaved a degree or two off the highs from the prev forecast. The airmass stays pretty similar for Saturday. The one wild car is possible low clouds moving into eastern KS and limiting insolation. For now have continued with highs in the mid and upper 60s for Saturday. For next week, the models are suggesting the pattern becomes more amplified with a return to northwest flow for the central plains. However there are differences in how the pattern sets up and where week waves within the flow move. Its plausible that there could be some light precip with these passing waves, similar to what we experienced earlier this week. However low confidence in the small scale features preclude a mention of precip chances at this time. With the return of northwest flow, models bring the occasional ridge of high pressure through the plains. This is expected to keep temps cooler with highs in the 50s and lows around freezing next week. && .AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon) Issued at 1104 AM CST THU FEB 18 2016 VFR conditions are expected through the period. Winds will remain strong through evening with sustained winds near 20-25 knots and gusts 35-40+ knots. Winds will decrease to 15-20 with gusts 25-30 knots. LLWS is anticipated overnight as LLJ will increase to near 70 knots. However, if BL continues to mix overnight, gusts may approach 40 knots. Winds will also veer to WNW overnight as a cold front moves across the area. && .FIRE WEATHER... Issued at 323 AM CST THU FEB 18 2016 High resolution guidance is still struggling on dewpoints during the afternoon as it appears to still overestimate the amount of moisture advection from the southwest while underestimating the depth of vertical mixing in regards to the drier air aloft. Forecast was collaborated to side closer to the RAP and HRRR solutions which represent an even compromise of RH values falling to the low and middle 30 percent range for most of the area. Most uncertain area is across north central Kansas where stronger mixing aloft and from the dryline may help realize RH values dropping sharply towards the upper teen to lower 20 percent range during the late afternoon. Regardless of the RH values being borderline, winds sustained at 25 to 35 mph with gusts in upwards of 45 to 50 mph will easily promote uncontrolled fire growth given the critical fuels reported. Therefore have upgraded the watch to a Red Flag Warning in effect at 11 AM until 6 PM this evening for the entire area. Uncertainty increases for this evening as RH values rise. Winds remain strong however so any fire that forms during the afternoon will remain uncontrollable overnight. Have maintained the watch overnight for the next shift to review. For Friday, dry air is still expected to overspread the forecast area with min RH values falling to around 20 percent during the afternoon. However models show the pressure gradient relaxing pretty quickly in the morning Friday and wind speeds are forecast to be quite a bit lighter. There remains the possibility to see some gusts around 20 MPH especially across northern KS where the gradient will be slower to relax. But the overall trend in the models has been for weaker winds. Will keep the fire weather watch in tact for now because of the dry air, but there is a real possibility that conditions will not make it to red flag on Friday. && .TOP Watches/Warnings/Advisories... Red Flag Warning until 7 PM CST this evening for KSZ008>012- 020>024-026-034>040-054>056-058-059. Fire Weather Watch from 7 PM CST this evening through Friday afternoon for KSZ008>012-020>024-026-034>040-054>056-058-059. Wind Advisory until 7 PM CST this evening for KSZ021>024-026- 034>040-054>056-058-059. && $$ SHORT TERM...Bowen LONG TERM...Wolters AVIATION...Baerg FIRE WEATHER...Bowen/Wolters
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1122 AM CST THU FEB 18 2016 ...Updated Synopsis and Aviation discussion... .SYNOPSIS... ISSUED AT 1121 AM CST THU FEB 18 2016 At 12z Thursday a 500mb trough was located along the coast of the Pacific Northwest and an upper level ridge axis extended from Texas to North Dakota. 700mb temperatures ranged from +6 at Rapid City to +9 at Amarillo. The 850mb temperature at 12z Thursday at Dodge City was 21C with a southwest wind at 50knots. At the surface a dryline extended from northwest Kansas to the Texas Panhandle. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CST THU FEB 18 2016 Heat in February?! Yes. The atmosphere recognizes no calendar. Break out the shorts and flip flops and turn on that AC because it is going to be very hot today. Records will likely be annihilated. See the section below for values. The main concern today was temperatures. Most of the temperature grid looked on track, however, some of the models aren`t mixing out the eastern zones, which may explain the lower values. Feel this might not be that accurate as there is a tremendous amount of synoptic southwesterly momentum. The models are overdoing boundary layer moisture as well. Early morning observations across OK/TX show this is a poor initialization. Bottom line, 80s for everyone. Another HUGE concern is fire weather. See the section below for more details. .LONG TERM...(Friday THROUGH Wednesday) ISSUED AT 333 AM CST THU FEB 18 2016 The heat won`t last too long. A cold front will move across the region with much cooler 850-hPa temperatures in its wake. The atmosphere will be fairly dry, so think it will warm up quickly with upper 60s north to lower 70s south for Friday. Downslope flow continues with pleasant temperatures again for Saturday. By Sunday, cold air advection will set in and put temperatures back closer to normal - 50s with a few 60F readings near the OK border. Monday and Tuesday look to be fairly seasonal with highs in the lower 50s. The models shows a wave moving through on Tuesday, which may bring light precipitation to the western forecast area. There isn`t good moisture advection with this system so the lower end superblend pops look fine for now. Beyond that, we go into a dry pattern with northwest flow aloft and a drier boundary layer. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON) ISSUED AT 1121 AM CST THU FEB 18 2016 RAP and NAM mean mixed layer winds this afternoon continue to indicated gusty southwest winds continue at around 25 knots through at least 21z Thursday. These winds will then fall back to around 20 knots by 00z Friday and then fall back to into the 10 to 15 knot range after 06z Friday. The southwest winds will also be gradually veering to the northwest after midnight as a weak surface cold front crosses western Kansas. VFR conditions are expected over the next 24 hours based on NAM BUFR soundings along with the RAP and HRRR. && .FIRE WEATHER... ISSUED AT 333 AM CST THU FEB 18 2016 ** A very volatile fire weather day. Outdoor burning should not be attempted at all as environmental conditions are favorable for explosive fire growth. ** For the meteorology, the main concern was for today is dewpoints and winds. Observations as well as BOIVerify shows a clear high bias in dewpoints in the NWP fields. Examining forecast skew-t/log-p`s shows what appears to be an unrealistic moisture advection signal in the boundary layer. Current early morning observations show that the model dewpoints are off, particularly in some of the mesoscale models like the NAM. Have decided to expand the RFW for the entire county warning forecast area. The WFO neighbor to the east uses a different threshold for RFW criteria than we do (GFDI versus RH`s) and that explained the previous gap. The RH`s will be a bit more marginal across south-central Kansas, but felt it was better to fill in the gap rather than have a split due to different WFO hazard warning thresholds. Also question the mixing in some of the models, which does not mix out the eastern CWA. This seems more unrealistic than not as there is tremendous amount of southwesterly momentum and mixing with the synoptic wave. Pattern recognition clearly suggests a late Winter/weak dryline event. Added a buffer to the end of the warning as well, as hazard conditions may still exist longer than previously thought. Bottom line, do not burn today. The fire will become quickly out of control. && .CLIMATE... ISSUED AT 333 AM CST THU FEB 18 2016 Record highs will likely be smashed today. Location...Forecast high...Record...Record year. Dodge City...84...77...1986 Garden City...85...81...1986 Liberal...86...83...1983 Pratt...82...82...1981 Syracuse...85...79...1986 && .PRELIMINARY POINT TEMPS/POPS... DDC 85 45 69 36 / 0 0 0 0 GCK 86 41 68 33 / 0 0 0 0 EHA 85 44 71 38 / 0 0 0 0 LBL 85 44 70 35 / 0 0 0 0 HYS 87 45 67 34 / 0 0 0 0 P28 81 51 71 40 / 0 0 0 0 && .DDC Watches/Warnings/Advisories... Red Flag Warning until 8 PM CST /7 PM MST/ this evening for KSZ030-031-043>046-061>066-074>081-084>090. && $$ SYNOPSIS...Burgert SHORT TERM...Sugden LONG TERM...Sugden AVIATION...Burgert FIRE WEATHER...Sugden CLIMATE...Sugden
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1017 AM MST THU FEB 18 2016 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 322 AM MST THU FEB 18 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW RIDGE IN PLACE ACROSS THE CENTRAL US...WITH A STRONG UPPER LOW OFF THE PACIFIC NW COAST. 130-145 KT 300MB JET WAS OBSERVED OVER CALIFORNIA ON 00Z RAOBS AND ON WV THIS CAN BE SEE AS STRONG AREA OF CLEARING NOSING INTO DIFFLUENT REGION BETWEEN RIDING AND UPPER LOW. DEEP SW FLOW IS IN PLACE ACROSS THE CENTRAL ROCKIES WITH PLUME OF THICK HIGH CLOUD COVER STREAMING INTO THE PLAINS. AT THE SURFACE...LOW PRESSURE IS IN PLACE OVER EASTERN COLORADO WITH DRY LINE APPROXIMATELY FROM LAMAR COLORADO SOUTH. FOCUS ON THIS FORECAST PERIOD IS ON FIRE WEATHER TODAY AND A POSSIBLE HIGH WIND EVENT TONIGHT. SEE FIRE WEATHER SECTION REGARDING UPDATES ON RFW. TODAY...VERY WARM AIR MASS WILL BE IN PLACE TODAY WITH DEEP SW FLOW ALOFT AND WAA ALONG/EAST OF SURFACE LOW. CIRRUS IS ALREADY CONSIDERABLY MORE EXTENSIVE IN COVERAGE THAN MODELS WOULD INDICATE AND SATELLITE TRENDS GENERALLY SUPPORT THIS TREND CONTINUING. THIS COMPLICATES OUR HIGH TEMP FORECAST AND POTENTIAL MIXING HEIGHTS FOR WIND/TDS. WITH SURFACE LOW SHIFTING TOWARD THE NORTHERN HALF OF OUR CWA AHEAD OF APPROACHING COLD FRONT WILL RESULT IN STRONGEST SURFACE GRADIENT REMAINING EAST THROUGH THE DAY. BETTER MIXING WOULD STILL ALLOW FOR GUSTS IN THE 40-45 MPH RANGE TODAY...HOWEVER DUE TO THE CIRRUS THESE STRONGER GUSTS MAY NOT BE REALIZED THIS AFTERNOON. I LEANED TOWARD THE "COOLER" END OF GUIDANCE FOR HIGHS...WHICH STILL SUPPORTS DAILY RECORDS AT MOST LOCATIONS (UPPER 70S/NEAR 80). IF WE CAN SEE GOOD BREAKS AND LESS OPAQUE CLOUD COVER WE MAY BE LOOKING AT MONTHLY RECORDS. TONIGHT...UPPER LOW MOVES FROM PACIFIC NORTHWEST ACROSS NORTHERN PLAINS WITH NEGATIVELY TILTED OPEN WAVE ACROSS NORTHERN NEBRASKA TONIGHT. THE ASSOCIATED COLD FRONT WILL DROP SOUTH ACROSS OUR CWA AROUND 06Z. MODELS SHOW A VERY STRONG LLJ DEVELOPING OVER OUR CWA WITH H85 WINDS 60KT OR HIGHER. GFS IS THE STRONGEST ON BL WINDS...AND MAY BE RUNNING HIGH AS THE STRONG FRONTAL INVERSION (AIDED BY RADIATIONAL COOLING) COULD LIMIT MIXING. 3HR PRESSURE RISES 8-10 MB BEHIND THIS FRONT WILL SUPPORT WINDY CONDITIONS...I AM JUST NOT AS CONFIDENT THAT THE STRONGEST WINDS ALOFT WILL MAKE IT TO THE SURFACE. LOCATIONS FURTHER NORTH WILL BE AIDED BY STRONG SUBSIDENCE BEHIND TROUGH AXIS (HIGHLIGHTED BY STRONG PV ANOMALY ON DYNAMIC TROPOPAUSE FIELD). THIS TYPE OF PATTERN TENDS TO BE SHORT LIVED IN NATURE WITH STRONGEST GUSTS OVER SHORTER TIME SPANS. I INCREASED WIND GUSTS ACROSS THE NORTHERN HALF OF OUR CWA TO INCLUDE GUSTS 50-55 MPH TONIGHT...BUT DECIDED AGAINST HIGH WIND WATCH ISSUANCE DUE TO UNCERTAINTY REGARDING NIGHTTIME MIXING OVER OUR CWA. FRIDAY-SATURDAY...WESTERLY FLOW WILL BE IN PLACE THROUGH THESE PERIOD WITH DEEP DRY AIR AND ABOVE NORMAL TEMPS. HIGHS SHOULD BE 10 TO 15 DEGREES COOLER AFTER THE FROPA TONIGHT...HOWEVER THEY WILL STILL BE IN THE 60S ACROSS OUR CWA (15-20F ABOVE NORMAL). .