Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/01/15


AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
911 AM PST FRI FEB 27 2015 .UPDATE... MAIN FOCUS FOR THE UPDATE IS TO ISSUE A WINTER WEATHER ADVISORY FOR THE SIERRA FRONT TONIGHT INTO SATURDAY. AS FOR THE REST OF TODAY, DID MAKE SOME MINOR CHANGES TO ADD THE THREAT OF THUNDERSTORMS NORTH OF I-80 THIS AFTERNOON AND REDUCE SOME CLOUD COVER TO MAKE IT MORE MOSTLY CLOUDY AS THERE WILL BE BREAKS OF SUN. REGARDING THE CONVECTION, MODERATE SHOWERS ARE ALREADY POPPING NORTH OF HIGHWAY 50 AND THESE SHOULD INTENSIFY WITH HEATING. MODELS ALL SHOWING ENOUGH INSTABILITY FOR SOME ISOLATED THUNDERSTORMS AS WELL. TONIGHT INTO SATURDAY MORNING, THE GFS AND EC CONTINUE TO SHOW A BAND OF MODERATE SNOW TO AFFECT PORTIONS OF THE TAHOE BASIN AND SIERRA FRONT. HIGH CONFIDENCE NOW IN THIS BAND DEVELOPING AS THE LATEST HRRR IS SHOWING IT AT THE END OF ITS RUN. LATEST RUNS HAVE ALSO SHIFTED IT SOUTH AGAIN OVER DOUGLAS COUNTY AND SOUTH LAKE. ADVISORY ALREADY ISSUED FOR TAHOE AND WILL ADD THE SIERRA FRONT TO RUN FROM 8 PM TONIGHT UNTIL 10 AM TOMORROW MORNING. OUTSIDE OF THIS BAND LIGHTER AMOUNTS NEAR 2 INCHES FOR THE SIERRA FRONT AND UP TO 4 INCHES FOR THE TAHOE BASIN ARE LIKELY. HOWEVER, IN THIS BAND EXPECT HEAVIER AMOUNTS AS MODEL QPF IS NEAR 1/2 TO 3/4 INCH IN PLACES. WITH A GOOD DENTRITIC SNOW GROWTH LAYER PRESENT, IT COULD ADD UP. WILL GO WITH 3-6 INCHES IN THIS BAND FOR THE SIERRA FRONT AND 4-8 FOR THE TAHOE BASIN WITH 12+ INCHES POSSIBLE ABOVE 7K. WILL MENTION THE MOST LIKELY PLACES (OR OUR BEST GUESS) FOR THE HEAVIER BAND. HOWEVER, THE EXACT LOCATION REMAINS LOW CONFIDENCE. IT IS STILL POSSIBLE IT COULD BE CENTERED OVER CARSON CITY OR EVEN TRUCKEE/RENO (LOWEST PROBABILITY FOR THE LATTER). HOPE TO HAVE ALL UPDATES OUT BY 10 AM. WALLMANN && .PREVIOUS DISCUSSION... /ISSUED 324 AM PST FRI FEB 27 2015/ SYNOPSIS... WINTER SYSTEM IS ON TRACK TO IMPACT THE SIERRA AND NORTHWEST NEVADA TODAY AND SATURDAY. ACCUMULATING SNOW AND DIFFICULT TRAVEL CONDITIONS ARE LIKELY IN THE SIERRA WITH LIGHTER ACCUMULATIONS POSSIBLE IN WESTERN NEVADA. THIS SYSTEM WILL SLOWLY EXIT SUNDAY WITH ANOTHER CHANCE AT PRECIPITATION POSSIBLE LATE MONDAY INTO TUESDAY. SHORT TERM... THE UPPER LEVEL LOW RESPONSIBLE FOR THE THE WINTER WEATHER THIS WEEKEND IS CURRENTLY DROPPING SOUTH ALONG THE PACIFIC NORTHWEST COAST. AHEAD OF THIS FEATURE, WEAK WARM AIR ADVECTION IS GENERATING LIGHT PRECIPITATION EARLY THIS MORNING. THE LOW WILL CONTINUE SOUTH TODAY, PUSHING A DIFFUSE COLD FRONT THROUGH THE EASTERN SIERRA AND WESTERN NEVADA AND BRINGING GUSTY WEST TO NORTHWEST WINDS TO THE REGION THIS AFTERNOON. THE FRONT WILL RAPIDLY DROP SNOW LEVELS TO AROUND 4000-5000 FEET FRIDAY NIGHT, POSSIBLY REACHING AS LOW AS 3500 FEET BY SATURDAY MORNING. MOST OF THE MOISTURE IS ALONG AND BEHIND THE FRONT WITH SHOWERS EXPECTED TO INCREASE IN COVERAGE THIS AFTERNOON AND EVENING. SHOWER ACTIVITY IS RATHER DISORGANIZED, OUTSIDE OF A DEFORMATION BAND EXPECTED TO FORM LATE TONIGHT INTO SATURDAY. THESE BANDS ARE NOTORIOUSLY HARD TO PINPOINT LOCATIONS, BUT MODEL TRENDS OVER THE PAST COUPLE DAYS ARE SHOWING THIS BAND DEVELOPING BETWEEN THE I-80 AND HIGHWAY 50 CORRIDOR. CONFIDENCE IS HIGH THAT THERE WILL BE SNOW SHOWERS BOTH IN THE SIERRA AND WESTERN NEVADA, BUT MUCH LOWER IN THE TOTALS. THE SHOWERY NATURE OF THIS SYSTEM MEANS THAT SNOW TOTALS WILL BE HIGHLY VARIABLE. THE GREATEST CONFIDENCE IN ACCUMULATING SNOWS IS THROUGH THE TAHOE BASIN WHERE A WINTER WEATHER ADVISORY IS IN EFFECT LATE FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON. 6 TO 12 INCHES OF SNOW IS POSSIBLE ALONG THE CREST, WITH 3 TO 7 INCHES AT LAKE LEVEL. THOSE LOCATIONS UNDER ANY ORGANIZED BANDS WILL BE ON THE HIGHER END OF THE TOTALS, WHILE LOCATIONS WITH JUST GENERAL SHOWERS WILL BE ON THE LOWER END. FOR WESTERN NEVADA AND THE SIERRA FRONT, CONFIDENCE IS INCREASING IN SOME AREAS SEEING SEVERAL INCHES OF ACCUMULATION, BUT CONFIDENCE REMAINS LOW IN EXACTLY WHERE...AND SOME AREAS MAY STILL SEE NOTHING. MONO COUNTY IS LIKELY TO SEE ACCUMULATING SNOWS SATURDAY AFTERNOON INTO SUNDAY AS THE UPPER LEVEL FLOW TURNS NORTHEAST, AIDING IN UPSLOPE ENHANCEMENT. CURRENT FORECAST WOULD YIELD 6 TO 10 INCHES OF SNOW IN THE HIGH SIERRA WITH 2 TO 4 INCHES IN THE REST OF MONO COUNTY. THE BIGGEST THING TO TAKE AWAY IS THAT TRAVEL WILL LIKELY BE IMPACTED FRIDAY AFTERNOON THROUGH SUNDAY THROUGH PORTIONS OF THE SIERRA AND WESTERN NEVADA. BE PREPARED FOR WINTER DRIVING CONDITIONS AND CHECK BOTH WEATHER AND ROAD CONDITIONS BEFORE TRAVEL. THERE IS PLENTY OF INSTABILITY WITHIN THE CORE OF THE LOW AND THERE IS A SLIGHT CHANCE OF THUNDERSTORMS NORTH OF I-80 LATE THIS AFTERNOON AND THEN FROM I-80 SOUTH SATURDAY. PELLET SHOWERS AND/OR A WINTRY MIX IS POSSIBLE THROUGH THE DAY SATURDAY IN THE COLD CORE. THE LOW IS SLOWER TO EXIT THE AREA THAN PREVIOUSLY PROGGED, WITH SHOWERS POSSIBLY LINGERING IN MONO COUNTY THROUGH SUNDAY AFTERNOON IN THE MOIST AND UNSTABLE NORTHEAST FLOW. TEMPERATURES WILL BE BELOW NORMAL THROUGH THE PERIOD WITH THE BREEZY WINDS MAKING IT FEEL EVEN COLDER. DJ LONG TERM...MONDAY THROUGH THURSDAY... NO MAJOR CHANGES TO THE LONG TERM FORECAST, WITH THE MAIN WEATHER CONSIDERATION MONDAY INTO TUESDAY ANY ADDITIONAL SLIDER ENERGY (AND ASSOCIATED SNOW SHOWERS) THAT MIGHT MOVE OVER EASTERN CALIFORNIA AND WESTERN NEVADA BEHIND THIS WEEKEND`S SYSTEM. MONDAY AND MONDAY NIGHT, THE ECMWF, GFS AND GEM ENSEMBLES STILL SHOW VARYING SOLUTIONS REGARDING A SLIDER-TYPE DISTURBANCE TO MOVE OVER/NEAR THE REGION. IN FACT, IN THE LAST FEW OPERATIONAL RUNS THE GFS AND ECMWF HAVE GONE THE OPPOSITE WAY WITH THE GFS LEANING FARTHER EAST AND MORE PROGRESSIVE WITH THE ECMWF GETTING SLOWER AND FARTHER WEST (OVER NORTHERN CALIFORNIA) WITH THE SLIDER. MEANWHILE, THE GEM SEEMS TO BE IN BETWEEN WITH MANY ENSEMBLE RUNS SHOWING THE DISTURBANCE OVER WESTERN NEVADA OR FAR EASTERN CALIFORNIA. THE POSITION OF THE SLIDER IS KEY FOR THE COVERAGE/INTENSITY OF SNOW SHOWERS FOR THE SIERRA AND WESTERN NEVADA, WITH A TRACK NEAR OR WEST OF THE CREST (BUT STILL EAST OF I-5) IDEAL FOR AN ORGANIZED BAND OF SNOW. WITH LARGE UNCERTAINTY AS TO THE EXACT TRACK OF THE DISTURBANCE MONDAY-TUESDAY, I HAVE KEPT THE RUNNING SLIGHT CHANCE TO CHANCE OF SHOWERS IN PLACE. IN ANY CASE, WELL BELOW AVERAGE TEMPERATURES ARE ON TAP FOR MONDAY AND TUESDAY WITH NORTHERLY FLOW KEEPING COLDER AIR INTACT. WEDNESDAY AND THURSDAY STILL LOOK DRY AS ENSEMBLES ARE IN GOOD AGREEMENT WITH BUILDING A RIDGE OVERHEAD. TEMPERATURES WILL BEGIN TO REBOUND TOWARDS NORMAL FOR THE SECOND HALF OF THE WEEK. SNYDER AVIATION... FOR THIS MORNING IN NORTHEAST CALIFORNIA AND WESTERN NEVADA, SCATTERED SHOWERS WILL BRING OCCASIONAL MVFR CIGS TO THE NORTHERN SIERRA WITH OCCASIONAL HIGHER TERRAIN OBSCUREMENT TO WESTERN NEVADA NORTH OF HIGHWAY 50. NORTH OF KSVE-GERLACH, CIGS LOOK WORSE WITH WIDESPREAD MVFR CIGS WITH -SHSN ABV 5-5.5 KFT MSL (AND -SHRASN BLO). THIS AFTERNOON AND TONIGHT, CIGS/VIS WORSEN AS LOW PRESSURE DROPS INTO NORTHERN CALIFORNIA AND NEVADA AND WIDESPREAD SNOW AND RAIN/SNOW BELOW 5,000 FT MSL DEVELOPS. WIDESPREAD IFR CIGS AND ICING ARE EXPECTED IN THE SIERRA, WITH MVFR (LOCALLY IFR) CIGS INTO WESTERN NEVADA NORTH OF HIGHWAY 50. ACCUMULATING SNOW IS LIKELY FOR KTRK/KTVL WITH EVEN SOME ACCUMULATIONS POSSIBLE AT KRNO/KCXP (60% CHANCE) BETWEEN LATE FRIDAY EVENING AND SATURDAY MORNING. FOR KMMH, THE WORSE CONDITIONS ARE LIKELY TO BE ON SATURDAY. SNYDER && .REV WATCHES/WARNINGS/ADVISORIES... NV...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM PST SATURDAY NVZ002. WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST SATURDAY NVZ003. CA...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM PST SATURDAY CAZ072. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1242 PM EST FRI FEB 27 2015 .SYNOPSIS... WEAK IMPULSE MOVES THROUGH THE AREA TODAY FOLLOWED BY AN EXTENSIVE HIGH PRESSURE SYSTEM FOR A MAJORITY OF THE WEEKEND. AS THE HIGH SLIPS OFF THE COAST ON SUNDAY A WEAK WARM FRONT LIFTS THROUGH THE REGION AS LOW PRESSURE PASSES TO OUR WEST AND ITS ASSOCIATED COLD FRONT PUSHES THROUGH ON MONDAY. ANOTHER LOW PRESSURE EJECTS OUT OF THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY. THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CLOUDS HAVE CONTINUED TO BREAK UP IN MOST PLACES THIS AFTERNOON. SO WILL FEATURE A MOSTLY SUNNY AFTERNOON ACROSS THE REGION. THE LATEST RAP AND HRRR MODEL RUNS DO NOT FORM ANY SNOW FLURRIES EITHER ACROSS THE REGION. INCREASED TEMPERATURES A DEGREE OR TWO WARMER WITH THE 12:30 PM UPDATE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... AT LEAST ONE MODEL IS DEPICTING LOW LEVEL CLOUDS DEVELOPING BY THIS EVENING. HOWEVER, THIS SEEMS UNLIKELY WITH THE SYNOPTIC PATTERN OF A SURFACE HIGH SLIDING EAST TOWARD THE REGION AS FLOW ALOFT TRANSITIONS TO MORE ZONAL FLOW. THEREFORE, EXPECT CLEARING SKIES THIS EVENING INTO THE OVERNIGHT HOURS. THIS, COMBINED WITH SUBSIDENCE IN THE LOW LEVELS AND LIGHT WINDS WILL LEAD TO PRIME RADIATIONAL COOLING CONDITIONS, ESPECIALLY FOR LOCATIONS THAT STILL HAVE A SNOW PACK. THUS, WENT SLIGHTLY BELOW GUIDANCE FOR LOWS. && .LONG TERM /SATURDAY THROUGH THURSDAY/... MEDIUM RANGE GUIDANCE IS IN PRETTY DECENT AGREEMENT WITH THE LARGE SCALE FEATURES THROUGH THE EXTENDED PERIOD. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY DEEPENING RIDGING THROUGH MID- WEEK AS THE LONGWAVE TROUGH RELOADS TO OUR WEST AND ADVANCES THROUGH LATE IN THE PERIOD. SATURDAY...HIGH PRESSURE WILL BE OVERHEAD ALLOWING FOR LOTS OF SUBSIDENCE AND MOSTLY CLEAR SKIES. TEMPERATURES WILL BE RATHER COLD STILL, NEARLY 20 DEGREES UNDER CLIMO FOR THE LAST DAY OF METEOROLOGICAL WINTER. SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION VERY LATE SUNDAY INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE. DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE COLD FRONT WITH ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX OF RAIN/SNOW/SLEET/FREEZING RAIN OCCURS, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY MORNING. THERE COULD BE SOME WAK COLD AIR DAMMING OCCURRING, EVEN AS WINDS TURN MORE EASTERLY, BUT GIVEN THE ARCTIC HIGH WILL BE OFFSHORE AND NOT EXPECTING A HUGE RESPONSE IN THE LOW-LEVEL WINDS THE GROUND COULD STILL BE COLD ENOUGH FOR SOME LIGHT FREEZING RAIN...MORE SO THEN WE ARE CURRENTLY CARRYING IN THE FORECAST. THE BEST CHANCES FOR AN ALL SNOW EVENT REMAINS ACROSS OUR NORTHERN MOST ZONES WHERE THE WARM NOSE GETS CLOSE BUT DOES NOT HAVE ENOUGH PUSH TO MOVE THROUGH, PRIOR TO THE COLD FRONT USHERING IN ANOTHER SHOT OF COLDER AIR. WE ARE CURRENTLY CARRYING A FEW INCHES OF SNOW ACROSS THE POCONOS AT THIS TIME. TUESDAY - THURSDAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO BE ANOTHER MIXED EVENT. THIS SYSTEMS COLD FRONT DRAGS THROUGH RATHER SLOWLY, AS THE TROUGHING TO OUR WEST SHARPENS AND SLOWS IT DOWN A BIT. THIS COULD ALLOW FOR A LONGER DURATION EVENT SO WE CARRY CHANCE POPS THROUGH THE FIRST HALF OF THURSDAY BEFORE DRYING OUT. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS THROUGH THE TAF PERIOD. SOME SCATTERED CLOUDS THIS AFTERNOON AROUND 5,000 FEET SHOULD CLEAR OUT THIS EVENING BEFORE CIRRUS ABOVE 10,000 FEET MOVES IN OVERNIGHT. NORTHWESTERY WINDS FROM 320-350 DEGREES AS WELL, TOP WINDS AROUND 10 KNOTS THIS AFTERNOON. WIND COULD SHIFT MORE WESTERLY WITH SLIGHTLY LOWERING CIRRUS IN THE AFTERNOON ON SATURDAY. OUTLOOK... SATURDAY NIGHT - SUNDAY MORNING...VFR. NORTHERLY WINDS PREVAIL AS HIGH PRESSURE NOSES IN FROM THE WEST. SUNDAY NIGHT - MONDAY...MVFR/IFR EXPECTED WITH SNOW TO RAIN/FREEZING RAIN POSSIBLE BY EARLY MONDAY MORNING. TUESDAY...VFR. && .MARINE... WITH THE MORNING UPDATE WE DID RAISE WAVE HEIGHTS BASED ON BUOY OBS TO BETWEEN FIVE AND SIX FEET. THIS LEADS TO A HIGHER CONFIDENCE SCA SEAS WILL PERSIST THROUGH THE LATE AFTERNOON. WINDS HAVE ALREADY SUBSIDED AND SHOULD REMAIN BELOW SCA CRITERIA TODAY AND TONIGHT, ALTHOUGH A FEW GUSTS NEAR 20 KT ARE POSSIBLE OVER THE OCEAN WATERS THIS EVENING. WAVE HEIGHTS SHOULD START TO DECREASE TONIGHT. OUTLOOK... SATURDAY - SUNDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN ZONES. SUNDAY NIGHT - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN APPROACHING COLD FRONT WITH INCREASING SOUTHERLY WINDS AND BUILDING SEAS EXPECTED. BETTER CHANCE BEHIND COLD FRONT PASSAGE ON MONDAY WITH GUSTY WEST WINDS. TUESDAY...SUB-SCA EXPECTED. && .CLIMATE... RECORDS FOR FRIDAY AND SATURDAY. NOTE RECORDS FOR FRIDAY UNLIKELY BUT POSTED JUST IN CASE ONE OR 2 ARE APPROACHED AT 1159 PM FRIDAY EVENING. THERE IS A GREATER CHANCE OF RECORDS SATURDAY. POR / SITE / FEB 27 FEB 28 1872 / KPHL / 6 1900 9 1934 1874 / KACY / 7 1934* 2 1934 1894 / KILG / 5 1934 -5 1934 1922 / KABE / -2 1963 -10 1934 1869 / KRDG / 4 1934* 3 1934 1865 / KTTN / 6 1934 1 1934 1948 / KGED / 10 1963 8 1950 1901 / KMPO / -9 1993 -15 1907 KACY RER FOR 3/1 IS 5 IN 1980. NOTE: * INDICATE AND OTHER YEARS. NOTE: POR = PERIOD OF RECORD,THE YEAR OFFICIAL CLIMATE OBS BEGAN. THE FOLLOWING IS A TABLE OF THE ***PROJECTED*** TOP 5 COLDEST FEBRUARY`S ON RECORD, BASED ON THE CURRENT FORECAST, AND THUS SUBJECT TO CHANGE. EACH RANKING DENOTES THE MEAN FEBRUARY TEMPERATURE /F/ AND YEAR OF OCCURRENCE. WE REREVIEWED THESE PROJECTIONS LISTED BELOW USING THIS THURSDAY MORNINGS (26TH) MINS AND THE PHI FCST AS SEEN ON NDFD AND SFT`S. WE SEE PHL/ABE/ILG ALL VERY CLOSE TO YESTERDAYS PROJECTIONS. KACY CHANGED TO A WARMER PROJECTION HOWEVER THAT COULD YET REVERT BACK TO A COLDER MONTHLY AVERAGE DUE TO THE POTENTIAL FOR RADIATIONAL COOLING ON ONE OR 2 OF THE MORNINGS. POR / SITE / 1ST RANK / 2ND RANK / 3RD RANK / 4TH RANK / 5TH RANK 1872 / KPHL / 22.2(1934) 23.0(1979) 24.3(1885) 24.6(1978) 25.5(2015) 1874 / KACY / 21.6(1979) 23.8(1978/1934) 24.5(2015) 25.5(1875) 25.7 (1905) 1894 / KILG / 20.2(1934) 22.1(1979) 22.7(1978) 24.5(2015) 24.9(1936) 1922 / KABE / 16.6(1934) 18.9(2015) 20.4(1979) 21.6(1936) 22.0(1963) PER THE ABOVE TABLE, ABE IS EASILY ON TRACK FOR THE SECOND COLDEST FEBRUARY, ATLANTIC CITY 3RD COLDEST FOLLOWED BY THE FOURTH COLDEST AT ILG, AND THE FIFTH COLDEST AT PHL. THE FOLLOWING IS A TABLE OF THE ***PROJECTED*** MEAN FEBRUARY 2015 TEMPERATURES /F/ AND DEPARTURES FROM NORMAL. THIS IS ALSO BASED ON THE CURRENT FORECAST, AND THUS SUBJECT TO CHANGE. JANUARY 2015 MEAN TEMPERATURES ARE ALSO INCLUDED FOR COMPARISON PURPOSES. POR / SITE / FEB MEAN(F) / FEB NORMAL(F) / DEPARTURE / JAN MEAN(F) 1872 / KPHL / 25.5 / 35.7 / -10.2 / 30.9 1874 / KACY / 24.5 / 35.3 / -10.8 / 30.2 1894 / KILG / 24.5 / 35.1 / -10.6 / 30.3 1922 / KABE / 18.9 / 30.7 / -11.8 / 25.9 IN GENERAL, MEAN TEMPERATURES AT OUR FOUR MAJOR CLIMATE SITES ARE ON TRACK TO BE AROUND 10 TO 12 DEGREES BELOW NORMAL FOR FEBRUARY 2015. IT`S ALSO INTERESTING TO NOTE THAT THE PROJECTED FEBRUARY 2015 MEAN TEMPERATURES WILL BE WELL BELOW THE JANUARY 2015 MEAN TEMPERATURES. TO PUT THIS IN PERSPECTIVE, NORMAL MEAN FEBRUARY TEMPERATURES AT OUR FOUR MAJOR CLIMATE SITES ARE ABOUT 2 TO 3 DEGREES WARMER THAN JANUARY. THE OPPOSITE IS SHAPING UP FOR FEBRUARY 2015. ALSO...OF INTEREST...THIS WOULD ALSO BE THE SECOND COLDEST MONTHLY MEAN TEMPERATURE ON RECORD AT ALLENTOWN SINCE RECORDS BEGAN IN 1922; FEBRUARY 1934 BEING THE COLDEST! PHL PROJECTS AROUND 12TH COLDEST MONTHLY MEAN SINCE RECORDS BEGAN IN 1873. ATLANTIC CITY 7TH COLDEST MONTHLY MEAN SINCE RECORDS BEGAN THERE IN 1874. WILMINGTON HAS MISSING DATA IN ITS DATABASE (1897-1916) AND SO WE DON`T FOCUS AS MUCH ATTENTION ON THAT RECORD. && EQUIPMENT: TEMPERATURE AT GED MAY BE RUNNING SEVERAL DEGREES TO WARM, TECHS ARE WORKING ON ISSUE. NOT USED IN 12:30 PM UPDATE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST THIS AFTERNOON FOR ANZ450>455. && $$ SYNOPSIS...HEAVENER/O`HARA NEAR TERM...GAINES SHORT TERM...DRAG/JOHNSON LONG TERM...HEAVENER AVIATION...GAINES MARINE...GAINES/HEAVENER/JOHNSON CLIMATE...STAFF EQUIPMENT... GAINES
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
932 PM EST SAT FEB 28 2015 .DISCUSSION... THE RAINFALL IS BEGINNING TO TAPER OFF THIS EVENING...BUT NOT BEFORE DUMPING 1 TO 3 INCHES OF RAIN ACROSS THE REGION OVER THE PAST 12 HOURS. MOST OF THIS RAIN WAS ALONG THE I-4 CORRIDOR AND NORTHWARD. THERE ARE STILL A FEW AREAS THAT ARE PRODUCING MODERATE RAINFALL MOVING INTO NORTHERN POLK COUNTY...SOUTHERN HIGHLANDS COUNTY AND OVER CHARLOTTE COUNTY. THE HRRR GUIDANCE HAS THESE POCKETS DISSIPATING BY MIDNIGHT WITH ONLY ISOLATED SHOWERS EXPECTED OVERNIGHT. THE 00Z SOUNDING IS SHOWING ABUNDANT MOISTURE THROUGHOUT THE COLUMN WHICH WILL SUPPORT CONTINUED CLOUDY SKIES THROUGH THE NIGHT. AS FOR TEMPERATURES...WE ARE NOT LOOKING FOR MUCH CHANGE OVERNIGHT SO TEMPS SHOULD BOTTOM OUT ABOVE AVERAGE WITH LOWS IN THE UPPER 50S ALONG THE NATURE COAST AND MID TO UPPER 60S FROM TAMPA BAY SOUTHWARD. PATCHY FOG WILL ALSO BE POSSIBLE DURING THE EARLY MORNING HOURS. I MADE SOME MINOR TWEAKS TO POPS TO REFLECT CURRENT RADAR COVERAGE...EVERYTHING ELSE LOOKS FINE. WILL SEND UPDATED ZONES WITH THOSE CHANGES SOON. && .AVIATION... FOR THE MOST PART...CONDITIONS HAVE IMPROVED ACROSS THE REGION WITH VFR CONDITIONS AT THE NORTHERN TERMINALS AND TEMPO MVFR CONDITIONS FOR THE SOUTHERN TERMINALS. CONDITIONS ARE EXPECTED TO CONTINUE IMPROVING AFTER MIDNIGHT WITH VFR REGION WIDE. WINDS WILL REMAIN OUT OF THE EAST NORTHEAST IN THE 5 TO 10 KNOT RANGE. && .MARINE... ISOLATED SHOWERS WILL CONTINUE ACROSS THE WATERS THROUGH THE FIRST PART OF TONIGHT. NORTHEAST WINDS AROUND EXERCISE CAUTION LEVELS FOR THE NORTHERN WATERS WILL DIMINISH AFTER MIDNIGHT OR SO...WITH THE REST OF THE ZONES REMAINING BELOW HEADLINES. && .PRELIMINARY POINT TEMPS/POPS... TPA 63 79 64 80 / 20 20 30 10 FMY 66 84 65 83 / 30 20 20 10 GIF 65 81 64 81 / 30 30 20 20 SRQ 64 79 63 79 / 20 20 20 10 BKV 61 79 58 81 / 30 20 20 20 SPG 65 77 65 78 / 20 20 20 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/AVIATION...74/WYNN MARINE...05/CARLISLE DECISION SUPPORT...09/RUDE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
225 AM CST FRI FEB 27 2015 .UPDATE... 827 PM CST LAKE EFFECT SNOW IS STARTING TO WIND DOWN AS DRIER AIR MASS ADVECTS INTO THE AREA ALLOWING FOR A WEAKENING OF THE BROKEN LES BAND THAT HAD PERSISTED ALL DAY. AS PROGRESSIVELY DRIER AIR CONTINUED TO FILTER IN TONIGHT AND EVENTUALLY ONSHORE COMPONENT TO FLOW WEAKENS WOULD ANTICIPATE LES TO END IN PORTER COUNTY LATER THIS EVENING OR JUST PAST MIDNIGHT. GIVEN EXPECTATIONS AND RECENT RADAR TRENDS MAY SHORTEN THE DURATION OF THE LAKE EFFECT SNOW WARNING IN THE NEXT HOUR OR TWO IF NOT CANCEL IT OUTRIGHT. ELSEWHERE CLOUDINESS OVER SOUTHERN PORTIONS OF THE CWA IS LIKELY TO SLOWLY DISSIPATE AND MOVE OUT LEAVING SKIES FAIRLY CLEAR ACROSS THE AREA. CENTER OF THE HIGH PRESSURE IS STILL HUNDREDS OF MILE TO OUR NORTHWEST BUT WITH FRESH SNOW PACK WOULD EXPECT GRADIENT TO BE WEAK ENOUGH FOR WINDS TO FURTHER DECOUPLE OVERNIGHT...ESPECIALLY WITH HIGH GROWING CLOSER IN TIME. SUSPECT THAT THE WIND CHILL ADVISORY WILL BE HARD PRESSED TO VERIFY MOST AREAS WITH THE TYPICALLY COLDER VALLEYS LIKELY SEEING WINDS GO CALM...LIKELY KRPJ AND KFRD ALREADY HAVE OR WINDS TO STAY UP ENOUGH TO KEEP TEMPS FROM TANKING. THE TOOTHPASTE IS OUT OF THE PROVERBIAL TUBE SO NOT PLANNING ANY CHANGES TO THE WIND CHILL ADVISORY SINCE A FEW LOCATIONS COULD TAG ADVISORY FOR AN HOUR OR TWO AND IT WILL BE VERY COLD. IZZI && .SHORT TERM... THROUGH SATURDAY... 243 PM...LAKE EFFECT IS NOW ORGANIZING INTO A SINGLE BAND AS WINDS TURN MORE NORTHWEST ACROSS NORTHEAST IL AND THIS BAND IS SHIFTING TO THE SOUTHEAST AND WILL BE OUT OF COOK COUNTY IN THE NEXT HOUR OR SO. WILL BE EXPIRING LAKE COUNTY IL FROM THE WARNING AND FOR NOW WILL LET COOK COUNTY RIDE UNTIL 6 PM...BUT IF CURRENT TRENDS CONTINUE...IT PROBABLY WILL BE CANCELED EARLY. HI RES GUIDANCE IS IN REASONABLE AGREEMENT THAT THE LAKE EFFECT BAND WILL SHIFT INTO PORTER COUNTY BY EARLY/MID EVENING...SO EXPECTED AMOUNTS IN NORTHERN LAKE COUNTY INDIANA ARE A BIT UNCERTAIN BUT WITH RATES OF 1-2 INCHES PER HOUR IN THE BAND...ITS POSSIBLE SOME ISOLATED AMOUNTS OF 3 TO 6 INCHES WILL BE POSSIBLE. MORE CONFIDENCE WITH AMOUNTS INTO NORTHERN PORTER COUNTY AS THE BAND REMAINS THERE FROM MID EVENING THROUGH THE OVERNIGHT HOURS WITH LOCALLY 4 TO 7 INCHES...PERHAPS MOSTLY NEAR THE LAKE. THE BAND THEN BEGINS TO SHIFT OUT OF THE LAKE TOWARD MORNING. SO NOT PLANNING ANY CHANGES TO THE WARNING END TIME FOR EITHER LAKE OR PORTER COUNTIES...THOUGH CONFIDENCE REGARDING WHEN EXACTLY PRECIP ENDS IS A BIT UNCERTAIN. HIGH PRESSURE BUILDS ACROSS THE MIDWEST TONIGHT AND THEN MOVES ACROSS THE AREA ON FRIDAY. WINDS WILL SLOWLY DIMINISH OVERNIGHT BUT LIKELY REMAIN IN THE 5-10 MPH. THIS COMBINED WITH TEMPS DROPPING WELL BELOW ZERO AWAY FROM CHICAGO WILL RESULT IN WINDS CHILLS 20 BELOW TO 25 BELOW ZERO ACROSS THE NORTHERN CWA AND INTO THE 15 BELOW RANGE SOUTH OF I-80. VALUES ARE BIT MARGINAL INTO CHICAGO AND ALONG THE I-80 CORRIDOR BUT PLAN TO ISSUE A WIND CHILL ADVISORY OVERNIGHT INTO FRIDAY MORNING GENERALLY ALONG AND NORTH OF I-80 IN ILLINOIS. DESPITE THE LIGHT WINDS AND SUNNY SKIES ON FRIDAY AS THE HIGH SLOWLY MOVES ACROSS THE AREA...THE AIRMASS WILL REMAIN VERY COLD WITH HIGHS ONLY REACHING THE MID TO PERHAPS UPPER TEENS. TEMPS WILL LIKELY TANK FRIDAY NIGHT AS THE HIGH SHIFTS EAST AND LIGHT WINDS TURN SOUTHERLY. SATURDAY WILL BE DRY AND A BIT WARMER WITH HIGHS IN THE LOWER/MID 20S WITH INCREASING CLOUDS IN THE AFTERNOON. CMS && .LONG TERM... SATURDAY NIGHT THROUGH THURSDAY... THE TIME FRAME WILL START OUT ACTIVE AS A PERIOD OF ACCUMULATING SNOW IS APPEARING LIKELY SATURDAY NIGHT INTO SUNDAY. STEADILY INCREASING UPPER LEVEL FLOW OUT AHEAD OF DIGGING TROUGH TO THE NORTH WILL ALLOW SHORT WAVE ENERGY TO TRAVERSE THE REGION DURING THIS PERIOD...WHILE ONGOING WAA PERSISTS. THIS SHOULD ALLOW SNOW TO SPREAD NORTHEAST ACROSS THE CWA DURING THE EVENING HOURS WITH SNOW LIKELY ACROSS MUCH OF THE CWA AFTER THE MIDNIGHT TIME FRAME...THEN LIKELY CONTINUING INTO SUNDAY AFTERNOON. MOST GUIDANCE IN AGREEMENT WITH OVERALL LARGE SCALE SETUP DURING THIS TIME AND EVEN WITH THIS SNOW SPREADING OVER THE CWA. HOWEVER...THERE DOES APPEAR TO BE SOME TIMING DIFFERENCES OF THE ONSET AND TIMING OF BEST SNOWFALL. SO I DO FEEL IT WILL SNOW AND HAVE LIKELY POPS OVER THE ENTIRE CWA LATE SATURDAY NIGHT INTO SUNDAY MORNING...BUT DID NOT GO TO CATEGORICAL BASED ON THE PREVIOUSLY MENTIONED UNCERTAINTIES. ONLY MINOR CHANGES MADE TO THE CURRENT SNOW FORECAST WITH THE BEST FORCING AND HIGHEST SNOWFALL TOTALS CURRENTLY EXPECTED TO BE SOUTH OF I80. WHILE MOST OF THE CWA WILL LIKELY OBSERVE ACCUMULATING SNOWFALL...THE SOUTHERN CWA COULD APPROACH ADVISORY TYPE SNOW. HOWEVER I WONDER IF MY CURRENT TOTAL MIGHT BE A LITTLE TOO HIGH...ESPECIALLY WITH THE ANTICIPATED DRIVING MECHANISMS OF THIS SNOW...BUT THE LONGER DURATION OF THIS LIGHT TO AT TIME MODERATE SNOW COULD HELP FOR THE CURRENT FORECAST TOTALS. SYSTEM SNOW WILL DEPART TO THE EAST LATE SUNDAY AND SUNDAY EVENING...AS HIGH PRESSURE BUILDS ACROSS THE REGION. EARLY NEXT WEEK APPEARS TO BEGIN QUIET...BUT WITH ACTIVE WEATHER RETURNING THROUGH MIDWEEK. HIGHLY AMPLIFIED PATTERN WITH UPPER LEVEL RIDGE OVER THE EASTERN US AND A DIGGING TROUGH OVER THE WESTERN CONUS WILL BE IN PLACE ON TUESDAY...AS DEEPENING SURFACE LOW APPROACHES THE CWA FROM THE SOUTHWEST. STRONG WARM AIR AND MOIST ADVECTION IS ANTICIPATED MONDAY NIGHT AND ESPECIALLY TUESDAY/TUESDAY NIGHT. THIS WILL NOT ONLY PROVIDE THE POTENTIAL FOR INITIAL VARYING PRECIP TYPE BUT WITH ALSO STEADIER RAINFALL...AS A BROAD AREA OF PRECIP IS EXPECTED TO ACCOMPANY THIS SYSTEM. EC AND GFS SIMILAR WITH REGARDS TO WAA...BUT WITH THE GFS NOT AS ROBUST WITH THE MOISTURE ADVECTION AS THE EC IS APPEARING TO BE. IF THE EC WERE TO VERIFY...THEN SURFACE DEWPOINTS COULD APPROACH 50 DEG AND 850MB DEWPOINTS APPROACHING 10-11C. THIS WILL BE CONCERNING FOR POSSIBLE HYDRO ISSUES...ESPECIALLY WITH THE ANTICIPATED SNOW THIS WEEKEND. THERMAL PROFILES SUPPORTIVE OF ALL RAIN ON TUESDAY AND ALTHOUGH I HAVENT INCLUDED THUNDER IN THE GRIDS AT THIS TIME...WILL NEED TO MONITOR THIS POTENTIAL AS WELL...ESPECIALLY FOR THE SOUTHERN CWA. RODRIGUEZ && .CLIMATE... TEMPERATURES ARE FORECAST ONCE AGAIN TO BE CLOSE OR BREAK THE FOLLOWING DAILY RECORDS THROUGH THE END OF THE MONTH...INCLUDING ONE ON FRIDAY IN ROCKFORD THAT WAS SET JUST LAST WINTER: ROCKFORD... FRIDAY FEB 27TH LOW MAXIMUM: 15 IN 2014 SATURDAY FEB 28TH LOW: -7 IN 1962 SATURDAY FEB 28TH LOW MAXIMUM: 17 IN 1962 CHICAGO... FRIDAY FEB 27TH LOW: -6 IN 1897 SATURDAY FEB 28TH LOW: 0 IN 1884 MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NONE. RATZER //DISCUSSION...UPDATED 06Z... HIGH PRESSURE CENTERED OVER THE MID-MISSOURI VALLEY EARLY THIS MORNING WILL SPREAD SLOWLY EAST-SOUTHEAST ACROSS THE REGION THROUGH TONIGHT. LIGHT NORTHWEST WINDS WILL BECOME WEST DURING THE DAY AND SOUTHWEST TONIGHT...WITH SPEEDS GENERALLY LESS THAN 10 KT. DRY ARCTIC AIR MASS WILL MAKE FOR MAINLY CLEAR SKIES THROUGH THE PERIOD. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH FOR ALL ELEMENTS. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... SATURDAY...VFR THEN SNOW DEVELOPING SATURDAY NIGHT. IFR LIKELY. SUNDAY...PERIODS OF ACCUMULATING SNOW ENDING BY LATE AFTERNOON. IFR LIKELY. MONDAY...VFR THEN CHANCE OF WINTRY MIX AND IFR MONDAY NIGHT. TUESDAY...RAIN AND IFR LIKELY...POSSIBLY ENDING AS LIGHT SNOW TUESDAY NIGHT. IFR WEDNESDAY...MVFR POSSIBLE. RC && .MARINE... 219 AM CST MAIN PERIOD OF CONCERN FOR GUSTY 20-30 KT WINDS LOOKS TO BE SUNDAY NIGHT INTO EARLY MONDAY...AND POTENTIALLY AGAIN ON WEDNESDAY. MUCH OF LAKE REMAINS ICE COVERED...WITH ONLY THE CENTRAL AND SOUTHERN PORTIONS WELL AWAY FROM SHORE APPEARING OPEN IN RECENT SATELLITE DATA. HIGH PRESSURE CENTERED OVER THE MID-MISSOURI RIVER VALLEY WILL MOVE EAST-SOUTHEAST ACROSS THE MIDWEST SOUTH OF THE LAKES THROUGH TONIGHT AND TO THE MID-ATLANTIC REGION BY LATE SATURDAY. MEANWHILE...LOW PRESSURE WILL MOVE ACROSS HUDSON BAY TODAY...WITH A DEEPER TROUGH DEVELOPING NORTH OF THE LAKES SATURDAY. THIS WILL RESULT IN WINDS BECOMING WESTERLY OVER LAKE MICHIGAN TODAY...INCREASING A BIT INTO THE 20 KT RANGE TONIGHT AS THE GRADIENT TIGHTENS UP BETWEEN THE HIGH PASSING SOUTH OF THE LAKES AND LOW PRESSURE FARTHER TO THE NORTH. SATURDAY INTO SUNDAY...WINDS WILL SHIFT TO THE SOUTH-SOUTHWEST AS A COLD FRONTAL TROUGH APPROACHES FROM THE NORTHWEST. THE FRONT WILL PASS ACROSS THE LAKE SUNDAY WITH A SHIFT BACK TO THE WEST...BECOMING NORTHWEST AND BECOMING GUSTY 25-30 KT SUNDAY NIGHT INTO MONDAY MORNING AS HIGH PRESSURE MOVES IN FROM THE WEST AND BRIEFLY TIGHTENS THE GRADIENT ONCE AGAIN. THE HIGH WILL MOVE ACROSS THE SOUTHERN LAKES AND MIDWEST MONDAY WITH NORTHWEST WINDS QUICKLY DIMINISHING AND EVENTUALLY BECOMING SOUTHEASTERLY MONDAY NIGHT AS THE HIGH SLIDES OFF TO THE EAST. MEDIUM-RANGE MODEL RUNS INDICATE LOW PRESSURE WILL MOVE NEAR SOUTHERN LAKE MICHIGAN TUESDAY OR TUESDAY NIGHT. CURRENT INDICATIONS ARE THAT SOUTHEAST WINDS WILL INCREASE TUESDAY INTO THE 20 KT RANGE OR SO...BEFORE BRIEFLY DECREASING AND VEERING NORTH-NORTHWEST BY EARLY WEDNESDAY AND INCREASING INTO THE 25-30 KT RANGE AS COLDER AIR ONCE AGAIN SURGES IN. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022 UNTIL 9 AM FRIDAY. IN...LAKE EFFECT SNOW WARNING...INZ002 UNTIL 6 AM FRIDAY. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1139 PM CST Thu Feb 26 2015 .UPDATE... ISSUED AT 900 PM CST THU FEB 26 2015 Small area of clouds continues to slowly move south this evening. Also, some isolated flurries are also still occurring under this cloud cover. Expect this to continue, mainly in eastern areas of the CWA. This will eventually clear up overnight. Current forecast has a good handle on this and with temp trends the rest of the night. No update planned at this time. && .SHORT TERM...(Tonight) ISSUED AT 249 PM CST THU FEB 26 2015 Will issue a wind chill advisory for areas along and north of a Jacksonville to Springfield to Decatur to Paris line overnight into mid Fri morning for wind chills of 15-24F below zero with the coldest wind chills in Knox and Stark counties around dawn Friday. Wind chills reach near or below 15F below near Galesburg around midnight, and se toward I-72 later tonight. Lows overnight to range from 5-10F below zero from the IL river valley nw to zero to 5F above in southeast IL from I-70 se. Broken to overcast low clouds still cover much of IL with some clearing far west central and northern IL near WI border. Still getting scattered light snow showers and areas of flurries over central IL (visibilities as low as 2-5 miles) due to lingering moisture off lake MI along with a short wave dropping se into the area. HRRR may be a bit too progressive in clearing low clouds from north to south during early and mid evening. Low clouds to likely decrease over IL river valley early this evening, but thinking it may take until overnight for decreasing of low clouds in southeast IL since short wave still affecting southern counties tonight. Also lingered chance of flurries from I-55 east late this afternoon and early evening and into mid evening in southeast IL. Strong 1042 mb arctic high pressure near the MT/ND and southern Saskatchewan border and ridging SSE into the Great Plains to settle se into IA/MO by Friday morning bringing dry weather and bitter cold temperatures overnight into Fri morning. North winds 10-17 mph and gusts 18-24 mph this afternoon will veer nw and decrease to 5-10 mph overnight. && .LONG TERM...(Friday through Thursday) ISSUED AT 249 PM CST THU FEB 26 2015 Morning upper air and satellite imagery depicts trough over the central plains with clipper shortwave moving over IL, producing continued light snow in strong 850mb cold air advection. Wave continuing to move east and will break up in afternoon. Ridge of high pressure to build in overnight, again producing wind chills. Ridge to move off to the east through Friday and into Saturday. By Saturday afternoon, overrunning from the next system begins to develop into plains. NAM model brings snow into western IL and feel not unreasonable. Will therefore add slight chc pops Sat afternoon, with main pcpn Sat night to Sunday. Models similar in development of frontal zone from western plains low into Ozarks, with significant lift over boundary Saturday night. This will push snow formation into central IL Saturday night, continuing into Sunday. Main lift is Saturday night as upper wave moves across great lakes, with pcpn lingering into Sunday. Diminshed the pcpn Sun night as high pressure builds in. Upper flow changes Monday to Tuesday, with pcpn again developing into Monday night to Tuesday as surface low center develops in plains and moves northeast, west of cwa though. The result is that with this feature, area stays in the warm section and so pcpn starts as freezing rain and changes to rain. Still uncertainty though, as the operational models are very different on the timing of the system movement. made few changes due to these differences. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) ISSUED AT 1139 PM CST THU FEB 26 2015 VFR conditions will prevail at all TAF sites next 24hrs. Clouds around 4.5kft are still effecting BMI/DEC/CMI late tonight but are slowly moving southeast and should clear BMI and DEC by 06z, and CMI by 09z. Will keep a 2hr TEMPO group for DEC and CMI just because it seems these clouds are just lingering and will not go quickly. Then clear skies should prevail remainder of the TAF period. Winds will be northwest overnight and then become light and variable tomorrow. && .ILX WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY until 10 AM CST Friday FOR ILZ027>031- 036>038-040>051-053-055-057. && $$ UPDATE...Auten SHORT TERM...07 LONG TERM...Goetsch AVIATION...Auten
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
309 PM EST FRI FEB 27 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 303 AM EST FRI FEB 27 2015 HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT THE AREA TOWARDS THE MIDDLE OF NEXT WEEK. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1025 AM EST FRI FEB 27 2015 CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING ADVISORY CRITERIA. OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST OF THE AREA. RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY. RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20 SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN MOST MOS GUIDANCE. THIS SEEMS REASONABLE. THERE SHOULD BE A LOT OF SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS THIS AFTERNOON. REST OF NEAR TERM SEEMS TO BE ON TRACK. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... ISSUED AT 303 AM EST FRI FEB 27 2015 DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT. WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES. BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 230 PM EST FRI FEB 27 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. SOUTHWEST FLOW ALOFT IN THE FIRST PART OF THE LONG TERM WILL ALLOW NEAR TO ABOVE AVERAGE TEMPERATURES AS AN AREA OF LOW PRESSURE MOVES TO THE NORTH OF CENTRAL INDIANA. HOWEVER AN UPPER TROUGH WILL MOVE INTO THE AREA FOR THE END OF THE PERIOD ALLOWING WELL BELOW NORMAL TEMPERATURES ONCE AGAIN. LOOKS LIKE PRECIPITATION WILL MAINLY ARRIVE OVERNIGHT MONDAY NIGHT INTO EARLY TUESDAY. MODELS STILL ARE BRINGING IN WARM AIR ALOFT QUICKLY...SO MIXED PRECIPITATION TO FREEZING RAIN LOOKS TO BE THE PRECIPITATION TYPE MONDAY NIGHT. SURFACE TEMPERATURES STILL LOOK TO BE COLD TUESDAY MORNING SO KEPT THE FREEZING RAIN MENTION THEN. AS WARM AIR AT THE SURFACE FINALLY ARRIVES RAIN WILL FALL LATER TUESDAY MORNING THROUGH THE REMAINDER OF THE DAY. COULD BE ENOUGH RAIN TO CAUSE SOME FLOODING ISSUES GIVEN THE FROZEN GROUND. WILL CONTINUE TO MONITOR CLOSELY. MODELS DIFFER IN SPEED OF COLD AIR RETURNING TUESDAY NIGHT BUT STILL FEEL IT A MIX OF RAIN AND SNOW IS WARRANTED AS PRECIPITATION TYPE MOST AREAS. AS A WAVE RIDES ALONG THE FRONT ON WEDNESDAY PRECIPITATION CHANCES WILL CONTINUE...WITH CHANCES FOR SNOW NORTHWEST AND RAIN/SNOW SOUTHEAST. THURSDAY AND FRIDAY LOOK TO BE DRY AND COLD WITH HIGH PRESSURE MOVING IN. && .AVIATION /DISCUSSION FOR THE 27/2100Z TAF UPDATE/... ISSUED AT 307 PM EST FRI FEB 27 2015 UPDATE... NO CHANGES. PREVIOUS DISCUSSION... VFR EXPECTED THROUGH THE PERIOD WITH WINDS GENERALLY LESS THAN 10KT. SCATTERED /TO PERHAPS BRIEFLY BROKEN AT KIND/KBMG/ CU FIELD WILL DISSIPATE WITH LOSS OF HEATING NEAR SUNSET. OTHERWISE MID AND HIGH CLOUDS WILL INCREASE TONIGHT AND SATURDAY AHEAD OF NEXT SYSTEM. WINDS WILL BECOME LIGHT THIS EVENING AND THEN SOUTHEAST AT LESS THAN 10KT SATURDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...JAS NEAR TERM...JH SHORT TERM...JAS LONG TERM....50 AVIATION...50/TDUD VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
230 PM EST FRI FEB 27 2015 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 303 AM EST FRI FEB 27 2015 HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT THE AREA TOWARDS THE MIDDLE OF NEXT WEEK. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1025 AM EST FRI FEB 27 2015 CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING ADVISORY CRITERIA. OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST OF THE AREA. RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY. RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20 SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN MOST MOS GUIDANCE. THIS SEEMS REASONABLE. THERE SHOULD BE A LOT OF SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS THIS AFTERNOON. REST OF NEAR TERM SEEMS TO BE ON TRACK. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... ISSUED AT 303 AM EST FRI FEB 27 2015 DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT. WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES. BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 230 PM EST FRI FEB 27 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. SOUTHWEST FLOW ALOFT IN THE FIRST PART OF THE LONG TERM WILL ALLOW NEAR TO ABOVE AVERAGE TEMPERATURES AS AN AREA OF LOW PRESSURE MOVES TO THE NORTH OF CENTRAL INDIANA. HOWEVER AN UPPER TROUGH WILL MOVE INTO THE AREA FOR THE END OF THE PERIOD ALLOWING WELL BELOW NORMAL TEMPERATURES ONCE AGAIN. LOOKS LIKE PRECIPITATION WILL MAINLY ARRIVE OVERNIGHT MONDAY NIGHT INTO EARLY TUESDAY. MODELS STILL ARE BRINGING IN WARM AIR ALOFT QUICKLY...SO MIXED PRECIPITATION TO FREEZING RAIN LOOKS TO BE THE PRECIPITATION TYPE MONDAY NIGHT. SURFACE TEMPERATURES STILL LOOK TO BE COLD TUESDAY MORNING SO KEPT THE FREEZING RAIN MENTION THEN. AS WARM AIR AT THE SURFACE FINALLY ARRIVES RAIN WILL FALL LATER TUESDAY MORNING THROUGH THE REMAINDER OF THE DAY. COULD BE ENOUGH RAIN TO CAUSE SOME FLOODING ISSUES GIVEN THE FROZEN GROUND. WILL CONTINUE TO MONITOR CLOSELY. MODELS DIFFER IN SPEED OF COLD AIR RETURNING TUESDAY NIGHT BUT STILL FEEL IT A MIX OF RAIN AND SNOW IS WARRANTED AS PRECIPITATION TYPE MOST AREAS. AS A WAVE RIDES ALONG THE FRONT ON WEDNESDAY PRECIPITATION CHANCES WILL CONTINUE...WITH CHANCES FOR SNOW NORTHWEST AND RAIN/SNOW SOUTHEAST. THURSDAY AND FRIDAY LOOK TO BE DRY AND COLD WITH HIGH PRESSURE MOVING IN. && .AVIATION /DISCUSSION FOR 271800Z TAF ISSUANCE/... ISSUED AT 1142 AM EST FRI FEB 27 2015 VFR EXPECTED THROUGH THE PERIOD WITH WINDS GENERALLY LESS THAN 10KT. SCATTERED /TO PERHAPS BRIEFLY BROKEN AT KIND/KBMG/ CU FIELD WILL DISSIPATE WITH LOSS OF HEATING NEAR SUNSET. OTHERWISE MID AND HIGH CLOUDS WILL INCREASE TONIGHT AND SATURDAY AHEAD OF NEXT SYSTEM. WINDS WILL BECOME LIGHT THIS EVENING AND THEN SOUTHEAST AT LESS THAN 10KT SATURDAY. && .IND WATCHES/WARNINGS/ADVISORIES... IND...NONE. && $$ SYNOPSIS...JAS NEAR TERM...JH SHORT TERM...JAS LONG TERM....50 AVIATION...50 VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1142 AM EST FRI FEB 27 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 303 AM EST FRI FEB 27 2015 HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT THE AREA TOWARDS THE MIDDLE OF NEXT WEEK. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1025 AM EST FRI FEB 27 2015 CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING ADVISORY CRITERIA. OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST OF THE AREA. RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY. RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20 SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN MOST MOS GUIDANCE. THIS SEEMS REASONABLE. THERE SHOULD BE A LOT OF SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS THIS AFTERNOON. REST OF NEAR TERM SEEMS TO BE ON TRACK. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... ISSUED AT 303 AM EST FRI FEB 27 2015 DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT. WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES. BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY. && .LONG TERM /MONDAY THROUGH THURSDAY/... ISSUED AT 258 AM EST FRI FEB 27 2015 ACTIVE PATTERN CONTINUES THROUGH THE FIRST HALF OF NEXT WEEK AS PIECES OF ENERGY ALOFT EJECT OUT OF THE TROUGH OVER THE WESTERN U S FOLLOWED BY THE TROUGH AXIS ITSELF MOVING EAST INTO THE REGION BY THE END OF THE PERIOD. HIGH CONFIDENCE IN A SIGNIFICANT WEATHER IMPACT FOR CENTRAL INDIANA AND THE OHIO VALLEY MONDAY NIGHT THROUGH WEDNESDAY. STRONG HIGH PRESSURE ARRIVES IN THE WAKE OF THE LATE WEEKEND SYSTEM FOR MONDAY...AND SHOULD SERVE TO GIVE THE REGION A BREATHER BETWEEN WEATHER SYSTEMS ON THE ORDER OF 18 TO 24 HOURS. SURFACE WAVE SET TO SPIN UP OVER THE CENTRAL ROCKIES MONDAY NIGHT AS ENERGY EJECTS OUT FROM THE PARENT TROUGH. THIS FEATURE WILL SWING E/NE AND TRACK QUICKLY INTO THE REGION BY TUESDAY EVENING AND BRING WITH IT A PLETHORA OF MESSY PROBLEMS FOR CENTRAL INDIANA. RIDGING DEVELOPING DOWNSTREAM OF THE TROUGH SUPPORTS MORE AMPLIFIED FLOW WITH THE SURFACE WAVE TRACKING THROUGH OR NORTH OF THE FORECAST AREA. OP GFS SHOWING ITS USUAL PROGRESSIVE BIAS IN THE MID RANGE IN BRINGING PRECIP IN TOO QUICKLY...ESPECIALLY CONSIDERING THE STRENGTH OF THE DEPARTING HIGH. LIKE THE LOOK OF THE ECMWF/GGEM WHICH DELAYS MOST PRECIP UNTIL AFTER MIDNIGHT MONDAY NIGHT. WARM ADVECTION WILL ALREADY BE ONGOING WHEN PRECIP STARTS...AND EXPECT PRECIP TYPE ISSUES FROM THE GET GO WITH A GROWING LIKELIHOOD THAT FREEZING RAIN IS THE PREDOMINANT PRECIP TYPE INTO TUESDAY MORNING. THE REFRESHED SNOWPACK COURTESY OF THE WEEKEND STORM WILL BE A SIGNIFICANT FACTOR IN DURATION OF FROZEN PRECIP AS THE NEAR SURFACE/GROUND TEMPS WILL LAG THE LOW LEVEL TEMP RISES. MODEL THERMAL PROFILES ARE ALREADY SUGGESTIVE THAT IT MAY TAKE UNTIL MIDDAY TUESDAY IN SOME PORTIONS OF THE REGION TO WARM SUFFICIENTLY FOR ALL RAIN. IF THE IMPACT OF THE SNOWCOVER IS UNDERMINED BY THE MODELS WHATSOEVER...THE ICING POTENTIAL COULD BE EVEN MORE SIGNIFICANT. DO NOT EXPECT TO HAVE A GOOD HANDLE ON THIS UNTIL LATER IN THE WEEKEND. WHILE THE ICING THREAT IS A GROWING ISSUE...AN EXTENDED PERIOD OF HEAVY RAIN OVER A FROZEN GROUND AND SNOW COVER POSES EVEN GREATER CONCERNS. COPIOUS AMOUNTS OF MOISTURE WILL BE DRAWN NORTH INTO THE REGION AHEAD OF THE APPROACHING SURFACE WAVE TUESDAY AND TUESDAY NIGHT. PRECIP WATER VALUES ARE PARTICULARLY ALARMING...MAXING OUT BETWEEN 1.25 AND 1.50 INCHES TUESDAY EVENING. THESE LEVELS WOULD PLACE THE REGION NEAR AND ABOVE THE 99TH PERCENTILE FOR CLIMATOLOGICAL PRECIP WATER VALUES IN MARCH. POTENTIAL FOR CONVECTIVE ELEMENTS TO THE PRECIP AS WELL AND MAY NEED TO ADD AN ISOLATED THUNDER MENTION INTO THE FORECAST FOR TUESDAY AFTERNOON/NIGHT. 1-2 INCHES OF RAINFALL CERTAINLY LOOK PLAUSIBLE AND WITH MOST OF THIS BEING CONVERTED TO PURE RUNOFF WITH THE FROZEN GROUND...FLOODING CONCERNS ARE VALID. FRONTAL BOUNDARY SHOULD FINALLY MOVE EAST WEDNESDAY WITH PRECIP ENDING LATE DAY...LIKELY AS A RAIN/SNOW MIX. MUCH COLDER AIR WILL THEN RETURN FOR THE END OF THE WEEK. STILL PLENTY TO HASH OUT AND THE WEEKEND WINTER STORM WILL HAVE SOME SAY IN HOW THIS ALL TRANSPIRES. AS STATED ABOVE THOUGH...CONFIDENCE IS HIGH IN SIGNIFICANT WEATHER IMPACTS FOR CENTRAL INDIANA MONDAY NIGHT THROUGH WEDNESDAY...WITH ICING...HEAVY RAIN AND FLOODING ALL POTENTIAL CONCERNS. ENCOURAGE HOOSIERS TO STAY ABREAST OF THE FORECAST OVER THE NEXT FEW DAYS. && .AVIATION /DISCUSSION FOR 271800Z TAF ISSUANCE/... ISSUED AT 1142 AM EST FRI FEB 27 2015 VFR EXPECTED THROUGH THE PERIOD WITH WINDS GENERALLY LESS THAN 10KT. SCATTERED /TO PERHAPS BRIEFLY BROKEN AT KIND/KBMG/ CU FIELD WILL DISSIPATE WITH LOSS OF HEATING NEAR SUNSET. OTHERWISE MID AND HIGH CLOUDS WILL INCREASE TONIGHT AND SATURDAY AHEAD OF NEXT SYSTEM. WINDS WILL BECOME LIGHT THIS EVENING AND THEN SOUTHEAST AT LESS THAN 10KT SATURDAY. && .IND WATCHES/WARNINGS/ADVISORIES... IND...NONE. && $$ SYNOPSIS...JAS NEAR TERM...JH SHORT TERM...JAS LONG TERM....RYAN AVIATION...50 VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1025 AM EST FRI FEB 27 2015 .UPDATE... NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 303 AM EST FRI FEB 27 2015 HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT THE AREA TOWARDS THE MIDDLE OF NEXT WEEK. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1025 AM EST FRI FEB 27 2015 CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING ADVISORY CRITERIA. OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST OF THE AREA. RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY. RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20 SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN MOST MOS GUIDANCE. THIS SEEMS REASONABLE. THERE SHOULD BE A LOT OF SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS THIS AFTERNOON. REST OF NEAR TERM SEEMS TO BE ON TRACK. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... ISSUED AT 303 AM EST FRI FEB 27 2015 DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT. WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES. BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY. && .LONG TERM /MONDAY THROUGH THURSDAY/... ISSUED AT 258 AM EST FRI FEB 27 2015 ACTIVE PATTERN CONTINUES THROUGH THE FIRST HALF OF NEXT WEEK AS PIECES OF ENERGY ALOFT EJECT OUT OF THE TROUGH OVER THE WESTERN U S FOLLOWED BY THE TROUGH AXIS ITSELF MOVING EAST INTO THE REGION BY THE END OF THE PERIOD. HIGH CONFIDENCE IN A SIGNIFICANT WEATHER IMPACT FOR CENTRAL INDIANA AND THE OHIO VALLEY MONDAY NIGHT THROUGH WEDNESDAY. STRONG HIGH PRESSURE ARRIVES IN THE WAKE OF THE LATE WEEKEND SYSTEM FOR MONDAY...AND SHOULD SERVE TO GIVE THE REGION A BREATHER BETWEEN WEATHER SYSTEMS ON THE ORDER OF 18 TO 24 HOURS. SURFACE WAVE SET TO SPIN UP OVER THE CENTRAL ROCKIES MONDAY NIGHT AS ENERGY EJECTS OUT FROM THE PARENT TROUGH. THIS FEATURE WILL SWING E/NE AND TRACK QUICKLY INTO THE REGION BY TUESDAY EVENING AND BRING WITH IT A PLETHORA OF MESSY PROBLEMS FOR CENTRAL INDIANA. RIDGING DEVELOPING DOWNSTREAM OF THE TROUGH SUPPORTS MORE AMPLIFIED FLOW WITH THE SURFACE WAVE TRACKING THROUGH OR NORTH OF THE FORECAST AREA. OP GFS SHOWING ITS USUAL PROGRESSIVE BIAS IN THE MID RANGE IN BRINGING PRECIP IN TOO QUICKLY...ESPECIALLY CONSIDERING THE STRENGTH OF THE DEPARTING HIGH. LIKE THE LOOK OF THE ECMWF/GGEM WHICH DELAYS MOST PRECIP UNTIL AFTER MIDNIGHT MONDAY NIGHT. WARM ADVECTION WILL ALREADY BE ONGOING WHEN PRECIP STARTS...AND EXPECT PRECIP TYPE ISSUES FROM THE GET GO WITH A GROWING LIKELIHOOD THAT FREEZING RAIN IS THE PREDOMINANT PRECIP TYPE INTO TUESDAY MORNING. THE REFRESHED SNOWPACK COURTESY OF THE WEEKEND STORM WILL BE A SIGNIFICANT FACTOR IN DURATION OF FROZEN PRECIP AS THE NEAR SURFACE/GROUND TEMPS WILL LAG THE LOW LEVEL TEMP RISES. MODEL THERMAL PROFILES ARE ALREADY SUGGESTIVE THAT IT MAY TAKE UNTIL MIDDAY TUESDAY IN SOME PORTIONS OF THE REGION TO WARM SUFFICIENTLY FOR ALL RAIN. IF THE IMPACT OF THE SNOWCOVER IS UNDERMINED BY THE MODELS WHATSOEVER...THE ICING POTENTIAL COULD BE EVEN MORE SIGNIFICANT. DO NOT EXPECT TO HAVE A GOOD HANDLE ON THIS UNTIL LATER IN THE WEEKEND. WHILE THE ICING THREAT IS A GROWING ISSUE...AN EXTENDED PERIOD OF HEAVY RAIN OVER A FROZEN GROUND AND SNOW COVER POSES EVEN GREATER CONCERNS. COPIOUS AMOUNTS OF MOISTURE WILL BE DRAWN NORTH INTO THE REGION AHEAD OF THE APPROACHING SURFACE WAVE TUESDAY AND TUESDAY NIGHT. PRECIP WATER VALUES ARE PARTICULARLY ALARMING...MAXING OUT BETWEEN 1.25 AND 1.50 INCHES TUESDAY EVENING. THESE LEVELS WOULD PLACE THE REGION NEAR AND ABOVE THE 99TH PERCENTILE FOR CLIMATOLOGICAL PRECIP WATER VALUES IN MARCH. POTENTIAL FOR CONVECTIVE ELEMENTS TO THE PRECIP AS WELL AND MAY NEED TO ADD AN ISOLATED THUNDER MENTION INTO THE FORECAST FOR TUESDAY AFTERNOON/NIGHT. 1-2 INCHES OF RAINFALL CERTAINLY LOOK PLAUSIBLE AND WITH MOST OF THIS BEING CONVERTED TO PURE RUNOFF WITH THE FROZEN GROUND...FLOODING CONCERNS ARE VALID. FRONTAL BOUNDARY SHOULD FINALLY MOVE EAST WEDNESDAY WITH PRECIP ENDING LATE DAY...LIKELY AS A RAIN/SNOW MIX. MUCH COLDER AIR WILL THEN RETURN FOR THE END OF THE WEEK. STILL PLENTY TO HASH OUT AND THE WEEKEND WINTER STORM WILL HAVE SOME SAY IN HOW THIS ALL TRANSPIRES. AS STATED ABOVE THOUGH...CONFIDENCE IS HIGH IN SIGNIFICANT WEATHER IMPACTS FOR CENTRAL INDIANA MONDAY NIGHT THROUGH WEDNESDAY...WITH ICING...HEAVY RAIN AND FLOODING ALL POTENTIAL CONCERNS. ENCOURAGE HOOSIERS TO STAY ABREAST OF THE FORECAST OVER THE NEXT FEW DAYS. && .AVIATION /DISCUSSION FOR 271500Z TAF UPDATE/... ISSUED AT 920 AM EST FRI FEB 27 2015 ONLY TWEAKED KIND WIND DIRECTION. STILL SOME UNCERTAINTY ON WHERE BROKEN CUMULUS FIELD WILL SET UP...SO LEFT FORECAST ALONE FOR NOW. PREVIOUS DISCUSSION FOLLOWS... VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD. HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TODAY WITH PARTLY CLOUDY SKIES. POCKETS OF STRATOCU CONTINUE TO DROP INTO CENTRAL INDIANA WITH LOW LEVEL FLOW OFF LAKE MICHIGAN. DESPITE THE DRIER AIR AND SUBSIDENCE OVERSPREADING THE REGION TODAY...COLD POOL ALOFT AND PRESENCE OF 850MB THERMAL TROUGH BOTH SUPPORT RENEWED CU DEVELOPMENT FOR THE AFTERNOON...ESPECIALLY AT KBMG AND KIND. AS CU SCATTERS OUT LATER THIS AFTERNOON...MID AND HIGH LEVEL CLOUDS WILL INCREASE FROM THE SOUTHWEST FOR TONIGHT IN ADVANCE OF A SYSTEM DEVELOPING OVER THE SOUTHERN PLAINS. SKIES WILL BECOME OVERCAST AFTER MIDNIGHT AS CEILINGS LOWER TO 8-10KFT. NORTHWEST WINDS AT 5-10KTS TODAY WILL EVENTUALLY BECOME LIGHT AND VARIABLE OVERNIGHT. && .IND WATCHES/WARNINGS/ADVISORIES... IND...NONE. && $$ SYNOPSIS...JAS NEAR TERM...JH SHORT TERM...JAS LONG TERM....RYAN AVIATION...RYAN/50 VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1110 AM CST FRI FEB 27 2015 .UPDATE... ISSUED AT 721 AM CST FRI FEB 27 2015 RECORD LOW COLD TEMPERATURES OCCURRED TONIGHT WITH THE CLEAR SKIES AND FRESH SNOWFALL. WIND CHILLS IN A FEW LOCATIONS WERE BELOW -30. THE ONLY CHANGE TO THE FORECAST WERE THE TEMP TRENDS. EXPECT A WARM UP ONCE THE SUN STARTS HEATING AS IT IS STARTING TO BECOME THE SEASON OF HIGHER SUN ANGLES. WIND CHILL ADVISORY SHOULD STILL BE OKAY THROUGH 9AM...A FEW SITES MAY LINGER WITH SUB -20 WIND CHILLS THROUGH 10AM. && .SYNOPSIS... ISSUED AT 307 AM CST FRI FEB 27 2015 HIGH PRESSURE WAS MOVING INTO THE CENTRAL PLAINS EARLY THIS MORNING. WITH FRESH SNOWFALL AND CLEAR SKIES TEMPERATURES HAVE PLUMMETED THIS MORNING TO QUITE POSSIBLY ONE OF THE COLDEST NIGHTS OF THE YEAR. WINDS HAVE STAYED UP...WHICH HAS LEAD TO WIDESPREAD WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO WITH A FEW POCKETS OF 30 BELOW OR LOWER WIND CHILLS. WINDS ARE STARTING TO WANE AND TEMPERATURES SHOULD DROP MORE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 307 AM CST FRI FEB 27 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE TEMPERATURES TODAY AND TONIGHT ACROSS THE AREA. WITH HIGH PRESSURE IN PLACE AND FRESH SNOW COVER...GUIDANCE IS OF LITTLE HELP FOR TEMPERATURE FORECASTS. AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED...H5 RIDGING IS BUILDING INTO THE CENTRAL UNITED STATES AS A SURFACE HIGH IS PROG TO MOVE DIRECTLY OVER OUR CWA TODAY. WINDS SHOULD WANE...HOWEVER COLD AIR AND FRESH SNOWFALL WILL LEAD TO COLD TEMPERATURES TODAY AND TONIGHT. MODELS ARE OF LITTLE HELP...THIS MORNING FOR LOWS I LOADED THE OBS AND THEN MADE TWEAKS FROM THERE AS THE RUC WAS THE ONLY MODEL COLD ENOUGH WITH TEMPS. FOR TODAY AND TONIGHT...WENT WITH THE ALLBLEND AND THEN TWEAKED TEMPERATURES FROM THERE. WIND CHILLS TONIGHT SUGGEST THE NEED FOR ANOTHER WIND CHILL ADVISORY FOR AREAS NORTH OF I80. WILL DEFER TO THE DAY TO SHIFT TO DECIDE TO ISSUE THIS AS THERE IS ALREADY ONE OUT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 307 AM CST FRI FEB 27 2015 TWO STORM SYSTEMS WILL IMPACT THE EXTENDED FORECAST...AND BOTH CONTAIN POTENTIAL WINTER IMPACTS. AT THIS TIME...BOTH SYSTEMS ARE RELATIVELY POOR IN CONFIDENCE OF EXACT DETAILS CONCERNING THESE IMPACTS. TO BEGIN THE EXTENDED...HIGH PRESSURE WILL BE MOVING OFF TO THE EAST SATURDAY...AND WITH A VERY COLD START TO THE DAY...THE WEAK WAA WILL LIKELY ONLY RESULT IN HIGHS IN THE MID TEENS NORTH TO MID 20S SOUTH...DESPITE A HEALTHY AMOUNT OF LATE FEBRUARY SUNSHINE IN THE MORNING. WARM ADVECTION BY AFTERNOON...WILL BRING MID LEVEL MOISTURE NORTHWARD...WITH SOME MODELS CONTINUING TO BRUSH OUR SOUTHWEST WITH DEEPER SATURATION BY LATE AFTERNOON. THE MODEL BLEND SHOWS FAR MORE SIGNIFICANT MOISTURE ADVECTION BY SATURDAY NIGHT...AND I WILL CONTINUE TO HIGHLIGHT THAT PERIOD THROUGH SUNDAY WITH HIGH POPS. THIS EVENT IS GOING TO BE ALL SNOW...AND SHOULD HAVE RATIOS IN THE 12 TO 15 TO 1 RANGE...THUS AMOUNTS FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON SHOULD RANGE FROM AROUND 1 INCH NORTHWEST...TO 2 TO 3 INCHES FROM IOWA CITY THROUGH THE QUAD CITIES TO STERLING...TO 3 TO 5 INCHES OVER FAR SOUTHEAST IOWA NORTHEAST MISSOURI TO NEAR PRINCETON ILLINOIS. WHILE THOSE AMOUNTS ARE SUPPORTED BY THE MOST LIKELY BLEND OF GUIDANCE THAT IS INDICATED AT THIS TIME...I AM NOT CONFIDENT IN THEM YET. THE EVENT IS LIKELY GOING TO FALL INTO THE ADVISORY RANGE...ESPECIALLY DUE TO THE LONGER THAN NORMAL DURATION FOR THESE RANGE OF AMOUNTS. LOOKING AT UNCERTAINTY...THE CANADIAN MODEL IS FARTHER SOUTH THAN THE ECMWF AND GFS...AND KEEPS THE NORTHERN 3/4S OF THE CWA DRY...THUS ANOTHER REASON FOR HOLDING OFF ON ANY EARLY HEADLINE AT THIS TIME. THE 06Z NAM...THROUGH 12Z SUNDAY...ALSO KEEPS THE BULK OF MOISTURE AND FORCING SOUTH. MONDAY WILL BE A BREAK BETWEEN LOW CONFIDENCE SYSTEM...AS THE DEEP WESTERN TROF BECOMES EVEN MORE AMPLIFIED. THE MODELS HAVE SHOWN VERY LITTLE CONSISTENCY OVER THE PAST FEW DAYS AND THROUGH TONIGHT WITH RESPECT TO THE LOW TRACK...UPPER ENERGY TRACK...AND BAROCLINICITY OF THIS POTENTIAL SYSTEM. ONE FEATURE THAT HAS BEEN SHOWN CONSISTENTLY...HAS BEEN MOISTURE...WITH A SYNOPTIC SIGNAL OF AN OPEN GULF OF MEXICO...AND EVEN OPEN CARIBBEAN. THE HIGH AMOUNTS OF AVAILABLE MOISTURE ARE REASONS SUPPORTING LIKELY POPS MONDAY NIGHT AND TUESDAY. WHILE NOT CONFIDENT IN THERMAL TRANSITION TIMING...IT IS A BEST MODEL BLEND...AND CONCEPTUAL MODEL FIT FOR PCPN TO BEGIN AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN MONDAY NIGHT...TRANSITIONING TO RAIN TUESDAY...THEN BACK TO SNOW AGAIN TUESDAY NIGHT. THIS WET MESS COULD BE HIGH IMPACT...OR COULD BE LARGELY BENIGN. IT IS VERY DIFFICULT TO TELL...AND WILL KEEP A HEALTHY DOSE OF UNCERTAINTY IN OUR PRODUCTS. FOLLOWING THIS SYSTEM...COLDER DRY WEATHER SETTLES BACK IN THE A FEW DAYS BEFORE MODERATION LOOKS TO OCCUR IN ZONAL FLOW. ERVIN && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1109 AM CST FRI FEB 27 2015 VFR CONDITIONS WILL BE SEEN THROUGH 18Z/28 AS ARCTIC HIGH PRESSURE MOVES INTO THE OHIO VALLEY. && .CLIMATE... ISSUED AT 307 AM CST FRI FEB 27 2015 COULD SEE RECORD LOWS THIS MORNING AT A FEW SITES AND POSSIBLY AGAIN TONIGHT AT OTHER SITES. HERE ARE THE RECORDS FOR TONIGHT. RECORD LOWS FOR FEBRUARY 28... MOLINE.........-9 IN 1962 CEDAR RAPIDS...-17 IN 1962 DUBUQUE........-10 IN 1962 BURLINGTON.....-7 IN 1962 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...GIBBS SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...ERVIN AVIATION...08 CLIMATE...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
725 AM CST FRI FEB 27 2015 .UPDATE... ISSUED AT 721 AM CST FRI FEB 27 2015 RECORD LOW COLD TEMPERATURES OCCURRED TONIGHT WITH THE CLEAR SKIES AND FRESH SNOWFALL. WIND CHILLS IN A FEW LOCATIONS WERE BELOW -30. THE ONLY CHANGE TO THE FORECAST WERE THE TEMP TRENDS. EXPECT A WARM UP ONCE THE SUN STARTS HEATING AS IT IS STARTING TO BECOME THE SEASON OF HIGHER SUN ANGLES. WIND CHILL ADVISORY SHOULD STILL BE OKAY THROUGH 9AM...A FEW SITES MAY LINGER WITH SUB -20 WIND CHILLS THROUGH 10AM. && .SYNOPSIS... ISSUED AT 307 AM CST FRI FEB 27 2015 HIGH PRESSURE WAS MOVING INTO THE CENTRAL PLAINS EARLY THIS MORNING. WITH FRESH SNOWFALL AND CLEAR SKIES TEMPERATURES HAVE PLUMMETED THIS MORNING TO QUITE POSSIBLY ONE OF THE COLDEST NIGHTS OF THE YEAR. WINDS HAVE STAYED UP...WHICH HAS LEAD TO WIDESPREAD WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO WITH A FEW POCKETS OF 30 BELOW OR LOWER WIND CHILLS. WINDS ARE STARTING TO WANE AND TEMPERATURES SHOULD DROP MORE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 307 AM CST FRI FEB 27 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE TEMPERATURES TODAY AND TONIGHT ACROSS THE AREA. WITH HIGH PRESSURE IN PLACE AND FRESH SNOW COVER...GUIDANCE IS OF LITTLE HELP FOR TEMPERATURE FORECASTS. AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED...H5 RIDGING IS BUILDING INTO THE CENTRAL UNITED STATES AS A SURFACE HIGH IS PROG TO MOVE DIRECTLY OVER OUR CWA TODAY. WINDS SHOULD WANE...HOWEVER COLD AIR AND FRESH SNOWFALL WILL LEAD TO COLD TEMPERATURES TODAY AND TONIGHT. MODELS ARE OF LITTLE HELP...THIS MORNING FOR LOWS I LOADED THE OBS AND THEN MADE TWEAKS FROM THERE AS THE RUC WAS THE ONLY MODEL COLD ENOUGH WITH TEMPS. FOR TODAY AND TONIGHT...WENT WITH THE ALLBLEND AND THEN TWEAKED TEMPERATURES FROM THERE. WIND CHILLS TONIGHT SUGGEST THE NEED FOR ANOTHER WIND CHILL ADVISORY FOR AREAS NORTH OF I80. WILL DEFER TO THE DAY TO SHIFT TO DECIDE TO ISSUE THIS AS THERE IS ALREADY ONE OUT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 307 AM CST FRI FEB 27 2015 TWO STORM SYSTEMS WILL IMPACT THE EXTENDED FORECAST...AND BOTH CONTAIN POTENTIAL WINTER IMPACTS. AT THIS TIME...BOTH SYSTEMS ARE RELATIVELY POOR IN CONFIDENCE OF EXACT DETAILS CONCERNING THESE IMPACTS. TO BEGIN THE EXTENDED...HIGH PRESSURE WILL BE MOVING OFF TO THE EAST SATURDAY...AND WITH A VERY COLD START TO THE DAY...THE WEAK WAA WILL LIKELY ONLY RESULT IN HIGHS IN THE MID TEENS NORTH TO MID 20S SOUTH...DESPITE A HEALTHY AMOUNT OF LATE FEBRUARY SUNSHINE IN THE MORNING. WARM ADVECTION BY AFTERNOON...WILL BRING MID LEVEL MOISTURE NORTHWARD...WITH SOME MODELS CONTINUING TO BRUSH OUR SOUTHWEST WITH DEEPER SATURATION BY LATE AFTERNOON. THE MODEL BLEND SHOWS FAR MORE SIGNIFICANT MOISTURE ADVECTION BY SATURDAY NIGHT...AND I WILL CONTINUE TO HIGHLIGHT THAT PERIOD THROUGH SUNDAY WITH HIGH POPS. THIS EVENT IS GOING TO BE ALL SNOW...AND SHOULD HAVE RATIOS IN THE 12 TO 15 TO 1 RANGE...THUS AMOUNTS FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON SHOULD RANGE FROM AROUND 1 INCH NORTHWEST...TO 2 TO 3 INCHES FROM IOWA CITY THROUGH THE QUAD CITIES TO STERLING...TO 3 TO 5 INCHES OVER FAR SOUTHEAST IOWA NORTHEAST MISSOURI TO NEAR PRINCETON ILLINOIS. WHILE THOSE AMOUNTS ARE SUPPORTED BY THE MOST LIKELY BLEND OF GUIDANCE THAT IS INDICATED AT THIS TIME...I AM NOT CONFIDENT IN THEM YET. THE EVENT IS LIKELY GOING TO FALL INTO THE ADVISORY RANGE...ESPECIALLY DUE TO THE LONGER THAN NORMAL DURATION FOR THESE RANGE OF AMOUNTS. LOOKING AT UNCERTAINTY...THE CANADIAN MODEL IS FARTHER SOUTH THAN THE ECMWF AND GFS...AND KEEPS THE NORTHERN 3/4S OF THE CWA DRY...THUS ANOTHER REASON FOR HOLDING OFF ON ANY EARLY HEADLINE AT THIS TIME. THE 06Z NAM...THROUGH 12Z SUNDAY...ALSO KEEPS THE BULK OF MOISTURE AND FORCING SOUTH. MONDAY WILL BE A BREAK BETWEEN LOW CONFIDENCE SYSTEM...AS THE DEEP WESTERN TROF BECOMES EVEN MORE AMPLIFIED. THE MODELS HAVE SHOWN VERY LITTLE CONSISTENCY OVER THE PAST FEW DAYS AND THROUGH TONIGHT WITH RESPECT TO THE LOW TRACK...UPPER ENERGY TRACK...AND BAROCLINICITY OF THIS POTENTIAL SYSTEM. ONE FEATURE THAT HAS BEEN SHOWN CONSISTENTLY...HAS BEEN MOISTURE...WITH A SYNOPTIC SIGNAL OF AN OPEN GULF OF MEXICO...AND EVEN OPEN CARIBBEAN. THE HIGH AMOUNTS OF AVAILABLE MOISTURE ARE REASONS SUPPORTING LIKELY POPS MONDAY NIGHT AND TUESDAY. WHILE NOT CONFIDENT IN THERMAL TRANSITION TIMING...IT IS A BEST MODEL BLEND...AND CONCEPTUAL MODEL FIT FOR PCPN TO BEGIN AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN MONDAY NIGHT...TRANSITIONING TO RAIN TUESDAY...THEN BACK TO SNOW AGAIN TUESDAY NIGHT. THIS WET MESS COULD BE HIGH IMPACT...OR COULD BE LARGELY BENIGN. IT IS VERY DIFFICULT TO TELL...AND WILL KEEP A HEALTHY DOSE OF UNCERTAINTY IN OUR PRODUCTS. FOLLOWING THIS SYSTEM...COLDER DRY WEATHER SETTLES BACK IN THE A FEW DAYS BEFORE MODERATION LOOKS TO OCCUR IN ZONAL FLOW. ERVIN && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 544 AM CST FRI FEB 27 2015 VFR CONDITIONS THROUGH THE PERIOD WITH LIGHT WINDS AS HIGH PRESSURE SETTLES OVER THE AREA. WINDS SHOULD FAVOR W TO NW TODAY AND THEN FAVOR S TO SE OVERNIGHT. OVERALL WINDS WILL BE VERY LIGHT. ONLY CONCERN WOULD BE FRIGID TEMPERATURES TODAY AND TONIGHT. && .CLIMATE... ISSUED AT 307 AM CST FRI FEB 27 2015 COULD SEE RECORD LOWS THIS MORNING AT A FEW SITES AND POSSIBLY AGAIN TONIGHT AT OTHER SITES. HERE ARE THE RECORDS FOR TONIGHT. RECORD LOWS FOR FEBRUARY 28... MOLINE.........-9 IN 1962 CEDAR RAPIDS...-17 IN 1962 DUBUQUE........-10 IN 1962 BURLINGTON.....-7 IN 1962 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON- BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA- IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BUREAU- CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH- MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK- SCOTLAND. && $$ UPDATE...GIBBS SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...ERVIN AVIATION...GIBBS CLIMATE...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
547 AM CST FRI FEB 27 2015 .SYNOPSIS... ISSUED AT 307 AM CST FRI FEB 27 2015 HIGH PRESSURE WAS MOVING INTO THE CENTRAL PLAINS EARLY THIS MORNING. WITH FRESH SNOWFALL AND CLEAR SKIES TEMPERATURES HAVE PLUMMETED THIS MORNING TO QUITE POSSIBLY ONE OF THE COLDEST NIGHTS OF THE YEAR. WINDS HAVE STAYED UP...WHICH HAS LEAD TO WIDESPREAD WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO WITH A FEW POCKETS OF 30 BELOW OR LOWER WIND CHILLS. WINDS ARE STARTING TO WANE AND TEMPERATURES SHOULD DROP MORE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 307 AM CST FRI FEB 27 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE TEMPERATURES TODAY AND TONIGHT ACROSS THE AREA. WITH HIGH PRESSURE IN PLACE AND FRESH SNOW COVER...GUIDANCE IS OF LITTLE HELP FOR TEMPERATURE FORECASTS. AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED...H5 RIDGING IS BUILDING INTO THE CENTRAL UNITED STATES AS A SURFACE HIGH IS PROG TO MOVE DIRECTLY OVER OUR CWA TODAY. WINDS SHOULD WANE...HOWEVER COLD AIR AND FRESH SNOWFALL WILL LEAD TO COLD TEMPERATURES TODAY AND TONIGHT. MODELS ARE OF LITTLE HELP...THIS MORNING FOR LOWS I LOADED THE OBS AND THEN MADE TWEAKS FROM THERE AS THE RUC WAS THE ONLY MODEL COLD ENOUGH WITH TEMPS. FOR TODAY AND TONIGHT...WENT WITH THE ALLBLEND AND THEN TWEAKED TEMPERATURES FROM THERE. WIND CHILLS TONIGHT SUGGEST THE NEED FOR ANOTHER WIND CHILL ADVISORY FOR AREAS NORTH OF I80. WILL DEFER TO THE DAY TO SHIFT TO DECIDE TO ISSUE THIS AS THERE IS ALREADY ONE OUT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 307 AM CST FRI FEB 27 2015 TWO STORM SYSTEMS WILL IMPACT THE EXTENDED FORECAST...AND BOTH CONTAIN POTENTIAL WINTER IMPACTS. AT THIS TIME...BOTH SYSTEMS ARE RELATIVELY POOR IN CONFIDENCE OF EXACT DETAILS CONCERNING THESE IMPACTS. TO BEGIN THE EXTENDED...HIGH PRESSURE WILL BE MOVING OFF TO THE EAST SATURDAY...AND WITH A VERY COLD START TO THE DAY...THE WEAK WAA WILL LIKELY ONLY RESULT IN HIGHS IN THE MID TEENS NORTH TO MID 20S SOUTH...DESPITE A HEALTHY AMOUNT OF LATE FEBRUARY SUNSHINE IN THE MORNING. WARM ADVECTION BY AFTERNOON...WILL BRING MID LEVEL MOISTURE NORTHWARD...WITH SOME MODELS CONTINUING TO BRUSH OUR SOUTHWEST WITH DEEPER SATURATION BY LATE AFTERNOON. THE MODEL BLEND SHOWS FAR MORE SIGNIFICANT MOISTURE ADVECTION BY SATURDAY NIGHT...AND I WILL CONTINUE TO HIGHLIGHT THAT PERIOD THROUGH SUNDAY WITH HIGH POPS. THIS EVENT IS GOING TO BE ALL SNOW...AND SHOULD HAVE RATIOS IN THE 12 TO 15 TO 1 RANGE...THUS AMOUNTS FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON SHOULD RANGE FROM AROUND 1 INCH NORTHWEST...TO 2 TO 3 INCHES FROM IOWA CITY THROUGH THE QUAD CITIES TO STERLING...TO 3 TO 5 INCHES OVER FAR SOUTHEAST IOWA NORTHEAST MISSOURI TO NEAR PRINCETON ILLINOIS. WHILE THOSE AMOUNTS ARE SUPPORTED BY THE MOST LIKELY BLEND OF GUIDANCE THAT IS INDICATED AT THIS TIME...I AM NOT CONFIDENT IN THEM YET. THE EVENT IS LIKELY GOING TO FALL INTO THE ADVISORY RANGE...ESPECIALLY DUE TO THE LONGER THAN NORMAL DURATION FOR THESE RANGE OF AMOUNTS. LOOKING AT UNCERTAINTY...THE CANADIAN MODEL IS FARTHER SOUTH THAN THE ECMWF AND GFS...AND KEEPS THE NORTHERN 3/4S OF THE CWA DRY...THUS ANOTHER REASON FOR HOLDING OFF ON ANY EARLY HEADLINE AT THIS TIME. THE 06Z NAM...THROUGH 12Z SUNDAY...ALSO KEEPS THE BULK OF MOISTURE AND FORCING SOUTH. MONDAY WILL BE A BREAK BETWEEN LOW CONFIDENCE SYSTEM...AS THE DEEP WESTERN TROF BECOMES EVEN MORE AMPLIFIED. THE MODELS HAVE SHOWN VERY LITTLE CONSISTENCY OVER THE PAST FEW DAYS AND THROUGH TONIGHT WITH RESPECT TO THE LOW TRACK...UPPER ENERGY TRACK...AND BAROCLINICITY OF THIS POTENTIAL SYSTEM. ONE FEATURE THAT HAS BEEN SHOWN CONSISTENTLY...HAS BEEN MOISTURE...WITH A SYNOPTIC SIGNAL OF AN OPEN GULF OF MEXICO...AND EVEN OPEN CARIBBEAN. THE HIGH AMOUNTS OF AVAILABLE MOISTURE ARE REASONS SUPPORTING LIKELY POPS MONDAY NIGHT AND TUESDAY. WHILE NOT CONFIDENT IN THERMAL TRANSITION TIMING...IT IS A BEST MODEL BLEND...AND CONCEPTUAL MODEL FIT FOR PCPN TO BEGIN AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN MONDAY NIGHT...TRANSITIONING TO RAIN TUESDAY...THEN BACK TO SNOW AGAIN TUESDAY NIGHT. THIS WET MESS COULD BE HIGH IMPACT...OR COULD BE LARGELY BENIGN. IT IS VERY DIFFICULT TO TELL...AND WILL KEEP A HEALTHY DOSE OF UNCERTAINTY IN OUR PRODUCTS. FOLLOWING THIS SYSTEM...COLDER DRY WEATHER SETTLES BACK IN THE A FEW DAYS BEFORE MODERATION LOOKS TO OCCUR IN ZONAL FLOW. ERVIN && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 544 AM CST FRI FEB 27 2015 VFR CONDITIONS THROUGH THE PERIOD WITH LIGHT WINDS AS HIGH PRESSURE SETTLES OVER THE AREA. WINDS SHOULD FAVOR W TO NW TODAY AND THEN FAVOR S TO SE OVERNIGHT. OVERALL WINDS WILL BE VERY LIGHT. ONLY CONCERN WOULD BE FRIGID TEMPERATURES TODAY AND TONIGHT. && .CLIMATE... ISSUED AT 307 AM CST FRI FEB 27 2015 COULD SEE RECORD LOWS THIS MORNING AT A FEW SITES AND POSSIBLY AGAIN TONIGHT AT OTHER SITES. HERE ARE THE RECORDS FOR TONIGHT. RECORD LOWS FOR FEBRUARY 28... MOLINE.........-9 IN 1962 CEDAR RAPIDS...-17 IN 1962 DUBUQUE........-10 IN 1962 BURLINGTON.....-7 IN 1962 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON- BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA- IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BUREAU- CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH- MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK- SCOTLAND. && $$ SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...ERVIN AVIATION...GIBBS CLIMATE...GIBBS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
