Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/09/14


AREA FORECAST DISCUSSION
NWS EUREKA CA
453 AM PST SUN DEC 7 2014 .SYNOPSIS...A LOW PRESSURE SYSTEM WILL APPROACH THE COAST TODAY BRINGING LIGHT TO MODERATE RAIN BY THIS EVENING. A CHANCE OF RAIN WILL PERSIST MONDAY THROUGH TUESDAY. A STRONGER STORM WILL ARRIVE AROUND MID WEEK AND PROMISES TO BRING HEAVY RAIN WEDNESDAY NIGHT INTO THURSDAY. && .DISCUSSION...SATELLITE IMAGERY SHOWED A SHORTWAVE TROUGH JUST OUTSIDE 130W EARLY THIS MORNING. ALL THE MODELS HAVE SLOWED DOWN THE ARRIVAL OF THE RAIN WITH THIS TROUGH TIL LATE THIS AFTERNOON INTO THIS EVENING. THE 6Z NAM12 AND 6Z GFS SPED UP THE ARRIVAL SOME...HOWEVER IT STILL LOOKS LIKE MOST OF THE PRECIP WILL ARRIVE AFTER ABOUT 5 PM. THE HRRR MODEL DOES SHOW SOME RETURNS SPIKING UP OVER THE INTERIOR THIS AFTERNOON...BUT HAS THE BRUNT OF THE REFLECTIVITIES STILL OFFSHORE OVER THE COASTAL WATERS AROUND 4PM. SOUTHEASTERLY AND EASTERLY WINDS WILL RAMP UP THIS AFTERNOON AS THE TROUGH LINE APPROACHES THE COAST. WINDS WERE ALREADY A BIT BREEZY OVER THE RIDGES AND GUSTS TO 20-30 MPH DOWN TO MEAN SEA LEVEL CAN BE EXPECTED. THE WEAKENING SHORTWAVE WILL MOVE ACROSS THE AREA THIS EVENING AND PROBABLY PRODUCE A TENTH TO A QUARTER OF AN INCH OF RAIN. ALSO THE MODELS NO LONGER INDICATE THAT THE TROUGH WILL ACQUIRE A NEGATIVE TILT. THE GFS STILL SHOWS WEAK INSTABILITY OVER THE FAR WESTERN PERIPHERY OF MARINE ZONE 475 TODAY...SO LEFT THE SLIGHT CHANCE OF THUNDERSTORMS IN THE GRIDS THERE. THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT ON HOW QUICKLY THE RAIN WILL END OR DECREASE TONIGHT. THE GFS, ECMWF AND NAM12 DO SHOW LINGERING LIGHT PRECIP IN MENDO COUNTY AND IN EASTERN TRINITY...SO MAINTAINED SLIGHTLY HIGHER PRECIP CHANCES THERE TIL EARLY MONDAY MORNING. MODELS DO SHOW ANOTHER SHORTWAVE TROUGH MOVING TOWARD THE AREA ON MONDAY WHICH MAY BRING MORE SHOWERS BY MON NIGHT. MOIST SOUTHWESTERLY FLOW WILL INCREASE ON TUE AS ANOTHER SHORTWAVE TROUGH MOVES TOWARD THE AREA. RAIN CHANCES APPEAR TO INCREASE ON TUE...HOWEVER THE MODELS WERE NOT IN VERY GOOD AGREEMENT ON THE PRECIP. BEST CHANCES AND HIGHEST AMOUNTS LOOK TO BE IN DEL NORTE COUNTY. CONFIDENCE IS NOT HIGH AS THE MODELS WERE NOT IN GREAT AGREEMENT AND KEEP CHANGING AROUND FROM ONE RUN TO THE NEXT. SO DID NOT MAKE TOO MANY ADJUSTMENTS FOR TUE. A RAINY AND WINDY STORM SYSTEM REMAINS ON TRACK TO IMPACT NORTHWEST CALIFORNIA STARTING ON WEDNESDAY...WITH WET AND UNSETTLED WEATHER CONDITIONS CONTINUING THROUGH THE REMAINDER OF THE WEEK. THE 0Z RUNS OF THE GFS AND ECMWF WERE GOOD AGREEMENT BRINGING RAIN INTO THE COAST BY THE AFTERNOON ON WEDNESDAY. RAIN WILL OVERSPREAD THE AREA OVERNIGHT WED INTO THURSDAY. AN UPPER TROUGH WILL MOVE TOWARD THE COAST THURSDAY INTO FRIDAY AND EXPECT SHOWERS TO CONTINUE. AMPLE DEEP LAYER MOISTURE CONTINUES TO BE INDICATED WITH THIS SYSTEM WITH HIGH PWAT VALUES. THERE WILL LIKELY BE PERIODS OF MODERATE TO HEAVY RAIN. ON FRIDAY...THE GFS HAS SHOWERS CONTINUING OVER THE AREA WITH GOOD INSTABILITY PRESENT. HAVE KEPT ANY MENTION OF THUNDERSTORMS OUT OF THE FORECAST AT THIS POINT. SNOW LEVELS WILL START OFF NEAR 7K FEET ON WEDNESDAY AND GRADUALLY FALL TO BETWEEN 4KFT FEET BY FRIDAY IF THE GFS IS CORRECT. THE LAST COUPLE RUNS OF THE GFS AND ECMWF HAVE BEEN IN GOOD AGREEMENT SHOWING THE TROUGH MOVING THROUGH FRI NIGHT. ISOLATED SHOWERS MAY STILL DEVELOP IN THE COOLER AIR AND NW FLOW BEHIND THE UPPER TROUGH ON SAT...SO LEFT A SLIGHT CHANCE OF PRECIP IN THE FORECAST. IF THE MODELS ARE CORRECT...TEMPERATURES WILL COOL DOWN FRI INTO SAT AS THE TROUGH EXITS TO THE EAST. A COASTAL FLOOD ADVISORY HAS BEEN ISSUED FROM 10 AM TO 2 PM TODAY FOR MINOR FLOODING OF LOW LYING AREAS AROUND HUMBOLDT BAY DUE TO A HIGH ASTRONOMICAL TIDE. IMPACTS ARE EXPECTED TO BE MARGINAL AS THE TIDE IS FORECAST TO BE 7.76 FT WITH AN ANOMALY AROUND 1 FT. THE CRITERIA FOR AN ADVISORY IS 8.8 FT. HIGH TIDE WILL OCCUR AT 11:30 AM TODAY WITH WATER LEVELS APPROACHING 8.8 FT. WE ANTICIPATE THE FLOODING THREAT TO DIMINISH NEXT WEEK BUT A HIGH TIDAL ANOMALY ON MONDAY COULD RESULT IN MORE COASTAL FLOODING. && .AVIATION...LOW CLOUDS AND FOG ACROSS THE INTERIOR VALLEYS WILL SCOUR OUT TODAY AS STRONG SOUTHERLY FLOW DEVELOPS AHEAD OF A COLD FRONT. OTHERWISE CONDITIONS ARE EXPECTED TO REMAIN VFR THROUGH MUCH OF THE DAY. THE COLD FRONT WILL BRING PERIODS OF IFR DURING HEAVY RAIN BANDS. OTHERWISE LOOK FOR LOWER CLOUD DECKS THROUGH THE DAY AND STRONG SOUTHERLY WINDS ALONG THE COAST. BFG && .MARINE...A SERIES OF FRONTS WILL SWEEP OVER THE COASTAL WATERS THIS WEEK WITH STRONG TO GALE FORCE SOUTHERLY WINDS PRECEDING. STEEP SOUTHERLY WAVES WILL ACCOMPANY THESE INCREASING WINDS. THE FIRST FRONT WILL CAUSE BUILDING CONDITIONS TODAY INTO EARLY MONDAY THEN SUBSIDE SLIGHTLY ON MONDAY. CONDITIONS WILL AGAIN DETERIORATE MIDWEEK AS ANOTHER STRONG FRONT APPROACHES THE WATERS. THE MODELS SEEM TO BE IN GOOD AGREEMENT WITH THIS PATTERN, SO HAVE FOLLOW MODEL GUIDANCE FOR THE FORECAST. AN ACTIVE STORM TRACK IS ENTRENCHED OVER THE NORTHERN PACIFIC WITH A CORE OF WINDS POINTING AT THE WEST COAST OF THE UNITED STATES. THIS IS CAUSING LARGE WAVES WHICH ARE PROPAGATING TOWARD THE COAST. WAVES MODELS ARE SHOWING FORERUNNERS ARRIVING ON TUESDAY THEN BUILDING QUICKLY INTO WEDNESDAY. THIS WESTERLY SWELL COULD REACH AS HIGH AS 18 FT AT 14 SECONDS ON WEDNESDAY. COMBINE THIS WITH GALES OUT OF THE SOUTH AND THE ASSOCIATED STEEP WAVES AND COMBINED SEAS MAY REACH AS HIGH AS 20 TO 24 FEET. LATE WEEK, MODELS ARE NOT IN GOOD AGREEMENT MAKING FOR A LOW CONFIDENCE FORECAST. OVERALL IT WILL BE A ROUGH WEEK FOR THE COASTAL WATERS. BFG && .EKA WATCHES/WARNINGS/ADVISORIES... CA... COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 2 PM PST THIS AFTERNOON FOR CAZ001. NORTHWEST CALIFORNIA COASTAL WATERS... COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 2 PM PST THIS AFTERNOON FOR PZZ410. SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 3 AM PST MONDAY FOR PZZ455. SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM PST MONDAY FOR PZZ450. SMALL CRAFT ADVISORY UNTIL 9 AM PST THIS MORNING FOR PZZ470-475. GALE WARNING FROM 9 AM THIS MORNING TO 9 PM PST THIS EVENING FOR PZZ470. GALE WARNING FROM 9 AM THIS MORNING TO 3 PM PST THIS AFTERNOON FOR PZZ475. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/NWSEUREKA HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS ALBANY NY
951 PM EST MON DEC 8 2014 .SYNOPSIS... AS A DEVELOPING COASTAL STORM APPROACHES OUR AREA....A LONG DURATION PERIOD OF RAIN AND SNOW...AND POSSIBLY SLEET AND FREEZING RAIN...WILL IMPACT THE REGION BETWEEN LATE TONIGHT TUESDAY AND THURSDAY AS THE COASTAL STORM SITS AND SPINS CLOSE TO OUR REGION. THE HEAVIEST PRECIPITATION ASSOCIATED WITH THIS STORM IS EXPECTED TUESDAY AND TUESDAY EVENING. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 950 PM EST...DELAYED ONSET OF STEADY PRECIPITATION BY A FEW HOURS...AS HI RES MODELS SUCH AS THE HRRR AND LOCAL WRF LIKELY LATCHING ON TO SIGNIFICANT DRY WEDGE ALOFT EVIDENT ON KALB SOUNDING BETWEEN 5-20 KFT. SO IT WILL TAKE SOME TIME TO SATURATE THE COLUMN AND ALLOW FOR PRECIP TO REACH THE GROUND. SO LOWERED POPS CONSIDERABLY THROUGH 4 AM...WITH POPS INCREASING TO CHANCE/LIKELY VALUES SOUTH OF ALBANY BETWEEN 4 AND 6 AM. WILL STILL ALLOW THE WINTER WEATHER ADVISORY FOR FAR SOUTHERN AREAS TO BEGIN AT 1 AM DUE TO THE POTENTIAL FOR PATCHY FREEZING DRIZZLE BEFORE THE MAIN EVENT BEGINS. WINTER WEATHER HEADLINES REMAIN THE SAME FOR NOW AS WE EXAMINE THE LATEST DATA...ALTHOUGH THE AREA CURRENTLY UNDER A WINTER STORM WATCH WILL BE EITHER UPGRADED TO A WARNING OR ADVISORY BEFORE DAWN. FOR THE REST OF THE REGION WINTER STORM WARNING AND WATCHES WILL START AT 400 AM...AND WILL BE DISCUSSED IN THE SHORT TERM SECTION. LOWS TONIGHT WILL OCCUR EARLY TONIGHT AND BE IN THE UPPER TEENS AND 20S...THEN SLOWLY RISE 3 TO 4 DEGREES BY SUNRISE TUESDAY. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... VERY COMPLEX WINTER STORM WILL HAVE A LARGE IMPACT ON THE REGION THROUGH THE ENTIRE SHORT TERM PERIOD...ESPECIALLY TUESDAY AND EARLY TUESDAY NIGHT. HAVE UPGRADED THE WESTERN AND SOUTHERN ADIRONDACKS...THE MOHAWK AND SCHOHARIE VALLEYS AND THE EASTERN CATSKILLS TO WINTER STORM WARNINGS THROUGH 12Z WEDNESDAY...WITH SNOWFALL AMOUNTS OF 7 TO 14 INCHES...ALONG WITH SOME MIXED PCPN POSSIBLE. THE LOWEST TERRAIN AREAS IN THESE REGIONS MAY NOT EXCEED 7 INCHES OF SNOW DUE TO THE MIXING OF PCPN WITH SLEET...FREEZING RAIN AND RAIN...BUT ON AVERAGE MOST AREAS WILL GET HEAVY SNOW. DUE TO THE EXTREMELY TIGHT GRADIENT IN TEMPERATURES ACROSS THE REGION...AND THE MINOR TEMPERATURE VARIATIONS THAT OCCUR BETWEEN EACH MODEL...AND EVEN BETWEEN DIFFERENT RUNS OF THE SAME MODEL... HAVE DECIDED THAT THERE IS STILL TOO MUCH UNCERTAINTY TO MAKE A DECISION BETWEEN A WARNING OR AN ADVISORY FOR A LARGE PART OF THE FORECAST AREA THAT INCLUDES THE SARATOGA REGION...CAPITAL DISTRICT... THE UPPER PART OF THE MID HUDSON VALLEY...THE TACONICS...SOUTHERN VERMONT AND BERKSHIRE COUNTY. THIS WAS COORDINATED WITH SURROUNDING OFFICES TO THE EAST WHO ALSO KEPT ADJOINING PARTS OF THEIR FORECAST AREAS IN THE WINTER STORM WATCH. FOR NOW HAVE GENERALLY FORECAST 3 TO 10 INCHES IN THE WATCH AREA...WITH MOST AREAS GENERALLY FORECAST TO GET 7 INCHES OR LESS... EXCEPT FOR THE HIGHER TERRAIN OF SOUTHERN VERMONT. MOST OF THE PCPN WILL OCCUR ON TUESDAY...WITH A LARGE DRY SLOT SURGING NORTHWARD AND CUTTING OFF THE STEADIEST AND HEAVIEST PCPN EARLY TUESDAY NIGHT. WITH THE UPPER LOW EVENTUALLY PARKING ITSELF OVER EASTERN NY... OCCASIONAL LIGHT SNOW WILL LIKELY CONTINUE WEDNESDAY AND THURSDAY AS WELL. THERE COULD STILL BE SOME MIXED PCPN WEDNESDAY...BUT ALL SNOW IS EXPECTED WEDNESDAY NIGHT. HIGHS TUESDAY WILL BE 30 TO 40. LOWS TUESDAY NIGHT IN THE MID 20S TO LOWER 30S. HIGHS WEDNESDAY GENERALLY IN THE 30S. LOWS WEDNESDAY NIGHT 20 TO 30. && .LONG TERM /THURSDAY THROUGH MONDAY/... WE WILL STILL BE DEALING WITH A CUT-OFF UPPER LEVEL LOW WHICH WILL BE CENTERED RIGHT OVER THE REGION ON THURSDAY...BUT THE SYSTEM WILL HAVE LOST ITS BAROCLINICITY BY THEN RESULTING IN MAINLY SCATTERED TO LIKELY SNOW SHOWERS. BEST CHANCE FOR ANY LIGHT MEASURABLE SNOWFALL WILL BE OVER THE HIGHER TERRAIN WEST AND EAST OF THE HUDSON RIVER VALLEY. THE CUT-OFF LOW WILL ONLY SLOWLY MEANDER TO THE EAST-NORTHEAST THURSDAY NIGHT INTO FRIDAY...WITH THE CORE MOVING INTO NEW ENGLAND. OUR AREA WILL CONTINUE TO BE UNDER THE INFLUENCE OF THE CYCLONIC FLOW ASSOCIATED WITH THIS SYSTEM...ALTHOUGH DRIER AIR WILL GRADUALLY WORK IN FROM THE WEST...ESPECIALLY ON FRIDAY AS WE WILL BE ON THE WESTERN PERIPHERY OF THE CIRCULATION. SO WILL CONTINUE TO MENTION CHANCE POPS FOR SNOW SHOWERS THURSDAY NIGHT...DECREASING TO SLIGHT CHANCE IN THE VALLEYS FOR FRIDAY. THERE WILL CONTINUE TO BE A SOMEWHAT BETTER CHANCE FOR A PASSING SNOW SHOWER OVER THE HIGHER TERRAIN ON FRIDAY WITH THE NORTHWEST CYCLONIC FLOW PERSISTING. IT LOOKS LIKE DRIER WEATHER WILL FINALLY PREVAIL FOR THE WEEKEND...ALTHOUGH THE DEGREE OF CLOUD COVER WILL DEPEND ON HOW QUICKLY THE CUT-OFF LOW MOVES OUT TO SEA. THE ECMWF IS RATHER SLOW WITH THE DEPARTURE OF THE CUT-OFF LINGERING CYCLONIC FLOW UNTIL SUNDAY...WHILE THE GFS HAS AN UPPER LEVEL RIDGE BUILDING IN BY LATE SATURDAY. AGAIN...THIS WILL HAVE IMPLICATIONS ON CLOUD COVER BUT WE ARE EXPECTING PRECIP-FREE CONDITIONS THROUGH THE UPCOMING WEEKEND. DESPITE RISING UPPER LEVEL HEIGHTS/TEMPS...SURFACE TEMPS ARE ONLY EXPECTED TO BE SLIGHTLY ABOVE NORMAL DUE TO EXPECTED SHALLOW MIXING THIS TIME OF YEAR. TRANQUIL WEATHER LOOKS TO CONTINUE INTO MONDAY...WITH HIGH PRESSURE AT THE SURFACE AND ALOFT FIRMLY ENTRENCHED OVER THE REGION WITH GOOD AGREEMENT BETWEEN THE ECMWF/GFS. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... A SIGNIFICANT DEVELOPING COASTAL STORM WITH MULTIPLE PRECIPITATION TYPES WILL IMPACT THE AREA FROM EARLY TUESDAY MORNING INTO WEDNESDAY MORNING. SOLID STRATUS CLOUD DECK WITH CIGS IN MVFR RANGE IN PLACE ACROSS THE TERMINALS THIS EVENING DUE TO AN INCREASINGLY MOIST E-SE LOW LEVEL FLOW. A FEW SNOW FLURRIES WILL BE POSSIBLE THIS EVENING BUT WILL NOT AFFECT THE VISIBILITY SO WILL JUST MENTION VCSH. PRECIP ASSOCIATED WITH COASTAL STORM WILL DEVELOP FROM SOUTH TO NORTH ACROSS THE AREA STARTING SHORTLY BEFORE SUNRISE AT KPOU...TO MID MORNING AT KGFL. CONDITIONS WILL RAPIDLY DETERIORATE TO IFR/LIFR SHORTLY AFTER PRECIP COMMENCES. A WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN IS ANTICIPATED TO START AT KPOU...CHANGING TO RAIN SHORTLY AFTER SUNRISE. SNOW WILL DEVELOP AT KALB/KPSF/KGFL AROUND 12Z-14Z...THEN QUICKLY CHANGE TO A MIX OF SNOW...SLEET AND FREEZING RAIN AND EVENTUAL RAIN BY NOON AT KALB/KPSF. MODERATE TO HEAVY RAIN WILL THE FALL THROUGH THE AFTERNOON...POSSIBLY MIXED WITH SLEET. A WINTRY MIX IS EXPECTED TO PREVAIL WELL INTO THE AFTERNOON AT KGFL. THE PRECIP TYPE FORECASTS AND TIMING ARE LOW CONFIDENCE AT THIS TIME...AS TEMPERATURE PROFILES IN THE ATMOSPHERE ARE UNCERTAIN. LOW LEVEL COLD AIR MAY SCOUR OUT QUICKER THAN ANTICIPATED OR LINGER LONGER INTO THE AFTERNOON...WHICH WOULD IMPACT WHEN PRECIP TYPE TRANSITIONS OCCUR. WINDS WILL INITIALLY BE N-NE AROUND 5-10 KTS...INCREASING TO 10-15 KTS WITH GUST NEAR OR EXCEEDING 20 KTS TUESDAY AFTERNOON. OUTLOOK... TUESDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN...SLEET. WEDNESDAY: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SN. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. FRIDAY NIGHT TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... FLOOD WATCH FOR DUTCHESS AND EASTERN ULSTER COUNTIES ALONG WITH LITCHFIELD COUNTY WHERE 1 TO 2 INCHES OF QPF ARE IN THE FORECAST WITH MAINLY RAIN. A COASTAL STORM WILL BRING WIDESPREAD PRECIPITATION TO THE REGION BEGINNING EARLY IN THE DAY ON TUESDAY AND CONTINUING INTO TUESDAY NIGHT. FOR NORTHWESTERN AND HIGH TERRAIN AREAS...THIS PRECIPITATION WILL FALL PRIMARY AS SNOW OR A WINTRY MIX. MEANWHILE...ACROSS SOUTHERN AND VALLEY AREAS...PRECIP WILL BEGIN AS A PERIOD OF SNOW AND TRANSITION TO A WINTRY MIX AND THEN RAIN. TOTAL LIQUID EQUIVALENT VALUES WILL BE 0.75 OVER THE WESTERN ADIRONDACKS TO ABOUT 2 INCHES OVER WESTERN NEW ENGLAND. WITH MUCH OF THIS FALLING AS RAINFALL OVER LITCHFIELD COUNTY...THERE WILL BE A LOT OF RUNOFF...ESPECIALLY DURING TUESDAY AFTERNOON INTO TUESDAY EVENING WHICH PRECIP WILL BE HEAVIEST. THIS RAINFALL MAY LEAD TO MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS...ESPECIALLY IN AREAS WHERE THE GROUND IS FROZEN. RISES ON RIVERS AND STREAMS ARE LIKELY...AND MINOR FLOODING CANNOT BE RULED OUT ON THE HOUSATONIC RIVER AND IT/S TRIBUTARIES IN NW CT. AS A RESULT...A FLOOD WATCH IS IN EFFECT FOR LITCHFIELD COUNTY. ELSEWHERE...MINOR FLOODING OF LOW LYING AREAS CANNOT BE RULED OUT EITHER...SUCH AS IN THE MID HUDSON VALLEY AND TACONICS...BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE THESE AREAS IN THE FLOOD WATCH AT THIS TIME. PART OF THIS UNCERTAINTY IS DUE TO QUESTIONS REMAINING OF HOW LONG PRECIP WILL BE WINTRY VS PLAIN RAINFALL. WHEN THE EXACT DURATION OF PRECIP TYPES BECOME MORE CLEAR...IT IS POSSIBLE THAT THE FLOOD WATCH MAY NEED TO BE EXPANDED. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH FROM 6 AM EST TUESDAY THROUGH LATE TUESDAY NIGHT FOR CTZ001-013. WINTER WEATHER ADVISORY UNTIL 11 AM EST TUESDAY FOR CTZ001-013. NY...WINTER STORM WARNING FROM 4 AM TUESDAY TO 7 AM EST WEDNESDAY FOR NYZ032-033-038>040-042-043-047-048-051-058-063-082. WINTER STORM WATCH FROM 4 AM EST TUESDAY THROUGH WEDNESDAY MORNING FOR NYZ041-049-050-052>054-059>061-083-084. FLOOD WATCH FROM 6 AM EST TUESDAY THROUGH LATE TUESDAY NIGHT FOR NYZ064>066. WINTER WEATHER ADVISORY UNTIL 11 AM EST TUESDAY FOR NYZ064>066. MA...WINTER STORM WATCH FROM 4 AM EST TUESDAY THROUGH WEDNESDAY MORNING FOR MAZ001-025. VT...WINTER STORM WATCH FROM 4 AM EST TUESDAY THROUGH WEDNESDAY MORNING FOR VTZ013>015. && $$ SYNOPSIS...GJM NEAR TERM...GJM/JPV SHORT TERM...GJM LONG TERM...JPV AVIATION...JPV HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
359 AM EST SUN DEC 7 2014 .SYNOPSIS... DRY BUT MUCH COLDER AND BLUSTERY WEATHER TODAY...LINGERING INTO MONDAY. A LOW PRESSURE SYSTEM WILL MOVE INTO SOUTHERN NEW ENGLAND TUESDAY AND LINGER THERE THROUGH THE MIDDLE OF THE WEEK. DRY WEATHER RETURNS BY FRIDAY AND SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ANY EARLY MORNING PRECIP SHOULD BE CONFINED TO CAPE COD AND THE ISLANDS AND MOVING QUICKLY OFFSHORE AS A COLD FRONT MOVES ACROSS SOUTHERN NEW ENGLAND. AGAIN PRECIP COULD END AS A BRIEF PERIOD OF SNOW AND/OR SLEET. LATEST RUNS OF THE HRRR LOOK TO HAVE A GOOD TIMING FOR THE BACK EDGE...SO LEANED HEAVILY UPON THAT TIMING. LOW PROBABILITY OF SOME SLICK SPOTS EARLY THIS MORNING ALONG AND NORTHWEST OF I-95 IN MA AND RI AS TEMPERATURES FALL AT OR BELOW FREEZING AND COMBINE WITH ANY RESIDUAL MOISTURE ON THE ROADS. GOOD POST FRONTAL MIXING MAY DRY THINGS OUT FAIRLY QUICKLY. BEHIND THIS FRONT...DRY CONDITIONS BUT WINDY AND MUCH COLDER WITH NNE WINDS 15 TO 25 MPH GUSTING UP TO 35 MPH...EXCEPT UP TO 50 MPH ACROSS CAPE COD AND ISLANDS. CLEARING WILL BE BRIEF...AS NNE FLOW YIELDS LOTS OF OCEAN-EFFECT STRATOCUMULUS CLOUDS ACROSS EASTERN MA. AT LEAST PARTLY SUNNY ELSEWHERE. THE BIG QUESTION IS WILL THERE BE ENOUGH OF A TEMPERATURE DIFFERENTIAL. WITH WATER TEMPERATURES IN THE UPPER 40S...ONLY GETTING MAX DIFFERENTIALS ABOUT -5C TO -7C. THAT IS TYPICALLY NOT ENOUGH TO GENERATE SUFFICIENT OCEAN-INDUCED CAPE. THERE IS ALSO THE PROBLEM OF THE SIGNIFICANT SUBSIDENCE INVERSION BASED AROUND 950 MB WITH ABUNDANT DRY AIR ABOVE IT. THAT LEAVES ONLY A VERY SHALLOW LAYER FOR ANY SHOWERS TO DEVELOP. LEFT A CHANCE OF SNOW/SLEET SHOWERS IN THE FORECAST...BUT IT IS THE LOWEST CONFIDENCE PORTION OF THIS FORECAST. OTHERWISE...THERE SHOULD BE ENOUGH OF A PRESSURE GRADIENT BETWEEN THE DEPARTING LOW PRESSURE AND A STRONG HIGH PRESSURE OVER SOUTHEAST CANADA TO GENERATE STRONG NORTH TO NORTHEAST WINDS ACROSS CAPE COD AND THE ISLANDS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... STRONG HIGH PRESSURE CONTINUES TO MOVE INTO THE MARITIMES AND NORTHERN NEW ENGLAND TONIGHT. EXPECTING COLD CONDITIONS ACROSS ALL OF SOUTHERN NEW ENGLAND....WITH GUSTY WINDS LINGERING ACROSS CAPE COD AND THE ISLANDS. WINDS DIMINISH SOME MONDAY. SREF AND HIGH RESOLUTION WRF CONTINUE TO HAVE HIGHER PRECIPITATION CHANCES THAN JUST ABOUT ALL OTHER GUIDANCE. THIS COULD BE A FUNCTION OF THE HIGHER RESOLUTION OF THE WRF MEMBERS. STILL SEEING THE SAME ISSUES WITH OCEAN-EFFECT SHOWERS...THAT BEING THE STRONG SUBSIDENCE INVERSION AND DEEP DRY AIR. MAINTAINED A CHANCE OF SHOWERS ACROSS EASTERN MA AND PORTIONS OF RI FOR NOW...AND WILL CONTINUE TO EVALUATE THIS POTENTIAL. AFTER A VERY COLD START MONDAY MORNING...WILL SEE AFTERNOON HIGH TEMPERATURES STAY BELOW NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGHLIGHTS... * LOW PRESSURE WILL BRING UNSETTLED MOSTLY RAINY WEATHER TO THE AREA THROUGHOUT THE MIDDLE OF THE WEEK * DRY WEATHER RETURNS BY FRIDAY AND SATURDAY THE MODELS...WHILE CONTINUING TO STRUGGLE WITH A LOW PRESSURE SYSTEM APPROACHING SOUTHERN NEW ENGLAND...ARE COMING INTO BETTER AGREEMENT. THE ECMWF HAS BEEN MORE CONSISTENT WITH A DEEP...SOMETIMES NEGATIVELY TILTED MID LEVEL TROUGH PULLING A COASTAL LOW IN TOWARDS SOUTHERN NEW ENGLAND. THE LOW THEN ROTATES AROUND THE AREA FOR SEVERAL DAYS. THE 06/00Z GFS IS FINALLY IN BETTER AGREEMENT WITH THE ECMWF...THOUGH IT IS A BIT MORE PROGRESSIVE. FINALLY...THE GEFS MEMBERS SHOW A LOW PRESSURE SYSTEM AFFECTING SOUTHERN NEW ENGLAND BUT ALL WITH SOMEWHAT DIFFERENT TRACKS AND SPEEDS. THEREFORE GIVEN ITS CONSISTENCY...FEEL THE ECMWF SOLUTION IS THE WAY TO GO. TUESDAY THROUGH THURSDAY...AS STATED ABOVE...WE ARE SEEING BETTER AGREEMENT WITH THIS SYSTEM. THERE IS STILL SOME UNCERTAINTY AS TO HOW PROGRESSIVE THE STORM WILL BE. AS THE LOW PRESSURE SYSTEM INTENSIFIES...AN ANOMALOUSLY STRONG /3 TO 4 STD/ EASTERLY LOW LEVEL JET DEVELOPS...RESULTING IN PLENTY OF MOISTURE AND STRONG FORCING. WHILE THE MAIN CONCERN IS TUESDAY...THERE IS POTENTIAL FOR THIS STORM TO LINGER THROUGH THURSDAY SO WILL KEEP ALL TOGETHER FOR NOW. SNOW...WHILE HIGH PRESSURE IS IN THE MARITIMES /NOT AN IDEAL LOCATION FOR COLDER AIR FILTERING INTO SOUTHERN NEW ENGLAND/... THERMAL PROFILES ARE ISOTHERMAL ACROSS THE NORTHWESTERN ZONES. THEY ARE RIGHT AT ZERO DEGREES SO A SMALL SHIFT IN EITHER DIRECTION IS GOING TO BE THE DIFFERENCE BETWEEN SNOW AND RAIN. STRONG FORCING MEANS EITHER SNOW OR RAIN COULD BE QUITE HEAVY WITH 2 INCH PER HOUR SNOWFALL RATES POSSIBLE. HOWEVER...THIS IS STILL A LOW CONFIDENCE SITUATION. HEAVY RAIN...TEMPERATURE PROFILES ARE SUCH THAT WE ARE EXPECTING MOSTLY RAIN ACROSS THE AREA. WITH THE LOW MOVING AS SLOWLY AS IT IS ON THE ECMWF SOLUTION...WE ARE LOOKING AT A PROLONGED PERIOD OF RAIN WITH WIDESPREAD RAINFALL AMOUNTS OF TWO TO THREE INCHES. WHILE THIS WILL NOT BE ENOUGH FOR ANY RIVER FLOODING...THIS WILL LIKELY RESULT IN SOME URBAN/POOR DRAINAGE FLOODING. BECAUSE OF THE FORCING ASSOCIATED WITH THE 3-4 STANDARD DEVIATION LOW LEVEL JET...MUCH OF THIS RAIN COULD FALL OVER A SHORT PERIOD OF TIME. WIND...WITH THIS ANOMALOUSLY STRONG LOW LEVEL JET...EXPECTING EASTERLY WINDS AT THE SURFACE GUSTING TO AT LEAST 45 MPH...IF NOT HIGHER ALONG THE EAST COAST...CAPE...AND ISLANDS. THERE IS ALSO A LOW PROBABILITY OF HIGH WIND CRITERIA /60 MPH GUSTS OR HIGHER/. THERE IS POTENTIAL FOR COASTAL FLOODING AS WELL. SEE TIDES/COASTAL FLOODING SECTION BELOW FOR MORE INFORMATION. FRIDAY AND SATURDAY...AT THIS POINT BOTH MODELS HAVE A RETURN TO DRIER WEATHER WITH HIGH PRESSURE SLOWLY BUILDING INTO THE REGION. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. TODAY...VFR EXCEPT LINGERING IFR/MVFR OVER CAPE COD AND ISLANDS EARLY. NE WINDS GUSTING UP TO 45 KT OVER CAPE COD AND ISLANDS. IFR/MVFR RETURN TO EASTERN MA IN THE AFTERNOON AS SNOW SHOWERS OVER EASTERN MA WATERS COME ONSHORE. TONIGHT...VFR EXCEPT IFR/MVFR ACROSS EASTERN MA IN SCATTERED SNOW SHOWERS ALONG WITH NE WINDS G35 KT...HIGHEST CAPE COD AND ISLANDS. SOME MINOR ACCUMULATION POSSIBLE ACROSS PORTIONS OF EASTERN MA. MONDAY...MODERATE CONFIDENCE. MVFR CONDITIONS SPREAD INLAND FROM THE COAST AS THE DAY WEARS ON WITH ONSHORE FLOW. EVEN SOME IFR CIGS POSSIBLE ALONG THE COAST FOR A TIME IN A FEW RAIN/SNOW SHOWERS. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... MONDAY NIGHT...MODERATE CONFIDENCE. MVFR CONDITIONS LIKELY WITH IFR CIGS POSSIBLE ALONG THE COAST FOR A TIME IN A FEW RAIN/SNOW SHOWERS. TUESDAY...MODERATE CONFIDENCE. MVFR-IFR CONDITIONS EXPECTED IN MAINLY RAIN...WITH PERHAPS A PERIOD OF HEAVY WET SNOW ACROSS NORTHWEST MA/NORTH CENTRAL MA. NORTHEAST WIND GUSTS OF 40 TO 45 KNOTS POSSIBLE ALONG THE COAST. LOW RISK FOR A FEW GUSTS UP TO 50 KNOTS ALONG THE COAST. WEDNESDAY AND THURSDAY...LOW TO MODERATE CONFIDENCE. PERIODS OF MAINLY MVFR TO VFR CONDITIONS IN SOME RAIN/SNOW SHOWERS. BRIEF TIMES OF IFR CONDITIONS ARE ALSO POSSIBLE...BUT VERY LOW CONFIDENCE IN TIMING. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE. *** NORTHEAST GALES INTO SUNDAY NIGHT *** TODAY...RAIN OVER CAPE COD AND NANTUCKET WATERS AT SUNRISE QUICKLY MOVES OFFSHORE. GUSTY NNE WINDS CONTINUE WITH GUSTS UP TO 45 KT POSSIBLE...STRONGEST WINDS CAPE COD AND NANTUCKET WATERS. ROUGH SEAS EASTERN MA WATERS. NNE WINDS WILL LIKELY GENERATE OCEAN EFFECT SNOW SHOWERS LATER IN THE DAY. TONIGHT...NNE GALES THRU THE EVENING AND THEN EASING SLOWLY TOWARD MONDAY MORNING. OCEAN-EFFECT SNOW SHOWERS WILL REDUCE VSBY. ROUGH SEAS EASTERN MA WATERS. MONDAY...HIGH CONFIDENCE. STRONG HIGH PRESSURE OVER THE CANADIAN MARITIMES WILL BE ENOUGH TO GENERATE NORTHEAST WIND GUSTS OF 20 TO 30 KNOTS. STRONGEST WINDS ACROSS THE SOUTHERN WATERS. SMALL CRAFT ADVISORY HEADLINES WILL BE NEEDED. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... ***HIGH IMPACT MARINE EVENT EXPECTED WITH 15 TO 20 FOOT SEAS AND AT LEAST 40 TO 45 KNOT WIND GUSTS ON TUESDAY*** MONDAY NIGHT ...HIGH CONFIDENCE. STRONG HIGH PRESSURE OVER THE CANADIAN MARITIMES WILL BE ENOUGH TO GENERATE EASTERLY WIND GUSTS OF 20 TO 30 KNOTS. STRONGEST WINDS ACROSS THE SOUTHERN WATERS. TUESDAY...MODERATE TO HIGH CONFIDENCE. INTENSIFYING LOW PRESSURE APPROACHES SOUTHERN NEW ENGLAND WITH STRONG HIGH PRESSURE ACROSS THE CANADIAN MARITIMES. HIGH CONFIDENCE IN NORTHEAST WIND GUSTS OF 40 TO 45 KNOTS AND GALE WARNINGS ARE A SLAM DUNK. THERE IS A LEAST A LOW PROBABILITY FOR A PERIOD OF STORM FORCE WINDS WITH THE POTENTIAL FOR WIND GUSTS TO 50 KNOTS. SEAS ARE EXPECTED TO BUILD TO BETWEEN 15 TO 20 FEET ACROSS THE EASTERN OPEN WATERS. HAVE ISSUED A COMBINATION OF GALE AND STORM WATCHES FOR THE COASTAL WATERS. WEDNESDAY AND THURSDAY...LOW CONFIDENCE. UNCERTAINTY ON LOCATION OF THE LOW PRESSURE SYSTEM...SO WIND DIRECTION AND SEAS ARE UNCERTAIN. REGARDLESS...AT LEAST SCA WIND GUSTS AND SEAS ARE EXPECTED. && .TIDES/COASTAL FLOODING... ASTRONOMICAL TIDES ARE FAIRLY HIGH DURING THE LATE MORNING. HOWEVER...IT WILL TAKE SOME TIME FOR SURGE TO BE GENERATED AS WINDS TURN NORTH TO NORTHEAST. AS A RESULT...THERE COULD BE MINOR SPLASHOVER AT THE MORE VULNERABLE COASTAL LOCATIONS. THE ASTRONOMICAL TIDE TONIGHT IS LOWER...SO NOT AS MUCH OF A CONCERN. THE BIGGEST CONCERN IS THE ASTRONOMICAL HIGH TIDE ALONG THE EASTERN MA COAST DURING THE MIDDAY TUE HIGH TIDE. TIMING OF STRONGEST WINDS/WAVE HEIGHTS REMAINS SOMEWHAT UNCERTAIN. GFS MIGHT BE A BIT FAST COMPARED TO THE ECMWF/GEFS ENSEMBLES. THE GFS WOULD HAVE WINDS/SEAS RAMPED UP BY TUE AFTERNOON...WHILE ECMWF SHOWS IT OCCURRING 3 TO 6 HOURS LATER. IF THE GFS VERIFIES...WE WOULD BE LOOKING AT THE POTENTIAL FOR A MODERATE COASTAL FLOOD EVENT ON EASTERN MA COAST. LEANING A BIT MORE TOWARDS THE SLOWER ECMWF...WHICH WOULD STILL BRING THE RISK FOR A MINOR COASTAL FLOOD EVENT WITH A 2+ FOOT SURGE POSSIBLE. EITHER WAY...DEFINITELY THIS RISK FOR AT LEAST SOME MINOR COASTAL FLOODING/BEACH EROSION SO SOMETHING TO WATCH. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR MAZ022>024. RI...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR RIZ008. MARINE...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ231>234-236. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ230. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ235-237. GALE WARNING UNTIL 1 AM EST MONDAY FOR ANZ250-251. GALE WARNING UNTIL 7 AM EST MONDAY FOR ANZ254-255. GALE WARNING UNTIL 6 AM EST MONDAY FOR ANZ256. && $$ SYNOPSIS...BELK/RLG NEAR TERM...BELK SHORT TERM...BELK LONG TERM...RLG AVIATION...BELK/RLG MARINE...BELK/RLG TIDES/COASTAL FLOODING...BELK/RLG
AREA FORECAST DISCUSSION
NWS TAUNTON MA
218 AM EST SUN DEC 7 2014 .SYNOPSIS... A LOW PRESSURE WILL TRACK SOUTH OF NEW ENGLAND TONIGHT...RESULTING IN PERIODS OF RAIN...HEAVY AT TIMES ACROSS CT/RI AND SOUTH OF THE PIKE IN MASSACHUSETTS. DRY BUT MUCH COLDER AND BLUSTERY WEATHER FOLLOWS SUNDAY....AND LINGERS INTO MONDAY. A STRONG COASTAL STORM WILL LIKELY IMPACT THE REGION WITH PERIODS OF HEAVY RAIN AND STRONG WINDS ALONG THE COAST TUESDAY...AND POSSIBLY A PERIOD OF ACCUMULATING WET SNOW ACROSS NORTHWEST AND NORTH CENTRAL MASSACHUSETTS. UNSETTLED WEATHER MAY LINGER WEDNESDAY INTO THURSDAY...BUT THIS WILL LIKELY BE MIXED WITH TIMES OF DRY WEATHER. DRY AND SEASONABLE WEATHER IS EXPECTED FOR THE START OF NEXT WEEKEND. && .NEAR TERM /THROUGH TODAY/... ANY EARLY MORNING PRECIP SHOULD BE CONFINED TO CAPE COD AND THE ISLANDS AND MOVING QUICKLY OFFSHORE AS A COLD FRONT MOVES ACROSS SOUTHERN NEW ENGLAND. AGAIN PRECIP COULD END AS A BRIEF PERIOD OF SNOW AND/OR SLEET. LATEST RUNS OF THE HRRR LOOK TO HAVE A GOOD TIMING FOR THE BACK EDGE...SO LEANED HEAVILY UPON THAT TIMING. LOW PROBABILITY OF SOME SLICK SPOTS EARLY THIS MORNING ALONG AND NORTHWEST OF I-95 IN MA AND RI AS TEMPERATURES FALL AT OR BELOW FREEZING AND COMBINE WITH ANY RESIDUAL MOISTURE ON THE ROADS. GOOD POST FRONTAL MIXING MAY DRY THINGS OUT FAIRLY QUICKLY. BEHIND THIS FRONT...DRY CONDITIONS BUT WINDY AND MUCH COLDER WITH NNE WINDS 15 TO 25 MPH GUSTING UP TO 35 MPH...EXCEPT UP TO 50 MPH ACROSS CAPE COD AND ISLANDS. CLEARING WILL BE BRIEF...AS NNE FLOW YIELDS LOTS OF OCEAN-EFFECT STRATOCUMULUS CLOUDS ACROSS EASTERN MA. AT LEAST PARTLY SUNNY ELSEWHERE. THE BIG QUESTION IS WILL THERE BE ENOUGH OF A TEMPERATURE DIFFERENTIAL. WITH WATER TEMPERATURES IN THE UPPER 40S...ONLY GETTING MAX DIFFERENTIALS ABOUT -5C TO -7C. THAT IS TYPICALLY NOT ENOUGH TO GENERATE SUFFICIENT OCEAN-INDUCED CAPE. THERE IS ALSO THE PROBLEM OF THE SIGNIFICANT SUBSIDENCE INVERSION BASED AROUND 950 MB WITH ABUNDANT DRY AIR ABOVE IT. THAT LEAVES ONLY A VERY SHALLOW LAYER FOR ANY SHOWERS TO DEVELOP. LEFT A CHANCE OF SNOW/SLEET SHOWERS IN THE FORECAST...BUT IT IS THE LOWEST CONFIDENCE PORTION OF THIS FORECAST. OTHERWISE...THERE SHOULD BE ENOUGH OF A PRESSURE GRADIENT BETWEEN THE DEPARTING LOW PRESSURE AND A STRONG HIGH PRESSURE OVER SOUTHEAST CANADA TO GENERATE STRONG NORTH TO NORTHEAST WINDS ACROSS CAPE COD AND THE ISLANDS. && .SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/... STRONG HIGH PRESSURE CONTINUES TO MOVE INTO THE MARITIMES AND NORTHERN NEW ENGLAND TONIGHT. EXPECTING COLD CONDITIONS ACROSS ALL OF SOUTHERN NEW ENGLAND....WITH GUSTY WINDS LINGERING ACROSS CAPE COD AND THE ISLANDS. WINDS DIMINISH SOME MONDAY. SREF AND HIGH RESOLUTION WRF CONTINUE TO HAVE HIGHER PRECIPITATION CHANCES THAN JUST ABOUT ALL OTHER GUIDANCE. THIS COULD BE A FUNCTION OF THE HIGHER RESOLUTION OF THE WRF MEMBERS. STILL SEEING THE SAME ISSUES WITH OCEAN-EFFECT SHOWERS...THAT BEING THE STRONG SUBSIDENCE INVERSION AND DEEP DRY AIR. MAINTAINED A CHANCE OF SHOWERS ACROSS EASTERN MA AND PORTIONS OF RI FOR NOW...AND WILL CONTINUE TO EVALUATE THIS POTENTIAL. AFTER A VERY COLD START MONDAY MORNING...WILL SEE AFTERNOON HIGH TEMPERATURES STAY BELOW NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGHLIGHTS... * STRONG NOREASTER LIKELY TUE W/HEAVY RAIN + STRONG COASTAL WINDS * ACCUM SNOW POSS TUE INTERIOR NORTHERN MA BEFORE CHANGE TO RAIN * UNSETTLED WEATHER MAY LINGER WED INTO THU - BUT NOT THE ENTIRE TIME * MAINLY DRY AND SEASONABLY BY NEXT FRI AND SAT DETAILS... MONDAY NIGHT... THE COLD ONSHORE FLOW SHOULD RESULT IN LIGHT OCEAN EFFECT SNOW SHOWERS ACROSS THE EASTERN MA COAST MON NIGHT. SHALLOW INVERSION SHOULD KEEP ANY SNOW AMOUNTS PROBABLY UNDER 1 INCH...BUT CAN/T RULE OUT SOME SLICK SPOTS ALONG THE COAST. PTYPE MAY GRADUALLY CHANGE TO LIGHT RAIN SHOWERS ALONG THE SOUTHEAST NEW ENGLAND COAST AS MILDER AIR BEGINS TO WORK IN OFF THE OCEAN. TUESDAY... THE MAIN EVENT APPEARS TO BE ON TUESDAY INTO TUESDAY EVENING. VERY STRONG NORTHERN STREAM ENERGY WILL DIVE SOUTHEASTWARD ACROSS THE GREAT LAKES AND CLOSE OFF OVER THE NORTHEAST...BECOMING NEGATIVELY TILTED. THIS WILL ALLOW A DISTANT LOW PRESSURE SYSTEM OFF THE MID ATLANTIC COAST TO GET PULLED BACK TO THE NORTHWEST AND APPROACH SOUTHERN NEW ENGLAND. AS THIS LOW PRESSURE SYSTEM INTENSIFIES A STRONG EASTERLY LOW LEVEL JET WILL DEVELOP...RESULTING IN PLENTY OF MOISTURE/VERY STRONG FORCING. GFS APPEARS IT MAY BE BIT FAST COMPARED TO SOME OF ITS ENSEMBLES/ECMWF MODEL...SO THINK BRUNT OF STORM WILL HOLD OFF UNTIL TUE INTO TUE EVENING. 1) ACCUMULATING SNOW POTENTIAL FOR NORTH CENTRAL/NORTHWEST MA: THE PROBLEM FOR THIS EVENT IS THAT THERE IS AN INITIAL WEAK LOW PRESSURE SYSTEM THAT MOVES WELL TO OUR NORTHWEST ACROSS THE GREAT LAKES. THIS ALLOW SOME WARMING ALOFT OUT AHEAD OF THE MAIN EVENT. THE LARGE HIGH PRESSURE SYSTEM SHIFTS EAST TOWARDS THE CANADIAN MARITIMES...NOT AN IDEAL POSITIONING FOR MUCH OF THE REGION TO KEEP COLD AIR IN PLACE. THEREFORE...MOST OF THE PRECIPITATION WILL BE IN THE FORM OF RAIN ON TUE. HOWEVER...DEPENDING ON THE EXACT TRACK WILL HAVE TO BE CAREFUL ACROSS NORTHWEST/NORTH CENTRAL MA. MID LEVEL CENTERS ARE CLOSING OFF AT THIS TIME. THERMAL PROFILES ARE CLOSE TO ISOTHERMAL AND VERY STRONG FORCING WILL MAKE IT A CLOSE CALL BETWEEN A HEAVY THUMP OF SNOW PERHAPS JUST A COLD RAIN. GIVEN THE EVENT IS STILL 72 HOURS OUT IN THE MODEL WORLD...A SLIGHT CHANGE IN POSITIONING CAN MAKE ALL THE DIFFERENCE. CERTAINLY SOMETHING THAT WILL NEED TO BE WATCHED BECAUSE THE POTENTIAL EXISTS FOR MAINLY RAIN OR 2 INCH PER HOUR SNOWFALL RATES. SO AS YOU CAN SEE THE STAKES ARE QUITE HIGH FOR A SMALL PORTION OF OUR REGION. 2) HEAVY RAIN AND URBAN FLOODING: VERY STRONG FORCING WITH STRONG EASTERLY LOW LEVEL JET WILL RESULT IN MUCH OF THE AREA RECEIVING HEAVY RAINFALL ON TUESDAY. EASTERLY LOW LEVEL JET IS PROGGED TO BE 3 TO 4 STANDARD DEVIATIONS ABOVE NORMAL...RESULTING IN VERY STRONG FORCING. MOST MODELS ARE IN AGREEMENT WITH 1.50 TO 3 INCHES OF RAIN ACROSS MUCH OF THE REGION. WHILE THIS SHOULD NOT CAUSE RIVER FLOODING...SOME URBAN/POOR DRAINAGE STREET FLOODING IS LIKELY. MUCH OF THIS HEAVY RAIN MAY FALL OVER A VERY SHORT TIME...WHICH WOULD INCREASE THE RISK FOR SOME STREET FLOODING. 3) STRONG WINDS: EASTERLY LOW LEVEL JET OF 50 TO 60 KNOTS WILL LIKELY RESULT IN AT LEAST WIND ADVISORY CRITERIA BEING MET ON TUESDAY ALONG THE EASTERN MA COAST/CAPE/ISLANDS. LOW PROBABILITY FOR HIGH WIND WATCH/WARNING CRITERIA BEING MET AS WELL...BUT EITHER WAY SOME WIND HEADLINES WILL LIKELY BE NEEDED. NORTHEAST WIND GUSTS OF 40 TO 55 MPH ARE A GOOD BET ALONG THE COAST. 4) COASTAL FLOODING: THE BIGGEST CONCERN IS THE ASTRONOMICAL HIGH TIDE ALONG THE EASTERN MA COAST DURING THE MIDDAY TUE HIGH TIDE. TIMING OF STRONGEST WINDS/WAVE HEIGHTS REMAINS SOMEWHAT UNCERTAIN. GFS MIGHT BE A BIT FAST COMPARED TO THE ECMWF/GEFS ENSEMBLES. THE GFS WOULD HAVE WINDS/SEAS RAMPED UP BY TUE AFTERNOON...WHILE ECMWF SHOWS IT OCCURRING 3 TO 6 HOURS LATER. IF THE GFS VERIFIES...WE WOULD BE LOOKING AT THE POTENTIAL FOR A MODERATE COASTAL FLOOD EVENT ON EASTERN MA COAST. LEANING A BIT MORE TOWARDS THE SLOWER ECMWF...WHICH WOULD STILL BRING THE RISK FOR A MINOR COASTAL FLOOD EVENT WITH A 2+ FOOT SURGE POSSIBLE. EITHER WAY...DEFINITELY THIS RISK FOR AT LEAST SOME MINOR COASTAL FLOODING/BEACH EROSION SO SOMETHING TO WATCH. WEDNESDAY AND THURSDAY... LOW CONFIDENCE FORECAST OVER THIS TIME. VERTICALLY STACKED LOW PRESSURE WILL MEANDER AROUND NEW ENGLAND...CUTOFF FROM THE MAIN UPPER LEVEL FLOW. THE GFS/GGEM SHOW THE CLOSED UPPER LEVEL LOW GENERALLY TO OUR NORTH OVER THIS TIME. IF THESE SOLUTIONS VERIFY...MUCH OF WED AND THU WOULD BE DRY OTHER THAN A FEW RAIN/SNOW SHOWERS AT TIMES. HOWEVER...THE ECMWF HAS THE 500 MB LOW TO OUR SOUTH FOR A TIME LATE WED INTO EARLY THU. IF THIS VERIFIES COULD PUT US IN THE TROWAL AND A PERIOD OF EVEN ACCUMULATING SNOW ACROSS PORTIONS OF SOUTHERN NEW ENGLAND. AGAIN...VERY LOW CONFIDENCE BUT SOMETHING WILL NEED TO WATCH. FRIDAY AND SATURDAY... UPPER LEVEL LOW FINALLY BEGINS TO LOSE ITS GRIP ON THE REGION PUSHING OFF TO THE NORTHEAST. THIS ALLOWS MAINLY DRY WEATHER WITH SEASONABLE TEMPS FRI INTO SAT. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. TODAY...VFR EXCEPT LINGERING IFR/MVFR OVER CAPE COD AND ISLANDS EARLY. NE WINDS GUSTING UP TO 45 KT OVER CAPE COD AND ISLANDS. IFR/MVFR RETURN TO EASTERN MA IN THE AFTERNOON AS SNOW SHOWERS OVER EASTERN MA WATERS COME ONSHORE. TONIGHT...VFR EXCEPT IFR/MVFR ACROSS EASTERN MA IN SCATTERED SNOW SHOWERS ALONG WITH NE WINDS G35 KT...HIGHEST CAPE COD AND ISLANDS. SOME MINOR ACCUMULATION POSSIBLE ACROSS PORTIONS OF EASTERN MA. MONDAY...MODERATE CONFIDENCE. MVFR CONDITIONS SPREAD INLAND FROM THE COAST AS THE DAY WEARS ON WITH ONSHORE FLOW. EVEN SOME IFR CIGS POSSIBLE ALONG THE COAST FOR A TIME IN A FEW RAIN/SNOW SHOWERS. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... TUESDAY...MODERATE CONFIDENCE. MVFR-IFR CONDITIONS EXPECTED IN MAINLY RAIN...WITH PERHAPS A PERIOD OF HEAVY WET SNOW ACROSS NORTHWEST MA/NORTH CENTRAL MA. NORTHEAST WIND GUSTS OF 40 TO 45 KNOTS POSSIBLE ALONG THE COAST. LOW RISK FOR A FEW GUSTS UP TO 50 KNOTS ALONG THE COAST. WEDNESDAY AND THURSDAY...LOW TO MODERATE CONFIDENCE. PERIODS OF MAINLY MVFR TO VFR CONDITIONS IN SOME RAIN/SNOW SHOWERS. BRIEF TIMES OF IFR CONDITIONS ARE ALSO POSSIBLE...BUT VERY LOW CONFIDENCE IN TIMING. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE. *** NORTHEAST GALES INTO SUNDAY NIGHT *** TODAY...RAIN OVER CAPE COD AND NANTUCKET WATERS AT SUNRISE QUICKLY MOVES OFFSHORE. GUSTY NNE WINDS CONTINUE WITH GUSTS UP TO 45 KT POSSIBLE...STRONGEST WINDS CAPE COD AND NANTUCKET WATERS. ROUGH SEAS EASTERN MA WATERS. NNE WINDS WILL LIKELY GENERATE OCEAN EFFECT SNOW SHOWERS LATER IN THE DAY. TONIGHT...NNE GALES THRU THE EVENING AND THEN EASING SLOWLY TOWARD MONDAY MORNING. OCEAN-EFFECT SNOW SHOWERS WILL REDUCE VSBY. ROUGH SEAS EASTERN MA WATERS. MONDAY...HIGH CONFIDENCE. STRONG HIGH PRESSURE OVER THE CANADIAN MARITIMES WILL BE ENOUGH TO GENERATE NORTHEAST WIND GUSTS OF 20 TO 30 KNOTS. STRONGEST WINDS ACROSS THE SOUTHERN WATERS. SMALL CRAFT ADVISORY HEADLINES WILL BE NEEDED. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... ***HIGH IMPACT MARINE EVENT EXPECTED WITH 15 TO 20 FOOT SEAS AND AT LEAST 45 KNOT WIND GUSTS ON TUESDAY*** TUESDAY...MODERATE TO HIGH CONFIDENCE. INTENSIFYING LOW PRESSURE APPROACHES SOUTHERN NEW ENGLAND WITH STRONG HIGH PRESSURE ACROSS THE CANADIAN MARITIMES. HIGH CONFIDENCE IN NORTHEAST WIND GUSTS OF 40 TO 45 KNOTS AND GALE WARNINGS ARE A SLAM DUNK. THERE IS A LEAST A LOW PROBABILITY FOR A PERIOD OF STORM FORCE WINDS WITH THE POTENTIAL FOR WIND GUSTS TO 50 KNOTS. SEAS ARE EXPECTED TO BUILD TO BETWEEN 15 TO 20 FEET ACROSS THE EASTERN OPEN WATERS. WILL ISSUE A MARINE WEATHER STATEMENT TO HIGHLIGHT THESE CONCERNS. WEDNESDAY AND THURSDAY...LOW CONFIDENCE. UNCERTAINTY ON LOCATION OF THE LOW PRESSURE SYSTEM...SO WIND DIRECTION AND SEAS ARE UNCERTAIN. REGARDLESS...AT LEAST SCA WIND GUSTS AND SEAS ARE EXPECTED. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR MAZ022>024. RI...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR RIZ008. MARINE...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ231>234-236. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ230. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ235-237. GALE WARNING UNTIL 1 AM EST MONDAY FOR ANZ250-251. GALE WARNING UNTIL 7 AM EST MONDAY FOR ANZ254-255. GALE WARNING UNTIL 6 AM EST MONDAY FOR ANZ256. && $$ SYNOPSIS...BELK/FRANK NEAR TERM...BELK SHORT TERM...BELK LONG TERM...FRANK AVIATION...BELK/FRANK MARINE...BELK/FRANK
AREA FORECAST DISCUSSION
NWS MIAMI FL
838 PM EST MON DEC 8 2014 .UPDATE... NO MAJOR CHANGES TO THE FORECAST THIS EVENING. SOME ADJUSTMENTS T POPS TO REFLECT CURRENT OBSERVATIONS AND MODEL TRENDS FOR TONIGHT. ALSO, THE SREF IS SHOWING THE BEST CHANCES OF FOG TO BE FURTHER SOUTH THAN ORIGINALLY FORECAST. IT IS ALSO SHOWING THAT IT IS POSSIBLE THE BROWARD/MIAMI-DADE METRO AREAS MAY ALSO HAVE SOME CHANCE OF SEEING FOG IN THE MORNING. BUT, HAVE KEPT IT OUT OF THOSE AREAS FOR NOW, WITH THE INTERIOR BEING THE MAIN AREA IMPACTED BY PATCHY FOG. HOWEVER, THE LATEST RUN OF THE HRRR IS ALSO SHOWING THE METRO AREAS BEING IMPACTED WITH FOG, INCLUDING THE PALM BEACH AREA. SO, THIS MAY NEED TO BE ADDED IN WITH THE NEXT UPDATE. && .PREV DISCUSSION... /ISSUED 659 PM EST MON DEC 8 2014/ AVIATION... VFR CONDITIONS WILL PERSIST THROUGH THE BULK OF THE PERIOD WITH LIGHT NW LOW-LEVEL FLOW CONTINUING. THERE IS SOME DISAGREEMENT BETWEEN GFS/NAM AND HRRR/RAP ON REGARD TO PATCHY FOG/LOW CIGS TONIGHT INTO TUESDAY MORNING ACROSS PORTIONS OF THE AREA ONCE AGAIN. WITH THE LOW CONFIDENCE INCLUDED VFR CONDITIONS WITH A FEW AND SCT LOW CLOUDS. PREV DISCUSSION... /ISSUED 345 PM EST MON DEC 8 2014/ DISCUSSION... THE MAIN SURFACE SYNOPTIC FEATURES ACROSS THE REGION INCLUDE A SURFACE LOW IN THE VICINITY OF BERMUDA WITH A TRAILING COLD FRONT ACROSS THE CENTRAL BAHAMAS AND THE FLORIDA STRAITS. IN ADDITION THERE IS A WEAK SURFACE TROUGH TO THE NORTHWEST OF THE FLORIDA PANHANDLE. AT THE MID TO UPPER LEVELS THERE IS A LARGE AMPLITUDE MID TO UPPER LEVEL TROUGH WEST OF THE GREAT LAKES EXTENDING SOUTHWARD TO THE NORTHERN GULF. THE MID TO UPPER LEVEL TROUGH IS FORECAST TO SHIFT EASTWARD INTO THE EASTERN GULF TONIGHT WITH A RE-ENFORCING SURFACE BOUNDARY MOVING INTO THE FLORIDA PENINSULA TONIGHT. THIS WILL MAINTAIN NORTHERLY WINDS ACROSS THE REGION TONIGHT INTO TUESDAY WITH ADDITIONAL COLD AIR ADVECTION. THE COMBINATION OF COOLER AIR AND LINGERING MOISTURE COULD RESULT IN FOG ACROSS SOUTH FLORIDA EARLY TUESDAY MORNING. THE MOST RECENT MODEL GUIDANCE ALSO SUGGESTS A CHANCE OF FOG EARLY TUESDAY AND IS INDICATED IN THE FORECAST. AS NOTED EARLIER...THE COMBINATION OF A PERSISTENT PRESSURE GRADIENT AND WELL ESTABLISHED NORTHEAST FETCH ACROSS THE WESTERN ATLANTIC EAST OF THE CAROLINAS IS FORECAST TO PRODUCE LONG PERIOD NORHTHEASTERLY SWELL THAT WILL CONTINUE TO ENTER THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY TODAY. THE LONG PERIOD SWELL WILL CONTINUE TO ENTER THE REGIONAL ATLANTIC WATERS TONIGHT INTO TUESDAY AND FORECAST TO CONTINUE THROUGH AT LEAST WEDNESDAY. THIS PROMPTED THE ISSUANCE OF A HIGH RISK OF RIP CURRENTS FOR THE ATLANTIC COAST BEACHES TODAY THROUGH WEDNESDAY EVENING. IN ADDITION...A HIGH SURF ADVISORY IS IN EFFECT FOR TUESDAY MORNING THROUGH WEDNESDAY MORNING FOR THE BEACHES OF PALM BEACH COUNTY WITH SURF HEIGHTS FORECAST TO BE NEAR 10 FEET BY EARLY TUESDAY MORNING. FOR THE FORECAST TUESDAY THROUGH FRIDAY...MAINLY DRY AND STABLE CONDITIONS AND NORTHERLY TO NORTHWESTERLY WINDS ARE FORECAST THROUGH THIS PERIOD WITH UNSEASONABLY COOLER TEMPERATURES PREVAILING. MARINE... AS MENTIONED ABOVE...LONG PERIOD NORHTHEASTERLY SWELL WILL CONTINUE TO ENTER THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY TODAY THEN CONTINUE TO ENTER THE ATLANTIC WATERS TONIGHT INTO TUESDAY AND FORECAST TO CONTINUE THROUGH AT LEAST WEDNESDAY. IN ADDITION NORTHWESTERLY WINDS IN THE 15 TO 20 KNOT RANGE ARE FORECAST TO BUILD INTO THE REGIONAL WATERS ON TUESDAY. WINDS ACROSS THE ALTANTIC WATERS COULD REACH THE 20-22 KNOT RANGE LATER ON TUESDAY. THE COMBINATION OF THE BUILDING SWELL AND WINDS TO ADVISORY LEVELS WILL RESULT IN HAZARDOUS SEAS ACROSS THE ATLANTIC WATERS WITH SMALL CRAFT ADVISORY IN EFFECT ALL ATLANTIC WATERS THIS EVENING THROUGH WEDNESDAY EVENING. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 60 72 50 65 / 10 10 0 0 FORT LAUDERDALE 62 73 53 67 / 10 10 0 0 MIAMI 62 73 52 67 / 10 10 0 0 NAPLES 59 70 50 65 / 10 10 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR FLZ168-172- 173. HIGH SURF ADVISORY FROM 7 AM TUESDAY TO 10 AM EST WEDNESDAY FOR FLZ168. AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR AMZ650-651-670- 671. HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR AMZ630. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1247 PM EST SUN DEC 7 2014 .SYNOPSIS... MOISTURE IS EXPECTED TO SPREAD BACK INTO THE REGION LATE TONIGHT AND MONDAY WITH WELL BELOW NORMAL TEMPERATURES AND CONSIDERABLE CLOUDINESS. THERE WILL BE A CHANCE OF LIGHT RAIN BY MONDAY AFTERNOON ESPECIALLY EAST MIDLANDS AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. HIGH PRESSURE WILL BUILD INTO THE AREA MID WEEK WITH TEMPERATURES SLIGHTLY BELOW NORMAL. && .NEAR TERM /THROUGH TONIGHT/... UPPER TROUGH CONTINUES TO MOVE EAST OFFSHORE THE MID ATLANTIC COAST...WHILE SURFACE HIGH PRESSURE BUILDS DOWN THE EAST COAST. SATELLITE INDICATES AREA OF CLOUDINESS SHIFTING SOUTH...AND APPEARS WILL SHIFT SOUTH OF OUR FORECAST AREA (FA) LATER THIS AFTERNOON. SATELLITE ALSO SUGGESTS UPPER CLOUDINESS WILL MOVE INTO OUR REGION TONIGHT AHEAD OF AN APPROACHING UPPER TROUGH...WHICH IS ALSO EXPECTED TO LEAD TO WEAK ISENTROPIC LIFT LATE TONIGHT...CAUSING ADDITIONAL LOWER TO MID LEVEL CLOUDINESS TO SPREAD BACK NORTH INTO OUR FA. MODEL CONSENSUS HOLDS OF ON ANY MEASURABLE PRECIPITATION FOR OUR FA THROUGH TONIGHT. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... UPPER TROUGH MOVING THROUGH THE GULF COAST AND SOUTHEASTERN STATES MONDAY WILL RESULTING SOUTHWEST FLOW ALOFT OVER CAROLINAS. SURFACE RIDGE EXTENDING FROM THE CANADIAN MARITIMES SOUTHWEST ACROSS THE MID ATLANTIC TO THE CAROLINAS. WEAK SURFACE LOW WILL BE DEVELOPING WELL EAST OF THE CAROLINA COAST BY MONDAY AFTERNOON. MODELS CONTINUE TO INDICATE COLD AIR DAMMING IN THE CAROLINAS...ALTHOUGH WEAK DUE TO LACK OF SIGNIFICANT ISENTROPIC LIFT AND SHALLOW MOISTURE. EXPECT CONSIDERABLE CLOUDINESS PROBABLY OVERCAST BY LATE MORNING WITH WEAK SOUTHEAST 850MB MOISTURE ADVECTION OFF ATLANTIC. AS COASTAL LOW MOVES A LITTLE CLOSER TO THE NORTH CAROLINA COAST MONDAY AFTERNOON AND EVENING IN RESPONSE TO APPROACHING MID LEVEL SHORT WAVE TROUGH...WEAK LOW LEVEL CONVERGENCE NOTED IN THE NORTH AND EAST AND ENOUGH LIFT FOR SOME PATCHY LIGHT RAIN/DRIZZLE. SO RAISED POPS ESPECIALLY NORTH AND EAST MIDLANDS/PEE DEE THROUGH EVENING...BUT QPF LIKELY QUITE LOW. TEMPERATURES...PREFER SREF MEAN WHICH IS BELOW MOS AVERAGE/NEAR CURRENT FORECAST AND REASONABLE BASED ON LOCAL WEDGE SCHEME. LINGERING CLOUDINESS MONDAY NIGHT MAY RESULT IN OVERNIGHT TEMPERATURES ABOVE MOS MEAN. WEDGE ERODING EARLY TUESDAY...SOME MORNING CLOUDS BUT EXPECT CLEARING THROUGH DAY WITH DOWNSLOPE...CLOUDINESS LIKELY TO REMAIN MAINLY NORTH AND WEST. GUIDANCE TEMPERATURES IN THE MID 50S ON TRACK. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... MODELS SHOW THE UPPER LOW CLOSING OFF AND BECOMING STACKED WITH THE SURFACE LOW OVER THE NORTHEASTERN STATES ON WEDNESDAY. SURFACE HIGH PRESSURE OVER THE CENTRAL CONUS WILL RIDGE INTO THE SOUTHEASTERN STATES. THIS PATTERN WILL PROMOTE WESTERLY/NORTHWESTERLY FLOW ACROSS THE FORECAST AREA. SURFACE HIGH PRESSURE WILL CONTINUE TO DOMINATE THE PATTERN WEDNESDAY THROUGH THE END OF THE LONG TERM PERIOD. STRONG NOCTURNAL COOLING WITH THE RIDGE NEAR THE AREA SHOULD RESULT IN COLD LOW TEMPERATURES IN THE UPPER 20S TO LOWER 30S WEDNESDAY THROUGH SUNDAY. MAX TEMPS ARE FORECAST BELOW CLIMATOLOGY IN THE 50S EARLY IN THE PERIOD WITH SLIGHT WARMING TREND INTO THE WEEKEND. && .AVIATION /17Z SUNDAY THROUGH THURSDAY/... CLOUDINESS...WITH MVFR CIGS...PUSHING SOUTH. TEMPO PERIODS OF MVFR CIGS IN THE NEAR TERM AT OGB...OTHERWISE VFR CONDITIONS EXPECTED THROUGH THIS EVENING. BREEZY NE WINDS INDICATING TREND TOWARDS SLIGHTLY DECREASING SPEEDS. SURFACE HIGH PRESSURE RIDGE WILL REMAIN ANCHORED ALONG THE EAST COAST THROUGH MONDAY. MODELS INDICATING PREMISE FOR INCREASING CLOUDINESS TO REENTER THE FORECAST AREA FROM THE SOUTH AND EAST LATE TONIGHT DUE TO WEAK ISENTROPIC LIFT AHEAD OF AN APPROACHING UPPER TROUGH...AND PERSIST THROUGH MUCH OF MONDAY. SOME MODEL DISCREPANCY ON CEILING HEIGHTS...CHOSE TO LEAN TOWARDS RAP MODEL PROJECTION OF MVFR CIGS...WHICH SEEMS PLAUSIBLE AT THIS TIME GIVEN THE SITUATION. RAIN CHANCES APPEAR TOO LOW TO INCLUDE IN THE TAFS AT THIS TIME. EXTENDED AVIATION OUTLOOK...MVFR RESTRICTIONS EXPECTED TO PERSIST THROUGH TUESDAY MORNING. OTHERWISE...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED LATE TUESDAY THROUGH THURSDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR SCZ030. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
844 PM CST MON DEC 8 2014 .UPDATE... 843 PM CST FOR EVENING UPDATE... UPDATED FORECAST TO REMOVE MUCH OF THE FOG AS VISIBILITY HAS IMPROVED MARKEDLY FROM EARLIER. ALSO ADJUSTED POP/WEATHER FOR LIGHT RAIN/SNOW COMBO CHANGING TO LIGHT SNOW PRIOR TO ENDING AFTER MIDNIGHT. SURFACE LOW PRESSURE WAS DRIFTING SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION THIS EVENING...WITH OCCLUDED COLD FRONT NOW PUSHING EAST ACROSS THE LAKE AND NORTHWEST INDIANA AS OF 02Z/8 PM CST. INTRUSION OF SOMEWHAT DRIER LOW LEVEL AIR HAS HELPED ERODE MUCH OF THE FOG AND LOWEST CLOUD BASES BEHIND THE FRONT...THUS HAVE REMOVED FOG FROM FORECAST EXCEPT FOR NEXT FEW HOURS OVER THE LAKE. ALOFT...ROBUST MID-LEVEL SHORT WAVE CIRCULATION WAS NEARLY OVERHEAD PER CURRENT WATER VAPOR IMAGERY AND 00Z RAOB ANALYSIS...AND IS NI THE PROCESS OF FORMING A CLOSED MID-LEVEL LOW CENTER WHICH WILL CONTINUE TO SLIDE OFF TO THE SOUTHEAST OF THE AREA OVERNIGHT. REGIONAL RADAR MOSAIC DEPICTS LIGHT PRECIPITATION ASSOCIATED WITH THIS FEATURE MAINLY ALONG ITS NORTHERN/EASTERN FLANKS...GENERALLY THE NORTHEAST HALF OR SO OF THE WFO LOT CWA. 00Z SOUNDINGS FROM DVN AND ILX SHOW MOISTURE GENERALLY BELOW 800-700 MB AND WITH CLOUD BEARING LAYER MIN TEMPS LESS THAN -10 C...RESULTING IN MAINLY DRIZZLE AND LIGHT RAIN WITH LACK OF ICE NUCLEATION. DEEPER MOISTURE FARTHER NORTH (GRB SOUNDING) WAS ASSOCIATED WITH BETTER PRECIPITATION ELEMENTS CLOSER TO THE MID-LEVEL CIRCULATION ACROSS EAST/SOUTHEAST WI WAS RESULTING IN WET SNOW. THIS DEEPER MOISTURE WITH THE MID-LEVEL WAVE AND A SLOW COOLING OF THE COLUMN IN THE WAKE OF THE COLD FRONT WILL LIKELY ALLOW FOR PRECIP TO MIX/CHANGE TO A LITTLE WET SNOW WHERE IT FALLS A LITTLE STEADIER...ESPECIALLY ACROSS FAR NORTHEAST IL THROUGH A LITTLE PAST MIDNIGHT AND INTO NORTHWEST INDIANA THROUGH EARLY TUESDAY MORNING. LOW SNOW TO LIQUID RATIOS AND LIGHT NATURE OF PRECIP SHOULD PRECLUDE ANY SIGNIFICANT ACCUMULATIONS OTHER THAN A FEW SLUSHY TENTHS PERHAPS IN ISOLATED AREAS BEFORE PRECIPITATION ENDS. RATZER && .SHORT TERM... 317 PM CST THROUGH WEDNESDAY... LIGHT RAIN OR DRIZZLE AND SOME PATCHY LIGHT SNOW ALL ARE LIKELY TO MAKE AN APPEARANCE THIS EVENING...ALONG WITH AREAS OF FOG. WATER VAPOR SATELLITE IMAGE SHOWS TWO UPPER CIRCULATIONS THAT WILL CROSS THE AREA...AND MODEL VORTICITY FIELDS ALOFT AND RH FIELDS AT LOWER LEVELS ALL SUPPORT THE IDEA OF PATCHY AREAS OF PRECIPITATION. AS OF LATE AFTERNOON MOST AREAS ARE IN THE MIDDLE TO UPPER 30S...AND PRECIP CHANCES SHOULD DIMINISH AS COLDER AIR APPROACHES...SO LITTLE IF ANY FROZEN PRECIPITATION WOULD BE EXPECTED TO ACCUMULATE. BY MORNING THE AXIS OF THE UPPER LONGWAVE IS WELL TO OUR EAST...AND UPPER SHORTWAVE ENERGY BEGINS TO EXIT THE AREA AS WELL. ONLY AT LOW LEVELS DO RH FIELDS SUGGEST CONTINUED SATURATION...SO WILL TREND POPS DOWNWARD TO BELOW MENTIONABLE LEVELS BY DAYBREAK EXCEPT DOWNWIND FROM THE LAKE IN NORTHWEST INDIANA AT THE END OF A NORTHWEST FETCH. EVEN THAT AREA APPEARS TO DRY OUT BY LATE TOMORROW AS WINDS CONTINUE VEERING NORTHEASTERLY AND LOW LEVELS DRY CONSIDERABLY. CLOUDINESS PERSISTS SOUTH OF THE LAKE LATE TOMORROW INTO TOMORROW NIGHT...BUT AREAS WEST CLEAR OUT A BIT. THIS ACCOUNTS FOR A FEW DEGREE TEMPERATURE DIFFERENCE IN TUESDAY NIGHT LOWS BETWEEN MORE CLEAR AND MORE OVERCAST AREAS. WEDNESDAY CONTINUES COOL...BUT NOT UNSEASONABLY SO...WITH GRADUALLY CLEARING SKIES. LENNING && .LONG TERM... 317 PM CST WEDNESDAY NIGHT THROUGH TUESDAY... THE REMAINDER OF THE WEEK AND ESPECIALLY THE WEEKEND DO NOT LOOK TOO BAD AT ALL FOR MID DECEMBER. COMPARED TO LAST MONTH...THE STRETCH OF DAYS STARTING ON FRIDAY THE 12TH LOOKS TO BE FROM 10 TO 20 DEGREES WARMER THAN THE SAME PERIOD FROM LAST MONTH. SO THE MIDDLE PORTIONS OF NOVEMBER AND DECEMBER APPEAR TO BE SWAPPED THIS YEAR. MODELS ARE IN REASONABLE THOUGH NOT PERFECT AGREEMENT THAT THE LARGE UPPER TROUGH NOW OVERHEAD WILL MOVE INTO THE EASTERN CONUS AND ALLOW A BROAD RIDGE FROM THE SFC TO UPPER LEVELS TAKE ITS PLACE. THIS RIDGING WITH ITS DRY AND MILD WEATHER APPEARS TO PERSIST AT LEAST INTO THE MIDDLE PART OF THE WEEKEND WHILE SLOWLY DRIFTING EAST. BY EARLY SUNDAY MODELS START TO SUGGEST A RETURN OF BETTER MOISTURE AHEAD OF AN APPROACHING FRONTAL ZONE ACROSS THE PLAINS AND WEST OF THE RIDGE. CONFIDENCE ON THE TIMING OF THIS MOIST SOUTHERLY FLOW INTO THE LOCAL AREA IS LOW...SO HAVE ELECTED TO INCLUDE INCREASED POPS BY SUNDAY AND MONDAY BUT ALL IN THE FORM OF LIGHT RAIN. LENNING && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * IFR CIG/VIS CONDITIONS THIS EVENING...WITH ANY LIFR EXPECTED TO IMPROVE BY 02-03Z. VSBYS BELOW 5 SM AT TIMES THROUGH THE EVENING IN DRIZZLE/LIGHT RAIN...POSSIBLY SOME WET LIGHT SNOW AT TIMES LATE. PRECIP SHOULD DIMINISH AFTER MIDNIGHT ALLOWING VFR VSBYS AND IMPROVEMENT TO SOLID MVFR CIGS BY TUESDAY MORNING. * MVFR CIGS LIKELY THROUGH MUCH OF TUESDAY. * WEST WINDS SHIFTING WEST-NORTHWEST THIS EVENING WITH GUSTS 15-20 KT. WINDS BECOME NORTHWEST OVERNIGHT AND NORTH-NORTHWEST TUESDAY. RATZER //DISCUSSION...UPDATED 00Z... LOW PRESSURE WAS MOVING SOUTHEAST ACROSS THE UPPER PENINSULA OF MICHIGAN EARLY THIS EVENING...WITH A TRAILING COLD FRONT PUSHING STEADILY EAST ACROSS NORTH CENTRAL IL. FRONT HAS MOVED THROUGH KRFD IN THE PAST 1-2 HOURS...AND WILL MOVE THROUGH CHICAGO TERMINALS THROUGH EARLY AND MID-EVENING. WINDS WILL SHIFT NORTHWEST BEHIND THE FRONT TONIGHT...AND MORE NORTHERLY TUESDAY AHEAD OF HIGH PRESSURE BUILDING ACROSS THE UPPER MIDWEST. INITIALLY AHEAD OF THE COLD FRONT...MANY LOCATIONS HAVE EXPERIENCED LIFR/IFR CONDITIONS WITH DRIZZLE AND FOG THIS AFTERNOON. CIGS/VIS IMPROVING QUICKLY TO MORE SOLID HIGHER END IFR BEHIND THE FRONT...AS WINDS SHIFT WEST-NORTHWEST AND BEGIN TO PULL DRIER AIR INTO THE REGION. A MID-LEVEL DISTURBANCE DEVELOPING OVERHEAD THIS EVENING WAS HELPING TO PRODUCE THE LIGHT PRECIPITATION...WHICH WILL LIKELY CONTINUE TO AFFECT THE TERMINALS AT LEAST AT TIMES THROUGH PERHAPS 2-3 AM. THIS PRECIP WHICH IS LARGELY IN THE FORM OF DRIZZLE/LIGHT RAIN...MAY AT TIMES CHANGE TO INTERMITTENT LIGHT SNOW WHERE POCKETS OF DEEPER MOISTURE ALLOW BETTER ICE CRYSTAL DEVELOPMENT...AND THIS LIGHT PRECIP MAY AT TIMES BRING CIGS/VIS BACK INTO LOWER-END IFR. THE DEVELOPING MID-LEVEL DISTURBANCE WILL MOVE OFF TO THE SOUTHEAST OF THE AREA ENDING THE LIGHT PRECIP THREAT BY TUESDAY MORNING. MODEL GUIDANCE DIFFERS A BIT ON CEILING HEIGHTS TUESDAY...BUT EXPECT BASES TO LIFT TO AT LEAST LOW-END MVFR HEIGHTS WITH THE END OF PRECIP BY MORNING. EXTENSIVE AREA OF 1000-2000 FT CIGS EXISTS UPSTREAM ACROSS THE UPPER MIDWEST HOWEVER...SO SUSPECT MVFR CIGS WILL LINGER THROUGH MUCH OF TUESDAY. AS MENTIONED ABOVE...WINDS SHIFT FROM WEST TO NORTHWEST THIS EVENING WITH COLD FRONTAL PASSAGE. INTRUSION OF COOLER AIR AND RESULTING MIXING/DEEPENING OF BOUNDARY LAYER SHOULD SUPPORT GUSTS IN THE 15-20 KT RANGE. WINDS BECOME MORE NORTHERLY BY TUESDAY AFTERNOON WITH GUSTS NEAR 20 KT EVENTUALLY DECREASING A BIT LATE IN THE DAY. RATZER //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH IN WIND TRENDS. HIGH IN ANY LINGERING LIFR IMPROVING SHORTLY. * MEDIUM-HIGH IN IMPROVING CIG TRENDS TONIGHT...MEDIUM-LOW IN CIG/VIS DETAILS IN ANY LIGHT PRECIP. * MEDIUM IN MVFR CIGS THROUGH TUESDAY. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY...MVFR CIGS POSSIBLE EARLY...THEN VFR. NORTH WINDS. THURSDAY...VFR. WEST WINDS. FRIDAY...MAINLY VFR. MVFR CIGS POSSIBLE AT NIGHT. SOUTHWEST WINDS. SATURDAY...MVFR CIGS POSSIBLE. SOUTH WINDS. SUNDAY...MVFR CIGS POSSIBLE. SLGT CHANCE OF RAIN. SOUTH WINDS. RATZER && .MARINE... 227 PM CST LOW PRESSURE IS OVER NORTHERN WISCONSIN AND IT WILL WEAKEN AS IT MOVES ACROSS THE LAKE TONIGHT. WINDS TURN NORTHWEST BEHIND THE LOWS COLD FRONT AND THEN THEY TURN NORTH AS HIGH PRESSURE BUILDS OVER MINNESOTA. THE GRADIENT TIGHTENS BETWEEN THE HIGH AND LOW WITH 30 KT NORTH WINDS EXPECTED ACROSS THE LAKE TOMORROW. WINDS AND WAVES WILL INCREASE IN THE NEARSHORE WATERS SO HOISTED A SMALL CRAFT ADVISORY BEGINNING EARLY TUESDAY MORNING. WINDS DIMINISH TUESDAY NIGHT AS THE HIGH APPROACHES BUT LARGE WAVES WILL LINGER IN THE NSH ZONES. HAVE MEDIUM CONFIDENCE IN HOW LONG THE HAZARDOUS WAVES WILL LINGER...BUT HAVE THE SMALL CRAFT ADVISORY GOING INTO WEDNESDAY NIGHT. NORTH WINDS BECOME NORTHWEST AS THE HIGH MOVES DOWN THE MISSISSIPPI VALLEY WEDNESDAY NIGHT AND CONTINUE TO BACK TO SOUTHWEST BY FRIDAY AFTERNOON. THE HIGH FINALLY SHIFTS EAST OVER THE OHIO VALLEY SATURDAY WITH THE NEXT LOW FORMING OVER THE PLAINS SATURDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...6 AM TUESDAY TO 9 PM WEDNESDAY. SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 3 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 832 PM CST Mon Dec 8 2014 .UPDATE... ISSUED AT 825 PM CST MON DEC 8 2014 Cold front has swept east of the state early this evening along with most of the light rain and drizzle. Low level flow has now shifted into the northwest and as a result, the cloud band that was shifting out of far west central Illinois this evening has been replaced by another band of clouds that was tracking southeast out of Iowa this afternoon and will be with us well into the morning hours of Tuesday. Not much in the way of precip over Iowa early this evening with the only snow and rain reports well to our north over far southern Wisconsin and northern IL. Most of the short term models suggest that light precip will remain to our north tonight. Current forecast has conditions well in hand for this evening and the overnight hours. Other than some minor wording adjustments in the overnight portion of the forecast, no other changes needed to the current ZFP. Will have the update out by 900 pm. && .SHORT TERM...(Tonight) ISSUED AT 248 PM CST MON DEC 8 2014 Cold front is pushing across central Illinois early this afternoon, located just west of Peoria and Springfield as of 2 pm. Extensive low cloud deck has been prevailing over the forecast area, with some localized dense fog along and north of the I-74 corridor. Surface observations showing visibilities and ceilings lifting behind the front, and the back edge of the cloudiness covered about the eastern third of Missouri. Well defined upper circulation evident on water vapor imagery over northeast Iowa, and this is producing some light rain and snow upstream from us. Main question for this part of the forecast is how much clearing will manage to take place. Lower clouds extend all the way back into southern North Dakota. RAP model guidance and current trajectories would suggest some clearing may take place over the far southwest parts of the forecast area for a short period, but a secondary surge of clouds is expected as the broad upper trough surrounding the aforementioned circulation swings through the Midwest this evening. Have kept the sky forecast on the pessimistic side and kept cloudy skies in the grids for tonight. Much of the associated precipitation should be just to our north, but will include some slight chance PoP`s for the northeast CWA for this evening. && .LONG TERM...(Tuesday through Monday) ISSUED AT 248 PM CST MON DEC 8 2014 As the low pressure area weakens and gets absorbed into an east coast system, a high pressure ridges will build into the area. This ridge will dominate the weather over the area through Wednesday and beyond. Some concern with lower level moisture remaining trapped under the ridge Tue through Wed, so have increased cloud cover to go mostly cloudy through Wed. As the center of the high pressure drops south into the southern Miss river valley, the ridge will remain over the area with dry weather through Thursday, the rest of the week and into the weekend. The area will also remain dominated by mid level cyclonic flow through the end of the week. Then mid level ridging, that was building in the plains, will begin to dominate the region for the weekend. Late in the weekend, the ridging will begin to push east and this will allow a frontal system to move into the area and bring rain to the region for Sun night and Monday. With high pressure dropping into the area and cyclonic flow, temps will remain cool for the next couple of days. But then as the high pressure settles south and mid level ridging builds, temps will begin to warm again. By the weekend, temps will warm to above normal, with 50s expected Sat and Sun. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 5050 PM CST MON DEC 8 2014 IFR cigs associated with the cold front will spread across most of the forecast area thru 02z associated with drizzle or light rain. Once that moves through, we expect cigs to become MVFR over most of the area with even a few breaks possible during the overnight hours. However, at this time, any breaks in the cloud cover will be short lived as the deep cyclonic flow aloft will bring about more low level moisture and cloud cover from the north for Tuesday. Outside the band of IFR cigs and rain, look for cigs to range from 1200-2500 feet after 03z and last into a good portion of Tuesday. Surface winds will become northwest across the entire area tonight with speeds averaging from 10 to 15 kts with a few gusts up to 20 kts at times this evening. Winds on Tuesday will be from the northwest to north winds are expected on Tuesday at 8 to 13 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Smith SHORT TERM...Geelhart LONG TERM...Auten AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
601 PM CST MON DEC 8 2014 .SHORT TERM... 317 PM CST THROUGH WEDNESDAY... LIGHT RAIN OR DRIZZLE AND SOME PATCHY LIGHT SNOW ALL ARE LIKELY TO MAKE AN APPEARANCE THIS EVENING...ALONG WITH AREAS OF FOG. WATER VAPOR SATELLITE IMAGE SHOWS TWO UPPER CIRCULATIONS THAT WILL CROSS THE AREA...AND MODEL VORTICITY FIELDS ALOFT AND RH FIELDS AT LOWER LEVELS ALL SUPPORT THE IDEA OF PATCHY AREAS OF PRECIPITATION. AS OF LATE AFTERNOON MOST AREAS ARE IN THE MIDDLE TO UPPER 30S...AND PRECIP CHANCES SHOULD DIMINISH AS COLDER AIR APPROACHES...SO LITTLE IF ANY FROZEN PRECIPITATION WOULD BE EXPECTED TO ACCUMULATE. BY MORNING THE AXIS OF THE UPPER LONGWAVE IS WELL TO OUR EAST...AND UPPER SHORTWAVE ENERGY BEGINS TO EXIT THE AREA AS WELL. ONLY AT LOW LEVELS DO RH FIELDS SUGGEST CONTINUED SATURATION...SO WILL TREND POPS DOWNWARD TO BELOW MENTIONABLE LEVELS BY DAYBREAK EXCEPT DOWNWIND FROM THE LAKE IN NORTHWEST INDIANA AT THE END OF A NORTHWEST FETCH. EVEN THAT AREA APPEARS TO DRY OUT BY LATE TOMORROW AS WINDS CONTINUE VEERING NORTHEASTERLY AND LOW LEVELS DRY CONSIDERABLY. CLOUDINESS PERSISTS SOUTH OF THE LAKE LATE TOMORROW INTO TOMORROW NIGHT...BUT AREAS WEST CLEAR OUT A BIT. THIS ACCOUNTS FOR A FEW DEGREE TEMPERATURE DIFFERENCE IN TUESDAY NIGHT LOWS BETWEEN MORE CLEAR AND MORE OVERCAST AREAS. WEDNESDAY CONTINUES COOL...BUT NOT UNSEASONABLY SO...WITH GRADUALLY CLEARING SKIES. LENNING && .LONG TERM... 317 PM CST WEDNESDAY NIGHT THROUGH TUESDAY... THE REMAINDER OF THE WEEK AND ESPECIALLY THE WEEKEND DO NOT LOOK TOO BAD AT ALL FOR MID DECEMBER. COMPARED TO LAST MONTH...THE STRETCH OF DAYS STARTING ON FRIDAY THE 12TH LOOKS TO BE FROM 10 TO 20 DEGREES WARMER THAN THE SAME PERIOD FROM LAST MONTH. SO THE MIDDLE PORTIONS OF NOVEMBER AND DECEMBER APPEAR TO BE SWAPPED THIS YEAR. MODELS ARE IN REASONABLE THOUGH NOT PERFECT AGREEMENT THAT THE LARGE UPPER TROUGH NOW OVERHEAD WILL MOVE INTO THE EASTERN CONUS AND ALLOW A BROAD RIDGE FROM THE SFC TO UPPER LEVELS TAKE ITS PLACE. THIS RIDGING WITH ITS DRY AND MILD WEATHER APPEARS TO PERSIST AT LEAST INTO THE MIDDLE PART OF THE WEEKEND WHILE SLOWLY DRIFTING EAST. BY EARLY SUNDAY MODELS START TO SUGGEST A RETURN OF BETTER MOISTURE AHEAD OF AN APPROACHING FRONTAL ZONE ACROSS THE PLAINS AND WEST OF THE RIDGE. CONFIDENCE ON THE TIMING OF THIS MOIST SOUTHERLY FLOW INTO THE LOCAL AREA IS LOW...SO HAVE ELECTED TO INCLUDE INCREASED POPS BY SUNDAY AND MONDAY BUT ALL IN THE FORM OF LIGHT RAIN. LENNING && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * IFR CIG/VIS CONDITIONS THIS EVENING...WITH ANY LIFR EXPECTED TO IMPROVE BY 02-03Z. VSBYS BELOW 5 SM AT TIMES THROUGH THE EVENING IN DRIZZLE/LIGHT RAIN...POSSIBLY SOME WET LIGHT SNOW AT TIMES LATE. PRECIP SHOULD DIMINISH AFTER MIDNIGHT ALLOWING VFR VSBYS AND IMPROVEMENT TO SOLID MVFR CIGS BY TUESDAY MORNING. * MVFR CIGS LIKELY THROUGH MUCH OF TUESDAY. * WEST WINDS SHIFTING WEST-NORTHWEST THIS EVENING WITH GUSTS 15-20 KT. WINDS BECOME NORTHWEST OVERNIGHT AND NORTH-NORTHWEST TUESDAY. RATZER //DISCUSSION...UPDATED 00Z... LOW PRESSURE WAS MOVING SOUTHEAST ACROSS THE UPPER PENINSULA OF MICHIGAN EARLY THIS EVENING...WITH A TRAILING COLD FRONT PUSHING STEADILY EAST ACROSS NORTH CENTRAL IL. FRONT HAS MOVED THROUGH KRFD IN THE PAST 1-2 HOURS...AND WILL MOVE THROUGH CHICAGO TERMINALS THROUGH EARLY AND MID-EVENING. WINDS WILL SHIFT NORTHWEST BEHIND THE FRONT TONIGHT...AND MORE NORTHERLY TUESDAY AHEAD OF HIGH PRESSURE BUILDING ACROSS THE UPPER MIDWEST. INITIALLY AHEAD OF THE COLD FRONT...MANY LOCATIONS HAVE EXPERIENCED LIFR/IFR CONDITIONS WITH DRIZZLE AND FOG THIS AFTERNOON. CIGS/VIS IMPROVING QUICKLY TO MORE SOLID HIGHER END IFR BEHIND THE FRONT...AS WINDS SHIFT WEST-NORTHWEST AND BEGIN TO PULL DRIER AIR INTO THE REGION. A MID-LEVEL DISTURBANCE DEVELOPING OVERHEAD THIS EVENING WAS HELPING TO PRODUCE THE LIGHT PRECIPITATION...WHICH WILL LIKELY CONTINUE TO AFFECT THE TERMINALS AT LEAST AT TIMES THROUGH PERHAPS 2-3 AM. THIS PRECIP WHICH IS LARGELY IN THE FORM OF DRIZZLE/LIGHT RAIN...MAY AT TIMES CHANGE TO INTERMITTENT LIGHT SNOW WHERE POCKETS OF DEEPER MOISTURE ALLOW BETTER ICE CRYSTAL DEVELOPMENT...AND THIS LIGHT PRECIP MAY AT TIMES BRING CIGS/VIS BACK INTO LOWER-END IFR. THE DEVELOPING MID-LEVEL DISTURBANCE WILL MOVE OFF TO THE SOUTHEAST OF THE AREA ENDING THE LIGHT PRECIP THREAT BY TUESDAY MORNING. MODEL GUIDANCE DIFFERS A BIT ON CEILING HEIGHTS TUESDAY...BUT EXPECT BASES TO LIFT TO AT LEAST LOW-END MVFR HEIGHTS WITH THE END OF PRECIP BY MORNING. EXTENSIVE AREA OF 1000-2000 FT CIGS EXISTS UPSTREAM ACROSS THE UPPER MIDWEST HOWEVER...SO SUSPECT MVFR CIGS WILL LINGER THROUGH MUCH OF TUESDAY. AS MENTIONED ABOVE...WINDS SHIFT FROM WEST TO NORTHWEST THIS EVENING WITH COLD FRONTAL PASSAGE. INTRUSION OF COOLER AIR AND RESULTING MIXING/DEEPENING OF BOUNDARY LAYER SHOULD SUPPORT GUSTS IN THE 15-20 KT RANGE. WINDS BECOME MORE NORTHERLY BY TUESDAY AFTERNOON WITH GUSTS NEAR 20 KT EVENTUALLY DECREASING A BIT LATE IN THE DAY. RATZER //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH IN WIND TRENDS. HIGH IN ANY LINGERING LIFR IMPROVING SHORTLY. * MEDIUM-HIGH IN IMPROVING CIG TRENDS TONIGHT...MEDIUM-LOW IN CIG/VIS DETAILS IN ANY LIGHT PRECIP. * MEDIUM IN MVFR CIGS THROUGH TUESDAY. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY...MVFR CIGS POSSIBLE EARLY...THEN VFR. NORTH WINDS. THURSDAY...VFR. WEST WINDS. FRIDAY...MAINLY VFR. MVFR CIGS POSSIBLE AT NIGHT. SOUTHWEST WINDS. SATURDAY...MVFR CIGS POSSIBLE. SOUTH WINDS. SUNDAY...MVFR CIGS POSSIBLE. SLGT CHANCE OF RAIN. SOUTH WINDS. RATZER && .MARINE... 227 PM CST LOW PRESSURE IS OVER NORTHERN WISCONSIN AND IT WILL WEAKEN AS IT MOVES ACROSS THE LAKE TONIGHT. WINDS TURN NORTHWEST BEHIND THE LOWS COLD FRONT AND THEN THEY TURN NORTH AS HIGH PRESSURE BUILDS OVER MINNESOTA. THE GRADIENT TIGHTENS BETWEEN THE HIGH AND LOW WITH 30 KT NORTH WINDS EXPECTED ACROSS THE LAKE TOMORROW. WINDS AND WAVES WILL INCREASE IN THE NEARSHORE WATERS SO HOISTED A SMALL CRAFT ADVISORY BEGINNING EARLY TUESDAY MORNING. WINDS DIMINISH TUESDAY NIGHT AS THE HIGH APPROACHES BUT LARGE WAVES WILL LINGER IN THE NSH ZONES. HAVE MEDIUM CONFIDENCE IN HOW LONG THE HAZARDOUS WAVES WILL LINGER...BUT HAVE THE SMALL CRAFT ADVISORY GOING INTO WEDNESDAY NIGHT. NORTH WINDS BECOME NORTHWEST AS THE HIGH MOVES DOWN THE MISSISSIPPI VALLEY WEDNESDAY NIGHT AND CONTINUE TO BACK TO SOUTHWEST BY FRIDAY AFTERNOON. THE HIGH FINALLY SHIFTS EAST OVER THE OHIO VALLEY SATURDAY WITH THE NEXT LOW FORMING OVER THE PLAINS SATURDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...6 AM TUESDAY TO 9 PM WEDNESDAY. SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 3 PM WEDNESDAY. && $$ 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 512 PM CST Mon Dec 8 2014 .SHORT TERM...(Tonight) ISSUED AT 248 PM CST MON DEC 8 2014 Cold front is pushing across central Illinois early this afternoon, located just west of Peoria and Springfield as of 2 pm. Extensive low cloud deck has been prevailing over the forecast area, with some localized dense fog along and north of the I-74 corridor. Surface observations showing visibilities and ceilings lifting behind the front, and the back edge of the cloudiness covered about the eastern third of Missouri. Well defined upper circulation evident on water vapor imagery over northeast Iowa, and this is producing some light rain and snow upstream from us. Main question for this part of the forecast is how much clearing will manage to take place. Lower clouds extend all the way back into southern North Dakota. RAP model guidance and current trajectories would suggest some clearing may take place over the far southwest parts of the forecast area for a short period, but a secondary surge of clouds is expected as the broad upper trough surrounding the aforementioned circulation swings through the Midwest this evening. Have kept the sky forecast on the pessimistic side and kept cloudy skies in the grids for tonight. Much of the associated precipitation should be just to our north, but will include some slight chance PoP`s for the northeast CWA for this evening. && .LONG TERM...(Tuesday through Monday) ISSUED AT 248 PM CST MON DEC 8 2014 As the low pressure area weakens and gets absorbed into an east coast system, a high pressure ridges will build into the area. This ridge will dominate the weather over the area through Wednesday and beyond. Some concern with lower level moisture remaining trapped under the ridge Tue through Wed, so have increased cloud cover to go mostly cloudy through Wed. As the center of the high pressure drops south into the southern Miss river valley, the ridge will remain over the area with dry weather through Thursday, the rest of the week and into the weekend. The area will also remain dominated by mid level cyclonic flow through the end of the week. Then mid level ridging, that was building in the plains, will begin to dominate the region for the weekend. Late in the weekend, the ridging will begin to push east and this will allow a frontal system to move into the area and bring rain to the region for Sun night and Monday. With high pressure dropping into the area and cyclonic flow, temps will remain cool for the next couple of days. But then as the high pressure settles south and mid level ridging builds, temps will begin to warm again. By the weekend, temps will warm to above normal, with 50s expected Sat and Sun. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 5050 PM CST MON DEC 8 2014 IFR cigs associated with the cold front will spread across most of the forecast area thru 02z associated with drizzle or light rain. Once that moves through, we expect cigs to become MVFR over most of the area with even a few breaks possible during the overnight hours. However, at this time, any breaks in the cloud cover will be short lived as the deep cyclonic flow aloft will bring about more low level moisture and cloud cover from the north for Tuesday. Outside the band of IFR cigs and rain, look for cigs to range from 1200-2500 feet after 03z and last into a good portion of Tuesday. Surface winds will become northwest across the entire area tonight with speeds averaging from 10 to 15 kts with a few gusts up to 20 kts at times this evening. Winds on Tuesday will be from the northwest to north winds are expected on Tuesday at 8 to 13 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Geelhart LONG TERM...Auten AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
317 PM CST SUN DEC 7 2014 SHORT TERM...TONIGHT THROUGH MONDAY... 314 PM CST THE MAIN WEATHER CONCERN FOR TONIGHT INTO MONDAY IS THE QUICK HIT OF A WINTERY MIX LATE TONIGHT INTO MONDAY MORNING...WITH THE POTENTIAL OF BRIEF PERIOD OF A HEAVY BURST OF SNOW ACROSS FAR NORTHERN ILLINOIS EARLY MONDAY MORNING DURING THE MORNING RUSH. WATER VAPOR IMAGERY INDICATES OUR STORM SYSTEM OF INTEREST DIGGING EAST-SOUTHEASTWARD ACROSS THE NORTHERN HIGH PLAINS. THE ASSOCIATED AREA OF SURFACE LOW PRESSURE IS EXPECTED TO TRACK QUICKLY ALONG OR NEAR THE CANADIAN BORDER THROUGH TUESDAY. WARM AIR ADVECTION/ISENTROPIC ASCENT IS ALREADY RAMPING UP ACROSS THE AREA OUT AHEAD OF THIS FEATURE...AND REGIONAL RADAR TRENDS ARE BEGINNING TO SHOW PRECIPITATION DEVELOPING TO OUR WEST-NORTHWEST IN ASSOCIATION WITH THE APPROACHING SURFACE FRONTAL BOUNDARY. THE COMBINATION OF GOOD LARGE SCALE FORCING (Q-VECTOR CONVERGENCE) ASSOCIATED WITH THE APPROACHING MID LEVEL SHORT WAVE ENERGY...ALONG WITH WHAT APPEARS MAY END UP BEING A RATHER STOUT BAND OF MID LEVEL FRONTOGENESIS...SHOULD PROVIDE A SHORT...BUT POTENTIALLY INTENSE PERIOD OF PRECIPITATION ACROSS NORTHERN ILLINOIS/NORTHWESTERN INDIANA EARLY MONDAY MORNING. MODEL SOUNDINGS ACROSS THE AREA ALL INDICATE THE PRESENCE OF SOME VERY IMPRESSIVE MID LEVEL LAPSE RATES (UP AROUND 7 DEGREES C/KM IN THE 700-500 MB LAYER) DURING THE PERIOD OF MAXIMUM FORCING FOR ASCENT. IN ADDITION...CROSS SECTIONS ACROSS NORTHERN ILLINOIS ALSO INDICATE THE PRESENCE OF NEGATIVE EPV...WITH FOLDING THETA E SURFACES IN THE 500 TO 700 MB LAYER. THIS ALL POINTS TO THE LIKELIHOOD OF A SHORT...BUT POTENTIALLY INTENSE BAND OF PRECIPITATION DURING THE MORNING RUSH ACROSS NORTHERN ILLINOIS/NORTHWESTERN INDIANA. THE CURRENT TIMING FOR THE CHICAGO METRO AREA FOR THIS BAND OF HEAVY PRECIPITATION LOOKS TO BE IN THE 12 TO 15 UTC TIME FRAME...AND AN COUPLE HOURS EARLIER ACROSS NORTH CENTRAL ILLINOIS. MODEL GUIDANCE CONTINUES TO SUGGEST THERMAL PROFILES WILL BE MARGINAL FOR SNOWFALL...WITH MAX LAYER WET BULB TEMPERATURES FROM ZERO TO +1 CELSIUS. HOWEVER...GIVEN THE LIKELIHOOD OF AN INTENSE PRECIPITATION RATES WITHIN THIS AREA OF PRECIP...I FEEL THAT SNOW...WITH SLEET IS STILL LIKELY TO BE THE PRIMARY PRECIPITATION TYPES...ESPECIALLY NORTH OF INTERSTATES 80 AND 88...WHERE THE STRONG MESOSCALE FORCING...AND HENCE MOST INTENSE DYNAMIC COLUMN COOLING WILL BE MOST LIKELY. HOWEVER...A VERY SHORT PERIOD OF RAIN/FREEZING RAIN IS ALSO POSSIBLE AS THE PRECIPITATION INITIALLY FIGHTS WITH A WARM BUT DRY LAYER AROUND 850 MB...BUT EVAPORATIVE COOLING SHOULD LEAD TO A RATHER QUICK CHANGE OVER TO SNOW. A QUICK INCH OF SNOW IS POSSIBLE...ESPECIALLY ALONG AND NORTH OF I88. WE WILL ISSUE AN SPS TO HIGHLIGHT THIS...AS IT APPEARS IT WILL BE A QUICK BURST OF SNOW DURING THE MONDAY MORNING RUSH. SOUTH OF INTERSTATE 80 SOME SNOW AND SLEET IS STILL POSSIBLE...BUT RAIN...AND EVEN A BRIEF PERIOD OF FREEZING RAIN IS EXPECTED INTO MONDAY MORNING...DUE TO SLIGHTLY WARMER MID-LEVEL TEMPERATURES. SURFACE TEMPERATURES WILL BE HOVERING RIGHT AROUND FREEZING INTO EARLY MONDAY MORNING...SO SOME MINOR ICING IS POSSIBLE...BUT I DONT SEE THIS AS MUCH OF FREEZING RAIN EVENT. PRECIPITATION SHOULD BE QUICK TO MOVE EAST OF THE AREA...BY MIDDAY TO EARLY AFTERNOON. GUIDANCE INDICATES THAT THE MID LEVELS WILL DRY OUT IN A HURRY LATER MONDAY MORNING/EARLY AFTERNOON. THUS IT APPEARS ANY LINGERING PRECIP WILL BE IN THE FORM OF VERY LIGHT RAIN OR DRIZZLE...AND GIVEN THAT TEMPERATURES SHOULD WARM WELL INTO THE 30S TOMORROW AFTERNOON AHEAD OF THE APPROACHING COLD FRONT...FREEZING WILL NOT BE AN ISSUE DURING THE AFTERNOON. KJB && .LONG TERM... 258 PM CST MONDAY NIGHT THROUGH NEXT WEEKEND... AN EXTENSION OF THE UPPER LOW FROM THE AFOREMENTIONED SYSTEM WILL MOVE OVER THE AREA MONDAY EVENING ALONG WITH REINFORCED LOW-LEVEL COLD ADVECTION AS A SECONDARY MORE CONTINENTAL COLD FRONT MOVES SOUTHWARD THROUGH THE AREA. FORECAST LIFT IS DISJOINTED SO NOT EXPECTING MUCH IF ANY PRECIPITATION...BUT DID ADD A CHANCE OF DRIZZLE AND FLURRIES MONDAY EVENING. VERTICAL SATURATION PROFILES REMAIN IFFY FOR ICE PRESENCE SO FELT COMFORTABLE MENTIONING EITHER OR. WITH TEMPERATURES COOLING CANT RULE OUT FREEZING DRIZZLE IF SOME PATCHY DRIZZLE WERE TO OCCUR...BUT AGAIN A LOW CHANCE. AS THE SYSTEM MOVES EAST-SOUTHEAST ON TUESDAY IT WILL ABSORB A SOUTHERN STREAM SYSTEM PRESENTLY ACROSS THE SOUTHERN PLAINS...FORMING A DEEP OCCLUDING LOW ACROSS THE NEW ENGLAND REGION. LONG RANGE GUIDANCE IS IN GOOD AGREEMENT WITH THIS. WITH BLOCKED FLOW OVER THE NORTHERN/MID ATLANTIC...THIS LOW WILL MOVE LITTLE THROUGH MIDWEEK...WITH THE OVERALL PATTERN BECOMING BLOCKED AND CONSIDERABLY SLOWER ACROSS THE COUNTRY. THIS MEANS QUIET WEATHER FOR OUR AREA FROM TUESDAY ONWARD. TEMPERATURES LOOK TO BE NEAR NORMAL...MAYBE SLIGHTLY BELOW...DURING MIDWEEK. A BUILDING UPPER RIDGE ACROSS THE ROCKIES DURING MIDWEEK WILL INCH/LEAN EASTWARD...HOWEVER THE LOW-LEVEL THERMAL RIDGE WILL LAG THIS. WHILE HEIGHTS WILL BE WELL ABOVE NORMAL OVER THE AREA...THE GREATEST HEIGHT AND THERMAL ANOMALIES LOOK TO REMAIN TO THE WEST AND NORTHWEST OF THE AREA ON ENSEMBLE GUIDANCE AND THE TREND HAS BEEN THIS WAY. TEMPERATURES ARE STILL ON THEIR WAY TO ABOVE NORMAL WITH THE CHANCE OF HAVING NEXT WEEKEND IN THE 50S...BUT RIGHT NOW WITHOUT STRONG LOW-LEVEL WARM ADVECTION THE MAGNITUDE MAY BE HINDERED SOME. DO THINK THE GFS IS TOO ROBUST ON LOW-LEVEL MOISTURE OVER THE WEEKEND SO HAVE LEANED MORE TOWARD THE MORE SUNNY ECMWF /ESPECIALLY FOR SATURDAY/. THE ECMWF HAS HIGHS IN THE MID-UPPER 40S. GIVEN THE PATTERN...ANY PRECIPITATION CHANCES ARE LIKELY TO SLOW FURTHER SO HAVE BACKED ANY UP UNTIL SUNDAY NIGHT. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * SOUTHEAST WINDS AROUND 10 KT THROUGH EARLY EVENING. * BAND OF MIXED PRECIPITATION EXPECTED MONDAY MORNING. MAY START AS -FZRA THEN TURN TO SHORT PERIOD OF SLEET/SNOW. IFR CIGS/VSBY LIKELY FOR A FEW HOUR PERIOD. KMD //DISCUSSION...UPDATED 18Z... NOT MUCH CHANGE IN THINKING ON THE MIXED PRECIPITATION POTENTIAL MONDAY MORNING...WITH A VERY SLIGHT SLOWING TREND IN THE ABILITY OF PRECIPITATION TO REACH THE GROUND. 12Z-14Z SEEMS TO BE THE MOST LIKELY WINDOW FOR A BURST OF WET SNOW/SLEET ACROSS THE CHICAGO LAND TERMINALS...10Z-12Z FARTHER WEST TOWARDS ROCKFORD. AS MENTIONED IN EARLIER DISCUSSIONS...PRECIPITATION MAY START AS LIGHT FREEZING RAIN IF THE INITIAL DRY AIR CAN BE OVERCOME BUT CURRENT TRENDS SUGGEST THAT THIS WINDOW MAY BE VERY SHORT. THE AIR MASS IN THE MAIN FORCING SHOULD BE COLDER AND SUPPORT A TRANSITION TO FROZEN PRECIPITATION. THIS WOULD RESULT IN A BRIEF PERIOD OF SLUSHY SNOW/SLEET ACCUMULATIONS NO HIGHER THAN 1 INCH AS SURFACE TEMPERATURES HOVER AROUND THE FREEZING MARK...BUT IT COULD COME DOWN RATHER QUICKLY. IFR CONDITIONS ARE EXPECTED DURING THIS TIME WITH POSSIBLE LIFR CONDITIONS FOR A SHORT TIME AS WELL IF THE PRECIP TYPE TURNS TO ALL SNOW. AFTERWARDS THE TREND IS TOWARD KEEPING SOME LOWER CIGS AROUND IN THE MVFR CATEGORY...WITH WINDS SHIFTING TO WESTERLY. PRECIPITATION TRANSITIONS TO LIGHT RAIN/DRIZZLE AFTER MAIN BAND PUSHES THROUGH. KMD //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN WIND TRENDS. * MEDIUM-HIGH CONFIDENCE IN A BAND OF MIXED PRECIPITATION OCCURRING MONDAY MORNING WITH IFR CONDITIONS. MEDIUM CONFIDENCE IN PROGRESSION OF PRECIP TYPE AND TIMING...THOUGH LOW CONFIDENCE ON FZRA. KMD //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR. NW WINDS. TUESDAY...VFR. NW WINDS BECOMING N. WEDNESDAY...VFR. N WINDS. THURSDAY...VFR. S WINDS. FRIDAY...VFR. S WINDS. SATURDAY...VFR. S WINDS. MDB && .MARINE... 203 PM CST SOUTHEAST TO SOUTH WINDS WILL CONTINUE TO INCREASE TONIGHT AHEAD OF QUICK MOVING LOW PRESSURE ACROSS THE UPPER MIDWEST...INCLUDING POSSIBLY TEMPORARY GALES ACROSS THE FAR NORTH. THE SOMEWHAT ONSHORE FLOW TONIGHT INTO NORTHEAST ILLINOIS...MAINLY NORTH OF CHICAGO...STILL LOOKS TO BRING SMALL CRAFT ADVISORY CONDITIONS THERE INTO EARLY MONDAY MORNING. AS THE LOW TRACKS FROM LAKE SUPERIOR TO LAKE HURON MONDAY AND MONDAY NIGHT...WINDS WILL TURN TO WEST ON MONDAY EVENING AND THEN NORTHWEST LATE MONDAY NIGHT AND FINALLY TO NORTH BY MIDDAY TUESDAY. WIDESPREAD 30 KT WINDS ARE EXPECTED TUESDAY IN THIS COLD AIR ADVECTION. THE WEATHER PATTERN IS FORECAST TO BECOME VERY BLOCKED FOR THE LATTER HALF OF THE WEEK...WITH THE LAKE LOCKED BETWEEN A RIDGE TO ITS IMMEDIATE WEST AND A LOW OVER THE NORTHEAST. THIS MEANS GENERALLY 10-15 KT NORTHWEST TO WEST WINDS. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 AM MONDAY. && $$ 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 304 PM CST Sun Dec 7 2014 .SHORT TERM...(Tonight) ISSUED AT 304 PM CST SUN DEC 7 2014 Mid and high clouds are expansive across the forecast area this afternoon, although some patches of stratocumulus have been developing. Larger shield of clouds around 1500 feet starting to cross the Missouri/Illinois border as well. Water vapor imagery showing the incoming clipper system quite nicely over the Dakotas. Latest surface map shows the low center over northern North Dakota, and its trailing cold front into central Nebraska and western Kansas. Main concern is with precipitation types across the north. Still appears that the precipitation in our area will hold off until after midnight, and not reach areas east of I-57 until sunrise. The remainder of the morning model suite has arrived, and all are generally trending warmer ahead of the incoming clipper. The NAM and RAP are most prominent with the 850 mb warm nose, around +4 to +5C, and suggest all rain even in the far north. The GFS, ECMWF and Canadian models with a more modest +1 to +3C. These all indicate surface temperatures above freezing as well, but would indicate a bit of sleet potential as well. Have leaned a bit more on the warmer side of the guidance and kept it mostly rain, but included a slight chance of freezing rain from around Champaign northwest through Bloomington to Minonk. Surface temperatures will remain borderline with the ice potential, but lows around 33-34 degrees will be common in much of the forecast area. && .LONG TERM...(Monday through Sunday) ISSUED AT 304 PM CST SUN DEC 7 2014 The initial shortwave feature associated with the clipper system will cross the central IL forecast area by mid afternoon, bringing the best lift and precipitation with the system. Models over the past day have trended upward with precipitation amounts and now yield a consensus of a few hundredths to a tenth of an inch. Precipitation type could linger as freezing rain from around Danville northwestward until around 8 a.m. but surface temperatures will quickly rise above freezing to yield all rain through the day. Subsidence aloft will follow the initial shortwave causing precipitation to diminish from west to east late morning through afternoon. Shallow stratus looks to continue into the evening as cold advection in northwest winds push into the region. Model soundings indicate the moisture trapped below a subsidence inversion will be shallow enough that any precipitation would likely be drizzle, although some potential for snow flurries with little accumulation exists. Below normal temperatures in NW flow will continue for midweek. A deepening low over the east coast will likely cause a blocked pattern with a slowly moving ridge over the plains. Models have been inconsistent with handling next weekend but have trended forecast toward the ECMWF solution which holds the ridge further west and looks more reasonable. As a result, will hold drier and slightly cooler temperatures longer into the weekend. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 1136 AM CST SUN DEC 7 2014 Main time frame of concern will be after 06Z, as a clipper system moves in from the west. Ahead of it, VFR conditions to continue with only high clouds present, and southeast winds gradually trending more southerly this evening. The clipper is expected to spread light rain into the KPIA/KBMI areas in the 09-12Z time frame. Surface temperatures may be cold enough for some brief freezing rain especially at KBMI, but have held off on mention for this for now as confidence is not especially high. Further south, have kept the VCSH mention as there will still be some dry air to overcome late tonight. Have kept the development of MVFR conditions later in the period as visibilities lower ahead of the clipper, and ceilings around 1500 feet or so should overspread the region late tonight. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Geelhart LONG TERM...Onton AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1147 AM CST SUN DEC 7 2014 .SHORT TERM... 427 AM CST A HIGH AMPLITUDE...PROGRESSIVE UPPER LEVEL PATTERN WILL BRING VERY CHANGEABLE WEATHER TO THE REGION FOR THE NEXT SEVERAL DAYS...THOUGH THE MAIN CONCERN WILL BE A WINTRY MIXED PCPN EVENT FOR SUNDAY NIGHT INTO MONDAY MORNING. THROUGH MONDAY NIGHT... FOR THE REMAINDER OF THE NIGHT AND INTO SUNDAY MORNING...CONDITIONS WILL REMAIN QUIET WITH INCREASING HIGH CLOUD COVER WHICH WILL LIMIT ANY FURTHER RADIATIVE COOLING AND TEMPERATURES ACROSS THE REGION SHOULD BOTTOM OUT IN THE LOWER TO MIDDLE 20S...EXCEPT FOR DOWNTOWN CHICAGO WHICH WILL ONLY DROP TO AROUND 30F. THE REMAINDER OF SUNDAY SHOULD BE RELATIVELY INNOCUOUS WITH CONTINUED INCREASING MID AND HIGH LEVEL CLOUD COVER. AS THE CENTER OF A LARGE AREA OF HIGH PRESSURE SHIFTS FROM THE UPPER GREAT LAKES TO ERN CANADA...A LOW PRESSURE SYSTEM WILL MOVE OUT OF THE SRN CANADIAN ROCKIES...DRAGGING A WEAK COLD FRONT INTO THE PLAINS. LOW LEVEL FLOW WILL BECOME MORE SELY AHEAD OF THE APPROACHING SYSTEM...THOUGH WITH HIGH PRESSURE RIDGING STILL NOSING SOUTHWEST INTO THE LOWER MISSISSIPPI VALLEY...EVEN AS TEMPERATURES RISE INTO UPPER 30S...DEWPOINTS WILL REMAIN RELATIVELY LOW...REMAINING IN THE LOW 20S. AS THE SYSTEM APPROACHES THE REGION...CONCERNS WILL BECOME PCPN TYPE AND AMOUNT WITH THE SYSTEM. PREVIOUS MODEL RUNS HAD MAINTAINED A RELATIVELY DRY ENVIRONMENT AS THE GULF OF MEXICO REMAIN CUT OFF FROM THE NRN STREAM SYSTEM AND ANY LOW LEVEL MOISTURE TRANSPORT WILL HAVE TO TAKE A LONG PATH AROUND THE PERIPHERY OF THE SFC RIDGE BEFORE REACHING INTO THE MIDDLE MISSISSIPPI VALLEY. HOWEVER...THE LATEST MODEL RUNS ARE INDICATING MORE MOISTURE AVAILABLE TO THE SYSTEM WITH FORECAST PWATS AROUND 3/4 INCH AND MANY MODELS ARE PAINTING MORE QPF THAN PREVIOUS RUNS. HAVE SOME CONCERN THAT THE MODELS ARE OVER FORECASTING MOISTURE CONTENT AND QPF...SO HAVE GONE WITH A MORE CONSERVATIVE APPROACH TO QPF AMOUNTS THAT WHAT MANY OF THE MODELS WOULD SUGGEST. HOWEVER...STILL FEEL THAT THERE WILL BE ENOUGH DEEP LAYER MOISTURE TO PRODUCE MEASURABLE PCPN ACROSS THE REGION. THE REAL CONCERN WILL BE PCPN TYPE WITH AMOUNTS MORE OF A SECONDARY CONCERN. THIS IS LARGELY BECAUSE THE GUIDANCE IS INDICATING AN INTRUSION OF WARM AIR ABOVE A NEARLY SATURATED...BUT BELOW FREEZING SFC LAYER. THE LATEST RUNS OF THE LOCAL WRFARW...WHICH WAS LARGELY FOLLOWED FOR THE FINER SCALE DETAILS OF THE PCPN TYPE TREND INDICATES A RATHER THICK WARM LAYER WITH MAX TEMPS WITHING THE WARM LAYER OF +3 TO +5C ABOVE A SURFACE BASED INVERSION WITH SFC TEMPERATURES ARND 30F BY THE TIME THE LEADING EDGE OF THE PCPN MOVES INTO THE FAR NWRN PORTIONS OF THE CWA. THE LATEST GUIDANCE SUGGESTS THAT PCPN COULD MOVE INTO THE NWRN PORTIONS OF THE CWA BY ARND 06Z...AND WITH SFC TEMPS OF 30F...BELOW THE DEEP WARM LAYER...PCPN SHOULD LARGELY BE FREEZING RAIN. THE LEADING EDGE OF THE FREEZING RAIN SHOULD STEADILY CROSS THE CWA...REACHING THE CHICAGO METRO AREA DURG THE PREDAWN HOURS. A RATHER STRONG MID LEVEL SHORTWAVE...WITH 700MB OMEGA MAX MOVING ACROSS THE AREA...THERE WILL LIKELY BE A PERIOD OF SLEET MIXING IN WITH THE FREEZING RAIN DURG THE MORNING HOURS. PCPN TYPE BECOME A LITTLE MORE COMPLICATED BY LATE MORNING AND INTO THE AFTERNOON HOURS. MID LEVEL DRY AIR SHOULD MOVE IN RELATIVELY QUICKLY AS THE HEAVIEST BAND OF PCPN TRACKS FROM WEST TO EAST ACROSS THE AREA. THE MID LEVEL DRYING COULD OCCUR BEHIND THE PASSAGE OF THE SFC COLD FRONT. HOWEVER...SINCE THIS SYSTEM IS A MODIFIED PACIFIC SYSTEM...TEMPERATURES SHOULD NOT DROP OFF QUICKLY OR SIGNIFICANTLY FOLLOWING THE FROPA...BUT THERE COULD BE A QUICK BURST OF MODERATE SNOW FOR A SHORT PERIOD WITH THE FROPA AS THE MID LEVEL WARM LAYER ERODES AND THE ENTIRE COLUMN DROPS BELOW FREEZING. LATEST THINKING WITH THAT THE ENTIRE CWA SHOULD SEE A LEAST A LIGHT GLAZING OF FREEZING RAIN...WITH PERHAPS A LIGHT ICE ACCUMULATION OVER THE NORTHERN PORTIONS OF THE CWA...WHERE QPF AND FORCING WILL BE STRONGER. ALSO...IT LOOKS LIKE THE ROCKFORD AREA SHOULD HAVE THE BETTER OPPORTUNITY FOR ACCUMULATING SNOWFALL AS THE THE BEST TIMING FOR A BURST OF HEAVIER SNOW WILL OCCUR EARLIER IN THE DAY...BEFORE SFC TEMPS HAVE A CHANCE TO RISE ABOVE FREEZING. BY THE TIME THAT THE COLD FRONT REACHES THE ERN PORTIONS OF THE CWA...SFC TEMPERATURES MAY WARM ABOVE FREEZING AND THE CHANCES FOR MUCH MEASURABLE SNOWFALL WILL BE LOWER....WITH THE FAR SOUTHERN AND SERN PORTION OF THE CWA...LOCATIONS GENERALLY SOUTH OF THE KANKAKEE RIVER POSSIBLY ONLY SEEING SOME LIGHT FREEZING RAIN BEFORE BRIEFLY CHANGING OVER TO SNOW AND THEN EVENTUALLY CHANGING OVER TO ALL RAIN BY LATE MONDAY MORNING. SO...THE LATEST FORECAST UPDATE WILL INCLUDE MEASURABLE SNOW NORTH OF THE IL/KANKAKEE RIVERS...WITH THE I39 CORRIDOR SEEING AS MUCH A 1 INCH OF TOTAL ACCUMULATION...BEFORE THE WARMER AIR MOVES IN AND MELTS ANY ACCUMULATING SNOW. LOCATIONS NORTH OF THE RIVERS AND EAST OF I-39 SHOULD ONLY SEE AROUND A HALF INCH SO SO OF SNOW. THE GREATEST CONCERN WILL BE IMPACTS ON TRAVEL AS THE FREEZING/FROZEN PCPN WILL BE MOVING ACROSS THE AREA AROUND THE MORNING RUSH HOURS...AND WITH EVEN LIGHT FREEZING RAIN...THERE COULD BE TRAVEL DIFFICULTIES. BY LATE MORNING...SFC TEMPS SHOULD RISE ABOVE FREEZING AND WITH SFC FLOW ONLY VEERING FROM SWLY TO WLY WITH THE FROPA...LITTLE ACTUAL COOLING IS EXPECTED WITH THE FROPA AND TEMPERATURES COULD REACH INTO THE UPPER 30S TO AROUND 40F BY LATE MONDAY AFTERNOON. THE MORE SIGNIFICANT COLD ADVECTION WILL NOT BEGIN UNTIL THE LATE EVENING HOURS AS THE NEXT SFC HIGH BUILDS ACROSS THE NRN PLAINS...SETTING UP NWLY FLOW ACROSS THE REGION AND BY TUESDAY MORNING...TEMPERATURES SHOULD DROP INTO THE MIDDLE TO UPPER 20S. KREIN && .LONG TERM... 427 AM CST TUESDAY THROUGH NEXT SATURDAY... THE EXTENDED FORECAST PERIOD LOOK TO BE GENERALLY QUIET ACROSS THE MIDWEST AS DEEP LOW PRESSURE DEVELOPS OF THE MID ATLANTIC COAST...SLOWING THE PROGRESSION OF THE SFC HIGH ACROSS THE AREA. THE LATEST LONGER RANGE GUIDANCE SUGGESTS THAT THE CENTER OF THE HIGH WILL BE SHUNTED INTO SERN CANADA BY THE DEEP LOW OFF THE EAST COAST...WITH RIDGING EXTENDING THROUGH THE GREAT LAKES AND MIDDLE MISSISSIPPI VALLEY THROUGH MUCH OF THE WEEK. TEMPERATURES SHOULD GENERALLY BE SEASONABLE WITH HIGHS IN THE LOWER TO MIDDLE 30S THROUGH THURSDAY WITH OVERNIGHT LOWS IN THE LOWER TO MIDDLE 20S. PREVAILING HIGH PRESSURE WILL HELP KEEP THE REGION DRY AND NO ADDITIONAL PCPN IS LIKELY THROUGH MUCH OF THE WEEK. THE MODELS CONTINUE TO ADVERTISE A SIGNIFICANT WARMING TREND BY THE END OF THE WEEK. THE MAIN IDEA IS THAT THE DEEP COASTAL LOW AND THE PARENT UPPER LOW WILL REMAIN NEARLY STATIONARY OVER THE MID ATLANTIC COAST...WHILE STRONG UPPER RIDGING BUILDS OVER THE WRN CONUS BY FRIDAY...THE UPPER RIDGE IS EXPECTED TO BUILD OVER THE UPPER MISSISSIPPI VALLEY AND ACROSS THE WRN GREAT LAKES BY NEXT SATURDAY. THE LONGER RANGE TEMPERATURE GUIDANCE IS SUGGESTING THAT TEMPERATURES COULD REACH INTO THE LOWER TO MIDDLE 40S BY FRIDAY AND MIDDLE TO UPPER 40S FOR SATURDAY. HOWEVER...LONGER RANGE TEMPERATURE GUIDANCE TENDS TO TREND A LITTLE CLOSER TO CLIMATOLOGY TOWARD THE END OF THE FORECAST PERIOD...SO THE GOING FORECAST OF MIDDLE TO UPPER 40S FOR NEXT SATURDAY COULD BE ON THE CONSERVATIVE SIDE...AND WITH THE TYPE OF UPPER LEVEL PATTERN EVOLVING...THERE IS THE POTENTIAL THAT TEMPERATURES FOR FRIDAY AND SATURDAY COULD VERY WELL APPROACH OR EXCEED THE 50F MARK. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * SOUTHEAST WINDS AROUND 10 KT TODAY. * BAND OF MIXED PRECIPITATION EXPECTED MONDAY MORNING. MAY START AS -FZRA THEN TURN TO SHORT PERIOD OF SLEET/SNOW. IFR CIGS/VSBY LIKELY FOR A FEW HOUR PERIOD. KMD //DISCUSSION...UPDATED 18Z... NOT MUCH CHANGE IN THINKING ON THE MIXED PRECIPITATION POTENTIAL MONDAY MORNING...WITH A VERY SLIGHT SLOWING TREND IN THE ABILITY OF PRECIPITATION TO REACH THE GROUND. 12Z-14Z SEEMS TO BE THE MOST LIKELY WINDOW FOR A BURST OF WET SNOW/SLEET ACROSS THE CHICAGO LAND TERMINALS...10Z-12Z FARTHER WEST TOWARDS ROCKFORD. AS MENTIONED IN EARLIER DISCUSSIONS...PRECIPITATION MAY START AS LIGHT FREEZING RAIN IF THE INITIAL DRY AIR CAN BE OVERCOME BUT CURRENT TRENDS SUGGEST THAT THIS WINDOW MAY BE VERY SHORT. THE AIR MASS IN THE MAIN FORCING SHOULD BE COLDER AND SUPPORT A TRANSITION TO FROZEN PRECIPITATION. THIS WOULD RESULT IN A BRIEF PERIOD OF SLUSHY SNOW/SLEET ACCUMULATIONS NO HIGHER THAN 1 INCH AS SURFACE TEMPERATURES HOVER AROUND THE FREEZING MARK...BUT IT COULD COME DOWN RATHER QUICKLY. IFR CONDITIONS ARE EXPECTED DURING THIS TIME WITH POSSIBLE LIFR CONDITIONS FOR A SHORT TIME AS WELL IF THE PRECIP TYPE TURNS TO ALL SNOW. AFTERWARDS THE TREND IS TOWARD KEEPING SOME LOWER CIGS AROUND IN THE MVFR CATEGORY...WITH WINDS SHIFTING TO WESTERLY. PRECIPITATION TRANSITIONS TO LIGHT RAIN/DRIZZLE AFTER MAIN BAND PUSHES THROUGH. KMD //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN WIND TRENDS. * MEDIUM-HIGH CONFIDENCE IN A BAND OF MIXED PRECIPITATION OCCURRING MONDAY MORNING WITH IFR CONDITIONS. MEDIUM CONFIDENCE IN PROGRESSION OF PRECIP TYPE AND TIMING. KMD //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR. NW WINDS. TUESDAY...VFR. NW WINDS BECOMING N. WEDNESDAY...VFR. N WINDS. THURSDAY...VFR. S WINDS. FRIDAY...VFR. S WINDS. SATURDAY...VFR. S WINDS. MDB && .MARINE... 251 AM CST HIGH PRESSURE IS CENTERED OVER EASTERN ONTARIO EARLY THIS MORNING WITH A RIDGE AXIS EXTENDING ACROSS LAKE MICHIGAN. THIS HAS ALLOWED WINDS TO EASE AND TURN EAST TO NORTHEAST AND WILL ALLOW FOR A SHIFT TO SOUTHEAST THROUGH THE MORNING. WILL ALLOW THE SMALL CRAFT ADVISORY TO EXPIRE AS WINDS CONTINUE TO EASE ALLOWING WAVES TO BE ON A DOWNWARD TREND. WILL CONTINUE WITH A 3-5 OCCASIONAL 7 FT FORECAST. LOW PRESSURE IS OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA AND WILL BE MOVING EAST ALONG THE CANADIAN BORDER REACHING LAKE SUPERIOR BY MIDDAY MONDAY. WITH THE HIGH PRESSURE RATHER STRONG THE PRESSURE GRADIENT BETWEEN IT AND THE LOW WILL BE TIGHTENING THROUGH THE DAY DESPITE THE LOW NOT BEING TERRIBLY DEEP. AS A RESULT WIND SPEEDS WILL STEADILY INCREASE TO ABOUT 30 KT ACROSS MOST OF THE LAKE THIS EVENING WITH SOME 35 KT GALE FORCE GUSTS POSSIBLE ACROSS CENTRAL AND NORTHERN SECTIONS OVERNIGHT INTO EARLY MONDAY MORNING AS WINDS TURN MORE SOUTHERLY. WILL ISSUE A SMALL CRAFT ADVISORY FOR MOST OF THE ILLINOIS NEARSHORE FROM EARLY THIS EVENING THROUGH LATE MONDAY MORNING AS WINDS AND WAVES COME UP. WINDS WILL THEN TURN SOUTHWESTERLY MONDAY AFTERNOON AS THE LOW TRACKS TO THE EAST WITH A SHIFT TO NORTHWEST MONDAY EVENING. COLDER AIR WILL SPREAD IN ON A FAIRLY STRONG HIGH THAT WILL MOVE INTO THE MID AND UPPER MISSISSIPPI RIVER VALLEY TUESDAY WHICH WILL ALLOW NORTHWEST WINDS TO INCREASE EARLY TUESDAY MORNING AND TURN NORTH THROUGH THE DAY. SPEEDS WILL THEN EASE INTO TUESDAY NIGHT AS THE HIGH MOVES CLOSER THEN SPREADS ACROSS THE LAKE LATER WEDNESDAY. THE HIGH WILL BE SLOW TO SHIFT TO THE EAST BUT WINDS WILL TURN WESTERLY AS IT DOES THURSDAY THEN SOUTHWESTERLY THURSDAY NIGHT. STEADY SOUTHWEST WINDS ARE THEN EXPECTED INTO THE WEEKEND AS THE HIGH SLOWLY MOVES OFF TO THE EAST. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...6 PM SUNDAY TO 10 AM MONDAY. && $$ 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 1136 AM CST Sun Dec 7 2014 .UPDATE... ISSUED AT 1013 AM CST SUN DEC 7 2014 Daytime forecast remains on track, as high clouds overspread the state from the west. However, some adjustments have been made to the nighttime trends ahead of the clipper system. The evening is expected to be dry, so the PoP`s have been concentrated in the post-midnight hours. Looking at the forecast soundings across the northern CWA off the early morning NAM and RAP models, a prominent warm layer around +4 to +5C will be present through the night, so have removed the mention of snow. The new GFS has a shorter time frame for the warm layer, cooling it to +2C by morning with ice crystals aloft a bit more prominent, suggesting more of a rain/snow mixture. Right now, have mainly gone with a rain/freezing rain mixture north of I-74 with temperatures in the lower 30s. && .SHORT TERM...(Today) ISSUED AT 331 AM CST SUN DEC 7 2014 Clouds have cleared out to the south tonight for now, but they are lingering very close-by. Satellite images already confirm increasing high clouds from the west. The HRRR is advertising a return of low clouds from the east-southeast across the eastern half of the area between 15z/9am and 18z/Noon today, but that seems a bit aggressive based on the current progression of clouds across Indiana and the expected wind patterns this morning. Have increased clouds from the west based on satellite and model consensus, but only trended minor increases in clouds across the east during the day for now. Will monitor the movement of low clouds toward our eastern counties for potential sky cover updates in the short term. Northeast flow early this morning is expected to evolve to east and then southeast this afternoon, as high pressure centered over the Lake Michigan departs farther east across the Great Lakes. The onset of southeast winds will increase the potential return of low clouds currently lingering across southern IL. Temperatures today will only climb about 12-13F above morning lows due to increasing clouds, with highs topping out in the upper 30s to low 40s. && .LONG TERM...(Tonight through Saturday) ISSUED AT 331 AM CST SUN DEC 7 2014 High pressure continues to build into the region, although clouds continue to dominate the Midwest. Plenty of moisture on sat imagery obscuring the llvl clouds underneath. Clearing in patches certainly not anticipated for long as llvl moisture remains trapped by continuing strong inversion over the area. The dry air aloft is not coincident with enough turbulence to break up the inversion and erode the higher RH at roughly 925 mb. This dry air will also be the first issue for eroding the approaching precip late Sun night and into Monday. Models maintaining consistency with the last two runs and continuity with one another with regards to approach and qpf after midnight tonight and into Monday. A quick front moving through the area bringing precip after midnight and through the day Monday so far looks like mostly rain, though the nrn tier of the state may see a bit more of a rain/snow/wintry mix. Concern remains whether or not the models are too quick to overcome the dry air aloft or whether or not the precip may be delayed slightly. Beyond Monday`s cold front, temps cool briefly, then moderate back into the 40s for highs through the end of the week. 00z GFS agreeing with yesterdays 00z ECMWF and backing down from the precip Wed/Thursday, instead dominating the sfc map with high pressure. Pops mid week have been removed. Deepening low over the northeast/east coast causing a bit of a back up across the CONUS as it is slow to move and the models having some issue with pushing the new wave inland on the Pacific coast and managing the ridging in the middle. Seems from Friday and into the weekend the forecast becomes a bit more problematic in the details as the models work out a pattern shift again. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 1136 AM CST SUN DEC 7 2014 Main time frame of concern will be after 06Z, as a clipper system moves in from the west. Ahead of it, VFR conditions to continue with only high clouds present, and southeast winds gradually trending more southerly this evening. The clipper is expected to spread light rain into the KPIA/KBMI areas in the 09-12Z time frame. Surface temperatures may be cold enough for some brief freezing rain especially at KBMI, but have held off on mention for this for now as confidence is not especially high. Further south, have kept the VCSH mention as there will still be some dry air to overcome late tonight. Have kept the development of MVFR conditions later in the period as visibilities lower ahead of the clipper, and ceilings around 1500 feet or so should overspread the region late tonight. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SHORT TERM...Shimon LONG TERM...HJS AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1017 AM CST SUN DEC 7 2014 .SHORT TERM... 427 AM CST A HIGH AMPLITUDE...PROGRESSIVE UPPER LEVEL PATTERN WILL BRING VERY CHANGEABLE WEATHER TO THE REGION FOR THE NEXT SEVERAL DAYS...THOUGH THE MAIN CONCERN WILL BE A WINTRY MIXED PCPN EVENT FOR SUNDAY NIGHT INTO MONDAY MORNING. THROUGH MONDAY NIGHT... FOR THE REMAINDER OF THE NIGHT AND INTO SUNDAY MORNING...CONDITIONS WILL REMAIN QUIET WITH INCREASING HIGH CLOUD COVER WHICH WILL LIMIT ANY FURTHER RADIATIVE COOLING AND TEMPERATURES ACROSS THE REGION SHOULD BOTTOM OUT IN THE LOWER TO MIDDLE 20S...EXCEPT FOR DOWNTOWN CHICAGO WHICH WILL ONLY DROP TO AROUND 30F. THE REMAINDER OF SUNDAY SHOULD BE RELATIVELY INNOCUOUS WITH CONTINUED INCREASING MID AND HIGH LEVEL CLOUD COVER. AS THE CENTER OF A LARGE AREA OF HIGH PRESSURE SHIFTS FROM THE UPPER GREAT LAKES TO ERN CANADA...A LOW PRESSURE SYSTEM WILL MOVE OUT OF THE SRN CANADIAN ROCKIES...DRAGGING A WEAK COLD FRONT INTO THE PLAINS. LOW LEVEL FLOW WILL BECOME MORE SELY AHEAD OF THE APPROACHING SYSTEM...THOUGH WITH HIGH PRESSURE RIDGING STILL NOSING SOUTHWEST INTO THE LOWER MISSISSIPPI VALLEY...EVEN AS TEMPERATURES RISE INTO UPPER 30S...DEWPOINTS WILL REMAIN RELATIVELY LOW...REMAINING IN THE LOW 20S. AS THE SYSTEM APPROACHES THE REGION...CONCERNS WILL BECOME PCPN TYPE AND AMOUNT WITH THE SYSTEM. PREVIOUS MODEL RUNS HAD MAINTAINED A RELATIVELY DRY ENVIRONMENT AS THE GULF OF MEXICO REMAIN CUT OFF FROM THE NRN STREAM SYSTEM AND ANY LOW LEVEL MOISTURE TRANSPORT WILL HAVE TO TAKE A LONG PATH AROUND THE PERIPHERY OF THE SFC RIDGE BEFORE REACHING INTO THE MIDDLE MISSISSIPPI VALLEY. HOWEVER...THE LATEST MODEL RUNS ARE INDICATING MORE MOISTURE AVAILABLE TO THE SYSTEM WITH FORECAST PWATS AROUND 3/4 INCH AND MANY MODELS ARE PAINTING MORE QPF THAN PREVIOUS RUNS. HAVE SOME CONCERN THAT THE MODELS ARE OVER FORECASTING MOISTURE CONTENT AND QPF...SO HAVE GONE WITH A MORE CONSERVATIVE APPROACH TO QPF AMOUNTS THAT WHAT MANY OF THE MODELS WOULD SUGGEST. HOWEVER...STILL FEEL THAT THERE WILL BE ENOUGH DEEP LAYER MOISTURE TO PRODUCE MEASURABLE PCPN ACROSS THE REGION. THE REAL CONCERN WILL BE PCPN TYPE WITH AMOUNTS MORE OF A SECONDARY CONCERN. THIS IS LARGELY BECAUSE THE GUIDANCE IS INDICATING AN INTRUSION OF WARM AIR ABOVE A NEARLY SATURATED...BUT BELOW FREEZING SFC LAYER. THE LATEST RUNS OF THE LOCAL WRFARW...WHICH WAS LARGELY FOLLOWED FOR THE FINER SCALE DETAILS OF THE PCPN TYPE TREND INDICATES A RATHER THICK WARM LAYER WITH MAX TEMPS WITHING THE WARM LAYER OF +3 TO +5C ABOVE A SURFACE BASED INVERSION WITH SFC TEMPERATURES ARND 30F BY THE TIME THE LEADING EDGE OF THE PCPN MOVES INTO THE FAR NWRN PORTIONS OF THE CWA. THE LATEST GUIDANCE SUGGESTS THAT PCPN COULD MOVE INTO THE NWRN PORTIONS OF THE CWA BY ARND 06Z...AND WITH SFC TEMPS OF 30F...BELOW THE DEEP WARM LAYER...PCPN SHOULD LARGELY BE FREEZING RAIN. THE LEADING EDGE OF THE FREEZING RAIN SHOULD STEADILY CROSS THE CWA...REACHING THE CHICAGO METRO AREA DURG THE PREDAWN HOURS. A RATHER STRONG MID LEVEL SHORTWAVE...WITH 700MB OMEGA MAX MOVING ACROSS THE AREA...THERE WILL LIKELY BE A PERIOD OF SLEET MIXING IN WITH THE FREEZING RAIN DURG THE MORNING HOURS. PCPN TYPE BECOME A LITTLE MORE COMPLICATED BY LATE MORNING AND INTO THE AFTERNOON HOURS. MID LEVEL DRY AIR SHOULD MOVE IN RELATIVELY QUICKLY AS THE HEAVIEST BAND OF PCPN TRACKS FROM WEST TO EAST ACROSS THE AREA. THE MID LEVEL DRYING COULD OCCUR BEHIND THE PASSAGE OF THE SFC COLD FRONT. HOWEVER...SINCE THIS SYSTEM IS A MODIFIED PACIFIC SYSTEM...TEMPERATURES SHOULD NOT DROP OFF QUICKLY OR SIGNIFICANTLY FOLLOWING THE FROPA...BUT THERE COULD BE A QUICK BURST OF MODERATE SNOW FOR A SHORT PERIOD WITH THE FROPA AS THE MID LEVEL WARM LAYER ERODES AND THE ENTIRE COLUMN DROPS BELOW FREEZING. LATEST THINKING WITH THAT THE ENTIRE CWA SHOULD SEE A LEAST A LIGHT GLAZING OF FREEZING RAIN...WITH PERHAPS A LIGHT ICE ACCUMULATION OVER THE NORTHERN PORTIONS OF THE CWA...WHERE QPF AND FORCING WILL BE STRONGER. ALSO...IT LOOKS LIKE THE ROCKFORD AREA SHOULD HAVE THE BETTER OPPORTUNITY FOR ACCUMULATING SNOWFALL AS THE THE BEST TIMING FOR A BURST OF HEAVIER SNOW WILL OCCUR EARLIER IN THE DAY...BEFORE SFC TEMPS HAVE A CHANCE TO RISE ABOVE FREEZING. BY THE TIME THAT THE COLD FRONT REACHES THE ERN PORTIONS OF THE CWA...SFC TEMPERATURES MAY WARM ABOVE FREEZING AND THE CHANCES FOR MUCH MEASURABLE SNOWFALL WILL BE LOWER....WITH THE FAR SOUTHERN AND SERN PORTION OF THE CWA...LOCATIONS GENERALLY SOUTH OF THE KANKAKEE RIVER POSSIBLY ONLY SEEING SOME LIGHT FREEZING RAIN BEFORE BRIEFLY CHANGING OVER TO SNOW AND THEN EVENTUALLY CHANGING OVER TO ALL RAIN BY LATE MONDAY MORNING. SO...THE LATEST FORECAST UPDATE WILL INCLUDE MEASURABLE SNOW NORTH OF THE IL/KANKAKEE RIVERS...WITH THE I39 CORRIDOR SEEING AS MUCH A 1 INCH OF TOTAL ACCUMULATION...BEFORE THE WARMER AIR MOVES IN AND MELTS ANY ACCUMULATING SNOW. LOCATIONS NORTH OF THE RIVERS AND EAST OF I-39 SHOULD ONLY SEE AROUND A HALF INCH SO SO OF SNOW. THE GREATEST CONCERN WILL BE IMPACTS ON TRAVEL AS THE FREEZING/FROZEN PCPN WILL BE MOVING ACROSS THE AREA AROUND THE MORNING RUSH HOURS...AND WITH EVEN LIGHT FREEZING RAIN...THERE COULD BE TRAVEL DIFFICULTIES. BY LATE MORNING...SFC TEMPS SHOULD RISE ABOVE FREEZING AND WITH SFC FLOW ONLY VEERING FROM SWLY TO WLY WITH THE FROPA...LITTLE ACTUAL COOLING IS EXPECTED WITH THE FROPA AND TEMPERATURES COULD REACH INTO THE UPPER 30S TO AROUND 40F BY LATE MONDAY AFTERNOON. THE MORE SIGNIFICANT COLD ADVECTION WILL NOT BEGIN UNTIL THE LATE EVENING HOURS AS THE NEXT SFC HIGH BUILDS ACROSS THE NRN PLAINS...SETTING UP NWLY FLOW ACROSS THE REGION AND BY TUESDAY MORNING...TEMPERATURES SHOULD DROP INTO THE MIDDLE TO UPPER 20S. KREIN && .LONG TERM... 427 AM CST TUESDAY THROUGH NEXT SATURDAY... THE EXTENDED FORECAST PERIOD LOOK TO BE GENERALLY QUIET ACROSS THE MIDWEST AS DEEP LOW PRESSURE DEVELOPS OF THE MID ATLANTIC COAST...SLOWING THE PROGRESSION OF THE SFC HIGH ACROSS THE AREA. THE LATEST LONGER RANGE GUIDANCE SUGGESTS THAT THE CENTER OF THE HIGH WILL BE SHUNTED INTO SERN CANADA BY THE DEEP LOW OFF THE EAST COAST...WITH RIDGING EXTENDING THROUGH THE GREAT LAKES AND MIDDLE MISSISSIPPI VALLEY THROUGH MUCH OF THE WEEK. TEMPERATURES SHOULD GENERALLY BE SEASONABLE WITH HIGHS IN THE LOWER TO MIDDLE 30S THROUGH THURSDAY WITH OVERNIGHT LOWS IN THE LOWER TO MIDDLE 20S. PREVAILING HIGH PRESSURE WILL HELP KEEP THE REGION DRY AND NO ADDITIONAL PCPN IS LIKELY THROUGH MUCH OF THE WEEK. THE MODELS CONTINUE TO ADVERTISE A SIGNIFICANT WARMING TREND BY THE END OF THE WEEK. THE MAIN IDEA IS THAT THE DEEP COASTAL LOW AND THE PARENT UPPER LOW WILL REMAIN NEARLY STATIONARY OVER THE MID ATLANTIC COAST...WHILE STRONG UPPER RIDGING BUILDS OVER THE WRN CONUS BY FRIDAY...THE UPPER RIDGE IS EXPECTED TO BUILD OVER THE UPPER MISSISSIPPI VALLEY AND ACROSS THE WRN GREAT LAKES BY NEXT SATURDAY. THE LONGER RANGE TEMPERATURE GUIDANCE IS SUGGESTING THAT TEMPERATURES COULD REACH INTO THE LOWER TO MIDDLE 40S BY FRIDAY AND MIDDLE TO UPPER 40S FOR SATURDAY. HOWEVER...LONGER RANGE TEMPERATURE GUIDANCE TENDS TO TREND A LITTLE CLOSER TO CLIMATOLOGY TOWARD THE END OF THE FORECAST PERIOD...SO THE GOING FORECAST OF MIDDLE TO UPPER 40S FOR NEXT SATURDAY COULD BE ON THE CONSERVATIVE SIDE...AND WITH THE TYPE OF UPPER LEVEL PATTERN EVOLVING...THERE IS THE POTENTIAL THAT TEMPERATURES FOR FRIDAY AND SATURDAY COULD VERY WELL APPROACH OR EXCEED THE 50F MARK. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * SOUTHEAST WINDS AROUND 10 KT TODAY. * BAND OF MIXED PRECIPITATION EXPECTED MONDAY MORNING. MAY START AS -FZRA THEN TURN TO SHORT PERIOD OF SLEET/SNOW. IFR CIGS/VSBY POSSIBLE FOR A FEW HOUR PERIOD. KMD //DISCUSSION...UPDATED 12Z... HIGH PRESSURE RIDGING IS ACROSS THE AREA THIS MORNING BUT WILL BE SHIFTING TO THE EAST. THIS WILL RESULT IN STEADY SOUTHEAST WINDS THROUGH THE DAY WITH VFR CONDITIONS. LOW PRESSURE WILL MOVE ACROSS THE AREA MONDAY MORNING BRINGING A PERIOD OF MIXED PRECIPITATION WITH IT. A FEW HOUR PERIOD IS EXPECTED TO BEGIN TOWARD 09Z OUT NEAR RFD AND TOWARD 11Z IN THE CHICAGO AREA. THE DETAILS REMAIN IN FLUX BUT THE LATEST THINKING IS THAT PRECIPITATION WILL START OUT AS A SHORT PERIOD OF FREEZING RAIN THEN TRANSITION TO A MIX OF SLEET AND SNOW FOR A 1-3 HOUR PERIOD. FORCING IS STRONG FOR A SHORT TIME SO IT IS POSSIBLE THAT A PERIOD OF MODERATE SNOW OCCURS LEADING TO SOME SLUSHY ACCUMULATION. PRECIPITATION WILL INITIALLY BE FIGHTING A LAYER OF DRY AIR SO ONSET COULD BE DELAYED AND THIS MAY ALSO AFFECT THE PROGRESSION OF PRECIP TYPES. PRECIP INTENSITY WILL QUICKLY DIMINISH MID TO LATE MORNING MONDAY WITH LIGHT RAIN OR DRIZZLE POSSIBLE AS TEMPERATURES WARM ABOVE FREEZING. A PERIOD OF IFR CIGS IS EXPECTED PROVIDED DECENT PRECIP OCCURS AND IFR VSBY WOULD BE LIKELY IF A SHORT PERIOD OF MAINLY SNOW CAN OCCUR. BE SURE TO CHECK BACK FOR FURTHER UPDATES... MDB //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN WIND TRENDS. * MEDIUM-HIGH CONFIDENCE IN A BAND OF MIXED PRECIPITATION OCCURRING MONDAY MORNING. MEDIUM CONFIDENCE IN PROGRESSION OF PRECIP TYPE AND TIMING. KMD //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR. NW WINDS. TUESDAY...VFR. NW WINDS BECOMING N. WEDNESDAY...VFR. N WINDS. THURSDAY...VFR. S WINDS. FRIDAY...VFR. S WINDS. SATURDAY...VFR. S WINDS. MDB && .MARINE... 251 AM CST HIGH PRESSURE IS CENTERED OVER EASTERN ONTARIO EARLY THIS MORNING WITH A RIDGE AXIS EXTENDING ACROSS LAKE MICHIGAN. THIS HAS ALLOWED WINDS TO EASE AND TURN EAST TO NORTHEAST AND WILL ALLOW FOR A SHIFT TO SOUTHEAST THROUGH THE MORNING. WILL ALLOW THE SMALL CRAFT ADVISORY TO EXPIRE AS WINDS CONTINUE TO EASE ALLOWING WAVES TO BE ON A DOWNWARD TREND. WILL CONTINUE WITH A 3-5 OCCASIONAL 7 FT FORECAST. LOW PRESSURE IS OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA AND WILL BE MOVING EAST ALONG THE CANADIAN BORDER REACHING LAKE SUPERIOR BY MIDDAY MONDAY. WITH THE HIGH PRESSURE RATHER STRONG THE PRESSURE GRADIENT BETWEEN IT AND THE LOW WILL BE TIGHTENING THROUGH THE DAY DESPITE THE LOW NOT BEING TERRIBLY DEEP. AS A RESULT WIND SPEEDS WILL STEADILY INCREASE TO ABOUT 30 KT ACROSS MOST OF THE LAKE THIS EVENING WITH SOME 35 KT GALE FORCE GUSTS POSSIBLE ACROSS CENTRAL AND NORTHERN SECTIONS OVERNIGHT INTO EARLY MONDAY MORNING AS WINDS TURN MORE SOUTHERLY. WILL ISSUE A SMALL CRAFT ADVISORY FOR MOST OF THE ILLINOIS NEARSHORE FROM EARLY THIS EVENING THROUGH LATE MONDAY MORNING AS WINDS AND WAVES COME UP. WINDS WILL THEN TURN SOUTHWESTERLY MONDAY AFTERNOON AS THE LOW TRACKS TO THE EAST WITH A SHIFT TO NORTHWEST MONDAY EVENING. COLDER AIR WILL SPREAD IN ON A FAIRLY STRONG HIGH THAT WILL MOVE INTO THE MID AND UPPER MISSISSIPPI RIVER VALLEY TUESDAY WHICH WILL ALLOW NORTHWEST WINDS TO INCREASE EARLY TUESDAY MORNING AND TURN NORTH THROUGH THE DAY. SPEEDS WILL THEN EASE INTO TUESDAY NIGHT AS THE HIGH MOVES CLOSER THEN SPREADS ACROSS THE LAKE LATER WEDNESDAY. THE HIGH WILL BE SLOW TO SHIFT TO THE EAST BUT WINDS WILL TURN WESTERLY AS IT DOES THURSDAY THEN SOUTHWESTERLY THURSDAY NIGHT. STEADY SOUTHWEST WINDS ARE THEN EXPECTED INTO THE WEEKEND AS THE HIGH SLOWLY MOVES OFF TO THE EAST. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...6 PM SUNDAY TO 10 AM MONDAY. && $$ 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 1014 AM CST Sun Dec 7 2014 .UPDATE... ISSUED AT 1013 AM CST SUN DEC 7 2014 Daytime forecast remains on track, as high clouds overspread the state from the west. However, some adjustments have been made to the nighttime trends ahead of the clipper system. The evening is expected to be dry, so the PoP`s have been concentrated in the post-midnight hours. Looking at the forecast soundings across the northern CWA off the early morning NAM and RAP models, a prominent warm layer around +4 to +5C will be present through the night, so have removed the mention of snow. The new GFS has a shorter time frame for the warm layer, cooling it to +2C by morning with ice crystals aloft a bit more prominent, suggesting more of a rain/snow mixture. Right now, have mainly gone with a rain/freezing rain mixture north of I-74 with temperatures in the lower 30s. && .SHORT TERM...(Today) ISSUED AT 331 AM CST SUN DEC 7 2014 Clouds have cleared out to the south tonight for now, but they are lingering very close-by. Satellite images already confirm increasing high clouds from the west. The HRRR is advertising a return of low clouds from the east-southeast across the eastern half of the area between 15z/9am and 18z/Noon today, but that seems a bit aggressive based on the current progression of clouds across Indiana and the expected wind patterns this morning. Have increased clouds from the west based on satellite and model consensus, but only trended minor increases in clouds across the east during the day for now. Will monitor the movement of low clouds toward our eastern counties for potential sky cover updates in the short term. Northeast flow early this morning is expected to evolve to east and then southeast this afternoon, as high pressure centered over the Lake Michigan departs farther east across the Great Lakes. The onset of southeast winds will increase the potential return of low clouds currently lingering across southern IL. Temperatures today will only climb about 12-13F above morning lows due to increasing clouds, with highs topping out in the upper 30s to low 40s. && .LONG TERM...(Tonight through Saturday) ISSUED AT 331 AM CST SUN DEC 7 2014 High pressure continues to build into the region, although clouds continue to dominate the Midwest. Plenty of moisture on sat imagery obscuring the llvl clouds underneath. Clearing in patches certainly not anticipated for long as llvl moisture remains trapped by continuing strong inversion over the area. The dry air aloft is not coincident with enough turbulence to break up the inversion and erode the higher RH at roughly 925 mb. This dry air will also be the first issue for eroding the approaching precip late Sun night and into Monday. Models maintaining consistency with the last two runs and continuity with one another with regards to approach and qpf after midnight tonight and into Monday. A quick front moving through the area bringing precip after midnight and through the day Monday so far looks like mostly rain, though the nrn tier of the state may see a bit more of a rain/snow/wintry mix. Concern remains whether or not the models are too quick to overcome the dry air aloft or whether or not the precip may be delayed slightly. Beyond Monday`s cold front, temps cool briefly, then moderate back into the 40s for highs through the end of the week. 00z GFS agreeing with yesterdays 00z ECMWF and backing down from the precip Wed/Thursday, instead dominating the sfc map with high pressure. Pops mid week have been removed. Deepening low over the northeast/east coast causing a bit of a back up across the CONUS as it is slow to move and the models having some issue with pushing the new wave inland on the Pacific coast and managing the ridging in the middle. Seems from Friday and into the weekend the forecast becomes a bit more problematic in the details as the models work out a pattern shift again. && .AVIATION...(For the 12Z TAFS through 12Z Monday morning) ISSUED AT 554 AM CST SUN DEC 7 2014 High pressure centered over lower Michigan and extending SW into IL will slide east today. That movement will cause our surface winds to shift from NE to SE by this afternoon, while increasing to 10-14kt. High clouds will blanket the entire state today, with low clouds lurking just south of our forecast area already at 12z/6am. As winds shift to SE, that cloud mass will eventually gain momentum toward the terminal sites. HRRR indicates that SPI and DEC will have the higher potential of seeing a return of MVFR clouds after 22z/4pm, with the clouds eventually advancing all the way north to PIA/BMI/CMI during the evening. The initial push of moisture may have breaks in the ceiling per the latest HRRR, so we delayed the persistent low clouds until later evening when light rain will begin to develop from NW to SE ahead of an approaching warm front and low pressure system. While any light rain could change to freezing rain late in this TAF period, we did not include FZRA with this issuance. We only mentioned VCSH after midnight for now. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SHORT TERM...Shimon LONG TERM...HJS AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
