Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/05/16


AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS LITTLE ROCK AR
1055 PM CST WED MAR 2 2016 .AVIATION... CLOUDS WILL THICKEN OVERNIGHT...WITH WIDESPREAD MVFR/SOME IFR CONDITIONS LATE TONIGHT/THURSDAY MORNING. SHOWERS WILL BECOME WIDESPREAD...WITH ISOLATED THUNDERSTORMS. PRECIPITATION WILL END BY THE EARLY AFTERNOON THURSDAY. CLOUDS WILL DECREASE...WITH VFR CONDITIONS RETURNING. WINDS TONIGHT WILL BE SOUTHEAST AT 8 TO 14 MPH...AND WILL SHIFT TO THE NORTHWEST AT 10 TO 18 MPH THURSDAY. (46) && .SHORT TERM...TONIGHT THRU THURSDAY NIGHT... NWLY FLOW ALOFT CONTINUING THIS EVENING IN ADVANCE OF NEXT SYSTEM WHICH WILL BE MOVING DOWN AND DEVELOPING RATHER QUICKLY FROM THE NW. THIS WILL BEGIN AFFECTING THE WEATHER ACROSS THE AREA TONIGHT AND CONTINUING THROUGH TOMORROW. ASSOCIATED COLD FRONT WILL BE MOVING THROUGH THE STATE TOMORROW...ALTHOUGH THERE WILL NOT BE TOO SUBSTANTIAL OF A COOL DOWN WITH THIS AIR MASS...BASICALLY 5 TO 10 DEGREES AT BEST. LARGE SCALE ASCENT AHEAD OF THE LOW AND SFC BASED LIFT WITH THE FRONT SHOULD TRANSLATE INTO GREATER POPS THAN IS PRESENT IN THE EXISTING FORECAST. SHORTER TERM HRRR AND THE NAM ARE IN GOOD AGREEMENT WITH THIS SCENARIO. THIS WOULD RESULT IN PRECIP IN GREATER COVERAGE THAN IS COVERED IN THE EXISTING FORECAST...SO I AM BOOSTING POPS UP QUITE A BIT OVER THE EXISTING FORECAST. ONLY LIMITING FACTOR WILL BE LOW LEVEL MOISTURE AVAILABILITY...WITH LIMITED MOISTURE FROM THE SFC THROUGH THE MID LEVELS. FOR THIS REASON I SCALED BACK MODEL BASED QPF VALUES SOMEWHAT. AS FOR THUNDERSTORM CHANCES OVERNIGHT INTO TOMORROW...THE DYNAMICS OF THE APPROACHING SYSTEM LOOK GOOD. RATHER STEEP MID LEVEL LAPSE RATES WILL BE IN PLACE...WITH QUITE A BIT OF UPPER LEVEL DIFLUENCE ASSOCIATED WITH A RATHER STRONG JET. ON THE DOWNSIDE THE OVERALL PARCEL INSTABILITY IS WEAK...AND THE AFOREMENTIONED MOISTURE LIMITATIONS WILL BE A FACTOR. FOR NOW I AM WORDING THE WEATHER GRIDS AS SHOWERS WITH THE POSSIBILITY OF ISOLATED THUNDERSTORMS. HOWEVER IF OVERNIGHT TRENDS START TO SHOW MORE LIGHTNING...THIS MAY NEED TO BE ADJUSTED TO FAVOR THUNDERSTORMS MORE PROMINENTLY. && .LONG TERM...THURSDAY THROUGH TUESDAY... THE UPPER LEVEL PATTERN WILL REMAIN ACTIVE DURING THE LONG TERM FORECAST PERIOD...WITH THE POSSIBILITY OF A SIGNIFICANT ROUND OF THUNDERSTORMS ON TUESDAY NEXT WEEK. HIGH PRESSURE WILL BE SITUATED OVER THE STATE ON FRIDAY BUT WILL PUSH OFF TO THE EAST AS ANOTHER FRONT MOVES INTO THE REGION SATURDAY. THIS FRONT WILL BE A DRY FRONT BUT IT WILL STALL OUT AND BE A FOCUS FOR PRECIPITATION DEVELOPMENT ON SUNDAY AS IT LIFTS BACK NORTH THROUGH THE STATE AS A WARM FRONT. STARTING SUNDAY...SEVERAL IMPULSES WILL LIFT NORTHEAST THROUGH THE ARKLATEX REGION AS A VERY DEEP TROUGH SETS UP SHOP ACROSS THE WESTERN CONUS. EACH OF THESE IMPULSES WILL BRING SHOWERS AND THUNDERSTORMS TO THE STATE...MAINLY TO WESTERN ARKANSAS SUNDAY AND MONDAY. THE FIRST WILL MOVE THROUGH SUNDAY NIGHT...FOLLOWED BY ANOTHER MONDAY EVENING...AND FINALLY A STRONGER ONE ON TUESDAY. MOISTURE RETURN WILL INCREASE WITH TIME AS THE GULF OF MEXICO OPENS UP...WITH MODELS FORECASTING DEWPOINTS 60-65F ACROSS MUCH OF THE STATE MONDAY NIGHT INTO TUESDAY. MODELS HAVE BEEN FAIRLY CONSISTENT IN SHOWING SIGNIFICANT PRECIPITATION AND THE CHANCE FOR STRONG TO SEVERE THUNDERSTORMS ACROSS THE REGION ON TUESDAY. IT IS STILL THE DAY 7 FORECAST PERIOD WHICH IS TO SAY THERE IS A LOT OF TIME FOR THIS TO CHANGE. BUT WILL NEED TO MONITOR THIS SITUATION AS SEVERE STORMS COULD BE A DISTINCT POSSIBILITY. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 45 61 38 58 / 70 50 0 0 CAMDEN AR 52 71 41 67 / 50 50 0 0 HARRISON AR 43 58 34 61 / 50 30 0 0 HOT SPRINGS AR 48 67 40 64 / 70 30 0 0 LITTLE ROCK AR 47 65 40 62 / 70 40 0 0 MONTICELLO AR 51 67 42 62 / 60 70 0 0 MOUNT IDA AR 48 66 38 65 / 60 30 0 0 MOUNTAIN HOME AR 45 59 35 60 / 60 30 0 0 NEWPORT AR 43 61 38 56 / 60 70 10 0 PINE BLUFF AR 46 64 40 61 / 50 40 0 0 RUSSELLVILLE AR 46 65 37 63 / 80 30 0 0 SEARCY AR 45 62 38 59 / 70 70 0 0 STUTTGART AR 46 63 39 59 / 60 60 0 0 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...53 / LONG TERM...64
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
904 AM MST THU MAR 3 2016 .SYNOPSIS... A VERY STRONG HIGH PRESSURE SYSTEM WILL CONTINUE TO PRODUCE VERY WARM NEAR RECORD TEMPERATURES ACROSS THE REGION THROUGH SATURDAY. HOWEVER...LOW PRESSURE MOVING INLAND FROM THE EASTERN PACIFIC WILL FINALLY BRING MUCH COOLER TEMPERATURES WITH A GOOD CHANCE FOR RAIN AND MOUNTAIN SNOW FROM SUNDAY ONWARD INTO EARLY NEXT WEEK. DRIER AND WARMER WEATHER WILL THEN RETURN DURING THE MIDDLE PART OF NEXT WEEK AS HIGH PRESSURE REBUILDS INTO THE DESERT SOUTHWEST. && .DISCUSSION... LATEST SATELLITE IMAGERY AND STREAMLINE ANALYSIS SHOWS A DIRTY RIDGE IN PLACE WITH CIRRUS IN THE PACIFIC SPILLING OVER INTO THE DESERT SOUTHWEST. 12Z SOUNDING FROM KTWC SHOWS WARM TEMPERATURES AT 850 MB AROUND THE 90TH PERCENTILE. HOWEVER...MEDIAN OF MORNING MULTI-MODEL ENSEMBLE INCLUDING THE HRRR SUGGESTS AFTERNOON TEMPERATURES MAY NOT REACH THEIR FULL POTENTIAL...DUE TO THE DECREASED INSOLATION. FORECAST HIGH TEMPERATURES WILL BE LOWERED ROUGHLY ONE DEGREE THIS MORNING. NEVERTHELESS...HIGH TEMPERATURES WILL BE WITHIN A FEW DEGREES OF THE RECORD IN PHOENIX BUT SEVERAL DEGREES SHORT IN YUMA. && .PREVIOUS DISCUSSION... TODAY THROUGH SATURDAY... VERY WARM WEATHER IS STILL EXPECTED TO PREVAIL DURING THIS PERIOD AS STRONG HIGH PRESSURE ALOFT MOVES SLOWLY EASTWARD ACROSS THE REGION. 500MB HEIGHTS ARE STILL FORECAST O REMAIN IN THE 576-582DM RANGE THROUGH FRIDAY...AOA THE 95TH PERCENTILE...THEN LOWER A BIT ON SATURDAY AS THE 1ST IN THE SERIES OF STRONG SHORTWAVES BEGINS TO MOVE INLAND ACROSS CENTRAL AND NORTHERN CA. THE COMBINATION OF THESE VERY HIGH HEIGHTS AND 850 MB TEMPS IN THE 17-20C RANGE WILL ONCE AGAIN ALLOW LOWER DESERT HIGHS TO RISE INTO THE UPPER 80-LOW 90 RANGE TODAY AND FRIDAY...THEN FALL A BIT...INTO THE MID-UPPER 80S ON SATURDAY...THREATENING...OR EVEN BREAKING DAILY RECORDS. SUNDAY THROUGH TUESDAY... A SIGNIFICANT CHANGE IN THE WEATHER NOW SEEMS ALMOST CERTAIN FOR THIS PERIOD...AS THERE IS NOW GOOD-EXCELLENT MODEL AGREEMENT THAT TWO MAJOR SHORTWAVES WILL BE MOVING INTO THE REGION. THE 1ST ONE...WHICH IS EXPECTED TO MOVE INTO THE REGION ON SUNDAY...IS THE WEAKER OF THE TWO. THE MAIN IMPACT FROM THIS SHORTWAVE WILL BE TO FINALLY PUSH THE STRONG HIGH PRESSURE RIDGING THAT IS NOW BRINGING US VERY WARM WEATHER WELL OFF TO OUR EAST. ALTHOUGH MOST OF THE DYNAMICS...AND AVAILABLE MOISTURE ASSOCIATED WITH THIS SHORTWAVE IS EXPECTED TO REMAIN TO OUR NORTH...ALL OF THE 3 MAIN GLOBAL MODELS DO PUSH ENOUGH MOISTURE INTO THE NORTHERNMOST PORTIONS OF OUR CWA TO PRODUCE AT LEAST A SLIGHT CHANCE OF SHOWERS IN THOSE AREAS. THE MAIN IMPACTS FOR MOST OF OUR CWA WILL BE TO COOL TEMPERATURES DOWN INTO THE UPPER 70-LOW 80 RANGE ACROSS THE LOWER DESERTS AND TO BRING GUSTY WESTERLY WINDS TO MOST LOCATIONS ON SUNDAY AFTERNOON...WITH SUSTAINED WIND SPEEDS RISING INTO THE 25-35 MPH RANGE...WITH AREAS OF BLOWING DUST POSSIBLE...AS A 80 KT WESTERLY JET AT 300MB MOVES INTO THE REGION. A SECOND...STRONG SHORTWAVE/UPPER LOW IS THEN FORECAST TO MOVE INTO OUR CWA DURING THE MONDAY AFTERNOON-TUESDAY PERIOD. THERE IS A RATHER TIGHT SPREAD (FOR THIS FAR OUT) BETWEEN THE VARIOUS GLOBAL MODELS...AND THE MAJORITY OF THEIR RESPECTIVE ENSEMBLE MEMBERS ON THE TRACK AND INTENSITY OF THIS SHORTWAVE/UPPER LOW. THE MODEL CONSENSUS IS TO MOVE THE UPPER LOW CENTER SE-WARD ACROSS CA ON MONDAY AND MONDAY NIGHT...THEN INTO NORTHERN SONORA MEXICO ON TUESDAY. ALTHOUGH THIS TRACK WILL BRING SOME IMPRESSIVE DIFLUENCE/HEIGHT FALLS/COOLING ALOFT TO OUR CWA...WITH 500MB TEMPERATURES FALLING AS LOW AS -26C...MOISTURE NOW APPEARS IT WILL BE A BIT LIMITED...WITH PWATS ONLY RISING INTO THE 0.6-0.8 INCH RANGE AS THE ATMOSPHERIC RIVER ASSOCIATED WITH THIS SYSTEM BECOMES PINCHED OFF AS IT MOVES DOWN THE CA COAST...WITH MOST PLACES SEEING 1/3 INCH OF RAIN...OR LESS. STILL...LOCALLY HEAVIER RAINFALL AMOUNTS CAN BE EXPECTED AS THE STRONG DYNAMICS/COOLING ALOFT TRIGGER SOME HEAVIER SHOWERS/THUNDERSTORMS. RAINFALL AMOUNTS COULD BE LIMITED FURTHER IF THE UPPER LOW LOW TRACKS FURTHER TO THE SOUTH...WHICH MANY OF THE OUTLYING ENSEMBLE MEMBERS ARE SUGGESTING AT THIS TIME. AS FAR AS SNOWFALL IS CONCERNED...IT APPEARS THAT ACCUMULATING SNOWS WILL BE CONFINED TO THE HIGHEST PEAKS OF OUR CWA...WHERE A COUPLE OF INCHES MAY FALL LATE MONDAY NIGHT/EARLY TUESDAY. ALONG WITH THE PRECIP CHANCES...MUCH COOLER TEMPERATURES ARE EXPECTED...WITH LOWER DESERT HIGHS REMAINING IN THE UPPER 60-MID 70 RANGE. WEDNESDAY THROUGH THURSDAY. A DRYING AND WARMING TREND IS EXPECTED DURING THIS PERIOD AS HIGH PRESSURE BUILDS BACK OVER THE REGION BEHIND THE UPPER TROF...WITH HIGHS LIKELY TO REBOUND UP INTO THE UPPER 70-LOW 80 RANGE BY THURSDAY. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... VERY MUCH A PERSISTENCE FORECAST FOR THE NEXT 24 HOURS AS STRONG HIGH PRESSURE ALOFT CONTINUES TO DOMINATE THE WEATHER PATTERN OVER THE DESERT SOUTHWEST. EXPECT MAINLY THIN BROKEN CIRRUS DECKS THROUGH THIS EVENING AT THE TAF SITES WITH SOME THINNING OF THE CLOUDS FROM THE WEST OVERNIGHT TONIGHT. LIGHT GRADIENTS PERSIST AND WE CAN EXPECT MOSTLY LIGHT WINDS FAVORING NORMAL DIURNAL TENDENCIES... ESPECIALLY IN THE GREATER PHOENIX AREA...NEXT 24 HOURS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY...OVER THE WEEKEND THE HIGH PRESSURE SYSTEM THAT HAS PROVIDED NEAR RECORD HIGH TEMPERATURES EARLIER THIS WEEK WILL BREAK DOWN AS A STRONG PACIFIC LOW PRESSURE SYSTEM MOVES INTO THE WEST COAST. A COOLING TREND WILL DEVELOP AND A SHARP INCREASE IN WIND IS EXPECTED AS THE FIRST IN A SERIES OF DISTURBANCES MOVES ACROSS THE AREA LEADING TO A SLIGHT CHANCE OF SHOWERS AREA WIDE ON SUNDAY. STRONG GUSTY SOUTHWEST WINDS WILL DEVELOP DURING THE DAY SUNDAY WITH AFTERNOON GUSTS IN EXCESS OF 30 MPH OVER MUCH OF THE WESTERN DESERTS. MINIMUM HUMIDITY LEVELS INCREASE FROM THE WEST OVER THE WEEKEND WITH MOST LOWER DESERTS RISING INTO THE 15 TO 20 PERCENT BALLPARK ON SUNDAY. FOR MONDAY INTO TUESDAY...THERE WILL BE A SIGNIFICANT INCREASE IN HUMIDITY AS A STRONGER LOW PRESSURE SYSTEM MOVES ACROSS THE AREA BRINGING A GOOD CHANCE OF SHOWERS ALONG WITH POTENTIAL FOR WETTING RAINS. GUSTY WEST TO NORTHWEST WINDS WILL CONTINUE BOTH DAYS ESPECIALLY OVER THE WESTERN ARIZONA AND SOUTHEAST CALIFORNIA DESERT. THE INCREASE IN WIND SUNDAY INTO EARLY NEXT WEEK WILL BE OFFSET BY THE INCREASING SURFACE HUMIDITY AND THIS WILL LIMIT THE CHANCES THAT CRITICAL FIRE WEATHER THRESHOLDS WILL BE MET. OF COURSE...MUCH COOLER TEMPERATURES WILL ACCOMPANY THE PASSAGE OF THE DISTURBANCE WITH HIGHS FALLING BELOW SEASONAL NORMALS MONDAY OVER THE DESERTS...WITH SOME WARMING EXPECTED OVER THE WESTERN DESERTS TUESDAY. ON WEDNESDAY...DRIER AND WARMER CONDITIONS ARE EXPECTED ALONG WITH MUCH LESS WIND AS HIGH PRESSURE BUILDS INTO THE DESERTS FROM THE WEST. && .CLIMATE... PHOENIX | YUMA FCST | RECORD /YEAR/ | FCST | RECORD /YEAR/ HIGH HIGH THU MAR 3 90 | 91 /1921 | 91 | 95 /1910 FRI MAR 4 90 | 88 /1972 | 89 | 98 /1910 SAT MAR 5 87 | 93 /1972 | 88 | 97 /1910 && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH PREVIOUS DISCUSSION...PERCHA AVIATION...CB FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS TAUNTON MA
643 PM EST FRI MAR 4 2016 .SYNOPSIS... STRONG OFFSHORE LOW PRESSURE WILL SKIRT SOUTHEAST NEW ENGLAND TONIGHT WITH HIGH PRESSURE FILLING IN BEHIND THE LOW ON SATURDAY. ALBERTA CLIPPER RACES SOUTH OF NEW ENGLAND SUNDAY. HIGH PRESSURE THEN BUILDS MILDER WEATHER OVER OUR AREA THE FIRST HALF OF NEXT WEEK. LOW PRESSURE RACES THROUGH EASTERN CANADA MIDWEEK AND PULLS A COLD FRONT THROUGH NEW ENGLAND THURSDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 630 PM UPDATE... NO MAJOR CHANGES TO THE FORECAST AT THIS TIME. MAIN CHANGE WAS TO ADJUST SKY COVER A LITTLE FARTHER WEST EARLY TONIGHT BUT MAINTAINING THE CLEARING TREND OVERNIGHT. SYSTEM SNOW IS OVER CAPE COD AND THE ISLANDS WITH NORTH-NORTHEAST WINDS BRINGING OCEAN SNOW SHOWERS INTO THE NORTH SHORE AND INTO EAST COASTAL PLYMOUTH COUNTY. THIS SHOULD CONTINUE FOR THE NEXT COUPLE OF HOURS AND THEN SHOW A DIMINISHING TREND AFTER 9 PM. WINDS NEAR THE COAST HAVE BEEN A LITTLE LOWER THAN FORECAST AND SO WE WILL BRING WINDS/GUSTS DOWN A SMIDGE BUT MAINTAIN A WINDY NIGHT ALONG THE COAST. TEMPERATURES ARE WITHIN A DEGREE OR TWO OF FORECAST LEVELS AND SO NO CHANGES AT THIS TIME. PREVIOUS DISCUSSION... STRONG OFFSHORE SYSTEM WILL CONTINUE TO DEEPEN THIS EVENING AS IT MAKES ITS EASTWARD PROGRESSION SOUTH AND EAST OF THE 40N/70W BENCHMARK. LATEST WATER VAPOR IMAGERY SHOWS CLASSIC LEAF PATTERN WHEN THE LOW IS UNDERGOING CYCLOGENESIS. THIS RAMP-UP WILL INCREASE THE PRESSURE GRADIENT ALLOWING 925 MB JET TO INCREASE 40-50 KTS. ONE CONCERN FOR SNOW IS ACROSS THE MASS EAST COAST INCLUDING THE NORTH SHORE. WENT AHEAD AN ISSUED A WINTER WEATHER ADVISORY FOR ESSEX COUNTY. HI-RES GUIDANCE CONTINUES TO SHOW A NARROW BAND OF HIGHER QPF LATER THIS AFTERNOON INTO THE EVENING HOURS. THIS IS IN ASSOCIATION WITH THE RE-DEVELOPMENT OF OCEAN EFFECT SNOW MOVING ONSHORE. THE LATEST NAM12 AS WELL AS THE HRRR ARE ALSO ON BOARD. ONE INTERESTING NOTE IS THAT THE RAP GUIDANCE IS SHOWING INSTABILITY OVER THE NORTH SHORE FOR MUCH OF THE AFTERNOON INTO THE EVENING. THIS INSTABILITY COMBINED WITH THE DEVELOPMENT OF A COASTAL FRONT WILL HELP ENHANCE THE OCEAN EFFECT SNOW SHOWERS MORE SO THEN WHAT GUIDANCE IS INDICATING. COULD SEE ANOTHER 1-3 INCHES FOR ESSEX COUNTY...WHICH WILL BE ON TOP OF THE 1-2 THAT PORTIONS OF THAT AREA HAS ALREADY SEEN. ONCE THE SNOW SHOWERS DEVELOP...BELIEVE THEY WILL MOVE SOUTHWARD THANKS TO THE NORTHERLY DIRECTION OF THE WIND. SO LOCATIONS ALONG THE I-95 CORRIDOR AS WELL AS ROUTE 3 IN PLYMOUTH COULD BE IMPACTED WITH A QUICK DUSTING OF SNOW AS WELL AS REDUCED VSBYS...ESP DURING THE EVENING COMMUTE AND INTO LATE EVENING HOURS. MOTORIST SHOULD USE CAUTION THIS EVENING WHEN TRAVELING. AS THE SYSTEM PULLS AWAY...A FEW LINGERING SNOW SHOWERS WILL CONTINUE BEFORE ENDING AROUND 1-3 AM. THE OTHER MAIN FOCUS IS THE STRONG TO DAMAGING WINDS. STRONGEST WINDS WILL OCCUR AFTER MIDNIGHT INTO SATURDAY MORNING. AS LAPSE RATES CONTINUE TO INCREASE ANTICIPATE LOCATIONS THE EASTERN HALF OF SOUTHERN NEW ENGLAND TO SEE NEAR 25-35 MPH GUSTS. HOWEVER STRONGEST GUSTS WILL OCCUR OVER THE CAPE AND THE ISLANDS...WHICH IS CLOSER TO THE STRONG JET. THE WIND ADVISORY WILL CONTINUE AS GUSTS BETWEEN 40- 50 MPH ARE POSSIBLE. THIS COULD BRING DOWN TREE LIMBS AND WIRES. THERE ARE A FEW COASTAL CONCERNS...PLEASE REACH THE COASTAL FLOODING SECTION BELOW. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... SATURDAY... SURFACE HIGH PRESSURE WILL FILL IN BEHIND DEPARTING OFFSHORE LOW FOR SATURDAY. STRONG WINDS GUSTS OVER THE CAPE/ISLAND AND THE WATERS WILL BEGIN TO SUBSIDE AS PRESSURE GRADIENT WEAKENS THROUGHOUT THE DAY. UPPER LEVEL LOW TURNS A BIT MORE PROGRESSIVE WITH A SHORTWAVE QUICKLY PASSING BY DURING THE DAY. THIS WAVE WILL RESULT IN AN INCREASE IN MID AND HIGH LEVEL CLOUDS. DRY AIR IN THE LOW LEVELS WILL KEEP SATURDAY DRY. TEMPERATURES WILL BE MORE SEASONABLE WITH DAY TIME HIGHS IN THE LOW 40S TO UPPER 30S. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... BIG PICTURE... RIDGE-WEST/TROUGH-EAST PATTERN OVER THE WEEKEND FLATTENS EARLY NEXT WEEK. CONTOUR HEIGHTS ARE FORECAST TO BUILD WEST TO EAST AS THE FLOW FLATTENS. THIS SUGGESTS A WARMING TREND FOR MUCH OF NEXT WEEK. SHORTWAVE SCALE SHOWS ONE SHORTWAVE MOVING THROUGH NEW ENGLAND SUNDAY...EVENTUALLY FORMING A CLOSED LOW WELL OUT TO SEA. A SECOND SHORTWAVE MOVES ALONG THE CANADIAN BORDER MONDAY. UPPER RIDGE THEN BUILDS OVER THE EASTERN USA. A THIRD SHORTWAVE RACES ACROSS CANADA THIS WEEK AND CROSSES NORTHERN NEW ENGLAND WEDNESDAY-THURSDAY... FLATTENING THE NEW ENGLAND PORTION OF THE UPPER RIDGE. THE DAILIES... SATURDAY NIGHT-SUNDAY... ALBERTA CLIPPER FROM THE GREAT LAKES MOVES TO THE MID ATLANTIC COAST AND THEN SWINGS OFFSHORE AND WELL SOUTH OF NEW ENGLAND. THIS WILL BE TOO FAR SOUTH TO DIRECTLY AFFECT OUR AREA. HOWEVER THE SUPPORTING UPPER SHORTWAVE WILL MOVE OVER US. SUFFICIENT COLD AIR AT THE CORE OF THE TROUGH TO INCREASE INSTABILITY...TOTALS ARE FORECAST TO CLIMB INTO THE MID AND UPPER 40S WHICH SUGGESTS SOME POTENTIAL FOR CONVECTION. LIKELY NOT ANY THUNDER...BUT A FEW SNOW SHOWERS ARE POSSIBLE. THIS WILL THEN MOVE OFF WITH CLEARING FROM WEST TO EAST SUNDAY AFTERNOON. MIXING WILL REACH TO 850 MB SUNDAY WITH TEMPS AT THAT LEVEL SUPPORTING MAX SFC TEMPS IN THE LOWER 40S. MONDAY THROUGH WEDNESDAY... EXPECT A PERIOD OF QUIET WEATHER AS HIGH PRESSURE BUILDS TO OUR SOUTH AT THE SURFACE AND ALOFT. A SHORTWAVE PASSING ACROSS QUEBEC WILL PULL A WEAK WARM FRONT THROUGH NEW ENGLAND ON MONDAY...BUT MOST OF THE DYNAMIC SUPPORT WILL BE ALONG THE CANADIAN BORDER. SO WE MAY SEE MID AND HIGH CLOUDS BUT NO PCPN. PRESSURE GRADIENT WILL TIGHTEN BEHIND THE WARM FRONT WITH SUPPORT FOR WINDS GUSTING 20-25 KNOTS ALONG THE COASTAL PLAIN. THE MAIN EVENT FOR THE EARLY WEEK WILL BE THE WARMING TEMPS. WARM ADVECTION ALOFT WILL SHRINK THE DEPTH OF THE MIXED LAYER...BUT MIXING EVEN TO 925 MB WOULD SUPPORT MID 60S TUESDAY AND UPPER 60S/LOWER 70S WEDNESDAY. THIS IS A LITTLE HIGHER THAN GUIDANCE...SO WE BUMPED GUIDANCE VALUES UP 2-3 DEGREES. THURSDAY-FRIDAY... ANOTHER SHORTWAVE CROSSING EASTERN CANADA WILL PUSH A COLD FRONT SOUTH THROUGH NEW ENGLAND. THIS FRONT SHOULD CROSS OUR AREA EITHER WEDNESDAY NIGHT PER THE GFS OR THURSDAY MIDDAY-AFTERNOON PER THE ECMWF. THIS COLD FRONT MAY BRING A CHANCE OF SHOWERS. HIGH PRESSURE THEN BUILDS DRIER COOLER WEATHER FOR FRIDAY. CONFIDENCE IS LIMITED BY THE OBVIOUS TIMING UNCERTAINTY WITH THE COLD FRONT. BUT THE TREND LOOKS FINE AT THIS TIME. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/... TONIGHT...HIGH CONFIDENCE. VFR CIGS ACROSS THE CONNECTICUT VALLEY WITH MVFR CIGS FARTHER EAST AND IFR ALONG THE EAST COAST AND CAPE/ISLANDS. EXPECT SNOW TO CONTINUE EARLY TONIGHT AND THEN TAPER OFF 02-05Z. OCEAN EFFECT SNOW SHOWERS AFFECTING THE NORTH SHORE AND PLYMOUTH COAST SHOULD DIMINISH AS WINDS TURN NORTH. EXPECT CLEARING SKIES WEST TO EAST AFTER MIDNIGHT. EXPECT 20-30 KT WIND GUSTS AROUND I-95 WITH CAPE AND ISLANDS SEEING GUSTS NEAR 40-45 KTS BETWEEN 03-09Z. SATURDAY...HIGH CONFIDENCE. BRISK NW WINDS INTO THE MORNING FOR THE CAPE AND ISLANDS. OTHERWISE LIGHT OVERALL AND VARIABLE AS HIGH PRESSURE BUILDS. VFR WITH A BRIEF PERIOD OF SKC WITH INCREASING MID-HIGH CLOUDS IN THE AFTERNOON. KBOS TERMINAL...HIGH CONFIDENCE. IFR CONDITIONS EARLY TONIGHT. SNOW SHOWERS AFFECTING THE NORTH SHORE WILL CONTINUE TO MOVE SOUTHWEST THROUGH OR NEAR BOSTON THROUGH 03-04Z AND THEN DIMINISH. LOWER CONFIDENCE ON EXACT VSBYS BUT ANTICIPATE OCCASIONAL CONDITIONS AROUND 1SM. CONDITIONS IMPROVING TO VFR BY 07Z. KBDL TERMINAL...HIGH CONFIDENCE. VFR CONDITIONS. OUTLOOK /SATURDAY NIGHT THROUGH WEDNESDAY/...MODERATE CONFIDENCE. VFR FOR MOST OF THE PERIOD. THERE IS A LOW-MODERATE CHANCE OF MVFR/IFR CIGS/VSBYS IN SNOW SHOWERS SUNDAY ESPECIALLY ALONG THE SOUTH COAST. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/... TONIGHT... OFFSHORE COASTAL LOW DEEPENS RAPIDLY WHILE PASSING SE OF THE 40N/70W BENCHMARK. NE WINDS INCREASE WITH GUSTS UP TO 50 KTS POSSIBLE DURING PASSAGE ESPECIALLY OVER THE SE WATERS. GALE AND STORM FORCE WARNINGS ARE IN EFFECT. WAVES BUILDING UPWARDS OF AROUND 15 FEET. SNOW/RAIN OUTCOMES ESPECIALLY S/SE WILL RESULT IN VISIBILITY IMPACTS. SATURDAY... N/NW WINDS REMAINING BLUSTERY DURING THE FIRST HALF OF THE PERIOD BEFORE DECREASING DURING THE DAY. COLDER AIR BUILDING S LENDS A DEFINITE RISK OF FREEZING SPRAY AS WAVE HEIGHTS INITIALLY 10 TO 15 FEET GRADUALLY DIMINISH. OUTLOOK /SATURDAY NIGHT THROUGH WEDNESDAY/...MODERATE CONFIDENCE... SATURDAY NIGHT-SUNDAY...LOW PRESSURE PASSES WELL SOUTH OF THE WATERS. HIGH PRESSURE BUILDS OVER THE WATERS. WINDS WILL REMAIN LIGHT THROUGH SUNDAY. LINGERING 5 FOOT SEAS ON THE OUTER WATERS SHOULD SUBSIDE. A SMALL CRAFT ADVISORY MAY BE NEEDED ON THOSE OUTER WATERS SATURDAY NIGHT. MONDAY THROUGH WEDNESDAY... WEST TO SOUTHWEST FLOW THROUGH THE PERIOD WITH WINDS GUSTING NEAR 25 KNOTS MONDAY AFTER A WARM FRONT MOVES ACROSS THE WATER. SEAS REMAIN LESS THAN 5 FEET THROUGH THE PERIOD...EXCEPT MAY BE AREAS AROUND 5 FEET ON THE OUTER WATERS WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED MONDAY FOR THE WINDS AND ON THE OUTER WATERS WEDNESDAY FOR THE SEAS. && .TIDES/COASTAL FLOODING... ONSHORE WIND AND SEAS INCREASE THIS EVENING BUT NOT ENOUGH TO HAVE ANY SIGNIFICANT COASTAL IMPACT AROUND THE TIME OF THE EVENING HIGH TIDE...WHICH IS PARTICULARLY LOW ASTRONOMICALLY. THE SATURDAY MORNING HIGH TIDE IS HIGHER ASTRONOMICALLY BUT STILL NOT ALL THAT HIGH AS ASTRONOMICAL TIDES GO. NEVERTHELESS...THERE WILL BE ENOUGH SURGE AND RESIDUE SWELLS TO POSSIBLY CAUSE SOME EROSION ALONG THE OUTER CAPE AND THE EAST SIDE OF NANTUCKET. ALTHOUGH DIMINISHING IN SPEED...THERE WILL PROBABLY BE ENOUGH NORTHERLY FLOW TO KEEP A SURGE NEAR OR SLIGHTLY ABOVE 1.5 FEET IN NANTUCKET HARBOR. THIS MAY BE JUST ENOUGH TO CAUSE SOME VERY MINOR FLOODING OF THE MOST VULNERABLE LOCATIONS SUCH AS EASY STREET. THE ESTOFS GUIDANCE LOOKED MORE REASONABLE THAN THE ETSS THROUGH THIS EVENING GIVEN THE SYNOPTIC PATTERN. HOWEVER...THE ETSS GUIDANCE LOOKED TO BE SUPERIOR FOR OVERNIGHT AND SATURDAY. THE PRIOR SATURDAY MORNING SURGE FORECAST STILL LOOKED GOOD FROM THIS SHIFT/S PERSPECTIVE WITH ONLY VERY MINOR ADJUSTMENTS MADE ALONG PORTIONS OF THE CAPE COD NORTH AND EAST FACING SHORELINES. WILL COVER THE POCKETS OF MINOR COASTAL FLOODING AND EROSION DURING THE SATURDAY MORNING HIGH TIDE WITH A STATEMENT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ006- 007. WIND ADVISORY UNTIL 7 AM EST SATURDAY FOR MAZ022>024. WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR MAZ024. RI...NONE. MARINE...GALE WARNING UNTIL 10 AM EST SATURDAY FOR ANZ231-232. GALE WARNING UNTIL 7 AM EST SATURDAY FOR ANZ233>235-237-251. GALE WARNING UNTIL 4 AM EST SATURDAY FOR ANZ230-236. GALE WARNING UNTIL 1 PM EST SATURDAY FOR ANZ250-256. STORM WARNING UNTIL 4 AM EST SATURDAY FOR ANZ254-255. && $$ SYNOPSIS...WTB/DUNTEN NEAR TERM...WTB/DUNTEN SHORT TERM...DUNTEN LONG TERM...WTB AVIATION...WTB/DUNTEN MARINE...WTB/DUNTEN TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
202 AM EST THU MAR 3 2016 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE REGION TONIGHT WITH GRADUALLY DIMINISHING WINDS AND CLEARING SKIES. DRY WEATHER IS EXPECTED ON THURSDAY WITH A MOSTLY SUNNY SKY AND COOL TEMPERATURES. A STORM SYSTEM PASSING TO THE SOUTH WILL ALLOW FOR SOME POSSIBLE LIGHT SNOW TO AREAS SOUTH OF ALBANY ON THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 200 AM EST...QUICK UPDATE TO ACCOUNT FOR SOME SNOW SQUALLS THAT HAVE DEVELOPED IN PORTIONS OF THE MOHAWK VALLEY AND SCHOHARIE VALLEY. A COMBINATION OF THE LINGERING UPPER-LEVEL TROUGH...TRAPPED LOW-LEVEL MOISTURE AND STEEP LOW-LEVEL LAPSE RATES ARE LIKELY PROVIDING THE FORCING MECHANISMS FOR THESE SQUALLS. HAVE ISSUED A SPECIAL WEATHER STATEMENT TO ADDRESS A QUICK INCH OF ACCUMULATION IN LESS THAN AN HOUR AS WELL FOR LOCALIZED HAZARDOUS TRAVEL CONDITIONS ALONG INTERSTATE 88 WITH NEAR ZERO VISIBILITY UNDERNEATH THE SQUALL. MESOSCALE GUIDANCE INCLUDING THE HRRR HAS NOT CAPTURED THIS ACTIVITY WELL IF AT ALL...AND HAVE ADJUSTED THE GRIDS OVER THE NEXT FEW HOURS USING A NOWCAST APPROACH. THESE SNOW SQUALLS AND SHOWERS LOOK TO CONTINUE FOR AT LEAST BEFORE ENDING. ACROSS THE REST OF THE REGION...IT WILL BE DRY WITH SKIES BECOMING MOSTLY CLEAR BY DAYBREAK. WEST TO NORTHWEST WINDS CONTINUE TO SLOWLY SUBSIDE ACROSS THE REGION...BUT A FEW SPORADIC GUSTS AROUND 25 MPH WILL BE POSSIBLE FOR THE NEXT FEW HOURS ESPECIALLY DOWN THE MOHAWK VALLEY INTO PORTIONS OF THE CAPITAL REGION AND BERKSHIRES. AS THE HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION...WINDS TOWARDS DAYBREAK SHOULD FEATURE GUSTS LESS THAN 15 MPH FOR MOST AREAS. OVERNIGHT LOWS WILL BE CHILLY...WITH TEENS FOR MOST AREAS. SOME SINGLE DIGITS WILL BE POSSIBLE FOR THE ADIRONDACKS...WESTERN MOHAWK VALLEY...LAKE GEORGE AREA...SOUTHERN VT...AND THE EASTERN CATSKILLS. ACROSS FAR NORTHERN HERKIMER AND HAMILTON COUNTIES...LOWS AROUND 0 TO 5 BELOW ZERO WILL BE POSSIBLE. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/... DRY AND QUIET WEATHER IS EXPECTED ON THURSDAY WILL A MOSTLY SUNNY SKY THANKS TO NEARBY HIGH PRESSURE. IT WILL BE COOLER THAN NORMAL...WITH HIGHS IN THE UPPER TEENS TO UPPER 20S ACROSS MUCH OF THE AREA...ALTHOUGH PARTS OF THE MID HUDSON VALLEY AND NW CT SHOULD RISE INTO THE LOW TO MID 30S THANKS TO PLENTY OF SUNSHINE AND A DOWNSLOPING BREEZE. SOME CLOUDS WILL INCREASE ON THURSDAY NIGHT AS AN UPPER LEVEL SHORTWAVE STARTS TO APPROACH FROM THE WEST. SFC LOW PRESSURE WILL BE TRACKING ACROSS THE DEEP SOUTH AND TENNESSEE VALLEY TOWARDS THE MID ATLANTIC COAST FOR THURSDAY NIGHT INTO FRIDAY. THIS SYSTEM WILL GENERALLY STAY SOUTH OF THE AREA. HOWEVER...IT COULD BE CLOSE ENOUGH TO BRUSH FAR SOUTHERN AREAS WITH SOME LIGHT SNOW FOR LATE THURSDAY NIGHT INTO FRIDAY MORNING. A COATING TO AN INCH IS POSSIBLE FOR PARTS OF THE CATSKILLS...MID HUDSON VALLEY AND NW CT. PARTS OF THE CAPITAL REGION MAY SEE SOME SNOWFLAKES AT SOME POINT...BUT LITTLE TO NO ACCUMULATION IS EXPECTED FROM ALBANY NORTHWARD. OTHERWISE...MOSTLY CLOUDY AND CHILLY CONDITIONS WILL CONTINUE. LOWS ON THURSDAY NIGHT WILL BE IN THE SINGLE DIGITS AND TEENS...WITH HIGHS ON FRIDAY INTO THE 20S TO LOW 30S. BEHIND THE DEPARTING SHORTWAVE...MAINLY DRY AND QUIET WEATHER WILL RETURN FOR FRI NIGHT INTO SATURDAY. SKIES WILL BE PARTLY TO MOSTLY CLEAR. TEMPS