307 AM CST FRI FEB 27 2015 .SYNOPSIS... ISSUED AT 307 AM CST FRI FEB 27 2015 HIGH PRESSURE WAS MOVING INTO THE CENTRAL PLAINS EARLY THIS MORNING. WITH FRESH SNOWFALL AND CLEAR SKIES TEMPERATURES HAVE PLUMMETED THIS MORNING TO QUITE POSSIBLY ONE OF THE COLDEST NIGHTS OF THE YEAR. WINDS HAVE STAYED UP...WHICH HAS LEAD TO WIDESPREAD WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO WITH A FEW POCKETS OF 30 BELOW OR LOWER WIND CHILLS. WINDS ARE STARTING TO WANE AND TEMPERATURES SHOULD DROP MORE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 307 AM CST FRI FEB 27 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE TEMPERATURES TODAY AND TONIGHT ACROSS THE AREA. WITH HIGH PRESSURE IN PLACE AND FRESH SNOW COVER...GUIDANCE IS OF LITTLE HELP FOR TEMPERATURE FORECASTS. AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED...H5 RIDGING IS BUILDING INTO THE CENTRAL UNITED STATES AS A SURFACE HIGH IS PROG TO MOVE DIRECTLY OVER OUR CWA TODAY. WINDS SHOULD WANE...HOWEVER COLD AIR AND FRESH SNOWFALL WILL LEAD TO COLD TEMPERATURES TODAY AND TONIGHT. MODELS ARE OF LITTLE HELP...THIS MORNING FOR LOWS I LOADED THE OBS AND THEN MADE TWEAKS FROM THERE AS THE RUC WAS THE ONLY MODEL COLD ENOUGH WITH TEMPS. FOR TODAY AND TONIGHT...WENT WITH THE ALLBLEND AND THEN TWEAKED TEMPERATURES FROM THERE. WIND CHILLS TONIGHT SUGGEST THE NEED FOR ANOTHER WIND CHILL ADVISORY FOR AREAS NORTH OF I80. WILL DEFER TO THE DAY TO SHIFT TO DECIDE TO ISSUE THIS AS THERE IS ALREADY ONE OUT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 307 AM CST FRI FEB 27 2015 TWO STORM SYSTEMS WILL IMPACT THE EXTENDED FORECAST...AND BOTH CONTAIN POTENTIAL WINTER IMPACTS. AT THIS TIME...BOTH SYSTEMS ARE RELATIVELY POOR IN CONFIDENCE OF EXACT DETAILS CONCERNING THESE IMPACTS. TO BEGIN THE EXTENDED...HIGH PRESSURE WILL BE MOVING OFF TO THE EAST SATURDAY...AND WITH A VERY COLD START TO THE DAY...THE WEAK WAA WILL LIKELY ONLY RESULT IN HIGHS IN THE MID TEENS NORTH TO MID 20S SOUTH...DESPITE A HEALTHY AMOUNT OF LATE FEBRUARY SUNSHINE IN THE MORNING. WARM ADVECTION BY AFTERNOON...WILL BRING MID LEVEL MOISTURE NORTHWARD...WITH SOME MODELS CONTINUING TO BRUSH OUR SOUTHWEST WITH DEEPER SATURATION BY LATE AFTERNOON. THE MODEL BLEND SHOWS FAR MORE SIGNIFICANT MOISTURE ADVECTION BY SATURDAY NIGHT...AND I WILL CONTINUE TO HIGHLIGHT THAT PERIOD THROUGH SUNDAY WITH HIGH POPS. THIS EVENT IS GOING TO BE ALL SNOW...AND SHOULD HAVE RATIOS IN THE 12 TO 15 TO 1 RANGE...THUS AMOUNTS FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON SHOULD RANGE FROM AROUND 1 INCH NORTHWEST...TO 2 TO 3 INCHES FROM IOWA CITY THROUGH THE QUAD CITIES TO STERLING...TO 3 TO 5 INCHES OVER FAR SOUTHEAST IOWA NORTHEAST MISSOURI TO NEAR PRINCETON ILLINOIS. WHILE THOSE AMOUNTS ARE SUPPORTED BY THE MOST LIKELY BLEND OF GUIDANCE THAT IS INDICATED AT THIS TIME...I AM NOT CONFIDENT IN THEM YET. THE EVENT IS LIKELY GOING TO FALL INTO THE ADVISORY RANGE...ESPECIALLY DUE TO THE LONGER THAN NORMAL DURATION FOR THESE RANGE OF AMOUNTS. LOOKING AT UNCERTAINTY...THE CANADIAN MODEL IS FARTHER SOUTH THAN THE ECMWF AND GFS...AND KEEPS THE NORTHERN 3/4S OF THE CWA DRY...THUS ANOTHER REASON FOR HOLDING OFF ON ANY EARLY HEADLINE AT THIS TIME. THE 06Z NAM...THROUGH 12Z SUNDAY...ALSO KEEPS THE BULK OF MOISTURE AND FORCING SOUTH. MONDAY WILL BE A BREAK BETWEEN LOW CONFIDENCE SYSTEM...AS THE DEEP WESTERN TROF BECOMES EVEN MORE AMPLIFIED. THE MODELS HAVE SHOWN VERY LITTLE CONSISTENCY OVER THE PAST FEW DAYS AND THROUGH TONIGHT WITH RESPECT TO THE LOW TRACK...UPPER ENERGY TRACK...AND BAROCLINICITY OF THIS POTENTIAL SYSTEM. ONE FEATURE THAT HAS BEEN SHOWN CONSISTENTLY...HAS BEEN MOISTURE...WITH A SYNOPTIC SIGNAL OF AN OPEN GULF OF MEXICO...AND EVEN OPEN CARIBBEAN. THE HIGH AMOUNTS OF AVAILABLE MOISTURE ARE REASONS SUPPORTING LIKELY POPS MONDAY NIGHT AND TUESDAY. WHILE NOT CONFIDENT IN THERMAL TRANSITION TIMING...IT IS A BEST MODEL BLEND...AND CONCEPTUAL MODEL FIT FOR PCPN TO BEGIN AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN MONDAY NIGHT...TRANSITIONING TO RAIN TUESDAY...THEN BACK TO SNOW AGAIN TUESDAY NIGHT. THIS WET MESS COULD BE HIGH IMPACT...OR COULD BE LARGELY BENIGN. IT IS VERY DIFFICULT TO TELL...AND WILL KEEP A HEALTHY DOSE OF UNCERTAINTY IN OUR PRODUCTS. FOLLOWING THIS SYSTEM...COLDER DRY WEATHER SETTLES BACK IN THE A FEW DAYS BEFORE MODERATION LOOKS TO OCCUR IN ZONAL FLOW. ERVIN && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1134 PM CST THU FEB 26 2015 CLEAR SKIES AND LIGHT NORTHWEST TO WEST WINDS WILL CONTINUE OVERNIGHT THROUGH FRIDAY KEEPING VFR CONDITIONS IN PLACE. ARCTIC HIGH PRESSURE MOVING THROUGH THE REGION WILL RESULT IN BITTER COLD TEMPERATURES. && .CLIMATE... ISSUED AT 307 AM CST FRI FEB 27 2015 COULD SEE RECORD LOWS THIS MORNING AT A FEW SITES AND POSSIBLY AGAIN TONIGHT AT OTHER SITES. HERE ARE THE RECORDS FOR TONIGHT. RECORD LOWS FOR FEBRUARY 28... MOLINE.........-9 IN 1962 CEDAR RAPIDS...-17 IN 1962 DUBUQUE........-10 IN 1962 BURLINGTON.....-7 IN 1962 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON- BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA- IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BUREAU- CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH- MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK- SCOTLAND. && $$ SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...ERVIN AVIATION...SHEETS CLIMATE...GIBBS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
558 PM CST SAT FEB 28 2015 ...UPDATE TO AVIATION... .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 341 PM CST SAT FEB 28 2015 AS WE REMAIN IN THIS BROAD, CYCLONICALLY-CURVED FLOW PATTERN, WE WILL CONTINUE TO SEE THE TREND OF MINOR SHORTWAVE PERTURBATIONS ROTATING ACROSS SOUTHWESTERN KANSAS...PROVIDING US WITH CHANCES FOR LIGHT PRECIPITATION AS WE SEE SUBTLE DEFORMATION/CONVERGENCE IN THE LOWER-MID TROPOSPHERE ALONG THE BAROCLINIC ZONE. THE NEXT IN THE SERIES WILL BE TONIGHT AFTER THE BREAK WE HAD THIS AFTERNOON. POPS WILL BE INCREASED BACK UP IN TO THE LIKELY CATEGORY WITH A CONTINUATION OF THE WINTER WEATHER ADVISORY. THE VERY LATEST 18Z RUNS OF THE NAM12 AND THE HRRR/RAP HAVE THROWN A LITTLE WRINKLE IN THE NEAR TERM FORECAST. THE NAM12 SUGGESTS THE NEXT LIGHT PRECIPITATION EVENT WILL START ABOUT 6 HOURS SOONER THAN PREVIOUSLY THOUGHT (WHICH IS SIGNIFICANT AT THIS CLOSE OF A TIME RANGE) WHEREAS THE RAP AND HRRR REALLY SHOW NOTHING MUCH AT ALL. IT REALLY IS A FINE LINE BETWEEN NO PRECIP AT ALL AND LIGHT ACCUMULATING PRECIP IN THIS FLOW REGIME, AS MUCH DOWNSLOPE AS THERE IS (YET MOIST). THE SHORT TERM MODELS SHOW A WARMING OF THE 850-750MB LAYER TO THE POINT THAT A SLIGHT WARM NOSE ABOVE 0C WILL DEVELOP. THIS WILL FAVOR SLEET AS A PRECIPITATION TYPE LATE TONIGHT, PARTICULARLY SOUTH OF THE ARKANSAS RIVER. IT SHOULD BE NOTED THAT, AGAIN, ANY PRECIPITATION TONIGHT WOULD BE QUITE LIGHT AND MAY NOT EVEN HAPPEN AT ALL. THE INCOMING SWING SHIFT WILL NEED TO WATCH TRENDS TO SEE OF THE WINTER WX ADVISORY IS STILL NEED THROUGH THE OVERNIGHT HOURS AND IN TO THE MORNING SUNDAY. TEMPERATURES OVERNIGHT WILL REMAIN QUASI-STEADY AROUND 20 DEGREES WITH THE CONTINUED SOUTH WINDS AND CLOUDS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 214 PM CST SAT FEB 28 2015 A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO MONDAY NIGHT REACHING TO THE MID TO UPPER 30S. MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON. THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 555 PM CST SAT FEB 28 2015 MVFR CIGS WILL PREVAIL AT ALL TAF SITES THROUGH MID EVENING AS LOW LEVEL STRATUS PERSISTS ACROSS CENTRAL AND SOUTHWEST KANSAS. THE STRATUS IS EXPECTED TO LOWER SOMEWHAT LATE TONIGHT AS ANOTHER ROUND OF SNOW, POSSIBLY MIXED WITH SLEET EAST OF KGCK, DEVELOPS OVERNIGHT ACROSS PORTIONS OF SOUTHWEST AND CENTRAL KANSAS. AS A RESULT, IFR CIGS/VSBYS WILL BE POSSIBLE IN THE VICINITY OF KGCK AND KDDC GENERALLY AFTER 03Z. KHYS COULD SEE IFR CIGS TOWARD DAYBREAK SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... DDC 18 31 20 38 / 70 60 20 20 GCK 17 31 19 40 / 60 30 20 20 EHA 21 33 21 45 / 30 20 30 20 LBL 21 34 22 43 / 50 30 20 10 HYS 14 35 21 39 / 40 30 20 20 P28 20 32 22 39 / 60 60 10 30 && .DDC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR KSZ046-064>066- 076>081-086>090. && $$ SHORT TERM...UMSCHEID LONG TERM...HOVORKA_42 AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1036 AM MST FRI FEB 27 2015 .UPDATE... ISSUED AT 842 AM MST FRI FEB 27 2015 UPDATED THE FORECASTS TO REMOVE THE WIND CHILL ADVISORY ACROSS KIT CARSON AND CHEYENNE COUNTIES AS WIND CHILL READINGS WILL GRADUALLY RISE THE REST OF TODAY. OTHERWISE...LIGHT SNOW CONTINUES OVER THE AREA. 12Z NAM SHOWS SNOW WILL DECREASE FROM NORTH TO SOUTH AFTER 18Z...THEN NEXT SHORT WAVE TROUGH WILL MOVE ACROSS SOUTHWEST KANSAS TONIGHT BRINGING ANOTHER GOOD CHANCE OF SNOW...ESPECIALLY SOUTH OF INTERSTATE 70. && .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 323 AM MST FRI FEB 27 2015 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH MOVING INTO NEBRASKA. MOISTURE PLUME EXTENDS ACROSS WESTERN KANSAS AND EASTERN COLORADO. AT THE SURFACE 1038 MB HIGH PRESSURE IS CENTERED OVER THE MISSOURI RIVER VALLEY NEAR THE NEBRASKA AND IOWA STATE LINE. SOUTHEASTERLY FLOW IS IN PLACE ACROSS THE CWA WITH A TIGHT TD GRADIENT FROM THE WEST (AROUND 10F) TO THE NORTHEAST (-2F). REGARDING WIND CHILL ADVISORY THIS MORNING AND THE POSSIBILITY TONIGHT...WINDS ARE STILL EXPECTED TO INCREASE IN THE 12-15Z TIME PERIOD THIS MORNING. BASED ON CURRENT WIND FORECAST...IF TEMPS IN THE ADVISED AREA WERE TO DROP TO AROUND 4F OR LOWER WINDS WOULD SUPPORT -15F WIND CHILLS. SHORT RANGE GUIDANCE GENERALLY KEEPS TEMPS STEADY IN THE WEST WHERE THE HIGHER WINDS WILL BE AND WIND CHILLS IN THE -10F OR WARMER RANGE. AT THIS POINT I SEE NO REASON TO CHANGE ADVISORY CONSIDERING HOW CLOSE IT WILL BE. CONDITIONS TONIGHT/EARLY SATURDAY MORNING COULD BE SIMILAR AS THIS MORNING...WITH CLOUD COVER THE LIMITING FACTOR ON IDEAL RADIATIONAL CONDITIONS. IT COULD BE CLOSE TO ADVISORY CRITERIA...BUT WITH THE AMOUNT OF UNCERTAINTY AND ONGOING ADVISORY THIS MORNING I PREFER TO LET THE CURRENT ONE PLAY OUT. TODAY...LIGHT SNOW HAS BEEN REPORTED ACROSS EASTERN COLORADO AND PARTS OF NW KANSAS EARLY THIS MORNING...WITH LIGHT ACCUMULATIONS APPARENT ON WEB CAMS AND OBSERVED AT WFO. SHORT RANGE GUIDANCE SHOWS THIS ACTIVITY CONTINUING TO TRANSITION SOUTHEAST ACROSS THE REGION AS SHORTWAVE SLIDES EAST. CONSIDERING THE LIGHT NATURE OF THE RADAR RETURNS ACROSS THE CWA IT IS HARD TO JUDGE HOW MUCH ACCUMULATION IS ACTUALLY OCCURRING AND TREND IN GUIDANCE HAS BE TOWARDS LOWER VALUES. MAIN THREAT FOR MEANINGFUL ACCUMULATIONS WILL BE BEFORE 18Z...WITH CHANCE FOR MEASURABLE SNOW DIMINISHING AFTERWARDS. IT APPEARS 1-2" SHOULD STILL BE THE HIGH END OF ACCUMULATION FROM NOW THROUGH MIDDAY (MAINLY ALONG AND SOUTH OF I-70). AS WINDS INCREASE WE COULD STILL SEE BLOWING SNOW DEVELOP...HOWEVER THIS SHOULD BE AN ISOLATED THREAT AND TIED TO ANY NEW SNOWFALL RATHER THAN OLD/CRUSTED OVER SNOW PACK. I KEPT PATCHY BLOWING SNOW MENTION AND DO NOT THINK THERE IS A NEED FOR ADVISORY AS VIS RESTRICTIONS FROM BLOWING SNOW WILL BE ISOLATED. TONIGHT-SUNDAY NIGHT...H3 JET BEGINS TO TRANSITION NORTHWARD OVER THE CWA AS TROUGH DEEPENS ACROSS THE SW US. RESULT WITH BE BROAD AREA OF WEAK FORCING DEVELOPING ACROSS THE CWA...WITH BETTER FORCING TIED TO MID LEVEL CIRCULATIONS ROTATING THROUGH THE MEAN FLOW. GUIDANCE HAS TRENDED TOWARDS BETTER PRECIP SIGNALS EITHER WELL WEST OF THE CWA...OR SOUTHEAST OF THE CWA. WE COULD STILL SEE LIGHT ACCUMULATIONS...HOWEVER BEST CHANCE SEEMS TO BE IN OUR EASTERN/SOUTHEAST CWA AND AMOUNTS HAVE TRENDED LOWER WITH 1-2" ON THE HIGHER END OF TOTAL ACCUMULATIONS SATURDAY/SATURDAY NIGHT. CONSIDERING THE TRENDS AND AMOUNT OF UNCERTAINTY I TRENDED POPS LOWER THROUGH ALL THESE PERIODS AND ADJUSTED HIGHEST POPS TO BE IN THE EASTERN CWA SATURDAY AFTERNOON/EVENING CORRELATING WITH BEST PRECIP SIGNAL. REGARDING TEMPS...AS HAS BEEN THE CASE WE SHOULD SEE BELOW NORMAL TEMPERATURES CONTINUE WITH ONLY SLOW MODERATION TO TEMPS ALOFT SATURDAY/SUNDAY AS SW FLOW ALOFT DEVELOPS ACROSS THE SOUTHERN PLANS OVER THE TOP OF THE PERSISTENT ARCTIC AIR MASS. CLOUD COVER AND THE POSSIBILITY OF PRECIP CONTINUES TO COMPLICATE DAYTIME/NIGHTTIME TEMPS...SO ONLY MADE MINOR ADJUSTMENTS TO REFLECT CURRENT CONSENSUS/MODEL TRENDS. LITTLE CHANGE FROM PREVIOUS FORECAST. .LONG TERM...(MONDAY THROUGH THURSDAY NIGHT) ISSUED AT 323 AM MST FRI FEB 27 2015 MODELS HAVE THE JET POSITIONED SLIGHTLY FURTHER NORTH DURING THE FIRST PART OF NEXT WEEK WHICH MAY END UP KEEPING TEMPERATURES SLIGHTLY WARMER AND WILL LIKELY ALSO MOVE THE JET ENHANCED AREA OF PRECIPITATION FURTHER NORTH ACROSS THE FORECAST AREA. MODELS ARE ENDING PRECIPITATION ACROSS THE FORECAST AREA WEDNESDAY MORNING AND HAVE DRY CONDITIONS AFTER THAT. THE UPPER LOW CENTER THAT STARTS OUT AS A CLOSED LOW OVER OVER SOUTHERN CALIFORNIA ON SUNDAY EJECTS OUT ACROSS THE SOUTHERN ROCKIES AND CENTRAL HIGH PLAINS REGION AS AN OPEN WAVE ON MONDAY NIGHT/EARLY TUESDAY. THIS IS AHEAD OF A SHORT WAVE TROUGH DROPPING INTO THE BASE OF THE MAIN TROUGH AXIS OVER BAJA AND ANOTHER LOW IN PHASE WITH THE MAIN UPPER TROUGH THAT BEGINS MOVING FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. THE ENTIRE MAJOR TROUGH AXIS SWEEPS EAST OF THE ROCKIES AND ACROSS THE PLAINS WEDNESDAY EVENING WITH NORTHWEST FLOW AND RIDGING TO EXTEND ACROSS THE ROCKIES INTO THE HIGH PLAINS REGION BY THURSDAY AND THURSDAY NIGHT. A SURFACE LOW AND COLD FRONT ASSOCIATED WITH THE UPPER SHORT WAVE TROUGH LIFTING ACROSS THE REGION ON TUESDAY USHERS IN COOLER TEMPERATURES ACROSS FORECAST AREA AND SPREADS THE PRECIPITATION SOUTHWARD ACROSS THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY MORNING. SNOW WILL COME TO AN END ON WEDNESDAY WITH MUCH COLDER TEMPERATURES AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. THE COLD AIR SHOULD NOT LAST LONG AS RETURN FLOW AROUND THE EXITING HIGH PRESSURE AREA TURNS SOUTHWESTERLY ACROSS THE FORECAST AREA AND THE RIDGE ALOFT BUILDS IN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1032 AM MST FRI FEB 27 2015 LIGHT SNOW CONTINUES AT KGLD...AND RADAR IMAGERY INDICATES THE SNOW WILL CONTINUE A FEW MORE HOURS. VFR CONDITIONS ARE REPORTED AT KMCK...BUT LIGHT SNOW IS JUST TO THE WEST. BASED ON SHORT RANGE MODELS...ENDED THE SNOW AT KGLD/KMCK AFTER 21Z. SNOW WILL REDEVELOP AFTER 09Z WHEN THE NEXT SHORTWAVE TROUGH MOVES ACROSS THE AREA. FOR THE NEXT 12 HOURS...CONDITIONS WILL BE MOSTLY MVFR DUE CEILINGS AND PERIODS OF LIGHT SNOW...THEN DROPPING TO IFR LATER TONIGHT DUE TO A BETTER CHANCE OF SNOW. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...MENTZER SHORT TERM...DR LONG TERM...99 AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
842 AM MST FRI FEB 27 2015 .UPDATE... ISSUED AT 842 AM MST FRI FEB 27 2015 UPDATED THE FORECASTS TO REMOVE THE WIND CHILL ADVISORY ACROSS KIT CARSON AND CHEYENNE COUNTIES AS WIND CHILL READINGS WILL GRADUALLY RISE THE REST OF TODAY. OTHERWISE...LIGHT SNOW CONTINUES OVER THE AREA. 12Z NAM SHOWS SNOW WILL DECREASE FROM NORTH TO SOUTH AFTER 18Z...THEN NEXT SHORT WAVE TROUGH WILL MOVE ACROSS SOUTHWEST KANSAS TONIGHT BRINGING ANOTHER GOOD CHANCE OF SNOW...ESPECIALLY SOUTH OF INTERSTATE 70. && .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 323 AM MST FRI FEB 27 2015 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH MOVING INTO NEBRASKA. MOISTURE PLUME EXTENDS ACROSS WESTERN KANSAS AND EASTERN COLORADO. AT THE SURFACE 1038 MB HIGH PRESSURE IS CENTERED OVER THE MISSOURI RIVER VALLEY NEAR THE NEBRASKA AND IOWA STATE LINE. SOUTHEASTERLY FLOW IS IN PLACE ACROSS THE CWA WITH A TIGHT TD GRADIENT FROM THE WEST (AROUND 10F) TO THE NORTHEAST (-2F). REGARDING WIND CHILL ADVISORY THIS MORNING AND THE POSSIBILITY TONIGHT...WINDS ARE STILL EXPECTED TO INCREASE IN THE 12-15Z TIME PERIOD THIS MORNING. BASED ON CURRENT WIND FORECAST...IF TEMPS IN THE ADVISED AREA WERE TO DROP TO AROUND 4F OR LOWER WINDS WOULD SUPPORT -15F WIND CHILLS. SHORT RANGE GUIDANCE GENERALLY KEEPS TEMPS STEADY IN THE WEST WHERE THE HIGHER WINDS WILL BE AND WIND CHILLS IN THE -10F OR WARMER RANGE. AT THIS POINT I SEE NO REASON TO CHANGE ADVISORY CONSIDERING HOW CLOSE IT WILL BE. CONDITIONS TONIGHT/EARLY SATURDAY MORNING COULD BE SIMILAR AS THIS MORNING...WITH CLOUD COVER THE LIMITING FACTOR ON IDEAL RADIATIONAL CONDITIONS. IT COULD BE CLOSE TO ADVISORY CRITERIA...BUT WITH THE AMOUNT OF UNCERTAINTY AND ONGOING ADVISORY THIS MORNING I PREFER TO LET THE CURRENT ONE PLAY OUT. TODAY...LIGHT SNOW HAS BEEN REPORTED ACROSS EASTERN COLORADO AND PARTS OF NW KANSAS EARLY THIS MORNING...WITH LIGHT ACCUMULATIONS APPARENT ON WEB CAMS AND OBSERVED AT WFO. SHORT RANGE GUIDANCE SHOWS THIS ACTIVITY CONTINUING TO TRANSITION SOUTHEAST ACROSS THE REGION AS SHORTWAVE SLIDES EAST. CONSIDERING THE LIGHT NATURE OF THE RADAR RETURNS ACROSS THE CWA IT IS HARD TO JUDGE HOW MUCH ACCUMULATION IS ACTUALLY OCCURRING AND TREND IN GUIDANCE HAS BE TOWARDS LOWER VALUES. MAIN THREAT FOR MEANINGFUL ACCUMULATIONS WILL BE BEFORE 18Z...WITH CHANCE FOR MEASURABLE SNOW DIMINISHING AFTERWARDS. IT APPEARS 1-2" SHOULD STILL BE THE HIGH END OF ACCUMULATION FROM NOW THROUGH MIDDAY (MAINLY ALONG AND SOUTH OF I-70). AS WINDS INCREASE WE COULD STILL SEE BLOWING SNOW DEVELOP...HOWEVER THIS SHOULD BE AN ISOLATED THREAT AND TIED TO ANY NEW SNOWFALL RATHER THAN OLD/CRUSTED OVER SNOW PACK. I KEPT PATCHY BLOWING SNOW MENTION AND DO NOT THINK THERE IS A NEED FOR ADVISORY AS VIS RESTRICTIONS FROM BLOWING SNOW WILL BE ISOLATED. TONIGHT-SUNDAY NIGHT...H3 JET BEGINS TO TRANSITION NORTHWARD OVER THE CWA AS TROUGH DEEPENS ACROSS THE SW US. RESULT WITH BE BROAD AREA OF WEAK FORCING DEVELOPING ACROSS THE CWA...WITH BETTER FORCING TIED TO MID LEVEL CIRCULATIONS ROTATING THROUGH THE MEAN FLOW. GUIDANCE HAS TRENDED TOWARDS BETTER PRECIP SIGNALS EITHER WELL WEST OF THE CWA...OR SOUTHEAST OF THE CWA. WE COULD STILL SEE LIGHT ACCUMULATIONS...HOWEVER BEST CHANCE SEEMS TO BE IN OUR EASTERN/SOUTHEAST CWA AND AMOUNTS HAVE TRENDED LOWER WITH 1-2" ON THE HIGHER END OF TOTAL ACCUMULATIONS SATURDAY/SATURDAY NIGHT. CONSIDERING THE TRENDS AND AMOUNT OF UNCERTAINTY I TRENDED POPS LOWER THROUGH ALL THESE PERIODS AND ADJUSTED HIGHEST POPS TO BE IN THE EASTERN CWA SATURDAY AFTERNOON/EVENING CORRELATING WITH BEST PRECIP SIGNAL. REGARDING TEMPS...AS HAS BEEN THE CASE WE SHOULD SEE BELOW NORMAL TEMPERATURES CONTINUE WITH ONLY SLOW MODERATION TO TEMPS ALOFT SATURDAY/SUNDAY AS SW FLOW ALOFT DEVELOPS ACROSS THE SOUTHERN PLANS OVER THE TOP OF THE PERSISTENT ARCTIC AIR MASS. CLOUD COVER AND THE POSSIBILITY OF PRECIP CONTINUES TO COMPLICATE DAYTIME/NIGHTTIME TEMPS...SO ONLY MADE MINOR ADJUSTMENTS TO REFLECT CURRENT CONSENSUS/MODEL TRENDS. LITTLE CHANGE FROM PREVIOUS FORECAST. .LONG TERM...(MONDAY THROUGH THURSDAY NIGHT) ISSUED AT 323 AM MST FRI FEB 27 2015 MODELS HAVE THE JET POSITIONED SLIGHTLY FURTHER NORTH DURING THE FIRST PART OF NEXT WEEK WHICH MAY END UP KEEPING TEMPERATURES SLIGHTLY WARMER AND WILL LIKELY ALSO MOVE THE JET ENHANCED AREA OF PRECIPITATION FURTHER NORTH ACROSS THE FORECAST AREA. MODELS ARE ENDING PRECIPITATION ACROSS THE FORECAST AREA WEDNESDAY MORNING AND HAVE DRY CONDITIONS AFTER THAT. THE UPPER LOW CENTER THAT STARTS OUT AS A CLOSED LOW OVER OVER SOUTHERN CALIFORNIA ON SUNDAY EJECTS OUT ACROSS THE SOUTHERN ROCKIES AND CENTRAL HIGH PLAINS REGION AS AN OPEN WAVE ON MONDAY NIGHT/EARLY TUESDAY. THIS IS AHEAD OF A SHORT WAVE TROUGH DROPPING INTO THE BASE OF THE MAIN TROUGH AXIS OVER BAJA AND ANOTHER LOW IN PHASE WITH THE MAIN UPPER TROUGH THAT BEGINS MOVING FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. THE ENTIRE MAJOR TROUGH AXIS SWEEPS EAST OF THE ROCKIES AND ACROSS THE PLAINS WEDNESDAY EVENING WITH NORTHWEST FLOW AND RIDGING TO EXTEND ACROSS THE ROCKIES INTO THE HIGH PLAINS REGION BY THURSDAY AND THURSDAY NIGHT. A SURFACE LOW AND COLD FRONT ASSOCIATED WITH THE UPPER SHORT WAVE TROUGH LIFTING ACROSS THE REGION ON TUESDAY USHERS IN COOLER TEMPERATURES ACROSS FORECAST AREA AND SPREADS THE PRECIPITATION SOUTHWARD ACROSS THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY MORNING. SNOW WILL COME TO AN END ON WEDNESDAY WITH MUCH COLDER TEMPERATURES AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. THE COLD AIR SHOULD NOT LAST LONG AS RETURN FLOW AROUND THE EXITING HIGH PRESSURE AREA TURNS SOUTHWESTERLY ACROSS THE FORECAST AREA AND THE RIDGE ALOFT BUILDS IN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 428 AM MST FRI FEB 27 2015 LIGHT SNOW IS CONTINUING TO IMPACT THE KGLD TERMINAL WITH IFR VIS AND MVFR CIGS. VFR CONDITIONS SHOULD CONTINUE THROUGH THE DAYTIME PERIOD AT KMCK. CONDITIONS COULD VARY THIS MORNING AT KGLD THOUGH IMPROVEMENT ABOVE IFR ISNT LIKELY UNTIL LATER THIS MORNING AS LONG AS LIGHT SNOW LINGERS. AS WINDS INCREASE DURING THE DAY BLOWING SNOW MAY BE POSSIBLE...HOWEVER CONFIDENCE IN REDUCED VIS DUE TO THIS IS TOO LOW TO ADD MENTION DURING THIS UPDATE. MVFR CIGS SHOULD CONTINUE THIS AFTERNOON/EVENING AT KGLD BASED ON TRENDS IN GUIDANCE...THOUGH THERE COULD BE BREAKS IN STRATUS ALLOWING FOR BRIEF PERIODS OF VFR CONDITIONS. LOW LEVEL MOISTURE RETURN WILL RESULT IN IFR CIGS DEVELOPING LATE TONIGHT AND MVFR DEVELOPING AT KMCK LATE TONIGHT. WINDS SHOULD LIMIT LOW LEVEL SATURATION...HOWEVER ADVECTION FOG CANNOT BE COMPLETELY RULE OUT. LIGHT SNOW MAY ALSO REDEVELOP...THOUGH BETTER CHANCE APPEAR TO REMAIN SOUTH AND EAST OF BOTH KGLD AND KMCK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...MENTZER SHORT TERM...DR LONG TERM...99 AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
428 AM MST FRI FEB 27 2015 .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 323 AM MST FRI FEB 27 2015 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH MOVING INTO NEBRASKA. MOISTURE PLUME EXTENDS ACROSS WESTERN KANSAS AND EASTERN COLORADO. AT THE SURFACE 1038 MB HIGH PRESSURE IS CENTERED OVER THE MISSOURI RIVER VALLEY NEAR THE NEBRASKA AND IOWA STATE LINE. SOUTHEASTERLY FLOW IS IN PLACE ACROSS THE CWA WITH A TIGHT TD GRADIENT FROM THE WEST (AROUND 10F) TO THE NORTHEAST (-2F). REGARDING WIND CHILL ADVISORY THIS MORNING AND THE POSSIBILITY TONIGHT...WINDS ARE STILL EXPECTED TO INCREASE IN THE 12-15Z TIME PERIOD THIS MORNING. BASED ON CURRENT WIND FORECAST...IF TEMPS IN THE ADVISED AREA WERE TO DROP TO AROUND 4F OR LOWER WINDS WOULD SUPPORT -15F WIND CHILLS. SHORT RANGE GUIDANCE GENERALLY KEEPS TEMPS STEADY IN THE WEST WHERE THE HIGHER WINDS WILL BE AND WIND CHILLS IN THE -10F OR WARMER RANGE. AT THIS POINT I SEE NO REASON TO CHANGE ADVISORY CONSIDERING HOW CLOSE IT WILL BE. CONDITIONS TONIGHT/EARLY SATURDAY MORNING COULD BE SIMILAR AS THIS MORNING...WITH CLOUD COVER THE LIMITING FACTOR ON IDEAL RADIATIONAL CONDITIONS. IT COULD BE CLOSE TO ADVISORY CRITERIA...BUT WITH THE AMOUNT OF UNCERTAINTY AND ONGOING ADVISORY THIS MORNING I PREFER TO LET THE CURRENT ONE PLAY OUT. TODAY...LIGHT SNOW HAS BEEN REPORTED ACROSS EASTERN COLORADO AND PARTS OF NW KANSAS EARLY THIS MORNING...WITH LIGHT ACCUMULATIONS APPARENT ON WEB CAMS AND OBSERVED AT WFO. SHORT RANGE GUIDANCE SHOWS THIS ACTIVITY CONTINUING TO TRANSITION SOUTHEAST ACROSS THE REGION AS SHORTWAVE SLIDES EAST. CONSIDERING THE LIGHT NATURE OF THE RADAR RETURNS ACROSS THE CWA IT IS HARD TO JUDGE HOW MUCH ACCUMULATION IS ACTUALLY OCCURRING AND TREND IN GUIDANCE HAS BE TOWARDS LOWER VALUES. MAIN THREAT FOR MEANINGFUL ACCUMULATIONS WILL BE BEFORE 18Z...WITH CHANCE FOR MEASURABLE SNOW DIMINISHING AFTERWARDS. IT APPEARS 1-2" SHOULD STILL BE THE HIGH END OF ACCUMULATION FROM NOW THROUGH MIDDAY (MAINLY ALONG AND SOUTH OF I-70). AS WINDS INCREASE WE COULD STILL SEE BLOWING SNOW DEVELOP...HOWEVER THIS SHOULD BE AN ISOLATED THREAT AND TIED TO ANY NEW SNOWFALL RATHER THAN OLD/CRUSTED OVER SNOW PACK. I KEPT PATCHY BLOWING SNOW MENTION AND DO NOT THINK THERE IS A NEED FOR ADVISORY AS VIS RESTRICTIONS FROM BLOWING SNOW WILL BE ISOLATED. TONIGHT-SUNDAY NIGHT...H3 JET BEGINS TO TRANSITION NORTHWARD OVER THE CWA AS TROUGH DEEPENS ACROSS THE SW US. RESULT WITH BE BROAD AREA OF WEAK FORCING DEVELOPING ACROSS THE CWA...WITH BETTER FORCING TIED TO MID LEVEL CIRCULATIONS ROTATING THROUGH THE MEAN FLOW. GUIDANCE HAS TRENDED TOWARDS BETTER PRECIP SIGNALS EITHER WELL WEST OF THE CWA...OR SOUTHEAST OF THE CWA. WE COULD STILL SEE LIGHT ACCUMULATIONS...HOWEVER BEST CHANCE SEEMS TO BE IN OUR EASTERN/SOUTHEAST CWA AND AMOUNTS HAVE TRENDED LOWER WITH 1-2" ON THE HIGHER END OF TOTAL ACCUMULATIONS SATURDAY/SATURDAY NIGHT. CONSIDERING THE TRENDS AND AMOUNT OF UNCERTAINTY I TRENDED POPS LOWER THROUGH ALL THESE PERIODS AND ADJUSTED HIGHEST POPS TO BE IN THE EASTERN CWA SATURDAY AFTERNOON/EVENING CORRELATING WITH BEST PRECIP SIGNAL. REGARDING TEMPS...AS HAS BEEN THE CASE WE SHOULD SEE BELOW NORMAL TEMPERATURES CONTINUE WITH ONLY SLOW MODERATION TO TEMPS ALOFT SATURDAY/SUNDAY AS SW FLOW ALOFT DEVELOPS ACROSS THE SOUTHERN PLANS OVER THE TOP OF THE PERSISTENT ARCTIC AIR MASS. CLOUD COVER AND THE POSSIBILITY OF PRECIP CONTINUES TO COMPLICATE DAYTIME/NIGHTTIME TEMPS...SO ONLY MADE MINOR ADJUSTMENTS TO REFLECT CURRENT CONSENSUS/MODEL TRENDS. LITTLE CHANGE FROM PREVIOUS FORECAST. .LONG TERM...(MONDAY THROUGH THURSDAY NIGHT) ISSUED AT 323 AM MST FRI FEB 27 2015 MODELS HAVE THE JET POSITIONED SLIGHTLY FURTHER NORTH DURING THE FIRST PART OF NEXT WEEK WHICH MAY END UP KEEPING TEMPERATURES SLIGHTLY WARMER AND WILL LIKELY ALSO MOVE THE JET ENHANCED AREA OF PRECIPITATION FURTHER NORTH ACROSS THE FORECAST AREA. MODELS ARE ENDING PRECIPITATION ACROSS THE FORECAST AREA WEDNESDAY MORNING AND HAVE DRY CONDITIONS AFTER THAT. THE UPPER LOW CENTER THAT STARTS OUT AS A CLOSED LOW OVER OVER SOUTHERN CALIFORNIA ON SUNDAY EJECTS OUT ACROSS THE SOUTHERN ROCKIES AND CENTRAL HIGH PLAINS REGION AS AN OPEN WAVE ON MONDAY NIGHT/EARLY TUESDAY. THIS IS AHEAD OF A SHORT WAVE TROUGH DROPPING INTO THE BASE OF THE MAIN TROUGH AXIS OVER BAJA AND ANOTHER LOW IN PHASE WITH THE MAIN UPPER TROUGH THAT BEGINS MOVING FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. THE ENTIRE MAJOR TROUGH AXIS SWEEPS EAST OF THE ROCKIES AND ACROSS THE PLAINS WEDNESDAY EVENING WITH NORTHWEST FLOW AND RIDGING TO EXTEND ACROSS THE ROCKIES INTO THE HIGH PLAINS REGION BY THURSDAY AND THURSDAY NIGHT. A SURFACE LOW AND COLD FRONT ASSOCIATED WITH THE UPPER SHORT WAVE TROUGH LIFTING ACROSS THE REGION ON TUESDAY USHERS IN COOLER TEMPERATURES ACROSS FORECAST AREA AND SPREADS THE PRECIPITATION SOUTHWARD ACROSS THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY MORNING. SNOW WILL COME TO AN END ON WEDNESDAY WITH MUCH COLDER TEMPERATURES AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. THE COLD AIR SHOULD NOT LAST LONG AS RETURN FLOW AROUND THE EXITING HIGH PRESSURE AREA TURNS SOUTHWESTERLY ACROSS THE FORECAST AREA AND THE RIDGE ALOFT BUILDS IN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 428 AM MST FRI FEB 27 2015 LIGHT SNOW IS CONTINUING TO IMPACT THE KGLD TERMINAL WITH IFR VIS AND MVFR CIGS. VFR CONDITIONS SHOULD CONTINUE THROUGH THE DAYTIME PERIOD AT KMCK. CONDITIONS COULD VARY THIS MORNING AT KGLD THOUGH IMPROVEMENT ABOVE IFR ISNT LIKELY UNTIL LATER THIS MORNING AS LONG AS LIGHT SNOW LINGERS. AS WINDS INCREASE DURING THE DAY BLOWING SNOW MAY BE POSSIBLE...HOWEVER CONFIDENCE IN REDUCED VIS DUE TO THIS IS TOO LOW TO ADD MENTION DURING THIS UPDATE. MVFR CIGS SHOULD CONTINUE THIS AFTERNOON/EVENING AT KGLD BASED ON TRENDS IN GUIDANCE...THOUGH THERE COULD BE BREAKS IN STRATUS ALLOWING FOR BRIEF PERIODS OF VFR CONDITIONS. LOW LEVEL MOISTURE RETURN WILL RESULT IN IFR CIGS DEVELOPING LATE TONIGHT AND MVFR DEVELOPING AT KMCK LATE TONIGHT. WINDS SHOULD LIMIT LOW LEVEL SATURATION...HOWEVER ADVECTION FOG CANNOT BE COMPLETELY RULE OUT. LIGHT SNOW MAY ALSO REDEVELOP...THOUGH BETTER CHANCE APPEAR TO REMAIN SOUTH AND EAST OF BOTH KGLD AND KMCK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...WIND CHILL ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ091-092. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
323 AM MST FRI FEB 27 2015 .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 323 AM MST FRI FEB 27 2015 EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH MOVING INTO NEBRASKA. MOISTURE PLUME EXTENDS ACROSS WESTERN KANSAS AND EASTERN COLORADO. AT THE SURFACE 1038 MB HIGH PRESSURE IS CENTERED OVER THE MISSOURI RIVER VALLEY NEAR THE NEBRASKA AND IOWA STATE LINE. SOUTHEASTERLY FLOW IS IN PLACE ACROSS THE CWA WITH A TIGHT TD GRADIENT FROM THE WEST (AROUND 10F) TO THE NORTHEAST (-2F). REGARDING WIND CHILL ADVISORY THIS MORNING AND THE POSSIBILITY TONIGHT...WINDS ARE STILL EXPECTED TO INCREASE IN THE 12-15Z TIME PERIOD THIS MORNING. BASED ON CURRENT WIND FORECAST...IF TEMPS IN THE ADVISED AREA WERE TO DROP TO AROUND 4F OR LOWER WINDS WOULD SUPPORT -15F WIND CHILLS. SHORT RANGE GUIDANCE GENERALLY KEEPS TEMPS STEADY IN THE WEST WHERE THE HIGHER WINDS WILL BE AND WIND CHILLS IN THE -10F OR WARMER RANGE. AT THIS POINT I SEE NO REASON TO CHANGE ADVISORY CONSIDERING HOW CLOSE IT WILL BE. CONDITIONS TONIGHT/EARLY SATURDAY MORNING COULD BE SIMILAR AS THIS MORNING...WITH CLOUD COVER THE LIMITING FACTOR ON IDEAL RADIATIONAL CONDITIONS. IT COULD BE CLOSE TO ADVISORY CRITERIA...BUT WITH THE AMOUNT OF UNCERTAINTY AND ONGOING ADVISORY THIS MORNING I PREFER TO LET THE CURRENT ONE PLAY OUT. TODAY...LIGHT SNOW HAS BEEN REPORTED ACROSS EASTERN COLORADO AND PARTS OF NW KANSAS EARLY THIS MORNING...WITH LIGHT ACCUMULATIONS APPARENT ON WEB CAMS AND OBSERVED AT WFO. SHORT RANGE GUIDANCE SHOWS THIS ACTIVITY CONTINUING TO TRANSITION SOUTHEAST ACROSS THE REGION AS SHORTWAVE SLIDES EAST. CONSIDERING THE LIGHT NATURE OF THE RADAR RETURNS ACROSS THE CWA IT IS HARD TO JUDGE HOW MUCH ACCUMULATION IS ACTUALLY OCCURRING AND TREND IN GUIDANCE HAS BE TOWARDS LOWER VALUES. MAIN THREAT FOR MEANINGFUL ACCUMULATIONS WILL BE BEFORE 18Z...WITH CHANCE FOR MEASURABLE SNOW DIMINISHING AFTERWARDS. IT APPEARS 1-2" SHOULD STILL BE THE HIGH END OF ACCUMULATION FROM NOW THROUGH MIDDAY (MAINLY ALONG AND SOUTH OF I-70). AS WINDS INCREASE WE COULD STILL SEE BLOWING SNOW DEVELOP...HOWEVER THIS SHOULD BE AN ISOLATED THREAT AND TIED TO ANY NEW SNOWFALL RATHER THAN OLD/CRUSTED OVER SNOW PACK. I KEPT PATCHY BLOWING SNOW MENTION AND DO NOT THINK THERE IS A NEED FOR ADVISORY AS VIS RESTRICTIONS FROM BLOWING SNOW WILL BE ISOLATED. TONIGHT-SUNDAY NIGHT...H3 JET BEGINS TO TRANSITION NORTHWARD OVER THE CWA AS TROUGH DEEPENS ACROSS THE SW US. RESULT WITH BE BROAD AREA OF WEAK FORCING DEVELOPING ACROSS THE CWA...WITH BETTER FORCING TIED TO MID LEVEL CIRCULATIONS ROTATING THROUGH THE MEAN FLOW. GUIDANCE HAS TRENDED TOWARDS BETTER PRECIP SIGNALS EITHER WELL WEST OF THE CWA...OR SOUTHEAST OF THE CWA. WE COULD STILL SEE LIGHT ACCUMULATIONS...HOWEVER BEST CHANCE SEEMS TO BE IN OUR EASTERN/SOUTHEAST CWA AND AMOUNTS HAVE TRENDED LOWER WITH 1-2" ON THE HIGHER END OF TOTAL ACCUMULATIONS SATURDAY/SATURDAY NIGHT. CONSIDERING THE TRENDS AND AMOUNT OF UNCERTAINTY I TRENDED POPS LOWER THROUGH ALL THESE PERIODS AND ADJUSTED HIGHEST POPS TO BE IN THE EASTERN CWA SATURDAY AFTERNOON/EVENING CORRELATING WITH BEST PRECIP SIGNAL. REGARDING TEMPS...AS HAS BEEN THE CASE WE SHOULD SEE BELOW NORMAL TEMPERATURES CONTINUE WITH ONLY SLOW MODERATION TO TEMPS ALOFT SATURDAY/SUNDAY AS SW FLOW ALOFT DEVELOPS ACROSS THE SOUTHERN PLANS OVER THE TOP OF THE PERSISTENT ARCTIC AIR MASS. CLOUD COVER AND THE POSSIBILITY OF PRECIP CONTINUES TO COMPLICATE DAYTIME/NIGHTTIME TEMPS...SO ONLY MADE MINOR ADJUSTMENTS TO REFLECT CURRENT CONSENSUS/MODEL TRENDS. LITTLE CHANGE FROM PREVIOUS FORECAST. .LONG TERM...(MONDAY THROUGH THURSDAY NIGHT) ISSUED AT 323 AM MST FRI FEB 27 2015 MODELS HAVE THE JET POSITIONED SLIGHTLY FURTHER NORTH DURING THE FIRST PART OF NEXT WEEK WHICH MAY END UP KEEPING TEMPERATURES SLIGHTLY WARMER AND WILL LIKELY ALSO MOVE THE JET ENHANCED AREA OF PRECIPITATION FURTHER NORTH ACROSS THE FORECAST AREA. MODELS ARE ENDING PRECIPITATION ACROSS THE FORECAST AREA WEDNESDAY MORNING AND HAVE DRY CONDITIONS AFTER THAT. THE UPPER LOW CENTER THAT STARTS OUT AS A CLOSED LOW OVER OVER SOUTHERN CALIFORNIA ON SUNDAY EJECTS OUT ACROSS THE SOUTHERN ROCKIES AND CENTRAL HIGH PLAINS REGION AS AN OPEN WAVE ON MONDAY NIGHT/EARLY TUESDAY. THIS IS AHEAD OF A SHORT WAVE TROUGH DROPPING INTO THE BASE OF THE MAIN TROUGH AXIS OVER BAJA AND ANOTHER LOW IN PHASE WITH THE MAIN UPPER TROUGH THAT BEGINS MOVING FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. THE ENTIRE MAJOR TROUGH AXIS SWEEPS EAST OF THE ROCKIES AND ACROSS THE PLAINS WEDNESDAY EVENING WITH NORTHWEST FLOW AND RIDGING TO EXTEND ACROSS THE ROCKIES INTO THE HIGH PLAINS REGION BY THURSDAY AND THURSDAY NIGHT. A SURFACE LOW AND COLD FRONT ASSOCIATED WITH THE UPPER SHORT WAVE TROUGH LIFTING ACROSS THE REGION ON TUESDAY USHERS IN COOLER TEMPERATURES ACROSS FORECAST AREA AND SPREADS THE PRECIPITATION SOUTHWARD ACROSS THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY MORNING. SNOW WILL COME TO AN END ON WEDNESDAY WITH MUCH COLDER TEMPERATURES AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. THE COLD AIR SHOULD NOT LAST LONG AS RETURN FLOW AROUND THE EXITING HIGH PRESSURE AREA TURNS SOUTHWESTERLY ACROSS THE FORECAST AREA AND THE RIDGE ALOFT BUILDS IN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 958 PM MST THU FEB 26 2015 LATEST RADAR TRENDS INDICATE THAT VFR CONDITIONS SHOULD DETERIORATE TO MVFR AT KGLD OVERNIGHT WITH LIGHT SNOW DEVELOPING. MODELS INDICATE THE SNOW SHOULD TAPER OFF BY MIDDAY BUT MVFR WILL PERSIST. VFR CONDITIONS WILL CONTINUE AT KMCK FOR MOST OF THE NEXT 24 HOURS. HOWEVER, THE FORECAST SOUNDING FOR KMCK SHOWS SOME STRATUS DEVELOPING AND PERSISTING INTO FRIDAY EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...WIND CHILL ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ091-092. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
958 PM EST SAT FEB 28 2015 .UPDATE... ISSUED AT 958 PM EST SAT FEB 28 2015 MADE SOME MORE TWEAKS TO TEMPERATURES. SOME VALLEY LOCATIONS ARE ALREADY DOWN TO 31 DEGREES WITH SEVERAL MORE RIGHT ON THEIR HEELS. DO NOT EXPECT TEMPERATURES TO GET TOO MUCH COLDER AS CLOUDS ARE SPREAD INTO THE REGION AND SHOULD HALT THEIR FALL. HOWEVER...THE QUESTION CONTINUES...WILL THESE TEMPERATURES COME BACK UP PRIOR TO PRECIPITATION ONSET LATE TONIGHT. AS IT APPEARS NOW...THIS MAY BE A STRUGGLE AND THUS...THE FREEZING RAIN THREAT CONTINUES. HRRR HAS BEGUN TO FLUCTUATE ON PRECIPITATION DEVELOPING AROUND DAWN...BUT THE LATEST RUN HAS IT BACK IN THERE. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORY FOR NOW AS STILL NOT CERTAIN HOW MUCH FREEZING RAIN WILL ACTUALLY OCCUR AND WHETHER IT HAS ANY IMPACT AS GROUND TEMPERATURES RECOVERED FAIRLY WELL WITH THE SUNSHINE EARLIER TODAY. OUTSIDE OF SOME TWEAKS TO TEMPERATURES...WILL MAINTAIN THE FORECAST AS IS. UPDATE ISSUED AT 715 PM EST SAT FEB 28 2015 OPTED FOR A SPECIAL WEATHER STATEMENT FOR THE FREEZING RAIN/SLEET/SNOW POTENTIAL LATE TONIGHT. LAST SEVERAL RUNS OF THE HRRR HAVE SHOWN PRETTY GOOD PRECIPITATION DEVELOPMENT AFTER 09Z TONIGHT. WITH THE UNCERTAINTY ON WHETHER TEMPERATURES CAN STAY ABOVE FREEZING...IT CERTAINLY LOOKS LIKE A SETUP FOR SOME FREEZING RAIN. WITH THE DRY AIR IN PLACE...SOME SLEET MAY BE POSSIBLE EARLY ON AS WELL. ANY SNOW POTENTIAL WILL LIKELY STAY TO THE NORTH AS THE WARM NOSE POKES ACROSS THE AREA. TWEAKED TEMPERATURES AND DEWPOINTS THROUGH THE NIGHT AND RE RAN THE WEATHER TO MATCH THE EXPECTED TRANSITION ZONES THROUGH DAYBREAK. WE SHOULD SEE A TRANSITION TO RAIN SHORTLY AFTER DAYBREAK AS ANY REMAINING COLD AIR GETS SCOURED OUT IN THE VALLEYS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 350 PM EST SAT FEB 28 2015 WINDS WILL SHIFT TO A MORE SRLY DIRECTION ON THE BACKSIDE OF EXITING HIGH PRESSURE THIS EVENING...CREATING A PSEUDO WARM FRONTAL BOUNDARY ALONG A DEVELOPING LLVL JET. OVERRUNNING PRECIP WILL THEN DEVELOP BY THIS EVENING IN NORTHERN PORTIONS OF CENTRAL KENTUCKY...INTO INDIANA AS WELL AS OHIO. THIS WILL BRING PRECIP INTO EASTERN KENTUCKY BY OR SHORTLY AFTER 06Z TONIGHT. THERE CONTINUES TO BE A FEW CONCERNS WITH THIS SYSTEM...NAMELY A LIGHT ICE AND SNOW POTENTIAL. LATEST FORECAST SOUNDINGS ARE CONTINUING TO SUPPORT A STEADY OR GRADUAL WARMING OF TEMPS THROUGHOUT THE NIGHT AS SOUTHERLY WINDS... CLOUD COVER...AND PRECIP TAKE CONTROL. HOWEVER...GIVEN THE ANTECEDENT COLD CONDITIONS...IT IS LIKELY THAT EVEN AS SURFACE TEMPS SLOWLY RISE...THE PAVEMENT AND GROUND TEMPS WILL TAKE AN HOUR TO 3 HOURS LONGER. TEMPERATURES IN THE LLVLS WILL RISE ABOVE FREEZING BETWEEN 0 AND 6Z...HOWEVER...SURFACE TEMPS WILL LIKELY LAG BEHIND BY A FEW HOURS. THIS WILL CREATE THE SET UP FOR SOME SNOW/IP POTENTIAL JUST AT ONSET /AND CONTINUING IN THE NORTH FOR A BIT LONGER/...THEN A FREEZING RAIN POTENTIAL GIVEN THE LATEST NAM12 AND GFS40 FORECAST SOUNDINGS THROUGH AROUND 12Z...BEFORE SURFACE TEMPS FINALLY WARM ENOUGH ACROSS THE REGION THAT ALL PRECIP FALLS AS RAIN AFTER 12Z TO 15Z. GIVEN THE WARMER SRLY FLOW TOMORROW...TEMPS WILL FINALLY INCREASE TO CLOSER TO SEASONABLE NORMAL VALUES DURING THE AFTERNOON...GENERALLY IN THE 40S. FROM HERE...FORECAST SOUNDINGS SHOW A DEEP LAYER OF MOISTURE CONTINUING THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS SUNDAY NIGHT WITH SOME CONTINUOUS/WIDESPREAD RAINFALL POSSIBLE. RAIN WILL THEN CHANGE BACK OVER TO SNOW AS TEMPS DROP BELOW FREEZING AFTER DARK...BEFORE FINALLY LOSING INTENSITY AND TAPERING OFF MONDAY MORNING AS HIGH PRESSURE MOVES IN OVERHEAD. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 451 PM EST SAT FEB 28 2015 THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE PATTERN TO RULE ACROSS THE CONUS THROUGH NEXT WEEKEND. A POSITIVELY TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST FLOW TO SETTING UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW FOR A STOUT BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND TENNESSEE VALLEYS THROUGH THE MIDDLE OF THE WEEK...WITH MUCH WARMER AND WETTER AIR BEING ADVECTED INTO THE REGION. THIS WILL BE FOLLOWED BY ANOTHER SHARP COOL DOWN...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW BEFORE ENDING THE WORK WEEK COLD AND DRY. DETAILS ON HOW ALL OF THIS EVOLVES CONTINUES TO BE LOWER CONFIDENCE UNTIL WE GET A LITTLE CLOSER TO THE EVENT...SO HAVE STUCK CLOSE TO A BLEND OF THE SOLUTIONS. IN GENERAL...THE MODELS SEEM TO BE COUPLING THE MOISTURE AND BEST FORCING INITIALLY FURTHER TO THE NORTHWEST...RESULTING IN NOT QUITE AS SIGNIFICANT RAINFALL TOTALS ACROSS EASTERN KENTUCKY FROM TUESDAY THROUGH THURSDAY...WITH GENERALLY 2 TO 3 INCHES FORECAST. STILL...THIS WILL BE MORE THAN ENOUGH TO CAUSE FLOODING CONCERNS AND WILL CONTINUE TO HIGHLIGHT THIS THREAT IN AN ONGOING HYDROLOGIC OUTLOOK. PRECIPITATION MAY START OUT AS A WINTRY MIX LATE MONDAY INTO EARLY TUESDAY MORNING...DEPENDING ON HOW QUICKLY IT CAN COOL DOWN AS WINDS VEER AROUND TO THE SOUTHEAST AND THICKER CLOUDS OVERSPREAD THE AREA ONCE AGAIN. A SURFACE WARM FRONT WILL LIFT THROUGH ON TUESDAY...WITH RAINY CONDITIONS MOVING IN. THE COLD FRONT WILL FOLLOW AND VERY GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...PROVIDING THE BULK OF THE HEAVIER RAINFALL. MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. AFTER ENJOYING HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS WILL FALL BACK INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS BOTTOMING OUT NEAR THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL RETURN TO THE 40S FOR SATURDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 715 PM EST SAT FEB 28 2015 VFR CONDITIONS WILL LAST INTO THE NIGHT. HOWEVER...AS THE LOW LEVEL JET STRENGTHENS OVERNIGHT...BETTER MOISTURE WILL BE TRANSPORTED INTO EASTERN KENTUCKY WITH CIG HEIGHTS LOWERING LATE TONIGHT. SOME MVFR CIGS ARE POSSIBLE BY DAYBREAK. IN ADDITION...SOME SLEET/FREEZING RAIN WILL ALSO BE POSSIBLE AROUND DAYBREAK...BEFORE TRANSITIONING TO ALL RAIN BY MID MORNING. CONFIDENCE ON FORECAST TOMORROW IS NOT HIGH AND THUS...CIG FORECAST REMAINS VERY UNCERTAIN. ITS POSSIBLE SOME MVFR CIGS MAY HOLD ON THROUGH THE DAY...BUT SOUTHERLY FLOW COULD ERODE THESE AWAY THROUGH THE DAY WITH A SLIGHT DOWNSLOPING COMPONENT. REGARDLESS...AT THE VERY LEAST...WE SHOULD SEE A MIX OF VFR/MVFR CONDITIONS. SOME RAIN SHOWERS COULD ALSO PERSIST THROUGH THE DAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JMW LONG TERM...GEOGERIAN AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
341 AM EST FRI FEB 27 2015 .UPDATE... ISSUED AT 103 AM EST FRI FEB 27 2015 CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE A WEAK ARCTIC FRONT MOVING THROUGH THE AREA. ASSOCIATED WITH THE FRONT IS SOME WEAK RETURNS SHOWING SOME FLURRIES AND SNOW SHOWERS. SOME OF THESE SNOW SHOWERS HAVE PRODUCED A DUSTING AT MOST IN SOME AREAS WITH SOME VISIBILITIES NEAR A MILE. THIS BAND HAS A FINE EDGE NOW CROSSING I-64. THIS SHOULD BRING AN END TO THE ACTIVITY INTO THE MORNING HOURS. HAVE SENT OUT SOME FRESHENED UP GRIDS TO ADDRESS THIS AND TEMPERATURES AS THE COLDER AIR IS NOW PUSHING THROUGH THE MIDWEST STATES AND NOW INTO KY. THOUGH NO SIGNIFICANT CHANGE WAS MADE TO THE ZFP...THE GRIDS HAVE BEEN SENT TO THE NDFD SERVERS. UPDATE ISSUED AT 945 PM EST THU FEB 26 2015 A DISTURBANCE IS WORKING THROUGH THE GREAT LAKES AND OH VALLEY REGION AND IS BRINGING SOME VERY LIGHT SNOW OR FLURRIES TO THE REGION. AWOS AND ASOS SITES OVER CENTRAL AND NORTHERN KY HAVE REPORTED SNOW REACHING THE GROUND...BUT THE AIR MASS IS RATHER DRY...SO VISIBILITIES AND CEILINGS HAVE NOT DROPPED ALL THAT FAR. AT THIS POINT...PER RADAR AND SFC OBS IT APPEARS THAT THE LIGHT SNOW OR FLURRIES IS NEARING THE SOMERSET TO JACKSON TO SANDY HOOK LINE. ONLY ONE KY MESONET SITE IN CENTRAL KY HAS RECEIVED MEASURABLE PRECIPITATION WITH THIS. THE NEAR TERM MODELS SUCH AS THE HRRR CONTINUE TO HAVE THIS DIMINISHING AS IT MOVES EAST...BUT IT SEEMS TO CLEARLY BE HOLDING TOGETHER BETTER THAN THE HRRR IS FORECASTING. THE WINDS ARE BIT MORE NORTHERLY THAN IDEAL FOR UPSLOPE ALTHOUGH THERE IS A BIT OF AN UPSLOPE COMPONENT. THE CURRENT FORECAST IS MORE REFLECTIVE OF THE MOST RECENT NAM AND GFS RUNS AS SEEMS MORE REASONABLE GIVEN UPSTREAM TRENDS. AT THIS POINT...SLIGHT CHANCE TO CHANCE POPS APPEAR TO REMAIN IN ORDER AND AN SPS IS ALREADY IN PLACE. SOME LOCATIONS MAY PICK UP A QUARTER TO A HALF OF AN INCH OF FLUFF WHILE OTHER LOCATIONS MAY ONLY GET A LIGHT DUSTING OR NOTHING AT ALL. THE BIGGER STORY WILL BE THE COLDER AIR WORKING INTO THE REGION LATE TONIGHT. LOWS SHOULD REACH THE UPPER SINGLE DIGITS ABOVE ZERO NORTH...WITH UPPER TEENS NEAR THE TN BORDER. TEMPS WILL STRUGGLE TO REACH THE MID TO UPPER 20S IN MANY LOCATIONS ON FRIDAY...ALTHOUGH FRI NIGHT APPEARS TO BE COLDER ON AVERAGE THAN TONIGHT. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 355 PM EST THU FEB 26 2015 19Z SFC ANALYSIS SHOWS LOW PRESSURE PASSING BY TO THE EAST WHILE A DEEP LOW IS APPROACHING FROM THE NORTHWEST. AN ARCTIC COLD FRONT FROM THIS IS MOVING INTO KENTUCKY AND THIS WILL SWEEP ACROSS EASTERN KENTUCKY LATER THIS EVENING. ON REGIONAL RADAR...THE LIGHT SNOW ASSOCIATED WITH THIS BOUNDARY IS STARTING TO SETTLE DEEPER INTO THE STATE. EAST KENTUCKY SAW PARTLY SUNNY SKIES THIS AFTERNOON WITH SOME LOW CLOUDS CLINGING TO OUR FAR EASTERN AREAS WHILE HIGH CLOUDS PASSED THROUGH NORTHERN PARTS OF THE CWA. LOWER CLOUDS ARE INBOUND FROM WESTERN AND CENTRAL KENTUCKY NOW...AHEAD OF THAT FRONT. TEMPERATURES WERE ABLE TO SPIKE UP TO NEAR 40 DEGREES FOR MUCH OF THE AREA THIS AFTERNOON THANKS TO THE PARTIAL SUNSHINE WHILE ONLY LOW 30S WERE ACHIEVED IN THE NORTHWEST. DEWPOINTS REMAIN IN THE TEENS IN THE NORTHWEST WHILE LOWER AND MIDDLE 20S ARE FOUND IN THE EAST. WINDS WERE GENERALLY FROM THE NORTHWEST AT 5 TO 10 MPH WITH GUSTS TO 15 MPH. THE MODELS ARE IN GOOD AGREEMENT ALOFT AS A WEAK WAVE PASSES TO THE SOUTH OF THE AREA THIS EVENING FOLLOWED BY A STRONGER AND LARGER TROUGH THAT SETTLES INTO THE OHIO VALLEY TONIGHT. THIS TROUGH WILL BRING ITS CORE ENERGY ACROSS OHIO DURING THE DAY FRIDAY BEFORE TAPERING OFF AMIDST REBOUNDING HEIGHTS OVER KENTUCKY FRIDAY NIGHT. THE ECMWF IS A BIT QUICKER THAN THE OTHER MODELS WITH THESE HEIGHT RISES AND MAY BE GETTING AHEAD OF ITSELF. GIVEN THE GENERAL AGREEMENT...AT LEAST INTO FRIDAY EVENING...HAVE FAVORED THE HIGHER RESOLUTION MODEL GUIDANCE FROM THE HRRR... RAP13...AND NAM12 FOR WX SPECIFICS. SENSIBLE WEATHER WILL FEATURE CLOUDS ARRIVING ALONG WITH SNOW SHOWERS THIS EVENING AND CONTINUING THROUGH THE NIGHT IN ASSOCIATION WITH THE ARCTIC AIR POURING BACK INTO THIS PART OF THE STATE. TEMPERATURES WILL FALL INTO THE TEENS IN MOST PLACES BY DAWN THANKS TO THE CAA WITH SOME SINGLE DIGITS POSSIBLE NORTH OF INTERSTATE 64. ANY LINGERING SNOW SHOWERS WILL COME TO AN END FRIDAY MORNING IN FAR EASTERN PARTS OF THE AREA WITH SOME SUNSHINE POSSIBLE BY AFTERNOON...BUT TEMPERATURES WILL STILL STRUGGLE TO MAKE IT INTO THE LOWER 20S BY MIDDAY. THIS SETS THE STAGE FOR A VERY CHILLY NIGHT WITH SINGLE DIGITS LIKELY ON TAP FOR THE VALLEYS AND MORE OPEN AREAS...WHILE SOME LATE ARRIVING HIGH CLOUDS AND THE INVERSION MAY SPARE THE RIDGES THE COLDEST OF THE AIR. CANNOT RULE OUT SOME FLURRIES ARRIVING TOWARD DAWN SATURDAY AHEAD OF THE NEXT SYSTEM...BUT HAVE LEFT THEM OUT FOR NOW. AGAIN USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE DAY FRIDAY...WITH SOME TERRAIN BASED ADJUSTMENTS MADE AT NIGHT. AFTER THAT...USED THE SUPERBLEND TO INITIATE THE GRIDS INTO SATURDAY MORNING WITH MINOR CHANGES. AS FOR POPS...ENDED UP ON THE HIGH SIDE...CLOSER TO THE MET...OF RATHER LOW MOS GUIDANCE TONIGHT...THEN SIMILAR FOR THE REST OF THE SHORT TERM. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 340 AM EST FRI FEB 27 2015 A VERY PERIOD IN STORE IN THE EXTENDED. THE PERIOD WILL ACTUALLY START OFF FAIRLY QUIET...AS A WARM FRONTAL BOUNDARY MEANDERS ABOUT ALONG THE OHIO RIVER. SNOW SHOWERS WILL BEGIN TO MOVE INTO THE AREA AS THE WARM FRONT SAGS SOUTH AND INTERACTS WITH BELOW FREEZING AIR THAT WILL ALREADY BE IN PLACE. THE SNOW SHOWERS WILL CHANGE TO RAIN SHOWERS AND QUICKLY OVERSPREAD THE AREA SUNDAY AND SUNDAY NIGHT AS THE COLD FRONT MAKES ITS WAY ACROSS THE AREA AND WARM AIR SURGES NORTH AHEAD OF THE BOUNDARY. THE RAIN COULD BE HEAVY TIMES SUNDAY NIGHT AND MONDAY. ONCE THE INITIAL COLD FRONT EXITS THE AREA LATE IN THE DAY ON MONDAY...A LULL IN THE PRECIPITATION IS EXPECTED...AS A RIDGE OF HIGH PRESSURE IS PROGGED TO SETTLE OVER THE AREA FOR ABOUT 10 HOURS. AFTER THIS SHORT RESPITE...ANOTHER ROUND OF RAIN AND SNOW SHOWERS IS EXPECTED AS A WARM FRONT MOVES ACROSS THE AREA FROM THE SOUTH. THE PRECIPITATION SHOULD CHANGE OVER TO ALL RAIN BY MID MORNING ON TUESDAY...AS WARM GULF AIR PUSHES BACK INTO THE AREA AND OVERRIDES THE WARM FRONT. THE RAIN IS EXPECTED TO BECOME WIDESPREAD DURING THE AFTERNOON AND HOURS ON TUESDAY AND THROUGHOUT THE OVERNIGHT...AS ANOTHER COLD FRONT PUSHES SLOWLY ACROSS THE AREA. THIS ROUND OF MODERATE TO HEAVY RAIN IS FORECAST TO PERSIST THROUGH EARLY WEDNESDAY EVENING BEFORE FINALLY LETTING UP. THE RAIN COULD BE HEAVY AT TIMES...CREATING THE POTENTIAL FOR LOCALIZED FLOODING. HYDRO ISSUES WILL ALSO BE POSSIBLE SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...AS WIDESPREAD RAIN WILL MELT THE EXISTING SNOW PACK...WHICH WILL CREATE A LARGE AMOUNT OF RUNOFF THAT WILL MAKE ITS WAY INTO AREA CREEKS AND STREAMS. THIS ADDITIONAL WATER WILL LIKELY LEAD TO SIGNIFICANT RISES ON AREA RIVERS AS WELL. A ROUND OF SCATTERED SNOW SHOWERS IS THEN EXPECTED TO MOVE IN BEHIND THE DEPARTING COLD FRONT LATE WEDNESDAY NIGHT AND THURSDAY MORNING...AS COLDER AIR FILTERS IN FROM THE WEST AND NORTHWEST. ONLY LIGHT ACCUMULATIONS ARE POSSIBLE. THE PRECIPITATION SHOULD FINALLY COME TO AN END LATE THURSDAY NIGHT. THE GOOD NEWS IS THAT THE LOW TEMPERATURES WE ARE EXPECTING NEXT WEEK WILL NOT BE ANYWHERE NEAR AS COLD AS WHAT WE HAVE EXPERIENCED THAT PAST TWO WEEKS. THE FIRST COUPLE OF DAYS OF THE EXTENDED ARE FORECAST TO FEATURE ONLY SLIGHTLY BELOW NORMAL TEMPERATURES...WITH LOWS ON SUNDAY MORNING BOTTOMING OUT IN THE MID TO UPPER 20S ACROSS THE AREA. HIGHS ON SUNDAY SHOULD BE ABLE TO CLIMB WELL INTO THE 40S ACROSS THE AREA AS SOUTHERLY FLOW BEGINS TO DOMINATE THE AREA. THE WARM UP IS EXPECTED TO CONTINUE ON TUESDAY AND WEDNESDAY...WITH THE MERCURY FORECAST TO TOP OUT IN THE MID TO UPPER 50S AROUND EASTERN KENTUCKY. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY EVEN REACH 60 DEGREES ON TUESDAY. THE PASSAGE OF A COLD FRONT WILL BRING ANOTHER SHOT OF COLDER AIR INTO THE REGION BY MIDWEEK...WITH HIGHS ON THURSDAY AND FRIDAY ONLY EXPECTED TO MAX OUT IN THE MID TO UPPER 30S. AFTER LOWS IN THE 40S TUESDAY NIGHT...COLDER AIR WILL FILTER INTO THE REGION FOR A FEW DAYS. LOW TEMPERATURES THURSDAY NIGHT COULD CONCEIVABLE FALL INTO THE MID TO UPPER TEENS IN THE WEST TO NORTHWEST FLOW THAT WILL BECOME ESTABLISHED BEHIND YET ANOTHER DEARLY DEPARTED COLD FRONT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 103 AM EST FRI FEB 27 2015 EXPECT SNOW SHOWERS TO CONTINUE INTO THE MORNING HOURS BUT WILL BE ENDING FROM NORTHWEST TO SOUTHEAST. WITH THIS...THERE WILL BE IFR TO MVFR CIGS AND VISIBILITY TO ACCOMPANY THIS ACTIVITY THROUGH DAWN. WINDS WILL GENERALLY BE OUT OF THE NORTH WITH SOME GUSTS AT TIMES TO 15 KNOTS BECOMING LIGHTER INTO THE DAY WITH A LESSENING GRADIENT. BY MIDDAY...THE MVFR CIGS WILL FINALLY LIFT AND VFR CONDITIONS SHOULD PREVAIL THROUGH THE REST OF THE TAF PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHALLENBERGER SHORT TERM...GREIF LONG TERM...AR AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
103 AM EST FRI FEB 27 2015 .UPDATE... ISSUED AT 103 AM EST FRI FEB 27 2015 CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE A WEAK ARCTIC FRONT MOVING THROUGH THE AREA. ASSOCIATED WITH THE FRONT IS SOME WEAK RETURNS SHOWING SOME FLURRIES AND SNOW SHOWERS. SOME OF THESE SNOW SHOWERS HAVE PRODUCED A DUSTING AT MOST IN SOME AREAS WITH SOME VISIBILITIES NEAR A MILE. THIS BAND HAS A FINE EDGE NOW CROSSING I-64. THIS SHOULD BRING AN END TO THE ACTIVITY INTO THE MORNING HOURS. HAVE SENT OUT SOME FRESHENED UP GRIDS TO ADDRESS THIS AND TEMPERATURES AS THE COLDER AIR IS NOW PUSHING THROUGH THE MIDWEST STATES AND NOW INTO KY. THOUGH NO SIGNIFICANT CHANGE WAS MADE TO THE ZFP...THE GRIDS HAVE BEEN SENT TO THE NDFD SERVERS. UPDATE ISSUED AT 945 PM EST THU FEB 26 2015 A DISTURBANCE IS WORKING THROUGH THE GREAT LAKES AND OH VALLEY REGION AND IS BRINGING SOME VERY LIGHT SNOW OR FLURRIES TO THE REGION. AWOS AND ASOS SITES OVER CENTRAL AND NORTHERN KY HAVE REPORTED SNOW REACHING THE GROUND...BUT THE AIRMASS IS RATHER DRY...SO VISIBILITIES AND CEILINGS HAVE NOT DROPPED ALL THAT FAR. AT THIS POINT...PER RADAR AND SFC OBS IT APPEARS THAT THE LIGHT SNOW OR FLURRIES IS NEARING THE SOMERSET TO JACKSON TO SANDY HOOK LINE. ONLY ONE KY MESONET SITE IN CENTRAL KY HAS RECEIVED MEASURABLE PRECIPITATION WITH THIS. THE NEAR TERM MODELS SUCH AS THE HRRR CONTINUE TO HAVE THIS DIMINISHING AS IT MOVES EAST...BUT IT SEEMS TO CLEARLY BE HOLDING TOGETHER BETTER THAN THE HRRR IS FORECASTING. THE WINDS ARE BIT MORE NORTHERLY THAN IDEAL FOR UPSLOPE ALTHOUGH THERE IS A BIT OF AN UPSLOPE COMPONENT. THE CURRENT FORECAST IS MORE REFLECTIVE OF THE MOST RECENT NAM AND GFS RUNS AS SEEMS MORE REASONABLE GIVEN UPSTREAM TRENDS. AT THIS POINT...SLIGHT CHANCE TO CHANCE POPS APPEAR TO REMAIN IN ORDER AND AN SPS IS ALREADY IN PLACE. SOME LOCATIONS MAY PICK UP A QUARTER TO A HALF OF AN INCH OF FLUFF WHILE OTHER LOCATIONS MAY ONLY GET A LIGHT DUSTING OR NOTHING AT ALL. THE BIGGER STORY WILL BE THE COLDER AIR WORKING INTO THE REGION LATE TONIGHT. LOWS SHOULD REACH THE UPPER SINGLE DIGITS ABOVE ZERO NORTH...WITH UPPER TEENS NEAR THE TN BORDER. TEMPS WILL STRUGGLE TO REACH THE MID TO UPPER 20S IN MANY LOCATIONS ON FRIDAY...ALTHOUGH FRI NIGHT APPEARS TO BE COLDER ON AVERAGE THAN TONIGHT. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 355 PM EST THU FEB 26 2015 19Z SFC ANALYSIS SHOWS LOW PRESSURE PASSING BY TO THE EAST WHILE A DEEP LOW IS APPROACHING FROM THE NORTHWEST. AN ARCTIC COLD FRONT FROM THIS IS MOVING INTO KENTUCKY AND THIS WILL SWEEP ACROSS EASTERN KENTUCKY LATER THIS EVENING. ON REGIONAL RADAR...THE LIGHT SNOW ASSOCIATED WITH THIS BOUNDARY IS STARTING TO SETTLE DEEPER INTO THE STATE. EAST KENTUCKY SAW PARTLY SUNNY SKIES THIS AFTERNOON WITH SOME LOW CLOUDS CLINGING TO OUR FAR EASTERN AREAS WHILE HIGH CLOUDS PASSED THROUGH NORTHERN PARTS OF THE CWA. LOWER CLOUDS ARE INBOUND FROM WESTERN AND CENTRAL KENTUCKY NOW...AHEAD OF THAT FRONT. TEMPERATURES WERE ABLE TO SPIKE UP TO NEAR 40 DEGREES FOR MUCH OF THE AREA THIS AFTERNOON THANKS TO THE PARTIAL SUNSHINE WHILE ONLY LOW 30S WERE ACHIEVED IN THE NORTHWEST. DEWPOINTS REMAIN IN THE TEENS IN THE NORTHWEST WHILE LOWER AND MIDDLE 20S ARE FOUND IN THE EAST. WINDS WERE GENERALLY FROM THE NORTHWEST AT 5 TO 10 MPH WITH GUSTS TO 15 MPH. THE MODELS ARE IN GOOD AGREEMENT ALOFT AS A WEAK WAVE PASSES TO THE SOUTH OF THE AREA THIS EVENING FOLLOWED BY A STRONGER AND LARGER TROUGH THAT SETTLES INTO THE OHIO VALLEY TONIGHT. THIS TROUGH WILL BRING ITS CORE ENERGY ACROSS OHIO DURING THE DAY FRIDAY BEFORE TAPERING OFF AMIDST REBOUNDING HEIGHTS OVER KENTUCKY FRIDAY NIGHT. THE ECMWF IS A BIT QUICKER THAN THE OTHER MODELS WITH THESE HEIGHT RISES AND MAY BE GETTING AHEAD OF ITSELF. GIVEN THE GENERAL AGREEMENT...AT LEAST INTO FRIDAY EVENING...HAVE FAVORED THE HIGHER RESOLUTION MODEL GUIDANCE FROM THE HRRR... RAP13...AND NAM12 FOR WX SPECIFICS. SENSIBLE WEATHER WILL FEATURE CLOUDS ARRIVING ALONG WITH SNOW SHOWERS THIS EVENING AND CONTINUING THROUGH THE NIGHT IN ASSOCIATION WITH THE ARCTIC AIR POURING BACK INTO THIS PART OF THE STATE. TEMPERATURES WILL FALL INTO THE TEENS IN MOST PLACES BY DAWN THANKS TO THE CAA WITH SOME SINGLE DIGITS POSSIBLE NORTH OF INTERSTATE 64. ANY LINGERING SNOW SHOWERS WILL COME TO AN END FRIDAY MORNING IN FAR EASTERN PARTS OF THE AREA WITH SOME SUNSHINE POSSIBLE BY AFTERNOON...BUT TEMPERATURES WILL STILL STRUGGLE TO MAKE IT INTO THE LOWER 20S BY MIDDAY. THIS SETS THE STAGE FOR A VERY CHILLY NIGHT WITH SINGLE DIGITS LIKELY ON TAP FOR THE VALLEYS AND MORE OPEN AREAS...WHILE SOME LATE ARRIVING HIGH CLOUDS AND THE INVERSION MAY SPARE THE RIDGES THE COLDEST OF THE AIR. CANNOT RULE OUT SOME FLURRIES ARRIVING TOWARD DAWN SATURDAY AHEAD OF THE NEXT SYSTEM...BUT HAVE LEFT THEM OUT FOR NOW. AGAIN USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE DAY FRIDAY...WITH SOME TERRAIN BASED ADJUSTMENTS MADE AT NIGHT. AFTER THAT...USED THE SUPERBLEND TO INITIATE THE GRIDS INTO SATURDAY MORNING WITH MINOR CHANGES. AS FOR POPS...ENDED UP ON THE HIGH SIDE...CLOSER TO THE MET...OF RATHER LOW MOS GUIDANCE TONIGHT...THEN SIMILAR FOR THE REST OF THE SHORT TERM. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 400 PM EST THU FEB 26 2015 BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED. THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING. ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION. CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN. MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/ SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD. THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE YEAR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 103 AM EST FRI FEB 27 2015 EXPECT SNOW SHOWERS TO CONTINUE INTO THE MORNING HOURS BUT WILL BE ENDING FROM NORTHWEST TO SOUTHEAST. WITH THIS...THERE WILL BE IFR TO MVFR CIGS AND VISIBILITY TO ACCOMPANY THIS ACTIVITY THROUGH DAWN. WINDS WILL GENERALLY BE OUT OF THE NORTH WITH SOME GUSTS AT TIMES TO 15 KNOTS BECOMING LIGHTER INTO THE DAY WITH A LESSENING GRADIENT. BY MIDDAY...THE MVFR CIGS WILL FINALLY LIFT AND VFR CONDITIONS SHOULD PREVAIL THROUGH THE REST OF THE TAF PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHALLENBERGER SHORT TERM...GREIF LONG TERM...SBH AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1241 PM EST FRI FEB 27 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 402 AM EST FRI FEB 27 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT OVER THE UPR GREAT LKS TO THE SW OF CLOSED H5 LO OVER NRN QUEBEC. SHRTWV RDG AXIS STRETCHING FM THE NRN PLAINS INTO NW ONTARIO IS SUPPORTING A SFC HI PRES STRETCHING FM THE NRN PLAINS INTO IOWA. UPR MI IS DOMINATED BY A DRY WNW LLVL FLOW E OF THIS HI CENTER /00Z PWATS UPSTREAM ARE GENERALLY 0.05 TO 0.10 INCH...NO MORE THAN 50 PCT OF NORMAL/. COMBINATION OF THE DRYNESS OF THE UPSTREAM AIRMASS...00Z INL AND YPL RAOBS SHOW AN INVERTED V T/TD PROFILE BLO SUBSIDENCE INVRN NEAR H9...AND EXTENSIVE ICE COVER OVER LK SUP HAS GREATLY DIMINISHED THE LES. IN FACT...IR STLT IMAGERY SHOWS ONLY PATCHY LK CLDS STREAMING INTO AREAS E OF MUNISING. 00Z H85 TEMPS OVER THE AREA RANGE FM -23C AT GRB TO -19C AT INL/YPL AND THEN UP TO -16C AT THE PAS MANITOBA. UNDER THE MOCLR SKIES/DRY ARCTIC AIRMASS...TEMPS HAVE FALLEN WELL BLO ZERO OVER THE INTERIOR AND AS LO AS -25F TO -30F AT THE MORE SHELTERED RURAL SPOTS. WINDS ARE STIRRING A BIT MORE NEAR LK SUP UNDER A TIGHTER PRES GRADIENT...AND SOME OF THE MORE EXPOSED LOCATIONS THERE ARE INDICATING WIND CHILLS AS LO AS -25F. MAIN FCST CONCERNS THRU TNGT WL BE ON TEMPS. OPTED TO ISSUE AN SPS TO COVER WIND CHILLS NEAR ADVY CRITERIA AT THE MORE EXPOSED LOCATIONS NEAR LK SUP THIS MRNG. TODAY...AS SHRTWV RDG TO THE NW SLIDES TO THE SE...SFC HI PRES CENTER IS FCST TO SHIFT TO INDIANA/ILLINOIS BY 00Z SAT. THE COMBINATION OF ONGOING SUBSIDENCE AHEAD OF THE SHRTWV RDG AND SOME WAA AS THE SFC-H925 FLOW BACKS TO THE WSW...IS FCST TO RAISE H85 TEMPS UP TO -16 TO -17C BY THE END OF THE DAY. GIVEN ABSENCE OF MUCH DIURNAL CU UPSTREAM YDAY AND LARGER SCALE SUBSIDENCE/WRMG AT H85... SUSPECT THERE WL ONLY BE SOME SCT DIURNAL CLDS OVER THE INTERIOR THIS AFTN. AS THE FLOW BACKS...LINGERING LK CLDS/ANY FLURRIES E OF MUNISING THIS MRNG SHOULD SHIFT OUT OVER LK SUP IN THE AFTN. WITH A GOOD DEAL OF SUNSHINE...GOING FCST HI TEMPS RECOVERING INTO THE TEENS APPEAR TO BE ON TRACK. TNGT...SFC HI PRES IS FCST TO SLIDE INTO THE MID ATLANTIC STATES BY 12Z SUN...WITH STEADY WSW WIND REMAINING IN PLACE UNDER THE TIGHT PRES GRADIENT TO THE NW OF THIS FEATURE. ALOFT...UPR MI BE UNDER CONTINUED SUBSIDENCE AHEAD OF ANOTHER SHRTWV RDG APRCHG FM THE W. WITH A CONTINUED SLOW WARMING OF THE H85 TEMPS...AN ABSENCE OF ANY SGNFT LLVL MSTR INFLOW AND GENERALY ACYC NATURE OF THE W FLOW...LK CLDS OVER THE KEWEENAW SHOULD BE SCT AT BEST. ANY LK CLDS/LES OVER THE E HALF OF THE LK SHOULD REMAIN OFFSHORE. PWAT IS FCST TO BE AOB 0.10 INCH...SO TENDED TO GO AOB THE LO END OF GUIDANCE FOR MIN TEMPS /AS IS OBSVD THIS MRNG/ IN AREAS AWAY FM LK SUP...WHERE A STEADIER WIND SHOULD LIMIT THE DIURNAL TEMP DROP. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 402 AM EST FRI FEB 27 2015 SATURDAY INTO SATURDAY NIGHT...A BROAD SURFACE HIGH PRESSURE SYSTEM OVER MUCH OF THE GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH THE DAY SATURDAY. THIS WILL KEEP FAIRLY DRY AIR IN PLACE ALLOWING MOST AREAS OF THE U.P. TO SEE SUNNY SKIES THROUGH THE DAY SATURDAY. BY SATURDAY NIGHT...THE HIGH PRESSURE CENTER WILL SHIFT EASTWARD STRETCHING FROM THE NORTHEAST U.S. SOUTHWARD ALONG THE EASTERN SEABOARD. AT THIS HAPPENS...A WEAK SURFACE TROUGH/COLD FRONT WILL APPROACH THE AREA FROM THE WEST. OVERALL MOISTURE APPEARS TO BE LIMITED AND FOCUSED MAINLY TO THE SOUTH OF THE U.P. THEREFORE...ONLY EXPECTING AN INCREASE IN CLOUD COVER SATURDAY NIGHT WITH ONLY A SMALL CHANCE OF LIGHT SNOW ACROSS THE U.P. WITH LIMITED/WEAK FORCING. SUNDAY THROUGH MONDAY...THE SURFACE TROUGH/WEAK COLD FRONT WILL CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE UPPER PENINSULA THROUGH THE DAY SUNDAY. AGAIN...MOISTURE WILL BE LIMITED ALONG THE FRONT WITH CONTINUED WEAK FORCING. ONLY LIGHT SNOW IS EXPECTED THROUGH THE DAY SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB TROUGH IS POISED TO SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS HAPPENS...ENOUGH MOISTURE WILL REMAIN IN PLACE WITH VERY SLIGHT ADDITIONAL MOISTURE ADDED FROM THE ICE COVER LAKE SUPERIOR TO ALLOW A CHANCE OF LAKE EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO NORTHWEST WIND FAVORED LOCATIONS. DELTA T VALUES WILL BE SUFFICIENT FOR LAKE EFFECT WITH THE TROUGH AXIS SLIDING ACROSS...BUT LAKE EFFECT INTENSITY WILL BE LIMITED TO AREAS THAT ANY BREAKS IN THE ICE COVER OCCURS. ANY LAKE EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT WILL BE SHORT LIVED AS MUCH DRIER AIR AND HIGH PRESSURE AT THE SURFACE AND SLIGHT RIDGING ALOFT TO PUSH INTO THE UPPER GREAT LAKES REGION DURING THE DAY MONDAY. THIS WILL FOR MAINLY SUNNY SKIES DURING THE DAY MONDAY. MONDAY NIGHT THROUGH WEDNESDAY...THE AFOREMENTIONED HIGH PRESSURE SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES...THEN THE EASTERN SEABOARD MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST SOUTHERLY FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE U.S. ADDITIONALLY...ANOTHER STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. THERE ARE MODEL DIFFERENCES WITH THE PHASING OF THE TWO SYSTEMS. THE 18Z/26 00Z/27 GFS IS MORE PROGRESSIVE WITH BOTH SYSTEMS AND THE PHASING OF THE SYSTEMS. THIS WOULD PUSH SNOW INTO THE AREA AS EARLY AS MONDAY EVENING ON ISENTROPIC UPGLIDE AND INCREASED MOISTURE IN THE AREA. THE EC 12/26 00Z/27 IS MUCH SLOWER WITH THE PHASING...KEEPING THE PRECIPITATION OUT OF THE AREA UNTIL LATE MONDAY NIGHT INTO TUESDAY MORNING. THE BEST CHANCES GIVEN THE OVERLAP OF THE TWO MODEL SOLUTIONS WOULD BE TUESDAY AFTERNOON INTO TUESDAY NIGHT...ESPECIALLY FOR THE EAST HALF OF THE U.P. AT THIS POINT...WILL STICK WITH CHANCE POPS AT LEAST UNTIL THE SYSTEM IS SAMPLED BETTER OVER THE NEXT FEW DAYS. WEDNESDAY NIGHT AND THURSDAY...BOTH THE EC AND GFS AGREE ON AN UPPER LEVEL TROUGH AXIS ALONG WITH DEEPER MOISTURE LINGERING ACROSS THE AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS. GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1240 PM EST FRI FEB 27 2015 WITH DRY HIGH PRES DOMINATING...VFR CONDITIONS WILL BE THE RULE AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD. THERE MAY BE SOME DIURNAL CU/STRATOCU THIS AFTN...MAINLY AT KCMX DUE TO VERY LIMITED MOISTURE ADDED BY SOME BREAKS IN THE ICE COVER ON LAKE SUPERIOR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 AM EST FRI FEB 27 2015 EXPECT WINDS TO BE UNDER 30 KTS THIS FORECAST PERIOD. LAKE SUPERIOR IS MAINLY ICE COVERED THIS MORNING. ALTHOUGH SHIFTING WINDS UP TO 20 TO 25 KTS ACCOMPANYING THE PASSAGE OF DISTURBANCES THRU THE UPPER LAKES MAY CAUSE HOLES TO OPEN IN THE ICE FROM TIME TO TIME...A CONTINUED DOMINANCE OF ARCTIC AIR WILL MAINTAIN AN OVERALL EXTENSIVE ICE COVER. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1202 PM EST FRI FEB 27 2015 .AVIATION... VERY DRY AIRMASS IN PLACE...BUT DEVELOPING LIGHT LOW LEVEL SOUTHWEST FLOW IS ALLOWING LAKE INDUCED CLOUDS FROM LAKE MICHIGAN TO ADVECT EASTWARD...AND IT APPEARS MBS WILL HAVE TO DEAL WITH THE LOW VFR/BORDERLINE MVFR CEILINGS THIS AFTERNOON INTO THIS EVENING...WITH DIMINISHING CHANCES FARTHER SOUTH...AS STRONG SURFACE HIGH ACROSS THE NORTHERN OHIO VALLEY SHOULD ASSURE CLEAR SKIES TONIGHT ACROSS THE DETROIT TAFS WITH NEARLY CALM WINDS. MOSTLY CLEAR SKIES WILL PERSIST INTO TOMORROW...WITH JUST INCREASING MID/HIGH CLOUDS LATE IN THE DAY. //DTW THRESHOLD PROBABILITIES... * LOW CONFIDENCE IN CEILING BELOW 5000 FT THIS AFTERNOON. && .PREV DISCUSSION...ISSUED 846 AM EST FRI FEB 27 2015 UPDATE... ANOTHER RECORD SETTING COLD MORNING AS ALL THREE CLIMATE SITES BROKE OR TIED THEIR RESPECTIVE DAILY RECORDS. FNT LOW WAS AT LEAST -17 F (UNABLE TO DIAL IN TO GET FINAL VALUE). SAGINAW LOW WAS -9 AT 707 AM. DETROIT TIED RECORD LOW...WITH -4 F AT 717 AM. 12Z DTX SOUNDING INDICATED A 925 MB TEMP OF -19 C...AND WITH THE COLD START AND SOME LAKE CLOUDS EXPECTED TO PUSH EAST THIS AFTERNOON (SEE RUC13 925 MB RH) UNDER LIGHT WESTERLY FLOW...ESPECIALLY NORTHERN AREAS...MAXES WILL PROBABLY ONLY TOP OUT IN THE MID TEENS...ON THE LOWER END OF THE GOING FORECAST. PREV DISCUSSION...ISSUED 358 AM EST FRI FEB 27 2015 SHORT TERM...TODAY AND TONIGHT RECORD LOWS FOR FEB 27 DETROIT AREA: -4 (1934) FLINT AREA: -14 (1994) SAGINAW: -8 (1934) ANOTHER COLD MORNING ACROSS SOUTHEASTERN MICHIGAN WITH AN ARCTIC SURFACE RIDGE LOCKED IN OVERHEAD. NIL WIND AND CLEAR SKIES HAS LED TO FAVORABLE RADIATIVE COOLING CONDITIONS. SURFACE TEMPERATURES CURRENTLY RANGE FROM 0 TO 10 DEGREES BELOW ZERO AS OF 3AM. WITH A LACK OF LOW CLOUD DISCERNIBLE IN IR IMAGERY...EXPECTATIONS ARE FOR SURFACE TEMPERATURES TO CONTINUE TO BOTTOM OUT BEFORE SUNRISE WITH MANY RURAL LOCATIONS REACHING 10 TO 20 DEGREES BELOW ZERO. WITH A DECOUPLED SURFACE LAYER...WILL HONOR THE DECISION OF PRIOR SHIFTS AND NOT ISSUE A WIND CHILL ADVISORY. COLDEST MIDLEVEL TEMPERATURES PUSHING OUT OF THE STATE TODAY IN COMBINATION WITH AN SURFACE ANTICYCLONE PUSHING INTO PORTIONS OF OHIO WILL ALLOW WIND DIRECTIONS OVER SOUTHEASTERN MICHIGAN TO MAKE A CONCERTED MOVE TO SOUTHWESTERLY. ENHANCED MOISTURE AND LAKE MICHIGAN CLOUD DEBRIS IS PROGGED TO STREAM EASTWARD WITH TIME...SHOWN TO SLIDE THROUGH PORTIONS OF THE CWA BY THIS AFTERNOON AND INTO THE EARLY EVENING. RAP SOUNDINGS SUGGEST THERE WILL BE A CONSIDERABLE DIURNAL COMPONENT TO ANY SKY COVER. WIND TRAJECTORIES POINT TO THE NORTHERN CWA/SAGAINAW VALLEY AS THE MORE FAVORABLE LOCATION FOR CLOUDS. WITH SUN...SHADED A DEGREE OR TWO HIGHER THAN MOS GUIDANCE FOR HIGHS. SURFACE HIGH PRESSURE PUSHING THROUGH INDIANA AND OHIO WILL SET ANOTHER NIGHT UP FOR CALM WINDS ACROSS THE SOUTHERN HALF OF THE CWA. LOWERED MINS FOR AREAS SOUTH OF DETROIT. OTHERWISE...A PRESSURE GRADIENT IN PLACE OVER THE TRI CITIES/NORTHERN THUMB AND SOME POTENTIAL FOR LINGERING CLOUDS LIMITS THE TEMPERATURE FALL POTENTIAL FOR TONIGHT. LONG TERM... COLD AIRMASS WILL REMAIN IN PLACE INTO EARLY THIS WEEKEND ALTHOUGH TEMPERATURES WILL MODERATE EVER SO SLIGHTLY AS THE LATEST ARCTIC HIGH PRESSURE SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT. HIGHS ON SATURDAY WILL CLIMB TO AROUND 20F WITH LOWS THAT NIGHT HOLDING INTO THE SINGLE DIGITS TO NEAR 10F AS BOTH THE COLDEST AIR SHIFTS EAST AND EXPANDING CLOUD COVER WORKS INTO THE AREA WITH THE APPROACH OF A LOW PRESSURE SYSTEM. 00Z MODEL RUNS...SAVE THE NAM12...BASICALLY SUPPORT THE PREVIOUS FORECAST AS ROUGHLY 1 TO 2 INCHES OF SNOW FALL FROM THE I-69 CORRIDOR NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY EVENING WITH 2 TO 3 INCHES SOUTH OF THAT INTO METRO DETROIT AS H7 SPECIFIC HUMIDITY CLIMBS TO AROUND 2 G/KG ALONG THE M-59 CORRIDOR. GIVEN THE RELATIVELY HIGH SNOW TO LIQUID RATIOS EXPECTED WITH THE COLD AIRMASS IN PLACE...15:1 OR A BIT MORE...WOULD NOT BE SURPRISED TO SEE UP TO 4 INCHES FROM THE I-94 CORRIDOR SOUTHWARD. TEMPERATURES WILL EDGE BACK DOWN EARLY NEXT WEEK...BUT TO MUCH MORE REASONABLE LEVELS THAN THE PAST SEVERAL WEEKS AS HIGHS MONDAY REACH THE MID/UPPER 20S AND LOWS HOLD IN THE TEENS SUNDAY AND MONDAY NIGHT. THE NEXT LOW PRESSURE SYSTEM APPEARS TO BE SHAPING UP TO BE A STRONGER SYSTEM THAN THE WEEKEND EVENT...WITH A TRACK THAT WOULD SUPPORT A WIDE VARIETY OF PRECIPITATION ACROSS THE CWA ON TUESDAY WITH PRIMARILY SNOW OVER THE NORTHERN CWA AND SNOW CHANGING TO A MIX AND THEN EVENTUALLY RAIN FURTHER SOUTH. WITH THE EVENTUAL TRACK AND STRENGTH OF THIS SYSTEM STILL IN DOUBT...WILL FORGO ANY SIGNIFICANT DETAILS AT THIS TIME...OTHER THAN TO INCLUDE SOME MENTION OF SLEET...FREEZING RAIN AND RAIN AS 00Z RUNS OF THE GFS...CMC AND ECMWF DO NOT SUPPORT AN ALL SNOW EVENT FOR THE ENTIRE CWA. MARINE... HIGH PRESSURE WILL BE BUILD FROM THE MID MISSISSIPPI VALLEY TODAY THROUGH THE OHIO VALLEY ON SATURDAY. MODEST SOUTHWEST RETURN FLOW WILL DEVELOP AROUND THIS HIGH OVER THE CENTRAL GREAT LAKES. CENTRAL SECTIONS OF LAKE HURON WILL MOST LIKELY SEE WINDS INCREASE INTO THE 15 TO 20 KNOT RANGE. OTHERWISE...WINDS WILL REMAIN ON THE LIGHT SIDE AS THIS SOUTHWEST PRESSURE GRADIENT WEAKENS LATE IN THE WEEKEND AS A WEAK LOW PRESSURE SYSTEM LIFTS INTO THE REGION. EVEN THE RETURN OF COLD NORTHWEST FLOW IN THE WAKE OF THE ATTENDING COLD FRONT WILL BE LIMITED TO 25 KNOT GUSTS OR LESS OVER MUCH OF LAKE HURON. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....SF UPDATE.......SF SHORT TERM...CB LONG TERM....DG MARINE.......DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
