Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/26/14


AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
803 PM MST TUE FEB 25 2014 .UPDATE... ISSUED AT 803 PM MST TUE FEB 25 2014 SNOTELS IN THE NORTHERN MOUNTAINS INDICATED ACCUMULATIONS HAD ENDED AT MOST LOCATIONS AND ONLY BUFFALO PARK HAD PICKED UP ANY MEASURABLE ACCUMULATION IN THE PAST COUPLE OF HOURS. SATELLITE INDICATED THAT THE TROUGH AXIS HAD EXITED THE ADVISORY AREA. CONSEQUENTLY...CONFIDENT SHORT RANGE MODELS ARE CORRECT IN PRODUCING LITTLE TO NO ADDITIONAL SNOWFALL IN THE ELKHEAD AND PARK RANGES. THEREFORE...WENT AHEAD AND CANCELLED THE WINTER WEATHER ADVISORY WHICH WAS IN EFFECT FOR THE AREA THROUGH WEDNESDAY MORNING. && .SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT) ISSUED AT 252 PM MST TUE FEB 25 2014 SHORT TERM FORECAST THROUGH THIS EVENING IS BASED ON RAP MODEL TRENDS THAT SNOW WILL EXPAND SOUTHWARD OVER ROUTT COUNTY EARLY THIS AFTERNOON. AS OF 21Z...STEAMBOAT LAKE WEB CAM INDICATE THAT SNOW HAS REACHED HAHNS PEAK VICINITY...BUT NO MOUNTAIN TOP OBSCURATION NEAR STEAMBOAT SPRINGS. EXPECT THIS TO CHANGE WITHIN THE NEXT COUPLE OF HOURS AS LEADING EDGE OF BAROCLINIC ZONE AND DECENT GRADIENT NORTHWEST FLOW LEADS TO OROGRAPHIC SNOW OVER THE MT ZIRKEL WILDERNESS AREA AND THE PARK RANGE. RAP MODEL INDICATES RAIN/SNOW BAND MAY EXTEND AS FAR WEST AS MAYBELL AND MEEKER LATE THIS AFTERNOON AS THE MOISTURE BAND SLIDES SOUTH AND EAST. PRIMARY CONCERN IS THAT THE AMPLIFYING UPSTREAM RIDGE AXIS HAS PINCHED OFF THE PACIFIC MOISTURE STREAM INTO NORTHWEST COLORADO... THIS IS EVIDENT ON THE SATELLITE IMAGES. NOT SURE WHETHER THE FORECASTED SNOW AMOUNTS FOR THE PARK RANGE WILL REACH THE UPPER RANGE OF AROUND 7 INCHES...BUT RAP QPF STILL INDICATE THAT A FEW INCHES OF SNOW REMAIN POSSIBLE. WITH SNOW OBSERVED AT RIVERTON AND LANDER IN WEST CENTRAL WYOMING...GIVING CREDENCE THAT THE SNOW IS ON THE WAY. LESSER AMOUNTS OF SNOW IS ANTICIPATED FOR THE FLAT TOP MOUNTAINS AND GORE RANGE (VAIL PASS)...DO NOT THINK THAT AN EXPANSION OF THE WINTER WEATHER ADVISORY IS NECESSARY. MOISTURE STREAM SLIDES EAST AFTER MIDNIGHT WITH MID LEVEL DRY STABLE AIR ADVECTING INTO NORTHWEST COLORADO...THIS WILL SHUT DOWN OROGRAPHIC SNOW FAIRLY QUICKLY LATE TONIGHT. FOR THE SERN HALF OF THE FORECAST AREA THROUGH TONIGHT...CLEAR AND DRY WEATHER IS EXPECTED FOR THE NEXT 12 TO 18 HOURS. WEST COAST RIDGE SHIFTS INLAND ON WEDNESDAY BUT BROAD ISENTROPIC UPGLIDE WILL RESULT IN AN INCREASE OF MID/HIGH LEVEL CLOUDS FROM THE SOUTHWEST. NAM AND GFS SHOWING HINTS OF MOUNTAIN TOP SPOTTY SNOW WEDNESDAY AFTERNOON AND NIGHT. SOMETIMES THIS IS OVERDONE BUT THE TREND WILL BE FOR INCREASING CLOUDS WITH CIRROSTRATUS EVOLVING INTO ALTOSTRATUS. WITH THE INCREASED CLOUD COVER...EXPECT RELATIVELY MILD CONDITIONS WEDNESDAY NIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 252 PM MST TUE FEB 25 2014 THE FORECAST AREA COMES UNDER THE INFLUENCE OF THE SUBTROPICAL JET THROUGH THE WEEKEND. THIS TYPICALLY BRINGS BETTER MOISTURE BUT MILDER TEMPERATURES WITH ASSOCIATED STORMS. BREEZY TO WINDY CONDITIONS ARE EXPECTED IN THE MTNS AND HIGH VALLEYS...INTO THE LOWER VALLEYS WITH SHOWERS. THURSDAY...A TRANSIENT RIDGE PASSES IN THE EARLY AFTERNOON WITH DEEPENING MOISTURE IN SW FLOW. 700MB SPECIFIC HUMIDITIES CLIMB TO 4 G/KG IN THE AFTERNOON. THERE IS SOME MODEL DISAGREEMENT ON TEMPERATURES AND SNOW LEVELS. A COMPROMISE PUTS THE SNOW LEVELS AROUND 7500FT/8500FT NORTH/SOUTH. THE DEEPEST MOISTURE IS IN THE SOUTHERN-CENTRAL MTNS. MARGINAL INSTABILITY PRODUCES AREAS OF STRONGER SHOWERS AND BRIEFLY LOWER SNOW LEVELS. THURSDAY NIGHT...THE BEST FORCING OCCURS AS THE SUBTROPICAL JET PUSHES INTO THE SOUTH THEN LIFTS INTO THE CENTRAL ZONES. SNOW LEVELS LOWER INTO THE NORTHERN VALLEYS...TO 7500FT SOUTH. FRIDAY IS A BRIEF BREAK UNDER AS A LOCAL RIDGE IS AMPLIFIED AHEAD OF THE NEXT STRONG STORM BRINGING WARM ADVECTION. MOISTURE REMAINS AT 4 G/KG SO SHOWERS INCREASE INTO THE AFTERNOON. FRIDAY NIGHT-SATURDAY NIGHT...THE NEXT SUBTROPICAL JET STREAK LIFTS THE EASTERN UTAH FRIDAY NIGHT THEN ACROSS WESTERN COLORADO ON SATURDAY. AGAIN THERE IS A CONVECTIVE COMPONENT FRIDAY NIGHT INTO SATURDAY. THERE IS AGAIN A CONVECTIVE COMPONENT TO THIS STORM. SNOWFALL WILL FAVOR THE SOUTHERN AND CENTRAL MTNS. SNOW LEVELS AROUND 7000FT. SATURDAY NIGHT IS TROUGH PASSAGE WITH NW FLOW DEVELOPING. SNOW LEVEL DROPS TO AROUND 5000FT BUT WILL FAVOR THE NW-FACING SLOPES OF THE COLORADO MTNS. SUNDAY-TUESDAY...ARE NOW A FLAT ZONAL FLOW WITH THE POLAR FRONT JET SETTLING INTO WYOMING THEN RAKING THE NORTH ON MONDAY. EXPECT COOLER TEMPERATURES THROUGH THESE PERIODS WITH THE BEST SNOWFALL FAVORING THE NORTHERN MTNS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 252 PM MST TUE FEB 25 2014 VFR PREVAILS AT ALL TAF SITES THROUGH THE PERIOD. THERE IS A 10 TO 20 PERCENT CHANCE OF -SN AT KASE AND KEGE BETWEEN 00Z AND 12Z TONIGHT. WIDESPREAD LIGHT SNOW IS EXPECTED EAST OF A LINE FROM DWX-KSBS-10E KEGE-10E KASE FROM 20Z THIS AFTERNOON THROUGH 06Z THIS EVENING. EXPECT MOUNTAIN OBSCURATIONS WITH LOW CIGS/VIS FROM LIGHT SNOW AND FOG. SLOW IMPROVEMENT IS EXPECTED AFTER 06Z WITH NO MOUNTAIN OBSCURATIONS AFTER 15Z. MID/HIGH LEVEL CLOUDS INCREASE ON WEDNESDAY WITH ISOLATED MOUNTAIN TOP FLURRIES. THIS SHOULD HAVE NO IMPACT AT MOUNTAIN AIRPORT SITES. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...NL SHORT TERM...PF LONG TERM...JOE AVIATION...PF
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1025 AM MST MON FEB 24 2014 .UPDATE... && .SHORT TERM...FOG HAS BEEN STEADILY DISSIPATING ACROSS THE NORTHEAST PLAINS...WITH INCREASED VISIBILITIES. STILL A WEAK CYCLONE NORTH OF DENVER KEEPING LOW CLOUDS AND FOG IN AN AREA FROM NORTH OF BOULDER TO FORT COLLINS EASTWARD ACROSS CENTRAL WELD AND MORGAN COUNTIES. VISIBILITIES IN THIS AREA AROUND A MILE. ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 9AM. FOG WILL GRADUALLY DISSIPATE THROUGH THE MORNING AS WEST NORTHWEST FLOW ALOFT MIXES TO THE SURFACE WITH GUSTY WINDS SPREADING OFF THE FOOTHILLS. LATEST MODELS SHOW THE NEXT FRONTAL SURGE MOVING ACROSS THE PLAINS AFTER 20Z...REACHING DENVER AROUND 23Z WITH A SHIFT IN THE WINDS TO THE NORTHEAST. FRONT LOOKS TO BE NEAR CASPER AT THIS TIME. CURRENT FORECASTS HAVE SIMILAR THINKING THOUGH MAY DELAY THE WIND SHIFT AN HOUR OR TWO. LOW CLOUDS AND STRATUS LOOK TO DEVELOP AROUND 00Z. CHANCE FOR SNOW ACROSS THE MOUNTAINS THIS EVENING WITH APPROACHING TROUGH AND LIFT. WON`T CHANGE MUCH TO ONGOING FORECASTS AT THIS TIME. WILL BOOST TEMPERATURES A BIT ACROSS THE DENVER AREA BASED ON CURRENT READINGS. .AVIATION...WESTERLY WINDS OFF FOOTHILLS HAVE PUSHED ACROSS THE DENVER AREA WITH GUSTS TO 26 KTS. LATEST RAP AND HRRR SHOW THE WINDS SHIFTING TO THE NORTHWEST AT 18Z. MAY DELAY THIS WIND SHIFT AN HOUR BASED ON CURRENT CONDITIONS. OTHERWISE CURRENT TAF TRENDS SEEM ON TRACK. FRONT LOOKS TO MOVE ACROSS THE DENVER AREA AROUND 23Z...WILL DELAY THIS WIND SHIFT AN HOUR. IFR CONDITIONS TO DEVELOP BY 01Z BEHIND THE FRONT WITH SNOW POSSIBLE LATE TUESDAY MORNING...CONTINUING THROUGH THE AFTERNOON. AT THIS TIME...IT LOOKS LIKE AROUND AN INCH OF ACCUMULATION BY TUESDAY EVENING. && .PREV DISCUSSION... /ISSUED 400 AM MST MON FEB 24 2014/ SHORT TERM...SHALLOW FOG/STRATUS LAYER COVERS THE PLAINS EXCEPT FOR A LITTLE HOLE IN DOWNSLOPE OVER DOUGLAS AND ELBERT COUNTIES. SOME SIGNS OF STIRRING IN THIS LAYER AS WINDS ON THE PLAINS INCREASE...SURFACE VISIBILITIES HAVE STARTED TO COME UP IN SOME AREAS THIS LAST HOUR. HOWEVER A WEAK DENVER CYCLONE REMAINS IN PLACE WITH LIGHT WINDS IN THE SOUTH PLATTE VALLEY AND WEST TOWARD THE FOOTHILLS. NO REAL CLEARING FROM THE WEST YET...WEST WINDS ARE CREEPING INTO THE LOWER FOOTHILLS SOUTH OF BOULDER...BUT MAKING LESS PROGRESS FURTHER NORTH PROBABLY DUE TO SOME HELP FROM THE CYCLONE CIRCULATION AND THE SE GRADIENT ON THE PLAINS. ALREADY DELAYED CLEARING IN THE DENVER AREA A COUPLE OF HOURS. EXTENDED THE DENSE FOG ADVISORY UNTIL 9 AM...THINGS WILL PROBABLY BE BETTER IN DENVER A COUPLE HOURS EARLIER...BUT NOT SURE THERE WILL BE MUCH IMPROVEMENT IN FORT COLLINS/LONGMONT/GREELEY TRIANGLE. COMPLICATED SCENARIO FOR THE REST OF THE DAY AS WELL...AND LOW CONFIDENCE THAT THE MODELS HAVE A GOOD HANDLE ON ALL THINGS HAPPENING NEAR THE SURFACE. PLAINS SOUTHERLIES WILL TRY TO MAINTAIN THE CURRENT SITUATION UNDER A STRONG INVERSION. MEANWHILE WESTERLIES IN A WEAK MOUNTAIN WAVE WILL BE TRYING TO BREAK THROUGH THE WEST EDGE OF THE COLD AIR. STILL THINK THE WESTERLIES WILL PUSH OFF THE FOOTHILLS...AT LEAST INTO DENVER BUT AGAIN LESS CERTAINTY FURTHER NORTH. WE MAY WIND UP WITH TWO OR THREE AREAS OF CHANNELED WESTERLIES WITH COLD AIR IN THE VALLEYS IN BETWEEN. THEN A FEATURE THAT IS NOT WELL REPRESENTED IN THE MODELS NOW ACROSS SOUTHERN WYOMING SHOULD MOVE OVER DENVER AROUND MIDDAY. THIS WILL LIKELY BRING A SHIFT TO A MORE NW WIND DIRECTION IN THE WARMER AIR AND BRING SLIGHT COOLING. IT MAY ALSO INITIATE A PREFRONTAL SOUTHWESTWARD SURGE IN THE COLD AIR. THEN THE REAL FRONT WILL PUSH SOUTH LATER IN THE AFTERNOON. THIS APPEARS TO HAVE A PRETTY GOOD PRESSURE WAVE BUILDING UP...WE WILL NOT HAVE THE NEAR ZERO AIR THAT IS BEHIND THE BOUNDARY NOW...BUT STILL A PRETTY STOUT LITTLE WAVE OF WIND AND TEMPERATURE GRADIENT WILL COME THROUGH IN THE LATE AFTERNOON AND EARLY EVENING. THEN BACK TO LIGHTER EASTERLY WINDS BY MIDNIGHT OR SO. TOO MUCH TO TRY TO PIN DOWN ALL THESE LITTLE DETAILS EXACTLY...BUT EVEN THE WARM AIR SHOULD NOT BE QUITE AS WARM AS WE EXPECTED AND THE EARLIER SURGE AND SLIGHTLY EARLIER TIMING OF THE REAL FRONT MEANS I NEED TO TRIM TEMPERATURES FOR TODAY. I SUBTRACTED A FEW DEGREES IN THE WARMER AIR...AND MOVED THE NORTH/SOUTH GRADIENT SOUTHWARD AS WELL...THEN SHOWED A BIT MORE COOLING LATE IN THE DAY. WITH THE DRY AIR ALOFT SIGNIFICANT SNOW DOES NOT LOOK LIKELY...BUT THE STRATUS WILL RETURN WITH THE FRONT AND THERE COULD BE SOME FLURRIES WITH IT...AT THIS POINT THE EXISTING POPS SEEM ALRIGHT. LONG TERM...AN UPPER LEVEL TROUGH WILL MOVE ACROSS NRN CO TUE AFTN INTO TUE EVENING. MEANWHILE A STG CDFNT WILL MOVE ACROSS NERN CO BY MIDDAY ENHANCING UPSLOPE FLOW. CROSS-SECTIONS SHOW DECENT MOISTURE IN THE MTNS TUE AFTN INTO EARLY TUE EVENING WITH DECENT OROGRAPHICS SO SHOULD SEE A PERIOD OF SNOW WITH CLOSE TO ADVISORY AMOUNTS IN SOME AREAS. OVER NERN CO COMBINATION OF INCREASING UPSLOPE FLOW...SOME MDT MID LVL QG ASCENT AND POTENTIAL CSI SHOULD LEAD TO A GOOD CHANCE OF SNOW BY EARLY TUE AFTN NR THE WY-NE BORDER WHICH WILL SPREAD SOUTHWARD ACROSS THE PLAINS BY LATE AFTN. APPEARS SNOW SHOULD GRADUALLY END BY EARLY TUE EVENING FM NORTH TO SOUTH AS AS UPSLOPE FLOW WEAKENS AND DRIER AIR SPREADS ACROSS. OVERALL AMOUNTS WILL BE IN THE 1 TO 3 INCH RANGE ALTHOUGH BANDED PCPN COULD LEAD TO SOME 2 TO 4 INCH AMOUNTS IN SOME PLACES. HIGHS ON TUE WILL OCCUR IN THE MORNING AND THEN STEADILY DROP IN THE AFTN AS COLDER AIR MOVES IN BEHIND COLD FNT. FOR WED MAINLY DRY WNW FLOW ALOFT WILL BE OVER THE AREA WITH ONLY A SLIGHT CHC OF SNOW IN THE MTNS. HIGHS SHOULD MODERATE SOME OVER NERN CO ALTHOUGH SNOW COVER COULD ALTER READINGS IN SOME AREAS ESPECIALLY OVER THE FAR NERN CORNER. WILL KEEP HIGHS IN THE MID TO UPPER 40S ALONG THE FRONT RANGE WITH UPPER 30S OVER THE FAR NERN CORNER. BY THU THE FLOW ALOFT WILL BECOME MORE WLY AS A WEAK UPPER LEVEL TROUGH MOVES ACROSS BY THU AFTN INTO THU NIGHT. CROSS- SECTIONS SHOW MOISTURE INCREASING OVER THE AREA WHICH SHOULD LEAD TO A GOOD CHANCE OF SNOW IN THE MTNS. AT LOWER ELEVATIONS SFC LOW PRES WILL EXTEND FM SCNTRL WY INTO SERN CO WITH INCREASING SELY LOW LVL FLOW OVER NERN CO AS COLDER AIR TRIES TO BACKDOOR INTO THE FAR NERN CORNER. AS THE WK UPPER LEVEL TROUGH MOVES ACROSS THU NIGHT THERE COULD BE A CHC OF SNOW ESPECIALLY OVER THE FAR NERN PLAINS. HIGHS ON THU MAY RISE INTO THE LOWER 50S NEAR DENVER HOWEVER OVER THE FAR NERN CORNER READINGS MAY HOLD IN THE 30S. BY FRI THE FLOW ALOFT WILL BE WLY WITH CROSS-SECTIONS SHOWING LIMITED MOISTURE OVER THE AREA SO WILL JUST MENTION A CHC OF LIGHT SNOW IN THE MTNS. AT LOWER ELEVATIONS BOTH THE ECMWF AND GFS SHOW A CDFNT BACKDOORING ACROSS MOST OF NERN CO BY AFTN WITH READINGS ONLY IN THE LOWER 30S ALONG THE WY-NE BORDER. CLOSER TO THE FOOTHILLS TEMP FCST WILL BE MORE DIFFICULT AS SHALLOW LYR OF COLD AIR BATTLES DOWNSLOPE WLY FLOW COMING OFF THE HIGHER TERRAIN. FOR NOW WILL KEEP READINGS IN THE LOWER TO MID 40S OVER DENVER. AS FOR PRECIP WILL MENTION A SLIGHT CHANCE OF SNOW ALONG THE WY-NE BORDER PUT KEEP THE REST OF THE PLAINS DRY. FOR SAT INTO SAT NIGHT AN UPPER LEVEL TROUGH MAY MOVE ACROSS THE AREA IN WLY FLOW ALOFT LEADING TO A GOOD CHANCE OF SNOW IN THE MTNS. AT LOWER ELEVATIONS THE LOW LEVEL FLOW EAST OF THE MTNS IS FCST TO BE SELY AS COLD SFC HIGH PRES SLIDES FM THE NRN ROCKIES INTO THE CNTRL PLAINS. IF THE FLOW IS SELY THAT WOULD KEEP THE BEST CHC OF SNOW NR THE WY-NE BORDER. HOWEVER IF THE FLOW ENDS UP MORE ELY THEN THAT WOULD ENHANCE PCPN CHANCES FURTHER SOUTH. FOR NOW WILL KEEP CHC POPS NEAR THE WY-NE BORDER WITH LOWER POPS FURTHER SOUTH. AS FOR HIGHS WILL HAVE READINGS IN THE LOWER TO MID 30S AROUND DENVER WITH ONLY LOWER TO MID 20S OVER THE FAR NERN CORNER. AVIATION...VISIBILITIES WILL CONTINUE TO IMPROVE OVER THE NEXT COUPLE HOURS WITH STRATUS DRIFTING OUT OF THE DENVER AREA BY 14Z. VFR CONDITIONS EXPECTED MOST OF THE DAY...THEN MVFR/IFR CONDITIONS REDEVELOPING BEHIND A COLD FRONT BETWEEN 22Z AND 02Z. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....RPK AVIATION...D-L
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1026 PM MST SUN FEB 23 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 300 PM MST SUN FEB 23 2014 CURRENTLY...LOW STRATUS HAS SLOWLY ERODED TO LEAVE SUNNY SKIES ACROSS SOUTHERN COLORADO THIS AFTERNOON. TEMPERATURES HAVE BEEN HIGHLY DEPENDENT ON WIND...WHERE ITS WESTERLY...TEMPERATURES HAVE WARMED INTO THE 40S TO LOW 50S...WHERE ITS EASTERLY THEY HAVE REMAINED IN THE 30S. EXPECT A COUPLE OF MORE DEGREES OF WARMING FOR MOST AREAS...WITH THE EXCEPTION OF THE I-25 CORRIDOR...WHERE RAPID WARM UPS ARE POSSIBLE AS WESTERLIES TRY AND MAKE IT EAST. TONIGHT...BROAD NORTHWEST FLOW WILL ENCOMPASS THE REGION THROUGH THE SHORT TERM. THE MAIN QUESTION WILL BE THE DEGREE OF LOW STRATUS SLOSHING BACK WEST ACROSS THE PLAINS TONIGHT. FOLLOWED THE HRRR AND LOCAL WRF...WHICH KEEPS STRATUS OUT ALONG THE KANSAS BORDER WITH LITTLE PROGRESSION WEST. THE CAVEAT WILL BE HOW QUICKLY LEE TROUGH DEVELOPS AND LOW LEVEL WESTERLY FLOW. BOTH THE HRRR AND WRF HAVE WESTERLIES PICKING UP BY MIDNIGHT AND SHIFTING CLEAR OUT TO THE KANSAS BORDER BY 10-11Z. THIS SHOULD ALLOW FOR RAPID CLEARING OF ANY STRATUS OUT EAST BY DAYBREAK. IF THE LEE TROUGHING IS SLOWER TO DEVELOP THAN MODELS PROJECT...STRATUS COULD MAKE IT MUCH FURTHER WEST AND IMPACT THE WARMING EXPECTED BY SUNRISE. OVERNIGHT LOWS WILL GENERALLY BE IN THE 20S ACROSS THE REGION...WITH SOME LOWER 30S FOR THE BANANA BELT. MONDAY...BROAD NORTHWEST FLOW ALOFT CONTINUES WITH DRY CONDITIONS FOR SOUTHERN COLORADO. THE MAIN CONCERNS WILL BE BREEZY AFTERNOON WINDS LEADING TO AREAS OF BLOWING DUST AND ELEVATED FIRE WEATHER CONCERNS. STRONG MIXING BY THE AFTERNOON WILL BRING WIDESPREAD WIND GUSTS TO NEAR 30 MPH ALONG THE LEE SLOPES...EAST INTO THE I-25 CORRIDOR. THESE GUSTY WINDS WILL LIKELY PRODUCE AREAS OF BLOWING DUST...ESPECIALLY IN DUST PRONE AREAS SOUTH AND NORTH OF PUEBLO...CREATING HAZARDOUS DRIVING CONDITIONS. IN ADDITION...HUMIDITY VALUES ARE EXPECTED TO FALL INTO THE 10-15 PERCENT RANGE...AND WHEN COMBINED WITH THE GUSTY WINDS...WILL PRODUCE DANGEROUS FIRE WEATHER CONDITIONS...PARTICULARLY ALONG THE SOUTHERN I-25 CORRIDOR. EXPECT THE MIXING TO HELP BOOST TEMPERATURES FOR TOMORROW WITH HIGHS TOPPING OUT IN THE LOWER TO MID 60S FOR THE LOWER ELEVATIONS. MOZLEY .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 300 PM MST SUN FEB 23 2014 ...ACTIVE WX PATTERN AS PACIFIC STORMS BEGIN TO AFFECT THE REGION... MON NITE-INTO WED... CANADIAN HIGH PRESSURE WILL AFFECT THE HI PLAINS DURING THIS TIME PERIOD WITH PERSISTENT UPSLOPE FLOW OVER THE PLAINS. A SHORTWAVE ALOFT IN THE NW FLOW WILL MOVE ACROSS TUE AFTERNOON/EVENING...AND THIS DISTURBANCE WILL BRING A CHANCE OF RAIN AND SNOW TO THE PLAINS. FOR NOW PAINTED POPS IN THE HIGH ISOLATED/LOW END SCATTERED CATEGORY. WITH THE MOIST UPSLOPE FLOW EXPECT AN EXTENDED PERIOD OF CLOUDINESS TO AFFECT THE PLAINS. BY LATER WED...SFC FLOW WILL TRANSITION TO SOUTHERLY AND THIS SHOULD DECREASE THE CLOUDINESS. THE ONLY POSSIBLE EXCEPTION WILL BE THE COS AREA WHERE THE SOUTHERLY FLOW MAY KEEP THE CLOUDS IN PLACE UNTIL LATE MORNING. PERSISTENT SNOW SHOWERS WILL BE POSSIBLE ACROSS THE C MTNS FROM MON NITE-EARLY WED THURSDAY... THE FIRST IN A SERIES OF PACIFIC WEATHER SYSTEMS WILL BEGIN TO AFFECT THE REGION. VALLEY RAIN SHOWERS AND SNOW IN THE MTNS WILL AFFECT THE CONTDVD BY THU LATE MORNING OR EARLY AFTERNOON AND INCREASE THU AFTERNOON AND NITE. GIVEN THE QUALITY MOISTURE...INSTABILITY...UPSLOPE FLOW AND FORCING...WE WILL LIKELY SEE SNOWFALL AMOUNTS REQUIRING HILITES (WINTER STORM WARNING?) FOR THE CONTDVD. LATE THU NITE INTO FRIDAY... UPSLOPE FLOW DEVELOPS ON THE PLAINS AND WE WILL SEE COOLER WX...CLOUDINESS AND A CHANCE OF SOME PRECIP RETURNING TO THE LOWER ELEVATIONS. WEEKEND... FRI NITE INTO EARLY SATURDAY A BRIEF RIDGE WILL BUILD ALOFT DECREASING THE CLOUDS AND ENDING THE PRECIP...BUT ANOTHER STRONGER PACIFIC STORM WILL BE QUICKLY MOVING IN. AS THIS PACIFIC STORM MOVES TOWARDS THE CONTDVD...ANOTHER REINFORCING CANADIAN HIGH PRESSURE SYSTEM WILL BE MOVING DOWN THE PLAINS...AND WILL BE AFFECTING THE LOWER ELEVATIONS BY LATER SATURDAY MORNING. SNOW WILL DEVELOP ONCE AGAIN OVER THE MTNS DURING THE DAY SATURDAY WITH PRECIP DEVELOPING ON THE PLAINS LATE SAT AFTERNOON/EVENING. GUIDANCE AT THIS TIME IS FAVORING THE PALMER DVD BUT I WOULD NOT BE TOO SURPRISED IF ALL OF THE PLAINS RECEIVE SOME PRECIP SAT NITE INTO SUNDAY AS THE MIDLVL TROUGH MOVES OVER THE REGION. OVERALL METEOROLOGICAL CONDITIONS FOR THIS WEEKENDS STORM LOOK PRETTY GOOD GIVEN THAT THE COLD AIR WILL ALREADY BE IN PLACE AS THE DYNAMICS MOVE OVER THE REGION. FOR NOW I GOT TEMPS IN THE 30S AND 40S FOR THE WEEKEND WITH SLIGHT/LOW END SCT POPS FOR THE AREA. I WOULD NOT BE TOO SURPRISED IF THE TEMPS ARE LOWERED AND THE POPS ARE INCREASED AS WE GET CLOSER TO THIS EVENT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1019 PM MST SUN FEB 23 2014 MVFR TO IFR STRATUS IS WORKING ITS WAY WESTWARD ACROSS SOUTHEAST CO TONIGHT. FORECAST MODELS TYPICALLY HAVE A TOUGH TIME FORECASTING WESTWARD EXTENT AND BASED ON TRENDS IN LATEST SATELLITE FOG PRODUCT AND IN RAP13...HAVE PUT A TEMPO GROUP FOR BKN010 AT KCOS...AND A PREVAILING MVFR CIG (BKN015) AT KPUB. ITS POSSIBLE STRATUS DECK COULD STALL OUT TO THE EAST OF THE KCOS TERMINAL...AND GIVEN THE UNCERTAINTY DECIDED TO KEEP IT IN A TEMPO GROUP FOR NOW. ONCE WINDS SHIFT OUT OF THE NORTH...THAT SHOULD ERODE IT AWAY FROM KCOS FAIRLY EARLY MONDAY MORNING (10Z)...AND AN HOUR OR SO LATER (11Z) AT KPUB. GUSTY WEST TO NORTHWEST WINDS WILL KICK IN AT KPUB AROUND 18Z ON MONDAY WITH WINDS REMAINING A LITTLE LIGHTER FOR KCOS. A COLD FRONT WILL MOVE THROUGH SE CO MONDAY EVENING AND HAVE IT TIMED TO PASS THROUGH KCOS AROUND 04Z AND KPUB AROUND 05Z BRINGING A PERIOD OF GUSTY NORTHEAST WINDS. KALS WILL REMAIN VFR WITH WIND SPEEDS 10 KTS OR LESS THROUGH THE NEXT 24 HOURS. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM 10 AM MST MONDAY THROUGH MONDAY AFTERNOON FOR COZ228>230. && $$ SHORT TERM...MOZLEY LONG TERM...HODANISH AVIATION...KT
AREA FORECAST DISCUSSION
NWS ALBANY NY
424 PM EST MON FEB 24 2014 .SYNOPSIS... AN ARCTIC AIR MASS WILL BE IN PLACE THIS WEEK WITH BELOW NORMAL TEMPERATURES. A SERIES OF DISTURBANCES ASSOCIATED WITH AN UPPER LEVEL LOW WILL PRODUCE SCATTERED SNOW SHOWERS AND FLURRIES INTO THE MID WEEK. A CLIPPER LOW ON WEDNESDAY WILL PRODUCE MORE WIDESPREAD SNOW SHOWERS...AS IT PASSES ACROSS THE SOUTHERN QUEBEC AND NORTHERN NEW YORK BORDER...WITH A REINFORCING SHOT OF ARCTIC AIR. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 423 PM EST...A BROAD H500 UPPER LEVEL LOW WILL IMPACT THE NORTHEAST THROUGH THE WEEK WITH SEVERAL SURGES OF ARCTIC AIR. THE UPPER LEVEL TROUGH IS AN EXTENSION OF THE POLAR VORTEX. ONE CLOSED H500 CIRCULATION IS OVER N-CNTRL QUEBEC. ANOTHER POTENT SHORT-WAVE MOVING S/SE IN THE TROUGH IS APPROACHING FROM NEAR ND/NW MN BASED ON THE LATEST WV LOOP. SOME OF THE SHORT-WAVE ENERGY FROM THE DISTURBANCE WILL BE THE CLIPPER FOR LATE TUE NIGHT INTO WED TO IMPACT THE REGION. CYCLONIC FLOW ALOFT WILL DOMINATE WITH SEVERAL SFC TROUGHS MOVING THROUGH THE LONGWAVE TROUGH. ONE MOVED THROUGH THE REGION THIS AFTERNOON WITH MAINLY DIFFUSE ACTIVITY DUE TO THE STEEP MID LEVEL LAPSE RATES...AS H500 TEMPS ARE IN THE -35C TO -37C RANGE. THERE WAS AN ORGANIZED BAND OF SNOW SHOWERS THAT WAS IMPACTING THE WRN MOHAWK VALLEY THAT BROKE UP AS IT MOVED EAST. THE LAKE EFFECT SNOW ADVISORY WAS CANCELLED FOR NRN HERKIMER CTY...SINCE THE BEST ORGANIZED LAKE BAND LATE THIS AFTERNOON AND TONIGHT LOOKS TO IMPACT SRN HERKIMER CTY. THE INVERSION HEIGHTS ARE MARGINAL UPSTREAM AT KSYR/KRME/KUCA AT 6-7 KFT AGL WITH A 280-290 DEG LOW-LEVEL TRAJ. THE INSTABILITY CLASS IS CONDITIONAL TO MODERATE WITH THE POSSIBILITY OF A LAKE BAND EXTENDING DOWNSTREAM INTO SRN HERKIMER SUPPORTED BY THE LOCAL HIRESWRF COLUMNAR REF PRODUCT BTWN 21Z-03Z. THE LATEST HRRR 3-KM REF PRODUCT ALSO KEYS INTO THIS AREA. AN ADDITIONAL 2 TO 6 INCHES IS POSSIBLE FOR PORTIONS OF SOUTHERN HERKIMER CTY...WITH TOTALS OF 3 TO 8 INCHES MENTIONED IN THE STATEMENT. ONLY AN ADDITIONAL INCH OR TWO IS POSSIBLE FOR THE WRN DACKS...AND MOSTLY OF THE OPEN CELLULAR SNOW SHOWER ACTIVITY. GENERALLY...SLIGHT TO LOW CHC POPS HAVE BEEN USED PRIOR TO MIDNIGHT NORTH AND WEST OF THE MID HUDSON VALLEY AND NW CT...WITH THE BEST CHCS OF SNOW SHOWERS WEST OF THE HUDSON RIVER VALLEY AFTER MIDNIGHT. H850 TEMPS WILL BE IN THE -17C TO -20C RANGE WITH THE COLD ADVECTION IN THE WAKE OF THE SFC TROUGH. EXPECT LOWS TO BE IN THE UPPER SINGLE DIGITS AND TEENS FROM THE CAPITAL DISTRICT SOUTH AND EAST...WITH SINGLE DIGITS TO A FEW BELOW ZERO READINGS /SRN DACKS/ OVER THE NRN TIER. BRISK W/NW WINDS WILL GENERATE WIND CHILLS 10 TO 15 BELOW ZERO OVER THE SRN DACKS...AND GENERALLY 5 BELOW TO 5 ABOVE IN MOST OTHER LOCATIONS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... TUESDAY...ANY ORGANIZED LAKE EFFECT ACTIVITY DIMINISHES DUE TO THE LOWERING INVERSION. HOWEVER...LAKE MOISTURE WILL STILL BE UTILIZED...AS A WEAK MID LEVEL DISTURBANCE MAY FOCUS ISOLATED TO SCATTERED SNOW SHOWERS AGAIN DURING DURING THE MORNING INTO THE AFTERNOON...WITH THE BETTER CHANCE OF SNOWFALL IN THE AFTERNOON ALONG THE WRN SPINE OF THE WRN DACKS...SRN GREENS...NRN-CNTRL TACONICS AND BERKSHIRES. THE WESTERLY UPSLOPE SNOW SHOWERS AND FLURRIES MAY PRODUCE LIGHT SNOW AMOUNTS OF A COATING TO AN INCH OR TWO. H850 TEMPS WILL BE RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL ACCORDING TO THE LATEST GEFS. TEMPS WILL STILL RUN ABOUT 10 DEGREES OR SO BELOW NORMAL. OUR FORECAST FAVORS THE COLD NAM MOS MAX TEMPS WITH TEENS OVER THE SRN DACKS. LOWER TO M20S OVER THE REST OF THE FCST AREA...EXCEPT U20S OVER THE MID HUDSON VALLEY...SRN TACONICS...AND NW CT. TUE NIGHT...A CLIPPER LOW APPROACHES FROM THE NRN GREAT LAKES REGION...AND SE ONTARIO. THIS CLIPPER WILL TAP SOME LAKE EFFECT MOISTURE...AS THE FLOW BACKS TO SOUTHWEST. THERE IS SOME SYNOPTIC LIFT WITH THIS SYSTEM. OROGRAPHIC AND LOW-LEVEL CONVERGENCE MAY PROMOTE A PERIOD OF LIGHT SNOW ESPECIALLY NORTH AND WEST OF THE CAPITAL REGION. A BURST OF LAKE EFFECT OR LAKE ENHANCED SNOWFALL MAY OCCUR OVER THE WRN DACKS/WRN MOHAWK VALLEY AROUND MIDNIGHT AND THEREAFTER. 1-4 INCHES OF SNOWFALL MAY BE POSSIBLE...ESPECIALLY OVER THE WRN DACKS BY WED MORNING. WITH THE WEAK THERMAL ADVECTION...SLIGHT OR LOW CHANCES OF SNOW SHOWERS SPREAD EASTWARD ACROSS THE FCST AREA AFTER MIDNIGHT. LOWS WILL RANGE FROM THE SINGLE DIGITS OVER THE NW PORTION OF THE FCST AREA TO TEENS FROM THE MOHAWK VALLEY/CAPITAL REGION SOUTH AND EAST. WED-WED NIGHT...THE CLIPPER MOVES N/NE OF NRN NY OVER SRN QUEBEC BY NOON. ANOTHER LOW PRESSURE SYSTEM FORMS WELL OFF THE MID ATLANTIC COAST. A PERIOD OF SNOW SHOWERS OR LIGHT SNOW WILL IMPACT THE REGION DURING THE MORNING INTO THE EARLY PM AHEAD OF THE ARCTIC FRONT. CHC POPS WERE USED FOR THE ENTIRE AREA. SNOW ACCUMS OF A COATING TO AN INCH WILL BE POSSIBLE. ARCTIC AIR POURS BACK INTO THE REGION WITH H850 TEMPS FALLING TO -19C TO -23C OVER THE FCST AREA...AND THE GEFS INDICATE THESE VALUES WILL BE 2 TO 3 STANDARD DEVIATIONS BELOW NORMAL. THE STRONG COLD ADVECTION SWEEPS THROUGH BEFORE NIGHTFALL. AFTER HIGHS IN THE TEENS AND 20S WITH BLUSTERY CONDITIONS...LOWS WILL BE ZERO TO 5 BELOW OVER THE SRN DACKS AND PARTS OF THE LAKE GEORGE REGION....AND SINGLE DIGITS ELSEWHERE. UPSLOPE AND LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN THE AFTERNOON...AND THEN TAPER SNOW SHOWERS NORTH AND WEST OF THE TRI CITIES WITH ANOTHER DISTURBANCE APPROACHING FROM THE UPPER GREAT LAKES REGION. WIND CHILLS VALUES MAY NOT HIT ADVISORY LEVELS WED NIGHT DUE TO A WEAKENING WIND FIELD...BUT MAY HIT ADVISORY LEVELS OVER SOME OF THE MTN ZONES THU NIGHT/FRI MORNING. && .LONG TERM /THURSDAY THROUGH MONDAY/... A SERIES OF EMBEDDED SHORTWAVES WILL MOVE ABOUT THE BASE OF A LARGE UPPER LEVEL TROUGH THAT WILL PROVIDE CHANCES OF SOME PRECIPITATION THROUGHOUT THE EXTENDED PERIOD. THE UPPER LEVEL FLOW PATTERN WILL BEGIN TO SLOWLY TRANSITION INTO A ZONAL PATTERN WITH COLD AIR STILL IN PLACE AS WE GO THE THE END OF THE EXTENDED PERIOD. THURSDAY INTO FRIDAY...COLD NORTHWESTERLY FLOW WITH BELOW AVERAGE TEMPERATURES WITH T850 BETWEEN -20C TO -24C AND T925 TEMPS BETWEEN -16C AND -20C WILL BE LOCKED INTO THE REGION. A NEGATIVE TILTED SHORTWAVE TROUGH WITHIN THE UPPER LEVEL FLOW WITH THE AXIS OVER THE NY/CANADA BORDER WILL PROVIDE THE CHANCE OF SNOW SHOWERS ESPECIALLY AREAS NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION NEAR THE UPPER LEVEL TROUGH AS WE GO THURSDAY NIGHT INTO FRIDAY MORNING. A STEEP GRADIENT IN ISOBARS WILL ALSO PRODUCE GUSTY NORTHWEST WINDS WITH GUSTS NEAR 30 MPH POSSIBLE ESPECIALLY IN THE HIGHEST TERRAIN. TEMPERATURES ON THURSDAY WILL RANGE FROM THE LOWER 20S TO UPPER 20S WHICH WILL FALL TO LOWER TEENS IN THE HIGH TERRAIN TO NEAR 20 IN VALLEY LOCATIONS ON FRIDAY. LOW TEMPERATURES ON THURSDAY WILL BE VERY COLD WITH VALUES RANGING FROM 10 BELOW TO NEAR ZERO IN THE HIGH TERRAIN TO AROUND ZERO TO 5 ABOVE FOR THE VALLEY AREAS. FRIDAY NIGHT THROUGH MONDAY...COLD AIR FROM CANADA WITH NORTHWESTERLY WINDS WILL CONTINUE WITH SERIES OF UPPER LEVEL TROUGHS CONTINUING TO MOVE WEST TO EAST ACROSS OUR AREA WITH AREAS OF WEAK HIGH PRESSURE IN BETWEEN THE PASSING DISTURBANCES AS THE UPPER LEVEL WAVE OSCILLATES AROUND THE LARGE UPPER LEVEL LOW IN NORTHERN QUEBEC. THE NEXT CHANCE OF SNOW SHOWERS ACCORDING TO THE LATEST 12Z MODELS AND NUMERICAL GUIDANCE WILL BE DURING THE DAY ON SATURDAY AS ANOTHER WAVE OF LOW PRESSURE MOVES RIGHT OVER OUR REGION ACCORDING TO THE LATEST TRENDS. CHANCE OF SNOW SHOWERS WILL BE IN THE FORECAST AT THIS TIME AS THE TRACK AND INTENSITY AGREEMENT BETWEEN THE MODELS SHOW LOW CONFIDENCE AT THIS TIME. A SURFACE HIGH PRESSURE WILL WORK INTO THE AREA ON SUNDAY GIVING TRANQUIL WEATHER CONDITIONS. AS WE GO INTO MONDAY...THE MODELS DO DIFFER IN OUR NEXT WEATHER SYSTEM WITH ITS TRACK AND INTENSITY. THIS WILL HAVE TO BE MONITORED WITH FUTURE UPDATES TO THE FORECAST. HIGH TEMPERATURES FROM SATURDAY INTO MONDAY WILL REMAIN BELOW AVERAGE WITH TEMPERATURES RANGING FROM THE MID TEENS TO MID 20S. LOW TEMPERATURES WILL ALSO BE VERY COLD FOR THIS TIME OF YEAR WITH TEMPERATURE 10 BELOW ZERO TO NEAR ZERO FOR THE LAKE GEORGE SARATOGA REGION POINTS NORTH AND WEST AND ALSO IN THE HIGH TERRAIN OF NEW ENGLAND AND WITH LOW TEMPERATURES OF 0 TO 5 IN THE IMMEDIATE CAPITAL REGION AND VALLEY LOCATIONS. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... SOME LAKE EFFECT/ENHANCED SNOW SHOWERS/FLURRIES MAY REACH KGFL/KALB/KPSF AT TIMES THIS AFTERNOON. MAINLY VFR CONDITIONS ARE EXPECTED...BUT ANY SNOW SHOWER ACTIVITY COULD PRODUCE BRIEF PERIODS OF MVFR/IFR...ESP FOR VSBYS. THE SNOW SHOWER THREAT SHOULD END AT KGFL THIS EVENING. THE SCATTERED SNOW SHOWER THREAT SHOULD CONTINUE AT KALB AND KPSF THROUGH TONIGHT DUE TO THE WIND DIRECTION NEARLY PARALLELING THE MOHAWK VALLEY AND INTO THE BERKSHIRES...OSCILLATING NORTH AND SOUTH WITH SUBTLE WIND SHIFTS. STILL...VFR CONDITIONS SHOULD DOMINATE ALL TAF SITES THROUGH TOMORROW MORNING OUTSIDE OF ANY BRIEF SNOW SHOWERS. WEST TO NORTHWEST WINDS AT 13-18 KT WITH GUSTS OF 20-30 KT ARE EXPECTED THIS AFTERNOON. THE STRONGEST GUSTS ARE EXPECTED FROM KALB-KPSF IN THE FAVORED W-NW FLOW. THESE BRISK WINDS WILL PERSIST THROUGH EARLY MONDAY EVENING...BEFORE GRADUALLY DIMINISHING AFTER 05Z-08Z/TUE TO 5-10 KT. WEST WINDS SHOULD CONTINUE TOMORROW MORNING AT AROUND 10 KT. OUTLOOK... TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. WEDNESDAY: MODERATE OPERATIONAL IMPACT.WINDY WITH A CHANCE OF SHSN. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: MODERATE OPERATIONAL IMPACT.BREEZY CHANCE OF SHSN. THURSDAY NIGHT: LOW OPERATIONAL IMPACT.BREEZY NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. && .HYDROLOGY... AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW. NO HYDRO IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST TUESDAY FOR NYZ038. MA...NONE. VT...NONE. && $$ SYNOPSIS...11/WASULA NEAR TERM...WASULA SHORT TERM...WASULA LONG TERM...LFM AVIATION...NAS HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1242 PM EST MON FEB 24 2014 .SYNOPSIS... A STRONG COLD FRONT WAS EXITING THE REGION EARLY THIS MORNING... BRINGING PROGRESSIVELY COLDER CONDITIONS THROUGH NEXT WEEKEND. MAINLY DRY CONDITIONS WILL BE IN PLACE AS LARGE HIGH PRESSURE MOVES ACROSS. ONE EXCEPTION WILL BE FOR THE RISK OF ACCUMULATING SNOWFALL FOR WEDNESDAY AS LOW PRESSURE DEVELOPS WELL SOUTH OF NEW ENGLAND. ANOTHER LOW MAY BRING SOME SNOWFALL NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1240 PM UPDATE... DECENT COVERAGE OF STRATO CU ACROSS SNE EXCEPT FOR FAR SE MA AND CAPE/ISLANDS. LOW AND MID LEVEL MOISTURE COMBINED WITH STEEP LOW LEVEL LAPSE RATES RESPONSIBLE FOR THE CLOUDS. HIRES MODELS CONTINUE TO SHOW POTENTIAL FOR A FEW SNOW SHOWERS ACROSS NORTHERN ZONES THIS AFTERNOON ALTHOUGH LOW DEWPOINTS WILL LIMIT AREAL COVERAGE. NEAR STEADY TEMPS WITH GUSTY WINDS. PREVIOUS DISCUSSION... POST FRONTAL STRATO-CU FILLING BACK IN ACROSS THE INTERIOR AS LOW AND MID LEVEL MOISTURE FROM THE N SPILLS INTO THE REGION AND EXPECT SCT-BKN CU TO DEVELOP IN THE COASTAL PLAIN. STEEP LOW LEVEL LAPSE RATES AND LOW LEVEL MOISTURE SUPPORT A FEW FLURRIES OR SNOW SHOWERS...ESPECIALLY N OF THE PIKE WHERE HRRR IS TARGETING. STRONG COLD AIR ADVECTION WILL RESULT IN TEMPS REMAINING NEARLY STEADY OR PERHAPS FALLING A FEW DEGREES ALONG WITH GUSTY W/NW WINDS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... TONIGHT... NOT TOO MUCH CHANGE FROM THE DAY AS CYCLONIC CURVATURE...DECENT SFC PRES GRADIENT AND TRAPPED MID LVL MOISTURE REMAIN IN PLAY ACROSS THE AREA. THEREFORE..EXPECT AT LEAST SOME CLOUDS AND WINDS TO REMAIN THROUGH THE OVERNIGHT HOURS. WHILE THIS WILL LIMIT THE ABILITY TO RADIATE...NORMAL DIURNAL TRENDS SHOULD STILL ALLOW MINS INTO THE LOW TEENS AND 20S. WITH WINDS OF AROUND 10 MPH STILL POSSIBLE...THIS WOULD YIELD SOME WIND CHILLS BELOW ZERO FOR PORTIONS OF THE INTERIOR AND IN THE SINGLE DIGITS CLOSER TO THE SHORELINES. TUESDAY... A COLD AND BRISK START IS EXPECTED AS WINDS CONTINUE TO GUST UP TO ABOUT 20 MPH AFTER SUNRISE AND MIXING SETS UP. ANOTHER ROUND OF PARTLY CLOUDY CONDITIONS AND HIGHER SUN ANGLES SHOULD ALLOW HIGHS TO INCREASE INTO THE MID 20S TO LOW 30S DESPITE THIS COOLER START BUT WITH WIND CHILL VALUES IN THE TEENS TO LOW 20S. MAINLY DRIER WX AS NOSE OF HIGH PRES BEGINS TO BUILD OVER FROM THE SW...LIMITING THE POTENTIAL FOR MORE FLURRY ACTIVITY IN COMPARISON TO MON. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * JANUARY-LIKE TEMPERATURES THIS WEEK AND AS WE ENTER MARCH NEXT WEEKEND * RISK FOR ACCUMULATING SNOW WED AND AGAIN NEXT WEEKEND * OTHERWISE MAINLY DRY CONDITIONS PREVAIL SYNOPTIC OVERVIEW... NOT MUCH CHANGE IN THE FORECAST FROM PREVIOUS DAYS. HIGH AMPLITUDE NORTHERN STREAM PATTERN DEVELOPS WITH POLAR VORTEX BEING DISPLACED SOUTHWARD INTO ONTARIO BY THU. THIS RESULTS IN A STEADY STREAM OF ARCTIC AIR INTO SOUTHERN NEW ENGLAND THIS WEEK AND INTO NEXT WEEKEND. THAT/S THE EASY PART OF THE FORECAST. WHAT BECOMES DIFFICULT TO NAIL DOWN AT THIS TIME RANGE IS THE INTENSITY AND TRACK OF ANY EAST CYCLOGENESIS...AS ARCTIC SHORT WAVES PIVOT AROUND THE SOUTHERN BASE OF THE POLAR VORTEX. FURTHER COMPLICATING THE FORECAST IS IF PACIFIC ENERGY UNDERCUTTING THE WESTERN RIDGE INTERACTS /PHASING VS UNPHASED/ WITH ARCTIC SHORT WAVE TROUGHS ALONG THE EAST COAST. MODEL PREFERENCES AND SENSIBLE WEATHER... WEDNESDAY...00Z DETERMINISTIC GFS AND ECMWF IN AGREEMENT ON AN UNPHASED SOLUTION WITH NORTHERN STREAM LOW MOVING ACROSS SOUTHEAST CANADA AND EAST COAST CYCLOGENESIS TRACKING WELL SOUTHEAST OF 40N/70W BENCHMARK. HOWEVER APPEARS THERE WILL BE ENOUGH MID LEVEL LIFT TO INDUCE AN INVERTED SURFACE TROUGH BETWEEN THESE TWO LOWS TO GENERATE A FEW TENTHS OF QPF OVER SOUTHERN NEW ENGLAND. THUS A LOW TO MODERATE RISK OF A FEW FLUFFY INCHES OF SNOW...WITH HIGHEST RISK OVER SOUTHEAST MA. HOWEVER CAN/T COMPLETELY RULE OUT A STRONGER/PHASED SOLUTION AS ARCTIC SHORT WAVE/PV ANOMALY THAT INDUCES EAST COAST CYCLOGENESIS IS CURRENTLY MOVING ACROSS NORTHWEST CANADA EARLY THIS MORNING. MODELS LIKELY NOT SAMPLING THIS PACKET OF JET ENERGY VERY WELL GIVEN THIS IS A DATA SPARSE AREA. THUS WILL HAVE TO WAIT UNTIL THIS FEATURE ENTERS SOUTHERN CANADA BEFORE MODELS BEGIN BETTER SAMPLING OF THIS JET ENERGY. IF THIS SHORT WAVE TROUGH IS MORE AMPLIFIED THAN MODELS CURRENTLY SIMULATE...A TRACK CLOSER TO THE COAST IS PLAUSIBLE. THEREFORE ITS STILL TOO EARLY TO LOCK INTO A SINGLE SCENARIO. HOWEVER FOR THE MOMENT WILL PLAY THE MOST LIKELY SCENARIO...A LOW TO MODERATE RISK OF A FEW INCHES OF FLUFFY SNOW. THURSDAY THRU SUNDAY...ANOTHER ARCTIC FRONT MOVES ACROSS THE AREA THU OR FRI WITH GEFS AND ECENS ENSEMBLE POST FRONTAL 850 MEAN TEMPS VARYING FROM -15C TO -20C ACROSS SOUTHERN NEW ENGLAND. THUS COLDER THAN NORMAL TEMPS HOWEVER ANY RECORD BREAKING COLD SHOULD REMAIN WEST OF NEW ENGLAND ACROSS THE GREAT LAKES GIVEN PROXIMITY OF COLD AIR CORE. WILL ALSO HAVE TO WATCH FOR POTENTIAL SNOW SQUALLS ALONG AND AHEAD OF FRONTAL BOUNDARY...AS INCREASING SUN ANGLE /SAT MAR 1ST/ AND COLD AIR ALOFT WILL YIELD STEEP LOW LEVEL LAPSE RATES. THEN NEXT WEEKEND THE FOCUS WILL BE ON PACIFIC ENERGY MARCHING ACROSS THE SOUTHERN STATES AND ITS POSSIBLE INTERACTION/PHASING WITH THE NORTHERN STREAM OVER THE NORTHEAST. THE 00Z GEFS AND ECENS ENSEMBLE MEAN ARE WELL OFFSHORE WITH ANY CYCLOGENESIS...AS WELL AS THE 00Z GFS. THE 00Z ECMWF IS MUCH CLOSER TO THE COAST BUT ALSO WEAKER. GIVEN THE UNCERTAINTY WILL CONTINUE WITH CHANCE POPS FOR NEXT WEEKEND. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/... HIGH CONFIDENCE. MAINLY VFR THROUGH THE PERIOD WITH OCCASIONAL CIGS 040-080. A FEW LIGHT SNOW SHOWERS POSSIBLE THIS AFTERNOON NORTH OF THE PIKE AND AGAIN TUE AFTERNOON. W/NW WIND GUSTS TO 25 KT THIS AFTERNOON DIMINISHING TONIGHT...THEN 20-25 KT TUE. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... VFR ALONG WITH GUSTY WNW WINDS. THE EXCEPTION WILL BE WED WHEN WINDS WILL BRIEFLY RELAX. HOWEVER A PERIOD OF SNOW IS POSSIBLE WED WITH MVFR CONDITIONS. HIGHEST PROBABILITY OF SNOW AND MVFR CONDITIONS IS ACROSS SOUTHEAST MA WED. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. THROUGH TUESDAY...HIGH CONFIDENCE. W-NW WINDS WILL BE INCREASING THROUGH THE DAY TODAY WITH GUSTS WIDESPREAD 25-30 KT EXPECTED. A FEW GUSTS MAY APPROACH GALE FORCE...BUT THE MAJORITY SHOULD REMAIN BELOW. THESE WINDS WILL MAINTAIN THROUGH THE OVERNIGHT HOURS TONIGHT...ONLY DIMINISHING INTO THE MORNING HOURS FOR TUE THEN DROPPING BELOW SMALL CRAFT THRESHOLDS BY THE LATE DAY TUE. WITH INCREASING WINDS EXPECT SEAS TO BUILD AS WELL...REACHING 5-7FT AT TIMES MAINLY ON THE OCEAN WATERS. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... GUSTY WNW WINDS AND PERIODS OF FREEZING SPRAY ARE EXPECTED AS ARCTIC AIR OVERSPREADS THE REGION. WINDS BRIEFLY RELAX WED AS ONE AREA OF LOW PRES TRACKS ACROSS SOUTHEAST CANADA AND A POTENTIAL GALE CENTER PASSES SOUTHEAST OF 40N/70W BENCHMARK. A PERIOD OF SNOW WITH REDUCED VSBY IS LIKELY WED ESPECIALLY OVER THE WATERS SOUTHEAST OF NANTUCKET. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST TUESDAY FOR ANZ230>237-251. SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR ANZ250-254>256. && $$ SYNOPSIS...NOCERA/DOODY NEAR TERM...KJC SHORT TERM...DOODY LONG TERM...NOCERA AVIATION...KJC/NOCERA MARINE...NOCERA/DOODY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1018 AM EST MON FEB 24 2014 .SYNOPSIS... A STRONG COLD FRONT WAS EXITING THE REGION EARLY THIS MORNING... BRINGING PROGRESSIVELY COLDER CONDITIONS THROUGH NEXT WEEKEND. MAINLY DRY CONDITIONS WILL BE IN PLACE AS LARGE HIGH PRESSURE MOVES ACROSS. ONE EXCEPTION WILL BE FOR THE RISK OF ACCUMULATING SNOWFALL FOR WEDNESDAY AS LOW PRESSURE DEVELOPS WELL SOUTH OF NEW ENGLAND. ANOTHER LOW MAY BRING SOME SNOWFALL NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1015 AM UPDATE... POST FRONTAL STRATO-CU FILLING BACK IN ACROSS THE INTERIOR AS LOW AND MID LEVEL MOISTURE FROM THE N SPILLS INTO THE REGION AND EXPECT SCT-BKN CU TO DEVELOP IN THE COASTAL PLAIN. STEEP LOW LEVEL LAPSE RATES AND LOW LEVEL MOISTURE SUPPORT A FEW FLURRIES OR SNOW SHOWERS...ESPECIALLY N OF THE PIKE WHERE HRRR IS TARGETING. STRONG COLD AIR ADVECTION WILL RESULT IN TEMPS REMAINING NEARLY STEADY OR PERHAPS FALLING A FEW DEGREES ALONG WITH GUSTY W/NW WINDS. PREVIOUS DISCUSSION... OTHERWISE TODAY...AFTER THE FRONT/PRECIP BAND SHIFTS OFFSHORE...STRONG COLD ADVECTION WILL DEFINE THE WX. H85 TEMPERATURES WILL BE DECLINING FROM AN AVERAGE OF ABOUT -5C TO ABOUT -16C BY THE OVERNIGHT HOURS TONIGHT. DRY AIR WILL ALSO BE RAPIDLY MOVING IN WITH TIME AS WELL. THEREFORE...EXPECT HIGH TEMPS TO OCCUR BY LATE THIS MORNING WITH COOLING EXPECTED THROUGH THE AFTERNOON HOURS...WITH RANGES FROM THE LOW TO UPPER 30S. THE COMBINATION OF STRONG CYCLONIC CURVATURE ALOFT WITH A SHORTWAVE MOVING ACROSS THE AREA...STEEP SFC-H9 LAPSE RATES ON THE ORDER OF 8C/KM AND A BIT OF TRAPPED MID LVL MOISTURE BENEATH A BUILDING SUBSIDENCE INVERSION WILL LIKELY YIELD WIDESPREAD CU-STRATOCU ACROSS THE AREA DURING PEAK HEATING. THE DEEP NEAR SFC UNSTABLE LAYER MAY ALSO BE ENOUGH TO INDUCE SOME LOCALIZED FLURRY ACTIVITY ESPECIALLY IN THE W WHERE CAA WILL BE MAXIMIZED. HAVE ADDED SOME SLIGHT CHANCE POPS TO THE FORECAST ALONG WITH THE INCREASING CLOUDS. OCEAN EFFECT CLOUDS ARE ALSO POSSIBLE ACROSS PORTIONS OF CAPE COD GIVEN THE WIND TRAJECTORY AND OCEAN BL INSTABILITY. ALSO...WITH THIS DEEP LAYER MIXING...MUCH OF THE MOMENTUM IN A NEARLY 40 KT LLJ SHOULD BE TAPPED. THEREFORE...EXPECT BRISK NW WINDS GUSTING 30-35 MPH AT TIMES THROUGH THE DAY. THIS WILL MAKE FOR WIND CHILL VALUES IN THE 20S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... TONIGHT... NOT TOO MUCH CHANGE FROM THE DAY AS CYCLONIC CURVATURE...DECENT SFC PRES GRADIENT AND TRAPPED MID LVL MOISTURE REMAIN IN PLAY ACROSS THE AREA. THEREFORE..EXPECT AT LEAST SOME CLOUDS AND WINDS TO REMAIN THROUGH THE OVERNIGHT HOURS. WHILE THIS WILL LIMIT THE ABILITY TO RADIATE...NORMAL DIURNAL TRENDS SHOULD STILL ALLOW MINS INTO THE LOW TEENS AND 20S. WITH WINDS OF AROUND 10 MPH STILL POSSIBLE...THIS WOULD YIELD SOME WIND CHILLS BELOW ZERO FOR PORTIONS OF THE INTERIOR AND IN THE SINGLE DIGITS CLOSER TO THE SHORELINES. TUESDAY... A COLD AND BRISK START IS EXPECTED AS WINDS CONTINUE TO GUST UP TO ABOUT 20 MPH AFTER SUNRISE AND MIXING SETS UP. ANOTHER ROUND OF PARTLY CLOUDY CONDITIONS AND HIGHER SUN ANGLES SHOULD ALLOW HIGHS TO INCREASE INTO THE MID 20S TO LOW 30S DESPITE THIS COOLER START BUT WITH WIND CHILL VALUES IN THE TEENS TO LOW 20S. MAINLY DRIER WX AS NOSE OF HIGH PRES BEGINS TO BUILD OVER FROM THE SW...LIMITING THE POTENTIAL FOR MORE FLURRY ACTIVITY IN COMPARISON TO MON. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * JANUARY-LIKE TEMPERATURES THIS WEEK AND AS WE ENTER MARCH NEXT WEEKEND * RISK FOR ACCUMULATING SNOW WED AND AGAIN NEXT WEEKEND * OTHERWISE MAINLY DRY CONDITIONS PREVAIL SYNOPTIC OVERVIEW... NOT MUCH CHANGE IN THE FORECAST FROM PREVIOUS DAYS. HIGH AMPLITUDE NORTHERN STREAM PATTERN DEVELOPS WITH POLAR VORTEX BEING DISPLACED SOUTHWARD INTO ONTARIO BY THU. THIS RESULTS IN A STEADY STREAM OF ARCTIC AIR INTO SOUTHERN NEW ENGLAND THIS WEEK AND INTO NEXT WEEKEND. THAT/S THE EASY PART OF THE FORECAST. WHAT BECOMES DIFFICULT TO NAIL DOWN AT THIS TIME RANGE IS THE INTENSITY AND TRACK OF ANY EAST CYCLOGENESIS...AS ARCTIC SHORT WAVES PIVOT AROUND THE SOUTHERN BASE OF THE POLAR VORTEX. FURTHER COMPLICATING THE FORECAST IS IF PACIFIC ENERGY UNDERCUTTING THE WESTERN RIDGE INTERACTS /PHASING VS UNPHASED/ WITH ARCTIC SHORT WAVE TROUGHS ALONG THE EAST COAST. MODEL PREFERENCES AND SENSIBLE WEATHER... WEDNESDAY...00Z DETERMINISTIC GFS AND ECMWF IN AGREEMENT ON AN UNPHASED SOLUTION WITH NORTHERN STREAM LOW MOVING ACROSS SOUTHEAST CANADA AND EAST COAST CYCLOGENESIS TRACKING WELL SOUTHEAST OF 40N/70W BENCHMARK. HOWEVER APPEARS THERE WILL BE ENOUGH MID LEVEL LIFT TO INDUCE AN INVERTED SURFACE TROUGH BETWEEN THESE TWO LOWS TO GENERATE A FEW TENTHS OF QPF OVER SOUTHERN NEW ENGLAND. THUS A LOW TO MODERATE RISK OF A FEW FLUFFY INCHES OF SNOW...WITH HIGHEST RISK OVER SOUTHEAST MA. HOWEVER CAN/T COMPLETELY RULE OUT A STRONGER/PHASED SOLUTION AS ARCTIC SHORT WAVE/PV ANOMALY THAT INDUCES EAST COAST CYCLOGENESIS IS CURRENTLY MOVING ACROSS NORTHWEST CANADA EARLY THIS MORNING. MODELS LIKELY NOT SAMPLING THIS PACKET OF JET ENERGY VERY WELL GIVEN THIS IS A DATA SPARSE AREA. THUS WILL HAVE TO WAIT UNTIL THIS FEATURE ENTERS SOUTHERN CANADA BEFORE MODELS BEGIN BETTER SAMPLING OF THIS JET ENERGY. IF THIS SHORT WAVE TROUGH IS MORE AMPLIFIED THAN MODELS CURRENTLY SIMULATE...A TRACK CLOSER TO THE COAST IS PLAUSIBLE. THEREFORE ITS STILL TOO EARLY TO LOCK INTO A SINGLE SCENARIO. HOWEVER FOR THE MOMENT WILL PLAY THE MOST LIKELY SCENARIO...A LOW TO MODERATE RISK OF A FEW INCHES OF FLUFFY SNOW. THURSDAY THRU SUNDAY...ANOTHER ARCTIC FRONT MOVES ACROSS THE AREA THU OR FRI WITH GEFS AND ECENS ENSEMBLE POST FRONTAL 850 MEAN TEMPS VARYING FROM -15C TO -20C ACROSS SOUTHERN NEW ENGLAND. THUS COLDER THAN NORMAL TEMPS HOWEVER ANY RECORD BREAKING COLD SHOULD REMAIN WEST OF NEW ENGLAND ACROSS THE GREAT LAKES GIVEN PROXIMITY OF COLD AIR CORE. WILL ALSO HAVE TO WATCH FOR POTENTIAL SNOW SQUALLS ALONG AND AHEAD OF FRONTAL BOUNDARY...AS INCREASING SUN ANGLE /SAT MAR 1ST/ AND COLD AIR ALOFT WILL YIELD STEEP LOW LEVEL LAPSE RATES. THEN NEXT WEEKEND THE FOCUS WILL BE ON PACIFIC ENERGY MARCHING ACROSS THE SOUTHERN STATES AND ITS POSSIBLE INTERACTION/PHASING WITH THE NORTHERN STREAM OVER THE NORTHEAST. THE 00Z GEFS AND ECENS ENSEMBLE MEAN ARE WELL OFFSHORE WITH ANY CYCLOGENESIS...AS WELL AS THE 00Z GFS. THE 00Z ECMWF IS MUCH CLOSER TO THE COAST BUT ALSO WEAKER. GIVEN THE UNCERTAINTY WILL CONTINUE WITH CHANCE POPS FOR NEXT WEEKEND. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/... 7 AM UPDATE... NO MAJOR CHANGES FROM PREVIOUS 06Z TAFS. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ TODAY AND TUESDAY...HIGH CONFIDENCE. MAINLY VFR THROUGH THE PERIOD...BUT SOME LOW CU BETWEEN 030-060 POSSIBLE THROUGH DAYLIGHT HOURS ALONG WITH SOME LIGHT SNOW SHOWERS POSSIBLE MAINLY W OF A IJD-ORH-EEN LINE TODAY. NW WINDS GUSTING 25-30 KT AT TIMES TODAY...W WINDS GUST 20-25 KT ON TUE. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... VFR ALONG WITH GUSTY WNW WINDS. THE EXCEPTION WILL BE WED WHEN WINDS WILL BRIEFLY RELAX. HOWEVER A PERIOD OF SNOW IS POSSIBLE WED WITH MVFR CONDITIONS. HIGHEST PROBABILITY OF SNOW AND MVFR CONDITIONS IS ACROSS SOUTHEAST MA WED. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. THROUGH TUESDAY...HIGH CONFIDENCE. W-NW WINDS WILL BE INCREASING THROUGH THE DAY TODAY WITH GUSTS WIDESPREAD 25-30 KT EXPECTED. A FEW GUSTS MAY APPROACH GALE FORCE...BUT THE MAJORITY SHOULD REMAIN BELOW. THESE WINDS WILL MAINTAIN THROUGH THE OVERNIGHT HOURS TONIGHT...ONLY DIMINISHING INTO THE MORNING HOURS FOR TUE THEN DROPPING BELOW SMALL CRAFT THRESHOLDS BY THE LATE DAY TUE. WITH INCREASING WINDS EXPECT SEAS TO BUILD AS WELL...REACHING 5-7FT AT TIMES MAINLY ON THE OCEAN WATERS. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... GUSTY WNW WINDS AND PERIODS OF FREEZING SPRAY ARE EXPECTED AS ARCTIC AIR OVERSPREADS THE REGION. WINDS BRIEFLY RELAX WED AS ONE AREA OF LOW PRES TRACKS ACROSS SOUTHEAST CANADA AND A POTENTIAL GALE CENTER PASSES SOUTHEAST OF 40N/70W BENCHMARK. A PERIOD OF SNOW WITH REDUCED VSBY IS LIKELY WED ESPECIALLY OVER THE WATERS SOUTHEAST OF NANTUCKET. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST TUESDAY FOR ANZ230>237-251. SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR ANZ250-254>256. && $$ SYNOPSIS...NOCERA/DOODY NEAR TERM...KJC/DOODY SHORT TERM...DOODY LONG TERM...NOCERA AVIATION...NOCERA/DOODY MARINE...NOCERA/DOODY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
713 AM EST MON FEB 24 2014 .SYNOPSIS... A STRONG COLD FRONT WAS EXITING THE REGION EARLY THIS MORNING... BRINGING PROGRESSIVELY COLDER CONDITIONS THROUGH NEXT WEEKEND. MAINLY DRY CONDITIONS WILL BE IN PLACE AS LARGE HIGH PRESSURE MOVES ACROSS. ONE EXCEPTION WILL BE FOR THE RISK OF ACCUMULATING SNOWFALL FOR WEDNESDAY AS LOW PRESSURE DEVELOPS WELL SOUTH OF NEW ENGLAND. ANOTHER LOW MAY BRING SOME SNOWFALL NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 7 AM UPDATE... COLD FRONT NOW OVER NANTUCKET WILL MOVE OFFSHORE SHORTLY. STRONG COLD AIR ADVECTION BEHIND THE FRONT WITH SURFACE DEW PTS ALREADY FALLING INTO THE SINGLE DIGITS ACROSS NORTHEAST MA. CLOUD SHIELD OVER SOUTHEAST MA ASSOCIATED WITH THE FRONT WILL MOVE OFFSHORE LATER THIS MORNING. HOWEVER POST FRONTAL CLOUDS WILL FILL BACK IN AS COLD AIR ALOFT COMBINES WITH DIURNAL HEATING TO YIELD STEEP LOW LEVEL LAPSE RATES. THIS COUPLED WITH CYCLONIC FLOW ALOFT MAY YIELD SCT SNOW SHOWERS THIS AFTERNOON...ESPECIALLY OVER THE HIGHER TERRAIN WHERE UPSLOPE FLOW WILL PROVIDE ADDITIONAL LIFT. HOWEVER DRY LOW LEVELS MAY ONLY YIELD SOME FLURRIES OR VIRGA. PREVIOUS FORECAST CAPTURES THESE DETAILS NICELY...THUS NO MAJOR CHANGES WITH THIS FORECAST UPDATE. EARLIER DISCUSSION BELOW. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A COMBINATION OF BOTH OBS AND MSAS SUGGEST SFC COLD FRONT HAS MOVED OFFSHORE OF ALL SRN NEW ENGLAND COASTLINES SAVE FOR THE CAPE/ISLANDS AS OF 0830Z. NOW IN CLOSE ASSOCIATION WITH THIS FRONT IS A BAND OF WSR-88D ECHOS OF 25-30 DBZ WHICH ALSO CONTINUE TO GRADUALLY SLIDE OFF THE S COAST AND SHOULD BE OFFSHORE OF EVERYWHERE BY 10-12Z BASED ON CURRENT SPEED AND TIMING. DESPITE THE ECHOS...PRECIP HAS REALLY STRUGGLED TO REACH THE SFC THANKS TO 10-15F DWPT DEPRESSIONS ACROSS THE REGION. EVEN THEN...WITH SFC TEMPS ABOVE FREEZING AND A LACK OF HEAVY PRECIP TO FORCE THE NEAR SFC LAYER TO WET-BULB...ANY PRECIP THAT HAS REACHED THE SFC HAS BEEN IN THE FORM OF LIGHT RAIN. BASED EARLY MORNING POPS ON THE LATEST RAP WHICH CONTINUES TO FOLLOW THIS BAND WELL BUT CAPPED ANY POPS AT CHANCE. OTHERWISE TODAY...AFTER THE FRONT/PRECIP BAND SHIFTS OFFSHORE...STRONG COLD ADVECTION WILL DEFINE THE WX. H85 TEMPERATURES WILL BE DECLINING FROM AN AVERAGE OF ABOUT -5C TO ABOUT -16C BY THE OVERNIGHT HOURS TONIGHT. DRY AIR WILL ALSO BE RAPIDLY MOVING IN WITH TIME AS WELL. THEREFORE...EXPECT HIGH TEMPS TO OCCUR BY LATE THIS MORNING WITH COOLING EXPECTED THROUGH THE AFTERNOON HOURS...WITH RANGES FROM THE LOW TO UPPER 30S. THE COMBINATION OF STRONG CYCLONIC CURVATURE ALOFT WITH A SHORTWAVE MOVING ACROSS THE AREA...STEEP SFC-H9 LAPSE RATES ON THE ORDER OF 8C/KM AND A BIT OF TRAPPED MID LVL MOISTURE BENEATH A BUILDING SUBSIDENCE INVERSION WILL LIKELY YIELD WIDESPREAD CU-STRATOCU ACROSS THE AREA DURING PEAK HEATING. THE DEEP NEAR SFC UNSTABLE LAYER MAY ALSO BE ENOUGH TO INDUCE SOME LOCALIZED FLURRY ACTIVITY ESPECIALLY IN THE W WHERE CAA WILL BE MAXIMIZED. HAVE ADDED SOME SLIGHT CHANCE POPS TO THE FORECAST ALONG WITH THE INCREASING CLOUDS. OCEAN EFFECT CLOUDS ARE ALSO POSSIBLE ACROSS PORTIONS OF CAPE COD GIVEN THE WIND TRAJECTORY AND OCEAN BL INSTABILITY. ALSO...WITH THIS DEEP LAYER MIXING...MUCH OF THE MOMENTUM IN A NEARLY 40 KT LLJ SHOULD BE TAPPED. THEREFORE...EXPECT BRISK NW WINDS GUSTING 30-35 MPH AT TIMES THROUGH THE DAY. THIS WILL MAKE FOR WIND CHILL VALUES IN THE 20S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... TONIGHT... NOT TOO MUCH CHANGE FROM THE DAY AS CYCLONIC CURVATURE...DECENT SFC PRES GRADIENT AND TRAPPED MID LVL MOISTURE REMAIN IN PLAY ACROSS THE AREA. THEREFORE..EXPECT AT LEAST SOME CLOUDS AND WINDS TO REMAIN THROUGH THE OVERNIGHT HOURS. WHILE THIS WILL LIMIT THE ABILITY TO RADIATE...NORMAL DIURNAL TRENDS SHOULD STILL ALLOW MINS INTO THE LOW TEENS AND 20S. WITH WINDS OF AROUND 10 MPH STILL POSSIBLE...THIS WOULD YIELD SOME WIND CHILLS BELOW ZERO FOR PORTIONS OF THE INTERIOR AND IN THE SINGLE DIGITS CLOSER TO THE SHORELINES. TUESDAY... A COLD AND BRISK START IS EXPECTED AS WINDS CONTINUE TO GUST UP TO ABOUT 20 MPH AFTER SUNRISE AND MIXING SETS UP. ANOTHER ROUND OF PARTLY CLOUDY CONDITIONS AND HIGHER SUN ANGLES SHOULD ALLOW HIGHS TO INCREASE INTO THE MID 20S TO LOW 30S DESPITE THIS COOLER START BUT WITH WIND CHILL VALUES IN THE TEENS TO LOW 20S. MAINLY DRIER WX AS NOSE OF HIGH PRES BEGINS TO BUILD OVER FROM THE SW...LIMITING THE POTENTIAL FOR MORE FLURRY ACTIVITY IN COMPARISON TO MON. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * JANUARY-LIKE TEMPERATURES THIS WEEK AND AS WE ENTER MARCH NEXT WEEKEND * RISK FOR ACCUMULATING SNOW WED AND AGAIN NEXT WEEKEND * OTHERWISE MAINLY DRY CONDITIONS PREVAIL SYNOPTIC OVERVIEW... NOT MUCH CHANGE IN THE FORECAST FROM PREVIOUS DAYS. HIGH AMPLITUDE NORTHERN STREAM PATTERN DEVELOPS WITH POLAR VORTEX BEING DISPLACED SOUTHWARD INTO ONTARIO BY THU. THIS RESULTS IN A STEADY STREAM OF ARCTIC AIR INTO SOUTHERN NEW ENGLAND THIS WEEK AND INTO NEXT WEEKEND. THAT/S THE EASY PART OF THE FORECAST. WHAT BECOMES DIFFICULT TO NAIL DOWN AT THIS TIME RANGE IS THE INTENSITY AND TRACK OF ANY EAST CYCLOGENESIS...AS ARCTIC SHORT WAVES PIVOT AROUND THE SOUTHERN BASE OF THE POLAR VORTEX. FURTHER COMPLICATING THE FORECAST IS IF PACIFIC ENERGY UNDERCUTTING THE WESTERN RIDGE INTERACTS /PHASING VS UNPHASED/ WITH ARCTIC SHORT WAVE TROUGHS ALONG THE EAST COAST. MODEL PREFERENCES AND SENSIBLE WEATHER... WEDNESDAY...00Z DETERMINISTIC GFS AND ECMWF IN AGREEMENT ON AN UNPHASED SOLUTION WITH NORTHERN STREAM LOW MOVING ACROSS SOUTHEAST CANADA AND EAST COAST CYCLOGENESIS TRACKING WELL SOUTHEAST OF 40N/70W BENCHMARK. HOWEVER APPEARS THERE WILL BE ENOUGH MID LEVEL LIFT TO INDUCE AN INVERTED SURFACE TROUGH BETWEEN THESE TWO LOWS TO GENERATE A FEW TENTHS OF QPF OVER SOUTHERN NEW ENGLAND. THUS A LOW TO MODERATE RISK OF A FEW FLUFFY INCHES OF SNOW...WITH HIGHEST RISK OVER SOUTHEAST MA. HOWEVER CAN/T COMPLETELY RULE OUT A STRONGER/PHASED SOLUTION AS ARCTIC SHORT WAVE/PV ANOMALY THAT INDUCES EAST COAST CYCLOGENESIS IS CURRENTLY MOVING ACROSS NORTHWEST CANADA EARLY THIS MORNING. MODELS LIKELY NOT SAMPLING THIS PACKET OF JET ENERGY VERY WELL GIVEN THIS IS A DATA SPARSE AREA. THUS WILL HAVE TO WAIT UNTIL THIS FEATURE ENTERS SOUTHERN CANADA BEFORE MODELS BEGIN BETTER SAMPLING OF THIS JET ENERGY. IF THIS SHORT WAVE TROUGH IS MORE AMPLIFIED THAN MODELS CURRENTLY SIMULATE...A TRACK CLOSER TO THE COAST IS PLAUSIBLE. THEREFORE ITS STILL TOO EARLY TO LOCK INTO A SINGLE SCENARIO. HOWEVER FOR THE MOMENT WILL PLAY THE MOST LIKELY SCENARIO...A LOW TO MODERATE RISK OF A FEW INCHES OF FLUFFY SNOW. THURSDAY THRU SUNDAY...ANOTHER ARCTIC FRONT MOVES ACROSS THE AREA THU OR FRI WITH GEFS AND ECENS ENSEMBLE POST FRONTAL 850 MEAN TEMPS VARYING FROM -15C TO -20C ACROSS SOUTHERN NEW ENGLAND. THUS COLDER THAN NORMAL TEMPS HOWEVER ANY RECORD BREAKING COLD SHOULD REMAIN WEST OF NEW ENGLAND ACROSS THE GREAT LAKES GIVEN PROXIMITY OF COLD AIR CORE. WILL ALSO HAVE TO WATCH FOR POTENTIAL SNOW SQUALLS ALONG AND AHEAD OF FRONTAL BOUNDARY...AS INCREASING SUN ANGLE /SAT MAR 1ST/ AND COLD AIR ALOFT WILL YIELD STEEP LOW LEVEL LAPSE RATES. THEN NEXT WEEKEND THE FOCUS WILL BE ON PACIFIC ENERGY MARCHING ACROSS THE SOUTHERN STATES AND ITS POSSIBLE INTERACTION/PHASING WITH THE NORTHERN STREAM OVER THE NORTHEAST. THE 00Z GEFS AND ECENS ENSEMBLE MEAN ARE WELL OFFSHORE WITH ANY CYCLOGENESIS...AS WELL AS THE 00Z GFS. THE 00Z ECMWF IS MUCH CLOSER TO THE COAST BUT ALSO WEAKER. GIVEN THE UNCERTAINTY WILL CONTINUE WITH CHANCE POPS FOR NEXT WEEKEND. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/... 7 AM UPDATE... NO MAJOR CHANGES FROM PREVIOUS 06Z TAFS. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ TODAY AND TUESDAY...HIGH CONFIDENCE. MAINLY VFR THROUGH THE PERIOD...BUT SOME LOW CU BETWEEN 030-060 POSSIBLE THROUGH DAYLIGHT HOURS ALONG WITH SOME LIGHT SNOW SHOWERS POSSIBLE MAINLY W OF A IJD-ORH-EEN LINE TODAY. NW WINDS GUSTING 25-30 KT AT TIMES TODAY...W WINDS GUST 20-25 KT ON TUE. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... VFR ALONG WITH GUSTY WNW WINDS. THE EXCEPTION WILL BE WED WHEN WINDS WILL BRIEFLY RELAX. HOWEVER A PERIOD OF SNOW IS POSSIBLE WED WITH MVFR CONDITIONS. HIGHEST PROBABILITY OF SNOW AND MVFR CONDITIONS IS ACROSS SOUTHEAST MA WED. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. THROUGH TUESDAY...HIGH CONFIDENCE. W-NW WINDS WILL BE INCREASING THROUGH THE DAY TODAY WITH GUSTS WIDESPREAD 25-30 KT EXPECTED. A FEW GUSTS MAY APPROACH GALE FORCE...BUT THE MAJORITY SHOULD REMAIN BELOW. THESE WINDS WILL MAINTAIN THROUGH THE OVERNIGHT HOURS TONIGHT...ONLY DIMINISHING INTO THE MORNING HOURS FOR TUE THEN DROPPING BELOW SMALL CRAFT THRESHOLDS BY THE LATE DAY TUE. WITH INCREASING WINDS EXPECT SEAS TO BUILD AS WELL...REACHING 5-7FT AT TIMES MAINLY ON THE OCEAN WATERS. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... GUSTY WNW WINDS AND PERIODS OF FREEZING SPRAY ARE EXPECTED AS ARCTIC AIR OVERSPREADS THE REGION. WINDS BRIEFLY RELAX WED AS ONE AREA OF LOW PRES TRACKS ACROSS SOUTHEAST CANADA AND A POTENTIAL GALE CENTER PASSES SOUTHEAST OF 40N/70W BENCHMARK. A PERIOD OF SNOW WITH REDUCED VSBY IS LIKELY WED ESPECIALLY OVER THE WATERS SOUTHEAST OF NANTUCKET. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST TUESDAY FOR ANZ230>237-251. SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR ANZ250-254>256. && $$ SYNOPSIS...NOCERA/DOODY NEAR TERM...NOCERA/DOODY SHORT TERM...DOODY LONG TERM...NOCERA AVIATION...NOCERA/DOODY MARINE...NOCERA/DOODY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