WILL BE IN THE SINGLE DIGITS AND TEENS ONCE AGAIN FOR FRI NIGHT...WITH HIGHS IN THE 30S FOR MOST AREAS ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE BUILDS INTO THE REGION SATURDAY NIGHT AND SUNDAY WITH A WEAK WAVE OF LOW PRESSURE TRACKING WELL SOUTH AND EAST OF OUR REGION. SOME ISOLATED RAIN/SNOW SHOWERS ARE POSSIBLE IN THE MID HUDSON VALLEY AND NW CT SATURDAY NIGHT INTO SUNDAY ON THE FAR NORTHWEST PERIPHERY OF THIS WAVE OF LOW PRESSURE. HIGHS SUNDAY IN THE LOWER TO MID 40S...SOME MID TO UPPER 30S IN NORTHERN AREAS. HIGH PRESSURE BUILDS EAST AND OFFSHORE SUNDAY NIGHT AND MONDAY WITH A SURGE OF WARM ADVECTION AND RAPIDLY WARMING BOUNDARY LAYER TEMPERATURES. SOME ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS IN NORTHERN AREAS MONDAY AS THE BOUNDARY LAYER THERMAL GRADIENT TIGHTENS UP THERE ASSOCIATED WITH THE WARM FRONT DEVELOPING TO OUR NORTH. THE FORCING SHOULD SUPPORT SCATTERED TO ISOLATED SHOWERS MONDAY THROUGH WEDNESDAY IN NORTHERN AREAS BUT ONLY ISOLATED TO SCATTERED BECAUSE OF LIMITED MOISTURE. BOUNDARY LAYER TEMPERATURES WARM CONSIDERABLY MONDAY THROUGH WEDNESDAY AS UPPER RIDGING AMPLIFIES OVER THE EASTERN U.S. HIGHS MONDAY IN THE 40S TO AROUND 50. HIGHS TUESDAY IN THE MID TO UPPER 50S...BUT AROUND 50 NORTHERN AREAS. HIGHS WEDNESDAY POTENTIALLY INTO THE 60S WITH UPPER 50S NORTHERN AREAS. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... MAINLY VFR THROUGH THE TAF PERIOD ENDING AT 06Z FRIDAY. THERE STILL COULD BE SOME MVFR CIGS HANGING AROUND AT KPSF THROUGH 10Z...SO WE ASSIGNED A TEMPO GROUP THERE. OTHERWISE THERE WILL SKC-SCT040 TODAY WITH UNLIMITED VISIBILITY. THE GUSTY NW WINDS HAVE ABATED EXCEPT AT KPSF...AND BY 10Z ALL THE TAF SITES SHOULD HAVE WINDS AVERAGING AROUND 10KTS (OR A LITTLE LESS) FROM NW DIRECTION WITH FEW IF ANY SIGNIFICANT GUSTS. THROUGH 10Z...WE STILL HAVE GUSTS TO 20KTS AT KPSF. LOOK FOR A NW WIND TO CONTINUE AROUND 10KTS THROUGHOUT TODAY. A STORM IN THE SOUTHERN STREAM LOOKS TO STAY MAINLY TO OUR SOUTH. HOWEVER IT WILL SPREAD HIGH CLOUDS OUR WAY DURING THE EVENING PEAK AND PERHAPS BRING A LITTLE LIGHT SNOW OR FLURRIES TO THE KPOU BY THE END OF THE 06Z TAF CYCLE. FOR NOW...WENT WITH JUST VCSH BY 05Z AT KPOU AND WILL FINE TUNE ANY PROJECTED SNOWFALL THAT COULD LOWER CONDITIONS TO MVFR OR IFR WITH THE 12Z TAF ISSUANCE. OUTLOOK... THURSDAY NIGHT THROUGH FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SN. FRIDAY NIGHT THROUGH MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDROLOGIC CONCERNS OVER THE NEXT SEVERAL DAYS. MAINLY DRY WEATHER IS ANTICIPATED FOR THE REMAINDER OF THE WEEK AND THROUGH THE WEEKEND. THERE IS THE POSSIBILITY OF SOME LIGHT SNOW FOR FAR SOUTHERN AREAS FOR THURSDAY NIGHT INTO FRIDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY BE LESS THAN A TENTH OF AN INCH...WHICH WILL HAVE LITTLE TO NO HYDROLOGIC IMPACT. AS A RESULT OF THE DRY AND RELATIVELY COLD WEATHER...RIVER AND STREAMS LEVELS WILL CONTINUE TO EITHER SLOWLY RECEDE OR HOLD STEADY. THE COLD WEATHER OVER THE NEXT FEW DAYS MAY ALLOW FOR SOME ICE TO BUILD...BUT MILDER WEATHER IS ANTICIPATED BY THE END OF THE WEEKEND AND INTO EARLY NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS/IRL NEAR TERM...IRL SHORT TERM...FRUGIS LONG TERM...NAS AVIATION...HWJIV HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS KEY WEST FL
1013 PM EST FRI MAR 4 2016 .DISCUSSION... .CURRENTLY...SKIES ARE PARTLY CLOUDY WITH TEMPERATURES IN THE LOWER 70S ALONG KEYS COMMUNITIES. MEANWHILE...LOCAL RADARS ARE NOT DETECTING ANY PRECIPITATION ECHOES IN OUR REGION. OTHERWISE...OUR EVENING SOUNDING REVEALS LIMITED MOISTURE BELOW 850 MB...AS WELL AS ABOVE 400 MB. A SHALLOW NORTHWEST TO NORTH FLOW TURNS WEST NORTHWEST AND INCREASES APPRECIABLY ABOVE 800 MB. && .SHORT TERM (REST OF TONIGHT)...A SNAKE LIKE TROUGH/WEAK COLD FRONT DRAPED ACROSS SOUTH CENTRAL FLORIDA AND THE ADJACENT ATLANTIC AND GULF WATERS WILL SAG SOUTHWARD...WHILE AN EXPANSIVE AREA OF HIGH PRESSURE BRIDGES ACROSS THE FRONTAL BOUNDARY. GIVEN THE LOW LEVEL FLOW VEERING TO NORTHEAST AND INCREASING...BOTH THE HRRR AND LOCAL WRF MODELS INDICATE ISOLATED SHOWERS APPROACHING THE UPPER KEYS AT AROUND DAYBREAK. MEANWHILE...A LIGHT...ALBEIT STEADY MOSTLY NORTH WIND BLOWING ACROSS WARM GULF AND BAY WATERS SHOULD KEEP LOW TEMPERATURES NEAR 70 DEGREES. WITH NICKLE POPS IN THE GRIDS AND TEMPERATURES IN LINE...SEE NO REASON FOR AN ADJUSTMENT. && .MARINE...NORTHWEST TO NORTH WINDS SHOULD TURN NORTH NORTHEAST AND INCREASE INTO THE 10 TO 15 KNOT RANGE OVERNIGHT. OTHERWISE...ISOLATED SHOWERS WILL BE RETAINED ON THE FLORIDA STRAITS. && .AVIATION...A WEAK FRONT WILL PUSH THROUGH THE EYW AND MTH TERMINALS OVERNIGHT. NORTHERLY CROSSWIND GUSTS WILL TEMPORARILY INCREASE TO 15 KNOTS AS THIS FRONT REACHES THE TERMINALS BETWEEN 06 AND 12Z. FORECAST SOUNDINGS INDICATE A STRATUS LAYER AROUND 010 WILL ACCOMPANY THE WEAK SURGE IN NORTHERLY WINDS. ALTHOUGH GUIDANCE SEEMS SURE OF THIS SCENARIO...THE PHYSICAL MECHANISMS DO NOT SUPPORT STRATUS CIGS. THEREFORE...WE HAVE ADVERTISED ONLY A BRIEF MVFR CIG AT BOTH TERMINALS OUT OF RESPECT FOR THE CONSENSUS AMONG THE MODEL GUIDANCE. && .CLIMATE... IN 1980...THE DAILY RECORD LOW TEMPERATURE OF 49F WAS RECORDED IN KEY WEST. TEMPERATURE RECORDS HAVE BEEN KEPT SINCE 1872 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...NONE. GM...NONE. && $$ PUBLIC/MARINE.........APA AVIATION/NOWCASTS.....CR DATA COLLECTION.......EV VISIT US ON THE WEB AT WEATHER.GOV/KEY FOLLOW US ON FACEBOOK AND TWITTER AT... WWW.FACEBOOK.COM/NWSKEYWEST WWW.TWITTER.COM/NWSKEYWEST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
547 PM CST FRI MAR 4 2016 .SHORT TERM... 200 PM CST THROUGH SATURDAY... ALL REMAINS ON TRACK FOR A QUICK SHOT OF SNOW TONIGHT ESPECIALLY ALONG AND NORTH OF I-80. THE PRIMARY IMPACT LOOKS TO BE SHARPLY REDUCED VISIBILITY FOLLOWED BY A QUICK COATING OF SNOW ON SOME PAVED SURFACES. THE CENTER OF THE MAIN CLIPPER SHORT WAVE IS IN WESTERN MINNESOTA EARLY THIS AFTERNOON. AS ITS DRIVING JET SPREAD INTO OUR REGION THIS EVENING...HEIGHT FALLS AND ASSOCIATED LIFT WILL MAXIMIZE OVER WISCONSIN AND NORTHERN ILLINOIS. STEEPER MID-LEVEL LAPSE RATES OBSERVED ON UPSTREAM MORNING SOUNDINGS AND EARLY AFTERNOON AIRCRAFT DATA FROM OMAHA WILL CONTINUE TO SPREAD EASTWARD WITHIN THE WARM ADVECTION ZONE SOUTH OF THE VORTICITY CENTER. AS THIS CATCHES UP TO THE LIFT AND SATURATION...THE AREA OF PRECIPITATION PRESENTLY IN MN/NORTHERN IA SHOULD SHOW SOUTHEAST EXPANSION AND PROBABLY INTENSIFICATION DURING THE EARLY TO MID EVENING WHICH CORRELATES TO WHEN IT IS OVER THE AREA. HAVE ONLY MADE FURTHER REFINEMENTS TO HOURLY TIMING OF PRECIPITATION WHICH LOOKS TO BE MAINLY WET SNOW THIS EVENING ESPECIALLY IN NORTHEAST ILLINOIS AND FAR NORTHWEST INDIANA. ONSET OF PRECIPITATION COULD BRIEFLY BE A MIX WITH RAIN...AND TOWARD I-39 IT COULD REMAIN A MIX OR EVEN JUST RAIN SHOWERS THIS EVENING. BECAUSE OF THE QUICK MOVEMENT OF THE FORCING AND FOCUS...THE SNOWFALL LOOKS TO LAST TWO HOURS OR LESS IN MOST LOCATIONS...WITH THE MODERATE INTENSITY EVEN A SHORTER SPAN. CONVECTIVE ALLOWING MODELS CONTINUE TO SUPPORT THIS IN THEIR REFLECTIVITY... VISIBILITY...AND HOURLY SNOWFALL FORECASTS. THE PRIMARY TIMING FOR THE CHICAGO METRO LOOKS TO BE BETWEEN 9 PM AND MIDNIGHT. WETTER QUALITY OF THE SNOW AND TEMPERATURES OF 31-35 SHOULD LIMIT MUCH FOR ACCUMULATION ON PAVEMENT...THOUGH GRASSY SURFACES WILL PROBABLY SEE A QUICK COAT IN NORTH OF I-80 COMMUNITIES. SOUTH OF I-80 MORE LIMITED TIME AND FORCING FOR SATURATION WILL PROVIDE MORE VIRGA /RADAR ECHOES NOT REACHING THE GROUND/ THAN PRECIPITATION...SO NO ACCUMULATION FORECAST. LOSS OF ICE HAPPENS RAPIDLY BY MIDNIGHT WHICH MAKES SENSE GIVEN UPSTREAM SATELLITE TRENDS. LOW-LEVEL SATURATION AND LIFT STILL ARE PROVIDED ON RAP AND NAM SOUNDINGS EVEN THROUGH DAYBREAK. SO CONTINUE FORECAST DRIZZLE CHANCES. THE TEMPERATURES SHOULD BE INCHING UP LATE TONIGHT SO NOT TOO CONCERNED ON FREEZING DRIZZLE BUT DO INDICATE THE BRIEF POSSIBILITY IN THE FORECAST WHERE OUR DETERMINISTIC TEMPERATURE FORECASTS OUR 30-32 FOR A FEW HOURS. HAVE TRENDED MORE CLOUDY FOR SATURDAY ESPECIALLY FOR THE EASTERN HALF OF THE CWA. HAVE DONE SO AS THE CLIPPER BROADENS TO OUR NORTHEAST AND KEEPS CYCLONIC FLOW ACROSS THE REGION. CLEARING SHOULD OCCUR FROM WEST-TO-EAST SOMETIME IN THE AFTERNOON THROUGH IT COULD TAKE UNTIL EARLY SATURDAY EVENING. HAVE HIGHS AROUND NORMAL WITH 40 EAST TO 45 WEST. MTF && .LONG TERM... 213 PM CST SATURDAY NIGHT THROUGH FRIDAY... A SHIFT TOWARDS A WARM AND ACTIVE SPRING-LIKE PATTERN IS EXPECTED TO OCCUR LATE