846 AM EST FRI FEB 27 2015 .UPDATE... ANOTHER RECORD SETTING COLD MORNING AS ALL THREE CLIMATE SITES BROKE OR TIED THEIR RESPECTIVE DAILY RECORDS. FNT LOW WAS AT LEAST -17 F (UNABLE TO DIAL IN TO GET FINAL VALUE). SAGINAW LOW WAS -9 AT 707 AM. DETROIT TIED RECORD LOW...WITH -4 F AT 717 AM. 12Z DTX SOUNDING INDICATED A 925 MB TEMP OF -19 C...AND WITH THE COLD START AND SOME LAKE CLOUDS EXPECTED TO PUSH EAST THIS AFTERNOON (SEE RUC13 925 MB RH) UNDER LIGHT WESTERLY FLOW...ESPECIALLY NORTHERN AREAS...MAXES WILL PROBABLY ONLY TOP OUT IN THE MID TEENS...ON THE LOWER END OF THE GOING FORECAST. && .AVIATION...ISSUED 550 AM EST FRI FEB 27 2015 SURFACE HIGH PRESSURE BUILDING EASTWARD INTO THE REGION WILL CONTINUE TO SUPPORT A VERY DRY AIR MASS. WIND DIRECTIONS ARE FORECASTED TO EMERGE SOUTHWESTERLY TODAY...BRINGING THE POTENTIAL FOR LAKE MICHIGAN MOISTURE TO WORK UNDER THE INVERSION BASE AT 4-5 KFT AGL. MODEL SOUNDINGS ALSO SUPPORT A DIURNAL COMPONTENT TO POTENTIAL CLOUD COVER. DOWNSTREAM TRAJECTORY CONTINUES TO SUPPORT THE BEST POTENTIAL FOR THE NORTHERN TAF SITES. //DTW THRESHOLD PROBABILITIES... * LOW CONFIDENCE IN CEILING BELOW 5000 FT FRIDAY AFTERNOON. && .PREV DISCUSSION...ISSUED 358 AM EST FRI FEB 27 2015 SHORT TERM...TODAY AND TONIGHT RECORD LOWS FOR FEB 27 DETROIT AREA: -4 (1934) FLINT AREA: -14 (1994) SAGINAW: -8 (1934) ANOTHER COLD MORNING ACROSS SOUTHEASTERN MICHIGAN WITH AN ARCTIC SURFACE RIDGE LOCKED IN OVERHEAD. NIL WIND AND CLEAR SKIES HAS LED TO FAVORABLE RADIATIVE COOLING CONDITIONS. SURFACE TEMPERATURES CURRENTLY RANGE FROM 0 TO 10 DEGREES BELOW ZERO AS OF 3AM. WITH A LACK OF LOW CLOUD DISCERNIBLE IN IR IMAGERY...EXPECTATIONS ARE FOR SURFACE TEMPERATURES TO CONTINUE TO BOTTOM OUT BEFORE SUNRISE WITH MANY RURAL LOCATIONS REACHING 10 TO 20 DEGREES BELOW ZERO. WITH A DECOUPLED SURFACE LAYER...WILL HONOR THE DECISION OF PRIOR SHIFTS AND NOT ISSUE A WIND CHILL ADVISORY. COLDEST MIDLEVEL TEMPERATURES PUSHING OUT OF THE STATE TODAY IN COMBINATION WITH AN SURFACE ANTICYCLONE PUSHING INTO PORTIONS OF OHIO WILL ALLOW WIND DIRECTIONS OVER SOUTHEASTERN MICHIGAN TO MAKE A CONCERTED MOVE TO SOUTHWESTERLY. ENHANCED MOISTURE AND LAKE MICHIGAN CLOUD DEBRIS IS PROGGED TO STREAM EASTWARD WITH TIME...SHOWN TO SLIDE THROUGH PORTIONS OF THE CWA BY THIS AFTERNOON AND INTO THE EARLY EVENING. RAP SOUNDINGS SUGGEST THERE WILL BE A CONSIDERABLE DIURNAL COMPONENT TO ANY SKY COVER. WIND TRAJECTORIES POINT TO THE NORTHERN CWA/SAGAINAW VALLEY AS THE MORE FAVORABLE LOCATION FOR CLOUDS. WITH SUN...SHADED A DEGREE OR TWO HIGHER THAN MOS GUIDANCE FOR HIGHS. SURFACE HIGH PRESSURE PUSHING THROUGH INDIANA AND OHIO WILL SET ANOTHER NIGHT UP FOR CALM WINDS ACROSS THE SOUTHERN HALF OF THE CWA. LOWERED MINS FOR AREAS SOUTH OF DETROIT. OTHERWISE...A PRESSURE GRADIENT IN PLACE OVER THE TRI CITIES/NORTHERN THUMB AND SOME POTENTIAL FOR LINGERING CLOUDS LIMITS THE TEMPERATURE FALL POTENTIAL FOR TONIGHT. LONG TERM... COLD AIRMASS WILL REMAIN IN PLACE INTO EARLY THIS WEEKEND ALTHOUGH TEMPERATURES WILL MODERATE EVER SO SLIGHTLY AS THE LATEST ARCTIC HIGH PRESSURE SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT. HIGHS ON SATURDAY WILL CLIMB TO AROUND 20F WITH LOWS THAT NIGHT HOLDING INTO THE SINGLE DIGITS TO NEAR 10F AS BOTH THE COLDEST AIR SHIFTS EAST AND EXPANDING CLOUD COVER WORKS INTO THE AREA WITH THE APPROACH OF A LOW PRESSURE SYSTEM. 00Z MODEL RUNS...SAVE THE NAM12...BASICALLY SUPPORT THE PREVIOUS FORECAST AS ROUGHLY 1 TO 2 INCHES OF SNOW FALL FROM THE I-69 CORRIDOR NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY EVENING WITH 2 TO 3 INCHES SOUTH OF THAT INTO METRO DETROIT AS H7 SPECIFIC HUMIDITY CLIMBS TO AROUND 2 G/KG ALONG THE M-59 CORRIDOR. GIVEN THE RELATIVELY HIGH SNOW TO LIQUID RATIOS EXPECTED WITH THE COLD AIRMASS IN PLACE...15:1 OR A BIT MORE...WOULD NOT BE SURPRISED TO SEE UP TO 4 INCHES FROM THE I-94 CORRIDOR SOUTHWARD. TEMPERATURES WILL EDGE BACK DOWN EARLY NEXT WEEK...BUT TO MUCH MORE REASONABLE LEVELS THAN THE PAST SEVERAL WEEKS AS HIGHS MONDAY REACH THE MID/UPPER 20S AND LOWS HOLD IN THE TEENS SUNDAY AND MONDAY NIGHT. THE NEXT LOW PRESSURE SYSTEM APPEARS TO BE SHAPING UP TO BE A STRONGER SYSTEM THAN THE WEEKEND EVENT...WITH A TRACK THAT WOULD SUPPORT A WIDE VARIETY OF PRECIPITATION ACROSS THE CWA ON TUESDAY WITH PRIMARILY SNOW OVER THE NORTHERN CWA AND SNOW CHANGING TO A MIX AND THEN EVENTUALLY RAIN FURTHER SOUTH. WITH THE EVENTUAL TRACK AND STRENGTH OF THIS SYSTEM STILL IN DOUBT...WILL FORGO ANY SIGNIFICANT DETAILS AT THIS TIME...OTHER THAN TO INCLUDE SOME MENTION OF SLEET...FREEZING RAIN AND RAIN AS 00Z RUNS OF THE GFS...CMC AND ECMWF DO NOT SUPPORT AN ALL SNOW EVENT FOR THE ENTIRE CWA. MARINE... HIGH PRESSURE WILL BE BUILD FROM THE MID MISSISSIPPI VALLEY TODAY THROUGH THE OHIO VALLEY ON SATURDAY. MODEST SOUTHWEST RETURN FLOW WILL DEVELOP AROUND THIS HIGH OVER THE CENTRAL GREAT LAKES. CENTRAL SECTIONS OF LAKE HURON WILL MOST LIKELY SEE WINDS INCREASE INTO THE 15 TO 20 KNOT RANGE. OTHERWISE...WINDS WILL REMAIN ON THE LIGHT SIDE AS THIS SOUTHWEST PRESSURE GRADIENT WEAKENS LATE IN THE WEEKEND AS A WEAK LOW PRESSURE SYSTEM LIFTS INTO THE REGION. EVEN THE RETURN OF COLD NORTHWEST FLOW IN THE WAKE OF THE ATTENDING COLD FRONT WILL BE LIMITED TO 25 KNOT GUSTS OR LESS OVER MUCH OF LAKE HURON. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......SF AVIATION.....99 SHORT TERM...CB LONG TERM....DG MARINE.......DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
619 AM EST FRI FEB 27 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 402 AM EST FRI FEB 27 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT OVER THE UPR GREAT LKS TO THE SW OF CLOSED H5 LO OVER NRN QUEBEC. SHRTWV RDG AXIS STRETCHING FM THE NRN PLAINS INTO NW ONTARIO IS SUPPORTING A SFC HI PRES STRETCHING FM THE NRN PLAINS INTO IOWA. UPR MI IS DOMINATED BY A DRY WNW LLVL FLOW E OF THIS HI CENTER /00Z PWATS UPSTREAM ARE GENERALLY 0.05 TO 0.10 INCH...NO MORE THAN 50 PCT OF NORMAL/. COMBINATION OF THE DRYNESS OF THE UPSTREAM AIRMASS...00Z INL AND YPL RAOBS SHOW AN INVERTED V T/TD PROFILE BLO SUBSIDENCE INVRN NEAR H9...AND EXTENSIVE ICE COVER OVER LK SUP HAS GREATLY DIMINISHED THE LES. IN FACT...IR STLT IMAGERY SHOWS ONLY PATCHY LK CLDS STREAMING INTO AREAS E OF MUNISING. 00Z H85 TEMPS OVER THE AREA RANGE FM -23C AT GRB TO -19C AT INL/YPL AND THEN UP TO -16C AT THE PAS MANITOBA. UNDER THE MOCLR SKIES/DRY ARCTIC AIRMASS...TEMPS HAVE FALLEN WELL BLO ZERO OVER THE INTERIOR AND AS LO AS -25F TO -30F AT THE MORE SHELTERED RURAL SPOTS. WINDS ARE STIRRING A BIT MORE NEAR LK SUP UNDER A TIGHTER PRES GRADIENT...AND SOME OF THE MORE EXPOSED LOCATIONS THERE ARE INDICATING WIND CHILLS AS LO AS -25F. MAIN FCST CONCERNS THRU TNGT WL BE ON TEMPS. OPTED TO ISSUE AN SPS TO COVER WIND CHILLS NEAR ADVY CRITERIA AT THE MORE EXPOSED LOCATIONS NEAR LK SUP THIS MRNG. TODAY...AS SHRTWV RDG TO THE NW SLIDES TO THE SE...SFC HI PRES CENTER IS FCST TO SHIFT TO INDIANA/ILLINOIS BY 00Z SAT. THE COMBINATION OF ONGOING SUBSIDENCE AHEAD OF THE SHRTWV RDG AND SOME WAA AS THE SFC-H925 FLOW BACKS TO THE WSW...IS FCST TO RAISE H85 TEMPS UP TO -16 TO -17C BY THE END OF THE DAY. GIVEN ABSENCE OF MUCH DIURNAL CU UPSTREAM YDAY AND LARGER SCALE SUBSIDENCE/WRMG AT H85... SUSPECT THERE WL ONLY BE SOME SCT DIURNAL CLDS OVER THE INTERIOR THIS AFTN. AS THE FLOW BACKS...LINGERING LK CLDS/ANY FLURRIES E OF MUNISING THIS MRNG SHOULD SHIFT OUT OVER LK SUP IN THE AFTN. WITH A GOOD DEAL OF SUNSHINE...GOING FCST HI TEMPS RECOVERING INTO THE TEENS APPEAR TO BE ON TRACK. TNGT...SFC HI PRES IS FCST TO SLIDE INTO THE MID ATLANTIC STATES BY 12Z SUN...WITH STEADY WSW WIND REMAINING IN PLACE UNDER THE TIGHT PRES GRADIENT TO THE NW OF THIS FEATURE. ALOFT...UPR MI BE UNDER CONTINUED SUBSIDENCE AHEAD OF ANOTHER SHRTWV RDG APRCHG FM THE W. WITH A CONTINUED SLOW WARMING OF THE H85 TEMPS...AN ABSENCE OF ANY SGNFT LLVL MSTR INFLOW AND GENERALY ACYC NATURE OF THE W FLOW...LK CLDS OVER THE KEWEENAW SHOULD BE SCT AT BEST. ANY LK CLDS/LES OVER THE E HALF OF THE LK SHOULD REMAIN OFFSHORE. PWAT IS FCST TO BE AOB 0.10 INCH...SO TENDED TO GO AOB THE LO END OF GUIDANCE FOR MIN TEMPS /AS IS OBSVD THIS MRNG/ IN AREAS AWAY FM LK SUP...WHERE A STEADIER WIND SHOULD LIMIT THE DIURNAL TEMP DROP. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 402 AM EST FRI FEB 27 2015 SATURDAY INTO SATURDAY NIGHT...A BROAD SURFACE HIGH PRESSURE SYSTEM OVER MUCH OF THE GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH THE DAY SATURDAY. THIS WILL KEEP FAIRLY DRY AIR IN PLACE ALLOWING MOST AREAS OF THE U.P. TO SEE SUNNY SKIES THROUGH THE DAY SATURDAY. BY SATURDAY NIGHT...THE HIGH PRESSURE CENTER WILL SHIFT EASTWARD STRETCHING FROM THE NORTHEAST U.S. SOUTHWARD ALONG THE EASTERN SEABOARD. AT THIS HAPPENS...A WEAK SURFACE TROUGH/COLD FRONT WILL APPROACH THE AREA FROM THE WEST. OVERALL MOISTURE APPEARS TO BE LIMITED AND FOCUSED MAINLY TO THE SOUTH OF THE U.P. THEREFORE...ONLY EXPECTING AN INCREASE IN CLOUD COVER SATURDAY NIGHT WITH ONLY A SMALL CHANCE OF LIGHT SNOW ACROSS THE U.P. WITH LIMITED/WEAK FORCING. SUNDAY THROUGH MONDAY...THE SURFACE TROUGH/WEAK COLD FRONT WILL CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE UPPER PENINSULA THROUGH THE DAY SUNDAY. AGAIN...MOISTURE WILL BE LIMITED ALONG THE FRONT WITH CONTINUED WEAK FORCING. ONLY LIGHT SNOW IS EXPECTED THROUGH THE DAY SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB TROUGH IS POISED TO SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS HAPPENS...ENOUGH MOISTURE WILL REMAIN IN PLACE WITH VERY SLIGHT ADDITIONAL MOISTURE ADDED FROM THE ICE COVER LAKE SUPERIOR TO ALLOW A CHANCE OF LAKE EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO NORTHWEST WIND FAVORED LOCATIONS. DELTA T VALUES WILL BE SUFFICIENT FOR LAKE EFFECT WITH THE TROUGH AXIS SLIDING ACROSS...BUT LAKE EFFECT INTENSITY WILL BE LIMITED TO AREAS THAT ANY BREAKS IN THE ICE COVER OCCURS. ANY LAKE EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT WILL BE SHORT LIVED AS MUCH DRIER AIR AND HIGH PRESSURE AT THE SURFACE AND SLIGHT RIDGING ALOFT TO PUSH INTO THE UPPER GREAT LAKES REGION DURING THE DAY MONDAY. THIS WILL FOR MAINLY SUNNY SKIES DURING THE DAY MONDAY. MONDAY NIGHT THROUGH WEDNESDAY...THE AFOREMENTIONED HIGH PRESSURE SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES...THEN THE EASTERN SEABOARD MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST SOUTHERLY FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE U.S. ADDITIONALLY...ANOTHER STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. THERE ARE MODEL DIFFERENCES WITH THE PHASING OF THE TWO SYSTEMS. THE 18Z/26 00Z/27 GFS IS MORE PROGRESSIVE WITH BOTH SYSTEMS AND THE PHASING OF THE SYSTEMS. THIS WOULD PUSH SNOW INTO THE AREA AS EARLY AS MONDAY EVENING ON ISENTROPIC UPGLIDE AND INCREASED MOISTURE IN THE AREA. THE EC 12/26 00Z/27 IS MUCH SLOWER WITH THE PHASING...KEEPING THE PRECIPITATION OUT OF THE AREA UNTIL LATE MONDAY NIGHT INTO TUESDAY MORNING. THE BEST CHANCES GIVEN THE OVERLAP OF THE TWO MODEL SOLUTIONS WOULD BE TUESDAY AFTERNOON INTO TUESDAY NIGHT...ESPECIALLY FOR THE EAST HALF OF THE U.P. AT THIS POINT...WILL STICK WITH CHANCE POPS AT LEAST UNTIL THE SYSTEM IS SAMPLED BETTER OVER THE NEXT FEW DAYS. WEDNESDAY NIGHT AND THURSDAY...BOTH THE EC AND GFS AGREE ON AN UPPER LEVEL TROUGH AXIS ALONG WITH DEEPER MOISTURE LINGERING ACROSS THE AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS. GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 618 AM EST FRI FEB 27 2015 WITH DRY HI PRES DOMINATING...EXPECT VFR CONDITIONS TO PREDOMINATE AT THE TAF SITES THIS FCST PERIOD. NOT OUT OF THE QUESTION THERE COULD BE SOME MVFR CIGS AS DIURNAL CU/SC DEVELOP LATE THIS MRNG/ AFTN...BUT ABSENCE OF THESE CLDS UPSTREAM YDAY...RELATIVELY LO SUBSIDENCE INVRN BASE AND ICE COVER ON LK SUP THAT WL RESTRICT MOISTENING OF THE AIRMASS INDICATE THE CHC IS TOO LO TO INCLUDE IN THE TAFS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 AM EST FRI FEB 27 2015 EXPECT WINDS TO BE UNDER 30 KTS THIS FORECAST PERIOD. LAKE SUPERIOR IS MAINLY ICE COVERED THIS MORNING. ALTHOUGH SHIFTING WINDS UP TO 20 TO 25 KTS ACCOMPANYING THE PASSAGE OF DISTURBANCES THRU THE UPPER LAKES MAY CAUSE HOLES TO OPEN IN THE ICE FROM TIME TO TIME...A CONTINUED DOMINANCE OF ARCTIC AIR WILL MAINTAIN AN OVERALL EXTENSIVE ICE COVER. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
550 AM EST FRI FEB 27 2015 .AVIATION... SURFACE HIGH PRESSURE BUILDING EASTWARD INTO THE REGION WILL CONTINUE TO SUPPORT A VERY DRY AIR MASS. WIND DIRECTIONS ARE FORECASTED TO EMERGE SOUTHWESTERLY TODAY...BRINGING THE POTENTIAL FOR LAKE MICHIGAN MOISTURE TO WORK UNDER THE INVERSION BASE AT 4-5 KFT AGL. MODEL SOUNDINGS ALSO SUPPORT A DIURNAL COMPONTENT TO POTENTIAL CLOUD COVER. DOWNSTREAM TRAJECTORY CONTINUES TO SUPPORT THE BEST POTENTIAL FOR THE NORTHERN TAF SITES. //DTW THRESHOLD PROBABILITIES... * LOW CONFIDENCE IN CEILING BELOW 5000 FT FRIDAY AFTERNOON. && .PREV DISCUSSION...ISSUED 358 AM EST FRI FEB 27 2015 SHORT TERM...TODAY AND TONIGHT RECORD LOWS FOR FEB 27 DETROIT AREA: -4 (1934) FLINT AREA: -14 (1994) SAGINAW: -8 (1934) ANOTHER COLD MORNING ACROSS SOUTHEASTERN MICHIGAN WITH AN ARCTIC SURFACE RIDGE LOCKED IN OVERHEAD. NIL WIND AND CLEAR SKIES HAS LED TO FAVORABLE RADIATIVE COOLING CONDITIONS. SURFACE TEMPERATURES CURRENTLY RANGE FROM 0 TO 10 DEGREES BELOW ZERO AS OF 3AM. WITH A LACK OF LOW CLOUD DISCERNIBLE IN IR IMAGERY...EXPECTATIONS ARE FOR SURFACE TEMPERATURES TO CONTINUE TO BOTTOM OUT BEFORE SUNRISE WITH MANY RURAL LOCATIONS REACHING 10 TO 20 DEGREES BELOW ZERO. WITH A DECOUPLED SURFACE LAYER...WILL HONOR THE DECISION OF PRIOR SHIFTS AND NOT ISSUE A WIND CHILL ADVISORY. COLDEST MIDLEVEL TEMPERATURES PUSHING OUT OF THE STATE TODAY IN COMBINATION WITH AN SURFACE ANTICYCLONE PUSHING INTO PORTIONS OF OHIO WILL ALLOW WIND DIRECTIONS OVER SOUTHEASTERN MICHIGAN TO MAKE A CONCERTED MOVE TO SOUTHWESTERLY. ENHANCED MOISTURE AND LAKE MICHIGAN CLOUD DEBRIS IS PROGGED TO STREAM EASTWARD WITH TIME...SHOWN TO SLIDE THROUGH PORTIONS OF THE CWA BY THIS AFTERNOON AND INTO THE EARLY EVENING. RAP SOUNDINGS SUGGEST THERE WILL BE A CONSIDERABLE DIURNAL COMPONENT TO ANY SKY COVER. WIND TRAJECTORIES POINT TO THE NORTHERN CWA/SAGAINAW VALLEY AS THE MORE FAVORABLE LOCATION FOR CLOUDS. WITH SUN...SHADED A DEGREE OR TWO HIGHER THAN MOS GUIDANCE FOR HIGHS. SURFACE HIGH PRESSURE PUSHING THROUGH INDIANA AND OHIO WILL SET ANOTHER NIGHT UP FOR CALM WINDS ACROSS THE SOUTHERN HALF OF THE CWA. LOWERED MINS FOR AREAS SOUTH OF DETROIT. OTHERWISE...A PRESSURE GRADIENT IN PLACE OVER THE TRI CITIES/NORTHERN THUMB AND SOME POTENTIAL FOR LINGERING CLOUDS LIMITS THE TEMPERATURE FALL POTENTIAL FOR TONIGHT. LONG TERM... COLD AIRMASS WILL REMAIN IN PLACE INTO EARLY THIS WEEKEND ALTHOUGH TEMPERATURES WILL MODERATE EVER SO SLIGHTLY AS THE LATEST ARCTIC HIGH PRESSURE SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT. HIGHS ON SATURDAY WILL CLIMB TO AROUND 20F WITH LOWS THAT NIGHT HOLDING INTO THE SINGLE DIGITS TO NEAR 10F AS BOTH THE COLDEST AIR SHIFTS EAST AND EXPANDING CLOUD COVER WORKS INTO THE AREA WITH THE APPROACH OF A LOW PRESSURE SYSTEM. 00Z MODEL RUNS...SAVE THE NAM12...BASICALLY SUPPORT THE PREVIOUS FORECAST AS ROUGHLY 1 TO 2 INCHES OF SNOW FALL FROM THE I-69 CORRIDOR NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY EVENING WITH 2 TO 3 INCHES SOUTH OF THAT INTO METRO DETROIT AS H7 SPECIFIC HUMIDITY CLIMBS TO AROUND 2 G/KG ALONG THE M-59 CORRIDOR. GIVEN THE RELATIVELY HIGH SNOW TO LIQUID RATIOS EXPECTED WITH THE COLD AIRMASS IN PLACE...15:1 OR A BIT MORE...WOULD NOT BE SURPRISED TO SEE UP TO 4 INCHES FROM THE I-94 CORRIDOR SOUTHWARD. TEMPERATURES WILL EDGE BACK DOWN EARLY NEXT WEEK...BUT TO MUCH MORE REASONABLE LEVELS THAN THE PAST SEVERAL WEEKS AS HIGHS MONDAY REACH THE MID/UPPER 20S AND LOWS HOLD IN THE TEENS SUNDAY AND MONDAY NIGHT. THE NEXT LOW PRESSURE SYSTEM APPEARS TO BE SHAPING UP TO BE A STRONGER SYSTEM THAN THE WEEKEND EVENT...WITH A TRACK THAT WOULD SUPPORT A WIDE VARIETY OF PRECIPITATION ACROSS THE CWA ON TUESDAY WITH PRIMARILY SNOW OVER THE NORTHERN CWA AND SNOW CHANGING TO A MIX AND THEN EVENTUALLY RAIN FURTHER SOUTH. WITH THE EVENTUAL TRACK AND STRENGTH OF THIS SYSTEM STILL IN DOUBT...WILL FORGO ANY SIGNIFICANT DETAILS AT THIS TIME...OTHER THAN TO INCLUDE SOME MENTION OF SLEET...FREEZING RAIN AND RAIN AS 00Z RUNS OF THE GFS...CMC AND ECMWF DO NOT SUPPORT AN ALL SNOW EVENT FOR THE ENTIRE CWA. MARINE... HIGH PRESSURE WILL BE BUILD FROM THE MID MISSISSIPPI VALLEY TODAY THROUGH THE OHIO VALLEY ON SATURDAY. MODEST SOUTHWEST RETURN FLOW WILL DEVELOP AROUND THIS HIGH OVER THE CENTRAL GREAT LAKES. CENTRAL SECTIONS OF LAKE HURON WILL MOST LIKELY SEE WINDS INCREASE INTO THE 15 TO 20 KNOT RANGE. OTHERWISE...WINDS WILL REMAIN ON THE LIGHT SIDE AS THIS SOUTHWEST PRESSURE GRADIENT WEAKENS LATE IN THE WEEKEND AS A WEAK LOW PRESSURE SYSTEM LIFTS INTO THE REGION. EVEN THE RETURN OF COLD NORTHWEST FLOW IN THE WAKE OF THE ATTENDING COLD FRONT WILL BE LIMITED TO 25 KNOT GUSTS OR LESS OVER MUCH OF LAKE HURON. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....99 SHORT TERM...CB LONG TERM....DG MARINE.......DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
403 AM EST FRI FEB 27 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 402 AM EST FRI FEB 27 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT OVER THE UPR GREAT LKS TO THE SW OF CLOSED H5 LO OVER NRN QUEBEC. SHRTWV RDG AXIS STRETCHING FM THE NRN PLAINS INTO NW ONTARIO IS SUPPORTING A SFC HI PRES STRETCHING FM THE NRN PLAINS INTO IOWA. UPR MI IS DOMINATED BY A DRY WNW LLVL FLOW E OF THIS HI CENTER /00Z PWATS UPSTREAM ARE GENERALLY 0.05 TO 0.10 INCH...NO MORE THAN 50 PCT OF NORMAL/. COMBINATION OF THE DRYNESS OF THE UPSTREAM AIRMASS...00Z INL AND YPL RAOBS SHOW AN INVERTED V T/TD PROFILE BLO SUBSIDENCE INVRN NEAR H9...AND EXTENSIVE ICE COVER OVER LK SUP HAS GREATLY DIMINISHED THE LES. IN FACT...IR STLT IMAGERY SHOWS ONLY PATCHY LK CLDS STREAMING INTO AREAS E OF MUNISING. 00Z H85 TEMPS OVER THE AREA RANGE FM -23C AT GRB TO -19C AT INL/YPL AND THEN UP TO -16C AT THE PAS MANITOBA. UNDER THE MOCLR SKIES/DRY ARCTIC AIRMASS...TEMPS HAVE FALLEN WELL BLO ZERO OVER THE INTERIOR AND AS LO AS -25F TO -30F AT THE MORE SHELTERED RURAL SPOTS. WINDS ARE STIRRING A BIT MORE NEAR LK SUP UNDER A TIGHTER PRES GRADIENT...AND SOME OF THE MORE EXPOSED LOCATIONS THERE ARE INDICATING WIND CHILLS AS LO AS -25F. MAIN FCST CONCERNS THRU TNGT WL BE ON TEMPS. OPTED TO ISSUE AN SPS TO COVER WIND CHILLS NEAR ADVY CRITERIA AT THE MORE EXPOSED LOCATIONS NEAR LK SUP THIS MRNG. TODAY...AS SHRTWV RDG TO THE NW SLIDES TO THE SE...SFC HI PRES CENTER IS FCST TO SHIFT TO INDIANA/ILLINOIS BY 00Z SAT. THE COMBINATION OF ONGOING SUBSIDENCE AHEAD OF THE SHRTWV RDG AND SOME WAA AS THE SFC-H925 FLOW BACKS TO THE WSW...IS FCST TO RAISE H85 TEMPS UP TO -16 TO -17C BY THE END OF THE DAY. GIVEN ABSENCE OF MUCH DIURNAL CU UPSTREAM YDAY AND LARGER SCALE SUBSIDENCE/WRMG AT H85... SUSPECT THERE WL ONLY BE SOME SCT DIURNAL CLDS OVER THE INTERIOR THIS AFTN. AS THE FLOW BACKS...LINGERING LK CLDS/ANY FLURRIES E OF MUNISING THIS MRNG SHOULD SHIFT OUT OVER LK SUP IN THE AFTN. WITH A GOOD DEAL OF SUNSHINE...GOING FCST HI TEMPS RECOVERING INTO THE TEENS APPEAR TO BE ON TRACK. TNGT...SFC HI PRES IS FCST TO SLIDE INTO THE MID ATLANTIC STATES BY 12Z SUN...WITH STEADY WSW WIND REMAINING IN PLACE UNDER THE TIGHT PRES GRADIENT TO THE NW OF THIS FEATURE. ALOFT...UPR MI BE UNDER CONTINUED SUBSIDENCE AHEAD OF ANOTHER SHRTWV RDG APRCHG FM THE W. WITH A CONTINUED SLOW WARMING OF THE H85 TEMPS...AN ABSENCE OF ANY SGNFT LLVL MSTR INFLOW AND GENERALY ACYC NATURE OF THE W FLOW...LK CLDS OVER THE KEWEENAW SHOULD BE SCT AT BEST. ANY LK CLDS/LES OVER THE E HALF OF THE LK SHOULD REMAIN OFFSHORE. PWAT IS FCST TO BE AOB 0.10 INCH...SO TENDED TO GO AOB THE LO END OF GUIDANCE FOR MIN TEMPS /AS IS OBSVD THIS MRNG/ IN AREAS AWAY FM LK SUP...WHERE A STEADIER WIND SHOULD LIMIT THE DIURNAL TEMP DROP. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 402 AM EST FRI FEB 27 2015 SATURDAY INTO SATURDAY NIGHT...A BROAD SURFACE HIGH PRESSURE SYSTEM OVER MUCH OF THE GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH THE DAY SATURDAY. THIS WILL KEEP FAIRLY DRY AIR IN PLACE ALLOWING MOST AREAS OF THE U.P. TO SEE SUNNY SKIES THROUGH THE DAY SATURDAY. BY SATURDAY NIGHT...THE HIGH PRESSURE CENTER WILL SHIFT EASTWARD STRETCHING FROM THE NORTHEAST U.S. SOUTHWARD ALONG THE EASTERN SEABOARD. AT THIS HAPPENS...A WEAK SURFACE TROUGH/COLD FRONT WILL APPROACH THE AREA FROM THE WEST. OVERALL MOISTURE APPEARS TO BE LIMITED AND FOCUSED MAINLY TO THE SOUTH OF THE U.P. THEREFORE...ONLY EXPECTING AN INCREASE IN CLOUD COVER SATURDAY NIGHT WITH ONLY A SMALL CHANCE OF LIGHT SNOW ACROSS THE U.P. WITH LIMITED/WEAK FORCING. SUNDAY THROUGH MONDAY...THE SURFACE TROUGH/WEAK COLD FRONT WILL CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE UPPER PENINSULA THROUGH THE DAY SUNDAY. AGAIN...MOISTURE WILL BE LIMITED ALONG THE FRONT WITH CONTINUED WEAK FORCING. ONLY LIGHT SNOW IS EXPECTED THROUGH THE DAY SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB TROUGH IS POISED TO SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS HAPPENS...ENOUGH MOISTURE WILL REMAIN IN PLACE WITH VERY SLIGHT ADDITIONAL MOISTURE ADDED FROM THE ICE COVER LAKE SUPERIOR TO ALLOW A CHANCE OF LAKE EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO NORTHWEST WIND FAVORED LOCATIONS. DELTA T VALUES WILL BE SUFFICIENT FOR LAKE EFFECT WITH THE TROUGH AXIS SLIDING ACROSS...BUT LAKE EFFECT INTENSITY WILL BE LIMITED TO AREAS THAT ANY BREAKS IN THE ICE COVER OCCURS. ANY LAKE EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT WILL BE SHORT LIVED AS MUCH DRIER AIR AND HIGH PRESSURE AT THE SURFACE AND SLIGHT RIDGING ALOFT TO PUSH INTO THE UPPER GREAT LAKES REGION DURING THE DAY MONDAY. THIS WILL FOR MAINLY SUNNY SKIES DURING THE DAY MONDAY. MONDAY NIGHT THROUGH WEDNESDAY...THE AFOREMENTIONED HIGH PRESSURE SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES...THEN THE EASTERN SEABOARD MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST SOUTHERLY FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE U.S. ADDITIONALLY...ANOTHER STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. THERE ARE MODEL DIFFERENCES WITH THE PHASING OF THE TWO SYSTEMS. THE 18Z/26 00Z/27 GFS IS MORE PROGRESSIVE WITH BOTH SYSTEMS AND THE PHASING OF THE SYSTEMS. THIS WOULD PUSH SNOW INTO THE AREA AS EARLY AS MONDAY EVENING ON ISENTROPIC UPGLIDE AND INCREASED MOISTURE IN THE AREA. THE EC 12/26 00Z/27 IS MUCH SLOWER WITH THE PHASING...KEEPING THE PRECIPITATION OUT OF THE AREA UNTIL LATE MONDAY NIGHT INTO TUESDAY MORNING. THE BEST CHANCES GIVEN THE OVERLAP OF THE TWO MODEL SOLUTIONS WOULD BE TUESDAY AFTERNOON INTO TUESDAY NIGHT...ESPECIALLY FOR THE EAST HALF OF THE U.P. AT THIS POINT...WILL STICK WITH CHANCE POPS AT LEAST UNTIL THE SYSTEM IS SAMPLED BETTER OVER THE NEXT FEW DAYS. WEDNESDAY NIGHT AND THURSDAY...BOTH THE EC AND GFS AGREE ON AN UPPER LEVEL TROUGH AXIS ALONG WITH DEEPER MOISTURE LINGERING ACROSS THE AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS. GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1200 AM EST FRI FEB 27 2015 WEST FLOW COMBINED WITH ICE COVERED LAKE SUPERIOR IS PROHIBITING LAKE CLOUDS TONIGHT AT THE TAF SITES. EXPECT THIS TO CONTINUE THROUGH MUCH OF THE TAF PD. THERE IS A CHANCE FOR SOME DIURNAL MVFR CLOUDS TO FORM AT KSAW DURING THE DAY ON FRI. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 AM EST FRI FEB 27 2015 EXPECT WINDS TO BE UNDER 30 KTS THIS FORECAST PERIOD. LAKE SUPERIOR IS MAINLY ICE COVERED THIS MORNING. ALTHOUGH SHIFTING WINDS UP TO 20 TO 25 KTS ACCOMPANYING THE PASSAGE OF DISTURBANCES THRU THE UPPER LAKES MAY CAUSE HOLES TO OPEN IN THE ICE FROM TIME TO TIME...A CONTINUED DOMINANCE OF ARCTIC AIR WILL MAINTAIN AN OVERALL EXTENSIVE ICE COVER. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
358 AM EST FRI FEB 27 2015 .SHORT TERM...TODAY AND TONIGHT RECORD LOWS FOR FEB 27 DETROIT AREA: -4 (1934) FLINT AREA: -14 (1994) SAGINAW: -8 (1934) ANOTHER COLD MORNING ACROSS SOUTHEASTERN MICHIGAN WITH AN ARCTIC SURFACE RIDGE LOCKED IN OVERHEAD. NIL WIND AND CLEAR SKIES HAS LED TO FAVORABLE RADIATIVE COOLING CONDITIONS. SURFACE TEMPERATURES CURRENTLY RANGE FROM 0 TO 10 DEGREES BELOW ZERO AS OF 3AM. WITH A LACK OF LOW CLOUD DISCERNIBLE IN IR IMAGERY...EXPECTATIONS ARE FOR SURFACE TEMPERATURES TO CONTINUE TO BOTTOM OUT BEFORE SUNRISE WITH MANY RURAL LOCATIONS REACHING 10 TO 20 DEGREES BELOW ZERO. WITH A DECOUPLED SURFACE LAYER...WILL HONOR THE DECISION OF PRIOR SHIFTS AND NOT ISSUE A WIND CHILL ADVISORY. COLDEST MIDLEVEL TEMPERATURES PUSHING OUT OF THE STATE TODAY IN COMBINATION WITH AN SURFACE ANTICYCLONE PUSHING INTO PORTIONS OF OHIO WILL ALLOW WIND DIRECTIONS OVER SOUTHEASTERN MICHIGAN TO MAKE A CONCERTED MOVE TO SOUTHWESTERLY. ENHANCED MOISTURE AND LAKE MICHIGAN CLOUD DEBRIS IS PROGGED TO STREAM EASTWARD WITH TIME...SHOWN TO SLIDE THROUGH PORTIONS OF THE CWA BY THIS AFTERNOON AND INTO THE EARLY EVENING. RAP SOUNDINGS SUGGEST THERE WILL BE A CONSIDERABLE DIURNAL COMPONENT TO ANY SKY COVER. WIND TRAJECTORIES POINT TO THE NORTHERN CWA/SAGAINAW VALLEY AS THE MORE FAVORABLE LOCATION FOR CLOUDS. WITH SUN...SHADED A DEGREE OR TWO HIGHER THAN MOS GUIDANCE FOR HIGHS. SURFACE HIGH PRESSURE PUSHING THROUGH INDIANA AND OHIO WILL SET ANOTHER NIGHT UP FOR CALM WINDS ACROSS THE SOUTHERN HALF OF THE CWA. LOWERED MINS FOR AREAS SOUTH OF DETROIT. OTHERWISE...A PRESSURE GRADIENT IN PLACE OVER THE TRI CITIES/NORTHERN THUMB AND SOME POTENTIAL FOR LINGERING CLOUDS LIMITS THE TEMPERATURE FALL POTENTIAL FOR TONIGHT. && .LONG TERM... COLD AIRMASS WILL REMAIN IN PLACE INTO EARLY THIS WEEKEND ALTHOUGH TEMPERATURES WILL MODERATE EVER SO SLIGHTLY AS THE LATEST ARCTIC HIGH PRESSURE SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT. HIGHS ON SATURDAY WILL CLIMB TO AROUND 20F WITH LOWS THAT NIGHT HOLDING INTO THE SINGLE DIGITS TO NEAR 10F AS BOTH THE COLDEST AIR SHIFTS EAST AND EXPANDING CLOUD COVER WORKS INTO THE AREA WITH THE APPROACH OF A LOW PRESSURE SYSTEM. 00Z MODEL RUNS...SAVE THE NAM12...BASICALLY SUPPORT THE PREVIOUS FORECAST AS ROUGHLY 1 TO 2 INCHES OF SNOW FALL FROM THE I-69 CORRIDOR NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY EVENING WITH 2 TO 3 INCHES SOUTH OF THAT INTO METRO DETROIT AS H7 SPECIFIC HUMIDITY CLIMBS TO AROUND 2 G/KG ALONG THE M-59 CORRIDOR. GIVEN THE RELATIVELY HIGH SNOW TO LIQUID RATIOS EXPECTED WITH THE COLD AIRMASS IN PLACE...15:1 OR A BIT MORE...WOULD NOT BE SURPRISED TO SEE UP TO 4 INCHES FROM THE I-94 CORRIDOR SOUTHWARD. TEMPERATURES WILL EDGE BACK DOWN EARLY NEXT WEEK...BUT TO MUCH MORE REASONABLE LEVELS THAN THE PAST SEVERAL WEEKS AS HIGHS MONDAY REACH THE MID/UPPER 20S AND LOWS HOLD IN THE TEENS SUNDAY AND MONDAY NIGHT. THE NEXT LOW PRESSURE SYSTEM APPEARS TO BE SHAPING UP TO BE A STRONGER SYSTEM THAN THE WEEKEND EVENT...WITH A TRACK THAT WOULD SUPPORT A WIDE VARIETY OF PRECIPITATION ACROSS THE CWA ON TUESDAY WITH PRIMARILY SNOW OVER THE NORTHERN CWA AND SNOW CHANGING TO A MIX AND THEN EVENTUALLY RAIN FURTHER SOUTH. WITH THE EVENTUAL TRACK AND STRENGTH OF THIS SYSTEM STILL IN DOUBT...WILL FORGO ANY SIGNIFICANT DETAILS AT THIS TIME...OTHER THAN TO INCLUDE SOME MENTION OF SLEET...FREEZING RAIN AND RAIN AS 00Z RUNS OF THE GFS...CMC AND ECMWF DO NOT SUPPORT AN ALL SNOW EVENT FOR THE ENTIRE CWA. && .MARINE... HIGH PRESSURE WILL BE BUILD FROM THE MID MISSISSIPPI VALLEY TODAY THROUGH THE OHIO VALLEY ON SATURDAY. MODEST SOUTHWEST RETURN FLOW WILL DEVELOP AROUND THIS HIGH OVER THE CENTRAL GREAT LAKES. CENTRAL SECTIONS OF LAKE HURON WILL MOST LIKELY SEE WINDS INCREASE INTO THE 15 TO 20 KNOT RANGE. OTHERWISE...WINDS WILL REMAIN ON THE LIGHT SIDE AS THIS SOUTHWEST PRESSURE GRADIENT WEAKENS LATE IN THE WEEKEND AS A WEAK LOW PRESSURE SYSTEM LIFTS INTO THE REGION. EVEN THE RETURN OF COLD NORTHWEST FLOW IN THE WAKE OF THE ATTENDING COLD FRONT WILL BE LIMITED TO 25 KNOT GUSTS OR LESS OVER MUCH OF LAKE HURON. && .AVIATION...ISSUED 1153 PM EST THU FEB 26 2015 EXISTING ARCTIC HIGH PRESSURE WILL LARGELY SUSTAIN A DRY/STABLE ENVIRONMENT INTO FRIDAY. SOME THIN POCKETS OF STRATUS NOTED DEVELOPING IN THE VICINITY OF MBS MAY PROVIDE A BRIEF MVFR CEILING EARLY THIS MORNING AT MBS/FNT...BUT LIMITED COVERAGE AND DURATION WILL SUPPORT A PREVAILING VFR. A BACKING FLOW TOWARD THE WEST AND THEN SOUTHWEST WILL SUPPORT A PERIOD OF LOW VFR DIURNAL STRATO CU DEVELOPMENT FRIDAY AFTERNOON...GREATER COVERAGE SEEMINGLY MORE LIKELY ACROSS THE NORTHERN TAF SITES. //DTW THRESHOLD PROBABILITIES... * LOW CONFIDENCE IN CEILING BELOW 5000 FT FRIDAY AFTERNOON. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...CB LONG TERM....DG MARINE.......DG AVIATION.....MR YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
916 PM CST SAT FEB 28 2015 .UPDATE...SURFACE ANALYSIS AT 02Z SHOWING STATIONARY BOUNDARY EXTENDING FROM KESF-KTVR-KMKL. TEMPS GENERALLY IN THE 50S ON THE EAST SIDE WITH 40S ON THE WEST. NO REAL PUSH SEEM WITH SURFACE WINDS NOR WINDS ALOFT AS THEY ARE ALL PARALLEL TO THE BOUNDARY. WHILE WEAK ISENTROPIC ASCENT IS RESULTING IN SOME LIGHT PRECIP IN AR/W LA/E TX...DECIDED TO HOLD OFF ON POPS IN THE FAR WEST AS 00Z JAN UA SOUNDING IS SHOWING A VERY DRY AIRMASS BELOW 750 MB. LIGHT PRECIP WOULD HAVE TO FALL THROUGH THIS LAYER A WHILE BEFORE ANY COULD REACH GROUND. ANOTHER FEATURE TO NOTE THIS EVENING...OBSERVATIONS ARE SHOWING A WESTWARD SURGE IN DEWPOINTS OVER S AL. HRRR HAS PICKED UP ON THIS AND IS SHOWING TEMPS RISE OVERNIGHT IN EAST MS AS THIS MOISTURE MOVES IN./26/ && .AVIATION...CIGS/VSBY WILL STEADILY LOWER TO MVFR OVERNIGHT AS MOISTURE INCREASES FROM THE EAST. CIGS WILL EVENTUALLY BECOME IFR AFTER 12Z AS AREAS OF LIGHT RAIN SPREAD OVER THE REGION./26/ && .PREV DISCUSSION... /ISSUED 423 PM CST SAT FEB 28 2015/ DISCUSSION...IT TURNED OUT TO BE QUITE A NICE DAY ACROSS THE ARKLAMISS REGION FOR THE LAST DAY OF METEOROLOGICAL WINTER. WHILE THERE HAVE BEEN SOME HIGH CLOUDS PRESENT...THERE HAS BEEN ENOUGH SUN TO ALLOW TEMPERATURES TO REALLY WARM UP GENERALLY ALONG AND SOUTH OF THE NATCHEZ TRACE CORRIDOR. READINGS HAVE REACHED INTO THE MID 60S IN THIS REGION WHERE AS TEMPERATURES IN THE DELTA REMAIN IN THE UPPER 40S THANKS IN PART TO THOSE CLOUDS. NEVERTHELESS...3PM TEMPERATURES ARE ABOUT 15 TO 20 DEGREES WARMER THAN THIS TIME YESTERDAY AND THIS IS WELCOME FOR MANY ACROSS THE ARKLAMISS. WINDS HAVE SHIFTED AROUND OUT OF THE SOUTH/SOUTHEAST WHICH IS HELPING TO WARM TEMPERATURES AND WILL BEGIN TO INCREASE MOISTURE ACROSS THE REGION. THE UPCOMING WEEK WILL START OFF ON THE WARMER SIDE BUT HAVE CHANCES FOR RAIN THROUGH THE FIRST FEW DAYS. THEN ANOTHER DRASTIC CHANGE WILL OCCUR AND ANOTHER ROUND OF WINTRY PRECIPITATION NOW LOOKS POSSIBLE DURING MID-WEEK. AS MOISTURE STARTS TO RETURN TO THE REGION THIS WILL LEAD TO SOME SHOWERS LATE TONIGHT IN THE WEST...SPREADING EAST THROUGH THE DAY SUNDAY. THIS RAIN WILL CONTINUE INTO MONDAY WITH THE HIGHEST CHANCES BEING ALONG THE HIGHWAY 82 CORRIDOR. ANOTHER WEAK COLD FRONT WILL DROP INTO THE REGION ON MONDAY BUT SHOULD STALL GENERALLY ALONG OR JUST SOUTH OF THE I-20 CORRIDOR. THIS WILL BRING SOME COOLER TEMPERATURES TO THE REGION ON MONDAY ALONG WITH CONTINUED CHANCES FOR RAIN. HOWEVER...LOCATIONS SOUTH OF THE FRONT SHOULD STILL SEE READINGS INTO THE LOWER TO MID 60S. THIS FRONT WILL RETURN NORTH AS A WARM FRONT MONDAY NIGHT...SHIFTING THE BULK OF THE RAIN NORTH OF THE CWA INTO NORTHERN MISSISSIPPI. THIS WILL LEAVE THE ENTIRE ARKLAMISS REGION INTO THE WARM SECTOR. MONDAY NIGHT SHOULD BE ONE OF THOSE SCENARIOS THANKS TO THE NORTHWARD MOVING WARM FRONT WHERE OVERNIGHT TEMPERATURES RISE THROUGH THE NIGHT. TUESDAY WILL BE A VERY WARM DAY ACROSS THE ARKLAMISS THANKS TO UPPER RIDGING OVER THE NORTHERN GULF. HIGHS SHOULD REACH INTO THE 70S AND I ACTUALLY WENT HIGHER THAN WHAT GUIDANCE WAS GIVING ME FOR HIGHS THAT DAY. TUESDAY NIGHT THE STRONG COLD FRONT WILL APPROACH THE REGION. THERE COULD BE SOME THUNDERSTORMS ACCOMPANYING THE FRONT BUT OVERALL SHOWALTER INDICES ARE NOT VERY NEGATIVE AND INSTABILITY OTHERWISE IS A LITTLE LOW. HAVE KEPT MOSTLY SHOWERS WITH SOME CHANCES FOR THUNDER. THE COLD FRONT WILL SWEEP INTO THE REGION ON WEDNESDAY WITH CHANCES FOR SHOWERS ALONG AND BEHIND THE FRONT. MODELS HAVE CONTINUED TO TREND A BIT COLDER WITH THIS SYSTEM AND ARE IN GOOD AGREEMENT OF SOME POTENTIAL OF WINTRY PRECIPITATION AFFECTING AT LEAST THE NORTHERN PORTIONS OF THE ARKLAMISS STARTING WEDNESDAY AFTERNOON INTO THURSDAY. WHILE THERE CONTINUES TO BE HIGH PROBABILITIES OF PRECIPITATION THERE IS SLIGHTLY LOWER CONFIDENCE IN THE PRECIPITATION TYPE THAT WILL OCCUR. AT THIS TIME...GLOBAL MODELS AND MODEL BUFR SOUNDINGS INDICATE THAT DURING WEDNESDAY AFTERNOON THE RAIN SHOULD CHANGE OVER TO FREEZING RAIN AS THE COLDER AIR SINKS SOUTH INTO THE REGION...WITH THE BEST CHANCES OF THIS OCCURRING ACROSS NORTHERN SECTIONS OF THE CWA/MISSISSIPPI DELTA. THEN SOMETIME LATER INTO THE EVENING THERE COULD BE A CHANGEOVER TO SNOW ASSUMING THERE IS ENOUGH PRECIPITATION LINGERING FOR THAT TO OCCUR. FURTHER SOUTH...THERE IS LOWER CONFIDENCE AT THIS TIME DESPITE THE BULLISH NATURE OF THE GFS IN BRINGING THE COLDER AIR SURGING SOUTH DURING THE TIME OF PRECIPITATION. THIS IS OF COURSE SOMETHING THAT WE WILL KEEP MONITORING WITH LATER MODEL RUNS. WE HAVE THOUGH INCLUDED MENTION OF THIS IN THE HWO AND GRAPHICS FOR WEDNESDAY INTO THURSDAY. BY THURSDAY AFTERNOON THE PRECIPITATION WILL HAVE EXITED TO THE EAST LEAVING THE REGION UNDER COLD HIGH PRESSURE. SO MUCH FOR THE START TO METEOROLOGICAL SPRING...WE WILL STILL BE FEELING THE GRIPS OF WINTER. /28/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 46 63 50 57 / 8 46 60 82 MERIDIAN 47 63 48 57 / 8 18 52 74 VICKSBURG 41 63 49 54 / 8 76 69 85 HATTIESBURG 48 67 52 67 / 8 16 30 49 NATCHEZ 49 64 54 59 / 8 65 58 62 GREENVILLE 33 53 41 46 / 8 85 86 92 GREENWOOD 43 57 44 49 / 8 77 89 93 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
635 PM CST Sat Feb 28 2015 ...Winter Weather Advisory Upgraded to a Winter Storm Warning for Portions of the Ozarks... .UPDATE... Issued at 619 PM CST SAT FEB 28 2015 Calls around and social media reports indicate that 4-5" of snow has now fallen along and north of the I-44 corridor and along and east of the U.S. 65 corridor. The snow has started accumulating much more efficiently with the setting sun. With the back edge of the most organized precipitation just now getting to the KS/MO line, we still think another 1-3" of snow will fall...especially along and north of the Ozark Plateau and east of U.S. 65. With that being said, we have upgraded to a Winter Storm Warning from Polk and Greene Counties...northeast into the Lake of the Ozarks and Salem region. While snow will become lighter from west to east later this evening, we are expecting the potential for a light wintry mix overnight and into Sunday morning. Radar and satellite trends as well as observations indicate freezing drizzle, very light freezing rain, and even some light sleet pushing in from eastern Oklahoma and Kansas. Minor ice accumulations will therefore be left in the forecast as we head into later tonight and Sunday morning. && .SHORT TERM...(This Evening through Sunday Night) Issued at 307 PM CST SAT FEB 28 2015 A large area of snow has blanketed all of the Missouri Ozarks and extreme southeastern Kansas as of mid afternoon. Visibilities were pretty much below one mile over all areas...with occasional observations indicating quarter mile visibilities with heavy snow. Snowfall accumulations up through 3 PM have been in the 1-3" range. We suspect that some locations across extreme southeastern Kansas and west-central Missouri may be in that 3-4" range. As we head into late this afternoon and this evening, short term models are beginning to change their tune a bit. Both the RAP and the HRRR have somewhat backed off on a secondary band of snow developing along the I-44 corridor this evening. Even the 18Z NAM has trended this way. Instead, models gradually take the large area of moderate to occasionally heavy snow to the east and northeast with the back edge of the heavier snow moving east across the Ozarks this evening. This would tend to make sense as low level isentropic upglide and a weak upper level jet coupling structure shift towards the Mid Mississippi Valley. We will still have to watch for some banding of snow as models do indicate some slugs of increased 700 mb frontogenesis...especially along and north of the I-44 corridor. As we head into later tonight, the main area of snow will have shifted east of the area. Pockets of light snow and flurries will be left in its wake. While snow intensity will be on the downward trend this evening (again from west to east), it will tend to accumulate more efficiently given that the sun will have set. Models are also indicating perhaps some loss of cloud ice later tonight. Additionally, models still bring a warm nose into southern Missouri by late tonight. Thus, we are continuing a mention of either light freezing rain or freezing drizzle. This trend will then continue into Sunday morning with pockets of light snow and drizzle/freezing drizzle. We have slowed the progress of the surface freezing line to the north by a few hours...which does keep the door open a bit longer for minor ice accumulation. One thing we will have to watch very closely is what will be a good setup for a banded snow event from late tonight into Sunday morning up towards I-70. Models continue to indicate strong 700 mb frontogenesis and available negative EPV becoming juxtaposed with a favorable upper level jet streak. If this materializes, it could put down a narrow swath of additional heavier snowfall. While this could glance our central Missouri counties, confidence is higher that it will remain just north of the area. Once we get into Sunday afternoon and especially Sunday night, the primary precipitation will be shifting east and southeast of the region. As for storm total ice and snow amounts, we have not changed much. Any ice accumulations are still expected to remain at or below five-hundredths of an inch. 1-3" of snow is expected across south-central Missouri. Accumulations near and north of the I-44 corridor will be in the 3-6" range. We still think a few isolated reports of around 7" will be possible. Given that any 6-7" amounts are expected to be isolated (if they occur at all), the current Winter Weather Advisory will be left intact. .LONG TERM...(Monday through Saturday) Issued at 307 PM CST SAT FEB 28 2015 By Monday morning, precipitation should push south of the region, at least temporarily, as high pressure noses south from the Dakotas. Highs on Monday look to reach the upper 30s in most locations. Precipitation will then return to the area Monday night into Tuesday, though at this point it appears that temperatures should be above freezing by the time rain begins to fall Monday night. Rain will continue through much of the day Tuesday, as low pressure at the surface deepens and lifts north across Kansas and northern Missouri. Breezy southwest winds during the day Tuesday will help temperatures warm into the low to mid 50s. Will continue to include a mention of thunder in the forecast for Tuesday, with guidance suggesting a couple hundred J/KG of CAPE making its way into the CWA. A strong cold front will then sweep across the area Tuesday afternoon and evening, with colder air quickly advecting into the area Tuesday night. We will need to carefully watch the potential for post frontal snow Tuesday night and Wednesday, as lift from a secondary trough axis may be enough to result in areas of snow on Wednesday. As it stands right now, the highest snow potential for Wednesday looks to be south of I-44, though this will be highly dependent on the eventual location of the front. The upper level flow will then flatten out a bit, with southwesterly flow developing at the surface for the end of the week into next weekend. This is suggestive of warmer temperatures for the end of the week, with highs perhaps (finally) approaching climatological averages by this time next weekend. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Issued at 1149 AM CST SAT FEB 28 2015 IFR and LIFR conditions will continue this afternoon and evening across the region as moderate to at times heavy snow affect the terminals. Prevailing conditions will likely be just above airport minimums at SGF and JLN, but dips to or below mins are likely if/when bands of the heaviest snow move overhead. Snow intensity should decrease somewhat later tonight, though cigs will remain low. A south to north transition to a wintry mix of snow, rain and freezing rain is expected at some point late tonight, with an eventual changeover to just rain around mid day tomorrow as temperatures rise above freezing. While this transition has been indicated in the TAFs, confidence in exact timing is very low. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...WINTER WEATHER ADVISORY until Noon CST Sunday FOR MOZ055-056-066- 067-077-078-088-089-093>098-101>106. WINTER STORM WARNING until Noon CST Sunday FOR MOZ057-058- 068>071-079>083-090>092. KS...WINTER WEATHER ADVISORY until Noon CST Sunday FOR KSZ073-097-101. && $$ UPDATE...Schaumann/Cramer SHORT TERM...Schaumann LONG TERM...Boxell AVIATION...Boxell
AREA FORECAST DISCUSSION
NWS HASTINGS NE
604 PM CST SAT FEB 28 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 333 PM CST SAT FEB 28 2015 ZONAL FLOW REMAINS IN PLACE ACROSS THE REGION THIS AFTERNOON...WITH SATELLITE IMAGERY SHOWING THE SHORTWAVE DISTURBANCE WHICH BROUGHT ACCUMULATING SNOW TO SRN PORTIONS OF THE CWA CONTINUING TO SLIDE EAST THROUGH THE PLAINS. RADAR TRENDS SHOW THE BRUNT OF THE SNOWFALL HAS SHIFTED OFF INTO ERN KS/SERN NEB...WITH JUST SOME LIGHT SNOW/FLURRIES LINGERING ACROSS OUR ERN COUNTIES. REPORTS RECEIVED FROM PORTIONS OF NC KS HAD TOTALS TOPPING OUT AROUND 1.5 INCHES. AT THE SFC...THE CWA REMAINS IN BETWEEN HIGH PRESSURE NOW CENTERED OVER THE NERN CONUS AND LOW PRESSURE OVER THE HIGH PLAINS...KEEPING THOSE SRLY WINDS IN PLACE. TEMPS THIS AFTERNOON GOING PRETTY MUCH AS EXPECTED...WITH 3 PM TEMPS RUNNING THE WHOLE RANGE OF 20S. WITH THE FIRST WAVE SHIFTING EAST THROUGH THE AREA THIS AFTERNOON AND THE CWA SITTING IN A BIT OF A LULL...DECIDED TO KEEP THE EVENING HOURS DRY. DO HAVE POPS RETURNING POST 06Z TONIGHT...WITH THE POTENTIAL FOR A BIT MORE SNOW AS ANOTHER WEAKER SHORTWAVE DISTURBANCE AND THE ENTRANCE REGION OF A 140ISH KT UPPER LEVEL JET STREAK MOVES IN. EVEN THIS CLOSE TO THE POTENTIAL PRECIP...MODELS DO NO AGREE WITH WHAT THE CWA WILL SEE. 4KM AND SREF SHOW CHANCES AFFECTING AREAS SOUTH OF I-80...WHILE OTHERS LIKE THE RAP AND ECMWF SHOW BASICALLY NOTHING. INHERITED FORECAST INCLUDED SOME CHANCE POPS...AND ONLY MADE MINOR ADJUSTMENTS TO THOSE. SHOULD SNOW DEVELOP/MOVE INTO THE CWA...ONLY EXPECTING AN ADDITION FEW TENTHS OF A INCH OF ACCUMULATION. HAVE LINGERING LOW POPS DURING THE MORNING HOURS TOMORROW...WITH DRY CONDITIONS FOR THE AFTERNOON. WHILE PLENTY OF CLOUD COVER IS EXPECTED TONIGHT...WITH TIME TOMORROW SKY COVER SHOULD DIMINISH. WITH THIS DISTURBANCE MOVING THROUGH LATE TONIGHT/EARLY TOMORROW...EXPECTING A SWITCH IN WINDS TO THE NORTHWEST ACCOMPANYING A FRONTAL BOUNDARY. DID BUMP UP HIGHS A FEW DEGREES...AS MODELS SHOW SLIGHTLY WARMING TEMPS ALOFT WORKING IN THROUGH THE DAY WITH THOSE NWRLY WINDS /ALTHOUGH THEY ARE ONLY AROUND 10 MPH/. HIGHS CURRENTLY FORECAST TO REACH INTO THE MID 30S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 333 PM CST SAT FEB 28 2015 MAIN CHALLENGE WILL BE DETERMINING CHANCES OF PRECIPITATION LATE SUNDAY NIGHT THROUGH TUESDAY NIGHT AND PRECIPITATION TYPE LATE MONDAY NIGHT INTO TUESDAY MORNING. NUMERICAL MODELS AGREE QUITE WELL WITH SYNOPTIC FEATURES. A DEEP TROUGH IN THE WEST WILL CONTINUE TO APPROACH THE PLAINS FOR THE FIRST PART OF THE EXTENDED FORECAST. WHILE IN SOUTHWEST FLOW...THERE COULD BE GENERALLY LOW CHANCES OF PRECIPITATION AS LOW AMPLITUDE WAVES ARE KICKED OUT OF THE BASE OF THE TROUGH. NOT UNTIL THE TROUGH MAKES ITS WAY INTO AND EAST OF THE GREAT PLAINS WILL BE SHUT OFF THE POTENTIAL FOR PRECIPITATION. THE SPECIFICS AND TIMING ARE FAR FROM AGREED UPON BETWEEN NUMERICAL MODELS. GENERALLY NEED TO GO WITH LOW CHANCES FOR MOST OF THE FIRST HALF OF THE LONG TERM FORECAST TO ESSENTIALLY COVER OUR BASES. CONFIDENCE IS RATHER LOW REGARDING TIMING OF ANY LULLS ALONG WITH PRECIPITATION AS BOUTS OF SNOW MAY BE RELATIVELY SHORT LIVED. THE NAM INDICATES ISENTROPIC LIFT FOR MONDAY...GIVING US A SHOT AT SOME RAIN/SNOW. BOTH THE NAM AND GFS INDICATE CONTINUED ISENTROPIC LIFT TOWARD LATE MONDAY NIGHT...BUT THE NAM INDICATES A LOSS OF SATURATION IN THE DENDRITIC GROWTH ZONE...SO THERE COULD BE A SHORT PERIOD OF FREEZING DRIZZLE BEFORE ISENTROPIC DOWNGLIDE ENSUES. STILL...THERE IS SO MUCH INCONSISTENCY AND LACK OF AGREEMENT...I CONTINUE TO BE QUITE SKEPTICAL OF THIS...SO I WILL PROBABLY CONTINUE TO LEAVE THIS OUT OF THE FORECAST FOR NOW AND STICK WITH SNOW. ANOTHER THING TO KEEP AN EYE ON IS WIND SPEED IN COMBINATION WITH SNOW FALLING FOR TUESDAY BEHIND A COLD FRONT. NORTHWEST WINDS AT 30 MPH GUSTING TO 40 MPH ARE EXPECTED...AND WITH UP TO 2 INCHES OF SNOWFALL...WE COULD EASILY HAVE REDUCED VISIBILITY. WIND CHILLS ON WEDNESDAY MORNING DID NOT DIP QUITE LOW ENOUGH TO MENTION IN THE HWO. ONCE WE GET THE TROUGH EAST OF US...WE WILL BE MORE CONFIDENTLY DRY AND EVENTUALLY WARM UP TOWARD NEXT WEEKEND...MAYBE EVEN NEAR OR ABOVE NORMAL FOR A CHANGE AS A RIDGE IN THE WEST NUDGES EAST. && .AVIATION...(FOR THE 00Z KGRI/KEAR TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 543 PM CST SAT FEB 28 2015 THE WIND WILL BECOME LIGHT TONIGHT AND GRADUALLY SHIFT FROM SOUTH SOUTHWEST TO WESTERLY BY DAWN SUNDAY MORNING. THE WIND WILL CONTINUE TO VEER AROUND THROUGH SUNDAY MORNING AND SHOULD BE NORTHERLY JUST PRIOR TO NOON ON SUNDAY. CAN NOT RULE OUT A FEW MORE FLURRIES SUNDAY MORNING...BUT NOT A BIG ENOUGH DEAL TO WARRANT MENTION IN THE TAF AT THIS POINT IN TIME. WE MAY BOUNCE AROUND A BIT BETWEEN MVFR AND VFR CEILINGS THROUGH THE PERIOD...AND WILL GENERALLY CALL FOR PREVAILING MVFR CONDITIONS THROUGH SUNDAY MORNING AND LOW END VFR BY SUNDAY AFTERNOON. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADP LONG TERM...HEINLEIN AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
332 PM MST FRI FEB 27 2015 .SYNOPSIS... AN UNSETTLED WEATHER PATTERN CONTINUES OVER NORTHERN AND CENTRAL NEW MEXICO AS A SERIES OF STORM SYSTEMS PUSH OVER THE REGION. AS ONE UPPER LEVEL DISTURBANCE DEPARTED THE STATE TO THE EAST THIS MORNING...ANOTHER ONE IS CURRENTLY ARRIVING FROM THE WEST. ADDITIONAL SNOW ACCUMULATIONS ARE EXPECTED THIS EVENING AND OVERNIGHT...PRIMARILY IN NORTHWESTERN TO CENTRAL AND NORTH CENTRAL PARTS OF NEW MEXICO. INTO SATURDAY AND SUNDAY...ANOTHER POTENT DISTURBANCE WILL DIVE INTO CALIFORNIA BEFORE SLOWLY SPREADING OVER NEW MEXICO. A PROLONGED PERIOD OF HIGH ELEVATION SNOW IS EXPECTED OVER NORTH CENTRAL TO NORTHWESTERN NEW MEXICO SATURDAY...SUNDAY...AND INTO MONDAY AND TUESDAY. THE HIGHEST SNOW TOTALS WILL BE FOUND IN THE SAN JUAN OR TUSAS MOUNTAINS NEAR THE COLORADO BORDER WHERE AN ADDITIONAL ONE TO TWO FEET OF SNOW COULD ACCUMULATE...PRIMARILY IN THE HIGHER ELEVATIONS ABOVE EIGHT THOUSAND FEET. RAIN WILL FALL IN LOWER ELEVATIONS DURING THIS WEEKEND TO EARLY NEXT WEEK PERIOD. && .DISCUSSION...IT`S ANOTHER BUSY AND CHALLENGING FORECAST DAY IN THE MIDDLE OF A BARRAGE OF UPPER LEVEL DISTURBANCES. NOT MUCH OF A RESPITE OR LULL IN THE PRECIPITATION WAS OBSERVED THIS MORNING BEFORE THE NEXT UPSTREAM SYSTEM STARTED SPREADING MORE BATCHES OF SNOW INTO WETSERN NM. THIS LATTER DISTURBANCE IS A BIT MORE SUBTLE LOOKING ON WATER VAPOR IMAGERY COMPARED TO ITS PREDECESSOR...HOWEVER JET DYNAMICS ARE UNDERWAY AND STRENGTHENING WITH LOTS OF DIVERGENCE ALOFT BEING DEPICTED BY FORECAST MODELS. THIS SEEMS TO BE QUICKLY COMING TO FRUITION GIVEN LIGHT SNOW THAT HAS ALREADY ENSUED AND STARTED AGAIN IN CENTRAL TO WESTERN ZONES. FORECAST MODELS KEEP THIS DIVERGENCE ALOFT PEGGED OVER THE NORTHWESTERN QUADRANT OF NM TONIGHT...AND QPF IS GENEROUSLY PAINTED BENEATH. HRRR MODEL IS ALSO QUITE GENEROUS WITH THIS TREND WITH A FEW MESOSCALE BANDS OF SNOW BEING DEPICTED. THUS...FELT PRUDENT TO SPATIALLY AND TEMPORALLY EXTEND ADVISORIES/WARNING WESTWARD AND LONGER RESPECTIVELY. THESE AMENDMENTS WERE MADE AT NOON AND WILL HOLD FOR NOW. INTO SATURDAY THE DIVERGENCE SLOWLY DECREASES IN INTENSITY OVER NM AND THE FLOW ALOFT BEGINS BACKING MORE SOUTHWESTERLY AS A LOW TAKES SHAPE AND DIVES INTO CA. THIS SHOULD BEGIN A REDUCTION IN THE COVERAGE OF PRECIPITATION IN SOME LOWER ELEVATION AREAS...REDUCTION BEING RELATIVE...WHILE OROGRAPHICS BECOME THE MORE DOMINANT FORCING MECHANISM FOR THE HIGHER TERRAIN. ELEVATIONS BELOW 7000 FEET WOULD ALSO OBSERVE A QUICK WARMING TREND AS WARM AIR ADVECTION BEGINS IN THE SOUTHWESTERLY FLOW. THE FORECAST MODELS MAY BE A BIT TOO HIGH WITH MAX TEMPERATURE GUIDANCE ON THIS THOUGH...AS THE CLOUD COVER MAY BE SLOW TO ERODE...STUNTING THE WARMING MORE THAN WHAT IS ADVERTISED BY MODELS. HAVE BUILT IN A QUICK CHANGEOVER TO RAIN IN THESE LOWER ELEVATIONS BY LATE MORNING AND INTO THE AFTERNOON...BUT THIS COULD BE A BIT PREMATURE AND WILL NEED TO BE CLOSELY MONITORED. PRECIPITATION COULD ALSO BEGIN TO TAKE ON A SHOWERY OR CONVECTIVE NATURE TO IT AS MODELS HAVE LIFTED INDICES OF 0 TO -1C PROGGED OVER SOME NORTH CENTRAL TO NORTHWESTERN ZONES SATURDAY AFTERNOON. THIS WOULD ONLY ADD TO SNOW RATES IN THE HIGHER TERRAIN. THE WINTER HIGHLIGHTS/STATEMENTS IN THE NORTHWESTERN ZONES DROP OFF SATURDAY MORNING...BUT MAY NEED TO BE EXTENDED FOR AFOREMENTIONED REASONINGS. THE PRECIPITATION REALLY FOCUSES TOWARD THE NORTHWESTERN THIRD OF THE FORECAST AREA INTO SATURDAY NIGHT AND SUNDAY WITH FLOW CONTINUING TO BACK SLIGHTLY MORE WHILE SPEEDS ALOFT INCREASE. THIS WILL KEEP STEADY OROGRAPHIC FORCING OVER THE NORTH CENTRAL TO NORTHWESTERN MOUNTAINS WITH SOME PRONOUNCED PRECIPITATION SHADOWS DOWNWIND OR NORTHEAST OF CHUSKAS AND OTHER TOPOGRAPHICAL BARRIERS. THE SOUTHWESTERLY FLOW ALOFT AND RISING PRESSURE HEIGHTS WILL ALSO KEEP THE WARMER AIR ADVECTING THIS WAY...AND SATURDAY NIGHT`S LOW TEMPERATURES WILL BE 10 TO 15 DEGREES WARMER THAN TONIGHT`S READINGS WHILE SUNDAY`S HIGHS RISE ANOTHER 5 TO 15 DEGREES ABOVE SATURDAY`S HIGHS. THIS WARMING TREND WILL SHIFT SNOWFALL ACCUMULATIONS UPWARD TO 7500 TO 8500 FEET SUNDAY AFTERNOON. WHILE THIS WILL LIMIT THE SPATIAL AREA OF SNOWFALL ACCUMULATIONS...THE PEAKS ABOVE THIS THRESHOLD WILL STILL SEE REMARKABLE SNOW AMOUNTS...LIKELY ONE TO THREE FEET ON MANY PEAKS ABOVE 8500 FEET AND CLOSER TO FOUR FEET NEAR THE CO/NM BORDER ABOVE 10000 FEET. RUNOFF AND SNOW MELT AT LOWER ELEVATIONS WILL ALSO NEED TO BE MONITORED CLOSELY ON SUNDAY...PERHAPS CREATING HYDROLOGY ISSUES. AND THE THREAT FOR ACCUMULATION STILL WON`T END THROUGH MONDAY AS THE UPPER LOW ROUNDS SOUTHERN CA AND DRIVES A PACIFIC FRONT CLOSER TO NM...EVENTUALLY CROSSING INTO OUR FORECAST AREA MONDAY NIGHT. THIS FRONTOGENETICAL FORCING IN ITSELF WILL ALSO INDUCE A HEALTHY SLUG OF PRECIPITATION...POSSIBLY ENHANCED BY A SUBTROPICAL MOISTURE TAP. THEN A KICKER SHORT WAVE TROUGH WILL DIG ON THE BACK SIDE OF THIS BEFORE TURNING INTO OLD MEXICO TUESDAY AND EARLY WEDNESDAY. FINALLY THE CABOOSE IN THE TRAIN OF STORM SPILLS SOUTHWARD IN STRONG MERIDIONAL FLOW ON WEDNESDAY...UNLOCKING THE DOOR TO SOME VERY COLD CONTINENTAL POLAR AIR. ONCE THIS SYSTEM PASSES...A WELCOME DRIER PATTERN SHOULD FOLLOW INTO THURSDAY OF NEXT WEEK. 52 && .FIRE WEATHER... AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH THE MIDDLE OF NEXT WEEK. MOIST WESTERLY FLOW WILL CONTINUE OVER NORTHERN AND CENTRAL NEW MEXICO TONIGHT AND SATURDAY...ALLOWING WEST FACING HIGHER TERRAIN LOCATIONS...ESPECIALLY FROM THE WEST CENTRAL TO THE NORTH CENTRAL...TO CONTINUE PICKING UP SNOW. THE WINDS ALOFT TRANSITION TO SOUTHWEST SUNDAY INTO MONDAY AS AN UPPER LOW/TROUGH DIG INTO SOCAL AND ARIZONA. TEMPERATURES WILL WARM IN ADVANCE OF THE LOW...ALLOWING SNOW LEVELS TO GRADUALLY RISE FROM WHAT THEY ARE THIS AFTERNOON. SOME COOLER AIR MAY ENTER THE EASTERN PLAINS SUNDAY...BOTH ECMWF AND GFS AGREE...BUT LOOKS LIKE IT MERELY RETARDS WARMING IN THE PLAINS FOR ANOTHER DAY RATHER THAN BRINGS ANOTHER SURGE OF MUCH COLDER AIR. A SPLIT FLOW PATTERN DOMINATES EARLY TO MID NEXT WEEK...PERMITTING A MUCH COLDER AND DRIER AIR MASS TO SURGE INTO THE EASTERN PLAINS TUESDAY NIGHT/WEDNESDAY. THIS LOOKS TO BE THE LAST GASP FOR THE ACTIVE WEATHER AT LEAST FOR THE REST OF NEXT WEEK. THROUGH EARLY NEXT WEEK...HEAVY SNOW ACCUMULATIONS ARE LIKELY FOR THE NORTHERN MOUNTAINS. ALTHOUGH SNOW LEVELS ARE FORECAST TO RISE SUNDAY INTO MONDAY...SOME OF THE HIGHER NORTHERN/WESTERN TERRAIN WILL CONTINUE TO RECEIVE SNOW...AND SNOW LEVELS OVERALL FALL AGAIN TUESDAY AS THE UPPER LOW/TROUGH MOVE OVERHEAD AND TO OUR SOUTH. HIGH TEMPERATURES THROUGH THE MIDDLE OF NEXT WEEK WILL REMAIN BELOW AVERAGE. VENT RATES WILL BE POOR IN THE EAST SATURDAY AND SUNDAY BUT GOOD TO EXCELLENT OVER MOST OF THE WEST CENTRAL AND SOUTHWEST DUE TO INCREASING WINDS AND MIXING HEIGHTS. VENT RATES OVERALL NEXT MONDAY AND TUESDAY WILL BE EXCELLENT THEN WORSEN SOMEWHAT WEDNESDAY. EXCELLENT RH RECOVERIES EXPECTED THROUGH THE PERIOD ALTHOUGH MIN RH VALUES TREND MUCH LOWER WEDNESDAY INTO THURSDAY. && .AVIATION... 18Z TAF CYCLE MTS OBSCURED IN WDSPRD MVFR TO IFR CIGS/VSBYS IN SNOW AND FOG ALTHOUGH A MIX OF RAIN AND SNOW POSSIBLE LOWER ELEVATIONS WEST OF THE CONTDVD BEFORE 28/00Z. SNOW TO INCREASE FROM THE CHUSKA MTS EAST AND NORTHEAST TO THE SANGRE DE CRISTO MTS AND POSSIBLY AS FAR SOUTH INTO THE ABQ METRO AFT 28/00Z. UPPER JET TO REMAIN ORIENTED FROM NW TO SE OVER NEW MEXICO THRU 28/12Z AS SURFACE HIGH PRESSURE OVER ERN NM BEGINS TO WEAKEN. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 30 46 33 46 / 80 70 60 60 DULCE........................... 22 37 28 42 / 90 80 80 90 CUBA............................ 24 38 30 45 / 90 70 60 80 GALLUP.......................... 32 47 36 50 / 60 70 70 80 EL MORRO........................ 29 47 35 51 / 50 50 60 70 GRANTS.......................... 27 50 32 54 / 60 40 40 60 QUEMADO......................... 31 50 38 53 / 30 20 40 40 GLENWOOD........................ 37 61 42 62 / 10 30 20 50 CHAMA........................... 19 34 26 40 / 90 80 80 90 LOS ALAMOS...................... 22 37 33 46 / 70 60 60 70 PECOS........................... 15 36 31 44 / 80 50 60 50 CERRO/QUESTA.................... 17 34 27 42 / 90 60 70 70 RED RIVER....................... 17 28 26 37 / 90 70 70 70 ANGEL FIRE...................... 14 33 23 40 / 90 60 70 60 TAOS............................ 20 36 31 45 / 80 60 60 60 MORA............................ 14 37 31 44 / 60 40 60 50 ESPANOLA........................ 22 43 32 52 / 60 40 40 50 SANTA FE........................ 20 39 33 48 / 70 50 50 50 SANTA FE AIRPORT................ 20 41 32 50 / 60 40 50 50 ALBUQUERQUE FOOTHILLS........... 26 48 36 57 / 60 40 40 30 ALBUQUERQUE HEIGHTS............. 27 50 37 60 / 50 30 30 30 ALBUQUERQUE VALLEY.............. 25 52 34 62 / 50 30 30 30 ALBUQUERQUE WEST MESA........... 25 50 36 61 / 60 30 40 40 LOS LUNAS....................... 28 53 36 62 / 30 20 20 20 RIO RANCHO...................... 27 48 36 58 / 60 30 40 40 SOCORRO......................... 31 56 39 64 / 20 10 10 10 SANDIA PARK/CEDAR CREST......... 20 40 34 49 / 60 40 50 40 TIJERAS......................... 24 45 35 55 / 60 40 50 30 MORIARTY/ESTANCIA............... 17 43 31 56 / 60 30 40 20 CLINES CORNERS.................. 15 37 30 48 / 60 30 40 20 GRAN QUIVIRA.................... 21 45 36 55 / 40 20 20 20 CARRIZOZO....................... 28 53 40 60 / 20 10 10 10 RUIDOSO......................... 26 49 36 57 / 30 20 10 10 CAPULIN......................... 10 31 24 33 / 50 30 30 40 RATON........................... 11 33 23 38 / 60 30 40 40 SPRINGER........................ 12 35 24 41 / 60 30 30 30 LAS VEGAS....................... 12 35 29 43 / 60 40 40 30 CLAYTON......................... 11 32 22 30 / 50 20 20 30 ROY............................. 13 31 26 39 / 50 30 30 20 CONCHAS......................... 18 36 29 46 / 40 20 20 20 SANTA ROSA...................... 18 36 30 52 / 40 20 20 10 TUCUMCARI....................... 17 38 30 46 / 30 20 10 10 CLOVIS.......................... 16 39 30 54 / 30 20 10 5 PORTALES........................ 17 41 31 58 / 30 20 10 0 FORT SUMNER..................... 19 40 31 54 / 30 20 10 5 ROSWELL......................... 23 49 34 65 / 30 10 10 0 PICACHO......................... 22 48 33 64 / 30 10 10 0 ELK............................. 23 52 37 63 / 20 10 10 5 && .ABQ WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 8 AM MST SATURDAY FOR THE FOLLOWING ZONES...NMZ502>504-516-518-519-521. WINTER WEATHER ADVISORY UNTIL 8 AM MST SATURDAY FOR THE FOLLOWING ZONES...NMZ501-505>507-517. WINTER STORM WARNING UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING ZONES...NMZ510>515-527. && $$ 52
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1104 PM MST THU FEB 26 2015 .AVIATION... 06Z TAF CYCLE WIDESPREAD IFR TO LIFR CONDITIONS TO CONTINUE FROM CENTRAL MT CHAIN EAST WITH MT OBSCURATIONS THROUGH MOST THIS 24 HR FCST PERIOD...BUT SOME SLIGHT IMPROVEMENT IS POSSIBLE IN THE AFTN. ALSO PATCHES OF -SN TO SN OVERNIGHT WILL BECOME LIGHTER AND MUCH MORE SPOTTY AFTER DAWN. LVS/TCC WILL BE IMPACTED MOST WITH ROW ALSO BEING IMPACTED TO SOME DEGREE. FARTHER WEST AREAS OF MVFR AND MORE LOCALIZED IFR CIGS CAN BE EXPECTED AT LEAST INTO ROUGHLY MID MORN FRI WITH IMPROVEMENT TO VFR YET SOME PATCHY MVFR WITH OCCASIONAL MT OBSCURATIONS. GAP WINDS INTO RIO GRANDE VALLEY ALSO TO CONTINUE THROUGH EARLY MORN FRI THEN DIMINISH TO SOME DEGREE. AWW TO BE CONTINUED AT ABQ FOR NOW MORE DUE TO SN THAN WIND AS UP TO AN INCH OR TWO OF SN TO ACCUMULATE THERE THROUGH 08Z...THOUGH SOME WIND GUSTS STILL MAY APPROACH 30 TO 35 KT RANGE BETWEEN 07Z AND 10Z. IFR/MVFR CIGS AND OCCASIONALLY VSBY DUE TO SN IS EXPECTED AT ABQ/SAF/AEG MAINLY THROUGH 08 TO 09Z WITH SOME IMPROVEMENT THEREAFTER...ESPEC AT ABQ. AEG AND SAF MAY EVEN SEE A FEW PERIODS OF LIFR CONDITIONS DURING HEAVIER SNOW BURSTS AND THEREAFTER INTO EARLY TO MID MORN DUE LARGELY TO FOG. 43 && .PREV DISCUSSION...731 PM MST THU FEB 26 2015... .UPDATE... NAM12 AND HRRR SHOW LARGER SNOW AMOUNTS OVER SOCCORO AND LINCOLN COUNTY THAN EARLIER ANTICIPATED...AS UPPER JET SAGS FARTHER SOUTH TONIGHT. LIGHT SNOW AT KONM PRESENTLY...SO DECIDED TO GO AHEAD WTIH SOME EXPANDED WINTER WEATHER AVISORIES. UPDATED ZFP AND WSW ALREADY OUT. 43 && .PREV DISCUSSION...333 PM MST THU FEB 26 2015... .SYNOPSIS... AN UNSETTLED WEATHER PATTERN WILL CONTINUE OVER NORTHERN AND CENTRAL NEW MEXICO THROUGH THE NEXT SEVERAL DAYS AS NUMEROUS DISTURBANCES ALOFT BRING PRECIPITATION TO THE STATE. TEMPERATURES ARE CURRENTLY WELL BELOW AVERAGE...ESPECIALLY IN THE EASTERN PLAINS OF THE STATE WHERE READINGS ARE SOME 30 DEGREES BELOW NORMAL FOR LATE FEBRUARY. WITH COLDER AIR IN PLACE...SNOW IS EXPECTED TO BREAK OUT OVER MUCH OF CENTRAL TO EASTERN NEW MEXICO TONIGHT INTO FRIDAY AS AN UPPER LEVEL DISTURBANCE APPROACHES. SEVERAL INCHES OF ADDITIONAL ACCUMULATION ARE EXPECTED BY TOMORROW...ESPECIALLY IN THE MOUNTAINS AND HIGHLANDS OF NORTHERN AND CENTRAL NEW MEXICO. AS THE WEEKEND UNFOLDS...ANOTHER POTENT DISTURBANCE WILL DIVE INTO CALIFORNIA BEFORE SLOWLY SPREADING OVER NEW MEXICO. A PROLONGED PERIOD OF HIGH ELEVATION SNOW IS EXPECTED SATURDAY...SUNDAY...AND INTO MONDAY AND TUESDAY. THE HIGHEST SNOW TOTALS WILL BE FOUND IN THE SAN JUAN OR TUSAS MOUNTAINS NEAR THE COLORADO BORDER WHERE TWO TO FOUR FEET OF SNOW COULD ACCUMULATE ABOVE TEN THOUSAND FEET. RAIN WILL FALL IN LOWER ELEVATIONS DURING THIS WEEKEND TO EARLY NEXT WEEK PERIOD. && .DISCUSSION... IT HAS BEEN AN EXTREMELY BUSY SHIFT TODAY WITH A FOCUS ON WINTER HIGHLIGHTS IN NOT ONLY THE NEAR TERM...BUT ALSO FOR THE NEXT IMPENDING UPPER LOW THAT WILL BEGIN IMPACTING NM THIS WEEKEND. SOMEWHAT OF A LULL OR RESPITE HAS BEEN OBSERVED THIS AFTERNOON WITH REGARDS TO SNOW...BUT IT HAS NOT FULLY ENDED IN SOME OF THE NORTHERN MOUNTAIN LOCALES. THE NEXT UPSTREAM DISTURBANCE IS LOOKING HEALTHY ON WATER VAPOR SATELLITE IMAGERY...CURRENTLY JUST WEST OF THE FOUR CORNERS AREA...PERHAPS A BIT FARTHER SOUTH THAN MODELS HAVE BEEN INDICATING. THIS WILL SPREAD SUFFICIENT DYNAMICS ALOFT TO SATURATE THE MID LEVELS OF THE ATMOSPHERE WHICH WILL THEN SEED LOWER LEVELS AND PRODUCE SIGNIFICANT SNOW...ESPECIALLY WHERE EAST/SOUTHEAST UPSLOPE FLOW WILL BE RUNNING UP ON THE RESPECTIVE SLOPES OF HIGHER TERRAIN. SANGRES AND CENTRAL MOUNTAINS/HIGHLANDS APPEAR TO BENEFIT THE MOST FROM THE UPSLOPE WHILE SATURATED MID LEVEL CLOUD DECKS WILL SEED LOWER LAYERS...INDUCING SNOW GROWTH. IN ADDITION THE DYNAMICS SHOULD BE ENOUGH TO PRODUCE SIGNIFICANT SNOWFALL OVER THE HIGHER PEAKS OF THE REMAINING NORTHERN MOUNTAINS. THE EASTERLY FLOW HAS BEEN ACCELERATING THROUGH GAPS/CANYONS WITHIN THE CENTRAL MOUNTAIN CHAIN...AND AN EARLY EVENING SURGE SHOULD ALLOW SPEEDS TO JUMP UP SEVERAL MPH AT KABQ AND KSAF. THIS SHOULD SHADOW MUCH OF THE ALBUQUERQUE METRO AREA WITH REGARD TO SNOW...SO HIGHLIGHTS WERE HEDGED ON LOWER SIDE WITH JUST AN ADVISORY. AS THIS EVENING`S DISTURBANCE TRACKS INTO TX ON FRIDAY...SNOW WILL BEGIN TO TAPER OFF TOWARD MID DAY. SOME UPSLOPE WILL CONTINUE THOUGH...KEEPING THOSE FAVORED AREAS PRECIPITATING AT LIGHT RATES. SOME OF THE HIGHLIGHTS WILL NEED TO BE CONTINUOUSLY MONITORED TO DECIDE ON EARLIER EXPIRATION FRIDAY. TEMPERATURES WILL BE EVEN COLDER IN MOST ZONES ON FRIDAY AS THE SYNOPTIC COLD POOL CONTINUES SEEPING WESTWARD. THIS WILL PUT MOST ZONES AT 10 TO 40 DEGREES BELOW NORMAL FRIDAY AFTERNOON. INTERESTINGLY MODELS BREAK OUT NEW BATCHES OF PRECIPITATION IN THE NORTHWESTERN QUADRANT OF THE STATE FRIDAY AFTERNOON. WITHOUT THE PRESENCE OF ANY BLATANT PERTURBATION IMMEDIATELY UPSTREAM...IT APPEARS THE TRIGGER IS SOME DIVERGENCE ALOFT...ASSOCIATED WITH JET DYNAMICS FAR AHEAD OF THE NEXT TROUGH DIVING INTO THE GREAT BASIN. HAVE INCREASED POPS SOME TO REFLECT HIGHER PROBABILITIES IN THE NORTHWESTERN ZONES...BUT MAY NOT HAVE RAISED ENOUGH. CONFIDENCE IS HIGHER IN THE ELEVATED PROBABILITIES OVER NORTHWESTERN TO WEST CENTRAL NM FRIDAY NIGHT AND SATURDAY AS THE AFOREMENTIONED TROUGH DIVES SOUTHWARD OVER CALIFORNIA AND DEEPENS INTO A LOW...SHEDDING ENERGY INTO AZ/NM. THIS WILL BRING A STIFFENING SOUTHWESTERLY FLOW OVER NM THAT WOULD HAVE GOOD OROGRAPHICS ASSOCIATED WITH IT WHILE ALSO ACTING AS A WARM ADVECTION CATALYST. HAVE OPTED TO ISSUE WINTER STORM WATCH FOR THE SAN JUAN/TUSAS AND JEMEZ ZONES STARTING FRIDAY NIGHT AND RUNNING INTO SUNDAY. QPF AMOUNTS ARE VERY IMPRESSIVE WITH THIS FEATURE FRIDAY NIGHT THROUGH SUNDAY. CHALLENGES WILL ARISE FROM THE WARM ADVECTION...INDUCING RISING SNOW LEVELS AND COMPLICATING THE SNOW RATIOS. AT THIS POINT IT STILL APPEARS 2 TO 4 FEET OF NEW SNOW WOULD BE REASONABLE IN THIS SCENARIO NEAR THE CO-NM BORDER ABOVE 10KFT. SNOW LEVELS WOULD LIKELY RISE TO NEAR 8000 TO 8500 FEET SUNDAY...AND WHILE THIS MIGHT SUGGEST A LIMITING OF ACCUMULATIONS AND IMPACTS...THE HYDROLOGY IMPACTS WILL HAVE TO BE STRONGLY CONSIDERED. IF HEALTHY RAINFALL OCCURS OVER SOME OF THE SNOW PACK...IN THE 7000 TO 9000 FT RANGE...SOME SUBSTANTIAL MELT AND RUNOFF COULD OCCUR. WILL MONITOR THIS SCENARIO CLOSELY THE NEXT COUPLE OF DAYS. AS THE CA LOW FINALLY DRAGS NORTHEASTWARD OVER NM MONDAY AND MONDAY NIGHT...ANOTHER PERTURBATION WILL DROP DOWN ON ITS HEELS TUESDAY...FOLLOWED BY ANOTHER ON WEDNESDAY. THE WEDNESDAY FEATURE COULD ALLOW A VERY COLD DOME TO SPILL SOUTHWARD INTO NM...BUT IT WOULD APPEAR TO BE THE CABOOSE ON THE RECENT STORM TRAIN. 52 && .FIRE WEATHER... NO FIRE WEATHER CONCERNS NEXT SEVERAL DAYS. THE ACTIVE WINTER WEATHER PATTERN WILL CONTINUE THROUGH MIDDLE OF NEXT AS A SERIES OF UPPER LEVEL DISTURBANCES CROSS OVER THE STATE. TEMPS AREAWIDE WILL REMAIN BELOW NORMAL THROUGH WEDNESDAY WITH UNUSUALLY HIGH HUMIDITY. GUSTY GAP WINDS WILL CONTINUE ALONG THE CENTRAL MOUNTAINS FOR THE NEXT 24-48 HOURS. OTHERWISE...ANOTHER ROUND OF WETTING SNOW WILL DEVELOP AND FAVOR CENTRAL/EASTERN AREAS TONIGHT INTO FRIDAY MORNING. SNOW SHOWERS SHOULD CONTINUE ACROSS WESTERN/CENTRAL AREAS FRIDAY AFTERNOON. WETTING PRECIPITATION WILL THEN BE CONFINED TO OVER NORTHERN AND WESTERN AREAS THIS WEEKEND. SNOW LEVELS WILL RISE DURING THIS PERIOD AS THE ATMOSPHERE WARMS. MODELS HAVE BEEN TRENDING TOWARDS MORE OF AN UPPER LEVEL DRY SLOT IMPACT SOUTH CENTRAL/SOUTHEAST AREAS DURING THIS SAME PERIOD. TEMPERATURES WILL MODIFY SOME BUT WILL REMAIN BELOW NORMAL. BREEZY CONDITIONS ARE EXPECTED ACROSS WESTERN/CENTRAL AREAS ESPECIALLY FAVORING THE HIGH TERRAIN. WINDY CONDITIONS ARE VERY POSSIBLE ACROSS THE HIGH TERRAIN AS THE FLOW ALOFT INCREASES. MORE UPPER LEVEL DISTURBANCES FROM THE WEST WILL FOLLOW MONDAY THRU WEDNESDAY BRINGING MORE RAIN/SNOW SHOWERS TO WESTERN AND CENTRAL AREAS. EASTERN AREAS SHOULD GET INTO THE ACTION BY MIDWEEK. TEMPS WILL BE A BIT WARMER IN THE EAST...COOLER IN THE WEST ON MONDAY AND TUESDAY..THEN COOLING ALL OVER WEDNESDAY. VENTILATION IS EXPECTED TO LOWER ON FRIDAY DUE TO LOWER MIXING HEIGHTS AND IMPACTS FROM THE BACK DOOR COLD PUSH. VENTILATION WILL IMPROVE AS THE WEEKEND PROGRESSES...ESPECIALLY ON SUNDAY. GOOD TO EXCELLENT VENT RATES ARE EXPECTED EARLY NEXT WEEK AS THE ATMOSPHERE REMAINS UNSETTLED AND HIGHER TRANSPORT WINDS EXIST. 50 && .ABQ WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON MST FRIDAY FOR THE FOLLOWING ZONES...NMZ504-507-508-520-524>526-530-533>540. WINTER STORM WARNING UNTIL NOON MST FRIDAY FOR THE FOLLOWING ZONES...NMZ512>516-527>529-531-532. WINTER WEATHER ADVISORY UNTIL 5 PM MST FRIDAY FOR THE FOLLOWING ZONES...NMZ517-519. WINTER STORM WARNING UNTIL 5 PM MST FRIDAY FOR THE FOLLOWING ZONES...NMZ510-511-518-521>523. WINTER STORM WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY AFTERNOON FOR THE FOLLOWING ZONES...NMZ510-511. && $$