357 AM EST MON FEB 24 2014 .SYNOPSIS... A STRONG COLD FRONT CROSSES THE REGION TONIGHT...BRINGING PROGRESSIVELY COLDER CONDITIONS THROUGH NEXT WEEKEND. MAINLY DRY CONDITIONS WILL BE IN PLACE AS LARGE HIGH PRESSURE MOVES ACROSS. ONE EXCEPTION WILL BE FOR THE RISK OF ACCUMULATING SNOWFALL FOR WEDNESDAY AS LOW PRESSURE DEVELOPS WELL SOUTH OF NEW ENGLAND. ANOTHER LOW MAY BRING SOME SNOWFALL NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A COMBINATION OF BOTH OBS AND MSAS SUGGEST SFC COLD FRONT HAS MOVED OFFSHORE OF ALL SRN NEW ENGLAND COASTLINES SAVE FOR THE CAPE/ISLANDS AS OF 0830Z. NOW IN CLOSE ASSOCIATION WITH THIS FRONT IS A BAND OF WSR-88D ECHOS OF 25-30 DBZ WHICH ALSO CONTINUE TO GRADUALLY SLIDE OFF THE S COAST AND SHOULD BE OFFSHORE OF EVERYWHERE BY 10-12Z BASED ON CURRENT SPEED AND TIMING. DESPITE THE ECHOS...PRECIP HAS REALLY STRUGGLED TO REACH THE SFC THANKS TO 10-15F DWPT DEPRESSIONS ACROSS THE REGION. EVEN THEN...WITH SFC TEMPS ABOVE FREEZING AND A LACK OF HEAVY PRECIP TO FORCE THE NEAR SFC LAYER TO WET-BULB...ANY PRECIP THAT HAS REACHED THE SFC HAS BEEN IN THE FORM OF LIGHT RAIN. BASED EARLY MORNING POPS ON THE LATEST RAP WHICH CONTINUES TO FOLLOW THIS BAND WELL BUT CAPPED ANY POPS AT CHANCE. OTHERWISE TODAY...AFTER THE FRONT/PRECIP BAND SHIFTS OFFSHORE...STRONG COLD ADVECTION WILL DEFINE THE WX. H85 TEMPERATURES WILL BE DECLINING FROM AN AVERAGE OF ABOUT -5C TO ABOUT -16C BY THE OVERNIGHT HOURS TONIGHT. DRY AIR WILL ALSO BE RAPIDLY MOVING IN WITH TIME AS WELL. THEREFORE...EXPECT HIGH TEMPS TO OCCUR BY LATE THIS MORNING WITH COOLING EXPECTED THROUGH THE AFTERNOON HOURS...WITH RANGES FROM THE LOW TO UPPER 30S. THE COMBINATION OF STRONG CYCLONIC CURVATURE ALOFT WITH A SHORTWAVE MOVING ACROSS THE AREA...STEEP SFC-H9 LAPSE RATES ON THE ORDER OF 8C/KM AND A BIT OF TRAPPED MID LVL MOISTURE BENEATH A BUILDING SUBSIDENCE INVERSION WILL LIKELY YIELD WIDESPREAD CU-STRATOCU ACROSS THE AREA DURING PEAK HEATING. THE DEEP NEAR SFC UNSTABLE LAYER MAY ALSO BE ENOUGH TO INDUCE SOME LOCALIZED FLURRY ACTIVITY ESPECIALLY IN THE W WHERE CAA WILL BE MAXIMIZED. HAVE ADDED SOME SLIGHT CHANCE POPS TO THE FORECAST ALONG WITH THE INCREASING CLOUDS. OCEAN EFFECT CLOUDS ARE ALSO POSSIBLE ACROSS PORTIONS OF CAPE COD GIVEN THE WIND TRAJECTORY AND OCEAN BL INSTABILITY. ALSO...WITH THIS DEEP LAYER MIXING...MUCH OF THE MOMENTUM IN A NEARLY 40 KT LLJ SHOULD BE TAPPED. THEREFORE...EXPECT BRISK NW WINDS GUSTING 30-35 MPH AT TIMES THROUGH THE DAY. THIS WILL MAKE FOR WIND CHILL VALUES IN THE 20S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... TONIGHT... NOT TOO MUCH CHANGE FROM THE DAY AS CYCLONIC CURVATURE...DECENT SFC PRES GRADIENT AND TRAPPED MID LVL MOISTURE REMAIN IN PLAY ACROSS THE AREA. THEREFORE..EXPECT AT LEAST SOME CLOUDS AND WINDS TO REMAIN THROUGH THE OVERNIGHT HOURS. WHILE THIS WILL LIMIT THE ABILITY TO RADIATE...NORMAL DIURNAL TRENDS SHOULD STILL ALLOW MINS INTO THE LOW TEENS AND 20S. WITH WINDS OF AROUND 10 MPH STILL POSSIBLE...THIS WOULD YIELD SOME WIND CHILLS BELOW ZERO FOR PORTIONS OF THE INTERIOR AND IN THE SINGLE DIGITS CLOSER TO THE SHORELINES. TUESDAY... A COLD AND BRISK START IS EXPECTED AS WINDS CONTINUE TO GUST UP TO ABOUT 20 MPH AFTER SUNRISE AND MIXING SETS UP. ANOTHER ROUND OF PARTLY CLOUDY CONDITIONS AND HIGHER SUN ANGLES SHOULD ALLOW HIGHS TO INCREASE INTO THE MID 20S TO LOW 30S DESPITE THIS COOLER START BUT WITH WIND CHILL VALUES IN THE TEENS TO LOW 20S. MAINLY DRIER WX AS NOSE OF HIGH PRES BEGINS TO BUILD OVER FROM THE SW...LIMITING THE POTENTIAL FOR MORE FLURRY ACTIVITY IN COMPARISON TO MON. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * JANUARY-LIKE TEMPERATURES THIS WEEK AND AS WE ENTER MARCH NEXT WEEKEND * RISK FOR ACCUMULATING SNOW WED AND AGAIN NEXT WEEKEND * OTHERWISE MAINLY DRY CONDITIONS PREVAIL SYNOPTIC OVERVIEW... NOT MUCH CHANGE IN THE FORECAST FROM PREVIOUS DAYS. HIGH AMPLITUDE NORTHERN STREAM PATTERN DEVELOPS WITH POLAR VORTEX BEING DISPLACED SOUTHWARD INTO ONTARIO BY THU. THIS RESULTS IN A STEADY STREAM OF ARCTIC AIR INTO SOUTHERN NEW ENGLAND THIS WEEK AND INTO NEXT WEEKEND. THAT/S THE EASY PART OF THE FORECAST. WHAT BECOMES DIFFICULT TO NAIL DOWN AT THIS TIME RANGE IS THE INTENSITY AND TRACK OF ANY EAST CYCLOGENESIS...AS ARCTIC SHORT WAVES PIVOT AROUND THE SOUTHERN BASE OF THE POLAR VORTEX. FURTHER COMPLICATING THE FORECAST IS IF PACIFIC ENERGY UNDERCUTTING THE WESTERN RIDGE INTERACTS /PHASING VS UNPHASED/ WITH ARCTIC SHORT WAVE TROUGHS ALONG THE EAST COAST. MODEL PREFERENCES AND SENSIBLE WEATHER... WEDNESDAY...00Z DETERMINISTIC GFS AND ECMWF IN AGREEMENT ON AN UNPHASED SOLUTION WITH NORTHERN STREAM LOW MOVING ACROSS SOUTHEAST CANADA AND EAST COAST CYCLOGENESIS TRACKING WELL SOUTHEAST OF 40N/70W BENCHMARK. HOWEVER APPEARS THERE WILL BE ENOUGH MID LEVEL LIFT TO INDUCE AN INVERTED SURFACE TROUGH BETWEEN THESE TWO LOWS TO GENERATE A FEW TENTHS OF QPF OVER SOUTHERN NEW ENGLAND. THUS A LOW TO MODERATE RISK OF A FEW FLUFFY INCHES OF SNOW...WITH HIGHEST RISK OVER SOUTHEAST MA. HOWEVER CAN/T COMPLETELY RULE OUT A STRONGER/PHASED SOLUTION AS ARCTIC SHORT WAVE/PV ANOMALY THAT INDUCES EAST COAST CYCLOGENESIS IS CURRENTLY MOVING ACROSS NORTHWEST CANADA EARLY THIS MORNING. MODELS LIKELY NOT SAMPLING THIS PACKET OF JET ENERGY VERY WELL GIVEN THIS IS A DATA SPARSE AREA. THUS WILL HAVE TO WAIT UNTIL THIS FEATURE ENTERS SOUTHERN CANADA BEFORE MODELS BEGIN BETTER SAMPLING OF THIS JET ENERGY. IF THIS SHORT WAVE TROUGH IS MORE AMPLIFIED THAN MODELS CURRENTLY SIMULATE...A TRACK CLOSER TO THE COAST IS PLAUSIBLE. THEREFORE ITS STILL TOO EARLY TO LOCK INTO A SINGLE SCENARIO. HOWEVER FOR THE MOMENT WILL PLAY THE MOST LIKELY SCENARIO...A LOW TO MODERATE RISK OF A FEW INCHES OF FLUFFY SNOW. THURSDAY THRU SUNDAY...ANOTHER ARCTIC FRONT MOVES ACROSS THE AREA THU OR FRI WITH GEFS AND ECENS ENSEMBLE POST FRONTAL 850 MEAN TEMPS VARYING FROM -15C TO -20C ACROSS SOUTHERN NEW ENGLAND. THUS COLDER THAN NORMAL TEMPS HOWEVER ANY RECORD BREAKING COLD SHOULD REMAIN WEST OF NEW ENGLAND ACROSS THE GREAT LAKES GIVEN PROXIMITY OF COLD AIR CORE. WILL ALSO HAVE TO WATCH FOR POTENTIAL SNOW SQUALLS ALONG AND AHEAD OF FRONTAL BOUNDARY...AS INCREASING SUN ANGLE /SAT MAR 1ST/ AND COLD AIR ALOFT WILL YIELD STEEP LOW LEVEL LAPSE RATES. THEN NEXT WEEKEND THE FOCUS WILL BE ON PACIFIC ENERGY MARCHING ACROSS THE SOUTHERN STATES AND ITS POSSIBLE INTERACTION/PHASING WITH THE NORTHERN STREAM OVER THE NORTHEAST. THE 00Z GEFS AND ECENS ENSEMBLE MEAN ARE WELL OFFSHORE WITH ANY CYCLOGENESIS...AS WELL AS THE 00Z GFS. THE 00Z ECMWF IS MUCH CLOSER TO THE COAST BUT ALSO WEAKER. GIVEN THE UNCERTAINTY WILL CONTINUE WITH CHANCE POPS FOR NEXT WEEKEND. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/... THROUGH 12Z...MODERATE CONFIDENCE. A FEW LIGHT SNOW/RAIN SHOWERS WILL SKIRT CT/RI/SE MA TERMINALS. LITTLE IF ANY ACCUMULATION IS EXPECTED...BUT THE BEST CHANCE WILL BE ACROSS SE MA. MAINLY VFR...BUT A SHORT PERIOD OF MVFR CONDITIONS ARE POSSIBLE IN ANY SHOWERS. TODAY AND TUESDAY...HIGH CONFIDENCE. MAINLY VFR THROUGH THE PERIOD...BUT SOME LOW CU BETWEEN 030-060 POSSIBLE THROUGH DAYLIGHT HOURS ALONG WITH SOME LIGHT SNOW SHOWERS POSSIBLE MAINLY W OF A IJD-ORH-EEN LINE TODAY. NW WINDS GUSTING 25-30 KT AT TIMES TODAY...W WINDS GUST 20-25 KT ON TUE. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... VFR ALONG WITH GUSTY WNW WINDS. THE EXCEPTION WILL BE WED WHEN WINDS WILL BRIEFLY RELAX. HOWEVER A PERIOD OF SNOW IS POSSIBLE WED WITH MVFR CONDITIONS. HIGHEST PROBABILITY OF SNOW AND MVFR CONDITIONS IS ACROSS SOUTHEAST MA WED. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. THROUGH TUESDAY...HIGH CONFIDENCE. W-NW WINDS WILL BE INCREASING THROUGH THE DAY TODAY WITH GUSTS WIDESPREAD 25-30 KT EXPECTED. A FEW GUSTS MAY APPROACH GALE FORCE...BUT THE MAJORITY SHOULD REMAIN BELOW. THESE WINDS WILL MAINTAIN THROUGH THE OVERNIGHT HOURS TONIGHT...ONLY DIMINISHING INTO THE MORNING HOURS FOR TUE THEN DROPPING BELOW SMALL CRAFT THRESHOLDS BY THE LATE DAY TUE. WITH INCREASING WINDS EXPECT SEAS TO BUILD AS WELL...REACHING 5-7FT AT TIMES MAINLY ON THE OCEAN WATERS. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... GUSTY WNW WINDS AND PERIODS OF FREEZING SPRAY ARE EXPECTED AS ARCTIC AIR OVERSPREADS THE REGION. WINDS BRIEFLY RELAX WED AS ONE AREA OF LOW PRES TRACKS ACROSS SOUTHEAST CANADA AND A POTENTIAL GALE CENTER PASSES SOUTHEAST OF 40N/70W BENCHMARK. A PERIOD OF SNOW WITH REDUCED VSBY IS LIKELY WED ESPECIALLY OVER THE WATERS SOUTHEAST OF NANTUCKET. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST TUESDAY FOR ANZ230>237-251. SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST TUESDAY FOR ANZ250-254>256. && $$ SYNOPSIS...NOCERA/DOODY NEAR TERM...DOODY SHORT TERM...DOODY LONG TERM...NOCERA AVIATION...NOCERA/DOODY MARINE...NOCERA/DOODY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1241 AM EST MON FEB 24 2014 .SYNOPSIS... A STRONG COLD FRONT CROSSES THE REGION TONIGHT...BRINGING PROGRESSIVELY COLDER CONDITIONS THROUGH NEXT WEEKEND. MAINLY DRY CONDITIONS WILL BE IN PLACE AS LARGE HIGH PRESSURE MOVES ACROSS. ONE EXCEPTION WILL BE FOR THE RISK OF ACCUMULATING SNOWFALL FOR WEDNESDAY AS LOW PRESSURE DEVELOPS WELL SOUTH OF NEW ENGLAND. ANOTHER LOW MAY BRING SOME SNOWFALL NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1 AM UPDATE... BAND OF PRECIP CONTINUES TO WORK INTO CT AROUND MIDNIGHT WITH SOME 25-30 DBZ RETURNS APPARENT. HOWEVER...WITH DWPT DEPRESSIONS REMAINING IN THE 10-15F RANGE...THESE ECHOS ARE LIKELY NOT REACHING THE GROUND FOR THE MOST PART. OBS SITES ACROSS SRN NY DO SHOW SOME LIGHT RAINFALL...BUT IT WILL LIKELY TAKE A BIT LONGER TO CREEP INTO SRN NY. CURRENT HRRR SEEMS TO BE HANDLING THE PRECIP CHANCES BEST SO POPS WERE TRENDED TOWARD ITS THINKING...SUGGESTING A LIGHT BAND OF SN/RA MOVES ACROSS CT/RI/SE MA THROUGH ABOUT 12Z. SHOULD PRECIP REMAIN LIGHT...MANY LOCATIONS MAY START AS RAIN OR NEVER CHANGE OVER AT ALL...BUT CONTINUE SUGGEST SOME SNOWFALL IF THE HIGHER DBZ ECHOS ARE ACTUALLY REACHING THE GROUND. MEANWHILE THE COLD FRONT IS IN CENTRAL CT VALLEY AND THROUGH SRN NH. SO IT IS CATCHING UP WITH THE PRECIP BAND. INCREASING THE LIKELIHOOD FOR ENHANCED PRECIP AS THE NEAR SFC LIFT WILL BE STRENGTHENED. IT WILL LIKELY FOLLOW THE FRONT OFFSHORE THROUGH 12Z PER LATEST HRRR. PREVIOUS DISCUSSION... A STRONG COLD FRONT CROSSES THE REGION TONIGHT...BRINGING A RETURN TO COLDER WEATHER. AT THE SAME TIME...A SHORTWAVE WILL APPROACH FROM THE SOUTHWEST. THIS MAY BRING A BRIEF PERIOD OF LIGHT PRECIP LATE TONIGHT...TO THE SOUTH OF THE MA TURNPIKE. THIS DISTURBANCE ONLY CONTAINS A NARROW AXIS OF DEEP MOISTURE AND IS FAIRLY PROGRESSIVE. THEREFORE...EXPECT PRECIP AMOUNTS TO BE QUITE LIGHT. IN FACT...BOUNDARY LAYER IS INITIALLY WARM ENOUGH TO SUPPORT LIGHT RAIN AT THE ONSET IN SOME AREAS BEFORE A CHANGE TO LIGHT SNOW. WITH ALL THAT SAID...A DUSTING TO MAINLY LESS THAN 1 INCH OF SNOW IS POSSIBLE TO THE SOUTH OF THE MA TURNPIKE LATE TONIGHT. ANY LIGHT SNOW WILL BE PRETTY MUCH DONE BY DAYBREAK...BUT A FEW SLICK SPOTS WILL BE POSSIBLE FOR THE AM RUSH. LOW TEMPS BY DAYBREAK MONDAY WILL MAINLY BE IN THE 20S...TO PERHAPS SOME LOWER 30S ALONG THE FAR SOUTHEAST NEW ENGLAND COAST. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... ***MUCH COLDER AND WINDY WEATHER RETURNS ON MONDAY*** MONDAY... A MUCH COLDER AND WINDY DAY FOLLOWS TONIGHT/S COLD FRONTAL PASSAGE. HIGH TEMPS WILL ONLY RECOVER INTO THE UPPER 20S TO MIDDLE 30S...AS NORTHWEST WINDS GUST TO BETWEEN 25 AND 35 MPH LATE IN THE MORNING/AFTERNOON. WHILE A FAIR AMOUNT OF SUNSHINE IS EXPECTED ALONG THE COASTAL PLAIN EARLY...A DECK OF SCATTERED TO BROKEN DIURNAL CUMULUS CLOUDS WILL WORK ACROSS THE REGION FROM THE WEST AS THE DAY WEARS ON. A BRIEF PASSING FLURRY/SNOW SHOWER OR TWO WILL ALSO BE POSSIBLE...BUT THE INFILTRATION OF DRIER AIR WILL PROBABLY PREVENT LOCALIZED HEAVIER SNOW SHOWERS/SQUALLS. MONDAY NIGHT... DRY...BUT COLD AND BLUSTERY WEATHER CONTINUES ACROSS SOUTHERN NEW ENGLAND. NORTHWEST FLOW AND COLD ADVECTION WILL RESULT IN MOST LOCATIONS BOTTOMING OUT IN THE TEENS BY DAYBREAK TUESDAY. WIND CHILLS WILL DIP INTO THE SINGLE DIGITS ACROSS MOST OF THE REGION. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * TEMPERATURES WILL STEADILY FALL AS ARCTIC AIR WORKS INTO THE REGION THROUGH NEXT WEEKEND * LOW PRESSURE PASSING SOUTH OF NEW ENGLAND WILL INCREASE CHANCES FOR ACCUMULATING SNOWS WEDNESDAY * ANOTHER LOW IS POSSIBLE DURING NEXT WEEKEND WHICH COULD BRING SOME ACCUMULATING SNOW OVERVIEW AND MODEL PREFERENCES... MEDIUM RANGE MODELS AND ENSEMBLES CONTINUE TO SIGNAL DEVELOPMENT OF LONGITUDINAL RIDGING ACROSS THE EASTERN PACIFIC TO ALASKA... WHICH IN RETURN WILL BRING ANOTHER ROUND OF ARCTIC AIR FROM THE NORTH POLE AND NORTHERN CANADA TOWARD THE CENTRAL AND EASTERN U.S. WITH CUTOFF H5 LOW TAKING UP RESIDENCE NEAR HUDSON AND JAMES BAYS. PRIOR TO THIS SETTING UP...NOTING A GOOD SHORT WAVE IN THIS FLOW MOVING OUT OF SASKATCHEWAN AND MANITOBA EARLY TUE. THIS WILL CARVE OUT A GOOD LONG WAVE TROUGH PROGRESSING E LATER TUE AND WED. AT THE SURFACE...WILL SEE DEVELOPING LOW PRES CROSSING THE GREAT LAKES WHILE ANOTHER SYSTEM WILL MOVE OUT OF THE NORTHERN GULF OF MEXICO BY LATE TUE. THE SYSTEM REMAINS PROGRESSIVE...THOUGH WITH THE COLD AIR IN PLACE...THERE IS A GOOD RISK FOR ACCUMULATING SNOWS. SOME MODEL SPREAD NOTED ESPECIALLY WITH QPF VALUES AND HOW FAR NORTH THESE PROGRESS. ALSO UNCERTAIN WHETHER THESE SYSTEMS PHASE...THOUGH LAST SEVERAL RUNS HAVE SUGGESTED THEY REMAIN SEPARATE WITH THE SOUTHERN LOW PASSING WELL SE OF THE 40N/70W BENCHMARK. BEYOND MID WEEK...HEART OF ARCTIC AIR SLOWLY WORKS S OUT OF CENTRAL AND EASTERN CANADA...THOUGH COLDEST AIR DOES NOT LOOK TO ARRIVE UNTIL LATE NEXT WEEK. H85 TEMPS PROGRESSIVELY DROP THROUGH THE END OF THIS WEEK...AS LOW AS -15C TO -20C LATE THU AND FRI. THIS TRANSLATES TO DAYTIME HIGHS STRUGGLING TO REACH FREEZING INTO NEXT WEEKEND. NOTING ANOTHER LOW WORKING OUT OF THE SOUTHERN PLAINS STATES LATE NEXT WEEK THAT WILL TRY TO MOVE NE WHILE ANOTHER H5 SHORT WAVE MOVES ACROSS THE GREAT LAKES DURING THIS WEEKEND. RATHER WIDE MODEL SPREAD IN HOW THIS EVOLVES ALONG THE EASTERN SEABOARD. MAY SEE ANOTHER ROUND OF PRECIP SOMETIME DURING THIS TIMEFRAME. THIS LOOKS TO LEAD INTO NEAR RECORD LEVEL TEMPS FOR NEXT SUNDAY INTO EARLY NEXT WEEK. BASED ON THE MODEL TRENDS FOR COLDER CONDITIONS...USED THE COLDER HPC GUIDANCE FOR TEMPS/DEWPTS FOR THE MID-LATE WEEK. MOS GUIDANCE TENDS TO RUN CLOSER TO CLIMO THIS FAR OUT. AS FOR POPS...LEANED TOWARD A GENERAL BLEND OF THE 00Z GFS/12Z AND 00Z EC ALONG WITH THEIR ENSEMBLES. DETAILS... TUESDAY...DRY CONDITIONS BETWEEN SYSTEMS EXPECTED DURING THE DAY TUE...THOUGH CLOUDS WILL INCREASE. EXPECT CHANCE POPS TO MOVE INTO THE CT VALLEY AND S COAST WELL AFTER MIDNIGHT. WEDNESDAY...LOW PRES PASSES WELL SE OF BENCHMARK WHILE WEAK REFLECTION TO UPPER SYSTEM MOVES ALONG THE CANADIAN BORDER. QUESTION IS HOW MUCH QPF WORKS N FROM THE SOUTHERN STREAM SYSTEM. ECMWF LOOKS TO BE VERY BULLISH ON THIS...WHILE NAM IS WEAKEST. WENT WITH A MIDDLE OF THE ROAD SOLUTION...WITH QPF VALUES OF 0.1 INCHES ACROSS S NH TO 0.25 TO 0.4 INCHES ALONG THE S COAST...CAPE COD AND THE ISLANDS. LOOKS LIKE TEMPS AND THERMAL PROFILES FAVOR ALL SNOW...SO COULD SEE DECENT ACCUMULATING SNOWFALL ALONG THE S COAST. SOMETHING TO MONITOR CLOSELY...ESPECIALLY IF MORE QPF WORKS NW FROM THE SOUTHERN LOW. DOES LOOK LIKE THE PRECIP SHOULD BE PROGRESSIVE...SO PRECIP SHOULD EXIT WED NIGHT. W-NW WINDS BECOME GUSTY LATE WED NIGHT AS LOW EXITS THURSDAY AND FRIDAY...LARGE HIGH PRES BUILDS OUT OF CENTRAL AND WESTERN CANADA...BRINGING FIRST BATCH OF ARCTIC AIR TO THE REGION. EXPECT DRY AND COLD CONDITIONS. BRISK NW WINDS IN PLACE...GUSTS UP TO 25 TO 30 MPH ALONG THE COAST AND ESPECIALLY CAPE COD AND THE ISLANDS. SATURDAY-SUNDAY...MODEL SPREAD LENDS TO LOW CONFIDENCE WITH THE POSSIBLE APPROACH OF LOW PRES OUT OF THE SE U.S. LOW CHANCE OF MORE ACCUMULATING SNOWS DURING THIS TIMEFRAME. ANOTHER SHOT OF NEAR RECORD COLD AIR FOR EARLY MARCH IS ALSO POSSIBLE. && .AVIATION /05Z MONDAY THROUGH FRIDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/... THROUGH 12Z...MODERATE CONFIDENCE. A FEW LIGHT SNOW/RAIN SHOWERS WILL SKIRT CT/RI/SE MA TERMINALS. LITTLE IF ANY ACCUMULATION IS EXPECTED...BUT THE BEST CHANCE WILL BE ACROSS SE MA. MAINLY VFR...BUT A SHORT PERIOD OF MVFR CONDITIONS ARE POSSIBLE IN ANY SHOWERS. TODAY AND TUESDAY...HIGH CONFIDENCE. MAINLY VFR THROUGH THE PERIOD...BUT SOME LOW CU BETWEEN 030-060 POSSIBLE THROUGH DAYLIGHT HOURS ALONG WITH SOME LIGHT SNOW SHOWERS POSSIBLE MAINLY W OF A IJD-ORH-EEN LINE TODAY. NW WINDS GUSTING 25-30 KT AT TIMES TODAY...W WINDS GUST 20-25 KT ON TUE. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... WEDNESDAY...AREAS OF MVFR-IFR CONDITIONS IN SNOW DURING THE DAY. EXPECT IMPROVING CONDITIONS FROM W-E LATE WED INTO EARLY WED NIGHT. VFR LATE. GUSTY W-NW WINDS DURING WED NIGHT...HIGHEST ALONG COAST. THURSDAY...VFR CONDITIONS. GUSTY NW WINDS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. TONIGHT...HIGH CONFIDENCE. SOUTHWEST WINDS SHIFT TO THE NORTHWEST BEHIND A COLD FRONT. GUSTS UP TO 25 KNOTS MAY DEVELOP TOWARDS 12Z AS COLD AIR ADVECTION GETS UNDERWAY. MAY ALSO SEE VISIBILITIES REDUCED BRIEFLY TO BETWEEN 1 AND 3 MILES BETWEEN 6Z AND 12Z IN A PERIOD OF LIGHT RAIN/SNOW SHOWERS. MONDAY AND MONDAY NIGHT....HIGH CONFIDENCE. NORTHWEST WIND GUSTS OF 25 TO 30 KNOTS EXPECTED UNDER STRONG COLD ADVECTION YIELDING EXCELLENT MIXING OVER THE OPEN WATERS. LOW PROBABILITY THAT A FEW AREAS BRIEFLY SEE GUSTS NEAR 35 KNOTS...BUT IT WOULD BE TOO BRIEF AND NOT WIDESPREAD ENOUGH FOR GALES. HOWEVER...SCA ADVISORIES ARE POSTED FOR ALL WATERS MONDAY AND MONDAY NIGHT. LIGHT FREEZING SPRAY IS EXPECTED TO DEVELOP MONDAY NIGHT UNDER STRONG COLD ADVECTION. OUTLOOK...TUESDAY THROUGH FRIDAY... TUESDAY...W-NW WINDS GUSTING TO 25-30 KT WITH SEAS AOA 5 FT...DIMINISHING TUE NIGHT. VSBYS LOWER ON SOUTHERN WATERS AFTER MIDNIGHT IN SNOW. WEDNESDAY...NW WINDS INCREASE...GUSTING UP TO 30 KT ON THE OUTER WATERS. SEAS BUILD UP TO 7 FT. LIGHT TO MODERATE FREEZING SPRAY LIKELY WED NIGHT. VSBY RESTRICTIONS IN SNOW AND PATCHY FOG. THURSDAY...NW WINDS GUSTING UP TO 30 KT THU...THEN SLOWLY DIMINISH THU NIGHT. SEAS UP TO 8 FT WITH LIGHT TO MODERATE FREEZING SPRAY LIKELY INTO THU NIGHT. FRIDAY...WINDS AND SEAS DIMINISH. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 5 AM EST TUESDAY FOR ANZ230>237-250-251-254>256. && $$ SYNOPSIS...FRANK/EVT NEAR TERM...FRANK/DOODY SHORT TERM...FRANK LONG TERM...EVT AVIATION...DOODY/EVT MARINE...FRANK/EVT
AREA FORECAST DISCUSSION
NWS MIAMI FL
246 PM EST MON FEB 24 2014 .DISCUSSION... A WEAK COLD FRONT CURRENTLY DRAPED ACROSS NORTHERN FLORIDA IS EXPECTED TO SLOWLY PUSH TO THE SOUTH THROUGH THE AFTERNOON AND EVENING. AS IT DOES...A FEW SHOWERS AND POSSIBLY AN ISOLATED THUNDERSTORM OR TWO MAY DEVELOP ACROSS MAINLY THE EAST COASTAL AREAS ENHANCED BY A WEAK SEA BREEZE THAT MAY DEVELOP. LATEST HRRR WINDS DEPICT A WEAK SEA BREEZE ALONG MAINLY THE BROWARD AND PALM BEACH COUNTY COASTS. MODELS DEPICT THE COLD FRONT AND ACCOMPANYING DEEPER MOISTURE FIELD TO BECOME NEARLY STATIONARY ACROSS SOUTH FLORIDA THROUGH TUESDAY WITH RAIN CHANCES REMAINING ALONG WITH LIGHT AND VARIABLE WINDS. KEPT SLIGHT CHANCES FOR THUNDERSTORMS TUESDAY AFTERNOON ALONG THE NORTHERN INTERIOR AND EAST COAST AS WELL WITH THE LINGERING BOUNDARY IN THE AREA. BY TUESDAY NIGHT INTO EARLY WEDNESDAY...THE FRONT IS EXPECTED TO BASICALLY WASH OUT IN PLACE. FLOW WILL THEN QUICKLY BECOME SOUTHWEST AND INCREASE LATE WEDNESDAY OUT AHEAD OF ANOTHER COLD FRONT POSITIONED ACROSS THE NORTHERN GULF OF MEXICO. THIS FRONT LOOKS TO BE A BIT STRONGER THAN THE LAST ONE AND SHOULD PUSH THROUGH SOUTH FLORIDA BY EARLY THURSDAY MORNING WITH BETTER CHANCES FOR SHOWERS. DID NOT INCLUDE A THUNDER MENTION AT THIS TIME DUE TO THE TIMING OF THE FRONT BEING DURING THE EARLY MORNING HOURS...ACCORDING TO THE ECMWF. THE GFS SOLUTION IS A BIT SLOWER BRINGING THE FRONT INTO SOUTH FLORIDA LATER IN THE AFTERNOON. IF THIS SOLUTION PANS OUT...THE COMBINATION OF FRONTAL FORCING AND DAYTIME HEATING WOULD YIELD THUNDERSTORM DEVELOPMENT. WILL NEED TO WATCH SUBSEQUENT MODEL RUNS CLOSELY FOR TIMING CHANGES. SHOWERS WILL LINGER THROUGH FRIDAY BEFORE DRY WEATHER RETURNS FOR THE WEEKEND. UPPER RIDGING WILL THEN BUILD ACROSS THE AREA FROM THE SOUTH KEEPING TEMPERATURES ABOVE NORMAL. && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST ALTHOUGH THERE COULD BE A BRIEF MVFR CIG/VSBY IN A FAST MOVING SHOWER AFT 20Z THROUGH THIS EVENING. A COLD FRONT NORTH OF LAKE OKEECHOBEE WILL KEEP SOUTH FLORIDA IN A GENERAL SW-W SURFACE WIND AND IT APPEARS THE FLOW IS TOO STRONG TO ALLOW A SEA BREEZE TO DEVELOP ALONG THE EAST COAST. SURFACE WIND BECOME L/V AFT 03Z. && .MARINE... WINDS OF 10 KNOTS OR LESS ARE EXPECTED TO CONTINUE ACROSS THE REGIONAL WATERS WITH SEAS OF 2 FEET OR LESS. A COLD FRONT IS FORECAST TO AFFECT THE REGIONAL WATERS EARLY THURSDAY WITH AN INCREASE IN WINDS AND SEAS EXPECTED. HOWEVER...HAZARDOUS SEAS ARE NOT FORECAST FOR THIS PERIOD. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 67 81 63 82 / 20 30 10 20 FORT LAUDERDALE 69 82 66 82 / 20 30 10 20 MIAMI 69 83 67 83 / 20 30 10 20 NAPLES 64 79 62 80 / 10 20 - 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...10/CD AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1013 PM EST TUE FEB 25 2014 .SYNOPSIS... A GULF COAST LOW PRESSURE SYSTEM WILL MOVE EAST THROUGH GEORGIA AND FLORIDA TONIGHT INTO WEDNESDAY BRINGING A CHANCE OF RAIN TO OUR AREA. DRY AND COOLER WEATHER IS EXPECTED THURSDAY AND FRIDAY WITH ANOTHER CHANCE OF RAIN EARLY SATURDAY WITH A FAST MOVING SYSTEM. && .NEAR TERM /THROUGH WEDNESDAY/... UPDATE...FORECAST REMAINS ON TRACK AS FRONT APPROACHES FROM THE WEST. HAVE ADJUSTED POPS AND CLOUDS TO BETTER REPRESENT CURRENT OBSERVATIONS WITH INCREASING CLOUDS AND CHANCES OF RAIN OVER THE NEXT SEVERAL HOURS. BEST CHANCES OF RAIN WILL BE OVER THE SOUTHERN MIDLANDS AND CSRA OVERNIGHT WITH RAIN SPREADING INTO THE CENTRAL MIDLANDS DURING THE EARLY MORNING HOURS. RAINFALL AMOUNTS THROUGH DAYBREAK ARE EXPECTED TO BE TWO TENTHS OF AN INCH OR LESS. TEMPERATURES REMAIN ON TRACK FOR LOWER 40S FOR THE NORTHERN AND WESTERN MIDLANDS WITH MID 40S TO AROUND 50 ELSEWHERE. PREVIOUS DISCUSSION...CHANCES OF RAIN INCREASE LATE TONIGHT AS BROAD UPPER TROUGH SINKS ACROSS THE GREAT LAKES AND OHIO VALLEY REGION DRIVING A COLD FRONT THROUGH THE FORECAST AREA EARLY WEDNESDAY MORNING BEFORE HIGH PRESSURE BUILDS IN AT THE SURFACE BEHIND THE FRONT WEDNESDAY AFTERNOON. WESTERLY LOW LEVEL FLOW AHEAD OF THE SHORTWAVE AND FRONT IS FORECAST TO BACK MORE SOUTHWESTERLY THIS EVENING ALLOWING FOR ATMOSPHERIC MOISTURE TO INCREASE WITH FLOW OFF THE WESTERN GULF OF MEXICO. HOWEVER...THE TIME FRAME FOR SIGNIFICANT MOISTURE TO MOVE INTO THE REGION BEFORE THE FRONT ARRIVES IS SHORT AND A LIMITING FACTOR DESPITE MODERATE UPPER DYNAMICS ARRIVING AROUND THE 12Z TIME FRAME AS THE NORTHERN AND SOUTHERN STREAM JETS COUPLE TO PROVIDE STRONG OMEGA AND UPWARD VERTICAL MOTION OVER THE FORECAST AREA. HAVE INCREASED POPS SLIGHTLY FROM PREVIOUS FORECAST...HIGHEST POPS FROM THE CSRA ACROSS THE SOUTHEAST MIDLANDS LATE TONIGHT INTO WEDNESDAY MORNING WITH A GRADIENT TO LOWER POPS TO THE NORTHWEST WHERE MOISTURE WILL NOT BE AS GREAT. STILL FIGURE THE BEST TIME FRAME FOR HIGHEST POPS WILL BE FROM 09Z-15Z WITH CHANCES OF RAIN DECREASING FROM NORTHWEST TO SOUTHEAST THROUGH THE DAY WEDNESDAY. LATEST 12Z NAM SOUNDINGS SUGGEST A MIX OF SNOW/RAIN POSSIBLE ACROSS THE NORTHERN MIDLANDS WEDNESDAY MORNING WITH DEEP MOISTURE INTO SNOW GROWTH ZONE AND NEAR SURFACE TEMPERATURES LIKELY IN THE 30S. CONFIDENCE IS LOW HOWEVER WITH LITTLE SUPPORT FROM GFS...I.E. NO MOISTURE IN SNOW GROWTH ZONE. STILL THINK HIGHER POPS WILL BE SOUTH OF THE NORTHERN MIDLANDS...BUT WILL INCLUDE CHANCE SNOW/RAIN SHOWERS ACROSS NORTHERN LANCASTER COUNTY WHERE PARTIAL THICKNESS SCHEMES FAVOR MIX. CLOUDINESS LATE TONIGHT SHOULD KEEP TEMPERATURES FROM FALLING SOMEWHAT...FAVOR WARMER MAV GUIDANCE. TEMPERATURES WILL BE MUCH COOLER WEDNESDAY COMPARED TO TODAY WITH COLD ADVECTION TAKING PLACE DURING THE DAY DESPITE SOME CLEARING SKIES BY AFTERNOON. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... WEDNESDAY NIGHT...THE LOW PRESSURE SYSTEM AND ALL ASSOCIATED PRECIPITATION WILL BE WELL OFFSHORE BY WEDNESDAY NIGHT. COLD AIR ADVECTION AND DECENT RADIATIONAL COOLING CONDITIONS WILL LEAD TO BELOW NORMAL OVERNIGHT LOW TEMPERATURES...IN THE UPPER 20S NORTH TO LOWER 30S SOUTH. THURSDAY THROUGH THURSDAY NIGHT...A BROAD UPPER TROUGH WILL MOVE OVER THE EASTERN CONUS ON THURSDAY PROMOTING WEST-NORTHWESTERLY FLOW ALOFT. AT THE SURFACE...LOW PRESSURE OVER THE GREAT LAKES REGION WILL BRING A DRY COLD FRONT THROUGH THE AREA. TEMPERATURES WILL MAX OUT IN THE MID 50S TO NEAR 60 UNDER SUNNY SKIES. SURFACE HIGH PRESSURE WILL SHIFT INTO THE OHIO VALLEY THURSDAY NIGHT ALLOWING SURFACE WINDS TO ROTATE FROM WESTERLY TO NORTHEASTERLY. MOSTLY CLEAR SKIES OVERNIGHT WILL SET THE STAGE FOR ANOTHER CHILLY NIGHT WITH LOWS IN THE UPPER 20S TO NEAR 30. FRIDAY THROUGH FRIDAY NIGHT...THE UPPER TROUGH WILL BE OFF THE COAST BY FRIDAY WITH UPPER FLOW BECOMING ZONAL. SURFACE HIGH PRESSURE WILL SHIFT OVER THE MID-ATLANTIC AND WEDGE INTO THE FORECAST AREA FOR FRIDAY. TEMPERATURES WILL MAX OUT IN THE UPPER 40S NORTH TO MID 50S SOUTH. A WEAK SHORTWAVE TROUGH WILL BRING A CHANCE OF PRECIPITATION FRIDAY NIGHT INTO EARLY SATURDAY. MOSTLY CLOUDY SKIES OVERNIGHT WITH LOW TEMPERATURES ABOVE FREEZING IN THE LOWER 30S TO NEAR 40. && .LONG TERM /FRIDAY THROUGH TUESDAY/... SHORTWAVE TROUGH WILL SHIFT EAST SATURDAY MORNING AS AN UPPER RIDGE BUILDS OVER THE SOUTHEAST CONUS THROUGH SUNDAY WITH DRY WEATHER EXPECTED. THE UPPER RIDGE WILL SHIFT EAST MONDAY AS A TROUGH BUILDS OVER THE WESTERN CONUS. SIGNIFICANT TIMING DIFFERENCES BETWEEN THE ECMWF AND GFS WITH THE NEXT SYSTEM ARRIVING DURING THE MONDAY/TUESDAY TIME FRAME. THE ECMWF IS A BIT QUICKER BRINGING THE SYSTEM THROUGH THAN THE GFS. BELOW NORMAL MAX TEMPERATURES ON SATURDAY BUT OTHERWISE NEAR NORMAL HIGHS IN THE 60S FOR THE REST OF THE EXTENDED. LATEST GUIDANCE HAS CONTINUED TO TREND UP WITH TEMPERATURES FOR SUNDAY AND MONDAY. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... EXPECT MAINLY VFR CONDITIONS DURING THE TAF PERIOD BUT CONFIDENCE IS NOT HIGH. A COLD FRONT WILL SINK SOUTHWARD AND THROUGH THE AREA TONIGHT. NORTHERLY WINDS WILL DEVELOP BEHIND THE FRONT DURING THE EARLY MORNING HOURS. EXPECT AN INCREASE IN CLOUDINESS AND THE DEVELOPMENT OF RAIN OVER MOST OF THE AREA DURING THE EARLY MORNING HOURS MAINLY ASSOCIATED WITH A COUPLED H25 JET PATTERN. THE LATEST HRRR SHOWED COVERAGE UPSTREAM INCREASING AND MOVING INTO THE FORECAST AREA AROUND 10Z. CONFIDENCE IS LOW WITH THE CEILING AND VISIBILITY FORECAST BECAUSE OF MODEL INCONSISTENCY. THE NAM MOS INDICATED MVFR OR IFR CEILINGS. THE GFS MOS AND LAMP PLUS SREF GUIDANCE INDICATED CONTINUED VFR CEILINGS AND VISIBILITIES. THE 22Z HRRR INDICATED MAINLY VFR CONDITIONS THROUGH 13Z. WE LEANED TOWARD THE MORE OPTIMISTIC GUIDANCE BECAUSE OF THE H85 WESTERLY FLOW AND THE INITIAL DRYNESS. ALSO...A LACK OF SIGNIFICANT ISENTROPIC LIFT SHOULD HELP KEEP RAIN MAINLY LIGHT AND LIMIT ITS RESTRICTION TO VISIBILITY. THE NAM AND GFS SHOW UPPER-LEVEL LIFT SHIFTING EAST OF THE AREA BETWEEN 16 AND 18Z. RAIN AND LINGERING LOWER CLOUDINESS SHOULD DIMINISH DURING THIS TIME. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
828 PM MST TUE FEB 25 2014 .UPDATE... ISSUED AT 811 PM MST TUE FEB 25 2014 JUST COMPLETED ANOTHER UPDATE. BAND OF SNOW IS HOLDING TOGETHER VERY WELL DESPITE WHAT EARLIER MODEL OUTPUT SAID. STRONG MID LEVEL FRONTOGENESIS AND UPPER LEVEL DEFORMATION IS WORKING ITS WAY ACROSS. SNOW IS LIGHT PROBABLY DUE TO THE VERY POOR THETA-E LAPSE RATES BUT STILL IT IS GOING TO SNOW. SO RAISED POPS TO 100 PERCENT FOR THE REST OF THE EVENING AS THIS BAND WORKS ITS WAY SOUTH. WITH THE SLOWER PROGRESSION OF THE BAND AND LINGERING DYNAMICS...HAVE KEPT THE POPS GOING FOR A FEW HOURS AFTER 06Z. OTHERWISE MADE SLIGHT ADJUSTMENTS IN THE TEMPERATURES. UPDATE ISSUED AT 604 PM MST TUE FEB 25 2014 NICE BAND OF SNOW STILL OVER THE FAR NORTH AT THIS TIME WITH A SLOW SHIFT SOUTH. SOME UNCERTAINTY HOW FAR SOUTH THIS BAND WILL GET AND HOW FAST IT WILL DO IT. MESOSCALE GUIDANCE IS INDICATING THAT THIS BAND WILL THIN AND WEAKEN AS IT MOVES SOUTH. DO HAVE A RIGHT REAR QUADRANT OF JET AND STRONG PV ANOMALY MOVING IN FROM THE NORTHWEST. SO AM THINKING THE BAND WILL HOLD TOGETHER. SO UPPED UP POPS TO DEFINITE IN THE NORTH AND INCREASED THE REMAINING PORTION OF THE AREA SLIGHTLY. ALSO MADE A SLIGHT ADJUSTMENT TO THE WINDS BASED ON THE HRRR. LOOKS LIKE THERE WILL BE A QUICK AND DRAMATIC CLEARING TREND AFTER THE SNOW ENDS. WINDS WILL BE LIGHT FOR A LITTLE WHILE BEFORE PICKING UP LATER IN THE NIGHT. AM THINKING THAT WE HAVE THE POTENTIAL TO BE MUCH COLDER THAN CURRENTLY INDICATED. SO DID MAKE A SLIGHT ADJUSTMENT COLDER FOR THE NIGHT AND WILL CONTINUE TO WATCH THE TRENDS CLOSELY AND SEE WHAT THE NEWER GUIDANCE WILL TELL ME. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 113 PM MST TUE FEB 25 2014 MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2 INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS AROUND 5 TO 10 ABOVE ZERO. AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40 AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL AND SREF FOR TOMORROW`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
AREA FORECAST DISCUSSION
NWS GOODLAND KS
613 PM MST TUE FEB 25 2014 .UPDATE... ISSUED AT 604 PM MST TUE FEB 25 2014 NICE BAND OF SNOW STILL OVER THE FAR NORTH AT THIS TIME WITH A SLOW SHIFT SOUTH. SOME UNCERTAINTY HOW FAR SOUTH THIS BAND WILL GET AND HOW FAST IT WILL DO IT. MESOSCALE GUIDANCE IS INDICATING THAT THIS BAND WILL THIN AND WEAKEN AS IT MOVES SOUTH. DO HAVE A RIGHT REAR QUADRANT OF JET AND STRONG PV ANOMALY MOVING IN FROM THE NORTHWEST. SO AM THINKING THE BAND WILL HOLD TOGETHER. SO UPPED UP POPS TO DEFINITE IN THE NORTH AND INCREASED THE REMAINING PORTION OF THE AREA SLIGHTLY. ALSO MADE A SLIGHT ADJUSTMENT TO THE WINDS BASED ON THE HRRR. LOOKS LIKE THERE WILL BE A QUICK AND DRAMATIC CLEARING TREND AFTER THE SNOW ENDS. WINDS WILL BE LIGHT FOR A LITTLE WHILE BEFORE PICKING UP LATER IN THE NIGHT. AM THINKING THAT WE HAVE THE POTENTIAL TO BE MUCH COLDER THAN CURRENTLY INDICATED. SO DID MAKE A SLIGHT ADJUSTMENT COLDER FOR THE NIGHT AND WILL CONTINUE TO WATCH THE TRENDS CLOSELY AND SEE WHAT THE NEWER GUIDANCE WILL TELL ME. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 113 PM MST TUE FEB 25 2014 MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2 INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS AROUND 5 TO 10 ABOVE ZERO. AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40 AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL AND SREF FOR TOMORROW`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
AREA FORECAST DISCUSSION
NWS GOODLAND KS
457 PM MST TUE FEB 25 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 113 PM MST TUE FEB 25 2014 MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2 INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS AROUND 5 TO 10 ABOVE ZERO. AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40 AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL AND SREF FOR TOMORROW`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
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
946 PM EST Tue Feb 25 2014 ...Forecast Update... Issued at 945 PM EST Tue Feb 25 2014 Certainly a challenging overnight forecast. Our expected upper-level system is currently organizing across the Middle Mississippi Valley. It will advect eastward through the overnight hours, with light snow developing across the forecast area. The big issue is where the heaviest snow will fall. The 18Z GFS develops the snow band from Meade county eastward to Fayette and Clark counties. The 00Z NAM is a little farther south by about one or two counties and produces the heaviest snow farther east. The 00Z NAM seems to have shifted ever so slightly northward when compared to it`s 18Z run. The latest RAP (23Z at time of this writing) aligns pretty well with the GFS as far as location. However, the RAP has been hit-and-miss on producing accumulating snow until just the last few hourly cycles. The amounts are certainly less than the GFS by about half. This is reasonable given the current dewpoints across the area, as well as some dry air aloft. Dewpoints in the middle to upper teens are common, with a few sites at 20. Actual temperatures are ranging from the upper 20s to lower 30s. So, there is some dry air to overcome, but the current cloud deck overhead is working on that with some virga noticeable in the radar returns and light snow just to our northwest in Illinois. With all of this information, here is the current thinking. Believe the likely area for snow accumulation of around an inch would be along the Jefferson-Bullitt-Spencer county lines eastward to Fayette and Clark counties. The Blue Grass region still stands the best chance of accumulations at or slightly greater than one inch. The 21Z SREF probabilities of accumulations generally at or greater than one inch supports this current thinking. Although these SREF probs are fairly low, which likely means accumulations greater than an inch will be localized. This current thinking does not mean any adjustments to the advisory are warranted at this time. The greatest accumulations still fall within the advisory, and our Indiana counties are on tap to saturate first (evident in upstream obs). The question remains if it will snow long enough across our Indiana counties for adequate accums. Still a tough call, but certainly not worth dropping the advisory at this time since the snow is yet to fall. The next issue is whether Meade and Hardin (perhaps Perry IN, Hancock, Breckinridge, and Larue counties) should be added. Here, the NAM and RAP are currently preferred. Some accumulation is possible, yet still believe the totals closer to advisory criteria will be farther to the east. So, the bottom line is the advisory will remain as is until at least snow begins to fall and a better consensus can be made as to where the main band will become established. .SHORT TERM (Now through Wednesday Night)... Issued at 230 PM EST Tue Feb 25 2014 Fast-moving upper disturbance diving out of the Upper Midwest will be our main weather player in the near term, with the biggest challenge being the southward extent and actual impact of accumulating snows overnight. Mid-level dry layer will erode quickly this evening, allowing snow to break out mainly along the I-64 corridor before midnight. Models are in uncanny agreement, all showing high-end chance POPs, but given that this system could have impacts with just a trace of liquid, will bump POPs into the likely category across southern IN and the northern two thirds of KY. With a weak surface reflection, this will be a quick-hitting system with a fairly narrow time window to produce snow accumulations. Expect this system to traverse the area between 03Z and 11Z Wednesday. QPF is quite modest, but temps dropping quickly into the lower/mid-20s will support healthy snow to liquid ratios. At this point the best chance for an inch of snow appears to be along and north of a line from near Jasper, IN to Bardstown to Richmond, KY. Given that temps will be cold enough to limit the effectiveness of some road treatments, and travel impacts will linger into the morning commute, will go with a low-end Winter Weather Advisory for these areas. Snow should exit the Bluegrass region just before daybreak on Wednesday, giving way to clearing and cold conditions as Arctic high pressure builds from the Upper Midwest. The window of strongest NW winds appears to be narrowing, so wind chill values are not looking quite as cold as previously advertised. Still could see a couple hours of wind chills near zero along and north of I-64, with the best chance of subzero chill factors over southern Indiana. Afternoon temps will struggle into the mid/upper 20s, with some bust potential across northern sections depending on how much snow falls overnight. This pattern is very progressive, so temps will not have a chance to really bottom out Wednesday night as WSW return flow develops ahead of the next reinforcing cold front. .LONG TERM (Thursday through Tuesday)... Issued at 250 PM EST Tue Feb 25 2014 A number of questions remain concerning temperatures and precipitation types for the latter portion of the weekend, leading to a quite challenging forecast. The blocking ridge over our west coast will break down Thursday as a deep longwave trough will finally undercut 500mb ridging over the Pacific Northwest and bring widespread beneficial rains to California. This energy will then cross the desert Southwest Friday and Saturday, and will bring several bouts of precipitation to the Lower Ohio Valley this weekend and Monday of next week. Thursday through early Saturday... Arctic air will build south of the Ohio River during the day Thursday, in the wake of a cold front associated with a surface low moving across the Great Lakes. Due to antecedent dry air, expect only a few clouds, giving a mostly sunny day Thursday. Northwest winds will pick up during the morning hours, bring pretty raw and blustery conditions during the day. Highs Thursday may actually stay cooler than Wednesday and will range from the lower 20s across southern Indiana to the upper 20s near Tennessee. Thursday night may become bitterly cold, and will likely be the coldest night left in this "winter of our discontent". High pressure centered over Indiana may provide light winds and clear skies, which are optimal for good radiational cooling. Should these conditions develop, lows will easily reach the single digits across southern Indiana and the mid teens near Tennessee. An initial flat disturbance will eject eastwards of the southern plains and bring light precipitation to the area late Friday into early Saturday. Both the GFS and NAM develop an inverted surface trough that will extend from weak low pressure over the Texas Panhandle along the Ohio River. Isentropic lift along and just north of this feature will bring snow, or a rain snow mix to southern Indiana and north central Kentucky, ending Saturday morning. Even where precipitation is all snow, substantial accumulations are unlikely with the expected light QPF. Saturday through Monday... The main upper level trough across the desert southwest will eject into the Southern Plains late Sunday. A sharp inverted trough is still expected to lie somewhere along the Ohio River and will separate arctic air across the Great Lakes from a warm moist spring-like airmass across the Tennessee Valley. Also, both surface and 500mb ridging near Florida will ensure that rich Gulf moisture will move north and east along this trough. After a cloudy and seasonably cool day Saturday, widespread soaking precipitation will spread northeast along this inverted trough towards the Commonwealth by Sunday afternoon. A very sharp temperatures gradient will develop along this trough, possibly right along or near the Ohio River. Highs Sunday could easily vary from the mid 50s near Bowling Green to near 30 at Indianapolis. Substantial snow or a wintry mix is likely over parts of Indiana while rain is now looking likely over much of the Commonwealth. However, any rain/snow line will highly depend on where exactly this surface trough ends up and may change in later forecasts. Currently, the GFS operational model has rain as far north as far southern Indiana, while the much colder 12z Tuesday Canadian and the ECMWF models have snow all the way to just south of the Ohio. In any case, widespread precipitation will continue for much of Sunday night, sagging to the southeast towards central Tennessee and eastern Kentucky by early Monday. Many areas may receive an inch or more of QPF with this system. It is also possible that initial rain over Kentucky may change to snow early Monday as colder air filters in on the back edge of any precipitation. Monday night and Tuesday... Arctic high pressure will build south once again late Monday, bringing dry but cold temperatures Monday night and Tuesday. && .AVIATION (00Z TAF Update)... Updated at 637 PM EST Tue Feb 25 2014 A fast-moving upper wave will push across the Ohio Valley overnight, and will be enough to squeeze out some light snow. Best chance is 04Z-08Z at SDF and 05Z-09Z at LEX. The latest data and upstream obs indicate VFR conditions will prevail, however, the cig and vis may drop to high-end MVFR on a temporary basis. With this snow band expected to develop right over the region and varying guidance, pin-pointing the timing of reduced conditions remains a bit difficult. Northwest winds will increase to 10-15 knots during the snow. As the system departs the area prior to daybreak Wednesday, skies will become mostly clear/clear and northerly winds will diminishing with the Arctic high building in. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...WINTER WEATHER ADVISORY until 6 AM EST Wednesday FOR KYZ029>043- 045>049-056-057. IN...WINTER WEATHER ADVISORY until 6 AM EST /5 AM CST/ Wednesday FOR INZ076>079-083-084-090>092. && $$ Update.........MJP Short Term.....RAS Long Term......JSD Aviation.......MJP
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
338 PM EST MON FEB 24 2014 .SYNOPSIS... HIGH PRESSURE BUILDS ACROSS THE AREA TONIGHT INTO TUESDAY. LOW PRESSURE MOVES NORTHEAST ALONG THE MID ATLANTIC COAST LATE TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE RETURNS FOR LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... LATEST SFC ANALYSIS REVEALS ~1029 MB LO PRES CENTERED OVR THE MIDWEST AND A COLD FRNT PUSHING WELL OFF THE MID ATLANTIC CST. TIGHT PRES GRADIENT BETWEEN THESE TWO FEATURES HAS LED TO WNW WINDS GUSTING TO 20-30 MPH OVR THE MID ATLANTIC. THESE WINDS WILL DIMINISH FOLLOWING SUNSET WHILE HI PRES BLDS IN FRM THE WEST. EXPECT SOME INCREASING CLOUDS TNGT DUE TO INCREASING LO-LEVEL WAA AND MOISTURE ADVECTION WITHIN THE PROGRESSIVE WLY FLOW ALOFT. TEMPS WILL BE SLGTLY BLO NORMAL...WITH LOWS IN THE MID 20S TO LWR 30S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... SHORT TERM PERIOD WILL FEATURE UPR-LEVEL LO PRES CENTERED ACROSS CNTRL/ERN CANADA WITH CYCLONIC FLOW OVR THE ERN CONUS. APPROACHING MID-LEVEL SHORTWAVE TROF AND INCREASING MOISTURE WILL LEAD TO 20-30% POPS OVR FAR NRN AREAS TUE. BEST FORCING ASSOCIATED WITH THE TROF WILL PASS NORTH OF THE AREA. MODEL THICKNESSES AND SFC TEMPS SUPPORT A RAIN/SNOW MIX...WITH JUST SNOW OVR NRN EDGES OF THE FA. NO ACCUMULATIONS EXPECTED. OTHERWISE...EXPECT LGT WINDS WITH A MSTLY CLOUDY SKY AND HIGH TEMPS RANGING FRM THE LO/MID 40S NORTH TO UPR 40S/LWR 50S SOUTH. FOR TUE NGT...ATTENTION TURNS TO AN APPROACHING (STRONGER) SHORTWAVE TROF. COMBO OF DECENT MID/UPR-LEVEL FORCING AND MOISTURE INCREASE WILL LEAD TO ANOTHER CHANCE FOR PRECIP ACROSS THE MID ATLANTIC. LO TEMPS NEAR/BLO FREEZING IN MANY SPOTS AND CRASHING THICKNESSES WILL ALLOW FOR THE CHANCE OF SNOW OVR MOST OF THE AREA. DO THINK THAT SOME RAIN WILL BE MIXING IN OVR THE MID SECTION OF THE FA...WITH MSTLY A RAIN EVENT FOR THE TIDEWATER/NE NC. WITH THIS EVENT BEING SHORT IN DURATION AND TEMPS BEING MARGINAL (I.E. MELTING ISSUES)...ONLY EXPECTING ACCUMULATIONS FOR AREAS MAINLY NORTH OF RIC...THE NRN NECK AND THE LWR ERN SHORE. A COATING TO ONE INCH IS PSBL. THE BULK OF THE PRECIP WILL FALL FRM 9-15Z WED...WITH CONDITIONS QUICKLY DRYING OUT FRM WEST TO EAST WED AFTN AS SFC LO PRES DEVELOPS OFFSHORE AND PUSHES EWRD. HIGH TEMPS IN THE MID 30S TO LWR 40S. SFC HI PRES BLDS OVR THE SE US WED NGT. WITH CLEARING SKIES AND LGT WINDS...TEMPS WILL FALL INTO THE UPR TEENS TO LWR 20S. BLO NORMAL TEMPS CONTINUE INTO THU WITH A SUNNY SKY...HIGHS ONLY IN THE 40S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... COLDER WITH BELOW NORMAL TEMPS. A SPLIT FLOW WILL LEAD TO QUICK SYSTM MOVEMENTS AND PERIODIC PCPN CHCS THRU PRD. LEANED TOWARD THE ECMWF WITH RESPECT TO SFC FEATURES. CANADIAN HIGH PRESSURE KEEPS IT DRY BUT COLD FRIDAY. LOWS THURS NIGHT IN THE L-M20S XCPT A FEW UPR TEENS NRMLY COLDER SPOTS. HIGHS FRI M30S-L40S. NEXT IN A SERIES OF SRN STREAM S/W`S PROGGED TO TRACK ACROSS THE SOUTHERN MID ATLNTC REGION FRI NIGHT AND SAT. LATEST MODEL GUIDANCE WANTS TO SHEAR THE PCPN OUT AS IT CROSSES THE MTS FRI NIGHT WHILE TRACKING AN AREA OF MSTR FROM SRN VA ACROSS THE CAROLINAS LATE FRI NITE AND SAT MORN. UPSHOT HERE WILL BE YET ANTHR SYSTM WITH LGT AMOUNTS OF QPF. P-TYPE ISSUES ARISE GIVEN SFC TMPS AOB FREEZING AND CRITICAL THICKNESSES. WILL CARRY LOW CHC POPS FOR SNOW NWRN HALF OF FA...A BUFFER ZONE OF SNOW/SLEET DOWN TO VA/NC BORDER WITH A RAIN SLEET MIX ACROSS NC LATE FRI NITE. LOWS M20S-L30S. CHC LIQUID POPS ACROSS SERN SCTNS OF FA WITH A BUFFER ZONE OF MIXED RAIN/SNOW FRTHR NW SAT MORNING. PCPN ENDS MOST AREAS ARND NOON XCPT SOME LINGERING RAIN CHCS AT THE COAST SAT AFTRN. HIGHS IN THE 40S. ANTHR CANADIAN HIGH PRESSURE BUILDS INTO THE AREA SAT NIGHT THROUGH SUNDAY NITE. DRY AND COLD WITH LOWS SAT NITE UPR TEENS-M20S. HIGHS SUN M-U30S. LOWS SUN NIGHT IN THE 20S. MODELS INDCTG ANTHR COMPLICATED SYSTM POISED TO MAKE A BEELINE FOR THE MID ATLNTC RGN MONDAY. HIGH PRS TO THE NORTH ALLOWS FOR A WEDGE TO SET UP AHEAD OF A MOISTURE LADEN SYSTM DVLPNG ACROSS THE DEEP SOUTH. THE LOW PROGGED TO LIFT NORTH ACROSS THE RGN LATE MONDAY ALONG WITH A COLD FRONTAL PASSAGE. MOISTURE PROGGED TO RIDE UP OVER THE WEDGE PRODUCING A VARIETY OF WX ACROSS THE RGN SUN NITE AND MON MORN WITH PCPN BCMG RAIN OVR ERN HALF OF FA MON. TO ERLY TO GET SPECIFIC...BUT THIS SYSTM DOES BEAR WATCHING FOR THE PTNTL OF A WINTER MIX OF PCPN SUNDAY NIGHT THROUGH MONDAY MORN. LOWS SUN NITE 25-30. HIGHS MON IN THE 30S AND 40S. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... NW WIND SHOULD AVERAGE 8-12KT...WITH GUSTS TO AROUND 20KT AT RIC/SBY. HIGH PRESSURE BUILDS ACROSS THE REGION TONIGHT AND MOVES OFFSHORE TUESDAY. A LOW PRESSURE SYSTEM DEVELOPS OFF THE MID ATLANTIC COAST TUESDAY NIGHT AND WEDNESDAY. THIS HAS THE POTENTIAL TO BRING REDUCED CIGS/VSBY IN A PERIOD OF -SN AT RIC/SBY AND A MIX OF -RA/SN AT PHF/ORF/ECG...BEFORE POSSIBLY ENDING AS -SN AS FAR SE AS ECG. ADDITIONALLY...A GUSTY NW WIND IS EXPECTED...ESPECIALLY NEAR THE COAST. HIGH PRESSURE RETURNS WEDNESDAY AFTERNOON THROUGH FRIDAY. && .MARINE... WINDS STILL GUSTING TO ARND 25 KTS ACROSS NRN CSTL WTRS SO WILL KEEP CURRENT SCA HEADLINE UP EXPECTING THE WINDS WILL DIMINISH THRU THE EVE HOURS. RUC INDCTG A WEAK NRTH SURGE DOWN THE BAY THIS EVE BUT EXPECT WINDS TO REMAIN BLO 20 KTS. OTW...HIGH PRESSURE BUILDS ACROSS THE MARINE AREA TUE WITH A NORTH WIND BCMG SE AT SPEEDS BLO SCA LVLS. LOW PRESSURE EXITS MOVES OFF THE CAROLINA COAST ERLY WED. STRONG CAA BEHIND THIS SYSTM WILL LIKELY LEAD TO A PRD OF SCA`S FOR WINDS WED AFTRN AND EVE. FLOW THEN BECOMES SW THURSDAY AS WEAK HIGH PRESSURE MOVES OFF THE COAST. CANADIAN HIGH PRESSURE BUILDS SOUTH ACROSS THE AREA FRI. DATA SUGGESTS ANTHR CAA SURGE ERLY FRI. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST TUESDAY FOR ANZ650. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ652. && $$ SYNOPSIS...MAS NEAR TERM...MAS SHORT TERM...MAS LONG TERM...MPR AVIATION...AJZ/DAP MARINE...MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