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 147 AM MST THU FEB 18 2016 UPPER FLOW WILL BE WESTERLY SUNDAY AND MONDAY FOLLOWED BY A COUPLE OF TROUGHS TUESDAY AND WEDNESDAY. SURFACE HIGH PRESSURE WILL RESIDE OVER THE HIGH PLAINS SUNDAY. A TROUGH WILL MOVE INTO EASTERN COLORADO MONDAY AND THEN SHIFT EAST TUESDAY WITH A COLD FRONT MOVING INTO THE REGION. SURFACE HIGH PRESSURE WILL CONTINUE WEDNESDAY. A COUPLE OF SHORTWAVE TROUGHS WILL BRING A SLIGHT CHANCE OF RAIN AND SNOW TO THE FA MONDAY NIGHT AND TUESDAY. THE MOISTURE AND LIFT SUPPORT AT LEAST SLIGHT CHANCE POPS. OTHERWISE ALL OTHER PERIODS WILL BE DRY. MAX TEMPERATURES FROM SUNDAY THROUGH WEDNESDAY SHOULD REACH THE LOWER 50S WITH SOME MID TO UPPER 40S TUESDAY. MIN TEMPERATURES SHOULD BE IN THE MID AND UPPER 20S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1014 AM MST THU FEB 18 2016 AT KGLD...GUST SOUTHWESTERLY SURFACE WINDS WILL DEVELOP EARLY THIS AFTERNOON AND CONTINUE THROUGH TONIGHT. PEAK GUSTS EXPECTED TO BE IN THE 30 TO 40 KT RANGE. A COLD FRONT WILL MOVE THROUGH LATE THIS EVENING WITH WINDS SHIFTING TO NORTHWEST. BRIEF WIND GUSTS OVER 40 KTS WILL BE POSSIBLE BEHIND THE FRONT...DIMINISHING BY MORNING. AT KMCK...LIGHT AND VARIABLE WINDS EXPECTED THROUGH THIS AFTERNOON. WINDS WILL PICK UP THIS EVENING AHEAD OF A FRONT THEN INCREASE BEHIND THE FRONT BY LATE EVENING. BRIEF WIND GUSTS OVER 40 KTS WILL BE POSSIBLE BEHIND THE FRONT...DIMINISHING BY MORNING. && .FIRE WEATHER... ISSUED AT 322 AM MST THU FEB 18 2016 FORECAST APPEARS TO BE IN LINE FOR CRITICAL FIRE WEATHER CONDITIONS AT LEAST THE SOUTHERN HALF OF OUR CWA. THERE IS LESS CERTAINTY NORTH OF INTERSTATE 70 AS A RESULT OF HIGH CLOUD COVER POTENTIALLY LIMITING MIXING WHICH IMPACTS RH AND WINDS. LOWER BOUNDARY LAYER WINDS ADVERTISED BY MOST GUIDANCE IN OUR NORTH AS A RESULT OF A SHIFT IN SURFACE LOW POSITION ALSO LOWERS CONFIDENCE IN MEETING A 3HR DURATION OF WINDS IN OUR NORTHERN CWA. I WAS COMFORTABLE KEEPING CURRENT RED FLAG WARNING IN PLACE AND ADDING THOMAS AND SHERIDAN TO RFW AS THESE LOCATIONS SHOULD BE ABLE TO MEET THE 3HR CROSSOVER OF WIND/RH EVEN IF WINDS ARE NOT QUITE AS STRONG. I DECIDED TO CANCEL THE FIRE WEATHER WATCH FOR YUMA (CO)...CHEYENNE (KS)...AND RAWLINS (KS) AS CONFIDENCE IS MUCH LOWER AND WE ARE TOO CLOSE TO THE EVENT TO HANG ONTO THE WATCH ANY LONGER. HAVING SAID THIS...IF CLOUD COVER ENDS UP BEING MUCH LESS THIS AFTERNOON AND FULL MIXING IS ACHIEVED THE RFW MAY NEED TO BE EXPANDED NORTH. THIS SITUATION NEEDS TO BE MONITORED. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE ALONG THE CO/KS BORDER FRIDAY AFTERNOON AS LEE TROUGH BEGINS TO REDEVELOP AND SOUTHERLY SURFACE GRADIENT INCREASES. THIS WILL BE MONITORED...HOWEVER CONFIDENCE IS LOW IN REACHING THE 3HR REQUIREMENT FOR FIRE WEATHER HIGHLIGHTS. && .CLIMATE... ISSUED AT 322 AM MST THU FEB 18 2016 RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES TODAY. SITE.............DAILY RECORD...CURRENT FORECAST GOODLAND, KS.........74...............78 MCCOOK, NE...........82...............75 BURLINGTON,CO........74...............78 HILL CITY,KS.........75...............82 COLBY, KS............81...............79 TRIBUNE, KS..........79...............82 YUMA, CO.............73...............74 CURRENT FEBRUARY MONTHLY HIGH TEMP RECORDS... GOODLAND.....81 (02-28-2006 AND PREVIOUS YEARS) MCCOOK.......83 (02-23-1933 AND PREVIOUS YEARS) BURLINGTON...82 (02-11-1962) HILL CITY....86 (02-28-2006 AND PREVIOUS YEARS) COLBY........83 (02-12-1911) TRIBUNE......81 (02-20-1981) YUMA.........79 (02-12-1962 AND PREVIOUS YEARS) && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ013>015-027>029-041-042. CO...RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ253-254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...FS AVIATION...024 FIRE WEATHER...DR CLIMATE...DR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1200 PM CST THU FEB 18 2016 .UPDATE... ISSUED AT 436 AM CST THU FEB 18 2016 A CHECK ON THE NAM SHOWS ELEVATED INSTABILITY TONIGHT WITH 100 TO 200 J/KG OF CAPE. THE REFLECTIVITY PRODUCT AND K INDICES OVER 30 SUGGEST ISOLATED HIGH BASED THUNDERSTORMS ARE POSSIBLE. A NEW FORECAST HAS BEEN ISSUED FOR THIS FEATURE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 322 AM CST THU FEB 18 2016 TODAY AND TONIGHT...A BLEND OF THE 4 GUIDANCE DATA SET PLUS BIAS CORRECTION SUGGESTS HIGHS IN THE LOWER 70S TODAY. IT LOOKS LIKE HIGH CLOUDS WILL BE IN AND OUT OF THE FCST AREA SO THE WARMEST NUMBERS PROBABLY WOULD NOT VERIFY. THE BAROCLINIC LEAF STRETCHING ACROSS THE WRN U.S. WILL MOVE OVER THE FCST AREA TODAY. THE LATEST MODELS SHOW HIGH WINDS MORE LIKELY TONIGHT. THE RAP MODEL INDICATES AN ASTONISHING 3 HR PRESSURE RISE OF 13 MB NEAR RAWLINS WY AT 01Z TONIGHT. THIS COUPLED WITH A PV1.5 ANOMALY AND H850 WINDS RISING TO 60-70KT PRODUCES A MODERATE OR HIGHER POTENTIAL FOR HIGH WINDS ACROSS WRN AND NCNTL NEB. THE GFS20 CLOCKS THE COLD FRONT MOVING EAST AT 60 MPH. THE NAM FCSTS WIND GUSTS APPROACHING 70 MPH IN SOME LOCATIONS. THIS WOULD BE THE MAX WE WOULD EXPECT ASSUMING A MIXED LAYER FORMS ALONG THE COLD FRONT. PEAK WIND GUSTS WOULD LAST 1 TO 2 HOURS AS THE FRONT RACES THROUGH THE FCST AREA BETWEEN 03Z AND 09Z. THE PV1.5 ANOMALY SUGGESTS INTERSTATE 80 AND NCNTL NEB ALONG AND EAST OF HIGHWAY 83 WOULD BE MOST FAVORED FOR HIGH WINDS. THE NAM WIND GUSTS INDICATE ALL ZONES. THE GFS SOUNDINGS FOR NORTH PLATTE SHOW A MIXED LAYER EXTENDING TO 550MB AT 03Z JUST AHEAD OF THE COLD FRONT WHICH COLLAPSES TO 780MB BEHIND THE FRONT. THE 500M AGL TEMPERATURE FALLS FROM 73F AT 03Z TO 47F AT 06Z WITH 55 TO 65 KT WINDS AT THIS LEVEL...OFF THE CHARTS. A HIGH WIND WATCH IS IN PLACE FOR ALL ZONES TONIGHT. THE RAP AND HRRR MODELS COULD PERHAPS CULL SOME COUNTIES FROM THE WATCH LATER TODAY. THE MODEL CONSENSUS SUGGEST SPRINKLES OR ISOLATED SHOWERS TONIGHT...MAINLY ALONG AND NORTH OF HIGHWAY 20. THIS WOULD EASILY MIX THE STRONG WINDS ALOFT DOWN TO THE SFC IN THESE AREAS. THUS THE CONVECTION MAY WORK FOR HIGH WINDS WHERE THE PV1.5 ANOMALY IS ABSENT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 322 AM CST THU FEB 18 2016 MID RANGE...FRIDAY AND SATURDAY...MAIN FORECAST CHALLENGES ARE TEMPERATURES AND WIND. GUSTY WINDS CONTINUE IN THE WAKE OF THE STRONG PACIFIC FRONT AND PV ANOMALY WHILE DOWNSLOPE WINDS AND WARM 850HPA TEMPS CONTRIBUTE TO WELL ABOVE NORMAL HIGHS. GFS AND NAM KEEP LOW/MID LEVEL WINDS AOA 40 KTS THROUGH 18Z FRIDAY...PRIMARILY ACROSS THE NORTHERN HALF OF THE FORECAST AREA. WIDESPREAD SUBSIDENCE WILL RESULT IN FAIR CONDITIONS AND A WELL MIXED BOUNDARY LAYER. FORECAST SOUNDINGS SHOW MIXING TO 700HPA AT KLBF AND KVTN FRIDAY AFTERNOON WITH NEARLY UNIDIRECTIONAL WINDS. EDGED MAX TEMPS CLOSER TO THE MAV AND ECS GUIDANCE...WHICH BOTH