AREA FORECAST DISCUSSION
NWS TULSA OK
846 PM CST SAT FEB 28 2015 .DISCUSSION... IT NOW LOOKS LIKE THE SNOW IS CONFINED TO EXTREME NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS AT THIS HOUR. FREEZING RAIN IS BECOMING MORE OF AN ISSUE WITH AREAS OF FREEZING RAIN AND SLEET ACROSS SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. A SOUTHWESTERLY LOW LEVEL JET OF AROUND 60 MPH CONTINUES TO CREATE ISENTROPIC LIFT ACROSS THE REGION THIS EVENING PRODUCING THE AREAS OF FREEZING RAIN AND SLEET. THIS IS EXPECTED TO PERSIST FOR A GOOD DEAL OF THE NIGHT. HAVE INCREASED ICE AMOUNTS SOME ACROSS EAST-CENTRAL OKLAHOMA INTO WESTERN ARKANSAS. STILL BELOW WARNING CRITERIA. THE HRRR SHOWS THE PRECIP TAPERING OFF AROUND 3 AM. WILL SEE MAINLY FREEZING DRIZZLE ACROSS THE REMAINDER OF NORTHEAST OKLAHOMA. THE TEMPERATURE HAS RISEN TO FREEZING OR JUST ABOVE ACROSS FAR SOUTHEAST OKLAHOMA. WILL CONTINUE ADVISORY AS IS FOR NOW. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR OKZ049-OKZ053- OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061- OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069- OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076. AR...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR ARZ001-ARZ002- ARZ010-ARZ011-ARZ019-ARZ020-ARZ029. && $$ SHORT TERM...10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
758 AM EST FRI FEB 27 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA THROUGH THE FIRST HALF OF THE WEEKEND. A LOW PRES SYSTEM WILL LIFT OUT OF THE MIDWEST LATE IN THE WEEKEND...PASSING OVER THE REGION SUNDAY NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY OR EARLY WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AT 11Z RADAR CONTINUES TO SHOW PATCHY LIGHT SNOW FALLING FROM ARND KUNV SEWRD INTO THE LOWER SUSQ VALLEY ALONG AXIS OF INVERTED SFC TROF. RETURNS SHOULD CONTINUE TO DIMINISH...AS DRIER AIR WORKS IN. BLEND OF LATEST HRRR AND 4KM NAM INDICATE ANY ACCUMS AFTER 12Z WILL BE NEGLIGIBLE. SATL IMAGERY SHOWS CLEARING SKIES ACROSS NORTHWEST PA EARLY THIS AM...AS DRY...ARCTIC AIR MASS OVERSPREADS THE AREA. EXPECT THIS PARTIAL CLEARING TO PROGRESS INTO THE EASTERN HALF OF THE STATE LATER THIS MORNING. UPSTREAM OBS SUGGEST SKIES MAY BECOME MOSUNNY FOR A WHILE THIS MORNING. HOWEVER...DIURNAL HEATING...COMBINED WITH COLD POOL ALOFT...SHOULD YIELD A FAIR AMT OF STRATO CU THIS AFTN...ESP OVR THE ALLEGHENY PLATEAU. GEFS MEAN 925MB TEMPS ARND -15C SHOULD TRANSLATE TO HIGHS NO BETTER THAN ARND 10F ACROSS THE HIGHER TERRAIN OF THE ALLEGHENIES...TO THE L/M20S ACROSS THE SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... CLEARING SKIES...A CALM WIND AND SNOW COVER WILL LIKELY RESULT IN THE LOWEST TEMPS UNTIL NEXT WINTER TONIGHT AS THE CENTER OF HIGH PRESSURE MOVES OVER PENN. THE IDEAL RADIATIONAL COOLING CONDS SHOULD ALLOW READINGS TO BOTTOM OUT FROM 10-15F BELOW ZERO ACROSS THE WESTERN MTNS...TO 0-5F ABV ZERO ACROSS THE LOWER SUSQ VALLEY. THE COLDEST RURAL VALLEYS IN NW AND NCENT PENN COULD SEE THE MERCURY SETTLE TO AROUND -20F AT 11-12Z SATURDAY. SOME LOCATIONS ACROSS THE NW MTNS ARE LIKELY REACH WCHILL ADVISORY CRITERIA...DESPITE A LIGHT/CALM WIND. HOWEVER...CONFIDENCE IN WIDESPREAD APPARENT TEMPS BLW -15F NOT THERE YET FOR AN ADVISORY. FAIR AND STILL COLD WEATHER EXPECTED SATURDAY...AS SFC HIGH DRIFTS OVR THE AREA. A FAST-MOVING MID LVL SHORTWAVE IS PROGGED BY ALL MDLS TO TRACK ACROSS THE AREA LATE IN THE DAY. LOW PWAT AIR MASS WILL PRECLUDE ANY PRECIP CONCERNS. HOWEVER...CIRRUS MAY DIM THE SUNSHINE AT TIMES. ENS MEAN 850/925MB TEMPS REMAIN WELL BLW NORMAL FOR THE DATE...LIKELY SUPPORTING HIGHS ONLY IN THE 20-25F RANGE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A RELATIVELY MILD/ACTIVE SOUTHWEST FLOW ALOFT SHOULD PREVAIL THROUGH THE PERIOD AS THE PERSISTENT UPPER RIDGE OVER THE WRN U.S. TEMPORARILY BREAKS DOWN. AN ARCTIC HIGH PRESSURE SYSTEM OVER CENTRAL PA AT THE START OF THE PERIOD WILL RETREAT INTO ATLANTIC CANADA BY SUNDAY NIGHT. THE COMBINATION OF SHORTWAVE ENERGY IN THE SRN STREAM EJECTING FROM A DSW TROUGH AND A DIGGING NRN STREAM TROUGH MOVING SEWD FROM SOUTH CENTRAL CANADA TOWARD THE UPPER MIDWEST SEEMS TO DRIVE AN EXPANDING AREA OF WAA TYPE SNOWFALL SPREADING EASTWARD SUN-MON BEHIND THE SOUTHERLY RETURN FLOW INTO A RETREATING COLD SECTOR ASSOCD WITH THE DEPARTING ARCTIC HIGH. THE PCPN SHOULD BE ENHANCED ALONG AN EXPANDING BAROCLINIC ZONE ACROSS THE CENTRAL AND EASTERN US...AS UPPER RIDGING BUILDS OVER THE SE U.S. WHILE THERE APPEARS TO BE LITTLE INDICATION OF A STRONG SURFACE LOW...MODELS STILL GENERATE 0.25-0.50 INCH QPF AMTS ALONG THE BAROCLINIC ZONE. THERMAL PROFILES SEEM TO FAVOR SNOW ACROSS THE NW 1/2 OF CENTRAL PA WITH MIXED PTYPES IN THE SOUTH/SOUTHEAST. PRELIMINARY 24HR SNOW/ICE AMOUNTS WERE DERIVED USING A MULTI MODEL QPF BLEND WITH PSEUDO INTERNAL BIAS CORRECTION FACTOR AND WPC WWD. THIS RESULTS IN ADVY LEVEL SNOWFALL OVER THE NW 1/2 AND 0.10 INCH ICE/ZR OVER THE LWR SUSQ VLY. CONFIDENCE IN THE AMTS IS AVG AT BEST GIVEN UNCERTAINTY IN QPF AND LOW-LEVEL TEMPERATURES. THE LACK OF A DEFINED SFC CYCLONE ALSO RAISES SOME REG FLAGS. ANOTHER COLD HP SYSTEM BUILDS INTO THE REGION MON-TUE WITH ANOTHER SW FLOW WAA MSTR SURGE ALONG BAROCLINIC FRONTAL ZONE LKLY IMPACTING THE AREA INTO THE MIDDLE OF NEXT WEEK. TIMING DIFFERENCES ARE EVIDENT WITH THE GFS MORE BULLISH ON PCPN RETURNING EARLY TUE VS. SLOWER ECMWF (TUE NGT). MIXED PTYPE ISSUES ARE EXPECTED AGAIN WITH THIS NEXT SYSTEM. && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... PATCHY LIGHT SNOW CONTINUES TO QUICKLY ERODE FROM KUNV SEWRD INTO THE LOWER SUSQ VALLEY ALONG AXIS OF INVERTED SFC TROF...AS DRIER ARCTIC AIR WORKS IN FROM THE WEST. CLEARING SKIES ACROSS NORTHWEST PA EARLY THIS AM SHOULD FILL BACK IN WITH COLD POOL STRATOCU MVFR CIGS FOR SEVERAL HOURS THIS MORNING THROUGH EARLY AFTERNOON...WITH OROGRAPHIC FLOW ALSO KEEPING LIGHT SNOW AND LOW CIGS/VSBYS IN KJST THROUGH AT LEAST EARLY AFTERNOON. REMAINDER OF THE AREA WILL BE OR TRANSITION TO VFR CONDITIONS OVER NEXT FEW HOURS AS ANOMALOUSLY STRONG 1040-1045 MB SFC HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY. WINDS WILL BE W/NW AT AROUND 10 MPH. OUTLOOK... FRI NIGHT AND SAT...NO SIG WX EXPECTED. SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE. MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM. TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE. && .CLIMATE... THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY MEAN TEMPERATURES THROUGH THE 26TH...IPT 18.2...MDT 20.7. THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET IN 1934. SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH COLDEST EVER AT MDT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD/STEINBUGL AVIATION...RXR CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
643 AM EST FRI FEB 27 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA THROUGH THE FIRST HALF OF THE WEEKEND. A LOW PRES SYSTEM WILL LIFT OUT OF THE MIDWEST LATE IN THE WEEKEND...PASSING OVER THE REGION SUNDAY NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY OR EARLY WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AT 11Z RADAR CONTINUES TO SHOW PATCHY LIGHT SNOW FALLING FROM ARND KUNV SEWRD INTO THE LOWER SUSQ VALLEY ALONG AXIS OF INVERTED SFC TROF. RETURNS SHOULD CONTINUE TO DIMINISH...AS DRIER AIR WORKS IN. BLEND OF LATEST HRRR AND 4KM NAM INDICATE ANY ACCUMS AFTER 12Z WILL BE NEGLIGIBLE. SATL IMAGERY SHOWS CLEARING SKIES ACROSS NORTHWEST PA EARLY THIS AM...AS DRY...ARCTIC AIR MASS OVERSPREADS THE AREA. EXPECT THIS PARTIAL CLEARING TO PROGRESS INTO THE EASTERN HALF OF THE STATE LATER THIS MORNING. UPSTREAM OBS SUGGEST SKIES MAY BECOME MOSUNNY FOR A WHILE THIS MORNING. HOWEVER...DIURNAL HEATING...COMBINED WITH COLD POOL ALOFT...SHOULD YIELD A FAIR AMT OF STRATO CU THIS AFTN...ESP OVR THE ALLEGHENY PLATEAU. GEFS MEAN 925MB TEMPS ARND -15C SHOULD TRANSLATE TO HIGHS NO BETTER THAN ARND 10F ACROSS THE HIGHER TERRAIN OF THE ALLEGHENIES...TO THE L/M20S ACROSS THE SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... CLEARING SKIES...A CALM WIND AND SNOW COVER WILL LIKELY RESULT IN THE LOWEST TEMPS UNTIL NEXT WINTER TONIGHT AS THE CENTER OF HIGH PRESSURE MOVES OVER PENN. THE IDEAL RADIATIONAL COOLING CONDS SHOULD ALLOW READINGS TO BOTTOM OUT FROM 10-15F BELOW ZERO ACROSS THE WESTERN MTNS...TO 0-5F ABV ZERO ACROSS THE LOWER SUSQ VALLEY. THE COLDEST RURAL VALLEYS IN NW AND NCENT PENN COULD SEE THE MERCURY SETTLE TO AROUND -20F AT 11-12Z SATURDAY. SOME LOCATIONS ACROSS THE NW MTNS ARE LIKELY REACH WCHILL ADVISORY CRITERIA...DESPITE A LIGHT/CALM WIND. HOWEVER...CONFIDENCE IN WIDESPREAD APPARENT TEMPS BLW -15F NOT THERE YET FOR AN ADVISORY. FAIR AND STILL COLD WEATHER EXPECTED SATURDAY...AS SFC HIGH DRIFTS OVR THE AREA. A FAST-MOVING MID LVL SHORTWAVE IS PROGGED BY ALL MDLS TO TRACK ACROSS THE AREA LATE IN THE DAY. LOW PWAT AIR MASS WILL PRECLUDE ANY PRECIP CONCERNS. HOWEVER...CIRRUS MAY DIM THE SUNSHINE AT TIMES. ENS MEAN 850/925MB TEMPS REMAIN WELL BLW NORMAL FOR THE DATE...LIKELY SUPPORTING HIGHS ONLY IN THE 20-25F RANGE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A RELATIVELY MILD/ACTIVE SOUTHWEST FLOW ALOFT SHOULD PREVAIL THROUGH THE PERIOD AS THE PERSISTENT UPPER RIDGE OVER THE WRN U.S. TEMPORARILY BREAKS DOWN. AN ARCTIC HIGH PRESSURE SYSTEM OVER CENTRAL PA AT THE START OF THE PERIOD WILL RETREAT INTO ATLANTIC CANADA BY SUNDAY NIGHT. THE COMBINATION OF SHORTWAVE ENERGY IN THE SRN STREAM EJECTING FROM A DSW TROUGH AND A DIGGING NRN STREAM TROUGH MOVING SEWD FROM SOUTH CENTRAL CANADA TOWARD THE UPPER MIDWEST SEEMS TO DRIVE AN EXPANDING AREA OF WAA TYPE SNOWFALL SPREADING EASTWARD SUN-MON BEHIND THE SOUTHERLY RETURN FLOW INTO A RETREATING COLD SECTOR ASSOCD WITH THE DEPARTING ARCTIC HIGH. THE PCPN SHOULD BE ENHANCED ALONG AN EXPANDING BAROCLINIC ZONE ACROSS THE CENTRAL AND EASTERN US...AS UPPER RIDGING BUILDS OVER THE SE U.S. WHILE THERE APPEARS TO BE LITTLE INDICATION OF A STRONG SURFACE LOW...MODELS STILL GENERATE 0.25-0.50 INCH QPF AMTS ALONG THE BAROCLINIC ZONE. THERMAL PROFILES SEEM TO FAVOR SNOW ACROSS THE NW 1/2 OF CENTRAL PA WITH MIXED PTYPES IN THE SOUTH/SOUTHEAST. PRELIMINARY 24HR SNOW/ICE AMOUNTS WERE DERIVED USING A MULTI MODEL QPF BLEND WITH PSEUDO INTERNAL BIAS CORRECTION FACTOR AND WPC WWD. THIS RESULTS IN ADVY LEVEL SNOWFALL OVER THE NW 1/2 AND 0.10 INCH ICE/ZR OVER THE LWR SUSQ VLY. CONFIDENCE IN THE AMTS IS AVG AT BEST GIVEN UNCERTAINTY IN QPF AND LOW-LEVEL TEMPERATURES. THE LACK OF A DEFINED SFC CYCLONE ALSO RAISES SOME REG FLAGS. ANOTHER COLD HP SYSTEM BUILDS INTO THE REGION MON-TUE WITH ANOTHER SW FLOW WAA MSTR SURGE ALONG BAROCLINIC FRONTAL ZONE LKLY IMPACTING THE AREA INTO THE MIDDLE OF NEXT WEEK. TIMING DIFFERENCES ARE EVIDENT WITH THE GFS MORE BULLISH ON PCPN RETURNING EARLY TUE VS. SLOWER ECMWF (TUE NGT). MIXED PTYPE ISSUES ARE EXPECTED AGAIN WITH THIS NEXT SYSTEM. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... LARGE-SCALE FORCING AHEAD OF A SHORTWAVE OVER THE GREAT LAKES BRINGING SOME LIGHT SNOW TO PORTIONS OF CENTRAL MTNS EARLY THIS MORNING. THIS WILL REDUCE VSBYS/CIGS TO MVFR /OCCASIONAL IFR/ PRIMARILY OVER THE WESTERN HIGHER TERRAIN THROUGH 12Z. BRIEF PERIOD OF MVFR CIGS POSS FURTHER EAST THROUGH 10Z. ANOTHER PUSH OF ARCTIC AIR ARRIVES IMMEDIATELY BEHIND THE SHORTWAVE FOR FRI. OROGRAPHIC FLOW WILL KEEP MVFR CONDITIONS IN WESTERN HIGHER TERRAIN THROUGH MIDDAY...WITH IMPROVING CONDITIONS IN THE AFTERNOON AS ANOMALOUSLY STRONG 1040-1045 MB SFC HIGH PRESSURE BUILDS INTO THE COMMONWEALTH FROM THE OHIO VALLEY. VFR WILL BE THE RULE IN CENTRAL AND EAST. WINDS WILL BE W/NW AT AROUND 10 MPH. OUTLOOK... FRI NIGHT AND SAT...NO SIG WX EXPECTED. SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE. MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM. TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE. && .CLIMATE... THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY MEAN TEMPERATURES THROUGH THE 26TH...IPT 18.2...MDT 20.7. THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET IN 1934. SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH COLDEST EVER AT MDT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD/STEINBUGL AVIATION...RXR CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
517 AM EST FRI FEB 27 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA THROUGH THE FIRST HALF OF THE WEEKEND. A LOW PRES SYSTEM WILL LIFT OUT OF THE MIDWEST LATE IN THE WEEKEND...PASSING OVER THE REGION SUNDAY NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY OR EARLY WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... RADAR CONTINUES TO SHOW PATCHY LIGHT SNOW FALLING ACROSS THE CENTRAL AND SC MTNS OF PA AT 09Z IN REGION OF LG SCALE FORCING AHEAD OF SHORTWAVE OVR THE GRT LKS. NEAR TERM MDL DATA SUGGESTS THE FOCUS OF THE LGT SNOW WILL REMAIN ALONG WEAK INVERTED SFC TROF EXTENDING FROM KUNV SE TO KTHV. BLEND OF LATEST HRRR AND 4KM NAM SUPPORT A FRESH DUSTING ACROSS THIS AREA BTWN 09Z-13Z. SATL IMAGERY SHOWS CLEARING SKIES ACROSS WESTERN PA EARLY THIS AM...AS DRY...ARCTIC AIR MASS OVERSPREADS THE AREA. EXPECT THIS PARTIAL CLEARING PROGRESS INTO THE EASTERN HALF OF THE STATE LATER THIS MORNING. UPSTREAM OBS SUGGEST SKIES MAY BECOME MOSUNNY FOR A WHILE THIS MORNING. HOWEVER...DIURNAL HEATING...COMBINED WITH COLD POOL ALOFT...SHOULD YIELD A FAIR AMT OF STRATO CU THIS AFTN...ESP OVR THE ALLEGHENY PLATEAU. GEFS MEAN 925MB TEMPS ARND -15C SHOULD TRANSLATE TO HIGHS NO BETTER THAN ARND 10F ACROSS THE HIGHER TERRAIN OF THE ALLEGHENIES...TO THE L/M20S ACROSS THE SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... CLEARING SKIES...A CALM WIND AND SNOW COVER WILL LIKELY RESULT IN THE LOWEST TEMPS UNTIL NEXT WINTER TONIGHT AS THE CENTER OF HIGH PRESSURE MOVES OVER PENN. THE IDEAL RADIATIONAL COOLING CONDS SHOULD ALLOW READINGS TO BOTTOM OUT FROM 10-15F BELOW ZERO ACROSS THE WESTERN MTNS...TO 0-5F ABV ZERO ACROSS THE LOWER SUSQ VALLEY. THE COLDEST RURAL VALLEYS IN NW AND NCENT PENN COULD SEE THE MERCURY SETTLE TO AROUND -20F AT 11-12Z SATURDAY. SOME LOCATIONS ACROSS THE NW MTNS ARE LIKELY REACH WCHILL ADVISORY CRITERIA...DESPITE A LIGHT/CALM WIND. HOWEVER...CONFIDENCE IN WIDESPREAD APPARENT TEMPS BLW -15F NOT THERE YET FOR AN ADVISORY. FAIR AND STILL COLD WEATHER EXPECTED SATURDAY...AS SFC HIGH DRIFTS OVR THE AREA. A FAST-MOVING MID LVL SHORTWAVE IS PROGGED BY ALL MDLS TO TRACK ACROSS THE AREA LATE IN THE DAY. LOW PWAT AIR MASS WILL PRECLUDE ANY PRECIP CONCERNS. HOWEVER...CIRRUS MAY DIM THE SUNSHINE AT TIMES. ENS MEAN 850/925MB TEMPS REMAIN WELL BLW NORMAL FOR THE DATE...LIKELY SUPPORTING HIGHS ONLY IN THE 20-25F RANGE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A RELATIVELY MILD/ACTIVE SOUTHWEST FLOW ALOFT SHOULD PREVAIL THROUGH THE PERIOD AS THE PERSISTENT UPPER RIDGE OVER THE WRN U.S. TEMPORARILY BREAKS DOWN. AN ARCTIC HIGH PRESSURE SYSTEM OVER CENTRAL PA AT THE START OF THE PERIOD WILL RETREAT INTO ATLANTIC CANADA BY SUNDAY NIGHT. THE COMBINATION OF SHORTWAVE ENERGY IN THE SRN STREAM EJECTING FROM A DSW TROUGH AND A DIGGING NRN STREAM TROUGH MOVING SEWD FROM SOUTH CENTRAL CANADA TOWARD THE UPPER MIDWEST SEEMS TO DRIVE AN EXPANDING AREA OF WAA TYPE SNOWFALL SPREADING EASTWARD SUN-MON BEHIND THE SOUTHERLY RETURN FLOW INTO A RETREATING COLD SECTOR ASSOCD WITH THE DEPARTING ARCTIC HIGH. THE PCPN SHOULD BE ENHANCED ALONG AN EXPANDING BAROCLINIC ZONE ACROSS THE CENTRAL AND EASTERN US...AS UPPER RIDGING BUILDS OVER THE SE U.S. WHILE THERE APPEARS TO BE LITTLE INDICATION OF A STRONG SURFACE LOW...MODELS STILL GENERATE 0.25-0.50 INCH QPF AMTS ALONG THE BAROCLINIC ZONE. THERMAL PROFILES SEEM TO FAVOR SNOW ACROSS THE NW 1/2 OF CENTRAL PA WITH MIXED PTYPES IN THE SOUTH/SOUTHEAST. PRELIMINARY 24HR SNOW/ICE AMOUNTS WERE DERIVED USING A MULTI MODEL QPF BLEND WITH PSEUDO INTERNAL BIAS CORRECTION FACTOR AND WPC WWD. THIS RESULTS IN ADVY LEVEL SNOWFALL OVER THE NW 1/2 AND 0.10 INCH ICE/ZR OVER THE LWR SUSQ VLY. CONFIDENCE IN THE AMTS IS AVG AT BEST GIVEN UNCERTAINTY IN QPF AND LOW-LEVEL TEMPERATURES. THE LACK OF A DEFINED SFC CYCLONE ALSO RAISES SOME REG FLAGS. ANOTHER COLD HP SYSTEM BUILDS INTO THE REGION MON-TUE WITH ANOTHER SW FLOW WAA MSTR SURGE ALONG BAROCLINIC FRONTAL ZONE LKLY IMPACTING THE AREA INTO THE MIDDLE OF NEXT WEEK. TIMING DIFFERENCES ARE EVIDENT WITH THE GFS MORE BULLISH ON PCPN RETURNING EARLY TUE VS. SLOWER ECMWF (TUE NGT). MIXED PTYPE ISSUES ARE EXPECTED AGAIN WITH THIS NEXT SYSTEM. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... LARGE-SCALE FORCING AHEAD OF A SHORTWAVE OVER THE GREAT LAKES BRINGING SOME LIGHT SNOW TO PORTIONS OF CENTRAL MTNS EARLY THIS MORNING. THIS WILL REDUCE VSBYS/CIGS TO MVFR /OCCASIONAL IFR/ PRIMARILY OVER THE WESTERN HIGHER TERRAIN THROUGH 12Z. BRIEF PERIOD OF MVFR CIGS POSS FURTHER EAST THROUGH 10Z. ANOTHER PUSH OF ARCTIC AIR ARRIVES IMMEDIATELY BEHIND THE SHORTWAVE FOR FRI. OROGRAPHIC FLOW WILL KEEP MVFR CONDITIONS IN WESTERN HIGHER TERRAIN THROUGH MIDDAY...WITH IMPROVING CONDITIONS IN THE AFTERNOON AS ANOMALOUSLY STRONG 1040-1045 MB SFC HIGH PRESSURE BUILDS INTO THE COMMONWEALTH FROM THE OHIO VALLEY. VFR WILL BE THE RULE IN CENTRAL AND EAST. WINDS WILL BE W/NW AT AROUND 10 MPH. OUTLOOK... FRI NIGHT AND SAT...NO SIG WX EXPECTED. SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE. MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM. TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE. && .CLIMATE... THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY MEAN TEMPERATURES THROUGH THE 26TH...IPT 18.2...MDT 20.7. THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET IN 1934. SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH COLDEST EVER AT MDT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...STEINBUGL AVIATION...RXR CLIMATE...
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1154 AM CST FRI FEB 27 2015 .UPDATE... UPDATED TO INCLUDE THE 18Z AVIATION DISCUSSION BELOW. JCL && .DISCUSSION... /ISSUED 1041 AM CST FRI FEB 27 2015/ WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILE TRENDS INDICATE A SUBTLE MID-LEVEL SHORTWAVE TROUGH LOCATED ACROSS OKLAHOMA LATE THIS MORNING. THIS IS PRODUCING SOME SNOW NEAR THE TEXAS/OKLAHOMA PANHANDLE. MEANWHILE...ACROSS THE MID SOUTH SUNNY TO MOSTLY SUNNY SKIES ARE PREVAILING WITH TEMPERATURES AS OF 10 AM CST IN THE TEENS ACROSS THE NORTHERN THIRD OF THE MID SOUTH AND 20S ACROSS THE REMAINDER OF THE FORECAST AREA. LATEST SHORT TERM MODEL TRENDS INDICATE THIS PRECIPITATION MAY ENTER PORTIONS OF THE MIDDLE AND LOWER MISSISSIPPI VALLEYS LATER THIS AFTERNOON INTO TONIGHT. HOWEVER...CONFIDENCE REMAINS LOW WITH ANY PRECIPITATION ENTERING EXTREME NORTHEAST ARKANSAS. THUS...WILL REMOVE THE POPS IN FOR LATE AFTERNOON/THIS EVENING UNTIL TRENDS SUGGEST OTHERWISE. WILL MAKE SOME ADJUSTMENTS TO SKY COVER AND ANY OTHER ELEMENTS AS NEEDED TO ACCOUNT FOR CURRENT SHORT TERM TRENDS. UPDATED GRIDS WILL BE AVAILABLE SHORTLY. CJC PREV DISCUSSION... /ISSUED 714 AM CST FRI FEB 27 2015/ UPDATED FORECAST TO ADD A SMALL CHANCE OF LIGHT SNOW ACROSS NE AR LATER TODAY INTO TONIGHT. LATEST GUIDANCE SUGGESTS THAT SOME OF THE SNOW OVER THE SOUTHERN PLAINS MAY REACH NW PARTS OF THE MIDSOUTH. 11Z HRRR INDICATES THIS POSSIBILITY AND MAV MOS POPS ALSO HINT AT IT. SJM PREV DISCUSSION... /ISSUED 418 AM CST FRI FEB 27 2015/ CURRENTLY...ARCTIC HIGH PRESSURE IS SETTLING ACROSS THE MID MISSISSIPPI VALLEY. STRONG COLD AIR ADVECTION CONTINUES ACROSS THE AREA WITH SCT-BKN LOW CLOUDS AND A FEW FLURRIES. TEMPS RANGE FROM THE UPPER TEENS NORTH TO UPPER 20S SOUTH WITH WIND CHILLS IN THE SINGLE DIGITS NORTH TO TEENS SOUTH. TODAY...ARCTIC HIGH PRESSURE BEGINS TO SLIDE FROM THE MIDDLE MISSISSIPPI VALLEY INTO THE OHIO VALLEY. A WEAK UPPER LEVEL DISTURBANCE WILL GENERATE SOME LIGHT SNOW OVER WRN OKLAHOMA AND THE RED RIVER VALLEY THIS AFTERNOON BUT THIS AREA IS EXPECTED TO DISSIPATE AS IT MOVES ACROSS ARKANSAS. WOULD NOT BE SURPRISED TO SEE A FEW FLAKES ACROSS NE ARKANSAS BUT AT THIS POINT NOT CONFIDENT ENOUGH TO INTRODUCE INTO THE FORECAST. SHOULD SEE SOME SUN THIS MORNING FOLLOWED BY AND INCREASE IN MIDDLE AND HIGH CLOUDS THIS AFTERNOON. EXPECT A VERY COLD DAY WITH HIGHS IN THE MID 20S NORTH TO MID 30S SOUTH. THE AVERAGE HIGH IN MEMPHIS IS 58F. TONIGHT...HIGH PRESSURE REMAINS IN CONTROL. EXPECT A GOOD DEAL OF MID AND HIGH CLOUDINESS SO TEMPS WILL NOT GET RIDICULOUSLY COLD...JUST VERY COLD. BY MORNING LOW TEMPS WILL RANGE FROM 20-25F. SATURDAY...ARCTIC HIGH MOVES OFF TO THE MID ATLANTIC AND SLOWLY LOOSES ITS GRIP ON THE MIDSOUTH. SHOULD SEE AT LEAST SOME SUN WITH TEMPS CLIMBING INTO THE UPPER 30S TO UPPER 40S. BREAK OUT THE LAWN CHAIRS. SATURDAY NIGHT THROUGH MONDAY...AN WEAK UPPER LEVEL DISTURBANCE MOVING ACROSS OK/MO WILL RESULT IN A SLIGHT CHANCE OF RAIN ACROSS THE AREA SATURDAY NIGHT...PERHAPS A LITTLE FREEZING RAIN OVER NE AR. BY SUNDAY A MORE IMPRESSIVE MID LEVEL TROUGH MOVING THROUGH THE GREAT LAKES WILL PUSH A COLD FRONT INTO THE MIDSOUTH WITH RAIN CHANCES INCREASING SUNDAY INTO MONDAY. TEMPS WILL WARM INTO THE 50S MOST PLACES AHEAD OF THE FRONT ON SUNDAY. ON MONDAY TEMPS WILL SLIGHTLY COOLER WITH HIGH PRESSURE BUILDING TO THE NORTH. PRECIP CHANCE SHOULD TAIL OFF ACROSS THE NORTH ON MONDAY. MONDAY NIGHT INTO WEDNESDAY...MAJOR DIFFERENCES IN TIMING BETWEEN GFS AND ECWMF. A MAJOR UPPER LEVEL TROF WILL DEVELOP OVER THE WESTERN U.S. EARLY IN THE WEEK AND THERE ARE DIFFERENCES BETWEEN THE MODELS AS TO WHEN IT WILL PUSH INTO THE MIDDLE OF THE COUNTRY. THE GFS IS MUCH FASTER...PUSHING AN ACTIVE WARM FRONT NORTH EARLY TUESDAY WITH SURFACE LOW PRESSURE MOVING THROUGH THE MIDDLE MISSISSIPPI VALLEY THEN A COLD FRONT WILL MOVE THROUGH TUESDAY NIGHT. THE ECMWF PUSHES THE WARM FRONT THROUGH LATER TUESDAY AND THE COLD FRONT THROUGH DURING THE DAY ON WEDNESDAY. AT THIS POINT WILL TAKE THE COMPROMISE APPROACH AND SPREAD FAIRLY HIGH POPS THROUGH THE PERIOD. AHEAD OF THE COLD FRONT SURFACE DEWPOINTS CLIMB INTO THE 60S AND THERE ARE INDICATIONS THAT SOME INSTABILITY WILL BE PRESENT SO WILL NEED TO WATCH THE TUESDAY NIGHT-WEDNESDAY PERIOD FOR SEVERE POTENTIAL. EXPECT HIGHS IN THE 60S AND SOME 70S TUESDAY. HIGHS ON WEDNESDAY WILL BE HIGHLY DEPENDENT ON WHETHER THE FRONT HAS GONE THROUGH. WEDNESDAY NIGHT THROUGH THURSDAY...PRECIP WRAPPING UP AND MUCH COLDER. THE GFS HAS A MUCH COLDER BLAST BEHIND THIS SYSTEM BUT WILL TEMPER THAT GIVEN THE ECMWF SOLUTION. NONETHELESS BELOW NORMAL TEMPS EXPECTED ONCE AGAIN FOR THE END OF THE WEEK. SJM && .AVIATION... 18Z TAF CYCLE (27/18Z-28/18Z) OCCASIONAL MVFR CEILINGS WILL OCCUR AT KMEM UNTIL 19Z...OTHERWISE VFR CONDITIONS WILL OCCUR AT THE TAF SITES THROUGH THE PERIOD. WINDS THIS AFTERNOON NE WINDS 10-12 KTS. WINDS TONIGHT NE 8-11 KTS. WINDS SATURDAY MORNING NE-E 7-8 KTS. JCL && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1041 AM CST FRI FEB 27 2015 .DISCUSSION...WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILE TRENDS INDICATE A SUBTLE MID-LEVEL SHORTWAVE TROUGH LOCATED ACROSS OKLAHOMA LATE THIS MORNING. THIS IS PRODUCING SOME SNOW NEAR THE TEXAS/OKLAHOMA PANHANDLE. MEANWHILE...ACROSS THE MID SOUTH SUNNY TO MOSTLY SUNNY SKIES ARE PREVAILING WITH TEMPERATURES AS OF 10 AM CST IN THE TEENS ACROSS THE NORTHERN THIRD OF THE MID SOUTH AND 20S ACROSS THE REMAINDER OF THE FORECAST AREA. LATEST SHORT TERM MODEL TRENDS INDICATE THIS PRECIPITATION MAY ENTER PORTIONS OF THE MIDDLE AND LOWER MISSISSIPPI VALLEYS LATER THIS AFTERNOON INTO TONIGHT. HOWEVER...CONFIDENCE REMAINS LOW WITH ANY PRECIPITATION ENTERING EXTREME NORTHEAST ARKANSAS. THUS...WILL REMOVE THE POPS IN FOR LATE AFTERNOON/THIS EVENING UNTIL TRENDS SUGGEST OTHERWISE. WILL MAKE SOME ADJUSTMENTS TO SKY COVER AND ANY OTHER ELEMENTS AS NEEDED TO ACCOUNT FOR CURRENT SHORT TERM TRENDS. UPDATED GRIDS WILL BE AVAILABLE SHORTLY. CJC && .PREV DISCUSSION... /ISSUED 714 AM CST FRI FEB 27 2015/ DISCUSSION... UPDATED FORECAST TO ADD A SMALL CHANCE OF LIGHT SNOW ACROSS NE AR LATER TODAY INTO TONIGHT. LATEST GUIDANCE SUGGESTS THAT SOME OF THE SNOW OVER THE SOUTHERN PLAINS MAY REACH NW PARTS OF THE MIDSOUTH. 11Z HRRR INDICATES THIS POSSIBILITY AND MAV MOS POPS ALSO HINT AT IT. SJM PREV DISCUSSION... /ISSUED 418 AM CST FRI FEB 27 2015/ CURRENTLY...ARCTIC HIGH PRESSURE IS SETTLING ACROSS THE MID MISSISSIPPI VALLEY. STRONG COLD AIR ADVECTION CONTINUES ACROSS THE AREA WITH SCT-BKN LOW CLOUDS AND A FEW FLURRIES. TEMPS RANGE FROM THE UPPER TEENS NORTH TO UPPER 20S SOUTH WITH WIND CHILLS IN THE SINGLE DIGITS NORTH TO TEENS SOUTH. TODAY...ARCTIC HIGH PRESSURE BEGINS TO SLIDE FROM THE MIDDLE MISSISSIPPI VALLEY INTO THE OHIO VALLEY. A WEAK UPPER LEVEL DISTURBANCE WILL GENERATE SOME LIGHT SNOW OVER WRN OKLAHOMA AND THE RED RIVER VALLEY THIS AFTERNOON BUT THIS AREA IS EXPECTED TO DISSIPATE AS IT MOVES ACROSS ARKANSAS. WOULD NOT BE SURPRISED TO SEE A FEW FLAKES ACROSS NE ARKANSAS BUT AT THIS POINT NOT CONFIDENT ENOUGH TO INTRODUCE INTO THE FORECAST. SHOULD SEE SOME SUN THIS MORNING FOLLOWED BY AND INCREASE IN MIDDLE AND HIGH CLOUDS THIS AFTERNOON. EXPECT A VERY COLD DAY WITH HIGHS IN THE MID 20S NORTH TO MID 30S SOUTH. THE AVERAGE HIGH IN MEMPHIS IS 58F. TONIGHT...HIGH PRESSURE REMAINS IN CONTROL. EXPECT A GOOD DEAL OF MID AND HIGH CLOUDINESS SO TEMPS WILL NOT GET RIDICULOUSLY COLD...JUST VERY COLD. BY MORNING LOW TEMPS WILL RANGE FROM 20-25F. SATURDAY...ARCTIC HIGH MOVES OFF TO THE MID ATLANTIC AND SLOWLY LOOSES ITS GRIP ON THE MIDSOUTH. SHOULD SEE AT LEAST SOME SUN WITH TEMPS CLIMBING INTO THE UPPER 30S TO UPPER 40S. BREAK OUT THE LAWN CHAIRS. SATURDAY NIGHT THROUGH MONDAY...AN WEAK UPPER LEVEL DISTURBANCE MOVING ACROSS OK/MO WILL RESULT IN A SLIGHT CHANCE OF RAIN ACROSS THE AREA SATURDAY NIGHT...PERHAPS A LITTLE FREEZING RAIN OVER NE AR. BY SUNDAY A MORE IMPRESSIVE MID LEVEL TROUGH MOVING THROUGH THE GREAT LAKES WILL PUSH A COLD FRONT INTO THE MIDSOUTH WITH RAIN CHANCES INCREASING SUNDAY INTO MONDAY. TEMPS WILL WARM INTO THE 50S MOST PLACES AHEAD OF THE FRONT ON SUNDAY. ON MONDAY TEMPS WILL SLIGHTLY COOLER WITH HIGH PRESSURE BUILDING TO THE NORTH. PRECIP CHANCE SHOULD TAIL OFF ACROSS THE NORTH ON MONDAY. MONDAY NIGHT INTO WEDNESDAY...MAJOR DIFFERENCES IN TIMING BETWEEN GFS AND ECWMF. A MAJOR UPPER LEVEL TROF WILL DEVELOP OVER THE WESTERN U.S. EARLY IN THE WEEK AND THERE ARE DIFFERENCES BETWEEN THE MODELS AS TO WHEN IT WILL PUSH INTO THE MIDDLE OF THE COUNTRY. THE GFS IS MUCH FASTER...PUSHING AN ACTIVE WARM FRONT NORTH EARLY TUESDAY WITH SURFACE LOW PRESSURE MOVING THROUGH THE MIDDLE MISSISSIPPI VALLEY THEN A COLD FRONT WILL MOVE THROUGH TUESDAY NIGHT. THE ECMWF PUSHES THE WARM FRONT THROUGH LATER TUESDAY AND THE COLD FRONT THROUGH DURING THE DAY ON WEDNESDAY. AT THIS POINT WILL TAKE THE COMPROMISE APPROACH AND SPREAD FAIRLY HIGH POPS THROUGH THE PERIOD. AHEAD OF THE COLD FRONT SURFACE DEWPOINTS CLIMB INTO THE 60S AND THERE ARE INDICATIONS THAT SOME INSTABILITY WILL BE PRESENT SO WILL NEED TO WATCH THE TUESDAY NIGHT-WEDNESDAY PERIOD FOR SEVERE POTENTIAL. EXPECT HIGHS IN THE 60S AND SOME 70S TUESDAY. HIGHS ON WEDNESDAY WILL BE HIGHLY DEPENDENT ON WHETHER THE FRONT HAS GONE THROUGH. WEDNESDAY NIGHT THROUGH THURSDAY...PRECIP WRAPPING UP AND MUCH COLDER. THE GFS HAS A MUCH COLDER BLAST BEHIND THIS SYSTEM BUT WILL TEMPER THAT GIVEN THE ECMWF SOLUTION. NONETHELESS BELOW NORMAL TEMPS EXPECTED ONCE AGAIN FOR THE END OF THE WEEK. SJM && .AVIATION... 12Z TAF CYCLE MVFR CIGS WILL LINGER THIS MORNING AT TUP...OTHERWISE THE TAF SITES WILL BE VFR THROUGH THE PERIOD. NORTH TO NORTHEAST WINDS IN THE 10-15 KT RANGE WILL DIMINISH TO 6-9 KTS LATE. JAB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1007 AM EST FRI FEB 27 2015 .DISCUSSION... LIGHT SNOW SHOWERS AND FLURRIES ARE PERSISTING IN SW VA AND NE TN. THE RAP AND HRRR REFLECTIVITY DEPICTIONS ARE NOT PICKING UP ON THIS PRECIP...BUT THE RAP AND NAM SOUNDINGS SHOW SOME SHALLOW MOISTURE THAT EXTENDS INTO THE DENDRITE GROWTH ZONE DUE TO STEEP LAPSE RATES. THEY SHOW THIS CONTINUING INTO THE AFTERNOON...WITH MOISTURE DIMINISHING LATE IN THE DAY. SO WILL UPDATE TO EXTEND THE LOW/SLIGHT CHANCE POP AND MENTION OF FLURRIES INTO THE AFTERNOON. CLOUD COVER IS ALSO LESS THAN CURRENTLY DEPICTED IN THE GRIDS...SO WILL ADJUST SKY COVER DOWNWARD TODAY. TEMPERATURES LOOK ON TRACK SO FAR. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DGS
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
714 AM CST FRI FEB 27 2015 .DISCUSSION... UPDATED FORECAST TO ADD A SMALL CHANCE OF LIGHT SNOW ACROSS NE AR LATER TODAY INTO TONIGHT. LATEST GUIDANCE SUGGESTS THAT SOME OF THE SNOW OVER THE SOUTHERN PLAINS MAY REACH NW PARTS OF THE MIDSOUTH. 11Z HRRR INDICATES THIS POSSIBILITY AND MAV MOS POPS ALSO HINT AT IT. SJM && PREV DISCUSSION... /ISSUED 418 AM CST FRI FEB 27 2015/ CURRENTLY...ARCTIC HIGH PRESSURE IS SETTLING ACROSS THE MID MISSISSIPPI VALLEY. STRONG COLD AIR ADVECTION CONTINUES ACROSS THE AREA WITH SCT-BKN LOW CLOUDS AND A FEW FLURRIES. TEMPS RANGE FROM THE UPPER TEENS NORTH TO UPPER 20S SOUTH WITH WIND CHILLS IN THE SINGLE DIGITS NORTH TO TEENS SOUTH. TODAY...ARCTIC HIGH PRESSURE BEGINS TO SLIDE FROM THE MIDDLE MISSISSIPPI VALLEY INTO THE OHIO VALLEY. A WEAK UPPER LEVEL DISTURBANCE WILL GENERATE SOME LIGHT SNOW OVER WRN OKLAHOMA AND THE RED RIVER VALLEY THIS AFTERNOON BUT THIS AREA IS EXPECTED TO DISSIPATE AS IT MOVES ACROSS ARKANSAS. WOULD NOT BE SURPRISED TO SEE A FEW FLAKES ACROSS NE ARKANSAS BUT AT THIS POINT NOT CONFIDENT ENOUGH TO INTRODUCE INTO THE FORECAST. SHOULD SEE SOME SUN THIS MORNING FOLLOWED BY AND INCREASE IN MIDDLE AND HIGH CLOUDS THIS AFTERNOON. EXPECT A VERY COLD DAY WITH HIGHS IN THE MID 20S NORTH TO MID 30S SOUTH. THE AVERAGE HIGH IN MEMPHIS IS 58F. TONIGHT...HIGH PRESSURE REMAINS IN CONTROL. EXPECT A GOOD DEAL OF MID AND HIGH CLOUDINESS SO TEMPS WILL NOT GET RIDICULOUSLY COLD...JUST VERY COLD. BY MORNING LOW TEMPS WILL RANGE FROM 20-25F. SATURDAY...ARCTIC HIGH MOVES OFF TO THE MID ATLANTIC AND SLOWLY LOOSES ITS GRIP ON THE MIDSOUTH. SHOULD SEE AT LEAST SOME SUN WITH TEMPS CLIMBING INTO THE UPPER 30S TO UPPER 40S. BREAK OUT THE LAWN CHAIRS. SATURDAY NIGHT THROUGH MONDAY...AN WEAK UPPER LEVEL DISTURBANCE MOVING ACROSS OK/MO WILL RESULT IN A SLIGHT CHANCE OF RAIN ACROSS THE AREA SATURDAY NIGHT...PERHAPS A LITTLE FREEZING RAIN OVER NE AR. BY SUNDAY A MORE IMPRESSIVE MID LEVEL TROUGH MOVING THROUGH THE GREAT LAKES WILL PUSH A COLD FRONT INTO THE MIDSOUTH WITH RAIN CHANCES INCREASING SUNDAY INTO MONDAY. TEMPS WILL WARM INTO THE 50S MOST PLACES AHEAD OF THE FRONT ON SUNDAY. ON MONDAY TEMPS WILL SLIGHTLY COOLER WITH HIGH PRESSURE BUILDING TO THE NORTH. PRECIP CHANCE SHOULD TAIL OFF ACROSS THE NORTH ON MONDAY. MONDAY NIGHT INTO WEDNESDAY...MAJOR DIFFERENCES IN TIMING BETWEEN GFS AND ECWMF. A MAJOR UPPER LEVEL TROF WILL DEVELOP OVER THE WESTERN U.S. EARLY IN THE WEEK AND THERE ARE DIFFERENCES BETWEEN THE MODELS AS TO WHEN IT WILL PUSH INTO THE MIDDLE OF THE COUNTRY. THE GFS IS MUCH FASTER...PUSHING AN ACTIVE WARM FRONT NORTH EARLY TUESDAY WITH SURFACE LOW PRESSURE MOVING THROUGH THE MIDDLE MISSISSIPPI VALLEY THEN A COLD FRONT WILL MOVE THROUGH TUESDAY NIGHT. THE ECMWF PUSHES THE WARM FRONT THROUGH LATER TUESDAY AND THE COLD FRONT THROUGH DURING THE DAY ON WEDNESDAY. AT THIS POINT WILL TAKE THE COMPROMISE APPROACH AND SPREAD FAIRLY HIGH POPS THROUGH THE PERIOD. AHEAD OF THE COLD FRONT SURFACE DEWPOINTS CLIMB INTO THE 60S AND THERE ARE INDICATIONS THAT SOME INSTABILITY WILL BE PRESENT SO WILL NEED TO WATCH THE TUESDAY NIGHT-WEDNESDAY PERIOD FOR SEVERE POTENTIAL. EXPECT HIGHS IN THE 60S AND SOME 70S TUESDAY. HIGHS ON WEDNESDAY WILL BE HIGHLY DEPENDENT ON WHETHER THE FRONT HAS GONE THROUGH. WEDNESDAY NIGHT THROUGH THURSDAY...PRECIP WRAPPING UP AND MUCH COLDER. THE GFS HAS A MUCH COLDER BLAST BEHIND THIS SYSTEM BUT WILL TEMPER THAT GIVEN THE ECMWF SOLUTION. NONETHELESS BELOW NORMAL TEMPS EXPECTED ONCE AGAIN FOR THE END OF THE WEEK. SJM && .AVIATION... 12Z TAF CYCLE MVFR CIGS WILL LINGER THIS MORNING AT TUP...OTHERWISE THE TAF SITES WILL BE VFR THROUGH THE PERIOD. NORTH TO NORTHEAST WINDS IN THE 10-15 KT RANGE WILL DIMINISH TO 6-9 KTS LATE. JAB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1151 AM CST FRI FEB 27 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...HIGH CLOUDS ARE EXPECTED TO DECREASE AS THE UPPER JET SHIFTS DOWNSTREAM. COLD AIR BEHIND A COLD FRONT IS FILTERING INTO THE WESTERN PORTION OF THE CWA THIS MORNING...AND THE ISENTROPIC LIFT WILL SUPPORT LOWERING CEILINGS...WITH LIGHT RAIN AND DRIZZLE STARTING TO MOVE INLAND. THIS RAIN WILL GRADUALLY BE ON THE INCREASE DURING THE DAY. A VERY SHARP TEMPERATURE GRADIENT WITH A WARM AIR MASS FROM HWY 77 EAST AND COLDER WEST OF 77 ASOCIATED TO THIS COLD FRONT. AS THE COASTAL TROUGH STRENGTHENS THE WINDS SHIFT MORE NORTHERLY LATER INTO TONIGHT. THIS TROUGH WILL EVENTUALLY BE LIFTED NORTHEAST WITH COLD AIR MASS FROM THE WEST TAKING CONTROL AND FILTERING IN THROUGH THE AREA. THE WINDS WILL BEGIN TO SHIFT NORTHWEST CLOSER TO MIDNIGHT AND WESTERLY INTO SATURDAY. && .PREV DISCUSSION... /ISSUED 1035 AM CST FRI FEB 27 2015/ DISCUSSION...THE COLD AIR CONTINUES TO MOVE SOUTH ACROSS THE CWA ESPECIALLY TOWARDS THE WESTERN PORTION OF THE CWA. THIS HAS SHIFTED WINDS MORE NORTHWEST KEEPING TEMPERATURES COOLER THAN EXPECTED. KEPT A NORTH TO NORTHWEST FLOW ACROSS THE AREA WITH A SHARP TEMPERATURE GRADIENT FROM WEST TO EAST. LOWER HIGH TEMPERATURES A FEW DEGREES MORE TOWARDS THE WEST AND WITH A EASTERLY FLOW DEVELOPING KEPT WARMER TEMPERATURES IN THE MID 60S. CHANCE OF RAIN REMAINS THE SAME AND THERE ARE NO OTHER CHANGES DONE TO THE FORECAST AT THIS TIME. PREV DISCUSSION... /ISSUED 547 AM CST FRI FEB 27 2015/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...HIGH CLOUDS ARE EXPECTED TO DECREASE AS THE UPPER JET SHIFTS DOWNSTREAM. COLD AIR BEHIND A COLD FRONT IS FILTERING INTO THE CWA THIS MORNING...AND THE ISENTROPIC LIFT WILL SUPPORT LOWERING CEILINGS...WITH LIGHT RAIN AND DRIZZLE POSSIBLE LATER IN THE DAY. LIGHT TO MODERATE NORTHEAST WINDS WILL BECOME VERY LIGHT THIS EVE...BUT WILL THEN PICK UP AGAIN SLIGHTLY AFTER MIDNIGHT. CEILINGS SHOULD LOWER TO MVFR BY MID MORNING AND THEN TO IFR LATER TODAY. THE GUIDANCE VARIES A LITTLE FOR THIS EVENING...WITH THE GFS KEEPING CEILINGS A CATEGORY HIGHER THAN THE NAM...BUT MVFR IS THE MIDDLE GROUND FOR NOW. && PREV DISCUSSION... /ISSUED 254 AM CST FRI FEB 27 2015/ SHORT TERM /NOW THROUGH SATURDAY/...A COLD FRONT IS WORKING ITS WAY THROUGH THE CWA THIS MORNING...WITHOUT TOO MUCH FANFARE. SOUTHERN EDGE AND RR QUAD OF AN UPPER JET STREAK RESULTED IN A RIBBON OF UPPER CLOUDS STILL OVER THE SOUTHEASTERN CORNER OF THE CWA BUT THAT SHOULD FADE TODAY AS THICKER LOW CLOUDS TAKE OVER. LOW CLOUDS ARE THICKENING FROM WEST TO EAST. NORTHEAST WINDS THAT WERE ALREADY IN PLACE ARE RECEIVING SOME REINFORCEMENT AND DEW POINTS ARE DECREASING BEHIND THE FRONT. LOOKING FOR A COOL...CLOUDY DAY ACROSS DEEP SOUTH TEXAS AND THE RGV TODAY WITH A RANGE OF HIGH TEMPS FROM THE UPPER 40S FAR WEST AND NORTH TO THE LOWER 60S FOR CAMERON AND WILLACY COUNTIES. LIGHT RAIN AND DRIZZLE CHANCES WILL INCREASE LATER TODAY AND TONIGHT AS THE COOLER AIR BECOMES ESTABLISHED. LOW TEMPS TONIGHT WILL BE MAINLY IN THE 40S AND 50S WITH LIGHT WINDS AS HIGH PRESSURE SPREADS OVER THE AREA. LOOKS LIKE THE HIGH PRESSURE WILL THEN SHIFT EAST IN SHORT ORDER. WINDS WILL VEER TO EAST BY SATURDAY AND THE RETURN FLOW WILL SUPPORT HIGH TEMPS IN THE 60S...THOUGH AMPLE CLOUD COVER WILL CONTINUE AND A MID LEVEL FLOW THAT WILL BACK FROM WEST TO SOUTHWEST WILL HELP ENSURE THAT OVERRUNNING PERSISTS. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...OVERRUNNING LIGHT RAIN CHANCES ACROSS DEEP SOUTH TEXAS AND THE RGV WILL COME TO AN END SUNDAY AS COASTAL TROUGHING WEAKENS AND A WARM FRONT LIFTS NORTHWARD. WINDS BECOME SOUTHEASTERLY BY SUNDAY MORNING AND MOISTURE DECREASES. COLD AIR IS SHUNTED NORTH AND EAST FOR THE START OF THE WORK WEEK WITH 850MB TEMPERATURES RISING FROM 13C SUNDAY MORNING TO 22C BY TUESDAY NIGHT. 700MB SOUTHWESTERLIES SPREAD OVER THE AREA BEGINNING MONDAY NIGHT. WHAT THIS MEANS IS HIGH TEMPERATURES MONDAY AND TUESDAY WILL BE IN THE 80S WITH LOW 90S OUT WEST WHERE MID LEVEL DRY AIR DUE TO THOSE AFOREMENTIONED SOUTHWESTERLIES WILL BE MIXED DOWN. AN UPPER TROF WILL MOVE OVER THE WESTERN CONUS AND FOUR CORNERS THROUGH TUESDAY. PRESSURE FALLS AHEAD OF THIS FEATURE WILL INDUCE LEE TROUGHING ACROSS THE ROCKIES SOUTHWARD INTO THE SIERRA MADRES. THIS WILL HELP RATCHET UP THE SOUTHERLY SURFACE WINDS MONDAY AND TUESDAY AS WELL. SURFACE LOW PRESSURE WILL HEAD OUT OF THE HIGH PLAINS TUESDAY AND DRAG A COLD FRONT INTO CENTRAL AND SOUTHERN TEXAS WEDNESDAY. WIDESPREAD STRATUS ON A 40KT LOW LEVEL JET WILL KEEP THE AREA MOSTLY CLOUDY THROUGH THE DAY WHICH WILL HOLD HIGH TEMPERATURES DOWN INTO THE LOW 80S. TIMING DIFFERENCES EXIST BETWEEN THE GFS/ECMWF CONCERNING THE PASSAGE OF THE FRONT WITH GFS A LITTLE FASTER BRINGING THE FRONT THROUGH WEDNESDAY AND THE ECMWF AT WEDNESDAY NIGHT AND THURSDAY. DESPITE THE TIMING DIFFERENCES EXPECT STRONG NORTHERLY WINDS AND COOLER TEMPERATURES TO ROUND OUT THE WORK WEEK. AS FAR AS POPS GO ASSOCIATED WITH THE FRONT LOOKS LIKE CAPPING WILL BE STRONG AND LIMIT MOST PRECIPITATION TO WELL OFFSHORE. BOTH ECMWF AND GFS HINT AT WEAK COASTAL TROUGHING FRIDAY WITH A SLIGHT CHANCE FOR LIGHT RAIN ALONG AND EAST OF HWY 77. MARINE /NOW THROUGH THROUGH SATURDAY/...STRONG HIGH PRESSURE OVER THE PLAINS WILL EXTEND SOUTH OVER THE NORTH GULF AND WILL SET UP MDT TO FRESH EAST NORTHEAST WINDS...BUT PERHAPS OF MORE SIGNIFICANCE WILL BE THE LONG FETCH ACROSS THE NORTH GULF...WHICH WILL SUPPORT ELEVATED SEAS DUE TO A SWELL COMPONENT. THE ONGOING SMALL CRAFT ADVISORY FOR THE GULF WILL THUS PERSIST THROUGH THE SHORT TERM. WAVE HEIGHTS OF 7 TO 9 FEET WILL PERSIST ON THE OPEN GULF THROUGH SATURDAY AND INTO THE LONG TERM. SATURDAY NIGHT THROUGH TUESDAY...MODERATE TO STRONG EAST WINDS SATURDAY NIGHT WILL WEAKEN AND TURN MORE SOUTHEASTERLY SUNDAY AS A WARM FRONT MOVES NORTHWARD THROUGH THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL BE ONGOING INTO THE LONG TERM AND WILL BE NEED THROUGH SUNDAY AS SEA HEIGHTS WILL REMAIN AROUND 7 FEET THROUGH SUNDAY AFTERNOON. WINDS AND SEAS BECOME MORE MODERATE MONDAY WITH CONDITIONS DETERIORATING MONDAY NIGHT AND TUESDAY AS LOW PRESSURE DEEPENS TO OUR WEST AND SOUTHEASTERLY WINDS STRENGTHEN. SMALL CRAFT ADVISORIES WILL BE LIKELY MONDAY NIGHT INTO TUESDAY. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 3 AM CST SATURDAY FOR GMZ150-155-170- 175. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 67/52
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1035 AM CST FRI FEB 27 2015 .DISCUSSION...THE COLD AIR CONTINUES TO MOVE SOUTH ACROSS THE CWA ESPECIALLY TOWARDS THE WESTERN PORTION OF THE CWA. THIS HAS SHIFTED WINDS MORE NORTHWEST KEEPING TEMPERATURES COOLER THAN EXPECTED. KEPT A NORTH TO NORTHWEST FLOW ACROSS THE AREA WITH A SHARP TEMPERATURE GRADIENT FROM WEST TO EAST. LOWER HIGH TEMPERATURES A FEW DEGREES MORE TOWARDS THE WEST AND WITH A EASTERLY FLOW DEVELOPING KEPT WARMER TEMPERATURES IN THE MID 60S. CHANCE OF RAIN REMAINS THE SAME AND THERE ARE NO OTHER CHANGES DONE TO THE FORECAST AT THIS TIME. && .PREV DISCUSSION... /ISSUED 547 AM CST FRI FEB 27 2015/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...HIGH CLOUDS ARE EXPECTED TO DECREASE AS THE UPPER JET SHIFTS DOWNSTREAM. COLD AIR BEHIND A COLD FRONT IS FILTERING INTO THE CWA THIS MORNING...AND THE ISENTROPIC LIFT WILL SUPPORT LOWERING CEILINGS...WITH LIGHT RAIN AND DRIZZLE POSSIBLE LATER IN THE DAY. LIGHT TO MODERATE NORTHEAST WINDS WILL BECOME VERY LIGHT THIS EVE...BUT WILL THEN PICK UP AGAIN SLIGHTLY AFTER MIDNIGHT. CEILINGS SHOULD LOWER TO MVFR BY MID MORNING AND THEN TO IFR LATER TODAY. THE GUIDANCE VARIES A LITTLE FOR THIS EVENING...WITH THE GFS KEEPING CEILINGS A CATEGORY HIGHER THAN THE NAM...BUT MVFR IS THE MIDDLE GROUND FOR NOW. && PREV DISCUSSION... /ISSUED 254 AM CST FRI FEB 27 2015/ SHORT TERM /NOW THROUGH SATURDAY/...A COLD FRONT IS WORKING ITS WAY THROUGH THE CWA THIS MORNING...WITHOUT TOO MUCH FANFARE. SOUTHERN EDGE AND RR QUAD OF AN UPPER JET STREAK RESULTED IN A RIBBON OF UPPER CLOUDS STILL OVER THE SOUTHEASTERN CORNER OF THE CWA BUT THAT SHOULD FADE TODAY AS THICKER LOW CLOUDS TAKE OVER. LOW CLOUDS ARE THICKENING FROM WEST TO EAST. NORTHEAST WINDS THAT WERE ALREADY IN PLACE ARE RECEIVING SOME REINFORCEMENT AND DEW POINTS ARE DECREASING BEHIND THE FRONT. LOOKING FOR A COOL...CLOUDY DAY ACROSS DEEP SOUTH TEXAS AND THE RGV TODAY WITH A RANGE OF HIGH TEMPS FROM THE UPPER 40S FAR WEST AND NORTH TO THE LOWER 60S FOR CAMERON AND WILLACY COUNTIES. LIGHT RAIN AND DRIZZLE CHANCES WILL INCREASE LATER TODAY AND TONIGHT AS THE COOLER AIR BECOMES ESTABLISHED. LOW TEMPS TONIGHT WILL BE MAINLY IN THE 40S AND 50S WITH LIGHT WINDS AS HIGH PRESSURE SPREADS OVER THE AREA. LOOKS LIKE THE HIGH PRESSURE WILL THEN SHIFT EAST IN SHORT ORDER. WINDS WILL VEER TO EAST BY SATURDAY AND THE RETURN FLOW WILL SUPPORT HIGH TEMPS IN THE 60S...THOUGH AMPLE CLOUD COVER WILL CONTINUE AND A MID LEVEL FLOW THAT WILL BACK FROM WEST TO SOUTHWEST WILL HELP ENSURE THAT OVERRUNNING PERSISTS. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...OVERRUNNING LIGHT RAIN CHANCES ACROSS DEEP SOUTH TEXAS AND THE RGV WILL COME TO AN END SUNDAY AS COASTAL TROUGHING WEAKENS AND A WARM FRONT LIFTS NORTHWARD. WINDS BECOME SOUTHEASTERLY BY SUNDAY MORNING AND MOISTURE DECREASES. COLD AIR IS SHUNTED NORTH AND EAST FOR THE START OF THE WORK WEEK WITH 850MB TEMPERATURES RISING FROM 13C SUNDAY MORNING TO 22C BY TUESDAY NIGHT. 700MB SOUTHWESTERLIES SPREAD OVER THE AREA BEGINNING MONDAY NIGHT. WHAT THIS MEANS IS HIGH TEMPERATURES MONDAY AND TUESDAY WILL BE IN THE 80S WITH LOW 90S OUT WEST WHERE MID LEVEL DRY AIR DUE TO THOSE AFOREMENTIONED SOUTHWESTERLIES WILL BE MIXED DOWN. AN UPPER TROF WILL MOVE OVER THE WESTERN CONUS AND FOUR CORNERS THROUGH TUESDAY. PRESSURE FALLS AHEAD OF THIS FEATURE WILL INDUCE LEE TROUGHING ACROSS THE ROCKIES SOUTHWARD INTO THE SIERRA MADRES. THIS WILL HELP RATCHET UP THE SOUTHERLY SURFACE WINDS MONDAY AND TUESDAY AS WELL. SURFACE LOW PRESSURE WILL HEAD OUT OF THE HIGH PLAINS TUESDAY AND DRAG A COLD FRONT INTO CENTRAL AND SOUTHERN TEXAS WEDNESDAY. WIDESPREAD STRATUS ON A 40KT LOW LEVEL JET WILL KEEP THE AREA MOSTLY CLOUDY THROUGH THE DAY WHICH WILL HOLD HIGH TEMPERATURES DOWN INTO THE LOW 80S. TIMING DIFFERENCES EXIST BETWEEN THE GFS/ECMWF CONCERNING THE PASSAGE OF THE FRONT WITH GFS A LITTLE FASTER BRINGING THE FRONT THROUGH WEDNESDAY AND THE ECMWF AT WEDNESDAY NIGHT AND THURSDAY. DESPITE THE TIMING DIFFERENCES EXPECT STRONG NORTHERLY WINDS AND COOLER TEMPERATURES TO ROUND OUT THE WORK WEEK. AS FAR AS POPS GO ASSOCIATED WITH THE FRONT LOOKS LIKE CAPPING WILL BE STRONG AND LIMIT MOST PRECIPITATION TO WELL OFFSHORE. BOTH ECMWF AND GFS HINT AT WEAK COASTAL TROUGHING FRIDAY WITH A SLIGHT CHANCE FOR LIGHT RAIN ALONG AND EAST OF HWY 77. MARINE /NOW THROUGH THROUGH SATURDAY/...STRONG HIGH PRESSURE OVER THE PLAINS WILL EXTEND SOUTH OVER THE NORTH GULF AND WILL SET UP MDT TO FRESH EAST NORTHEAST WINDS...BUT PERHAPS OF MORE SIGNIFICANCE WILL BE THE LONG FETCH ACROSS THE NORTH GULF...WHICH WILL SUPPORT ELEVATED SEAS DUE TO A SWELL COMPONENT. THE ONGOING SMALL CRAFT ADVISORY FOR THE GULF WILL THUS PERSIST THROUGH THE SHORT TERM. WAVE HEIGHTS OF 7 TO 9 FEET WILL PERSIST ON THE OPEN GULF THROUGH SATURDAY AND INTO THE LONG TERM. SATURDAY NIGHT THROUGH TUESDAY...MODERATE TO STRONG EAST WINDS SATURDAY NIGHT WILL WEAKEN AND TURN MORE SOUTHEASTERLY SUNDAY AS A WARM FRONT MOVES NORTHWARD THROUGH THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL BE ONGOING INTO THE LONG TERM AND WILL BE NEED THROUGH SUNDAY AS SEA HEIGHTS WILL REMAIN AROUND 7 FEET THROUGH SUNDAY AFTERNOON. WINDS AND SEAS BECOME MORE MODERATE MONDAY WITH CONDITIONS DETERIORATING MONDAY NIGHT AND TUESDAY AS LOW PRESSURE DEEPENS TO OUR WEST AND SOUTHEASTERLY WINDS STRENGTHEN. SMALL CRAFT ADVISORIES WILL BE LIKELY MONDAY NIGHT INTO TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 63 55 69 64 / 50 40 40 30 BROWNSVILLE 64 53 70 64 / 50 40 30 30 HARLINGEN 56 53 70 63 / 50 40 40 30 MCALLEN 53 48 70 62 / 30 30 20 20 RIO GRANDE CITY 48 46 68 60 / 30 50 30 20 SOUTH PADRE ISLAND 64 56 69 65 / 50 40 40 30 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 3 AM CST SATURDAY FOR GMZ150-155-170- 175. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 67/52
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
254 AM CST FRI FEB 27 2015 .SHORT TERM /NOW THROUGH SATURDAY/...A COLD FRONT IS WORKING ITS WAY THROUGH THE CWA THIS MORNING...WITHOUT TOO MUCH FANFARE. SOUTHERN EDGE AND RR QUAD OF AN UPPER JET STREAK RESULTED IN A RIBBON OF UPPER CLOUDS STILL OVER THE SOUTHEASTERN CORNER OF THE CWA BUT THAT SHOULD FADE TODAY AS THICKER LOW CLOUDS TAKE OVER. LOW CLOUDS ARE THICKENING FROM WEST TO EAST. NORTHEAST WINDS THAT WERE ALREADY IN PLACE ARE RECEIVING SOME REINFORCEMENT AND DEW POINTS ARE DECREASING BEHIND THE FRONT. LOOKING FOR A COOL...CLOUDY DAY ACROSS DEEP SOUTH TEXAS AND THE RGV TODAY WITH A RANGE OF HIGH TEMPS FROM THE UPPER 40S FAR WEST AND NORTH TO THE LOWER 60S FOR CAMERON AND WILLACY COUNTIES. LIGHT RAIN AND DRIZZLE CHANCES WILL INCREASE LATER TODAY AND TONIGHT AS THE COOLER AIR BECOMES ESTABLISHED. LOW TEMPS TONIGHT WILL BE MAINLY IN THE 40S AND 50S WITH LIGHT WINDS AS HIGH PRESSURE SPREADS OVER THE AREA. LOOKS LIKE THE HIGH PRESSURE WILL THEN SHIFT EAST IN SHORT ORDER. WINDS WILL VEER TO EAST BY SATURDAY AND THE RETURN FLOW WILL SUPPORT HIGH TEMPS IN THE 60S...THOUGH AMPLE CLOUD COVER WILL CONTINUE AND A MID LEVEL FLOW THAT WILL BACK FROM WEST TO SOUTHWEST WILL HELP ENSURE THAT OVERRUNNING PERSISTS. .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...OVERRUNNING LIGHT RAIN CHANCES ACROSS DEEP SOUTH TEXAS AND THE RGV WILL COME TO AN END SUNDAY AS COASTAL TROUGHING WEAKENS AND A WARM FRONT LIFTS NORTHWARD. WINDS BECOME SOUTHEASTERLY BY SUNDAY MORNING AND MOISTURE DECREASES. COLD AIR IS SHUNTED NORTH AND EAST FOR THE START OF THE WORK WEEK WITH 850MB TEMPERATURES RISING FROM 13C SUNDAY MORNING TO 22C BY TUESDAY NIGHT. 700MB SOUTHWESTERLIES SPREAD OVER THE AREA BEGINNING MONDAY NIGHT. WHAT THIS MEANS IS HIGH TEMPERATURES MONDAY AND TUESDAY WILL BE IN THE 80S WITH LOW 90S OUT WEST WHERE MID LEVEL DRY AIR DUE TO THOSE AFOREMENTIONED SOUTHWESTERLIES WILL BE MIXED DOWN. AN UPPER TROF WILL MOVE OVER THE WESTERN CONUS AND FOUR CORNERS THROUGH TUESDAY. PRESSURE FALLS AHEAD OF THIS FEATURE WILL INDUCE LEE TROUGHING ACROSS THE ROCKIES SOUTHWARD INTO THE SIERRA MADRES. THIS WILL HELP RATCHET UP THE SOUTHERLY SURFACE WINDS MONDAY AND TUESDAY AS WELL. SURFACE LOW PRESSURE WILL HEAD OUT OF THE HIGH PLAINS TUESDAY AND DRAG A COLD FRONT INTO CENTRAL AND SOUTHERN TEXAS WEDNESDAY. WIDESPREAD STRATUS ON A 40KT LOW LEVEL JET WILL KEEP THE AREA MOSTLY CLOUDY THROUGH THE DAY WHICH WILL HOLD HIGH TEMPERATURES DOWN INTO THE LOW 80S. TIMING DIFFERENCES EXIST BETWEEN THE GFS/ECMWF CONCERNING THE PASSAGE OF THE FRONT WITH GFS A LITTLE FASTER BRINGING THE FRONT THROUGH WEDNESDAY AND THE ECMWF AT WEDNESDAY NIGHT AND THURSDAY. DESPITE THE TIMING DIFFERENCES EXPECT STRONG NORTHERLY WINDS AND COOLER TEMPERATURES TO ROUND OUT THE WORK WEEK. AS FAR AS POPS GO ASSOCIATED WITH THE FRONT LOOKS LIKE CAPPING WILL BE STRONG AND LIMIT MOST PRECIPITATION TO WELL OFFSHORE. BOTH ECMWF AND GFS HINT AT WEAK COASTAL TROUGHING FRIDAY WITH A SLIGHT CHANCE FOR LIGHT RAIN ALONG AND EAST OF HWY 77. && .MARINE /NOW THROUGH THROUGH SATURDAY/...STRONG HIGH PRESSURE OVER THE PLAINS WILL EXTEND SOUTH OVER THE NORTH GULF AND WILL SET UP MDT TO FRESH EAST NORTHEAST WINDS...BUT PERHAPS OF MORE SIGNIFICANCE WILL BE THE LONG FETCH ACROSS THE NORTH GULF...WHICH WILL SUPPORT ELEVATED SEAS DUE TO A SWELL COMPONENT. THE ONGOING SMALL CRAFT ADVISORY FOR THE GULF WILL THUS PERSIST THROUGH THE SHORT TERM. WAVE HEIGHTS OF 7 TO 9 FEET WILL PERSIST ON THE OPEN GULF THROUGH SATURDAY AND INTO THE LONG TERM. SATURDAY NIGHT THROUGH TUESDAY...MODERATE TO STRONG EAST WINDS SATURDAY NIGHT WILL WEAKEN AND TURN MORE SOUTHEASTERLY SUNDAY AS A WARM FRONT MOVES NORTHWARD THROUGH THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL BE ONGOING INTO THE LONG TERM AND WILL BE NEED THROUGH SUNDAY AS SEA HEIGHTS WILL REMAIN AROUND 7 FEET THROUGH SUNDAY AFTERNOON. WINDS AND SEAS BECOME MORE MODERATE MONDAY WITH CONDITIONS DETERIORATING MONDAY NIGHT AND TUESDAY AS LOW PRESSURE DEEPENS TO OUR WEST AND SOUTHEASTERLY WINDS STRENGTHEN. SMALL CRAFT ADVISORIES WILL BE LIKELY MONDAY NIGHT INTO TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 63 55 69 64 / 30 40 40 30 BROWNSVILLE 63 53 70 64 / 30 40 30 30 HARLINGEN 61 53 70 63 / 40 40 40 30 MCALLEN 56 50 70 62 / 30 30 20 20 RIO GRANDE CITY 51 46 68 60 / 30 50 30 20 SOUTH PADRE ISLAND 63 56 69 65 / 30 40 40 30 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 3 AM CST SATURDAY FOR GMZ150-155-170- 175. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV SHORT TERM...54 LONG TERM...55 GRAPHICS/UPPER-AIR...61
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
315 AM EST SUN MAR 01 2015 .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS CONVERGENT UPPER LEVEL FLOW ACROSS THE MID-SECTION OF THE COUNTY AS ONE BRANCH OF THE NORTHER STREAM DIPS INTO THE UPPER MIDWEST/NORTHERN PLAINS...AND A SECOND BRANCH DROPS DOWN THE PACIFIC COAST AROUND A LARGE CUTOFF LOW OVER CALIFORNIA...AND EJECTS OUT OF THE SOUTHWESTERN STATES INTO THE CENTRAL PLAINS. HIGH LEVEL SOUTHERN STREAM MOISTURE CAN BE SEEN VERY WELL ON WV IMAGERY MOVING ACROSS CENTRAL MEXICO...THE GULF OF MEXICO AND OVER THE FL PENINSULA. SOUTH OF THIS SOUTHERN STREAM WE FIND A LARGE WEST-EAST ORIENTED UPPER RIDGE IN PLACE FROM THE BAY OF CAMPECHE ACROSS TO THE WESTERN CARIBBEAN. OVER THE NEXT 36-48 HOURS...AS THE WESTERN TROUGH/CUTOFF LOW DIGS FURTHER SOUTH...AND HEIGHTS FALL ACROSS THE SOUTHWESTERN STATES...THIS WILL FORCE THE DOWNSTREAM RIDGE TO AMPLIFY NORTHWARD OVER THE GULF OF MEXICO AND FLORIDA PENINSULA. ALL THIS TRANSLATES INTO A WARM AND SPRING-LIKE FORECAST FOR OUR REGION DURING THE EARLY AND MIDDLE PORTION OF THE WEEK. AT THE SURFACE...STRONG HIGH PRESSURE CONTINUES TO RIDGE DOWN THE ATLANTIC SEABOARD INTO THE SOUTHEAST CONUS AND WAS THE SET UP FOR THE OVERRUNNING/UPGLIDE PATTERN THAT BROUGHT ALL THE RAIN TO PARTS OF THE REGION ON SATURDAY. THE INFLUENCE OF THIS RIDGE IS JUST NOW BEGINNING TO SLACKEN AS IT WEAKENS AND MOVES OFF INTO THE WESTERN ATLANTIC. THIS ACTION WILL CONTINUE TO WEAKEN THE THE DEPTH OF UPGLIDE REGIME AND SLOWLY SHUT DOWN THE SHOWER PRODUCTION THROUGH THE REMAINDER OF THE EARLY MORNING HOURS. LINGERING UPGLIDE IN THE LOWEST LEVELS ALONG THE 295-300K SURFACES WILL KEEP THE POTENTIAL FOR LOWER STRATUS...AND RESULT IN A DIFFICULT AVIATION FORECAST THROUGH THE MORNING HOURS. HOWEVER...AT LEAST THINGS WILL START TO DRY OUT...TEMPORARILY. && .SHORT TERM (TODAY THROUGH MONDAY)... TODAY... SUNDAY WILL BE A TRANSITION DAY IN THE WEATHER PATTERN FROM ONE DOMINATED BY THE SURFACE HIGH RIDGING DOWN THE ATLANTIC SEABOARD INTO OUR REGION...TO ONE COMING UNDER THE INFLUENCE MORE AND MORE FROM A BUILDING UPPER LEVEL RIDGE OUT OF THE CARIBBEAN. AS MENTIONED IN THE SYNOPSIS...THE DEEP LAYER UPGLIDE IS SHOWN BY MOST NUMERICAL GUIDANCE TO HAVE SHIFTED OFF TO THE NORTHEAST BY SUNRISE...HOWEVER A LOWER LEVEL LAYER OF UPGLIDE WILL STILL BE IN PLACE AND BE HELPING TO SUPPORT AREAS OF LOWER STRATUS INTO THE MORNING HOURS. THIS WILL ESPECIALLY BE TRUE ACROSS THE CENTRAL AND NORTHERN PORTIONS OF THE PENINSULA. FURTHER SOUTH...ON THE OTHER SIDE OF A WEAK BOUNDARY ACROSS THE STATE...EARLY MORNING SATELLITE IMAGERY IS ALREADY SHOWING IMPROVING CONDITIONS (IN TERMS OF CLOUD COVER)...AND THIS SHOULD EXPAND UP INTO OUR SOUTHERN ZONES DURING THE MORNING. OVER TIME WILL SEE MORE AND MORE SUNNY BREAKS FURTHER NORTH AS WELL...AND WILL HAVE EVERYONE GOING PARTLY CLOUDY FOR THE AFTERNOON HOURS. WITH THE SUNNY BREAKS...WE WILL BE SEEING STRONG TERRESTRIAL HEATING...WITH TEMPS CLIMBING WELL UP INTO THE 70S TO THE NORTH OF THE I-4 CORRIDOR...AND INTO THE UPPER 70S/LOWER 80S FURTHER SOUTH. THE LOCAL GRADIENT WILL BE RELAXING OVER TIME AS WELL AS THE SURFACE RIDGE WEAKENS AND EXITS INTO THE WESTERN ATLANTIC. THIS WEAKENING OF THE GRADIENT WILL ALLOW A DECENT SEA-BREEZE CIRCULATION TO DEVELOP AFTER 18Z...AND IN FACT ALL THE HIRES GUIDANCE SHOW THIS TURNING OF THE WINDS ONSHORE NEAR THE COAST. WHILE WE EXPECT THE MORNING TO BE MOSTLY DRY ACROSS THE REGION...WE CAN NOT KEEP THE FORECAST RAIN FREE COMPLETELY FOR THE AFTERNOON AND EVENING HOURS. A COUPLE OF THINGS COME INTO PLAY HERE. THE FIRST IS THE STRONG HEATING OVER LAND WILL ALLOW FOR AT LEAST A FEW HUNDRED J/KG OF BL CAPE THIS AFTERNOON. THE DIFFERENTIAL HEATING ALONG WITH HELPING TO FORCE THE SEA-BREEZE...IS ALSO SHOWING BY THE GUIDANCE SUITE TO STRENGTHEN AN INVERTED SURFACE TROUGH ACROSS THE CENTRAL/WESTERN PORTIONS OF THE PENINSULA FOR THE SECOND HALF OF THE DAY. THIS TROUGH IS PARTICULARLY PRONOUNCED IN THE NAM/SREF AND HIRES MEMBERS. THE TROUGH WILL HELP TO FOCUS LOW LEVEL CONVERGENCE BY MID/LATE AFTERNOON GENERALLY ALONG THE I-75 CORRIDOR. WHEN ONE ADDS THE EVENTUAL ADDITIONAL FOCUS/CONVERGENCE FROM THE SEA-BREEZE...IT BECOMES CLEAR THAT UPDRAFTS SUPPORTING LIMITED CONVECTION CAN NOT BE RULED OUT. IN FACT...THE LAST 4 RUNS OF THE LOCAL WRFARW...ALONG WITH THE LATEST NCEP HIRES RUNS ARE REMARKABLY SIMILAR IN THE PATTERN OF ALLOWED CONVECTION DEVELOPING AFTER 19-20Z ALONG THIS I-75 CORRIDOR. WITH ALL THIS IN MIND HAVE GONE WITH A 30% POP FOR SCT SHOWERS/ISOLATED THUNDERSTORMS FOR THE LATER AFTERNOON THROUGH MIDDLE EVENING HOURS. IF THE HIRES RUNS ARE CORRECT...THEN THE GREATEST THREAT FOR AN AFTERNOON SHOWER WOULD EXIST WITHIN ABOUT 30 MILES EITHER SIDE OF I-75...HOWEVER...HAVE GONE A BIT MORE BROAD THAN THAT WITH THE FORECAST FOR NOW...AND WILL ALLOW THE DAY SHIFT TO EVALUATE THE PATTERN EVOLUTION...AND ADD A BIT MORE TEMPORAL AND/OR SPATIAL DETAIL. THE CONVECTION IS NOT GOING TO BE VERY ROBUST...AND CERTAINLY NOT EXPECTING ANY STRONG STORMS AT THIS TIME...HOWEVER A BRIEF DOWNPOUR...AND A FEW LIGHTNING STRIKES SHOULD BE PLANNED FOR IF OUTDOORS LATER TODAY. TONIGHT... WIDELY SCATTERED CONVECTIVE CELLS WILL LINGER INTO THE MIDDLE EVENING HOURS...MAINLY TO THE NORTH OF THE I-4 CORRIDOR...AND THEN BEGIN TO DISSIPATE WITH THE LOSS OF DIURNAL HEATING AND RESULTING LOSS OF SURFACE FOCUS. WILL END ALL SHOWERS BY 03-04Z...WITH A DRY OVERNIGHT PERIOD THEREAFTER. FOCUS INTO THE LATER OVERNIGHT HOURS WILL SHIFT TO THE POTENTIAL FOR AREAS OF DENSE FOG DEVELOPMENT. A MOIST BOUNDARY LAYER WILL STILL BE IN PLACE...AND AS WE START TO SEE THE UPPER RIDGE BUILD...AND INCREASED LARGE SCALE SUBSIDENCE...THE SETUP FOR FOG IS FAIRLY GOOD. IN FACT...THE LATEST SREF PROBABILITIES OF VISIBILITY LESS THAN 1 MILE DURING THE LATE NIGHT HOURS TONIGHT IS GREATER THAN 80% ACROSS MUCH OF THE REGION. IT HAS BEEN MY EXPERIENCE TO BEGIN TAKING THE SREF FOG POTENTIAL SERIOUSLY WHEN PROBABILITIES BEGIN TO EXCEED 70% OR SO. HAVE ADDED AREAS OF FOG INTO THE GRIDS...AND AGAIN WILL LET THE DAY SHIFT REEVALUATE BEFORE ADDING DENSE FOG WORDING TO THE FORECAST. FOR NOW...JUST BE AWARE THAT SOME LOCATIONS MAY HAVE A MORE DIFFICULT MONDAY MORNING COMMUTE RESULTING FROM VISIBILITY REDUCTIONS. LOW TEMPERATURES EARLY MONDAY MORNING WILL RANGE FROM THE UPPER 50S OVER LEVY COUNTY...TO THE LOWER/MIDDLE 60S ELSEWHERE. MONDAY... UPPER RIDGE WILL TAKE FIRM CONTROL OVER OUR WEATHER DURING THE DAY. WILL BE EXPECTING A FAIR AMOUNT OF SUN...AFTER ANY MORNING FOG BURNS OFF (WHICH MAY TAKE SEVERAL HOURS). FORECASTING ABOVE AVERAGE TEMPERATURES ACROSS THE REGION AS BOUNDARY LAYER SHOULD BE ABLE TO EASILY MIX OUT TO THE UPPER 70S ACROSS THE FAR NORTH (LEVY/CITRUS COUNTIES)...AND LOWER TO MIDDLE 80S FOR MOST OTHER AREAS. THE STRONG HEATING FORCES ANOTHER SEA-BREEZE TO DEVELOP...AND THIS WILL LIKELY KEEP TEMPERATURES DOWN A BIT (MID/UPPER 70S) ALONG THE IMMEDIATE COAST...AS THE FLOW DEVELOPS OFF THE COOLER SHELF WATERS. HOWEVER...IT WILL NOT TAKE MUCH DISTANCE INLAND TO FIND THE LOWER 80S AGAIN. THE POTENTIAL FOR A BRIEF AFTERNOON SHOWER ALONG THE SEA-BREEZE IS NOT ZERO...HOWEVER WITH THE RIDGE BUILDING OVERHEAD...CONDITIONS ARE NOT AS FAVORABLE AS WE MIGHT SEE THIS AFTERNOON...AND GIVEN THE TIME OF YEAR...IF THINGS DO NOT LINE UP JUST RIGHT...THEN CONVECTION IS REALLY NOT THAT LIKELY. FOR NOW WILL KEEP THE FORECAST GENERALLY DRY MONDAY AFTERNOON. CAN TAKE ANOTHER LOOK AT THIS TONIGHT. && .LONG TERM (TUESDAY THROUGH NEXT SATURDAY)... THROUGH WED; THE AREA WILL BE DOMINATED BY DEEP LAYER RIDGING THAT GRADUALLY SLIDES EAST. INITIALLY THE PATTERN ALOFT BEGINS WITH A LONG WAVE TROUGH FROM CENTRAL CANADA TO THE GREAT BASIN...RIDGING CENTERED OVER THE YUCATAN THAT REACHED ACROSS THE UPPER GREAT LAKES...AND ANOTHER TROUGH FROM QUEBEC SOUTH OVER NEW ENGLAND AND THE CANADIAN MARITIMES TO ATLANTIC WATERS. SURFACE HIGH PRESSURE CENTERED IN THE OHIO VALLEY...AND SPRAWLING DOWN ACROSS THE GULF REGION SHIFTS OUT OVER THE OPEN ATLANTIC WHILE RIDGING BACK ACROSS FL TO THE GULF. THE UPPER RIDGE KEEPS THE ATMOSPHERE STABLE WARM AND GENERALLY DRY. THE TRACK OF THE SURFACE HIGH WILL VEER WINDS FROM NORTHEAST AND EAST TO SOUTHEAST AND SOUTHERLY. THE SOUTHERLY WINDS WILL BRING IN SOME WARM AND MORE HUMID AIR WHICH COULD RESULT IN SEA FOG AS IT MOVES ACROSS THE COOLER GULF WATERS. THU-FRI; THE WESTERN LONG WAVE TROUGH...WITH AN ACCOMPANYING COLD FRONT...BY NOW STRETCHES FROM THE FOUR CORNERS REGION TO THE UPPER GREAT LAKES. THE TROUGH THEN BEGINS TO SHEAR OUT WITH THE EASTERN PORTION DE-AMPLIFYING AS IT SHIFTS OFF THE NORTHEAST U.S. COAST WHILE THE WESTERN END MEANDERS NEAR NORTHERN BAJA CALIFORNIA. THE GULF UPPER RIDGE FLATTENS AND HANGS ON FROM THE YUCATAN ACROSS CUBA TO THE ATLANTIC EAST OF THE BAHAMAS. AS A RESULT NEARLY ZONAL FLOW SETS UP ACROSS THE SOUTHEAST CONUS AND GULF REGION...WITH THE FRONT GETTING STRUNG OUT FROM WEST TO EAST ON OR NEAR THE GULF COAST. HIGH PRESSURE BUILDS IN NORTH OF THE FRONT AND TRACKS EAST...WITH NORTH THEN NORTHEAST WINDS EVENTUALLY BRIDGING THE FRONT AND FILLING IN ACROSS THE AREA. INCREASING MOISTURE ALONG WITH THE FRONT APPROACHING FROM THE NORTH WILL SUPPORT SOME SLIGHT CHANCE SHOWERS AND THUNDERSTORM...INITIALLY ACROSS THE NORTH BUT THAT SPREAD SOUTHWARD WITH TIME. TEMPERATURES THU RUN ABOVE NORMAL BUT COOL ON FRI...TO NEAR NORMAL CENTRAL AND SOUTH BUT NEAR TO A BIT BELOW NORMAL IN THE NORTH WHERE THERE WILL BE MORE RAINFALL AND CLOUDS. SAT; THE BAJA TROUGH BEGINS WORKING EAST...ALONG THE SOUTHWEST CONUS OR NORTHWEST MEXICO BORDER REGIONS...WITH FLOW ALOFT STARTING TO BACK TO WEST-SOUTHWEST. THE FRONT RESIDES ALONG THE GULF COAST IN THE ECMWF SOLUTION WITH SOMEWHAT DRIER CONDITIONS IN FL OR OVER THE NORTHERN GULF WATERS AND NORTH FL WITH THE GFS SOLUTION...KEEPING SLIGHTLY MORE RAINFALL OVER OR NEAR THE AREA. IN EITHER CASE THERE WILL BE SLIGHT CHANCE TO LOW END CHANCE SHOWERS OR STORMS. TEMPERATURES CONTINUE NEAR NORMAL CENTRAL AND SOUTH AND JUST UNDER IN THE NORTH. && .AVIATION... SO FAR...THE CONDITIONS HAVE NOT BE AS PESSIMISTIC AS THE STATISTICAL GUIDANCE PREDICTED AT MOST TERMINALS. WILL CONTINUE THIS TREND FOR THE REMAINDER OF THE OVERNIGHT. ALTHOUGH A FEW PERIODS OF IFR CIGS ARE CERTAINLY POSSIBLE...THE MAJORITY OF THE TIME SHOULD BE MVFR AND WILL CHOOSE TO STAY IN THE RANGE OVER THE NEXT SEVERAL HOURS. PERIODS OF MVFR CIGS SHOULD SLOWLY IMPROVE AFTER SUNRISE AND BRING ALL TERMINALS BACK TO VFR FOR THE MIDDAY/AFTERNOON/EVENING HOURS. THERE IS THE POTENTIAL FOR WIDELY SCT SHOWERS AND ISOLATED STORMS AFTER 19-20Z...LINGERING THROUGH 00-02Z. ANY SHOWERS WILL BE BRIEF AND HAVE USED VCSH TO HIGHLIGHT THIS POTENTIAL. ANY SHOWERS DISSIPATED BY LATE EVENING AND FOCUS SHIFTS TO FOG POTENTIAL AFTER MIDNIGHT. BOTH STATISTICAL AND ENSEMBLE GUIDANCE ARE BEGINNING TO SUGGEST THE POTENTIAL FOR AREAS OF IFR FOG AFTER 06Z. && .MARINE... HIGH PRESSURE TO OUR NORTH WILL WEAKEN TODAY ALLOWING THE GRADIENT TO RELAX AND WIND FIELDS TO WEAKEN. THE GRADIENT WILL RELAX ENOUGH BY THIS AFTERNOON TO ALLOW SEA BREEZE FORMATION WITH WINDS BECOMING LIGHT ONSHORE THROUGH THE EARLY EVENING. THE GENERALLY SYNOPTIC EASTERLY FLOW WILL SHIFT SOUTHEAST ON TUESDAY AND THEN SOUTH BY WEDNESDAY. EXPECT NEARSHORE WINDS TO BECOME ONSHORE EACH AFTERNOON AND EARLY EVENING. THERE IS THE POTENTIAL WITH THE MOIST SOUTHERLY FLOW FOR AREAS OF SEA FOG TO REDUCE VISIBILITY BY LATER TUESDAY OR WEDNESDAY...AND THIS POTENTIAL WILL NEED TO BE MONITORED CLOSELY. A COLD FRONT IS SCHEDULED TO ARRIVE LATER THURSDAY OR THURSDAY NIGHT WHICH WOULD END THE THREAT FOR SEA FOG FOR THE END OF THE WEEK...AND SHIFT WINDS BACK FROM THE NORTH AND NORTHEAST. && .FIRE WEATHER... NO SIGNIFICANT FIRE WEATHER CONCERNS OUTSIDE OF FOG POTENTIAL ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS AS RELATIVE HUMIDITY REMAINS WELL ABOVE CRITICAL LEVELS AND ERC VALUES ARE LOW ACROSS THE REGION. TEMPERATURES WILL HOWEVER BE ABOVE AVERAGE FOR MUCH OF THE EARLY AND MIDDLE PORTION OF THE WEEK. FOG POTENTIAL... AREAS OF FOG ARE EXPECTED TO DEVELOP TONIGHT INTO EARLY MONDAY MORNING ACROSS MUCH OF WEST-CENTRAL AND SOUTHWEST FLORIDA. THE FOG HAS THE POTENTIAL TO BECOME LOCALLY DENSE AT TIME. AREAS OF FOG ARE ALSO FORECAST FOR LATER MONDAY NIGHT INTO TUESDAY MORNING. && .PRELIMINARY POINT TEMPS/POPS... TPA 78 65 79 64 / 30 10 10 0 FMY 82 65 83 64 / 30 10 10 0 GIF 80 65 81 63 / 30 20 10 10 SRQ 78 63 79 62 / 20 10 10 0 BKV 80 60 80 59 / 30 20 10 0 SPG 78 65 78 65 / 20 10 10 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