636 PM EST TUE FEB 25 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 400 PM EST TUE FEB 25 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAMILIAR PATTERN FEATURING A DEEP UPR TROF OVER ERN NAMERICA DOWNSTREAM OF A RDG ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW IS STREAKING SEWD THRU ONTARIO JUST N OF LK SUP. COLD FNT ASSOCIATED WITH THIS DISTURBANCE HAS PASSED THRU THE CWA...AND H85 TEMPS AS LO AS -25C TO -28C ARE PUSHING INTO UPR MI IN THE LLVL W FLOW. ALTHOUGH THERE IS A GOOD DEAL OF ICE ON LK SUP...AREAS OF OPEN WATER OVER THE FAR WRN LK AND OVER THE SCENTRAL E OF THE KEWEENAW HAVE ALLOWED A GOOD DEAL OF LK CLD/SOME -SHSN TO FORM IN THE LLVL CAD. THE LK CLDS/SHSN APPEAR TO BE MOST WDSPRD OVER THE NE HALF OF THE AREA CLOSER TO THE SHRTWV PASSING THRU ONTARIO/ACCOMANPANYING DYNAMIC SUPPORT AND DEEPER MSTR. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LK EFFECT CLD/SHSN TRENDS AND TEMPS/NEED FOR WIND CHILL HEADLINES. LATE THIS AFTN/TNGT...AS THE H925 FLOW VEERS MORE TO THE NW THRU 00Z IN THE WAKE OF SHRTWV PASSING BY TO THE N...EXPECT LK EFFECT CLDS/SHSN TO SPREAD FARTHER TO THE S AND INLAND IN THE PRESENCE OF LENGTHENING DAYTIME HEATING DESPITE DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF THE SHRTWV PASSAGE. H85 THERMAL TROF WITH TEMPS DOWN TO -28/-29C IS FCST TO SHIFT THRU THE CWA BTWN 06Z-12Z AS THE LLVL FLOW BACKS TO THE W BTWN SFC HI PRES SINKING TOWARD THE MID MS RIVER VALLEY AND NEXT VIGOROUS SHRTWV DROPPING SEWD THRU SCENTRAL CANADA. WITH A PERIOD OF LARGER SCALE QVECTOR DVGC...EXPECT CLRG OVER THE INTERIOR...ALLOWING SFC TEMPS TO FALL WELL BLO ZERO AND INTO THE TEENS BLO ZERO AT SOME PLACES UNDER DRY AIRMASS WITH PWAT UNDER 0.10 INCH. ALTHOUGH THERE ARE QUESTIONS AS TO WHETHER SFC WINDS WL CONSISTENTLY SATISFY THE 10 MPH SPEED THRESHOLD FOR A WIND CHILL ADVY...PLAN TO ISSUE AN ADVY FOR THE COLDER NW HALF OF THE CWA WITH FAIRLY SHARP PRES GRADIENT/H925 WINDS IN THE 20-30KT RANGE UNDER H85 THERMAL TROF ENHANCING MIXING. LK EFFECT CLDS/-SHSN WL SHIFT FM THE NW WIND SN BELTS BACK INTO AREAS IMPACTED BY W WINDS LATE TNGT. ABSENCE OF DGZ WITHIN VERY COLD AIRMASS AND ICE COVER WL LIMIT SN ACCUMS. WED...AREA OF DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV/SFC LO DIGGING SEWD THRU NW ONTARIO WL OVERSPREAD UPR MI NW-SE BY EARLY AFTN. IN THE ABSENCE OF ANY SGNFT MSTR INFLOW...SUSPECT DRYNESS OF ANTECEDENT AIRMASS WL BE A SGNFT IMPEDIMENT TO OUTBRREAK OF PCPN. AS THE FLOW SHIFTS TO THE SW...THERE IS POTENTIAL FOR SOME LK MOISTENING/ENHANCEMENT OFF OF LK MI. BUT EXTENSIVE/GROWING ICE COVER OVER THE N HALF OF LK MI WL TEND TO MITIGATE THIS IMPACT. TENDED TOWARD THE HIER CHC/LIKELY POPS OVER THE NE HALF OF THE CWA TOWARD SHARPER ISENTROPIC ASCENT ON THE 270K SFC /NEAR H7/ AND ALSO LATE IN THE DAY OVER THE W WITH EXPECTED ARRIVAL OF ENHANCED LLVL CNVGC ASSOCIATED WITH COLD FNT ATTENDANT TO CLIPPER LO REACHING NE LK SUP BY 00Z THU. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 409 PM EST TUE FEB 25 2014 ANOTHER WAVE FROM THE TROUGH OVER EASTERN CANADA WILL BE QUICKLY DIVING SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION ON WEDNESDAY EVENING. A 1000MB LOW WILL BE DROPPING SOUTHEAST ACROSS NORTHEASTERN LAKE SUPERIOR AND THEN INTENSIFYING TO 995MB AS IT MOVES OVER THE GEORGIAN BAY BY 12Z THURSDAY. MODELS CONTINUE TO BE FAIRLY CONSISTENT WITH THE TRACK/INTENSITY/TIMING OF THE LOW...WHICH LENDS CONFIDENCE TO THE FORECAST...ESPECIALLY WITH THE WINDS. THE COMBINATION OF COLD AIR ADVECTION AND STRONG PRESSURE RISES (10MB/6HR) BEHIND THE LOW BETWEEN 06Z AND 15Z THURSDAY SHOULD LEAD TO A PERIOD OF GUSTY WINDS ACROSS MUCH OF UPPER MICHIGAN. THE WORST CONDITIONS WILL BE IN THE EXPOSED AREAS NEAR LAKE SUPERIOR FROM ONTONAGON EASTWARD. OVER THE KEWEENAW AND THEN AREAS FROM MARQUETTE EASTWARD...MODELS ARE SHOWING 925MB WINDS IN THE 35-45KT RANGE WITH THE HIGHEST VALUES FROM THE TIP OF THE KEWEENAW TO ALGER COUNTY. WITH THE PASSAGE OF THE COLD FRONT ON WEDNESDAY EVENING...THINK THERE WILL BE A PERIOD OF LIGHT SNOW BUT ACCUMULATIONS SHOULD BE LESS THAN .5IN IN MOST AREAS. ALTHOUGH THIS WON/T AMOUNT TO MUCH...IT WILL LEAD TO SOME BLOWING/DRIFTING SNOW. THE WORST CONDITIONS WILL AGAIN BE OVER THE KEWEENAW...WHICH ALREADY HAS LARGE MOUNDS/DRIFTS ON THE EDGES OF ROADWAYS THAT SHOULD EASILY REDEVELOP OVER THE ROADS WITH THE STRONG WINDS AND A LITTLE BIT OF SNOW. FARTHER EAST...THERE HAS BEEN SOME LIGHT LAKE EFFECT AND WITH ICE REDEVELOPING EAST OF THE KEWEENAW THERE SHOULD BE AN OPEN/FLAT AREA FOR THE SNOW TO MOVE ACROSS AND IMPACT ALGER COUNTY. WITH M-28 EXPOSED TO THE LAKE EAST AND BETTER ICE COVERAGE EAST OF SHOT POINT...THINK THERE WILL BE A GOOD POTENTIAL FOR BLOWING/DRIFTING SNOW CAUSING ISSUES ON THE ROAD THROUGH MUNISING. THE COLD AIR RECENTLY HAS LEAD TO ICE SPREADING OVER THE OPEN AREAS THE DEVELOPED A COUPLE DAYS AGO AND FORTUNATELY...THINK THIS WILL LIMIT THE AMOUNT OF LAKE EFFECT WITH THE NORTHWEST WINDS BEHIND THE LOW WED NIGHT INTO THURSDAY. ALSO...WITH A HIGH PRESSURE RIDGE QUICKLY MOVING IN TO THE U.P. FROM WEST TO EAST THURSDAY MORNING INTO THURSDAY AFTERNOON...IT SHOULD DO TWO THINGS. BRING DRIER AIR AND LIMIT THE ANY LAKE EFFECT INTENSITY AND ALSO LEAD TO QUICKLY WEAKENING WINDS. WITH THE PRECIPITATION...WIND...AND ALSO COLD TEMPERATURES...HEADLINES WILL LIKELY BE NEEDED OVER ALL OF UPPER MICHIGAN WEDNESDAY NIGHT INTO THURSDAY MORNING. WIND CHILL TEMPERATURES ARE CURRENTLY FORECAST IN THE -25 TO -40 DEGREE RANGE AND PUTS SOME NORTHERN AREAS ON BORDERLINE WIND CHILL WARNING CRITERIA. OTHERWISE...THINK THE ENTIRE U.P. WOULD NEED A WIND CHILL ADVISORY. SECOND...WITH THE REDUCED VISIBILITIES NEAR LAKE SUPERIOR FROM FALLING/BLOWING/DRIFTING SNOW...WILL LIKELY NEED AT LEAST A WINTER WEATHER ADVISORY FOR THE KEWEENAW PENINSULA AND ALGER COUNTY. THE WINDS AND VISIBILITIES WILL LIKELY PRODUCE BRIEF PERIODS OF BLIZZARD CONDITIONS IN THE KEWEENAW...BUT WITH THE MODELS ONLY SHOWING A PEAK PERIOD OF 6HRS OF THE WORST WINDS AND IT LARGELY BEING OVERNIGHT BEFORE QUICKLY DIMINISHING...FEEL IMPACT WON/T BE AS BAD AS PREVIOUS EVENT AND WON/T ISSUE A BLIZZARD WATCH. WINDS WILL LIKELY BE WORSE OVER ALGER COUNTY...BUT THERE IS MORE UNCERTAINTY WITH THE VISIBILITY ASPECT OF THE CRITERIA WITH THE LIMITED SNOWFALL SINCE THE RA/FZRA FROM LAST THURSDAY NIGHT (ALONG WITH GENERALLY NEW ICE UPSTREAM ON LAKE SUPERIOR AND LIMITED SNOW COVER). THUS...THINK ANY BLIZZARD CONDITIONS WOULD BE PATCHY AND WOULD SUPPORT MORE OF A WINTER WX ADVISORY. STILL LOOKS TO BE A RECORD BREAKING COLD DAY ON THURSDAY...WITH MODELS KEEPING MUCH OF THE AREA AROUND OR BELOW FREEZING FOR HIGHS. THAT SEEMS PRETTY REASONABLE WITH THE POCKET OF COLD 850MB TEMPS (-30C) DIRECTLY OVER THE AREA. THIS IS SIMILAR TO 850MB TEMPS FROM JANUARY 27TH AND HIGHS THAT DAY WERE IN THE SINGLE DIGITS BELOW ZERO OVER THE WEST AND AT OR JUST ABOVE FREEZING OVER THE EAST. AS MENTIONED YESTERDAY...ALL-TIME COLDEST HIGH TEMP RECORDS FOR FEB 27TH ARE GENERALLY IN THE MID SINGLE DIGITS ABOVE ZERO (WITH AT LEAST 6 DATING BACK BEFORE 1925). WITH COLD AIR IN PLACE AND A HIGH PRESSURE RIDGE PRODUCING LIGHT WINDS...EXPECT A VERY COLD NIGHT THURSDAY NIGHT AND WILL CONTINUE TO GO WITH THE LOW END OF GUIDANCE WHICH PLACES MUCH OF THE AREA BETWEEN -15 AND -30 BELOW. THIS ALSO HAS THE POTENTIAL FOR BEING RECORD LOWS AT SEVERAL LOCATIONS...AS LONG AS THE HIGH CLOUDS DON/T COME IN TOO QUICKLY FROM THE SOUTHWEST. THE HIGH PRESSURE RIDGE WILL SLIDE EAST ON FRIDAY AS ANOTHER SHORTWAVE ROUNDING THE EASTERN CANADA TROUGH APPROACHES. A WEAK INVERTED TROUGH (FROM A LOW IN THE SOUTHERN PLAINS) WILL SLIDE ACROSS THE AREA ON FRIDAY EVENING AND BRING THE POTENTIAL FOR LIGHT SNOW. IT DOES APPEAR TO BE OUT AHEAD OF THE MAIN FORCING FROM THE SHORTWAVE...SO UPPER LEVEL SUPPORT WILL BE LIMITED AND KEEP SNOW ACCUMULATIONS GENERALLY UNDER AN INCH. MODELS VARY ON HOW MUCH COLD AIR SPILLS IN BEHIND THIS TROUGH...BUT IT STILL LOOKS LIKE HIGHS ON SATURDAY WILL BE WELL BELOW NORMAL AND AT OR JUST ABOVE ZERO. THERE IS ALSO CONCERN FOR LAKE EFFECT SNOW WITH THE COLD AIR PRESENT...BUT WOULD EXPECT MUCH OF THE LAKE TO BE FROZEN OVER WITH THE COLD AIR OVER THE PREVIOUS COUPLE OF DAYS AND LIGHT WINDS THURSDAY NIGHT. THEREFORE...WILL KEEP POPS FOR SATURDAY IN THE SLIGHT CHANCE AND LOW END CHANCE CATEGORY FOR LOCATIONS NEAR LAKE SUPERIOR. HIGH PRESSURE BUILDING IN SATURDAY NIGHT AND REMAINING INTO SUNDAY SHOULD LEAD TO DRY CONDITIONS. FOR THE FIRST PART OF NEXT WEEK...THE UPPER TROUGH IN EASTERN CANADA DOES LOOK TO WEAKEN SOME AND BEGIN TO PULL NORTHEAST TOWARDS THE END OF THE WORK WEEK. OUR CLOSE PROXIMITY TO THIS TROUGH WILL KEEP THE MAIN STORM TRACK AND WARMER AIR WELL TO THE SOUTH OF THE AREA...BUT WE COULD STILL SEE WEAK WAVES SLIDING THROUGH. WOULD EXPECT LAKE SUPERIOR TO BE NEARLY ICE COVERED...SO WILL LIMIT ANY MENTION OF LAKE EFFECT POPS TO SLIGHT CHANCES AT MOST. AS FOR TEMPS...SHOULD SEE A SLOW/GRADUAL WARMING TREND THROUGH THE WORK WEEK...BUT TEMPS WILL STILL BE WELL BELOW NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 634 PM EST TUE FEB 25 2014 WINDS BEGINNING TO ABATE SLIGHTLY AT ALL THREE TAF SITES THIS EVENING. WINDS ARE TO GRADUALLY DIMINISH OVERNIGHT AS THEY BACK TO THE SSW/SW BY DAYBREAK...AND THEN WILL PICK UP AS THE MORNING PROGRESSES...WITH GUSTS TO 22-23KTS COMMON DURING THE LATE MORNING AND AFTERNOON HOURS. AT KCMX...LIFR/IFR VISIBILITIES DUE TO BRIEF LES SNOW BANDS AND GUSTY WINDS CHANNELED THROUGH THE TERRAIN THERE WILL EVENTUALLY IMPROVE AFTER 6Z AS WINDS DIMINISH AND DRIER AIR WORKING IN FROM THE WEST DIMINISHES LES. OTHERWISE...MVFR/VFR CONDITIONS PREVAIL AT KIWD AND KSAW WITH MVFR DEVELOPING AT KCMX BY 9Z...AND WILL CONTINUE THROUGH THE FORECAST. IFR VISIBILITY CONDITIONS MAY REDEVELOP AT KCMX WEDNESDAY AFTERNOON AS WINDS SHIFT BACK TO THE WEST AND PICK UP AND LES REDEVELOPS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 PM EST TUE FEB 25 2014 NW WINDS UP TO 25-30 KTS LATE TODAY UNDER SHARP PRES GRADIENT BETWEEN SFC HI OVER THE NCENTRAL PLAINS AND LO PRES IN EASTERN ONTARIO WILL SLOWLY BACK TO THE SW ON WED AS THE HI MOVES INTO THE MID MS RIVER VALLEY AND ANOTHER LO PRES SYSTEM DIVES SE INTO NW ONTARIO. THERE MAY BE SOME GALE FORCE GUSTS TO 35 KTS OVER THE W HALF OF THE LAKE WHERE FUNNELING OF THIS FLOW RESULTS IN SPEED ENHANCEMENT. ONCE THE LO SHIFTS TO THE E OF THE LAKE ON WED NIGHT AS THE PRES GRADIENT TIGHTENS AGAIN E OF HI PRES MOVING INTO THE NORTHERN PLAINS...N GALES UP TO 35-45 KTS WILL DEVELOP OVER THE ENTIRE LAKE. THE CLOSER APPROACH OF THE HI CENTER AND WEAKER PRES GRADIENT WILL CAUSE THE GALES TO DIMINISH W TO E ON THU. ISSUED A GALE WATCH FOR THE ENTIRE LAKE. EXPECT WINDS UNDER 25 KTS THE REST OF THE FORECAST PERIOD WITH A RELATIVELY WEAK PRES GRADIENT DOMINATING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WIND CHILL ADVISORY FROM MIDNIGHT EST /11 PM CST/ TONIGHT TO 10 AM EST /9 AM CST/ WEDNESDAY FOR MIZ001>005-009>011-084. LAKE SUPERIOR... GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON FOR LSZ243>245-248>251-264>267. GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR LSZ162-240>242-263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...RJT MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
407 PM EST MON FEB 24 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 357 PM EST MON FEB 24 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT...COLD NW FLOW DOMINATING THE GREAT LKS BTWN RDG ALONG THE W COAST AND CLOSED LO OVER QUEBEC/TROF IN ERN NAMERICA. COMBINATION OF SHRTWV EMBEDDED IN NW FLOW ALF...DEEPER MSTR SHOWN ON THE 12Z INL RAOB... H85 TEMPS IN THE -18C TO -21C RANGE AND SOME OPEN WATER ON LK SUP HAS RESULTED IN SOME GENERALLY LGT LES IN AREAS FAVORED BY THE LLVL WNW FLOW. OVER THE INTERIOR...SOME DIURNAL CU/SC HAVE DVLPD IN RATHER MOIST AIRMASS WITH INCRSG SUN ANGLE CAUSING SOME LLVL DESTABILIZATION. BTWN THE SHRTWV MOVING THRU THE UPR LKS EARLY THIS AFTN AND ANOTHER STRONGER DISTURBANCE STRETCHING FM NEAR LK WINNIPEG INTO THE NRN PLAINS/ACCOMPANYING -SN MOVING THRU THE DAKOTAS... SHRTWV RDG/AXIS OF DRIER MID LVL AIR IS BRINGING GENERALLY MOSUNNY WX TO MUCH OF MN EXCEPT THE ARROWHEAD. YET ANOTHER SHRTWV IS DROPPING SWD FM THE NW TERRITORIES OF CANADA INTO NRN SASKATCHEWAN/ MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LES TRENDS AND TEMPS ASSOCIATED WITH THE STEADY PARADE OF DISTURBANCES EMBEDDED IN NW FLOW ALF. TNGT...WITH APRCH AND PASSAGE OF SHRTWV RDG LATER THIS AFTN AND THIS EVNG/ACCOMPANYING DEEP LYR QVECTOR DVGC AND SUBSIDENCE...EXPECT LINGERING LES TO AT LEAST DIMINISH IN INTENSITY/COVERAGE FOR A TIME. BUT AS SHRTWV NOW MOVING INTO THE NRN PLAINS SHIFTS TO THE SE TNGT...AREA OF ACCOMPANYING DEEP LYR QVECTOR CNVGC/MORE MSTR AND SFC COLD FNT ARE FCST TO IMPACT THE AREA MAINLY AFT MIDNGT. ALTHOUGH ALL MODELS SHOW THE ACCOMPANYING SYNOPTIC SCALE PCPN PASSING TO THE S OF THE CWA CLOSER TO CORE OF UPR DVGC ON CYC SIDE OF H3 JET MAX... EXPECT AN INCRS IN LES COVERAGE NEAR LK SUP OVERNGT. TEMPS COULD FALL OFF QUICKLY THIS EVNG OVER AT LEAST THE INTERIOR NEAR THE WI BORDER AS AXIS OF DRIER AIR AT LEAST BRIEFLY MOVES OVHD BEFORE THICKER CLDS ASSOCIATED WITH DISTURBANCE NEAR LK WINNIPEG ARRIVE LATER. TUE...WHILE THERE MAY BE SOME MID LVL DRYING/SUBSIDENCE EARLY ON TUE WITH A PERIOD OF QVECTOR DVGC FOLLOWING THE DEPARTING DISTURBANCE... SHRTWV NOW DROPPING S INTO SASKATCHEWAN/MANITOBA IS FCST TO BRING A RETRUN OF MORE DYNAMIC SUPPORT/SOME DEEPER MSTR BY THE AFTN... ESPECIALLY OVER THE NE HALF OF THE CWA. SO EXPECT INCRSG LES POPS AGAIN IN THE WNW WIND SN BELTS NEAR THE LK. GIVEN H85 TEMPS FALLING AOB -25C BY LATE IN THE DAY CAUSING THE NEAR ELIMINATION OF THE DGZ AS WELL AS CONSIDERABLE ICE COVER OVER LK SUP...EXPECT SN AMOUNTS TO BE RELATIVELY LIGHT. TUE WL BE ANOTHER UNSEASONABLY COLD DAY. TENDED TOWARD THE LO END OF GUIDANCE FOR MAX TEMPS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 406 PM EST MON FEB 24 2014 THE FIRST IN A SERIES OF UPPER LEVEL DISTURBANCES THAT WILL BRING COLDER AIR TO THE AREA WILL BE SWEEPING ACROSS UPPER MICHIGAN TUESDAY AFTERNOON AND EARLY TUESDAY EVENING. THIS SHORTWAVE WILL USHER IN SLIGHTLY COLDER 850MB TEMPS ON TUESDAY NIGHT (-28C) AND WITH WINDS OUT OF THE NORTHWEST...WOULD EXPECT AT LEAST A BRIEF PERIOD OF LIGHT TO MODERATE LAKE EFFECT SNOW IN THE NORTHWEST WINDS SNOW BELTS DURING THE EVENING. BUT MODELS ARE SHOWING DRY AIR ABOVE 850MB MOVING IN QUICKLY AFTER 06Z WEDNESDAY...SO THAT SHOULD CUT OUT THE INTENSITY HEADING INTO THE OVERNIGHT HOURS. GETTING A GOOD HANDLE ON ICE COVER OVER THE WESTERN LAKE TODAY...WITH OPEN WATER GENERALLY NORTHWEST OF A LINE FROM THE APOSTLE ISLANDS TO TERRACE BAY ONTARIO. THAT GAP OF 30-40MI IS PLENTY TO SUPPORT LAKE EFFECT CLOUDS AND SNOW...WHICH HAS BEEN SEEN THIS MORNING OVER WESTERN UPPER MICHIGAN. THEREFORE...WILL CONTINUE TO SHOW LIKELY POPS IN THE NORTHWEST WIND AREAS OVER THE WEST IN THE EVENING AND DIMINISH SLIGHTLY OVERNIGHT WITH THE INCREASING DRY AIR AND BACKING WINDS ASSOCIATED WITH A WEAK HIGH PRESSURE RIDGE. THE EAST IS A LITTLE MORE COMPLICATED...SINCE THE ONLY POCKET OF OPEN WATER IS THE AREA TO THE EAST OF THE KEWEENAW PENINSULA AND SOUTH TO MARQUETTE. WITH THE NORTHWEST WINDS...THAT WOULD SUPPORT THE HIGHEST POPS/AMOUNTS OVER ALGER COUNTY AND THINK FARTHER EAST INTO LUCE COUNTY (EVEN THE EASTERN THIRD OF ALGER COUNTY) WOULD SEE LESS ACCUMULATION AND MORE SCATTERED SNOW SHOWERS WITH THE AMOUNT OF ICE THE BANDS ORIGINATING NORTHEAST OF ISLE ROYALE WOULD HAVE TO PASS OVER. THE WEAK HIGH PRESSURE WILL SLIDE ACROSS THE U.P. LATE TUESDAY NIGHT AND WEDNESDAY MORNING...AS THE NEXT SHORTWAVE AND LOW PRESSURE SYSTEM DIVE SOUTHEAST OUT OF WESTERN ONTARIO WEDNESDAY AFTERNOON AND ACROSS LAKE SUPERIOR AT 998MB ON WEDNESDAY EVENING. THE BEST SNOW ASSOCIATED WITH THIS LOW AND SHORTWAVE WILL LIKELY BE NEAR THE SURFACE LOW WITH THE LOWER LEVEL DRY AIR BEING PULL NORTHEAST ACROSS UPPER MICHIGAN. ANY SYNOPTIC SNOW SHOULD BE LIGHT AND ONLY CREATE A LIGHT DUSTING...MAINLY NEAR LAKE SUPERIOR. BUT BEHIND THE LOW...EXPECT ANOTHER OPPORTUNITY FOR LAKE EFFECT SNOW IN NORTHWEST TO NORTH-NORTHWEST WIND AREAS. THE 925MB WINDS WILL BE FAIRLY STRONG (35KTS) BEHIND THE FRONT AND WILL LIKELY LIMIT THE RESIDENCE TIME OVER THE 30-40MI STRETCH OF OPEN WATER. WOULD EXPECT THIS TO LIMIT SNOWFALL AMOUNTS EVEN THOUGH DELTA-T VALUES ARE NEARING 30-32 AND INVERSION HEIGHTS ARE BETWEEN 10-14KFT. ALTHOUGH SNOW AMOUNTS MAY NOT BE TOO SIGNIFICANT...THINK THE PERIOD OF VERY GUSTY NORTHWEST WINDS ON THE BACK SIDE OF THE LOW (GUSTS NEAR LAKE SUPERIOR OF 30-40KTS NEAR LAKE SUPERIOR FROM ONTONAGON TO WHITEFISH POINT) WILL CREATE A SIGNIFICANT CONCERN FOR WIDESPREAD BLOWING AND DRIFTING SNOW. HAVE TRENDED WINDS UP 5-10KTS FOR THIS PERIOD WITH THE CONSISTENCY IN THE MODELS ON THIS WINDY IDEA. WILL ALSO ADD A MENTION OF THE POTENTIAL FOR CONSIDERABLE BLOWING AND DRIFTING SNOW NEAR LAKE SUPERIOR IN THE HWO THAT WILL DEVELOP WEDNESDAY NIGHT AND CONTINUE INTO THURSDAY MORNING. ADD FINE FLAKE SNOW FALLING WITH THE BLOWING SNOW SHOULD EASILY CREATE VISIBILITIES OF 1/2MI OR LESS IN THE KEWEENAW. THE GUSTY WINDS WILL COMBINE WITH TEMPERATURES BELOW ZERO ON THURSDAY MORNING TO ALSO CREATE A CONCERN FOR WIND CHILL HEADLINES FOR A GOOD PORTION OF UPPER MICHIGAN. CURRENT FORECAST HAS WIND CHILL VALUES OF -25 TO -35 DEGREES AND WITH THE POTENTIAL FOR BLOWING SNOW IT COULD EVENTUALLY BE TIED TOGETHER WITH A WINTER WX ADVISORY. ONCE AGAIN...A HIGH PRESSURE RIDGE (FROM A HIGH MOVING INTO THE UPPER MISSISSIPPI VALLEY) WILL QUICKLY MOVE OVER UPPER MICHIGAN ON THURSDAY AFTERNOON INTO THURSDAY NIGHT. THIS SHOULD RAPIDLY DIMINISH WINDS OVER THE AREA DURING THE AFTERNOON. MODELS CONTINUE TO SHOW HIGHS ONLY REACHING AROUND 0 DEGREES ON THURSDAY...WHICH WOULD PUT SEVERAL COLD HIGH TEMPERATURE RECORDS IN JEOPARDY SINCE MOST ARE IN THE MID SINGLE DIGITS ABOVE ZERO. FOR THE LONG PERIOD OF RECORD SITES...MOST OF THOSE RECORDS DATE BACK TO THE LATE 1800S AND EARLY 1900S. WOULD EXPECT SKIES TO CLEAR OUT AWAY FROM ANY LAKE EFFECT NEAR LAKE SUPERIOR THURSDAY AFTERNOON AND CONTINUE INTO THURSDAY NIGHT. THINK THIS WILL LEAD TO A VERY COLD NIGHT ACROSS THE AREA AND WILL CONTINUE TO SHOW LOWS IN THE 10S TO MID 20S BELOW ZERO (COLDEST INTERIOR COLD SPOTS). ANOTHER SHORTWAVE WILL ROUND THE EASTERN CANADA UPPER TROUGH ON FRIDAY AND DIVE SOUTHEAST ACROSS UPPER MICHIGAN FRIDAY NIGHT. THE COLD AIR ASSOCIATED WITH THIS WAVE WILL LEAD TO ANOTHER DAY OF HIGHS ABOUT 30 DEGREES BELOW NORMAL ON SATURDAY. LAKE EFFECT POTENTIAL CONTINUES FRIDAY NIGHT INTO SATURDAY...BUT WORRIED THAT THE VERY COLD TEMPS AND LIGHT WINDS ON THURSDAY NIGHT INTO FRIDAY WILL LEAD TO A FAST ICE UP OF THE OPEN AREAS AND CUT OFF LAKE EFFECT. WILL GO WITH SLIGHT AND LOW CHANCE POPS AT THIS POINT DUE TO THE UNCERTAINTY. EXTENDED MODELS ARE SHOWING A TREND TOWARDS MORE ZONAL FLOW AND GRADUALLY WARMING TEMPERATURES SUNDAY AND HEADING INTO NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1222 PM EST MON FEB 24 2014 AS A WEAK SFC HI PRES RDG/DRIER AIR MOVE IN LATE THIS AFTN/EVNG... EXPECT IMPROVING CONDITIONS AT ALL 3 TAF SITES...TO MVFR AT IWD/CMX AND VFR AT SAW. BUT ANOTHER DISTURBANCE WL BRING AN UPTICK IN LK EFFECT SHSN AND BLSN AT IWD/CMX LATER TNGT...WITH VSBYS FALLING INTO THE IFR RANGE. DOWNSLOPE WIND COMPONENT INTO SAW SHOULD MAINTAIN VFR WX THERE. ALTHOUGH SOME DRYING IN THE WAKE OF THIS DISTURBANCE MIGHT CAUSE AN IMPROVEMENT TO MVFR AT IWD ON TUE...DAYTIME HEATING WL LIKELY RESULT IN AN MVFR CIG AT SAW WITH THE ARRIVAL OF MORE UNSTABLE AIR. IFR CONDITIONS ARE LIKELY TO PLAGUE THE EXPOSED CMX LOCATION THRU 18Z TUE UNDER THIS AXIS OF COLDER AIR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 PM EST MON FEB 24 2014 WEST TO NORTHWEST WINDS OF 15-25KTS WILL CONTINUE TONIGHT THROUGH TUESDAY NIGHT...BUT THEN BACK ON WEDNESDAY MORNING AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM. A TIGHTENING GRADIENT AHEAD OF THAT LOW COULD LEAD TO A FEW GALE FORCE GUSTS TO 35KTS AROUND MID-DAY WEDNESDAY. THEN AS THE LOW DROPS SOUTHEAST ACROSS EASTERN LAKE SUPERIOR ON WEDNESDAY EVENING...EXPECT A RAPID SWITCH AND INCREASE IN THE WINDS FROM THE NORTHWEST AND CURRENT THOUGHT IS THAT MUCH OF THE LAKE WILL SEE GALE FORCE GUSTS TO 35-40KTS. A HIGH PRESSURE RIDGE WILL QUICKLY MOVE OVER THE AREA THURSDAY AFTERNOON/NIGHT AND WEAKEN THE WINDS. ANOTHER TROUGH MOVING THROUGH ON FRIDAY NIGHT WILL INCREASE WINDS BACK TO 15-25KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
357 PM EST MON FEB 24 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 357 PM EST MON FEB 24 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT...COLD NW FLOW DOMINATING THE GREAT LKS BTWN RDG ALONG THE W COAST AND CLOSED LO OVER QUEBEC/TROF IN ERN NAMERICA. COMBINATION OF SHRTWV EMBEDDED IN NW FLOW ALF...DEEPER MSTR SHOWN ON THE 12Z INL RAOB... H85 TEMPS IN THE -18C TO -21C RANGE AND SOME OPEN WATER ON LK SUP HAS RESULTED IN SOME GENERALLY LGT LES IN AREAS FAVORED BY THE LLVL WNW FLOW. OVER THE INTERIOR...SOME DIURNAL CU/SC HAVE DVLPD IN RATHER MOIST AIRMASS WITH INCRSG SUN ANGLE CAUSING SOME LLVL DESTABILIZATION. BTWN THE SHRTWV MOVING THRU THE UPR LKS EARLY THIS AFTN AND ANOTHER STRONGER DISTURBANCE STRETCHING FM NEAR LK WINNIPEG INTO THE NRN PLAINS/ACCOMPANYING -SN MOVING THRU THE DAKOTAS... SHRTWV RDG/AXIS OF DRIER MID LVL AIR IS BRINGING GENERALLY MOSUNNY WX TO MUCH OF MN EXCEPT THE ARROWHEAD. YET ANOTHER SHRTWV IS DROPPING SWD FM THE NW TERRITORIES OF CANADA INTO NRN SASKATCHEWAN/ MANITOBA. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LES TRENDS AND TEMPS ASSOCIATED WITH THE STEADY PARADE OF DISTURBANCES EMBEDDED IN NW FLOW ALF. TNGT...WITH APRCH AND PASSAGE OF SHRTWV RDG LATER THIS AFTN AND THIS EVNG/ACCOMPANYING DEEP LYR QVECTOR DVGC AND SUBSIDENCE...EXPECT LINGERING LES TO AT LEAST DIMINISH IN INTENSITY/COVERAGE FOR A TIME. BUT AS SHRTWV NOW MOVING INTO THE NRN PLAINS SHIFTS TO THE SE TNGT...AREA OF ACCOMPANYING DEEP LYR QVECTOR CNVGC/MORE MSTR AND SFC COLD FNT ARE FCST TO IMPACT THE AREA MAINLY AFT MIDNGT. ALTHOUGH ALL MODELS SHOW THE ACCOMPANYING SYNOPTIC SCALE PCPN PASSING TO THE S OF THE CWA CLOSER TO CORE OF UPR DVGC ON CYC SIDE OF H3 JET MAX... EXPECT AN INCRS IN LES COVERAGE NEAR LK SUP OVERNGT. TEMPS COULD FALL OFF QUICKLY THIS EVNG OVER AT LEAST THE INTERIOR NEAR THE WI BORDER AS AXIS OF DRIER AIR AT LEAST BRIEFLY MOVES OVHD BEFORE THICKER CLDS ASSOCIATED WITH DISTURBANCE NEAR LK WINNIPEG ARRIVE LATER. TUE...WHILE THERE MAY BE SOME MID LVL DRYING/SUBSIDENCE EARLY ON TUE WITH A PERIOD OF QVECTOR DVGC FOLLOWING THE DEPARTING DISTURBANCE... SHRTWV NOW DROPPING S INTO SASKATCHEWAN/MANITOBA IS FCST TO BRING A RETRUN OF MORE DYNAMIC SUPPORT/SOME DEEPER MSTR BY THE AFTN... ESPECIALLY OVER THE NE HALF OF THE CWA. SO EXPECT INCRSG LES POPS AGAIN IN THE WNW WIND SN BELTS NEAR THE LK. GIVEN H85 TEMPS FALLING AOB -25C BY LATE IN THE DAY CAUSING THE NEAR ELIMINATION OF THE DGZ AS WELL AS CONSIDERABLE ICE COVER OVER LK SUP...EXPECT SN AMOUNTS TO BE RELATIVELY LIGHT. TUE WL BE ANOTHER UNSEASONABLY COLD DAY. TENDED TOWARD THE LO END OF GUIDANCE FOR MAX TEMPS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 347 AM EST MON FEB 24 2014 THE 500MB TROUGH WILL LINGER ACROSS E CANADA/E U.S. THROUGH THE PERIOD. STARTING TUESDAY THE MAIN 500MB LOW SET UP ACROSS HUDSON BAY WILL EXTEND A LARGE TROUGH FROM SASKATCHEWAN THROUGH THE CENTRAL PLAINS AND E U.S. EXPECT THE APEX OF THE 500MB TROUGH TO BE ACROSS THE CWA AT 00Z WEDNESDAY AS THE MAIN LOW SLOWLY SINKS S INTO ONTARIO AND THE ONTARIO/QUEBEC BORDER THURSDAY. THE CLOSEST THE 500MB LOW WILL BE TO THE CWA WILL BE WEDNESDAY NIGHT. 500MB TEMPS OF -50C NEAR THE CENTER OF THE LOW WILL REMAIN TO OUR NE. WHILE SNOW SHOWERS WILL BE POSSIBLE...MAINLY ALONG LAKE SUPERIOR THROUGH THURSDAY...MUCH OF THE DISCUSSION BELOW WILL FOCUS ON THE EXTREMELY COLD TEMPERATURES. COOL NW FLOW WILL BE THE RULE BEHIND THE SFC LOW SWEEPING FROM NW/CENTRAL ONTARIO AT 18Z WEDNESDAY TO CENTRAL AND NE LAKE SUPERIOR BY 00Z THURSDAY AND SE QUEBEC EARLY THURSDAY MORNING. THIS WILL ALLOW THE ARCTIC AIRMASS TO SINK IN AND LINGER THROUGH THE 1ST HALF OF THE UPCOMING WEEKEND. 850MB TEMPS DURING THIS TIME WILL RANGE FROM -28 TO -32C. SFC TEMPS WILL GREATLY DEPEND ON CLOUD COVER AND OPEN WATER ACROSS LAKE SUPERIOR. COLDEST SFC TEMPS LOOK TO OCCUR FRIDAY MORNING. 2M TEMPS OFF THE 24/00Z GFS SHOW MIN TEMPS OVER N MN AND CENTRAL WI OF -20 TO -30F /BUT ONLY -5 TO -15F ACROSS UPPER MI/. WITH HIGH PRESSURE NEARLY OVERHEAD AND WINDS UNDER 5KTS...CONTINUED TO GO ON THE LOW END OF GUIDANCE. WIND CHILL VALUES WILL NOT BE MUCH LOWER THAN THE ACTUAL TEMPS THANKS TO THE LIGHT WINDS. LOW WIND CHILLS ARE INEVITABLE EACH OVERNIGHT/MORNING THROUGH THURSDAY MORNING. THE LOWEST WIND CHILLS WILL BE LIKELY THURSDAY MORNING AS UPPER MI RESIDES BETWEEN THE DEEPENED LOW LOVER SE ONTARIO AND LARGE STRONG HIGH STRETCHING FROM MN TO NW CANADA. A NW PUFF OF 8-10KTS /STRONGER FROM THE KEWEENAW PENINSULA ALONG THE LAKE SUPERIOR SHORELINES/ WILL HELP WIND CHILLS FALL TO -20 TO NEARLY -35F OVER MUCH OF W AND CENTRAL UPPER MI...LOWEST ALONG THE WI BORDER. GIVEN ALL THE DISCUSSION ABOUT TEMPERATURES...BELIEVE IT OR NOT...NORMAL HIGH TEMPS THIS TIME OF YEAR ARE IN THE UPPER 20S AND LOW 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1222 PM EST MON FEB 24 2014 AS A WEAK SFC HI PRES RDG/DRIER AIR MOVE IN LATE THIS AFTN/EVNG... EXPECT IMPROVING CONDITIONS AT ALL 3 TAF SITES...TO MVFR AT IWD/CMX AND VFR AT SAW. BUT ANOTHER DISTURBANCE WL BRING AN UPTICK IN LK EFFECT SHSN AND BLSN AT IWD/CMX LATER TNGT...WITH VSBYS FALLING INTO THE IFR RANGE. DOWNSLOPE WIND COMPONENT INTO SAW SHOULD MAINTAIN VFR WX THERE. ALTHOUGH SOME DRYING IN THE WAKE OF THIS DISTURBANCE MIGHT CAUSE AN IMPROVEMENT TO MVFR AT IWD ON TUE...DAYTIME HEATING WL LIKELY RESULT IN AN MVFR CIG AT SAW WITH THE ARRIVAL OF MORE UNSTABLE AIR. IFR CONDITIONS ARE LIKELY TO PLAGUE THE EXPOSED CMX LOCATION THRU 18Z TUE UNDER THIS AXIS OF COLDER AIR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 323 AM EST MON FEB 24 2014 NO GALES ARE EXPECTED...BUT SOME HEAVY FREEZING SPRAY IS POSSIBLE IN ANY OPEN WATERS ON WEDNESDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...KC MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1203 AM EST MON FEB 24 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 435 PM EST SUN FEB 23 2014 THE UPPER GREAT LAKES REGION IS UNDER THE INFLUENCE OF A UPPER LOW SPINNING OVER EASTERN ONTARIO AT THIS TIME. THIS UPPER LOW HAS BEEN ROTATING MID LEVEL MOISTURE SOUTHEAST ACROSS THE REGION TODAY AS SEEN IN WATER VAPOR IMAGERY AND REPRESENTED ON THE 12Z KINL SOUNDING. WITH THE OPEN WATER OVER PORTIONS OF WESTERN LAKE SUPERIOR...MOISTURE FROM THE UPPER LOW...AND RAP ANALYZED 850MB TEMPS AROUND -22C...HAVE BEEN SEEING LAKE CLOUDS AND LIGHT SNOW SHOWERS ON WEBCAMS AND SATELLITE OVER NORTHERN ONTONAGON...HOUGHTON AND KEWEENAW COUNTIES. THERE WAS ONE STRONGER BAND THAT STRETCHED FROM NORTHERN HOUGHTON COUNTY TO JUST NORTH OF GRAND MARAIS. WHERE THE RADAR CAN SAMPLE IT IT WAS INDICATING SNOWFALL RATES AROUND 0.5-1 INCH AN HOUR SOUTH EAST OF STANNARD ROCK WHERE IT HAS BEEN AIDED BY ANOTHER AREA OF OPEN WATER. AS WINDS HAVE BEEN SLOWLY SHIFTING TO THE NORTHWEST...THIS BAND HAS BEEN SHIFTING SOUTH THROUGH THE DAY...BUT DID GET A REPORT FROM WHITEFISH POINT OF AN ESTIMATED 6-8 INCHES OF SNOW. WOULD EXPECT AMOUNTS THAT HIGH IN NORTHERN LUCE COUNTY WITH THE MOVEMENT BUT THINK AMOUNTS IN THE 1-3 INCH RANGE ARE REASONABLE SINCE THIS MORNING. AS THE UPPER TROUGH AND SURFACE LOW SHIFT EAST TONIGHT...IT WILL SWEEP A WEAK SHORTWAVE AND SFC-850MB TROUGH SOUTHEAST ACROSS LAKE SUPERIOR. THESE TROUGHS WILL ACT TO PROVIDE MORE LOW LEVEL MOISTURE OVER THE REGION TONIGHT INTO MONDAY MORNING AND TURN THE LOW LEVEL WINDS TO THE NORTHWEST. 850MB TEMPS OF -23C WILL LEAD TO PLENTY OF OVER THE LAKE INSTABILITY WHERE THERE IS OPEN WATER (INVERSION HEIGHTS TO 6-7KFT). THERE IS A LITTLE BIT OF AN UNCERTAINTY ON THE ICE COVERAGE...BUT BASED OFF YESTERDAY/S MODIS IMAGE AND LOCATION OF LAKE CLOUDS TODAY...IT APPEARS THERE IS DECENT OPEN WATER FROM TWO HARBORS MINNESOTA TO ISLE ROYALE...THEN EAST-NORTHEAST OF ISLE ROYALE TO NORTHERN LAKE SUPERIOR AND ALSO TO THE EAST OF THE KEWEENAW AND TOWARDS MARQUETTE. WHERE ICE CAN BE MADE OUT...THERE HAS BEEN DECENT MOVEMENT WITH THE WEST-NORTHWEST WINDS OF 20-30KTS. WITH WEAKENING WINDS INCREASING THE RESIDENCE TIME OVER THE 20-30MI AREA OF OPEN WATER OVER THE WEST TONIGHT...THINK THAT WILL BE ENOUGH FOR LIGHT AND OCCASIONALLY MODERATE LAKE EFFECT SNOWS TO OCCUR FROM CALUMET SOUTHWEST TO IRONWOOD AND WILL CONTINUE TO SHOW LIKELY AND LOW DEFINITE POPS FOR THOSE AREAS TONIGHT. NORTH OF CALUMET IS A LITTLE UNCERTAIN ONCE WINDS TURN TO THE NORTHWEST DUE TO MORE ICE BETWEEN ISLE ROYALE AND THUNDER BAY AND SMALLER GAPS IN THE FIRST 10-15MI SOUTHEAST FROM ISLE ROYALE. THEREFORE...WILL HAVE THE POPS LOWER INTO THE LOW END LIKELY CATEGORY ONCE THE WINDS TURN TO THE NORTHWEST. OVERALL...SNOWFALL AMOUNTS SHOULD BE LIGHT AND IN THE 1-4 INCH RANGE. GUSTY THIS EVENING (TO 35MPH)...BUT WITH THE LOW WEAKENING AND SHIFTING EAST TONIGHT...SHOULD SEE A GRADUAL DIMINISHING TREND TO THE WINDS. THIS WILL LEADING TO IMPROVING VISIBILITIES FROM THE BLOWING SNOW OVER THE KEWEENAW PENINSULA. SINCE WE ARE STILL GETTING REPORTS FROM OBS/WEBCAMS/SPOTTERS OF VISIBILITIES BELOW 1/2MI AT TIMES...DECIDED TO EXTEND THE ADVISORY UNTIL MIDNIGHT. THIS WILL COVER THE EVENING TRAVEL PERIOD BEFORE THE WINDS DIMINISH OVERNIGHT. FARTHER EAST...THE MAIN AREA OF CONCERN WILL BE OVER NORTHERN LUCE AND THEN TRANSITIONING INTO ALGER COUNTY DUE TO THE FAVORABLE FETCH ACROSS THE OPEN WATER THAT LIKELY COVERS A DECENT PORTION OF LSZ265. WITH NORTHWEST WINDS AND PROBABLY SOME LAND BREEZE INFLUENCE...WOULD THINK THERE WOULD BE SOME ENHANCED LAKE EFFECT BAND AFFECTING THE COUNTY AND GRADUALLY TRANSITIONED THE BAND SOUTHWEST THIS EVENING TO AROUND AND JUST EAST OF MUNISING AREA OVERNIGHT. WITH A POTENTIAL FETCH OF 80MI AND SOME UPSTREAM MOISTENING OVER THE WESTERN LAKE...WOULDN/T BE SURPRISED IF THERE ARE SOME LOCALIZED 4 INCH AMOUNTS ESPECIALLY IF THE BAND STALLS IN AN AREA FOR A FEW HOURS. EAST OF THERE...THE AMOUNT OF ICE COVERAGE WILL LIKELY LIMIT AMOUNTS AND ONLY HAVE VALUES IN THE 1 TO MAYBE 2 INCH RANGE. WILL START TO SEE THE AFFECT OF RIDGING UPSTREAM THROUGH THE DAY TOMORROW AS THE UPPER LOW SHIFTS EAST. THIS WILL LEAD TO INCREASING 850MB TEMPERATURES (ALONG WITH SOME DRYING AND BACKING WINDS) FROM WEST TO EAST...ESPECIALLY IN THE AFTERNOON. THUS...WILL FOLLOW THAT TREND FOR POPS AND SNOWFALL AMOUNTS THROUGH THE DAY. HIGHS TOMORROW WILL BE IN THE LOW-MID TEENS OVER MUCH OF THE AREA. THIS LOOKS TO BE THE WARMEST HIGHS FOR THE REST OF THE WORK WEEK. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 435 PM EST SUN FEB 23 2014 THE CWA WILL BE DOMINATED BY LOW WIND CHILLS...AND LIGHT TO MODERATE LES FOR AREAS DOWNWIND OF W TO NW FLOW OVER GAPS IN THE CONSIDERABLE LAKE ICE COVER. MON NIGHT...THE STRONGEST 850-500 MB QVECTOR CONV AND LOWER LEVEL WAA/ISENTROPIC LIFT ASSOCIATED WITH THE FIRST IN A SERIES OF SHORTWAVE TROUGHS IS EXPECTED TO REMAIN WELL TO THE SOUTH THROUGH IA INTO SRN WI AND NRN IL. WRLY FLOW LES BANDS WILL SHIFT SLIGHTLY AS WINDS VEER TO WNW BEHIND A WEAK SFC TROUGH. WITH CONTINUED UNCERTAINTY ON THE EXTENT OF OPEN WATER AND INVERSION HEIGHTS ONLY AROUND 5K FT...MENTIONED LIKELY POPS BUT WITH FCST SNOWFALL AMOUNTS ONLY OF AROUND AN INCH OR TWO. TUE INTO TUE NIGHT...THE MODELS SUGGEST ANOTHER SHRTWV WITH AN ARCTIC FRONT BRINGING IN EVEN COLDER AIR WILL MOVE THROUGH BY LATE TUE INTO TUE NIGHT. WINDS WILL VEER TO THE NW PUSHING THE LIGHT LES OVER A GRATER PORTION OF THE ERN CWA. WITH MIN TEMPS DROPPING INTO THE -4F TO -14F RANGE...WIND CHILLS SHOULD ALSO FALL INTO THE -20 TO -30 RANGE. WED-FRI...A STRONGER SHRTWV WILL MOVE THROUGH THE NRN LAKES AS THE POLAR TROUGH MOVES INTO NRN ONTARIO. WINDS ARE EXPECTED TO VEER TO THE NW TO NNW BEHIND THIS FEATURE AS 850 MB TEMPS DROP TO AROUND -31C THU. WITH THE STRONGER NW WINDS...THE LOWEST WIND CHILLS ARE EXPECTED THU MORNING INTO THE -25 TO -35 RANGE EVEN THOUGH THERE MAY SOME MODIFICATION OVER THE MOSTLY FROZEN LAKE. WITH LIGHTER WINDS AND FEW CLOUDS BY FRI AS THE ARCTIC HIGH SETTLES OVER THE AREA...TEMPS SHOULD DROP AT LEAST INTO THE -15 TO -25 RANGE OVER MUCH OF THE CWA...WITH SOME -30S EVEN POSSIBLE FOR TRADITIONAL COLD SPOTS. SAT-SUN...THERE IS GREATER UNCERTAINTY WITH ANY INDIVIDUAL SHRTWVS BUT WITH THE POLAR TROUGH LINGERING NEAR JAMES BAY...ANOTHER BOUT OF LOWER 850 MB TEMPS AND HIGHER WINDS MAY MOVE IN BY SAT WITH DIMINISHING WINDS AND CONTINUED COLD ON SUN WITH THE ARCTIC RIDGE DOMINATING THE NRN LAKES. BY THE WEEKEND...THE ICE COVER IS LIKELY TO SOLIDIFY...REDUCING LES CHANCES/AMOUNTS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1203 AM EST MON FEB 24 2014 WITH LIGHTER NW WINDS AND LESS BLSN...EXPECT MVFR CONDITIONS TO PREVAIL THRU THE FCST PERIOD AT KCMX. HOWEVER...WITH OCNL LAKE EFFECT -SHSN...THERE WILL LIKELY BE SOME PERIODS OF IFR CONDITIONS AS WELL. DISTURBANCE CROSSING THE AREA THIS EVENING COULD BRING MORE SUSTAINED IFR VIS. AT KIWD...LAKE EFFECT -SHSN AND IFR CONDITIONS HAVE DEVELOPED AS EXPECTED DUE TO WINDS VEERING MORE TO THE NW. IFR CONDITIONS SHOULD PREVAIL OVERNIGHT INTO THE EARLY MORNING. THEREAFTER...THERE SHOULD BE SOME IMPROVEMENT BACK TO MVFR BY LATE MORNING AS DEEPER MOISTURE EXITS. CONDITIONS MAY IMPROVE TO VFR AT TIMES DURING THE AFTN/EVENING. AT KSAW...DOWNSLOPE NATURE OF THE W TO NW FLOW HAS RESULTED IN CONDITIONS REMAINING VFR. HOWEVER...WITH INCREASE IN LOW-LEVEL MOISTURE...HIGH MVFR CIGS SHOULD STILL DEVELOP OVERNIGHT...THEN LIFT TO VFR THIS AFTN. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 435 PM EST SUN FEB 23 2014 THE WEAKENING LOW NEAR HUDSON BAY WILL COMBINE WITH A HIGH PRESSURE RIDGE MOVING THROUGH THE NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO LEAD TO GRADUALLY DECREASING WEST TO NORTHWEST WINDS OVER LAKE SUPERIOR TONIGHT THROUGH MONDAY NIGHT. HAVE BEEN SEEING THE GALES PERSISTING OVER THE EASTERN PART OF LAKE SUPERIOR ON THE STANNARD ROCK AND GRANITE ISLAND OBS THIS AFTERNOON...BUT WITH UPSTREAM OBS GENERALLY IN THE 30KT RANGE...WOULD EXPECT THE EASTERN SITES TO COME DOWN SHORTLY. THUS...WILL ALLOW THE GALE WARNING OVER THE EASTERN LAKE TO EXPIRE AT 00Z AND HAVE ALREADY CANCELLED THE WESTERN LAKE. EVEN WITH THIS DIMINISHMENT...THERE WILL LIKELY BE ENOUGH OF A GRADIENT TO KEEP WINDS IN THE 15 TO 30KT RANGE FOR MUCH OF THE FORECAST PERIOD. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...JLB AVIATION...ROLFSON MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
515 PM CST TUE FEB 25 2014 .UPDATE...QUICK UPDATE HERE TO TOUCH ON SOME RECENT TRENDS FOR THIS EVENING/OVERNIGHT. THE MAIN CONCERN WILL BE FOR SOME DECENT RAINFALL AMOUNTS ACROSS THE SOUTHERN PARTS OF THE CWA. LATEST HI-RES NCEP MODELS...LOCAL WRF AND HRRR INDICATE LOCATIONS ALONG AND SOUTH OF THE HWY 84 CORRIDOR COULD SEE 1-2 INCHES. IF MULTIPLE STORMS OCCUR (WHICH IS A POSSIBILITY) THEN SOME LOCALIZED AREAS COULD SEE HIGHER TOTALS WHICH COULD CAUSE SOME FLOODING ISSUES. WE WILL CONTINUE TO MONITOR THIS AND ADD HAZARDS TO THE HWO IF CONFIDENCE INCREASES IN THE FLOODING POTENTIAL. ADDITIONALLY...DURING THE INITIAL ONSET OF CONVECTION ACROSS THE SW...THERE LOOKS TO EXIST JUST ENOUGH ELEVATED INSTABILITY (FROM STEEP LAPSE RATES) TO SUPPORT SOME SMALL HAIL OF PENNY SIZED OR LESS. THIS WOULD ONLY BE POSSIBLE ACROSS THE FAR SW ZONES AND BETWEEN 6-8 PM. /CME/ && .PREV DISCUSSION... /ISSUED 353 PM CST TUE FEB 25 2014/ SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...RAIN WILL BE SPREADING ACROSS THE REGION TONIGHT AS A SHORTWAVE AND ASSOCIATED COLD FRONT MOVES THROUGH THE REGION. LATEST MODELS INDICATE THAT SOME SLEET COULD MIX IN LATER TONIGHT ALONG AND NORTH OF THE HIGHWAY 82 CORRIDOR AS COLDER AIR MOVES IN BEHIND THE FRONT. TEMPERATURES SHOULD REMAIN ABOVE FREEZING SO NO WINTRY MIX ACCUMULATION IS EXPECTED. GUSTY NORTH WINDS WILL DEVELOP TONIGHT INTO WEDNESDAY MORNING BEHIND THE FRONT WHICH COULD RESULT IN WIND CHILLS FALLING INTO THE LOWER 20S AT LOCATIONS ALONG THE HIGHWAY 82 CORRIDOR. RAIN CHANCES WILL GRADUALLY BE ENDING FROM WEST TO EAST WEDNESDAY AS DRIER AIR SURGES INTO THE REGION AND STRONG HIGH PRESSURE BUILDS SOUTH. SKIES WILL GRADUALLY CLEAR FROM THE NORTH WEDNESDAY. HIGHS WEDNESDAY AFTERNOON WILL NOT CLIMB OUT OF THE 30S AT SOME LOCATIONS IN THE NORTH. THE SHORTWAVE AXIS WILL SHIFT EAST OF OUR CWA BY WEDNESDAY NIGHT BUT SURFACE RIDGING WILL SHIFT OVER OUR CWA. THIS WILL SET UP THE COLDEST NIGHT OF THE FORECAST PERIOD WITH MUCH OF THE AREA BOTTOMING OUT IN THE LOWER 20S AND THE REMAINDER OF THE AREA IN THE MID TO UPPER 20S. A BROAD UPPER TROUGH WILL KEEP THE ARKLAMISS REGION DRY WITH BELOW NORMAL TEMPERATURES THROUGH THURSDAY NIGHT. /27/22/ LONG TERM...FRIDAY THROUGH TUESDAY...AS WE GO INTO FRIDAY AND INTO THE WEEKEND...THE PATTERN WILL BECOME MORE ZONAL AS MILDER PACIFIC AIR PUSHES TEMPS BACK TO NEAR NORMAL. COLD AIR ADVECTION WILL HOLD TEMPS INTO THE 50S ON THURSDAY AS A REINFORCING FRONT PUSHES THROUGH THE REGION. THE ASSOCIATED SURFACE HIGH WILL SHIFT EAST OF OUR CWA FRIDAY AFTERNOON. DRY WEATHER WILL CONTINUE THURSDAY INTO FRIDAY BUT A WEAK DISTURBANCE WILL DROP OVER THE SOUTHERN PLAINS THURSDAY AND HELP DEVELOP A WEAK SURFACE LOW. WARM AIR ADVECTION AHEAD OF THIS SYSTEM WILL BRING SOME LIGHT RAIN BACK INTO ARKLAMISS ON FRIDAY NIGHT AS A WEAK WARM FRONT PUSHES INTO THE REGION. THE GFS...EURO AND NAVGEM WERE PRETTY LIGHT WITH THE RAINFALL FOR FRIDAY NIGHT. THE SYSTEM WILL EXIT EAST ON SATURDAY AS FLAT UPPER RIDGING PUSHES ACROSS THE REGION. HIGHS WILL RISE INTO THE 50S NORTH TO AROUND 70 SOUTH FOR SATURDAY AS WELL AS 60S AND 70S ON SUNDAY. LOWS WILL BE IN THE 40S. AS WE GO INTO SUNDAY NIGHT ANOTHER WAVE WILL APPROACH FROM THE WEST. A STRONGER WARM FRONT WILL PUSH INTO THE REGION SUNDAY NIGHT INTO MONDAY. INSTABILITY WILL BUILD ACROSS THE REGION FOR SUNDAY NIGHT WITH A CHANCE OF THUNDERSTORMS. AS WE GO INTO MONDAY MOISTURE CONVERGENCE WILL INCREASE...AS WELL AS SOME JET DYNAMICS AND ASCENT ACROSS THE REGION. THE CIPS MODEL SHOWS SOME LIMITED SEVERE POTENTIAL WITH THIS SYSTEM...AS A STRONG UPPER TROUGH PUSHES THROUGH THE PLAINS FOR EARLY NEXT WEEK. ALSO PWATS WILL BE AROUND 1.7 WHICH IS THE MAX PERCENTILE FOR THIS TIME OF YEAR FOR SOME LOCALLY HEAVY RAINFALL POTENTIAL. THERE WERE SOME MODEL DISCREPANCIES WITH THIS SYSTEM THE GFS...NAVGEM AND GFS ENSEMBLES BRING THE COLD FRONT THROUGH MONDAY NIGHT INTO EARLY TUESDAY...WHILE THE EURO BROUGHT THE FRONT THROUGH ON SUNDAY NIGHT. BEING THIS FAR OUT WILL GO WITH THE SLOWER GFS SOLUTION AND WILL WATCH THE STRONG STORM POTENTIAL...BUT NOT MENTION IT IN THE HWO BEING A WEEK AWAY. AS FAR AS TEMPS ARE CONCERN MADE SOME SLIGHT ADJUSTMENTS TO MEX GUIDANCE TOWARD GMOS...HPC AND SOME MEN ENSEMBLES DURING THE PERIOD. AS FAR AS POPS ARE CONCERN WENT WITH A BLEND OF MEX AND MEN ENSEMBLES. /17/ && .AVIATION... A COLD FRONT EXTENDS ACROSS THE CENTRAL PORTIONS OF THE STATE THIS AFTERNOON AND IS SLOWLY MOVING SOUTH. A FEW LIGHT RAINSHOWERS WERE NOTED ALONG THE FRONT. MOSTLY VFR CEILINGS ARE OCCURRING NORTH OF THE BOUNDARY WHILE A MIX OF MVFR/VFR CEILINGS ARE OCCURRING SOUTH. RAIN WILL BE ON THE INCREASE THIS EVENING INTO THE OVERNIGHT HOURS AND EXPECT A RETURN TO MVFR AND IFR CONDITIONS LATER TONIGHT OVER MOST SITES. LIGHT SLEET MAY MIX WITH THE RAIN 09Z-13Z WED AT GLH-GWO-GTR. CONDITIONS WILL GRADUALLY IMPROVE FROM THE NORTH WED. && .PRELIMINARY POINT TEMPS/POPS... JACKSON 36 42 24 55 / 100 45 10 4 MERIDIAN 39 44 23 56 / 91 53 9 4 VICKSBURG 37 41 24 55 / 100 34 10 4 HATTIESBURG 45 46 30 57 / 100 81 14 5 NATCHEZ 38 41 26 54 / 100 81 13 8 GREENVILLE 33 40 24 51 / 90 21 6 2 GREENWOOD 34 40 21 54 / 86 21 6 3 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ CME/27/17
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1153 AM CST MON FEB 24 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 350 AM CST MON FEB 24 2014 1038 MB ARCTIC HIGH PRESSURE ACROSS SRN ALBERTA AND SRN SASKATCHEWAN WILL MOVE INTO SOUTH DAKOTA BY 12Z TUESDAY MORNING. AN ARCTIC FRONT ACROSS NRN MT IS EXPECTED TO MOVE INTO THE FCST AREA BY LATE AFTN AND BE THROUGH THE FCST AREA AND ACROSS KS BY TUESDAY MORNING. LOWS IN THE SINGLE DIGITS ARE EXPECTED TONIGHT WITH WIND CHILL READINGS AROUND 10 BELOW TO PERHAPS 15 BELOW ZERO ACROSS NORTHERN NEB. THE MODEL CONSENSUS SUGGESTS A PERIOD OF LIGHT SNOW DEVELOPING...MAINLY ACROSS WRN NEBRASKA...AS THE FRONT MOVES THROUGH. SNOWFALL AMOUNTS SHOULD BE LESS THAN AN INCH AND MAINLY A DUSTING. THERE IS QUITE A VARIETY OF MAX TEMPERATURE FORECASTS TO CHOOSE FROM TODAY. THE FORECAST FOLLOWS A BLEND OF NAM...GEM REG...ECM AND MET PLUS BIAS CORRECTION FOR HIGHS IN THE UPPER 20S NORTH TO UPPER 30S SOUTH. THE NAM IS ACTUALLY FORECASTING MID 40S AT NORTH PLATTE WHILE THE RAP SHOWS UPPER 20S AND THE ECM MID 30S. THIS IS A FUNCTION OF THE SKY COVER INDICATED IN THE MODELS AND SOME SOLNS SHOW A PERIOD OF CLEARING AHEAD OF THE ARCTIC FRONT. THE MODEL CONSENSUS SUGGESTS CLEARING ACROSS WRN/SWRN NEB...KAIA-KOGA-KIML AS A RESULT OF SOME SOUTHWEST WINDS DEVELOPING. EAST OF THAT AREA IT LOOKS LIKE ARCTIC DRAPE SHOULD CONTINUE WITH SOUTH WINDS. THE LIGHT TO MODERATE SNOW ON RADAR EARLY THIS MORNING ACROSS NCNTL NEB IS MOVING RAPIDLY EAST AND SHOULD BE REPLACED BY A SECOND AREA OF SNOW LATER THIS MORNING A BIT FARTHER NORTH AND EAST. THIS SNOW IS CURRENTLY SHOWING ON THE KUNR RADAR ACROSS WRN SD. THE MODELS GENERATE A THIRD AREA OF SNOW THIS AFTERNOON BUT THIS SHOULD PASS MOSTLY NORTH AND EAST OF THE FORECAST AREA. THIS AREA OF SNOW IS CURRENTLY ACROSS SERN MT. BEST SNOWFALL IS EXPECTED ACROSS BOYD COUNTY WITH QPF RANGES FROM LESS THAN 0.10 INCHES IN THE UKMET...GEF AND GFS TO 0.30 INCHES IN THE NMM WEST. THIS IS A WIDE RANGE AND THE CONSENSUS IS AROUND 0.15 INCHES. A 15 TO 20 TO 1 SNOW RATIO WAS USED BASED ON THE COBB METHODOLOGY. OBSERVED SNOWFALL SUNDAY AFTN AND SUNDAY NIGHT WAS IN THIS RANGE. THE NAM CONTINUES TO ADVERTISE POCKETS OF STRONG FRONTOGENESIS WHICH COULD LEAD TO BANDED SNOW DEVELOPMENT. THIS HAS BEEN THE OPERATIVE MODE IN MANY INSTANCES OVER THE PAST 36 HOURS HOWEVER THE NAM...ARF AND NMM MODELS HAVE SHOWN POOR SKILL FORECASTING THE LOCATION OF THESE BANDS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 350 AM CST MON FEB 24 2014 TEMPS FOR THE END OF FEBRUARY AND INTO MARCH WILL BE DOMINATED BY COLD ARCTIC AIR WITH WELL BELOW NORMAL READINGS. WEDNESDAY LOOKS TO BE THE ONLY DAY WE MAY BE WITHIN 10 DEGREES OF NORMAL FOR HIGHS INTO THE NEXT WEEKEND. ALSO WILL SEE AN ACTIVE PERIOD WITH SEVERAL CHANCES FOR SNOW THROUGHOUT THE WEEK AND INTO THE WEEKEND. TUESDAY WILL SEE ANOTHER DISTURBANCE DRIFTING ACROSS THE SW PORTIONS OF THE CWA. BATTLE WILL BE BETWEEN RADIATION OF A HIGHER LATE FEBRUARY SUN ANGLE AND SNOWFALL RATES...ON TOP OF A SNOW PACK. PLOWED ROADS TODAY FOR THE MOST PART BECAME WET AND IN SOME AREAS EVEN PARTIALLY DRIED...DESPITE CLOUDY SKIES. THINK CLOUDS WILL BE THICKER LIMITING SOLAR IMPACT...HOWEVER MODELS ARE ONLY PRODUCING LIGHT SNOW. DAYTIME SNOW OF A HALF INCH TO 1.5 INCHES FOR THE MOST PART WITH A 15 TO 1 RATIO...HIGHEST ACROSS THE SOUTHEASTERN PAN HANDLE AND SW NEB. BY TUESDAY NIGHT ARCTIC HIGH PRESSURE WILL BE DRIFTING OVERHEAD. CENTER CROSSES OVER THE CWA BETWEEN 04Z AND 09Z. BY 12Z THE HIGH WILL BE TO THE SE WITH SOUTHWESTERLY WINDS TO BE ON THE INCREASING...ALONG WITH WAA. LOWS INITIALLY EXPECTED WITH THE CENTER OF THE HIGH OVERHEAD...EARLY IN THE NIGHT...HOWEVER WITH THE EXPECTED SNOW PACK...DECOUPLING WILL KEEP WINDS FROM MIXING TO THE GROUND UNTIL SUNRISE OR LATER. THIS MAY ALLOW A COUPLE OF DEGREES FURTHER OF A DROP AFTER CENTER PASSES. EITHER WAY...EXPECT LOWS TO FALL TO A FEW DEGREES ON EITHER SIDE OF ZERO. WITH THE WAA FOR WED...HIGHS WILL REBOUND ABOVE FREEZING. WARMEST GUIDANCE IS INTO THE 40S...HOWEVER THINK SNOW PACK WILL HOLD HIGHS IN THE 30S. NEXT COLD FRONT ARRIVES FOR THURSDAY WITH TEMPS TO TAKE A DOWNWARD TREND. A COUPLE OF REINFORCING COLD FRONT WILL CONTINUE TO TAKE TEMPS LOWER INTO THE WEEKEND. THIS WILL BE COUPLED WITH SEVERAL DISTURBANCE TO RIDE ACROSS THE HIGH PLAINS WITH SEVERAL CHANCES FOR SNOW. SNOW IS NOT EXPECTED TO BE CONSTANT...HOWEVER CHANCES FOR AT LEAST LIGHT SNOW IN ANY 12 HOURS PERIOD WILL RESULT IN MANY PERIODS WITH SNOW IN THE FORECAST. NORMAL HIGHS THIS TIME OF YEAR SHOULD BE INTO THE 40S WITH LOWS IN THE TEENS. MODELS ARE IN GOOD AGREEMENT WITH HIGHS ONLY IN THE 10S AND 20S FROM FRIDAY THROUGH THE WEEKEND AS THE COLD AIR BLANKETS MUCH OF THE CONUS. COLDEST GUIDANCE IS THE EC WITH MANY LOCATIONS NOT WARMING ABOVE SINGLE DIGITS FOR THE WEEKEND. THIS IS NEARLY 40 DEGREES BELOW NORMAL. SUN ANGLE CONTINUES TO INCREASE...AND RECORD LOW MAXES ARE IN THE SINGLE DIGITS...SO DO NOT WANT TO GO WITH THE RECORD COLD FROM THE EC YET...THUS FORECAST IS FAVORING A SLIGHTLY WARMER GFS AT THIS TIME. HOWEVER WILL CONTINUE TO KEEP AN EYE ON THIS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1153 AM CST MON FEB 24 2014 THE MAIN CONCERN OVER THE NEXT 24 HOURS IS THE PASSAGE OF A COLD FRONT THROUGH WESTERN NEBRASKA. WINDS WILL RAPIDLY SWITCH TO NORTHWEST AND INCREASE IN SPEED LATE THIS AFTERNOON. SNOW SHOWERS MAY ACCOMPANY THE FRONT...ESPECIALLY ACROSS NORTHERN NEBRASKA INCLUDING THE KVTN TERMINAL. CEILINGS SHOULD RAISE TO VFR OVERNIGHT BEHIND THE FRONT AS WINDS STAY STRONG ENOUGH TO PREVENT FOG FORMATION. STRATUS WILL WORK INTO SOUTHWEST NEBRASKA AGAIN TUESDAY MORNING...BUT THE PRECIPITATION SHOULD HOLD OFF UNTIL AFTER 25/18Z. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...SNIVELY/TAYLOR
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
532 AM CST MON FEB 24 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 350 AM CST MON FEB 24 2014 1038 MB ARCTIC HIGH PRESSURE ACROSS SRN ALBERTA AND SRN SASKATCHEWAN WILL MOVE INTO SOUTH DAKOTA BY 12Z TUESDAY MORNING. AN ARCTIC FRONT ACROSS NRN MT IS EXPECTED TO MOVE INTO THE FCST AREA BY LATE AFTN AND BE THROUGH THE FCST AREA AND ACROSS KS BY TUESDAY MORNING. LOWS IN THE SINGLE DIGITS ARE EXPECTED TONIGHT WITH WIND CHILL READINGS AROUND 10 BELOW TO PERHAPS 15 BELOW ZERO ACROSS NORTHERN NEB. THE MODEL CONSENSUS SUGGESTS A PERIOD OF LIGHT SNOW DEVELOPING...MAINLY ACROSS WRN NEBRASKA...AS THE FRONT MOVES THROUGH. SNOWFALL AMOUNTS SHOULD BE LESS THAN AN INCH AND MAINLY A DUSTING. THERE IS QUITE A VARIETY OF MAX TEMPERATURE FORECASTS TO CHOOSE FROM TODAY. THE FORECAST FOLLOWS A BLEND OF NAM...GEM REG...ECM AND MET PLUS BIAS CORRECTION FOR HIGHS IN THE UPPER 20S NORTH TO UPPER 30S SOUTH. THE NAM IS ACTUALLY FORECASTING MID 40S AT NORTH PLATTE WHILE THE RAP SHOWS UPPER 20S AND THE ECM MID 30S. THIS IS A FUNCTION OF THE SKY COVER INDICATED IN THE MODELS AND SOME SOLNS SHOW A PERIOD OF CLEARING AHEAD OF THE ARCTIC FRONT. THE MODEL CONSENSUS SUGGESTS CLEARING ACROSS WRN/SWRN NEB...KAIA-KOGA-KIML AS A RESULT OF SOME SOUTHWEST WINDS DEVELOPING. EAST OF THAT AREA IT LOOKS LIKE ARCTIC DRAPE SHOULD CONTINUE WITH SOUTH WINDS. THE LIGHT TO MODERATE SNOW ON RADAR EARLY THIS MORNING ACROSS NCNTL NEB IS MOVING RAPIDLY EAST AND SHOULD BE REPLACED BY A SECOND AREA OF SNOW LATER THIS MORNING A BIT FARTHER NORTH AND EAST. THIS SNOW IS CURRENTLY SHOWING ON THE KUNR RADAR ACROSS WRN SD. THE MODELS GENERATE A THIRD AREA OF SNOW THIS AFTERNOON BUT THIS SHOULD PASS MOSTLY NORTH AND EAST OF THE FORECAST AREA. THIS AREA OF SNOW IS CURRENTLY ACROSS SERN MT. BEST SNOWFALL IS EXPECTED ACROSS BOYD COUNTY WITH QPF RANGES FROM LESS THAN 0.10 INCHES IN THE UKMET...GEF AND GFS TO 0.30 INCHES IN THE NMM WEST. THIS IS A WIDE RANGE AND THE CONSENSUS IS AROUND 0.15 INCHES. A 15 TO 20 TO 1 SNOW RATIO WAS USED BASED ON THE COBB METHODOLOGY. OBSERVED SNOWFALL SUNDAY AFTN AND SUNDAY NIGHT WAS IN THIS RANGE. THE NAM CONTINUES TO ADVERTISE POCKETS OF STRONG FRONTOGENESIS WHICH COULD LEAD TO BANDED SNOW DEVELOPMENT. THIS HAS BEEN THE OPERATIVE MODE IN MANY INSTANCES OVER THE PAST 36 HOURS HOWEVER THE NAM...ARF AND NMM MODELS HAVE SHOWN POOR SKILL FORECASTING THE LOCATION OF THESE BANDS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 350 AM CST MON FEB 24 2014 TEMPS FOR THE END OF FEBRUARY AND INTO MARCH WILL BE DOMINATED BY COLD ARCTIC AIR WITH WELL BELOW NORMAL READINGS. WEDNESDAY LOOKS TO BE THE ONLY DAY WE MAY BE WITHIN 10 DEGREES OF NORMAL FOR HIGHS INTO THE NEXT WEEKEND. ALSO WILL SEE AN ACTIVE PERIOD WITH SEVERAL CHANCES FOR SNOW THROUGHOUT THE WEEK AND INTO THE WEEKEND. TUESDAY WILL SEE ANOTHER DISTURBANCE DRIFTING ACROSS THE SW PORTIONS OF THE CWA. BATTLE WILL BE BETWEEN RADIATION OF A HIGHER LATE FEBRUARY SUN ANGLE AND SNOWFALL RATES...ON TOP OF A SNOW PACK. PLOWED ROADS TODAY FOR THE MOST PART BECAME WET AND IN SOME AREAS EVEN PARTIALLY DRIED...DESPITE CLOUDY SKIES. THINK CLOUDS WILL BE THICKER LIMITING SOLAR IMPACT...HOWEVER MODELS ARE ONLY PRODUCING LIGHT SNOW. DAYTIME SNOW OF A HALF INCH TO 1.5 INCHES FOR THE MOST PART WITH A 15 TO 1 RATIO...HIGHEST ACROSS THE SOUTHEASTERN PAN HANDLE AND SW NEB. BY TUESDAY NIGHT ARCTIC HIGH PRESSURE WILL BE DRIFTING OVERHEAD. CENTER CROSSES OVER THE CWA BETWEEN 04Z AND 09Z. BY 12Z THE HIGH WILL BE TO THE SE WITH SOUTHWESTERLY WINDS TO BE ON THE INCREASING...ALONG WITH WAA. LOWS INITIALLY EXPECTED WITH THE CENTER OF THE HIGH OVERHEAD...EARLY IN THE NIGHT...HOWEVER WITH THE EXPECTED SNOW PACK...DECOUPLING WILL KEEP WINDS FROM MIXING TO THE GROUND UNTIL SUNRISE OR LATER. THIS MAY ALLOW A COUPLE OF DEGREES FURTHER OF A DROP AFTER CENTER PASSES. EITHER WAY...EXPECT LOWS TO FALL TO A FEW DEGREES ON EITHER SIDE OF ZERO. WITH THE WAA FOR WED...HIGHS WILL REBOUND ABOVE FREEZING. WARMEST GUIDANCE IS INTO THE 40S...HOWEVER THINK SNOW PACK WILL HOLD HIGHS IN THE 30S. NEXT COLD FRONT ARRIVES FOR THURSDAY WITH TEMPS TO TAKE A DOWNWARD TREND. A COUPLE OF REINFORCING COLD FRONT WILL CONTINUE TO TAKE TEMPS LOWER INTO THE WEEKEND. THIS WILL BE COUPLED WITH SEVERAL DISTURBANCE TO RIDE ACROSS THE HIGH PLAINS WITH SEVERAL CHANCES FOR SNOW. SNOW IS NOT EXPECTED TO BE CONSTANT...HOWEVER CHANCES FOR AT LEAST LIGHT SNOW IN ANY 12 HOURS PERIOD WILL RESULT IN MANY PERIODS WITH SNOW IN THE FORECAST. NORMAL HIGHS THIS TIME OF YEAR SHOULD BE INTO THE 40S WITH LOWS IN THE TEENS. MODELS ARE IN GOOD AGREEMENT WITH HIGHS ONLY IN THE 10S AND 20S FROM FRIDAY THROUGH THE WEEKEND AS THE COLD AIR BLANKETS MUCH OF THE CONUS. COLDEST GUIDANCE IS THE EC WITH MANY LOCATIONS NOT WARMING ABOVE SINGLE DIGITS FOR THE WEEKEND. THIS IS NEARLY 40 DEGREES BELOW NORMAL. SUN ANGLE CONTINUES TO INCREASE...AND RECORD LOW MAXES ARE IN THE SINGLE DIGITS...SO DO NOT WANT TO GO WITH THE RECORD COLD FROM THE EC YET...THUS FORECAST IS FAVORING A SLIGHTLY WARMER GFS AT THIS TIME. HOWEVER WILL CONTINUE TO KEEP AN EYE ON THIS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 531 AM CST MON FEB 24 2014 MIXED LOCAL LIFR/IFR/MVFR/LOCAL VFR THIS MORNING ARE EXPECTED TO IMPROVE TO MVFR/VFR THIS AFTERNOON AND TONIGHT. LOW CIGS AND VSBY ACROSS WRN NEB ARE EXPECTED TO IMPROVE TO VFR THIS AFTERNOON AS THE RESULT OF A CLEARING LINE THAT IS EXPECTED TO DEVELOP. THE CLEARING LINE COULD MOVE TO KIEN- KTIF- KLBF BEFORE AN ARCTIC FRONT SWEEPS IN THIS AFTERNOON AND LOWERS CIGS TO MVFR. A BAND OF LIGHT SNOW AND MVFR CIGS/VSBY IS EXPECTED TO DEVELOP LATE THIS AFTERNOON AND THIS EVENING...MAINLY ACROSS WRN NEB. THIS IS ASSOCIATED WITH THE PASSAGE OF THE ARCTIC FRONT. SNOW AND MVFR/IFR CIGS ARE EXPECTED TO DEVELOP TODAY...GENERALLY FROM KIEN-KTIF-KONL NORTHWARD WITH FLIGHT CONDITIONS WORSENING NORTHWARD. FLIGHT CONDITIONS SHOULD IMPROVE WEST TO EAST LATE THIS AFTERNOON AS THE DISTURBANCE TRACKING THROUGH SD MOVES EAST OF THE AREA. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