556 AM CST SUN DEC 7 2014 .SHORT TERM... 427 AM CST A HIGH AMPLITUDE...PROGRESSIVE UPPER LEVEL PATTERN WILL BRING VERY CHANGEABLE WEATHER TO THE REGION FOR THE NEXT SEVERAL DAYS...THOUGH THE MAIN CONCERN WILL BE A WINTRY MIXED PCPN EVENT FOR SUNDAY NIGHT INTO MONDAY MORNING. THROUGH MONDAY NIGHT... FOR THE REMAINDER OF THE NIGHT AND INTO SUNDAY MORNING...CONDITIONS WILL REMAIN QUIET WITH INCREASING HIGH CLOUD COVER WHICH WILL LIMIT ANY FURTHER RADIATIVE COOLING AND TEMPERATURES ACROSS THE REGION SHOULD BOTTOM OUT IN THE LOWER TO MIDDLE 20S...EXCEPT FOR DOWNTOWN CHICAGO WHICH WILL ONLY DROP TO AROUND 30F. THE REMAINDER OF SUNDAY SHOULD BE RELATIVELY INNOCUOUS WITH CONTINUED INCREASING MID AND HIGH LEVEL CLOUD COVER. AS THE CENTER OF A LARGE AREA OF HIGH PRESSURE SHIFTS FROM THE UPPER GREAT LAKES TO ERN CANADA...A LOW PRESSURE SYSTEM WILL MOVE OUT OF THE SRN CANADIAN ROCKIES...DRAGGING A WEAK COLD FRONT INTO THE PLAINS. LOW LEVEL FLOW WILL BECOME MORE SELY AHEAD OF THE APPROACHING SYSTEM...THOUGH WITH HIGH PRESSURE RIDGING STILL NOSING SOUTHWEST INTO THE LOWER MISSISSIPPI VALLEY...EVEN AS TEMPERATURES RISE INTO UPPER 30S...DEWPOINTS WILL REMAIN RELATIVELY LOW...REMAINING IN THE LOW 20S. AS THE SYSTEM APPROACHES THE REGION...CONCERNS WILL BECOME PCPN TYPE AND AMOUNT WITH THE SYSTEM. PREVIOUS MODEL RUNS HAD MAINTAINED A RELATIVELY DRY ENVIRONMENT AS THE GULF OF MEXICO REMAIN CUT OFF FROM THE NRN STREAM SYSTEM AND ANY LOW LEVEL MOISTURE TRANSPORT WILL HAVE TO TAKE A LONG PATH AROUND THE PERIPHERY OF THE SFC RIDGE BEFORE REACHING INTO THE MIDDLE MISSISSIPPI VALLEY. HOWEVER...THE LATEST MODEL RUNS ARE INDICATING MORE MOISTURE AVAILABLE TO THE SYSTEM WITH FORECAST PWATS AROUND 3/4 INCH AND MANY MODELS ARE PAINTING MORE QPF THAN PREVIOUS RUNS. HAVE SOME CONCERN THAT THE MODELS ARE OVER FORECASTING MOISTURE CONTENT AND QPF...SO HAVE GONE WITH A MORE CONSERVATIVE APPROACH TO QPF AMOUNTS THAT WHAT MANY OF THE MODELS WOULD SUGGEST. HOWEVER...STILL FEEL THAT THERE WILL BE ENOUGH DEEP LAYER MOISTURE TO PRODUCE MEASURABLE PCPN ACROSS THE REGION. THE REAL CONCERN WILL BE PCPN TYPE WITH AMOUNTS MORE OF A SECONDARY CONCERN. THIS IS LARGELY BECAUSE THE GUIDANCE IS INDICATING AN INTRUSION OF WARM AIR ABOVE A NEARLY SATURATED...BUT BELOW FREEZING SFC LAYER. THE LATEST RUNS OF THE LOCAL WRFARW...WHICH WAS LARGELY FOLLOWED FOR THE FINER SCALE DETAILS OF THE PCPN TYPE TREND INDICATES A RATHER THICK WARM LAYER WITH MAX TEMPS WITHING THE WARM LAYER OF +3 TO +5C ABOVE A SURFACE BASED INVERSION WITH SFC TEMPERATURES ARND 30F BY THE TIME THE LEADING EDGE OF THE PCPN MOVES INTO THE FAR NWRN PORTIONS OF THE CWA. THE LATEST GUIDANCE SUGGESTS THAT PCPN COULD MOVE INTO THE NWRN PORTIONS OF THE CWA BY ARND 06Z...AND WITH SFC TEMPS OF 30F...BELOW THE DEEP WARM LAYER...PCPN SHOULD LARGELY BE FREEZING RAIN. THE LEADING EDGE OF THE FREEZING RAIN SHOULD STEADILY CROSS THE CWA...REACHING THE CHICAGO METRO AREA DURG THE PREDAWN HOURS. A RATHER STRONG MID LEVEL SHORTWAVE...WITH 700MB OMEGA MAX MOVING ACROSS THE AREA...THERE WILL LIKELY BE A PERIOD OF SLEET MIXING IN WITH THE FREEZING RAIN DURG THE MORNING HOURS. PCPN TYPE BECOME A LITTLE MORE COMPLICATED BY LATE MORNING AND INTO THE AFTERNOON HOURS. MID LEVEL DRY AIR SHOULD MOVE IN RELATIVELY QUICKLY AS THE HEAVIEST BAND OF PCPN TRACKS FROM WEST TO EAST ACROSS THE AREA. THE MID LEVEL DRYING COULD OCCUR BEHIND THE PASSAGE OF THE SFC COLD FRONT. HOWEVER...SINCE THIS SYSTEM IS A MODIFIED PACIFIC SYSTEM...TEMPERATURES SHOULD NOT DROP OFF QUICKLY OR SIGNIFICANTLY FOLLOWING THE FROPA...BUT THERE COULD BE A QUICK BURST OF MODERATE SNOW FOR A SHORT PERIOD WITH THE FROPA AS THE MID LEVEL WARM LAYER ERODES AND THE ENTIRE COLUMN DROPS BELOW FREEZING. LATEST THINKING WITH THAT THE ENTIRE CWA SHOULD SEE A LEAST A LIGHT GLAZING OF FREEZING RAIN...WITH PERHAPS A LIGHT ICE ACCUMULATION OVER THE NORTHERN PORTIONS OF THE CWA...WHERE QPF AND FORCING WILL BE STRONGER. ALSO...IT LOOKS LIKE THE ROCKFORD AREA SHOULD HAVE THE BETTER OPPORTUNITY FOR ACCUMULATING SNOWFALL AS THE THE BEST TIMING FOR A BURST OF HEAVIER SNOW WILL OCCUR EARLIER IN THE DAY...BEFORE SFC TEMPS HAVE A CHANCE TO RISE ABOVE FREEZING. BY THE TIME THAT THE COLD FRONT REACHES THE ERN PORTIONS OF THE CWA...SFC TEMPERATURES MAY WARM ABOVE FREEZING AND THE CHANCES FOR MUCH MEASURABLE SNOWFALL WILL BE LOWER....WITH THE FAR SOUTHERN AND SERN PORTION OF THE CWA...LOCATIONS GENERALLY SOUTH OF THE KANKAKEE RIVER POSSIBLY ONLY SEEING SOME LIGHT FREEZING RAIN BEFORE BRIEFLY CHANGING OVER TO SNOW AND THEN EVENTUALLY CHANGING OVER TO ALL RAIN BY LATE MONDAY MORNING. SO...THE LATEST FORECAST UPDATE WILL INCLUDE MEASURABLE SNOW NORTH OF THE IL/KANKAKEE RIVERS...WITH THE I39 CORRIDOR SEEING AS MUCH A 1 INCH OF TOTAL ACCUMULATION...BEFORE THE WARMER AIR MOVES IN AND MELTS ANY ACCUMULATING SNOW. LOCATIONS NORTH OF THE RIVERS AND EAST OF I-39 SHOULD ONLY SEE AROUND A HALF INCH SO SO OF SNOW. THE GREATEST CONCERN WILL BE IMPACTS ON TRAVEL AS THE FREEZING/FROZEN PCPN WILL BE MOVING ACROSS THE AREA AROUND THE MORNING RUSH HOURS...AND WITH EVEN LIGHT FREEZING RAIN...THERE COULD BE TRAVEL DIFFICULTIES. BY LATE MORNING...SFC TEMPS SHOULD RISE ABOVE FREEZING AND WITH SFC FLOW ONLY VEERING FROM SWLY TO WLY WITH THE FROPA...LITTLE ACTUAL COOLING IS EXPECTED WITH THE FROPA AND TEMPERATURES COULD REACH INTO THE UPPER 30S TO AROUND 40F BY LATE MONDAY AFTERNOON. THE MORE SIGNIFICANT COLD ADVECTION WILL NOT BEGIN UNTIL THE LATE EVENING HOURS AS THE NEXT SFC HIGH BUILDS ACROSS THE NRN PLAINS...SETTING UP NWLY FLOW ACROSS THE REGION AND BY TUESDAY MORNING...TEMPERATURES SHOULD DROP INTO THE MIDDLE TO UPPER 20S. KREIN && .LONG TERM... 427 AM CST TUESDAY THROUGH NEXT SATURDAY... THE EXTENDED FORECAST PERIOD LOOK TO BE GENERALLY QUIET ACROSS THE MIDWEST AS DEEP LOW PRESSURE DEVELOPS OF THE MID ATLANTIC COAST...SLOWING THE PROGRESSION OF THE SFC HIGH ACROSS THE AREA. THE LATEST LONGER RANGE GUIDANCE SUGGESTS THAT THE CENTER OF THE HIGH WILL BE SHUNTED INTO SERN CANADA BY THE DEEP LOW OFF THE EAST COAST...WITH RIDGING EXTENDING THROUGH THE GREAT LAKES AND MIDDLE MISSISSIPPI VALLEY THROUGH MUCH OF THE WEEK. TEMPERATURES SHOULD GENERALLY BE SEASONABLE WITH HIGHS IN THE LOWER TO MIDDLE 30S THROUGH THURSDAY WITH OVERNIGHT LOWS IN THE LOWER TO MIDDLE 20S. PREVAILING HIGH PRESSURE WILL HELP KEEP THE REGION DRY AND NO ADDITIONAL PCPN IS LIKELY THROUGH MUCH OF THE WEEK. THE MODELS CONTINUE TO ADVERTISE A SIGNIFICANT WARMING TREND BY THE END OF THE WEEK. THE MAIN IDEA IS THAT THE DEEP COASTAL LOW AND THE PARENT UPPER LOW WILL REMAIN NEARLY STATIONARY OVER THE MID ATLANTIC COAST...WHILE STRONG UPPER RIDGING BUILDS OVER THE WRN CONUS BY FRIDAY...THE UPPER RIDGE IS EXPECTED TO BUILD OVER THE UPPER MISSISSIPPI VALLEY AND ACROSS THE WRN GREAT LAKES BY NEXT SATURDAY. THE LONGER RANGE TEMPERATURE GUIDANCE IS SUGGESTING THAT TEMPERATURES COULD REACH INTO THE LOWER TO MIDDLE 40S BY FRIDAY AND MIDDLE TO UPPER 40S FOR SATURDAY. HOWEVER...LONGER RANGE TEMPERATURE GUIDANCE TENDS TO TREND A LITTLE CLOSER TO CLIMATOLOGY TOWARD THE END OF THE FORECAST PERIOD...SO THE GOING FORECAST OF MIDDLE TO UPPER 40S FOR NEXT SATURDAY COULD BE ON THE CONSERVATIVE SIDE...AND WITH THE TYPE OF UPPER LEVEL PATTERN EVOLVING...THERE IS THE POTENTIAL THAT TEMPERATURES FOR FRIDAY AND SATURDAY COULD VERY WELL APPROACH OR EXCEED THE 50F MARK. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * SOUTHEAST WINDS AROUND 10 KT TODAY. * BAND OF MIXED PRECIPITATION EXPECTED MONDAY MORNING. MAY START AS -FZRA THEN TURN TO SHORT PERIOD OF SLEET/SNOW. IFR CIGS/VSBY POSSIBLE FOR A FEW HOUR PERIOD. MDB //DISCUSSION...UPDATED 12Z... HIGH PRESSURE RIDGING IS ACROSS THE AREA THIS MORNING BUT WILL BE SHIFTING TO THE EAST. THIS WILL RESULT IN STEADY SOUTHEAST WINDS THROUGH THE DAY WITH VFR CONDITIONS. LOW PRESSURE WILL MOVE ACROSS THE AREA MONDAY MORNING BRINGING A PERIOD OF MIXED PRECIPITATION WITH IT. A FEW HOUR PERIOD IS EXPECTED TO BEGIN TOWARD 09Z OUT NEAR RFD AND TOWARD 11Z IN THE CHICAGO AREA. THE DETAILS REMAIN IN FLUX BUT THE LATEST THINKING IS THAT PRECIPITATION WILL START OUT AS A SHORT PERIOD OF FREEZING RAIN THEN TRANSITION TO A MIX OF SLEET AND SNOW FOR A 1-3 HOUR PERIOD. FORCING IS STRONG FOR A SHORT TIME SO IT IS POSSIBLE THAT A PERIOD OF MODERATE SNOW OCCURS LEADING TO SOME SLUSHY ACCUMULATION. PRECIPITATION WILL INITIALLY BE FIGHTING A LAYER OF DRY AIR SO ONSET COULD BE DELAYED AND THIS MAY ALSO AFFECT THE PROGRESSION OF PRECIP TYPES. PRECIP INTENSITY WILL QUICKLY DIMINISH MID TO LATE MORNING MONDAY WITH LIGHT RAIN OR DRIZZLE POSSIBLE AS TEMPERATURES WARM ABOVE FREEZING. A PERIOD OF IFR CIGS IS EXPECTED PROVIDED DECENT PRECIP OCCURS AND IFR VSBY WOULD BE LIKELY IF A SHORT PERIOD OF MAINLY SNOW CAN OCCUR. BE SURE TO CHECK BACK FOR FURTHER UPDATES... MDB //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE IN WIND TRENDS. * MEDIUM-HIGH CONFIDENCE IN A BAND OF MIXED PRECIPITATION OCCURRING MONDAY MORNING. MEDIUM CONFIDENCE IN PROGRESSION OF PRECIP TYPE AND TIMING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR. NW WINDS. TUESDAY...VFR. NW WINDS BECOMING N. WEDNESDAY...VFR. N WINDS. THURSDAY...VFR. S WINDS. FRIDAY...VFR. S WINDS. SATURDAY...VFR. S WINDS. MDB && .MARINE... 251 AM CST HIGH PRESSURE IS CENTERED OVER EASTERN ONTARIO EARLY THIS MORNING WITH A RIDGE AXIS EXTENDING ACROSS LAKE MICHIGAN. THIS HAS ALLOWED WINDS TO EASE AND TURN EAST TO NORTHEAST AND WILL ALLOW FOR A SHIFT TO SOUTHEAST THROUGH THE MORNING. WILL ALLOW THE SMALL CRAFT ADVISORY TO EXPIRE AS WINDS CONTINUE TO EASE ALLOWING WAVES TO BE ON A DOWNWARD TREND. WILL CONTINUE WITH A 3-5 OCCASIONAL 7 FT FORECAST. LOW PRESSURE IS OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA AND WILL BE MOVING EAST ALONG THE CANADIAN BORDER REACHING LAKE SUPERIOR BY MIDDAY MONDAY. WITH THE HIGH PRESSURE RATHER STRONG THE PRESSURE GRADIENT BETWEEN IT AND THE LOW WILL BE TIGHTENING THROUGH THE DAY DESPITE THE LOW NOT BEING TERRIBLY DEEP. AS A RESULT WIND SPEEDS WILL STEADILY INCREASE TO ABOUT 30 KT ACROSS MOST OF THE LAKE THIS EVENING WITH SOME 35 KT GALE FORCE GUSTS POSSIBLE ACROSS CENTRAL AND NORTHERN SECTIONS OVERNIGHT INTO EARLY MONDAY MORNING AS WINDS TURN MORE SOUTHERLY. WILL ISSUE A SMALL CRAFT ADVISORY FOR MOST OF THE ILLINOIS NEARSHORE FROM EARLY THIS EVENING THROUGH LATE MONDAY MORNING AS WINDS AND WAVES COME UP. WINDS WILL THEN TURN SOUTHWESTERLY MONDAY AFTERNOON AS THE LOW TRACKS TO THE EAST WITH A SHIFT TO NORTHWEST MONDAY EVENING. COLDER AIR WILL SPREAD IN ON A FAIRLY STRONG HIGH THAT WILL MOVE INTO THE MID AND UPPER MISSISSIPPI RIVER VALLEY TUESDAY WHICH WILL ALLOW NORTHWEST WINDS TO INCREASE EARLY TUESDAY MORNING AND TURN NORTH THROUGH THE DAY. SPEEDS WILL THEN EASE INTO TUESDAY NIGHT AS THE HIGH MOVES CLOSER THEN SPREADS ACROSS THE LAKE LATER WEDNESDAY. THE HIGH WILL BE SLOW TO SHIFT TO THE EAST BUT WINDS WILL TURN WESTERLY AS IT DOES THURSDAY THEN SOUTHWESTERLY THURSDAY NIGHT. STEADY SOUTHWEST WINDS ARE THEN EXPECTED INTO THE WEEKEND AS THE HIGH SLOWLY MOVES OFF TO THE EAST. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...6 PM SUNDAY TO 10 AM MONDAY. && $$ 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 554 AM CST Sun Dec 7 2014 .SHORT TERM...(Today) ISSUED AT 331 AM CST SUN DEC 7 2014 Clouds have cleared out to the south tonight for now, but they are lingering very close-by. Satellite images already confirm increasing high clouds from the west. The HRRR is advertising a return of low clouds from the east-southeast across the eastern half of the area between 15z/9am and 18z/Noon today, but that seems a bit aggressive based on the current progression of clouds across Indiana and the expected wind patterns this morning. Have increased clouds from the west based on satellite and model consensus, but only trended minor increases in clouds across the east during the day for now. Will monitor the movement of low clouds toward our eastern counties for potential sky cover updates in the short term. Northeast flow early this morning is expected to evolve to east and then southeast this afternoon, as high pressure centered over the Lake Michigan departs farther east across the Great Lakes. The onset of southeast winds will increase the potential return of low clouds currently lingering across southern IL. Temperatures today will only climb about 12-13F above morning lows due to increasing clouds, with highs topping out in the upper 30s to low 40s. && .LONG TERM...(Tonight through Saturday) ISSUED AT 331 AM CST SUN DEC 7 2014 High pressure continues to build into the region, although clouds continue to dominate the Midwest. Plenty of moisture on sat imagery obscuring the llvl clouds underneath. Clearing in patches certainly not anticipated for long as llvl moisture remains trapped by continuing strong inversion over the area. The dry air aloft is not coincident with enough turbulence to break up the inversion and erode the higher RH at roughly 925 mb. This dry air will also be the first issue for eroding the approaching precip late Sun night and into Monday. Models maintaining consistency with the last two runs and continuity with one another with regards to approach and qpf after midnight tonight and into Monday. A quick front moving through the area bringing precip after midnight and through the day Monday so far looks like mostly rain, though the nrn tier of the state may see a bit more of a rain/snow/wintry mix. Concern remains whether or not the models are too quick to overcome the dry air aloft or whether or not the precip may be delayed slightly. Beyond Monday`s cold front, temps cool briefly, then moderate back into the 40s for highs through the end of the week. 00z GFS agreeing with yesterdays 00z ECMWF and backing down from the precip Wed/Thursday, instead dominating the sfc map with high pressure. Pops mid week have been removed. Deepening low over the northeast/east coast causing a bit of a back up across the CONUS as it is slow to move and the models having some issue with pushing the new wave inland on the Pacific coast and managing the ridging in the middle. Seems from Friday and into the weekend the forecast becomes a bit more problematic in the details as the models work out a pattern shift again. && .AVIATION...(For the 12Z TAFS through 12Z Monday morning) ISSUED AT 554 AM CST SUN DEC 7 2014 High pressure centered over lower Michigan and extending SW into IL will slide east today. That movement will cause our surface winds to shift from NE to SE by this afternoon, while increasing to 10-14kt. High clouds will blanket the entire state today, with low clouds lurking just south of our forecast area already at 12z/6am. As winds shift to SE, that cloud mass will eventually gain momentum toward the terminal sites. HRRR indicates that SPI and DEC will have the higher potential of seeing a return of MVFR clouds after 22z/4pm, with the clouds eventually advancing all the way north to PIA/BMI/CMI during the evening. The initial push of moisture may have breaks in the ceiling per the latest HRRR, so we delayed the persistent low clouds until later evening when light rain will begin to develop from NW to SE ahead of an approaching warm front and low pressure system. While any light rain could change to freezing rain late in this TAF period, we did not include FZRA with this issuance. We only mentioned VCSH after midnight for now. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Shimon LONG TERM...HJS AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
430 AM CST SUN DEC 7 2014 .SHORT TERM... 427 AM CST A HIGH AMPLITUDE...PROGRESSIVE UPPER LEVEL PATTERN WILL BRING VERY CHANGEABLE WEATHER TO THE REGION FOR THE NEXT SEVERAL DAYS...THOUGH THE MAIN CONCERN WILL BE A WINTRY MIXED PCPN EVENT FOR SUNDAY NIGHT INTO MONDAY MORNING. THROUGH MONDAY NIGHT... FOR THE REMAINDER OF THE NIGHT AND INTO SUNDAY MORNING...CONDITIONS WILL REMAIN QUIET WITH INCREASING HIGH CLOUD COVER WHICH WILL LIMIT ANY FURTHER RADIATIVE COOLING AND TEMPERATURES ACROSS THE REGION SHOULD BOTTOM OUT IN THE LOWER TO MIDDLE 20S...EXCEPT FOR DOWNTOWN CHICAGO WHICH WILL ONLY DROP TO AROUND 30F. THE REMAINDER OF SUNDAY SHOULD BE RELATIVELY INNOCUOUS WITH CONTINUED INCREASING MID AND HIGH LEVEL CLOUD COVER. AS THE CENTER OF A LARGE AREA OF HIGH PRESSURE SHIFTS FROM THE UPPER GREAT LAKES TO ERN CANADA...A LOW PRESSURE SYSTEM WILL MOVE OUT OF THE SRN CANADIAN ROCKIES...DRAGGING A WEAK COLD FRONT INTO THE PLAINS. LOW LEVEL FLOW WILL BECOME MORE SELY AHEAD OF THE APPROACHING SYSTEM...THOUGH WITH HIGH PRESSURE RIDGING STILL NOSING SOUTHWEST INTO THE LOWER MISSISSIPPI VALLEY...EVEN AS TEMPERATURES RISE INTO UPPER 30S...DEWPOINTS WILL REMAIN RELATIVELY LOW...REMAINING IN THE LOW 20S. AS THE SYSTEM APPROACHES THE REGION...CONCERNS WILL BECOME PCPN TYPE AND AMOUNT WITH THE SYSTEM. PREVIOUS MODEL RUNS HAD MAINTAINED A RELATIVELY DRY ENVIRONMENT AS THE GULF OF MEXICO REMAIN CUT OFF FROM THE NRN STREAM SYSTEM AND ANY LOW LEVEL MOISTURE TRANSPORT WILL HAVE TO TAKE A LONG PATH AROUND THE PERIPHERY OF THE SFC RIDGE BEFORE REACHING INTO THE MIDDLE MISSISSIPPI VALLEY. HOWEVER...THE LATEST MODEL RUNS ARE INDICATING MORE MOISTURE AVAILABLE TO THE SYSTEM WITH FORECAST PWATS AROUND 3/4 INCH AND MANY MODELS ARE PAINTING MORE QPF THAN PREVIOUS RUNS. HAVE SOME CONCERN THAT THE MODELS ARE OVER FORECASTING MOISTURE CONTENT AND QPF...SO HAVE GONE WITH A MORE CONSERVATIVE APPROACH TO QPF AMOUNTS THAT WHAT MANY OF THE MODELS WOULD SUGGEST. HOWEVER...STILL FEEL THAT THERE WILL BE ENOUGH DEEP LAYER MOISTURE TO PRODUCE MEASURABLE PCPN ACROSS THE REGION. THE REAL CONCERN WILL BE PCPN TYPE WITH AMOUNTS MORE OF A SECONDARY CONCERN. THIS IS LARGELY BECAUSE THE GUIDANCE IS INDICATING AN INTRUSION OF WARM AIR ABOVE A NEARLY SATURATED...BUT BELOW FREEZING SFC LAYER. THE LATEST RUNS OF THE LOCAL WRFARW...WHICH WAS LARGELY FOLLOWED FOR THE FINER SCALE DETAILS OF THE PCPN TYPE TREND INDICATES A RATHER THICK WARM LAYER WITH MAX TEMPS WITHING THE WARM LAYER OF +3 TO +5C ABOVE A SURFACE BASED INVERSION WITH SFC TEMPERATURES ARND 30F BY THE TIME THE LEADING EDGE OF THE PCPN MOVES INTO THE FAR NWRN PORTIONS OF THE CWA. THE LATEST GUIDANCE SUGGESTS THAT PCPN COULD MOVE INTO THE NWRN PORTIONS OF THE CWA BY ARND 06Z...AND WITH SFC TEMPS OF 30F...BELOW THE DEEP WARM LAYER...PCPN SHOULD LARGELY BE FREEZING RAIN. THE LEADING EDGE OF THE FREEZING RAIN SHOULD STEADILY CROSS THE CWA...REACHING THE CHICAGO METRO AREA DURG THE PREDAWN HOURS. A RATHER STRONG MID LEVEL SHORTWAVE...WITH 700MB OMEGA MAX MOVING ACROSS THE AREA...THERE WILL LIKELY BE A PERIOD OF SLEET MIXING IN WITH THE FREEZING RAIN DURG THE MORNING HOURS. PCPN TYPE BECOME A LITTLE MORE COMPLICATED BY LATE MORNING AND INTO THE AFTERNOON HOURS. MID LEVEL DRY AIR SHOULD MOVE IN RELATIVELY QUICKLY AS THE HEAVIEST BAND OF PCPN TRACKS FROM WEST TO EAST ACROSS THE AREA. THE MID LEVEL DRYING COULD OCCUR BEHIND THE PASSAGE OF THE SFC COLD FRONT. HOWEVER...SINCE THIS SYSTEM IS A MODIFIED PACIFIC SYSTEM...TEMPERATURES SHOULD NOT DROP OFF QUICKLY OR SIGNIFICANTLY FOLLOWING THE FROPA...BUT THERE COULD BE A QUICK BURST OF MODERATE SNOW FOR A SHORT PERIOD WITH THE FROPA AS THE MID LEVEL WARM LAYER ERODES AND THE ENTIRE COLUMN DROPS BELOW FREEZING. LATEST THINKING WITH THAT THE ENTIRE CWA SHOULD SEE A LEAST A LIGHT GLAZING OF FREEZING RAIN...WITH PERHAPS A LIGHT ICE ACCUMULATION OVER THE NORTHERN PORTIONS OF THE CWA...WHERE QPF AND FORCING WILL BE STRONGER. ALSO...IT LOOKS LIKE THE ROCKFORD AREA SHOULD HAVE THE BETTER OPPORTUNITY FOR ACCUMULATING SNOWFALL AS THE THE BEST TIMING FOR A BURST OF HEAVIER SNOW WILL OCCUR EARLIER IN THE DAY...BEFORE SFC TEMPS HAVE A CHANCE TO RISE ABOVE FREEZING. BY THE TIME THAT THE COLD FRONT REACHES THE ERN PORTIONS OF THE CWA...SFC TEMPERATURES MAY WARM ABOVE FREEZING AND THE CHANCES FOR MUCH MEASURABLE SNOWFALL WILL BE LOWER....WITH THE FAR SOUTHERN AND SERN PORTION OF THE CWA...LOCATIONS GENERALLY SOUTH OF THE KANKAKEE RIVER POSSIBLY ONLY SEEING SOME LIGHT FREEZING RAIN BEFORE BRIEFLY CHANGING OVER TO SNOW AND THEN EVENTUALLY CHANGING OVER TO ALL RAIN BY LATE MONDAY MORNING. SO...THE LATEST FORECAST UPDATE WILL INCLUDE MEASURABLE SNOW NORTH OF THE IL/KANKAKEE RIVERS...WITH THE I39 CORRIDOR SEEING AS MUCH A 1 INCH OF TOTAL ACCUMULATION...BEFORE THE WARMER AIR MOVES IN AND MELTS ANY ACCUMULATING SNOW. LOCATIONS NORTH OF THE RIVERS AND EAST OF I-39 SHOULD ONLY SEE AROUND A HALF INCH SO SO OF SNOW. THE GREATEST CONCERN WILL BE IMPACTS ON TRAVEL AS THE FREEZING/FROZEN PCPN WILL BE MOVING ACROSS THE AREA AROUND THE MORNING RUSH HOURS...AND WITH EVEN LIGHT FREEZING RAIN...THERE COULD BE TRAVEL DIFFICULTIES. BY LATE MORNING...SFC TEMPS SHOULD RISE ABOVE FREEZING AND WITH SFC FLOW ONLY VEERING FROM SWLY TO WLY WITH THE FROPA...LITTLE ACTUAL COOLING IS EXPECTED WITH THE FROPA AND TEMPERATURES COULD REACH INTO THE UPPER 30S TO AROUND 40F BY LATE MONDAY AFTERNOON. THE MORE SIGNIFICANT COLD ADVECTION WILL NOT BEGIN UNTIL THE LATE EVENING HOURS AS THE NEXT SFC HIGH BUILDS ACROSS THE NRN PLAINS...SETTING UP NWLY FLOW ACROSS THE REGION AND BY TUESDAY MORNING...TEMPERATURES SHOULD DROP INTO THE MIDDLE TO UPPER 20S. KREIN && .LONGER TERM... 427 AM CST TUESDAY THROUGH NEXT SATURDAY... THE EXTENDED FORECAST PERIOD LOOK TO BE GENERALLY QUIET ACROSS THE MIDWEST AS DEEP LOW PRESSURE DEVELOPS OF THE MID ATLANTIC COAST...SLOWING THE PROGRESSION OF THE SFC HIGH ACROSS THE AREA. THE LATEST LONGER RANGE GUIDANCE SUGGESTS THAT THE CENTER OF THE HIGH WILL BE SHUNTED INTO SERN CANADA BY THE DEEP LOW OFF THE EAST COAST...WITH RIDGING EXTENDING THROUGH THE GREAT LAKES AND MIDDLE MISSISSIPPI VALLEY THROUGH MUCH OF THE WEEK. TEMPERATURES SHOULD GENERALLY BE SEASONABLE WITH HIGHS IN THE LOWER TO MIDDLE 30S THROUGH THURSDAY WITH OVERNIGHT LOWS IN THE LOWER TO MIDDLE 20S. PREVAILING HIGH PRESSURE WILL HELP KEEP THE REGION DRY AND NO ADDITIONAL PCPN IS LIKELY THROUGH MUCH OF THE WEEK. THE MODELS CONTINUE TO ADVERTISE A SIGNIFICANT WARMING TREND BY THE END OF THE WEEK. THE MAIN IDEA IS THAT THE DEEP COASTAL LOW AND THE PARENT UPPER LOW WILL REMAIN NEARLY STATIONARY OVER THE MID ATLANTIC COAST...WHILE STRONG UPPER RIDGING BUILDS OVER THE WRN CONUS BY FRIDAY...THE UPPER RIDGE IS EXPECTED TO BUILD OVER THE UPPER MISSISSIPPI VALLEY AND ACROSS THE WRN GREAT LAKES BY NEXT SATURDAY. THE LONGER RANGE TEMPERATURE GUIDANCE IS SUGGESTING THAT TEMPERATURES COULD REACH INTO THE LOWER TO MIDDLE 40S BY FRIDAY AND MIDDLE TO UPPER 40S FOR SATURDAY. HOWEVER...LONGER RANGE TEMPERATURE GUIDANCE TENDS TO TREND A LITTLE CLOSER TO CLIMATOLOGY TOWARD THE END OF THE FORECAST PERIOD...SO THE GOING FORECAST OF MIDDLE TO UPPER 40S FOR NEXT SATURDAY COULD BE ON THE CONSERVATIVE SIDE...AND WITH THE TYPE OF UPPER LEVEL PATTERN EVOLVING...THERE IS THE POTENTIAL THAT TEMPERATURES FOR FRIDAY AND SATURDAY COULD VERY WELL APPROACH OR EXCEED THE 50F MARK. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * SOUTHEAST WINDS AROUND 10 KT TODAY. * LOWERING CIGS AND A PERIOD OF MIXED PRECIPITATION STARTING AROUND OR JUST AFTER 12Z MONDAY. MDB //DISCUSSION...UPDATED 06Z... HIGH PRESSURE IS OVERHEAD OF THE TERMINALS TONIGHT ALLOWING FOR LIGHT NORTHEAST WINDS. WINDS WILL SWING AROUND TO THE SOUTHEAST OVERNIGHT AND BE FAIRLY STEADY AROUND 10 KT DURING THE DAY. WINDS WILL TURN TO THE SOUTH INTO MONDAY MORNING. VFR HIGH CLOUDS WILL STREAM OVERHEAD THROUGH THE DAY TODAY AND TONIGHT BEFORE LOWERING INTO MONDAY MORNING AHEAD OF A LOW PRESSURE SYSTEM/COLD FRONT. A PERIOD OF MIXED PRECIPITATION IS EXPECTED MONDAY MORNING...LIKELY STARTING JUST PRIOR TO 12Z AT RFD AND AROUND OR SOON AFTER 12Z AT DPA/ORD/MDW/GYY. DETAILS ARE STILL IN FLUX BUT SOME SNOW/SLEET ACCUMULATION IS POSSIBLE WITH A PERIOD OF IFR CIGS/VSBY POSSIBLE. MDB //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH CONFIDENCE IN SOUTHEAST WINDS AROUND 10 KT TODAY. * HIGH CONFIDENCE IN LOWERING CIGS AND A PERIOD OF MIXED PRECIPITATION MONDAY MORNING. MDB //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...CHANCE OF SLEET/SNOW MIX IN THE MORNING. MVFR/BRIEF IFR POSSIBLE. S WINDS BECOMING W. TUESDAY...VFR. NW WINDS BECOMING N. WEDNESDAY...VFR. N WINDS BECOMING NE. THURSDAY...VFR. S WINDS. FRIDAY...VFR. S WINDS. RATZER && .MARINE... 251 AM CST HIGH PRESSURE IS CENTERED OVER EASTERN ONTARIO EARLY THIS MORNING WITH A RIDGE AXIS EXTENDING ACROSS LAKE MICHIGAN. THIS HAS ALLOWED WINDS TO EASE AND TURN EAST TO NORTHEAST AND WILL ALLOW FOR A SHIFT TO SOUTHEAST THROUGH THE MORNING. WILL ALLOW THE SMALL CRAFT ADVISORY TO EXPIRE AS WINDS CONTINUE TO EASE ALLOWING WAVES TO BE ON A DOWNWARD TREND. WILL CONTINUE WITH A 3-5 OCCASIONAL 7 FT FORECAST. LOW PRESSURE IS OVER SOUTHERN SASKATCHEWAN AND EASTERN MONTANA AND WILL BE MOVING EAST ALONG THE CANADIAN BORDER REACHING LAKE SUPERIOR BY MIDDAY MONDAY. WITH THE HIGH PRESSURE RATHER STRONG THE PRESSURE GRADIENT BETWEEN IT AND THE LOW WILL BE TIGHTENING THROUGH THE DAY DESPITE THE LOW NOT BEING TERRIBLY DEEP. AS A RESULT WIND SPEEDS WILL STEADILY INCREASE TO ABOUT 30 KT ACROSS MOST OF THE LAKE THIS EVENING WITH SOME 35 KT GALE FORCE GUSTS POSSIBLE ACROSS CENTRAL AND NORTHERN SECTIONS OVERNIGHT INTO EARLY MONDAY MORNING AS WINDS TURN MORE SOUTHERLY. WILL ISSUE A SMALL CRAFT ADVISORY FOR MOST OF THE ILLINOIS NEARSHORE FROM EARLY THIS EVENING THROUGH LATE MONDAY MORNING AS WINDS AND WAVES COME UP. WINDS WILL THEN TURN SOUTHWESTERLY MONDAY AFTERNOON AS THE LOW TRACKS TO THE EAST WITH A SHIFT TO NORTHWEST MONDAY EVENING. COLDER AIR WILL SPREAD IN ON A FAIRLY STRONG HIGH THAT WILL MOVE INTO THE MID AND UPPER MISSISSIPPI RIVER VALLEY TUESDAY WHICH WILL ALLOW NORTHWEST WINDS TO INCREASE EARLY TUESDAY MORNING AND TURN NORTH THROUGH THE DAY. SPEEDS WILL THEN EASE INTO TUESDAY NIGHT AS THE HIGH MOVES CLOSER THEN SPREADS ACROSS THE LAKE LATER WEDNESDAY. THE HIGH WILL BE SLOW TO SHIFT TO THE EAST BUT WINDS WILL TURN WESTERLY AS IT DOES THURSDAY THEN SOUTHWESTERLY THURSDAY NIGHT. STEADY SOUTHWEST WINDS ARE THEN EXPECTED INTO THE WEEKEND AS THE HIGH SLOWLY MOVES OFF TO THE EAST. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741...6 PM SUNDAY TO 10 AM MONDAY. && $$ 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 332 AM CST Sun Dec 7 2014 .SHORT TERM...(Today) ISSUED AT 331 AM CST SUN DEC 7 2014 Clouds have cleared out to the south tonight for now, but they are lingering very close-by. Satellite images already confirm increasing high clouds from the west. The HRRR is advertising a return of low clouds from the east-southeast across the eastern half of the area between 15z/9am and 18z/Noon today, but that seems a bit aggressive based on the current progression of clouds across Indiana and the expected wind patterns this morning. Have increased clouds from the west based on satellite and model consensus, but only trended minor increases in clouds across the east during the day for now. Will monitor the movement of low clouds toward our eastern counties for potential sky cover updates in the short term. Northeast flow early this morning is expected to evolve to east and then southeast this afternoon, as high pressure centered over the Lake Michigan departs farther east across the Great Lakes. The onset of southeast winds will increase the potential return of low clouds currently lingering across southern IL. Temperatures today will only climb about 12-13F above morning lows due to increasing clouds, with highs topping out in the upper 30s to low 40s. && .LONG TERM...(Tonight through Saturday) ISSUED AT 331 AM CST SUN DEC 7 2014 High pressure continues to build into the region, although clouds continue to dominate the Midwest. Plenty of moisture on sat imagery obscuring the llvl clouds underneath. Clearing in patches certainly not anticipated for long as llvl moisture remains trapped by continuing strong inversion over the area. The dry air aloft is not coincident with enough turbulence to break up the inversion and erode the higher RH at roughly 925 mb. This dry air will also be the first issue for eroding the approaching precip late Sun night and into Monday. Models maintaining consistency with the last two runs and continuity with one another with regards to approach and qpf after midnight tonight and into Monday. A quick front moving through the area bringing precip after midnight and through the day Monday so far looks like mostly rain, though the nrn tier of the state may see a bit more of a rain/snow/wintry mix. Concern remains whether or not the models are too quick to overcome the dry air aloft or whether or not the precip may be delayed slightly. Beyond Monday`s cold front, temps cool briefly, then moderate back into the 40s for highs through the end of the week. 00z GFS agreeing with yesterdays 00z ECMWF and backing down from the precip Wed/Thursday, instead dominating the sfc map with high pressure. Pops mid week have been removed. Deepening low over the northeast/east coast causing a bit of a back up across the CONUS as it is slow to move and the models having some issue with pushing the new wave inland on the Pacific coast and managing the ridging in the middle. Seems from Friday and into the weekend the forecast becomes a bit more problematic in the details as the models work out a pattern shift again. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) ISSUED AT 1122 PM CST SAT DEC 6 2014 VFR CONDITIONS SHOULD PREVAIL OVER THE TAF SITES THROUGH THE PERIOD...WITH A SLIGHT EXCEPTION FOR SPI AS HAZE STILL LINGERS REDUCING VIS TO MVFR. HOWEVER...DO NOT THINK THIS WILL STICK AROUND VERY LONG SINCE UPSTREAM AT AAA VIS HAS ALREADY CLEARED OUT ABOVE 6SM FROM THE HIGH PRESSURE BUILDING OVER THE GREAT LAKES. THEREFORE...USED A TEMPO GROUP FOR THE NEXT HOUR TO ACCOUNT FOR THE REDUCED VIS IMPROVING TO VFR WITHIN THE HOUR. OTHERWISE...HIGH CLOUDS ARE MOVING IN OVER THE TAF SITES WITH THE NEXT STORM SYSTEM OUT IN THE PLAINS. ALONG WITH HIGH CLOUDS STREAMING IN...WINDS SHOULD BEGIN TO SHIFT TO THE EAST AND THEN SOUTHEAST BY TOMORROW. CIGS APPEAR TO REMAIN VFR THROUGH THE TAF PERIOD ACCORDING TO GUIDANCE AND SOUNDINGS. PIA...BMI...AND SPI COULD SEE VCSH TOMORROW NIGHT AROUND 03Z/04Z...BUT NOT CONFIDENT ENOUGH IN RAIN FALLING OVER THE SITES BEFORE 06Z TO INCLUDE ANYTHING ELSE. THIS CAN BE UPDATED IN LATER TAF ISSUANCES IF NEEDED. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Shimon LONG TERM...HJS AVIATION...ALW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1149 PM CST SAT DEC 6 2014 .SHORT TERM... 257 PM CST NORTHEAST FLOW OVER THE REGION AHEAD OF HIGH PRESSURE HAS CONTINUED TO EASE IN DRIER AIR. MID-AFTERNOON VISIBLE SATELLITE IMAGERY REVEALS ONLY SOME DEPARTING STRATUS ACROSS THE FAR SOUTHERN FORECAST AREA...AND SOME REMAINING RIBBONS OF LAKE EFFECT CLOUDS INTO FAR NORTHEAST IL AND NORTHWEST IN. WATER VAPOR IMAGERY CONFIRMS DRIER MID-LEVEL AIR AND SUPPRESSION MOVING OVERHEAD WHICH SHOULD MITIGATE CLOUDS THIS EVENING...OUTSIDE OF A FEW LAKE EFFECT CLOUDS INCHING WESTWARD OVER NORTHERN IL WITHIN THE VEERING FLOW. A LIGHT WIND COMPONENT WILL REMAIN THIS EVENING ALTHOUGH AS THE 1039 MB HIGH PASSES ACROSS WI...THE WINDS WILL LIKELY BECOME LIGHT AND VARIABLE ALLOWING FOR FURTHER TEMPERATURE DROP. DEW POINTS ARE SEVERAL DEGREES ABOVE THIS AT PRESENT...BUT NOT REALLY A PATTERN WHERE WOULD EXPECT FOG...ESPECIALLY ANYTHING OF NOTE. SOUTHEAST WINDS WILL SETTLE IN ON SUNDAY WITH THE DEPARTING HIGH AND LOW PRESSURE MARCHING EASTWARD NEAR THE NORTHERN CONUS BORDER. HIGH CLOUDS LOOK TO GRADUALLY INCREASE/THICKEN DURING THE AFTERNOON. GIVEN HIGHS TODAY REACHED THE UPPER 30S TO LOWER 40S WOULD ENVISION SUNDAY BEING IN THE SAME ARENA IF CLOUDS DO NOT THICKEN EARLIER THAN FORECAST. MTF && .LONG TERM... 315 PM CST LONG TERM...SUNDAY NIGHT THROUGH SATURDAY... OVERALL THE EXTENDED PERIOD WILL CONTINUE TO FEATURE A FAIRLY PROGRESSIVE WEATHER PATTERN...WITH ONLY A QUICK HIT OF SOME COLDER AIR FOR LATE TUESDAY INTO WEDNESDAY. THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE INCREASING POTENTIAL OF A QUICK HIT OF WINTERY WEATHER LATE SUNDAY NIGHT INTO MONDAY MORNING. WATER VAPOR IMAGERY INDICATES THE NEXT PACIFIC SYSTEM OF INTEREST...NOW SHIFTING ONSHORE ACROSS WASHINGTON STATE. THIS FEATURE...ALONG WITH AN ASSOCIATED AREA OF LOW PRESSURE IS EXPECTED TO TRACK QUICKLY ALONG OR NEAR THE CANADIAN INTERNATIONAL BORDER SUNDAY THROUGH TUESDAY. TYPICALLY THIS TYPE OF TRACK IS NOT GOOD FOR MUCH PRECIPITATION FOR THE AREA...AND OVERALL THIS WILL BE THE CASE. HOWEVER...IT APPEARS THAT QUICK HIT OF WINTRY PRECIPITATION IS LIKELY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. A PERIOD OF INCREASING ISENTROPIC ASCENT COMBINED WITH SOME DECENT Q-VECTOR CONVERGENCE...ASSOCIATED WITH ADDITIONAL SHORTWAVE ENERGY DIGGING SOUTHEASTWARD TOWARDS THAT AREA LATER SUNDAY NIGHT...SHOULD PROVIDE A SHORT PERIOD OF FORCING SUPPORTIVE OF PRECIPITATION ACROSS NORTHERN ILLINOIS/NORTHWESTERN INDIANA. OVERALL...THIS STILL APPEARS TO BE A SMALL EVENT FOR THE AREA. HOWEVER...IT APPEARS THAT A STRENGTHENING BAROCLINIC ZONE ALONG AN OCCLUDED FRONTAL BOUNDARY MAY PROVIDE A SHORT PERIOD OF ENHANCED MESOSCALE FORCING...SUPPORTIVE A SHORT PERIOD OF HEAVIER PRECIPITATION...ESPECIALLY GIVEN THE PRESENCE OF STEEP MID LEVEL LAPSE RATES INTO MONDAY MORNING. THUS...IT APPEARS THAT BAND OF PRECIPITATION...POSSIBLY ONLY LASTING A COUPLE HOURS AT ANY GIVEN LOCATION...IS LIKELY TO MOVE ACROSS THE AREA IN TIME FOR THE MONDAY MORNING RUSH. PRECIP TYPE STILL APPEARS TO BE TRICKY WITH THIS ACTIVITY EARLY MONDAY. ASIDE FOR THE NAM SOLUTION...MOST MODEL DERIVED SOUNDINGS ACROSS NORTHERN ILLINOIS INDICATE MAX LAYER TEMPERATURES OF ONLY +1 TO +1.5 DEGREES CELSIUS...WHICH WOULD SUGGEST ONLY PARTIAL MELTING OF DENDRITES...POSSIBLY RESULTING IN SNOW AND SLEET PRECIP TYPES ACROSS MOST OF FAR NORTHERN ILLINOIS. ALSO...GIVEN THAT THERE COULD BE SOME ENHANCE PRECIP RATES WITH THIS ACTIVITY...AS WELL AS THE FACT THAT EVAPORATIVE COOLING POTENTIAL SUNDAY NIGHT WILL BE HIGH...IT APPEARS PRUDENT TO MENTION MORE OF A SNOW AND SLEET SCENARIO ACROSS FAR NORTHERN ILLINOIS RATHER THAN FREEZING RAIN AT THIS POINT. THEREFORE...I HAVE TRENDED THE FORECAST IN THIS DIRECTION. ACCUMULATIONS ARE ALSO POSSIBLE WITH THIS ACTIVITY. IN FACT...SOME AREAS COULD GET A QUICK INCH OF SNOW...IF IT FALLS PRIMARILY AS SUCH. AT THIS TIME IT APPEARS THE BEST POTENTIAL FOR THIS APPEARS TO BE ROUGHLY ALONG AND NORTH OF I-88 IN NORTHERN ILLINOIS. ALTHOUGH TOTAL AMOUNTS WILL BE LIGHT...THE POSSIBILITY OF A QUICK HALF TO ONE INCH OF SNOW RIGHT AROUND DAYBREAK MONDAY COULD CAUSE PROBLEMS FOR THE MONDAY MORNING COMMUTE. AREAS SOUTH OF INTERSTATE 80 COULD SEE MORE OF MIX BAG OF RAIN...FREEZING RAIN...SLEET AND SNOW GIVEN SLIGHTLY WARMER MID LEVEL TEMPERATURES. SURFACE TEMPERATURES HERE MAY BE HOVERING RIGHT AROUND FREEZING...SO QUESTIONS STILL RESIDE AROUND HOW MUCH OF THIS PRECIP WILL BE FROZEN. ONCE THIS BAND OF HEAVER PRECIP SHIFTS EAST OF THE AREA BY LATE MORNING...IT APPEARS THAT THE MID LEVELS WILL DRY OUT SUBSTANTIALLY...THUS ANY LINGERING PRECIP MONDAY AFTERNOON WOULD LIKELY BE MORE DRIZZLY. THE COLDER SIDE OF THE STORM SYSTEM WILL ARRIVE ACROSS THE REGION BY EARLY MONDAY EVENING...AS WINDS BECOME A BIT GUSTY OUT OF THE WEST NORTHWEST. THIS SHOULD RESULT IN A COLDER DAY ACROSS THE AREA ON TUESDAY. MOST AREAS WILL REMAIN DRY TUESDAY AND TUESDAY NIGHT. HOWEVER...SOME LAKE EFFECT SNOW SHOWERS OR FLURRIES ARE POSSIBLE ACROSS NORTHWESTERN INDIANA DURING THE DAY TUESDAY. THEN AS THE LOWER LEVEL FLOW VEERS MORE NORTHERLY LATE TUESDAY THESE LAKE EFFECT FLURRIES COULD GET INTO NORTHEASTERN ILLINOIS TUESDAY EVENING. OVERALL...THIS DOES NOT APPEAR TO BE MUCH OF A LAKE EFFECT EVENT AS LAKE INDUCED INVERSION HEIGHTS DO NOT APPEAR VERY IMPRESSIVE...AND EVEN APPEAR TO REMAIN BELOW THE DENDRITIC GROWTH ZONE. THE WEATHER THE REST OF THE WEEK APPEARS TO BE FAIRLY QUIT...BUT ON A WARMING TREND. MID LEVEL HEIGHT RISES ARE EXPECTED TO OVERSPREAD MUCH OF THE CENTRAL CONUS LATER IN THE PERIOD IN RESPONSE TO THE PERSISTENT NEGATIVE HEIGHT ANOMALIES ACROSS THE NORTHEASTERN PACIFIC AND GULF OF ALASKA REGION SHIFTING EASTWARD TOWARDS THE WESTERN NORTH AMERICAN COAST. THIS PARTICULARLY PATTERN STILL LOOKS TO BE CONDUCE FOR A PERIOD OF MUCH ABOVE NORMAL TEMPERATURES NEXT FRIDAY AND ESPECIALLY INTO SATURDAY. MODEL GUIDANCE HAS BEEN IN GOOD AGREEMENT IN INDICATING THIS LARGER SCALE EL NINO-LIKE PATTERN EVOLVING...AND GIVEN THAT THIS IS PATTERN KNOWN FOR PRODUCING MILD CONDITIONS LOCALLY...CONFIDENCE IS ABOVE AVERAGE FOR THIS PERIOD TO EXPERIENCE ABOVE AVERAGE TEMPERATURES. AT THIS TIME I HAVE REMAINED A BIT CONSERVATIVE ON TEMPERATURES...ONLY WARMING THEM TO NEAR 50 FOR SATURDAY. THIS COULD BE SEVERAL DEGREES TOO LOW IF THE CURRENT MODEL FORECASTS PAN OUT. MOST GUIDANCE IS INDICATING 925 MB TEMPERATURES ANYWHERE FROM +6 TO +10 DEGREES CELSIUS...WHICH COULD SUPPORT TEMPERATURES INTO THE 50S BY NEXT SATURDAY UNDER A 570+ DM MID LEVEL RIDGE. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SOUTHEAST WINDS AROUND 10 KT TODAY. * LOWERING CIGS AND A PERIOD OF MIXED PRECIPITATION STARTING AROUND OR JUST AFTER 12Z MONDAY. MDB //DISCUSSION...UPDATED 06Z... HIGH PRESSURE IS OVERHEAD OF THE TERMINALS TONIGHT ALLOWING FOR LIGHT NORTHEAST WINDS. WINDS WILL SWING AROUND TO THE SOUTHEAST OVERNIGHT AND BE FAIRLY STEADY AROUND 10 KT DURING THE DAY. WINDS WILL TURN TO THE SOUTH INTO MONDAY MORNING. VFR HIGH CLOUDS WILL STREAM OVERHEAD THROUGH THE DAY TODAY AND TONIGHT BEFORE LOWERING INTO MONDAY MORNING AHEAD OF A LOW PRESSURE SYSTEM/COLD FRONT. A PERIOD OF MIXED PRECIPITATION IS EXPECTED MONDAY MORNING...LIKELY STARTING JUST PRIOR TO 12Z AT RFD AND AROUND OR SOON AFTER 12Z AT DPA/ORD/MDW/GYY. DETAILS ARE STILL IN FLUX BUT SOME SNOW/SLEET ACCUMULATION IS POSSIBLE WITH A PERIOD OF IFR CIGS/VSBY POSSIBLE. MDB //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN SOUTHEAST WINDS AROUND 10 KT TODAY. * HIGH CONFIDENCE IN LOWERING CIGS AND A PERIOD OF MIXED PRECIPITATION MONDAY MORNING. MDB //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...CHANCE OF SLEET/SNOW MIX IN THE MORNING. MVFR/BRIEF IFR POSSIBLE. S WINDS BECOMING W. TUESDAY...VFR. NW WINDS BECOMING N. WEDNESDAY...VFR. N WINDS BECOMING NE. THURSDAY...VFR. S WINDS. FRIDAY...VFR. S WINDS. RATZER && .MARINE... 222 PM CST TONIGHT THROUGH SUNDAY THE STIFF NORTHERLY WINDS ACROSS THE LAKE TODAY WILL EASE THIS EVENING AND VEER EASTWARD BY OVERNIGHT. WAVES WILL SUBSIDE BELOW 5 FT BY LATE TONIGHT. THE PROGRESSIVE PATTERN CONTINUES WITH HIGH PRESSURE ADVANCING OVER THE LAKE QUICKLY OVERNIGHT FOLLOWED BY INFLUENCE OF APPROACHING LOW PRESSURE ALREADY BY SUNDAY WITH WINDS TURNING SOUTHEASTERLY. SUNDAY NIGHT ONWARD STRONG HIGH PRESSURE SHIFTING EASTWARD FROM QUEBEC AND WEAK LOW PRESSURE TRACKING EAST ALONG THE CANADIAN BORDER WILL REALLY TIGHTEN THE PRESSURE GRADIENT AND CAUSE SOUTHEAST WINDS TO TURN SOUTH AND STRENGTHEN ON SUNDAY NIGHT INTO MONDAY MORNING. LOOKING AT GUSTS PRIMARILY UP TO 25 TO 30 KT OVER THE OPEN WATERS...BUT COULD SEE A FEW GALE FORCE GUSTS ON NORTH HALF. COLD FRONT TRAILING FROM THE WEAK LOW PRESSURE WILL CROSS THE LAKE MONDAY EVENING AND NIGHT...FOLLOWED BY ANOTHER EXPANSIVE HIGH PRESSURE. WINDS WILL TURN WEST-NORTHWEST MONDAY NIGHT TO NORTHERLY BY TUESDAY MORNING. CURRENTLY EXPECTING SPEEDS/GUSTS UP TO 30 KT LATE MONDAY NIGHT THROUGH TUESDAY...BUT AGAIN CANNOT RULE OUT A PERIOD OF GALES ON THE NORTH TUESDAY MORNING WHEN PRESSURE RISES MAXIMIZE. NORTHERLY WINDS WILL GRADUALLY DIMINISH ON TUESDAY NIGHT INTO WEDNESDAY AS THE HIGH TRAVERSES THE LAKE...SHIFTING TO SOUTHWEST ON THURSDAY INTO THURSDAY NIGHT ON THE BACK SIDE OF THE HIGH. FOR THE NEARSHORE WATERS...SMALL CRAFT ADVISORY CRITERIA IS POSSIBLE SUNDAY NIGHT INTO MONDAY MORNING...ESPECIALLY FOR THE ILLINOIS SHORE. SMALL CRAFT CONDITIONS ARE THEN LIKELY TUESDAY MORNING INTO WEDNESDAY. MTF/RC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 3 AM SUNDAY. && $$ 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 1132 PM CST Sat Dec 6 2014 .UPDATE... ISSUED AT 822 PM CST SAT DEC 6 2014 The low clouds that plagued our area all day long have cleared all but our far south and southeast counties this evening. However, a large band of cirrus was streaming east into our area and will be with us overnight and into most of Sunday. Temperatures for the first few hours after skies cleared fell rapidly across the north but have since steadied out some as the high level cloud cover overspread the area. The latest surface map has a large area of high pressure over central Wisconsin which is expected to push east across the central Great Lakes over the next 24 hours keeping our weather quiet. Have already sent out an update to address the overnight temperatures across the north, with the remainder of the forecast in good shape this evening. && .SHORT TERM...(Tonight) ISSUED AT 308 PM CST SAT DEC 6 2014 Clearing trend has finally started to make some headway southward this afternoon, with the edge of the stratocumulus deck generally along a Macomb to Peoria to Pontiac line at 230 pm. AWIPS timing tool would suggest a position along I-72 in the 530-6 pm time frame, while the HRRR is a bit slower around 8 pm. Additional erosion from the northeast is indicated by the HRRR late evening, although at the same time cirrus clouds will be streaming east from the Plains. Thus, have mainly gone with a partly cloudy sky for tonight`s forecast. North/northeast flow to prevail into tonight, as high pressure currently over Lake Superior settles southeast across the Great Lakes. Temperatures expected to drop into the mid to upper 20s overnight. && .LONG TERM...(Sunday through Saturday) ISSUED AT 308 PM CST SAT DEC 6 2014 High pressure will shift eastward from Illinois Sunday as a clipper system approaches from the WNW. This system will start bringing increasingly thick high clouds through the day Sunday, but the air mass will generally remain quite dry in a layer from around 2000 to 12000 feet. This dry layer will take some time to saturate overnight, which means only a slight chance for precipitation NW of the Illinois River before midnight. These layers will saturate through the night allowing a better chance for precipitation reaching the surface mainly during the morning. Dry air will start to move in aloft during the day Monday as the system shifts east of the area, ending deep enough saturation for precipitation processes to take place. Precipitation type looks to be largely rain for central Illinois given a deep warm layer just off the surface. Still some chance for light freezing rain with temperatures hovering very near the freezing mark at the surface. Farther to the north, the warm layer off the surface is less pronounced, which could allow for snow or a mix of rain and snow to reach the surface.. A high pressure ridge will develop over the plains for much of the week with NW flow and dry conditions for central IL. Temperatures will remain below normal for much of the week as a result. Friday and Saturday may see a substantial warmup as the plains ridge shifts over IL. Only chance for precipitation in the extended forecast at this time appears to be around Friday morning as a few models hint at a weak disturbance meandering through the region at this time. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) ISSUED AT 1122 PM CST SAT DEC 6 2014 VFR CONDITIONS SHOULD PREVAIL OVER THE TAF SITES THROUGH THE PERIOD...WITH A SLIGHT EXCEPTION FOR SPI AS HAZE STILL LINGERS REDUCING VIS TO MVFR. HOWEVER...DO NOT THINK THIS WILL STICK AROUND VERY LONG SINCE UPSTREAM AT AAA VIS HAS ALREADY CLEARED OUT ABOVE 6SM FROM THE HIGH PRESSURE BUILDING OVER THE GREAT LAKES. THEREFORE...USED A TEMPO GROUP FOR THE NEXT HOUR TO ACCOUNT FOR THE REDUCED VIS IMPROVING TO VFR WITHIN THE HOUR. OTHERWISE...HIGH CLOUDS ARE MOVING IN OVER THE TAF SITES WITH THE NEXT STORM SYSTEM OUT IN THE PLAINS. ALONG WITH HIGH CLOUDS STREAMING IN...WINDS SHOULD BEGIN TO SHIFT TO THE EAST AND THEN SOUTHEAST BY TOMORROW. CIGS APPEAR TO REMAIN VFR THROUGH THE TAF PERIOD ACCORDING TO GUIDANCE AND SOUNDINGS. PIA...BMI...AND SPI COULD SEE VCSH TOMORROW NIGHT AROUND 03Z/04Z...BUT NOT CONFIDENT ENOUGH IN RAIN FALLING OVER THE SITES BEFORE 06Z TO INCLUDE ANYTHING ELSE. THIS CAN BE UPDATED IN LATER TAF ISSUANCES IF NEEDED. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Smith SHORT TERM...Geelhart LONG TERM...Onton AVIATION...ALW
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
924 PM EST MON DEC 8 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 222 PM EST MON DEC 8 2014 A COLD FRONT AND AN UPPER TROUGH WILL KEEP CHANCES FOR PRECIPITATION ACROSS CENTRAL INDIANA INTO TUESDAY. AFTERWARD HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THROUGH THE WEEKEND. CHANCES FOR RAIN RETURN MONDAY. BELOW AVERAGE TEMPERATURES WILL GIVE WAY TO ABOVE NORMAL READINGS BY THE WEEKEND. && .NEAR TERM /REST OF TONIGHT/... ISSUED AT 836 PM EST MON DEC 8 2014 0130Z UPDATE...BASED ON TRENDS THUS FAR THIS EVENING AGREE WITH PREVIOUS THINKING ON THE OVERNIGHT WEATHER. ONLY CHANGES WERE TO INCREASE POPS LATE THIS EVENING ON AVERAGE OF 20 PERCENT TO ACCOUNT FOR THE SECOND WAVE OF VERY LIGHT RAIN AND/OR DRIZZLE MOVING IN FROM CENTRAL ILLINOIS. LATEST RUNS SHOW HRRR AND SREF HAVE BACKED OFF ON POPS CONSIDERABLY AFTER 06Z...WHICH WILL BE POST FRONTAL PASSAGE...SO LEFT POPS AS IS AFTER THIS TIME. WILL NEED TO MONITOR TEMPERATURES ESPECIALLY AFTER 06Z AND FOR ANY ADDITIONAL SIGNIFICANT PRECIP DEVELOPMENT...BECAUSE IF TEMPS PLUMMET MAY HAVE SOME FREEZING DRIZZLE CONCERNS WHICH COULD CAUSE SLICK/ICY ROADS. MOST LOW TEMPERATURES IN FORECAST FOR CWA ARE EXPECTED TO REMAIN ABOVE FREEZING SO THIS IS NOT EXPECTED TO BE AN ISSUE...BUT WILL BE CLOSELY MONITORED REGARDLESS FOR POTENTIAL NEED FOR UPDATES AND/OR STATEMENTS. PREVIOUS DISCUSSION FOLLOWS... TONIGHT AN UPPER LOW WILL MOVE INTO THE AREA AND PROVIDE SOME ADDITIONAL FORCING. MAV MOS GIVES VERY LOW POPS WHILE MET MOS IS PRETTY HIGH. REALITY WILL LIKELY BE IN BETWEEN. MOISTURE BECOMES LIMITED TO THE LOWER LAYERS OF THE ATMOSPHERE PRETTY QUICKLY...SO THERE IS SOME QUESTION WHETHER ICE WILL BE INTRODUCED INTO THE CLOUD. TIME SECTIONS SHOW THAT IT WILL BE CLOSE...SO WILL KEEP MENTION OF DRIZZLE AND RAIN/SNOW THROUGH THE NIGHT. PRECIPITATION WILL BE LIQUID THROUGH THE EVENING...BUT TEMPERATURES COOL FROM NORTHWEST TO SOUTHEAST TONIGHT MAKING ANY PRECIPITATION /ASIDE FROM THE DRIZZLE/ SNOW. WENT NEAR MAV MOS MOST AREAS FOR LOWS TONIGHT. THIS KEEPS TEMPERATURES ABOVE FREEZING FOR MOST OF THE AREA FOR THE VAST MAJORITY OF THE NIGHT. THUS WHILE CANNOT ABSOLUTELY RULE OUT FREEZING DRIZZLE AT THIS TIME...FEEL THAT COVERAGE AND LENGTH OF ANY THAT DOES APPEAR IS TOO LOW TO MENTION AT THIS TIME. WILL KEEP MENTION OF SLICK SPOTS EARLY IN THE MORNING IN THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR BRIDGES/OVERPASSES/UNTREATED SURFACES. && .SHORT TERM.../TUESDAY THROUGH THURSDAY/ ISSUED AT 222 PM EST MON DEC 8 2014 FOCUS IS ON ANY CHANCES FOR PRECIPITATION TUESDAY THEN ON SKY COVER. MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED. EXITING UPPER SYSTEM AND CYCLONIC FLOW WILL KEEP CLOUDY SKIES ON TUESDAY AND COULD ALSO HELP PRODUCE SOME LIGHT PRECIPITATION...ESPECIALLY IF SOME LAKE ENHANCEMENT OCCURS ACROSS THE NORTHEAST. PROBLEM REMAINS LACK OF DEEP MOISTURE AND POTENTIAL LACK OF ICE IN THE CLOUDS. WITH THE UNCERTAINTY IN PRECIPITATION TYPE DECIDED TO KEEP MENTION OF DRIZZLE AND SNOW WITH LOW POPS MOST AREAS. AS NOTED IN THE NEAR TERM CANNOT ABSOLUTELY RULE OUT A BRIEF PERIOD OF FREEZING DRIZZLE SOME AREAS VERY EARLY TUESDAY...BUT NOT CONFIDENT ENOUGH TO MENTION AT THIS TIME. TUESDAY NIGHT FORCING ENDS SO DO NOT EXPECT PRECIPITATION. HIGH PRESSURE TRIES TO BUILD IN FROM THE WEST...BUT STRONG SYSTEM ACROSS THE NORTHEASTERN USA KEEPS THE AREA IN CYCLONIC FLOW. THUS EXPECT PLENTY OF CLOUDS ACROSS THE AREA. THE CLOUDS WILL LINGER INTO WEDNESDAY...ESPECIALLY EAST WITH THE AFOREMENTIONED STRONG SYSTEM. HIGH PRESSURE SHOULD GAIN MORE INFLUENCE WEDNESDAY NIGHT INTO THURSDAY...SO ALLOWED FOR PARTLY CLOUDY CONDITIONS ALL AREAS THEN. FOR TEMPERATURES...WENT BELOW MOS FOR HIGHS TUESDAY GIVEN EXPECTED CLOUD COVER. CUT SOME ON WEDNESDAY AS WELL WITH EXPECTED SKY COVER. OTHERWISE GENERALLY STUCK WITH A MODEL BLEND. && .LONG TERM /THURSDAY THROUGH MONDAY/... ISSUED AT 257 PM EST MON DEC 8 2014 MODELS IN GOOD AGREEMENT THAT A BROAD AREA OF SURFACE HIGH PRESSURE ALONG WITH A DRY ATMOSPHERIC COLUMN WILL RESULT IN ABOVE NORMAL TEMPERATURES AND DRY WEATHER THROUGH THE WEEKEND. MEANWHILE...THE OPERATIONAL 12Z GFS AND ECMWF ARE HAVING DIFFICULTIES COMING TOGETHER FOR DAY 7 WITH THE GFS QUICKER WITH SEPARATE UPPER LOWS...IN SPLIT FLOW...ACROSS THE UPPER AND LOWER MISSISSIPPI VALLEYS. DESPITE BEING QUICKER WITH THESE SYSTEMS...THE GFS WAS SLOWER WITH THE QPF THAN THE EURO. WITH THE GFS TYPICAL TOO FAST AND THE EURO TO STRONG WITH STRONGER SYSTEMS IN SPLIT FLOW...WILL ACCEPT THE REGIONAL BLEND WHICH HOLDS OFF RAIN CHANCES TIL MONDAY. 00Z DECEMBER 8 ECM MOS HIGHS CLOSE TO REGIONAL BLEND AND LOOK GOOD WITH ABOVE AVERAGE HIGHS IN THE 40S AND PERHAPS EVEN 50S BY SUNDAY. THIS ALSO MATCHES UP NICELY WITH THE CLIMATE PREDICTION CENTER 6 TO 10 DAY OUTLOOK WHICH STRONGLY FAVORS ABOVE NORMAL TEMPERATURES FOR THE EXTENDED. && .AVIATION /DISCUSSION FOR THE 090300Z KIND TAF UPDATE/... ISSUED AT 924 PM EST MON DEC 8 2014 COLD FRONT CURRENTLY MOVING INTO FAR WESTERN INDIANA WITH AREAS OF LIGHT RAIN/DRIZZLE AHEAD OF IT. TIMING OF THE FRONT AT KIND MAY BE SLIGHTLY FASTER THAN WHAT IS CURRENTLY IN THE FORECAST...BUT NOT BY MUCH. ALSO APPEARS THERE MAY BE LESS IN THE WAY OF POST FRONTAL IFR CEILINGS BASED ON WHAT IS UPSTREAM. WILL HOLD THINGS AS IS FOR NOW AND KEEP AN EYE ON THE TRENDS. PREVIOUS DISCUSSION FOLLOWS. WIDESPREAD CEILINGS 005-007 AGL...ALONG WITH AREAS OF IFR VISIBILITY RESTRICTIONS...CURRENTLY MOVING INTO THE WESTERN SECTIONS OF THE STATE. THESE CONDITIONS EXPECTED TO OVERSPREAD THE TAF SITES BY OR SHORTLY AFTER ISSUANCE TIME. A FRONTAL SYSTEM IS EXPECTED TO PASS OVER THE TAF SITES LATER TONIGHT...ROUGHLY 090300Z-090800Z. AREAS OF DRIZZLE OR LIGHT RAIN POSSIBLE AHEAD OF FRONT. AN IMPROVEMENT IN THE LOW CONDITIONS IS EXPECTED IN THE WAKE OF FRONTAL PASSAGE...WITH CEILING RISING TO AROUND 015 BY SUNRISE TUESDAY. WIND SHIFT IN ASSOCIATION WITH FRONTAL PASSAGE LOOK RATHER DIFFUSE IN THE MODELS...SO EXPECTING MORE A GRADUAL VEERING OF THE WIND AROUND TO 290-310 DEGREES BY THE EARLY MORNING HOURS WITH SPEEDS INCREASING TO 10-13 KTS. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...SMF/50 SHORT TERM...50 LONG TERM...KOCH AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
853 PM EST MON DEC 8 2014 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 222 PM EST MON DEC 8 2014 A COLD FRONT AND AN UPPER TROUGH WILL KEEP CHANCES FOR PRECIPITATION ACROSS CENTRAL INDIANA INTO TUESDAY. AFTERWARD HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THROUGH THE WEEKEND. CHANCES FOR RAIN RETURN MONDAY. BELOW AVERAGE TEMPERATURES WILL GIVE WAY TO ABOVE NORMAL READINGS BY THE WEEKEND. && .NEAR TERM /REST OF TONIGHT/... ISSUED AT 836 PM EST MON DEC 8 2014 0130Z UPDATE...BASED ON TRENDS THUS FAR THIS EVENING AGREE WITH PREVIOUS THINKING ON THE OVERNIGHT WEATHER. ONLY CHANGES WERE TO INCREASE POPS LATE THIS EVENING ON AVERAGE OF 20 PERCENT TO ACCOUNT FOR THE SECOND WAVE OF VERY LIGHT RAIN AND/OR DRIZZLE MOVING IN FROM CENTRAL ILLINOIS. LATEST RUNS SHOW HRRR AND SREF HAVE BACKED OFF ON POPS CONSIDERABLY AFTER 06Z...WHICH WILL BE POST FRONTAL PASSAGE...SO LEFT POPS AS IS AFTER THIS TIME. WILL NEED TO MONITOR TEMPERATURES ESPECIALLY AFTER 06Z AND FOR ANY ADDITIONAL SIGNIFICANT PRECIP DEVELOPMENT...BECAUSE IF TEMPS PLUMMET MAY HAVE SOME FREEZING DRIZZLE CONCERNS WHICH COULD CAUSE SLICK/ICY ROADS. MOST LOW TEMPERATURES IN FORECAST FOR CWA ARE EXPECTED TO REMAIN ABOVE FREEZING SO THIS IS NOT EXPECTED TO BE AN ISSUE...BUT WILL BE CLOSELY MONITORED REGARDLESS FOR POTENTIAL NEED FOR UPDATES AND/OR STATEMENTS. PREVIOUS DISCUSSION FOLLOWS... TONIGHT AN UPPER LOW WILL MOVE INTO THE AREA AND PROVIDE SOME ADDITIONAL FORCING. MAV MOS GIVES VERY LOW POPS WHILE MET MOS IS PRETTY HIGH. REALITY WILL LIKELY BE IN BETWEEN. MOISTURE BECOMES LIMITED TO THE LOWER LAYERS OF THE ATMOSPHERE PRETTY QUICKLY...SO THERE IS SOME QUESTION WHETHER ICE WILL BE INTRODUCED INTO THE CLOUD. TIME SECTIONS SHOW THAT IT WILL BE CLOSE...SO WILL KEEP MENTION OF DRIZZLE AND RAIN/SNOW THROUGH THE NIGHT. PRECIPITATION WILL BE LIQUID THROUGH THE EVENING...BUT TEMPERATURES COOL FROM NORTHWEST TO SOUTHEAST TONIGHT MAKING ANY PRECIPITATION /ASIDE FROM THE DRIZZLE/ SNOW. WENT NEAR MAV MOS MOST AREAS FOR LOWS TONIGHT. THIS KEEPS TEMPERATURES ABOVE FREEZING FOR MOST OF THE AREA FOR THE VAST MAJORITY OF THE NIGHT. THUS WHILE CANNOT ABSOLUTELY RULE OUT FREEZING DRIZZLE AT THIS TIME...FEEL THAT COVERAGE AND LENGTH OF ANY THAT DOES APPEAR IS TOO LOW TO MENTION AT THIS TIME. WILL KEEP MENTION OF SLICK SPOTS EARLY IN THE MORNING IN THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR BRIDGES/OVERPASSES/UNTREATED SURFACES. && .SHORT TERM.../TUESDAY THROUGH THURSDAY/ ISSUED AT 222 PM EST MON DEC 8 2014 FOCUS IS ON ANY CHANCES FOR PRECIPITATION TUESDAY THEN ON SKY COVER. MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED. EXITING UPPER SYSTEM AND CYCLONIC FLOW WILL KEEP CLOUDY SKIES ON TUESDAY AND COULD ALSO HELP PRODUCE SOME LIGHT PRECIPITATION...ESPECIALLY IF SOME LAKE ENHANCEMENT OCCURS ACROSS THE NORTHEAST. PROBLEM REMAINS LACK OF DEEP MOISTURE AND POTENTIAL LACK OF ICE IN THE CLOUDS. WITH THE UNCERTAINTY IN PRECIPITATION TYPE DECIDED TO KEEP MENTION OF DRIZZLE AND SNOW WITH LOW POPS MOST AREAS. AS NOTED IN THE NEAR TERM CANNOT ABSOLUTELY RULE OUT A BRIEF PERIOD OF FREEZING DRIZZLE SOME AREAS VERY EARLY TUESDAY...BUT NOT CONFIDENT ENOUGH TO MENTION AT THIS TIME. TUESDAY NIGHT FORCING ENDS SO DO NOT EXPECT PRECIPITATION. HIGH PRESSURE TRIES TO BUILD IN FROM THE WEST...BUT STRONG SYSTEM ACROSS THE NORTHEASTERN USA KEEPS THE AREA IN CYCLONIC FLOW. THUS EXPECT PLENTY OF CLOUDS ACROSS THE AREA. THE CLOUDS WILL LINGER INTO WEDNESDAY...ESPECIALLY EAST WITH THE AFOREMENTIONED STRONG SYSTEM. HIGH PRESSURE SHOULD GAIN MORE INFLUENCE WEDNESDAY NIGHT INTO THURSDAY...SO ALLOWED FOR PARTLY CLOUDY CONDITIONS ALL AREAS THEN. FOR TEMPERATURES...WENT BELOW MOS FOR HIGHS TUESDAY GIVEN EXPECTED CLOUD COVER. CUT SOME ON WEDNESDAY AS WELL WITH EXPECTED SKY COVER. OTHERWISE GENERALLY STUCK WITH A MODEL BLEND. && .LONG TERM /THURSDAY THROUGH MONDAY/... ISSUED AT 257 PM EST MON DEC 8 2014 MODELS IN GOOD AGREEMENT THAT A BROAD AREA OF SURFACE HIGH PRESSURE ALONG WITH A DRY ATMOSPHERIC COLUMN WILL RESULT IN ABOVE NORMAL TEMPERATURES AND DRY WEATHER THROUGH THE WEEKEND. MEANWHILE...THE OPERATIONAL 12Z GFS AND ECMWF ARE HAVING DIFFICULTIES COMING TOGETHER FOR DAY 7 WITH THE GFS QUICKER WITH SEPARATE UPPER LOWS...IN SPLIT FLOW...ACROSS THE UPPER AND LOWER MISSISSIPPI VALLEYS. DESPITE BEING QUICKER WITH THESE SYSTEMS...THE GFS WAS SLOWER WITH THE QPF THAN THE EURO. WITH THE GFS TYPICAL TOO FAST AND THE EURO TO STRONG WITH STRONGER SYSTEMS IN SPLIT FLOW...WILL ACCEPT THE REGIONAL BLEND WHICH HOLDS OFF RAIN CHANCES TIL MONDAY. 00Z DECEMBER 8 ECM MOS HIGHS CLOSE TO REGIONAL BLEND AND LOOK GOOD WITH ABOVE AVERAGE HIGHS IN THE 40S AND PERHAPS EVEN 50S BY SUNDAY. THIS ALSO MATCHES UP NICELY WITH THE CLIMATE PREDICTION CENTER 6 TO 10 DAY OUTLOOK WHICH STRONGLY FAVORS ABOVE NORMAL TEMPERATURES FOR THE EXTENDED. && .AVIATION /DISCUSSION FOR THE 090000Z TAFS/... ISSUED AT 535 PM EST MON DEC 8 2014 WIDESPREAD CEILINGS 005-007 AGL...ALONG WITH AREAS OF IFR VISIBILITY RESTRICTIONS...CURRENTLY MOVING INTO THE WESTERN SECTIONS OF THE STATE. THESE CONDITIONS EXPECTED TO OVERSPREAD THE TAF SITES BY OR SHORTLY AFTER ISSUANCE TIME. A FRONTAL SYSTEM IS EXPECTED TO PASS OVER THE TAF SITES LATER TONIGHT...ROUGHLY 090300Z-090800Z. AREAS OF DRIZZLE OR LIGHT RAIN POSSIBLE AHEAD OF FRONT. AN IMPROVEMENT IN THE LOW CONDITIONS IS EXPECTED IN THE WAKE OF FRONTAL PASSAGE...WITH CEILING RISING TO AROUND 015 BY SUNRISE TUESDAY. WIND SHIFT IN ASSOCIATION WITH FRONTAL PASSAGE LOOK RATHER DIFFUSE IN THE MODELS...SO EXPECTING MORE A GRADUAL VEERING OF THE WIND AROUND TO 290-310 DEGREES BY THE EARLY MORNING HOURS WITH SPEEDS INCREASING TO 10-13 KTS. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...SMF/50 SHORT TERM...50 LONG TERM...KOCH AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
746 PM MST MON DEC 8 2014 .UPDATE... ISSUED AT 745 PM MST MON DEC 8 2014 UPDATES REQUIRED FOR FIRST AND SECOND PERIODS (TONIGHT AND TUESDAY) FOCUSING ON ARRIVAL OF POTENTIALLY DENSE FOG AND LOWER TEMPERATURES THEN PREVIOUSLY FORECAST. AT 0230Z CIRRUS SHIELD THAT WAS OVER THE AREA MOST OF THE DAY IS MOVING EAST AND SLOWLY OUT OF THE AREA. AM EXPECTING MORE TO MOVE IN LATER IN THE EVENING AND THROUGH THE DAY TOMORROW FROM THE NORTHWEST. AT THE SFC STRATUS PER SATELLITE OBS AND RUC 900MB RH FORECAST CURRENTLY OVER NORTHEAST NEBRASKA/SOUTHWEST IOWA. BY 06Z THIS NARROW CORRIDOR OF STRATUS FORECAST TO POSSIBLY REACH AREAS JUST TO THE NORTHEAST FROM MCCOOK TO NORTON. AS SFC HIGH CONTINUES TO BACK INTO THE AREA WITH LIGHT NORTHEAST WINDS STRATUS DECK EXPECTED TO REACH A TRENTON TO HILL CITY LINE BY 09Z THEN ROUGHLY A BENKELMAN TO COLBY AND OAKLEY LINE BY 12Z. IN THE TRENTON TO HILL CITY AND POINTS NORTHEAST AREAS WINDS ARE CALM AND RH NEAR 100 PERCENT. LATEST RUC/HRRR/NAM VISIBILITY FORECASTS ALL SHOWING DENSE FOG WITH VISIBILITIES 1/4 MILE OR LESS. NAM EXTRAPOLATION OF SATURATED BOUNDARY LAYER RH PUSHES IT FURTHER WEST TOWARD THE CO/KS BORDER WITH DENSE FOG CONTINUING ROUGHLY FROM TRENTON TO HOXIE AND POINTS EAST. HRRR SUGGESTS FURTHER WEST TOWARD BENKELMAN TO NEAR GOODLAND AND RUSSELL SPRINGS. WILL AWAIT THE 03Z RUC/LATEST HRRR BEFORE ZONE UPDATE SENT BUT HAVE TRENDED TOWARD ABOVE THINKING. && .SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY) ISSUED AT 119 PM MST MON DEC 8 2014 DECENT AFTERNOON ACROSS THE ENTIRE FORECAST AREA...AS THE TRI STATE REGION IS SEEING TEMPERATURES 15 TO 20 DEGREES ABOVE NORMAL WITH READINGS WELL INTO THE 50S. THIS IS ONGOING DESPITE HIGH CLOUDS MOVING OVER THE AREA CREATING SUNNY CONDITIONS. HIGH CLOUD COVER WILL SCATTER OUT DURING THE EARLY EVENING HOURS IN TIME FOR 925MB THERMAL BOUNDARY/SURFACE RIDGE AXIS COMBO...WHICH MODELS BRING OVER THE REGION BY MIDNIGHT TONIGHT. MODEL RH IN LATEST BUFKIT RUNS DOES HINT AT FOG/LOW STRATUS FORMATION BETWEEN 06Z-14Z TUESDAY...WITH BEST CHANCES OVER IN CENTRAL AND EASTERN ZONES. LGT/VAR WIND CONDITIONS WILL ALSO AID IN FOG FORMATION IN THE AFOREMENTIONED ZONES...SO WILL KEEP PREVIOUS MENTION OF FOG IN THE FORECAST. GOING INTO TUESDAY...SURFACE HIGH PRESSURE SETTLES OVER CENTRAL AND EASTERN PLAINS. THIS IS GOING TO SET UP YET ANOTHER NICE DAY FOR MUCH OF THE CWA. MUCH OF THE WESTERN CWA WILL SEE WAA AGAIN ON SOUTHERLY FLOW...WHILE EASTERN ZONES WILL BE CLOSE ENOUGH TO SURFACE RIDGE THAT WINDS WILL NOT BE MAJOR FACTOR...SO HAVE TAPERED HIGHS FOR TOMORROW FROM WEST TO EAST...MID 50S WEST DOWN TO THE MID 40S ACROSS EASTERN PORTIONS. .LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY) ISSUED AT 135 PM MST MON DEC 8 2014 OLD FRONTAL BOUNDARY WILL RETURN EAST AS WARM FRONT AND STALL OUT ACROSS THE FORECAST AREA TUESDAY NIGHT. EAST OF THE FRONT...LOW LEVELS WILL SATURATE OVERNIGHT SETTING THE STAGE FOR AREAS OF FOG AND DRIZZLE. SURFACE WET BULB TEMPERATURES WILL BE IN THE LOWER 30S EAST OF THE BOUNDARY SO CANNOT TOTALLY RULE OUT FREEZING DRIZZLE. NAM SOUNDINGS ARE CONSIDERABLY MORE MOIST OVER A DEEPER LAYER COMPARED TO THE GFS SOUNDINGS...BUT EVEN IN THAT SCENARIO ACCUMULATION WOULD ONLY BE A FEW HUNDREDTHS OF AN INCH. NONETHELESS...WILL NEED TO MONITOR FOR POTENTIAL HIGHLIGHT FOR FREEZING DRIZZLE. CLOUDS WILL SLOWLY ERODE WEST TO EAST WEDNESDAY AFTERNOON...WITH EASTERN COUNTIES OF NORTHWEST KANSAS SUCH AS NORTON AND GRAHAM POSSIBLY STUCK IN THE CLOUDS ALL DAY AND WILL TREND MAX TEMPERATURES DOWN IN THOSE AREAS. CLOUDS WILL START TO RETURN WEST WEDNESDAY NIGHT WITH AREAS OF FOG AND DRIZZLE DEVELOPING ONCE AGAIN. THERE IS A NARROW BAND ON THE WESTERN EDGE OF THE MOISTURE WHERE SURFACE WET BULBS DIP BELOW FREEZING AND WILL CARRY A MENTION OF FREEZING DRIZZLE IN THOSE AREAS. CLOUDS WILL ERODE WEST TO EAST A LITTLE MORE QUICKLY ON FRIDAY WITH SUNNY SKIES BY THE AFTERNOON AND WARMER TEMPERATURES UNDER SHORTWAVE RIDGING ALOFT. A STRONG SYSTEM WILL MOVE OUT OF THE SOUTHERN ROCKIES LATE WEEK AND EJECT ACROSS THE SOUTHERN PLAINS OVER THE WEEKEND. THIS TRACK WILL BE TOO FAR SOUTH TO BRING PRECIPITATION CHANCES TO THE HIGH PLAINS AND HAVE GONE WITH A DRY FORECAST. HOWEVER ASSOCIATED SURFACE COLD FRONT WILL BRING COLDER TEMPERATURES SUNDAY AND MONDAY WITH HIGHS IN THE 40S AND LOWS IN THE TEENS AND 20S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 400 PM MST MON DEC 8 2014 KGLD...VFR THROUGH 10Z WITH WINDS 5KTS OR LESS UNDER A LAYER OF CIRRUS. FROM 11Z-17Z STRATUS/BR MOVE IN FROM THE NORTHEAST BRINGING A PERIOD OF POSSIBLY IFR CIGS AND SOME REDUCED VISIBILITIES. FROM 18Z THROUGH THE REST OF THE TAF PERIOD WINDS FROM THE SOUTH NEAR 11KTS WITH BKN LAYER OF CIRRUS. KMCK...VFR THROUGH 07Z WITH WINDS 5KTS OR LESS UNDER A LAYER OF CIRRUS. FROM 08Z THROUGH 18Z IFR/VLIFR CIGS/VIS EXPECTED TO MOVE IN FROM THE NORTHEAST WITH LIGHT/VARIABLE WINDS. AROUND 19Z STRATUS EXPECTED TO THIN OUT ENOUGH TO PRODUCE VFR CONDITIONS WITH ONLY A LAYER OF CIRRUS AND SOUTHEAST/EAST-SOUTHEAST WINDS AROUND 5KTS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...JN LONG TERM...024 AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
400 PM MST SUN DEC 7 2014 .SHORT TERM...(THIS AFTERNOON THROUGH MONDAY) ISSUED AT 212 PM MST SUN DEC 7 2014 LATEST WV IMAGERY AND RAP ANALYSIS SHOW RIDGING BUILDING ACROSS WESTERN US...WITH TROUGH CENTERED OVER NORTH DAKOTA AND ITS AXIS EXTENDING ACROSS EASTERN NE/KS INTO THE SOUTHERN PLAINS. AT THE SURFACE LOW PRESSURE HAS BUILD ACROSS NORTHERN COLORADO WITH A WEAK SURFACE TROUGH OVER OUR CWA. STRATUS FOG HAS ERODED AND CLEAR SKIES/DOWNSLOPE FLOW HAS LED TO TEMPS WARMING INTO THE MIDDLE 60S ACROSS NW KANSAS AND PARTS OF NORTHEAST COLORADO. SHORTWAVE RIDGE WILL TRANSITION OVER THE CWA TONIGHT AND MONDAY WITH DRY CONDITIONS AND MILD TEMPS PERSISTING. THERE IS A WEAK SHORTWAVE THAT MIGHT BRING SLIGHTLY COOLER TEMPS ALOFT AND HIGH CLOUD COVER MONDAY AFTERNOON...OTHERWISE WE SHOULD SEE LITTLE CHANGE IN SENSIBLE WEATHER OVER CWA. GOOD RADIATIONAL CONDITIONS SHOULD BE IN PLACE AND DEPENDING ON HOW LOW THE TD VALUES WILL DROP WE COULD SEE OVERNIGHT LOWS IN THE UPPER TEENS TO LOWER 20S. MET GUIDANCE WAS HINTING AT LIGHT FOG DEVELOPMENT...HOWEVER ALL OTHER 2M AND STATISTICAL GUIDANCE IS NOT SHOWING THIS...AND WITH DRY AIR ADVECTING FROM THE WEST TO SOUTHWEST I DECIDED AGAINST FOG MENTION. DESPITE SLIGHTLY COOLER TEMPS ALOFT MONDAY...THE TREND HAS BEEN FOR MOST GUIDANCE TO HAVE A COOL BIAS WITH GOOD WARMING OVER THE LAST FEW DAYS. CONSIDERING THESE BIASES I WOULD STILL EXPECT DAYTIME HIGHS MONDAY TO BE AROUND 60 FOR MOST OF THE CWA...WHICH IS A LITTLE LOWER THAN WHAT WE SAW TODAY. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 212 PM MST SUN DEC 7 2014 FOR THE EXTENDED PERIOD...BROAD H5 RIDGE WILL BE IN PLACE OVER THE WESTERN HALF OF THE COUNTRY FOR MUCH OF THE UPCOMING WEEK. BY THE TIME GOING INTO THE UPCOMING WEEKEND THOUGH...MODELS DO SHIFT THIS RIDGE MORE EASTWARD AS A TROUGH APPROACHES THE WEST COAST...INTO THE ROCKIES ON SATURDAY AND THEN OUT OVER THE CENTRAL/SOUTHERN PLAINS BY NEXT SUNDAY AS A CUTOFF UPPER LOW. THE LATEST GFS/ECMWF RUNS DO DIFFER ON TRACK AND PLACEMENT OF THIS SYSTEM AND WILL AFFECT PRECIPITATION POTENTIAL FOR THE FORECAST AREA. WITH THE LARGE AREA OF HIGH PRESSURE EXPECTED FOR MUCH OF THE WEEK...THE CWA WILL BE LOOKING AT HIGH TEMPS 10-15 DEGREES ABOVE NORMAL AND OVERNIGHT LOWS 5-10 DEGREES ABOVE NORMAL. 925MB TEMPS RANGING FROM +10C TO +15C THRU THE WEEK BEFORE THE TROUGH ARRIVES SATURDAY NIGHT/SUNDAY...THE AREA WILL SEE HIGHS 55-60F AND OVERNIGHT LOWS IN THE MID 20S TO LOW 30S. PRECIPITATION CHANCES FOR THE UPCOMING WEEK WILL BE NEAR ZERO AS A RESULT OF HIGH PRESSURE OVER THE AREA. THERE IS A WEAK 700 MB SHORTWAVE MOVING OFF THE ROCKIES TUESDAY NIGHT INTO WEDNESDAY THAT TRAVERSES THE REGION. MODERATE 1000-500MB RH VALUES WILL ACCOMPANY THE PASSAGE OF THIS TROUGH...BUT WITH SURFACE HIGH PRESSURE OVER AREA...LOW LEVEL AIRMASS WILL BE TOO DRY SO HAVE CONTINUED PREVIOUS FORECAST THINKING OF JUST MID LEVEL CLOUD COVER WITH THIS ONLY. THE ONLY CHANCE WILL BE OVER THE UPCOMING WEEKEND WITH THE PASSAGE OF THE UPPER LOW/TROUGH. LATEST GFS HAS THIS SYSTEM COMING OVER THE AREA OFF THE ROCKIES...WHILE THE ECMWF HAS THIS SYSTEM DROPPING OVER TEXAS. THIS WILL ALLOW FOR SYSTEM TO GRAB AMPLE MOISTURE TO PRODUCE SOME PRECIP...WHILE THE GFS IS ALMOST DRY. WHILE THE BULK OF THE ECMWF SCENARIO WILL REMAIN SOUTH OF THE CWA...STILL THINK SOME OF THIS WILL IMPACT THE CWA SO HAVE KEPT IN UP TO CHANCE POPS FOR LIGHT RAIN/SNOW. LOOKING FOR ANY LIGHT SNOW AT NIGHT SATURDAY INTO SUNDAY MORNING...AND ANY LIGHT RAIN DURING THE DAY. THE CWA AFFECTED WITH ANY OVERNIGHT LIGHT SNOW SHOULD BE LIGHT ON THE ORDER OF A COUPLE TENTHS RIGHT NOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 400 PM MST SUN DEC 7 2014 FOR KGLD AND KMCK...VFR THROUGH THE PERIOD. LIGHT NORTHWEST WINDS AT TAF ISSUANCE FORECAST TO BACK TO THE WEST AROUND 08Z THEN SOUTHWEST AROUND 19Z...SPEEDS UNDER 10KTS. BY 23Z LIGHT/VARIABLE WINDS EXPECTED. FAIR WEATHER CU POSSIBLE AFTER 19Z MONDAY OTHERWISE SOME SLIGHT INCREASE IN HIGH CLOUDS MOVING IN FROM THE NORTHWEST. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JN AVIATION...99
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
212 PM MST SUN DEC 7 2014 .SHORT TERM...(THIS AFTERNOON THROUGH MONDAY) ISSUED AT 212 PM MST SUN DEC 7 2014 LATEST WV IMAGERY AND RAP ANALYSIS SHOW RIDGING BUILDING ACROSS WESTERN US...WITH TROUGH CENTERED OVER NORTH DAKOTA AND ITS AXIS EXTENDING ACROSS EASTERN NE/KS INTO THE SOUTHERN PLAINS. AT THE SURFACE LOW PRESSURE HAS BUILD ACROSS NORTHERN COLORADO WITH A WEAK SURFACE TROUGH OVER OUR CWA. STRATUS FOG HAS ERODED AND CLEAR SKIES/DOWNSLOPE FLOW HAS LED TO TEMPS WARMING INTO THE MIDDLE 60S ACROSS NW KANSAS AND PARTS OF NORTHEAST COLORADO. SHORTWAVE RIDGE WILL TRANSITION OVER THE CWA TONIGHT AND MONDAY WITH DRY CONDITIONS AND MILD TEMPS PERSISTING. THERE IS A WEAK SHORTWAVE THAT MIGHT BRING SLIGHTLY COOLER TEMPS ALOFT AND HIGH CLOUD COVER MONDAY AFTERNOON...OTHERWISE WE SHOULD SEE LITTLE CHANGE IN SENSIBLE WEATHER OVER CWA. GOOD RADIATIONAL CONDITIONS SHOULD BE IN PLACE AND DEPENDING ON HOW LOW THE TD VALUES WILL DROP WE COULD SEE OVERNIGHT LOWS IN THE UPPER TEENS TO LOWER 20S. MET GUIDANCE WAS HINTING AT LIGHT FOG DEVELOPMENT...HOWEVER ALL OTHER 2M AND STATISTICAL GUIDANCE IS NOT SHOWING THIS...AND WITH DRY AIR ADVECTING FROM THE WEST TO SOUTHWEST I DECIDED AGAINST FOG MENTION. DESPITE SLIGHTLY COOLER TEMPS ALOFT MONDAY...THE TREND HAS BEEN FOR MOST GUIDANCE TO HAVE A COOL BIAS WITH GOOD WARMING OVER THE LAST FEW DAYS. CONSIDERING THESE BIASES I WOULD STILL EXPECT DAYTIME HIGHS MONDAY TO BE AROUND 60 FOR MOST OF THE CWA...WHICH IS A LITTLE LOWER THAN WHAT WE SAW TODAY. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 212 PM MST SUN DEC 7 2014 FOR THE EXTENDED PERIOD...BROAD H5 RIDGE WILL BE IN PLACE OVER THE WESTERN HALF OF THE COUNTRY FOR MUCH OF THE UPCOMING WEEK. BY THE TIME GOING INTO THE UPCOMING WEEKEND THOUGH...MODELS DO SHIFT THIS RIDGE MORE EASTWARD AS A TROUGH APPROACHES THE WEST COAST...INTO THE ROCKIES ON SATURDAY AND THEN OUT OVER THE CENTRAL/SOUTHERN PLAINS BY NEXT SUNDAY AS A CUTOFF UPPER LOW. THE LATEST GFS/ECMWF RUNS DO DIFFER ON TRACK AND PLACEMENT OF THIS SYSTEM AND WILL AFFECT PRECIPITATION POTENTIAL FOR THE FORECAST AREA. WITH THE LARGE AREA OF HIGH PRESSURE EXPECTED FOR MUCH OF THE WEEK...THE CWA WILL BE LOOKING AT HIGH TEMPS 10-15 DEGREES ABOVE NORMAL AND OVERNIGHT LOWS 5-10 DEGREES ABOVE NORMAL. 925MB TEMPS RANGING FROM +10C TO +15C THRU THE WEEK BEFORE THE TROUGH ARRIVES SATURDAY NIGHT/SUNDAY...THE AREA WILL SEE HIGHS 55-60F AND OVERNIGHT LOWS IN THE MID 20S TO LOW 30S. PRECIPITATION CHANCES FOR THE UPCOMING WEEK WILL BE NEAR ZERO AS A RESULT OF HIGH PRESSURE OVER THE AREA. THERE IS A WEAK 700 MB SHORTWAVE MOVING OFF THE ROCKIES TUESDAY NIGHT INTO WEDNESDAY THAT TRAVERSES THE REGION. MODERATE 1000-500MB RH VALUES WILL ACCOMPANY THE PASSAGE OF THIS TROUGH...BUT WITH SURFACE HIGH PRESSURE OVER AREA...LOW LEVEL AIRMASS WILL BE TOO DRY SO HAVE CONTINUED PREVIOUS FORECAST THINKING OF JUST MID LEVEL CLOUD COVER WITH THIS ONLY. THE ONLY CHANCE WILL BE OVER THE UPCOMING WEEKEND WITH THE PASSAGE OF THE UPPER LOW/TROUGH. LATEST GFS HAS THIS SYSTEM COMING OVER THE AREA OFF THE ROCKIES...WHILE THE ECMWF HAS THIS SYSTEM DROPPING OVER TEXAS. THIS WILL ALLOW FOR SYSTEM TO GRAB AMPLE MOISTURE TO PRODUCE SOME PRECIP...WHILE THE GFS IS ALMOST DRY. WHILE THE BULK OF THE ECMWF SCENARIO WILL REMAIN SOUTH OF THE CWA...STILL THINK SOME OF THIS WILL IMPACT THE CWA SO HAVE KEPT IN UP TO CHANCE POPS FOR LIGHT RAIN/SNOW. LOOKING FOR ANY LIGHT SNOW AT NIGHT SATURDAY INTO SUNDAY MORNING...AND ANY LIGHT RAIN DURING THE DAY. THE CWA AFFECTED WITH ANY OVERNIGHT LIGHT SNOW SHOULD BE LIGHT ON THE ORDER OF A COUPLE TENTHS RIGHT NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1039 AM MST SUN DEC 7 2014 MORNING FOG/STRATUS HAVE SHIFTED EAST OF KMCK...AND VFR CONDITIONS SHOULD PREVAIL THROUGH THE VALID TAF PERIOD AT BOTH KGLD AND KMCK. MET GUIDANCE SHOWS A BRIEF PERIOD OF 3-5SM VIS OVERNIGHT...AND WHILE GOOD RADIATIONAL CONDITIONS WILL BE IN PLACE PREVAILING WIND DIRECTION WILL TEND TO ADVECT DRY AIR INTO THE THE AREA OF BOTH TAF SITES. OTHER GUIDANCE IS SHOWING PREVAILING VFR CONDITIONS...SO I AM NOT GOING TO BUY INTO LOWER VIS AT THIS TIME. WEST TO SOUTHWEST WINDS WILL GUST AROUND 20KT AT BOTH TAF SITES THIS AFTERNOON...OTHERWISE WINDS SHOULD REMAIN BELOW 12KT THROUGH THE REST OF THE TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JN AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1108 AM CST SUN DEC 7 2014 ...UPDATE TO AVIATION... .SYNOPSIS... ISSUED AT 858 AM CST SUN DEC 7 2014 WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE TRANSITIONING EASTWARD ACROSS THE NORTHERN PLAINS. MEANWHILE, A SECONDARY UPPER LEVEL SHORTWAVE IS MOVING EAST OUT OF THE SOUTHERN ROCKIES INTO THE WESTERN HIGH PLAINS. NEAR THE SURFACE, A WEAK LEE SIDE TROUGH OF LOW PRESSURE IS LOCATED NEAR AND ALONG THE KANSAS AND COLORADO BORDER. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CST SUN DEC 7 2014 WATER VAPOR LOOP INDICATING THE THE LATEST RAP AND NAM WERE DOING A DECENT JOB ON THE TRACK OF AN UPPER LEVEL TROUGH AS IT MOVED ACROSS EASTERN COLORADO EARLIER THIS MORNING. BOTH THE RAP AND NAM MOVE THIS UPPER LEVEL FEATURE ACROSS WESTERN KANSAS BETWEEN 09Z AND 15Z SUNDAY. MODEL SOUNDINGS INDICATING MOISTURE AHEAD OF THIS UPPER LEVEL FEATURE WILL BE AT OR ABOVE THE 800MB LEVEL. IN ADDITION TO THIS AREA OF MOISTURE THE SURFACE TO 1000 TO 2000FT AGL LAYER WILL ALSO BE SATURATED EARLY THIS MORNING WITH THE DEEPER LOW LEVEL MOISTURE APPEARING TO BE NEAR AND EAST OF HIGHWAY 283. BASED ON MODEL SOUNDINGS THE DEPTH OF THE LOW LEVEL MOISTURE DOES NOT APPEAR DEEP ENOUGH TO SUPPORT DRIZZLE, HOWEVER WEAK LIFT AHEAD OF THE UPPER LEVEL TROUGH MAY GIVE RISE TO SOME SPRINKLES OR EVEN A BRIEF RAIN SHOWER...MAINLY IN NORTH CENTRAL AND SOUTH CENTRAL KANSAS. WILL THEREFORE RETAIN SMALL CHANCE FOR PRECIPITATION EARLY THIS MORNING EAST OF HIGHWAY 283. WIDESPREAD STATUS AND FOG WILL BE LIKELY EARLY THIS MORNING. AT THIS TIME THE AREA FAVORABLE FOR THE LOWER VISIBILITIES WILL BE EAST OF HIGHWAY 83 THROUGH 15Z SUNDAY GIVEN THE LOW LEVEL MOISTURE PROFILES AND BETTER UPSLOPE FLOW. BASED ON THE LATEST RAP AND HRRR ALONG WITH MOST RECENT SURFACE OBSERVATIONS THE CURRENT DENSE FOG ADVISORY HAS A GOOD HANDLE ON THIS SO NO MAJOR ADJUSTMENTS PLANNED THIS MORNING. WILL CONTINUE TO MONITOR THIS AND ADJUST ACCORDINGLY. SUBSIDENCE DEVELOPING BEHIND THE UPPER LEVEL TROUGH DURING THE LATE MORNING AND EARLY AFTERNOON WILL ALLOW FOR SOME AFTERNOON SUNSHINE TO DEVELOP. AT THIS TIME CONFIDENCE IS NOT HIGH ON HOW QUICKLY THE SKIES WILL CLEAR EAST OF DODGE CITY, HOWEVER BASED ON THE NAM AND RAP TIMING OF THE CLEARING TREND FROM WEST TO EAST ALONG WITH THE 850MB TEMPERATURES AT 21Z SUNDAY AND 00Z MONDAY THE PREVIOUS FORECAST STILL LOOKS ON TRACK. WILL CONTINUE TO FAVOR THE WARMER MAV GUIDANCE FOR HIGHS WEST OF ROUGHLY HIGHWAY 83 WHERE MORE SUN THAN CLOUDS ARE EXPECTED DURING THE AFTERNOON. FURTHER EAST FAVORED THE COOLER MET. A SURFACE BOUNDARY WILL DROP SOUTH ACROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY TONIGHT. AS THIS BOUNDARY PASSES A NORTHWESTERLY FLOW WILL DEVELOP AND DRIER AIR WILL RETURN TO WESTERN KANSAS IN THE 0-1KM AGL LEVEL. BASED ON WESTERLY WINDS AT 10 KNOTS OR LESS AND DRIER AIR ADVECTING INTO WESTERN KANSAS WILL THE PREVIOUS FORECAST WITH LOWS IN THE UPPER 20S TO LOWER 30S STILL LOOKS ON TRACK. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN DEC 7 2014 THE REST OF THE EXTENDED PERIOD IS SIMILAR TO THE LAST SEVERAL DAYS AS FAR AS TEMPERATURES ARE CONCERNED, WITH RELATIVELY LOW IMPACT SYNOPTIC SCALE WAVES EVERY COUPLE OF DAYS. DRIER AIR ALOFT WILL INFLUENCE THE AREA MONDAY ON THE HEELS OF THE EXITING UPPER JET. SUNNY SKY AND LIGHT SURFACE WINDS WILL LEAD TO TEMPERATURES MAINLY INFLUENCED BY DIURNAL INSOLATION, WHILE EASTERLY SURFACE WINDS DEVELOP OVERNIGHT INTO EARLY TUESDAY. SOME FOG OR STRATUS COULD DEVELOP IN THE FAR WESTERN SECTIONS NEAR THE COLORADO LINE, BUT THIS WOULD BE FAIRLY LIMITED AS OPPOSED THE MORE WIDESPREAD FOG OF LAST NIGHT. THE ECMWF IS MORE AGGRESSIVE THAN THE GFS IN DEVELOPING RAIN SHOWERS WITH THE POSITIVELY TILTED WAVE ON WEDNESDAY. FOR NOW LOW PROBABILITIES EXIST FOR CENTRAL KANSAS WHERE BETTER MOISTURE SHOULD BE PRESENT AS WELL AS BETTER STRETCHING DEFORMATION WITH THIS PATTERN. CONSIDERABLE UNCERTAINTY IN MESOSCALE DETAIL FOLLOWS BEYOND WEDNESDAY AS THE ECMWF AND GFS BOTH AGREE ON AN INCOMING SYNOPTIC LOW APPROACHING THE REGION WITH SOUTHERLY BOUNDARY LAYER WINDS. THE DIFFERENCES EXIST IT A FAR MORE MOIST, STRATUS AND FOG TYPE PATTERN OF THE EC AND MORE DRY BOUNDARY LAYER OR WESTERN KS WITH THE GFS WHICH CAN ALSO MAKE LARGE DIFFERENCES IN EXPECTED TEMPERATURES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1100 AM CST SUN DEC 7 2014 IFR CIGS WILL LINGER IN THE VICINITY OF KDDC AND KHYS EARLY THIS AFTERNOON AS LOW LEVEL STRATUS SLOWLY ERODES WEST TO EAST. OTHERWISE, VFR CONDTIONS WILL RETURN/PREVAIL AT ALL TAF SITES THROUGH EARLY MONDAY MORNING. SOUTHWESTERLY WINDS WILL TURN WEST TO NORTHWESTERLY 5 TO 10KT EARLY THIS EVENING AS A WEAK LEE SIDE TROUGH OF LOW PRESSURE MOVES EAST INTO WESTERN KANSAS. && .PRELIMINARY POINT TEMPS/POPS... DDC 58 31 58 32 / 30 0 0 0 GCK 60 28 58 30 / 10 0 0 0 EHA 63 33 60 36 / 10 0 0 0 LBL 60 30 59 31 / 10 0 0 0 HYS 55 29 56 28 / 20 0 0 0 P28 57 33 58 33 / 30 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JJOHNSON SHORT TERM...BURGERT LONG TERM...RUSSELL AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
902 AM CST SUN DEC 7 2014 ...UPDATE TO SYNOPSIS... .SYNOPSIS... ISSUED AT 858 AM CST SUN DEC 7 2014 WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE TRANSITIONING EASTWARD ACROSS THE NORTHERN PLAINS. MEANWHILE, A SECONDARY UPPER LEVEL SHORTWAVE IS MOVING EAST OUT OF THE SOUTHERN ROCKIES INTO THE WESTERN HIGH PLAINS. NEAR THE SURFACE, A WEAK LEE SIDE TROUGH OF LOW PRESSURE IS LOCATED NEAR AND ALONG THE KANSAS AND COLORADO BORDER. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CST SUN DEC 7 2014 WATER VAPOR LOOP INDICATING THE THE LATEST RAP AND NAM WERE DOING A DECENT JOB ON THE TRACK OF AN UPPER LEVEL TROUGH AS IT MOVED ACROSS EASTERN COLORADO EARLIER THIS MORNING. BOTH THE RAP AND NAM MOVE THIS UPPER LEVEL FEATURE ACROSS WESTERN KANSAS BETWEEN 09Z AND 15Z SUNDAY. MODEL SOUNDINGS INDICATING MOISTURE AHEAD OF THIS UPPER LEVEL FEATURE WILL BE AT OR ABOVE THE 800MB LEVEL. IN ADDITION TO THIS AREA OF MOISTURE THE SURFACE TO 1000 TO 2000FT AGL LAYER WILL ALSO BE SATURATED EARLY THIS MORNING WITH THE DEEPER LOW LEVEL MOISTURE APPEARING TO BE NEAR AND EAST OF HIGHWAY 283. BASED ON MODEL SOUNDINGS THE DEPTH OF THE LOW LEVEL MOISTURE DOES NOT APPEAR DEEP ENOUGH TO SUPPORT DRIZZLE, HOWEVER WEAK LIFT AHEAD OF THE UPPER LEVEL TROUGH MAY GIVE RISE TO SOME SPRINKLES OR EVEN A BRIEF RAIN SHOWER...MAINLY IN NORTH CENTRAL AND SOUTH CENTRAL KANSAS. WILL THEREFORE RETAIN SMALL CHANCE FOR PRECIPITATION EARLY THIS MORNING EAST OF HIGHWAY 283. WIDESPREAD STATUS AND FOG WILL BE LIKELY EARLY THIS MORNING. AT THIS TIME THE AREA FAVORABLE FOR THE LOWER VISIBILITIES WILL BE EAST OF HIGHWAY 83 THROUGH 15Z SUNDAY GIVEN THE LOW LEVEL MOISTURE PROFILES AND BETTER UPSLOPE FLOW. BASED ON THE LATEST RAP AND HRRR ALONG WITH MOST RECENT SURFACE OBSERVATIONS THE CURRENT DENSE FOG ADVISORY HAS A GOOD HANDLE ON THIS SO NO MAJOR ADJUSTMENTS PLANNED THIS MORNING. WILL CONTINUE TO MONITOR THIS AND ADJUST ACCORDINGLY. SUBSIDENCE DEVELOPING BEHIND THE UPPER LEVEL TROUGH DURING THE LATE MORNING AND EARLY AFTERNOON WILL ALLOW FOR SOME AFTERNOON SUNSHINE TO DEVELOP. AT THIS TIME CONFIDENCE IS NOT HIGH ON HOW QUICKLY THE SKIES WILL CLEAR EAST OF DODGE CITY, HOWEVER BASED ON THE NAM AND RAP TIMING OF THE CLEARING TREND FROM WEST TO EAST ALONG WITH THE 850MB TEMPERATURES AT 21Z SUNDAY AND 00Z MONDAY THE PREVIOUS FORECAST STILL LOOKS ON TRACK. WILL CONTINUE TO FAVOR THE WARMER MAV GUIDANCE FOR HIGHS WEST OF ROUGHLY HIGHWAY 83 WHERE MORE SUN THAN CLOUDS ARE EXPECTED DURING THE AFTERNOON. FURTHER EAST FAVORED THE COOLER MET. A SURFACE BOUNDARY WILL DROP SOUTH ACROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY TONIGHT. AS THIS BOUNDARY PASSES A NORTHWESTERLY FLOW WILL DEVELOP AND DRIER AIR WILL RETURN TO WESTERN KANSAS IN THE 0-1KM AGL LEVEL. BASED ON WESTERLY WINDS AT 10 KNOTS OR LESS AND DRIER AIR ADVECTING INTO WESTERN KANSAS WILL THE PREVIOUS FORECAST WITH LOWS IN THE UPPER 20S TO LOWER 30S STILL LOOKS ON TRACK. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN DEC 7 2014 THE REST OF THE EXTENDED PERIOD IS SIMILAR TO THE LAST SEVERAL DAYS AS FAR AS TEMPERATURES ARE CONCERNED, WITH RELATIVELY LOW IMPACT SYNOPTIC SCALE WAVES EVERY COUPLE OF DAYS. DRIER AIR ALOFT WILL INFLUENCE THE AREA MONDAY ON THE HEELS OF THE EXITING UPPER JET. SUNNY SKY AND LIGHT SURFACE WINDS WILL LEAD TO TEMPERATURES MAINLY INFLUENCED BY DIURNAL INSOLATION, WHILE EASTERLY SURFACE WINDS DEVELOP OVERNIGHT INTO EARLY TUESDAY. SOME FOG OR STRATUS COULD DEVELOP IN THE FAR WESTERN SECTIONS NEAR THE COLORADO LINE, BUT THIS WOULD BE FAIRLY LIMITED AS OPPOSED THE MORE WIDESPREAD FOG OF LAST NIGHT. THE ECMWF IS MORE AGGRESSIVE THAN THE GFS IN DEVELOPING RAIN SHOWERS WITH THE POSITIVELY TILTED WAVE ON WEDNESDAY. FOR NOW LOW PROBABILITIES EXIST FOR CENTRAL KANSAS WHERE BETTER MOISTURE SHOULD BE PRESENT AS WELL AS BETTER STRETCHING DEFORMATION WITH THIS PATTERN. CONSIDERABLE UNCERTAINTY IN MESOSCALE DETAIL FOLLOWS BEYOND WEDNESDAY AS THE ECMWF AND GFS BOTH AGREE ON AN INCOMING SYNOPTIC LOW APPROACHING THE REGION WITH SOUTHERLY BOUNDARY LAYER WINDS. THE DIFFERENCES EXIST IT A FAR MORE MOIST, STRATUS AND FOG TYPE PATTERN OF THE EC AND MORE DRY BOUNDARY LAYER OR WESTERN KS WITH THE GFS WHICH CAN ALSO MAKE LARGE DIFFERENCES IN EXPECTED TEMPERATURES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 556 AM CST SUN DEC 7 2014 AN UPPER LEVEL TROUGH WILL MOVE THROUGH THE REGION THIS MORNING, PRODUCING MAINLY ELEVATED VIRGA DUE TO A DRY LAYER JUST ABOVE THE BOUNDARY LAYER. IFR/LIFR FOG AND STRATUS WAS ALSO WIDESPREAD ACROSS THE AREA AFFECTING ALL THREE LOCAL TERMINALS, WHICH WILL BE THE CASE THROUGH ABOUT MID MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 58 31 58 32 / 30 0 0 0 GCK 60 28 58 30 / 10 0 0 0 EHA 63 33 60 36 / 10 0 0 0 LBL 60 30 59 31 / 10 0 0 0 HYS 55 29 56 28 / 20 0 0 0 P28 57 33 58 33 / 30 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JJOHNSON SHORT TERM...BURGERT LONG TERM...RUSSELL AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
557 AM CST SUN DEC 7 2014 ...UPDATED AVIATION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CST SUN DEC 7 2014 WATER VAPOR LOOP INDICATING THE THE LATEST RAP AND NAM WERE DOING A DECENT JOB ON THE TRACK OF AN UPPER LEVEL TROUGH AS IT MOVED ACROSS EASTERN COLORADO EARLIER THIS MORNING. BOTH THE RAP AND NAM MOVE THIS UPPER LEVEL FEATURE ACROSS WESTERN KANSAS BETWEEN 09Z AND 15Z SUNDAY. MODEL SOUNDINGS INDICATING MOISTURE AHEAD OF THIS UPPER LEVEL FEATURE WILL BE AT OR ABOVE THE 800MB LEVEL. IN ADDITION TO THIS AREA OF MOISTURE THE SURFACE TO 1000 TO 2000FT AGL LAYER WILL ALSO BE SATURATED EARLY THIS MORNING WITH THE DEEPER LOW LEVEL MOISTURE APPEARING TO BE NEAR AND EAST OF HIGHWAY 283. BASED ON MODEL SOUNDINGS THE DEPTH OF THE LOW LEVEL MOISTURE DOES NOT APPEAR DEEP ENOUGH TO SUPPORT DRIZZLE, HOWEVER WEAK LIFT AHEAD OF THE UPPER LEVEL TROUGH MAY GIVE RISE TO SOME SPRINKLES OR EVEN A BRIEF RAIN SHOWER...MAINLY IN NORTH CENTRAL AND SOUTH CENTRAL KANSAS. WILL THEREFORE RETAIN SMALL CHANCE FOR PRECIPITATION EARLY THIS MORNING EAST OF HIGHWAY 283. WIDESPREAD STATUS AND FOG WILL BE LIKELY EARLY THIS MORNING. AT THIS TIME THE AREA FAVORABLE FOR THE LOWER VISIBILITIES WILL BE EAST OF HIGHWAY 83 THROUGH 15Z SUNDAY GIVEN THE LOW LEVEL MOISTURE PROFILES AND BETTER UPSLOPE FLOW. BASED ON THE LATEST RAP AND HRRR ALONG WITH MOST RECENT SURFACE OBSERVATIONS THE CURRENT DENSE FOG ADVISORY HAS A GOOD HANDLE ON THIS SO NO MAJOR ADJUSTMENTS PLANNED THIS MORNING. WILL CONTINUE TO MONITOR THIS AND ADJUST ACCORDINGLY. SUBSIDENCE DEVELOPING BEHIND THE UPPER LEVEL TROUGH DURING THE LATE MORNING AND EARLY AFTERNOON WILL ALLOW FOR SOME AFTERNOON SUNSHINE TO DEVELOP. AT THIS TIME CONFIDENCE IS NOT HIGH ON HOW QUICKLY THE SKIES WILL CLEAR EAST OF DODGE CITY, HOWEVER BASED ON THE NAM AND RAP TIMING OF THE CLEARING TREND FROM WEST TO EAST ALONG WITH THE 850MB TEMPERATURES AT 21Z SUNDAY AND 00Z MONDAY THE PREVIOUS FORECAST STILL LOOKS ON TRACK. WILL CONTINUE TO FAVOR THE WARMER MAV GUIDANCE FOR HIGHS WEST OF ROUGHLY HIGHWAY 83 WHERE MORE SUN THAN CLOUDS ARE EXPECTED DURING THE AFTERNOON. FURTHER EAST FAVORED THE COOLER MET. A SURFACE BOUNDARY WILL DROP SOUTH ACROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY TONIGHT. AS THIS BOUNDARY PASSES A NORTHWESTERLY FLOW WILL DEVELOP AND DRIER AIR WILL RETURN TO WESTERN KANSAS IN THE 0-1KM AGL LEVEL. BASED ON WESTERLY WINDS AT 10 KNOTS OR LESS AND DRIER AIR ADVECTING INTO WESTERN KANSAS WILL THE PREVIOUS FORECAST WITH LOWS IN THE UPPER 20S TO LOWER 30S STILL LOOKS ON TRACK. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN DEC 7 2014 THE REST OF THE EXTENDED PERIOD IS SIMILAR TO THE LAST SEVERAL DAYS AS FAR AS TEMPERATURES ARE CONCERNED, WITH RELATIVELY LOW IMPACT SYNOPTIC SCALE WAVES EVERY COUPLE OF DAYS. DRIER AIR ALOFT WILL INFLUENCE THE AREA MONDAY ON THE HEELS OF THE EXITING UPPER JET. SUNNY SKY AND LIGHT SURFACE WINDS WILL LEAD TO TEMPERATURES MAINLY INFLUENCED BY DIURNAL INSOLATION, WHILE EASTERLY SURFACE WINDS DEVELOP OVERNIGHT INTO EARLY TUESDAY. SOME FOG OR STRATUS COULD DEVELOP IN THE FAR WESTERN SECTIONS NEAR THE COLORADO LINE, BUT THIS WOULD BE FAIRLY LIMITED AS OPPOSED THE MORE WIDESPREAD FOG OF LAST NIGHT. THE ECMWF IS MORE AGGRESSIVE THAN THE GFS IN DEVELOPING RAIN SHOWERS WITH THE POSITIVELY TILTED WAVE ON WEDNESDAY. FOR NOW LOW PROBABILITIES EXIST FOR CENTRAL KANSAS WHERE BETTER MOISTURE SHOULD BE PRESENT AS WELL AS BETTER STRETCHING DEFORMATION WITH THIS PATTERN. CONSIDERABLE UNCERTAINTY IN MESOSCALE DETAIL FOLLOWS BEYOND WEDNESDAY AS THE ECMWF AND GFS BOTH AGREE ON AN INCOMING SYNOPTIC LOW APPROACHING THE REGION WITH SOUTHERLY BOUNDARY LAYER WINDS. THE DIFFERENCES EXIST IT A FAR MORE MOIST, STRATUS AND FOG TYPE PATTERN OF THE EC AND MORE DRY BOUNDARY LAYER OR WESTERN KS WITH THE GFS WHICH CAN ALSO MAKE LARGE DIFFERENCES IN EXPECTED TEMPERATURES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 556 AM CST SUN DEC 7 2014 AN UPPER LEVEL TROUGH WILL MOVE THROUGH THE REGION THIS MORNING, PRODUCING MAINLY ELEVATED VIRGA DUE TO A DRY LAYER JUST ABOVE THE BOUNDARY LAYER. IFR/LIFR FOG AND STRATUS WAS ALSO WIDESPREAD ACROSS THE AREA AFFECTING ALL THREE LOCAL TERMINALS, WHICH WILL BE THE CASE THROUGH ABOUT MID MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 58 31 58 32 / 10 0 0 0 GCK 60 28 58 30 / 10 0 0 0 EHA 63 33 60 36 / 0 0 0 0 LBL 60 30 59 31 / 10 0 0 0 HYS 55 29 56 28 / 10 0 0 0 P28 57 33 58 33 / 10 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ030-031- 045-046-064>066-078>081-088>090. && $$ SHORT TERM...BURGERT LONG TERM...RUSSELL AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
344 AM MST SUN DEC 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM MST SUN DEC 7 2014 SHORT TERM FORECAST CONCERNS ARE THE POSSIBILITY OF FOG AND LOW CLOUDS EXPANDING ACROSS PORTIONS OF THE FORECAST AREA EARLY THIS MORNING AND THE POSSIBILITY OF FOG DEVELOPING AGAIN OVER PORTIONS OF THE FORECAST AREA EACH OF THE NEXT COUPLE OF DAYS. WIDESPREAD LOW CLOUDS AND FOG ARE PRESENT OVER CENTRAL KANSAS AND EXTEND NORTH INTO SOUTHERN NEBRASKA. THE WESTERN PERIPHERY OF THIS AREA HAS EXTENDED BACK INTO NORTHWEST KANSAS...BUT HAS NOT BEEN AS EXTENSIVE AS PREVIOUSLY EXPECTED. HAVE TRIMMED BACK THE COVERAGE FIRST THING THIS MORNING...BUT HAVE ALSO KEPT IT IN PLACE OVER THE FAR EAST A LITTLE LONGER UNTIL THE UPPER TROUGH MOVES EAST AND HELPS SWEEP OUT THE HIGH CLOUDS AND ALSO DRAGS THE SURFACE TROUGH ACROSS THE FORECAST AREA. WITH CLEARING EXPECTED EARLY OVER THE WEST WITH A DELAY OVER THE EAST...WILL LIKELY SEE HIGHS AROUND 60 IN THE WEST WITH HIGHS STRUGGLING TO REACH THE MIDDLE 50S OUT EAST WITH GUSTY NORTHWEST WINDS MOVING IN MY MID DAY. CONDITIONS WILL REMAIN DRY WITH TEMPERATURES WARMER THAN AVERAGE THROUGH TUESDAY WITH GENERAL RIDGING ALOFT OVER THE ROCKIES AND HIGH PLAINS. THE NEXT BEST POSSIBILITY OF FOG ACROSS THE REGION WILL BE TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING. DEWPOINTS WELL INTO THE 30S ARE EXPECTED IN THE RETURN FLOW AROUND THE SURFACE HIGH MOVING INTO THE PLAINS STATES IN THE CONVERGENT AREA AHEAD OF THE SURFACE TROUGH DEEPENING ALONG THE FRONT RANGE. HAVE LEFT ANY FOG OUT FOR NOW AS THEE ARE SOME DIFFERENCES SHOWING UP BETWEEN THE ECMWF AND NAM AND GFS AT THAT TIME THAT PUT A DAMPER ON CONFIDENCE. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 230 AM MST SUN DEC 7 2014 A SIGNIFICANT WEATHER SYSTEM MAY AFFECT THE HIGH PLAINS LATE NEXT WEEKEND. THIS SYSTEM IS THE MAIN EXTENDED FORECAST CONCERN AND THE MAJORITY OF THIS DISCUSSION WILL FOCUS ON THE POSSIBILITIES. FOR WEDNESDAY THROUGH SATURDAY...RIDGE OF HIGH PRESSURE ALOFT SHALL DOMINATE THE WEATHER PATTERN. OVERALL...STILL ANTICIPATING VERY WARM TEMPERATURES FOR THIS TIME OF YEAR. HOWEVER...FORECAST GUIDANCE HAS LOWERED TEMPERATURES SLIGHTLY. UPON FURTHER REVIEW...IT APPEARS THE MODELS ARE STRUGGLING WITH MOISTURE ADVECTION FROM THE SOUTH AND SUBSEQUENT LOW CLOUDS...ESPECIALLY OVER THE EASTERN FORECAST REGION. FELT CONFIDENT ENOUGH IN CONTINUING THE WARM FORECAST OVER THE WEST AS DRIER AIR SHOULD REMAIN IN PLACE WITH DOWNSLOPE FLOW FROM THE FRONT RANGE. FURTHER EAST...MORNING FOG/STATUS AND HIGHER MOISTURE CONTENT OF ATMOSPHERE MAY LIMIT DAYTIME WARMING...THUS LEADING TO COOLER HIGH TEMPERATURES. CONCERNING NEXT WEEKENDS SYSTEM...MODELS HAVE BEEN CONSISTENT IN SHOWING AT LEAST A STRONG DISTURBANCE MOVING THROUGH THE SOUTHWESTERN UNITED STATES SATURDAY. THIS SYSTEM THEN EJECTS NORTHEAST ACROSS THE HIGH PLAINS SUNDAY. MANY ASPECTS OF THIS SYSTEM STILL NEED TO BE RESOLVED INCLUDING STRENGTH...TIMING AND MOST PROBLEMATIC...PATH THIS SYSTEM TRAVELS. FORECAST ENSEMBLES INDICATE A SIGNIFICANT AMOUNT OF SPREAD BETWEEN ENSEMBLE MEMBERS. THE ENSEMBLE MEAN INDICATES A LARGE...OPEN TROUGH PASSING THROUGH WHILE SOME OF THE MEMBERS AND THE 00Z OPERATIONAL GFS INDICATE A STRONG...CLOSED LOW. THE OPERATIONAL EUROPEAN MODEL INDICATES THE OPEN THOUGH SOLUTION SHOWN BY THE ENSEMBLE MEAN. THE EUROPEAN ENSEMBLE ALSO SUGGESTS THE OPEN TROUGH SOLUTION BUT INDICATES A HIGH VARIABILITY BETWEEN SOLUTIONS. THE CLOSED LOW SOLUTION/POSSIBILITY IS EYE-OPENING IN THAT IT IS A CLIMATOLOGICALLY FAVORABLE PATTERN FOR OUR REGION TO RECEIVE A SIGNIFICANT WINTER STORM...POSSIBLY EVEN A BLIZZARD. THAT BEING SAID...THERE IS JUST TOO MUCH VARIABILITY BETWEEN INDIVIDUAL MODELS AND MODEL RUNS TO REALLY BEGIN HIGHLIGHTING A POTENTIAL HIGH-IMPACT STORM. FOR EXAMPLE...YESTERDAYS 00Z GFS RUN SUGGESTED A STRONG SYSTEM GOING SOUTH OF THE REGION...ACROSS THE BIG BEND COUNTRY OF TEXAS. THE 06Z RUN SHOWED A STRONG SYSTEM EJECTING OVER THE COLORADO FRONT RANGE AND HEADING TOWARDS RAPID CITY...WELL NORTH OF THE FORECAST AREA. TODAYS 00Z OPERATIONAL GFS RUN BRINGS THE STRONG LOW OVER THE TEXAS AND OKLAHOMA PANHANDLES WITH SIGNIFICANT AMOUNTS OF PRECIPITATION ACROSS WESTERN KANSAS. AS OF RIGHT NOW...AM FAIRLY CONFIDENT THAT A COLD FRONT WILL PASS THROUGH AND WE HAVE A DECENT CHANCE AT SOME PRECIPITATION. HOW MUCH...WHAT PRECIPITATION TYPE AND IF HIGH WINDS WILL ACCOMPANY THIS SYSTEM IS EXTREMELY DIFFICULT TO PINPOINT AS OF RIGHT NOW DUE TO THE DIFFERING POSSIBILITIES ON SYSTEM EVOLUTION. IT IS SOMETHING TO WATCH FORECASTS UPDATES SO STAY TUNED! && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1000 PM MST SAT DEC 6 2014 KGLD...SOUTH WIND AROUND 15KTS AT TAF ISSUANCE WILL VEER TO THE SOUTH AND DECREASE TO 10KTS BY 08Z UNDER A VFR OVERCAST SKY. STRATUS/BR MAY REACH THE TERMINAL FROM THE EAST/SOUTHEAST AROUND 08Z WITH IFR CIGS EXPECTED FROM 08Z-11Z WITH WINDS FROM THE SOUTH AROUND 10KTS. AROUND 12Z WINDS VEER TO THE SOUTHWEST 5-10KTS PUSHING THE STRATUS SLOWLY EAST ALLOWING FOR VFR CONDITIONS TO RETURN. WINDS THEN GO WEST UNDER 10KTS AROUND 15Z THEN SHIFT TO THE NORTHWEST 12G20KT POSSIBLY A BIT HIGHER IN THE 18Z-22Z TIMEFRAME UNDER JUST A FEW FAIR WEATHER CLOUDS. BY 23Z WINDS DISSIPATE TO 5KTS OR SO BY 23Z THEN BACK TO THE WEST AT SIMILAR SPEEDS AROUND 05Z. KMCK...SOUTHEAST WIND NEAR 10KT AT TAF ISSUANCE UNDER A VFR OVERCAST SKY. STRATUS/DRIZZLE/BR WITH IFR CONDITIONS AND POSSIBLY VLIFR CONDITIONS WITH VIS 1/2SM IN FG/DZ REACH THE TERMINAL FROM THE EAST AROUND 09Z AND CONTINUE THROUGH 17Z BEFORE WINDS VEER AROUND TO THE NORTHWEST NEAR 10KTS IN THE 17Z-20Z TIMEFRAME. THIS WILL SCOUR OUT THE STRATUS PRODUCING VFR CONDITIONS FROM 17Z THROUGH THE REST OF THE TAF PERIOD. IT SHOULD BE NOTED THAT IN THESE SCENARIOS THAT HIGH RESOLUTION MODELS OCCASIONALLY DONT PUSH THE STRATUS FAR ENOUGH WEST...BY AT LEAST ONE ROW OF COUNTIES. IF THIS VERIFIES STRATUS/BR (POSSIBLY FG WITH VLIFR CONDITIONS) MAY TAKE UP TO AN ADDITIONAL 3 HOURS TO MOVE OUT OF BOTH TERMINALS. WITH A THICK OVERCAST SKY HARD TO WATCH STRATUS PROGRESSION ON SATELLITE IMAGERY SO WILL HAVE TO WATCH METARS AND HOURLY MODEL UPDATES FROM THE RUC AND HRRR. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...LOCKHART LONG TERM...RRH AVIATION...99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
354 AM CST SUN DEC 7 2014 ...UPDATED LONG TERM... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CST SUN DEC 7 2014 WATER VAPOR LOOP INDICATING THE THE LATEST RAP AND NAM WERE DOING A DECENT JOB ON THE TRACK OF AN UPPER LEVEL TROUGH AS IT MOVED ACROSS EASTERN COLORADO EARLIER THIS MORNING. BOTH THE RAP AND NAM MOVE THIS UPPER LEVEL FEATURE ACROSS WESTERN KANSAS BETWEEN 09Z AND 15Z SUNDAY. MODEL SOUNDINGS INDICATING MOISTURE AHEAD OF THIS UPPER LEVEL FEATURE WILL BE AT OR ABOVE THE 800MB LEVEL. IN ADDITION TO THIS AREA OF MOISTURE THE SURFACE TO 1000 TO 2000FT AGL LAYER WILL ALSO BE SATURATED EARLY THIS MORNING WITH THE DEEPER LOW LEVEL MOISTURE APPEARING TO BE NEAR AND EAST OF HIGHWAY 283. BASED ON MODEL SOUNDINGS THE DEPTH OF THE LOW LEVEL MOISTURE DOES NOT APPEAR DEEP ENOUGH TO SUPPORT DRIZZLE, HOWEVER WEAK LIFT AHEAD OF THE UPPER LEVEL TROUGH MAY GIVE RISE TO SOME SPRINKLES OR EVEN A BRIEF RAIN SHOWER...MAINLY IN NORTH CENTRAL AND SOUTH CENTRAL KANSAS. WILL THEREFORE RETAIN SMALL CHANCE FOR PRECIPITATION EARLY THIS MORNING EAST OF HIGHWAY 283. WIDESPREAD STATUS AND FOG WILL BE LIKELY EARLY THIS MORNING. AT THIS TIME THE AREA FAVORABLE FOR THE LOWER VISIBILITIES WILL BE EAST OF HIGHWAY 83 THROUGH 15Z SUNDAY GIVEN THE LOW LEVEL MOISTURE PROFILES AND BETTER UPSLOPE FLOW. BASED ON THE LATEST RAP AND HRRR ALONG WITH MOST RECENT SURFACE OBSERVATIONS THE CURRENT DENSE FOG ADVISORY HAS A GOOD HANDLE ON THIS SO NO MAJOR ADJUSTMENTS PLANNED THIS MORNING. WILL CONTINUE TO MONITOR THIS AND ADJUST ACCORDINGLY. SUBSIDENCE DEVELOPING BEHIND THE UPPER LEVEL TROUGH DURING THE LATE MORNING AND EARLY AFTERNOON WILL ALLOW FOR SOME AFTERNOON SUNSHINE TO DEVELOP. AT THIS TIME CONFIDENCE IS NOT HIGH ON HOW QUICKLY THE SKIES WILL CLEAR EAST OF DODGE CITY, HOWEVER BASED ON THE NAM AND RAP TIMING OF THE CLEARING TREND FROM WEST TO EAST ALONG WITH THE 850MB TEMPERATURES AT 21Z SUNDAY AND 00Z MONDAY THE PREVIOUS FORECAST STILL LOOKS ON TRACK. WILL CONTINUE TO FAVOR THE WARMER MAV GUIDANCE FOR HIGHS WEST OF ROUGHLY HIGHWAY 83 WHERE MORE SUN THAN CLOUDS ARE EXPECTED DURING THE AFTERNOON. FURTHER EAST FAVORED THE COOLER MET. A SURFACE BOUNDARY WILL DROP SOUTH ACROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY TONIGHT. AS THIS BOUNDARY PASSES A NORTHWESTERLY FLOW WILL DEVELOP AND DRIER AIR WILL RETURN TO WESTERN KANSAS IN THE 0-1KM AGL LEVEL. BASED ON WESTERLY WINDS AT 10 KNOTS OR LESS AND DRIER AIR ADVECTING INTO WESTERN KANSAS WILL THE PREVIOUS FORECAST WITH LOWS IN THE UPPER 20S TO LOWER 30S STILL LOOKS ON TRACK. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN DEC 7 2014 THE REST OF THE EXTENDED PERIOD IS SIMILAR TO THE LAST SEVERAL DAYS AS FAR AS TEMPERATURES ARE CONCERNED, WITH RELATIVELY LOW IMPACT SYNOPTIC SCALE WAVES EVERY COUPLE OF DAYS. DRIER AIR ALOFT WILL INFLUENCE THE AREA MONDAY ON THE HEELS OF THE EXITING UPPER JET. SUNNY SKY AND LIGHT SURFACE WINDS WILL LEAD TO TEMPERATURES MAINLY INFLUENCED BY DIURNAL INSOLATION, WHILE EASTERLY SURFACE WINDS DEVELOP OVERNIGHT INTO EARLY TUESDAY. SOME FOG OR STRATUS COULD DEVELOP IN THE FAR WESTERN SECTIONS NEAR THE COLORADO LINE, BUT THIS WOULD BE FAIRLY LIMITED AS OPPOSED THE MORE WIDESPREAD FOG OF LAST NIGHT. THE ECMWF IS MORE AGGRESSIVE THAN THE GFS IN DEVELOPING RAIN SHOWERS WITH THE POSITIVELY TILTED WAVE ON WEDNESDAY. FOR NOW LOW PROBABILITIES EXIST FOR CENTRAL KANSAS WHERE BETTER MOISTURE SHOULD BE PRESENT AS WELL AS BETTER STRETCHING DEFORMATION WITH THIS PATTERN. CONSIDERABLE UNCERTAINTY IN MESOSCALE DETAIL FOLLOWS BEYOND WEDNESDAY AS THE ECMWF AND GFS BOTH AGREE ON AN INCOMING SYNOPTIC LOW APPROACHING THE REGION WITH SOUTHERLY BOUNDARY LAYER WINDS. THE DIFFERENCES EXIST IT A FAR MORE MOIST, STRATUS AND FOG TYPE PATTERN OF THE EC AND MORE DRY BOUNDARY LAYER OR WESTERN KS WITH THE GFS WHICH CAN ALSO MAKE LARGE DIFFERENCES IN EXPECTED TEMPERATURES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1120 PM CST SAT DEC 6 2014 LIFR CONDITIONS CAN BE EXPECTED AT DDC AND HYS OVERNIGHT AS A MOIST SOUTHEASTERLY UPSLOPE FLOW CONTINUES AT 10 TO 15 KNOTS ACROSS WESTERN KANSAS. CEILINGS AND VISIBILITIES AT GCK ARE ALSO EXPECTED TO FALL BACK INTO THE LOW IFR/LIFR CATEGORY BY 08Z BASED ON THE LATEST HRRR, RAP AND NAM. AN UPPER LEVEL DISTURBANCE WILL CROSS THE CENTRAL PLAINS EARLY SUNDAY AND A SURFACE BOUNDARY, LOCATED NEAR THE COLORADO BORDER AT 05Z, WILL INTO WESTERN KANSAS. AS THE LOW LEVEL WINDS VEER TO THE SOUTHWEST THE VISIBILITIES AND CEILINGS WILL IMPROVE. CONFIDENCE IS NOT HIGH ON TIMING BUT GIVEN THE LATEST HRRR, RAP AND NAM WILL FAVOR IFR/MVFR AT GCK AND HYS BETWEEN 12 AND 15Z SUNDAY. FOR DDC WILL KEEP IFR CONDITIONS UNTIL LATE MORNING. VFR CONDITIONS ARE EXPECTED TO DEVELOP IN THE AFTERNOON AS SUBSIDENCE DEVELOPS BEHIND THE UPPER LEVEL TROUGH. && .PRELIMINARY POINT TEMPS/POPS... DDC 58 31 58 32 / 10 0 0 0 GCK 60 28 58 30 / 10 0 0 0 EHA 63 33 60 36 / 0 0 0 0 LBL 60 30 59 31 / 10 0 0 0 HYS 55 29 56 28 / 10 0 0 0 P28 57 33 58 33 / 10 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ030-031- 043>046-063>066-076>081-086>090. && $$ SHORT TERM...BURGERT LONG TERM...RUSSELL AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
230 AM MST SUN DEC 7 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 207 PM MST SAT DEC 6 2014 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW PROGRESSIVE TROUGH-RIDGE TROUGH PATTERN ACROSS US WITH RIDGE CURRENTLY EXTENDING FROM SOUTH CENTRAL CANADA ACROSS THE CENTRAL PLAINS. SW FLOW IS IN PLACE FROM THE FOUR CORNERS REGION AND INTO WESTERN KS WITH SHORTWAVE TROUGH MOVING OUT OF THE GREAT BASIN TOWARDS THE CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE OVER EASTERN COLORADO WITH SOUTHERLY FLOW ACROSS OUR CWA. AS SHORTWAVE TROUGH TRANSITIONS EASTWARD STATIONARY FRONT/BAROCLINIC ZONE WITH SHIFT NORTH AND EAST ALLOWING FOR SOUTHEAST MOISTURE RETURN INTO THE EASTERN HALF OF OUR CWA. MIDLEVEL MOISTURE/UPPER LEVEL FORCING COULD ALLOW FOR A BRIEF PERIOD OF LIGHT RAIN SHOWERS LATE TONIGHT...HOWEVER MODEL SOUNDINGS INDICATE A SIGNIFICANT DRY LAYER WOULD LIKELY PREVENT ANY ELEVATED PRECIPITATION FROM REACHING THE SURFACE. MAIN CONCERN WILL BE POTENTIAL FOR DENSE FOG DEVELOPMENT AND POTENTIAL FOR DRIZZLE ACROSS EASTERN CWA LATE TONIGHT THROUGH SUNDAY MORNING. NAM/RAP SHOW WEAK SURFACE CONVERGENCE IN PROXIMITY OF BAROCLINIC ZONE WHICH COULD PROVIDE ENOUGH LIFT WITHIN SHALLOW SATURATED LAYER TO ALLOW FOR DRIZZLE DEVELOPMENT. THIS COULD BE MORE OF A STRATUS/DRIZZLE EVENT...THOUGH CONSIDERING THE GOOD MOISTURE RETURN LOWER VISIBILITIES ARE CERTAINLY POSSIBLE. HIGH CLOUDS HAVE ALREADY BEEN HAVING AN IMPACT ON MIXING THIS AFTERNOON...AND WITH THICKENING/LOWERING CLOUDS THOUGH THE NIGHT (ALONG WITH TD VALUES INCREASING TO MID/UPPER 30S IN THE EAST)...RADIATIONAL COOLING WILL BE LIMITED. NOT ONLY COULD THIS LIMIT DENSE FOG DEVELOPMENT...BUT THIS MAKES FREEZING FOG/FREEZING DRIZZLE UNLIKELY AT THIS POINT. AT THIS POINT HOLDING OFF ON HIGHLIGHTS SEEMS THE BEST COURSE. WITH SHIFT BACK TO SW FLOW AS SHORTWAVE RIDGING BUILDS BACK INTO THE ROCKIES THERE SHOULD BE RAPID IMPROVEMENT IN CONDITIONS SUNDAY.CLEARING SKIES AND WAA THROUGH THE AFTERNOON SHOULD ALLOW HIGHS TO WARM TO AROUND 60F...THOUGH STRATUS MAY HOLD ON A LITTLE LONGER IN OUR EASTERN CWA LIMITING DAYTIME MIXING AND KEEPING HIGHS IN THE LOW TO MID 50S. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 230 AM MST SUN DEC 7 2014 A SIGNIFICANT WEATHER SYSTEM MAY AFFECT THE HIGH PLAINS LATE NEXT WEEKEND. THIS SYSTEM IS THE MAIN EXTENDED FORECAST CONCERN AND THE MAJORITY OF THIS DISCUSSION WILL FOCUS ON THE POSSIBILITIES. FOR WEDNESDAY THROUGH SATURDAY...RIDGE OF HIGH PRESSURE ALOFT SHALL DOMINATE THE WEATHER PATTERN. OVERALL...STILL ANTICIPATING VERY WARM TEMPERATURES FOR THIS TIME OF YEAR. HOWEVER...FORECAST GUIDANCE HAS LOWERED TEMPERATURES SLIGHTLY. UPON FURTHER REVIEW...IT APPEARS THE MODELS ARE STRUGGLING WITH MOISTURE ADVECTION FROM THE SOUTH AND SUBSEQUENT LOW CLOUDS...ESPECIALLY OVER THE EASTERN FORECAST REGION. FELT CONFIDENT ENOUGH IN CONTINUING THE WARM FORECAST OVER THE WEST AS DRIER AIR SHOULD REMAIN IN PLACE WITH DOWNSLOPE FLOW FROM THE FRONT RANGE. FURTHER EAST...MORNING FOG/STATUS AND HIGHER MOISTURE CONTENT OF ATMOSPHERE MAY LIMIT DAYTIME WARMING...THUS LEADING TO COOLER HIGH TEMPERATURES. CONCERNING NEXT WEEKENDS SYSTEM...MODELS HAVE BEEN CONSISTENT IN SHOWING AT LEAST A STRONG DISTURBANCE MOVING THROUGH THE SOUTHWESTERN UNITED STATES SATURDAY. THIS SYSTEM THEN EJECTS NORTHEAST ACROSS THE HIGH PLAINS SUNDAY. MANY ASPECTS OF THIS SYSTEM STILL NEED TO BE RESOLVED INCLUDING STRENGTH...TIMING AND MOST PROBLEMATIC...PATH THIS SYSTEM TRAVELS. FORECAST ENSEMBLES INDICATE A SIGNIFICANT AMOUNT OF SPREAD BETWEEN ENSEMBLE MEMBERS. THE ENSEMBLE MEAN INDICATES A LARGE...OPEN TROUGH PASSING THROUGH WHILE SOME OF THE MEMBERS AND THE 00Z OPERATIONAL GFS INDICATE A STRONG...CLOSED LOW. THE OPERATIONAL EUROPEAN MODEL INDICATES THE OPEN THOUGH SOLUTION SHOWN BY THE ENSEMBLE MEAN. THE EUROPEAN ENSEMBLE ALSO SUGGESTS THE OPEN TROUGH SOLUTION BUT INDICATES A HIGH VARIABILITY BETWEEN SOLUTIONS. THE CLOSED LOW SOLUTION/POSSIBILITY IS EYE-OPENING IN THAT IT IS A CLIMATOLOGICALLY FAVORABLE PATTERN FOR OUR REGION TO RECEIVE A SIGNIFICANT WINTER STORM...POSSIBLY EVEN A BLIZZARD. THAT BEING SAID...THERE IS JUST TOO MUCH VARIABILITY BETWEEN INDIVIDUAL MODELS AND MODEL RUNS TO REALLY BEGIN HIGHLIGHTING A POTENTIAL HIGH-IMPACT STORM. FOR EXAMPLE...YESTERDAYS 00Z GFS RUN SUGGESTED A STRONG SYSTEM GOING SOUTH OF THE REGION...ACROSS THE BIG BEND COUNTRY OF TEXAS. THE 06Z RUN SHOWED A STRONG SYSTEM EJECTING OVER THE COLORADO FRONT RANGE AND HEADING TOWARDS RAPID CITY...WELL NORTH OF THE FORECAST AREA. TODAYS 00Z OPERATIONAL GFS RUN BRINGS THE STRONG LOW OVER THE TEXAS AND OKLAHOMA PANHANDLES WITH SIGNIFICANT AMOUNTS OF PRECIPITATION ACROSS WESTERN KANSAS. AS OF RIGHT NOW...AM FAIRLY CONFIDENT THAT A COLD FRONT WILL PASS THROUGH AND WE HAVE A DECENT CHANCE AT SOME PRECIPITATION. HOW MUCH...WHAT PRECIPITATION TYPE AND IF HIGH WINDS WILL ACCOMPANY THIS SYSTEM IS EXTREMELY DIFFICULT TO PINPOINT AS OF RIGHT NOW DUE TO THE DIFFERING POSSIBILITIES ON SYSTEM EVOLUTION. IT IS SOMETHING TO WATCH FORECASTS UPDATES SO STAY TUNED! && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1000 PM MST SAT DEC 6 2014 KGLD...SOUTH WIND AROUND 15KTS AT TAF ISSUANCE WILL VEER TO THE SOUTH AND DECREASE TO 10KTS BY 08Z UNDER A VFR OVERCAST SKY. STRATUS/BR MAY REACH THE TERMINAL FROM THE EAST/SOUTHEAST AROUND 08Z WITH IFR CIGS EXPECTED FROM 08Z-11Z WITH WINDS FROM THE SOUTH AROUND 10KTS. AROUND 12Z WINDS VEER TO THE SOUTHWEST 5-10KTS PUSHING THE STRATUS SLOWLY EAST ALLOWING FOR VFR CONDITIONS TO RETURN. WINDS THEN GO WEST UNDER 10KTS AROUND 15Z THEN SHIFT TO THE NORTHWEST 12G20KT POSSIBLY A BIT HIGHER IN THE 18Z-22Z TIMEFRAME UNDER JUST A FEW FAIR WEATHER CLOUDS. BY 23Z WINDS DISSIPATE TO 5KTS OR SO BY 23Z THEN BACK TO THE WEST AT SIMILAR SPEEDS AROUND 05Z. KMCK...SOUTHEAST WIND NEAR 10KT AT TAF ISSUANCE UNDER A VFR OVERCAST SKY. STRATUS/DRIZZLE/BR WITH IFR CONDITIONS AND POSSIBLY VLIFR CONDITIONS WITH VIS 1/2SM IN FG/DZ REACH THE TERMINAL FROM THE EAST AROUND 09Z AND CONTINUE THROUGH 17Z BEFORE WINDS VEER AROUND TO THE NORTHWEST NEAR 10KTS IN THE 17Z-20Z TIMEFRAME. THIS WILL SCOUR OUT THE STRATUS PRODUCING VFR CONDITIONS FROM 17Z THROUGH THE REST OF THE TAF PERIOD. IT SHOULD BE NOTED THAT IN THESE SCENARIOS THAT HIGH RESOLUTION MODELS OCCASIONALLY DONT PUSH THE STRATUS FAR ENOUGH WEST...BY AT LEAST ONE ROW OF COUNTIES. IF THIS VERIFIES STRATUS/BR (POSSIBLY FG WITH VLIFR CONDITIONS) MAY TAKE UP TO AN ADDITIONAL 3 HOURS TO MOVE OUT OF BOTH TERMINALS. WITH A THICK OVERCAST SKY HARD TO WATCH STRATUS PROGRESSION ON SATELLITE IMAGERY SO WILL HAVE TO WATCH METARS AND HOURLY MODEL UPDATES FROM THE RUC AND HRRR. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...RRH AVIATION...99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
204 AM CST SUN DEC 7 2014 ...UPDATED SHORT TERM DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CST SUN DEC 7 2014 WATER VAPOR LOOP INDICATING THE THE LATEST RAP AND NAM WERE DOING A DECENT JOB ON THE TRACK OF AN UPPER LEVEL TROUGH AS IT MOVED ACROSS EASTERN COLORADO EARLIER THIS MORNING. BOTH THE RAP AND NAM MOVE THIS UPPER LEVEL FEATURE ACROSS WESTERN KANSAS BETWEEN 09Z AND 15Z SUNDAY. MODEL SOUNDINGS INDICATING MOISTURE AHEAD OF THIS UPPER LEVEL FEATURE WILL BE AT OR ABOVE THE 800MB LEVEL. IN ADDITION TO THIS AREA OF MOISTURE THE SURFACE TO 1000 TO 2000FT AGL LAYER WILL ALSO BE SATURATED EARLY THIS MORNING WITH THE DEEPER LOW LEVEL MOISTURE APPEARING TO BE NEAR AND EAST OF HIGHWAY 283. BASED ON MODEL SOUNDINGS THE DEPTH OF THE LOW LEVEL MOISTURE DOES NOT APPEAR DEEP ENOUGH TO SUPPORT DRIZZLE, HOWEVER WEAK LIFT AHEAD OF THE UPPER LEVEL TROUGH MAY GIVE RISE TO SOME SPRINKLES OR EVEN A BRIEF RAIN SHOWER...MAINLY IN NORTH CENTRAL AND SOUTH CENTRAL KANSAS. WILL THEREFORE RETAIN SMALL CHANCE FOR PRECIPITATION EARLY THIS MORNING EAST OF HIGHWAY 283. WIDESPREAD STATUS AND FOG WILL BE LIKELY EARLY THIS MORNING. AT THIS TIME THE AREA FAVORABLE FOR THE LOWER VISIBILITIES WILL BE EAST OF HIGHWAY 83 THROUGH 15Z SUNDAY GIVEN THE LOW LEVEL MOISTURE PROFILES AND BETTER UPSLOPE FLOW. BASED ON THE LATEST RAP AND HRRR ALONG WITH MOST RECENT SURFACE OBSERVATIONS THE CURRENT DENSE FOG ADVISORY HAS A GOOD HANDLE ON THIS SO NO MAJOR ADJUSTMENTS PLANNED THIS MORNING. WILL CONTINUE TO MONITOR THIS AND ADJUST ACCORDINGLY. SUBSIDENCE DEVELOPING BEHIND THE UPPER LEVEL TROUGH DURING THE LATE MORNING AND EARLY AFTERNOON WILL ALLOW FOR SOME AFTERNOON SUNSHINE TO DEVELOP. AT THIS TIME CONFIDENCE IS NOT HIGH ON HOW QUICKLY THE SKIES WILL CLEAR EAST OF DODGE CITY, HOWEVER BASED ON THE NAM AND RAP TIMING OF THE CLEARING TREND FROM WEST TO EAST ALONG WITH THE 850MB TEMPERATURES AT 21Z SUNDAY AND 00Z MONDAY THE PREVIOUS FORECAST STILL LOOKS ON TRACK. WILL CONTINUE TO FAVOR THE WARMER MAV GUIDANCE FOR HIGHS WEST OF ROUGHLY HIGHWAY 83 WHERE MORE SUN THAN CLOUDS ARE EXPECTED DURING THE AFTERNOON. FURTHER EAST FAVORED THE COOLER MET. A SURFACE BOUNDARY WILL DROP SOUTH ACROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY TONIGHT. AS THIS BOUNDARY PASSES A NORTHWESTERLY FLOW WILL DEVELOP AND DRIER AIR WILL RETURN TO WESTERN KANSAS IN THE 0-1KM AGL LEVEL. BASED ON WESTERLY WINDS AT 10 KNOTS OR LESS AND DRIER AIR ADVECTING INTO WESTERN KANSAS WILL THE PREVIOUS FORECAST WITH LOWS IN THE UPPER 20S TO LOWER 30S STILL LOOKS ON TRACK. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 232 PM CST SAT DEC 6 2014 A MILD PERIOD IS FORECAST AHEAD OF THE NEXT UPPER LEVEL TROUGH AND STORM SYSTEM PUSHING INTO THE WESTERN U.S. BY NEXT WEEKEND. GFS ENSEMBLES ARE A BIT MORE AGGRESSIVE AND STRONGER THAN THE EUROPEAN MODEL WITH THIS NEXT SYSTEM THAT COULD BE A WEATHER MAKER INTO THE PLAINS AROUND THE 15TH AND 16TH OF DECEMBER. FOR MONDAY, LIGHT AND VARIABLE WINDS BECOME LIGHT SOUTHEASTERLY WITH HIGHS IN THE MID AND UPPER 50S. FOR TUESDAY, SOUTHERLY WINDS INCREASE AHEAD OF A LEE TROUGH, WITH HIGHS AGAIN FROM 55 TO 60. ON WEDNESDAY, AN UPPER LEVEL TROUGH BRINGS A COLD FRONT ACROSS WESTERN KANSAS IN THE MORNING INTO THE AFTERNOON. THERE COULD BE CONSIDERABLE LOW CLOUDS AND SOME FOG AHEAD OF THIS FRONT ON WEDNESDAY AS DEWPOINTS RISE INTO THE 40S. SOME LIGHT RAIN SHOWERS MAY BREAK OUT IN PARTS OF SOUTH CENTRAL KANSAS, MAINLY EAST OF DODGE CITY AHEAD OF THE COLD FRONT. HIGHS ON WEDNESDAY WILL CONTINUE TO BE IN THE 50S. OVERNIGHT LOWS MONDAY MORNING WILL RANGE FROM THE MID AND UPPER 20S ACROSS SOUTHWEST KANSAS TO THE LOW TO MID 30S NEAR MEDICINE LODGE. LOWS THEN WARM BACK INTO THE MID 30S INTO THURSDAY MORNING. FOR THE PERIOD OF THURSDAY INTO SATURDAY, UPPER LEVEL RIDGING AND WARMING MOVE INTO THE PLAINS AHEAD OF THE NEXT STORM SYSTEM PUSHING INTO THE WESTERN U.S. HIGHS WILL BE MILD AND IN THE MID 50S TO LOW 60S. LOWS WILL BE IN THE 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1120 PM CST SAT DEC 6 2014 LIFR CONDITIONS CAN BE EXPECTED AT DDC AND HYS OVERNIGHT AS A MOIST SOUTHEASTERLY UPSLOPE FLOW CONTINUES AT 10 TO 15 KNOTS ACROSS WESTERN KANSAS. CEILINGS AND VISIBILITIES AT GCK ARE ALSO EXPECTED TO FALL BACK INTO THE LOW IFR/LIFR CATEGORY BY 08Z BASED ON THE LATEST HRRR, RAP AND NAM. AN UPPER LEVEL DISTURBANCE WILL CROSS THE CENTRAL PLAINS EARLY SUNDAY AND A SURFACE BOUNDARY, LOCATED NEAR THE COLORADO BORDER AT 05Z, WILL INTO WESTERN KANSAS. AS THE LOW LEVEL WINDS VEER TO THE SOUTHWEST THE VISIBILITIES AND CEILINGS WILL IMPROVE. CONFIDENCE IS NOT HIGH ON TIMING BUT GIVEN THE LATEST HRRR, RAP AND NAM WILL FAVOR IFR/MVFR AT GCK AND HYS BETWEEN 12 AND 15Z SUNDAY. FOR DDC WILL KEEP IFR CONDITIONS UNTIL LATE MORNING. VFR CONDITIONS ARE EXPECTED TO DEVELOP IN THE AFTERNOON AS SUBSIDENCE DEVELOPS BEHIND THE UPPER LEVEL TROUGH. && .PRELIMINARY POINT TEMPS/POPS... DDC 58 31 58 32 / 10 0 0 0 GCK 60 28 58 30 / 10 0 0 0 EHA 63 33 60 36 / 0 0 0 0 LBL 60 30 59 31 / 10 0 0 0 HYS 55 29 56 28 / 10 0 0 0 P28 57 33 58 33 / 10 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ030-031- 043>046-063>066-076>081-086>090. && $$ SHORT TERM...BURGERT LONG TERM...KRUSE AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1122 PM CST SAT DEC 6 2014 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1120 PM CST SAT DEC 6 2014 AT 00Z SUNDAY A 500MB TROUGH WAS LOCATED NEAR THE FOUR CORNERS REGION WITH A +90KNOT 250MB JET STREAK EXTENDING FROM THE BASED OF THIS UPPER LEVEL TROUGH INTO SOUTHWEST KANSAS. A SURFACE TROUGH OF LOW PRESSURE WAS LOCATED ALONG THE LEE OF THE ROCKIES AT 00Z SUNDAY AND A SURFACE HIGH EXTENDED FROM THE NORTHERN MISSISSIPPI VALLEY INTO NORTH TEXAS. A SOUTH TO SOUTHEASTERLY FLOW WAS PRESENT OVER WESTERN KANSAS WITH SURFACE DEWPOITNS IN THE MID TO UPPER 30S EVIDENT UPSTREAM IN OKLAHOMA. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 1217 PM CST SAT DEC 6 2014 SHORT RANGE MODELS INDICATE A WEAK UPPER LEVEL RIDGE TRANSITIONING EAST ACROSS THE CENTRAL PLAINS TONIGHT AS AN UPPER LEVEL SHORTWAVE MOVES EAST ACROSS THE DESERT SOUTHWEST INTO THE SOUTHERN ROCKIES. MEANWHILE, A BROAD AREA OF HIGH PRESSURE STRETCHING FROM THE UPPER MIDWEST DOWN INTO KANSAS WILL SHIFT EAST TONIGHT BRINGING ABOUT A SOUTHEASTERLY UPSLOPE FLOW TO WESTERN KANSAS. ALTHOUGH THE FLOW ALOFT IS EXPECTED TO WEAKEN THROUGH EARLY SUNDAY MORNING, ENOUGH LIFT COMBINED WITH INCREASING LOW/MID LEVEL MOISTURE MAY LEAD TO THE DEVELOPMENT OF FOG ACCOMPANIED BY LIGHT DRIZZLE/SPRINKLES LATE TONIGHT AS THE SHORTWAVE KICKS OUT OF THE SOUTHERN ROCKIES INTO THE WESTERN HIGH PLAINS. OTHERWISE, SIGNIFICANT PRECIP AMOUNTS ARE NOT EXPECTED. DRIER CONDITIONS ARE LIKELY ACROSS WESTERN KANSAS BY SUNDAY AFTERNOON AS THE SHORTWAVE MOVES FURTHER EAST. TEMPERATURES WILL BE ABOVE NORMAL TONIGHT AS A SOUTHEASTERLY UPSLOPE FLOW QUICKLY DEVELOPS DRAWING INCREASED MOISTURE UP INTO THE REGION. AS SURFACE DEWPOINTS CLIMB WELL INTO THE 20S(F) AND LOWER 30S(F), LOOK FOR LOWS ONLY DOWN INTO THE MID TO UPPER 30S(F) TONIGHT. A DEVELOPING LEE SIDE TROUGH EARLY SUNDAY MORNING WILL STRENGTHEN THROUGHOUT THE DAY TURNING THE LOW LEVEL FLOW MORE SOUTH TO SOUTHWESTERLY. THIS WILL ENHANCE WARM AIR ADVECTION INTO WESTERN KANSAS WITH H85 TEMPERATURES CLIMBING UP NEAR 8C TO 10C ACROSS CENTRAL AND SOUTHWEST KANSAS. EXPECT HIGHS WELL UP INTO THE 50S(F) ACROSS CENTRAL KANSAS TO THE LOWER AND MID 60S(F) IN EXTREME SOUTHWEST KANSAS WHERE SOME DOWNSLOPING MAY OCCUR. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 232 PM CST SAT DEC 6 2014 A MILD PERIOD IS FORECAST AHEAD OF THE NEXT UPPER LEVEL TROUGH AND STORM SYSTEM PUSHING INTO THE WESTERN U.S. BY NEXT WEEKEND. GFS ENSEMBLES ARE A BIT MORE AGGRESSIVE AND STRONGER THAN THE EUROPEAN MODEL WITH THIS NEXT SYSTEM THAT COULD BE A WEATHER MAKER INTO THE PLAINS AROUND THE 15TH AND 16TH OF DECEMBER. FOR MONDAY, LIGHT AND VARIABLE WINDS BECOME LIGHT SOUTHEASTERLY WITH HIGHS IN THE MID AND UPPER 50S. FOR TUESDAY, SOUTHERLY WINDS INCREASE AHEAD OF A LEE TROUGH, WITH HIGHS AGAIN FROM 55 TO 60. ON WEDNESDAY, AN UPPER LEVEL TROUGH BRINGS A COLD FRONT ACROSS WESTERN KANSAS IN THE MORNING INTO THE AFTERNOON. THERE COULD BE CONSIDERABLE LOW CLOUDS AND SOME FOG AHEAD OF THIS FRONT ON WEDNESDAY AS DEWPOINTS RISE INTO THE 40S. SOME LIGHT RAIN SHOWERS MAY BREAK OUT IN PARTS OF SOUTH CENTRAL KANSAS, MAINLY EAST OF DODGE CITY AHEAD OF THE COLD FRONT. HIGHS ON WEDNESDAY WILL CONTINUE TO BE IN THE 50S. OVERNIGHT LOWS MONDAY MORNING WILL RANGE FROM THE MID AND UPPER 20S ACROSS SOUTHWEST KANSAS TO THE LOW TO MID 30S NEAR MEDICINE LODGE. LOWS THEN WARM BACK INTO THE MID 30S INTO THURSDAY MORNING. FOR THE PERIOD OF THURSDAY INTO SATURDAY, UPPER LEVEL RIDGING AND WARMING MOVE INTO THE PLAINS AHEAD OF THE NEXT STORM SYSTEM PUSHING INTO THE WESTERN U.S. HIGHS WILL BE MILD AND IN THE MID 50S TO LOW 60S. LOWS WILL BE IN THE 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1120 PM CST SAT DEC 6 2014 LIFR CONDITIONS CAN BE EXPECTED AT DDC AND HYS OVERNIGHT AS A MOIST SOUTHEASTERLY UPSLOPE FLOW CONTINUES AT 10 TO 15 KNOTS ACROSS WESTERN KANSAS. CEILINGS AND VISIBILITIES AT GCK ARE ALSO EXPECTED TO FALL BACK INTO THE LOW IFR/LIFR CATEGORY BY 08Z BASED ON THE LATEST HRRR, RAP AND NAM. AN UPPER LEVEL DISTURBANCE WILL CROSS THE CENTRAL PLAINS EARLY SUNDAY AND A SURFACE BOUNDARY, LOCATED NEAR THE COLORADO BORDER AT 05Z, WILL INTO WESTERN KANSAS. AS THE LOW LEVEL WINDS VEER TO THE SOUTHWEST THE VISIBILITIES AND CEILINGS WILL IMPROVE. CONFIDENCE IS NOT HIGH ON TIMING BUT GIVEN THE LATEST HRRR, RAP AND NAM WILL FAVOR IFR/MVFR AT GCK AND HYS BETWEEN 12 AND 15Z SUNDAY. FOR DDC WILL KEEP IFR CONDITIONS UNTIL LATE MORNING. VFR CONDITIONS ARE EXPECTED TO DEVELOP IN THE AFTERNOON AS SUBSIDENCE DEVELOPS BEHIND THE UPPER LEVEL TROUGH. && .PRELIMINARY POINT TEMPS/POPS... DDC 36 58 30 58 / 10 20 0 0 GCK 34 60 27 58 / 10 10 0 0 EHA 37 63 33 60 / 10 0 0 0 LBL 37 60 29 59 / 10 10 0 0 HYS 30 55 29 56 / 10 20 0 0 P28 36 57 33 58 / 10 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR KSZ030-031-043>046- 063>066-076>081-086>090. && $$ SYNOPSIS...BURGERT SHORT TERM...JJOHNSON LONG TERM...KRUSE AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 PM MST SAT DEC 6 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 207 PM MST SAT DEC 6 2014 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW PROGRESSIVE TROUGH-RIDGE TROUGH PATTERN ACROSS US WITH RIDGE CURRENTLY EXTENDING FROM SOUTH CENTRAL CANADA ACROSS THE CENTRAL PLAINS. SW FLOW IS IN PLACE FROM THE FOUR CORNERS REGION AND INTO WESTERN KS WITH SHORTWAVE TROUGH MOVING OUT OF THE GREAT BASIN TOWARDS THE CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE OVER EASTERN COLORADO WITH SOUTHERLY FLOW ACROSS OUR CWA. AS SHORTWAVE TROUGH TRANSITIONS EASTWARD STATIONARY FRONT/BAROCLINIC ZONE WITH SHIFT NORTH AND EAST ALLOWING FOR SOUTHEAST MOISTURE RETURN INTO THE EASTERN HALF OF OUR CWA. MIDLEVEL MOISTURE/UPPER LEVEL FORCING COULD ALLOW FOR A BRIEF PERIOD OF LIGHT RAIN SHOWERS LATE TONIGHT...HOWEVER MODEL SOUNDINGS INDICATE A SIGNIFICANT DRY LAYER WOULD LIKELY PREVENT ANY ELEVATED PRECIPITATION FROM REACHING THE SURFACE. MAIN CONCERN WILL BE POTENTIAL FOR DENSE FOG DEVELOPMENT AND POTENTIAL FOR DRIZZLE ACROSS EASTERN CWA LATE TONIGHT THROUGH SUNDAY MORNING. NAM/RAP SHOW WEAK SURFACE CONVERGENCE IN PROXIMITY OF BAROCLINIC ZONE WHICH COULD PROVIDE ENOUGH LIFT WITHIN SHALLOW SATURATED LAYER TO ALLOW FOR DRIZZLE DEVELOPMENT. THIS COULD BE MORE OF A STRATUS/DRIZZLE EVENT...THOUGH CONSIDERING THE GOOD MOISTURE RETURN LOWER VISIBILITIES ARE CERTAINLY POSSIBLE. HIGH CLOUDS HAVE ALREADY BEEN HAVING AN IMPACT ON MIXING THIS AFTERNOON...AND WITH THICKENING/LOWERING CLOUDS THOUGH THE NIGHT (ALONG WITH TD VALUES INCREASING TO MID/UPPER 30S IN THE EAST)...RADIATIONAL COOLING WILL BE LIMITED. NOT ONLY COULD THIS LIMIT DENSE FOG DEVELOPMENT...BUT THIS MAKES FREEZING FOG/FREEZING DRIZZLE UNLIKELY AT THIS POINT. AT THIS POINT HOLDING OFF ON HIGHLIGHTS SEEMS THE BEST COURSE. WITH SHIFT BACK TO SW FLOW AS SHORTWAVE RIDGING BUILDS BACK INTO THE ROCKIES THERE SHOULD BE RAPID IMPROVEMENT IN CONDITIONS SUNDAY.CLEARING SKIES AND WAA THROUGH THE AFTERNOON SHOULD ALLOW HIGHS TO WARM TO AROUND 60F...THOUGH STRATUS MAY HOLD ON A LITTLE LONGER IN OUR EASTERN CWA LIMITING DAYTIME MIXING AND KEEPING HIGHS IN THE LOW TO MID 50S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 207 PM MST SAT DEC 6 2014 UPPER FLOW WILL BE NORTHWEST SUNDAY NIGHT AHEAD OF A RIDGE THAT WILL BUILD INTO THE ROCKIES AND PLAINS MONDAY AND TUESDAY. SURFACE HIGH PRESSURE WILL RESIDE OVER THE PLAINS THROUGH THIS TIME. DRY CONDITIONS WILL CONTINUE ACROSS THE FA THROUGH TUESDAY. SUBSIDENCE AND OR A LACK OF SIGNIFICANT FORCING ALONG WITH A LACK OF LAYER MEAN RH WILL PROVIDE SUPPORT FOR THE DRY CONDITIONS. POPS WILL BE NIL FROM SUNDAY NIGHT THROUGH TUESDAY. MIN TEMPERATURES SHOULD BE IN THE MID AND UPPER 20S SUNDAY AND MONDAY NIGHTS. MAX TEMPERATURES SHOULD RISE TO THE MID 50S MONDAY AND TUESDAY. IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)... THIS PART OF THE FORECAST IS ALSO DRY. A RIDGE WILL RESIDE OVER THE PLAINS THROUGH THURSDAY AND THEN SHIFT EAST FRIDAY AND SATURDAY WITH FLOW BECOMING SOUTHWEST. SURFACE HIGH PRESSURE WILL CONTINUE OVER THE CENTRAL PLAINS THROUGH WEDNESDAY FOLLOWED BY A TROUGH IN EASTERN COLORADO FROM THURSDAY THROUGH SATURDAY. MAX TEMPERATURES WILL GENERALLY BE IN THE MID TO UPPER 50S WEDNESDAY AND SATURDAY. MAX TEMPERATURES THURSDAY AND FRIDAY SHOULD WARM TO THE UPPER 50S WITH LOWER 60S IN THE WESTERN FA. MIN TEMPERATURES SHOULD COOL TO THE UPPER 20S AND LOWER 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1000 PM MST SAT DEC 6 2014 KGLD...SOUTH WIND AROUND 15KTS AT TAF ISSUANCE WILL VEER TO THE SOUTH AND DECREASE TO 10KTS BY 08Z UNDER A VFR OVERCAST SKY. STRATUS/BR MAY REACH THE TERMINAL FROM THE EAST/SOUTHEAST AROUND 08Z WITH IFR CIGS EXPECTED FROM 08Z-11Z WITH WINDS FROM THE SOUTH AROUND 10KTS. AROUND 12Z WINDS VEER TO THE SOUTHWEST 5-10KTS PUSHING THE STRATUS SLOWLY EAST ALLOWING FOR VFR CONDITIONS TO RETURN. WINDS THEN GO WEST UNDER 10KTS AROUND 15Z THEN SHIFT TO THE NORTHWEST 12G20KT POSSIBLY A BIT HIGHER IN THE 18Z-22Z TIMEFRAME UNDER JUST A FEW FAIR WEATHER CLOUDS. BY 23Z WINDS DISSIPATE TO 5KTS OR SO BY 23Z THEN BACK TO THE WEST AT SIMILAR SPEEDS AROUND 05Z. KMCK...SOUTHEAST WIND NEAR 10KT AT TAF ISSUANCE UNDER A VFR OVERCAST SKY. STRATUS/DRIZZLE/BR WITH IFR CONDITIONS AND POSSIBLY VLIFR CONDITIONS WITH VIS 1/2SM IN FG/DZ REACH THE TERMINAL FROM THE EAST AROUND 09Z AND CONTINUE THROUGH 17Z BEFORE WINDS VEER AROUND TO THE NORTHWEST NEAR 10KTS IN THE 17Z-20Z TIMEFRAME. THIS WILL SCOUR OUT THE STRATUS PRODUCING VFR CONDITIONS FROM 17Z THROUGH THE REST OF THE TAF PERIOD. IT SHOULD BE NOTED THAT IN THESE SCENARIOS THAT HIGH RESOLUTION MODELS OCCASIONALLY DONT PUSH THE STRATUS FAR ENOUGH WEST...BY AT LEAST ONE ROW OF COUNTIES. IF THIS VERIFIES STRATUS/BR (POSSIBLY FG WITH VLIFR CONDITIONS) MAY TAKE UP TO AN ADDITIONAL 3 HOURS TO MOVE OUT OF BOTH TERMINALS. WITH A THICK OVERCAST SKY HARD TO WATCH STRATUS PROGRESSION ON SATELLITE IMAGERY SO WILL HAVE TO WATCH METARS AND HOURLY MODEL UPDATES FROM THE RUC AND HRRR. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...FS AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1058 PM EST MON DEC 8 2014 .UPDATE... ISSUED AT 1058 PM EST MON DEC 8 2014 THE SPOTTY RADAR RETURNS AND ANY SPRINKLES ASSOCIATED WITH THEM HAVE LIFTED NORTH AND EAST OF THE AREA. BETTER RETURNS ARE OCCURRING UPSTREAM IN SOUTHERN INDIANA CLOSER TO THE APPROACHING COLD FRONT AND MID-LEVEL SHORT WAVE TROUGH. HAVE REMOVED THE MENTION OF SPRINKLES FROM THE FORECAST AT THIS POINT...AWAITING THE MORE SUBSTANTIAL SHOWERS FROM THE NORTHWEST. SOME OF THE SHELTERED VALLEYS HAVE TAKEN ADVANTAGE OF SOME CLOUD THINNING CURRENTLY MOVING ACROSS THE AREA...WITH THE BREATHITT COUNTY MESONET REPORTING 33 DEGREES AT THIS TIME. HAVE TRIED TO REFLECT SIMILAR SPOTS LIKELY DIPPING INTO THE LOW TO MID 30S HOWEVER...AS THE THICKER BLANKET OF LOWER CLOUDS MOVES IN FROM THE WEST...EXPECT THESE READINGS TO WARM UP. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 730 PM EST MON DEC 8 2014 THE SURFACE WARM FRONT ASSOCIATED WITH THE GREAT LAKES LOW PRESSURE SYSTEM IS CURRENTLY MOVING THROUGH EASTERN KENTUCKY. MOST OF THE RADAR RETURNS HAVE ONLY RESULTED IN SOME SPOTTY SPRINKLES THUS FAR AND THE LATEST HRRR ONLY SUPPORTS THIS UNTIL THE COLD FRONT ARRIVES LATER TONIGHT INTO EARLY TUESDAY MORNING. AS SUCH...HAVE DIALED BACK THE POPS A BIT FOR THE FIRST HALF OF THE NIGHT AND WILL ONLY CONTINUE TO MENTION A FEW SPRINKLES POSSIBLE. TEMPERATURES ARE CURRENTLY RUNNING IN THE LOW TO MID 40S FOR MOST LOCATIONS...HOWEVER A FEW SPOTS HAVE DIPPED INTO THE UPPER 30S. BLACK MOUNTAIN AND THE PIKE COUNTY MESONET HAVE BEEN HOVERING IN THE LOW TO MID 30S. THE LATEST MODEL GUIDANCE SUPPORTS TEMPERATURES AT THESE HIGHER ELEVATIONS TO REMAIN STEADY IF NOT FALL A BIT...ESPECIALLY TOWARDS DAWN WHEN THE PRECIP THREATENS. AS SUCH...WILL MENTION A CHANCE OF SNOW SHOWERS FOR ELEVATIONS ABOVE 2500 FEET. HAVE ADJUSTED THE TEMPERATURE CURVE FOR THESE LOCATIONS ALL THE WAY THROUGH THE DAY ON TUESDAY...AS READINGS WILL CONTINUE TO SLIDE THROUGH THE DAY. UPDATES WILL BE FORTHCOMING. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 359 PM EST MON DEC 8 2014 A DEEPENING TROUGH IS CURRENTLY SWEEPING ACROSS THE EASTERN CONUS...WITH A UPPER LEVEL SHORT WAVE EXPECTED TO MOVE SE ACROSS EASTERN KY BETWEEN 12 AND 18Z TUESDAY. AT THE SURFACE...AN AREA OF LOW PRESSURE IS CURRENTLY TRAVERSING LAKE SUPERIOR. A COLD FRONT AND WARM FRONT ARE EXTENDING SOUTHWARD FROM THIS LOW...WITH THE WARM FRONT HAVING JUST MOVED FROM SW TO NE ACROSS THE CWA...AND THE COLD FRONT EXPECTED TO TRAVERSE KY BETWEEN 6Z AND 12Z TONIGHT /MAY LINGER A BIT LONGER IN THE FAR SE/. WINDS REMAIN GENERALLY SRLY AS OF THIS AFTERNOON IN EASTERN KY...WITH TEMP READINGS IN THE MID 40S TO AROUND 50 AT PRESENT TIME. /THE CAVEAT TO THAT IS THE HIGHEST TERRAIN WHICH IS CURRENTLY ONLY IN THE MID AND UPPER 30S. MOISTURE AHEAD OF THE APPROACHING COLD FRONT IS CONTINUING TO ADVECT INTO THE REGION. THICK HIGH CLOUDS WILL CONTINUE TO LOWER THROUGHOUT THE EVENING AND OVERNIGHT AS MOISTURE WORKS ITS WAY DOWN TO THE SURFACE. AN AREA OF RADAR RETURNS IS CURRENTLY MOVING ACROSS CENTRAL KY AND TN...TREKKING EASTWARD TOWARDS THE JKL CWA. WHILE RETURNS HAVE LESSENED OVER THE LAST FEW HOURS...THE AMOUNT OF DRY AIR AT THE SURFACE THROUGHOUT THE MORNING/EARLY AFTERNOON HAS KEPT ANY OF THE RAIN FROM REACHING THE GROUND ACROSS KY. WENT AHEAD AND INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHERN CWA BY 0Z AS THIS AREA MOVES INTO OUR REGION...JUST IN CASE SOME LIGHT SHOWER IS ABLE TO BREAK THROUGH TO THE SURFACE. AS LOW LEVEL MOISTURE FINALLY BEGINS TO TAKE HOLD OVERNIGHT...EXPECT THE BEST CHANCES FOR RAIN TO BEGIN FILLING INTO EASTERN KY AFTER 6Z OVERNIGHT. THERE WILL BE AN ABUNDANT AMOUNT OF DRY AIR ALOFT...WITH ONLY A SHALLOW LAYER OF LOW/MID LEVEL MOISTURE TO WORK WITH DURING THIS EVENT. AS SUCH...ONLY WARRANTED CHANCE POPS AT THIS TIME...WITH SCATTERED SHOWERS EXPECTED OPPOSED TO A WIDESPREAD RAIN EVENT. THERE IS SOME QUESTION ABOUT THE PRECIP TYPE DURING THIS EVENT. UNFORTUNATELY IT IS NOT A CUT AND DRY SITUATION. A FEW DEGREES DIFFERENCE IN THE FIRST 1000 FEET COULD MAKE THE DIFFERENCE IN SNOW OR RAIN. AS OF NOW...MOISTURE IS CONFINED TO 8K FT AND BELOW...WITH NEARLY ALL OF THAT MOISTURE BELOW -10C HAVING NO INFLUENCE BY THE DENDRITIC GROWTH ZONE. THIS WOULD FAVOR LITTLE IN THE WAY OF SNOWFLAKE FORMATION. HOWEVER...TEMPS ARE BELOW FREEZING IN MUCH OF THE MOIST LAYER...EXCEPT RIGHT AT THE LOWEST 1000 FT. SO IF THERE IS ANY ICE/SNOW PELLETS...IT IS POSSIBLE THAT THEY MAY MELT ON THE WAY DOWN TO THE SURFACE. OR...AS TEMPS OVERNIGHT AND ON THE HIGHEST TERRAIN TOMORROW DIP DOWN SLIGHTLY...IT IS POSSIBLE THAT SOME SNOW/ICE PELLETS MAY MELT AND SOME MAY NOT...MAKING IT POSSIBLE FOR A MIXTURE OF SNOW AND ICE. TRIED TO STAY MORE OPTIMISTIC FOR THE NEXT 24 HOURS...WITH MAINLY RAIN CHANCES ACROSS THE REGION...EXCEPT IN PLACES ABOVE 1300 FEET THAT WILL EXPERIENCE SURFACE TEMPERATURES NEAR OR JUST ABOVE FREEZING. BY TOMORROW NIGHT...WHILE ALL OF THE ABOVE HOLDS TRUE...COLDER NE AIR BEHIND THE FRONTAL BOUNDARY WILL BEGIN PULLING INTO THE REGION. THIS MAY BE ENOUGH TO DROP TEMPS CLOSER TO THAT FREEZING MARK AND SLIGHTLY BELOW...ALLOWING MORE SNOW TO MIX IN WITH THE RAIN...OR IN A FEW PLACES...FALL AS SNOW ONLY. STILL...GIVEN THE WET AND SLIGHTLY WARMER SURFACE TEMPS...THE ONLY SNOW ACCUMULATIONS AT THIS POINT ARE IN THE HIGHEST TERRAIN AROUND BLACK MOUNTAIN TUESDAY NIGHT/WEDNESDAY MORNING. DRY AIR ALOFT WILL CONTINUE TO INCREASE THROUGHOUT THE OVERNIGHT HOURS...ESPECIALLY JUST BEHIND THE INITIAL COLD FRONTAL PASSAGE. THIS WILL WORK TO MAKE THE LAYER OF MOISTURE EVEN SHALLOWER...WHILE A IMPRESSIVELY STRONG INVERSION TAKES HOLD IN THE MID LEVELS. AS SUCH...IT IS STILL BORDERLINE AND SOMEWHAT UNCLEAR AS TO IF THE PRECIP THAT FALLS TUESDAY NIGHT WILL BE LIGHT RAIN/SNOW...OR MAYBE A WINTRY DRIZZLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 410 PM EST MON DEC 8 2014 AN UPPER LEVEL LOW WILL MEANDER OF THE MID ATLANTIC STATES INTO THE START OF THE WEEKEND. A SHORTWAVE TROUGH ROTATING AROUND THIS UPPER LOW WILL WORK ACROSS EASTERN KY ON WED. ONCE THIS SYSTEM DEPARTS...GRADUALLY RISING HEIGHTS ARE ANTICIPATED FROM THU INTO SAT ACROSS ACROSS THE LOWER OH VALLEY AND EASTERN KY AS AN UPPER LEVEL RIDGE BUILDS INTO MUCH OF THE EASTERN CONUS. THIS RIDGE WILL GRADUALLY DEPART LATE IN THE PERIOD...EARLY NEXT WEEK AND ALLOW AN UPPER LEVEL TROUGH TO MOVE INTO THE EASTERN CONUS. MODEL AGREEMENT INTO THE WEEKEND AND EARLY NEXT WEEK IS ABOVE AVERAGE WITH THE GENERAL PATTERN. THIS PATTERN WILL FAVOR BELOW NORMAL TEMPERATURES FROM WED INTO FRI AS HIGH PRESSURE BUILDS ACROSS THE AREA. AS FOR THE START OF THE PERIOD...MODELS HOLD ONTO SOME SHALLOW MOISTURE AND UPSLOPE FLOW...BUT LAPSE RATES ARE NOT ALL THAT IMPRESSIVE AND THE INVERSION HEIGHT IS NOT MUCH ABOVE THE -10C LEVEL AS WELL. MODELS ALSO HAVE SOME DIFFERENCES AND ICE MAY NOT BE PRESENT IN THE CLOUDS AT TIMES...ALTHOUGH MOISTURE SHOULD BE DEEPER FROM 12Z TO 18Z...AND POSSIBLY LONGER ON WED. THE GFS OVERALL SHOWS A BETTER POTENTIAL FOR ICE WITH MORE SATURATION IN THE -8C TO -10C LEVELS OR HIGHER. THE BULK OF WHAT SNOW THAT DOES FALL SHOULD NOT BE DENDRITES...BUT THE HIGHER ELEVATIONS AT 2000 FEET AND ABOVE SHOULD REMAIN AT OR BELOW FREEZING ON WED AND COULD RECEIVE SOME LIGHT ACCUMULATIONS. AS WITH MOST NW FLOW EVENTS...THERE IS SOME QUESTION AS TO WHEN THE MOISTURE AND CLOUDS WILL DEPART. AT THIS TIME...WE HAVE OPTED TO CONTINUE ON THE PESSIMISTIC SIDE WITH THE CLOUDS AND MOISTURE DEPARTURE AND HAVE CONTINUED TO HOLD ONTO SLIGHT CHANCE OF SNOW SHOWERS OR FLURRIES INTO WED EVENING. HOWEVER...AS THE SFC HIGH BEGINS TO SHIFT EAST OF THE AREA THIS WEEKEND...THE AIR MASS WILL MODERATE AND ABOVE NORMAL TEMPERATURES WILL ENSUE THROUGH THE END OF THE PERIOD. OTHER THAN THE START OF THE PERIOD...IT SHOULD BE DRY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 730 PM EST MON DEC 8 2014 VFR CONDITIONS WILL HOLD ON THROUGH 06Z...AND THEN A PASSING COLD FRONT WILL ALLOW FOR MVFR TO IFR CEILINGS TO FILL IN FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA BETWEEN 06 AND 12Z. LIGHT PRECIPITATION WILL ALSO WILL ACCOMPANYING THE FRONT...WITH MOST OF THIS ACTIVITY PEAKING IN THE 12 TO 18Z TIME FRAME. CEILINGS MAY THEN BUMP UP A BIT INTO THE AFTERNOON...WITH THE EXCEPTION OF THE FAR SOUTHEAST...WHERE MORE SUSTAINED RAIN/SNOW SHOWERS WILL CONTINUE TO BE SEEN THROUGH TUESDAY EVENING. SOUTHEAST TO SOUTH WINDS OF AROUND 5 KTS WILL VEER AROUND TO THE NORTHWEST AND INCREASE TO AROUND 10 KTS BY EARLY TUESDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JMW LONG TERM...JP AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