SHOW UPPER 60S FOR MOST OF WESTERN NEBRASKA. A WEAK FRONT DROPS SOUTH ACROSS THE REGION SATURDAY...RESULTING IN SLIGHTLY COOLER MAX TEMPS NORTH BUT ABOUT THE SAME SOUTH. SOUNDINGS STILL INDICATE GOOD MIXING SATURDAY...BUT WIND WILL NOT BE A BIG AN ISSUE AS THE MID AND UPPER LEVEL SUPPORT WILL HAVE MOVED EAST. LONG RANGE...SUNDAY TO WEDNESDAY...A COUPLE WAVES TRAVERSE THE AREA SUNDAY AND TUESDAY WHILE 500HPA FLOW TRANSITIONS FROM QUASI ZONAL TO NORTHWEST. A SURFACE HIGH BUILDING OVER THE NORTHERN PLAINS AND 850HPA CAA LEADING TO TEMPS NEAR 0C AT 18Z SUNDAY WILL TAKE HIGHS MUCH CLOSER TO NORMAL. FRONTOGENESIS LOOKS IMPRESSIVE EARLY SUNDAY...BUT MOISTURE AND LIFT ARE LACKING. SOUTHERLY FLOW RETURNS MONDAY WITH LITTLE IN TERMS OF TEMPERATURE RECOVERY. THE GFS AND EURO SHOW BETTER MOISTURE AND MARGINAL LIFT FOR THE SYSTEM ON TUESDAY...HOWEVER DISCREPANCIES REMAIN WITH THE TIMING OF THE BEST FORCING. EXTENDED PROCEDURE INTRODUCED SCHC POPS...BUT DECIDED TO KEEP DRY WITH THIS FORECAST PACKAGE DUE TO LOW CONFIDENCE. MORE DOWNSLOPING WINDS WITH A 850HPA RIDGE AXIS MOVING THROUGH THE SANDHILLS WEDNESDAY...PUSHING HIGHS INTO THE LOWER 50S AGAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1159 AM CST THU FEB 18 2016 HIGH CIRRUS EXPECTED TO PUSH ACROSS THE AREA WITH GENERALLY VFR CONDITIONS EXPECTED. A COLD FRONT WILL MOVE ACROSS THE AREA OVERNIGHT WITH A SIGNIFICANT WIND CHANGE BEHIND THE FRONT. LIGHT WINDS WILL BECOME VERY GUSTY NORTHWEST WINDS. WINDS COULD GUST TO AROUND 45 KTS...HOWEVER WINDS JUST OFF THE SURFACE COULD GUST TO 60 KTS. NOT ENOUGH OF A CHANGE FOR LOW LEVEL WIND SHEAR...HOWEVER IF ANY DECOUPLING OCCURS IN RIVER VALLEYS...LLWS WOULD BE AN ISSUE. WINDS DIMINISH QUICKLY IN THE MORNING HOURS. && .LBF WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM 6 PM CST /5 PM MST/ THIS EVENING THROUGH LATE TONIGHT FOR NEZ004>010-022>029-035>038-056>059-069>071-094. && $$ UPDATE...CDC SHORT TERM...CDC LONG TERM...SNIVELY AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
409 PM CST THU FEB 18 2016 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 350 PM CST THU FEB 18 2016 A DYNAMIC AND SPRING-LIKE SYSTEM WILL CROSS THE AREA TONIGHT WITH DENSE FOG AHEAD OF IT AND STRONG WINDS IN ITS WAKE FROM TONIGHT THROUGH FRIDAY. AS OF 21 UTC...A STRONG SURFACE LOW IS DEEPENING IN SOUTHEASTERN MT WITH A MINIMUM PRESSURE NEAR 986 MB SOUTHEAST OF BILLINGS. THE 12 UTC GLOBAL MODEL GUIDANCE AGREES THAT THIS LOW WILL MOVE EAST ALONG THE ND/SD BORDER TONIGHT. IN ADVANCE OF THE LOW...HIGH LOW- LEVEL MOISTURE CONTENT ON LIGHT SOUTHEAST FLOW WITH DEWPOINTS IN THE LOWER TO MIDDLE 30S F BENEATH A STOUT INVERSION ALOFT THANKS TO ANOMALOUS LOW- TO MID-LEVEL WARMTH IS CONTRIBUTING TO A VERY FAVORABLE ENVIRONMENT FOR LOW CLOUDS AND FOG. VISIBILITIES FROM NEAR NEW SALEM NORTHWARD INTO NORTHWEST AND NORTH CENTRAL ND AS OF MID AFTERNOON ARE STILL BELOW 1/2SM IN MANY AREAS...AND WITH THE FAVORABLE SETUP AND CONSISTENT HRRR AND ESRL-HRRR MODEL RUNS SHOWING WIDESPREAD DENSE FOG THIS EVENING OVER MUCH OF CENTRAL AND NORTHWEST ND WE ISSUED A DENSE FOG ADVISORY ACROSS MUCH OF THE AREA. THE ADVISORY GOES THROUGH 06 UTC...EXCEPT OVER NORTH CENTRAL ND WHERE WE RAN IT UNTIL 12 UTC. WE ACTUALLY EXPECT FOG TO LIFT OVERNIGHT AS THE SURFACE LOW SHIFTS EAST AND THE COLD FRONT ACCOMPANYING THE SHORTWAVE TROUGH ALOFT FOLLOWS SUITE AND INCREASES BOUNDARY LAYER SUBSIDENCE. WE MADE NO CHANGES TO THE TYPE OR AREAL EXTENT OF WIND HEADLINES WITH THIS ISSUANCE. HOWEVER...WE DID ADJUST THE START TIMES SUCH THAT THE WIND ADVISORY AND HIGH WIND WARNINGS OVER SOUTHWEST AND WEST CENTRAL ND START AT 03 UTC TONIGHT...AND THE WIND ADVISORY FOR THE REST OF SOUTH CENTRAL ND STARTS BETWEEN 06 AND 08 UTC. THAT MOVE WAS BASED ON INITIAL PRESSURE RISES THAT WILL FOLLOW THE SURFACE LOW EASTWARD TONIGHT. IT IS POSSIBLE AN EXPANSION OF THE HIGH WIND WARNING A BIT FURTHER NORTH AND EAST MAY BE NEEDED IF ISALLOBARIC FORCING OVERCOMES NOCTURNAL STABILIZING EFFECTS AS RECENT RAP ITERATIONS HAVE SHOWN 8-10 MB/3 HOUR PRESSURE RISES MOVING EASTWARD ACROSS ALL OF FAR SOUTH CENTRAL ND TONIGHT. WINDS ON FRIDAY WILL BE STRONG AREA-WIDE DUE TO BOUNDARY LAYER MIXING. THE 12 UTC GFS WAS A BIT STRONGER WITH BOUNDARY LAYER WINDS THAN THE 12 UTC NAM AND SUGGESTS THERE IS A CHANCE THAT THE HIGH WIND WARNING AGAIN MAY NEED TO BE EXPANDED A BIT FURTHER NORTH AND TO THE EAST...BUT CONFIDENCE WAS NOT HIGH ENOUGH TO DO THAT YET AS FORECAST SOUNDINGS EVEN FROM THE GFS SUGGEST THE LOW LEVELS MAY NOT BE COMPLETELY DRY ADIABATIC. WE DO EXPECT A BAND OF PRECIPITATION TO CROSS THE REGION TONIGHT WITH THE STRONG SHORTWAVE...BUT THERMAL PROFILES SUGGEST IT WILL BE IN THE FORM OF RAIN IN MOST AREAS. WE ARE STILL CARRYING SOME LOW-END CHANCES OF LIGHT FREEZING RAIN IN NORTH CENTRAL ND...BUT CONFIDENCE IN ANY IMPACTS FROM THAT IS LOW GIVEN A RATHER NARROW WINDOW OF OPPORTUNITY AND THE POTENTIAL FOR ROADS TO BE CLOSE TO OR ABOVE 32 F IN MANY AREAS. FINALLY...THE STRONG WINDS AND WARM TEMPERATURES ON FRIDAY WILL YIELD SOME CONCERNS FOR FIRE WEATHER IN SOUTHWEST ND...AS NOTED IN THE FIRE WEATHER DISCUSSION BELOW. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 350 PM CST THU FEB 18 2016 ANOTHER CLIPPER MOVES THROUGH SATURDAY THROUGH SUNDAY. A MIX OF PRECIPITATION TYPES IS EXPECTED SATURDAY INTO SATURDAY EVENING...BUT SHOULD TURN TO ALL SNOW BY LATE SATURDAY NIGHT THROUGH SUNDAY. THERE COULD BE SOME LIGHT SNOW ACCUMULATIONS ACROSS THE NORTHEAST WITH THIS SYSTEM...WITH GENERALLY LESS THAN AN INCH EXPECTED. AFTER SUNDAY COOLER AND MAINLY DRY CONDITIONS WILL TAKE OVER. TEMPERATURES WILL RANGE FROM THE UPPER 20S TO LOW 40S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1146 AM CST THU FEB 18 2016 EARLY THIS AFTERNOON...LINGERING AREAS OF FOG AND WIDESPREAD IFR/LIFR CEILINGS/VISIBILITIES WERE IN PLACE OVER ALL SITES WITH THE EXCEPTION OF KBIS. EXPECT SCATTERED TO WIDESPREAD LOWER CEILINGS TO REMAIN OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE AFTERNOON. THAT BEING SAID...GUIDANCE IS SHOWING A BRIEF OPPORTUNITY FOR SOME MVFR/VFR CEILINGS OVER KISN/KDIK LATE THIS AFTERNOON OR EARLY THIS EVENING. LOW PRESSURE WILL THEN SPREAD LIGHT RAIN ACROSS THE STATE FROM WEST TO EAST...LOWERING CEILINGS ONCE AGAIN. BEHIND THE LOW PRESSURE ON FRIDAY MORNING...CEILINGS WILL LIFT TO VFR AT ALL SITES WITH GUSTY NORTH NORTHWEST WINDS THROUGH THE EARLY AFTERNOON. WINDS MAY GUST FROM 30-45 KNOTS AT TIMES. && .FIRE WEATHER... ISSUED AT 350 PM CST THU FEB 18 2016 STRONG WEST TO NORTHWEST WINDS GUSTING FROM 50 TO 60 MPH FRIDAY WILL POSE A CONCERN FOR WIND-DRIVEN FIRES...ESPECIALLY OVER FAR SOUTHWESTERN ND WHERE MINIMUM HUMIDITIES MAY REACH 30 PERCENT. IF PRECIPITATION IN FAR SOUTHWESTERN ND IS LESS THAN A TENTH OF AN INCH TONIGHT AND THE WFAS...NFDRS FIRE DANGER RATING ENDS UP IN THE HIGH OR GREATER CATEGORY...A RED FLAG WARNING COULD BE NEEDED WITH THE MORNING FORECAST RELEASE. THE AREA OF PRIMARY CONCERN IS ACROSS SLOPE...BOWMAN...AND ADAMS COUNTIES. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR NDZ001-002-009-010-019-020-034-035-042. WIND ADVISORY FROM MIDNIGHT CST /11 PM MST/ TONIGHT TO 6 PM CST /5 PM MST/ FRIDAY FOR NDZ019-020-034-035-042-045-046. WIND ADVISORY FROM 9 PM CST /8 PM MST/ THIS EVENING TO 6 PM CST /5 PM MST/ FRIDAY FOR NDZ017-018-031>033-041. DENSE FOG ADVISORY UNTIL 6 AM CST FRIDAY FOR NDZ003>005-011>013- 021>023. WIND ADVISORY FROM 9 AM TO 6 PM CST FRIDAY FOR NDZ003>005- 010>013-021>023-025. WIND ADVISORY FROM 2 AM TO 6 PM CST FRIDAY FOR NDZ036-037-047- 048-050-051. HIGH WIND WARNING FROM 8 PM THIS EVENING TO 5 PM MST FRIDAY FOR NDZ040-043-044. && $$ SHORT TERM...CJS LONG TERM...AJ AVIATION...ZH FIRE WEATHER...CJS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1006 AM MST THU FEB 18 2016 .UPDATE... ISSUED AT 952 AM MST THU FEB 18 2016 SURFACE TROUGH AND STATIONARY BOUNDARY STRETCH ACROSS WESTERN INTO CENTRAL SD. SOUTHWESTERLY WINDS ARE BECOMING GUSTY ACROSS NORTHWESTERN WY...AND HAVE ISSUED A BLOWING DUST ALERT FOR THE POWDER RIVER BASIN THROUGH FRIDAY MORNING. FORECAST SOUNDINGS INDICATE SOME GUSTY WINDS COULD MIX DOWN TO THE RAPID CITY AREA EARLY THIS AFTERNOON...SO MAY ISSUE AN AIR QUALITY ALERT THERE AS WELL. FOG HAS MOSTLY DISSIPATED ACROSS NORTHWESTERN SD...EXCEPT ALONG THE ND BORDER. TEMPS ARE RISING INTO THE 50S AND LOWER 60S...WITH 30S ACROSS NORTHWESTERN SD. && .SHORT TERM...TODAY THROUGH FRIDAY NIGHT ISSUED AT 351 AM MST THU FEB 18 2016 UPPER RIDGING SITS ACROSS THE CNTRL THIRD OF THE CONUS WITH THE MAIN AXIS NOW CROSSING THE DAKOTAS. A TROUGH/CUT OFF LOW IS CENTERED ALONG THE PAC NW COAST WITH A STRONG WAVE ROUNDING THE BASE ATTM. SWRLY LOW LEVEL FLOW HAS INCREASED OVER THE LAST FEW HOURS ACROSS NE WY AND THE NRN FOOTHILLS OF THE BLKHLS. OBS ALONG THE FOOTHILLS HAVE BEEN REPORTING VERY GUSTY WINDS WITH KSPF EVEN REACHING HIGH WIND WARNING CRITERIA BRIEFLY. THESE DOWNSLOPING WINDS HAVE RESULTED IN TEMPS RISING TO AROUND 60 DEGREES...WITH MANY OF THESE AREAS SEEING A 15 DEGREE JUMP WITHIN MINUTES. STRONG UPPER WAVE WILL QUICKLY PUSH ACROSS THE GREAT BASIN THIS MORNING...AND WYOMING THIS AFTERNOON. STRONG SWRLY FLOW WILL CONTINUE WITH INCREASING WARM AIR ADVECTION. THIS WILL MAKE FOR AN UNUSUALLY WARM DAY TODAY...WITH MANY LOCATIONS LIKELY BREAKING DAILY RECORD HIGHS. THE WAVE WILL BRING SOME SHOWERS TO THE AREA THIS EVENING...MAINLY ACROSS NE WY THROUGH THE BLKHLS AREA AND NW SD. HOWEVER WITH THE SPEED OF THE WAVE...THESE SHOWERS WILL QUICKLY PUSH THROUGH. WITH STEEP MIDLEVEL LAPSE RATES...COULD EVEN SEE A FEW LIGHTNING STRIKES. PRECIP WILL END LATE TONIGHT ACROSS THE AREA AS THE WAVE MOVES INTO THE MIDWEST. DRY WEATHER AND MOSTLY SUNNY SKIES ARE THEN EXPECTED FRIDAY...WITH HIGHS IN THE MID 50S TO MID 60S. THE CONCERN OF THE DAY WILL BE THE STRONG WINDS EXPECTED. SW WINDS AHEAD OF THE APPROACHING WAVE WILL INCREASE THIS MORNING ACROSS NE WY AND THE BLKHLS AREA THROUGH THE DAY...ESPECIALLY THIS AFTERNOON. FORECAST PROFILES AND THE LATEST HRRR SHOW GUSTS REACHING 50 TO 60 MPH MORE TOWARD THE AFTERNOON. HOWEVER SINCE THE NRN BLKHLS ALREADY HAS A HIGH WIND WARNING FOR DOWNSLOPING WINDS...WILL JUST EXTEND IT OUT. AS THE WAVE CROSSES THE AREA LATE THIS AFTERNOON INTO THE EVENING...A FAST MOVING COLD FRONT WILL PUSH ACROSS THE AREA. MODELS ARE SHOWING 50 TO EVEN 60 KT WINDS DEVELOPING WITHIN 5KFT OF THE SURFACE ACROSS NE WY AND MUCH OF WRN SD. SO WILL GO WITH A HIGH WIND WARNING FOR THE OVERNIGHT HOURS. THERE LOOKS TO BE A LITTLE BIT OF A LULL SETTING UP LATE TONIGHT SO WINDS COULD DROP TO BELOW CRITERIA...HOWEVER A SURFACE LOW CROSSING SRN CANADA FRIDAY WILL REINFORCE THE TIGHT PRESSURE GRADIENT. THIS WILL RESULT IN VERY STRONG WINDS AGAIN ACROSS THE AREA. WINDS WILL DECREASE FROM WEST TO EAST...SO THINK AREAS LIKE NE WY AND THE BLKHLS WILL SEE WARNING CRITERIA WINDS END BY MIDDAY FRIDAY...WHILE THE WRN SD PLAINS WILL CONTINUE TO SEE STRONG WINDS UNTIL LATE IN THE AFTERNOON. .LONG TERM...SATURDAY THROUGH WEDNESDAY ISSUED AT 351 AM MST THU FEB 18 2016 PROGRESSIVE UPPER FLOW FLOW WILL PERSIST INTO EARLY NEXT WEEK...WITH TRANSITION TO AMPLIFIED WEST COAST RIDGE AND BROAD TROF FROM THE PLAINS TO THE GREAT LAKES FOR THE MIDDLE OF THE WEEK. DRY WEATHER AND ABOVE AVERAGE TEMPERATURES EXPECTED FOR SUNDAY/MONDAY. AS FLOW BECOMES NORTHWESTERLY MID WEEK...ENSEMBLE MEMBERS SUGGEST MORE UNCERTAINTY WITH TEMPERATURES AS LOW LEVEL BAROCLINIC ZONE BACKS INTO FORECAST AREA. WITH LACK OF DECENT SHORTWAVES CROSSING THE AREA...WILL MAINTAIN DRY FORECAST. && .AVIATION...FOR THE 18Z TAFS THROUGH 18Z FRIDAY ISSUED AT 952 AM MST THU FEB 18 2016 LINGERING IFR/LIFR FOG NEAR THE ND BORDER SHOULD ERODE BY EARLY AFTN. OTHERWISE...VFR CONDITIONS EXPECTED THROUGH TONIGHT. VERY GUSTY SW/W WINDS ARE EXPECTED ACROSS MUCH OF THE REGION TODAY...THEN STRONG NW WINDS ARE EXPECTED TONIGHT BEHIND A CDFNT...WITH WDSPRD GUSTS OVER 50KTS POSSIBLE. -SHRA AND POSSIBLE A FEW -TSRA LATE THIS AFTN AND TONIGHT...BUT CIGS SHOULD BE HIGH BASED. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...HIGH WIND WARNING UNTIL NOON MST FRIDAY FOR SDZ024. HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 PM MST FRIDAY FOR SDZ001-002-012>014-026-027-030>032-041>044-073-074. HIGH WIND WATCH FROM LATE TONIGHT THROUGH FRIDAY EVENING FOR SDZ046-047-049. HIGH WIND WARNING UNTIL NOON MST FRIDAY FOR SDZ028-029. HIGH WIND WARNING UNTIL 6 PM MST FRIDAY FOR SDZ025-072. WY...HIGH WIND WARNING UNTIL NOON MST FRIDAY FOR WYZ057. HIGH WIND WARNING UNTIL NOON MST FRIDAY FOR WYZ054>056-058-071. && $$ UPDATE...POJORLIE SHORT TERM...13 LONG TERM...7 AVIATION...JOHNSON