350 AM CST MON FEB 24 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 350 AM CST MON FEB 24 2014 1038 MB ARCTIC HIGH PRESSURE ACROSS SRN ALBERTA AND SRN SASKATCHEWAN WILL MOVE INTO SOUTH DAKOTA BY 12Z TUESDAY MORNING. AN ARCTIC FRONT ACROSS NRN MT IS EXPECTED TO MOVE INTO THE FCST AREA BY LATE AFTN AND BE THROUGH THE FCST AREA AND ACROSS KS BY TUESDAY MORNING. LOWS IN THE SINGLE DIGITS ARE EXPECTED TONIGHT WITH WIND CHILL READINGS AROUND 10 BELOW TO PERHAPS 15 BELOW ZERO ACROSS NORTHERN NEB. THE MODEL CONSENSUS SUGGESTS A PERIOD OF LIGHT SNOW DEVELOPING...MAINLY ACROSS WRN NEBRASKA...AS THE FRONT MOVES THROUGH. SNOWFALL AMOUNTS SHOULD BE LESS THAN AN INCH AND MAINLY A DUSTING. THERE IS QUITE A VARIETY OF MAX TEMPERATURE FORECASTS TO CHOOSE FROM TODAY. THE FORECAST FOLLOWS A BLEND OF NAM...GEM REG...ECM AND MET PLUS BIAS CORRECTION FOR HIGHS IN THE UPPER 20S NORTH TO UPPER 30S SOUTH. THE NAM IS ACTUALLY FORECASTING MID 40S AT NORTH PLATTE WHILE THE RAP SHOWS UPPER 20S AND THE ECM MID 30S. THIS IS A FUNCTION OF THE SKY COVER INDICATED IN THE MODELS AND SOME SOLNS SHOW A PERIOD OF CLEARING AHEAD OF THE ARCTIC FRONT. THE MODEL CONSENSUS SUGGESTS CLEARING ACROSS WRN/SWRN NEB...KAIA-KOGA-KIML AS A RESULT OF SOME SOUTHWEST WINDS DEVELOPING. EAST OF THAT AREA IT LOOKS LIKE ARCTIC DRAPE SHOULD CONTINUE WITH SOUTH WINDS. THE LIGHT TO MODERATE SNOW ON RADAR EARLY THIS MORNING ACROSS NCNTL NEB IS MOVING RAPIDLY EAST AND SHOULD BE REPLACED BY A SECOND AREA OF SNOW LATER THIS MORNING A BIT FARTHER NORTH AND EAST. THIS SNOW IS CURRENTLY SHOWING ON THE KUNR RADAR ACROSS WRN SD. THE MODELS GENERATE A THIRD AREA OF SNOW THIS AFTERNOON BUT THIS SHOULD PASS MOSTLY NORTH AND EAST OF THE FORECAST AREA. THIS AREA OF SNOW IS CURRENTLY ACROSS SERN MT. BEST SNOWFALL IS EXPECTED ACROSS BOYD COUNTY WITH QPF RANGES FROM LESS THAN 0.10 INCHES IN THE UKMET...GEF AND GFS TO 0.30 INCHES IN THE NMM WEST. THIS IS A WIDE RANGE AND THE CONSENSUS IS AROUND 0.15 INCHES. A 15 TO 20 TO 1 SNOW RATIO WAS USED BASED ON THE COBB METHODOLOGY. OBSERVED SNOWFALL SUNDAY AFTN AND SUNDAY NIGHT WAS IN THIS RANGE. THE NAM CONTINUES TO ADVERTISE POCKETS OF STRONG FRONTOGENESIS WHICH COULD LEAD TO BANDED SNOW DEVELOPMENT. THIS HAS BEEN THE OPERATIVE MODE IN MANY INSTANCES OVER THE PAST 36 HOURS HOWEVER THE NAM...ARF AND NMM MODELS HAVE SHOWN POOR SKILL FORECASTING THE LOCATION OF THESE BANDS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 350 AM CST MON FEB 24 2014 TEMPS FOR THE END OF FEBRUARY AND INTO MARCH WILL BE DOMINATED BY COLD ARCTIC AIR WITH WELL BELOW NORMAL READINGS. WEDNESDAY LOOKS TO BE THE ONLY DAY WE MAY BE WITHIN 10 DEGREES OF NORMAL FOR HIGHS INTO THE NEXT WEEKEND. ALSO WILL SEE AN ACTIVE PERIOD WITH SEVERAL CHANCES FOR SNOW THROUGHOUT THE WEEK AND INTO THE WEEKEND. TUESDAY WILL SEE ANOTHER DISTURBANCE DRIFTING ACROSS THE SW PORTIONS OF THE CWA. BATTLE WILL BE BETWEEN RADIATION OF A HIGHER LATE FEBRUARY SUN ANGLE AND SNOWFALL RATES...ON TOP OF A SNOW PACK. PLOWED ROADS TODAY FOR THE MOST PART BECAME WET AND IN SOME AREAS EVEN PARTIALLY DRIED...DESPITE CLOUDY SKIES. THINK CLOUDS WILL BE THICKER LIMITING SOLAR IMPACT...HOWEVER MODELS ARE ONLY PRODUCING LIGHT SNOW. DAYTIME SNOW OF A HALF INCH TO 1.5 INCHES FOR THE MOST PART WITH A 15 TO 1 RATIO...HIGHEST ACROSS THE SOUTHEASTERN PAN HANDLE AND SW NEB. BY TUESDAY NIGHT ARCTIC HIGH PRESSURE WILL BE DRIFTING OVERHEAD. CENTER CROSSES OVER THE CWA BETWEEN 04Z AND 09Z. BY 12Z THE HIGH WILL BE TO THE SE WITH SOUTHWESTERLY WINDS TO BE ON THE INCREASING...ALONG WITH WAA. LOWS INITIALLY EXPECTED WITH THE CENTER OF THE HIGH OVERHEAD...EARLY IN THE NIGHT...HOWEVER WITH THE EXPECTED SNOW PACK...DECOUPLING WILL KEEP WINDS FROM MIXING TO THE GROUND UNTIL SUNRISE OR LATER. THIS MAY ALLOW A COUPLE OF DEGREES FURTHER OF A DROP AFTER CENTER PASSES. EITHER WAY...EXPECT LOWS TO FALL TO A FEW DEGREES ON EITHER SIDE OF ZERO. WITH THE WAA FOR WED...HIGHS WILL REBOUND ABOVE FREEZING. WARMEST GUIDANCE IS INTO THE 40S...HOWEVER THINK SNOW PACK WILL HOLD HIGHS IN THE 30S. NEXT COLD FRONT ARRIVES FOR THURSDAY WITH TEMPS TO TAKE A DOWNWARD TREND. A COUPLE OF REINFORCING COLD FRONT WILL CONTINUE TO TAKE TEMPS LOWER INTO THE WEEKEND. THIS WILL BE COUPLED WITH SEVERAL DISTURBANCE TO RIDE ACROSS THE HIGH PLAINS WITH SEVERAL CHANCES FOR SNOW. SNOW IS NOT EXPECTED TO BE CONSTANT...HOWEVER CHANCES FOR AT LEAST LIGHT SNOW IN ANY 12 HOURS PERIOD WILL RESULT IN MANY PERIODS WITH SNOW IN THE FORECAST. NORMAL HIGHS THIS TIME OF YEAR SHOULD BE INTO THE 40S WITH LOWS IN THE TEENS. MODELS ARE IN GOOD AGREEMENT WITH HIGHS ONLY IN THE 10S AND 20S FROM FRIDAY THROUGH THE WEEKEND AS THE COLD AIR BLANKETS MUCH OF THE CONUS. COLDEST GUIDANCE IS THE EC WITH MANY LOCATIONS NOT WARMING ABOVE SINGLE DIGITS FOR THE WEEKEND. THIS IS NEARLY 40 DEGREES BELOW NORMAL. SUN ANGLE CONTINUES TO INCREASE...AND RECORD LOW MAXES ARE IN THE SINGLE DIGITS...SO DO NOT WANT TO GO WITH THE RECORD COLD FROM THE EC YET...THUS FORECAST IS FAVORING A SLIGHTLY WARMER GFS AT THIS TIME. HOWEVER WILL CONTINUE TO KEEP AN EYE ON THIS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1127 PM CST SUN FEB 23 2014 SURFACE WIND AND THE FIRST 1000M ABOVE THE SURFACE SHOW SOUTHEAST WIND WHICH IS UPSLOPE. THE RESULT IS STRATUS WITH CEILING 1000 FEET AGL OR LOWER. THERE IS SOME UNCERTAINTY REGARDING HOW FAR EAST IT WILL SPREAD. THE TERRAIN WOULD INDICATE THAT THE LOW CEILINGS WOULD REACH TO JUST WEST OF VTN-TIF-LBF. STILL...IT WILL BE CLOSE ENOUGH TO THOSE SITES TO JUSTIFY INCLUDING AT LEAST AN INTERMITTENT CONDITION OF CEILING BELOW 1000 FEET AGL. THE SNOW BANDS INDICATED ON RADAR ARE LIKELY TO STAY BETWEEN VTN AND LBF. HOWEVER...THE HEAVIER SNOW WILL CONTINUE AT TIF...MHN AND BBW UNTIL ABOUT 10Z WHEN THE CONDITIONS BECOME LESS FAVORABLE FOR BANDED MODERATE TO HEAVY SNOW. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1135 PM CST SUN FEB 23 2014 .UPDATE... ISSUED AT 1135 PM CST SUN FEB 23 2014 NO CHANGES PLANNED TO LATE EVENING UPDATE. FORECAST LOOKS IN GOOD SHAPE FOR EARLIER DECISION OF DELAYING WIND CHILL HEADLINES UNTIL 12 AM CST. DVL BASIN AREA NOW WELL WITHIN CRITERIA...WITH THE NORTHERN VALLEY NEARING 25 BELOW. LAKE OF THE WOODS STILL QUITE WARM BUT CLOUD COVER OVER AREA EXPECTED TO MOVE EAST IN THE 06Z TO 08Z TIMEFRAME. UPDATE ISSUED AT 955 PM CST SUN FEB 23 2014 MAIN CHALLENGE FOR TONIGHT IS INHERITED WIND CHILL HEADLINES. WARMEST TEMPS AS OF RIGHT NOW ARE OVER SOUTHEASTERN ND...AND MODELS SHOWING RANSOM/SARGENT HAVING LIGHTEST WINDS TONIGHT AS WELL (ALREADY AROUND 5KTS). WILL REMOVE THESE TWO COUNTIES FROM ADVISORY AS WIND CHILLS ARE NOT EXPECTED TO REACH CRITERIA. FOR THE REST OF THE AREA...WIND CHILLS NEARING CRITERIA WHERE BREEZY WINDS ARE STILL GOING OVER NORTHEASTERN ND. EXPECT APPARENT TEMPS IN THIS AREA TO WARM UP A BIT AS WINDS DIE DOWN...THEN BEGIN FALLING AGAIN IN THE 06Z TO 09Z TIMEFRAME ALONG WITH THE REST OF THE CWA. DELAYED COUNTIES OUTSIDE OF NORTHEASTER ND/NORTHERN RRV UNTIL 12 AM BUT 3 AM IS THE MORE LIKELY TIMEFRAME FOR MEETING ADVISORY CRITERIA. THIS WILL MATCH UP NICELY WITH NEIGHBORING WFOS TO THE EAST AND SOUTH. NO OTHER CHANGES MADE TO THIS FCST. FOR TOMORROW...THE LATEST NAM AND RUC CONTINUE TO BRING PRECIP INTO THE SOUTHWESTERN ZONES AFTER NOON TIMEFRAME...WITH THE RUC HAVING DRIER QPFS. LOOKS LIKE MOST SNOW SHOULD BE SOUTH OF THE HWY 200 CORRIDOR OR PERHAPS EVEN THE I 94 CORRIDOR. NO CHANGES TO POPS MADE. UPDATE ISSUED AT 656 PM CST SUN FEB 23 2014 CLEAR SKIES ACROSS CWA TONIGHT...WITH WINDS STILL IN THE 15 TO 25 MPH RANGE FOR MUCH OF THE AREA. OVER THE NEXT COUPLE OF HOURS...WINDS SHOULD BEGIN TO DIE OFF ENOUGH TO ALLOW TEMPS TO BEGIN TO FALL YET HIGH ENOUGH TO BRING WIND CHILLS IN THE 25 BELOW TO 35 BELOW RANGE. NO PLANNED CHANGES TO HEADLINES TONIGHT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 325 PM CST SUN FEB 23 2014 CHALLENGES INCLUDE WIND CHILLS TONIGHT AND LOW PRECIPITATION CHANCES TOMORROW. GLOBAL MODELS ARE IN GOOD AGREEMENT AND WILL USE A BLENDED SOLUTION. FOR TONIGHT...SCT-BKN CLOUD COVER WILL REMAIN CONFINED TO THE NORTHEAST FORECAST AREA AS CLOUD DECK AROUND JAMES BAY LOW CONTINUES TO PIVOT TO THE SOUTH. ALL OTHER AREAS WILL REMAIN MOSTLY CLEAR AS SURFACE RIDGE BUILDS ACROSS EASTERN ND INTO SOUTHWEST MN. CURRENT TEMPERATURES UNDER THIS RIDGE ARE IN THE SINGLE DIGITS BELOW ZERO ACROSS ALBERTA AND SOUTHERN SASKATCHEWAN AND THIS COLDER AIR MASS WILL BEGIN TO SAG SOUTHWARD OVERNIGHT. NORTHWEST WIND WILL REMAIN ELEVATED BETWEEN 5 AND 10 MPH...BUT TEMPERATURE GUIDANCE IN FAIR AGREEMENT SHOWING OVERNIGHT LOWS DROPPING INTO THE LOW TEENS BELOW ZERO. AIR TEMPERATURES AND WINDS WILL RESULT IN WIND CHILL VALUES FROM 25 TO 35 BELOW...SO WILL ISSUE A CWA-WIDE WIND CHILL ADVISORY FROM 04 UTC TONIGHT UNTIL 16 UTC MONDAY. SURFACE LOW WILL DIVE SOUTH ALONG THE LEE OF THE ROCKIES ON MONDAY WITH WARM AIR ADVECTION SNOW DEVELOPING MAINLY ACROSS SD. NORTHERN EXTENT OF THIS SNOW SHIELD MAY CLIP THE SOUTHERN FORECAST AREA... SO WILL KEEP CHANCE POPS MAINLY ALONG AND SOUTH OF THE I-94/HWY 10 CORRIDOR. WAS ABLE TO REMOVE POPS MONDAY MORNING WITH SLOWER FORWARD PROGRESSION IN THE MODELS. ANY ACCUMULATION WILL BE MINIMAL...AROUND A HALF INCH OR LESS. TEMPERATURES TO BE A BIT COOLER THAN TODAY...BUT STILL ABOVE ZERO WITH NORTHWEST WIND BETWEEN 5 AND 15 MPH. LINGERING SNOW SHOWERS POSSIBLE ACROSS SOUTHEAST FORECAST AREA MONDAY NIGHT...WITH ALL OTHER AREAS DRY. MOSTLY CLEAR SKIES... TEMPERATURES BELOW ZERO AND WIND AROUND 10 MPH WILL LIKELY NECESSITATE ANOTHER WIND CHILL ADVISORY. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 325 PM CST SUN FEB 23 2014 MORE OF THE SAME FOR TUESDAY AND WEDNESDAY AS 1035 TO 1040 HPA SURFACE HIGH DROPS SOUTH FROM CANADA AND MOVES ACROSS THE NORTHERN PLAINS. EXPECT MORE SUN THAN CLOUDS WITH PERSISTENT BREEZY CONDITIONS FROM THE WEST-NORTHWEST. HIGH TEMPERATURES TUESDAY AROUND THE ZERO MARK WILL WARM SLIGHTLY BY WEDNESDAY INTO THE SINGLE DIGITS TO MID TEENS ABOVE ZERO. THE SEEMINGLY ENDLESS STREAM OF WIND CHILL ADVISORIES WILL MOST LIKELY CONTINUE BOTH TUESDAY AND WEDNESDAY NIGHT. LONG RANGE MODELS CONTINUE TO ADVERTISE THE COLD POOL OF AIR SITTING OVER CENTRAL CANADA INTO HUDSON BAY REGION DOWN INTO THE NORTH CENTRAL UNITED STATES. SURFACE HIGH REMAINS FROM NORTH DAKOTA INTO SASK. THUS FOR THE THURSDAY THROUGH SUNDAY PERIOD EXPECTING WELL BELOW NORMAL TEMPERATURES BUT DRY CONDITIONS. MAY BE A LITTLE LOW ON THURSDAY FEATURING RIDICULOUSLY COLD MAX TEMPS BUT LET RIDE FOR NOW. ADDED A COUPLE OF DEGREES TO WEEKEND TEMPS...IF ECMWF IS CORRECT IT WILL BE COLDER THOUGH AS IT ROTATES COLD POOL FROM NORTHERN MANITOBA THROUGH WINNIPEG INTO MINNESOTA. FORECAST STILL BARREN WITH RESPECT TO PRECIPITATION THROUGH SATURDAY WITH A SOUTH TRACKING SYSTEM OFFERING SCANT POPS ACROSS THE FAR SOUTHWEST BRIEFLY ON SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1135 PM CST SUN FEB 23 2014 VFR CONDS ACROSS AREA THROUGH 06Z TAF PERIOD...WITH EXCEPTION OF FAR. MAY SEE SOME MVFR CIGS AND LIGHT SNOW IN THE LATE AFTN TO EARLY EVENING HOURS TOMORROW. DID MENTION LIGHT SNOW AFT 22Z AS MODELS HAVE CONSISTENTLY BROUGHT PRECIP ALONG AND SOUTH OF I 94 CORRIDOR. HAVE MAINTAINED LOW VFR CIGS AT DVL AND GFK BUT REMOVED CIGS FROM TVF AND BJI AS SWATH OF CLOUDS SHOULD DROP SOUTH AS THEY DRIFT EAST. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WIND CHILL ADVISORY UNTIL 10 AM CST MONDAY FOR NDZ038-039-053. WIND CHILL ADVISORY UNTIL 10 AM CST MONDAY FOR NDZ006>008- 014>016-024-026>030-054. MN...WIND CHILL ADVISORY UNTIL 10 AM CST MONDAY FOR MNZ003-005-006- 008-009-013>017-022>024-027>032-040. WIND CHILL ADVISORY UNTIL 10 AM CST MONDAY FOR MNZ001-002-004- 007. && $$ UPDATE...SPEICHER SHORT TERM...ROGERS LONG TERM...ROGERS/WJB AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
930 PM CST TUE FEB 25 2014 .DISCUSSION... CURRENT FORECAST IS IN GOOD SHAPE. NO UPDATE IS PLANNED FOR THE OVERNIGHT HOURS. WILL WAIT FOR ALL OF THE 00Z MODELS TO ARRIVE BEFORE ANY SIGNIFICANT CHANGES ARE MADE TO OUR RAIN CHANCES...WINDS AND TEMPERATURES. COLD FRONT IS SLOWLY WORKING ITS WAY THROUGH SOUTHEAST TEXAS THIS EVENING...APPROACHING THE I-10 CORRIDOR AT AROUND 9 PM. AREAS OF RAIN WITH EMBEDDED SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS THE AREA...AND MODELS INDICATE THIS SHOULD CONTINUE OVERNIGHT AND ON INTO TOMORROW MORNING (SOME SPOTS WITH THE HEAVIER STORMS HAVE ALREADY RECEIVED 1 TO 2 INCHES). TEMPERATURES ARE IN THE LOW TO MID 50S BEHIND THE FRONT UP NORTH...AND EXPECT THIS COOLER AIR TO WORK ITS WAY TOWARD THE COAST OVERNIGHT. 42 && .PREV DISCUSSION... /ISSUED 609 PM CST TUE FEB 25 2014/ DISCUSSION... 00Z AVIATION DISCUSSION BELOW. AVIATION... THE SHORT TERM FORECAST...OR THROUGH THE EARLY WEDNESDAY MORNING HOURS...WILL BE FOR INTERMITTENT SHOWERS WITH A ISOLATED STORM AND STRENGTHENED NORTH WIND BEHIND AN EVENING COLD FRONTAL PASSAGE. THE MAIN IMPULSE DRIVING THIS ONGOING WIDELY SCATTERED -SHRA (ISO -TSRA) IS TRAVELING ACROSS NORTHERN TEXAS THIS EVENING WITH THE ONLY TRIGGERS LEFT OVER IN THIS HIGHLY-MOIST ENVIRONMENT FOR REPEAT PRECIPITATION BEING ANOTHER EASTERN PASSING SHORTWAVE RIPPLE WITHIN THE WESTERLY FLOW AND/OR THE ENHANCED POST-FRONTAL ISENTROPIC UPGLIDE AS SOUTHWESTERLY MID-UPPER FLOW RIDES UP AND OVER A PUMPED UP NORTH-NORTHEAST LOWER LEVEL WIND. BETTER UPPER DIFFULENCE BY TOMORROW AFTERNOON AS SE TX FALLS UNDER AN EXITING RRQ JET. CONSIDERING THE ABOVE ELEMENTS AND...EVEN WITH NWP MODELING NOT PROVIDING MUCH GUIDANCE UP TO NOW...STILL BELIEVE THAT ALL WILL COME IN-LINE FOR BETTER OVERALL (LIGHT) RAIN COVERAGE. PROBABLY NOT AN ALL-DAY RAIN EVENT...BUT GT 50% OF THE TIME THERE WILL BE THAT PASSING SHOWER...BRIEF MODERATE RAINFALL ASSOCIATED WITH STRONGER CELLS WEDNESDAY AFTERNOON...BUT THERE WILL ALSO BE LONGER PERIODS OF A JUST A LIGHT MIST AND/OR DRIZZLE ALONG WITH THOSE PESKY FLUCTUATING DECKS FROM IFR TO MVFR AND VICE VERSA. 31 PREV DISCUSSION... /ISSUED 333 PM CST TUE FEB 25 2014/ DISCUSSION... FRONT IS NOW PUSHING INTO NRN PORTIONS OF SE TX. SHOULD BE BETWEEN I-10 AND THE COAST AROUND MIDNIGHT AND OFF THE BEACHES BY 4AM (EFFECTIVELY ENDING SEA FOG ISSUES FOR A FEW DAYS). STARTING TO SEE SOME SCT PRECIP DEVELOP ACROSS S PARTS OF THE AREA AND EXPECT IT TO GRADUALLY INCREASE IN COVERAGE AHEAD OF, AND ESPECIALLY BEHIND, THE FRONT. HRRR MODEL AND TO A DEGREE NAM12 HAS DONE FAIRLY WELL WITH RAINFALL DEPICTION (OR LACK THEREOF) SO FAR TODAY AND SHORT TERM FCST WAS TRENDED THAT WAY. GFS/ECMWF HAVE BEEN HORRIBLY OVERDONE BOTH IN COVERAGE & AMOUNTS UP TO THIS TIME. PERIODS OF PRECIP WILL LIKELY CONTINUE THRU WED IN ASSOCIATION WITH H85 FRONT AND UPPER IMPULSES RIDING FURTHER OVERHEAD IN THE WRLY FLOW ALOFT. CONSIDERING STRONG CAA...CLOUDINESS AND PRECIP THE HIGHS FOR THE 24 HOUR PERIOD WILL OCCUR AROUND MIDNIGHT FOLLOWED BY FALLING AND/OR STEADY TEMPS IN THE 40S WED. RAIN SHOULD TAPER OFF WED EVENING. COOL WX CONTINUES THURS BUT ONSHORE WIND WILL BE RESUMING AS HIGH PRES MOVES EAST AND NEXT SHORTWAVE STARTS DIGGING SEWD DOWN THE 4-CORNERS AREA. THIS DISTURBANCE ISN`T AS IMPRESSIVE AS PREVIOUS DAYS AND DON`T ANTICIPATE MUCH OF AN IMPACT HERE AS IT MOVES ALONG THE RED RIVER FRIDAY...AS BEST ENERGY WILL BE WELL NORTH AND A CAP SHOULD BE IN PLACE. FURTHER LOWERED POPS. WARMING TREND CONTINUES THRU THE WEEKEND WITH ONSHORE FLOW IN PLACE. APPEARS THAT WE`LL PROBABLY HAVE ANOTHER COASTAL FOG EVENT BUT LOOKS LIKE MARDI GRAS PARADES SHOULD OTHERWISE BE DRY PRIOR TO MID TO LATE SUNDAY AFTN. NEXT STORM SYSTEM APPROACHES FROM THE WEST LATE IN THE WEEKEND AND KEPT 20-40% POPS IN PLACE SUN AFTN/NIGHT AHEAD OF THE NEXT FRONT THAT`LL BE MOVING THRU SUNDAY NIGHT OR MONDAY. KNOCKED TEMPS DOWN EARLY NEXT WEEK (MAYBE NOT ENOUGH) AS 1040+MB HIGH DROPS INTO THE PLAINS. 47 MARINE... SEA FOG WILL CONTINUE OVER THE GULF WATERS THIS AFTERNOON. AM EXPECTING THE FOG TO REDEVELOP AND BECOME DENSE OVER THE BAYS LATER THIS AFTERNOON AND EVENING. THE FOG WILL CLEAR OUT BETWEEN MIDNIGHT AND SUNRISE AS A COLD FRONT PUSHES THROUGH THE BAYS AND OFF THE COAST. THE MODELS HAVE BEEN FAIRLY CONSISTENT THE PAST FEW DAYS AND AM FAIRLY CONFIDENT ON THE TIMING. EXPECT THE FRONT TO MOVE THROUGH THE BAYS BY AROUND 3 AM AND THEN BEYOND 20 NM OFFSHORE BY 4 AM. THE 12Z MODEL RUN AND GUIDANCE FROM THIS MORNING FORECASTED SLIGHTLY HIGHER WINDS...INDICATING THAT SMALL CRAFT ADVISORIES ARE LIKELY FOR THE GULF WATERS AND MATAGORDA BAY. WOULD NOT BE SURPRISED IF WINDS INCREASE TO BETWEEN 20 AND 25 KNOTS FOR AT LEAST MOST OF THE LOWER PART OF GALVESTON BAY...ALSO. EXPECT THE NORTHEASTERLY WINDS TO DIMINISH WEDNESDAY NIGHT AND THURSDAY. ANOTHER FOG EVENT MAY DEVELOP BY LATE THIS WEEK AS ONSHORE REDEVELOPS. && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 43 43 33 57 42 / 70 60 20 10 10 HOUSTON (IAH) 49 49 36 59 43 / 70 70 30 10 10 GALVESTON (GLS) 54 54 42 55 53 / 70 60 40 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...DENSE FOG ADVISORY UNTIL 4 AM CST WEDNESDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY FROM 6 AM TO NOON CST WEDNESDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT SHOULD EXERCISE CAUTION WEDNESDAY AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM CST WEDNESDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT SHOULD EXERCISE CAUTION FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO MIDNIGHT CST WEDNESDAY NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM... WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. SMALL CRAFT SHOULD EXERCISE CAUTION LATE WEDNESDAY NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...42 AVIATION/MARINE...31
AREA FORECAST DISCUSSION...UPDATED
NWS HOUSTON/GALVESTON TX
609 PM CST TUE FEB 25 2014 .DISCUSSION... 00Z AVIATION DISCUSSION BELOW. && .AVIATION... THE SHORT TERM FORECAST...OR THROUGH THE EARLY WEDNESDAY MORNING HOURS...WILL BE FOR INTERMITTENT SHOWERS WITH A ISOLATED STORM AND STRENGTHENED NORTH WIND BEHIND AN EVENING COLD FRONTAL PASSAGE. THE MAIN IMPULSE DRIVING THIS ONGOING WIDELY SCATTERED -SHRA (ISO -TSRA) IS TRAVELING ACROSS NORTHERN TEXAS THIS EVENING WITH THE ONLY TRIGGERS LEFT OVER IN THIS HIGHLY-MOIST ENVIRONMENT FOR REPEAT PRECIPITATION BEING ANOTHER EASTERN PASSING SHORTWAVE RIPPLE WITHIN THE WESTERLY FLOW AND/OR THE ENHANCED POST-FRONTAL ISENTROPIC UPGLIDE AS SOUTHWESTERLY MID-UPPER FLOW RIDES UP AND OVER A PUMPED UP NORTH-NORTHEAST LOWER LEVEL WIND. BETTER UPPER DIFFULENCE BY TOMORROW AFTERNOON AS SE TX FALLS UNDER AN EXITING RRQ JET. CONSIDERING THE ABOVE ELEMENTS AND...EVEN WITH NWP MODELING NOT PROVIDING MUCH GUIDANCE UP TO NOW...STILL BELIEVE THAT ALL WILL COME IN-LINE FOR BETTER OVERALL (LIGHT) RAIN COVERAGE. PROBABLY NOT AN ALL-DAY RAIN EVENT...BUT GT 50% OF THE TIME THERE WILL BE THAT PASSING SHOWER...BRIEF MODERATE RAINFALL ASSOCIATED WITH STRONGER CELLS WEDNESDAY AFTERNOON...BUT THERE WILL ALSO BE LONGER PERIODS OF A JUST A LIGHT MIST AND/OR DRIZZLE ALONG WITH THOSE PESKY FLUCTUATING DECKS FROM IFR TO MVFR AND VICE VERSA. 31 && .PREV DISCUSSION... /ISSUED 333 PM CST TUE FEB 25 2014/ DISCUSSION... FRONT IS NOW PUSHING INTO NRN PORTIONS OF SE TX. SHOULD BE BETWEEN I-10 AND THE COAST AROUND MIDNIGHT AND OFF THE BEACHES BY 4AM (EFFECTIVELY ENDING SEA FOG ISSUES FOR A FEW DAYS). STARTING TO SEE SOME SCT PRECIP DEVELOP ACROSS S PARTS OF THE AREA AND EXPECT IT TO GRADUALLY INCREASE IN COVERAGE AHEAD OF, AND ESPECIALLY BEHIND, THE FRONT. HRRR MODEL AND TO A DEGREE NAM12 HAS DONE FAIRLY WELL WITH RAINFALL DEPICTION (OR LACK THEREOF) SO FAR TODAY AND SHORT TERM FCST WAS TRENDED THAT WAY. GFS/ECMWF HAVE BEEN HORRIBLY OVERDONE BOTH IN COVERAGE & AMOUNTS UP TO THIS TIME. PERIODS OF PRECIP WILL LIKELY CONTINUE THRU WED IN ASSOCIATION WITH H85 FRONT AND UPPER IMPULSES RIDING FURTHER OVERHEAD IN THE WRLY FLOW ALOFT. CONSIDERING STRONG CAA...CLOUDINESS AND PRECIP THE HIGHS FOR THE 24 HOUR PERIOD WILL OCCUR AROUND MIDNIGHT FOLLOWED BY FALLING AND/OR STEADY TEMPS IN THE 40S WED. RAIN SHOULD TAPER OFF WED EVENING. COOL WX CONTINUES THURS BUT ONSHORE WIND WILL BE RESUMING AS HIGH PRES MOVES EAST AND NEXT SHORTWAVE STARTS DIGGING SEWD DOWN THE 4-CORNERS AREA. THIS DISTURBANCE ISN`T AS IMPRESSIVE AS PREVIOUS DAYS AND DON`T ANTICIPATE MUCH OF AN IMPACT HERE AS IT MOVES ALONG THE RED RIVER FRIDAY...AS BEST ENERGY WILL BE WELL NORTH AND A CAP SHOULD BE IN PLACE. FURTHER LOWERED POPS. WARMING TREND CONTINUES THRU THE WEEKEND WITH ONSHORE FLOW IN PLACE. APPEARS THAT WE`LL PROBABLY HAVE ANOTHER COASTAL FOG EVENT BUT LOOKS LIKE MARDI GRAS PARADES SHOULD OTHERWISE BE DRY PRIOR TO MID TO LATE SUNDAY AFTN. NEXT STORM SYSTEM APPROACHES FROM THE WEST LATE IN THE WEEKEND AND KEPT 20-40% POPS IN PLACE SUN AFTN/NIGHT AHEAD OF THE NEXT FRONT THAT`LL BE MOVING THRU SUNDAY NIGHT OR MONDAY. KNOCKED TEMPS DOWN EARLY NEXT WEEK (MAYBE NOT ENOUGH) AS 1040+MB HIGH DROPS INTO THE PLAINS. 47 && MARINE... SEA FOG WILL CONTINUE OVER THE GULF WATERS THIS AFTERNOON. AM EXPECTING THE FOG TO REDEVELOP AND BECOME DENSE OVER THE BAYS LATER THIS AFTERNOON AND EVENING. THE FOG WILL CLEAR OUT BETWEEN MIDNIGHT AND SUNRISE AS A COLD FRONT PUSHES THROUGH THE BAYS AND OFF THE COAST. THE MODELS HAVE BEEN FAIRLY CONSISTENT THE PAST FEW DAYS AND AM FAIRLY CONFIDENT ON THE TIMING. EXPECT THE FRONT TO MOVE THROUGH THE BAYS BY AROUND 3 AM AND THEN BEYOND 20 NM OFFSHORE BY 4 AM. THE 12Z MODEL RUN AND GUIDANCE FROM THIS MORNING FORECASTED SLIGHTLY HIGHER WINDS...INDICATING THAT SMALL CRAFT ADVISORIES ARE LIKELY FOR THE GULF WATERS AND MATAGORDA BAY. WOULD NOT BE SURPRISED IF WINDS INCREASE TO BETWEEN 20 AND 25 KNOTS FOR AT LEAST MOST OF THE LOWER PART OF GALVESTON BAY...ALSO. EXPECT THE NORTHEASTERLY WINDS TO DIMINISH WEDNESDAY NIGHT AND THURSDAY. ANOTHER FOG EVENT MAY DEVELOP BY LATE THIS WEEK AS ONSHORE REDEVELOPS. 40 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 43 43 33 57 42 / 70 60 20 10 10 HOUSTON (IAH) 49 49 36 59 43 / 70 70 30 10 10 GALVESTON (GLS) 54 54 42 55 53 / 70 60 40 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...DENSE FOG ADVISORY UNTIL 4 AM CST WEDNESDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...42 AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1023 PM PST Sun Feb 23 2014 .SYNOPSIS... Periods of snow will continue tonight. Snow showers will linger through Monday, mainly over the Cascades, Blue Mountains, and the Idaho Panhandle. A subtle warming trend is expected Tuesday through Thursday with temperatures near average for the second half of the work week. Next weekend has the potential to be colder with a chance of more snow. && .DISCUSSION... Ended some of the winter weather advisories, decreased pops in those same areas, and slightly cooled forecast low temperatures tonight with a late evening update. Radar and HRRR runs suggest the back edge of the exiting swath of snowfall is slowly moving to the southeast and exited those area to the north. Some light precipitation may still fall on those locations but since no further significant accumulations were expected tonight those highlights were ended. Locations to the south and east near the Palouse and down to the Camas Prairie are still susceptible to the northwest to southeast trajectory of exit associated with this disturbances so those advisories along with the winter storm warning for the Idaho Central Panhandle Mountains have been maintained with some slight modification to the accumulation amounts and more wording to reference the very slick road conditions when pavement temperatures dropped below freezing near and shortly after sundown today. Additionally some fog was added to the forecast earlier on, primarily as it appeared in proximity to the more intense snow of this evening but right now it seems to have gone and mostly low stratus has taken its place. /Pelatti && .AVIATION... 06Z TAFS: Slow exit to the southeast of a weather disturbance bringing mostly snow to majority of aviation areas allows for primarily IFR ceilings to linger as most of the intense snowfall has already occurred and/or moving out of the area to the southeast. Fog has accompanied the snow at times. A weak frontal may very well allow snow to intensify near the Palouse early Monday morning ahead of yet another weather system coming up from the south which will allow a good part of the time interval after 03Z Tuesday down south to become wet as well with more rain/snow. /Pelatti && .PRELIMINARY POINT TEMPS/POPS... Spokane 20 31 18 32 19 39 / 20 10 10 0 0 0 Coeur d`Alene 18 30 16 33 14 38 / 40 10 10 0 0 0 Pullman 27 33 25 39 25 42 / 80 50 40 20 10 10 Lewiston 33 40 29 43 29 47 / 90 40 50 20 10 10 Colville 16 32 16 37 12 40 / 20 10 10 0 0 0 Sandpoint 14 28 14 31 11 35 / 20 10 10 0 0 0 Kellogg 16 29 17 34 13 39 / 100 40 30 10 0 0 Moses Lake 27 38 26 41 23 43 / 20 10 20 10 10 0 Wenatchee 27 35 25 38 24 40 / 50 40 30 10 10 10 Omak 21 33 22 36 18 38 / 20 20 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory until 10 AM PST Monday for Idaho Palouse. Winter Storm Warning until 10 AM PST Monday for Central Panhandle Mountains. Winter Weather Advisory until 10 AM PST Monday for Lewis and Southern Nez Perce Counties. WA...Winter Weather Advisory until 4 AM PST Monday for East Slopes Northern Cascades. Winter Weather Advisory until 10 AM PST Monday for Washington Palouse. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1131 AM CST MON FEB 24 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CST MON FEB 24 2014 ...CURRENTLY AS OF 09Z... WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING ALONG THE U.S. WEST COAST NORTHWARD THROUGH ALASKA...WHILE TROUGHING DOMINATED FROM THE NORTH POLE SOUTHWARD THROUGH MUCH OF CANADA AND THE NORTHERN TIER OF THE U.S.. WITHIN THIS TROUGHING...THERE ARE 3 IMPORTANT SHORTWAVE TROUGHS OF NOTE FOR THE FORECAST... 1. OVER SOUTHERN SASKATCHEWAN INTO NORTHWEST MONTANA...EXPECTED TO BRING THE SNOW LATE TODAY INTO TONIGHT. DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE HAS SUPPORTED LIGHT SNOW ACROSS MUCH OF MONTANA SOUTHEAST INTO NEBRASKA. 2. ALONG THE NUNAVUT/NORTHWEST TERRITORIES BORDER IN CANADA... EXPECTED TO BRING THE ARCTIC COLD SHOT TO THE AREA TUESDAY NIGHT. IN ITS WAKE SURFACE TEMPERATURES RANGE FROM A BITTER 20 TO 30 BELOW ZERO. 3. RIGHT NEAR THE NORTH POLE...SPECIFICALLY 84 N / 130 W...EXPECTED TO BRING THE ARCTIC AIR FOR THURSDAY INTO THE WEEKEND. IN ITS WAKE... 925MB TEMPS RANGE FROM -28 TO -34C PER GFS ANALYSIS. OVER THE FORECAST AREA...SKIES REMAIN CLEAR DUE TO PLENTY OF DRY AIR AS SEEN ON THE 00Z MPX SOUNDING. SOME CIRRUS IS BEGINNING TO ENCROACH FROM THE WEST...THOUGH. TEMPERATURES HAVE SLOWLY COOLED THROUGH THE NIGHT RESULTING FROM A WESTERLY BREEZE...WITH READINGS IN THE LOWER SINGLE DIGITS. ... FORECAST ... MODELS ARE IN GOOD AGREEMENT MARCHING THE FIRST SHORTWAVE TROUGH INTO THE EASTERN DAKOTAS BY 00Z...OVER THE FORECAST AREA BY 06Z AND INTO LOWER MICHIGAN BY 12Z TUE. 275-280K ISENTROPIC LIFT PROGS SUGGEST THAT TO GET THE SNOW OVER MONTANA AND NEBRASKA INTO THE FORECAST AREA...WE HAVE TO WAIT FOR THE SHORTWAVE TROUGH TO ARRIVE. THIS IS WHY MODELS SLOWED DOWN OVER THE PAST FEW DAYS OF BRINGING SNOW TO THE AREA. THE BEST LIFT...ALBEIT WEAK...IS PROGGED OVER THE SOUTHWESTERN HALF OF THE FORECAST AREA BETWEEN 01-06Z...THEN SHIFTS TO FAR SOUTHWEST WI BETWEEN 06-09Z BEFORE EXITING. PRECIPITATION CHANCES HAVE BEEN ADJUSTED TO FIT THE TIMING OF THE LIFT SIGNAL. STILL DOES NOT LOOK LIKE THERE WILL BE MUCH SNOW GIVEN THE WEAK NATURE OF THE LIFT...PRECIPITABLE WATER ONLY 0.1-0.2 OF AN INCH...AND THE SNOW RUNNING INTO THE DRY AIRMASS CURRENTLY IN PLACE. ANY LIFT TOO IS MOSTLY ABOVE THE DENDRITIC GROWTH ZONE. PREVIOUS FORECAST AMOUNTS OF LESS THAN 1 INCH SEEM REASONABLE. REGARDING TEMPERATURES. 925MB READINGS AT 18Z TODAY ARE SIMILAR TO YESTERDAY AT 18Z...BETWEEN -13 AND -16C. ONLY DIFFERENCES BETWEEN TODAY AND YESTERDAY IS MORE CLOUD COVER AND STARTING OFF COLDER... WHICH SHOULD KEEP HIGHS A LITTLE COOLER. IN THE WAKE OF THE SHORTWAVE TROUGH PASSAGE TONIGHT...925MB TEMPS COOL TO -14 TO -19C. A NORTHWEST BREEZE COMBINED WITH CLOUDS SHOULD HELP TO HOLD LOWS UP SOMEWHAT...BUT READINGS SHOULD FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO THROUGH ADVECTION...COLDEST OVER THE NORTHWEST HALF OF THE FORECAST AREA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 300 AM CST MON FEB 24 2014 THE BIG IMPACT STORY HERE IS THE COLD... SHORTWAVE TROUGH CURRENTLY OVER THE NUNAVUT/NORTHWEST TERRITORIES REGION IS PROGGED TO DROP THROUGH THE FORECAST AREA LATE TUESDAY...USHERING IN THE FIRST SURGE OF BITTER COLD ARCTIC AIR. TROUGH SHOULD GO THROUGH PRECIP FREE WITH JUST SOME CLOUDS. 925MB TEMPS PLUMMET TO -21 TO -24C BY 06Z WEDNESDAY...SENDING SURFACE TEMPERATURES DOWN BELOW ZERO. WITH THE COLD AIR FIRMLY ENTRENCHED FOR 06-12Z...TEMPERATURES SHOULD IN MOST LOCATIONS DIP INTO TEENS BELOW ZERO. MOS GUIDANCE WIND FORECASTS SUGGEST THE TYPICAL COLD SPOTS COULD DECOUPLE...THUS HAVE THEM APPROACHING 20 BELOW. A WIND CHILL ADVISORY IS A GIVEN FOR TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BREAK IN THE COLD AIR COMES WEDNESDAY AFTERNOON AS WESTERLY WINDS INCREASE AND PULL IN SOME DOWNSLOPED AIR OFF THE ROCKIES. THIS INCREASE IS A RESULT OF THE NEXT SHORTWAVE TROUGH NEAR THE NORTH POLE DROPPING INTO THE MN ARROWHEAD. 925MB WINDS APPROACH 45-50 KT AT 00Z THURSDAY WEST OF THE MISSISSIPPI RIVER...BRINGING UP CONCERN OF A POSSIBLE WIND ADVISORY. HOWEVER...A STRONG INVERSION LOOKS TO DEVELOP TO PRECLUDE MIXING THOSE HIGHER WINDS DOWN. IT STILL WILL BE BRISK...THOUGH...AND STRONG ENOUGH TO RESULT IN SOME BLOWING AND DRIFTING OF SNOW IN OPEN AREAS. NEXT ARCTIC COLD SHOT WHICH IS MUCH MORE IMPRESSIVE COMES IN LATE WEDNESDAY NIGHT. THE AFOREMENTIONED NORTH POLE SHORTWAVE CROSSES UPPER MICHIGAN WEDNESDAY NIGHT...DRAGGING AN ARCTIC COLD FRONT THROUGH THE FORECAST AREA. A STRONG PRESSURE RISE IS PROGGED BEHIND THIS FRONT WHICH SHOULD RESULT IN A PERIOD OF BRISK NORTHWEST WINDS. THEN 925MB TEMPS PLUMMET TO -23 TO -27C AT 12Z THURSDAY. DID NOT GO AS COLD AS THESE WOULD SUGGEST GIVEN THE LATE ARRIVAL OF THE COLD AIR AND PLENTY OF WIND. STILL...THE WIND CHILLS ARE PLENTY LOW ENOUGH FOR AN ADVISORY. THURSDAY AND THURSDAY NIGHT LOOK DOWNRIGHT COLD. 850MB TEMP ANOMALIES ARE PROGGED BETWEEN 2.5-3 STANDARD DEVIATIONS BELOW NORMAL...SUGGESTING RECORD TERRITORY. IN ADDITION...HIGH PRESSURE SETTLES OVERHEAD THURSDAY NIGHT...SETTING UP POTENTIAL FOR TEMPERATURES TO TANK. ONLY CAVEAT WILL BE SOME INCREASING MID/HIGH CLOUDS LATER THURSDAY NIGHT. SOME WISCONSIN COLD SPOTS COULD DIP TO 30 BELOW OR COLDER...AS INDICATED BY THE MEX GUIDANCE. FOR FRIDAY THROUGH MONDAY...THE FORECAST AREA WILL BE IN-BETWEEN ARCTIC COLD UPPER TROUGHING ENCOMPASSING MUCH OF SOUTHERN CANADA AND SHORTWAVE TROUGHS TRAVERSING THE SOUTHERN 2/3 OF THE U.S.. AT THE SAME TIME AT THE SURFACE...ARCTIC HIGH PRESSURE SHOULD BE IN PLACE FOR MUCH OF THE TIME. ONE SHORTWAVE MAY BRING SOME LIGHT SNOW TO LOCATIONS SOUTH OF I-90 ON FRIDAY...IF IT CAN MAKE IT THROUGH THE DRY AIR. ONLY KEPT 20 PERCENT CHANCES IN FOR THIS TIME PERIOD. SAME HOLDS TRUE FOR ANOTHER SHORTWAVE TROUGH GOING BY SATURDAY NIGHT INTO SUNDAY...THOUGH THE TRACK IS A BIT FARTHER NORTH SO CHANCES ARE A LITTLE HIGHER. TEMPERATURES WILL STAY WELL BELOW NORMAL BEING UNDER THE INFLUENCE OF THE ARCTIC SURFACE HIGH...THOUGH SOME GRADUAL MODERATION SHOULD TAKE PLACE AS THE EARLY MARCH SUN WORKS ON THE AIR. MORE WIND CHILL ADVISORIES ARE LIKELY...THOUGH...ESPECIALLY FRIDAY NIGHT INTO SATURDAY MORNING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1131 AM CST MON FEB 24 2014 WEATHER SYSTEM TO TRACK SOUTHWEST OF THE TAF SITES THIS EVENING...AND WILL LIKELY SPREAD LIGHT SNOW ACROSS KRST/KLSE AS IT PASSES. TIMING WISE...LOOK FOR THE HEART OF THE FALLING SNOW TO BE CENTERED AROUND 03Z...AND SHOULD ONLY LAST 2-4 HOURS AT EITHER LOCATION. IFR VISIBILITIES EXPECTED AT KRST...WHERE THE BETTER FORCING AND SATURATION WILL EXIST. AT KLSE...SIGNIFICANT AMOUNT OF DRY AIR IN PLACE COUPLED WITH WEAKER FORCING SHOULD LIMIT RESTRICTIONS. CEILINGS LIKELY TO REMAIN AT OR ABOVE 2000 FT THROUGH THE PERIOD. ONCE THE SYSTEM DEPARTS OVERNIGHT...LINGERING MOISTURE TRAPPED UNDER A LOW LEVEL INVERSION WILL KEEP CLOUDS IN PLACE THROUGH 12Z. FINALLY...PUSH OF DRIER TUESDAY MORNING WILL SCATTER REMAINING CLOUDS OUT AND MIXING UP TO 925 MB SHOULD MAKE FOR SOME LATE MORNING / AFTERNOON GUSTS UP TO 20-22 KTS AT KRST. && .CLIMATE... ISSUED AT 300 AM CST MON FEB 24 2014 GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS HOW FEBRUARY AND THE WINTER OVERALL WOULD STACK UP COMPARED TO RECORDS BASED ON THE CURRENT FORECAST... ...FOR THE MONTH OF FEBRUARY... LA CROSSE... 9.3 AVERAGE TEMPERATURE...3RD COLDEST COLDER FEBRUARYS... 1873... 3.9 1936... 4.3 ROCHESTER... 6.7 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1936... 0.5 1979... 5.7 1917... 6.0 ...FOR THE WINTER...DECEMBER THROUGH FEBRUARY... LA CROSSE... 11.5 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1872-1873... 8.4 1874-1875... 10.5 1977-1978... 11.4 1935-1936... 11.4 ROCHESTER... 8.8 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1978-1979... 5.6 1886-1887... 5.9 1935-1936... 8.1 1977-1978... 8.7 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION...ZT CLIMATE......AJ/RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 AM CST MON FEB 24 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CST MON FEB 24 2014 ...CURRENTLY AS OF 09Z... WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING ALONG THE U.S. WEST COAST NORTHWARD THROUGH ALASKA...WHILE TROUGHING DOMINATED FROM THE NORTH POLE SOUTHWARD THROUGH MUCH OF CANADA AND THE NORTHERN TIER OF THE U.S.. WITHIN THIS TROUGHING...THERE ARE 3 IMPORTANT SHORTWAVE TROUGHS OF NOTE FOR THE FORECAST... 1. OVER SOUTHERN SASKATCHEWAN INTO NORTHWEST MONTANA...EXPECTED TO BRING THE SNOW LATE TODAY INTO TONIGHT. DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE HAS SUPPORTED LIGHT SNOW ACROSS MUCH OF MONTANA SOUTHEAST INTO NEBRASKA. 2. ALONG THE NUNAVUT/NORTHWEST TERRITORIES BORDER IN CANADA... EXPECTED TO BRING THE ARCTIC COLD SHOT TO THE AREA TUESDAY NIGHT. IN ITS WAKE SURFACE TEMPERATURES RANGE FROM A BITTER 20 TO 30 BELOW ZERO. 3. RIGHT NEAR THE NORTH POLE...SPECIFICALLY 84 N / 130 W...EXPECTED TO BRING THE ARCTIC AIR FOR THURSDAY INTO THE WEEKEND. IN ITS WAKE... 925MB TEMPS RANGE FROM -28 TO -34C PER GFS ANALYSIS. OVER THE FORECAST AREA...SKIES REMAIN CLEAR DUE TO PLENTY OF DRY AIR AS SEEN ON THE 00Z MPX SOUNDING. SOME CIRRUS IS BEGINNING TO ENCROACH FROM THE WEST...THOUGH. TEMPERATURES HAVE SLOWLY COOLED THROUGH THE NIGHT RESULTING FROM A WESTERLY BREEZE...WITH READINGS IN THE LOWER SINGLE DIGITS. ... FORECAST ... MODELS ARE IN GOOD AGREEMENT MARCHING THE FIRST SHORTWAVE TROUGH INTO THE EASTERN DAKOTAS BY 00Z...OVER THE FORECAST AREA BY 06Z AND INTO LOWER MICHIGAN BY 12Z TUE. 275-280K ISENTROPIC LIFT PROGS SUGGEST THAT TO GET THE SNOW OVER MONTANA AND NEBRASKA INTO THE FORECAST AREA...WE HAVE TO WAIT FOR THE SHORTWAVE TROUGH TO ARRIVE. THIS IS WHY MODELS SLOWED DOWN OVER THE PAST FEW DAYS OF BRINGING SNOW TO THE AREA. THE BEST LIFT...ALBEIT WEAK...IS PROGGED OVER THE SOUTHWESTERN HALF OF THE FORECAST AREA BETWEEN 01-06Z...THEN SHIFTS TO FAR SOUTHWEST WI BETWEEN 06-09Z BEFORE EXITING. PRECIPITATION CHANCES HAVE BEEN ADJUSTED TO FIT THE TIMING OF THE LIFT SIGNAL. STILL DOES NOT LOOK LIKE THERE WILL BE MUCH SNOW GIVEN THE WEAK NATURE OF THE LIFT...PRECIPITABLE WATER ONLY 0.1-0.2 OF AN INCH...AND THE SNOW RUNNING INTO THE DRY AIRMASS CURRENTLY IN PLACE. ANY LIFT TOO IS MOSTLY ABOVE THE DENDRITIC GROWTH ZONE. PREVIOUS FORECAST AMOUNTS OF LESS THAN 1 INCH SEEM REASONABLE. REGARDING TEMPERATURES. 925MB READINGS AT 18Z TODAY ARE SIMILAR TO YESTERDAY AT 18Z...BETWEEN -13 AND -16C. ONLY DIFFERENCES BETWEEN TODAY AND YESTERDAY IS MORE CLOUD COVER AND STARTING OFF COLDER... WHICH SHOULD KEEP HIGHS A LITTLE COOLER. IN THE WAKE OF THE SHORTWAVE TROUGH PASSAGE TONIGHT...925MB TEMPS COOL TO -14 TO -19C. A NORTHWEST BREEZE COMBINED WITH CLOUDS SHOULD HELP TO HOLD LOWS UP SOMEWHAT...BUT READINGS SHOULD FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO THROUGH ADVECTION...COLDEST OVER THE NORTHWEST HALF OF THE FORECAST AREA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 300 AM CST MON FEB 24 2014 THE BIG IMPACT STORY HERE IS THE COLD... SHORTWAVE TROUGH CURRENTLY OVER THE NUNAVUT/NORTHWEST TERRITORIES REGION IS PROGGED TO DROP THROUGH THE FORECAST AREA LATE TUESDAY...USHERING IN THE FIRST SURGE OF BITTER COLD ARCTIC AIR. TROUGH SHOULD GO THROUGH PRECIP FREE WITH JUST SOME CLOUDS. 925MB TEMPS PLUMMET TO -21 TO -24C BY 06Z WEDNESDAY...SENDING SURFACE TEMPERATURES DOWN BELOW ZERO. WITH THE COLD AIR FIRMLY ENTRENCHED FOR 06-12Z...TEMPERATURES SHOULD IN MOST LOCATIONS DIP INTO TEENS BELOW ZERO. MOS GUIDANCE WIND FORECASTS SUGGEST THE TYPICAL COLD SPOTS COULD DECOUPLE...THUS HAVE THEM APPROACHING 20 BELOW. A WIND CHILL ADVISORY IS A GIVEN FOR TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BREAK IN THE COLD AIR COMES WEDNESDAY AFTERNOON AS WESTERLY WINDS INCREASE AND PULL IN SOME DOWNSLOPED AIR OFF THE ROCKIES. THIS INCREASE IS A RESULT OF THE NEXT SHORTWAVE TROUGH NEAR THE NORTH POLE DROPPING INTO THE MN ARROWHEAD. 925MB WINDS APPROACH 45-50 KT AT 00Z THURSDAY WEST OF THE MISSISSIPPI RIVER...BRINGING UP CONCERN OF A POSSIBLE WIND ADVISORY. HOWEVER...A STRONG INVERSION LOOKS TO DEVELOP TO PRECLUDE MIXING THOSE HIGHER WINDS DOWN. IT STILL WILL BE BRISK...THOUGH...AND STRONG ENOUGH TO RESULT IN SOME BLOWING AND DRIFTING OF SNOW IN OPEN AREAS. NEXT ARCTIC COLD SHOT WHICH IS MUCH MORE IMPRESSIVE COMES IN LATE WEDNESDAY NIGHT. THE AFOREMENTIONED NORTH POLE SHORTWAVE CROSSES UPPER MICHIGAN WEDNESDAY NIGHT...DRAGGING AN ARCTIC COLD FRONT THROUGH THE FORECAST AREA. A STRONG PRESSURE RISE IS PROGGED BEHIND THIS FRONT WHICH SHOULD RESULT IN A PERIOD OF BRISK NORTHWEST WINDS. THEN 925MB TEMPS PLUMMET TO -23 TO -27C AT 12Z THURSDAY. DID NOT GO AS COLD AS THESE WOULD SUGGEST GIVEN THE LATE ARRIVAL OF THE COLD AIR AND PLENTY OF WIND. STILL...THE WIND CHILLS ARE PLENTY LOW ENOUGH FOR AN ADVISORY. THURSDAY AND THURSDAY NIGHT LOOK DOWNRIGHT COLD. 850MB TEMP ANOMALIES ARE PROGGED BETWEEN 2.5-3 STANDARD DEVIATIONS BELOW NORMAL...SUGGESTING RECORD TERRITORY. IN ADDITION...HIGH PRESSURE SETTLES OVERHEAD THURSDAY NIGHT...SETTING UP POTENTIAL FOR TEMPERATURES TO TANK. ONLY CAVEAT WILL BE SOME INCREASING MID/HIGH CLOUDS LATER THURSDAY NIGHT. SOME WISCONSIN COLD SPOTS COULD DIP TO 30 BELOW OR COLDER...AS INDICATED BY THE MEX GUIDANCE. FOR FRIDAY THROUGH MONDAY...THE FORECAST AREA WILL BE IN-BETWEEN ARCTIC COLD UPPER TROUGHING ENCOMPASSING MUCH OF SOUTHERN CANADA AND SHORTWAVE TROUGHS TRAVERSING THE SOUTHERN 2/3 OF THE U.S.. AT THE SAME TIME AT THE SURFACE...ARCTIC HIGH PRESSURE SHOULD BE IN PLACE FOR MUCH OF THE TIME. ONE SHORTWAVE MAY BRING SOME LIGHT SNOW TO LOCATIONS SOUTH OF I-90 ON FRIDAY...IF IT CAN MAKE IT THROUGH THE DRY AIR. ONLY KEPT 20 PERCENT CHANCES IN FOR THIS TIME PERIOD. SAME HOLDS TRUE FOR ANOTHER SHORTWAVE TROUGH GOING BY SATURDAY NIGHT INTO SUNDAY...THOUGH THE TRACK IS A BIT FARTHER NORTH SO CHANCES ARE A LITTLE HIGHER. TEMPERATURES WILL STAY WELL BELOW NORMAL BEING UNDER THE INFLUENCE OF THE ARCTIC SURFACE HIGH...THOUGH SOME GRADUAL MODERATION SHOULD TAKE PLACE AS THE EARLY MARCH SUN WORKS ON THE AIR. MORE WIND CHILL ADVISORIES ARE LIKELY...THOUGH...ESPECIALLY FRIDAY NIGHT INTO SATURDAY MORNING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 605 AM CST MON FEB 24 2014 VFR CONDITIONS WILL CONTINUE TODAY AS COLD...DRY CANADIAN HIGH PRESSURE REMAINS OVER THE AREA. A SHORTWAVE TROUGH DROPPING ACROSS THE DAKOTAS TODAY WILL SPREAD INCREASING/LOWERING CLOUDS INTO THE AREA LATE THIS AFTERNOON BUT CIGS WILL REMAIN AOA 10K FT. THE TROUGH WILL SLIDE ACROSS THE AREA THIS EVENING. LIFT WITH THIS FEATURE WILL BE ON THE WEAK SIDE AND THE QUESTION REMAINS WILL THE LIFT BE ENOUGH TO OVERCOME THE DRIER LOW LEVEL AND PRODUCE SOME -SN AT THE TAF SITES. MODEL CONSENSUS HAS THE LIFT OVERCOMING THE DRY AIR AT KRST WITH A PERIOD OF MVFR/IFR CIGS/VSBYS IN -SN AS THE TROUGH MOVES BY. KLSE REMAINS ON THE EDGE OF WHERE LIFT APPEARS TO BE ENOUGH TO OVERCOME THE DRY AIR AND ONLY INCLUDED A PERIOD OF P6SM -SN AT KLSE. MODEL SOUNDINGS SHOWING SOME MOISTURE/SATURATION TO LINGER ACROSS THE AREA LATER TONIGHT...TRAPPED UNDER AN INVERSION NEAR 925MB. CARRIED BKN CIGS IN THE 2K-3K RANGE AT THE TAF SITES AFTER THE -SN MOVES OUT. && .CLIMATE... ISSUED AT 300 AM CST MON FEB 24 2014 GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS HOW FEBRUARY AND THE WINTER OVERALL WOULD STACK UP COMPARED TO RECORDS BASED ON THE CURRENT FORECAST... ...FOR THE MONTH OF FEBRUARY... LA CROSSE... 9.3 AVERAGE TEMPERATURE...3RD COLDEST COLDER FEBRUARYS... 1873... 3.9 1936... 4.3 ROCHESTER... 6.7 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1936... 0.5 1979... 5.7 1917... 6.0 ...FOR THE WINTER...DECEMBER THROUGH FEBRUARY... LA CROSSE... 11.5 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1872-1873... 8.4 1874-1875... 10.5 1977-1978... 11.4 1935-1936... 11.4 ROCHESTER... 8.8 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1978-1979... 5.6 1886-1887... 5.9 1935-1936... 8.1 1977-1978... 8.7 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RRS CLIMATE......AJ/RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
300 AM CST MON FEB 24 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CST MON FEB 24 2014 ...CURRENTLY AS OF 09Z... WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING ALONG THE U.S. WEST COAST NORTHWARD THROUGH ALASKA...WHILE TROUGHING DOMINATED FROM THE NORTH POLE SOUTHWARD THROUGH MUCH OF CANADA AND THE NORTHERN TIER OF THE U.S.. WITHIN THIS TROUGHING...THERE ARE 3 IMPORTANT SHORTWAVE TROUGHS OF NOTE FOR THE FORECAST... 1. OVER SOUTHERN SASKATCHEWAN INTO NORTHWEST MONTANA...EXPECTED TO BRING THE SNOW LATE TODAY INTO TONIGHT. DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE HAS SUPPORTED LIGHT SNOW ACROSS MUCH OF MONTANA SOUTHEAST INTO NEBRASKA. 2. ALONG THE NUNAVUT/NORTHWEST TERRITORIES BORDER IN CANADA... EXPECTED TO BRING THE ARCTIC COLD SHOT TO THE AREA TUESDAY NIGHT. IN ITS WAKE SURFACE TEMPERATURES RANGE FROM A BITTER 20 TO 30 BELOW ZERO. 3. RIGHT NEAR THE NORTH POLE...SPECIFICALLY 84 N / 130 W...EXPECTED TO BRING THE ARCTIC AIR FOR THURSDAY INTO THE WEEKEND. IN ITS WAKE... 925MB TEMPS RANGE FROM -28 TO -34C PER GFS ANALYSIS. OVER THE FORECAST AREA...SKIES REMAIN CLEAR DUE TO PLENTY OF DRY AIR AS SEEN ON THE 00Z MPX SOUNDING. SOME CIRRUS IS BEGINNING TO ENCROACH FROM THE WEST...THOUGH. TEMPERATURES HAVE SLOWLY COOLED THROUGH THE NIGHT RESULTING FROM A WESTERLY BREEZE...WITH READINGS IN THE LOWER SINGLE DIGITS. ... FORECAST ... MODELS ARE IN GOOD AGREEMENT MARCHING THE FIRST SHORTWAVE TROUGH INTO THE EASTERN DAKOTAS BY 00Z...OVER THE FORECAST AREA BY 06Z AND INTO LOWER MICHIGAN BY 12Z TUE. 275-280K ISENTROPIC LIFT PROGS SUGGEST THAT TO GET THE SNOW OVER MONTANA AND NEBRASKA INTO THE FORECAST AREA...WE HAVE TO WAIT FOR THE SHORTWAVE TROUGH TO ARRIVE. THIS IS WHY MODELS SLOWED DOWN OVER THE PAST FEW DAYS OF BRINGING SNOW TO THE AREA. THE BEST LIFT...ALBEIT WEAK...IS PROGGED OVER THE SOUTHWESTERN HALF OF THE FORECAST AREA BETWEEN 01-06Z...THEN SHIFTS TO FAR SOUTHWEST WI BETWEEN 06-09Z BEFORE EXITING. PRECIPITATION CHANCES HAVE BEEN ADJUSTED TO FIT THE TIMING OF THE LIFT SIGNAL. STILL DOES NOT LOOK LIKE THERE WILL BE MUCH SNOW GIVEN THE WEAK NATURE OF THE LIFT...PRECIPITABLE WATER ONLY 0.1-0.2 OF AN INCH...AND THE SNOW RUNNING INTO THE DRY AIRMASS CURRENTLY IN PLACE. ANY LIFT TOO IS MOSTLY ABOVE THE DENDRITIC GROWTH ZONE. PREVIOUS FORECAST AMOUNTS OF LESS THAN 1 INCH SEEM REASONABLE. REGARDING TEMPERATURES. 925MB READINGS AT 18Z TODAY ARE SIMILAR TO YESTERDAY AT 18Z...BETWEEN -13 AND -16C. ONLY DIFFERENCES BETWEEN TODAY AND YESTERDAY IS MORE CLOUD COVER AND STARTING OFF COLDER... WHICH SHOULD KEEP HIGHS A LITTLE COOLER. IN THE WAKE OF THE SHORTWAVE TROUGH PASSAGE TONIGHT...925MB TEMPS COOL TO -14 TO -19C. A NORTHWEST BREEZE COMBINED WITH CLOUDS SHOULD HELP TO HOLD LOWS UP SOMEWHAT...BUT READINGS SHOULD FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO THROUGH ADVECTION...COLDEST OVER THE NORTHWEST HALF OF THE FORECAST AREA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 300 AM CST MON FEB 24 2014 THE BIG IMPACT STORY HERE IS THE COLD... SHORTWAVE TROUGH CURRENTLY OVER THE NUNAVUT/NORTHWEST TERRITORIES REGION IS PROGGED TO DROP THROUGH THE FORECAST AREA LATE TUESDAY...USHERING IN THE FIRST SURGE OF BITTER COLD ARCTIC AIR. TROUGH SHOULD GO THROUGH PRECIP FREE WITH JUST SOME CLOUDS. 925MB TEMPS PLUMMET TO -21 TO -24C BY 06Z WEDNESDAY...SENDING SURFACE TEMPERATURES DOWN BELOW ZERO. WITH THE COLD AIR FIRMLY ENTRENCHED FOR 06-12Z...TEMPERATURES SHOULD IN MOST LOCATIONS DIP INTO TEENS BELOW ZERO. MOS GUIDANCE WIND FORECASTS SUGGEST THE TYPICAL COLD SPOTS COULD DECOUPLE...THUS HAVE THEM APPROACHING 20 BELOW. A WIND CHILL ADVISORY IS A GIVEN FOR TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BREAK IN THE COLD AIR COMES WEDNESDAY AFTERNOON AS WESTERLY WINDS INCREASE AND PULL IN SOME DOWNSLOPED AIR OFF THE ROCKIES. THIS INCREASE IS A RESULT OF THE NEXT SHORTWAVE TROUGH NEAR THE NORTH POLE DROPPING INTO THE MN ARROWHEAD. 925MB WINDS APPROACH 45-50 KT AT 00Z THURSDAY WEST OF THE MISSISSIPPI RIVER...BRINGING UP CONCERN OF A POSSIBLE WIND ADVISORY. HOWEVER...A STRONG INVERSION LOOKS TO DEVELOP TO PRECLUDE MIXING THOSE HIGHER WINDS DOWN. IT STILL WILL BE BRISK...THOUGH...AND STRONG ENOUGH TO RESULT IN SOME BLOWING AND DRIFTING OF SNOW IN OPEN AREAS. NEXT ARCTIC COLD SHOT WHICH IS MUCH MORE IMPRESSIVE COMES IN LATE WEDNESDAY NIGHT. THE AFOREMENTIONED NORTH POLE SHORTWAVE CROSSES UPPER MICHIGAN WEDNESDAY NIGHT...DRAGGING AN ARCTIC COLD FRONT THROUGH THE FORECAST AREA. A STRONG PRESSURE RISE IS PROGGED BEHIND THIS FRONT WHICH SHOULD RESULT IN A PERIOD OF BRISK NORTHWEST WINDS. THEN 925MB TEMPS PLUMMET TO -23 TO -27C AT 12Z THURSDAY. DID NOT GO AS COLD AS THESE WOULD SUGGEST GIVEN THE LATE ARRIVAL OF THE COLD AIR AND PLENTY OF WIND. STILL...THE WIND CHILLS ARE PLENTY LOW ENOUGH FOR AN ADVISORY. THURSDAY AND THURSDAY NIGHT LOOK DOWNRIGHT COLD. 850MB TEMP ANOMALIES ARE PROGGED BETWEEN 2.5-3 STANDARD DEVIATIONS BELOW NORMAL...SUGGESTING RECORD TERRITORY. IN ADDITION...HIGH PRESSURE SETTLES OVERHEAD THURSDAY NIGHT...SETTING UP POTENTIAL FOR TEMPERATURES TO TANK. ONLY CAVEAT WILL BE SOME INCREASING MID/HIGH CLOUDS LATER THURSDAY NIGHT. SOME WISCONSIN COLD SPOTS COULD DIP TO 30 BELOW OR COLDER...AS INDICATED BY THE MEX GUIDANCE. FOR FRIDAY THROUGH MONDAY...THE FORECAST AREA WILL BE IN-BETWEEN ARCTIC COLD UPPER TROUGHING ENCOMPASSING MUCH OF SOUTHERN CANADA AND SHORTWAVE TROUGHS TRAVERSING THE SOUTHERN 2/3 OF THE U.S.. AT THE SAME TIME AT THE SURFACE...ARCTIC HIGH PRESSURE SHOULD BE IN PLACE FOR MUCH OF THE TIME. ONE SHORTWAVE MAY BRING SOME LIGHT SNOW TO LOCATIONS SOUTH OF I-90 ON FRIDAY...IF IT CAN MAKE IT THROUGH THE DRY AIR. ONLY KEPT 20 PERCENT CHANCES IN FOR THIS TIME PERIOD. SAME HOLDS TRUE FOR ANOTHER SHORTWAVE TROUGH GOING BY SATURDAY NIGHT INTO SUNDAY...THOUGH THE TRACK IS A BIT FARTHER NORTH SO CHANCES ARE A LITTLE HIGHER. TEMPERATURES WILL STAY WELL BELOW NORMAL BEING UNDER THE INFLUENCE OF THE ARCTIC SURFACE HIGH...THOUGH SOME GRADUAL MODERATION SHOULD TAKE PLACE AS THE EARLY MARCH SUN WORKS ON THE AIR. MORE WIND CHILL ADVISORIES ARE LIKELY...THOUGH...ESPECIALLY FRIDAY NIGHT INTO SATURDAY MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1130 PM CST SUN FEB 23 2014 VFR CONDITIONS TO CONTINUE THROUGH MONDAY AS HIGH PRESSURE SINKS SLOWLY INTO MONTANA WHILE KEEPING THE RIDGE EXTENDING FROM THE HIGH OVER IOWA INTO ILLINOIS. A SHORT WAVE TROUGH APPROACHING FROM THE NORTHWEST WILL START TO SPREAD HIGH AND MID LEVEL CLOUDS OVER THE AREA THROUGH THE AFTERNOON WITH GRADUALLY LOWER CEILINGS. THE FORCING FROM THE WAVE WILL START TO MOVE IN MONDAY EVENING AND THE CONCERN BECOMES WHETHER THE FORCING WILL BE STRONG ENOUGH TO PRODUCE SATURATION OR NOT. THE 24.00Z NAM SUGGEST THE BEST ISENTROPIC UP GLIDE ON THE 275K SURFACE WILL STAY SOUTH OF THE AREA WITH AROUND 30 MB NEEDED TO OBTAIN SATURATION. IF THIS OCCURS...WOULD NOT EXPECT MUCH MORE THAN FLURRIES TO OCCUR. THE 24.00Z GFS ALSO SHOWS THE BEST ISENTROPIC UP GLIDE STAYING SOUTH BUT IS STRONGER THAN THE NAM FOR WHAT IT DOES BRING ACROSS THE AREA...BETWEEN 2 AND 3 UBAR/S. THE GFS DOES SATURATE AND WOULD BRING LIGHT SNOW INTO KRST DURING THE EVENING AND TO KLSE AFTER 25.06Z. THE 23.21Z SREF WOULD SUGGEST THE BEST VISIBILITY REDUCING SNOW WILL STAY SOUTH WITH THE BETTER FORCING...BUT DOES SHOW PRETTY DECENT PROBABILITIES OF A VISIBILITY OF 3 MILES OR LESS AT KRST. HAVE THUS BROUGHT IN MVFR CONDITIONS WITH LIGHT SNOW TO KRST FOR MONDAY EVENING. && .CLIMATE... ISSUED AT 300 AM CST MON FEB 24 2014 GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS HOW FEBRUARY AND THE WINTER OVERALL WOULD STACK UP COMPARED TO RECORDS BASED ON THE CURRENT FORECAST... ...FOR THE MONTH OF FEBRUARY... LA CROSSE... 9.3 AVERAGE TEMPERATURE...3RD COLDEST COLDER FEBRUARYS... 1873... 3.9 1936... 4.3 ROCHESTER... 6.7 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1936... 0.5 1979... 5.7 1917... 6.0 ...FOR THE WINTER...DECEMBER THROUGH FEBRUARY... LA CROSSE... 11.5 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1872-1873... 8.4 1874-1875... 10.5 1977-1978... 11.4 1935-1936... 11.4 ROCHESTER... 8.8 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1978-1979... 5.6 1886-1887... 5.9 1935-1936... 8.1 1977-1978... 8.7 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...04 CLIMATE...AJ/RRS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1000 PM MST TUE FEB 25 2014 .UPDATE... ISSUED AT 803 PM MST TUE FEB 25 2014 SNOTELS IN THE NORTHERN MOUNTAINS INDICATED ACCUMULATIONS HAD ENDED AT MOST LOCATIONS AND ONLY BUFFALO PARK HAD PICKED UP ANY MEASURABLE ACCUMULATION IN THE PAST COUPLE OF HOURS. SATELLITE INDICATED THAT THE TROUGH AXIS HAD EXITED THE ADVISORY AREA. CONSEQUENTLY...CONFIDENT SHORT RANGE MODELS ARE CORRECT IN PRODUCING LITTLE TO NO ADDITIONAL SNOWFALL IN THE ELKHEAD AND PARK RANGES. THEREFORE...WENT AHEAD AND CANCELLED THE WINTER WEATHER ADVISORY WHICH WAS IN EFFECT FOR THE AREA THROUGH WEDNESDAY MORNING. && .SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT) ISSUED AT 252 PM MST TUE FEB 25 2014 SHORT TERM FORECAST THROUGH THIS EVENING IS BASED ON RAP MODEL TRENDS THAT SNOW WILL EXPAND SOUTHWARD OVER ROUTT COUNTY EARLY THIS AFTERNOON. AS OF 21Z...STEAMBOAT LAKE WEB CAM INDICATE THAT SNOW HAS REACHED HAHNS PEAK VICINITY...BUT NO MOUNTAIN TOP OBSCURATION NEAR STEAMBOAT SPRINGS. EXPECT THIS TO CHANGE WITHIN THE NEXT COUPLE OF HOURS AS LEADING EDGE OF BAROCLINIC ZONE AND DECENT GRADIENT NORTHWEST FLOW LEADS TO OROGRAPHIC SNOW OVER THE MT ZIRKEL WILDERNESS AREA AND THE PARK RANGE. RAP MODEL INDICATES RAIN/SNOW BAND MAY EXTEND AS FAR WEST AS MAYBELL AND MEEKER LATE THIS AFTERNOON AS THE MOISTURE BAND SLIDES SOUTH AND EAST. PRIMARY CONCERN IS THAT THE AMPLIFYING UPSTREAM RIDGE AXIS HAS PINCHED OFF THE PACIFIC MOISTURE STREAM INTO NORTHWEST COLORADO... THIS IS EVIDENT ON THE SATELLITE IMAGES. NOT SURE WHETHER THE FORECASTED SNOW AMOUNTS FOR THE PARK RANGE WILL REACH THE UPPER RANGE OF AROUND 7 INCHES...BUT RAP QPF STILL INDICATE THAT A FEW INCHES OF SNOW REMAIN POSSIBLE. WITH SNOW OBSERVED AT RIVERTON AND LANDER IN WEST CENTRAL WYOMING...GIVING CREDENCE THAT THE SNOW IS ON THE WAY. LESSER AMOUNTS OF SNOW IS ANTICIPATED FOR THE FLAT TOP MOUNTAINS AND GORE RANGE (VAIL PASS)...DO NOT THINK THAT AN EXPANSION OF THE WINTER WEATHER ADVISORY IS NECESSARY. MOISTURE STREAM SLIDES EAST AFTER MIDNIGHT WITH MID LEVEL DRY STABLE AIR ADVECTING INTO NORTHWEST COLORADO...THIS WILL SHUT DOWN OROGRAPHIC SNOW FAIRLY QUICKLY LATE TONIGHT. FOR THE SERN HALF OF THE FORECAST AREA THROUGH TONIGHT...CLEAR AND DRY WEATHER IS EXPECTED FOR THE NEXT 12 TO 18 HOURS. WEST COAST RIDGE SHIFTS INLAND ON WEDNESDAY BUT BROAD ISENTROPIC UPGLIDE WILL RESULT IN AN INCREASE OF MID/HIGH LEVEL CLOUDS FROM THE SOUTHWEST. NAM AND GFS SHOWING HINTS OF MOUNTAIN TOP SPOTTY SNOW WEDNESDAY AFTERNOON AND NIGHT. SOMETIMES THIS IS OVERDONE BUT THE TREND WILL BE FOR INCREASING CLOUDS WITH CIRROSTRATUS EVOLVING INTO ALTOSTRATUS. WITH THE INCREASED CLOUD COVER...EXPECT RELATIVELY MILD CONDITIONS WEDNESDAY NIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 252 PM MST TUE FEB 25 2014 THE FORECAST AREA COMES UNDER THE INFLUENCE OF THE SUBTROPICAL JET THROUGH THE WEEKEND. THIS TYPICALLY BRINGS BETTER MOISTURE BUT MILDER TEMPERATURES WITH ASSOCIATED STORMS. BREEZY TO WINDY CONDITIONS ARE EXPECTED IN THE MTNS AND HIGH VALLEYS...INTO THE LOWER VALLEYS WITH SHOWERS. THURSDAY...A TRANSIENT RIDGE PASSES IN THE EARLY AFTERNOON WITH DEEPENING MOISTURE IN SW FLOW. 700MB SPECIFIC HUMIDITIES CLIMB TO 4 G/KG IN THE AFTERNOON. THERE IS SOME MODEL DISAGREEMENT ON TEMPERATURES AND SNOW LEVELS. A COMPROMISE PUTS THE SNOW LEVELS AROUND 7500FT/8500FT NORTH/SOUTH. THE DEEPEST MOISTURE IS IN THE SOUTHERN-CENTRAL MTNS. MARGINAL INSTABILITY PRODUCES AREAS OF STRONGER SHOWERS AND BRIEFLY LOWER SNOW LEVELS. THURSDAY NIGHT...THE BEST FORCING OCCURS AS THE SUBTROPICAL JET PUSHES INTO THE SOUTH THEN LIFTS INTO THE CENTRAL ZONES. SNOW LEVELS LOWER INTO THE NORTHERN VALLEYS...TO 7500FT SOUTH. FRIDAY IS A BRIEF BREAK UNDER AS A LOCAL RIDGE IS AMPLIFIED AHEAD OF THE NEXT STRONG STORM BRINGING WARM ADVECTION. MOISTURE REMAINS AT 4 G/KG SO SHOWERS INCREASE INTO THE AFTERNOON. FRIDAY NIGHT-SATURDAY NIGHT...THE NEXT SUBTROPICAL JET STREAK LIFTS THE EASTERN UTAH FRIDAY NIGHT THEN ACROSS WESTERN COLORADO ON SATURDAY. AGAIN THERE IS A CONVECTIVE COMPONENT FRIDAY NIGHT INTO SATURDAY. THERE IS AGAIN A CONVECTIVE COMPONENT TO THIS STORM. SNOWFALL WILL FAVOR THE SOUTHERN AND CENTRAL MTNS. SNOW LEVELS AROUND 7000FT. SATURDAY NIGHT IS TROUGH PASSAGE WITH NW FLOW DEVELOPING. SNOW LEVEL DROPS TO AROUND 5000FT BUT WILL FAVOR THE NW-FACING SLOPES OF THE COLORADO MTNS. SUNDAY-TUESDAY...ARE NOW A FLAT ZONAL FLOW WITH THE POLAR FRONT JET SETTLING INTO WYOMING THEN RAKING THE NORTH ON MONDAY. EXPECT COOLER TEMPERATURES THROUGH THESE PERIODS WITH THE BEST SNOWFALL FAVORING THE NORTHERN MTNS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 958 PM MST TUE FEB 25 2014 VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH 06Z THU...BUT LOW CLOUDS MAY BE PROBLEM FOR THE ERN UINTA MOUNTAINS AND NRN CO MOUNTAINS INCLUDING KHDN/KSBS THROUGH MID-MORNING. AN UPPER DISTURBANCE CROSSING NE CO PUSHED A COLD FRONT ACROSS NW CO TO ABOUT THE I-70 CORRIDOR BEFORE CURVING BACK ACROSS NE UT. FRONT SHOULD STALL OVERNIGHT. A BAND OF LOW-MID LEVEL CLOUDS EXTENDED FROM THE CENTRAL DIVIDE AREA BACK ACROSS NW CO AND SW WY AND SHOULD PERSIST UNTIL 12Z-15Z WED WITH MOUNTAIN TOPS OCCASIONALLY OBSCURED IN CLOUDS/-SN FROM KASE/VAIL PASS NORTHWARD TO K3MW. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...NL SHORT TERM...PF LONG TERM...JOE AVIATION...JAD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