730 PM EST MON DEC 8 2014 .UPDATE... ISSUED AT 730 PM EST MON DEC 8 2014 THE SURFACE WARM FRONT ASSOCIATED WITH THE GREAT LAKES LOW PRESSURE SYSTEM IS CURRENTLY MOVING THROUGH EASTERN KENTUCKY. MOST OF THE RADAR RETURNS HAVE ONLY RESULTED IN SOME SPOTTY SPRINKLES THUS FAR AND THE LATEST HRRR ONLY SUPPORTS THIS UNTIL THE COLD FRONT ARRIVES LATER TONIGHT INTO EARLY TUESDAY MORNING. AS SUCH...HAVE DIALED BACK THE POPS A BIT FOR THE FIRST HALF OF THE NIGHT AND WILL ONLY CONTINUE TO MENTION A FEW SPRINKLES POSSIBLE. TEMPERATURES ARE CURRENTLY RUNNING IN THE LOW TO MID 40S FOR MOST LOCATIONS...HOWEVER A FEW SPOTS HAVE DIPPED INTO THE UPPER 30S. BLACK MOUNTAIN AND THE PIKE COUNTY MESONET HAVE BEEN HOVERING IN THE LOW TO MID 30S. THE LATEST MODEL GUIDANCE SUPPORTS TEMPERATURES AT THESE HIGHER ELEVATIONS TO REMAIN STEADY IF NOT FALL A BIT...ESPECIALLY TOWARDS DAWN WHEN THE PRECIP THREATENS. AS SUCH...WILL MENTION A CHANCE OF SNOW SHOWERS FOR ELEVATIONS ABOVE 2500 FEET. HAVE ADJUSTED THE TEMPERATURE CURVE FOR THESE LOCATIONS ALL THE WAY THROUGH THE DAY ON TUESDAY...AS READINGS WILL CONTINUE TO SLIDE THROUGH THE DAY. UPDATES WILL BE FORTHCOMING. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 359 PM EST MON DEC 8 2014 A DEEPENING TROUGH IS CURRENTLY SWEEPING ACROSS THE EASTERN CONUS...WITH A UPPER LEVEL SHORT WAVE EXPECTED TO MOVE SE ACROSS EASTERN KY BETWEEN 12 AND 18Z TUESDAY. AT THE SURFACE...AN AREA OF LOW PRESSURE IS CURRENTLY TRAVERSING LAKE SUPERIOR. A COLD FRONT AND WARM FRONT ARE EXTENDING SOUTHWARD FROM THIS LOW...WITH THE WARM FRONT HAVING JUST MOVED FROM SW TO NE ACROSS THE CWA...AND THE COLD FRONT EXPECTED TO TRAVERSE KY BETWEEN 6Z AND 12Z TONIGHT /MAY LINGER A BIT LONGER IN THE FAR SE/. WINDS REMAIN GENERALLY SRLY AS OF THIS AFTERNOON IN EASTERN KY...WITH TEMP READINGS IN THE MID 40S TO AROUND 50 AT PRESENT TIME. /THE CAVEAT TO THAT IS THE HIGHEST TERRAIN WHICH IS CURRENTLY ONLY IN THE MID AND UPPER 30S. MOISTURE AHEAD OF THE APPROACHING COLD FRONT IS CONTINUING TO ADVECT INTO THE REGION. THICK HIGH CLOUDS WILL CONTINUE TO LOWER THROUGHOUT THE EVENING AND OVERNIGHT AS MOISTURE WORKS ITS WAY DOWN TO THE SURFACE. AN AREA OF RADAR RETURNS IS CURRENTLY MOVING ACROSS CENTRAL KY AND TN...TREKKING EASTWARD TOWARDS THE JKL CWA. WHILE RETURNS HAVE LESSENED OVER THE LAST FEW HOURS...THE AMOUNT OF DRY AIR AT THE SURFACE THROUGHOUT THE MORNING/EARLY AFTERNOON HAS KEPT ANY OF THE RAIN FROM REACHING THE GROUND ACROSS KY. WENT AHEAD AND INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHERN CWA BY 0Z AS THIS AREA MOVES INTO OUR REGION...JUST IN CASE SOME LIGHT SHOWER IS ABLE TO BREAK THROUGH TO THE SURFACE. AS LOW LEVEL MOISTURE FINALLY BEGINS TO TAKE HOLD OVERNIGHT...EXPECT THE BEST CHANCES FOR RAIN TO BEGIN FILLING INTO EASTERN KY AFTER 6Z OVERNIGHT. THERE WILL BE AN ABUNDANT AMOUNT OF DRY AIR ALOFT...WITH ONLY A SHALLOW LAYER OF LOW/MID LEVEL MOISTURE TO WORK WITH DURING THIS EVENT. AS SUCH...ONLY WARRANTED CHANCE POPS AT THIS TIME...WITH SCATTERED SHOWERS EXPECTED OPPOSED TO A WIDESPREAD RAIN EVENT. THERE IS SOME QUESTION ABOUT THE PRECIP TYPE DURING THIS EVENT. UNFORTUNATELY IT IS NOT A CUT AND DRY SITUATION. A FEW DEGREES DIFFERENCE IN THE FIRST 1000 FEET COULD MAKE THE DIFFERENCE IN SNOW OR RAIN. AS OF NOW...MOISTURE IS CONFINED TO 8K FT AND BELOW...WITH NEARLY ALL OF THAT MOISTURE BELOW -10C HAVING NO INFLUENCE BY THE DENDRITIC GROWTH ZONE. THIS WOULD FAVOR LITTLE IN THE WAY OF SNOWFLAKE FORMATION. HOWEVER...TEMPS ARE BELOW FREEZING IN MUCH OF THE MOIST LAYER...EXCEPT RIGHT AT THE LOWEST 1000 FT. SO IF THERE IS ANY ICE/SNOW PELLETS...IT IS POSSIBLE THAT THEY MAY MELT ON THE WAY DOWN TO THE SURFACE. OR...AS TEMPS OVERNIGHT AND ON THE HIGHEST TERRAIN TOMORROW DIP DOWN SLIGHTLY...IT IS POSSIBLE THAT SOME SNOW/ICE PELLETS MAY MELT AND SOME MAY NOT...MAKING IT POSSIBLE FOR A MIXTURE OF SNOW AND ICE. TRIED TO STAY MORE OPTIMISTIC FOR THE NEXT 24 HOURS...WITH MAINLY RAIN CHANCES ACROSS THE REGION...EXCEPT IN PLACES ABOVE 1300 FEET THAT WILL EXPERIENCE SURFACE TEMPERATURES NEAR OR JUST ABOVE FREEZING. BY TOMORROW NIGHT...WHILE ALL OF THE ABOVE HOLDS TRUE...COLDER NE AIR BEHIND THE FRONTAL BOUNDARY WILL BEGIN PULLING INTO THE REGION. THIS MAY BE ENOUGH TO DROP TEMPS CLOSER TO THAT FREEZING MARK AND SLIGHTLY BELOW...ALLOWING MORE SNOW TO MIX IN WITH THE RAIN...OR IN A FEW PLACES...FALL AS SNOW ONLY. STILL...GIVEN THE WET AND SLIGHTLY WARMER SURFACE TEMPS...THE ONLY SNOW ACCUMULATIONS AT THIS POINT ARE IN THE HIGHEST TERRAIN AROUND BLACK MOUNTAIN TUESDAY NIGHT/WEDNESDAY MORNING. DRY AIR ALOFT WILL CONTINUE TO INCREASE THROUGHOUT THE OVERNIGHT HOURS...ESPECIALLY JUST BEHIND THE INITIAL COLD FRONTAL PASSAGE. THIS WILL WORK TO MAKE THE LAYER OF MOISTURE EVEN SHALLOWER...WHILE A IMPRESSIVELY STRONG INVERSION TAKES HOLD IN THE MID LEVELS. AS SUCH...IT IS STILL BORDERLINE AND SOMEWHAT UNCLEAR AS TO IF THE PRECIP THAT FALLS TUESDAY NIGHT WILL BE LIGHT RAIN/SNOW...OR MAYBE A WINTRY DRIZZLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 410 PM EST MON DEC 8 2014 AN UPPER LEVEL LOW WILL MEANDER OF THE MID ATLANTIC STATES INTO THE START OF THE WEEKEND. A SHORTWAVE TROUGH ROTATING AROUND THIS UPPER LOW WILL WORK ACROSS EASTERN KY ON WED. ONCE THIS SYSTEM DEPARTS...GRADUALLY RISING HEIGHTS ARE ANTICIPATED FROM THU INTO SAT ACROSS ACROSS THE LOWER OH VALLEY AND EASTERN KY AS AN UPPER LEVEL RIDGE BUILDS INTO MUCH OF THE EASTERN CONUS. THIS RIDGE WILL GRADUALLY DEPART LATE IN THE PERIOD...EARLY NEXT WEEK AND ALLOW AN UPPER LEVEL TROUGH TO MOVE INTO THE EASTERN CONUS. MODEL AGREEMENT INTO THE WEEKEND AND EARLY NEXT WEEK IS ABOVE AVERAGE WITH THE GENERAL PATTERN. THIS PATTERN WILL FAVOR BELOW NORMAL TEMPERATURES FROM WED INTO FRI AS HIGH PRESSURE BUILDS ACROSS THE AREA. AS FOR THE START OF THE PERIOD...MODELS HOLD ONTO SOME SHALLOW MOISTURE AND UPSLOPE FLOW...BUT LAPSE RATES ARE NOT ALL THAT IMPRESSIVE AND THE INVERSION HEIGHT IS NOT MUCH ABOVE THE -10C LEVEL AS WELL. MODELS ALSO HAVE SOME DIFFERENCES AND ICE MAY NOT BE PRESENT IN THE CLOUDS AT TIMES...ALTHOUGH MOISTURE SHOULD BE DEEPER FROM 12Z TO 18Z...AND POSSIBLY LONGER ON WED. THE GFS OVERALL SHOWS A BETTER POTENTIAL FOR ICE WITH MORE SATURATION IN THE -8C TO -10C LEVELS OR HIGHER. THE BULK OF WHAT SNOW THAT DOES FALL SHOULD NOT BE DENDRITES...BUT THE HIGHER ELEVATIONS AT 2000 FEET AND ABOVE SHOULD REMAIN AT OR BELOW FREEZING ON WED AND COULD RECEIVE SOME LIGHT ACCUMULATIONS. AS WITH MOST NW FLOW EVENTS...THERE IS SOME QUESTION AS TO WHEN THE MOISTURE AND CLOUDS WILL DEPART. AT THIS TIME...WE HAVE OPTED TO CONTINUE ON THE PESSIMISTIC SIDE WITH THE CLOUDS AND MOISTURE DEPARTURE AND HAVE CONTINUED TO HOLD ONTO SLIGHT CHANCE OF SNOW SHOWERS OR FLURRIES INTO WED EVENING. HOWEVER...AS THE SFC HIGH BEGINS TO SHIFT EAST OF THE AREA THIS WEEKEND...THE AIRMASS WILL MODERATE AND ABOVE NORMAL TEMPERATURES WILL ENSUE THROUGH THE END OF THE PERIOD. OTHER THAN THE START OF THE PERIOD...IT SHOULD BE DRY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 730 PM EST MON DEC 8 2014 VFR CONDITIONS WILL HOLD ON THROUGH 06Z...AND THEN A PASSING COLD FRONT WILL ALLOW FOR MVFR TO IFR CEILINGS TO FILL IN FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA BETWEEN 06 AND 12Z. LIGHT PRECIPITATION WILL ALSO WILL ACCOMPANYING THE FRONT...WITH MOST OF THIS ACTIVITY PEAKING IN THE 12 TO 18Z TIME FRAME. CEILINGS MAY THEN BUMP UP A BIT INTO THE AFTERNOON...WITH THE EXCEPTION OF THE FAR SOUTHEAST...WHERE MORE SUSTAINED RAIN/SNOW SHOWERS WILL CONTINUE TO BE SEEN THROUGH TUESDAY EVENING. SOUTHEAST TO SOUTH WINDS OF AROUND 5 KTS WILL VEER AROUND TO THE NORTHWEST AND INCREASE TO AROUND 10 KTS BY EARLY TUESDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JMW LONG TERM...JP AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1139 PM CST SAT DEC 6 2014 .AVIATION...AMPLE MOISTURE REMAINS DESPITE THE FRONTAL PASSAGE. WILL GO WITH PERSISTENCE AS UPSTREAM MVFR CIGS...AT OR BLO 2000FT AND THE RUC FIELDS SUPPORT LITTLE CHANGE INTO SUNDAY. LOW SUN ANGLES AND HIGH CLOUDS WILL MAKE FOR SLOW IMPROVEMENT BUT MVFR STRATOCU CIGS SHOULD FINALLY DISPERSE BY MID-DAY SUNDAY WITH A CIRRUS DECK ABOVE AND A CONTINUED NELY FLOW. SWEENEY && .PREV DISCUSSION... /ISSUED 936 PM CST SAT DEC 6 2014/ UPDATE...FORECAST LOOKS ON TRACK. NO UPDATE NEEDED. MARCOTTE PREV DISCUSSION... /ISSUED 536 PM CST SAT DEC 6 2014/ AVIATION...A CONCERN HAD BEEN THAT EXTENSIVE MOISTURE REMAINS IN THE WAKE OF THE WEAK COLD FRONT AND THAT CONDITIONS COULD DETERIORATE. THAT SAID, LOOKS LIKE A REINFORCING PUSH HAS SET UP ENOUGH COLD AND DRY ADVECTION TO PROVIDE OVERALL IMPROVEMENT. IN THE NEAR TERM, MVFR CIGS LOOK TO HANG IN UNTIL AFTER MIDNIGHT AT BOTH BPT AND LCH. MVFR CIGS AT AEX SHOULD BECOME VFR LATER THIS EVENING AS SKIES SCATTER OUT. CURRENT VFR CONDTIONS AT THE ACADIANA AIRPORTS SHOW IMPROVEMENT PER LATEST TIME-HEIGHT VERTICAL PROFILES. THAT SAID THERE IS AN EXTENSIVE MVFR CIG FIELD UPSTREAM TO THE NORTH AND INBOUND PVA AT THE BOUNDARY LAYER. THIS MOISTURE COULD BE JUST BELOW THE MODEL BOUNDARY. LOOKS LIKE PRUDENCE DICTATES PERSISTENCE ON THE MVFR CIGS FOR LFT AND ARA AT LEAST UNTIL THE PVA WANES AROUND AFTER MIDNIGHT. SWEENEY PREV DISCUSSION... /ISSUED 317 PM CST SAT DEC 6 2014/ DISCUSSION... THIS AFTERNOON...LITTLE RAIN FELL ACROSS OUR LAND AREA...BUT THERE IS A NARROW LINE OF SHOWERS IN THE COASTAL WATERS DUE TO A PRE- FRONTAL TROUGH...WORKING ITS WAY FURTHER OFFSHORE. ALSO...DENSE FOG HAS BEEN LINGERING OVER THE COASTAL WATERS...BUT IT IS CLEARING WEST TO EAST THIS AFTERNOON...AND SHOULD BE DISSIPATED BY THIS EVENING. NO RAIN IS FORECAST OVER THE NEXT 7 DAYS...AND TEMPERATURES ARE GENERALLY FORECAST TO BE NEAR NORMAL. SURFACE HIGH PRESSURE WILL BE THE DOMINANT WEATHER PATTERN ACROSS OUR REGION...STARTING TO OUR NORTH TONIGHT...AND SLOWLY WORKING ITS WAY TO OUR EAST BY THE END OF NEXT WEEK. 15 && .PRELIMINARY POINT TEMPS/POPS... KLCH 50 64 45 65 43 / 10 10 10 0 0 KBPT 51 65 45 65 44 / 10 10 10 0 0 KAEX 44 60 41 63 40 / 10 0 10 0 0 KLFT 49 63 44 65 43 / 10 10 10 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...SMALL CRAFT EXERCISE CAUTION UNTIL 6 AM CST SUNDAY FOR THE FOLLOWING ZONES: WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSLAKECHARLES WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
835 PM EST MON DEC 8 2014 .UPDATE... THE EARLIER UPDATE NUDGED THE FORECAST TOWARD A SLIGHTLY COLDER PRECIPITATION TYPE SOLUTION BY ADDING A GREATER COMPONENT OF SNOW OR A RAIN/SNOW MIX. THIS IS BASED ON RADAR INDICATIONS OF HIGHER PRECIPITATION RATES CAPABLE OF GREATER WET BULB COOLING...BUT THE OVERALL THERMAL PROFILE STILL SUPPORTS MOSTLY SNOW IN THE TRI CITIES REGION WITH JUST A BRIEF RAIN/SNOW MIX IN THE DETROIT AREA TO THE OHIO BORDER. PRECIPITATION RATES ARE BEING ENHANCED BY A FAVORABLE COMBINATION OF DYNAMIC FORCING FROM THE UPPER WAVE ACTING ON THE LOW TO MID LEVEL THETA-E RIDGE WHICH IS MATURING INTO A WELL DEFINED TROWAL. STRONG VERTICAL MOTION RESPONSE...AND THE POTENTIAL FOR IT TO CONTINUE...IS INDICATED BY STEEP MID LEVEL LAPSE RATES CENTERED AROUND 700 MB IN THE NEW 00Z DTX SOUNDING AS THE MOISTURE AXIS SLIDES THROUGH SE MICHIGAN DURING THE REST OF THE EVENING. THE MID LEVEL DRY SLOT ASSOCIATED WITH THE UPPER WAVE WILL BRING A QUICK END TO THE SNOW BY MIDNIGHT. THE PROGRESSION OF THE PATTERN WILL BE FAST ENOUGH TO HOLD THE LINE ON MINIMAL SNOW ACCUMULATION OVER THE AREA. THE TRI CITIES AND NORTHERN THUMB REGION DOES HAVE POTENTIAL FOR SNOW TO LINGER...AND MINOR UPWARD ADJUSTMENTS ON ACCUMULATION...AS MOISTURE REMAINS DEEPER WITHIN THE DEFORMATION AXIS ON THE NW FLANK OF THE WAVE AS IT TRACKS THROUGH THE SOUTHERN GREAT LAKES. THE TRANSITION FROM SNOW TO DRIZZLE...OR LACK THEREOF...WILL BE MONITORED DURING THE LATE EVENING. DRIZZLE AND FOG WILL MOVE OVER THE REST OF SE MICHIGAN AND PERSIST UNTIL NORTHWEST WIND INCREASES BEHIND THE COLD FRONT TOWARD SUNRISE. && .AVIATION...ISSUED 653 PM EST MON DEC 8 2014 //DISCUSSION... FORECAST EXPECTATIONS REMAIN ON TARGET AS THE MAIN AREA PRECIP MOVES THROUGH THE TERMINAL CORRIDOR DURING THE EVENING. SURFACE TEMPS NEAR 40 WILL HELP WITH A RAIN/SNOW MIX AT ONSET...BUT JUST BRIEFLY AT MBS BEFORE CHANGING TO SNOW...AND A SLIGHTLY LONGER MIX AT FNT BEFORE CHANGING OVER THERE AS WELL. EXPECT A MIX AS FAR SOUTH AS PTK BEFORE THE BAND MOVES TO THE EAST AROUND MIDNIGHT. THIS IS A SLIGHTLY COLDER PRECIP TYPE FORECAST BASED ON THE COOLING EFFECT OF HIGHER PRECIPITATION RATE INDICATED ON RADAR OVER SW LOWER AT PRESS TIME. EXPECT A QUICK DROP TO IFR/LIFR CEILING AT MOST LOCATIONS BY MID EVENING WITHIN THE PRECIPITATION AREA AND THEN LASTING THROUGH THE PASSAGE OF THE COLD FRONT/OCCLUDED FRONT. A SUBSTANTIAL COMPONENT OF FOG AND DRIZZLE IS INDICATED OVER WISCONSIN... ILLINOIS...AND INDIANA BY A COMBINATION OF SURFACE OBS AND RADAR COMPOSITE WITHIN AND SHORTLY TRAILING THE FRONT. THIS WILL REINFORCE LIFR CEILING UNTIL THE WIND INCREASES FROM THE NORTHWEST. COOLER AND DRIER AIR WILL THEN LEAD TO GRADUAL IMPROVEMENT TO MVFR WHERE CONDITIONS WILL SETTLE THROUGH TUESDAY AFTERNOON. FOR DTW... RAIN DURING THE EVENING COULD MIX BRIEFLY WITH WET SNOW...BUT NOT LONG ENOUGH FOR INCLUSION IN THE FORECAST AND WITH NO ACCUMULATION. //DTW THRESHOLD THREATS... * HIGH CONFIDENCE IN CEILING BELOW 5000 FEET TONIGHT. * HIGH CONFIDENCE IN RAIN AS PRECIPITATION TYPE. * MEDIUM CONFIDENCE IN VISIBILITY DROPPING BELOW 1/2 SM AND/OR CIGS BELOW 200 FT. && .PREV DISCUSSION...ISSUED 353 PM EST MON DEC 8 2014 SHORT TERM...THROUGH TONIGHT 19Z WATER VAPOR IMAGERY SHOWS WELL-DEFINED COMPACT MIDLEVEL WAVE OVER THE MN/IA BORDER SPINNING SEWD. UPPER LEVEL MOISTURE WAS PRESENT DOWNSTREAM OF THIS FEATURE OVER IN AND MI. MIDLEVEL FRONTOGENESIS WAS SUPPORTING A NORTH/SOUTH ORIENTED SWATH OF LIGHT TO MODERATE PRECIP OVER WESTERN MI AND NORTHERN IN...MOVING NEWD. THERE WAS A SHARP LOW-LEVEL MOISTURE GRADIENT IN PLACE AS EVIDENCED BY QUICKLY LOWERING CEILINGS AT THE ONSET OF PRECIPITATION. NWP IS IN GOOD AGREEMENT OF THE AREA OF FGEN AND ASSOCIATED PRECIP SHIELD TRANSLATING THROUGH THE LOCAL AREA BETWEEN AROUND 23-05Z /PERHAPS WEAKENING SOMEWHAT/ WITH ANY ONE AREA SEEING AROUND 3-4 HOURS OF PRECIP. QPF SHOULD BE GENERALLY LIGHT...AROUND .10-.15 INCHES. PRECIP TYPE IS A BIT OF A CHALLENGE. TEMPERATURES THIS AFTERNOON ARE IN THE UPPER 30S AND LOW 40S WITH DEWPOINTS STILL IN THE LOW/MID 20S OVER SE MI. RAP HAS A PRETTY GOOD HANDLE ON THIS WITH ASSOCIATED WETBULB TEMPS 32-35F. NOT EXPECTING TEMPS TO DROP A WHOLE LOT IN ADVANCE OF THE PRECIP WITH CLOUD COVER AND SOUTHERLY FLOW. DEWPOINTS SHOULD EDGE UPWARD INTO THE UPPER 20S. WETBULB EFFECTS ONCE THE PRECIP STARTS SHOULD DROP TEMPS INTO THE 33-37 DEGREE RANGE. WHILE MUCH OF THE REGION COULD EXPERIENCE A MIX OF RAIN AND SNOW /WITH SNOW MORE LIKELY IN THE AREAS OF EMBEDDED HEAVIER PRECIP/...HAVE GONE WITH PREDOMINANTLY RAIN FOR METRO DETROIT AND SOUTH...MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB...AND A MIX INBETWEEN. EXPECTING LOWS IN THE AREAS THAT EXPERIENCE SNOW TO MAINLY REMAIN AOA FREEZING WITH LOW SNOW RATIOS SO ACCUMULATIONS ARE NOT MUCH OF A CONCERN...WITH PERHAPS UP TO HALF AN INCH IN SPOTS ALONG AND NORTH OF I-69. ONCE THE UPPER MOISTURE STRIPS AWAY AFTER MIDNIGHT...THE SURFACE LOW WILL TRANSLATE OVER THE REGION CAUSING WINDS TO BECOME LIGHT. LOW- LEVEL MOISTURE WILL STILL BE AROUND. UPSTREAM OBS INDICATE WIDESPREAD LOW CLOUDS WITH AREAS OF FOG AND DRIZZLE AND EXPECT THAT WILL BE THE CASE OVER OUR AREA AS WELL. PATCHY AREAS OF FREEZING DRIZZLE ARE POSSIBLE WHERE TEMPS GET CLOSER TO FREEZING...ESPECIALLY OVER THE NORTHERN PARTS OF THE FORECAST AREA. LONG TERM...TUESDAY THROUGH SUNDAY THE EXTENDED FORECAST WILL START OFF WITH AN UPPER LEVEL TROUGH OVER THE GREAT LAKES DRIFTING OFF TO THE MID ATLANTIC COAST AS IT BECOMES A CLOSED MID LEVEL CIRCULATION. SE MI WILL BE UNDER THE UPPER LEVEL COLD POOL AND BROAD LIFT FROM THE TROUGH DURING THE MID WEEK PERIOD BEFORE LONGWAVE RIDGE BUILDING UP THROUGH THE CENTRAL CONUS TRIES TO FORCE ITS WAY INTO THE REGION. A BLOCKING PATTERN LOOKS TO SET UP BY THE END OF THE WEEK WITH THE INTERFACE BETWEEN THE RIDGE AND TROUGH IN THE VICINITY OF EASTERN MI. THIS PRESENTS ONE OF THE MAIN CHALLENGES IN THE LONG TERM AS THAT IS THE DIFFERENCE BETWEEN A MILD SUNNY WEEKEND OR A CLOUDY WEEKEND WITH THE POSSIBILITY OF LIGHT SNOWFALL. WE START OFF TUESDAY WITH THE TROUGH AXIS OVER HEAD WHICH WILL PRODUCE OVERCAST SKIES AND WINDS VEERING FROM SOUTHERLY TO NORTHERLY THROUGH THE AFTERNOON. ADDITIONALLY...THE BROAD CYCLONIC FLOW AND LIFT WITH A SATURATED COLUMN UP TO 8KFT WILL PRODUCE SOME LINGERING SHOWERS THROUGH THE DAY AS THE FORCING PULLS OFF TO THE EAST. ONE QUESTION REMAINS TO BE WHAT WILL THE PTYPE BE ON TUESDAY? THE TREND WILL BE FOR THE COLUMN TO COOL AS THE -26C 500MB COLD POOL SLIDE OVER THE AREA. 925MB TEMPS WILL BE CLOSE TO ZERO WITH 850MB TEMPS A COUPLE DEGREES IN THE NEGATIVE. BUT THE SATURATION ONLY CLIMBS TO AROUND 750MB OR SO WHICH MAY NOT QUITE BE ENOUGH FOR ALL ICE CRYSTALS WITH TEMPS NEARING -9C. SO KEPT THE MENTION OF DRIZZLE THROUGH THE FIRST HALF OF THE DAY POSSIBLY SWITCHING OVER TO ALL SNOW CLOSER TO 00Z WEDNESDAY. TEMPERATURES ABOVE FREEZING UP TOWARD 950MB...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE CWA SHOULD PREVENT FREEZING DRIZZLE AS SFC TEMPS REACH INTO THE UPPER 30S. THE NATURE OF THE PRECIP FORCING CHANGES OVERNIGHT TUESDAY INTO WEDNESDAY AS THE DEEPER MOISTURE GETS PULLED EAST LEAVING A VERY SHALLOW LAYER OF MOISTURE WITH NORTHERLY FLOW. THIS COLDER NORTHERLY FLOW OFF LAKE HURON WILL LIKELY PRODUCE SOME LAKE EFFECT SNOW OVER THE THUMB BUT MODELS DO NO INDICATE ANY STRONG CONVERGENT REGIONS OVER THE LAKE AND DELTA T FROM THE SFC TO 850MB IS RATHER WEAK AROUND 10C. WILL CONTINUE THE HIGHER POP...LOWER QPF FORECAST FOR THE THUMB UNTIL WE SEE MORE DEFINITIVE SIGNATURES TO LOWER THE POPS OR START THINKING IN TERMS OF POSSIBLE ACCUMULATIONS. TEMPERATURES OVER LAND WEDNESDAY WILL HOLD AROUND THE FREEZING MARK AS THE BACKSIDE OF THE COLD POOL ALOFT LINGERS OVER THE EASTERN GREAT LAKES. HIGH PRESSURE...AND DRY WEATHER...LOOKS TO REMAIN IN PLACE THROUGH MUCH OF THE EXTENDED PERIOD. SOME RECENT MODEL RUNS INDICATE A CHANCE OF SOME SNOW SHOWERS TRYING TO CREEP IN ON THURSDAY AS A LOW PRESSURE SYSTEM DEVELOPS TO OUR EAST. CONFIDENCE IN THIS FEATURE AT THIS TIME IS LOW AND HAVE ONLY INCLUDED A SLIGHT CHANCE OF SOME SNOW FOR THE EXTREME EASTERN PORTION OF THE CWA /ST CLAIR SANILAC AND EASTERN HURON COUNTIES/. OTHERWISE DRY CONDITIONS PREVAIL THROUGH THE WEEKEND WITH THE NEXT DISTURBANCE ARRIVING LATE SUNDAY. CURRENT MODEL GUIDANCE SHOWS TEMPERATURES WILL BE WARM ENOUGH FOR PRECIPITATION WITH THIS SYSTEM TO BE ALL RAIN...HOWEVER...WOULD NOT BE SURPRISED IF SOME SNOW MIXES IN ON SUNDAY NIGHT AS TEMPERATURES BEGIN TO DROP. FOR NOW HAVE JUST LEFT THE PRECIPITATION AS ALL RAIN BUT SNOW MAY HAVE TO BE ADDED LATER AS WE GET A BETTER SAMPLING OF HOW THIS SYSTEM WILL PLAY OUT. MARINE... AN UPPER LEVEL TROUGH OF LOW PRESSURE AND ASSOCIATED WEAK SURFACE REFLECTION WILL BRING UNSETTLED WEATHER TO THE GREAT LAKES FOR THE NEXT COUPLE DAYS. SOUTHERLY FLOW AHEAD OF THE TROUGH IS BEGINNING TO SETTLE ALLOWING US TO CANCEL THE SMALL CRAFT ADVISORY OVER SAGINAW BAY A FEW HOURS EARLY BUT FLOW OVER LAKE HURON WILL WARRANT THE CONTINUATION OF THE NEARSHORE SMALL CRAFTS THROUGH THE EVENING WITH GUSTS AROUND 25 KNOTS AND ELEVATED WAVE HEIGHTS. THE TROUGH AXIS WILL TRACK ACROSS THE AREA TUESDAY VEERING WINDS AROUND TO THE NORTH. COLD AIR ADVECTION BEHIND A PASSING COLD FRONT OVER THE SLIGHTLY WARMER WATERS...WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE STALLING UPPER LEVEL TROUGH AND THE RIDGE TRYING TO BUILD IN FROM THE WEST WILL HELP EXCITE THE WIND FIELD ONCE AGAIN. A MARGINAL GALE WATCH CONTINUES FOR THE SOUTHERN LAKE HURON BASIN AS WINDS LOOK TO GUST NEAR 35 KNOTS WITH THIS SETUP. THE UPPER LEVEL FEATURE MAY TRY TO HEAD BACK WEST TOWARD THE AREA LATER IN THE WEEK WHICH WOULD KEEP SOME SEMBLANCE OF THE INCREASED NORTHERLY FLOW THROUGH MID WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR LHZ441>443-462>464. SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ441>443. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......BT AVIATION.....BT SHORT TERM...DT LONG TERM....DRK/RK MARINE.......DRK YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
716 PM EST MON DEC 8 2014 .UPDATE... ISSUED AT 713 PM EST MON DEC 8 2014 LOW PRESSURE SLIDING OVER CNTRL UPR MICHIGAN AS OF 23Z. COLD AIR IN WAKE OF THE LOW SLOW TO ARRIVE. DEEP MOISTURE TIED INTO THE LOW HAS FADED QUICKLY AND LEFTOVER MOISTURE IS SHALLOW IN DEPTH AND TEMPS WITHIN THE MOIST LAYER ARE ONLY AS COOL AS -4C TO -6C OVER WESTERN LK SUPERIOR AND WESTERN CWA. VSBY AT IWD AND CMX HAS BEEN BLO 5SM SINCE SUNSET. REPORTS FM SOCIAL MEDIA INDICATE DRIZZLE OCCURRING OVER KEWEENAW AND LOWER ELEVATIONS OF ONTONAGON COUNTY. SOME SNOW FLURRIES ARE FALLING OVER HIGHER TERRAIN IN ONTONAGON COUNTY. ADDED PATCHY DZ/FZDZ TO GRIDS UNTIL AROUND 06Z FOR WEST/NORTHWEST AND INTO NCNTRL. RAP/NAM/GFS SOUNDINGS INDICATE AFTER 06Z IT BECOMES COLD ENOUGH FOR MIXED PRECIP TO CHANGE TO MAINLY SNOW. ADDED FOG TO MUCH OF EAST HALF OF CWA THROUGH THE EVENING WITH SOUTHERLY FLOW OVER LK MICHIGAN PUSHING DWPNTS IN LOW 30S OVER THE WET SNOW PACK FM THE SNOW THAT OCCURRED EARLIER TODAY. ALREADY SEEING VSBY BLO 2SM OVER MOST OF THE EAST PART OF THE CWA...INCLUDING VSBY DOWN TO 1/4SM IN THE LAST HOUR AT MNM. ONCE WINDS IN BLYR SHIFT TO NW LATER THIS EVENING...FOG SHOULD BEGIN TO LIFT AS MOISTENING FLOW OFF LK MICHIGAN WILL BE DIMINISHED. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 304 PM EST MON DEC 8 2014 LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS THE SHOW SHORTWAVE TROF MOVING ACROSS THE UPPER GREAT LAKES THIS AFTERNOON. MODELS INDICATE BEST ISENTROPIC ASCENT...MOISTURE TRANSPORT AND DEEP LAYER Q-VECT CONVERGENCE HAS SHIFTED EAST WITH MAIN SNOW BAND AHEAD OF THE SFC-8H TROF OVER CENTRAL UPPER MI. IT/S POSSIBLE THERE MAY BE SOME PATCHY -FZDZ LATE THIS AFTERNOON BEHIND THE SNOW BAND WITH MID-LVL DRYING AND LOW-LVL MOISTURE TOO SHALLOW TO REACH THE -10C ISOTHERM...BUT NOT SURE IF THE FZDZ WILL BE SIGNIFICANT ENOUGH TO INCLUDE IN FCST GRIDS THIS EVENING. MODELS INDICATE THAT N TO NW WINDS WILL STRENGTHEN TONIGHT BEHIND DEPARTING LOW PRES TONIGHT. COOLING LOW-LEVEL AIR MASS MAY SUPPORT SOME LAKE ENHANCED SNOW FOR A BRIEF TIME THIS EVENING. HOWEVER...SNOWFALL IS EXPECTED TO BE LIGHT FOR THE FOLLOWING REASONS...850MB TEMPS (AROUND -6C) ARE MARGINAL FOR ENHANCEMENT WHILE DEEPER MOISTURE IS AROUND...LOW-LEVEL FLOW IS NOT STRONGLY CYCLONIC...AND DGZ IS ABOVE THE UPWARD MOTION AND THE DEEPER MOISTURE. UPSLOPE/OROGRAPHIC MOTION MAY BE THE DRIVING COMPONENT AIDING SNOWFALL...AND WHERE THAT IS MAXIMIZED...EXPECT GENERALLY 1-2 INCHES OF SNOW TONIGHT OVER HIGHER TERRAIN NEAR LAKE SUPERIOR. INCREASED SUBSIDENCE AND LOWERING OF INVERSION HGTS AHEAD OF THE BUILDING MID-LVL RDG UPSTREAM MAY ALSO CONTRIBUTE TO A BRIEF PD OF UPSLOPE FZDZ LATE TONIGHT OVER THE NRN TIER COUNTIES IN NRLY FLOW LATE TONIGHT...BUT NAM SNDGS SHOW THE SHALLOW MOIST LAYER COOLING TO -10C BY SUNRISE WHICH SHOULD AGAIN SUPPORT MAINLY LIGHT SNOW/FLURRIES. SINCE FZDZ THREAT IS UNCERTAIN AND LOOKS TO BE BRIEF IF IT DOES OCCUR WL LEAVE IT OUT OF GRIDS FOR NOW. LOOK FOR MIN TEMPS RANGING FROM THE LOWER 20S INTERIOR WEST TO UPPER 20S EAST HALF. 1034 MB SFC RIDGE BUILDING IN FROM THE WEST SHOULD WEAKEN THE PRES GRADIENT AND THUS ALLOW NRLY WINDS TO DIMINISH ACROSS THE AREA BY AFTERNOON. CONTINUED LOWERING OF INVERSION BASES BLO 3KFT WILL QUICKLY DIMINISH ANY REMAINING LIGHT UPSLOPE SHSN TO FLURRIES BY LATE MORNING. LOOK FOR HIGHS RANGING FROM THE LOWER TO MID 20S WEST TO LOWER 30S EAST HALF. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 422 PM EST MON DEC 8 2014 DRY WEATHER WILL BE THE RULE THROUGH SATURDAY MORNING...WITH HIGH PRESSURE FROM THE SFC-500MB. BOTH THE GFS AND ECMWF BRING SOME MOISTURE BACK TO THE AREA DURING THE DAY SATURDAY...AS THE SFC RIDGE EXITS E TO THE LOWER GREAT LAKES AND THE AXIS OF THE 500MB RIDGE MOVES ACROSS THE UPPER GREAT LAKES. LOOK FOR SLOWLY INCREASING W-SW WINDS DURING THE DAY SATURDAY WITH 850MB TEMPS WARMING TO 9 TO 12C. THIS WILL BE QUITE A CHANGE FROM THE CURRENT VALUES WHICH ARE HOVERING AROUND -4C. THE MAIN CONCERN FOR THIS PERIOD WILL COME IN SATURDAY THROUGH MONDAY. AS MOISTURE INCREASES...LIGHT WAA WILL LIKELY OVERSPREAD THE CWA. KEPT THE MENTION OF PATCHY FOG AS WELL FOR THIS WILL BE IN ADVANCE OF THE ELONGATED SFC LOW OVER THE N AND CENTRAL PLAINS AT 00Z SUNDAY WITH THE HIGH DEW POINTS OVER THE MELTING SNOWPACK. THE 12Z RUNS OF THE ECMWF AND GFS BOTH HAVE THE LOW OVER MN AT 12Z SUNDAY...THEN SHIFTING ACROSS UPPER MI/LAKE SUPERIOR/CENTRAL ONTARIO SUNDAY NIGHT. WITH LOW TEMPERATURES FALLING INTO THE MID 20S TO LOW 30S...THE POTENTIAL EXISTS FOR FREEZING RAIN OR FREEZING DRIZZLE. WILL CONTINUE TO FOCUS ON THIS PERIOD...AND ADJUST AS NEEDED AS THE TIME NEARS. LOOK FOR THE COLD AIR TO SURGE IN BEHIND THE EXITING LOW/COLD FRONT SUNDAY NIGHT INTO MONDAY...WITH PRECIP TURNING ALL BACK TO SNOW BY MONDAY EVENING AT THE LATEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1252 PM EST MON DEC 8 2014 LOW LEVEL MOISTURE ACCOMPANYING A LOW PRES SYSTEM MOVING THROUGH THE AREA WILL RESULT IN IFR CIGS AND SCT -SHSN THIS AFTERNOON. IFR CONDITIONS SHOULD PERSIST TONIGHT WITH SNOW PICKING UP FOR A TIME UNDER STRENGTHENING UPSLOPE NNW-N WINDS. THERE MAY BE SOME IMPROVEMENT AT KCMX LATE TONIGHT AS UPSLOPING DIMINISHES AND SOME MINOR DIURNAL IMPROVEMENT AT KIWD AND KSAW TUE MORNING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 304 PM EST MON DEC 8 2014 BEHIND THE LOW...N TO NW WINDS RAMP UP TONIGHT...AIDED BY PRES RISES APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS POTENTIAL FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL TO SCNTRL LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH PRES RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE UPPER LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED... AND THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...VOSS LONG TERM...KF AVIATION...JLA MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
653 PM EST MON DEC 8 2014 .AVIATION... //DISCUSSION... FORECAST EXPECTATIONS REMAIN ON TARGET AS THE MAIN AREA PRECIP MOVES THROUGH THE TERMINAL CORRIDOR DURING THE EVENING. SURFACE TEMPS NEAR 40 WILL HELP WITH A RAIN/SNOW MIX AT ONSET...BUT JUST BRIEFLY AT MBS BEFORE CHANGING TO SNOW...AND A SLIGHTLY LONGER MIX AT FNT BEFORE CHANGING OVER THERE AS WELL. EXPECT A MIX AS FAR SOUTH AS PTK BEFORE THE BAND MOVES TO THE EAST AROUND MIDNIGHT. THIS IS A SLIGHTLY COLDER PRECIP TYPE FORECAST BASED ON THE COOLING EFFECT OF HIGHER PRECIPITATION RATE INDICATED ON RADAR OVER SW LOWER AT PRESS TIME. EXPECT A QUICK DROP TO IFR/LIFR CEILING AT MOST LOCATIONS BY MID EVENING WITHIN THE PRECIPITATION AREA AND THEN LASTING THROUGH THE PASSAGE OF THE COLD FRONT/OCCLUDED FRONT. A SUBSTANTIAL COMPONENT OF FOG AND DRIZZLE IS INDICATED OVER WISCONSIN... ILLINOIS...AND INDIANA BY A COMBINATION OF SURFACE OBS AND RADAR COMPOSITE WITHIN AND SHORTLY TRAILING THE FRONT. THIS WILL REINFORCE LIFR CEILING UNTIL THE WIND INCREASES FROM THE NORTHWEST. COOLER AND DRIER AIR WILL THEN LEAD TO GRADUAL IMPROVEMENT TO MVFR WHERE CONDITIONS WILL SETTLE THROUGH TUESDAY AFTERNOON. FOR DTW... RAIN DURING THE EVENING COULD MIX BRIEFLY WITH WET SNOW...BUT NOT LONG ENOUGH FOR INCLUSION IN THE FORECAST AND WITH NO ACCUMULATION. //DTW THRESHOLD THREATS... * HIGH CONFIDENCE IN CEILING BELOW 5000 FEET TONIGHT. * HIGH CONFIDENCE IN RAIN AS PRECIPITATION TYPE. * MEDIUM CONFIDENCE IN VISIBILITY DROPPING BELOW 1/2 SM AND/OR CIGS BELOW 200 FT. && .PREV DISCUSSION...ISSUED 353 PM EST MON DEC 8 2014 SHORT TERM...THROUGH TONIGHT 19Z WATER VAPOR IMAGERY SHOWS WELL-DEFINED COMPACT MIDLEVEL WAVE OVER THE MN/IA BORDER SPINNING SEWD. UPPER LEVEL MOISTURE WAS PRESENT DOWNSTREAM OF THIS FEATURE OVER IN AND MI. MIDLEVEL FRONTOGENESIS WAS SUPPORTING A NORTH/SOUTH ORIENTED SWATH OF LIGHT TO MODERATE PRECIP OVER WESTERN MI AND NORTHERN IN...MOVING NEWD. THERE WAS A SHARP LOW-LEVEL MOISTURE GRADIENT IN PLACE AS EVIDENCED BY QUICKLY LOWERING CEILINGS AT THE ONSET OF PRECIPITATION. NWP IS IN GOOD AGREEMENT OF THE AREA OF FGEN AND ASSOCIATED PRECIP SHIELD TRANSLATING THROUGH THE LOCAL AREA BETWEEN AROUND 23-05Z /PERHAPS WEAKENING SOMEWHAT/ WITH ANY ONE AREA SEEING AROUND 3-4 HOURS OF PRECIP. QPF SHOULD BE GENERALLY LIGHT...AROUND .10-.15 INCHES. PRECIP TYPE IS A BIT OF A CHALLENGE. TEMPERATURES THIS AFTERNOON ARE IN THE UPPER 30S AND LOW 40S WITH DEWPOINTS STILL IN THE LOW/MID 20S OVER SE MI. RAP HAS A PRETTY GOOD HANDLE ON THIS WITH ASSOCIATED WETBULB TEMPS 32-35F. NOT EXPECTING TEMPS TO DROP A WHOLE LOT IN ADVANCE OF THE PRECIP WITH CLOUD COVER AND SOUTHERLY FLOW. DEWPOINTS SHOULD EDGE UPWARD INTO THE UPPER 20S. WETBULB EFFECTS ONCE THE PRECIP STARTS SHOULD DROP TEMPS INTO THE 33-37 DEGREE RANGE. WHILE MUCH OF THE REGION COULD EXPERIENCE A MIX OF RAIN AND SNOW /WITH SNOW MORE LIKELY IN THE AREAS OF EMBEDDED HEAVIER PRECIP/...HAVE GONE WITH PREDOMINANTLY RAIN FOR METRO DETROIT AND SOUTH...MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB...AND A MIX INBETWEEN. EXPECTING LOWS IN THE AREAS THAT EXPERIENCE SNOW TO MAINLY REMAIN AOA FREEZING WITH LOW SNOW RATIOS SO ACCUMULATIONS ARE NOT MUCH OF A CONCERN...WITH PERHAPS UP TO HALF AN INCH IN SPOTS ALONG AND NORTH OF I-69. ONCE THE UPPER MOISTURE STRIPS AWAY AFTER MIDNIGHT...THE SURFACE LOW WILL TRANSLATE OVER THE REGION CAUSING WINDS TO BECOME LIGHT. LOW- LEVEL MOISTURE WILL STILL BE AROUND. UPSTREAM OBS INDICATE WIDESPREAD LOW CLOUDS WITH AREAS OF FOG AND DRIZZLE AND EXPECT THAT WILL BE THE CASE OVER OUR AREA AS WELL. PATCHY AREAS OF FREEZING DRIZZLE ARE POSSIBLE WHERE TEMPS GET CLOSER TO FREEZING...ESPECIALLY OVER THE NORTHERN PARTS OF THE FORECAST AREA. LONG TERM...TUESDAY THROUGH SUNDAY THE EXTENDED FORECAST WILL START OFF WITH AN UPPER LEVEL TROUGH OVER THE GREAT LAKES DRIFTING OFF TO THE MID ATLANTIC COAST AS IT BECOMES A CLOSED MID LEVEL CIRCULATION. SE MI WILL BE UNDER THE UPPER LEVEL COLD POOL AND BROAD LIFT FROM THE TROUGH DURING THE MID WEEK PERIOD BEFORE LONGWAVE RIDGE BUILDING UP THROUGH THE CENTRAL CONUS TRIES TO FORCE ITS WAY INTO THE REGION. A BLOCKING PATTERN LOOKS TO SET UP BY THE END OF THE WEEK WITH THE INTERFACE BETWEEN THE RIDGE AND TROUGH IN THE VICINITY OF EASTERN MI. THIS PRESENTS ONE OF THE MAIN CHALLENGES IN THE LONG TERM AS THAT IS THE DIFFERENCE BETWEEN A MILD SUNNY WEEKEND OR A CLOUDY WEEKEND WITH THE POSSIBILITY OF LIGHT SNOWFALL. WE START OFF TUESDAY WITH THE TROUGH AXIS OVER HEAD WHICH WILL PRODUCE OVERCAST SKIES AND WINDS VEERING FROM SOUTHERLY TO NORTHERLY THROUGH THE AFTERNOON. ADDITIONALLY...THE BROAD CYCLONIC FLOW AND LIFT WITH A SATURATED COLUMN UP TO 8KFT WILL PRODUCE SOME LINGERING SHOWERS THROUGH THE DAY AS THE FORCING PULLS OFF TO THE EAST. ONE QUESTION REMAINS TO BE WHAT WILL THE PTYPE BE ON TUESDAY? THE TREND WILL BE FOR THE COLUMN TO COOL AS THE -26C 500MB COLD POOL SLIDE OVER THE AREA. 925MB TEMPS WILL BE CLOSE TO ZERO WITH 850MB TEMPS A COUPLE DEGREES IN THE NEGATIVE. BUT THE SATURATION ONLY CLIMBS TO AROUND 750MB OR SO WHICH MAY NOT QUITE BE ENOUGH FOR ALL ICE CRYSTALS WITH TEMPS NEARING -9C. SO KEPT THE MENTION OF DRIZZLE THROUGH THE FIRST HALF OF THE DAY POSSIBLY SWITCHING OVER TO ALL SNOW CLOSER TO 00Z WEDNESDAY. TEMPERATURES ABOVE FREEZING UP TOWARD 950MB...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE CWA SHOULD PREVENT FREEZING DRIZZLE AS SFC TEMPS REACH INTO THE UPPER 30S. THE NATURE OF THE PRECIP FORCING CHANGES OVERNIGHT TUESDAY INTO WEDNESDAY AS THE DEEPER MOISTURE GETS PULLED EAST LEAVING A VERY SHALLOW LAYER OF MOISTURE WITH NORTHERLY FLOW. THIS COLDER NORTHERLY FLOW OFF LAKE HURON WILL LIKELY PRODUCE SOME LAKE EFFECT SNOW OVER THE THUMB BUT MODELS DO NO INDICATE ANY STRONG CONVERGENT REGIONS OVER THE LAKE AND DELTA T FROM THE SFC TO 850MB IS RATHER WEAK AROUND 10C. WILL CONTINUE THE HIGHER POP...LOWER QPF FORECAST FOR THE THUMB UNTIL WE SEE MORE DEFINITIVE SIGNATURES TO LOWER THE POPS OR START THINKING IN TERMS OF POSSIBLE ACCUMULATIONS. TEMPERATURES OVER LAND WEDNESDAY WILL HOLD AROUND THE FREEZING MARK AS THE BACKSIDE OF THE COLD POOL ALOFT LINGERS OVER THE EASTERN GREAT LAKES. HIGH PRESSURE...AND DRY WEATHER...LOOKS TO REMAIN IN PLACE THROUGH MUCH OF THE EXTENDED PERIOD. SOME RECENT MODEL RUNS INDICATE A CHANCE OF SOME SNOW SHOWERS TRYING TO CREEP IN ON THURSDAY AS A LOW PRESSURE SYSTEM DEVELOPS TO OUR EAST. CONFIDENCE IN THIS FEATURE AT THIS TIME IS LOW AND HAVE ONLY INCLUDED A SLIGHT CHANCE OF SOME SNOW FOR THE EXTREME EASTERN PORTION OF THE CWA /ST CLAIR SANILAC AND EASTERN HURON COUNTIES/. OTHERWISE DRY CONDITIONS PREVAIL THROUGH THE WEEKEND WITH THE NEXT DISTURBANCE ARRIVING LATE SUNDAY. CURRENT MODEL GUIDANCE SHOWS TEMPERATURES WILL BE WARM ENOUGH FOR PRECIPITATION WITH THIS SYSTEM TO BE ALL RAIN...HOWEVER...WOULD NOT BE SURPRISED IF SOME SNOW MIXES IN ON SUNDAY NIGHT AS TEMPERATURES BEGIN TO DROP. FOR NOW HAVE JUST LEFT THE PRECIPITATION AS ALL RAIN BUT SNOW MAY HAVE TO BE ADDED LATER AS WE GET A BETTER SAMPLING OF HOW THIS SYSTEM WILL PLAY OUT. MARINE... AN UPPER LEVEL TROUGH OF LOW PRESSURE AND ASSOCIATED WEAK SURFACE REFLECTION WILL BRING UNSETTLED WEATHER TO THE GREAT LAKES FOR THE NEXT COUPLE DAYS. SOUTHERLY FLOW AHEAD OF THE TROUGH IS BEGINNING TO SETTLE ALLOWING US TO CANCEL THE SMALL CRAFT ADVISORY OVER SAGINAW BAY A FEW HOURS EARLY BUT FLOW OVER LAKE HURON WILL WARRANT THE CONTINUATION OF THE NEARSHORE SMALL CRAFTS THROUGH THE EVENING WITH GUSTS AROUND 25 KNOTS AND ELEVATED WAVE HEIGHTS. THE TROUGH AXIS WILL TRACK ACROSS THE AREA TUESDAY VEERING WINDS AROUND TO THE NORTH. COLD AIR ADVECTION BEHIND A PASSING COLD FRONT OVER THE SLIGHTLY WARMER WATERS...WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE STALLING UPPER LEVEL TROUGH AND THE RIDGE TRYING TO BUILD IN FROM THE WEST WILL HELP EXCITE THE WIND FIELD ONCE AGAIN. A MARGINAL GALE WATCH CONTINUES FOR THE SOUTHERN LAKE HURON BASIN AS WINDS LOOK TO GUST NEAR 35 KNOTS WITH THIS SETUP. THE UPPER LEVEL FEATURE MAY TRY TO HEAD BACK WEST TOWARD THE AREA LATER IN THE WEEK WHICH WOULD KEEP SOME SEMBLANCE OF THE INCREASED NORTHERLY FLOW THROUGH MID WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR LHZ441>443-462>464. SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ441>443. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....BT SHORT TERM...DT LONG TERM....DRK/RK MARINE.......DRK YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
342 PM EST SUN DEC 7 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 338 PM EST SUN DEC 7 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE MOVING ACROSS MT EARLY THIS MORNING. THIS WAVE WILL BE THE FEATURE OF INTEREST IN THE SHORT TERM AS IT SHIFTS E...REACHING THE UPPER GREAT LAKES MON. AT THE SFC...SHORTWAVE WAS SUPPORTING LOW PRES OVER SRN SASKATCHEWAN. TO THE E...HIGH PRES CENTER HAS SLIPPED E OF LAKE SUPERIOR/UPPER MI. STRONG WAA/ISENTROPIC ASCENT REGIME BTWN THE SHORTWAVE AND DEPARTING HIGH PRES HAS LED TO QUITE A BIT OF MID LEVEL CLOUDINESS SPREADING INTO UPPER MI DURING THE NIGHT. RADARS ARE ALSO SHOWING RETURNS...BUT SO FAR...THE FARTHEST S ANY -SN HAS BEEN REPORTED IN OBS IS AT THUNDER BAY ONTARIO AS DRY AIR NOTED BELOW 750MB ON 00Z KINL SOUNDING IS WORKING TO LIMIT SOUTHWARD EXTENT OF -SN REACHING THE GROUND. TODAY...SHORTWAVE OVER MT WILL MOVE TO THE ERN DAKOTAS WITH ASSOCIATED SFC LOW REACHING FAR SE MANITOBA BY EVENING. STRONG WAA/ISENTROPIC ASCENT WHICH IS CURRENTLY FOCUSED INTO NRN MN WILL SHIFT E TODAY...BUT MODELS CONTINUE TO INDICATE THAT LOW-LEVELS WILL FAIL TO MOISTEN ACROSS UPPER MI DUE TO A PERSISTENT FEED OF LOW-LEVEL DRY AIR FROM DEPARTING HIGH PRES. TO THE W...AXIS OF 850-700MB MOISTURE TRANSPORT AND LOWERING CONDENSATION PRES DEFICITS AHEAD OF SHORTWAVE REMAINS JUST W OF THE AREA THRU THE AFTN. SO... NOT EXPECTING ANY PCPN DURING THE DAYLIGHT HRS TODAY. TEMPS SHOULD REACH THE UPPER 20S/LWR 30S. TONIGHT...AS RIBBON OF 850-700MB MOISTURE TRANSPORT...ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-50KT AND DEEP LAYER QVECTOR CONVERGENCE IN ADVANCE OF APPROACHING SHORTWAVE TRANSLATE W-E... CATEGORICAL POPS STILL APPEAR ON TRACK...SPREADING INTO WRN UPPER MI THIS EVENING AND INTO THE CNTRL OVERNIGHT. SNOW MAY NOT REACH THE FAR E AROUND KERY UNTIL TOWARD 12Z. AVERAGED MODEL QPF INDICATES 0.1 TO 0.2 INCHES OF QPF TONIGHT...SUGGESTING 1-2 INCHES OF SNOW IN GENERAL AS SNOW TO WATER RATIOS SHOULDN`T BE MUCH MORE THAN 10-12 TO 1. THESE NUMBERS APPEAR ON TRACK FROM AN ISENTROPIC STANDPOINT AS MIXING RATIOS OF AROUND 3G/KG ARE AVBL WITH CLOSE TO 6HRS OF ASCENT. SNOW ACCUMULATIONS WILL BE LIGHTEST OVER THE E SINCE SNOW DOESN`T BEGIN UNTIL NEAR THE END OF THE TONIGHT PERIOD. CLOUDS/PCPN/WINDS WILL KEEP TEMPS FROM FALLING MORE THAN ROUGHLY 2-4 DEGREES FROM TODAYS HIGH TEMPS. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 323 PM EST SUN DEC 7 2014 GOOD AGREEMENT IN LARGER SCALE PATTERN THROUGH THE LENGTH OF THE LONG TERM INTO NEXT WEEKEND. LOW PRESSURE THAT CROSSES THE AREA ON MONDAY WILL BE WEAKENING AS IS SLIDES EAST OF LK SUPERIOR BY TUESDAY MORNING. NNW FLOW LAKE ENHANCEMENT...AT LEAST IN DIMINISHING STATE...EXPECTED MONDAY EVENING OVER WESTERN UPR MICHIGAN...ESPECIALLY OVER THE KEWEENAW WHERE DEEPER MOISTURE TO H7 LINGERS AND H85 TEMPS DROP TO AROUND -8C. LOW-LEVEL WINDS NOT TOO CYCLONIC SO CONVERGENCE WILL BE WEAK. SNOW ACCUMS MONDAY EVENING SHOULD BE NOTHING MORE THAN A COUPLE INCHES FOR NW CWA. DEPARTING DEEP MOISTURE AND LIMITED COLD AIR /H9-H85 TEMPS -8C TO -10C/ IS MARGINAL FOR PURE LAKE EFFECT...SO SNOW SHOWERS SHOULD DIMINISH SHARPLY AFTER MIDNIGHT ALL CWA. LIGHT LES COULD CONTINUE INTO TUESDAY MORNING...BUT CONTINUED DRYING AND SFC RIDGING WILL SPELL AN END TO LES TUE AFTN. BEYOND MONDAY NIGHT...APPEARS QUIET WITH NO BIG STORMS OVER THE UPPER GREAT LAKES. UPPER LEVEL FLOW FEATURES RIDGING BUILDING OVER THE MID PORTION OF THE CONUS MID TO LATE WEEK. MEANWHILE...DEEPENING TROUGH OVER THE EASTERN CONUS WILL RESULT IN STRONG EAST COAST STORM THAT WILL BRING HEAVY SNOW TO INTERIOR PORTIONS OF THE NORTHEAST AND NEW ENGLAND. THE BUILDING UPR RIDGE WILL LEAD TO SPRAWLING SFC RIDGE FM CENTRAL PLAINS AND NORTHERN ONTARIO ON TUESDAY ONLY MOVING SLOWLY TO NORTHERN QUEBEC TO LOWER MISSISSIPPI RIVER VALLEY BY FRIDAY. COULD BE A COUPLE CHILLY NIGHTS INLAND ON TUESDAY NIGHT AND WEDNESDAY NIGHT WITH THE RIDGE OVERHEAD AND AS PWATS ARE BLO 75 PCT OF NORMAL. DEPENDING ON CLOUD COVER...MINS EITHER NIGHT MAY FALL TOWARD ZERO. FOR NOW HAVE SOME SINGLE DIGITS ABOVE ZERO IN THERE UNTIL CAN GET BETTER HANDLE ON EXTENT OF MID CLOUDS. BY NEXT WEEKEND UPPER LEVEL RIDGE AXIS IS OVER THE WESTERN GREAT LAKES. SW FLOW SFC-H85 WILL TRANSPORT HIGHER DWPNTS FM THE CNTRL PLAINS INTO THE GREAT LAKES. YET IT IS NOT UNTIL SATURDAY NIGHT INTO SUNDAY THAT SFC DWPNTS ARE FORECAST TO BE OVER 32F. SOUNDINGS FM GFS INDICATE SHALLOWER MOISTURE THAN THEY SHOWED YDY FOR FRIDAY AND SATURDAY...SO COULD HAVE AT LEAST SOME SUNSHINE WHICH WOULD ALLOW TEMPS TO WARM INTO THE MID 30S TO LOWER 40S. SHOT UP SLIGHTLY HIGHER THAN BLENDED GUIDANCE. ONCE DWPNTS RISE ABOVE FREEZING SATURDAY NIGHT INTO SUNDAY...THERE WILL BE INCREASING PROSPECTS OF DRIZZLE AND FOG AS THIS MOISTURE RIDES OVER GRADUAL MELTING SNOWPACK. ECMWF AND GFS ALSO INDICATE MOISTURE DEPTH INCREASES WITH SOME WEAK LIFT DEVELOPING DUE TO SHORTWAVE ENERGY WORKING OVER THE AREA OUT AHEAD OF TROUGH AXIS OVER WESTERN CONUS. WILL HAVE SMALL POPS IN THERE FOR RAIN LATE IN THE WEEKEND. ALSO WILL INCLUDE MENTION OF FOG SINCE DWPNTS ARE FORECAST IN THE MID-UPR 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 125 PM EST SUN DEC 7 2014 TIGHTENING PRES GRADIENT BTWN EXITING HIGH PRES TO THE E AND LOW PRES APPROACHES FROM THE W WILL LEAD TO SOUTHERLY WINDS GUSTING OVER 20 KT THIS AFTERNOON INTO THIS EVENING. OTHERWISE...WITH LOW-LEVELS REMAINING DRY...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW INTO EARLY EVENING. TONIGHT...-SN DEVELOPING AHEAD OF THE APPROACHING LOW PRES SYSTEM WILL SPREAD E INTO UPPER MI. ALL TERMINALS WILL FALL TO MVFR. WITH SOMEWHAT HEAVIER SNOW EXPECTED AT KCMX/KSAW...THERE MAY BE SOME PERIODS OF IFR VIS. LOOK FOR ALL SITES TO LOWER TO IFR CIGS BY MON MORNING AS LOW-LVL MOISTURE GETS TRAPPED UNDER LOWERING SUBSIDENCE INVERSION. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 338 PM EST SUN DEC 7 2014 TIGHTENING PRES GRADIENT AND PRES FALLS SHIFTING INTO THE UPPER LAKES AHEAD OF AN APPROACHING LOW PRES WILL RESULT IN SOUTHERLY GALES TONIGHT INTO MONDAY MORNING OVER THE EAST HALF OF LAKE SUPERIOR. WINDS OVER THE W WL STAY MOSTLY BLO 30KT. AS LOW PRES/COLD FRONT MOVE ACROSS THE UPPER LAKES LATE MON/MON EVENING...WINDS WILL SHIFT TO THE NW-N. WITH SYSTEM TRENDING WEAKER AS IT DEPARTS...EXPECT WINDS TO STAY BLO GALES MON NIGHT INTO TUE...NO HIGHER THAN 30KT MAINLY CENTRAL AND EAST. HIGH PRES RIDGE ARRIVING TUE NIGHT/WED MAY LINGER INTO THE END OF THE WEEK AND RESULT IN WINDS UNDER 20KT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST MONDAY FOR LSZ267. GALE WARNING UNTIL 10 AM EST MONDAY FOR LSZ266. GALE WARNING UNTIL 3 AM EST MONDAY FOR LSZ248-249-265. GALE WARNING FROM 7 PM THIS EVENING TO 3 AM EST MONDAY FOR LSZ250. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...JLA AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
327 PM EST SUN DEC 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 538 AM EST SUN DEC 7 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE MOVING ACROSS MT EARLY THIS MORNING. THIS WAVE WILL BE THE FEATURE OF INTEREST IN THE SHORT TERM AS IT SHIFTS E...REACHING THE UPPER GREAT LAKES MON. AT THE SFC...SHORTWAVE WAS SUPPORTING LOW PRES OVER SRN SASKATCHEWAN. TO THE E...HIGH PRES CENTER HAS SLIPPED E OF LAKE SUPERIOR/UPPER MI. STRONG WAA/ISENTROPIC ASCENT REGIME BTWN THE SHORTWAVE AND DEPARTING HIGH PRES HAS LED TO QUITE A BIT OF MID LEVEL CLOUDINESS SPREADING INTO UPPER MI DURING THE NIGHT. RADARS ARE ALSO SHOWING RETURNS...BUT SO FAR...THE FARTHEST S ANY -SN HAS BEEN REPORTED IN OBS IS AT THUNDER BAY ONTARIO AS DRY AIR NOTED BELOW 750MB ON 00Z KINL SOUNDING IS WORKING TO LIMIT SOUTHWARD EXTENT OF -SN REACHING THE GROUND. TODAY...SHORTWAVE OVER MT WILL MOVE TO THE ERN DAKOTAS WITH ASSOCIATED SFC LOW REACHING FAR SE MANITOBA BY EVENING. STRONG WAA/ISENTROPIC ASCENT WHICH IS CURRENTLY FOCUSED INTO NRN MN WILL SHIFT E TODAY...BUT MODELS CONTINUE TO INDICATE THAT LOW-LEVELS WILL FAIL TO MOISTEN ACROSS UPPER MI DUE TO A PERSISTENT FEED OF LOW-LEVEL DRY AIR FROM DEPARTING HIGH PRES. TO THE W...AXIS OF 850-700MB MOISTURE TRANSPORT AND LOWERING CONDENSATION PRES DEFICITS AHEAD OF SHORTWAVE REMAINS JUST W OF THE AREA THRU THE AFTN. SO... NOT EXPECTING ANY PCPN DURING THE DAYLIGHT HRS TODAY. TEMPS SHOULD REACH THE UPPER 20S/LWR 30S. TONIGHT...AS RIBBON OF 850-700MB MOISTURE TRANSPORT...ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-50KT AND DEEP LAYER QVECTOR CONVERGENCE IN ADVANCE OF APPROACHING SHORTWAVE TRANSLATE W-E... CATEGORICAL POPS STILL APPEAR ON TRACK...SPREADING INTO WRN UPPER MI THIS EVENING AND INTO THE CNTRL OVERNIGHT. SNOW MAY NOT REACH THE FAR E AROUND KERY UNTIL TOWARD 12Z. AVERAGED MODEL QPF INDICATES 0.1 TO 0.2 INCHES OF QPF TONIGHT...SUGGESTING 1-2 INCHES OF SNOW IN GENERAL AS SNOW TO WATER RATIOS SHOULDN`T BE MUCH MORE THAN 10-12 TO 1. THESE NUMBERS APPEAR ON TRACK FROM AN ISENTROPIC STANDPOINT AS MIXING RATIOS OF AROUND 3G/KG ARE AVBL WITH CLOSE TO 6HRS OF ASCENT. SNOW ACCUMULATIONS WILL BE LIGHTEST OVER THE E SINCE SNOW DOESN`T BEGIN UNTIL NEAR THE END OF THE TONIGHT PERIOD. CLOUDS/PCPN/WINDS WILL KEEP TEMPS FROM FALLING MORE THAN ROUGHLY 2-4 DEGREES FROM TODAYS HIGH TEMPS. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 323 PM EST SUN DEC 7 2014 GOOD AGREEMENT IN LARGER SCALE PATTERN THROUGH THE LENGTH OF THE LONG TERM INTO NEXT WEEKEND. LOW PRESSURE THAT CROSSES THE AREA ON MONDAY WILL BE WEAKENING AS IS SLIDES EAST OF LK SUPERIOR BY TUESDAY MORNING. NNW FLOW LAKE ENHANCEMENT...AT LEAST IN DIMINISHING STATE...EXPECTED MONDAY EVENING OVER WESTERN UPR MICHIGAN...ESPECIALLY OVER THE KEWEENAW WHERE DEEPER MOISTURE TO H7 LINGERS AND H85 TEMPS DROP TO AROUND -8C. LOW-LEVEL WINDS NOT TOO CYCLONIC SO CONVERGENCE WILL BE WEAK. SNOW ACCUMS MONDAY EVENING SHOULD BE NOTHING MORE THAN A COUPLE INCHES FOR NW CWA. DEPARTING DEEP MOISTURE AND LIMITED COLD AIR /H9-H85 TEMPS -8C TO -10C/ IS MARGINAL FOR PURE LAKE EFFECT...SO SNOW SHOWERS SHOULD DIMINISH SHARPLY AFTER MIDNIGHT ALL CWA. LIGHT LES COULD CONTINUE INTO TUESDAY MORNING...BUT CONTINUED DRYING AND SFC RIDGING WILL SPELL AN END TO LES TUE AFTN. BEYOND MONDAY NIGHT...APPEARS QUIET WITH NO BIG STORMS OVER THE UPPER GREAT LAKES. UPPER LEVEL FLOW FEATURES RIDGING BUILDING OVER THE MID PORTION OF THE CONUS MID TO LATE WEEK. MEANWHILE...DEEPENING TROUGH OVER THE EASTERN CONUS WILL RESULT IN STRONG EAST COAST STORM THAT WILL BRING HEAVY SNOW TO INTERIOR PORTIONS OF THE NORTHEAST AND NEW ENGLAND. THE BUILDING UPR RIDGE WILL LEAD TO SPRAWLING SFC RIDGE FM CENTRAL PLAINS AND NORTHERN ONTARIO ON TUESDAY ONLY MOVING SLOWLY TO NORTHERN QUEBEC TO LOWER MISSISSIPPI RIVER VALLEY BY FRIDAY. COULD BE A COUPLE CHILLY NIGHTS INLAND ON TUESDAY NIGHT AND WEDNESDAY NIGHT WITH THE RIDGE OVERHEAD AND AS PWATS ARE BLO 75 PCT OF NORMAL. DEPENDING ON CLOUD COVER...MINS EITHER NIGHT MAY FALL TOWARD ZERO. FOR NOW HAVE SOME SINGLE DIGITS ABOVE ZERO IN THERE UNTIL CAN GET BETTER HANDLE ON EXTENT OF MID CLOUDS. BY NEXT WEEKEND UPPER LEVEL RIDGE AXIS IS OVER THE WESTERN GREAT LAKES. SW FLOW SFC-H85 WILL TRANSPORT HIGHER DWPNTS FM THE CNTRL PLAINS INTO THE GREAT LAKES. YET IT IS NOT UNTIL SATURDAY NIGHT INTO SUNDAY THAT SFC DWPNTS ARE FORECAST TO BE OVER 32F. SOUNDINGS FM GFS INDICATE SHALLOWER MOISTURE THAN THEY SHOWED YDY FOR FRIDAY AND SATURDAY...SO COULD HAVE AT LEAST SOME SUNSHINE WHICH WOULD ALLOW TEMPS TO WARM INTO THE MID 30S TO LOWER 40S. SHOT UP SLIGHTLY HIGHER THAN BLENDED GUIDANCE. ONCE DWPNTS RISE ABOVE FREEZING SATURDAY NIGHT INTO SUNDAY...THERE WILL BE INCREASING PROSPECTS OF DRIZZLE AND FOG AS THIS MOISTURE RIDES OVER GRADUAL MELTING SNOWPACK. ECMWF AND GFS ALSO INDICATE MOISTURE DEPTH INCREASES WITH SOME WEAK LIFT DEVELOPING DUE TO SHORTWAVE ENERGY WORKING OVER THE AREA OUT AHEAD OF TROUGH AXIS OVER WESTERN CONUS. WILL HAVE SMALL POPS IN THERE FOR RAIN LATE IN THE WEEKEND. ALSO WILL INCLUDE MENTION OF FOG SINCE DWPNTS ARE FORECAST IN THE MID-UPR 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 125 PM EST SUN DEC 7 2014 TIGHTENING PRES GRADIENT BTWN EXITING HIGH PRES TO THE E AND LOW PRES APPROACHES FROM THE W WILL LEAD TO SOUTHERLY WINDS GUSTING OVER 20 KT THIS AFTERNOON INTO THIS EVENING. OTHERWISE...WITH LOW-LEVELS REMAINING DRY...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW INTO EARLY EVENING. TONIGHT...-SN DEVELOPING AHEAD OF THE APPROACHING LOW PRES SYSTEM WILL SPREAD E INTO UPPER MI. ALL TERMINALS WILL FALL TO MVFR. WITH SOMEWHAT HEAVIER SNOW EXPECTED AT KCMX/KSAW...THERE MAY BE SOME PERIODS OF IFR VIS. LOOK FOR ALL SITES TO LOWER TO IFR CIGS BY MON MORNING AS LOW-LVL MOISTURE GETS TRAPPED UNDER LOWERING SUBSIDENCE INVERSION. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 538 AM EST SUN DEC 7 2014 TIGHTENING PRES GRADIENT AND PRES FALLS SHIFTING INTO THE UPPER LAKES AHEAD OF APPROACHING LOW PRES WILL RESULT IN INCREASING SOUTHERLY WINDS TODAY/TONIGHT. ACROSS THE E HALF OF LAKE SUPERIOR... WIND GUSTS WILL LIKELY REACH GALE FORCE LATER THIS AFTN THRU TONIGHT WHILE WINDS OVER THE W STAY MOSTLY BLO 30KT. AS LOW PRES/COLD FRONT MOVE ACROSS THE UPPER LAKES LATE MON/MON EVENING...WINDS WILL SHIFT TO THE NW-N. WITH SYSTEM TRENDING WEAKER AS IT DEPARTS...THESE WINDS WILL LIKELY NOT BE AS STRONG AS PREVIOUSLY THOUGHT. SO...IT NOW APPEARS GALES PROBABLY WON`T OCCUR ON THE BACKSIDE OF THE SYSTEM MON NIGHT INTO EARLY TUE. HIGH PRES RIDGE ARRIVING TUE NIGHT/WED WILL BRING A PERIOD OF LIGHTER WINDS UNDER 20KT THAT MAY LINGER ON THRU THU AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST MONDAY FOR LSZ267. GALE WARNING UNTIL 10 AM EST MONDAY FOR LSZ266. GALE WARNING UNTIL 3 AM EST MONDAY FOR LSZ248-249-265. GALE WARNING FROM 7 PM THIS EVENING TO 3 AM EST MONDAY FOR LSZ250. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 PM EST SUN DEC 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 538 AM EST SUN DEC 7 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE MOVING ACROSS MT EARLY THIS MORNING. THIS WAVE WILL BE THE FEATURE OF INTEREST IN THE SHORT TERM AS IT SHIFTS E...REACHING THE UPPER GREAT LAKES MON. AT THE SFC...SHORTWAVE WAS SUPPORTING LOW PRES OVER SRN SASKATCHEWAN. TO THE E...HIGH PRES CENTER HAS SLIPPED E OF LAKE SUPERIOR/UPPER MI. STRONG WAA/ISENTROPIC ASCENT REGIME BTWN THE SHORTWAVE AND DEPARTING HIGH PRES HAS LED TO QUITE A BIT OF MID LEVEL CLOUDINESS SPREADING INTO UPPER MI DURING THE NIGHT. RADARS ARE ALSO SHOWING RETURNS...BUT SO FAR...THE FARTHEST S ANY -SN HAS BEEN REPORTED IN OBS IS AT THUNDER BAY ONTARIO AS DRY AIR NOTED BELOW 750MB ON 00Z KINL SOUNDING IS WORKING TO LIMIT SOUTHWARD EXTENT OF -SN REACHING THE GROUND. TODAY...SHORTWAVE OVER MT WILL MOVE TO THE ERN DAKOTAS WITH ASSOCIATED SFC LOW REACHING FAR SE MANITOBA BY EVENING. STRONG WAA/ISENTROPIC ASCENT WHICH IS CURRENTLY FOCUSED INTO NRN MN WILL SHIFT E TODAY...BUT MODELS CONTINUE TO INDICATE THAT LOW-LEVELS WILL FAIL TO MOISTEN ACROSS UPPER MI DUE TO A PERSISTENT FEED OF LOW-LEVEL DRY AIR FROM DEPARTING HIGH PRES. TO THE W...AXIS OF 850-700MB MOISTURE TRANSPORT AND LOWERING CONDENSATION PRES DEFICITS AHEAD OF SHORTWAVE REMAINS JUST W OF THE AREA THRU THE AFTN. SO... NOT EXPECTING ANY PCPN DURING THE DAYLIGHT HRS TODAY. TEMPS SHOULD REACH THE UPPER 20S/LWR 30S. TONIGHT...AS RIBBON OF 850-700MB MOISTURE TRANSPORT...ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-50KT AND DEEP LAYER QVECTOR CONVERGENCE IN ADVANCE OF APPROACHING SHORTWAVE TRANSLATE W-E... CATEGORICAL POPS STILL APPEAR ON TRACK...SPREADING INTO WRN UPPER MI THIS EVENING AND INTO THE CNTRL OVERNIGHT. SNOW MAY NOT REACH THE FAR E AROUND KERY UNTIL TOWARD 12Z. AVERAGED MODEL QPF INDICATES 0.1 TO 0.2 INCHES OF QPF TONIGHT...SUGGESTING 1-2 INCHES OF SNOW IN GENERAL AS SNOW TO WATER RATIOS SHOULDN`T BE MUCH MORE THAN 10-12 TO 1. THESE NUMBERS APPEAR ON TRACK FROM AN ISENTROPIC STANDPOINT AS MIXING RATIOS OF AROUND 3G/KG ARE AVBL WITH CLOSE TO 6HRS OF ASCENT. SNOW ACCUMULATIONS WILL BE LIGHTEST OVER THE E SINCE SNOW DOESN`T BEGIN UNTIL NEAR THE END OF THE TONIGHT PERIOD. CLOUDS/PCPN/WINDS WILL KEEP TEMPS FROM FALLING MORE THAN ROUGHLY 2-4 DEGREES FROM TODAYS HIGH TEMPS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 407 AM EST SUN DEC 7 2014 MODELS ARE IN GOOD AGREEMENT MON THROUGH THU...WITH LESS AGREEMENT FRI AND SAT. A SHORTWAVE WILL MOVE FROM WRN LAKE SUPERIOR TO NRN LAKE SUPERIOR THEN TO ERN LAKE SUPERIOR STEADILY BETWEEN 12Z MON AND 06Z TUE. THIS WILL BRING A WEAKENING/BROADENING 1012-1016MB SFC LOW ACROSS THE AREA AS THE SHORTWAVE MOVES ACROSS. THERMAL PROFILES WILL SUPPORT ALL SNOW WITH THE EVENT FROM 12Z MON ON...BUT 850MB TEMPS ONLY FALL TO A MINIMUM OF -8C AT 12Z TUE...WHICH IS WARMER THAN PREVIOUS RUNS. THE DRY SLOT LOOKS TO BE MOVING INTO WRN UPPER MI AROUND 12Z MON AS THE BEST FORCING IS OVER THE ERN CWA AND NRN LAKE SUPERIOR. HAVE FOCUSED HIGHEST POPS IN THESE AREAS IN THE MORNING...SHIFTING NE THROUGH THE DAY. WITH THE WRAP AROUND MOISTURE AND COOL UPSLOPE FLOW...LAKE ENHANCED/UPSLOPE PRECIP WILL BECOME THE FOCUS MON EVENING/MON NIGHT BEFORE DIMINISHING TUE AS A 1034MB SFC RIDGE MOVES OVER LAKE SUPERIOR. DID REDUCE LAKE ENHANCED/UPSLOPE POPS AS MODELS TREND WARMER WITH LOW LEVEL TEMPS. FOR MON THROUGH TUE...GENERALLY HAVE SNOWFALL AMOUNTS OF 2-3 INCHES CLOSER TO LAKE SUPERIOR...WITH 1 INCH OR SO INLAND. UPPER RIDGING BUILDS INTO THE AREA THROUGH THE REST OF THE EXTENDED WITH NO SIGNIFICANT SIGNAL FOR PRECIP. TEMPS WILL BE ON THE INCREASE...WITH 850MB TEMPS INCREASING TO ABOVE 0C BY THU MORNING AND MAKING IT UP TO AROUND 10C FRI NIGHT INTO SAT. OF COURSE...TEMPERATURE INVERSION NEAR THE SFC WILL BE PRETTY STRONG SO SFC TEMPS WILL BE MORE LIMITED...BUT COULD SEE HIGHS IN THE LOW 40S IN SOME LOCATIONS ON SAT. MODELS DO SHOW A FEW HUNDREDTHS OF AN INCH OF QPF FRI INTO SAT...BUT THINK THAT IS DUE TO MODELS OVERDOING LOW LEVEL MOISTURE AS THEY NORMALLY DO WHEN THEY SIMULATE SNOWPACK MELTING. DID NOT INCLUDE PRECIP IN THE FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 125 PM EST SUN DEC 7 2014 TIGHTENING PRES GRADIENT BTWN EXITING HIGH PRES TO THE E AND LOW PRES APPROACHES FROM THE W WILL LEAD TO SOUTHERLY WINDS GUSTING OVER 20 KT THIS AFTERNOON INTO THIS EVENING. OTHERWISE...WITH LOW-LEVELS REMAINING DRY...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW INTO EARLY EVENING. TONIGHT...-SN DEVELOPING AHEAD OF THE APPROACHING LOW PRES SYSTEM WILL SPREAD E INTO UPPER MI. ALL TERMINALS WILL FALL TO MVFR. WITH SOMEWHAT HEAVIER SNOW EXPECTED AT KCMX/KSAW...THERE MAY BE SOME PERIODS OF IFR VIS. LOOK FOR ALL SITES TO LOWER TO IFR CIGS BY MON MORNING AS LOW-LVL MOISTURE GETS TRAPPED UNDER LOWERING SUBSIDENCE INVERSION. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 538 AM EST SUN DEC 7 2014 TIGHTENING PRES GRADIENT AND PRES FALLS SHIFTING INTO THE UPPER LAKES AHEAD OF APPROACHING LOW PRES WILL RESULT IN INCREASING SOUTHERLY WINDS TODAY/TONIGHT. ACROSS THE E HALF OF LAKE SUPERIOR... WIND GUSTS WILL LIKELY REACH GALE FORCE LATER THIS AFTN THRU TONIGHT WHILE WINDS OVER THE W STAY MOSTLY BLO 30KT. AS LOW PRES/COLD FRONT MOVE ACROSS THE UPPER LAKES LATE MON/MON EVENING...WINDS WILL SHIFT TO THE NW-N. WITH SYSTEM TRENDING WEAKER AS IT DEPARTS...THESE WINDS WILL LIKELY NOT BE AS STRONG AS PREVIOUSLY THOUGHT. SO...IT NOW APPEARS GALES PROBABLY WON`T OCCUR ON THE BACKSIDE OF THE SYSTEM MON NIGHT INTO EARLY TUE. HIGH PRES RIDGE ARRIVING TUE NIGHT/WED WILL BRING A PERIOD OF LIGHTER WINDS UNDER 20KT THAT MAY LINGER ON THRU THU AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST MONDAY FOR LSZ267. GALE WARNING UNTIL 10 AM EST MONDAY FOR LSZ266. GALE WARNING FROM 6 PM THIS EVENING TO 3 AM EST MONDAY FOR LSZ248-249-265. GALE WARNING FROM 7 PM THIS EVENING TO 3 AM EST MONDAY FOR LSZ250. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
633 AM EST SUN DEC 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 538 AM EST SUN DEC 7 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE MOVING ACROSS MT EARLY THIS MORNING. THIS WAVE WILL BE THE FEATURE OF INTEREST IN THE SHORT TERM AS IT SHIFTS E...REACHING THE UPPER GREAT LAKES MON. AT THE SFC...SHORTWAVE WAS SUPPORTING LOW PRES OVER SRN SASKATCHEWAN. TO THE E...HIGH PRES CENTER HAS SLIPPED E OF LAKE SUPERIOR/UPPER MI. STRONG WAA/ISENTROPIC ASCENT REGIME BTWN THE SHORTWAVE AND DEPARTING HIGH PRES HAS LED TO QUITE A BIT OF MID LEVEL CLOUDINESS SPREADING INTO UPPER MI DURING THE NIGHT. RADARS ARE ALSO SHOWING RETURNS...BUT SO FAR...THE FARTHEST S ANY -SN HAS BEEN REPORTED IN OBS IS AT THUNDER BAY ONTARIO AS DRY AIR NOTED BELOW 750MB ON 00Z KINL SOUNDING IS WORKING TO LIMIT SOUTHWARD EXTENT OF -SN REACHING THE GROUND. TODAY...SHORTWAVE OVER MT WILL MOVE TO THE ERN DAKOTAS WITH ASSOCIATED SFC LOW REACHING FAR SE MANITOBA BY EVENING. STRONG WAA/ISENTROPIC ASCENT WHICH IS CURRENTLY FOCUSED INTO NRN MN WILL SHIFT E TODAY...BUT MODELS CONTINUE TO INDICATE THAT LOW-LEVELS WILL FAIL TO MOISTEN ACROSS UPPER MI DUE TO A PERSISTENT FEED OF LOW-LEVEL DRY AIR FROM DEPARTING HIGH PRES. TO THE W...AXIS OF 850-700MB MOISTURE TRANSPORT AND LOWERING CONDENSATION PRES DEFICITS AHEAD OF SHORTWAVE REMAINS JUST W OF THE AREA THRU THE AFTN. SO... NOT EXPECTING ANY PCPN DURING THE DAYLIGHT HRS TODAY. TEMPS SHOULD REACH THE UPPER 20S/LWR 30S. TONIGHT...AS RIBBON OF 850-700MB MOISTURE TRANSPORT...ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-50KT AND DEEP LAYER QVECTOR CONVERGENCE IN ADVANCE OF APPROACHING SHORTWAVE TRANSLATE W-E... CATEGORICAL POPS STILL APPEAR ON TRACK...SPREADING INTO WRN UPPER MI THIS EVENING AND INTO THE CNTRL OVERNIGHT. SNOW MAY NOT REACH THE FAR E AROUND KERY UNTIL TOWARD 12Z. AVERAGED MODEL QPF INDICATES 0.1 TO 0.2 INCHES OF QPF TONIGHT...SUGGESTING 1-2 INCHES OF SNOW IN GENERAL AS SNOW TO WATER RATIOS SHOULDN`T BE MUCH MORE THAN 10-12 TO 1. THESE NUMBERS APPEAR ON TRACK FROM AN ISENTROPIC STANDPOINT AS MIXING RATIOS OF AROUND 3G/KG ARE AVBL WITH CLOSE TO 6HRS OF ASCENT. SNOW ACCUMULATIONS WILL BE LIGHTEST OVER THE E SINCE SNOW DOESN`T BEGIN UNTIL NEAR THE END OF THE TONIGHT PERIOD. CLOUDS/PCPN/WINDS WILL KEEP TEMPS FROM FALLING MORE THAN ROUGHLY 2-4 DEGREES FROM TODAYS HIGH TEMPS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 407 AM EST SUN DEC 7 2014 MODELS ARE IN GOOD AGREEMENT MON THROUGH THU...WITH LESS AGREEMENT FRI AND SAT. A SHORTWAVE WILL MOVE FROM WRN LAKE SUPERIOR TO NRN LAKE SUPERIOR THEN TO ERN LAKE SUPERIOR STEADILY BETWEEN 12Z MON AND 06Z TUE. THIS WILL BRING A WEAKENING/BROADENING 1012-1016MB SFC LOW ACROSS THE AREA AS THE SHORTWAVE MOVES ACROSS. THERMAL PROFILES WILL SUPPORT ALL SNOW WITH THE EVENT FROM 12Z MON ON...BUT 850MB TEMPS ONLY FALL TO A MINIMUM OF -8C AT 12Z TUE...WHICH IS WARMER THAN PREVIOUS RUNS. THE DRY SLOT LOOKS TO BE MOVING INTO WRN UPPER MI AROUND 12Z MON AS THE BEST FORCING IS OVER THE ERN CWA AND NRN LAKE SUPERIOR. HAVE FOCUSED HIGHEST POPS IN THESE AREAS IN THE MORNING...SHIFTING NE THROUGH THE DAY. WITH THE WRAP AROUND MOISTURE AND COOL UPSLOPE FLOW...LAKE ENHANCED/UPSLOPE PRECIP WILL BECOME THE FOCUS MON EVENING/MON NIGHT BEFORE DIMINISHING TUE AS A 1034MB SFC RIDGE MOVES OVER LAKE SUPERIOR. DID REDUCE LAKE ENHANCED/UPSLOPE POPS AS MODELS TREND WARMER WITH LOW LEVEL TEMPS. FOR MON THROUGH TUE...GENERALLY HAVE SNOWFALL AMOUNTS OF 2-3 INCHES CLOSER TO LAKE SUPERIOR...WITH 1 INCH OR SO INLAND. UPPER RIDGING BUILDS INTO THE AREA THROUGH THE REST OF THE EXTENDED WITH NO SIGNIFICANT SIGNAL FOR PRECIP. TEMPS WILL BE ON THE INCREASE...WITH 850MB TEMPS INCREASING TO ABOVE 0C BY THU MORNING AND MAKING IT UP TO AROUND 10C FRI NIGHT INTO SAT. OF COURSE...TEMPERATURE INVERSION NEAR THE SFC WILL BE PRETTY STRONG SO SFC TEMPS WILL BE MORE LIMITED...BUT COULD SEE HIGHS IN THE LOW 40S IN SOME LOCATIONS ON SAT. MODELS DO SHOW A FEW HUNDREDTHS OF AN INCH OF QPF FRI INTO SAT...BUT THINK THAT IS DUE TO MODELS OVERDOING LOW LEVEL MOISTURE AS THEY NORMALLY DO WHEN THEY SIMULATE SNOWPACK MELTING. DID NOT INCLUDE PRECIP IN THE FORECAST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 632 AM EST SUN DEC 7 2014 PRES GRADIENT WILL TIGHTEN TODAY AS HIGH PRES EXITS TO THE E AND LOW PRES APPROACHES FROM THE W. THIS WILL LEAD TO SOUTHERLY WINDS INCREASING AND BECOMING GUSTY. OTHERWISE...WITH LOW-LEVELS REMAINING DRY...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU THE AFTN. TONIGHT...-SN DEVELOPING AHEAD OF THE APPROACHING LOW PRES SYSTEM WILL SPREAD E INTO UPPER MI. ALL TERMINALS WILL FALL TO MVFR. WITH SOMEWHAT HEAVIER SNOW EXPECTED AT KCMX/KSAW...THERE MAY BE SOME PERIODS OF IFR VIS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 538 AM EST SUN DEC 7 2014 TIGHTENING PRES GRADIENT AND PRES FALLS SHIFTING INTO THE UPPER LAKES AHEAD OF APPROACHING LOW PRES WILL RESULT IN INCREASING SOUTHERLY WINDS TODAY/TONIGHT. ACROSS THE E HALF OF LAKE SUPERIOR... WIND GUSTS WILL LIKELY REACH GALE FORCE LATER THIS AFTN THRU TONIGHT WHILE WINDS OVER THE W STAY MOSTLY BLO 30KT. AS LOW PRES/COLD FRONT MOVE ACROSS THE UPPER LAKES LATE MON/MON EVENING...WINDS WILL SHIFT TO THE NW-N. WITH SYSTEM TRENDING WEAKER AS IT DEPARTS...THESE WINDS WILL LIKELY NOT BE AS STRONG AS PREVIOUSLY THOUGHT. SO...IT NOW APPEARS GALES PROBABLY WON`T OCCUR ON THE BACKSIDE OF THE SYSTEM MON NIGHT INTO EARLY TUE. HIGH PRES RIDGE ARRIVING TUE NIGHT/WED WILL BRING A PERIOD OF LIGHTER WINDS UNDER 20KT THAT MAY LINGER ON THRU THU AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST MONDAY FOR LSZ267. GALE WARNING FROM 2 PM THIS AFTERNOON TO 10 AM EST MONDAY FOR LSZ266. GALE WARNING FROM 6 PM THIS EVENING TO 3 AM EST MONDAY FOR LSZ248-249-265. GALE WARNING FROM 7 PM THIS EVENING TO 3 AM EST MONDAY FOR LSZ250. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
538 AM EST SUN DEC 7 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 538 AM EST SUN DEC 7 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE MOVING ACROSS MT EARLY THIS MORNING. THIS WAVE WILL BE THE FEATURE OF INTEREST IN THE SHORT TERM AS IT SHIFTS E...REACHING THE UPPER GREAT LAKES MON. AT THE SFC...SHORTWAVE WAS SUPPORTING LOW PRES OVER SRN SASKATCHEWAN. TO THE E...HIGH PRES CENTER HAS SLIPPED E OF LAKE SUPERIOR/UPPER MI. STRONG WAA/ISENTROPIC ASCENT REGIME BTWN THE SHORTWAVE AND DEPARTING HIGH PRES HAS LED TO QUITE A BIT OF MID LEVEL CLOUDINESS SPREADING INTO UPPER MI DURING THE NIGHT. RADARS ARE ALSO SHOWING RETURNS...BUT SO FAR...THE FARTHEST S ANY -SN HAS BEEN REPORTED IN OBS IS AT THUNDER BAY ONTARIO AS DRY AIR NOTED BELOW 750MB ON 00Z KINL SOUNDING IS WORKING TO LIMIT SOUTHWARD EXTENT OF -SN REACHING THE GROUND. TODAY...SHORTWAVE OVER MT WILL MOVE TO THE ERN DAKOTAS WITH ASSOCIATED SFC LOW REACHING FAR SE MANITOBA BY EVENING. STRONG WAA/ISENTROPIC ASCENT WHICH IS CURRENTLY FOCUSED INTO NRN MN WILL SHIFT E TODAY...BUT MODELS CONTINUE TO INDICATE THAT LOW-LEVELS WILL FAIL TO MOISTEN ACROSS UPPER MI DUE TO A PERSISTENT FEED OF LOW-LEVEL DRY AIR FROM DEPARTING HIGH PRES. TO THE W...AXIS OF 850-700MB MOISTURE TRANSPORT AND LOWERING CONDENSATION PRES DEFICITS AHEAD OF SHORTWAVE REMAINS JUST W OF THE AREA THRU THE AFTN. SO... NOT EXPECTING ANY PCPN DURING THE DAYLIGHT HRS TODAY. TEMPS SHOULD REACH THE UPPER 20S/LWR 30S. TONIGHT...AS RIBBON OF 850-700MB MOISTURE TRANSPORT...ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-50KT AND DEEP LAYER QVECTOR CONVERGENCE IN ADVANCE OF APPROACHING SHORTWAVE TRANSLATE W-E... CATEGORICAL POPS STILL APPEAR ON TRACK...SPREADING INTO WRN UPPER MI THIS EVENING AND INTO THE CNTRL OVERNIGHT. SNOW MAY NOT REACH THE FAR E AROUND KERY UNTIL TOWARD 12Z. AVERAGED MODEL QPF INDICATES 0.1 TO 0.2 INCHES OF QPF TONIGHT...SUGGESTING 1-2 INCHES OF SNOW IN GENERAL AS SNOW TO WATER RATIOS SHOULDN`T BE MUCH MORE THAN 10-12 TO 1. THESE NUMBERS APPEAR ON TRACK FROM AN ISENTROPIC STANDPOINT AS MIXING RATIOS OF AROUND 3G/KG ARE AVBL WITH CLOSE TO 6HRS OF ASCENT. SNOW ACCUMULATIONS WILL BE LIGHTEST OVER THE E SINCE SNOW DOESN`T BEGIN UNTIL NEAR THE END OF THE TONIGHT PERIOD. CLOUDS/PCPN/WINDS WILL KEEP TEMPS FROM FALLING MORE THAN ROUGHLY 2-4 DEGREES FROM TODAYS HIGH TEMPS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 407 AM EST SUN DEC 7 2014 MODELS ARE IN GOOD AGREEMENT MON THROUGH THU...WITH LESS AGREEMENT FRI AND SAT. A SHORTWAVE WILL MOVE FROM WRN LAKE SUPERIOR TO NRN LAKE SUPERIOR THEN TO ERN LAKE SUPERIOR STEADILY BETWEEN 12Z MON AND 06Z TUE. THIS WILL BRING A WEAKENING/BROADENING 1012-1016MB SFC LOW ACROSS THE AREA AS THE SHORTWAVE MOVES ACROSS. THERMAL PROFILES WILL SUPPORT ALL SNOW WITH THE EVENT FROM 12Z MON ON...BUT 850MB TEMPS ONLY FALL TO A MINIMUM OF -8C AT 12Z TUE...WHICH IS WARMER THAN PREVIOUS RUNS. THE DRY SLOT LOOKS TO BE MOVING INTO WRN UPPER MI AROUND 12Z MON AS THE BEST FORCING IS OVER THE ERN CWA AND NRN LAKE SUPERIOR. HAVE FOCUSED HIGHEST POPS IN THESE AREAS IN THE MORNING...SHIFTING NE THROUGH THE DAY. WITH THE WRAP AROUND MOISTURE AND COOL UPSLOPE FLOW...LAKE ENHANCED/UPSLOPE PRECIP WILL BECOME THE FOCUS MON EVENING/MON NIGHT BEFORE DIMINISHING TUE AS A 1034MB SFC RIDGE MOVES OVER LAKE SUPERIOR. DID REDUCE LAKE ENHANCED/UPSLOPE POPS AS MODELS TREND WARMER WITH LOW LEVEL TEMPS. FOR MON THROUGH TUE...GENERALLY HAVE SNOWFALL AMOUNTS OF 2-3 INCHES CLOSER TO LAKE SUPERIOR...WITH 1 INCH OR SO INLAND. UPPER RIDGING BUILDS INTO THE AREA THROUGH THE REST OF THE EXTENDED WITH NO SIGNIFICANT SIGNAL FOR PRECIP. TEMPS WILL BE ON THE INCREASE...WITH 850MB TEMPS INCREASING TO ABOVE 0C BY THU MORNING AND MAKING IT UP TO AROUND 10C FRI NIGHT INTO SAT. OF COURSE...TEMPERATURE INVERSION NEAR THE SFC WILL BE PRETTY STRONG SO SFC TEMPS WILL BE MORE LIMITED...BUT COULD SEE HIGHS IN THE LOW 40S IN SOME LOCATIONS ON SAT. MODELS DO SHOW A FEW HUNDREDTHS OF AN INCH OF QPF FRI INTO SAT...BUT THINK THAT IS DUE TO MODELS OVERDOING LOW LEVEL MOISTURE AS THEY NORMALLY DO WHEN THEY SIMULATE SNOWPACK MELTING. DID NOT INCLUDE PRECIP IN THE FORECAST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1210 AM EST SUN DEC 7 2014 MID CLOUDS WITH WAA AHEAD OF LOW PRESSURE MOVING INTO THE PLAINS WILL PREVAIL AT THE TAF SITES OVERNIGHT INTO TODAY. AS HIGH PRESSURE MOVES OFF TO THE EAST...SRLY WINDS WILL ALSO INCREASE TODAY AND BECOME GUSTY BY AFTERNOON ESPECIALLY AT IWD AND SAW. AS A DISTURBANCE AND THE PLAINS LOW MOVE INTO THE UPPER MS VALLEY...SOME LIGHT SNOW IS EXPECTED TO DEVELOP OVER WRN UPPER MI BY LATE EVENING WITH CIGS VSBY DROPPING INTO THE MVFR RANGE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 538 AM EST SUN DEC 7 2014 TIGHTENING PRES GRADIENT AND PRES FALLS SHIFTING INTO THE UPPER LAKES AHEAD OF APPROACHING LOW PRES WILL RESULT IN INCREASING SOUTHERLY WINDS TODAY/TONIGHT. ACROSS THE E HALF OF LAKE SUPERIOR... WIND GUSTS WILL LIKELY REACH GALE FORCE LATER THIS AFTN THRU TONIGHT WHILE WINDS OVER THE W STAY MOSTLY BLO 30KT. AS LOW PRES/COLD FRONT MOVE ACROSS THE UPPER LAKES LATE MON/MON EVENING...WINDS WILL SHIFT TO THE NW-N. WITH SYSTEM TRENDING WEAKER AS IT DEPARTS...THESE WINDS WILL LIKELY NOT BE AS STRONG AS PREVIOUSLY THOUGHT. SO...IT NOW APPEARS GALES PROBABLY WON`T OCCUR ON THE BACKSIDE OF THE SYSTEM MON NIGHT INTO EARLY TUE. HIGH PRES RIDGE ARRIVING TUE NIGHT/WED WILL BRING A PERIOD OF LIGHTER WINDS UNDER 20KT THAT MAY LINGER ON THRU THU AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST MONDAY FOR LSZ267. GALE WARNING FROM 2 PM THIS AFTERNOON TO 10 AM EST MONDAY FOR LSZ266. GALE WARNING FROM 6 PM THIS EVENING TO 3 AM EST MONDAY FOR LSZ248-249-265. GALE WARNING FROM 7 PM THIS EVENING TO 3 AM EST MONDAY FOR LSZ250. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...JLB MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1153 PM CST Sat Dec 6 2014 .UPDATE: Issued at 918 PM CST Sat Dec 6 2014 Primary meteorological elements of interest tonight are sky cover and temperatures. Complicated sky cover forecast as 11-3.9 micron channel is showing advection of the low stratus deck slowly to the WSW at around 15-20 knots. Concurrently...some thick cirrus is moving ahead of the next shortwave and spilling over midlevel ridge axis. Have updated grids to decrease the sky cover in the near term where stratus deck is moving out of before ramping opaque cloud cover back up due to the aforementioned thick cirrus shield. Other problem tonight as been temperatures as they have cooled off quickly in areas which have scattered out due to loss of low stratus deck. As a result...lowered temps in northeast Missouri and southwest Illinois a bit through 6-9Z before leveling off as cirrus overtakes the same region. Net result...not too much change from previous forecast`s overnight minimums. Gosselin && .SHORT TERM: (Through Late Tonight) Issued at 300 PM CST Sat Dec 6 2014 Low stratus located within the southern portion of a large high pressure system continues to dominate the region at mid afternoon. There has been a slow clearing trend to our north with the clearing line located near the MO/IA border into northern IL. This high pressure system will dominate tonight as it moves to the east with low level flow gradually veering to easterly by mid evening and then east-southeasterly overnight. Given the trends in the wind field, there will probably be additional southward clearing into the early evening then the northern edge will hold steady before retreating back northwest overnight. The RAP H950 RH is the only guidance that seems to have a decent handle on this evolution. The abundance of clouds tonight would suggest MOS guidance is too low on mins, with the coolest values expected across northeast MO and west central IL. Glass .LONG TERM: (Sunday through Next Saturday) Issued at 300 PM CST Sat Dec 6 2014 The high pressure system will continue to retreat on Sunday and this will keep low clouds prevalent. Add in high clouds and it will make for a mostly cloudy-cloudy day. There are some indications that southern portions of the CWA could see some clearing from the south of the low clouds, and hence warmer high temps are expected. The next threat of precipitation will come Sunday night into Monday morning. A short wave trof will dig into the mid-upper MS valley. The large scale ascent associated with this wave along increasing mid level moisture and low level warm advection should be sufficient to generate some spotty/scattered precipitation ahead of the attendant cold front. Temperature profiles indicate the precipitation should be in the form of rain, with the highest pops late Monday night across northeast MO and along and east of the MS River on Monday morning. Monday should be milder with decreasing clouds as first a prefrontal trof and then the cold front then sweeps through the area. Another brief round of cold air then dominates on Tuesday with expansive high pressure. The upper air pattern will be in transition during the extended period from Wednesday into next weekend. The eastern U.S. upper trof/low will be progressive lifting northeast and eventually off the Atlantic Seaboard. A northwest flow short wave in the wake of the slowly retreating trof looks to impact our area sometime late Wednesday into early Thursday, however present indications are any precipitation threat should be confined to western MO. Heights aloft then gradually rise in the wake of the shortwave trof and high pressure departs, leading to southerly low level flow Friday into the Saturday and a warming trend. Glass && .AVIATION: (For the 06z TAFs through 06z Sunday Night) Issued at 1135 PM CST Sat Dec 6 2014 Difficult ceiling forecast for the rest of the night. The low MVFR and IFR ceilings cleared rapidly from the northeast across the area and now west central and most of southwest Illinois as well as northeast Missouri and parts of east central Missouri are out of the low stuff. Hard to see much detail from satellite pictures at this time because of a blanket of rather dense cirrus clouds which has moved over the area; but best guess from surface obs and what I can see from satellite is that the clouds now stretch from near KMBY to KSUS to near KMVN. the southwest progress of the clearing appears to have slowed and it should stop over the next couple of hours as low level flow turns more to the east and then east-southeast. Should see some redevelopment in the clouds over areas that are now clear as this occurs. Regardless, think MVFR and IFR fog will likely prevail where clouds do not redevelop. Where clouds redevelop toward morning, expect ceilings to persist until late morning/early afternoon before scattering out. Fog should dissipate within an hour or two after sunrise. Specifics for KSTL: MVFR ceilings have pushed just to the southwest of Lambert at this hour. Expect the ceilings to stay to the southwest for a few hours before moving back over the terminal before sunrise. Timing and height of the clouds is uncertain at this time. Until then, expect current 5SM fog to thicken a bit, perhaps down to 2SM...tho I feel this is unlikely. Once clouds come back into the terminal, expect ceilings to persist through the morning and scatter out during the early afternoon due to daytime heating. Carney && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
621 PM CST MON DEC 8 2014 .SHORT TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 320 PM CST MON DEC 8 2014 THE PRIMARY FORECAST CONCERNS FOR TONIGHT AND TUESDAY ARE CLOUD COVER AND RESULTING TEMPERATURES. ATTENTION TURNS MORE TOWARD THE POTENTIAL FOR LOW CLOUDS/FOG/DRIZZLE WEDNESDAY INTO THURSDAY. LARGE SCALE 500 MB PATTERN AT 12Z HAD THE FOLLOWING MAIN FEATURES. A TROUGH WAS LOCATED TO OUR EAST/NORTHEAST...A RIDGE STRETCHED FROM THE SOUTHERN ROCKIES INTO ALASKA AND A BROAD TROUGH WAS OUT OVER THE PACIFIC. A CLOSED LOW SHOULD DEVELOP OUT OF THE TROUGH TO OUR EAST IN THE EAST CENTRAL PART OF THE UNITED STATES BY TUESDAY NIGHT. THAT FEATURE WILL THEN LIKELY WOBBLE INTO THE NORTHEAST STATES INTO SATURDAY. IN OUR AREA...GENERAL RIDGING OCCURS IN THE MID LEVELS BUT THERE WILL BE SOME SHORTWAVE ENERGY TRACKING EAST THROUGH THE MEAN RIDGE...MAKING THE PATTERN A BIT MESSY. THE TROUGH IN THE PACIFIC WILL BE PROGRESSIVE..AND BRING VERY WET WEATHER TO MUCH OF THE WEST COAST THIS WEEK. TONIGHT...CLOUD COVER IS PROBLEMATIC. LOW CLOUDS CURRENTLY IN A BAND FROM NORTHERN IOWA ACROSS PARTS OF SOUTH DAKOTA AND INTO WESTERN NORTH DAKOTA. THESE MAY TRY TO SINK SOUTHWARD INTO OUR AREA. THE MOST RECENT RAP AND HRRR MODEL RUNS TEND TO DISSIPATE THIS CLOUDINESS...BUT 12Z HIGH RESOLUTION NAM AND GFS DID BRING THE LOW LEVEL MOISTURE SOUTHWARD. EVENING SHIFT WILL NEED TO MONITOR. A COLD FRONT WAS ALREADY TRACKING SOUTHWARD INTO NORTHEAST NEBRASKA AS OF EARLY THIS AFTERNOON AND WILL CONTINUE TO PUSH SOUTHWARD THIS EVENING. COLD HIGH PRESSURE SHOULD BUILD IN BEHIND THE FRONT FOR TONIGHT. WE EXPECT LOWS TO RANGE FROM THE UPPER TEENS NORTH TO THE LOWER 20S SOUTH. TUESDAY SHOULD BE COLDER THAN TODAY...WITH ONLY POOR TO FAIR MIXING. NORTHEAST WINDS EARLY TURNING TO THE EAST OR SOUTHEAST DURING THE DAY...AND HIGHS SHOULD TOP OUT MAINLY IN THE 30S. AS LOW LEVEL SOUTHERLY FLOW STRENGTHENS...WE WILL HAVE TO MONITOR FOR DEVELOPMENT OF LOW CLOUDS AND POSSIBLE DRIZZLE. THE BEST CHANCE FOR LIGHT RAIN STAYS TO OUR SOUTH IN KANSAS FOR WEDNESDAY/WEDNESDAY NIGHT...BUT AFTER COORDINATION WITH BORDERING OFFICES...ADDED SOME DRIZZLE INTO OUR SOUTHERN COUNTIES FOR WEDNESDAY. THIS COULD BE FREEZING DRIZZLE EARLY WEDNESDAY UNTIL TEMPERATURES RISE ABOVE 32 F. KEPT SOME MENTION OF DRIZZLE INTO WEDNESDAY NIGHT. BEST LIFT MOVES INTO SOUTHERN IOWA/NORTHERN MISSOURI FOR THURSDAY SO DID NOT INCLUDE MENTION OF DRIZZLE IN THAT PERIOD. HIGHS THURSDAY SHOULD REACH INTO THE 40S...POSSIBLY WARMER IF CLOUD COVER IS LESS THAN EXPECTED. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 320 PM CST MON DEC 8 2014 PATTERN IS A BIT MORE ACTIVE IN THIS PERIOD. 500 MB RIDGE WILL BE IN PLACE FROM NEW MEXICO ACROSS OUR AREA AND INTO ONTARIO AT 12Z FRIDAY ...WITH MODELS IN GOOD AGREEMENT WITH STRENGTH AND LOCATION OF A STRONG TROUGH ALONG THE WEST COAST. THE PATTERN OF LOW CLOUDS AND DRIZZLE MAY CONTINUE INTO FRIDAY. WENT SOMEWHAT CONSERVATIVE FOR HIGHS FRIDAY AND SATURDAY...MAINLY LOWER/MID 50S FRIDAY AND MID/ UPPER 50S SATURDAY. INCREASING SOUTHWEST FLOW WILL TRANSPORT MOISTURE AND EVEN SOME INSTABILITY INTO THE CENTRAL PLAINS FOR THE WEEKEND. HAVE SOME MENTION OF SHOWERS FOR AT LEAST PARTS OF THE AREA FROM SATURDAY INTO MONDAY...WITH HIGHEST CHANCES FOR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. ONE MAIN MID LEVEL LOW TRACKS ALONG THE CANADIAN BORDER WHILE THE OTHER MOVES EAST ACROSS NORTH TEXAS. THAT SHOULD KEEP THE HEAVIEST PCPN AMOUNTS OUT OF OUR AREA. && .AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 616 PM CST MON DEC 8 2014 VFR CONDITIONS ARE CURRENTLY IN PLACE...WITH A DECK OF MVFR STRATUS TO THE NORTHEAST OF THE TAF SITES. NOT TOO CONFIDENT REGARDING HOW FAR SOUTHWEST THE STRATUS WILL SPREAD...BUT KEPT TEMPO GROUP FOR KOFK/KOMA LATER THIS EVENING TO HINT AT THE POTENTIAL...WITH SCT MENTION THROUGH MORNING. OTHERWISE...NORTHWEST WINDS WILL BE ON THE GUSTY SIDE JUST BEHIND THE FRONT...THEN WEAKEN OVERNIGHT TO AROUND 8-10KT...AND SLACKEN FURTHER TO LIGHT/VARIABLE TOMORROW AS HIGH PRESSURE MOVES THROUGH. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1128 AM CST SUN DEC 7 2014 .UPDATE... ISSUED AT 1109 AM CST SUN DEC 7 2014 SENT ANOTHER UPDATE TO THE FORECAST THIS MORNING AS WITH CLOUDS AND AREAS OF FOG LINGERING A BIT LONGER THAN PREVIOUSLY EXPECTED...DO NOT THINK THAT THE FORECAST AMOUNT OF SUNSHINE WILL BE SUFFICIENT TO HELP TEMPERATURES CLIMB QUITE AS HIGH AS PREVIOUSLY FORECAST. AS A RESULT...ADJUSTED FORECAST MAX TEMPS DOWN A FEW DEGREES USING RAP GUIDANCE AS A REFERENCE...WITH NO ADDITIONAL CHANGES NECESSARY TO PREVIOUS FORECAST AT THIS TIME. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM CST SUN DEC 7 2014 FOCUS IS ON FOG...STRATUS...AND DRIZZLE INTO THE MORNING HOURS. AS EXPECTED STRATUS CONTINUES TO ADVECT TO THE NORTH AND WEST DURING THE PRE DAWN HOURS AS WE HAVE TRANSITIONED TO SOUTHERLY LLVL FLOW. TEMPS HAVE RISEN AS THE LOW CLOUD COVER HAS THICKENED AND FOR THE MOST PART TEMPS ARE RIGHT AROUND THE FREEZING MARK OR JUST A DEGREE OR TWO BELOW. TEMPERATURE AND DEWPOINT SPREADS HAVE CLOSED OR ARE WITHIN A DEGREE OF EACH OTHER AND WE HAVE SEEN VSBYS DROP ACROSS A GOOD PORTION OF OUR CWA ALREADY IN FOG AND BASED ON MODEL TRENDS THE STRATUS/FOG/VSBY RESTRICTIONS OF SOME DEGREE SHOULD ENCOMPASS OUR ENTIRE CWA BY DAYBREAK. VSBYS FOR THE MOST PART HAVE BEEN VARIABLE DUE TO STEADY SOUTHERLY WINDS AROUND 10 MPH. CURRENTLY HAVE A DENSE FOG ADVISORY IN EFFECT FOR OUR SE AREAS WHERE VSBYS WERE THE LOWEST INITIALLY...BUT DENSE FOG HAS YET TO MATERIALIZE ON A WIDESPREAD BASIS. DESPITE THIS...WITH TEMPS EITHER SIDE OF FREEZING...HAVE A HARD TIME GETTING RID OF THE HEADLINE AS FOG IS OUT THERE AND CANNOT RULE OUT MINIMAL ICING ON ELEVATED SFCS FOR A FEW MORE HOURS. ALOFT...A SHORTWAVE TROUGH WAS TRANSLATING FM THE HIGH PLAINS ACROSS THE CENTRAL PLAINS AND LIFT OVER THE LLVL MOISTURE COMBINED AND THE BOUNDARY LAYER MIXING MAY GENERATE DRIZZLE AND/OR FREEZING DRIZZLE BASED ON SFC TEMPS EITHER SIDE OF FREEZING. WE HAVE SEEN SOME LIGHT RADAR RETURNS BUT NO REPORTS OF PCPN ON OBS AND MODELS HAVE TRENDED DOWN FOR RECEIVING MEASURABLE PCPN AS THE SYSTEM MOVES THROUGH. BASED ON CURRENT CONDITIONS AND LATEST MODELS...EXPECT DRIZZLE IF ANYTHING VS RAIN...WITH LITTLE IF ANY ACCUMULATION. THE MID LEVEL TROUGH AXIS PASSES EAST OF OUR WESTERN ZONES BY MID MORNING AND AROUND MID DAY FOR OUR EASTERN ZONES AND ANY LIGHT DRIZZLE WILL COME TO AN END AND VSBYS WILL IMPROVE AS THIS SYSTEM EXITS THE AREA. A NORTHERN PLAINS TROUGH AND ASSOCIATED COLD FRONT WILL FINALLY SCOUR THE LOW CLOUDS/LLVL MOISTURE TO THE EAST BY THE EVENING. TEMPS LOOK TO STRUGGLE DUE TO THE LINGERING LOW CLOUDS FOR A GOOD PORTION OF THE DAY AND HAVE BACKED OFF ON HIGHS A FEW DEGREES. NOT A WHOLE LOT TO SAY ABOUT TONIGHT WITH DRY CONDITIONS FORECAST FOR OUR REGION WHILE AN UPPER WAVE MOVES INTO THE UPPER MIDWEST/GREAT LAKES AREA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 308 AM CST SUN DEC 7 2014 A SURFACE HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION MONDAY AND MONDAY NIGHT. THIS WILL BRING PARTLY CLOUDY SKIES...LIGHT WINDS AND MILD DAY TIME TEMPERATURES WITH A COOL NIGHT. AS THE HIGH MOVES TO THE EAST TUESDAY...WINDS WILL TURN TO THE SOUTH AND MOISTURE INCREASES ACROSS THE AREA. AT THE SAME TIME A WEAK UPPER LEVEL WAVE WILL MOVE INTO THE AREA. TUESDAY WILL BE A LITTLE COOLER BUT STILL ABOVE NORMAL. TUESDAY NIGHT THE UPPER WAVE MOVES THROUGH AND THE MOISTURE SPREADS ACROSS THE FORECAST AREA. CLOUDS WILL INCREASE DURING THE NIGHT. THE CLOUDS ARE EXPECTED TO LINGER INTO WEDNESDAY BEFORE GRADUALLY MOVING OUT. THE CLOUDS WILL KEEP TEMPERATURES FROM WARMING AS MUCH. WEDNESDAY NIGHT THE CLOUDS WILL CONTINUE TO DIMINISH. THURSDAY THROUGH FRIDAY AN UPPER LEVEL RIDGE BUILDS INTO THE AREA. THIS WILL ALLOW FOR SOME WARM ADVECTION AND WARMER TEMPERATURES AGAIN. BY SATURDAY ANOTHER UPPER LEVEL TROUGH WILL MOVE INTO THE ROCKIES. A SURFACE LOW DEVELOPS ON THE HIGH PLAINS AND WINDS TURN TO THE SOUTH AND INCREASE. MOISTURE ONCE AGAIN RETURNS TO THE AREA AND CLOUDS INCREASE. TEMPERATURES REMAIN MILD. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1109 AM CST SUN DEC 7 2014 IMPROVING CIGS AND VSBYS ARE EXPECTED AT BOTH TERMINALS OVER THE NEXT FEW HOURS AS A PASSING DISTURBANCE HELPS TO SCOUR OUT THE LOW LEVEL CLOUD DECK. WHILE CONDITIONS WILL IMPROVE EARLY THIS AFTERNOON...DO NOT EXPECT A RETURN TO PREVAILING VFR CONDITIONS UNTIL ABOUT 07/21Z...WITH LIGHT NORTH WESTERLY WINDS AND MOSTLY CLEAR SKIES RETURNING THIS EVENING AND THEN PERSISTING THROUGH MONDAY AFTERNOON AS A RIDGE OF HIGH PRESSURE TRANSITIONS ACROSS THE CENTRAL PLAINS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...ROSSI SHORT TERM...FAY LONG TERM...JCB AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1001 PM CST MON DEC 8 2014 .UPDATE... ISSUED AT 1000 PM CST MON DEC 8 2014 LOW LEVEL TRAJECTORY IS FROM THE NORTH/NORTHEAST. FOG LOOP INDICATED CLOUDS OVER SOUTHERN ONTARIO CONTINUE TO ADVECT TO THE SOUTHWEST. WILL HAVE TO RAISE TEMPS OVER THE MN SIDE WITH MORE CLOUDS FOR THE REST OF THE NIGHT AND DECREASE OVER PARTS OF EASTERN ND. UPDATE ISSUED AT 700 PM CST MON DEC 8 2014 SURFACE HIGH PRESSURE WAS LOCATED OVER THE CENTRAL DAKOTAS. WINDS WERE DROPPING OFF OVER EASTERN NORTH DAKOTA WITH LOSS OF INSOLATION. EXPECT TEMPS IN THE NORTHWEST ZONES TO DROP OFF QUICKLY THIS EVENING WITH NO CLOUD COVER. HOURLY TEMPS TWEAKED THIS EVENING WITH CLEARING MOVING IN FROM THE NORTHWEST. LOW TEMPS DECREASED A BIT WITH CLEARING IN THE NORTH. WILL UPDATE LOW TEMP ON NEXT UPDATE. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 335 PM CST MON DEC 8 2014 CLOUD COVER TRENDS AND IF WE GET ANY FOG DEVELOPMENT TONIGHT ARE THE MAIN FORECAST CONCERNS. NORTHWESTERLY FLOW ALOFT CONTINUES AS THE UPPER TROUGH DIGS INTO THE GREAT LAKES. THE SFC LOW HAS BEEN MOVING OFF OF THE ARROWHEAD OF MN AND WILL CONTINUE TO HEAD EAST...ALLOWING HIGH PRESSURE TO BUILD IN FROM ONTARIO INTO THE NORTHERN PLAINS TONIGHT. SOME BREAKS IN THE CLOUDS HAVE STARTED IN THE NORTHERN AND WESTERN CWA...WHICH THE RAP HAS A DECENT HANDLE ON. CLOUDS SHOULD GRADUALLY CLEAR FROM NORTH TO SOUTH THIS EVENING...AND WE SHOULD BE FAIRLY CLEAR BY MORNING. TEMPS WILL DROP INTO THE SINGLE DIGITS...AND WINDS SHOULD BECOME FAIRLY LIGHT AS THE CENTER OF THE HIGH MOVES OVER THE AREA. THE RAP AND HRRR HAVE SIGNS OF SOME PATCHY FOG FORMATION...BUT ALONG WITH THE LIGHT WINDS AND CLEAR SKIES WILL BE DRIER AIR AT THE SFC. THINK THAT CHANCES WILL NOT BE HIGH ENOUGH FOR FOG TO INCLUDE IN THE GRIDS AT THIS POINT...BUT WILL KEEP AN EYE ON IT. TOMORROW...AN EMBEDDED SHORTWAVE WILL MOVE INTO SD...BUT THE COLUMN WILL BE TOO DRY TO DO MUCH AND NONE OF THE MODELS ARE PRODUCING ANY PRECIP. THE SFC HIGH WILL BEGIN TO MOVE OFF TO THE EAST...AND RETURN FLOW WILL SET UP BY MORNING AND CONTINUE THROUGHOUT THE DAY ON TUESDAY. WITH A COLD START AND 850MB TEMPS STILL CLOSE TO ZERO EARLY IN THE DAY...TEMPS WILL STAY IN THE 20S EVEN WITH WARM AIR ADVECTION. THE SOUTH WINDS AND WARM ADVECTION WILL CONTINUE INTO TUESDAY NIGHT AS UPPER RIDGING BUILDS INTO THE REGION. THERE SHOULD BE ENOUGH MIXING TO KEEP LOWS IN THE TEENS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 335 PM CST MON DEC 8 2014 WEDNESDAY THROUGH THURSDAY...UPPER RIDGING WILL CONTINUE TO BUILD ACROSS THE NORTHERN PLAINS. SOUTHERN WINDS WILL CONTINUE AS THE SFC TROUGH REMAINS TO OUR NORTHWEST...BRINGING 850MB TEMPS BACK UP WELL ABOVE ZERO AND SOME CLOSE TO 10 C. THE SPOILER MAY BE IF WE GET STRATUS COMING BACK UP AND REMAINING OVER THE REGION. THE NAM WAS EVEN TRYING TO PUT SOME VERY LIGHT PRECIP OUT THURSDAY OVER THE EASTERN COUNTIES. WILL LEAVE ANY DRIZZLE MENTION OUT FOR NOW BUT BUMPED UP CLOUDS A BIT IN THE FAR EAST. HIGHS SHOULD SLOWLY BECOME WARMER THROUGH WEDNESDAY AND THURSDAY...REACHING BACK TOWARDS THE 30 MARK AND THEN INTO THE MID AND UPPER 30S ON THURSDAY. THURSDAY NIGHT TO MONDAY...MODELS CONTINUE TO AGREE ON 500MB RIDGING ACROSS THE NORTHERN PLAINS FOR THE END OF THE WEEK. NAEFS SHOWS 850MB TEMPS RANGING FROM 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL STARTING EARLY FRIDAY THROUGH LATE SATURDAY...AS 850MB TEMPS REACH TO 12C TO 16C FRIDAY NIGHT. MODELS INDICATE WINDS FROM THE SOUTH INSTEAD OF THE SFC WARMING SW OR WEST PLUS THE POTENTIAL FOR LOW STRATUS LAYER ADVECTING NORTH KEEPING TEMPS COOLER SATURDAY. FOR NOW WILL CONTINUE WITH A BLEND AS CLOUDS WILL MAKE OR BREAK TEMPS...EVEN WITH LOW SUN ANGLE. UPR 30S TO 40 WITH CLOUDS...WITHOUT MID TO UPR 40S POSSIBLE FRIDAY AND SATURDAY. FROPA SUNDAY WILL BRING LIGHT PCPN CHC TO THE FA AND BRING TEMPS DOWN TO NEAR NORMAL WITH HIGHS IN THE LOW 20S BY MONDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 700 PM CST MON DEC 8 2014 MVFR CIGS BETWEEN 10 AND 18 HUNDRED FT WERE ACROSS MUCH OF THE FORECAST AREA. FOG LOOP/SURFACE OBS INDICATE CLEARING OVER PARTS OF THE NORTHWEST ZONES. TRAILING EDGE OF CLOUD DECK WAS MOVING SOUTH/SOUTHEAST AT 25 TO 30 KNOTS. EXPECT CLEARING TO CONTINUE MOVING SOUTH OVERNIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...HOPPES SHORT TERM...JR LONG TERM...JR/JK AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
702 PM CST MON DEC 8 2014 .UPDATE... ISSUED AT 700 PM CST MON DEC 8 2014 SURFACE HIGH PRESSURE WAS LOCATED OVER THE CENTRAL DAKOTAS. WINDS WERE DROPPING OFF OVER EASTERN NORTH DAKOTA WITH LOSS OF INSOLATION. EXPECT TEMPS IN THE NORTHWEST ZONES TO DROP OFF QUICKLY THIS EVENING WITH NO CLOUD COVER. HOURLY TEMPS TWEAKED THIS EVENING WITH CLEARING MOVING IN FROM THE NORTHWEST. LOW TEMPS DECREASED A BIT WITH CLEARING IN THE NORTH. WILL UPDATE LOW TEMP ON NEXT UPDATE. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 335 PM CST MON DEC 8 2014 CLOUD COVER TRENDS AND IF WE GET ANY FOG DEVELOPMENT TONIGHT ARE THE MAIN FORECAST CONCERNS. NORTHWESTERLY FLOW ALOFT CONTINUES AS THE UPPER TROUGH DIGS INTO THE GREAT LAKES. THE SFC LOW HAS BEEN MOVING OFF OF THE ARROWHEAD OF MN AND WILL CONTINUE TO HEAD EAST...ALLOWING HIGH PRESSURE TO BUILD IN FROM ONTARIO INTO THE NORTHERN PLAINS TONIGHT. SOME BREAKS IN THE CLOUDS HAVE STARTED IN THE NORTHERN AND WESTERN CWA...WHICH THE RAP HAS A DECENT HANDLE ON. CLOUDS SHOULD GRADUALLY CLEAR FROM NORTH TO SOUTH THIS EVENING...AND WE SHOULD BE FAIRLY CLEAR BY MORNING. TEMPS WILL DROP INTO THE SINGLE DIGITS...AND WINDS SHOULD BECOME FAIRLY LIGHT AS THE CENTER OF THE HIGH MOVES OVER THE AREA. THE RAP AND HRRR HAVE SIGNS OF SOME PATCHY FOG FORMATION...BUT ALONG WITH THE LIGHT WINDS AND CLEAR SKIES WILL BE DRIER AIR AT THE SFC. THINK THAT CHANCES WILL NOT BE HIGH ENOUGH FOR FOG TO INCLUDE IN THE GRIDS AT THIS POINT...BUT WILL KEEP AN EYE ON IT. TOMORROW...AN EMBEDDED SHORTWAVE WILL MOVE INTO SD...BUT THE COLUMN WILL BE TOO DRY TO DO MUCH AND NONE OF THE MODELS ARE PRODUCING ANY PRECIP. THE SFC HIGH WILL BEGIN TO MOVE OFF TO THE EAST...AND RETURN FLOW WILL SET UP BY MORNING AND CONTINUE THROUGHOUT THE DAY ON TUESDAY. WITH A COLD START AND 850MB TEMPS STILL CLOSE TO ZERO EARLY IN THE DAY...TEMPS WILL STAY IN THE 20S EVEN WITH WARM AIR ADVECTION. THE SOUTH WINDS AND WARM ADVECTION WILL CONTINUE INTO TUESDAY NIGHT AS UPPER RIDGING BUILDS INTO THE REGION. THERE SHOULD BE ENOUGH MIXING TO KEEP LOWS IN THE TEENS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 335 PM CST MON DEC 8 2014 WEDNESDAY THROUGH THURSDAY...UPPER RIDGING WILL CONTINUE TO BUILD ACROSS THE NORTHERN PLAINS. SOUTHERN WINDS WILL CONTINUE AS THE SFC TROUGH REMAINS TO OUR NORTHWEST...BRINGING 850MB TEMPS BACK UP WELL ABOVE ZERO AND SOME CLOSE TO 10 C. THE SPOILER MAY BE IF WE GET STRATUS COMING BACK UP AND REMAINING OVER THE REGION. THE NAM WAS EVEN TRYING TO PUT SOME VERY LIGHT PRECIP OUT THURSDAY OVER THE EASTERN COUNTIES. WILL LEAVE ANY DRIZZLE MENTION OUT FOR NOW BUT BUMPED UP CLOUDS A BIT IN THE FAR EAST. HIGHS SHOULD SLOWLY BECOME WARMER THROUGH WEDNESDAY AND THURSDAY...REACHING BACK TOWARDS THE 30 MARK AND THEN INTO THE MID AND UPPER 30S ON THURSDAY. THURSDAY NIGHT TO MONDAY...MODELS CONTINUE TO AGREE ON 500MB RIDGING ACROSS THE NORTHERN PLAINS FOR THE END OF THE WEEK. NAEFS SHOWS 850MB TEMPS RANGING FROM 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL STARTING EARLY FRIDAY THROUGH LATE SATURDAY...AS 850MB TEMPS REACH TO 12C TO 16C FRIDAY NIGHT. MODELS INDICATE WINDS FROM THE SOUTH INSTEAD OF THE SFC WARMING SW OR WEST PLUS THE POTENTIAL FOR LOW STRATUS LAYER ADVECTING NORTH KEEPING TEMPS COOLER SATURDAY. FOR NOW WILL CONTINUE WITH A BLEND AS CLOUDS WILL MAKE OR BREAK TEMPS...EVEN WITH LOW SUN ANGLE. UPR 30S TO 40 WITH CLOUDS...WITHOUT MID TO UPR 40S POSSIBLE FRIDAY AND SATURDAY. FROPA SUNDAY WILL BRING LIGHT PCPN CHC TO THE FA AND BRING TEMPS DOWN TO NEAR NORMAL WITH HIGHS IN THE LOW 20S BY MONDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 700 PM CST MON DEC 8 2014 MVFR CIGS BETWEEN 10 AND 18 HUNDRED FT WERE ACROSS MUCH OF THE FORECAST AREA. FOG LOOP/SURFACE OBS INDICATE CLEARING OVER PARTS OF THE NORTHWEST ZONES. TRAILING EDGE OF CLOUD DECK WAS MOVING SOUTH/SOUTHEAST AT 25 TO 30 KNOTS. EXPECT CLEARING TO CONTINUE MOVING SOUTH OVERNIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...HOPPES SHORT TERM...JR LONG TERM...JR/JK AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1237 AM CST SUN DEC 7 2014 .UPDATE... ISSUED AT 1236 AM CST SUN DEC 7 2014 MAIN CHANGE FOR THIS UPDATE WAS TO FINE TUNE THE LATE NIGHT/EARLY MORNING PRECIP FORECAST. A LIGHT BAND OF FREEZING RAIN CONTINUES TO TRACK EASTWARD ACROSS MONTANA. GLASGOW MONTANA PICKED UP AROUND 0.01 INCHES OF FREEZING RAIN AND REPORTED SLICK CONDITIONS. WHILE THIS BAND IS RATHER SMALL AND PRODUCING VERY MINIMAL AMOUNTS...EVEN A LITTLE BIT OF ICE CAN CAUSE PROBLEMS. LATEST RADAR TRENDS CONTINUE TO INDICATE THAT THIS BAND OF FREEZING RAIN WILL MAKE IT INTO WESTERN NORTH DAKOTA WITHIN THE NEXT HOUR. SHORT-TERM...HIGH RES MODELS HAVE A POOR HANDLE ON THIS BAND...SO CONFIDENCE IN THE EVOLUTION OF THE SHORT-TERM FORECAST IS RATHER LOW. THIS BAND OF PRECIP IS VERY LIGHT AND NARROW AND COULD DISSIPATE AT ANY TIME AS THE MAIN LOW PRESSURE CENTER IS STILL OUT IN CENTRAL MONTANA. BUT... FELT IT BETTER TO BE SAFE THAN SORRY...SO KEPT THE SPECIAL WEATHER STATEMENT GOING AND THE MENTION OF FREEZING RAIN IN THE FORECAST THROUGH THE EARLY MORNING HOURS. UPDATE ISSUED AT 905 PM CST SAT DEC 6 2014 LATEST REGIONAL RADAR IMAGERY SHOWS BAND OF LIGHT RAIN WORKING ITS WAY FROM CENTRAL INTO EASTERN MONTANA. LATEST HIGH-RES GUIDANCE CONTINUES TO HAVE A GOOD GRASP ON THE PRECIPITATION BEING PRESENT...BUT OVER THE PAST FEW RUNS HAS HELD IT TOO FAR NORTH. WITH THIS...HAVE SPREAD PRECIP CHANCES FURTHER SOUTH A BIT AND HAVE INCREASED POPS SOME OVER MUCH OF FAR WESTERN NORTH DAKOTA AS MODELS CONTINUE TO HOLD THIS TOGETHER AS IT PUSHES EAST. BY THE TIME IT REACHES OUR AREA...IT SHOULD BE MAINLY LIGHT FREEZING RAIN WITH THE COOLER SURFACE TEMPS. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 620 PM CST SAT DEC 6 2014 SOME LIGHT RADAR RETURNS SHOWING UP OVER CENTRAL MONTANA WITH LIGHT RAIN BEING REPORTED IN LEWISTOWN. WILL WATCH HOW THIS EVOLVES THROUGH THE EVENING AS IT PUSHES EAST AS HIGH-RES MODELS CONTINUE TO BRING SOME OF THIS PRECIPITATION INTO WESTERN NORTH DAKOTA AFTER MIDNIGHT. FORECAST SOUNDINGS STILL SUGGEST THAT IF ANY PRECIPITATION DOES DEVELOP IT WILL BE FREEZING RAIN. CURRENT FORECAST REFLECTS THIS WELL. ONLY CHANGE THAT WAS MADE FOR EARLY EVENING UPDATE WAS TO INCREASE CLOUD COVER TO ACCOUNT FOR HIGH CLOUDS COVERING MUCH OF THE AREA. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 333 PM CST SAT DEC 6 2014 THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE POSSIBLE FREEZING PRECIPITATION TONIGHT AND SUNDAY. CURRENTLY A SHORTWAVE TROUGH IS LOCATED OVER EASTERN WASHINGTON. THE WAVE WILL TRACK ALONG THE INTERNATIONAL BORDER OVERNIGHT AND DEVELOP A SURFACE LOW IN THE LEE OF THE ROCKIES. THE SURFACE/UPPER LEVEL LOW IS PROGGED TO BE OVER NORTHEAST MT/SOUTH CENTRAL SK BY 12 UTC SUNDAY. WARM ADVECTION AHEAD OF THE LOW WILL RESULT IN WARM TEMPERATURES ALOFT ENCOMPASSING ALL OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT. THUS THE POTENTIAL FOR FREEZING PRECIPITATION THROUGH SUNDAY AFTERNOON. THE LATEST 20 UTC RAP DEPICTS A BAND OF LIGHT REFLECTIVITIES MOVING INTO WESTERN NORTH DAKOTA AROUND 08 UTC SUNDAY. HOWEVER...ANY MEASURABLE PRECIPITATION REMAINS CONFINED TO THE FAR NORTHWEST CORNER OF NORTH DAKOTA. THE RAP MAINTAINS THE LIGHT REFLECTIVITIES AS THEY CROSS THE CWA BUT KEEPS MAINLY TRACE AMOUNTS...AND MAINLY CONFINED TO THE FAR NORTHERN TIER COUNTIES. THE GFS/EC/GEM ALL BRING VERY LIGHT QPF INTO THE FAR NORTHWEST THROUGH 12 UTC. THE EC/GEM ALSO TRACK SOME TRACE AMOUNTS ALONG THE NORTHERN TIER COUNTIES THROUGH THE MORNING. THE GFS IS FARTHER SOUTH AND IS ON THE SOUTHERN SIDE OF THE ENVELOPE OF DETERMINISTIC SOLUTIONS. THUS HAVE KEPT BEST CHANCE FOR QPF IN THE FAR NORTHWEST 06-12 UTC SUNDAY AND ACROSS THE FAR NORTHERN TIER COUNTIES 12-18 UTC SUNDAY. WILL STILL HAVE A MENTION OF SOME FREEZING RAIN SOUTHWEST AND SOUTH CENTRAL (MAINLY ALONG AND NORTH OF I-94) BUT WITH NO SIGNIFICANT ACCUMULATIONS. EVEN ACROSS THE NORTH...DETERMINISTIC MODEL QPF REMAINS AT OR BELOW A HUNDREDTH OF AN INCH. ONLY A LITTLE FREEZING RAIN CAN CAUSE SIGNIFICANT TRAVEL ISSUES. BUT WITH LOW MODEL QPF...WILL HOLD OFF ON ANY HIGHLIGHTS AT THIS TIME. WE WILL STILL HAVE TIME TO WATCH THINGS DEVELOP ACROSS NORTHEAST MONTANA AND SOUTHERN SASKATCHEWAN THIS EVENING AND OVERNIGHT. COULD STILL SEE A VERY LIGHT MIX OVER THE NORTH CENTRAL MONDAY AFTERNOON. BUT WESTERN NORTH DAKOTA WILL BE ON THE BACK SIDE OF THE MID LEVEL TROUGH WITH COLD ADVECTION TRACKING SOUTHEAST ACROSS THE CWA DURING THE AFTERNOON. THUS THE WEST WILL QUICKLY TRANSITION TO SNOW AND THE SOUTH CENTRAL SHOULD WARM UP ENOUGH TO SEE ALL RAIN WITH A QUICK CHANGE TO SNOW AS THE COLD ADVECTION ARRIVES. IT WILL ALSO BECOME BREEZY TO WINDY SUNDAY AFTERNOON FROM WEST TO EAST BEHIND THE TRACK OF THE LOW. STRONGEST WINDS 20-30 MPH WITH GUSTS TO 35 MPH WILL SPREAD FROM THE SOUTHWEST SUNDAY AFTERNOON INTO THE CENTRAL LATE AFTERNOON TO EARLY EVENING. HIGHS SUNDAY WILL LIKELY BE REACHED IN THE MORNING NORTH TO EARLY AFTERNOON SOUTH WITH TEMPERATURES FALLING MID TO LATE AFTERNOON EVERYWHERE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 333 PM CST SAT DEC 6 2014 POST FRONTAL NORTHWEST WINDS OF 20 TO 30 MPH ALONG WITH ISOLATED TO SCATTERED SNOW SHOWERS WILL DOMINATE SUNDAY NIGHT. THE ENTIRE SYSTEM DEPARTS CENTRAL NORTH DAKOTA BY 12Z MONDAY WITH COLDER AIR REMAINING IN PLACE FOR THE MORNING FOLLOWED BY WARM AIR ADVECTION MONDAY AFTERNOON ESPECIALLY IN THE WEST. A PROGRESSIVE PATTERN CONTINUES WITH A TRANSITORY RIDGE SHIFTING THROUGH MONDAY NIGHT FOLLOWED BY A DRY SHORTWAVE TROUGH PASSING THROUGH TUESDAY. THEREAFTER...UPPER RIDGING DOMINATES AND SHIFTS EAST BY MIDWEEK ALLOWING A SOUTHWEST FLOW TO RETURN. HOWEVER NOTHING FORESEEN IN THE SOUTHWEST FLOW IN TERMS OF SIGNIFICANT SHORTWAVES AT LEAST THROUGH SATURDAY PER GFS/GEM GLOBAL/SUPERBLEND. HOWEVER THE LATEST ECMWF PUSHES A FAST MOVING SHORTWAVE AND CONSEQUENTLY LIGHT PRECIPITATION/FAVORING RAIN SHOWERS AT THIS POINT...ACROSS THE NORTH THURSDAY. HIGH TEMPERATURES WILL WARM TO BETWEEN 35F AND 45F WEDNESDAY THROUGH FRIDAY...THEN A BIT COOLER FOR SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1236 AM CST SUN DEC 7 2014 VFR CONDITIONS ARE EXPECTED THROUGH THE OVERNIGHT HOURS. -FZRA MAY MOVE INTO WESTERN NORTH DAKOTA AFTER 07Z AND PUSH EAST THROUGH THE MORNING HOURS. THE BEST CHANCE OF FREEZING RAIN IS AT KISN BETWEEN 08Z AND 09Z. LEFT OUT OTHER TERMINALS FOR NOW GIVEN THE LOW COVERAGE...BUT WILL MONITOR THROUGH THE EVENING. WINDS WILL SHIFT FROM THE WEST/NORTHWEST AND AREAS OF PRECIPITATION WILL DEVELOP...MAINLY OVER THE NORTHWEST LATER THIS MORNING. -RA/-FZRA WILL BE POSSIBLE....WITH A TRANSITION TOWARDS -SN AS COOLER AIR MOVES IN FROM NORTHWEST TO SOUTHEAST. CIGS WILL DIMINISH TO MVFR LEVELS FROM NORTHWEST TO SOUTHEAST STARTING LATE MORNING AND CONTINUING THROUGH THE AFTERNOON. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...TWH LONG TERM...KS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
947 PM EST MON DEC 8 2014 .SYNOPSIS... A WEAKENING LOW NEAR LAKE SUPERIOR WILL DROP SOUTHEAST THROUGH THE AREA TONIGHT TO MERGE WITH A LOW NEAR THE VIRGINIA COAST TUESDAY MORNING THAT WILL STALL NEAR BOSTON THROUGH THURSDAY. HIGH PRESSURE OVER THE UPPER MIDWEST WEDNESDAY WILL EVENTUALLY SPREAD UP THE OHIO VALLEY BY THE WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... LATEST HRRR MODEL RIGHT ON TARGET WITH PRECIPITATION EXPANDING NORTH INTO THE CENTRAL PORTIONS OF THE FORECAST AREA. MADE SOME ADJUSTMENTS TO PRECIPITATION TO ACCOUNT FOR THIS ACTIVITY. COLDER AIR PUSHING EAST WITH THE COLD FRONT OVERNIGHT AND WILL CHANGE PRECIPITATION OVER TO SNOW FROM WEST TO EAST. TEMPERATURES STILL LOOK REASONABLE AS DEW POINTS ARE CURRENTLY IN THE MIDDLE THIRTIES BEHIND THE WEAK WARM FRONT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... THE SITUATION ON TUE LOOKS SIMILAR TO THE LATTER PART OF TONIGHT WITH TEMPS NOT QUITE COLD ENOUGH TO SUPPORT JUST SNOW. CAN SEE THE PRECIP WAVERING BACK AND FORTH ON TUE. BESIDES...THE PRECIP WILL BE LIGHT SO THINK SNOW ACCUMULATION WILL STAY UNDER A HALF AN INCH. BY TUE NIGHT...THE BETTER ENERGY AND DEEPER MOISTURE WILL BE SHIFTING EAST TOWARD THE EAST COAST SYSTEM. TEMPS SHOULD BE GETTING COLD ENOUGH FOR JUST SNOW BUT THE THREAT SHOULD BE SHIFTING INTO MAINLY JUST THE SNOWBELT. TEMPS ALOFT ONLY GET COLD ENOUGH FOR A LITTLE LAKE ENHANCEMENT. SNOW ACCUMULATION WILL MAINLY BE IN THE SNOWBELT AND NEARBY AREAS WITH MAX AMOUNTS OF ABOUT 2 TO MAYBE 3 INCHES LOOKING POSSIBLE IN THE FAVORED AREAS OF THE SNOWBELT IN NW PA. THE WEATHER PATTERN WILL REMAIN NEARLY STALLED INTO THU SO NOT A LOT WILL CHANGE THRU THEN. A GOOD CHANCE FOR LAKE ENHANCED SNOW SHOWERS WILL PREVAIL THRU THU WITH ACCUMULATION AMOUNTS GENERALLY STAYING ON THE LIGHTER SIDE WITH ABOUT 1 TO 3 INCHES POSSIBLE IN ANY GIVEN 12 HOUR PERIOD IN THE SNOWBELT WITH DUSTINGS OF ACCUMULATION POSSIBLE IN NEARBY AREAS. TEMPS WILL STAY ABOUT 5 DEGREE BELOW NORMAL THRU THE PERIOD. && .LONG TERM /FRIDAY THROUGH MONDAY/... GENERALLY DRY WITH A WARMING TREND FOR THIS PERIOD. THE SURFACE RIDGE AND UPPER RIDGE WILL BE BUILDING IN ACROSS THE AREA STARTING FRIDAY AND IT WILL MOVE EAST OF THE AREA BY MONDAY. ON FRIDAY A WEAK SURFACE TROF WILL BRUSH THE EASTERN PORTION OF THE FORECAST AREA. KEPT SLIGHT CHANCE POPS WITH A THREAT OF FLURRIES AND POSSIBLY SPRINKLES IN THE AFTERNOON EAST OF CLEVELAND. THE 12Z ECMWF IS A LITTLE MORE PESSIMISTIC IN CONTINUING SOME QPF ON FRIDAY AS IT IS A LITTLE SLOWER IN MOVING IN THE RIDGE. AT THIS TIME LEANING MAINLY DRY. THE ECMWF MODEL WAS TRYING TO HINT AT SOME QPF OVER THE WEEKEND. THIS DOES NOT SEEM REASONABLE BASED ON THE DRY AIR...RIDGING AND NO OMEGA. THE GFS AND CANADIAN MODEL KEEPS IT DRY...SO WENT THAT DIRECTION. WENT CLOSE TO WPC GUIDANCE FOR THE TEMPERATURES. TEMPERATURES WILL BECOME ABOVE NORMAL BY SUNDAY. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... MIDDLE AND HIGH LEVEL CLOUD COVER WILL CONTINUE TO LOWER AS A COLD FRONT SLOWLY MOVES EASTWARD INTO TUESDAY MORNING. THERE IS SOME VERY LIGHT RAIN/DRIZZLE NEAR AND IN THE WAKE OF THE COLD FRONT. MOST OF THIS WILL STRUGGLE TO SPREAD EASTWARD FROM NW OHIO SINCE THERE IS PLENTY OF LOW LEVEL DRY AIR TO HELP ERODE IT. THE REGION WILL THEN HAVE A PERIOD OF WEAK LIFT AS AN UPPER LEVEL TROUGH APPROACHES. THIS SHOULD CAUSE AREAS OF DRIZZLE AND IFR CONDITIONS TO DEVELOP AT MOST LOCATIONS. THE KERI AREA WILL LIKELY BE THE LATEST GETTING THE IFR CONDITIONS SINCE THERE WILL BE A DECENT DOWN SLOPING COMPONENT THROUGH THE NIGHT. A SECONDARY SURGE OF COOLER AIR WILL ARRIVE BY EARLY TUESDAY AFTERNOON AS THE UPPER LEVEL TROUGH PASSES. WINDS WILL SHIFT AROUND TO THE NORTH AS IT PASSES. SOME LIGHT RAIN MAY DEVELOP WITH THE UPPER LEVEL TROUGH. TIMING AND INTENSITY IS UNCERTAIN SO ONLY PLACED A VICINITY SHOWER IN THE TAFS AT THIS POINT. WILL HAVE TO MONITOR FOR A CHANGE TO SNOW BY TUESDAY EVENING...ESPECIALLY NE OHIO INTO NW PA. .OUTLOOK...NON VFR MAINLY IN NE OHIO AND NW PA TUESDAY NIGHT INTO THUR WITH LINGERING SNOW SHOWERS. && .MARINE... .SYNOPSIS... A WEAKENING LOW NEAR LAKE SUPERIOR WILL DROP SOUTHEAST THROUGH THE AREA TONIGHT TO MERGE WITH A LOW NEAR THE VIRGINIA COAST TUESDAY MORNING THAT WILL STALL NEAR BOSTON THROUGH THURSDAY. HIGH PRESSURE OVER THE UPPER MIDWEST WEDNESDAY WILL EVENTUALLY SPREAD UP THE OHIO VALLEY BY THE WEEKEND. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...ADAMS NEAR TERM...LOMBARDY SHORT TERM...ADAMS LONG TERM...KIELTYKA AVIATION...MULLEN MARINE...MAYERS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1233 AM EST SUN DEC 7 2014 .SYNOPSIS... LOW PRESSURE WAVE PASSES WITH COLDER AIR IN ITS WAKE TONIGHT. HIGH PRESSURE SUNDAY. UPPER TROUGH MONDAY NIGHT/TUESDAY. COLDER AIR TUESDAY NIGHT INTO WEDNESDAY. && .NEAR TERM /THROUGH TODAY/... 10 PM UPDATE. NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION... AS OF 18Z THE FRONT HAS CLEARED CRW AND CKB WITH SURFACE LOW E OF EKN. FRONT WILL CLEAR THE MOUNTAINS BY 21Z. AS THE FRONT CROSSES...TEMPERATURE FALLS OF 7 TO 10 DEGREES CAN BE EXPECTED WITH GRADUALLY LOWERING TEMPS THEREAFTER THROUGH THE EVENING. LOW CIGS AND VSBY IN POST FRONTAL DZ CAN BE EXPECTED THRU THE REMAINDER OF THE AFTERNOON...ALONG WITH GUSTY NW WINDS. WILL WATCH -RA TO FILL BACK IN LATER THIS AFTERNOON AS THE UPPER LEVEL TROF CROSSES. AREA WILL BEGIN TO DRY OUT WITH PASSAGE OF THE UPPER LEVEL TROF...SAVE FOR SOME DZ HANGING ON ACROSS THE MOUNTAINS THIS EVENING. ELECTED TO KEEP POSSIBILITY OF IT ENDING AS A LITTLE FRZ DZ BUT NOT EXPECTING ANY IMPACTS. WHAT WILL NOT CLEAR OUT THIS EVENING IS THE LOW STRATUS. HOWEVER...DO EXPECT BASES TO LIFT A BIT TONIGHT. THINK SE OH WILL SCT OUT DURING THE PREDAWN. HOWEVER...DEVELOPING SUBSIDENCE INVERSION BENEATH THIS LINGERING MOISTURE WILL MAKE IT VERY DIFFICULT FOR STRATUS TO BREAK UP E OF THE OH RIVER OVERNIGHT. WITH WEAK CAA BENEATH THE INVERSION AND LOW LEVEL WINDS BECOMING MORE NE...FELT IT NECESSARY TO HOLD THE STRATUS IN ALONG THE CLIMATOLOGICAL FAVORED AREAS IN THIS SETUP....IE THE C LOWLANDS AND COAL FIELDS THRU THE MORNING HOURS. CLOUDS WILL GRADUALLY SCT OUT FROM NE TO SW...WITH AREAS ALONG AND S OF I64 CORRIDOR THE LAST TO LOSE THE STRATUS...POSSIBLY HOLDING ON UNTIL LATE AFTERNOON. FOR TEMPS...USED A BLEND OF LAMP AND HRRR FOR TEMPS TONIGHT. FOR SUNDAY...USED MET AS A BASE WHICH BETTER REFLECTED EXPECTED COOLER READINGS ALONG AND ESPECIALLY S OF I64 CORRIDOR DUE TO CLOUDS. FURTHER N...FELT LOCAL MOS WAS THE WAY TO GO WHERE READINGS SHOULD REACH INTO THE MID OR UPPER 40S. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... STRONG MID LEVEL RIDGING AND HIGH PRESSURE INFLUENCES FROM EASTERN CANADA DOMINATE SUNDAY...BUT SUNSHINE STILL LIMITED TO THE MORNING HOURS WITH CIRRUS AHEAD OF THE UPPER LEVEL TROUGH DIGGING IN OVER THE WESTERN GREAT LAKES. MODELS NOW SETTLING ON THE TROUGH AXIS HOLDING THE DEVELOPING COASTAL SYSTEM OFFSHORE AND MAINLY AWAY FROM OUR EASTERN MOST RIDGES...BUT WILL STILL ENTERTAIN SOME LOW END POPS FOR THE FAR EASTERN PORTIONS OF RAND/POCA COUNTIES. SOME ICING IS POSSIBLE IN THE SOUTHEAST UPSLOPE AREAS. HAVE THE TRANSITION TO SNOW FOR THE LOWLAND UPSLOPE AREAS FROM RAIN TO SNOW A BIT SLOWER...AND JUST BEGINNING BY THE END OF THE SHORT TERM FORECAST AT 00Z WEDNESDAY. 925MB TEMPERATURES GO BELOW 0C JUST AFTER 21Z TUESDAY FOR THE MOUNTAINS...MAKING THE 18Z TO 00Z PERIOD THE RAIN/SNOW TRANSITION TIMES FOR THE MOUNTAINOUS AREAS. LOWLANDS WILL TRANSITION TO SNOW LIKELY IN THE BEGINNING FEW HOURS OF THE LONG TERM. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... USED A BLEND OF THE GFS...GEFS MEAN...ECMWF...ECMWF MEAN...AND CONTINUITY WITH THE PREVIOUS FORECAST. THIS WOULD HAVE WRAP AROUND MOISTURE OVER THE REGION FOR TUESDAY NIGHT INTO WEDNESDAY. 850 MB TEMPERATURES ARE MARGINAL FOR UPSLOPE SNOW...SO COULD SEE DRIZZLE INSTEAD OF SNOW IN MANY AREAS. A HIGH PRESSURE SYSTEM THEN MOVES IN FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...ALLOWING TEMPERATURES TO MODERATE SOME. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... MVFR CIGS STILL IN PLACE ACROSS MOST OF FORECAST AREA...WITH IFR AT BKW. EXPECT CONDITIONS TO STAY FAIRLY SIMILAR FOR THE NEXT SEVERAL HOURS BEFORE GRADUAL IMPROVEMENT BEGINS. AS DRY AIR MOVES IN FROM THE N...CLOUDS WILL SCATTER OUT LATER TODAY WITH VFR EXPECTED AT ALL TAF SITES BY MID TO LATE MORNING. CURRENT NORTHERLY WINDS WILL TURN MORE EASTERLY BY TONIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING OF IMPROVEMENTS MAY VARY. 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. DATE SUN 12/07/14 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H H H H H H H H H H M M HTS CONSISTENCY H H H H H H H M M M M M BKW CONSISTENCY H H H H H M H H M M M M EKN CONSISTENCY M H H H H H M M M M H H PKB CONSISTENCY H H H M M M M M M M M M CKB CONSISTENCY H H H H H M M M M M M M AFTER 06Z MONDAY... IFR POSSIBLE IN RAIN/SNOW MONDAY NIGHT INTO WEDNESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...RPY/JMV/30/26 NEAR TERM...JMV/30 SHORT TERM...26 LONG TERM...RPY AVIATION...MZ
AS MENTIONED IN THE AFTERNOON FORECAST DISCUSSION... WILL LIKELY
SEE AT LEAST PATCHY FOG DEVELOP TONIGHT... ESPECIALLY ACROSS THE
SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS. NAM MOS GUIDANCE... HRRR AND RAP SUGGEST THAT VISIBILITIES LESS THAN 1/2SM WILL BE POSSIBLE AT KSPS.. KLAW... KHBR AND PERHAPS NORTH UP TO KOUN... KOKC AND KCSM. AT THE MOMENT... HAVE JUST PUT A TEMPO GROUP TO 1SM OR 2SM AT SOME OF THE CENTRAL AND SOUTHERN SITES BUT WILL WATCH TRENDS FOR INDICATION OF HIGHER CHANCES OF THE DENSE FOG. && .PREV DISCUSSION... /ISSUED 358 PM CST MON DEC 8 2014/ DISCUSSION... ONLY A SMALL AREA OF STRATUS REMAIN THIS AFTERNOON NEAR AND SOUTH OF THE RED RIVER. EXPECT AT LEAST SOME PATCHY FOG TO DEVELOP SOUTH OF I40 TONIGHT UNDER THE INFLUENCE OF LIGHT WINDS AND MOSTLY CLEAR SKIES. AFTER SUNRISE TOMORROW...A COLD FRONT WILL MOVE INTO OK ALTHOUGH IT WILL FEEL WARMER THAN THE LAST FEW DAYS WITH CLEAR SKIES PRESENT. BY WED...SOUTH WINDS WILL RETURN BUT CLOUD COVER WILL BEGIN TO INCREASE FROM WEST TO EAST AS TWO MINOR SHORTWAVE TROUGH IMPACT THE REGION AND MOISTURE INCREASES. DRIZZLE APPEARS POSSIBLE ALONG A STATIONARY BOUNDARY NEAR THE KS/OK BORDER THURS AM...WITH PATCHY FOG AND A SCHC OF RAIN FOR MOST OTHER LOCATIONS. LOW LEVEL MOISTURE WILL INCREASE THURS WITH SOUTH WINDS PRESENT...AND CONTINUE THROUGH THIS WEEKEND. THIS WAA REGIME WILL LIKELY RESULT IN MORE STRATUS...FOG...AND DRIZZLE THROUGH SATURDAY. IT WILL ALSO RESULT IN A DIFFICULT TEMP FORECAST. FOR NOW...WILL KEEP LOWS A FEW DEGREES WARMER AND HIGHS A FEW DEGREES LOWER ANTICIPATING WIDESPREAD CLOUD COVER THROUGH THIS WEEKEND. HOWEVER...LOCATIONS OUT WEST COULD CLIMB UP INTO THE 70S SATURDAY OUTSIDE THE INFLUENCE OF THE CLOUDS/LIGHT RAIN/DRIZZLE WHERE 850MB TEMPS COULD REACH THE MID TEENS. RAIN CHANCES WILL INCREASE SIGNIFICANTLY LATE SAT THROUGH SUN AS A DEEP TROUGH APPROACHES THE SOUTHERN PLAINS. WILL INCLUDE A SMALL AREA OF LIKELY POPS WEST OF THE OKC METRO FOR NOW SUN...BUT GIVEN AGREEMENT AND CONSISTENCY BETWEEN MODELS THESE WILL LIKELY INCREASE OVER THE NEXT SEVERAL DAYS ESPECIALLY OVER THE CENTRAL AND EASTERN ZONES. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 38 57 37 56 / 0 0 0 10 HOBART OK 38 58 40 57 / 0 0 0 10 WICHITA FALLS TX 39 62 42 62 / 0 0 0 10 GAGE OK 34 58 39 57 / 0 0 0 10 PONCA CITY OK 34 50 31 50 / 0 0 0 20 DURANT OK 40 62 38 57 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1033 PM EST MON DEC 8 2014 .SYNOPSIS... LOW PRESSURE FORMING EAST OF THE CAROLINA COAST WILL MOVE UP THE EAST COAST AND BRING AN EXTENDED PERIOD OF WINTRY WEATHER TO THE REGION. BLUSTERY NORTHWEST FLOW WITH AREAS OF SNOW SHOWERS WILL FOLLOW THIS STORM FOR THE SECOND HALF OF THE WEEK. && .NEAR TERM /UNTIL MIDNIGHT TONIGHT/... PRECIP LIFTING NORTH INTO THE SC MTNS LATE THIS EVENING IN REGION OF LG SCALE FORCING AHEAD OF LEAD SHORTWAVE OVR THE S APPALACHIANS. SATL-DERIVED PWAT LOOP SHOWING DEEP LVL MOISTURE LIFTING NORTHWARD THRU THE MID ATLANTIC REGION ALONG AXIS OF EASTERLY LL JET. HAVE ACCELERATED THE ARRIVAL OF PRECIP BASED ON RADAR TRENDS AND ALSO HAVE TRENDED PTYPE TO MOSTLY SNOW ACROSS THE SPINE OF THE ALLEGHENIES BASED ON UPSTREAM REPORTS AND LATEST HRRR OUTPUT...WHICH SUGGESTS A STRIPE OF A COUPLE INCHES OF SNOW IS NOW POSSIBLE LATE TONIGHT FROM SOMERSET/BEDFORD CO NEWRD INTO THE CENTRAL MTNS. FURTHER EAST...STILL THINKING A PERIOD OF FZRA IS MOST LIKELY OVR THE SUSQ VALLEY EARLY TUE AM. BLEND OF 18Z CONSALL AND LATEST LAMP/HRRR OUTPUT SUGGEST TEMPS BY DAWN WILL RANGE FROM THE U20S OVR THE ALLEGHENY MTNS...TO PERHAPS JUST ABV FREEZING OVR LANCASTER CO. && .SHORT TERM /MIDNIGHT TONIGHT THROUGH TUESDAY NIGHT/... STILL A VERY UNCERTAIN FORECAST DESPITE HOW CLOSE WE ARE TO THE ONSET OF THINGS. A LOW DEVELOPING OFF THE CAROLINA COAST WILL MOVE DUE NORTH AND UP ALONG THE NJ COAST TUESDAY INTO WEDNESDAY. GIVEN THIS SLIGHTLY OFFSHORE TRACK...EASTERN PA WILL BEAR THE BRUNT OF THE STORM WITH THE POTENTIAL FOR HEAVY RAIN OVR SE PA...AND POSSIBLY SOME SIG SNOW OVER THE HIGHER ELEVATIONS OF TIOGA/SULLIVAN/SCHUYLKILL COUNTIES. WILL LIKELY BE ABLE TO CANCEL WINT WX ADVISORY BEFORE 18Z...AS NEARLY ALL GUIDANCE INDICATES TEMPS RISING WELL ABV FREEZING BY LATE AM. MAIN CONCERN WILL BE THE EARLY AM COMMUTE FOR A MIXTURE OF SNOW AND FRZA. MAIN FCST ISSUE REMAINS HOW FAR WEST SIG PRECIP CAN BE DRAGGED INTO CENTRAL PA. MODELS ARE CONSISTENT IN A PRETTY SHARP BACK EDGE CUTTING OFF MOST OF THE PRECIP SOMEWHERE BETWEEN STATE COLLEGE AND PERHAPS WILLIAMSPORT-HARRISBURG. WITH THE UNCERTAINTY STILL HIGH...WE KEPT THE WINTER STORM WATCH UP FOR OUR HIGHER ELEVATIONS FROM TIOGA SOUTH DOWN INTO SCHUYLKILL COUNTY...EMPHASIZING THE BEST CHANCE FOR HEAVY WET SNOW BEING OVER THOSE HIGHER ELEVATIONS. LATEST RAP...21Z SREF AND 00Z NAM ALL SUGGEST ENOUGH WARM AIR OVERSPREADS EASTERN PA TO TURN THE BULK OF THE PRECIP TO RAIN BTWN LATE AM AND TUE AFTN OVR OUR NE COUNTIES. HOWEVER...DEVELOPING DEFORMATION BAND ON THE NW PERIPHERY OF MID LVL LOW COULD STILL POTENTIALLY PRODUCE SIG SNOW TUE NIGHT FROM TIOGA CO SOUTH THRU SCHUYLKILL CO. THE LOW IS EXPECTED TO REACH THE NJ COAST AROUND MID DAY TUESDAY AND SLOW DOWN OR EVEN STALL FOR PERHAPS A DAY OR MORE AS THE UPPER LOW CAPTURES THE SYSTEM. WHILE MUCH OF OUR FORECAST AREA WILL LIKELY WARM ENOUGH TO MAKE FOR JUST PLAIN RAIN DURING THE DAY TUESDAY...THIS WILL EVENTUALLY CAUSE COLDER AIR TO COME IN AT ALL LEVELS AND CHANGE THE MIXED PRECIP BACK TO MAINLY SNOW TUESDAY NIGHT AND INTO WED. IT`S STILL UNCLEAR HOW MUCH PRECIP WILL RESULT AS THE MODELS DIFFER GREATLY ON THE DEVELOPMENT OF A POSSIBLE DEFORMATION ZONE. THE SOLUTIONS FALL BETWEEN THE ECMWF THAT TARGETS MY NWRN ZONES EVEN THROUGH WED INTO THURSDAY...TO THE GFS THAT SHOWS ALMOST NO PRECIP WRAPPING BACK. I KEPT A GOOD CHANCE OF MAINLY LIGHT QPF IN THE FORECAST THROUGH THURSDAY BEFORE TAPERING OFF THE ACTIVITY FOR THE REMAINDER OF THE WEEK. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WITH THE LOW MOVING VERY SLOWLY IF AT ALL...THE CHANCES FOR AT LEAST SOME LIGHT SNOW WILL REMAIN HIGH WEDNESDAY INTO THURSDAY. I GENERALLY KEPT AMOUNTS LOW...DEPENDENT ON THE FORMATION OF THE DEFORMATION ZONE MENTIONED EARLIER...OR NOT. BY THE END OF THE WEEK GUIDANCE IS IN DECENT AGREEMENT FOR THE UPPER LOW TO NUDGE EAST ENOUGH TO HAVE US BEGINNING TO ENJOY THE INFLUENCE OF SOME RIDGING AND FAIRER CONDITIONS. TEMPS WILL BE COOLER THAN NORMAL THROUGH THE END OF THE WEEK BEFORE BEGINNING TO MODERATE FOR THE WEEKEND. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... PATCH OF VERY FINE SNOW OUT AHEAD OF THE MAIN PRECIPITATION AREA. 03Z TAFS ADJUSTED AND SENT. BFD OB MISSING AT TIMES...STILL ABLE TO CALL UP. EARLIER DISCUSSION BELOW. LOWER CLDS CAME IN SOONER THAN WHAT I LOOKED AT LAST NIGHT. ANYWAY...RADAR AND OBS SUPPORT ISOLATED POCKETS OF VERY LIGHT PCPN THIS EVENING. AN AREA OF LOW PRESSURE OFF THE SOUTHEAST COAST WILL TRAVEL NORTH NORTHWESTWARD TONIGHT...DEEPEN JUST OFF THE DELMARVA TUESDAY...THEN DRIFT NORTH OVER LONG ISLAND AND CONNECTICUT TUESDAY NIGHT. STRONG ONSHORE FLOW ASSOCIATED WITH THIS SURFACE LOW WILL SPREAD LOW CIGS AND MIXED PRECIPITATION INTO THE S-CENTRAL/SERN AIRFIELDS FROM LATE THIS EVE INTO TONIGHT. TEMPERATURES WILL HOVER NEAR FREEZING OVERNIGHT...RESULTING IN AN ARRAY OF PRECIP TYPES FOR TONIGHT INTO TUESDAY MORNING AND PROLONGED PERIODS OF MVFR/IFR CONDITIONS THROUGH TUESDAY EVENING. THE STRONG FLOW WILL ALSO RESULT IN N-NW WINDS OF 15-20 KTS WITH HIGHER GUSTS POSSIBLE ACROSS THE EAST. AREAS OF LOW LEVEL WIND SHEAR REMAIN POSSIBLE AS WELL. DID GO WITH MAINLY RAIN BY 18Z TUE...EXCEPT FOR BFD. THIS STORM WILL BE SLOW MOVING AND INFLUENCE THE WEATHER PATTERN IN CENTRAL PA THROUGH THE MIDDLE AND PERHAPS THE END OF THE WEEK. RETURN OF HIGH PRESSURE SHOULD SPELL IMPROVING CONDITIONS BY THE WEEKEND. OUTLOOK... WED-THU...MVFR/IFR IN PERIODS OF SNOW/SNOW SHOWERS. STRONG N-NW WINDS 15-20KTS WITH HIGHER GUSTS POSSIBLE. FRI...BECOMING VFR WITH HIGH PRESSURE. SAT...VFR WITH HIGH PRESSURE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WATCH FROM 5 AM EST TUESDAY THROUGH WEDNESDAY MORNING FOR PAZ037-041-042-053-058. WINTER WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR PAZ010>012- 017>019-024>028-033>036-045-046-049>052-056-057-059-063>066. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1002 PM EST MON DEC 8 2014 .SYNOPSIS... LOW PRESSURE FORMING EAST OF THE CAROLINA COAST WILL MOVE UP THE EAST COAST AND BRING AN EXTENDED PERIOD OF WINTRY WEATHER TO THE REGION. BLUSTERY NORTHWEST FLOW WITH AREAS OF SNOW SHOWERS WILL FOLLOW THIS STORM FOR THE SECOND HALF OF THE WEEK. && .NEAR TERM /TONIGHT/... PRECIP LIFTING NORTH INTO THE SC MTNS LATE THIS EVENING IN REGION OF LG SCALE FORCING AHEAD OF LEAD SHORTWAVE OVR THE S APPALACHIANS. SATL-DERIVED PWAT LOOP SHOWING DEEP LVL MOISTURE LIFTING NORTHWARD THRU THE MID ATLANTIC REGION ALONG AXIS OF EASTERLY LL JET. HAVE ACCELERATED THE ARRIVAL OF PRECIP BASED ON RADAR TRENDS AND ALSO HAVE TRENDED PTYPE TO MOSTLY SNOW ACROSS THE SPINE OF THE ALLEGHENIES BASED ON UPSTREAM REPORTS AND LATEST HRRR OUTPUT...WHICH SUGGESTS A STRIPE OF A COUPLE INCHES OF SNOW IS NOW POSSIBLE LATE TONIGHT FROM SOMERSET/BEDFORD CO NEWRD INTO THE CENTRAL MTNS. FURTHER EAST...STILL THINKING A PERIOD OF FZRA IS MOST LIKELY OVR THE SUSQ VALLEY EARLY TUE AM. BLEND OF 18Z CONSALL AND LATEST LAMP/HRRR OUTPUT SUGGEST TEMPS BY DAWN WILL RANGE FROM THE U20S OVR THE ALLEGHENY MTNS...TO PERHAPS JUST ABV FREEZING OVR LANCASTER CO. && .SHORT TERM /7 AM TUESDAY THROUGH TUESDAY NIGHT/... STILL A VERY UNCERTAIN FORECAST DESPITE HOW CLOSE WE ARE TO THE ONSET OF THINGS. A LOW DEVELOPING OFF THE CAROLINA COAST WILL MOVE DUE NORTH AND UP ALONG THE NJ COAST TUESDAY INTO WEDNESDAY. GIVEN THIS SLIGHTLY OFFSHORE TRACK...EASTERN PA WILL BEAR THE BRUNT OF THE STORM WITH THE POTENTIAL FOR HEAVY RAIN OVR SE PA...AND POSSIBLY SOME SIG SNOW OVER THE HIGHER ELEVATIONS OF TIOGA/SULLIVAN/SCHUYLKILL COUNTIES. WILL LIKELY BE ABLE TO CANCEL WINT WX ADVISORY BEFORE 18Z...AS NEARLY ALL GUIDANCE INDICATES TEMPS RISING WELL ABV FREEZING BY LATE AM. MAIN CONCERN WILL BE THE EARLY AM COMMUTE FOR A MIXTURE OF SNOW AND FRZA. MAIN FCST ISSUE REMAINS HOW FAR WEST SIG PRECIP CAN BE DRAGGED INTO CENTRAL PA. MODELS ARE CONSISTENT IN A PRETTY SHARP BACK EDGE CUTTING OFF MOST OF THE PRECIP SOMEWHERE BETWEEN STATE COLLEGE AND PERHAPS WILLIAMSPORT-HARRISBURG. WITH THE UNCERTAINTY STILL HIGH...WE KEPT THE WINTER STORM WATCH UP FOR OUR HIGHER ELEVATIONS FROM TIOGA SOUTH DOWN INTO SCHUYLKILL COUNTY...EMPHASIZING THE BEST CHANCE FOR HEAVY WET SNOW BEING OVER THOSE HIGHER ELEVATIONS. LATEST RAP...21Z SREF AND 00Z NAM ALL SUGGEST ENOUGH WARM AIR OVERSPREADS EASTERN PA TO TURN THE BULK OF THE PRECIP TO RAIN BTWN LATE AM AND TUE AFTN OVR OUR NE COUNTIES. HOWEVER...DEVELOPING DEFORMATION BAND ON THE NW PERIPHERY OF MID LVL LOW COULD STILL POTENTIALLY PRODUCE SIG SNOW TUE NIGHT FROM TIOGA CO SOUTH THRU SCHUYLKILL CO. THE LOW IS EXPECTED TO REACH THE NJ COAST AROUND MID DAY TUESDAY AND SLOW DOWN OR EVEN STALL FOR PERHAPS A DAY OR MORE AS THE UPPER LOW CAPTURES THE SYSTEM. WHILE MUCH OF OUR FORECAST AREA WILL LIKELY WARM ENOUGH TO MAKE FOR JUST PLAIN RAIN DURING THE DAY TUESDAY...THIS WILL EVENTUALLY CAUSE COLDER AIR TO COME IN AT ALL LEVELS AND CHANGE THE MIXED PRECIP BACK TO MAINLY SNOW TUESDAY NIGHT AND INTO WED. IT`S STILL UNCLEAR HOW MUCH PRECIP WILL RESULT AS THE MODELS DIFFER GREATLY ON THE DEVELOPMENT OF A POSSIBLE DEFORMATION ZONE. THE SOLUTIONS FALL BETWEEN THE ECMWF THAT TARGETS MY NWRN ZONES EVEN THROUGH WED INTO THURSDAY...TO THE GFS THAT SHOWS ALMOST NO PRECIP WRAPPING BACK. I KEPT A GOOD CHANCE OF MAINLY LIGHT QPF IN THE FORECAST THROUGH THURSDAY BEFORE TAPERING OFF THE ACTIVITY FOR THE REMAINDER OF THE WEEK. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WITH THE LOW MOVING VERY SLOWLY IF AT ALL...THE CHANCES FOR AT LEAST SOME LIGHT SNOW WILL REMAIN HIGH WEDNESDAY INTO THURSDAY. I GENERALLY KEPT AMOUNTS LOW...DEPENDENT ON THE FORMATION OF THE DEFORMATION ZONE MENTIONED EARLIER...OR NOT. BY THE END OF THE WEEK GUIDANCE IS IN DECENT AGREEMENT FOR THE UPPER LOW TO NUDGE EAST ENOUGH TO HAVE US BEGINNING TO ENJOY THE INFLUENCE OF SOME RIDGING AND FAIRER CONDITIONS. TEMPS WILL BE COOLER THAN NORMAL THROUGH THE END OF THE WEEK BEFORE BEGINNING TO MODERATE FOR THE WEEKEND. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... LOWER CLDS CAME IN SOONER THAN WHAT I LOOKED AT LAST NIGHT. ANYWAY...RADAR AND OBS SUPPORT ISOLATED POCKETS OF VERY LIGHT PCPN THIS EVENING. AN AREA OF LOW PRESSURE OFF THE SOUTHEAST COAST WILL TRAVEL NORTH NORTHWESTWARD TONIGHT...DEEPEN JUST OFF THE DELMARVA TUESDAY...THEN DRIFT NORTH OVER LONG ISLAND AND CONNECTICUT TUESDAY NIGHT. STRONG ONSHORE FLOW ASSOCIATED WITH THIS SURFACE LOW WILL SPREAD LOW CIGS AND MIXED PRECIPITATION INTO THE S-CENTRAL/SERN AIRFIELDS FROM LATE THIS EVE INTO TONIGHT. TEMPERATURES WILL HOVER NEAR FREEZING OVERNIGHT...RESULTING IN AN ARRAY OF PRECIP TYPES FOR TONIGHT INTO TUESDAY MORNING AND PROLONGED PERIODS OF MVFR/IFR CONDITIONS THROUGH TUESDAY EVENING. THE STRONG FLOW WILL ALSO RESULT IN N-NW WINDS OF 15-20 KTS WITH HIGHER GUSTS POSSIBLE ACROSS THE EAST. AREAS OF LOW LEVEL WIND SHEAR REMAIN POSSIBLE AS WELL. DID GO WITH MAINLY RAIN BY 18Z TUE...EXCEPT FOR BFD. THIS STORM WILL BE SLOW MOVING AND INFLUENCE THE WEATHER PATTERN IN CENTRAL PA THROUGH THE MIDDLE AND PERHAPS THE END OF THE WEEK. RETURN OF HIGH PRESSURE SHOULD SPELL IMPROVING CONDITIONS BY THE WEEKEND. OUTLOOK... WED-THU...MVFR/IFR IN PERIODS OF SNOW/SNOW SHOWERS. STRONG N-NW WINDS 15-20KTS WITH HIGHER GUSTS POSSIBLE. FRI...BECOMING VFR WITH HIGH PRESSURE. SAT...VFR WITH HIGH PRESSURE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WATCH FROM 5 AM EST TUESDAY THROUGH WEDNESDAY MORNING FOR PAZ037-041-042-053-058. WINTER WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR PAZ010>012- 017>019-024>028-033>036-045-046-049>052-056-057-059-063>066. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
905 PM CST MON DEC 8 2014 .UPDATE... ISSUED AT 904 PM CST MON DEC 8 2014 SHORT TERM CLOUD TRENDS HAVE BEEN CHALLENGING TO SAY THE LEAST. STRONG PUSH OF CLEARING HAS OCCURRED FROM THE JAMES VALLEY THROUGH I 29 CORRIDOR IN THE VICINITY OF THE LOW LEVEL RIDGE AXIS... NARROWING AND BACKING BAND OF LOWER CLOUDS ACROSS THE FAR WESTERN CWA...WHILE BREAKS HAVE DEVELOPED IN CLOUDS ACROSS THE EAST...BUT FAR LESS IMPRESSIVELY. IN CLEARING...TEMPS HAVE FALLEN MUCH FASTER AS HAVE THE WINDS...WHILE STILL GUSTY AND RELATIVELY WARMER UNDER CLOUDS TO EAST. CLEARING WEDGE WILL CONTINUE TO WORK SOUTHWARD LATE THIS EVENING WHILE A SLOWER BACKING TO NARROW BAND OF LOW CLOUDS WORKS OUT OF SOUTH CENTRAL. WILL SEE CLOUDS AGAIN INCREASE FROM THE NORTH ALONG/EAST OF THE I29 CORRIDOR AS FINAL LOBE WRAPS SOUTHEAST ACROSS THE AREA...WITH GENERAL NORTH TO NORTHEAST FLOW IN CLOUD BEARING LEVELS. DOWNSLOPE OFF THE RIDGE WITH NARROWING MOISTURE DEPTH COULD CREATE A FEW ISSUES WORKING CLOUDS MUCH SOUTHWEST PAST KFSD...AND EVEN TO KFSD. COULD POSSIBLY SEE A FEW FLURRIES START TO FLUTTER THROUGH SKIES IN THE NORTHEAST AFTER 08Z...BUT AT THIS POINT NOT MUCH MERIT IN THE MENTION WITH TEMPS IN THE CLOUD LAYER SOMEWHAT MARGINAL. HAVE TRIMMED A COUPLE OF LOWS DOWN A BIT IN VICINITY OF RIDGE AXIS AND CLEARING...BUT IN GENERAL EVEN ADVECTION WILL TAKE LOWS TO EARLIER LEVELS...JUST A BIT QUICKER OF A START THIS EVENING TO THOSE ENDS. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 244 PM CST MON DEC 8 2014 THE MAIN QUESTION THROUGH THIS EVENING IS THE STATUS OF THE LOW CLOUD COVER WHICH HAD BEEN SPREADING SOUTH OVER THE AREA. THAT SPREAD HAS DONE A NEAR HALT AS THE MOISTURE ADVECTION RUNS INTO THE HEATED AIR NEAR THE MISSOURI RIVER. IT SEEMS WITH THE START OF EARLY EVENING COOLING THAT THE DECK WOULD AGAIN START SPREADING SOUTH. CLEARING OF THE LOW CLOUDS HAS CONTINUED TO PROGRESS SOUTH ACROSS NORTH DAKOTA AND WAS STARTING TO GET INTO FAR NORTHERN SOUTH DAKOTA AT 20Z. BOTH THE NAM AND RAP SUGGEST THE 925 MB FLOW WILL CONTINUE TO GO STRAIGHT NORTHERLY AND CONTINUE THUS OVER THE AREA THROUGH 06Z/MIDNIGHT...THOUGH DECREASING SLOWLY DURING THE EVENING. EXPECT THIS WILL GIVE THE DRYING CONTINUED TRANSPORT SOUTH ACROSS THE AREA DURING THE EVENING AND NOT ALLOW THE SOLID CLOUD COVER TO GET ALL THE WAY TO THE RIVER...OR OF IT BRIEFLY DOES...IT SHOULD CLEAR OUT AGAIN FAIRLY QUICKLY. AM PLANNING FOR A LITTLE INCREASE IN THE LOW CLOUDS THERE BUT WITH THE WARM AIR THERE CURRENTLY AND DRYING FROM THE NORTH DURING THE EVENING...HAVE KEPT THE INCREASE VERY MODEST BEFORE IT CLEARS OUT EVERYWHERE TONIGHT. TEMPERATURES WILL COOL STEADILY TONIGHT GIVEN THE CLEARING AND DROPOFF IN WINDS...WITH LOWS BEING REACH ABOUT SUNRISE AT 8 AM. WINDS BY THEN SHOULD BE PRETTY LIGHT THOUGH WITH A 5 TO 5 MPH NORTHERLY BREEZE IN THE EAST LINGERING TO SUNUP. TUESDAY WILL BRING AN INCREASE IN HIGH AND SOME MIDDLE CLOUDS WITH UPPER LEVEL SHORT WAVE DRIFTING INTO THE AREA. HAVE GONE PRETTY CONSERVATIVE IN CLOUD COVER AND IF THEY HIGHER CLOUDS ARE THICK ENOUGH IT COULD GET MOSTLY CLOUDY FOR PART OF THE DAY. IN ANY EVENT HEATING BY THE DECEMBER SUN WILL NOT BE ABLE TO TAKE ADVANTAGE OF MUCH OF THE WARMING UPSTAIRS EVEN WITH NO SNOW COVER...AND FORECAST HIGHS WILL REMAIN AROUND 30 NORTHEAST TO THE LOWER 40S SOUTHWEST. WINDS WILL BE FAIRLY LIGHT THOUGH...WITH THE DEVELOPING SOUTHEASTERLY SURFACE BREEZE PICKING TO 10 PLUS IN THE AFTERNOON WEST OF THE JAMES RIVER. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 244 PM CST MON DEC 8 2014 MEDIUM AND EXTENDED FORECAST CONTINUES TO LOOK VERY WARM AND MOSTLY DRY. TUESDAY NIGHT INTO WEDNESDAY...A MINOR SHORTWAVE WILL MOVE ACROSS THE REGION. SOUNDINGS CONTINUE TO SHOW LIMITED MOISTURE WITH THIS WAVE...WITH AN INCREASE IN MID-LVL CLOUDS AND VIRGA POSSIBLE GIVEN DRY SUB-CLOUD LAYER. THE WARMUP BEGINS TO BUILD ON WEDNESDAY BEHIND THIS SHORTWAVE ENERGY. AS LOW LVL TEMPERATURES BUILD...SURFACE WINDS WILL SLOWLY BEGIN TO VEER SOUTHWEST THROUGH THE DAY. WARM AIR WILL BE SLOW TO MIX TO THE SURFACE ON WEDNESDAY...BUT NEAR 40 READINGS SHOULD BE ATTAINABLE. THURSDAY THROUGH SATURDAY LOOK TO BE VERY WARM AS DEEP SOUTHWESTERLY FLOW PULLS BOTH MOISTURE AND WARM AIR OVER MUCH OF THE CENTRAL CONUS. IT CONTINUES TO LOOK LIKE STRATUS WILL DEVELOP AND MOVE NORTHWARD INTO THE REGION BY THURSDAY. TEMPERATURES WILL PROGRESSIVELY WARM EACH AFTERNOON...WITH THE 40S LIKELY ON THURSDAY AND 40S AND 50S ON FRIDAY. TEMPERATURES MAY NOT FALL VERY FALL FRIDAY NIGHT INTO SATURDAY...AND CURRENT LOWS MAY STILL BE TOO LOW. THE DEEP SOUTHERLY FLOW AND SUBSTANTIAL MOISTURE SHOULD NOT ALLOW FOR ANY EXTREME JUMP ON SATURDAY...BUT A GRADUAL WARMING INTO THE MID 50S AND POTENTIALLY EVEN DRIZZLE. A COLD FRONT WILL SWING THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY...DROPPING TEMPERATURES BACK NEAR THEIR SEASONAL NORMALS. THE CHANCES FOR PRECIPITATION AS THIS FRONT MOVES THROUGH CONTINUE TO BE LOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 533 PM CST MON DEC 8 2014 MVFR CEILINGS WILL DOMINATE ACROSS MUCH OF THE AREA THROUGH THIS EVENING...THOUGH A WEDGE OF CLEARING PUSHING SOUTH THROUGH THE JAMES RIVER VALLEY WILL MAKE VFR CONDITIONS MORE LIKELY FOR KHON/KMHE. OVERNIGHT FORECAST FOR KFSD/KSUX MORE UNCERTAIN AS THIS MOISTURE LAYER GRADUALLY BECOMES MORE SHALLOW AS THE NIGHT PROGRESSES...AND POSSIBLE THE CLOUD DECK MAY EVENTUALLY JUST BECOME MORE SCATTERED WITH TIME IN THESE AREAS...WHILE MORE SOLID DECK PERSISTS WEST OF THE JAMES RIVER VALLEY AND EAST OF INTERSTATE 29. THUS FORECAST CONDITIONS TO IMPROVE TO VFR AT KFSD/KSUX BY LATE EVENING/JUST AFTER MIDNIGHT...BUT PRESENTLY HAVE LOW CONFIDENCE IN THIS TIMING...AND ADJUSTMENTS CERTAINLY POSSIBLE AFTER WATCHING TRENDS OVER THE NEXT COUPLE OF HOURS. OCCASIONAL GUSTS OF 20-26KT WITHIN THE STRATUS LAYER EARLY THIS EVENING EXPECTED TO BECOME LESS FREQUENT BY LATE EVENING. GREATER CONFIDENCE IN VFR CONDITIONS PREVAILING ACROSS THE AREA BY SHORTLY AFTER SUNRISE TUESDAY...WITH CONDITIONS THEN REMAINING VFR THROUGH THE END OF THE PERIOD. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...CHAPMAN SHORT TERM... LONG TERM...DUX AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