455 AM EST SUN MAR 1 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY. HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... PRE-DAWN...HIGH PRES WEDGED INTO GEORGIA AND THE CAROLINAS EARLY THIS MORNING WITH A COASTAL TROUGH ALONG THE WEST WALL OF THE GULF STREAM. AREAS OF LIGHT RAINS HAVE BEEN QUITE TRANSIENT OVERNIGHT AND MAINLY NORTH OF I-16 BUT A STEADY STREAM OF ISENTROPIC ASCENT SHOULD ENSURE PERIODIC WET WEATHER FOR MUCH OF THE FORECAST AREA AS ISENTROPIC ASCENT IS MAINTAINED ACROSS A DEEP THERMAL SURFACE. AT THE GROUND LEVEL...SURFACE PRESSURES WERE FALLING ACROSS THE AREA...A SIGN THAT THE STRENGTH OF THE WEDGE HAS PEAKED. CLOUDS WERE LOWERING AS WARM AIR ADVECTION INCREASES ATOP THE BOUNDARY LAYER. TEMPS WERE CHILLY ONCE AGAIN WITH READINGS IN THE UPPER 30S INLAND TO LOWER 40S ALONG THE COAST. WHILE CLOUDY/COOL AND OCCASIONALLY DAMP WEATHER WILL BE THE MAIN WEATHER FEATURES TO RING IN THE MONTH OF MARCH...THE MAIN FORECAST QUEST TODAY WILL BE FORECASTING THE DIURNAL TEMP CURVE ALONG WITH HIGH TEMPS IN A STUBBORN WEDGE PATTERN WITH THE COASTAL TROUGH UNLIKELY TO PUNCTUATE THE VERY CHILLY NEAR SHORE SHELF WATERS. EVEN THOUGH WE WILL KEEP THE WARM FRONT OFF THE COAST...QUITE A FEW OF THE MODELS RESPECT THE 14C BOUNDARY LAYER TEMPS ADVECTING OVER THE COASTAL EROSION OF THE SHALLOW COLDER AIR MASS AND SUGGEST LATE AFTERNOON TEMPS ALONG AND EAST OF U.S. 17 WILL EVENTUALLY REBOUND LATE AS SURFACE WINDS BECOME LIGHT AND PERHAPS VARIABLE. THE 13 KM RAP AND ECMWF BOTH SHOW A VERY NARROW SLOT OF NEAR 60 DEGREE SURFACE TEMPS JUST INLAND FROM THE BEACHES AROUND NORTH CHARLESTON AND WHILE NOT FAR INLAND COULD BE LOCKED IN TO LOWER TO MID 40 DEGREE AIR AT THE SURFACE. A THERMAL GRADIENT THAT SIGNIFICANT IS NOT TOTALLY OUT OF THE QUESTION BUT WE OPTED JUST TO TIGHTEN THE TEMP GRADIENT THIS AFTERNOON JUST A BIT WITH PLENTY OF MESOSCALE UNCERTAINTIES INCLUDING RAINFALL COVERAGE. RAINFALL AMOUNTS SHOULD GENERALLY BE LIGHT AND LESS THAN A QUARTER INCH FOR THE MOST PART. WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING INTO TONIGHT WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A CONCERN FOR DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING ADVECTS NE INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW CONFIDENCE AT THIS JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY FOG TO AREAS OF FOG AS A TREND. THERE WILL PROBABLY BE PATCHY DRIZZLE AROUND THE REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES AND THE SYNOPTIC OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT READINGS MANY BE STEADY OR RISING LATE. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO LOW/MID 50S IN SOUTHEAST GEORGIA. TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY AFTERNOON/EVENING. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... BOTH AIRFIELDS HAD MVFR CEILINGS AT 09Z...WHICH WILL GRADUALLY LOWER INTO THE IFR RANGE IN A FEW HOURS...THEN PERSIST THROUGH THE REMAINDER OF THE VALID CYCLE. THIS IS THE RESULT OF ABUNDANT MOISTURE TRAPPED BENEATH THE WEDGE INVERSION...AIDED BY ISENTROPIC LIFT AT VARIOUS LEVELS. PERIODIC LIGHT RAINS OR EVEN DRIZZLE AT TIMES LIKELY TODAY WITH FOG POTENTIALLY AN ISSUE TONIGHT AS THE LOW CLOUDS BUILD DOWN WITH STRONG WARM AIR ADVECTION ABOVE THE COOLER SURFACE TEMPS WITH A DRYING TREND IN THE 3-5 KFT LAYER. THEE 00Z-06Z MONDAY PORTION OF THE TAFS...CONFIDENCE IS VERY GOOD THAT LIFR CIGS AND PERHAPS IFR VSBYS WILL PREVAIL GIVEN LATEST MODEL DATA. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT SHIFTS THROUGH THE AREA. && .MARINE... HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE THROUGH THE MORNING WITH A MUCH LIGHTER GRADIENT BY LATER TODAY AND TONIGHT. IT WILL DIFFICULT TO TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT GIVEN THE STABLE CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW TO N LATER TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT OVER OUTER GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN ADVISORY LEVELS UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS COULD LOWER TO 1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE LAND/SEA INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS LIKELY WILL BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS. MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT. WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350- 352-354. SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...DPB LONG TERM...DPB AVIATION... MARINE...DPB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
257 AM CST SUN MAR 1 2015 .SYNOPSIS... ISSUED AT 149 AM CST SUN MAR 1 2015 VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE FOG. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 149 AM CST SUN MAR 1 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL. A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12 HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE CWA BY 18Z. AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE SHOULD END UP WITH SUN FOR THE SUNSET. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 149 AM CST SUN MAR 1 2015 THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING. SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD. IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE SHIFTS TODAY OR TONIGHT. SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO RUNOFF ISSUES ARE EXPECTED. AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY AND SATURDAY. ERVIN && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1142 PM CST SAT FEB 28 2015 CONDITIONS EXPECTED TO DETERIORATE TO MVFR AND IFR OVERNIGHT INTO SUNDAY AM IN LOW CLOUDS AND/OR FOG. PATCHY LIFR/VLIFR CONDITIONS IN FOG WILL BE POSSIBLE. LIGHT SNOW LOOKS TO STAY JUST SOUTH OF BRL TAF SITE THROUGH SUNDAY AM AND THUS LEFT OUT MENTION THOUGH A FEW FLURRIES ALSO POSSIBLE AT TIMES AT ALL SITES. ANTICIPATE CIGS LIFTING TO HIGH MVFR AND EVENTUALLY VFR SUNDAY PM WITH DEVELOPING SOUTHWEST WINDS AROUND 10 KTS. WINDS WILL SHIFT TO WEST/NORTHWEST LATE PM INTO EARLY EVE WITH VFR CONDITIONS. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...ERVIN AVIATION...05
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
350 AM CST SUN MAR 1 2015 ...UPDATED SHORT TERM SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CST SUN MAR 1 2015 WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT DEPRESSIONS HAVE BEEN THE SMALLEST. SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT. WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 214 PM CST SAT FEB 28 2015 A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO MONDAY NIGHT REACHING TO THE MID TO UPPER 30S. MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON. THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 109 AM CST SUN MAR 1 2015 IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS, AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI RESOLUTIONS AND RAPID REFRESH MODELS INIDCATE A NARROW BAND OF WHAT WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID MORNING. BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE MORE OF AN ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN MVFR STRATUS AT HYS. && .PRELIMINARY POINT TEMPS/POPS... DDC 31 18 38 35 / 10 10 10 10 GCK 31 18 40 34 / 20 10 10 10 EHA 33 20 45 37 / 20 20 10 10 LBL 34 23 43 37 / 20 10 10 10 HYS 36 17 37 33 / 10 10 20 20 P28 32 20 37 34 / 20 10 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...HOVORKA_42 AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
257 AM CST Sun Mar 1 2015 .SHORT TERM...(Today and Tonight) Issued at 257 AM CST SUN MAR 1 2015 Expansive upper trough axis continues to rotate off the CA coast while weaker embedded areas of vorticity were lifting north and east towards Colorado and Kansas. A stronger shortwave trough was observed shifting southeast towards the northern plains later this morning. Lows were starting out in the teens and lower 20s with scattered light snow or flurries across northeast Kansas. Main highlight of the forecast is expected snowfall from sunrise through noon today. As the upper trough dives southeast, mid level forcing is enhanced within the embedded vorticity maxima tracking east over the state. Timing of this feature and area of weak frontogenesis will place the snow band near the Interstate 70 corridor based on latest runs of the RAP and NAM or just south near the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions. Duration of light snow is quick as well with lift diminishing eastward by mid afternoon today. Main changes for the forecast package were to remove precip chances for far north central Kansas as dry air aloft increases after sunrise. Also adjusted highest chances for snowfall in the above mentioned areas where an additional one half to one inch of snow is expected. Will maintain the advisory ongoing until noon and have the following shift remove counties as the snowfall exits. With the snowfall exiting quicker and the possibility of higher cloud bases, increased highs today a few degrees in the lower to possibly middle 30s. Weak high pressure shifts southeast this evening as skies become partly to mostly cloudy. Calm winds and snow covered ground hold lows in the upper teens to lower 20s. .LONG TERM...(Monday through Saturday) Issued at 257 AM CST SUN MAR 1 2015 For Monday models prog the mid level shortwave ridge to be over the area with low level moisture remaining to the south of the forecast. So with no real forcing expected to affect the area, have a dry forecast through the day. With some cloud cover and the surface ridge possibly influencing eastern KS still, have highs only reaching the mid and upper 30s. Monday night and Tuesday appear to be the next opportunity for precip as low level return flow advects moisture north while a shortwave kicks out from the base of the mid level trough over the southwest. However chances appear to remain limited. The model consensus shows the stronger Q vector convergence and PV anomaly passing just north of the forecast area while a dry slot moves into eastern KS by Tuesday morning. With the deeper moisture over far eastern KS, have kept the higher POPs across the east during the early morning hours Tuesday as the shortwave passes by. Prior to this there could be some drizzle develop and spread northeast through the area in response to the stronger low level moisture return. Depending on temps, there could be a brief period of light freezing drizzle. However I expect this to be short lived mainly in the evening as warm air advection should cause temps to rise through the night. Therefore any accumulations should be very minor. Another arctic ridge of high pressure is set to move through the forecast area Tuesday with the GFS trending a little faster with the frontal passage. However with the dry slot in place as the front moves through and upper level forcing likely to the northeast of the forecast area, the front may move through mostly dry through the early afternoon. The forecast anticipates falling temps through the afternoon as cold air moves in behind the front. But for the most part think that any precip on Tuesday is likely to be out ahead of the front and in the form of rain. There are still weak indications of some convective instability Tuesday morning. Because of this have kept a mention for thunder across east central KS. Lows Monday night are forecast to occur early in the evening while highs Tuesday are likely to be measured late in the morning. Tuesday night may be the last chance for precip through the rest of the week. There remains some indication for some mid level frontogenesis along with enough moisture for mid level saturation. The NAM is most bullish with this idea developing several hundredths of precip. While less impressive, the ECMWF also spits out some very light precip. Because of this have continued with a slight chance for snow Tuesday night. However would not anticipate the snow amounting to very much if at all. The upper level trough axis is progged to finally move east of the forecast area Wednesday night. But with dry air moving in with the arctic airmass on Tuesday, precip chances Wednesday and Wednesday night look to be less than 20 percent due to to much dry air. Wednesday is shaping up to be another cold day with lows in the teens and highs in the 20s. Thursday through Saturday continues to look dry with moderating temps as models keep a dry northwest flow over the central plains. By Friday, highs are expected to be in the 50s. This could be a little conservative with the GFS and ECMWF showing 925 MB temps warming to between +5 and +10C. For now stayed with the model consensus and have highs in the lower 50s. && .AVIATION...(For the 06Z TAFs through 06Z Sunday Night) Issued at 1125 PM CST SAT FEB 28 2015 WILL SCATTER OUT THE 2 KFT DECK AT THIS TIME AS PREVAILING CIGS HEIGHT IS GENERALLY BETWEEN 3-4 KFT. WILL KEEP PREVAILING SNOW FOR LIGHT BAND MOVING OVER TAF SITES BUT HAVE IMPROVED VSBY TO 4SM. STILL HOLD LOWER CLOUDS TILL AROUND THE NOON HOUR BEFORE STARTING TO LIFT AND CLEAR OUT LATER IN THE PERIOD. && .TOP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY until Noon CST today FOR KSZ021>024-026- 034>040-054>056-058-059. && $$ SHORT TERM...Bowen LONG TERM...Wolters AVIATION...67
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
112 AM CST SUN MAR 1 2015 ...UPDATED AVIATION SECTION... .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 341 PM CST SAT FEB 28 2015 AS WE REMAIN IN THIS BROAD, CYCLONICALLY-CURVED FLOW PATTERN, WE WILL CONTINUE TO SEE THE TREND OF MINOR SHORTWAVE PERTURBATIONS ROTATING ACROSS SOUTHWESTERN KANSAS...PROVIDING US WITH CHANCES FOR LIGHT PRECIPITATION AS WE SEE SUBTLE DEFORMATION/CONVERGENCE IN THE LOWER-MID TROPOSPHERE ALONG THE BAROCLINIC ZONE. THE NEXT IN THE SERIES WILL BE TONIGHT AFTER THE BREAK WE HAD THIS AFTERNOON. POPS WILL BE INCREASED BACK UP IN TO THE LIKELY CATEGORY WITH A CONTINUATION OF THE WINTER WEATHER ADVISORY. THE VERY LATEST 18Z RUNS OF THE NAM12 AND THE HRRR/RAP HAVE THROWN A LITTLE WRINKLE IN THE NEAR TERM FORECAST. THE NAM12 SUGGESTS THE NEXT LIGHT PRECIPITATION EVENT WILL START ABOUT 6 HOURS SOONER THAN PREVIOUSLY THOUGHT (WHICH IS SIGNIFICANT AT THIS CLOSE OF A TIME RANGE) WHEREAS THE RAP AND HRRR REALLY SHOW NOTHING MUCH AT ALL. IT REALLY IS A FINE LINE BETWEEN NO PRECIP AT ALL AND LIGHT ACCUMULATING PRECIP IN THIS FLOW REGIME, AS MUCH DOWNSLOPE AS THERE IS (YET MOIST). THE SHORT TERM MODELS SHOW A WARMING OF THE 850-750MB LAYER TO THE POINT THAT A SLIGHT WARM NOSE ABOVE 0C WILL DEVELOP. THIS WILL FAVOR SLEET AS A PRECIPITATION TYPE LATE TONIGHT, PARTICULARLY SOUTH OF THE ARKANSAS RIVER. IT SHOULD BE NOTED THAT, AGAIN, ANY PRECIPITATION TONIGHT WOULD BE QUITE LIGHT AND MAY NOT EVEN HAPPEN AT ALL. THE INCOMING SWING SHIFT WILL NEED TO WATCH TRENDS TO SEE OF THE WINTER WX ADVISORY IS STILL NEED THROUGH THE OVERNIGHT HOURS AND IN TO THE MORNING SUNDAY. TEMPERATURES OVERNIGHT WILL REMAIN QUASI-STEADY AROUND 20 DEGREES WITH THE CONTINUED SOUTH WINDS AND CLOUDS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 214 PM CST SAT FEB 28 2015 A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO MONDAY NIGHT REACHING TO THE MID TO UPPER 30S. MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON. THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 109 AM CST SUN MAR 1 2015 IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS, AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI RESOLUTIONS AND RAPID REFRESH MODELS INIDCATE A NARROW BAND OF WHAT WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID MORNING. BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE MORE OF AN ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN MVFR STRATUS AT HYS. && .PRELIMINARY POINT TEMPS/POPS... DDC 31 20 38 35 / 60 20 20 20 GCK 31 19 40 34 / 30 20 20 10 EHA 33 21 45 38 / 20 30 20 10 LBL 34 22 43 37 / 30 20 10 10 HYS 35 21 39 33 / 30 20 20 20 P28 32 22 39 35 / 60 10 30 30 && .DDC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR KSZ046-064>066- 076>081-086>090. && $$ SHORT TERM...UMSCHEID LONG TERM...HOVORKA_42 AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS JACKSON KY
343 AM EST SUN MAR 1 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 345 AM EST SUN MAR 1 2015 CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC. AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY THIS SUNDAY MORNING. HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 345 AM EST SUN MAR 1 2015 MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION LATE SATURDAY NIGHT...EARLY SUNDAY MORNING. NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST +5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE ONSET OF PRECIPITATION. OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST LOCATIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1234 AM EST SUN MAR 1 2015 EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA. EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT. WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SHALLENBERGER LONG TERM...AR AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
212 AM EST SUN MAR 1 2015 .MESOSCALE DISCUSSION... ISSUED AT 212 AM EST SUN MAR 1 2015 THE MAIN SURGE OF MOISTURE CONTINUES TO STAY TO THE NORTH AS OF 07Z WITH ONLY LIGHT RETURNS...LIKELY VIRGA...OVER THE BLUEGRASS REGION. MESONETS IN CENTRAL KY WELL NORTH OF I-64 ARE THE ONLY LOCATIONS INDICATING MEASURABLE PRECIP. THOUGH AIR TEMPS ACROSS THE AREA ARE REACHING FREEZING IN THE BLUEGRASS AREAS BUT ALSO...AS CONCERNING AS THIS IS...IN SOME OF THE DEEPER VALLEYS IN THE FAR EAST OF EASTERN KENTUCKY...SUCH AS THE PAINTSVILLE MESONET WHERE A CHILLY 30 DEGREES IS DISPLAYED. AS WELL...MOST DEW POINT DEPRESSIONS ARE STILL A GOOD 10 DEGREES PLUS IN MANY AREAS. IN ADDITION...HI RES MODELS SUCH AS THE HRRR SHOW PRECIP HOLDING OFF UNTIL 10Z AND AFTER. THE GENERAL CONSENSUS HERE IS THAT THE BULK OF THE MOISTURE WILL STAY NORTH WHILE WHAT RESIDUAL MOISTURE ADVECTING IN FROM THE SOUTHWEST WILL NOT BE ABLE TO SATURATING THE LAYER FOR PRECIP TO REACH THE SURFACE. ONCE THIS DOES OCCUR...THE CURRENT ROAD TEMPS...NOW IN THE MID TO UPPER 30S...WOULD SUGGEST A SUBSTANTIAL COOL DOWN NEEDED FOR ICE ON ROADWAYS TO DEVELOP. THESE TEMPS SHOULD HOLD OFF UNTIL AFTER DAWN WHEN TEMPS WARM AGAIN. DUE TO THE THREAT AND THE FACT THAT 0.01 OF FZRA COULD OCCUR...THIS STILL NEEDS TO BE A SLIGHT REMINDER SO HAVE REISSUED THE SPS THROUGH DAWN. && .UPDATE... ISSUED AT 958 PM EST SAT FEB 28 2015 MADE SOME MORE TWEAKS TO TEMPERATURES. SOME VALLEY LOCATIONS ARE ALREADY DOWN TO 31 DEGREES WITH SEVERAL MORE RIGHT ON THEIR HEELS. DO NOT EXPECT TEMPERATURES TO GET TOO MUCH COLDER AS CLOUDS ARE SPREAD INTO THE REGION AND SHOULD HALT THEIR FALL. HOWEVER...THE QUESTION CONTINUES...WILL THESE TEMPERATURES COME BACK UP PRIOR TO PRECIPITATION ONSET LATE TONIGHT. AS IT APPEARS NOW...THIS MAY BE A STRUGGLE AND THUS...THE FREEZING RAIN THREAT CONTINUES. HRRR HAS BEGUN TO FLUCTUATE ON PRECIPITATION DEVELOPING AROUND DAWN...BUT THE LATEST RUN HAS IT BACK IN THERE. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORY FOR NOW AS STILL NOT CERTAIN HOW MUCH FREEZING RAIN WILL ACTUALLY OCCUR AND WHETHER IT HAS ANY IMPACT AS GROUND TEMPERATURES RECOVERED FAIRLY WELL WITH THE SUNSHINE EARLIER TODAY. OUTSIDE OF SOME TWEAKS TO TEMPERATURES...WILL MAINTAIN THE FORECAST AS IS. UPDATE ISSUED AT 715 PM EST SAT FEB 28 2015 OPTED FOR A SPECIAL WEATHER STATEMENT FOR THE FREEZING RAIN/SLEET/SNOW POTENTIAL LATE TONIGHT. LAST SEVERAL RUNS OF THE HRRR HAVE SHOWN PRETTY GOOD PRECIPITATION DEVELOPMENT AFTER 09Z TONIGHT. WITH THE UNCERTAINTY ON WHETHER TEMPERATURES CAN STAY ABOVE FREEZING...IT CERTAINLY LOOKS LIKE A SETUP FOR SOME FREEZING RAIN. WITH THE DRY AIR IN PLACE...SOME SLEET MAY BE POSSIBLE EARLY ON AS WELL. ANY SNOW POTENTIAL WILL LIKELY STAY TO THE NORTH AS THE WARM NOSE POKES ACROSS THE AREA. TWEAKED TEMPERATURES AND DEWPOINTS THROUGH THE NIGHT AND RE RAN THE WEATHER TO MATCH THE EXPECTED TRANSITION ZONES THROUGH DAYBREAK. WE SHOULD SEE A TRANSITION TO RAIN SHORTLY AFTER DAYBREAK AS ANY REMAINING COLD AIR GETS SCOURED OUT IN THE VALLEYS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 350 PM EST SAT FEB 28 2015 WINDS WILL SHIFT TO A MORE SRLY DIRECTION ON THE BACKSIDE OF EXITING HIGH PRESSURE THIS EVENING...CREATING A PSEUDO WARM FRONTAL BOUNDARY ALONG A DEVELOPING LLVL JET. OVERRUNNING PRECIP WILL THEN DEVELOP BY THIS EVENING IN NORTHERN PORTIONS OF CENTRAL KENTUCKY...INTO INDIANA AS WELL AS OHIO. THIS WILL BRING PRECIP INTO EASTERN KENTUCKY BY OR SHORTLY AFTER 06Z TONIGHT. THERE CONTINUES TO BE A FEW CONCERNS WITH THIS SYSTEM...NAMELY A LIGHT ICE AND SNOW POTENTIAL. LATEST FORECAST SOUNDINGS ARE CONTINUING TO SUPPORT A STEADY OR GRADUAL WARMING OF TEMPS THROUGHOUT THE NIGHT AS SOUTHERLY WINDS... CLOUD COVER...AND PRECIP TAKE CONTROL. HOWEVER...GIVEN THE ANTECEDENT COLD CONDITIONS...IT IS LIKELY THAT EVEN AS SURFACE TEMPS SLOWLY RISE...THE PAVEMENT AND GROUND TEMPS WILL TAKE AN HOUR TO 3 HOURS LONGER. TEMPERATURES IN THE LLVLS WILL RISE ABOVE FREEZING BETWEEN 0 AND 6Z...HOWEVER...SURFACE TEMPS WILL LIKELY LAG BEHIND BY A FEW HOURS. THIS WILL CREATE THE SET UP FOR SOME SNOW/IP POTENTIAL JUST AT ONSET /AND CONTINUING IN THE NORTH FOR A BIT LONGER/...THEN A FREEZING RAIN POTENTIAL GIVEN THE LATEST NAM12 AND GFS40 FORECAST SOUNDINGS THROUGH AROUND 12Z...BEFORE SURFACE TEMPS FINALLY WARM ENOUGH ACROSS THE REGION THAT ALL PRECIP FALLS AS RAIN AFTER 12Z TO 15Z. GIVEN THE WARMER SRLY FLOW TOMORROW...TEMPS WILL FINALLY INCREASE TO CLOSER TO SEASONABLE NORMAL VALUES DURING THE AFTERNOON...GENERALLY IN THE 40S. FROM HERE...FORECAST SOUNDINGS SHOW A DEEP LAYER OF MOISTURE CONTINUING THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS SUNDAY NIGHT WITH SOME CONTINUOUS/WIDESPREAD RAINFALL POSSIBLE. RAIN WILL THEN CHANGE BACK OVER TO SNOW AS TEMPS DROP BELOW FREEZING AFTER DARK...BEFORE FINALLY LOSING INTENSITY AND TAPERING OFF MONDAY MORNING AS HIGH PRESSURE MOVES IN OVERHEAD. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 451 PM EST SAT FEB 28 2015 THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE PATTERN TO RULE ACROSS THE CONUS THROUGH NEXT WEEKEND. A POSITIVELY TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST FLOW TO SETTING UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW FOR A STOUT BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND TENNESSEE VALLEYS THROUGH THE MIDDLE OF THE WEEK...WITH MUCH WARMER AND WETTER AIR BEING ADVECTED INTO THE REGION. THIS WILL BE FOLLOWED BY ANOTHER SHARP COOL DOWN...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW BEFORE ENDING THE WORK WEEK COLD AND DRY. DETAILS ON HOW ALL OF THIS EVOLVES CONTINUES TO BE LOWER CONFIDENCE UNTIL WE GET A LITTLE CLOSER TO THE EVENT...SO HAVE STUCK CLOSE TO A BLEND OF THE SOLUTIONS. IN GENERAL...THE MODELS SEEM TO BE COUPLING THE MOISTURE AND BEST FORCING INITIALLY FURTHER TO THE NORTHWEST...RESULTING IN NOT QUITE AS SIGNIFICANT RAINFALL TOTALS ACROSS EASTERN KENTUCKY FROM TUESDAY THROUGH THURSDAY...WITH GENERALLY 2 TO 3 INCHES FORECAST. STILL...THIS WILL BE MORE THAN ENOUGH TO CAUSE FLOODING CONCERNS AND WILL CONTINUE TO HIGHLIGHT THIS THREAT IN AN ONGOING HYDROLOGIC OUTLOOK. PRECIPITATION MAY START OUT AS A WINTRY MIX LATE MONDAY INTO EARLY TUESDAY MORNING...DEPENDING ON HOW QUICKLY IT CAN COOL DOWN AS WINDS VEER AROUND TO THE SOUTHEAST AND THICKER CLOUDS OVERSPREAD THE AREA ONCE AGAIN. A SURFACE WARM FRONT WILL LIFT THROUGH ON TUESDAY...WITH RAINY CONDITIONS MOVING IN. THE COLD FRONT WILL FOLLOW AND VERY GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...PROVIDING THE BULK OF THE HEAVIER RAINFALL. MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. AFTER ENJOYING HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS WILL FALL BACK INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS BOTTOMING OUT NEAR THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL RETURN TO THE 40S FOR SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1234 AM EST SUN MAR 1 2015 EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA. EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT. WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE...SHALLENBERGER UPDATE...KAS SHORT TERM...JMW LONG TERM...GEOGERIAN AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
1234 AM EST SUN MAR 1 2015 .UPDATE... ISSUED AT 958 PM EST SAT FEB 28 2015 MADE SOME MORE TWEAKS TO TEMPERATURES. SOME VALLEY LOCATIONS ARE ALREADY DOWN TO 31 DEGREES WITH SEVERAL MORE RIGHT ON THEIR HEELS. DO NOT EXPECT TEMPERATURES TO GET TOO MUCH COLDER AS CLOUDS ARE SPREAD INTO THE REGION AND SHOULD HALT THEIR FALL. HOWEVER...THE QUESTION CONTINUES...WILL THESE TEMPERATURES COME BACK UP PRIOR TO PRECIPITATION ONSET LATE TONIGHT. AS IT APPEARS NOW...THIS MAY BE A STRUGGLE AND THUS...THE FREEZING RAIN THREAT CONTINUES. HRRR HAS BEGUN TO FLUCTUATE ON PRECIPITATION DEVELOPING AROUND DAWN...BUT THE LATEST RUN HAS IT BACK IN THERE. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORY FOR NOW AS STILL NOT CERTAIN HOW MUCH FREEZING RAIN WILL ACTUALLY OCCUR AND WHETHER IT HAS ANY IMPACT AS GROUND TEMPERATURES RECOVERED FAIRLY WELL WITH THE SUNSHINE EARLIER TODAY. OUTSIDE OF SOME TWEAKS TO TEMPERATURES...WILL MAINTAIN THE FORECAST AS IS. UPDATE ISSUED AT 715 PM EST SAT FEB 28 2015 OPTED FOR A SPECIAL WEATHER STATEMENT FOR THE FREEZING RAIN/SLEET/SNOW POTENTIAL LATE TONIGHT. LAST SEVERAL RUNS OF THE HRRR HAVE SHOWN PRETTY GOOD PRECIPITATION DEVELOPMENT AFTER 09Z TONIGHT. WITH THE UNCERTAINTY ON WHETHER TEMPERATURES CAN STAY ABOVE FREEZING...IT CERTAINLY LOOKS LIKE A SETUP FOR SOME FREEZING RAIN. WITH THE DRY AIR IN PLACE...SOME SLEET MAY BE POSSIBLE EARLY ON AS WELL. ANY SNOW POTENTIAL WILL LIKELY STAY TO THE NORTH AS THE WARM NOSE POKES ACROSS THE AREA. TWEAKED TEMPERATURES AND DEWPOINTS THROUGH THE NIGHT AND RE RAN THE WEATHER TO MATCH THE EXPECTED TRANSITION ZONES THROUGH DAYBREAK. WE SHOULD SEE A TRANSITION TO RAIN SHORTLY AFTER DAYBREAK AS ANY REMAINING COLD AIR GETS SCOURED OUT IN THE VALLEYS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 350 PM EST SAT FEB 28 2015 WINDS WILL SHIFT TO A MORE SRLY DIRECTION ON THE BACKSIDE OF EXITING HIGH PRESSURE THIS EVENING...CREATING A PSEUDO WARM FRONTAL BOUNDARY ALONG A DEVELOPING LLVL JET. OVERRUNNING PRECIP WILL THEN DEVELOP BY THIS EVENING IN NORTHERN PORTIONS OF CENTRAL KENTUCKY...INTO INDIANA AS WELL AS OHIO. THIS WILL BRING PRECIP INTO EASTERN KENTUCKY BY OR SHORTLY AFTER 06Z TONIGHT. THERE CONTINUES TO BE A FEW CONCERNS WITH THIS SYSTEM...NAMELY A LIGHT ICE AND SNOW POTENTIAL. LATEST FORECAST SOUNDINGS ARE CONTINUING TO SUPPORT A STEADY OR GRADUAL WARMING OF TEMPS THROUGHOUT THE NIGHT AS SOUTHERLY WINDS... CLOUD COVER...AND PRECIP TAKE CONTROL. HOWEVER...GIVEN THE ANTECEDENT COLD CONDITIONS...IT IS LIKELY THAT EVEN AS SURFACE TEMPS SLOWLY RISE...THE PAVEMENT AND GROUND TEMPS WILL TAKE AN HOUR TO 3 HOURS LONGER. TEMPERATURES IN THE LLVLS WILL RISE ABOVE FREEZING BETWEEN 0 AND 6Z...HOWEVER...SURFACE TEMPS WILL LIKELY LAG BEHIND BY A FEW HOURS. THIS WILL CREATE THE SET UP FOR SOME SNOW/IP POTENTIAL JUST AT ONSET /AND CONTINUING IN THE NORTH FOR A BIT LONGER/...THEN A FREEZING RAIN POTENTIAL GIVEN THE LATEST NAM12 AND GFS40 FORECAST SOUNDINGS THROUGH AROUND 12Z...BEFORE SURFACE TEMPS FINALLY WARM ENOUGH ACROSS THE REGION THAT ALL PRECIP FALLS AS RAIN AFTER 12Z TO 15Z. GIVEN THE WARMER SRLY FLOW TOMORROW...TEMPS WILL FINALLY INCREASE TO CLOSER TO SEASONABLE NORMAL VALUES DURING THE AFTERNOON...GENERALLY IN THE 40S. FROM HERE...FORECAST SOUNDINGS SHOW A DEEP LAYER OF MOISTURE CONTINUING THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS SUNDAY NIGHT WITH SOME CONTINUOUS/WIDESPREAD RAINFALL POSSIBLE. RAIN WILL THEN CHANGE BACK OVER TO SNOW AS TEMPS DROP BELOW FREEZING AFTER DARK...BEFORE FINALLY LOSING INTENSITY AND TAPERING OFF MONDAY MORNING AS HIGH PRESSURE MOVES IN OVERHEAD. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 451 PM EST SAT FEB 28 2015 THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE PATTERN TO RULE ACROSS THE CONUS THROUGH NEXT WEEKEND. A POSITIVELY TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST FLOW TO SETTING UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW FOR A STOUT BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND TENNESSEE VALLEYS THROUGH THE MIDDLE OF THE WEEK...WITH MUCH WARMER AND WETTER AIR BEING ADVECTED INTO THE REGION. THIS WILL BE FOLLOWED BY ANOTHER SHARP COOL DOWN...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW BEFORE ENDING THE WORK WEEK COLD AND DRY. DETAILS ON HOW ALL OF THIS EVOLVES CONTINUES TO BE LOWER CONFIDENCE UNTIL WE GET A LITTLE CLOSER TO THE EVENT...SO HAVE STUCK CLOSE TO A BLEND OF THE SOLUTIONS. IN GENERAL...THE MODELS SEEM TO BE COUPLING THE MOISTURE AND BEST FORCING INITIALLY FURTHER TO THE NORTHWEST...RESULTING IN NOT QUITE AS SIGNIFICANT RAINFALL TOTALS ACROSS EASTERN KENTUCKY FROM TUESDAY THROUGH THURSDAY...WITH GENERALLY 2 TO 3 INCHES FORECAST. STILL...THIS WILL BE MORE THAN ENOUGH TO CAUSE FLOODING CONCERNS AND WILL CONTINUE TO HIGHLIGHT THIS THREAT IN AN ONGOING HYDROLOGIC OUTLOOK. PRECIPITATION MAY START OUT AS A WINTRY MIX LATE MONDAY INTO EARLY TUESDAY MORNING...DEPENDING ON HOW QUICKLY IT CAN COOL DOWN AS WINDS VEER AROUND TO THE SOUTHEAST AND THICKER CLOUDS OVERSPREAD THE AREA ONCE AGAIN. A SURFACE WARM FRONT WILL LIFT THROUGH ON TUESDAY...WITH RAINY CONDITIONS MOVING IN. THE COLD FRONT WILL FOLLOW AND VERY GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...PROVIDING THE BULK OF THE HEAVIER RAINFALL. MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. AFTER ENJOYING HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS WILL FALL BACK INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS BOTTOMING OUT NEAR THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL RETURN TO THE 40S FOR SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1234 AM EST SUN MAR 1 2015 EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA. EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT. WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JMW LONG TERM...GEOGERIAN AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 AM EST SUN MAR 1 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM EST SUN MAR 1 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS. MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN. MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE DISTURBANCES. TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE 25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL. TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85 THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN THAT AREA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 416 AM EST SUN MAR 1 2015 MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY. MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION. ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE WARMER THAN THE LAST SEVERAL WEEKS. MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND 0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND 2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA. WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE. KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P. FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30 FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS. THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT SNOW TO THE AREA ONCE AGAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1152 PM EST SAT FEB 28 2015 A DRY SW FLOW AROUND HIGH PRES SHIFTING TOWARD THE MID ATLANTIC STATES SHOULD BRING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU THIS FCST PERIOD. SOME THICKER CLOUDS WILL ARRIVE TONIGHT IN ADVANCE OF AN APPROACHING LOW PRES TROF...BUT THE LOW-LEVELS SHOULD REMAIN DRY ENOUGH TO MAINTAIN VFR CIGS EVEN IF THERE IS SOME VERY LIGHT SNOW OR FLURRIES AT KIWD AND KCMX. GUSTIER W WINDS WILL DEVELOP LATE SUN MORNING/EARLY AFTN AT KCMX AFTER SFC TROF PASSAGE BUT THEN WIND GUSTS SHOULD DIE DOWN SUN EVENING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 AM EST SUN MAR 1 2015 NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 AM EST SUN MAR 1 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM EST SUN MAR 1 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS. MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN. MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE DISTURBANCES. TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE 25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL. TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85 THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN THAT AREA. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 259 PM EST SAT FEB 28 2015 GOOD AGREEMENT FM THE MODELS ON OVERALL LOOK OF LARGE SCALE PATTERN THROUGH THE EXTENDED. TROUGH AND COLD AIR THAT HAS DOMINATED FOR FEBRUARY EASES FIRST PART OF THE WEEK. JUST BEFORE THAT OCCURS THERE COULD BE SOME LIGHT LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT FOR AREAS FAVORED BY WNW WINDS. SOUNDINGS INDICATE INVERSIONS UP TO 5KFT WITH A LOT OF THE MOIST LAYER IN THE DGZ. LACK OF OPEN WATER WILL HAMPER THE LES...BUT WILL CARRY SCATTERED POPS FOR SNOW BELTS EAST OF MQT AND P53. LES COULD LINGER AS FLURRIES ON MONDAY MORNING...BUT WILL OPT FOR DRY FORECAST AS HIGH PRESSURE RIDGE SHOULD BE PUTTING AN END TO THE LES. WITH A NW LOW-LEVEL FLOW...MODELS HANG ON TO LOW CLOUDS PROBABLY ENHANCED DUE TO DAYTIME HEATING. MODELS MAY BE OVERDOING LOW-LEVEL RH THOUGH...SO WILL JUST GO PARTLY CLOUDY FOR DAYTIME ON MONDAY. HIGHS BOUNCE UP INTO THE 20S...THOUGH WILL REMAIN ONLY TO AROUND 20 OVER EAST WITH LINGERING NW WINDS OFF ICE OF LK SUPERIOR MOST OF THE DAY. CLOUDS THICKEN ON MONDAY NIGHT AHEAD OF DOUBLE BARRELLED LOW PRESSURE SYSTEM THAT MOVES OVER THE REGION ON TUESDAY. TEMPS MAY FALL QUICKLY OVER THE EAST CWA ON MONDAY NIGHT...BUT WILL BE IN THE TEENS ELSEWHERE. ON TUESDAY...NORTHERN STREAM LOW IS THE ONE AFFECTING ALASKA THIS AFTN AND THE SOUTHERN STREAM LOW IS FORECAST TO EMERGE OUT OF GENERAL TROUGHING CURRENTLY OVER THE SOUTHWEST CONUS. H85-H7/H7-H5 Q-VECTOR CONVERGENCE AND MOISTURE ADVECTION AHEAD OF SFC-H85 TROUGHS WITH H7 MIXING RATIOS 2-3 G/KG SUPPORT POTENTIAL FOR MODERATE SNOWFALL OVER EAST HALF OF UPR MICHIGAN. BLEND OF QPF ALONG WITH EXPECTED SLR/S IN THE 13-18:1 RANGE POINT TO SNOWFALL RANGING FM 2-4 INCHES/3-5 INCHES. KIND OF SEEMS THAT THERE MAY BE TWO MAIN TIMES OF SNOW WITH THE SYSTEM...LATE MONDAY NIGHT INTO TUESDAY MORNING...THEN AGAIN TUESDAY AFTN INTO EARLY TUESDAY EVENING. MODELS ARE LOCKED IN THAT THE TUESDAY AFTN AND TUESDAY EVENING TIME FRAME WILL FEATURE THE HEAVIEST SNOW...POSSIBLY WITH SNOWFALL RATES AROUND 1 INCH PER HOUR. IMPACT COULD BE ON THE HIGHER SIDE TOO AS THE HEAVIEST SNOW COULD FALL DURING THE AFTN AND EVENING COMMUTE. WILL CONTINUE TO MENTION IN THE HWO AND EHWO GRAPHICS. REPRIEVE IN THE COLD AIR IS BRIEF AS MORE COLD AIR...CURRENTLY UPSTREAM OF THE LOW PRESSURE SYSTEM OVER ALASKA...CHARGES IN LATE TUESDAY NIGHT INTO WEDNESDAY AND LINGERS THROUGH LATE WEEK. RETURN OF THE COLD WITH H85 TEMPS BLO -20C WILL LEAD TO LAKE EFFECT FOR NW FLOW AREAS. SOUNDINGS SHOW INVERSIONS START OUT AT 5KFT ON TUESDAY NIGHT OVER EASTERN LK SUPERIOR BUT RISE UP TO 8KFT ON WEDNESDAY. EXTENT OF OVER-WATER INSTABILITY AND DEPTH OF THE CONVECTIVE LAYER SUGGESTS LOCALLY MODERATE SNOW SHOWERS WILL BE POSSIBLE FOR MAINLY WNW-NW FLOW AREAS. OVERALL THE LOW VSBY WITH SMALLER SNOWFLAKES WILL BE THE LARGER IMPACT. WINDS 25-30 KTS SO MAY ALSO HAVE BLSN ALONG THE SHORE...ESPECIALLY IN THE SNOW BELTS EAST OF MQT. WITH ENOUGH MOISTURE INLAND ON WEDNESDAY...MAY ALSO SEE DIURNALLY ENHANCED SNOW SHOWERS WITH PERIODS OF GUSTY WINDS/LOWER VSBY. WINDS BACK W-WSW ON WEDNESDAY NIGHT WHICH WILL END THE LES ALONG MOST OF LK SUPERIOR. TEMPS INLAND WILL FALL OFF WELL BLO ZERO. WINDS WILL BE ON THE DECLINE BUT MAY STILL BE STRONG ENOUGH TO PRODUCE NEAR ADVISORY WIND CHILLS THURSDAY MORNING OVER PARTS OF THE CWA. HIGH PRESSURE BUILDING OVER THE NORTHERN PLAINS BY THURSDAY SLIDES TO THE OHIO VALLEY INTO FRIDAY AS LOW PRESSURE SYSTEM CROSSING NORTHERN ONTARIO PUSHES A WARM FRONT ACROSS THE UPPER GREAT LAKES. MID-LEVEL MOISTURE H85-H7 AND WEAK LIFT MAY TRIGGER A FEW SNOW SHOWERS OR FLURRIES THURSDAY NIGHT INTO FRIDAY MORNING. GFS AND ECMWF BOTH SHOW MAIN FORCING STAYING OVER LK SUPERIOR AND TO THE NORTH. ANOTHER COLD FRONT WORKS THROUGH ON FRIDAY NIGHT WITH MORE COLD AIR SETTLING OVER THE AREA BY NEXT SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1152 PM EST SAT FEB 28 2015 A DRY SW FLOW AROUND HIGH PRES SHIFTING TOWARD THE MID ATLANTIC STATES SHOULD BRING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU THIS FCST PERIOD. SOME THICKER CLOUDS WILL ARRIVE TONIGHT IN ADVANCE OF AN APPROACHING LOW PRES TROF...BUT THE LOW-LEVELS SHOULD REMAIN DRY ENOUGH TO MAINTAIN VFR CIGS EVEN IF THERE IS SOME VERY LIGHT SNOW OR FLURRIES AT KIWD AND KCMX. GUSTIER W WINDS WILL DEVELOP LATE SUN MORNING/EARLY AFTN AT KCMX AFTER SFC TROF PASSAGE BUT THEN WIND GUSTS SHOULD DIE DOWN SUN EVENING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 AM EST SUN MAR 1 2015 NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1135 PM CST Sat Feb 28 2015 ...AVIATION UPDATE... .UPDATE... FREEZING RAIN AND LIGHT SNOW WILL CONTINUE TO IMPACT SOUTH CENTRAL MISSOURI AFTER MIDNIGHT. ALL OTHER LOCATIONS WILL BE DEALING MAINLY WITH FREEZING DRIZZLE DEVELOPING AS WE HEAD INTO THE MONDAY MORNING HOURS. DUE TO THE FREEZING DRIZZLE CAUSING TRAVEL IMPACTS...THE HEADLINES WILL REMAIN IN EFFECT FOR NOW. && .SHORT TERM...(This Evening through Sunday Night) Issued at 307 PM CST SAT FEB 28 2015 A large area of snow has blanketed all of the Missouri Ozarks and extreme southeastern Kansas as of mid afternoon. Visibilities were pretty much below one mile over all areas...with occasional observations indicating quarter mile visibilities with heavy snow. Snowfall accumulations up through 3 PM have been in the 1-3" range. We suspect that some locations across extreme southeastern Kansas and west-central Missouri may be in that 3-4" range. As we head into late this afternoon and this evening, short term models are beginning to change their tune a bit. Both the RAP and the HRRR have somewhat backed off on a secondary band of snow developing along the I-44 corridor this evening. Even the 18Z NAM has trended this way. Instead, models gradually take the large area of moderate to occasionally heavy snow to the east and northeast with the back edge of the heavier snow moving east across the Ozarks this evening. This would tend to make sense as low level isentropic upglide and a weak upper level jet coupling structure shift towards the Mid Mississippi Valley. We will still have to watch for some banding of snow as models do indicate some slugs of increased 700 mb frontogenesis...especially along and north of the I-44 corridor. As we head into later tonight, the main area of snow will have shifted east of the area. Pockets of light snow and flurries will be left in its wake. While snow intensity will be on the downward trend this evening (again from west to east), it will tend to accumulate more efficiently given that the sun will have set. Models are also indicating perhaps some loss of cloud ice later tonight. Additionally, models still bring a warm nose into southern Missouri by late tonight. Thus, we are continuing a mention of either light freezing rain or freezing drizzle. This trend will then continue into Sunday morning with pockets of light snow and drizzle/freezing drizzle. We have slowed the progress of the surface freezing line to the north by a few hours...which does keep the door open a bit longer for minor ice accumulation. One thing we will have to watch very closely is what will be a good setup for a banded snow event from late tonight into Sunday morning up towards I-70. Models continue to indicate strong 700 mb frontogenesis and available negative EPV becoming juxtaposed with a favorable upper level jet streak. If this materializes, it could put down a narrow swath of additional heavier snowfall. While this could glance our central Missouri counties, confidence is higher that it will remain just north of the area. Once we get into Sunday afternoon and especially Sunday night, the primary precipitation will be shifting east and southeast of the region. As for storm total ice and snow amounts, we have not changed much. Any ice accumulations are still expected to remain at or below five-hundredths of an inch. 1-3" of snow is expected across south-central Missouri. Accumulations near and north of the I-44 corridor will be in the 3-6" range. We still think a few isolated reports of around 7" will be possible. Given that any 6-7" amounts are expected to be isolated (if they occur at all), the current Winter Weather Advisory will be left intact. .LONG TERM...(Monday through Saturday) Issued at 307 PM CST SAT FEB 28 2015 By Monday morning, precipitation should push south of the region, at least temporarily, as high pressure noses south from the Dakotas. Highs on Monday look to reach the upper 30s in most locations. Precipitation will then return to the area Monday night into Tuesday, though at this point it appears that temperatures should be above freezing by the time rain begins to fall Monday night. Rain will continue through much of the day Tuesday, as low pressure at the surface deepens and lifts north across Kansas and northern Missouri. Breezy southwest winds during the day Tuesday will help temperatures warm into the low to mid 50s. Will continue to include a mention of thunder in the forecast for Tuesday, with guidance suggesting a couple hundred J/KG of CAPE making its way into the CWA. A strong cold front will then sweep across the area Tuesday afternoon and evening, with colder air quickly advecting into the area Tuesday night. We will need to carefully watch the potential for post frontal snow Tuesday night and Wednesday, as lift from a secondary trough axis may be enough to result in areas of snow on Wednesday. As it stands right now, the highest snow potential for Wednesday looks to be south of I-44, though this will be highly dependent on the eventual location of the front. The upper level flow will then flatten out a bit, with southwesterly flow developing at the surface for the end of the week into next weekend. This is suggestive of warmer temperatures for the end of the week, with highs perhaps (finally) approaching climatological averages by this time next weekend. && .AVIATION...(For the 06Z TAFS through 06Z Sunday Night) PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS WILL BE DEALING WITH IFR CEILINGS AND AT LEAST MVFR VISIBILITIES THROUGH TONIGHT AND MOST OF SUNDAY MORNING. MOST OF THE HEAVIER SNOW AND FREEZING RAIN HAS SHIFTED INTO SOUTH CENTRAL MISSOURI. ALL OTHER LOCATIONS WILL BE DEALING WITH FREEZING DRIZZLE HEADING INTO SUNDAY MORNING. LOOK FOR WINDS TO BE LIGHT AND VARIABLE. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...WINTER WEATHER ADVISORY until Noon CST Sunday FOR MOZ055-056-066- 067-077-078-088-089-093>098-101>106. WINTER STORM WARNING until Noon CST Sunday FOR MOZ057-058- 068>071-079>083-090>092. KS...WINTER WEATHER ADVISORY until Noon CST Sunday FOR KSZ073-097-101. && $$ UPDATE...Schaumann/Cramer SHORT TERM...Schaumann LONG TERM...Boxell AVIATION...Cramer
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
347 AM CST SUN MAR 1 2015 .SYNOPSIS... ISSUED AT 347 AM CST SUN MAR 1 2015 AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES UNLIKELY. TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS. WINDS WERE LIGHT AND VARIABLE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CST SUN MAR 1 2015 FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32 AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO 10 MPH SOUTH. FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3 WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA. WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 347 AM CST SUN MAR 1 2015 12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY. THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE 285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1 TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF 5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE 0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS. BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF THE WORK WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1110 PM CST SAT FEB 28 2015 A FEW LIGHT SNOW SHOWERS...CURRENTLY OVER NORTHEAST COLORADO... WILL MAKE THEIR WAY ACROSS SOUTHWEST NEBRASKA. AS THEY COME ACROSS...CEILINGS OF 2000-3000 FEET AGL AND VISIBILITY AT OR ABOVE 5SM ARE LIKELY...THOUGH VERY LOCALIZED. && .HYDROLOGY... ISSUED AT 347 AM CST SUN MAR 1 2015 THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROBERG SHORT TERM...ROBERG LONG TERM...JACOBS AVIATION...SPRINGER HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1138 PM CST SAT FEB 28 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 333 PM CST SAT FEB 28 2015 ZONAL FLOW REMAINS IN PLACE ACROSS THE REGION THIS AFTERNOON...WITH SATELLITE IMAGERY SHOWING THE SHORTWAVE DISTURBANCE WHICH BROUGHT ACCUMULATING SNOW TO SRN PORTIONS OF THE CWA CONTINUING TO SLIDE EAST THROUGH THE PLAINS. RADAR TRENDS SHOW THE BRUNT OF THE SNOWFALL HAS SHIFTED OFF INTO ERN KS/SERN NEB...WITH JUST SOME LIGHT SNOW/FLURRIES LINGERING ACROSS OUR ERN COUNTIES. REPORTS RECEIVED FROM PORTIONS OF NC KS HAD TOTALS TOPPING OUT AROUND 1.5 INCHES. AT THE SFC...THE CWA REMAINS IN BETWEEN HIGH PRESSURE NOW CENTERED OVER THE NERN CONUS AND LOW PRESSURE OVER THE HIGH PLAINS...KEEPING THOSE SRLY WINDS IN PLACE. TEMPS THIS AFTERNOON GOING PRETTY MUCH AS EXPECTED...WITH 3 PM TEMPS RUNNING THE WHOLE RANGE OF 20S. WITH THE FIRST WAVE SHIFTING EAST THROUGH THE AREA THIS AFTERNOON AND THE CWA SITTING IN A BIT OF A LULL...DECIDED TO KEEP THE EVENING HOURS DRY. DO HAVE POPS RETURNING POST 06Z TONIGHT...WITH THE POTENTIAL FOR A BIT MORE SNOW AS ANOTHER WEAKER SHORTWAVE DISTURBANCE AND THE ENTRANCE REGION OF A 140ISH KT UPPER LEVEL JET STREAK MOVES IN. EVEN THIS CLOSE TO THE POTENTIAL PRECIP...MODELS DO NO AGREE WITH WHAT THE CWA WILL SEE. 4KM AND SREF SHOW CHANCES AFFECTING AREAS SOUTH OF I-80...WHILE OTHERS LIKE THE RAP AND ECMWF SHOW BASICALLY NOTHING. INHERITED FORECAST INCLUDED SOME CHANCE POPS...AND ONLY MADE MINOR ADJUSTMENTS TO THOSE. SHOULD SNOW DEVELOP/MOVE INTO THE CWA...ONLY EXPECTING AN ADDITION FEW TENTHS OF A INCH OF ACCUMULATION. HAVE LINGERING LOW POPS DURING THE MORNING HOURS TOMORROW...WITH DRY CONDITIONS FOR THE AFTERNOON. WHILE PLENTY OF CLOUD COVER IS EXPECTED TONIGHT...WITH TIME TOMORROW SKY COVER SHOULD DIMINISH. WITH THIS DISTURBANCE MOVING THROUGH LATE TONIGHT/EARLY TOMORROW...EXPECTING A SWITCH IN WINDS TO THE NORTHWEST ACCOMPANYING A FRONTAL BOUNDARY. DID BUMP UP HIGHS A FEW DEGREES...AS MODELS SHOW SLIGHTLY WARMING TEMPS ALOFT WORKING IN THROUGH THE DAY WITH THOSE NWRLY WINDS /ALTHOUGH THEY ARE ONLY AROUND 10 MPH/. HIGHS CURRENTLY FORECAST TO REACH INTO THE MID 30S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 333 PM CST SAT FEB 28 2015 MAIN CHALLENGE WILL BE DETERMINING CHANCES OF PRECIPITATION LATE SUNDAY NIGHT THROUGH TUESDAY NIGHT AND PRECIPITATION TYPE LATE MONDAY NIGHT INTO TUESDAY MORNING. NUMERICAL MODELS AGREE QUITE WELL WITH SYNOPTIC FEATURES. A DEEP TROUGH IN THE WEST WILL CONTINUE TO APPROACH THE PLAINS FOR THE FIRST PART OF THE EXTENDED FORECAST. WHILE IN SOUTHWEST FLOW...THERE COULD BE GENERALLY LOW CHANCES OF PRECIPITATION AS LOW AMPLITUDE WAVES ARE KICKED OUT OF THE BASE OF THE TROUGH. NOT UNTIL THE TROUGH MAKES ITS WAY INTO AND EAST OF THE GREAT PLAINS WILL BE SHUT OFF THE POTENTIAL FOR PRECIPITATION. THE SPECIFICS AND TIMING ARE FAR FROM AGREED UPON BETWEEN NUMERICAL MODELS. GENERALLY NEED TO GO WITH LOW CHANCES FOR MOST OF THE FIRST HALF OF THE LONG TERM FORECAST TO ESSENTIALLY COVER OUR BASES. CONFIDENCE IS RATHER LOW REGARDING TIMING OF ANY LULLS ALONG WITH PRECIPITATION AS BOUTS OF SNOW MAY BE RELATIVELY SHORT LIVED. THE NAM INDICATES ISENTROPIC LIFT FOR MONDAY...GIVING US A SHOT AT SOME RAIN/SNOW. BOTH THE NAM AND GFS INDICATE CONTINUED ISENTROPIC LIFT TOWARD LATE MONDAY NIGHT...BUT THE NAM INDICATES A LOSS OF SATURATION IN THE DENDRITIC GROWTH ZONE...SO THERE COULD BE A SHORT PERIOD OF FREEZING DRIZZLE BEFORE ISENTROPIC DOWNGLIDE ENSUES. STILL...THERE IS SO MUCH INCONSISTENCY AND LACK OF AGREEMENT...I CONTINUE TO BE QUITE SKEPTICAL OF THIS...SO I WILL PROBABLY CONTINUE TO LEAVE THIS OUT OF THE FORECAST FOR NOW AND STICK WITH SNOW. ANOTHER THING TO KEEP AN EYE ON IS WIND SPEED IN COMBINATION WITH SNOW FALLING FOR TUESDAY BEHIND A COLD FRONT. NORTHWEST WINDS AT 30 MPH GUSTING TO 40 MPH ARE EXPECTED...AND WITH UP TO 2 INCHES OF SNOWFALL...WE COULD EASILY HAVE REDUCED VISIBILITY. WIND CHILLS ON WEDNESDAY MORNING DID NOT DIP QUITE LOW ENOUGH TO MENTION IN THE HWO. ONCE WE GET THE TROUGH EAST OF US...WE WILL BE MORE CONFIDENTLY DRY AND EVENTUALLY WARM UP TOWARD NEXT WEEKEND...MAYBE EVEN NEAR OR ABOVE NORMAL FOR A CHANGE AS A RIDGE IN THE WEST NUDGES EAST. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1138 PM CST SAT FEB 28 2015 VFR CONDITIONS ARE FORECAST THROUGH THE NEXT 24 HOURS...ALTHOUGH CONDITIONS WILL NEED TO BE MONITORED FOR A PERIODIC MVFR CEILING. HIGH-LEVEL CLOUDS NEAR 15000FT AGL WILL REMAIN POSSIBLE THROUGH MUCH OF THE TAF PERIOD. OCCASIONAL STRATUS NEAR 2000FT AGL WILL ALSO BE POSSIBLE THROUGH THE FIRST HALF OF THE TAF PERIOD...BUT THE PROBABILITY OF THIS STRATUS MATERIALIZING IS TOO LOW FOR INCLUSION IN THE TAFS AT THIS TIME. THE SURFACE WIND WILL REMAIN LIGHT AND VARIABLE TONIGHT BEFORE BECOMING MORE ESTABLISHED FROM THE NORTHWEST DURING THE DAY SUNDAY. VISIBILITY RESTRICTION IS NOT EXPECTED AT EITHER TAF SITE THROUGH THE NEXT 24 HOURS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADP LONG TERM...HEINLEIN AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1008 PM PST SAT FEB 28 2015 .SYNOPSIS...A STORM SYSTEM CONTINUES TO DROP SOUTH ACROSS CALIFORNIA RESULTING IN GUSTY WINDS AND SHOWERS ACROSS PORTIONS OF THE AREA. AS THE STORM DROPS OFF THE COAST OF SOUTHERN CALIFORNIA ON SUNDAY IT WILL PUSH A BAND OF STEADIER PRECIPITATION INTO THE MOJAVE DESERT THAT WILL LAST THROUGH SUNDAY NIGHT INTO MONDAY MORNING. ELSEWHERE ACROSS THE AREA ON SUNDAY SHOWERS ARE POSSIBLE. UNSETTLED WEATHER IS POSSIBLE ACROSS THE AREA INTO TUESDAY NIGHT BEFORE A DRYING AND WARMING TREND TAKES PLACE. && .UPDATE...THE LATEST RADAR WAS NOT TOO IMPRESSIVE WITH MEANINGFUL RETURNS ACROSS THE AREA THIS EVENING. BASED ON THE OPERATIONAL MODELS AND THE HRRR AS WELL AS RADAR TRENDS, I ELECTED TO TRIM BACK POPS FURTHER ACROSS THE MOJAVE DESERT FOR THE REST OF THE OVERNIGHT PERIOD. WHILE THE THREAT OF SHOWERS IN THE SOUTHERN GREAT BASIN DOES NOT LOOK TO IMPRESSIVE AT THIS TIME, MODELS SHOW ENOUGH MID-LEVEL MOISTURE AND ENERGY ACROSS THE AREA OVERNIGHT THAT IT CANNOT BE COMPLETELY DISCOUNTED EITHER AND THUS POPS THERE WERE LEFT AS IS. FOR THE SUNDAY AFTERNOON-MONDAY EVENT, THINGS STILL LOOK GOOD FOR A BAND OF STEADIER PRECIPITATION TO IMPACT THE SOUTHEASTERN AND EVENTUALLY EASTERN THIRD OF THE AREA. THE HRRR APPEARS TOO AGGRESSIVE SPREADING THIS BAND ON BASED ON THE LATEST SATELLITE IMAGERY BUT BY THE AFTERNOON AND ESPECIALLY EVENING THIS BAND SHOULD MAKE PROGRESS INTO OUR AREA. A FEW CONCERNS WILL BE POTENTIAL HYDRO ISSUES IN MOHAVE COUNTY FOR MINOR FLOODING IN POOR DRAINAGE AREAS AS WELL AS THE NEED FOR WINTER WEATHER HEADLINES IN LINCOLN COUNTY WHERE SNOW LEVELS ARE EXPECTED TO BE 5500 FEET AND FALL TO 5000 FEET. AREAS NORTH OF PIOCHE AS WELL AS TOWARD THE UTAH BORDER SUCH AS PANACA SUMMIT COULD SEE SEVERAL INCHES OF SNOW IN THIS TIME FRAME MAKING FOR TRICKY TRAVEL. && .AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS AT 8-12 KTS ARE EXPECTED OVERNIGHT. FEW-SCT CLOUDS AOA 7K FEET WITH CLOUDS INCREASING OVERNIGHT INTO SUNDAY WITH BASES LOWERING THROUGH THE DAY ON SUNDAY. THERE IS POTENTIAL FOR A PERIOD OF STEADY RAIN IMPACTING THE LAS VEGAS VALLEY LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. CIGS BELOW 5K FEET AND REDUCED VSBY ARE POSSIBLE WITH MOUNTAIN OBSCURATIONS LIKELY. RAIN SHOULD TAPER OFF TO SHOWERS BY MONDAY AFTERNOON. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...SHOWERS WILL BE AROUND OVERNIGHT MAINLY NORTH OF A KDAG-KCDC LINE. CIGS AS LOW AS 4K-8K FEET ARE POSSIBLE IN AND NEAR ANY SHOWERS. OTHERWISE EXPECT DRY CONDITIONS WITH FEW-SCT CLOUDS AOA 7K-10K FEET. WINDS SHOULD FAVOR TYPICAL DIURNAL TRENDS. FOR SUNDAY, EXPECT WINDS MAINLY 10 KTS OR LESS WITH WINDS FAVORING TYPICAL DIURNAL DIRECTIONAL TRENDS. CLOUDS SHOULD INCREASE WITH BASES LOWERING THROUGH THE DAY. STEADIER PRECIPITATION IS EXPECTED AFTER 21Z SUNDAY INTO SUNDAY NIGHT SOUTH OF KDAG-KELY LINE WITH SNOW LEVELS BETWEEN 5500 AND 6500 FEET. ISO-SCT SHOWERS ARE EXPECTED NORTHWEST OF THIS LINE. EXPECT CIGS BELOW 5K FEET AND VSBY REDUCED TO MVFR OR LOWER AT TIMES. MOUNTAIN OBSCURATIONS ARE LIKELY. STEADY PRECIPITATION SHOULD TAPER TO SHOWERS BETWEEN 12Z AND 18Z ON MONDAY. && .PREVIOUS DISCUSSION... ISSUED AT 230 PM PST SAT FEB 28 2015 .SHORT TERM...THROUGH MONDAY NIGHT. OUR MID/UPPER LEVEL LOW PRESSURE SYSTEM IS CURRENTLY TRACKING SOUTH OVER WESTERN CALIFORNIA. UNDER A DESTABILIZING ATMOSPHERE AND UPPER LEVEL FORCING...SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF SOUTHERN NEVADA AND NORTHWEST ARIZONA. THIS ACTIVITY SHOULD CONTINUE AND MAY INCREASE IN COVERAGE A LITTLE THROUGH THIS EVENING. THERE HAVE BEEN A FEW LIGHTNING STRIKES OVER SOUTHWEST UTAH AND CENTRAL NYE COUNTY...WHICH WILL REMAIN POSSIBLE THROUGH THIS EVENING. THEN...THE LATEST HIRES GUIDANCE CONTINUES TO INDICATE A MORE NORTHERLY SHIFT LATER THIS EVENING AND COVERAGE DIMINISHING QUITE A BIT LATE TONIGHT. DID DECREASE POPS...BUT MIGHT NOT BE LOW ENOUGH IN MANY LOCATIONS IF THE GUIDANCE IS CORRECT. WILL SEE HOW THINGS TREND THROUGH THE EVENING HOURS. DID INCREASE POPS ACROSS ESMERALDA AND CENTRAL NYE OVERNIGHT AS THE FORCING AND PRECIP APPEARS TO FOCUS THERE AS THE UPPER LOW SHIFTS SOUTH. SNOW LEVELS ARE AROUND 5500-6500 FEET AND ARE EXPECTED TO DROP TO 4500-5500 FEET BY SUNDAY MORNING ACROSS OUR NORTH. ANY PRECIP ACROSS OUR NORTH WOULD FALL AS SNOW AROUND 5000-5500 FEET AND ACCUMULATE GENERALLY 1-3 INCHES...LOCALLY HIGHER ABOVE 7000 FEET. FARTHER SOUTH WE FIND GUSTY WEST-SOUTHWEST WINDS THIS AFTERNOON...WHICH WILL LAST INTO THIS EVENING. THE WIND ADVISORY REMAINS IN EFFECT. WIND SPEEDS SHOULD DECREASE OVERNIGHT. AS THE LOW CONTINUES TO DROP SOUTH...IT WILL PIVOT AND TAP INTO A PLUME OF SUBTROPICAL MOISTURE AND DIRECT IT NORTH ACROSS THE LOWER SOUTHERN CALIFORNIA DESERTS AND TOWARD THE COLORADO RIVER VALLEY SUNDAY MORNING INTO SUNDAY NIGHT. LATEST OPERATIONAL MODELS HAVE NOT VARIED TOO MUCH FROM LAST NIGHTS MODEL RUNS. THE PLUME OF MOISTURE IS FOCUSED ON MOHAVE COUNTY WITH THE WESTERN EDGES EXTENDING INTO LINCOLN...CLARK...AND SAN BERNARDINO COUNTIES. BELIEVE THERE WILL BE A SHARP CUTOFF OF THE HEAVIER PRECIP ON THE WESTERN SIDE...WHICH WILL LIKELY HAVE TO BE FINE-TUNED WHEN THE PRECIP BAND FINALLY FORMS. FARTHER WEST WOULD SEE MORE SHOWERY ACTIVITY. SUNDAY AFTERNOON THROUGH SUNDAY NIGHT WOULD BE THE BEST CHANCE OF RAIN AND HIGH ELEVATION SNOW...SO DID NOT MAKE MANY CHANGES TO THE RUNNING SUNDAY-SUNDAY NIGHT FORECAST. WITH THE PRECIP ORIGINATING FROM A WARM SOURCE REGION...SNOW LEVELS WILL BE RATHER HIGH ACROSS SOUTHERN MOHAVE COUNTY /GREATER THAN 6500 FEET/ WITH LEVELS OF 5500-6500 FEET ANTICIPATED IN NORTHERN MOHAVE COUNTY SUNDAY THROUGH SUNDAY NIGHT. WILL HAVE TO KEEP AN EYE ON POTENTIAL SNOW ACCUMULATIONS ACROSS THE HIGHER ELEVATIONS OF NORTHERN MOHAVE COUNTY SUNDAY NIGHT INTO MONDAY MORNING WITH THAT MOISTURE TAP...BUT RIGHT NOW NOT LOOKING LIKE ANY HEADLINES ARE NEEDED. WEST OF MOHAVE COUNTY...SNOW LEVELS SHOULD RANGE BETWEEN 4500-5500 FEET. DID INCREASE QPF ACROSS MOHAVE COUNTY SOME MORE...WITH THE POTENTIAL FOR OVER AN INCH OF LIQUID PRECIPITATION SUNDAY THROUGH MONDAY. AS MENTIONED IN THE PREVIOUS DISCUSSION...THIS MAY RESULT IN MINOR FLOODING IN POOR DRAINAGE AREAS AS WELL AS RAPID RISES IN WASHES. WHILE THE MAIN PLUME OF MOISTURE CONTINUES TO TAKE AIM ON MOHAVE COUNTY...CANNOT RULE OUT ADDITIONAL SHIFTS EITHER WEST OR EAST. FOR EXAMPLE...THE 18Z NAM CAME IN A LITTLE FARTHER WEST. NOT SOLD ON THIS SOLUTION THOUGH AS THE 18Z RUN YESTERDAY DID THE SAME THING BEFORE TRENDING THE PLUME BACK OVER MOHAVE COUNTY LAST NIGHT. SO...PLEASE KEEP UP TO DATE WITH THE LATEST FORECAST INFORMATION. ALSO FOR MONDAY...WEST-SOUTHWEST WINDS WILL BECOME GUSTY ONCE AGAIN. NOT LOOKING AT WIND ADVISORY LEVEL WINDS AT THIS TIME BUT GUSTY NONETHELESS. AS FOR TEMPERATURES...THE LAS VEGAS VALLEY HAS REACHED THE LOWER 60S FOR MANY LOCATIONS AS OF THIS WRITING. THIS SHOULD ALLOW FEBRUARY TO GO DOWN AS THE WARMEST ON RECORD AS WELL AS THE WARMEST METEOROLOGICAL WINTER ON RECORD FOR LAS VEGAS. QUITE IMPRESSIVE! TOMORROW SHOULD BE A FEW DEGREES COOLER ACROSS THE ENTIRE REGION WITH SIMILAR TEMPERATURES EXPECTED TO CONTINUE MONDAY. .LONG TERM...TUESDAY THROUGH SATURDAY. A QUICK OVERVIEW OF THE EXTENDED: MODELS FORECAST AN AREA OF LOW PRESSURE ALONG THE SOUTHERN CAL COAST EARLY TUESDAY MORNING MOVING TO NORTHERN BAJA BY WEDNESDAY MORNING. ADDITIONAL SHORTWAVE ENERGY SLIDES DOWN ALONG THE WEST COAST WEDNESDAY AND MERGES WITH THE LOW THURSDAY AND NUDGES IT EASTWARD. HIGH PRESSURE BUILDS OVER THE SOUTHWEST FRIDAY AND IS THEN PUSHED EAST SATURDAY AS A PACIFIC TROUGH APPROACHES FROM THE WEST. SHOWER ACTIVITY COULD LINGER THROUGH TUESDAY BUT ANY PRECIPITATION AMOUNTS WILL BE LIGHT. SKIES WILL BEGIN TO CLEAR...ESPECIALLY LATE TUESDAY WITH A BATCH OF HIGH CLOUDS POSSIBLE WEDNESDAY AS AN UPPER DISTURBANCE MOVES SOUTH ALONG THE COAST. DRY AND MAINLY CLEAR CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY BEFORE MORE HIGH CLOUDS MOVES INTO THE AREA SATURDAY. NORTH WINDS ARE EXPECTED TUESDAY AND WEDNESDAY ACROSS MUCH OF THE AREA THEN LINGERING ALONG THE COLORADO RIVER VALLEY THURSDAY AND FRIDAY. COOL CONDITIONS WILL LINGER THROUGH WEDNESDAY...WITH TEMPS REMAINING 8-10 DEGREES BELOW NORMAL FOLLOWED BY A WARMING TREND THROUGH THE REST OF THE WEEK. TEMPERATURES BY FRIDAY ARE EXPECTED TO BE RIGHT AROUND NORMAL. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE REQUESTED TO REPORT ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES TODAY THROUGH TUESDAY NIGHT. && $$ UPDATE/AVIATION...STACHELSKI PREVIOUS...PADDOCK/SALMEN FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
932 PM PST SAT FEB 28 2015 .SYNOPSIS...A STORM SYSTEM CONTINUES TO DROP SOUTH ACROSS CALIFORNIA RESULTING IN GUSTY WINDS AND SHOWERS ACROSS PORTIONS OF THE AREA. AS THE STORM DROPS OFF THE COAST OF SOUTHERN CALIFORNIA ON SUNDAY IT WILL PUSH A BAND OF STEADIER PRECIPITATION INTO THE MOJAVE DESERT THAT WILL LAST THROUGH SUNDAY NIGHT INTO MONDAY MORNING. ELSEWHERE ACROSS THE AREA ON SUNDAY SHOWERS ARE POSSIBLE. UNSETTLED WEATHER IS POSSIBLE ACROSS THE AREA INTO TUESDAY NIGHT BEFORE A DRYING AND WARMING TREND TAKES PLACE. && .UPDATE...THE LATEST RADAR WAS NOT TOO IMPRESSIVE WITH MEANINGFUL RETURNS ACROSS THE AREA THIS EVENING. BASED ON THE OPERATIONAL MODELS AND THE HRRR AS WELL AS RADAR TRENDS, I ELECTED TO TRIM BACK POPS FURTHER ACROSS THE MOJAVE DESERT FOR THE REST OF THE OVERNIGHT PERIOD. WHILE THE THREAT OF SHOWERS IN THE SOUTHERN GREAT BASIN DOES NOT LOOK TO IMPRESSIVE AT THIS TIME, MODELS SHOW ENOUGH MID-LEVEL MOISTURE AND ENERGY ACROSS THE AREA OVERNIGHT THAT IT CANNOT BE COMPLETELY DISCOUNTED EITHER AND THUS POPS THERE WERE LEFT AS IS. FOR THE SUNDAY AFTERNOON-MONDAY EVENT, THINGS STILL LOOK GOOD FOR A BAND OF STEADIER PRECIPITATION TO IMPACT THE SOUTHEASTERN AND EVENTUALLY EASTERN THIRD OF THE AREA. THE HRRR APPEARS TO AGGRESSIVE SPREADING THIS BAND ON BASED ON THE LATEST SATELLITE IMAGERY BUT BY THE AFTERNOON AND ESPECIALLY EVENING THIS BAND SHOULD MAKE PROGRESS INTO OUR AREA. A FEW CONCERNS WILL BE POTENTIAL HYDRO ISSUES IN MOHAVE COUNTY FOR MINOR FLOODING IN POOR DRAINAGE AREAS AS WELL AS THE NEED FOR WINTER WEATHER HEADLINES IN LINCOLN COUNTY WHERE SNOW LEVELS ARE EXPECTED TO BE 5500 FEET AND FALL TO 5000 FEET. AREAS NORTH OF PIOCHE AS WELL AS TOWARD THE UTAH BORDER SUCH AS PANACA SUMMIT COULD SEE SEVERAL INCHES OF SNOW IN THIS TIME FRAME MAKING FOR TRICKY TRAVEL. && .AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS AT 8-12 KTS ARE EXPECTED OVERNIGHT. FEW-SCT CLOUDS AOA 7K FEET WITH CLOUDS INCREASING OVERNIGHT INTO SUNDAY WITH BASES LOWERING THROUGH THE DAY ON SUNDAY. THERE IS POTENTIAL FOR A PERIOD OF STEADY RAIN IMPACTING THE LAS VEGAS VALLEY LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. CIGS BELOW 5K FEET AND REDUCED VSBY ARE POSSIBLE WITH MOUNTAIN OBSCURATIONS LIKELY. RAIN SHOULD TAPER OFF TO SHOWERS BY MONDAY AFTERNOON. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...SHOWERS WILL BE AROUND OVERNIGHT MAINLY NORTH OF A KDAG-KCDC LINE. CIGS AS LOW AS 4K-8K FEET ARE POSSIBLE IN AND NEAR ANY SHOWERS. OTHERWISE EXPECT DRY CONDITIONS WITH FEW-SCT CLOUDS AOA 7K-10K FEET. WINDS SHOULD FAVOR TYPICAL DIURNAL TRENDS. FOR SUNDAY, EXPECT WINDS MAINLY 10 KTS OR LESS WITH WINDS FAVORING TYPICAL DIURNAL DIRECTIONAL TRENDS. CLOUDS SHOULD INCREASE WITH BASES LOWERING THROUGH THE DAY. STEADIER PRECIPITATION IS EXPECTED AFTER 21Z SUNDAY INTO SUNDAY NIGHT SOUTH OF KDAG-KELY LINE WITH SNOW LEVELS BETWEEN 5500 AND 6500 FEET. ISO-SCT SHOWERS ARE EXPECTED NORTHWEST OF THIS LINE. EXPECT CIGS BELOW 5K FEET AND VSBY REDUCED TO MVFR OR LOWER AT TIMES. MOUNTAIN OBSCURATIONS ARE LIKELY. STEADY PRECIPITATION SHOULD TAPER TO SHOWERS BETWEEN 12Z AND 18Z ON MONDAY. && .PREVIOUS DISCUSSION... ISSUED AT 230 PM PST SAT FEB 28 2015 .SHORT TERM...THROUGH MONDAY NIGHT. OUR MID/UPPER LEVEL LOW PRESSURE SYSTEM IS CURRENTLY TRACKING SOUTH OVER WESTERN CALIFORNIA. UNDER A DESTABILIZING ATMOSPHERE AND UPPER LEVEL FORCING...SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF SOUTHERN NEVADA AND NORTHWEST ARIZONA. THIS ACTIVITY SHOULD CONTINUE AND MAY INCREASE IN COVERAGE A LITTLE THROUGH THIS EVENING. THERE HAVE BEEN A FEW LIGHTNING STRIKES OVER SOUTHWEST UTAH AND CENTRAL NYE COUNTY...WHICH WILL REMAIN POSSIBLE THROUGH THIS EVENING. THEN...THE LATEST HIRES GUIDANCE CONTINUES TO INDICATE A MORE NORTHERLY SHIFT LATER THIS EVENING AND COVERAGE DIMINISHING QUITE A BIT LATE TONIGHT. DID DECREASE POPS...BUT MIGHT NOT BE LOW ENOUGH IN MANY LOCATIONS IF THE GUIDANCE IS CORRECT. WILL SEE HOW THINGS TREND THROUGH THE EVENING HOURS. DID INCREASE POPS ACROSS ESMERALDA AND CENTRAL NYE OVERNIGHT AS THE FORCING AND PRECIP APPEARS TO FOCUS THERE AS THE UPPER LOW SHIFTS SOUTH. SNOW LEVELS ARE AROUND 5500-6500 FEET AND ARE EXPECTED TO DROP TO 4500-5500 FEET BY SUNDAY MORNING ACROSS OUR NORTH. ANY PRECIP ACROSS OUR NORTH WOULD FALL AS SNOW AROUND 5000-5500 FEET AND ACCUMULATE GENERALLY 1-3 INCHES...LOCALLY HIGHER ABOVE 7000 FEET. FARTHER SOUTH WE FIND GUSTY WEST-SOUTHWEST WINDS THIS AFTERNOON...WHICH WILL LAST INTO THIS EVENING. THE WIND ADVISORY REMAINS IN EFFECT. WIND SPEEDS SHOULD DECREASE OVERNIGHT. AS THE LOW CONTINUES TO DROP SOUTH...IT WILL PIVOT AND TAP INTO A PLUME OF SUBTROPICAL MOISTURE AND DIRECT IT NORTH ACROSS THE LOWER SOUTHERN CALIFORNIA DESERTS AND TOWARD THE COLORADO RIVER VALLEY SUNDAY MORNING INTO SUNDAY NIGHT. LATEST OPERATIONAL MODELS HAVE NOT VARIED TOO MUCH FROM LAST NIGHTS MODEL RUNS. THE PLUME OF MOISTURE IS FOCUSED ON MOHAVE COUNTY WITH THE WESTERN EDGES EXTENDING INTO LINCOLN...CLARK...AND SAN BERNARDINO COUNTIES. BELIEVE THERE WILL BE A SHARP CUTOFF OF THE HEAVIER PRECIP ON THE WESTERN SIDE...WHICH WILL LIKELY HAVE TO BE FINE-TUNED WHEN THE PRECIP BAND FINALLY FORMS. FARTHER WEST WOULD SEE MORE SHOWERY ACTIVITY. SUNDAY AFTERNOON THROUGH SUNDAY NIGHT WOULD BE THE BEST CHANCE OF RAIN AND HIGH ELEVATION SNOW...SO DID NOT MAKE MANY CHANGES TO THE RUNNING SUNDAY-SUNDAY NIGHT FORECAST. WITH THE PRECIP ORIGINATING FROM A WARM SOURCE REGION...SNOW LEVELS WILL BE RATHER HIGH ACROSS SOUTHERN MOHAVE COUNTY /GREATER THAN 6500 FEET/ WITH LEVELS OF 5500-6500 FEET ANTICIPATED IN NORTHERN MOHAVE COUNTY SUNDAY THROUGH SUNDAY NIGHT. WILL HAVE TO KEEP AN EYE ON POTENTIAL SNOW ACCUMULATIONS ACROSS THE HIGHER ELEVATIONS OF NORTHERN MOHAVE COUNTY SUNDAY NIGHT INTO MONDAY MORNING WITH THAT MOISTURE TAP...BUT RIGHT NOW NOT LOOKING LIKE ANY HEADLINES ARE NEEDED. WEST OF MOHAVE COUNTY...SNOW LEVELS SHOULD RANGE BETWEEN 4500-5500 FEET. DID INCREASE QPF ACROSS MOHAVE COUNTY SOME MORE...WITH THE POTENTIAL FOR OVER AN INCH OF LIQUID PRECIPITATION SUNDAY THROUGH MONDAY. AS MENTIONED IN THE PREVIOUS DISCUSSION...THIS MAY RESULT IN MINOR FLOODING IN POOR DRAINAGE AREAS AS WELL AS RAPID RISES IN WASHES. WHILE THE MAIN PLUME OF MOISTURE CONTINUES TO TAKE AIM ON MOHAVE COUNTY...CANNOT RULE OUT ADDITIONAL SHIFTS EITHER WEST OR EAST. FOR EXAMPLE...THE 18Z NAM CAME IN A LITTLE FARTHER WEST. NOT SOLD ON THIS SOLUTION THOUGH AS THE 18Z RUN YESTERDAY DID THE SAME THING BEFORE TRENDING THE PLUME BACK OVER MOHAVE COUNTY LAST NIGHT. SO...PLEASE KEEP UP TO DATE WITH THE LATEST FORECAST INFORMATION. ALSO FOR MONDAY...WEST-SOUTHWEST WINDS WILL BECOME GUSTY ONCE AGAIN. NOT LOOKING AT WIND ADVISORY LEVEL WINDS AT THIS TIME BUT GUSTY NONETHELESS. AS FOR TEMPERATURES...THE LAS VEGAS VALLEY HAS REACHED THE LOWER 60S FOR MANY LOCATIONS AS OF THIS WRITING. THIS SHOULD ALLOW FEBRUARY TO GO DOWN AS THE WARMEST ON RECORD AS WELL AS THE WARMEST METEOROLOGICAL WINTER ON RECORD FOR LAS VEGAS. QUITE IMPRESSIVE! TOMORROW SHOULD BE A FEW DEGREES COOLER ACROSS THE ENTIRE REGION WITH SIMILAR TEMPERATURES EXPECTED TO CONTINUE MONDAY. .LONG TERM...TUESDAY THROUGH SATURDAY. A QUICK OVERVIEW OF THE EXTENDED: MODELS FORECAST AN AREA OF LOW PRESSURE ALONG THE SOUTHERN CAL COAST EARLY TUESDAY MORNING MOVING TO NORTHERN BAJA BY WEDNESDAY MORNING. ADDITIONAL SHORTWAVE ENERGY SLIDES DOWN ALONG THE WEST COAST WEDNESDAY AND MERGES WITH THE LOW THURSDAY AND NUDGES IT EASTWARD. HIGH PRESSURE BUILDS OVER THE SOUTHWEST FRIDAY AND IS THEN PUSHED EAST SATURDAY AS A PACIFIC TROUGH APPROACHES FROM THE WEST. SHOWER ACTIVITY COULD LINGER THROUGH TUESDAY BUT ANY PRECIPITATION AMOUNTS WILL BE LIGHT. SKIES WILL BEGIN TO CLEAR...ESPECIALLY LATE TUESDAY WITH A BATCH OF HIGH CLOUDS POSSIBLE WEDNESDAY AS AN UPPER DISTURBANCE MOVES SOUTH ALONG THE COAST. DRY AND MAINLY CLEAR CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY BEFORE MORE HIGH CLOUDS MOVES INTO THE AREA SATURDAY. NORTH WINDS ARE EXPECTED TUESDAY AND WEDNESDAY ACROSS MUCH OF THE AREA THEN LINGERING ALONG THE COLORADO RIVER VALLEY THURSDAY AND FRIDAY. COOL CONDITIONS WILL LINGER THROUGH WEDNESDAY...WITH TEMPS REMAINING 8-10 DEGREES BELOW NORMAL FOLLOWED BY A WARMING TREND THROUGH THE REST OF THE WEEK. TEMPERATURES BY FRIDAY ARE EXPECTED TO BE RIGHT AROUND NORMAL. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE REQUESTED TO REPORT ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES TODAY THROUGH TUESDAY NIGHT. && $$ UPDATE/AVIATION...STACHELSKI PREVIOUS...PADDOCK/SALMEN FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS TULSA OK