411 AM EST Wed Feb 26 2014 .Near Term [Through Today]... At 09z, a surface cold front extended from a weak low in SC, southwest to near Albany GA, to near Destin FL, and then along much of the rest of the LA-TX Gulf coast. Regional radars showed a fairly large area of rain along and to the north of the surface cold front from near the AL-GA state line westward to SE TX. The placement of the rain relative to the surface front was suggestive of an anafront structure, with rearward sloping ascent along the cold front through the vertical. This is confirmed by WSW flow on area radar VWPs in the 900-700mb layer, and from a glance at RAP isentropic charts. Given the isentropic ascent in the lowest levels of the troposphere, but a general lack of significant forcing aloft, it`s likely that rain will continue to be forced in a shallow layer just above the surface through the remainder of the day. Models are in fairly good agreement on the timing of the best isentropic ascent and QPF. We leaned towards the consensus of recent local and NCEP WRF runs. With widespread rain expected, PoPs were raised to 100% for today pretty much everywhere across the forecast area. The rain should be most widespread (and heaviest) in the morning, with it tapering off and clearing from NW-SE in the afternoon and early evening. Looking at GOES blended precipitable water product, there is a large plume of PWATS >150% of normal extending from the western parts of our forecast area west into Texas. This deeper moisture will continue to advect into the area today, and could support some locally heavier rain. This will be especially true near the Gulf coast - closer to the surface cold front as the strongest forcing for ascent arrives this morning after sunrise. Maximum QPF from convection allowing models (CAM) is focused around Gulf and Franklin counties and is on the order of 2-3 inches. With the heaviest rain likely to fall in the lower portions of river basins, and average rainfall generally between 0.50 and 1.00 inches, we don`t anticipate any significant flooding issues. Instability should be limited enough to only support some general thunderstorms - updrafts should be too weak to pose much of a severe weather concern. .Short Term [Tonight Through Friday]... Rain will taper off from north to south this evening, but may not clear completely from our Southeast FL Big Bend zones until Thursday morning. As skies clear behind the rain, temps will tumble into the 30s except for coastal and southeastern sections of the Big Bend. A light freeze is forecast along and north of an Albany to Dothan to Crestview line. Maximum freeze durations in Coffee County AL will be about 5 hours. Max temps will be about 10 degrees below normal on Thursday and range from the mid 50s far northwest to Around 60 southeast. This will set the stage for a widespread light freeze Thursday night that will impact most inland areas. Coastal locations will hold at 40. Temps will moderate to within a few degrees of normal on Friday with max temps ranging from the lower 60s north to the mid to upper 60s southeast. .Long Term [Friday Night Through Wednesday]... On Friday NIGHT, a shortwave will be moving across the Mid Atlantic states. Further to the west, a disturbance will be moving onshore into central California. A vort max located over the Rockies will propagate eastward in zonal flow bringing slight PoP chances on Saturday, however this forcing appears to be weak and displaced more to the north of our CWA. From here on the GFS and Euro really diverge in their handling of the upcoming pattern. The GFS is more aggressive in phasing a shortwave over western Mexico with a shortwave rounding the base of a trough over Idaho. This combination pushes a surface front through our area late Monday night into Tuesday but quickly exits the area. The Euro meanwhile remains less amplified keeping the flow aloft more zonal and bringing a series of vort maxes through the area early next week. This will cause a stalling of a surface front over our CWA, and with each passing upper-level vort max another round of rain. Both agree that Tuesday morning should be pretty wet but given the uncertainty with which this front will exit we have tentatively gone with 40 PoPs for Tuesday afternoon. && .Aviation... [Through 06Z Thursday] Rain will quickly spread into the area in the early morning hours - affecting all terminals. -RA should first arrive at DHN/ECP around 09z, eventually reaching VLD around 12z. We expect IFR CIGS to develop at all terminals prior to 14z, except ABY where low end MVFR CIGS are expected. Some +RA with TS will be possible closer to the Gulf coast, particularly at ECP and TLH. Some of the +RA could reduce visibilities to around 1-3SM at times. Rain will gradually clear out in the afternoon from NW-SE, with CIGS gradually lifting through MVFR to VFR range by the evening. && .Marine... A cold front will slip south across the waters today shifting winds to offshore. Wind speeds behind the front will reach marginal small craft advisory criteria across the western legs by midday. Advisory conditions will be possible across the eastern zones tonight. Winds will then drop below cautionary levels by midday Thursday as high pressure builds toward the waters. Winds will remain below headline criteria through the weekend as they gradually veer to the east and then southeast. && .Fire Weather... Widespread wetting rains are expected today, which will leave fuel moisture rather high on Thursday. Some of the finer (smaller) fuels (measured by 10-hr fuel moisture) could dry out as a much drier air mass arrives for Thursday, but should not be sufficiently dry in Florida or Georgia to create red flag conditions. In southeast Alabama, red flag criteria includes 4+ hr durations of RH < 25%. This looks achievable, but the wet fuels would likely preclude any sort of critical fire weather conditions. For now, we will maintain the Fire Weather Watch. It`s possible durations could be met again on Friday in southeast Alabama, and by then smaller fuels would have likely dried more substantially. && .Hydrology... Periods of moderate rain today and tonight across the forecast area will result in slight to modest rises on area rivers. The Choctawhatchee River at Bruce is forecast to crest right at flood stage from Thursday into Saturday. The Apalachicola River at Blountstown is at its crest and is forecast to fall below flood stage Thursday evening. The Aucilla River at Lamont is forecast to reach flood stage Thursday night and crest Friday night. Storm total rainfall through Thursday morning is forecast to be less than an inch north of I-10 with a maximum of near two inches over coastal sections of Gulf and Franklin Counties. With the greatest totals falling in the lower stretches of the river basins, rises will be confined mainly to FL. && .Preliminary Point Temps/PoPs... Tallahassee 60 39 60 29 65 / 100 50 10 0 0 Panama City 60 39 58 36 62 / 100 50 10 0 0 Dothan 54 31 57 31 62 / 100 30 0 0 0 Albany 54 32 58 29 62 / 100 20 0 0 0 Valdosta 58 37 59 30 64 / 100 50 0 0 0 Cross City 65 44 61 30 67 / 100 60 20 0 0 Apalachicola 64 41 58 35 61 / 100 60 10 0 0 && .TAE Watches/Warnings/Advisories... FL...None. GA...None. AL...Fire Weather Watch from Thursday morning through Thursday afternoon for Coffee-Dale-Geneva-Henry-Houston. GM...Small Craft Advisory from 11 AM this morning to 10 AM EST Thursday for Coastal waters from Apalachicola to Destin FL out 20 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. && $$ NEAR TERM...LAMERS SHORT TERM...WOOL LONG TERM... AVIATION...LAMERS MARINE...WOOL FIRE WEATHER...LAMERS HYDROLOGY...BARRY/WOOL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
236 AM EST WED FEB 26 2014 .SYNOPSIS... A FRONT AND UPPER ENERGY WILL PROVIDE A CHANCE OF RAIN TODAY...THEN FAIR...DRIER AND COOLER WEATHER EXPECTED THROUGH LATE WEEK. AN UPPER DISTURBANCE WILL BRING A CHANCE OF SHOWERS FRIDAY NIGHT AND SATURDAY. THE NEXT FRONT WILL AFFECT OUR REGION EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... SURFACE FRONT GENERALLY STRETCHED ACROSS THE CENTRAL FORECAST AREA...STRETCHING WESTWARD INTO THE LOWER MISS VALLEY. THIS ALONG WITH A SERIES OF SOUTHERN STREAM UPPER IMPULSES...AHEAD OF A NORTHERN STREAM UPPER IMPULSE THAT WILL DIVE FROM THE CENTRAL PLAINS INTO THE SE US TODAY...WILL PROMOTE SOME RAIN. LATEST HIGH RESOLUTION MODELS INDICATE RAIN AREA TO OUR WEST WILL SHIFT EAST...REACHING THE CSRA BEFORE DAYBREAK AND SPREADING EAST ACROSS MOST OF THE FA THIS MORNING...MOVING OUT OF THE FA DURING THE AFTERNOON. SLIGHT CHANCE THAT A LITTLE MELTING SNOW COULD MIX WITH RAIN ACROSS THE NORTHERN FA...BUT CHANCES OF THAT APPEAR TOO LOW TO INCLUDE IN THE FORECAST...PLUS ANY SNOW WOULD MELT ON IMPACT WITH NO ACCUM. && .SHORT TERM /TONIGHT THROUGH FRIDAY/... EXPECT CLEARING SKIES BY EARLY EVENING. A SECONDARY DRY FRONT WILL MOVE SOUTH THROUGH THE REGION TONIGHT...FOLLOWED BY ANOTHER DRY FRONT ROLLING THROUGH THURSDAY NIGHT...MAINTAINING A CONTINUED INFLUX OF COOLER AND DRIER AIR. HIGH PRESSURE CENTER WILL BUILD IN FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A WEAK SHORTWAVE TROUGH WILL BRING A CHANCE OF PRECIPITATION FRIDAY NIGHT INTO EARLY SATURDAY. SHORTWAVE TROUGH WILL SHIFT EAST SATURDAY MORNING AS AN UPPER RIDGE BUILDS OVER THE SOUTHEAST CONUS THROUGH SUNDAY WITH DRY WEATHER EXPECTED. THE UPPER RIDGE WILL SHIFT EAST MONDAY AS A TROUGH BUILDS OVER THE WESTERN CONUS. SOME MODEL DIFFERNCES CONTINUE...BUT ECMWF AND GFS GENERALLY SUGGEST NEXT FRONT WITH AVAILABLE ATMOSPHERIC MOISTURE TO AFFECT OUR REGION IN THE MONDAY/TUESDAY TIME FRAME. GENERALLY BLENDED LATEST GUIDANCE WITH ONGOING FORECAST. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... EXPECT MAINLY VFR CONDITIONS DURING THE TAF PERIOD. HOWEVER...MODEL INCONSISTENCIES LOWER THE CONFIDENCE AND THERE IS THE POSSIBILITY OF A PERIOD OF MVFR CONDITIONS WEDNESDAY MORNING. A COLD FRONT WILL SINK SOUTHWARD AND THROUGH THE AREA OVERNIGHT. NORTHERLY WINDS WILL DEVELOP BEHIND THE FRONT DURING THE EARLY MORNING HOURS. EXPECT AN INCREASE IN CLOUDINESS AND THE DEVELOPMENT OF RAIN OVER MOST OF THE AREA DURING THE EARLY MORNING HOURS MAINLY ASSOCIATED WITH A COUPLED H25 JET PATTERN. THE LATEST HRRR SHOWED COVERAGE UPSTREAM INCREASING AND MOVING INTO THE FORECAST AREA AROUND 10-12Z. 88D REGIONAL COMPOSITE ALREADY SHOWS SOME AREAS OF LIGHT RAIN AS FAR EAST AT ALABAMA. CONFIDENCE IS LOW WITH THE CEILING AND VISIBILITY FORECAST BECAUSE OF MODEL INCONSISTENCY. THE NAM MOS INDICATED MVFR OR IFR CEILINGS. THE GFS MOS AND LAMP PLUS SREF GUIDANCE INDICATED CONTINUED VFR CEILINGS AND VISIBILITIES. THE 22Z HRRR INDICATED MAINLY VFR CONDITIONS THROUGH 13Z. LEANED TOWARD THE MORE OPTIMISTIC GUIDANCE BECAUSE OF THE H85 WESTERLY FLOW AND THE INITIAL DRYNESS. ALSO...LOOKING BACK AT UPSTREAM OBS THEY ARE MAINLY IN THE VFR CATEGORY. ALSO...A LACK OF SIGNIFICANT ISENTROPIC LIFT SHOULD HELP KEEP RAIN MAINLY LIGHT AND LIMIT ITS RESTRICTION TO VISIBILITY. THE NAM AND GFS SHOW UPPER-LEVEL LIFT SHIFTING EAST OF THE AREA BETWEEN 16 AND 18Z. RAIN AND LINGERING LOWER CLOUDINESS SHOULD DIMINISH DURING THIS TIME. AFTER 18Z...CLOUDINESS WILL GRADUALLY BECOME BROKEN THEN SCATTERED BY 00Z. AFTER 00Z...WINDS WILL BE GENERALLY REMAIN LIGHT WITH SOME SCATTERED HIGH CLOUDS. EXTENDED AVIATION OUTLOOK...WITH HIGH PRESSURE OVER THE AREA THROUGH THE REMAINDER OF THE WEEK...NOT SIGNIFICANT IMPACTS EXPECTED. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1242 AM EST WED FEB 26 2014 .SYNOPSIS... A GULF COAST LOW PRESSURE SYSTEM WILL MOVE EAST THROUGH GEORGIA AND FLORIDA TONIGHT INTO WEDNESDAY BRINGING A CHANCE OF RAIN TO OUR AREA. DRY AND COOLER WEATHER IS EXPECTED THURSDAY AND FRIDAY WITH ANOTHER CHANCE OF RAIN EARLY SATURDAY WITH A FAST MOVING SYSTEM. && .NEAR TERM /THROUGH WEDNESDAY/... UPDATE...FORECAST REMAINS ON TRACK AS FRONT APPROACHES FROM THE WEST. HAVE ADJUSTED POPS AND CLOUDS TO BETTER REPRESENT CURRENT OBSERVATIONS WITH INCREASING CLOUDS AND CHANCES OF RAIN OVER THE NEXT SEVERAL HOURS. BEST CHANCES OF RAIN WILL BE OVER THE SOUTHERN MIDLANDS AND CSRA OVERNIGHT WITH RAIN SPREADING INTO THE CENTRAL MIDLANDS DURING THE EARLY MORNING HOURS. RAINFALL AMOUNTS THROUGH DAYBREAK ARE EXPECTED TO BE TWO TENTHS OF AN INCH OR LESS. TEMPERATURES REMAIN ON TRACK FOR LOWER 40S FOR THE NORTHERN AND WESTERN MIDLANDS WITH MID 40S TO AROUND 50 ELSEWHERE. PREVIOUS DISCUSSION...CHANCES OF RAIN INCREASE LATE TONIGHT AS BROAD UPPER TROUGH SINKS ACROSS THE GREAT LAKES AND OHIO VALLEY REGION DRIVING A COLD FRONT THROUGH THE FORECAST AREA EARLY WEDNESDAY MORNING BEFORE HIGH PRESSURE BUILDS IN AT THE SURFACE BEHIND THE FRONT WEDNESDAY AFTERNOON. WESTERLY LOW LEVEL FLOW AHEAD OF THE SHORTWAVE AND FRONT IS FORECAST TO BACK MORE SOUTHWESTERLY THIS EVENING ALLOWING FOR ATMOSPHERIC MOISTURE TO INCREASE WITH FLOW OFF THE WESTERN GULF OF MEXICO. HOWEVER...THE TIME FRAME FOR SIGNIFICANT MOISTURE TO MOVE INTO THE REGION BEFORE THE FRONT ARRIVES IS SHORT AND A LIMITING FACTOR DESPITE MODERATE UPPER DYNAMICS ARRIVING AROUND THE 12Z TIME FRAME AS THE NORTHERN AND SOUTHERN STREAM JETS COUPLE TO PROVIDE STRONG OMEGA AND UPWARD VERTICAL MOTION OVER THE FORECAST AREA. HAVE INCREASED POPS SLIGHTLY FROM PREVIOUS FORECAST...HIGHEST POPS FROM THE CSRA ACROSS THE SOUTHEAST MIDLANDS LATE TONIGHT INTO WEDNESDAY MORNING WITH A GRADIENT TO LOWER POPS TO THE NORTHWEST WHERE MOISTURE WILL NOT BE AS GREAT. STILL FIGURE THE BEST TIME FRAME FOR HIGHEST POPS WILL BE FROM 09Z-15Z WITH CHANCES OF RAIN DECREASING FROM NORTHWEST TO SOUTHEAST THROUGH THE DAY WEDNESDAY. LATEST 12Z NAM SOUNDINGS SUGGEST A MIX OF SNOW/RAIN POSSIBLE ACROSS THE NORTHERN MIDLANDS WEDNESDAY MORNING WITH DEEP MOISTURE INTO SNOW GROWTH ZONE AND NEAR SURFACE TEMPERATURES LIKELY IN THE 30S. CONFIDENCE IS LOW HOWEVER WITH LITTLE SUPPORT FROM GFS...I.E. NO MOISTURE IN SNOW GROWTH ZONE. STILL THINK HIGHER POPS WILL BE SOUTH OF THE NORTHERN MIDLANDS...BUT WILL INCLUDE CHANCE SNOW/RAIN SHOWERS ACROSS NORTHERN LANCASTER COUNTY WHERE PARTIAL THICKNESS SCHEMES FAVOR MIX. CLOUDINESS LATE TONIGHT SHOULD KEEP TEMPERATURES FROM FALLING SOMEWHAT...FAVOR WARMER MAV GUIDANCE. TEMPERATURES WILL BE MUCH COOLER WEDNESDAY COMPARED TO TODAY WITH COLD ADVECTION TAKING PLACE DURING THE DAY DESPITE SOME CLEARING SKIES BY AFTERNOON. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... WEDNESDAY NIGHT...THE LOW PRESSURE SYSTEM AND ALL ASSOCIATED PRECIPITATION WILL BE WELL OFFSHORE BY WEDNESDAY NIGHT. COLD AIR ADVECTION AND DECENT RADIATIONAL COOLING CONDITIONS WILL LEAD TO BELOW NORMAL OVERNIGHT LOW TEMPERATURES...IN THE UPPER 20S NORTH TO LOWER 30S SOUTH. THURSDAY THROUGH THURSDAY NIGHT...A BROAD UPPER TROUGH WILL MOVE OVER THE EASTERN CONUS ON THURSDAY PROMOTING WEST-NORTHWESTERLY FLOW ALOFT. AT THE SURFACE...LOW PRESSURE OVER THE GREAT LAKES REGION WILL BRING A DRY COLD FRONT THROUGH THE AREA. TEMPERATURES WILL MAX OUT IN THE MID 50S TO NEAR 60 UNDER SUNNY SKIES. SURFACE HIGH PRESSURE WILL SHIFT INTO THE OHIO VALLEY THURSDAY NIGHT ALLOWING SURFACE WINDS TO ROTATE FROM WESTERLY TO NORTHEASTERLY. MOSTLY CLEAR SKIES OVERNIGHT WILL SET THE STAGE FOR ANOTHER CHILLY NIGHT WITH LOWS IN THE UPPER 20S TO NEAR 30. FRIDAY THROUGH FRIDAY NIGHT...THE UPPER TROUGH WILL BE OFF THE COAST BY FRIDAY WITH UPPER FLOW BECOMING ZONAL. SURFACE HIGH PRESSURE WILL SHIFT OVER THE MID-ATLANTIC AND WEDGE INTO THE FORECAST AREA FOR FRIDAY. TEMPERATURES WILL MAX OUT IN THE UPPER 40S NORTH TO MID 50S SOUTH. A WEAK SHORTWAVE TROUGH WILL BRING A CHANCE OF PRECIPITATION FRIDAY NIGHT INTO EARLY SATURDAY. MOSTLY CLOUDY SKIES OVERNIGHT WITH LOW TEMPERATURES ABOVE FREEZING IN THE LOWER 30S TO NEAR 40. && .LONG TERM /FRIDAY THROUGH TUESDAY/... SHORTWAVE TROUGH WILL SHIFT EAST SATURDAY MORNING AS AN UPPER RIDGE BUILDS OVER THE SOUTHEAST CONUS THROUGH SUNDAY WITH DRY WEATHER EXPECTED. THE UPPER RIDGE WILL SHIFT EAST MONDAY AS A TROUGH BUILDS OVER THE WESTERN CONUS. SIGNIFICANT TIMING DIFFERENCES BETWEEN THE ECMWF AND GFS WITH THE NEXT SYSTEM ARRIVING DURING THE MONDAY/TUESDAY TIME FRAME. THE ECMWF IS A BIT QUICKER BRINGING THE SYSTEM THROUGH THAN THE GFS. BELOW NORMAL MAX TEMPERATURES ON SATURDAY BUT OTHERWISE NEAR NORMAL HIGHS IN THE 60S FOR THE REST OF THE EXTENDED. LATEST GUIDANCE HAS CONTINUED TO TREND UP WITH TEMPERATURES FOR SUNDAY AND MONDAY. && .AVIATION /06Z WEDNESDAY THROUGH MONDAY/... EXPECT MAINLY VFR CONDITIONS DURING THE TAF PERIOD. HOWEVER...MODEL INCONSISTENCIES LOWER THE CONFIDENCE AND THERE IS THE POSSIBILITY OF A PERIOD OF MVFR CONDITIONS WEDNESDAY MORNING. A COLD FRONT WILL SINK SOUTHWARD AND THROUGH THE AREA OVERNIGHT. NORTHERLY WINDS WILL DEVELOP BEHIND THE FRONT DURING THE EARLY MORNING HOURS. EXPECT AN INCREASE IN CLOUDINESS AND THE DEVELOPMENT OF RAIN OVER MOST OF THE AREA DURING THE EARLY MORNING HOURS MAINLY ASSOCIATED WITH A COUPLED H25 JET PATTERN. THE LATEST HRRR SHOWED COVERAGE UPSTREAM INCREASING AND MOVING INTO THE FORECAST AREA AROUND 10-12Z. 88D REGIONAL COMPOSITE ALREADY SHOWS SOME AREAS OF LIGHT RAIN AS FAR EAST AT ALABAMA. CONFIDENCE IS LOW WITH THE CEILING AND VISIBILITY FORECAST BECAUSE OF MODEL INCONSISTENCY. THE NAM MOS INDICATED MVFR OR IFR CEILINGS. THE GFS MOS AND LAMP PLUS SREF GUIDANCE INDICATED CONTINUED VFR CEILINGS AND VISIBILITIES. THE 22Z HRRR INDICATED MAINLY VFR CONDITIONS THROUGH 13Z. LEANED TOWARD THE MORE OPTIMISTIC GUIDANCE BECAUSE OF THE H85 WESTERLY FLOW AND THE INITIAL DRYNESS. ALSO...LOOKING BACK AT UPSTREAM OBS THEY ARE MAINLY IN THE VFR CATEGORY. ALSO...A LACK OF SIGNIFICANT ISENTROPIC LIFT SHOULD HELP KEEP RAIN MAINLY LIGHT AND LIMIT ITS RESTRICTION TO VISIBILITY. THE NAM AND GFS SHOW UPPER-LEVEL LIFT SHIFTING EAST OF THE AREA BETWEEN 16 AND 18Z. RAIN AND LINGERING LOWER CLOUDINESS SHOULD DIMINISH DURING THIS TIME. AFTER 18Z...CLOUDINESS WILL GRADUALLY BECOME BROKEN THEN SCATTERED BY 00Z. AFTER 00Z...WINDS WILL BE GENERALLY REMAIN LIGHT WITH SOME SCATTERED HIGH CLOUDS. EXTENDED AVIATION OUTLOOK...WITH HIGH PRESSURE OVER THE AREA THROUGH THE REMAINDER OF THE WEEK...NOT SIGNIFICANT IMPACTS EXPECTED. && && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 PM MST TUE FEB 25 2014 .UPDATE... ISSUED AT 1048 PM MST TUE FEB 25 2014 SNOW IS MOVING SOUTH AND DECREASING IN IN COVERAGE AND INTENSITY. DRAMATIC CLEARING IS OCCURRING BEHIND THE SNOW BAND. SO LOWERED MINS MORE. UPDATE ISSUED AT 811 PM MST TUE FEB 25 2014 JUST COMPLETED ANOTHER UPDATE. BAND OF SNOW IS HOLDING TOGETHER VERY WELL DESPITE WHAT EARLIER MODEL OUTPUT SAID. STRONG MID LEVEL FRONTOGENESIS AND UPPER LEVEL DEFORMATION IS WORKING ITS WAY ACROSS. SNOW IS LIGHT PROBABLY DUE TO THE VERY POOR THETA-E LAPSE RATES BUT STILL IT IS GOING TO SNOW. SO RAISED POPS TO 100 PERCENT FOR THE REST OF THE EVENING AS THIS BAND WORKS ITS WAY SOUTH. WITH THE SLOWER PROGRESSION OF THE BAND AND LINGERING DYNAMICS...HAVE KEPT THE POPS GOING FOR A FEW HOURS AFTER 06Z. OTHERWISE MADE SLIGHT ADJUSTMENTS IN THE TEMPERATURES. UPDATE ISSUED AT 604 PM MST TUE FEB 25 2014 NICE BAND OF SNOW STILL OVER THE FAR NORTH AT THIS TIME WITH A SLOW SHIFT SOUTH. SOME UNCERTAINTY HOW FAR SOUTH THIS BAND WILL GET AND HOW FAST IT WILL DO IT. MESOSCALE GUIDANCE IS INDICATING THAT THIS BAND WILL THIN AND WEAKEN AS IT MOVES SOUTH. DO HAVE A RIGHT REAR QUADRANT OF JET AND STRONG PV ANOMALY MOVING IN FROM THE NORTHWEST. SO AM THINKING THE BAND WILL HOLD TOGETHER. SO UPPED UP POPS TO DEFINITE IN THE NORTH AND INCREASED THE REMAINING PORTION OF THE AREA SLIGHTLY. ALSO MADE A SLIGHT ADJUSTMENT TO THE WINDS BASED ON THE HRRR. LOOKS LIKE THERE WILL BE A QUICK AND DRAMATIC CLEARING TREND AFTER THE SNOW ENDS. WINDS WILL BE LIGHT FOR A LITTLE WHILE BEFORE PICKING UP LATER IN THE NIGHT. AM THINKING THAT WE HAVE THE POTENTIAL TO BE MUCH COLDER THAN CURRENTLY INDICATED. SO DID MAKE A SLIGHT ADJUSTMENT COLDER FOR THE NIGHT AND WILL CONTINUE TO WATCH THE TRENDS CLOSELY AND SEE WHAT THE NEWER GUIDANCE WILL TELL ME. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 113 PM MST TUE FEB 25 2014 MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2 INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS AROUND 5 TO 10 ABOVE ZERO. AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40 AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL AND SREF FOR TOMORROW`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
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
400 AM EST WED FEB 26 2014 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL CROSS THE REGION THROUGH MIDDAY. LOW PRESSURE OVER THE GREAT LAKES WILL USHER IN CANADIAN AIR TO THE REGION THROUGH FRIDAY. A WEAK DISTURBANCE WILL SLIDE ACROSS THE AREA SATURDAY BEFORE A MORE POTENT LOW PRESSURE SYSTEM BEGINS TO AFFECT THE REGION EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 0830Z...NO SNOW REPORTED EAST OF THE ALLEGHENY FRONT...BUT ECHOES ARE INCREASING AND THE CLOUD CEILING IS LOWERING LIKE A BLANKET OVER THE AREA...PARTICULARLY EAST OF THE BLUE RIDGE. EXPECT LIGHT TO MODERATE SNOW REPORTS TO BECOME COMMON 5-7AM WITH THE MOST INTENSE RATES FROM 7-11AM BEFORE A QUICK CHANGEOVER TO SCATTERED FLURRIES THROUGH MIDDAY...SOMEWHAT LIKE THE SNOW FROM TUESDAY (WITH AN EARLIER ONSET AND MORE WIDESPREAD ACCUMULATIONS). 06Z HRRR HAS SHIFTED MAX OF SNOW (3-4") OVER WRN DC SUBURBS DOWN TO RAPPAHANNOCK COUNTY. THE PREVIOUS SEVERAL RUNS HAD PUT A MAX OF 4+" OVER CULPEPER COUNTY. ACCORDING TO THE 00Z GFS/ECMWF...THE JET STREAM AXIS WILL BE OVER NRN SECTIONS OF THE CWA WITH THE SRN 2/3 IN THE RIGHT ENTRANCE REGION THROUGH THE MORNING HOURS. UPPER TROUGH IS STILL BROAD WITH NO DISCERNIBLE AXIS AT H5. NWLY FLOW IS EXPECTED TO SPREAD OVER THE AREA MIDDAY THROUGH THE AFTERNOON WHICH WOULD DOWNSLOPE AND LIMIT PRECIP TO SCATTERED FLURRIES. TONIGHT...NLY FLOW AS SFC HIGH SPREADS IN ALONG MASON-DIXON LINE. HOWEVER...A DEVELOPING LOW OVER THE GREAT LAKES BEGINS TO INFLUENCE THE AREA BRINGING A SLY FLOW BY LATE TONIGHT. MIN TEMPS IN CLEAR CONDITIONS GENERALLY MID TEENS. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... THE QUICK EXIT OF TODAY`S SYSTEM WILL ALLOW THE AREA TO CLEAR OUT INTO EARLY THU. WINDS WILL ACTUALLY SWITCH BACK TO SLY FOR A BRIEF PERIOD AS HIGH PRESSURE SQUEEZING IN BETWEEN THE EXITING SYSTEM AND THE NEXT WAVE OF POLAR AIR. THE WED STORM SYSTEM WILL HAVE GRABBED ESSENTIALLY ALL OF THE AVAILABLE MOISTURE FROM THE GULF REGION...TAKING IT OFF THE COAST AHEAD OF THE APPROACHING UPPER VORT FROM THE GREAT LAKES REGION. WED NIGHT WILL BE A COLD NIGHT...BUT W/ THE ARRIVAL OF THIS LATEST WAVE OF ARCTIC AIR...THU NIGHT WILL LIKELY BE A FEW DEG COLDER AND SEVERAL DEG DRIER IN TERMS OF DEWPOINTS. A VERY DRY AIRMASS W/ DEWPOINTS BELOW ZERO ACROSS THE REGION AND ADEQUATE RADIATING TO ALLOW TEMPS TO DROP WELL INTO THE TEENS AND SINGLE DIGITS. THE NIGHT WILL ALSO START OFF W/ A STEADY NW BREEZE WHICH WILL ONLY FURTHER DROP WIND CHILL VALUES INTO THE SINGLE DIGITS AND TOWARD ZERO. THIS LATEST ANOMALOUSLY COLD AIRMASS THOUGH WILL BE ANOTHER QUICK-HITTER W/ AN WELL ON ITS WAY TOWARD NEW ENGLAND THU NIGHT INTO EARLY FRI. THE VORT`S EXIT WILL MEAN A SUBSTANTIAL DROP OFF IN WINDS ON FRI...NEAR CALM EVEN DURING THE DAYTIME HRS. BUT THE ARCTIC AIRMASS WILL HAVE LEFT SUCH DRY AIR IN ITS WAKE THE TEMPS WILL HAVE A TOUGH TIME RECOVERING MUCH ABOVE THE M20S BY AFTN - EVEN UNDER AMPLE SUN. && .LONG TERM /FRIDAY THROUGH TUESDAY/... WHILE TEMPS MAKE A SLOW/STEADY RECOVERING HEADING INTO THE WEEKEND...ZONAL UPPER FLOW WILL BE ANYTHING BUT SLOW IN BRINGING IN THE NEXT COUPLE OF LOW PRESSURE WAVES. THE FIRST WILL BE A WEAKLY ORGANIZED SHORTWAVE W/ LITTLE MOISTURE INVOLVED AND ONLY BRIEFLY BRINGING THE CHANCE FOR SOME LIGHT PRECIP DURING THE DAY DURING MOVING OFF THE COAST. ANY PRECIP FALLING DURING THE MRNG HRS ON SAT MAY BE SNOW BUT TEMPS ARE EXPECTED TO GRADUALLY RISE INTO THE M-U30S BY AFTN...SO LIQUID PRECIP WILL BE MORE LIKELY W/ ANY RESIDUAL SHOWERS. FOCUS THEN TURNS TO A LARGE SCALE AND POTENT STORM SYSTEM DEVELOPING ACROSS A BULK OF THE CONUS. MULTIPLE WAVES OF ENERGY WILL COMBINE OVER THE WRN HALF OF THE COUNTRY SAT INTO SUN...PUSHING INTO THE PLAINS AND EVENTUALLY TOWARD THE EAST COAST LATE SUN INTO MON. THE WARM FRONT WILL FOR A TIME EXTEND ALL THE WAY FROM THE ROCKIES TO THE ATLC COAST...SETTLING ALONG AND NORTH OF THE MASON-DIXON LINE AS THE SYSTEM APR ROACHES. THE FREEZING LINE WILL ALSO BE HOVERING AROUND THIS AREA SUN AND MON W/ PERIODIC WAVES OF LIGHT PRECIP SLIDING BY DURING THE TIME. WILL MONITOR LONG TERM GUIDANCE TRENDS FOR THE BULK OF EXPECTED PRECIP TO PASS OVER THE REGION...00Z RUNS LOOKING LIKE LATE SUN INTO MON...W/ SOME LINGERING PRECIP INTO TUE. THE BACK EDGE OF THE PRECIP MAY BE A RAIN/SNOW MIX W/ SNOW IN THE NW PERIPHERY OF THE AREA W/ CURRENT TRENDS. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... SNOW ONSET 9 TO 11Z ACROSS THE TERMINALS WITH LIGHT TO MODERATE SNOW THEN UNTIL 15-17Z AND FLURRIES EARLY THIS AFTERNOON. IFR CONDS IN HEAVIEST PERIOD WITH LIFR IN MODERATE SNOW BY DEFINITION. VFR WITH NWLY FLOW GUSTING TO 25 KT THIS AFTERNOON. NLY FLOW THIS EVENING...SWINGING AROUND TO SLY BY DAYBREAK THURSDAY. A DEEP AND COLD UPPER TROUGH WILL ENCOMPASS THE EAST COAST DURING THE MIDDLE OF THE WEEK...BRINGING GUSTY WINDS TO THE AREA WED AND THU. ONLY A BRIEF PERIOD OF SNOW POSSIBLE WED MRNG AS ONE WAVE OF THIS SYSTEM MOVES ACROSS THE AREA BUT ONLY LIGHT AMTNS EXPECTED. THE AREA WILL CLEAR OUT LATER IN THE DAY WED...STAYING DRY AND QUIET INTO THE WEEKEND. && .MARINE... LIGHT EAST FLOW EARLY THIS MORNING BECOMES WEST AND INTENSIFIES LATER THIS MORNING...WITH STRONG NWLY FLOW THIS AFTERNOON. SCA FOR ALL WATERS STARTS AT 8AM...BUT AREAS OF SNOW WILL KEEP WINDS DOWN PROBABLY UNTIL THE LATE MORNING. NWLY GUSTS OF 25 KT EXPECTED THIS AFTERNOON. SCA CONTINUES FOR ALL BUT THE WESTERN TRIBUTARIES THROUGH THE EVENING FOR NLY CHANNELING FLOW WITH GUSTS AROUND 20 KT. FLOW ACTUALLY BECOMES SLY AFTER MIDNIGHT AS HIGH PRESSURE SETS UP OFFSHORE. WINDS WILL PICK BACK UP ON THU BUT NOT AS INTENSE AS WED...THOUGH SMALL CRAFT CONDITIONS WILL BE POSSIBLE - POTENTIALLY GALE. WINDS WILL DROP OFF FRI AND INTO THE WEEKEND W/ ONLY SOME BRIEF CHANNELING INTO EARLY NEXT WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR DCZ001. MD...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM EST THURSDAY FOR MDZ501. WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MDZ004>007- 009>011-013-014-016>018. VA...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM EST THURSDAY FOR VAZ503-504. WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ037>040- 042-050>057-501-502. WV...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM EST THURSDAY FOR WVZ501-503-505-506. WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ501-505. MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 11 PM EST THIS EVENING FOR ANZ530>534-537-539>541-543. SMALL CRAFT ADVISORY FROM 8 AM TO 6 PM EST THURSDAY FOR ANZ530>543. SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EST THIS EVENING FOR ANZ535-536-538-542. && $$ SYNOPSIS...BAJ NEAR TERM...BAJ SHORT TERM...GMS LONG TERM...GMS AVIATION...BAJ/GMS MARINE...BAJ/GMS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
246 AM EST WED FEB 26 2014 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL CROSS THE REGION THROUGH MIDDAY. LOW PRESSURE OVER THE GREAT LAKES WILL USHER IN CANADIAN AIR TO THE REGION THROUGH FRIDAY. A WEAK DISTURBANCE WILL SLIDE ACROSS THE AREA SATURDAY BEFORE A MORE POTENT LOW PRESSURE SYSTEM BEGINS TO AFFECT THE REGION EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... QUICK UPDATE TO ADD GREENE AND ALBEMARLE TO THE ADVISORY. NO SNOW REPORTED YET EAST OF THE ALLEGHENY FRONT THOUGH ECHOES SOUTH OF DC ARE MOISTENING THE COLUMN. 05Z HRRR CONTINUES TREND OF RECENT HOUR RUNS OF A SNOW MAX IN N-CNTRL VA CENTERED OVER CULPEPER COUNTY LOCAL AMOUNTS OF 5 INCHES. IT DOES NOT TAKE MUCH IN A COLD AIRMASS SUCH AS THIS TO GET SEVERAL INCHES FROM BANDS AND A WARNING MAY BE NECESSARY IN THE NOWCAST PHASE. ELSEWHERE...DEPICTION IS CONSISTENT OF A REDUCTION IN SNOW (LESS THAN AN INCH) BETWEEN THE ALLEGHENY FRONT AND BLUE RIDGE AND 1-3 INCHES FROM THE CENTRAL VA FOOTHILLS TO ACROSS THE BALTIMORE-WASHINGTON METRO AREA AND SRN MD PRIMARILY BETWEEN 10 TO 16Z. ADJUSTED BACK END OF PRECIP WITH FOR SCATTERED FLURRIES THAT CONTINUE THROUGH THE EARLY AFTERNOON. PREVIOUS... LATEST ANALYSIS SHOWS SHORTWAVE ENERGY RACING THROUGH IN A ZONAL FLOW ALOFT ACROSS THE MIDWEST INTO THE OHIO VALLEY. A STRONGER SHORTWAVE OVER THE UPPER MIDWEST WILL QUICKLY DROP SOUTHEAST AND SWING THROUGH OUR AREA LATE TONIGHT INTO WEDNESDAY MORNING. DEEP SYNOPTIC LIFT IS EXPECTED IN THE RIGHT REAR ENTRANCE OF THE UPPER- LEVEL JET...AND THIS CAN ALREADY BE SEEN IN THE INFRARED SATELLITE IMAGERY WITH COOLING CLOUD TOPS ACROSS THE MIDWEST AND OHIO VALLEY. RADAR TRENDS ARE ALSO INCREASING ACROSS THESE AREAS. CLOUDS WILL LOWER AND THICKEN OVERNIGHT AND SNOW IS EXPECTED TO OVERSPREAD THE AREA FROM WEST TO EAST AFTER MIDNIGHT. DESPITE LIMITED MOISTURE...FORCING SHOULD BE STRONG ENOUGH FOR SNOWFALL ACCUMULATIONS ACROSS MOST OF THE AREA. A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THE WASHINGTON AND BALTIMORE METROPOLITAN AREAS AS WELL AS THE VIRGINIA PIEDMONT AND SOUTHERN MARYLAND. LATEST GUIDANCE CONTINUES TO SHOW THAT THE BEST POTENTIAL FOR MESOSCALE BANDING EXISTS ACROSS THESE AREAS WITH POTENT FN VECTOR CONVERGENCE LINING UP WITH THE AREA OF MAXIMUM DENDRITIC SNOW GROWTH AND SATURATED CONDITIONS. SNOWFALL ACCUMULATIONS WILL AVERAGE BETWEEN ONE AND TWO INCHES ACROSS THESE AREAS...BUT LOCALLY HIGHER AMOUNTS AROUND THREE INCHES ARE POSSIBLE DUE TO THE POTENTIAL OF BANDING PRECIPITATION. TEMPS WILL BE PLENTY COLD FOR SNOW...RANGING FROM THE TEENS IN THE MOUNTAINS TO THE 20S ELSEWHERE EARLY WEDNESDAY MORNING. THEREFORE...SNOW COVERED ROADS AND SLIPPERY CONDITIONS ARE EXPECTED DURING THE MORNING RUSH. A WINTER WEATHER ADVISORY IS ALSO IN EFFECT FOR PORTIONS OF WEST VIRGINIA ALONG AND WEST OF THE ALLEGHENY FRONT DUE TO AN UPSLOPE COMPONENT TO THE LOW-LEVEL FLOW. HIGH PRESSURE WILL APPROACH THE AREA WEDNESDAY AFTERNOON...BUT BLUSTERY AND COLD CONDITIONS ARE EXPECTED AS NORTHWEST WINDS INCREASE DUE TO A STRENGTHENING GRADIENT BETWEEN THE APPROACHING HIGH AND LOW PRESSURE DEVELOPING WELL OF THE MID-ATLANTIC COAST. FLURRIES ARE POSSIBLE WEDNESDAY AFTERNOON AS COLD ADVECTION COMBINING WITH THE HIGHER SUN ANGLE CAUSES SOME INSTABILITY. HOWEVER...NO ADDITIONAL SNOWFALL ACCUMULATION IS EXPECTED. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... COLD HIGH PRESSURE WILL BUILD INTO THE MIDDLE ATLANTIC REGION WEDNESDAY NIGHT. GUSTY NORTHWEST WINDS WILL DIMINISH AND TEMPERATURES WILL FALL BACK INTO THE TEENS IN MOST AREAS EXCEPT 0 TO 5 ABOVE ACROSS THE ALLEGHENY FRONT. HIGH TEMPERATURES WILL AVERAGE WELL BELOW NORMAL THURSDAY AFTERNOON WITH ANOTHER COLD FRONT BRINGING A REINFORCING SHOT OF ARCTIC AIR THURSDAY AFTERNOON/EVENING. OVERNIGHT LOWS THURSDAY NIGHT WILL FALL BACK TO THE LOWER TO MIDDLE TEENS AREA WIDE EXCEPT 0 ABOVE TO 5 BELOW ZERO ACROSS THE ALLEGHENY FRONT. GUSTY NORTHWEST WINDS MAY LEAD TO A PERIOD OF BELOW ZERO WIND CHILLS THURSDAY NIGHT OVER WESTERN SECTIONS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... HIGH PRESSURE WILL MOVE ACROSS THE REGION FRIDAY...MAKING IT TO THE EAST COAST BY FRIDAY NIGHT. WINDS WILL BE LIGHT AND VARIABLE FRIDAY THEN BECOME SOUTHERLY FRIDAY NIGHT. TEMPERATURES WILL BE ABOUT 15 TO 20 DEGREES BELOW NORMAL FRIDAY AND 5 TO 10 DEGREES BELOW NORMAL FRIDAY NIGHT. SOME UPPER LEVEL ENERGY WILL BRING A CHANCE FOR SOME RAIN OR SNOW SHOWERS LATE FRIDAY NIGHT AND SATURDAY. A STATIONARY FRONT WILL DEVELOP ALONG THE OHIO VALLEY AND INTO THE MID-ATLANTIC REGION SUNDAY AND PERSIST INTO MONDAY. THIS FRONT WILL BE THE FOCAL POINT OF RAIN OR SNOW...MAINLY SUNDAY NIGHT AND MONDAY. THE EURO MODEL HAS A LOW PRESSURE SYSTEM FORMING ALONG THIS FRONT AND MOVING NORTHEAST ALONG THE SHENANDOAH VALLEY TOWARD PENNSYLVANIA AND NEW YORK. THE GFS MODEL HAS A LOW PRESSURE SYSTEM FORMING ALONG THE FRONT...AS WELL...BUT TAKES THE LOW FURTHER SOUTH AND EAST THAN THE ECMWF. THESE DIFFERENCES MAKE IT DIFFICULT TO PINPOINT WHO WILL RECEIVE RAIN AND WHO WILL RECEIVE SNOW. THERE IS AT LEAST A CHANCE OF EITHER PRECIPITATION TYPE WITH A LIKELY POP OF RAIN OR SNOW MONDAY. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... CIGS/VSBYS WILL DETERIORATE EARLY WEDNESDAY MORNING AS BANDS OF SNOW DEVELOP OVER THE TERMINALS. IFR CONDITIONS ARE EXPECTED DURING THIS TIME. CIGS/VSBYS WILL IMPROVE LATE WEDNESDAY MORNING AND AFTERNOON AS NORTHWEST WINDS USHER IN DRIER CONDITIONS. HOWEVER...A FEW FLURRIES CANNOT BE RULED OUT WEDNESDAY AFTERNOON. NORTHWEST WINDS WILL GUST AROUND 20 TO 25 KNOTS DURING THIS TIME. VFR CONDITIONS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. GUSTY NORTHWEST WINDS OF 15 TO 25 KTS WILL IMPACT THE TERMINALS THURSDAY AFTERNOON INTO THE EVENING. WINDS WILL DIMINISH DURING THE NIGHT. VFR CONDITIONS FRIDAY. MVFR CONDITIONS CAN`T BE RULED OUT WITH A CHANCE OF RAIN OR SNOW FRIDAY NIGHT THROUGH MONDAY. IF IFR CONDITIONS DO EXIST...THERE IS A BETTER CHANCE SUNDAY NIGHT INTO MONDAY ALONG A STATIONARY FRONT AND A DEVELOPING LOW PRESSURE SYSTEM. && .MARINE... A SHORTWAVE WILL PASS THROUGH THE WATERS WEDNESDAY MORNING...TRIGGERING A PERIOD OF SNOW. NW FLOW 15-20 KT SUSTAINED BEHIND THE FRONT. SCA IN EFFECT FOR WED...CONTINUING FOR NLY FLOW OVER ALL BUT THE WRN TRIBS WEDNESDAY EVENING. A COLD FRONT WILL PUSH THROUGH THE WATERS ON THURSDAY BRINGING THE LIKELIHOOD OF SCA CONDITIONS TO ALL OF THE WATERS. WINDS WILL FALL BELOW SCA LEVELS BY THURSDAY NIGHT. NO MARINE HAZARDS EXPECTED FRIDAY THROUGH SUNDAY. SMALL CRAFT ADVISORIES SUNDAY NIGHT AND MONDAY WOULD DEPEND ON THE POSITION OF A STATIONARY FRONT AND THE TRACK OF AN ATTACHED LOW PRESSURE SYSTEM. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR DCZ001. MD...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MDZ004>007- 009>011-013-014-016>018. VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ037>040- 042-050>057-501-502. WV...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ501-505. MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 11 PM EST THIS EVENING FOR ANZ530>534-537-539>541-543. SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EST THIS EVENING FOR ANZ535-536-538-542. && $$ UPDATE...JACKSON PREVIOUS...BJL/KRW/KLW/HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 AM EST WED FEB 26 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 400 PM EST TUE FEB 25 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAMILIAR PATTERN FEATURING A DEEP UPR TROF OVER ERN NAMERICA DOWNSTREAM OF A RDG ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW IS STREAKING SEWD THRU ONTARIO JUST N OF LK SUP. COLD FNT ASSOCIATED WITH THIS DISTURBANCE HAS PASSED THRU THE CWA...AND H85 TEMPS AS LO AS -25C TO -28C ARE PUSHING INTO UPR MI IN THE LLVL W FLOW. ALTHOUGH THERE IS A GOOD DEAL OF ICE ON LK SUP...AREAS OF OPEN WATER OVER THE FAR WRN LK AND OVER THE SCENTRAL E OF THE KEWEENAW HAVE ALLOWED A GOOD DEAL OF LK CLD/SOME -SHSN TO FORM IN THE LLVL CAD. THE LK CLDS/SHSN APPEAR TO BE MOST WDSPRD OVER THE NE HALF OF THE AREA CLOSER TO THE SHRTWV PASSING THRU ONTARIO/ACCOMANPANYING DYNAMIC SUPPORT AND DEEPER MSTR. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LK EFFECT CLD/SHSN TRENDS AND TEMPS/NEED FOR WIND CHILL HEADLINES. LATE THIS AFTN/TNGT...AS THE H925 FLOW VEERS MORE TO THE NW THRU 00Z IN THE WAKE OF SHRTWV PASSING BY TO THE N...EXPECT LK EFFECT CLDS/SHSN TO SPREAD FARTHER TO THE S AND INLAND IN THE PRESENCE OF LENGTHENING DAYTIME HEATING DESPITE DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF THE SHRTWV PASSAGE. H85 THERMAL TROF WITH TEMPS DOWN TO -28/-29C IS FCST TO SHIFT THRU THE CWA BTWN 06Z-12Z AS THE LLVL FLOW BACKS TO THE W BTWN SFC HI PRES SINKING TOWARD THE MID MS RIVER VALLEY AND NEXT VIGOROUS SHRTWV DROPPING SEWD THRU SCENTRAL CANADA. WITH A PERIOD OF LARGER SCALE QVECTOR DVGC...EXPECT CLRG OVER THE INTERIOR...ALLOWING SFC TEMPS TO FALL WELL BLO ZERO AND INTO THE TEENS BLO ZERO AT SOME PLACES UNDER DRY AIRMASS WITH PWAT UNDER 0.10 INCH. ALTHOUGH THERE ARE QUESTIONS AS TO WHETHER SFC WINDS WL CONSISTENTLY SATISFY THE 10 MPH SPEED THRESHOLD FOR A WIND CHILL ADVY...PLAN TO ISSUE AN ADVY FOR THE COLDER NW HALF OF THE CWA WITH FAIRLY SHARP PRES GRADIENT/H925 WINDS IN THE 20-30KT RANGE UNDER H85 THERMAL TROF ENHANCING MIXING. LK EFFECT CLDS/-SHSN WL SHIFT FM THE NW WIND SN BELTS BACK INTO AREAS IMPACTED BY W WINDS LATE TNGT. ABSENCE OF DGZ WITHIN VERY COLD AIRMASS AND ICE COVER WL LIMIT SN ACCUMS. WED...AREA OF DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV/SFC LO DIGGING SEWD THRU NW ONTARIO WL OVERSPREAD UPR MI NW-SE BY EARLY AFTN. IN THE ABSENCE OF ANY SGNFT MSTR INFLOW...SUSPECT DRYNESS OF ANTECEDENT AIRMASS WL BE A SGNFT IMPEDIMENT TO OUTBRREAK OF PCPN. AS THE FLOW SHIFTS TO THE SW...THERE IS POTENTIAL FOR SOME LK MOISTENING/ENHANCEMENT OFF OF LK MI. BUT EXTENSIVE/GROWING ICE COVER OVER THE N HALF OF LK MI WL TEND TO MITIGATE THIS IMPACT. TENDED TOWARD THE HIER CHC/LIKELY POPS OVER THE NE HALF OF THE CWA TOWARD SHARPER ISENTROPIC ASCENT ON THE 270K SFC /NEAR H7/ AND ALSO LATE IN THE DAY OVER THE W WITH EXPECTED ARRIVAL OF ENHANCED LLVL CNVGC ASSOCIATED WITH COLD FNT ATTENDANT TO CLIPPER LO REACHING NE LK SUP BY 00Z THU. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 416 AM EST WED FEB 26 2014 AT 12Z THURSDAY THE MAIN 500MB LOW WILL BE SET UP FROM S HUDSON BAY THROUGH N LAKE HURON...WITH QUICK NW FLOW AND SEVERAL ELONGATED DISTURBANCES STILL MOVING THROUGH UPPER MI. THE STRONG WINDS THAT WILL STILL BE AROUND AT DAYBREAK THURSDAY ARE STILL EXPECTED TO DIMINISH PRETTY QUICKLY DURING THE DAY...WITH THE WEAKENING PRESSURE GRADIENT AS THE SFC LOW PUSHES ACROSS THE S ONTARIO/QUEBEC BORDER BY 18Z...AND THE STRONG HIGH OVER THE DAKOTAS SHIFTS TO MN AND IA WHICH WILL ALLOW FOR RIDGING OVER THE W HALF OF THE CWA. MOMENTUM TRANSFER FALLS BELOW 25KTS AT IWD AROUND 15Z...CMX AT 18Z...1-2HRS LATER AT SAW...AND AROUND 21Z AT P53. WIND CHILL WARNINGS/ADVISORIES WILL CONTINUE UNTIL 17 OR 18Z. CONFIDENCE IN HIGH SNOW AMOUNTS TO POST ANYTHING MORE THAN WINTER WEATHER ADVISORIES IS LOW GIVEN THE SIGNIFICANT ICE ACROSS LAKE SUPERIOR. HAS BEEN AMAZING TO SEE HOW QUICKLY NEW ICE HAS BEEN ABLE TO FORM IN OUR COLD AIR OVER THE PAST 24HRS. WINTER WEATHER ADVISORY WILL LINGER THROUGH MID-LATE MORNING ACROSS THE KEWEENAW PENINSULA...AND MID AFTERNOON FOR ALGER/N. SCHOOLCRAFT/LUCE COUNTIES. MAY NEED TO INCORPORATE FAR N AND E MQT COUNTY INTO WINTER WEATHER ADVISORY FOR BLOWING/DRIFTING SNOW. THE WORST CONDITIONS ON M-26 BETWEEN MQT AND MUNISING WILL LIKELY BE 10-18Z THURSDAY. RECORD BREAKING LOW-HIGH TEMPERATURES THURSDAY STILL LOOK REASONABLE. 850MB TEMPS OF -30 TO -33C WILL LINGER OVERHEAD THROUGH THE DAY...WITH -36 TO -38C OVER CENTRAL ONTARIO. AS NOTED IN PREVIOUS DAYS...THESE VALUES ACROSS THE CWA ARE SIMILAR TO 850MB TEMPS FROM JANUARY 27TH AND HIGHS THAT DAY WERE IN THE SINGLE DIGITS BELOW ZERO OVER THE WEST...AND AT OR JUST ABOVE FREEZING OVER THE EAST. ALL-TIME COLDEST HIGH TEMP RECORDS FOR FEB 27TH ARE GENERALLY IN THE MID SINGLE DIGITS ABOVE ZERO (WITH AT LEAST 6 DATING BACK BEFORE 1925). LOOK FOR EXTREMELY COLD TEMPERATURES THURSDAY NIGHT AS THE SFC HIGH SINKS TO S WI AND IL BY 00Z...OVER LOWER MI THROUGH THE OHIO VALLEY AT 06Z FRIDAY...AND FINALLY ACROSS THE LOWER GREAT LAKES/MID ATLANTIC BY 12Z FRIDAY. WITH THE SFC RIDGE OVERHEAD MOST OF THE NIGHT...EXPECT LIGHT WINDS. CLOUDS COULD KEEP TEMPS FROM FALLING TOO LOW...PARTICULARLY OVER THE N HALF OF THE CWA. THE GFS AND NAM STILL HAVE PLENTY OF LLV MOISTURE STUCK BELOW 850MB...WITH ADDITIONAL MID CLOUDS LIKELY SLIDING IN OVERNIGHT FROM THE W OVER THE FAR N. THE BAND OF MID CLOUDS S WILL LIKELY REMAIN JUST TO THE S THROUGH 12Z FRIDAY. ALTHOUGH TEMPERATURES WILL BE VERY LOW /ONCE AGAIN POSSIBLY RECORD BREAKING/...WIND CHILLS WILL NOT BE AS LOW...AND WARNINGS/ADVISORIES WILL LIKELY NOT BE POSTED DUE TO THE LIGHT WINDS. THE CHANCES FOR LIGHT SNOW WILL GREATLY DIMINISH THURSDAY NIGHT INTO EARLY FRIDAY...BEFORE THE NEXT SYSTEM SLIDES IN FROM THE W-SW WITH SCATTERED SNOW/SNOW SHOWERS DEVELOPING OVER MAINLY CENTRAL/E UPPER MI DURING THE DAY FRIDAY. EXPECT S-SSW WINDS AHEAD OF THE LOW SHIFTING FROM THE PLAINS STATES AT 12Z FRIDAY WILL DEEPEN SLIGHTLY AS IT PUSHES ACROSS W UPPER MI/LAKE SUPERIOR AT 00Z SATURDAY...AND E OF LAKE SUPERIOR/UPPER MI BY 12Z SATURDAY. THE S-SSW SHOULD RESULT IN LAKE ENHANCED SNOW E OF ESC ALONG LAKE MI FRIDAY AFTERNOON/FRIDAY EVENING. WILL NOT GO TOO HIGH WITH POPS AT THIS TIME...BUT POPS MAY NEED TO BE INCREASED S CENTRAL AND E ALONG THE LAKE MI BORDER AS FCST MODELS ARE STARTING TO ALIGN TO A COMMON THEME. LITTLE TO NO SNOW IS EXPECTED FAR W. STRONGER HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS SATURDAY WILL SLOWLY SLIDE OVER THE UPPER GREAT LAKES THROUGH MUCH OF THE REST OF THE PERIOD. LAKE EFFECT SNOW SHOWERS ACROSS N UPPER MI WILL GREATLY DEPEND ON THE AMOUNT OF ICE COVER...BUT WITH SIGNIFICANT ICE LIKELY REMAINING...KEPT POPS MAINLY IN THE SLIGHT CHANCE CAT THROUGH THE REST OF THE PERIOD. NO SIGNIFICANT WARM UP EXPECTED TO NORMAL VALUES ANTICIPATED. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 634 PM EST TUE FEB 25 2014 WINDS BEGINNING TO ABATE SLIGHTLY AT ALL THREE TAF SITES THIS EVENING. WINDS ARE TO GRADUALLY DIMINISH OVERNIGHT AS THEY BACK TO THE SSW/SW BY DAYBREAK...AND THEN WILL PICK UP AS THE MORNING PROGRESSES...WITH GUSTS TO 22-23KTS COMMON DURING THE LATE MORNING AND AFTERNOON HOURS. AT KCMX...LIFR/IFR VISIBILITIES DUE TO BRIEF LES SNOW BANDS AND GUSTY WINDS CHANNELED THROUGH THE TERRAIN THERE WILL EVENTUALLY IMPROVE AFTER 6Z AS WINDS DIMINISH AND DRIER AIR WORKING IN FROM THE WEST DIMINISHES LES. OTHERWISE...MVFR/VFR CONDITIONS PREVAIL AT KIWD AND KSAW WITH MVFR DEVELOPING AT KCMX BY 9Z...AND WILL CONTINUE THROUGH THE FORECAST. IFR VISIBILITY CONDITIONS MAY REDEVELOP AT KCMX WEDNESDAY AFTERNOON AS WINDS SHIFT BACK TO THE WEST AND PICK UP AND LES REDEVELOPS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 PM EST TUE FEB 25 2014 NW WINDS UP TO 25-30 KTS LATE TODAY UNDER SHARP PRES GRADIENT BETWEEN SFC HI OVER THE NCENTRAL PLAINS AND LO PRES IN EASTERN ONTARIO WILL SLOWLY BACK TO THE SW ON WED AS THE HI MOVES INTO THE MID MS RIVER VALLEY AND ANOTHER LO PRES SYSTEM DIVES SE INTO NW ONTARIO. THERE MAY BE SOME GALE FORCE GUSTS TO 35 KTS OVER THE W HALF OF THE LAKE WHERE FUNNELING OF THIS FLOW RESULTS IN SPEED ENHANCEMENT. ONCE THE LO SHIFTS TO THE E OF THE LAKE ON WED NIGHT AS THE PRES GRADIENT TIGHTENS AGAIN E OF HI PRES MOVING INTO THE NORTHERN PLAINS...N GALES UP TO 35-45 KTS WILL DEVELOP OVER THE ENTIRE LAKE. THE CLOSER APPROACH OF THE HI CENTER AND WEAKER PRES GRADIENT WILL CAUSE THE GALES TO DIMINISH W TO E ON THU. ISSUED A GALE WATCH FOR THE ENTIRE LAKE. EXPECT WINDS UNDER 25 KTS THE REST OF THE FORECAST PERIOD WITH A RELATIVELY WEAK PRES GRADIENT DOMINATING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WIND CHILL WARNING FROM 3 AM EST /2 AM CST/ TO NOON EST /11 AM CST/ THURSDAY FOR MIZ001>005-009>011-084. WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS MORNING FOR MIZ001>005-009>011-084. WINTER WEATHER ADVISORY FROM 2 AM TO 3 PM EST THURSDAY FOR MIZ006-007-085. WIND CHILL ADVISORY FROM 6 AM EST /5 AM CST/ TO NOON EST /11 AM CST/ THURSDAY FOR MIZ006-007-012>014-085. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST THURSDAY FOR MIZ001-003. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 1 PM EST THURSDAY FOR LSZ243>245- 248>251-264>267. GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 8 AM EST /7 AM CST/ THURSDAY FOR LSZ240>242-263. GALE WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 6 AM EST /5 AM CST/ THURSDAY FOR LSZ162. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...RJT MARINE...KC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