533 PM CST MON DEC 8 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 244 PM CST MON DEC 8 2014 THE MAIN QUESTION THROUGH THIS EVENING IS THE STATUS OF THE LOW CLOUD COVER WHICH HAD BEEN SPREADING SOUTH OVER THE AREA. THAT SPREAD HAS DONE A NEAR HALT AS THE MOISTURE ADVECTION RUNS INTO THE HEATED AIR NEAR THE MISSOURI RIVER. IT SEEMS WITH THE START OF EARLY EVENING COOLING THAT THE DECK WOULD AGAIN START SPREADING SOUTH. CLEARING OF THE LOW CLOUDS HAS CONTINUED TO PROGRESS SOUTH ACROSS NORTH DAKOTA AND WAS STARTING TO GET INTO FAR NORTHERN SOUTH DAKOTA AT 20Z. BOTH THE NAM AND RAP SUGGEST THE 925 MB FLOW WILL CONTINUE TO GO STRAIGHT NORTHERLY AND CONTINUE THUS OVER THE AREA THROUGH 06Z/MIDNIGHT...THOUGH DECREASING SLOWLY DURING THE EVENING. EXPECT THIS WILL GIVE THE DRYING CONTINUED TRANSPORT SOUTH ACROSS THE AREA DURING THE EVENING AND NOT ALLOW THE SOLID CLOUD COVER TO GET ALL THE WAY TO THE RIVER...OR OF IT BRIEFLY DOES...IT SHOULD CLEAR OUT AGAIN FAIRLY QUICKLY. AM PLANNING FOR A LITTLE INCREASE IN THE LOW CLOUDS THERE BUT WITH THE WARM AIR THERE CURRENTLY AND DRYING FROM THE NORTH DURING THE EVENING...HAVE KEPT THE INCREASE VERY MODEST BEFORE IT CLEARS OUT EVERYWHERE TONIGHT. TEMPERATURES WILL COOL STEADILY TONIGHT GIVEN THE CLEARING AND DROPOFF IN WINDS...WITH LOWS BEING REACH ABOUT SUNRISE AT 8 AM. WINDS BY THEN SHOULD BE PRETTY LIGHT THOUGH WITH A 5 TO 5 MPH NORTHERLY BREEZE IN THE EAST LINGERING TO SUNUP. TUESDAY WILL BRING AN INCREASE IN HIGH AND SOME MIDDLE CLOUDS WITH UPPER LEVEL SHORT WAVE DRIFTING INTO THE AREA. HAVE GONE PRETTY CONSERVATIVE IN CLOUD COVER AND IF THEY HIGHER CLOUDS ARE THICK ENOUGH IT COULD GET MOSTLY CLOUDY FOR PART OF THE DAY. IN ANY EVENT HEATING BY THE DECEMBER SUN WILL NOT BE ABLE TO TAKE ADVANTAGE OF MUCH OF THE WARMING UPSTAIRS EVEN WITH NO SNOW COVER...AND FORECAST HIGHS WILL REMAIN AROUND 30 NORTHEAST TO THE LOWER 40S SOUTHWEST. WINDS WILL BE FAIRLY LIGHT THOUGH...WITH THE DEVELOPING SOUTHEASTERLY SURFACE BREEZE PICKING TO 10 PLUS IN THE AFTERNOON WEST OF THE JAMES RIVER. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 244 PM CST MON DEC 8 2014 MEDIUM AND EXTENDED FORECAST CONTINUES TO LOOK VERY WARM AND MOSTLY DRY. TUESDAY NIGHT INTO WEDNESDAY...A MINOR SHORTWAVE WILL MOVE ACROSS THE REGION. SOUNDINGS CONTINUE TO SHOW LIMITED MOISTURE WITH THIS WAVE...WITH AN INCREASE IN MID-LVL CLOUDS AND VIRGA POSSIBLE GIVEN DRY SUB-CLOUD LAYER. THE WARMUP BEGINS TO BUILD ON WEDNESDAY BEHIND THIS SHORTWAVE ENERGY. AS LOW LVL TEMPERATURES BUILD...SURFACE WINDS WILL SLOWLY BEGIN TO VEER SOUTHWEST THROUGH THE DAY. WARM AIR WILL BE SLOW TO MIX TO THE SURFACE ON WEDNESDAY...BUT NEAR 40 READINGS SHOULD BE ATTAINABLE. THURSDAY THROUGH SATURDAY LOOK TO BE VERY WARM AS DEEP SOUTHWESTERLY FLOW PULLS BOTH MOISTURE AND WARM AIR OVER MUCH OF THE CENTRAL CONUS. IT CONTINUES TO LOOK LIKE STRATUS WILL DEVELOP AND MOVE NORTHWARD INTO THE REGION BY THURSDAY. TEMPERATURES WILL PROGRESSIVELY WARM EACH AFTERNOON...WITH THE 40S LIKELY ON THURSDAY AND 40S AND 50S ON FRIDAY. TEMPERATURES MAY NOT FALL VERY FALL FRIDAY NIGHT INTO SATURDAY...AND CURRENT LOWS MAY STILL BE TOO LOW. THE DEEP SOUTHERLY FLOW AND SUBSTANCIAL MOISTURE SHOULD NOT ALLOW FOR ANY EXTREME JUMP ON SATURDAY...BUT A GRADUAL WARMING INTO THE MID 50S AND POTENTIALLY EVEN DRIZZLE. A COLD FRONT WILL SWING THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY...DROPPING TEMPERATURES BACK NEAR THEIR SEASONAL NORMALS. THE CHANCES FOR PRECIPITATION AS THIS FRONT MOVES THROUGH CONTINUE TO BE LOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 533 PM CST MON DEC 8 2014 MVFR CEILINGS WILL DOMINATE ACROSS MUCH OF THE AREA THROUGH THIS EVENING...THOUGH A WEDGE OF CLEARING PUSHING SOUTH THROUGH THE JAMES RIVER VALLEY WILL MAKE VFR CONDITIONS MORE LIKELY FOR KHON/KMHE. OVERNIGHT FORECAST FOR KFSD/KSUX MORE UNCERTAIN AS THIS MOISTURE LAYER GRADUALLY BECOMES MORE SHALLOW AS THE NIGHT PROGRESSES...AND POSSIBLE THE CLOUD DECK MAY EVENTUALLY JUST BECOME MORE SCATTERED WITH TIME IN THESE AREAS...WHILE MORE SOLID DECK PERSISTS WEST OF THE JAMES RIVER VALLEY AND EAST OF INTERSTATE 29. THUS FORECAST CONDITIONS TO IMPROVE TO VFR AT KFSD/KSUX BY LATE EVENING/JUST AFTER MIDNIGHT...BUT PRESENTLY HAVE LOW CONFIDENCE IN THIS TIMING...AND ADJUSTMENTS CERTAINLY POSSIBLE AFTER WATCHING TRENDS OVER THE NEXT COUPLE OF HOURS. OCCASIONAL GUSTS OF 20-26KT WITHIN THE STRATUS LAYER EARLY THIS EVENING EXPECTED TO BECOME LESS FREQUENT BY LATE EVENING. GREATER CONFIDENCE IN VFR CONDITIONS PREVAILING ACROSS THE AREA BY SHORTLY AFTER SUNRISE TUESDAY...WITH CONDITIONS THEN REMAINING VFR THROUGH THE END OF THE PERIOD. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM...DUX AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
232 PM CST SUN DEC 7 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 230 PM CST SUN DEC 7 2014 UPPER LOW PUSHING ACROSS NORTH DAKOTA AT THIS TIME...DRAGGING A COLD FRONT ACROSS THE REGION. STRATUS IS ERODING FROM WEST TO EAST...WITH TEMPERATURES JUMPING INTO THE 40S AND 50S ALONG AND WEST OF THE JAMES RIVER. READINGS STUCK IN THE 30S ALONG AND EAST OF INTERSTATE 29 WHERE LOW STRATUS IS HOLDING. SEEING PATCHY DRIZZLE AHEAD OF THE FRONT WHERE DEEPER SATURATION AND WEAK LIFT IS PRESENT. SOME AREAS STILL HOLDING RIGHT AROUND FREEZING NEAR THE BUFFALO RIDGE AND ADJACENT AREAS OF NORTHWEST IOWA. DRIZZLE IS PRETTY LIGHT AND NOT HEARING OF ANY ISSUES...BUT SOME ICY SPOTS ARE STILL A POSSIBILITY THROUGH THIS AFTERNOON IN THOSE AREAS. EXPECT STRATUS TO CLEAR INTERSTATE 29 BY MID AFTERNOON...WITH CLEARING PUSHING INTO NORTHWEST IOWA THIS EVENING. SOME STRATUS...FOG AND DRIZZLE MAY LINGER IN OUR FAR EAST UNTIL AROUND MIDNIGHT. FOCUS THEN IS ON THE UPPER LOW THAT MOVES ACROSS TONIGHT. CURRENTLY SEEING SOME LOWER CLOUDS AND LIGHT PRECIPITATION WITH THIS FEATURE ACROSS WESTERN MONTANA...AND MODELS ARE CONSISTENT IN BRINGING THIS INTO OUR AREA TONIGHT. THUS WILL LIKELY SEE A RETURN OF STRATUS...ESPECIALLY EAST OF THE JAMES RIVER. SATURATION DOES GET PRETTY DEEP WITH SOME WEAK LIFT AS WELL...THUS SEEMS LIKE DRIZZLE MAY AGAIN BE A POSSIBILITY. EXPECT TEMPERATURES TO MAINLY BE ABOVE FREEZING...ALTHOUGH BY LATE TONIGHT MOST OF THE REGION SHOULD FALL BACK BELOW FREEZING. THUS MAY BE A FEW ICY SPOTS AGAIN BY MORNING...BUT AT THIS TIME NOT EXPECTING PRECIPITATION TO BE HEAVY ENOUGH TO CAUSE MUCH OF AN ISSUE. WILL MONITOR TRENDS OVERNIGHT. STRATUS AND STRATOCU WILL LIKELY HOLD THROUGH THE DAY MONDAY...WITH CLOUDY SKIES OVER SOUTHWEST MINNESOTA...PARTLY TO MOSTLY CLOUDY FROM HURON TO SIOUX FALLS TO SIOUX CITY AND MOSTLY SUNNY WEST OF THE JAMES RIVER. HIGHS WILL RANGE FROM AROUND 30 IN SOUTHWEST MINNESOTA TO THE LOW AND MID 40S ALONG THE MISSOURI RIVER. AS THE SECONDARY COLD FRONT MOVES THROUGH IN THE EARLY AFTERNOON...EXPECT TEMPERATURES NORTH OF INTERSTATE 90 TO REMAIN STEADY OR SLOWLY FALL THROUGH THE AFTERNOON HOURS. WILL BE BREEZY OUT OF THE NORTHWEST AS WELL WITH GUSTS OF 25 TO 35 MPH. AT THIS TIME THINK IT STAYS DRY...ALTHOUGH CAN NOT RULE OUT A FEW FLURRIES WITH THE CLOUDS IN SOUTHWEST MINNESOTA. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 230 PM CST SUN DEC 7 2014 ONLY MINOR ADJUSTMENTS MADE TO THE ONGOING FORECAST FROM MONDAY NIGHT THROUGH NEXT WEEKEND. FORECAST REMAINS ON TRACK SHOWING A SECONDARY COLD FRONT ARRIVING LATE MONDAY AFTERNOON OR MONDAY EVENING. THE COLDEST DAY OF THE NEXT 7 DAYS WILL FALL ON TUESDAY AS READINGS STRUGGLE TO REACH THE FREEZING MARK. TEMPERATURES COULD BE A SHADE TOO WARM EVEN...ESPECIALLY OVER THE CENTRAL ZONES. WE HAVE TO CONTINUE MONITORING MINOR SHORTWAVE MOVING THROUGH THE PLAINS TUESDAY NIGHT INTO WEDNESDAY. NAM/GFS CONTINUE TO PULL OR LINGER LOW LVL MOISTURE WITHIN THE MISSOURI RIVER VALLEY. NAM SOUNDS SHOW A MUCH DEEPER MOISTURE LAYER THAN THE GFS...WHICH GIVEN WEAK ISENTROPIC LIFT COULD RESULT IN LIGHT DRIZZLE/FOG INTO WEDNESDAY MORNING SOUTH OF I-90. GIVEN THE AFOREMENTIONED MODELS OVER FORECASTING OF MOISTURE...WILL HOLD OFF ON ANY PRECIP MENTION ATTM. FROM THURSDAY-SUNDAY...A VERY WARM PATTERN CONTINUES TO SHOW ITS HAND...ESPECIALLY FOR FRIDAY AND SATURDAY. LOW LVL MOISTURE AND STRATUS WILL CONTINUE TO PLAY A ROLE...HOWEVER THE PERSISTENT SOUTHWESTERLY FLOW WILL CONTINUE TO ADVECT THE WARMER AIR OFF THE SOUTHERN AND WESTERN PLAINS NORTHEAST INTO THE WEEKEND. AGAIN...HAVE TRENDED TOWARDS WPC/ECMWF GUIDANCE...WHICH IS NO LONGER THAT MUCH WARMER THAN NUMBERS FROM ECMWF/GFS ENSEMBLE GUIDANCE PROGS. WHILE FEW ANALOGS EXISTS FOR THIS MID-DECEMBER SETUP...120 HR CIPS ANALOG GUIDANCE DOES SUGGEST 30-40 PERCENT PROBS OF 60 DEGREE READINGS OVER THE WESTERN CWA ON FRIDAY...WITH NEARLY 60-80 PERCENT PROBS OF 50+ OVER MUCH OF THE CWA. GIVEN THE PERSISTENT SWLY LOW LVL AND BOUNDARY LAYER FLOW...CONCERNED THAT FRIDAY NIGHT LOWS COULD BE MUCH TOO COLD AND SATURDAY COULD BE EVEN WARMER THAN FRIDAY. STILL A FEW DAYS OUT TO WATCH MODEL GUIDANCE ADJUST. BEYOND THE WEEKEND...LITTLE TO NO CONFIDENCE IN THE WEATHER DETAILS BEYOND SUNDAY. LONG RANGE MODELS HANDLING THE EVENTUAL EASTWARD PROGRESSION AND PHASING OF SOUTHWESTERN ENERGY WITH NORTHERN STREAM MUCH DIFFERENTLY WITH EACH MODEL RUN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 230 PM CST SUN DEC 7 2014 STRATUS...FOG AND DRIZZLE CONTINUES TO EXIT THE AREA FROM WEST TO EAST THIS AFTERNOON. FOLLOWED CLOSE TO THE RAP FOR TIMING THE EXIT AND RETURN TO VFR. COULD SEE IFR TO LIFR FOG AND STRATUS LINGER ACROSS PORTIONS OF NORTHWEST IOWA UNTIL MIDNIGHT. AS THE UPPER LOW SWINGS ACROSS TONIGHT...EXPECT A RETURN TO MVFR CIGS. COULD EVEN BE LOWER FOR A PERIOD...SO WILL HAVE TO WATCH UPSTREAM TRENDS. ALSO CAN NOT RULE OUT SOME DRIZZLE TONIGHT AS THE STRATUS RETURNS. TEMPERATURES SHOULD MAINLY BE ABOVE FREEZING WHEN ANY DRIZZLE OCCURS...ALTHOUGH A CHANCE WE COULD SEE SOME VERY LIGHT FREEZING DRIZZLE LATER TONIGHT...MAINLY NORTHEAST OF THE TAF SITES. MVFR CIGS MAY VERY WELL LINGER INTO MONDAY...ALTHOUGH ALL THREE TAF SITES WILL LIKELY BE NEAR THE EDGE OF THE BROKEN TO OVERCAST STRATUS DECK. NORTHWEST WINDS WILL BECOME BLUSTERY TONIGHT...AND REMAIN THAT WAY INTO MONDAY...WITH GUSTS OF 20 TO 30 KTS AT TIMES. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHENARD LONG TERM...DUX AVIATION...CHENARD
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
935 PM CST MON DEC 8 2014 .UPDATE... MINOR UPDATE TO ADJUST TEMPERATURES...DEWPOINT AND RH GRIDS SLIGHTLY TO BETTER ACCOUNT FOR RECENT OBSERVATIONS AND TRENDS. WE DID ALSO A MENTION OF DENSE FOG OVER THE EASTERN ROLLING PLAINS BEFORE 06Z...WITH A MORE WIDESPREAD FOG MENTION THEREAFTER. LATEST SATELLITE IMAGERY SHOWS AN EXPANDING AREA OF LOW CLOUDS AND FOG EXTENDING FROM THE FAR EASTERN FRINGES OF THE SOUTHEASTERN CWA INTO WESTERN NORTH TEXAS. KSPS HAS ALREADY REPORTED VISIBILITIES DOWN TO 1/4 MILE IN FOG...AND WITH TEMPERATURES APPROACHING THE DEWPOINT IN THE EASTERN ROLLING PLAINS...WE COULD SEE DENSE FOG MATERIALIZE HERE TOO OVER THE NEXT FEW HOURS. ADDITIONALLY...THOUGH PERHAPS LESS WIDESPREAD...FOG MAY BE POSSIBLE UP ON THE CAPROCK LATER TONIGHT /WELL AFTER MIDNIGHT/. WE WILL CONTINUE TO MONITOR THE PROGRESS OF THE FOG AND A DENSE FOG ADVISORY MAY BE NEEDED FOR PARTS OF THE CWA LATER TONIGHT. && .PREV DISCUSSION... /ISSUED 523 PM CST MON DEC 8 2014/ AVIATION... THIN BUT RICH LOW LEVEL MOISTURE IN PLACE TO THE SOUTHEAST OF KLBB AND SOUTH OF KCDS COULD BRING A PERIOD OF IFR CONDITIONS TO THE TERMINALS TONIGHT. 18Z WRF-NAM NOT AS PESSIMISTIC AS ITS 12Z RUN WHILE THE HRRR CONTINUES TO KEEP BEST POTENTIAL OFF THE CAPROCK AT KCDS. ALSO SOME QUESTION OF HOW MUCH HIGH CLOUDS MIGHT AFFECT COOLING AND THUS NARROWING OF TEMP-DEW SPREAD. WILL NOT MAKE MUCH IN THE WAY OF CHANGE ATTM WITH EXPECTATION THAT RESTRICTIONS TO VSBY AND/OR CIGS WILL BE NEAR OR AFTER 06Z. HOPEFULLY 00Z MODEL RUNS AND LATER HI-RES RUNS WILL ADD CLARITY. PREV DISCUSSION... /ISSUED 332 PM CST MON DEC 8 2014/ SHORT TERM... RIDGING WILL PERSIST ACROSS OUR AREA OVER THE NEXT 24 HOURS WITH VERY LITTLE...FROM A SYNOPTIC PERSPECTIVE...TO MAKE MUCH DIFFERENCE IN SENSIBLE WEATHER. SOUTHERLY FLOW WILL PERSIST ALTHOUGH WE WILL SEE A MORE SOUTHWESTERLY COMPONENTS ESPECIALLY WEST OF THE ESCARPMENT. THAT SAID...SPEEDS SHOULD BE QUITE LIGHT AND POTENTIAL FOR FOG WILL EXIST AREA WIDE. HOWEVER...THE MOST LIKELY LOCATION FOR DENSE FOG WILL BE ACROSS THE ROLLING PLAINS. YET...GIVEN THE INCREASING HIGH LEVEL CLOUDINESS APPARENT TO OUR WEST...EVEN THAT IS NOT GUARANTEED. SO...WILL STICK WITH MENTION OF FOG /PATCHY WEST TO AREAS EAST/ TONIGHT AND ALLOW THE OVERNIGHT SHIFTS TO ASSESS THE POTENTIAL FOR LOW VISIBILITIES. TEMPERATURES SHOULD REMAIN WITHIN A FEW DEGREES OF WHAT WE SAW DURING THE PREVIOUS 24 HOURS. LONG TERM... MENTIONABLE POPS HAVE BEEN REMOVED FOR WEDNESDAY THROUGH THURSDAY AS CHANCES LOOK TO BE MORE UNLIKELY. WHILE THERE WILL BE AMPLE MOISTURE AT THE LOW AND UPPER LEVELS...DRY AIR ASSOCIATED WITH SUBSIDENCE BETWEEN 800 AND 600 MB WILL PREVENT WHAT LITTLE PRECIP THAT MAY OCCUR FROM REACHING THE SURFACE. IN ADDITION TO DRY AIR...LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE WILL BE WEAK AT BEST. DESPITE A LACK OF PRECIP LOW LEVEL STRATUS WILL BE IN PLACE THROUGH WEDNESDAY INTO LATE THURSDAY MORNING. ALONG WITH STRATUS FOG WILL POSSIBLE ACROSS MUCH OF THE FA BOTH WEDNESDAY AND THURSDAY MORNING. FOG HAS BEEN LEFT OUT OF THE GRIDS FOR FRIDAY MORNING AS WINDS ARE EXPECTED TO TURN TO THE SOUTHWEST AS A LEE TROF APPROACHES THE AREA WHICH SHOULD HELP KEEP SURFACE RH VALUES LOWER. STRATUS SHOULD ALSO NOT BE AN ISSUE FRIDAY MORNING WITH MOSTLY DRY AIR WILL BE SITTING OVER THE REGION. BY FRIDAY AFTERNOON AN ELONGATED TROF WILL BE POSITIONED OVER THE PACIFIC COAST WITH THE LEE TROF DIGGING FURTHER SOUTHWARD. CONTINUOUS SURFACE WINDS OUT OF THE SOUTHWEST WILL HELP WARM TEMPS TO NEAR 70 ON FRIDAY AND SATURDAY. THE UPPER LEVEL TROF SHOULD BE NEAR THE FOOTHILLS OF THE ROCKIES BY LATE SATURDAY AND SHOULD BEGIN TO ELONGATE FURTHER SOUTHWARD. THE GFS HAS BEEN FAIRLY CONSISTENT WITH PINCHING OFF THE LOWER HALF OF THE TROF MAKING A CLOSED LOW WHICH WOULD GIVE THE REGION A DECENT SHOT AT PRECIP. UNTIL THE MORE RECENT 12Z RUN THE ECMWF SHOWED A SIMILAR BUT SLOWER SOLUTION. THE 12Z ECMWF KEEPS THE LOW CLOSED OFF ALONG THE US/CA BORDER WITH AN OPEN TROF IN THE SOUTH-CENTRAL CONUS. THOUGH THE TROF REMAINS OPEN IT MATCHES THE SPEED OF THE GFS ALMOST PERFECTLY. FOR NOW PRECIP CHANCES HAVE BEEN KEPT IN THE FORECAST STARTING LATE SATURDAY WITH HIGH POPS EXISTING OVER THE ROLLING PLAINS. THE BIGGER CHALLENGE COMES WITH PRECIP TYPE LATE SUNDAY AFTER A COLD FRONT PUSHES INTO THE REGION PENDING THAT THE LOW IS CLOSED. BOTH MODELS SHOW 850 MB TEMPS REMAIN ABOVE FREEZING BUT NOT BY MUCH. THE 00Z RUN OF THE ECMWF SHOWED 850 MB TEMPS DOWN TO -5C. SNOW WOULD NOT BE OUT OF THE REALM OF POSSIBILITY IF TEMPS CAN COOL DOWN FAST ENOUGH...BUT FOR NOW THE MENTION WILL BE FOR RAIN OR SNOW. REGARDLESS OF PRECIP TEMPERATURES SHOULD BE NOTICEABLY COLDER BEHIND THE FRONT WITH HIGHS AVERAGING IN THE MID 40S ON MONDAY WITH LOWS DIPPING BACK DOWN BELOW FREEZING FOR MUCH OF THE AREA. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 35 61 41 60 38 / 0 0 10 10 10 TULIA 35 61 42 59 42 / 0 0 10 10 10 PLAINVIEW 35 61 43 59 41 / 0 0 10 10 10 LEVELLAND 38 61 42 59 43 / 0 0 10 10 10 LUBBOCK 39 63 44 59 43 / 0 0 10 10 10 DENVER CITY 43 61 44 59 43 / 0 0 10 10 10 BROWNFIELD 40 61 44 59 45 / 0 0 10 10 10 CHILDRESS 39 66 43 62 47 / 0 0 10 10 10 SPUR 38 64 44 62 48 / 0 0 10 10 10 ASPERMONT 39 66 45 63 50 / 0 0 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07/23
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
544 PM CST MON DEC 8 2014 .AVIATION... /00Z TAFS/ Continuing along the lines of the previous TAF package, regarding uncertainty with the extent of low stratus and fog development tonight. The latest NAM12 and RUC13 indicate that fog and low stratus may initially develop across our northeastern counties early tonight, then develop (in a patchy nature) farther south and west through the overnight hours. Could have IFR to LIFR visibilities and ceilings at times, but with the uncertainty at this time, going with a conservative approach with visibility reductions, and by carrying scattered low cloud layers as opposed to ceilings. Will monitor conditions throughout the evening and tonight and will make adjustments as needed. Light winds will continue tonight, and should eventually become southeast at 4-7 kt on Tuesday afternoon. 19 && .PREV DISCUSSION... /ISSUED 325 PM CST Mon Dec 8 2014/ SHORT TERM... (Tonight and Tuesday) Skies have cleared across West Central Texas, allowing temperatures to warm into the mid 60s to near 70 degrees this afternoon. Winds remain light and variable across the region given the proximity to the surface anticyclone. This surface high will remain in place overnight but should shift far enough east to allow a return of weak southerly winds. With little change in the airmass and light winds in place across the area, fog and low stratus is expected to develop again tonight. This fog should remain patchy, and confidence is rather low regarding what areas will actually see the most significant reduced visibilities. Over the last two mornings, we have seen transient dense fog develop in various locations, with visibilities down to near zero at times. Fog is expected to lift in areas where low clouds develop. Otherwise, expect low temperatures in the lower 40s, possibly warming a few degrees if/when cloud cover develops. The fly in the ointment is the anticipated increase in high clouds. This could mitigate fog development. Pleasant weather conditions are anticipated on Tuesday. High clouds will continue to increase with southerly winds of 5 to 10 mph. No precipitation is expected throughout the day with temperatures warming into the mid and upper 60s. Johnson LONG TERM... (Tuesday night through Monday) As a weak upper ridge moves east of the area Tuesday night, a weak upper short wave will move east over New Mexico giving the forecast area our next chance of rainfall. The rainfall is expected to be light and will expand eastward from the southwestern CWA Tuesday night over the remaining CWA Wednesday through Thursday. The chance of rainfall will end on Friday as upper ridging builds over the area from the west in the wake of the departing upper short wave. Highs on Wednesday will be in the lower 60s warming into the Upper 60s to the lower 70s by Saturday. Models are closing an upper low over southern New Mexico Saturday night with the dryline tightening just west of the forecast area. Forcing along the Pacific front/dryline Saturday night will bring a chance of showers and thunderstorms over our western CWA Saturday night, expanding through the remainder of the forecast area through Sunday night. As the upper level system tracks east, an associated cold front will move across the forecast area on Sunday with cooler post-frontal highs on Monday ranging from the upper 40s to the lower 50s. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 41 66 48 62 51 / 0 0 5 20 20 San Angelo 41 67 49 62 52 / 0 0 10 30 20 Junction 39 67 47 61 51 / 0 0 10 40 40 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
523 PM CST MON DEC 8 2014 .AVIATION... THIN BUT RICH LOW LEVEL MOISTURE IN PLACE TO THE SOUTHEAST OF KLBB AND SOUTH OF KCDS COULD BRING A PERIOD OF IFR CONDITIONS TO THE TERMINALS TONIGHT. 18Z WRF-NAM NOT AS PESSIMISTIC AS ITS 12Z RUN WHILE THE HRRR CONTINUES TO KEEP BEST POTENTIAL OFF THE CAPROCK AT KCDS. ALSO SOME QUESTION OF HOW MUCH HIGH CLOUDS MIGHT AFFECT COOLING AND THUS NARROWING OF TEMP-DEW SPREAD. WILL NOT MAKE MUCH IN THE WAY OF CHANGE ATTM WITH EXPECTATION THAT RESTRICTIONS TO VSBY AND/OR CIGS WILL BE NEAR OR AFTER 06Z. HOPEFULLY 00Z MODEL RUNS AND LATER HI-RES RUNS WILL ADD CLARITY. && .PREV DISCUSSION... /ISSUED 332 PM CST MON DEC 8 2014/ SHORT TERM... RIDGING WILL PERSIST ACROSS OUR AREA OVER THE NEXT 24 HOURS WITH VERY LITTLE...FROM A SYNOPTIC PERSPECTIVE...TO MAKE MUCH DIFFERENCE IN SENSIBLE WEATHER. SOUTHERLY FLOW WILL PERSIST ALTHOUGH WE WILL SEE A MORE SOUTHWESTERLY COMPONENTS ESPECIALLY WEST OF THE ESCARPMENT. THAT SAID...SPEEDS SHOULD BE QUITE LIGHT AND POTENTIAL FOR FOG WILL EXIST AREA WIDE. HOWEVER...THE MOST LIKELY LOCATION FOR DENSE FOG WILL BE ACROSS THE ROLLING PLAINS. YET...GIVEN THE INCREASING HIGH LEVEL CLOUDINESS APPARENT TO OUR WEST...EVEN THAT IS NOT GUARANTEED. SO...WILL STICK WITH MENTION OF FOG /PATCHY WEST TO AREAS EAST/ TONIGHT AND ALLOW THE OVERNIGHT SHIFTS TO ASSESS THE POTENTIAL FOR LOW VISIBILITIES. TEMPERATURES SHOULD REMAIN WITHIN A FEW DEGREES OF WHAT WE SAW DURING THE PREVIOUS 24 HOURS. LONG TERM... MENTIONABLE POPS HAVE BEEN REMOVED FOR WEDNESDAY THROUGH THURSDAY AS CHANCES LOOK TO BE MORE UNLIKELY. WHILE THERE WILL BE AMPLE MOISTURE AT THE LOW AND UPPER LEVELS...DRY AIR ASSOCIATED WITH SUBSIDENCE BETWEEN 800 AND 600 MB WILL PREVENT WHAT LITTLE PRECIP THAT MAY OCCUR FROM REACHING THE SURFACE. IN ADDITION TO DRY AIR...LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE WILL BE WEAK AT BEST. DESPITE A LACK OF PRECIP LOW LEVEL STRATUS WILL BE IN PLACE THROUGH WEDNESDAY INTO LATE THURSDAY MORNING. ALONG WITH STRATUS FOG WILL POSSIBLE ACROSS MUCH OF THE FA BOTH WEDNESDAY AND THURSDAY MORNING. FOG HAS BEEN LEFT OUT OF THE GRIDS FOR FRIDAY MORNING AS WINDS ARE EXPECTED TO TURN TO THE SOUTHWEST AS A LEE TROF APPROACHES THE AREA WHICH SHOULD HELP KEEP SURFACE RH VALUES LOWER. STRATUS SHOULD ALSO NOT BE AN ISSUE FRIDAY MORNING WITH MOSTLY DRY AIR WILL BE SITTING OVER THE REGION. BY FRIDAY AFTERNOON AN ELONGATED TROF WILL BE POSITIONED OVER THE PACIFIC COAST WITH THE LEE TROF DIGGING FURTHER SOUTHWARD. CONTINUOUS SURFACE WINDS OUT OF THE SOUTHWEST WILL HELP WARM TEMPS TO NEAR 70 ON FRIDAY AND SATURDAY.THE UPPER LEVEL TROF SHOULD BE NEAR THE FOOTHILLS OF THE ROCKIES BY LATE SATURDAY AND SHOULD BEGIN TO ELONGATE FURTHER SOUTHWARD. THE GFS HAS BEEN FAIRLY CONSISTENT WITH PINCHING OFF THE LOWER HALF OF THE TROF MAKING A CLOSED LOW WHICH WOULD GIVE THE REGION A DECENT SHOT AT PRECIP. UNTIL THE MORE RECENT 12Z RUN THE ECMWF SHOWED A SIMILAR BUT SLOWER SOLUTION. THE 12Z ECMWF KEEPS THE LOW CLOSED OFF ALONG THE US/CA BORDER WITH AN OPEN TROF IN THE SOUTHCENTRAL CONUS. THOUGH THE TROF REMAINS OPEN IT ALMOST MATCHES THE SPEED OF THE GFS ALMOST PERFECTLY. FOR NOW PRECIP CHANCES HAVE BEEN KEPT IN THE FORECAST STARTING LATE SATURDAY WITH HIGH POPS EXISTING OVER THE ROLLING PLAINS. THE BIGGER CHALLENGE COMES WITH PRECIP TYPE LATE SUNDAY AFTER A COLD FRONT PUSHES INTO THE REGION PENDING THAT THE LOW IS CLOSED. BOTH MODELS SHOW 850 MB TEMPS REMAIN ABOVE FREEZING BUT NOT BY MUCH. THE 00Z RUN OF THE ECMWF SHOWED 850 MB TEMPS DOWN TO -5C. SNOW WOULD NOT BE OUT OF THE REALM OF POSSIBILITY IF TEMPS CAN COOL DOWN FAST ENOUGH...BUT FOR NOW THE MENTION WILL BE FOR RAIN OR SNOW. REGARDLESS OF PRECIP TEMPERATURES SHOULD BE NOTICEABLY COLDER BEHIND THE FRONT WITH HIGHS AVERAGING IN THE MID 40S ON MONDAY WITH LOWS DIPPING BACK DOWN BELOW FREEZING FOR MUCH OF THE AREA. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 35 61 41 60 38 / 0 0 10 10 10 TULIA 35 61 42 59 42 / 0 0 10 10 10 PLAINVIEW 35 61 43 59 41 / 0 0 10 10 10 LEVELLAND 38 61 42 59 43 / 0 0 10 10 10 LUBBOCK 39 63 44 59 43 / 0 0 10 10 10 DENVER CITY 43 61 44 59 43 / 0 0 10 10 10 BROWNFIELD 40 61 44 59 45 / 0 0 10 10 10 CHILDRESS 39 66 43 62 47 / 0 0 10 10 10 SPUR 38 64 44 62 48 / 0 0 10 10 10 ASPERMONT 39 66 45 63 50 / 0 0 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07/23/07
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
336 PM CST SUN DEC 7 2014 .SHORT TERM... (Tonight and Monday) The primary focus in the short term will be ongoing rain chances and the return of fog and low visibilities to the forecast area. Light rain showers will migrate east across the forecast area this afternoon. Rainfall totals will remain low, though any precip will assist in keeping the area moist. Inherited PoP grids are adequate for expected weather this afternoon though new model data is pessimistic about tonight and early tomorrow morning. Thus removed mention of PoPs for that time period. NAM, GFS, and RAP model soundings are optimistic about bringing fog back into West Central Texas tonight. At this time, fog is expected to form sometime after midnight and lift shortly after 9 A.M. tomorrow. Areas of fog will likely be more widespread tonight than they were early this morning, extending from south of Interstate 10 and north of Throckmorton. Light winds tonight and added moisture from today`s rain showers promote this solution. Cloud cover this morning kept temperatures from climbing too quickly this morning resulting in afternoon high near normal. Tonight, however, added moisture and low cloud ceilings will insulate the forecast area and keep temperatures 5-7 degrees above normal. Clearing skies tomorrow afternoon will allow for unseasonably warm temperatures with highs mainly in the mid 60s. 18 .LONG TERM... (Monday night through Sunday) Shortwave ridging aloft Monday night will shift east as we head into Tuesday as a weak shortwave trough moves across the Rockies. This feature will move southeast into Plains by Wednesday morning, slowing as it absorbs southern stream wave over the southern Plains. Moisture will be slow to increase ahead of this system, with dewpoints likely remaining in the lower 40s throughout the day Tuesday. We should see ample high clouds, keeping temperatures in the mid 60s Tuesday afternoon, but low clouds are not expected until Tuesday night. This increasing moisture and cloud cover will limit diurnal ranges and keep min temps generally in the mid/upper 40s for Wednesday morning. There are considerable differences in the midweek 500 mb pattern between the GFS, ECMWF, and GEM, yielding low confidence in any particular solution at this time. The GFS is the fastest of the 12z runs with the onset of isentropic ascent across West Central TX with the ECMWF following suit 6-12 hours later. Given what has been as progressive flow as of late, siding with a bit faster solution seems reasonable. This broad, isentropic ascent will result in an abundance of cloud cover Wednesday and Thursday with a persistent southerly fetch at low-levels, maintaining modest moisture advection. Rainfall is expected to be rather light, similar to what we`re seeing today across the area, with amounts typically under 1/10". The cloud cover and light precipitation will also keep temps around 60 degrees, with the potential to be a few degrees cooler if light rain showers are a bit more widespread than anticipated. Low rain chances will hang around through Thursday night as weak perturbations move through the flow aloft. By Friday, we should see improving conditions as the shortwave trough moves east and shortwave ridging returns. This should allow a modest warm-up with dry weather anticipated heading into the weekend. We are watching a rather strong trough setting course for the west coast late in the week. The medium range models are moving this trough across the Rockies over the weekend, backing winds aloft to the southwest. The associated lee cyclogenesis will enhance low-level winds and should promote increasing surface moisture. The timing of this feature`s effects for West Central TX is certainly up in the air at this time, but there is pretty decent model consensus that a closed mid-level cyclone develops and moves east-southeast into West TX around Sunday. This pattern bears watching as it could provide the area with a good opportunity for measurable rainfall. As usual, there is plenty of time for things to change, but we`ll be watching! Johnson && .PRELIMINARY POINT TEMPS/POPS... Abilene 40 66 43 66 45 / 5 0 0 0 10 San Angelo 40 66 43 66 45 / 5 0 0 5 20 Junction 41 68 41 66 45 / 10 5 0 0 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 18/25
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1145 PM CST SAT DEC 6 2014 .AVIATION... LIFR CONDITIONS SHOULD CONTINUE AT KCDS MOST IF THE NIGHT...THEN SLOWLY IMPROVE SUNDAY MORNING. KLBB AND KPVW ARE LIKELY TO EXPERIENCE A PERIOD OF MVFR AND POSSIBLY IFR CONDITIONS DUE TO LOW STRATUS AND FOG...WITH SOME UNCERTAINTY WITH TIMING THE RETURN TO VFR CONDITIONS LATE IN THE MORNING OR AROUND MIDDAY SUNDAY. IN ADDITION...-SHRA WILL BE POSSIBLE AT ALL TERMINALS...MORE LIKELY AT KLBB BETWEEN ROUGHLY 08 UTC AND 16 UTC. SURFACE WINDS WILL REMAIN LIGHT THROUGH THE PERIOD AND SLOWLY SWING AROUND FROM E-SE TO S-SW. && .PREV DISCUSSION... /ISSUED 1045 PM CST SAT DEC 6 2014/ UPDATE... QUICK UPDATE TO ADD A DENSE FOG ADVISORY TO THE FAR SOUTHEAST TX PANHANDLE AND THE ROLLING PLAINS. THICK FOG HAS MADE IT TO MEMPHIS AND DICKENS AND SHORT-TERM GUIDANCE SHOWS IT SLOWLY EXPANDING WESTWARD THROUGH EARLY SUNDAY MORNING. IN FACT THE ADVISORY MAY NEED EVENTUALLY NEED TO BE EXPANDED FARTHER WEST IF THE HRRR IS CORRECT. PREV DISCUSSION... /ISSUED 542 PM CST SAT DEC 6 2014/ AVIATION... ALL TERMINALS SHOULD BE VFR AT 00 UTC. HOWEVER...LOW STRATUS AND FOG ARE PRODUCING IFR CONDITIONS JUST TO THE EAST OF KCDS. THIS AREA IS EXPECTED TO EXPAND WESTWARD THIS EVENING...DROPPING KCDS OUT OF VFR BY 01 UTC OR SO AND LIKELY IMPACTING KLBB AND KPVW AFTER ABOUT 08 UTC. CEILING AND VSBY REDUCTIONS MAY PERSIST THROUGH EARLY SUNDAY MORNING. IN ADDITION...AS A STORM SYSTEM PASSES ACROSS THE REGION...SCATTERED -SHRA ARE POSSIBLE AT ALL TERMINALS BETWEEN ABOUT 06 UTC AND 16 UTC...WITH KLBB MOST LIKELY TO SEE A RAIN SHOWER. SURFACE WINDS WILL REMAIN LIGHT THROUGH THE PERIOD AND SLOWLY SWING AROUND FROM A EASTERLY TO SOUTHERLY FETCH. PREV DISCUSSION... /ISSUED 343 PM CST SAT DEC 6 2014/ SHORT TERM... THE BACK EDGE OF A SURFACE HIGH WAS SLOWLY EXITING THE WESTERN SOUTH PLAINS THIS AFTERNOON AHEAD OF STEADY PRESSURE FALLS IN NEW MEXICO. THESE PRESSURE DEFICITS WERE IN RESPONSE TO A TROUGH APPROACHING FROM THE DESERT SOUTHWEST WHICH SHOULD REACH THE FORECAST AREA BY SUNDAY MORNING. SATELLITE PRESENTATION OF THIS WAVE APPEARS RESPECTABLE...HOWEVER REGIONAL METARS AND RADAR MOSAICS IN AZ AND NM ARE NOT VERY INSPIRING FOR MEASURABLE PRECIP CHANCES IN THE NEXT 24 HOURS. WORSE...THIS WAVE IS SHOWN TO DAMPEN AS IT LIFTS NORTHEAST. DESPITE THIS DECAYING TREND...A GRADUAL UPTICK IN MOIST ISENTROPIC LIFT WILL DEVELOP TONIGHT AND PULL SLIGHTLY HIGHER THETA-E AIR NORTHWARD. AT THE SAME TIME HOWEVER THIS MOIST LAYER WILL BE ON THE THIN SIDE. EVEN WITH TOP-DOWN MOISTENING SHOWN BY THE MODELS BY SUN MORNING... A NOTABLE DRY LAYER CENTERED AROUND 750MB MAY ROB MUCH OF THIS MOISTURE AND YIELD ONLY SPRINKLES. CHOSE TO KEEP 20 POPS ACROSS THE SOUTHERN HALF OF THE CWA FROM 12-18Z WHERE A BRIEF WINDOW FOR SPOTTY LIGHT SHOWERS LOOKS MOST FAVORABLE...BUT PRIOR TO THIS POPS WERE SCALED BACK CONSIDERABLY IN COVERAGE DUE TO DELAYED MOISTENING. OTHERWISE...THE AXIS OF THIS POSITIVELY TILTED TROUGH WILL BE DEPARTING THE CWA THROUGH THE AFTERNOON AHEAD OF AMPLE MID-LEVEL DRYING. TEMPS WERE NUDGED UP OVERNIGHT IN LIGHT OF INCREASING CLOUDS AND LL MOISTURE. ON A RELATED NOTE...THE ADVECTION FOG THREAT OVERNIGHT APPEARS LESS IN COVERAGE AND DURATION...BUT REMAINS VALID. LONG TERM... IN THE EXTENDED...A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST WILL EXTEND CLEAR INTO ALASKA TO WEST OF NOME AS LOW NEAR 47N150W REMAINS A SEMI-PERMANENT FEATURE FOR THE NEXT WEEK. WAVES OF ENERGY WILL SHOOT ACROSS THE PACIFIC NORTHWEST THOUGH A NOTABLE WEAKNESS IN THE RIDGE WILL APPROACH OUR AREA LATE TUESDAY. THIS SYSTEM WILL BE QUITE WEAK AND ONLY SLOWLY DRIFT EAST OF US BY THURSDAY AS A RESPECTABLE AMPLITUDE TROUGH MOVES ACROSS THE DESERT SOUTHWEST FOR NEXT WEEKEND. MODELS CONTINUE TO ADVERTISE RAIN CHANCES THAT ARE HIGHER THAN WHAT WOULD BE EXPECTED GIVEN THE WEAK NATURE OF THE SYSTEM INTO TUESDAY AND WEDNESDAY WITH DRY CONDITIONS EXPECTED THROUGH THE END OF THE WORK WEEK. OVERALL...A FAIRLY TRANQUIL WEEK IS AHEAD WITH TEMPS GENERALLY ABOVE SEASONAL NORMS. MANY QUESTIONS REMAIN REGARDING NEXT WEEKEND/S SYSTEM WHETHER IT MAY BE A RAIN OR A WIND EVENT. CLIMATOLOGY WOULD TEND TO SUGGEST WIND. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 37 58 32 61 34 / 10 10 0 0 0 TULIA 39 58 32 62 34 / 10 10 0 0 0 PLAINVIEW 39 58 33 62 34 / 10 10 0 0 0 LEVELLAND 39 58 34 62 37 / 20 20 0 0 0 LUBBOCK 41 58 34 62 37 / 10 20 0 0 0 DENVER CITY 37 55 34 61 37 / 20 20 0 0 0 BROWNFIELD 40 56 35 61 37 / 10 20 0 0 0 CHILDRESS 41 56 36 65 38 / 10 10 0 0 0 SPUR 42 56 37 64 38 / 10 20 0 0 0 ASPERMONT 43 55 39 64 39 / 10 20 10 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR THE FOLLOWING ZONES: TXZ024>026-030>032-036>038-043-044. && $$ 33
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1045 PM CST SAT DEC 6 2014 .UPDATE... QUICK UPDATE TO ADD A DENSE FOG ADVISORY TO THE FAR SOUTHEAST TX PANHANDLE AND THE ROLLING PLAINS. THICK FOG HAS MADE IT TO MEMPHIS AND DICKENS AND SHORT-TERM GUIDANCE SHOWS IT SLOWLY EXPANDING WESTWARD THROUGH EARLY SUNDAY MORNING. IN FACT THE ADVISORY MAY NEED EVENTUALLY NEED TO BE EXPANDED FARTHER WEST IF THE HRRR IS CORRECT. && .PREV DISCUSSION... /ISSUED 542 PM CST SAT DEC 6 2014/ AVIATION... ALL TERMINALS SHOULD BE VFR AT 00 UTC. HOWEVER...LOW STRATUS AND FOG ARE PRODUCING IFR CONDITIONS JUST TO THE EAST OF KCDS. THIS AREA IS EXPECTED TO EXPAND WESTWARD THIS EVENING...DROPPING KCDS OUT OF VFR BY 01 UTC OR SO AND LIKELY IMPACTING KLBB AND KPVW AFTER ABOUT 08 UTC. CEILING AND VSBY REDUCTIONS MAY PERSIST THROUGH EARLY SUNDAY MORNING. IN ADDITION...AS A STORM SYSTEM PASSES ACROSS THE REGION...SCATTERED -SHRA ARE POSSIBLE AT ALL TERMINALS BETWEEN ABOUT 06 UTC AND 16 UTC...WITH KLBB MOST LIKELY TO SEE A RAIN SHOWER. SURFACE WINDS WILL REMAIN LIGHT THROUGH THE PERIOD AND SLOWLY SWING AROUND FROM A EASTERLY TO SOUTHERLY FETCH. PREV DISCUSSION... /ISSUED 343 PM CST SAT DEC 6 2014/ SHORT TERM... THE BACK EDGE OF A SURFACE HIGH WAS SLOWLY EXITING THE WESTERN SOUTH PLAINS THIS AFTERNOON AHEAD OF STEADY PRESSURE FALLS IN NEW MEXICO. THESE PRESSURE DEFICITS WERE IN RESPONSE TO A TROUGH APPROACHING FROM THE DESERT SOUTHWEST WHICH SHOULD REACH THE FORECAST AREA BY SUNDAY MORNING. SATELLITE PRESENTATION OF THIS WAVE APPEARS RESPECTABLE...HOWEVER REGIONAL METARS AND RADAR MOSAICS IN AZ AND NM ARE NOT VERY INSPIRING FOR MEASURABLE PRECIP CHANCES IN THE NEXT 24 HOURS. WORSE...THIS WAVE IS SHOWN TO DAMPEN AS IT LIFTS NORTHEAST. DESPITE THIS DECAYING TREND...A GRADUAL UPTICK IN MOIST ISENTROPIC LIFT WILL DEVELOP TONIGHT AND PULL SLIGHTLY HIGHER THETA-E AIR NORTHWARD. AT THE SAME TIME HOWEVER THIS MOIST LAYER WILL BE ON THE THIN SIDE. EVEN WITH TOP-DOWN MOISTENING SHOWN BY THE MODELS BY SUN MORNING... A NOTABLE DRY LAYER CENTERED AROUND 750MB MAY ROB MUCH OF THIS MOISTURE AND YIELD ONLY SPRINKLES. CHOSE TO KEEP 20 POPS ACROSS THE SOUTHERN HALF OF THE CWA FROM 12-18Z WHERE A BRIEF WINDOW FOR SPOTTY LIGHT SHOWERS LOOKS MOST FAVORABLE...BUT PRIOR TO THIS POPS WERE SCALED BACK CONSIDERABLY IN COVERAGE DUE TO DELAYED MOISTENING. OTHERWISE...THE AXIS OF THIS POSITIVELY TILTED TROUGH WILL BE DEPARTING THE CWA THROUGH THE AFTERNOON AHEAD OF AMPLE MID-LEVEL DRYING. TEMPS WERE NUDGED UP OVERNIGHT IN LIGHT OF INCREASING CLOUDS AND LL MOISTURE. ON A RELATED NOTE...THE ADVECTION FOG THREAT OVERNIGHT APPEARS LESS IN COVERAGE AND DURATION...BUT REMAINS VALID. LONG TERM... IN THE EXTENDED...A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST WILL EXTEND CLEAR INTO ALASKA TO WEST OF NOME AS LOW NEAR 47N150W REMAINS A SEMI-PERMANENT FEATURE FOR THE NEXT WEEK. WAVES OF ENERGY WILL SHOOT ACROSS THE PACIFIC NORTHWEST THOUGH A NOTABLE WEAKNESS IN THE RIDGE WILL APPROACH OUR AREA LATE TUESDAY. THIS SYSTEM WILL BE QUITE WEAK AND ONLY SLOWLY DRIFT EAST OF US BY THURSDAY AS A RESPECTABLE AMPLITUDE TROUGH MOVES ACROSS THE DESERT SOUTHWEST FOR NEXT WEEKEND. MODELS CONTINUE TO ADVERTISE RAIN CHANCES THAT ARE HIGHER THAN WHAT WOULD BE EXPECTED GIVEN THE WEAK NATURE OF THE SYSTEM INTO TUESDAY AND WEDNESDAY WITH DRY CONDITIONS EXPECTED THROUGH THE END OF THE WORK WEEK. OVERALL...A FAIRLY TRANQUIL WEEK IS AHEAD WITH TEMPS GENERALLY ABOVE SEASONAL NORMS. MANY QUESTIONS REMAIN REGARDING NEXT WEEKEND/S SYSTEM WHETHER IT MAY BE A RAIN OR A WIND EVENT. CLIMATOLOGY WOULD TEND TO SUGGEST WIND. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 37 58 32 61 34 / 10 10 0 0 0 TULIA 39 58 32 62 34 / 10 10 0 0 0 PLAINVIEW 39 58 33 62 34 / 10 10 0 0 0 LEVELLAND 39 58 34 62 37 / 20 20 0 0 0 LUBBOCK 41 58 34 62 37 / 10 20 0 0 0 DENVER CITY 37 55 34 61 37 / 20 20 0 0 0 BROWNFIELD 40 56 35 61 37 / 10 20 0 0 0 CHILDRESS 41 56 36 65 38 / 10 10 0 0 0 SPUR 42 56 37 64 38 / 10 20 0 0 0 ASPERMONT 43 55 39 64 39 / 10 20 10 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR THE FOLLOWING ZONES: TXZ024>026-030>032-036>038-043-044. && $$ 33/23
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 PM CST SUN DEC 7 2014 .TONIGHT AND MONDAY...CONFIDENCE - MEDIUM. MAIN 500 MB SHORTWAVE TROUGH IS WELL DEFINED OVER NORTH DAKOTA...AND IS EXPECTED TO SHIFT EASTWARD INTO NORTHERN MINNESOTA TONIGHT...THEN TO THE NORTHEAST ON MONDAY. A VORTICITY MAXIMUM TO THE SOUTH OF THE MAIN SHORTWAVE TROUGH WILL SLIDE EAST TOWARD THE AREA LATER TONIGHT...THEN THROUGH THE AREA MONDAY MORNING. ANOTHER STRONGER VORTICITY MAXIMUM WILL SHIFT SOUTHEAST THROUGH THE AREA DURING THE AFTERNOON. MODEST WARM AIR ADVECTION AREA...COMBINED WITH MODEST LOW TO MID LEVEL FRONTOGENESIS RESPONSE BAND...IS EXPECTED TO COMBINE WITH THE LEAD VORTICITY MAXIMUM TO PRODUCE A 4 TO 5 HOUR WINDOW OF MODERATE TO STRONG UPWARD VERTICAL MOTION WEST TO EAST ACROSS THE AREA. THE TIMING FOR THIS BAND WILL BE AROUND MIDNIGHT IN THE FAR WESTERN COUNTIES...TO AROUND 09Z TO 10Z MONDAY FOR THE LAKESHORE COUNTIES. AREA FORECAST SOUNDINGS ARE SHOWING SOME DIFFERENCES. THE GFS/ECMWF ARE THE MOST CONSISTENT AND CONTINUE TO SUPPORT A PERIOD OF LIGHT SNOW AND LIGHT SLEET MIX ACROSS THE AREA. THE NAM IS MILDER WITH ITS WARM LAYER ABOVE THE SURFACE AND INDICATES SOME LIGHT FREEZING RAIN MIXING IN AT TIMES. THE RAP SOUNDINGS ALSO LEAN IN THIS DIRECTION SOMEWHAT. LEANED TOWARD THE MORE CONSISTENT GFS/ECMWF AND WENT WITH PREVAILING LIGHT SNOW AND LIGHT SLEET LATER TONIGHT INTO EARLY MONDAY. KEPT CHANCES FOR LIGHT FREEZING RAIN IN THE SOUTH...IN CASE MILDER MODELS ARE CORRECT. SHOULD SEE SNOW AND SLEET ACCUMULATIONS AROUND 1.0 INCH IN MOST AREAS...A BIT MORE IN THE FAR NORTHERN COUNTIES AND LESS NEAR LAKE MICHIGAN. HOURLY RATES OF 0.1 TO 0.3 INCHES PER HOUR ARE EXPECTED. GIVEN TIMING DURING THE MORNING COMMUTE ON MONDAY...CONSIDERED A WINTER WEATHER ADVISORY. AFTER COLLABORATION WITH NEIGHBORING OFFICES...HELD OFF AND ISSUED A SPECIAL WEATHER STATEMENT. EVENING SHIFT WILL NEED TO CONSIDER ONE...ESPECIALLY IF GFS LEANS TOWARD THE NAM/RAP WITH LIGHT FREEZING RAIN POTENTIAL. STRONGER 500 MB VORTICITY MAXIMUM DURING THE AFTERNOON WILL CONTINUE TO BRING CHANCES FOR LIGHT RAIN AND LIGHT SNOW MONDAY. PERHAPS THE PRECIPITATION WILL BECOME MORE LIGHT RAIN LATER IN THE DAY...AS SURFACE TEMPERATURES WARM ABOVE FREEZING. LOWS TONIGHT SHOULD BE IN THE UPPER 20S TO LOWER 30S...WITH MIDDLE TO UPPER 30S ON MONDAY. .MONDAY NIGHT THROUGH WEDNESDAY...CONFIDENCE - MEDIUM. LINGERING WEAK LIFT AND LOW LEVEL RH MAY RESULT IN SOME LINGERING FLURRIES OR DRIZZLE MONDAY EVENING BEFORE LOWER LEVELS FURTHER DRY. WL CONTINUE LOW POPS FOR MEASUREABLE -RA/-SN IN THE EVE FOR THE FAR EAST...CLOSER TO DEPARTING MID-LEVEL SHORT WAVE TROUGH. OTHERWISE...SHORT WAVE RIDGING MOVES ACROSS WI LATER TUE INTO WED. LOW LEVEL WINDS TURN MORE NORTHEAST FOR A TIME TUE/TUE NGT WITH DELTA-T WITH DELTA-T INCREASING TO AROUND 6-7C. LOW LEVELS SLOWLY WARM AT THIS TIME...AND SHORT TERM GUIDANCE IN DISAGREEMENT ON AMOUNT OF VEERING OF WINDS DURING THIS PERIOD. HENCE WL HOLD OFF ON ANY -SN OR FLURRY MENTION AT THIS TIME. TEMPERATURES REMAINING CLOSE TO SEASONAL NORMAL THIS PERIOD. .WEDNESDAY NIGHT THROUGH SUNDAY...CONFIDENCE - MEDIUM. A QUIET PERIOD EXPECTED THROUGH SATURDAY WITH SOME MODERATION IN TEMPERATURES. 00Z ECMWF AND ECMWF MEAN TRENDING TOWARD SLOWER NORTHWARD MOVEMENT OF LARGE LOW PRESSURE SYSTEM AFFECTING EAST COAST EARLY IN THE PERIOD. IN FACT...APPEARS SYSTEM NOW TRENDING TOWARD CUTOFF STATUS AND WILL SLOWLY WEAKEN OVER THE EAST COAST THRU THE WEEKEND. OTHER MEDIUM RANGE GUIDANCE INCLUDING GFS AND GEM TRENDING IN THIS DIRECTION. AS A RESULT...UPSTREAM LONG WAVE RIDGE OVER CENTRAL CONUS INCLUDING WRN GTLAKES WL PERSIST A LITTLE LONGER...AT LEAST THRU SAT. RIDGE LOOKS TO FINALLY SUCCUMB TO INTENSIFYING SHORT WAVE FROM THE WRN CONUS LATE IN THE WEEKEND INTO MONDAY. HENCE BEST THREAT FOR LIQUID PRECIP SUN NGT INTO MON. 925H TEMPS WARM FROM AROUND -4C ON WED TO FLUCTUATE BTWN 2 AND 6C FROM THU THRU SUN. LACK OF SNOW COVER HELPS...HOWEVER PENDING CLOUDS...DAYTIME TEMPS LIKELY TO PEAK MOSTLY IN THE 40S...BEGINNING FRI. ONE MINOR CONCERN EARLY IN THE PERIOD IS WHETHER ANY LAKE EFFECT WOULD BE POSSIBLE AS CENTER OF HIGH PRESSURE PASSES BY TO THE NORTH. ECMWF SHOWING MORE FAVORABLE ONSHORE FLOW IN THE LOW LEVELS WED NGT BUT THEN BECOMES MORE NLY THU AND EVENTUALLY BACKS TO THE WEST TO SOUTHWEST. DELTA-T LOOKS MARGINAL WED NGT SO WL HOLD OFF ON ANY LAKE EFFECT PRECIP AT THIS TIME. && .AVIATION/00Z TAFS/... QUIET WEATHER CONTINUES INTO THIS EVENING...WITH MIDDLE TO HIGH CLOUDS AND SOUTHEAST WINDS. LIGHT SNOW AND LIGHT SLEET WILL MOVE THROUGH TAF SITES LATER TONIGHT INTO EARLY MONDAY MORNING. MADISON SHOULD SEE THE PRECIPITATION BETWEEN 07Z AND 08Z MONDAY...AND THE EASTERN TAF SITES BETWEEN 09Z AND 10Z MONDAY. VISIBILITIES BELOW ALTERNATE MINIMUMS ARE EXPECTED...WITH CEILINGS IN THE MVFR/IFR CATEGORY. EXPECTING ABOUT A 4 TO 5 HOUR TIME PERIOD OF THIS LIGHT SNOW AND LIGHT SLEET MIX...ENDING BY 14Z TO 15Z MONDAY. 1.0 TO 1.5 INCHES ARE FORECAST AT MADISON...WITH 0.5 TO 1.0 INCH AT THE EASTERN SITES. HOURLY RATES OF SNOW AND SLEET ACCUMULATION SHOULD RANGE FROM ABOUT 0.1 TO 0.3 INCHES. SOME LIGHT FREEZING RAIN MAY MIX IN AS WELL...BUT LEFT OUT OF TAFS FOR NOW DUE TO LOWER CONFIDENCE. AFTER THE MIX OF PRECIPITATION MOVES OUT OF THE AREA...THERE MAY BE SOME LIGHT RAIN AND LIGHT SNOW LINGERING THROUGH THE REST OF THE DAY. MVFR VISIBILITIES WITH CEILINGS BELOW ALTERNATE MINIMUMS ARE ANTICIPATED. ANY ACCUMULATIONS LATER ON MONDAY WOULD BE A DUSTING AT BEST. WINDS WILL GRADUALLY VEER FROM SOUTHWEST TO WEST. && .MARINE... TIGHTENING PRESSURE GRADIENT AHEAD OF APPROACHING SFC LOW PRESSURE TROF WILL RESULT IN CONTINUED GUSTY SOUTHEAST WINDS TURNING TO THE SOUTH TONIGHT INTO MONDAY. A LULL IN THE WINDS IS EXPECTED LATER MON INTO MON EVE AS THE SFC TROF MOVES ACROSS THE NEAR SHORE WATERS. EXPECT THE WINDS TO INCREASE ONCE AGAIN FROM THE NORTHWEST BEHIND THE TROF MON NGT AS SOMEWHAT COLDER AIR SWEEPS ACROSS LAKE MICHIGAN AND HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST. HENCE STATUS QUO ON ONGOING SMALL CRAFT ADVY THRU TUE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 6 PM CST TUESDAY FOR LMZ643>646. $$ TONIGHT AND MONDAY/AVIATION...WOOD MONDAY NIGHT THROUGH SUNDAY/MARINE...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
221 PM CST SUN DEC 7 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 221 PM CST SUN DEC 7 2014 WATER VAPOR SATELLITE IMAGERY SHOWING THE LEAD SHORT WAVE TROUGH WAS WORKING ACROSS WESTERN MINNESOTA AND IOWA EARLY THIS AFTERNOON. THE 07.12Z NAM AND GFS ALONG WITH THE 07.15Z RAP IN PRETTY GOOD AGREEMENT IN SHOWING THIS WAVE BREAKING INTO TWO PARTS AS THE AFTERNOON CONTINUES. THE NORTHERN PART OF THE WAVE EITHER DISSIPATES AHEAD OF THE UPPER LEVEL LOW OVER NORTH DAKOTA OR MOVES NORTHEAST TOWARD LAKE SUPERIOR. THE SOUTHERN PART OF THE WAVE IS EXPECTED TO CONTINUE MOVING EAST/SOUTHEAST BUT GOING SOUTH OF THE AREA ACROSS IOWA AND MISSOURI. AS THIS OCCURS...THE LINE OF RADAR RETURNS TO THE WEST OF THE AREA IS EXPECTED TO GRADUALLY WEAKEN AND IS NOT EXPECTED TO PRODUCE MUCH IF ANY PRECIPITATION...BUT SHOULD HELP TO MOISTEN THE COLUMN. IT NOW APPEARS AS IF THE MAIN PRECIPITATION BAND WILL OCCUR AHEAD OF THE SECOND AND STRONGER SHORT WAVE TROUGH ROTATING AROUND THE UPPER LEVEL LOW. THE WAVE WILL COME ACROSS CENTRAL AND NORTHERN MINNESOTA THIS EVENING AND NORTHERN MINNESOTA OVERNIGHT. THIS WAVE SHOULD PRODUCE MODERATE PV ADVECTION IN THE 500-300 MB LAYER AS IT COMES ACROSS THE REGION WITH WEAK QG CONVERGENCE IN THE 1000-300 MB LAYER. ISENTROPICALLY...THERE SHOULD BE 2 TO 3 UBAR/S OF UP GLIDE OCCURRING ON THE 290K SURFACE. THIS SHOULD BE ENOUGH FORCING TO PRODUCE A BAND OF LIGHT PRECIPITATION AHEAD OF THE SHORT WAVE TROUGH AND WILL CONTINUE TO SHOW A BAND OF 60 TO 90 PERCENT CHANCES WORKING WEST TO EAST ACROSS THE AREA TONIGHT. THE BIG CONCERN WITH THIS PRECIPITATION IS WHAT TYPE IT WILL BE. THE BUFKIT SOUNDINGS FROM BOTH THE NAM AND GFS CONTINUE TO SHOW A WARM LAYER ALOFT WILL BE IN PLACE AS THE PRECIPITATION COMES IN TO PRODUCE EITHER TOTAL OR PARTIAL MELTING FOR EITHER SOME FREEZING DRIZZLE OR SLEET. EVAPORATIVE COOLING SHOULD WIPE OUT THIS WARM LAYER WITHIN A COUPLE OF HOURS FOR A TRANSITION OVER TO LIGHT SNOW. HOWEVER...THIS LIKELY WILL NOT CONTINUE VERY LONG BEFORE THERE IS A LOSS OF ICE REINTRODUCING THE CHANCE FOR SOME FREEZING DRIZZLE. THE ICE IN THE CLOUDS SHOULD MAINTAIN ITSELF LONGER OVER THE NORTHERN SECTIONS TO KEEP THE PRECIPITATION AS LIGHT SNOW UNTIL THE OVERNIGHT HOURS BEFORE POSSIBLY MIXING WITH SOME FREEZING DRIZZLE. FORTUNATELY...WITH ONLY LIGHT PRECIPITATION EXPECTED...ONLY SOME VERY LIGHT ICING MAY OCCUR. THE OTHER THING THAT MAY MITIGATE THE ICING IS THE POTENTIAL FOR SURFACE TEMPERATURES TO RISE AND REACH FREEZING OR ABOVE FOR AREAS SOUTHWEST OF INTERSTATE 94. AT THIS POINT...DO NOT PLAN TO ISSUE A WINTER WEATHER ADVISORY...BUT WILL SEND OUT A SPECIAL WEATHER STATEMENT TO HEIGHTEN THE AWARENESS ALONG WITH A SHORT TERM GRAPHIC CAST IMAGE. A SECONDARY SHORT WAVE TROUGH WILL ROTATE AROUND THE UPPER LEVEL LOW MONDAY AND PRODUCE WEAK PV ADVECTION IN THE 500-300 MB LAYER. SOME WEAK QG CONVERGENCE SHOULD OCCUR IN THE 850-500 MB LAYER ALONG WITH ABOUT 1 UBAR/S OF UP GLIDE ON THE 290K ISENTROPIC SURFACE. THIS SHOULD BE ENOUGH TO MAINTAIN A CHANCE FOR SOME LIGHT PRECIPITATION...ESPECIALLY IN THE INTERSTATE 94 CORRIDOR AND WILL START THE DAY WITH 60 TO 70 PERCENT CHANCES GRADUALLY DECREASING THROUGH THE DAY AS THE UPPER LEVEL LOW AND SHORT WAVE TROUGH MOVE AWAY FROM THE AREA. STILL A CONCERN AS TO WHETHER THERE WILL BE ICE IN THE CLOUDS AND WILL START WITH A LIGHT SNOW/FREEZING DRIZZLE GOING TO EITHER FREEZING DRIZZLE OR DRIZZLE BASED ON SURFACE TEMPERATURES. SOUTHWEST OF THIS AREA...THE LOW LEVEL LAPSE RATES WILL BE INCREASING WITH VALUES OF 7 TO 10 KM/C BELOW 850 MB BY AFTERNOON. THIS LOW LEVEL LAYER LOOKS TO BE SATURATED AND WITH THE CYCLONIC FLOW...THERE SHOULD BE ENOUGH FORCING TO RING OUT SOME LIGHT PRECIPITATION. FOR NOW...HAVE STAYED WITH FLURRIES AS THE COLD AIR ADVECTION INCREASES...BUT CONCERNED THIS LAYER MAY NOT BE COLD ENOUGH FOR ICE TO BE IN THE CLOUDS. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 221 PM CST SUN DEC 7 2014 RELATIVELY QUIET PERIOD EXPECTED AS HIGH PRESSURE SETS UP OVER THE UPPER MIDWEST AND THEN REMAINS IN PLACE THROUGH THE END OF THE WEEK. BOTH THE 07.12Z ECMWF AND GFS SHOW THE RIDGING WILL BEGIN TO MOVE EAST OF THE REGION OVER THE UP COMING WEEKEND...BUT IT REMAINS TO BE SEEN HOW FAST THIS WILL OCCUR. THE GFS IS QUICKER TO DO THIS THAN EITHER THE ECMWF OR 07.12Z GEM. THE FASTER GFS THEN ALLOWS A SHORT WAVE TROUGH TO COME OUT OF THE DEVELOPING SOUTHWEST FLOW FOR SOME PRECIPITATION CHANCES SATURDAY NIGHT INTO SUNDAY. WITH TEMPERATURES WARMING IN THE SOUTHWEST FLOW...THE BULK OF ANY PRECIPITATION THAT FALLS MAY JUST BE RAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1148 AM CST SUN DEC 7 2014 STRONG 900 TO 800 MB FRONTOGENESIS IS PRODUCING RADAR ECHOES ALONG THE INTERSTATE 35 CORRIDOR. HOWEVER NOT SEEING ANY PRECIPITATION ASSOCIATED WITH THIS FORCING AT THE MOMENT. DURING THE NEXT 2 TO 3 HOURS THIS WILL MOVE EAST INTO SOUTHEAST MINNESOTA AND NORTHEAST IOWA AND WEAKEN. MEANWHILE THE PRECIPITATION WILL HAVE TO WAIT FOR THE SHORT WAVE MOVING OUT OF THE DAKOTAS. THIS WAVE WILL MOVE THROUGH SOUTHEAST MINNESOTA AND NORTHEAST IOWA PRIMARILY THIS EVENING...AND WESTERN WISCONSIN OVERNIGHT. PRECIPITATION WILL START OUT AS A SNOW OR SLEET...AND THEN TRANSITION POSSIBLY TO A DRIZZLE OR FREEZING DRIZZLE DEPENDING ON THE TEMPERATURES. ONE CONCERN DURING THE LATTER IS THAT THE LIFT IS MAINLY ABOVE THE SATURATED LOW LAYERS...SO WILL IT DEVELOP OR NOT. CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE DRIZZLE/FREEZING DRIZZLE IN THE TAFS AT THIS TIME. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
451 AM EST TUE DEC 9 2014 .SYNOPSIS... A SIGNIFICANT COASTAL STORM WILL IMPACT THE REGION TODAY WITH WINTRY PRECIPITATION AND HEAVY RAIN...ALONG WITH STRONG TO DAMAGING WINDS. LEFTOVER LIGHT SNOW AND RAIN SHOWERS WILL PERSIST WEDNESDAY AND THURSDAY. SLOW IMPROVEMENT IS EXPECTED FRI INTO THIS WEEKEND. && .NEAR TERM /TODAY THROUGH 6 AM WEDNESDAY/... */ HIGHLIGHTS... - WINTRY PRECIPITATION TYPES ERODING WITH TIME TO THE N/W - SNOW / ICE ACCUMULATIONS REMAIN AT WINTER-WX-ADVISORY LEVELS - HEAVY RAIN OF 2-3 INCHES LENDING TO POSSIBLE FLOODING - STRONG TO DAMAGING E-WINDS YIELDING WIND ADV HEADLINES */ SYNOPTICALLY... PRESENT OFFSHORE LOW OFF THE MID-ATLANTIC CONUS BECOMES USURPED BY AN AMPLIFYING TROUGH DIGGING THROUGH THE E-CONUS. ACROSS A REGION OF FAVORABLE BAROCLINICITY / ATTENDANT DYNAMICS / STRONG FORCING AND DEEP-LAYER ASCENT YIELDS A RAPIDLY DEEPENING AREA OF LOW PRESSURE OFF THE DELMARVA PENINSULA THIS MORNING LIFTING N INTO S NEW ENGLAND BY EVENING. THE LOW BECOMES STALLED AND CUTOFF FROM THE MEAN FLOW UP AGAINST HIGH PRESSURE ON NEARLY ALL SIDES AS WE GO INTO THE WEEK. */ HEAVY RAIN AND FLOODING... INTERROGATING DEEPER...AS THE LOW DEEPENS...EXPECT DECENT LOW-LEVEL TROWALING OF THE WARM-CONVEYOR-BELT BENEATH THE RRQ/LFQ OF ATTENDANT UPPER-LEVEL JET AXES. COMBINATION OF THE CONVERGENT LEADING NOSE OF ISENTROPIC UPSLOPE LENDING TO THE TIGHTENING OF THE THERMAL GRADIENT AGAINST NEIGHBORING HIGH PRESSURE YIELDING STRONG FRONTOGENETICAL FORCING IN A REGION OF MINOR -EPV INSTABILITY BENEATH AFOREMENTIONED DEEP-LAYER ASCENT LIKELY TO RESULT IN A ROUGHLY W-E BANDING SETUP OF HIGHER WSR-88D RETURNS WITHIN A WIDESPREAD COMMA-SHAPED PRECIP FIELD ALONG THE N-PERIPHERY OF THE H85 LOW WITH THE FRONT-END THUMP OF PRECIP ANTICIPATED AROUND MIDDAY AND PERSISTING INTO EARLY EVENING. WHEW...DEEP BREATH. FEEL THE HRRR SIMULATED RADAR TRENDS ARE SHOWING THIS QUITE WELL. WILL EXPAND THE FLOOD WATCH TO INCLUDE CAPE COD AND NANTUCKET. WITH HEIGHT OF THE E/NE-WINDS AND HEAVY RAIN CONCURRENT WITH TIMING OF HIGH TIDE CENTERED AROUND 1 PM BELIEVE SURGE ALONG WITH BUILDING WAVE HEIGHTS /SEE THE MARINE DISCUSSION BELOW FOR MORE DETAILS/ WILL RESULT IN POOR-DRAINAGE ISSUES FOR COASTAL COMMUNITIES. ANTICIPATE DRAINS TO BACK-UP BECOMING OVER-TOPPED RESULTING IN SUSCEPTIBLE LOW- LYING AND POOR-DRAINAGE AREAS TO BECOME FLOODED. AM ALSO CONCERNED FOR EVEN THOSE COMMUNITIES WITHIN THE COASTAL PLAIN IN VICINITY OF RIVERS THAT ARE INFLUENCED BY THE TIDE /I.E. TAUNTON RIVER...LOWER CONNECTICUT/. COULD ALSO SEE SOME EXACERBATED FLOOD ISSUES FOR THESE AREAS. OTHERWISE REMAINDER OF THE FLOOD WATCH REMAINS IN PLACE. PWATS OF 1.25-INCHES FORECAST /ROUGHLY +2 STANDARD DEVIATIONS ABOVE-NORMAL/ AND FORECAST RAINFALL AMOUNTS OF 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS ANTICIPATED. GROUND IS PRETTY SOLID /IMPERVIOUS/ THUS EXPECT MOST OF THE RAINFALL TO BECOME RUNOFF. MAJORITY OF MAINSTEM RIVERS OVER THE INTERIOR SHOULD BE ABLE TO HANDLE THE RAIN...SO CONCERNS LIE IN THE REALM OF URBAN / POOR DRAINAGE FLOODING...ESPECIALLY IF DRAINS ARE STILL LEAF-CLOGGED. BIGGEST AREA OF CONCERN IS WITHIN THE METRO-AREA CORRIDORS...ESPECIALLY BOSTON-PROVIDENCE. MAY NEED TO EXPAND THE WATCH ACROSS N-CENTRAL AND NW MA PENDING THE TIMING AT WHICH WINTRY-PRECIP TYPES TRANSITION TO RAIN. */ WINTRY PRECIPITATION... OUTCOMES DEPENDENT ON THERMAL FIELDS ALOFT...WHERE AROUND H925-H85 BY MORNING CONDITIONS ARE WARMING CONSIDERABLY UP AGAINST COLDER AIR AND HIGH PRESSURE SITUATED N/W. A SW-NE FREEZING LINE AROUND NW-CT INTO S NH INITIALLY MODIFIES NW AS THE LOW DEEPENS RESULTING IN THE INCREASE OF THE SE WARM-MOIST-CONVEYOR-BELT. EXPECT THICKNESSES TO GRADUALLY RISE DURING THE HEIGHT OF THE EVENT INTO EVENING. AT THE SURFACE...AREAS BELOW FREEZING ERODE WITH INCREASING ONSHORE E/NE-WINDS DURING THE MORNING /MORE ON THAT LATER/. UNCERTAINTY CONTINUES WITH 09.0Z HIGH-RES MODELS DIFFERING IN TIMING OF EROSION. AS MENTIONED IN PRIOR DISCUSSIONS...FOR AREAS THAT ARE WITHIN OR ON THE CUSP OF BELOW-FREEZING TEMPERATURES BY 1-2C...LINGERING AN HOUR OR TWO MORE OR LESS CAN MAKE ALL THE DIFFERENCE WITH REGARDS TO WINTER-WEATHER HEAD-LINES. H975-925 AGEOSTROPHIC FLOW IS NOTABLY PERSISTENT AND STRONG OUT OF THE W AS THE LOW INTENSIFIES TOWARDS S NEW ENGLAND. BUT NOT MUCH OF A N-COMPONENT NOR FROM ARCTIC-SOURCE REGIONS...SO BELIEVE THIS WILL DO LITTLE TO MAINTAIN / PERSIST COLD AIR OVER THE REGION AGAINST STRONG ONSHORE E-FLOW. WILL GO CLOSE TO THE NEAR-TERM HIGH-RES GUIDANCE WHILE INCORPORATING THE WRF-NMM WITH REGARDS TO THERMAL FIELDS...WHICH ARE HANDLING THE SURFACE TEMPERATURES DECENTLY. PREFERENCE TO THE 09.0Z ECMWF IS ALSO GIVEN ESPECIALLY WHEN EVALUATING H100-H85 THICKNESSES. ONLY WRF-ARW AND RAP LEAN ON THE WARM SIDE OF THE GUIDANCE OVER ALL OTHERS. ALSO WILL GO WITH A TOP-DOWN APPROACH TOWARDS PRECIPITATION-TYPE THAT INCORPORATES THE INCREASING MOISTURE FROM THE S WITHIN OR ABOVE THE DENDRITIC GROWTH ZONE REGION. SO OVERALL...EXPECTING THE GRADUAL EROSION OF THE COASTAL-FRONT WITH INCREASING ONSHORE E-FLOW. PUSH OF WARMER AIR ALOFT AHEAD OF THE DEEPENING LOW WILL RESULT IN PRECIP-TYPE TRANSITION FAIRLY QUICKLY TO A SLEET / FREEZING RAIN MIX. THIS HAS SUBSEQUENTLY BUMPED DOWN SNOWFALL AMOUNTS RESULTING IN A RANGE OF 2-4 INCHES ACROSS NW MA. MOST OF THE REGION CHANGES OVER TO RAIN BY LATE MORNING INTO MIDDAY WITH ONLY THE HIGHER ELEVATIONS OF THE BERKSHIRES CONTINUALLY UNDER THE THREAT OF FREEZING RAIN. HAVE DROPPED WINTER-STORM WATCHES AND REPLACED WITH WINTER WEATHER ADVISORIES. HAVE TRIMMED THE EASTERN-EXTENT WITH EROSION OF THE COASTAL FRONT AND THE SURGANCE OF WARMER AIR ONSHORE. AGAIN...THE THERMAL FIELDS DISCUSSION ABOVE GIVE AN INDICATION OF PREFERRED MODEL GUIDANCE. SHOULD SEE WINTER WEATHER HEADLINES DROP MAINLY AROUND THE MIDDAY HOURS. MID-LEVEL DRY-SLOT WRAPPING INTO A DEVELOPING OCCLUSION BEGINNING TUESDAY EVENING SHOULD RESULT IN A LULL OF PRECIPITATION AS WE GO INTO WEDNESDAY MORNING. */ STRONG TO DAMAGING WINDS... NOTING E-WINDS 1-2 KFT AGL WILL BE AROUND 55 MPH AROUND THE MIDDAY INTO AFTERNOON HOURS...THE PRESENCE OF WARMER AIR ALOFT LENDING TO AN INVERSION JUST ABOVE THE SURFACE MAKES IT DIFFICULT TO CONSIDER A HIGH WIND WARNING. THIS DESPITE WARMER AIR WIGGLING ITS WAY UP FROM THE S AT THE SURFACE...AND A WARMER OCEAN /THOUGH NOW AROUND THE LOW- 50S/. BOUNDARY-LAYER MIXING WILL BE LIMITED. HIGH-END WIND ADVISORY CRITERIA IS EXPECTED...BUT DO NOT EXPECT WIDESPREAD GUSTS EXCEEDING HIGH WIND WARNING CRITERIA. THUS WENT WITH THE WIND ADVISORY. COULD PRECIPITATION-DRAG PROCESSES BRING FASTER MOMENTUM TO THE SURFACE? YES...IT IS QUITE POSSIBLE...EVEN IF THUNDERSTORMS ARE IN THE MIX WHICH IS IN THE FORECAST FOR THE FAR SE-WATERS ADJACENT TO THE CAPE AND ISLANDS. HAVE GONE WITH THE HEADLINES THAT CONVEY THE HIGHEST CONFIDENCE. */ COASTAL FLOODING... SEE TIDES/COASTAL FLOODING SECTION BELOW FOR DETAILS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * LINGERING RAIN/SNOW SHOWERS INTO THU AS CLOSED LOW SLOWLY EXITS * IMPROVING CONDITIONS FRI INTO THIS WEEKEND DECENT MODEL AGREEMENT BOTH AT THE SURFACE AND ALOFT WEDNESDAY INTO FRIDAY. MORE SIGNIFICANT DIFFERENCES ARISE FRIDAY NIGHT INTO EARLY NEXT WEEK. AS SUCH...FAVORED A CONSENSUS BLEND TO UPDATE THIS PORTION OF THE FORECAST. THIS WAS TO SMOOTH OVER THE MINOR DIFFERENCES INTO FRIDAY...AS WELL AS MINIMIZE ERROR AFTER THAT POINT. CLOSED LOW WILL BE SLOW TO EXIT NEW ENGLAND...AND 09/00Z GUIDANCE MODELS CONTINUE TO SHOW A DEEP UPPER LOW OVER NORTHERN NEW ENGLAND FINALLY MOVING OUT TO SEA SATURDAY NIGHT. ONE OF THE PRIMARY ISSUES WITH THIS FORECAST WILL BE THE AMOUNT OF MOISTURE AVAILABLE. THINKING THERE WILL BE ENOUGH TO KEEP SKIES MOSTLY CLOUD INTO FRIDAY NIGHT. HOW MUCH WILL BE LEFTOVER TO US IN GENERATING PRECIPITATION IS ANOTHER MATTER. CONTINUED THE PREVIOUS FORECAST OF A GRADUAL DRYING OUT PROCESS FRIDAY INTO SATURDAY. HIGH PRESSURE SHOULD BE IN CONTROL OF OUR WEATHER SUNDAY INTO MONDAY. NEAR OR SLIGHTLY BELOW NORMAL TEMPERATURES EXPECTED THROUGH THIS PERIOD. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH WEDNESDAY MORNING/... 4Z UPDATE... TOWARDS 12Z... MIX OF MVFR-IFR CIGS WITH IFR VSBYS WITH ANY -SN. OTHERWISE RUNWAYS BECOMING ICY WITH FZDZ. INCREASING NE-WINDS WITH GUSTS UP TO 25 KTS ALONG THE IMMEDIATE COASTLINES BY MORNING. TUESDAY... STRONG E WINDS AND HEAVY RAIN INTO TUESDAY EVENING WITH WIDESPREAD MVFR/IFR AND AREAS OF LIFR...ESPECIALLY ACROSS HIGHER TERRAIN AND NEAR COAST. EAST WINDS 40 KT OR GREATER LIKELY ACROSS EASTERN MA/S COASTAL RI. LOW RISK OF 50 KT OVER OUTER CAPE COD AND NANTUCKET...POSSIBLE OUTER CAPE ANN. CONDITIONS SHOULD BEGIN TO IMPROVE TOWARD EVENING. KBOS TERMINAL...MODERATE CONFIDENCE. LOWERED CIGS / VSBYS WITH -SN LIKELY MIXING WITH OR OVER TO FZDZ. SHOULD SEE CHANGEOVER TO RAIN TOWARDS THE MORNING HOURS THOUGH TIMING IS NOT ABSOLUTELY CERTAIN. COULD STILL SEE IMPACTS DURING THE MORNING PUSH. KBDL TERMINAL...MODERATE CONFIDENCE. FZDZ LIKELY TO DEVELOP OVER THE NEXT HR OR TWO. WILL SEE A WINTRY MIX AS WE GO INTO THE MORNING HOURS WITH THE POSSIBILITY OF SNOW AND SLEET BEFORE CHANGING OVER TO RAIN THROUGH THE MORNING. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. MVFR/IFR IN SCATTERED RAIN OR SNOW SHOWERS. FRIDAY...MODERATE CONFIDENCE. MVFR IN ISOLATED RAIN/SNOW SHOWERS. SATURDAY...MODERATE CONFIDENCE. VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE. 11 PM UPDATE...NO CHANGES MADE AT THIS TIME. PREVIOUS DISCUSSION... STORM WARNINGS IN EFFECT FOR OUTER S COASTAL WATERS WHERE CONFIDENCE IS HIGHEST IN REACHING CRITERIA. MAINTAINING STORM WATCHES ELSEWHERE DUE TO UNCERTAINTY...EXCEPT ISSUING GALE WARNINGS FOR BOSTON HARBOR AND NARRAGANSETT BAY. TONIGHT...EXPECT E-NE WIND TO INCREASE AS COASTAL LOW MOVES NORTH OVERNIGHT. GALE FORCE GUSTS LIKELY RETURNING TO SOUTHERN WATERS AFTER MIDNIGHT. SEAS ALSO BUILD...AS HIGH AS 8-10 FT ON THE OUTER WATERS BY DAYBREAK. TUESDAY...DEEPENING LOW PRES MOVES UP THE EASTERN SEABOARD TOWARD LONG ISLAND DURING THE DAY. EXPECT WIDESPREAD E GALES WITH AREAS OF STORM FORCE GUSTS ON THE SOUTHERN OUTER WATERS TUE AFTERNOON AND EVENING. SEAS RAPIDLY BUILD TO 15-20 FT EASTERN MA WATERS. HEAVY RAIN LOWERS VSBY...ESPECIALLY LATE TUE MORNING THROUGH THE AFTERNOON. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. SMALL CRAFT ADVISORIES WILL LIKELY NEED TO CONTINUE THROUGH THURSDAY NIGHT ACROSS THE OCEAN-EXPOSED COASTAL WATERS...MAINLY DUE TO ROUGH SEAS. THERE COULD ALSO BE SOME WEST/SOUTHWEST GUSTS UP TO 25 KT AS WELL. ALSO SHOULD SEE LEFTOVER SCATTERED RAIN/SNOW SHOWERS. FRIDAY INTO SATURDAY...MODERATE CONFIDENCE. SLOW IMPROVEMENT CONTINUES WITH DIMINISHING WINDS AND SEAS. SEAS SHOULD FINALLY DROP BELOW 5 FT ACROSS ALL BUT THE OUTERMOST COASTAL WATERS FRI EVENING...THEN REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS ACROSS ALL WATERS SATURDAY. && .HYDROLOGY... STORM TOTAL RAINFALL OF 2 TO 3 INCHES EXPECTED ACROSS MUCH OF REGION THROUGH WED MORNING. MAIN CONCERN IS FOR SIGNIFICANT URBAN FLOODING...ESPECIALLY NEAR I-95 CORRIDOR FROM PROVIDENCE TO BOSTON WHICH INCLUDES MORE FLOOD PRONE AREAS OF NEW BEDFORD...FALL RIVER AND PEABODY. LATEST NERFC GUIDANCE BRINGS LOWER CT RIVER AT MIDDLE HADDAM TO ACTION STAGE...WHICH IS PRIMARILY BASED ON SURGE OF 2 FT INTO LOWER CT RIVER. WE MAY ALSO SEE SIMILAR SURGE ALONG PAWCATUCK RIVER NEAR WESTERLY RI WHICH COULD BRING RISES SLIGHTLY HIGHER THAN CURRENTLY FORECAST. && .TIDES/COASTAL FLOODING... WE WENT AHEAD AND ISSUED A COASTAL FLOOD ADVISORY FOR THE EASTERN MA COAST FOR THE TUESDAY MIDDAY HIGH TIDE CYCLE. APPEARS WINDS/SEAS WILL BE RAMPING UP AS THE TUE MIDDAY HIGH TIDE APPROACHES. THIS A RESULT OF INTENSIFYING LOW PRESSURE OVER THE MID ATLANTIC LIFTING TOWARDS SOUTHERN NEW ENGLAND. AS THE PRESSURE GRADIENT INCREASES SHOULD SEE NORTHEAST WIND GUSTS OF 40 TO 50 MPH DEVELOP TOWARDS THE TUE MIDDAY HIGH TIDE. STORM SURGE GUIDANCE APPEARS SLOW TO CATCH ON...SO INCREASED IT SOME AND EXPECT A 2+ FOOT STORM SURGE DURING THE HIGH TIDE. THIS SHOULD BE ENOUGH TO RESULT IN MINOR COASTAL FLOODING ALONG WITH SOME MINOR BEACH EROSION ACROSS THE EASTERN MA COAST. SEAS MAY EVENTUALLY COME UP TO 20 FEET ACROSS OUR EASTERN WATERS...BUT THIS SHOULD BE SEVERAL HOURS AFTER THE HIGH TIDE. THAT IS WHY WE EXPECT MAINLY MINOR COASTAL FLOODING...AS OPPOSED TO A MORE SIGNIFICANT EVENT. WERE NOT REALLY CONCERNED ABOUT THE LATE TUESDAY NIGHT OR WEDNESDAY HIGH TIDES CAUSING PROBLEMS. PRESSURE GRADIENT/WINDS WEAKEN AND ASTRONOMICAL TIDES CONTINUE TO LOWER. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ002>004. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ002>004. MA...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM EST THIS EVENING FOR MAZ007-014>016-019>024. FLOOD WATCH THROUGH LATE TONIGHT FOR MAZ005>007-011>022-024. COASTAL FLOOD ADVISORY FROM 11 AM THIS MORNING TO 3 PM EST THIS AFTERNOON FOR MAZ007-015-016-019-022-024. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR MAZ005-006-011-012. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ003-004-009-010-026. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MAZ013. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ002-008. RI...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM EST THIS EVENING FOR RIZ006>008. FLOOD WATCH THROUGH LATE TONIGHT FOR RIZ001>007. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR RIZ001- 003. MARINE...GALE WARNING FROM 7 AM THIS MORNING TO 10 PM EST THIS EVENING FOR ANZ231>234-251. GALE WARNING FROM 10 AM THIS MORNING TO 10 PM EST THIS EVENING FOR ANZ230. GALE WARNING FROM 7 AM THIS MORNING TO 7 PM EST THIS EVENING FOR ANZ236. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ235-237. STORM WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ250-254>256. && $$ SYNOPSIS...BELK/SIPPRELL NEAR TERM...SIPPRELL SHORT TERM...SIPPRELL LONG TERM...BELK AVIATION...BELK/SIPPRELL MARINE...BELK/SIPPRELL HYDROLOGY...STAFF TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS ALBANY NY
420 AM EST TUE DEC 9 2014 .SYNOPSIS... A SLOW MOVING COASTAL STORM WILL BRING A VARIETY OF WINTER WEATHER TO THE REGION FOR TODAY INTO TONIGHT. WHILE MANY VALLEY AND EASTERN AREAS WILL SEE A TRANSITION OF A WINTRY MIX TO RAIN...THE PRECIPITATION WILL BE MAINLY SNOW ACROSS THE CATSKILLS AND ADIRONDACKS...WITH A MODERATE TO HEAVY ACCUMULATION POSSIBLE IN THESE HIGH TERRAIN AREAS. WITH THE STORM REMAINING CLOSE TO THE REGION...SOME ADDITIONAL RAIN AND SNOW WILL OCCUR WEDNESDAY INTO THURSDAY AS WELL...WITH SOME ADDITIONAL SNOW ACCUMULATION POSSIBLE. && .NEAR TERM /THROUGH TONIGHT/... AS OF 420 AM EST...A DEVELOPING COASTAL LOW IS CURRENTLY SITUATED OFF THE COAST OF CAPE HATTERAS. THIS LOW IS STARTING TO LIFT NORTHWARD...AND 3 HR PRESSURE FALLS OF AROUND 5 MBS ARE OCCURRING OFF THE DELMARVA. AN UPPER LEVEL SHORTWAVE TROUGH IS DIVING OUT OF THE GREAT LAKES/MIDWEST REGION...AND THIS UPPER LEVEL SHORTWAVE WILL BE CAPTURING THE SFC WAVE...AND CAUSING IT TO BASICALLY STALL JUST OFF THE NEW JERSEY SHORE TODAY. A STRONG LOW LEVEL JET IN EXCESS OF 50 KTS IS ADVECTING PLENTY OF MOISTURE AND WARM AIR ALOFT INTO THE REGION. THE LATEST REGIONAL MOSAIC RADAR SHOWS A STEADY BATCH OF MODERATE TO HEAVY PRECIP OVER NJ...AND THIS PRECIP IS QUICKLY ADVANCING NORTHWARD INTO OUR AREA. IN ADVANCE OF THIS STEADY PRECIP...SOME LIGHT FREEZING DRIZZLE/MIST IS OCCURRING...AS THE LOW LEVELS ARE STARTING TO MOISTEN UP IN ADVANCE OF THE MAIN SLUG OF PRECIP. MODEL SOUNDINGS SUGGEST PRECIP WILL BEGIN AS A WINTRY MIX FOR THE MID HUDSON VALLEY AND NW CT...AS A WARM NOSE BETWEEN 850 AND 925 HPA WILL BE IN PLACE. AS THIS PRECIP ADVANCES FURTHER NORTH...IT LOOKS TO BE SNOW ACROSS THE CATSKILLS...BUT WILL PROBABLY BE A SNOW/SLEET MIX AS IT REACHES THE CAPITAL REGION AND TACONICS. THERE WILL BE A SHARP CUTOFF BETWEEN SNOW VS. WINTRY MIX VS. RAIN. THE 3KM HRRR SHOWS THAT SNOW SHOULD ACCUMULATE ACROSS THE CATSKILLS/HELDERBERGS AND POINTS WESTWARD THIS MORNING...BUT ANY SNOW/SLEET ACCUMULATION WILL BE LIMITED TO JUST A FEW HOURS FOR THE HUDSON VALLEY...TACONICS AND NW CT...BEFORE PRECIP CHANGES TO A PLAIN RAIN. SFC TEMPS LOOK TO NUDGE JUST ABOVE FREEZING BY THE MID MORNING FOR THE MID HUDSON VALLEY...AND LATE MORNING HOURS IN THE CAPITAL REGION. FURTHER NORTH...THE PRECIP WILL EXPAND INTO THE MOHAWK VALLEY AND ADIRONDACKS BY THE EARLY AFTN HOURS. PRECIP LOOKS TO BE MAINLY SNOW FOR THE MOHAWK VALLEY/ADIRONDACKS...BUT WILL LIKELY MIX FOR THE SARATOGA/GLENS FALLS AREA. EVEN UP THERE...A CHANGEOVER TO RAIN LOOKS TO OCCUR DURING THE AFTN HOURS...AS WARM AIR...BOTH AT THE SFC AND ALOFT...WILL BE MOVING INTO THE AREA. FURTHER EAST...THE PRECIP WILL CHANGE TO A WINTRY MIX FOR SOUTHERN VT/BERKSHIRES AS WELL...EVEN ACROSS THE HIGH TERRAIN...AS WARM AIR ALOFT OF NEARLY 3 DEGREES C MOVES OVER THE AREA FROM THE EAST. SOME SNOW/SLEET WILL LIKELY ACCUMULATE BEFORE THE CHANGEOVER...BUT THE CHANGEOVER WILL PREVENT WARNING LEVEL SNOW FROM OCCURRING. SOME STRONG WINDS ARE POSSIBLE ACROSS THE SRN GREENS...TACONICS AND BERKSHIRES...WITH SOME GUSTS OF 25-40 MPH POSSIBLE. THE FULL BRUNT OF THE LOW LEVEL JET DOESN/T LOOK LIKE IT WILL BE ABLE TO MIX DOWN DUE TO STABLE LOW LEVELS...BUT SOME GUSTS ARE STILL POSSIBLE...ESP IN AREAS THAT CHANNEL E-SE FLOW WELL. WE WILL CONTINUE TO MENTION THIS WIND THREAT IN OUR HWO STATEMENT. AS THE BEST ISENTROPIC LIFT SHIFTS NORTH AND EAST OF THE REGION THIS EVENING...STEADY PRECIP WILL START TO SHUT OFF ACROSS OUR AREA. THE SFC LOW WILL BE MEANDERING OVER THE NYC/LONG ISLAND AREA...AND THE 500 HPA LOW WILL BECOME CUTOFF OVER THE DELMARVA AREA. AS A RESULT...SOME ADDITIONAL ON AND OFF PRECIP WILL OCCUR OVERNIGHT DUE TO THE PVA/CYCLONIC FLOW...BUT IT WILL NOT BE STEADY OR HEAVY. THERE WILL STILL BE SOME ABOVE FREEZING TEMPS ALOFT...AND THERE MAY EVEN BE A LACK OF ICE NUCLEI IN THE CLOUDS...AS THE BEST DEEPER AND COLDER CLOUD TOPS SHIFT AWAY FROM THE AREA. BECAUSE OF THIS...SOME FREEZING RAIN/DRIZZLE MAY OCCUR...ALONG WITH SOME BURSTS OF SNOW/RAIN/SLEET AS WELL. TEMPS LOOK TO HOLD STEADY IN THE LOW TO MIDDLE 30S ACROSS THE ENTIRE REGION. BECAUSE OF ALL OF THIS...WINTER STORM WARNINGS WERE NOT ISSUED OUTSIDE THE CATSKILLS/MOHAWK AND SCHOHARIE VALLEY/ADIRONDACKS BECAUSE WARNING LEVEL SNOWFALL /7 INCHES IN 12 HOURS OR 9 INCHES IN 24 HOURS/ IS NOT EXPECTED. STILL...A WINTRY MIX...EVEN THOUGH IT WILL GO OVER TO RAIN...WILL MAKE FOR HAZARDOUS TRAVEL IN THE CAPITAL REGION/GLENS FALLS AND SARATOGA AREAS/BERKSHIRES/SOUTHERN VT/...AND THIS IS WHY THE WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THESE LOCATIONS. SNOW ACCUMULATION IN THESE AREAS WILL VARY BASED ON ELEVATION...WITH JUST A FEW INCHES IN THE VALLEY AREAS...AND 2 TO 6 INCHES ACROSS THE HIGH TERRAIN. JUST A COATING TO AN INCH OF SNOW/SLEET/ICE IS EXPECTED FOR THE POUGHKEEPSIE/KINGSTON AREA AND NW CT...AS PRECIP SHOULD QUICKLY GO OVER TO RAIN THERE THIS MORNING. HOWEVER...THE FLOOD WATCH REMAINS IN EFFECT...AS HEAVY RAINFALL MAY LEAD TO SOME FLOOD CONCERNS. SEE OUR HYDRO DISCUSSION FOR MORE DETAILS ON THIS THREAT. MEANWHILE... 6 TO 12 INCHES LOOK TO ACCUMULATE IN THE CATSKILLS...HELDERBERGS...MOHAWK AND SCHOHARIE VALLEYS...AND ADIRONDACKS. EVEN IN THESE AREAS...SOME SLEET/FREEZING RAIN IS POSSIBLE AT TIMES...AND VALLEYS WILL BE ON THE LOWER END OF THE RANGE...WITH THE HIGHEST AMOUNTS IN THE HIGH PEAKS OF THE CATSKILLS IN THE GREENE COUNTY...AND IN THE HIGHEST PEAKS OF THE SRN ADIRONDACKS OF WARREN COUNTY. THE SNOW WILL BE RATHER WET...AND THIS MAY MAKE FOR SOME POWER OUTAGES/DOWNED TREE LIMBS...ESP CONSIDERING THAT STRONG NORTH WINDS ARE EXPECTED. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... A NEARLY VERTICALLY STACKED LOW OVER NEW ENGLAND WILL KEEP OUR WEATHER UNSETTLED THROUGH THE SHORT TERM PERIOD. WHILE DIFFICULT TO ASCERTAIN WHAT WAVE/S/ WILL TRIGGER ADDITIONAL PRECIPITATION...MOISTURE WILL WRAP IN OFF THE ATLANTIC TO KEEP THE HIGH PROBABILITIES IN THE FORECAST. THE BEST LOCATIONS WILL BE ALONG THE I90 CORRIDOR AND POINTS NORTHWARD. AS FOR THERMAL PROFILES...WE WILL BE COOLING DOWN THE COLUMN WHERE MOST OF THIS PRECIPITATION WILL BE IN THE FORM OF SNOW. THERE WILL BE SOME RAIN/SNOW MIXTURE INTO THE VALLEY LOCATIONS DURING THE LATE MORNING INTO THE MID AFTERNOON HOURS. THE BEST CHANCE FOR ADDITIONAL ACCUMULATIONS WILL BE INTO THE HIGHER TERRAIN. AS FOR THE SPECIFIC... WEDNESDAY...LATEST TRENDS IN THE MODEL GUIDANCE POINT TOWARD A MORE SIGNIFICANT SURGE OF MOISTURE OFF THE ATLANTIC AS THE MAIN UPPER LOW REMAINS JUST OFF THE JERSEY SHORE. MOISTURE ADVECTION AND HIGHER THETA-E /TROWAL/ BACK INTO PORTIONS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND. SPECIFIC HUMIDITIES REMAIN RATHER HIGH OF 3-4 G/KG SO WHERE IT DOES SNOW...WE COULD SEE ADDITIONAL ACCUMULATIONS OF SNOW. PER THE LATEST NCEP MODEL SUITE AND 00Z ECMWF...THIS SEEMS TO LINE UP FOR OUR NORTHERN HALF OF THE CWFA. ADDITIONAL FINE TUNING WILL TAKE PLACE AS PER CSTAR RESEARCH...THESE UPPER LOWS ARE QUITE PROBLEMATIC WITH PROVIDING SPECIFICS WHERE THE HEAVIER QPF WILL FALL. THURSDAY...AS THE LOW FILLS AND FURTHER REDUCES THE BAROCLINICITY...THE PRECIP INTENSITY AND AMOUNTS WILL DIMINISH. SO ADDITIONAL ACCUMULATIONS SHOULD BE RATHER LIGHT THROUGH THE DAY WITH JUST A COUPLE MORE INCHES OF SNOW...MAINLY INTO THE TERRAIN. THURSDAY NIGHT...WHILE THE UPPER LOW BEGINS TO SLOWLY MIGRATE EASTWARD...ITS INFLUENCES WILL CONTINUE ACROSS THE REGION. THIS WILL RESULT IN CHC-SCT SNOW PROBABILITIES WITH ADDITIONAL LIGHT ACCUMULATIONS THROUGHOUT THE REGION AS TEMPERATURES WILL BE BELOW FREEZING. WE WILL USE A BLENDED APPROACH TO THE MOS TEMPERATURES AS THEY WERE FAIRLY CLOSE IN VALUES. && .LONG TERM /FRIDAY THROUGH TUESDAY/... WE MAY STILL BE DEALING WITH A CUT-OFF UPPER LEVEL LOW FOR FRIDAY INTO SATURDAY...BUT THE SYSTEM WILL HAVE LOST ITS BAROCLINICITY BY THEN RESULTING IN MAINLY SCATTERED SNOW SHOWERS. THE BEST CHANCE FOR ANY LIGHT MEASURABLE SNOWFALL WILL BE OVER THE HIGHER TERRAIN WEST AND EAST OF THE HUDSON RIVER VALLEY...AND ESPECIALLY ACROSS THE SOUTHERN ADIRONDACKS. OUR AREA WILL CONTINUE TO BE UNDER THE INFLUENCE OF THE CYCLONIC FLOW ASSOCIATED WITH THIS SYSTEM...ALTHOUGH DRIER AIR WILL GRADUALLY WORK IN FROM THE WEST...ESPECIALLY ON SATURDAY AS WE SHOULD BE ON THE WESTERN PERIPHERY OF THE CIRCULATION. SO WILL CONTINUE TO MENTION SLIGHT CHANCE TO LOW CHC POPS FOR SNOW SHOWERS FRIDAY AND FRIDAY NIGHT...DECREASING TO SLIGHT CHANCE IN THE VALLEYS FOR SATURDAY. THERE WILL CONTINUE TO BE A SOMEWHAT BETTER CHANCE FOR A PASSING SNOW SHOWER OVER THE HIGHER TERRAIN BOTH FRIDAY AND SATURDAY WITH THE NORTHWEST CYCLONIC FLOW PERSISTING. IT LOOKS LIKE DRIER WEATHER WILL FINALLY PREVAIL FOR LATE SATURDAY INTO SUNDAY...ALTHOUGH THE DEGREE OF CLOUD COVER WILL DEPEND ON HOW QUICKLY THE CUT-OFF LOW MOVES OUT TO SEA. THE ECMWF IS RATHER SLOW WITH THE DEPARTURE OF THE CUT-OFF...LINGERING CYCLONIC FLOW UNTIL SUNDAY...WHILE THE GFS HAS AN UPPER LEVEL RIDGE BUILDING IN BY LATE SATURDAY. AGAIN...THIS WILL HAVE IMPLICATIONS ON CLOUD COVER BUT WE ARE EXPECTING PRECIP-FREE CONDITIONS ON SUNDAY. DESPITE RISING UPPER LEVEL HEIGHTS/TEMPS...SURFACE TEMPS ARE ONLY EXPECTED TO BE SLIGHTLY ABOVE NORMAL DUE TO EXPECTED SHALLOW MIXING THIS TIME OF YEAR. TRANQUIL WEATHER LOOKS TO CONTINUE INTO MONDAY...WITH HIGH PRESSURE AT THE SURFACE AND ALOFT FIRMLY ENTRENCHED OVER THE REGION WITH GOOD AGREEMENT BETWEEN THE ECMWF/GFS. ANOTHER SYSTEM MAY APPROACH FROM THE WEST FOR MON NT AND TUE. WILL ADD SLIGHT CHC POPS...AS THERE IS CONSIDERABLE UNCERTAINTY FOR EARLY NEXT WEEK WHETHER A SOUTHERN STREAM SYSTEM PHASES WITH THE NORTHERN STREAM YET AGAIN...ALBEIT IN A WEAKER STATE THAN THIS WEEK. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... A SIGNIFICANT DEVELOPING COASTAL STORM WITH MULTIPLE PRECIPITATION TYPES WILL IMPACT THE AREA FROM EARLY TUESDAY MORNING INTO WEDNESDAY MORNING. THROUGH 12Z/TUE...A SOLID STRATUS CLOUD DECK HAS ALREADY OVERSPREAD THE TAF SITES. SOME SPOTTY VERY LIGHT PRECIP HAS ALSO DEVELOPED AT KPSF...WHERE IFR CIGS ARE PRESENT. WE EXPECT MAINLY IFR CONDITIONS...MAINLY FOR CIGS...AT KPSF THROUGH 12Z/TUE. ELSEWHERE...EXPECT MAINLY MVFR CONDITIONS...FOR CIGS...TO PERSIST THROUGH 12Z/TUE. SOME SPOTTY LIGHT PRECIPITATION...MAINLY IN THE FORM OF FLURRIES WILL BE POSSIBLE THROUGH 12Z/TUE...ALTHOUGH CAN NOT RULE OUT A BIT OF FREEZING DRIZZLE...ESP BETWEEN 10Z-12Z/TUE. AFTER 12Z/TUE...PRECIP ASSOCIATED WITH COASTAL STORM WILL DEVELOP FROM SOUTH TO NORTH ACROSS THE AREA STARTING SHORTLY 12Z/TUE AT KPOU...TO MID MORNING AT KGFL. CONDITIONS WILL RAPIDLY DETERIORATE TO IFR/LIFR SHORTLY AFTER PRECIP COMMENCES. A WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN IS ANTICIPATED TO START AT KPOU...CHANGING TO RAIN SHORTLY AFTER SUNRISE. SNOW WILL DEVELOP AT KALB/KPSF/KGFL AROUND 12Z-14Z/TUE...THEN QUICKLY CHANGE TO A MIX OF SNOW...SLEET AND FREEZING RAIN AND EVENTUAL RAIN BY NOON AT KALB/KPSF. MODERATE TO HEAVY RAIN WILL THE FALL THROUGH THE AFTERNOON AND EARLY TUE NT...POSSIBLY MIXED WITH SLEET. A WINTRY MIX IS EXPECTED TO PREVAIL WELL INTO THE AFTERNOON AT KGFL BEFORE POSSIBLY CHANGING TO PLAIN RAIN AND/OR SLEET AFTER 23Z/TUE. THE PRECIP TYPE FORECASTS AND TIMING ARE LOW CONFIDENCE AT THIS TIME...AS TEMPERATURE PROFILES IN THE ATMOSPHERE ARE UNCERTAIN. LOW LEVEL COLD AIR MAY SCOUR OUT QUICKER THAN ANTICIPATED OR LINGER LONGER INTO THE AFTERNOON...WHICH WOULD IMPACT WHEN PRECIP TYPE TRANSITIONS OCCUR. WINDS WILL INITIALLY BE N-NE AROUND 5-10 KTS...INCREASING TO 10-15 KTS WITH GUST NEAR OR EXCEEDING 20 KTS TUESDAY AFTERNOON AND NIGHT. OUTLOOK... WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SN. THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... A FLOOD WATCH REMAINS IN EFFECT FOR LITCHFIELD COUNTY CONNECTICUT...DUTCHESS COUNTY NEW YORK AND EASTERN ULSTER COUNTY NEW YORK...FOR THIS MORNING THROUGH TONIGHT. A COASTAL STORM WILL BRING WIDESPREAD PRECIPITATION TO THE AREA FOR TODAY INTO TONIGHT. FOR NORTHWESTERN AND HIGH TERRAIN AREAS...THIS PRECIPITATION WILL FALL PRIMARY AS SNOW OR A WINTRY MIX. MEANWHILE...ACROSS SOUTHERN AND VALLEY AREAS...PRECIP WILL BEGIN AS A PERIOD OF SNOW OR A WINTRY MIX AND TRANSITION TO RAIN. TOTAL LIQUID EQUIVALENT VALUES WILL BE 0.50 OVER THE WESTERN ADIRONDACKS TO NEARLY 2.00 INCHES OVER WESTERN NEW ENGLAND. WITH MUCH OF THIS FALLING AS RAINFALL OVER LITCHFIELD COUNTY AND THE MID HUDSON VALLEY...THERE WILL BE A LOT OF RUNOFF...ESPECIALLY DURING LATE THIS MORNING THROUGH EARLY THIS EVENING WHEN PRECIP WILL BE HEAVIEST. THIS RAINFALL MAY LEAD TO MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS...ESPECIALLY IN AREAS WHERE THE GROUND IS FROZEN. RISES ON RIVERS AND STREAMS ARE LIKELY...AND MINOR FLOODING CANNOT BE RULED OUT ON THE HOUSATONIC RIVER AND IT/S TRIBUTARIES IN NW CT. IN ADDITION...THE STRONG COASTAL LOW IS ALLOWING FOR SOME TIDAL FLOODING ALONG COASTAL AREAS...AND THIS COULD CAUSE A BACKUP OF WATER ON THE HUDSON RIVER. THIS COULD LEAD TO MINOR FLOODING DURING TIMES OF HIGH TIDE IN THE POUGHKEEPSIE AREA THIS AFTERNOON. SOME ADDITIONAL PRECIPITATION...MAINLY IN THE FORM OF SNOW...IS POSSIBLE FOR WEDNESDAY INTO THURSDAY...BUT AMOUNTS ARE EXPECTED TO BE LIGHT IN AREAS THAT SEE THE HEAVIEST LIQUID PRECIP TODAY. THIS SHOULD ALLOW WATER LEVELS TO RECEDE SLOWLY OVER THE NEXT FEW DAYS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ001-013. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ001-013. NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ032-033- 038>040-042-043-047-048-051-058-063-082. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ041- 049-050-052>054-059>061-083-084. FLOOD WATCH THROUGH LATE TONIGHT FOR NYZ064>066. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ064>066. MA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ001- 025. VT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS SHORT TERM...BGM LONG TERM...KL/JPV AVIATION...KL/JPV HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1245 AM EST TUE DEC 9 2014 .SYNOPSIS... AS A SLOW MOVING COASTAL STORM APPROACHES OUR AREA....A LONG DURATION PERIOD OF RAIN AND SNOW...AND POSSIBLY SLEET AND FREEZING RAIN...WILL IMPACT THE REGION THROUGH THURSDAY. THE HEAVIEST PRECIPITATION ASSOCIATED WITH THIS STORM IS EXPECTED THIS MORNING THROUGH THIS EVENING...BUT LINGERING PERIODS OF PRECIPITATION ARE POSSIBLE THROUGH MUCH OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1245 AM EST...LOW STRATUS CLOUDS ARE IN PLACE OVER THE REGION THIS MORNING...WITH THE LOWEST CEILINGS CURRENTLY OVER THE BERKSHIRES. THE LOW LEVELS ARE STARTING TO MOISTEN UP DUE TO A FLOW OFF THE WESTERN ATLANTIC OCEAN. THERE HASN/T BEEN ANY PRECIPITATION IN OUR AREA JUST YET...BUT WITH THE INCREASING MOISTURE IN THE LOWEST LEVELS...SOME FREEZING DRIZZLE IS POSSIBLE FOR SOUTHERN/EASTERN PARTS OF THE AREA. THIS WILL ESPECIALLY BE TRUE FOR SOUTHERN/EASTERN FACING SLOPES OF THE BERKSHIRES AND CATSKILLS...THANKS TO SOME UPSLOPE FLOW. ANY FREEZING DRIZZLE LOOKS FAIRLY SPOTTY...AND MOST AREAS SHOULD STAY DRY. THE 02Z 3KM HRRR SHOWS STEADY PRECIP ASSOCIATED WITH A DEVELOPING COASTAL LOW WILL BE APPROACHING OUR SOUTHERN ZONES BETWEEN 4 AND 6 AM. ACROSS THESE FAR SOUTHERN AREAS...PRECIP LOOKS TO BEGIN AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN. PRECIP WILL QUICKLY START TO TRANSITION MORE TOWARDS THE WINTRY MIX OR EVEN PLAIN RAIN AS LOW LEVEL TEMPS RISE...AND A WARM NOSE STARTS TO DEVELOP AT 925 HPA. TEMPS OVERNIGHT WILL CONTINUE TO BE STEADY IN THE MID TO UPPER 20S...AND MAY EVEN START TO RISE TOWARDS DAYBREAK. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... VERY COMPLEX WINTER STORM WILL HAVE A LARGE IMPACT ON THE REGION THROUGH THE ENTIRE SHORT TERM PERIOD...ESPECIALLY TUESDAY AND EARLY TUESDAY NIGHT. HAVE UPGRADED THE WESTERN AND SOUTHERN ADIRONDACKS...THE MOHAWK AND SCHOHARIE VALLEYS AND THE EASTERN CATSKILLS TO WINTER STORM WARNINGS THROUGH 12Z WEDNESDAY...WITH SNOWFALL AMOUNTS OF 7 TO 14 INCHES...ALONG WITH SOME MIXED PCPN POSSIBLE. THE LOWEST TERRAIN AREAS IN THESE REGIONS MAY NOT EXCEED 7 INCHES OF SNOW DUE TO THE MIXING OF PCPN WITH SLEET...FREEZING RAIN AND RAIN...BUT ON AVERAGE MOST AREAS WILL GET HEAVY SNOW. DUE TO THE EXTREMELY TIGHT GRADIENT IN TEMPERATURES ACROSS THE REGION...AND THE MINOR TEMPERATURE VARIATIONS THAT OCCUR BETWEEN EACH MODEL...AND EVEN BETWEEN DIFFERENT RUNS OF THE SAME MODEL... HAVE DECIDED THAT THERE IS STILL TOO MUCH UNCERTAINTY TO MAKE A DECISION BETWEEN A WARNING OR AN ADVISORY FOR A LARGE PART OF THE FORECAST AREA THAT INCLUDES THE SARATOGA REGION...CAPITAL DISTRICT... THE UPPER PART OF THE MID HUDSON VALLEY...THE TACONICS...SOUTHERN VERMONT AND BERKSHIRE COUNTY. THIS WAS COORDINATED WITH SURROUNDING OFFICES TO THE EAST WHO ALSO KEPT ADJOINING PARTS OF THEIR FORECAST AREAS IN THE WINTER STORM WATCH. FOR NOW HAVE GENERALLY FORECAST 3 TO 10 INCHES IN THE WATCH AREA...WITH MOST AREAS GENERALLY FORECAST TO GET 7 INCHES OR LESS... EXCEPT FOR THE HIGHER TERRAIN OF SOUTHERN VERMONT. MOST OF THE PCPN WILL OCCUR ON TUESDAY...WITH A LARGE DRY SLOT SURGING NORTHWARD AND CUTTING OFF THE STEADIEST AND HEAVIEST PCPN EARLY TUESDAY NIGHT. WITH THE UPPER LOW EVENTUALLY PARKING ITSELF OVER EASTERN NY... OCCASIONAL LIGHT SNOW WILL LIKELY CONTINUE WEDNESDAY AND THURSDAY AS WELL. THERE COULD STILL BE SOME MIXED PCPN WEDNESDAY...BUT ALL SNOW IS EXPECTED WEDNESDAY NIGHT. HIGHS TUESDAY WILL BE 30 TO 40. LOWS TUESDAY NIGHT IN THE MID 20S TO LOWER 30S. HIGHS WEDNESDAY GENERALLY IN THE 30S. LOWS WEDNESDAY NIGHT 20 TO 30. && .LONG TERM /THURSDAY THROUGH MONDAY/... WE WILL STILL BE DEALING WITH A CUT-OFF UPPER LEVEL LOW WHICH WILL BE CENTERED RIGHT OVER THE REGION ON THURSDAY...BUT THE SYSTEM WILL HAVE LOST ITS BAROCLINICITY BY THEN RESULTING IN MAINLY SCATTERED TO LIKELY SNOW SHOWERS. BEST CHANCE FOR ANY LIGHT MEASURABLE SNOWFALL WILL BE OVER THE HIGHER TERRAIN WEST AND EAST OF THE HUDSON RIVER VALLEY. THE CUT-OFF LOW WILL ONLY SLOWLY MEANDER TO THE EAST-NORTHEAST THURSDAY NIGHT INTO FRIDAY...WITH THE CORE MOVING INTO NEW ENGLAND. OUR AREA WILL CONTINUE TO BE UNDER THE INFLUENCE OF THE CYCLONIC FLOW ASSOCIATED WITH THIS SYSTEM...ALTHOUGH DRIER AIR WILL GRADUALLY WORK IN FROM THE WEST...ESPECIALLY ON FRIDAY AS WE WILL BE ON THE WESTERN PERIPHERY OF THE CIRCULATION. SO WILL CONTINUE TO MENTION CHANCE POPS FOR SNOW SHOWERS THURSDAY NIGHT...DECREASING TO SLIGHT CHANCE IN THE VALLEYS FOR FRIDAY. THERE WILL CONTINUE TO BE A SOMEWHAT BETTER CHANCE FOR A PASSING SNOW SHOWER OVER THE HIGHER TERRAIN ON FRIDAY WITH THE NORTHWEST CYCLONIC FLOW PERSISTING. IT LOOKS LIKE DRIER WEATHER WILL FINALLY PREVAIL FOR THE WEEKEND...ALTHOUGH THE DEGREE OF CLOUD COVER WILL DEPEND ON HOW QUICKLY THE CUT-OFF LOW MOVES OUT TO SEA. THE ECMWF IS RATHER SLOW WITH THE DEPARTURE OF THE CUT-OFF LINGERING CYCLONIC FLOW UNTIL SUNDAY...WHILE THE GFS HAS AN UPPER LEVEL RIDGE BUILDING IN BY LATE SATURDAY. AGAIN...THIS WILL HAVE IMPLICATIONS ON CLOUD COVER BUT WE ARE EXPECTING PRECIP-FREE CONDITIONS THROUGH THE UPCOMING WEEKEND. DESPITE RISING UPPER LEVEL HEIGHTS/TEMPS...SURFACE TEMPS ARE ONLY EXPECTED TO BE SLIGHTLY ABOVE NORMAL DUE TO EXPECTED SHALLOW MIXING THIS TIME OF YEAR. TRANQUIL WEATHER LOOKS TO CONTINUE INTO MONDAY...WITH HIGH PRESSURE AT THE SURFACE AND ALOFT FIRMLY ENTRENCHED OVER THE REGION WITH GOOD AGREEMENT BETWEEN THE ECMWF/GFS. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... A SIGNIFICANT DEVELOPING COASTAL STORM WITH MULTIPLE PRECIPITATION TYPES WILL IMPACT THE AREA FROM EARLY TUESDAY MORNING INTO WEDNESDAY MORNING. THROUGH 12Z/TUE...A SOLID STRATUS CLOUD DECK HAS ALREADY OVERSPREAD THE TAF SITES. SOME SPOTTY VERY LIGHT PRECIP HAS ALSO DEVELOPED AT KPSF...WHERE IFR CIGS ARE PRESENT. WE EXPECT MAINLY IFR CONDITIONS...MAINLY FOR CIGS...AT KPSF THROUGH 12Z/TUE. ELSEWHERE...EXPECT MAINLY MVFR CONDITIONS...FOR CIGS...TO PERSIST THROUGH 12Z/TUE. SOME SPOTTY LIGHT PRECIPITATION...MAINLY IN THE FORM OF FLURRIES WILL BE POSSIBLE THROUGH 12Z/TUE...ALTHOUGH CAN NOT RULE OUT A BIT OF FREEZING DRIZZLE...ESP BETWEEN 10Z-12Z/TUE. AFTER 12Z/TUE...PRECIP ASSOCIATED WITH COASTAL STORM WILL DEVELOP FROM SOUTH TO NORTH ACROSS THE AREA STARTING SHORTLY 12Z/TUE AT KPOU...TO MID MORNING AT KGFL. CONDITIONS WILL RAPIDLY DETERIORATE TO IFR/LIFR SHORTLY AFTER PRECIP COMMENCES. A WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN IS ANTICIPATED TO START AT KPOU...CHANGING TO RAIN SHORTLY AFTER SUNRISE. SNOW WILL DEVELOP AT KALB/KPSF/KGFL AROUND 12Z-14Z/TUE...THEN QUICKLY CHANGE TO A MIX OF SNOW...SLEET AND FREEZING RAIN AND EVENTUAL RAIN BY NOON AT KALB/KPSF. MODERATE TO HEAVY RAIN WILL THE FALL THROUGH THE AFTERNOON AND EARLY TUE NT...POSSIBLY MIXED WITH SLEET. A WINTRY MIX IS EXPECTED TO PREVAIL WELL INTO THE AFTERNOON AT KGFL BEFORE POSSIBLY CHANGING TO PLAIN RAIN AND/OR SLEET AFTER 23Z/TUE. THE PRECIP TYPE FORECASTS AND TIMING ARE LOW CONFIDENCE AT THIS TIME...AS TEMPERATURE PROFILES IN THE ATMOSPHERE ARE UNCERTAIN. LOW LEVEL COLD AIR MAY SCOUR OUT QUICKER THAN ANTICIPATED OR LINGER LONGER INTO THE AFTERNOON...WHICH WOULD IMPACT WHEN PRECIP TYPE TRANSITIONS OCCUR. WINDS WILL INITIALLY BE N-NE AROUND 5-10 KTS...INCREASING TO 10-15 KTS WITH GUST NEAR OR EXCEEDING 20 KTS TUESDAY AFTERNOON AND NIGHT. OUTLOOK... TUESDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN...SLEET. WEDNESDAY: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SN. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. FRIDAY NIGHT TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... FLOOD WATCH FOR DUTCHESS AND EASTERN ULSTER COUNTIES ALONG WITH LITCHFIELD COUNTY WHERE 1 TO 2 INCHES OF QPF ARE IN THE FORECAST WITH MAINLY RAIN. A COASTAL STORM WILL BRING WIDESPREAD PRECIPITATION TO THE REGION BEGINNING EARLY IN THE DAY ON TUESDAY AND CONTINUING INTO TUESDAY NIGHT. FOR NORTHWESTERN AND HIGH TERRAIN AREAS...THIS PRECIPITATION WILL FALL PRIMARY AS SNOW OR A WINTRY MIX. MEANWHILE...ACROSS SOUTHERN AND VALLEY AREAS...PRECIP WILL BEGIN AS A PERIOD OF SNOW AND TRANSITION TO A WINTRY MIX AND THEN RAIN. TOTAL LIQUID EQUIVALENT VALUES WILL BE 0.75 OVER THE WESTERN ADIRONDACKS TO ABOUT 2 INCHES OVER WESTERN NEW ENGLAND. WITH MUCH OF THIS FALLING AS RAINFALL OVER LITCHFIELD COUNTY...THERE WILL BE A LOT OF RUNOFF...ESPECIALLY DURING TUESDAY AFTERNOON INTO TUESDAY EVENING WHICH PRECIP WILL BE HEAVIEST. THIS RAINFALL MAY LEAD TO MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS...ESPECIALLY IN AREAS WHERE THE GROUND IS FROZEN. RISES ON RIVERS AND STREAMS ARE LIKELY...AND MINOR FLOODING CANNOT BE RULED OUT ON THE HOUSATONIC RIVER AND IT/S TRIBUTARIES IN NW CT. AS A RESULT...A FLOOD WATCH IS IN EFFECT FOR LITCHFIELD COUNTY. ELSEWHERE...MINOR FLOODING OF LOW LYING AREAS CANNOT BE RULED OUT EITHER...SUCH AS IN THE MID HUDSON VALLEY AND TACONICS...BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE THESE AREAS IN THE FLOOD WATCH AT THIS TIME. PART OF THIS UNCERTAINTY IS DUE TO QUESTIONS REMAINING OF HOW LONG PRECIP WILL BE WINTRY VS PLAIN RAINFALL. WHEN THE EXACT DURATION OF PRECIP TYPES BECOME MORE CLEAR...IT IS POSSIBLE THAT THE FLOOD WATCH MAY NEED TO BE EXPANDED. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH FROM 6 AM EST THIS MORNING THROUGH LATE TONIGHT FOR CTZ001-013. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ001-013. NY...WINTER STORM WARNING FROM 4 AM EARLY THIS MORNING TO 7 AM EST WEDNESDAY FOR NYZ032-033-038>040-042-043-047-048-051-058- 063-082. WINTER STORM WATCH FROM 4 AM EST EARLY THIS MORNING THROUGH WEDNESDAY MORNING FOR NYZ041-049-050-052>054-059>061-083- 084. FLOOD WATCH FROM 6 AM EST THIS MORNING THROUGH LATE TONIGHT FOR NYZ064>066. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ064>066. MA...WINTER STORM WATCH FROM 4 AM EST EARLY THIS MORNING THROUGH WEDNESDAY MORNING FOR MAZ001-025. VT...WINTER STORM WATCH FROM 4 AM EST EARLY THIS MORNING THROUGH WEDNESDAY MORNING FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS/GJM NEAR TERM...FRUGIS SHORT TERM...GJM LONG TERM...JPV AVIATION...KL/JPV HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MIAMI FL
1229 AM EST TUE DEC 9 2014 .AVIATION... COLD FRONT WILL BE MOVING ACROSS SOUTH FLORIDA EARLY IN THE FORECAST FOLLOWED BY POSSIBLE IFR CIGS. KPBI HAS ALREADY BECOME BKN006 BUT FOR NOW KEPT ALL OTHER TERMINALS AT BKN010-015 BUT MAY HAVE TO AMEND IF THE LOWER CIGS PAN OUT. HIGH RESOLUTION SHORT TERM GUIDANCE KEEPS CIGS AT MVFR BEFORE CLEARING OUT AT MID DAY. SURFACE WIND WILL BE W-NW AT 8-10KT BUT COULD HAVE BRIEF GUSTS APPROACHING 20KT AT A FEW LOCATIONS. KOB && .PREV DISCUSSION... /ISSUED 838 PM EST MON DEC 8 2014/ UPDATE... NO MAJOR CHANGES TO THE FORECAST THIS EVENING. SOME ADJUSTMENTS T POPS TO REFLECT CURRENT OBSERVATIONS AND MODEL TRENDS FOR TONIGHT. ALSO, THE SREF IS SHOWING THE BEST CHANCES OF FOG TO BE FURTHER SOUTH THAN ORIGINALLY FORECAST. IT IS ALSO SHOWING THAT IT IS POSSIBLE THE BROWARD/MIAMI-DADE METRO AREAS MAY ALSO HAVE SOME CHANCE OF SEEING FOG IN THE MORNING. BUT, HAVE KEPT IT OUT OF THOSE AREAS FOR NOW, WITH THE INTERIOR BEING THE MAIN AREA IMPACTED BY PATCHY FOG. HOWEVER, THE LATEST RUN OF THE HRRR IS ALSO SHOWING THE METRO AREAS BEING IMPACTED WITH FOG, INCLUDING THE PALM BEACH AREA. SO, THIS MAY NEED TO BE ADDED IN WITH THE NEXT UPDATE. PREV DISCUSSION... /ISSUED 659 PM EST MON DEC 8 2014/ AVIATION... VFR CONDITIONS WILL PERSIST THROUGH THE BULK OF THE PERIOD WITH LIGHT NW LOW-LEVEL FLOW CONTINUING. THERE IS SOME DISAGREEMENT BETWEEN GFS/NAM AND HRRR/RAP ON REGARD TO PATCHY FOG/LOW CIGS TONIGHT INTO TUESDAY MORNING ACROSS PORTIONS OF THE AREA ONCE AGAIN. WITH THE LOW CONFIDENCE INCLUDED VFR CONDITIONS WITH A FEW AND SCT LOW CLOUDS. PREV DISCUSSION... /ISSUED 345 PM EST MON DEC 8 2014/ DISCUSSION... THE MAIN SURFACE SYNOPTIC FEATURES ACROSS THE REGION INCLUDE A SURFACE LOW IN THE VICINITY OF BERMUDA WITH A TRAILING COLD FRONT ACROSS THE CENTRAL BAHAMAS AND THE FLORIDA STRAITS. IN ADDITION THERE IS A WEAK SURFACE TROUGH TO THE NORTHWEST OF THE FLORIDA PANHANDLE. AT THE MID TO UPPER LEVELS THERE IS A LARGE AMPLITUDE MID TO UPPER LEVEL TROUGH WEST OF THE GREAT LAKES EXTENDING SOUTHWARD TO THE NORTHERN GULF. THE MID TO UPPER LEVEL TROUGH IS FORECAST TO SHIFT EASTWARD INTO THE EASTERN GULF TONIGHT WITH A RE-ENFORCING SURFACE BOUNDARY MOVING INTO THE FLORIDA PENINSULA TONIGHT. THIS WILL MAINTAIN NORTHERLY WINDS ACROSS THE REGION TONIGHT INTO TUESDAY WITH ADDITIONAL COLD AIR ADVECTION. THE COMBINATION OF COOLER AIR AND LINGERING MOISTURE COULD RESULT IN FOG ACROSS SOUTH FLORIDA EARLY TUESDAY MORNING. THE MOST RECENT MODEL GUIDANCE ALSO SUGGESTS A CHANCE OF FOG EARLY TUESDAY AND IS INDICATED IN THE FORECAST. AS NOTED EARLIER...THE COMBINATION OF A PERSISTENT PRESSURE GRADIENT AND WELL ESTABLISHED NORTHEAST FETCH ACROSS THE WESTERN ATLANTIC EAST OF THE CAROLINAS IS FORECAST TO PRODUCE LONG PERIOD NORHTHEASTERLY SWELL THAT WILL CONTINUE TO ENTER THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY TODAY. THE LONG PERIOD SWELL WILL CONTINUE TO ENTER THE REGIONAL ATLANTIC WATERS TONIGHT INTO TUESDAY AND FORECAST TO CONTINUE THROUGH AT LEAST WEDNESDAY. THIS PROMPTED THE ISSUANCE OF A HIGH RISK OF RIP CURRENTS FOR THE ATLANTIC COAST BEACHES TODAY THROUGH WEDNESDAY EVENING. IN ADDITION...A HIGH SURF ADVISORY IS IN EFFECT FOR TUESDAY MORNING THROUGH WEDNESDAY MORNING FOR THE BEACHES OF PALM BEACH COUNTY WITH SURF HEIGHTS FORECAST TO BE NEAR 10 FEET BY EARLY TUESDAY MORNING. FOR THE FORECAST TUESDAY THROUGH FRIDAY...MAINLY DRY AND STABLE CONDITIONS AND NORTHERLY TO NORTHWESTERLY WINDS ARE FORECAST THROUGH THIS PERIOD WITH UNSEASONABLY COOLER TEMPERATURES PREVAILING. MARINE... AS MENTIONED ABOVE...LONG PERIOD NORHTHEASTERLY SWELL WILL CONTINUE TO ENTER THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY TODAY THEN CONTINUE TO ENTER THE ATLANTIC WATERS TONIGHT INTO TUESDAY AND FORECAST TO CONTINUE THROUGH AT LEAST WEDNESDAY. IN ADDITION NORTHWESTERLY WINDS IN THE 15 TO 20 KNOT RANGE ARE FORECAST TO BUILD INTO THE REGIONAL WATERS ON TUESDAY. WINDS ACROSS THE ALTANTIC WATERS COULD REACH THE 20-22 KNOT RANGE LATER ON TUESDAY. THE COMBINATION OF THE BUILDING SWELL AND WINDS TO ADVISORY LEVELS WILL RESULT IN HAZARDOUS SEAS ACROSS THE ATLANTIC WATERS WITH SMALL CRAFT ADVISORY IN EFFECT ALL ATLANTIC WATERS THIS EVENING THROUGH WEDNESDAY EVENING. && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR FLZ168-172- 173. HIGH SURF ADVISORY FROM 7 AM THIS MORNING TO 10 AM EST WEDNESDAY FOR FLZ168. AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR AMZ650-651-670- 671. HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR AMZ630. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1204 AM CST TUE DEC 9 2014 .UPDATE... 843 PM CST FOR EVENING UPDATE... UPDATED FORECAST TO REMOVE MUCH OF THE FOG AS VISIBILITY HAS IMPROVED MARKEDLY FROM EARLIER. ALSO ADJUSTED POP/WEATHER FOR LIGHT RAIN/SNOW COMBO CHANGING TO LIGHT SNOW PRIOR TO ENDING AFTER MIDNIGHT. SURFACE LOW PRESSURE WAS DRIFTING SOUTHEAST ACROSS THE WESTERN GREAT LAKES REGION THIS EVENING...WITH OCCLUDED COLD FRONT NOW PUSHING EAST ACROSS THE LAKE AND NORTHWEST INDIANA AS OF 02Z/8 PM CST. INTRUSION OF SOMEWHAT DRIER LOW LEVEL AIR HAS HELPED ERODE MUCH OF THE FOG AND LOWEST CLOUD BASES BEHIND THE FRONT...THUS HAVE REMOVED FOG FROM FORECAST EXCEPT FOR NEXT FEW HOURS OVER THE LAKE. ALOFT...ROBUST MID-LEVEL SHORT WAVE CIRCULATION WAS NEARLY OVERHEAD PER CURRENT WATER VAPOR IMAGERY AND 00Z RAOB ANALYSIS...AND IS NI THE PROCESS OF FORMING A CLOSED MID-LEVEL LOW CENTER WHICH WILL CONTINUE TO SLIDE OFF TO THE SOUTHEAST OF THE AREA OVERNIGHT. REGIONAL RADAR MOSAIC DEPICTS LIGHT PRECIPITATION ASSOCIATED WITH THIS FEATURE MAINLY ALONG ITS NORTHERN/EASTERN FLANKS...GENERALLY THE NORTHEAST HALF OR SO OF THE WFO LOT CWA. 00Z SOUNDINGS FROM DVN AND ILX SHOW MOISTURE GENERALLY BELOW 800-700 MB AND WITH CLOUD BEARING LAYER MIN TEMPS LESS THAN -10 C...RESULTING IN MAINLY DRIZZLE AND LIGHT RAIN WITH LACK OF ICE NUCLEATION. DEEPER MOISTURE FARTHER NORTH (GRB SOUNDING) WAS ASSOCIATED WITH BETTER PRECIPITATION ELEMENTS CLOSER TO THE MID-LEVEL CIRCULATION ACROSS EAST/SOUTHEAST WI WAS RESULTING IN WET SNOW. THIS DEEPER MOISTURE WITH THE MID-LEVEL WAVE AND A SLOW COOLING OF THE COLUMN IN THE WAKE OF THE COLD FRONT WILL LIKELY ALLOW FOR PRECIP TO MIX/CHANGE TO A LITTLE WET SNOW WHERE IT FALLS A LITTLE STEADIER...ESPECIALLY ACROSS FAR NORTHEAST IL THROUGH A LITTLE PAST MIDNIGHT AND INTO NORTHWEST INDIANA THROUGH EARLY TUESDAY MORNING. LOW SNOW TO LIQUID RATIOS AND LIGHT NATURE OF PRECIP SHOULD PRECLUDE ANY SIGNIFICANT ACCUMULATIONS OTHER THAN A FEW SLUSHY TENTHS PERHAPS IN ISOLATED AREAS BEFORE PRECIPITATION ENDS. RATZER && .SHORT TERM... 317 PM CST THROUGH WEDNESDAY... LIGHT RAIN OR DRIZZLE AND SOME PATCHY LIGHT SNOW ALL ARE LIKELY TO MAKE AN APPEARANCE THIS EVENING...ALONG WITH AREAS OF FOG. WATER VAPOR SATELLITE IMAGE SHOWS TWO UPPER CIRCULATIONS THAT WILL CROSS THE AREA...AND MODEL VORTICITY FIELDS ALOFT AND RH FIELDS AT LOWER LEVELS ALL SUPPORT THE IDEA OF PATCHY AREAS OF PRECIPITATION. AS OF LATE AFTERNOON MOST AREAS ARE IN THE MIDDLE TO UPPER 30S...AND PRECIP CHANCES SHOULD DIMINISH AS COLDER AIR APPROACHES...SO LITTLE IF ANY FROZEN PRECIPITATION WOULD BE EXPECTED TO ACCUMULATE. BY MORNING THE AXIS OF THE UPPER LONGWAVE IS WELL TO OUR EAST...AND UPPER SHORTWAVE ENERGY BEGINS TO EXIT THE AREA AS WELL. ONLY AT LOW LEVELS DO RH FIELDS SUGGEST CONTINUED SATURATION...SO WILL TREND POPS DOWNWARD TO BELOW MENTIONABLE LEVELS BY DAYBREAK EXCEPT DOWNWIND FROM THE LAKE IN NORTHWEST INDIANA AT THE END OF A NORTHWEST FETCH. EVEN THAT AREA APPEARS TO DRY OUT BY LATE TOMORROW AS WINDS CONTINUE VEERING NORTHEASTERLY AND LOW LEVELS DRY CONSIDERABLY. CLOUDINESS PERSISTS SOUTH OF THE LAKE LATE TOMORROW INTO TOMORROW NIGHT...BUT AREAS WEST CLEAR OUT A BIT. THIS ACCOUNTS FOR A FEW DEGREE TEMPERATURE DIFFERENCE IN TUESDAY NIGHT LOWS BETWEEN MORE CLEAR AND MORE OVERCAST AREAS. WEDNESDAY CONTINUES COOL...BUT NOT UNSEASONABLY SO...WITH GRADUALLY CLEARING SKIES. LENNING && .LONG TERM... 317 PM CST WEDNESDAY NIGHT THROUGH TUESDAY... THE REMAINDER OF THE WEEK AND ESPECIALLY THE WEEKEND DO NOT LOOK TOO BAD AT ALL FOR MID DECEMBER. COMPARED TO LAST MONTH...THE STRETCH OF DAYS STARTING ON FRIDAY THE 12TH LOOKS TO BE FROM 10 TO 20 DEGREES WARMER THAN THE SAME PERIOD FROM LAST MONTH. SO THE MIDDLE PORTIONS OF NOVEMBER AND DECEMBER APPEAR TO BE SWAPPED THIS YEAR. MODELS ARE IN REASONABLE THOUGH NOT PERFECT AGREEMENT THAT THE LARGE UPPER TROUGH NOW OVERHEAD WILL MOVE INTO THE EASTERN CONUS AND ALLOW A BROAD RIDGE FROM THE SFC TO UPPER LEVELS TAKE ITS PLACE. THIS RIDGING WITH ITS DRY AND MILD WEATHER APPEARS TO PERSIST AT LEAST INTO THE MIDDLE PART OF THE WEEKEND WHILE SLOWLY DRIFTING EAST. BY EARLY SUNDAY MODELS START TO SUGGEST A RETURN OF BETTER MOISTURE AHEAD OF AN APPROACHING FRONTAL ZONE ACROSS THE PLAINS AND WEST OF THE RIDGE. CONFIDENCE ON THE TIMING OF THIS MOIST SOUTHERLY FLOW INTO THE LOCAL AREA IS LOW...SO HAVE ELECTED TO INCLUDE INCREASED POPS BY SUNDAY AND MONDAY BUT ALL IN THE FORM OF LIGHT RAIN. LENNING && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * LOW END MVFR CIGS THROUGH THE MORNING WITH SOME INTERMITTENT IFR CIGS POSSIBLE THE NEXT FEW HOURS. CIGS GRADUALLY RISE BUT REMAIN MVFR INTO THIS EVENING/OVERNIGHT. * -DZ THROUGH EARLY MORNING WITH SCATTERED -RASN SHOWERS PRIOR TO 09 OR 10Z. BRIEF MVFR VSBY POSSIBLE. * WEST-NORTHWEST WINDS SHIFT NORTHWEST OVERNIGHT AND NORTH INTO EARLY AFTERNOON. GUSTS AROUND 20 KT THIS AFTERNOON. MDB //DISCUSSION...UPDATED 06Z... LATEST OBSERVATIONS SHOW A MIX OF IFR AND LOW MVFR CIGS ACROSS THE REGION WHICH IS COMPLICATING FORECAST DETAILS. EXPECT THAT LOW MVFR WILL TAKE OVER AS THE MAIN CIG HEIGHT THROUGH THE OVERNIGHT WITH SOME VARIABILITY BETWEEN MVFR/IFR PRIOR TO THAT. DRIZZLE APPEARS TO BE DECREASING IN COVERAGE BUT WILL BE CONTINUING FOR A FEW HOURS. A PASSING UPPER WAVE CONTINUES TO PRODUCE SOME -RASN SHOWERS BUT COVERAGE OF THESE IS ALSO DECLINING. WINDS WILL BE TURNING MORE NORTHWESTERLY OVERNIGHT...WITH GYY STARTING TO SEE SOME GUSTS AS TRAJECTORY ACROSS LAKE MICHIGAN INCREASES. CIGS LOOK TO REMAIN IN PLACE THROUGH THE AFTERNOON AND PROBABLY THE EVENING FOR MOST AREAS. THERE SHOULD BE A GRADUAL RISING OF BASES BUT THINGS MAY BE HARD PRESSED TO RISE ABOVE 2000 FT BEFORE MID/LATE AFTERNOON. TIMING OF INCREASES WILL LIKELY NEED ADJUSTMENT. WINDS WILL TURN NORTH-NORTHWEST OR EVEN DUE NORTH INTO THE AFTERNOON WITH GUSTS TO AROUND 20 KT DEVELOPING. GYY MAY SEE GUSTS INTO THE MID OR EVEN UPPER 20S AS THE FETCH DOWN LAKE MICHIGAN INCREASES. LAKE EFFECT SHOWERS WILL LIKELY DEVELOP AND MAY IMPACT GYY GIVEN THE NORTH WIND BUT THE BULK OF THE ACTIVITY MAY BE JUST TO THE EAST. HAVE ADDED VCSH MENTION FOR MOST OF THE DAY. CIGS MAY TRY TO SCATTER FROM THE NORTHWEST INTO THE EVENING BUT A NORTH-NORTHEAST FLOW IN THE CLOUD BEARING LAYER OFF THE LAKE WILL LIKELY KEEP AT LEAST SOME MVFR CIGS ACROSS THE CHICAGO METRO AREA...WITH STEADIER CIGS OVER NORTHWEST INDIANA. MDB //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN MVFR CIGS PERSISTING THROUGH AT LEAST THE AFTERNOON. MEDIUM CONFIDENCE IN AT LEAST SOME RISING OF CIG BASES THIS AFTERNOON BUT LOW CONFIDENCE IN HOW QUICKLY IT MAY OCCUR. MEDIUM CONFIDENCE IN INTERMITTENT IFR CIGS OVERNIGHT. * HIGH CONFIDENCE IN -DZ PERSISTING WITH A DECREASE IN -RASN SHOWERS INTO EARLY MORNING. * HIGH CONFIDENCE IN WIND TRENDS. MDB //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY...MVFR CIGS POSSIBLE EARLY...THEN VFR. NORTH WINDS. THURSDAY...VFR. WEST WINDS. FRIDAY...MAINLY VFR. MVFR CIGS POSSIBLE AT NIGHT. SOUTHWEST WINDS. SATURDAY...MVFR CIGS POSSIBLE. SOUTH WINDS. SUNDAY...MVFR CIGS POSSIBLE. SLGT CHANCE OF RAIN. SOUTH WINDS. RATZER && .MARINE... 227 PM CST LOW PRESSURE IS OVER NORTHERN WISCONSIN AND IT WILL WEAKEN AS IT MOVES ACROSS THE LAKE TONIGHT. WINDS TURN NORTHWEST BEHIND THE LOWS COLD FRONT AND THEN THEY TURN NORTH AS HIGH PRESSURE BUILDS OVER MINNESOTA. THE GRADIENT TIGHTENS BETWEEN THE HIGH AND LOW WITH 30 KT NORTH WINDS EXPECTED ACROSS THE LAKE TOMORROW. WINDS AND WAVES WILL INCREASE IN THE NEARSHORE WATERS SO HOISTED A SMALL CRAFT ADVISORY BEGINNING EARLY TUESDAY MORNING. WINDS DIMINISH TUESDAY NIGHT AS THE HIGH APPROACHES BUT LARGE WAVES WILL LINGER IN THE NSH ZONES. HAVE MEDIUM CONFIDENCE IN HOW LONG THE HAZARDOUS WAVES WILL LINGER...BUT HAVE THE SMALL CRAFT ADVISORY GOING INTO WEDNESDAY NIGHT. NORTH WINDS BECOME NORTHWEST AS THE HIGH MOVES DOWN THE MISSISSIPPI VALLEY WEDNESDAY NIGHT AND CONTINUE TO BACK TO SOUTHWEST BY FRIDAY AFTERNOON. THE HIGH FINALLY SHIFTS EAST OVER THE OHIO VALLEY SATURDAY WITH THE NEXT LOW FORMING OVER THE PLAINS SATURDAY NIGHT. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...6 AM TUESDAY TO 9 PM WEDNESDAY. SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 3 PM WEDNESDAY. && $$ 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 1112 PM CST Mon Dec 8 2014 .UPDATE... ISSUED AT 825 PM CST MON DEC 8 2014 Cold front has swept east of the state early this evening along with most of the light rain and drizzle. Low level flow has now shifted into the northwest and as a result, the cloud band that was shifting out of far west central Illinois this evening has been replaced by another band of clouds that was tracking southeast out of Iowa this afternoon and will be with us well into the morning hours of Tuesday. Not much in the way of precip over Iowa early this evening with the only snow and rain reports well to our north over far southern Wisconsin and northern IL. Most of the short term models suggest that light precip will remain to our north tonight. Current forecast has conditions well in hand for this evening and the overnight hours. Other than some minor wording adjustments in the overnight portion of the forecast, no other changes needed to the current ZFP. Will have the update out by 900 pm. && .SHORT TERM...(Tonight) ISSUED AT 248 PM CST MON DEC 8 2014 Cold front is pushing across central Illinois early this afternoon, located just west of Peoria and Springfield as of 2 pm. Extensive low cloud deck has been prevailing over the forecast area, with some localized dense fog along and north of the I-74 corridor. Surface observations showing visibilities and ceilings lifting behind the front, and the back edge of the cloudiness covered about the eastern third of Missouri. Well defined upper circulation evident on water vapor imagery over northeast Iowa, and this is producing some light rain and snow upstream from us. Main question for this part of the forecast is how much clearing will manage to take place. Lower clouds extend all the way back into southern North Dakota. RAP model guidance and current trajectories would suggest some clearing may take place over the far southwest parts of the forecast area for a short period, but a secondary surge of clouds is expected as the broad upper trough surrounding the aforementioned circulation swings through the Midwest this evening. Have kept the sky forecast on the pessimistic side and kept cloudy skies in the grids for tonight. Much of the associated precipitation should be just to our north, but will include some slight chance PoP`s for the northeast CWA for this evening. && .LONG TERM...(Tuesday through Monday) ISSUED AT 248 PM CST MON DEC 8 2014 As the low pressure area weakens and gets absorbed into an east coast system, a high pressure ridges will build into the area. This ridge will dominate the weather over the area through Wednesday and beyond. Some concern with lower level moisture remaining trapped under the ridge Tue through Wed, so have increased cloud cover to go mostly cloudy through Wed. As the center of the high pressure drops south into the southern Miss river valley, the ridge will remain over the area with dry weather through Thursday, the rest of the week and into the weekend. The area will also remain dominated by mid level cyclonic flow through the end of the week. Then mid level ridging, that was building in the plains, will begin to dominate the region for the weekend. Late in the weekend, the ridging will begin to push east and this will allow a frontal system to move into the area and bring rain to the region for Sun night and Monday. With high pressure dropping into the area and cyclonic flow, temps will remain cool for the next couple of days. But then as the high pressure settles south and mid level ridging builds, temps will begin to warm again. By the weekend, temps will warm to above normal, with 50s expected Sat and Sun. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1100 PM CST MON DEC 8 2014 MVFR cigs are expected thru Tuesday evening. A rather large storm system will continue to track off to our east tonight but the expansive cloud cover associated with the system will linger over our area at least thru 00z tomorrow. Most of the rain associated with the system`s cold front was well off to our east late this evening but the threat for some spotty drizzle will remain over parts of the area as a secondary upper level wave drifts southeast thru the region overnight. Based on upstream observations, we look for cigs to range from 1200 to 2000 feet late tonight thru the morning hours of Tuesday, before we see a gradual improvement during the afternoon to between 2000-3000 feet. Not very confident at this point, at least based on the latest forecast soundings for later tomorrow as a rather strong low level inversion is forecast to develop which will effectively trap the low level moisture. Boundary layer winds are forecast to be more from a north-northeast direction tomorrow which is not a very good direction for clearing skies in our area. Surface winds will be from the northwest to north at 8 to 14 kts tonight, and more from a northerly direction on Tuesday at 10 to 15 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Smith SHORT TERM...Geelhart LONG TERM...Auten AVIATION...Smith
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1140 PM EST MON DEC 8 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 222 PM EST MON DEC 8 2014 A COLD FRONT AND AN UPPER TROUGH WILL KEEP CHANCES FOR PRECIPITATION ACROSS CENTRAL INDIANA INTO TUESDAY. AFTERWARD HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THROUGH THE WEEKEND. CHANCES FOR RAIN RETURN MONDAY. BELOW AVERAGE TEMPERATURES WILL GIVE WAY TO ABOVE NORMAL READINGS BY THE WEEKEND. && .NEAR TERM /REST OF TONIGHT/... ISSUED AT 836 PM EST MON DEC 8 2014 0130Z UPDATE...BASED ON TRENDS THUS FAR THIS EVENING AGREE WITH PREVIOUS THINKING ON THE OVERNIGHT WEATHER. ONLY CHANGES WERE TO INCREASE POPS LATE THIS EVENING ON AVERAGE OF 20 PERCENT TO ACCOUNT FOR THE SECOND WAVE OF VERY LIGHT RAIN AND/OR DRIZZLE MOVING IN FROM CENTRAL ILLINOIS. LATEST RUNS SHOW HRRR AND SREF HAVE BACKED OFF ON POPS CONSIDERABLY AFTER 06Z...WHICH WILL BE POST FRONTAL PASSAGE...SO LEFT POPS AS IS AFTER THIS TIME. WILL NEED TO MONITOR TEMPERATURES ESPECIALLY AFTER 06Z AND FOR ANY ADDITIONAL SIGNIFICANT PRECIP DEVELOPMENT...BECAUSE IF TEMPS PLUMMET MAY HAVE SOME FREEZING DRIZZLE CONCERNS WHICH COULD CAUSE SLICK/ICY ROADS. MOST LOW TEMPERATURES IN FORECAST FOR CWA ARE EXPECTED TO REMAIN ABOVE FREEZING SO THIS IS NOT EXPECTED TO BE AN ISSUE...BUT WILL BE CLOSELY MONITORED REGARDLESS FOR POTENTIAL NEED FOR UPDATES AND/OR STATEMENTS. PREVIOUS DISCUSSION FOLLOWS... TONIGHT AN UPPER LOW WILL MOVE INTO THE AREA AND PROVIDE SOME ADDITIONAL FORCING. MAV MOS GIVES VERY LOW POPS WHILE MET MOS IS PRETTY HIGH. REALITY WILL LIKELY BE IN BETWEEN. MOISTURE BECOMES LIMITED TO THE LOWER LAYERS OF THE ATMOSPHERE PRETTY QUICKLY...SO THERE IS SOME QUESTION WHETHER ICE WILL BE INTRODUCED INTO THE CLOUD. TIME SECTIONS SHOW THAT IT WILL BE CLOSE...SO WILL KEEP MENTION OF DRIZZLE AND RAIN/SNOW THROUGH THE NIGHT. PRECIPITATION WILL BE LIQUID THROUGH THE EVENING...BUT TEMPERATURES COOL FROM NORTHWEST TO SOUTHEAST TONIGHT MAKING ANY PRECIPITATION /ASIDE FROM THE DRIZZLE/ SNOW. WENT NEAR MAV MOS MOST AREAS FOR LOWS TONIGHT. THIS KEEPS TEMPERATURES ABOVE FREEZING FOR MOST OF THE AREA FOR THE VAST MAJORITY OF THE NIGHT. THUS WHILE CANNOT ABSOLUTELY RULE OUT FREEZING DRIZZLE AT THIS TIME...FEEL THAT COVERAGE AND LENGTH OF ANY THAT DOES APPEAR IS TOO LOW TO MENTION AT THIS TIME. WILL KEEP MENTION OF SLICK SPOTS EARLY IN THE MORNING IN THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR BRIDGES/OVERPASSES/UNTREATED SURFACES. && .SHORT TERM.../TUESDAY THROUGH THURSDAY/ ISSUED AT 222 PM EST MON DEC 8 2014 FOCUS IS ON ANY CHANCES FOR PRECIPITATION TUESDAY THEN ON SKY COVER. MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED. EXITING UPPER SYSTEM AND CYCLONIC FLOW WILL KEEP CLOUDY SKIES ON TUESDAY AND COULD ALSO HELP PRODUCE SOME LIGHT PRECIPITATION...ESPECIALLY IF SOME LAKE ENHANCEMENT OCCURS ACROSS THE NORTHEAST. PROBLEM REMAINS LACK OF DEEP MOISTURE AND POTENTIAL LACK OF ICE IN THE CLOUDS. WITH THE UNCERTAINTY IN PRECIPITATION TYPE DECIDED TO KEEP MENTION OF DRIZZLE AND SNOW WITH LOW POPS MOST AREAS. AS NOTED IN THE NEAR TERM CANNOT ABSOLUTELY RULE OUT A BRIEF PERIOD OF FREEZING DRIZZLE SOME AREAS VERY EARLY TUESDAY...BUT NOT CONFIDENT ENOUGH TO MENTION AT THIS TIME. TUESDAY NIGHT FORCING ENDS SO DO NOT EXPECT PRECIPITATION. HIGH PRESSURE TRIES TO BUILD IN FROM THE WEST...BUT STRONG SYSTEM ACROSS THE NORTHEASTERN USA KEEPS THE AREA IN CYCLONIC FLOW. THUS EXPECT PLENTY OF CLOUDS ACROSS THE AREA. THE CLOUDS WILL LINGER INTO WEDNESDAY...ESPECIALLY EAST WITH THE AFOREMENTIONED STRONG SYSTEM. HIGH PRESSURE SHOULD GAIN MORE INFLUENCE WEDNESDAY NIGHT INTO THURSDAY...SO ALLOWED FOR PARTLY CLOUDY CONDITIONS ALL AREAS THEN. FOR TEMPERATURES...WENT BELOW MOS FOR HIGHS TUESDAY GIVEN EXPECTED CLOUD COVER. CUT SOME ON WEDNESDAY AS WELL WITH EXPECTED SKY COVER. OTHERWISE GENERALLY STUCK WITH A MODEL BLEND. && .LONG TERM /THURSDAY THROUGH MONDAY/... ISSUED AT 257 PM EST MON DEC 8 2014 MODELS IN GOOD AGREEMENT THAT A BROAD AREA OF SURFACE HIGH PRESSURE ALONG WITH A DRY ATMOSPHERIC COLUMN WILL RESULT IN ABOVE NORMAL TEMPERATURES AND DRY WEATHER THROUGH THE WEEKEND. MEANWHILE...THE OPERATIONAL 12Z GFS AND ECMWF ARE HAVING DIFFICULTIES COMING TOGETHER FOR DAY 7 WITH THE GFS QUICKER WITH SEPARATE UPPER LOWS...IN SPLIT FLOW...ACROSS THE UPPER AND LOWER MISSISSIPPI VALLEYS. DESPITE BEING QUICKER WITH THESE SYSTEMS...THE GFS WAS SLOWER WITH THE QPF THAN THE EURO. WITH THE GFS TYPICAL TOO FAST AND THE EURO TO STRONG WITH STRONGER SYSTEMS IN SPLIT FLOW...WILL ACCEPT THE REGIONAL BLEND WHICH HOLDS OFF RAIN CHANCES TIL MONDAY. 00Z DECEMBER 8 ECM MOS HIGHS CLOSE TO REGIONAL BLEND AND LOOK GOOD WITH ABOVE AVERAGE HIGHS IN THE 40S AND PERHAPS EVEN 50S BY SUNDAY. THIS ALSO MATCHES UP NICELY WITH THE CLIMATE PREDICTION CENTER 6 TO 10 DAY OUTLOOK WHICH STRONGLY FAVORS ABOVE NORMAL TEMPERATURES FOR THE EXTENDED. && .AVIATION /DISCUSSION FOR THE 090600Z TAFS/... ISSUED AT 1140 PM EST MON DEC 8 2014 APPEARS COLD FRONT WILL BE IN THE PROCESS OF PASSING OFF TO THE EAST OF KIND/KBMG NEAR TO SHORTLY AFTER ISSUANCE TIME. MUCH OF THE POST FRONTAL IFR CEILINGS HAVE DISSIPATED...ALTHOUGH EXTENSIVE MVFR DECK AROUND 015 EXTENDS WELL UPSTREAM INTO THE NORTHERN MIDWEST. THERE MAY BE A BRIEF PERIOD WHERE THE MVFR CEILINGS SCATTER OUT IN THE IMMEDIATE POST FRONTAL ZONE...BUT FOR THE MOST PART EXPECTING CEILINGS AROUND 015...LINGERING BEYOND 091800Z. SOME LIGHT SNOW BEGINNING TO SHOW UP OVER PARTS OF SOUTHERN WISCONSIN AND NORTHERN ILLINOIS UNDER THE UPPER LOW. SHORT TERM MODELS SUGGEST THE UPPER LOW WILL MOVE OVER THE TAF SITES ROUGHLY 091000Z-091600Z...SO THERE MAY BE SOME PERIODS OF LIGHT SNOW DURING THOSE TIMES. IFR VISIBILITY RESTRICTIONS UNDER THE UPPER SYSTEM HAVE ONLY BEEN ISOLATED IN NATURE SO FAR...SO WILL KEEP THE VISIBILITY FORECAST ABOVE IFR FOR NOW. IN THE WAKE OF THE FRONT...SURFACE WINDS EXPECTED TO SETTLE AROUND 290-310 DEGREES AT 9-13 KTS OVERNIGHT. WINDS MAY VEER A BIT MORE TOWARDS 320-340 DEGREES BY LATE MORNING WITH SOME GUSTS 18-20 KTS PROBABLE. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...SMF/50 SHORT TERM...50 LONG TERM...KOCH AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
304 AM CST TUE DEC 9 2014 .SHORT TERM /TODAY/... ISSUED AT 301 AM CST TUE DEC 9 2014 CLOUD COVER AND TEMPS WERE THE FOCUS AS THE SURFACE HIGH SLOWLY BUILDS INTO THE STATE THROUGHOUT THE DAY TODAY. CAA CONTINUES THIS MORNING AND FINALLY DIMINISHES BY THE EARLY AFTERNOON. LOW LEVEL MOISTURE LOOKS TO POTENTIALLY REMAIN TRAPPED UNDER THE INVERSION SETTING UP AROUND 925M THROUGH THE DAY. THIS WOULD SUGGEST LOW STRATUS DECK TO LINGER INTO THE AFTERNOON AND INCREASED SKY COVER DURING THIS TIME TO REFLECT THIS TREND. THE 09.06Z HRRR AND 09.03Z HOPWRF HINTING ON CLOUD COVER LASTING THROUGH THE AFTERNOON HOURS TODAY AS WELL. TEMPS SHOULD STRUGGLE TO INCREASE MUCH TODAY WITH THE STRATUS AND CAA PERSISTING FOR MUCH OF THE DAY. LOWERED MAX TEMPS ACROSS THE NORTH AND WEST A DEGREE BUT LEFT THE REMAINDER OF THE FORECAST WITH PREVIOUS FORECAST AS IT LOOKED ON TRACK. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 301 AM CST TUE DEC 9 2014 OVERALL...THE MID TO LATE WEEK PATTERN WILL FEATURE A PERIOD OF INCREASED WARMING AND MOISTURE. SUBJECTIVE H850 ANALYSIS TONIGHT SHOWS UPPER LEVEL LOW AND COLD AIR ADVECTION OVER THE REGION...WITH THE GREAT LAKES WAVE SUPPRESSING MOISTURE TO THE FAR SOUTHERN STATES. HIGH PRESSURE ALOFT OVER THE SOUTHERN PLAINS IS ALREADY SUPPORTING RETURN FLOW OVER THE RED RIVER VALLEY INTO NEW MEXICO. MODELS SHOW THAT THIS PLUME WILL GRADUALLY MOVE NORTHWEST THEN NORTHEAST INTO THE CENTRAL PLAINS BY MID TO LATE WEEK...AND THROUGH THE WEEKEND. THOUGH THE PATTERN REMAINS FAIRLY QUIET INTO THE EARLY WEEKEND...THE RETURN OF MOISTURE AND LOW STRATUS ALONG WITH DRIZZLE OR LIGHT RAIN POTENTIAL WILL BE THE MAIN CHALLENGES IN THE NEXT 5 DAYS. FOR TONIGHT...A WEAK WAVE CURRENTLY OVER MONTANA WILL DROP SOUTHEAST INTO THE NORTHWEST FLOW AND BRING WITH IT ANOTHER AREA OF MID LEVEL CLOUDS TO THE REGION LATE THIS EVENING AND OVERNIGHT. WEAK WARM AIR ADVECTION WILL ACCOMPANY THE SYSTEM...ALLOWING TEMPERATURES OVERNIGHT TO REMAIN SIMILAR TO EARLY THIS MORNINGS LOWS. CLOUDS WILL PASS THROUGH THE AREA AGAIN WEDNESDAY NIGHT AND THURSDAY WITH CONTINUED WARM AIR ADVECTION AND MOISTURE ADVECTION ON THE BACK SIDE OF THE RIDGE. ONCE AGAIN WITH TONIGHTS RUN...THE NAM IS FASTER WITH SATURATION AT LOWER LEVELS WHILE THE GFS INITIALLY WED NIGHT AND THURSDAY MORNING DOES NOT SHOW SATURATION...BUT LATER IN THE DAY THURSDAY INTO THURSDAY NIGHT/FRIDAY. HAVE OPTED TO MAINTAIN A DRY FORECAST FOR NOW. BUFR SOUNDINGS SHOW MORE WIDESPREAD CLOUDS THURSDAY INTO FRIDAY...WHICH MAY IMPACT MINS AND ESPECIALLY HIGHS BOTH DAYS. FOR NOW...HAVE TRIMMED FRI HIGHS A BIT OVER THE AREA BACK DOWN INTO THE MID TO UPPER 40S CENTRAL TO LOWER 50S WEST/SOUTH. BY SATURDAY SOUTHWEST FLOW WILL PERSIST ACROSS THE ENTIRE REGION WITH READINGS INTO THE LOWER TO MID 50S OVER MOST OF THE SOUTH...UPPER 40S NORTHEAST. STRATUS WILL STILL BE PREVALENT ACROSS THE AREA...BUT MIXING MIGHT PROMOTE SOME BREAKS IN CLOUD COVER. DIFFUSE WARM AIR ADVECTION ALOFT MAY BE ENOUGH TO PRODUCE A FEW LIGHT SHOWERS AS WELL...ESPECIALLY LATER IN THE AFTERNOON WEST INTO SATURDAY NIGHT. MODELS CONTINUE TO SHOW A MORE PRONOUNCED WAVE BY DAYS 6 AND 7 WITH A LEE SIDE TROUGH DEEPENING OVER THE SOUTHERN PLAINS. THE MODELS STILL DIVERGE ON SOLUTIONS WITH THE GFS FARTHER NORTH AND PHASING THE TWO STREAMS WHILE THE EURO IS MORE PROGRESSIVE BUT DOES ALSO ALLOW FOR A RAIN SNOW MIX BY MONDAY. GIVEN THE UNCERTAINTY...WILL MAINTAIN A BLENDED APPROACH UNTIL DETAILS BECOME MORE APPARENT. AFTER A MILD WEEKEND...PASSAGE OF SYSTEM MONDAY WILL USHER IN COOLER TEMPERATURES FOR EARLY NEXT WEEK. && .AVIATION...09/06Z ISSUED AT 1102 PM CST MON DEC 8 2014 LOW STRATUS CONTINUES TO BE IN PLACE ACROSS THE CWA WITH A FEW HOLES EVERY NOW AND THEN. OVERALL CIGS IN THE MVFR RANGE AROUND BKN015-025...BUT A FEW SPOTS IN THE LOW VFR RANGE AS WELL. LOOKS LIKE LOW CIGS TO REMAIN THROUGH THE NIGHT AND INTO TUESDAY BEFORE BREAKING UP SOME DURING THE DAY. HOWEVER MOISTURE PLOTS ADVERTISE THEM REFORMING IN THE EVENING WITH SOUTHERLY FLOW AND MOISTURE PUSHING BACK INTO THE CWA. THEREFORE HAVE ADVERTISED WITH A SCT DECK ATTM SINCE UNCERTAINTY IS HIGH. NORTHWEST WINDS TO BECOME MORE NORTHERLY THROUGH THE PERIOD AND THEN SHIFT AROUND TO THE EAST SOUTHEAST LATE TUESDAY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
403 AM CST TUE DEC 9 2014 ...UPDATED LONG TERM... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM CST TUE DEC 9 2014 HIGH LEVEL CLOUD COVER WILL BE LIKELY TODAY ACROSS THE CENTRAL HIGH PLAINS AS A COLD FRONT STALLS OUT IN EXTREME SOUTHWEST KANSAS BY LATE MORNING. CONFIDENCE IS NOT HIGH ON HOW DENSE THESE CLOUDS WILL BE BUT NAM, GFS, AND RAP ALL INDICATE A COOLING TREND IN THE 925MB TO 850MB LEVEL FROM 00Z TUESDAY TO 00Z WEDNESDAY. GIVEN THIS COOLING TREND, MORE CLOUDS TODAY COMPARED TO YESTERDAY, AND AN EASTERLY WIND WILL STAY CLOSE TO THE PREVIOUS FORECAST FOR HIGHS THIS AFTERNOON. TEMPERATURES CLIMBING INTO THE UPPER 50S TO NEAR 60 STILL LOOKS REASONABLE IN EXTREME SOUTHWEST KANSAS WHICH WILL BE NEAR/SOUTH OF THE COLD FRONT WHILE HIGHS ONLY IN THE MID 40S IN NORTH CENTRAL KANSAS. EXACTLY HOW THE GRADIENT WILL END UP BETWEEN THESE TWO EXTREMES IS UNCLEAR. ISENTROPIC AND MOISTURE ADVECTION WILL IMPROVE ACROSS WESTERN KANSAS IN THE 900MB TO 800MB LEVEL. STATUS ALONG WITH POSSIBLY SOME AREAS OF FOG APPEARING LIKELY AS THE LOWER LEVELS SATURATE OVERNIGHT. DEPTH OF THIS MOIST LAYER WILL BE IN THE 2000 TO 3000 FT AGL RANGE DEPENDING ON WHICH MODEL SOUNDING YOU EXAMINE. GIVEN THE DEPTH OF THIS LAYER AM TRENDING AWAY FROM INTRODUCING DRIZZLE LATE TONIGHT BUT IF THE NAM ENDS UP BEING MORE CORRECT THEN SOME PATCHY DRIZZLE COULD DEVELOP TOWARDS DAYBREAK. TEMPERATURES ARE EXPECTED TO FALL TO AROUND 32 DEGREES BUT GIVEN THE INCREASE IN LOW LEVEL MOISTURE FORECAST OVERNIGHT THE LOWS MAY OCCUR EARLY WITH TEMPERATURES THEN HOLDING NEARLY STEADY OR EVEN RISE A FEW DEGREES AFTER MIDNIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 358 AM CST TUE DEC 9 2014 THE PERIOD BETWEEN WEDNESDAY AND SATURDAY WILL BE A TRUE CHALLENGE WITH RESPECT TO SKY COVER AND RESULTING TEMPERATURES BOTH IN THE DAYTIME FOR HIGHS AS WELL AS LOWS OVERNIGHT. RELATIVELY MORE MOIST CONDITIONS IN THE BOUNDARY LAYER MARKED BY DEW POINTS IN THE UPPER 30S AND 40S COULD CONTRIBUTE TO EVENING/NIGHT FOG DEVELOPMENT IN ADDITION TO ALREADY EXPECTED STRATUS. STRATUS THAT DOES ERODE DURING THE DAY SHOULD BE ABLE RAPIDLY REDEVELOP ACROSS MUCH OF CENTRAL KANSAS INTO THE EVENING AS THE BOUNDARY LAYER COOLS DIURNALLY. MODELS SOUNDINGS GENERALLY LIMIT THE THICKNESS TO SLIGHTLY MORE THAN 2000 FT, WHICH IS NOT FAVORABLE FOR DRIZZLE DESPITE MODEL QPF OUTPUT. THE PRIMARY CHALLENGE WILL BE DETERMINING HOW FAR WEST THE STRATUS IMPACTS THE FORECAST AREA EACH DAY AND IT`S EFFECT ON TEMPERATURES. WEDNESDAY INTO THURSDAY NIGHT APPEARS LIKELY TO BRING THE MOST WIDESPREAD OVERCAST CONDITIONS, WHILE THE WESTERN MOST COUNTIES, GENERALLY WEST OF HIGHWAY 83 WILL EXPERIENCE THE MOST HOURS OF INSOLATION AND CLEAR SKIES DURING THIS TIMEFRAME. UNLESS THE MODELS SIGNIFICANTLY DIVERGE IN SOLUTIONS FROM THE CURRENT AND RECENT RUNS, SUNDAY NIGHT (OR AROUND THAT SYNOPTIC TIMESCALE/TIMEFRAME) LOOKS WET WITH RAIN POTENTIAL OR EVEN SNOW WITH AS UPPER DYNAMIC LOW PRESSURE MOVING THROUGH OR JUST SOUTH OF THE REGION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1116 PM CST MON DEC 8 2014 A SECONDARY SURFACE COLD FRONT WILL MOVE INTO WESTERN KANSAS OVERNIGHT. AS THIS FRONTAL BOUNDARY PASSES A NORTHEAST WIND AT NEAR 10 KNOTS WILL DEVELOP. IN ADDITION TO THE NORTHEASTERLY WINDS....AREAS OF STATUS AND FOG WILL BE POSSIBLE DURING THE PREDAWN HOURS. BASED ON THE LATEST HRRR AND 900-840MB MOISTURE PROFILES FROM THE RAP AND NAM IT CURRENTLY APPEARS THE AREA MORE FAVORABLE FOR THE LOW MVFR/IFR LOW CLOUDS AND IFR VSBY IN FOG WILL BE ALONG AND NORTH OF HIGHWAY 96 WHICH INCLUDES HAYS. THIS STATUS AND FOG WILL GIVE WAY TO VFR CONDITIONS BY 15Z. FURTHER SOUTH VFR CONDITIONS ARE EXPECTED OVERNIGHT AND TUESDAY. THE NORTHEAST WINDS AT 10 KNOTS OR LESS WILL GRADUALLY VEER TO THE SOUTHEAST DURING THE DAY AS A SURFACE RIDGE AXIS CROSSES CENTRAL AND EASTERN KANSAS. && .PRELIMINARY POINT TEMPS/POPS... DDC 49 33 47 37 / 0 10 10 0 GCK 52 31 50 33 / 0 10 10 0 EHA 59 34 57 33 / 0 0 0 0 LBL 56 36 56 35 / 0 10 10 0 HYS 42 29 43 35 / 0 10 10 0 P28 49 31 46 39 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...RUSSELL AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