IN THE WEEKEND INTO EARLY NEXT WEEK BRINGING UNSEASONABLY WARM CONDITIONS AS WELL AS PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS. BY SATURDAY NIGHT...SURFACE RIDGE IS EXPECTED TO BUILD ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA BRINGING QUIET CONDITIONS BUT FAVORABLE FOR RADIATIONAL COOLING...AND WHAT LOOKS TO BE OUR COLDEST NIGHT OVER THE UPCOMING WEEK. FORECASTING LOWS IN THE 20S ACROSS THE FORECAST AREA...HOWEVER WOULDNT BE SURPRISED TO SEE A FEW OF THE TYPICAL COLD SPOTS DIPPING INTO THE TEENS. HIGH PRESSURE WILL SHIFT TO OUR EAST SUNDAY WITH SOUTHERLY FLOW OVERSPREADING THE REGION. THE HIGH IS PROGGED TO BECOME ANCHORED JUST OFF THE SOUTHEASTERN ATLANTIC COAST WHILE UPPER LEVEL PATTERN CONTINUES TO AMPLIFY WITH STRONG EAST COAST UPPER RIDGE DEVELOPING BY THE MIDDLE OF NEXT WEEK AND DEEP TROUGHING DEVELOPING ACROSS THE WESTERN CONUS. LOCALLY THIS WILL MEAN A WARMING TREND THROUGH TUESDAY WHEN TEMPERATURES ARE FORECAST TO RISE INTO THE MID 60S ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. AS DEEP TROUGHING MOVES OVER THE MID SECTION OF THE COUNTRY...WE WILL SET THE STAGE FOR SEVERE WEATHER TO OCCUR ACROSS PORTIONS OF THE PLAINS AND MIDWEST EARLY NEXT WEEK AND WHILE ITS TOO EARLY TO HONE IN ON SPECIFICS FOR SEVERE WEATHER...MODELS DO SHOW INSTABILITY BUILDING THIS FAR NORTH SO A THUNDERSTORM MENTION IS INCLUDED IN THE FORECAST FOR NOW...MAINLY ON TUESDAY FOR OUR AREA. UPPER LOW EXPECTED TO CUT OFF ACROSS THE DEEP SOUTH AROUND MIDWEEK AND EVENTUALLY MEANDER ACROSS THE MIDWEST LATE IN THE WEEK OR NEXT WEEKEND. DETAILS REMAIN UNCLEAR AT THIS POINT BUT IT DOES APPEAR WE WILL GENERALLY STAY IN A WARMER AND WETTER PATTERN LATE IN THE WEEK INTO NEXT WEEKEND. DEUBELBEISS && .AVIATION... FOR THE 00Z TAFS... MAIN CONCERN FOR THE TAFS CONTINUES TO BE WITH A COUPLE HOUR PERIOD SNOW THIS EVENING WITH BRIEF LIFR VISIBILITY. PRECIPITATION COULD START WITH A BRIEF MIX OF RAIN/SNOW. TEMPS HANG NEAR 32 THEN RISE A BIT AFTER MIDNIGHT WITH DRIZZLE AND THE POTENTIAL FOR IFR CIGS...FARILY HIGH PROBABILITY OF MVFR CIGS WHICH LINGER A GOOD PORTION OF THE DAY SATURDAY. AREA OF LOW PRESSURE WAS OVER MINNESOTA LATE THIS AFTERNOON...WITH A COMPACT BUT POTENT MID-LEVEL DISTURBANCE TRACKING SOUTHEAST ACROSS THE REGION. A BAND OF PRECIPITATION ABOUT 100 MILES WIDE HAS DEVELOPED AHEAD OF THE MID-LEVEL TROUGH...AND WILL BRING A PERIOD OF MODERATE...POSSIBLY BRIEFLY HEAVY...PERIOD OF SNOW TO THE AREA. START TIME IS A LITTLE TRICKIER THAN THE END TIME...AS RADAR ECHOES PRESENT WITH LITTLE PRECIP REACHING THE GROUND INITIALLY AS ATMOSPHERE SATURATES FROM TOP-DOWN...BUT IT APPEARS BY 0230-300Z SNOW SHOULD BE REACHING THE GROUND INTO ORD/MDW. TRAILING EDGE MORE SOLIDLY DEFINED AND IS EXPECTED TO REACH ORD/MDW AROUND 06Z/MIDNIGHT. UPSTREAM OBS INDICATE LIFR VSBY AND IFR CIGS WITH HEAVIEST SNOW. DESPITE INTENSITY...SHORT DURATION LOOKS TO PRODUCE AMOUNTS ONLY OF UP TO 1 INCH. LOW LEVEL MOISTURE THEN WRAPS AROUND FROM THE NORTHWEST OVERNIGHT WITH SOME DRIZZLE LIKELY. TEMPS AROUND FREEZING INITIALLY SHOULD RISE ABOVE FREEZING OVERNIGHT WITH LITTLE IMPACT. BREEZY NORTHWEST WINDS GUSTING 20 KT DEVELOP SATURDAY. MVFR CIGS LIKELY TO LINGER BEFORE ERODING LATE IN THE DAY. RATZER && .MARINE... 213 PM CST A CLIPPER LIKE SNOW SYSTEM WILL DROP ACROSS THE UPPER MIDWEST AND WESTERN GREAT LAKES REGION TODAY WITH MODERATE SOUTHERLY FLOW OF 20 TO 25 KT EXPECTED AHEAD OF THIS SYSTEM THIS EVENING AND TONIGHT. THE LOW WILL CROSS OVER THE SOUTHERN HALF OF LAKE MICHIGAN ON SATURDAY WITH WINDS TURNING NORTHERLY BEHIND...THEN DIMINISHING AS HIGH PRESSURE BEGINS TO BUILD OVERHEAD FOR SATURDAY NIGHT. THE HIGH WILL CONTINUE TO THE SOUTHEAST STATES AND EVENTUALLY SET UP NEAR BERMUDA WHERE IT WILL REMAIN ANCHORED MUCH OF THE UPCOMING WEEK WHICH WILL HELP DRIVE A MAJOR PATTERN CHANGE ACROSS THE REGION. LOW PRESSURE DEVELOPS OVER THE PLAINS SUNDAY INTO EARLY NEXT WEEK WITH SOUTHERLY FLOW RAMPING BACK UP AGAIN TO AROUND 30 KT SUNDAY. MODERATE SOUTHERLY FLOW OF 20 TO 25 AND OCCASIONALLY 30 KT WILL CONTINUE THROUGH TUESDAY HELPING SPREAD AN UNSEASONABLY WARM AND MOIST AIRMASS INTO THE GREAT LAKES. THE HIGH DEWPOINTS ARE EXPECTED TO RESULT IN AREAS OF FOG DEVELOPING OVER THE LAKE. ALSO CANNOT RULE OUT SOME THUNDERSTORMS...PARTICULARLY ON TUESDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
301 PM CST THU MAR 3 2016 .SHORT TERM...(Tonight) ISSUED AT 301 PM CST THU MAR 3 2016 19z/1pm surface analysis shows a 1010mb low over Arkansas, with a trough axis extending northward into central Illinois. Light rain continues to fall in the vicinity of the trough, but has now pushed mainly east of the Illinois River. This feature is progged to be located along the I-57 corridor by 00z, so am expecting some light precip to linger across the E/SE CWA into the evening hours. As winds become northerly on the back side of the trough, the atmosphere will cool sufficiently to support a light rain/snow mix. Based on latest trends and HRRR forecast, have included low chance PoPs along/east of a Bloomington to Flora line this evening. Will mention rain or snow north of the I-70 corridor: however, no snow accumulation is expected. Once the trough pushes off to the east, cloudy and cool conditions will prevail for the remainder of the night with low temperatures dropping into the upper 20s and lower 30s. && .LONG TERM...(Friday through Thursday) ISSUED AT 301 PM CST THU MAR 3 2016 High pressure will move quickly across the state Friday with partly sunny skies for the late morning and early afternoon and slightly milder temperatures. Another storm system passing across Wisconsin Friday night, with a trailing cold front and shortwave passing through central IL will increase mid and high clouds and southerly winds late in the day Friday, and bring at least a slight chance for precipitation or drizzle overnight. There is some question about precipitation type as temperatures will cool off to become somewhat marginal for snow late in the night, however precipitation should be mainly rain throughout central IL, with perhaps a brief change to a mix of snow and rain toward the end of precipitation Saturday morning. Even with temperatures cooling close to freezing late in the night, moisture depth may drop off too dramatically for anything more than liquid drizzle to form at that point. A trend toward warmer temperatures is then in store for Saturday through Tuesday as a high pressure ridge shifts eastward to the central and eastern U.S. Highs on Saturday range from 45 in Galesburg to 55 in Lawrenceville...and are expected to increase to the mid and upper 60s by Tuesday. Meanwhile, lows Saturday night are expected to cool to a few degrees below freezing, but should trend upward to the low 50s by Monday night. A series of small waves ejecting out of a trough over the western states will bring periodic chances for showers and some thunderstorms through central and southeast IL for much of the upcoming work week. Temperatures should remain mild, with highs in the 50s or 60s through midweek, and lows generally 40s or low 50s. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 1156 AM CST THU MAR 3 2016 IFR ceilings have developed over the past couple of hours and will persist through the early afternoon. Forecast soundings suggest MVFR ceilings will return after the 20-22z time frame. Based on radar trends and latest Rapid Refresh forecast, it appears light snow will taper off at KPIA at 18z...with light rain ending further east at KCMI by around 22z. As low pressure passes to the south of Illinois, winds will gradually swing around to the north at all terminals by early evening. Northerly winds are then expected to continue through the night before becoming light/variable by Friday morning. Clearing appears to be delayed from previous forecasts, with all models suggesting MVFR ceilings continuing through the night. Have scattered the clouds as per NAM soundings between 14z and 16z Fri. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Barnes LONG TERM...Onton AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