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
309 PM EST THU FEB 18 2016 .SHORT TERM (TONIGHT AND TOMORROW)... QUIET WEATHER WITH NEAR AVERAGE TEMPERATURES WILL BE THE THEME IN THE SHORT-TERM FORECAST. CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A RIDGE MOVING IN FROM THE WEST. AT THE SURFACE...A RIDGE OF HIGH PRESSURE EXTENDS ACROSS THE AREA. THANKS TO HIGHER HEIGHTS ALOFT AND PLENTY OF INSOLATION...TEMPERATURES HAVE WARMED ACROSS THE AREA INTO THE MID 40S TO MID 50S. THE SURFACE HIGH WILL SHIFT TO THE EAST TONIGHT WITH SOUTHERLY FLOW RETURNING ACROSS THE SOUTHERN VALLEY AND PLATEAU BEFORE SUNRISE...LOWS IN THESE LOCATIONS WILL ONLY DROP INTO THE UPPER 30S TO LOWS 40S. FURTHER TO THE NORTH AND EAST...CALM WINDS AND CLEAR SKIES WILL ALLOW FOR IDEAL RADIATIONAL COOLING WITH LOWS GENERALLY IN THE LOWER 30S. TEMPERATURES WILL CONTINUE TO MODERATE TOMORROW AS THE UPPER LEVEL RIDGE AXIS MOVES TO THE EAST. HIGHER HEIGHTS ALOFT AND A CONTINUED SUPPLY OF SUNNY SKIES WILL PUSH HIGH TEMPERATURES UP INTO THE MID 50S TO LOW 60S. .LONG TERM (FRIDAY NIGHT THROUGH THURSDAY)... AT THE BEGINNING OF THIS PERIOD...ALOFT WE ARE UNDER A ZONAL FLOW TO SLIGHT RIDGING OVER THE AREA...AND AT THE SURFACE WE HAVE A SOUTHERLY RETURN FLOW AS THE SURFACE HIGH SITS OFF THE MID-ATLANTIC COAST. THE NEXT COLD FRONT LOOKS TO SAG SOUTHWARD THROUGH THE AREA AROUND SUNDAY EVENING...AND WE STAY IN THE COOL AIR THROUGH THE REMAINDER OF THE FORECAST PERIOD. A SHORTWAVE TROUGH APPROACHES AND MOVES THROUGH THE AREA DURING THE MIDDLE OF NEXT WEEK. THE SHORTWAVE INDUCING SURFACE LOW PRESSURE TO DEVELOP ALONG THE FRONTAL BOUNDARY ALONG THE CENTRAL GULF COAST BY ABOUT TUESDAY...THEN THE SURFACE LOW TRACKS EAST AND THEN NORTHEAST UP THE ATLANTIC COAST THROUGH THE REMAINDER OF THE FORECAST PERIOD. WITH THE MOISTURE RETURN WE ARE ALREADY GETTING A CHANCE OF SHOWERS BY LATE FRIDAY NIGHT. LOOKS LIKE MOST OF THE AREA WILL KEEP SOME POPS THROUGH MOST OF THE REST OF THE FORECAST. GOING A LITTLE BELOW GUIDANCE FOR NEXT THURSDAY...AS THERE IS GOOD AGREEMENT THAT THE SYSTEM WILL BE PULLING OUT BY THEN. THIS WILL LEAVE SOME <20 POPS IN THE NORTHEAST AND CENTRAL AND NORTHERN MOUNTAINS. THE MODELS SEEM TO BE GETTING WARMER AND WARMER NOW FOR THE SYSTEM NEXT WEEK...AND LEAVE THE TROUGH AS AN OPEN AND WEAKER WAVE. SO LITTLE IN THE WAY OF WINTRY PRECIP IS IN THIS FORECAST FOR THE SYSTEM NEXT WEEK AS OF NOW. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 39 63 47 62 / 0 0 20 30 KNOXVILLE MCGHEE TYSON AIRPORT, TN 35 61 46 59 / 0 0 20 40 OAK RIDGE, TN 35 63 46 59 / 0 0 20 30 TRI CITIES AIRPORT, TN 31 58 40 56 / 0 0 20 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ MA/GM
AREA FORECAST DISCUSSION
NWS SEATTLE WA
245 PM PST THU FEB 18 2016 .SYNOPSIS...AN UPPER LEVEL TROUGH IN WESTERN WASHINGTON WILL MOVE NORTHEAST INTO BRITISH COLUMBIA THIS EVENING. THE TROUGH WILL BRING SHOWERS TO THE LOWLANDS AND WILL GIVE SNOW TO THE MOUNTAINS. A VIGOROUS FRONT WILL MOVE MOVE ACROSS THE AREA ON FRIDAY BRINGING RAIN...MOUNTAIN SNOW...AND LOCALLY WINDY CONDITIONS. SHOWERS WILL END ON SATURDAY AS A WEAK UPPER LEVEL RIDGE MOVES ACROSS THE AREA. ANOTHER FRONTAL SYSTEM WILL MOVE ONSHORE SUNDAY AFTERNOON OR EVENING. THE WEATHER NEXT WEEK WILL BE MILD AND DRY EXCEPT FOR A CHANCE OF LIGHT PRECIPITATION TUESDAY NIGHT AND WEDNESDAY. && .SHORT TERM...SATELLITE IMAGERY SHOWS AN UPPER LEVEL TROUGH OVER WESTERN WASHINGTON THIS AFTERNOON. RADARS ARE SHOWING SHOWERS IN THE MOUNTAINS AND OVER THE OLYMPIC PENINSULA. THUNDERSTORMS HAVE REMAINED WELL SOUTHEAST OF THE AREA NEAR THE DALLES ON THE COLUMBIA RIVER. THE LATEST 18Z GFS HAS BACKED OFF SLIGHTLY ON PRECIPITATION AMOUNTS IN THE MOUNTAINS WITH 0.3 TO 0.6 INCHES OF WATER IN THE CENTRAL AND SOUTH CASCADES WHILE THE HRRR IS TRENDING A BIT DRIER AND RADAR IMAGERY IS SHOWING A BREAK FROM ABOUT SEATTLE SOUTHWARD IN THE INTERIOR LOWLANDS. WHILE MARGINAL...WILL MAINTAIN THE WINTER WEATHER ADVISORY IN THE CASCADES OVERNIGHT. A VIGOROUS FRONTAL SYSTEM NOW NEARING 135W WILL MOVE EAST ACROSS THE AREA...MOVING ONTO THE COAST MIDDAY FRIDAY AND INTO THE CASCADES BY EVENING. THE FRONT WILL BE ACCOMPANIED BY A PERIOD OF MODERATE RAINFALL IN THE LOWLANDS ALONG WITH BREEZY TO LOCALLY WINDY CONDITIONS. SNOWFALL IN THE MOUNTAINS ABOVE ABOUT 4000 FEET WILL RANGE FROM 3 TO 8 INCHES IN THE OLYMPICS AROUND HURRICANE RIDGE...AND IN THE CASCADES. ONSHORE FLOW BEHIND THE FRONT FRIDAY NIGHT WILL KEEP SHOWERS AND LOCALLY WINDY CONDITIONS GOING IN THE LOWLANDS AND WILL GIVE LOCALLY HEAVY SNOW SHOWERS TO THE WEST SLOPES OF THE OLYMPICS. THE 18Z GFS20 CONTINUES TO SHOW SNOWFALL AMOUNTS OF 3 TO 8 INCHES IN THE CASCADES FRIDAY NIGHT WITH HEAVIEST AMOUNTS IN THE NORTH CASCADES AND IN THE CASCADES OF KING AND PIERCE COUNTIES. WINTER WEATHER ADVISORIES ARE UP FOR ALL OF THE MOUNTAINS ON FRIDAY...AND FOR THE CASCADES FRIDAY NIGHT. CONDITIONS ARE EXPECTED TO IMPROVE SATURDAY MORNING. SHOWERS ON SATURDAY WILL MAINLY BE CONFINED TO THE MOUNTAINS AND WILL BE MORE LIKELY DURING THE MORNING HOURS AS LINGERING ONSHORE FLOW RELAXES. BY SATURDAY AFTERNOON AND EVENING...SHORT WAVE RIDGING AND LOW LEVEL OFFSHORE FLOW WILL GIVE RELATIVELY NICE CONDITIONS TO THE AREA. THE LATEST GFS AND ECMWF SOLUTIONS BOTH SHOW SUNDAYS FRONT MOVING IN DURING THE SECOND HALF OF THE DAY. SO THE FORECAST WILL INDICATE CLOUDS WITH AN INCREASING CHANCE OF RAIN IN THE AFTERNOON. ALBRECHT .LONG TERM...OVERALL...LONG TERM MODELS ARE SHOWING NEXT WEEK TO BE NICE WITH LONG WAVE RIDGING OVERHEAD OR NEARBY AND LOW LEVEL OFFSHORE FLOW DOMINATING. THERE WILL BE A CHANCE OF LINGERING SHOWERS MONDAY AS ONSHORE FLOW SLOWLY RELAXES AHEAD OF AN INCOMING UPPER LEVEL RIDGE...THEN CONDITIONS WILL IMPROVE MONDAY AFTERNOON. TUESDAY APPEARS THAT IT WILL BE DRY AND MILD. TEMPERATURES IN THE INTERIOR SHOULD REACH THE MID 50S WITH OFFSHORE FLOW AND SOME SUNSHINE...AND THERE IS A CHANCE THAT TEMPERATURES WILL BE A BIT HIGHER THAN CURRENTLY FORECAST. A WEAKENING FRONT MAY MOVE ACROSS THE AREA TUESDAY NIGHT AND WEDNESDAY BRINGING A CHANCE OF LIGHT PRECIPITATION. THIS FRONT WILL BE MOVING INTO A BUILDING LONG WAVE RIDGE...SO RAIN CHANCES WILL NOT BE HIGH. STRONG UPPER RIDGING COMBINED WITH LOW LEVEL OFFSHORE