228 AM CST TUE DEC 9 2014 ...UPDATED SHORT TERM DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM CST TUE DEC 9 2014 HIGH LEVEL CLOUD COVER WILL BE LIKELY TODAY ACROSS THE CENTRAL HIGH PLAINS AS A COLD FRONT STALLS OUT IN EXTREME SOUTHWEST KANSAS BY LATE MORNING. CONFIDENCE IS NOT HIGH ON HOW DENSE THESE CLOUDS WILL BE BUT NAM, GFS, AND RAP ALL INDICATE A COOLING TREND IN THE 925MB TO 850MB LEVEL FROM 00Z TUESDAY TO 00Z WEDNESDAY. GIVEN THIS COOLING TREND, MORE CLOUDS TODAY COMPARED TO YESTERDAY, AND AN EASTERLY WIND WILL STAY CLOSE TO THE PREVIOUS FORECAST FOR HIGHS THIS AFTERNOON. TEMPERATURES CLIMBING INTO THE UPPER 50S TO NEAR 60 STILL LOOKS REASONABLE IN EXTREME SOUTHWEST KANSAS WHICH WILL BE NEAR/SOUTH OF THE COLD FRONT WHILE HIGHS ONLY IN THE MID 40S IN NORTH CENTRAL KANSAS. EXACTLY HOW THE GRADIENT WILL END UP BETWEEN THESE TWO EXTREMES IS UNCLEAR. ISENTROPIC AND MOISTURE ADVECTION WILL IMPROVE ACROSS WESTERN KANSAS IN THE 900MB TO 800MB LEVEL. STATUS ALONG WITH POSSIBLY SOME AREAS OF FOG APPEARING LIKELY AS THE LOWER LEVELS SATURATE OVERNIGHT. DEPTH OF THIS MOIST LAYER WILL BE IN THE 2000 TO 3000 FT AGL RANGE DEPENDING ON WHICH MODEL SOUNDING YOU EXAMINE. GIVEN THE DEPTH OF THIS LAYER AM TRENDING AWAY FROM INTRODUCING DRIZZLE LATE TONIGHT BUT IF THE NAM ENDS UP BEING MORE CORRECT THEN SOME PATCHY DRIZZLE COULD DEVELOP TOWARDS DAYBREAK. TEMPERATURES ARE EXPECTED TO FALL TO AROUND 32 DEGREES BUT GIVEN THE INCREASE IN LOW LEVEL MOISTURE FORECAST OVERNIGHT THE LOWS MAY OCCUR EARLY WITH TEMPERATURES THEN HOLDING NEARLY STEADY OR EVEN RISE A FEW DEGREES AFTER MIDNIGHT. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 152 PM CST MON DEC 8 2014 BY TUESDAY NIGHT, THE UPPER AIR FLOW OVER THE PLAINS WILL HAVE TRANSITIONED TO A PSEUDO-NORTHWEST FLOW, WITH AN UPPER LEVEL RIDGE BEGINNING TO BUILD IN AFTERWARDS. THAT UPPER LEVEL RIDGE WILL EXIST FROM EASTERN NEW MEXICO THROUGH MINNESOTA, AND PERSIST THROUGH ABOUT FRIDAY. THIS SHOULD MEAN VERY FEW CLOUDS DURING THE DAY, WITH MAXIMUM TEMPERATURES IN THE 50S TO LOWER 60S. MINIMUM TEMPERATURES WILL AVERAGE IN THE MID 30S TO MID 40S, WARMING SLIGHTLY AS SATURDAY APPROACHES. NIGHTS WILL BE CLEAR WITH LIGHT WINDS, AND SOME PATCHY FOG IS LIKELY MAINLY NORTH OF I-70 AND EAST OF HIGHWAY 183, TUESDAY NIGHT AND WEDNESDAY NIGHT. THERE COULD BE SOME PATCHY FOG AS WELL THURSDAY NIGHT, BUT I HELD OFF ON THAT FOR NOW. SATURDAY WILL SEE AN UPPER LEVEL LOW PRESSURE TROUGH MOVE FROM THE WESTERN ROCKIES TO NEAR THE EASTERN ROCKIES. THE LOW LEVEL FLOW WILL TURN SOUTH, AS A COLD FRONT STARTS TO TRAVEL SOUTH THROUGH THE PLAINS SATURDAY NIGHT. MOISTURE WILL ADVECT NORTH THROUGH THE SOUTHERN PLAINS, AND A LITTLE CONVECTION MAY BE POSSIBLE IN OUR FAR SOUTHEASTERN ZONES LATE SATURDAY NIGHT. SATURDAY WILL BE FAIRLY WARM, WITH LOW TO MID 60S FOR HIGHS, WHICH WILL HELP DESTABILIZE THE LOWER ATMOSPHERE BY LATE IN THE DAY. FOR NOW, I PLACED RW IN THE GRIDS, AND WILL HAVE TO WAIT TO SEE LATER MODEL RUNS TO DETERMINE IF THERE WILL BE ANY THUNDER GRIDS WILL BE NEEDED. THAT COLD FRONT WILL PLUNGE THROUGH SATURDAY NIGHT, WITH THE UPPER LOW PASSING TO OUR SOUTH THROUGH OKLAHOMA. RAINSHOWERS SEEM THE BEST PRECIP CATEGORY FOR SUNDAY, WITH THE SUPERMODEL PLACING NEARLY 50 PERCENT POPS IN THE BARBER COUNTY AREA, 25 TO 30 PERCENT POPS IN THE HAYS TO DODGE CITY TO LIBERAL AREAS, AND LOWER 16 TO 20 PERCENT SLIGHT POPS FOR OUR WESTERN ZONES NEAR THE COLORADO BOARDER. THE UPPER LOW PRESSURE MOVES EAST DURING THE NIGHT SUNDAY NIGHT, AND THIS WILL HELP USHER SOME COLD AIR INTO OUR FORECAST AREA. I HAVE WENT WITH A MIX OF RAIN OR SNOW FOR ALL OF OUR FORECAST AREA SUNDAY NIGHT, EXCEPT IN THE FAR SOUTHEAST ZONES FROM PRATT TO COMANCHE COUNTY, WHERE ONLY RAIN SHOWERS WERE MENTIONED. SUNDAY WILL COOL OFF CONSIDERABLY, WITH HIGHS IN THE MID 40S TO LOWER 50S. MINIMUM TEMPERATURES SUNDAY NIGHT WILL RANGE FROM THE MID 20S FROM LACROSSE TO DODGE CITY TO LIBERAL AND NORTHWESTWARD, AND TO THE UPPER 20S TO LOWER 30S SOUTHEAST OF THAT LINE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1116 PM CST MON DEC 8 2014 A SECONDARY SURFACE COLD FRONT WILL MOVE INTO WESTERN KANSAS OVERNIGHT. AS THIS FRONTAL BOUNDARY PASSES A NORTHEAST WIND AT NEAR 10 KNOTS WILL DEVELOP. IN ADDITION TO THE NORTHEASTERLY WINDS....AREAS OF STATUS AND FOG WILL BE POSSIBLE DURING THE PREDAWN HOURS. BASED ON THE LATEST HRRR AND 900-840MB MOISTURE PROFILES FROM THE RAP AND NAM IT CURRENTLY APPEARS THE AREA MORE FAVORABLE FOR THE LOW MVFR/IFR LOW CLOUDS AND IFR VSBY IN FOG WILL BE ALONG AND NORTH OF HIGHWAY 96 WHICH INCLUDES HAYS. THIS STATUS AND FOG WILL GIVE WAY TO VFR CONDITIONS BY 15Z. FURTHER SOUTH VFR CONDITIONS ARE EXPECTED OVERNIGHT AND TUESDAY. THE NORTHEAST WINDS AT 10 KNOTS OR LESS WILL GRADUALLY VEER TO THE SOUTHEAST DURING THE DAY AS A SURFACE RIDGE AXIS CROSSES CENTRAL AND EASTERN KANSAS. && .PRELIMINARY POINT TEMPS/POPS... DDC 49 33 56 37 / 0 10 10 0 GCK 52 31 57 33 / 0 10 10 0 EHA 59 34 59 33 / 0 0 0 0 LBL 56 36 60 35 / 0 10 10 0 HYS 42 29 50 35 / 0 10 10 0 P28 49 31 53 39 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...BURKE AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1118 PM CST MON DEC 8 2014 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1116 PM CST MON DEC 8 2014 AT 00Z TUESDAY A 500MB TROUGH WAS LOCATED OVER CENTRAL MONTANA WITH 40 METER 500MB 12 HOUR HEIGHT RISES REPORTED AT GLASGOW, MT, 130 METER HEIGHT RISES REPORTED AT BISMARK, ND AND 110 METER HEIGHT RISES OBSERVED AT ABERDEEN, SD. FURTHER EAST A-27C 500MB LOW WAS LOCATED ALONG THE WISCONSIN ILLINOIS BORDER. A +100 KNOT 250MB JET STREAK WAS JUST WEST SOUTHWEST OF THIS 500 MB LOW WITH THE RIGHT EXIT REGION OF THIS JET BEING LOCATED OVER EASTERN NEBRASKA. AT THE 700MB LEVEL A 700 MB BAROCLINIC ZONE WAS LOCATED ACROSS THE CENTRAL PLAINS. 700MB TEMPERATURES VARIED FROM -4 AT TOPEKA AND -6C AT OMAHA TO +2C AT DODGE CITY. A 850MB BAROCLINIC ZONE EXTENDED FROM NORTHERN MISSOURI TO WESTERN SOUTH DAKOTA. AT 00Z TUESDAY ONE SURFACE BOUNDARY, WEAK COLD FRONT, EXTENDED FROM NORTHERN ARKANSAS TO SOUTHWEST KANSAS TO NORTHEAST COLORADO. ANOTHER COLD FRONT STRETCHED FROM SOUTHERN IOWA TO NORTHWEST NEBRASKA. LOW CLOUDS WERE OBSERVED NORTH OF THE SECOND COLD FRONT BASED ON SURFACE OBSERVATIONS AND 11-3.9 SATELLITE LOOP. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 208 PM CST MON DEC 8 2014 AN UPPER LEVEL SHORTWAVE TROUGH OVER THE NORTHERN PLAINS WILL PUSH SOUTHEASTWARD ACROSS THE MISSISSIPPI VALLEY TONIGHT, FOLLOWED BY ANOTHER WEAKER WAVE MOVING ACROSS THE NORTHERN PLAINS ON TUESDAY. THE FIRST WAVE WILL PUSH A WEAK COLD FRONT ACROSS WESTERN KANSAS AFTER MIDNIGHT TONIGHT WITH LIGHT AND VARIABLE WINDS SHIFTING TO NORTHEAST AND NORTH AT 10 TO 15 MPH. SOME LOW STRATUS AND LIGHT FOG WILL BE POSSIBLE MAINLY ACROSS THE I-70 CORRIDOR TOWARDS MORNING. SOME HIGH LEVEL CLOUDINESS WILL STICK AROUND TONIGHT ACROSS THE REST OF THE AREA. OVERNIGHT LOWS WILL BE RANGE FROM THE MID 20S ACROSS THE I-70 CORRIDOR, TO THE UPPER 20S TO AROUND 30 ELSEWHERE ACROSS WESTERN KANSAS. ON TUESDAY, LIGHT EAST WINDS BECOME SOUTHEASTERLY UPSLOPE AT 10 TO 15 MPH. AS COOLER HIGH PRESSURE DRIFTS EAST, UNDER PARTLY CLOUDY SKIES. HAVE LOWERED HIGHS A BIT WITH THE COOLER UPSLOPE FLOW AND COOLER GUIDANCE TEMPS. WILL RANGE HIGHS FROM THE MID 40S ACROSS I-70 TO THE LOW TO MID 50S ELSEWHERE. THE WARMEST LOOKS TO BE AT ELKHART AROUND 60. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 152 PM CST MON DEC 8 2014 BY TUESDAY NIGHT, THE UPPER AIR FLOW OVER THE PLAINS WILL HAVE TRANSITIONED TO A PSEUDO-NORTHWEST FLOW, WITH AN UPPER LEVEL RIDGE BEGINNING TO BUILD IN AFTERWARDS. THAT UPPER LEVEL RIDGE WILL EXIST FROM EASTERN NEW MEXICO THROUGH MINNESOTA, AND PERSIST THROUGH ABOUT FRIDAY. THIS SHOULD MEAN VERY FEW CLOUDS DURING THE DAY, WITH MAXIMUM TEMPERATURES IN THE 50S TO LOWER 60S. MINIMUM TEMPERATURES WILL AVERAGE IN THE MID 30S TO MID 40S, WARMING SLIGHTLY AS SATURDAY APPROACHES. NIGHTS WILL BE CLEAR WITH LIGHT WINDS, AND SOME PATCHY FOG IS LIKELY MAINLY NORTH OF I-70 AND EAST OF HIGHWAY 183, TUESDAY NIGHT AND WEDNESDAY NIGHT. THERE COULD BE SOME PATCHY FOG AS WELL THURSDAY NIGHT, BUT I HELD OFF ON THAT FOR NOW. SATURDAY WILL SEE AN UPPER LEVEL LOW PRESSURE TROUGH MOVE FROM THE WESTERN ROCKIES TO NEAR THE EASTERN ROCKIES. THE LOW LEVEL FLOW WILL TURN SOUTH, AS A COLD FRONT STARTS TO TRAVEL SOUTH THROUGH THE PLAINS SATURDAY NIGHT. MOISTURE WILL ADVECT NORTH THROUGH THE SOUTHERN PLAINS, AND A LITTLE CONVECTION MAY BE POSSIBLE IN OUR FAR SOUTHEASTERN ZONES LATE SATURDAY NIGHT. SATURDAY WILL BE FAIRLY WARM, WITH LOW TO MID 60S FOR HIGHS, WHICH WILL HELP DESTABILIZE THE LOWER ATMOSPHERE BY LATE IN THE DAY. FOR NOW, I PLACED RW IN THE GRIDS, AND WILL HAVE TO WAIT TO SEE LATER MODEL RUNS TO DETERMINE IF THERE WILL BE ANY THUNDER GRIDS WILL BE NEEDED. THAT COLD FRONT WILL PLUNGE THROUGH SATURDAY NIGHT, WITH THE UPPER LOW PASSING TO OUR SOUTH THROUGH OKLAHOMA. RAINSHOWERS SEEM THE BEST PRECIP CATEGORY FOR SUNDAY, WITH THE SUPERMODEL PLACING NEARLY 50 PERCENT POPS IN THE BARBER COUNTY AREA, 25 TO 30 PERCENT POPS IN THE HAYS TO DODGE CITY TO LIBERAL AREAS, AND LOWER 16 TO 20 PERCENT SLIGHT POPS FOR OUR WESTERN ZONES NEAR THE COLORADO BOARDER. THE UPPER LOW PRESSURE MOVES EAST DURING THE NIGHT SUNDAY NIGHT, AND THIS WILL HELP USHER SOME COLD AIR INTO OUR FORECAST AREA. I HAVE WENT WITH A MIX OF RAIN OR SNOW FOR ALL OF OUR FORECAST AREA SUNDAY NIGHT, EXCEPT IN THE FAR SOUTHEAST ZONES FROM PRATT TO COMANCHE COUNTY, WHERE ONLY RAIN SHOWERS WERE MENTIONED. SUNDAY WILL COOL OFF CONSIDERABLY, WITH HIGHS IN THE MID 40S TO LOWER 50S. MINIMUM TEMPERATURES SUNDAY NIGHT WILL RANGE FROM THE MID 20S FROM LACROSSE TO DODGE CITY TO LIBERAL AND NORTHWESTWARD, AND TO THE UPPER 20S TO LOWER 30S SOUTHEAST OF THAT LINE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1116 PM CST MON DEC 8 2014 A SECONDARY SURFACE COLD FRONT WILL MOVE INTO WESTERN KANSAS OVERNIGHT. AS THIS FRONTAL BOUNDARY PASSES A NORTHEAST WIND AT NEAR 10 KNOTS WILL DEVELOP. IN ADDITION TO THE NORTHEASTERLY WINDS....AREAS OF STATUS AND FOG WILL BE POSSIBLE DURING THE PREDAWN HOURS. BASED ON THE LATEST HRRR AND 900-840MB MOISTURE PROFILES FROM THE RAP AND NAM IT CURRENTLY APPEARS THE AREA MORE FAVORABLE FOR THE LOW MVFR/IFR LOW CLOUDS AND IFR VSBY IN FOG WILL BE ALONG AND NORTH OF HIGHWAY 96 WHICH INCLUDES HAYS. THIS STATUS AND FOG WILL GIVE WAY TO VFR CONDITIONS BY 15Z. FURTHER SOUTH VFR CONDITIONS ARE EXPECTED OVERNIGHT AND TUESDAY. THE NORTHEAST WINDS AT 10 KNOTS OR LESS WILL GRADUALLY VEER TO THE SOUTHEAST DURING THE DAY AS A SURFACE RIDGE AXIS CROSSES CENTRAL AND EASTERN KANSAS. && .PRELIMINARY POINT TEMPS/POPS... DDC 28 51 39 56 / 0 0 10 10 GCK 27 52 36 57 / 0 0 10 10 EHA 30 58 33 59 / 0 0 10 0 LBL 29 56 39 60 / 0 0 10 10 HYS 22 44 33 50 / 0 0 10 10 P28 29 50 33 53 / 0 0 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...KRUSE LONG TERM...BURKE AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 PM MST MON DEC 8 2014 .UPDATE... ISSUED AT 925 PM MST MON DEC 8 2014 HAVE ISSUED A DENSE FOG ADVISORY FOR AREAS GENERALLY EAST OF A LINE FROM TRENTON TO BREWSTER TO RUSSELL SPRINGS. 03Z RUC SIMILAR TO LATEST HRRR OUTPUT AND 00Z NAM BOOSTING CONFIDENCE THAT DENSE FOG WILL DEVELOP. UPDATE ISSUED AT 745 PM MST MON DEC 8 2014 UPDATES REQUIRED FOR FIRST AND SECOND PERIODS (TONIGHT AND TUESDAY) FOCUSING ON ARRIVAL OF POTENTIALLY DENSE FOG AND LOWER TEMPERATURES THEN PREVIOUSLY FORECAST. AT 0230Z CIRRUS SHIELD THAT WAS OVER THE AREA MOST OF THE DAY IS MOVING EAST AND SLOWLY OUT OF THE AREA. AM EXPECTING MORE TO MOVE IN LATER IN THE EVENING AND THROUGH THE DAY TOMORROW FROM THE NORTHWEST. AT THE SFC STRATUS PER SATELLITE OBS AND RUC 900MB RH FORECAST CURRENTLY OVER NORTHEAST NEBRASKA/SOUTHWEST IOWA. BY 06Z THIS NARROW CORRIDOR OF STRATUS FORECAST TO POSSIBLY REACH AREAS JUST TO THE NORTHEAST FROM MCCOOK TO NORTON. AS SFC HIGH CONTINUES TO BACK INTO THE AREA WITH LIGHT NORTHEAST WINDS STRATUS DECK EXPECTED TO REACH A TRENTON TO HILL CITY LINE BY 09Z THEN ROUGHLY A BENKELMAN TO COLBY AND OAKLEY LINE BY 12Z. IN THE TRENTON TO HILL CITY AND POINTS NORTHEAST AREAS WINDS ARE CALM AND RH NEAR 100 PERCENT. LATEST RUC/HRRR/NAM VISIBILITY FORECASTS ALL SHOWING DENSE FOG WITH VISIBILITIES 1/4 MILE OR LESS. NAM EXTRAPOLATION OF SATURATED BOUNDARY LAYER RH PUSHES IT FURTHER WEST TOWARD THE CO/KS BORDER WITH DENSE FOG CONTINUING ROUGHLY FROM TRENTON TO HOXIE AND POINTS EAST. HRRR SUGGESTS FURTHER WEST TOWARD BENKELMAN TO NEAR GOODLAND AND RUSSELL SPRINGS. WILL AWAIT THE 03Z RUC/LATEST HRRR BEFORE ZONE UPDATE SENT BUT HAVE TRENDED TOWARD ABOVE THINKING. && .SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY) ISSUED AT 119 PM MST MON DEC 8 2014 DECENT AFTERNOON ACROSS THE ENTIRE FORECAST AREA...AS THE TRI STATE REGION IS SEEING TEMPERATURES 15 TO 20 DEGREES ABOVE NORMAL WITH READINGS WELL INTO THE 50S. THIS IS ONGOING DESPITE HIGH CLOUDS MOVING OVER THE AREA CREATING SUNNY CONDITIONS. HIGH CLOUD COVER WILL SCATTER OUT DURING THE EARLY EVENING HOURS IN TIME FOR 925MB THERMAL BOUNDARY/SURFACE RIDGE AXIS COMBO...WHICH MODELS BRING OVER THE REGION BY MIDNIGHT TONIGHT. MODEL RH IN LATEST BUFKIT RUNS DOES HINT AT FOG/LOW STRATUS FORMATION BETWEEN 06Z-14Z TUESDAY...WITH BEST CHANCES OVER IN CENTRAL AND EASTERN ZONES. LGT/VAR WIND CONDITIONS WILL ALSO AID IN FOG FORMATION IN THE AFOREMENTIONED ZONES...SO WILL KEEP PREVIOUS MENTION OF FOG IN THE FORECAST. GOING INTO TUESDAY...SURFACE HIGH PRESSURE SETTLES OVER CENTRAL AND EASTERN PLAINS. THIS IS GOING TO SET UP YET ANOTHER NICE DAY FOR MUCH OF THE CWA. MUCH OF THE WESTERN CWA WILL SEE WAA AGAIN ON SOUTHERLY FLOW...WHILE EASTERN ZONES WILL BE CLOSE ENOUGH TO SURFACE RIDGE THAT WINDS WILL NOT BE MAJOR FACTOR...SO HAVE TAPERED HIGHS FOR TOMORROW FROM WEST TO EAST...MID 50S WEST DOWN TO THE MID 40S ACROSS EASTERN PORTIONS. .LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY) ISSUED AT 135 PM MST MON DEC 8 2014 OLD FRONTAL BOUNDARY WILL RETURN EAST AS WARM FRONT AND STALL OUT ACROSS THE FORECAST AREA TUESDAY NIGHT. EAST OF THE FRONT...LOW LEVELS WILL SATURATE OVERNIGHT SETTING THE STAGE FOR AREAS OF FOG AND DRIZZLE. SURFACE WET BULB TEMPERATURES WILL BE IN THE LOWER 30S EAST OF THE BOUNDARY SO CANNOT TOTALLY RULE OUT FREEZING DRIZZLE. NAM SOUNDINGS ARE CONSIDERABLY MORE MOIST OVER A DEEPER LAYER COMPARED TO THE GFS SOUNDINGS...BUT EVEN IN THAT SCENARIO ACCUMULATION WOULD ONLY BE A FEW HUNDREDTHS OF AN INCH. NONETHELESS...WILL NEED TO MONITOR FOR POTENTIAL HIGHLIGHT FOR FREEZING DRIZZLE. CLOUDS WILL SLOWLY ERODE WEST TO EAST WEDNESDAY AFTERNOON...WITH EASTERN COUNTIES OF NORTHWEST KANSAS SUCH AS NORTON AND GRAHAM POSSIBLY STUCK IN THE CLOUDS ALL DAY AND WILL TREND MAX TEMPERATURES DOWN IN THOSE AREAS. CLOUDS WILL START TO RETURN WEST WEDNESDAY NIGHT WITH AREAS OF FOG AND DRIZZLE DEVELOPING ONCE AGAIN. THERE IS A NARROW BAND ON THE WESTERN EDGE OF THE MOISTURE WHERE SURFACE WET BULBS DIP BELOW FREEZING AND WILL CARRY A MENTION OF FREEZING DRIZZLE IN THOSE AREAS. CLOUDS WILL ERODE WEST TO EAST A LITTLE MORE QUICKLY ON FRIDAY WITH SUNNY SKIES BY THE AFTERNOON AND WARMER TEMPERATURES UNDER SHORTWAVE RIDGING ALOFT. A STRONG SYSTEM WILL MOVE OUT OF THE SOUTHERN ROCKIES LATE WEEK AND EJECT ACROSS THE SOUTHERN PLAINS OVER THE WEEKEND. THIS TRACK WILL BE TOO FAR SOUTH TO BRING PRECIPITATION CHANCES TO THE HIGH PLAINS AND HAVE GONE WITH A DRY FORECAST. HOWEVER ASSOCIATED SURFACE COLD FRONT WILL BRING COLDER TEMPERATURES SUNDAY AND MONDAY WITH HIGHS IN THE 40S AND LOWS IN THE TEENS AND 20S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1000 PM MST MON DEC 8 2014 KGLD...VFR THROUGH 12Z WITH WINDS UNDER 5KTS AND A FEW HIGH CLOUDS. A FEW STRATUS CLOUDS MAY BE SEEN EAST OF THE TERMINAL AROUND 12Z-13Z BECOMING BKN OVER THE TERMINAL WITH SOME BR AND REDUCED VISIBILITIES IN THE 14Z-16Z TIME FRAME. IFR CONDITIONS ARE EXPECTED. UNDER A SCATTERED TO BROKEN LAYER OF CIRRUS FROM 19Z THROUGH 04Z WINDS GENERALLY FROM THE SOUTH TO SOUTHEAST AROUND 11KTS VEERING TO THE SOUTHWEST AROUND 7KTS FROM 05Z-06Z. KMCK...VFR THROUGH 09Z WITH WINDS UNDER 5KTS AND A FEW HIGH CLOUDS. FROM 09Z THROUGH 18Z VLIFR CIGS/VIS EXPECTED TO MOVE IN FROM THE NORTHEAST WITH LIGHT/VARIABLE WINDS. AROUND 19Z THROUGH THE REST OF THE TAF PERIOD STRATUS EXPECTED TO THIN OUT ENOUGH TO PRODUCE VFR CONDITIONS WITH ONLY A LAYER OF CIRRUS AND SOUTHEAST/EAST-SOUTHEAST WINDS AROUND 5KTS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...DENSE FOG ADVISORY FROM 5 AM TO 11 AM CST TUESDAY FOR KSZ002>004- 014>016-028-029. CO...NONE. NE...DENSE FOG ADVISORY FROM 4 AM MST /5 AM CST/ TO 10 AM MST /11 AM CST/ TUESDAY FOR NEZ079>081. && $$ UPDATE...99 SHORT TERM...JN LONG TERM...024 AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
925 PM MST MON DEC 8 2014 .UPDATE... ISSUED AT 925 PM MST MON DEC 8 2014 HAVE ISSUED A DENSE FOG ADVISORY FOR AREAS GENERALLY EAST OF A LINE FROM TRENTON TO BREWSTER TO RUSSELL SPRINGS. 03Z RUC SIMILAR TO LATEST HRRR OUTPUT AND 00Z NAM BOOSTING CONFIDENCE THAT DENSE FOG WILL DEVELOP. UPDATE ISSUED AT 745 PM MST MON DEC 8 2014 UPDATES REQUIRED FOR FIRST AND SECOND PERIODS (TONIGHT AND TUESDAY) FOCUSING ON ARRIVAL OF POTENTIALLY DENSE FOG AND LOWER TEMPERATURES THEN PREVIOUSLY FORECAST. AT 0230Z CIRRUS SHIELD THAT WAS OVER THE AREA MOST OF THE DAY IS MOVING EAST AND SLOWLY OUT OF THE AREA. AM EXPECTING MORE TO MOVE IN LATER IN THE EVENING AND THROUGH THE DAY TOMORROW FROM THE NORTHWEST. AT THE SFC STRATUS PER SATELLITE OBS AND RUC 900MB RH FORECAST CURRENTLY OVER NORTHEAST NEBRASKA/SOUTHWEST IOWA. BY 06Z THIS NARROW CORRIDOR OF STRATUS FORECAST TO POSSIBLY REACH AREAS JUST TO THE NORTHEAST FROM MCCOOK TO NORTON. AS SFC HIGH CONTINUES TO BACK INTO THE AREA WITH LIGHT NORTHEAST WINDS STRATUS DECK EXPECTED TO REACH A TRENTON TO HILL CITY LINE BY 09Z THEN ROUGHLY A BENKELMAN TO COLBY AND OAKLEY LINE BY 12Z. IN THE TRENTON TO HILL CITY AND POINTS NORTHEAST AREAS WINDS ARE CALM AND RH NEAR 100 PERCENT. LATEST RUC/HRRR/NAM VISIBILITY FORECASTS ALL SHOWING DENSE FOG WITH VISIBILITIES 1/4 MILE OR LESS. NAM EXTRAPOLATION OF SATURATED BOUNDARY LAYER RH PUSHES IT FURTHER WEST TOWARD THE CO/KS BORDER WITH DENSE FOG CONTINUING ROUGHLY FROM TRENTON TO HOXIE AND POINTS EAST. HRRR SUGGESTS FURTHER WEST TOWARD BENKELMAN TO NEAR GOODLAND AND RUSSELL SPRINGS. WILL AWAIT THE 03Z RUC/LATEST HRRR BEFORE ZONE UPDATE SENT BUT HAVE TRENDED TOWARD ABOVE THINKING. && .SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY) ISSUED AT 119 PM MST MON DEC 8 2014 DECENT AFTERNOON ACROSS THE ENTIRE FORECAST AREA...AS THE TRI STATE REGION IS SEEING TEMPERATURES 15 TO 20 DEGREES ABOVE NORMAL WITH READINGS WELL INTO THE 50S. THIS IS ONGOING DESPITE HIGH CLOUDS MOVING OVER THE AREA CREATING SUNNY CONDITIONS. HIGH CLOUD COVER WILL SCATTER OUT DURING THE EARLY EVENING HOURS IN TIME FOR 925MB THERMAL BOUNDARY/SURFACE RIDGE AXIS COMBO...WHICH MODELS BRING OVER THE REGION BY MIDNIGHT TONIGHT. MODEL RH IN LATEST BUFKIT RUNS DOES HINT AT FOG/LOW STRATUS FORMATION BETWEEN 06Z-14Z TUESDAY...WITH BEST CHANCES OVER IN CENTRAL AND EASTERN ZONES. LGT/VAR WIND CONDITIONS WILL ALSO AID IN FOG FORMATION IN THE AFOREMENTIONED ZONES...SO WILL KEEP PREVIOUS MENTION OF FOG IN THE FORECAST. GOING INTO TUESDAY...SURFACE HIGH PRESSURE SETTLES OVER CENTRAL AND EASTERN PLAINS. THIS IS GOING TO SET UP YET ANOTHER NICE DAY FOR MUCH OF THE CWA. MUCH OF THE WESTERN CWA WILL SEE WAA AGAIN ON SOUTHERLY FLOW...WHILE EASTERN ZONES WILL BE CLOSE ENOUGH TO SURFACE RIDGE THAT WINDS WILL NOT BE MAJOR FACTOR...SO HAVE TAPERED HIGHS FOR TOMORROW FROM WEST TO EAST...MID 50S WEST DOWN TO THE MID 40S ACROSS EASTERN PORTIONS. .LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY) ISSUED AT 135 PM MST MON DEC 8 2014 OLD FRONTAL BOUNDARY WILL RETURN EAST AS WARM FRONT AND STALL OUT ACROSS THE FORECAST AREA TUESDAY NIGHT. EAST OF THE FRONT...LOW LEVELS WILL SATURATE OVERNIGHT SETTING THE STAGE FOR AREAS OF FOG AND DRIZZLE. SURFACE WET BULB TEMPERATURES WILL BE IN THE LOWER 30S EAST OF THE BOUNDARY SO CANNOT TOTALLY RULE OUT FREEZING DRIZZLE. NAM SOUNDINGS ARE CONSIDERABLY MORE MOIST OVER A DEEPER LAYER COMPARED TO THE GFS SOUNDINGS...BUT EVEN IN THAT SCENARIO ACCUMULATION WOULD ONLY BE A FEW HUNDREDTHS OF AN INCH. NONETHELESS...WILL NEED TO MONITOR FOR POTENTIAL HIGHLIGHT FOR FREEZING DRIZZLE. CLOUDS WILL SLOWLY ERODE WEST TO EAST WEDNESDAY AFTERNOON...WITH EASTERN COUNTIES OF NORTHWEST KANSAS SUCH AS NORTON AND GRAHAM POSSIBLY STUCK IN THE CLOUDS ALL DAY AND WILL TREND MAX TEMPERATURES DOWN IN THOSE AREAS. CLOUDS WILL START TO RETURN WEST WEDNESDAY NIGHT WITH AREAS OF FOG AND DRIZZLE DEVELOPING ONCE AGAIN. THERE IS A NARROW BAND ON THE WESTERN EDGE OF THE MOISTURE WHERE SURFACE WET BULBS DIP BELOW FREEZING AND WILL CARRY A MENTION OF FREEZING DRIZZLE IN THOSE AREAS. CLOUDS WILL ERODE WEST TO EAST A LITTLE MORE QUICKLY ON FRIDAY WITH SUNNY SKIES BY THE AFTERNOON AND WARMER TEMPERATURES UNDER SHORTWAVE RIDGING ALOFT. A STRONG SYSTEM WILL MOVE OUT OF THE SOUTHERN ROCKIES LATE WEEK AND EJECT ACROSS THE SOUTHERN PLAINS OVER THE WEEKEND. THIS TRACK WILL BE TOO FAR SOUTH TO BRING PRECIPITATION CHANCES TO THE HIGH PLAINS AND HAVE GONE WITH A DRY FORECAST. HOWEVER ASSOCIATED SURFACE COLD FRONT WILL BRING COLDER TEMPERATURES SUNDAY AND MONDAY WITH HIGHS IN THE 40S AND LOWS IN THE TEENS AND 20S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 400 PM MST MON DEC 8 2014 KGLD...VFR THROUGH 10Z WITH WINDS 5KTS OR LESS UNDER A LAYER OF CIRRUS. FROM 11Z-17Z STRATUS/BR MOVE IN FROM THE NORTHEAST BRINGING A PERIOD OF POSSIBLY IFR CIGS AND SOME REDUCED VISIBILITIES. FROM 18Z THROUGH THE REST OF THE TAF PERIOD WINDS FROM THE SOUTH NEAR 11KTS WITH BKN LAYER OF CIRRUS. KMCK...VFR THROUGH 07Z WITH WINDS 5KTS OR LESS UNDER A LAYER OF CIRRUS. FROM 08Z THROUGH 18Z IFR/VLIFR CIGS/VIS EXPECTED TO MOVE IN FROM THE NORTHEAST WITH LIGHT/VARIABLE WINDS. AROUND 19Z STRATUS EXPECTED TO THIN OUT ENOUGH TO PRODUCE VFR CONDITIONS WITH ONLY A LAYER OF CIRRUS AND SOUTHEAST/EAST-SOUTHEAST WINDS AROUND 5KTS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...DENSE FOG ADVISORY FROM 5 AM TO 11 AM CST TUESDAY FOR KSZ002>004- 014>016-028-029. CO...NONE. NE...DENSE FOG ADVISORY FROM 4 AM MST /5 AM CST/ TO 10 AM MST /11 AM CST/ TUESDAY FOR NEZ079>081. && $$ UPDATE...99 SHORT TERM...JN LONG TERM...024 AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
245 AM EST TUE DEC 9 2014 .UPDATE... ISSUED AT 1058 PM EST MON DEC 8 2014 THE SPOTTY RADAR RETURNS AND ANY SPRINKLES ASSOCIATED WITH THEM HAVE LIFTED NORTH AND EAST OF THE AREA. BETTER RETURNS ARE OCCURRING UPSTREAM IN SOUTHERN INDIANA CLOSER TO THE APPROACHING COLD FRONT AND MID-LEVEL SHORT WAVE TROUGH. HAVE REMOVED THE MENTION OF SPRINKLES FROM THE FORECAST AT THIS POINT...AWAITING THE MORE SUBSTANTIAL SHOWERS FROM THE NORTHWEST. SOME OF THE SHELTERED VALLEYS HAVE TAKEN ADVANTAGE OF SOME CLOUD THINNING CURRENTLY MOVING ACROSS THE AREA...WITH THE BREATHITT COUNTY MESONET REPORTING 33 DEGREES AT THIS TIME. HAVE TRIED TO REFLECT SIMILAR SPOTS LIKELY DIPPING INTO THE LOW TO MID 30S HOWEVER...AS THE THICKER BLANKET OF LOWER CLOUDS MOVES IN FROM THE WEST...EXPECT THESE READINGS TO WARM UP. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 730 PM EST MON DEC 8 2014 THE SURFACE WARM FRONT ASSOCIATED WITH THE GREAT LAKES LOW PRESSURE SYSTEM IS CURRENTLY MOVING THROUGH EASTERN KENTUCKY. MOST OF THE RADAR RETURNS HAVE ONLY RESULTED IN SOME SPOTTY SPRINKLES THUS FAR AND THE LATEST HRRR ONLY SUPPORTS THIS UNTIL THE COLD FRONT ARRIVES LATER TONIGHT INTO EARLY TUESDAY MORNING. AS SUCH...HAVE DIALED BACK THE POPS A BIT FOR THE FIRST HALF OF THE NIGHT AND WILL ONLY CONTINUE TO MENTION A FEW SPRINKLES POSSIBLE. TEMPERATURES ARE CURRENTLY RUNNING IN THE LOW TO MID 40S FOR MOST LOCATIONS...HOWEVER A FEW SPOTS HAVE DIPPED INTO THE UPPER 30S. BLACK MOUNTAIN AND THE PIKE COUNTY MESONET HAVE BEEN HOVERING IN THE LOW TO MID 30S. THE LATEST MODEL GUIDANCE SUPPORTS TEMPERATURES AT THESE HIGHER ELEVATIONS TO REMAIN STEADY IF NOT FALL A BIT...ESPECIALLY TOWARDS DAWN WHEN THE PRECIP THREATENS. AS SUCH...WILL MENTION A CHANCE OF SNOW SHOWERS FOR ELEVATIONS ABOVE 2500 FEET. HAVE ADJUSTED THE TEMPERATURE CURVE FOR THESE LOCATIONS ALL THE WAY THROUGH THE DAY ON TUESDAY...AS READINGS WILL CONTINUE TO SLIDE THROUGH THE DAY. UPDATES WILL BE FORTHCOMING. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 359 PM EST MON DEC 8 2014 A DEEPENING TROUGH IS CURRENTLY SWEEPING ACROSS THE EASTERN CONUS...WITH A UPPER LEVEL SHORT WAVE EXPECTED TO MOVE SE ACROSS EASTERN KY BETWEEN 12 AND 18Z TUESDAY. AT THE SURFACE...AN AREA OF LOW PRESSURE IS CURRENTLY TRAVERSING LAKE SUPERIOR. A COLD FRONT AND WARM FRONT ARE EXTENDING SOUTHWARD FROM THIS LOW...WITH THE WARM FRONT HAVING JUST MOVED FROM SW TO NE ACROSS THE CWA...AND THE COLD FRONT EXPECTED TO TRAVERSE KY BETWEEN 6Z AND 12Z TONIGHT /MAY LINGER A BIT LONGER IN THE FAR SE/. WINDS REMAIN GENERALLY SRLY AS OF THIS AFTERNOON IN EASTERN KY...WITH TEMP READINGS IN THE MID 40S TO AROUND 50 AT PRESENT TIME. /THE CAVEAT TO THAT IS THE HIGHEST TERRAIN WHICH IS CURRENTLY ONLY IN THE MID AND UPPER 30S. MOISTURE AHEAD OF THE APPROACHING COLD FRONT IS CONTINUING TO ADVECT INTO THE REGION. THICK HIGH CLOUDS WILL CONTINUE TO LOWER THROUGHOUT THE EVENING AND OVERNIGHT AS MOISTURE WORKS ITS WAY DOWN TO THE SURFACE. AN AREA OF RADAR RETURNS IS CURRENTLY MOVING ACROSS CENTRAL KY AND TN...TREKKING EASTWARD TOWARDS THE JKL CWA. WHILE RETURNS HAVE LESSENED OVER THE LAST FEW HOURS...THE AMOUNT OF DRY AIR AT THE SURFACE THROUGHOUT THE MORNING/EARLY AFTERNOON HAS KEPT ANY OF THE RAIN FROM REACHING THE GROUND ACROSS KY. WENT AHEAD AND INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHERN CWA BY 0Z AS THIS AREA MOVES INTO OUR REGION...JUST IN CASE SOME LIGHT SHOWER IS ABLE TO BREAK THROUGH TO THE SURFACE. AS LOW LEVEL MOISTURE FINALLY BEGINS TO TAKE HOLD OVERNIGHT...EXPECT THE BEST CHANCES FOR RAIN TO BEGIN FILLING INTO EASTERN KY AFTER 6Z OVERNIGHT. THERE WILL BE AN ABUNDANT AMOUNT OF DRY AIR ALOFT...WITH ONLY A SHALLOW LAYER OF LOW/MID LEVEL MOISTURE TO WORK WITH DURING THIS EVENT. AS SUCH...ONLY WARRANTED CHANCE POPS AT THIS TIME...WITH SCATTERED SHOWERS EXPECTED OPPOSED TO A WIDESPREAD RAIN EVENT. THERE IS SOME QUESTION ABOUT THE PRECIP TYPE DURING THIS EVENT. UNFORTUNATELY IT IS NOT A CUT AND DRY SITUATION. A FEW DEGREES DIFFERENCE IN THE FIRST 1000 FEET COULD MAKE THE DIFFERENCE IN SNOW OR RAIN. AS OF NOW...MOISTURE IS CONFINED TO 8K FT AND BELOW...WITH NEARLY ALL OF THAT MOISTURE BELOW -10C HAVING NO INFLUENCE BY THE DENDRITIC GROWTH ZONE. THIS WOULD FAVOR LITTLE IN THE WAY OF SNOWFLAKE FORMATION. HOWEVER...TEMPS ARE BELOW FREEZING IN MUCH OF THE MOIST LAYER...EXCEPT RIGHT AT THE LOWEST 1000 FT. SO IF THERE IS ANY ICE/SNOW PELLETS...IT IS POSSIBLE THAT THEY MAY MELT ON THE WAY DOWN TO THE SURFACE. OR...AS TEMPS OVERNIGHT AND ON THE HIGHEST TERRAIN TOMORROW DIP DOWN SLIGHTLY...IT IS POSSIBLE THAT SOME SNOW/ICE PELLETS MAY MELT AND SOME MAY NOT...MAKING IT POSSIBLE FOR A MIXTURE OF SNOW AND ICE. TRIED TO STAY MORE OPTIMISTIC FOR THE NEXT 24 HOURS...WITH MAINLY RAIN CHANCES ACROSS THE REGION...EXCEPT IN PLACES ABOVE 1300 FEET THAT WILL EXPERIENCE SURFACE TEMPERATURES NEAR OR JUST ABOVE FREEZING. BY TOMORROW NIGHT...WHILE ALL OF THE ABOVE HOLDS TRUE...COLDER NE AIR BEHIND THE FRONTAL BOUNDARY WILL BEGIN PULLING INTO THE REGION. THIS MAY BE ENOUGH TO DROP TEMPS CLOSER TO THAT FREEZING MARK AND SLIGHTLY BELOW...ALLOWING MORE SNOW TO MIX IN WITH THE RAIN...OR IN A FEW PLACES...FALL AS SNOW ONLY. STILL...GIVEN THE WET AND SLIGHTLY WARMER SURFACE TEMPS...THE ONLY SNOW ACCUMULATIONS AT THIS POINT ARE IN THE HIGHEST TERRAIN AROUND BLACK MOUNTAIN TUESDAY NIGHT/WEDNESDAY MORNING. DRY AIR ALOFT WILL CONTINUE TO INCREASE THROUGHOUT THE OVERNIGHT HOURS...ESPECIALLY JUST BEHIND THE INITIAL COLD FRONTAL PASSAGE. THIS WILL WORK TO MAKE THE LAYER OF MOISTURE EVEN SHALLOWER...WHILE A IMPRESSIVELY STRONG INVERSION TAKES HOLD IN THE MID LEVELS. AS SUCH...IT IS STILL BORDERLINE AND SOMEWHAT UNCLEAR AS TO IF THE PRECIP THAT FALLS TUESDAY NIGHT WILL BE LIGHT RAIN/SNOW...OR MAYBE A WINTRY DRIZZLE. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 245 AM EST TUE DEC 9 2014 THE MODELS ARE IN FAIRLY GOOD AGREEMENT ALOFT FOR THE BULK OF THE EXTENDED AS THEY SLOWLY DRIFT THE LARGE EASTERN LOW AWAY FROM KENTUCKY INTO THE UPCOMING WEEKEND. THIS BLOCKING LOW WILL KEEP THE WX QUIET OVER THE OHIO VALLEY FOR THE MAJORITY OF THE EXTENDED PORTION OF THE FORECAST. HOWEVER...SOME LINGERING CYCLONIC FLOW OVER THE CENTRAL APPALACHIANS AND A WAVE SLIPPING PAST KENTUCKY TO THE SOUTH MAY HAVE A FLEETING EFFECT ON SENSIBLE WEATHER WEDNESDAY NIGHT IN THE FAR EAST. OTHERWISE...THROUGH SUNDAY...HEIGHT RISES AND AN ABSENCE OF MID LEVEL ENERGY IN THE WAKE OF THE EASTERN LOW WILL KEEP THINGS QUIET ACROSS EASTERN KENTUCKY. BY SUNDAY...A RELATIVELY STRONG RIDGE WILL BE LOCATED OVER THE AREA IN ALL THE MODELS WITH THE ECMWF PREFERRED OWING TO ITS SLOWER EXIT OF THE EASTERN TROUGH IN THIS BLOCKY PATTERN. THIS RIDGE WILL SWEEP EAST OF THE STATE LATER MONDAY AHEAD OF A CLOSED SOUTHERN STREAM LOW MOVING THROUGH THE SOUTHERN PLAINS...IN CONJUNCTION WITH A NORTHERN CENTER FOUND JUST NORTH OF THE CANADIAN BORDER. THIS SOLUTION IS PREFERRED COMPARED TO THE GFS/S AS IT DOES A BETTER JOB OF KEEPING ITS STREAMS SEPARATE AND SLOWER. SENSIBLE WEATHER MAY FEATURE SOME LINGERING LIGHT SNOW SHOWERS/ FLURRIES OVER THE HIGHEST TERRAIN IN THE FAR EASTERN PARTS OF KENTUCKY. A GRADUALLY MODERATING BUBBLE OF HIGH PRESSURE THEN SETTLES OVER THE AREA AND HOLDS QUIET AND SEASONABLY PLEASANT WX IN PLACE THROUGH THE WEEKEND. THE ECMWF/S IDEA OF A SFC LOW COMING OUT OF THE SOUTHERN PLAINS FOR LATER MONDAY SEEMS REASONABLE...BUT THIS WOULD KEEP EASTERN KENTUCKY DRY UNTIL PERHAPS LATER MONDAY NIGHT INTO NEXT TUESDAY IN CONTRAST TO THE GFS/S VERSION OF A WEAKENING COLD FRONT PASSING THROUGH THE STATE BY 00Z TUESDAY. HAVE GONE CLOSER TO THE ECMWF FOR THIS TIME FRAME. THE CR GRID LOAD PROVIDED A DECENT START FOR THE EXTENDED FORECAST WITH CHANGES MAINLY MADE TO BETTER REFLECT THE LATEST ECMWF SOLUTION IN THE LATTER PART OF THE FORECAST VIA LOWER POPS ON MONDAY. ALSO MADE SOME TYPICAL RIDGE AND VALLEY TEMPERATURE CHANGES FOR LOWS EACH NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1233 AM EST TUE DEC 9 2014 VFR CONDITIONS WILL BE IN PLACE TO BEGIN THE TAF PERIOD...AND THEN A PASSING COLD FRONT WILL ALLOW FOR MVFR TO IFR CEILINGS TO FILL IN FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA BETWEEN 06 AND 12Z. LIGHT PRECIPITATION WILL ALSO ACCOMPANY THE FRONT...WITH MOST OF THIS PRECIPITATION OCCURRING BETWEEN 12 AND 18Z TUESDAY. CEILINGS MAY THEN RAISE A BIT INTO THE AFTERNOON...WITH THE EXCEPTION OF THE FAR SOUTHEAST...WHERE MORE SUSTAINED RAIN AND OR SNOW SHOWERS WILL CONTINUE TO BE SEEN THROUGH TUESDAY EVENING. SOUTHEAST TO SOUTH WINDS OF AROUND 5 KTS WILL VEER AROUND TO THE NORTHWEST AND INCREASE TO AROUND 10 KTS BY EARLY THIS MORNING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JMW LONG TERM...GREIF AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
1233 AM EST TUE DEC 9 2014 .UPDATE... ISSUED AT 1058 PM EST MON DEC 8 2014 THE SPOTTY RADAR RETURNS AND ANY SPRINKLES ASSOCIATED WITH THEM HAVE LIFTED NORTH AND EAST OF THE AREA. BETTER RETURNS ARE OCCURRING UPSTREAM IN SOUTHERN INDIANA CLOSER TO THE APPROACHING COLD FRONT AND MID-LEVEL SHORT WAVE TROUGH. HAVE REMOVED THE MENTION OF SPRINKLES FROM THE FORECAST AT THIS POINT...AWAITING THE MORE SUBSTANTIAL SHOWERS FROM THE NORTHWEST. SOME OF THE SHELTERED VALLEYS HAVE TAKEN ADVANTAGE OF SOME CLOUD THINNING CURRENTLY MOVING ACROSS THE AREA...WITH THE BREATHITT COUNTY MESONET REPORTING 33 DEGREES AT THIS TIME. HAVE TRIED TO REFLECT SIMILAR SPOTS LIKELY DIPPING INTO THE LOW TO MID 30S HOWEVER...AS THE THICKER BLANKET OF LOWER CLOUDS MOVES IN FROM THE WEST...EXPECT THESE READINGS TO WARM UP. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 730 PM EST MON DEC 8 2014 THE SURFACE WARM FRONT ASSOCIATED WITH THE GREAT LAKES LOW PRESSURE SYSTEM IS CURRENTLY MOVING THROUGH EASTERN KENTUCKY. MOST OF THE RADAR RETURNS HAVE ONLY RESULTED IN SOME SPOTTY SPRINKLES THUS FAR AND THE LATEST HRRR ONLY SUPPORTS THIS UNTIL THE COLD FRONT ARRIVES LATER TONIGHT INTO EARLY TUESDAY MORNING. AS SUCH...HAVE DIALED BACK THE POPS A BIT FOR THE FIRST HALF OF THE NIGHT AND WILL ONLY CONTINUE TO MENTION A FEW SPRINKLES POSSIBLE. TEMPERATURES ARE CURRENTLY RUNNING IN THE LOW TO MID 40S FOR MOST LOCATIONS...HOWEVER A FEW SPOTS HAVE DIPPED INTO THE UPPER 30S. BLACK MOUNTAIN AND THE PIKE COUNTY MESONET HAVE BEEN HOVERING IN THE LOW TO MID 30S. THE LATEST MODEL GUIDANCE SUPPORTS TEMPERATURES AT THESE HIGHER ELEVATIONS TO REMAIN STEADY IF NOT FALL A BIT...ESPECIALLY TOWARDS DAWN WHEN THE PRECIP THREATENS. AS SUCH...WILL MENTION A CHANCE OF SNOW SHOWERS FOR ELEVATIONS ABOVE 2500 FEET. HAVE ADJUSTED THE TEMPERATURE CURVE FOR THESE LOCATIONS ALL THE WAY THROUGH THE DAY ON TUESDAY...AS READINGS WILL CONTINUE TO SLIDE THROUGH THE DAY. UPDATES WILL BE FORTHCOMING. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 359 PM EST MON DEC 8 2014 A DEEPENING TROUGH IS CURRENTLY SWEEPING ACROSS THE EASTERN CONUS...WITH A UPPER LEVEL SHORT WAVE EXPECTED TO MOVE SE ACROSS EASTERN KY BETWEEN 12 AND 18Z TUESDAY. AT THE SURFACE...AN AREA OF LOW PRESSURE IS CURRENTLY TRAVERSING LAKE SUPERIOR. A COLD FRONT AND WARM FRONT ARE EXTENDING SOUTHWARD FROM THIS LOW...WITH THE WARM FRONT HAVING JUST MOVED FROM SW TO NE ACROSS THE CWA...AND THE COLD FRONT EXPECTED TO TRAVERSE KY BETWEEN 6Z AND 12Z TONIGHT /MAY LINGER A BIT LONGER IN THE FAR SE/. WINDS REMAIN GENERALLY SRLY AS OF THIS AFTERNOON IN EASTERN KY...WITH TEMP READINGS IN THE MID 40S TO AROUND 50 AT PRESENT TIME. /THE CAVEAT TO THAT IS THE HIGHEST TERRAIN WHICH IS CURRENTLY ONLY IN THE MID AND UPPER 30S. MOISTURE AHEAD OF THE APPROACHING COLD FRONT IS CONTINUING TO ADVECT INTO THE REGION. THICK HIGH CLOUDS WILL CONTINUE TO LOWER THROUGHOUT THE EVENING AND OVERNIGHT AS MOISTURE WORKS ITS WAY DOWN TO THE SURFACE. AN AREA OF RADAR RETURNS IS CURRENTLY MOVING ACROSS CENTRAL KY AND TN...TREKKING EASTWARD TOWARDS THE JKL CWA. WHILE RETURNS HAVE LESSENED OVER THE LAST FEW HOURS...THE AMOUNT OF DRY AIR AT THE SURFACE THROUGHOUT THE MORNING/EARLY AFTERNOON HAS KEPT ANY OF THE RAIN FROM REACHING THE GROUND ACROSS KY. WENT AHEAD AND INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHERN CWA BY 0Z AS THIS AREA MOVES INTO OUR REGION...JUST IN CASE SOME LIGHT SHOWER IS ABLE TO BREAK THROUGH TO THE SURFACE. AS LOW LEVEL MOISTURE FINALLY BEGINS TO TAKE HOLD OVERNIGHT...EXPECT THE BEST CHANCES FOR RAIN TO BEGIN FILLING INTO EASTERN KY AFTER 6Z OVERNIGHT. THERE WILL BE AN ABUNDANT AMOUNT OF DRY AIR ALOFT...WITH ONLY A SHALLOW LAYER OF LOW/MID LEVEL MOISTURE TO WORK WITH DURING THIS EVENT. AS SUCH...ONLY WARRANTED CHANCE POPS AT THIS TIME...WITH SCATTERED SHOWERS EXPECTED OPPOSED TO A WIDESPREAD RAIN EVENT. THERE IS SOME QUESTION ABOUT THE PRECIP TYPE DURING THIS EVENT. UNFORTUNATELY IT IS NOT A CUT AND DRY SITUATION. A FEW DEGREES DIFFERENCE IN THE FIRST 1000 FEET COULD MAKE THE DIFFERENCE IN SNOW OR RAIN. AS OF NOW...MOISTURE IS CONFINED TO 8K FT AND BELOW...WITH NEARLY ALL OF THAT MOISTURE BELOW -10C HAVING NO INFLUENCE BY THE DENDRITIC GROWTH ZONE. THIS WOULD FAVOR LITTLE IN THE WAY OF SNOWFLAKE FORMATION. HOWEVER...TEMPS ARE BELOW FREEZING IN MUCH OF THE MOIST LAYER...EXCEPT RIGHT AT THE LOWEST 1000 FT. SO IF THERE IS ANY ICE/SNOW PELLETS...IT IS POSSIBLE THAT THEY MAY MELT ON THE WAY DOWN TO THE SURFACE. OR...AS TEMPS OVERNIGHT AND ON THE HIGHEST TERRAIN TOMORROW DIP DOWN SLIGHTLY...IT IS POSSIBLE THAT SOME SNOW/ICE PELLETS MAY MELT AND SOME MAY NOT...MAKING IT POSSIBLE FOR A MIXTURE OF SNOW AND ICE. TRIED TO STAY MORE OPTIMISTIC FOR THE NEXT 24 HOURS...WITH MAINLY RAIN CHANCES ACROSS THE REGION...EXCEPT IN PLACES ABOVE 1300 FEET THAT WILL EXPERIENCE SURFACE TEMPERATURES NEAR OR JUST ABOVE FREEZING. BY TOMORROW NIGHT...WHILE ALL OF THE ABOVE HOLDS TRUE...COLDER NE AIR BEHIND THE FRONTAL BOUNDARY WILL BEGIN PULLING INTO THE REGION. THIS MAY BE ENOUGH TO DROP TEMPS CLOSER TO THAT FREEZING MARK AND SLIGHTLY BELOW...ALLOWING MORE SNOW TO MIX IN WITH THE RAIN...OR IN A FEW PLACES...FALL AS SNOW ONLY. STILL...GIVEN THE WET AND SLIGHTLY WARMER SURFACE TEMPS...THE ONLY SNOW ACCUMULATIONS AT THIS POINT ARE IN THE HIGHEST TERRAIN AROUND BLACK MOUNTAIN TUESDAY NIGHT/WEDNESDAY MORNING. DRY AIR ALOFT WILL CONTINUE TO INCREASE THROUGHOUT THE OVERNIGHT HOURS...ESPECIALLY JUST BEHIND THE INITIAL COLD FRONTAL PASSAGE. THIS WILL WORK TO MAKE THE LAYER OF MOISTURE EVEN SHALLOWER...WHILE A IMPRESSIVELY STRONG INVERSION TAKES HOLD IN THE MID LEVELS. AS SUCH...IT IS STILL BORDERLINE AND SOMEWHAT UNCLEAR AS TO IF THE PRECIP THAT FALLS TUESDAY NIGHT WILL BE LIGHT RAIN/SNOW...OR MAYBE A WINTRY DRIZZLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 410 PM EST MON DEC 8 2014 AN UPPER LEVEL LOW WILL MEANDER OF THE MID ATLANTIC STATES INTO THE START OF THE WEEKEND. A SHORTWAVE TROUGH ROTATING AROUND THIS UPPER LOW WILL WORK ACROSS EASTERN KY ON WED. ONCE THIS SYSTEM DEPARTS...GRADUALLY RISING HEIGHTS ARE ANTICIPATED FROM THU INTO SAT ACROSS ACROSS THE LOWER OH VALLEY AND EASTERN KY AS AN UPPER LEVEL RIDGE BUILDS INTO MUCH OF THE EASTERN CONUS. THIS RIDGE WILL GRADUALLY DEPART LATE IN THE PERIOD...EARLY NEXT WEEK AND ALLOW AN UPPER LEVEL TROUGH TO MOVE INTO THE EASTERN CONUS. MODEL AGREEMENT INTO THE WEEKEND AND EARLY NEXT WEEK IS ABOVE AVERAGE WITH THE GENERAL PATTERN. THIS PATTERN WILL FAVOR BELOW NORMAL TEMPERATURES FROM WED INTO FRI AS HIGH PRESSURE BUILDS ACROSS THE AREA. AS FOR THE START OF THE PERIOD...MODELS HOLD ONTO SOME SHALLOW MOISTURE AND UPSLOPE FLOW...BUT LAPSE RATES ARE NOT ALL THAT IMPRESSIVE AND THE INVERSION HEIGHT IS NOT MUCH ABOVE THE -10C LEVEL AS WELL. MODELS ALSO HAVE SOME DIFFERENCES AND ICE MAY NOT BE PRESENT IN THE CLOUDS AT TIMES...ALTHOUGH MOISTURE SHOULD BE DEEPER FROM 12Z TO 18Z...AND POSSIBLY LONGER ON WED. THE GFS OVERALL SHOWS A BETTER POTENTIAL FOR ICE WITH MORE SATURATION IN THE -8C TO -10C LEVELS OR HIGHER. THE BULK OF WHAT SNOW THAT DOES FALL SHOULD NOT BE DENDRITES...BUT THE HIGHER ELEVATIONS AT 2000 FEET AND ABOVE SHOULD REMAIN AT OR BELOW FREEZING ON WED AND COULD RECEIVE SOME LIGHT ACCUMULATIONS. AS WITH MOST NW FLOW EVENTS...THERE IS SOME QUESTION AS TO WHEN THE MOISTURE AND CLOUDS WILL DEPART. AT THIS TIME...WE HAVE OPTED TO CONTINUE ON THE PESSIMISTIC SIDE WITH THE CLOUDS AND MOISTURE DEPARTURE AND HAVE CONTINUED TO HOLD ONTO SLIGHT CHANCE OF SNOW SHOWERS OR FLURRIES INTO WED EVENING. HOWEVER...AS THE SFC HIGH BEGINS TO SHIFT EAST OF THE AREA THIS WEEKEND...THE AIR MASS WILL MODERATE AND ABOVE NORMAL TEMPERATURES WILL ENSUE THROUGH THE END OF THE PERIOD. OTHER THAN THE START OF THE PERIOD...IT SHOULD BE DRY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1233 AM EST TUE DEC 9 2014 VFR CONDITIONS WILL BE IN PLACE TO BEGIN THE TAF PERIOD...AND THEN A PASSING COLD FRONT WILL ALLOW FOR MVFR TO IFR CEILINGS TO FILL IN FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA BETWEEN 06 AND 12Z. LIGHT PRECIPITATION WILL ALSO ACCOMPANY THE FRONT...WITH MOST OF THIS PRECIPITATION OCCURRING BETWEEN 12 AND 18Z TUESDAY. CEILINGS MAY THEN RAISE A BIT INTO THE AFTERNOON...WITH THE EXCEPTION OF THE FAR SOUTHEAST...WHERE MORE SUSTAINED RAIN AND OR SNOW SHOWERS WILL CONTINUE TO BE SEEN THROUGH TUESDAY EVENING. SOUTHEAST TO SOUTH WINDS OF AROUND 5 KTS WILL VEER AROUND TO THE NORTHWEST AND INCREASE TO AROUND 10 KTS BY EARLY THIS MORNING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JMW LONG TERM...JP AVIATION...AR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
347 AM EST TUE DEC 9 2014 .UPDATE... ISSUED AT 713 PM EST MON DEC 8 2014 LOW PRESSURE SLIDING OVER CNTRL UPR MICHIGAN AS OF 23Z. COLD AIR IN WAKE OF THE LOW SLOW TO ARRIVE. DEEP MOISTURE TIED INTO THE LOW HAS FADED QUICKLY AND LEFTOVER MOISTURE IS SHALLOW IN DEPTH AND TEMPS WITHIN THE MOIST LAYER ARE ONLY AS COOL AS -4C TO -6C OVER WESTERN LK SUPERIOR AND WESTERN CWA. VSBY AT IWD AND CMX HAS BEEN BLO 5SM SINCE SUNSET. REPORTS FM SOCIAL MEDIA INDICATE DRIZZLE OCCURRING OVER KEWEENAW AND LOWER ELEVATIONS OF ONTONAGON COUNTY. SOME SNOW FLURRIES ARE FALLING OVER HIGHER TERRAIN IN ONTONAGON COUNTY. ADDED PATCHY DZ/FZDZ TO GRIDS UNTIL AROUND 06Z FOR WEST/NORTHWEST AND INTO NCNTRL. RAP/NAM/GFS SOUNDINGS INDICATE AFTER 06Z IT BECOMES COLD ENOUGH FOR MIXED PRECIP TO CHANGE TO MAINLY SNOW. ADDED FOG TO MUCH OF EAST HALF OF CWA THROUGH THE EVENING WITH SOUTHERLY FLOW OVER LK MICHIGAN PUSHING DWPNTS IN LOW 30S OVER THE WET SNOW PACK FM THE SNOW THAT OCCURRED EARLIER TODAY. ALREADY SEEING VSBY BLO 2SM OVER MOST OF THE EAST PART OF THE CWA...INCLUDING VSBY DOWN TO 1/4SM IN THE LAST HOUR AT MNM. ONCE WINDS IN BLYR SHIFT TO NW LATER THIS EVENING...FOG SHOULD BEGIN TO LIFT AS MOISTENING FLOW OFF LK MICHIGAN WILL BE DIMINISHED. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 304 PM EST MON DEC 8 2014 LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS THE SHOW SHORTWAVE TROF MOVING ACROSS THE UPPER GREAT LAKES THIS AFTERNOON. MODELS INDICATE BEST ISENTROPIC ASCENT...MOISTURE TRANSPORT AND DEEP LAYER Q-VECT CONVERGENCE HAS SHIFTED EAST WITH MAIN SNOW BAND AHEAD OF THE SFC-8H TROF OVER CENTRAL UPPER MI. IT/S POSSIBLE THERE MAY BE SOME PATCHY -FZDZ LATE THIS AFTERNOON BEHIND THE SNOW BAND WITH MID-LVL DRYING AND LOW-LVL MOISTURE TOO SHALLOW TO REACH THE -10C ISOTHERM...BUT NOT SURE IF THE FZDZ WILL BE SIGNIFICANT ENOUGH TO INCLUDE IN FCST GRIDS THIS EVENING. MODELS INDICATE THAT N TO NW WINDS WILL STRENGTHEN TONIGHT BEHIND DEPARTING LOW PRES TONIGHT. COOLING LOW-LEVEL AIR MASS MAY SUPPORT SOME LAKE ENHANCED SNOW FOR A BRIEF TIME THIS EVENING. HOWEVER...SNOWFALL IS EXPECTED TO BE LIGHT FOR THE FOLLOWING REASONS...850MB TEMPS (AROUND -6C) ARE MARGINAL FOR ENHANCEMENT WHILE DEEPER MOISTURE IS AROUND...LOW-LEVEL FLOW IS NOT STRONGLY CYCLONIC...AND DGZ IS ABOVE THE UPWARD MOTION AND THE DEEPER MOISTURE. UPSLOPE/OROGRAPHIC MOTION MAY BE THE DRIVING COMPONENT AIDING SNOWFALL...AND WHERE THAT IS MAXIMIZED...EXPECT GENERALLY 1-2 INCHES OF SNOW TONIGHT OVER HIGHER TERRAIN NEAR LAKE SUPERIOR. INCREASED SUBSIDENCE AND LOWERING OF INVERSION HGTS AHEAD OF THE BUILDING MID-LVL RDG UPSTREAM MAY ALSO CONTRIBUTE TO A BRIEF PD OF UPSLOPE FZDZ LATE TONIGHT OVER THE NRN TIER COUNTIES IN NRLY FLOW LATE TONIGHT...BUT NAM SNDGS SHOW THE SHALLOW MOIST LAYER COOLING TO -10C BY SUNRISE WHICH SHOULD AGAIN SUPPORT MAINLY LIGHT SNOW/FLURRIES. SINCE FZDZ THREAT IS UNCERTAIN AND LOOKS TO BE BRIEF IF IT DOES OCCUR WL LEAVE IT OUT OF GRIDS FOR NOW. LOOK FOR MIN TEMPS RANGING FROM THE LOWER 20S INTERIOR WEST TO UPPER 20S EAST HALF. 1034 MB SFC RIDGE BUILDING IN FROM THE WEST SHOULD WEAKEN THE PRES GRADIENT AND THUS ALLOW NRLY WINDS TO DIMINISH ACROSS THE AREA BY AFTERNOON. CONTINUED LOWERING OF INVERSION BASES BLO 3KFT WILL QUICKLY DIMINISH ANY REMAINING LIGHT UPSLOPE SHSN TO FLURRIES BY LATE MORNING. LOOK FOR HIGHS RANGING FROM THE LOWER TO MID 20S WEST TO LOWER 30S EAST HALF. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 346 AM EST TUE DEC 9 2014 AN UPPER RIDGE WILL BUILD OVER THE CWA THROUGH SAT AS A SFC RIDGE SITS OVER THE CWA BEFORE MOVING SE FRI INTO SAT. THIS WILL KEEP CONDITIONS ON THE QUIET SIDE WITH NO PRECIP EXPECTED THROUGH 00Z SUN. WED NIGHT LOOKS TO BE THE COLDEST NIGHT WITH SINGLE DIGIT ABOVE ZERO LOWS INLAND AS THE RIDGE WILL BE OVERHEAD AND THE SIGNIFICANTLY WARMER AIRMASS IS STILL TO THE W. 850MB TEMPS WILL BE ON THE RISE FROM AOB 0C AT 12Z WED TO AOA 10C BY 00Z SAT...WITH THE WARMER TEMPS STICKING AROUND THROUGH SAT. WARMEST TEMPS EXPECTED ON SAT WITH HIGHS FROM THE UPPER 30S TO LOW 40S. WHILE THERE IS A LOT OF UNCERTAINTY WITH THE TRANSITION INTO A MORE ACTIVE PATTER LATE IN THE WEEKEND...IT DOES LOOK LIKE SOME LIGHT PRECIP IS POSSIBLE SOMETIME SUN INTO MON...AND PTYPE WILL TRANSITION BACK TO SNOW AT LEAST OVER PORTIONS OF THE AREA BY MON. LOTS WILL DEPEND ON THE TRACK/STRENGTH OF UPPER LEVEL ENERGY WHICH MODELS VARY SUBSTANTIALLY FROM RUN TO RUN. STILL NOT BUYING GREATER QPF/LOW LEVEL MOISTURE THAT MODELS SHOW ON SUN/SUN NIGHT AS MODELS LIKELY ARE OVERDOING LOW LEVEL MOISTURE AS THEY OFTEN DO WHEN MODELING SNOWPACK MELTING. REMOVED ANY MENTION OF FREEZING RAIN FOR SAT NIGHT-MON SINCE SFC TEMPS WILL BE TOO WARM FOR FREEZING RAIN IF THE RAIN/CLOUDS ARE AS THICK AS MODELS SUGGEST...AND IF THERE IS LESS LOW LEVEL MOISTURE TEMPS WILL BE COLDER BUT PRECIPITATION PROBABLY WILL NOT OCCUR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1242 AM EST TUE DEC 9 2014 LOW-LEVEL MOISTURE IN THE WAKE OF LOW PRESSURE MOVING OVER EASTERN UPR MICHIGAN IS COMBINING WITH UPSLOPE FLOW TO MAINTAIN LIFR/IFR CIGS AT ALL THE TAF SITES. EXPECT MVFR OR IFR VSBY OVERNIGHT WITH SOME LGT SNOW SHOWERS OR EVEN DZ/FZDZ. IMPROVEMENT EXPECTED AT KCMX LATE IN THE NIGHT AS UPSLOPING DIMINISHES. ADDITIONAL IMPROVEMENT WILL OCCUR AT ALL THE TAF SITES TODAY BUT BKN-OVC MVFR CIGS SHOULD REMAIN IN PLACE INTO THE EVENING AS MOISTURE REMAINS TRAPPED BENEATH INVERSION. HOWEVER...SKIES SHOULD AT LEAST PARTIALLY CLEAR OUT AT KIWD BY AFTN AS DOWNSLOPING EAST FLOW DEVELOPS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 304 PM EST MON DEC 8 2014 BEHIND THE LOW...N TO NW WINDS RAMP UP TONIGHT...AIDED BY PRES RISES APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS POTENTIAL FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL TO SCNTRL LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH PRES RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE UPPER LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED... AND THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...VOSS LONG TERM...TITUS AVIATION...JLA MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1244 AM EST TUE DEC 9 2014 .UPDATE... ISSUED AT 713 PM EST MON DEC 8 2014 LOW PRESSURE SLIDING OVER CNTRL UPR MICHIGAN AS OF 23Z. COLD AIR IN WAKE OF THE LOW SLOW TO ARRIVE. DEEP MOISTURE TIED INTO THE LOW HAS FADED QUICKLY AND LEFTOVER MOISTURE IS SHALLOW IN DEPTH AND TEMPS WITHIN THE MOIST LAYER ARE ONLY AS COOL AS -4C TO -6C OVER WESTERN LK SUPERIOR AND WESTERN CWA. VSBY AT IWD AND CMX HAS BEEN BLO 5SM SINCE SUNSET. REPORTS FM SOCIAL MEDIA INDICATE DRIZZLE OCCURRING OVER KEWEENAW AND LOWER ELEVATIONS OF ONTONAGON COUNTY. SOME SNOW FLURRIES ARE FALLING OVER HIGHER TERRAIN IN ONTONAGON COUNTY. ADDED PATCHY DZ/FZDZ TO GRIDS UNTIL AROUND 06Z FOR WEST/NORTHWEST AND INTO NCNTRL. RAP/NAM/GFS SOUNDINGS INDICATE AFTER 06Z IT BECOMES COLD ENOUGH FOR MIXED PRECIP TO CHANGE TO MAINLY SNOW. ADDED FOG TO MUCH OF EAST HALF OF CWA THROUGH THE EVENING WITH SOUTHERLY FLOW OVER LK MICHIGAN PUSHING DWPNTS IN LOW 30S OVER THE WET SNOW PACK FM THE SNOW THAT OCCURRED EARLIER TODAY. ALREADY SEEING VSBY BLO 2SM OVER MOST OF THE EAST PART OF THE CWA...INCLUDING VSBY DOWN TO 1/4SM IN THE LAST HOUR AT MNM. ONCE WINDS IN BLYR SHIFT TO NW LATER THIS EVENING...FOG SHOULD BEGIN TO LIFT AS MOISTENING FLOW OFF LK MICHIGAN WILL BE DIMINISHED. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 304 PM EST MON DEC 8 2014 LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS THE SHOW SHORTWAVE TROF MOVING ACROSS THE UPPER GREAT LAKES THIS AFTERNOON. MODELS INDICATE BEST ISENTROPIC ASCENT...MOISTURE TRANSPORT AND DEEP LAYER Q-VECT CONVERGENCE HAS SHIFTED EAST WITH MAIN SNOW BAND AHEAD OF THE SFC-8H TROF OVER CENTRAL UPPER MI. IT/S POSSIBLE THERE MAY BE SOME PATCHY -FZDZ LATE THIS AFTERNOON BEHIND THE SNOW BAND WITH MID-LVL DRYING AND LOW-LVL MOISTURE TOO SHALLOW TO REACH THE -10C ISOTHERM...BUT NOT SURE IF THE FZDZ WILL BE SIGNIFICANT ENOUGH TO INCLUDE IN FCST GRIDS THIS EVENING. MODELS INDICATE THAT N TO NW WINDS WILL STRENGTHEN TONIGHT BEHIND DEPARTING LOW PRES TONIGHT. COOLING LOW-LEVEL AIR MASS MAY SUPPORT SOME LAKE ENHANCED SNOW FOR A BRIEF TIME THIS EVENING. HOWEVER...SNOWFALL IS EXPECTED TO BE LIGHT FOR THE FOLLOWING REASONS...850MB TEMPS (AROUND -6C) ARE MARGINAL FOR ENHANCEMENT WHILE DEEPER MOISTURE IS AROUND...LOW-LEVEL FLOW IS NOT STRONGLY CYCLONIC...AND DGZ IS ABOVE THE UPWARD MOTION AND THE DEEPER MOISTURE. UPSLOPE/OROGRAPHIC MOTION MAY BE THE DRIVING COMPONENT AIDING SNOWFALL...AND WHERE THAT IS MAXIMIZED...EXPECT GENERALLY 1-2 INCHES OF SNOW TONIGHT OVER HIGHER TERRAIN NEAR LAKE SUPERIOR. INCREASED SUBSIDENCE AND LOWERING OF INVERSION HGTS AHEAD OF THE BUILDING MID-LVL RDG UPSTREAM MAY ALSO CONTRIBUTE TO A BRIEF PD OF UPSLOPE FZDZ LATE TONIGHT OVER THE NRN TIER COUNTIES IN NRLY FLOW LATE TONIGHT...BUT NAM SNDGS SHOW THE SHALLOW MOIST LAYER COOLING TO -10C BY SUNRISE WHICH SHOULD AGAIN SUPPORT MAINLY LIGHT SNOW/FLURRIES. SINCE FZDZ THREAT IS UNCERTAIN AND LOOKS TO BE BRIEF IF IT DOES OCCUR WL LEAVE IT OUT OF GRIDS FOR NOW. LOOK FOR MIN TEMPS RANGING FROM THE LOWER 20S INTERIOR WEST TO UPPER 20S EAST HALF. 1034 MB SFC RIDGE BUILDING IN FROM THE WEST SHOULD WEAKEN THE PRES GRADIENT AND THUS ALLOW NRLY WINDS TO DIMINISH ACROSS THE AREA BY AFTERNOON. CONTINUED LOWERING OF INVERSION BASES BLO 3KFT WILL QUICKLY DIMINISH ANY REMAINING LIGHT UPSLOPE SHSN TO FLURRIES BY LATE MORNING. LOOK FOR HIGHS RANGING FROM THE LOWER TO MID 20S WEST TO LOWER 30S EAST HALF. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 422 PM EST MON DEC 8 2014 DRY WEATHER WILL BE THE RULE THROUGH SATURDAY MORNING...WITH HIGH PRESSURE FROM THE SFC-500MB. BOTH THE GFS AND ECMWF BRING SOME MOISTURE BACK TO THE AREA DURING THE DAY SATURDAY...AS THE SFC RIDGE EXITS E TO THE LOWER GREAT LAKES AND THE AXIS OF THE 500MB RIDGE MOVES ACROSS THE UPPER GREAT LAKES. LOOK FOR SLOWLY INCREASING W-SW WINDS DURING THE DAY SATURDAY WITH 850MB TEMPS WARMING TO 9 TO 12C. THIS WILL BE QUITE A CHANGE FROM THE CURRENT VALUES WHICH ARE HOVERING AROUND -4C. THE MAIN CONCERN FOR THIS PERIOD WILL COME IN SATURDAY THROUGH MONDAY. AS MOISTURE INCREASES...LIGHT WAA WILL LIKELY OVERSPREAD THE CWA. KEPT THE MENTION OF PATCHY FOG AS WELL FOR THIS WILL BE IN ADVANCE OF THE ELONGATED SFC LOW OVER THE N AND CENTRAL PLAINS AT 00Z SUNDAY WITH THE HIGH DEW POINTS OVER THE MELTING SNOWPACK. THE 12Z RUNS OF THE ECMWF AND GFS BOTH HAVE THE LOW OVER MN AT 12Z SUNDAY...THEN SHIFTING ACROSS UPPER MI/LAKE SUPERIOR/CENTRAL ONTARIO SUNDAY NIGHT. WITH LOW TEMPERATURES FALLING INTO THE MID 20S TO LOW 30S...THE POTENTIAL EXISTS FOR FREEZING RAIN OR FREEZING DRIZZLE. WILL CONTINUE TO FOCUS ON THIS PERIOD...AND ADJUST AS NEEDED AS THE TIME NEARS. LOOK FOR THE COLD AIR TO SURGE IN BEHIND THE EXITING LOW/COLD FRONT SUNDAY NIGHT INTO MONDAY...WITH PRECIP TURNING ALL BACK TO SNOW BY MONDAY EVENING AT THE LATEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1242 AM EST TUE DEC 9 2014 LOW-LEVEL MOISTURE IN THE WAKE OF LOW PRESSURE MOVING OVER EASTERN UPR MICHIGAN IS COMBINING WITH UPSLOPE FLOW TO MAINTAIN LIFR/IFR CIGS AT ALL THE TAF SITES. EXPECT MVFR OR IFR VSBY OVERNIGHT WITH SOME LGT SNOW SHOWERS OR EVEN DZ/FZDZ. IMPROVEMENT EXPECTED AT KCMX LATE IN THE NIGHT AS UPSLOPING DIMINISHES. ADDITIONAL IMPROVEMENT WILL OCCUR AT ALL THE TAF SITES TODAY BUT BKN-OVC MVFR CIGS SHOULD REMAIN IN PLACE INTO THE EVENING AS MOISTURE REMAINS TRAPPED BENEATH INVERSION. HOWEVER...SKIES SHOULD AT LEAST PARTIALLY CLEAR OUT AT KIWD BY AFTN AS DOWNSLOPING EAST FLOW DEVELOPS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 304 PM EST MON DEC 8 2014 BEHIND THE LOW...N TO NW WINDS RAMP UP TONIGHT...AIDED BY PRES RISES APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS POTENTIAL FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL TO SCNTRL LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH PRES RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE UPPER LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED... AND THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...VOSS LONG TERM...KF AVIATION...JLA MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1205 AM EST TUE DEC 9 2014 .AVIATION... //DISCUSSION... ABOUT A HALF INCH OF SNOW HAS BEEN REPORTED FROM THE MIDLAND AREA DURING THE EVENING WHERE A MIX WITH RAIN ONLY OCCURRED BRIEFLY AT THE ONSET. EXPECT ALL SNOW TO CONTINUE THERE WHILE A RAIN SNOW MIX WILL BE MORE COMMON IN THE FNT AND PTK AREA...AND ALL RAIN AT DTW UNTIL THE COLD FRONT MOVES THROUGH THE REGION. THE GREATEST RESTRICTION WILL BE LIFR CEILING WITH MOSTLY IFR VISIBILITY IN FOG AND DRIZZLE PRIOR TO THE GRADUAL WIND SHIFT TOWARD THE NORTHWEST. COOLER AND DRIER AIR WILL THEN LEAD TO GRADUAL IMPROVEMENT TO MVFR WHERE CONDITIONS WILL SETTLE THROUGH THE AFTERNOON INTO TUESDAY EVENING. FOR DTW... RAIN DURING THE EARLY MORNING COULD CONTAIN A FEW WET SNOW FLAKES...BUT NOT ENOUGH FOR INCLUSION IN THE FORECAST AND WITH NO ACCUMULATION. //DTW THRESHOLD THREATS... * HIGH CONFIDENCE IN CEILING BELOW 5000 FEET DURING THE NIGHT THROUGH AFTERNOON. * HIGH CONFIDENCE IN RAIN AS PRECIPITATION TYPE. * LOW CONFIDENCE IN VISIBILITY DROPPING BELOW 1/2 SM AND/OR CIGS BELOW 200 FT. && .PREV DISCUSSION...ISSUED 835 PM EST MON DEC 8 2014 UPDATE... THE EARLIER UPDATE NUDGED THE FORECAST TOWARD A SLIGHTLY COLDER PRECIPITATION TYPE SOLUTION BY ADDING A GREATER COMPONENT OF SNOW OR A RAIN/SNOW MIX. THIS IS BASED ON RADAR INDICATIONS OF HIGHER PRECIPITATION RATES CAPABLE OF GREATER WET BULB COOLING...BUT THE OVERALL THERMAL PROFILE STILL SUPPORTS MOSTLY SNOW IN THE TRI CITIES REGION WITH JUST A BRIEF RAIN/SNOW MIX IN THE DETROIT AREA TO THE OHIO BORDER. PRECIPITATION RATES ARE BEING ENHANCED BY A FAVORABLE COMBINATION OF DYNAMIC FORCING FROM THE UPPER WAVE ACTING ON THE LOW TO MID LEVEL THETA-E RIDGE WHICH IS MATURING INTO A WELL DEFINED TROWAL. STRONG VERTICAL MOTION RESPONSE...AND THE POTENTIAL FOR IT TO CONTINUE...IS INDICATED BY STEEP MID LEVEL LAPSE RATES CENTERED AROUND 700 MB IN THE NEW 00Z DTX SOUNDING AS THE MOISTURE AXIS SLIDES THROUGH SE MICHIGAN DURING THE REST OF THE EVENING. THE MID LEVEL DRY SLOT ASSOCIATED WITH THE UPPER WAVE WILL BRING A QUICK END TO THE SNOW BY MIDNIGHT. THE PROGRESSION OF THE PATTERN WILL BE FAST ENOUGH TO HOLD THE LINE ON MINIMAL SNOW ACCUMULATION OVER THE AREA. THE TRI CITIES AND NORTHERN THUMB REGION DOES HAVE POTENTIAL FOR SNOW TO LINGER...AND MINOR UPWARD ADJUSTMENTS ON ACCUMULATION...AS MOISTURE REMAINS DEEPER WITHIN THE DEFORMATION AXIS ON THE NW FLANK OF THE WAVE AS IT TRACKS THROUGH THE SOUTHERN GREAT LAKES. THE TRANSITION FROM SNOW TO DRIZZLE...OR LACK THEREOF...WILL BE MONITORED DURING THE LATE EVENING. DRIZZLE AND FOG WILL MOVE OVER THE REST OF SE MICHIGAN AND PERSIST UNTIL NORTHWEST WIND INCREASES BEHIND THE COLD FRONT TOWARD SUNRISE. PREV DISCUSSION...ISSUED 353 PM EST MON DEC 8 2014 SHORT TERM...THROUGH TONIGHT 19Z WATER VAPOR IMAGERY SHOWS WELL-DEFINED COMPACT MIDLEVEL WAVE OVER THE MN/IA BORDER SPINNING SEWD. UPPER LEVEL MOISTURE WAS PRESENT DOWNSTREAM OF THIS FEATURE OVER IN AND MI. MIDLEVEL FRONTOGENESIS WAS SUPPORTING A NORTH/SOUTH ORIENTED SWATH OF LIGHT TO MODERATE PRECIP OVER WESTERN MI AND NORTHERN IN...MOVING NEWD. THERE WAS A SHARP LOW-LEVEL MOISTURE GRADIENT IN PLACE AS EVIDENCED BY QUICKLY LOWERING CEILINGS AT THE ONSET OF PRECIPITATION. NWP IS IN GOOD AGREEMENT OF THE AREA OF FGEN AND ASSOCIATED PRECIP SHIELD TRANSLATING THROUGH THE LOCAL AREA BETWEEN AROUND 23-05Z /PERHAPS WEAKENING SOMEWHAT/ WITH ANY ONE AREA SEEING AROUND 3-4 HOURS OF PRECIP. QPF SHOULD BE GENERALLY LIGHT...AROUND .10-.15 INCHES. PRECIP TYPE IS A BIT OF A CHALLENGE. TEMPERATURES THIS AFTERNOON ARE IN THE UPPER 30S AND LOW 40S WITH DEWPOINTS STILL IN THE LOW/MID 20S OVER SE MI. RAP HAS A PRETTY GOOD HANDLE ON THIS WITH ASSOCIATED WETBULB TEMPS 32-35F. NOT EXPECTING TEMPS TO DROP A WHOLE LOT IN ADVANCE OF THE PRECIP WITH CLOUD COVER AND SOUTHERLY FLOW. DEWPOINTS SHOULD EDGE UPWARD INTO THE UPPER 20S. WETBULB EFFECTS ONCE THE PRECIP STARTS SHOULD DROP TEMPS INTO THE 33-37 DEGREE RANGE. WHILE MUCH OF THE REGION COULD EXPERIENCE A MIX OF RAIN AND SNOW /WITH SNOW MORE LIKELY IN THE AREAS OF EMBEDDED HEAVIER PRECIP/...HAVE GONE WITH PREDOMINANTLY RAIN FOR METRO DETROIT AND SOUTH...MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB...AND A MIX INBETWEEN. EXPECTING LOWS IN THE AREAS THAT EXPERIENCE SNOW TO MAINLY REMAIN AOA FREEZING WITH LOW SNOW RATIOS SO ACCUMULATIONS ARE NOT MUCH OF A CONCERN...WITH PERHAPS UP TO HALF AN INCH IN SPOTS ALONG AND NORTH OF I-69. ONCE THE UPPER MOISTURE STRIPS AWAY AFTER MIDNIGHT...THE SURFACE LOW WILL TRANSLATE OVER THE REGION CAUSING WINDS TO BECOME LIGHT. LOW- LEVEL MOISTURE WILL STILL BE AROUND. UPSTREAM OBS INDICATE WIDESPREAD LOW CLOUDS WITH AREAS OF FOG AND DRIZZLE AND EXPECT THAT WILL BE THE CASE OVER OUR AREA AS WELL. PATCHY AREAS OF FREEZING DRIZZLE ARE POSSIBLE WHERE TEMPS GET CLOSER TO FREEZING...ESPECIALLY OVER THE NORTHERN PARTS OF THE FORECAST AREA. LONG TERM...TUESDAY THROUGH SUNDAY THE EXTENDED FORECAST WILL START OFF WITH AN UPPER LEVEL TROUGH OVER THE GREAT LAKES DRIFTING OFF TO THE MID ATLANTIC COAST AS IT BECOMES A CLOSED MID LEVEL CIRCULATION. SE MI WILL BE UNDER THE UPPER LEVEL COLD POOL AND BROAD LIFT FROM THE TROUGH DURING THE MID WEEK PERIOD BEFORE LONGWAVE RIDGE BUILDING UP THROUGH THE CENTRAL CONUS TRIES TO FORCE ITS WAY INTO THE REGION. A BLOCKING PATTERN LOOKS TO SET UP BY THE END OF THE WEEK WITH THE INTERFACE BETWEEN THE RIDGE AND TROUGH IN THE VICINITY OF EASTERN MI. THIS PRESENTS ONE OF THE MAIN CHALLENGES IN THE LONG TERM AS THAT IS THE DIFFERENCE BETWEEN A MILD SUNNY WEEKEND OR A CLOUDY WEEKEND WITH THE POSSIBILITY OF LIGHT SNOWFALL. WE START OFF TUESDAY WITH THE TROUGH AXIS OVER HEAD WHICH WILL PRODUCE OVERCAST SKIES AND WINDS VEERING FROM SOUTHERLY TO NORTHERLY THROUGH THE AFTERNOON. ADDITIONALLY...THE BROAD CYCLONIC FLOW AND LIFT WITH A SATURATED COLUMN UP TO 8KFT WILL PRODUCE SOME LINGERING SHOWERS THROUGH THE DAY AS THE FORCING PULLS OFF TO THE EAST. ONE QUESTION REMAINS TO BE WHAT WILL THE PTYPE BE ON TUESDAY? THE TREND WILL BE FOR THE COLUMN TO COOL AS THE -26C 500MB COLD POOL SLIDE OVER THE AREA. 925MB TEMPS WILL BE CLOSE TO ZERO WITH 850MB TEMPS A COUPLE DEGREES IN THE NEGATIVE. BUT THE SATURATION ONLY CLIMBS TO AROUND 750MB OR SO WHICH MAY NOT QUITE BE ENOUGH FOR ALL ICE CRYSTALS WITH TEMPS NEARING -9C. SO KEPT THE MENTION OF DRIZZLE THROUGH THE FIRST HALF OF THE DAY POSSIBLY SWITCHING OVER TO ALL SNOW CLOSER TO 00Z WEDNESDAY. TEMPERATURES ABOVE FREEZING UP TOWARD 950MB...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE CWA SHOULD PREVENT FREEZING DRIZZLE AS SFC TEMPS REACH INTO THE UPPER 30S. THE NATURE OF THE PRECIP FORCING CHANGES OVERNIGHT TUESDAY INTO WEDNESDAY AS THE DEEPER MOISTURE GETS PULLED EAST LEAVING A VERY SHALLOW LAYER OF MOISTURE WITH NORTHERLY FLOW. THIS COLDER NORTHERLY FLOW OFF LAKE HURON WILL LIKELY PRODUCE SOME LAKE EFFECT SNOW OVER THE THUMB BUT MODELS DO NO INDICATE ANY STRONG CONVERGENT REGIONS OVER THE LAKE AND DELTA T FROM THE SFC TO 850MB IS RATHER WEAK AROUND 10C. WILL CONTINUE THE HIGHER POP...LOWER QPF FORECAST FOR THE THUMB UNTIL WE SEE MORE DEFINITIVE SIGNATURES TO LOWER THE POPS OR START THINKING IN TERMS OF POSSIBLE ACCUMULATIONS. TEMPERATURES OVER LAND WEDNESDAY WILL HOLD AROUND THE FREEZING MARK AS THE BACKSIDE OF THE COLD POOL ALOFT LINGERS OVER THE EASTERN GREAT LAKES. HIGH PRESSURE...AND DRY WEATHER...LOOKS TO REMAIN IN PLACE THROUGH MUCH OF THE EXTENDED PERIOD. SOME RECENT MODEL RUNS INDICATE A CHANCE OF SOME SNOW SHOWERS TRYING TO CREEP IN ON THURSDAY AS A LOW PRESSURE SYSTEM DEVELOPS TO OUR EAST. CONFIDENCE IN THIS FEATURE AT THIS TIME IS LOW AND HAVE ONLY INCLUDED A SLIGHT CHANCE OF SOME SNOW FOR THE EXTREME EASTERN PORTION OF THE CWA /ST CLAIR SANILAC AND EASTERN HURON COUNTIES/. OTHERWISE DRY CONDITIONS PREVAIL THROUGH THE WEEKEND WITH THE NEXT DISTURBANCE ARRIVING LATE SUNDAY. CURRENT MODEL GUIDANCE SHOWS TEMPERATURES WILL BE WARM ENOUGH FOR PRECIPITATION WITH THIS SYSTEM TO BE ALL RAIN...HOWEVER...WOULD NOT BE SURPRISED IF SOME SNOW MIXES IN ON SUNDAY NIGHT AS TEMPERATURES BEGIN TO DROP. FOR NOW HAVE JUST LEFT THE PRECIPITATION AS ALL RAIN BUT SNOW MAY HAVE TO BE ADDED LATER AS WE GET A BETTER SAMPLING OF HOW THIS SYSTEM WILL PLAY OUT. MARINE... AN UPPER LEVEL TROUGH OF LOW PRESSURE AND ASSOCIATED WEAK SURFACE REFLECTION WILL BRING UNSETTLED WEATHER TO THE GREAT LAKES FOR THE NEXT COUPLE DAYS. SOUTHERLY FLOW AHEAD OF THE TROUGH IS BEGINNING TO SETTLE ALLOWING US TO CANCEL THE SMALL CRAFT ADVISORY OVER SAGINAW BAY A FEW HOURS EARLY BUT FLOW OVER LAKE HURON WILL WARRANT THE CONTINUATION OF THE NEARSHORE SMALL CRAFTS THROUGH THE EVENING WITH GUSTS AROUND 25 KNOTS AND ELEVATED WAVE HEIGHTS. THE TROUGH AXIS WILL TRACK ACROSS THE AREA TUESDAY VEERING WINDS AROUND TO THE NORTH. COLD AIR ADVECTION BEHIND A PASSING COLD FRONT OVER THE SLIGHTLY WARMER WATERS...WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE STALLING UPPER LEVEL TROUGH AND THE RIDGE TRYING TO BUILD IN FROM THE WEST WILL HELP EXCITE THE WIND FIELD ONCE AGAIN. A MARGINAL GALE WATCH CONTINUES FOR THE SOUTHERN LAKE HURON BASIN AS WINDS LOOK TO GUST NEAR 35 KNOTS WITH THIS SETUP. THE UPPER LEVEL FEATURE MAY TRY TO HEAD BACK WEST TOWARD THE AREA LATER IN THE WEEK WHICH WOULD KEEP SOME SEMBLANCE OF THE INCREASED NORTHERLY FLOW THROUGH MID WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...GALE WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR LHZ441>443-462>464. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....BT UPDATE.......BT SHORT TERM...DT LONG TERM....DRK/RK MARINE.......DRK YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS JACKSON MS
402 AM CST TUE DEC 9 2014 .SHORT TERM...FOCUS OF THIS SHORT TERM CONTINUES TO BE WITH THE REINFORCING SHOT OF COOLER AIR FOR LATER TODAY. FROM THIS...THE MAIN FORECAST ELEMENTS WILL BE ON TEMPS AND CLOUDS. THE NOTICEABLE ARRIVAL OF THE COOLER AIR WILL NOT BE UNTIL LATER IN THE AFTERNOON AND EVENING FOR THE CWA. PRIOR TO THAT...SFC WINDS WILL BE OUT OF THE NW...BUT FULL SUNSHINE AND SOMEWHAT OF A FLAT LOW LEVEL THERMAL AXIS WILL ALLOW FOR A BETTER WARMUP THAN PREV EXPECTED. DUE TO THIS...AREAS SOUTH OF THE HWY 82 CORRIDOR SHOULD PEAK BETWEEN 60-66 DEGREES AND I HAVE USED VALUES THAT WERE ON THE UPPER END OF THE GUID ENVELOP. FOR LOCATIONS ALONG AND NORTH OF HWY 82...THIS IS MORE TRICKY AS THE PROGRESSION OF THE COOLER AIR LOOKS TO ARRIVE HERE IN TIME TO LIMIT WARMING A BIT. A BLEND OF THE HI-RES AND RAP MODELS WERE USED HERE AND HIGHS MAY ONLY REACH 53-58. AS FOR CLOUDS...PREV EXPECTATIONS WERE FOR CLEAR SKIES. HOWEVER...THE LATEST NAM/RAP INDICATE THAT FRONTAL LIFT ALONG WITH STRONG CAA WILL SUPPORT AT LEAST A BKN DECK NEAR AND BEHIND THE FRONT. FOR TONIGHT...THESE LOW CLOUDS SHOULD DISSIPATE DURING THE OVER...BUT THEN BEGIN TO GET REPLACED BY INCREASING/THICKENING HIGH CLOUDS...ESPECIALLY FOR MIDDAY WED AND INTO THE AFTERNOON/EVE. LOWS TONIGHT ARE NOT CLEAR CUT AS THE GFS MOS IS COOLER AND OTHER GUID IS A BIT WARMER. I LIKE A BLEND WITH A LEAN TOWARD THE WARMER GUID DUE TO SFC WINDS STAYING UP OVERNIGHT. SOME FREEZING TEMPS ARE POSSIBLE ACROSS THE N HALF...BUT IF THAT OCCURS IT WILL BE BRIEF. HIGHS WED WILL BE ON THE COOL SIDE AND RANGE FROM THE UPPER 40S N TO MID 50S S. A COMBO OF CAA AND HIGH CLOUDS WILL KEEP TEMPS IN CHECK. IF THE HIGH CLOUDS BECOME THICK ENOUGH...READINGS COULD FALL SHORT OF EXPECTED VALUES. WED NIGHT WILL BE THE COLDEST NIGHT THIS WEEK...BUT I WILL NOT GET TOO AGGRESSIVE AND MUCH OF THE COOLING WILL DEPEND ON IF THE HIGH CLOUDS EXIT OR THIN ENOUGH. ALL THE AVAILABLE GUID IS CLOSE WITH UPPER 20S N TO LOWER 30S S AS THE RANGE. THU WILL BE A TAD WARMER AS SOME MODIFICATION OCCURS THANKS TO A BIT MORE SUN WITH A MIX OF CLOUDS AS WELL. /CME/ .LONG TERM...THURSDAY NIGHT THROUGH NEXT MONDAY... GLOBAL MODELS ARE REMARKABLY CONSISTENT CONSIDERING THE AMPLIFIED PATTERN THAT IS FORECAST TO EVOLVE. A DEEP TROUGH ALONG THE EAST COAST AT THE START OF THE PERIOD WILL SHIFT EAST AND ALLOW A RIDGE TO MOVE ACROSS THE MS VALLEY THROUGH THE WEEKEND. FRIDAY WILL BE SEASONABLY COOL...BUT THEN EXPECT TEMPERATURES TO WARM SOME SATURDAY AND SUNDAY TO SLIGHTLY ABOVE CLIMATIC NORMALS AS SURFACE PRESSURES FALL AND RETURN FLOW BEGINS TO DEVELOP. EMPHASIS WILL THEN SHIFT TO THE SOUTHERN STREAM AND A SIGNIFICANT SHORTWAVE TROUGH EXPECTED TO MOVE INTO THE LOWER MS VALLEY REGION EARLY NEXT WEEK. MODEL DIFFERENCES START TO DEVELOP WITH HANDLING OF THIS TROUGH AND HOW MUCH PHASING TAKES PLACE - THE ECWMF IS MORE DISTINCT/SEPARATE AND THEREFORE A LITTLE SLOWER AND MORE ROBUST WITH CONVECTIVE PRECIPITATION IN THE ARKLAMISS WHILE THE GFS/GEFS INDICATE MORE ENERGY IN THE NORTHERN STREAM. THE AMPLIFIED PATTERN MAY SUPPORT MORE OF A CLOSED OFF SOLUTION SUCH PER THE ECWMF...BUT INSTABILITY WILL BE VERY LIMITED AS THE PRECEDING HIGH DOES NOT ALLOW FOR MUCH OF A WINDOW FOR SIGNIFICANT WARM ADVECTION/MOISTURE TRANSPORT. /EC/ && .AVIATION...TRICKY VIS FORECAST THIS MORNING AS PATCHY SHALLOW GROUND FOG IS CAUSING SITES TO BOUNCE WITH IFR/MVFR/VFR VIS CONDITIONS. THIS SHOULD IMPROVE BETWEEN 13-15Z WITH VFR CONDITIONS EXPECTED ACROSS MUCH OF THE AREA FOR MUCH OF THE DAY. THE EXCEPTION WILL BE ACROSS THE N HALF WHERE A MVFR CIG LOOKS TO OCCUR WITH THE PASSAGE OF THE FRONT AFTER 20Z AND LINGER TO ABOUT 01-03Z. /CME/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 63 33 51 33 / 0 0 0 0 MERIDIAN 63 32 51 30 / 0 0 0 0 VICKSBURG 64 33 51 32 / 0 0 0 0 HATTIESBURG 66 35 55 33 / 0 0 0 0 NATCHEZ 64 35 52 34 / 0 0 0 0 GREENVILLE 56 32 48 31 / 0 0 0 0 GREENWOOD 56 31 49 30 / 0 0 0 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ CME/EC/
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
317 AM CST Tue Dec 9 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 315 AM CST Tue Dec 9 2014 Vort max which dropped across the region overnight is now working its way into the TN valley, with associated cold front currently dropping into far s counties of our CWA. Early morning 11-3.9 low cloud imagery indicates an extensive area of ST and SC in the wake of the front, with this low cloud deck extending into the upper Mississippi Valley and upper Great Lakes with only a few minor breaks noted. While can`t rule out a bit of sunshine, believe clouds will dominate much of the region today due to the extensive low level moisture trapped beneath a fairly stout inversion, as suggested by 925mb RH progs from both the RUC and NAM. Today will certainly be cooler than yesterday, and I`ve attempted to try to limit diurnal swing as clouds should definitely inhibit a big daytime temp swing. However, if a solid cloud deck holds throughout the day going max temps may still be a bit too warm. Truett .LONG TERM: (Tonight through Monday) Issued at 315 AM CST Tue Dec 9 2014 (Tonight-Thursday) Chilly and tranquil weather should continue during this time frame, and the primary forecast concern is how short-term low cloud trends will evolve heading into midweek. Given forecast inversion and north-northeast low level flow forecast across the area as surface ridge works into the upper Mississippi Valley, believe low clouds will hold over the region tonight and will likely have a tendency to hang tough through Wednesday, with some additional mid level cloudiness spilling into the area as strong but moisture-starved shortwave zips down the back side of the large upper level low winding up over the east coast. Temperatures should moderate a bit by Thursday with a slightly warmer airmass and a bit more sunshine. (Friday-Monday) Medium range solutions take eastern U.S. low up the eastern seaboard heading into the end of the week, allowing upper level ridge to work into the central CONUS. Resultant warming of the AMS over the mid-Mississippi Valley should provide a strong rebound in temps across the FA, with highs in the 50s by the end of the week. UA pattern over the CONUS becomes even more progressive by late in the period, allowing aforementioned ridge to push east and deep UA trof over the western U.S. to sweep into the Plains. This could mean some precip in our CWA by Sunday, with better chances by the start of the new work week. This system should be a rain-maker for our area due to the relatively mild AMS. Truett && .AVIATION: (For the 06z TAFs through 06z Tuesday Night) Issued at 1128 PM CST Mon Dec 8 2014 Secondary cold front is making its way south across forecast area as of 05z. It should move south of I-70 by 06z Tuesday. Plenty of stratus associated with frontal boundary as cigs have dropped to MVFR at KUIN and should at rest of taf sites by 09z Tuesday. Though KCOU will be on western edge of cloud deck. Otherwise, MVFR cigs to persist through rest of taf forecast period with gusty north winds diminishing a bit just after sunrise. Surface ridge to build back in by Tuesday evening with winds becoming northeasterly. Specifics for KSTL: Secondary cold front is making its way south across forecast area as of 05z. It should move south of I-70 by 06z Tuesday. Plenty of stratus associated with frontal boundary with cigs dropping to MVFR by 09z Tuesday. MVFR cigs to persist through rest of taf forecast period with gusty north winds diminishing a bit by 15z Tuesday. Surface ridge to build back in by Tuesday evening with winds becoming northeasterly by 03z Wednesday. Byrd && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
358 AM CST TUE DEC 9 2014 .SYNOPSIS... ISSUED AT 358 AM CST TUE DEC 9 2014 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A DECENT UPPER LEVEL DISTURBANCE OVER NRN ILLINOIS WITH A TROUGH EXTENDING SWD TO THE FLORIDA PANHANDLE. FURTHER WEST...A BROAD RIDGE EXTENDED FROM THE INTERMOUNTAIN WEST NORTH INTO THE YUKON OF CANADA. WITHIN THIS RIDGE...A DISTURBANCE WAS NOTED OVER WESTERN MONTANA. CURRENT WV IMAGERY AS OF 2 AM CST HAS THIS FEATURE NOW OVER EASTERN PORTIONS OF MT. AT THE SURFACE...AN ELONGATED AREA OF HIGH PRESSURE EXTENDED ACROSS THE EASTERN DAKOTAS INTO EASTERN NEBRASKA. FURTHER WEST...A TROUGH OF LOW PRESSURE WAS PRESENT OVER EASTERN WYOMING INTO NORTHERN COLORADO. AN AREA OF STRATUS AND FOG HAS DEVELOPED ON THE WESTERN PERIPHERY OF THE HIGH OVERNIGHT...AND THIS AREA OF CLOUDS AND FOG EXTENDED FROM NORTH CENTRAL NEBRASKA INTO CENTRAL AND PORTIONS OF SWRN NEBRASKA. THE FOG WAS PRIMARILY ALONG THE WESTERN EDGE OF THE STRATUS/LOW CLOUDS AND ROUGHLY EXTENDED FROM VALENTINE TO AINSWORTH...SWD TO THEDFORD...NORTH PLATTE AND BROKEN BOW. FURTHER WEST...SOME HIGH CLOUDS WERE MOVING INTO THE NEBRASKA PANHANDLE AND FAR WESTERN PORTIONS OF THE FORECAST AREA ATTM. UNDER MOSTLY CLOUDY SKIES...TEMPERATURES AS OF 3 AM CST...RANGED FROM 15 AT NORTH PLATTE TO 25 AT BROKEN BOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CST TUE DEC 9 2014 TODAY AND TONIGHT...THE FORECAST CHALLENGES OVER THE NEXT 24 HOURS...ARE TEMPERATURES TODAY...AS WELL AS FOG POTENTIAL THIS MORNING...AS WELL AS TONIGHT. FOR TODAY...AS MENTIONED ABOVE...FOG HAS DEVELOPED ALONG THE HIGHWAY 83 CORRIDOR...AS WELL AS ALONG A LINE FROM AINSWORTH TO BROKEN BOW. ATTM...THE LATEST HI RES RUC SOLN HAS THIS AREA OF FOG EXPANDING SLIGHTLY TO THE SOUTHWEST TOWARD DAYBREAK. ONE WILDCARD IN THE DEGREE OF WESTWARD DEVELOPMENT OF FOG...IS THE POTENTIAL IMPACT OF HIGH LEVEL CLOUDINESS MOVING IN FROM THE WEST. ATTM...FOG VISBYS HAVE BEEN GENERALLY IN THE 1 TO 5 MILE RANGE...SO WILL KEEP FOG MENTION AS PATCHY THIS MORNING. BASED ON THE HRRR SOLN...FOG SHOULD BEGIN TO DISSIPATE DURING THE MID TO LATE MORNING TIME FRAME...AND HAVE EXTENDED THIS MENTION OF FOG INTO THE LATE MORNING HOURS GIVEN THIS MODEL TREND. HIGH PRESSURE WILL BEGIN TO TRACK EAST LATER TODAY INCREASING SRLY WINDS DURING THE AFTERNOON HOURS. FOR LOCATIONS GENERALLY WEST OF HIGHWAY 61...THE WIND DIRECTION WILL TAKE ON A WESTERLY COMPONENT...RESULTING IN SOME LIMITED DOWNSLOPE AND WARMER HIGHS IN THE LOWER 50S. FURTHER EAST...THE COMBINATION OF CLOUDS...SOUTHERLY AND SOUTHEASTERLY WINDS ON THE BACK SIDE OF THE EXITING HIGH...WILL LIMIT HIGHS IN THE UPPER 30S IN THE FAR NORTHEAST...TO THE 40S ALONG THE HIGHWAY 83 CORRIDOR. THE LATEST MAV GUIDANCE HAS TRENDED COLDER FOR HIGHS OVER THE PAST 3 RUNS...AND HAS COME INTO BETTER AGREEMENT WITH THE COLDER MET GUIDANCE. WITH THIS IN MIND...TRENDED HIGHS TDY SOME 2 TO 4 DEGREES COLDER THAN THE INHERITED FCST. FOR TONIGHT...LIGHT SRLY WINDS WILL CONTINUE...PARTICULARLY IN THE EASTERN CWA. THE LATEST NAM SOLN IS INDICATING NEAR SATURATION IN THE BOUNDARY LAYER OVERNIGHT TONIGHT...ROUGHLY EAST OF A LINE FROM CURTIS...TO ONEILL. INHERITED FCST HAD A MENTION OF PATCHY FOG OVERNIGHT IN THESE AREAS AND IT WILL BE CONTINUED WITH THE CURRENT FCST PACKAGE. OVERNIGHT LOWS WILL BE IN THE LOWER 20S...WITH SOME UPPER TEENS IN THE PLATTE RIVER VALLEY GIVEN THE EXPECTED LIGHT WINDS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 358 AM CST TUE DEC 9 2014 12Z WEDNESDAY AND BEYOND...MODELS REMAIN IN GOOD AGREEMENT THAT AMPLIFIED UPPER RIDGING OVER THE CENTRAL CONUS WILL EVENTUALLY BREAK DOWN/FORCED EAST AS A LONG WAVE TROUGH DIGS INTO THE WESTERN STATES AND EVENTUALLY THE PLAINS. TEMPERATURES UNDER THE RIDGE WILL REMAIN ABOVE AVERAGE...AND SHOULD WARM BY SEVERAL DEGREES EACH DAY. HIGHS BY FRIDAY ARE ANTICIPATED TO REACH INTO THE 50S TO LOWER 60S FOR MOST AREAS...POSSIBLY WARMER IF GREATER MIXING OCCURS. SOUTHERLY WINDS WILL HELP INCREASE LOWER LEVEL MOISTURE WHICH COULD PROVIDE FOR PATCHY FOG EACH MORNING...WEDNESDAY THROUGH SATURDAY. THE DETERMINISTIC SOLUTIONS GENERATE LIGHT DZ/QPF ACROSS PORTIONS OF OUR EAST THURSDAY...FRIDAY...AND SATURDAY...BUT THE MOISTURE PROFILES ONLY FAVOR STRATUS AND/OR FOG AS THE DEPTH OF THE RETURN IS RATHER SHALLOW. CONCERNING THIS WEEKEND AND A POTENTIAL SYSTEM...WHAT A DIFFERENCE A DAY MAKES. IN 24 HOURS THE GFS SOLUTION HAS TRENDED NORTH WITH THE TRACK OF THIS WEEKENDS CLOSED H5 LOW BY HUNDREDS OF MILES. THE MODEL GENERATED TRACK OF THE LOW YESTERDAY FAVORED THE BIG BEND OF TEXAS ON SUNDAY...THEREAFTER TRACKING THE LOW OVER HEART OF TEXAS THROUGH EARLY NEXT WEEK. TONIGHT...THE GFS IS FAVORING A SOLUTION WHICH CLOSES OFF A LOW OVER NORTHERN NEW MEXICO...THEN TRACKING THE LOW ACROSS THE PANHANDLES OF TEXAS AND OKLAHOMA...AND EVENTUALLY TOWARD THE MID-MISSOURI VALLEY. IT SHOULD BE NOTED THAT THE MODEL INDICATES THE MEAN TROUGH TAKING A NEGATIVE TILT AS IT EMERGES ON THE PLAINS. COMPLICATING MATTERS...THE EUROPEAN CAMP AND NUMEROUS GFS ENSEMBLES SUPPORT A SIMILAR TRACK INTO THE CENTRAL PLAINS /AT LEAST INITIALLY/. SO FOR THE FIRST SUITE OF RUNS PROGGING THIS SYSTEM...MODEL TO MODEL CONSISTENCY IS SHOWING SOME COHERENCE...BUT RUN TO RUN CONSISTENCY IS SEVERELY LACKING. CONFIDENCE IN ANY ONE PARTICULAR SOLUTION IS LOW...ESPECIALLY SINCE ALL LONG TERM GUIDANCE GENERATES CONVECTION ACROSS THE SOUTHERN PLAINS AND TEXAS ON SUNDAY. THE GFS SEEMS TO BE KEYING ON THE CONVECTIVE POTENTIAL...GENERATING AN AREA OF PV DESTRUCTION OVER OUR SOUTH...AND SEVERELY LIMITING THE QPF POTENTIAL ACROSS MUCH THE CWA. THE GFS HOWEVER DOES EVENTUALLY GENERATE WRAP AROUND QPF SUNDAY AFTERNOON/EVENING ACROSS OUR SOUTH AND EAST. THE WRAP AROUND IS IN QUESTION AS THE CONVECTION /PROJECTED TO BE OVER EASTERN KANSAS/ WOULD ALLOW FOR AN ASSUMED GREATER EASTWARD WOBBLE OF THE H7 LOW. SO INSTEAD OF THE MODEL PROJECTED H7 LOW OVER NORTH CENTRAL KANSAS...THE MORE LIKELY LOCATION WOULD BE EASTERN OR SOUTHEASTERN KANSAS. THE WRAP AROUND WOULD THUS BE SHUNTED SOUTHEAST AS WELL. THE ECMWF IS CONCERNING...GENERATING SIGNIFICANT SNOW ACROSS OUR SOUTHERN TIER ON SUNDAY...BUT AGAIN...THE CONVECTION THAT THE MODEL IS GENERATING PUTS ANY OF THE QPF ACROSS OUR CWA SEVERELY IN QUESTION. THE CR-INT PROCEDURE REMAINS PESSIMISTIC IN THE QPF DEPARTMENT FOR SUNDAY AND BEYOND...WHICH IS FAVORED AT THIS POINT...NO CHANGES WERE MADE TO THE BLENDED FORECAST. BUT...LAST NIGHT MY FORECAST STATED THE POTENTIAL WEEKEND STORM WAS LOOKING MORE LIKE A "DUD" FOR THE CWA...AT THIS TIME I WISH TO RETRACT THOSE WORDS AND STATE THAT THIS SYSTEM IS CERTAINLY WORTH WATCHING. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 618 PM CST MON DEC 8 2014 A BAND OF STRATUS ALONG THE BACKDOOR COLD FRONT WILL MOVE SOUTHWEST INTO NORTH CENTRAL NEBRASKA THIS EVENING WITH CIGS AROUND BKN020. THROUGH THE EARLY MORNING HOURS SOME FOG WITH MVFR VISIBILITIES IS EXPECTED TO DEVELOP OVER SOUTHWEST NEBRASKA. THIS FOG WILL BURN OFF EARLY SOME IFR CEILINGS ARE POSSIBLE BUT SIGNATURE NOT REAL STRONG SO HAVE LEFT OUT OF NORTH PLATTE TAF FOR NOW. WINDS BECOMING LIGHT AND VARIABLE OVER NIGHT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...JACOBS AVIATION...POWER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
337 AM CST TUE DEC 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CST TUE DEC 9 2014 SYNOPTIC ANALYSIS OVERNIGHT INDICATES THE UPPER LEVEL TROUGH CONTINUING TO SHIFT ACROSS THE OHIO RIVER VALLEY WHILE AN UPPER LEVEL RIDGE HAS BEGUN TO BUILD ACROSS THE ROCKY MOUNTAINS. ALOFT...A 100+ KT JET CAN BE SEEN DIVING SOUTH ACROSS IOWA AND WESTERN MISSOURI AROUND THE BASE OF THE TROUGH. IN THE MID LEVELS...HEIGHT RISES SUGGEST THE BUILDING OF THE MID LEVEL RIDGE ACROSS THE MIDWEST...AND SOME MINIMAL MID LEVEL MOISTURE PRESENT ACROSS THE PLAINS. AT THE SURFACE...LOW PRESSURE CAN BE SEEN ACROSS THE GREAT LAKES WHILE A LARGE AREA OF HIGH PRESSURE BEGINS TO SPREAD FROM MANITOBA STRETCHING SOUTH INTO NEBRASKA. LATEST SATELLITE IMAGERY SHOWS A LARGE AREA OF STRATUS CIRCULATING UNDER THE UPPER LEVEL LOW...WITH STRATUS BANDS STETCHING INTO PORTIONS OF CENTRAL NEBRASKA. UNDER THESE BANDS...METAR SITES HAVE INDICATED CEILING HEIGHTS NEAR 1500 FT AND VISIBILITIES AS LOW AS 1/4 MILE AT VALENTINE. FOR THE VERY NEAR SHORT TERM...THESE STRATUS BANDS WILL BE OF CONCERN. SHORT TERM MODELS SUCH AS THE RAP...SREF...AND HRRR ALL SUGGEST THAT REDUCED VISIBILITIES WILL BE VERY CLOSE TO OUR WESTERN BORDER...WHILE THE GFS REMAINS DRY. AT THIS TIME...CONTINUED WITH AREAS OF FOG IN THE FORECAST...BUT WILL CONTINUE TO MONITOR IN CASE A DENSE FOG ADVISORY IS NEEDED. AS SUCH...AS THE HIGH PRESSURE/RIDGE AXIS SWINGS THROUGH THE PLAINS...EXPECT WINDS TO SWITCH TO SOUTHERLY AND HELP CLEAR OUT ANY FOG THAT DOES DEVELOP BY MID TO LATE MORNING. THE MAIN FOCUS OF THE REST OF THE SHORT TERM PERIOD WILL CENTER ON THE POSSIBILITY FOR FREEZING DRIZZLE AND FOG OVERNIGHT AND INTO WEDNESDAY MORNING. AN UPPER LEVEL SHORT WAVE DISTURBANCE WILL DEVELOP ACROSS THE NORTHERN ROCKIES AND SWING THROUGH THE CENTRAL PLAINS OVERNIGHT. AT THE SURFACE...LIGHT SOUTH WINDS WILL SURGE LOW LEVEL MOISTURE NORTHWARD ACROSS MUCH OF THE AREA. THIS COMBINED WITH LIFT FROM THE UPPER LEVEL DISTURBANCE SHOULD PROMOTE FOG DEVELOPMENT. HOWEVER...SOUNDINGS INDICATE VERY DRY MID LEVELS AND BOTH THE NAM AND GFS SOLUTIONS SUGGESTING HIGHER BULK SHEAR VALUES NEAR 10 KTS...ESPECIALLY ACROSS NORTH CENTRAL KANSAS AND THE STATE LINE. THEREFORE...IT REMAINS A STRONG POSSIBILITY OF FREEZING DRIZZLE ACROSS NORTH CENTRAL KANSAS AND SOUTHERN NEBRASKA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 335 AM CST TUE DEC 9 2014 THE MODELS CONTINUE TO HAVE THE MOISTURE ACROSS THE AREA DURING THE DAY WEDNESDAY AND EVEN INTO WEDNESDAY NIGHT. EXPECT THE FOG AND FREEZING DRIZZLE FROM TUESDAY NIGHT TO CONTINUE INTO WEDNESDAY MORNING. AS TEMPERATURES WARM DURING THE MORNING THE FREEZING DRIZZLE SHOULD BECOME DRIZZLE. THE PRECIPITATION SHOULD REMAIN MAINLY IN THE SOUTHEAST PART OF THE FORECAST AREA. WILL CONTINUE WITH DRIZZLE IN THE SOUTHEAST DURING THE AFTERNOON. THE ONLY MODEL THAT MOVES THE MOISTURE OFF TO THE EAST IS THE GFS...SO WILL KEEP THE DRIZZLE INTO THE NIGHT TIME HOURS. IT SHOULD BE IN THE SOUTHEAST AND SHOULD GRADUALLY END FROM WEST TO EAST DURING THE NIGHT. THURSDAY AND BEYOND THE MODELS HAVE SEVERAL DIFFERENCES IN TIMING AND STRENGTH OF THE SYSTEMS AND EVEN SOME RUN TO RUN INCONSISTENCIES. THERE IS AN UPPER LEVEL RIDGE THAT WILL MOVE THROUGH THE AREA THURSDAY AND FRIDAY. EXPECT THE TEMPERATURES TO WARM UP AS THERE WILL BE PARTLY CLOUDY SKIES AND WARM ADVECTION. AN UPPER LEVEL SYSTEM IN THE ROCKIES WITH A DEVELOPING SURFACE LOW ON THE HIGH PLAINS WILL BRING MOISTURE BACK TO THE AREA ON SATURDAY. THERE WILL BE WARM ADVECTION AND TEMPERATURES WILL BE WARM ON SATURDAY. THE SURFACE LOW AND COLD FRONT WILL MOVE THROUGH THE FORECAST AREA SATURDAY NIGHT. THE COOLER AIR STARTS TO MOVE INTO THE AREA ON SUNDAY AND TEMPERATURES WILL BE A LITTLE COOLER THAN SATURDAY. THE QUESTION BECOMES PRECIPITATION CHANCES. FORECAST SOUNDINGS SHOW THAT THERE WILL BE A DRY LAYER AND HAVE KEPT PRECIPITATION IN THE SOUTHEAST...BUT THAT IS EVEN A LITTLE QUESTIONABLE. BY SATURDAY NIGHT THE MID LEVELS MOISTEN UP SOME AND THERE WILL BE A FEW MORE CLOUDS WITH MAYBE SOME RAIN IN THE EAST. SUNDAY AND SUNDAY NIGHT LOOK LIKE BETTER CHANCES FOR SOME PRECIPITATION. THIS IS THE FIRST RUN WHERE THE GFS AND THE ECMWF ARE A LITTLE MORE CONSISTENT WITH THE UPPER LOW IN THE CENTRAL TO SOUTHERN PLAINS. THE GFS IS FASTER THAN THE ECMWF. WILL KEEP PRECIPITATION CHANCES FOR SUNDAY AND SUNDAY NIGHT...BRINGING UP THE QUESTION OF PRECIPITATION TYPE. SUNDAY THE TEMPERATURES SHOULD BE WARM ENOUGH THAT EXPECT RAIN BUT TEMPERATURES AT 850MB START TO COOL LATE IN THE AFTERNOON. DURING THE NIGHT THE TEMPERATURES CONTINUE TO COOL AND THE RAIN SHOULD MIX WITH AND MAYBE CHANGE TO SNOW DURING THE NIGHT. THE UPPER LOW SHOULD MOVE TO THE EAST AND EXPECT DRY AND COOL CONDITIONS FOR MONDAY. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1114 PM CST MON DEC 8 2014 THE MAIN CONCERNS FOR BOTH THE KGRI AND KEAR TAF SITES DURING THE PERIOD WILL CENTER AROUND A DEVELOPING STRATUS DECK OFF TO THE NORTHEAST AS WELL AS SUBSEQUENT FOG AND STRATUS DEVELOPMENT DURING THE EARLY MORNING HOURS TODAY. AS AN UPPER LEVEL LOW DEPARTS THE GREAT LAKES REGION...A THIN STRATUS BAND HAS BEGUN TO SHIFT SOUTHWEST ACROSS NEBRASKA. ALTHOUGH NOT A SOLID BAND...SITES UNDER THE STRATUS ARE CURRENTLY OVC AT 1800 FT. EXPECT SITES TO WAIVER AS THIS STRATUS DECK PASSES THUS WENT WITH A TEMPO GROUP. TOWARDS THE MORNING HOURS...SURFACE HIGH PRESSURE WILL BUILD IN ACROSS THE REGION ALLOWING FOR CALM WINDS. THIS COMBINED WITH MOISTURE AT THE SURFACE AND RADIATIONAL COOLING WILL LIKELY PROMOTE FURTHER STRATUS DEVELOPMENT AS WELL AS FOG POTENTIAL. CURRENT THINKING IS THAT REDUCED VISIBILITIES WILL BE WORSE FURTHER WEST. WINDS WILL SWITCH TO THE SOUTH AFTER THE PASSAGE OF THE HIGH PRESSURE SYSTEM BY LATE MORNING ALLOWING FOR CLEARING OF ANY FOG AND STRATUS DECK. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...SALTZMAN LONG TERM...JCB AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1047 PM CST MON DEC 8 2014 .SHORT TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 320 PM CST MON DEC 8 2014 THE PRIMARY FORECAST CONCERNS FOR TONIGHT AND TUESDAY ARE CLOUD COVER AND RESULTING TEMPERATURES. ATTENTION TURNS MORE TOWARD THE POTENTIAL FOR LOW CLOUDS/FOG/DRIZZLE WEDNESDAY INTO THURSDAY. LARGE SCALE 500 MB PATTERN AT 12Z HAD THE FOLLOWING MAIN FEATURES. A TROUGH WAS LOCATED TO OUR EAST/NORTHEAST...A RIDGE STRETCHED FROM THE SOUTHERN ROCKIES INTO ALASKA AND A BROAD TROUGH WAS OUT OVER THE PACIFIC. A CLOSED LOW SHOULD DEVELOP OUT OF THE TROUGH TO OUR EAST IN THE EAST CENTRAL PART OF THE UNITED STATES BY TUESDAY NIGHT. THAT FEATURE WILL THEN LIKELY WOBBLE INTO THE NORTHEAST STATES INTO SATURDAY. IN OUR AREA...GENERAL RIDGING OCCURS IN THE MID LEVELS BUT THERE WILL BE SOME SHORTWAVE ENERGY TRACKING EAST THROUGH THE MEAN RIDGE...MAKING THE PATTERN A BIT MESSY. THE TROUGH IN THE PACIFIC WILL BE PROGRESSIVE..AND BRING VERY WET WEATHER TO MUCH OF THE WEST COAST THIS WEEK. TONIGHT...CLOUD COVER IS PROBLEMATIC. LOW CLOUDS CURRENTLY IN A BAND FROM NORTHERN IOWA ACROSS PARTS OF SOUTH DAKOTA AND INTO WESTERN NORTH DAKOTA. THESE MAY TRY TO SINK SOUTHWARD INTO OUR AREA. THE MOST RECENT RAP AND HRRR MODEL RUNS TEND TO DISSIPATE THIS CLOUDINESS...BUT 12Z HIGH RESOLUTION NAM AND GFS DID BRING THE LOW LEVEL MOISTURE SOUTHWARD. EVENING SHIFT WILL NEED TO MONITOR. A COLD FRONT WAS ALREADY TRACKING SOUTHWARD INTO NORTHEAST NEBRASKA AS OF EARLY THIS AFTERNOON AND WILL CONTINUE TO PUSH SOUTHWARD THIS EVENING. COLD HIGH PRESSURE SHOULD BUILD IN BEHIND THE FRONT FOR TONIGHT. WE EXPECT LOWS TO RANGE FROM THE UPPER TEENS NORTH TO THE LOWER 20S SOUTH. TUESDAY SHOULD BE COLDER THAN TODAY...WITH ONLY POOR TO FAIR MIXING. NORTHEAST WINDS EARLY TURNING TO THE EAST OR SOUTHEAST DURING THE DAY...AND HIGHS SHOULD TOP OUT MAINLY IN THE 30S. AS LOW LEVEL SOUTHERLY FLOW STRENGTHENS...WE WILL HAVE TO MONITOR FOR DEVELOPMENT OF LOW CLOUDS AND POSSIBLE DRIZZLE. THE BEST CHANCE FOR LIGHT RAIN STAYS TO OUR SOUTH IN KANSAS FOR WEDNESDAY/WEDNESDAY NIGHT...BUT AFTER COORDINATION WITH BORDERING OFFICES...ADDED SOME DRIZZLE INTO OUR SOUTHERN COUNTIES FOR WEDNESDAY. THIS COULD BE FREEZING DRIZZLE EARLY WEDNESDAY UNTIL TEMPERATURES RISE ABOVE 32 F. KEPT SOME MENTION OF DRIZZLE INTO WEDNESDAY NIGHT. BEST LIFT MOVES INTO SOUTHERN IOWA/NORTHERN MISSOURI FOR THURSDAY SO DID NOT INCLUDE MENTION OF DRIZZLE IN THAT PERIOD. HIGHS THURSDAY SHOULD REACH INTO THE 40S...POSSIBLY WARMER IF CLOUD COVER IS LESS THAN EXPECTED. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 320 PM CST MON DEC 8 2014 PATTERN IS A BIT MORE ACTIVE IN THIS PERIOD. 500 MB RIDGE WILL BE IN PLACE FROM NEW MEXICO ACROSS OUR AREA AND INTO ONTARIO AT 12Z FRIDAY ...WITH MODELS IN GOOD AGREEMENT WITH STRENGTH AND LOCATION OF A STRONG TROUGH ALONG THE WEST COAST. THE PATTERN OF LOW CLOUDS AND DRIZZLE MAY CONTINUE INTO FRIDAY. WENT SOMEWHAT CONSERVATIVE FOR HIGHS FRIDAY AND SATURDAY...MAINLY LOWER/MID 50S FRIDAY AND MID/ UPPER 50S SATURDAY. INCREASING SOUTHWEST FLOW WILL TRANSPORT MOISTURE AND EVEN SOME INSTABILITY INTO THE CENTRAL PLAINS FOR THE WEEKEND. HAVE SOME MENTION OF SHOWERS FOR AT LEAST PARTS OF THE AREA FROM SATURDAY INTO MONDAY...WITH HIGHEST CHANCES FOR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. ONE MAIN MID LEVEL LOW TRACKS ALONG THE CANADIAN BORDER WHILE THE OTHER MOVES EAST ACROSS NORTH TEXAS. THAT SHOULD KEEP THE HEAVIEST PCPN AMOUNTS OUT OF OUR AREA. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1044 PM CST MON DEC 8 2014 BAND OF MVFR STRATUS IS THINNING AND DISSIPATING ON THE WESTERN EDGE AND SHOULD BE CLEAR OF TAF SITES BY 06Z. HELD ONTO SCATTERED MVFR CEILINGS AS BAND DISSIPATES...WITH NORTH WINDS AROUND 10-15KT EARLY IN THE PERIOD AND SLOWLY DECREASING THROUGH THE NIGHT. FOR THE REST OF THE TAF PERIOD...SCATTERED CEILINGS AT OR ABOVE 15KFT ARE POSSIBLE...WITH WINDS DROPPING TO LIGHT AND VARIABLE AS HIGH PRESSURE MOVES ACROSS THE REGION. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1151 PM CST MON DEC 8 2014 .UPDATE... ISSUED AT 1150 PM CST MON DEC 8 2014 FAIR AMOUNT OF LOW CLOUDS WERE ACROSS THE AREA AND LOW CLOUDS CONTINUE TO MOVE IN FROM SOUTHERN ONTARIO. CLOUD DECK EXTENDS INTO SOUTHERN MN AND INTO IA AND MAY KEEP AREA CLOUDY THROUGH TUE MORN. SURFACE HIGH PRESSURE WAS LOCATED OVER NORTHEAST ND BETWEEN RUGBY AND CANDO. THE HIGH PRESSURE SYSTEM WILL MOVE TO THE WESTERN GREAT LAKES BY TUE AFTERNOON. NO CHANGE TO THE OVERNIGHT LOW TEMP. UPDATE ISSUED AT 1000 PM CST MON DEC 8 2014 LOW LEVEL TRAJECTORY IS FROM THE NORTH/NORTHEAST. FOG LOOP INDICATED CLOUDS OVER SOUTHERN ONTARIO CONTINUE TO ADVECT TO THE SOUTHWEST. WILL HAVE TO RAISE TEMPS OVER THE MN SIDE WITH MORE CLOUDS FOR THE REST OF THE NIGHT AND DECREASE OVER PARTS OF EASTERN ND. UPDATE ISSUED AT 700 PM CST MON DEC 8 2014 SURFACE HIGH PRESSURE WAS LOCATED OVER THE CENTRAL DAKOTAS. WINDS WERE DROPPING OFF OVER EASTERN NORTH DAKOTA WITH LOSS OF INSOLATION. EXPECT TEMPS IN THE NORTHWEST ZONES TO DROP OFF QUICKLY THIS EVENING WITH NO CLOUD COVER. HOURLY TEMPS TWEAKED THIS EVENING WITH CLEARING MOVING IN FROM THE NORTHWEST. LOW TEMPS DECREASED A BIT WITH CLEARING IN THE NORTH. WILL UPDATE LOW TEMP ON NEXT UPDATE. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 335 PM CST MON DEC 8 2014 CLOUD COVER TRENDS AND IF WE GET ANY FOG DEVELOPMENT TONIGHT ARE THE MAIN FORECAST CONCERNS. NORTHWESTERLY FLOW ALOFT CONTINUES AS THE UPPER TROUGH DIGS INTO THE GREAT LAKES. THE SFC LOW HAS BEEN MOVING OFF OF THE ARROWHEAD OF MN AND WILL CONTINUE TO HEAD EAST...ALLOWING HIGH PRESSURE TO BUILD IN FROM ONTARIO INTO THE NORTHERN PLAINS TONIGHT. SOME BREAKS IN THE CLOUDS HAVE STARTED IN THE NORTHERN AND WESTERN CWA...WHICH THE RAP HAS A DECENT HANDLE ON. CLOUDS SHOULD GRADUALLY CLEAR FROM NORTH TO SOUTH THIS EVENING...AND WE SHOULD BE FAIRLY CLEAR BY MORNING. TEMPS WILL DROP INTO THE SINGLE DIGITS...AND WINDS SHOULD BECOME FAIRLY LIGHT AS THE CENTER OF THE HIGH MOVES OVER THE AREA. THE RAP AND HRRR HAVE SIGNS OF SOME PATCHY FOG FORMATION...BUT ALONG WITH THE LIGHT WINDS AND CLEAR SKIES WILL BE DRIER AIR AT THE SFC. THINK THAT CHANCES WILL NOT BE HIGH ENOUGH FOR FOG TO INCLUDE IN THE GRIDS AT THIS POINT...BUT WILL KEEP AN EYE ON IT. TOMORROW...AN EMBEDDED SHORTWAVE WILL MOVE INTO SD...BUT THE COLUMN WILL BE TOO DRY TO DO MUCH AND NONE OF THE MODELS ARE PRODUCING ANY PRECIP. THE SFC HIGH WILL BEGIN TO MOVE OFF TO THE EAST...AND RETURN FLOW WILL SET UP BY MORNING AND CONTINUE THROUGHOUT THE DAY ON TUESDAY. WITH A COLD START AND 850MB TEMPS STILL CLOSE TO ZERO EARLY IN THE DAY...TEMPS WILL STAY IN THE 20S EVEN WITH WARM AIR ADVECTION. THE SOUTH WINDS AND WARM ADVECTION WILL CONTINUE INTO TUESDAY NIGHT AS UPPER RIDGING BUILDS INTO THE REGION. THERE SHOULD BE ENOUGH MIXING TO KEEP LOWS IN THE TEENS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 335 PM CST MON DEC 8 2014 WEDNESDAY THROUGH THURSDAY...UPPER RIDGING WILL CONTINUE TO BUILD ACROSS THE NORTHERN PLAINS. SOUTHERN WINDS WILL CONTINUE AS THE SFC TROUGH REMAINS TO OUR NORTHWEST...BRINGING 850MB TEMPS BACK UP WELL ABOVE ZERO AND SOME CLOSE TO 10 C. THE SPOILER MAY BE IF WE GET STRATUS COMING BACK UP AND REMAINING OVER THE REGION. THE NAM WAS EVEN TRYING TO PUT SOME VERY LIGHT PRECIP OUT THURSDAY OVER THE EASTERN COUNTIES. WILL LEAVE ANY DRIZZLE MENTION OUT FOR NOW BUT BUMPED UP CLOUDS A BIT IN THE FAR EAST. HIGHS SHOULD SLOWLY BECOME WARMER THROUGH WEDNESDAY AND THURSDAY...REACHING BACK TOWARDS THE 30 MARK AND THEN INTO THE MID AND UPPER 30S ON THURSDAY. THURSDAY NIGHT TO MONDAY...MODELS CONTINUE TO AGREE ON 500MB RIDGING ACROSS THE NORTHERN PLAINS FOR THE END OF THE WEEK. NAEFS SHOWS 850MB TEMPS RANGING FROM 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL STARTING EARLY FRIDAY THROUGH LATE SATURDAY...AS 850MB TEMPS REACH TO 12C TO 16C FRIDAY NIGHT. MODELS INDICATE WINDS FROM THE SOUTH INSTEAD OF THE SFC WARMING SW OR WEST PLUS THE POTENTIAL FOR LOW STRATUS LAYER ADVECTING NORTH KEEPING TEMPS COOLER SATURDAY. FOR NOW WILL CONTINUE WITH A BLEND AS CLOUDS WILL MAKE OR BREAK TEMPS...EVEN WITH LOW SUN ANGLE. UPR 30S TO 40 WITH CLOUDS...WITHOUT MID TO UPR 40S POSSIBLE FRIDAY AND SATURDAY. FROPA SUNDAY WILL BRING LIGHT PCPN CHC TO THE FA AND BRING TEMPS DOWN TO NEAR NORMAL WITH HIGHS IN THE LOW 20S BY MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1150 PM CST MON DEC 8 2014 IFR TO MVFR CIGS OF 7 TO 16 HUNDRED FT WERE ACROSS THE FORECAST AREA. LOW LEVEL WINDS WILL BECOME SOUTHEAST BY TUE MORN AND LIKELY ADVECT LOW LEVEL MOISTURE BACK INTO THE AREA. WILL KEEP IFR/MVFR CIGS THROUGH TUE MORN AND MAY LAST INTO TUE AFTERNOON IN NORTHWEST MN. EXPECT CIGS TO RISE INTO THE MVFR CATEGORY BY LATE TUE MORNING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...HOPPES SHORT TERM...JR LONG TERM...JR/JK AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1143 PM EST MON DEC 8 2014 .SYNOPSIS... A WEAKENING LOW NEAR LAKE SUPERIOR WILL DROP SOUTHEAST THROUGH THE AREA TONIGHT TO MERGE WITH A LOW NEAR THE VIRGINIA COAST TUESDAY MORNING THAT WILL STALL NEAR BOSTON THROUGH THURSDAY. HIGH PRESSURE OVER THE UPPER MIDWEST WEDNESDAY WILL EVENTUALLY SPREAD UP THE OHIO VALLEY BY THE WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... LATEST HRRR MODEL RIGHT ON TARGET WITH PRECIPITATION EXPANDING NORTH INTO THE CENTRAL PORTIONS OF THE FORECAST AREA. MADE SOME ADJUSTMENTS TO PRECIPITATION TO ACCOUNT FOR THIS ACTIVITY. COLDER AIR PUSHING EAST WITH THE COLD FRONT OVERNIGHT AND WILL CHANGE PRECIPITATION OVER TO SNOW FROM WEST TO EAST. TEMPERATURES STILL LOOK REASONABLE AS DEW POINTS ARE CURRENTLY IN THE MIDDLE THIRTIES BEHIND THE WEAK WARM FRONT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... THE SITUATION ON TUE LOOKS SIMILAR TO THE LATTER PART OF TONIGHT WITH TEMPS NOT QUITE COLD ENOUGH TO SUPPORT JUST SNOW. CAN SEE THE PRECIP WAVERING BACK AND FORTH ON TUE. BESIDES...THE PRECIP WILL BE LIGHT SO THINK SNOW ACCUMULATION WILL STAY UNDER A HALF AN INCH. BY TUE NIGHT...THE BETTER ENERGY AND DEEPER MOISTURE WILL BE SHIFTING EAST TOWARD THE EAST COAST SYSTEM. TEMPS SHOULD BE GETTING COLD ENOUGH FOR JUST SNOW BUT THE THREAT SHOULD BE SHIFTING INTO MAINLY JUST THE SNOWBELT. TEMPS ALOFT ONLY GET COLD ENOUGH FOR A LITTLE LAKE ENHANCEMENT. SNOW ACCUMULATION WILL MAINLY BE IN THE SNOWBELT AND NEARBY AREAS WITH MAX AMOUNTS OF ABOUT 2 TO MAYBE 3 INCHES LOOKING POSSIBLE IN THE FAVORED AREAS OF THE SNOWBELT IN NW PA. THE WEATHER PATTERN WILL REMAIN NEARLY STALLED INTO THU SO NOT A LOT WILL CHANGE THRU THEN. A GOOD CHANCE FOR LAKE ENHANCED SNOW SHOWERS WILL PREVAIL THRU THU WITH ACCUMULATION AMOUNTS GENERALLY STAYING ON THE LIGHTER SIDE WITH ABOUT 1 TO 3 INCHES POSSIBLE IN ANY GIVEN 12 HOUR PERIOD IN THE SNOWBELT WITH DUSTINGS OF ACCUMULATION POSSIBLE IN NEARBY AREAS. TEMPS WILL STAY ABOUT 5 DEGREE BELOW NORMAL THRU THE PERIOD. && .LONG TERM /FRIDAY THROUGH MONDAY/... GENERALLY DRY WITH A WARMING TREND FOR THIS PERIOD. THE SURFACE RIDGE AND UPPER RIDGE WILL BE BUILDING IN ACROSS THE AREA STARTING FRIDAY AND IT WILL MOVE EAST OF THE AREA BY MONDAY. ON FRIDAY A WEAK SURFACE TROF WILL BRUSH THE EASTERN PORTION OF THE FORECAST AREA. KEPT SLIGHT CHANCE POPS WITH A THREAT OF FLURRIES AND POSSIBLY SPRINKLES IN THE AFTERNOON EAST OF CLEVELAND. THE 12Z ECMWF IS A LITTLE MORE PESSIMISTIC IN CONTINUING SOME QPF ON FRIDAY AS IT IS A LITTLE SLOWER IN MOVING IN THE RIDGE. AT THIS TIME LEANING MAINLY DRY. THE ECMWF MODEL WAS TRYING TO HINT AT SOME QPF OVER THE WEEKEND. THIS DOES NOT SEEM REASONABLE BASED ON THE DRY AIR...RIDGING AND NO OMEGA. THE GFS AND CANADIAN MODEL KEEPS IT DRY...SO WENT THAT DIRECTION. WENT CLOSE TO WPC GUIDANCE FOR THE TEMPERATURES. TEMPERATURES WILL BECOME ABOVE NORMAL BY SUNDAY. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... IFR CEILINGS ARE MOVING INTO NW OHIO AND WILL CONTINUE TO MOVE EASTWARD WITH A WEAKENING COLD FRONT. THERE IS SOME VERY LIGHT RAIN/DRIZZLE OVER A LARGE PORTION OF THE AREA AND EXPECT THIS TO CONTINUE THROUGH MUCH OF THE OVERNIGHT HOURS. THE KERI AREA WILL LIKELY BE THE LATEST GETTING THE IFR CONDITIONS SINCE THERE WILL BE A DECENT DOWNSLOPING COMPONENT THROUGH THE NIGHT. A SECONDARY SURGE OF COOLER AIR WILL ARRIVE BY EARLY TUESDAY AFTERNOON AS THE UPPER LEVEL TROUGH PASSES. WINDS WILL SHIFT AROUND TO THE NORTH AS IT PASSES. SOME LIGHT RAIN MAY DEVELOP WITH THE UPPER LEVEL TROUGH. TIMING AND INTENSITY IS UNCERTAIN SO ONLY PLACED A VICINITY SHOWER IN THE TAFS AT THIS POINT. WILL HAVE TO MONITOR FOR A CHANGE TO SNOW BY TUESDAY EVENING...ESPECIALLY NE OHIO INTO NW PA. .OUTLOOK...NON VFR MAINLY IN NE OHIO AND NW PA TUESDAY NIGHT INTO THUR WITH LINGERING SNOW SHOWERS. && .MARINE... .SYNOPSIS... A WEAKENING LOW NEAR LAKE SUPERIOR WILL DROP SOUTHEAST THROUGH THE AREA TONIGHT TO MERGE WITH A LOW NEAR THE VIRGINIA COAST TUESDAY MORNING THAT WILL STALL NEAR BOSTON THROUGH THURSDAY. HIGH PRESSURE OVER THE UPPER MIDWEST WEDNESDAY WILL EVENTUALLY SPREAD UP THE OHIO VALLEY BY THE WEEKEND. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...ADAMS NEAR TERM...LOMBARDY SHORT TERM...ADAMS LONG TERM...KIELTYKA AVIATION...MULLEN MARINE...MAYERS
AREA FORECAST DISCUSSION
NWS NORMAN OK
258 AM CST TUE DEC 9 2014 .DISCUSSION... IN RESPONSE TO VERY SHALLOW SFC MOISTURE ACROSS TEXOMA AND THE RED RIVER VALLEY... DENSE FOG WILL REMAIN IN PLACE ACROSS SRN OK AND WRN N TX. RECENT RAP AND HRRR OUTPUT OF VIS AND BOUNDARY LAYER RH VALUES HINT AT FOG EXPANSION NORTHWARD INTO CENTRAL OK FOR AN HOUR OR TWO NEAR SUNRISE BEFORE CONDITIONS IMPROVE THROUGH THE MID TO LATE MORNING HOURS. IN RESPONSE TO THIS... HAVE MADE THE DECISION TO EXTEND THE CURRENT DENSE FOG ADVISORY THROUGH 16Z (10AM CST). AT THE MOMENT... NOT CONVINCED OF WIDESPREAD DENSE FOG REACHING FARTHER NORTH THAN THE CURRENT ADVISORY. HOWEVER... SOME POCKETS OF SHORT DURATION DENSE FOG WILL BE POSSIBLE OUTSIDE THE ADVISORY. WITH THAT IN MIND... AND GIVEN THE CURRENT VIS TRENDS THROUGH 230AM CST... THERE ARE NO PLANS TO EXPAND THE ADVISORY FARTHER NORTH AT THE MOMENT. WE WILL CONTINUE TO WATCH VIS TRENDS CLOSELY THIS MORNING IN THE EVENT AN EXPANSION IS NECESSARY. FOR THE REST OF TODAY... HELPING CLEAR FOG SOUTHWARD THROUGH THE MORNING WILL BE ANOTHER WEAK SFC BOUNDARY... MUCH LIKE THE ONE YESTERDAY. WINDS WILL SLOWLY BACK TO THE EAST ACROSS NRN AND CENTRAL OK THROUGH THE AFTN. TEMPS WILL CLIMB INTO THE 50S FOR HIGHS. OVERNIGHT... AS THE H500 RIDGE BROADENS ACROSS THE WRN U.S... A WEAK H500 SHORT WAVE TROUGH WILL CONTINUE TO APPROACH FROM THE WEST ACROSS ERN NM AND WEST TX. THIS WILL OPEN UP SOME MODEST SFC MOISTURE RETURN FROM THE GULF. PAIRED WITH SOME WEAK LL ISENTROPIC ASCENT AS THE TROUGH SWINGS THROUGH... SOME LIGHT SHOWERS/DRIZZLE MAY DEVELOP ACROSS THE RED RIVER VALLEY LATE WED INTO THU. SLIGHT CHANCES FOR SHOWERS AND DRIZZLE ACROSS PORTIONS OF SOUTHERN AND CENTRAL OK WILL CONTINUE THROUGH FRI AS THE RIDGE OVER THE MIDWEST STRENGTHENS... LEAVING THE SRN PLAINS WITHIN THE WARM SECTOR AND CONTINUAL SFC MOISTURE RETURN. OVERALL... MOST WILL REMAIN DRY... WITH MILD TEMPERATURES CONTINUING. FOR THE WEEKEND... LONG RANGE GUIDANCE... GFS/GFS13KM/ECMWF/CA... HAVE CONTINUED TO SHOW DECENT CONTINUITY OVER THE PAST COUPLE RUNS WITH RESPECT TO THE DEEP H500 TROUGH MOVING INTO THE PLAINS SAT. INCREASED PRECIP CHCS SAT NIGHT INTO SUN. EXPECT SOME RUMBLES OF THUNDER ON SUNDAY. A DECENT LOW... BUFR SOUNDINGS FROM KSPS TO KOUN SHOW COLD TEMPS ALOFT... ENOUGH FOR SOME MINOR ELEVATED INSTABILITY SUPPORTIVE OF SOME ISOLATED THUNDER WITHIN THE RAIN SHOWERS THAT DEVELOP. NOT EXPECTING ANY SIGNIFICANT WEATHER... BUT THE POTENTIAL FOR SOME WELCOME RAINFALL ACROSS THE REGION. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 55 36 55 45 / 0 0 10 10 HOBART OK 57 40 55 46 / 0 0 10 10 WICHITA FALLS TX 58 42 58 48 / 0 0 10 20 GAGE OK 54 37 54 42 / 0 0 10 10 PONCA CITY OK 48 32 50 42 / 0 0 10 20 DURANT OK 60 40 55 45 / 0 0 0 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR OKZ036-037- 044>048-050>052. TX...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR TXZ083>090. && $$ 30/04
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
214 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE FORMING EAST OF THE CAROLINA COAST WILL MOVE UP THE EAST COAST AND BRING AN EXTENDED PERIOD OF WINTRY WEATHER TO THE REGION. BLUSTERY NORTHWEST FLOW WITH AREAS OF SNOW SHOWERS WILL FOLLOW THIS STORM FOR THE SECOND HALF OF THE WEEK. && .NEAR TERM /THROUGH TODAY/... PRECIP LIFTING NORTH INTO THE SC MTNS LATE THIS EVENING IN REGION OF LG SCALE FORCING AHEAD OF LEAD SHORTWAVE OVR THE S APPALACHIANS. SATL-DERIVED PWAT LOOP SHOWING DEEP LVL MOISTURE LIFTING NORTHWARD THRU THE MID ATLANTIC REGION ALONG AXIS OF EASTERLY LL JET. HAVE ACCELERATED THE ARRIVAL OF PRECIP BASED ON RADAR TRENDS AND ALSO HAVE TRENDED PTYPE TO MOSTLY SNOW ACROSS THE SPINE OF THE ALLEGHENIES BASED ON UPSTREAM REPORTS AND LATEST HRRR OUTPUT...WHICH SUGGESTS A STRIPE OF A COUPLE INCHES OF SNOW IS NOW POSSIBLE LATE TONIGHT FROM SOMERSET/BEDFORD CO NEWRD INTO THE CENTRAL MTNS. FURTHER EAST...STILL THINKING A PERIOD OF FZRA IS MOST LIKELY OVR THE SUSQ VALLEY EARLY TUE AM. BLEND OF 18Z CONSALL AND LATEST LAMP/HRRR OUTPUT SUGGEST TEMPS BY DAWN WILL RANGE FROM THE U20S OVR THE ALLEGHENY MTNS...TO PERHAPS JUST ABV FREEZING OVR LANCASTER CO. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... STILL A VERY UNCERTAIN FORECAST DESPITE HOW CLOSE WE ARE TO THE ONSET OF THINGS. A LOW DEVELOPING OFF THE CAROLINA COAST WILL MOVE DUE NORTH AND UP ALONG THE NJ COAST TUESDAY INTO WEDNESDAY. GIVEN THIS SLIGHTLY OFFSHORE TRACK...EASTERN PA WILL BEAR THE BRUNT OF THE STORM WITH THE POTENTIAL FOR HEAVY RAIN OVR SE PA...AND POSSIBLY SOME SIG SNOW OVER THE HIGHER ELEVATIONS OF TIOGA/SULLIVAN/SCHUYLKILL COUNTIES. WILL LIKELY BE ABLE TO CANCEL WINT WX ADVISORY BEFORE 18Z...AS NEARLY ALL GUIDANCE INDICATES TEMPS RISING WELL ABV FREEZING BY LATE AM. MAIN CONCERN WILL BE THE EARLY AM COMMUTE FOR A MIXTURE OF SNOW AND FZRA. MAIN FCST ISSUE REMAINS HOW FAR WEST SIG PRECIP CAN BE DRAGGED INTO CENTRAL PA. MODELS ARE CONSISTENT IN A PRETTY SHARP BACK EDGE CUTTING OFF MOST OF THE PRECIP SOMEWHERE BETWEEN STATE COLLEGE AND PERHAPS WILLIAMSPORT-HARRISBURG. WITH THE UNCERTAINTY STILL HIGH...WE KEPT THE WINTER STORM WATCH UP FOR OUR HIGHER ELEVATIONS FROM TIOGA SOUTH DOWN INTO SCHUYLKILL COUNTY...EMPHASIZING THE BEST CHANCE FOR HEAVY WET SNOW BEING OVER THOSE HIGHER ELEVATIONS. LATEST RAP...21Z SREF AND 00Z NAM ALL SUGGEST ENOUGH WARM AIR OVERSPREADS EASTERN PA TO TURN THE BULK OF THE PRECIP TO RAIN BTWN LATE AM AND TUE AFTN OVR OUR NE COUNTIES. HOWEVER...DEVELOPING DEFORMATION BAND ON THE NW PERIPHERY OF MID LVL LOW COULD STILL POTENTIALLY PRODUCE SIG SNOW TUE NIGHT FROM TIOGA CO SOUTH THRU SCHUYLKILL CO. THE LOW IS EXPECTED TO REACH THE NJ COAST AROUND MID DAY TUESDAY AND SLOW DOWN OR EVEN STALL FOR PERHAPS A DAY OR MORE AS THE UPPER LOW CAPTURES THE SYSTEM. WHILE MUCH OF OUR FORECAST AREA WILL LIKELY WARM ENOUGH TO MAKE FOR JUST PLAIN RAIN DURING THE DAY TUESDAY...THIS WILL EVENTUALLY CAUSE COLDER AIR TO COME IN AT ALL LEVELS AND CHANGE THE MIXED PRECIP BACK TO MAINLY SNOW TUESDAY NIGHT AND INTO WED. IT`S STILL UNCLEAR HOW MUCH PRECIP WILL RESULT AS THE MODELS DIFFER GREATLY ON THE DEVELOPMENT OF A POSSIBLE DEFORMATION ZONE. THE SOLUTIONS FALL BETWEEN THE ECMWF THAT TARGETS MY NWRN ZONES EVEN THROUGH WED INTO THURSDAY...TO THE GFS THAT SHOWS ALMOST NO PRECIP WRAPPING BACK. I KEPT A GOOD CHANCE OF MAINLY LIGHT QPF IN THE FORECAST THROUGH THURSDAY BEFORE TAPERING OFF THE ACTIVITY FOR THE REMAINDER OF THE WEEK. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... WITH THE LOW MOVING VERY SLOWLY IF AT ALL...THE CHANCES FOR AT LEAST SOME LIGHT SNOW WILL REMAIN HIGH WEDNESDAY INTO THURSDAY. I GENERALLY KEPT AMOUNTS LOW...DEPENDENT ON THE FORMATION OF THE DEFORMATION ZONE MENTIONED EARLIER...OR NOT. BY THE END OF THE WEEK GUIDANCE IS IN DECENT AGREEMENT FOR THE UPPER LOW TO NUDGE EAST ENOUGH TO HAVE US BEGINNING TO ENJOY THE INFLUENCE OF SOME RIDGING AND FAIRER CONDITIONS. TEMPS WILL BE COOLER THAN NORMAL THROUGH THE END OF THE WEEK BEFORE BEGINNING TO MODERATE FOR THE WEEKEND. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... LOW PRESSURE OFF THE SOUTHEAST COAST WILL TRACK NORTH NORTHWESTWARD EARLY THIS MORNING AND DEEPEN JUST OFF THE NEW JERSEY COAST THIS AFTERNOON...THEN DRIFT NORTH TOWARD LONG ISLAND TONIGHT INTO WEDNESDAY. INITIAL SHOT OF MIXED PCPN /SN-PL-FZRA/ CURRENTLY IMPACTING AIRFIELDS ALONG AND SE OF AOO-UNV-IPT LINE SHOULD START TO TRANSITION TO/MIX WITH RAIN BTWN 12-15Z. BFD AND JST WILL BE ON THE FAR WRN EDGE OF THE INITIAL PCPN SHIELD ASSOCD WITH THE DEVELOPING COASTAL STORM AND MAY NOT SEE ANY PCPN UNTIL TONIGHT. CONFIDENCE IS HIGH IN WIDESPREAD LOW MVFR TO IFR CIGS AND MEDIUM FOR TIMING AND PTYPE TRANSITIONS THROUGH MID MORNING. WENT WITH -RASN OR -RA AS SIG WX TYPES FROM THE LATE MORNING THROUGH THE AFTERNOON WITH LOW CONFIDENCE ON THE SN. THERE IS A BETTER CHANCE OF ANOTHER PTYPE TRANSITION/MIX FROM MOSTLY RA TO SNRA OR JUST ALL SN TONIGHT ON THE BACKSIDE OF DEEPENING LOW AND MAY ADDRESS THIS WITH THE 12Z ISSUANCE. WINDS WILL BECOME A FACTOR AT ERN SITES TONIGHT SUSTAINED AT 15-20KT WITH HIGHER GUSTS. THIS STORM WILL BE SLOW MOVING AND CONTINUE TO INFLUENCE THE WEATHER PATTERN IN CENTRAL PA THROUGH AT LEAST THURSDAY WITH ANOTHER ROUND OF WRAP AROUND SNOWS POSSIBLE. RETURN OF HIGH PRESSURE SHOULD SPELL SOME MARGINAL IMPROVEMENT INTO THE WEEKEND. OUTLOOK... WED-THU...MVFR/IFR IN PERIODS OF SNOW. STRONG N-NW WINDS 15-20KTS WITH HIGHER GUSTS POSSIBLE. FRI...MVFR CIGS/-SHSN NW...BCMG VFR EAST. SAT...VFR WITH HIGH PRESSURE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WATCH FROM 5 AM EST EARLY THIS MORNING THROUGH WEDNESDAY MORNING FOR PAZ037-041-042-053-058. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR PAZ010>012-017>019-024>028-033>036-045-046-049>052-056-057-059- 063>066. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...LA CORTE AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1051 PM CST MON DEC 8 2014 .UPDATE... ISSUED AT 904 PM CST MON DEC 8 2014 SHORT TERM CLOUD TRENDS HAVE BEEN CHALLENGING TO SAY THE LEAST. STRONG PUSH OF CLEARING HAS OCCURRED FROM THE JAMES VALLEY THROUGH I 29 CORRIDOR IN THE VICINITY OF THE LOW LEVEL RIDGE AXIS... NARROWING AND BACKING BAND OF LOWER CLOUDS ACROSS THE FAR WESTERN CWA...WHILE BREAKS HAVE DEVELOPED IN CLOUDS ACROSS THE EAST...BUT FAR LESS IMPRESSIVELY. IN CLEARING...TEMPS HAVE FALLEN MUCH FASTER AS HAVE THE WINDS...WHILE STILL GUSTY AND RELATIVELY WARMER UNDER CLOUDS TO EAST. CLEARING WEDGE WILL CONTINUE TO WORK SOUTHWARD LATE THIS EVENING WHILE A SLOWER BACKING TO NARROW BAND OF LOW CLOUDS WORKS OUT OF SOUTH CENTRAL. WILL SEE CLOUDS AGAIN INCREASE FROM THE NORTH ALONG/EAST OF THE I29 CORRIDOR AS FINAL LOBE WRAPS SOUTHEAST ACROSS THE AREA...WITH GENERAL NORTH TO NORTHEAST FLOW IN CLOUD BEARING LEVELS. DOWNSLOPE OFF THE RIDGE WITH NARROWING MOISTURE DEPTH COULD CREATE A FEW ISSUES WORKING CLOUDS MUCH SOUTHWEST PAST KFSD...AND EVEN TO KFSD. COULD POSSIBLY SEE A FEW FLURRIES START TO FLUTTER THROUGH SKIES IN THE NORTHEAST AFTER 08Z...BUT AT THIS POINT NOT MUCH MERIT IN THE MENTION WITH TEMPS IN THE CLOUD LAYER SOMEWHAT MARGINAL. HAVE TRIMMED A COUPLE OF LOWS DOWN A BIT IN VICINITY OF RIDGE AXIS AND CLEARING...BUT IN GENERAL EVEN ADVECTION WILL TAKE LOWS TO EARLIER LEVELS...JUST A BIT QUICKER OF A START THIS EVENING TO THOSE ENDS. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 244 PM CST MON DEC 8 2014 THE MAIN QUESTION THROUGH THIS EVENING IS THE STATUS OF THE LOW CLOUD COVER WHICH HAD BEEN SPREADING SOUTH OVER THE AREA. THAT SPREAD HAS DONE A NEAR HALT AS THE MOISTURE ADVECTION RUNS INTO THE HEATED AIR NEAR THE MISSOURI RIVER. IT SEEMS WITH THE START OF EARLY EVENING COOLING THAT THE DECK WOULD AGAIN START SPREADING SOUTH. CLEARING OF THE LOW CLOUDS HAS CONTINUED TO PROGRESS SOUTH ACROSS NORTH DAKOTA AND WAS STARTING TO GET INTO FAR NORTHERN SOUTH DAKOTA AT 20Z. BOTH THE NAM AND RAP SUGGEST THE 925 MB FLOW WILL CONTINUE TO GO STRAIGHT NORTHERLY AND CONTINUE THUS OVER THE AREA THROUGH 06Z/MIDNIGHT...THOUGH DECREASING SLOWLY DURING THE EVENING. EXPECT THIS WILL GIVE THE DRYING CONTINUED TRANSPORT SOUTH ACROSS THE AREA DURING THE EVENING AND NOT ALLOW THE SOLID CLOUD COVER TO GET ALL THE WAY TO THE RIVER...OR OF IT BRIEFLY DOES...IT SHOULD CLEAR OUT AGAIN FAIRLY QUICKLY. AM PLANNING FOR A LITTLE INCREASE IN THE LOW CLOUDS THERE BUT WITH THE WARM AIR THERE CURRENTLY AND DRYING FROM THE NORTH DURING THE EVENING...HAVE KEPT THE INCREASE VERY MODEST BEFORE IT CLEARS OUT EVERYWHERE TONIGHT. TEMPERATURES WILL COOL STEADILY TONIGHT GIVEN THE CLEARING AND DROPOFF IN WINDS...WITH LOWS BEING REACH ABOUT SUNRISE AT 8 AM. WINDS BY THEN SHOULD BE PRETTY LIGHT THOUGH WITH A 5 TO 5 MPH NORTHERLY BREEZE IN THE EAST LINGERING TO SUNUP. TUESDAY WILL BRING AN INCREASE IN HIGH AND SOME MIDDLE CLOUDS WITH UPPER LEVEL SHORT WAVE DRIFTING INTO THE AREA. HAVE GONE PRETTY CONSERVATIVE IN CLOUD COVER AND IF THEY HIGHER CLOUDS ARE THICK ENOUGH IT COULD GET MOSTLY CLOUDY FOR PART OF THE DAY. IN ANY EVENT HEATING BY THE DECEMBER SUN WILL NOT BE ABLE TO TAKE ADVANTAGE OF MUCH OF THE WARMING UPSTAIRS EVEN WITH NO SNOW COVER...AND FORECAST HIGHS WILL REMAIN AROUND 30 NORTHEAST TO THE LOWER 40S SOUTHWEST. WINDS WILL BE FAIRLY LIGHT THOUGH...WITH THE DEVELOPING SOUTHEASTERLY SURFACE BREEZE PICKING TO 10 PLUS IN THE AFTERNOON WEST OF THE JAMES RIVER. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 244 PM CST MON DEC 8 2014 MEDIUM AND EXTENDED FORECAST CONTINUES TO LOOK VERY WARM AND MOSTLY DRY. TUESDAY NIGHT INTO WEDNESDAY...A MINOR SHORTWAVE WILL MOVE ACROSS THE REGION. SOUNDINGS CONTINUE TO SHOW LIMITED MOISTURE WITH THIS WAVE...WITH AN INCREASE IN MID-LVL CLOUDS AND VIRGA POSSIBLE GIVEN DRY SUB-CLOUD LAYER. THE WARMUP BEGINS TO BUILD ON WEDNESDAY BEHIND THIS SHORTWAVE ENERGY. AS LOW LVL TEMPERATURES BUILD...SURFACE WINDS WILL SLOWLY BEGIN TO VEER SOUTHWEST THROUGH THE DAY. WARM AIR WILL BE SLOW TO MIX TO THE SURFACE ON WEDNESDAY...BUT NEAR 40 READINGS SHOULD BE ATTAINABLE. THURSDAY THROUGH SATURDAY LOOK TO BE VERY WARM AS DEEP SOUTHWESTERLY FLOW PULLS BOTH MOISTURE AND WARM AIR OVER MUCH OF THE CENTRAL CONUS. IT CONTINUES TO LOOK LIKE STRATUS WILL DEVELOP AND MOVE NORTHWARD INTO THE REGION BY THURSDAY. TEMPERATURES WILL PROGRESSIVELY WARM EACH AFTERNOON...WITH THE 40S LIKELY ON THURSDAY AND 40S AND 50S ON FRIDAY. TEMPERATURES MAY NOT FALL VERY FALL FRIDAY NIGHT INTO SATURDAY...AND CURRENT LOWS MAY STILL BE TOO LOW. THE DEEP SOUTHERLY FLOW AND SUBSTANTIAL MOISTURE SHOULD NOT ALLOW FOR ANY EXTREME JUMP ON SATURDAY...BUT A GRADUAL WARMING INTO THE MID 50S AND POTENTIALLY EVEN DRIZZLE. A COLD FRONT WILL SWING THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY...DROPPING TEMPERATURES BACK NEAR THEIR SEASONAL NORMALS. THE CHANCES FOR PRECIPITATION AS THIS FRONT MOVES THROUGH CONTINUE TO BE LOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1051 PM CST MON DEC 8 2014 MVFR CEILINGS EXPECTED TO SLOWLY SHIFT SOUTH-SOUTHWESTWARD THROUGH CENTRAL/EASTERN PORTIONS OF THE FORECAST AREA THROUGH THE MORNING. MVFR CEILINGS MOST LIKELY TO AFFECT KFSD TAF LOCATION FOR PROLONGED PERIOD THROUGH MID MORNING. LOWER CONFIDENCE FOR KHON/KSUX DUE TO UNCERTAINTY REGARDING WESTWARD EXTENT OF THE LOWER CLOUD DECK. MODELS PROJECT THE STRATUS LAYER TO GRADUALLY THIN WEST TO EAST AFTER SUNRISE AS LOW LEVEL RIDGE AXIS WORKS THROUGH THE AREA. THUS IMPROVEMENT TO VFR GRADUALLY EXPECTED ALONG I-29 CORRIDOR BY 16-18Z WITH VFR CONDITIONS THEN PREVAILING THROUGH THE END OF THE PERIOD. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...CHAPMAN SHORT TERM... LONG TERM...DUX AVIATION...JH
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
330 AM CST TUE DEC 9 2014 .DISCUSSION... UPPER LEVEL SYSTEM OVER INDIANA WILL DROP SOUTHEASTWARD THIS MORNING AND WILL MOVE ACROSS EASTERN TN THIS AFTERNOON. THOUGH THE BETTER DEFORMATIONAL INFLUENCES WILL BE TO THE LEFT OF THE TRACK...WE DO PICK UP SOME DESCENT CURVATURE AND SHEAR ON THE RIGHT SIDE OF THE TRACK. LATEST SATELLITE IMAGERY SHOWS THE LOWER TO MID LEVEL CLOUDINESS TO OUR NORTH ACROSS IL...IN AND NRN MO. LATEST HRRR AND MODEL DATA BOTH CONCUR WITH SCATTERED LIGHT SHOWER ACTIVITY ACROSS THE EASTERN PORTIONS OF THE MID STATE THROUGH TODAY AND INTO TONIGHT. AN EXAMINATION OF FREEZING LEVELS DOES SUPPORT SNOW FOR AREAS GENERALLY ABOVE 1500 FT MSL AFT 18Z TODAY. BY 00Z THE ENTIRE EASTERN THIRD OF THE MID STATE...WHERE THE CHANCES OF PRECIP EXISTS...WILL BE SNOW. AMOUNTS LOOK VERY LIGHT AND NO ADVISORIES OR SPS PRODUCTS ARE NEEDED. FURTHERMORE...SFC TEMPS SHOULD GENERALLY REMAIN ABOVE FREEZING UNTIL LATE TONIGHT. A LOW CHANCE OF SNOWFALL WILL CONTINUE ACROSS THE EAST FOR TONIGHT BUT AMOUNTS AGAIN WILL BE LIGHT. FOR THE FCST...WILL INCLUDE A CHANCE OF RAIN AND SNOW EASTERN THIRD FOR THIS MORNING...JUST RAIN SOUTHEAST. THIS AFTERNOON...WILL TREND THE GRIDS TOWARD A CHANCE OF ALL SNOW FOR THE EASTERN AREA BY EVENING. 850 MB TEMPS WILL BE WELL BELOW 0C AND FREEZING LEVELS WILL BE DROPPING AS WELL AS SFC TEMPS WHICH WILL BE FALLING THROUGH THE 30S. IMPROVING CONDITIONS WILL OCCUR ON WEDNESDAY WITH PARTLY CLOUDY SKIES EXPECTED. IN FACT...MOSTLY CLEAR AND MOSTLY SUNNY SKIES ARE ON TAP FOR WED NT AND THU. TEMPS THROUGH THE EXTENDED WILL REMAIN BELOW NORMAL AS A UNIFORM NORTHERLY FLOW CONTINUES WITH ONLY A VERY SLOW INCREASE IN HEIGHT VALUES. IN THE EXTENDED FCST...HEIGHT VALUES WILL CONTINUE TO INCREASE WITH A RIDGE AXIS REACHING THE AREA ON SATURDAY. THIS WILL EQUATE TO DRY CONDITIONS AND A WARMING TREND. LATE IN THE EXTENDED HOWEVER...A COLD FRONT WILL BRING AN INCREASE IN CLOUDINESS AND A LOW CHANCE OF SHOWER ACTIVITY ON MONDAY. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 43 32 43 29 / 10 05 05 05 CLARKSVILLE 42 30 42 27 / 10 05 05 05 CROSSVILLE 40 29 39 26 / 30 30 10 05 COLUMBIA 44 31 44 29 / 10 05 05 05 LAWRENCEBURG 45 30 44 27 / 10 05 05 05 WAVERLY 43 31 42 27 / 10 05 05 05 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
356 AM CST TUE DEC 9 2014 .DISCUSSION... AS OF 3 AM...WIDESPREAD DENSE FOG HAS SETTLED IN OVER ALL BUT THE SOUTHERN ZONES WHERE HIGH CLOUDS WERE IMPEDING RADIATIVE HEAT LOSS A BIT. STILL WE EXPECT FOG TO CONTINUE TO EXPAND SOUTHWARD BEFORE SUNRISE. ACROSS THE NORTHERN 2/3RDS OF THE CWA...CONDITIONS ARE EXTREMELY FAVORABLE FOR DENSE FOG AND IT IS LIKELY THAT IT WILL BE SLOWER THAN USUAL TO LIFT AND BURN OFF. THE DENSE FOG ADVISORY EXPIRES AT 10AM...BUT IT MAY NEED TO BE EXTENDED AN HOUR OR TWO FROM I-20 NORTH. WINDS BELOW 850MB THIS MORNING ARE EXPECTED TO BE VERY LIGHT...IF NOT NEARLY CALM...WHICH MEANS THE LOW ANGLE DECEMBER SUN WILL BE THE ONLY THING WORKING TO LIFT THE FOG AND LOW CLOUDS TODAY. CLOUDS WILL BE SLOWEST TO ERODE TODAY FROM ROUGHLY I-20 TO THE RED RIVER...BUT OUT OF ALL OF THE MODEL GUIDANCE...ONLY THE RUC HAS THESE CLOUDS HANGING IN THROUGH EARLY AFTERNOON. OBVIOUSLY THE EXACT EROSION OF THE LOW CLOUDS WILL HAVE HUGE IMPLICATIONS ON HIGH TEMPS TODAY...BUT AM LEANING TOWARD THE RUC SOLUTION AND WILL KEEP TEMPS SEVERAL DEGREES BELOW TRADITIONAL GUIDANCE FROM I-20 NORTHWARD. IF AND WHERE CLOUDS HOLD IN ALL AFTERNOON...HIGHS WILL LIKELY ONLY BE IN THE LOWER 50S. INCREASING MID-HIGH LEVEL MOISTURE/CLOUDS TONIGHT WILL LIMIT RADIATIONAL COOLING AT THE SURFACE WHICH SHOULD NIX THE DENSE FOG POTENTIAL. THIS MOISTURE WILL BE ARRIVING IN ADVANCE OF A WELL DEFINED SHORTWAVE TROUGH THAT IS CURRENTLY NEAR BAJA. WHILE THIS SYSTEM IS FORECAST TO WEAKEN AS IT ENTERS MORE CONFLUENT FLOW ACROSS OUR REGION...WATER VAPOR LOOP SHOWS IT HAS TAPPED INTO A HEALTHY AMOUNT OF MID-UPPER LEVEL PACIFIC MOISTURE AND IS SLINGING IT INTO TEXAS. THE ECMWF/NAM ARE THE MOST AGGRESSIVE WITH INCREASING MOISTURE PROFILES OVER OUR REGION WEDNESDAY AND WEDNESDAY NIGHT...AND GIVEN THE LATEST SATELLITE TRENDS AM INCLINED TO BELIEVE THEM. THEREFORE HAVE INCREASED THE CHANCES FOR LIGHT RAIN SHOWERS WEDNESDAY AND INTO THURSDAY. THERE WILL BE A LAYER OF DRIER AIR BELOW THIS MOISTURE THAT WILL KEEP PRECIP FROM REACHING THE GROUND WEDNESDAY...BUT THIS LAYER SHOULD SATURATE FROM TOP DOWN BY WEDNESDAY NIGHT. WE HAVE INTRODUCED SPRINKLES INTO THE FORECAST WEDNESDAY AFTERNOON...AS MEASURABLE PRECIP WILL BE UNLIKELY INITIALLY. THE BEST CHANCES OF MEASURABLE RAIN WILL OCCUR WEDNESDAY NIGHT AND THURSDAY AND PRIMARILY OVER THE SOUTHERN HALF OF THE CWA WHERE A TINY AMOUNT OF MID LEVEL INSTABILITY WILL BE AVAILABLE. QPF WILL BE LOW WITH THIS SYSTEM AND WE EXPECT LESS THAN 1/10 OF AN INCH. HIGHS WEDNESDAY AND THURSDAY LOOK TO REMAIN SEASONABLY COOL AS THICK CLOUD COVER WILL INHIBIT DAYTIME WARMING. AS THE SYSTEM EXITS THURSDAY EVENING...THE MID TO UPPER LEVELS WILL DRY OUT SUBSTANTIALLY. HOWEVER THE LOW LEVELS WILL REMAIN MOIST AND NEARLY SATURATED...WHICH WILL PROMOTE CONTINUED MOSTLY CLOUDY SKIES WITH JUST A SLOW WARMING TREND INTO THE WEEKEND. SOUTHERLY WINDS INCREASE SATURDAY AHEAD OF A STRONG UPPER LEVEL TROUGH THAT WILL MOVE INTO THE FOUR CORNERS REGION. WHILE MODEL GUIDANCE CONTINUES TO SHOW AN UPPER LEVEL LOW CLOSING OFF AT THE BASE OF THE TROUGH...THEY HAVE SHIFTED THE TRACK FARTHER TO THE NORTH THAN YESTERDAY/S MODEL RUNS. STILL...THE TRACK OF THIS SYSTEM WOULD PLACE NORTH TEXAS IN A REGION OF STRONG DYNAMIC LIFT AND GIVEN THE AMPLE LOW LEVEL MOISTURE ALREADY IN PLACE THIS SHOULD RESULT IN A GOOD CHANCE OF WIDESPREAD RAIN SUNDAY AND/OR SUNDAY NIGHT. WHILE SHEAR PROFILES ARE STRONG...SURFACE INSTABILITY LOOKS TO BE VERY LIMITED AND SHOULD LIMIT THE SEVERE WEATHER THREAT. 925MB THETA-E VALUES DO SUPPORT ENOUGH INSTABILITY FOR THE INCLUSION OF THUNDERSTORMS IN THE FORECAST BUT MUCAPE LOOKS TO BE LESS THAN 500 J/KG. RAIN CHANCES SHOULD END FROM WEST TO EAST SUNDAY NIGHT WITH THE PASSAGE OF A COLD FRONT. TEMPS WILL COOL BACK TO NEAR NORMAL FOR MONDAY...BUT WRAP-AROUND LOW CLOUDS MAY KEEP MONDAY/S HIGHS COOLER THAN CURRENTLY ADVERTISED. TR.92 && .AVIATION... /ISSUED 1148 PM CST MON DEC 8 2014/ CONCERNS...IFR/LIFR CONDITIONS LIKELY OVERNIGHT THROUGH 16Z AS AREAS OF FOG CONTINUE TO DEVELOP. MVFR CONDITIONS 16Z THROUGH 18-20Z. AREAS OF FOG DEVELOPED ACROSS NORTH AND CENTRAL TEXAS MONDAY EVENING. VISIBILITIES HAVE BEEN VARIABLE FALLING BELOW 1 MILE AT TIMES AND RISING TO 3-5SM. EXPECT VISIBILITIES OVERALL TO FALL TO 1 MILE OR LESS OVERNIGHT THROUGH MID MORNING TUESDAY AT THE TAF SITES...SO HAVE PLACED 1 SM BR IN MOST OF THE METROPLEX SITES...WITH A TEMPO 1/2SM 10-14Z. VISIBILITIES WILL LIKELY FALL TO 1/4 MILE OR LESS AT TIMES BUT FOR NOW WILL JUST LEAVE THE TEMPO 1/2SM. THE ONE INHIBITING FACTOR FOR DENSE FOG IS THE SHIELD OF HIGH CLOUDS THAT WILL BE MOVING ACROSS THE REGION THROUGH TUESDAY. EXPECT THE FOG TO DIMINISH BY LATE TUESDAY MORNING AND VFR CONDITIONS ARE EXPECTED TO RETURN EARLY TUESDAY AFTERNOON. WINDS WILL REMAIN LIGHT...MOSTLY NORTH TONIGHT AND NORTHEAST BY TUESDAY AFTERNOON. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 58 44 61 51 59 / 0 5 10 20 20 WACO, TX 62 42 60 51 63 / 0 5 20 30 30 PARIS, TX 60 39 55 43 55 / 0 5 5 20 20 DENTON, TX 57 40 60 49 58 / 0 5 10 20 20 MCKINNEY, TX 58 39 59 48 58 / 0 5 10 20 20 DALLAS, TX 59 45 60 50 60 / 0 5 10 20 20 TERRELL, TX 60 42 60 48 59 / 0 5 10 20 20 CORSICANA, TX 61 44 62 50 59 / 0 5 10 30 30 TEMPLE, TX 64 45 62 52 64 / 0 5 20 30 30 MINERAL WELLS, TX 61 42 59 51 62 / 0 5 10 20 20 && .FWD WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR TXZ091>095- 100>107-115>123-129>135-141>148-156>162-174-175. && $$ /
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1135 PM CST MON DEC 8 2014 .AVIATION... /06Z TAFS/ The aviation forecast remains problematic with regard to how extensive the low stratus and fog development will be overnight and early Tuesday morning in our forecast area. Goes 11-3.9 micron satellite imagery, along with confirmation calls to county law enforcement, indicates dense fog across the far northern part of our area (Haskell and Throckmorton Counties). Temperature/ dewpoint spreads are decreasing farther south across our area with radiational cooling, but thicker higher cloud coverage is also overspreading our area from the west. The increasing high cloudiness could delay and limit the development of fog and low stratus overnight. At this time, have higher confidence that the KABI site will be affected, and have conditions degrading to low end IFR conditions at that site after 08Z. Elswehere, leaning toward a patchy fog/low stratus scenario with MVFR visibilities. We will continue to monitor and make adjustments as needed. On Tuesday morning, any lingering low stratus/fog is expected to break up/dissipate around mid-morning with VFR conditions during the afternoon. Light winds overnight and early Tuesday morning will become southeast at 4-7 kt on Tuesday afternoon. 19 && .PREV DISCUSSION... /ISSUED 544 PM CST MON DEC 8 2014/ AVIATION... /00Z TAFS/ Continuing along the lines of the previous TAF package, regarding uncertainty with the extent of low stratus and fog development tonight. The latest NAM12 and RUC13 indicate that fog and low stratus may initially develop across our northeastern counties early tonight, then develop (in a patchy nature) farther south and west through the overnight hours. Could have IFR to LIFR visibilities and ceilings at times, but with the uncertainty at this time, going with a conservative approach with visibility reductions, and by carrying scattered low cloud layers as opposed to ceilings. Will monitor conditions throughout the evening and tonight and will make adjustments as needed. Light winds will continue tonight, and should eventually become southeast at 4-7 kt on Tuesday afternoon. PREV DISCUSSION... /ISSUED 325 PM CST Mon Dec 8 2014/ SHORT TERM... (Tonight and Tuesday) Skies have cleared across West Central Texas, allowing temperatures to warm into the mid 60s to near 70 degrees this afternoon. Winds remain light and variable across the region given the proximity to the surface anticyclone. This surface high will remain in place overnight but should shift far enough east to allow a return of weak southerly winds. With little change in the airmass and light winds in place across the area, fog and low stratus is expected to develop again tonight. This fog should remain patchy, and confidence is rather low regarding what areas will actually see the most significant reduced visibilities. Over the last two mornings, we have seen transient dense fog develop in various locations, with visibilities down to near zero at times. Fog is expected to lift in areas where low clouds develop. Otherwise, expect low temperatures in the lower 40s, possibly warming a few degrees if/when cloud cover develops. The fly in the ointment is the anticipated increase in high clouds. This could mitigate fog development. Pleasant weather conditions are anticipated on Tuesday. High clouds will continue to increase with southerly winds of 5 to 10 mph. No precipitation is expected throughout the day with temperatures warming into the mid and upper 60s. Johnson LONG TERM... (Tuesday night through Monday) As a weak upper ridge moves east of the area Tuesday night, a weak upper short wave will move east over New Mexico giving the forecast area our next chance of rainfall. The rainfall is expected to be light and will expand eastward from the southwestern CWA Tuesday night over the remaining CWA Wednesday through Thursday. The chance of rainfall will end on Friday as upper ridging builds over the area from the west in the wake of the departing upper short wave. Highs on Wednesday will be in the lower 60s warming into the Upper 60s to the lower 70s by Saturday. Models are closing an upper low over southern New Mexico Saturday night with the dryline tightening just west of the forecast area. Forcing along the Pacific front/dryline Saturday night will bring a chance of showers and thunderstorms over our western CWA Saturday night, expanding through the remainder of the forecast area through Sunday night. As the upper level system tracks east, an associated cold front will move across the forecast area on Sunday with cooler post-frontal highs on Monday ranging from the upper 40s to the lower 50s. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 41 66 48 62 51 / 0 0 5 20 20 San Angelo 41 67 49 62 52 / 0 0 10 30 20 Junction 39 67 47 61 51 / 0 0 10 40 40 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1112 PM CST MON DEC 8 2014 .UPDATE... AS EXPECTED...THE DENSE FOG HAS MOVED INTO THE FAR SOUTHEAST ZONES...AS CONFIRMED BY A CALL TO ASPERMONT. THE FOG PROBABLY IS NOT INTO COTTLE COUNTY JUST YET...BUT IT SHOULD EXPAND NORTH AND WESTWARD INTO COTTLE COUNTY OVER THE NEXT FEW HOURS. GIVEN THIS WE HAVE DECIDED TO ISSUE A DENSE FOG ADVISORY FOR COTTLE...KING AND STONEWALL COUNTIES THROUGH 10 AM TUESDAY. NO OTHER CHANGES HAVE BEEN MADE TO THE FORECAST ATTM. && .PREV DISCUSSION... /ISSUED 935 PM CST MON DEC 8 2014/ UPDATE... MINOR UPDATE TO ADJUST TEMPERATURES...DEWPOINT AND RH GRIDS SLIGHTLY TO BETTER ACCOUNT FOR RECENT OBSERVATIONS AND TRENDS. WE DID ALSO A MENTION OF DENSE FOG OVER THE EASTERN ROLLING PLAINS BEFORE 06Z...WITH A MORE WIDESPREAD FOG MENTION THEREAFTER. LATEST SATELLITE IMAGERY SHOWS AN EXPANDING AREA OF LOW CLOUDS AND FOG EXTENDING FROM THE FAR EASTERN FRINGES OF THE SOUTHEASTERN CWA INTO WESTERN NORTH TEXAS. KSPS HAS ALREADY REPORTED VISIBILITIES DOWN TO 1/4 MILE IN FOG...AND WITH TEMPERATURES APPROACHING THE DEWPOINT IN THE EASTERN ROLLING PLAINS...WE COULD SEE DENSE FOG MATERIALIZE HERE TOO OVER THE NEXT FEW HOURS. ADDITIONALLY...THOUGH PERHAPS LESS WIDESPREAD...FOG MAY BE POSSIBLE UP ON THE CAPROCK LATER TONIGHT /WELL AFTER MIDNIGHT/. WE WILL CONTINUE TO MONITOR THE PROGRESS OF THE FOG AND A DENSE FOG ADVISORY MAY BE NEEDED FOR PARTS OF THE CWA LATER TONIGHT. PREV DISCUSSION... /ISSUED 523 PM CST MON DEC 8 2014/ AVIATION... THIN BUT RICH LOW LEVEL MOISTURE IN PLACE TO THE SOUTHEAST OF KLBB AND SOUTH OF KCDS COULD BRING A PERIOD OF IFR CONDITIONS TO THE TERMINALS TONIGHT. 18Z WRF-NAM NOT AS PESSIMISTIC AS ITS 12Z RUN WHILE THE HRRR CONTINUES TO KEEP BEST POTENTIAL OFF THE CAPROCK AT KCDS. ALSO SOME QUESTION OF HOW MUCH HIGH CLOUDS MIGHT AFFECT COOLING AND THUS NARROWING OF TEMP-DEW SPREAD. WILL NOT MAKE MUCH IN THE WAY OF CHANGE ATTM WITH EXPECTATION THAT RESTRICTIONS TO VSBY AND/OR CIGS WILL BE NEAR OR AFTER 06Z. HOPEFULLY 00Z MODEL RUNS AND LATER HI-RES RUNS WILL ADD CLARITY. PREV DISCUSSION... /ISSUED 332 PM CST MON DEC 8 2014/ SHORT TERM... RIDGING WILL PERSIST ACROSS OUR AREA OVER THE NEXT 24 HOURS WITH VERY LITTLE...FROM A SYNOPTIC PERSPECTIVE...TO MAKE MUCH DIFFERENCE IN SENSIBLE WEATHER. SOUTHERLY FLOW WILL PERSIST ALTHOUGH WE WILL SEE A MORE SOUTHWESTERLY COMPONENTS ESPECIALLY WEST OF THE ESCARPMENT. THAT SAID...SPEEDS SHOULD BE QUITE LIGHT AND POTENTIAL FOR FOG WILL EXIST AREA WIDE. HOWEVER...THE MOST LIKELY LOCATION FOR DENSE FOG WILL BE ACROSS THE ROLLING PLAINS. YET...GIVEN THE INCREASING HIGH LEVEL CLOUDINESS APPARENT TO OUR WEST...EVEN THAT IS NOT GUARANTEED. SO...WILL STICK WITH MENTION OF FOG /PATCHY WEST TO AREAS EAST/ TONIGHT AND ALLOW THE OVERNIGHT SHIFTS TO ASSESS THE POTENTIAL FOR LOW VISIBILITIES. TEMPERATURES SHOULD REMAIN WITHIN A FEW DEGREES OF WHAT WE SAW DURING THE PREVIOUS 24 HOURS. LONG TERM... MENTIONABLE POPS HAVE BEEN REMOVED FOR WEDNESDAY THROUGH THURSDAY AS CHANCES LOOK TO BE MORE UNLIKELY. WHILE THERE WILL BE AMPLE MOISTURE AT THE LOW AND UPPER LEVELS...DRY AIR ASSOCIATED WITH SUBSIDENCE BETWEEN 800 AND 600 MB WILL PREVENT WHAT LITTLE PRECIP THAT MAY OCCUR FROM REACHING THE SURFACE. IN ADDITION TO DRY AIR...LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE WILL BE WEAK AT BEST. DESPITE A LACK OF PRECIP LOW LEVEL STRATUS WILL BE IN PLACE THROUGH WEDNESDAY INTO LATE THURSDAY MORNING. ALONG WITH STRATUS FOG WILL POSSIBLE ACROSS MUCH OF THE FA BOTH WEDNESDAY AND THURSDAY MORNING. FOG HAS BEEN LEFT OUT OF THE GRIDS FOR FRIDAY MORNING AS WINDS ARE EXPECTED TO TURN TO THE SOUTHWEST AS A LEE TROF APPROACHES THE AREA WHICH SHOULD HELP KEEP SURFACE RH VALUES LOWER. STRATUS SHOULD ALSO NOT BE AN ISSUE FRIDAY MORNING WITH MOSTLY DRY AIR WILL BE SITTING OVER THE REGION. BY FRIDAY AFTERNOON AN ELONGATED TROF WILL BE POSITIONED OVER THE PACIFIC COAST WITH THE LEE TROF DIGGING FURTHER SOUTHWARD. CONTINUOUS SURFACE WINDS OUT OF THE SOUTHWEST WILL HELP WARM TEMPS TO NEAR 70 ON FRIDAY AND SATURDAY. THE UPPER LEVEL TROF SHOULD BE NEAR THE FOOTHILLS OF THE ROCKIES BY LATE SATURDAY AND SHOULD BEGIN TO ELONGATE FURTHER SOUTHWARD. THE GFS HAS BEEN FAIRLY CONSISTENT WITH PINCHING OFF THE LOWER HALF OF THE TROF MAKING A CLOSED LOW WHICH WOULD GIVE THE REGION A DECENT SHOT AT PRECIP. UNTIL THE MORE RECENT 12Z RUN THE ECMWF SHOWED A SIMILAR BUT SLOWER SOLUTION. THE 12Z ECMWF KEEPS THE LOW CLOSED OFF ALONG THE US/CA BORDER WITH AN OPEN TROF IN THE SOUTH-CENTRAL CONUS. THOUGH THE TROF REMAINS OPEN IT MATCHES THE SPEED OF THE GFS ALMOST PERFECTLY. FOR NOW PRECIP CHANCES HAVE BEEN KEPT IN THE FORECAST STARTING LATE SATURDAY WITH HIGH POPS EXISTING OVER THE ROLLING PLAINS. THE BIGGER CHALLENGE COMES WITH PRECIP TYPE LATE SUNDAY AFTER A COLD FRONT PUSHES INTO THE REGION PENDING THAT THE LOW IS CLOSED. BOTH MODELS SHOW 850 MB TEMPS REMAIN ABOVE FREEZING BUT NOT BY MUCH. THE 00Z RUN OF THE ECMWF SHOWED 850 MB TEMPS DOWN TO -5C. SNOW WOULD NOT BE OUT OF THE REALM OF POSSIBILITY IF TEMPS CAN COOL DOWN FAST ENOUGH...BUT FOR NOW THE MENTION WILL BE FOR RAIN OR SNOW. REGARDLESS OF PRECIP TEMPERATURES SHOULD BE NOTICEABLY COLDER BEHIND THE FRONT WITH HIGHS AVERAGING IN THE MID 40S ON MONDAY WITH LOWS DIPPING BACK DOWN BELOW FREEZING FOR MUCH OF THE AREA. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 35 61 41 60 38 / 0 0 10 10 10 TULIA 35 61 42 59 42 / 0 0 10 10 10 PLAINVIEW 35 61 43 59 41 / 0 0 10 10 10 LEVELLAND 38 61 42 59 43 / 0 0 10 10 10 LUBBOCK 39 63 44 59 43 / 0 0 10 10 10 DENVER CITY 43 61 44 59 43 / 0 0 10 10 10 BROWNFIELD 40 61 44 59 45 / 0 0 10 10 10 CHILDRESS 39 66 43 62 47 / 0 0 10 10 10 SPUR 38 64 44 62 48 / 0 0 10 10 10 ASPERMONT 39 66 45 63 50 / 0 0 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING ZONES: TXZ032-038-044. && $$ 07/23