227 AM CST THU MAR 3 2016 .UPDATE... 826 PM CST FOR EVENING UPDATE... HAVE MADE SOME MINOR ADJUSTMENTS TO HOURLY POP/WX BASED ON CURRENT OBS AND RECENT HIGH-RES GUIDANCE RUNS...PRIMARILY TO TIGHTEN UP POP GRADIENTS THROUGH THIS EVENING AND TO ADD SOME DETAIL TO TIMING OF SNOW ONSET FROM PARTS OF NORTH CENTRAL IL NEXT COUPLE OF HOURS INTO PARTS OF CHICAGO/KANKAKEE AREAS BY/SHORTLY AFTER MIDNIGHT. BASED ON TRENDS FROM 18Z 4KM NAM AND SEVERAL RECENT HRRR RUNS HAVE ELECTED TO INCLUDE KANKAKEE COUNTY IN THE WINTER WEATHER ADVISORY...WITH GUIDANCE FOCUSING BETTER (2-4) SNOW ACCUMULATION AXIS GENERALLY ALIGNING ALONG AN AXIS FROM SQI- VYS-JOT-IKK AREAS. MID-EVENING REGIONAL RADAR MOSAIC DEPICTING PATCHY BANDED RETURNS DEVELOPING ACROSS ESPECIALLY WEST/SOUTHWEST COUNTIES OF IL PORTION OF CWA. STRONGER (20-25 DBZ) ECHOES HAVE BEEN SOMEWHAT TRANSIENT IN FORMING/WEAKENING IN REGIONS OF WEAK MID-LEVEL FRONTOGENETIC FORCING WHICH GUIDANCE SUGGESTS WILL BE SOMEWHAT WEAKLY FOCUSED OVERNIGHT. DRY LOW-LEVEL AIR ALSO HELPING TO KEEP BETTER RETURNS LIMITED INITIALLY THIS EVENING...WITH FAIRLY LARGE TEMP-DEW POINT SPREADS BELOW ABOUT 700 MB AS DEPICTED BY EARLY EVENING AMDAR SOUNDINGS OUT OF ORD/MDW. GRADUALLY SEEING MORE CLOUD LAYERS BELOW 5000 FT HOWEVER AND SAVANNA IL (KSFY) ALONG THE MISSISSIPPI TO OUR WEST NOW REPORTING 3SM IN LIGHT SNOW...SO LIGHT SNOW IS LIKELY FAIRLY SOON ACROSS IL COUNTIES WEST/SOUTHWEST OF CHICAGO. FRONTOGENETIC BANDING IS LIKELY TO REMAIN A BIT TRANSIENT BASED ON RELATIVELY UNIMPRESSIVE F-GEN FIELDS IN VARIOUS MODELS DURING THE DURATION OF THIS EVENT...THOUGH PERSISTENT MOIST ISENTROPIC ASCENT APPEARS TO MAXIMIZE FORCING AROUND THE 285 K SURFACE INTO THURSDAY. WHILE MUCH OF THE DEEPER ASCENT DIRECTLY AHEAD OF THE PRIMARY VORT TRACK LOOKS TO REMAIN SOUTH OF THE CWA...GUIDANCE HAS REMAINED FAIRLY CONSISTENT IN MAINTAINING AN AXIS OF GREATEST QPF FROM SQI/VYS THROUGH JOT/IKK AREAS...WHERE IT APPEARS AMOUNTS OF 3-4 INCHES ARE MOST LIKELY. AMOUNTS SHOULD TAPER OFF TO 1-2 ALONG/NORTH OF THE I-90 CORRIDOR...AND INTO CENTRAL IL/IN WHERE THERMAL PROFILES BECOME MARGINAL FOR ALL SNOW DURING THE DAY THURSDAY. ISENTROPIC DOWNGLIDE DEVELOPS THURSDAY AFTERNOON RESULTING IN SNOW TAPERING OFF FROM WEST TO EAST ESPECIALLY LATER IN THE AFTERNOON AND EARLY EVENING. SO OVERALL...TRIED TO TIGHTEN UP POP/QPF/SNOW AMOUNT AXIS JUST A BIT BASED ON RECENT GUIDANCE TRENDS...ALONG WITH ADDING KANKAKEE COUNTY TO THE WINTER WEATHER ADVISORY. NO BIG DEAL...BUT TIMING WILL IMPACT MORNING COMMUTE. RATZER && .SHORT TERM... 258 PM CST THROUGH THURSDAY... BOTTOM LINE UP FRONT...SNOW WILL BE MOVING IN LATE THIS EVENING FROM WEST TO EAST AND PERSIST INTO THURSDAY. HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE COUNTIES BETWEEN 1-88 AND 1-80. THIS ADVISORY IS STRICTLY FOR IMPACTS TO THE MORNING RUSH FROM THE SNOW AS WE WILL LIKELY NOT SEE WIDESPREAD 3-5 INCHES OF SNOW. SNOW WILL PICK UP IN THE MORNING AFTER 4AM WITH MODERATE SNOW CONTINUING THROUGH THE MORNING RUSH HOUR. SNOW SHOULD TAPER DOWN TO STEADY LIGHT SNOW IN THE MID TO LATE MORNING AND THEN END FROM WEST TO EAST IN THE AFTERNOON. ONCE AGAIN...ONLY EXPECTING 2-4 INCHES OF SNOW IN THE ADVISORY AREA...WITH SNOW PICKING UP AND IMPACTING THE MORNING RUSH HOUR. EXPECTING THE BEST CHANCE FOR AMOUNTS UP TO 4 INCHES TO BE FROM SOUTHWEST KANE COUNTIES SOUTHWARD TO GRUNDY COUNTY AND POINTS WEST...INCLUDING THE MENDOTA AND AMBOY AREAS. TONIGHT...HIGH PRESSURE SHIFTS EAST AND CLOUD COVER INCREASES. LIGHT WINDS BACK TO SOUTHEAST AND THEN EAST BY SUNRISE. THE LOW CURRENTLY FORMING OVER THE PLAINS REACHES THE ARKLATEX REGION BY EARLY THURSDAY MORNING. SNOW SPREADS FROM WEST TO EAST LATE THIS EVENING AND OVERNIGHT WITH A LIGHT STEADY SNOW EXPECTED. SURFACE TEMPS SHOULD ALLOW SNOW TO ACCUMULATE QUITE EASILY. HAVE HIGH CONFIDENCE IN ACCUMULATING SNOW NORTH OF A PONTIAC IL TO RENSSELAER IN LINE OVERNIGHT. AREAS SOUTH OF THAT LINE MAY SEE A BREAK IN SNOW OVERNIGHT DUE TO DRY AIR MOVING INTO THE LOW LEVELS OF THE ATMOSPHERE. LEFT A CHANCE OF SNOW IN THE FORECAST BECAUSE SNOW MAY SATURATE THE LOW LEVELS AND LEAD TO VERY LIGHT SNOW. HAVE MEDIUM CONFIDENCE IN SNOW SOUTH OF THE PONTIAC TO RENSSELAER LINE OVERNIGHT. THURSDAY...SNOW INTENSIFIES EARLY THURSDAY MORNING DURING RUSH HOUR. SNOW RATES INCREASE TO AROUND A HALF INCH PER HOUR...BUT THE BIGGER IMPACTS WILL BE VISIBILITIES OF LESS THAN A MILE AT TIMES. PERIODS OF 1/2SM VISIBILITY IS VERY PSBL...WHICH WILL IMPACT TRAVEL CONDITIONS IN ADDITION TO SNOW COVERED AND SLIPPERY ROADWAYS. EXPECTING THE INCREASE IN SNOW INTENSITY BECAUSE OMEGA INCREASES JUST BELOW THE DGZ ACCORDING TO FORECAST SOUNDINGS. COULD SEE HIGHER SNOWFALL RATES AND LOWER VISIBILITIES IF THE FORCING ALIGNS BETTER WITH THE DGZ. WINNEBAGO THROUGH LAKE IL COUNTIES IN FAR NORTHERN IL WILL SEE LOWER SNOWFALL AMOUNTS WITH THE BAND OF MODERATE SNOW JUST TO THE SOUTH...WHICH IS WHY THESE COUNTIES ARE NOT IN THE ADVISORY. AREAS WELL SOUTH OF 1-80 WILL WARM TO ABOVE FREEZING THURSDAY SO EXPECTING RAIN AND SNOW. THIS WILL LIMIT SNOWFALL AMOUNTS AND IS THE REASON THIS AREA WAS NOT INCLUDED IN THE ADVISORY. FREEZING RAIN AND SLEET ARE NOT EXPECTED AS SATURATED SOUNDINGS WARM THROUGH THE LOWER LEVELS LEADING TO ALL RAIN. LOWERED WIND SPEEDS FOR THURSDAY WITH EAST WINDS AT 10-15 MPH. AN OCNL GUST TO 20 MPH IS PSBL. THE SNOW MAY BLOW AROUND A LITTLE...BUT NOT OVERLY CONCERNED ABOUT BLOWING SNOW AT THIS TIME GIVEN THE LOWER WIND SPEEDS. JEE && .LONG TERM... 249 PM CST THURSDAY NIGHT THROUGH WEDNESDAY... CONTINUED SEASONABLY COOL BUT PRIMARILY DRY WEATHER IS EXPECTED TO CLOSE OUT THE WEEK...THEN PATTERN TRANSITIONS TO ONE MORE TYPICAL OF SPRING WHICH WILL RESULT IN WARMER AND UNSETTLED WEATHER AS WE GET LATE INTO THE WEEKEND AND INTO NEXT WEEK... BACK END OF DEFORMATION ZONE FROM DEPARTING LOW MAY RESULT IN SOME LINGERING LIGHT SNOW MAINLY ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA THURSDAY EVENING/NIGHT BUT HIGH PRESSURE BUILDING IN FROM THE WEST WILL RESULT DRY CONDITIONS OVERSPREADING THE REGION BY FRIDAY MORNING. UPPER LEVEL RIDGE IS PROGGED TO AMPLIFY ACROSS THE WESTERN CONUS FRIDAY WITH MID LEVEL WAA OVERSPREADING PORTIONS OF THE MID AND UPPER MISSISSIPPI VALLEY. STILL ON THE COLD SIDE OF THE BAROCLINIC ZONE FRIDAY...EXPECT HIGHS TO ONLY BE IN THE 30S ACROSS THE OUTLOOK AREA. MEANWHILE...SHORTWAVE TROUGH RIDING DOWN THE LEE SIDE OF THE RIDGE IS PROGGED TO DIVE FROM MINNESOTA FRIDAY EVENING TO ACROSS IL/IN BY MIDDAY SATURDAY. THIS CLIPPER SYSTEM WILL BRING ADDITIONAL CHANCES FOR SNOW FRIDAY NIGHT INTO EARLY SATURDAY WITH ACCUMULATING SNOWFALL POSSIBLE. SURFACE RIDGE BUILDS BACK OVERHEAD SATURDAY EVENING AND NIGHT...THEN WINDS TURN SOUTHERLY LATE SATURDAY NIGHT INTO SUNDAY WITH THE BAROCLINIC ZONE FINALLY MAKING A STRONG SURGE ACROSS THE AREA. THIS WILL RESULT IN A WARMING TREND SUNDAY THROUGH TUESDAY. EXPECT MID 40S NORTH TO LOW 50S SOUTH SUNDAY...AND BY TUESDAY AND WEDNESDAY THERE IS A POSSIBILITY OF SEEING 60S ACROSS THE ENTIRE OUTLOOK AREA. DEEPENING UPPER TROUGH OVER THE MID SECTION OF THE COUNTRY WILL BE IN PLACE WITH SEVERAL SHORTWAVES EJECTING ACROSS PLAINS INTO THE MIDWEST. THIS WILL SET THE STAGE FOR ACTIVE/WET WEATHER AND POSSIBLY EVEN A FEW PERIODS OF THUNDERSTORMS AS GUIDANCE SUGGESTS AT LEAST MODEST INSTABILITY POSSIBLE. UPPER LOW IS PROGGED TO CUT-OFF OVER THE SOUTHERN PLAINS AFTER MIDWEEK RESULTING IN CONTINUED ACTIVE WEATHER LATE IN THE WEEK BUT HIGH DEGREE OF UNCERTAINTY IN THE DETAILS. BMD && .AVIATION... FOR THE 06Z TAFS... LIGHT SNOW WILL CONTINUE OVERNIGHT AND INTO THURSDAY MORNING...GRADUALLY TAPERING OFF FROM THE NORTH THURSDAY MORNING. LATEST OBSERVATIONAL TRENDS SUGGEST THAT THE SNOW HAS ERODED THE LOW LEVEL DRY LAYER AND ANTICIPATE LIGHT SNOW OF VARYING INTENSITY TO CONTINUE WITH FLUCTUATIONS IN VSBY MOSTLY BETWEEN MVFR AND IFR...THOUGH BRIEF LIFR VSBY IS POSSIBLE...PARTICULARLY THE MORE SOUTHERN TERMINALS. AS LOW LEVELS SATURATE...CIGS SHOULD BUILD DOWN TO IFR BY BY EARLY THURS MORNING AND LIKELY REMAIN IFR THROUGH THE DAY. COULD SEE SOME FLURRIES LINGER INTO THE AFTERNOON...PARTICULARLY SOUTH. CIGS LIKELY TO CONTINUE TO IMPROVE THURSDAY NIGHT. IZZI && .MARINE... 227 AM...A RIDGE OF HIGH PRESSURE EXTENDS FROM ONTARIO ACROSS THE EASTERN LAKES TO THE MID ATLANTIC THIS MORNING. THIS RIDGE WILL MOVE NORTHEAST TODAY AND TONIGHT. LOW PRESSURE OVER THE PLAINS IS NOW EXPECTED TO MOVE EAST...FURTHER SOUTH AND AS A RESULT THE GRADIENT DOESN/T APPEAR TO TIGHTEN AS MUCH OVER THE SOUTHERN END OF THE LAKE. EAST/NORTHEAST WINDS WILL STILL INCREASE BUT SHOULD DIMINISH FASTER THIS EVENING. SOUTHERLY WINDS WILL INCREASE FRIDAY INTO FRIDAY NIGHT AHEAD OF LOW PRESSURE MOVING SOUTHEAST FROM THE NORTHERN PLAINS. THIS LOW WILL BE WEAKENING FRIDAY NIGHT AS IT CROSSES THE LAKE...BUT THERE COULD BE SOME GUSTS TO 30 KTS AS THE LOW APPROACHES. THE GRADIENT BRIEFLY TIGHTENS ON SATURDAY AS THE LOW DEPARTS AND HIGH PRESSURE BUILDS ACROSS THE WESTERN LAKES. A SHORT PERIOD OF 15-25KT IS POSSIBLE. WINDS WILL DIMINISH SATURDAY NIGHT AS THE HIGH PASSES OVER THE LAKE AND WINDS WILL TURN SOUTHERLY SUNDAY AS LOW PRESSURE MOVES ACROSS THE PLAINS SUNDAY THROUGH TUESDAY. THERE COULD BE SOME GUSTS TO 30KTS SUNDAY NIGHT. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER WEATHER ADVISORY...ILZ012-ILZ013-ILZ014-ILZ020-ILZ021- ILZ022-ILZ023 UNTIL 2 PM THURSDAY. WINTER WEATHER ADVISORY...ILZ008-ILZ010-ILZ011-ILZ019 UNTIL 10 AM THURSDAY. IN...WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL 2 PM THURSDAY. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...6 AM THURSDAY TO 10 PM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1052 PM CST WED MAR 2 2016 .UPDATE... 826 PM CST FOR EVENING UPDATE... HAVE MADE SOME MINOR ADJUSTMENTS TO HOURLY POP/WX BASED ON CURRENT OBS AND RECENT HIGH-RES GUIDANCE RUNS...PRIMARILY TO TIGHTEN UP POP GRADIENTS THROUGH THIS EVENING AND TO ADD SOME DETAIL TO TIMING OF SNOW ONSET FROM PARTS OF NORTH CENTRAL IL NEXT COUPLE OF HOURS INTO PARTS OF CHICAGO/KANKAKEE AREAS BY/SHORTLY AFTER MIDNIGHT. BASED ON TRENDS FROM 18Z 4KM NAM AND SEVERAL RECENT HRRR RUNS HAVE ELECTED TO INCLUDE KANKAKEE COUNTY IN THE WINTER WEATHER ADVISORY...WITH GUIDANCE FOCUSING BETTER (2-4) SNOW ACCUMULATION AXIS GENERALLY ALIGNING ALONG AN AXIS FROM SQI- VYS-JOT-IKK AREAS. MID-EVENING REGIONAL RADAR MOSAIC DEPICTING PATCHY BANDED RETURNS DEVELOPING ACROSS ESPECIALLY WEST/SOUTHWEST COUNTIES OF IL PORTION OF CWA. STRONGER (20-25 DBZ) ECHOES HAVE BEEN SOMEWHAT TRANSIENT IN FORMING/WEAKENING IN REGIONS OF WEAK MID-LEVEL FRONTOGENETIC FORCING WHICH GUIDANCE SUGGESTS WILL BE SOMEWHAT WEAKLY FOCUSED OVERNIGHT. DRY LOW-LEVEL AIR ALSO HELPING TO KEEP BETTER RETURNS LIMITED INITIALLY THIS EVENING...WITH FAIRLY LARGE TEMP-DEW POINT SPREADS BELOW ABOUT 700 MB AS DEPICTED BY EARLY EVENING AMDAR SOUNDINGS OUT OF ORD/MDW. GRADUALLY SEEING MORE CLOUD LAYERS BELOW 5000 FT HOWEVER AND SAVANNA IL (KSFY) ALONG THE MISSISSIPPI TO OUR WEST NOW REPORTING 3SM IN LIGHT SNOW...SO LIGHT SNOW IS LIKELY FAIRLY SOON ACROSS IL COUNTIES WEST/SOUTHWEST OF CHICAGO. FRONTOGENETIC BANDING IS LIKELY TO REMAIN A BIT TRANSIENT BASED ON RELATIVELY UNIMPRESSIVE F-GEN FIELDS IN VARIOUS MODELS DURING THE DURATION OF THIS EVENT...THOUGH PERSISTENT MOIST ISENTROPIC ASCENT APPEARS TO MAXIMIZE FORCING AROUND THE 285 K SURFACE INTO THURSDAY. WHILE MUCH OF THE DEEPER ASCENT DIRECTLY AHEAD OF THE PRIMARY VORT TRACK LOOKS TO REMAIN SOUTH OF THE CWA...GUIDANCE HAS REMAINED FAIRLY CONSISTENT IN MAINTAINING AN AXIS OF GREATEST QPF FROM SQI/VYS THROUGH JOT/IKK AREAS...WHERE IT APPEARS AMOUNTS OF 3-4 INCHES ARE MOST LIKELY. AMOUNTS SHOULD TAPER OFF TO 1-2 ALONG/NORTH OF THE I-90 CORRIDOR...AND INTO CENTRAL IL/IN WHERE THERMAL PROFILES BECOME MARGINAL FOR ALL SNOW DURING THE DAY THURSDAY. ISENTROPIC DOWNGLIDE DEVELOPS THURSDAY AFTERNOON RESULTING IN SNOW TAPERING OFF FROM WEST TO EAST ESPECIALLY LATER IN THE AFTERNOON AND EARLY EVENING. SO OVERALL...TRIED TO TIGHTEN UP POP/QPF/SNOW AMOUNT AXIS JUST A BIT BASED ON RECENT GUIDANCE TRENDS...ALONG WITH ADDING KANKAKEE COUNTY TO THE WINTER WEATHER ADVISORY. NO BIG DEAL...BUT TIMING WILL IMPACT MORNING COMMUTE. RATZER && .SHORT TERM... 258 PM CST THROUGH THURSDAY... BOTTOM LINE UP FRONT...SNOW WILL BE MOVING IN LATE THIS EVENING FROM WEST TO EAST AND PERSIST INTO THURSDAY. HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE COUNTIES BETWEEN 1-88 AND 1-80. THIS ADVISORY IS STRICTLY FOR IMPACTS TO THE MORNING RUSH FROM THE SNOW AS WE WILL LIKELY NOT SEE WIDESPREAD 3-5 INCHES OF SNOW. SNOW WILL PICK UP IN THE MORNING AFTER 4AM WITH MODERATE SNOW CONTINUING THROUGH THE MORNING RUSH HOUR. SNOW SHOULD TAPER DOWN TO STEADY LIGHT SNOW IN THE MID TO LATE MORNING AND THEN END FROM WEST TO EAST IN THE AFTERNOON. ONCE AGAIN...ONLY EXPECTING 2-4 INCHES OF SNOW IN THE ADVISORY AREA...WITH SNOW PICKING UP AND IMPACTING THE MORNING RUSH HOUR. EXPECTING THE BEST CHANCE FOR AMOUNTS UP TO 4 INCHES TO BE FROM SOUTHWEST KANE COUNTIES SOUTHWARD TO GRUNDY COUNTY AND POINTS WEST...INCLUDING THE MENDOTA AND AMBOY AREAS. TONIGHT...HIGH PRESSURE SHIFTS EAST AND CLOUD COVER INCREASES. LIGHT WINDS BACK TO SOUTHEAST AND THEN EAST BY SUNRISE. THE LOW CURRENTLY FORMING OVER THE PLAINS REACHES THE ARKLATEX REGION BY EARLY THURSDAY MORNING. SNOW SPREADS FROM WEST TO EAST LATE THIS EVENING AND OVERNIGHT WITH A LIGHT STEADY SNOW EXPECTED. SURFACE TEMPS SHOULD ALLOW SNOW TO ACCUMULATE QUITE EASILY. HAVE HIGH CONFIDENCE IN ACCUMULATING SNOW NORTH OF A PONTIAC IL TO RENSSELAER IN LINE OVERNIGHT. AREAS SOUTH OF THAT LINE MAY SEE A BREAK IN SNOW OVERNIGHT DUE TO DRY AIR MOVING INTO THE LOW LEVELS OF THE ATMOSPHERE. LEFT A CHANCE OF SNOW IN THE FORECAST BECAUSE SNOW MAY SATURATE THE LOW LEVELS AND LEAD TO VERY LIGHT SNOW. HAVE MEDIUM CONFIDENCE IN SNOW SOUTH OF THE PONTIAC TO RENSSELAER LINE OVERNIGHT. THURSDAY...SNOW INTENSIFIES EARLY THURSDAY MORNING DURING RUSH HOUR. SNOW RATES INCREASE TO AROUND A HALF INCH PER HOUR...BUT THE BIGGER IMPACTS WILL BE VISIBILITIES OF LESS THAN A MILE AT TIMES. PERIODS OF 1/2SM VISIBILITY IS VERY PSBL...WHICH WILL IMPACT TRAVEL CONDITIONS IN ADDITION TO SNOW COVERED AND SLIPPERY ROADWAYS. EXPECTING THE INCREASE IN SNOW INTENSITY BECAUSE OMEGA INCREASES JUST BELOW THE DGZ ACCORDING TO FORECAST SOUNDINGS. COULD SEE HIGHER SNOWFALL RATES AND LOWER VISIBILITIES IF THE FORCING ALIGNS BETTER WITH THE DGZ. WINNEBAGO THROUGH LAKE IL COUNTIES IN FAR NORTHERN IL WILL SEE LOWER SNOWFALL AMOUNTS WITH THE BAND OF MODERATE SNOW JUST TO THE SOUTH...WHICH IS WHY THESE COUNTIES ARE NOT IN THE ADVISORY. AREAS WELL SOUTH OF 1-80 WILL WARM TO ABOVE FREEZING THURSDAY SO EXPECTING RAIN AND SNOW. THIS WILL LIMIT SNOWFALL AMOUNTS AND IS THE REASON THIS AREA WAS NOT INCLUDED IN THE ADVISORY. FREEZING RAIN AND SLEET ARE NOT EXPECTED AS SATURATED SOUNDINGS WARM THROUGH THE LOWER LEVELS LEADING TO ALL RAIN. LOWERED WIND SPEEDS FOR THURSDAY WITH EAST WINDS AT 10-15 MPH. AN OCNL GUST TO 20 MPH IS PSBL. THE SNOW MAY BLOW AROUND A LITTLE...BUT NOT OVERLY CONCERNED ABOUT BLOWING SNOW AT THIS TIME GIVEN THE LOWER WIND SPEEDS. JEE && .LONG TERM... 249 PM CST THURSDAY NIGHT THROUGH WEDNESDAY... CONTINUED SEASONABLY COOL BUT PRIMARILY DRY WEATHER IS EXPECTED TO CLOSE OUT THE WEEK...THEN PATTERN TRANSITIONS TO ONE MORE TYPICAL OF SPRING WHICH WILL RESULT IN WARMER AND UNSETTLED WEATHER AS WE GET LATE INTO THE WEEKEND AND INTO NEXT WEEK... BACK END OF DEFORMATION ZONE FROM DEPARTING LOW MAY RESULT IN SOME LINGERING LIGHT SNOW MAINLY ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA THURSDAY EVENING/NIGHT BUT HIGH PRESSURE BUILDING IN FROM THE WEST WILL RESULT DRY CONDITIONS OVERSPREADING THE REGION BY FRIDAY MORNING. UPPER LEVEL RIDGE IS PROGGED TO AMPLIFY ACROSS THE WESTERN CONUS FRIDAY WITH MID LEVEL WAA OVERSPREADING PORTIONS OF THE MID AND UPPER MISSISSIPPI VALLEY. STILL ON THE COLD SIDE OF THE BAROCLINIC ZONE FRIDAY...EXPECT HIGHS TO ONLY BE IN THE 30S ACROSS THE OUTLOOK AREA. MEANWHILE...SHORTWAVE TROUGH RIDING DOWN THE LEE SIDE OF THE RIDGE IS PROGGED TO DIVE FROM MINNESOTA FRIDAY EVENING TO ACROSS IL/IN BY MIDDAY SATURDAY. THIS CLIPPER SYSTEM WILL BRING ADDITIONAL CHANCES FOR SNOW FRIDAY NIGHT INTO EARLY SATURDAY WITH ACCUMULATING SNOWFALL POSSIBLE. SURFACE RIDGE BUILDS BACK OVERHEAD SATURDAY EVENING AND NIGHT...THEN WINDS TURN SOUTHERLY LATE SATURDAY NIGHT INTO SUNDAY WITH THE BAROCLINIC ZONE FINALLY MAKING A STRONG SURGE ACROSS THE AREA. THIS WILL RESULT IN A WARMING TREND SUNDAY THROUGH TUESDAY. EXPECT MID 40S NORTH TO LOW 50S SOUTH SUNDAY...AND BY TUESDAY AND WEDNESDAY THERE IS A POSSIBILITY OF SEEING 60S ACROSS THE ENTIRE OUTLOOK AREA. DEEPENING UPPER TROUGH OVER THE MID SECTION OF THE COUNTRY WILL BE IN PLACE WITH SEVERAL SHORTWAVES EJECTING ACROSS PLAINS INTO THE MIDWEST. THIS WILL SET THE STAGE FOR ACTIVE/WET WEATHER AND POSSIBLY EVEN A FEW PERIODS OF THUNDERSTORMS AS GUIDANCE SUGGESTS AT LEAST MODEST INSTABILITY POSSIBLE. UPPER LOW IS PROGGED TO CUT-OFF OVER THE SOUTHERN PLAINS AFTER MIDWEEK RESULTING IN CONTINUED ACTIVE WEATHER LATE IN THE WEEK BUT HIGH DEGREE OF UNCERTAINTY IN THE DETAILS. BMD && .AVIATION... FOR THE 06Z TAFS... LIGHT SNOW WILL CONTINUE OVERNIGHT AND INTO THURSDAY MORNING...GRADUALLY TAPERING OFF FROM THE NORTH THURSDAY MORNING. LATEST OBSERVATIONAL TRENDS SUGGEST THAT THE SNOW HAS ERODED THE LOW LEVEL DRY LAYER AND ANTICIPATE LIGHT SNOW OF VARYING INTENSITY TO CONTINUE WITH FLUCTUATIONS IN VSBY MOSTLY BETWEEN MVFR AND IFR...THOUGH BRIEF LIFR VSBY IS POSSIBLE...PARTICULARLY THE MORE SOUTHERN TERMINALS. AS LOW LEVELS SATURATE...CIGS SHOULD BUILD DOWN TO IFR BY BY EARLY THURS MORNING AND LIKELY REMAIN IFR THROUGH THE DAY. COULD SEE SOME FLURRIES LINGER INTO THE AFTERNOON...PARTICULARLY SOUTH. CIGS LIKELY TO CONTINUE TO IMPROVE THURSDAY NIGHT. IZZI && .MARINE... 