349 AM EST WED FEB 26 2014 .SYNOPSIS... A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING 10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 342 AM EST WEDNESDAY...VARIABLE CLOUD COVER...WIND AND WEATHER CONDITIONS TODAY WITH REINFORCING ARCTIC FRONTAL PASSAGE FROM WEST-TO-EAST EXPECTED LATER THIS MORNING. EXCELLENT CONVERGENCE NOTED ALONG APPROACHING SECONDARY/ARCTIC FRONT ACROSS ERN LAKE ONTARIO AND WRN NY EARLY THIS AM. EARLY AM RUC MODEL ANALYSIS INDICATES THE FRONT IS ASSOCIATED WITH STRONG SFC-925MB FRONTOGENESIS WITH ACCOMPANYING ISALLOBARIC RISE/FALL COUPLET...RESULTING IN ROBUST LINEAR FORCING. LAKE INDUCED INSTABILITY UP TO 100 J/KG AND STRONG LOW-LEVEL FORCING FOR ASCENT IS RESULTING IN NARROW CONVECTIVE BAND ALONG THE FRONT PRODUCING SNOW SQUALL ACTIVITY WITH BRIEF PERIOD OF MODERATE TO HEAVY SNOW (20-30 MINUTES). BTV SNOW SQUALL PARAMETER MAINTAINS SNOW SQUALL POTENTIAL AS FRONT SHIFTS EWD CROSSING OUR REGION THIS MORNING...BEFORE EXITING EAST OF THE CT RIVER VLY BY 18Z. FAVORABLE FRONTOGENETIC FORCING AND LOW-LEVEL MOISTURE AND INSTABILITY WILL BRING A BAND OF SNOW SHOWERS AND SQUALLS ACROSS NRN NY THRU ABOUT 12-13Z. MAY SEE CONVECTIVE ACTIVITY WEAKEN SLIGHTLY THRU THE CHAMPLAIN VALLEY WITH ABSENCE OF INSTABILITY LOCALLY AND FLOW DISRUPTION ACROSS THE ADIRONDACK REGION. INSTABILITY IS ACTUALLY BEST ACROSS NH/ME WITH INSOLATIONAL HEATING IN ADVANCE OF THE BNDRY...SO AGAIN...ANTICIPATE ORGANIZATION MAY WANE A BIT THRU THE CHAMPLAIN VLY...BUT INCREASE AGAIN ACROSS ERN VT MIDDAY HRS BEFORE EXITING RAPIDLY EWD WITH FROPA BY 17-18Z. SBCAPE VALUES REACH 100-150 J/KG IN NAM MODEL SOUNDINGS ALONG THE CT RIVER BETWEEN 15-18Z TODAY JUST AHEAD OF THE FRONTAL BNDRY. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS WITH THESE SNOW SHOWERS AND SQUALLS...LIKELY HIGHEST IN NRN NY AND THEN CENTRAL AND ERN VT. MAY RESULT IN SLOW TRAVEL FOR AN HOUR OR SO DURING SQUALL PASSAGE. WE/LL CONTINUE TO HIGHLIGHT THIS POTL IN THE HAZARDOUS WEATHER OUTLOOK AND THROUGH SOCIAL MEDIA. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID TO UPPER 20S...EXCEPT LOW 20S IN FAR SERN SECTIONS. STEEP LOW- LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF NEXT SYSTEM. NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY 15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE. FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY 8-9F IN THE NRN ADIRONDACK REGION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY. TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS. MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED 5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT APPROACHING THE OTTAWA VALLEY AND EXTENDING SOUTH ACRS CENTRAL LAKE ONTARIO...WITH A NARROW BAND OF ENHANCED SNOW SHOWER ACTIVITY WITH VIS <1/2SM. USING THE DISTANCE TIME TOOL IN AWIPS AND LATEST HRRR/RAP DATA SHOWS THIS BAND IMPACTING MSS BTWN 09Z-10Z...SLK BTWN 10-12Z...AND INTO THE CPV BY 12Z. A BRIEF 20 TO 30 MINUTE WINDOW OF IFR/LIFR CONDITIONS WITH VIS BLW 1SM IN SNOW SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE WEST...ESPECIALLY AT MSS. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL OCCUR AFT 12Z AT BTV/MPV AND RUTLAND. IN ADDITION...THE COMBINATION OF UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 12Z THIS MORNING AT SLK. ALSO...CANNOT RULE OUT POTENTIAL FOR -SHSN AT MPV WITH BRIEF PERIODS OF IFR/MVFR CONDITIONS BEFORE FROPA THIS MORNING. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15 KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY BTWN 12Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET THIS EVENING. OUTLOOK 06Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN 06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH ADDITIONAL LIGHT SNOW SHOWERS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS SHORT TERM...BANACOS LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
314 AM CST WED FEB 26 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST WED FEB 26 2014 THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID MORNING INTO THE AFTERNOON. EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES. FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35 BELOW. WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES. WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO 1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY. IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER. WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS WILL HAVE TO CONSIDER THAT POSSIBILITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 26 2014 WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND. SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM RANGE MODELS MAINTAIN A DRY FROPA. WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT. THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY. THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 314 AM CST WED FEB 26 2014 VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. THE MAIN CONCERN WILL BE INCREASING WINDS AS NORTHWEST WINDS INCREASE BY MID MORNING WEDNESDAY AND CONTINUE INTO THE AFTERNOON. CURRENTLY IT LOOKS LIKE THE STRONGEST WINDS WILL PREVAIL FROM KMOT- KJMS...THOUGH ALL LOCATIONS WILL SEE WINDS BECOME GUSTY. HELD ONTO THE 6SM IN BLSN FOR KMOT AND KJMS ONCE THE WINDS INCREASE. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ001>005- 009>013-021>023-025-035>037-046>048-050-051. WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING FOR NDZ004-005-012-013-022-023-025-037-048-051. && $$ SHORT TERM...CK LONG TERM...TM AVIATION...CK
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1246 AM CST WED FEB 26 2014 .UPDATE... HAVE ISSUED A DENSE FOG ADVISORY FOR COASTAL COUNTIES. NEW ZONES OUT SHORTLY. 23 && .PREV DISCUSSION... /ISSUED 1147 PM CST TUE FEB 25 2014/ DISCUSSION... 06Z AVIATION DISCUSSION BELOW. AVIATION... PREVIOUS 00Z THINKING STILL HOLDS TRUE WITH THIS LATEST SET OF TAFS. THAT BEING OF PRIMARILY VLIFR TO IFR DECKS WITH PERIODIC SHOWERS AND STRENGTHENED NORTHERLIES...ANOTHER ROUND OR TWO OF HIGHER AREAL PRECIPITATION COVERAGE IN THE PREDAWN HOURS AND LATER WEDNESDAY AFTERNOON FROM THE PASSAGE OF WEAK WESTERLY IMPULSES. IN BETWEEN THESE SHORTWAVES...A POST-FRONTAL ENVIRONMENT CONDUCIVE TO THE DEVELOPMENT OF EITHER LIGHT RAIN/DRIZZLE/MIST AT THE TERMINAL TO PASSING VICINITY SHOWERS WITHIN 10 NM OF MOST REGIONAL HUBS. JUST KEPT IT RAIN THROUGH TOMORROW EVENING...WITH ANY CONVECTION REMAINING ELEVATED...PER THE COOLING SURFACE AND WARMER ALOFT PROFILES BROUGHT ON BY THE LOWER LEVEL COLD AIR ADVECTION. 31 PREV DISCUSSION... /ISSUED 930 PM CST TUE FEB 25 2014/ DISCUSSION... CURRENT FORECAST IS IN GOOD SHAPE. NO UPDATE IS PLANNED FOR THE OVERNIGHT HOURS. WILL WAIT FOR ALL OF THE 00Z MODELS TO ARRIVE BEFORE ANY SIGNIFICANT CHANGES ARE MADE TO OUR RAIN CHANCES...WINDS AND TEMPERATURES. COLD FRONT IS SLOWLY WORKING ITS WAY THROUGH SOUTHEAST TEXAS THIS EVENING...APPROACHING THE I-10 CORRIDOR AT AROUND 9 PM. AREAS OF RAIN WITH EMBEDDED SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS THE AREA...AND MODELS INDICATE THIS SHOULD CONTINUE OVERNIGHT AND ON INTO TOMORROW MORNING (SOME SPOTS WITH THE HEAVIER STORMS HAVE ALREADY RECEIVED 1 TO 2 INCHES). TEMPERATURES ARE IN THE LOW TO MID 50S BEHIND THE FRONT UP NORTH...AND EXPECT THIS COOLER AIR TO WORK ITS WAY TOWARD THE COAST OVERNIGHT. 42 PREV DISCUSSION... /ISSUED 609 PM CST TUE FEB 25 2014/ DISCUSSION... 00Z AVIATION DISCUSSION BELOW. AVIATION... THE SHORT TERM FORECAST...OR THROUGH THE EARLY WEDNESDAY MORNING HOURS...WILL BE FOR INTERMITTENT SHOWERS WITH A ISOLATED STORM AND STRENGTHENED NORTH WIND BEHIND AN EVENING COLD FRONTAL PASSAGE. THE MAIN IMPULSE DRIVING THIS ONGOING WIDELY SCATTERED -SHRA (ISO -TSRA) IS TRAVELING ACROSS NORTHERN TEXAS THIS EVENING WITH THE ONLY TRIGGERS LEFT OVER IN THIS HIGHLY-MOIST ENVIRONMENT FOR REPEAT PRECIPITATION BEING ANOTHER EASTERN PASSING SHORTWAVE RIPPLE WITHIN THE WESTERLY FLOW AND/OR THE ENHANCED POST-FRONTAL ISENTROPIC UPGLIDE AS SOUTHWESTERLY MID-UPPER FLOW RIDES UP AND OVER A PUMPED UP NORTH-NORTHEAST LOWER LEVEL WIND. BETTER UPPER DIFFULENCE BY TOMORROW AFTERNOON AS SE TX FALLS UNDER AN EXITING RRQ JET. CONSIDERING THE ABOVE ELEMENTS AND...EVEN WITH NWP MODELING NOT PROVIDING MUCH GUIDANCE UP TO NOW...STILL BELIEVE THAT ALL WILL COME IN-LINE FOR BETTER OVERALL (LIGHT) RAIN COVERAGE. PROBABLY NOT AN ALL-DAY RAIN EVENT...BUT GT 50% OF THE TIME THERE WILL BE THAT PASSING SHOWER...BRIEF MODERATE RAINFALL ASSOCIATED WITH STRONGER CELLS WEDNESDAY AFTERNOON...BUT THERE WILL ALSO BE LONGER PERIODS OF A JUST A LIGHT MIST AND/OR DRIZZLE ALONG WITH THOSE PESKY FLUCTUATING DECKS FROM IFR TO MVFR AND VICE VERSA. 31 PREV DISCUSSION... /ISSUED 333 PM CST TUE FEB 25 2014/ DISCUSSION... FRONT IS NOW PUSHING INTO NRN PORTIONS OF SE TX. SHOULD BE BETWEEN I-10 AND THE COAST AROUND MIDNIGHT AND OFF THE BEACHES BY 4AM (EFFECTIVELY ENDING SEA FOG ISSUES FOR A FEW DAYS). STARTING TO SEE SOME SCT PRECIP DEVELOP ACROSS S PARTS OF THE AREA AND EXPECT IT TO GRADUALLY INCREASE IN COVERAGE AHEAD OF, AND ESPECIALLY BEHIND, THE FRONT. HRRR MODEL AND TO A DEGREE NAM12 HAS DONE FAIRLY WELL WITH RAINFALL DEPICTION (OR LACK THEREOF) SO FAR TODAY AND SHORT TERM FCST WAS TRENDED THAT WAY. GFS/ECMWF HAVE BEEN HORRIBLY OVERDONE BOTH IN COVERAGE & AMOUNTS UP TO THIS TIME. PERIODS OF PRECIP WILL LIKELY CONTINUE THRU WED IN ASSOCIATION WITH H85 FRONT AND UPPER IMPULSES RIDING FURTHER OVERHEAD IN THE WRLY FLOW ALOFT. CONSIDERING STRONG CAA...CLOUDINESS AND PRECIP THE HIGHS FOR THE 24 HOUR PERIOD WILL OCCUR AROUND MIDNIGHT FOLLOWED BY FALLING AND/OR STEADY TEMPS IN THE 40S WED. RAIN SHOULD TAPER OFF WED EVENING. COOL WX CONTINUES THURS BUT ONSHORE WIND WILL BE RESUMING AS HIGH PRES MOVES EAST AND NEXT SHORTWAVE STARTS DIGGING SEWD DOWN THE 4-CORNERS AREA. THIS DISTURBANCE ISN`T AS IMPRESSIVE AS PREVIOUS DAYS AND DON`T ANTICIPATE MUCH OF AN IMPACT HERE AS IT MOVES ALONG THE RED RIVER FRIDAY...AS BEST ENERGY WILL BE WELL NORTH AND A CAP SHOULD BE IN PLACE. FURTHER LOWERED POPS. WARMING TREND CONTINUES THRU THE WEEKEND WITH ONSHORE FLOW IN PLACE. APPEARS THAT WE`LL PROBABLY HAVE ANOTHER COASTAL FOG EVENT BUT LOOKS LIKE MARDI GRAS PARADES SHOULD OTHERWISE BE DRY PRIOR TO MID TO LATE SUNDAY AFTN. NEXT STORM SYSTEM APPROACHES FROM THE WEST LATE IN THE WEEKEND AND KEPT 20-40% POPS IN PLACE SUN AFTN/NIGHT AHEAD OF THE NEXT FRONT THAT`LL BE MOVING THRU SUNDAY NIGHT OR MONDAY. KNOCKED TEMPS DOWN EARLY NEXT WEEK (MAYBE NOT ENOUGH) AS 1040+MB HIGH DROPS INTO THE PLAINS. 47 MARINE... SEA FOG WILL CONTINUE OVER THE GULF WATERS THIS AFTERNOON. AM EXPECTING THE FOG TO REDEVELOP AND BECOME DENSE OVER THE BAYS LATER THIS AFTERNOON AND EVENING. THE FOG WILL CLEAR OUT BETWEEN MIDNIGHT AND SUNRISE AS A COLD FRONT PUSHES THROUGH THE BAYS AND OFF THE COAST. THE MODELS HAVE BEEN FAIRLY CONSISTENT THE PAST FEW DAYS AND AM FAIRLY CONFIDENT ON THE TIMING. EXPECT THE FRONT TO MOVE THROUGH THE BAYS BY AROUND 3 AM AND THEN BEYOND 20 NM OFFSHORE BY 4 AM. THE 12Z MODEL RUN AND GUIDANCE FROM THIS MORNING FORECASTED SLIGHTLY HIGHER WINDS...INDICATING THAT SMALL CRAFT ADVISORIES ARE LIKELY FOR THE GULF WATERS AND MATAGORDA BAY. WOULD NOT BE SURPRISED IF WINDS INCREASE TO BETWEEN 20 AND 25 KNOTS FOR AT LEAST MOST OF THE LOWER PART OF GALVESTON BAY...ALSO. EXPECT THE NORTHEASTERLY WINDS TO DIMINISH WEDNESDAY NIGHT AND THURSDAY. ANOTHER FOG EVENT MAY DEVELOP BY LATE THIS WEEK AS ONSHORE REDEVELOPS. && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 43 33 57 42 70 / 60 20 10 10 10 HOUSTON (IAH) 49 36 59 43 69 / 70 30 10 10 10 GALVESTON (GLS) 54 42 55 53 66 / 60 40 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY UNTIL 4 AM CST EARLY THIS MORNING FOR THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON... MATAGORDA. GM...DENSE FOG ADVISORY UNTIL 4 AM CST EARLY THIS MORNING FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM... WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO NOON CST TODAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT SHOULD EXERCISE CAUTION FROM NOON CST TODAY THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY... MATAGORDA BAY. SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT SHOULD EXERCISE CAUTION FROM THIS EVENING THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. SMALL CRAFT SHOULD EXERCISE CAUTION LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1147 PM CST TUE FEB 25 2014 .DISCUSSION... 06Z AVIATION DISCUSSION BELOW. && .AVIATION... PREVIOUS 00Z THINKING STILL HOLDS TRUE WITH THIS LATEST SET OF TAFS. THAT BEING OF PRIMARILY VLIFR TO IFR DECKS WITH PERIODIC SHOWERS AND STRENGTHENED NORTHERLIES...ANOTHER ROUND OR TWO OF HIGHER AREAL PRECIPITATION COVERAGE IN THE PREDAWN HOURS AND LATER WEDNESDAY AFTERNOON FROM THE PASSAGE OF WEAK WESTERLY IMPULSES. IN BETWEEN THESE SHORTWAVES...A POST-FRONTAL ENVIRONMENT CONDUCIVE TO THE DEVELOPMENT OF EITHER LIGHT RAIN/DRIZZLE/MIST AT THE TERMINAL TO PASSING VICINITY SHOWERS WITHIN 10 NM OF MOST REGIONAL HUBS. JUST KEPT IT RAIN THROUGH TOMORROW EVENING...WITH ANY CONVECTION REMAINING ELEVATED...PER THE COOLING SURFACE AND WARMER ALOFT PROFILES BROUGHT ON BY THE LOWER LEVEL COLD AIR ADVECTION. 31 && .PREV DISCUSSION... /ISSUED 930 PM CST TUE FEB 25 2014/ DISCUSSION... CURRENT FORECAST IS IN GOOD SHAPE. NO UPDATE IS PLANNED FOR THE OVERNIGHT HOURS. WILL WAIT FOR ALL OF THE 00Z MODELS TO ARRIVE BEFORE ANY SIGNIFICANT CHANGES ARE MADE TO OUR RAIN CHANCES...WINDS AND TEMPERATURES. COLD FRONT IS SLOWLY WORKING ITS WAY THROUGH SOUTHEAST TEXAS THIS EVENING...APPROACHING THE I-10 CORRIDOR AT AROUND 9 PM. AREAS OF RAIN WITH EMBEDDED SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS THE AREA...AND MODELS INDICATE THIS SHOULD CONTINUE OVERNIGHT AND ON INTO TOMORROW MORNING (SOME SPOTS WITH THE HEAVIER STORMS HAVE ALREADY RECEIVED 1 TO 2 INCHES). TEMPERATURES ARE IN THE LOW TO MID 50S BEHIND THE FRONT UP NORTH...AND EXPECT THIS COOLER AIR TO WORK ITS WAY TOWARD THE COAST OVERNIGHT. 42 && PREV DISCUSSION... /ISSUED 609 PM CST TUE FEB 25 2014/ DISCUSSION... 00Z AVIATION DISCUSSION BELOW. AVIATION... THE SHORT TERM FORECAST...OR THROUGH THE EARLY WEDNESDAY MORNING HOURS...WILL BE FOR INTERMITTENT SHOWERS WITH A ISOLATED STORM AND STRENGTHENED NORTH WIND BEHIND AN EVENING COLD FRONTAL PASSAGE. THE MAIN IMPULSE DRIVING THIS ONGOING WIDELY SCATTERED -SHRA (ISO -TSRA) IS TRAVELING ACROSS NORTHERN TEXAS THIS EVENING WITH THE ONLY TRIGGERS LEFT OVER IN THIS HIGHLY-MOIST ENVIRONMENT FOR REPEAT PRECIPITATION BEING ANOTHER EASTERN PASSING SHORTWAVE RIPPLE WITHIN THE WESTERLY FLOW AND/OR THE ENHANCED POST-FRONTAL ISENTROPIC UPGLIDE AS SOUTHWESTERLY MID-UPPER FLOW RIDES UP AND OVER A PUMPED UP NORTH-NORTHEAST LOWER LEVEL WIND. BETTER UPPER DIFFULENCE BY TOMORROW AFTERNOON AS SE TX FALLS UNDER AN EXITING RRQ JET. CONSIDERING THE ABOVE ELEMENTS AND...EVEN WITH NWP MODELING NOT PROVIDING MUCH GUIDANCE UP TO NOW...STILL BELIEVE THAT ALL WILL COME IN-LINE FOR BETTER OVERALL (LIGHT) RAIN COVERAGE. PROBABLY NOT AN ALL-DAY RAIN EVENT...BUT GT 50% OF THE TIME THERE WILL BE THAT PASSING SHOWER...BRIEF MODERATE RAINFALL ASSOCIATED WITH STRONGER CELLS WEDNESDAY AFTERNOON...BUT THERE WILL ALSO BE LONGER PERIODS OF A JUST A LIGHT MIST AND/OR DRIZZLE ALONG WITH THOSE PESKY FLUCTUATING DECKS FROM IFR TO MVFR AND VICE VERSA. 31 PREV DISCUSSION... /ISSUED 333 PM CST TUE FEB 25 2014/ DISCUSSION... FRONT IS NOW PUSHING INTO NRN PORTIONS OF SE TX. SHOULD BE BETWEEN I-10 AND THE COAST AROUND MIDNIGHT AND OFF THE BEACHES BY 4AM (EFFECTIVELY ENDING SEA FOG ISSUES FOR A FEW DAYS). STARTING TO SEE SOME SCT PRECIP DEVELOP ACROSS S PARTS OF THE AREA AND EXPECT IT TO GRADUALLY INCREASE IN COVERAGE AHEAD OF, AND ESPECIALLY BEHIND, THE FRONT. HRRR MODEL AND TO A DEGREE NAM12 HAS DONE FAIRLY WELL WITH RAINFALL DEPICTION (OR LACK THEREOF) SO FAR TODAY AND SHORT TERM FCST WAS TRENDED THAT WAY. GFS/ECMWF HAVE BEEN HORRIBLY OVERDONE BOTH IN COVERAGE & AMOUNTS UP TO THIS TIME. PERIODS OF PRECIP WILL LIKELY CONTINUE THRU WED IN ASSOCIATION WITH H85 FRONT AND UPPER IMPULSES RIDING FURTHER OVERHEAD IN THE WRLY FLOW ALOFT. CONSIDERING STRONG CAA...CLOUDINESS AND PRECIP THE HIGHS FOR THE 24 HOUR PERIOD WILL OCCUR AROUND MIDNIGHT FOLLOWED BY FALLING AND/OR STEADY TEMPS IN THE 40S WED. RAIN SHOULD TAPER OFF WED EVENING. COOL WX CONTINUES THURS BUT ONSHORE WIND WILL BE RESUMING AS HIGH PRES MOVES EAST AND NEXT SHORTWAVE STARTS DIGGING SEWD DOWN THE 4-CORNERS AREA. THIS DISTURBANCE ISN`T AS IMPRESSIVE AS PREVIOUS DAYS AND DON`T ANTICIPATE MUCH OF AN IMPACT HERE AS IT MOVES ALONG THE RED RIVER FRIDAY...AS BEST ENERGY WILL BE WELL NORTH AND A CAP SHOULD BE IN PLACE. FURTHER LOWERED POPS. WARMING TREND CONTINUES THRU THE WEEKEND WITH ONSHORE FLOW IN PLACE. APPEARS THAT WE`LL PROBABLY HAVE ANOTHER COASTAL FOG EVENT BUT LOOKS LIKE MARDI GRAS PARADES SHOULD OTHERWISE BE DRY PRIOR TO MID TO LATE SUNDAY AFTN. NEXT STORM SYSTEM APPROACHES FROM THE WEST LATE IN THE WEEKEND AND KEPT 20-40% POPS IN PLACE SUN AFTN/NIGHT AHEAD OF THE NEXT FRONT THAT`LL BE MOVING THRU SUNDAY NIGHT OR MONDAY. KNOCKED TEMPS DOWN EARLY NEXT WEEK (MAYBE NOT ENOUGH) AS 1040+MB HIGH DROPS INTO THE PLAINS. 47 MARINE... SEA FOG WILL CONTINUE OVER THE GULF WATERS THIS AFTERNOON. AM EXPECTING THE FOG TO REDEVELOP AND BECOME DENSE OVER THE BAYS LATER THIS AFTERNOON AND EVENING. THE FOG WILL CLEAR OUT BETWEEN MIDNIGHT AND SUNRISE AS A COLD FRONT PUSHES THROUGH THE BAYS AND OFF THE COAST. THE MODELS HAVE BEEN FAIRLY CONSISTENT THE PAST FEW DAYS AND AM FAIRLY CONFIDENT ON THE TIMING. EXPECT THE FRONT TO MOVE THROUGH THE BAYS BY AROUND 3 AM AND THEN BEYOND 20 NM OFFSHORE BY 4 AM. THE 12Z MODEL RUN AND GUIDANCE FROM THIS MORNING FORECASTED SLIGHTLY HIGHER WINDS...INDICATING THAT SMALL CRAFT ADVISORIES ARE LIKELY FOR THE GULF WATERS AND MATAGORDA BAY. WOULD NOT BE SURPRISED IF WINDS INCREASE TO BETWEEN 20 AND 25 KNOTS FOR AT LEAST MOST OF THE LOWER PART OF GALVESTON BAY...ALSO. EXPECT THE NORTHEASTERLY WINDS TO DIMINISH WEDNESDAY NIGHT AND THURSDAY. ANOTHER FOG EVENT MAY DEVELOP BY LATE THIS WEEK AS ONSHORE REDEVELOPS. && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 43 43 33 57 42 / 70 60 20 10 10 HOUSTON (IAH) 49 49 36 59 43 / 70 70 30 10 10 GALVESTON (GLS) 54 54 42 55 53 / 70 60 40 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...DENSE FOG ADVISORY UNTIL 4 AM CST WEDNESDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY FROM 6 AM TO NOON CST WEDNESDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT SHOULD EXERCISE CAUTION WEDNESDAY AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM CST WEDNESDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT SHOULD EXERCISE CAUTION FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO MIDNIGHT CST WEDNESDAY NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM... WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. SMALL CRAFT SHOULD EXERCISE CAUTION LATE WEDNESDAY NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...31 AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
936 AM EST Wed Feb 26 2014 .Update...The 12z KTAE sounding was nearly saturated up to 600mb with deep west to southwest flow. The cold front as of 14z has already advanced into SW GA and the Florida panhandle. Most locations have already reached the max temp for today and temps will either remain steady or slowly fall through this afternoon. Rain continues to be widespread and PoPs were untouched. Thus far, SCT TSTMS have stayed offshore so mention of TSTMS were removed for all but the coastal areas and SE Big Bend. .Prev Discussion [411 AM EST]... .Near Term [Through Today]... At 09z, a surface cold front extended from a weak low in SC, southwest to near Albany GA, to near Destin FL, and then along much of the rest of the LA-TX Gulf coast. Regional radars showed a fairly large area of rain along and to the north of the surface cold front from near the AL-GA state line westward to SE TX. The placement of the rain relative to the surface front was suggestive of an anafront structure, with rearward sloping ascent along the cold front through the vertical. This is confirmed by WSW flow on area radar VWPs in the 900-700mb layer, and from a glance at RAP isentropic charts. Given the isentropic ascent in the lowest levels of the troposphere, but a general lack of significant forcing aloft, it`s likely that rain will continue to be forced in a shallow layer just above the surface through the remainder of the day. Models are in fairly good agreement on the timing of the best isentropic ascent and QPF. We leaned towards the consensus of recent local and NCEP WRF runs. With widespread rain expected, PoPs were raised to 100% for today pretty much everywhere across the forecast area. The rain should be most widespread (and heaviest) in the morning, with it tapering off and clearing from NW-SE in the afternoon and early evening. Looking at GOES blended precipitable water product, there is a large plume of PWATS >150% of normal extending from the western parts of our forecast area west into Texas. This deeper moisture will continue to advect into the area today, and could support some locally heavier rain. This will be especially true near the Gulf coast - closer to the surface cold front as the strongest forcing for ascent arrives this morning after sunrise. Maximum QPF from convection allowing models (CAM) is focused around Gulf and Franklin counties and is on the order of 2-3 inches. With the heaviest rain likely to fall in the lower portions of river basins, and average rainfall generally between 0.50 and 1.00 inches, we don`t anticipate any significant flooding issues. Instability should be limited enough to only support some general thunderstorms - updrafts should be too weak to pose much of a severe weather concern. && .Prev Discussion [411 AM EST]... .Short Term [Tonight Through Friday]... Rain will taper off from north to south this evening, but may not clear completely from our Southeast FL Big Bend zones until Thursday morning. As skies clear behind the rain, temps will tumble into the 30s except for coastal and southeastern sections of the Big Bend. A light freeze is forecast along and north of an Albany to Dothan to Crestview line. Maximum freeze durations in Coffee County AL will be about 5 hours. Max temps will be about 10 degrees below normal on Thursday and range from the mid 50s far northwest to Around 60 southeast. This will set the stage for a widespread light freeze Thursday night that will impact most inland areas. Coastal locations will hold at 40. Temps will moderate to within a few degrees of normal on Friday with max temps ranging from the lower 60s north to the mid to upper 60s southeast. .Long Term [Friday Night Through Wednesday]... On Friday NIGHT, a shortwave will be moving across the Mid Atlantic states. Further to the west, a disturbance will be moving onshore into central California. A vort max located over the Rockies will propagate eastward in zonal flow bringing slight PoP chances on Saturday, however this forcing appears to be weak and displaced more to the north of our CWA. From here on the GFS and Euro really diverge in their handling of the upcoming pattern. The GFS is more aggressive in phasing a shortwave over western Mexico with a shortwave rounding the base of a trough over Idaho. This combination pushes a surface front through our area late Monday night into Tuesday but quickly exits the area. The Euro meanwhile remains less amplified keeping the flow aloft more zonal and bringing a series of vort maxes through the area early next week. This will cause a stalling of a surface front over our CWA, and with each passing upper-level vort max another round of rain. Both agree that Tuesday morning should be pretty wet but given the uncertainty with which this front will exit we have tentatively gone with 40 PoPs for Tuesday afternoon. .Aviation... [Through 12Z Thursday] We expect IFR CIGS at all terminals today along with periods of mostly -RA. Some +RA with TS will be possible closer to the Gulf coast, particularly at ECP and TLH. Some of the +RA could reduce visibilities to around 1-3SM at times. Rain will gradually clear out in the afternoon from NW-SE, with CIGS gradually lifting through MVFR to VFR range by the evening and continuing overnight. .Marine... A cold front will slip south across the waters today shifting winds to offshore. Wind speeds behind the front will reach marginal small craft advisory criteria across the western legs by midday. Advisory conditions will be possible across the eastern zones tonight. Winds will then drop below cautionary levels by midday Thursday as high pressure builds toward the waters. Winds will remain below headline criteria through the weekend as they gradually veer to the east and then southeast. .Fire Weather... Widespread wetting rains are expected today, which will leave fuel moisture rather high on Thursday. Some of the finer (smaller) fuels (measured by 10-hr fuel moisture) could dry out as a much drier air mass arrives for Thursday, but should not be sufficiently dry in Florida or Georgia to create red flag conditions. In southeast Alabama, red flag criteria includes 4+ hr durations of RH < 25%. This looks achievable, but the wet fuels would likely preclude any sort of critical fire weather conditions. For now, we will maintain the Fire Weather Watch. It`s possible durations could be met again on Friday in southeast Alabama, and by then smaller fuels would have likely dried more substantially. .Hydrology... Periods of moderate rain today and tonight across the forecast area will result in slight to modest rises on area rivers. The Choctawhatchee River at Bruce is forecast to crest right at flood stage from Thursday into Saturday. The Apalachicola River at Blountstown is at its crest and is forecast to fall below flood stage Thursday evening. The Aucilla River at Lamont is forecast to reach flood stage Thursday night and crest Friday night. Storm total rainfall through Thursday morning is forecast to be less than an inch north of I-10 with a maximum of near two inches over coastal sections of Gulf and Franklin Counties. With the greatest totals falling in the lower stretches of the river basins, rises will be confined mainly to FL. && .Preliminary Point Temps/PoPs... Tallahassee 60 39 60 29 65 / 100 50 10 0 0 Panama City 63 39 58 36 62 / 100 50 10 0 0 Dothan 54 31 57 31 62 / 100 30 0 0 0 Albany 55 32 58 29 62 / 100 20 0 0 0 Valdosta 59 37 59 30 64 / 100 50 0 0 0 Cross City 65 44 61 30 67 / 100 60 20 0 0 Apalachicola 64 41 58 35 61 / 100 60 10 0 0 && .TAE Watches/Warnings/Advisories... FL...None. GA...None. AL...Fire Weather Watch from Thursday morning through Thursday afternoon for Coffee-Dale-Geneva-Henry-Houston. GM...Small Craft Advisory until 10 AM EST Thursday for Coastal waters from Apalachicola to Destin FL out 20 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. && $$ UPDATE...BARRY NEAR TERM...LAMERS SHORT TERM...WOOL LONG TERM...BARRY/WALSH AVIATION...LAMERS/BARRY MARINE...WOOL FIRE WEATHER...LAMERS HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
952 AM EST WED FEB 26 2014 .SYNOPSIS... A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING 10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 928 AM EST WEDNESDAY...SNOW SQUALL ACTIVITY CURRENTLY MOVING ACROSS THE NORTHERN CHAMPLAIN VALLEY. THINK THAT CURRENT FORECAST IS IN GOOD SHAPE SO DID NOT ALTER POPS OR WX AT ALL. THIS AREA OF SQUALLS WILL PUSH EASTWARD ACROSS VERMONT OVER THE NEXT FEW HOURS AND THEN POPS DECREASE LATE THIS AFTERNOON AND EVENING. PREVIOUS DISCUSSION FOLLOWS. SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE ONTARIO AND AS FRONTOGENETIC CIRCULATION HAS BEEN DISRUPTED BY THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF STEEP LOW- LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF NEXT SYSTEM. NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY 15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE. FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY 8-9F IN THE NRN ADIRONDACK REGION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY. TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS. MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED 5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT ACRS THE SLV/WESTERN DACKS...WITH A NARROW BAND OF ENHANCED SNOW SHOWER ACTIVITY WITH VIS <1SM. LATEST HRRR/RAP DATA SHOWS THIS BAND ENTERING THE CPV BTWN 12-15Z THIS MORNING...BUT WEAKENING WITH SOUTHWEST DOWNSLOPE FLW AND INTERACTION OFF THE DACKS. A BRIEF 20 TO 30 MINUTE WINDOW OF MVFR CONDITIONS WITH VIS AROUND 3SM IN SNOW SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE WEST AT PBG/BTV. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL OCCUR AFT 14Z AT MPV/RUTLAND. IN ADDITION...THE COMBINATION OF UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 14Z THIS MORNING AT SLK. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15 KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY BTWN 14Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET THIS EVENING. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN 06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH ADDITIONAL LIGHT SNOW SHOWERS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS/NEILES SHORT TERM...BANACOS LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
737 AM EST WED FEB 26 2014 .SYNOPSIS... A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING 10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 732 AM EST WEDNESDAY...SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE ONTARIO AND AS FRONTOGENETIC CIRCULATION HAS BEEN DISRUPTED BY THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF STEEP LOW-LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF NEXT SYSTEM. NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY 15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE. FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY 8-9F IN THE NRN ADIRONDACK REGION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY. TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS. MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED 5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD. && .AVIATION /13Z WEDNESDAY THROUGH SUNDAY/... THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT ACRS THE SLV/WESTERN DACKS...WITH A NARROW BAND OF ENHANCED SNOW SHOWER ACTIVITY WITH VIS <1SM. LATEST HRRR/RAP DATA SHOWS THIS BAND ENTERING THE CPV BTWN 12-15Z THIS MORNING...BUT WEAKENING WITH SOUTHWEST DOWNSLOPE FLW AND INTERACTION OFF THE DACKS. A BRIEF 20 TO 30 MINUTE WINDOW OF MVFR CONDITIONS WITH VIS AROUND 3SM IN SNOW SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE WEST AT PBG/BTV. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL OCCUR AFT 14Z AT MPV/RUTLAND. IN ADDITION...THE COMBINATION OF UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 14Z THIS MORNING AT SLK. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15 KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY BTWN 14Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET THIS EVENING. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN 06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH ADDITIONAL LIGHT SNOW SHOWERS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS SHORT TERM...BANACOS LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
632 AM EST WED FEB 26 2014 .SYNOPSIS... A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING 10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 342 AM EST WEDNESDAY...VARIABLE CLOUD COVER...WIND AND WEATHER CONDITIONS TODAY WITH REINFORCING ARCTIC FRONTAL PASSAGE FROM WEST-TO-EAST EXPECTED LATER THIS MORNING. EXCELLENT CONVERGENCE NOTED ALONG APPROACHING SECONDARY/ARCTIC FRONT ACROSS ERN LAKE ONTARIO AND WRN NY EARLY THIS AM. EARLY AM RUC MODEL ANALYSIS INDICATES THE FRONT IS ASSOCIATED WITH STRONG SFC-925MB FRONTOGENESIS WITH ACCOMPANYING ISALLOBARIC RISE/FALL COUPLET...RESULTING IN ROBUST LINEAR FORCING. LAKE INDUCED INSTABILITY UP TO 100 J/KG AND STRONG LOW-LEVEL FORCING FOR ASCENT IS RESULTING IN NARROW CONVECTIVE BAND ALONG THE FRONT PRODUCING SNOW SQUALL ACTIVITY WITH BRIEF PERIOD OF MODERATE TO HEAVY SNOW (20-30 MINUTES). BTV SNOW SQUALL PARAMETER MAINTAINS SNOW SQUALL POTENTIAL AS FRONT SHIFTS EWD CROSSING OUR REGION THIS MORNING...BEFORE EXITING EAST OF THE CT RIVER VLY BY 18Z. FAVORABLE FRONTOGENETIC FORCING AND LOW-LEVEL MOISTURE AND INSTABILITY WILL BRING A BAND OF SNOW SHOWERS AND SQUALLS ACROSS NRN NY THRU ABOUT 12-13Z. MAY SEE CONVECTIVE ACTIVITY WEAKEN SLIGHTLY THRU THE CHAMPLAIN VALLEY WITH ABSENCE OF INSTABILITY LOCALLY AND FLOW DISRUPTION ACROSS THE ADIRONDACK REGION. INSTABILITY IS ACTUALLY BEST ACROSS NH/ME WITH INSOLATIONAL HEATING IN ADVANCE OF THE BNDRY...SO AGAIN...ANTICIPATE ORGANIZATION MAY WANE A BIT THRU THE CHAMPLAIN VLY...BUT INCREASE AGAIN ACROSS ERN VT MIDDAY HRS BEFORE EXITING RAPIDLY EWD WITH FROPA BY 17-18Z. SBCAPE VALUES REACH 100-150 J/KG IN NAM MODEL SOUNDINGS ALONG THE CT RIVER BETWEEN 15-18Z TODAY JUST AHEAD OF THE FRONTAL BNDRY. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS WITH THESE SNOW SHOWERS AND SQUALLS...LIKELY HIGHEST IN NRN NY AND THEN CENTRAL AND ERN VT. MAY RESULT IN SLOW TRAVEL FOR AN HOUR OR SO DURING SQUALL PASSAGE. WE/LL CONTINUE TO HIGHLIGHT THIS POTL IN THE HAZARDOUS WEATHER OUTLOOK AND THROUGH SOCIAL MEDIA. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID TO UPPER 20S...EXCEPT LOW 20S IN FAR SERN SECTIONS. STEEP LOW- LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF NEXT SYSTEM. NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY 15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE. FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY 8-9F IN THE NRN ADIRONDACK REGION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY. TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS. MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED 5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT ACRS THE SLV/WESTERN DACKS...WITH A NARROW BAND OF ENHANCED SNOW SHOWER ACTIVITY WITH VIS <1SM. LATEST HRRR/RAP DATA SHOWS THIS BAND ENTERING THE CPV BTWN 12-15Z THIS MORNING...BUT WEAKENING WITH SOUTHWEST DOWNSLOPE FLW AND INTERACTION OFF THE DACKS. A BRIEF 20 TO 30 MINUTE WINDOW OF MVFR CONDITIONS WITH VIS AROUND 3SM IN SNOW SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE WEST AT PBG/BTV. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL OCCUR AFT 14Z AT MPV/RUTLAND. IN ADDITION...THE COMBINATION OF UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 14Z THIS MORNING AT SLK. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15 KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY BTWN 14Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET THIS EVENING. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN 06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH ADDITIONAL LIGHT SNOW SHOWERS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS SHORT TERM...BANACOS LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
637 AM CST WED FEB 26 2014 .UPDATE... ISSUED AT 637 AM CST WED FEB 26 2014 THE ONGOING WIND CHILL ADVISORY STILL LOOKS GOOD FOR THIS UPDATE. IN ADDITION...INCREASING ISALLOBARIC WINDS STILL LOOK TO GENERATE WINDS MEETING WIND ADVISORY CRITERIA EAST THIS AFTERNOON. AS A RESULT...WILL LEAVE THE CURRENT HEADLINES AS IS FOR THIS UPDATE. OTHERWISE...THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST WED FEB 26 2014 THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID MORNING INTO THE AFTERNOON. EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES. FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35 BELOW. WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES. WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO 1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY. IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER. WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS WILL HAVE TO CONSIDER THAT POSSIBILITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 26 2014 WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND. SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM RANGE MODELS MAINTAIN A DRY FROPA. WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT. THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY. THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 637 AM CST WED FEB 26 2014 MAINLY CLEAR SKIES ARE EXPECTED AT THE TERMINAL LOCATIONS. THE MAIN CONCERN WILL BE INCREASING WINDS AS A COLD FRONT MOVES ACROSS THE REGION. WINDS WILL BECOME GUSTY FROM THE NORTHWEST...WITH THE STRONGEST WINDS EXPECTED FROM KMOT TO KJMS. CONTINUED TO CARRY THE 6SM IN BLSN AT KMOT AND KJMS ONCE THE WINDS INCREASE. WINDS WILL DIMINISH THIS WEDNESDAY EVENING. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ001>005- 009>013-021>023-025-035>037-046>048-050-051. WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING FOR NDZ004-005-012-013-022-023-025-037-048-051. && $$ UPDATE...TM SHORT TERM...CK LONG TERM...TM AVIATION...CK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
218 AM PST WED FEB 26 2014 .SYNOPSIS...HIGH PRESSURE ALOFT WILL SHIFT EAST TODAY AS AN ELONGATED FRONTAL SYSTEM MOVES CLOSER TO THE COAST. OFFSHORE LOW-LEVEL FLOW CONTINUES TODAY...BUT WEAKENS IN THE AFTERNOON. A SERIES OF WEAK IMPULSES WITHIN THE SOUTH FLOW ALOFT WILL TRAVERSE THE AREA TODAY FOR A THREAT OF LIGHT RAIN...MAINLY OVER THE COAST AND COAST RANGE. THE UPPER LOW ENTERS SW OREGON OVERNIGHT INCREASING THE RAIN THREAT OVER THE AREA. A LOW PRESSURE AREA REMAINS PARKED OFF THE NRN CALIFORNIA OR FAR SOUTH OREGON COAST THURSDAY. WEAK HIGH PRESSURE RETURNS FRIDAY. IT LOOKS LIKE MUCH COOLER AIR WILL WORK ITS WAY INTO THE WASHINGTON ZONES AND INTO THE COLUMBIA GORGE OVER THE WEEKEND. MILDER WEST FLOW ALOFT RETURNS EARLY NEXT WEEK. && .SHORT TERM...WEDNESDAY THROUGH FRIDAY...THE FORECAST AREA REMAINS UNDER A LARGE-SCALE BLOCKING PATTERN EARLY THIS MORNING. WATER VAPOR IMAGERY WITH 500 MB HEIGHT LINES SHOWS AN UPPER RIDGE AXIS FROM NEAR VANCOUVER ISLAND THROUGH THE WASHINGTON CASCADES AND TO FAR SERN OREGON. MEANWHILE...A SPLITTING UPPER TROUGH RESIDES OUT NEAR 140W WITH THE MAIN ENERGY ALONG 40N. FINALLY...THE LARGE HUDSON BAY LOW IS KEEPING EVERYTHING IN PLACE. THE GFS AND 03Z HRRR BOTH INDICATE A BAND OF PRECIP MOVING INTO THE SWRN PART OF THE AREA BETWEEN 15Z AND 18Z THIS MORNING. THE HRRR SHOWS THIS LIGHT PRECIP ACTIVITY REACHING THE CENTRAL OREGON COAST AND COAST RANGE AROUND 15Z...THEN DRIFTING E TO NE THROUGH THE MORNING. TIME-HEIGHT...CROSS-SECTION AND MODEL SOUNDING ANALYSIS ALL INDICATE MID-LEVEL MOISTURE...700-800 MB...REACHING THE CENTRAL COAST BY SUNRISE. THE COLUMN CONTINUES TO SATURATE FROM THE TOP DOWN THROUGH THE MORNING. THIS PRECIP ACTIVITY SHOULD NOT AMOUNT TO MUCH...BUT WILL BE AIDED BY UPPER LEVEL DIVERGENCE. THIS PRECIP WILL ENCOUNTER THE MODERATE OFFSHORE LOW-LEVEL FLOW AS IT DRIFTS N TOWARD THE COLUMBIA RIVER. BEST CHANCES FOR PRECIP THIS AFTERNOON WILL BE OVER THE FAR SOUTH AND ALSO ALONG THE CASCADES. THE KTTD-KDLS GRADIENT WAS -9.3 MB AT 09Z. CORBETT GUSTING TO NEAR 55 MPH...WITH SEVERAL LOCATIONS IN THE EAST PORTLAND AND VANCOUVER METRO AREA GUSING TO AT LEAST 35 MPH. PEAK OFFSHORE GRADIENT VIA THE LATEST NAM LOOKS TO BE THIS MORNING. NAM DROPS THE KTTD-KDLS GRADIENT TO 4-5 MB BY 21Z. MAY NOT DROP QUITE THAT FAST...BUT THE AM CONFIDENT WIND WILL EASE THIS AFTERNOON. PATTERN CHANGES TONIGHT AND THU AS THE UPPER RIDGE AXIS FINALLY SHIFTS TO THE EAST. GFS AND ECMWF SHOW A 500 MB LOW PRES AREA FORMING NEAR 40N 127W BY 06Z THU. SOUTH DIFFLUENT FLOW ALOFT BECOMES MORE PRONOUNCED THIS EVENING AS THE LOW MOVES CLOSER TO THE N CA AND FAR SRN OREGON COAST. EXPECT PRECIP TO SPREAD NWD THIS EVENING AND TONIGHT. MODELS CLEARLY SHOW A DEFORMATION BAND SETTING UP ACROSS THE CENTRAL PORTION OF THE AREA AROUND MIDNIGHT THEN DRIFTING NWD OVERNIGHT AND FINALLY MOVING INTO SW WA THU MORNING. MODELS TREAT THE UPPER LOW A BIT DIFFERENT...BUT BOTH THE GFS AND ECMWF SHOW THE LOW FILLING AND BECOMING AN OPEN TROUGH 18Z THU AS IT DRIFT N TO NE THROUGH SWRN OREGON. EXPECT PRECIP TO SLOWLY WANE FROM S TO N THU AFTERNOON AND EVENING. LARGE-SCALE PATTERN REVERTS TO SOMETHING CLOSE TO WHAT IT IS NOW THU NIGHT. INTERESTING SYNOPTIC SITUATION SETS UP LATE THU NIGHT AND FRI. MODELS SHOW A CLOSED LOW OUT NEAR 35N 130W...A PINCHED-OFF RIDGE IN THE GULF OF ALASKA AND A LARGE BUT COLD CANADIAN TROUGH TRYING TO RETROGRADE TO THE WEST. GFS AND ECMWF SUGGEST SOME OF THIS COLDER AIR MAY START TO FILTER IN CENTRAL WASHINGTON FRI AND THEN SLIDE SOUTH ALONG THE CASCADES AND INTO THE CENTRAL COLUMBIA GORGE BY 00Z SAT. WEISHAAR .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...MUCH OF THE EXCITEMENT FOR THE EXTENDED OCCURS THIS UPCOMING WEEKEND AND MONDAY. THE COLD AIR MENTIONED ABOVE IN THE SHORT-TERM SECTION BECOMES MORE ESTABLISHED OVER THE WEEKEND. LOOKS TO BE A SIMILAR SCENARIO TO THIS PAST SUNDAY AND MONDAY WITH A SNOW-THREAT FOR THE UPPER HOOD RIVER VALLEY. THIS COLDER AIR WILL CONTINUE TO SPILL INTO THE COLUMBIA GORGE THIS WEEKEND. MODELS HAVE MAJOR DIFFERENCES HANDLING THE COLD AIR SUNDAY. GFS FORCES THE MILDER WESTERLIES INTO THE PAC NW SUN WHILE THE ECMWF CONTINUES TO RETROGRADE THE COLD UPPER LOW INTO SRN B.C....WITH A DISTINCT COLD AIR BOUNDARY ACROSS WRN WA. ECMWF ALSO SHOWS SOME OVER-RUNNING PRECIP MOVING INTO WRN WA AND OREGON SUN. THIS WOULD BE A PRIME POTENTIAL SNOW SITUATION FOR SWRN WA AND IN THE COLUMBIA GORGE SHOULD THE ECMWF VERIFY. THE GEM IS MORE LIKE THE GFS...SHUNTING THE COLD AIR FURTHER TO THE EAST SUN. MONDAY COULD ALSO BE A GOOD SNOW SITUATION FOR SWRN WA AND AREAS NEAR THE COLUMBIA GORGE IF THE ECMWF IS RIGHT. HOWEVER...THE GFS IS NEARLY 24-HRS SLOWER COMPARED TO THE ECMWF. ALL IN ALL...FORECASTER CONFIDENCE IS RATHER LOW SUNDAY AND BEYOND. WEISHAAR && .AVIATION...EAST WINDS ARE THE MAIN AVIATION IMPACT TODAY. THESE WINDS ARE STRONGEST IN THE NORTHERN PORTION OF THE FORECAST AREA...WITH THE GREATEST IMPACTS FOR KTTD AND KPDX. EAST WINDS GUSTY AT TIMES WILL PERSIST THROUGH THE MORNING...EASING IN THE AFTERNOON. OTHERWISE VFR CONDITIONS WITH MAINLY THIN AND HIGH CLOUDS. THE EAST WINDS HAVE DRIED THE LOWER LEVELS SOME...AND DO NOT EXPECT ANY FOG THIS MORNING. A FRONT WILL BRING A CHANCE OF RAIN FROM THE SOUTH EARLY THIS AFTERNOON THEN TO THE NORTH MAINLY OVER THE CASCADES AND COAST RANGE LATER THIS AFTERNOON. CIGS WILL LOWER AS THE FRONT NEARS BUT EXPECT CONDITIONS TO GENERALLY REMAIN VFR. THERE WILL BE MORE WIDESPREAD RAIN WITH MVFR CONDITIONS LATE TONIGHT INTO THU MORNING. KPDX AND APPROACHES...VFR WITH EAST WINDS 10 TO 20 KT THROUGH THIS MORNING. WINDS WILL EASE THIS AFTERNOON. CLOUDS WILL INCREASE IN THE AFTERNOON AS A FRONT BUT EXPECT CONDITIONS TO REMAIN VFR. THERE IS A SLIGHT CHANCE OF A FEW SPRINKLES AFT 22Z.THERE WILL BE A GREATER CHANCE FOR RAIN AND MVFR CONDITIONS LATE TONIGHT INTO THU MORNING. HARTLEY && .MARINE...OFFSHORE WINDS CONTINUE MARGINAL SMALL CRAFT CONDITIONS NORTH OF CANNON BEACH THIS MORNING. THE SURFACE PRESSURE GRADIENT WILL RELAX LATER THIS MORNING AS THE HIGH PRESSURE INLAND WEAKENS AND SHIFTS TO THE NE...AND THE WINDS WILL EASE. RELATIVELY LIGHT E-SE WINDS WILL CONTINUE THROUGH THURSDAY NIGHT. A COMPLEX LOW OFFSHORE HAS GENERATED A W-SW SWELL THAT WILL BUILD IN THE WATERS TODAY. ALTHOUGH THE BUOYS THE PAST 12 HOURS HAVE SHOWN THE SEAS TO BE A COUPLE OF FEET LOWER THAN GUIDANCE...THERE IS SOME EVIDENCE THAT THE FORECAST SWELL IS ON THE WAY. A BUOY FAR TO THE SE OF THE WATERS..46002 HAS BEEN REPORTING 14 TO 16 FT AT 15 SECONDS AS THE ENP FORECASTED. THE DIRECTION OF THIS BUOY FROM 46029 IS AROUND 230 DEGREES. SINCE THE EXPECTED SWELL IS 240 DEGREES THIS BUOY IS A GOOD INDICATOR OF WHAT IS TO COME OF THIS SWELL. A SIMPLE DECAY TOOL SUGGEST THIS SWELL WILL BE 11 TO 13 FT AT 16 SECONDS AS IT MOVES THROUGH THE NORTHERN OREGON WATERS LATER THIS MORNING AND AFTERNOON. CONFIDENCE IS HIGHER THAT AT LEAST THE SOUTHERN WATERS...SOUTH OF CASCADE HEAD...WILL HAVE SMALL CRAFT SEAS...AND HAVE ISSUED AN ADVISORY. BUOY 46050 THE PAST COUPLE OF HOURS HAS BEEN SHOWING INCREASING HEIGHTS WHICH IS ANOTHER INDICATOR THAT THE WELL IS ON THE WAY. HARTLEY && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 AM PST EARLY THIS MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM NOON TODAY TO 4 PM PST THIS AFTERNOON. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 AM TO 6 AM PST THURSDAY. && $$ MORE WEATHER INFORMATION ONLINE AT.. HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1003 AM EST WED FEB 26 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION THIS MORNING AND USHER IN COOLER CANADIAN HIGH PRESSURE. THIS HIGH WILL BECOME REINFORCED FROM THE NORTH ON FRIDAY AND LINGER INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM EST WEDNESDAY...LATEST RADAR IMAGERY CONTINUES TO INDICATE SHOWER ACTIVITY SOUTH OF INTERSTATE 85 ASSOCIATED WITH EARLIER WEAK FRONTAL BOUNDARY PASSAGE. MOST RECENT HIGHRES NEAR TERM GUIDANCE SOLUTIONS YIELD DECREASING COVERAGE OVER THE NEXT 2-3 HOURS FOR THESE ZONES. ADDITIONALLY...CONFIDENCE CONTINUES TO DECREASE ON ANY SNOW SHOWER ACTIVITY ALONG THE HIGH TERRAIN OF NC ASSOCIATED WITH WEAK NORTHWEST FLOW THEREFORE DECIDED TO LOWER POPS FURTHER WITH ALL MENTIONABLE POPS REMOVED BY 16Z ALONG THE TN BORDER. OTHERWISE...FORECAST REMAINS ON TRACK AND ASIDE FROM TWEAKS TO TEMPERATURES AND DEWPOINTS...NO OTHER SIGNIFICANT CHANGES MADE. LOW RH AND INCREASING WINDS CONTINUE TO PRESENT MODEST FIRE WX CONCERNS TOMORROW...ESPECIALLY IN THE HIGH TERRAIN OF NC. PLEASE REFER TO FIRE WX SECTION OF AFD FOR DETAILS. PREVIOUS DISCUSSION... AS OF 615 AM EST...SHORTWAVE ROTATES THRU THE ERN CONUS UPPER TROUGH THIS MORNING...WITH COLD FRONT USHERING IN HIGH PRESSURE AND A MUCH COLDER AIRMASS OVER THE COURSE OF THE DAY. WESTERLY MIDLEVEL WINDS PRIOR TO THE FRONT WILL PROVIDE SLIGHT WARM ADVECTION AND ASSOCIATED LIFT...BUT MODELS SEEM TO RESPOND MORE TO INTERACTION OF FRONTAL CONVERGENCE WITH INCUMBENT MOISTURE ACRS GA/SC. MESO MODELS INCLUDING LATEST COUPLE HRRR RUNS CONFINE QPF RESPONSE WELL SOUTH OF I-85. GFS AND SREF HOWEVER FAVOR MORE OF THE PRECIP DEVELOPING ACRS THE UPSTATE. THIS IS NOT WELL SUPPORTED BY RADAR TRENDS SO FAR THIS AM. BEST POPS STILL LOOK TO BE IN 12-15Z TIMEFRAME AS THE FRONT ENTERS THE LOWER PIEDMONT. DESPITE LACK OF MODEL RESPONSE...GIVEN THE SETUP IT IS REASONABLE TO INCLUDE SCHC POPS A BIT FURTHER NORTH...WITH TIGHT THERMAL GRADIENT ACRS THE FA IN EXIT REGION OF THE SHORTWAVE THRU THE MRNG. NW FLOW STILL LOOKS TO HAVE SUFFICIENT ORIENTATION AND MOISTURE TO PRODUCE BRIEF LIGHT SNOW IN THE MTNS...BUT LATEST GUIDANCE SUPPORTS ONLY CHC POPS AND MINIMAL ACCUMS. IN FACT THIS MAY BE A BIT OPTIMISTIC GIVEN LACK OF RADAR RETURNS OVER EAST TN. CLEARING OF THE LOW-MID CLOUDS ASSOCIATED WITH THE FRONTAL ZONE IS EXPECTED TO RAPIDLY OCCUR THRU MIDDAY LEAVING A MOSTLY SUNNY AFTN. GIVEN THE COLD AND NEWLY ARRIVED AIR MASS BUT ALSO ABUNDANT SUNSHINE AND SLIGHT DOWNSLOPING...A BLEND OF MOS AND RAW TEMPS IS APPROPRIATE WHICH CONTINUES TO SUPPORT TEMPS A COUPLE CATEGORIES BELOW NORMAL EXCEPT IN THE HIGH TERRAIN WHERE MANY AREAS WON/T RISE OUT OF THE 30S. TONIGHT...WINDS BECOME LIGHT AND SKIES REMAIN CLEAR AND LOWS DROP INTO THE TEENS MTNS AND 20S PIEDMONT. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... AS OF 200 AM WEDNESDAY...A DRY COLD FRONT WILL CROSS THE REGION DURING THE DAY ON THURSDAY...LOWERING DEWPOINTS EVEN FURTHER. WITH BREEZY TO WINDY CONDITIONS OVER THE NC MTNS AND FOOTHILLS...THE POTENTIAL EXITS FOR CRITICAL FIRE WEATHER CONDITIONS. PLEASE SEE THE FIRE WEATHER PART OF THE DISCUSSION FOR MORE DETAILS. OTHERWISE...DRY COLD AIR DAMMING WILL BECOME MORE PRONOUNCED OVER THE REGION THURSDAY NIGHT AND FRIDAY. THE THICKNESS TROUGH IN THE LEE SHOULD RESULT IN COLD CONDITIONS THU NIGHT AND WELL BELOW NORMAL TEMPERATURES ON FRIDAY. THURSDAY WE SHOULD SEE CLEAR...BLUE SKIES. SKIES REMAIN CLEAR THU NIGHT...BUT HIGH CLOUDS SHOULD BE ON THE INCREASE DURING THE DAY ON FRIDAY. A FAST MOVING SHORT WAVE WILL CROSS THE NC ZONES FRI NIGHT. MOST OF THE FORCING WITH THE WAVE PASSES NORTH OF THE FORECAST AREA. HOWEVER...LLVL WARM ADVECTION OVER THE WRN PIEDMONT MAY SUPPORT SOME PATCHY LIGHT PCPN OVER THE ERN ZONES. THERE ALSO APPEARS TO BE SUFFICIENT FORCING ACROSS THE MTNS TO SUPPORT CHANCE POPS AS WELL. I USED THE BOURGOUIN TECHNIQUE WHICH STARTS PCPN AS RAIN EARLY FRIDAY NIGHT WITH A TRANSITION TO SNOW AND THEN FREEZING RAIN OVER MOST OF THE NC ZONES. UNDERSTAND THAT QPF IS VERY LIGHT WITH THIS EVENT AND POPS ARE GENERALLY IN THE LOW CHANCE TO SLIGHT CHANCE RANGE. THAT/S TO SAY...THE WEATHER GRID LOOKS SCARIER THAN THE REALITY OF THE SITUATION. STILL...WE COULD SEE A LIGHT ACCUMULATION OF SNOW OR ICE NORTH OF I40 AND OVER PARTS OF THE NC MTNS FRIDAY NIGHT...BUT THE PCPN IS SO LIGHT I DON/T EVEN PLAN TO MENTION IT IN THE HWO ATTM. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... AS OF 230 AM EST WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SUNDAY WITH WHATS LEFT OF AN UPPER SHORTWAVE MOVING OUT OVER THE ATLANTIC AND UPPER RIDGING BUILDING OVER THE GULF OF MEXICO AND SE CONUS. THE LONG RANGE MODELS ARE TRYING TO CLOSE OFF AN H5 LOW OVER EXTREME SOUTHERN BRITISH COLUMBIA EARLY SUNDAY WITH THE NEWER RUN OF THE GFS BEING MORE PRONOUNCED. AS WE MOVE INTO MONDAY...HEIGHTS BEGIN TO LOWER AGAIN AS A COMPLEX UPPER TROF PATTERN MOVES SE ACROSS THE FAR NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THE MODELS INDICATE THAT THE MAIN TROF AXIS WILL LIKELY BE NORTH OF THE CAROLINAS BY LATE TUES/EARLY WED AND PERSIST OVER THE REGION THRU DAY 7. OVERALL...THE LONG RANGE MODELS APPEAR TO BE COMING INTO BETTER AGREEMENT WRT THE PROGRESSION AND TIMING OF THIS UPPER TROF SYSTEM...WITH THE GFS BEING MORE AMPLIFIED AND BRINGING THE SYSTEM FARTHER SOUTH COMPARED TO THE ECMWF. AT THE SFC...THE HIGH CENTERED OVER NEW ENGLAND HELPING TO PRODUCE A COLD AIR WEDGE PATTERN OVER THE CAROLINAS WILL BE MOVING WELL OFF THE COAST BY EARLY SUN. THE MODELS CONTINUE TO MAINTAIN ANOTHER BERMUDA TYPE HIGH CENTERED TO OUR EAST ON SUN AND EARLY MON. THEY ALSO SPIN UP A LOW OVER THE SOUTHERN MISS RIVER VALLEY EARLY MON AND MOVE IT OVER THE CWFA BY MON AFTERNOON. WHAT HAPPENS OVER THE NEXT 24 TO 36HRS VARIES CONSIDERABLY BETWEEN THE GFS AND ECMWF. THE GFS KEEPS THE LOW AND ITS ASSOCIATED REGION OF BROAD AND DEEP MOISTURE OVER THE FCST AREA THRU TUES AFTERNOON BEFORE MOVING IT NE AND OFFSHORE...WHILE THE ECMWF AND CMC MOVE IT OFFSHORE BY MON EVENING WITH DRIER HIGH PRESSURE SPREADING OVER THE REGION IN ITS WAKE ON TUES. BOTH MODELS AGREE THAT THE REMAINDER OF THE FCST SHOULD BE DRY HIGH PRESSURE OVER THE AREA ON WED. TEMPS WILL START OUT WELL ABOVE NORMAL FOR EARLY MARCH WITH HIGHS ON SUN IN THE MID 60S FOR THE LOWER ELEVATIONS AND UPPER 50S TO LOW 60S FOR THE HIGHER TERRAIN. BY THE END OF THE PERIOD...I ANTICIPATE THAT VALUES WILL COOL BACK DOWN BELOW CLIMATOLOGY. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...LOW VFR CLOUDINESS LINGERS THIS MRNG IN WARM UPGLIDE PRIOR TO ARRIVAL OF COLD FRONT. PRECIP CHANCES DUE TO THE UPGLIDE ARE LOW...WITH SHORT TERM GUID KEEPING MOST OF THE RESPONSE WELL SOUTH. A FEW SPRINKLES OR BRIEF -SHRA ARE POSSIBLE THRU MID MRNG...BUT WITHOUT RESTRICTIONS. MAINLY NE WINDS PRIOR TO THE FROPA...POSSIBLY KEPT CLOSER TO 090 DUE TO LEE TROUGHING. NW WINDS AND CLEARING SKIES BY MIDDAY POST FROPA. SKC LIKELY OVERNIGHT...BUT NAM/GFS BOTH TRY TO DEVELOP SOME SPOTTY LOW VFR CLOUDS DUE TO LLVL CONVERGENCE IN THE LEE OF THE MTNS. THIS IS A BIT UNUSUAL AND IS NOT BACKED UP BY MOS SO WILL NOT REFLECT IN TAF. ELSEWHERE...PRECIP CHANCES THIS AM ARE TOO LOW TO MENTION EXCEPT AT KAND...WHICH WILL BE NEARER THE BEST LIFT/MSTR ASSOCIATED WITH WARM ADVECTION OVER THE DEEP SOUTH. CIGS LIKELY TO STAY LOW VFR AT WORST...BUT WILL MONITOR UPSTREAM OBS FOR LOWER CIGS WHICH MIGHT BE ASSOCIATED WITH PRECIP. NW FLOW INTO THE MTNS WILL PRODUCE A FEW -SHSN BUT THESE SHOULD BE VERY LIGHT AND MAY NOT CAUSE SGFNT REDUCTION IN VSBY. EXCEPT AT KAVL WHICH REMAINS NW...NELY WINDS WILL PREVAIL UNTIL THE FRONT PASSES AND SKIES GRADUALLY CLEAR. POST FROPA WINDS WILL MAINLY BE NW BEFORE VEERING TONIGHT. OUTLOOK...DRY/VFR THU-FRI...BUT PRECIPITATION AND ASSOCIATED RESTRICTIONS ARE POSSIBLE EARLY SAT. CONFIDENCE TABLE... 15-21Z 21-03Z 03-09Z 09-15Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... LAND MANAGEMENT PARTNERS SHOULD EXPECT COORDINATION THIS AFTERNOON FOR POSSIBLE FIRE WEATHER WATCH OR FIRE DANGER STATEMENTS FOR THURSDAY. THERE IS LITTLE CHANGE IN THINKING FROM THE PREVIOUS FORECAST CYCLE. THE PLANNING FORECAST HAS BEEN UPDATED THROUGH TOMORROW BASED UPON THE LATEST FORECAST DATA...PRIMARILY FOR MINOR CHANGES IN SMOKE MANAGEMENT PARAMETERS. RH HAS ALSO BEEN LOWERED SLIGHTLY FOR THIS AFTERNOON...BUT MIN RH OF 25 PERCENT OR LESS IS EXPECTED TO BE LOCALIZED AND BRIEF...WHILE WINDS SHOULD GRADUALLY DIMINISH THROUGH THE AFTERNOON. AS THE AIR MASS BEGINS TO WARM ON THURSDAY...RH IS EXPECTED TO FALL BELOW 20 PERCENT IN MOST AREAS DURING THE AFTERNOON. IN ADDITION... W/NW WINDS WILL BEGIN TO INCREASE AHEAD OF ANOTHER DRY COLD FRONT DURING THE AFTERNOON. WINDS MAY GUST AS HIGH AS 30 MPH IN THE MTNS...AND TO AROUND 20 MPH IN THE PIEDMONT. CRITICAL WIND AND RH MAY OVERLAP FOR SEVERAL HOURS ACROSS THE MTNS AND NC FOOTHILLS THU AFTERNOON. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JPT NEAR TERM...WIMBERLEY SHORT TERM...MCAVOY LONG TERM...JPT AVIATION...WIMBERLEY FIRE WEATHER...LANE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