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
127 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE OFF THE COAST OF VIRGINIA WILL DEEPEN AS IT SHIFTS UP TOWARD THE JERSEY COAST BY TUESDAY AFTERNOON. A TROUGH OF LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES REGION AND MERGE WITH THE COASTAL LOW BY TUESDAY NIGHT OVER NEW ENGLAND. ONCE THIS HAPPENS OUR AREA WILL STAY IN A NORTHWEST FLOW THROUGH THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 110 AM EST TUESDAY... RADAR SHOWING EDGE OF SOLID PRECIP ALONG/EAST OF THE BLUE RIDGE FROM PATRICK COUNTY VA NORTH INTO THE SOUTHERN SHENANDOAH VALLEY...WITH JUST SCATTERED POCKETS OF PRECIP WEST. WITH THE SW CWA CLEARING OF PRECIP CANCELLED THE WINTER WX ADVISORY FROM PULASKI AND WYTHE SOUTH TO CARROLL AND GRAYSON. SOME PATCHY DRIZZLE/FREEZING DRIZZLE STILL POSSIBLE FOR ANOTHER FEW HOURS BUT OVERALL THREAT OF ICY ROADS IS TOO LOW TO HAVE AN ADVISORY. REST OF THE ADVISORY AREA WILL REMAIN IN EFFECT TIL 8 AM...THOUGH IF THINGS CLEAR OUT SOONER...A FEW MORE COUNTIES COULD BE CLEARED BY 4 AM. TEMPS ARE RUNNING GENERALLY JUST BELOW FREEZING ALONG AND WEST OF THE BLUE RIDGE TO THE UPPER 30S OUT EAST. THE 00Z NAM AND THE LATEST RAP WERE SHOWING MOST OF THE QPF STAYING TOWARD LYH AND NORTHEAST AS WE HEAD THROUGH THE MORNING. WHERE THE ADVISORY IS IN PLACE...ONLY LIGHT AMOUNTS ARE EXPECTED. PREVIOUS VALID DISCUSSION.... NEXT ROUND OF PRECIP IN THE WEST WILL HOLD OFF TIL AROUND OR AFTER DAYBREAK WHEN THE UPPER TROUGH PASSES AND THE UPSLOPE SNOW SHOWERS BEGIN. FOR TUESDAY...THE FLOW TURNS QUICKLY NORTHWEST BEHIND DEEPENING SURFACE CYCLONE AND INCREASING COLD ADVECTION...WITH SHOWERY PRECIPITATION IN FAVORED UPSLOPE AREAS OF OUR WESTERN CWA... ESPECIALLY LATE IN DAY. TEMPERATURES WILL STRUGGLE TO WARM TUESDAY PER INCREASING COLD AIR ADVECTION...BUT THINK WE MANAGE THE 40S MOST AREAS...WITH THE EXCEPTION OF THE MOUNTAINS WHERE CLOUDS AND DEVELOPING SHOWERY PRECIPITATION WILL PUT A DRAG ON THE THERMOMETER. BY THE END OF THE DAY...AN INCH OR TWO OF SNOW IS POSSIBLE IN NORTHWEST GREENBRIER COUNTY...AND ALONG THE WESTERN SLOPES INTO THE HIGH COUNTRY OF NC. ELSEWHERE...MAYBE SOME FLURRIES OR SPRINKLES BUT THATS ABOUT IT. BIGGEST DEVELOPMENT WILL BE THE INCREASE IN NORTHWESTERLY WINDS WHICH WILL BECOME BLUSTERY AS WE PROGRESS INTO TUESDAY NIGHT. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... AS OF 400 PM EST MONDAY... THE STRENGTHENING UPPER LOW IS PROGGED TO CROSS THE REGION TUESDAY EVENING. THIS WILL QUICKLY BRING AN END TO ANY WARM NOSE CONCERNS IN THE LOWER THERMAL PROFILE AS A COLD FRONT CROSSES THE REGION. BEHIND THE FRONT NORTHWEST WINDS WILL BECOME GUSTY AS THE PRESSURE GRADIENT TIGHTENS IN ASSOCIATION WITH THE DEVELOPING NOREASTER. THIS WILL BRING A PROLONGED PERIOD OF UPSLOPE RAIN/SNOW SHOWERS TO THE PREFERRED AREAS OF SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. THERE WILL BE SOME DOWNWIND ISOLATED TO SCATTERED ACTIVITY EAST TO NEAR THE CREST OF THE BLUE RIDGE. AS TIME PROGRESSES THROUGH THURSDAY...COVERAGE OF THE RAIN/SNOW SHOWERS WILL DECREASE AS PROGRESSIVELY DRIER AIR WORKS ITS WAY INTO THE REGION. SOME OF THE HIGHER WIND GUSTS WILL BE AT ELEVATIONS ABOVE 3000 FT MSL AND REACH THE 30 TO 40 MPH RANGE. SNOWFALL TOTALS DURING THIS PORTION OF THE FORECAST WILL BE GREATEST ACROSS WESTERN GREENBRIER COUNTY WV WITH A 1 TO 4 INCH RANGE. THE REMAINDER OF THE PREFERRED UPSLOPE REGION OF SOUTHEAST WEST VIRGINIA WILL MAINLY BE UNDER AN INCH. THE HIGHER TERRAIN OF WESTERN ASHE AND WATAUGA COUNTIES NC WILL EXPERIENCE AROUND ONE INCH DURING THIS TIME FRAME. OTHER SNOWFALL TOTALS WILL BE MAINLY A FEW TENTHS OVER PARTS OF THE MOUNTAIN EMPIRE REGION OF SOUTHWEST VIRGINIA AND OTHER PORTIONS OF ASHE AND WATAUGA COUNTY NC. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 400 PM EST MONDAY... MODELS ARE NOW IN THE SAME BALLPARK FOR THE EXTENDED...JUST NOT SURE IF THE GAME IS FOOTBALL OR SOCCER. EVOLUTION TO A HIGHLY AMPLIFIED UPPER PATTERN WITH DEVELOPMENT OF A CLOSED LOW DOING A SIT AND SPIN OVER THE NORTHEAST US IS A FAVORED SOLUTION THROUGH THE END OF THE WEEK. BEGIN TO SEE SIGNIFICANT DIFFERENCES AS WE HEAD INTO THE WEEKEND WITH GFS BEING TYPICALLY MORE PROGRESSIVE AND EURO DIGGING IN ITS HEELS. BY MONDAY UPPER RIDGE AXIS SHOULD BE CROSSING THE REGION AS NEXT SOUTHERN STREAM CLOSED LOW APPROACHES FROM THE LOWER MISSISSIPPI VALLEY. EVEN WITH THE MODEL DIFFERENCES...IMPACTS ON SENSIBLE WEATHER ELEMENTS THROUGH THE EXTENDED WILL BE SMALL. NW FLOW UPSLOPE SNOW SHOWERS ACROSS THE FAR WRN SLOPES OF THE BLUE RIDGE WILL BE WINDING DOWN THURSDAY NIGHT AS SFC HIGH SLIDES IN FROM THE WEST. MAYBE SOME FLURRIES FAR WRN SLOPES THROUGH THE END OF THE WEEK...BUT LOOKING LIKE QUIET WEATHER ELSEWHERE. WE THEN GET INTO SOME WEAK LIFT AS A LIGHT WARM AIR ADVECTION PATTERN SETS UP SATURDAY NIGHT THROUGH SUNDAY. THIS MAY BE ENOUGH TO GET SOME SPRINKLES GOING BUT NOTHING TOO EXCITING...AND GIVEN THE MODEL UNCERTAINTY THIS FAR OUT WILL GO WITH POPS NO HIGHER THAN SLIGHT CHC CONFINED TO WEST OF THE BLUE RIDGE. EXPECT A WARMING TREND FROM BELOW NORMAL FRIDAY TO ABOVE NORMAL BY THE START OF NEXT WEEK. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 1150 PM EST MONDAY... LOW PRESSURE DEVELOPING OFF THE SOUTHEAST WILL SLIDE UP THE MIDDLE ATLANTIC COAST AND PUSH MOISTURE INTO THE REGION AS IT GOES. SYSTEM WILL BE PULLING AWAY FROM THE REGION AS E HEAD TOWARD DAYBREAK AND THIS WILL ALLOW WINDS TO BACK AROUND TO THE NW. EXPECT WESTERN EDGE OF PRECIPITATION TO REACH KDAN/KROA/KLYH AROUND 10Z/5AM. UNTIL THEN HIGH CONFIDENCE OF LIFR CEILINGS. PROLONGED UPSLOPE PATTERN WEST OF THE BLUE RIDGE WITH LOWER CLOUDS AND SOME SHOWERY PRECIP...WITH DOWNSLOPE AND IMPROVEMENT EAST OF THE RIDGE WILL DEVELOP BY 18Z. AS THE COASTAL LOW DEEPENS...NW WINDS WILL BE ON THE INCREASE. LATEST GUIDANCE SUGGESTING MORE LIGHT PRECIPITATION MAY ROTATE AROUND THE LOW BACK INTO KLYH AND KDAN TUESDAY AFTERNOON. MODERATE CONFIDENCE WITH THIS SCENARIO. EXTENDED DISCUSSION... SNOW SHOWERS AND MVFR UPSLOPE CLOUDS WILL CONTINUE IN SOUTHEAST WEST VIRGINIA THROUGH THURSDAY MORNING. VFR CONDITIONS ARE EXPECTED IN THE EAST. GUSTY WINDS ARE LIKELY THROUGH WEDNESDAY NIGHT. THURSDAY NIGHT THROUGH SATURDAY...ASIDE FOR SOME LINGERING MVFR CLOUDINESS IN THE WV MOUNTAINS THURSDAY...HIGH PRESSURE WILL BUILD OVER THE MID ATLANTIC THURSDAY THROUGH SATURDAY WITH VFR AND DIMINISHING WINDS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 8 AM EST THIS MORNING FOR VAZ014- 017>020-022>024-032>035. NC...NONE. WV...NONE. && $$ SYNOPSIS...PM/WP NEAR TERM...AMS/PM/WP SHORT TERM...DS LONG TERM...MBS AVIATION...MBS/PM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1058 AM EST TUE DEC 9 2014 .SYNOPSIS... A SIGNIFICANT COASTAL STORM WILL IMPACT THE REGION TODAY WITH WINTRY PRECIPITATION AND HEAVY RAIN...ALONG WITH STRONG TO DAMAGING WINDS. LEFTOVER LIGHT SNOW AND RAIN SHOWERS WILL PERSIST WEDNESDAY AND THURSDAY. SLOW IMPROVEMENT IS EXPECTED FRI INTO THIS WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 1040 AM UPDATE... TEMPS HAVE BEEN SLOWLY BUT STEADILY RISING ACROSS E MA/RI/NE CT THROUGH 15Z...BUT HOLDING RIGHT AROUND FREEZING FROM THE INTERIOR MERRIMACK VALLEY THROUGH CENTRAL AND NW MA. NOTING THAT TEMPS HAVE BEEN WARMING ALOFT WITH RATHER STRONG LOW LEVEL INVERSION AS SEEN ON 12Z KOKX SOUNDING /UP TO +5C AT 866 MB AND FREEZING LEVEL UP TO 6500 FT/...SO TENDING TO MIX DOWN WITH THE AREA OF HEAVY RAINFALL MOVING INTO S COASTAL AREAS. THIS WILL HELP TEMPS RISE EVEN ACROSS INLAND AREAS AS THE SLUG OVER HEAVY PRECIP MOVES IN. NOTING 1005 HPA LOW PRES JUST NE OF THE DELMARVA PENINSULA AT 15Z...WHICH APPEARS PRETTY MUCH ON TRACK THOUGH TUCKED A BIT CLOSER TO THE COAST. NOTING REPORTS OF 0.75 TO 1 INCH/HR RAINFALL RATES ACROSS S CT AND LONG ISLAND OVER THE LAST HOUR OR TWO. THIS...ALONG WITH GUIDANCE FROM NESDIS SATELLITE PRECIP ESTIMATE REPORTING A MAX PWAT PLUME OF 1.65 INCHES WELL S OF LONG ISLAND EARLIER THIS MORNING. VERY COLD CLOUD TOPS ALSO NOTED S OF LONG ISLAND. DRY SLOT NOTED ON NE REGIONAL 88D RADAR E OF KACY...WHICH WILL SLOWLY SHIFT N-NE DURING THE DAY. ALSO NOTED 06Z GFS OP RUN SUGGESTING UP TO 1.5 TO 2 INCH RAINFALL RATES IN TWO 6-HOUR PERIODS BETWEEN NOW AND 00Z MOVING ACROSS RI/E MA. CONSIDERING THE NESDIS OBSERVATIONS...FELT THIS WAS NOT TOO BAD SO UPDATED TO INCREASE PRECIP AMOUNTS. THIS GIVES STORM TOTAL PRECIP OF 2.5 TO 3.5 INCHES...WHICH MAY LEAD TO LOCALIZED URBAN AND POOR DRAINAGE FLOODING ACROSS RI/E MA. HAVE UPDATED FORECAST TO INCLUDE HEAVY RAINFALL MENTION TO THE FORECAST. WILL ALSO MONITOR FOR THE CHANCE OF ANY THUNDER THAT MAY NEED TO BE ADDED ACROSS S COASTAL RI/MA. NOTING C/G LIGHTNING TO THE E OF THE DRY SLOT. ALSO UPDATED TEMPS/DEWPTS TO BRING CONDITIONS CURRENT. REMAINDER OF FORECAST IN PRETTY GOOD SHAPE. PREVIOUS DISCUSSION... * SYNOPTICALLY... PRESENT OFFSHORE LOW OFF THE MID-ATLANTIC CONUS BECOMES USURPED BY AN AMPLIFYING TROUGH DIGGING THROUGH THE E-CONUS. ACROSS A REGION OF FAVORABLE BAROCLINICITY / ATTENDANT DYNAMICS / STRONG FORCING AND DEEP-LAYER ASCENT YIELDS A RAPIDLY DEEPENING AREA OF LOW PRESSURE OFF THE DELMARVA PENINSULA THIS MORNING LIFTING N INTO S NEW ENGLAND BY EVENING. THE LOW BECOMES STALLED AND CUTOFF FROM THE MEAN FLOW UP AGAINST HIGH PRESSURE ON NEARLY ALL SIDES AS WE GO INTO THE WEEK. * HEAVY RAIN AND FLOODING... AS THE LOW DEEPENS...EXPECT DECENT LOW-LEVEL TROWALING OF THE WARM-CONVEYER-BELT BENEATH THE RRQ/LFQ OF ATTENDANT UPPER-LEVEL JET AXES. COMBINATION OF THE CONVERGENT LEADING NOSE OF ISENTROPIC UPSLOPE LENDING TO THE TIGHTENING OF THE THERMAL GRADIENT AGAINST NEIGHBORING HIGH PRESSURE YIELDING STRONG FRONTOGENETICAL FORCING IN A REGION OF MINOR -EPV INSTABILITY BENEATH AFOREMENTIONED DEEP LAYER ASCENT LIKELY TO RESULT IN A ROUGHLY W-E BANDING SETUP OF HIGHER WSR-88D RETURNS WITHIN A WIDESPREAD COMMA-SHAPED PRECIP FIELD ALONG THE N-PERIPHERY OF THE H85 LOW WITH THE FRONT-END THUMP OF PRECIP ANTICIPATED AROUND MIDDAY AND PERSISTING INTO EARLY EVENING. WILL EXPAND THE FLOOD WATCH TO INCLUDE CAPE COD AND NANTUCKET. WITH HEIGHT OF THE E-NE WINDS AND HEAVY RAIN CONCURRENT WITH TIMING OF HIGH TIDE CENTERED AROUND 1 PM BELIEVE SURGE ALONG WITH BUILDING WAVE HEIGHTS /SEE THE MARINE DISCUSSION BELOW FOR MORE DETAILS/ WILL RESULT IN POOR-DRAINAGE ISSUES FOR COASTAL COMMUNITIES. ANTICIPATE DRAINS TO BACK-UP BECOMING OVER-TOPPED RESULTING IN SUSCEPTIBLE LOW- LYING AND POOR-DRAINAGE AREAS TO BECOME FLOODED. AM ALSO CONCERNED FOR EVEN THOSE COMMUNITIES WITHIN THE COASTAL PLAIN IN VICINITY OF RIVERS THAT ARE INFLUENCED BY THE TIDE /I.E. TAUNTON RIVER...LOWER CONNECTICUT/. COULD ALSO SEE SOME EXACERBATED FLOOD ISSUES FOR THESE AREAS. OTHERWISE REMAINDER OF THE FLOOD WATCH REMAINS IN PLACE. PWATS OF 1.25-INCHES FORECAST /ROUGHLY +2 STANDARD DEVIATIONS ABOVE-NORMAL/ AND FORECAST RAINFALL AMOUNTS OF 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS ANTICIPATED. GROUND IS PRETTY SOLID /IMPERVIOUS/ THUS EXPECT MOST OF THE RAINFALL TO BECOME RUNOFF. MAJORITY OF MAINSTEM RIVERS OVER THE INTERIOR SHOULD BE ABLE TO HANDLE THE RAIN...SO CONCERNS LIE IN THE REALM OF URBAN / POOR DRAINAGE FLOODING...ESPECIALLY IF DRAINS ARE STILL LEAF-CLOGGED. BIGGEST AREA OF CONCERN IS WITHIN THE METRO-AREA CORRIDORS...ESPECIALLY BOSTON-PROVIDENCE. MAY NEED TO EXPAND THE WATCH ACROSS N-CENTRAL AND NW MA PENDING THE TIMING AT WHICH WINTRY-PRECIP TYPES TRANSITION TO RAIN. * WINTRY PRECIPITATION... OUTCOMES DEPENDENT ON THERMAL FIELDS ALOFT...WHERE AROUND H925-H85 BY MORNING CONDITIONS ARE WARMING CONSIDERABLY UP AGAINST COLDER AIR AND HIGH PRESSURE SITUATED N/W. A SW-NE FREEZING LINE AROUND NW-CT INTO S NH INITIALLY MODIFIES NW AS THE LOW DEEPENS RESULTING IN THE INCREASE OF THE SE WARM-MOIST-CONVEYER-BELT. EXPECT THICKNESSES TO GRADUALLY RISE DURING THE HEIGHT OF THE EVENT INTO EVENING. AT THE SURFACE...AREAS BELOW FREEZING ERODE WITH INCREASING ONSHORE E/NE-WINDS DURING THE MORNING /MORE ON THAT LATER/. UNCERTAINTY CONTINUES WITH 09.0Z HIGH-RES MODELS DIFFERING IN TIMING OF EROSION. AS MENTIONED IN PRIOR DISCUSSIONS...FOR AREAS THAT ARE WITHIN OR ON THE CUSP OF BELOW-FREEZING TEMPERATURES BY 1-2C...LINGERING AN HOUR OR TWO MORE OR LESS CAN MAKE ALL THE DIFFERENCE WITH REGARDS TO WINTER-WEATHER HEAD-LINES. H975-925 AGEOSTROPHIC FLOW IS NOTABLY PERSISTENT AND STRONG OUT OF THE W AS THE LOW INTENSIFIES TOWARDS S NEW ENGLAND. BUT NOT MUCH OF A N-COMPONENT NOR FROM ARCTIC-SOURCE REGIONS...SO BELIEVE THIS WILL DO LITTLE TO MAINTAIN / PERSIST COLD AIR OVER THE REGION AGAINST STRONG ONSHORE E-FLOW. WILL GO CLOSE TO THE NEAR-TERM HIGH-RES GUIDANCE WHILE INCORPORATING THE WRF-NMM WITH REGARDS TO THERMAL FIELDS...WHICH ARE HANDLING THE SURFACE TEMPERATURES DECENTLY. PREFERENCE TO THE 09.0Z ECMWF IS ALSO GIVEN ESPECIALLY WHEN EVALUATING H100-H85 THICKNESSES. ONLY WRF-ARW AND RAP LEAN ON THE WARM SIDE OF THE GUIDANCE OVER ALL OTHERS. ALSO WILL GO WITH A TOP-DOWN APPROACH TOWARDS PRECIPITATION-TYPE THAT INCORPORATES THE INCREASING MOISTURE FROM THE S WITHIN OR ABOVE THE DENDRITIC GROWTH ZONE REGION. SO OVERALL...EXPECTING THE GRADUAL EROSION OF THE COASTAL-FRONT WITH INCREASING ONSHORE E-FLOW. PUSH OF WARMER AIR ALOFT AHEAD OF THE DEEPENING LOW WILL RESULT IN PRECIP-TYPE TRANSITION FAIRLY QUICKLY TO A SLEET / FREEZING RAIN MIX. THIS HAS SUBSEQUENTLY BUMPED DOWN SNOWFALL AMOUNTS RESULTING IN A RANGE OF 2-4 INCHES ACROSS NW MA. MOST OF THE REGION CHANGES OVER TO RAIN BY LATE MORNING INTO MIDDAY WITH ONLY THE HIGHER ELEVATIONS OF THE BERKSHIRES CONTINUALLY UNDER THE THREAT OF FREEZING RAIN. HAVE DROPPED WINTER-STORM WATCHES AND REPLACED WITH WINTER WEATHER ADVISORIES. HAVE TRIMMED THE EASTERN-EXTENT WITH EROSION OF THE COASTAL FRONT AND THE SURGE OF WARMER AIR ONSHORE. AGAIN...THE THERMAL FIELDS DISCUSSION ABOVE GIVE AN INDICATION OF PREFERRED MODEL GUIDANCE. SHOULD SEE WINTER WEATHER HEADLINES DROP MAINLY AROUND THE MIDDAY HOURS. MID-LEVEL DRY-SLOT WRAPPING INTO A DEVELOPING OCCLUSION BEGINNING TUESDAY EVENING SHOULD RESULT IN A LULL OF PRECIPITATION AS WE GO INTO WEDNESDAY MORNING. * STRONG TO DAMAGING WINDS... NOTING E-WINDS 1-2 KFT AGL WILL BE AROUND 55 MPH AROUND THE MIDDAY INTO AFTERNOON HOURS...THE PRESENCE OF WARMER AIR ALOFT LENDING TO AN INVERSION JUST ABOVE THE SURFACE MAKES IT DIFFICULT TO CONSIDER A HIGH WIND WARNING. THIS DESPITE WARMER AIR WIGGLING ITS WAY UP FROM THE S AT THE SURFACE...AND A WARMER OCEAN /THOUGH NOW AROUND THE LOW- 50S/. BOUNDARY-LAYER MIXING WILL BE LIMITED. HIGH-END WIND ADVISORY CRITERIA IS EXPECTED...BUT DO NOT EXPECT WIDESPREAD GUSTS EXCEEDING HIGH WIND WARNING CRITERIA. THUS WENT WITH THE WIND ADVISORY. COULD PRECIPITATION-DRAG PROCESSES BRING FASTER MOMENTUM TO THE SURFACE? YES...IT IS QUITE POSSIBLE...EVEN IF THUNDERSTORMS ARE IN THE MIX WHICH IS IN THE FORECAST FOR THE FAR SE-WATERS ADJACENT TO THE CAPE AND ISLANDS. HAVE GONE WITH THE HEADLINES THAT CONVEY THE HIGHEST CONFIDENCE. * COASTAL FLOODING... SEE TIDES/COASTAL FLOODING SECTION BELOW FOR DETAILS. && .SHORT TERM /WEDNESDAY/... SEE LONG TERM SECTION BELOW. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... HIGHLIGHTS... * LINGERING RAIN/SNOW SHOWERS INTO THU AS CLOSED LOW SLOWLY EXITS * IMPROVING CONDITIONS FRI INTO THIS WEEKEND DECENT MODEL AGREEMENT BOTH AT THE SURFACE AND ALOFT WEDNESDAY INTO FRIDAY. MORE SIGNIFICANT DIFFERENCES ARISE FRIDAY NIGHT INTO EARLY NEXT WEEK. AS SUCH...FAVORED A CONSENSUS BLEND TO UPDATE THIS PORTION OF THE FORECAST. THIS WAS TO SMOOTH OVER THE MINOR DIFFERENCES INTO FRIDAY...AS WELL AS MINIMIZE ERROR AFTER THAT POINT. CLOSED LOW WILL BE SLOW TO EXIT NEW ENGLAND...AND 09/00Z GUIDANCE MODELS CONTINUE TO SHOW A DEEP UPPER LOW OVER NORTHERN NEW ENGLAND FINALLY MOVING OUT TO SEA SATURDAY NIGHT. ONE OF THE PRIMARY ISSUES WITH THIS FORECAST WILL BE THE AMOUNT OF MOISTURE AVAILABLE. THINKING THERE WILL BE ENOUGH TO KEEP SKIES MOSTLY CLOUD INTO FRIDAY NIGHT. HOW MUCH WILL BE LEFTOVER TO US IN GENERATING PRECIPITATION IS ANOTHER MATTER. CONTINUED THE PREVIOUS FORECAST OF A GRADUAL DRYING OUT PROCESS FRIDAY INTO SATURDAY. HIGH PRESSURE SHOULD BE IN CONTROL OF OUR WEATHER SUNDAY INTO MONDAY. NEAR OR SLIGHTLY BELOW NORMAL TEMPERATURES EXPECTED THROUGH THIS PERIOD. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY MORNING/... 12Z UPDATE... TODAY INTO TONIGHT...MODERATE CONFIDENCE. MIX OF MVFR-IFR CIGS / VSBYS WITH MAINLY +RA. AN ISOLATED TSRA IS POSSIBLE FOR FAR SE-COASTAL TERMINALS. OTHERWISE GRADUAL EROSION TO N/W OF FZRA/PL/SN INTO THE EARLY-AFTERNOON HOURS DURING WHICH TIME WINDS WILL INCREASE OUT OF THE E WITH STRONGEST GUSTS ALONG THE E-SHORELINE MAINLY AROUND 40 KT WITH LOCALLY HIGHER GUSTS UP TO 50 KT. WILL ALSO SEE AN ACCOMPANYING LLWS THREAT WITH WINDS AROUND 2 KFT AGL OUT OF THE E AROUND 60 KTS. KBOS TERMINAL...MODERATE CONFIDENCE. FEEL CONFIDENT WITH TRENDS BUT NOT SO MUCH WITH SPECIFICS. HIGH CONFIDENCE OF CONTINUED +RA WITH INCREASING E-WINDS. GUSTS UP TO 40 KT ANTICIPATED TOWARDS THE MIDDAY HRS. WIND ADVISORY LENDING TO ISSUANCE OF AIRPORT WEATHER WARNING. KBDL TERMINAL...MODERATE CONFIDENCE. FZRA PERSISTING INTO THE EARLY-MORNING HOURS...THEN CHANGING OVER TO RAIN. NOT ABSOLUTELY CERTAIN ON TIMING BUT CONFIDENT WITH TRENDS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. MVFR/IFR IN SCATTERED RAIN OR SNOW SHOWERS. FRIDAY...MODERATE CONFIDENCE. MVFR IN ISOLATED RAIN/SNOW SHOWERS. SATURDAY...MODERATE CONFIDENCE. VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE. 1030 AM UPDATE... THROUGH THIS AFTERNOON NOTING SEAS HAVE INCREASED TO 10-15 FT ON THE OUTER WATERS AND EVEN PUSHING INTO MASS BAY ON THE E FETCH. HAVE UPDATED TO INCREASE THE SEAS TO AT LEAST THESE LEVELS. EXPECT STRONGEST WINDS TO PUSH INTO THE WATERS. GUSTS UP TO 33 KT REPORTS AT BUOY 44020 /NANTUCKET SOUND/ AND 31 KT AT BOTH MASS BAY BUOYS WITH 35 KT GUSTS AT THE BUZZARDS BAY TOWER AT 15Z. FORECAST THROUGH TODAY PRETTY MUCH ON TRACK. PREVIOUS DISCUSSION... HAVE GONE WITH STORM WARNINGS FOR THE OUTER WATERS WITH THE EXPECTATION OF GUSTS AROUND 45-50 KT. BUT GREATER CONFIDENCE OF THE INNER WATERS REACHING HIGH-END GALE WARNING CRITERIA PERMITTED THE DISCONTINUING OF THE STORM WATCH. CAN NOT RULE OUT AN ISOLATED GUST UP TO 50 KTS OVER THE INNER WATERS...BUT WITH IT NOT ANTICIPATED TO BE WIDESPREAD...KEPT WITH GALE WARNINGS. STRONGEST E-WINDS OCCURRING TOWARDS THE MIDDAY AND CONTINUING INTO THE EARLY EVENING HOURS. SEAS BUILDING 15 TO 20 FEET WITH INCREASING E WINDS AHEAD OF A DEEPENING AREA OF LOW PRESSURE OF THE DELMARVA PENINSULA PRESENTLY AS IT LIFTS N INTO S NEW ENGLAND TOWARDS THIS EVENING. EXPECT ACCOMPANYING HEAVY RAIN WHICH WILL YIELD VISIBILITY RESTRICTIONS ON THE WATERS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. SMALL CRAFT ADVISORIES WILL LIKELY NEED TO CONTINUE THROUGH THURSDAY NIGHT ACROSS THE OCEAN-EXPOSED COASTAL WATERS...MAINLY DUE TO ROUGH SEAS. THERE COULD ALSO BE SOME WEST/SOUTHWEST GUSTS UP TO 25 KT AS WELL. ALSO SHOULD SEE LEFTOVER SCATTERED RAIN/SNOW SHOWERS. FRIDAY INTO SATURDAY...MODERATE CONFIDENCE. SLOW IMPROVEMENT CONTINUES WITH DIMINISHING WINDS AND SEAS. SEAS SHOULD FINALLY DROP BELOW 5 FT ACROSS ALL BUT THE OUTERMOST COASTAL WATERS FRI EVENING...THEN REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS ACROSS ALL WATERS SATURDAY. && .HYDROLOGY... UPDATED 950 AM TUE... EXPANDED FLOOD WATCH TO INCLUDE MARTHAS VINEYARD AND BLOCK ISLAND. ALTHOUGH RAINFALL TOTALS WILL BE 1.5 TO 2.5 INCHES...COMBINATION OF RAINFALL AND RISING TIDE THROUGH EARLY AFTERNOON MAY LEAD TO SIGNIFICANT FLOODING ESPECIALLY ON E/SE SHORELINES. BUOYS REPORTING 5-6 FT SEAS ON NANTUCKET SOUND AND 11 FT SE OF BLOCK ISLAND. SIMILAR SITUATION FOR CAPE COD AND NANTUCKET. MAIN CONCERN CONTINUES TO BE POTENTIAL FOR SIGNIFICANT URBAN FLOODING...ESPECIALLY IN RI AND E MA. ALREADY SEEING RAINFALL RATES OF NEARLY 2 INCHES PER HOUR ACROSS SOUTHERN CT /KSNC ASOS/ WHICH WILL TRANSLATE OVER OUR AREA BY EARLY AFTERNOON. SOME OF THE URBAN HOT SPOTS SUCH AS PEABODY...FALL RIVER...NEW BEDFORD AND CRANSTON MAY BE ESPECIALLY VULNERABLE TO FLOODING. TOTALS OF 2 TO 3 INCHES ARE EXPECTED WITH A FEW 3 OR 4 INCH TOTALS NOT OUT OF QUESTION NEAR I-95 CORRIDOR. FLOODING OF SMALL STREAMS IS ALSO A POSSIBILITY...BUT WORST CASE WOULD BE FOR MINOR FLOODING IF TOTALS EXCEED 3 INCHES. NOT EXPECTING FLOODING OF LARGER RIVERS. LATEST NERFC GUIDANCE BRINGS LOWER CT RIVER AT MIDDLE HADDAM TO ACTION STAGE...WHICH IS PRIMARILY BASED ON SURGE OF 2 FT INTO LOWER CT RIVER. WE MAY ALSO SEE SIMILAR SURGE ALONG PAWCATUCK RIVER NEAR WESTERLY RI WHICH COULD BRING RISES SLIGHTLY HIGHER THAN CURRENTLY FORECAST. && .TIDES/COASTAL FLOODING... COASTAL FLOOD ADVISORY CONTINUES FOR EASTERN MA. COMBINATION OF WINDS / SEAS / SURGE OF AROUND 1.5 TO 2 FEET DURING THE MIDDAY HIGH-TIDE YIELDS THE LIKELIHOOD OF OBSERVING MINOR COASTAL FLOODING AND BEACH EROSION FOR E-FACING SHORELINES WHERE SEAS OF 12 TO 15 FEET ARE POSSIBLE. AS NOTED IN THE HYDROLOGY PORTION ABOVE...LOCAL STREAMS AND TRIBUTARIES EMPTYING INTO THE SEA COULD SEE BACK-FILLING ISSUES AS THE HEAVY RAIN IS ANTICIPATED DURING THE TIME OF HIGH-TIDE. COULD SEE FLOODING ISSUES EXACERBATED FOR EASTERN MA SHORELINE COMMUNITIES. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ002>004. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ002>004. MA...FLOOD WATCH THROUGH LATE TONIGHT FOR MAZ005>007-011>024. WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ007-014>016- 019>024. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ007-015-016-019-022-024. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR MAZ005-006-011-012. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ003-004-009-010-026. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ002-008. RI...FLOOD WATCH THROUGH LATE TONIGHT FOR RIZ001>008. WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR RIZ006>008. MARINE...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ230>234-251. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ235>237. STORM WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ250-254>256. && $$ SYNOPSIS...BELK/SIPPRELL NEAR TERM...BELK/EVT SHORT TERM...SIPPRELL LONG TERM...BELK AVIATION...BELK/SIPPRELL MARINE...BELK/EVT HYDROLOGY...STAFF TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS ALBANY NY
1016 AM EST TUE DEC 9 2014 .SYNOPSIS... A SLOW MOVING COASTAL STORM WILL BRING A VARIETY OF WINTER WEATHER TO THE REGION FOR TODAY INTO TONIGHT. WHILE MANY VALLEY AND EASTERN AREAS WILL SEE A TRANSITION OF A WINTRY MIX TO RAIN...THE PRECIPITATION WILL BE MAINLY SNOW ACROSS THE CATSKILLS AND ADIRONDACKS...WITH A MODERATE TO HEAVY ACCUMULATION POSSIBLE IN THESE HIGH TERRAIN AREAS. WITH THE STORM REMAINING CLOSE TO THE REGION...SOME ADDITIONAL RAIN AND SNOW WILL OCCUR WEDNESDAY INTO THURSDAY AS WELL...WITH SOME ADDITIONAL SNOW ACCUMULATION POSSIBLE. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1014 AM EST...A 1004 HPA COASTAL LOW CONTINUES TO BE JUST E/SE OF THE DELMARVA REGION THIS MORNING ACCORDING TO THE LATEST MSAS MSLP ANALYSIS. THE BEST 3-HR MSLP /5-6 HPAS/FALLS ARE NORTH OF THE SFC CYCLONE. THE LATEST KENX VWP SHOWS A STRONG E/SE LLJ IN THR 3-6 KFT AGL LAYER OF 25-35 KTS. THIS PRONOUNCED LLJ HAS YIELDED SOME SIGNIFICANT DOWNSLOPING OFF THE SRN GREENS...NRN BERKS...AND THE NRN TACONICS. THE PCPN IS FINALLY TRYING TO EXPAND NORTHWARD INTO THE UPPER HUDSON REGION...AND SRN VT. THE SRN DACKS ARE ALSO SLOWLY...BUT FINALLY...GETTING INTO A THE PCPN SHIELD. THE LLJ CONTINUES TO INTENSIFY JUST S/SE OF THE REGION...AND THE BEST QG LIFT WITH THE EARLY PHASES OF THE STORM IS OVER COASTAL SRN NEW ENGLAND AND LONG ISLAND AT THIS TIME. THE STRONG LIFT WILL IMPACT THE REGION IN THE AFTERNOON. PTYPES HAVE FAVORED SLEET AND FREEZING RAIN THIS MORNING. THE 12Z KALY SOUNDING INDICATES A SLEET PROFILE. SOME HAS OCCURRED IN THE CAPITAL DISTRICT WITH THE FREEZING RAIN/DRIZZLE. SOME ICE REPORTS HAVE COME IN...WITH PERU IN THE S-CNTRL BERKS HAVING TWO TENTHS OF AN INCH. THE COLUMN CONTINUES TO WARM WITH KPOU ABOVE FREEZING WITH LIGHT RAIN...WHICH SHOULD TRANSITION TO MDT-HVY RAIN OVER THE NEXT HOUR OR TWO. WE WILL LET THE ADVISORY RUN UNTIL 11 AM...FOR ERN ULSTER/DUTCHESS/LITCHFIELD COUNTIES...AS SOME TEMPS ARE SLIGHTLY BELOW OR ARE HOVERING NEAR THE FREEZING MARK. FURTHER NORTH...THE DOWNSLOPING HAS ALLOWED KPSF/KAQW/KDDH TO ALLOW JUMP ABOVE FREEZING INTO THE MID AND U30S. SOME WET BULB COOLING SHOULD LOWER THESE TEMPS CLOSER TO FREEZING. PTYPES WERE ATTEMPTED TO BE ADJUSTED ACCORDING THE HOURLIES AND A GFS/ECMWF BLEND. MIXED PCPN WILL LIKELY LINGER FOR THE CAPITAL REGION...N-CNTRL TACONICS...BERKSHIRES...AND SRN VT INTO THE AFTERNOON BEFORE CHANGING TO RAIN. FURTHER NORTH AND WEST WILL HAVE THE BEST CHC OF SNOW...WITH A LIGHT MIXED TO SLEET/FREEZING RAIN/RAIN...BEFORE GOING BACK TO SNOW OVERNIGHT...BUT THIS WILL CONTINUE TO BE FINED TUNED. SOME OF THE PREVIOUS DISCUSSION FOLLOWS FOR THIS AFTERNOON AND TONIGHT... THERE WILL BE A SHARP CUTOFF BETWEEN SNOW VS. WINTRY MIX VS. RAIN. THE 3KM HRRR SHOWS THAT SNOW SHOULD ACCUMULATE ACROSS THE CATSKILLS/HELDERBERGS AND POINTS WESTWARD INTO THIS AFTERNOON. FURTHER NORTH...THE PRECIP WILL EXPAND INTO THE WRN MOHAWK VALLEY AND ADIRONDACKS BY THE EARLY AFTN HOURS. PRECIP LOOKS TO BE MAINLY SNOW FOR THE MOHAWK VALLEY/ADIRONDACKS...BUT WILL LIKELY MIX FOR THE SARATOGA/GLENS FALLS AREA. EVEN UP THERE...A CHANGEOVER TO RAIN LOOKS TO OCCUR DURING THE AFTN HOURS...AS WARM AIR...BOTH AT THE SFC AND ALOFT...WILL BE MOVING INTO THE AREA. FURTHER EAST...THE PRECIP WILL CHANGE TO A WINTRY MIX FOR SOUTHERN VT/BERKSHIRES AS WELL...EVEN ACROSS THE HIGH TERRAIN...AS WARM AIR ALOFT OF NEARLY 3 DEGREES C MOVES OVER THE AREA FROM THE EAST. SOME SNOW/SLEET WILL LIKELY ACCUMULATE BEFORE THE CHANGEOVER...BUT THE CHANGEOVER WILL PREVENT WARNING LEVEL SNOW FROM OCCURRING. SOME STRONG WINDS ARE POSSIBLE ACROSS THE SRN GREENS...TACONICS AND BERKSHIRES...WITH SOME GUSTS OF 25-40 MPH POSSIBLE. THE FULL BRUNT OF THE LOW LEVEL JET DOESN/T LOOK LIKE IT WILL BE ABLE TO MIX DOWN DUE TO STABLE LOW LEVELS...BUT SOME GUSTS ARE STILL POSSIBLE...ESP IN AREAS THAT CHANNEL E-SE FLOW WELL. WE WILL CONTINUE TO MENTION THIS WIND THREAT IN OUR HWO STATEMENT. AS THE BEST ISENTROPIC LIFT SHIFTS NORTH AND EAST OF THE REGION THIS EVENING...STEADY PRECIP WILL START TO SHUT OFF ACROSS OUR AREA. THE SFC LOW WILL BE MEANDERING OVER THE NYC/LONG ISLAND AREA...AND THE 500 HPA LOW WILL BECOME CUTOFF OVER THE DELMARVA AREA. AS A RESULT...SOME ADDITIONAL ON AND OFF PRECIP WILL OCCUR OVERNIGHT DUE TO THE PVA/CYCLONIC FLOW...BUT IT WILL NOT BE STEADY OR HEAVY. THERE WILL STILL BE SOME ABOVE FREEZING TEMPS ALOFT...AND THERE MAY EVEN BE A LACK OF ICE NUCLEI IN THE CLOUDS...AS THE BEST DEEPER AND COLDER CLOUD TOPS SHIFT AWAY FROM THE AREA. BECAUSE OF THIS...SOME FREEZING RAIN/DRIZZLE MAY OCCUR...ALONG WITH SOME BURSTS OF SNOW/RAIN/SLEET AS WELL. TEMPS LOOK TO HOLD STEADY IN THE LOW TO MIDDLE 30S ACROSS THE ENTIRE REGION. BECAUSE OF ALL OF THIS...WINTER STORM WARNINGS WERE NOT ISSUED OUTSIDE THE CATSKILLS/MOHAWK AND SCHOHARIE VALLEY/ADIRONDACKS BECAUSE WARNING LEVEL SNOWFALL /7 INCHES IN 12 HOURS OR 9 INCHES IN 24 HOURS/ IS NOT EXPECTED. STILL...A WINTRY MIX...EVEN THOUGH IT WILL GO OVER TO RAIN...WILL MAKE FOR HAZARDOUS TRAVEL IN THE CAPITAL REGION/GLENS FALLS AND SARATOGA AREAS/BERKSHIRES/SOUTHERN VT/...AND THIS IS WHY THE WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THESE LOCATIONS. SNOW ACCUMULATION IN THESE AREAS WILL VARY BASED ON ELEVATION...WITH JUST UP TO A FEW INCHES IN THE VALLEY AREAS...AND 2 TO 6 INCHES ACROSS THE HIGH TERRAIN. JUST A COATING TO AN INCH OF SNOW/SLEET/ICE IS EXPECTED FOR THE POUGHKEEPSIE/KINGSTON AREA AND NW CT...AS PRECIP SHOULD QUICKLY GO OVER TO RAIN THERE THIS MORNING. HOWEVER...THE FLOOD WATCH REMAINS IN EFFECT...AS HEAVY RAINFALL MAY LEAD TO SOME FLOOD CONCERNS. SEE OUR HYDRO DISCUSSION FOR MORE DETAILS ON THIS THREAT. MEANWHILE... 6 TO 12 INCHES LOOK TO ACCUMULATE IN THE CATSKILLS...HELDERBERGS...MOHAWK AND SCHOHARIE VALLEYS...AND ADIRONDACKS. EVEN IN THESE AREAS...SOME SLEET/FREEZING RAIN IS POSSIBLE AT TIMES...AND VALLEYS WILL BE ON THE LOWER END OF THE RANGE...WITH THE HIGHEST AMOUNTS IN THE HIGH PEAKS OF THE CATSKILLS IN THE GREENE COUNTY...AND IN THE HIGHEST PEAKS OF THE SRN ADIRONDACKS OF WARREN COUNTY. THE SNOW WILL BE RATHER WET...AND THIS MAY MAKE FOR SOME POWER OUTAGES/DOWNED TREE LIMBS...ESP CONSIDERING THAT STRONG NORTH WINDS ARE EXPECTED. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... A NEARLY VERTICALLY STACKED LOW OVER NEW ENGLAND WILL KEEP OUR WEATHER UNSETTLED THROUGH THE SHORT TERM PERIOD. WHILE DIFFICULT TO ASCERTAIN WHAT WAVE/S/ WILL TRIGGER ADDITIONAL PRECIPITATION...MOISTURE WILL WRAP IN OFF THE ATLANTIC TO KEEP THE HIGH PROBABILITIES IN THE FORECAST. THE BEST LOCATIONS WILL BE ALONG THE I90 CORRIDOR AND POINTS NORTHWARD. AS FOR THERMAL PROFILES...WE WILL BE COOLING DOWN THE COLUMN WHERE MOST OF THIS PRECIPITATION WILL BE IN THE FORM OF SNOW. THERE WILL BE SOME RAIN/SNOW MIXTURE INTO THE VALLEY LOCATIONS DURING THE LATE MORNING INTO THE MID AFTERNOON HOURS. THE BEST CHANCE FOR ADDITIONAL ACCUMULATIONS WILL BE INTO THE HIGHER TERRAIN. AS FOR THE SPECIFIC... WEDNESDAY...LATEST TRENDS IN THE MODEL GUIDANCE POINT TOWARD A MORE SIGNIFICANT SURGE OF MOISTURE OFF THE ATLANTIC AS THE MAIN UPPER LOW REMAINS JUST OFF THE JERSEY SHORE. MOISTURE ADVECTION AND HIGHER THETA-E /TROWAL/ BACK INTO PORTIONS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND. SPECIFIC HUMIDITIES REMAIN RATHER HIGH OF 3-4 G/KG SO WHERE IT DOES SNOW...WE COULD SEE ADDITIONAL ACCUMULATIONS OF SNOW. PER THE LATEST NCEP MODEL SUITE AND 00Z ECMWF...THIS SEEMS TO LINE UP FOR OUR NORTHERN HALF OF THE CWFA. ADDITIONAL FINE TUNING WILL TAKE PLACE AS PER CSTAR RESEARCH...THESE UPPER LOWS ARE QUITE PROBLEMATIC WITH PROVIDING SPECIFICS WHERE THE HEAVIER QPF WILL FALL. THURSDAY...AS THE LOW FILLS AND FURTHER REDUCES THE BAROCLINICITY...THE PRECIP INTENSITY AND AMOUNTS WILL DIMINISH. SO ADDITIONAL ACCUMULATIONS SHOULD BE RATHER LIGHT THROUGH THE DAY WITH JUST A COUPLE MORE INCHES OF SNOW...MAINLY INTO THE TERRAIN. THURSDAY NIGHT...WHILE THE UPPER LOW BEGINS TO SLOWLY MIGRATE EASTWARD...ITS INFLUENCES WILL CONTINUE ACROSS THE REGION. THIS WILL RESULT IN CHC-SCT SNOW PROBABILITIES WITH ADDITIONAL LIGHT ACCUMULATIONS THROUGHOUT THE REGION AS TEMPERATURES WILL BE BELOW FREEZING. WE WILL USE A BLENDED APPROACH TO THE MOS TEMPERATURES AS THEY WERE FAIRLY CLOSE IN VALUES. && .LONG TERM /FRIDAY THROUGH MONDAY/... WE MAY STILL BE DEALING WITH A CUT-OFF UPPER LEVEL LOW FOR FRIDAY INTO SATURDAY...BUT THE SYSTEM WILL HAVE LOST ITS BAROCLINICITY BY THEN RESULTING IN MAINLY SCATTERED SNOW SHOWERS. THE BEST CHANCE FOR ANY LIGHT MEASURABLE SNOWFALL WILL BE OVER THE HIGHER TERRAIN WEST AND EAST OF THE HUDSON RIVER VALLEY...AND ESPECIALLY ACROSS THE SOUTHERN ADIRONDACKS. OUR AREA WILL CONTINUE TO BE UNDER THE INFLUENCE OF THE CYCLONIC FLOW ASSOCIATED WITH THIS SYSTEM...ALTHOUGH DRIER AIR WILL GRADUALLY WORK IN FROM THE WEST...ESPECIALLY ON SATURDAY AS WE SHOULD BE ON THE WESTERN PERIPHERY OF THE CIRCULATION. SO WILL CONTINUE TO MENTION SLIGHT CHANCE TO LOW CHC POPS FOR SNOW SHOWERS FRIDAY AND FRIDAY NIGHT...DECREASING TO SLIGHT CHANCE IN THE VALLEYS FOR SATURDAY. THERE WILL CONTINUE TO BE A SOMEWHAT BETTER CHANCE FOR A PASSING SNOW SHOWER OVER THE HIGHER TERRAIN BOTH FRIDAY AND SATURDAY WITH THE NORTHWEST CYCLONIC FLOW PERSISTING. IT LOOKS LIKE DRIER WEATHER WILL FINALLY PREVAIL FOR LATE SATURDAY INTO SUNDAY...ALTHOUGH THE DEGREE OF CLOUD COVER WILL DEPEND ON HOW QUICKLY THE CUT-OFF LOW MOVES OUT TO SEA. THE ECMWF IS RATHER SLOW WITH THE DEPARTURE OF THE CUT-OFF...LINGERING CYCLONIC FLOW UNTIL SUNDAY...WHILE THE GFS HAS AN UPPER LEVEL RIDGE BUILDING IN BY LATE SATURDAY. AGAIN...THIS WILL HAVE IMPLICATIONS ON CLOUD COVER BUT WE ARE EXPECTING PRECIP-FREE CONDITIONS ON SUNDAY. DESPITE RISING UPPER LEVEL HEIGHTS/TEMPS...SURFACE TEMPS ARE ONLY EXPECTED TO BE SLIGHTLY ABOVE NORMAL DUE TO EXPECTED SHALLOW MIXING THIS TIME OF YEAR. TRANQUIL WEATHER LOOKS TO CONTINUE INTO MONDAY...WITH HIGH PRESSURE AT THE SURFACE AND ALOFT FIRMLY ENTRENCHED OVER THE REGION WITH GOOD AGREEMENT BETWEEN THE ECMWF/GFS. ANOTHER SYSTEM MAY APPROACH FROM THE WEST FOR MON NT AND TUE. WILL ADD SLIGHT CHC POPS...AS THERE IS CONSIDERABLE UNCERTAINTY FOR EARLY NEXT WEEK WHETHER A SOUTHERN STREAM SYSTEM PHASES WITH THE NORTHERN STREAM YET AGAIN...ALBEIT IN A WEAKER STATE THAN THIS WEEK. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... A SIGNIFICANT DEVELOPING COASTAL STORM WITH MULTIPLE PRECIPITATION TYPES WILL IMPACT THE AREA TODAY THROUGH WEDNESDAY. SPOTTY FREEZING DRIZZLE WILL AFFECT THE TAF SITES UNTIL THE STEADIER PRECIPITATION ARRIVES FROM SOUTH TO NORTH BETWEEN 12Z-15Z/TUE. ONCE IT ARRIVES...EACH TAF SITE WILL EXPERIENCE VARYING PRECIPITATION TYPES. MAINLY IFR/LIFR CONDITIONS ARE EXPECTED ABOUT 1-2 HOURS AFTER THE STEADIER PRECIP BEGINS. HERE ARE SOME SPECIFICS... KGFL...STEADY MIX OF SNOW/SLEET SHOULD DEVELOP BETWEEN 14Z-16Z/TUE. THIS SHOULD PERSIST FOR ABOUT 2 HOURS...BEFORE TRANSITIONING TO MAINLY A FREEZING RAIN/SLEET MIX BETWEEN 17Z-19Z/TUE. FREEZING RAIN AND SLEET...MODERATE TO HEAVY AT TIMES...SHOULD THEN CHANGE TO PLAIN RAIN BETWEEN 22Z/TUE-00Z/WED...AND GRADUALLY DECREASE IN INTENSITY. OCCASIONAL LIGHT RAIN...POSSIBLY CHANGING BACK TO SLEET OR WET SNOW...WILL LINGER THROUGH 12Z/WED. KALB...PATCHY FREEZING DRIZZLE SHOULD TRANSFORM TO STEADIER FREEZING RAIN AND SLEET BETWEEN 13Z-15Z/TUE. SOME WET SNOW COULD BE MIXED IN AT TIMES...ESP AT THE ONSET. THEN...MAINLY A FREEZING RAIN AND SLEET MIX...MODERATE TO HEAVY AT TIMES...WILL PERSIST THROUGH AROUND 19Z-21Z/TUE...BEFORE CHANGING TO PLAIN RAIN AND SOME SLEET. RAIN AND SLEET SHOULD CHANGE TO OCCASIONAL LIGHT RAIN OR DRIZZLE BETWEEN 01Z-03Z/WED. SOME SNOW COULD MIX BACK IN AFTER 05Z/WED. KPOU...A PERIOD OF FREEZING RAIN AND SOME SLEET WILL CHANGE TO PLAIN RAIN BETWEEN 13Z-15Z/TUE...WITH MODERATE TO HEAVY RAIN AT TIMES EXPECTED THROUGH MUCH OF THE AFTERNOON. RAIN SHOULD BECOME MORE INTERMITTENT AND LIGHTER AFTER 03Z/WED. KPSF...PATCHY FREEZING DRIZZLE SHOULD BECOME A STEADY MIX OF SLEET AND FREEZING RAIN BETWEEN 13Z-15Z/TUE...WITH SOME WET SNOW POSSIBLY MIXED IN AT TIMES. THIS MIX SHOULD CHANGE TO A PLAIN RAIN/SLEET MIX BETWEEN 16Z-18Z/TUE...WHICH MAY BE MODERATE TO HVY AT TIMES. PRECIPITATION SHOULD DECREASE IN INTENSITY BY OR AFTER 05Z/WED...WITH A MIX OF RAIN AND SLEET POSSIBLE. WINDS WILL INITIALLY BE N-NE AROUND 5-10 KTS...INCREASING TO 10-15 KTS WITH GUST NEAR OR EXCEEDING 20-25 KTS BY THIS AFTERNOON AND INTO TONIGHT. OUTLOOK... WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SN. THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... A FLOOD WATCH REMAINS IN EFFECT FOR LITCHFIELD COUNTY CONNECTICUT...DUTCHESS COUNTY NEW YORK AND EASTERN ULSTER COUNTY NEW YORK...FOR THIS MORNING THROUGH TONIGHT. A COASTAL STORM WILL BRING WIDESPREAD PRECIPITATION TO THE AREA FOR TODAY INTO TONIGHT. FOR NORTHWESTERN AND HIGH TERRAIN AREAS...THIS PRECIPITATION WILL FALL PRIMARY AS SNOW OR A WINTRY MIX. MEANWHILE...ACROSS SOUTHERN AND VALLEY AREAS...PRECIP WILL BEGIN AS A PERIOD OF SNOW OR A WINTRY MIX AND TRANSITION TO RAIN. TOTAL LIQUID EQUIVALENT VALUES WILL BE 0.50 OVER THE WESTERN ADIRONDACKS TO NEARLY 2.00 INCHES OVER WESTERN NEW ENGLAND. WITH MUCH OF THIS FALLING AS RAINFALL OVER LITCHFIELD COUNTY AND THE MID HUDSON VALLEY...THERE WILL BE A LOT OF RUNOFF...ESPECIALLY DURING LATE THIS MORNING THROUGH EARLY THIS EVENING WHEN PRECIP WILL BE HEAVIEST. THIS RAINFALL MAY LEAD TO MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS...ESPECIALLY IN AREAS WHERE THE GROUND IS FROZEN. RISES ON RIVERS AND STREAMS ARE LIKELY...AND MINOR FLOODING CANNOT BE RULED OUT ON THE HOUSATONIC RIVER AND IT/S TRIBUTARIES IN NW CT. IN ADDITION...THE STRONG COASTAL LOW IS ALLOWING FOR SOME TIDAL FLOODING ALONG COASTAL AREAS...AND THIS COULD CAUSE A BACKUP OF WATER ON THE HUDSON RIVER. THIS COULD LEAD TO MINOR FLOODING DURING TIMES OF HIGH TIDE IN THE POUGHKEEPSIE AREA THIS AFTERNOON. SOME ADDITIONAL PRECIPITATION...MAINLY IN THE FORM OF SNOW...IS POSSIBLE FOR WEDNESDAY INTO THURSDAY...BUT AMOUNTS ARE EXPECTED TO BE LIGHT IN AREAS THAT SEE THE HEAVIEST LIQUID PRECIP TODAY. THIS SHOULD ALLOW WATER LEVELS TO RECEDE SLOWLY OVER THE NEXT FEW DAYS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ001-013. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ001-013. NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ032-033- 038>040-042-043-047-048-051-058-063-082. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ041- 049-050-052>054-059>061-083-084. FLOOD WATCH THROUGH LATE TONIGHT FOR NYZ064>066. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ064>066. MA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ001- 025. VT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS/WASULA SHORT TERM...BGM LONG TERM...KL/JPV AVIATION...KL/JPV HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
953 AM EST TUE DEC 9 2014 .SYNOPSIS... A SIGNIFICANT COASTAL STORM WILL IMPACT THE REGION TODAY WITH WINTRY PRECIPITATION AND HEAVY RAIN...ALONG WITH STRONG TO DAMAGING WINDS. LEFTOVER LIGHT SNOW AND RAIN SHOWERS WILL PERSIST WEDNESDAY AND THURSDAY. SLOW IMPROVEMENT IS EXPECTED FRI INTO THIS WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 720 AM UPDATE... TWEAKED TEMPERATURES AND PRECIPITATION TIMING THIS MORNING. TEMPERATURES WILL BE CRUCIAL TO DETERMINING HOW MUCH ICING OCCURS THIS MORNING. ISSUED A SPECIAL WEATHER STATEMENT EARLIER TO ADDRESS THIS DURING THE MORNING COMMUTE. BEYOND THAT...FORECAST REMAINS LARGELY ON TRACK. PREVIOUS DISCUSSION... * HIGHLIGHTS... - WINTRY PRECIPITATION TYPES ERODING WITH TIME TO THE N/W - SNOW / ICE ACCUMULATIONS REMAIN AT WINTER-WX-ADVISORY LEVELS - HEAVY RAIN OF 2-3 INCHES LENDING TO POSSIBLE FLOODING - STRONG TO DAMAGING E-WINDS YIELDING WIND ADV HEADLINES * SYNOPTICALLY... PRESENT OFFSHORE LOW OFF THE MID-ATLANTIC CONUS BECOMES USURPED BY AN AMPLIFYING TROUGH DIGGING THROUGH THE E-CONUS. ACROSS A REGION OF FAVORABLE BAROCLINICITY / ATTENDANT DYNAMICS / STRONG FORCING AND DEEP-LAYER ASCENT YIELDS A RAPIDLY DEEPENING AREA OF LOW PRESSURE OFF THE DELMARVA PENINSULA THIS MORNING LIFTING N INTO S NEW ENGLAND BY EVENING. THE LOW BECOMES STALLED AND CUTOFF FROM THE MEAN FLOW UP AGAINST HIGH PRESSURE ON NEARLY ALL SIDES AS WE GO INTO THE WEEK. * HEAVY RAIN AND FLOODING... INTERROGATING DEEPER...AS THE LOW DEEPENS...EXPECT DECENT LOW-LEVEL TROWALING OF THE WARM-CONVEYER-BELT BENEATH THE RRQ/LFQ OF ATTENDANT UPPER-LEVEL JET AXES. COMBINATION OF THE CONVERGENT LEADING NOSE OF ISENTROPIC UPSLOPE LENDING TO THE TIGHTENING OF THE THERMAL GRADIENT AGAINST NEIGHBORING HIGH PRESSURE YIELDING STRONG FRONTOGENETICAL FORCING IN A REGION OF MINOR -EPV INSTABILITY BENEATH AFOREMENTIONED DEEP-LAYER ASCENT LIKELY TO RESULT IN A ROUGHLY W-E BANDING SETUP OF HIGHER WSR-88D RETURNS WITHIN A WIDESPREAD COMMA-SHAPED PRECIP FIELD ALONG THE N-PERIPHERY OF THE H85 LOW WITH THE FRONT-END THUMP OF PRECIP ANTICIPATED AROUND MIDDAY AND PERSISTING INTO EARLY EVENING. WHEW...DEEP BREATH. FEEL THE HRRR SIMULATED RADAR TRENDS ARE SHOWING THIS QUITE WELL. WILL EXPAND THE FLOOD WATCH TO INCLUDE CAPE COD AND NANTUCKET. WITH HEIGHT OF THE E/NE-WINDS AND HEAVY RAIN CONCURRENT WITH TIMING OF HIGH TIDE CENTERED AROUND 1 PM BELIEVE SURGE ALONG WITH BUILDING WAVE HEIGHTS /SEE THE MARINE DISCUSSION BELOW FOR MORE DETAILS/ WILL RESULT IN POOR-DRAINAGE ISSUES FOR COASTAL COMMUNITIES. ANTICIPATE DRAINS TO BACK-UP BECOMING OVER-TOPPED RESULTING IN SUSCEPTIBLE LOW- LYING AND POOR-DRAINAGE AREAS TO BECOME FLOODED. AM ALSO CONCERNED FOR EVEN THOSE COMMUNITIES WITHIN THE COASTAL PLAIN IN VICINITY OF RIVERS THAT ARE INFLUENCED BY THE TIDE /I.E. TAUNTON RIVER...LOWER CONNECTICUT/. COULD ALSO SEE SOME EXACERBATED FLOOD ISSUES FOR THESE AREAS. OTHERWISE REMAINDER OF THE FLOOD WATCH REMAINS IN PLACE. PWATS OF 1.25-INCHES FORECAST /ROUGHLY +2 STANDARD DEVIATIONS ABOVE-NORMAL/ AND FORECAST RAINFALL AMOUNTS OF 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS ANTICIPATED. GROUND IS PRETTY SOLID /IMPERVIOUS/ THUS EXPECT MOST OF THE RAINFALL TO BECOME RUNOFF. MAJORITY OF MAINSTEM RIVERS OVER THE INTERIOR SHOULD BE ABLE TO HANDLE THE RAIN...SO CONCERNS LIE IN THE REALM OF URBAN / POOR DRAINAGE FLOODING...ESPECIALLY IF DRAINS ARE STILL LEAF-CLOGGED. BIGGEST AREA OF CONCERN IS WITHIN THE METRO-AREA CORRIDORS...ESPECIALLY BOSTON-PROVIDENCE. MAY NEED TO EXPAND THE WATCH ACROSS N-CENTRAL AND NW MA PENDING THE TIMING AT WHICH WINTRY-PRECIP TYPES TRANSITION TO RAIN. * WINTRY PRECIPITATION... OUTCOMES DEPENDENT ON THERMAL FIELDS ALOFT...WHERE AROUND H925-H85 BY MORNING CONDITIONS ARE WARMING CONSIDERABLY UP AGAINST COLDER AIR AND HIGH PRESSURE SITUATED N/W. A SW-NE FREEZING LINE AROUND NW-CT INTO S NH INITIALLY MODIFIES NW AS THE LOW DEEPENS RESULTING IN THE INCREASE OF THE SE WARM-MOIST-CONVEYER-BELT. EXPECT THICKNESSES TO GRADUALLY RISE DURING THE HEIGHT OF THE EVENT INTO EVENING. AT THE SURFACE...AREAS BELOW FREEZING ERODE WITH INCREASING ONSHORE E/NE-WINDS DURING THE MORNING /MORE ON THAT LATER/. UNCERTAINTY CONTINUES WITH 09.0Z HIGH-RES MODELS DIFFERING IN TIMING OF EROSION. AS MENTIONED IN PRIOR DISCUSSIONS...FOR AREAS THAT ARE WITHIN OR ON THE CUSP OF BELOW-FREEZING TEMPERATURES BY 1-2C...LINGERING AN HOUR OR TWO MORE OR LESS CAN MAKE ALL THE DIFFERENCE WITH REGARDS TO WINTER-WEATHER HEAD-LINES. H975-925 AGEOSTROPHIC FLOW IS NOTABLY PERSISTENT AND STRONG OUT OF THE W AS THE LOW INTENSIFIES TOWARDS S NEW ENGLAND. BUT NOT MUCH OF A N-COMPONENT NOR FROM ARCTIC-SOURCE REGIONS...SO BELIEVE THIS WILL DO LITTLE TO MAINTAIN / PERSIST COLD AIR OVER THE REGION AGAINST STRONG ONSHORE E-FLOW. WILL GO CLOSE TO THE NEAR-TERM HIGH-RES GUIDANCE WHILE INCORPORATING THE WRF-NMM WITH REGARDS TO THERMAL FIELDS...WHICH ARE HANDLING THE SURFACE TEMPERATURES DECENTLY. PREFERENCE TO THE 09.0Z ECMWF IS ALSO GIVEN ESPECIALLY WHEN EVALUATING H100-H85 THICKNESSES. ONLY WRF-ARW AND RAP LEAN ON THE WARM SIDE OF THE GUIDANCE OVER ALL OTHERS. ALSO WILL GO WITH A TOP-DOWN APPROACH TOWARDS PRECIPITATION-TYPE THAT INCORPORATES THE INCREASING MOISTURE FROM THE S WITHIN OR ABOVE THE DENDRITIC GROWTH ZONE REGION. SO OVERALL...EXPECTING THE GRADUAL EROSION OF THE COASTAL-FRONT WITH INCREASING ONSHORE E-FLOW. PUSH OF WARMER AIR ALOFT AHEAD OF THE DEEPENING LOW WILL RESULT IN PRECIP-TYPE TRANSITION FAIRLY QUICKLY TO A SLEET / FREEZING RAIN MIX. THIS HAS SUBSEQUENTLY BUMPED DOWN SNOWFALL AMOUNTS RESULTING IN A RANGE OF 2-4 INCHES ACROSS NW MA. MOST OF THE REGION CHANGES OVER TO RAIN BY LATE MORNING INTO MIDDAY WITH ONLY THE HIGHER ELEVATIONS OF THE BERKSHIRES CONTINUALLY UNDER THE THREAT OF FREEZING RAIN. HAVE DROPPED WINTER-STORM WATCHES AND REPLACED WITH WINTER WEATHER ADVISORIES. HAVE TRIMMED THE EASTERN-EXTENT WITH EROSION OF THE COASTAL FRONT AND THE SURGE OF WARMER AIR ONSHORE. AGAIN...THE THERMAL FIELDS DISCUSSION ABOVE GIVE AN INDICATION OF PREFERRED MODEL GUIDANCE. SHOULD SEE WINTER WEATHER HEADLINES DROP MAINLY AROUND THE MIDDAY HOURS. MID-LEVEL DRY-SLOT WRAPPING INTO A DEVELOPING OCCLUSION BEGINNING TUESDAY EVENING SHOULD RESULT IN A LULL OF PRECIPITATION AS WE GO INTO WEDNESDAY MORNING. * STRONG TO DAMAGING WINDS... NOTING E-WINDS 1-2 KFT AGL WILL BE AROUND 55 MPH AROUND THE MIDDAY INTO AFTERNOON HOURS...THE PRESENCE OF WARMER AIR ALOFT LENDING TO AN INVERSION JUST ABOVE THE SURFACE MAKES IT DIFFICULT TO CONSIDER A HIGH WIND WARNING. THIS DESPITE WARMER AIR WIGGLING ITS WAY UP FROM THE S AT THE SURFACE...AND A WARMER OCEAN /THOUGH NOW AROUND THE LOW- 50S/. BOUNDARY-LAYER MIXING WILL BE LIMITED. HIGH-END WIND ADVISORY CRITERIA IS EXPECTED...BUT DO NOT EXPECT WIDESPREAD GUSTS EXCEEDING HIGH WIND WARNING CRITERIA. THUS WENT WITH THE WIND ADVISORY. COULD PRECIPITATION-DRAG PROCESSES BRING FASTER MOMENTUM TO THE SURFACE? YES...IT IS QUITE POSSIBLE...EVEN IF THUNDERSTORMS ARE IN THE MIX WHICH IS IN THE FORECAST FOR THE FAR SE-WATERS ADJACENT TO THE CAPE AND ISLANDS. HAVE GONE WITH THE HEADLINES THAT CONVEY THE HIGHEST CONFIDENCE. * COASTAL FLOODING... SEE TIDES/COASTAL FLOODING SECTION BELOW FOR DETAILS. && .SHORT TERM /WEDNESDAY/... SEE LONG TERM SECTION BELOW. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... HIGHLIGHTS... * LINGERING RAIN/SNOW SHOWERS INTO THU AS CLOSED LOW SLOWLY EXITS * IMPROVING CONDITIONS FRI INTO THIS WEEKEND DECENT MODEL AGREEMENT BOTH AT THE SURFACE AND ALOFT WEDNESDAY INTO FRIDAY. MORE SIGNIFICANT DIFFERENCES ARISE FRIDAY NIGHT INTO EARLY NEXT WEEK. AS SUCH...FAVORED A CONSENSUS BLEND TO UPDATE THIS PORTION OF THE FORECAST. THIS WAS TO SMOOTH OVER THE MINOR DIFFERENCES INTO FRIDAY...AS WELL AS MINIMIZE ERROR AFTER THAT POINT. CLOSED LOW WILL BE SLOW TO EXIT NEW ENGLAND...AND 09/00Z GUIDANCE MODELS CONTINUE TO SHOW A DEEP UPPER LOW OVER NORTHERN NEW ENGLAND FINALLY MOVING OUT TO SEA SATURDAY NIGHT. ONE OF THE PRIMARY ISSUES WITH THIS FORECAST WILL BE THE AMOUNT OF MOISTURE AVAILABLE. THINKING THERE WILL BE ENOUGH TO KEEP SKIES MOSTLY CLOUD INTO FRIDAY NIGHT. HOW MUCH WILL BE LEFTOVER TO US IN GENERATING PRECIPITATION IS ANOTHER MATTER. CONTINUED THE PREVIOUS FORECAST OF A GRADUAL DRYING OUT PROCESS FRIDAY INTO SATURDAY. HIGH PRESSURE SHOULD BE IN CONTROL OF OUR WEATHER SUNDAY INTO MONDAY. NEAR OR SLIGHTLY BELOW NORMAL TEMPERATURES EXPECTED THROUGH THIS PERIOD. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH WEDNESDAY MORNING/... 12Z UPDATE... TODAY INTO TONIGHT...MODERATE CONFIDENCE. MIX OF MVFR-IFR CIGS / VSBYS WITH MAINLY +RA. AN ISOLATED TSRA IS POSSIBLE FOR FAR SE-COASTAL TERMINALS. OTHERWISE GRADUAL EROSION TO N/W OF FZRA/PL/SN INTO THE EARLY-AFTERNOON HOURS DURING WHICH TIME WINDS WILL INCREASE OUT OF THE E WITH STRONGEST GUSTS ALONG THE E-SHORELINE MAINLY AROUND 40 KT WITH LOCALLY HIGHER GUSTS UP TO 50 KT. WILL ALSO SEE AN ACCOMPANYING LLWS THREAT WITH WINDS AROUND 2 KFT AGL OUT OF THE E AROUND 60 KTS. KBOS TERMINAL...MODERATE CONFIDENCE. FEEL CONFIDENT WITH TRENDS BUT NOT SO MUCH WITH SPECIFICS. HIGH CONFIDENCE OF CONTINUED +RA WITH INCREASING E-WINDS. GUSTS UP TO 40 KT ANTICIPATED TOWARDS THE MIDDAY HRS. WIND ADVISORY LENDING TO ISSUANCE OF AIRPORT WEATHER WARNING. KBDL TERMINAL...MODERATE CONFIDENCE. FZRA PERSISTING INTO THE EARLY-MORNING HOURS...THEN CHANGING OVER TO RAIN. NOT ABSOLUTELY CERTAIN ON TIMING BUT CONFIDENT WITH TRENDS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. MVFR/IFR IN SCATTERED RAIN OR SNOW SHOWERS. FRIDAY...MODERATE CONFIDENCE. MVFR IN ISOLATED RAIN/SNOW SHOWERS. SATURDAY...MODERATE CONFIDENCE. VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE. 5 AM UPDATE... BASED ON FORECAST CONFIDENCE...HAVE GONE WITH STORM WARNINGS FOR THE OUTER WATERS WITH THE EXPECTATION OF GUSTS AROUND 45-50 KT. BUT GREATER CONFIDENCE OF THE INNER-WATERS REACHING HIGH-END GALE WARNING CRITERIA PERMITTED THE DISCONTINUING OF THE STORM WATCH. CAN NOT RULE OUT AN ISOLATED GUST UP TO 50 KTS OVER THE INNER- WATERS...BUT WITH IT NOT ANTICIPATED TO BE WIDESPREAD...KEPT WITH GALE WARNINGS. STRONGEST E-WINDS OCCURRING TOWARDS THE MIDDAY AND CONTINUING INTO THE EARLY EVENING HOURS. SEAS BUILDING 15 TO 20 FEET WITH INCREASING E-WINDS AHEAD OF A DEEPENING AREA OF LOW PRESSURE OF THE DELMARVA PENINSULA PRESENTLY AS IT LIFTS N INTO S NEW ENGLAND TOWARDS THIS EVENING. EXPECT ACCOMPANYING HEAVY RAIN WHICH WILL YIELD VISIBILITY RESTRICTIONS ON THE WATERS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. SMALL CRAFT ADVISORIES WILL LIKELY NEED TO CONTINUE THROUGH THURSDAY NIGHT ACROSS THE OCEAN-EXPOSED COASTAL WATERS...MAINLY DUE TO ROUGH SEAS. THERE COULD ALSO BE SOME WEST/SOUTHWEST GUSTS UP TO 25 KT AS WELL. ALSO SHOULD SEE LEFTOVER SCATTERED RAIN/SNOW SHOWERS. FRIDAY INTO SATURDAY...MODERATE CONFIDENCE. SLOW IMPROVEMENT CONTINUES WITH DIMINISHING WINDS AND SEAS. SEAS SHOULD FINALLY DROP BELOW 5 FT ACROSS ALL BUT THE OUTERMOST COASTAL WATERS FRI EVENING...THEN REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS ACROSS ALL WATERS SATURDAY. && .HYDROLOGY... UPDATED 950 AM TUE... EXPANDED FLOOD WATCH TO INCLUDE MARTHAS VINEYARD AND BLOCK ISLAND. ALTHOUGH RAINFALL TOTALS WILL BE 1.5 TO 2.5 INCHES...COMBINATION OF RAINFALL AND RISING TIDE THROUGH EARLY AFTERNOON MAY LEAD TO SIGNIFICANT FLOODING ESPECIALLY ON E/SE SHORELINES. BUOYS REPORTING 5-6 FT SEAS ON NANTUCKET SOUND AND 11 FT SE OF BLOCK ISLAND. SIMILAR SITUATION FOR CAPE COD AND NANTUCKET. MAIN CONCERN CONTINUES TO BE POTENTIAL FOR SIGNIFICANT URBAN FLOODING...ESPECIALLY IN RI AND E MA. ALREADY SEEING RAINFALL RATES OF NEARLY 2 INCHES PER HOUR ACROSS SOUTHERN CT /KSNC ASOS/ WHICH WILL TRANSLATE OVER OUR AREA BY EARLY AFTERNOON. SOME OF THE URBAN HOT SPOTS SUCH AS PEABODY...FALL RIVER...NEW BEDFORD AND CRANSTON MAY BE ESPECIALLY VULNERABLE TO FLOODING. TOTALS OF 2 TO 3 INCHES ARE EXPECTED WITH A FEW 3 OR 4 INCH TOTALS NOT OUT OF QUESTION NEAR I-95 CORRIDOR. FLOODING OF SMALL STREAMS IS ALSO A POSSIBILITY...BUT WORST CASE WOULD BE FOR MINOR FLOODING IF TOTALS EXCEED 3 INCHES. NOT EXPECTING FLOODING OF LARGER RIVERS. LATEST NERFC GUIDANCE BRINGS LOWER CT RIVER AT MIDDLE HADDAM TO ACTION STAGE...WHICH IS PRIMARILY BASED ON SURGE OF 2 FT INTO LOWER CT RIVER. WE MAY ALSO SEE SIMILAR SURGE ALONG PAWCATUCK RIVER NEAR WESTERLY RI WHICH COULD BRING RISES SLIGHTLY HIGHER THAN CURRENTLY FORECAST. && .TIDES/COASTAL FLOODING... COASTAL FLOOD ADVISORY CONTINUES FOR EASTERN MA. COMBINATION OF WINDS / SEAS / SURGE OF AROUND 1.5 TO 2 FEET DURING THE MIDDAY HIGH-TIDE YIELDS THE LIKELIHOOD OF OBSERVING MINOR COASTAL FLOODING AND BEACH EROSION FOR E-FACING SHORELINES WHERE SEAS OF 12 TO 15 FEET ARE POSSIBLE. AS NOTED IN THE HYDROLOGY PORTION ABOVE...LOCAL STREAMS AND TRIBUTARIES EMPTYING INTO THE SEA COULD SEE BACK-FILLING ISSUES AS THE HEAVY RAIN IS ANTICIPATED DURING THE TIME OF HIGH-TIDE. COULD SEE FLOODING ISSUES EXACERBATED FOR EASTERN MA SHORELINE COMMUNITIES. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ002>004. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ002>004. MA...FLOOD WATCH THROUGH LATE TONIGHT FOR MAZ005>007-011>024. WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ007-014>016- 019>024. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ007-015-016-019-022-024. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR MAZ005-006-011-012. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ003-004-009-010-026. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ002-008. RI...FLOOD WATCH THROUGH LATE TONIGHT FOR RIZ001>008. WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR RIZ006>008. MARINE...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ231>234-251. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ230. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ235>237. STORM WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ250-254>256. && $$ SYNOPSIS...BELK/SIPPRELL NEAR TERM...BELK/SIPPRELL SHORT TERM...SIPPRELL LONG TERM...BELK AVIATION...BELK/SIPPRELL MARINE...BELK/SIPPRELL HYDROLOGY...JWD TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
721 AM EST TUE DEC 9 2014 .SYNOPSIS... A SIGNIFICANT COASTAL STORM WILL IMPACT THE REGION TODAY WITH WINTRY PRECIPITATION AND HEAVY RAIN...ALONG WITH STRONG TO DAMAGING WINDS. LEFTOVER LIGHT SNOW AND RAIN SHOWERS WILL PERSIST WEDNESDAY AND THURSDAY. SLOW IMPROVEMENT IS EXPECTED FRI INTO THIS WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 720 AM UPDATE... TWEAKED TEMPERATURES AND PRECIPITATION TIMING THIS MORNING. TEMPERATURES WILL BE CRUCIAL TO DETERMINING HOW MUCH ICING OCCURS THIS MORNING. ISSUED A SPECIAL WEATHER STATEMENT EARLIER TO ADDRESS THIS DURING THE MORNING COMMUTE. BEYOND THAT...FORECAST REMAINS LARGELY ON TRACK. PREVIOUS DISCUSSION... * HIGHLIGHTS... - WINTRY PRECIPITATION TYPES ERODING WITH TIME TO THE N/W - SNOW / ICE ACCUMULATIONS REMAIN AT WINTER-WX-ADVISORY LEVELS - HEAVY RAIN OF 2-3 INCHES LENDING TO POSSIBLE FLOODING - STRONG TO DAMAGING E-WINDS YIELDING WIND ADV HEADLINES * SYNOPTICALLY... PRESENT OFFSHORE LOW OFF THE MID-ATLANTIC CONUS BECOMES USURPED BY AN AMPLIFYING TROUGH DIGGING THROUGH THE E-CONUS. ACROSS A REGION OF FAVORABLE BAROCLINICITY / ATTENDANT DYNAMICS / STRONG FORCING AND DEEP-LAYER ASCENT YIELDS A RAPIDLY DEEPENING AREA OF LOW PRESSURE OFF THE DELMARVA PENINSULA THIS MORNING LIFTING N INTO S NEW ENGLAND BY EVENING. THE LOW BECOMES STALLED AND CUTOFF FROM THE MEAN FLOW UP AGAINST HIGH PRESSURE ON NEARLY ALL SIDES AS WE GO INTO THE WEEK. * HEAVY RAIN AND FLOODING... INTERROGATING DEEPER...AS THE LOW DEEPENS...EXPECT DECENT LOW-LEVEL TROWALING OF THE WARM-CONVEYER-BELT BENEATH THE RRQ/LFQ OF ATTENDANT UPPER-LEVEL JET AXES. COMBINATION OF THE CONVERGENT LEADING NOSE OF ISENTROPIC UPSLOPE LENDING TO THE TIGHTENING OF THE THERMAL GRADIENT AGAINST NEIGHBORING HIGH PRESSURE YIELDING STRONG FRONTOGENETICAL FORCING IN A REGION OF MINOR -EPV INSTABILITY BENEATH AFOREMENTIONED DEEP-LAYER ASCENT LIKELY TO RESULT IN A ROUGHLY W-E BANDING SETUP OF HIGHER WSR-88D RETURNS WITHIN A WIDESPREAD COMMA-SHAPED PRECIP FIELD ALONG THE N-PERIPHERY OF THE H85 LOW WITH THE FRONT-END THUMP OF PRECIP ANTICIPATED AROUND MIDDAY AND PERSISTING INTO EARLY EVENING. WHEW...DEEP BREATH. FEEL THE HRRR SIMULATED RADAR TRENDS ARE SHOWING THIS QUITE WELL. WILL EXPAND THE FLOOD WATCH TO INCLUDE CAPE COD AND NANTUCKET. WITH HEIGHT OF THE E/NE-WINDS AND HEAVY RAIN CONCURRENT WITH TIMING OF HIGH TIDE CENTERED AROUND 1 PM BELIEVE SURGE ALONG WITH BUILDING WAVE HEIGHTS /SEE THE MARINE DISCUSSION BELOW FOR MORE DETAILS/ WILL RESULT IN POOR-DRAINAGE ISSUES FOR COASTAL COMMUNITIES. ANTICIPATE DRAINS TO BACK-UP BECOMING OVER-TOPPED RESULTING IN SUSCEPTIBLE LOW- LYING AND POOR-DRAINAGE AREAS TO BECOME FLOODED. AM ALSO CONCERNED FOR EVEN THOSE COMMUNITIES WITHIN THE COASTAL PLAIN IN VICINITY OF RIVERS THAT ARE INFLUENCED BY THE TIDE /I.E. TAUNTON RIVER...LOWER CONNECTICUT/. COULD ALSO SEE SOME EXACERBATED FLOOD ISSUES FOR THESE AREAS. OTHERWISE REMAINDER OF THE FLOOD WATCH REMAINS IN PLACE. PWATS OF 1.25-INCHES FORECAST /ROUGHLY +2 STANDARD DEVIATIONS ABOVE-NORMAL/ AND FORECAST RAINFALL AMOUNTS OF 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS ANTICIPATED. GROUND IS PRETTY SOLID /IMPERVIOUS/ THUS EXPECT MOST OF THE RAINFALL TO BECOME RUNOFF. MAJORITY OF MAINSTEM RIVERS OVER THE INTERIOR SHOULD BE ABLE TO HANDLE THE RAIN...SO CONCERNS LIE IN THE REALM OF URBAN / POOR DRAINAGE FLOODING...ESPECIALLY IF DRAINS ARE STILL LEAF-CLOGGED. BIGGEST AREA OF CONCERN IS WITHIN THE METRO-AREA CORRIDORS...ESPECIALLY BOSTON-PROVIDENCE. MAY NEED TO EXPAND THE WATCH ACROSS N-CENTRAL AND NW MA PENDING THE TIMING AT WHICH WINTRY-PRECIP TYPES TRANSITION TO RAIN. * WINTRY PRECIPITATION... OUTCOMES DEPENDENT ON THERMAL FIELDS ALOFT...WHERE AROUND H925-H85 BY MORNING CONDITIONS ARE WARMING CONSIDERABLY UP AGAINST COLDER AIR AND HIGH PRESSURE SITUATED N/W. A SW-NE FREEZING LINE AROUND NW-CT INTO S NH INITIALLY MODIFIES NW AS THE LOW DEEPENS RESULTING IN THE INCREASE OF THE SE WARM-MOIST-CONVEYER-BELT. EXPECT THICKNESSES TO GRADUALLY RISE DURING THE HEIGHT OF THE EVENT INTO EVENING. AT THE SURFACE...AREAS BELOW FREEZING ERODE WITH INCREASING ONSHORE E/NE-WINDS DURING THE MORNING /MORE ON THAT LATER/. UNCERTAINTY CONTINUES WITH 09.0Z HIGH-RES MODELS DIFFERING IN TIMING OF EROSION. AS MENTIONED IN PRIOR DISCUSSIONS...FOR AREAS THAT ARE WITHIN OR ON THE CUSP OF BELOW-FREEZING TEMPERATURES BY 1-2C...LINGERING AN HOUR OR TWO MORE OR LESS CAN MAKE ALL THE DIFFERENCE WITH REGARDS TO WINTER-WEATHER HEAD-LINES. H975-925 AGEOSTROPHIC FLOW IS NOTABLY PERSISTENT AND STRONG OUT OF THE W AS THE LOW INTENSIFIES TOWARDS S NEW ENGLAND. BUT NOT MUCH OF A N-COMPONENT NOR FROM ARCTIC-SOURCE REGIONS...SO BELIEVE THIS WILL DO LITTLE TO MAINTAIN / PERSIST COLD AIR OVER THE REGION AGAINST STRONG ONSHORE E-FLOW. WILL GO CLOSE TO THE NEAR-TERM HIGH-RES GUIDANCE WHILE INCORPORATING THE WRF-NMM WITH REGARDS TO THERMAL FIELDS...WHICH ARE HANDLING THE SURFACE TEMPERATURES DECENTLY. PREFERENCE TO THE 09.0Z ECMWF IS ALSO GIVEN ESPECIALLY WHEN EVALUATING H100-H85 THICKNESSES. ONLY WRF-ARW AND RAP LEAN ON THE WARM SIDE OF THE GUIDANCE OVER ALL OTHERS. ALSO WILL GO WITH A TOP-DOWN APPROACH TOWARDS PRECIPITATION-TYPE THAT INCORPORATES THE INCREASING MOISTURE FROM THE S WITHIN OR ABOVE THE DENDRITIC GROWTH ZONE REGION. SO OVERALL...EXPECTING THE GRADUAL EROSION OF THE COASTAL-FRONT WITH INCREASING ONSHORE E-FLOW. PUSH OF WARMER AIR ALOFT AHEAD OF THE DEEPENING LOW WILL RESULT IN PRECIP-TYPE TRANSITION FAIRLY QUICKLY TO A SLEET / FREEZING RAIN MIX. THIS HAS SUBSEQUENTLY BUMPED DOWN SNOWFALL AMOUNTS RESULTING IN A RANGE OF 2-4 INCHES ACROSS NW MA. MOST OF THE REGION CHANGES OVER TO RAIN BY LATE MORNING INTO MIDDAY WITH ONLY THE HIGHER ELEVATIONS OF THE BERKSHIRES CONTINUALLY UNDER THE THREAT OF FREEZING RAIN. HAVE DROPPED WINTER-STORM WATCHES AND REPLACED WITH WINTER WEATHER ADVISORIES. HAVE TRIMMED THE EASTERN-EXTENT WITH EROSION OF THE COASTAL FRONT AND THE SURGE OF WARMER AIR ONSHORE. AGAIN...THE THERMAL FIELDS DISCUSSION ABOVE GIVE AN INDICATION OF PREFERRED MODEL GUIDANCE. SHOULD SEE WINTER WEATHER HEADLINES DROP MAINLY AROUND THE MIDDAY HOURS. MID-LEVEL DRY-SLOT WRAPPING INTO A DEVELOPING OCCLUSION BEGINNING TUESDAY EVENING SHOULD RESULT IN A LULL OF PRECIPITATION AS WE GO INTO WEDNESDAY MORNING. * STRONG TO DAMAGING WINDS... NOTING E-WINDS 1-2 KFT AGL WILL BE AROUND 55 MPH AROUND THE MIDDAY INTO AFTERNOON HOURS...THE PRESENCE OF WARMER AIR ALOFT LENDING TO AN INVERSION JUST ABOVE THE SURFACE MAKES IT DIFFICULT TO CONSIDER A HIGH WIND WARNING. THIS DESPITE WARMER AIR WIGGLING ITS WAY UP FROM THE S AT THE SURFACE...AND A WARMER OCEAN /THOUGH NOW AROUND THE LOW- 50S/. BOUNDARY-LAYER MIXING WILL BE LIMITED. HIGH-END WIND ADVISORY CRITERIA IS EXPECTED...BUT DO NOT EXPECT WIDESPREAD GUSTS EXCEEDING HIGH WIND WARNING CRITERIA. THUS WENT WITH THE WIND ADVISORY. COULD PRECIPITATION-DRAG PROCESSES BRING FASTER MOMENTUM TO THE SURFACE? YES...IT IS QUITE POSSIBLE...EVEN IF THUNDERSTORMS ARE IN THE MIX WHICH IS IN THE FORECAST FOR THE FAR SE-WATERS ADJACENT TO THE CAPE AND ISLANDS. HAVE GONE WITH THE HEADLINES THAT CONVEY THE HIGHEST CONFIDENCE. * COASTAL FLOODING... SEE TIDES/COASTAL FLOODING SECTION BELOW FOR DETAILS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * LINGERING RAIN/SNOW SHOWERS INTO THU AS CLOSED LOW SLOWLY EXITS * IMPROVING CONDITIONS FRI INTO THIS WEEKEND DECENT MODEL AGREEMENT BOTH AT THE SURFACE AND ALOFT WEDNESDAY INTO FRIDAY. MORE SIGNIFICANT DIFFERENCES ARISE FRIDAY NIGHT INTO EARLY NEXT WEEK. AS SUCH...FAVORED A CONSENSUS BLEND TO UPDATE THIS PORTION OF THE FORECAST. THIS WAS TO SMOOTH OVER THE MINOR DIFFERENCES INTO FRIDAY...AS WELL AS MINIMIZE ERROR AFTER THAT POINT. CLOSED LOW WILL BE SLOW TO EXIT NEW ENGLAND...AND 09/00Z GUIDANCE MODELS CONTINUE TO SHOW A DEEP UPPER LOW OVER NORTHERN NEW ENGLAND FINALLY MOVING OUT TO SEA SATURDAY NIGHT. ONE OF THE PRIMARY ISSUES WITH THIS FORECAST WILL BE THE AMOUNT OF MOISTURE AVAILABLE. THINKING THERE WILL BE ENOUGH TO KEEP SKIES MOSTLY CLOUD INTO FRIDAY NIGHT. HOW MUCH WILL BE LEFTOVER TO US IN GENERATING PRECIPITATION IS ANOTHER MATTER. CONTINUED THE PREVIOUS FORECAST OF A GRADUAL DRYING OUT PROCESS FRIDAY INTO SATURDAY. HIGH PRESSURE SHOULD BE IN CONTROL OF OUR WEATHER SUNDAY INTO MONDAY. NEAR OR SLIGHTLY BELOW NORMAL TEMPERATURES EXPECTED THROUGH THIS PERIOD. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH WEDNESDAY MORNING/... 12Z UPDATE... TODAY INTO TONIGHT...MODERATE CONFIDENCE. MIX OF MVFR-IFR CIGS / VSBYS WITH MAINLY +RA. AN ISOLATED TSRA IS POSSIBLE FOR FAR SE-COASTAL TERMINALS. OTHERWISE GRADUAL EROSION TO N/W OF FZRA/PL/SN INTO THE EARLY-AFTERNOON HOURS DURING WHICH TIME WINDS WILL INCREASE OUT OF THE E WITH STRONGEST GUSTS ALONG THE E-SHORELINE MAINLY AROUND 40 KT WITH LOCALLY HIGHER GUSTS UP TO 50 KT. WILL ALSO SEE AN ACCOMPANYING LLWS THREAT WITH WINDS AROUND 2 KFT AGL OUT OF THE E AROUND 60 KTS. KBOS TERMINAL...MODERATE CONFIDENCE. FEEL CONFIDENT WITH TRENDS BUT NOT SO MUCH WITH SPECIFICS. HIGH CONFIDENCE OF CONTINUED +RA WITH INCREASING E-WINDS. GUSTS UP TO 40 KT ANTICIPATED TOWARDS THE MIDDAY HRS. WIND ADVISORY LENDING TO ISSUANCE OF AIRPORT WEATHER WARNING. KBDL TERMINAL...MODERATE CONFIDENCE. FZRA PERSISTING INTO THE EARLY-MORNING HOURS...THEN CHANGING OVER TO RAIN. NOT ABSOLUTELY CERTAIN ON TIMING BUT CONFIDENT WITH TRENDS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. MVFR/IFR IN SCATTERED RAIN OR SNOW SHOWERS. FRIDAY...MODERATE CONFIDENCE. MVFR IN ISOLATED RAIN/SNOW SHOWERS. SATURDAY...MODERATE CONFIDENCE. VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE. 5 AM UPDATE... BASED ON FORECAST CONFIDENCE...HAVE GONE WITH STORM WARNINGS FOR THE OUTER WATERS WITH THE EXPECTATION OF GUSTS AROUND 45-50 KT. BUT GREATER CONFIDENCE OF THE INNER-WATERS REACHING HIGH-END GALE WARNING CRITERIA PERMITTED THE DISCONTINUING OF THE STORM WATCH. CAN NOT RULE OUT AN ISOLATED GUST UP TO 50 KTS OVER THE INNER- WATERS...BUT WITH IT NOT ANTICIPATED TO BE WIDESPREAD...KEPT WITH GALE WARNINGS. STRONGEST E-WINDS OCCURRING TOWARDS THE MIDDAY AND CONTINUING INTO THE EARLY EVENING HOURS. SEAS BUILDING 15 TO 20 FEET WITH INCREASING E-WINDS AHEAD OF A DEEPENING AREA OF LOW PRESSURE OF THE DELMARVA PENINSULA PRESENTLY AS IT LIFTS N INTO S NEW ENGLAND TOWARDS THIS EVENING. EXPECT ACCOMPANYING HEAVY RAIN WHICH WILL YIELD VISIBILITY RESTRICTIONS ON THE WATERS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. SMALL CRAFT ADVISORIES WILL LIKELY NEED TO CONTINUE THROUGH THURSDAY NIGHT ACROSS THE OCEAN-EXPOSED COASTAL WATERS...MAINLY DUE TO ROUGH SEAS. THERE COULD ALSO BE SOME WEST/SOUTHWEST GUSTS UP TO 25 KT AS WELL. ALSO SHOULD SEE LEFTOVER SCATTERED RAIN/SNOW SHOWERS. FRIDAY INTO SATURDAY...MODERATE CONFIDENCE. SLOW IMPROVEMENT CONTINUES WITH DIMINISHING WINDS AND SEAS. SEAS SHOULD FINALLY DROP BELOW 5 FT ACROSS ALL BUT THE OUTERMOST COASTAL WATERS FRI EVENING...THEN REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS ACROSS ALL WATERS SATURDAY. && .HYDROLOGY... STORM-TOTAL RAINFALL AMOUNTS OF 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS EXPECTED THROUGH WEDNESDAY MORNING. WITH A HARDENED GROUND BY ALL THE RECENT COLD WEATHER...AND THE COMBINED THREAT OF BOTH LEAF-CLOGGED DRAINS AND THE HIGH TIDE ALONG THE E-SHORELINE AROUND MIDDAY...HAVE EXPANDED THE FLOOD WATCH FOR CAPE COD AND NANTUCKET AND CONTINUED THE WATCH OVERALL WITH THE THREAT OF URBAN AND POOR-DRAINAGE FLOODING. SMALLER STREAMS AND RIVERS ESPECIALLY ALONG THE COAST COULD SEE FLOODING AS HIGH TIDE AND SUBSEQUENT SURGE VIA E-WINDS LIMITS DRAINAGE TO THE OCEAN. RIVERS CONSEQUENTIALLY BACK-FILLING. MAIN AREA OF FOCUS IS ON AREAS AROUND THE I-95 CORRIDOR AND TOWARDS THE S/E. WILL ALSO NEED TO KEEP AN EYE OUT FOR THE POSSIBILITY OF ISOLATED THUNDERSTORMS OVER THE FAR SE WHICH COULD YIELD LOCALIZED HEAVY RAIN. LATEST NERFC GUIDANCE BRINGS LOWER CT RIVER AT MIDDLE HADDAM TO ACTION STAGE...WHICH IS PRIMARILY BASED ON SURGE OF 2 FT INTO LOWER CT RIVER. WE MAY ALSO SEE SIMILAR SURGE ALONG PAWCATUCK RIVER NEAR WESTERLY RI WHICH COULD BRING RISES SLIGHTLY HIGHER THAN CURRENTLY FORECAST. && .TIDES/COASTAL FLOODING... COASTAL FLOOD ADVISORY CONTINUES FOR EASTERN MA. COMBINATION OF WINDS / SEAS / SURGE OF AROUND 1.5 TO 2 FEET DURING THE MIDDAY HIGH-TIDE YIELDS THE LIKELIHOOD OF OBSERVING MINOR COASTAL FLOODING AND BEACH EROSION FOR E-FACING SHORELINES WHERE SEAS OF 12 TO 15 FEET ARE POSSIBLE. AS NOTED IN THE HYDROLOGY PORTION ABOVE...LOCAL STREAMS AND TRIBUTARIES EMPTYING INTO THE SEA COULD SEE BACK-FILLING ISSUES AS THE HEAVY RAIN IS ANTICIPATED DURING THE TIME OF HIGH-TIDE. COULD SEE FLOODING ISSUES EXACERBATED FOR EASTERN MA SHORELINE COMMUNITIES. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ002>004. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ002>004. MA...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ007-014>016- 019>024. FLOOD WATCH THROUGH LATE TONIGHT FOR MAZ005>007-011>022-024. COASTAL FLOOD ADVISORY FROM 11 AM THIS MORNING TO 3 PM EST THIS AFTERNOON FOR MAZ007-015-016-019-022-024. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR MAZ005-006-011-012. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ003-004-009-010-026. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ002-008. RI...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR RIZ006>008. FLOOD WATCH THROUGH LATE TONIGHT FOR RIZ001>007. MARINE...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ231>234-251. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ230. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ235>237. STORM WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ250-254>256. && $$ SYNOPSIS...BELK/SIPPRELL NEAR TERM...BELK/SIPPRELL SHORT TERM...SIPPRELL LONG TERM...BELK AVIATION...BELK/SIPPRELL MARINE...BELK/SIPPRELL HYDROLOGY... TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
632 AM EST TUE DEC 9 2014 .SYNOPSIS... A SLOW MOVING COASTAL STORM WILL BRING A VARIETY OF WINTER WEATHER TO THE REGION FOR TODAY INTO TONIGHT. WHILE MANY VALLEY AND EASTERN AREAS WILL SEE A TRANSITION OF A WINTRY MIX TO RAIN...THE PRECIPITATION WILL BE MAINLY SNOW ACROSS THE CATSKILLS AND ADIRONDACKS...WITH A MODERATE TO HEAVY ACCUMULATION POSSIBLE IN THESE HIGH TERRAIN AREAS. WITH THE STORM REMAINING CLOSE TO THE REGION...SOME ADDITIONAL RAIN AND SNOW WILL OCCUR WEDNESDAY INTO THURSDAY AS WELL...WITH SOME ADDITIONAL SNOW ACCUMULATION POSSIBLE. && .NEAR TERM /THROUGH TONIGHT/... AS OF 632 AM EST...A 1007 HPA COASTAL LOW IS CURRENTLY SITUATED OFF THE COAST OF WALLOPS ISLAND VIRGINIA . THIS LOW IS CONTINUING TO LIFT NORTHWARD...AND 3 HR PRESSURE FALLS OF IN EXCESS OF 5 MBS ARE OCCURRING OFF THE COAST OF THE DELAWARE BEACHES. AN UPPER LEVEL SHORTWAVE TROUGH IS DIVING OUT OF THE GREAT LAKES/MIDWEST REGION...AND THIS UPPER LEVEL SHORTWAVE WILL BE CAPTURING THE SFC WAVE...AND CAUSING IT TO BASICALLY STALL JUST OFF THE NEW JERSEY SHORE TODAY. A STRONG LOW LEVEL JET IN EXCESS OF 50 KTS IS ADVECTING PLENTY OF MOISTURE AND WARM AIR ALOFT INTO THE REGION. THE LATEST REGIONAL MOSAIC RADAR SHOWS A STEADY BATCH OF MODERATE TO HEAVY PRECIP OVER NORTHERN NJ AND THE NYC METRO AREA...AND THIS PRECIP IS QUICKLY ADVANCING NORTHWARD INTO OUR AREA. IN ADVANCE OF THIS STEADY PRECIP...SOME LIGHT FREEZING DRIZZLE/MIST IS OCCURRING...AS THE LOW LEVELS ARE STARTING TO MOISTEN UP IN ADVANCE OF THE MAIN SLUG OF PRECIP. WE/VE RECEIVED REPORTS OF ROADS BECOMING SLICK DUE TO THIS VERY LIGHT FREEZING DRIZZLE FALLING ON SURFACES WITH THE COLD AIR IN PLACE. A FEW SPS STATEMENTS/SOCIAL MEDIA UPDATES...IN ADDITION TO OUR ONGOING WSWS...HAVE ADDRESSED THIS FREEZING DRIZZLE THREAT FOR THE NEXT FEW HOURS. MODEL SOUNDINGS SUGGEST PRECIP WILL BEGIN AS A WINTRY MIX FOR THE MID HUDSON VALLEY AND NW CT...AS A WARM NOSE BETWEEN 850 AND 925 HPA WILL BE IN PLACE. AS THIS PRECIP ADVANCES FURTHER NORTH...IT LOOKS TO BE SNOW/SLEET ACROSS THE CATSKILLS...BUT WILL PROBABLY BE A SLEET/FREEZING RAIN MIX AS IT REACHES THE CAPITAL REGION AND TACONICS. WE WILL HAVE TO WATCH OUR SFC TEMPS CLOSELY...AS AN EXTENDED PERIOD OF FREEZING RAIN COULD CAUSE US TO MAKE DRASTIC CHANGES TO OUR ONGOING FORECAST. THE LATEST GUIDANCE SUGGEST FREEZING RAIN...AND NOT SNOW...IS THE FORECAST ISSUE FOR THE CAPITAL REGION AND POINTS EASTWARD THIS MORNING. THERE WILL BE A SHARP CUTOFF BETWEEN SNOW VS. WINTRY MIX VS. RAIN. THE 3KM HRRR SHOWS THAT SNOW SHOULD ACCUMULATE ACROSS THE CATSKILLS/HELDERBERGS AND POINTS WESTWARD THIS MORNING...BUT ANY SNOW/SLEET ACCUMULATION WILL BE LIMITED TO JUST A FEW HOURS FOR THE HUDSON VALLEY...TACONICS AND NW CT...BEFORE PRECIP CHANGES TO FREEZING RAIN AND THEN A PLAIN RAIN. SFC TEMPS LOOK TO NUDGE JUST ABOVE FREEZING BY THE MID MORNING FOR THE MID HUDSON VALLEY...AND LATE MORNING HOURS IN THE CAPITAL REGION. AS STATED EARLIER...THESE SFC TEMPS WILL HAVE TO BE MONITORED VERY CLOSELY...TO SEE IF THE SFC TEMPS HANG COLDER LONGER THAN ANTICIPATED. FURTHER NORTH...THE PRECIP WILL EXPAND INTO THE MOHAWK VALLEY AND ADIRONDACKS BY THE EARLY AFTN HOURS. PRECIP LOOKS TO BE MAINLY SNOW FOR THE MOHAWK VALLEY/ADIRONDACKS...BUT WILL LIKELY MIX FOR THE SARATOGA/GLENS FALLS AREA. EVEN UP THERE...A CHANGEOVER TO RAIN LOOKS TO OCCUR DURING THE AFTN HOURS...AS WARM AIR...BOTH AT THE SFC AND ALOFT...WILL BE MOVING INTO THE AREA. FURTHER EAST...THE PRECIP WILL CHANGE TO A WINTRY MIX FOR SOUTHERN VT/BERKSHIRES AS WELL...EVEN ACROSS THE HIGH TERRAIN...AS WARM AIR ALOFT OF NEARLY 3 DEGREES C MOVES OVER THE AREA FROM THE EAST. SOME SNOW/SLEET WILL LIKELY ACCUMULATE BEFORE THE CHANGEOVER...BUT THE CHANGEOVER WILL PREVENT WARNING LEVEL SNOW FROM OCCURRING. SOME STRONG WINDS ARE POSSIBLE ACROSS THE SRN GREENS...TACONICS AND BERKSHIRES...WITH SOME GUSTS OF 25-40 MPH POSSIBLE. THE FULL BRUNT OF THE LOW LEVEL JET DOESN/T LOOK LIKE IT WILL BE ABLE TO MIX DOWN DUE TO STABLE LOW LEVELS...BUT SOME GUSTS ARE STILL POSSIBLE...ESP IN AREAS THAT CHANNEL E-SE FLOW WELL. WE WILL CONTINUE TO MENTION THIS WIND THREAT IN OUR HWO STATEMENT. AS THE BEST ISENTROPIC LIFT SHIFTS NORTH AND EAST OF THE REGION THIS EVENING...STEADY PRECIP WILL START TO SHUT OFF ACROSS OUR AREA. THE SFC LOW WILL BE MEANDERING OVER THE NYC/LONG ISLAND AREA...AND THE 500 HPA LOW WILL BECOME CUTOFF OVER THE DELMARVA AREA. AS A RESULT...SOME ADDITIONAL ON AND OFF PRECIP WILL OCCUR OVERNIGHT DUE TO THE PVA/CYCLONIC FLOW...BUT IT WILL NOT BE STEADY OR HEAVY. THERE WILL STILL BE SOME ABOVE FREEZING TEMPS ALOFT...AND THERE MAY EVEN BE A LACK OF ICE NUCLEI IN THE CLOUDS...AS THE BEST DEEPER AND COLDER CLOUD TOPS SHIFT AWAY FROM THE AREA. BECAUSE OF THIS...SOME FREEZING RAIN/DRIZZLE MAY OCCUR...ALONG WITH SOME BURSTS OF SNOW/RAIN/SLEET AS WELL. TEMPS LOOK TO HOLD STEADY IN THE LOW TO MIDDLE 30S ACROSS THE ENTIRE REGION. BECAUSE OF ALL OF THIS...WINTER STORM WARNINGS WERE NOT ISSUED OUTSIDE THE CATSKILLS/MOHAWK AND SCHOHARIE VALLEY/ADIRONDACKS BECAUSE WARNING LEVEL SNOWFALL /7 INCHES IN 12 HOURS OR 9 INCHES IN 24 HOURS/ IS NOT EXPECTED. STILL...A WINTRY MIX...EVEN THOUGH IT WILL GO OVER TO RAIN...WILL MAKE FOR HAZARDOUS TRAVEL IN THE CAPITAL REGION/GLENS FALLS AND SARATOGA AREAS/BERKSHIRES/SOUTHERN VT/...AND THIS IS WHY THE WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THESE LOCATIONS. SNOW ACCUMULATION IN THESE AREAS WILL VARY BASED ON ELEVATION...WITH JUST UP TO A FEW INCHES IN THE VALLEY AREAS...AND 2 TO 6 INCHES ACROSS THE HIGH TERRAIN. JUST A COATING TO AN INCH OF SNOW/SLEET/ICE IS EXPECTED FOR THE POUGHKEEPSIE/KINGSTON AREA AND NW CT...AS PRECIP SHOULD QUICKLY GO OVER TO RAIN THERE THIS MORNING. HOWEVER...THE FLOOD WATCH REMAINS IN EFFECT...AS HEAVY RAINFALL MAY LEAD TO SOME FLOOD CONCERNS. SEE OUR HYDRO DISCUSSION FOR MORE DETAILS ON THIS THREAT. MEANWHILE... 6 TO 12 INCHES LOOK TO ACCUMULATE IN THE CATSKILLS...HELDERBERGS...MOHAWK AND SCHOHARIE VALLEYS...AND ADIRONDACKS. EVEN IN THESE AREAS...SOME SLEET/FREEZING RAIN IS POSSIBLE AT TIMES...AND VALLEYS WILL BE ON THE LOWER END OF THE RANGE...WITH THE HIGHEST AMOUNTS IN THE HIGH PEAKS OF THE CATSKILLS IN THE GREENE COUNTY...AND IN THE HIGHEST PEAKS OF THE SRN ADIRONDACKS OF WARREN COUNTY. THE SNOW WILL BE RATHER WET...AND THIS MAY MAKE FOR SOME POWER OUTAGES/DOWNED TREE LIMBS...ESP CONSIDERING THAT STRONG NORTH WINDS ARE EXPECTED. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... A NEARLY VERTICALLY STACKED LOW OVER NEW ENGLAND WILL KEEP OUR WEATHER UNSETTLED THROUGH THE SHORT TERM PERIOD. WHILE DIFFICULT TO ASCERTAIN WHAT WAVE/S/ WILL TRIGGER ADDITIONAL PRECIPITATION...MOISTURE WILL WRAP IN OFF THE ATLANTIC TO KEEP THE HIGH PROBABILITIES IN THE FORECAST. THE BEST LOCATIONS WILL BE ALONG THE I90 CORRIDOR AND POINTS NORTHWARD. AS FOR THERMAL PROFILES...WE WILL BE COOLING DOWN THE COLUMN WHERE MOST OF THIS PRECIPITATION WILL BE IN THE FORM OF SNOW. THERE WILL BE SOME RAIN/SNOW MIXTURE INTO THE VALLEY LOCATIONS DURING THE LATE MORNING INTO THE MID AFTERNOON HOURS. THE BEST CHANCE FOR ADDITIONAL ACCUMULATIONS WILL BE INTO THE HIGHER TERRAIN. AS FOR THE SPECIFIC... WEDNESDAY...LATEST TRENDS IN THE MODEL GUIDANCE POINT TOWARD A MORE SIGNIFICANT SURGE OF MOISTURE OFF THE ATLANTIC AS THE MAIN UPPER LOW REMAINS JUST OFF THE JERSEY SHORE. MOISTURE ADVECTION AND HIGHER THETA-E /TROWAL/ BACK INTO PORTIONS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND. SPECIFIC HUMIDITIES REMAIN RATHER HIGH OF 3-4 G/KG SO WHERE IT DOES SNOW...WE COULD SEE ADDITIONAL ACCUMULATIONS OF SNOW. PER THE LATEST NCEP MODEL SUITE AND 00Z ECMWF...THIS SEEMS TO LINE UP FOR OUR NORTHERN HALF OF THE CWFA. ADDITIONAL FINE TUNING WILL TAKE PLACE AS PER CSTAR RESEARCH...THESE UPPER LOWS ARE QUITE PROBLEMATIC WITH PROVIDING SPECIFICS WHERE THE HEAVIER QPF WILL FALL. THURSDAY...AS THE LOW FILLS AND FURTHER REDUCES THE BAROCLINICITY...THE PRECIP INTENSITY AND AMOUNTS WILL DIMINISH. SO ADDITIONAL ACCUMULATIONS SHOULD BE RATHER LIGHT THROUGH THE DAY WITH JUST A COUPLE MORE INCHES OF SNOW...MAINLY INTO THE TERRAIN. THURSDAY NIGHT...WHILE THE UPPER LOW BEGINS TO SLOWLY MIGRATE EASTWARD...ITS INFLUENCES WILL CONTINUE ACROSS THE REGION. THIS WILL RESULT IN CHC-SCT SNOW PROBABILITIES WITH ADDITIONAL LIGHT ACCUMULATIONS THROUGHOUT THE REGION AS TEMPERATURES WILL BE BELOW FREEZING. WE WILL USE A BLENDED APPROACH TO THE MOS TEMPERATURES AS THEY WERE FAIRLY CLOSE IN VALUES. && .LONG TERM /FRIDAY THROUGH MONDAY/... WE MAY STILL BE DEALING WITH A CUT-OFF UPPER LEVEL LOW FOR FRIDAY INTO SATURDAY...BUT THE SYSTEM WILL HAVE LOST ITS BAROCLINICITY BY THEN RESULTING IN MAINLY SCATTERED SNOW SHOWERS. THE BEST CHANCE FOR ANY LIGHT MEASURABLE SNOWFALL WILL BE OVER THE HIGHER TERRAIN WEST AND EAST OF THE HUDSON RIVER VALLEY...AND ESPECIALLY ACROSS THE SOUTHERN ADIRONDACKS. OUR AREA WILL CONTINUE TO BE UNDER THE INFLUENCE OF THE CYCLONIC FLOW ASSOCIATED WITH THIS SYSTEM...ALTHOUGH DRIER AIR WILL GRADUALLY WORK IN FROM THE WEST...ESPECIALLY ON SATURDAY AS WE SHOULD BE ON THE WESTERN PERIPHERY OF THE CIRCULATION. SO WILL CONTINUE TO MENTION SLIGHT CHANCE TO LOW CHC POPS FOR SNOW SHOWERS FRIDAY AND FRIDAY NIGHT...DECREASING TO SLIGHT CHANCE IN THE VALLEYS FOR SATURDAY. THERE WILL CONTINUE TO BE A SOMEWHAT BETTER CHANCE FOR A PASSING SNOW SHOWER OVER THE HIGHER TERRAIN BOTH FRIDAY AND SATURDAY WITH THE NORTHWEST CYCLONIC FLOW PERSISTING. IT LOOKS LIKE DRIER WEATHER WILL FINALLY PREVAIL FOR LATE SATURDAY INTO SUNDAY...ALTHOUGH THE DEGREE OF CLOUD COVER WILL DEPEND ON HOW QUICKLY THE CUT-OFF LOW MOVES OUT TO SEA. THE ECMWF IS RATHER SLOW WITH THE DEPARTURE OF THE CUT-OFF...LINGERING CYCLONIC FLOW UNTIL SUNDAY...WHILE THE GFS HAS AN UPPER LEVEL RIDGE BUILDING IN BY LATE SATURDAY. AGAIN...THIS WILL HAVE IMPLICATIONS ON CLOUD COVER BUT WE ARE EXPECTING PRECIP-FREE CONDITIONS ON SUNDAY. DESPITE RISING UPPER LEVEL HEIGHTS/TEMPS...SURFACE TEMPS ARE ONLY EXPECTED TO BE SLIGHTLY ABOVE NORMAL DUE TO EXPECTED SHALLOW MIXING THIS TIME OF YEAR. TRANQUIL WEATHER LOOKS TO CONTINUE INTO MONDAY...WITH HIGH PRESSURE AT THE SURFACE AND ALOFT FIRMLY ENTRENCHED OVER THE REGION WITH GOOD AGREEMENT BETWEEN THE ECMWF/GFS. ANOTHER SYSTEM MAY APPROACH FROM THE WEST FOR MON NT AND TUE. WILL ADD SLIGHT CHC POPS...AS THERE IS CONSIDERABLE UNCERTAINTY FOR EARLY NEXT WEEK WHETHER A SOUTHERN STREAM SYSTEM PHASES WITH THE NORTHERN STREAM YET AGAIN...ALBEIT IN A WEAKER STATE THAN THIS WEEK. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... A SIGNIFICANT DEVELOPING COASTAL STORM WITH MULTIPLE PRECIPITATION TYPES WILL IMPACT THE AREA TODAY THROUGH WEDNESDAY. SPOTTY FREEZING DRIZZLE WILL AFFECT THE TAF SITES UNTIL THE STEADIER PRECIPITATION ARRIVES FROM SOUTH TO NORTH BETWEEN 12Z-15Z/TUE. ONCE IT ARRIVES...EACH TAF SITE WILL EXPERIENCE VARYING PRECIPITATION TYPES. MAINLY IFR/LIFR CONDITIONS ARE EXPECTED ABOUT 1-2 HOURS AFTER THE STEADIER PRECIP BEGINS. HERE ARE SOME SPECIFICS... KGFL...STEADY MIX OF SNOW/SLEET SHOULD DEVELOP BETWEEN 14Z-16Z/TUE. THIS SHOULD PERSIST FOR ABOUT 2 HOURS...BEFORE TRANSITIONING TO MAINLY A FREEZING RAIN/SLEET MIX BETWEEN 17Z-19Z/TUE. FREEZING RAIN AND SLEET...MODERATE TO HEAVY AT TIMES...SHOULD THEN CHANGE TO PLAIN RAIN BETWEEN 22Z/TUE-00Z/WED...AND GRADUALLY DECREASE IN INTENSITY. OCCASIONAL LIGHT RAIN...POSSIBLY CHANGING BACK TO SLEET OR WET SNOW...WILL LINGER THROUGH 12Z/WED. KALB...PATCHY FREEZING DRIZZLE SHOULD TRANSFORM TO STEADIER FREEZING RAIN AND SLEET BETWEEN 13Z-15Z/TUE. SOME WET SNOW COULD BE MIXED IN AT TIMES...ESP AT THE ONSET. THEN...MAINLY A FREEZING RAIN AND SLEET MIX...MODERATE TO HEAVY AT TIMES...WILL PERSIST THROUGH AROUND 19Z-21Z/TUE...BEFORE CHANGING TO PLAIN RAIN AND SOME SLEET. RAIN AND SLEET SHOULD CHANGE TO OCCASIONAL LIGHT RAIN OR DRIZZLE BETWEEN 01Z-03Z/WED. SOME SNOW COULD MIX BACK IN AFTER 05Z/WED. KPOU...A PERIOD OF FREEZING RAIN AND SOME SLEET WILL CHANGE TO PLAIN RAIN BETWEEN 13Z-15Z/TUE...WITH MODERATE TO HEAVY RAIN AT TIMES EXPECTED THROUGH MUCH OF THE AFTERNOON. RAIN SHOULD BECOME MORE INTERMITTENT AND LIGHTER AFTER 03Z/WED. KPSF...PATCHY FREEZING DRIZZLE SHOULD BECOME A STEADY MIX OF SLEET AND FREEZING RAIN BETWEEN 13Z-15Z/TUE...WITH SOME WET SNOW POSSIBLY MIXED IN AT TIMES. THIS MIX SHOULD CHANGE TO A PLAIN RAIN/SLEET MIX BETWEEN 16Z-18Z/TUE...WHICH MAY BE MODERATE TO HVY AT TIMES. PRECIPITATION SHOULD DECREASE IN INTENSITY BY OR AFTER 05Z/WED...WITH A MIX OF RAIN AND SLEET POSSIBLE. WINDS WILL INITIALLY BE N-NE AROUND 5-10 KTS...INCREASING TO 10-15 KTS WITH GUST NEAR OR EXCEEDING 20-25 KTS BY THIS AFTERNOON AND INTO TONIGHT. OUTLOOK... WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SN. THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... A FLOOD WATCH REMAINS IN EFFECT FOR LITCHFIELD COUNTY CONNECTICUT...DUTCHESS COUNTY NEW YORK AND EASTERN ULSTER COUNTY NEW YORK...FOR THIS MORNING THROUGH TONIGHT. A COASTAL STORM WILL BRING WIDESPREAD PRECIPITATION TO THE AREA FOR TODAY INTO TONIGHT. FOR NORTHWESTERN AND HIGH TERRAIN AREAS...THIS PRECIPITATION WILL FALL PRIMARY AS SNOW OR A WINTRY MIX. MEANWHILE...ACROSS SOUTHERN AND VALLEY AREAS...PRECIP WILL BEGIN AS A PERIOD OF SNOW OR A WINTRY MIX AND TRANSITION TO RAIN. TOTAL LIQUID EQUIVALENT VALUES WILL BE 0.50 OVER THE WESTERN ADIRONDACKS TO NEARLY 2.00 INCHES OVER WESTERN NEW ENGLAND. WITH MUCH OF THIS FALLING AS RAINFALL OVER LITCHFIELD COUNTY AND THE MID HUDSON VALLEY...THERE WILL BE A LOT OF RUNOFF...ESPECIALLY DURING LATE THIS MORNING THROUGH EARLY THIS EVENING WHEN PRECIP WILL BE HEAVIEST. THIS RAINFALL MAY LEAD TO MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS...ESPECIALLY IN AREAS WHERE THE GROUND IS FROZEN. RISES ON RIVERS AND STREAMS ARE LIKELY...AND MINOR FLOODING CANNOT BE RULED OUT ON THE HOUSATONIC RIVER AND IT/S TRIBUTARIES IN NW CT. IN ADDITION...THE STRONG COASTAL LOW IS ALLOWING FOR SOME TIDAL FLOODING ALONG COASTAL AREAS...AND THIS COULD CAUSE A BACKUP OF WATER ON THE HUDSON RIVER. THIS COULD LEAD TO MINOR FLOODING DURING TIMES OF HIGH TIDE IN THE POUGHKEEPSIE AREA THIS AFTERNOON. SOME ADDITIONAL PRECIPITATION...MAINLY IN THE FORM OF SNOW...IS POSSIBLE FOR WEDNESDAY INTO THURSDAY...BUT AMOUNTS ARE EXPECTED TO BE LIGHT IN AREAS THAT SEE THE HEAVIEST LIQUID PRECIP TODAY. THIS SHOULD ALLOW WATER LEVELS TO RECEDE SLOWLY OVER THE NEXT FEW DAYS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ001-013. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ001-013. NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ032-033- 038>040-042-043-047-048-051-058-063-082. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ041- 049-050-052>054-059>061-083-084. FLOOD WATCH THROUGH LATE TONIGHT FOR NYZ064>066. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ064>066. MA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ001- 025. VT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS SHORT TERM...BGM LONG TERM...KL/JPV AVIATION...KL/JPV HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
528 AM EST TUE DEC 9 2014 .SYNOPSIS... A SIGNIFICANT COASTAL STORM WILL IMPACT THE REGION TODAY WITH WINTRY PRECIPITATION AND HEAVY RAIN...ALONG WITH STRONG TO DAMAGING WINDS. LEFTOVER LIGHT SNOW AND RAIN SHOWERS WILL PERSIST WEDNESDAY AND THURSDAY. SLOW IMPROVEMENT IS EXPECTED FRI INTO THIS WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... */ HIGHLIGHTS... - WINTRY PRECIPITATION TYPES ERODING WITH TIME TO THE N/W - SNOW / ICE ACCUMULATIONS REMAIN AT WINTER-WX-ADVISORY LEVELS - HEAVY RAIN OF 2-3 INCHES LENDING TO POSSIBLE FLOODING - STRONG TO DAMAGING E-WINDS YIELDING WIND ADV HEADLINES */ SYNOPTICALLY... PRESENT OFFSHORE LOW OFF THE MID-ATLANTIC CONUS BECOMES USURPED BY AN AMPLIFYING TROUGH DIGGING THROUGH THE E-CONUS. ACROSS A REGION OF FAVORABLE BAROCLINICITY / ATTENDANT DYNAMICS / STRONG FORCING AND DEEP-LAYER ASCENT YIELDS A RAPIDLY DEEPENING AREA OF LOW PRESSURE OFF THE DELMARVA PENINSULA THIS MORNING LIFTING N INTO S NEW ENGLAND BY EVENING. THE LOW BECOMES STALLED AND CUTOFF FROM THE MEAN FLOW UP AGAINST HIGH PRESSURE ON NEARLY ALL SIDES AS WE GO INTO THE WEEK. */ HEAVY RAIN AND FLOODING... INTERROGATING DEEPER...AS THE LOW DEEPENS...EXPECT DECENT LOW-LEVEL TROWALING OF THE WARM-CONVEYER-BELT BENEATH THE RRQ/LFQ OF ATTENDANT UPPER-LEVEL JET AXES. COMBINATION OF THE CONVERGENT LEADING NOSE OF ISENTROPIC UPSLOPE LENDING TO THE TIGHTENING OF THE THERMAL GRADIENT AGAINST NEIGHBORING HIGH PRESSURE YIELDING STRONG FRONTOGENETICAL FORCING IN A REGION OF MINOR -EPV INSTABILITY BENEATH AFOREMENTIONED DEEP-LAYER ASCENT LIKELY TO RESULT IN A ROUGHLY W-E BANDING SETUP OF HIGHER WSR-88D RETURNS WITHIN A WIDESPREAD COMMA-SHAPED PRECIP FIELD ALONG THE N-PERIPHERY OF THE H85 LOW WITH THE FRONT-END THUMP OF PRECIP ANTICIPATED AROUND MIDDAY AND PERSISTING INTO EARLY EVENING. WHEW...DEEP BREATH. FEEL THE HRRR SIMULATED RADAR TRENDS ARE SHOWING THIS QUITE WELL. WILL EXPAND THE FLOOD WATCH TO INCLUDE CAPE COD AND NANTUCKET. WITH HEIGHT OF THE E/NE-WINDS AND HEAVY RAIN CONCURRENT WITH TIMING OF HIGH TIDE CENTERED AROUND 1 PM BELIEVE SURGE ALONG WITH BUILDING WAVE HEIGHTS /SEE THE MARINE DISCUSSION BELOW FOR MORE DETAILS/ WILL RESULT IN POOR-DRAINAGE ISSUES FOR COASTAL COMMUNITIES. ANTICIPATE DRAINS TO BACK-UP BECOMING OVER-TOPPED RESULTING IN SUSCEPTIBLE LOW- LYING AND POOR-DRAINAGE AREAS TO BECOME FLOODED. AM ALSO CONCERNED FOR EVEN THOSE COMMUNITIES WITHIN THE COASTAL PLAIN IN VICINITY OF RIVERS THAT ARE INFLUENCED BY THE TIDE /I.E. TAUNTON RIVER...LOWER CONNECTICUT/. COULD ALSO SEE SOME EXACERBATED FLOOD ISSUES FOR THESE AREAS. OTHERWISE REMAINDER OF THE FLOOD WATCH REMAINS IN PLACE. PWATS OF 1.25-INCHES FORECAST /ROUGHLY +2 STANDARD DEVIATIONS ABOVE-NORMAL/ AND FORECAST RAINFALL AMOUNTS OF 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS ANTICIPATED. GROUND IS PRETTY SOLID /IMPERVIOUS/ THUS EXPECT MOST OF THE RAINFALL TO BECOME RUNOFF. MAJORITY OF MAINSTEM RIVERS OVER THE INTERIOR SHOULD BE ABLE TO HANDLE THE RAIN...SO CONCERNS LIE IN THE REALM OF URBAN / POOR DRAINAGE FLOODING...ESPECIALLY IF DRAINS ARE STILL LEAF-CLOGGED. BIGGEST AREA OF CONCERN IS WITHIN THE METRO-AREA CORRIDORS...ESPECIALLY BOSTON-PROVIDENCE. MAY NEED TO EXPAND THE WATCH ACROSS N-CENTRAL AND NW MA PENDING THE TIMING AT WHICH WINTRY-PRECIP TYPES TRANSITION TO RAIN. */ WINTRY PRECIPITATION... OUTCOMES DEPENDENT ON THERMAL FIELDS ALOFT...WHERE AROUND H925-H85 BY MORNING CONDITIONS ARE WARMING CONSIDERABLY UP AGAINST COLDER AIR AND HIGH PRESSURE SITUATED N/W. A SW-NE FREEZING LINE AROUND NW-CT INTO S NH INITIALLY MODIFIES NW AS THE LOW DEEPENS RESULTING IN THE INCREASE OF THE SE WARM-MOIST-CONVEYER-BELT. EXPECT THICKNESSES TO GRADUALLY RISE DURING THE HEIGHT OF THE EVENT INTO EVENING. AT THE SURFACE...AREAS BELOW FREEZING ERODE WITH INCREASING ONSHORE E/NE-WINDS DURING THE MORNING /MORE ON THAT LATER/. UNCERTAINTY CONTINUES WITH 09.0Z HIGH-RES MODELS DIFFERING IN TIMING OF EROSION. AS MENTIONED IN PRIOR DISCUSSIONS...FOR AREAS THAT ARE WITHIN OR ON THE CUSP OF BELOW-FREEZING TEMPERATURES BY 1-2C...LINGERING AN HOUR OR TWO MORE OR LESS CAN MAKE ALL THE DIFFERENCE WITH REGARDS TO WINTER-WEATHER HEAD-LINES. H975-925 AGEOSTROPHIC FLOW IS NOTABLY PERSISTENT AND STRONG OUT OF THE W AS THE LOW INTENSIFIES TOWARDS S NEW ENGLAND. BUT NOT MUCH OF A N-COMPONENT NOR FROM ARCTIC-SOURCE REGIONS...SO BELIEVE THIS WILL DO LITTLE TO MAINTAIN / PERSIST COLD AIR OVER THE REGION AGAINST STRONG ONSHORE E-FLOW. WILL GO CLOSE TO THE NEAR-TERM HIGH-RES GUIDANCE WHILE INCORPORATING THE WRF-NMM WITH REGARDS TO THERMAL FIELDS...WHICH ARE HANDLING THE SURFACE TEMPERATURES DECENTLY. PREFERENCE TO THE 09.0Z ECMWF IS ALSO GIVEN ESPECIALLY WHEN EVALUATING H100-H85 THICKNESSES. ONLY WRF-ARW AND RAP LEAN ON THE WARM SIDE OF THE GUIDANCE OVER ALL OTHERS. ALSO WILL GO WITH A TOP-DOWN APPROACH TOWARDS PRECIPITATION-TYPE THAT INCORPORATES THE INCREASING MOISTURE FROM THE S WITHIN OR ABOVE THE DENDRITIC GROWTH ZONE REGION. SO OVERALL...EXPECTING THE GRADUAL EROSION OF THE COASTAL-FRONT WITH INCREASING ONSHORE E-FLOW. PUSH OF WARMER AIR ALOFT AHEAD OF THE DEEPENING LOW WILL RESULT IN PRECIP-TYPE TRANSITION FAIRLY QUICKLY TO A SLEET / FREEZING RAIN MIX. THIS HAS SUBSEQUENTLY BUMPED DOWN SNOWFALL AMOUNTS RESULTING IN A RANGE OF 2-4 INCHES ACROSS NW MA. MOST OF THE REGION CHANGES OVER TO RAIN BY LATE MORNING INTO MIDDAY WITH ONLY THE HIGHER ELEVATIONS OF THE BERKSHIRES CONTINUALLY UNDER THE THREAT OF FREEZING RAIN. HAVE DROPPED WINTER-STORM WATCHES AND REPLACED WITH WINTER WEATHER ADVISORIES. HAVE TRIMMED THE EASTERN-EXTENT WITH EROSION OF THE COASTAL FRONT AND THE SURGANCE OF WARMER AIR ONSHORE. AGAIN...THE THERMAL FIELDS DISCUSSION ABOVE GIVE AN INDICATION OF PREFERRED MODEL GUIDANCE. SHOULD SEE WINTER WEATHER HEADLINES DROP MAINLY AROUND THE MIDDAY HOURS. MID-LEVEL DRY-SLOT WRAPPING INTO A DEVELOPING OCCLUSION BEGINNING TUESDAY EVENING SHOULD RESULT IN A LULL OF PRECIPITATION AS WE GO INTO WEDNESDAY MORNING. */ STRONG TO DAMAGING WINDS... NOTING E-WINDS 1-2 KFT AGL WILL BE AROUND 55 MPH AROUND THE MIDDAY INTO AFTERNOON HOURS...THE PRESENCE OF WARMER AIR ALOFT LENDING TO AN INVERSION JUST ABOVE THE SURFACE MAKES IT DIFFICULT TO CONSIDER A HIGH WIND WARNING. THIS DESPITE WARMER AIR WIGGLING ITS WAY UP FROM THE S AT THE SURFACE...AND A WARMER OCEAN /THOUGH NOW AROUND THE LOW- 50S/. BOUNDARY-LAYER MIXING WILL BE LIMITED. HIGH-END WIND ADVISORY CRITERIA IS EXPECTED...BUT DO NOT EXPECT WIDESPREAD GUSTS EXCEEDING HIGH WIND WARNING CRITERIA. THUS WENT WITH THE WIND ADVISORY. COULD PRECIPITATION-DRAG PROCESSES BRING FASTER MOMENTUM TO THE SURFACE? YES...IT IS QUITE POSSIBLE...EVEN IF THUNDERSTORMS ARE IN THE MIX WHICH IS IN THE FORECAST FOR THE FAR SE-WATERS ADJACENT TO THE CAPE AND ISLANDS. HAVE GONE WITH THE HEADLINES THAT CONVEY THE HIGHEST CONFIDENCE. */ COASTAL FLOODING... SEE TIDES/COASTAL FLOODING SECTION BELOW FOR DETAILS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * LINGERING RAIN/SNOW SHOWERS INTO THU AS CLOSED LOW SLOWLY EXITS * IMPROVING CONDITIONS FRI INTO THIS WEEKEND DECENT MODEL AGREEMENT BOTH AT THE SURFACE AND ALOFT WEDNESDAY INTO FRIDAY. MORE SIGNIFICANT DIFFERENCES ARISE FRIDAY NIGHT INTO EARLY NEXT WEEK. AS SUCH...FAVORED A CONSENSUS BLEND TO UPDATE THIS PORTION OF THE FORECAST. THIS WAS TO SMOOTH OVER THE MINOR DIFFERENCES INTO FRIDAY...AS WELL AS MINIMIZE ERROR AFTER THAT POINT. CLOSED LOW WILL BE SLOW TO EXIT NEW ENGLAND...AND 09/00Z GUIDANCE MODELS CONTINUE TO SHOW A DEEP UPPER LOW OVER NORTHERN NEW ENGLAND FINALLY MOVING OUT TO SEA SATURDAY NIGHT. ONE OF THE PRIMARY ISSUES WITH THIS FORECAST WILL BE THE AMOUNT OF MOISTURE AVAILABLE. THINKING THERE WILL BE ENOUGH TO KEEP SKIES MOSTLY CLOUD INTO FRIDAY NIGHT. HOW MUCH WILL BE LEFTOVER TO US IN GENERATING PRECIPITATION IS ANOTHER MATTER. CONTINUED THE PREVIOUS FORECAST OF A GRADUAL DRYING OUT PROCESS FRIDAY INTO SATURDAY. HIGH PRESSURE SHOULD BE IN CONTROL OF OUR WEATHER SUNDAY INTO MONDAY. NEAR OR SLIGHTLY BELOW NORMAL TEMPERATURES EXPECTED THROUGH THIS PERIOD. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH WEDNESDAY MORNING/... 10Z UPDATE... TODAY INTO TONIGHT...MODERATE CONFIDENCE. MIX OF MVFR-IFR CIGS / VSBYS WITH MAINLY +RA. AN ISOLATED TSRA IS POSSIBLE FOR FAR SE-COASTAL TERMINALS. OTHERWISE GRADUAL EROSION TO N/W OF FZRA/PL/SN INTO THE EARLY-AFTERNOON HOURS DURING WHICH TIME WINDS WILL INCREASE OUT OF THE E WITH STRONGEST GUSTS ALONG THE E-SHORELINE MAINLY AROUND 40 KT WITH LOCALLY HIGHER GUSTS UP TO 50 KT. WILL ALSO SEE AN ACCOMPANYING LLWS THREAT WITH WINDS AROUND 2 KFT AGL OUT OF THE E AROUND 60 KTS. KBOS TERMINAL...MODERATE CONFIDENCE. FEEL CONFIDENT WITH TRENDS BUT NOT SO MUCH WITH SPECIFICS. HIGH CONFIDENCE OF CONTINUED +RA WITH INCREASING E-WINDS. GUSTS UP TO 40 KT ANTICIPATED TOWARDS THE MIDDAY HRS. WIND ADV LENDING TO ISSUANCE OF AWW. KBDL TERMINAL...MODERATE CONFIDENCE. FZRA PERSISTING INTO THE EARLY-MORNING HOURS THEN CHANGING OVER TO RAIN. NOT ABSOLUTELY CERTAIN ON TIMING BUT CONFIDENT WITH TRENDS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. MVFR/IFR IN SCATTERED RAIN OR SNOW SHOWERS. FRIDAY...MODERATE CONFIDENCE. MVFR IN ISOLATED RAIN/SNOW SHOWERS. SATURDAY...MODERATE CONFIDENCE. VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE. 5 AM UPDATE... BASED ON FORECAST CONFIDENCE...HAVE GONE WITH STORM WARNINGS FOR THE OUTER WATERS WITH THE EXPECTATION OF GUSTS AROUND 45-50 KT. BUT GREATER CONFIDENCE OF THE INNER-WATERS REACHING HIGH-END GALE WARNING CRITERIA PERMITTED THE DISCONTINUING OF THE STORM WATCH. CAN NOT RULE OUT AN ISOLATED GUST UP TO 50 KTS OVER THE INNER- WATERS...BUT WITH IT NOT ANTICIPATED TO BE WIDESPREAD...KEPT WITH GALE WARNINGS. STRONGEST E-WINDS OCCURRING TOWARDS THE MIDDAY AND CONTINUING INTO THE EARLY EVENING HOURS. SEAS BUILDING 15 TO 20 FEET WITH INCREASING E-WINDS AHEAD OF A DEEPENING AREA OF LOW PRESSURE OF THE DELMARVA PENINSULA PRESENTLY AS IT LIFTS N INTO S NEW ENGLAND TOWARDS THIS EVENING. EXPECT ACCOMPANYING HEAVY RAIN WHICH WILL YIELD VISIBILITY RESTRICTIONS ON THE WATERS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. SMALL CRAFT ADVISORIES WILL LIKELY NEED TO CONTINUE THROUGH THURSDAY NIGHT ACROSS THE OCEAN-EXPOSED COASTAL WATERS...MAINLY DUE TO ROUGH SEAS. THERE COULD ALSO BE SOME WEST/SOUTHWEST GUSTS UP TO 25 KT AS WELL. ALSO SHOULD SEE LEFTOVER SCATTERED RAIN/SNOW SHOWERS. FRIDAY INTO SATURDAY...MODERATE CONFIDENCE. SLOW IMPROVEMENT CONTINUES WITH DIMINISHING WINDS AND SEAS. SEAS SHOULD FINALLY DROP BELOW 5 FT ACROSS ALL BUT THE OUTERMOST COASTAL WATERS FRI EVENING...THEN REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS ACROSS ALL WATERS SATURDAY. && .HYDROLOGY... STORM-TOTAL RAINFALL AMOUNTS OF 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS EXPECTED THROUGH WEDNESDAY MORNING. WITH A HARDENED GROUND BY ALL THE RECENT COLD WEATHER...AND THE COMBINED THREAT OF BOTH LEAF-CLOGGED DRAINS AND THE HIGH TIDE ALONG THE E-SHORELINE AROUND MIDDAY...HAVE EXPANDED THE FLOOD WATCH FOR CAPE COD AND NANTUCKET AND CONTINUED THE WATCH OVERALL WITH THE THREAT OF URBAN AND POOR-DRAINAGE FLOODING. SMALLER STREAMS AND RIVERS ESPECIALLY ALONG THE COAST COULD SEE FLOODING AS HIGH TIDE AND SUBSEQUENT SURGE VIA E-WINDS LIMITS DRAINAGE TO THE OCEAN. RIVERS CONSEQUENTIALLY BACK-FILLING. MAIN AREA OF FOCUS IS ON AREAS AROUND THE I-95 CORRIDOR AND TOWARDS THE S/E. WILL ALSO NEED TO KEEP AN EYE OUT FOR THE POSSIBILITY OF ISOLATED THUNDERSTORMS OVER THE FAR SE WHICH COULD YIELD LOCALIZED HEAVY RAIN. LATEST NERFC GUIDANCE BRINGS LOWER CT RIVER AT MIDDLE HADDAM TO ACTION STAGE...WHICH IS PRIMARILY BASED ON SURGE OF 2 FT INTO LOWER CT RIVER. WE MAY ALSO SEE SIMILAR SURGE ALONG PAWCATUCK RIVER NEAR WESTERLY RI WHICH COULD BRING RISES SLIGHTLY HIGHER THAN CURRENTLY FORECAST. && .TIDES/COASTAL FLOODING... COASTAL FLOOD ADVISORY CONTINUES FOR EASTERN MA. COMBINATION OF WINDS / SEAS / SURGE OF AROUND 1.5 TO 2 FEET DURING THE MIDDAY HIGH-TIDE YIELDS THE LIKELIHOOD OF OBSERVING MINOR COASTAL FLOODING AND BEACH EROSION FOR E-FACING SHORELINES WHERE SEAS OF 12 TO 15 FEET ARE POSSIBLE. AS NOTED IN THE HYDROLOGY PORTION ABOVE...LOCAL STREAMS AND TRIBUTARIES EMPTYING INTO THE SEA COULD SEE BACK-FILLING ISSUES AS THE HEAVY RAIN IS ANTICIPATED DURING THE TIME OF HIGH-TIDE. COULD SEE FLOODING ISSUES EXACERBATED FOR EASTERN MA SHORELINE COMMUNITIES. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ002>004. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ002>004. MA...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM EST THIS EVENING FOR MAZ007-014>016-019>024. FLOOD WATCH THROUGH LATE TONIGHT FOR MAZ005>007-011>022-024. COASTAL FLOOD ADVISORY FROM 11 AM THIS MORNING TO 3 PM EST THIS AFTERNOON FOR MAZ007-015-016-019-022-024. WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR MAZ005-006-011-012. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ003-004-009-010-026. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MAZ013. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ002-008. RI...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM EST THIS EVENING FOR RIZ006>008. FLOOD WATCH THROUGH LATE TONIGHT FOR RIZ001>007. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR RIZ001- 003. MARINE...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ231>234-251. GALE WARNING FROM 10 AM THIS MORNING TO 10 PM EST THIS EVENING FOR ANZ230. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ236. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ235-237. STORM WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ250-254>256. && $$ SYNOPSIS...BELK/SIPPRELL NEAR TERM...SIPPRELL SHORT TERM...SIPPRELL LONG TERM...BELK AVIATION...BELK/SIPPRELL MARINE...BELK/SIPPRELL HYDROLOGY...SIPPRELL TIDES/COASTAL FLOODING...SIPPRELL
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1026 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THE MID-MORNING UPDATE...THE FORECAST FROM EARLIER THIS MORNING IS BASICALLY ON TRACK BUT HAVE MADE ADJUSTMENTS TO SOME OF THE HAZARDS. AS OF 900 AM TEMPS ACROSS ALL THE FCST AREA SEEM TO HAVE RISEN ABOVE FREEZING AND ALL REPORTED PRECIP IS RAIN...SO THE WINTER WEATHER ADVISORY FOR PARTS OF NW NJ AND ERN PA HAS BEEN CANCELLED. TEMPS SHOULD CONTINUE TO RISE A COUPLE MORE DEGREES TODAY. THE WINTER STORM WARNING FOR CARBON AND MONROE COUNTIES REMAINS IN EFFECT FOR EXPECTED SNOW LATER TONIGHT AND ON WEDNESDAY. MEANWHILE...RADAR SHOWS THE AREA OF HEAVIEST RAIN NOW WRAPPING WWD ACROSS NRN NJ AND INTO ERN PA. THIS AXIS SHOULD CONTINUE TO SHIFT NWD ALONG WITH THE LOW-LVL STORM CENTER AND BEST EASTERLY INFLOW. THE FLOOD WATCH AREA HAS BEEN ADJUSTED TO REMOVE AREAS FROM PHL SWWD...AND ALSO ADD THE TIER OF COUNTIES OVER FAR NW NJ AND ADJ ERN PA. PREVIOUS DISCUSSION BELOW... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WARNING: HAZARD ON TARGET WITH MDT FLOODING ASSURED AND IT MAY BE A STRONG MODERATE DOWN IN THE CAPE MAY-LEWES AREA. SURGE OF 2 TO POSSIBLY 3 FEET AT HIGH TIDE THIS MORNING. SANDY HOOK LINKED COUNTIES I THINK MAY ESCAPE MDT FLOODING BUT NO CHANGE TO THE WARNING. DEPARTURES AT SANDY HOOK ABOUT A FOOT LESS THAN FURTHER SOUTH WHERE STRONGER INFLOW AND LOWER PRESSURE. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CUT THE SE TIER AT 630 AM AND CHANGED TO HEAVIER ICE ACCUMS THE REMAINING ADVISORY AND ALSO THE WINTER STORM WARNING. STILL SLEET IN SUSSEX COUNTY NJ. WE MAY NEED TO ISSUE NEW ADVISORIES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...IFR TO POSSIBLY LOW-END MVFR IN RAIN OR DRIZZLE, AS MOST OF THE STEADIER MODERATE RAIN WILL CONTINUE LIFTING NORTH OF THE TAF SITES THROUGH THE REST OF THIS MORNING. GUSTY NORTH WINDS TO BETWEEN 20 TO 30 KT ARE EXPECTED, EXCEPT AROUND 35 KT AT TIMES IN VICINITY OF KACY. CONDITIONS SHOULD IMPROVE THIS AFTERNOON AS THE STEADIER RAIN LIFTS NORTH AND WINDS TURN SLIGHTLY MORE NORTH NORTHWEST. GUSTS DIMINISH LATE TODAY. TONIGHT...MVFR CIGS WITH BANDS OF RAIN SHIFTING SOUTHEASTWARD AND RAIN CHANGING TO WET SNOW AT KRDG AND KABE. NORTH TO NORTHWEST WINDS GUST 20 TO 30 KT. OUTLOOK... WEDNESDAY THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... THE FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR FROM PHILLY NORTH. THE SOUTHERN PORTION OF THE WATCH HAS BEEN CANCELLED WITH THE BULK OF THE MODERATE TO HEAVY RAIN PUSHING NORTH. FOUR COUNTIES HAVE BEEN ADDED OF THE NORTHWEST PERIPHERY, LEHIGH NORTHEAST THROUGH SUSSEX AS THE PRECIPITATION HAS BECOME LIQUID. THE HEAVIER RAINS WILL CONTINUE INTO THE MID TO LATE AFTERNOON HOURS BEFORE ENDING. RUNOFF WILL CONTINUE THROUGH THE OVERNIGHT, LONGER IN SOME SPOTS. ANTECEDENT CONDITIONS ARE WET DUE TO THE RAINS THE REGION SAW THIS PAST SATURDAY. THIS IS ALLOWING FOR A MORE EFFICIENT RUNOFF. WHERE IT RAINS THE HEAVIEST, TOTAL RAINFALL ACCUMULATIONS WILL BE IN THE 2 TO 3 INCH RANGE. THERE COULD BE SOME TOTALS OVER 3 INCHES. SMALLER CREEKS AND STREAMS WILL BE THE FIRST BODIES OF WATER TO RESPOND. THEY ALREADY HAVE. THOSE AREAS WHICH DRAIN INTO TIDAL WATERS COULD SEE INCREASED FLOODING (IN THE MINOR CATEGORY) DUE TO HIGHER THAN NORMAL TIDES. ON THE LARGER BODIES OF WATER THAT ARE SUPPORTED BY THE MARFC, THERE ARE ABOUT A DOZEN FORECAST POINTS THAT EXCEED CAUTION/ACTION STAGE, A FEW OF THEM LASTING THROUGH THE NEXT FEW DAYS. THE MAJORITY OF THESE POINT ARE IN NJ. AS FOR GAUGES HITTING FLOOD STAGE, WE WILL KEEP AN EYE ON BLACKWELLS MILLS AND PEMBERTON. IF RUNOFF AND RISES CONTINUE AS EXPECTED INTO THIS AFTERNOON, FLOOD WARNINGS WILL BE ISSUED LATER TODAY. PEMBERTON COULD HIT FLOOD STAGE AS EARLY AS THIS EVENING AND BLACKWELLS MILLS COULD HIT FLOOD STAGE OVERNIGHT TONIGHT. && .TIDES/COASTAL FLOODING... COASTAL FLOOD WARNING CONTINUES AS NOTED IN THE NEAR TERM SECTION. WATER BUILDUP HAS OCCURRED IN ALL OUR TIDAL WATERS DURING THE PAST SEVERAL TIDE CYCLES, INCLUDING THE DELAWARE AND CHESAPEAKE BAYS AND THE DELAWARE RIVER. ANOMALIES THIS MORNING ARE RUNNING BETWEEN 2 AND 2.5 FEET ABOVE NORMAL NORTH OF ATLANTIC CITY, AND 2.5 TO 3 FEET ABOVE NORMAL SOUTH OF ATLANTIC CITY. IN THE DELAWARE BAY, ANOMALIES ARE AROUND 2.5 FEET ABOVE NORMAL, AND IN THE CHESAPEAKE BAY 1 FOOT ABOVE NORMAL. A STRONG ONSHORE FLOW SHOULD MAINTAIN THESE ANOMALIES THROUGH THE HIGH TIDE CYCLE THIS MORNING AND EARLY AFTERNOON. THEN, AS THE COASTAL LOW CONTINUES TO MOVE SLOWLY NORTH, WINDS WILL GRADUALLY SHIFT TO THE NORTH, THEN NORTHWEST, WHICH SHOULD EAT AWAY AT THESE ANOMALIES, PARTICULARLY SOUTH OF ATLANTIC CITY. LOWER ANOMALIES COMBINED WITH A SMALLER ASTRONOMICAL CONTRIBUTION (0.5 TO 1.0 FOOT LOWER) SHOULD KEEP ANY ADDITIONAL TIDAL FLOODING DURING THE NEXT HIGH TIDE CYCLE TONIGHT IN THE MINOR RANGE FROM ATLANTIC CITY SOUTH. SO...MODERATE FLOODING EXPECTED ALONG THE COAST AND ASSOCIATED BACKBAYS WITH THIS MORNINGS HIGH TIDE, MODERATE FLOODING EXPECTED ALONG THE SHORES OF THE LOWER DELAWARE BAY, AND MINOR TO LOW END MODERATE FLOODING EXPECTED ON THE UPPER DELAWARE BAY. MINOR TIDAL FLOODING IS A POSSIBILITY ON THE TIDAL DELAWARE (NORTH OF REEDY POINT, INCLUDING PHILADELPHIA), AND AN ADVISORY MAY BE NEEDED. ELEVATED WATER LEVELS ARE OCCURRING IN THE NORTHERN PORTIONS OF THE CHESAPEAKE BAY, BUT NO FLOODING IS EXPECTED. AS ALWAYS, ROUGH SURF AND HEAVY RAIN AT THE TIME OF HIGH TIDE WILL EXACERBATE THE FLOODING ISSUE. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ061-062-103>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ001-007>010-012>015- 019-020-025>027. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ012>014-020>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR NJZ016. DE...COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ002>004. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR DEZ001. MD...NONE. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ431. && $$ SYNOPSIS...O`HARA NEAR TERM...AMC/DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/KLINE/O`HARA MARINE...DRAG/O`HARA HYDROLOGY...KRUZDLO TIDES/COASTAL FLOODING...MIKETTA CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
954 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THE MID-MORNING UPDATE...THE FORECAST FROM EARLIER THIS MORNING IS BASICALLY ON TRACK BUT HAVE MADE ADJUSTMENTS TO SOME OF THE HAZARDS. AS OF 900 AM TEMPS ACROSS ALL THE FCST AREA SEEM TO HAVE RISEN ABOVE FREEZING AND ALL REPORTED PRECIP IS RAIN...SO THE WINTER WEATHER ADVISORY FOR PARTS OF NW NJ AND ERN PA HAS BEEN CANCELLED. TEMPS SHOULD CONTINUE TO RISE A COUPLE MORE DEGREES TODAY. THE WINTER STORM WARNING FOR CARBON AND MONROE COUNTIES REMAINS IN EFFECT FOR EXPECTED SNOW LATER TONIGHT AND ON WEDNESDAY. MEANWHILE...RADAR SHOWS THE AREA OF HEAVIEST RAIN NOW WRAPPING WWD ACROSS NRN NJ AND INTO ERN PA. THIS AXIS SHOULD CONTINUE TO SHIFT NWD ALONG WITH THE LOW-LVL STORM CENTER AND BEST EASTERLY INFLOW. THE FLOOD WATCH AREA HAS BEEN ADJUSTED TO REMOVE AREAS FROM PHL SWWD...AND ALSO ADD THE TIER OF COUNTIES OVER FAR NW NJ AND ADJ ERN PA. PREVIOUS DISCUSSION BELOW... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WARNING: HAZARD ON TARGET WITH MDT FLOODING ASSURED AND IT MAY BE A STRONG MODERATE DOWN IN THE CAPE MAY-LEWES AREA. SURGE OF 2 TO POSSIBLY 3 FEET AT HIGH TIDE THIS MORNING. SANDY HOOK LINKED COUNTIES I THINK MAY ESCAPE MDT FLOODING BUT NO CHANGE TO THE WARNING. DEPARTURES AT SANDY HOOK ABOUT A FOOT LESS THAN FURTHER SOUTH WHERE STRONGER INFLOW AND LOWER PRESSURE. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CUT THE SE TIER AT 630 AM AND CHANGED TO HEAVIER ICE ACCUMS THE REMAINING ADVISORY AND ALSO THE WINTER STORM WARNING. STILL SLEET IN SUSSEX COUNTY NJ. WE MAY NEED TO ISSUE NEW ADVISORIES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...IFR TO POSSIBLY LOW-END MVFR IN RAIN OR DRIZZLE, AS MOST OF THE STEADIER MODERATE RAIN WILL CONTINUE LIFTING NORTH OF THE TAF SITES THROUGH THE REST OF THIS MORNING. GUSTY NORTH WINDS TO BETWEEN 20 TO 30 KT ARE EXPECTED, EXCEPT AROUND 35 KT AT TIMES IN VICINITY OF KACY. CONDITIONS SHOULD IMPROVE THIS AFTERNOON AS THE STEADIER RAIN LIFTS NORTH AND WINDS TURN SLIGHTLY MORE NORTH NORTHWEST. GUSTS DIMINISH LATE TODAY. TONIGHT...MVFR CIGS WITH BANDS OF RAIN SHIFTING SOUTHEASTWARD AND RAIN CHANGING TO WET SNOW AT KRDG AND KABE. NORTH TO NORTHWEST WINDS GUST 20 TO 30 KT. OUTLOOK... WEDNESDAY THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR ZONES INCLUDING PARTS OF SOUTHERN NEW JERSEY WHERE 1.5 TO POSSIBLY 3 INCHES OF RAIN IS EXPECTED TO FALL THROUGH THIS EVENING. THE RAIN, HEAVY AT TIMES, WILL ADD TO THE ALREADY WET ANTECEDENT CONDITIONS ACROSS THE REGION. THIS WILL ALLOW FOR BETTER RUNOFF INTO AREAS STREAMS AND CREEKS AND SOME OF THE SMALLER RIVERS...THE MAINSTEM RIVERS SHOULD REMAIN WITHIN THEIR BANKS. HEAVIEST APPEARS TO BE NNJ AND COASTAL NJ. SO FAR AS OF 530 AM: MANY REPORTS 1 TO 1.9 INCHES IN CAPE MAY...BURLINGTON AND ATLANTIC COUNTIES SINCE THE RAIN BEGAN AROUND MIDNIGHT. THE MAIN AREA OF DOUBT IS THE SW END OF THE WATCH IN NORTHERN DE WHERE RAINFALL LOOKS TO BE LESS THAN 1.5 INCHES. I COULD SEE THIS PART OF THE WATCH BEING CANCELLED LATER THIS MORNING. && .TIDES/COASTAL FLOODING... COASTAL FLOOD WARNING CONTINUES AS NOTED IN THE NEAR TERM SECTION. WATER BUILDUP HAS OCCURRED IN ALL OUR TIDAL WATERS DURING THE PAST SEVERAL TIDE CYCLES, INCLUDING THE DELAWARE AND CHESAPEAKE BAYS AND THE DELAWARE RIVER. ANOMALIES THIS MORNING ARE RUNNING BETWEEN 2 AND 2.5 FEET ABOVE NORMAL NORTH OF ATLANTIC CITY, AND 2.5 TO 3 FEET ABOVE NORMAL SOUTH OF ATLANTIC CITY. IN THE DELAWARE BAY, ANOMALIES ARE AROUND 2.5 FEET ABOVE NORMAL, AND IN THE CHESAPEAKE BAY 1 FOOT ABOVE NORMAL. A STRONG ONSHORE FLOW SHOULD MAINTAIN THESE ANOMALIES THROUGH THE HIGH TIDE CYCLE THIS MORNING AND EARLY AFTERNOON. THEN, AS THE COASTAL LOW CONTINUES TO MOVE SLOWLY NORTH, WINDS WILL GRADUALLY SHIFT TO THE NORTH, THEN NORTHWEST, WHICH SHOULD EAT AWAY AT THESE ANOMALIES, PARTICULARLY SOUTH OF ATLANTIC CITY. LOWER ANOMALIES COMBINED WITH A SMALLER ASTRONOMICAL CONTRIBUTION (0.5 TO 1.0 FOOT LOWER) SHOULD KEEP ANY ADDITIONAL TIDAL FLOODING DURING THE NEXT HIGH TIDE CYCLE TONIGHT IN THE MINOR RANGE FROM ATLANTIC CITY SOUTH. SO...MODERATE FLOODING EXPECTED ALONG THE COAST AND ASSOCIATED BACKBAYS WITH THIS MORNINGS HIGH TIDE, MODERATE FLOODING EXPECTED ALONG THE SHORES OF THE LOWER DELAWARE BAY, AND MINOR TO LOW END MODERATE FLOODING EXPECTED ON THE UPPER DELAWARE BAY. MINOR TIDAL FLOODING IS A POSSIBILITY ON THE TIDAL DELAWARE (NORTH OF REEDY POINT, INCLUDING PHILADELPHIA), AND AN ADVISORY MAY BE NEEDED. ELEVATED WATER LEVELS ARE OCCURRING IN THE NORTHERN PORTIONS OF THE CHESAPEAKE BAY, BUT NO FLOODING IS EXPECTED. AS ALWAYS, ROUGH SURF AND HEAVY RAIN AT THE TIME OF HIGH TIDE WILL EXACERBATE THE FLOODING ISSUE. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ061-062-103>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ001-007>010-012>015- 019-020-025>027. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ012>014-020>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR NJZ016. DE...COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ002>004. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR DEZ001. MD...NONE. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ431. && $$ SYNOPSIS...O`HARA NEAR TERM...AMC/DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/KLINE/O`HARA MARINE...DRAG/O`HARA HYDROLOGY...DRAG TIDES/COASTAL FLOODING...MIKETTA CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
947 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THE MID-MORNING UPDATE...THE FORECAST FROM EARLIER THIS MORNING IS BASICALLY ON TRACK BUT HAVE MADE ADJUSTMENTS TO SOME OF THE HAZARDS. AS OF 900 AM TEMPS ACROSS ALL THE FCST AREA SEEM TO HAVE RISEN ABOVE FREEZING AND ALL REPORTED PRECIP IS RAIN...SO THE WINTER WEATHER ADVISORY FOR PARTS OF NW NJ AND ERN PA HAS BEEN CANCELLED. TEMPS SHOULD CONTINUE TO RISE A COUPLE MORE DEGREES TODAY. THE WINTER STORM WARNING FOR CARBON AND MONROE COUNTIES REMAINS IN EFFECT FOR EXPECTED SNOW LATER TONIGHT AND ON WEDNESDAY. MEANWHILE...RADAR SHOWS THE AREA OF HEAVIEST RAIN NOW WRAPPING WWD ACROSS NRN NJ AND INTO ERN PA. THIS AXIS SHOULD CONTINUE TO SHIFT NWD ALONG WITH THE LOW-LVL STORM CENTER AND BEST EASTERLY INFLOW. THE FLOOD WATCH AREA HAS BEEN ADJUSTED TO REMOVE AREAS FROM PHL SWWD...AND ALSO ADD THE TIER OF COUNTIES OVER FAR NW NJ AND ADJ ERN PA. PREVIOUS DISCUSSION BELOW... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WARNING: HAZARD ON TARGET WITH MDT FLOODING ASSURED AND IT MAY BE A STRONG MODERATE DOWN IN THE CAPE MAY-LEWES AREA. SURGE OF 2 TO POSSIBLY 3 FEET AT HIGH TIDE THIS MORNING. SANDY HOOK LINKED COUNTIES I THINK MAY ESCAPE MDT FLOODING BUT NO CHANGE TO THE WARNING. DEPARTURES AT SANDY HOOK ABOUT A FOOT LESS THAN FURTHER SOUTH WHERE STRONGER INFLOW AND LOWER PRESSURE. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CUT THE SE TIER AT 630 AM AND CHANGED TO HEAVIER ICE ACCUMS THE REMAINING ADVISORY AND ALSO THE WINTER STORM WARNING. STILL SLEET IN SUSSEX COUNTY NJ. WE MAY NEED TO ISSUE NEW ADVISORIES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...IFR IN RAIN..SOME HEAVY WITH FREEZING RAIN AT KRDG AND KABE FOR A LITTLE WHILE THIS MORNING. GUSTY NORTH WINDS TO 2O TO 30 KT EXCEPT NEAR 40 KT VCNTY KACY. CONDITIONS SHOULD IMPROVE THIS AFTERNOON AS HEAVY RAIN LIFTS NORTH AND WINDS TURN SLIGHTLY MORE NORTH NORTHWEST. GUSTS DIMINISH LATE TODAY. TONIGHT...MVFR CIGS WITH BANDS OF RAIN SHIFTING SOUTHEASTWARD AND RAIN CHANGING TO WET SNOW AT KRDG AND KABE. NORTH TO NORTHWEST WINDS GUST 20 TO 30 KT. OUTLOOK... WEDNESDAY THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR ZONES INCLUDING PARTS OF SOUTHERN NEW JERSEY WHERE 1.5 TO POSSIBLY 3 INCHES OF RAIN IS EXPECTED TO FALL THROUGH THIS EVENING. THE RAIN, HEAVY AT TIMES, WILL ADD TO THE ALREADY WET ANTECEDENT CONDITIONS ACROSS THE REGION. THIS WILL ALLOW FOR BETTER RUNOFF INTO AREAS STREAMS AND CREEKS AND SOME OF THE SMALLER RIVERS...THE MAINSTEM RIVERS SHOULD REMAIN WITHIN THEIR BANKS. HEAVIEST APPEARS TO BE NNJ AND COASTAL NJ. SO FAR AS OF 530 AM: MANY REPORTS 1 TO 1.9 INCHES IN CAPE MAY...BURLINGTON AND ATLANTIC COUNTIES SINCE THE RAIN BEGAN AROUND MIDNIGHT. THE MAIN AREA OF DOUBT IS THE SW END OF THE WATCH IN NORTHERN DE WHERE RAINFALL LOOKS TO BE LESS THAN 1.5 INCHES. I COULD SEE THIS PART OF THE WATCH BEING CANCELLED LATER THIS MORNING. && .TIDES/COASTAL FLOODING... COASTAL FLOOD WARNING CONTINUES AS NOTED IN THE NEAR TERM SECTION. WATER BUILDUP HAS OCCURRED IN ALL OUR TIDAL WATERS DURING THE PAST SEVERAL TIDE CYCLES, INCLUDING THE DELAWARE AND CHESAPEAKE BAYS AND THE DELAWARE RIVER. ANOMALIES THIS MORNING ARE RUNNING BETWEEN 2 AND 2.5 FEET ABOVE NORMAL NORTH OF ATLANTIC CITY, AND 2.5 TO 3 FEET ABOVE NORMAL SOUTH OF ATLANTIC CITY. IN THE DELAWARE BAY, ANOMALIES ARE AROUND 2.5 FEET ABOVE NORMAL, AND IN THE CHESAPEAKE BAY 1 FOOT ABOVE NORMAL. A STRONG ONSHORE FLOW SHOULD MAINTAIN THESE ANOMALIES THROUGH THE HIGH TIDE CYCLE THIS MORNING AND EARLY AFTERNOON. THEN, AS THE COASTAL LOW CONTINUES TO MOVE SLOWLY NORTH, WINDS WILL GRADUALLY SHIFT TO THE NORTH, THEN NORTHWEST, WHICH SHOULD EAT AWAY AT THESE ANOMALIES, PARTICULARLY SOUTH OF ATLANTIC CITY. LOWER ANOMALIES COMBINED WITH A SMALLER ASTRONOMICAL CONTRIBUTION (0.5 TO 1.0 FOOT LOWER) SHOULD KEEP ANY ADDITIONAL TIDAL FLOODING DURING THE NEXT HIGH TIDE CYCLE TONIGHT IN THE MINOR RANGE FROM ATLANTIC CITY SOUTH. SO...MODERATE FLOODING EXPECTED ALONG THE COAST AND ASSOCIATED BACKBAYS WITH THIS MORNINGS HIGH TIDE, MODERATE FLOODING EXPECTED ALONG THE SHORES OF THE LOWER DELAWARE BAY, AND MINOR TO LOW END MODERATE FLOODING EXPECTED ON THE UPPER DELAWARE BAY. MINOR TIDAL FLOODING IS A POSSIBILITY ON THE TIDAL DELAWARE (NORTH OF REEDY POINT, INCLUDING PHILADELPHIA), AND AN ADVISORY MAY BE NEEDED. ELEVATED WATER LEVELS ARE OCCURRING IN THE NORTHERN PORTIONS OF THE CHESAPEAKE BAY, BUT NO FLOODING IS EXPECTED. AS ALWAYS, ROUGH SURF AND HEAVY RAIN AT THE TIME OF HIGH TIDE WILL EXACERBATE THE FLOODING ISSUE. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ061-062-103>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ001-007>010-012>015- 019-020-025>027. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ012>014-020>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR NJZ016. DE...COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ002>004. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR DEZ001. MD...NONE. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ431. && $$ SYNOPSIS...O`HARA NEAR TERM...AMC/DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/O`HARA MARINE...DRAG/O`HARA HYDROLOGY...DRAG TIDES/COASTAL FLOODING...MIKETTA CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
847 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WARNING: HAZARD ON TARGET WITH MDT FLOODING ASSURED AND IT MAY BE A STRONG MODERATE DOWN IN THE CAPE MAY-LEWES AREA. SURGE OF 2 TO POSSIBLY 3 FEET AT HIGH TIDE THIS MORNING. SANDY HOOK LINKED COUNTIES I THINK MAY ESCAPE MDT FLOODING BUT NO CHANGE TO THE WARNING. DEPARTURES AT SANDY HOOK ABOUT A FOOT LESS THAN FURTHER SOUTH WHERE STRONGER INFLOW AND LOWER PRESSURE. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CUT THE SE TIER AT 630 AM AND CHANGED TO HEAVIER ICE ACCUMS THE REMAINING ADVISORY AND ALSO THE WINTER STORM WARNING. STILL SLEET IN SUSSEX COUNTY NJ. WE MAY NEED TO ISSUE NEW ADVISORIES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...IFR IN RAIN..SOME HEAVY WITH FREEZING RAIN AT KRDG AND KABE FOR A LITTLE WHILE THIS MORNING. GUSTY NORTH WINDS TO 2O TO 30 KT EXCEPT NEAR 40 KT VCNTY KACY. CONDITIONS SHOULD IMPROVE THIS AFTERNOON AS HEAVY RAIN LIFTS NORTH AND WINDS TURN SLIGHTLY MORE NORTH NORTHWEST. GUSTS DIMINISH LATE TODAY. TONIGHT...MVFR CIGS WITH BANDS OF RAIN SHIFTING SOUTHEASTWARD AND RAIN CHANGING TO WET SNOW AT KRDG AND KABE. NORTH TO NORTHWEST WINDS GUST 20 TO 30 KT. OUTLOOK... WEDNESDAY THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR ZONES INCLUDING PARTS OF SOUTHERN NEW JERSEY WHERE 1.5 TO POSSIBLY 3 INCHES OF RAIN IS EXPECTED TO FALL THROUGH THIS EVENING. THE RAIN, HEAVY AT TIMES, WILL ADD TO THE ALREADY WET ANTECEDENT CONDITIONS ACROSS THE REGION. THIS WILL ALLOW FOR BETTER RUNOFF INTO AREAS STREAMS AND CREEKS AND SOME OF THE SMALLER RIVERS...THE MAINSTEM RIVERS SHOULD REMAIN WITHIN THEIR BANKS. HEAVIEST APPEARS TO BE NNJ AND COASTAL NJ. SO FAR AS OF 530 AM: MANY REPORTS 1 TO 1.9 INCHES IN CAPE MAY...BURLINGTON AND ATLANTIC COUNTIES SINCE THE RAIN BEGAN AROUND MIDNIGHT. THE MAIN AREA OF DOUBT IS THE SW END OF THE WATCH IN NORTHERN DE WHERE RAINFALL LOOKS TO BE LESS THAN 1.5 INCHES. I COULD SEE THIS PART OF THE WATCH BEING CANCELLED LATER THIS MORNING. && .TIDES/COASTAL FLOODING... COASTAL FLOOD WARNING CONTINUES AS NOTED IN THE NEAR TERM SECTION. WATER BUILDUP HAS OCCURRED IN ALL OUR TIDAL WATERS DURING THE PAST SEVERAL TIDE CYCLES, INCLUDING THE DELAWARE AND CHESAPEAKE BAYS AND THE DELAWARE RIVER. ANOMALIES THIS MORNING ARE RUNNING BETWEEN 2 AND 2.5 FEET ABOVE NORMAL NORTH OF ATLANTIC CITY, AND 2.5 TO 3 FEET ABOVE NORMAL SOUTH OF ATLANTIC CITY. IN THE DELAWARE BAY, ANOMALIES ARE AROUND 2.5 FEET ABOVE NORMAL, AND IN THE CHESAPEAKE BAY 1 FOOT ABOVE NORMAL. A STRONG ONSHORE FLOW SHOULD MAINTAIN THESE ANOMALIES THROUGH THE HIGH TIDE CYCLE THIS MORNING AND EARLY AFTERNOON. THEN, AS THE COASTAL LOW CONTINUES TO MOVE SLOWLY NORTH, WINDS WILL GRADUALLY SHIFT TO THE NORTH, THEN NORTHWEST, WHICH SHOULD EAT AWAY AT THESE ANOMALIES, PARTICULARLY SOUTH OF ATLANTIC CITY. LOWER ANOMALIES COMBINED WITH A SMALLER ASTRONOMICAL CONTRIBUTION (0.5 TO 1.0 FOOT LOWER) SHOULD KEEP ANY ADDITIONAL TIDAL FLOODING DURING THE NEXT HIGH TIDE CYCLE TONIGHT IN THE MINOR RANGE FROM ATLANTIC CITY SOUTH. SO...MODERATE FLOODING EXPECTED ALONG THE COAST AND ASSOCIATED BACKBAYS WITH THIS MORNINGS HIGH TIDE, MODERATE FLOODING EXPECTED ALONG THE SHORES OF THE LOWER DELAWARE BAY, AND MINOR TO LOW END MODERATE FLOODING EXPECTED ON THE UPPER DELAWARE BAY. MINOR TIDAL FLOODING IS A POSSIBILITY ON THE TIDAL DELAWARE (NORTH OF REEDY POINT, INCLUDING PHILADELPHIA), AND AN ADVISORY MAY BE NEEDED. ELEVATED WATER LEVELS ARE OCCURRING IN THE NORTHERN PORTIONS OF THE CHESAPEAKE BAY, BUT NO FLOODING IS EXPECTED. AS ALWAYS, ROUGH SURF AND HEAVY RAIN AT THE TIME OF HIGH TIDE WILL EXACERBATE THE FLOODING ISSUE. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ070-071-101>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ060>062. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ008>010-012>020-022- 025>027. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ012>014-020>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR NJZ016. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR NJZ001-007. DE...FLOOD WATCH THROUGH LATE TONIGHT FOR DEZ001. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ002>004. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR DEZ001. MD...FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ008. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ431. && $$ SYNOPSIS...O`HARA NEAR TERM...DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/O`HARA MARINE...DRAG/O`HARA HYDROLOGY...DRAG TIDES/COASTAL FLOODING...MIKETA CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
652 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WATCH: HAZARD ON TARGET WITH MDT FLOODING ASSURED AND IT MAY BE A STRONG MODERATE DOWN IN THE CAPE MAY-LEWES AREA. SURGE OF 2 TO POSSIBLY 3 FEET AT HIGH TIDE THIS MORNING. SANDY HOOK LINKED COUNTIES I THINK MAY ESCAPE MDT FLOODING BUT NO CHANGE TO THE WARNING. DEPARTURES AT SANDY HOOK ABOUT A FOOT LESS THAN FURTHER SOUTH WHERE STRONGER INFLOW AND LOWER PRESSURE. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CUT THE SE TIER AT 630 AM AND CHANGED TO HEAVIER ICE ACCUMS THE REMAINING ADVISORY AND ALSO THE WINTER STORM WARNING. STILL SLEET IN SUSSEX COUNTY NJ. WE MAY NEED TO ISSUE NEW ADVISORIES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...IFR IN RAIN..SOME HEAVY WITH FREEZING RAIN AT KRDG AND KABE FOR A LITTLE WHILE THIS MORNING. GUSTY NORTH WINDS TO 2O TO 30 KT EXCEPT NEAR 40 KT VCNTY KACY. CONDITIONS SHOULD IMPROVE THIS AFTERNOON AS HEAVY RAIN LIFTS NORTH AND WINDS TURN SLIGHTLY MORE NORTH NORTHWEST. GUSTS DIMINISH LATE TODAY. TONIGHT...MVFR CIGS WITH BANDS OF RAIN SHIFTING SOUTHEASTWARD AND RAIN CHANGING TO WET SNOW AT KRDG AND KABE. NORTH TO NORTHWEST WINDS GUST 20 TO 30 KT. OUTLOOK... WEDNESDAY THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR ZONES INCLUDING PARTS OF SOUTHERN NEW JERSEY WHERE 1.5 TO POSSIBLY 3 INCHES OF RAIN IS EXPECTED TO FALL THROUGH THIS EVENING. THE RAIN, HEAVY AT TIMES, WILL ADD TO THE ALREADY WET ANTECEDENT CONDITIONS ACROSS THE REGION. THIS WILL ALLOW FOR BETTER RUNOFF INTO AREAS STREAMS AND CREEKS AND SOME OF THE SMALLER RIVERS...THE MAINSTEM RIVERS SHOULD REMAIN WITHIN THEIR BANKS. HEAVIEST APPEARS TO BE NNJ AND COASTAL NJ. SO FAR AS OF 530 AM: MANY REPORTS 1 TO 1.9 INCHES IN CAPE MAY...BURLINGTON AND ATLANTIC COUNTIES SINCE THE RAIN BEGAN AROUND MIDNIGHT. THE MAIN AREA OF DOUBT IS THE SW END OF THE WATCH IN NORTHERN DE WHERE RAINFALL LOOKS TO BE LESS THAN 1.5 INCHES. I COULD SEE THIS PART OF THE WATCH BEING CANCELLED LATER THIS MORNING. && .TIDES/COASTAL FLOODING... COASTAL FLOOD WARNING CONTINUES AS NOTED IN THE NEAR TERM SECTION. NOT SURE IF WE WILL REACH ADVISORY CRITERIA UPPER DE BAY BUT CONTINUING THE HEADLINE. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ070-071-101>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ060>062. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ008>010-012>020-022- 025>027. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ012>014-020>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 3 PM EST THIS AFTERNOON FOR NJZ016. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR NJZ001-007. DE...FLOOD WATCH THROUGH LATE TONIGHT FOR DEZ001. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ002>004. COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 3 PM EST THIS AFTERNOON FOR DEZ001. MD...FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ008. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ431. && $$ SYNOPSIS...O`HARA NEAR TERM...DRAG 652A SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/O`HARA MARINE...DRAG/O`HARA HYDROLOGY... TIDES/COASTAL FLOODING... CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
539 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WATCH: HAZARD ON TARGET WITH MDT FLOODING ASSURED AND IT MAY BE A STRONG MODERATE DOWN IN THE CAPE MAY-LEWES AREA. SURGE OF 2 TO POSSIBLY 3 FEET AT HIGH TIDE THIS MORNING. SANDY HOOK LINKED COUNTIES I THINK MAY ESCAPE MDT FLOODING BUT NO CHANGE TO THE WARNING. DEPARTURES AT SANDY HOOK ABOUT A FOOT LESS THAN FURTHER SOUTH WHERE STRONGER INFLOW AND LOWER PRESSURE. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CONTINUE AS DESCRIBED. AT 630AM WILL DROP THE SE TIER OF COUNTIES. WE MAY NEED TO ISSUE NEW ONES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...IFR IN RAIN..SOME HEAVY WITH FREEZING RAIN AT KRDG AND KABE FOR A LITTLE WHILE THIS MORNING. GUSTY NORTH WINDS TO 2O TO 30 KT EXCEPT NEAR 40 KT VCNTY KACY. CONDITIONS SHOULD IMPROVE THIS AFTERNOON AS HEAVY RAIN LIFTS NORTH AND WINDS TURN SLIGHTLY MORE NORTH NORTHWEST. GUSTS DIMINISH LATE TODAY. TONIGHT...MVFR CIGS WITH BANDS OF RAIN SHIFTING SOUTHEASTWARD AND RAIN CHANGING TO WET SNOW AT KRDG AND KABE. NORTH TO NORTHWEST WINDS GUST 20 TO 30 KT. OUTLOOK... WEDNESDAY THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR ZONES INCLUDING PARTS OF SOUTHERN NEW JERSEY WHERE 1.5 TO POSSIBLY 3 INCHES OF RAIN IS EXPECTED TO FALL THROUGH THIS EVENING. THE RAIN, HEAVY AT TIMES, WILL ADD TO THE ALREADY WET ANTECEDENT CONDITIONS ACROSS THE REGION. THIS WILL ALLOW FOR BETTER RUNOFF INTO AREAS STREAMS AND CREEKS AND SOME OF THE SMALLER RIVERS...THE MAINSTEM RIVERS SHOULD REMAIN WITHIN THEIR BANKS. HEAVIEST APPEARS TO BE NNJ AND COASTAL NJ. SO FAR AS OF 530 AM: MANY REPORTS 1 TO 1.9 INCHES IN CAPE MAY...BURLINGTON AND ATLANTIC COUNTIES SINCE THE RAIN BEGAN AROUND MIDNIGHT. THE MAIN AREA OF DOUBT IS THE SW END OF THE WATCH IN NORTHERN DE WHERE RAINFALL LOOKS TO BE LESS THAN 1.5 INCHES. I COULD SEE THIS PART OF THE WATCH BEING CANCELLED LATER THIS MORNING. && .TIDES/COASTAL FLOODING... COASTAL FLOOD WARNING CONTINUES AS NOTED IN THE NEAR TERM SECTION. NOT SURE IF WE WILL REACH ADVISORY CRITERIA UPPER DE BAY BUT CONTINUING THE HEADLINE. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ070-071-101>106. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ101>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ060>062. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ008>010-012>020-022- 025>027. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NJZ008>010-015. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ012>014-020>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 3 PM EST THIS AFTERNOON FOR NJZ016. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR NJZ001-007. DE...FLOOD WATCH THROUGH LATE TONIGHT FOR DEZ001. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ002>004. COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 3 PM EST THIS AFTERNOON FOR DEZ001. MD...FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ008. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ431. && $$ SYNOPSIS...O`HARA NEAR TERM...DRAG 539 SHORT TERM...DRAG 539 LONG TERM...O`HARA AVIATION...DRAG/O`HARA 539 MARINE...DRAG/O`HARA HYDROLOGY...539 TIDES/COASTAL FLOODING...539 CLIMATE...