1139 PM CST SAT FEB 28 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. WIDESPREAD IFR TO LIFR CONDITIONS ARE EXPECTED THROUGH SUNDAY MORNING ALONG WITH AREAS OF FREEZING DRIZZLE OR LIGHT FREEZING RAIN. SOME SLOW IMPROVEMENT WILL OCCUR SUNDAY AFTERNOON AND EVENING WITH ALL SITES BECOMING MVFR BY SUNDAY EVENING. && .PREV DISCUSSION... /ISSUED 846 PM CST SAT FEB 28 2015/ DISCUSSION... IT NOW LOOKS LIKE THE SNOW IS CONFINED TO EXTREME NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS AT THIS HOUR. FREEZING RAIN IS BECOMING MORE OF AN ISSUE WITH AREAS OF FREEZING RAIN AND SLEET ACROSS SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. A SOUTHWESTERLY LOW LEVEL JET OF AROUND 60 MPH CONTINUES TO CREATE ISENTROPIC LIFT ACROSS THE REGION THIS EVENING PRODUCING THE AREAS OF FREEZING RAIN AND SLEET. THIS IS EXPECTED TO PERSIST FOR A GOOD DEAL OF THE NIGHT. HAVE INCREASED ICE AMOUNTS SOME ACROSS EAST-CENTRAL OKLAHOMA INTO WESTERN ARKANSAS. STILL BELOW WARNING CRITERIA. THE HRRR SHOWS THE PRECIP TAPERING OFF AROUND 3 AM. WILL SEE MAINLY FREEZING DRIZZLE ACROSS THE REMAINDER OF NORTHEAST OKLAHOMA. THE TEMPERATURE HAS RISEN TO FREEZING OR JUST ABOVE ACROSS FAR SOUTHEAST OKLAHOMA. WILL CONTINUE ADVISORY AS IS FOR NOW. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR OKZ049-OKZ053- OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061- OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069- OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076. AR...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR ARZ001-ARZ002- ARZ010-ARZ011-ARZ019-ARZ020-ARZ029. && $$ AVIATION...05
AREA FORECAST DISCUSSION
NWS PUEBLO CO
414 AM MST SUN MAR 1 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 414 AM MST SUN MAR 1 2015 RADAR CONTINUES TO SHOW ECHOES OVR PORTIONS OF THE SANGRES THIS MORNING...WITH WEB CAMS SHOWING SNOW IN THE CENTRAL AND SW MTNS. THERE MAY BE OCNL SNOW SHOWERS IN SOME LOCATIONS OF THE SAN LUIS VALLEY AS WELL. HYR CLOUDS HAVE DECREASED OVR THE SERN PLAINS...BUT THERE ARE AREAS OF LOW CLOUDS AND FOG WITH THE POTENTIAL FOR SOME FLURRIES. AN UPR LOW WL REMAIN ALONG THE SRN CA COAST THRU THE DAY. THE UPR LOW IS FORECAST TO WEAKEN TONIGHT...WITH THE UPR TROF BEGINNING TO MOVE EASTWARD. W TO SW FLOW ALOFT WL CONTINUE ACRS CO TODAY AND TONIGHT. THIS WL ALLOW THE CONTINUED STREAM OF MSTR INTO THE CONTDVD. ALTHOUGH THE MTNS OF THE CONTDVD WL GET SEVERAL ADDITIONAL INCHES OF ACCUMULATION TODAY AND TONIGHT...THE ERN SAN JUAN MTNS WL STILL BE THE HARDEST HIT AREA. WINDS THIS MORNING ARE NOT REACHING BLIZZARD CRITERIA OVER ZONE 68...BUT LATER TODAY THEY ARE EXPECTED TO PICK UP AGAIN AND GUSTS OVERNIGHT SHOULD AGAIN BE QUITE STRONG...AND WITH THE HEAVY SNOW CONTINUING THE BLSN AND NEAR ZERO VSBYS WL BE QUITE DANGEROUS. WL LEAVE THE BLIZZARD WARNING AS IS. THE NAM THE GFS AND HRRR ARE SHOWING DRY CONDITIONS OVR THE SERN PLAINS AND I-25 CORRIDOR THRU EARLY AFTERNOON...SO WL REMOVE POPS IN THESE AREAS. PROBABLY WL NOT SEE MUCH IN THE WAY OF PCPN OVR MOST OF THE SAN LUIS VALLEY EITHER...BUT SOME ISOLD SHOWERS ARE STILL POSSIBLE. MODELS CONTINUE TO SHOW PCPN RAMPING UP OVR THE ERN MTNS AROUND MIDAFTERNOON AND SPILLING OUT OVR PORTIONS OF THE I-25 CORRIDOR THRU THE EVENING HOURS. THE LAST COUPLE DAYS...THE MODELS HAVE KEPT THE FOCUS OF THE PCPN MAINLY FROM THE WET MTNS AND NRN SANGRES AND LOCATIONS NORTH...NOT REALLY SHOWING ALL THAT MUCH FOR THE SRN SANGRES...AND THE NAM AND HRRR STILL HAVE THAT TREND. THIS MORNING THE GFS SHOWS MORE ACTIVITY OVR THE SRN SANGRES THIS AFTERNOON THAN THE HRRR AND NAM. EAST TO SOUTHEASTERLY UPSLOPE OVR EL PASO COUNTY THIS AFTERNOON AND EVENING HELP ENHANCE PCPN CHANCES AND WL KEEP POPS HIGH IN THIS AREA. THE MODELS SHOW LITTLE CHANCE FOR PCPN OVR MOST OF THE SERN PLAINS THIS AFTERNOON AND EVENING... BUT WL PUT SOME ISOLD POPS IN THE FORECAST. BY LATE NIGHT...PCPN OVR THE SERN PLAINS AND I-25 CORRIDOR SHOULD GENERALLY BE LIGHT...HOWEVER THE SOUTHERLY FLOW OVR EL PASO COUNTY SHOULD KEEP SNOW GOING ALTHOUGH IT SHOULD BE GENERALLY LIGHT BUT THERE SHOULD BE A LITTLE ACCUMULATION WHICH COULD MAKE FOR A SLIPPERY MONDAY MORNING COMMUTE. ALSO...THE NAM AND GFS CONTINUE TO SHOW THE POTENTIAL FOR A FEW TO SEVERAL INCHES OF SNOW ACCUMULATIONS OR THE NRN SANGRES... THE WET MTNS VALLEY AND FREMONT COUNTY THRU THE NIGHT. ONE CONCERN IS THAT IF LIGHT PCPN DOES OCCUR OVR THE FAR SERN PLAINS...THE SOUNDING PROFILE STILL DOES SHOW THE POTENTIAL FOR SOME LIGHT FREEZING DRIZZLE...BUT WL NOT MENTION IN THE FORECAST AT THIS TIME. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 414 AM MST SUN MAR 1 2015 ...UNSETTLED WEATHER CONTINUES THROUGH WEDNESDAY WITH DRIER AND WARMER WEATHER THEREAFTER... MONDAY-MONDAY NIGHT...SOUTHWEST FLOW ALOFT INCREASES AGAIN ACROSS THE REGION ON MONDAY AND BECOMES MORE WESTERLY MONDAY NIGHT WITH A STRONG SUBTROPICAL JET STREAM TRANSLATING ACROSS THE STATE AS SOUTHERN STREAM ENERGY ACROSS THE DESERT SW MERGES WITH ANOTHER PIECE OF ARCTIC AIR WITHIN A STRONG NORTHERN STREAM TROUGH DIGS ACROSS THE INTERMOUNTAIN WEST AND NORTHERN GREAT BASIN. SNOWFALL OVER AND NEAR THE MOUNTAINS LOOKS TO BE ON THE WANE EARLY MONDAY MONDAY MORNING BUT IS EXPECTED TO INCREASE AGAIN MONDAY AFTERNOON AND EVENING...ESPECIALLY OVER AND NEAR THE CONTDVD...WITH INCREASING MOISTURE...UVV AND OROGRAPHICS AHEAD OF THE COMBINING SYSTEMS. CURRENT WINTER WEATHER HIGHLIGHTS ACROSS THE HIGHER TERRAIN THROUGH THE DAY MONDAY MAY NEED TO BE EXTENDED INTO EARLY TUESDAY MORNING...WITH ANOTHER ROUND OF MODERATE TO HEAVY SNOWFALL EXPECTED...ESPECIALLY ALONG AND WEST OF THE DVD. IN ADDITION TO THE SNOW...INCREASING FLOW ALOFT WILL LEAD TO STRONG AND GUSTY SOUTHWEST TO WEST WINDS OF 25 TO 45 MPH AND AREAS OF BLOWING AND DRIFTING SNOW ACROSS THE HIGHER TERRAIN. FURTHER EAST...A FEW MORNING SHOWERS WILL BE POSSIBLE ACROSS THE EASTERN PLAINS WITH BREEZY TO WINDY CONDITIONS HELPING TO BOOST HIGHS MONDAY INTO THE 30S AND 40S AND KEEP OVERNIGHT LOWS FAIRLY MILD MAINLY IN THE 20S AND 30S. TUESDAY-WEDNESDAY NIGHT...STRONG WEST TO NORTHWEST FLOW ALOFT ACROSS THE AREA TUESDAY MODERATES THROUGH THE DAY WEDNESDAY AND WEDNESDAY AS NORTHERN STREAM TROUGH AND ARCTIC AIRMASS DIGS ACROSS THE ROCKIES AND INTO THE HIGH PLAINS. SOME DIFFERENCES IN TIMING OF ARCTIC FRONT ACROSS THE AREA WITH LEADING EDGE OF COLD AIR MOVING ACROSS EASTERN COLORADO EARLY TUESDAY MORNING AND HIGHS MOST LIKELY BEING REACHED BY MID MORNING WITH TEMPERATURES COOLING THEREAFTER. COULD SEE SOME SHOWERS ACROSS THE AREA WITH THE FRONT THOUGH BEST CHANCES OF LIGHT TO MODERATE SNOWFALL LOOKS TO BE LATER TUESDAY AFTERNOON AND NIGHT AS ANOTHER LOBE OF ENERGY AND SECONDARY SURGE OF COLD AIR DROPS ACROSS THE ROCKIES KEEPING TEMPERATURES WELL BELOW SEASONAL AVERAGES WITH LOWS MAINLY IN THE SINGLE DIGITS AND HIGHS MAINLY IN THE TEENS AND 20S. DRIER AIR AND SUBSIDENCE WITHIN THE MODERATING NORTHWEST FLOW ALOFT WILL ALLOW FOR SNOW TO GRADUALLY END WEDNESDAY AFTERNOON AND EVENING. THURSDAY-SATURDAY...A WARMING AND DRYING TREND REMAINS IN THE OFFING FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND AS UPPER LEVEL RIDGING BUILDS ACROSS THE WEST COAST AND INTO THE GREAT BASIN. LATEST MODELS...HOWEVER...ARE INDICATING ANOTHER WEAK WAVE WITHIN THE STRONGER NORTHWEST FLOW ALOFT ACROSS THE NORTH TIER OF STATES...DROPPING ACROSS THE ROCKIES ON SATURDAY. WITH THAT SAID...HAVE STAYED WITH MODEL CONSENSUS POPS WHICH BRINGS SLIGHT CHANCES FOR LIGHT SNOW ACROSS THE HIGHER TERRAIN ON SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 414 AM MST SUN MAR 1 2015 KCOS WL HAVE IFR OR MVFR CONDITIONS THRU ABOUT 16Z WITH LOW CLOUDS AND FOG REMAINING IN THE AREA. VFR CONDITIONS ARE THEN EXPECTED THRU ABOUT MID AFTERNOON. IN THE LATE AFTERNOON HOURS...SNOW IS EXPECTED TO MOVE INTO THE AREA WHICH WL CONTINUE THRU 12Z MON AND CONDITIONS WL AGAIN BECOME MVFR OR IFR. KPUB SHOULD SEE VFR CONDITIONS THRU THE EARLY EVENING AND THEN SNOW IS EXPECTED TO REDUCE VSBYS AND CIGS INTO THE MVFR OR IFR CATEGORY THRU THE NIGHT. KALS WL GENERALLY HAVE VFR CONDITIONS...HOWEVER SOME FOG IN THE AREA THIS MORNING WL BRING IFR CONDITIONS THRU ABOUT 16Z AND THERE WL BE THE POSSIBILITY OF SNOW SHOWERS IN THE VCNTY TODAY AND TONIGHT WHICH COULD CAUSE PERIODS OF MVFR OR IFR CONDITIONS. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060-061- 066-067-073-075. WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ059-064-065- 074. BLIZZARD WARNING UNTIL 11 PM MST MONDAY FOR COZ068. && $$ SHORT TERM...28 LONG TERM...MW AVIATION...28
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
356 AM MST SUN MAR 1 2015 .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 346 AM MST SUN MAR 1 2015 THE FLOW ALOFT WILL BECOME MORE SWLY TODAY AND THEN INCREASE TONIGHT AS AN UPPER LEVEL LOW REMAINS OVER CALIFORNIA. SO FAR MOST OF THE CWA IS ON THE SUBSIDENT SIDE OF THE UPPER LEVEL EXCEPT CLOSER TO THE WY BORDER WHERE OROGRPAHIC SNOWS HAVE BEEN OCCURRING OVER THE HIGHER TERRAIN OF BOULDER AND LARIMER COUNTIES. SOME OF THIS ACTIVITY HAS SPREAD ACROSS THE LOWER ELEVATIONS OF LARIMER COUNTY AND NWRN WELD COUNTY. APPEARS MOST OF THIS ACTIVITY WILL END AROUND 12Z EXCEPT IN THE MTNS. BY LATER THIS MORNING THRU EARLY AFTN DRIER AIR WILL SPREAD ACROSS THE MTNS WHICH WILL REDUCE SNOW CHANCES. BY LATE AFTN INTO THE EVENING HOURS ANOTHER SURGE OF MOISTURE IS SUPPOSED TO MOVE INTO THE MTNS. SATELLITE DOES SHOW ENHANCEMENT OVER ARIZONA SO IT APPEARS THAT THIS MOISTURE IS REAL. THUS SHOULD SEE AN INCREASE IN SNOW ACTIVITY IN THE MTNS. AT LOWER ELEVATIONS NOT SURE HOW THINGS ARE GOING TO EVOLVE. THE HRRR AND RAP SHOW SNOW DEVELOPING IN THE SRN FOOTHILLS AND AFFECTING SRN AREAS OF THE URBAN CORRIDOR AND PALMER DIVIDE BY LATE AFTN INTO THE EARLY HOURS. THUS WILL KEEP HIGHEST POPS OVE SRN AREAS OF CWA WITH LOWER POPS FURTHER NORTH. AS FOR HIGHS WILL KEEP READINGS N THE 20S OVER NERN CO EXCEPT OVER THE FAR NERN CORNER WHERE READINGS MAY RISE INTO THE LOWER 30S. OVERNIGHT SWLY FLOW WILL INTENSIFY WITH ABUNDANT MOISTURE IN THE MTNS. PLACEMENT OF UPPER LEVEL JET COULD ALLOW FOR SOME HEAVIER SNOWFALL LATE TONIGHT IN ZN 31 AND PORTIONS OF ZN 33 ALTHOUGH MID LVL TEMPS ARE WARMING QUITE A BIT WHICH COULD LIMIT AMOUNTS. OVER NERN CO THE LOW LVL FLOW WILL BECOME MORE SSE AFTER MIDNIGHT WITH STG DOWNSLOPING COMING OFF THE PALMER DIVIDE WHICH SHOULD DECREASE PCPN CHANCES FM DENVER SOUTH TO THE PALMER DIVIDE. CLOSER TO THE WY BORDER THE LOW LVL FLOW WILL BE MORE SELY SO COULD STILL SEE A CHC OF LIGHT SNOW OVERNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 346 AM MST SUN MAR 1 2015 VERY STRONG SOUTHWESTERLY JET LEVEL FLOW IS PROGGED OVER THE CWA MONDAY AND MONDAY NIGHT. THE PROGGED SPEEDS ARE IN THE 130 TO 160 KNOT RANGE AT JET LEVEL. BY TUESDAY...THE FLOW ALOFT BECOMES MORE WESTERLY THROUGH THE DAY AS AN UPPER TROUGH MOVES INTO COLORADO. THE UPPER TROUGH IS OVER THE STATE TUESDAY AFTERNOON WELL INTO THE EXTENDED PERIOD. THERE IS WEAK UPWARD QG VERTICAL VELOCITY PROGGED FOR THE CWA MONDAY...BUT IT BECOMES STRONGER BY AFTERNOON AND OVERNIGHT. ANOTHER BATCH OF UPWARD ENERGY MOVES ACROSS THE FORECAST AREA TUESDAY AFTERNOON WITH SUBSIDENCE BY TUESDAY NIGHT. THE BOUNDARY LAYER FLOW LOOKS TO BE SOUTH- SOUTHWESTERLY ON MONDAY. NORMAL DIURNAL PATTERNS SHOULD KICK IN MONDAY EVENING...THEN A COLD FRONT WITH UPSLOPE MOVES IN SOMETIME AFTER MIDNIGHT AND TUESDAY MORNING AT DAWN. NORTH-NORTHEASTERLY WINDS ARE PROGGED TUESDAY AND TUESDAY NIGHT. FOR MOISTURE...THERE IS BIT OVER THE PLAINS MONDAY...BUT DEEPER MOISTURE FOR THE MOUNTAINS. MOISTURE REMAINS PRETTY DEEP OVER THE MOUNTAINS MONDAY NIGHT...WITH AN INCREASE AFTER THE FRONT MOVES ACROSS FOR THE PLAINS. MOISTURE IS PRETTY DEEP IN ALL AREAS BY TUESDAY AFTERNOON AND NIGHT. THERE IS SOME QPF PROGGED OVER THE MOUNTAINS MONDAY THROUGH TUESDAY EVENING. FOR THE PLAINS THERE IS SOME MONDAY EVENING THROUGH TUESDAY NIGHT. FOR POPS...WILL NOT ALTER THINGS TO MUCH...MAY START THEM OVER THE PLAINS A BIT LATER ON MONDAY NIGHT/TUESDAY MORNING. NO HIGHLIGHTS RIGHT NOW...BUT MOUNTAINS MIGHT NEED SOMETHING. WE`LL SEE. FOR TEMPERATURES...MONDAY`S HIGHS ARE 4-11 C WARMER THAN TODAY`S EXPECTED HIGHS. TUESDAY`S HIGHS BEHIND THE FRONT COOL BACK OFF 11-18 C FROM MONDAY`S. DEPENDING HOW MUCH IT CLEARS OUT TUESDAY NIGHT/WEDNESDAY MORNING...WE COULD GET BELOW ZERO FOR LOWS OUT ON THE FOR THAT PERIOD. FOR THE LATER DAYS...WEDNESDAY THROUGH SATURDAY...MODELS HAVE THE UPPER TROUGH GET THROUGH THE CWA ON WEDNESDAY...THEN WEAK NORTHWESTERLY FLOW IS PROGGED FOR THE CWA WEDNESDAY NIGHT INTO FRIDAY MORNING. THEN FAIRLY WEAK WEST OR WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED THROUGH SATURDAY. MOISTURE IS LACKING...IT ACTUALLY LOOKS PRETTY DRY ALL FOUR DAYS. TEMPERATURES STAY BELOW SEASONAL NORMALS ALL FOUR DAYS. && .AVIATION...(FOR THE TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 346 AM MST SUN MAR 1 2015 SATELLITE SHOWS STRATUS AND SOME FOG DEVELOPING TO THE WEST AND NORTH OF DIA EARLY THIS MORNING AS A WK DENVER CYCLONE HAS DEVELOPED. IF SFC WINDS AT DIA BECOME LIGHT NNW THEN FOG AND STRATUS COULD DVLP IN THE NEXT FEW HOURS AND LINGER THRU AT LEAST 16Z. BY LATE MORNING EXPECT IFR CONDITIONS WHICH MAY LINGER THRU THE AFTN HOURS. AS FOR SNOW APPEARS BEST CHC LATE THIS AFTN AND EVENING WILL STAY TO THE WEST AND SOUTH OF DIA WITH ONLY LIGHT ACCUMULATIONS EXPECTED. WINDS WILL BE LIGHT AND VARIABLE THIS MORNING AND THE MORE ELY BY MIDDAY. BY THIS EVENING WINDS WILL BECOME MORE SELY AND THEN SLY AFTER MIDNIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RPK LONG TERM...RJK AVIATION...RPK
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1101 AM EST SUN MAR 1 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY. HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... TODAY...A WELL PRONOUNCED COASTAL TROUGH LINGERS JUST OFF THE SOUTHEAST U.S. COAST...WHILE A SURFACE WEDGE REMAINS FIRMLY ENTRENCHED ACROSS INLAND AREAS WITH THE WEAKENING PARENT HIGH POSITIONED NEAR THE MID-ATLANTIC COAST. ABUNDANT LOW AND MID LEVEL MOISTURE COMBINED WITH ISENTROPIC ASCENT CONTINUES TO SUPPORT GOOD COVERAGE OR RAIN ACROSS MAINLY CENTRAL AND NORTHERN PORTIONS OF THE FORECAST AREA LATE THIS MORNING. THE HRRR AND OTHER HIGH RESOLUTION MESOSCALE MODELS APPEAR TO BE HANDLING LOCATION/COVERAGE OF THE PRECIPITATION FAIRLY WELL...AND GENERALLY SHOW THE RAIN SHIELD LIFTING NORTHWARD THROUGH THE AFTERNOON. AS A RESULT...THE POP FORECAST SHOWS LOWERING RAIN CHANCES ACROSS SOUTHEAST GEORGIA THROUGH THE DAY...BUT PROBABILITIES PEAKING AT 60-80 PERCENT IN SOUTHEAST SOUTH CAROLINA EARLY THIS AFTERNOON BEFORE RAIN CHANCES LOWER AS WELL LATE IN THE DAY. THE TEMPERATURE FORECAST REMAINS VERY TRICKY. WHILE THE COASTAL TROUGH IS NOT EXPECTED TO SHIFT INLAND DUE TO THE COOL/STABLE SHELF WATERS...MOST OF THE MODELS CONTINUE TO SHOW SOME WARMER AIR IN THE BOUNDARY ADVECTING JUST INLAND ALONG THE COAST. WITH THE MOST RECENT UPDATE...HAVE LOWERED TEMPERATURES ALONG THE COAST JUST A BIT TO ACCOUNT FOR THE LATEST MODEL TRENDS...BUT TIGHTENED THE GRADIENT FURTHER BY LOWERING TEMPERATURES WELL INLAND NEAR THE CORE OF THE WEDGE. HIGH ARE NOW FORECAST TO RANGE FROM THE MID 40S WELL INLAND TO THE MID 50S NEAR THE COAST. TONIGHT...WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING INTO TONIGHT WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A CONCERN FOR DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING ADVECTS NE INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW CONFIDENCE AT THIS JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY FOG TO AREAS OF FOG AS A TREND. THERE WILL PROBABLY BE PATCHY DRIZZLE AROUND THE REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES AND THE SYNOPTIC OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT READINGS MANY BE STEADY OR RISING LATE. && .SHORT TERM /MONDAY THROUGH TUESDAY/... MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO LOW/MID 50S IN SOUTHEAST GEORGIA. TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY AFTERNOON/EVENING. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... AT KCHS...CIGS SHOULD BECOME IFR LATER THIS MORNING AS LIGHT RAINS DEVELOP AND SPREAD BOTH INLAND AND NORTH ALONG THE COASTAL CORRIDOR. AT SAV...CIGS LIKELY ALREADY LOCKED INTO IFR OR LOWER THROUGH 12Z MONDAY. BOTH SITES CAN EXPECT PERIODS OF LIGHT RAINS AND DRIZZLE TODAY WITH PRECIP PROBABLY LASTING LONGER INTO THE AFTERNOON AT KCHS. DESPITE THE HIGH CONFIDENCE IN CIGS BELOW 1 KFT...CONFIDENCE IS NOT GOOD WITH HOW FAR DOWN CIGS WILL BUILD AND AT WHAT TIME LATER TODAY AND TONIGHT. THE SYNOPTIC PATTERN FAVORS FOG AND DRIZZLE IN THE WAKE OF LIGHT RAINS AND WE PLAYED CONTINUED DETERIORATION THIS AFTERNOON AND TONIGHT WITH LOWER IFR CIGS/VSBYS. THERE IS A CHANCE FOR BUILD DOWN FOG THIS EVENING OR OVERNIGHT AND WIDESPREAD LIFR THROUGH THE COASTAL CORRIDOR. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT SHIFTS THROUGH THE AREA. && .MARINE... HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE WITH A MUCH LIGHTER GRADIENT BY LATER TODAY AND TONIGHT. IT WILL DIFFICULT TO TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT GIVEN THE STABLE CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW TO N LATER TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT OVER OUTER GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN ADVISORY LEVELS UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS COULD LOWER TO 1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE LAND/SEA INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS LIKELY WILL BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS. MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT. WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350- 352-354. SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374. && $$ NEAR TERM...JAQ SHORT TERM...DPB LONG TERM...DPB AVIATION... MARINE...DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
709 AM EST SUN MAR 1 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY. HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... WHILE CLOUDY/COOL AND OCCASIONALLY DAMP WEATHER WILL BE THE MAIN WEATHER FEATURES TO RING IN THE MONTH OF MARCH...THE MAIN FORECAST QUEST TODAY WILL BE FORECASTING THE DIURNAL TEMP CURVE ALONG WITH HIGH TEMPS IN A STUBBORN WEDGE PATTERN WITH THE COASTAL TROUGH UNLIKELY TO PUNCTUATE THE VERY CHILLY NEAR SHORE SHELF WATERS. EVEN THOUGH WE WILL KEEP THE WARM FRONT OFF THE COAST...QUITE A FEW OF THE MODELS RESPECT THE 14C BOUNDARY LAYER TEMPS ADVECTING OVER THE COASTAL EROSION OF THE SHALLOW COLDER AIR MASS AND SUGGEST LATE AFTERNOON TEMPS ALONG AND EAST OF U.S. 17 WILL EVENTUALLY REBOUND LATE AS SURFACE WINDS BECOME LIGHT AND PERHAPS VARIABLE. THE 13 KM RAP AND ECMWF BOTH SHOW A VERY NARROW SLOT OF NEAR 60 DEGREE SURFACE TEMPS JUST INLAND FROM THE BEACHES AROUND NORTH CHARLESTON AND WHILE NOT FAR INLAND COULD BE LOCKED IN TO LOWER TO MID 40 DEGREE AIR AT THE SURFACE. A THERMAL GRADIENT THAT SIGNIFICANT IS NOT TOTALLY OUT OF THE QUESTION BUT WE OPTED JUST TO TIGHTEN THE TEMP GRADIENT THIS AFTERNOON JUST A BIT WITH PLENTY OF MESOSCALE UNCERTAINTIES INCLUDING RAINFALL COVERAGE. RAINFALL AMOUNTS SHOULD GENERALLY BE LIGHT AND LESS THAN A QUARTER INCH FOR THE MOST PART. WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING INTO TONIGHT WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A CONCERN FOR DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING ADVECTS NE INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW CONFIDENCE AT THIS JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY FOG TO AREAS OF FOG AS A TREND. THERE WILL PROBABLY BE PATCHY DRIZZLE AROUND THE REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES AND THE SYNOPTIC OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT READINGS MANY BE STEADY OR RISING LATE. && .SHORT TERM /MONDAY THROUGH TUESDAY/... MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO LOW/MID 50S IN SOUTHEAST GEORGIA. TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY AFTERNOON/EVENING. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AT KCHS...CIGS SHOULD BECOME IFR LATER THIS MORNING AS LIGHT RAINS DEVELOP AND SPREAD BOTH INLAND AND NORTH ALONG THE COASTAL CORRIDOR. AT SAV...CIGS LIKELY ALREADY LOCKED INTO IFR OR LOWER THROUGH 12Z MONDAY. BOTH SITES CAN EXPECT PERIODS OF LIGHT RAINS AND DRIZZLE TODAY WITH PRECIP PROBABLY LASTING LONGER INTO THE AFTERNOON AT KCHS. DESPITE THE HIGH CONFIDENCE IN CIGS BELOW 1 KFT...CONFIDENCE IS NOT GOOD WITH HOW FAR DOWN CIGS WILL BUILD AND AT WHAT TIME LATER TODAY AND TONIGHT. THE SYNOPTIC PATTERN FAVORS FOG AND DRIZZLE IN THE WAKE OF LIGHT RAINS AND WE PLAYED CONTINUED DETERIORATION THIS AFTERNOON AND TONIGHT WITH LOWER IFR CIGS/VSBYS. THERE IS A CHANCE FOR BUILD DOWN FOG THIS EVENING OR OVERNIGHT AND WIDESPREAD LIFR THROUGH THE COASTAL CORRIDOR. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT SHIFTS THROUGH THE AREA. && .MARINE... HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE THROUGH THE MORNING WITH A MUCH LIGHTER GRADIENT BY LATER TODAY AND TONIGHT. IT WILL DIFFICULT TO TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT GIVEN THE STABLE CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW TO N LATER TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT OVER OUTER GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN ADVISORY LEVELS UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS COULD LOWER TO 1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE LAND/SEA INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS LIKELY WILL BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS. MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT. WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350- 352-354. SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...DPB LONG TERM...DPB AVIATION... MARINE...DPB
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
644 AM CST SUN MAR 1 2015 .UPDATE... ISSUED AT 637 AM CST SUN MAR 1 2015 OVERALL A FEW SMALL TWEAKS TO THE FORECAST WERE MADE. RADAR RETURNS SUGGEST THAT SNOW BAND COULD SHIFT A LITTLE FURTHER NORTH TODAY. AS SUCH INCREASED POPS FURTHER NORTH OF WHERE THEY WERE BEFORE. TOTAL SNOWFALL AMOUNTS REMAIN THE SAME AS EARLIER. SOME PATCHY DENSE FOG HAS DEVELOPED ACROSS THE AREA. THIS SEEMS TO BE LIMITED TO THE MISSISSIPPI RIVER VALLEY. THE FOG SHOULD BURN OFF THIS AM. OTHER THAN THAT FORECAST LOOKS TO BE ON TRACK. && .SYNOPSIS... ISSUED AT 149 AM CST SUN MAR 1 2015 VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE FOG. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 149 AM CST SUN MAR 1 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL. A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12 HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE CWA BY 18Z. AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE SHOULD END UP WITH SUN FOR THE SUNSET. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 149 AM CST SUN MAR 1 2015 THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING. SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD. IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE SHIFTS TODAY OR TONIGHT. SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO RUNOFF ISSUES ARE EXPECTED. AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY AND SATURDAY. ERVIN && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 535 AM CST SUN MAR 1 2015 TRICKY AVIATION FORECAST OVERNIGHT WILL PERSIST THRU AT LEAST MID MORNING. FG HAS DEVELOPED ACROSS THE TAF SITES. THIS HAS LEAD TO CIGS AND VSBY ISSUES ALONG WITH SOME FZFG. A CLOUD DECK HAS MOVED ACROSS THE AREA TONIGHT...UNDER IT WARMER TEMPERATURES AND LOW MVFR CIGS WERE OCCURRING. ONCE THIS DECK MOVES THROUGH THE FG WANES. CID HAS BEEN REPORTING FLURRIES THIS AM AND SHOULD NOT LAST MUCH AFTER SUNRISE. CLOUDS AND CIGS SHOULD GIVE WAY TO VFR THIS AFTERNOON AND OVERNIGHT. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...GIBBS SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...ERVIN AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
542 AM CST SUN MAR 1 2015 .SYNOPSIS... ISSUED AT 149 AM CST SUN MAR 1 2015 VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE FOG. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 149 AM CST SUN MAR 1 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL. A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12 HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE CWA BY 18Z. AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE SHOULD END UP WITH SUN FOR THE SUNSET. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 149 AM CST SUN MAR 1 2015 THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING. SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD. IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE SHIFTS TODAY OR TONIGHT. SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO RUNOFF ISSUES ARE EXPECTED. AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY AND SATURDAY. ERVIN && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 535 AM CST SUN MAR 1 2015 TRICKY AVIATION FORECAST OVERNIGHT WILL PERSIST THRU AT LEAST MID MORNING. FG HAS DEVELOPED ACROSS THE TAF SITES. THIS HAS LEAD TO CIGS AND VSBY ISSUES ALONG WITH SOME FZFG. A CLOUD DECK HAS MOVED ACROSS THE AREA TONIGHT...UNDER IT WARMER TEMPERATURES AND LOW MVFR CIGS WERE OCCURRING. ONCE THIS DECK MOVES THROUGH THE FG WANES. CID HAS BEEN REPORTING FLURRIES THIS AM AND SHOULD NOT LAST MUCH AFTER SUNRISE. CLOUDS AND CIGS SHOULD GIVE WAY TO VFR THIS AFTERNOON AND OVERNIGHT. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...ERVIN AVIATION...GIBBS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
539 AM CST Sun Mar 1 2015 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 257 AM CST SUN MAR 1 2015 Expansive upper trough axis continues to rotate off the CA coast while weaker embedded areas of vorticity were lifting north and east towards Colorado and Kansas. A stronger shortwave trough was observed shifting southeast towards the northern plains later this morning. Lows were starting out in the teens and lower 20s with scattered light snow or flurries across northeast Kansas. Main highlight of the forecast is expected snowfall from sunrise through noon today. As the upper trough dives southeast, mid level forcing is enhanced within the embedded vorticity maxima tracking east over the state. Timing of this feature and area of weak frontogenesis will place the snow band near the Interstate 70 corridor based on latest runs of the RAP and NAM or just south near the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions. Duration of light snow is quick as well with lift diminishing eastward by mid afternoon today. Main changes for the forecast package were to remove precip chances for far north central Kansas as dry air aloft increases after sunrise. Also adjusted highest chances for snowfall in the above mentioned areas where an additional one half to one inch of snow is expected. Will maintain the advisory ongoing until noon and have the following shift remove counties as the snowfall exits. With the snowfall exiting quicker and the possibility of higher cloud bases, increased highs today a few degrees in the lower to possibly middle 30s. Weak high pressure shifts southeast this evening as skies become partly to mostly cloudy. Calm winds and snow covered ground hold lows in the upper teens to lower 20s. .LONG TERM...(Monday through Saturday) Issued at 257 AM CST SUN MAR 1 2015 For Monday models prog the mid level shortwave ridge to be over the area with low level moisture remaining to the south of the forecast. So with no real forcing expected to affect the area, have a dry forecast through the day. With some cloud cover and the surface ridge possibly influencing eastern KS still, have highs only reaching the mid and upper 30s. Monday night and Tuesday appear to be the next opportunity for precip as low level return flow advects moisture north while a shortwave kicks out from the base of the mid level trough over the southwest. However chances appear to remain limited. The model consensus shows the stronger Q vector convergence and PV anomaly passing just north of the forecast area while a dry slot moves into eastern KS by Tuesday morning. With the deeper moisture over far eastern KS, have kept the higher POPs across the east during the early morning hours Tuesday as the shortwave passes by. Prior to this there could be some drizzle develop and spread northeast through the area in response to the stronger low level moisture return. Depending on temps, there could be a brief period of light freezing drizzle. However I expect this to be short lived mainly in the evening as warm air advection should cause temps to rise through the night. Therefore any accumulations should be very minor. Another arctic ridge of high pressure is set to move through the forecast area Tuesday with the GFS trending a little faster with the frontal passage. However with the dry slot in place as the front moves through and upper level forcing likely to the northeast of the forecast area, the front may move through mostly dry through the early afternoon. The forecast anticipates falling temps through the afternoon as cold air moves in behind the front. But for the most part think that any precip on Tuesday is likely to be out ahead of the front and in the form of rain. There are still weak indications of some convective instability Tuesday morning. Because of this have kept a mention for thunder across east central KS. Lows Monday night are forecast to occur early in the evening while highs Tuesday are likely to be measured late in the morning. Tuesday night may be the last chance for precip through the rest of the week. There remains some indication for some mid level frontogenesis along with enough moisture for mid level saturation. The NAM is most bullish with this idea developing several hundredths of precip. While less impressive, the ECMWF also spits out some very light precip. Because of this have continued with a slight chance for snow Tuesday night. However would not anticipate the snow amounting to very much if at all. The upper level trough axis is progged to finally move east of the forecast area Wednesday night. But with dry air moving in with the arctic airmass on Tuesday, precip chances Wednesday and Wednesday night look to be less than 20 percent due to to much dry air. Wednesday is shaping up to be another cold day with lows in the teens and highs in the 20s. Thursday through Saturday continues to look dry with moderating temps as models keep a dry northwest flow over the central plains. By Friday, highs are expected to be in the 50s. This could be a little conservative with the GFS and ECMWF showing 925 MB temps warming to between +5 and +10C. For now stayed with the model consensus and have highs in the lower 50s. && .AVIATION...(For the 12Z TAFs through 12Z Monday Morning) Issued at 527 AM CST SUN MAR 1 2015 VFR prevails at KTOP/KFOE/KMHK as scattered light snow bands develop south of KTOP/KFOE. Will occasionally see MVFR conditions within the snow bands before coming to an end by 16Z. Currently not confident enough for IFR cigs to reach KTOP/KFOE as there is some uncertainty in guidance on where heavier snow band develops. MVFR stratus develops after 16Z before incoming dry air with the high pressure scatters out lower stratus to VFR this evening. && .TOP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY until Noon CST today FOR KSZ021>024-026- 034>040-054>056-058-059. && $$ SHORT TERM...Bowen LONG TERM...Wolters AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
529 AM CST SUN MAR 1 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CST SUN MAR 1 2015 WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT DEPRESSIONS HAVE BEEN THE SMALLEST. SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT. WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 422 AM CST SUN MAR 1 2015 THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS. AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY BE IN THE FORM OF DRIZZLE. ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30. LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING BACK INTO THE 50S BY THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 528 AM CST SUN MAR 1 2015 A LOW STRATUS CLOUD DECK WILL BLANKET SOUTHWEST KANSAS THROUGH THE DAY WITH SOME IMPROVEMENT. LIFR CIGS ALONG WITH IFR VSBYS AT GARDEN CITY AND DODGE CITY SHOULD IMPROVE INTO THE IFR AND VFR CATEGORIES, RESPECTIVELY, AFTER 15Z. BY THIS AFTERNOON MVFR CIGS SHOULD PREVAIL AT GARDEN CITY AND DODGE CITY WITH VFR CIGS AT HAYS. && .PRELIMINARY POINT TEMPS/POPS... DDC 31 18 38 35 / 10 10 10 10 GCK 31 18 40 34 / 10 10 10 10 EHA 33 20 45 37 / 20 20 10 10 LBL 34 23 43 37 / 20 10 10 10 HYS 36 17 37 33 / 10 10 20 20 P28 32 20 37 34 / 20 10 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...GERARD AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
423 AM CST SUN MAR 1 2015 ...UPDATED LONG TERM DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CST SUN MAR 1 2015 WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT DEPRESSIONS HAVE BEEN THE SMALLEST. SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT. WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 422 AM CST SUN MAR 1 2015 THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS. AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY BE IN THE FORM OF DRIZZLE. ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30. LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING BACK INTO THE 50S BY THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 109 AM CST SUN MAR 1 2015 IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS, AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI RESOLUTIONS AND RAPID REFRESH MODELS INDICATE A NARROW BAND OF WHAT WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID MORNING. BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE MORE OF AN ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN MVFR STRATUS AT HYS. && .PRELIMINARY POINT TEMPS/POPS... DDC 31 18 38 35 / 10 10 10 10 GCK 31 18 40 34 / 10 10 10 10 EHA 33 20 45 37 / 20 20 10 10 LBL 34 23 43 37 / 20 10 10 10 HYS 36 17 37 33 / 10 10 20 20 P28 32 20 37 34 / 20 10 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...GERARD AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS JACKSON KY
648 AM EST SUN MAR 1 2015 .UPDATE... ISSUED AT 647 AM EST SUN MAR 1 2015 CONDITIONS ACROSS EASTERN KENTUCKY THIS MORNING FEATURED SOME SHOWERS DEVELOPING OVER FAR EASTERN KENTUCKY AS THE DEVELOPING LL JET RESULTED IN THIS DEVELOPMENT. REPORTS OVER NEAR PIKEVILLE THIS MORNING RELAYED SOME LIGHT FREEZING RAIN REPORTS WITH SOME SLICKNESS DEVELOPED ON SECONDARY ROADS. GIVEN THE INTENSITY OF THE RAIN AND THE SATURATED LOWER LEVELS IN THE FAR EAST...SENT OUT AN FREEZING RAIN ADVISORY FOR THIS. THESE DEEPER VALLEYS IN THE EAST WILL LIKELY TAKE UNTIL MID MORNING TO MIX OUT. NO REPORTS HAVE BEEN SEEN IN THE NORTHWEST AND BLUEGRASS REGION AND GIVEN THE SURGE OF WARM AIR COUPLED WITH THE CONTINUED DEW POINT DEPRESSIONS WILL CONTINUE TO HIGHLIGHT THIS AREA WITH THE SPS MENTIONING SOME LIGHT WINTRY WEATHER THIS MORNING. TEMPS SHOULD ALSO RISE QUITE QUICKLY THIS MORNING AS THE WARMER SOUTHWESTERLY AIR ADVECTS INTO THE AREA. HAVE SENT OUT A NEW ZFP WITH THE WSW HIGHLIGHTED. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 345 AM EST SUN MAR 1 2015 CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC. AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY THIS SUNDAY MORNING. HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 345 AM EST SUN MAR 1 2015 MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION LATE SATURDAY NIGHT...EARLY SUNDAY MORNING. NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST +5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE ONSET OF PRECIPITATION. OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST LOCATIONS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 647 AM EST SUN MAR 1 2015 EXPECT FIELD MIN CIGS TO DEVELOP AT JUST ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA THIS MORNING AND INTO THE DAY TODAY. EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT. AFTER 06Z TONIGHT...RAIN WILL CHANGE TO SNOW WITH SOME LOCATIONS SEEING SIGNIFICANT REDUCTION IN VIS. WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS. && .JKL WATCHES/WARNINGS/ADVISORIES... FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR KYZ088- 106>115-117>120. && $$ UPDATE...SHALLENBERGER SHORT TERM...SHALLENBERGER LONG TERM...AR AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
933 AM EST SUN MAR 1 2015 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 328 AM EST SUN MAR 1 2015 LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL WARM INTO THE MID 30S BY NEXT WEEKEND. && .UPDATE... ISSUED AT 934 AM EST SUN MAR 1 2015 I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING. THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE REST OF THE FORECAST REMAINS UNCHANGED. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 328 AM EST SUN MAR 1 2015 FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED. REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL BE A HALF INCH OR LESS. THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46 ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96. THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO DRIZZLE/FREEZING DRIZZLE. OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96 NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES. WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 328 AM EST SUN MAR 1 2015 ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING. YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE. SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE POSSIBLE ACROSS THE ENTIRE AREA. ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 656 AM EST SUN MAR 1 2015 LATEST RUC/NAM GUIDANCE SHOWS LOW LEVEL MOISTURE BECOMING WIDESPREAD BY NOON SO WILL FCST MVFR/FUEL ALTERNATE CIGS AROUND 1500 FT AT ALL THE TERMINALS FOR THIS AFTERNOON INTO THE EVENING. SOME IFR CIGS BELOW 1000 FT CANNOT BE RULED OUT EITHER WITH THE ARRIVAL OF A MILDER AIR MASS AND RISING SFC DEW POINTS OVER THE SNOW PACK. IMPROVEMENT IS EXPECTED LATE TONIGHT AS WINDS SHIFT TO THE WEST/NORTHWEST BEHIND A WEAK SFC TROUGH. DRIER AIR BEHIND THIS FEATURE SHOULD GRADUALLY LIFT CIGS TO VFR LEVELS ABOVE 3000 FT FROM WEST TO EAST AFTER 06Z. && .HYDROLOGY... ISSUED AT 1132 AM EST SAT FEB 28 2015 CONDITIONS ON AREA RIVERS AND STREAMS REMAIN STABLE. THIS IS EXPECTED TO CONTINUE TO BE THE CASE THROUGH AT LEAST THE NEXT COUPLE OF DAYS. THE PATTERN WILL BECOME MORE ACTIVE AS WE GET INTO THE SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK. THE EXTREME COLD THAT HAS BEEN ALL TOO STUBBORN WILL BEGIN TO RELEASE ITS GRIP ON THE REGION. AS A RESULT...GRADUALLY WARMER TEMPERATURES WILL MAKE THEIR WAY IN THROUGH TUESDAY. WHILE THERE IS SOME QUESTION TO THE EXTENT OF THE WARMTH IT IS STILL NOT ANTICIPATED TO CREATE MANY ISSUES AS COLD AIR QUICKLY MOVES BACK IN DURING THE MIDDLE OF THE WEEK. TOTAL PRECIPITATION AMOUNTS SHOULD HOVER AROUND A HALF INCH THROUGH THE NEXT SEVEN DAYS WITH MOST OF THIS COMING IN THE TUESDAY SYSTEM. RIVERS WILL BE MONITORED THROUGH THE NEXT SEVERAL DAYS IN THAT CASE THAT ANY VARIABILITY IS SENSED. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...WDM SYNOPSIS...04 SHORT TERM...04 LONG TERM...MEADE AVIATION...MEADE HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
907 AM EST SUN MAR 1 2015 .UPDATE... THE NORTHERN EDGE OF THE FRONTOGENETICALLY FORCED LIGHT SNOW NOW EXTENDS FROM NORTH-CENTRAL ILLINOIS INTO SRN MONROE COUNTY. THE LATEST RAP AND NAM12 SUGGEST A SLIGHT NORTHWARD SHIFT AND REINTENSIFICATION OF THE MID LEVEL FGEN BETWEEN 18Z AND 21Z. THIS SUPPORTS THE CURRENT FORECAST WHICH HOLDS FAIRLY HIGH POPS UP THROUGH THE ANN ARBOR TO DETROIT CORRIDOR AND POINTS SOUTH. THE EXPECTED BREVITY OF THE STRONGER FORCING REMAINS SUPPORTIVE OF ADDITIONAL SNOWFALL ACCUMS OF AN INCH OR LESS. SOUTHWEST FLOW OFF THE REMAINING OPEN WATERS OF LAKE MI HAS BEEN ENOUGH TO GENERATE SOME LIGHT SNOW ACROSS WEST CENTRAL LOWER MI THIS MORNING. A VEERING OF THE LOW FLOW TOWARD THE WEST HAS BROUGHT SOME OF THIS LOW LEVEL MOISTURE INTO THE TRI CITIES REGION. CONDITIONS APPEAR TO BE SUPERSATURATED WITH RESPECT TO ICE WITHIN THESE CLOUDS WHICH IS LIKELY CAUSING SOME DECENT SNOWFLAKE SIZE /ALSO SUGGESTED BY SOME OF THE VSBY REDUCTIONS/. THE LATEST RADAR TRENDS SHOW A WEAKENING OF RETURNS. DIURNAL MIXING INTO SOME DRIER AIR MAY ALSO ERODE SOME OF THIS LOW LEVEL MOISTURE. IN LIGHT OF CURRENT OBS...AN UPDATE WILL HAVE TO BE ISSUED TO AT LEAST CARRY SOME FLURRIES ACROSS THE SAGINAW VALLEY TODAY. && .AVIATION...ISSUED 554 AM EST SUN MAR 1 2015 THE WIDESPREAD SHIELD OF LIGHT SNOW HAS STRIPPED OUT OF SOUTHEASTERN MICHIGAN THIS MORNING AS FAVORABLE UPPER LEVEL JET FORCING LIFTS OFF TO THE NORTHEAST. BACKED OFF A FAIR AMOUNT ON THE MENTION FOR ADDITIONAL SNOWFALL IN THE TAFS. THERE IS A HIGH AMOUNT OF UNCERTAINTY AS WHETHER OR NOT PRECIPITATION THIS MORNING WILL BE ABLE TO CLIP DTW. DID LEAVE A PERIOD OF IFR LIGHT SNOW THIS AFTERNOON AS ANOTHER BOUT OF FORCING IS FORECASTED TO SLIDE OVER SOUTHEASTERN MICHIGAN. FOR DTW...LIGHT SNOW IS EXPECTED TO REFOCUS SOUTH OF THE DTW TERMINAL THIS MORNING. IT IS TOUGH CALL ON WHETHER OR NOT A LONG DURATION OF SNOW WILL IMPACT THE TERMINAL. EXPECTATIONS ARE THAT LIGHT SNOW WILL FILL BACK IN FOR THE 19-23Z TIMEFRAME. SNOWFALL ACCUMULATIONS WILL REMAIN RELATIVELY LIGHT...WITH PERHAPS AN INCH FALLING DURING THE AFTERNOON. //DTW THRESHOLD PROBABILITIES... * HIGH IN CEILINGS BELOW 5000 FT THROUGH SUNDAY. * HIGH IN PTYPE AS SNOW TONIGHT AND SUNDAY. && .PREV DISCUSSION...ISSUED 357 AM EST SUN MAR 1 2015 SHORT TERM...TODAY AND TONIGHT SYNOPTIC SCALE ASCENT ANCHORED UNDER THE LEFT EXIT QUADRANT OF A POWERFUL ZONAL JET AXIS AND WEAK SYSTEM RELATIVE ISENTROPIC ASCENT ARE THE MECHANISMS RESPONSIBLE FOR THE BROAD FOOTPRINT OF LIGHT SNOW ACROSS THE REGION. THE LEAD EDGE OF THE PRECIPITATION WAS ABLE TO LIFT NORTHWARD THROUGH THE DETROIT METRO AREA PRIOR TO 6Z...TIMING WELL WITH A COMPACT 850MB TEMPERATURE GRADIENT. NWP DATA SUPPORTS THIS STEEPENED FRONTAL STRUCTURE TO CONTINUE TO LIFT NORTHEASTWARD AWAY FROM THE CWA...MAKING IT AS FAR NORTHWARD AS CENTRAL LAKE HURON AND SOUTHERN GEORGIAN BAY BY 12Z. AN ADDITIONAL STEEPEND FRONTAL STRUCTURE RESIDES TO THE SOUTH OF THE STATE...NOW OVER CENTRAL SECTIONS OF INDIANA AND OHIO. THIS FEATURE IS RESPONSIBLE FOR THE HIGHER Z RETURNS AND LOWER VSBYS IN SURFACE OBSERVATIONS. MODELS SUPPORT THIS BAROCLINIC ZONE TO REMAIN SOUTH OF THE AREA THROUGH THE DURATION OF THE EVENT. WITH THIS IN MIND...EXPECTATIONS ARE FOR A STATUS QUO TO SNOWFALL RATES THROUGH 12Z WITH VERY LIGHT SNOW ACCUMULATIONS THIS MORNING. WITH THE UPPER LEVEL JET FORCING AND LEAD MOISTURE ADVECTION VACATING THE PREMISES...FORCING WILL THEN DISTILL DOWN TO WEAK ISENTROPIC ASCENT. WHILE PERSISTENT...THERE IS SERIOUS QUESTION ON WHETHER OR NOT THIS UPGLIDE WILL BE SUFFICENT IN CONTINUING TO GENERATE MEASURABLE PRECIPATION. CURRENT RADAR MOSAIC DOES SHOW A DEFINITIVE BACK EDGE OF THE PRECIPATION SHIELD...WITH DRY AIR ALREADY ADVANCING THROUGH CHICAGOLAND AND INTO FAR SOUTHWESTERN LOWER MICHIGAN. VARIOUS SOLUTIONS THEN SUGGEST IT WILL REQUIRE THE AGEOSTROPHIC RESPONSE TO A POSITIVE D(MAG)/DT INCREASE OF THE UPPER LEVEL JET MAX TO ALLOW PRECIPATION TO FILL BACK IN ACROSS FAR SOUTHERN SECTIONS OF THE CWA FOR THE AFTERNOON. THIS IS EXPECTED TO OCCUR BETWEEN 19-00Z. GIVEN THE TRENDS IN NUMERICAL OUTPUT IN ADDITION TO THE RADAR DATA...WAS FAIRLY AGGRESSIVE IN LOWERING POPS AND AMOUNTS FOR AREAS NORTH OF DETROIT. IN SUM TOTAL...SNOWFALL ACCUMULATIONS OF 1 TO 2 INCHES WILL BE POSSIBLE FROM DETROIT SOUTHWARD WITH AN INCH POSSIBLE BETWEEN THE M 59 AND I 94 CORRIDORS. THE MAIN MIDLEVEL TROUGH AXIS AND NORTHERN STREAM WAVE WILL CATCH UP TO LOWER MICHIGAN TONIGHT PASSING THROUGH THE CWA AFTER 6Z. SHALLOW...LOWER TROPOSPHERIC COLD AIR ADVECTION IS FORECASTED TO STEEPEN LAPSE RATES IN THE 1.5 TO 5.5 KFT AGL LAYER. THE UNSTABLE PROFILE IN COMBINATION WITH PROGGED SATURATION WRT ICE AND CYCLONIC VORTICITY ADVECTION SUPPORTS HYDROMETEOR PRODUCTION THE LATTER HALF OF THE NIGHT. TOTAL LACK OF QPF SUPPORTS NOTHING MORE THAN A MENTION OF FLURRIES AT THIS TIME. LONG TERM... MODEL TRENDS EXPLORED DURING THE 12Z CYCLE LARGELY HOLD TRUE FOR THE 00Z RUNS WITH A BIT LESS DISPARITY IN SOLUTIONS. ESSENTIALLY...THE BROAD AND SOMEWHAT FLAT SOUTHERN EDGE OF THE EXISTING NOAM UPPER TROUGH WILL REMAIN IN PLACE OVER THE CONUS AS A POTENT NORTHERN STREAM SHORTWAVE NOW EXITING ALASKA TAKES A TRACK SOUTHEASTWARD THROUGH THE PRAIRIE PROVINCES AND THEN EAST ALONG THE SOUTHERN EDGE OF HUDSON BAY DURING THE FIRST PART OF THIS WEEK. THIS WILL STEER SOUTHERN STREAM ENERGY INTO THE AREA ON A RATHER FLAT TRAJECTORY. IN THE MEANTIME...WHILE THE ARCTIC AIRMASS IN PLACE TO OUR NORTH AS ERODED TO SOME EXTENT DURING THE PAST DAY OR TWO...IT STILL REMAINS EXPANSIVE ENOUGH TO MAINTAIN A TIGHT TEMPERATURE GRADIENT ACROSS THE GREAT LAKES. BETWEEN THESE TWO FACTORS...CHANCES ARE THAT COLD AIR WILL BE DIFFICULT TO DISPLACE OVER THE AREA. THIS SHOULD LEAD TO A FAIR AMOUNT OF THE PRECIPITATION FROM THIS SYSTEM FALLING AS SNOW. EVEN NAM12/GFS NOW SUPPORT A BASICALLY ALL SNOW EVENT FOR THE FAR NORTHERN CWA. THE MAIN QUESTION WILL BE THE TIMING AND PLACEMENT OF A CHANGEOVER TO SLEET/FREEZING RAIN AND THEN RAIN IN SOME LOCATIONS BY AFTERNOON AS THE SURFACE LOW REFLECTION OF THIS SYSTEM CROSSES THE AREA. WILL ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST AS MODELS DO NOT SUPPORT A STRONG SHIFT EITHER NORTH OF SOUTH IN THE PRECIPITATION TYPE FORECAST. GENERALLY...AREAS FROM I-69 NORTH ARE EXPECTED TO REMAIN LARGELY SNOW OR SLEET THROUGHOUT THE EVENT. FOR THE REST OF THE FORECAST AREA...PRECIPITATION WILL START AS SNOW TUESDAY MORNING WITH A GRADUAL CHANGEOVER TO SLEET/FREEZING RAIN FROM SOUTH TO NORTH AS SOME MILDER AIR WORKS INTO LOWER MICHIGAN AND THEN A CHANGE TO RAIN THROUGH THE SOUTHERN THIRD TO HALF OF THE AREA AS SURFACE AND BOUNDARY LAYER TEMPERATURES CLIMB INTO THE MID/UPPER 30S. OVERALL PRECIPITATION INTENSITY FORECASTS FROM THE MODELS SUGGEST ONLY LIGHT TO MODERATE PERIODS OVER A 8-10 HOUR PERIOD DURING THE DAY TUESDAY SO WHILE IT WILL MOST LIKELY BECOME RATHER MESSY IN TERMS OF TRAVEL THIS IS NOT A PARTICULARLY POWERFUL WINTER STORM. AS FOR TEMPERATURES...RELATIVELY MILD READINGS AS COMPARED TO THE PAST FEW WEEKS CAN BE EXPECTED MONDAY INTO TUESDAY. STILL WITH AVERAGE HIGHS IN THE UPPER 30S/LOWER 40S FOR EARLY MARCH THE AREA WILL REMAIN AOB AVERAGE EVEN DURING THIS PERIOD. MUCH COLDER AIR WILL THEN DUMP INTO THE AREA BEHIND THIS SYSTEM DURING THE LAST PART OF THE WEEK AS ANOTHER ARCTIC HIGH PRESSURE SYSTEM BUILDS SOUTHEAST THROUGH THE EASTERN CONUS WITHIN AMPLIFYING UPPER TROUGHING PATTERN THAT DEVELOPS AS ADDITIONAL NORTHERN STREAM SHORTWAVE ENERGY DIGS INTO AREA BEHIND THE EXITING STORM SYSTEM. AS THIS TROUGH PROGRESSES EASTWARD BY THE END OF THE FORECAST PERIOD...A MODERATION IS EXPECTED INTO NEXT WEEKEND WITH TEMPERATURES AT LEAST CLIMBING BACK INTO THE 30S. MARINE... A WEAK TO MODERATE SURFACE PRESSURE GRADIENT WILL MAINTAIN WINDS BELOW 20 KNOTS THROUGH SUNDAY NIGHT. A COLD FRONT WILL GRAZE THE NORTHERN PORTIONS OF LAKE HURON MONDAY AND BRING A FRESH NORTHWEST BREEZE WITH GUSTS TO 30 KNOTS POSSIBLE AS COLD AND MARGINALLY UNSTABLE CONDITIONS DEVELOP. HIGH PRESSURE WILL THEN BUILD INTO THE AREA FROM THE WEST WITH NEARLY CALM CONDITIONS TAKING HOLD MONDAY NIGHT BEFORE MODERATE SOUTHERLY WINDS EXPAND INTO THE REGION IN ADVANCE OF THE NEXT STORM SYSTEM DUE INTO THE AREA BY TUESDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......SC AVIATION.....CB SHORT TERM...CB LONG TERM....DG MARINE.......DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 AM EST SUN MAR 1 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM EST SUN MAR 1 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS. MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN. MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE DISTURBANCES. TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE 25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL. TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85 THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN THAT AREA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 416 AM EST SUN MAR 1 2015 MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY. MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION. ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE WARMER THAN THE LAST SEVERAL WEEKS. MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND 0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND 2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA. WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE. KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P. FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30 FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS. THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT SNOW TO THE AREA ONCE AGAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 644 AM EST SUN MAR 1 2015 A SW FLOW IN ADVANCE OF AN APRCHG LO PRES TROF THAT IS TAPPING A BIT MORE LLVL MSTR WL BRING A PERIOD OF MVFR CIGS THIS MRNG INTO THE AFTN BEFORE THE ARRIVAL OF DRIER AIR IN THE WAKE OF THE TROF PASSAGE RETURNS CONDITIONS TO VFR IN THE AFTN. AS COLDER AIR RETURNS TNGT BEHIND A REINFORCING COLD FROPA...MVFR CIGS AND PERHAPS SOME -SHSN WL RETURN TO THE CMX AND IWD LOCATIONS THAT EXPERIENCE UPSLOPE MOISTENING WITH THE EXPECTED GUSTY WNW FLOW. DOWNSLOPE NATURE OF THIS FLOW INTO SAW SHOULD MAINTAIN VFR CONDITIONS THERE. ENUF DRY AIR AHEAD OF A HI PRES RDG WL LIKELY BRING CLRG/VFR WX TO IWD LATE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 AM EST SUN MAR 1 2015 NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
617 AM CST SUN MAR 1 2015 .SYNOPSIS... ISSUED AT 347 AM CST SUN MAR 1 2015 AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES UNLIKELY. TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS. WINDS WERE LIGHT AND VARIABLE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CST SUN MAR 1 2015 FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32 AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO 10 MPH SOUTH. FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3 WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA. WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 347 AM CST SUN MAR 1 2015 12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY. THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE 285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1 TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF 5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE 0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS. BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF THE WORK WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 615 AM CST SUN MAR 1 2015 VFR CONDITIONS ARE FORECAST FOR THE KLBF AND KVTN TERMINALS TODAY AND TONIGHT. && .HYDROLOGY... ISSUED AT 347 AM CST SUN MAR 1 2015 THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROBERG SHORT TERM...ROBERG LONG TERM...JACOBS AVIATION...ROBERG HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1050 AM EST SUN MAR 1 2015 .SYNOPSIS... WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... REGIONAL RADAR MOSAIC SHOWING VARIABLE RETURN INTENSITIES WITHIN THE BROAD...MDTLY STG WEST-SWRLY WARM ADVECTION ALOFT. VSBYS IN THE 1.5-3SM RANGE ACROSS THE SUSQ VALLEY AT 14Z...DECREASE WWD TO BETWEEN 3/4-1SM ACROSS THE SWRN THIRD OF THE STATE. EXPECT STEADY AND SLIGHTLY VARYING SNOWFALL INTENSITY TO CONTINUE THROUGH THE REST OF THIS MORNING /AND MUCH OF THE AFTERNOON/ AS THE MEAN 925-850 MB ZERO DEG C WET BULB ISOTHERM IS STILL WELL TO THE SOUTH OF THE MASON DIXON LINE AND WILL ONLY BE DRIFTING SLOWLY TO THE NORTH DURING THE MIDDAY AND EARLY AFTERNOON HOURS. WILL CONTINUE TO MODIFY SNOW ACCUM GRIDS WITH AN INJECTION OF BLENDED NEW 09Z/12Z ENS AND HIGH RES MODEL GUIDANCE...BUT DON/T EXPECT ANY EYE-OPENING CHANGES WITH OUR CURRENT FCST STORM TOTAL SNOWFALL IN MOST LOCATIONS. TOTAL SNOWFALL MAY BE ADJUSTED UPWARD BY AN INCH OR TWO ACROSS PORTIONS OF THE CENTRAL RIDGE AND VALLEY REGION...BUT VALUES WILL STILL RESIDE WELL WITHIN THE ADVISORY CATEGORY. THE BIGGEST CONCERN STILL SURROUNDS THE TIMING OF SNOW MIX/CHANGEOVER TO FZRA ACROSS THE SCENT AND LOWER SUSQ VALLEY REGIONS LATE THIS AFTERNOON AND EVENING...AND ASSOCIATED QPF AMOUNTS. 12Z RAP FOR KMDT SHOWS A BRIEF CHANGE TO SLEET AROUND 18-19Z THEN MAINLY LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. 06Z NAM IS VERY SIMILAR IN TIMING WITH THE CHANGEOVER ACROSS THE LOWER SUSQ VALLEY AND CONTAINS AROUND OR JUST UNDER 0.25 INCH FALLING AS FREEZING RAIN LATER TODAY AT KMDT AND KLNS. WILL CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO SIGNIFICANTLY DEVIATE. WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE STORM WARNINGS AT THIS TIME. GOOD CONSISTENCY OF THE PAST SEVERAL MODEL RUNS AND ENSEMBLES WITH RESPECT TO PTYPE INDICATES THAT THE BULK OF THIS WINTRY EVENT WILL FALL AS SNOW TO THE NORTH OF THE RT22/322 CORRIDOR IN CENTRAL PENN. TEMPS WILL BE NEARLY STEADY IN THE TEENS TO AROUND 20F THROUGH 13Z...THEN SLOWLY RISE TO A LATE DAY HIGH IN THE UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID 30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY. WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... THE VERY WEAK LOW DEVELOPING ON THE DELMARVA AND RUSHING OFF SHORE LATE TODAY INTO TONIGHT WILL ENHANCE THE MIXED PRECIP OR FREEZING RAIN RATES OVER THE SERN COS FOR UP TO SEVERAL HOURS /BETWEEN 19Z-00Z/. VERY INTERESTING PART OF THE FORECAST WILL BE THE SNOW TYPE. THERE IS A REALLY GOOD SIGNAL IN THE UPPER PART OF THE CLOUDS IN THE MIDDLE OF THE DAY WHERE THE BEST VERTICAL MOTION IS SQUARELY IN THE PREFERRED DENDRITIC GROWTH ZONE AROUND -15C. THEN...IT FALLS THROUGH A HIGHLY MOIST/SATURATED COLUMN AND GETS ONLY CLOSE TO MELTING INMOST PLACE. THIS COULD MAKE SOME GIANT BUT WET FLAKES. THUS...A HIGH WATER CONTENT AND HEAVIER SNOW. THE SNOW PHYSICS...THE WINDS ALOFT AND SFC TEMPS ALL WILL PULL THE SNOW ACCUMS ONE WAY AND ANOTHER. HOWEVER...TEMP PROFILES LOOK PRETTY SIMILAR TO PAST WEEKENDS VERY SIMILAR STORM. MANY SIMILARITIES EXIST WITH THAT PREV STORM...BUT THE TEMPS APPEAR JUST SLIGHTLY COLDER. THINKING THAT WE WILL GET BIGGER FLAKES BUT END UP WITH THE SAME WATER CONTENT AND SLIGHTLY HIGHER SNOW ACCUMS OVER MOST OF THE AREA. GREATEST FCST BUST POTENTIAL APPEARS TO EXIST IN THE SE...WHERE IF THERE ENDS UP BEING NO TURNOVER TO MIXED PRECIP/ZR...IT WILL MEAN THAT THE 0.6 INCHES OF WATER PROGGED THERE MAY NUDGE THEM NEAR WARNING AMOUNTS. EVEN THIS SEEMS VERY SIMILAR TO THE FEB 21ST. PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING THROUGH VERY EARLY MORNING HOURS OF MONDAY. LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE NORTH TO 30F IN ACROSS THE SOUTH. BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL THROUGHOUT THE DAY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO. SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO RAIN TUESDAY NIGHT INTO WEDNESDAY. RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF THE TRAILING COLD FRONT EARLY WEDNESDAY. EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY OR ANOTHER FOR A SOLUTION. BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF FEBRUARY BEHIND. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... STRONGEST RADAR RETURNS ASSOCIATED WITH 0.5-1.5SM SNOW BLANKET THE REGION MAINLY TO THE SOUTH OF INTERSTATE 80 AT 1530Z. EXPECT THIS AREAL DISTRIBUTION OF THE SNOWFALL INTENSITY TO CONTINUE THIS AFTERNOON AS WEAK LOW PRESSURE FROM THE OHIO VALLEY TRACKS EASTWARD INTO THE LAUREL HIGHLANDS AND SECONDARY WEAK LOW PRES FORMS NEAR THE DELMARVA COAST. ACROSS THE NRN MTNS OF PA VSBYS SHOULD AVERAGE NEARLY 1SM HIGHER IN THE LIGHT SNOW. GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS AFT AND THIS EVENING. VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING TO MVFR IN THE CENTRAL AND EAST LATE. CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW SHOWERS. BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY. OUTLOOK... MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS. TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE. WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. && .CLIMATE... THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE COLDEST FEBRUARY ON RECORD. MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9. THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT 21.4 BOTH SET IN 1934. THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT IPT...AND FOURTH COLDEST EVER AT MDT. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027- 028-037-041-042-045-046-049>053-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006- 010>012-017-018-024-033. WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR PAZ025-026-034>036. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LA CORTE/LAMBERT AVIATION...LAMBERT/RXR CLIMATE...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
954 AM EST SUN MAR 1 2015 .SYNOPSIS... WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... REGIONAL RADAR MOSAIC SHOWING VARIABLE RETURN INTENSITIES WITHIN THE BROAD...MDTLY STG WEST-SWRLY WARM ADVECTION ALOFT. VSBYS IN THE 1.5-3SM RANGE ACROSS THE SUSQ VALLEY AT 14Z...DECREASE WWD TO BETWEEN 3/4-1SM ACROSS THE SWRN THIRD OF THE STATE. EXPECT STEADY AND SLIGHTLY VARYING SNOWFALL INTENSITY TO CONTINUE THROUGH THE REST OF THIS MORNING /AND MUCH OF THE AFTERNOON/ AS THE MEAN 925-850 MB ZERO DEG C WET BULB ISOTHERM IS STILL WELL TO THE SOUTH OF THE MASON DIXON LINE AND WILL ONLY BE DRIFTING SLOWLY TO THE NORTH DURING THE MIDDAY AND EARLY AFTERNOON HOURS. WILL CONTINUE TO MODIFY SNOW ACCUM GRIDS WITH AN INJECTION OF BLENDED NEW 09Z/12Z ENS AND HIGH RES MODEL GUIDANCE...BUT DON/T EXPECT ANY EYE-OPENING CHANGES WITH OUR CURRENT FCST STORM TOTAL SNOWFALL IN MOST LOCATIONS. TOTAL SNOWFALL MAY BE ADJUSTED UPWARD BY AN INCH OR TWO ACROSS PORTIONS OF THE CENTRAL RIDGE AND VALLEY REGION...BUT VALUES WILL STILL RESIDE WEEL WITHIN THE ADVISORY CATEGORY. THE BIGGEST CONCERN STILL SURROUNDS THE TIMING OF SNOW MIX/CHANGEOVER TO FZRA ACROSS THE SCENT AND LOWER SUSQ VALLEY REGIONS LATE THIS AFTERNOON AND EVENING...AND ASSOCIATED QPF AMOUNTS. 12Z RAP FOR KMDT SHOWS A BRIEF CHANGE TO SLEET AROUND 18-19Z THEN MAINLY LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. 06Z NAM IS VERY SIMILAR IN TIMING WITH THE CHANGEOVER ACROSS THE LOWER SUSQ VALLEY AND CONTAINS AROUND OR JUST UNDER 0.25 INCH FALLING AS FREEZING RAIN LATER TODAY AT KMDT AND KLNS. WILL CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO SIGNIFICANTLY DEVIATE. WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE STORM WARNINGS AT THIS TIME. GOOD CONSISTENCY OF THE PAST SEVERAL MODEL RUNS AND ENSEMBLES WITH RESPECT TO PTYPE INDICATES THAT THE BULK OF THIS WINTRY EVENT WILL FALL AS SNOW TO THE NORTH OF THE RT22/322 CORRIDOR IN CENTRAL PENN. TEMPS WILL BE NEARLY STEADY IN THE TEENS TO AROUND 20F THROUGH 13Z...THEN SLOWLY RISE TO A LATE DAY HIGH IN THE UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID 30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY. WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... THE VERY WEAK LOW DEVELOPING ON THE DELMARVA AND RUSHING OFF SHORE LATE TODAY INTO TONIGHT WILL ENHANCE THE MIXED PRECIP OR FREEZING RAIN RATES OVER THE SERN COS FOR UP TO SEVERAL HOURS /BETWEEN 19Z-00Z/. VERY INTERESTING PART OF THE FORECAST WILL BE THE SNOW TYPE. THERE IS A REALLY GOOD SIGNAL IN THE UPPER PART OF THE CLOUDS IN THE MIDDLE OF THE DAY WHERE THE BEST VERTICAL MOTION IS SQUARELY IN THE PREFERRED DENDRITIC GROWTH ZONE AROUND -15C. THEN...IT FALLS THROUGH A HIGHLY MOIST/SATURATED COLUMN AND GETS ONLY CLOSE TO MELTING INMOST PLACE. THIS COULD MAKE SOME GIANT BUT WET FLAKES. THUS...A HIGH WATER CONTENT AND HEAVIER SNOW. THE SNOW PHYSICS...THE WINDS ALOFT AND SFC TEMPS ALL WILL PULL THE SNOW ACCUMS ONE WAY AND ANOTHER. HOWEVER...TEMP PROFILES LOOK PRETTY SIMILAR TO PAST WEEKENDS VERY SIMILAR STORM. MANY SIMILARITIES EXIST WITH THAT PREV STORM...BUT THE TEMPS APPEAR JUST SLIGHTLY COLDER. THINKING THAT WE WILL GET BIGGER FLAKES BUT END UP WITH THE SAME WATER CONTENT AND SLIGHTLY HIGHER SNOW ACCUMS OVER MOST OF THE AREA. GREATEST FCST BUST POTENTIAL APPEARS TO EXIST IN THE SE...WHERE IF THERE ENDS UP BEING NO TURNOVER TO MIXED PRECIP/ZR...IT WILL MEAN THAT THE 0.6 INCHES OF WATER PROGGED THERE MAY NUDGE THEM NEAR WARNING AMOUNTS. EVEN THIS SEEMS VERY SIMILAR TO THE FEB 21ST. PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING THROUGH VERY EARLY MORNING HOURS OF MONDAY. LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE NORTH TO 30F IN ACROSS THE SOUTH. BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL THROUGHOUT THE DAY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO. SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO RAIN TUESDAY NIGHT INTO WEDNESDAY. RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF THE TRAILING COLD FRONT EARLY WEDNESDAY. EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY OR ANOTHER FOR A SOLUTION. BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF FEBRUARY BEHIND. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... THIS MID MORNING..THE LEADING EDGE OF THE LARGE SHIELD OF LIGHT SNOW HAS OVERSPREAD CENTRAL PA...REDUCING VSBYS TO 2 MILES OR LESS /IFR CONDITIONS/ ACROSS A WIDESPREAD AREA. GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED ALL DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 13Z...BUT WILL ALSO DROP AS DAY WEARS ON. STILL THE THREAT OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS AFT AND THIS EVENING. VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING TO MVFR IN THE CENTRAL AND EAST LATE. CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW SHOWERS. BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY. OUTLOOK... MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS. TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE. WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. && .CLIMATE... THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE COLDEST FEBRUARY ON RECORD. MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9. THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT 21.4 BOTH SET IN 1934. THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT IPT...AND FOURTH COLDEST EVER AT MDT. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027- 028-037-041-042-045-046-049>053-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006- 010>012-017-018-024-033. WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR PAZ025-026-034>036. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LA CORTE/LAMBERT AVIATION...RXR CLIMATE...LAMBERT
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1026 AM EST SUN MAR 1 2015 .DISCUSSION... MOISTURE ADVECTION AND DOWNSLOPE WINDS ARE DUELING FOR TERRITORY ACROSS NE TN AND THE FOOTHILLS THIS MORNING. THE MOISTURE ADVECTION APPEARS TO HAVE THE UPPER HAND AS CLOUDS ARE SLOWLY ADVANCING EASTWARD...AND THE RAP SHOWS 925 MB WINDS THAT ARE ONLY 15 KTS. HOWEVER...IT IS ENOUGH TO PROVIDE PLENTY OF SUNSHINE IN THE LEE OF THE MOUNTAINS...ALLOW TEMPS TO REACH THE LOWER 50S ALREADY. WILL UPDATE TO ADJUST TEMPERATUERS IN THIS AREA. UPSTREAM RADAR SHOWS QUITE A BIT OF RAIN OVER MIDDLE TN...AND WHILE IT APPEARS THAT MUCH OF IT IS NOT REACHING THE GROUND AT THE MOMENT...IT SHOULD MOVE INTO OUR PLATEAU COUNTIES THIS AFTERNOON TO PRODUCE SOME LIGHT QPF. WILL UPDATE POPS TO RAISE POPS IN THIS AREA FOR THE AFTERNOON...AND LOWER POPS IN EASTERN SECTIONS. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DGS
AREA FORECAST DISCUSSION...AMENDED AVIATION SECTION.