627 AM EST WED FEB 26 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION THIS MORNING AND USHER IN COOLER CANADIAN HIGH PRESSURE. THIS HIGH WILL BECOME REINFORCED FROM THE NORTH ON FRIDAY AND LINGER INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 615 AM EST...SHORTWAVE ROTATES THRU THE ERN CONUS UPPER TROUGH THIS MORNING...WITH COLD FRONT USHERING IN HIGH PRESSURE AND A MUCH COLDER AIRMASS OVER THE COURSE OF THE DAY. WESTERLY MIDLEVEL WINDS PRIOR TO THE FRONT WILL PROVIDE SLIGHT WARM ADVECTION AND ASSOCIATED LIFT...BUT MODELS SEEM TO RESPOND MORE TO INTERACTION OF FRONTAL CONVERGENCE WITH INCUMBENT MOISTURE ACRS GA/SC. MESO MODELS INCLUDING LATEST COUPLE HRRR RUNS CONFINE QPF RESPONSE WELL SOUTH OF I-85. GFS AND SREF HOWEVER FAVOR MORE OF THE PRECIP DEVELOPING ACRS THE UPSTATE. THIS IS NOT WELL SUPPORTED BY RADAR TRENDS SO FAR THIS AM. BEST POPS STILL LOOK TO BE IN 12-15Z TIMEFRAME AS THE FRONT ENTERS THE LOWER PIEDMONT. DESPITE LACK OF MODEL RESPONSE...GIVEN THE SETUP IT IS REASONABLE TO INCLUDE SCHC POPS A BIT FURTHER NORTH...WITH TIGHT THERMAL GRADIENT ACRS THE FA IN EXIT REGION OF THE SHORTWAVE THRU THE MRNG. NW FLOW STILL LOOKS TO HAVE SUFFICIENT ORIENTATION AND MOISTURE TO PRODUCE BRIEF LIGHT SNOW IN THE MTNS...BUT LATEST GUIDANCE SUPPORTS ONLY CHC POPS AND MINIMAL ACCUMS. IN FACT THIS MAY BE A BIT OPTIMISTIC GIVEN LACK OF RADAR RETURNS OVER EAST TN. CLEARING OF THE LOW-MID CLOUDS ASSOCIATED WITH THE FRONTAL ZONE IS EXPECTED TO RAPIDLY OCCUR THRU MIDDAY LEAVING A MOSTLY SUNNY AFTN. GIVEN THE COLD AND NEWLY ARRIVED AIR MASS BUT ALSO ABUNDANT SUNSHINE AND SLIGHT DOWNSLOPING...A BLEND OF MOS AND RAW TEMPS IS APPROPRIATE WHICH CONTINUES TO SUPPORT TEMPS A COUPLE CATEGORIES BELOW NORMAL EXCEPT IN THE HIGH TERRAIN WHERE MANY AREAS WON/T RISE OUT OF THE 30S. TONIGHT...WINDS BECOME LIGHT AND SKIES REMAIN CLEAR AND LOWS DROP INTO THE TEENS MTNS AND 20S PIEDMONT. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... AS OF 200 AM WEDNESDAY...A DRY COLD FRONT WILL CROSS THE REGION DURING THE DAY ON THURSDAY...LOWERING DEWPOINTS EVEN FURTHER. WITH BREEZY TO WINDY CONDITIONS OVER THE NC MTNS AND FOOTHILLS...THE POTENTIAL EXITS FOR CRITICAL FIRE WEATHER CONDITIONS. PLEASE SEE THE FIRE WEATHER PART OF THE DISCUSSION FOR MORE DETAILS. OTHERWISE...DRY COLD AIR DAMMING WILL BECOME MORE PRONOUNCED OVER THE REGION THURSDAY NIGHT AND FRIDAY. THE THICKNESS TROUGH IN THE LEE SHOULD RESULT IN COLD CONDITIONS THU NIGHT AND WELL BELOW NORMAL TEMPERATURES ON FRIDAY. THURSDAY WE SHOULD SEE CLEAR...BLUE SKIES. SKIES REMAIN CLEAR THU NIGHT...BUT HIGH CLOUDS SHOULD BE ON THE INCREASE DURING THE DAY ON FRIDAY. A FAST MOVING SHORT WAVE WILL CROSS THE NC ZONES FRI NIGHT. MOST OF THE FORCING WITH THE WAVE PASSES NORTH OF THE FORECAST AREA. HOWEVER...LLVL WARM ADVECTION OVER THE WRN PIEDMONT MAY SUPPORT SOME PATCHY LIGHT PCPN OVER THE ERN ZONES. THERE ALSO APPEARS TO BE SUFFICIENT FORCING ACROSS THE MTNS TO SUPPORT CHANCE POPS AS WELL. I USED THE BOURGOUIN TECHNIQUE WHICH STARTS PCPN AS RAIN EARLY FRIDAY NIGHT WITH A TRANSITION TO SNOW AND THEN FREEZING RAIN OVER MOST OF THE NC ZONES. UNDERSTAND THAT QPF IS VERY LIGHT WITH THIS EVENT AND POPS ARE GENERALLY IN THE LOW CHANCE TO SLIGHT CHANCE RANGE. THAT/S TO SAY...THE WEATHER GRID LOOKS SCARIER THAN THE REALITY OF THE SITUATION. STILL...WE COULD SEE A LIGHT ACCUMULATION OF SNOW OR ICE NORTH OF I40 AND OVER PARTS OF THE NC MTNS FRIDAY NIGHT...BUT THE PCPN IS SO LIGHT I DON/T EVEN PLAN TO MENTION IT IN THE HWO ATTM. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... AS OF 230 AM EST WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SUNDAY WITH WHATS LEFT OF AN UPPER SHORTWAVE MOVING OUT OVER THE ATLANTIC AND UPPER RIDGING BUILDING OVER THE GULF OF MEXICO AND SE CONUS. THE LONG RANGE MODELS ARE TRYING TO CLOSE OFF AN H5 LOW OVER EXTREME SOUTHERN BRITISH COLUMBIA EARLY SUNDAY WITH THE NEWER RUN OF THE GFS BEING MORE PRONOUNCED. AS WE MOVE INTO MONDAY...HEIGHTS BEGIN TO LOWER AGAIN AS A COMPLEX UPPER TROF PATTERN MOVES SE ACROSS THE FAR NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THE MODELS INDICATE THAT THE MAIN TROF AXIS WILL LIKELY BE NORTH OF THE CAROLINAS BY LATE TUES/EARLY WED AND PERSIST OVER THE REGION THRU DAY 7. OVERALL...THE LONG RANGE MODELS APPEAR TO BE COMING INTO BETTER AGREEMENT WRT THE PROGRESSION AND TIMING OF THIS UPPER TROF SYSTEM...WITH THE GFS BEING MORE AMPLIFIED AND BRINGING THE SYSTEM FARTHER SOUTH COMPARED TO THE ECMWF. AT THE SFC...THE HIGH CENTERED OVER NEW ENGLAND HELPING TO PRODUCE A COLD AIR WEDGE PATTERN OVER THE CAROLINAS WILL BE MOVING WELL OFF THE COAST BY EARLY SUN. THE MODELS CONTINUE TO MAINTAIN ANOTHER BERMUDA TYPE HIGH CENTERED TO OUR EAST ON SUN AND EARLY MON. THEY ALSO SPIN UP A LOW OVER THE SOUTHERN MISS RIVER VALLEY EARLY MON AND MOVE IT OVER THE CWFA BY MON AFTERNOON. WHAT HAPPENS OVER THE NEXT 24 TO 36HRS VARIES CONSIDERABLY BETWEEN THE GFS AND ECMWF. THE GFS KEEPS THE LOW AND ITS ASSOCIATED REGION OF BROAD AND DEEP MOISTURE OVER THE FCST AREA THRU TUES AFTERNOON BEFORE MOVING IT NE AND OFFSHORE...WHILE THE ECMWF AND CMC MOVE IT OFFSHORE BY MON EVENING WITH DRIER HIGH PRESSURE SPREADING OVER THE REGION IN ITS WAKE ON TUES. BOTH MODELS AGREE THAT THE REMAINDER OF THE FCST SHOULD BE DRY HIGH PRESSURE OVER THE AREA ON WED. TEMPS WILL START OUT WELL ABOVE NORMAL FOR EARLY MARCH WITH HIGHS ON SUN IN THE MID 60S FOR THE LOWER ELEVATIONS AND UPPER 50S TO LOW 60S FOR THE HIGHER TERRAIN. BY THE END OF THE PERIOD...I ANTICIPATE THAT VALUES WILL COOL BACK DOWN BELOW CLIMATOLOGY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...LOW VFR CLOUDINESS LINGERS THIS MRNG IN WARM UPGLIDE PRIOR TO ARRIVAL OF COLD FRONT. PRECIP CHANCES DUE TO THE UPGLIDE ARE LOW...WITH SHORT TERM GUID KEEPING MOST OF THE RESPONSE WELL SOUTH. A FEW SPRINKLES OR BRIEF -SHRA ARE POSSIBLE THRU MID MRNG...BUT WITHOUT RESTRICTIONS. MAINLY NE WINDS PRIOR TO THE FROPA...POSSIBLY KEPT CLOSER TO 090 DUE TO LEE TROUGHING. NW WINDS AND CLEARING SKIES BY MIDDAY POST FROPA. SKC LIKELY OVERNIGHT...BUT NAM/GFS BOTH TRY TO DEVELOP SOME SPOTTY LOW VFR CLOUDS DUE TO LLVL CONVERGENCE IN THE LEE OF THE MTNS. THIS IS A BIT UNUSUAL AND IS NOT BACKED UP BY MOS SO WILL NOT REFLECT IN TAF. ELSEWHERE...PRECIP CHANCES THIS AM ARE TOO LOW TO MENTION EXCEPT AT KAND...WHICH WILL BE NEARER THE BEST LIFT/MSTR ASSOCIATED WITH WARM ADVECTION OVER THE DEEP SOUTH. CIGS LIKELY TO STAY LOW VFR AT WORST...BUT WILL MONITOR UPSTREAM OBS FOR LOWER CIGS WHICH MIGHT BE ASSOCIATED WITH PRECIP. NW FLOW INTO THE MTNS WILL PRODUCE A FEW -SHSN BUT THESE SHOULD BE VERY LIGHT AND MAY NOT CAUSE SGFNT REDUCTION IN VSBY. EXCEPT AT KAVL WHICH REMAINS NW...NELY WINDS WILL PREVAIL UNTIL THE FRONT PASSES AND SKIES GRADUALLY CLEAR. POST FROPA WINDS WILL MAINLY BE NW BEFORE VEERING TONIGHT. OUTLOOK...DRY/VFR THU-FRI...BUT PRECIPITATION AND ASSOCIATED RESTRICTIONS ARE POSSIBLE EARLY SAT. CONFIDENCE TABLE... 11-17Z 17-23Z 23-05Z 05-11Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... A MODIFIED ARCTIC AIR MASS WILL RESULT IN DEWPOINTS IN THE SINGLE DIGITS AND TEENS THIS AFTERNOON AND AGAIN THU AFTERNOON. WITH A RELATIVELY COOL AIR MASS IN PLACE...RH IS EXPECTED TO DIP TO 25 PERCENT OR LESS ONLY BRIEFLY TODAY. MEANWHILE...GUSTY MORNING WINDS SHOULD BEGIN TO DIMINISH BY AFTERNOON. AT THIS TIME...THE GUSTY WINDS AND LOWEST RH ARE NOT EXPECTED TO OVERLAP TODAY. HOWEVER...AS THE AIR MASS BEGINS TO WARM ON THURSDAY...RH IS EXPECTED TO FALL BELOW 20 PERCENT IN MOST AREAS DURING THE AFTERNOON. IN ADDITION... W/NW WINDS WILL BEGIN TO INCREASE AHEAD OF ANOTHER DRY COLD FRONT DURING THE AFTERNOON. WINDS MAY GUST AS HIGH AS 30 MPH IN THE MTNS...AND TO AROUND 20 MPH IN THE PIEDMONT. CRITICAL WIND AND RH MAY OVERLAP FOR SEVERAL HOURS ACROSS THE MTNS AND NC FOOTHILLS THU AFTERNOON. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JPT NEAR TERM...WIMBERLEY SHORT TERM...MCAVOY LONG TERM...JPT AVIATION...WIMBERLEY FIRE WEATHER...MCAVOY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
536 AM CST WED FEB 26 2014 .DISCUSSION... SEE 12Z AVIATION DISCUSSION. && .AVIATION... FIRST S/WV IS EXITING THE AREA AND WILL TAKE A BULK OF THE RAINFALL WITH IT. A SECOND S/WV WILL BE APPROACHING THE AREA LATER THIS MORNING BUT IT APPEARS THAT MOST OF THE PRECIP WILL TARGET THE SOUTHERN TAF SITES. STILL SOME UNCERTAINTY WITH REGARD TO REDEVELOPMENT AS THE RAP/NAM AND ECMWF ARE CONSIDERABLY DRIER THAN THE GFS. MAINLY MVFR CIGS ARE EXPECTED TODAY WITH PERIODS OF IFR. VFR CONDS EXPECTED TO DEVELOP OVERNIGHT WITH VFR CONDS EXPECTED ON THURSDAY. WINDS WILL BE GUSTY THIS MORNING WITH SPEEDS DECREASING IN THE AFTN AND DECOUPLING TO NEAR CALM OVERNIGHT. 43 && .PREV DISCUSSION... /ISSUED 453 AM CST WED FEB 26 2014/ DISCUSSION... THE RADAR HAS FILLED IN NICELY THIS MORNING WITH SOME ISOLATED THUNDER NORTH OF INTERSTATE 10. THIS RAINFALL IS THE RESULT OF A PASSING SURFACE COLD FRONT IN COMBINATION WITH MULTIPLE UPPER LEVEL DISTURBANCES MOVING ACROSS THE AREA. THE COLD FRONT HAS NOW MOVED OFFSHORE WITH TEMPERATURES FALLING IN ITS WAKE. A HAND ANALYSIS AT 250MB FROM 0Z THIS MORNING STILL SHOWS THE SUBTROPICALJET WITH AN UNFAVORABLE ANTICYCLONIC CURVATURE TO IT. THE JET IS FORECASTED TO FLATTEN THOUGH AND ALLOW SOUTHEAST TEXAS TO FALL BRIEFLY INTO A RRQ THIS MORNING INTO EARLY AFTERNOON BEFORE EXITING THE AREA THIS EVENING. ANOTHER ROUND OF RAIN HAS STARTED TO FIRE OUT NEAR THE DEL RIO AREA AND IS ALSO A RESULT OF A PASSING UPPER LEVEL DISTURBANCE. THE DISTURBANCE IS FORECASTED TO MOVE TO THE EAST DURING THE DAY TODAY AND BRING SOME MORE RAINFALL TO THE AREA THIS AFTERNOON. GFS AND NAM OMEGA FIELDS HINT AT THE SOUTHERN HALF OF THE AREA TO BE THE MOST LIKELY SPOT FOR THE RAINFALL THIS AFTERNOON. THE HRRR AND TEXAS TECH WRF WOULD ALSO TEND TO AGREE WITH THIS. MODELS ARE ALSO INDICATING THE POSSIBILITY OF SOME LIGHT STRATIFORM RAIN THROUGH THE WASHINGTON... MONTGOMERY... SAN JACINTO COUNTY AREA. ONLY CONCERN WITH THIS SOLUTION IS THAT BOTH GFS AND NAM MODEL SOUNDINGS SHOW DRY AIR WORKING ITS WAY SOUTH IN THE 850 TO 700MB LAYER. TEMPERATURES WILL BE HOLDING STEADY OR DROPPING THROUGH THE DAY TODAY AS SURFACE HIGH PRESSURE SETTLES OVERHEAD. MODELS ARE ALSO HINTING AT THE CLOUDS TRYING TO BREAK BY THURSDAY MORNING. THIS IN COMBINATION WITH LIGHT WINDS WILL MAKE THURSDAY MORNING COLD. ON FRIDAY A SHORTWAVE WILL MOVE TO THE SOUTHEAST AND CROSS THE TEXARKANA AREA FRIDAY AFTERNOON. BOTH GFS AND NAM SOUNDINGS LOOK TO HAVE A SIZABLE CAP IN PLACE AROUND THIS TIME WHICH WOULD TEND TO INHIBIT THUNDERSTORM DEVELOPMENT. ISOLATED SHOWERS COULD BE POSSIBLE IN OUR NORTHEASTERN ZONES BUT CHANCES LOOK LOW AS OF NOW. AN UPPER LEVEL LOW WILL MOVE INTO SOUTHERN CALIFORNIA SATURDAY AFTERNOON AND BEGIN TO SHEAR OUT AS IT PROGRESSES EASTWARDS. THE ECMWF AND CANADIAN REMAIN MORE PROGRESSIVE WITH THE FEATURE WHILE THE GFS HOLDS THE SHORTWAVE UP A BIT. IF THE GFS IS RIGHT A SURFACE COLD FRONT WILL ALSO BE HELP UP UNTIL LATE MONDAY MORNING. THE ECMWF AND CANADIAN FAVOR THE COLD FRONT MAKING IT LATE SUNDAY EVENING OR EARLY MONDAY MORNING. GFS AND ECMWF SOUNDINGS BOTH SUPPORT SHOWERS AND THUNDERSTORMS WITH THIS FRONT. FOR NOW HAVE LEANED TOWARDS THE ECMWF AND CANADIAN SOLUTION. 23 MARINE... SEA FOG HAS ERODED AS STRONG NORTH WINDS DEVELOP IN THE WAKE OF A DEPARTING COLD FRONT. A TIGHT PRESSURE GRADIENT WILL PRODUCE STRONG NORTH WINDS THROUGH THE DAY. WILL MAINTAIN AN SCA FOR ALL WATERS THROUGH 18Z AND THEN THE GULF WATERS THROUGH 00Z. THE GRADIENT WILL RELAX TONIGHT AS HIGH PRESSURE NEARS THE NORTHERN GULF COAST. THE HIGH WILL DRIFT EAST AND ONSHORE WINDS WILL RETURN ON THURSDAY AND PERSIST THROUGH THE WEEKEND. COULD BE ANOTHER BRIEF EPISODE OF SEA FOG ON SUNDAY. THE NEXT COLD FRONT WILL CROSS THE COASTAL WATERS LATE SUNDAY NIGHT OR EARLY MONDAY. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 44 32 57 43 70 / 50 20 10 10 10 HOUSTON (IAH) 49 35 59 44 69 / 50 30 10 10 10 GALVESTON (GLS) 54 41 55 53 66 / 60 40 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT SHOULD EXERCISE CAUTION FROM NOON CST TODAY THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY... MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT SHOULD EXERCISE CAUTION FROM THIS EVENING THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. SMALL CRAFT SHOULD EXERCISE CAUTION LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...23 AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
453 AM CST WED FEB 26 2014 .DISCUSSION... THE RADAR HAS FILLED IN NICELY THIS MORNING WITH SOME ISOLATED THUNDER NORTH OF INTERSTATE 10. THIS RAINFALL IS THE RESULT OF A PASSING SURFACE COLD FRONT IN COMBINATION WITH MULTIPLE UPPER LEVEL DISTURBANCES MOVING ACROSS THE AREA. THE COLD FRONT HAS NOW MOVED OFFSHORE WITH TEMPERATURES FALLING IN ITS WAKE. A HAND ANALYSIS AT 250MB FROM 0Z THIS MORNING STILL SHOWS THE SUBTOPICAL JET WITH AN UNFAVORABLE ANTICYCLONIC CURVATURE TO IT. THE JET IS FORECASTED TO FLATTEN THOUGH AND ALLOW SOUTHEAST TEXAS TO FALL BRIEFLY INTO A RRQ THIS MORNING INTO EARLY AFTERNOON BEFORE EXITING THE AREA THIS EVENING. ANOTHER ROUND OF RAIN HAS STARTED TO FIRE OUT NEAR THE DEL RIO AREA AND IS ALSO A RESULT OF A PASSING UPPER LEVEL DISTURBANCE. THE DISTURBANCE IS FORECASTED TO MOVE TO THE EAST DURING THE DAY TODAY AND BRING SOME MORE RAINFALL TO THE AREA THIS AFTERNOON. GFS AND NAM OMEGA FIELDS HINT AT THE SOUTHERN HALF OF THE AREA TO BE THE MOST LIKELY SPOT FOR THE RAINFALL THIS AFTERNOON. THE HRRR AND TEXAS TECH WRF WOULD ALSO TEND TO AGREE WITH THIS. MODELS ARE ALSO INDICATING THE POSSIBILITY OF SOME LIGHT STRATIFORM RAIN THROUGH THE WASHINGTON... MONTGOMERY... SAN JACINTO COUNTY AREA. ONLY CONCERN WITH THIS SOLUTION IS THAT BOTH GFS AND NAM MODEL SOUNDINGS SHOW DRY AIR WORKING ITS WAY SOUTH IN THE 850 TO 700MB LAYER. TEMPERATURES WILL BE HOLDING STEADY OR DROPPING THROUGH THE DAY TODAY AS SURFACE HIGH PRESSURE SETTLES OVERHEAD. MODELS ARE ALSO HINTING AT THE CLOUDS TRYING TO BREAK BY THURSDAY MORNING. THIS IN COMBINATION WITH LIGHT WINDS WILL MAKE THURSDAY MORNING COLD. ON FRIDAY A SHORTWAVE WILL MOVE TO THE SOUTHEAST AND CROSS THE TEXARKANA AREA FRIDAY AFTERNOON. BOTH GFS AND NAM SOUNDINGS LOOK TO HAVE A SIZABLE CAP IN PLACE AROUND THIS TIME WHICH WOULD TEND TO INHIBIT THUNDERSTORM DEVELOPMENT. ISOLATED SHOWERS COULD BE POSSIBLE IN OUR NORTHEASTERN ZONES BUT CHANCES LOOK LOW AS OF NOW. AN UPPER LEVEL LOW WILL MOVE INTO SOUTHERN CALIFORNIA SATURDAY AFTERNOON AND BEGIN TO SHEAR OUT AS IT PROGRESSES EASTWARDS. THE ECMWF AND CANADIAN REMAIN MORE PROGRESSIVE WITH THE FEATURE WHILE THE GFS HOLDS THE SHORTWAVE UP A BIT. IF THE GFS IS RIGHT A SURFACE COLD FRONT WILL ALSO BE HELP UP UNTIL LATE MONDAY MORNING. THE ECMWF AND CANADIAN FAVOR THE COLD FRONT MAKING IT LATE SUNDAY EVENING OR EARLY MONDAY MORNING. GFS AND ECMWF SOUNDINGS BOTH SUPPORT SHOWERS AND THUNDERSTORMS WITH THIS FRONT. FOR NOW HAVE LEANED TOWARDS THE ECMWF AND CANADIAN SOLUTION. 23 && .MARINE... SEA FOG HAS ERODED AS STRONG NORTH WINDS DEVELOP IN THE WAKE OF A DEPARTING COLD FRONT. A TIGHT PRESSURE GRADIENT WILL PRODUCE STRONG NORTH WINDS THROUGH THE DAY. WILL MAINTAIN AN SCA FOR ALL WATERS THROUGH 18Z AND THEN THE GULF WATERS THROUGH 00Z. THE GRADIENT WILL RELAX TONIGHT AS HIGH PRESSURE NEARS THE NORTHERN GULF COAST. THE HIGH WILL DRIFT EAST AND ONSHORE WINDS WILL RETURN ON THURSDAY AND PERSIST THROUGH THE WEEKEND. COULD BE ANOTHER BRIEF EPISODE OF SEA FOG ON SUNDAY. THE NEXT COLD FRONT WILL CROSS THE COASTAL WATERS LATE SUNDAY NIGHT OR EARLY MONDAY. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 44 32 57 43 70 / 50 20 10 10 10 HOUSTON (IAH) 49 35 59 44 69 / 50 30 10 10 10 GALVESTON (GLS) 54 41 55 53 66 / 60 40 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT SHOULD EXERCISE CAUTION FROM NOON CST TODAY THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY... MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT SHOULD EXERCISE CAUTION FROM THIS EVENING THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. SMALL CRAFT SHOULD EXERCISE CAUTION LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...23 AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS SPOKANE WA
258 AM PST Wed Feb 26 2014 .SYNOPSIS... Dry weather is expected today with a little bit of warming for most locations. The dry lull in the weather will come to an end on Thursday. With warmer temperatures expected, rain will be the primary precipitation type. A return of colder weather is expected Friday night into Saturday with a good chance of snow for most locations. Meanwhile much colder air will return for the weekend with Daytime temperatures this weekend with readings in the teens to middle 20s. Breezy winds will make it feel even colder especially over portions of the North Idaho Panhandle. && .DISCUSSION... Today through tonight...Latest satellite images would suggest we are looking at a fairly quiet day as 500 mb ridge will remain fixed over the region. The main focus will revolve around negatively tilted trough axis and warm front currently pushing through SW Oregon. The main impact this feature will have on our forecast area today will be a slowly increasing cloud trend from the southwest. Despite this increasing cloud trend, there really is little of any threat of precipitation. The main weather story will thus revolve around the tricky temperature forecast. The region remains split between a cool and very dry air mass fixed over the northern 2/3rds of Washington and most of the Idaho Panhandle. Meanwhile...a warmer and more moisture laden atmosphere lingers over extreme SE Washington and adjacent portions of the Idaho Panhandle. These locations...including Lewiston and Pullman were seeing dewpoints around 30 degrees with similarly mild temperatures. Meanwhile the remainder of the forecast area was seeing dewpoint readings in the mid teens to single digits and cooler temperatures. The main challenge is will this milder air to our south retake most of the forecast area through the day as the front moves in from the south. Certainly the models are consistent on bringing significant warming to the 850-700 mb layer...but will this translate to the ground. Not confident it will as the surface pressure gradients will likely keep most of the winds out of the north to northeast...which isn`t real favorable for significant warming....despite the warming aloft. If the winds were strong enough this warming aloft would readily mix to the ground...but surface wind guidance is generally fairly weak today. We will hedge our forecasts toward the cooler guidance solutions by generally keep highs a little warmer than what we experienced yesterday. For tonight...the shortwave trough and associated front continue to drift across the forecast area from the southwest but it weakens significantly as it does. Whether or not the front will have enough juice and lifting by the time it moves into our region is the question. Models are all over the board with this feature as far as precipitation goes...however most would agree that if precipitation were to occur the best chances would occur near the Cascades due the proximity of the offshore trough. This would lead to the best moisture availability as well as the best upslope flow and isentropic ascent. If anything does occur it should be light...with better chances arriving after sunrise Thursday. fx Thursday through Tuesday: Fairly low confidence in the forecast. By Thursday the ridge is breaking down with a closed low moving into Southern Oregon. This will bring an increased chance of precipitation across southern WA and central ID on Thursday. Meanwhile an arctic front will be nearing north ID. By Friday it will be the convergence of two systems. The moist system from the south colliding with the arctic air from Canada. Models are differing on precipitation location and amounts, and it could vary greatly depending on where they converge. Have increased chance of precip across southeastern WA and the southern ID Panhandle for now, but higher chances of precip may need to be brought further north. Snow levels will lower through the day. Looks like the northern zones will start and remain as snow, and the southern zones starting out with snow levels btwn 3-4k ft and then lowering down to near the valley floors by late afternoon/early evening. Lets not forget the winds either. By Friday afternoon we get a very strong northeast to southwest gradient which will create breezy to windy northeast winds for the Purcell Trench, the Spokane/COE area, and down into portions of the Palouse and Columbia Basin through at least early Sunday morning. This arctic front is quite different from "normal" dry arctic intrusions we see. This one will have lots of moisture around to keep at least a slight chance of snow in the forecast through the weekend. Have lowered temperatures as well, but not going as cold as we could possibly see because am expecting more cloud cover than what we would normally see. The cold air will remain over the area through Monday, though it will have moderated a bit by Monday. Monday into Tuesday we get a broad ridge building into the area with warmer temperatures inching towards us. There doesn`t seem to be anything to really scour out the cold temps however so keep temperatures well below average for this time of the year. /Nisbet && .AVIATION... 12Z TAFS: Low clouds with MVFR cigs will likely persist through at least through 19z and perhaps longer for PUW and LWS. Satellite imagery shows clouds actually expanding which suggests they may last longer than previously anticipated despite the light downslope east winds. The latest HRRR clears the clouds after 19z...but this is a typical diurnal trend the model has and typically does not handle low level moisture all that well. We went with a clearing trend a little later than model suggests but confidence is not high. The other question is will these MVFR cigs make their way north to GEG SFF and COE. Low level gradients out of the NE suggest they will remain south of the airports...but this needs to be watched as the cloud deck slowly expands into the wind. Other than these issues...look for cloudy skies and slowly lowering cigs at all sites through fcst period. Condtions will generally remain VFR though. fx && .PRELIMINARY POINT TEMPS/POPS... Spokane 35 25 39 29 34 10 / 0 10 20 30 50 30 Coeur d`Alene 35 27 40 27 32 10 / 0 10 20 30 50 30 Pullman 40 32 42 33 39 17 / 0 10 40 50 60 50 Lewiston 46 35 47 37 46 27 / 10 20 50 60 50 50 Colville 39 25 42 29 39 15 / 0 10 10 20 30 20 Sandpoint 36 23 40 25 31 11 / 0 0 10 30 50 20 Kellogg 38 28 39 28 31 8 / 0 20 40 60 70 50 Moses Lake 41 28 45 33 43 23 / 0 10 20 30 30 20 Wenatchee 37 28 44 33 41 25 / 10 10 20 20 40 30 Omak 36 22 40 30 39 21 / 0 0 10 20 30 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
920 AM PST WED FEB 26 2014 .UPDATE... LOWERED TEMPERATURES FOR TODAY. && .SYNOPSIS... AN UNSETTLED WEATHER PATTERN WILL CONTINUE. RAIN AND HIGHER ELEVATION SNOW ARE EXPECTED AT TIMES THROUGH AT LEAST THE WEEKEND. THE NEXT SYSTEM WILL MOVE INTO THE AREA ON FRIDAY AND SATURDAY WITH BETTER CHANCES OF PRECIPITATION ACROSS THE REGION AND EVEN A FEW THUNDERSTORMS. && .DISCUSSION... INCREASING CLOUDS WILL REDUCE HEATING TODAY. RAIN HAS REACHED SOUTH BAKERSFIELD AT THIS TIME...AND THE RAIN WILL SUPPRESS THE SOUTHERLY SURFACE FLOW. TEMPERATURES HAVE BEEN LOWERED OVER THE REGION AND ARE NOW CLOSER TO 12Z GUIDANCE. POPS HAVE BEEN RAISED FOR THE SOUTH END OF THE SAN JOAQUIN VALLEY DUE TO EARLIER ARRIVAL OF PRECIPITATION. && .AVIATION... INCREASING CLOUDS WITH GRADUALLY LOWERING CEILINGS...AREAS OF MVFR AND LOCAL IFR CONDITIONS DEVELOPING IN PRECIPITATION SPREADING IN FROM THE WEST AFTER 18Z WEDNESDAY ACROSS THE CENTRAL CA INTERIOR. && .PREV DISC... /ISSUED 846 AM PST WED FEB 26 2014/ DISCUSSION...125 KT JET THAT IS UNDERCUTTING OFFSHORE STORM IS PUSHING COLD FRONT AND ASSOCIATED RAIN BAND MORE QUICKLY EASTWARD THAN ORIGINALLY ANTICIPATED. THE GFS AND HRRR MODELS SEEM TO HAVE A MUCH BETTER HANDLE ON THIS SO WILL USE THESE SOLUTIONS FOR GUIDANCE. ALTHO SW WINDS HAVE DIMINISHED SOMEWHAT ON THE WEST SIDE OF THE SJ VLY...THERE WILL BE LOCAL GUSTS TO 40 MPH FOR THE NEXT HR OR SO. HOWEVER...THE ONSET OF RAIN WILL STABILIZE WINDS IN THIS PORTION OF THE CWA TODAY. REMAINDER OF FORECAST LOOKS ON TRACK. && .AIR QUALITY ISSUES... NONE. && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM. THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 02-26 83:1888 44:1962 53:1995 25:1971 KFAT 02-27 79:1992 45:1996 54:2006 26:1962 KFAT 02-28 79:1926 51:1971 59:1986 28:1962 KBFL 02-26 80:1992 43:1962 56:1968 30:1971 KBFL 02-27 83:1980 46:1962 58:1988 24:1893 KBFL 02-28 81:1926 49:1945 56:1968 22:1893 && .HNX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 4 PM PST THURSDAY ABOVE 7000 FEET FOR THE SOUTHERN SIERRA NEVADA FROM YOSEMITE TO THE KERN COUNTY LINE /CAZ096-097/. WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH LATE SATURDAY NIGHT ABOVE 6000 FEET FOR THE SOUTHERN SIERRA NEVADA FROM YOSEMITE TO THE KERN COUNTY LINE /CAZ096-097/. HIGH WIND WATCH FROM THURSDAY EVENING THROUGH FRIDAY AFTERNOON FOR THE KERN COUNTY MOUNTAINS...MAINLY NEAR THE GRAPEVINE /CAZ095/. WIND ADVISORY UNTIL NOON PST TODAY FOR THE WEST SIDE OF THE SAN JOAQUIN VALLEY /CAZ089-091/. && $$ PUBLIC...SANGER AVN/FW...DURFEE PREV DISCUSSION...DURFEE SYNOPSIS...BSO WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS ALBANY NY
1248 PM EST WED FEB 26 2014 .SYNOPSIS... A CLIPPER LOW CONTINUES TO MOVE ACROSS SOUTHERN QUEBEC THIS AFTERNOON...AS ITS COLD FRONT MOVES THROUGH NEW ENGLAND WITH A REINFORCING SHOT OF ARCTIC AIR BEHIND IT. ANOTHER CLIPPER WILL BRING A CHANCE OF MORE SNOW SHOWERS AND SNOW SQUALLS ON THURSDAY WITH SOME BITTERLY COLD AIR FOR EASTERN NEW YORK AND WESTERN NEW ENGLAND THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1233 PM EST...CLIPPER TYPE LOW CONTINUES TO MOVE ACROSS SRN QUEBEC TOWARDS NRN ME AND NEW BRUNSWICK. THE COLD FRONT HAS MOVED THROUGH WITH DIFFUSE SNOW SHOWERS AND FLURRIES...ASIDE FROM A LAKE EFFECT SNOWBAND COMING OFF LAKE ONTARIO INTO THE TUG HILL PLATUEAU INTO THE WRN DACKS AND MOST SPECIFICALLY NRN HERKIMER CO. THE INLAND EXTENT HAS BEEN DIFFICULT DOWNSTREAM. THE LAKE EFFECT SNOW ADVISORY REMAINS IN EFFECT FOR HERKIMER CO...BUT WE MAY DROP SRN HERKIMER WITH THE NEXT UPDATE...AS THE 260-270 DEG TRAJECTORY FAVORS NRN HERKIMER. THE LATEST HRRR GUIDANCE SHOWS THE BAND WEAKENING BY THIS EVENING AND LIFTING NORTHWARD. WE ALSO LOWERED AMOUNTS TO 3 TO 6 INCHES FOR THE AREA. MOST OF THE SCT SNOW SHOWERS PRODUCED LESS THAN AN INCH OF SNOW. PLEASE SEE OUR LATEST PNS...WITH ISOLD HIGHER AMOUNTS. TEMPS LOOKS ON TRACK WITH BRISK CONDITIONS AND HIGHS A SOLID 10 TO 15 DEGREES BELOW NORMAL. H850 TEMPS CRASH AGAIN TO -19C TO -22C OVER THE FCST AREA BY THE LATE PM. IT WILL ALSO BECOME WINDY IN THE WAKE OF THE FRONT WITH UPSLOPE SNOW SHOWERS POSSIBLE OVER THE TACONICS...BERKSHIRES...AND SRN GREENS. IN ADDITION TO LAKE EFFECT SNOWS THERE IS THE SLIGHT POSSIBILITY OF A WINDEX TYPE EVENT IN THE WAKE OF THE ARCTIC FRONT AS RH VALUES IN THE LOWER LEVELS ARE GREATER THAN 70 PERCENT AND T1-T5 LAYER TEMPS DIFFER BY MORE THAN 10 C. IT WILL BE VERY CHILLY TODAY WITH HIGHS ONLY RANGING FROM THE LOW TO MID TEENS NORTHWEST TO THE LOW TO MID 20S SOUTHEAST. TONIGHT....BLUSTERY CONDITIONS WILL PERSIST THROUGH THE EVENING HOURS AND THE LAKE EFFECT BAND WILL COME TO AN END AS A WEAK RIDGE OF HIGH PRESSURE BUILDS IN FROM THE SOUTH AHEAD OF THE NEXT CLIPPER TYPE SYSTEM WHICH WILL ALREADY BE MOVING INTO THE SE ONTARIO AND THE ERN GREAT LAKES REGION BY LATE TONIGHT. WIND CHILL VALUES WILL BE CLOSE TO ADVISORY CRITERIA AND MAINLY ACROSS THE WESTERN ADIRONDACKS. OVERNIGHT LOWS ARE EXPECTED TO RANGE FROM 10 BELOW TO 5 ABOVE ZERO. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... THU-THU NIGHT....THE SECOND CLIPPER TYPE SYSTEM IMPACTS THE FA AS IT MOVES ACROSS SOUTHERN QUEBEC...NRN NY AND NRN NEW ENGLAND SWINGING ANOTHER ARCTIC COLD FRONT THROUGH OUR REGION. THIS SYSTEM IS EVEN STRONGER THAN THE FIRST CLIPPER TYPE SYSTEM AND LOOKS TO SET UP A CLASSIC WINDEX EVENT IN THE WAKE OF THE COLD FRONT WHICH WILL BE ENHANCED BY A SECONDARY TROUGH OF LOW PRESSURE. THE BEST MOISTURE CONVERGENCE LOOKS LIKE IT WILL BE OVER THE WRN DACKS AGAIN...WHERE A FEW INCHES OF SNOW LOOK LIKELY. MOST OTHER LOCATIONS WILL RECEIVE A DUSTING TO AN TWO INCHES. THE WIND FIELDS STRENGTHEN IN THE WAKE OF THE CLIPPER WITH SW WINDS SHIFTING TO THE WEST WITH THE FRONTAL PASSAGE IN THE AFTERNOON. WEST WINDS OF 15 TO 25 MPH WITH SOME GUSTS TO 35 TO 40 MPH WILL BE POSSIBLE DUE TO FUNNELING DOWN THE MOHAWK VALLEY INTO THE CAPITAL REGION INTO THE CNTRL TACONICS...AND BERKSHIRES. THESE GUSTY WINDS ARE ALSO EXPECTED IN THE ERN AND NRN CATSKILLS. HIGHS ON THURSDAY WILL GENERALLY BE IN THE UPPER TEENS TO UPPER 20S. LOWS THURSDAY NIGHT WILL BE IN THE 10 BELOW ZERO TO 5 ABOVE ZERO RANGE WITH WIND CHILL VALUES REACHING ADVISORY CRITERIA ACROSS SOME OF THE HIGHER TERRAIN. FRIDAY AND FRIDAY NIGHT HIGH PRESSURE WILL PROVIDE PLENTY OF SUNSHINE TO THE REGION ALTHOUGH IT WILL STILL BE VERY COLD AND BLUSTERY. EXPECT HIGH ON FRIDAY TO BE IN THE TEENS TO AROUND 20 WITH PERHAPS ONLY SINGLE DIGITS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. LOWS FRIDAY NIGHT WILL BE IN THE 10 BELOW TO 5 ABOVE ZERO RANGE ONCE AGAIN. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... BELOW TO MUCH BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE LONG TERM PORTION OF THE FORECAST. IN ADDITION...THE POTENTIAL FOR STORMINESS WILL INCREASE...ESP BY SUN NT-MON...AS SHORTWAVE ENERGY ORIGINATING OVER THE SOUTHWEST U.S. EJECTS RAPIDLY NORTHEASTWARD...AHEAD OF A LONG WAVE TROUGH PIVOTING SLOWLY E/SE ACROSS THE NORTHERN PLAINS. OVERALL...MODELS HAVE TRENDED SLIGHTLY SOUTHWARD WITH REGARD TO THEIR RESPECTIVE SURFACE FEATURES COMPARED TO 24 HOURS AGO /00Z 25 RUNS/. TAKING A LOOK AT SOME PV TRACES...IT APPEARS THAT ENERGY CURRENTLY DIGGING SOUTHWARD WELL SOUTHWEST OF THE ALEUTIAN ISLANDS WILL BE THE MAIN DRIVER FOR EARLY NEXT WEEK...AS THIS PV ANOMALY POSSIBLY REACHES SOUTHERN CA EARLY THIS WEEKEND...AS THE UPPER LEVEL TROUGH/LOW CURRENTLY FURTHER EAST SPLITS INTO TWO PIECES...ONE TRANSLATING NORTHWARD WELL OFF THE PACIFIC NW COAST...AND ANOTHER PIECE TRANSLATES EAST AND WEAKENS...AFFECTING OUR REGION ON SATURDAY. THE MODELS SEEM TO HANDLE THE DIGGING ENERGY DIFFERENTLY...WITH THE 00Z/26 ECMWF A BIT FASTER IN PROGRESSING THIS ENERGY OUT ACROSS THE SOUTHERN PLAINS AND EVENTUALLY OHIO VALLEY FOR SUN-MON...AND ALSO KEEPING THE ENERGY IN TACT A BIT LONGER...WHILE THE 00Z/26 GFS IS SLOWER...AND SEEMS TO WEAKEN/SHEAR THIS ENERGY FASTER WITH A SOMEWHAT FLATTER WAVE FOR AFFECTING THE REGION FOR LATE MON INTO TUE. HAVE SIDED CLOSER TO THE 00Z/26 WPC/ECMWF SOLUTIONS. EITHER WAY...IT APPEARS THAT WARM ADVECTION WELL AHEAD OF ANY SUCH WAVE SHOULD ALLOW CLOUDS AND PRECIP TO DEVELOP SUN NT...AND INTO MONDAY...BEFORE POSSIBLY TAPERING OFF LATE MON NT OR TUES. BASED ON CURRENT 00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE...SOUTHERN PORTIONS OF THE FORECAST AREA APPEAR TO BE MOST FAVORED FOR MODERATE OR GREATER AMOUNTS OF PRECIPITATION...BUT AGAIN...THIS SOUTHWARD MODEL TREND STARTED WITHIN THE LAST 24 HOURS...AND WOULD NOT BE SURPRISED TO ULTIMATELY SEE MODELS SOLUTIONS TREND BACK SLIGHTLY NORTHWARD AGAIN OVER THE NEXT 1-3 DAYS WITH REGARD TO THIS POTENTIAL STORM SYSTEM. HERE ARE SOME MORE SPECIFICS... SAT-SUN...THE FIRST WAVE IS EXPECTED TO WEAKEN...AND TRANSLATE RAPIDLY EAST/NORTHEAST ON SAT. A SURGE OF WEAK WARM ADVECTION SHOULD ALLOW FOR ABUNDANT CLOUDS AND SOME LIGHT SNOW/SNOW SHOWERS TO OVERSPREAD THE REGION LATE SAT MORNING INTO THE AFTERNOON...ESPECIALLY FOR AREAS NEAR AND WEST OF THE HUDSON RIVER. THE SNOW SHOWERS ARE EXPECTED TO SINK SOUTHWARD SAT NT AND EARLY SUNDAY...AS THE ASSOCIATED ARCTIC FRONTAL BOUNDARY ALSO DROPS SOUTH. WILL THEREFORE INDICATE CHC POPS FOR MOST AREAS FROM ALBANY N AND W...AND MAINLY SLIGHT CHC TO THE S/E THROUGH SAT...THEN CHC POPS ALL AREAS FOR SAT NT INTO EARLY SUN...WITH SOME LIKELY POPS FOR NW AREAS. THERE IS A POSSIBILITY THAT SNOW SHOWERS AND/OR AREAS OF LIGHT SNOW ACTUALLY TAPER OFF ACROSS NORTHERN AREAS SUNDAY AFTERNOON/EVENING...AS THE FRONT AND ASSOCIATED MID LEVEL FORCING SHIFTS FURTHER SOUTH. WILL THEREFORE TAPER POPS IN THE AFTERNOON FOR NORTHERN AREAS INTO THE SLIGHT CHC RANGE...WITH CHC POPS REMAINING FOR CENTRAL AND SOUTHERN AREAS. SUN NT-MON...THE AFOREMENTIONED SECOND WAVE SHOULD EJECT OUT OF THE SOUTHWEST U.S...AND WILL CONTINUE TRANSLATING E/NE...ALLOWING A LARGE AREA OF ISENTROPIC LIFT TO DEVELOP ACROSS THE REGION. THIS SHOULD ALLOW FOR SNOW TO OVERSPREAD THE REGION SUN NT...AND CONTINUE THROUGH MONDAY. SNOW SHOULD BE THE MAIN P-TYPE FOR MOST AREAS. BASED ON THE SLIGHT SOUTHWARD TREND OF THE 00Z/26 MODELS WITH REGARD TO STRONGEST MID LEVEL FORCING AND MOISTURE...HAVE ADDED LIKELY POPS ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA...WITH CHC POPS ELSEWHERE. TEMPS WILL REMAIN BELOW TO MUCH BELOW NORMAL THROUGH THE PERIOD. THE MILDEST DAY SHOULD BE SATURDAY...AHEAD OF THE INCOMING ARCTIC FRONTAL BOUNDARY...WITH MAX TEMPS REACHING THE LOWER 30S IN VALLEY AREAS...AND 20S ACROSS MOST HIGHER ELEVATIONS. FOR SAT NT/SUN AM...AS THE ARCTIC BOUNDARY SINKS SOUTHWARD...TEMPS SHOULD FALL INTO THE TEENS IN MOST AREAS...EXCEPT FOR SINGLE DIGITS ACROSS PORTIONS OF THE ADIRONDACKS. ON SUNDAY...MAX TEMPS SHOULD GENERALLY ONLY REACH THE 20S IN VALLEYS WITH TEENS ACROSS THE ADIRONDACKS. TEMPS SHOULD THEN FALL INTO THE SINGLE DIGITS TO MID TEENS SUN NT...AND THEN ONLY RISE INTO THE TEENS AND 20S FOR MONDAY...ALTHOUGH THERE IS THE POTENTIAL FOR EVEN COLDER MAX TEMPS IF ENOUGH LOW LEVEL ARCTIC AIR SEEPS SOUTHWARD INTO THE REGION IN THE WAKE OF THE WEEKEND WAVE...AND IF SNOW FALLS INTO THIS COLD AND RELATIVELY DRY LOW LEVEL AIR. EXPECT SINGLE DIGITS AND TEENS AGAIN FOR MON NT/TUE AM...WITH TUE MAXES MAINLY IN THE 20S IN VALLEYS...AND TEENS ACROSS HIGHER ELEVATIONS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... PREDOMINATELY VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD WITH SCATTERED SNOW SHOWERS DIMINISHING BY THIS EVENING. THIS AFTERNOON...WIDELY SCATTERED SNOW SHOWERS ASSOCIATED WITH A WEAK CLIPPER AND COLD FRONT WILL CONTINUE THROUGH THE AFTERNOON HOURS...ESPECIALLY AT KGFL WHERE SOME LAKE MOISTURE WILL ALSO BE TAPPED. HAVE INCLUDED A TEMPO GROUP AT KGFL UNTIL 20Z TO ACCOUNT FOR ANY BRIEF IFR REDUCTIONS IN HEAVIER SNOW SHOWERS...AND VCSH AT THE OTHER TAF SITES DUE TO WIDELY SCATTERED NATURE OF THE SHOWERS. WESTERLY WINDS WILL BE GUSTY THIS AFTERNOON...GUSTING 20-25 KNOTS EXCEPT AT KALB AND KPSF WHERE GUSTS AS HIGH AS 35 KNOTS WILL BE POSSIBLE. TONIGHT INTO THURSDAY...THE LOSS OF DAYTIME HEATING WILL HELP WINDS SUBSIDE THIS EVENING ALONG WITH GRADUALLY CLEARING SKIES AS WEAK HIGH PRESSURE BUILDS ACROSS THE REGION. MID CLOUDS WILL GRADUALLY BUILD FROM WEST TO EAST ACROSS THE REGION AHEAD OF ANOTHER APPROACHING CLIPPER SYSTEM WITH VCSH DEVELOPING BY THE END OF THE TAF PERIOD...ESPECIALLY NORTH AND WEST. WINDS WILL BE LIGHT AND VARIABLE TONIGHT GENERALLY LESS THAN 8 KNOTS BEFORE INCREASING AFTER DAYBREAK THURSDAY OUT OF THE SOUTHWEST AT 10-15 KNOTS WITH GUSTS 20-25 KNOTS. OUTLOOK... THURSDAY NIGHT: LOW OPERATIONAL IMPACT.BREEZY SLIGHT CHANCE OF SHSN. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. SUNDAY-MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN...SN. && .HYDROLOGY... NO HYDRO IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS. AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW FROM CLIPPER LOWS OR LAKE EFFECT. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ032-038. MA...NONE. VT...NONE. && $$ SYNOPSIS...11/WASULA NEAR TERM...11/NAS/WASULA SHORT TERM...11 LONG TERM...KL AVIATION...IRL HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1233 PM EST WED FEB 26 2014 .SYNOPSIS... A CLIPPER LOW CONTINUES TO MOVE ACROSS SOUTHERN QUEBEC THIS AFTERNOON...AS ITS COLD FRONT MOVES THROUGH NEW ENGLAND WITH A REINFORCING SHOT OF ARCTIC AIR BEHIND IT. ANOTHER CLIPPER WILL BRING A CHANCE OF MORE SNOW SHOWERS AND SNOW SQUALLS ON THURSDAY WITH SOME BITTERLY COLD AIR FOR EASTERN NEW YORK AND WESTERN NEW ENGLAND THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1233 PM EST...CLIPPER TYPE LOW CONTINUES TO MOVE ACROSS SRN QUEBEC TOWARDS NRN ME AND NEW BRUNSWICK. THE COLD FRONT HAS MOVED THROUGH WITH DIFFUSE SNOW SHOWERS AND FLURRIES...ASIDE FROM A LAKE EFFECT SNOWBAND COMING OFF LAKE ONTARIO INTO THE TUG HILL PLATUEAU INTO THE WRN DACKS AND MOST SPECIFICALLY NRN HERKIMER CO. THE INLAND EXTENT HAS BEEN DIFFICULT DOWNSTREAM. THE LAKE EFFECT SNOW ADVISORY REMAINS IN EFFECT FOR HERKIMER CO...BUT WE MAY DROP SRN HERKIMER WITH THE NEXT UPDATE...AS THE 260-270 DEG TRAJECTORY FAVORS NRN HERKIMER. THE LATEST HRRR GUIDANCE SHOWS THE BAND WEAKENING BY THIS EVENING AND LIFTING NORTHWARD. WE ALSO LOWERED AMOUNTS TO 3 TO 6 INCHES FOR THE AREA. MOST OF THE SCT SNOW SHOWERS PRODUCED LESS THAN AN INCH OF SNOW. PLEASE SEE OUR LATEST PNS...WITH ISOLD HIGHER AMOUNTS. TEMPS LOOKS ON TRACK WITH BRISK CONDITIONS AND HIGHS A SOLID 10 TO 15 DEGREES BELOW NORMAL. H850 TEMPS CRASH AGAIN TO -19C TO -22C OVER THE FCST AREA BY THE LATE PM. IT WILL ALSO BECOME WINDY IN THE WAKE OF THE FRONT WITH UPSLOPE SNOW SHOWERS POSSIBLE OVER THE TACONICS...BERKSHIRES...AND SRN GREENS. IN ADDITION TO LAKE EFFECT SNOWS THERE IS THE SLIGHT POSSIBILITY OF A WINDEX TYPE EVENT IN THE WAKE OF THE ARCTIC FRONT AS RH VALUES IN THE LOWER LEVELS ARE GREATER THAN 70 PERCENT AND T1-T5 LAYER TEMPS DIFFER BY MORE THAN 10 C. IT WILL BE VERY CHILLY TODAY WITH HIGHS ONLY RANGING FROM THE LOW TO MID TEENS NORTHWEST TO THE LOW TO MID 20S SOUTHEAST. TONIGHT....BLUSTERY CONDITIONS WILL PERSIST THROUGH THE EVENING HOURS AND THE LAKE EFFECT BAND WILL COME TO AN END AS A WEAK RIDGE OF HIGH PRESSURE BUILDS IN FROM THE SOUTH AHEAD OF THE NEXT CLIPPER TYPE SYSTEM WHICH WILL ALREADY BE MOVING INTO THE SE ONTARIO AND THE ERN GREAT LAKES REGION BY LATE TONIGHT. WIND CHILL VALUES WILL BE CLOSE TO ADVISORY CRITERIA AND MAINLY ACROSS THE WESTERN ADIRONDACKS. OVERNIGHT LOWS ARE EXPECTED TO RANGE FROM 10 BELOW TO 5 ABOVE ZERO. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... THU-THU NIGHT....THE SECOND CLIPPER TYPE SYSTEM IMPACTS THE FA AS IT MOVES ACROSS SOUTHERN QUEBEC...NRN NY AND NRN NEW ENGLAND SWINGING ANOTHER ARCTIC COLD FRONT THROUGH OUR REGION. THIS SYSTEM IS EVEN STRONGER THAN THE FIRST CLIPPER TYPE SYSTEM AND LOOKS TO SET UP A CLASSIC WINDEX EVENT IN THE WAKE OF THE COLD FRONT WHICH WILL BE ENHANCED BY A SECONDARY TROUGH OF LOW PRESSURE. THE BEST MOISTURE CONVERGENCE LOOKS LIKE IT WILL BE OVER THE WRN DACKS AGAIN...WHERE A FEW INCHES OF SNOW LOOK LIKELY. MOST OTHER LOCATIONS WILL RECEIVE A DUSTING TO AN TWO INCHES. THE WIND FIELDS STRENGTHEN IN THE WAKE OF THE CLIPPER WITH SW WINDS SHIFTING TO THE WEST WITH THE FRONTAL PASSAGE IN THE AFTERNOON. WEST WINDS OF 15 TO 25 MPH WITH SOME GUSTS TO 35 TO 40 MPH WILL BE POSSIBLE DUE TO FUNNELING DOWN THE MOHAWK VALLEY INTO THE CAPITAL REGION INTO THE CNTRL TACONICS...AND BERKSHIRES. THESE GUSTY WINDS ARE ALSO EXPECTED IN THE ERN AND NRN CATSKILLS. HIGHS ON THURSDAY WILL GENERALLY BE IN THE UPPER TEENS TO UPPER 20S. LOWS THURSDAY NIGHT WILL BE IN THE 10 BELOW ZERO TO 5 ABOVE ZERO RANGE WITH WIND CHILL VALUES REACHING ADVISORY CRITERIA ACROSS SOME OF THE HIGHER TERRAIN. FRIDAY AND FRIDAY NIGHT HIGH PRESSURE WILL PROVIDE PLENTY OF SUNSHINE TO THE REGION ALTHOUGH IT WILL STILL BE VERY COLD AND BLUSTERY. EXPECT HIGH ON FRIDAY TO BE IN THE TEENS TO AROUND 20 WITH PERHAPS ONLY SINGLE DIGITS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. LOWS FRIDAY NIGHT WILL BE IN THE 10 BELOW TO 5 ABOVE ZERO RANGE ONCE AGAIN. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... BELOW TO MUCH BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE LONG TERM PORTION OF THE FORECAST. IN ADDITION...THE POTENTIAL FOR STORMINESS WILL INCREASE...ESP BY SUN NT-MON...AS SHORTWAVE ENERGY ORIGINATING OVER THE SOUTHWEST U.S. EJECTS RAPIDLY NORTHEASTWARD...AHEAD OF A LONG WAVE TROUGH PIVOTING SLOWLY E/SE ACROSS THE NORTHERN PLAINS. OVERALL...MODELS HAVE TRENDED SLIGHTLY SOUTHWARD WITH REGARD TO THEIR RESPECTIVE SURFACE FEATURES COMPARED TO 24 HOURS AGO /00Z 25 RUNS/. TAKING A LOOK AT SOME PV TRACES...IT APPEARS THAT ENERGY CURRENTLY DIGGING SOUTHWARD WELL SOUTHWEST OF THE ALEUTIAN ISLANDS WILL BE THE MAIN DRIVER FOR EARLY NEXT WEEK...AS THIS PV ANOMALY POSSIBLY REACHES SOUTHERN CA EARLY THIS WEEKEND...AS THE UPPER LEVEL TROUGH/LOW CURRENTLY FURTHER EAST SPLITS INTO TWO PIECES...ONE TRANSLATING NORTHWARD WELL OFF THE PACIFIC NW COAST...AND ANOTHER PIECE TRANSLATES EAST AND WEAKENS...AFFECTING OUR REGION ON SATURDAY. THE MODELS SEEM TO HANDLE THE DIGGING ENERGY DIFFERENTLY...WITH THE 00Z/26 ECMWF A BIT FASTER IN PROGRESSING THIS ENERGY OUT ACROSS THE SOUTHERN PLAINS AND EVENTUALLY OHIO VALLEY FOR SUN-MON...AND ALSO KEEPING THE ENERGY IN TACT A BIT LONGER...WHILE THE 00Z/26 GFS IS SLOWER...AND SEEMS TO WEAKEN/SHEAR THIS ENERGY FASTER WITH A SOMEWHAT FLATTER WAVE FOR AFFECTING THE REGION FOR LATE MON INTO TUE. HAVE SIDED CLOSER TO THE 00Z/26 WPC/ECMWF SOLUTIONS. EITHER WAY...IT APPEARS THAT WARM ADVECTION WELL AHEAD OF ANY SUCH WAVE SHOULD ALLOW CLOUDS AND PRECIP TO DEVELOP SUN NT...AND INTO MONDAY...BEFORE POSSIBLY TAPERING OFF LATE MON NT OR TUES. BASED ON CURRENT 00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE...SOUTHERN PORTIONS OF THE FORECAST AREA APPEAR TO BE MOST FAVORED FOR MODERATE OR GREATER AMOUNTS OF PRECIPITATION...BUT AGAIN...THIS SOUTHWARD MODEL TREND STARTED WITHIN THE LAST 24 HOURS...AND WOULD NOT BE SURPRISED TO ULTIMATELY SEE MODELS SOLUTIONS TREND BACK SLIGHTLY NORTHWARD AGAIN OVER THE NEXT 1-3 DAYS WITH REGARD TO THIS POTENTIAL STORM SYSTEM. HERE ARE SOME MORE SPECIFICS... SAT-SUN...THE FIRST WAVE IS EXPECTED TO WEAKEN...AND TRANSLATE RAPIDLY EAST/NORTHEAST ON SAT. A SURGE OF WEAK WARM ADVECTION SHOULD ALLOW FOR ABUNDANT CLOUDS AND SOME LIGHT SNOW/SNOW SHOWERS TO OVERSPREAD THE REGION LATE SAT MORNING INTO THE AFTERNOON...ESPECIALLY FOR AREAS NEAR AND WEST OF THE HUDSON RIVER. THE SNOW SHOWERS ARE EXPECTED TO SINK SOUTHWARD SAT NT AND EARLY SUNDAY...AS THE ASSOCIATED ARCTIC FRONTAL BOUNDARY ALSO DROPS SOUTH. WILL THEREFORE INDICATE CHC POPS FOR MOST AREAS FROM ALBANY N AND W...AND MAINLY SLIGHT CHC TO THE S/E THROUGH SAT...THEN CHC POPS ALL AREAS FOR SAT NT INTO EARLY SUN...WITH SOME LIKELY POPS FOR NW AREAS. THERE IS A POSSIBILITY THAT SNOW SHOWERS AND/OR AREAS OF LIGHT SNOW ACTUALLY TAPER OFF ACROSS NORTHERN AREAS SUNDAY AFTERNOON/EVENING...AS THE FRONT AND ASSOCIATED MID LEVEL FORCING SHIFTS FURTHER SOUTH. WILL THEREFORE TAPER POPS IN THE AFTERNOON FOR NORTHERN AREAS INTO THE SLIGHT CHC RANGE...WITH CHC POPS REMAINING FOR CENTRAL AND SOUTHERN AREAS. SUN NT-MON...THE AFOREMENTIONED SECOND WAVE SHOULD EJECT OUT OF THE SOUTHWEST U.S...AND WILL CONTINUE TRANSLATING E/NE...ALLOWING A LARGE AREA OF ISENTROPIC LIFT TO DEVELOP ACROSS THE REGION. THIS SHOULD ALLOW FOR SNOW TO OVERSPREAD THE REGION SUN NT...AND CONTINUE THROUGH MONDAY. SNOW SHOULD BE THE MAIN P-TYPE FOR MOST AREAS. BASED ON THE SLIGHT SOUTHWARD TREND OF THE 00Z/26 MODELS WITH REGARD TO STRONGEST MID LEVEL FORCING AND MOISTURE...HAVE ADDED LIKELY POPS ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA...WITH CHC POPS ELSEWHERE. TEMPS WILL REMAIN BELOW TO MUCH BELOW NORMAL THROUGH THE PERIOD. THE MILDEST DAY SHOULD BE SATURDAY...AHEAD OF THE INCOMING ARCTIC FRONTAL BOUNDARY...WITH MAX TEMPS REACHING THE LOWER 30S IN VALLEY AREAS...AND 20S ACROSS MOST HIGHER ELEVATIONS. FOR SAT NT/SUN AM...AS THE ARCTIC BOUNDARY SINKS SOUTHWARD...TEMPS SHOULD FALL INTO THE TEENS IN MOST AREAS...EXCEPT FOR SINGLE DIGITS ACROSS PORTIONS OF THE ADIRONDACKS. ON SUNDAY...MAX TEMPS SHOULD GENERALLY ONLY REACH THE 20S IN VALLEYS WITH TEENS ACROSS THE ADIRONDACKS. TEMPS SHOULD THEN FALL INTO THE SINGLE DIGITS TO MID TEENS SUN NT...AND THEN ONLY RISE INTO THE TEENS AND 20S FOR MONDAY...ALTHOUGH THERE IS THE POTENTIAL FOR EVEN COLDER MAX TEMPS IF ENOUGH LOW LEVEL ARCTIC AIR SEEPS SOUTHWARD INTO THE REGION IN THE WAKE OF THE WEEKEND WAVE...AND IF SNOW FALLS INTO THIS COLD AND RELATIVELY DRY LOW LEVEL AIR. EXPECT SINGLE DIGITS AND TEENS AGAIN FOR MON NT/TUE AM...WITH TUE MAXES MAINLY IN THE 20S IN VALLEYS...AND TEENS ACROSS HIGHER ELEVATIONS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... WEAK LOW PRESSURE WILL TRACK ACROSS SOUTHEAST CANADA TODAY. A COLD FRONT TRAILING FROM THIS LOW WILL PASS THROUGH THE TAF SITES DURING THE MID TO LATE MORNING HOURS...PRECEDED AND ACCOMPANIED BY SNOW SHOWERS. SOME LAKE EFFECT SNOWBANDS COULD CONTINUE INTO EARLY THIS AFTERNOON...BEFORE HIGH PRESSURE BRINGS A PERIOD OF MAINLY CLEAR SKIES AND DIMINISHING WINDS TO THE TAF SITES FOR TONIGHT. THE AFOREMENTIONED COLD FRONT WILL APPROACH FROM THE WEST...AND PASS THROUGH THE TAF SITES BETWEEN ROUGHLY 14Z-17Z/WED. A BAND...OR PERHAPS MULTIPLE THIN BANDS OF SNOW SHOWERS SHOULD ACCOMPANY AND PRECEDE THIS FRONT. FOR NOW...HAVE INDICATED VCSH DURING THIS TIME PERIOD FOR MOST TAF SITES. HOWEVER...SHOULD ANY SNOW SHOWERS PASS THROUGH...BRIEF VSBY REDUCTIONS INTO MVFR/IFR WILL BE POSSIBLE. BEHIND THE FRONT...MAINLY VFR CONDITIONS ARE EXPECTED FOR THE AFTERNOON/EARLY EVENING. HOWEVER...WILL HAVE TO WATCH FOR ANY RESIDUAL LAKE ENHANCED/EFFECT SNOW SHOWERS OR SNOW BANDS...WHICH COULD IMPACT KGFL/KALB/KPSF INTO LATE AFTERNOON...AGAIN POSSIBLY PRODUCING BRIEF VSBY REDUCTIONS INTO MVFR/IFR. VFR CONDITIONS ARE EXPECTED FROM SUNSET...THROUGH 12Z/THU. WINDS WILL INCREASE FROM THE SOUTHWEST TO WEST AHEAD OF THE FRONT TO 8-12 KT BY MID MORNING...THEN SHIFT INTO THE WEST TO NORTHWEST BEHIND THE FRONT AND INCREASE TO 10-16 KT...WITH SOME GUSTS OF 25-30 KT POSSIBLE...ESP AT KALB AND KPSF WHERE WINDS COULD BE FURTHER ENHANCED DUE TO THE FUNNELING EFFECTS DOWN THE MOHAWK VALLEY. WINDS WILL GRADUALLY DECREASE FROM THE WEST/NORTHWEST TO 5-10 KT BY LATE EVENING...AND THEN BECOMING LIGHT/VARIABLE AFTER MIDNIGHT. OUTLOOK... THURSDAY NIGHT: LOW OPERATIONAL IMPACT.BREEZY SLIGHT CHANCE OF SHSN. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN...SN. && .HYDROLOGY... NO HYDRO IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS. AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW FROM CLIPPER LOWS OR LAKE EFFECT. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ032-038. MA...NONE. VT...NONE. && $$ SYNOPSIS...11/WASULA NEAR TERM...11/NAS/WASULA SHORT TERM...11 LONG TERM...KL AVIATION...KL HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