AREA FORECAST DISCUSSION
NWS DES MOINES IA
536 AM CST TUE DEC 9 2014 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 301 AM CST TUE DEC 9 2014 CLOUD COVER AND TEMPS WERE THE FOCUS AS THE SURFACE HIGH SLOWLY BUILDS INTO THE STATE THROUGHOUT THE DAY TODAY. CAA CONTINUES THIS MORNING AND FINALLY DIMINISHES BY THE EARLY AFTERNOON. LOW LEVEL MOISTURE LOOKS TO POTENTIALLY REMAIN TRAPPED UNDER THE INVERSION SETTING UP AROUND 925M THROUGH THE DAY. THIS WOULD SUGGEST LOW STRATUS DECK TO LINGER INTO THE AFTERNOON AND INCREASED SKY COVER DURING THIS TIME TO REFLECT THIS TREND. THE 09.06Z HRRR AND 09.03Z HOPWRF HINTING ON CLOUD COVER LASTING THROUGH THE AFTERNOON HOURS TODAY AS WELL. TEMPS SHOULD STRUGGLE TO INCREASE MUCH TODAY WITH THE STRATUS AND CAA PERSISTING FOR MUCH OF THE DAY. LOWERED MAX TEMPS ACROSS THE NORTH AND WEST A DEGREE BUT LEFT THE REMAINDER OF THE FORECAST WITH PREVIOUS FORECAST AS IT LOOKED ON TRACK. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 301 AM CST TUE DEC 9 2014 OVERALL...THE MID TO LATE WEEK PATTERN WILL FEATURE A PERIOD OF INCREASED WARMING AND MOISTURE. SUBJECTIVE H850 ANALYSIS TONIGHT SHOWS UPPER LEVEL LOW AND COLD AIR ADVECTION OVER THE REGION...WITH THE GREAT LAKES WAVE SUPPRESSING MOISTURE TO THE FAR SOUTHERN STATES. HIGH PRESSURE ALOFT OVER THE SOUTHERN PLAINS IS ALREADY SUPPORTING RETURN FLOW OVER THE RED RIVER VALLEY INTO NEW MEXICO. MODELS SHOW THAT THIS PLUME WILL GRADUALLY MOVE NORTHWEST THEN NORTHEAST INTO THE CENTRAL PLAINS BY MID TO LATE WEEK...AND THROUGH THE WEEKEND. THOUGH THE PATTERN REMAINS FAIRLY QUIET INTO THE EARLY WEEKEND...THE RETURN OF MOISTURE AND LOW STRATUS ALONG WITH DRIZZLE OR LIGHT RAIN POTENTIAL WILL BE THE MAIN CHALLENGES IN THE NEXT 5 DAYS. FOR TONIGHT...A WEAK WAVE CURRENTLY OVER MONTANA WILL DROP SOUTHEAST INTO THE NORTHWEST FLOW AND BRING WITH IT ANOTHER AREA OF MID LEVEL CLOUDS TO THE REGION LATE THIS EVENING AND OVERNIGHT. WEAK WARM AIR ADVECTION WILL ACCOMPANY THE SYSTEM...ALLOWING TEMPERATURES OVERNIGHT TO REMAIN SIMILAR TO EARLY THIS MORNINGS LOWS. CLOUDS WILL PASS THROUGH THE AREA AGAIN WEDNESDAY NIGHT AND THURSDAY WITH CONTINUED WARM AIR ADVECTION AND MOISTURE ADVECTION ON THE BACK SIDE OF THE RIDGE. ONCE AGAIN WITH TONIGHTS RUN...THE NAM IS FASTER WITH SATURATION AT LOWER LEVELS WHILE THE GFS INITIALLY WED NIGHT AND THURSDAY MORNING DOES NOT SHOW SATURATION...BUT LATER IN THE DAY THURSDAY INTO THURSDAY NIGHT/FRIDAY. HAVE OPTED TO MAINTAIN A DRY FORECAST FOR NOW. BUFR SOUNDINGS SHOW MORE WIDESPREAD CLOUDS THURSDAY INTO FRIDAY...WHICH MAY IMPACT MINS AND ESPECIALLY HIGHS BOTH DAYS. FOR NOW...HAVE TRIMMED FRI HIGHS A BIT OVER THE AREA BACK DOWN INTO THE MID TO UPPER 40S CENTRAL TO LOWER 50S WEST/SOUTH. BY SATURDAY SOUTHWEST FLOW WILL PERSIST ACROSS THE ENTIRE REGION WITH READINGS INTO THE LOWER TO MID 50S OVER MOST OF THE SOUTH...UPPER 40S NORTHEAST. STRATUS WILL STILL BE PREVALENT ACROSS THE AREA...BUT MIXING MIGHT PROMOTE SOME BREAKS IN CLOUD COVER. DIFFUSE WARM AIR ADVECTION ALOFT MAY BE ENOUGH TO PRODUCE A FEW LIGHT SHOWERS AS WELL...ESPECIALLY LATER IN THE AFTERNOON WEST INTO SATURDAY NIGHT. MODELS CONTINUE TO SHOW A MORE PRONOUNCED WAVE BY DAYS 6 AND 7 WITH A LEE SIDE TROUGH DEEPENING OVER THE SOUTHERN PLAINS. THE MODELS STILL DIVERGE ON SOLUTIONS WITH THE GFS FARTHER NORTH AND PHASING THE TWO STREAMS WHILE THE EURO IS MORE PROGRESSIVE BUT DOES ALSO ALLOW FOR A RAIN SNOW MIX BY MONDAY. GIVEN THE UNCERTAINTY...WILL MAINTAIN A BLENDED APPROACH UNTIL DETAILS BECOME MORE APPARENT. AFTER A MILD WEEKEND...PASSAGE OF SYSTEM MONDAY WILL USHER IN COOLER TEMPERATURES FOR EARLY NEXT WEEK. && .AVIATION...09/12Z ISSUED AT 533 AM CST TUE DEC 9 2014 MVFR STRATUS WILL PERSIST THROUGH MUCH OF THE DAY TODAY AND INTO TONIGHT. LOW CONFIDENCE WITH THE STRATUS BREAKING UP ANYTIME TODAY AND KEPT MENTION OF IT THROUGH ENTIRE TAF PERIOD. THE LOW LEVEL MOISTURE TRAPPED UNDER THE INVERSION IS FAIRLY SHALLOW...SO IT SHOULD BE A THIN ENOUGH TO SEE SUN SHINNING THROUGH. OTHERWISE...POSSIBLE FOG DEVELOPING TOWARDS WEDNESDAY MORNING BUT LEFT OUT MENTION ATTM TIME DUE TO UNCERTAINTY OF STRATUS DEPARTURE. HOPWRF/HRRR LATEST MODEL RUNS KEEP THE STRATUS THROUGHOUT THE AFTERNOON TODAY. THERE IS A COUPLE OF VFR HOLES IN THE STRATUS DECK...BUT SHOULD QUICKLY FILL BACK IN WITH THE CAA. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
654 AM CST TUE DEC 9 2014 ...UPDATED AVIATION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM CST TUE DEC 9 2014 HIGH LEVEL CLOUD COVER WILL BE LIKELY TODAY ACROSS THE CENTRAL HIGH PLAINS AS A COLD FRONT STALLS OUT IN EXTREME SOUTHWEST KANSAS BY LATE MORNING. CONFIDENCE IS NOT HIGH ON HOW DENSE THESE CLOUDS WILL BE BUT NAM, GFS, AND RAP ALL INDICATE A COOLING TREND IN THE 925MB TO 850MB LEVEL FROM 00Z TUESDAY TO 00Z WEDNESDAY. GIVEN THIS COOLING TREND, MORE CLOUDS TODAY COMPARED TO YESTERDAY, AND AN EASTERLY WIND WILL STAY CLOSE TO THE PREVIOUS FORECAST FOR HIGHS THIS AFTERNOON. TEMPERATURES CLIMBING INTO THE UPPER 50S TO NEAR 60 STILL LOOKS REASONABLE IN EXTREME SOUTHWEST KANSAS WHICH WILL BE NEAR/SOUTH OF THE COLD FRONT WHILE HIGHS ONLY IN THE MID 40S IN NORTH CENTRAL KANSAS. EXACTLY HOW THE GRADIENT WILL END UP BETWEEN THESE TWO EXTREMES IS UNCLEAR. ISENTROPIC AND MOISTURE ADVECTION WILL IMPROVE ACROSS WESTERN KANSAS IN THE 900MB TO 800MB LEVEL. STATUS ALONG WITH POSSIBLY SOME AREAS OF FOG APPEARING LIKELY AS THE LOWER LEVELS SATURATE OVERNIGHT. DEPTH OF THIS MOIST LAYER WILL BE IN THE 2000 TO 3000 FT AGL RANGE DEPENDING ON WHICH MODEL SOUNDING YOU EXAMINE. GIVEN THE DEPTH OF THIS LAYER AM TRENDING AWAY FROM INTRODUCING DRIZZLE LATE TONIGHT BUT IF THE NAM ENDS UP BEING MORE CORRECT THEN SOME PATCHY DRIZZLE COULD DEVELOP TOWARDS DAYBREAK. TEMPERATURES ARE EXPECTED TO FALL TO AROUND 32 DEGREES BUT GIVEN THE INCREASE IN LOW LEVEL MOISTURE FORECAST OVERNIGHT THE LOWS MAY OCCUR EARLY WITH TEMPERATURES THEN HOLDING NEARLY STEADY OR EVEN RISE A FEW DEGREES AFTER MIDNIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 358 AM CST TUE DEC 9 2014 THE PERIOD BETWEEN WEDNESDAY AND SATURDAY WILL BE A TRUE CHALLENGE WITH RESPECT TO SKY COVER AND RESULTING TEMPERATURES BOTH IN THE DAYTIME FOR HIGHS AS WELL AS LOWS OVERNIGHT. RELATIVELY MORE MOIST CONDITIONS IN THE BOUNDARY LAYER MARKED BY DEW POINTS IN THE UPPER 30S AND 40S COULD CONTRIBUTE TO EVENING/NIGHT FOG DEVELOPMENT IN ADDITION TO ALREADY EXPECTED STRATUS. STRATUS THAT DOES ERODE DURING THE DAY SHOULD BE ABLE RAPIDLY REDEVELOP ACROSS MUCH OF CENTRAL KANSAS INTO THE EVENING AS THE BOUNDARY LAYER COOLS DIURNALLY. MODELS SOUNDINGS GENERALLY LIMIT THE THICKNESS TO SLIGHTLY MORE THAN 2000 FT, WHICH IS NOT FAVORABLE FOR DRIZZLE DESPITE MODEL QPF OUTPUT. THE PRIMARY CHALLENGE WILL BE DETERMINING HOW FAR WEST THE STRATUS IMPACTS THE FORECAST AREA EACH DAY AND IT`S EFFECT ON TEMPERATURES. WEDNESDAY INTO THURSDAY NIGHT APPEARS LIKELY TO BRING THE MOST WIDESPREAD OVERCAST CONDITIONS, WHILE THE WESTERN MOST COUNTIES, GENERALLY WEST OF HIGHWAY 83 WILL EXPERIENCE THE MOST HOURS OF INSOLATION AND CLEAR SKIES DURING THIS TIMEFRAME. UNLESS THE MODELS SIGNIFICANTLY DIVERGE IN SOLUTIONS FROM THE CURRENT AND RECENT RUNS, SUNDAY NIGHT (OR AROUND THAT SYNOPTIC TIMESCALE/TIMEFRAME) LOOKS WET WITH RAIN POTENTIAL OR EVEN SNOW WITH AS UPPER DYNAMIC LOW PRESSURE MOVING THROUGH OR JUST SOUTH OF THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 649 AM CST TUE DEC 9 2014 RELATIVELY HIGH DEW POINT DEPRESSIONS BEHIND THE SURFACE COLD FRONT WILL PRECLUDE ANY FOG DEVELOPMENT THIS MORNING, PROMOTING VFR CATEGORIES AT THE LOCAL TERMINALS. SURFACE WIND WILL VEER SOUTHERLY THROUGH THE DAY AS SURFACE HIGH PRESSURE OVER THE NORTHERN PLAINS MOVES INTO THE MISSISSPPI VALLEY. && .PRELIMINARY POINT TEMPS/POPS... DDC 49 33 47 41 / 0 10 10 10 GCK 52 31 50 37 / 0 10 0 0 EHA 59 34 57 35 / 0 0 0 0 LBL 56 36 56 44 / 0 10 0 0 HYS 42 29 43 38 / 0 10 10 10 P28 49 31 46 41 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...RUSSELL AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
310 AM MST TUE DEC 9 2014 .UPDATE... ISSUED AT 925 PM MST MON DEC 8 2014 HAVE ISSUED A DENSE FOG ADVISORY FOR AREAS GENERALLY EAST OF A LINE FROM TRENTON TO BREWSTER TO RUSSELL SPRINGS. 03Z RUC SIMILAR TO LATEST HRRR OUTPUT AND 00Z NAM BOOSTING CONFIDENCE THAT DENSE FOG WILL DEVELOP. UPDATE ISSUED AT 745 PM MST MON DEC 8 2014 UPDATES REQUIRED FOR FIRST AND SECOND PERIODS (TONIGHT AND TUESDAY) FOCUSING ON ARRIVAL OF POTENTIALLY DENSE FOG AND LOWER TEMPERATURES THEN PREVIOUSLY FORECAST. AT 0230Z CIRRUS SHIELD THAT WAS OVER THE AREA MOST OF THE DAY IS MOVING EAST AND SLOWLY OUT OF THE AREA. AM EXPECTING MORE TO MOVE IN LATER IN THE EVENING AND THROUGH THE DAY TOMORROW FROM THE NORTHWEST. AT THE SFC STRATUS PER SATELLITE OBS AND RUC 900MB RH FORECAST CURRENTLY OVER NORTHEAST NEBRASKA/SOUTHWEST IOWA. BY 06Z THIS NARROW CORRIDOR OF STRATUS FORECAST TO POSSIBLY REACH AREAS JUST TO THE NORTHEAST FROM MCCOOK TO NORTON. AS SFC HIGH CONTINUES TO BACK INTO THE AREA WITH LIGHT NORTHEAST WINDS STRATUS DECK EXPECTED TO REACH A TRENTON TO HILL CITY LINE BY 09Z THEN ROUGHLY A BENKELMAN TO COLBY AND OAKLEY LINE BY 12Z. IN THE TRENTON TO HILL CITY AND POINTS NORTHEAST AREAS WINDS ARE CALM AND RH NEAR 100 PERCENT. LATEST RUC/HRRR/NAM VISIBILITY FORECASTS ALL SHOWING DENSE FOG WITH VISIBILITIES 1/4 MILE OR LESS. NAM EXTRAPOLATION OF SATURATED BOUNDARY LAYER RH PUSHES IT FURTHER WEST TOWARD THE CO/KS BORDER WITH DENSE FOG CONTINUING ROUGHLY FROM TRENTON TO HOXIE AND POINTS EAST. HRRR SUGGESTS FURTHER WEST TOWARD BENKELMAN TO NEAR GOODLAND AND RUSSELL SPRINGS. WILL AWAIT THE 03Z RUC/LATEST HRRR BEFORE ZONE UPDATE SENT BUT HAVE TRENDED TOWARD ABOVE THINKING. && .SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY) ISSUED AT 119 PM MST MON DEC 8 2014 DECENT AFTERNOON ACROSS THE ENTIRE FORECAST AREA...AS THE TRI STATE REGION IS SEEING TEMPERATURES 15 TO 20 DEGREES ABOVE NORMAL WITH READINGS WELL INTO THE 50S. THIS IS ONGOING DESPITE HIGH CLOUDS MOVING OVER THE AREA CREATING SUNNY CONDITIONS. HIGH CLOUD COVER WILL SCATTER OUT DURING THE EARLY EVENING HOURS IN TIME FOR 925MB THERMAL BOUNDARY/SURFACE RIDGE AXIS COMBO...WHICH MODELS BRING OVER THE REGION BY MIDNIGHT TONIGHT. MODEL RH IN LATEST BUFKIT RUNS DOES HINT AT FOG/LOW STRATUS FORMATION BETWEEN 06Z-14Z TUESDAY...WITH BEST CHANCES OVER IN CENTRAL AND EASTERN ZONES. LGT/VAR WIND CONDITIONS WILL ALSO AID IN FOG FORMATION IN THE AFOREMENTIONED ZONES...SO WILL KEEP PREVIOUS MENTION OF FOG IN THE FORECAST. GOING INTO TUESDAY...SURFACE HIGH PRESSURE SETTLES OVER CENTRAL AND EASTERN PLAINS. THIS IS GOING TO SET UP YET ANOTHER NICE DAY FOR MUCH OF THE CWA. MUCH OF THE WESTERN CWA WILL SEE WAA AGAIN ON SOUTHERLY FLOW...WHILE EASTERN ZONES WILL BE CLOSE ENOUGH TO SURFACE RIDGE THAT WINDS WILL NOT BE MAJOR FACTOR...SO HAVE TAPERED HIGHS FOR TOMORROW FROM WEST TO EAST...MID 50S WEST DOWN TO THE MID 40S ACROSS EASTERN PORTIONS. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 310 AM MST TUE DEC 9 2014 APOLOGIZE FOR THE DELAYED ISSUANCE OF THIS DISCUSSION. ANOTHER DAY...ANOTHER HUGE SWING IN THE FORECAST GUIDANCE...MAINLY WITH REGARDS TO THE STRONG WEATHER SYSTEM THIS WEEKEND/EARLY NEXT WEEK. MAIN DISCUSSION FOCUS IS ON A POTENTIAL SIGNIFICANT HIGH PLAINS WINTER STORM. ONLY THING OF NOTE FOR FRIDAY THROUGH SATURDAY IS THAT GUIDANCE WARMED TEMPS AGAIN FRIDAY...ESPECIALLY OVER THE WESTERN FORECAST AREA. MADE A SMALL ADJUSTMENT TO INCREASE HIGHS. TIME FOR THE MORE IMPORTANT DETAILS. FIRST...THE METEOROLOGY ASPECT OF THIS SCENARIO. LATEST FORECAST GUIDANCE ON ALL ACCOUNTS HAS SHOWN A MAJOR SHIFT IN THIS STORM SYSTEMS EVOLUTION. PREVIOUSLY...ALL... AND I MEAN LITERALLY ALL...FORECAST GUIDANCE INDICATED A LARGE UPPER LEVEL TROUGH DIGGING INTO THE SOUTHWESTERN UNITED STATES SATURDAY... EJECTING OVER TEXAS SUNDAY AND SLOWLY PROGRESSING ON AN EASTERLY COURSE NEXT WEEK. FOR THE LATEST 00Z MODEL RUNS...THE SCENARIO REMAINS THE SAME UNTIL SUNDAY...THE DAY OF MOST CONCERN. MODELS NOW INDICATE THAT A VIGOROUS SHORTWAVE TROUGH LEADS TO INTENSE LEE-SIDE CYCLOGENESIS BY SUNDAY MORNING AND A STRONG...DEEPENING VERTICALLY STACKED SYSTEM SLOWLY PROGRESSES NORTHEAST INTO THE HIGH PLAINS BY SUNDAY NIGHT. THIS DEEP CYCLONE THEN HEADS SOMEWHERE EAST/NORTHEAST AS MODEL GUIDANCE IS NOT IN GREAT AGREEMENT BEYOND MONDAY. LATEST ENSEMBLE MEANS SUPPORT THE OPERATIONAL GFS...EUROPEAN AND CANADIAN MODEL SCENARIOS OF A DEEP CYCLONE. HOWEVER...THERE REMAIN LARGE DIFFERENCES IN TIMING/MOVEMENT. WHAT IS ASSURED IS THERE WILL BE A VIGOROUS MID-LATITUDE CYCLONE MOVING ACROSS THE PLAINS SUNDAY/MONDAY. THERE ARE SOME OTHER COMPLICATING FACTORS THAT COULD PLAY LARGE ROLES THAT NEED TO BE RESOLVED. FIRST IS THE MOISTURE AVAILABILITY. THERE ARE CONCERNS THAT WIDESPREAD THUNDERSTORM ACTIVITY OVER TEXAS AND OKLAHOMA COULD CUT OFF MOISTURE ADVECTION TO THE HIGH PLAINS. HOWEVER...THERE WILL BE 3-4 DAYS OF STRONG GULF MOISTURE ADVECTION PRECEDING THIS SYSTEM. WHILE MOISTURE REINFORCEMENT MAY BE CUT OFF BY SOUTHERN THUNDERSTORM ACTIVITY...FEEL THAT THERE WILL BE SUFFICIENT MOISTURE. FORECAST GUIDANCE INDICATES THAT THE ICE CRYSTAL GROWTH ZONE SATURATES AS THE MAIN PRECIPITATION PASSES THROUGH WHICH FAVORS POTENTIAL SNOW. THE SECOND DRIVING FORCE IS TIMING OF THE NEEDED COLD TEMPERATURES. A STRONG COLD FRONT SHOULD BE THROUGH AT LEAST PARTS OF THE REGION BY SUNDAY MORNING PRECEDING ANY PRECIPITATION DEVELOPMENT. THE COLD FRONT LOOKS TO BE COMPLETELY THROUGH BY LATE SUNDAY MORNING. THEREFORE...THERE WOULD BE NO TEMPERATURE CONCERNS BASED ON CURRENT GUIDANCE FOR THIS POTENTIAL WINTER SYSTEM. SO...WHAT DOES THIS ALL MEAN? WHILE CONFIDENCE IS NOT HIGH DUE TO EXTREME RUN-TO-RUN GUIDANCE VARIABILITY...THERE IS AN INCREASED POTENTIAL FOR A MAJOR WINTER STORM TO STRIKE THE REGION. HERE ARE THE POSSIBILITIES AS THEY STAND NOW: 1. THE BEST CASE SCENARIO IS THAT THE SYSTEM REMAINS WELL TO THE SOUTH AND RESULTS IN ONLY COOLER TEMPERATURES WITH GUSTY WINDS ON SUNDAY. THIS WOULD MEAN THAT THIS LATEST SUITE OF GUIDANCE WAS COMPLETELY OUT TO LUNCH AND THE PREVIOUS RUNS WERE RIGHT. 2. THE MORE LIKELY CASE...AND I SAY THAT WITH A GRAIN OF SALT...IS THAT THIS SYSTEM PASSES JUST SOUTH OF THE FORECAST AREA. THIS RESULTS IN PRECIPITATION DEVELOPING TO THE SOUTHWEST AND SPREADING IN SUNDAY MORNING. COOLING TEMPS WOULD MEAN THAT THE MAIN PRECIP TYPE IS SNOW BUT A PERIOD OF LIGHT RAIN/DRIZZLE IS POSSIBLE BEFORE TEMPS DROP AND ICE CRYSTAL GROWTH ZONE SATURATES. THE WORST OF THE WEATHER BYPASSES US TO THE SOUTH. GUSTY WINDS BEHIND THE FRONT MAY LEAD TO SOME BLOWING SNOW. 3. THE WORST CASE SCENARIO IS BASICALLY WHAT ALL LATEST OPERATIONAL MODEL RUNS HIGHLIGHT. A STRONG LOW PASSES JUST SOUTH OF THE REGION. A LARGE SWATH OF PRECIPITATION DEVELOPS ON THE LOW`S NORTHWEST SIDE...PASSING DIRECTLY OVER THE FORECAST AREA. DEPENDING ON THE TIMING OF THE COLD FRONT...A BRIEF PERIOD OF RAIN MAY OCCUR SUNDAY MORNING BEFORE PRECIPITATION CHANGES TO SNOW BY SUNDAY AFTERNOON. A LARGE AMOUNT OF PRECIPITATION IS INDICATED AND WOULD LIKELY FALL IN THE FORM OF SNOW. GUSTY NORTH WINDS PRODUCE BLOWING/DRIFTING SNOW. IN THIS SCENARIO...A CRIPPLING WINTER STORM IS POSSIBLE. WHILE THIS SCENARIO IS QUITE WORRISOME...IT IS TOUGH TO COMPLETELY SUPPORT THIS SCENARIO AS WHAT WILL HAPPEN SINCE THIS IS THE FIRST RUN WHERE MOST GUIDANCE SUGGESTS AN INTENSE WINTER STORM WILL HAPPEN. AFTER ALL OF THIS...WHAT DO YOU NEED TO KNOW? AGAIN...A SIGNIFICANT WINTER STORM IS POSSIBLE ON SUNDAY/MONDAY. HOWEVER...CONFIDENCE IS QUITE LOW ON THE EVOLUTION AND IMPACTS OF THIS SYSTEM. FUTURE FORECAST UPDATES MUST BE MONITORED FOR THE LATEST INFORMATION ON THIS INCOMING SYSTEM. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1000 PM MST MON DEC 8 2014 KGLD...VFR THROUGH 12Z WITH WINDS UNDER 5KTS AND A FEW HIGH CLOUDS. A FEW STRATUS CLOUDS MAY BE SEEN EAST OF THE TERMINAL AROUND 12Z-13Z BECOMING BKN OVER THE TERMINAL WITH SOME BR AND REDUCED VISIBILITIES IN THE 14Z-16Z TIME FRAME. IFR CONDITIONS ARE EXPECTED. UNDER A SCATTERED TO BROKEN LAYER OF CIRRUS FROM 19Z THROUGH 04Z WINDS GENERALLY FROM THE SOUTH TO SOUTHEAST AROUND 11KTS VEERING TO THE SOUTHWEST AROUND 7KTS FROM 05Z-06Z. KMCK...VFR THROUGH 09Z WITH WINDS UNDER 5KTS AND A FEW HIGH CLOUDS. FROM 09Z THROUGH 18Z VLIFR CIGS/VIS EXPECTED TO MOVE IN FROM THE NORTHEAST WITH LIGHT/VARIABLE WINDS. AROUND 19Z THROUGH THE REST OF THE TAF PERIOD STRATUS EXPECTED TO THIN OUT ENOUGH TO PRODUCE VFR CONDITIONS WITH ONLY A LAYER OF CIRRUS AND SOUTHEAST/EAST-SOUTHEAST WINDS AROUND 5KTS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...DENSE FOG ADVISORY UNTIL 11 AM CST THIS MORNING FOR KSZ002>004- 014>016-028-029. CO...NONE. NE...DENSE FOG ADVISORY UNTIL 10 AM MST /11 AM CST/ THIS MORNING FOR NEZ079>081. && $$ UPDATE...99 SHORT TERM...JN LONG TERM...RRH AVIATION...99
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
631 AM EST TUE DEC 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 512 AM EST TUE DEC 9 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF EXTENDING FROM HUDSON BAY S THRU THE OHIO VALLEY. WITH TROF AXIS NOW E OF UPPER MI... HEIGHTS ARE BEGINNING TO RISE AS BROAD RIDGE OVER WRN NAMERICA EXPANDS EASTWARD. AT THE SFC...TROF IS ALSO NOW S AND E OF UPPER MI WITH BRISK N TO NW WINDS USHERING IN SOMEWHAT COLDER AIR INTO THE AREA...MOST NOTICEABLE BLO 850MB. WITH ABUNDANT LOW-LEVEL MOISTURE PER UPSTREAM 00Z KINL/CWPL SOUNDINGS...LOW CLOUDS ARE WIDESPREAD OVER THE UPPER LAKES WITH CLEARING ONLY NOTED OVER PORTIONS OF NRN AND WRN LAKE SUPERIOR IN THE DOWNSLOPE AREAS OFF ONTARIO AND MN NSHORE. TEMPS IN THE SHALLOW MOIST LAYER HAVE BEEN FALLING...BUT APPARENTLY AREN`T COLD ENOUGH YET TO ENSURE COMPLETE ICE NUCLEATION AS -SN HAS BEEN MIXED AT TIMES WITH -FZDZ DURING THE NIGHT IN THE UPSLOPE FLOW OFF LAKE SUPERIOR. LATEST RUC/NAM FCST SOUNDINGS SHOW TEMPS IN THE MOIST LAYER NEARING -10C...SO ANY LINGERING -FZDZ SHOULD BE ENDING IN THE NEXT FEW HRS. A FEW HRS AGO...ONLY ONE HEAVIER BAND OF SNOW WAS NOTED OFF SCNTRL LAKE SUPERIOR INTO THE MARQUETTE AREA AND ERN MARQUETTE COUNTY. CURRENTLY...RADAR DOES NOT SHOW ANYTHING OTHER THAN VERY LIGHT PCPN STREAMERS. LINGERING -SHSN/FLURRIES WILL WIND DOWN TODAY AS INVERSION FALLS TO 2-3KFT AHEAD OF A 1035-1040MB HIGH PRES RIDGE DRIFTING SE TOWARD THE UPPER LAKES. WITH THE ABUNDANT LOW-LEVEL MOISTURE NOTED OVER THE REGION UNDER INVERSION...OPTED TOWARD A MUCH MORE PESSIMISTIC CLOUD FCST TODAY. CLOUDS WILL BE MOST RELUCTANT TO BREAK IN THE AREAS WHERE N TO NE FLOW IS UPSLOPING. BREAKING OF THE CLOUDS MAY BE MORE LIKELY OVER THE FAR E LATER IN THE DAY AS VEERING WINDS INCREASE DOWNSLOPING OFF ONTARIO. MAY SEE A SIMILAR SITUATION NEAR LAKE SUPERIOR OVER THE FAR W LATE AS DOWNSLOPING BEGINS WITH WINDS VEERING MORE EASTERLY. CLOUDS/SHALLOW CAA WILL KEEP TEMPS FROM RISING MUCH DURING THE DAY. SFC HIGH PRES RIDGE AXIS WILL SETTLE OVER UPPER MI/LAKE SUPERIOR TONIGHT. WHILE FAVORABLE FOR A GOOD RADIATIONAL COOLING NIGHT... THERE IS HUGE BUST POTENTIAL WITH TEMPS DUE TO UNCERTAINTY IN CLOUD COVER. BEST BET FOR CLEARING IS IN TWO AREAS. CLEARING SHOULD EXPAND WESTWARD THRU ERN UPPER MI FROM THE DOWNSLOPING OFF ONTARIO UNDER E TO NE FLOW...AND CLEARING WILL ALSO EXPAND NEAR LAKE SUPERIOR OVER WRN UPPER MI AS WINDS BECOME DOWNSLOPING E TO SE. NCNTRL UPPER MI INTO THE KEWEENAW WILL LIKELY SEE MOST PERSISTENT CLOUD COVER TONIGHT AS WINDS MAINTAIN SOME UPSLOPE COMPONENT ALL NIGHT. FOR NOW...INDICATED MIN TEMPS INTO THE SINGLE DIGITS WHERE AT LEAST SOME CLEARING IS EXPECTED. IF SKIES CLEAR...TRADITIONAL COLD SPOTS WILL FALL TO NEAR OR PERHAPS BLO 0F. IF CLOUDS HOLD...TEENS WILL LIKELY BE THE RULE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 346 AM EST TUE DEC 9 2014 AN UPPER RIDGE WILL BUILD OVER THE CWA THROUGH SAT AS A SFC RIDGE SITS OVER THE CWA BEFORE MOVING SE FRI INTO SAT. THIS WILL KEEP CONDITIONS ON THE QUIET SIDE WITH NO PRECIP EXPECTED THROUGH 00Z SUN. WED NIGHT LOOKS TO BE THE COLDEST NIGHT WITH SINGLE DIGIT ABOVE ZERO LOWS INLAND AS THE RIDGE WILL BE OVERHEAD AND THE SIGNIFICANTLY WARMER AIRMASS IS STILL TO THE W. 850MB TEMPS WILL BE ON THE RISE FROM AOB 0C AT 12Z WED TO AOA 10C BY 00Z SAT...WITH THE WARMER TEMPS STICKING AROUND THROUGH SAT. WARMEST TEMPS EXPECTED ON SAT WITH HIGHS FROM THE UPPER 30S TO LOW 40S. WHILE THERE IS A LOT OF UNCERTAINTY WITH THE TRANSITION INTO A MORE ACTIVE PATTER LATE IN THE WEEKEND...IT DOES LOOK LIKE SOME LIGHT PRECIP IS POSSIBLE SOMETIME SUN INTO MON...AND PTYPE WILL TRANSITION BACK TO SNOW AT LEAST OVER PORTIONS OF THE AREA BY MON. LOTS WILL DEPEND ON THE TRACK/STRENGTH OF UPPER LEVEL ENERGY WHICH MODELS VARY SUBSTANTIALLY FROM RUN TO RUN. STILL NOT BUYING GREATER QPF/LOW LEVEL MOISTURE THAT MODELS SHOW ON SUN/SUN NIGHT AS MODELS LIKELY ARE OVERDOING LOW LEVEL MOISTURE AS THEY OFTEN DO WHEN MODELING SNOWPACK MELTING. REMOVED ANY MENTION OF FREEZING RAIN FOR SAT NIGHT-MON SINCE SFC TEMPS WILL BE TOO WARM FOR FREEZING RAIN IF THE RAIN/CLOUDS ARE AS THICK AS MODELS SUGGEST...AND IF THERE IS LESS LOW LEVEL MOISTURE TEMPS WILL BE COLDER BUT PRECIPITATION PROBABLY WILL NOT OCCUR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 631 AM EST TUE DEC 9 2014 ABUNDANT LOW-LEVEL MOISTURE TRAPPED UNDER FALLING SUBSIDENCE INVERSION WILL SET THE STAGE FOR A CHALLENGING FCST. INITIALLY... UPSLOPE FLOW OFF LAKE SUPERIOR WILL CONTINUE TO SUPPORT PREVAILING LIFR CIGS AT KIWD/KCMX/KSAW FOR MUCH OF THE MORNING. EXPECT SLOW IMPROVEMENT TO IFR...THEN LOW MVFR DURING THE AFTN AS SLIGHT DRYING OCCURS IN THE LOW-LEVELS. AS DOWNSLOPING BEGINS AT KIWD WITH LOW-LEVEL WINDS VEERING TO LIGHT E TO SE THIS EVENING...LOW MVFR CIGS SHOULD SCATTER OUT. CLEARING SHOULD ALSO PROGRESS W THRU ERN UPPER MI...AND IT`S POSSIBLE LOW MVFR CIGS COULD SCATTER OUT AT KSAW LATE TONIGHT. WITH MOSTLY A LIGHT UPSLOPE FLOW CONTINUING AT KCMX... LOW MVFR CIGS MAY PERSIST THRU THE NIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 512 AM EST TUE DEC 9 2014 BEHIND A LOW PRES TROF...N TO NW WINDS RAMPED UP TO 20-30KT OVERNIGHT WITH A FEW GALE FORCE GUSTS NOTED OVER CNTRL LAKE SUPERIOR. AS HIGH PRES RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY APPROACHES TODAY...WINDS WILL DIMINISH FROM W TO E TO UNDER 20KT BY EVENING. WITH THE HIGH PRES RIDGE THEN SETTLING OVER THE UPPER LAKES TONIGHT THRU WED...WINDS WILL DROP OFF TO UNDER 15KT. WINDS WILL INCREASE SLIGHTLY THU AND FRI...BUT WILL REMAIN UNDER 20KT. THESE LIGHTER WINDS MAY LINGER ON INTO SAT AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EST TUE DEC 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 512 AM EST TUE DEC 9 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF EXTENDING FROM HUDSON BAY S THRU THE OHIO VALLEY. WITH TROF AXIS NOW E OF UPPER MI... HEIGHTS ARE BEGINNING TO RISE AS BROAD RIDGE OVER WRN NAMERICA EXPANDS EASTWARD. AT THE SFC...TROF IS ALSO NOW S AND E OF UPPER MI WITH BRISK N TO NW WINDS USHERING IN SOMEWHAT COLDER AIR INTO THE AREA...MOST NOTICEABLE BLO 850MB. WITH ABUNDANT LOW-LEVEL MOISTURE PER UPSTREAM 00Z KINL/CWPL SOUNDINGS...LOW CLOUDS ARE WIDESPREAD OVER THE UPPER LAKES WITH CLEARING ONLY NOTED OVER PORTIONS OF NRN AND WRN LAKE SUPERIOR IN THE DOWNSLOPE AREAS OFF ONTARIO AND MN NSHORE. TEMPS IN THE SHALLOW MOIST LAYER HAVE BEEN FALLING...BUT APPARENTLY AREN`T COLD ENOUGH YET TO ENSURE COMPLETE ICE NUCLEATION AS -SN HAS BEEN MIXED AT TIMES WITH -FZDZ DURING THE NIGHT IN THE UPSLOPE FLOW OFF LAKE SUPERIOR. LATEST RUC/NAM FCST SOUNDINGS SHOW TEMPS IN THE MOIST LAYER NEARING -10C...SO ANY LINGERING -FZDZ SHOULD BE ENDING IN THE NEXT FEW HRS. A FEW HRS AGO...ONLY ONE HEAVIER BAND OF SNOW WAS NOTED OFF SCNTRL LAKE SUPERIOR INTO THE MARQUETTE AREA AND ERN MARQUETTE COUNTY. CURRENTLY...RADAR DOES NOT SHOW ANYTHING OTHER THAN VERY LIGHT PCPN STREAMERS. LINGERING -SHSN/FLURRIES WILL WIND DOWN TODAY AS INVERSION FALLS TO 2-3KFT AHEAD OF A 1035-1040MB HIGH PRES RIDGE DRIFTING SE TOWARD THE UPPER LAKES. WITH THE ABUNDANT LOW-LEVEL MOISTURE NOTED OVER THE REGION UNDER INVERSION...OPTED TOWARD A MUCH MORE PESSIMISTIC CLOUD FCST TODAY. CLOUDS WILL BE MOST RELUCTANT TO BREAK IN THE AREAS WHERE N TO NE FLOW IS UPSLOPING. BREAKING OF THE CLOUDS MAY BE MORE LIKELY OVER THE FAR E LATER IN THE DAY AS VEERING WINDS INCREASE DOWNSLOPING OFF ONTARIO. MAY SEE A SIMILAR SITUATION NEAR LAKE SUPERIOR OVER THE FAR W LATE AS DOWNSLOPING BEGINS WITH WINDS VEERING MORE EASTERLY. CLOUDS/SHALLOW CAA WILL KEEP TEMPS FROM RISING MUCH DURING THE DAY. SFC HIGH PRES RIDGE AXIS WILL SETTLE OVER UPPER MI/LAKE SUPERIOR TONIGHT. WHILE FAVORABLE FOR A GOOD RADIATIONAL COOLING NIGHT... THERE IS HUGE BUST POTENTIAL WITH TEMPS DUE TO UNCERTAINTY IN CLOUD COVER. BEST BET FOR CLEARING IS IN TWO AREAS. CLEARING SHOULD EXPAND WESTWARD THRU ERN UPPER MI FROM THE DOWNSLOPING OFF ONTARIO UNDER E TO NE FLOW...AND CLEARING WILL ALSO EXPAND NEAR LAKE SUPERIOR OVER WRN UPPER MI AS WINDS BECOME DOWNSLOPING E TO SE. NCNTRL UPPER MI INTO THE KEWEENAW WILL LIKELY SEE MOST PERSISTENT CLOUD COVER TONIGHT AS WINDS MAINTAIN SOME UPSLOPE COMPONENT ALL NIGHT. FOR NOW...INDICATED MIN TEMPS INTO THE SINGLE DIGITS WHERE AT LEAST SOME CLEARING IS EXPECTED. IF SKIES CLEAR...TRADITIONAL COLD SPOTS WILL FALL TO NEAR OR PERHAPS BLO 0F. IF CLOUDS HOLD...TEENS WILL LIKELY BE THE RULE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 346 AM EST TUE DEC 9 2014 AN UPPER RIDGE WILL BUILD OVER THE CWA THROUGH SAT AS A SFC RIDGE SITS OVER THE CWA BEFORE MOVING SE FRI INTO SAT. THIS WILL KEEP CONDITIONS ON THE QUIET SIDE WITH NO PRECIP EXPECTED THROUGH 00Z SUN. WED NIGHT LOOKS TO BE THE COLDEST NIGHT WITH SINGLE DIGIT ABOVE ZERO LOWS INLAND AS THE RIDGE WILL BE OVERHEAD AND THE SIGNIFICANTLY WARMER AIRMASS IS STILL TO THE W. 850MB TEMPS WILL BE ON THE RISE FROM AOB 0C AT 12Z WED TO AOA 10C BY 00Z SAT...WITH THE WARMER TEMPS STICKING AROUND THROUGH SAT. WARMEST TEMPS EXPECTED ON SAT WITH HIGHS FROM THE UPPER 30S TO LOW 40S. WHILE THERE IS A LOT OF UNCERTAINTY WITH THE TRANSITION INTO A MORE ACTIVE PATTER LATE IN THE WEEKEND...IT DOES LOOK LIKE SOME LIGHT PRECIP IS POSSIBLE SOMETIME SUN INTO MON...AND PTYPE WILL TRANSITION BACK TO SNOW AT LEAST OVER PORTIONS OF THE AREA BY MON. LOTS WILL DEPEND ON THE TRACK/STRENGTH OF UPPER LEVEL ENERGY WHICH MODELS VARY SUBSTANTIALLY FROM RUN TO RUN. STILL NOT BUYING GREATER QPF/LOW LEVEL MOISTURE THAT MODELS SHOW ON SUN/SUN NIGHT AS MODELS LIKELY ARE OVERDOING LOW LEVEL MOISTURE AS THEY OFTEN DO WHEN MODELING SNOWPACK MELTING. REMOVED ANY MENTION OF FREEZING RAIN FOR SAT NIGHT-MON SINCE SFC TEMPS WILL BE TOO WARM FOR FREEZING RAIN IF THE RAIN/CLOUDS ARE AS THICK AS MODELS SUGGEST...AND IF THERE IS LESS LOW LEVEL MOISTURE TEMPS WILL BE COLDER BUT PRECIPITATION PROBABLY WILL NOT OCCUR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1242 AM EST TUE DEC 9 2014 LOW-LEVEL MOISTURE IN THE WAKE OF LOW PRESSURE MOVING OVER EASTERN UPR MICHIGAN IS COMBINING WITH UPSLOPE FLOW TO MAINTAIN LIFR/IFR CIGS AT ALL THE TAF SITES. EXPECT MVFR OR IFR VSBY OVERNIGHT WITH SOME LGT SNOW SHOWERS OR EVEN DZ/FZDZ. IMPROVEMENT EXPECTED AT KCMX LATE IN THE NIGHT AS UPSLOPING DIMINISHES. ADDITIONAL IMPROVEMENT WILL OCCUR AT ALL THE TAF SITES TODAY BUT BKN-OVC MVFR CIGS SHOULD REMAIN IN PLACE INTO THE EVENING AS MOISTURE REMAINS TRAPPED BENEATH INVERSION. HOWEVER...SKIES SHOULD AT LEAST PARTIALLY CLEAR OUT AT KIWD BY AFTN AS DOWNSLOPING EAST FLOW DEVELOPS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 512 AM EST TUE DEC 9 2014 BEHIND A LOW PRES TROF...N TO NW WINDS RAMPED UP TO 20-30KT OVERNIGHT WITH A FEW GALE FORCE GUSTS NOTED OVER CNTRL LAKE SUPERIOR. AS HIGH PRES RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY APPROACHES TODAY...WINDS WILL DIMINISH FROM W TO E TO UNDER 20KT BY EVENING. WITH THE HIGH PRES RIDGE THEN SETTLING OVER THE UPPER LAKES TONIGHT THRU WED...WINDS WILL DROP OFF TO UNDER 15KT. WINDS WILL INCREASE SLIGHTLY THU AND FRI...BUT WILL REMAIN UNDER 20KT. THESE LIGHTER WINDS MAY LINGER ON INTO SAT AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...JLA MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
518 AM CST Tue Dec 9 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 315 AM CST Tue Dec 9 2014 Vort max which dropped across the region overnight is now working its way into the TN valley, with associated cold front currently dropping into far s counties of our CWA. Early morning 11-3.9 low cloud imagery indicates an extensive area of ST and SC in the wake of the front, with this low cloud deck extending into the upper Mississippi Valley and upper Great Lakes with only a few minor breaks noted. While can`t rule out a bit of sunshine, believe clouds will dominate much of the region today due to the extensive low level moisture trapped beneath a fairly stout inversion, as suggested by 925mb RH progs from both the RUC and NAM. Today will certainly be cooler than yesterday, and I`ve attempted to try to limit diurnal swing as clouds should definitely inhibit a big daytime temp swing. However, if a solid cloud deck holds throughout the day going max temps may still be a bit too warm. Truett .LONG TERM: (Tonight through Monday) Issued at 315 AM CST Tue Dec 9 2014 (Tonight-Thursday) Chilly and tranquil weather should continue during this time frame, and the primary forecast concern is how short-term low cloud trends will evolve heading into midweek. Given forecast inversion and north-northeast low level flow forecast across the area as surface ridge works into the upper Mississippi Valley, believe low clouds will hold over the region tonight and will likely have a tendency to hang tough through Wednesday, with some additional mid level cloudiness spilling into the area as strong but moisture-starved shortwave zips down the back side of the large upper level low winding up over the east coast. Temperatures should moderate a bit by Thursday with a slightly warmer airmass and a bit more sunshine. (Friday-Monday) Medium range solutions take eastern U.S. low up the eastern seaboard heading into the end of the week, allowing upper level ridge to work into the central CONUS. Resultant warming of the AMS over the mid-Mississippi Valley should provide a strong rebound in temps across the FA, with highs in the 50s by the end of the week. UA pattern over the CONUS becomes even more progressive by late in the period, allowing aforementioned ridge to push east and deep UA trof over the western U.S. to sweep into the Plains. This could mean some precip in our CWA by Sunday, with better chances by the start of the new work week. This system should be a rain-maker for our area due to the relatively mild AMS. Truett && .AVIATION: (For the 12z TAFs through 12z Wednesday Morning) Issued at 515 AM CST Tue Dec 9 2014 MVFR stratus has returned to the region in the wake of the cold front and is expected to hang around through mid-week. Can`t rule out ceiling dropping into IFR range, but not confident enought to include in forecast at this time. North wind will become light as surface high moves closer. Specifics for KSTL: MVFR stratus expected with north wind becoming light and variable tonight. CVKING && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
557 AM CST TUE DEC 9 2014 .SYNOPSIS... ISSUED AT 358 AM CST TUE DEC 9 2014 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A DECENT UPPER LEVEL DISTURBANCE OVER NRN ILLINOIS WITH A TROUGH EXTENDING SWD TO THE FLORIDA PANHANDLE. FURTHER WEST...A BROAD RIDGE EXTENDED FROM THE INTERMOUNTAIN WEST NORTH INTO THE YUKON OF CANADA. WITHIN THIS RIDGE...A DISTURBANCE WAS NOTED OVER WESTERN MONTANA. CURRENT WV IMAGERY AS OF 2 AM CST HAS THIS FEATURE NOW OVER EASTERN PORTIONS OF MT. AT THE SURFACE...AN ELONGATED AREA OF HIGH PRESSURE EXTENDED ACROSS THE EASTERN DAKOTAS INTO EASTERN NEBRASKA. FURTHER WEST...A TROUGH OF LOW PRESSURE WAS PRESENT OVER EASTERN WYOMING INTO NORTHERN COLORADO. AN AREA OF STRATUS AND FOG HAS DEVELOPED ON THE WESTERN PERIPHERY OF THE HIGH OVERNIGHT...AND THIS AREA OF CLOUDS AND FOG EXTENDED FROM NORTH CENTRAL NEBRASKA INTO CENTRAL AND PORTIONS OF SWRN NEBRASKA. THE FOG WAS PRIMARILY ALONG THE WESTERN EDGE OF THE STRATUS/LOW CLOUDS AND ROUGHLY EXTENDED FROM VALENTINE TO AINSWORTH...SWD TO THEDFORD...NORTH PLATTE AND BROKEN BOW. FURTHER WEST...SOME HIGH CLOUDS WERE MOVING INTO THE NEBRASKA PANHANDLE AND FAR WESTERN PORTIONS OF THE FORECAST AREA ATTM. UNDER MOSTLY CLOUDY SKIES...TEMPERATURES AS OF 3 AM CST...RANGED FROM 15 AT NORTH PLATTE TO 25 AT BROKEN BOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CST TUE DEC 9 2014 TODAY AND TONIGHT...THE FORECAST CHALLENGES OVER THE NEXT 24 HOURS...ARE TEMPERATURES TODAY...AS WELL AS FOG POTENTIAL THIS MORNING...AS WELL AS TONIGHT. FOR TODAY...AS MENTIONED ABOVE...FOG HAS DEVELOPED ALONG THE HIGHWAY 83 CORRIDOR...AS WELL AS ALONG A LINE FROM AINSWORTH TO BROKEN BOW. ATTM...THE LATEST HI RES RUC SOLN HAS THIS AREA OF FOG EXPANDING SLIGHTLY TO THE SOUTHWEST TOWARD DAYBREAK. ONE WILDCARD IN THE DEGREE OF WESTWARD DEVELOPMENT OF FOG...IS THE POTENTIAL IMPACT OF HIGH LEVEL CLOUDINESS MOVING IN FROM THE WEST. ATTM...FOG VISBYS HAVE BEEN GENERALLY IN THE 1 TO 5 MILE RANGE...SO WILL KEEP FOG MENTION AS PATCHY THIS MORNING. BASED ON THE HRRR SOLN...FOG SHOULD BEGIN TO DISSIPATE DURING THE MID TO LATE MORNING TIME FRAME...AND HAVE EXTENDED THIS MENTION OF FOG INTO THE LATE MORNING HOURS GIVEN THIS MODEL TREND. HIGH PRESSURE WILL BEGIN TO TRACK EAST LATER TODAY INCREASING SRLY WINDS DURING THE AFTERNOON HOURS. FOR LOCATIONS GENERALLY WEST OF HIGHWAY 61...THE WIND DIRECTION WILL TAKE ON A WESTERLY COMPONENT...RESULTING IN SOME LIMITED DOWNSLOPE AND WARMER HIGHS IN THE LOWER 50S. FURTHER EAST...THE COMBINATION OF CLOUDS...SOUTHERLY AND SOUTHEASTERLY WINDS ON THE BACK SIDE OF THE EXITING HIGH...WILL LIMIT HIGHS IN THE UPPER 30S IN THE FAR NORTHEAST...TO THE 40S ALONG THE HIGHWAY 83 CORRIDOR. THE LATEST MAV GUIDANCE HAS TRENDED COLDER FOR HIGHS OVER THE PAST 3 RUNS...AND HAS COME INTO BETTER AGREEMENT WITH THE COLDER MET GUIDANCE. WITH THIS IN MIND...TRENDED HIGHS TDY SOME 2 TO 4 DEGREES COLDER THAN THE INHERITED FCST. FOR TONIGHT...LIGHT SRLY WINDS WILL CONTINUE...PARTICULARLY IN THE EASTERN CWA. THE LATEST NAM SOLN IS INDICATING NEAR SATURATION IN THE BOUNDARY LAYER OVERNIGHT TONIGHT...ROUGHLY EAST OF A LINE FROM CURTIS...TO ONEILL. INHERITED FCST HAD A MENTION OF PATCHY FOG OVERNIGHT IN THESE AREAS AND IT WILL BE CONTINUED WITH THE CURRENT FCST PACKAGE. OVERNIGHT LOWS WILL BE IN THE LOWER 20S...WITH SOME UPPER TEENS IN THE PLATTE RIVER VALLEY GIVEN THE EXPECTED LIGHT WINDS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 358 AM CST TUE DEC 9 2014 12Z WEDNESDAY AND BEYOND...MODELS REMAIN IN GOOD AGREEMENT THAT AMPLIFIED UPPER RIDGING OVER THE CENTRAL CONUS WILL EVENTUALLY BREAK DOWN/FORCED EAST AS A LONG WAVE TROUGH DIGS INTO THE WESTERN STATES AND EVENTUALLY THE PLAINS. TEMPERATURES UNDER THE RIDGE WILL REMAIN ABOVE AVERAGE...AND SHOULD WARM BY SEVERAL DEGREES EACH DAY. HIGHS BY FRIDAY ARE ANTICIPATED TO REACH INTO THE 50S TO LOWER 60S FOR MOST AREAS...POSSIBLY WARMER IF GREATER MIXING OCCURS. SOUTHERLY WINDS WILL HELP INCREASE LOWER LEVEL MOISTURE WHICH COULD PROVIDE FOR PATCHY FOG EACH MORNING...WEDNESDAY THROUGH SATURDAY. THE DETERMINISTIC SOLUTIONS GENERATE LIGHT DZ/QPF ACROSS PORTIONS OF OUR EAST THURSDAY...FRIDAY...AND SATURDAY...BUT THE MOISTURE PROFILES ONLY FAVOR STRATUS AND/OR FOG AS THE DEPTH OF THE RETURN IS RATHER SHALLOW. CONCERNING THIS WEEKEND AND A POTENTIAL SYSTEM...WHAT A DIFFERENCE A DAY MAKES. IN 24 HOURS THE GFS SOLUTION HAS TRENDED NORTH WITH THE TRACK OF THIS WEEKENDS CLOSED H5 LOW BY HUNDREDS OF MILES. THE MODEL GENERATED TRACK OF THE LOW YESTERDAY FAVORED THE BIG BEND OF TEXAS ON SUNDAY...THEREAFTER TRACKING THE LOW OVER HEART OF TEXAS THROUGH EARLY NEXT WEEK. TONIGHT...THE GFS IS FAVORING A SOLUTION WHICH CLOSES OFF A LOW OVER NORTHERN NEW MEXICO...THEN TRACKING THE LOW ACROSS THE PANHANDLES OF TEXAS AND OKLAHOMA...AND EVENTUALLY TOWARD THE MID-MISSOURI VALLEY. IT SHOULD BE NOTED THAT THE MODEL INDICATES THE MEAN TROUGH TAKING A NEGATIVE TILT AS IT EMERGES ON THE PLAINS. COMPLICATING MATTERS...THE EUROPEAN CAMP AND NUMEROUS GFS ENSEMBLES SUPPORT A SIMILAR TRACK INTO THE CENTRAL PLAINS /AT LEAST INITIALLY/. SO FOR THE FIRST SUITE OF RUNS PROGGING THIS SYSTEM...MODEL TO MODEL CONSISTENCY IS SHOWING SOME COHERENCE...BUT RUN TO RUN CONSISTENCY IS SEVERELY LACKING. CONFIDENCE IN ANY ONE PARTICULAR SOLUTION IS LOW...ESPECIALLY SINCE ALL LONG TERM GUIDANCE GENERATES CONVECTION ACROSS THE SOUTHERN PLAINS AND TEXAS ON SUNDAY. THE GFS SEEMS TO BE KEYING ON THE CONVECTIVE POTENTIAL...GENERATING AN AREA OF PV DESTRUCTION OVER OUR SOUTH...AND SEVERELY LIMITING THE QPF POTENTIAL ACROSS MUCH THE CWA. THE GFS HOWEVER DOES EVENTUALLY GENERATE WRAP AROUND QPF SUNDAY AFTERNOON/EVENING ACROSS OUR SOUTH AND EAST. THE WRAP AROUND IS IN QUESTION AS THE CONVECTION /PROJECTED TO BE OVER EASTERN KANSAS/ WOULD ALLOW FOR AN ASSUMED GREATER EASTWARD WOBBLE OF THE H7 LOW. SO INSTEAD OF THE MODEL PROJECTED H7 LOW OVER NORTH CENTRAL KANSAS...THE MORE LIKELY LOCATION WOULD BE EASTERN OR SOUTHEASTERN KANSAS. THE WRAP AROUND WOULD THUS BE SHUNTED SOUTHEAST AS WELL. THE ECMWF IS CONCERNING...GENERATING SIGNIFICANT SNOW ACROSS OUR SOUTHERN TIER ON SUNDAY...BUT AGAIN...THE CONVECTION THAT THE MODEL IS GENERATING PUTS ANY OF THE QPF ACROSS OUR CWA SEVERELY IN QUESTION. THE CR-INT PROCEDURE REMAINS PESSIMISTIC IN THE QPF DEPARTMENT FOR SUNDAY AND BEYOND...WHICH IS FAVORED AT THIS POINT...NO CHANGES WERE MADE TO THE BLENDED FORECAST. BUT...LAST NIGHT MY FORECAST STATED THE POTENTIAL WEEKEND STORM WAS LOOKING MORE LIKE A "DUD" FOR THE CWA...AT THIS TIME I WISH TO RETRACT THOSE WORDS AND STATE THAT THIS SYSTEM IS CERTAINLY WORTH WATCHING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 556 AM CST TUE DEC 9 2014 FOR THIS MORNING...PATCHY FOG IS LIKELY ALONG THE HIGHWAY 83 CORRIDOR FROM KLBF TO KVTN THROUGH THE LATE MORNING HOURS. AT THE KVTN TERMINAL...VISBYS MAY DROP TO 1/2SM THROUGH 14Z THIS MORNING...WITH VISBYS AROUND 3 SM POSSIBLE FROM 14 TO 16Z THIS MORNING. SKIES WILL GRADUALLY CLEAR DURING THE AFTERNOON HOURS...WITH MAINLY CLEAR SKIES PERSISTING THROUGH 12Z WEDNESDAY MORNING. FOR THE KLBF TERMINAL...PATCHY FOG IS POSSIBLE THROUGH MID MORNING WITH VISBYS AS LOW AS 2SM. SOME SCATTERED HIGH CLOUDS POSSIBLE DURING THE AFTERNOON HOURS WITH CLEARING THEREAFTER. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...JACOBS AVIATION...CLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
514 AM CST TUE DEC 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CST TUE DEC 9 2014 SYNOPTIC ANALYSIS OVERNIGHT INDICATES THE UPPER LEVEL TROUGH CONTINUING TO SHIFT ACROSS THE OHIO RIVER VALLEY WHILE AN UPPER LEVEL RIDGE HAS BEGUN TO BUILD ACROSS THE ROCKY MOUNTAINS. ALOFT...A 100+ KT JET CAN BE SEEN DIVING SOUTH ACROSS IOWA AND WESTERN MISSOURI AROUND THE BASE OF THE TROUGH. IN THE MID LEVELS...HEIGHT RISES SUGGEST THE BUILDING OF THE MID LEVEL RIDGE ACROSS THE MIDWEST...AND SOME MINIMAL MID LEVEL MOISTURE PRESENT ACROSS THE PLAINS. AT THE SURFACE...LOW PRESSURE CAN BE SEEN ACROSS THE GREAT LAKES WHILE A LARGE AREA OF HIGH PRESSURE BEGINS TO SPREAD FROM MANITOBA STRETCHING SOUTH INTO NEBRASKA. LATEST SATELLITE IMAGERY SHOWS A LARGE AREA OF STRATUS CIRCULATING UNDER THE UPPER LEVEL LOW...WITH STRATUS BANDS STRETCHING INTO PORTIONS OF CENTRAL NEBRASKA. UNDER THESE BANDS...METAR SITES HAVE INDICATED CEILING HEIGHTS NEAR 1500 FT AND VISIBILITIES AS LOW AS 1/4 MILE AT VALENTINE. FOR THE VERY NEAR SHORT TERM...THESE STRATUS BANDS WILL BE OF CONCERN. SHORT TERM MODELS SUCH AS THE RAP...SREF...AND HRRR ALL SUGGEST THAT REDUCED VISIBILITIES WILL BE VERY CLOSE TO OUR WESTERN BORDER...WHILE THE GFS REMAINS DRY. AT THIS TIME...CONTINUED WITH AREAS OF FOG IN THE FORECAST...BUT WILL CONTINUE TO MONITOR IN CASE A DENSE FOG ADVISORY IS NEEDED. AS SUCH...AS THE HIGH PRESSURE/RIDGE AXIS SWINGS THROUGH THE PLAINS...EXPECT WINDS TO SWITCH TO SOUTHERLY AND HELP CLEAR OUT ANY FOG THAT DOES DEVELOP BY MID TO LATE MORNING. THE MAIN FOCUS OF THE REST OF THE SHORT TERM PERIOD WILL CENTER ON THE POSSIBILITY FOR FREEZING DRIZZLE AND FOG OVERNIGHT AND INTO WEDNESDAY MORNING. AN UPPER LEVEL SHORT WAVE DISTURBANCE WILL DEVELOP ACROSS THE NORTHERN ROCKIES AND SWING THROUGH THE CENTRAL PLAINS OVERNIGHT. AT THE SURFACE...LIGHT SOUTH WINDS WILL SURGE LOW LEVEL MOISTURE NORTHWARD ACROSS MUCH OF THE AREA. THIS COMBINED WITH LIFT FROM THE UPPER LEVEL DISTURBANCE SHOULD PROMOTE FOG DEVELOPMENT. HOWEVER...SOUNDINGS INDICATE VERY DRY MID LEVELS AND BOTH THE NAM AND GFS SOLUTIONS SUGGESTING HIGHER BULK SHEAR VALUES NEAR 10 KTS...ESPECIALLY ACROSS NORTH CENTRAL KANSAS AND THE STATE LINE. THEREFORE...IT REMAINS A STRONG POSSIBILITY OF FREEZING DRIZZLE ACROSS NORTH CENTRAL KANSAS AND SOUTHERN NEBRASKA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 335 AM CST TUE DEC 9 2014 THE MODELS CONTINUE TO HAVE THE MOISTURE ACROSS THE AREA DURING THE DAY WEDNESDAY AND EVEN INTO WEDNESDAY NIGHT. EXPECT THE FOG AND FREEZING DRIZZLE FROM TUESDAY NIGHT TO CONTINUE INTO WEDNESDAY MORNING. AS TEMPERATURES WARM DURING THE MORNING THE FREEZING DRIZZLE SHOULD BECOME DRIZZLE. THE PRECIPITATION SHOULD REMAIN MAINLY IN THE SOUTHEAST PART OF THE FORECAST AREA. WILL CONTINUE WITH DRIZZLE IN THE SOUTHEAST DURING THE AFTERNOON. THE ONLY MODEL THAT MOVES THE MOISTURE OFF TO THE EAST IS THE GFS...SO WILL KEEP THE DRIZZLE INTO THE NIGHT TIME HOURS. IT SHOULD BE IN THE SOUTHEAST AND SHOULD GRADUALLY END FROM WEST TO EAST DURING THE NIGHT. THURSDAY AND BEYOND THE MODELS HAVE SEVERAL DIFFERENCES IN TIMING AND STRENGTH OF THE SYSTEMS AND EVEN SOME RUN TO RUN INCONSISTENCIES. THERE IS AN UPPER LEVEL RIDGE THAT WILL MOVE THROUGH THE AREA THURSDAY AND FRIDAY. EXPECT THE TEMPERATURES TO WARM UP AS THERE WILL BE PARTLY CLOUDY SKIES AND WARM ADVECTION. AN UPPER LEVEL SYSTEM IN THE ROCKIES WITH A DEVELOPING SURFACE LOW ON THE HIGH PLAINS WILL BRING MOISTURE BACK TO THE AREA ON SATURDAY. THERE WILL BE WARM ADVECTION AND TEMPERATURES WILL BE WARM ON SATURDAY. THE SURFACE LOW AND COLD FRONT WILL MOVE THROUGH THE FORECAST AREA SATURDAY NIGHT. THE COOLER AIR STARTS TO MOVE INTO THE AREA ON SUNDAY AND TEMPERATURES WILL BE A LITTLE COOLER THAN SATURDAY. THE QUESTION BECOMES PRECIPITATION CHANCES. FORECAST SOUNDINGS SHOW THAT THERE WILL BE A DRY LAYER AND HAVE KEPT PRECIPITATION IN THE SOUTHEAST...BUT THAT IS EVEN A LITTLE QUESTIONABLE. BY SATURDAY NIGHT THE MID LEVELS MOISTEN UP SOME AND THERE WILL BE A FEW MORE CLOUDS WITH MAYBE SOME RAIN IN THE EAST. SUNDAY AND SUNDAY NIGHT LOOK LIKE BETTER CHANCES FOR SOME PRECIPITATION. THIS IS THE FIRST RUN WHERE THE GFS AND THE ECMWF ARE A LITTLE MORE CONSISTENT WITH THE UPPER LOW IN THE CENTRAL TO SOUTHERN PLAINS. THE GFS IS FASTER THAN THE ECMWF. WILL KEEP PRECIPITATION CHANCES FOR SUNDAY AND SUNDAY NIGHT...BRINGING UP THE QUESTION OF PRECIPITATION TYPE. SUNDAY THE TEMPERATURES SHOULD BE WARM ENOUGH THAT EXPECT RAIN BUT TEMPERATURES AT 850MB START TO COOL LATE IN THE AFTERNOON. DURING THE NIGHT THE TEMPERATURES CONTINUE TO COOL AND THE RAIN SHOULD MIX WITH AND MAYBE CHANGE TO SNOW DURING THE NIGHT. THE UPPER LOW SHOULD MOVE TO THE EAST AND EXPECT DRY AND COOL CONDITIONS FOR MONDAY. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 457 AM CST TUE DEC 9 2014 AGAIN FOG AND STRATUS DEVELOPMENT REMAIN THE MAIN CONCERNS FOR THE TAF PERIOD. LATEST SATELLITE IMAGERY SHOWS A VERY THIN BAND OF STRATUS SPREADING FROM VALENTINE SOUTHWARD INTO THE LEXINGTON AREA. THE EDGE OF THIS BAND APPEARS TO BE RIGHT OUTSIDE OF THE CITY OF KEARNEY. SHORT TERM MODEL SOLUTIONS SUGGEST THAT IT WILL NOT SPREAD EASTWARD. THUS...DECIDED TO KEEP VFR CONDITIONS AT THE MOMENT FOR KEAR...ALTHOUGH IT BEARS MONITORING. FOR THE REST OF THE DAY HIGH PRESSURE WILL ALLOW WINDS TO SHIFT TO SOUTHERLY BY LATE MORNING. TOWARDS THE END OF THE PERIOD...AN UPPER LEVEL DISTURBANCE WILL SHIFT PASS THE PLAINS...THIS COMBINED WITH LOW LEVEL MOISTURE...LIGHT WINDS AT THE SURFACE...FOG DEVELOPMENT IS POSSIBLE AGAIN TOMORROW MORNING. SOME MODELS ARE ALSO LEANING TOWARDS FREEZING DRIZZLE...ALTHOUGH MORE LIKELY SOUTH OF INTERSTATE 80. WILL NEED TO CONTINUE WATCHING FUTURE MODEL RUNS FOR NORTHWARD EXPANSION OF FREEZING DRIZZLE. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...SALTZMAN LONG TERM...JCB AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1010 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE OFF THE VIRGINIA COAST WILL LIFT NORTH OF THE REGION TODAY. HIGH PRESSURE WILL BUILD OVER THE AREA FROM THE NORTHWEST WEDNESDAY AND THURSDAY AND REMAIN OVER THE REGION INTO THIS WEEKEND. && .NEAR TERM /REST OF TODAY/... AS OF 1010 AM TUESDAY...MORNING UPDATE MAINLY TO CAPTURE PRECIP AND T/TD TRENDS. THE SFC LOW IS LOCATED APPROX 100 MI E OF THE DELMARVA PENINSULAR THIS MORNING AND WILL CONTINUE TO LIFT NORTH TO OFF THE NJ COAST TODAY AS A SHARP UPPER TROUGH DIGS ALONG THE EASTERN SEABOARD. DEEP MOISTURE CONTINUES TO LIFT N ACROSS THE AREA AHEAD OF THE UPPER TROUGH WITH DRIZZLE/SPRINKLES MAINLY OVER THE AREA. WRAP AROUND MOISTURE WILL CONTINUE TO BRING THE THREAT OF LIGHT SHOWERS AS THE SFC LOW LIFTS NORTH OF THE AREA TODAY WITH SOME RAIN NOTED NEAR ROCKY MOUNT AND LOUISBURG CURRENTLY. RAINFALL AMOUNTS WILL BE LIGHT...GENERALLY LESS THAN A TENTH OF AN INCH. MODEL SOUNDINGS INDICATE LOW CLOUDS AND BREEZY TO WINDY NORTHERLY FLOW WILL PERSIST THROUGH THE MUCH DAY PRODUCING RAW CONDITIONS WITH HIGHS IN THE MID TO UPPER 40S INLAND TO LOWER 50S ALONG THE COAST. THE HIGH SURF ADVISORY AND COASTAL FLOOD ADVISORY FOR THE OUTER BANKS NORTH OF CAPE HATTERAS WILL END SHORTLY WITH REPORTS OF OCEAN OVERWASH AGAIN FROM BUXTON NORTH TO PEA ISLAND. && .SHORT TERM /TONIGHT/... AS OF 330 AM TUE...THE UPPER TROUGH DEVELOPS INTO A CUT-OFF LOW ACROSS THE MID ATLANTIC TONIGHT WHILE A ROBUST SHORTWAVE ROTATES THROUGH THE BASE OF THE LOW AND ACROSS THE CAROLINAS. ENOUGH UPPER LEVEL DYNAMICS AND WRAP AROUND MOISTURE TO CONTINUE RAIN CHANCES TONIGHT...MAINLY THROUGH THE EVENING HOURS WITH BETTER CHANCES NORTHERN SECTIONS. AFTER THE EMBEDDED SHORTWAVE MOVES OFFSHORE LATE TONIGHT NWLY FLOW DEVELOPS BRINGING DRYING THROUGH THE COLUMN WITH RAIN CHANCES DIMINISHING. AGAIN...RAINFALL AMOUNTS WILL BE LIGHT WITH ONLY A FEW HUNDREDTHS EXPECTED. LOWS EXPECTED IN THE MID TO UPPER 30S INLAND TO MID 40S COAST. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 245 AM TUESDAY...DEEP MID-LEVEL TROUGH TO LINGER NEAR THE NORTH CAROLINA COAST WEDNESDAY UNTIL LIFTING NORTH THURSDAY AS THE UPPER LEVEL FLOW GRADUALLY BECOMES MORE ZONAL WITH THE TROUGH AXIS GRADUALLY MOVING OFFSHORE BY LATE WEEK. AT THE SURFACE...LOW PRESSURE OVER SOUTHERN NEW ENGLAND WILL SLOWLY MOVE NORTH AND WEAKEN WITH A DOWNSLOPING W/WNW FLOW DEVELOPING ACROSS THE REGION WEDNESDAY AND WEAKENING A BIT ON THURSDAY. SURFACE HIGH PRESSURE THEN BUILDS EAST FOR LATE WEEK WITH AN UPPER RIDGE BUILDING NORTH FROM THE GULF SUNDAY INTO MONDAY. THIS WILL MAKE FOR A DRY FORECAST FOR WEDNESDAY INTO THE WEEKEND. TEMPERATURES...ESPECIALLY MINIMUMS WILL BE BELOW NORMAL THURSDAY INTO SATURDAY WITH MANY AREAS AT OR BELOW FREEZING...ESPECIALLY INLAND. DAYTIME HIGHS WILL BE CHILLY...ESPECIALLY THURSDAY AND FRIDAY WITH HIGHS UPPER 40S TO AROUND 50. AS THE UPPER HIGH BUILDS FROM THE SOUTH...TEMPERATURES WARM TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS WITH LOWER 60S FOR HIGHS BY MONDAY AND TUESDAY. MOISTURE STARTS TO CREEP NORTH FROM THE GULF OF MEXICO WITH A CHANCE OF RAIN RETURNING TO THE REGION BY TUESDAY. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 630 AM TUESDAY...LOW PRES LIFTING NORTH JUST OFF THE VA COAST THIS MORNING. BULK OF THE RAIN ASSOC WITH MID LEVEL ENERGY HAS MOVED EAST OF THE TERMINALS WITH ABUNDANT LOW LEVEL MOISTURE ALLOWING LIFR CONDITIONS TO PREVAIL. NW FLOW AND LOW LEVEL WRAP- AROUND MOISTURE WILL PERSIST TODAY BRINGING A PROLONGED PERIOD OF CIGS AOB IFR...AND POSSIBLY A FEW SHOWERS ACROSS THE AREA. SREF AND NAM STILL APPEAR TO LIFT CIGS TO MVFR TOO QUICKLY THIS MORNING WHILE THE GFS AND HRRR SOLUTIONS KEEP IFR CIGS THROUGH THE AFTERNOON AND EVEN INTO THE EVENING FOR THE COASTAL TAF SITES. MODEL SOUNDING SHOWING COOLING TEMPS ABOVE THE LOW LEVEL INVERSION THROUGH THE AFTERNOON AND THINK THE GFS/HRRR MAY BE HOLDING ON TO IFR CIGS A LITTLE TOO LONG AND HAVE ESSENTIALLY SPLIT THE DIFFERENCE TIMING WISE FOR WHEN CIGS LIFT TO MVFR. MVFR CIGS WILL LIKELY PERSIST THROUGH MUCH OF THE EVENING HOURS BUT MODEL SOUNDINGS INDICATING SUBSTANTIAL DRYING THE COLUMN LATE TONIGHT AS THE UPPER TROUGH LIFTS N AND DEVELOPS INTO A CUT-OFF LOW OVER THE MID-ATLANTIC BRINGING NW FLOW ACROSS THE REGION AND EXPECT VFR CONDITIONS TO RETURN AFTER MIDNIGHT. LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 245 AM TUESDAY...WITH HIGH PRESSURE IN CONTROL AND A DOWNSLOPING W/WNW SURFACE FLOW...EXPECT DRY CONDITIONS AND GENERALLY VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. DEWPOINT DEPRESSIONS AND LOW-LEVEL MIXING APPEARS TO BE SUFFICIENT TO PRECLUDE MUCH IN THE WAY OF VISIBILITY-REDUCING FOG THROUGHOUT THE PERIOD. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 1010 AM TUESDAY...LATEST SURFACE AND BUOY DATA INDICATE NW WINDS 10-20 KT WITH GUSTS TO 25 KT AT DUCK. SEAS REMAIN ELEVATED 9-12 FT NORTH OF OCRACOKE WITH 6-8 FT SOUTH. LOW PRESSURE OFF THE DELMARVA PENINSULA THIS MORNING WILL LIFT NORTH TO OFF THE NJ COAST TODAY. NW WINDS AROUND 15-25 KT THROUGHOUT THE COASTAL WATERS AS THE LOW LIFTS NORTH OF THE AREA...WHICH IS EXPECTED TO CONTINUE IN THIS GENERAL RANGE THROUGH THE SHORT TERM. SEAS WILL VERY SLOWLY SUBSIDE THROUGH THE PERIOD...TO ABOUT 6-10 FT NORTH WHILE CONTINUING AROUND 5-8 FT SOUTHERN WATERS TONIGHT. HAVE EXTENDED THE SCA FOR THE SOUNDS AND ALLIGATOR AS MODELS INDICATING NW WINDS UP TO 25 KT CONTINUING ACROSS THE EASTERN PORTIONS OF THESE ZONES THIS MORNING BUT OTHERWISE HAVE CONTINUED THE SCA AS ADVERTISED. LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 255 AM TUESDAY...WITH CYCLONIC FLOW AROUND LOW PRESSURE MOVING ACROSS SOUTHERN NEW ENGLAND...EXPECT GUSTY WNW/NW WINDS WEDNESDAY AND WEDNESDAY NIGHT BEFORE THE GRADIENT SUBSIDES A BIT ON THURSDAY. SEAS WILL REMAIN ELEVATED...AS HIGH AS 10 FEET WEDNESDAY AND WEDNESDAY NIGHT...BEFORE SUBSIDING BY THURSDAY NIGHT. THE SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 7 PM THURSDAY FOR THE NORTHERN AND SOUTHERN WATERS AND UNTIL 11 PM THURSDAY FOR THE CENTRAL WATERS. LATEST SWAN AND WAVEWATCH INDICATE THAT SEAS FINALLY DROP BELOW 6 FEET THURSDAY EVENING. AFTER A BIT OF A LULL ON FRIDAY...WINDS/SEAS INCREASE AGAIN SATURDAY AS GRADIENT IS PINCHED WITH SURFACE HIGH PRESSURE BUILDING TO THE EAST AND SOME MINIMAL SMALL CRAFT ADVISORY CONDITIONS WILL BE POSSIBLE ONCE AGAIN. && .TIDES/COASTAL FLOODING... AS OF 315 AM TUESDAY...LOW PRES TRACKING NORTH JUST OFF THE COAST THIS MORNING BRINGING STRONG NLY WINDS ACROSS THE OBX WHICH... COMBINED WITH LARGE HIGH ENERGY SEAS ON THE ORDER OF 10-15 FT WITH PERIODS AROUND 12 SECONDS...WILL CONTINUE TO BRING LARGE SURF AND WAVE RUN-UP ALONG THE BEACHES NORTH OF CAPE HATTERAS. OVERWASH IS LIKELY AGAIN WITH THIS MORNINGS HIGH TIDE CYCLE...WHICH PEAKS AROUND 9 AM. MOST VULNERABLE AREAS WILL BE WHERE THE DUNES HAVE BREACHED DURING PREVIOUS HIGH TIDE CYCLES...INCLUDING KITTY HAWK...PORTIONS OF PEA ISLAND INCLUDING THE S-CURVES AT MIRLO BEACH...AND THE HOTELS IN BUXTON. THE WINDS WILL SHIFT TO NW LATER THIS MORNING AS THE LOW BEGINS TO LIFT NORTH OF THE AREA ALLOWING FOR GRADUALLY SUBSIDING SEAS AND IMPROVING CONDITIONS WITH EACH SUBSEQUENT TIDE CYCLE. MINOR EFFECTS MAY LINGER INTO WEDNESDAY MORNING WITH EXTRA-TROPICAL STORM SURGE GUIDANCE INDICATING ABOVE NORMAL TIDES CONTINUING...BUT MUCH IMPROVED CONDITIONS EXPECTED THURSDAY AND FRIDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...HIGH SURF ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR NCZ103. COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NCZ103. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ130- 131-135. SMALL CRAFT ADVISORY UNTIL 11 PM EST THURSDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR AMZ150-156- 158. && $$ SYNOPSIS...SK NEAR TERM...SK/DAG SHORT TERM...SK LONG TERM...CTC AVIATION...CTC/SK MARINE...CTC/SK/DAG TIDES/COASTAL FLOODING...SK
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
640 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE OFF THE VIRGINIA COAST WILL LIFT NORTH OF THE REGION TODAY. HIGH PRESSURE WILL BUILD OVER THE AREA FROM THE NORTHWEST WEDNESDAY AND THURSDAY AND REMAIN OVER THE REGION INTO THIS WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 630 AM TUE...MORNING UPDATE MAINLY TO CAPTURE PRECIP AND T/TD TRENDS. THE SFC LOW IS LOCATED APPROX 100 MI E OF VIRGINIA BEACH EARLY THIS MORNING AND WILL CONTINUE TO LIFT NORTH TO OFF THE NJ COAST TODAY AS A SHARP UPPER TROUGH DIGS ALONG THE EASTERN SEABOARD. DEEP MOISTURE CONTINUES TO LIFT N ACROSS THE AREA AHEAD OF THE UPPER TROUGH WITH LIGHT RAIN NOW MAINLY OVER DARE/HYDE COUNTIES. HRRR LIFTS THE BULK OF THE RAINFALL NORTH OF THE AREA BETWEEN 8-9 AM BUT WRAP AROUND MOISTURE WILL CONTINUE TO BRING THE THREAT OF LIGHT SHOWERS AS THE SFC LOW LIFTS NORTH OF THE AREA WITH BEST CHANCES NORTHERN AREAS. RAINFALL AMOUNTS WILL BE LIGHT...GENERALLY LESS THAN A TENTH OF AN INCH. MODEL SOUNDINGS INDICATE LOW CLOUDS AND BREEZY TO WINDY NORTHERLY FLOW WILL PERSIST THROUGH THE MUCH DAY PRODUCING RAW CONDITIONS WITH HIGHS IN THE MID TO UPPER 40S INLAND TO LOWER 50S ALONG THE COAST. THE HIGH SURF ADVISORY AND COASTAL FLOOD ADVISORY FOR THE OUTER BANKS NORTH OF CAPE HATTERAS CONTINUES THROUGH THE 9 AM HIGH TIDE CYCLE. PLEASE SEE THE TIDES AND COASTAL FLOODING SECTION BELOW FOR DETAILS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... AS OF 330 AM TUE...THE UPPER TROUGH DEVELOPS INTO A CUT-OFF LOW ACROSS THE MID ATLANTIC TONIGHT WHILE A ROBUST SHORTWAVE ROTATES THROUGH THE BASE OF THE LOW AND ACROSS THE CAROLINAS. ENOUGH UPPER LEVEL DYNAMICS AND WRAP AROUND MOISTURE TO CONTINUE RAIN CHANCES TONIGHT...MAINLY THROUGH THE EVENING HOURS WITH BETTER CHANCES NORTHERN SECTIONS. AFTER THE EMBEDDED SHORTWAVE MOVES OFFSHORE LATE TONIGHT NWLY FLOW DEVELOPS BRINGING DRYING THROUGH THE COLUMN WITH RAIN CHANCES DIMINISHING. AGAIN...RAINFALL AMOUNTS WILL BE LIGHT WITH ONLY A FEW HUNDREDTHS EXPECTED. LOWS EXPECTED IN THE MID TO UPPER 30S INLAND TO MID 40S COAST. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 245 AM TUESDAY...DEEP MID-LEVEL TROUGH TO LINGER NEAR THE NORTH CAROLINA COAST WEDNESDAY UNTIL LIFTING NORTH THURSDAY AS THE UPPER LEVEL FLOW GRADUALLY BECOMES MORE ZONAL WITH THE TROUGH AXIS GRADUALLY MOVING OFFSHORE BY LATE WEEK. AT THE SURFACE...LOW PRESSURE OVER SOUTHERN NEW ENGLAND WILL SLOWLY MOVE NORTH AND WEAKEN WITH A DOWNSLOPING W/WNW FLOW DEVELOPING ACROSS THE REGION WEDNESDAY AND WEAKENING A BIT ON THURSDAY. SURFACE HIGH PRESSURE THEN BUILDS EAST FOR LATE WEEK WITH AN UPPER RIDGE BUILDING NORTH FROM THE GULF SUNDAY INTO MONDAY. THIS WILL MAKE FOR A DRY FORECAST FOR WEDNESDAY INTO THE WEEKEND. TEMPERATURES...ESPECIALLY MINIMUMS WILL BE BELOW NORMAL THURSDAY INTO SATURDAY WITH MANY AREAS AT OR BELOW FREEZING...ESPECIALLY INLAND. DAYTIME HIGHS WILL BE CHILLY...ESPECIALLY THURSDAY AND FRIDAY WITH HIGHS UPPER 40S TO AROUND 50. AS THE UPPER HIGH BUILDS FROM THE SOUTH...TEMPERATURES WARM TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS WITH LOWER 60S FOR HIGHS BY MONDAY AND TUESDAY. MOISTURE STARTS TO CREEP NORTH FROM THE GULF OF MEXICO WITH A CHANCE OF RAIN RETURNING TO THE REGION BY TUESDAY. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 630 AM TUESDAY...LOW PRES LIFTING NORTH JUST OFF THE VA COAST THIS MORNING. BULK OF THE RAIN ASSOC WITH MID LEVEL ENERGY HAS MOVED EAST OF THE TERMINALS WITH ABUNDANT LOW LEVEL MOISTURE ALLOWING LIFR CONDITIONS TO PREVAIL. NW FLOW AND LOW LEVEL WRAP- AROUND MOISTURE WILL PERSIST TODAY BRINGING A PROLONGED PERIOD OF CIGS AOB IFR...AND POSSIBLY A FEW SHOWERS ACROSS THE AREA. SREF AND NAM STILL APPEAR TO LIFT CIGS TO MVFR TOO QUICKLY THIS MORNING WHILE THE GFS AND HRRR SOLUTIONS KEEP IFR CIGS THROUGH THE AFTERNOON AND EVEN INTO THE EVENING FOR THE COASTAL TAF SITES. MODEL SOUNDING SHOWING COOLING TEMPS ABOVE THE LOW LEVEL INVERSION THROUGH THE AFTERNOON AND THINK THE GFS/HRRR MAY BE HOLDING ON TO IFR CIGS A LITTLE TOO LONG AND HAVE ESSENTIALLY SPLIT THE DIFFERENCE TIMING WISE FOR WHEN CIGS LIFT TO MVFR. MVFR CIGS WILL LIKELY PERSIST THROUGH MUCH OF THE EVENING HOURS BUT MODEL SOUNDINGS INDICATING SUBSTANTIAL DRYING THE COLUMN LATE TONIGHT AS THE UPPER TROUGH LIFTS N AND DEVELOPS INTO A CUT-OFF LOW OVER THE MID-ATLANTIC BRINGING NW FLOW ACROSS THE REGION AND EXPECT VFR CONDITIONS TO RETURN AFTER MIDNIGHT. LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 245 AM TUESDAY...WITH HIGH PRESSURE IN CONTROL AND A DOWNSLOPING W/WNW SURFACE FLOW...EXPECT DRY CONDITIONS AND GENERALLY VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. DEWPOINT DEPRESSIONS AND LOW-LEVEL MIXING APPEARS TO BE SUFFICIENT TO PRECLUDE MUCH IN THE WAY OF VISIBILITY-REDUCING FOG THROUGHOUT THE PERIOD. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 630 AM TUESDAY...LOW PRES APPROX 100 MI E OF VA BEACH EARLY THIS MORNING WILL LIFT NORTH TO OFF THE NJ COAST TODAY. WINDS BECOMING NW AROUND 15-25 KT THROUGHOUT THE COASTAL WATERS AS THE LOW LIFTS NORTH OF THE AREA...WHICH IS EXPECTED TO CONTINUE IN THIS GENERAL RANGE THROUGH THE SHORT TERM. SEAS AROUND 10-14 FT NORTH OF OREGON INLET AND 5-8 FT SOUTH THIS MORNING WILL VERY SLOWLY SUBSIDE THROUGH THE PERIOD...TO ABOUT 6-10 FT NORTH WHILE CONTINUING AROUND 5-8 FT SOUTHERN WATERS TONIGHT. HAVE EXTENDED THE SCA FOR THE SOUNDS AND ALLIGATOR AS MODELS INDICATING NW WINDS UP TO 25 KT CONTINUING ACROSS THE EASTERN PORTIONS OF THESE ZONES THIS MORNING BUT OTHERWISE HAVE CONTINUED THE SCA AS ADVERTISED. LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 255 AM TUESDAY...WITH CYCLONIC FLOW AROUND LOW PRESSURE MOVING ACROSS SOUTHERN NEW ENGLAND...EXPECT GUSTY WNW/NW WINDS WEDNESDAY AND WEDNESDAY NIGHT BEFORE THE GRADIENT SUBSIDES A BIT ON THURSDAY. SEAS WILL REMAIN ELEVATED...AS HIGH AS 10 FEET WEDNESDAY AND WEDNESDAY NIGHT...BEFORE SUBSIDING BY THURSDAY NIGHT. THE SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 7 PM THURSDAY FOR THE NORTHERN AND SOUTHERN WATERS AND UNTIL 11 PM THURSDAY FOR THE CENTRAL WATERS. LATEST SWAN AND WAVEWATCH INDICATE THAT SEAS FINALLY DROP BELOW 6 FEET THURSDAY EVENING. AFTER A BIT OF A LULL ON FRIDAY...WINDS/SEAS INCREASE AGAIN SATURDAY AS GRADIENT IS PINCHED WITH SURFACE HIGH PRESSURE BUILDING TO THE EAST AND SOME MINIMAL SMALL CRAFT ADVISORY CONDITIONS WILL BE POSSIBLE ONCE AGAIN. && .TIDES/COASTAL FLOODING... AS OF 315 AM TUESDAY...LOW PRES TRACKING NORTH JUST OFF THE COAST THIS MORNING BRINGING STRONG NLY WINDS ACROSS THE OBX WHICH... COMBINED WITH LARGE HIGH ENERGY SEAS ON THE ORDER OF 10-15 FT WITH PERIODS AROUND 12 SECONDS...WILL CONTINUE TO BRING LARGE SURF AND WAVE RUN-UP ALONG THE BEACHES NORTH OF CAPE HATTERAS. OVERWASH IS LIKELY AGAIN WITH THIS MORNINGS HIGH TIDE CYCLE...WHICH PEAKS AROUND 9 AM. MOST VULNERABLE AREAS WILL BE WHERE THE DUNES HAVE BREACHED DURING PREVIOUS HIGH TIDE CYCLES...INCLUDING KITTY HAWK...PORTIONS OF PEA ISLAND INCLUDING THE S-CURVES AT MIRLO BEACH...AND THE HOTELS IN BUXTON. THE WINDS WILL SHIFT TO NW LATER THIS MORNING AS THE LOW BEGINS TO LIFT NORTH OF THE AREA ALLOWING FOR GRADUALLY SUBSIDING SEAS AND IMPROVING CONDITIONS WITH EACH SUBSEQUENT TIDE CYCLE. MINOR EFFECTS MAY LINGER INTO WEDNESDAY MORNING WITH EXTRA-TROPICAL STORM SURGE GUIDANCE INDICATING ABOVE NORMAL TIDES CONTINUING...BUT MUCH IMPROVED CONDITIONS EXPECTED THURSDAY AND FRIDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...HIGH SURF ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR NCZ103. COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NCZ103. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ130- 131-135. SMALL CRAFT ADVISORY UNTIL 11 PM EST THURSDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR AMZ150-156- 158. && $$ SYNOPSIS...SK NEAR TERM...SK SHORT TERM...SK LONG TERM...CTC AVIATION...CTC/SK MARINE...CTC/SK TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
531 AM CST TUE DEC 9 2014 .AVIATION...12Z TAF ISSUANCE... IFR VISIBILITIES WILL PERSIST FOR AIRFIELDS ACROSS PORTIONS OF SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS THROUGH MID TO LATE MORNING AS AREAS OF DENSE FOG REMAIN SPREAD ACROSS THE REGION. VISIBILITIES ARE EXPECTED TO IMPROVE THROUGH NOON... WITH WINDS CONTINUING TO BACK TO THE EAST/SOUTHEAST THROUGH THE AFTN. OVERNIGHT... LIGHT FOG MAY IMPACT VARIOUS SITES ACROSS PORTIONS OF CENTRAL AND SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS ONCE AGAIN. VISIBILITIES WILL LIKELY LINGER BETWEEN MVFR AND VFR... HOWEVER... A POCKETS OF IFR WILL BE POSSIBLE. JTK && .PREV DISCUSSION... /ISSUED 258 AM CST TUE DEC 9 2014/ DISCUSSION... IN RESPONSE TO VERY SHALLOW SFC MOISTURE ACROSS TEXOMA AND THE RED RIVER VALLEY... DENSE FOG WILL REMAIN IN PLACE ACROSS SRN OK AND WRN N TX. RECENT RAP AND HRRR OUTPUT OF VIS AND BOUNDARY LAYER RH VALUES HINT AT FOG EXPANSION NORTHWARD INTO CENTRAL OK FOR AN HOUR OR TWO NEAR SUNRISE BEFORE CONDITIONS IMPROVE THROUGH THE MID TO LATE MORNING HOURS. IN RESPONSE TO THIS... HAVE MADE THE DECISION TO EXTEND THE CURRENT DENSE FOG ADVISORY THROUGH 16Z (10AM CST). AT THE MOMENT... NOT CONVINCED OF WIDESPREAD DENSE FOG REACHING FARTHER NORTH THAN THE CURRENT ADVISORY. HOWEVER... SOME POCKETS OF SHORT DURATION DENSE FOG WILL BE POSSIBLE OUTSIDE THE ADVISORY. WITH THAT IN MIND... AND GIVEN THE CURRENT VIS TRENDS THROUGH 230AM CST... THERE ARE NO PLANS TO EXPAND THE ADVISORY FARTHER NORTH AT THE MOMENT. WE WILL CONTINUE TO WATCH VIS TRENDS CLOSELY THIS MORNING IN THE EVENT AN EXPANSION IS NECESSARY. FOR THE REST OF TODAY... HELPING CLEAR FOG SOUTHWARD THROUGH THE MORNING WILL BE ANOTHER WEAK SFC BOUNDARY... MUCH LIKE THE ONE YESTERDAY. WINDS WILL SLOWLY BACK TO THE EAST ACROSS NRN AND CENTRAL OK THROUGH THE AFTN. TEMPS WILL CLIMB INTO THE 50S FOR HIGHS. OVERNIGHT... AS THE H500 RIDGE BROADENS ACROSS THE WRN U.S... A WEAK H500 SHORT WAVE TROUGH WILL CONTINUE TO APPROACH FROM THE WEST ACROSS ERN NM AND WEST TX. THIS WILL OPEN UP SOME MODEST SFC MOISTURE RETURN FROM THE GULF. PAIRED WITH SOME WEAK LL ISENTROPIC ASCENT AS THE TROUGH SWINGS THROUGH... SOME LIGHT SHOWERS/DRIZZLE MAY DEVELOP ACROSS THE RED RIVER VALLEY LATE WED INTO THU. SLIGHT CHANCES FOR SHOWERS AND DRIZZLE ACROSS PORTIONS OF SOUTHERN AND CENTRAL OK WILL CONTINUE THROUGH FRI AS THE RIDGE OVER THE MIDWEST STRENGTHENS... LEAVING THE SRN PLAINS WITHIN THE WARM SECTOR AND CONTINUAL SFC MOISTURE RETURN. OVERALL... MOST WILL REMAIN DRY... WITH MILD TEMPERATURES CONTINUING. FOR THE WEEKEND... LONG RANGE GUIDANCE... GFS/GFS13KM/ECMWF/CA... HAVE CONTINUED TO SHOW DECENT CONTINUITY OVER THE PAST COUPLE RUNS WITH RESPECT TO THE DEEP H500 TROUGH MOVING INTO THE PLAINS SAT. INCREASED PRECIP CHCS SAT NIGHT INTO SUN. EXPECT SOME RUMBLES OF THUNDER ON SUNDAY. A DECENT LOW... BUFR SOUNDINGS FROM KSPS TO KOUN SHOW COLD TEMPS ALOFT... ENOUGH FOR SOME MINOR ELEVATED INSTABILITY SUPPORTIVE OF SOME ISOLATED THUNDER WITHIN THE RAIN SHOWERS THAT DEVELOP. NOT EXPECTING ANY SIGNIFICANT WEATHER... BUT THE POTENTIAL FOR SOME WELCOME RAINFALL ACROSS THE REGION. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 55 36 55 45 / 0 0 10 10 HOBART OK 57 40 55 46 / 0 0 10 10 WICHITA FALLS TX 58 42 58 48 / 0 0 10 20 GAGE OK 54 37 54 42 / 0 0 10 10 PONCA CITY OK 48 32 50 42 / 0 0 10 20 DURANT OK 60 40 55 45 / 0 0 0 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR OKZ033>048- 050>052. TX...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR TXZ083>090. && $$ 30/04/04
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
926 AM CST TUE DEC 9 2014 .UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS PER CURRENT HRLY TEMP... DEWPOINT...WINDS...ALONG WITH HAVING TEMPS FALLING DURING THE AFTERNOON HRS ACROSS PLATEAU REGION. OTHERWISE...CURRENT FORECAST AND BELOW FORECAST REASONING REMAIN ON TRACK. WE ARE STILL EXPERIENCING COMMS PROBLEMS HERE AT THE NWS NASHVILLE OFFICE WHICH INCLUDES PHONE LINES WORKING OFF AN ON...INTERNET DOWN... ALONG WITH NWR OUTAGES. TECHNICIANS ARE CONTINUE TO LOOK INTO THIS PROBLEM AND APPOLOGIZE FOR ANY INCONVIENCES THAT IT HAS OR MIGHT CAUSE THIS MORNING AND HOPE TO HAVE THIS FIXED AS SOON AS POSSIBLE. && .PREV DISCUSSION.../ISSUED 649 AM CST TUE DEC 9 2014/ UPDATE...FOR 12Z TAFS. AVIATION... PLENTY OF LOW-LEVEL MOISTURE REMAINING ACROSS THE MID-STATE BEHIND PASSING UPPER TROUGH. THIS WILL LEAVE PLENTY OF CLOUDS ACROSS THE REGION...LARGELY AT VFR HEIGHTS BUT CLOUDS ARE EXPECTED TO LOWER/REFORM OVERNIGHT AND THOSE MAY BE AOB 3KFT. SOME LIGHT MIXED PCPN ALSO POSSIBLE CSV TODAY. WINDS ARE EXPECTED TO BECOME QUITE GUSTY FOR THE NORTHWEST BY MIDDAY. PREV DISCUSSION.../ISSUED 330 AM CST TUE DEC 9 2014/ DISCUSSION... UPPER LEVEL SYSTEM OVER INDIANA WILL DROP SOUTHEASTWARD THIS MORNING AND WILL MOVE ACROSS EASTERN TN THIS AFTERNOON. THOUGH THE BETTER DEFORMATIONAL INFLUENCES WILL BE TO THE LEFT OF THE TRACK...WE DO PICK UP SOME DESCENT CURVATURE AND SHEAR ON THE RIGHT SIDE OF THE TRACK. LATEST SATELLITE IMAGERY SHOWS THE LOWER TO MID LEVEL CLOUDINESS TO OUR NORTH ACROSS IL...IN AND NRN MO. LATEST HRRR AND MODEL DATA BOTH CONCUR WITH SCATTERED LIGHT SHOWER ACTIVITY ACROSS THE EASTERN PORTIONS OF THE MID STATE THROUGH TODAY AND INTO TONIGHT. AN EXAMINATION OF FREEZING LEVELS DOES SUPPORT SNOW FOR AREAS GENERALLY ABOVE 1500 FT MSL AFT 18Z TODAY. BY 00Z THE ENTIRE EASTERN THIRD OF THE MID STATE...WHERE THE CHANCES OF PRECIP EXISTS...WILL BE SNOW. AMOUNTS LOOK VERY LIGHT AND NO ADVISORIES OR SPS PRODUCTS ARE NEEDED. FURTHERMORE...SFC TEMPS SHOULD GENERALLY REMAIN ABOVE FREEZING UNTIL LATE TONIGHT. A LOW CHANCE OF SNOWFALL WILL CONTINUE ACROSS THE EAST FOR TONIGHT BUT AMOUNTS AGAIN WILL BE LIGHT. FOR THE FCST...WILL INCLUDE A CHANCE OF RAIN AND SNOW EASTERN THIRD FOR THIS MORNING...JUST RAIN SOUTHEAST. THIS AFTERNOON...WILL TREND THE GRIDS TOWARD A CHANCE OF ALL SNOW FOR THE EASTERN AREA BY EVENING. 850 MB TEMPS WILL BE WELL BELOW 0C AND FREEZING LEVELS WILL BE DROPPING AS WELL AS SFC TEMPS WHICH WILL BE FALLING THROUGH THE 30S. IMPROVING CONDITIONS WILL OCCUR ON WEDNESDAY WITH PARTLY CLOUDY SKIES EXPECTED. IN FACT...MOSTLY CLEAR AND MOSTLY SUNNY SKIES ARE ON TAP FOR WED NT AND THU. TEMPS THROUGH THE EXTENDED WILL REMAIN BELOW NORMAL AS A UNIFORM NORTHERLY FLOW CONTINUES WITH ONLY A VERY SLOW INCREASE IN HEIGHT VALUES. IN THE EXTENDED FCST...HEIGHT VALUES WILL CONTINUE TO INCREASE WITH A RIDGE AXIS REACHING THE AREA ON SATURDAY. THIS WILL EQUATE TO DRY CONDITIONS AND A WARMING TREND. LATE IN THE EXTENDED HOWEVER...A COLD FRONT WILL BRING AN INCREASE IN CLOUDINESS AND A LOW CHANCE OF SHOWER ACTIVITY ON MONDAY. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
649 AM CST TUE DEC 9 2014 .UPDATE...FOR 12Z TAFS. && .AVIATION... PLENTY OF LOW-LEVEL MOISTURE REMAINING ACROSS THE MID-STATE BEHIND PASSING UPPER TROUGH. THIS WILL LEAVE PLENTY OF CLOUDS ACROSS THE REGION...LARGELY AT VFR HEIGHTS BUT CLOUDS ARE EXPECTED TO LOWER/REFORM OVERNIGHT AND THOSE MAY BE AOB 3KFT. SOME LIGHT MIXED PCPN ALSO POSSIBLE CSV TODAY. WINDS ARE EXPECTED TO BECOME QUITE GUSTY FOR THE NORTHWEST BY MIDDAY. && .PREV DISCUSSION... /ISSUED 330 AM CST TUE DEC 9 2014/ DISCUSSION... UPPER LEVEL SYSTEM OVER INDIANA WILL DROP SOUTHEASTWARD THIS MORNING AND WILL MOVE ACROSS EASTERN TN THIS AFTERNOON. THOUGH THE BETTER DEFORMATIONAL INFLUENCES WILL BE TO THE LEFT OF THE TRACK...WE DO PICK UP SOME DESCENT CURVATURE AND SHEAR ON THE RIGHT SIDE OF THE TRACK. LATEST SATELLITE IMAGERY SHOWS THE LOWER TO MID LEVEL CLOUDINESS TO OUR NORTH ACROSS IL...IN AND NRN MO. LATEST HRRR AND MODEL DATA BOTH CONCUR WITH SCATTERED LIGHT SHOWER ACTIVITY ACROSS THE EASTERN PORTIONS OF THE MID STATE THROUGH TODAY AND INTO TONIGHT. AN EXAMINATION OF FREEZING LEVELS DOES SUPPORT SNOW FOR AREAS GENERALLY ABOVE 1500 FT MSL AFT 18Z TODAY. BY 00Z THE ENTIRE EASTERN THIRD OF THE MID STATE...WHERE THE CHANCES OF PRECIP EXISTS...WILL BE SNOW. AMOUNTS LOOK VERY LIGHT AND NO ADVISORIES OR SPS PRODUCTS ARE NEEDED. FURTHERMORE...SFC TEMPS SHOULD GENERALLY REMAIN ABOVE FREEZING UNTIL LATE TONIGHT. A LOW CHANCE OF SNOWFALL WILL CONTINUE ACROSS THE EAST FOR TONIGHT BUT AMOUNTS AGAIN WILL BE LIGHT. FOR THE FCST...WILL INCLUDE A CHANCE OF RAIN AND SNOW EASTERN THIRD FOR THIS MORNING...JUST RAIN SOUTHEAST. THIS AFTERNOON...WILL TREND THE GRIDS TOWARD A CHANCE OF ALL SNOW FOR THE EASTERN AREA BY EVENING. 850 MB TEMPS WILL BE WELL BELOW 0C AND FREEZING LEVELS WILL BE DROPPING AS WELL AS SFC TEMPS WHICH WILL BE FALLING THROUGH THE 30S. IMPROVING CONDITIONS WILL OCCUR ON WEDNESDAY WITH PARTLY CLOUDY SKIES EXPECTED. IN FACT...MOSTLY CLEAR AND MOSTLY SUNNY SKIES ARE ON TAP FOR WED NT AND THU. TEMPS THROUGH THE EXTENDED WILL REMAIN BELOW NORMAL AS A UNIFORM NORTHERLY FLOW CONTINUES WITH ONLY A VERY SLOW INCREASE IN HEIGHT VALUES. IN THE EXTENDED FCST...HEIGHT VALUES WILL CONTINUE TO INCREASE WITH A RIDGE AXIS REACHING THE AREA ON SATURDAY. THIS WILL EQUATE TO DRY CONDITIONS AND A WARMING TREND. LATE IN THE EXTENDED HOWEVER...A COLD FRONT WILL BRING AN INCREASE IN CLOUDINESS AND A LOW CHANCE OF SHOWER ACTIVITY ON MONDAY. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
624 AM CST TUE DEC 9 2014 .AVIATION... ...WIDESPREAD DENSE FOG EVENT UNDERWAY ACROSS MANY NORTH TEXAS AIRPORTS... PRIMARY CHALLENGE THIS MORNING WILL BE TIMING THE DISSIPATION OF LIFR AND IFR CEILINGS AND VISIBILITIES. OBSERVATIONS AT ALL 6 TAF SITES INDICATED DENSE FOG WITH VISIBILITY VALUES AT OR BELOW ONE QUARTER MILE. EVEN THOUGH THE FOG IS RELATIVELY SHALLOW...THE DISSIPATION PROCESS IS LIKELY TO BE SLOW GIVEN THE VERY LIGHT LOW LEVEL WINDS...TIME OF YEAR...AND THE WIDESPREAD NATURE OF THE SURFACE-BASED CLOUD DECK. EXPECT A RAPID IMPROVEMENT IN VISIBILITY AFTER 15Z /9 AM CST/...BUT THE SUBSEQUENT IFR CEILINGS ARE LIKELY TO PERSIST UNTIL 18Z OR 19Z. SURFACE WINDS WILL BE LIGHT AND VARIABLE THROUGH THE PERIOD AS SURFACE RIDGE MOVES ACROSS THE REGION TODAY. A REPEAT OF THE WIDESPREAD DENSE FOG IS NOT EXPECTED TONIGHT / WEDNESDAY MORNING SINCE MID AND HIGH LEVEL CLOUD COVER WILL INHIBIT RADIATIONAL COOLING. 09/GP && .PREV DISCUSSION... /ISSUED 356 AM CST TUE DEC 9 2014/ AS OF 3 AM...WIDESPREAD DENSE FOG HAS SETTLED IN OVER ALL BUT THE SOUTHERN ZONES WHERE HIGH CLOUDS WERE IMPEDING RADIATIVE HEAT LOSS A BIT. STILL WE EXPECT FOG TO CONTINUE TO EXPAND SOUTHWARD BEFORE SUNRISE. ACROSS THE NORTHERN 2/3RDS OF THE CWA...CONDITIONS ARE EXTREMELY FAVORABLE FOR DENSE FOG AND IT IS LIKELY THAT IT WILL BE SLOWER THAN USUAL TO LIFT AND BURN OFF. THE DENSE FOG ADVISORY EXPIRES AT 10AM...BUT IT MAY NEED TO BE EXTENDED AN HOUR OR TWO FROM I-20 NORTH. WINDS BELOW 850MB THIS MORNING ARE EXPECTED TO BE VERY LIGHT...IF NOT NEARLY CALM...WHICH MEANS THE LOW ANGLE DECEMBER SUN WILL BE THE ONLY THING WORKING TO LIFT THE FOG AND LOW CLOUDS TODAY. CLOUDS WILL BE SLOWEST TO ERODE TODAY FROM ROUGHLY I-20 TO THE RED RIVER...BUT OUT OF ALL OF THE MODEL GUIDANCE...ONLY THE RUC HAS THESE CLOUDS HANGING IN THROUGH EARLY AFTERNOON. OBVIOUSLY THE EXACT EROSION OF THE LOW CLOUDS WILL HAVE HUGE IMPLICATIONS ON HIGH TEMPS TODAY...BUT AM LEANING TOWARD THE RUC SOLUTION AND WILL KEEP TEMPS SEVERAL DEGREES BELOW TRADITIONAL GUIDANCE FROM I-20 NORTHWARD. IF AND WHERE CLOUDS HOLD IN ALL AFTERNOON...HIGHS WILL LIKELY ONLY BE IN THE LOWER 50S. INCREASING MID-HIGH LEVEL MOISTURE/CLOUDS TONIGHT WILL LIMIT RADIATIONAL COOLING AT THE SURFACE WHICH SHOULD NIX THE DENSE FOG POTENTIAL. THIS MOISTURE WILL BE ARRIVING IN ADVANCE OF A WELL DEFINED SHORTWAVE TROUGH THAT IS CURRENTLY NEAR BAJA. WHILE THIS SYSTEM IS FORECAST TO WEAKEN AS IT ENTERS MORE CONFLUENT FLOW ACROSS OUR REGION...WATER VAPOR LOOP SHOWS IT HAS TAPPED INTO A HEALTHY AMOUNT OF MID-UPPER LEVEL PACIFIC MOISTURE AND IS SLINGING IT INTO TEXAS. THE ECMWF/NAM ARE THE MOST AGGRESSIVE WITH INCREASING MOISTURE PROFILES OVER OUR REGION WEDNESDAY AND WEDNESDAY NIGHT...AND GIVEN THE LATEST SATELLITE TRENDS AM INCLINED TO BELIEVE THEM. THEREFORE HAVE INCREASED THE CHANCES FOR LIGHT RAIN SHOWERS WEDNESDAY AND INTO THURSDAY. THERE WILL BE A LAYER OF DRIER AIR BELOW THIS MOISTURE THAT WILL KEEP PRECIP FROM REACHING THE GROUND WEDNESDAY...BUT THIS LAYER SHOULD SATURATE FROM TOP DOWN BY WEDNESDAY NIGHT. WE HAVE INTRODUCED SPRINKLES INTO THE FORECAST WEDNESDAY AFTERNOON...AS MEASURABLE PRECIP WILL BE UNLIKELY INITIALLY. THE BEST CHANCES OF MEASURABLE RAIN WILL OCCUR WEDNESDAY NIGHT AND THURSDAY AND PRIMARILY OVER THE SOUTHERN HALF OF THE CWA WHERE A TINY AMOUNT OF MID LEVEL INSTABILITY WILL BE AVAILABLE. QPF WILL BE LOW WITH THIS SYSTEM AND WE EXPECT LESS THAN 1/10 OF AN INCH. HIGHS WEDNESDAY AND THURSDAY LOOK TO REMAIN SEASONABLY COOL AS THICK CLOUD COVER WILL INHIBIT DAYTIME WARMING. AS THE SYSTEM EXITS THURSDAY EVENING...THE MID TO UPPER LEVELS WILL DRY OUT SUBSTANTIALLY. HOWEVER THE LOW LEVELS WILL REMAIN MOIST AND NEARLY SATURATED...WHICH WILL PROMOTE CONTINUED MOSTLY CLOUDY SKIES WITH JUST A SLOW WARMING TREND INTO THE WEEKEND. SOUTHERLY WINDS INCREASE SATURDAY AHEAD OF A STRONG UPPER LEVEL TROUGH THAT WILL MOVE INTO THE FOUR CORNERS REGION. WHILE MODEL GUIDANCE CONTINUES TO SHOW AN UPPER LEVEL LOW CLOSING OFF AT THE BASE OF THE TROUGH...THEY HAVE SHIFTED THE TRACK FARTHER TO THE NORTH THAN YESTERDAY/S MODEL RUNS. STILL...THE TRACK OF THIS SYSTEM WOULD PLACE NORTH TEXAS IN A REGION OF STRONG DYNAMIC LIFT AND GIVEN THE AMPLE LOW LEVEL MOISTURE ALREADY IN PLACE THIS SHOULD RESULT IN A GOOD CHANCE OF WIDESPREAD RAIN SUNDAY AND/OR SUNDAY NIGHT. WHILE SHEAR PROFILES ARE STRONG...SURFACE INSTABILITY LOOKS TO BE VERY LIMITED AND SHOULD LIMIT THE SEVERE WEATHER THREAT. 925MB THETA-E VALUES DO SUPPORT ENOUGH INSTABILITY FOR THE INCLUSION OF THUNDERSTORMS IN THE FORECAST BUT MUCAPE LOOKS TO BE LESS THAN 500 J/KG. RAIN CHANCES SHOULD END FROM WEST TO EAST SUNDAY NIGHT WITH THE PASSAGE OF A COLD FRONT. TEMPS WILL COOL BACK TO NEAR NORMAL FOR MONDAY...BUT WRAP-AROUND LOW CLOUDS MAY KEEP MONDAY/S HIGHS COOLER THAN CURRENTLY ADVERTISED. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 58 44 61 51 59 / 0 5 10 20 20 WACO, TX 62 42 60 51 63 / 0 5 20 30 30 PARIS, TX 60 39 55 43 55 / 0 5 5 20 20 DENTON, TX 57 40 60 49 58 / 0 5 10 20 20 MCKINNEY, TX 58 39 59 48 58 / 0 5 10 20 20 DALLAS, TX 59 45 60 50 60 / 0 5 10 20 20 TERRELL, TX 60 42 60 48 59 / 0 5 10 20 20 CORSICANA, TX 61 44 62 50 59 / 0 5 10 30 30 TEMPLE, TX 64 45 62 52 64 / 0 5 20 30 30 MINERAL WELLS, TX 61 42 59 51 62 / 0 5 10 20 20 && .FWD WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR TXZ091>095- 100>107-115>123-129>135-141>148-156>162-174-175. && $$ 09/
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
530 AM CST TUE DEC 9 2014 .AVIATION... THICK FOG CONTINUES IN AND OUT AT KCDS MAKING TAF FORECASTING A BIT TEDIOUS. AT KLBB AND KPVW...WE EXPECT A LIGHT FOG TO ENVELOPE THE AREA THROUGH MID MORNING THOUGH ALSO CANNOT COMPLETELY RULE OUT DENSE FOG AS WELL. LATEST HRRR SOLUTIONS CONTINUE TO INSIST ON A RISK OF VERY LOW VISIBILITY AT KLBB AND KPVW WHILE THE MUCH LARGER DENSE FOG AREA CONTINUES ON THE HRRR RUNS FROM NEAR CHILDRESS TO THE EAST AND SOUTH. SHOULD IMPROVE BOTH SITES TO IFR BY MID TO LATE MORNING WITH ONLY HIGH CLOUDS MUCH OF THE DAY. TONIGHT WE EXPECT A THICK BATCH OF LOW LEVEL MOISTURE TO SPREAD NORTHWARD THROUGH KLBB AND POSSIBLY KCDS. TENTATIVE FORECAST FOR 18 HOURS AND BEYOND WILL INDICATE PREVAILING MVFR CONDITIONS AT KPVW AND KLBB. A RISK FOR MUCH WORSE CONDITIONS EXISTS BY 12Z WEDNESDAY BUT WILL LEAVE DETAILS TO LATER FORECASTS. RMCQUEEN && .PREV DISCUSSION... /ISSUED 331 AM CST TUE DEC 9 2014/ SHORT TERM... A WEAK UPPER TROUGH CROSSING ARIZONA TODAY WILL EDGE INTO THE SOUTHERN ROCKIES TONIGHT. MEAGER UPPER LEVEL LIFT WILL EDGE TOWARDS THE WESTERN SOUTH PLAINS LATER TONIGHT WHILE A MASS OF 800MB TO 900MB MOISTURE WILL EXPAND ACROSS AREAS ON THE CAPROCK ESPECIALLY. ALTHOUGH COUPLING WITH THE UPPER TROUGH IS NOT APPARENT...WE THINK THERE COULD BE ADEQUATE LOW LEVEL LIFT TO SUPPORT A SLIGHT CHANCE OF SHOWERS MAINLY IN THE WEST OR SOUTHWESTERN PART OF THE SOUTH PLAINS. AND THIS LOW LEVEL MOISTURE INCREASE SHOULD FUEL ANOTHER BOUT OF FOG FROM THE CAPROCK ACROSS THE SOUTHEAST PANHANDLE. INCREASE IN HIGH CLOUDS TODAY SHOULD KNOCK A CATEGORY OFF HIGHS TODAY FROM YESTERDAY. THE MOISTURE INCREASE TONIGHT SHOULD HOLD MINIMUMS QUITE A BIT ABOVE NORMAL. PLAN TO MAINTAIN THIS MORNINGS DENSE FOG ADVISORY FOR SOME PORTION OF THE ROLLING PLAINS...WILL ADD OR RETRACT AREAS AS NEEDED. RMCQUEEN LONG TERM... THE WEAK UPPER LEVEL TROUGH MOVING TOWARDS THE AREA WILL PASS OVER WEST TEXAS ON WEDNESDAY BUT WILL CONTINUE TO BRING MEAGER CHANCES OF PRECIPITATION. A GOOD FETCH OF MID AND HIGH LEVEL MOISTURE IS OBSERVED WITH THIS SHORT WAVE ON WATER VAPOR IMAGERY. GOOD LOW LEVEL MOISTURE WILL REMAIN IN PLACE BUT WE WILL STILL HAVE TO CONTEND WITH A NOTICEABLE DRY LAYER AROUND 700MB SIMILAR TO THE SHORT WAVE TROUGH FROM A FEW DAYS AGO. WITH SUCH WEAK LIFT ASSOCIATED WITH THIS SHORT WAVE NOT MUCH MORE THAN SPRINKLES OR VERY LIGHT RAIN SHOWERS WILL BE LIKELY. WITHOUT ANY SIGNIFICANT TROUGHS OR COLD FRONTS...LOW LEVEL MOISTURE WILL REMAIN ABUNDANT THROUGH AT LEAST FRIDAY. DEW POINTS WILL BE INCREDIBLY HIGH FOR DECEMBER AND MAY LEAD TO FOG EVERY MORNING THROUGH FRIDAY. THE WEATHER CONDITIONS WILL CHANGE OVER THE WEEKEND WITH THE APPROACH OF A MORE SIGNIFICANT TROUGH. MODELS ARE IN GOOD AGREEMENT BUT CONTINUE TO BOUNCE AROUND WITH EACH MODEL ITERATION. ENSEMBLES CONFIRM THE UNCERTAINTY WITH HIGH SPREAD IN THE THEIR SOLUTIONS. UNFORTUNATELY...THIS SYSTEM IS TRENDING PROGRESSIVE WITH ONLY A QUICK SHOT OF PRECIPITATION FROM SATURDAY NIGHT INTO SUNDAY. LEE TROUGHING AHEAD OF THIS SYSTEM ON FRIDAY AND SATURDAY WILL LEAD TO MORE FAMILIAR WARM...DRY...AND BREEZY CONDITIONS. ALTHOUGH THE LARGE CAVEAT IN ALL OF THIS IS THAT THIS SYSTEM IS STILL AROUND 3500 MILES AWAY OVER THE NORTH-CENTRAL PACIFIC. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 62 42 58 37 65 / 0 10 10 10 0 TULIA 63 43 59 41 64 / 0 10 10 10 10 PLAINVIEW 64 43 59 40 64 / 0 10 10 10 10 LEVELLAND 63 47 60 42 64 / 0 10 10 10 10 LUBBOCK 63 46 60 42 65 / 0 10 10 10 10 DENVER CITY 63 47 59 42 63 / 0 10 10 10 10 BROWNFIELD 63 47 59 44 63 / 0 10 10 10 10 CHILDRESS 63 42 61 46 65 / 0 10 10 10 10 SPUR 64 46 62 47 64 / 0 10 10 10 10 ASPERMONT 64 45 63 49 65 / 0 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE FOLLOWING ZONES: TXZ026-032-038-044. && $$ 99/99/05
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
731 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE OFF THE COAST OF VIRGINIA WILL DEEPEN AS IT SHIFTS UP TOWARD THE JERSEY COAST BY TUESDAY AFTERNOON. A TROUGH OF LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES REGION AND MERGE WITH THE COASTAL LOW BY TUESDAY NIGHT OVER NEW ENGLAND. ONCE THIS HAPPENS OUR AREA WILL STAY IN A NORTHWEST FLOW THROUGH THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 720 AM EST TUESDAY... WILL BE LETTING THE REST OF THE WINTER WX ADVISORY EXPIRE AT 8 AM. NO PRECIP TO SPEAK OF IN THE COLDER AREAS THIS MORNING...BUT THERE REMAINS PATCHY DZ/FZDZ OR FOG. THINK AS THE NW/N FLOW INCREASES WILL SEE THE SRN SHENANDOAH VALLEY/HIGHLANDS SCOUR OUT...BUT MODELS DO CONTINUE TO HINT AT A NARROW BAND OF PRECIP ROTATING BACK ACROSS THE FOOTHILLS AND PIEDMONT OF VA...ALONG AND NORTH OF AN AMHERST TO HALIFAX LINE BY LATE MORNING...BUT APPEARS TEMPS WILL BE ABOVE FREEZING THEN...SO NO WINTER PTYPE CONCERNS. FURTHER WEST...SLOWER TIMING OVERALL WITH UPPER LOW MOVING ACROSS KY...AND PRECIP ARRIVING IN THE MTNS. LOOKS LIKE THE LATEST RAP IS NOT THAT FAR OFF AND WILL START TO SEE PRECIP MAINLY RAIN...SOME SNOW SHOWERS MOVING INTO THE MTNS OF NC/FAR SW VA AND SE WV BEFORE NOON. NOT TOO MUCH ELSE CHANGED IN THE FORECAST THRU THE DAY. PREVIOUS DISCUSSION AT 330 AM TODAY... UPPER LOW CLOSING OFF ACROSS THE OHIO VALLEY THIS MORNING WILL TRACK INTO THE SOUTHEAST MOUNTAINS OF KY BY MIDDAY TURNING THE UPPER FLOW MORE SOUTHERLY...AND ENHANCING THE SFC LOW MOVING NWD TOWARD THE DELMARVA. FOR US...THIS UPPER LOW WILL BRING SOME DRYING BEFORE WE GET THE SFC WINDS TURNED AROUND MORE TOWARD THE NW WITH LOW LVL MOISTURE BANKED UP ACROSS THE WRN CWA. AT THE SAME TIME...THE MODELS ARE ENHANCING A BACK EDGE BAND OF PRECIP TOWARD OUR NERN CWA THIS AFTERNOON ROUGHLY FROM AMHERST COUNTY SOUTHEAST TO CHARLOTTE COUNTY. MADE ADJUSTMENTS TO THE FORECAST TO HANG ONTO CHANCE POPS THROUGH THE DAY. THIS MORNING THE WINTRY PRECIP HAS ALL BUT ENDED AS TEMPS REMAIN STUCK IN THE LOWER TO MID 30S. COLDEST TEMPS LIE WEST OF THE BLUE RIDGE...AND MORE AWAY FROM WHERE ANY SUBSTANTIAL PRECIP IS FALLING. THERE WILL BE SOME PATCHY SLEET/SNOW OVER THE SRN SHENANDOAH VLY THIS MORNING INTO THE ALLEGHANYS AND BLUE RIDGE NORTH OF ROANOKE...SO WILL MAINTAIN THE ADVISORY HERE...WHILE VIRGINIA DOT CONTINUES TO SHOW MINOR ACCUMULATION ON ROADS GENERALLY FROM COVINGTON TO LEXINGTON AND NORTH. WILL CANCEL THE ADVISORY FROM NEW CASTLE TO ROANOKE TO ROCKY MOUNT SOUTH. POTENTIAL FOR CANCELLING FURTHER NORTH EARLY IF ALL PRECIP EXITS SOONER. PERUSING THE ROAD TEMPS VIA DOT...MOST IN OUR CWA ARE JUST ABOVE FREEZING...OF COURSE THIS DOES NOT COVER THE SECONDARY HIGHWAYS...SO SOME BRIDGES AND OVERPASSES COULD HAVE A FEW SLICK SPOTS. IN ADDITION...THERE IS SOME THICK FOG ALONG THE MOUNTAINS...AND SOME RIME ICING COULD OCCUR AND ALSO LEAD TO PATCHY SLICK SPOTS AT ELEVATIONS ABOVE 2500 FT WEST ALONG AND WEST OF THE BLUE RIDGE. 8H TEMPS WILL START TO DROP FROM WEST TO EAST BY THIS AFTERNOON. THIS MORNING THE 0C ISOTHERM LIES OVER SE WV SOUTH INTO FAR SW VA. BY MIDDAY IT SHOULD BE TO THE BLUE RIDGE...THEN EAST OF THE CWA EARLY THIS EVENING AS THE UPPER LOW SLIDES ACROSS THE CAROLINAS. THIS PATH DRIVES THE COLDER AIR FIRST INTO THE NC MTNS THEN NORTH...AND SEEMS TO FAVOR HIGHER POPS FOR THE NC MTNS FIRST AS WELL...THEN AS THE LOW MOVES NE OVER THE MID ATLANTIC TONIGHT THE NEXT VORT SHIFTS ACROSS THE WV MTNS...AND CONTINUES THE SNOW SHOWERS HERE. MODELS INDICATE LIGHT AMOUNTS AS THE TRAJECTORIES DO NOT FAVOR MAXIMUM UPSLOPE ENHANCEMENT...BUT STILL A 1 TO 3 INCH RANGE IS EXPECTED...WITH THE HIGHER END...3 INCHES OVER THE NW SECTIONS OF GREENBRIER COUNTY. AT THIS TIME...THERE WILL BE NO HEADLINES ADDED...FOR THE UPSLOPE THOUGH COULD SEE WRN GREENBRIER GET ADDED LATER TODAY IF MODEL SOLUTIONS FAVOR MORE QPF. FOR HIGHS TODAY WENT CLOSE TO WHAT WE HAD PREVIOUSLY. TEMPS WILL BE STEADY OR COULD SLOWLY RISE IN THE WEST BEFORE THE STRONG CAA ARRIVES WITH THE UPPER LOW...BUT STILL KEEPING THE MOUNTAINS IN THE 30S...WITH AROUND 40 ACROSS THE NRV...AND MID TO UPPER 40S EAST...ESPECIALLY IF CLEARING TAKES SHAPE. THINK THE SRN CWA EAST OF THE BLUE RIDGE IN NC THRU SOUTHSIDE VA COULD SEE SOME SUN AT TIME THIS AFTERNOON. TONIGHT...WINDS PICK UP LATE AND WITH CLOUDS IN THE WEST AND 8H TEMPS AROUND -6C...SHOULD SEE LOWS IN THE MID TO UPPER 20S...WHILE WINDS ALSO KEEP THE EASTERN CWA MIXED ENOUGH TO BRING THEM DOWN INTO THE LOWER TO MID 30S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 AM EST TUESDAY... SURFACE LOW PRESSURE NEAR LONG ISLAND WEDNESDAY MORNING WILL MOVE SLOWLY NORTH INTO THE INTERIOR OF NEW ENGLAND BY THURSDAY NIGHT. NORTHWEST FLOW WILL CONTINUE FOR OUR AREA WITH A PROLONGED PERIOD OF UPSLOPE RAIN/SNOW SHOWERS FOR THE PREFERRED AREAS OF SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. THERE WILL BE SOME DOWNWIND ISOLATED TO SCATTERED SHOWERS EAST TO NEAR THE CREST OF THE BLUE RIDGE. AS TIME PROGRESSES THROUGH THURSDAY...COVERAGE OF THE RAIN/SNOW SHOWERS WILL DECREASE AS PROGRESSIVELY DRIER AIR WORKS ITS WAY INTO THE REGION. GUSTY NORTHWEST WINDS MAY BE POSSIBLE ACROSS THE HIGHER TERRAIN ESPECIALLY ABOVE 3K FEET WITH GUSTS BELOW WIND ADVISORY LEVELS. SOME LIGHT ACCUMULATING SNOW IS POSSIBLE IN THE FAVORED UPSLOPE LOCATIONS. SNOWFALL TOTALS DURING THIS PORTION OF THE FORECAST WILL BE GREATEST ACROSS WESTERN GREENBRIER COUNTY WEST VIRGINIA WITH A 1 TO 3 INCH RANGE. THE REMAINDER OF THE PREFERRED UPSLOPE REGION OF SOUTHEAST WEST VIRGINIA WILL MAINLY BE UNDER AN INCH. CAN NOT RULE OUT AROUND ONE INCH FOR THE HIGHER TERRAIN OF WESTERN ASHE AND WATAUGA COUNTIES IN NORTHWEST NORTH CAROLINA. LIGHTER TOTALS EXPECTED ACROSS THE REST OF THE MOUNTAINS. HIGH PRESSURE WILL BUILD EAST INTO OUR AREA BY THURSDAY NIGHT INTO FRIDAY MORNING. TEMPERATURES DURING THE PERIOD WILL AVERAGE A FEW DEGREES BELOW NORMAL. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 PM EST MONDAY... MODELS ARE NOW IN THE SAME BALLPARK FOR THE EXTENDED...JUST NOT SURE IF THE GAME IS FOOTBALL OR SOCCER. EVOLUTION TO A HIGHLY AMPLIFIED UPPER PATTERN WITH DEVELOPMENT OF A CLOSED LOW DOING A SIT AND SPIN OVER THE NORTHEAST US IS A FAVORED SOLUTION THROUGH THE END OF THE WEEK. BEGIN TO SEE SIGNIFICANT DIFFERENCES AS WE HEAD INTO THE WEEKEND WITH GFS BEING TYPICALLY MORE PROGRESSIVE AND EURO DIGGING IN ITS HEELS. BY MONDAY UPPER RIDGE AXIS SHOULD BE CROSSING THE REGION AS NEXT SOUTHERN STREAM CLOSED LOW APPROACHES FROM THE LOWER MISSISSIPPI VALLEY. EVEN WITH THE MODEL DIFFERENCES...IMPACTS ON SENSIBLE WEATHER ELEMENTS THROUGH THE EXTENDED WILL BE SMALL. NW FLOW UPSLOPE SNOW SHOWERS ACROSS THE FAR WRN SLOPES OF THE BLUE RIDGE WILL BE WINDING DOWN THURSDAY NIGHT AS SFC HIGH SLIDES IN FROM THE WEST. MAYBE SOME FLURRIES FAR WRN SLOPES THROUGH THE END OF THE WEEK...BUT LOOKING LIKE QUIET WEATHER ELSEWHERE. WE THEN GET INTO SOME WEAK LIFT AS A LIGHT WARM AIR ADVECTION PATTERN SETS UP SATURDAY NIGHT THROUGH SUNDAY. THIS MAY BE ENOUGH TO GET SOME SPRINKLES GOING BUT NOTHING TOO EXCITING...AND GIVEN THE MODEL UNCERTAINTY THIS FAR OUT WILL GO WITH POPS NO HIGHER THAN SLIGHT CHC CONFINED TO WEST OF THE BLUE RIDGE. EXPECT A WARMING TREND FROM BELOW NORMAL FRIDAY TO ABOVE NORMAL BY THE START OF NEXT WEEK. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/... AS OF 650 AM EST TUESDAY... FOLLOWED A BLEND OF THE SREF AND NAM THIS MORNING WITH TRENDS TOWARD VFR BY LATE MORNING FROM ROA EAST...THOUGH DAN MAY TAKE UNTIL 18Z TO GO VFR. MEANWHILE...NW FLOW AND UPPER LOW WILL BE KEEPING CIGS MVFR OR WORSE OVER THE MTNS. HAVE POCKETS OF DENSE FOG AT BLF...WITH MVFR FOG AT LWB/BCB. THINK THE FOG WILL CLEAR OUT SOON...LEAVING BEHIND AN MVFR CIG...AT BLF/LWB...WITH BCB GOING TO VFR FOR A FEW HOURS THIS AFTERNOON. AS THE UPPER LOW MOVES ACROSS TO OUR SOUTH AND EAST THIS AFTERNOON LOOK FOR RAIN AND SNOW SHOWERS TO INCREASE FOR SE WV INTO THE NC MTNS. WILL HAVE BLF STAYING MVFR THROUGH THE PERIOD CHANGING TO ALL SNOW BY 02Z TONIGHT. COULD SEE SOME CIGS DROP BELOW 1KFT. LWB IS GOING TO ALSO BE MVFR...THOUGH A SMALL WINDOW OF VFR CIGS MAY OCCUR THIS AFTERNOON BEFORE THE NW FLOW GETS GOING. BCB MAY SEE A FEW FLURRIES TONIGHT WHILE CIGS DROP BACK TO JUST UNDER 3KFT. WINDS SHOULD ALSO PICK UP LATER TODAY AND ESPECIALLY LATE TONIGHT AS THE LOW OFF THE MID ATLANTIC COAST DEEPENS. SOME GUSTS OVER 20 KTS POSSIBLE BY WED MORNING. EXTENDED DISCUSSION... SNOW SHOWERS AND MVFR UPSLOPE CLOUDS WILL CONTINUE IN SOUTHEAST WEST VIRGINIA THROUGH THURSDAY MORNING. VFR CONDITIONS ARE EXPECTED IN THE EAST. GUSTY WINDS ARE LIKELY THROUGH WEDNESDAY NIGHT. THURSDAY NIGHT THROUGH SATURDAY...ASIDE FOR SOME LINGERING MVFR CLOUDINESS IN THE WV MOUNTAINS THURSDAY...HIGH PRESSURE WILL BUILD OVER THE MID ATLANTIC THURSDAY THROUGH SATURDAY WITH VFR AND DIMINISHING WINDS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 8 AM EST THIS MORNING FOR VAZ019- 020-023-024-034-035. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...WP SHORT TERM...KK LONG TERM...MBS AVIATION...AMS/PM/WP
AREA FORECAST DISCUSSION
NWS TAUNTON MA
144 PM EST TUE DEC 9 2014 .SYNOPSIS... A SIGNIFICANT COASTAL STORM WILL IMPACT THE REGION TODAY WITH WINTRY PRECIPITATION AND HEAVY RAIN...ALONG WITH STRONG TO DAMAGING WINDS. LEFTOVER LIGHT SNOW AND RAIN SHOWERS MAY PERSIST INTO SATURDAY AS THE DISTURBANCE ALOFT STALLS ACROSS NEW ENGLAND. IMPROVING CONDITIONS EXPECTED SUNDAY AND ESPECIALLY EARLY NEXT WEEK AS HIGH PRES BUILDS IN FROM THE WEST. && .NEAR TERM /THROUGH TONIGHT/... 1040 AM UPDATE... TEMPS HAVE BEEN SLOWLY BUT STEADILY RISING ACROSS E MA/RI/NE CT THROUGH 15Z...BUT HOLDING RIGHT AROUND FREEZING FROM THE INTERIOR MERRIMACK VALLEY THROUGH CENTRAL AND NW MA. NOTING THAT TEMPS HAVE BEEN WARMING ALOFT WITH RATHER STRONG LOW LEVEL INVERSION AS SEEN ON 12Z KOKX SOUNDING /UP TO +5C AT 866 MB AND FREEZING LEVEL UP TO 6500 FT/...SO TENDING TO MIX DOWN WITH THE AREA OF HEAVY RAINFALL MOVING INTO S COASTAL AREAS. THIS WILL HELP TEMPS RISE EVEN ACROSS INLAND AREAS AS THE SLUG OVER HEAVY PRECIP MOVES IN. NOTING 1005 HPA LOW PRES JUST NE OF THE DELMARVA PENINSULA AT 15Z...WHICH APPEARS PRETTY MUCH ON TRACK THOUGH TUCKED A BIT CLOSER TO THE COAST. NOTING REPORTS OF 0.75 TO 1 INCH/HR RAINFALL RATES ACROSS S CT AND LONG ISLAND OVER THE LAST HOUR OR TWO. THIS...ALONG WITH GUIDANCE FROM NESDIS SATELLITE PRECIP ESTIMATE REPORTING A MAX PWAT PLUME OF 1.65 INCHES WELL S OF LONG ISLAND EARLIER THIS MORNING. VERY COLD CLOUD TOPS ALSO NOTED S OF LONG ISLAND. DRY SLOT NOTED ON NE REGIONAL 88D RADAR E OF KACY...WHICH WILL SLOWLY SHIFT N-NE DURING THE DAY. ALSO NOTED 06Z GFS OP RUN SUGGESTING UP TO 1.5 TO 2 INCH RAINFALL RATES IN TWO 6-HOUR PERIODS BETWEEN NOW AND 00Z MOVING ACROSS RI/E MA. CONSIDERING THE NESDIS OBSERVATIONS...FELT THIS WAS NOT TOO BAD SO UPDATED TO INCREASE PRECIP AMOUNTS. THIS GIVES STORM TOTAL PRECIP OF 2.5 TO 3.5 INCHES...WHICH MAY LEAD TO LOCALIZED URBAN AND POOR DRAINAGE FLOODING ACROSS RI/E MA. HAVE UPDATED FORECAST TO INCLUDE HEAVY RAINFALL MENTION TO THE FORECAST. WILL ALSO MONITOR FOR THE CHANCE OF ANY THUNDER THAT MAY NEED TO BE ADDED ACROSS S COASTAL RI/MA. NOTING C/G LIGHTNING TO THE E OF THE DRY SLOT. ALSO UPDATED TEMPS/DEWPTS TO BRING CONDITIONS CURRENT. REMAINDER OF FORECAST IN PRETTY GOOD SHAPE. PREVIOUS DISCUSSION... * SYNOPTICALLY... PRESENT OFFSHORE LOW OFF THE MID-ATLANTIC CONUS BECOMES USURPED BY AN AMPLIFYING TROUGH DIGGING THROUGH THE E-CONUS. ACROSS A REGION OF FAVORABLE BAROCLINICITY / ATTENDANT DYNAMICS / STRONG FORCING AND DEEP-LAYER ASCENT YIELDS A RAPIDLY DEEPENING AREA OF LOW PRESSURE OFF THE DELMARVA PENINSULA THIS MORNING LIFTING N INTO S NEW ENGLAND BY EVENING. THE LOW BECOMES STALLED AND CUTOFF FROM THE MEAN FLOW UP AGAINST HIGH PRESSURE ON NEARLY ALL SIDES AS WE GO INTO THE WEEK. * HEAVY RAIN AND FLOODING... AS THE LOW DEEPENS...EXPECT DECENT LOW-LEVEL TROWALING OF THE WARM-CONVEYER-BELT BENEATH THE RRQ/LFQ OF ATTENDANT UPPER-LEVEL JET AXES. COMBINATION OF THE CONVERGENT LEADING NOSE OF ISENTROPIC UPSLOPE LENDING TO THE TIGHTENING OF THE THERMAL GRADIENT AGAINST NEIGHBORING HIGH PRESSURE YIELDING STRONG FRONTOGENETICAL FORCING IN A REGION OF MINOR -EPV INSTABILITY BENEATH AFOREMENTIONED DEEP LAYER ASCENT LIKELY TO RESULT IN A ROUGHLY W-E BANDING SETUP OF HIGHER WSR-88D RETURNS WITHIN A WIDESPREAD COMMA-SHAPED PRECIP FIELD ALONG THE N-PERIPHERY OF THE H85 LOW WITH THE FRONT-END THUMP OF PRECIP ANTICIPATED AROUND MIDDAY AND PERSISTING INTO EARLY EVENING. WILL EXPAND THE FLOOD WATCH TO INCLUDE CAPE COD AND NANTUCKET. WITH HEIGHT OF THE E-NE WINDS AND HEAVY RAIN CONCURRENT WITH TIMING OF HIGH TIDE CENTERED AROUND 1 PM BELIEVE SURGE ALONG WITH BUILDING WAVE HEIGHTS /SEE THE MARINE DISCUSSION BELOW FOR MORE DETAILS/ WILL RESULT IN POOR-DRAINAGE ISSUES FOR COASTAL COMMUNITIES. ANTICIPATE DRAINS TO BACK-UP BECOMING OVER-TOPPED RESULTING IN SUSCEPTIBLE LOW- LYING AND POOR-DRAINAGE AREAS TO BECOME FLOODED. AM ALSO CONCERNED FOR EVEN THOSE COMMUNITIES WITHIN THE COASTAL PLAIN IN VICINITY OF RIVERS THAT ARE INFLUENCED BY THE TIDE /I.E. TAUNTON RIVER...LOWER CONNECTICUT/. COULD ALSO SEE SOME EXACERBATED FLOOD ISSUES FOR THESE AREAS. OTHERWISE REMAINDER OF THE FLOOD WATCH REMAINS IN PLACE. PWATS OF 1.25-INCHES FORECAST /ROUGHLY +2 STANDARD DEVIATIONS ABOVE-NORMAL/ AND FORECAST RAINFALL AMOUNTS OF 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS ANTICIPATED. GROUND IS PRETTY SOLID /IMPERVIOUS/ THUS EXPECT MOST OF THE RAINFALL TO BECOME RUNOFF. MAJORITY OF MAINSTEM RIVERS OVER THE INTERIOR SHOULD BE ABLE TO HANDLE THE RAIN...SO CONCERNS LIE IN THE REALM OF URBAN / POOR DRAINAGE FLOODING...ESPECIALLY IF DRAINS ARE STILL LEAF-CLOGGED. BIGGEST AREA OF CONCERN IS WITHIN THE METRO-AREA CORRIDORS...ESPECIALLY BOSTON-PROVIDENCE. MAY NEED TO EXPAND THE WATCH ACROSS N-CENTRAL AND NW MA PENDING THE TIMING AT WHICH WINTRY-PRECIP TYPES TRANSITION TO RAIN. * WINTRY PRECIPITATION... OUTCOMES DEPENDENT ON THERMAL FIELDS ALOFT...WHERE AROUND H925-H85 BY MORNING CONDITIONS ARE WARMING CONSIDERABLY UP AGAINST COLDER AIR AND HIGH PRESSURE SITUATED N/W. A SW-NE FREEZING LINE AROUND NW-CT INTO S NH INITIALLY MODIFIES NW AS THE LOW DEEPENS RESULTING IN THE INCREASE OF THE SE WARM-MOIST-CONVEYER-BELT. EXPECT THICKNESSES TO GRADUALLY RISE DURING THE HEIGHT OF THE EVENT INTO EVENING. AT THE SURFACE...AREAS BELOW FREEZING ERODE WITH INCREASING ONSHORE E/NE-WINDS DURING THE MORNING /MORE ON THAT LATER/. UNCERTAINTY CONTINUES WITH 09.0Z HIGH-RES MODELS DIFFERING IN TIMING OF EROSION. AS MENTIONED IN PRIOR DISCUSSIONS...FOR AREAS THAT ARE WITHIN OR ON THE CUSP OF BELOW-FREEZING TEMPERATURES BY 1-2C...LINGERING AN HOUR OR TWO MORE OR LESS CAN MAKE ALL THE DIFFERENCE WITH REGARDS TO WINTER-WEATHER HEAD-LINES. H975-925 AGEOSTROPHIC FLOW IS NOTABLY PERSISTENT AND STRONG OUT OF THE W AS THE LOW INTENSIFIES TOWARDS S NEW ENGLAND. BUT NOT MUCH OF A N-COMPONENT NOR FROM ARCTIC-SOURCE REGIONS...SO BELIEVE THIS WILL DO LITTLE TO MAINTAIN / PERSIST COLD AIR OVER THE REGION AGAINST STRONG ONSHORE E-FLOW. WILL GO CLOSE TO THE NEAR-TERM HIGH-RES GUIDANCE WHILE INCORPORATING THE WRF-NMM WITH REGARDS TO THERMAL FIELDS...WHICH ARE HANDLING THE SURFACE TEMPERATURES DECENTLY. PREFERENCE TO THE 09.0Z ECMWF IS ALSO GIVEN ESPECIALLY WHEN EVALUATING H100-H85 THICKNESSES. ONLY WRF-ARW AND RAP LEAN ON THE WARM SIDE OF THE GUIDANCE OVER ALL OTHERS. ALSO WILL GO WITH A TOP-DOWN APPROACH TOWARDS PRECIPITATION-TYPE THAT INCORPORATES THE INCREASING MOISTURE FROM THE S WITHIN OR ABOVE THE DENDRITIC GROWTH ZONE REGION. SO OVERALL...EXPECTING THE GRADUAL EROSION OF THE COASTAL-FRONT WITH INCREASING ONSHORE E-FLOW. PUSH OF WARMER AIR ALOFT AHEAD OF THE DEEPENING LOW WILL RESULT IN PRECIP-TYPE TRANSITION FAIRLY QUICKLY TO A SLEET / FREEZING RAIN MIX. THIS HAS SUBSEQUENTLY BUMPED DOWN SNOWFALL AMOUNTS RESULTING IN A RANGE OF 2-4 INCHES ACROSS NW MA. MOST OF THE REGION CHANGES OVER TO RAIN BY LATE MORNING INTO MIDDAY WITH ONLY THE HIGHER ELEVATIONS OF THE BERKSHIRES CONTINUALLY UNDER THE THREAT OF FREEZING RAIN. HAVE DROPPED WINTER-STORM WATCHES AND REPLACED WITH WINTER WEATHER ADVISORIES. HAVE TRIMMED THE EASTERN-EXTENT WITH EROSION OF THE COASTAL FRONT AND THE SURGE OF WARMER AIR ONSHORE. AGAIN...THE THERMAL FIELDS DISCUSSION ABOVE GIVE AN INDICATION OF PREFERRED MODEL GUIDANCE. SHOULD SEE WINTER WEATHER HEADLINES DROP MAINLY AROUND THE MIDDAY HOURS. MID-LEVEL DRY-SLOT WRAPPING INTO A DEVELOPING OCCLUSION BEGINNING TUESDAY EVENING SHOULD RESULT IN A LULL OF PRECIPITATION AS WE GO INTO WEDNESDAY MORNING. * STRONG TO DAMAGING WINDS... NOTING E-WINDS 1-2 KFT AGL WILL BE AROUND 55 MPH AROUND THE MIDDAY INTO AFTERNOON HOURS...THE PRESENCE OF WARMER AIR ALOFT LENDING TO AN INVERSION JUST ABOVE THE SURFACE MAKES IT DIFFICULT TO CONSIDER A HIGH WIND WARNING. THIS DESPITE WARMER AIR WIGGLING ITS WAY UP FROM THE S AT THE SURFACE...AND A WARMER OCEAN /THOUGH NOW AROUND THE LOW- 50S/. BOUNDARY-LAYER MIXING WILL BE LIMITED. HIGH-END WIND ADVISORY CRITERIA IS EXPECTED...BUT DO NOT EXPECT WIDESPREAD GUSTS EXCEEDING HIGH WIND WARNING CRITERIA. THUS WENT WITH THE WIND ADVISORY. COULD PRECIPITATION-DRAG PROCESSES BRING FASTER MOMENTUM TO THE SURFACE? YES...IT IS QUITE POSSIBLE...EVEN IF THUNDERSTORMS ARE IN THE MIX WHICH IS IN THE FORECAST FOR THE FAR SE-WATERS ADJACENT TO THE CAPE AND ISLANDS. HAVE GONE WITH THE HEADLINES THAT CONVEY THE HIGHEST CONFIDENCE. * COASTAL FLOODING... SEE TIDES/COASTAL FLOODING SECTION BELOW FOR DETAILS. && .SHORT TERM /WEDNESDAY/... SEE LONG TERM SECTION BELOW. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... HIGHLIGHTS... * REMAINING UNSETTLED WITH SCT RAIN/SNOW SHOWERS THROUGH THE END OF THE WEEK AND POSSIBLY INTO SAT * IMPROVING CONDITIONS SUNDAY AND ESPECIALLY EARLY NEXT WEEK CLOSED LOW WILL MEANDER ACROSS NEW ENG THROUGH THE END OF THE WEEK AND LIKELY INTO THE WEEKEND AS NORTH ATLANTIC BLOCKING IS VERY SLOW TO BREAK DOWN. TYPICALLY THESE BLOCKS ARE SLOWER TO BREAK DOWN THAN GUIDANCE SUGGESTS SO THREAT OF SCT RAIN/SNOW SHOWERS WILL LIKELY PERSIST INTO SATURDAY. CERTAINLY NOT LOOKING AT WIDESPREAD PRECIP AND MOST OF THE TIME WILL BE DRY...BUT THERE WILL BE SCT RAIN/SNOW SHOWERS AT TIMES AS COLD POOL ALOFT WITH 500 MB TEMPS -25 TO -30C AND DEEPER MOISTURE AXIS WILL BE PRESENT INTO SATURDAY. LOW PREDICTABILITY ON TIMING OF ANY SHOWERS...BUT DURING WED NIGHT SNE WILL BE ON SE EDGE OF COMMA HEAD AND QG FORCING OVER NNY AND THERE IS POTENTIAL FOR SOME MINOR SNOW ACCUM ACROSS WESTERN MA. IMPROVING CONDITIONS EXPECTED BY SUNDAY AND ESPECIALLY EARLY NEXT WEEK AS THE CLOSED LOW AND COLD POOL ARE FINALLY FORECAST TO MOVE AWAY FROM THE NEW ENG WITH SFC AND UPPER LEVEL RIDGING BUILDING IN AND GOOD DRYING IN THE LOW AND MID LEVELS. BY NEXT TUESDAY...NEXT NORTHERN STREAM SHORTWAVE WILL BE APPROACHING AND WE COULD HAVE A FRONTAL PASSAGE WITH A LOW PROB OF SHOWERS. WE USED A BLEND OF AVAILABLE GUIDANCE. LOOKING AT SLIGHTLY BELOW TEMPS THROUGH THE WEEKEND...MODERATING A BIT EARLY NEXT WEEK. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY MORNING/... 12Z UPDATE... TODAY INTO TONIGHT...MODERATE CONFIDENCE. MIX OF MVFR-IFR CIGS / VSBYS WITH MAINLY +RA. AN ISOLATED TSRA IS POSSIBLE FOR FAR SE-COASTAL TERMINALS. OTHERWISE GRADUAL EROSION TO N/W OF FZRA/PL/SN INTO THE EARLY-AFTERNOON HOURS DURING WHICH TIME WINDS WILL INCREASE OUT OF THE E WITH STRONGEST GUSTS ALONG THE E-SHORELINE MAINLY AROUND 40 KT WITH LOCALLY HIGHER GUSTS UP TO 50 KT. WILL ALSO SEE AN ACCOMPANYING LLWS THREAT WITH WINDS AROUND 2 KFT AGL OUT OF THE E AROUND 60 KTS. KBOS TERMINAL...MODERATE CONFIDENCE. FEEL CONFIDENT WITH TRENDS BUT NOT SO MUCH WITH SPECIFICS. HIGH CONFIDENCE OF CONTINUED +RA WITH INCREASING E-WINDS. GUSTS UP TO 40 KT ANTICIPATED TOWARDS THE MIDDAY HRS. WIND ADVISORY LENDING TO ISSUANCE OF AIRPORT WEATHER WARNING. KBDL TERMINAL...MODERATE CONFIDENCE. FZRA PERSISTING INTO THE EARLY-MORNING HOURS...THEN CHANGING OVER TO RAIN. NOT ABSOLUTELY CERTAIN ON TIMING BUT CONFIDENT WITH TRENDS. OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY... WEDNESDAY NIGHT AND THURSDAY...MODERATE CONFIDENCE. AREAS OF MVFR/IFR IN SCATTERED RAIN/SNOW SHOWERS. FRIDAY AND SATURDAY...MODERATE CONFIDENCE. MIX OF VFR CIGS AND MVFR. ISOLATED RAIN/SNOW SHOWERS. SUNDAY...MODERATE CONFIDENCE. VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE. 1030 AM UPDATE... THROUGH THIS AFTERNOON NOTING SEAS HAVE INCREASED TO 10-15 FT ON THE OUTER WATERS AND EVEN PUSHING INTO MASS BAY ON THE E FETCH. HAVE UPDATED TO INCREASE THE SEAS TO AT LEAST THESE LEVELS. EXPECT STRONGEST WINDS TO PUSH INTO THE WATERS. GUSTS UP TO 33 KT REPORTS AT BUOY 44020 /NANTUCKET SOUND/ AND 31 KT AT BOTH MASS BAY BUOYS WITH 35 KT GUSTS AT THE BUZZARDS BAY TOWER AT 15Z. FORECAST THROUGH TODAY PRETTY MUCH ON TRACK. PREVIOUS DISCUSSION... HAVE GONE WITH STORM WARNINGS FOR THE OUTER WATERS WITH THE EXPECTATION OF GUSTS AROUND 45-50 KT. BUT GREATER CONFIDENCE OF THE INNER WATERS REACHING HIGH-END GALE WARNING CRITERIA PERMITTED THE DISCONTINUING OF THE STORM WATCH. CAN NOT RULE OUT AN ISOLATED GUST UP TO 50 KTS OVER THE INNER WATERS...BUT WITH IT NOT ANTICIPATED TO BE WIDESPREAD...KEPT WITH GALE WARNINGS. STRONGEST E-WINDS OCCURRING TOWARDS THE MIDDAY AND CONTINUING INTO THE EARLY EVENING HOURS. SEAS BUILDING 15 TO 20 FEET WITH INCREASING E WINDS AHEAD OF A DEEPENING AREA OF LOW PRESSURE OF THE DELMARVA PENINSULA PRESENTLY AS IT LIFTS N INTO S NEW ENGLAND TOWARDS THIS EVENING. EXPECT ACCOMPANYING HEAVY RAIN WHICH WILL YIELD VISIBILITY RESTRICTIONS ON THE WATERS. OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...MODERATE CONFIDENCE. WEDNESDAY NIGHT AND THURSDAY...EXPECT MOSTLY SW WINDS WITH GUSTS TO 25 KT...ESPECIALLY S WATERS AS LOW PRES MOVES SLOWLY N THROUGH NEW ENG. ROUGH SEAS CONTINUE...UP TO 10-11 FT SOUTHERN WATERS. FRIDAY INTO SATURDAY...GRADIENT RELAXES AND EXPECT DIMINISHING WIND AND SEAS. WEST WINDS FRI GRADUALLY VEERING TO NORTH BY SAT. SEAS SUBSIDING BELOW SCA BY SAT. SATURDAY NIGHT AND SUNDAY...NORTHERLY WINDS EXPECTED TO INCREASE A BIT AS GRADIENT INCREASES. CHANCE FOR GUSTS TO 25 KT...ESPECIALLY E WATERS. && .HYDROLOGY... UPDATED 950 AM TUE... EXPANDED FLOOD WATCH TO INCLUDE MARTHAS VINEYARD AND BLOCK ISLAND. ALTHOUGH RAINFALL TOTALS WILL BE 1.5 TO 2.5 INCHES...COMBINATION OF RAINFALL AND RISING TIDE THROUGH EARLY AFTERNOON MAY LEAD TO SIGNIFICANT FLOODING ESPECIALLY ON E/SE SHORELINES. BUOYS REPORTING 5-6 FT SEAS ON NANTUCKET SOUND AND 11 FT SE OF BLOCK ISLAND. SIMILAR SITUATION FOR CAPE COD AND NANTUCKET. MAIN CONCERN CONTINUES TO BE POTENTIAL FOR SIGNIFICANT URBAN FLOODING...ESPECIALLY IN RI AND E MA. ALREADY SEEING RAINFALL RATES OF NEARLY 2 INCHES PER HOUR ACROSS SOUTHERN CT /KSNC ASOS/ WHICH WILL TRANSLATE OVER OUR AREA BY EARLY AFTERNOON. SOME OF THE URBAN HOT SPOTS SUCH AS PEABODY...FALL RIVER...NEW BEDFORD AND CRANSTON MAY BE ESPECIALLY VULNERABLE TO FLOODING. TOTALS OF 2 TO 3 INCHES ARE EXPECTED WITH A FEW 3 OR 4 INCH TOTALS NOT OUT OF QUESTION NEAR I-95 CORRIDOR. FLOODING OF SMALL STREAMS IS ALSO A POSSIBILITY...BUT WORST CASE WOULD BE FOR MINOR FLOODING IF TOTALS EXCEED 3 INCHES. NOT EXPECTING FLOODING OF LARGER RIVERS. LATEST NERFC GUIDANCE BRINGS LOWER CT RIVER AT MIDDLE HADDAM TO ACTION STAGE...WHICH IS PRIMARILY BASED ON SURGE OF 2 FT INTO LOWER CT RIVER. WE MAY ALSO SEE SIMILAR SURGE ALONG PAWCATUCK RIVER NEAR WESTERLY RI WHICH COULD BRING RISES SLIGHTLY HIGHER THAN CURRENTLY FORECAST. && .TIDES/COASTAL FLOODING... COASTAL FLOOD ADVISORY CONTINUES FOR EASTERN MA. COMBINATION OF WINDS / SEAS / SURGE OF AROUND 1.5 TO 2 FEET DURING THE MIDDAY HIGH-TIDE YIELDS THE LIKELIHOOD OF OBSERVING MINOR COASTAL FLOODING AND BEACH EROSION FOR E-FACING SHORELINES WHERE SEAS OF 12 TO 15 FEET ARE POSSIBLE. AS NOTED IN THE HYDROLOGY PORTION ABOVE...LOCAL STREAMS AND TRIBUTARIES EMPTYING INTO THE SEA COULD SEE BACK-FILLING ISSUES AS THE HEAVY RAIN IS ANTICIPATED DURING THE TIME OF HIGH-TIDE. COULD SEE FLOODING ISSUES EXACERBATED FOR EASTERN MA SHORELINE COMMUNITIES. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH UNTIL 1 AM EST WEDNESDAY FOR CTZ002>004. MA...FLOOD WATCH UNTIL 1 AM EST WEDNESDAY FOR MAZ005>007-011>024. WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MAZ007-014>016- 019>024. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ007-015-016-019-022-024. RI...FLOOD WATCH UNTIL 1 AM EST WEDNESDAY FOR RIZ001>008. WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR RIZ006>008. MARINE...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ230>234-251. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ235>237. STORM WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ250-254>256. && $$ SYNOPSIS...KJC NEAR TERM...EVT SHORT TERM...SIPPRELL LONG TERM...KJC AVIATION...KJC/EVT MARINE...KJC/EVT HYDROLOGY...STAFF TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS ALBANY NY
1240 PM EST TUE DEC 9 2014 .SYNOPSIS... A SLOW MOVING COASTAL STORM WILL BRING A VARIETY OF WINTER WEATHER TO THE REGION FOR TODAY INTO TONIGHT. WHILE MANY VALLEY AND EASTERN AREAS WILL SEE A TRANSITION OF A WINTRY MIX TO RAIN...THE PRECIPITATION WILL BE MAINLY SNOW ACROSS THE CATSKILLS AND ADIRONDACKS...WITH A MODERATE TO HEAVY ACCUMULATION POSSIBLE IN THESE HIGH TERRAIN AREAS. WITH THE STORM REMAINING CLOSE TO THE REGION...SOME ADDITIONAL RAIN AND SNOW WILL OCCUR WEDNESDAY INTO THURSDAY AS WELL...WITH SOME ADDITIONAL SNOW ACCUMULATION POSSIBLE. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1014 AM EST...A 1004 HPA COASTAL LOW CONTINUES TO BE JUST E/SE OF THE DELMARVA REGION THIS MORNING ACCORDING TO THE LATEST MSAS MSLP ANALYSIS. THE BEST 3-HR MSLP /5-6 HPAS/FALLS ARE NORTH OF THE SFC CYCLONE. THE LATEST KENX VWP SHOWS A STRONG E/SE LLJ IN THR 3-6 KFT AGL LAYER OF 25-35 KTS. THIS PRONOUNCED LLJ HAS YIELDED SOME SIGNIFICANT DOWNSLOPING OFF THE SRN GREENS...NRN BERKS...AND THE NRN TACONICS. THE PCPN IS FINALLY TRYING TO EXPAND NORTHWARD INTO THE UPPER HUDSON REGION...AND SRN VT. THE SRN DACKS ARE ALSO SLOWLY...BUT FINALLY...GETTING INTO A THE PCPN SHIELD. THE LLJ CONTINUES TO INTENSIFY JUST S/SE OF THE REGION...AND THE BEST QG LIFT WITH THE EARLY PHASES OF THE STORM IS OVER COASTAL SRN NEW ENGLAND AND LONG ISLAND AT THIS TIME. THE STRONG LIFT WILL IMPACT THE REGION IN THE AFTERNOON. PTYPES HAVE FAVORED SLEET AND FREEZING RAIN THIS MORNING. THE 12Z KALY SOUNDING INDICATES A SLEET PROFILE. SOME HAS OCCURRED IN THE CAPITAL DISTRICT WITH THE FREEZING RAIN/DRIZZLE. SOME ICE REPORTS HAVE COME IN...WITH PERU IN THE S-CNTRL BERKS HAVING TWO TENTHS OF AN INCH. THE COLUMN CONTINUES TO WARM WITH KPOU ABOVE FREEZING WITH LIGHT RAIN...WHICH SHOULD TRANSITION TO MDT-HVY RAIN OVER THE NEXT HOUR OR TWO. WE WILL LET THE ADVISORY RUN UNTIL 11 AM...FOR ERN ULSTER/DUTCHESS/LITCHFIELD COUNTIES...AS SOME TEMPS ARE SLIGHTLY BELOW OR ARE HOVERING NEAR THE FREEZING MARK. FURTHER NORTH...THE DOWNSLOPING HAS ALLOWED KPSF/KAQW/KDDH TO ALLOW JUMP ABOVE FREEZING INTO THE MID AND U30S. SOME WET BULB COOLING SHOULD LOWER THESE TEMPS CLOSER TO FREEZING. PTYPES WERE ATTEMPTED TO BE ADJUSTED ACCORDING THE HOURLIES AND A GFS/ECMWF BLEND. MIXED PCPN WILL LIKELY LINGER FOR THE CAPITAL REGION...N-CNTRL TACONICS...BERKSHIRES...AND SRN VT INTO THE AFTERNOON BEFORE CHANGING TO RAIN. FURTHER NORTH AND WEST WILL HAVE THE BEST CHC OF SNOW...WITH A LIGHT MIXED TO SLEET/FREEZING RAIN/RAIN...BEFORE GOING BACK TO SNOW OVERNIGHT...BUT THIS WILL CONTINUE TO BE FINED TUNED. SOME OF THE PREVIOUS DISCUSSION FOLLOWS FOR THIS AFTERNOON AND TONIGHT... THERE WILL BE A SHARP CUTOFF BETWEEN SNOW VS. WINTRY MIX VS. RAIN. THE 3KM HRRR SHOWS THAT SNOW SHOULD ACCUMULATE ACROSS THE CATSKILLS/HELDERBERGS AND POINTS WESTWARD INTO THIS AFTERNOON. FURTHER NORTH...THE PRECIP WILL EXPAND INTO THE WRN MOHAWK VALLEY AND ADIRONDACKS BY THE EARLY AFTN HOURS. PRECIP LOOKS TO BE MAINLY SNOW FOR THE MOHAWK VALLEY/ADIRONDACKS...BUT WILL LIKELY MIX FOR THE SARATOGA/GLENS FALLS AREA. EVEN UP THERE...A CHANGEOVER TO RAIN LOOKS TO OCCUR DURING THE AFTN HOURS...AS WARM AIR...BOTH AT THE SFC AND ALOFT...WILL BE MOVING INTO THE AREA. FURTHER EAST...THE PRECIP WILL CHANGE TO A WINTRY MIX FOR SOUTHERN VT/BERKSHIRES AS WELL...EVEN ACROSS THE HIGH TERRAIN...AS WARM AIR ALOFT OF NEARLY 3 DEGREES C MOVES OVER THE AREA FROM THE EAST. SOME SNOW/SLEET WILL LIKELY ACCUMULATE BEFORE THE CHANGEOVER...BUT THE CHANGEOVER WILL PREVENT WARNING LEVEL SNOW FROM OCCURRING. SOME STRONG WINDS ARE POSSIBLE ACROSS THE SRN GREENS...TACONICS AND BERKSHIRES...WITH SOME GUSTS OF 25-40 MPH POSSIBLE. THE FULL BRUNT OF THE LOW LEVEL JET DOESN/T LOOK LIKE IT WILL BE ABLE TO MIX DOWN DUE TO STABLE LOW LEVELS...BUT SOME GUSTS ARE STILL POSSIBLE...ESP IN AREAS THAT CHANNEL E-SE FLOW WELL. WE WILL CONTINUE TO MENTION THIS WIND THREAT IN OUR HWO STATEMENT. AS THE BEST ISENTROPIC LIFT SHIFTS NORTH AND EAST OF THE REGION THIS EVENING...STEADY PRECIP WILL START TO SHUT OFF ACROSS OUR AREA. THE SFC LOW WILL BE MEANDERING OVER THE NYC/LONG ISLAND AREA...AND THE 500 HPA LOW WILL BECOME CUTOFF OVER THE DELMARVA AREA. AS A RESULT...SOME ADDITIONAL ON AND OFF PRECIP WILL OCCUR OVERNIGHT DUE TO THE PVA/CYCLONIC FLOW...BUT IT WILL NOT BE STEADY OR HEAVY. THERE WILL STILL BE SOME ABOVE FREEZING TEMPS ALOFT...AND THERE MAY EVEN BE A LACK OF ICE NUCLEI IN THE CLOUDS...AS THE BEST DEEPER AND COLDER CLOUD TOPS SHIFT AWAY FROM THE AREA. BECAUSE OF THIS...SOME FREEZING RAIN/DRIZZLE MAY OCCUR...ALONG WITH SOME BURSTS OF SNOW/RAIN/SLEET AS WELL. TEMPS LOOK TO HOLD STEADY IN THE LOW TO MIDDLE 30S ACROSS THE ENTIRE REGION. BECAUSE OF ALL OF THIS...WINTER STORM WARNINGS WERE NOT ISSUED OUTSIDE THE CATSKILLS/MOHAWK AND SCHOHARIE VALLEY/ADIRONDACKS BECAUSE WARNING LEVEL SNOWFALL /7 INCHES IN 12 HOURS OR 9 INCHES IN 24 HOURS/ IS NOT EXPECTED. STILL...A WINTRY MIX...EVEN THOUGH IT WILL GO OVER TO RAIN...WILL MAKE FOR HAZARDOUS TRAVEL IN THE CAPITAL REGION/GLENS FALLS AND SARATOGA AREAS/BERKSHIRES/SOUTHERN VT/...AND THIS IS WHY THE WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THESE LOCATIONS. SNOW ACCUMULATION IN THESE AREAS WILL VARY BASED ON ELEVATION...WITH JUST UP TO A FEW INCHES IN THE VALLEY AREAS...AND 2 TO 6 INCHES ACROSS THE HIGH TERRAIN. JUST A COATING TO AN INCH OF SNOW/SLEET/ICE IS EXPECTED FOR THE POUGHKEEPSIE/KINGSTON AREA AND NW CT...AS PRECIP SHOULD QUICKLY GO OVER TO RAIN THERE THIS MORNING. HOWEVER...THE FLOOD WATCH REMAINS IN EFFECT...AS HEAVY RAINFALL MAY LEAD TO SOME FLOOD CONCERNS. SEE OUR HYDRO DISCUSSION FOR MORE DETAILS ON THIS THREAT. MEANWHILE... 6 TO 12 INCHES LOOK TO ACCUMULATE IN THE CATSKILLS...HELDERBERGS...MOHAWK AND SCHOHARIE VALLEYS...AND ADIRONDACKS. EVEN IN THESE AREAS...SOME SLEET/FREEZING RAIN IS POSSIBLE AT TIMES...AND VALLEYS WILL BE ON THE LOWER END OF THE RANGE...WITH THE HIGHEST AMOUNTS IN THE HIGH PEAKS OF THE CATSKILLS IN THE GREENE COUNTY...AND IN THE HIGHEST PEAKS OF THE SRN ADIRONDACKS OF WARREN COUNTY. THE SNOW WILL BE RATHER WET...AND THIS MAY MAKE FOR SOME POWER OUTAGES/DOWNED TREE LIMBS...ESP CONSIDERING THAT STRONG NORTH WINDS ARE EXPECTED. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... A NEARLY VERTICALLY STACKED LOW OVER NEW ENGLAND WILL KEEP OUR WEATHER UNSETTLED THROUGH THE SHORT TERM PERIOD. WHILE DIFFICULT TO ASCERTAIN WHAT WAVE/S/ WILL TRIGGER ADDITIONAL PRECIPITATION...MOISTURE WILL WRAP IN OFF THE ATLANTIC TO KEEP THE HIGH PROBABILITIES IN THE FORECAST. THE BEST LOCATIONS WILL BE ALONG THE I90 CORRIDOR AND POINTS NORTHWARD. AS FOR THERMAL PROFILES...WE WILL BE COOLING DOWN THE COLUMN WHERE MOST OF THIS PRECIPITATION WILL BE IN THE FORM OF SNOW. THERE WILL BE SOME RAIN/SNOW MIXTURE INTO THE VALLEY LOCATIONS DURING THE LATE MORNING INTO THE MID AFTERNOON HOURS. THE BEST CHANCE FOR ADDITIONAL ACCUMULATIONS WILL BE INTO THE HIGHER TERRAIN. AS FOR THE SPECIFIC... WEDNESDAY...LATEST TRENDS IN THE MODEL GUIDANCE POINT TOWARD A MORE SIGNIFICANT SURGE OF MOISTURE OFF THE ATLANTIC AS THE MAIN UPPER LOW REMAINS JUST OFF THE JERSEY SHORE. MOISTURE ADVECTION AND HIGHER THETA-E /TROWAL/ BACK INTO PORTIONS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND. SPECIFIC HUMIDITIES REMAIN RATHER HIGH OF 3-4 G/KG SO WHERE IT DOES SNOW...WE COULD SEE ADDITIONAL ACCUMULATIONS OF SNOW. PER THE LATEST NCEP MODEL SUITE AND 00Z ECMWF...THIS SEEMS TO LINE UP FOR OUR NORTHERN HALF OF THE CWFA. ADDITIONAL FINE TUNING WILL TAKE PLACE AS PER CSTAR RESEARCH...THESE UPPER LOWS ARE QUITE PROBLEMATIC WITH PROVIDING SPECIFICS WHERE THE HEAVIER QPF WILL FALL. THURSDAY...AS THE LOW FILLS AND FURTHER REDUCES THE BAROCLINICITY...THE PRECIP INTENSITY AND AMOUNTS WILL DIMINISH. SO ADDITIONAL ACCUMULATIONS SHOULD BE RATHER LIGHT THROUGH THE DAY WITH JUST A COUPLE MORE INCHES OF SNOW...MAINLY INTO THE TERRAIN. THURSDAY NIGHT...WHILE THE UPPER LOW BEGINS TO SLOWLY MIGRATE EASTWARD...ITS INFLUENCES WILL CONTINUE ACROSS THE REGION. THIS WILL RESULT IN CHC-SCT SNOW PROBABILITIES WITH ADDITIONAL LIGHT ACCUMULATIONS THROUGHOUT THE REGION AS TEMPERATURES WILL BE BELOW FREEZING. WE WILL USE A BLENDED APPROACH TO THE MOS TEMPERATURES AS THEY WERE FAIRLY CLOSE IN VALUES. && .LONG TERM /FRIDAY THROUGH TUESDAY/... WE MAY STILL BE DEALING WITH A CUT-OFF UPPER LEVEL LOW FOR FRIDAY INTO SATURDAY...BUT THE SYSTEM WILL HAVE LOST ITS BAROCLINICITY BY THEN RESULTING IN MAINLY SCATTERED SNOW SHOWERS. THE BEST CHANCE FOR ANY LIGHT MEASURABLE SNOWFALL WILL BE OVER THE HIGHER TERRAIN WEST AND EAST OF THE HUDSON RIVER VALLEY...AND ESPECIALLY ACROSS THE SOUTHERN ADIRONDACKS. OUR AREA WILL CONTINUE TO BE UNDER THE INFLUENCE OF THE CYCLONIC FLOW ASSOCIATED WITH THIS SYSTEM...ALTHOUGH DRIER AIR WILL GRADUALLY WORK IN FROM THE WEST...ESPECIALLY ON SATURDAY AS WE SHOULD BE ON THE WESTERN PERIPHERY OF THE CIRCULATION. SO WILL CONTINUE TO MENTION SLIGHT CHANCE TO LOW CHC POPS FOR SNOW SHOWERS FRIDAY AND FRIDAY NIGHT...DECREASING TO SLIGHT CHANCE IN THE VALLEYS FOR SATURDAY. THERE WILL CONTINUE TO BE A SOMEWHAT BETTER CHANCE FOR A PASSING SNOW SHOWER OVER THE HIGHER TERRAIN BOTH FRIDAY AND SATURDAY WITH THE NORTHWEST CYCLONIC FLOW PERSISTING. IT LOOKS LIKE DRIER WEATHER WILL FINALLY PREVAIL FOR LATE SATURDAY INTO SUNDAY...ALTHOUGH THE DEGREE OF CLOUD COVER WILL DEPEND ON HOW QUICKLY THE CUT-OFF LOW MOVES OUT TO SEA. THE ECMWF IS RATHER SLOW WITH THE DEPARTURE OF THE CUT-OFF...LINGERING CYCLONIC FLOW UNTIL SUNDAY...WHILE THE GFS HAS AN UPPER LEVEL RIDGE BUILDING IN BY LATE SATURDAY. AGAIN...THIS WILL HAVE IMPLICATIONS ON CLOUD COVER BUT WE ARE EXPECTING PRECIP-FREE CONDITIONS ON SUNDAY. DESPITE RISING UPPER LEVEL HEIGHTS/TEMPS...SURFACE TEMPS ARE ONLY EXPECTED TO BE SLIGHTLY ABOVE NORMAL DUE TO EXPECTED SHALLOW MIXING THIS TIME OF YEAR. TRANQUIL WEATHER LOOKS TO CONTINUE INTO MONDAY...WITH HIGH PRESSURE AT THE SURFACE AND ALOFT FIRMLY ENTRENCHED OVER THE REGION WITH GOOD AGREEMENT BETWEEN THE ECMWF/GFS. ANOTHER SYSTEM MAY APPROACH FROM THE WEST FOR MON NT AND TUE. WILL ADD SLIGHT CHC POPS...AS THERE IS CONSIDERABLE UNCERTAINTY FOR EARLY NEXT WEEK WHETHER A SOUTHERN STREAM SYSTEM PHASES WITH THE NORTHERN STREAM YET AGAIN...ALBEIT IN A WEAKER STATE THAN THIS WEEK. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... A SIGNIFICANT DEVELOPING COASTAL STORM WITH MULTIPLE PRECIPITATION TYPES WILL IMPACT THE TAF SITES THROUGH THE 24 HOUR TAF PERIOD ALONG WITH IFR/MVFR FLYING CONDITIONS. THIS AFTERNOON...WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN AT THE TAF SITES WILL TRANSITION TO RAIN AT ALL THE TAF SITES BY 20Z...WITH RAIN ALREADY OCCURRING AT KALB...KPOU AND KPSF. RAIN MAY CONTINUE TO BRIEFLY MIX WITH SLEET AT TIMES AT KGFL AND KALB AND HAVE PLACED TEMPO GROUPS FROM 18Z TO 20Z TO ACCOUNT FOR ANY RAIN/SLEET MIX. AFTER 20Z...LOW-LEVEL TEMPERATURES WILL BE ABOVE FREEZING TO SUPPORT ALL RAIN AT THE TAF SITES. FLYING CONDITIONS WILL VARY BETWEEN IFR AND MVFR DEPENDING ON PRECIPITATION INTENSITY THROUGH THE REMAINDER OF THE AFTERNOON. WINDS WILL BE OUT OF THE NORTH AROUND 10 KNOTS WITH OCCASIONAL GUSTS TO 20 KNOTS ESPECIALLY AT KALB AND KPSF. TONIGHT INTO WEDNESDAY...MAINLY IFR CEILINGS ARE EXPECTED THROUGH THE REMAINDER OF THE TAF PERIOD WITH PRIMARILY MVFR VISIBILITIES...ALTHOUGH VISIBILITY COULD EASILY LOWER TO IFR AS WELL DEPENDING ON HOW MUCH PRECIPITATION OCCURS OVERNIGHT. RAIN SHOULD CONTINUE AT THE TAF SITES UNTIL 03Z-08Z...WHEN A TRANSITION TO A RAIN/SNOW MIX IS EXPECTED TO OCCUR AT THE TAF SITES WITH KGFL MIXING WITH SNOW CLOSER TO 03Z AND KALB AND KPSF TRANSITIONING BETWEEN 06Z-08Z. HAVE HELD OFF ANY MENTION OF SNOW AT KPOU UNTIL 12Z AS SURFACE TEMPERATURES LOOK TO REMAIN ABOVE FREEZING FOR MUCH OF THE NIGHT. RAIN/SNOW SHOWERS SHOULD AFFECT THE TAF SITES AFTER 12Z THROUGH THE REMAINDER OF THE TAF PERIOD WITH A TRANSITION TO SNOW AT ALL TAF SITES AFTER 18Z WEDNESDAY. WINDS WILL BE OUT OF THE NORTH AROUND 10 KNOTS WITH OCCASIONAL GUSTS TO 20 KNOTS ESPECIALLY AT KALB AND KPSF. OUTLOOK... WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SN. THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... A FLOOD WATCH REMAINS IN EFFECT FOR LITCHFIELD COUNTY CONNECTICUT...DUTCHESS COUNTY NEW YORK AND EASTERN ULSTER COUNTY NEW YORK...FOR THIS MORNING THROUGH TONIGHT. A COASTAL STORM WILL BRING WIDESPREAD PRECIPITATION TO THE AREA FOR TODAY INTO TONIGHT. FOR NORTHWESTERN AND HIGH TERRAIN AREAS...THIS PRECIPITATION WILL FALL PRIMARY AS SNOW OR A WINTRY MIX. MEANWHILE...ACROSS SOUTHERN AND VALLEY AREAS...PRECIP WILL BEGIN AS A PERIOD OF SNOW OR A WINTRY MIX AND TRANSITION TO RAIN. TOTAL LIQUID EQUIVALENT VALUES WILL BE 0.50 OVER THE WESTERN ADIRONDACKS TO NEARLY 2.00 INCHES OVER WESTERN NEW ENGLAND. WITH MUCH OF THIS FALLING AS RAINFALL OVER LITCHFIELD COUNTY AND THE MID HUDSON VALLEY...THERE WILL BE A LOT OF RUNOFF...ESPECIALLY DURING LATE THIS MORNING THROUGH EARLY THIS EVENING WHEN PRECIP WILL BE HEAVIEST. THIS RAINFALL MAY LEAD TO MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS...ESPECIALLY IN AREAS WHERE THE GROUND IS FROZEN. RISES ON RIVERS AND STREAMS ARE LIKELY...AND MINOR FLOODING CANNOT BE RULED OUT ON THE HOUSATONIC RIVER AND IT/S TRIBUTARIES IN NW CT. IN ADDITION...THE STRONG COASTAL LOW IS ALLOWING FOR SOME TIDAL FLOODING ALONG COASTAL AREAS...AND THIS COULD CAUSE A BACKUP OF WATER ON THE HUDSON RIVER. THIS COULD LEAD TO MINOR FLOODING DURING TIMES OF HIGH TIDE IN THE POUGHKEEPSIE AREA THIS AFTERNOON. SOME ADDITIONAL PRECIPITATION...MAINLY IN THE FORM OF SNOW...IS POSSIBLE FOR WEDNESDAY INTO THURSDAY...BUT AMOUNTS ARE EXPECTED TO BE LIGHT IN AREAS THAT SEE THE HEAVIEST LIQUID PRECIP TODAY. THIS SHOULD ALLOW WATER LEVELS TO RECEDE SLOWLY OVER THE NEXT FEW DAYS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ001-013. NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ032-033- 038>040-042-043-047-048-051-058-063-082. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ041- 049-050-052>054-059>061-083-084. FLOOD WATCH THROUGH LATE TONIGHT FOR NYZ064>066. MA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ001- 025. VT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS/WASULA SHORT TERM...BGM LONG TERM...KL/JPV AVIATION...IRL HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
142 PM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THE MID-MORNING UPDATE...THE FORECAST FROM EARLIER THIS MORNING IS BASICALLY ON TRACK BUT HAVE MADE ADJUSTMENTS TO SOME OF THE HAZARDS. AS OF 900 AM TEMPS ACROSS ALL THE FCST AREA SEEM TO HAVE RISEN ABOVE FREEZING AND ALL REPORTED PRECIP IS RAIN...SO THE WINTER WEATHER ADVISORY FOR PARTS OF NW NJ AND ERN PA HAS BEEN CANCELLED. TEMPS SHOULD CONTINUE TO RISE A COUPLE MORE DEGREES TODAY. THE WINTER STORM WARNING FOR CARBON AND MONROE COUNTIES REMAINS IN EFFECT FOR EXPECTED SNOW LATER TONIGHT AND ON WEDNESDAY. MEANWHILE...RADAR SHOWS THE AREA OF HEAVIEST RAIN NOW WRAPPING WWD ACROSS NRN NJ AND INTO ERN PA. THIS AXIS SHOULD CONTINUE TO SHIFT NWD ALONG WITH THE LOW-LVL STORM CENTER AND BEST EASTERLY INFLOW. THE FLOOD WATCH AREA HAS BEEN ADJUSTED TO REMOVE AREAS FROM PHL SWWD...AND ALSO ADD THE TIER OF COUNTIES OVER FAR NW NJ AND ADJ ERN PA. PREVIOUS DISCUSSION BELOW... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WARNING AND COASTAL FLOOD ADVISORY...NO LONGER IN EFFECT. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CUT THE SE TIER AT 630 AM AND CHANGED TO HEAVIER ICE ACCUMS THE REMAINING ADVISORY AND ALSO THE WINTER STORM WARNING. STILL SLEET IN SUSSEX COUNTY NJ. WE MAY NEED TO ISSUE NEW ADVISORIES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. LATE DAY AND TONIGHT...LOW-END MVFR TO IFR CONDITIONS AT TIMES WITH AREAS OF LIGHT RAIN AND/OR SHOWERS. GUSTY NORTH-NORTHWEST WINDS TO BETWEEN 20 TO 30 KT ARE EXPECTED THROUGH LATE-DAY, BEFORE WINDS BACK A LITTLE MORE TO THE NORTHWEST AND GUSTS DECREASE SOMEWHAT TO MORE IN THE 18 TO 24 KNOT RANGE FOR LATE EVENING AND OVERNIGHT. WITH THE STORM SYSTEM ONLY SLOWLY MOVING AWAY OVERNIGHT, MORE WRAP-AROUND MOISTURE WILL YIELD SOME BANDS OF RAIN SHIFTING SOUTHEASTWARD ACROSS THE REGION, WITH RAIN CHANGING TO WET SNOW, ESPECIALLY AT KRDG AND KABE DURING THE EARLY MORNING HOURS WEDNESDAY. WE ALSO HAVE MEDIUM CONFIDENCE ON A RAIN/SNOW MIX AND A WINDOW OF A FEW HOURS OF POSSIBLE WET SNOW TOWARD THE DELAWARE VALLEY TAF SITES, INCLUDING KPHL, INTO WEDNESDAY MORNING. WEDNESDAY...CONTINUED RESTRICTIONS IN THE MVFR TO POSSIBLY IFR RANGE WITH SOME BANDS OF RAIN AND SNOW SHOWERS. GUSTY NORTHWEST WINDS WILL CONTINUE, WITH GUSTS INCREASING DURING THE DAYTIME, MORE IN THE 23 TO 30 KNOT RANGE. OUTLOOK... WEDNESDAY NIGHT THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING HAS BEEN CONVERTED TO SMALL CRAFT ADVISORY FOR COASTAL WATERS SOUTH OF GREAT EGG INLET AND FOR LOWER DELAWARE BAY. THE GALE WARNING CONTINUES NORTH OF GREAT EGG IN TIGHTER PRES GRADIENT AHEAD OF DEEPENING SFC LOW AND GALE FORCE NE WINDS. THE SCA WAS EXTENDED OVERNIGHT AND WILL LIKELY NEED FURTHER EXTENSION INTO WED FOR ALL WATERS...AS THE SFC LOW IS FCST TO STALL INVOF LONG ISLAND. WINDS WILL BECOME OFFSHORE OR MORE OFFSHORE RESULTING IN SMWHT LOWER SEAS WITH THE MORE LIMITED FETCH. PREVIOUS DISCUSSION BELOW... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... THE FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR FROM PHILLY NORTH. THE SOUTHERN PORTION OF THE WATCH HAS BEEN CANCELLED WITH THE BULK OF THE MODERATE TO HEAVY RAIN PUSHING NORTH. FOUR COUNTIES HAVE BEEN ADDED OF THE NORTHWEST PERIPHERY, LEHIGH NORTHEAST THROUGH SUSSEX AS THE PRECIPITATION HAS BECOME LIQUID. THE HEAVIER RAINS WILL CONTINUE INTO THE MID TO LATE AFTERNOON HOURS BEFORE ENDING. RUNOFF WILL CONTINUE THROUGH THE OVERNIGHT, LONGER IN SOME SPOTS. ANTECEDENT CONDITIONS ARE WET DUE TO THE RAINS THE REGION SAW THIS PAST SATURDAY. THIS IS ALLOWING FOR A MORE EFFICIENT RUNOFF. WHERE IT RAINS THE HEAVIEST, TOTAL RAINFALL ACCUMULATIONS WILL BE IN THE 2 TO 3 INCH RANGE. THERE COULD BE SOME TOTALS OVER 3 INCHES. SMALLER CREEKS AND STREAMS WILL BE THE FIRST BODIES OF WATER TO RESPOND. THEY ALREADY HAVE. THOSE AREAS WHICH DRAIN INTO TIDAL WATERS COULD SEE INCREASED FLOODING (IN THE MINOR CATEGORY) DUE TO HIGHER THAN NORMAL TIDES. ON THE LARGER BODIES OF WATER THAT ARE SUPPORTED BY THE MARFC, THERE ARE ABOUT A DOZEN FORECAST POINTS THAT EXCEED CAUTION/ACTION STAGE, A FEW OF THEM LASTING THROUGH THE NEXT FEW DAYS. THE MAJORITY OF THESE POINT ARE IN NJ. AS FOR GAUGES HITTING FLOOD STAGE, WE WILL KEEP AN EYE ON BLACKWELLS MILLS AND PEMBERTON. IF RUNOFF AND RISES CONTINUE AS EXPECTED INTO THIS AFTERNOON, FLOOD WARNINGS WILL BE ISSUED LATER TODAY. PEMBERTON COULD HIT FLOOD STAGE AS EARLY AS THIS EVENING AND BLACKWELLS MILLS COULD HIT FLOOD STAGE OVERNIGHT TONIGHT. && .TIDES/COASTAL FLOODING... A WIND SHIFT TO THE NORTH IS EASING AND REVERSING THE POSITIVE TIDAL ANOMALIES ALONG THE COAST AND ASSOCIATED BACK BAYS, AND THE DELAWARE BAY TOO. WATER LEVELS ALONG THE COAST PEAKED AT OR JUST BELOW THE MODERATE THRESHOLD AT HIGH TIDE THIS MORNING/EARLY AFTERNOON, AND WITH DECREASING ANOMALIES AND LOWER ASTRONOMICAL TIDES DURING THE NEXT HIGH TIDE CYCLE, NO SIGNIFICANT TIDAL PROBLEMS ARE EXPECTED TONIGHT. EVEN ON THE UPPER DELAWARE BAY, WATER LEVELS PEAKED BELOW EVEN THE MINOR FLOOD THRESHOLD AT REEDY POINT EARLY THIS AFTERNOON. WITH A GRADUAL WIND SHIFT TO THE NORTHWEST EXPECTED THROUGH THE OVERNIGHT HOURS AS THE COASTAL LOW CONTINUES ITS SLOW NORTHWARD MOVEMENT, ANY ADDITIONAL FLOODING IS EXPECTED TO BE MINOR IN NATURE. THE COASTAL FLOOD WARNINGS AND ADVISORIES ARE THEREFORE NO LONGER IN EFFECT. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH UNTIL 1 AM EST WEDNESDAY FOR PAZ061-062-103>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. NJ...FLOOD WATCH UNTIL 1 AM EST WEDNESDAY FOR NJZ001-007>010- 012>015-019-020-025>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. DE...NONE. MD...NONE. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>452. SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR ANZ430-431- 453>455. && $$ SYNOPSIS...O`HARA NEAR TERM...AMC/DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/KLINE/O`HARA MARINE...AMC/DRAG/O`HARA HYDROLOGY... TIDES/COASTAL FLOODING... CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
133 PM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THE MID-MORNING UPDATE...THE FORECAST FROM EARLIER THIS MORNING IS BASICALLY ON TRACK BUT HAVE MADE ADJUSTMENTS TO SOME OF THE HAZARDS. AS OF 900 AM TEMPS ACROSS ALL THE FCST AREA SEEM TO HAVE RISEN ABOVE FREEZING AND ALL REPORTED PRECIP IS RAIN...SO THE WINTER WEATHER ADVISORY FOR PARTS OF NW NJ AND ERN PA HAS BEEN CANCELLED. TEMPS SHOULD CONTINUE TO RISE A COUPLE MORE DEGREES TODAY. THE WINTER STORM WARNING FOR CARBON AND MONROE COUNTIES REMAINS IN EFFECT FOR EXPECTED SNOW LATER TONIGHT AND ON WEDNESDAY. MEANWHILE...RADAR SHOWS THE AREA OF HEAVIEST RAIN NOW WRAPPING WWD ACROSS NRN NJ AND INTO ERN PA. THIS AXIS SHOULD CONTINUE TO SHIFT NWD ALONG WITH THE LOW-LVL STORM CENTER AND BEST EASTERLY INFLOW. THE FLOOD WATCH AREA HAS BEEN ADJUSTED TO REMOVE AREAS FROM PHL SWWD...AND ALSO ADD THE TIER OF COUNTIES OVER FAR NW NJ AND ADJ ERN PA. PREVIOUS DISCUSSION BELOW... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WARNING: HAZARD ON TARGET WITH MDT FLOODING ASSURED AND IT MAY BE A STRONG MODERATE DOWN IN THE CAPE MAY-LEWES AREA. SURGE OF 2 TO POSSIBLY 3 FEET AT HIGH TIDE THIS MORNING. SANDY HOOK LINKED COUNTIES I THINK MAY ESCAPE MDT FLOODING BUT NO CHANGE TO THE WARNING. DEPARTURES AT SANDY HOOK ABOUT A FOOT LESS THAN FURTHER SOUTH WHERE STRONGER INFLOW AND LOWER PRESSURE. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CUT THE SE TIER AT 630 AM AND CHANGED TO HEAVIER ICE ACCUMS THE REMAINING ADVISORY AND ALSO THE WINTER STORM WARNING. STILL SLEET IN SUSSEX COUNTY NJ. WE MAY NEED TO ISSUE NEW ADVISORIES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. LATE DAY AND TONIGHT...LOW-END MVFR TO IFR CONDITIONS AT TIMES WITH AREAS OF LIGHT RAIN AND/OR SHOWERS. GUSTY NORTH-NORTHWEST WINDS TO BETWEEN 20 TO 30 KT ARE EXPECTED THROUGH LATE-DAY, BEFORE WINDS BACK A LITTLE MORE TO THE NORTHWEST AND GUSTS DECREASE SOMEWHAT TO MORE IN THE 18 TO 24 KNOT RANGE FOR LATE EVENING AND OVERNIGHT. WITH THE STORM SYSTEM ONLY SLOWLY MOVING AWAY OVERNIGHT, MORE WRAP-AROUND MOISTURE WILL YIELD SOME BANDS OF RAIN SHIFTING SOUTHEASTWARD ACROSS THE REGION, WITH RAIN CHANGING TO WET SNOW, ESPECIALLY AT KRDG AND KABE DURING THE EARLY MORNING HOURS WEDNESDAY. WE ALSO HAVE MEDIUM CONFIDENCE ON A RAIN/SNOW MIX AND A WINDOW OF A FEW HOURS OF POSSIBLE WET SNOW TOWARD THE DELAWARE VALLEY TAF SITES, INCLUDING KPHL, INTO WEDNESDAY MORNING. WEDNESDAY...CONTINUED RESTRICTIONS IN THE MVFR TO POSSIBLY IFR RANGE WITH SOME BANDS OF RAIN AND SNOW SHOWERS. GUSTY NORTHWEST WINDS WILL CONTINUE, WITH GUSTS INCREASING DURING THE DAYTIME, MORE IN THE 23 TO 30 KNOT RANGE. OUTLOOK... WEDNESDAY NIGHT THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING HAS BEEN CONVERTED TO SMALL CRAFT ADVISORY FOR COASTAL WATERS SOUTH OF GREAT EGG INLET AND FOR LOWER DELAWARE BAY. THE GALE WARNING CONTINUES NORTH OF GREAT EGG IN TIGHTER PRES GRADIENT AHEAD OF DEEPENING SFC LOW AND GALE FORCE NE WINDS. THE SCA WAS EXTENDED OVERNIGHT AND WILL LIKELY NEED FURTHER EXTENSION INTO WED FOR ALL WATERS...AS THE SFC LOW IS FCST TO STALL INVOF LONG ISLAND. WINDS WILL BECOME OFFSHORE OR MORE OFFSHORE RESULTING IN SMWHT LOWER SEAS WITH THE MORE LIMITED FETCH. PREVIOUS DISCUSSION BELOW... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... THE FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR FROM PHILLY NORTH. THE SOUTHERN PORTION OF THE WATCH HAS BEEN CANCELLED WITH THE BULK OF THE MODERATE TO HEAVY RAIN PUSHING NORTH. FOUR COUNTIES HAVE BEEN ADDED OF THE NORTHWEST PERIPHERY, LEHIGH NORTHEAST THROUGH SUSSEX AS THE PRECIPITATION HAS BECOME LIQUID. THE HEAVIER RAINS WILL CONTINUE INTO THE MID TO LATE AFTERNOON HOURS BEFORE ENDING. RUNOFF WILL CONTINUE THROUGH THE OVERNIGHT, LONGER IN SOME SPOTS. ANTECEDENT CONDITIONS ARE WET DUE TO THE RAINS THE REGION SAW THIS PAST SATURDAY. THIS IS ALLOWING FOR A MORE EFFICIENT RUNOFF. WHERE IT RAINS THE HEAVIEST, TOTAL RAINFALL ACCUMULATIONS WILL BE IN THE 2 TO 3 INCH RANGE. THERE COULD BE SOME TOTALS OVER 3 INCHES. SMALLER CREEKS AND STREAMS WILL BE THE FIRST BODIES OF WATER TO RESPOND. THEY ALREADY HAVE. THOSE AREAS WHICH DRAIN INTO TIDAL WATERS COULD SEE INCREASED FLOODING (IN THE MINOR CATEGORY) DUE TO HIGHER THAN NORMAL TIDES. ON THE LARGER BODIES OF WATER THAT ARE SUPPORTED BY THE MARFC, THERE ARE ABOUT A DOZEN FORECAST POINTS THAT EXCEED CAUTION/ACTION STAGE, A FEW OF THEM LASTING THROUGH THE NEXT FEW DAYS. THE MAJORITY OF THESE POINT ARE IN NJ. AS FOR GAUGES HITTING FLOOD STAGE, WE WILL KEEP AN EYE ON BLACKWELLS MILLS AND PEMBERTON. IF RUNOFF AND RISES CONTINUE AS EXPECTED INTO THIS AFTERNOON, FLOOD WARNINGS WILL BE ISSUED LATER TODAY. PEMBERTON COULD HIT FLOOD STAGE AS EARLY AS THIS EVENING AND BLACKWELLS MILLS COULD HIT FLOOD STAGE OVERNIGHT TONIGHT. && .TIDES/COASTAL FLOODING... COASTAL FLOOD WARNING CONTINUES AS NOTED IN THE NEAR TERM SECTION. WATER BUILDUP HAS OCCURRED IN ALL OUR TIDAL WATERS DURING THE PAST SEVERAL TIDE CYCLES, INCLUDING THE DELAWARE AND CHESAPEAKE BAYS AND THE DELAWARE RIVER. ANOMALIES THIS MORNING ARE RUNNING BETWEEN 2 AND 2.5 FEET ABOVE NORMAL NORTH OF ATLANTIC CITY, AND 2.5 TO 3 FEET ABOVE NORMAL SOUTH OF ATLANTIC CITY. IN THE DELAWARE BAY, ANOMALIES ARE AROUND 2.5 FEET ABOVE NORMAL, AND IN THE CHESAPEAKE BAY 1 FOOT ABOVE NORMAL. A STRONG ONSHORE FLOW SHOULD MAINTAIN THESE ANOMALIES THROUGH THE HIGH TIDE CYCLE THIS MORNING AND EARLY AFTERNOON. THEN, AS THE COASTAL LOW CONTINUES TO MOVE SLOWLY NORTH, WINDS WILL GRADUALLY SHIFT TO THE NORTH, THEN NORTHWEST, WHICH SHOULD EAT AWAY AT THESE ANOMALIES, PARTICULARLY SOUTH OF ATLANTIC CITY. LOWER ANOMALIES COMBINED WITH A SMALLER ASTRONOMICAL CONTRIBUTION (0.5 TO 1.0 FOOT LOWER) SHOULD KEEP ANY ADDITIONAL TIDAL FLOODING DURING THE NEXT HIGH TIDE CYCLE TONIGHT IN THE MINOR RANGE FROM ATLANTIC CITY SOUTH. SO...MODERATE FLOODING EXPECTED ALONG THE COAST AND ASSOCIATED BACKBAYS WITH THIS MORNINGS HIGH TIDE, MODERATE FLOODING EXPECTED ALONG THE SHORES OF THE LOWER DELAWARE BAY, AND MINOR TO LOW END MODERATE FLOODING EXPECTED ON THE UPPER DELAWARE BAY. MINOR TIDAL FLOODING IS A POSSIBILITY ON THE TIDAL DELAWARE (NORTH OF REEDY POINT, INCLUDING PHILADELPHIA), AND AN ADVISORY MAY BE NEEDED. ELEVATED WATER LEVELS ARE OCCURRING IN THE NORTHERN PORTIONS OF THE CHESAPEAKE BAY, BUT NO FLOODING IS EXPECTED. AS ALWAYS, ROUGH SURF AND HEAVY RAIN AT THE TIME OF HIGH TIDE WILL EXACERBATE THE FLOODING ISSUE. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH UNTIL 1 AM EST WEDNESDAY FOR PAZ061-062-103>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. NJ...FLOOD WATCH UNTIL 1 AM EST WEDNESDAY FOR NJZ001-007>010- 012>015-019-020-025>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. DE...NONE. MD...NONE. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>452. SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR ANZ430-431- 453>455. && $$ SYNOPSIS...O`HARA NEAR TERM...AMC/DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/KLINE/O`HARA MARINE...AMC/DRAG/O`HARA HYDROLOGY...KRUZDLO TIDES/COASTAL FLOODING...MIKETTA CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1255 PM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE MIDDLE ATLANTIC COAST TODAY WHILE MOVING NORTHWARD THROUGH WEDNESDAY. THE STORM WILL SLOWLY WEAKENS AND MEANDER NORTHEASTWARD FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE IN THE OHIO VALLEY WILL BECOME THE PRIMARY INFLUENCE FOR OUR WEATHER THIS COMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THE MID-MORNING UPDATE...THE FORECAST FROM EARLIER THIS MORNING IS BASICALLY ON TRACK BUT HAVE MADE ADJUSTMENTS TO SOME OF THE HAZARDS. AS OF 900 AM TEMPS ACROSS ALL THE FCST AREA SEEM TO HAVE RISEN ABOVE FREEZING AND ALL REPORTED PRECIP IS RAIN...SO THE WINTER WEATHER ADVISORY FOR PARTS OF NW NJ AND ERN PA HAS BEEN CANCELLED. TEMPS SHOULD CONTINUE TO RISE A COUPLE MORE DEGREES TODAY. THE WINTER STORM WARNING FOR CARBON AND MONROE COUNTIES REMAINS IN EFFECT FOR EXPECTED SNOW LATER TONIGHT AND ON WEDNESDAY. MEANWHILE...RADAR SHOWS THE AREA OF HEAVIEST RAIN NOW WRAPPING WWD ACROSS NRN NJ AND INTO ERN PA. THIS AXIS SHOULD CONTINUE TO SHIFT NWD ALONG WITH THE LOW-LVL STORM CENTER AND BEST EASTERLY INFLOW. THE FLOOD WATCH AREA HAS BEEN ADJUSTED TO REMOVE AREAS FROM PHL SWWD...AND ALSO ADD THE TIER OF COUNTIES OVER FAR NW NJ AND ADJ ERN PA. PREVIOUS DISCUSSION BELOW... MULTI-FACETED HAZARD HEADLINE EVENT IN PROGRESS. FOCUSING ON IMPACTS AND BRIEFLY DISCUSSING SCIENCE WHERE IT MAY BE HELPFUL. FLOOD WATCH: WE MAY NEED TO CANCEL THE SW PORTION OF THE FLOOD WATCH IN OUR MID OR LATE MORNING UPDATE. IT LOOKS TO ME PER THE RECENT GFS AND HRRR AS WELL AS RADAR THAT THE GREATER RISK FOR REPEAT EPISODES OF HEAVY RAIN TODAY WILL BE COASTAL AND NORTHERN NJ AND MAYBE NEAR OR JUST NORTH OF KRDG. COASTAL FLOOD WARNING: HAZARD ON TARGET WITH MDT FLOODING ASSURED AND IT MAY BE A STRONG MODERATE DOWN IN THE CAPE MAY-LEWES AREA. SURGE OF 2 TO POSSIBLY 3 FEET AT HIGH TIDE THIS MORNING. SANDY HOOK LINKED COUNTIES I THINK MAY ESCAPE MDT FLOODING BUT NO CHANGE TO THE WARNING. DEPARTURES AT SANDY HOOK ABOUT A FOOT LESS THAN FURTHER SOUTH WHERE STRONGER INFLOW AND LOWER PRESSURE. WIND ADVY: BEST POTENTIAL WHERE DESCRIBED ...MAY NEED TO ADD ATLANTIC COUNTY AT THE LAST MINUTE. FEW GUSTS OF 45 KT EXPECTED MID OR LATE MORNING. AT 5 AM ..MANY REPORTS AROUND 40 KT DE COAST TO MD ATLANTIC COAST BORDERING DE. WINTER WEATHER ADVISORIES: CUT THE SE TIER AT 630 AM AND CHANGED TO HEAVIER ICE ACCUMS THE REMAINING ADVISORY AND ALSO THE WINTER STORM WARNING. STILL SLEET IN SUSSEX COUNTY NJ. WE MAY NEED TO ISSUE NEW ADVISORIES FOR EARLY WEDNESDAY AS BACKSIDE BANDING DEVELOPS ON BACK BENT MID LEVEL FRONT AND STILL WAA OVER NYS AND NEW ENGLAND DRIVING LIFT IN THE FAVORABLE LEFT SIDE OF THE 700 LOW. THIS NEEDS TO BE WATCHED FOR POTENTIAL SEVERAL HOURS OF MODERATE TO HEAVY WET SNOW EARLY WEDNESDAY. GUSTY WINDS AS WELL MAY ADD TO THE PROBLEMS AS TEMPS FALL TO NEAR FREEZING. WINTER STORM WARNING EXTENDED TO 18Z WED TO CAPTURE BACKSIDE SNOW. THIS IS THE MOST UNCERTAIN PART OF THE FORECAST. NEARLY ISOTHERMAL VERTICAL THERMAL PROFILE WESTERN PORTION OF CARBON/MONROE COUNTY WITH EXPECTED MXD FREEZING/FROZEN PCPN AT THE START CHANGING TO A PERIOD OF HEAVY SNOW THIS MORNING. THEN THE LIFT WEAKENS LATE MORNING AND IT MAY TURN TO RAIN OR FREEZING THERE THIS AFTERNOON. TONIGHT THE TEMPERATURES ALOFT COOL AND THEN WE LOOK FOR POTENTIAL BANDING AND IF THIS OCCURS...ADDITIONAL MDT OR HEAVY SNOWFALL WOULD OCCUR. DIFFICULT FORECAST AND WE`RE TRYING TO SLICE THIS VERY CLOSE TO THE MARK. A WORRISOME FORECAST ON PTYPE. AT 5AM..SE MONROE COUNTY HEAVY SLEET AND FREEZING RAIN. WE ARE GETTING REPORTS OF FREEZING RAIN IN ALLAMUCHY (.1 GLAZE) AND OXFORD NJ HAS SOME SLEET AND FREEZING RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PLEASE SEE NEAR TERM FOR SOME INFO AND CONTINUE THE THEME WRITTEN IN THE AFD FROM YESTERDAY AFTERNOON. EXPECT A GOOD CHUNK OF THE SNOWFALL TO OCCUR ON THE BACKSIDE OF THIS SYSTEM LATER TONIGHT AS STRONGER OMEGA AND FGEN COME TOGETHER. MOSTLY BASED ON WHERE WE THINK THE BACKSIDE DEFORMATION ZONE WILL SETUP...IN PENNSYLVANIA. SNOWFALL RATES COULD BE PRETTY HEFTY ACROSS OUR EASTERN PA ZONES WEST OF PHILADELPHIA DOYLESTOWN AND ALLENTOWN OVERNIGHT (EXCT SNOW GROWTH AND I THINK POTENTIAL FOR 4+ IF THE MODELED SCENARIO VERIFIES) AS WE SEE THE TRANSITION FROM RAIN BACK TO SNOW. STILL THINK A SWATH OF 8-10 INCHES IS VERY POSSIBLE WITH HIGHER AMOUNTS IN THE HIGHER ELEVATIONS WESTERN MONROE AND WESTERN CARBON COUNTIES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... WEDNESDAY AND WEDNESDAY NIGHT...MUCH OF THE AREA IS STILL UNDER THE INFLUENCE OF THE STRONG LOW WHICH WILL MEANDER NORTH/EAST OF THE REGION. BANDS OF SNOW AND RAIN WILL BE ACROSS THE AREA WITH ACCUMS POSSIBLE MOSTLY N/W. GFS MODEL OVERNIGHT PAINTS SIGNIFICANT SNOWS LEHIGH VALLEY NORTH AND WEST...BUT THIS WAS TONED DOWN SOMEWHAT WITH AN EC SOLUTION MORE LIKELY. WE COULD ADD 1 TO 2 INCHES TO SNOW TOTALS WED N/W. THURSDAY AND THURSDAY NIGHT...COLD WITH GUSTY WINDS AND A FEW SNOW SHOWERS AS THE LOW STARTS TO RELAX ITS GRIP OVER THE AREA. CHC POPS N/W AND SLGT CHC POPS S/E...THESE POPS DECREASE THU NIGHT. FRI THRU MONDAY...HIGH PRESSURE BUILDS IN AND SEVERAL DRY DAYS EXPECTED. MODERATING TEMPS...WITH READINGS 4 OR 5 DEGREES BELOW NORMAL SAT THEN RISING TO NEAR NORMAL BY MONDAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...IFR TO POSSIBLY LOW-END MVFR IN RAIN OR DRIZZLE, AS MOST OF THE STEADIER MODERATE RAIN WILL CONTINUE LIFTING NORTH OF THE TAF SITES THROUGH THE REST OF THIS MORNING. GUSTY NORTH WINDS TO BETWEEN 20 TO 30 KT ARE EXPECTED, EXCEPT AROUND 35 KT AT TIMES IN VICINITY OF KACY. CONDITIONS SHOULD IMPROVE THIS AFTERNOON AS THE STEADIER RAIN LIFTS NORTH AND WINDS TURN SLIGHTLY MORE NORTH NORTHWEST. GUSTS DIMINISH LATE TODAY. TONIGHT...MVFR CIGS WITH BANDS OF RAIN SHIFTING SOUTHEASTWARD AND RAIN CHANGING TO WET SNOW AT KRDG AND KABE. NORTH TO NORTHWEST WINDS GUST 20 TO 30 KT. OUTLOOK... WEDNESDAY THROUGH THURSDAY: SOME RESTRICTIONS TO MVFR OR IFR IN BANDS OF RAIN AND SNOW SHOWERS. NORTHWEST WIND GUSTS 20-30 KNOTS AT TIMES. FRIDAY: VFR...A FEW WIDELY SCT SHOWERS FAR N/W EARLY. SATURDAY: VFR. && .MARINE... GALE WARNING HAS BEEN CONVERTED TO SMALL CRAFT ADVISORY FOR COASTAL WATERS SOUTH OF GREAT EGG INLET AND FOR LOWER DELAWARE BAY. THE GALE WARNING CONTINUES NORTH OF GREAT EGG IN TIGHTER PRES GRADIENT AHEAD OF DEEPENING SFC LOW AND GALE FORCE NE WINDS. THE SCA WAS EXTENDED OVERNIGHT AND WILL LIKELY NEED FURTHER EXTENSION INTO WED FOR ALL WATERS...AS THE SFC LOW IS FCST TO STALL INVOF LONG ISLAND. WINDS WILL BECOME OFFSHORE OR MORE OFFSHORE RESULTING IN SMWHT LOWER SEAS WITH THE MORE LIMITED FETCH. PREVIOUS DISCUSSION BELOW... GALE WARNING CONTINUES ON OUR WATERS WITH NO CHANGES. THERE COULD BE SOME STORM FORCE GUSTS ACROSS THE WATERS THIS MORNING-MIDDAY BUT CONFIDENCE NOT HIGH ENOUGH TO ISSUE A STORM WARNING NOR DO WE THINK THEY WILL BE PERSISTENT. SEAS WILL CONTINUE TO BUILD UPWARDS OF 15 FEET ACROSS A MAJORITY OF OUR WATERS....POSSIBLY BRIEFLY 17 OR 18 FT AT 44009. WINDS SUBSIDE LATE TODAY OR TONIGHT WITH THE PRESSURE GRADIENT WEAKENING ON THE SOUTHWEST SIDE OF THE LOW PARKED EAST BELMAR. SCA CONDITIONS. OUTLOOK... WEDNESDAY AND WEDNESDAY NIGHT: HIGH END SCA CONDITIONS WITH GALE GUSTS POSSIBLE. SEAS MOSTLY 5 TO 9 FEET. THURSDAY AND THURSDAY NIGHT: SCA SEAS AND GUSTS CONTINUE WITH LOW PRESSURE STILL TO NORTHEAST. FRIDAY AND SATURDAY: NO HEADLINES EXPECTED ATTM. && .HYDROLOGY... THE FLOOD WATCH CONTINUES FOR THE I-95 CORRIDOR FROM PHILLY NORTH. THE SOUTHERN PORTION OF THE WATCH HAS BEEN CANCELLED WITH THE BULK OF THE MODERATE TO HEAVY RAIN PUSHING NORTH. FOUR COUNTIES HAVE BEEN ADDED OF THE NORTHWEST PERIPHERY, LEHIGH NORTHEAST THROUGH SUSSEX AS THE PRECIPITATION HAS BECOME LIQUID. THE HEAVIER RAINS WILL CONTINUE INTO THE MID TO LATE AFTERNOON HOURS BEFORE ENDING. RUNOFF WILL CONTINUE THROUGH THE OVERNIGHT, LONGER IN SOME SPOTS. ANTECEDENT CONDITIONS ARE WET DUE TO THE RAINS THE REGION SAW THIS PAST SATURDAY. THIS IS ALLOWING FOR A MORE EFFICIENT RUNOFF. WHERE IT RAINS THE HEAVIEST, TOTAL RAINFALL ACCUMULATIONS WILL BE IN THE 2 TO 3 INCH RANGE. THERE COULD BE SOME TOTALS OVER 3 INCHES. SMALLER CREEKS AND STREAMS WILL BE THE FIRST BODIES OF WATER TO RESPOND. THEY ALREADY HAVE. THOSE AREAS WHICH DRAIN INTO TIDAL WATERS COULD SEE INCREASED FLOODING (IN THE MINOR CATEGORY) DUE TO HIGHER THAN NORMAL TIDES. ON THE LARGER BODIES OF WATER THAT ARE SUPPORTED BY THE MARFC, THERE ARE ABOUT A DOZEN FORECAST POINTS THAT EXCEED CAUTION/ACTION STAGE, A FEW OF THEM LASTING THROUGH THE NEXT FEW DAYS. THE MAJORITY OF THESE POINT ARE IN NJ. AS FOR GAUGES HITTING FLOOD STAGE, WE WILL KEEP AN EYE ON BLACKWELLS MILLS AND PEMBERTON. IF RUNOFF AND RISES CONTINUE AS EXPECTED INTO THIS AFTERNOON, FLOOD WARNINGS WILL BE ISSUED LATER TODAY. PEMBERTON COULD HIT FLOOD STAGE AS EARLY AS THIS EVENING AND BLACKWELLS MILLS COULD HIT FLOOD STAGE OVERNIGHT TONIGHT. && .TIDES/COASTAL FLOODING... COASTAL FLOOD WARNING CONTINUES AS NOTED IN THE NEAR TERM SECTION. WATER BUILDUP HAS OCCURRED IN ALL OUR TIDAL WATERS DURING THE PAST SEVERAL TIDE CYCLES, INCLUDING THE DELAWARE AND CHESAPEAKE BAYS AND THE DELAWARE RIVER. ANOMALIES THIS MORNING ARE RUNNING BETWEEN 2 AND 2.5 FEET ABOVE NORMAL NORTH OF ATLANTIC CITY, AND 2.5 TO 3 FEET ABOVE NORMAL SOUTH OF ATLANTIC CITY. IN THE DELAWARE BAY, ANOMALIES ARE AROUND 2.5 FEET ABOVE NORMAL, AND IN THE CHESAPEAKE BAY 1 FOOT ABOVE NORMAL. A STRONG ONSHORE FLOW SHOULD MAINTAIN THESE ANOMALIES THROUGH THE HIGH TIDE CYCLE THIS MORNING AND EARLY AFTERNOON. THEN, AS THE COASTAL LOW CONTINUES TO MOVE SLOWLY NORTH, WINDS WILL GRADUALLY SHIFT TO THE NORTH, THEN NORTHWEST, WHICH SHOULD EAT AWAY AT THESE ANOMALIES, PARTICULARLY SOUTH OF ATLANTIC CITY. LOWER ANOMALIES COMBINED WITH A SMALLER ASTRONOMICAL CONTRIBUTION (0.5 TO 1.0 FOOT LOWER) SHOULD KEEP ANY ADDITIONAL TIDAL FLOODING DURING THE NEXT HIGH TIDE CYCLE TONIGHT IN THE MINOR RANGE FROM ATLANTIC CITY SOUTH. SO...MODERATE FLOODING EXPECTED ALONG THE COAST AND ASSOCIATED BACKBAYS WITH THIS MORNINGS HIGH TIDE, MODERATE FLOODING EXPECTED ALONG THE SHORES OF THE LOWER DELAWARE BAY, AND MINOR TO LOW END MODERATE FLOODING EXPECTED ON THE UPPER DELAWARE BAY. MINOR TIDAL FLOODING IS A POSSIBILITY ON THE TIDAL DELAWARE (NORTH OF REEDY POINT, INCLUDING PHILADELPHIA), AND AN ADVISORY MAY BE NEEDED. ELEVATED WATER LEVELS ARE OCCURRING IN THE NORTHERN PORTIONS OF THE CHESAPEAKE BAY, BUT NO FLOODING IS EXPECTED. AS ALWAYS, ROUGH SURF AND HEAVY RAIN AT THE TIME OF HIGH TIDE WILL EXACERBATE THE FLOODING ISSUE. && .CLIMATE... RECORD RAINFALLS FOR TUESDAY IN OUR HISTORICAL DATABASE. ACY 2.51 2009 PHL 2.13 2009 ILG 2.28 2009 ABE 1.51 1973 TTN 2.25 1978 GED 1.93 2009 RDG 1.16 2009 MPO 1.82 1974 RECORD SNOWFALL FOR WEDNESDAY (LONG SHOT BUT JUST IN CASE) PHL 4.3 1904 ILG 2.9 2013 ABE 2.7 2013 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ061-062-103>106. WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ054-055. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ001-007>010-012>015- 019-020-025>027. COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ012>014-020>027. WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NJZ012>014-020- 022-025>027. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR NJZ016. DE...COASTAL FLOOD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ002>004. COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR DEZ001. MD...NONE. MARINE...GALE WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ450>452. SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR ANZ430-431- 453>455. && $$ SYNOPSIS...O`HARA NEAR TERM...AMC/DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/KLINE/O`HARA MARINE...AMC/DRAG/O`HARA HYDROLOGY... TIDES/COASTAL FLOODING... CLIMATE...