NWS CHEYENNE WY
524 AM MST SUN MAR 1 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 400 AM MST SUN MAR 1 2015 LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE SINGLE DIGITS AND TEENS WITH LIGHT WINDS. FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING AT THE 12Z/18Z MODEL GUIDANCE. HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS. MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE 30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE WAKE OF THE COLD FRONTAL PASSAGE. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 AM MST SUN MAR 1 2015 THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM. IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF 60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH OF THAT TIME PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 515 AM MST SUN MAR 1 2015 SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH GENERALLY VFR CONDITIONS PREVAILING. SPORADIC MVFR CIGS ARE POSSIBLE THROUGH THE MORNING BENEATH A STRATUS DECK AROUND 5K FEET AGL. A COLD FRONT WILL SWEEP ACROSS THE AREA TONIGHT...BRINGING ANOTHER ROUND OF SNOW TO AREAS ALONG AND SOUTH OF I80. MVFR TO IFR CIGS/VSBYS ARE LIKELY AFTER 06Z MON. WINDS WILL GENERALLY BE LIGHT THROUGH THE TAF PERIOD. && .FIRE WEATHER... ISSUED AT 321 AM MST SUN MAR 1 2015 A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE. A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT FOR WYZ111>114. NE...NONE. && $$ SHORT TERM...MAJ LONG TERM...CLH AVIATION...CLH FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
430 AM MST SUN MAR 1 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 400 AM MST SUN MAR 1 2015 LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE SINGLE DIGITS AND TEENS WITH LIGHT WINDS. FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING AT THE 12Z/18Z MODEL GUIDANCE. HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS. MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE 30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE WAKE OF THE COLD FRONTAL PASSAGE. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 AM MST SUN MAR 1 2015 THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM. IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF 60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH OF THAT TIME PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 425 AM MST SUN MAR 1 2015 SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH VFR CONDITIONS PREVAILING. A COLD FRONT WILL SWEEP ACROSS THE AREA THIS EVENING AND OVERNIGHT...BRINGING ANOTHER ROUND OF SNOW TO AREAS ALONG AND SOUTH OF INTERSTATE 80. MVFR TO IFR CIGS/VSBYS ARE LIKELY AFTER 06Z MON. WINDS WILL GENERALLY BE LIGHT THROUGH THE TAF PERIOD. && .FIRE WEATHER... ISSUED AT 321 AM MST SUN MAR 1 2015 A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE. A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT FOR WYZ111>114. NE...NONE. && $$ SHORT TERM...MAJ LONG TERM...CLH AVIATION...CLH FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
406 AM MST SUN MAR 1 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 400 AM MST SUN MAR 1 2015 LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE SINGLE DIGITS AND TEENS WITH LIGHT WINDS. FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING AT THE 12Z/18Z MODEL GUIDANCE. HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS. MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE 30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE WAKE OF THE COLD FRONTAL PASSAGE. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 AM MST SUN MAR 1 2015 THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM. IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF 60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH OF THAT TIME PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 952 PM MST SAT FEB 28 2015 TOUGH FORECAST FOR OUR SOUTHEAST WYOMING AIRPORTS. RADAR SHOWING AREA OF SNOW FILLING IN FROM KCYS TO KLAR...BUT IT IS NOT TOO HEAVY AND BARELY RESTRICTING VISIBILITIES. GOING TO HOLD OFF LOWERING CONDITIONS UNTIL AFTER 12Z AND CONFINE LOWER CONDITIONS TO KLAR. && .FIRE WEATHER... ISSUED AT 321 AM MST SUN MAR 1 2015 A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE. A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT FOR WYZ111>114. NE...NONE. && $$ SHORT TERM...MAJ LONG TERM...CLH AVIATION...GCC FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
926 AM PST SUN MAR 1 2015 .SYNOPSIS...MOSTLY SUNNY TODAY EXCEPT SOME SHOWERS OVER THE HILLS OF MONTEREY AND SAN BENITO COUNTY THIS AFTERNOON. ANOTHER WEAK WEATHER SYSTEM WILL DROP DOWN THE COAST BRINGING SOME SCATTERED SHOWERS TO THE REGION MONDAY AFTERNOON...MAINLY OVER THE HILLS AND ALONG THE COAST. HIGH PRESSURE BUILDS TUESDAY THROUGH NEXT WEEKEND WITH A RETURN TO DRY CONDITIONS...MOSTLY CLEAR SKIES AND ABOVE NORMAL DAYTIME TEMPERATURES. && .DISCUSSION...AS OF 8:45 AM PST SUNDAY...SKIES ARE MOSTLY SUNNY THIS MORNING ACROSS THE BAY AREA AS THE CALENDAR HAS TURNED TO MARCH. YESTERDAYS UPPER LOW IS NOW WEST OF POINT CONCEPTION WITH SOME COLD AIR ALOFT AND INSTABILITY OVER THE CENTRAL COAST AND SOUTHERN CALIFORNIA. THE BAY AREA WILL SEE SKIES TURN PARTY CLOUDY THIS AFTERNOON WITH SOME CLOUDS OVER THE HILLS AND AFTERNOON HIGHS IN THE MID 60S. MONTEREY AND SAN BENITO COUNTY WILL STAY CLOSE ENOUGH TO THE UPPER LOW TO KEEP AFTERNOON SHOWERS AND EVEN AN ISOLATED T-STORM IN THE FORECAST. THE 12Z NAM AND LATEST RUNS OF THE RAP AND HRRR MODELS ALL GENERATE SOME CONVECTIVE SHOWERS OVER THE HILLS OF SAN BENITO AND MONTEREY COUNTY AND CURRENT FORECAST HAS THAT COVERED. WILL HAVE TO MONITOR FOR SOME SMALL HAIL AND LIGHTNING THREAT. SPC HAS THIS COVERED WITH THE REGION IN THE GENERAL T-STORM OUTLOOK TODAY AS WELL. SKIES WILL TURN MOSTLY CLEAR OVERNIGHT...SETTING THE STAGE FOR A FAIRLY CHILLY NIGHT AS WINDS BECOME LIGHT WITH A COOL AND DRY AIRMASS OVER THE REGION. NEXT SYSTEM WILL QUICKLY DROP DOWN THE COAST ON MONDAY BUT MODELS ARE IN SOLID AGREEMENT SHOWING THE MAIN RAIN SHIELD STAYING OFFSHORE. THE SYSTEM IS DROPPING FROM THE NORTH WITH A FAIRLY COLD AIRMASS ALOFT. THUS THERE WILL BE ENOUGH INSTABILITY TO PRODUCE SOME SCATTERED SHOWERS MONDAY AFTERNOON...MAINLY OVER THE HILLS ONCE AGAIN. ACTIVITY WILL BE LESS WIDESPREAD THAN WHAT WAS OBSERVED SATURDAY AND EXPECT MOST AREAS TO STAY DRY. IN FACT MODELS ARE SHOWING THE BEST CHANCES ONCE AGAIN OVER THE HIGHER TERRAIN OF MONTEREY AND SAN BENITO WITH THE TRAJECTORY OF THE LOW. ANY SHOWERS END AS THE SUN SETS MONDAY EVENING. THEN HIGH PRESSURE BUILDS TUESDAY THROUGH NEXT WEEKEND WITH A WARMING AND DRYING TREND. UNFORTUNATELY IT LOOKS LIKE ANY RAIN CHANCES DISAPPEAR UNTIL MIDDLE OF THE MONTH. && .AVIATION...AS OF 9:25 AM PST SUNDAY...VFR CONDITIONS AT ALL TERMINALS THIS MORNING AND THIS WILL BE THE CASE FOR MUCH OF THE DAY. SOME OF THE MODEL GUIDANCE SUGGESTS A LOW LEVEL CLOUD DECK TONIGHT...BUT NOT TOTALLY BUYING THIS AS ANOTHER LOW APPROACHES FROM THE NORTH. VICINITY OF KSFO...FORECASTING VFR THROUGH THE PERIOD. HIGH CIGS TOMORROW AS ANOTHER LOW SLIDES THROUGH. WILL NOT INTRODUCE ANY PRECIP AS IT WILL BE SCT AND BEST CHC SOUTH OF SFO/OAK. CONFIDENCE IS HIGH. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...VFR THROUGH THE PERIOD. SCT CU DECK POSS THIS AFTERNOON. CONFIDENCE IS HIGH. && .MARINE...AS OF 09:22 AM PST SUNDAY...LIGHT TO MODERATE WINDS WILL PREVAIL OVER THE BAY AREA WATERS TODAY AS A STORM SYSTEM EXITS TO THE SOUTH. ANOTHER STORM SYSTEM WILL MOVER OVER THE REGION ON MONDAY WITH ANOTHER CHANCE FOR SHOWERS...THUNDERSTORMS AND GUSTY WINDS. WINDS WILL BE STRONGEST NORTH OF PIGEON POINT OVER THE OUTER WATERS. LIGHT WINDS AND GENTLE SEAS DEVELOP ON TUESDAY. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. && $$ PUBLIC FORECAST: RWW AVIATION/MARINE: MM VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
845 AM PST SUN MAR 1 2015 .SYNOPSIS...MOSTLY SUNNY TODAY EXCEPT SOME SHOWERS OVER THE HILLS OF MONTEREY AND SAN BENITO COUNTY THIS AFTERNOON. ANOTHER WEAK WEATHER SYSTEM WILL DROP DOWN THE COAST BRINGING SOME SCATTERED SHOWERS TO THE REGION MONDAY AFTERNOON...MAINLY OVER THE HILLS AND ALONG THE COAST. HIGH PRESSURE BUILDS TUESDAY THROUGH NEXT WEEKEND WITH A RETURN TO DRY CONDITIONS...MOSTLY CLEAR SKIES AND ABOVE NORMAL DAYTIME TEMPERATURES. && .DISCUSSION...AS OF 8:45 AM PST SUNDAY...SKIES ARE MOSTLY SUNNY THIS MORNING ACROSS THE BAY AREA AS THE CALENDAR HAS TURNED TO MARCH. YESTERDAYS UPPER LOW IS NOW WEST OF POINT CONCEPTION WITH SOME COLD AIR ALOFT AND INSTABILITY OVER THE CENTRAL COAST AND SOUTHERN CALIFORNIA. THE BAY AREA WILL SEE SKIES TURN PARTY CLOUDY THIS AFTERNOON WITH SOME CLOUDS OVER THE HILLS AND AFTERNOON HIGHS IN THE MID 60S. MONTEREY AND SAN BENITO COUNTY WILL STAY CLOSE ENOUGH TO THE UPPER LOW TO KEEP AFTERNOON SHOWERS AND EVEN AN ISOLATED T-STORM IN THE FORECAST. THE 12Z NAM AND LATEST RUNS OF THE RAP AND HRRR MODELS ALL GENERATE SOME CONVECTIVE SHOWERS OVER THE HILLS OF SAN BENITO AND MONTEREY COUNTY AND CURRENT FORECAST HAS THAT COVERED. WILL HAVE TO MONITOR FOR SOME SMALL HAIL AND LIGHTNING THREAT. SPC HAS THIS COVERED WITH THE REGION IN THE GENERAL T-STORM OUTLOOK TODAY AS WELL. SKIES WILL TURN MOSTLY CLEAR OVERNIGHT...SETTING THE STAGE FOR A FAIRLY CHILLY NIGHT AS WINDS BECOME LIGHT WITH A COOL AND DRY AIRMASS OVER THE REGION. NEXT SYSTEM WILL QUICKLY DROP DOWN THE COAST ON MONDAY BUT MODELS ARE IN SOLID AGREEMENT SHOWING THE MAIN RAIN SHIELD STAYING OFFSHORE. THE SYSTEM IS DROPPING FROM THE NORTH WITH A FAIRLY COLD AIRMASS ALOFT. THUS THERE WILL BE ENOUGH INSTABILITY TO PRODUCE SOME SCATTERED SHOWERS MONDAY AFTERNOON...MAINLY OVER THE HILLS ONCE AGAIN. ACTIVITY WILL BE LESS WIDESPREAD THAN WHAT WAS OBSERVED SATURDAY AND EXPECT MOST AREAS TO STAY DRY. IN FACT MODELS ARE SHOWING THE BEST CHANCES ONCE AGAIN OVER THE HIGHER TERRAIN OF MONTEREY AND SAN BENITO WITH THE TRAJECTORY OF THE LOW. ANY SHOWERS END AS THE SUN SETS MONDAY EVENING. THEN HIGH PRESSURE BUILDS TUESDAY THROUGH NEXT WEEKEND WITH A WARMING AND DRYING TREND. UNFORTUNATELY IT LOOKS LIKE ANY RAIN CHANCES DISAPPEAR UNTIL MIDDLE OF THE MONTH. && .AVIATION...AS OF 4:04 AM PST SUNDAY...THE CURRENT IR SATELLITE IMAGE IS SHOWING YESTERDAYS STORM SYSTEM NOW CENTERED JUST OFF OF POINT ARGUELLO. THIS IS PLACING THE SAN FRANCISCO AND MONTEREY BAY AREA IN A ZONE OF OFFSHORE FLOW. THIS OFFSHORE FLOW WILL PREVENT STRATUS FROM FORMING TODAY. HOWEVER...RESIDUAL MOISTURE FROM YESTERDAYS STORM SYSTEM WILL PROMOTE THE FORMATION OF CUMULUS CLOUDS THIS AFTERNOON. VICINITY OF KSFO...VFR IS ANTICIPATED TO PREVAIL TODAY WITH MVFR CLOUD BASES THIS AFTERNOON. LIGHT OFFSHORE WINDS ARE EXPECTED TO GIVE WAY TO A GENTLE SEA BREEZE THIS AFTERNOON. CONFIDENCE IS HIGH. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...VFR IS ANTICIPATED TO PREVAIL TODAY WITH MVFR CLOUD BASES THIS AFTERNOON. LIGHT OFFSHORE WINDS ARE EXPECTED TO GIVE WAY TO A GENTLE SEA BREEZE THIS AFTERNOON. CONFIDENCE IS HIGH. && .MARINE...AS OF 2:42 AM PST SUNDAY...A WEAK SURFACE PRESSURE GRADIENT WILL PROMOTE GENERALLY LIGHT WINDS ACROSS A MAJORITY OF THE COASTAL WATERS TODAY. A STORM SYSTEM WILL SLIDE OVER THE COASTAL WATERS ON MONDAY BRINGING ANOTHER ROUND OF SHOWERS AND POTENTIAL THUNDERSTORMS TO THE AREA. THIS FAST MOVING SYSTEM WILL BE OUT OF THE AREA TUESDAY LEAVING BEHIND LIGHT WINDS AND GENTLE SEAS FOR THE REMAINDER OF THE WEEK. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. && $$ PUBLIC FORECAST: RWW AVIATION/MARINE: LARRY VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1058 AM MST SUN MAR 1 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 414 AM MST SUN MAR 1 2015 RADAR CONTINUES TO SHOW ECHOES OVR PORTIONS OF THE SANGRES THIS MORNING...WITH WEB CAMS SHOWING SNOW IN THE CENTRAL AND SW MTNS. THERE MAY BE OCNL SNOW SHOWERS IN SOME LOCATIONS OF THE SAN LUIS VALLEY AS WELL. HYR CLOUDS HAVE DECREASED OVR THE SERN PLAINS...BUT THERE ARE AREAS OF LOW CLOUDS AND FOG WITH THE POTENTIAL FOR SOME FLURRIES. AN UPR LOW WL REMAIN ALONG THE SRN CA COAST THRU THE DAY. THE UPR LOW IS FORECAST TO WEAKEN TONIGHT...WITH THE UPR TROF BEGINNING TO MOVE EASTWARD. W TO SW FLOW ALOFT WL CONTINUE ACRS CO TODAY AND TONIGHT. THIS WL ALLOW THE CONTINUED STREAM OF MSTR INTO THE CONTDVD. ALTHOUGH THE MTNS OF THE CONTDVD WL GET SEVERAL ADDITIONAL INCHES OF ACCUMULATION TODAY AND TONIGHT...THE ERN SAN JUAN MTNS WL STILL BE THE HARDEST HIT AREA. WINDS THIS MORNING ARE NOT REACHING BLIZZARD CRITERIA OVER ZONE 68...BUT LATER TODAY THEY ARE EXPECTED TO PICK UP AGAIN AND GUSTS OVERNIGHT SHOULD AGAIN BE QUITE STRONG...AND WITH THE HEAVY SNOW CONTINUING THE BLSN AND NEAR ZERO VSBYS WL BE QUITE DANGEROUS. WL LEAVE THE BLIZZARD WARNING AS IS. THE NAM THE GFS AND HRRR ARE SHOWING DRY CONDITIONS OVR THE SERN PLAINS AND I-25 CORRIDOR THRU EARLY AFTERNOON...SO WL REMOVE POPS IN THESE AREAS. PROBABLY WL NOT SEE MUCH IN THE WAY OF PCPN OVR MOST OF THE SAN LUIS VALLEY EITHER...BUT SOME ISOLD SHOWERS ARE STILL POSSIBLE. MODELS CONTINUE TO SHOW PCPN RAMPING UP OVR THE ERN MTNS AROUND MIDAFTERNOON AND SPILLING OUT OVR PORTIONS OF THE I-25 CORRIDOR THRU THE EVENING HOURS. THE LAST COUPLE DAYS...THE MODELS HAVE KEPT THE FOCUS OF THE PCPN MAINLY FROM THE WET MTNS AND NRN SANGRES AND LOCATIONS NORTH...NOT REALLY SHOWING ALL THAT MUCH FOR THE SRN SANGRES...AND THE NAM AND HRRR STILL HAVE THAT TREND. THIS MORNING THE GFS SHOWS MORE ACTIVITY OVR THE SRN SANGRES THIS AFTERNOON THAN THE HRRR AND NAM. EAST TO SOUTHEASTERLY UPSLOPE OVR EL PASO COUNTY THIS AFTERNOON AND EVENING HELP ENHANCE PCPN CHANCES AND WL KEEP POPS HIGH IN THIS AREA. THE MODELS SHOW LITTLE CHANCE FOR PCPN OVR MOST OF THE SERN PLAINS THIS AFTERNOON AND EVENING... BUT WL PUT SOME ISOLD POPS IN THE FORECAST. BY LATE NIGHT...PCPN OVR THE SERN PLAINS AND I-25 CORRIDOR SHOULD GENERALLY BE LIGHT...HOWEVER THE SOUTHERLY FLOW OVR EL PASO COUNTY SHOULD KEEP SNOW GOING ALTHOUGH IT SHOULD BE GENERALLY LIGHT BUT THERE SHOULD BE A LITTLE ACCUMULATION WHICH COULD MAKE FOR A SLIPPERY MONDAY MORNING COMMUTE. ALSO...THE NAM AND GFS CONTINUE TO SHOW THE POTENTIAL FOR A FEW TO SEVERAL INCHES OF SNOW ACCUMULATIONS OR THE NRN SANGRES... THE WET MTNS VALLEY AND FREMONT COUNTY THRU THE NIGHT. ONE CONCERN IS THAT IF LIGHT PCPN DOES OCCUR OVR THE FAR SERN PLAINS...THE SOUNDING PROFILE STILL DOES SHOW THE POTENTIAL FOR SOME LIGHT FREEZING DRIZZLE...BUT WL NOT MENTION IN THE FORECAST AT THIS TIME. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 414 AM MST SUN MAR 1 2015 ...UNSETTLED WEATHER CONTINUES THROUGH WEDNESDAY WITH DRIER AND WARMER WEATHER THEREAFTER... MONDAY-MONDAY NIGHT...SOUTHWEST FLOW ALOFT INCREASES AGAIN ACROSS THE REGION ON MONDAY AND BECOMES MORE WESTERLY MONDAY NIGHT WITH A STRONG SUBTROPICAL JET STREAM TRANSLATING ACROSS THE STATE AS SOUTHERN STREAM ENERGY ACROSS THE DESERT SW MERGES WITH ANOTHER PIECE OF ARCTIC AIR WITHIN A STRONG NORTHERN STREAM TROUGH DIGS ACROSS THE INTERMOUNTAIN WEST AND NORTHERN GREAT BASIN. SNOWFALL OVER AND NEAR THE MOUNTAINS LOOKS TO BE ON THE WANE EARLY MONDAY MONDAY MORNING BUT IS EXPECTED TO INCREASE AGAIN MONDAY AFTERNOON AND EVENING...ESPECIALLY OVER AND NEAR THE CONTDVD...WITH INCREASING MOISTURE...UVV AND OROGRAPHICS AHEAD OF THE COMBINING SYSTEMS. CURRENT WINTER WEATHER HIGHLIGHTS ACROSS THE HIGHER TERRAIN THROUGH THE DAY MONDAY MAY NEED TO BE EXTENDED INTO EARLY TUESDAY MORNING...WITH ANOTHER ROUND OF MODERATE TO HEAVY SNOWFALL EXPECTED...ESPECIALLY ALONG AND WEST OF THE DVD. IN ADDITION TO THE SNOW...INCREASING FLOW ALOFT WILL LEAD TO STRONG AND GUSTY SOUTHWEST TO WEST WINDS OF 25 TO 45 MPH AND AREAS OF BLOWING AND DRIFTING SNOW ACROSS THE HIGHER TERRAIN. FURTHER EAST...A FEW MORNING SHOWERS WILL BE POSSIBLE ACROSS THE EASTERN PLAINS WITH BREEZY TO WINDY CONDITIONS HELPING TO BOOST HIGHS MONDAY INTO THE 30S AND 40S AND KEEP OVERNIGHT LOWS FAIRLY MILD MAINLY IN THE 20S AND 30S. TUESDAY-WEDNESDAY NIGHT...STRONG WEST TO NORTHWEST FLOW ALOFT ACROSS THE AREA TUESDAY MODERATES THROUGH THE DAY WEDNESDAY AND WEDNESDAY AS NORTHERN STREAM TROUGH AND ARCTIC AIRMASS DIGS ACROSS THE ROCKIES AND INTO THE HIGH PLAINS. SOME DIFFERENCES IN TIMING OF ARCTIC FRONT ACROSS THE AREA WITH LEADING EDGE OF COLD AIR MOVING ACROSS EASTERN COLORADO EARLY TUESDAY MORNING AND HIGHS MOST LIKELY BEING REACHED BY MID MORNING WITH TEMPERATURES COOLING THEREAFTER. COULD SEE SOME SHOWERS ACROSS THE AREA WITH THE FRONT THOUGH BEST CHANCES OF LIGHT TO MODERATE SNOWFALL LOOKS TO BE LATER TUESDAY AFTERNOON AND NIGHT AS ANOTHER LOBE OF ENERGY AND SECONDARY SURGE OF COLD AIR DROPS ACROSS THE ROCKIES KEEPING TEMPERATURES WELL BELOW SEASONAL AVERAGES WITH LOWS MAINLY IN THE SINGLE DIGITS AND HIGHS MAINLY IN THE TEENS AND 20S. DRIER AIR AND SUBSIDENCE WITHIN THE MODERATING NORTHWEST FLOW ALOFT WILL ALLOW FOR SNOW TO GRADUALLY END WEDNESDAY AFTERNOON AND EVENING. THURSDAY-SATURDAY...A WARMING AND DRYING TREND REMAINS IN THE OFFING FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND AS UPPER LEVEL RIDGING BUILDS ACROSS THE WEST COAST AND INTO THE GREAT BASIN. LATEST MODELS...HOWEVER...ARE INDICATING ANOTHER WEAK WAVE WITHIN THE STRONGER NORTHWEST FLOW ALOFT ACROSS THE NORTH TIER OF STATES...DROPPING ACROSS THE ROCKIES ON SATURDAY. WITH THAT SAID...HAVE STAYED WITH MODEL CONSENSUS POPS WHICH BRINGS SLIGHT CHANCES FOR LIGHT SNOW ACROSS THE HIGHER TERRAIN ON SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1048 AM MST SUN MAR 1 2015 KCOS...VFR TO INTERMITTENT MVFR DUE TO PATCHY LIGHT GROUND FOG THROUGH 20-21Z...THEN TRENDING TOWARDS IFR AS SNOW MOVES BACK INTO THE AREA. SHOULD REMAIN IFR THROUGH 12-14Z DUE TO SNOW...FOG AND LOW CLOUD DECK THOUGH GROUND FOG MAY LINGER BEYOND SNOW FOR A FEW MORE HOURS MONDAY MORNING. KPUB...VFR UNTIL 21-23Z THEN IFR-MVFR CONDITIONS EXPECTED AS SNOW MOVES IN. SHOULD REMAIN MVFR-IFR THROUGH 12-14Z DUE TO SNOW...FOG AND LOW CLOUD DECK THOUGH GROUND FOG MAY LINGER BEYOND SNOW FOR A FEW MORE HOURS MONDAY MORNING. KALS...INTERMITTENT SNOW HAS MOVED BACK INTO THE AREA THIS AFTN...AND WITH PATCHY FOG AND LOW CLOUDS WILL CONTINUE MVFR TO IFR CONDITIONS OVER THE NEXT 24 HRS. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060-061- 066-067-073-075. WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ059-064-065- 074. BLIZZARD WARNING UNTIL 11 PM MST MONDAY FOR COZ068. && $$ SHORT TERM...28 LONG TERM...MW AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1010 AM MST SUN MAR 1 2015 .UPDATE... ISSUED AT 1003 AM MST SUN MAR 1 2015 MINOR ADJUSTMENTS TO THE GRIDS THIS MORNING..I SLOWED THE TIMING OF THE HIGHER POPS A BIT THIS AFTERNOON. OVERRUNNING MOISTURE WILL PRODUCE JUST SOME LIGHT SNOW TODAY...OVERALL SLGT CHC IN THE URBAN CORRIDOR...WITH CHC POPS NEAR THE FOOTHILLS. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 346 AM MST SUN MAR 1 2015 THE FLOW ALOFT WILL BECOME MORE SWLY TODAY AND THEN INCREASE TONIGHT AS AN UPPER LEVEL LOW REMAINS OVER CALIFORNIA. SO FAR MOST OF THE CWA IS ON THE SUBSIDENT SIDE OF THE UPPER LEVEL EXCEPT CLOSER TO THE WY BORDER WHERE OROGRAPHIC SNOWS HAVE BEEN OCCURRING OVER THE HIGHER TERRAIN OF BOULDER AND LARIMER COUNTIES. SOME OF THIS ACTIVITY HAS SPREAD ACROSS THE LOWER ELEVATIONS OF LARIMER COUNTY AND NWRN WELD COUNTY. APPEARS MOST OF THIS ACTIVITY WILL END AROUND 12Z EXCEPT IN THE MTNS. BY LATER THIS MORNING THRU EARLY AFTN DRIER AIR WILL SPREAD ACROSS THE MTNS WHICH WILL REDUCE SNOW CHANCES. BY LATE AFTN INTO THE EVENING HOURS ANOTHER SURGE OF MOISTURE IS SUPPOSED TO MOVE INTO THE MTNS. SATELLITE DOES SHOW ENHANCEMENT OVER ARIZONA SO IT APPEARS THAT THIS MOISTURE IS REAL. THUS SHOULD SEE AN INCREASE IN SNOW ACTIVITY IN THE MTNS. AT LOWER ELEVATIONS NOT SURE HOW THINGS ARE GOING TO EVOLVE. THE HRRR AND RAP SHOW SNOW DEVELOPING IN THE SRN FOOTHILLS AND AFFECTING SRN AREAS OF THE URBAN CORRIDOR AND PALMER DIVIDE BY LATE AFTN INTO THE EARLY HOURS. THUS WILL KEEP HIGHEST POPS OVER SRN AREAS OF CWA WITH LOWER POPS FURTHER NORTH. AS FOR HIGHS WILL KEEP READINGS N THE 20S OVER NERN CO EXCEPT OVER THE FAR NERN CORNER WHERE READINGS MAY RISE INTO THE LOWER 30S. OVERNIGHT SWLY FLOW WILL INTENSIFY WITH ABUNDANT MOISTURE IN THE MTNS. PLACEMENT OF UPPER LEVEL JET COULD ALLOW FOR SOME HEAVIER SNOWFALL LATE TONIGHT IN ZN 31 AND PORTIONS OF ZN 33 ALTHOUGH MID LVL TEMPS ARE WARMING QUITE A BIT WHICH COULD LIMIT AMOUNTS. OVER NERN CO THE LOW LVL FLOW WILL BECOME MORE SSE AFTER MIDNIGHT WITH STG DOWNSLOPING COMING OFF THE PALMER DIVIDE WHICH SHOULD DECREASE PCPN CHANCES FM DENVER SOUTH TO THE PALMER DIVIDE. CLOSER TO THE WY BORDER THE LOW LVL FLOW WILL BE MORE SELY SO COULD STILL SEE A CHC OF LIGHT SNOW OVERNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 346 AM MST SUN MAR 1 2015 VERY STRONG SOUTHWESTERLY JET LEVEL FLOW IS PROGGED OVER THE CWA MONDAY AND MONDAY NIGHT. THE PROGGED SPEEDS ARE IN THE 130 TO 160 KNOT RANGE AT JET LEVEL. BY TUESDAY...THE FLOW ALOFT BECOMES MORE WESTERLY THROUGH THE DAY AS AN UPPER TROUGH MOVES INTO COLORADO. THE UPPER TROUGH IS OVER THE STATE TUESDAY AFTERNOON WELL INTO THE EXTENDED PERIOD. THERE IS WEAK UPWARD QG VERTICAL VELOCITY PROGGED FOR THE CWA MONDAY...BUT IT BECOMES STRONGER BY AFTERNOON AND OVERNIGHT. ANOTHER BATCH OF UPWARD ENERGY MOVES ACROSS THE FORECAST AREA TUESDAY AFTERNOON WITH SUBSIDENCE BY TUESDAY NIGHT. THE BOUNDARY LAYER FLOW LOOKS TO BE SOUTH- SOUTHWESTERLY ON MONDAY. NORMAL DIURNAL PATTERNS SHOULD KICK IN MONDAY EVENING...THEN A COLD FRONT WITH UPSLOPE MOVES IN SOMETIME AFTER MIDNIGHT AND TUESDAY MORNING AT DAWN. NORTH-NORTHEASTERLY WINDS ARE PROGGED TUESDAY AND TUESDAY NIGHT. FOR MOISTURE...THERE IS BIT OVER THE PLAINS MONDAY...BUT DEEPER MOISTURE FOR THE MOUNTAINS. MOISTURE REMAINS PRETTY DEEP OVER THE MOUNTAINS MONDAY NIGHT...WITH AN INCREASE AFTER THE FRONT MOVES ACROSS FOR THE PLAINS. MOISTURE IS PRETTY DEEP IN ALL AREAS BY TUESDAY AFTERNOON AND NIGHT. THERE IS SOME QPF PROGGED OVER THE MOUNTAINS MONDAY THROUGH TUESDAY EVENING. FOR THE PLAINS THERE IS SOME MONDAY EVENING THROUGH TUESDAY NIGHT. FOR POPS...WILL NOT ALTER THINGS TO MUCH...MAY START THEM OVER THE PLAINS A BIT LATER ON MONDAY NIGHT/TUESDAY MORNING. NO HIGHLIGHTS RIGHT NOW...BUT MOUNTAINS MIGHT NEED SOMETHING. WE`LL SEE. FOR TEMPERATURES...MONDAY`S HIGHS ARE 4-11 C WARMER THAN TODAY`S EXPECTED HIGHS. TUESDAY`S HIGHS BEHIND THE FRONT COOL BACK OFF 11-18 C FROM MONDAY`S. DEPENDING HOW MUCH IT CLEARS OUT TUESDAY NIGHT/WEDNESDAY MORNING...WE COULD GET BELOW ZERO FOR LOWS OUT ON THE FOR THAT PERIOD. FOR THE LATER DAYS...WEDNESDAY THROUGH SATURDAY...MODELS HAVE THE UPPER TROUGH GET THROUGH THE CWA ON WEDNESDAY...THEN WEAK NORTHWESTERLY FLOW IS PROGGED FOR THE CWA WEDNESDAY NIGHT INTO FRIDAY MORNING. THEN FAIRLY WEAK WEST OR WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED THROUGH SATURDAY. MOISTURE IS LACKING...IT ACTUALLY LOOKS PRETTY DRY ALL FOUR DAYS. TEMPERATURES STAY BELOW SEASONAL NORMALS ALL FOUR DAYS. && .AVIATION...(FOR THE TAFS THROUGH 18Z MONDAY MORNING) ISSUED AT 1003 AM MST SUN MAR 1 2015 TREND OF IMPROVING CONDITIONS AT KDEN THE REMAINDER OF THE MORNING...IFR NO LONGER EXPECTED BUT MAINLY MVFR CIG/VSBY RESTRICTIONS AT TIMES THROUGH THE AFTN. BEST CHC OF SNOW LATE THIS AFTN AND EVENING WILL STAY TO THE WEST AND SOUTH OF DIA NEAR KAPA AND KBJC WITH ONLY LIGHT ACCUMULATIONS EXPECTED. WINDS WILL BE LIGHT AND VARIABLE THIS MORNING AND THE MORE ELY BY THIS AFTN. BY THIS EVENING WINDS WILL BECOME MORE SELY AND THEN SLY AFTER MIDNIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...COOPER SHORT TERM...RPK LONG TERM...RJK AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
426 PM EST SUN MAR 1 2015 .SYNOPSIS... A FRONTAL SYSTEM WILL APPROACH FROM THE WEST...THEN PASS THROUGH TONIGHT AS WEAK LOW PRESSURE DEVELOPS SOUTH OF LONG ISLAND. HIGH PRESSURE WILL BRIEFLY BUILD IN MONDAY INTO MONDAY NIGHT... THEN PASS TO THE EAST ON TUESDAY. LOW PRESSURE WILL TRACK WELL NORTH OF THE AREA TUESDAY NIGHT AND WEDNESDAY...WITH A WARM FRONT LIFTING INTO THE AREA TUESDAY NIGHT...FOLLOWED BY A COLD FRONT WEDNESDAY AND A REINFORCING COLD FRONT WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... BAND OF FRONTOGENETICALLY FORCED MODERATE TO HEAVY SNOW ACROSS LONG ISLAND AND NYC METRO ATTM...WITH SNOWFALL RATES UP TO AN INCH PER HOUR. PER HRRR THIS BAND SHOULD SHIFT MORE INTO LONG ISLAND AND COASTAL CT OVER THE NEXT COUPLE OF HOURS...AND PERSIST THERE INTO AT LEAST THE FIRST PART OF THIS EVENING. HAVE BUMPED UP SNOWFALL TOTALS ESPECIALLY ACROSS SUFFOLK COUNTY AND AND COASTAL SE CT. GIVEN THIS PLUS A SPOTTER REPORT OF 2 INCHES ON THE GROUND IN WEST ISLIP...WILL ISSUE WINTER STORM WARNINGS FOR THOSE AREAS...WHERE 5-7 INCHES OF ACCUMULATION IS EXPECTED. ELSEWHERE EXPECT A SOLID ADVY EVENT...WITH 4-6 INCHES OF SNOW. A SPOTTER FROM BROOKLYN REPORTED SLEET MIXING IN WITH THE SNOW...WHICH CORRELATES WELL WITH RADAR DUAL-POL CC. THIS TRANSITION SHOULD BE BRIEF...AND EXPECT PRECIP TO TRANSITION BACK MORE TOWARD SNOW BEFORE A MORE DEFINITE TRANSITION LINE NOW EXTENDING FROM TTN-WRI-ACY MOVES IN. THIS SHOULD MAKE IT TO NYC METRO BY 00Z...THEN TO NEAR TEB-ISP BY LATE EVENING. AREAS SOUTH OF THAT LINE SHOULD SEE A GLAZE TO A TENTH OF AN INCH OF ICE THIS EVENING BEFORE PRECIP WINDS DOWN AFTER MIDNIGHT. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... HIGH PRESSURE APPROACHES FROM THE WEST ON MONDAY...THEN BUILDS OVERHEAD ON TUESDAY. HIGHS ON MON WILL BE IN THE MID AND UPPER 30S...WITH A BRISK NW WINDS GUSTING TO 25-35 MPH. MUCH COLDER AIR WILL FOLLOW FOR MON NIGHT...AND UNDERCUT MOS GUIDANCE BY 2-3 DEG GIVEN DIMINISHING WINDS LATE AT NIGHT AND FRESH SNOW COVER...WITH LOWS IN THE TEENS FOR NYC METRO AND LONG ISLAND...AND SINGLE DIGITS FARTHER NORTH/WEST. && .LONG TERM /TUESDAY THROUGH SATURDAY/... MODELS ARE IN DECENT AGREEMENT AT H5 THROUGH THE WEEK...ALTHOUGH SLIGHT DIFFERENCES IN HEIGHTS BEGIN TO TAKE SHAPE DURING THE LATTER HALF FROM A DIGGING TROF IN THE MIDDLE OF THE COUNTRY. RIDGING AT THE SFC AND ALOFT TRACKS MOVES OFFSHORE ON TUE. PCPN WILL OVERSPREAD THE AREA LATE TUE AFTN AS SNOW...BUT WITH INCREASING S-SW WINDS AND STRONG WAA TEMPS WILL WARM TUE EVE/NIGHT WITH SNOW CHANGING TO MIXED PCPN THEN RAIN FROM S TO N. WARM FRONT LIFTS TOWARDS THE AREA TUE NIGHT...BUT THERE IS SOME UNCERTAINTY IF THE LLJ WILL BE STRONG ENOUGH TO PUSH IT THROUGH AT THE SFC. CLIMATOLOGY SAYS NO WITH THE LOW SO FAR TO THE NW AND VERY COLD WATERS/ICE...SO HAVE GONE BELOW GUIDANCE WITH HIGHS WED...GENERALLY LOWER 40S WITH MID 40S POSSIBLE IN NYC METRO. THE COMBINATION OF THESE TEMPS AND RAINFALL WILL RESULT IN MELTING SNOWPACK WHICH COULD LEAD TO MINOR FLOODING ACROSS THE AREA ON WED. COLD FRONT MOVES ACROSS WED FOLLOWED BY A REINFORCING COLD FRONT WED NIGHT. THE NORTHERN EDGE OF THE PCPN SHIELD OF A SOUTHERN STREAM SYSTEM RIDING ALONG THIS SECONDARY BOUNDARY COULD KEEP PCPN LINGERING WED NIGHT INTO THU. MODELS REMAIN SPLIT ON THIS...GFS IS FURTHER SUPPRESSED THAN EC SO HAVE KEPT CHC POPS. COLD AIR FILTERS IN BEHIND THE INITIAL COLD FRONT ON WED. THERMAL PROFILES SUPPORT A CHANGE BACK OVER TO SNOW WED NIGHT AND THU WITH ANY PCPN ASSOCIATED WITH THE SOUTHERN STREAM SYSTEM. ANOTHER SHOT OF ARCTIC AIR INFILTRATES THE AREA THU INTO FRI. STRONG CANADIAN HIGH PRES THEN BUILDS TOWARDS THE AREA INTO THE WEEKEND WITH DRY WEATHER. TEMPS WILL REBOUND AROUND 5 DEGREES BELOW NORMAL NEXT WEEKEND WITH WAA DEVELOPING. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... WEAK LOW PRESSURE WILL TRACK TO THE SOUTH THEN EAST OF LONG ISLAND TONIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST ON MONDAY. MAINLY LIFR TO VLIFR ACROSS THE AREA...WITH POCKETS OF IFR IN MAINLY MODERATE TO OCCASIONALLY HEAVY SNOW. SHOULD REMAIN ALL SNOW KSWF/KHPN/KBDR/KGON/KTEB. SNOW WILL CHANGE TO ZR AT KJFK AROUND 1Z AND CHANGE TO ZR AT KISP AROUND 2Z. FOR NOW HAVE KEPT CHANGE OVER AT KEWR AND KLGA TO ZR AT 3Z...BUT BEGINNING TO HAVE SOME DOUBTS THIS WILL OCCUR. PRECIPITATION WILL COME TO AN END A COUPLE OF HOURS ON EITHER SIDE OF MIDNIGHT FROM W TO E. MOST LIKELY TOTAL RUNWAY ACCUMULATIONS BY 06Z MON: KGON/KISP...4-7 INCHES. KSWF/KHPN/KBDR/KTEB/KLGA/KJFK/KEWR...4-6 INCHES. AFTER THE PRECIPITATION ENDS...CONDITIONS TRANSITION TO VFR BY AROUND 12Z. WINDS IN THE PROCESS OF BECOMING LIGHT AND VARIABLE THROUGHOUT. AS THE PRECIPITATION ENDS WINDS GO SW THEN W AT UNDER 10 KT EARLY MONDAY MORNING. WINDS THEN BECOME NW AND INCREASE TO 13-18G22-27KT BY AROUND MID MONDAY MORNING. .OUTLOOK FOR 18Z MONDAY THROUGH WEDNESDAY... .MONDAY AFTERNOON-TUESDAY MORNING...VFR. NW WINDS G25-30 KT LIKELY INTO EARLY MONDAY EVENING. .TUESDAY AFTERNOON...CHANCE MVFR OR LOWER IN SNOW. .TUESDAY NIGHT...IFR OR LOWER LIKELY. SNOW...CHANGING TO A WINTRY MIX AFTER MIDNIGHT...AND THEN RAIN LATE AT ALL TERMINALS EXCEPT KSWF AND POSSIBLY CT TERMINALS. LLWS LIKELY. .WEDNESDAY...IFR OR LOWER POSSIBLE IN ANY RAIN - WITH A BRIEF PERIOD OF ZR POSSIBLE IN THE MORNING AT KSWF. LLWS POSSIBLE IN THE MORNING. .WEDNESDAY NIGHT-THURSDAY...MVFR OR LOWER POSSIBLE IN ANY PRECIPITATION...OTHERWISE VFR. IF THERE IS PRECIPITATION...SHOULD CHANGE TO ALL SNOW WEDNESDAY NIGHT AND POSSIBLY CONTINUE INTO THURSDAY. NW WINDS G15-20KT POSSIBLE. .THURSDAY NIGHT-FRIDAY...VFR. NW WINDS G15-20KT POSSIBLE THURSDAY NIGHT. && .MARINE... TRANQUIL TODAY WITH DEPARTING HI PRES...THEN WINDS INCREASE TO SCA LEVELS MON AND GRADUALLY DIMINISH MON NIGHT. EXPECT SUB-ADVY CONDS ON TUE AS HIGH PRES BUILDS ACROSS. SCA CONDS POSSIBLE ON THE OCEAN TUE NIGHT INTO THU BEHIND THE PASSAGE OF TWO COLD FRONTS...WITH A TIGHT PRES GRADIENT. SUB-ADVY CONDS THEN EXPECTED THEREAFTER AS THE PRES GRADIENT WEAKENS WITH ANOTHER BUILDING HIGH. && .HYDROLOGY... LIQUID EQUIVALENT QPF OF 4-6 TENTHS OF AN INCH EXPECTED TONIGHT. WITH ALL OF THIS EXPECTED TO BE EITHER FROZEN OR FREEZING PRECIPITATION...NO IMMEDIATE HYDROLOGIC IMPACT EXPECTED. BETWEEN 1/2 TO 1 INCH OF LIQUID EQUIVALENT PCPN IS POSSIBLE LATE TUE THROUGH WED. SOME OF THIS WILL FALL AS RAIN...THEREFORE THE COMBINATION OF THIS AND MELTING SNOW PACK COULD CAUSE MINOR FLOODING ISSUES. ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS TEMPERATURES REMAIN WELL BELOW AVERAGE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ005>012. NY...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR NYZ067>075- 078>081-176>179. NJ...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR NJZ002-004- 006-103>108. MARINE...SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO MIDNIGHT EST MONDAY NIGHT FOR ANZ330-335-338-340-345. SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO 6 AM EST TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...GOODMAN/24 NEAR TERM...GOODMAN SHORT TERM...GOODMAN LONG TERM...24 AVIATION...MALOIT MARINE...GOODMAN/24 HYDROLOGY...GOODMAN/24
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
116 PM EST SUN MAR 1 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY. HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... TODAY...A WELL PRONOUNCED COASTAL TROUGH LINGERS JUST OFF THE SOUTHEAST U.S. COAST...WHILE A SURFACE WEDGE REMAINS FIRMLY ENTRENCHED ACROSS INLAND AREAS WITH THE WEAKENING PARENT HIGH POSITIONED NEAR THE MID-ATLANTIC COAST. ABUNDANT LOW AND MID LEVEL MOISTURE COMBINED WITH ISENTROPIC ASCENT CONTINUES TO SUPPORT GOOD COVERAGE OF RAIN ACROSS SOUTHEAST SOUTH CAROLINA EARLY THIS AFTERNOON. THE HRRR AND OTHER HIGH RESOLUTION MESOSCALE MODELS APPEAR TO BE HANDLING LOCATION/COVERAGE OF THE PRECIPITATION FAIRLY WELL...AND GENERALLY SHOW THE RAIN SHIELD CONTINUING TO LIFT NORTHWARD THROUGH THE AFTERNOON. AS A RESULT...THE POP FORECAST SHOWS LOWERING RAIN CHANCES ACROSS SOUTHEAST GEORGIA THROUGH THE DAY...BUT PROBABILITIES PEAKING AT 70-90 PERCENT IN SOUTHEAST SOUTH CAROLINA THROUGH MID-AFTERNOON BEFORE RAIN CHANCES LOWER AS WELL LATE IN THE DAY. THE TEMPERATURE FORECAST REMAINS VERY TRICKY. WHILE THE COASTAL TROUGH IS NOT EXPECTED TO SHIFT INLAND DUE TO THE COOL/STABLE SHELF WATERS...MOST OF THE MODELS CONTINUE TO SHOW SOME WARMER AIR IN THE BOUNDARY LAYER ADVECTING JUST INLAND ALONG THE COAST. WITH THE MOST RECENT UPDATE...HAVE LOWERED TEMPERATURES ACROSS THE BOARD 1-3 DEGREES TO ACCOUNT FOR THE LATEST TRENDS. HIGHS ARE NOW FORECAST TO RANGE FROM THE LOWER/MID 40S INLAND TO THE MID 50S NEAR THE COAST. TONIGHT...WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING INTO TONIGHT WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A CONCERN FOR DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING ADVECTS NE INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW CONFIDENCE AT THIS JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY FOG TO AREAS OF FOG AS A TREND. THERE WILL PROBABLY BE PATCHY DRIZZLE AROUND THE REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES AND THE SYNOPTIC OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT READINGS MANY BE STEADY OR RISING LATE. && .SHORT TERM /MONDAY THROUGH TUESDAY/... MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO LOW/MID 50S IN SOUTHEAST GEORGIA. TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY AFTERNOON/EVENING. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... IFR CONDITIONS WILL PREVAIL AT THE TERMINALS THROUGH THE AFTERNOON WITH LIGHT RAIN/DRIZZLE PERSISTING. CEILINGS SHOULD DETERIORATE FURTHER AFTER 23Z...LOWERING TO LIFR LEVELS AT BOTH TERMINALS. VISIBILITIES WILL LOWER LATE TONIGHT AS WELL...DUE TO STRATUS BUILD DOWN AND/OR FOG FORMATION. AT THIS TIME...GUIDANCE APPEARS TO SHOW HIGHER PROBABILITIES OF DENSE FOG AT KSAV...SO HAVE INCLUDED A TEMPO GROUP FROM 08-12Z AT THAT TERMINAL WITH FURTHER REDUCED VISIBILITIES/CEILINGS. GRADUAL IMPROVEMENT IS GENERALLY EXPECTED AFTER ABOUT 15Z MONDAY AS SOMEWHAT DRIER AIR FILTERS IN ON A WEST-NORTHWEST FLOW...BUT CONDITIONS WILL LIKELY REMAIN BELOW VFR THROUGH THE END OF THE FORECAST PERIOD AT 18Z. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY AFTERNOON. A BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT SHIFTS THROUGH THE AREA. && .MARINE... HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE WITH A MUCH LIGHTER GRADIENT BY LATER TODAY AND TONIGHT. IT WILL DIFFICULT TO TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT GIVEN THE STABLE CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW TO N LATER TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT OVER OUTER GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN ADVISORY LEVELS UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS COULD LOWER TO 1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE LAND/SEA INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS LIKELY WILL BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS. MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT. WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350- 352-354. SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374. && $$ SYNOPSIS... NEAR TERM...JAQ SHORT TERM...DPB LONG TERM...DPB AVIATION...JAQ/DPB MARINE...JAQ/DPB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1113 AM CST SUN MAR 1 2015 .UPDATE... ISSUED AT 637 AM CST SUN MAR 1 2015 OVERALL A FEW SMALL TWEAKS TO THE FORECAST WERE MADE. RADAR RETURNS SUGGEST THAT SNOW BAND COULD SHIFT A LITTLE FURTHER NORTH TODAY. AS SUCH INCREASED POPS FURTHER NORTH OF WHERE THEY WERE BEFORE. TOTAL SNOWFALL AMOUNTS REMAIN THE SAME AS EARLIER. SOME PATCHY DENSE FOG HAS DEVELOPED ACROSS THE AREA. THIS SEEMS TO BE LIMITED TO THE MISSISSIPPI RIVER VALLEY. THE FOG SHOULD BURN OFF THIS AM. OTHER THAN THAT FORECAST LOOKS TO BE ON TRACK. && .SYNOPSIS... ISSUED AT 149 AM CST SUN MAR 1 2015 VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE FOG. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 149 AM CST SUN MAR 1 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL. A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12 HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE CWA BY 18Z. AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE SHOULD END UP WITH SUN FOR THE SUNSET. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 149 AM CST SUN MAR 1 2015 THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING. SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD. IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE SHIFTS TODAY OR TONIGHT. SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO RUNOFF ISSUES ARE EXPECTED. AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY AND SATURDAY. ERVIN && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1109 AM CST SUN MAR 1 2015 VFR CONDITIONS FOR AT LEAST THE NEXT 24 HOURS. ANOTHER ARCTIC HIGH PRESSURE SYSTEM WILL MOVE IN FROM THE NORTHERN PLAINS. SKIES WILL CONTINUE TO CLEAR THIS AFTERNOON WITH LIGHT SOUTHWEST WINDS SHIFTING TO THE NORTHWEST AT 5 TO 10 KTS BY DUSK...CONTINUING THEN INTO MID DAY MONDAY. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...GIBBS SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...ERVIN AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
341 PM CST SUN MAR 1 2015 ...UPDATED SHORT TERM SECTION... .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 340 PM CST SUN MAR 1 2015 SOUTHWEST KANSAS FOUND ITSELF DOWNSTREAM OF WEAK SHORTWAVE RIDGING AS A BIG UPPER LOW REMAINED ANCHORED OFF THE COAST OF SOUTHERN CALIFORNIA. REMNANT COLD CANADIAN AIR REMAINED LOCKED IN PLACE WITH ALMOST NO ADVECTION OCCURRING THANKS TO VERY LIGHT WINDS. THERE IS SOME LIGHT NORTH-NORTHEAST WINDS AROUND 850MB, WHICH WILL CONTINUE TO PUSH SOME LOWER RH AIR TOWARD SOUTHWEST KANSAS...AIDING IN THE EVENTUAL SCOURING OUT OF STRATUS. WE WILL STILL SEE SOME MID AND HIGH LEVEL CLOUD AROUND THROUGH THE EVENING AND OVERNIGHT, THOUGH, AS WE REMAIN IN THE MOIST SOUTHWEST FLOW REGIME IN THE MID LEVELS. TEMPERATURES WILL FALL IN TO THE LOWER 20S BY 09-12Z MONDAY MORNING, AND WITH THE VERY LIGHT WINDS NEAR THE SURFACE RIDGE AXIS, WE WILL LIKELY SEE SOME LIGHT FOG DEVELOPMENT, SO WE HAVE INCLUDED SOME PATCHY FREEZING FOG ACROSS THE SOUTHERN COUNTIES (MAINLY SOUTH OF THE ARKANSAS RIVER). DENSE FOG DEVELOPMENT, HOWEVER, APPEARS UNLIKELY. DURING THE DAY MONDAY, WE WILL SEE THE SOUTHERN CALIFORNIA UPPER LOW MOVE SLOWLY EAST, AND THIS WILL LEAD TO LOW LEVEL DEVELOPMENT OF A LEE TROUGH, BUT RIGHT UP AGAINST THE MOUNTAINS. THE CHANGE IN PRESSURE GRADIENT WILL LEAD TO AN INCREASE IN SOUTH WINDS BY MIDDAY, BUT THE WINDS WILL STILL BE COLD, WITH THE TRAJECTORIES COMING FROM AROUND THE REMNANT SURFACE HIGH. AS A RESULT, WE HAVE BACKED OFF ON TEMPERATURES A FEW DEGREES, ONLY EXPECTING HIGHS IN THE 35 TO 37F RANGE AS A GENERAL RULE (COOLEST IN CENTRAL/SOUTH CENTRAL KANSAS). ELKHART SHOULD TOUCH LOWER 40S BY LATE IN THE AFTERNOON CLOSER TO THE LEE TROUGH AND SLIGHTLY WARMER LOWER TROPOSPHERE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 240 PM CST SUN MAR 1 2015 STRONG SOUTHERLY WINDS WILL BE FELT ACROSS WESTERN KANSAS MONDAY NIGHT WITH AN AREA OF SURFACE LOW PRESSURE LOCATED ACROSS NORTHEASTERN COLORADO. THIS AREA OF LOW PRESSURE WILL SHIFT EASTWARD AS TIME PROGRESSES DUE TO AN UPPER LEVEL SHORTWAVE MOVING INTO THE ROCKIES. THIS SHORTWAVE WILL CONTINUE TO MOVE EAST INTO THE PLAINS TUESDAY PUSHING A STRONG SURFACE COLD FRONT THROUGH THE AREA WITH AN ARCTIC DOME OF HIGH PRESSURE BEHIND IT. STRONG NORTHERLY WINDS ARE ANTICIPATED BEHIND IT WITH TEMPERATURES FALLING ACROSS THE AREA IN THE AFTERNOON. LOWER AND MID LEVELS OF THE ATMOSPHERE BECOME SATURATED TUESDAY NIGHT INTO WEDNESDAY LEADING TO A SLIGHT CHANCE OF SNOW SHOWERS. LITTLE TO NOW ACCUMULATION IS EXPECTED AT THIS TIME. OTHERWISE SKIES WILL BE MOSTLY CLOUDY. WINDS SHIFT BACK TO THE SOUTH BY WEDNESDAY NIGHT AS THE AREA OF HIGH PRESSURE MOVES EAST OF THE AREA. CLOUDS WILL ALSO DECREASE IN COVERAGE WEDNESDAY NIGHT AS DRIER AIR MOVES INTO THE AREA. THE REMAINDER OF THE EXTENDED LOOKS DRY AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WESTERN UNITED STATES PLACING NORTHWEST KANSAS IN A NORTHWEST FLOW ALOFT. MODELS SUGGEST A SHORTWAVE MOVING SOUTHEAST THROUGH THIS FLOW TOWARDS THE END OF THE WEEK BUT AS OF NOW THIS FEATURE ONLY INCREASES CLOUD COVER SLIGHTLY. AS FOR TEMPERATURES, LOWS MONDAY NIGHT REMAIN WARM AND IN THE LOW TO MID 30S. A LARGE RANGE OF TEMPERATURES ARE EXPECTED TUESDAY DUE TO THE AFOREMENTIONED COLD FRONT MOVING THROUGH EARLY IN THE DAY. HIGHS TUESDAY LOOK TO RANGE FROM THE MID 30S ACROSS WEST CENTRAL KANSAS TO UPPER 40S ACROSS SOUTH CENTRAL KANSAS. A COLD DAY IS EXPECTED WEDNESDAY WITH LOWS IN THE TEENS WEDNESDAY AND THURSDAY MORNINGS AND HIGHS IN THE UPPER 20S IN THE AFTERNOON. A WARMING TREND IS THEN EXPECTED AS WE HEAD INTO THE END OF THE WEEK WITH HIGHS IN THE 40S THURSDAY AND AROUND THE MID 50S FRIDAY AND SATURDAY. LOWS LOOK TO DIP INTO THE 20S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1137 AM CST SUN MAR 1 2015 CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS, RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 19 36 34 43 / 10 10 10 10 GCK 22 37 33 39 / 10 10 10 10 EHA 21 41 36 43 / 10 10 10 10 LBL 22 40 35 45 / 10 10 10 10 HYS 19 34 33 38 / 0 10 10 10 P28 19 35 33 47 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM...HOVORKA_42 AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
243 PM CST SUN MAR 1 2015 ...UPDATED LONG TERM SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CST SUN MAR 1 2015 WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT DEPRESSIONS HAVE BEEN THE SMALLEST. SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT. WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 240 PM CST SUN MAR 1 2015 STRONG SOUTHERLY WINDS WILL BE FELT ACROSS WESTERN KANSAS MONDAY NIGHT WITH AN AREA OF SURFACE LOW PRESSURE LOCATED ACROSS NORTHEASTERN COLORADO. THIS AREA OF LOW PRESSURE WILL SHIFT EASTWARD AS TIME PROGRESSES DUE TO AN UPPER LEVEL SHORTWAVE MOVING INTO THE ROCKIES. THIS SHORTWAVE WILL CONTINUE TO MOVE EAST INTO THE PLAINS TUESDAY PUSHING A STRONG SURFACE COLD FRONT THROUGH THE AREA WITH AN ARCTIC DOME OF HIGH PRESSURE BEHIND IT. STRONG NORTHERLY WINDS ARE ANTICIPATED BEHIND IT WITH TEMPERATURES FALLING ACROSS THE AREA IN THE AFTERNOON. LOWER AND MID LEVELS OF THE ATMOSPHERE BECOME SATURATED TUESDAY NIGHT INTO WEDNESDAY LEADING TO A SLIGHT CHANCE OF SNOW SHOWERS. LITTLE TO NOW ACCUMULATION IS EXPECTED AT THIS TIME. OTHERWISE SKIES WILL BE MOSTLY CLOUDY. WINDS SHIFT BACK TO THE SOUTH BY WEDNESDAY NIGHT AS THE AREA OF HIGH PRESSURE MOVES EAST OF THE AREA. CLOUDS WILL ALSO DECREASE IN COVERAGE WEDNESDAY NIGHT AS DRIER AIR MOVES INTO THE AREA. THE REMAINDER OF THE EXTENDED LOOKS DRY AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WESTERN UNITED STATES PLACING NORTHWEST KANSAS IN A NORTHWEST FLOW ALOFT. MODELS SUGGEST A SHORTWAVE MOVING SOUTHEAST THROUGH THIS FLOW TOWARDS THE END OF THE WEEK BUT AS OF NOW THIS FEATURE ONLY INCREASES CLOUD COVER SLIGHTLY. AS FOR TEMPERATURES, LOWS MONDAY NIGHT REMAIN WARM AND IN THE LOW TO MID 30S. A LARGE RANGE OF TEMPERATURES ARE EXPECTED TUESDAY DUE TO THE AFOREMENTIONED COLD FRONT MOVING THROUGH EARLY IN THE DAY. HIGHS TUESDAY LOOK TO RANGE FROM THE MID 30S ACROSS WEST CENTRAL KANSAS TO UPPER 40S ACROSS SOUTH CENTRAL KANSAS. A COLD DAY IS EXPECTED WEDNESDAY WITH LOWS IN THE TEENS WEDNESDAY AND THURSDAY MORNINGS AND HIGHS IN THE UPPER 20S IN THE AFTERNOON. A WARMING TREND IS THEN EXPECTED AS WE HEAD INTO THE END OF THE WEEK WITH HIGHS IN THE 40S THURSDAY AND AROUND THE MID 50S FRIDAY AND SATURDAY. LOWS LOOK TO DIP INTO THE 20S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1137 AM CST SUN MAR 1 2015 CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS, RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 18 36 34 43 / 10 10 10 10 GCK 18 37 33 39 / 10 10 10 10 EHA 20 41 36 43 / 20 10 10 10 LBL 23 40 35 45 / 10 10 10 10 HYS 17 34 33 38 / 10 20 10 10 P28 20 35 33 47 / 10 20 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...HOVORKA_42 AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1146 AM CST SUN MAR 1 2015 ...UPDATED AVIATION SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CST SUN MAR 1 2015 WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT DEPRESSIONS HAVE BEEN THE SMALLEST. SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT. WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 422 AM CST SUN MAR 1 2015 THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS. AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY BE IN THE FORM OF DRIZZLE. ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30. LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING BACK INTO THE 50S BY THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1137 AM CST SUN MAR 1 2015 CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS, RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 31 18 38 35 / 10 10 10 10 GCK 31 18 40 34 / 10 10 10 10 EHA 33 20 45 37 / 10 20 10 10 LBL 34 23 43 37 / 10 10 10 10 HYS 36 17 37 33 / 10 10 20 20 P28 32 20 37 34 / 20 10 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...GERARD AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1137 AM CST Sun Mar 1 2015 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 257 AM CST SUN MAR 1 2015 Expansive upper trough axis continues to rotate off the CA coast while weaker embedded areas of vorticity were lifting north and east towards Colorado and Kansas. A stronger shortwave trough was observed shifting southeast towards the northern plains later this morning. Lows were starting out in the teens and lower 20s with scattered light snow or flurries across northeast Kansas. Main highlight of the forecast is expected snowfall from sunrise through noon today. As the upper trough dives southeast, mid level forcing is enhanced within the embedded vorticity maxima tracking east over the state. Timing of this feature and area of weak frontogenesis will place the snow band near the Interstate 70 corridor based on latest runs of the RAP and NAM or just south near the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions. Duration of light snow is quick as well with lift diminishing eastward by mid afternoon today. Main changes for the forecast package were to remove precip chances for far north central Kansas as dry air aloft increases after sunrise. Also adjusted highest chances for snowfall in the above mentioned areas where an additional one half to one inch of snow is expected. Will maintain the advisory ongoing until noon and have the following shift remove counties as the snowfall exits. With the snowfall exiting quicker and the possibility of higher cloud bases, increased highs today a few degrees in the lower to possibly middle 30s. Weak high pressure shifts southeast this evening as skies become partly to mostly cloudy. Calm winds and snow covered ground hold lows in the upper teens to lower 20s. .LONG TERM...(Monday through Saturday) Issued at 257 AM CST SUN MAR 1 2015 For Monday models prog the mid level shortwave ridge to be over the area with low level moisture remaining to the south of the forecast. So with no real forcing expected to affect the area, have a dry forecast through the day. With some cloud cover and the surface ridge possibly influencing eastern KS still, have highs only reaching the mid and upper 30s. Monday night and Tuesday appear to be the next opportunity for precip as low level return flow advects moisture north while a shortwave kicks out from the base of the mid level trough over the southwest. However chances appear to remain limited. The model consensus shows the stronger Q vector convergence and PV anomaly passing just north of the forecast area while a dry slot moves into eastern KS by Tuesday morning. With the deeper moisture over far eastern KS, have kept the higher POPs across the east during the early morning hours Tuesday as the shortwave passes by. Prior to this there could be some drizzle develop and spread northeast through the area in response to the stronger low level moisture return. Depending on temps, there could be a brief period of light freezing drizzle. However I expect this to be short lived mainly in the evening as warm air advection should cause temps to rise through the night. Therefore any accumulations should be very minor. Another arctic ridge of high pressure is set to move through the forecast area Tuesday with the GFS trending a little faster with the frontal passage. However with the dry slot in place as the front moves through and upper level forcing likely to the northeast of the forecast area, the front may move through mostly dry through the early afternoon. The forecast anticipates falling temps through the afternoon as cold air moves in behind the front. But for the most part think that any precip on Tuesday is likely to be out ahead of the front and in the form of rain. There are still weak indications of some convective instability Tuesday morning. Because of this have kept a mention for thunder across east central KS. Lows Monday night are forecast to occur early in the evening while highs Tuesday are likely to be measured late in the morning. Tuesday night may be the last chance for precip through the rest of the week. There remains some indication for some mid level frontogenesis along with enough moisture for mid level saturation. The NAM is most bullish with this idea developing several hundredths of precip. While less impressive, the ECMWF also spits out some very light precip. Because of this have continued with a slight chance for snow Tuesday night. However would not anticipate the snow amounting to very much if at all. The upper level trough axis is progged to finally move east of the forecast area Wednesday night. But with dry air moving in with the arctic airmass on Tuesday, precip chances Wednesday and Wednesday night look to be less than 20 percent due to to much dry air. Wednesday is shaping up to be another cold day with lows in the teens and highs in the 20s. Thursday through Saturday continues to look dry with moderating temps as models keep a dry northwest flow over the central plains. By Friday, highs are expected to be in the 50s. This could be a little conservative with the GFS and ECMWF showing 925 MB temps warming to between +5 and +10C. For now stayed with the model consensus and have highs in the lower 50s. && .AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon) Issued at 1136 AM CST SUN MAR 1 2015 For the 18z TAFs, scattered to broken MVFR cigs will persist through the day as the storm system exits east of the area. As surface high pressure moves over the area tonight into Monday, northwesterly winds will veer toward the northeast and eventually to the southeast by the end of the TAF period. && .TOP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY until Noon CST today FOR KSZ058-059. && $$ SHORT TERM...Bowen LONG TERM...Wolters AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1135 AM CST Sun Mar 1 2015 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 257 AM CST SUN MAR 1 2015 Expansive upper trough axis continues to rotate off the CA coast while weaker embedded areas of vorticity were lifting north and east towards Colorado and Kansas. A stronger shortwave trough was observed shifting southeast towards the northern plains later this morning. Lows were starting out in the teens and lower 20s with scattered light snow or flurries across northeast Kansas. Main highlight of the forecast is expected snowfall from sunrise through noon today. As the upper trough dives southeast, mid level forcing is enhanced within the embedded vorticity maxima tracking east over the state. Timing of this feature and area of weak frontogenesis will place the snow band near the Interstate 70 corridor based on latest runs of the RAP and NAM or just south near the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions. Duration of light snow is quick as well with lift diminishing eastward by mid afternoon today. Main changes for the forecast package were to remove precip chances for far north central Kansas as dry air aloft increases after sunrise. Also adjusted highest chances for snowfall in the above mentioned areas where an additional one half to one inch of snow is expected. Will maintain the advisory ongoing until noon and have the following shift remove counties as the snowfall exits. With the snowfall exiting quicker and the possibility of higher cloud bases, increased highs today a few degrees in the lower to possibly middle 30s. Weak high pressure shifts southeast this evening as skies become partly to mostly cloudy. Calm winds and snow covered ground hold lows in the upper teens to lower 20s. .LONG TERM...(Monday through Saturday) Issued at 257 AM CST SUN MAR 1 2015 For Monday models prog the mid level shortwave ridge to be over the area with low level moisture remaining to the south of the forecast. So with no real forcing expected to affect the area, have a dry forecast through the day. With some cloud cover and the surface ridge possibly influencing eastern KS still, have highs only reaching the mid and upper 30s. Monday night and Tuesday appear to be the next opportunity for precip as low level return flow advects moisture north while a shortwave kicks out from the base of the mid level trough over the southwest. However chances appear to remain limited. The model consensus shows the stronger Q vector convergence and PV anomaly passing just north of the forecast area while a dry slot moves into eastern KS by Tuesday morning. With the deeper moisture over far eastern KS, have kept the higher POPs across the east during the early morning hours Tuesday as the shortwave passes by. Prior to this there could be some drizzle develop and spread northeast through the area in response to the stronger low level moisture return. Depending on temps, there could be a brief period of light freezing drizzle. However I expect this to be short lived mainly in the evening as warm air advection should cause temps to rise through the night. Therefore any accumulations should be very minor. Another arctic ridge of high pressure is set to move through the forecast area Tuesday with the GFS trending a little faster with the frontal passage. However with the dry slot in place as the front moves through and upper level forcing likely to the northeast of the forecast area, the front may move through mostly dry through the early afternoon. The forecast anticipates falling temps through the afternoon as cold air moves in behind the front. But for the most part think that any precip on Tuesday is likely to be out ahead of the front and in the form of rain. There are still weak indications of some convective instability Tuesday morning. Because of this have kept a mention for thunder across east central KS. Lows Monday night are forecast to occur early in the evening while highs Tuesday are likely to be measured late in the morning. Tuesday night may be the last chance for precip through the rest of the week. There remains some indication for some mid level frontogenesis along with enough moisture for mid level saturation. The NAM is most bullish with this idea developing several hundredths of precip. While less impressive, the ECMWF also spits out some very light precip. Because of this have continued with a slight chance for snow Tuesday night. However would not anticipate the snow amounting to very much if at all. The upper level trough axis is progged to finally move east of the forecast area Wednesday night. But with dry air moving in with the arctic airmass on Tuesday, precip chances Wednesday and Wednesday night look to be less than 20 percent due to to much dry air. Wednesday is shaping up to be another cold day with lows in the teens and highs in the 20s. Thursday through Saturday continues to look dry with moderating temps as models keep a dry northwest flow over the central plains. By Friday, highs are expected to be in the 50s. This could be a little conservative with the GFS and ECMWF showing 925 MB temps warming to between +5 and +10C. For now stayed with the model consensus and have highs in the lower 50s. && .AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon) Issued at 1134 AM CST SUN MAR 1 2015 For the 12z TAFs, scattered to broken MVFR cigs will persist through the day as the storm system exits east of the area. As surface high pressure moves over the area tonight into Monday, northwesterly winds will veer toward the northeast and eventually to the southeast by the end of the TAF period. && .TOP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY until Noon CST today FOR KSZ058-059. && $$ SHORT TERM...Bowen LONG TERM...Wolters AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS WICHITA KS
1027 AM CST SUN MAR 1 2015 .UPDATE... ISSUED AT 1027 AM CST SUN MAR 1 2015 UPDATED PRECIPITATION CHANCES THROUGH THE EARLY PART OF THE AFTERNOON. WHILE GUIDANCE IS NOT INDICATING MUCH...THE EARLIER RUNS OF THE HRRR SEEMED TO DO THE BEST FOR CURRENT RADAR INDICATIONS AND HAVE TRIED TO FOLLOW THAT FOR THE BEST TRENDS. THINK THAT THE UPPER JET DYNAMICS WILL KEEP SOME LIFT AROUND INTO THE EARLY AFTERNOON HOURS...AT LEAST OVER SOUTHERN AND SOUTHEASTERN KANSAS. THIS WILL PRODUCE A WINTRY MIX OF FREEZING RAIN/SLEET AND SNOW. THIS WILL CAUSE TRAVEL IMPACTS AND THUS HAVE EXTENDED THE WINTER WEATHER ADVISORY UNTIL 20Z FOR MUCH OF THE AREA...CLEARING OUT CENTRAL KANSAS COUNTIES WHERE THE PRECIPITATION HAS ENDED. WILL PLAN TO CLEAR THE ADVISORY FROM WEST TO EAST AS THE PRECIPITATION ENDS AND/OR EXTEND IF NEEDED IF THE WINTRY WEATHER PERSISTS LONGER THAN 20Z. AT THIS TIME FEEL THAT THE BEST CHANCE FOR THAT OCCURRING WOULD BE OVER SOUTHEAST KANSAS...EXPECT CHANCES TO DIMINISH OVER SOUTH CENTRAL KANSAS TOWARDS THE EARLY AFTERNOON HOURS. INCREASED ICE MENTION WITH THE FREEZING RAIN...BUT ONLY A FEW HUNDREDTHS EXPECTED...ICING HAD ALREADY OCCURRED AT THE WICHITA FORECAST OFFICE. SLICK ROADWAYS ARE EXPECTED AS THIS PERSISTS. BILLINGS WRIGHT UPDATE ISSUED AT 735 AM CST SUN MAR 1 2015 HAVE MADE UPDATES TO POPS AND WEATHER OVER THE LAST HOUR. INCREASED PRECIP CHANCES THIS MORNING OVER SOUTH CENTRAL AND SE KS AS RADAR TRENDS CONTINUE TO SHOW RETURNS BUILDING BACK TO THE SOUTHWEST. ALSO TOOK OUT MENTION OF FREEZING DRIZZLE AND ADDED SLEET BASED ON REPORTS AND CURRENT OBS. NOT EXPECTING MUCH IN THE WAY OF ACCUMULATIONS BUT MAYBE JUST ENOUGH TO KEEP ROADWAYS SLICK. SO WILL MAINTAIN THE WINTER WEATHER ADVISORY. LAWSON && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 322 AM CST SUN MAR 1 2015 THERE IS A CHANCE FOR A WEAK MID-LEVEL BAND OF SNOW TO DEVELOP OVER CENTRAL KANSAS INTO EASTERN KANSAS EARLY THIS MORNING...WITH SOME LIGHT SNOW AND LITTLE ACCUMULATION POSSIBLE...MAINLY NEAR THE HIGHWAY 50 CORRIDOR. THE MAIN HAZARD FOR THIS MORNING WILL BE AREAS OF DENSE FREEZING FOG AND PATCHY FREEZING DRIZZLE OVER SOUTH CENTRAL AND SOUTHEAST KANSAS...WHICH COULD CREATE A LIGHT GLAZE ON ELEVATED SURFACES AND UNTREATED ROADWAYS ALONG WITH REDUCED VISIBILITIES TO AROUND ONE QUARTER OF A MILE. DRY WEATHER IS EXPECTED FOR TONIGHT INTO EARLY MONDAY WITH A CHANCE OF OF DRIZZLE POSSIBLY DEVELOPING MONDAY AFTERNOON...AS LOW LEVEL MOISTURE RETURNS NORTHWARD. DAYTIME HIGHS ON MONDAY SHOULD RISE SOME COMPARED TO SUNDAY`S HIGHS BUT VALUES WILL STILL BE WELL BELOW NORMAL FOR EARLY MARCH...ESPECIALLY FOR THE SNOW COVERED AREAS. CHANCES OF RAIN LOOK TO INCREASE FOR EASTERN KANSAS ON MONDAY NIGHT INTO TUESDAY...WITH A FEW WEAK ELEVATED THUNDERSTORMS POSSIBLE OVER FAR SOUTHEAST KANSAS. THE ARCTIC COLD FRONT WILL SURGE SOUTHWARD ACROSS KANSAS DURING THE DAY ON TUESDAY...WITH FALLING TEMPERATURES IN THE AFTERNOON ACCOMPANIED BY STRONG GUSTY NORTH WINDS. THE COLDER AIR WOULD CHANGE THE PRECIPITATION OVER TO A RAIN SNOW MIXTURE FOR CENTRAL KANSAS TUESDAY AFTERNOON...WITH CHANCES OF LIGHT SNOW FOR TUESDAY NIGHT. AT THIS JUNCTURE SNOW ACCUMULATIONS ARE LOOKING RATHER LOW FOR TUESDAY NIGHT. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 322 AM CST SUN MAR 1 2015 OTHER THAN SOME POSSIBLE LINGERING LIGHT SNOW FOR SOUTHEAST KANSAS WEDNESDAY MORNING THE BETTER CHANCES SHOULD BE FOR LOCATIONS SOUTHEAST OF THE AREA. DAYTIME HIGHS ON WEDNESDAY WILL BE WELL BELOW NORMAL ESPECIALLY FOR SNOW COVER AREAS ACROSS SOUTHERN KANSAS. OTHERWISE...A DRY WEATHER PATTERN WILL BE IN STORE FOR THURSDAY- SATURDAY WITH A GRADUAL WARMING TREND FOR FRIDAY INTO THE WEEKEND. JAKUB && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 530 AM CST SUN MAR 1 2015 MAIN AVIATION CONCERNS WILL BE FOG AND LOW CEILINGS THIS MORNING. LOCALLY DENSE FOG DEVELOPED OVERNIGHT OVER MAINLY SOUTH CENTRAL KS. KICT WAS THE MOST AFFECTED WITH LIFR VISIBILITIES AND CEILINGS. CONDITIONS HAVE STARTED TO SLOWLY IMPROVE OVER THE LAST HALF HOUR AND WOULD EXPECT THIS TO CONTINUE. HOWEVER...STILL EXPECTING AT LEAST IFR CONDITIONS THIS MORNING AT KICT-KHUT. SOME LIGHT SNOW/SLEET IS QUICKLY MAKING ITS WAY ACROSS SOUTH CENTRAL AND SE KS AND WILL BE OUT OF THE FORECAST AREA IN THE NEXT HOUR. NOT EXPECTING ANY ACCUMULATION WITH THIS. HIGH PRESSURE IS EXPECTED TO SETTLE OVER THE AREA LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS WHICH WILL ALLOW VFR CONDITIONS TO MOVE BACK IN. LAWSON && .FIRE WEATHER... ISSUED AT 322 AM CST SUN MAR 1 2015 FIRE WEATHER CONCERNS WILL REMAIN VERY LOW FOR THE NEXT SEVERAL DAYS DUE TO SNOW COVER BLANKETING MUCH OF THE AREA...ALONG WITH RAIN CHANCES FOR MONDAY NIGHT INTO TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 31 20 35 34 / 50 10 20 30 HUTCHINSON 32 20 34 33 / 30 10 20 30 NEWTON 30 19 34 34 / 70 10 20 30 ELDORADO 30 20 35 34 / 50 10 20 40 WINFIELD-KWLD 31 21 36 35 / 50 10 20 40 RUSSELL 33 18 37 34 / 10 10 20 20 GREAT BEND 33 19 37 34 / 10 10 20 20 SALINA 34 20 36 33 / 20 10 20 30 MCPHERSON 32 19 35 33 / 30 10 20 30 COFFEYVILLE 33 22 37 36 / 40 10 20 60 CHANUTE 31 21 36 35 / 40 10 20 60 IOLA 31 20 36 35 / 50 10 20 60 PARSONS-KPPF 32 22 36 35 / 40 10 20 60 && .ICT WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR KSZ053- 067>072-082-083-091>096-098>100. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
104 PM EST SUN MAR 1 2015 .UPDATE... ISSUED AT 1253 PM EST SUN MAR 1 2015 ENDED UP EXTENDING THE WSW AND SPS FOR FREEZING RAIN POTENTIAL TO 11AM THIS MORNING BASED ON THE CURRENT /AT THE TIME/ TEMPERATURES ACROSS THE CWA...AND REPORTS OF CONTINUED SLICK SPOTS ON AREA ROADWAYS. TEMPERATURES IN MOST AREAS WITHIN THE WSW OR SPS CONTINUED TO RISE THROUGHOUT THE MORNING...AND WERE SEVERAL DEGREES ABOVE FREEZING BY THE EXPIRATION OF THE HEADLINES...SO HAD NO NEED TO CONTINUE THE WSW OR SPS ANY LONGER. DURING THE INITIAL EXTENSION OF THE PRODUCTS...ALSO WENT IN AND UPDATED THE WEATHER IN THE FORECAST TO REFLECT THE POSSIBILITY OF FREEZING RAIN IN VALLEY LOCATIONS WITHIN THE WSW AREA. THIS HAS SINCE FALLEN OUT OF THE FORECAST AS WELL. CURRENTLY...A DECENT BAND OF PRECIPITATION IS CONTINUING ACROSS THE NORTHERN CWA...AND MOVING INTO THE SOUTHWESTERN CWA. THIS MATCHES UP WELL WITH THE UPDATED FORECAST FROM A FEW HOURS AGO. WITH TEMPERATURES WELL ABOVE FREEZING AT THIS POINT...EXPECT ALL OF THIS PRECIPITATION TO CONTINUE IN THE FORM OF LIGHT RAIN. WILL BE LOADING IN THE LATEST OBSERVATIONAL DATA AT THE TOP OF THE HOUR FOR TEMPS...DEW POINTS...AND WINDS...TO MAKE SURE THAT THE NEAR TERM FORECAST IS ON TRACK WITH THE ONGOING CONDITIONS. UPDATE ISSUED AT 647 AM EST SUN MAR 1 2015 CONDITIONS ACROSS EASTERN KENTUCKY THIS MORNING FEATURED SOME SHOWERS DEVELOPING OVER FAR EASTERN KENTUCKY AS THE DEVELOPING LL JET RESULTED IN THIS DEVELOPMENT. REPORTS OVER NEAR PIKEVILLE THIS MORNING RELAYED SOME LIGHT FREEZING RAIN REPORTS WITH SOME SLICKNESS DEVELOPED ON SECONDARY ROADS. GIVEN THE INTENSITY OF THE RAIN AND THE SATURATED LOWER LEVELS IN THE FAR EAST...SENT OUT AN FREEZING RAIN ADVISORY FOR THIS. THESE DEEPER VALLEYS IN THE EAST WILL LIKELY TAKE UNTIL MID MORNING TO MIX OUT. NO REPORTS HAVE BEEN SEEN IN THE NORTHWEST AND BLUEGRASS REGION AND GIVEN THE SURGE OF WARM AIR COUPLED WITH THE CONTINUED DEW POINT DEPRESSIONS WILL CONTINUE TO HIGHLIGHT THIS AREA WITH THE SPS MENTIONING SOME LIGHT WINTRY WEATHER THIS MORNING. TEMPS SHOULD ALSO RISE QUITE QUICKLY THIS MORNING AS THE WARMER SOUTHWESTERLY AIR ADVECTS INTO THE AREA. HAVE SENT OUT A NEW ZFP WITH THE WSW HIGHLIGHTED. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 345 AM EST SUN MAR 1 2015 CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC. AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY THIS SUNDAY MORNING. HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 345 AM EST SUN MAR 1 2015 MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION LATE SATURDAY NIGHT...EARLY SUNDAY MORNING. NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST +5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE ONSET OF PRECIPITATION. OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST LOCATIONS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 104 PM EST SUN MAR 1 2015 LIGHT RAIN SHOWERS CONTINUE ACROSS CENTRAL AND NORTHEAST KY AT THIS TIME...WITH ALMOST EVERY TAF SITE BEING IMPACTED. SO FAR THE RAIN REMAINS FAIRLY LIGHT...WITH ONLY MVFR RESTRICTIONS TO VIS. THE HEAVIEST RAIN WILL CONTINUE TO BE ACROSS THE NORTHERN FORECAST AREA...WITH KSYM POSSIBLY SEEING SOME TEMPORARILY DROPS DOWN TO IFR VIS CONDITIONS IN SOME OF THE HEAVIER BURSTS. OVERALL...MOST OF CENTRAL AND EASTERN KY CONTINUES TO SEE MVFR SKIES...AND EXPECT THIS TO CONTINUE THROUGH AT LEAST THIS EVENING. WOULDN/T BE SURPRISED IF WE DROPPED TO IFR LATER ON TONIGHT AS WE SEE SOME OF OUR BEST SATURATION. THERE IS STILL THE POTENTIAL THAT SOME SNOW COULD MIX IN WITH THE RAIN ON THE BACK SIDE OF THIS SYSTEM...JUST BEFORE TAPERING OFF SOON AFTER. TRIED TO TIME THIS OUT IN THE FORECAST...WITH MOST OF THE SNOW EXPECTED TO BE AFTER AROUND 6-7Z. PRECIP WILL BE ENDING SOMETIME TOMORROW MORNING...WITH SKIES SLOWLY BREAKING UP DURING THE DAY. WINDS WILL SHIFT BACK TO A MORE NW TO NRLY DIRECTION...BUT SHOULD GENERALLY REMAIN BELOW 10KTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...SHALLENBERGER LONG TERM...AR AVIATION...JMW
AREA FORECAST DISCUSSION
NWS CARIBOU ME
337 PM EST SUN MAR 1 2015 .SYNOPSIS... LOW PRESSURE WILL APPROACH THE REGION FROM OHIO VALLEY THIS EVENING AND MOVING THROUGH THE REGION LATER TONIGHT INTO MONDAY. THIS SYSTEM WILL BRING SOME SNOW TO THE FORECAST AREA. HIGH PRESSURE WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM THE WEST. ANOTHER LOW WILL CROSS THE REGION WEDNESDAY. && .NEAR TERM /THROUGH MONDAY/... THINGS TO FOCUS ON THIS TERM WILL BE SNOWFALL AMOUNTS AND SNOW SQUALL POTENTIAL ON MONDAY. 18Z SURFACE ANALYSIS SHOWED HIGH PRES S OF THE REGION RIDGING ACROSS THE STATE OF MAINE. MID AND HIGH CLOUDS MOVING NE PER THE LATEST SATELLITE IMAGERY WILL CAP ANY FURTHER PROGRESSION OF TEMPERATURES THIS AFTERNOON. READINGS ACROSS NORTHERN AND WESTERN AREAS HIT THE MID/UPPER 20S WHILE CENTRAL AND DOWNEAST CLOSED IN AROUND 30. TEMPERATURES WILL FALL BACK AFTER SUNSET BUT W/THE CLOUDS MOVING IN, ANY FURTHER DROP WILL BE SLOW OR EVEN READINGS LEVELING OFF ESPECIALLY DOWNEAST AND THE COAST. NORTHERN AREAS COULD SEE TEMPERATURES FALL OFF QUICKER AS INITIAL CLOUD SHIELD IS THIN PER THE OBS. SNOW IS FORECAST TO BREAK OUT ACROSS THE SOUTHERN AND DOWNEAST AREAS THIS EVENING. THE LATEST RUNS OF THE RAP AND HRRR 3KM DOING WELL PER THE RADAR TRENDS AND METARS. THIS SET OF GUIDANCE SHOWS SNOW SETTING UP LATER THAN PREVIOUSLY EXPECTED. THEREFORE, PULLED BACK ON THE TIMING BY A FEW HRS. LOW PRES MOVING E FROM THE OHIO VALLEY IS SHOWN BY THE MODEL GUIDANCE TO RE-DEVELOP OFF THE MAINE COAST LATER TONIGHT W/AN INVERTED TROF SETTING UP FOR A TIME ACROSS EASTERN SECTIONS. SOME FORCING IS THERE AND W/TEH LLVL CONVERGENCE, THERE COULD BE A BRIEF PERIOD OF MODERATE SNOW WHERE RATIOS OF 15-20:1 COULD BE REALIZED W/2-4 INCHES OF SNOW FROM 06-12Z. THE HIGHEST SNOWFALL WILL BE ACROSS THE COAST AND GIVEN THE 3-4 INCH AMOUNTS SHOWN, DECIDED TO ISSUE A WINTER WEATHER ADVISORY FOR SNOW. THIS WAS COORDINATED W/GYX. FURTHER N AND W, SNOWFALL AMOUNTS WILL DROP OFF AS DYNAMICS WILL BE WEAKER W/A GENERAL 1-3 INCHES AT BEST. FOR MONDAY, SNOWFALL WILL COME TO AN END QUICKLY ACROSS THE W AND DOWNEAST REGION WHILE EASTERN AREAS INCLUDING EASTERN SECTION OF AROOSTOOK COUNTY WILL HANG ON TO A PERIOD OF SNOW THROUGH 10 AM OR SO. THINGS WILL TRANSITION TO A MORE SHOWERY NATURE FOR THE SNOW W/A GOOD CHANCE FOR SOME SNOW SQUALLS. THE NAM AND GFS SOUNDINGS POINT TO STEEPENING LAPSE RATES(6/5-7.0C/KM) AT 850-700MBS AND FORECAST CAPE OF 70+ JOULES. THIS WILL BE IN ASSOCIATION W/AN ARCTIC FRONT THAT IS FORECAST TO SLIDE ACROSS THE REGION MONDAY AFTERNOON. THE BTV SNOW SQUALL PARAMETER SHOWED 2 AREAS OF SQUALL POTENTIAL W/ONE ACROSS NORTHERN AND WESTERN AREAS AND THE SECOND AREA ACROSS EASTERN MAINE. TEMPERATURES WILL DROP OFF SHARPLY BEHIND THIS BOUNDARY AFTER 19Z(2 PM). A QUICK INCH OF SNOW CAN BE EXPECTED W/THE SQUALLS ALONG W/WIND GUSTS UP TO 30 MPH. THIS SITUATION IS SIMILAR TO THE SQUALL EVENT THAT OCCURRED A WEEK AGO(2/23)WHERE MOIST OFF THE OPEN ST. LAWRENCE COMBINED W/THE FRONT AIDING IN SOME HEFTY SNOW SQUALLS/SNOW SHOWERS. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... THE MAIN FORECAST CONCERN FOR THE SHORT TERM IS A QUICK MOVING SHORTWAVE WHICH WILL AFFECT MOST OF NEW ENGLAND TUESDAY NIGHT INTO WEDNESDAY. THE COMBINATION OF DPVA AND WAA WILL PROVIDE SUFFICIENT LIFT TO PRODUCE LIGHT TO MODERATE SNOW ACROSS OUR CWA DURING THIS TIME FRAME...WITH CONDITIONS EXPECTED TO DRY OUT QUICKLY WEDNESDAY AFTERNOON. HAVE FOLLOWED CLOSELY TO CONSALL QPF WHICH RESULTS IN A GENERAL 3 TO 5 INCHES OF SNOWFALL. THE HIGHEST AMOUNTS WILL OCCUR DOWNEAST...BUT WITH TEMPS IN THE LOWER 40S WEDNESDAY AFTERNOON...MUCH OF THE SNOW WILL COMPACT OR MELT. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE UPPER LEVEL FLOW WILL BECOME ZONAL AND PROGRESSIVE DURING THE EXTENDED FORECAST PERIOD...BRINGING A SERIES OF VERY WEAK SHORTWAVES ACROSS THE NORTHEAST. THIS WILL RESULT IN SEASONABLY COLD CONDITIONS WITH OCCASIONAL SNOW SHOWERS. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... NEAR TERM: VFR DROPPING TO MVFR LATER THIS EVENING AND THEN IFR OVERNIGHT FOR ALL TERMINALS. CONDITIONS ARE FORECAST TO IMPROVE TO VFR FOR KBGR AND KBHB MIDDAY MONDAY W/THE NORTHERN TERMINALS GOING FROM IFR TO MVFR. SHORT TERM: MVFR TO IFR CONDITIONS SHOULD PREVAIL ACROSS THE CWA TUESDAY NIGHT INTO WEDNESDAY MORNING IN ASSOCIATION WITH THE AFOREMENTIONED SNOWFALL. CONDITIONS WILL IMPROVE WEDNESDAY AFTERNOON. && .MARINE... NEAR TERM: PER COORDINATION W/GYX, DECIDED TO GO W/A GALE WARNING FOR MONDAY AFTERNOON INTO THE EVENING DUE TO THE ARCTIC FRONT MOVING ACROSS THE WATERS. NW WINDS W/CAA WILL ALLOW FOR WINDS TO HIT 25 TO 30 W/GUSTS UP TO 35 KTS. BUFKIT PROFILES SHOW GUST POTENTIAL TO 40 KTS OVER THE OUTER WATERS. MIDNIGHT CREW HAD THIS HANDLED WELL AND STAYED CLOSE TO IT. SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY BE NEED FOR OUR COASTAL MARINE ZONES TUESDAY NIGHT INTO WEDNESDAY AS STORM SYSTEMS CROSSES THE AREA...CREATING BREEZY SOUTHWEST WINDS AND HIGH WAVES. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST MONDAY FOR MEZ029-030. MARINE...GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR ANZ050>052. && $$ NEAR TERM...HEWITT SHORT TERM...BERDES LONG TERM...BERDES AVIATION...HEWITT/BERDES MARINE...HEWITT/BERDES
AREA FORECAST DISCUSSION
NWS CARIBOU ME