300 PM CST WED FEB 26 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 220 PM CST WED FEB 26 2014 MAIN FORECAST CONCERN IN THE SHORT TERM IS STRONG WINDS AND THE RESULTING BLOWING/DRIFTING SNOW EXPECTED ACROSS THE AREA THROUGH THIS EVENING. LATEST SURFACE ANALYSIS AND OBS SHOW THE COLD FRONT MOVING THROUGH THE NORTH HALF OF THE FORECAST AREA AT THE CURRENT TIME... WITH A NICE WIND SHIFT FROM SOUTHWEST TO NORTHWEST BEHIND THE FRONT. WE/RE SEEING STRONG SOUTHWEST WINDS... SUSTAINED NEAR 20KT WITH GUSTS TO AROUND 30KT AHEAD OF THE FRONT... AND NORTHWEST WINDS OF AROUND 25KT WITH GUSTS OF 35KT IMMEDIATELY BEHIND THE FRONT. HOWEVER... FORECAST SOUNDINGS FROM THE RAP AND NAM CONTINUE TO SUGGEST THE BEST MIXING WITH POST FRONTAL COLD ADVECTION AND SUBSIDENCE WILL OCCUR DURING THE EARLY EVENING ACROSS MOST OF THE AREA... WITH 00-05Z LOOKING LIKE PRIME TIME FOR STRONG WINDS AND POTENTIAL BLIZZARD CONDITIONS. THE HOPWRF MATCHES UP WITH THIS TIMING QUITE WELL... AND HAS ENSEMBLE MEAN SUSTAINED WINDS OF AROUND 30 MPH AND GUSTS WELL IN EXCESS OF 40 MPH FOR A PERIOD OF SEVERAL HOURS. LOCATIONS WHICH WILL SEE THE GREATEST IMPACT STILL LOOK TO BE THE OPEN AREAS OVER THE WESTERN AND SOUTHERN PART OF THE AREA... WHERE THE COMBINATION OF DEEP SNOW... STRONG WINDS... AND FAVORABLE TERRAIN SHOULD LEAD TO WIDESPREAD LOW VISIBILITY AND SIGNIFICANT DRIFTING SNOW. SOME LIGHT SNOW AND FLURRIES WILL SLIP THROUGH THE NORTH/NORTHEAST PORTION OF THE AREA THROUGH THIS EVENING... BUT ANY ACCUMULATION WILL BE VERY MINOR GIVEN THE EXTREMELY LIMITED MOISTURE AHEAD OF THE SHORTWAVE AND COLD FRONT. THE PRESSURE GRADIENT LOOKS TO QUICKLY RELAX OVERNIGHT INTO THURSDAY MORNING... SO WE SHOULD SEE THE BLOWING/DRIFTING SETTLE DOWN FAIRLY QUICKLY AFTER MIDNIGHT. WILL KEEP THE GOING HEADLINES IN PLACE... AS WELL AS THE TIMING... WHICH STILL LOOKS TO ENCAPSULATE THE ENTIRETY OF THE EVENT. HOWEVER... WIND CHILLS WILL BE PLUMMETING OVERNIGHT AS COLDER AIR ARRIVES. ALTHOUGH WINDS WILL BE DYING OFF... THEY WILL STILL BE SUFFICIENT TO PRODUCE VERY COLD WIND CHILLS... WHICH WILL PERSIST INTO THE DAY ON THURSDAY. THE NORTHERN COUNTIES LOOK LIKE THEY WILL SEE WIDESPREAD WIND CHILLS OF -35 TO -45... WHILE THE CENTRAL AND SOUTHERN PORTION OF THE AREA WILL MAINLY BE IN THE -25 TO -35 RANGE. SO... ALTHOUGH THE HEADLINES FOR BLOWING/DRIFTING SNOW WILL END OVERNIGHT... THEY WILL BE REPLACED BY WIND CHILL HEADLINES THROUGH THURSDAY MORNING. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 220 PM CST WED FEB 26 2014 LONGER TERM TRENDS CONTINUE TO REMAIN COLD. TEMPERATURES ARE EXPECTED TO REMAIN FAR BELOW NORMAL THROUGH THE ENTIRE PERIOD. STANDARDIZED ANOMALIES FROM THE NAM AND GEFS CONTINUE TO SHOW H85 TEMPERATURES AROUND 2 TO 3 STANDARD DEVIATIONS BELOW NORMAL...WHICH SHOULD CONTINUE TO YIELD 30 TO 40 DEGREES BELOW NORMAL THROUGH MOST OF THE PERIOD. SOME INDICATIONS AT THE END OF THE PERIOD...INTO NEXT WEEK...THE UPPER FLOW PATTERN MAY FLATTEN A BIT OVER THE NORTHERN CONUS...ALLOWING SOME MODIFIED PACIFIC TYPE AIR TO INTRUDE ACROSS THE NORTHERN PLAINS. THAT IS PRETTY FAR IN THE FUTURE AND THE 12Z ECMWF IS THE MODEL MOST PROMINENT WITH THIS OVERALL DEVELOPMENT. A COUPLE OF SNOW CHANCES COME INTO PLAY...NAMELY FRIDAY AND SATURDAY/SATURDAY NIGHT. MODELS TREND AN INVERTED TROUGH EAST ACROSS THE CWA ON FRIDAY. BEST FORCING IS FOUND OVER THE SOUTHERN CWA. WILL CONTINUE TO MENTION LIKELY POPS FOR THE SOUTHERN THIRD OF THE AREA THEN. WILL HAVE TO MONITOR FOR DEVELOPMENT ON THE NORTH END OF THE TROUGH AS WELL...BUT CONTINUE CHANCE POPS THERE. THIS WOULD GENERATE AN INCH OR TWO OF ACCUMULATION TO THE SOUTH BY FRIDAY EVENING. SHOULD BE A FLUFFY SNOW AND WINDS DO INCREASE SOME IN THE WAKE OF THE TROUGH. AT THE PRESENT TIME THEY DO NOT APPEAR TO BE STRONG ENOUGH TO GENERATE SIGNIFICANT BLOWING/DRIFTING SNOW CONCERNS. THE NEXT SNOW THREAT ARRIVES FOR SATURDAY AND SATURDAY NIGHT. MODELS IN SOME DISAGREEMENT AS TO HOW FAR AND SNOW THREAT WOULD BE AS LARGE COLD ARCTIC HIGH BUILDS SOUTHEAST OVER THE AREA INTO HE WEEKEND. AT THE MOMENT THE BEST AGREEMENT REMAINS OVER FAR SOUTHERN MINNESOTA FOR MEASURABLE SNOW AND WILL MENTION LIKELY POPS IN THAT AREA. WIND CHILL CONCERNS WILL CONTINUE INTO THE WEEKEND BUT WINDS SHOULD GRADUALLY DIMINISH AS THE ARCTIC HIGH SETTLES CLOSE TO THE CWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1118 AM CST WED FEB 26 2014 MAIN ISSUE OF CONCERN WILL BE STRONG WINDS AHEAD OF COLD FRONT THROUGH MID AFTERNOON... THEN BEHIND THE FRONT WITH THE STRONG COLD ADVECTION THROUGH THIS EVENING. BLOWING SNOW IS EXPECTED GIVEN THE EXPECTATION FOR WIND GUSTS AOA 35KT... BUT WE/RE STILL WAITING TO SEE HOW BAD THE BLOWING GETS SINCE MOST OF THE MORE RECENT SNOWFALL IS STILL DOWNSTREAM OF WHERE CURRENT HIGHER WINDS ARE OCCURRING. THERE ARE SOME SPOTTY MVFR CEILINGS NEAR THE FRONTAL BOUNDARY... BUT THOSE AND THE MAIN CHANCE FOR ANY LIGHT SNOW STILL LOOKS TO MAINLY IMPACT LOCATIONS NORTH/EAST OF THE FORECAST AREA. HOWEVER... CONTINUED TO MENTION AT LEAST SOME POSSIBILITY OF NEAR-MVFR CEILINGS FOR A BRIEF WINDOW OF TIME ACROSS THE NORTHEAST TAF SITES. OTHERWISE... STUCK VERY CLOSE TO THE PREVIOUS FORECAST... WHICH LOOKED TO HAVE A GOOD HANDLE ON THE TIMING OF THE STRONGEST WINDS AND A BEST GUESS OF WHAT VISIBILITIES WILL DO WITH THE BLOWING SNOW. SHOULD SEE THINGS QUICKLY IMPROVE OVERNIGHT... WITH LIGHT WINDS BY MORNING. KMSP...MAIN AREA OF UNCERTAINTY WITH THE TAF IS THE DEGREE OF VISIBILITY REDUCTION WHEN WINDS PICK UP LATER THIS AFTERNOON INTO THIS EVENING. STAYED SOMEWHAT OPTIMISTIC FOR NOW... BUT AMENDMENTS COULD CERTAINLY OCCUR IF WE START TO SEE VISIBILITIES SIGNIFICANTLY DROP IN UPSTREAM LOCATIONS. OTHERWISE... HAVE GOOD CONFIDENCE OVERALL IN THE TIMING OF WIND SHIFT/SPEEDS AND THE POTENTIAL WINDOW OF ANY NEAR-MVFR CEILINGS. /OUTLOOK FOR KMSP/ THURSDAY NIGHT...VFR. SOUTHEAST WIND 5 TO 15 KT. FRIDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF SNOW. SOUTHEAST WIND 5 TO 10 KT SHIFTING NORTHWEST. FRIDAY NIGHT...MVFR CEILINGS POSSIBLE. NORTHWEST WIND 5 TO 10 KT. SATURDAY AND SATURDAY NIGHT...VFR. NORTHWEST WIND 5 TO 15 KT DECREASING TO LESS THAN 5 KT. SUNDAY...VFR. NORTHWEST WIND 5 TO 15 KT. SUNDAY NIGHT...MVFR CEILINGS POSSIBLE. NORTHWEST WIND 10 TO 15 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR MNZ047- 048-054>070-073>078-082>085-091>093. BLIZZARD WARNING UNTIL 3 AM CST THURSDAY FOR MNZ066>069-074>077- 082>085-091>093. WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR MNZ041>045- 049>053. BLIZZARD WARNING UNTIL 3 AM CST THURSDAY FOR MNZ041-042-048-049- 055>059-065-073. WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ043>045- 047-050-051-054-064. WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ052-053- 060>063-070-078. WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR WIZ023>028. WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR WIZ014>016. WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ014>016- 023>028. && $$ SHORT TERM...TRH LONG TERM...DWE AVIATION...TRH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
243 PM EST WED FEB 26 2014 .SYNOPSIS... A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING 10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1222 PM EST WEDNESDAY...SNOW SQUALL ACTIVITY HAS MOSTLY ENDED ACROSS EASTERN VERMONT AND HAVE ADJUSTED POPS/WX GRIDS ACCORDINGLY. CLOUDS ARE VARIABLE ACROSS THE AREA WITH SOME BREAKS HERE AND THERE...ESPECIALLY IN THE CHAMPLAIN VALLEY. HAVE ADJUSTED SKY GRIDS TO ACCOUNT FOR THIS AS WELL. BRISK WESTERLY WINDS CONTINUE WITH COLDER THAN NORMAL MAX TEMPS. PREVIOUS DISCUSSIONS FOLLOW. SNOW SQUALL ACTIVITY CURRENTLY MOVING ACROSS THE NORTHERN CHAMPLAIN VALLEY. THINK THAT CURRENT FORECAST IS IN GOOD SHAPE SO DID NOT ALTER POPS OR WX AT ALL. THIS AREA OF SQUALLS WILL PUSH EASTWARD ACROSS VERMONT OVER THE NEXT FEW HOURS AND THEN POPS DECREASE LATE THIS AFTERNOON AND EVENING. PREVIOUS DISCUSSION FOLLOWS. SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE ONTARIO AND AS FRONTOGENESIS CIRCULATION HAS BEEN DISRUPTED BY THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF STEEP LOW- LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY NIGHT/... AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF NEXT SYSTEM. NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY 15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE. FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY 8-9F IN THE NRN ADIRONDACK REGION. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 243 PM EST WEDNESDAY...GOING INTO THE UPCOMING WEEKEND...HIGH PRESSURE OFF THE NEW ENGLAND COAST WITH SOUTHERLY FETCH STARTS OFF THE SATURDAY TIMEFRAME. LATEST GFS/ECMWF BOTH BRING LOW PRESSURE EASTWARD THRU NORTHERN PORTIONS OF THE GREAT LKS AND SLOWLY INTO SOUTHERN QUEBEC BY SATURDAY NIGHT. WITH APPROACH OF THIS SYSTEM...SFC RIDGE DOES SLIDE SOUTH OF THE AREA AND IN EFFECT SLOWS APPROACH OF TRAILING FRONTAL BOUNDARY UNTIL LATE SAT NGT. BULK OF PRECIP W/ FROPA TO OCCUR ON SUNDAY...WITH NOSING SFC RIDGE BEHIND FRONT COMBINED WITH ZONAL MID-LEVEL FLOW PUSHING FRONT OFFSHORE FOR SUNDAY NIGHT. RESPITE FROM PRECIP IS BRIEF THOUGH AS SECONDARY LOW ALONG FRONT LIFTS TOWARDS THE AREA. GFS/ECMWF SOLUTIONS DO DIFFER FROM HERE TO END OF FORECAST PERIOD... IN THAT GFS WANTS CUTOFF UPPER LOW OVER GREAT LKS TO KEEP CHANCE FOR PRECIP TO LINGER THRU MIDWEEK NEXT WEEK...WHILE THE ECMWF HAS ZONAL FLOW PUSH SECOND SYSTEM OFF TO OUR SOUTH WITH SFC HIGH PRESSURE BUILDING OVER AREA. WITH INCONSISTENCIES SHOWING WILL KEEP PRECIP OVER AREA FOR SECOND LOW WITH HIGHEST POPS SOUTH BASED ON TRACK...THEN SL CHANCE/CHANCE POPS FOR --SW IN REST OF TIME. WITH THE EXCEPTION OF WAA ON SOUTHERLY FLOW INITIALLY FOR SATURDAY...THE MAJORITY OF THE EXTEND PERIOD WILL HAVE BLW NORMAL TEMPS FOR BOTH HIGHS AND LOWS AS A COMBO OF SFC HIGHS AND UPPER LEVEL SUPPORT WILL KEEP REINFORCING CD AIR OVER THE REGION. OVERALL TEMPS LOOKING FOR A RANGE OF TEENS/L20S FOR HIGHS AND ZERO TO 10 BLW FOR OVERNGT PERIODS. AGAIN SAT/SAT NGT ARE THE OUTLIERS FOR TEMPS DUE TO WAA SATURDAY AND THE SLOW TRANSITION BACK TO COLDER AIRMASS DUE TO SLOW MVG FRONT SAT NGT. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...MAINLY VFR COND THRU FORECAST PERIOD W/ SCT025-040 BKN080 FOR BTV/MPV/PBG/RUT. MVFR -SW FOR RUT POSSIBLE THRU 00Z THURS W/ 3SM VSBY. AFT 15Z THURSDAY...MVFR COND DEVELOP WITH -SW AND CEILINGS NEAR BKN025. FOR MSS/SLK...MIX OF VFR DOWN TO IFR COND AT TIMES W/ BLSN THRU 00Z THURSDAY DROPPING VSBY TO 3-6SM AT TIMES...THEN -SW DEVELOPING FROM LK BAND AS WINDS SHIFTS W/ VSBY 2-5SM AND CEILINGS BKN020-040. WINDS OVERALL WSW 10-20KTS WITH GUSTS NEAT 30KTS THRU 00Z THURS THEN 10KTS OR LESS THRU 15Z THURSDAY THEN BECM SOUTHERLY AT 10-15KTS.. OUTLOOK 18Z THURSDAY THROUGH MONDAY... MAINLY VFR CONDITIONS BTWN 06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH ADDITIONAL LIGHT SNOW SHOWERS. VFR MONDAY W/ OCNL MVFR -SW. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS/NEILES SHORT TERM...BANACOS LONG TERM...JN AVIATION...JN/TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1238 PM EST WED FEB 26 2014 .SYNOPSIS... A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING 10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1222 PM EST WEDNESDAY...SNOW SQUALL ACTIVITY HAS MOSTLY ENDED ACROSS EASTERN VERMONT AND HAVE ADJUSTED POPS/WX GRIDS ACCORDINGLY. CLOUDS ARE VARIABLE ACROSS THE AREA WITH SOME BREAKS HERE AND THERE...ESPECIALLY IN THE CHAMPLAIN VALLEY. HAVE ADJUSTED SKY GRIDS TO ACCOUNT FOR THIS AS WELL. BRISK WESTERLY WINDS CONTINUE WITH COLDER THAN NORMAL MAX TEMPS. PREVIOUS DISCUSSIONS FOLLOW. SNOW SQUALL ACTIVITY CURRENTLY MOVING ACROSS THE NORTHERN CHAMPLAIN VALLEY. THINK THAT CURRENT FORECAST IS IN GOOD SHAPE SO DID NOT ALTER POPS OR WX AT ALL. THIS AREA OF SQUALLS WILL PUSH EASTWARD ACROSS VERMONT OVER THE NEXT FEW HOURS AND THEN POPS DECREASE LATE THIS AFTERNOON AND EVENING. PREVIOUS DISCUSSION FOLLOWS. SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE ONTARIO AND AS FRONTOGENESIS CIRCULATION HAS BEEN DISRUPTED BY THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF STEEP LOW- LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF NEXT SYSTEM. NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY 15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE. FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY 8-9F IN THE NRN ADIRONDACK REGION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY. TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS. MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED 5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...MAINLY VFR COND THRU FORECAST PERIOD W/ SCT025-040 BKN080 FOR BTV/MPV/PBG/RUT. MVFR -SW FOR RUT POSSIBLE THRU 00Z THURS W/ 3SM VSBY. AFT 15Z THURSDAY...MVFR COND DEVELOP WITH -SW AND CEILINGS NEAR BKN025. FOR MSS/SLK...MIX OF VFR DOWN TO IFR COND AT TIMES W/ BLSN THRU 00Z THURSDAY DROPPING VSBY TO 3-6SM AT TIMES...THEN -SW DEVELOPING FROM LK BAND AS WINDS SHIFTS W/ VSBY 2-5SM AND CEILINGS BKN020-040. WINDS OVERALL WSW 10-20KTS WITH GUSTS NEAT 30KTS THRU 00Z THURS THEN 10KTS OR LESS THRU 15Z THURSDAY THEN BECM SOUTHERLY AT 10-15KTS.. OUTLOOK 18Z THURSDAY THROUGH MONDAY... MAINLY VFR CONDITIONS BTWN 06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH ADDITIONAL LIGHT SNOW SHOWERS. VFR MONDAY W/ OCNL MVFR -SW. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS/NEILES SHORT TERM...BANACOS LONG TERM...TABER AVIATION...JN/TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1224 PM EST WED FEB 26 2014 .SYNOPSIS... A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING 10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1222 PM EST WEDNESDAY...SNOW SQUALL ACTIVITY HAS MOSTLY ENDED ACROSS EASTERN VERMONT AND HAVE ADJUSTED POPS/WX GRIDS ACCORDINGLY. CLOUDS ARE VARIABLE ACROSS THE AREA WITH SOME BREAKS HERE AND THERE...ESPECIALLY IN THE CHAMPLAIN VALLEY. HAVE ADJUSTED SKY GRIDS TO ACCOUNT FOR THIS AS WELL. BRISK WESTERLY WINDS CONTINUE WITH COLDER THAN NORMAL MAX TEMPS. PREVIOUS DISCUSSIONS FOLLOW. SNOW SQUALL ACTIVITY CURRENTLY MOVING ACROSS THE NORTHERN CHAMPLAIN VALLEY. THINK THAT CURRENT FORECAST IS IN GOOD SHAPE SO DID NOT ALTER POPS OR WX AT ALL. THIS AREA OF SQUALLS WILL PUSH EASTWARD ACROSS VERMONT OVER THE NEXT FEW HOURS AND THEN POPS DECREASE LATE THIS AFTERNOON AND EVENING. PREVIOUS DISCUSSION FOLLOWS. SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE ONTARIO AND AS FRONTOGENETIC CIRCULATION HAS BEEN DISRUPTED BY THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF STEEP LOW- LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF NEXT SYSTEM. NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY 15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE. FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY 8-9F IN THE NRN ADIRONDACK REGION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY. TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS. MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED 5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT ACRS THE SLV/WESTERN DACKS...WITH A NARROW BAND OF ENHANCED SNOW SHOWER ACTIVITY WITH VIS <1SM. LATEST HRRR/RAP DATA SHOWS THIS BAND ENTERING THE CPV BTWN 12-15Z THIS MORNING...BUT WEAKENING WITH SOUTHWEST DOWNSLOPE FLW AND INTERACTION OFF THE DACKS. A BRIEF 20 TO 30 MINUTE WINDOW OF MVFR CONDITIONS WITH VIS AROUND 3SM IN SNOW SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE WEST AT PBG/BTV. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL OCCUR AFT 14Z AT MPV/RUTLAND. IN ADDITION...THE COMBINATION OF UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 14Z THIS MORNING AT SLK. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15 KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY BTWN 14Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET THIS EVENING. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN 06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH ADDITIONAL LIGHT SNOW SHOWERS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS/NEILES SHORT TERM...BANACOS LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1243 PM EST WED FEB 26 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN JUST OFFSHORE THIS MORNING...BRINGING COLD RAIN TO THE AREA. DRY HIGH PRESSURE WILL BUILD IN FROM THE WEST TONIGHT...REINFORCED BY A SECOND HIGH BUILDING SOUTHWARD THURSDAY AND FRIDAY. THIS WILL MAINTAIN BELOW NORMAL TEMPERATURES. LOW PRESSURE OFFSHORE MAY BRING CLOUDS AND RAIN FRIDAY NIGHT THROUGH SATURDAY. WARMER TEMPERATURES ARE EXPECTED EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 12:30 PM WEDNESDAY...LIGHT RAIN AND DRIZZLE CONTINUES TO MOVE ACROSS THE BULK OF OUR FORECAST AREA ALTHOUGH IT LOOKS LIKE SOME RELIEF IS IN SIGHT FOR OUR FAR INLAND COUNTIES AS THE BACK EDGE OF THE PRECIP SHIELD IS NOW IN EVIDENCE. DO NOT EXPECT ANY MAJOR CHANGES IN THE FORECAST WITH THE AFTERNOON PACKAGE. PREVIOUS DISCUSSION FOLLOWS: RAIN IS EXPANDING ACROSS SOUTH CAROLINA THIS MORNING AHEAD OF A PAIR OF SHORTWAVES. ONE DISTURBANCE IN THE SOUTHERN STREAM NEAR MOBILE AL WILL CROSS NORTH FLORIDA TODAY... WHILE A POSITIVELY- TILED SHORTWAVE IN THE NORTHERN STREAM FLOW ACROSS MISSOURI WILL MOVE ACROSS NC/VA THIS EVENING. AT THE SURFACE A COLD FRONT SLID SOUTH ACROSS THE AREA YESTERDAY EVENING...AND A SECOND SURGE OF NORTHERLY WINDS SHOULD OCCUR LATE THIS MORNING AS LOW PRESSURE DEVELOPS SOUTHEAST OF CAPE FEAR AND DEEPENS AS IT MOVES EAST AND FARTHER OFFSHORE. RAIN FALLING ACROSS AL/GA/SC THIS MORNING IS HEADING OUR WAY. ISENTROPIC LIFT ALONG THE 300-305K THETA SURFACES...APPROXIMATELY 9000-15000 FT ALOFT...APPEARS TO MATCH BEST WITH OBSERVED UPSTREAM RADAR ECHOES. TRACKING THIS EASTWARD THROUGH THE DAY BRINGS RAIN INTO THE AREA BETWEEN 8-9 AM...PEAKING IN COVERAGE AND INTENSITY AROUND NOON...THEN DIMINISHING FROM NW TO SE DURING THE AFTERNOON. THE NORTHERN EDGE OF MEASURABLE RAIN COULD BE VERY CLOSE TO BENNETTSVILLE...LUMBERTON AND ELIZABETHTOWN...AND I THEREFORE ONLY HAVE A FEW HUNDREDTHS OF AN INCH OF RAINFALL FORECAST FOR THESE LOCATIONS. THE BEST RAINFALL IN MY FORECAST AREA SHOULD BE ALONG THE SANTEE RIVER IN SOUTH CAROLINA WITH ABOUT THREE-TENTHS EXPECTED. SKIES MAY BEGIN TO CLEAR ALONG I-95 DURING THE AFTERNOON AS DRIER AIR WORKS ITS WAY IN ALOFT. LOW-LEVEL DRY AIR STREAMING SOUTHWARD BEHIND THE SURFACE COLD FRONT IS PROBABLY NOT DEEP ENOUGH TO AFFECT RAINFALL TOTALS BY ITSELF... BUT AS RAIN FALLS INTO THIS DRY AIR EVAPORATIONAL COOLING SHOULD CAUSE A FALLING TREND IN TEMPERATURES DURING THE LATE MORNING. LOOK FOR NON-TYPICAL TEMPERATURE CURVES AS A RESULT...PROBABLY SHAPED LIKE A "U" DURING THE DAYLIGHT HOURS TODAY. FOR TONIGHT MOISTURE SHOULD THIN FROM THE TOP DOWN WITH SKIES CLEARING ALONG THE COAST. LIGHT WINDS OVERNIGHT AND A FAIRLY CHILLY AIRMASS (850 MB TEMPS FALLING TO ZERO TO -4C) SHOULD ALLOW LOWS TO REACH THE UPPER 20S FOR ALL BUT THE BEACHES. THE MODELS ARE HINTING AT SOME THIN LOW LEVEL MOISTURE LINGERING ALONG THE COAST WHICH COULD RESULT IN SOME OVERNIGHT FOG...PARTICULARLY IF WINDS BECOME CALM. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 330 AM WEDNESDAY...AMPLIFIED MID TO UPPER LONGWAVE TROF ACROSS THE FA ON THU...WILL DE-AMPLIFY SOME FRIDAY INTO FRIDAY NIGHT. A RE-ENFORCING SHOT OF ARCTIC AND DRIER AIR FROM THE NW THRU N...WILL PUSH ACROSS THE FA LATE THU AND/OR THU NIGHT. VERY LITTLE CLOUDS AND NO PCPN WILL ACCOMPANY THIS CFP. WINTER TO REMAIN ACTIVE WITH RESPECT TO THE COLD TEMPERATURES. HAVE STAYED AT OR JUST ABOVE THE GFS TEMP MOS GUIDANCE...WHICH PRODUCES MIN/MAX TEMPS LATE THU THROUGH MUCH OF FRI AT 10 TO POSSIBLY 15 DEGREES BELOW THE CLIMO NORMALS. THE DRIER AIR THAT WORKS ACROSS THE FA THU AFTN AND AGAIN ON FRI...COULD BECOME A FIRE HAZARD ESPECIALLY WITH SFC RHS FORECAST TO DROP TO AROUND 25 PERCENT EACH AFTN. A LIGHT ONSHORE FLOW DURING FRIDAY MAY HELP KEEP THE COASTAL COUNTIES SLIGHTLY HIGHER IN THE RH DEPARTMENT. WILL NEED TO MONITOR. THE MID TO UPPER FLOW BEGINS TO -AMPLIFY SOME FRI NIGHT WITH THE SOUTHERN STREAM BECOMING A BIT MORE ACTIVE ACROSS THE FORECAST AREA. TEMPS FRIDAY NITE/SAT MORNING WILL NOT BE AS COLD AS THU NIGHT/FRI MORNING. AN INVERTED SFC TROF JUST OFF THE CAROLINA COAST BY SAT MORNING COULD PUSH LOW CLOUDS ONSHORE BY DAYBREAK SAT. A VERY LOW CHANCE WILL EXIST FOR PATCHY LIGHT RAIN DURING THE PRE-DAWN SAT HRS. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 345 AM WEDNESDAY...THE MID TO UPPER LONGWAVE TROF ACROSS THE FA WILL CONTINUE TO DE-AMPLIFY THRU THE UPCOMING WEEKEND. THE SOUTHERN STREAM MID TO UPPER FLOW BECOMES MORE ACTIVE THIS WEEKEND...WITH UPPER RIDGING LIKELY TO EXTEND ACROSS THE FA FROM THE GULF OF MEXICO. THIS WILL TEMPORARILY PREVENT POLAR/ARCTIC AIR WITHIN THE NORTHERN STREAM FROM PUSHING TO THE SOUTHEAST STATES...INCLUDING THE ILM CWA...DURING THIS WEEKEND. SOME WEAK FORCING SAT COULD PRODUCE PATCHY LIGHT RAIN ACROSS THE FA AS THE DYNAMICS FROM A MID TO UPPER S/W TROF CLIPPER TYPE SYSTEM REMAINS WELL NORTH OF THE FA. DURING SAT...THE COASTAL TROF/FRONT OVER THE ADJACENT ATL WATERS GETS PULLED TO THE NW-N AND INLAND...ACTING SIMILAR TO A WARM FRONTAL PASSAGE. TEMPS WILL REBOUND THIS WEEKEND AND CLIMB TO JUST BELOW NORMAL ON SAT...AND AT OR SLIGHTLY ABOVE NORMAL ON SUN. FOR MON INTO TUE...MODELS ARE QUITE DISSIMILAR WITH ONE ANOTHER WITH RESPECT TO THE UPPER LONGWAVE PATTERN AS WELL AS THE UPPER SHORT WAVE PATTERN THAT HELPS DEFINE/CONSTRUCT THIS LONGWAVE PATTERN. AS A RESULT...HAVE STAYED CLOSER TO THE PREVIOUS FORECAST. HAVE TWEAKED TEMPS SLIGHTLY UPWARD MONDAY AS LOW LEVEL FLOW FROM THE SOUTH CONTINUES TO PUMP MILD AIR AND HIGHER DEWPOINTS. WILL HAVE TO KEEP AN EYE ON TUE INTO WED AS A COLD FRONT DROPS SOUTHWARD WHILE A MID TO UPPER LEVEL SOUTHERN STREAM S/W TROF APPROACHES FROM THE WSW. WILL CONTINUE TO INDICATE CHANCE POPS...WITH ABOVE FREEZING LIQUID RAIN RULING THE PCPN TYPE. && .AVIATION /18Z WEDNESDAY THROUGH SUNDAY/... AS OF 18Z...LIGHT TO MODERATE STRATIFORM RAIN CONTINUES TO MOVE ACROSS OUR CWA THIS AFTERNOON...WITH THE HEAVIEST/MOST PERSISTENT RAIN OVER OUR SOUTHERN COUNTIES. THEREFORE...CIGS RANGE FROM VFR AT KLBT TO MVFR/TEMPO IFR AT KCRE/KMYR. EXPECT MVFR CIGS TO PREVAIL AT ALL SITES EXCEPT PERHAPS KLBT THIS AFTERNOON. RADAR TRENDS AND HRRR RUNS INDICATE MOST OF THE PCPN AFTER 18Z WILL BE FOCUSED ALONG THE COAST...SO WILL MAINTAIN LOWER MVFR CIGS AT THESE SITES WITH TEMPO IFR AT KCRE AND KMYR. THE WINDS WILL REMAIN NORTH 6-10 KTS INTO THE EVENING HOURS AS PCPN TAPERS OFF AND VFR DEVELOPS FROM WEST TO EAST. FCST SOUNDINGS SHOW ENOUGH RESIDUAL MOISTURE OVERNIGHT TO WARRANT A MENTION OF PATCHY FOG...SO HAVE ADDED TEMPO MVFR VSBYS FOR ALL SITES BEFORE DAYBREAK. THURSDAY WILL BE VFR WITH NORTHWEST WINDS AOB 8 KTS. EXTENDED OUTLOOK...VFR ON FRIDAY. CHANCE OF RAIN/MVFR ON SATURDAY. MVFR/IFR CIGS/VSBYS POSSIBLE ON SUNDAY. VFR ON MONDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 12:30 PM WEDNESDAY...HAVE DROPPED THE SMALL CRAFT ADVISORY FORMERLY IN EFFECT FOR OUR NC WATERS IN FAVOR OF SCEC HEADLINES. WINDS HAVE STAYED MAINLY IN THE 15 KT RANGE WITH 2 TO 4 FT SEAS SO FAR. HOWEVER...A SURGE OF WIND THIS AFTERNOON MAY PUSH SEAS UP INTO THE 3 TO 5 FT RANGE THROUGH THE EVENING HOURS. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 345 AM WEDNESDAY...THURSDAY WILL FEATURE A REINFORCING SHOT OF POLAR/ARCTIC AIR FROM HIGH PRESSURE THAT WILL FOLLOW AFTER THE PASSAGE OF THE FRONT THU AFTN OR EARLY EVENING. SCEC OR EVEN SCA CONDITIONS WILL MAKE AN APPEARANCE AFTER THE COLD FRONTAL PASSAGE...AND COULD LAST THROUGH MUCH OF FRIDAY AS THE SFC PG TO REMAIN TIGHTENED ACROSS THE WATERS AS RIDGING FROM THE 1030+ HIGH CENTERED OVER THE NE STATES FLEXES ITS MUSCLE. SIGNIFICANT SEAS WILL BUILD RATHER QUICKLY THU NIGHT THRU FRIDAY...WITH NE-E LOCALLY PRODUCED WIND DRIVEN SHORT PERIOD WAVES DOMINATING THE SEAS SPECTRUM. WILL HIGHLIGHT THE SCEC/SCA POSSIBILITY IN THE HWO. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 415 AM WEDNESDAY...COASTAL TROF/FRONT WILL DEVELOP OFF THE CAROLINA COAST SATURDAY...AND LIFT AND/OR SWEEP ACROSS THE AREA WATERS AND INLAND DURING SAT INTO EARLY SUN. BY SUNDAY...FLOW ACROSS THE WATERS WILL HAVE VEERED TO THE SE-SSW. THIS A RESULT OF SFC HIGH PRESSURE TEMPORARILY CENTERED OFFSHORE FROM THE SE U.S. COAST...AND HAVING BECOME THE PRIMARY DRIVER FOR WINDS ACROSS THE AREA WATERS. THE ONSHORE FLOW WILL HELP KEEP SIGNIFICANT SEAS SOMEWHAT ELEVATED BUT LIKELY REMAINING JUST BELOW SCEC/SCA THRESHOLDS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DCH NEAR TERM...REK/TRA SHORT TERM...DCH LONG TERM...DCH AVIATION...BJR MARINE...DCH/REK/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
113 PM CST WED FEB 26 2014 .UPDATE... ISSUED AT 110 PM CST WED FEB 26 2014 HAVE EXTENDED THE WIND ADVISORY INTO THE EVENING. WILL EXPECT A QUICK DROP IN SPEEDS AROUND 7 PM CST...EVEN A BIT BEFORE THAT IN THE NORTHWEST...WILLISTON AREA. WILL NEED TO POST ANOTHER WIND CHILL ADVISORY FOR TONIGHT INTO THURSDAY MORNING. AM WORKING OUT APPARENT TEMPERATURES NOW TO SEE WHAT AREAS CAN BE LEFT OUT OF IT. UPDATE ISSUED AT 1121 AM CST WED FEB 26 2014 WIND SPEEDS WERE RUNNING OVER FORECAST AND I DO NOT SEE WHY THEY WOULD DROP MUCH THE REST OF THE AFTERNOON. HAVE DECIDED TO EXPAND THE WIND ADVISORY A COUNTY OR TWO TO THE WEST OF WHAT IT WAS. THIS WILL NOW PLACE MOHALL...MINOT...GARRISON...STEELE...AND WISHEK IN THE ADVISORY. UPDATE ISSUED AT 1035 AM CST WED FEB 26 2014 HAVE UPDATED TO REMOVE THE WIND CHILL ADVISORY. BASED ON SURFACE OBSERVATION REPORTS AND NORTH DAKOTA DEPARTMENT OF TRANSPORTATION WEB CAMS...HAVE DECREASED THE PATCHY BLOWING SNOW FROM THE WEST AND DECREASED THE AREAS OF BLOWING SNOW IN THE EAST. SOME OF THE CAMERA IMAGES LOOK MILKY BUT NOTHING DECREASING VISIBILITY TO ANYTHING HAVING AN IMPACT. ROLLA...ROLETTE COUNTY...WAS REPORTING REDUCED VISIBILITY...ON INTO THE DEVILS LAKE BASIN. HAVE ALSO DECREASED CLOUD COVER TODAY WEST INTO CENTRAL. WILL NEED ANOTHER WIND CHILL ADVISORY FOR WEDNESDAY NIGHT INTO THURSDAY MORNING. UPDATE ISSUED AT 637 AM CST WED FEB 26 2014 THE ONGOING WIND CHILL ADVISORY STILL LOOKS GOOD FOR THIS UPDATE. IN ADDITION...INCREASING ISALLOBARIC WINDS STILL LOOK TO GENERATE WINDS MEETING WIND ADVISORY CRITERIA EAST THIS AFTERNOON. AS A RESULT...WILL LEAVE THE CURRENT HEADLINES AS IS FOR THIS UPDATE. OTHERWISE...THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST WED FEB 26 2014 THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID MORNING INTO THE AFTERNOON. EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES. FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35 BELOW. WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES. WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO 1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY. IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER. WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS WILL HAVE TO CONSIDER THAT POSSIBILITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 26 2014 WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND. SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM RANGE MODELS MAINTAIN A DRY FROPA. WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT. THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY. THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 110 PM CST WED FEB 26 2014 STRONG NORTHWEST WINDS ARE FORECAST UNTIL 01Z/27TH...AFTER WHICH TIME THEY WILL BE RAPIDLY DECREASING. STRONGEST WINDS WILL OCCUR FROM KMOT TO KJMS WHERE PATCHY BLOWING SNOW IS POSSIBLE BUT WITH NO SIGNIFICANT REDUCTION IN VISIBILITY. VFR CIGS AND VSBYS WILL CONTINUE THROUGH THE TAF VALID PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 7 PM CST THIS EVENING FOR NDZ002>005-011>013- 021>023-025-036-037-047-048-050-051. && $$ UPDATE...JPM SHORT TERM...CK LONG TERM...TM AVIATION...JPM/ACOOP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1124 AM CST WED FEB 26 2014 .UPDATE... ISSUED AT 1121 AM CST WED FEB 26 2014 WIND SPEEDS WERE RUNNING OVER FORECAST AND I DO NOT SEE WHY THEY WOULD DROP MUCH THE REST OF THE AFTERNOON. HAVE DECIDED TO EXPAND THE WIND ADVISORY A COUNTY OR TWO TO THE WEST OF WHAT IT WAS. THIS WILL NOW PLACE MOHALL...MINOT...GARRISON...STEELE...AND WISHEK IN THE ADVISORY. UPDATE ISSUED AT 1035 AM CST WED FEB 26 2014 HAVE UPDATED TO REMOVE THE WIND CHILL ADVISORY. BASED ON SURFACE OBSERVATION REPORTS AND NORTH DAKOTA DEPARTMENT OF TRANSPORTATION WEB CAMS...HAVE DECREASED THE PATCHY BLOWING SNOW FROM THE WEST AND DECREASED THE AREAS OF BLOWING SNOW IN THE EAST. SOME OF THE CAMERA IMAGES LOOK MILKY BUT NOTHING DECREASING VISIBILITY TO ANYTHING HAVING AN IMPACT. ROLLA...ROLETTE COUNTY...WAS REPORTING REDUCED VISIBILITY...ON INTO THE DEVILS LAKE BASIN. HAVE ALSO DECREASED CLOUD COVER TODAY WEST INTO CENTRAL. WILL NEED ANOTHER WIND CHILL ADVISORY FOR WEDNESDAY NIGHT INTO THURSDAY MORNING. UPDATE ISSUED AT 637 AM CST WED FEB 26 2014 THE ONGOING WIND CHILL ADVISORY STILL LOOKS GOOD FOR THIS UPDATE. IN ADDITION...INCREASING ISALLOBARIC WINDS STILL LOOK TO GENERATE WINDS MEETING WIND ADVISORY CRITERIA EAST THIS AFTERNOON. AS A RESULT...WILL LEAVE THE CURRENT HEADLINES AS IS FOR THIS UPDATE. OTHERWISE...THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST WED FEB 26 2014 THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID MORNING INTO THE AFTERNOON. EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES. FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35 BELOW. WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES. WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO 1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY. IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER. WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS WILL HAVE TO CONSIDER THAT POSSIBILITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 26 2014 WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND. SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM RANGE MODELS MAINTAIN A DRY FROPA. WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT. THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY. THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1035 AM CST WED FEB 26 2014 VFR AT ALL TAF SITES THROUGH THE FORECAST VALID PERIOD UNDER A MOSTLY CLEAR SKY. THE MAIN CONCERN THROUGH 02Z/27TH IS GUSTY NORTHWEST WINDS...ESPECIALLY OVER THE EASTERN HALF OF NORTH DAKOTA. SPEEDS WILL BE AROUND 25 KNOTS...GUSTING 35 KNOTS. THIS WILL CREATE PATCHES OF BLOWING SNOW. NOTE THAT KMOT HAS BEEN REPORTING -SN BUT THAT IS NOT FALLING SNOW...IT IS SNOW BEING BLOWN INTO THE ASOS SENSOR. VSBY AT KMOT WAS STILL P6SM. SIMILAR THING COULD HAPPEN AT KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ002>005-011>013- 021>023-025-036-037-047-048-050-051. && $$ UPDATE...JPM SHORT TERM...CK LONG TERM...TM AVIATION...JPM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1043 AM CST WED FEB 26 2014 .UPDATE... ISSUED AT 1035 AM CST WED FEB 26 2014 HAVE UPDATED TO REMOVE THE WIND CHILL ADVISORY. BASED ON SURFACE OBSERVATION REPORTS AND NORTH DAKOTA DEPARTMENT OF TRANSPORTATION WEB CAMS...HAVE DECREASED THE PATCHY BLOWING SNOW FROM THE WEST AND DECREASED THE AREAS OF BLOWING SNOW IN THE EAST. SOME OF THE CAMERA IMAGES LOOK MILKY BUT NOTHING DECREASING VISIBILITY TO ANYTHING HAVING AN IMPACT. ROLLA...ROLETTE COUNTY...WAS REPORTING REDUCED VISIBILITY...ON INTO THE DEVILS LAKE BASIN. HAVE ALSO DECREASED CLOUD COVER TODAY WEST INTO CENTRAL. WILL NEED ANOTHER WIND CHILL ADVISORY FOR WEDNESDAY NIGHT INTO THURSDAY MORNING. UPDATE ISSUED AT 637 AM CST WED FEB 26 2014 THE ONGOING WIND CHILL ADVISORY STILL LOOKS GOOD FOR THIS UPDATE. IN ADDITION...INCREASING ISALLOBARIC WINDS STILL LOOK TO GENERATE WINDS MEETING WIND ADVISORY CRITERIA EAST THIS AFTERNOON. AS A RESULT...WILL LEAVE THE CURRENT HEADLINES AS IS FOR THIS UPDATE. OTHERWISE...THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST WED FEB 26 2014 THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID MORNING INTO THE AFTERNOON. EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES. FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35 BELOW. WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES. WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO 1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY. IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER. WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS WILL HAVE TO CONSIDER THAT POSSIBILITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 26 2014 WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND. SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM RANGE MODELS MAINTAIN A DRY FROPA. WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT. THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY. THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1035 AM CST WED FEB 26 2014 VFR AT ALL TAF SITES THROUGH THE FORECAST VALID PERIOD UNDER A MOSTLY CLEAR SKY. THE MAIN CONCERN THROUGH 02Z/27TH IS GUSTY NORTHWEST WINDS...ESPECIALLY OVER THE EASTERN HALF OF NORTH DAKOTA. SPEEDS WILL BE AROUND 25 KNOTS...GUSTING 35 KNOTS. THIS WILL CREATE PATCHES OF BLOWING SNOW. NOTE THAT KMOT HAS BEEN REPORTING -SN BUT THAT IS NOT FALLING SNOW...IT IS SNOW BEING BLOWN INTO THE ASOS SENSOR. VSBY AT KMOT WAS STILL P6SM. SIMILAR THING COULD HAPPEN AT KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ004-005-012-013- 022-023-025-037-048-051. && $$ UPDATE...JPM SHORT TERM...CK LONG TERM...TM AVIATION...JPM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1256 PM EST WED FEB 26 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION THIS MORNING AND USHER IN COOLER CANADIAN HIGH PRESSURE. THIS HIGH WILL BECOME REINFORCED FROM THE NORTH ON FRIDAY AND LINGER INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM EST WEDNESDAY...FORECAST REMAINS ON TRACK AS SHOWER ACTIVITY CONTINUES TO EXIT TO THE SOUTHEAST. THUS...ASIDE FROM ADJUSTING TEMPERATURES AND DEWPOINTS TO REFLECT LATEST OBSERVATIONAL TRENDS...NO OTHER CHANGES WERE MADE WITH THIS UPDATE. LOW RH AND INCREASING WINDS CONTINUE TO PRESENT MODEST FIRE WX CONCERNS TOMORROW...ESPECIALLY IN THE HIGH TERRAIN OF NC. PLEASE REFER TO FIRE WX SECTION OF AFD FOR DETAILS. PREVIOUS DISCUSSION... AS OF 615 AM EST...SHORTWAVE ROTATES THRU THE ERN CONUS UPPER TROUGH THIS MORNING...WITH COLD FRONT USHERING IN HIGH PRESSURE AND A MUCH COLDER AIRMASS OVER THE COURSE OF THE DAY. WESTERLY MIDLEVEL WINDS PRIOR TO THE FRONT WILL PROVIDE SLIGHT WARM ADVECTION AND ASSOCIATED LIFT...BUT MODELS SEEM TO RESPOND MORE TO INTERACTION OF FRONTAL CONVERGENCE WITH INCUMBENT MOISTURE ACRS GA/SC. MESO MODELS INCLUDING LATEST COUPLE HRRR RUNS CONFINE QPF RESPONSE WELL SOUTH OF I-85. GFS AND SREF HOWEVER FAVOR MORE OF THE PRECIP DEVELOPING ACRS THE UPSTATE. THIS IS NOT WELL SUPPORTED BY RADAR TRENDS SO FAR THIS AM. BEST POPS STILL LOOK TO BE IN 12-15Z TIMEFRAME AS THE FRONT ENTERS THE LOWER PIEDMONT. DESPITE LACK OF MODEL RESPONSE...GIVEN THE SETUP IT IS REASONABLE TO INCLUDE SCHC POPS A BIT FURTHER NORTH...WITH TIGHT THERMAL GRADIENT ACRS THE FA IN EXIT REGION OF THE SHORTWAVE THRU THE MRNG. NW FLOW STILL LOOKS TO HAVE SUFFICIENT ORIENTATION AND MOISTURE TO PRODUCE BRIEF LIGHT SNOW IN THE MTNS...BUT LATEST GUIDANCE SUPPORTS ONLY CHC POPS AND MINIMAL ACCUMS. IN FACT THIS MAY BE A BIT OPTIMISTIC GIVEN LACK OF RADAR RETURNS OVER EAST TN. CLEARING OF THE LOW-MID CLOUDS ASSOCIATED WITH THE FRONTAL ZONE IS EXPECTED TO RAPIDLY OCCUR THRU MIDDAY LEAVING A MOSTLY SUNNY AFTN. GIVEN THE COLD AND NEWLY ARRIVED AIR MASS BUT ALSO ABUNDANT SUNSHINE AND SLIGHT DOWNSLOPING...A BLEND OF MOS AND RAW TEMPS IS APPROPRIATE WHICH CONTINUES TO SUPPORT TEMPS A COUPLE CATEGORIES BELOW NORMAL EXCEPT IN THE HIGH TERRAIN WHERE MANY AREAS WON/T RISE OUT OF THE 30S. TONIGHT...WINDS BECOME LIGHT AND SKIES REMAIN CLEAR AND LOWS DROP INTO THE TEENS MTNS AND 20S PIEDMONT. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... AS OF 200 AM WEDNESDAY...A DRY COLD FRONT WILL CROSS THE REGION DURING THE DAY ON THURSDAY...LOWERING DEWPOINTS EVEN FURTHER. WITH BREEZY TO WINDY CONDITIONS OVER THE NC MTNS AND FOOTHILLS...THE POTENTIAL EXITS FOR CRITICAL FIRE WEATHER CONDITIONS. PLEASE SEE THE FIRE WEATHER PART OF THE DISCUSSION FOR MORE DETAILS. OTHERWISE...DRY COLD AIR DAMMING WILL BECOME MORE PRONOUNCED OVER THE REGION THURSDAY NIGHT AND FRIDAY. THE THICKNESS TROUGH IN THE LEE SHOULD RESULT IN COLD CONDITIONS THU NIGHT AND WELL BELOW NORMAL TEMPERATURES ON FRIDAY. THURSDAY WE SHOULD SEE CLEAR...BLUE SKIES. SKIES REMAIN CLEAR THU NIGHT...BUT HIGH CLOUDS SHOULD BE ON THE INCREASE DURING THE DAY ON FRIDAY. A FAST MOVING SHORT WAVE WILL CROSS THE NC ZONES FRI NIGHT. MOST OF THE FORCING WITH THE WAVE PASSES NORTH OF THE FORECAST AREA. HOWEVER...LLVL WARM ADVECTION OVER THE WRN PIEDMONT MAY SUPPORT SOME PATCHY LIGHT PCPN OVER THE ERN ZONES. THERE ALSO APPEARS TO BE SUFFICIENT FORCING ACROSS THE MTNS TO SUPPORT CHANCE POPS AS WELL. I USED THE BOURGOUIN TECHNIQUE WHICH STARTS PCPN AS RAIN EARLY FRIDAY NIGHT WITH A TRANSITION TO SNOW AND THEN FREEZING RAIN OVER MOST OF THE NC ZONES. UNDERSTAND THAT QPF IS VERY LIGHT WITH THIS EVENT AND POPS ARE GENERALLY IN THE LOW CHANCE TO SLIGHT CHANCE RANGE. THAT/S TO SAY...THE WEATHER GRID LOOKS SCARIER THAN THE REALITY OF THE SITUATION. STILL...WE COULD SEE A LIGHT ACCUMULATION OF SNOW OR ICE NORTH OF I40 AND OVER PARTS OF THE NC MTNS FRIDAY NIGHT...BUT THE PCPN IS SO LIGHT I DON/T EVEN PLAN TO MENTION IT IN THE HWO ATTM. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... AS OF 230 AM EST WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SUNDAY WITH WHATS LEFT OF AN UPPER SHORTWAVE MOVING OUT OVER THE ATLANTIC AND UPPER RIDGING BUILDING OVER THE GULF OF MEXICO AND SE CONUS. THE LONG RANGE MODELS ARE TRYING TO CLOSE OFF AN H5 LOW OVER EXTREME SOUTHERN BRITISH COLUMBIA EARLY SUNDAY WITH THE NEWER RUN OF THE GFS BEING MORE PRONOUNCED. AS WE MOVE INTO MONDAY...HEIGHTS BEGIN TO LOWER AGAIN AS A COMPLEX UPPER TROF PATTERN MOVES SE ACROSS THE FAR NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THE MODELS INDICATE THAT THE MAIN TROF AXIS WILL LIKELY BE NORTH OF THE CAROLINAS BY LATE TUES/EARLY WED AND PERSIST OVER THE REGION THRU DAY 7. OVERALL...THE LONG RANGE MODELS APPEAR TO BE COMING INTO BETTER AGREEMENT WRT THE PROGRESSION AND TIMING OF THIS UPPER TROF SYSTEM...WITH THE GFS BEING MORE AMPLIFIED AND BRINGING THE SYSTEM FARTHER SOUTH COMPARED TO THE ECMWF. AT THE SFC...THE HIGH CENTERED OVER NEW ENGLAND HELPING TO PRODUCE A COLD AIR WEDGE PATTERN OVER THE CAROLINAS WILL BE MOVING WELL OFF THE COAST BY EARLY SUN. THE MODELS CONTINUE TO MAINTAIN ANOTHER BERMUDA TYPE HIGH CENTERED TO OUR EAST ON SUN AND EARLY MON. THEY ALSO SPIN UP A LOW OVER THE SOUTHERN MISS RIVER VALLEY EARLY MON AND MOVE IT OVER THE CWFA BY MON AFTERNOON. WHAT HAPPENS OVER THE NEXT 24 TO 36HRS VARIES CONSIDERABLY BETWEEN THE GFS AND ECMWF. THE GFS KEEPS THE LOW AND ITS ASSOCIATED REGION OF BROAD AND DEEP MOISTURE OVER THE FCST AREA THRU TUES AFTERNOON BEFORE MOVING IT NE AND OFFSHORE...WHILE THE ECMWF AND CMC MOVE IT OFFSHORE BY MON EVENING WITH DRIER HIGH PRESSURE SPREADING OVER THE REGION IN ITS WAKE ON TUES. BOTH MODELS AGREE THAT THE REMAINDER OF THE FCST SHOULD BE DRY HIGH PRESSURE OVER THE AREA ON WED. TEMPS WILL START OUT WELL ABOVE NORMAL FOR EARLY MARCH WITH HIGHS ON SUN IN THE MID 60S FOR THE LOWER ELEVATIONS AND UPPER 50S TO LOW 60S FOR THE HIGHER TERRAIN. BY THE END OF THE PERIOD...I ANTICIPATE THAT VALUES WILL COOL BACK DOWN BELOW CLIMATOLOGY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD AS COLD AIR ADVECTION PREVAILS AND HIGH PRESSURE BUILDS. BKN MID/HIGH LEVEL CIRRUS WILL PERSIST THROUGH THE AFTERNOON AMIDST NE WINDS AROUND 6-8KTS. A SECOND MID LEVEL WAVE WILL DIVE ACROSS THE REGION OVERNIGHT LEADING DEVELOPMENT OF A WEAK LOW LEVEL TROF. INCREASING SATURATION ALONG THIS BOUNDARY WILL LEAD TO DEVELOPMENT OF LOW VFR CIGS THROUGH APPROXIMATELY 08Z BEFORE SCATTERING OUT. SKIES WILL CLEAR BY MID/LATE MORNING LEADING TO FAIR WEATHER FOR THURSDAY. AS FOR WINDS...EXPECTING FLOW TO BACK NORTHWESTERLY AS THE ABOVE MENTIONED WAVE AND ASSOCIATED WEAK SURFACE BOUNDARY PASS THROUGH THE REGION BY AROUND 15Z THURSDAY MORNING. ELSEWHERE...MUCH THE SAME AS KCLT ABOVE AS VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. BKN MID/HIGH LEVEL CIRRUS WILL PERSIST THROUGH THE AFTERNOON AT ALL SITES EXCEPT FOR KAVL WHERE SKIES SCT OUT. OTHERWISE...LOW VFR CIGS ARE POSSIBLE AT KGSP/KGMU ASSOCIATED WITH THE ABOVE MENTIONED 850 TROF AXIS OVERNIGHT. ALL OTHER SITES WILL REMAIN SCT/FEW AROUND 6KFT. LIGHT WINDS WILL BACK NORTHWESTERLY THURSDAY MORNING AT ALL SITES BEHIND THE PASSAGE OF THE APPROACHING WEAK SFC BOUNDARY...WITH THE EXCEPTION OF KAVL WHICH REMAINS NORTHWESTERLY THROUGH THE PERIOD. WINDS WILL INCREASE ACROSS THE REGION TO AROUND THE 8-10KTS RANGE LATE THURSDAY MORNING AT ALL SITES EXCEPT KAVL WHERE SUSTAINED FLOW AROUND THE 12KT RANGE WITH 20-25KT GUSTS IS EXPECTED. OUTLOOK...DRY/VFR THU-FRI...BUT PRECIPITATION AND ASSOCIATED RESTRICTIONS ARE POSSIBLE EARLY SAT. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... THERE IS LITTLE CHANGE IN THINKING FROM THE PREVIOUS FORECAST CYCLE. THE PLANNING FORECAST HAS BEEN UPDATED THROUGH TOMORROW BASED UPON THE LATEST FORECAST DATA...PRIMARILY FOR MINOR CHANGES IN SMOKE MANAGEMENT PARAMETERS. RH HAS ALSO BEEN LOWERED SLIGHTLY FOR THIS AFTERNOON...BUT MIN RH OF 25 PERCENT OR LESS IS EXPECTED TO BE LOCALIZED AND BRIEF...WHILE WINDS SHOULD GRADUALLY DIMINISH THROUGH THE AFTERNOON. AS THE AIR MASS BEGINS TO WARM ON THURSDAY...RH IS EXPECTED TO FALL BELOW 20 PERCENT IN MOST AREAS DURING THE AFTERNOON. IN ADDITION... W/NW WINDS WILL BEGIN TO INCREASE AHEAD OF ANOTHER DRY COLD FRONT DURING THE AFTERNOON. WINDS MAY GUST AS HIGH AS 30 MPH IN THE MTNS...AND TO AROUND 20 MPH IN THE PIEDMONT. CRITICAL WIND AND RH MAY OVERLAP FOR SEVERAL HOURS ACROSS THE MTNS AND NC FOOTHILLS THU AFTERNOON. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JPT NEAR TERM...CDG/WIMBERLEY SHORT TERM...MCAVOY LONG TERM...JPT AVIATION...CDG FIRE WEATHER...LANE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
314 PM CST WED FEB 26 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 314 PM CST WED FEB 26 2014 THE MAIN FOCUS FOR TONIGHT INTO TOMORROW IS WITH THE BLOWING SNOW TONIGHT FOLLOWED BY COLD WIND CHILLS TOMORROW MORNING. CURRENTLY...GUSTY SOUTHWEST WINDS ARE OCCURRING THROUGH MUCH OF THE REGION AS A SURFACE LOW PROPAGATES EAST ACROSS THE UPPER GREAT LAKES. THE STRONGEST WINDS HAVE BEEN ACROSS THE TYPICAL AREAS IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA WHERE SOME BLOWING AND DRIFTING SNOW HAS ALREADY REDUCED VISIBILITIES INTO THE 1 TO 2SM RANGE. AS THE MAIN MID LEVEL CLOSED LOW DROPS TO THE SOUTHEAST ACROSS ONTARIO AND A COLD FRONT MOVES THROUGH THE REGION TONIGHT...THE GRADIENT WILL TIGHTEN UP AS COLDER AIR GETS ADVECTED IN FROM THE NORTHWEST WITH SOME LIGHT SNOW ALSO OCCURRING. UPSTREAM OBSERVATIONS AND FORECAST SOUNDINGS FROM THE 26.12Z NAM/GFS AND THE 26.18Z RAP SUGGEST THAT WINDS WILL COME AROUND TO THE NORTHWEST AFTER THE FROPA AND QUICKLY INCREASE WITH SUSTAINED WINDS IN THE 20 TO 30 MPH RANGE AND GUSTS AROUND 40 MPH FOR THIS EVENING. THIS WILL LEAD TO MORE WIDESPREAD BLOWING AND DRIFTING SNOW...PARTICULARLY IN SOUTHEAST MINNESOTA...NORTHEAST IOWA AND NORTH CENTRAL WISCONSIN WHERE THE WINDS WILL BE THE HIGHEST AND THE SNOW PACK IS THE EASIEST TO BE PUSHED AROUND. BECAUSE OF THIS...THE MAIN CONCERN WAS WITH WHETHER THE ADVISORY NEEDED TO BE UPGRADED TO A BLIZZARD WARNING AND ALSO WHETHER THE ADVISORY NEEDED TO BE EXPANDED EAST AT ALL. CONFIDENCE IS NOT HIGH ENOUGH TO GO THE BLIZZARD ROUTE AT THIS POINT BECAUSE THERE HAS NOT BEEN A RECENT ACCUMULATING SNOW TO BLOW AROUND OVER THE TOP OF THE OLDER SNOW PACK. SO...WHILE SNOW WILL BLOW AND CAUSE SOME REDUCED VISIBILITIES AND SNOW COVERED ROADS...CONFIDENCE IS NOT HIGH ENOUGH TO THINK THAT THERE WILL BE WIDESPREAD ROAD CLOSURES AND WHITEOUT CONDITIONS. AS THE FRONT MOVES OFF TO THE EAST...THE COLDER AIR WILL COME INTO THE REGION AND...WHEN COMBINED WITH THE STILL GUSTY WINDS...WILL CAUSE WIND CHILLS TO DROP DOWN INTO THE 20 TO 35 DEGREES BELOW ZERO RANGE LATE TONIGHT THROUGH TOMORROW MORNING. TOYED WITH THE NEED FOR A WIND CHILL WARNING...BUT BASED ON THE FORECAST...WIND CHILLS ONLY DROP TO 35 BELOW ACROSS PORTIONS OF SE MN/NE IA/NC WI FOR A BRIEF PERIOD TOMORROW MORNING. THUS...WENT WITH AN ADVISORY FROM 3AM THROUGH NOON TOMORROW. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 314 PM CST WED FEB 26 2014 THE MAIN FOCUS THROUGH THE EXTENDED PERIOD IS ON THE TWO MAIN CHANCES FOR SNOW WHICH COME ON FRIDAY AND THEN ON SATURDAY/SATURDAY NIGHT. THE FRIDAY SYSTEM IS SHOWING GOOD CONTINUITY IN REGARD TO TIMING...BUT HAS SOME DIFFERENCES IN STRENGTH BETWEEN THE 26.12Z NAM/GFS/ECMWF. THIS SNOW IS STRICTLY COMING FROM TWO FORMS OF LOW LEVEL FORCING...THE FIRST BEING 850MB WARM AIR ADVECTION AND THEN A FRONTOGENETIC BAND THAT APPEARS TO BE THE STRONGEST AROUND 700MB. THE INITIAL WEST TO EAST BAND OF SNOW APPEARS TO DEVELOP ALONG THE NOSE OF THE STRONGEST LOW LEVEL WARM AIR ADVECTION FRIDAY MORNING/EARLY AFTERNOON WITH THE FRONTOGENESIS STRENGTHENING ALONG A SOUTHWEST TO NORTHEAST BAND FRIDAY AFTERNOON. THE HIGHER RESOLUTION 26.12Z NAM IS COMING IN WITH SOME STRONGER LOW LEVEL LIFT AND IS PRODUCING SOME HIGHER PRECIPITATION TOTALS WHILE THE 26.12Z GFS/ECMWF AS WEAKER AND HAVE ABOUT HALF OF THE QPF THAT THE NAM HAS. WITH SNOW RATIOS LOOKING LIKE THEY WILL BE AROUND 17:1...THE GOING FORECAST OF 1 TO 4 INCHES STILL LOOKS GOOD...BUT TRENDS WILL HAVE TO BE WATCHED FOR WHETHER THIS FRONTOGENESIS ENDS UP BEING STRONG ENOUGH TO PRODUCE SOME LOCALLY HIGHER AMOUNTS. THE 26.15Z SREF PLUMES SHOW THAT MOST OF THE MEMBERS...INCLUDING THE MEAN...ARE IN THE 1 TO 4 INCH RANGE...BUT THERE ARE SOME MEMBERS THAT ARE PUSHING THAT 6 INCH THRESHOLD. THE NEXT ROUND OF SNOW WILL COME ON SATURDAY AND SATURDAY NIGHT THANKS TO SOME BROAD MID LEVEL TROUGHING DIGGING DOWN INTO THE UPPER MISSISSIPPI RIVER VALLEY AND A TIGHTENING LOW TO MID LEVEL TEMPERATURE GRADIENT THAT LEADS TO SOME WEAK TO MODERATE FRONTOGENESIS. STILL SOME DIFFERING OPINIONS BETWEEN THE 26.12Z GFS/ECMWF/GEM WITH WHERE THIS SNOW ENDS UP TRACKING...BUT THE HIGHEST PROBABILITIES LIE ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN. BEYOND THIS...THE COLD CONTINUES THROUGH THE EARLY PART OF NEXT WEEK WITH SOME POSSIBLE LOW LEVEL WARMING COMING ON WEDNESDAY. THE 26.12Z ECMWF SUGGESTS THAT A SYSTEM COULD COME THROUGH ON TUESDAY/WEDNESDAY AND BRING SOME LIGHT SNOW ACROSS SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1143 AM CST WED FEB 26 2014 MAIN AVIATION FORECAST CONCERNS THROUGH THE PERIOD ARE THE INCREASING WINDS AT BOTH RST AND LSE TAF SITES THIS AFTERNOON INTO TONIGHT. LATEST SURFACE PLOT SHOWS PRESSURE GRADIENT TIGHTENING ACROSS MUCH OF THE AREA OUT AHEAD OF A COLD FRONT OVER EXTREME NORTHWEST MINNESOTA AND CENTRAL NORTH DAKOTA. WINDS THIS AFTERNOON WILL CONTINUE TO INCREASE FROM THE SOUTHWEST AT BOTH TAF SITES...WITH SUSTAINED WINDS OF 15 TO 20 KNOTS AND GUSTS OF 25 UP TO 30 KNOTS. THIS WILL CAUSE SOME DRIFTING OR BLOWING SNOW AT RST BY 21Z WEDNESDAY AND POSSIBLY REDUCTION IN VISIBILITY BELOW 5 MILES. A COLD FRONT IS EXPECTED TO MOVE ACROSS AROUND 00Z THURSDAY AT BOTH TAF SITES AND CHANGE WIND DIRECTION TO THE NORTHWEST. THE STRONG WINDS WILL CONTINUE INTO TONIGHT...AS THE PRESSURE GRADIENT REMAINS TIGHT BEHIND THE FRONT. WINDS COULD GUST AS HIGH AS 40 KNOTS AT RST AND UP TO 35 KNOTS AT LSE THIS EVENING. THE BLOWING AND DRIFTING SNOW COULD REDUCE VISIBILITY DOWN BELOW THREE MILES AT TIMES AT RST BETWEEN 00-05Z THURSDAY. FOR NOW HAVE INTRODUCED MARGINAL MVFR VISIBILITY RESTRICTION AT RST THIS EVENING. WITH THE COLD FRONT PASSAGE...THE LATEST 26.12Z MODELS ARE HINTING OF A FEW HOURS OF MVFR CEILING CONDITIONS AT BOTH RST AND LSE THIS EVENING. HAVE LEFT THIS MVFR CEILING CONDITION AT BOTH TAF SITES. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ017-029. WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR WIZ017- 029-032>034-041>044-053>055-061. MN...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ079-086- 087-094-095. WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR MNZ079- 086>088-094>096. IA...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR IAZ008>010- 018-019-029. WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR IAZ008>011-018-019-029-030. && $$ SHORT TERM...HALBACH LONG TERM...HALBACH AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
242 PM CST WED FEB 26 2014 .TONIGHT AND THURSDAY - CONFIDENCE...MEDIUM MAIN FOCUS ON THE BITTER COLD. EVENING FORECAST ISSUE WILL BE SHSN DEVELOPMENT. SHORTWAVE ENERGY SHIFTS FROM NRN WI TO THE EASTERN LAKES. LOW LEVEL FRONTOGENETICAL FORCING WITH RENEWED ARCTIC SURGE ALONG WITH STEEP LOW LEVEL LAPSE RATES...SHOULD BE ENOUGH TO GENERATE A FEW-SCT SHSN. NAM HI-RES AND HRRR BOTH AND 4KM SPC WRF ALL SHOW THIS DEVELOPMENT THIS EVENING WITH ANY LINGERING PRECIP WRAPPING UP AROUND 6Z. ONLY A FEW TENTHS OR SO AND SOME BLOWING TO GO ALONG WITH IT. STRONG COLD ADVECTION SURGE AFTER 6Z CONTINUES INTO MIDDAY WITH 925 TEMPS BOTTOMING OUT AROUND -22 TO -25C BETWEEN 12 AND 18Z. WITH AIRMASS WELL MIXED TEMPS WILL NOT BOTTOM OUT TO THAT POTENTIAL BUT TEMPS WILL DROP BY PURE ADVECTION. THIS IN CONCERT WITH TIGHT PRESSURE GRADIENT WILL ALLOW WIND CHILL ADVISORY CRITERIA TO BE MET ONCE AGAIN...SO HAVE HOISTED ONE FROM 09-18Z. .THURSDAY NIGHT...FORECAST CONFIDENCE IS HIGH. HIGH PRESSURE WILL SLIDE ACROSS THE AREA...WITH THE CENTER OF THE HIGH PASSING OVER THE DUBUQUE AREA EARLY IN THE EVENING. BY 6AM FRIDAY MORNING THE HIGH IS OVER ERN OH/WRN PA WITH THE LOW LEVEL FLOW STARTING TO PICK UP ACROSS THE FORECAST AREA. THIS HAS BEEN A TRICKY PERIOD WITH RESPECT TO LOW TEMPS DUE TO THE POTENTIAL FOR STRONG RADIATIONAL COOLING. THE GFS HAS BEEN THE MOST AGGRESSIVE OVER THE LAST FEW DAYS AND CONTINUES TO BE THE EXTREME. WARM ADVECTION HEADING TOWARD THE AREA WILL CAUSE HIGH CLOUDS TO SPREAD IN FROM THE WEST AFTER MIDNIGHT. JUST HOW COLD WE CAN GET BEFORE THAT BLANKET ARRIVES IS THE BIGGEST QUESTION. THE GUIDANCE IS NOW SUGGESTING THE COLDEST READINGS WILL BE ALONG AND JUST WEST OF THE KETTLE MORAINE SPINE IN SOUTHEAST WISCONSIN. THE HILLS OUT WEST OF MADISON MAY NOT TANK TOO LOW DUE TO THE EXPECTED CLOUDS AND BREEZE KICKING IN. IN GENERAL...HAVE BACKED OFF A BIT ON WHAT WE HAD GOING...BUT STILL WELL BELOW ZERO MOST PLACES. FAVORED COLD SPOTS IN LOW AREAS COULD GET SURPRISINGLY COLD. .FRIDAY AND FRIDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. THE WARM ADVECTION MENTIONED ABOVE WILL ARRIVE AHEAD OF AN INVERTED TROF THAT WILL ENTER WESTERN WISCONSIN FRIDAY AFTERNOON. SNOW SHOULD BEGIN TO SPREAD INTO THE WEST TOWARD LATE MORNING AND THE REST OF THE FORECAST AREA DURING THE DAY AND CONTINUE THROUGH THE EVENING BEFORE EXITING TO THE EAST AFTER MIDNIGHT. WE COULD SEE 2 TO 3 INCHES OF DRY SNOW WITH THIS. .SATURDAY INTO SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. THE OVERALL FLOW WILL HAVE BECOME ZONAL BY SATURDAY WITH A FEW RIPPLES MOVING THROUGH THE AREA...MAINLY AFFECTING FAR SOUTHERN WISCONSIN. TEMPERATURES WILL ALSO MODIFY...OR WARM...FROM THEIR DEEP CHILL...BUT STILL REMAIN BELOW NORMAL. AT THE SURFACE HIGH PRESSURE WILL STRETCH FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. THE WEAK MID LEVEL SHORT WAVES MOVING THROUGH WILL ONLY BRING CHANCES OF SOME FAIRLY LIGHT SNOW. NOTHING MAJOR...BUT WE/LL HAVE A CHANCE FOR SNOW MAINLY FROM SATURDAY AFTERNOON INTO SUNDAY...TAPERING OFF OR ENDING BY SUNDAY NIGHT. .MONDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM. THE HIGH OVER THE PLAINS IS EXPECTED TO DRIFT INTO THE AREA...BUT THE GFS AND ECMWF DIFFER ON THE SPEED/STRENGTH/PLACEMENT OF THAT HIGH BY MONDAY NIGHT. EITHER WAY...IT LOOKS DRY. && .AVIATION/00Z TAFS/...HRRR/NAM HI-RES AND OTHER SYNOPTIC MODELS SHOWING RELATIVELY SMALL WINDOW OF SHSN POTENTIAL THIS EVENING. THIS ASSOCIATED WITH NEXT ARCTIC BOUNDARY AND POTENT SHORTWAVE MOVING FROM NRN WI INTO LOWER MI. VFR CONDITIONS WILL BE PREVALENT MOST OF THIS PERIOD BUT EXPECT LOCALIZED VSBYS/CIGS TO DROP TO MAINLY MVFR WITH ANY SHSN THAT DEVELOP OR ADVECT IN. THIS WOULD MOSTLY BE IN THE 01Z-06Z TIME FRAME. && .MARINE...DECIDED TO HOIST A GALE WARNING FOR MIDNIGHT THROUGH NOON. SEEING PRETTY DECENT SIGNALS ON BUFKIT FOR A PERIOD OF GALES IN THE WAKE OF THE LATEST ARCTIC FRONT COMING THROUGH THIS EVENING. THE GOING SMALL CRAFT WILL LEAD UP TO THE GALE WARNING AND THEN WILL LIKELY BE NEEDED FOR A WHILE AT THE CONCLUSION OF THE GALE WARNING. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR WIZ046- 047-051-052-056>060-062>072. LM...SMALL CRAFT ADVISORY UNTIL 4 PM CST THURSDAY FOR LMZ643>646. && $$ TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR THURSDAY NIGHT THROUGH WEDNESDAY...DAVIS