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1143 AM CST TUE DEC 9 2014 .SHORT TERM /TODAY/... ISSUED AT 301 AM CST TUE DEC 9 2014 CLOUD COVER AND TEMPS WERE THE FOCUS AS THE SURFACE HIGH SLOWLY BUILDS INTO THE STATE THROUGHOUT THE DAY TODAY. CAA CONTINUES THIS MORNING AND FINALLY DIMINISHES BY THE EARLY AFTERNOON. LOW LEVEL MOISTURE LOOKS TO POTENTIALLY REMAIN TRAPPED UNDER THE INVERSION SETTING UP AROUND 925M THROUGH THE DAY. THIS WOULD SUGGEST LOW STRATUS DECK TO LINGER INTO THE AFTERNOON AND INCREASED SKY COVER DURING THIS TIME TO REFLECT THIS TREND. THE 09.06Z HRRR AND 09.03Z HOPWRF HINTING ON CLOUD COVER LASTING THROUGH THE AFTERNOON HOURS TODAY AS WELL. TEMPS SHOULD STRUGGLE TO INCREASE MUCH TODAY WITH THE STRATUS AND CAA PERSISTING FOR MUCH OF THE DAY. LOWERED MAX TEMPS ACROSS THE NORTH AND WEST A DEGREE BUT LEFT THE REMAINDER OF THE FORECAST WITH PREVIOUS FORECAST AS IT LOOKED ON TRACK. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 301 AM CST TUE DEC 9 2014 OVERALL...THE MID TO LATE WEEK PATTERN WILL FEATURE A PERIOD OF INCREASED WARMING AND MOISTURE. SUBJECTIVE H850 ANALYSIS TONIGHT SHOWS UPPER LEVEL LOW AND COLD AIR ADVECTION OVER THE REGION...WITH THE GREAT LAKES WAVE SUPPRESSING MOISTURE TO THE FAR SOUTHERN STATES. HIGH PRESSURE ALOFT OVER THE SOUTHERN PLAINS IS ALREADY SUPPORTING RETURN FLOW OVER THE RED RIVER VALLEY INTO NEW MEXICO. MODELS SHOW THAT THIS PLUME WILL GRADUALLY MOVE NORTHWEST THEN NORTHEAST INTO THE CENTRAL PLAINS BY MID TO LATE WEEK...AND THROUGH THE WEEKEND. THOUGH THE PATTERN REMAINS FAIRLY QUIET INTO THE EARLY WEEKEND...THE RETURN OF MOISTURE AND LOW STRATUS ALONG WITH DRIZZLE OR LIGHT RAIN POTENTIAL WILL BE THE MAIN CHALLENGES IN THE NEXT 5 DAYS. FOR TONIGHT...A WEAK WAVE CURRENTLY OVER MONTANA WILL DROP SOUTHEAST INTO THE NORTHWEST FLOW AND BRING WITH IT ANOTHER AREA OF MID LEVEL CLOUDS TO THE REGION LATE THIS EVENING AND OVERNIGHT. WEAK WARM AIR ADVECTION WILL ACCOMPANY THE SYSTEM...ALLOWING TEMPERATURES OVERNIGHT TO REMAIN SIMILAR TO EARLY THIS MORNINGS LOWS. CLOUDS WILL PASS THROUGH THE AREA AGAIN WEDNESDAY NIGHT AND THURSDAY WITH CONTINUED WARM AIR ADVECTION AND MOISTURE ADVECTION ON THE BACK SIDE OF THE RIDGE. ONCE AGAIN WITH TONIGHTS RUN...THE NAM IS FASTER WITH SATURATION AT LOWER LEVELS WHILE THE GFS INITIALLY WED NIGHT AND THURSDAY MORNING DOES NOT SHOW SATURATION...BUT LATER IN THE DAY THURSDAY INTO THURSDAY NIGHT/FRIDAY. HAVE OPTED TO MAINTAIN A DRY FORECAST FOR NOW. BUFR SOUNDINGS SHOW MORE WIDESPREAD CLOUDS THURSDAY INTO FRIDAY...WHICH MAY IMPACT MINS AND ESPECIALLY HIGHS BOTH DAYS. FOR NOW...HAVE TRIMMED FRI HIGHS A BIT OVER THE AREA BACK DOWN INTO THE MID TO UPPER 40S CENTRAL TO LOWER 50S WEST/SOUTH. BY SATURDAY SOUTHWEST FLOW WILL PERSIST ACROSS THE ENTIRE REGION WITH READINGS INTO THE LOWER TO MID 50S OVER MOST OF THE SOUTH...UPPER 40S NORTHEAST. STRATUS WILL STILL BE PREVALENT ACROSS THE AREA...BUT MIXING MIGHT PROMOTE SOME BREAKS IN CLOUD COVER. DIFFUSE WARM AIR ADVECTION ALOFT MAY BE ENOUGH TO PRODUCE A FEW LIGHT SHOWERS AS WELL...ESPECIALLY LATER IN THE AFTERNOON WEST INTO SATURDAY NIGHT. MODELS CONTINUE TO SHOW A MORE PRONOUNCED WAVE BY DAYS 6 AND 7 WITH A LEE SIDE TROUGH DEEPENING OVER THE SOUTHERN PLAINS. THE MODELS STILL DIVERGE ON SOLUTIONS WITH THE GFS FARTHER NORTH AND PHASING THE TWO STREAMS WHILE THE EURO IS MORE PROGRESSIVE BUT DOES ALSO ALLOW FOR A RAIN SNOW MIX BY MONDAY. GIVEN THE UNCERTAINTY...WILL MAINTAIN A BLENDED APPROACH UNTIL DETAILS BECOME MORE APPARENT. AFTER A MILD WEEKEND...PASSAGE OF SYSTEM MONDAY WILL USHER IN COOLER TEMPERATURES FOR EARLY NEXT WEEK. && .AVIATION...09/18Z ISSUED AT 1142 AM CST TUE DEC 9 2014 A LARGE REGION OF IFR TO MVFR STRATUS BLANKETS MUCH OF THE UPPER MIDWEST THIS AFTERNOON. A FEW CLEARING SPOTS HAVE DEVELOPED OVER EASTERN IOWA INTO SRN WISCONSIN. SEVERAL OF THE CLEARING PATCHES ARE NEAR SITES HOWEVER AS THE STEERING FLOW SWITCHES FROM THE NORTH TO SOUTHEAST...THE STRATUS WILL SLOW TO STALL FOR A PERIOD. THIS WILL LEAVE SITES ON THE EDGE WITH PERIODS OF REDUCED CEILINGS AND LESSER PERIODS WITH VFR. THE STATUS SHOULD BECOME MORE EXPANSIVE AGAIN TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS TOPEKA KS
249 PM CST Tue Dec 9 2014 .SHORT TERM...(This Evening through Wednesday) Issued at 227 PM CST TUE DEC 9 2014 Surface high pressure continues to build southward today ahead of the next weak shortwave, which will drop southeastward within the northwest flow aloft. Meanwhile the edge of the stratus deck has worked into far northeast KS this morning. The NAM and GFS forecast has kept this stratus from building further into the forecast area later this evening. The latest HRRR and RAP have now developed the stratus further southward towards the I-70 corridor. It appears that the models are cooling that near saturated layer once daytime mixing has stopped. Across central KS with the exception of some high clouds mostly clear skies may allow the boundary layer to cool enough for fog. Although the soundings seem to indicate relatively strong winds just above the surface, which may prevent this from developing. If the stratus develops and or continues in the northeast areas then the forecast lows will probably be too cool. Otherwise most areas should drop into the mid to upper 20s. With regards to precipitation early tomorrow morning. The models have been trending much drier in the lower levels as the lift increases in the saturated layers. The lift appears to be fairly weak and only efficient for drizzle, but with the dry air in place that drizzle will most likely not reach the ground. Temperatures are also forecast to gradually rise tomorrow morning reaching above freezing by late morning or around noon. So freezing precipitation is looking unlikely at this point. Temperatures will warm as the winds veer on the back side of the retreating surface high. There is also an outside chance that if the lift is strong enough to generate rain then sprinkles will be possible as advertised by the ECMWF and GEM. This would most likely occur during the afternoon hours when the wave is forecast to pass over the area. High temperatures tomorrow should reach the around 40 for most locations. .LONG TERM...(Wednesday Night through Tuesday) Issued at 227 PM CST TUE DEC 9 2014 The long term forecast remains cloudy and dreary for the most part with the bulk of the forecast focus on an impending large storm system which should arrive by late Sunday into early next week. For Wednesday night through Saturday, the forecast area will be entrenched in a very moist near-surface airmass. While there will be ridging overhead, it appears that this will only help to keep the surface airmass fairly stagnant through Friday and expect the persistent low clouds to keep temperatures pretty well in check with minimal diurnal temperature swings. There will also be periods of drizzle and fog...particularly overnight and into the morning hours...with weak but persistent lift within the moist layer. The good news is that even with the clouds, temperatures will be above freezing through Saturday night and any light precipitation will fall as liquid. Also, as the weak progresses, southerly low level winds will also advect warmer temperatures into the area to the extent that even without sunshine the area should be in the upper 50s to around 60 for high temperatures Friday through Sunday. Late Saturday into Sunday, a large storm system will be taking shape over the western CONUS, and is scheduled to bring precipitation into the local forecast area by late Sunday. While model guidance is currently in rather strong agreement regarding the evolution of this system, forecaster confidence remains toward the low end. The reason for this low confidence lies in the complex nature of the storm and also the run-to-run model variability over the past few days. The main energy to impact the local area will come from the southwestern CONUS, but will also interact (unsure how much) with a strong northern stream short wave trough. This interaction will strongly impact the atmospheric temperature profiles on the north and northwest side of the storm system and could have a profound impact on the local weather for Sunday night into Monday night. One thing that is certain is that this storm system will not lack moisture as it will have a strong moisture feed ahead of it for several days into the Plains. Current indications are that this event would be mainly rain for the local area with some amounts greater than 1", but could mix with snow or other winter weather types especially across north central KS late in the event. The wild card is in how cold the airmass is behind an incoming cold front that will undercut the system. Lower resolution models can sometimes trend a bit too warm with undercutting cold airmasses in the long range, but lack of snow cover to the north supports a slightly warmer airmass. If it should trend colder there would be more of a chance for winter precip locally. && .AVIATION...(For the 18Z TAFs through 18Z Wednesday Afternoon) Issued at 1148 AM CST TUE DEC 9 2014 The progression of the MVFR ceilings have stopped just northeast of TOP/FOE. The tafs appear to stay VFR through the taf period. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Sanders LONG TERM...Barjenbruch AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1144 AM CST TUE DEC 9 2014 ...UPDATED FOR AVIATION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM CST TUE DEC 9 2014 HIGH LEVEL CLOUD COVER WILL BE LIKELY TODAY ACROSS THE CENTRAL HIGH PLAINS AS A COLD FRONT STALLS OUT IN EXTREME SOUTHWEST KANSAS BY LATE MORNING. CONFIDENCE IS NOT HIGH ON HOW DENSE THESE CLOUDS WILL BE BUT NAM, GFS, AND RAP ALL INDICATE A COOLING TREND IN THE 925MB TO 850MB LEVEL FROM 00Z TUESDAY TO 00Z WEDNESDAY. GIVEN THIS COOLING TREND, MORE CLOUDS TODAY COMPARED TO YESTERDAY, AND AN EASTERLY WIND WILL STAY CLOSE TO THE PREVIOUS FORECAST FOR HIGHS THIS AFTERNOON. TEMPERATURES CLIMBING INTO THE UPPER 50S TO NEAR 60 STILL LOOKS REASONABLE IN EXTREME SOUTHWEST KANSAS WHICH WILL BE NEAR/SOUTH OF THE COLD FRONT WHILE HIGHS ONLY IN THE MID 40S IN NORTH CENTRAL KANSAS. EXACTLY HOW THE GRADIENT WILL END UP BETWEEN THESE TWO EXTREMES IS UNCLEAR. ISENTROPIC AND MOISTURE ADVECTION WILL IMPROVE ACROSS WESTERN KANSAS IN THE 900MB TO 800MB LEVEL. STRATUS ALONG WITH POSSIBLY SOME AREAS OF FOG APPEARING LIKELY AS THE LOWER LEVELS SATURATE OVERNIGHT. DEPTH OF THIS MOIST LAYER WILL BE IN THE 2000 TO 3000 FT AGL RANGE DEPENDING ON WHICH MODEL SOUNDING YOU EXAMINE. GIVEN THE DEPTH OF THIS LAYER AM TRENDING AWAY FROM INTRODUCING DRIZZLE LATE TONIGHT BUT IF THE NAM ENDS UP BEING MORE CORRECT THEN SOME PATCHY DRIZZLE COULD DEVELOP TOWARDS DAYBREAK. TEMPERATURES ARE EXPECTED TO FALL TO AROUND 32 DEGREES BUT GIVEN THE INCREASE IN LOW LEVEL MOISTURE FORECAST OVERNIGHT THE LOWS MAY OCCUR EARLY WITH TEMPERATURES THEN HOLDING NEARLY STEADY OR EVEN RISE A FEW DEGREES AFTER MIDNIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 358 AM CST TUE DEC 9 2014 THE PERIOD BETWEEN WEDNESDAY AND SATURDAY WILL BE A TRUE CHALLENGE WITH RESPECT TO SKY COVER AND RESULTING TEMPERATURES BOTH IN THE DAYTIME FOR HIGHS AS WELL AS LOWS OVERNIGHT. RELATIVELY MORE MOIST CONDITIONS IN THE BOUNDARY LAYER MARKED BY DEW POINTS IN THE UPPER 30S AND 40S COULD CONTRIBUTE TO EVENING/NIGHT FOG DEVELOPMENT IN ADDITION TO ALREADY EXPECTED STRATUS. STRATUS THAT DOES ERODE DURING THE DAY SHOULD BE ABLE RAPIDLY REDEVELOP ACROSS MUCH OF CENTRAL KANSAS INTO THE EVENING AS THE BOUNDARY LAYER COOLS DIURNALLY. MODELS SOUNDINGS GENERALLY LIMIT THE THICKNESS TO SLIGHTLY MORE THAN 2000 FT, WHICH IS NOT FAVORABLE FOR DRIZZLE DESPITE MODEL QPF OUTPUT. THE PRIMARY CHALLENGE WILL BE DETERMINING HOW FAR WEST THE STRATUS IMPACTS THE FORECAST AREA EACH DAY AND IT`S EFFECT ON TEMPERATURES. WEDNESDAY INTO THURSDAY NIGHT APPEARS LIKELY TO BRING THE MOST WIDESPREAD OVERCAST CONDITIONS, WHILE THE WESTERN MOST COUNTIES, GENERALLY WEST OF HIGHWAY 83 WILL EXPERIENCE THE MOST HOURS OF INSOLATION AND CLEAR SKIES DURING THIS TIMEFRAME. UNLESS THE MODELS SIGNIFICANTLY DIVERGE IN SOLUTIONS FROM THE CURRENT AND RECENT RUNS, SUNDAY NIGHT (OR AROUND THAT SYNOPTIC TIMESCALE/TIMEFRAME) LOOKS WET WITH RAIN POTENTIAL OR EVEN SNOW WITH AS UPPER DYNAMIC LOW PRESSURE MOVING THROUGH OR JUST SOUTH OF THE REGION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1136 AM CST TUE DEC 9 2014 AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS INTO EASTERN KANSAS TONIGHT, SURFACE WINDS WILL BECOME SOUTHEASTERLY UPSLOPE AROUND 8-10KT ACROSS WESTERN KANSAS. SOME IFR/LIFR CONDITIONS ARE POSSIBLE BY 11-13Z ACROSS MUCH OF WESTERN KANSAS WITH LIGHT FREEZING FOG AND LOW CIGS. LOW CONDITIONS WILL GRADUALLY IMPROVE BY 16-18Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 49 33 47 41 / 0 10 10 10 GCK 52 31 50 37 / 0 10 0 0 EHA 59 34 57 35 / 0 0 0 0 LBL 56 36 56 44 / 0 10 0 0 HYS 42 29 43 38 / 0 10 10 10 P28 49 31 46 41 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...RUSSELL AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
329 PM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE OFF THE COAST OF DELMARVA WILL STALL OVER LONG ISLAND TONIGHT THROUGH WEDNESDAY...BEFORE DRIFTING NORTH OVER NEW ENGLAND THROUGH FRIDAY. THE LOW THEN PUSHES OUT TO SEA INTO NEXT WEEK. HIGH PRESSURE WILL BUILD OVER THE MID-ATLANTIC FRIDAY THROUGH MONDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A FEW DEVELOPMENTS THIS MORNING TO TAKE NOTE OF. PERSISTENT NORTHERLY FLOW BEING USHERED IN ON THE WEST SIDE OF THE SFC LOW JUST OFFSHORE IS KEEPING PLENTY OF COLDER AIR IN PLACE. INITIAL THOUGHT HAD BEEN OF THE SFC TEMPS WARMING IN THE AREA TO AT LEAST MID 30S. BUT WITH TEMPS TO THE NORTH STILL SHOWING LOWER 30S...AND WITH MULTIPLE MESO REPORTS SHOWING AROUND FREEZING IN OUR AREA...THE LATEST THINKING IS THAT UNTIL THE WIND SHIFT TO THE NW LATE TODAY...WE SHALL SEE PERSISTING FREEZING SFC TEMPS. ADD IN THE ON GOING PCPN AND FREEZING RAIN REMAINS A THREAT OVER CENTRAL MD...AND BLUE RIDGE AREAS AND TO THE WEST. 12Z RAP SOUNDINGS ALSO SHOWING PLENTY OF DRYING ALOFT...SO VERY WELL COULD END UP WITH JUST LIGHT DRIZZLE/FREEZING DRIZZLE. THUS...HAVE REISSUED A WINTER WEATHER ADVISORY FOR THESE AREAS TO ACCOUNT FOR ANY ADDITIONAL ICE ACCUM...GENERALLY ONLY EXPECTING LIGHT AMTS...COUPLE HUNDREDTHS OF AN INCH OR LESS...ON TOP OF THE CURRENTLY REPORTED ICE TOTALS WE HAVE BEEN RECEIVING...WITH ISOLATED SPOTS UP TO A COUPLE TENTHS OF AN INCH. THIS ADVISORY IS IN EFFECT UNTIL 23Z. THE QUESTION BECOMES THEN FOR TONIGHT THE CHC FOR PCPN AND THE FORM OF PCPN. GENERAL THOUGHT IS WITH THE WIND SHIFT TO A MORE DEFINED NW FLOW...SHOULD SEE A TRANSITION TO UPSLOPING LIGHT SNOW SHOWERS AND THE FREEZING RAIN/DRIZZLE THREAT DIMINISHING. SO FOR NOW HAVE NOT CONTINUED THE ADVISORY THROUGH THE NIGHT TO ACCOUNT FOR THE PCPN CHANGEOVER. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... BLUSTERY CONDS WL CONT TNGT AND WED AS THE LOW TRACKS OVR LONG ISLAND...AND THEN NEW ENGLAND BRINGING A PROLONGED PD OF UNSETTLED WX TO THE NERN U.S. TYPICALLY STRONG LOWS THAT FAR TO OUR N ARE NOT BIG PCPN PRODUCERS IN THE MID ATLC..BUT WL KEEP CHC POPS IN THE FCST. A STREAMER ALONG THE BAY SOMETIMES OCCURS IN THIS SITUATION. THE BIGGER STORY WL BE THE WINDY CONDS THAT WL CONT BOTH TNGT AND WED COURTESY OF THE PRES GRAD BTWN THE NERN LOW AND HIGH PRES OVR THE MS VLLY. LOWS TNGT IN THE 30S. HIGHS WED IN THE 40S. && .LONG TERM /THURSDAY THROUGH TUESDAY/... WE WILL STILL FEEL THE EFFECTS OF THE LOW OVER NEW ENGLAND THURSDAY AND FRIDAY. HOWEVER...THE BUILDING RIDGE OVER THE CNTRL CONUS SHOULD SHUNT WRAP AROUND MOISTURE/CLOUDS/PRECIP EAST OF THE AREA BY FRIDAY. ALSO...THE PRESSURE GRADIENT SHOULD BE WEAKER FRIDAY. THURSDAY...STRONG NWLY FLOW CONTINUES...EXPECT GUSTS IN THE 25 TO 30 MPH RANGE (HIGHER ON RIDGES)...5 TO 10 MPH LESS THAN WEDNESDAY. DOWNSLOPING FLOW SO TEMPERATURES WILL MAX OUT IN THE UPR 30S TO LOW 40S. THE REACH OF THE UPPER LOW STILL GETS SOUTH OF THE MASON-DIXON...SO SOME LIGHT SHOWERS/FLURRIES ARE POSSIBLE... PARTICULARLY NORTH OF HWY 50/I-66. UPSLOPE SNOW CONTINUES...BUT THE INVERSION BECOMES MORE SHALLOW...AN INCH OR LESS POSSIBLE. FRIDAY...DRIER WITH LESS PRESSURE GRADIENT. MAX TEMPS LOW TO MID 40S...UPSLOPE SNOW PROBABLY CUTS OFF THURSDAY NIGHT. NW WINDS GUST TO AROUND 20 MPH. THE LONG TERM PERIOD SHOULD BE RATHER QUIET AS FAR AS PRECIPITATION IS CONCERNED.. HIGH PRESSURE OVER LABRADOR WILL BLOCK THE COASTAL LOW...CAUSING IT TO STALL NEAR NEW ENGLAND THROUGH THE END OF THE WEEK BEFORE MOVING OUT TO SEA SUNDAY. THIS WILL KEEP US IN BREEZY NORTH TO NORTHWESTERLY FLOW WITH A DECENT AMOUNT OF CLOUD COVER INTO SATURDAY NIGHT...MEANING THAT FRIDAY AND SATURDAY WILL FEEL LIKE BLUSTERY MID-ATLANTIC WINTER DAYS. RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE BUILDING IN FROM THE SOUTH OVER THE WEEKEND WILL CLEAR SKIES TO MOSTLY SUNNY SUNDAY AND MONDAY AS WELL AS ALLOW WINDS TO WEAKEN AND TEMPS TO MODERATE. MODELS DIVERGE ON AN AREA OF LOW PRESSURE AT THE VERY END OF THE PERIOD...WITH THE GFS MIGRATING OUR HIGH SOUTHWARD...BRINGING A MID-LATITUDE LOW TO OUR NORTH...AND A COLD FRONT THROUGH THE MID-ATLANTIC. THE EURO FAVORS THE HIGH MIGRATING SOUTHWARD AND THE FORMATION OF A SOUTHERN STREAM LOW. CONFIDENCE IS LOW IN EITHER SOLUTION HAVING MUCH IMPACT BEFORE TUESDAY NIGHT ASIDE FROM AN INCREASE IN CLOUD COVER. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/... GENERALLY MVFR CONDITIONS ACROSS THE TERMINALS...WITH WESTERN SITES EVEN AT VFR NOW. IMPROVEMENT LOOKS TO BE SLOW TODAY...WITH ALL SITES BECOMING VFR BY THIS EVENING. LOW-MOD CONFIDENCE AT THE MOMENT ON THE IMPROVEMENT TIME. ANY PCPN AT THE TERMINALS SHOULD REMAIN LIGHT RAIN/DRIZZLE DURING THIS TIME UNTIL TONIGHT...WITH PSBL LIGHT SNOW MIXING IN THIS EVENING. N WINDS BECOME NW THIS AFTN...WITH OCNL GUSTS MIXING IN DURING THE AFTN HOURS. VFR CONDS XPCTD FOR THE EVE PUSH AND THEN OVR AND WED. GUSTY N WINDS XPCTD TO CONT THRU WED. A LARGE UPPER-LEVEL LOW WILL BE ROTATING JUST EAST OF THE AREA...OFF THE MID-ATLC NEW ENGLAND COAST FOR MUCH OF THE WEEK. GUSTY WINDS FROM TUE NIGHT INTO WED. A FEW GUSTS WILL REMAIN INTO THU BUT MAINLY TAPERING OFF AFTER A WINDY WED. STRONG NW WINDS AND VFR PREVAIL THURSDAY AND FRIDAY. GUSTS TO 30 KT ON THURSDAY AND AROUND 20 KT ON FRIDAY. && .MARINE... WINDS REACHING SCA LVLS TODAY THRU WED. GALE GUSTS MAY OCCUR ON WED. WHILE AN OFFSHORE UPPER LOW ROTATES JUST OFF THE MID-ATLC COAST...THE SFC PRESSURE GRADIENT WILL INCREASE AND CAUSE ANOTHER ROUND OF HIGH-END SCA WED NIGHT. SOME BREEZES STILL OCCURRING ON THU AS THE UPPER LOW SLOWLY WEAKENS AND MOVES OFF THE COAST NIGHT. STRONG NW WIND CONTINUE THURSDAY ACROSS THE WATERS. FOR NOW...EXPECT 30 KT GUSTS...WILL NEED TO WATCH FOR BRIEF GALES CONTINUING FROM WEDNESDAY. SCA ANTICIPATED THURSDAY INTO FRIDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ004. VA...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ501- 505-507-508. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST THURSDAY FOR ANZ530>543. && $$ SYNOPSIS...BAJ/SEARS NEAR TERM...SEARS SHORT TERM...SEARS LONG TERM...BAJ/CEB AVIATION...BAJ/SEARS MARINE...BAJ/SEARS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1124 AM EST TUE DEC 9 2014 .SYNOPSIS... LOW PRESSURE OFF THE COAST OF DELMARVA WILL PUSH NORTH TODAY...REACHING LONG ISLAND THIS EVENING. THE LOW IS EXPECTED TO REMAIN NEARLY STATIONARY OVER NEW ENGLAND WEDNESDAY AND THURSDAY. HIGH PRESSURE WILL MOVE OVER THE MID ATLANTIC THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A FEW DEVELOPMENTS THIS MORNING TO TAKE NOTE OF. PERSISTENT NORTHERLY FLOW BEING USHERED IN ON THE WEST SIDE OF THE SFC LOW JUST OFFSHORE IS KEEPING PLENTY OF COLDER AIR IN PLACE. INITIAL THOUGHT HAD BEEN OF THE SFC TEMPS WARMING IN THE AREA TO AT LEAST MID 30S. BUT WITH TEMPS TO THE NORTH STILL SHOWING LOWER 30S...AND WITH MULTIPLE MESO REPORTS SHOWING AROUND FREEZING IN OUR AREA...THE LATEST THINKING IS THAT UNTIL THE WIND SHIFT TO THE NW LATE TODAY...WE SHALL SEE PERSISTING FREEZING SFC TEMPS. ADD IN THE ON GOING PCPN AND FREEZING RAIN REMAINS A THREAT OVER CENTRAL MD...AND BLUE RIDGE AREAS AND TO THE WEST. 12Z RAP SOUNDINGS ALSO SHOWING PLENTY OF DRYING ALOFT...SO VERY WELL COULD END UP WITH JUST LIGHT DRIZZLE/FREEZING DRIZZLE. THUS...HAVE REISSUED A WINTER WEATHER ADVISORY FOR THESE AREAS TO ACCOUNT FOR ANY ADDITIONAL ICE ACCUM...GENERALLY ONLY EXPECTING LIGHT AMTS...COUPLE HUNDREDTHS OF AN INCH OR LESS...ON TOP OF THE CURRENTLY REPORTED ICE TOTALS WE HAVE BEEN RECEIVING...WITH ISOLATED SPOTS UP TO A COUPLE TENTHS OF AN INCH. THIS ADVISORY IS IN EFFECT UNTIL 23Z. THE QUESTION BECOMES THEN FOR TONIGHT THE CHC FOR PCPN AND THE FORM OF PCPN. GENERAL THOUGHT IS WITH THE WIND SHIFT TO A MORE DEFINED NW FLOW...SHOULD SEE A TRANSITION TO UPSLOPING LIGHT SNOW SHOWERS AND THE FREEZING RAIN/DRIZZLE THREAT DIMINISHING. SO FOR NOW HAVE NOT CONTINUED THE ADVISORY THROUGH THE NIGHT TO ACCOUNT FOR THE PCPN CHANGEOVER. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... BLUSTERY CONDS WL CONT TNGT AND WED AS THE LOW TRACKS OVR LONG ISLAND...AND THEN NEW ENGLAND BRINGING A PROLONGED PD OF UNSETTLED WX TO THE NERN U.S. TYPICALLY STRONG LOWS THAT FAR TO OUR N ARE NOT BIG PCPN PRODUCERS IN THE MID ATLC..BUT WL KEEP CHC POPS IN THE FCST. A STREAMER ALONG THE BAY SOMETIMES OCCURS IN THIS SITUATION. THE BIGGER STORY WL BE THE WINDY CONDS THAT WL CONT BOTH TNGT AND WED COURTESY OF THE PRES GRAD BTWN THE NERN LOW AND HIGH PRES OVR THE MS VLLY. LOWS TNGT IN THE 30S. HIGHS WED IN THE 40S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LIKE THE CONSUMMATE EXAMPLE OF THE ANGULAR MOMENTUM LOST W/ A WEAKENING LOW PRESSURE SYSTEM...THE VERTICALLY STACKED COASTAL LOW WILL EXPAND BUT LOSE MUCH OF ITS POTENCY LATE IN THE WORK WEEK. AFTER THE REINFORCING VORT MAX THAT IS CURRENTLY STRENGTHENING THE SYSTEM PHASES OUT LATER TODAY...THE SYSTEM WILL NOT HAVE MUCH ELSE TO CONTINUE ITS INTENSE PRESENCE. THE LACK OF WAA/CAA WILL TAKE ITS TOLL ON THE SYSTEM...RISING HEIGHTS IN THE UPPER LOW AND SCATTERING OUT THE PRECIP AS IT HOVERS OVER NEW ENGLAND FROM LATE WED INTO THU. THE OFFSHORE PRECIP WILL MOVE FURTHER AWAY FROM LAND...W/ THE ONSHORE PRECIP WEAKLY FORCED AND LIMITED TO THE LEFTOVER CIRCULAR OUTER BANDS - SURROUNDING THE LOW. MUCH OF THE PRECIP WILL STAY NORTH OF THE MASON-DIXON LINE...OUTSIDE OF A FEW BATCHES OF UPSLOPE SHOWERS AND SNOW SHOWERS DURING THE LATE STAGES OF THE LOW`S INFLUENCE. SOME PROLONGED ACCUMULATING SNOWS FOR THE HIGHER TERRAIN WILL NEED TO BE MONITORED FOR THE APLCN SPINE... W/ MUCH OF THE REST OF THE MID ATLC DRYING OUT. THE PROXIMITY OF THE LARGE AND WEAKENING UPPER LOW LATE IN THE WEEK WILL KEEP OUR WX MODERATED - NOT MUCH OF A WARM-UP EXPECTED. AVG HIGHS ARE IN THE U40S FOR OUR REGION FOR THIS TIME OF YEAR WE WILL HAVE TO WAIT FOR THE COMING WEEKEND TO APPROACH THESE VALUES...W/ A SLOW/STEADY CLIMB UNTIL THEN. SINCE LAST NIGHT...THE EURO INTO THE END OF THE WEEK HAS ACTUALLY MOVED TOWARD THE GFS SOLUTION...THEN THEY DIVERGE AGAIN INTO THE WEEKEND. AS THE PARENT UPPER LOW SLOWLY WEAKENS AND LOSES ITS EARLIER POTENCY...THE OUTER PRECIP BANDS WILL CONTINUE TO EXPAND AND DISSIPATE AS THEY ROTATE AROUND NEW ENGLAND. PLENTY OF LIGHT PRECIP WILL SWING ABOUT THE CENTER OF THE LOW...BUT LITTLE IF ANY WILL MAKE IT SOUTH OF THE MASON-DIXON LINE. THE GFS TAKES THAT ENTIRE SYSTEM ON A GOOD NE JOG INTO THE WEEKEND...WHILE THE EURO KEEPS THE FEATURE OVER SRN NEW ENGLAND...W/ ANOTHER MINOR DEEPENING PERIOD TO TIME - JUST OFF THE MID ATLC. KEEPING THE LATEST FORECAST UPDATE W/ A BLEND OF THE LONG RANGE DEPICTIONS...MAINLY A SLOW WARM-UP AND DRY FOR THE AREA INTO EARLY NEXT WEEK. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... GENERALLY MVFR CONDITIONS ACROSS THE TERMINALS...WITH WESTERN SITES EVEN AT VFR NOW. IMPROVEMENT LOOKS TO BE SLOW TODAY...WITH ALL SITES BECOMING VFR BY THIS EVENING. LOW-MOD CONFIDENCE AT THE MOMENT ON THE IMPROVEMENT TIME. ANY PCPN AT THE TERMINALS SHOULD REMAIN LIGHT RAIN/DRIZZLE DURING THIS TIME UNTIL TONIGHT...WITH PSBL LIGHT SNOW MIXING IN THIS EVENING. N WINDS BECOME NW THIS AFTN...WITH OCNL GUSTS MIXING IN DURING THE AFTN HOURS. VFR CONDS XPCTD FOR THE EVE PUSH AND THEN OVR AND WED. GUSTY N WINDS XPCTD TO CONT THRU WED. A LARGE UPPER-LEVEL LOW WILL BE ROTATING JUST EAST OF THE AREA...OFF THE MID-ATLC NEW ENGLAND COAST FOR MUCH OF THE WEEK. GUSTY WINDS FROM TUE NIGHT INTO WED. A FEW GUSTS WILL REMAIN INTO THU BUT MAINLY TAPERING OFF AFTER A WINDY WED. && .MARINE... WINDS REACHING SCA LVLS TODAY THRU WED. GALE GUSTS MAY OCCUR ON WED. WHILE AN OFFSHORE UPPER LOW ROTATES JUST OFF THE MID-ATLC COAST...THE SFC PRESSURE GRADIENT WILL INCREASE AND CAUSE ANOTHER ROUND OF HIGH-END SCA WED NIGHT. SOME BREEZES STILL OCCURRING ON THU AS THE UPPER LOW SLOWLY WEAKENS AND MOVES OFF THE COAST NIGHT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ003>005-502-503-505. VA...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ025>031-040-501-505-507-508. WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ051>053. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ530>543. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 PM EST TUE DEC 9 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 346 PM EST TUE DEC 9 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR TROF STRETCING S FM HUDSON BAY INTO THE SE CONUS DOWNSTREAM OF AN UPR RDG IN THE PLAINS. SFC HI PRES UNDER THE THE UPR RDG STRETCHES FM NW ONTARIO INTO MN. 12HR 00Z-12Z H5 HGT RISES IN THE 100-150M RANGE FM YPL TO INL AND MPX INDICATE THE UPR RDG/SFC HI ARE BUILDING INTO THE WRN GREAT LKS...BUT PLENTY OF LO CLDS/A FEW FLURRIES LINGER OVER THE CWA EARLY THIS AFTN WITH LLVL MSTR TRAPPED IN NEAR SFC NNE FLOW OFF LK SUP UNDER INVRN BASE THAT HAD LOWERED TO NEAR H95 BY 12Z AT INL UNDER THE STRONG DNVA/SUBSIDENCE ASSOCIATED WITH THE INCOMING UPR RDG. THE AIR TO THE N OF LK SUP IS QUITE A BIT DRIER PER THE 12Z YPL RAOB...WITH SFC DEWPTS NEAR OR BLO 0F AT MOST PLACES IN ONTARIO. SKIES ARE MOCLR THERE...AND ASSOCIATED DRYING IS TENDING TO BREAK UP THE LO CLDS OVER THE NRN AND ERN PORTION OF LK SUP. BUT THIS CLRG IS HAVING A HARD TIME MAKING MUCH PROGRESS TOWARD UPR MI. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LO CLD TRENDS AND IMPACT ON TEMPS. TNGT...AS UPR RDG CONTINUES TO SHIFT SLOWLY TO THE E...SFC HI PRES RDG IS FCST TO DRIFT SLOWLY E AS WELL...REACHING A LINE FM NEAR JAMES BAY INTO NW WI BY 12Z WED. LOWERING INVRN BASE UNDER THE ASSOCIATED SUBSIDENCE SHOULD END ANY LINGERING FLURRIES...BUT MODELS HAVE TRENDED TO BE MORE PESSIMISTIC IN REGARDS TO CLEARING THE LO CLDS...WHICH SEEMS CONSISTENT WITH RATHER SLOW OBSVD CLRG TREND. BEST CHC FOR SOME CLRG WL BE OVER THE ERN CWA AS THE SLOWLY VEERING LLVL FLOW TOWARD THE E WL DOWNSLOPE OFF ONTARIO AND LIMIT THE OVER WATER TRAJECTORY. ONE OTHER AREA WHERE THERE MAY BE SOME CLRG IS OVER THE FAR W...WHERE FLOW SHIFTING TOWARD THE SSE WL DOWNSLOPE AS WELL. BUT THE SFC-H925 WINDS ARE FCST TO BE ONLY 5-10 KTS...SO THE ASSOCIATED SUBSIDENCE MIGHT NOT BE SUFFICIENT TO BREAK UP THE LO CLDS SIGNIFICANTLY. WL TEND TOWARD THE LOWEST MIN TEMPS OVER THE INTERIOR E...WITH LINGERING CLDS HOLDING UP THE TEMPS ELSEWHERE. WED...SFC HI PRES RDG AXIS IS PROGGED TO DRIFT ONLY SLOWLY E THRU THE DAY...REMAINING OVER CENTRAL UPR MI THRU THE DAY. WITH CONTINUED SUBSIDENCE...EXPECT LINGERING LO CLDS TO SLOWLY BREAK UP. THESE CLDS SHOULD BE MOST PERSISTENT OVER THE HIER TERRAIN OF THE CENTRAL CWA...BUT EVEN HERE THE CLDS SHOULD BREAK UP AS THE SUBSIDENCE INVRN SINKS TO THE NEAR THE SFC AS SHOWN ON FCST SDNGS. TENDED TOWARD THE LO END OF GUIDANCE FOR MAX TEMPS GIVEN HI STABILITY SHOWN ON FCST SDNGS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 402 PM EST TUE DEC 9 2014 WEDNESDAY NIGHT THROUGH SATURDAY...A SURFACE RIDGE AND DRY AIR WILL LINGER ACROSS MUCH OF THE MIDWEST AND UPPER GREAT LAKES REGION THROUGH SATURDAY BEFORE SHIFTING SLOWLY TO THE SOUTHEAST. AT THE SAME TIME...STRONG UPPER LEVEL 500MB RIDGING OVER THE PLAINS STATES WEDNESDAY NIGHT WILL SHIFT SLOWLY EASTWARD WITH THE UPPER LEVEL RIDGE AXIS BECOMING DIRECTLY OVERHEAD LATE FRIDAY NIGHT THROUGH MUCH OF THE DAY SATURDAY. THIS WILL TRANSLATE TO MAINLY CLEAR...DRY AND VERY QUIET WEATHER THROUGH THIS TIME PERIOD. TEMPERATURES WILL WARM TO WELL ABOVE NORMAL FRIDAY INTO SATURDAY WITH HIGHS APPROACHING OR EXCEEDING 40 DEGREES AS 850MB TEMPERATURES WARM TO AROUND 10 TO 12C. SATURDAY NIGHT THROUGH TUESDAY...AS THE UPPER LEVEL RIDGE AXIS SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT INTO SUNDAY...EXPECT HEIGHTS TO SLOWLY FALL ACROSS THE AREA. AT THE SAME TIME...A WEAK SURFACE TROUGH IS EXPECTED TO SLIDE ACROSS THE AREA. OVERALL MOISTURE DOES NOT APPEAR TO OVERLY ABUNDANT OR DEEP...AS A LOW IS EXPECTED TO DEVELOP OVER THE OKLAHOMA PANHANDLE...HELPING TO FOCUS THE BETTER MOISTURE OVER THE SOUTH. THE WARMER TEMPERATURES DURING THIS TIME PERIOD WILL KEEP THE PRECIPITATION MAINLY IN THE FORM VERY LIGHT RAIN OR DRIZZLE...HOWEVER...IT IS POSSIBLE THAT A FEW INLAND AREAS COULD SEE LIGHT FREEZING DRIZZLE LATE SATURDAY NIGHT. WOULD NOT EXPECT TOO MUCH OF AN IMPACT ON ROADWAYS WITH THE WARMER DAYTIME HIGHS ACROSS THE AREA. AT THIS POINT...WENT WITH THE VERY LIGHT RAIN MENTION...WITH DROPLETS EXPECTED TO BE FAIRLY SMALL AS MOISTURE IS NOT DEEP ENOUGH FOR RAINFALL TO AMOUNT TO MUCH. MODELS BEGIN TO DIVERGE ON THE PLACEMENT OF THE SOUTHERN LOW THROUGH THE REMAINING EXTENDED WITH THE 06Z GFS BRINGING THE LOW TO THE NORTHEAST REACHING SOUTHEASTERN LOWER MI BY MONDAY NIGHT WHILE THE EC KEEPS THE LOW MUCH FARTHER SOUTH...AROUND SOUTHEAST MISSOURI AT THE SAME TIME. THE LATEST...12Z MODEL RUN OF THE GFS/EC ARE IN BETTER AGREEMENT WITH THE MORE SOUTHERLY TRACK. BOTH MODELS ALSO AGREE WITH A COLD FRONT PUSHING THROUGH THE UPPER GREAT LAKES REGION LATE SUNDAY NIGHT INTO MONDAY...WITH BROAD UPPER LEVEL TROUGHING PUSHING ACROSS THE AREA MONDAY NIGHT INTO TUESDAY ALLOWING TEMPERATURES TO COOL ONCE AGAIN. THIS WILL ALSO ALLOW THE PRECIPITATION TO TRANSITION BACK TO SNOW FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA. ADDITIONALLY...WITH THE COOLER AIR PUSHING INTO THE AREA AND 850MB TEMPS FALLING TO AROUND -8 TO -10C MONDAY NIGHT INTO TUESDAY EXPECT TO SEE LIGHT LAKE EFFECT DEVELOP...THIS WOULD BE SHORT-LIVED AS ANOTHER RIDGE BEGINS TO BUILD ACROSS THE PLAINS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1233 PM EST TUE DEC 9 2014 A DIFFICULT LO CLD FCST IS ON TAP FOR THE TAF SITES. LINGERING LLVL MSTR IN UPSLOPE NNE FLOW OFF LK SUP AND UNDER LOWERING SUBSIDENCE INVRN ASSOCIATED WITH BLDG UPR RDG IS CAUSING THE LO CLDS OBSVD TODAY. ALTHOUGH SOME NEAR SFC DRYING WL CAUSE THE CIGS TO RUN GENERALLY IN THE MVFR RANGE...THE LO CLDS SHOULD PERSIST THRU THIS EVNG AT ALL 3 SITES. THE BEST CHC FOR SOME CLRG AND A RETURN TO VFR WX WL BE AT SAW AND IWD LATER TNGT AS THE LLVL FLOW VEERS SLOWLY TO A MORE ESE DIRECTION THAT WL DOWNSLOPE INTO IWD AND LIMIT MOISTENING OFF LK SUP INTO SAW. A MORE UPSLOPE WIND COMPONENT AND SOME MOISTENING OFF LK SUP AT CMX WL LIKELY CAUSE THE MVFR CIGS TO LINGER THERE THRU THE ENTIRE FCST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 PM EST TUE DEC 9 2014 HIGH PRESSURE WILL SETTLE OVER THE UPPER GREAT LAKES TONIGHT AND LINGER THROUGH FRIDAY ALLOWING WINDS TO DROP OFF TO UNDER 15KT. THESE LIGHTER WINDS WILL LIKELY LINGER INTO SATURDAY. LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL PASS THROUGH THE REGION SUNDAY NIGHT THROUGH MONDAY ALLOWING WINDS TO INCREASE ONCE AGAIN FROM THE NORTH. AT THIS POINT WINDS ARE EXPECTED TO REMAIN BELOW 25 KNOTS SUNDAY NIGHT THROUGH MONDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...KC MARINE...KEC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
348 PM EST TUE DEC 9 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 346 PM EST TUE DEC 9 2014 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR TROF STRETCING S FM HUDSON BAY INTO THE SE CONUS DOWNSTREAM OF AN UPR RDG IN THE PLAINS. SFC HI PRES UNDER THE THE UPR RDG STRETCHES FM NW ONTARIO INTO MN. 12HR 00Z-12Z H5 HGT RISES IN THE 100-150M RANGE FM YPL TO INL AND MPX INDICATE THE UPR RDG/SFC HI ARE BUILDING INTO THE WRN GREAT LKS...BUT PLENTY OF LO CLDS/A FEW FLURRIES LINGER OVER THE CWA EARLY THIS AFTN WITH LLVL MSTR TRAPPED IN NEAR SFC NNE FLOW OFF LK SUP UNDER INVRN BASE THAT HAD LOWERED TO NEAR H95 BY 12Z AT INL UNDER THE STRONG DNVA/SUBSIDENCE ASSOCIATED WITH THE INCOMING UPR RDG. THE AIR TO THE N OF LK SUP IS QUITE A BIT DRIER PER THE 12Z YPL RAOB...WITH SFC DEWPTS NEAR OR BLO 0F AT MOST PLACES IN ONTARIO. SKIES ARE MOCLR THERE...AND ASSOCIATED DRYING IS TENDING TO BREAK UP THE LO CLDS OVER THE NRN AND ERN PORTION OF LK SUP. BUT THIS CLRG IS HAVING A HARD TIME MAKING MUCH PROGRESS TOWARD UPR MI. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LO CLD TRENDS AND IMPACT ON TEMPS. TNGT...AS UPR RDG CONTINUES TO SHIFT SLOWLY TO THE E...SFC HI PRES RDG IS FCST TO DRIFT SLOWLY E AS WELL...REACHING A LINE FM NEAR JAMES BAY INTO NW WI BY 12Z WED. LOWERING INVRN BASE UNDER THE ASSOCIATED SUBSIDENCE SHOULD END ANY LINGERING FLURRIES...BUT MODELS HAVE TRENDED TO BE MORE PESSIMISTIC IN REGARDS TO CLEARING THE LO CLDS...WHICH SEEMS CONSISTENT WITH RATHER SLOW OBSVD CLRG TREND. BEST CHC FOR SOME CLRG WL BE OVER THE ERN CWA AS THE SLOWLY VEERING LLVL FLOW TOWARD THE E WL DOWNSLOPE OFF ONTARIO AND LIMIT THE OVER WATER TRAJECTORY. ONE OTHER AREA WHERE THERE MAY BE SOME CLRG IS OVER THE FAR W...WHERE FLOW SHIFTING TOWARD THE SSE WL DOWNSLOPE AS WELL. BUT THE SFC-H925 WINDS ARE FCST TO BE ONLY 5-10 KTS...SO THE ASSOCIATED SUBSIDENCE MIGHT NOT BE SUFFICIENT TO BREAK UP THE LO CLDS SIGNIFICANTLY. WL TEND TOWARD THE LOWEST MIN TEMPS OVER THE INTERIOR E...WITH LINGERING CLDS HOLDING UP THE TEMPS ELSEWHERE. WED...SFC HI PRES RDG AXIS IS PROGGED TO DRIFT ONLY SLOWLY E THRU THE DAY...REMAINING OVER CENTRAL UPR MI THRU THE DAY. WITH CONTINUED SUBSIDENCE...EXPECT LINGERING LO CLDS TO SLOWLY BREAK UP. THESE CLDS SHOULD BE MOST PERSISTENT OVER THE HIER TERRAIN OF THE CENTRAL CWA...BUT EVEN HERE THE CLDS SHOULD BREAK UP AS THE SUBSIDENCE INVRN SINKS TO THE NEAR THE SFC AS SHOWN ON FCST SDNGS. TENDED TOWARD THE LO END OF GUIDANCE FOR MAX TEMPS GIVEN HI STABILITY SHOWN ON FCST SDNGS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 346 AM EST TUE DEC 9 2014 AN UPPER RIDGE WILL BUILD OVER THE CWA THROUGH SAT AS A SFC RIDGE SITS OVER THE CWA BEFORE MOVING SE FRI INTO SAT. THIS WILL KEEP CONDITIONS ON THE QUIET SIDE WITH NO PRECIP EXPECTED THROUGH 00Z SUN. WED NIGHT LOOKS TO BE THE COLDEST NIGHT WITH SINGLE DIGIT ABOVE ZERO LOWS INLAND AS THE RIDGE WILL BE OVERHEAD AND THE SIGNIFICANTLY WARMER AIRMASS IS STILL TO THE W. 850MB TEMPS WILL BE ON THE RISE FROM AOB 0C AT 12Z WED TO AOA 10C BY 00Z SAT...WITH THE WARMER TEMPS STICKING AROUND THROUGH SAT. WARMEST TEMPS EXPECTED ON SAT WITH HIGHS FROM THE UPPER 30S TO LOW 40S. WHILE THERE IS A LOT OF UNCERTAINTY WITH THE TRANSITION INTO A MORE ACTIVE PATTER LATE IN THE WEEKEND...IT DOES LOOK LIKE SOME LIGHT PRECIP IS POSSIBLE SOMETIME SUN INTO MON...AND PTYPE WILL TRANSITION BACK TO SNOW AT LEAST OVER PORTIONS OF THE AREA BY MON. LOTS WILL DEPEND ON THE TRACK/STRENGTH OF UPPER LEVEL ENERGY WHICH MODELS VARY SUBSTANTIALLY FROM RUN TO RUN. STILL NOT BUYING GREATER QPF/LOW LEVEL MOISTURE THAT MODELS SHOW ON SUN/SUN NIGHT AS MODELS LIKELY ARE OVERDOING LOW LEVEL MOISTURE AS THEY OFTEN DO WHEN MODELING SNOWPACK MELTING. REMOVED ANY MENTION OF FREEZING RAIN FOR SAT NIGHT-MON SINCE SFC TEMPS WILL BE TOO WARM FOR FREEZING RAIN IF THE RAIN/CLOUDS ARE AS THICK AS MODELS SUGGEST...AND IF THERE IS LESS LOW LEVEL MOISTURE TEMPS WILL BE COLDER BUT PRECIPITATION PROBABLY WILL NOT OCCUR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1233 PM EST TUE DEC 9 2014 A DIFFICULT LO CLD FCST IS ON TAP FOR THE TAF SITES. LINGERING LLVL MSTR IN UPSLOPE NNE FLOW OFF LK SUP AND UNDER LOWERING SUBSIDENCE INVRN ASSOCIATED WITH BLDG UPR RDG IS CAUSING THE LO CLDS OBSVD TODAY. ALTHOUGH SOME NEAR SFC DRYING WL CAUSE THE CIGS TO RUN GENERALLY IN THE MVFR RANGE...THE LO CLDS SHOULD PERSIST THRU THIS EVNG AT ALL 3 SITES. THE BEST CHC FOR SOME CLRG AND A RETURN TO VFR WX WL BE AT SAW AND IWD LATER TNGT AS THE LLVL FLOW VEERS SLOWLY TO A MORE ESE DIRECTION THAT WL DOWNSLOPE INTO IWD AND LIMIT MOISTENING OFF LK SUP INTO SAW. A MORE UPSLOPE WIND COMPONENT AND SOME MOISTENING OFF LK SUP AT CMX WL LIKELY CAUSE THE MVFR CIGS TO LINGER THERE THRU THE ENTIRE FCST PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 512 AM EST TUE DEC 9 2014 BEHIND A LOW PRES TROF...N TO NW WINDS RAMPED UP TO 20-30KT OVERNIGHT WITH A FEW GALE FORCE GUSTS NOTED OVER CNTRL LAKE SUPERIOR. AS HIGH PRES RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY APPROACHES TODAY...WINDS WILL DIMINISH FROM W TO E TO UNDER 20KT BY EVENING. WITH THE HIGH PRES RIDGE THEN SETTLING OVER THE UPPER LAKES TONIGHT THRU WED...WINDS WILL DROP OFF TO UNDER 15KT. WINDS WILL INCREASE SLIGHTLY THU AND FRI...BUT WILL REMAIN UNDER 20KT. THESE LIGHTER WINDS MAY LINGER ON INTO SAT AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1235 PM EST TUE DEC 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 512 AM EST TUE DEC 9 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF EXTENDING FROM HUDSON BAY S THRU THE OHIO VALLEY. WITH TROF AXIS NOW E OF UPPER MI... HEIGHTS ARE BEGINNING TO RISE AS BROAD RIDGE OVER WRN NAMERICA EXPANDS EASTWARD. AT THE SFC...TROF IS ALSO NOW S AND E OF UPPER MI WITH BRISK N TO NW WINDS USHERING IN SOMEWHAT COLDER AIR INTO THE AREA...MOST NOTICEABLE BLO 850MB. WITH ABUNDANT LOW-LEVEL MOISTURE PER UPSTREAM 00Z KINL/CWPL SOUNDINGS...LOW CLOUDS ARE WIDESPREAD OVER THE UPPER LAKES WITH CLEARING ONLY NOTED OVER PORTIONS OF NRN AND WRN LAKE SUPERIOR IN THE DOWNSLOPE AREAS OFF ONTARIO AND MN NSHORE. TEMPS IN THE SHALLOW MOIST LAYER HAVE BEEN FALLING...BUT APPARENTLY AREN`T COLD ENOUGH YET TO ENSURE COMPLETE ICE NUCLEATION AS -SN HAS BEEN MIXED AT TIMES WITH -FZDZ DURING THE NIGHT IN THE UPSLOPE FLOW OFF LAKE SUPERIOR. LATEST RUC/NAM FCST SOUNDINGS SHOW TEMPS IN THE MOIST LAYER NEARING -10C...SO ANY LINGERING -FZDZ SHOULD BE ENDING IN THE NEXT FEW HRS. A FEW HRS AGO...ONLY ONE HEAVIER BAND OF SNOW WAS NOTED OFF SCNTRL LAKE SUPERIOR INTO THE MARQUETTE AREA AND ERN MARQUETTE COUNTY. CURRENTLY...RADAR DOES NOT SHOW ANYTHING OTHER THAN VERY LIGHT PCPN STREAMERS. LINGERING -SHSN/FLURRIES WILL WIND DOWN TODAY AS INVERSION FALLS TO 2-3KFT AHEAD OF A 1035-1040MB HIGH PRES RIDGE DRIFTING SE TOWARD THE UPPER LAKES. WITH THE ABUNDANT LOW-LEVEL MOISTURE NOTED OVER THE REGION UNDER INVERSION...OPTED TOWARD A MUCH MORE PESSIMISTIC CLOUD FCST TODAY. CLOUDS WILL BE MOST RELUCTANT TO BREAK IN THE AREAS WHERE N TO NE FLOW IS UPSLOPING. BREAKING OF THE CLOUDS MAY BE MORE LIKELY OVER THE FAR E LATER IN THE DAY AS VEERING WINDS INCREASE DOWNSLOPING OFF ONTARIO. MAY SEE A SIMILAR SITUATION NEAR LAKE SUPERIOR OVER THE FAR W LATE AS DOWNSLOPING BEGINS WITH WINDS VEERING MORE EASTERLY. CLOUDS/SHALLOW CAA WILL KEEP TEMPS FROM RISING MUCH DURING THE DAY. SFC HIGH PRES RIDGE AXIS WILL SETTLE OVER UPPER MI/LAKE SUPERIOR TONIGHT. WHILE FAVORABLE FOR A GOOD RADIATIONAL COOLING NIGHT... THERE IS HUGE BUST POTENTIAL WITH TEMPS DUE TO UNCERTAINTY IN CLOUD COVER. BEST BET FOR CLEARING IS IN TWO AREAS. CLEARING SHOULD EXPAND WESTWARD THRU ERN UPPER MI FROM THE DOWNSLOPING OFF ONTARIO UNDER E TO NE FLOW...AND CLEARING WILL ALSO EXPAND NEAR LAKE SUPERIOR OVER WRN UPPER MI AS WINDS BECOME DOWNSLOPING E TO SE. NCNTRL UPPER MI INTO THE KEWEENAW WILL LIKELY SEE MOST PERSISTENT CLOUD COVER TONIGHT AS WINDS MAINTAIN SOME UPSLOPE COMPONENT ALL NIGHT. FOR NOW...INDICATED MIN TEMPS INTO THE SINGLE DIGITS WHERE AT LEAST SOME CLEARING IS EXPECTED. IF SKIES CLEAR...TRADITIONAL COLD SPOTS WILL FALL TO NEAR OR PERHAPS BLO 0F. IF CLOUDS HOLD...TEENS WILL LIKELY BE THE RULE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 346 AM EST TUE DEC 9 2014 AN UPPER RIDGE WILL BUILD OVER THE CWA THROUGH SAT AS A SFC RIDGE SITS OVER THE CWA BEFORE MOVING SE FRI INTO SAT. THIS WILL KEEP CONDITIONS ON THE QUIET SIDE WITH NO PRECIP EXPECTED THROUGH 00Z SUN. WED NIGHT LOOKS TO BE THE COLDEST NIGHT WITH SINGLE DIGIT ABOVE ZERO LOWS INLAND AS THE RIDGE WILL BE OVERHEAD AND THE SIGNIFICANTLY WARMER AIRMASS IS STILL TO THE W. 850MB TEMPS WILL BE ON THE RISE FROM AOB 0C AT 12Z WED TO AOA 10C BY 00Z SAT...WITH THE WARMER TEMPS STICKING AROUND THROUGH SAT. WARMEST TEMPS EXPECTED ON SAT WITH HIGHS FROM THE UPPER 30S TO LOW 40S. WHILE THERE IS A LOT OF UNCERTAINTY WITH THE TRANSITION INTO A MORE ACTIVE PATTER LATE IN THE WEEKEND...IT DOES LOOK LIKE SOME LIGHT PRECIP IS POSSIBLE SOMETIME SUN INTO MON...AND PTYPE WILL TRANSITION BACK TO SNOW AT LEAST OVER PORTIONS OF THE AREA BY MON. LOTS WILL DEPEND ON THE TRACK/STRENGTH OF UPPER LEVEL ENERGY WHICH MODELS VARY SUBSTANTIALLY FROM RUN TO RUN. STILL NOT BUYING GREATER QPF/LOW LEVEL MOISTURE THAT MODELS SHOW ON SUN/SUN NIGHT AS MODELS LIKELY ARE OVERDOING LOW LEVEL MOISTURE AS THEY OFTEN DO WHEN MODELING SNOWPACK MELTING. REMOVED ANY MENTION OF FREEZING RAIN FOR SAT NIGHT-MON SINCE SFC TEMPS WILL BE TOO WARM FOR FREEZING RAIN IF THE RAIN/CLOUDS ARE AS THICK AS MODELS SUGGEST...AND IF THERE IS LESS LOW LEVEL MOISTURE TEMPS WILL BE COLDER BUT PRECIPITATION PROBABLY WILL NOT OCCUR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1233 PM EST TUE DEC 9 2014 A DIFFICULT LO CLD FCST IS ON TAP FOR THE TAF SITES. LINGERING LLVL MSTR IN UPSLOPE NNE FLOW OFF LK SUP AND UNDER LOWERING SUBSIDENCE INVRN ASSOCIATED WITH BLDG UPR RDG IS CAUSING THE LO CLDS OBSVD TODAY. ALTHOUGH SOME NEAR SFC DRYING WL CAUSE THE CIGS TO RUN GENERALLY IN THE MVFR RANGE...THE LO CLDS SHOULD PERSIST THRU THIS EVNG AT ALL 3 SITES. THE BEST CHC FOR SOME CLRG AND A RETURN TO VFR WX WL BE AT SAW AND IWD LATER TNGT AS THE LLVL FLOW VEERS SLOWLY TO A MORE ESE DIRECTION THAT WL DOWNSLOPE INTO IWD AND LIMIT MOISTENING OFF LK SUP INTO SAW. A MORE UPSLOPE WIND COMPONENT AND SOME MOISTENING OFF LK SUP AT CMX WL LIKELY CAUSE THE MVFR CIGS TO LINGER THERE THRU THE ENTIRE FCST PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 512 AM EST TUE DEC 9 2014 BEHIND A LOW PRES TROF...N TO NW WINDS RAMPED UP TO 20-30KT OVERNIGHT WITH A FEW GALE FORCE GUSTS NOTED OVER CNTRL LAKE SUPERIOR. AS HIGH PRES RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY APPROACHES TODAY...WINDS WILL DIMINISH FROM W TO E TO UNDER 20KT BY EVENING. WITH THE HIGH PRES RIDGE THEN SETTLING OVER THE UPPER LAKES TONIGHT THRU WED...WINDS WILL DROP OFF TO UNDER 15KT. WINDS WILL INCREASE SLIGHTLY THU AND FRI...BUT WILL REMAIN UNDER 20KT. THESE LIGHTER WINDS MAY LINGER ON INTO SAT AS WELL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1040 AM CST TUE DEC 9 2014 .UPDATE...EXPECT SUNNY SKIES ACROSS MUCH OF THE ARKLAMISS TODAY. SOME CLOUDS MAY MOVE INTO NORTHERN ZONES THIS AFTERNOON AS A DRY COLD FRONT MOVES THROUGH. HIGH TEMPS TEMPS THIS AFTERNOON LOOK TO RANGE FROM THE MID 50S NORTH TO THE MID 60S SOUTH. THE CURRENT FORECAST IS IN GOOD SHAPE...WITH ONLY MINOR ADJUSTMENTS TO THE HOURLY TEMPS FOR LATE THIS MORNING. /27/ && .AVIATION...MORNING FOG IS SLOWLY CLEARING AND MOST SITS HAVE RESUMED VFR CONDITIONS. KGLH/KGWO ARE SLOWER TO CLEAR AND THESE WILL HANG ONTO MVFR CONDITIONS TIL ALMOST 17-18Z. VFR CONDITIONS WILL PREVAIL TODAY. A COLD FRONT WILL MOVE THROUGH TODAY AND MAY BRING SOME MVFR RESTRICTIONS IN THE NORTH AFTER 20Z. THIS WILL REINFORCE NORTHERLY WINDS AROUND 5-10KTS. /28/ && .PREV DISCUSSION... /ISSUED 402 AM CST TUE DEC 9 2014/ SHORT TERM...FOCUS OF THIS SHORT TERM CONTINUES TO BE WITH THE REINFORCING SHOT OF COOLER AIR FOR LATER TODAY. FROM THIS...THE MAIN FORECAST ELEMENTS WILL BE ON TEMPS AND CLOUDS. THE NOTICEABLE ARRIVAL OF THE COOLER AIR WILL NOT BE UNTIL LATER IN THE AFTERNOON AND EVENING FOR THE CWA. PRIOR TO THAT...SFC WINDS WILL BE OUT OF THE NW...BUT FULL SUNSHINE AND SOMEWHAT OF A FLAT LOW LEVEL THERMAL AXIS WILL ALLOW FOR A BETTER WARMUP THAN PREV EXPECTED. DUE TO THIS...AREAS SOUTH OF THE HWY 82 CORRIDOR SHOULD PEAK BETWEEN 60-66 DEGREES AND I HAVE USED VALUES THAT WERE ON THE UPPER END OF THE GUID ENVELOP. FOR LOCATIONS ALONG AND NORTH OF HWY 82...THIS IS MORE TRICKY AS THE PROGRESSION OF THE COOLER AIR LOOKS TO ARRIVE HERE IN TIME TO LIMIT WARMING A BIT. A BLEND OF THE HI-RES AND RAP MODELS WERE USED HERE AND HIGHS MAY ONLY REACH 53-58. AS FOR CLOUDS...PREV EXPECTATIONS WERE FOR CLEAR SKIES. HOWEVER...THE LATEST NAM/RAP INDICATE THAT FRONTAL LIFT ALONG WITH STRONG CAA WILL SUPPORT AT LEAST A BKN DECK NEAR AND BEHIND THE FRONT. FOR TONIGHT...THESE LOW CLOUDS SHOULD DISSIPATE DURING THE OVER...BUT THEN BEGIN TO GET REPLACED BY INCREASING/THICKENING HIGH CLOUDS...ESPECIALLY FOR MIDDAY WED AND INTO THE AFTERNOON/EVE. LOWS TONIGHT ARE NOT CLEAR CUT AS THE GFS MOS IS COOLER AND OTHER GUID IS A BIT WARMER. I LIKE A BLEND WITH A LEAN TOWARD THE WARMER GUID DUE TO SFC WINDS STAYING UP OVERNIGHT. SOME FREEZING TEMPS ARE POSSIBLE ACROSS THE N HALF...BUT IF THAT OCCURS IT WILL BE BRIEF. HIGHS WED WILL BE ON THE COOL SIDE AND RANGE FROM THE UPPER 40S N TO MID 50S S. A COMBO OF CAA AND HIGH CLOUDS WILL KEEP TEMPS IN CHECK. IF THE HIGH CLOUDS BECOME THICK ENOUGH...READINGS COULD FALL SHORT OF EXPECTED VALUES. WED NIGHT WILL BE THE COLDEST NIGHT THIS WEEK...BUT I WILL NOT GET TOO AGGRESSIVE AND MUCH OF THE COOLING WILL DEPEND ON IF THE HIGH CLOUDS EXIT OR THIN ENOUGH. ALL THE AVAILABLE GUID IS CLOSE WITH UPPER 20S N TO LOWER 30S S AS THE RANGE. THU WILL BE A TAD WARMER AS SOME MODIFICATION OCCURS THANKS TO A BIT MORE SUN WITH A MIX OF CLOUDS AS WELL. /CME/ LONG TERM...THURSDAY NIGHT THROUGH NEXT MONDAY... GLOBAL MODELS ARE REMARKABLY CONSISTENT CONSIDERING THE AMPLIFIED PATTERN THAT IS FORECAST TO EVOLVE. A DEEP TROUGH ALONG THE EAST COAST AT THE START OF THE PERIOD WILL SHIFT EAST AND ALLOW A RIDGE TO MOVE ACROSS THE MS VALLEY THROUGH THE WEEKEND. FRIDAY WILL BE SEASONABLY COOL...BUT THEN EXPECT TEMPERATURES TO WARM SOME SATURDAY AND SUNDAY TO SLIGHTLY ABOVE CLIMATIC NORMALS AS SURFACE PRESSURES FALL AND RETURN FLOW BEGINS TO DEVELOP. EMPHASIS WILL THEN SHIFT TO THE SOUTHERN STREAM AND A SIGNIFICANT SHORTWAVE TROUGH EXPECTED TO MOVE INTO THE LOWER MS VALLEY REGION EARLY NEXT WEEK. MODEL DIFFERENCES START TO DEVELOP WITH HANDLING OF THIS TROUGH AND HOW MUCH PHASING TAKES PLACE - THE ECWMF IS MORE DISTINCT/SEPARATE AND THEREFORE A LITTLE SLOWER AND MORE ROBUST WITH CONVECTIVE PRECIPITATION IN THE ARKLAMISS WHILE THE GFS/GEFS INDICATE MORE ENERGY IN THE NORTHERN STREAM. THE AMPLIFIED PATTERN MAY SUPPORT MORE OF A CLOSED OFF SOLUTION SUCH PER THE ECWMF...BUT INSTABILITY WILL BE VERY LIMITED AS THE PRECEDING HIGH DOES NOT ALLOW FOR MUCH OF A WINDOW FOR SIGNIFICANT WARM ADVECTION/MOISTURE TRANSPORT. /EC/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 63 33 51 33 / 0 0 0 0 MERIDIAN 63 32 51 30 / 0 0 0 0 VICKSBURG 64 33 51 32 / 0 0 0 0 HATTIESBURG 66 35 55 33 / 0 0 0 0 NATCHEZ 64 35 52 34 / 0 0 0 0 GREENVILLE 56 32 48 31 / 0 0 0 0 GREENWOOD 56 31 49 30 / 0 0 0 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1112 AM CST Tue Dec 9 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 315 AM CST Tue Dec 9 2014 Vort max which dropped across the region overnight is now working its way into the TN valley, with associated cold front currently dropping into far s counties of our CWA. Early morning 11-3.9 low cloud imagery indicates an extensive area of ST and SC in the wake of the front, with this low cloud deck extending into the upper Mississippi Valley and upper Great Lakes with only a few minor breaks noted. While can`t rule out a bit of sunshine, believe clouds will dominate much of the region today due to the extensive low level moisture trapped beneath a fairly stout inversion, as suggested by 925mb RH progs from both the RUC and NAM. Today will certainly be cooler than yesterday, and I`ve attempted to try to limit diurnal swing as clouds should definitely inhibit a big daytime temp swing. However, if a solid cloud deck holds throughout the day going max temps may still be a bit too warm. Truett .LONG TERM: (Tonight through Monday) Issued at 315 AM CST Tue Dec 9 2014 (Tonight-Thursday) Chilly and tranquil weather should continue during this time frame, and the primary forecast concern is how short-term low cloud trends will evolve heading into midweek. Given forecast inversion and north-northeast low level flow forecast across the area as surface ridge works into the upper Mississippi Valley, believe low clouds will hold over the region tonight and will likely have a tendency to hang tough through Wednesday, with some additional mid level cloudiness spilling into the area as strong but moisture-starved shortwave zips down the back side of the large upper level low winding up over the east coast. Temperatures should moderate a bit by Thursday with a slightly warmer airmass and a bit more sunshine. (Friday-Monday) Medium range solutions take eastern U.S. low up the eastern seaboard heading into the end of the week, allowing upper level ridge to work into the central CONUS. Resultant warming of the AMS over the mid-Mississippi Valley should provide a strong rebound in temps across the FA, with highs in the 50s by the end of the week. UA pattern over the CONUS becomes even more progressive by late in the period, allowing aforementioned ridge to push east and deep UA trof over the western U.S. to sweep into the Plains. This could mean some precip in our CWA by Sunday, with better chances by the start of the new work week. This system should be a rain-maker for our area due to the relatively mild AMS. Truett && .AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon) Issued at 1053 AM CST Tue Dec 9 2014 Although there may be a few thin spots or holes in the shallow low level stratus cloud deck, it appears that the low level cloud ceiling will continue through the forecast period. The cloud ceiling will rise to around 3000 feet at some of the taf sites this afternoon, but then likely drop down to 1000-1500 feet late tonight with patchy light fog possible as the n-nwly surface wind becomes light nely tonight. Specifics for KSTL: Cloud ceiling height should hover around 2500-3000 feet this afternoon, then likely drop to around 1000-1500 feet late tonight/early Wednesday morning. The ceiling will graduallly rise to near 3000 feet again Wednesday afternoon. N-nwly surface wind will veer around to a nely direction and become light this evening as the surface ridge extending from MN southwest into central KS shfits slowly eastward. GKS && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1221 PM CST TUE DEC 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CST TUE DEC 9 2014 SYNOPTIC ANALYSIS OVERNIGHT INDICATES THE UPPER LEVEL TROUGH CONTINUING TO SHIFT ACROSS THE OHIO RIVER VALLEY WHILE AN UPPER LEVEL RIDGE HAS BEGUN TO BUILD ACROSS THE ROCKY MOUNTAINS. ALOFT...A 100+ KT JET CAN BE SEEN DIVING SOUTH ACROSS IOWA AND WESTERN MISSOURI AROUND THE BASE OF THE TROUGH. IN THE MID LEVELS...HEIGHT RISES SUGGEST THE BUILDING OF THE MID LEVEL RIDGE ACROSS THE MIDWEST...AND SOME MINIMAL MID LEVEL MOISTURE PRESENT ACROSS THE PLAINS. AT THE SURFACE...LOW PRESSURE CAN BE SEEN ACROSS THE GREAT LAKES WHILE A LARGE AREA OF HIGH PRESSURE BEGINS TO SPREAD FROM MANITOBA STRETCHING SOUTH INTO NEBRASKA. LATEST SATELLITE IMAGERY SHOWS A LARGE AREA OF STRATUS CIRCULATING UNDER THE UPPER LEVEL LOW...WITH STRATUS BANDS STRETCHING INTO PORTIONS OF CENTRAL NEBRASKA. UNDER THESE BANDS...METAR SITES HAVE INDICATED CEILING HEIGHTS NEAR 1500 FT AND VISIBILITIES AS LOW AS 1/4 MILE AT VALENTINE. FOR THE VERY NEAR SHORT TERM...THESE STRATUS BANDS WILL BE OF CONCERN. SHORT TERM MODELS SUCH AS THE RAP...SREF...AND HRRR ALL SUGGEST THAT REDUCED VISIBILITIES WILL BE VERY CLOSE TO OUR WESTERN BORDER...WHILE THE GFS REMAINS DRY. AT THIS TIME...CONTINUED WITH AREAS OF FOG IN THE FORECAST...BUT WILL CONTINUE TO MONITOR IN CASE A DENSE FOG ADVISORY IS NEEDED. AS SUCH...AS THE HIGH PRESSURE/RIDGE AXIS SWINGS THROUGH THE PLAINS...EXPECT WINDS TO SWITCH TO SOUTHERLY AND HELP CLEAR OUT ANY FOG THAT DOES DEVELOP BY MID TO LATE MORNING. THE MAIN FOCUS OF THE REST OF THE SHORT TERM PERIOD WILL CENTER ON THE POSSIBILITY FOR FREEZING DRIZZLE AND FOG OVERNIGHT AND INTO WEDNESDAY MORNING. AN UPPER LEVEL SHORT WAVE DISTURBANCE WILL DEVELOP ACROSS THE NORTHERN ROCKIES AND SWING THROUGH THE CENTRAL PLAINS OVERNIGHT. AT THE SURFACE...LIGHT SOUTH WINDS WILL SURGE LOW LEVEL MOISTURE NORTHWARD ACROSS MUCH OF THE AREA. THIS COMBINED WITH LIFT FROM THE UPPER LEVEL DISTURBANCE SHOULD PROMOTE FOG DEVELOPMENT. HOWEVER...SOUNDINGS INDICATE VERY DRY MID LEVELS AND BOTH THE NAM AND GFS SOLUTIONS SUGGESTING HIGHER BULK SHEAR VALUES NEAR 10 KTS...ESPECIALLY ACROSS NORTH CENTRAL KANSAS AND THE STATE LINE. THEREFORE...IT REMAINS A STRONG POSSIBILITY OF FREEZING DRIZZLE ACROSS NORTH CENTRAL KANSAS AND SOUTHERN NEBRASKA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 335 AM CST TUE DEC 9 2014 THE MODELS CONTINUE TO HAVE THE MOISTURE ACROSS THE AREA DURING THE DAY WEDNESDAY AND EVEN INTO WEDNESDAY NIGHT. EXPECT THE FOG AND FREEZING DRIZZLE FROM TUESDAY NIGHT TO CONTINUE INTO WEDNESDAY MORNING. AS TEMPERATURES WARM DURING THE MORNING THE FREEZING DRIZZLE SHOULD BECOME DRIZZLE. THE PRECIPITATION SHOULD REMAIN MAINLY IN THE SOUTHEAST PART OF THE FORECAST AREA. WILL CONTINUE WITH DRIZZLE IN THE SOUTHEAST DURING THE AFTERNOON. THE ONLY MODEL THAT MOVES THE MOISTURE OFF TO THE EAST IS THE GFS...SO WILL KEEP THE DRIZZLE INTO THE NIGHT TIME HOURS. IT SHOULD BE IN THE SOUTHEAST AND SHOULD GRADUALLY END FROM WEST TO EAST DURING THE NIGHT. THURSDAY AND BEYOND THE MODELS HAVE SEVERAL DIFFERENCES IN TIMING AND STRENGTH OF THE SYSTEMS AND EVEN SOME RUN TO RUN INCONSISTENCIES. THERE IS AN UPPER LEVEL RIDGE THAT WILL MOVE THROUGH THE AREA THURSDAY AND FRIDAY. EXPECT THE TEMPERATURES TO WARM UP AS THERE WILL BE PARTLY CLOUDY SKIES AND WARM ADVECTION. AN UPPER LEVEL SYSTEM IN THE ROCKIES WITH A DEVELOPING SURFACE LOW ON THE HIGH PLAINS WILL BRING MOISTURE BACK TO THE AREA ON SATURDAY. THERE WILL BE WARM ADVECTION AND TEMPERATURES WILL BE WARM ON SATURDAY. THE SURFACE LOW AND COLD FRONT WILL MOVE THROUGH THE FORECAST AREA SATURDAY NIGHT. THE COOLER AIR STARTS TO MOVE INTO THE AREA ON SUNDAY AND TEMPERATURES WILL BE A LITTLE COOLER THAN SATURDAY. THE QUESTION BECOMES PRECIPITATION CHANCES. FORECAST SOUNDINGS SHOW THAT THERE WILL BE A DRY LAYER AND HAVE KEPT PRECIPITATION IN THE SOUTHEAST...BUT THAT IS EVEN A LITTLE QUESTIONABLE. BY SATURDAY NIGHT THE MID LEVELS MOISTEN UP SOME AND THERE WILL BE A FEW MORE CLOUDS WITH MAYBE SOME RAIN IN THE EAST. SUNDAY AND SUNDAY NIGHT LOOK LIKE BETTER CHANCES FOR SOME PRECIPITATION. THIS IS THE FIRST RUN WHERE THE GFS AND THE ECMWF ARE A LITTLE MORE CONSISTENT WITH THE UPPER LOW IN THE CENTRAL TO SOUTHERN PLAINS. THE GFS IS FASTER THAN THE ECMWF. WILL KEEP PRECIPITATION CHANCES FOR SUNDAY AND SUNDAY NIGHT...BRINGING UP THE QUESTION OF PRECIPITATION TYPE. SUNDAY THE TEMPERATURES SHOULD BE WARM ENOUGH THAT EXPECT RAIN BUT TEMPERATURES AT 850MB START TO COOL LATE IN THE AFTERNOON. DURING THE NIGHT THE TEMPERATURES CONTINUE TO COOL AND THE RAIN SHOULD MIX WITH AND MAYBE CHANGE TO SNOW DURING THE NIGHT. THE UPPER LOW SHOULD MOVE TO THE EAST AND EXPECT DRY AND COOL CONDITIONS FOR MONDAY. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1145 AM CST TUE DEC 9 2014 THE PRIMARY AVIATION CONCERN WILL CENTER AROUND THE POSSIBILITY OF LOW CLOUDS AND FOG MOVING IN LATE TONIGHT...PRIMARILY AROUND DAWN. THERE IS A VERY SLIGHT THREAT OF LIGHT DRIZZLE OR FREEZING DRIZZLE. HOWEVER...THE CHANCE OF ANY PRECIPITATION IS TOO LOW TO INCLUDE IN THE TAF AT THIS POINT IN TIME. IFR VISIBILITY AND CEILINGS WILL ALSO BE POSSIBLE WEDNESDAY MORNING FROM AROUND DAWN THROUGHOUT THE MORNING...BUT DIFFICULT TO DETERMINE HOW LOW THE CEILINGS AND VISIBILITY WILL GET THIS FAR OUT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...SALTZMAN LONG TERM...JCB AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1123 AM CST TUE DEC 9 2014 .SYNOPSIS... ISSUED AT 358 AM CST TUE DEC 9 2014 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A DECENT UPPER LEVEL DISTURBANCE OVER NRN ILLINOIS WITH A TROUGH EXTENDING SWD TO THE FLORIDA PANHANDLE. FURTHER WEST...A BROAD RIDGE EXTENDED FROM THE INTERMOUNTAIN WEST NORTH INTO THE YUKON OF CANADA. WITHIN THIS RIDGE...A DISTURBANCE WAS NOTED OVER WESTERN MONTANA. CURRENT WV IMAGERY AS OF 2 AM CST HAS THIS FEATURE NOW OVER EASTERN PORTIONS OF MT. AT THE SURFACE...AN ELONGATED AREA OF HIGH PRESSURE EXTENDED ACROSS THE EASTERN DAKOTAS INTO EASTERN NEBRASKA. FURTHER WEST...A TROUGH OF LOW PRESSURE WAS PRESENT OVER EASTERN WYOMING INTO NORTHERN COLORADO. AN AREA OF STRATUS AND FOG HAS DEVELOPED ON THE WESTERN PERIPHERY OF THE HIGH OVERNIGHT...AND THIS AREA OF CLOUDS AND FOG EXTENDED FROM NORTH CENTRAL NEBRASKA INTO CENTRAL AND PORTIONS OF SWRN NEBRASKA. THE FOG WAS PRIMARILY ALONG THE WESTERN EDGE OF THE STRATUS/LOW CLOUDS AND ROUGHLY EXTENDED FROM VALENTINE TO AINSWORTH...SWD TO THEDFORD...NORTH PLATTE AND BROKEN BOW. FURTHER WEST...SOME HIGH CLOUDS WERE MOVING INTO THE NEBRASKA PANHANDLE AND FAR WESTERN PORTIONS OF THE FORECAST AREA ATTM. UNDER MOSTLY CLOUDY SKIES...TEMPERATURES AS OF 3 AM CST...RANGED FROM 15 AT NORTH PLATTE TO 25 AT BROKEN BOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CST TUE DEC 9 2014 TODAY AND TONIGHT...THE FORECAST CHALLENGES OVER THE NEXT 24 HOURS...ARE TEMPERATURES TODAY...AS WELL AS FOG POTENTIAL THIS MORNING...AS WELL AS TONIGHT. FOR TODAY...AS MENTIONED ABOVE...FOG HAS DEVELOPED ALONG THE HIGHWAY 83 CORRIDOR...AS WELL AS ALONG A LINE FROM AINSWORTH TO BROKEN BOW. ATTM...THE LATEST HI RES RUC SOLN HAS THIS AREA OF FOG EXPANDING SLIGHTLY TO THE SOUTHWEST TOWARD DAYBREAK. ONE WILDCARD IN THE DEGREE OF WESTWARD DEVELOPMENT OF FOG...IS THE POTENTIAL IMPACT OF HIGH LEVEL CLOUDINESS MOVING IN FROM THE WEST. ATTM...FOG VISBYS HAVE BEEN GENERALLY IN THE 1 TO 5 MILE RANGE...SO WILL KEEP FOG MENTION AS PATCHY THIS MORNING. BASED ON THE HRRR SOLN...FOG SHOULD BEGIN TO DISSIPATE DURING THE MID TO LATE MORNING TIME FRAME...AND HAVE EXTENDED THIS MENTION OF FOG INTO THE LATE MORNING HOURS GIVEN THIS MODEL TREND. HIGH PRESSURE WILL BEGIN TO TRACK EAST LATER TODAY INCREASING SRLY WINDS DURING THE AFTERNOON HOURS. FOR LOCATIONS GENERALLY WEST OF HIGHWAY 61...THE WIND DIRECTION WILL TAKE ON A WESTERLY COMPONENT...RESULTING IN SOME LIMITED DOWNSLOPE AND WARMER HIGHS IN THE LOWER 50S. FURTHER EAST...THE COMBINATION OF CLOUDS...SOUTHERLY AND SOUTHEASTERLY WINDS ON THE BACK SIDE OF THE EXITING HIGH...WILL LIMIT HIGHS IN THE UPPER 30S IN THE FAR NORTHEAST...TO THE 40S ALONG THE HIGHWAY 83 CORRIDOR. THE LATEST MAV GUIDANCE HAS TRENDED COLDER FOR HIGHS OVER THE PAST 3 RUNS...AND HAS COME INTO BETTER AGREEMENT WITH THE COLDER MET GUIDANCE. WITH THIS IN MIND...TRENDED HIGHS TDY SOME 2 TO 4 DEGREES COLDER THAN THE INHERITED FCST. FOR TONIGHT...LIGHT SRLY WINDS WILL CONTINUE...PARTICULARLY IN THE EASTERN CWA. THE LATEST NAM SOLN IS INDICATING NEAR SATURATION IN THE BOUNDARY LAYER OVERNIGHT TONIGHT...ROUGHLY EAST OF A LINE FROM CURTIS...TO ONEILL. INHERITED FCST HAD A MENTION OF PATCHY FOG OVERNIGHT IN THESE AREAS AND IT WILL BE CONTINUED WITH THE CURRENT FCST PACKAGE. OVERNIGHT LOWS WILL BE IN THE LOWER 20S...WITH SOME UPPER TEENS IN THE PLATTE RIVER VALLEY GIVEN THE EXPECTED LIGHT WINDS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 358 AM CST TUE DEC 9 2014 12Z WEDNESDAY AND BEYOND...MODELS REMAIN IN GOOD AGREEMENT THAT AMPLIFIED UPPER RIDGING OVER THE CENTRAL CONUS WILL EVENTUALLY BREAK DOWN/FORCED EAST AS A LONG WAVE TROUGH DIGS INTO THE WESTERN STATES AND EVENTUALLY THE PLAINS. TEMPERATURES UNDER THE RIDGE WILL REMAIN ABOVE AVERAGE...AND SHOULD WARM BY SEVERAL DEGREES EACH DAY. HIGHS BY FRIDAY ARE ANTICIPATED TO REACH INTO THE 50S TO LOWER 60S FOR MOST AREAS...POSSIBLY WARMER IF GREATER MIXING OCCURS. SOUTHERLY WINDS WILL HELP INCREASE LOWER LEVEL MOISTURE WHICH COULD PROVIDE FOR PATCHY FOG EACH MORNING...WEDNESDAY THROUGH SATURDAY. THE DETERMINISTIC SOLUTIONS GENERATE LIGHT DZ/QPF ACROSS PORTIONS OF OUR EAST THURSDAY...FRIDAY...AND SATURDAY...BUT THE MOISTURE PROFILES ONLY FAVOR STRATUS AND/OR FOG AS THE DEPTH OF THE RETURN IS RATHER SHALLOW. CONCERNING THIS WEEKEND AND A POTENTIAL SYSTEM...WHAT A DIFFERENCE A DAY MAKES. IN 24 HOURS THE GFS SOLUTION HAS TRENDED NORTH WITH THE TRACK OF THIS WEEKENDS CLOSED H5 LOW BY HUNDREDS OF MILES. THE MODEL GENERATED TRACK OF THE LOW YESTERDAY FAVORED THE BIG BEND OF TEXAS ON SUNDAY...THEREAFTER TRACKING THE LOW OVER HEART OF TEXAS THROUGH EARLY NEXT WEEK. TONIGHT...THE GFS IS FAVORING A SOLUTION WHICH CLOSES OFF A LOW OVER NORTHERN NEW MEXICO...THEN TRACKING THE LOW ACROSS THE PANHANDLES OF TEXAS AND OKLAHOMA...AND EVENTUALLY TOWARD THE MID-MISSOURI VALLEY. IT SHOULD BE NOTED THAT THE MODEL INDICATES THE MEAN TROUGH TAKING A NEGATIVE TILT AS IT EMERGES ON THE PLAINS. COMPLICATING MATTERS...THE EUROPEAN CAMP AND NUMEROUS GFS ENSEMBLES SUPPORT A SIMILAR TRACK INTO THE CENTRAL PLAINS /AT LEAST INITIALLY/. SO FOR THE FIRST SUITE OF RUNS PROGGING THIS SYSTEM...MODEL TO MODEL CONSISTENCY IS SHOWING SOME COHERENCE...BUT RUN TO RUN CONSISTENCY IS SEVERELY LACKING. CONFIDENCE IN ANY ONE PARTICULAR SOLUTION IS LOW...ESPECIALLY SINCE ALL LONG TERM GUIDANCE GENERATES CONVECTION ACROSS THE SOUTHERN PLAINS AND TEXAS ON SUNDAY. THE GFS SEEMS TO BE KEYING ON THE CONVECTIVE POTENTIAL...GENERATING AN AREA OF PV DESTRUCTION OVER OUR SOUTH...AND SEVERELY LIMITING THE QPF POTENTIAL ACROSS MUCH THE CWA. THE GFS HOWEVER DOES EVENTUALLY GENERATE WRAP AROUND QPF SUNDAY AFTERNOON/EVENING ACROSS OUR SOUTH AND EAST. THE WRAP AROUND IS IN QUESTION AS THE CONVECTION /PROJECTED TO BE OVER EASTERN KANSAS/ WOULD ALLOW FOR AN ASSUMED GREATER EASTWARD WOBBLE OF THE H7 LOW. SO INSTEAD OF THE MODEL PROJECTED H7 LOW OVER NORTH CENTRAL KANSAS...THE MORE LIKELY LOCATION WOULD BE EASTERN OR SOUTHEASTERN KANSAS. THE WRAP AROUND WOULD THUS BE SHUNTED SOUTHEAST AS WELL. THE ECMWF IS CONCERNING...GENERATING SIGNIFICANT SNOW ACROSS OUR SOUTHERN TIER ON SUNDAY...BUT AGAIN...THE CONVECTION THAT THE MODEL IS GENERATING PUTS ANY OF THE QPF ACROSS OUR CWA SEVERELY IN QUESTION. THE CR-INT PROCEDURE REMAINS PESSIMISTIC IN THE QPF DEPARTMENT FOR SUNDAY AND BEYOND...WHICH IS FAVORED AT THIS POINT...NO CHANGES WERE MADE TO THE BLENDED FORECAST. BUT...LAST NIGHT MY FORECAST STATED THE POTENTIAL WEEKEND STORM WAS LOOKING MORE LIKE A "DUD" FOR THE CWA...AT THIS TIME I WISH TO RETRACT THOSE WORDS AND STATE THAT THIS SYSTEM IS CERTAINLY WORTH WATCHING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1110 AM CST TUE DEC 9 2014 CURRENTLY PATCHY FOG AND LOW STRATUS IS OCCURRING TO THE EAST OF THE HWY 83 CORRIDOR...THIS WILL NOT AFFECT THE KVTN OR KLBF SITES AS THE COVERAGE SHOULD STAY OFF TO THE EAST AND CONTINUE TO DISSIPATE DURING THE AFTERNOON HOURS. VFR CONDITIONS ARE EXPECTED AS BROKEN HIGH CLOUDS WILL PERSIST THROUGH MUCH OF THE DAY. WINDS WILL SHIFT OVERNIGHT FROM THE SOUTH TO THE SOUTHWEST AND SKIES WILL BE MOSTLY CLEAR THROUGH THE OVERNIGHT INTO TOMORROW. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...JACOBS AVIATION...GOMEZ
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
335 PM EST TUE DEC 9 2014 .SYNOPSIS... A VERY SLOWLY MOVING NOR EASTER WILL HAVE A LARGE IMPACT ON THE REGION. MIXED PRECIPITATION WILL BEGIN TO MIX WITH AND CHANGE TO SNOW TONIGHT. LIGHT SNOW ACCUMULATIONS ARE EXPECTED AREAWIDE THROUGH THURSDAY MORNING...AS WELL AS SOME LIGHT ICE ACCUMULATIONS MAINLY AT HIGHER ELEVATIONS. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 1 PM UPDATE... SFC LOPRES HAS DROPPED DOWN TO NR 1000MB AS IT SPINS OFF THE JERSEY SHORE. MODERATE TO HVY PCPN IS ONGOING ACRS ERN HALF OF CWA AS EXPECTED BUT THERMAL PROFILES ARE TOO WARM FOR SNOW. SOME HIGHER ELEVATION SITES ARE STILL RIGHT AT OR BLO FRZG AS OF 17Z WITH -FZRA FALLING AT THESE LOCATIONS AND HEARING ABOUT NUMEROUS MOTOR VEHICLE ACCIDENTS. PCPN HAS ESSENTIALLY HIT A BRICK WALL AT THE I-81 CORRIDOR AND NOT EXPECTING THIS TO MV MUCH FURTHER EAST THAN WHERE IT CURRENTLY IS NOW UNTIL AFT 00Z. DEFORMATION BAND THAT THE MODELS WERE INSISTENT WUD ROTATE WEST THRU THE EVNG HRS IS NOW LOOKING TO BE A FRACTURED BAND OF MIXED PCPN. H9 TEMPS PER LATEST RUC MODEL INDICATING BLYR TEMPS RMNG ISOTHERMAL THRU 21Z THIS AFTN AND VRY SLOWLY DROPPING BYND THIS TIME. EXPECT A MIXED BAG THRU BULK OF THE OVRNGT FOR SXNS EAST OF I-81 WITH CLD AIR BEING PULLED IN FM THE WEST. ANOTHER WV FCST TO MV THRU NRN ZONES AFT 06Z TONIGHT AND WITH MOISTURE FM LK ADDED IN EXPECT SVRL INCHES OF SNOW TO FALL ACRS THE FINGER LKS BY 12Z. STORM TOTAL SNOWFALL THRU THE OVRNGT IS NOW LOOKING TO BE MEAGER WITH A GNRL INCH OR TWO ACRS THE BULK OF THE AREA AND POSSIBLY 2-4 INCHES IN HIGHER ELEVATIONS OF SUSQUEHANNA REGION. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... 315 PM UPDATE... MOISTURE WL CONTINUE TO WRAP-ARND THE NOR`EASTER THRU THE SHORT TERM. DEFORMATION BAND FINALLY GETTING ITS ACT TOGETHER CURRENTLY AND WL ROTATE INTO THE FINGER LKS BY MORNING. ADDED MOISTURE OFF OF THE LKS WL LKLY BRING 3-6 INCHES OF SNOW ACRS FINGER LKS AND SUSQUEHANNA REGION DRG THE DAY WED THO AMNTS MAY BE SLIGHTLY HIGHER, THUS HV OPTED TO KEEP WARNINGS GOING FOR CNTRL NY. SYSTEM WL BCM VERTICALLY STACKED DRG THE DAY TOMORROW AND WITH NW FLOW MVG DOWN ACRS THE LKS EXPECT SNOW TO CONTINUE ON WEDNESDAY. ONLY QUESTION WL BE IS IF DRY SLOT WL MV IN FM THE EAST AND DENDRITE ZONE WL LOSE MOISTURE DRG THE AFTN HRS BUT WL ALLOW LATER SHIFTS DECIDE ON DROPPING HEADLINES EARLY. && .LONG TERM /THURSDAY THROUGH TUESDAY/... PERIOD BEGINS WITH PERSISTENT UPPER LOW WOBBLING AROUND OVER EASTERN NEW YORK AND SOUTHERN NEW ENGLAND. THIS WILL PUT OUR AREA IN A FAVORABLE LOCATION FOR PERIODS OF SNOW WRAPPING AROUND THE UPPER LOW. HAVE GONE WITH LIKELY POPS FOR THURSDAY ACROSS NY AND FAR NORTHERN PA WITH HIGH CHANCE DONE AROUND I-80 FOR SNOW SHOWERS. 850 MB TEMPERATURES ARE FORECAST TO BE AROUND -6 TO -8 WITH WARM ADVECTION FROM THE NORTH-NORTHEAST. THIS SHOULD BE COLD ENOUGH FOR SOME LAKE ENHANCEMENT IN THE NNW FLOW. THIS PATTERN IS USUALLY FAVORABLE FOR WIDESPREAD LIGHT TO MODERATE SNOWFALL ACROSS OUR AREA ESPECIALLY ACROSS NY STATE WITH MANY AREAS PROBABLY STILL GETTING ANOTHER COUPLE OF INCHES OF SNOW. UPPER LOW REMAINS OVER NEW ENGLAND INTO SATURDAY. AS A RESULT SCATTERED SNOW SHWOERS REMAIN IN THE FORECAST INTO SATURDAY ALONG WITH BELOW NORMAL TEMPERATURES. COMPLETELY DRY WEATHER SHOULD RETURN BY SUNDAY AND MONDAY ALONG WITH MODERATING TEMPERATURES. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... RAIN WITH POCKETS OF FREEZING RAIN WILL CHANGE TO SNOW AND SNOW SHOWERS TONIGHT AS LOW PRESSURE REMAINS NEARLY STATIONARY ALONG THE EAST COAST. SNOW SHOWERS WILL PERSIST THROUGH WEDNESDAY. CIGS WILL BE MOSTLY MVFR WITH AREAS OF IFR ESPECIALLY ON HILL TOP AIRPORTS SUCH AS ITH AND BGM. VSBYS WILL FALL TO IFR AS PRECIPITATION CHANGES TO SNOW AND SNOW SHOWERS TONIGHT. WINDS WILL BE LIGHT AND VARIABLE BECOMING NORTH AT 5 TO 10 KTS THIS AFTERNOON THEN NORTHWEST AT 10 TO 15 KTS TONIGHT AND WEDNESDAY WITH GUSTS OF 20 TO 25 KTS WEDNESDAY. OUTLOOK... TUE NGT THROUGH WED...MVFR/IFR IN SNOW OR BLSN. NEAR AIRPORT MINS AT TIMES IN BANDS OF HEAVY SNOW TUE NGT-EARLY WED. THU/FRI...RESTRICTIONS POSSIBLE IN SHSN. BETTER CHC IN NY. SAT...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR PAZ039-040. WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR PAZ038-043- 044-047-048-072. NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ009- 015>018-023-025-036-037-044>046-055>057. WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR NYZ022-024- 062. && $$ SYNOPSIS...PVF NEAR TERM...PVF SHORT TERM...PVF LONG TERM...DJP/MSE AVIATION...DJP/MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
316 PM EST TUE DEC 9 2014 .SYNOPSIS... A VERY SLOWLY MOVING NOR EASTER WILL HAVE A LARGE IMPACT ON THE REGION. MIXED PRECIPITATION WILL BEGIN TO MIX WITH AND CHANGE TO SNOW TONIGHT. LIGHT SNOW ACCUMULATIONS ARE EXPECTED AREAWIDE THROUGH THURSDAY MORNING...AS WELL AS SOME LIGHT ICE ACCUMULATIONS MAINLY AT HIGHER ELEVATIONS. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 1 PM UPDATE... SFC LOPRES HAS DROPPED DOWN TO NR 1000MB AS IT SPINS OFF THE JERSEY SHORE. MODERATE TO HVY PCPN IS ONGOING ACRS ERN HALF OF CWA AS EXPECTED BUT THERMAL PROFILES ARE TOO WARM FOR SNOW. SOME HIGHER ELEVATION SITES ARE STILL RIGHT AT OR BLO FRZG AS OF 17Z WITH -FZRA FALLING AT THESE LOCATIONS AND HEARING ABOUT NUMEROUS MOTOR VEHICLE ACCIDENTS. PCPN HAS ESSENTIALLY HIT A BRICK WALL AT THE I-81 CORRIDOR AND NOT EXPECTING THIS TO MV MUCH FURTHER EAST THAN WHERE IT CURRENTLY IS NOW UNTIL AFT 00Z. DEFORMATION BAND THAT THE MODELS WERE INSISTENT WUD ROTATE WEST THRU THE EVNG HRS IS NOW LOOKING TO BE A FRACTURED BAND OF MIXED PCPN. H9 TEMPS PER LATEST RUC MODEL INDICATING BLYR TEMPS RMNG ISOTHERMAL THRU 21Z THIS AFTN AND VRY SLOWLY DROPPING BYND THIS TIME. EXPECT A MIXED BAG THRU BULK OF THE OVRNGT FOR SXNS EAST OF I-81 WITH CLD AIR BEING PULLED IN FM THE WEST. ANOTHER WV FCST TO MV THRU NRN ZONES AFT 06Z TONIGHT AND WITH MOISTURE FM LK ADDED IN EXPECT SVRL INCHES OF SNOW TO FALL ACRS THE FINGER LKS BY 12Z. STORM TOTAL SNOWFALL THRU THE OVRNGT IS NOW LOOKING TO BE MEAGER WITH A GNRL INCH OR TWO ACRS THE BULK OF THE AREA AND POSSIBLY 2-4 INCHES IN HIGHER ELEVATIONS OF SUSQUEHANNA REGION. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... 315 PM UPDATE... MOISTURE WL CONTINUE TO WRAP-ARND THE NOR`EASTER THRU THE SHORT TERM. DEFORMATION BAND FINALLY GETTING ITS ACT TOGETHER CURRENTLY AND WL ROTATE INTO THE FINGER LKS BY MORNING. ADDED MOISTURE OFF OF THE LKS WL LKLY BRING 3-6 INCHES OF SNOW ACRS FINGER LKS AND SUSQUEHANNA REGION DRG THE DAY WED THO AMNTS MAY BE SLIGHTLY HIGHER, THUS HV OPTED TO KEEP WARNINGS GOING FOR CNTRL NY. SYSTEM WL BCM VERTICALLY STACKED DRG THE DAY TOMORROW AND WITH NW FLOW MVG DOWN ACRS THE LKS EXPECT SNOW TO CONTINUE ON WEDNESDAY. ONLY QUESTION WL BE IS IF DRY SLOT WL MV IN FM THE EAST AND DENDRITE ZONE WL LOSE MOISTURE DRG THE AFTN HRS BUT WL ALLOW LATER SHIFTS DECIDE ON DROPPING HEADLINES EARLY. && .LONG TERM /THURSDAY THROUGH TUESDAY/... 3 PM UPDATE... ON THURSDAY...LINGERING SNOW IS EXPECTED WITH MAINLY LOW INTENSITIES. THE CYCLONE WILL STILL BE MOVING SLOWLY THROUGH NORTHERN NEW ENGLAND WITH A PERSISTENT NORTHWEST FLOW ACROSS NY AND PA. THE NORTHWEST FLOW WILL ACTIVATE THE LAKES, BUT TO WHAT TO DEGREE? INVERSION HEIGHTS ARE LOW AND WILL BE LOWERING THROUGHOUT THE LATE AFTERNOON HOURS AND INTO THE EVENING. MOISTURE IS LIMITED TOO. SO...WENT FOR SOMEWHAT HIGHER POPS DOWNWIND OF THE LAKES BUT KEPT SNOW TOTALS ON THE LIGHT SIDE. 130 PM UPDATE... LARGE STACKED LOW STILL OVER NEW ENGLAND ON THURSDAY. SNOW WILL CONTINUE WITH THE GREATEST AMOUNTS OVER NY. NOT COLD ENOUGH FOR SIGNIFICANT LAKE EFFECT BUT SOME ENHANCEMENT LIKELY THU AND FRI. FRI NGT ON LOW MOVES EAST AND UL RIDGE AND SFC HIGH MOVES IN FROM WEST. AS TYPICAL GFS FASTER THAN EURO. POPS LOW ENOUGH THAT KEPT THE CWA DRY FRI NGT TO TUESDAY. SUNDAY TO MONDAY WAA INCREASES ON THE BACK SIDE OF THE RIDGE SFC AND ALOFT. TEMPERATURES WITHIN 5 DEGREES OF AVERAGE. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... RAIN WITH POCKETS OF FREEZING RAIN WILL CHANGE TO SNOW AND SNOW SHOWERS TONIGHT AS LOW PRESSURE REMAINS NEARLY STATIONARY ALONG THE EAST COAST. SNOW SHOWERS WILL PERSIST THROUGH WEDNESDAY. CIGS WILL BE MOSTLY MVFR WITH AREAS OF IFR ESPECIALLY ON HILL TOP AIRPORTS SUCH AS ITH AND BGM. VSBYS WILL FALL TO IFR AS PRECIPITATION CHANGES TO SNOW AND SNOW SHOWERS TONIGHT. WINDS WILL BE LIGHT AND VARIABLE BECOMING NORTH AT 5 TO 10 KTS THIS AFTERNOON THEN NORTHWEST AT 10 TO 15 KTS TONIGHT AND WEDNESDAY WITH GUSTS OF 20 TO 25 KTS WEDNESDAY. OUTLOOK... TUE NGT THROUGH WED...MVFR/IFR IN SNOW OR BLSN. NEAR AIRPORT MINS AT TIMES IN BANDS OF HEAVY SNOW TUE NGT-EARLY WED. THU/FRI...RESTRICTIONS POSSIBLE IN SHSN. BETTER CHC IN NY. SAT...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR PAZ039-040. WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR PAZ038-043- 044-047-048-072. NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ009- 015>018-023-025-036-037-044>046-055>057. WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR NYZ022-024- 062. && $$ SYNOPSIS...PVF NEAR TERM...PVF SHORT TERM...PVF LONG TERM...DJP/TAC AVIATION...DJP/MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
109 PM EST TUE DEC 9 2014 .SYNOPSIS... A VERY SLOWLY MOVING NOR EASTER WILL HAVE A LARGE IMPACT ON THE REGION. MIXED PRECIPITATION WILL BEGIN TO MIX WITH AND CHANGE TO SNOW TONIGHT. LIGHT SNOW ACCUMULATIONS ARE EXPECTED AREAWIDE THROUGH THURSDAY MORNING...AS WELL AS SOME LIGHT ICE ACCUMULATIONS MAINLY AT HIGHER ELEVATIONS. && .NEAR TERM /THROUGH TONIGHT/... 1 PM UPDATE... SFC LOPRES HAS DROPPED DOWN TO NR 1000MB AS IT SPINS OFF THE JERSEY SHORE. MODERATE TO HVY PCPN IS ONGOING ACRS ERN HALF OF CWA AS EXPECTED BUT THERMAL PROFILES ARE TOO WARM FOR SNOW. SOME HIGHER ELEVATION SITES ARE STILL RIGHT AT OR BLO FRZG AS OF 17Z WITH -FZRA FALLING AT THESE LOCATIONS AND HEARING ABOUT NUMEROUS MOTOR VEHICLE ACCIDENTS. PCPN HAS ESSENTIALLY HIT A BRICK WALL AT THE I-81 CORRIDOR AND NOT EXPECTING THIS TO MV MUCH FURTHER EAST THAN WHERE IT CURRENTLY IS NOW UNTIL AFT 00Z. DEFORMATION BAND THAT THE MODELS WERE INSISTENT WUD ROTATE WEST THRU THE EVNG HRS IS NOW LOOKING TO BE A FRACTURED BAND OF MIXED PCPN. H9 TEMPS PER LATEST RUC MODEL INDICATING BLYR TEMPS RMNG ISOTHERMAL THRU 21Z THIS AFTN AND VRY SLOWLY DROPPING BYND THIS TIME. EXPECT A MIXED BAG THRU BULK OF THE OVRNGT FOR SXNS EAST OF I-81 WITH CLD AIR BEING PULLED IN FM THE WEST. ANOTHER WV FCST TO MV THRU NRN ZONES AFT 06Z TONIGHT AND WITH MOISTURE FM LK ADDED IN EXPECT SVRL INCHES OF SNOW TO FALL ACRS THE FINGER LKS BY 12Z. STORM TOTAL SNOWFALL THRU THE OVRNGT IS NOW LOOKING TO BE MEAGER WITH A GNRL INCH OR TWO ACRS THE BULK OF THE AREA AND POSSIBLY 2-4 INCHES IN HIGHER ELEVATIONS OF SUSQUEHANNA REGION. WL DRASTICALLY BE REDUCING SNOW TOTALS FOR THIS EVENT AND WL ALLOW LATER SHIFTS TO MAKE DECISION ON WHETHER TO CANCEL OR DROP WARNINGS DOWN TO ADVISORY. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... 425 AM UPDATE... NOR` EASTER WILL CONTINUE TO IMPACT THE AREA...BECAUSE IT BASICALLY RUNS INTO A BRICK WALL /IN THE FORM OF A VERY STRONG 1045MB HIGH PRESSURE CENTER IN CANADA/ AND SO HAS NOWHERE TO GO. REMAINS OF INITIAL DEFORMATION BAND WILL BE OVER THE CENTRAL SOUTHERN TIER-FINGER LAKES AREA EARLY WEDNESDAY MORNING...WHILE LIGHTER SNOW AND OR FREEZING RAIN-DRIZZLE OCCURS IN THE CENTRAL TO EASTERN ZONES. HOWEVER...THE NOR` EASTER BECOMES VERTICALLY STACKED...WHICH MEANS WE WILL BE VULNERABLE TO ADDITIONAL WAVES ROTATING AROUND IT. MOST GUIDANCE SHOWS ANOTHER SUCH WAVE OF MOISTURE SPINNING UP INTO NEW ENGLAND WEDNESDAY MORNING...THEN WRAPPING BACK ACROSS OUR WEDNESDAY AFTERNOON THROUGH NIGHT. THIS WILL KEEP /OR RETURN/ ACCUMULATING SNOWS ACROSS THE WARNING AREA...HEAVIEST ACROSS OUR NEW YORK ZONES. ALSO...THE STACKED LOW WILL WOBBLE AND THEN RELOCATE DIRECTLY OVER OUR REGION /INSTEAD OF THE COAST/. NORTHWESTERLY WINDS WILL ADVECT COLDER AIR ACROSS OUR REGION AS THIS OCCURS...SO THE SNOW WILL BE OF A FLUFFIER LOWER WATER CONTENT TEXTURE WITH TIME /ESPECIALLY WEDNESDAY NIGHT WITH TEMPERATURES FALLING THROUGH 20S/. IT WILL BECOME MORE SUSCEPTIBLE TO BLOWING AND DRIFTING...THOUGH WINDS THEMSELVES WILL LUCKILY DIMINISH WITH TIME AS WELL. ALL TOLD...STORM SNOW TOTALS...HEAVILY DEPENDENT ON ELEVATION...ARE EXPECTED TO WIDELY RANGE FROM ABOUT A HALF FOOT TO A FOOT OR MORE...HIGHEST IN THE WESTERN CATSKILLS. POINTS OF UNCERTAINTY INCLUDE EXACT POSITIONING AND INTENSITY OF THE MESOSCALE BAND...HOW WELL THE PRIMARY BAND HANGS TOGETHER WHILE SHIFTING WEST AWAY FROM CATSKILLS-POCONOS TONIGHT...AND HOW LOW THE SNOWFALL-TO-LIQUID RATIOS WILL BE /AND THE IMPACT ON TOTALS/. ESPECIALLY DURING THE FIRST HALF OF THE EVENT...THIS WILL NOT BE A FLUFFY EAST-TO-SHOVEL SNOW...BUT RATHER...OF THE WET CRUSTY DENSE KIND ESPECIALLY LOWER ELEVATIONS. && .LONG TERM /THURSDAY THROUGH MONDAY/... 3 PM UPDATE... ON THURSDAY...LINGERING SNOW IS EXPECTED WITH MAINLY LOW INTENSITIES. THE CYCLONE WILL STILL BE MOVING SLOWLY THROUGH NORTHERN NEW ENGLAND WITH A PERSISTENT NORTHWEST FLOW ACROSS NY AND PA. THE NORTHWEST FLOW WILL ACTIVATE THE LAKES, BUT TO WHAT TO DEGREE? INVERSION HEIGHTS ARE LOW AND WILL BE LOWERING THROUGHOUT THE LATE AFTERNOON HOURS AND INTO THE EVENING. MOISTURE IS LIMITED TOO. SO...WENT FOR SOMEWHAT HIGHER POPS DOWNWIND OF THE LAKES BUT KEPT SNOW TOTALS ON THE LIGHT SIDE. 130 PM UPDATE... LARGE STACKED LOW STILL OVER NEW ENGLAND ON THURSDAY. SNOW WILL CONTINUE WITH THE GREATEST AMOUNTS OVER NY. NOT COLD ENOUGH FOR SIGNIFICANT LAKE EFFECT BUT SOME ENHANCEMENT LIKELY THU AND FRI. FRI NGT ON LOW MOVES EAST AND UL RIDGE AND SFC HIGH MOVES IN FROM WEST. AS TYPICAL GFS FASTER THAN EURO. POPS LOW ENOUGH THAT KEPT THE CWA DRY FRI NGT TO TUESDAY. SUNDAY TO MONDAY WAA INCREASES ON THE BACK SIDE OF THE RIDGE SFC AND ALOFT. TEMPERATURES WITHIN 5 DEGREES OF AVERAGE. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... RAIN WITH POCKETS OF FREEZING RAIN WILL CHANGE TO SNOW AND SNOW SHOWERS TONIGHT AS LOW PRESSURE REMAINS NEARLY STATIONARY ALONG THE EAST COAST. SNOW SHOWERS WILL PERSIST THROUGH WEDNESDAY. CIGS WILL BE MOSTLY MVFR WITH AREAS OF IFR ESPECIALLY ON HILL TOP AIRPORTS SUCH AS ITH AND BGM. VSBYS WILL FALL TO IFR AS PRECIPITATION CHANGES TO SNOW AND SNOW SHOWERS TONIGHT. WINDS WILL BE LIGHT AND VARIABLE BECOMING NORTH AT 5 TO 10 KTS THIS AFTERNOON THEN NORTHWEST AT 10 TO 15 KTS TONIGHT AND WEDNESDAY WITH GUSTS OF 20 TO 25 KTS WEDNESDAY. OUTLOOK... TUE NGT THROUGH WED...MVFR/IFR IN SNOW OR BLSN. NEAR AIRPORT MINS AT TIMES IN BANDS OF HEAVY SNOW TUE NGT-EARLY WED. THU/FRI...RESTRICTIONS POSSIBLE IN SHSN. BETTER CHC IN NY. SAT...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR PAZ038>040- 043-044-047-048-072. NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ009- 015>018-022>025-036-037-044>046-055>057-062. && $$ SYNOPSIS...MDP NEAR TERM...PVF SHORT TERM...MDP LONG TERM...DJP/TAC AVIATION...DJP/MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
101 PM EST TUE DEC 9 2014 .SYNOPSIS... A VERY SLOWLY MOVING NOR EASTER WILL HAVE A LARGE IMPACT ON THE REGION. MIXED PRECIPITATION WILL BEGIN TO MIX WITH AND CHANGE TO SNOW TONIGHT. LIGHT SNOW ACCUMULATIONS ARE EXPECTED AREAWIDE THROUGH THURSDAY MORNING...AS WELL AS SOME LIGHT ICE ACCUMULATIONS MAINLY AT HIGHER ELEVATIONS. && .NEAR TERM /THROUGH TONIGHT/... 1 PM UPDATE... SFC LOPRES HAS DROPPED DOWN TO NR 1000MB AS IT SPINS OFF THE JERSEY SHORE. MODERATE TO HVY PCPN IS ONGOING ACRS ERN HALF OF CWA AS EXPECTED BUT THERMAL PROFILES ARE TOO WARM FOR SNOW. SOME HIGHER ELEVATION SITES ARE STILL RIGHT AT OR BLO FRZG AS OF 17Z WITH -FZRA FALLING AT THESE LOCATIONS AND HEARING ABOUT NUMEROUS MOTOR VEHICLE ACCIDENTS. PCPN HAS ESSENTIALLY HIT A BRICK WALL AT THE I-81 CORRIDOR AND NOT EXPECTING THIS TO MV MUCH FURTHER EAST THAN WHERE IT CURRENTLY IS NOW UNTIL AFT 00Z. DEFORMATION BAND THAT THE MODELS WERE INSISTENT WUD ROTATE WEST THRU THE EVNG HRS IS NOW LOOKING TO BE A FRACTURED BAND OF MIXED PCPN. H9 TEMPS PER LATEST RUC MODEL INDICATING BLYR TEMPS RMNG ISOTHERMAL THRU 21Z THIS AFTN AND VRY SLOWLY DROPPING BYND THIS TIME. EXPECT A MIXED BAG THRU BULK OF THE OVRNGT FOR SXNS EAST OF I-81 WITH CLD AIR BEING PULLED IN FM THE WEST. ANOTHER WV FCST TO MV THRU NRN ZONES AFT 06Z TONIGHT AND WITH MOISTURE FM LK ADDED IN EXPECT SVRL INCHES OF SNOW TO FALL ACRS THE FINGER LKS BY 12Z. STORM TOTAL SNOWFALL THRU THE OVRNGT IS NOW LOOKING TO BE MEAGER WITH A GNRL INCH OR TWO ACRS THE BULK OF THE AREA AND POSSIBLY 2-4 INCHES IN HIGHER ELEVATIONS OF SUSQUEHANNA REGION. WL DRASTICALLY BE REDUCING SNOW TOTALS FOR THIS EVENT AND WL ALLOW LATER SHIFTS TO MAKE DECISION ON WHETHER TO CANCEL OR DROP WARNINGS DOWN TO ADVISORY. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... 425 AM UPDATE... NOR` EASTER WILL CONTINUE TO IMPACT THE AREA...BECAUSE IT BASICALLY RUNS INTO A BRICK WALL /IN THE FORM OF A VERY STRONG 1045MB HIGH PRESSURE CENTER IN CANADA/ AND SO HAS NOWHERE TO GO. REMAINS OF INITIAL DEFORMATION BAND WILL BE OVER THE CENTRAL SOUTHERN TIER-FINGER LAKES AREA EARLY WEDNESDAY MORNING...WHILE LIGHTER SNOW AND OR FREEZING RAIN-DRIZZLE OCCURS IN THE CENTRAL TO EASTERN ZONES. HOWEVER...THE NOR` EASTER BECOMES VERTICALLY STACKED...WHICH MEANS WE WILL BE VULNERABLE TO ADDITIONAL WAVES ROTATING AROUND IT. MOST GUIDANCE SHOWS ANOTHER SUCH WAVE OF MOISTURE SPINNING UP INTO NEW ENGLAND WEDNESDAY MORNING...THEN WRAPPING BACK ACROSS OUR WEDNESDAY AFTERNOON THROUGH NIGHT. THIS WILL KEEP /OR RETURN/ ACCUMULATING SNOWS ACROSS THE WARNING AREA...HEAVIEST ACROSS OUR NEW YORK ZONES. ALSO...THE STACKED LOW WILL WOBBLE AND THEN RELOCATE DIRECTLY OVER OUR REGION /INSTEAD OF THE COAST/. NORTHWESTERLY WINDS WILL ADVECT COLDER AIR ACROSS OUR REGION AS THIS OCCURS...SO THE SNOW WILL BE OF A FLUFFIER LOWER WATER CONTENT TEXTURE WITH TIME /ESPECIALLY WEDNESDAY NIGHT WITH TEMPERATURES FALLING THROUGH 20S/. IT WILL BECOME MORE SUSCEPTIBLE TO BLOWING AND DRIFTING...THOUGH WINDS THEMSELVES WILL LUCKILY DIMINISH WITH TIME AS WELL. ALL TOLD...STORM SNOW TOTALS...HEAVILY DEPENDENT ON ELEVATION...ARE EXPECTED TO WIDELY RANGE FROM ABOUT A HALF FOOT TO A FOOT OR MORE...HIGHEST IN THE WESTERN CATSKILLS. POINTS OF UNCERTAINTY INCLUDE EXACT POSITIONING AND INTENSITY OF THE MESOSCALE BAND...HOW WELL THE PRIMARY BAND HANGS TOGETHER WHILE SHIFTING WEST AWAY FROM CATSKILLS-POCONOS TONIGHT...AND HOW LOW THE SNOWFALL-TO-LIQUID RATIOS WILL BE /AND THE IMPACT ON TOTALS/. ESPECIALLY DURING THE FIRST HALF OF THE EVENT...THIS WILL NOT BE A FLUFFY EAST-TO-SHOVEL SNOW...BUT RATHER...OF THE WET CRUSTY DENSE KIND ESPECIALLY LOWER ELEVATIONS. && .LONG TERM /THURSDAY THROUGH MONDAY/... 3 PM UPDATE... ON THURSDAY...LINGERING SNOW IS EXPECTED WITH MAINLY LOW INTENSITIES. THE CYCLONE WILL STILL BE MOVING SLOWLY THROUGH NORTHERN NEW ENGLAND WITH A PERSISTENT NORTHWEST FLOW ACROSS NY AND PA. THE NORTHWEST FLOW WILL ACTIVATE THE LAKES, BUT TO WHAT TO DEGREE? INVERSION HEIGHTS ARE LOW AND WILL BE LOWERING THROUGHOUT THE LATE AFTERNOON HOURS AND INTO THE EVENING. MOISTURE IS LIMITED TOO. SO...WENT FOR SOMEWHAT HIGHER POPS DOWNWIND OF THE LAKES BUT KEPT SNOW TOTALS ON THE LIGHT SIDE. 130 PM UPDATE... LARGE STACKED LOW STILL OVER NEW ENGLAND ON THURSDAY. SNOW WILL CONTINUE WITH THE GREATEST AMOUNTS OVER NY. NOT COLD ENOUGH FOR SIGNIFICANT LAKE EFFECT BUT SOME ENHANCEMENT LIKELY THU AND FRI. FRI NGT ON LOW MOVES EAST AND UL RIDGE AND SFC HIGH MOVES IN FROM WEST. AS TYPICAL GFS FASTER THAN EURO. POPS LOW ENOUGH THAT KEPT THE CWA DRY FRI NGT TO TUESDAY. SUNDAY TO MONDAY WAA INCREASES ON THE BACK SIDE OF THE RIDGE SFC AND ALOFT. TEMPERATURES WITHIN 5 DEGREES OF AVERAGE. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SCATTERED FREEZING RAIN IS OVER AVP AND BGM THIS MORNING. A RAIN/FREEZING RAIN MIX IS FORECAST TO SPREAD INTO ELM, SYR, ITH, AND RME BETWEEN 14Z AND 17Z, THEN CHANGE TO ALL RAIN FOR THE MID AFTERNOON. WIDESPREAD MVFR CONDITIONS ARE FORECAST WITH THE PRECIPITATION ARRIVAL. BGM AND ITH WILL LIKELY HAVE IFR CEILINGS. THE PRECIPITATION WILL CHANGE TO SNOW DURING THE LATE AFTERNOON, WITH IFR CONDITIONS FORECAST THROUGH THE EVENING AND OVERNIGHT HOURS IN MODERATE SNOW. OUTLOOK... TUE NGT THROUGH WED...MVFR/IFR IN SNOW OR BLSN. NEAR AIRPORT MINS AT TIMES IN BANDS OF HEAVY SNOW TUE NGT-EARLY WED. THU/FRI...RESTRICTIONS POSSIBLE IN SHSN. BETTER CHC IN NY. SAT...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR PAZ038>040- 043-044-047-048-072. NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ009- 015>018-022>025-036-037-044>046-055>057-062. && $$ SYNOPSIS...MDP NEAR TERM...PVF SHORT TERM...MDP LONG TERM...DJP/TAC AVIATION...DJP
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
338 PM CST TUE DEC 9 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 328 PM CST TUE DEC 9 2014 CHALLENGE CONTINUES TO BE EVOLUTION OF STRATUS DECK AND ITS IMPACT ON TEMPS NOT ONLY TONIGHT BUT PROBABLY FOR THE NEXT FEW DAYS. MODELS POOR WITH HANDLING THESE LOW LEVEL MOIST LAYERS IN THE COLD SEASON...NOT MUCH CONFIDENCE WRT STRATUS AS A RESULT. AFOREMENTIONED WARM UP BEGINS AS WEAK SHORT WAVE MOVES TO THE SE TONIGHT AND 500MB HEIGHTS BEGIN TO BUILD. SFC WINDS TO REMAIN WELL MIXED OVERNIGHT WITH WAA AS 850MB TEMPS BEGIN TO CLIMB...STRENGTHENING THE INVERSION AND ALLOWING THE STRATUS DECK TO REMAIN ALL THE WHILE LIMITING ANY FOG THAT WE SAW LAST NIGHT AS TEMPS FALL VERY LITTLE OVERNIGHT. WESTERN EDGE OF STRATUS DECK IS EXPECTED TO ERODE ACROSS THE DVL BSN AND POSSIBLE INTO THE RRV. MID 30S IF CLOUDS SCT OUT OTHERWISE THE UPR 20S CAN BE EXPECTED FOR WEDNESDAY MAX TEMPS. WEDNESDAY NIGHT WILL CONTINUE TO SEE THE SOUTH WINDS AND DEAL WITH THE THREAT OF A STRATUS DECK. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 328 PM CST TUE DEC 9 2014 THURSDAY TO FRIDAY RIDGING AT 500MB CONTINUES TO BUILD WITH INCREASES THICKNESSES AND WARMING LOW LEVELS. HIGHS THURSDAY AND FRIDAY WILL BE GOVERNED BY LOW LEVEL CLOUDS...MORE LIKELY THE FARTHER EAST WHERE MIXING WILL BE LESS AND FLOW REMAINS TRULY SOUTHERLY. THURSDAY MAX T 40S WEST MID 30S RRV AND LOW 30S EAST...FRIDAY MORNING LOWS WILL BE NEAR NORMAL HIGHS WITH READINGS IN THE MID 20S WITH DAYTIME HIGHS INTO THE 40S RRV AND WEST WITH UPR 30S EAST. FRIDAY NIGHT THROUGH TUESDAY...THE UPPER RIDGING BUILDING OVER THE UPPER MIDWEST WILL CONTINUE TO BRING WARMER THAN AVERAGE TEMPS INTO THE WEEKEND. EVEN WITH CLOUDS LINGERING OVER THE EASTERN COUNTIES THERE WILL BE ENOUGH WARM AIR MASS AND MOISTURE TO BRING TEMPS INTO THE 30S AND EVEN SOME LOW 40S POSSIBLE IN THE SOUTH ON SATURDAY. THE WINDS WILL SHIFT TO THE NORTHWEST AND START SCOURING OUT LOW LEVEL MOISTURE ON SUNDAY...BUT WITH THE APPROACHING NORTHERN BRANCH SHORTWAVE THERE WILL STILL BE CLOUDS AND AN INCREASING CHANCE FOR PRECIP. WITH WARM TEMPS SATURDAY NIGHT AND SUNDAY KEPT A RAIN/SNOW MIX IN THE SOUTH FOR NOW AND WILL REFINE AS THE TIME PERIOD GETS CLOSER. AFTER THE COLD FRONT MOVES THROUGH ON SUNDAY...TEMPS WILL BE CLOSER TO NORMAL WITH HIGHS IN THE 20S FOR MONDAY AND TUESDAY. THE ECMWF HAS ANOTHER SHORTWAVE FOR TUESDAY WHILE THE GFS KEEPS RIDGING. CONSIDERING NAEFS DOES NOT HAVE MUCH FOR PRECIP PROBABILITIES WILL LEAN CLOSE TO ALLBLEND FOR NOW AND REMAIN DRY FOR THE EARLY PART OF THE WORK WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1244 AM CST TUE DEC 9 2014 SOME OF THE LOW LEVEL CLOUDS HAVE CLEARED OUT OF THE NORTHERN RED RIVER VALLEY AND THE DEVILS LAKE BASIN. HOWEVER...SOUTHERN LOCATIONS ARE STILL SOCKED IN AND WINDS ARE FROM THE SOUTH...AND MORE STRATUS IS OUT OVER WESTERN PORTIONS OF THE CWA. GFS AND SREF PROBABILITIES ARE NOT HANDLING THE CURRENT LOW CLOUDS VERY WELL SO WILL DISREGARD THOSE SOLUTIONS. THE NAM...HRRR...AND RAP ARE MUCH MORE PESSIMISTIC FOR CIGS SO WILL LEAN IN THAT DIRECTION. THINK THAT THE SOUTHERN AND EASTERN SPOTS THAT ARE STILL IFR WILL SEE SOME IMPROVEMENT TO MVFR FOR A BRIEF PERIOD THIS AFTERNOON...BUT THEN GO BACK INTO THE SOUP TONIGHT. THINK THERE SHOULD BE QUITE A LOT OF IFR CIGS...AND SOME GUIDANCE IS PUTTING IN SOME VIS IN THE 3 TO 5SM RANGE...BUT WILL JUST KEEP CIGS LOW FOR NOW AND ADD ANY VIS RESTRICTIONS LATER. WILL CONTINUE TO KEEP STRATUS LINGERING OVER THE AREA THROUGH THE END OF THE PERIOD AS THERE WILL BE SOUTH TO SOUTHEAST WINDS AT 10 TO 15 KTS THAT WILL HAVE A TOUGH TIME SCOURING OUT CLOUDS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...JK LONG TERM...JK/JR AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1246 PM CST TUE DEC 9 2014 .UPDATE... ISSUED AT 1244 AM CST TUE DEC 9 2014 TWEAKING SKY GRIDS AGAIN AS STRATUS DECK ACROSS THE DVL BASIN HAS ERODED AND SKIES HAVE CLEARED. EXPECTING SOME LOW STRATUS TO ADVECT NORTH NORTHWEST FROM MN SIDE OF RRV AS VISIBLE SATELLITE SHOWS EDGE NEARING GFK. UNCERTAINTY ABOUNDS ON THE EVOLUTION OF THE CLOUD DECK ACROSS E ND THIS EVENING AND OVERNIGHT. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 250 AM CST TUE DEC 9 2014 MAIN FORECAST CHALLENGES WILL BE DEALING WITH THE FOG/FLURRIES AND LOW CLOUDS THAT CONTINUE TO PERSIST ACROSS MOST OF THE FA. AS OF 3 AM QUITE A FEW STATIONS CONTINUED TO REPORT FOG OR FLURRIES SO HAVE EXTENDED THE MENTION OF THESE THRU MID MORNING. ALSO KEPT THE LOW CLOUDS ABOUT WHERE THEY WERE THRU MID MORNING AND THEN TRIED TO FOLLOW A DECREASING TREND. WILL HAVE TO MONITOR THESE THRU THE EARLY MORNING HOURS AND CONTINUE TO ADJUST IF NEED BE. WITH THE SFC HIGH OVERHEAD AND LIGHT WINDS TURNING AROUND TO THE SOUTH IN THE MORNING REALLY DO NOT EXPECT MUCH CHANGE IN THE STATUS QUO. LARGER SCALE MODELS NOT HANDLING THESE DETAILS SO HAVE LEANED MORE ON THE HIGH RESOLUTION RAP/HRRR. 850MB TEMPS CONTINUE TO WARM TODAY GETTING TO ABOUT 2C-6C BY 00Z WED WHICH WILL ONLY STRENGTHEN THE INVERSION...NOT HELPING TO GET RID OF THE LOW CLOUDS. OF COURSE IF THE CLOUDS DO HANG AROUND LONGER THAN EXPEC