127 PM EST SUN MAR 1 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST OF THE REGION THIS AFTERNOON. LOW PRESSURE WILL CROSS THE REGION TONIGHT INTO MONDAY. HIGH PRESSURE WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM THE WEST. ANOTHER LOW WILL CROSS THE REGION WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... 115 PM UPDATE...FIRST BATCH OF CLOUDS PULLING EASTWARD PER THE LATEST SATELLITE LOOP W/SOME PARTIAL CLEARING. THIS WILL ALLOW FOR SOME WARMING INTO LATE AFTERNOON. ANOTHER AREA OF CLOUDS ASSOCIATED W/THE STORM SYSTEM MOVING INTO THE OHIO VALLEY SET TO ADVANCE INTO THE REGION. THEREFORE ADJUSTED MAX TEMPS UP A FEW DEGREES W/SOME NORTHERN AREAS HITTING THE UPPER 20S AND DOWNEAST TOPPING 30F. REGIONAL RADAR LOOP SNOW SOME PRECIP(LIGHT) MOVING ACROSS SOUTHERN NEW ENGLAND TOWARD SOUTHERN MAINE. THE MORE SIGNIFICANT PRECIP WAS MOVING ACROSS LONG ISLAND. THE RAP AND HRRR 3KM MODELS WERE DOING WELL W/THIS SETUP W/DRY CONDITIONS INTO EARLY EVENING. SNOW EXPECTED TO DEVELOP LATER IN THE EVENING ACROSS THE SW AND DOWNEAST AND SPREAD NE OVERNIGHT INTO MONDAY. MORE ON THIS LATER. A LOW PRESSURE SYSTEM WILL DEEPEN SIGNIFICANTLY AS IT CROSSES THE GULF OF MAINE OVERNIGHT ENROUTE TO HALIFAX. THE FORECAST AREA WILL RECEIVE A GLANCING BLOW FROM THE STORM WITH THE BEST QPF ALONG THE WASHINGTON COUNTY COAST WHERE THREE- TENTHS OF AN INCH IS EXPECTED. WITH SNOW-WATER RATIOS GENERALLY AROUND 15 TO 1 OR HIGHER...THIS TRANSLATES TO A NARROW SWATH OF 4-6 INCHES POSSIBLE FOR HARD-HIT MACHIAS AND EASTPORT AS WELL AS MDI. AMOUNTS WILL TAPER TO THE NORTH SUCH JUST AN INCH IS FORECAST FOR FORT KENT AND MADAWASKA. WITH ADVISORY CRITERIA AT 4 INCHES...WILL HOLD OFF ON ANY WINTER WEATHER HEADLINES UNTIL LATER TODAY. && .SHORT TERM /MONDAY/... LOW PRESSURE IN THE GULF OF MAINE MONDAY MORNING WILL MOVE AWAY TO THE NORTHEAST. STRONG HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST MONDAY NIGHT AND CREST OVER THE STATE TUESDAY. EXPECT SNOW TO END LATE MONDAY AS LOW PRESSURE MOVES AWAY. WILL USE A MODEL CONSENSUS APPROACH AND BLEND THE NAM... GFS AND ECMWF FOR POP... SKY AND QPF. HAVE USE THE OFFICE SNOW FROM THICKNESS TOOL FOR SNOW ACCUMULATIONS. WILL USE THE NAM12 FOR WINDS. FOR TEMPERATURE AND DEW POINT HAVE USED THE SUPER BLEND. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE WILL MOVE TO THE EAST TUESDAY NIGHT AS LOW PRESSURE APPROACHES FROM THE WEST. THIS SYSTEM IS EXPECTED TO PASS TO THE NORTHWEST OF THE STATE WEDNESDAY MORNING. THE TRACK OF THE LOW WILL RESULT IN SNOW CHANGING TO RAIN ACROSS SOUTHERN AND CENTRAL AREAS AS WARM AIR ADVECTION TAKES PLACE AHEAD OF THE LOW. COLD AIR WILL RETURN AS THE LOW PASSES TO THE NORTH LATE WEDNESDAY AND WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST THURSDAY. WILL USE THE SUPER BLEND TO POPULATE GRIDS. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... NEAR TERM: VFR TODAY AND INTO EARLY SUNDAY EVENING. IFR TONIGHT IN SNOW FOR ALL SITES. LIFR POSSIBLE FOR SEVERAL HOURS AT BGR AND BHB. SHORT TERM: EXPECT IFR/MVFR CONDITIONS TO TRANSITION TO VFR MONDAY. VFR CONDITIONS EXPECTED MONDAY NIGHT AND TUESDAY. IFR CONDITIONS EXPECTED TUESDAY NIGHT AND WEDNESDAY. EXPECT VFR CONDITIONS THURSDAY. && .MARINE... NEAR TERM: WINDS WILL INCREASE TO SCA LEVELS THIS EVENING IN THE OUTER WATERS THEN DECREASE AGAIN AFTER MIDNIGHT. WITH THE GALE WATCH OUT...HAVE ELECTED NOT TO CREATE A SECOND HEADLINE. SHORT TERM: FOR SUSTAINED WINDS WILL USE THE NAM12. FOR WAVES: EXPECT OFF-SHORE WIND WAVE TO DOMINATE MONDAY WITH WAVE HEIGHTS DEPENDENT ON FETCH DISTANCE OFF-SHORE. SOUTHERLY WIND WAVE WILL BUILD TUESDAY NIGHT INTO WEDNESDAY AS LOW PRESSURE PASS TO THE NORTHWEST OF THE REGION. WILL USE THE NEAR SHORE WAVE MODEL FOR WAVE GRIDS THROUGH TUESDAY THEN TRANSITION TO THE WW III. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR ANZ050>052. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
423 PM EST SUN MAR 1 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 422 PM EST SUN MAR 1 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM HUDSON BAY INTO THE NRN PLAINS. WITHIN TROF...NEXT SHORTWAVE OF INTEREST IS NOW OVER THE DAKOTAS/MN. CLOSER TO HOME...SOME -SHSH/FLURRIES HAVE SPREAD FROM WRN UPPER MI INTO PORTIONS OF CNTRL UPPER MI TODAY IN VCNTY OF SFC TROF WHICH IS NOW ROUGHLY BISECTING UPPER MI. TONIGHT...SHORTWAVE NOW OVER THE DAKOTAS WILL SWING ACROSS THE WRN GREAT LAKES THIS EVENING. AREA OF DEEP LAYER FORCING PER QVECTORS SHIFTS ACROSS UPPER MI LATE THIS AFTN AND EVENING. WITH ASSOCIATED BRIEF PERIOD OF DEEP MOISTURE...850MB TEMPS AROUND -18C...AND A ROUGHLY 3KFT DGZ LAYER BTWN ROUGHLY 2K AND 5KFT...WOULD NORMALLY BE CONCERNED ABOUT SEEING SEVERAL HRS OF HEALTHY LAKE ENHANCED SNOW IF THE LAKE WASN`T MOSTLY ICE COVERED. THAT SAID...THE BRISK SW TO W WINDS OF THE LAST COUPLE OF DAYS HAVE OPENED UP SOME NOTABLE GAPS IN THE ICE...SO THERE WILL BE AN OPPORTUNITY FOR LOCALIZED MORE PERSISTENT LES AND SOME SNOW ACCUMULATION. FROM TODAYS MODIS AND VIS SATELLITE IMAGERY...A COUPLE OF IMPORTANT GAPS IN THE ICE ARE NOTED FROM AROUND THE HURON ISLANDS DOWN PAST GRANITE ISLAND AND OVER TO N OF MUNISING...AND ALSO IN THE AREA E OF THE APOSTLE ISLANDS WHICH HAS CERTAINLY HAD A TENDENCY TO OPEN UP OVER THE LAST FEW WEEKS WHEN WINDS ARE SW. WILL THUS HIT HIGHEST POPS AND 1-2 INCHES OF SNOW DOWNWIND OF THESE OPEN WATER AREAS THIS EVENING (JUST N OF IRONWOOD TO THE PORCUPINE MTNS AND ALSO ALGER COUNTY). STRONG NEGATIVE DYNAMICS TAKE OVER DURING THE OVERNIGHT...SO LES INTENSITY WILL DIMINISH RATHER QUICKLY AFTER MIDNIGHT. AWAY FROM THESE AREAS... WNW/NW FLOW LES SHOULD BE NO MORE THAN SCT WITH ACCUMULATIONS UNDER 1 INCH. ELSEWHERE...EXPECT SOME FLURRIES IN MOST AREAS AS SHORTWAVE PASSES. TEMPS IN THE INTERIOR W TOWARD THE WI BORDER SHOULD FALL DOWN TOWARD ZERO WITH CLEARING SKIES OVERNIGHT. OTHERWISE...MIN TEMPS SHOULD BE WITHIN A FEW DEGREES OF 10F. ANY LINGERING LES TO THE E OF MARQUETTE WILL END BY MON AFTN UNDER WAA/BACKING WINDS WITH PASSAGE OF SFC HIGH PRES RIDGE (BY MID AFTN 850MB TEMPS ARE FCST TO BE AROUND -12C). WHILE THERE MAY BE SOME STRATOCU DEVELOPMENT EVEN WHERE SKIES ARE CLEAR TO START THE DAY...EXPECT ALL AREAS TO BECOME SUNNY DURING THE DAY WITH DRY AIR MASS AND DEPARTURE OF 850MB THERMAL TROF. HIGH TEMPS WILL RANGE FROM AROUND 20 TO THE UPPER 20S...COOLEST OVER THE FAR E...CLOSER TO DEPARTING THERMAL TROF. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 310 PM EST SUN MAR 1 2015 ...WIDESPREAD SNOW TUESDAY MAY EVENTUALLY NEED A HEADLINE... PRIMARY HIGHER IMPACT WEATHER THROUGH THE NEXT WEEK IS LIMITED TO WIDESPREAD SNOW EXPECTED TO AFFECT THE AREA ON TUESDAY AND TUESDAY EVENING. OTHERWISE...WARM UP EARLY IN THE WEEK WILL BE REPLACED BY A COOL DOWN WEDNESDAY INTO THURSDAY IN WAKE OF THE TUESDAY SYSTEM. MAY BE SOME LAKE EFFECT WEDNESDAY AND WEDNESDAY NIGHT BUT CHANCES WILL BE HELD DOWN AS LAKE SUPERIOR REMAINS MOSTLY ICE COVERED. TEMPS REBOUND AGAIN BY NEXT FRIDAY AND COULD STAY AT SIMILAR LEVELS INTO NEXT WEEKEND. HIGH PRESSURE EXITS EAST ON MONDAY EVENING WITH CLOUDS INCREASING THROUGH THE NIGHT AHEAD OF A TWO-PIECED LOW PRESSURE SYSTEM HEADING TOWARD REGION. NORTHERN STREAM WAVE AND ITS ASSOCIATED LOW SLIDES FM NORTHERN MANITOBA TO NORTHERN ONTARIO BY DAYBREAK ON TUESDAY. MEANWHILE THE SOUTHERN STREAM WAVE WILL PUSH OVER THE CENTRAL PLAINS AS THE SFC LOW ARRIVES ALONG THE NEB/IOWA BORDER. MOISTURE ADVECTION AHEAD OF THE LOW-MID LEVEL TROUGH MAXIMIZES OVERNIGHT BTWN H85 AND H5. LIFT IS PRETTY STRONG WITHIN THE MOIST ADVECTION...SO SHOULD SEE LGT SNOW BEGIN TO DEVELOP AFTER MIDNIGHT TOWARD WI BORDER WITH LOWEST 100MB GRADUALLY SATURATING. HINTS ARE THERE THAT THE INITIAL SNOW COULD BE DRIVEN BY FGEN...BUT WHERE MAX RIBBON OF HEAVIER SNOW SETS UP IS NOT CERTAIN. 12Z NAM SHOWS IT MORE OVER WESTERN CWA...BUT THIS IS AT ODDS WITH NAM DOMINATED SREF OUTPUT AND SEEMS TOO FAR NORTH AS IT IS ALSO FARTHER NORTH WITH SOUTHERN STREAM SFC LOW ON INTO TUESDAY. WILL KEEP WITH IDEA OF HEAVIER QPF/SNOW ON TUESDAY ON EDGE OF GREATER H85-H7 MOISTURE TRANSPORT WHICH MAINLY IS MAXIMIZED JUST TO THE SOUTH AND SOUTHEAST OF UPR MICHIGAN OUT AHEAD OF SOUTHERN STREAM SFC LOW CROSSING LOWER MICHIGAN. H7 MIXING RATIOS GFS/ECMWF STAY BLO 3G/KG THROUGHOUT TUESDAY. MIXING RATIOS INTO THE SYSTEM AND BLEND OF QPF FM GFS/ECMWF ALONG WITH SLR/S CENTERED ON 15:1...SUGGEST ADVY LEVEL SNOWFALL SCNTRL CWA INTO THE EASTERN CWA. WILL CONTINUE TO MENTION IN HWO/EHWO GRAPHICS. PHASING BTWN THE NORTHERN STREAM WAVE AND SOUTHERN STREAM WAVES NEVEN REALLY TAKES OFF SO THIS SYSTEM SHOULD STAY PROGRESSIVE ON TUESDAY NIGHT AS MAIN CORE OF UPPER JET ENERGY STAYS OUT AHEAD OF THE TROUGH. CHANCE POPS LINGER EARLY TUESDAY EVENING IN THE EAST...BUT OTHERWISE POPS WITH THE SYSTEM WILL BE OUT OF THE AREA. INITIALLY LAKE EFFECT IN WAKE OF THE SYNOPTIC SNOW ON TUESDAY EVENING PROBABLY STAYS ON THE LIGHT SIDE DUE TO MARGINALLY COLD AIR /H85 TEMPS WARMER THAN -15C/ AND MAINLY ICE COVERED LAKE SUPERIOR. GFS SOUNDINGS SHOW INCREASE OF MOISTURE H8-H7 LATE TUESDAY NIGHT INTO WEDNESDAY WHILE COLD AIR ADVECTION WITH H85 TEMPS FALLING BLO -20C OVER LK SUPERIOR RESULTS IN INVERSIONS RISING UP TO A MAX OF 8KFT WEDNESDAY MORNING OVER EASTERN LK SUPERIOR. DESPITE THE HIGH ICE COVERAGE...SCT POPS FOR LAKE EFFECT SNOW SHOWERS AND ALSO FARTHER DOWNSTREAM OVER LAND AREAS WITH SOME HELP FM DAYTIME HEATING AS THE HYBRID LAKE EFFECT SEASON IS UNDERWAY DUE TO HIGHER SUN ANGLE. WITH NW WINDS UP TO 30 MPH ALONG THE LK SUPERIOR SHORELINES...PROBABLY WILL HAVE BLSN/POOR VSBY IN THE SNOW BELTS NEAR LK SUPERIOR EAST OF MQT. EVEN MINUS BLSN...LES WILL BE GOOD AT REDUCING VSBY AS THE SNOWFLAKES WILL BE BECOMING SMALLER. H85 TEMPS CONTINUE TO FALL BLO -25C BY LATE IN THE DAY ON WEDNESDAY...SO TEMPS WILL BE STEADY OR SLOWLY FALL THROUGH THE DAY. ARRIVAL OF HIGH PRESSURE RIDGE AND WINDS BACKING W-WSW BY THURSDAY MORNING WILL DIMINISH ANY SNOW SHOWERS AS WINDS BECOME MORE OFFSHORE. TEMPS OVER MUCH OF THE INTERIOR ON WEDNESDAY NIGHT COULD TANK WELL UNDER 10 BLO ZERO. MAY SEE MARGINALLY LOW WIND CHILLS ON THURSDAY MORNING...BUT FARTHER INLAND WHERE TEMPS WILL BE COLDEST EXPECT THE WINDS TO BE NEARLY CALM. STILL COLD ON THURSDAY AS CORE OF COLDER TEMPS ALOFT SLOWLY HEADS ACROSS EASTERN CANADA. WARM FRONT MOVES TOWARD UPPER LAKES THURSDAY NIGHT INTO FRIDAY MORNING. WARMING FIRST OCCURS ALOFT THEN MAKES ITS WAY TO SFC BY FRIDAY AFTN. GFS SOUNDINGS SHOW MID LEVEL MOISTURE QUICKLY SWEEPS ACROSS LEAVING SCT-BKN LOW CLOUDS LATER ON FRIDAY. MOISTURE AND LIFT DOES NOT SYNC UP...SO NOT EXPECING MUCH IN WAY OF LGT SNOW. BETTER LINKING OF LOW AND MID LEVEL MOISTURE IS OVER NORTHERN LK SUPERIOR AND NORTHERN ONTARIO. DECENT AGREEMENT IN THIS IDEA FM GFS AND ECMWF. COLD AIR NOT AS EMPHATIC FOR NEXT WEEKEND WITH GFS AND ECMWF SHOWING H85 TEMPS MAINLY WARMER THAN -12C. GIVEN THE RUN-TO-RUN DIFFERENCES IN MODELS AND DIFFERENCES IN MODEL SOLUTIONS...WILL JUST RUN WITH CONSENSUS FRIDAY THROUGH SUNDAY. RESULT IS DAYTIME TEMPS IN THE 20S TO NEAR 30 DEGREES AND ONLY SMALL CHANCES OF LGT SNOW MAINLY OVER THE NORTH AND EAST CWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1245 PM EST SUN MAR 1 2015 SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW FLOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 310 PM EST SUN MAR 1 2015 SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY. STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR. OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS. LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
316 PM EST SUN MAR 1 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM EST SUN MAR 1 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS. MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN. MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE DISTURBANCES. TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE 25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL. TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85 THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN THAT AREA. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 310 PM EST SUN MAR 1 2015 ...WIDESPREAD SNOW TUESDAY MAY EVENTUALLY NEED A HEADLINE... PRIMARY HIGHER IMPACT WEATHER THROUGH THE NEXT WEEK IS LIMITED TO WIDESPREAD SNOW EXPECTED TO AFFECT THE AREA ON TUESDAY AND TUESDAY EVENING. OTHERWISE...WARM UP EARLY IN THE WEEK WILL BE REPLACED BY A COOL DOWN WEDNESDAY INTO THURSDAY IN WAKE OF THE TUESDAY SYSTEM. MAY BE SOME LAKE EFFECT WEDNESDAY AND WEDNESDAY NIGHT BUT CHANCES WILL BE HELD DOWN AS LAKE SUPERIOR REMAINS MOSTLY ICE COVERED. TEMPS REBOUND AGAIN BY NEXT FRIDAY AND COULD STAY AT SIMILAR LEVELS INTO NEXT WEEKEND. HIGH PRESSURE EXITS EAST ON MONDAY EVENING WITH CLOUDS INCREASING THROUGH THE NIGHT AHEAD OF A TWO-PIECED LOW PRESSURE SYSTEM HEADING TOWARD REGION. NORTHERN STREAM WAVE AND ITS ASSOCIATED LOW SLIDES FM NORTHERN MANITOBA TO NORTHERN ONTARIO BY DAYBREAK ON TUESDAY. MEANWHILE THE SOUTHERN STREAM WAVE WILL PUSH OVER THE CENTRAL PLAINS AS THE SFC LOW ARRIVES ALONG THE NEB/IOWA BORDER. MOISTURE ADVECTION AHEAD OF THE LOW-MID LEVEL TROUGH MAXIMIZES OVERNIGHT BTWN H85 AND H5. LIFT IS PRETTY STRONG WITHIN THE MOIST ADVECTION...SO SHOULD SEE LGT SNOW BEGIN TO DEVELOP AFTER MIDNIGHT TOWARD WI BORDER WITH LOWEST 100MB GRADUALLY SATURATING. HINTS ARE THERE THAT THE INITIAL SNOW COULD BE DRIVEN BY FGEN...BUT WHERE MAX RIBBON OF HEAVIER SNOW SETS UP IS NOT CERTAIN. 12Z NAM SHOWS IT MORE OVER WESTERN CWA...BUT THIS IS AT ODDS WITH NAM DOMINATED SREF OUTPUT AND SEEMS TOO FAR NORTH AS IT IS ALSO FARTHER NORTH WITH SOUTHERN STREAM SFC LOW ON INTO TUESDAY. WILL KEEP WITH IDEA OF HEAVIER QPF/SNOW ON TUESDAY ON EDGE OF GREATER H85-H7 MOISTURE TRANSPORT WHICH MAINLY IS MAXIMIZED JUST TO THE SOUTH AND SOUTHEAST OF UPR MICHIGAN OUT AHEAD OF SOUTHERN STREAM SFC LOW CROSSING LOWER MICHIGAN. H7 MIXING RATIOS GFS/ECMWF STAY BLO 3G/KG THROUGHOUT TUESDAY. MIXING RATIOS INTO THE SYSTEM AND BLEND OF QPF FM GFS/ECMWF ALONG WITH SLR/S CENTERED ON 15:1...SUGGEST ADVY LEVEL SNOWFALL SCNTRL CWA INTO THE EASTERN CWA. WILL CONTINUE TO MENTION IN HWO/EHWO GRAPHICS. PHASING BTWN THE NORTHERN STREAM WAVE AND SOUTHERN STREAM WAVES NEVEN REALLY TAKES OFF SO THIS SYSTEM SHOULD STAY PROGRESSIVE ON TUESDAY NIGHT AS MAIN CORE OF UPPER JET ENERGY STAYS OUT AHEAD OF THE TROUGH. CHANCE POPS LINGER EARLY TUESDAY EVENING IN THE EAST...BUT OTHERWISE POPS WITH THE SYSTEM WILL BE OUT OF THE AREA. INITIALLY LAKE EFFECT IN WAKE OF THE SYNOPTIC SNOW ON TUESDAY EVENING PROBABLY STAYS ON THE LIGHT SIDE DUE TO MARGINALLY COLD AIR /H85 TEMPS WARMER THAN -15C/ AND MAINLY ICE COVERED LAKE SUPERIOR. GFS SOUNDINGS SHOW INCREASE OF MOISTURE H8-H7 LATE TUESDAY NIGHT INTO WEDNESDAY WHILE COLD AIR ADVECTION WITH H85 TEMPS FALLING BLO -20C OVER LK SUPERIOR RESULTS IN INVERSIONS RISING UP TO A MAX OF 8KFT WEDNESDAY MORNING OVER EASTERN LK SUPERIOR. DESPITE THE HIGH ICE COVERAGE...SCT POPS FOR LAKE EFFECT SNOW SHOWERS AND ALSO FARTHER DOWNSTREAM OVER LAND AREAS WITH SOME HELP FM DAYTIME HEATING AS THE HYBRID LAKE EFFECT SEASON IS UNDERWAY DUE TO HIGHER SUN ANGLE. WITH NW WINDS UP TO 30 MPH ALONG THE LK SUPERIOR SHORELINES...PROBABLY WILL HAVE BLSN/POOR VSBY IN THE SNOW BELTS NEAR LK SUPERIOR EAST OF MQT. EVEN MINUS BLSN...LES WILL BE GOOD AT REDUCING VSBY AS THE SNOWFLAKES WILL BE BECOMING SMALLER. H85 TEMPS CONTINUE TO FALL BLO -25C BY LATE IN THE DAY ON WEDNESDAY...SO TEMPS WILL BE STEADY OR SLOWLY FALL THROUGH THE DAY. ARRIVAL OF HIGH PRESSURE RIDGE AND WINDS BACKING W-WSW BY THURSDAY MORNING WILL DIMINISH ANY SNOW SHOWERS AS WINDS BECOME MORE OFFSHORE. TEMPS OVER MUCH OF THE INTERIOR ON WEDNESDAY NIGHT COULD TANK WELL UNDER 10 BLO ZERO. MAY SEE MARGINALLY LOW WIND CHILLS ON THURSDAY MORNING...BUT FARTHER INLAND WHERE TEMPS WILL BE COLDEST EXPECT THE WINDS TO BE NEARLY CALM. STILL COLD ON THURSDAY AS CORE OF COLDER TEMPS ALOFT SLOWLY HEADS ACROSS EASTERN CANADA. WARM FRONT MOVES TOWARD UPPER LAKES THURSDAY NIGHT INTO FRIDAY MORNING. WARMING FIRST OCCURS ALOFT THEN MAKES ITS WAY TO SFC BY FRIDAY AFTN. GFS SOUNDINGS SHOW MID LEVEL MOISTURE QUICKLY SWEEPS ACROSS LEAVING SCT-BKN LOW CLOUDS LATER ON FRIDAY. MOISTURE AND LIFT DOES NOT SYNC UP...SO NOT EXPECING MUCH IN WAY OF LGT SNOW. BETTER LINKING OF LOW AND MID LEVEL MOISTURE IS OVER NORTHERN LK SUPERIOR AND NORTHERN ONTARIO. DECENT AGREEMENT IN THIS IDEA FM GFS AND ECMWF. COLD AIR NOT AS EMPHATIC FOR NEXT WEEKEND WITH GFS AND ECMWF SHOWING H85 TEMPS MAINLY WARMER THAN -12C. GIVEN THE RUN-TO-RUN DIFFERENCES IN MODELS AND DIFFERENCES IN MODEL SOLUTIONS...WILL JUST RUN WITH CONSENSUS FRIDAY THROUGH SUNDAY. RESULT IS DAYTIME TEMPS IN THE 20S TO NEAR 30 DEGREES AND ONLY SMALL CHANCES OF LGT SNOW MAINLY OVER THE NORTH AND EAST CWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1245 PM EST SUN MAR 1 2015 SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW FLOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 310 PM EST SUN MAR 1 2015 SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY. STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR. OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS. LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...ROLFSON MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1245 PM EST SUN MAR 1 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM EST SUN MAR 1 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS. MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN. MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE DISTURBANCES. TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE 25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL. TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85 THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN THAT AREA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 416 AM EST SUN MAR 1 2015 MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY. MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION. ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE WARMER THAN THE LAST SEVERAL WEEKS. MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND 0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND 2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA. WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE. KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P. FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30 FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS. THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT SNOW TO THE AREA ONCE AGAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1245 PM EST SUN MAR 1 2015 SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW FLOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 AM EST SUN MAR 1 2015 NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1156 AM EST SUN MAR 1 2015 .AVIATION... THE WIDESPREAD LIGHT SNOW WILL REMAIN SOUTH OF PTK THROUGH THE DURATION OF THE AFTERNOON. SOME ENHANCED SUBSIDENCE AND DAYTIME MIXING HAS ACTUALLY CLEARED THE LOW CLOUDS FROM PTK NORTHWARD. THERE ARE HOWEVER A FEW AREAS OF MVFR STRATO CU NEAR LAKE MI AND ACROSS PORTIONS OF WISCONSIN. A SFC TROUGH AXIS NOW OVER WISCONSIN WILL BE DRIVEN ACROSS SE MI OVERNIGHT IN RESPONSE TO THE PASSAGE OF AN UPPER LEVEL SHORT WAVE. THIS SHOULD ALLOW THESE LOWER CLOUDS UPSTREAM TO FILTER BACK INTO SE MI THIS EVENING. SOME LOW LEVEL COLD AIR ADVECTION TONIGHT ALONG THE SFC TROUGH WILL STEEPEN LOW LEVEL LAPSE RATES AND WILL SUPPORT SOME GUSTINESS /AROUND 20 KNOTS/ WITH THE WESTERLY WINDS OVERNIGHT. FOR DTW...THE NORTHERN EDGE TO THE LIGHT SNOW HAS LIFTED BACK ACROSS METRO LATE THIS MORNING. TRENDS IN RADAR...SFC OBS AND LATEST MODEL DATA SUGGEST THE SNOW WILL PERSIST THROUGH ROUGHLY 22Z BEFORE ENDING. AFTERNOON ACCUMULATIONS OF A HALF INCH TO AN INCH OF DRY POWDERY SNOW SEEM POSSIBLE. //DTW THRESHOLD PROBABILITIES... * HIGH IN CEILINGS BELOW 5000 FT THIS AFTERNOON AND TONIGHT. && .PREV DISCUSSION...ISSUED 907 AM EST SUN MAR 1 2015 UPDATE... THE NORTHERN EDGE OF THE FRONTOGENETICALLY FORCED LIGHT SNOW NOW EXTENDS FROM NORTH-CENTRAL ILLINOIS INTO SRN MONROE COUNTY. THE LATEST RAP AND NAM12 SUGGEST A SLIGHT NORTHWARD SHIFT AND REINTENSIFICATION OF THE MID LEVEL FGEN BETWEEN 18Z AND 21Z. THIS SUPPORTS THE CURRENT FORECAST WHICH HOLDS FAIRLY HIGH POPS UP THROUGH THE ANN ARBOR TO DETROIT CORRIDOR AND POINTS SOUTH. THE EXPECTED BREVITY OF THE STRONGER FORCING REMAINS SUPPORTIVE OF ADDITIONAL SNOWFALL ACCUMS OF AN INCH OR LESS. SOUTHWEST FLOW OFF THE REMAINING OPEN WATERS OF LAKE MI HAS BEEN ENOUGH TO GENERATE SOME LIGHT SNOW ACROSS WEST CENTRAL LOWER MI THIS MORNING. A VEERING OF THE LOW FLOW TOWARD THE WEST HAS BROUGHT SOME OF THIS LOW LEVEL MOISTURE INTO THE TRI CITIES REGION. CONDITIONS APPEAR TO BE SUPERSATURATED WITH RESPECT TO ICE WITHIN THESE CLOUDS WHICH IS LIKELY CAUSING SOME DECENT SNOWFLAKE SIZE /ALSO SUGGESTED BY SOME OF THE VSBY REDUCTIONS/. THE LATEST RADAR TRENDS SHOW A WEAKENING OF RETURNS. DIURNAL MIXING INTO SOME DRIER AIR MAY ALSO ERODE SOME OF THIS LOW LEVEL MOISTURE. IN LIGHT OF CURRENT OBS...AN UPDATE WILL HAVE TO BE ISSUED TO AT LEAST CARRY SOME FLURRIES ACROSS THE SAGINAW VALLEY TODAY. PREV DISCUSSION...ISSUED 357 AM EST SUN MAR 1 2015 SHORT TERM...TODAY AND TONIGHT SYNOPTIC SCALE ASCENT ANCHORED UNDER THE LEFT EXIT QUADRANT OF A POWERFUL ZONAL JET AXIS AND WEAK SYSTEM RELATIVE ISENTROPIC ASCENT ARE THE MECHANISMS RESPONSIBLE FOR THE BROAD FOOTPRINT OF LIGHT SNOW ACROSS THE REGION. THE LEAD EDGE OF THE PRECIPITATION WAS ABLE TO LIFT NORTHWARD THROUGH THE DETROIT METRO AREA PRIOR TO 6Z...TIMING WELL WITH A COMPACT 850MB TEMPERATURE GRADIENT. NWP DATA SUPPORTS THIS STEEPENED FRONTAL STRUCTURE TO CONTINUE TO LIFT NORTHEASTWARD AWAY FROM THE CWA...MAKING IT AS FAR NORTHWARD AS CENTRAL LAKE HURON AND SOUTHERN GEORGIAN BAY BY 12Z. AN ADDITIONAL STEEPEND FRONTAL STRUCTURE RESIDES TO THE SOUTH OF THE STATE...NOW OVER CENTRAL SECTIONS OF INDIANA AND OHIO. THIS FEATURE IS RESPONSIBLE FOR THE HIGHER Z RETURNS AND LOWER VSBYS IN SURFACE OBSERVATIONS. MODELS SUPPORT THIS BAROCLINIC ZONE TO REMAIN SOUTH OF THE AREA THROUGH THE DURATION OF THE EVENT. WITH THIS IN MIND...EXPECTATIONS ARE FOR A STATUS QUO TO SNOWFALL RATES THROUGH 12Z WITH VERY LIGHT SNOW ACCUMULATIONS THIS MORNING. WITH THE UPPER LEVEL JET FORCING AND LEAD MOISTURE ADVECTION VACATING THE PREMISES...FORCING WILL THEN DISTILL DOWN TO WEAK ISENTROPIC ASCENT. WHILE PERSISTENT...THERE IS SERIOUS QUESTION ON WHETHER OR NOT THIS UPGLIDE WILL BE SUFFICENT IN CONTINUING TO GENERATE MEASURABLE PRECIPATION. CURRENT RADAR MOSAIC DOES SHOW A DEFINITIVE BACK EDGE OF THE PRECIPATION SHIELD...WITH DRY AIR ALREADY ADVANCING THROUGH CHICAGOLAND AND INTO FAR SOUTHWESTERN LOWER MICHIGAN. VARIOUS SOLUTIONS THEN SUGGEST IT WILL REQUIRE THE AGEOSTROPHIC RESPONSE TO A POSITIVE D(MAG)/DT INCREASE OF THE UPPER LEVEL JET MAX TO ALLOW PRECIPATION TO FILL BACK IN ACROSS FAR SOUTHERN SECTIONS OF THE CWA FOR THE AFTERNOON. THIS IS EXPECTED TO OCCUR BETWEEN 19-00Z. GIVEN THE TRENDS IN NUMERICAL OUTPUT IN ADDITION TO THE RADAR DATA...WAS FAIRLY AGGRESSIVE IN LOWERING POPS AND AMOUNTS FOR AREAS NORTH OF DETROIT. IN SUM TOTAL...SNOWFALL ACCUMULATIONS OF 1 TO 2 INCHES WILL BE POSSIBLE FROM DETROIT SOUTHWARD WITH AN INCH POSSIBLE BETWEEN THE M 59 AND I 94 CORRIDORS. THE MAIN MIDLEVEL TROUGH AXIS AND NORTHERN STREAM WAVE WILL CATCH UP TO LOWER MICHIGAN TONIGHT PASSING THROUGH THE CWA AFTER 6Z. SHALLOW...LOWER TROPOSPHERIC COLD AIR ADVECTION IS FORECASTED TO STEEPEN LAPSE RATES IN THE 1.5 TO 5.5 KFT AGL LAYER. THE UNSTABLE PROFILE IN COMBINATION WITH PROGGED SATURATION WRT ICE AND CYCLONIC VORTICITY ADVECTION SUPPORTS HYDROMETEOR PRODUCTION THE LATTER HALF OF THE NIGHT. TOTAL LACK OF QPF SUPPORTS NOTHING MORE THAN A MENTION OF FLURRIES AT THIS TIME. LONG TERM... MODEL TRENDS EXPLORED DURING THE 12Z CYCLE LARGELY HOLD TRUE FOR THE 00Z RUNS WITH A BIT LESS DISPARITY IN SOLUTIONS. ESSENTIALLY...THE BROAD AND SOMEWHAT FLAT SOUTHERN EDGE OF THE EXISTING NOAM UPPER TROUGH WILL REMAIN IN PLACE OVER THE CONUS AS A POTENT NORTHERN STREAM SHORTWAVE NOW EXITING ALASKA TAKES A TRACK SOUTHEASTWARD THROUGH THE PRAIRIE PROVINCES AND THEN EAST ALONG THE SOUTHERN EDGE OF HUDSON BAY DURING THE FIRST PART OF THIS WEEK. THIS WILL STEER SOUTHERN STREAM ENERGY INTO THE AREA ON A RATHER FLAT TRAJECTORY. IN THE MEANTIME...WHILE THE ARCTIC AIRMASS IN PLACE TO OUR NORTH AS ERODED TO SOME EXTENT DURING THE PAST DAY OR TWO...IT STILL REMAINS EXPANSIVE ENOUGH TO MAINTAIN A TIGHT TEMPERATURE GRADIENT ACROSS THE GREAT LAKES. BETWEEN THESE TWO FACTORS...CHANCES ARE THAT COLD AIR WILL BE DIFFICULT TO DISPLACE OVER THE AREA. THIS SHOULD LEAD TO A FAIR AMOUNT OF THE PRECIPITATION FROM THIS SYSTEM FALLING AS SNOW. EVEN NAM12/GFS NOW SUPPORT A BASICALLY ALL SNOW EVENT FOR THE FAR NORTHERN CWA. THE MAIN QUESTION WILL BE THE TIMING AND PLACEMENT OF A CHANGEOVER TO SLEET/FREEZING RAIN AND THEN RAIN IN SOME LOCATIONS BY AFTERNOON AS THE SURFACE LOW REFLECTION OF THIS SYSTEM CROSSES THE AREA. WILL ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST AS MODELS DO NOT SUPPORT A STRONG SHIFT EITHER NORTH OF SOUTH IN THE PRECIPITATION TYPE FORECAST. GENERALLY...AREAS FROM I-69 NORTH ARE EXPECTED TO REMAIN LARGELY SNOW OR SLEET THROUGHOUT THE EVENT. FOR THE REST OF THE FORECAST AREA...PRECIPITATION WILL START AS SNOW TUESDAY MORNING WITH A GRADUAL CHANGEOVER TO SLEET/FREEZING RAIN FROM SOUTH TO NORTH AS SOME MILDER AIR WORKS INTO LOWER MICHIGAN AND THEN A CHANGE TO RAIN THROUGH THE SOUTHERN THIRD TO HALF OF THE AREA AS SURFACE AND BOUNDARY LAYER TEMPERATURES CLIMB INTO THE MID/UPPER 30S. OVERALL PRECIPITATION INTENSITY FORECASTS FROM THE MODELS SUGGEST ONLY LIGHT TO MODERATE PERIODS OVER A 8-10 HOUR PERIOD DURING THE DAY TUESDAY SO WHILE IT WILL MOST LIKELY BECOME RATHER MESSY IN TERMS OF TRAVEL THIS IS NOT A PARTICULARLY POWERFUL WINTER STORM. AS FOR TEMPERATURES...RELATIVELY MILD READINGS AS COMPARED TO THE PAST FEW WEEKS CAN BE EXPECTED MONDAY INTO TUESDAY. STILL WITH AVERAGE HIGHS IN THE UPPER 30S/LOWER 40S FOR EARLY MARCH THE AREA WILL REMAIN AOB AVERAGE EVEN DURING THIS PERIOD. MUCH COLDER AIR WILL THEN DUMP INTO THE AREA BEHIND THIS SYSTEM DURING THE LAST PART OF THE WEEK AS ANOTHER ARCTIC HIGH PRESSURE SYSTEM BUILDS SOUTHEAST THROUGH THE EASTERN CONUS WITHIN AMPLIFYING UPPER TROUGHING PATTERN THAT DEVELOPS AS ADDITIONAL NORTHERN STREAM SHORTWAVE ENERGY DIGS INTO AREA BEHIND THE EXITING STORM SYSTEM. AS THIS TROUGH PROGRESSES EASTWARD BY THE END OF THE FORECAST PERIOD...A MODERATION IS EXPECTED INTO NEXT WEEKEND WITH TEMPERATURES AT LEAST CLIMBING BACK INTO THE 30S. MARINE... A WEAK TO MODERATE SURFACE PRESSURE GRADIENT WILL MAINTAIN WINDS BELOW 20 KNOTS THROUGH SUNDAY NIGHT. A COLD FRONT WILL GRAZE THE NORTHERN PORTIONS OF LAKE HURON MONDAY AND BRING A FRESH NORTHWEST BREEZE WITH GUSTS TO 30 KNOTS POSSIBLE AS COLD AND MARGINALLY UNSTABLE CONDITIONS DEVELOP. HIGH PRESSURE WILL THEN BUILD INTO THE AREA FROM THE WEST WITH NEARLY CALM CONDITIONS TAKING HOLD MONDAY NIGHT BEFORE MODERATE SOUTHERLY WINDS EXPAND INTO THE REGION IN ADVANCE OF THE NEXT STORM SYSTEM DUE INTO THE AREA BY TUESDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....SC UPDATE.......SC SHORT TERM...CB LONG TERM....DG MARINE.......DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1140 AM EST SUN MAR 1 2015 LATEST UPDATE... HYDRO .SYNOPSIS... ISSUED AT 328 AM EST SUN MAR 1 2015 LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL WARM INTO THE MID 30S BY NEXT WEEKEND. && .UPDATE... ISSUED AT 934 AM EST SUN MAR 1 2015 I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING. THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE REST OF THE FORECAST REMAINS UNCHANGED. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 328 AM EST SUN MAR 1 2015 FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED. REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL BE A HALF INCH OR LESS. THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46 ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96. THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO DRIZZLE/FREEZING DRIZZLE. OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96 NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES. WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 328 AM EST SUN MAR 1 2015 ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING. YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE. SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE POSSIBLE ACROSS THE ENTIRE AREA. ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY) ISSUED AT 1125 AM EST SUN MAR 1 2015 FAIRLY EXTENSIVE LOW CLOUD COVER WILL RESULT IN PRIMARILY MVFR CONDITIONS THIS AFTERNOON. SOME LIGHT SNOW SHOWERS WILL LINGER AT KMKG INTO THE AFTERNOON BEFORE GRADUALLY DISSIPATING. CONDITIONS WILL GRADUALLY IMPROVE TO VFR AT ALL THE TERMINALS TONIGHT AS WINDS SHIFT TO THE WEST/NORTHWEST BEHIND A WEAK SFC TROUGH. DRIER AIR WILL MOVE IN OVERNIGHT AND ALLOW CIGS TO IMPROVE TO VFR. THE VFR CONDITIONS WILL THEN CONTINUE THROUGH 18Z MONDAY WITH WNW WINDS AOB 10 KTS. && .HYDROLOGY... ISSUED AT 1140 AM EST SUN MAR 1 2015 THE FORECAST GETS A LITTLE TRICKY IN THE UPCOMING WEEK WITH THE APPROACHING SYSTEM GOING INTO TUESDAY. TEMPERATURES COULD VARY QUITE A BIT RIGHT ALONG WITH EXPECTED PRECIPITATION TOTALS AND PRECIPITATION TYPE. THE CURRENT GUIDANCE SUGGESTS WE COULD GET A BIT FURTHER INTO MILDER AIR (NEAR NORMAL) AND ADD MORE LIQUID PRECIPITATION AS OPPOSED TO SNOW. OVERALL....IT IS NOT A DRASTIC WARM UP AND AMOUNTS MAY REMAIN AROUND OR BELOW HALF AN INCH. THIS COULD MOSTLY BE SOAKED UP BY CURRENT SNOW PACK. WITH LOW RIVER LEVELS AND GIVEN SITUATION...THIS SHOULD NOT RAISE ANY IMMEDIATE CONCERN BUT WILL BE ADDED LIQUID TO BE CONSIDERED IN FORECASTS DOWN THE ROAD. THE GOOD NEWS IS THAT THE SYSTEM LAST NIGHT INTO TODAY WAS QUITE LACKLUSTER IN REGARDS TO TOTALS. THEREFORE...WHAT WE MISSED LAST NIGHT WILL JUST SUBTRACT FROM THE OVERALL WEEKLY AMOUNTS WE WERE LOOKING AT YESTERDAY. THOUGH IT WAS NOT ANYTHING TOO HEAVY TO BEGIN WITH IT JUST RAISES CONFIDENCE THAT ANY UPWARD TRENDS IN TEMPERATURES WILL NOT HAVE AS MUCH OF A NEGATIVE IMPACT. CONDITIONS ARE EXPECTED TO REMAIN STABLE FOR NOW AND IN THE NEAR TERM. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...WDM SYNOPSIS...04 SHORT TERM...04 LONG TERM...MEADE AVIATION...LAURENS HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1125 AM EST SUN MAR 1 2015 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 328 AM EST SUN MAR 1 2015 LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL WARM INTO THE MID 30S BY NEXT WEEKEND. && .UPDATE... ISSUED AT 934 AM EST SUN MAR 1 2015 I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING. THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE REST OF THE FORECAST REMAINS UNCHANGED. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 328 AM EST SUN MAR 1 2015 FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED. REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL BE A HALF INCH OR LESS. THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46 ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96. THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO DRIZZLE/FREEZING DRIZZLE. OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96 NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES. WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 328 AM EST SUN MAR 1 2015 ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING. YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE. SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE POSSIBLE ACROSS THE ENTIRE AREA. ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY) ISSUED AT 1125 AM EST SUN MAR 1 2015 FAIRLY EXTENSIVE LOW CLOUD COVER WILL RESULT IN PRIMARILY MVFR CONDITIONS THIS AFTERNOON. SOME LIGHT SNOW SHOWERS WILL LINGER AT KMKG INTO THE AFTERNOON BEFORE GRADUALLY DISSIPATING. CONDITIONS WILL GRADUALLY IMPROVE TO VFR AT ALL THE TERMINALS TONIGHT AS WINDS SHIFT TO THE WEST/NORTHWEST BEHIND A WEAK SFC TROUGH. DRIER AIR WILL MOVE IN OVERNIGHT AND ALLOW CIGS TO IMPROVE TO VFR. THE VFR CONDITIONS WILL THEN CONTINUE THROUGH 18Z MONDAY WITH WNW WINDS AOB 10 KTS. && .HYDROLOGY... ISSUED AT 1132 AM EST SAT FEB 28 2015 CONDITIONS ON AREA RIVERS AND STREAMS REMAIN STABLE. THIS IS EXPECTED TO CONTINUE TO BE THE CASE THROUGH AT LEAST THE NEXT COUPLE OF DAYS. THE PATTERN WILL BECOME MORE ACTIVE AS WE GET INTO THE SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK. THE EXTREME COLD THAT HAS BEEN ALL TOO STUBBORN WILL BEGIN TO RELEASE ITS GRIP ON THE REGION. AS A RESULT...GRADUALLY WARMER TEMPERATURES WILL MAKE THEIR WAY IN THROUGH TUESDAY. WHILE THERE IS SOME QUESTION TO THE EXTENT OF THE WARMTH IT IS STILL NOT ANTICIPATED TO CREATE MANY ISSUES AS COLD AIR QUICKLY MOVES BACK IN DURING THE MIDDLE OF THE WEEK. TOTAL PRECIPITATION AMOUNTS SHOULD HOVER AROUND A HALF INCH THROUGH THE NEXT SEVEN DAYS WITH MOST OF THIS COMING IN THE TUESDAY SYSTEM. RIVERS WILL BE MONITORED THROUGH THE NEXT SEVERAL DAYS IN THAT CASE THAT ANY VARIABILITY IS SENSED. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...WDM SYNOPSIS...04 SHORT TERM...04 LONG TERM...MEADE AVIATION...LAURENS HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1129 AM CST SUN MAR 1 2015 .SYNOPSIS... ISSUED AT 347 AM CST SUN MAR 1 2015 AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES UNLIKELY. TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS. WINDS WERE LIGHT AND VARIABLE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CST SUN MAR 1 2015 FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32 AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO 10 MPH SOUTH. FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3 WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA. WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 347 AM CST SUN MAR 1 2015 12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY. THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE 285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1 TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF 5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE 0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS. BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF THE WORK WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1129 AM CST SUN MAR 1 2015 VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THROUGH TONIGHT. MID LEVEL CLOUDS WILL BEGIN TO MOVE INTO THE AREA FROM THE SOUTH MONDAY MORNING. LIGHT SNOW IS POSSIBLE AT KLBF AFTER 02/10Z...WHICH MAY TEMPORARILY CREATE MVFR CEILINGS AND/OR VISBY. WIND WILL LIKELY BE THE HIGHER CONCERN FOR KLBF AND KVTN AS GUSTS ABOVE 20 KNOTS ARE EXPECTED BY LATE MORNING MONDAY. && .HYDROLOGY... ISSUED AT 347 AM CST SUN MAR 1 2015 THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROBERG SHORT TERM...ROBERG LONG TERM...JACOBS AVIATION...DS HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
653 PM EST SUN MAR 1 2015 .SYNOPSIS... A WEDGE OF HIGH PRESSURE WILL COMPLETELY BREAK DOWN THROUGH MONDAY MORNING. A COLD FRONT WILL MOVE THROUGH MONDAY AFTERNOON FOLLOWED BY ANOTHER WEDGE OF COOL HIGH PRESSURE FOR TUESDAY. TEMPERATURES ARE EXPECTED TO BE WELL ABOVE NORMAL ON WEDNESDAY AHEAD OF A STRONG COLD FRONT THAT WILL MOVE ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW PRESSURE MAY DEVELOP ALONG THE FRONT...KEEPING THE WEATHER UNSETTLED THROUGH THURSDAY. CHILLY HIGH PRESSURE WILL BUILD ACROSS THE AREA FRIDAY AND PERSIST THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AS OF 200 PM SUNDAY...ISENTROPIC LIFT OVER THE AREA THIS AFTERNOON WILL GRADUALLY WEAKEN AS HIGH WEDGING DOWN THE COAST IS SHIFTED EAST BY WESTERLY FLOW ALOFT. ALTHOUGH THE WEDGE WILL BE IN THE PROCESS OF BREAKING DOWN OVERNIGHT...LIGHT WESTERLY FLOW BECOMES PREVALENT BY DAYBREAK...LOW LEVEL CLOUDS AND MOISTURE WILL LINGER THROUGH THE END OF THE PERIOD. FORECAST SOUNDINGS CONTINUE TO SHOW THE COLUMN UNDER 1500 FT ALMOST FULLY SATURATED. WHILE THERE IS NO REAL SOURCE OF LIFT...AND EVEN SOME WEAK SUBSIDENCE ...THE PRESENCE OF ABUNDANT LOW LEVEL MOISTURE TRAPPED UNDER THE LOW LEVEL INVERSION WILL NOT ONLY RESULT IN STRATUS HANGING AROUND ALL NIGHT BUT COULD LEAD TO PATCHES OF MIST OR DRIZZLE. THE PREVIOUSLY MENTIONED LACK OF FORCING SHOULD PREVENT ANY MEASURABLE PRECIP SO BY MIDNIGHT HAVE MOST AREAS UNDER MENTIONABLE POP THRESHOLDS. FORECAST SOUNDINGS AND MODEL LAYER DATA KEEP BOUNDARY LAYER WINDS JUST HIGH ENOUGH TO PREVENT DEVELOPMENT OF WIDESPREAD FOG...THOUGH PATCHES OF 4-5SM ARE CERTAINLY POSSIBLE. TEMPERATURES WILL BE NEAR CLIMO OVERNIGHT WITH WESTERLY FLOW AND CLOUDS KEEPING LOWS IN THE UPPER 30S TO LOWER 40S. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...PROGRESSIVE REGIME THROUGH THE PERIOD. ONE WEDGE OF HIGH PRESSURE WILL COMPLETELY BREAK DOWN MON MORNING AHEAD OF THE NEXT COLD FRONT WHICH WILL MOVE ACROSS THE EASTERN CAROLINAS MON AFTERNOON. THERE COULD BE SOME VERY LIGHT PRECIPITATION AROUND ON MON...DIFFICULT TO SAY WHETHER ISOLATED SPOTS WILL RECEIVE MEASURABLE RAINFALL. WILL CONFINE POPS TO NEAR 20 PERCENT OR JUST BELOW ON MON. A VERY PRONOUNCED NEAR SURFACE INVERSION WILL KEEP LOW CLOUDS/FOG AROUND FOR THE FIRST PART OF THE MORNING. THIS STRONG INVERSION DOES FINALLY BREAK DOWN AND SO WE MAY AT LEAST SEE SOME GLIMPSES OF SUNSHINE DURING MON. ONCE THE COLD FRONT MOVES THROUGH...ANOTHER WEDGE OF HIGH PRESSURE WILL BUILD ACROSS THE CAROLINAS MON NIGHT INTO TUE AS HIGH PRESSURE MOVES OUT OF THE MID-WEST AND ACROSS THE MID-ATLANTIC STATES. THIS WILL LOCK IN LOW-LEVEL MOISTURE...WITH WIDESPREAD LOW CLOUDS EXPECTED TO REDEVELOP LATER MON NIGHT AND THEN PERSIST INTO TUE AS COLD AIR ADVECTION REDEVELOPS ON LOW-LEVEL NE FLOW. ISENTROPIC UPGLIDE IS EXPECTED TO DEVELOP MON NIGHT AS MOIST S TO SW OR WSW WINDS ABOVE 2 KFT TOP THE COOL DOME OF AIR NEAR THE SURFACE. ALSO...A COASTAL TROUGH IS EXPECTED TO DEVELOP LATE MON NIGHT AND TUE. THIS TROUGH WILL LIFT ATLANTIC MOISTURE OVER THE TOP OF THE LOW-LEVEL INVERSION AND NOT ONLY KEEP SKIES CLOUDY...BUT BRING MORE WET WEATHER. THERE IS NO RISK OF ANY FREEZING OR FROZEN PRECIPITATION. QPF AMOUNTS WILL BE LIGHT. THE HIGH DOES MOVE OFF THE COAST LATE TUE AND TUE NIGHT AND THE MODELS ARE IN A HURRY TO BREAK DOWN THE WEDGE. ALTHOUGH IT MAY EVOLVE SLOWER THAN CURRENTLY PORTRAYED...IT DOES LOOK LIKE THE NEXT COLD FRONT WILL BE STRONGER AND ITS PROXIMITY SHOULD ALLOW A WARMER RETURN FLOW TO DEVELOP OVERNIGHT AT ALL LEVELS. WILL SHOW TEMPS TRENDING HIGHER THROUGH THE NIGHT AS INCREASINGLY SOUTHERLY WINDS DEVELOP. TEMPS WILL BE BELOW NORMAL THROUGH THE PERIOD WITH MON LIKELY CONSIDERABLY WARMER THAN TUE. HIGHS MON WILL BE IN THE UPPER 50S AND LOWER 60S WITH SOME MID 60S POSSIBLE ALONG THE SOUTH SANTEE RIVER AREA. WE WILL HAVE TO SUBTRACT A GOOD 10 DEGREES FROM THOSE VALUES ON TUE. LOWS WILL BE MAINLY IN THE UPPER 30S AND LOWER 40S MON NIGHT. LOWS TUE EVE WILL BE VERY NEAR THE HIGHS OF THE DAY AND THEN MOVE UPWARDS FROM THERE DURING THE NIGHT. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 300 PM SUNDAY...VERY WARM START TO THE EXTENDED PERIOD WITH WEDNESDAY BEING THE WARMEST DAY IN QUITE A WHILE. UPPER RIDGE WILL HOLD ON UP THROUGH THE SOUTHEAST AS DEEP TROUGH DIGS DOWN THROUGH THE MID WEST. THIS WILL AID IN KEEPING A DRIER AND WARMER DAY OVER THE COASTAL CAROLINAS. ALTHOUGH OVERALL MOISTURE THROUGH THE COLUMN IS GENERALLY HIGH WITH UP TO 1.3 INCHES OF PCP WATER WED MORNING...THE SOUNDINGS AND MOISTURE PROFILES KEEP IT CONFINED TO VERY LOW LEVELS AND VERY HIGH WITH A DECENT DRY LAYER THROUGH THE MID LEVELS. THIS MAY ALLOW SOME BREAKS IN THE CLOUDS TO HELP PUSH TEMPS WELL INTO THE 70S. THE COAST WILL NOT BE AS FORTUNATE AS SOUTHERLY FLOW WILL BRING THE COOLER OCEAN AIR OVER THE BEACHES ADVECTING INLAND A BIT. ALSO THE POTENTIAL FOR SEA FOG WILL EXIST AS THE WARMER AIR RUSHES OVER THE COOLER WATERS. BY LATE WED SHWRS WILL INCREASE AS COLD FRONT DRAWS CLOSER. WILL KEEP LOW END POPS OVER PORTIONS OF AREA...MAINLY INLAND ON WED BUT EXPECT BEST CHC OF PCP TO COME WED EVE INTO THURS. A STRONG COLD FRONT WILL CROSS THE AREA WED NIGHT WITH PLENTY OF CAA TO FOLLOW. SEEMS LIKE MODELS ARE COMING BACK TO AN EARLIER FROPA FOR WED NIGHT INSTEAD OF THURS. MAY SEE MAX TEMPS FOR THURS AT MIDNIGHT WED NIGHT BEFORE DROPPING BEHIND FRONT...ESPECIALLY ALONG COASTAL LOCATIONS WHERE FRONT WILL PASS THROUGH AFTER MIDNIGHT. THE SHALLOW COOL AIR WILL COME RUSHING IN BUT MID TO UPPER TROUGH HANGS BACK TO THE WEST. THIS WILL LEAD TO SHORTWAVE ENERGY RIDING UP ALONG THE EAST SIDE OF THE TROUGH THROUGH THE SOUTHEAST PRODUCING WAVES OF LOW PRESSURE DEVELOPING ALONG FRONT WHICH SHOULD REMAINED ALIGNED SW TO NE JUST TO OUR SOUTH. THEREFORE CLOUDS AND PCP SHOULD LINGER THROUGH THURS AND POSSIBLY LONGER. ALTHOUGH COLD AIR WILL BE LOCKED IN AT THE SFC...WARMER AIR ALOFT SHOULD KEEP ALL PCP AS A COLD RAIN BEHIND FRONT AT THIS POINT. THE GFS DOES SHOW MAIN SHORTWAVE SWINGING OFF THE COAST BY FRI MORNING AS SFC HIGH BUILDS OVER THE CAROLINAS....BUT A BROAD TROUGH REMAINS OVER THE EAST WITH MORE OF A ZONAL FLOW ALOFT BUT THERE WILL BE POTENTIAL FOR OTHER SHORTWAVES TO MOVE THROUGH. FOR NOW WILL REMAIN MORE OPTIMISTIC FOR FRI INTO THE WEEKEND WITH A DRIER ALTHOUGH COOLER FORECAST. TEMPS WILL TAKE A DIVE ONCE COLD FRONT SHIFTS SOUTH WED NIGHT WITH 850 TEMPS UP AROUND 12C WED AFTN DROPPING DOWN JUST BELOW 0C BY FRI MORNING. THIS STRONG CAA AND POSSIBLY LINGERING CLOUDS AND PCP WILL KEEP VERY COOL TEMPS FOR THURS AND FRI. THE LATEST GUIDANCE SHOWS MAX TEMPS ONLY REACHING INTO THE 40S ON THURS AND NOT EVEN REACHING 40 ON FRI IN MANY PLACES. FOR NOW...WILL TREND COOLER BUT NOT GET THAT EXTREME JUST YET AS MODELS HAVE NOT REMAINED VERY CONSISTENT WITH THIS SYSTEM FOR LATE WEEK. HESITANT ESPECIALLY ON FRI AS SUNSHINE WILL MAKE ITS WAY OUT AND THIS TIME OF YEAR THE SUN IS PLAYING A BIGGER ROLE IN WARMING. && .AVIATION /00Z MONDAY THROUGH SATURDAY/... AS OF 00Z...RATHER LOW CONFIDENCE WITH THE NEXT SET OF TAFS AS FRONT PRETTY MUCH LAYS OVER TOP OF US THROUGH THE FORECAST PERIOD. CEILINGS WILL LIKELY BOUNCE FROM IFR TO MVFR BEFORE REMAINING PREDOMINATELY IFR OVERNIGHT. LIGHT PRECIP ALONG THE COAST WILL MOVE OUT OF THE REGION IN A FEW HOURS...AND THE HRRR MODEL SEEMS TO HAVE A REASONABLE HANDLE ON IT. A WEAK TROUGH OF LOW PRESSURE WILL GIVE US MAINLY WESTERLY WINDS OVERNIGHT...QUITE LIGHT. IFR CONDITIONS WILL CONTINUE THROUGH THE MORNING HOURS ON MONDAY BEFORE LIFTING TO MVFR OR BETTER. FRONT DROPS SOUTH OF THE REGION MONDAY AFTERNOON...WITH WINDS SHIFTING TO THE NORTHEAST. EXTENDED OUTLOOK...BECOMING VFR LATE MON. PERIODS OF MVFR/SHOWERS TUE/WED. RAIN/IFR THUR. VFR DEVELOPING FRI. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 200 PM SUNDAY...GRADIENT CONTINUES TO WEAKEN WITH THE WEAKENING COASTAL TROUGH NOW CLOSE TO THE COAST. WINDS AT 41013 HAVE GONE SOUTH-SOUTHEAST BUT REMAIN AROUND 10 KT. NORTHEAST 10 TO 15 KT OVER THE NEARSHORE WATERS WILL CONTINUE FOR THE REMAINDER OF THE AFTERNOON WITH WINDS BECOMING LIGHT AND VARIABLE OVERNIGHT. CLOSER TO DAYBREAK LIGHT OFFSHORE FLOW WILL DEVELOP AS WEAK HIGH CENTERED OVER GA/SC BECOMES MORE DOMINANT. GRADIENT REMAINS WEAK AND WESTERLY FLOW LATE IN THE PERIOD WILL CONTINUE TO RUN 10 KT OR LESS. SEAS 3 TO 5 FT THIS AFTERNOON AND EVENING WILL CONTINUE THE DOWNWARD TREND OVERNIGHT...FALLING TO 2 TO 4 FT BY THE END OF THE PERIOD. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...MARINERS SHOULD EXPECT CHANGEABLE WIND DIRECTIONS THIS PERIOD. WINDS MON MORNING WILL BE WESTERLY...BUT WITH THE PASSAGE OF A COLD FRONT WILL SHIFT TO N DURING THE AFTERNOON. NE WINDS WILL BE NEAR SMALL CRAFT ADVISORY LEVELS MON NIGHT AS A SURGE DEVELOPS IN RESPONSE TO A BUILDING WEDGE OF HIGH PRESSURE. THE WIND DIRECTION WILL VEER TO EASTERLY DURING TUE AND THEN SE AND S BY TUE EVE AS HIGH PRESSURE TO OUR NORTH MOVES FURTHER OFFSHORE. WINDS OVERNIGHT TUE WILL VEER TO SW AHEAD OF A STRONG COLD FRONT. THE STRONGEST WINDS ARE EXPECTED MON NIGHT...UP TO 20 TO 25 KT. SEAS WILL BE HIGHEST MON NIGHT INTO TUE...UP TO 4 TO 7 FT. SEAS MAY APPROACH 6 FT TUE NIGHT...MAINLY ACROSS THE NORTHERN OFFSHORE WATERS. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 PM SUNDAY...SOUTHERLY WINDS WILL CONTINUE THROUGH WED UP TO 15 TO 20 KTS KEEPING SEAS GENERALLY IN THE 4 TO 6 FT RANGE BUT WILL INCREASE WED NIGHT INTO THURS AS COLD FRONT MOVES THROUGH. THE TIGHTENED GRADIENT FLOW WILL PRODUCE WINDS UP NEAR 20 KTS AS THEY SHIFT MORE ABRUPTLY AROUND FROM SW TO N BEHIND FRONT OVERNIGHT WED. STRONG CAA AND TIGHTENED GRADIENT WILL KEEP SEAS UP TO 4 TO 7 FT THURS. THE FRONT WILL LINGER TO THE SOUTH AS HIGH PRESSURE BUILDS DOWN INTO THE WATERS FROM THE NW. THIS MAY KEEP A PROLONGED PERIOD OF SCA CONDITIONS IN STRONG NORTHERLY WINDS THROUGH THURS INTO FRI. WINDS WILL LIGHTEN THROUGH LATE FRI AND BECOME MORE VARIABLE INTO THE WEEKEND AS HIGH PRESSURE SHIFTS CLOSER OVERHEAD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...III SHORT TERM...RJD LONG TERM...RGZ AVIATION...43
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
307 PM EST SUN MAR 1 2015 .SYNOPSIS... COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH MONDAY/... TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS OF EARLY AFTERNOON. THEREFORE THE ADVISORIES HAVE BEEN DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD FINALLY BE ERADICATED. THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH OR LESS. OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH PRESSURE BUILDS INTO THE AREA AT THE END. USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... A PROLONGED WET SYSTEM APPROACHES THE FORECAST AREA ON TUESDAY AND ULTIMATELY DECIDES TO TAKE ITS TIME MOVING THROUGH THE WILD AND WONDERFUL STATE. THE GFS IS THE MOST PROGRESSIVE OF THE BUNCH WHILE THE EURO AND NAM ARE SIMILAR KEEPING A FIRE HOSE POINTED AT US FOR AT LEAST 24 HOURS. THIS FORECAST MORE CLOSELY FOLLOWS THE WETTER/SLOWER MODELS. ITS WORTH MENTIONING THAT THERE IS SOME UNCERTAINTY IN THE LOCATION IN WHICH THE HEAVIEST RAIN FALLS...SO THE QPF IS LIKELY BLENDED OVER A LARGER PORTION OF THE AREA THAN WHAT WILL ACTUALLY HAPPEN. THE MOISTURE TAP FOR THIS SYSTEM EXTENDS ALL THE WAY BACK TO THE BAJA PENINSULA...SO REGARDLESS THIS WILL BE A RATHER JUICY SYSTEM WITH ATMOSPHERIC RIVER POTENTIAL. A 70+ KT SWLY LLJ DEVELOPS ENHANCING LOW LEVEL MOISTURE ADVECTION. ALL SAID AND DONE 2 INCHES OF QPF SOUNDS REASONABLE FOR MOST PLACES...THIS COUPLED WITH SNOWPACK MELTING IN THE WARMER TEMPERATURES THAT WE WILL EXPERIENCE WILL CAUSE A SCENARIO WHERE FLOODING IS A LARGE CONCERN. ALSO OF CONCERN IS THE STRONGER WINDS IN THE MOUNTAINS...DEPENDING ON HOW MUCH SNOW MELT OCCURS AND HOW THAWED AND SATURATED THE GROUNDS ARE THIS COULD BE ANOTHER POTENTIAL HAZARD. && .LONG TERM /THURSDAY THROUGH SUNDAY/... FRONTAL BOUNDARY WILL BE EAST OF THE AREA THURSDAY MORNING...WITH COLDER AIR FILTERING INTO THE REGION...AND ANY LINGERING PRECIPITATION CHANGING OVER TO SNOW. EXPECTING LIGHT ACCUMULATIONS EARLY THURSDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES. HIGH PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING FRONT...FOR CONTINUED COOL...BUT DRY CONDITIONS. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6 TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT. CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE. MON WILL BRING IMPROVING CONDITIONS WITH MOUNTAIN SNOW SHOWERS ENDING BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW 3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW. LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT. MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL BECOME MODERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE IS THE CHANCE FOR THIS OCCURRING TONIGHT BEFORE THE COLD FRONT ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE TABLE BELOW. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02 CRW CONSISTENCY H H L L L L L L L L L L HTS CONSISTENCY M M L L L L L L L L L L BKW CONSISTENCY H H L L L L L L L L M M EKN CONSISTENCY M M L L L L L L L L L L PKB CONSISTENCY L L L L L L L L L L M H CKB CONSISTENCY L L L L L L L L L L L L AFTER 18Z MONDAY... IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS SNOW AT THE END WEDNESDAY NIGHT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/RPY/SL/30 NEAR TERM...TRM SHORT TERM...JW LONG TERM...SL AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
139 PM EST SUN MAR 1 2015 .SYNOPSIS... COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH MONDAY/... TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS OF EARLY AFTERNOON. THEREFORE THE ADVISORIES HAVE BEEN DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD FINALLY BE ERADICATED. THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH OR LESS. OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH PRESSURE BUILDS INTO THE AREA AT THE END. USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... ATTENTION TURNS TO WHAT HAS BECOME A WELL ADVERTISED WET SYSTEM SLATED FOR MID WEEK. LIKE HPC...STILL PREFER THE LESS PROGRESSIVE SCENARIO GIVEN POSITIVE TILT TO UPPER TROF HANGING BACK...OWING TO LESS PROGRESSION OF SFC FLOW AS THE FLOW ALOFT REMAINS PARALLEL TO SFC FRONT. PRECIP WILL BREAK OUT ALONG DEVELOPING WARM FRONT TUESDAY...WITH BEST CHANCES ACROSS SE OH. THERE MAY BE A VERY BRIEF MIX AT THE ONSET...BUT THIS IS PRIMARILY A RAIN MAKER ON TUESDAY. TRIED TO KEEP HIGH POPS CONFINED TO SE OH AND N WV AS REMAINDER OF AREA REMAINS IN THE MORE SHOWERY WARM SECTOR. LLJ INCREASES TO NEAR 70 KTS TUESDAY NIGHT OUT OF SW WITH THE OVERALL FLOW TRYING TO BECOME PARALLEL TO THE SFC COLD FRONT AS IT BEGINS TO SLOW DOWN CONSIDERABLY ON APPROACH. COPIOUS AMOUNTS OF MOISTURE WILL BE POOLED ALONG FRONTAL BOUNDARY...WITH PWATS SURGING TO NEAR 1.5 INCHES ON IMPRESSIVE THETA E ADVECTION. THE FIRST AREA OF CONCERN WILL BE ACROSS SE OH TUESDAY NIGHT...AND SLOW SHIFTING SE ON WEDNESDAY AS THE FRONT SAGS SE. IT IS AT THIS POINT MODELS DIVERGE WITH GFS CONTINUING TO BE ON THE PROGRESSIVE SIDE. THE NEW ECMWF IS NOT AS PROGRESSIVE BUT DOES ENTRAIN MODIFIED ARCTIC AIR INTO THIS SYSTEM COME WEDNESDAY NIGHT. AGAIN...STILL PREFER THE LESS PROGRESSIVE SCENARIO ATTM...WHICH KEEPS THE RAIN GOING ALONG AND E OF THE OH RIVER ON WEDNESDAY. KEPT THE HEAVY RAIN WORDING IN WX GRIDS. QPF AMOUNTS LOOK TO AVG AROUND 2 INCHES AREAWIDE. WILL KEEP HWO WORDING AS IS. AS MENTIONED...THINGS GET TRICKY HEADING INTO WEDNESDAY NIGHT WITH THE LESS PROGRESSIVE ECMWF WITH SECONDARY SURFACE WAVE FORMING ALONG THE BOUNDARY AMID COLD AIR INTRUSION. THIS BRINGS A CONCERN THAT STARTS WITH HEAVY RAIN AND FLOODING TO THE OTHER END OF THE SPECTRUM WITH WINTRY WX. CONFIDENCE IS LOW REGARDING EXTENT OF ANY WINTRY WX ON THE BACK SIDE OF THIS AND THE MAGNITUDE OF SUCH ATTM. ON A SIDE NOTE...TEMPS WILL BE WARMING TO MORE SEASONAL LEVELS IN THE WARM SECTOR WITH LOW TO MID 50S LOOKING LIKE A GOOD BET ON BY TUESDAY AFTERNOON IN THE LOWLANDS AMID BREEZY S FLOW. THESE WARM TEMPS HANG ON TUESDAY NIGHT FOR A RATHER MILD NIGHT FOR THIS TIME OF YEAR. DEPENDING ON HOW THINGS PLAY OUT ON WEDNESDAY AND WEDNESDAY NIGHT WILL DETERMINE JUST HOW RAPID A FALL OF TEMPS TO EXPECT BEHIND THE FRONT. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... FRONTAL BOUNDARY WILL BE EAST OF THE AREA THURSDAY MORNING...WITH COLDER AIR FILTERING INTO THE REGION...AND ANY LINGERING PRECIPITATION CHANGING OVER TO SNOW. EXPECTING LIGHT ACCUMULATIONS EARLY THURSDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES. HIGH PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING FRONT...FOR CONTINUED COOL...BUT DRY CONDITIONS. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6 TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT. CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE. MON WILL BRING IMPROVING CONDITIONS WITH MOUNTAIN SNOW SHOWERS ENDING BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW 3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW. LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT. MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL BECOME MODERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE IS THE CHANCE FOR THIS OCCURRING TONIGHT BEFORE THE COLD FRONT ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE TABLE BELOW. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 CRW CONSISTENCY H H H H L L L L L L L L HTS CONSISTENCY H H M M L L L L L L L L BKW CONSISTENCY H H H M L L L L L L L L EKN CONSISTENCY H H H H L L L L L L L L PKB CONSISTENCY H H L L L L L L L L L L CKB CONSISTENCY H H L L L L L L L L L L AFTER 18Z MONDAY... IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS SNOW AT THE END WEDNESDAY NIGHT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/RPY/SL/30 NEAR TERM...TRM SHORT TERM...30 LONG TERM...SL AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
135 PM EST SUN MAR 1 2015 .SYNOPSIS... COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH MONDAY/... TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS OF EARLY AFETRNOON. THEREFORE THE ADVISORIES HAVE BEEN DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD FINALLY BE ERRADICATED. THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH OR LESS. OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH PRESSURE BUILDS INTO THE AREA AT THE END. USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... ATTENTION TURNS TO WHAT HAS BECOME A WELL ADVERTISED WET SYSTEM SLATED FOR MID WEEK. LIKE HPC...STILL PREFER THE LESS PROGRESSIVE SCENARIO GIVEN POSITIVE TILT TO UPPER TROF HANGING BACK...OWING TO LESS PROGRESSION OF SFC FLOW AS THE FLOW ALOFT REMAINS PARALLEL TO SFC FRONT. PRECIP WILL BREAK OUT ALONG DEVELOPING WARM FRONT TUESDAY...WITH BEST CHANCES ACROSS SE OH. THERE MAY BE A VERY BRIEF MIX AT THE ONSET...BUT THIS IS PRIMARILY A RAIN MAKER ON TUESDAY. TRIED TO KEEP HIGH POPS CONFINED TO SE OH AND N WV AS REMAINDER OF AREA REMAINS IN THE MORE SHOWERY WARM SECTOR. LLJ INCREASES TO NEAR 70 KTS TUESDAY NIGHT OUT OF SW WITH THE OVERALL FLOW TRYING TO BECOME PARALLEL TO THE SFC COLD FRONT AS IT BEGINS TO SLOW DOWN CONSIDERABLY ON APPROACH. COPIOUS AMOUNTS OF MOISTURE WILL BE POOLED ALONG FRONTAL BOUNDARY...WITH PWATS SURGING TO NEAR 1.5 INCHES ON IMPRESSIVE THETA E ADVECTION. THE FIRST AREA OF CONCERN WILL BE ACROSS SE OH TUESDAY NIGHT...AND SLOW SHIFTING SE ON WEDNESDAY AS THE FRONT SAGS SE. IT IS AT THIS POINT MODELS DIVERGE WITH GFS CONTINUING TO BE ON THE PROGRESSIVE SIDE. THE NEW ECMWF IS NOT AS PROGRESSIVE BUT DOES ENTRAIN MODIFIED ARCTIC AIR INTO THIS SYSTEM COME WEDNESDAY NIGHT. AGAIN...STILL PREFER THE LESS PROGRESSIVE SCENARIO ATTM...WHICH KEEPS THE RAIN GOING ALONG AND E OF THE OH RIVER ON WEDNESDAY. KEPT THE HEAVY RAIN WORDING IN WX GRIDS. QPF AMOUNTS LOOK TO AVG AROUND 2 INCHES AREAWIDE. WILL KEEP HWO WORDING AS IS. AS MENTIONED...THINGS GET TRICKY HEADING INTO WEDNESDAY NIGHT WITH THE LESS PROGRESSIVE ECMWF WITH SECONDARY SURFACE WAVE FORMING ALONG THE BOUNDARY AMID COLD AIR INTRUSION. THIS BRINGS A CONCERN THAT STARTS WITH HEAVY RAIN AND FLOODING TO THE OTHER END OF THE SPECTRUM WITH WINTRY WX. CONFIDENCE IS LOW REGARDING EXTENT OF ANY WINTRY WX ON THE BACK SIDE OF THIS AND THE MAGNITUDE OF SUCH ATTM. ON A SIDE NOTE...TEMPS WILL BE WARMING TO MORE SEASONAL LEVELS IN THE WARM SECTOR WITH LOW TO MID 50S LOOKING LIKE A GOOD BET ON BY TUESDAY AFTERNOON IN THE LOWLANDS AMID BREEZY S FLOW. THESE WARM TEMPS HANG ON TUESDAY NIGHT FOR A RATHER MILD NIGHT FOR THIS TIME OF YEAR. DEPENDING ON HOW THINGS PLAY OUT ON WEDNESDAY AND WEDNESDAY NIGHT WILL DETERMINE JUST HOW RAPID A FALL OF TEMPS TO EXPECT BEHIND THE FRONT. && .LONG TERM /THURSDAY THROUGH SUNDAY/... LONG TERM STARTS OUT RATHER SOAKING WET. COLD FRONT WILL SLOWLY BE PROGRESSING EASTWARD ACROSS THE CWA AT THE BEGINNING OF THE PERIOD...WITH A WAVE OF LOW PRESSURE RIDING ALONG THE FRONT FROM SOUTHWEST TO NORTHEAST...ENHANCING PRECIPITATION AS IT DOES SO. STILL LOOKING LIKE HEAVY RAIN ON WEDNESDAY...IN THE MOIST ATMOSPHERE...ALONG WITH SOME RATHER GUSTY WINDS EXPECTED TUESDAY NIGHT INTO EARLY WEDNESDAY...WITH THE STRONG SOUTHWESTERLY FLOW AND TIGHT PRESSURE GRADIENT. RAISED WIND GUSTS AND ADDED HEAVY RAIN WORDING IN THE TUESDAY NIGHT THROUGH WEDNESDAY PERIOD. FRONT WILL BEGIN TO PUSH EAST THURSDAY OR THURSDAY NIGHT...WITH COLDER AIR RUSHING IN...AND A CHANGE OVER TO SNOW AREA WIDE. ITS POSSIBLE THERE COULD BE SOME LIGHT ACCUMULATIONS...BUT WITH THE WET...WARM GROUND...AT THIS POINT NOT SURE HOW MUCH WILL ACTUALLY BE ABLE TO ACCUMULATE. COLD HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING FRONT FOR FRIDAY INTO THE REMAINDER OF THE EXTENDED. WITH TEMPERATURES DIPPING BELOW NORMAL ONCE AGAIN. WILL CONTINUE TO HIGHLIGHT WATER ISSUES FOR NEXT WEEK IN THE HWO. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6 TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT. CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE. MON WILL BRING IMPROVING CONDITONS WITH MOUNTAIN SNOW SHOWERS ENDING BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW 3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW. LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT. MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL BECOME MOERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE IS THE CHANCE FOR THIS OCCURING TONIGHT BEFORE THE COLD FRONT ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE TABLE BELOW. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 CRW CONSISTENCY H H H H L L L L L L L L HTS CONSISTENCY H H M M L L L L L L L L BKW CONSISTENCY H H H M L L L L L L L L EKN CONSISTENCY H H H H L L L L L L L L PKB CONSISTENCY H H L L L L L L L L L L CKB CONSISTENCY H H L L L L L L L L L L AFTER 18Z MONDAY... IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS SNOW AT THE END WEDNESDAY NIGHT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/RPY/SL/30 NEAR TERM...TRM SHORT TERM...30 LONG TERM...SL AVIATION...TRM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
346 PM EST SUN MAR 1 2015 .SYNOPSIS... WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS PENNSYLVANIA THIS EVENING. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY INTO THIS EVENING. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY WEDNESDAY...BRINGING MAINLY RAIN TO THE AREA. COLDER TEMPERATURES WILL FOLLOW FOR THE LATER PART OF THE WEEK. && .NEAR TERM /UNTIL 11 PM THIS EVENING/... DID ADJUST THE AREA OF FREEZING RAIN SOME...TO FIT IN WITH THE CURRENT OBS. EARLIER DISCUSSION BELOW. BRIGHT BANDING AND ELEVATED CCS SHOWING THE PRECIP TRANSITION ZONE WELL AS IT TRANSLATES NORTH OF THE MD BORDER INTO THE SOUTH CENTRAL MOUNTAINS AND FAR LOWER SUSQ RIVER VALLEY. 3" OF NEW SNOW O.G. NEAR GREENCASTLE FROM A TRUSTED WEATHER SPOTTER AND NOW FREEZING RAIN OCCURRING AT 27F. SLEET HAD BRIEFLY MIXED IN EARLIER ACROSS SOUTHERN YORK. A GENERAL 2-4" IS EXPECTED SOUTH OF INTERSTATE 80 AND EAST OF ROUTE 99...WITH THE ADDITIONAL CHANGEOVER TO ICE ACROSS SOUTHERN PORTIONS OF THE SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ RIVER VALLEY ADDING ANOTHER .1 TO .15" OF ICE ON TOP IN THOSE AREAS. OVERALL SCENARIO PLAYING OUT WITH WITH PERIODS OF SNOW (OF VARYING INTENSITY) CONTINUING TO INCREASE IN AREAL COVERAGE THIS AFTERNOON FROM SOUTHWEST TO NORTHEAST. STRONG VERTICAL SHEAR EVIDENT ACROSS THE REGION WITH 150+ KT 250 MB JET SLICING ENE ACROSS THE NORTHERN OHIO VALLEY AND EASTERN GLAKS. BOUNDARY LAYER CONVERGENCE AND FORCING IS BEST ACROSS SOUTHERN PA THIS AFTERNOON AND EVENING...IN VICINITY OF 850 MB JET FEATURES...FIRST OF WHICH HAS SPAWNED A FEW HOURS OF MODERATE TO LOCALLY HEAVY PRECIP RATES FROM NORTHERN MARYLAND INTO MY SOUTHEAST COUNTIES. THIS IS PROGGED TO EXIT EASTWARD BY LATE AFTERNOON/EVENING BEFORE A MORE BROAD AREA OF BOUNDARY LAYER CONVERGENCE DEVELOPS AS THE UPPER TROF NEARS. 12Z RAP HANDLED THE ONGOING CHANGEOVER QUITE WELL FOR AREAS ALONG THE MD BORDER...AND EXPECT MDT TO BE CHANGING OVER IN THE NEXT HOUR OR TWO...STARTING WITH A MIXTURE OF SLEET AND THEN MAINLY LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. WILL CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO SIGNIFICANTLY DEVIATE. WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE STORM WARNINGS AT THIS TIME...AS AMOUNTS ARE EXPECTED TO REMAIN IN THE .1 TO .15" RANGE OVERALL...WITH SOME APPROACHING .20" ON TOP OF THE 2-4" OF SNOW ACCUM. ELSEWHERE...GOOD CONSISTENCY OF PAST SEVERAL MODEL/ENSEMBLE CYCLES CONTINUES THIS AFTERNOON WITH RESPECT TO PTYPE...WITH BULK OF THIS WINTRY EVENT FALLING AS SNOW TO THE NORTH OF THE RT22/322 CORRIDOR IN CENTRAL PENN. AMOUNTS AND DISTRIBUTION HAVE BEEN TRICKY GIVEN THE LACK OF FORCING FARTHER NORTH...BUT IN GENERAL IT APPEARS THAT 2-4" WILL BE COMMON FOR MOST...WHILE BETTER UPSLOPE AND MOISTURE TRANSPORT INTO THE WEST CENTRAL MOUNTAINS AND LAUREL HIGHLANDS PRODUCE MAX AMOUNTS THERE...GENERALLY UP TO 6" BUT WE COULD SEE SOME SPOT AMOUNTS COME IN HIGHER. TEMPS WILL WILL CONTINUE TO SLOWLY RISE TO A LATE DAY HIGH IN THE UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID 30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY. WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH TODAY. && .SHORT TERM /11 PM THIS EVENING THROUGH MONDAY NIGHT/... PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING THROUGH VERY EARLY MORNING HOURS OF MONDAY. LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE NORTH TO 30F IN ACROSS THE SOUTH. BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL THROUGHOUT THE DAY. DID NOT MAKE ANY LARGE CHANGES TO MONDAY. && .LONG TERM /TUESDAY THROUGH SUNDAY/... HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO. SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO RAIN TUESDAY NIGHT INTO WEDNESDAY. MAIN CHANGE WAS TO ADJUST POPS SOME TUE INTO TUE NIGHT. THINK MAIN TYPE OF PCPN WILL BE RAIN TUE NIGHT INTO WED. DID PUT SMALL AMTS OF .01 ICE ACROSS THE AREA...GIVEN THAT OBJECT TEMPS WILL STILL LIKELY BE COLD. TEMPERATURES TUE NIGHT MAY DROP A LITTLE...BEFORE COMING BACK UP LATE. RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF THE TRAILING COLD FRONT EARLY WEDNESDAY. FOR WED...TOOK SNOW SHOWERS OUT OF THE NW. TIGHT THICKNESS PATTERN ACROSS THE AREA...SUPPORT A LARGE TEMPERATURE GRADIENT FROM NW PA TO SE PA. THERE COULD BE A FEW SHOW SHOWERS ACROSS THE FAR NW...BUT IT LOOKS LIKE MAINLY NW OF OUR AREA. LEFT POPS UP...THINK FRONT WILL BE SLOW TO MOVE OUT. A TREND TOWARD COLDER WEATHER AGAIN LATER IN THE WEEK...GIVEN SPLIT FLOW. PUSH OF ARCTIC AIR WILL BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF FEBRUARY BEHIND. && .AVIATION /21Z SUNDAY THROUGH FRIDAY/... EXPECT BEST RADAR RETURNS TO OCCUR ACROSS CENTRAL AND SOUTHERN PA THIS AFTERNOON AND EVENING IN THE BEST LOW LEVEL CONVERGENCE. MIX TRANSITION TO ICE ACROSS SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ WILL LIFT NORTH OF KMDT MID TO LATE AFTERNOON AS WEAK LOW PRESSURE FROM THE OHIO VALLEY TRACKS EASTWARD INTO THE LAUREL HIGHLANDS AND SECONDARY WEAK LOW PRES FORMS NEAR THE DELMARVA COAST. ACROSS THE NRN MTNS OF PA VSBYS SHOULD AVERAGE NEARLY 1SM HIGHER IN THE LIGHT SNOW. GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS AFT AND THIS EVENING. VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING TO MVFR IN THE CENTRAL AND EAST LATE. CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW SHOWERS. BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY. OUTLOOK... TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE. WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI...MAINLY VFR. && .CLIMATE... THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE COLDEST FEBRUARY ON RECORD. MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9. THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT 21.4 BOTH SET IN 1934. THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT IPT...AND FOURTH COLDEST EVER AT MDT. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027- 028-037-041-042-045-046-049>053-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006- 010>012-017-018-024-033. WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR PAZ025-026-034>036. && $$ SYNOPSIS...DEVOIR/LAMBERT/MARTIN NEAR TERM...DEVOIR/LAMBERT/MARTIN SHORT TERM...DEVOIR/LAMBERT/MARTIN LONG TERM...LA CORTE/LAMBERT/MARTIN AVIATION...DEVOIR/LAMBERT/MARTIN CLIMATE...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
129 PM EST SUN MAR 1 2015 .SYNOPSIS... WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... BRIGHT BANDING AND ELEVATED CCS SHOWING THE PRECIP TRANSITION ZONE WELL AS IT TRANSLATES NORTH OF THE MD BORDER INTO THE SOUTH CENTRAL MOUNTAINS AND FAR LOWER SUSQ RIVER VALLEY. 3" OF NEW SNOW O.G. NEAR GREENCASTLE FROM A TRUSTED WEATHER SPOTTER AND NOW FREEZING RAIN OCCURRING AT 27F. SLEET HAD BRIEFLY MIXED IN EARLIER ACROSS SOUTHERN YORK. A GENERAL 2-4" IS EXPECTED SOUTH OF INTERSTATE 80 AND EAST OF ROUTE 99...WITH THE ADDITIONAL CHANGEOVER TO ICE ACROSS SOUTHERN PORTIONS OF THE SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ RIVER VALLEY ADDING ANOTHER .1 TO .15" OF ICE ON TOP IN THOSE AREAS. OVERALL SCENARIO PLAYING OUT WITH WITH PERIODS OF SNOW (OF VARYING INTENSITY) CONTINUING TO INCREASE IN AREAL COVERAGE THIS AFTERNOON FROM SOUTHWEST TO NORTHEAST. STRONG VERTICAL SHEAR EVIDENT ACROSS THE REGION WITH 150+ KT 250 MB JET SLICING ENE ACROSS THE NORTHERN OHIO VALLEY AND EASTERN GLAKS. BOUNDARY LAYER CONVERGENCE AND FORCING IS BEST ACROSS SOUTHERN PA THIS AFTERNOON AND EVENING...IN VICINITY OF 850 MB JET FEATURES...FIRST OF WHICH HAS SPAWNED A FEW HOURS OF MODERATE TO LOCALLY HEAVY PRECIP RATES FROM NORTHERN MARYLAND INTO MY SOUTHEAST COUNTIES. THIS IS PROGGED TO EXIT EASTWARD BY LATE AFTERNOON/EVENING BEFORE A MORE BROAD AREA OF BOUNDARY LAYER CONVERGENCE DEVELOPS AS THE UPPER TROF NEARS. 12Z RAP HANDLED THE ONGOING CHANGEOVER QUITE WELL FOR AREAS ALONG THE MD BORDER...AND EXPECT MDT TO BE CHANGING OVER IN THE NEXT HOUR OR TWO...STARTING WITH A MIXTURE OF SLEET AND THEN MAINLY LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. WILL CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO SIGNIFICANTLY DEVIATE. WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE STORM WARNINGS AT THIS TIME...AS AMOUNTS ARE EXPECTED TO REMAIN IN THE .1 TO .15" RANGE OVERALL...WITH SOME APPROACHING .20" ON TOP OF THE 2-4" OF SNOW ACCUM. ELSEWHERE...GOOD CONSISTENCY OF PAST SEVERAL MODEL/ENSEMBLE CYCLES CONTINUES THIS AFTERNOON WITH RESPECT TO PTYPE...WITH BULK OF THIS WINTRY EVENT FALLING AS SNOW TO THE NORTH OF THE RT22/322 CORRIDOR IN CENTRAL PENN. AMOUNTS AND DISTRIBUTION HAVE BEEN TRICKY GIVEN THE LACK OF FORCING FARTHER NORTH...BUT IN GENERAL IT APPEARS THAT 2-4" WILL BE COMMON FOR MOST...WHILE BETTER UPSLOPE AND MOISTURE TRANSPORT INTO THE WEST CENTRAL MOUNTAINS AND LAUREL HIGHLANDS PRODUCE MAX AMOUNTS THERE...GENERALLY UP TO 6" BUT WE COULD SEE SOME SPOT AMOUNTS COME IN HIGHER. TEMPS WILL WILL CONTINUE TO SLOWLY RISE TO A LATE DAY HIGH IN THE UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID 30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY. WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING THROUGH VERY EARLY MORNING HOURS OF MONDAY. LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE NORTH TO 30F IN ACROSS THE SOUTH. BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL THROUGHOUT THE DAY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO. SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO RAIN TUESDAY NIGHT INTO WEDNESDAY. RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF THE TRAILING COLD FRONT EARLY WEDNESDAY. EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY OR ANOTHER FOR A SOLUTION. BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF FEBRUARY BEHIND. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... EXPECT BEST RADAR RETURNS TO OCCUR ACROSS CENTRAL AND SOUTHERN PA THIS AFTERNOON AND EVENING IN THE BEST LOW LEVEL CONVERGENCE. MIX TRANSITION TO ICE ACROSS SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ WILL LIFT NORTH OF KMDT MID TO LATE AFTERNOON AS WEAK LOW PRESSURE FROM THE OHIO VALLEY TRACKS EASTWARD INTO THE LAUREL HIGHLANDS AND SECONDARY WEAK LOW PRES FORMS NEAR THE DELMARVA COAST. ACROSS THE NRN MTNS OF PA VSBYS SHOULD AVERAGE NEARLY 1SM HIGHER IN THE LIGHT SNOW. GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS AFT AND THIS EVENING. VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING TO MVFR IN THE CENTRAL AND EAST LATE. CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW SHOWERS. BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY. OUTLOOK... MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS. TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE. WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. && .CLIMATE... THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE COLDEST FEBRUARY ON RECORD. MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9. THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT 21.4 BOTH SET IN 1934. THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT IPT...AND FOURTH COLDEST EVER AT MDT. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027- 028-037-041-042-045-046-049>053-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006- 010>012-017-018-024-033. WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR PAZ025-026-034>036. && $$ SYNOPSIS...DEVOIR/LAMBERT NEAR TERM...DEVOIR/LAMBERT SHORT TERM...DEVOIR/LAMBERT LONG TERM...LA CORTE/LAMBERT AVIATION...DEVOIR/LAMBERT CLIMATE...
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1054 AM MST SUN MAR 1 2015 .UPDATE... ISSUED AT 1055 AM MST SUN MAR 1 2015 NO CHANGES TO THE FORECAST TODAY. MAIN FOCUS REMAINS ON THE STORM SYSTEM WHICH WILL MOVE ACROSS THE AREA TOMORROW AND TOMORROW NIGHT. MODELS NOT IN GREAT AGREEMENT WITH WHERE THE HEAVIEST SNOW WILL FALL...BUT THERE IS GENERAL CONSENSUS POINTS TO SOUTH CENTRAL WYOMING. CURRENT WATER VAPOR AND RADAR OVER THE SOUTHWEST CONUS SHOWING MOISTURE STREAMING NORTHEASTWARD FROM ARIZONA. SEEMS REASONABLE THERE WILL BE WIDESPREAD SNOW ACROSS THE ENTIRE AREA BY MONDAY NIGHT AS AN UPPER LEVEL DISTURBANCE MOVES FROM THE CENTRAL ROCKIES INTO THE NORTHERN PLAINS. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 400 AM MST SUN MAR 1 2015 LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE SINGLE DIGITS AND TEENS WITH LIGHT WINDS. FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING AT THE 12Z/18Z MODEL GUIDANCE. HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS. MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE 30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE WAKE OF THE COLD FRONTAL PASSAGE. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 AM MST SUN MAR 1 2015 THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM. IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF 60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH OF THAT TIME PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH MONDAY MORNING) SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH GENERALLY MVFR CONDITIONS PREVAILING ALONG I80...AND VFR FURTHER NORTH ACROSS WESTERN NEBRASKA. A WARM FRONT WILL SLOWLY MOVE NORTHWARD ACROSS THE AREA TONIGHT...BRINGING ANOTHER ROUND OF SNOW TO AREAS ALONG I80. LOW MVFR TO IFR CIGS/VSBYS ARE LIKELY AFTER 06Z TONIGHT. WINDS WILL GENERALLY BE LIGHT THROUGH THE TAF PERIOD BUT WILL INCREASE OUT OF THE SOUTH LATE TONIGHT AND INTO EARLY MONDAY MORNING. && .FIRE WEATHER... ISSUED AT 321 AM MST SUN MAR 1 2015 A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE. A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT FOR WYZ111>114. NE...NONE. && $$ UPDATE...SML SHORT TERM...MAJ LONG TERM...CLH AVIATION...TJT FIRE WEATHER...MAJ