FLOW WILL GIVE PLENTY OF SUNSHINE...DRY CONDITIONS...AND VERY MILD WEATHER WITH LOWS ONLY REACHING THE 40S AND HIGHS AROUND 60 AS WE MOVE INTO THE END OF NEXT WEEK. ALBRECHT && .AVIATION...WESTERLY FLOW ALOFT WILL DEVELOP TONIGHT THEN TURN SOUTHERLY FRIDAY. THE AIR MASS IS COOL AND UNSTABLE GIVING SCATTERED SHOWERS. AT THE SURFACE WINDS WILL TURN BRIEFLY ONSHORE THIS EVENING...THEN BECOME SOUTHERLY LATE TONIGHT AS A FRONT APPROACHES THE COAST. CONDITIONS WILL BE MOSTLY VFR EXCEPT FOR OCCASIONAL MVFR CEILINGS IN SHOWERS. SHOWERS ARE MORE LIKELY THIS EVENING WITH SOME LETUP LATE TONIGHT. RAIN WILL DEVELOP FRIDAY MORNING AND CEILINGS WILL FALL DURING THE DAY. KSEA...DISCUSSION ABOVE APPLIES. SOUTHERLY WINDS 10G15 KT EASING TO 4-8 KT BY 06Z. CHB && .MARINE...THERE ARE STILL GUSTY SMALL CRAFT ADVISORY LEVEL WINDS OVER MOST OF THE WATERS THIS AFTERNOON IN THE WAKE OF A FRONT THAT DISSIPATED OVER THE AREA TODAY. THESE WINDS WILL EASE A BIT TONIGHT. A STRONGER FRONT WILL MOVE THROUGH THE AREA FRIDAY. GALE FORCE WINDS ARE LIKELY ON THE COAST AND A GALE WARNING IS IN EFFECT. THE REST OF THE WATERS WILL HAVE AT LEAST ADVISORY STRENGTH WINDS. GALES ARE POSSIBLE BUT NOT CERTAIN AT THE STRAIT ENTRANCES AND OVER THE NORTHERN INLAND WATERS. THE ADVISORY LEVEL WINDS WILL LAST INTO FRIDAY NIGHT AS ONSHORE FLOW DEVELOPS IN THE WAKE OF THE FRONT. WESTERLY FLOW DOWN THE STRAIT OF JUAN DE FUCA MAY REACH GALE LEVELS FRIDAY AFTERNOON AND EVENING. THE NEXT PACIFIC FRONTAL SYSTEM WILL ARRIVE SUNDAY. GALE FORCE WINDS ARE POSSIBLE ON THE COAST WITH THIS SYSTEM. SURFACE FLOW WILL TURN OFFSHORE EARLY NEXT WEEK. CHB && .HYDROLOGY...FRONTAL SYSTEMS WILL BE PROGRESSIVE IN NATURE THROUGH THE WEEKEND...AND SNOW LEVELS WILL BE RATHER LOW. A TRANSITION TO A DRIER WEATHER PATTERN IS EXPECTED NEXT WEEK. RIVER FLOODING IS NOT EXPECTED FOR THE NEXT 7 DAYS. ALBRECHT && .SEW WATCHES/WARNINGS/ADVISORIES... WA...WINTER WEATHER ADVISORY UNTIL 6 AM PST SATURDAY FOR CASCADES OF PIERCE AND LEWIS COUNTIES. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM PST SATURDAY FOR CASCADES OF SNOHOMISH AND KING COUNTIES- CASCADES OF WHATCOM AND SKAGIT COUNTIES. WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 AM PST SATURDAY FOR OLYMPICS. PZ...SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 4 AM PST FRIDAY FOR GRAYS HARBOR BAR. SMALL CRAFT ADVISORY UNTIL 4 AM PST FRIDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM- COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM. GALE WARNING FROM 4 AM TO 4 PM PST FRIDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM- COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM. SMALL CRAFT ADVISORY UNTIL 4 AM PST SATURDAY FOR ADMIRALTY INLET- EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS-PUGET SOUND AND HOOD CANAL-WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO 4 AM PST SATURDAY FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA. && $$ WWW.WEATHER.GOV/SEATTLE YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
219 PM CST THU FEB 18 2016 .UPDATE... ISSUED AT 219 PM CST THU FEB 18 2016 ROUGH OUTLINE OF WIND ADVISORY THAT WILL BE ISSUED WITHIN THE HOUR IS FOUND IN THE ADVISORY SECTION AT BOTTOM. && .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 321 AM CST THU FEB 18 2016 SURFACE MAP SHOWS DEEP LOW PRESSURE MOVING EASTWARD OUT OF MONTANA WITH A WARM FRONT ARCHING THROUGH SD INTO EASTERN NE AND WESTERN MO. IR SATELLITE SHOWS A BAND OF ALTOSTRATUS IN ADVANCE OF THIS WARM FRONT COVERING ALL OF THE FORECAST AREA. COMBINATION OF CLOUD COVER AND LIGHT SOUTHEAST WINDFLOW KEEPING TEMPERATURES IN CHECK IN THE UPPER TEENS TO THE MIDDLE 20S AS OF 2 AM. SOUTHERLY FLOW PICKS UP TODAY INTO TONIGHT AS THE AREA OF LOW PRESSURE AND WARM FRONT APPROACH THE REGION. RAP BUFKIT SHOWS MOSTLY MID/HIGH CLOUD OVER THE AREA TODAY WITH STRATUS HOLDING OFF TO THE WEST...HOWEVER AS THE WARM FRONT APPROACHES THIS EVENING/OVERNIGHT... LOWEST 1.5KM OF COLUMN QUICKLY SATURATES LEADING TO WIDESPREAD STRATUS. LIFT/TURNING THROUGH THIS STRATUS WILL LEAD TO AREAS OF DRIZZLE WITH THE POSSIBILITY OF A LITTLE FREEZING DRIZZLE NORTH OF HIGHWAY 10 IN NORTH CENTRAL WI. ONLY LOOKS LIKE A 3-4 HOUR WINDOW AS TEMPERATURES WILL BE WARMING THROUGH THE NIGHT. LOOKS LIKE SHOWERS TAKE OVER WITH EVEN A CHANCE OF A RUMBLE OR TWO OF THUNDER IN THE 3-6AM TIME FRAME WITH 850MB MOISTURE TRANSPORT MAXIMIZING AND AS MID-LEVEL PV-ANOMALY/SURFACE LOW/COLD FRONT APPROACH FROM MN. WILL HAVE TO WATCH HIGH TEMPERATURES TODAY IN FILTERED SUNSHINE. HAVE MID 30S-LOWER 40S GOING NOW...BUT COULD END UP BEING A FEW DEGREES WARMER IF SUN FILTERS THROUGH ENOUGH. FRIDAY WILL SEE MAINLY MORNING TO EARLY AFTERNOON SHOWER CHANCES AS THE LOW AND COLD FRONT SWING THROUGH. THERE WILL ALSO BE A SLIGHT CHANCE OF A FEW MORNING THUNDERSTORMS AS WELL. OTHERWISE...LOOKS LIKE WE BREAK OUT IN ALMOST FULL SUNSHINE BY AFTERNOON WITH A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING LOW/COLD FRONT. THIS SHOULD ALLOW FOR DECENT MIXING. THIS LOOKS TO TAP SOME FAIRLY STRONG WINDS WITH NAM/GFS BUFKIT SHOWING 40-50KT ONLY 0.5KM AGL. RIGHT NOW...LOOKING LIKE SUSTAINED WESTERLY WINDS OF 20-30MPH WITH GUSTS 35 TO 40 MPH...POSSIBLY CLOSING IN ON 50 MPH IN THE MORE WIND PRONE AREAS OF NORTHEAST IA/SOUTHEAST MN AND HIGHER TERRAIN/BLUFF TOPS ALONG THE MISSISSIPPI RIVER. LOOKING LIKELY WE WILL EVENTUALLY NEED A WIND ADVISORY HEADLINE BASED ON THIS. OTHERWISE...A COLD FRONT PASSED THROUGH...MIXING OF PLAINS DOWNSLOPED AIR BEHIND THIS SYSTEM SHOULD PUSH HIGHS WELL INTO THE 40S WITH A FEW LOWER 50S ACROSS NORTHEAST IA INTO SOUTHWEST WI. STRATUS CLOUDS FILL BACK IN FROM NORTHWEST TO SOUTHEAST INTO THE AREA FRIDAY NIGHT BUT REMAINING RELATIVELY MILD WITH LOWS ONLY FALLING INTO THE LOWER/MIDDLE 30S. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 321 AM CST THU FEB 18 2016 HIGH ZONAL FLOW ACROSS THE NORTHERN CONUS FOR SATURDAY INTO SUNDAY. THIS USHERS IN A WEAK MID-LEVEL TROUGH WITH A SMALL CHANCE OF SNOW LATE SATURDAY NIGHT AND MOSTLY RAIN CHANCES SUNDAY AS TEMPERATURES WARM INTO THE MIDDLE 30S TO LOWER 40S. MONDAY THROUGH WEDNESDAY LOOKING DRY AND A BIT COOLER/BACK TO NEAR NORMAL AS UPPER LEVEL TROUGHING CARVES INTO THE CENTRAL CONUS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1140 AM CST THU FEB 18 2016 VERY TRICKY AVIATION FORECAST AHEAD WITH AN ALL OR NOTHING TYPE LOOK TO IT. WARM AIR ADVECTION AND GENERAL SATURATION CONTINUES AS LIFT AHEAD OF APPROACHING WAVE CONTINUES TODAY AND INTO TONIGHT. ALREADY SEEING A NARROW STRIP OF IFR CONDITIONS ACROSS THE AREA BUT THIS HAS BEEN IN AND OUT AS DRYNESS OF CURRENT AIRMASS BATTLES SATURATION. UNSURE ON HOW LONG THIS STRATUS LAYER WILL STAY IN TACT TODAY SO WILL RIDE A MORE OPTIMISTIC VIEW WITH MORE VFR CONDITIONS...BUT WATCH TRENDS FOR ANY EXPANSION TO STRATUS DECK. GOING INTO THIS EVENING STILL SEEING SIGNS OF LOW LEVEL MOISTURE INCREASING AND LOOKING FOR EXPANSION OF STRATUS AND FOG AS STRONG WARM AIR ADVECTION REMAINS IN PLACE. MOST AREAS WILL LIKELY SEE IFR CONDITIONS. AS STRONG WAVE PASSES FRIDAY MORNING...DRIER AIR AND SUBSIDENCE SHOULD CLEAR CONDITIONS QUICKLY FROM WEST TO EAST. STRONG CORE OF WINDS BEHIND WAVE WILL ALSO BEEN STRONG WINDS FOR A PERIOD LATE IN TAFS. && .HYDROLOGY... ISSUED AT 321 AM CST THU FEB 18 2016 WITH CLIMBING TEMPERATURES INTO THE WEEKEND...SIGNIFICANT SNOW MELT WILL TAKE PLACE...MELTING A 1-2 INCH WATER EQUIVALENT SNOWPACK WHICH WILL ENTER THE RIVERS. A FEW MODELS SHOWING A COMPLETE MELT OF THIS SNOWPACK. AS A RESULT...EXPECT RIVER RISES AND THE POSSIBILITY OF ICE BREAKUP ON STREAMS/RIVERS. A FEW ICE JAMS COULD RESULT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WIND ADVISORY FROM 9 AM TO 6 PM CST FRIDAY FOR WIZ032>034- 041>044-053>055-061. MN...WIND ADVISORY FROM 6 AM TO 6 PM CST FRIDAY FOR MNZ079-086>088- 094>096. IA...WIND ADVISORY FROM 6 AM TO 6 PM CST FRIDAY FOR IAZ008>011-018- 019-029-030. && $$ UPDATE...BAUMGARDT SHORT TERM...DAS LONG TERM...DAS AVIATION...SHEA HYDROLOGY...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 AM CST THU FEB 18 2016 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 321 AM CST THU FEB 18 2016 SURFACE MAP SHOWS DEEP LOW PRESSURE MOVING EASTWARD OUT OF MONTANA WITH A WARM FRONT ARCHING THROUGH SD INTO EASTERN NE AND WESTERN MO. IR SATELLITE SHOWS A BAND OF ALTOSTRATUS IN ADVANCE OF THIS WARM FRONT COVERING ALL OF THE FORECAST AREA. COMBINATION OF CLOUD COVER AND LIGHT SOUTHEAST WINDFLOW KEEPING TEMPERATURES IN CHECK IN THE UPPER TEENS TO THE MIDDLE 20S AS OF 2 AM. SOUTHERLY FLOW PICKS UP TODAY INTO TONIGHT AS THE AREA OF LOW PRESSURE AND WARM FRONT APPROACH THE REGION. RAP BUFKIT SHOWS MOSTLY MID/HIGH CLOUD OVER THE AREA TODAY WITH STRATUS HOLDING OFF TO THE WEST...HOWEVER AS THE WARM FRONT APPROACHES THIS EVENING/OVERNIGHT... LOWEST 1.5KM OF COLUMN QUICKLY SATURATES LEADING TO WIDESPREAD STRATUS. LIFT/TURNING THROUGH THIS STRATUS WILL LEAD TO AREAS OF DRIZZLE WITH THE POSSIBILITY OF A LITTLE FREEZING DRIZZLE NORTH OF HIGHWAY 10 IN NORTH CENTRAL WI. ONLY LOOKS LIKE A 3-4 HOUR WINDOW AS TEMPERATURES WILL BE WARMING THROUGH THE NIGHT. LOOKS LIKE SHOWERS TAKE OVER WITH EVEN A CHANCE OF A RUMBLE OR TWO OF THUNDER IN THE 3-6AM TIME FRAME WITH 850MB MOISTURE TRANSPORT MAXIMIZING AND AS MID-LEVEL PV-ANOMALY/SURFACE LOW/COLD FRONT APPROACH FROM MN. WILL HAVE TO WATCH HIGH TEMPERATURES TODAY IN FILTERED SUNSHINE. HAVE MID 30S-LOWER 40S GOING NOW...BUT COULD END UP BEING A FEW DEGREES WARMER IF SUN FILTERS THROUGH ENOUGH. FRIDAY WILL SEE MAINLY MORNING TO EARLY AFTERNOON SHOWER CHANCES AS THE LOW AND COLD FRONT SWING THROUGH. THERE WILL ALSO BE A SLIGHT CHANCE OF A FEW MORNING THUNDERSTORMS AS WELL. OTHERWISE...LOOKS LIKE WE BREAK OUT IN ALMOST FULL SUNSHINE BY AFTERNOON WITH A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING LOW/COLD FRONT. THIS SHOULD ALLOW FOR DECENT MIXING. THIS LOOKS TO TAP SOME FAIRLY STRONG WINDS WITH NAM/GFS BUFKIT SHOWING 40-50KT ONLY 0.5KM AGL. RIGHT NOW...LOOKING LIKE SUSTAINED WESTERLY WINDS OF 20-30MPH WITH GUSTS 35 TO 40 MPH...POSSIBLY CLOSING IN ON 50 MPH IN THE MORE WIND PRONE AREAS OF NORTHEAST IA/SOUTHEAST MN AND HIGHER TERRAIN/BLUFF TOPS ALONG THE MISSISSIPPI RIVER. LOOKING LIKELY WE WILL EVENTUALLY NEED A WIND ADVISORY HEADLINE BASED ON THIS. OTHERWISE...A COLD FRONT PASSED THROUGH...MIXING OF PLAINS DOWNSLOPED AIR BEHIND THIS SYSTEM SHOULD PUSH HIGHS WELL INTO THE 40S WITH A FEW LOWER 50S ACROSS NORTHEAST IA INTO SOUTHWEST WI. STRATUS CLOUDS FILL BACK IN FROM NORTHWEST TO SOUTHEAST INTO THE AREA FRIDAY NIGHT BUT REMAINING RELATIVELY MILD WITH LOWS ONLY FALLING INTO THE LOWER/MIDDLE 30S. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 321 AM CST THU FEB 18 2016 HIGH ZONAL FLOW ACROSS THE NORTHERN CONUS FOR SATURDAY INTO SUNDAY. THIS USHERS IN A WEAK MID-LEVEL TROUGH WITH A SMALL CHANCE OF SNOW LATE SATURDAY NIGHT AND MOSTLY RAIN CHANCES SUNDAY AS TEMPERATURES WARM INTO THE MIDDLE 30S TO LOWER 40S. MONDAY THROUGH WEDNESDAY LOOKING DRY AND A BIT COOLER/BACK TO NEAR NORMAL AS UPPER LEVEL TROUGHING CARVES INTO THE CENTRAL CONUS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1140 AM CST THU FEB 18 2016 VERY TRICKY AVIATION FORECAST AHEAD WITH AN ALL OR NOTHING TYPE LOOK TO IT. WARM AIR ADVECTION AND GENERAL SATURATION CONTINUES AS LIFT AHEAD OF APPROACHING WAVE CONTINUES TODAY AND INTO TONIGHT. ALREADY SEEING A NARROW STRIP OF IFR CONDITIONS ACROSS THE AREA BUT THIS HAS BEEN IN AND OUT AS DRYNESS OF CURRENT AIRMASS BATTLES SATURATION. UNSURE ON HOW LONG THIS STRATUS LAYER WILL STAY IN TACT TODAY SO WILL RIDE A MORE OPTIMISTIC VIEW WITH MORE VFR CONDITIONS...BUT WATCH TRENDS FOR ANY EXPANSION TO STRATUS DECK. GOING INTO THIS EVENING STILL SEEING SIGNS OF LOW LEVEL MOISTURE INCREASING AND LOOKING FOR EXPANSION OF STRATUS AND FOG AS STRONG WARM AIR ADVECTION REMAINS IN PLACE. MOST AREAS WILL LIKELY SEE IFR CONDITIONS. AS STRONG WAVE PASSES FRIDAY MORNING...DRIER AIR AND SUBSIDENCE SHOULD CLEAR CONDITIONS QUICKLY FROM WEST TO EAST. STRONG CORE OF WINDS BEHIND WAVE WILL ALSO BEEN STRONG WINDS FOR A PERIOD LATE IN TAFS. && .HYDROLOGY... ISSUED AT 321 AM CST THU FEB 18 2016 WITH CLIMBING TEMPERATURES INTO THE WEEKEND...SIGNIFICANT SNOW MELT WILL TAKE PLACE...MELTING A 1-2 INCH WATER EQUIVALENT SNOWPACK WHICH WILL ENTER THE RIVERS. A FEW MODELS SHOWING A COMPLETE MELT OF THIS SNOWPACK. AS A RESULT...EXPECT RIVER RISES AND THE POSSIBILITY OF ICE BREAKUP ON STREAMS/RIVERS. A FEW ICE JAMS COULD RESULT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...SHEA HYDROLOGY...DAS