249 PM CST WINDS ACROSS LAKE MICHIGAN WILL CONTINUE TO DIMINISH THIS EVENING AND TONIGHT AS HIGH PRESSURE BUILDS ACROSS THE REGION...THEN EAST TO SOUTHEASTERLY FLOW WILL RAMP UP STARTING EARLY THURSDAY AS LOW PRESSURE MAKES ITS WAY ACROSS THE MID MISSISSIPPI VALLEY. WINDS INCREASE INTO THE 20 TO 25 KT RANGE MAINLY ACROSS THE SOUTH END OF LAKE MICHIGAN THURSDAY...THEN SHOULD DIMINISH AGAIN THURSDAY NIGHT AS THE LOW DEPARTS TO THE EAST COAST AND HIGH PRESSURE BUILDS BACK OVER THE REGION. SOUTHERLY FLOW INCREASES AGAIN ON FRIDAY AHEAD OF A CLIPPER SYSTEM WHICH IS PROGGED TO TRACK ACROSS SOUTHERN LAKE MICHIGAN ON SATURDAY. NORTHERLY WINDS BRIEFLY OVERSPREAD LAKE MICHIGAN AGAIN SATURDAY NIGHT THEN SOUTHERLY WINDS ARE EXPECTED AGAIN SUNDAY AS BROAD AREA OF LOW PRESSURE DEVELOPS OVER THE PLAINS. .SYNOPSIS...BROAD HIGH PRESSURE AVERAGING 30.2 INCHES STRETCHES ALONG THE MISSISSIPPI RIVER VALLEY WHILE LOW PRESSURE OF 29.7 INCHES IS IN PLACE OVER THE CENTRAL AND NORTHERN PLAINS. THE LOW WILL MOVE ACROSS THE MID MISSISSIPPI VALLEY MIDDAY THURSDAY THEN SHIFT TO THE ATLANTIC COAST BY EARLY FRIDAY. ANOTHER RIDGE OF 30.2 INCHES WILL BUILD ACROSS THE WESTERN GREAT LAKES FRIDAY AND SHIFT TO THE EASTERN LAKES SATURDAY. LOW PRESSURE OF 29.9 INCHES WILL DROP INTO MINNESOTA FRIDAY NIGHT AND CROSS SOUTHERN LAKE MICHIGAN SATURDAY. HIGH PRESSURE OF 30.3 INCHES BUILDS ACROSS THE WESTERN LAKES SATURDAY AND MOVES TO THE UPPER OHIO VALLEY SUNDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER WEATHER ADVISORY...ILZ012-ILZ013-ILZ014-ILZ020-ILZ021- ILZ022-ILZ023 UNTIL 2 PM THURSDAY. WINTER WEATHER ADVISORY...ILZ008-ILZ010-ILZ011-ILZ019 UNTIL 10 AM THURSDAY. IN...WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL 2 PM THURSDAY. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...6 AM THURSDAY TO 10 PM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
600 PM EST THU MAR 3 2016 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 315 PM EST THU MAR 3 2016 RAIN AND SNOW WILL END TONIGHT AS A TROUGH MOVES AWAY. A LOW PRESSURE SYSTEM WILL BRING A RETURN OF PRECIPITATION CHANCES FRIDAY NIGHT INTO SATURDAY...AND A FRONTAL SYSTEM WILL BRING RAIN NEXT WEEK. TEMPERATURES WILL WARM TO WELL ABOVE AVERAGE BY NEXT WEEK. && .NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/ ISSUED AT 315 PM EST THU MAR 3 2016 SNOW IS HANGING AROUND THE FAR NORTH AND FAR SOUTHEAST WHILE TEMPERATURES HAVE WARMED ENOUGH FOR RAIN ELSEWHERE. AN INVERTED TROUGH REMAINS ACROSS THE FAR NORTH. THIS TROUGH WILL SLIDE SOUTHEAST ACROSS THE FORECAST AREA THIS EVENING. AN UPPER JET WILL PROVIDE ADDITIONAL SUPPORT. BASED THIS FORCING WENT LIKELY POPS ACROSS THE NORTH THIRD OR SO OF THE AREA TAPERING DOWN TO SLIGHT CHANCE FAR SOUTH. FORCING DIMINISHES QUICKLY OVERNIGHT AS THE SYSTEM EXITS SO LOWERED POPS ACCORDINGLY. PRECIPITATION TYPE WILL BE TRICKY. AS WARMER AIR HAS SLOWLY WORKED ITS WAY NORTH...WENT RAIN/SNOW NORTH...WITH MAINLY RAIN SOUTH EARLY THIS EVENING. AS BOUNDARY LAYER COOLS...PRECIPITATION WILL CHANGEOVER TO SNOW DURING THE EVENING MOST AREAS. AFTER SUNSET SNOW MIGHT ACCUMULATE ON GRASSY AREAS NORTH WHERE TEMPERATURES ARE COOLER...SO WENT A FEW TENTHS OF ACCUMULATION THERE. NO SNOW ACCUMULATION SOUTH. MAV MOS LOOKS GOOD FOR LOW TEMPERATURES. && .SHORT TERM.../FRIDAY THROUGH SUNDAY/ ISSUED AT 315 PM EST THU MAR 3 2016 FOCUS IS ON PRECIPITATION CHANCES FRIDAY NIGHT/SATURDAY. OVERALL...MODELS ARE CLOSE ENOUGH FOR A BLEND UNLESS NOTED BELOW. CLOUDS WILL DECREASE SOME FRIDAY...BUT THAT WILL NOT LAST LONG AS MID AND HIGH CLOUDS INCREASE AHEAD OF THE NEXT LOW PRESSURE SYSTEM. USED A BLEND FOR HIGH TEMPERATURES. ISENTROPIC LIFT WILL INCREASE AHEAD OF THE WARM FRONT PART OF THE LOW PRESSURE SYSTEM FRIDAY EVENING. LOOKS LIKE FORCING/MOISTURE REMAIN LOW ENOUGH TO KEEP THE EVENING DRY...BUT POPS ARE WARRANTED OVERNIGHT FRIDAY NIGHT AS THE SYSTEM GETS CLOSER. WITH ISENTROPIC LIFT AND Q-VECTOR CONVERGENCE PROGS BOTH SHOWING DECENT FORCING...WENT HIGH CHANCE CATEGORY POPS NORTH AND LOWER CHANCES ELSEWHERE. PRECIPITATION TYPE WILL BE PROBLEMATIC ONCE AGAIN WITH THERMAL PROFILES HOVERING AROUND THE FREEZING MARK. WILL GO A MIX OF RAIN/SNOW SOUTHWEST HALF AND SNOW NORTHEAST FOR NOW. KEPT SNOW AMOUNTS TO JUST A FEW TENTHS GIVEN THE EXPECTED BORDERLINE TEMPERATURE PROFILES. /GFS LOOKS TOO STRONG THOUGH WITH ITS FORCING COMPARED TO OTHERS AND IS SHOWING 3 INCHES OF SNOW. DID NOT GO THAT HIGH/. TEMPERATURES WILL WARM DURING SATURDAY FOR ALL PRECIPITATION TO BE RAIN BY AFTERNOON. HOWEVER FORCING DECREASES DURING THE DAY SO POPS WILL LOWER FROM WEST TO EAST DURING THE DAY AS WELL. DRY CONDITIONS WILL RETURN SATURDAY NIGHT INTO SUNDAY AS HIGH PRESSURE MOVES IN. STUCK WITH A BLEND OF MODELS FOR TEMPERATURES THROUGH THE SHORT TERM. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 218 PM EST THU MAR 3 2016 THE INITIALIZATION FROM THE REGIONAL SOFTWARE WILL BE USED WITH HIGH CONFIDENCE INTO TUESDAY...THEN MODERATE CONFIDENCE. THERE IS GOOD AGREEMENT BETWEEN DIFFERENT FORECAST METHODS INTO TUESDAY. INDIANA WEATHER WILL BE DOMINATED BY LARGE POWERFUL SYSTEMS RELATIVELY EASY TO PREDICT. AS THE WEEK DRAWS ON THE EUROPEAN MODEL AND THE GFS BECOME MORE DISTINCT. AT THE SAME TIME THE ENSEMBLE SPREAD WITHIN THE GFS PARENT MODEL GROWS. THE DIFFERENCES ARENT HUGE BUT INVOLVE FEATURES WHOSE PRECISE POSITION WILL BE IMPORTANT. A HIGH CONFIDENCE FORECAST FOR WEDNESDAY AND THURSDAY MAY HAVE TO WAIT UNTIL AT LEAST SATURDAY. && .AVIATION /DISCUSSION FOR 040000Z TAF ISSUANCE/... ISSUED AT 600 PM EST THU MAR 3 2016 RADAR AND HRRR SUGGEST IND AND LAF WILL SEE A THREAT FOR LIGHT PRECIPITATION UNTIL NEAR 06Z. THE RAIN SHOULD CHANGE TO SNOW AFTER 01Z. OTHERWISE...PRECIP CHANCES TOO LOW TO MENTION AT BMG AND HUF. LAMP MOS ALSO STRONGLY SUGGESTS MVFR CEILINGS WILL BECOME IFR BY 03Z OR EARLIER BEFORE IMPROVING TO MVFR TOWARD 12Z AND VFR AFTER 16Z. CONFIDENCE IS NOT GREAT ON EXACT TIMING...BUT GOOD REGARDING TRENDS. WINDS WILL VEER FROM SOUTHEAST TO SOUTHWEST LESS THAN 10 KNOTS OVERNIGHT AND BECOME LIGHT NORTH OR NORTHEAST AFTER 12Z. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...50 SHORT TERM...50 LONG TERM....JK AVIATION...MK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
613 PM CST FRI MAR 4 2016 ...AVIATION UPDATE... .SYNOPSIS... ISSUED AT 254 PM CST FRI MAR 4 2016 18Z SFC DATA HAS A WEAK LOW IN NORTHEAST NORTH DAKOTA. A FRONTAL BOUNDARY RAN SOUTH FROM THE LOW INTO NORTHWEST KANSAS. DEW POINTS WERE IN THE TEENS AND 20S ACROSS THE GREAT LAKES WITH 30S ACROSS THE PLAINS. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 254 PM CST FRI MAR 4 2016 AREA RADARS SHOW THE PRECIPITATION IS SLOWLY GETTING BETTER ORGANIZED ACROSS MINNESOTA. THE PRECIPITATION SEEMS TO LINE UP THE BEST WITH THE FORCING ON THE 295K THETA SURFACE BASED ON THE RAP TRENDS. THUS LIGHT RAIN/SPRINKLES SHOULD BEGIN MOVING INTO THE HIGHWAY 20 CORRIDOR WEST OF DUBUQUE BETWEEN 4 AND 6 PM. TONIGHT THE RAP SHOWS THE BEST FORCING ON THE 295K THETA SURFACE RAPIDLY MOVING SOUTHEAST ACROSS THE AREA DURING THE EVENING. THE STRONGER FORCING IS GENERALLY NORTH OF A WATERLOO IOWA TO GALESBURG ILLINOIS LINE. THUS THE BETTER POPS WILL BE NORTH OF THIS LINE. COOLING OF THE ATMOSPHERIC COLUMN WITH SUNSET SHOULD ALLOW A RAIN/SNOW MIX TO DEVELOP THAT MAY BRIEFLY CHANGE OVER TO ALL SNOW NORTHEAST OF A DUBUQUE TO STERLING LINE. ANY SNOWFALL AMOUNTS SHOULD BE WELL UNDER AN INCH. THE RAPID MOVEMENT OF THE FORCING INDICATES PRECIPITATION WILL END ACROSS THE AREA BETWEEN 9 PM AND MIDNIGHT. AFTER MIDNIGHT...SOME LINGERING WEAK FORCING MAY RESULT IN SOME DRIZZLE OR VERY PATCHY FREEZING DRIZZLE IN THE HIGHWAY 20 CORRIDOR BEFORE ENDING. ON SATURDAY...BREEZY CONDITIONS WILL INITIALLY BE SEEN ACROSS THE AREA AS THE STORM SYSTEM MOVES INTO THE EASTERN GREAT LAKES. OTHERWISE EXPECT QUIET AND DRY CONDITIONS WITH ABOVE NORMAL TEMPERATURES. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 254 PM CST FRI MAR 4 2016 SPRING WEATHER WILL BE IN CONTROL THROUGHOUT THE ENTIRE EXTENDED...AND SO WILL LOW LEVEL POPS FOR RAIN SHOWERS. I DO NOT BELIEVE IT WILL RAIN ALL THAT OFTEN IN THE WEEK AHEAD...BUT IN THE WORLD OF BLENDED MODEL DATA...WE ARE OCCASIONALLY RELEGATED TO FORECASTING NEARLY CONTINUOUS LOW RAIN CHANCES...AS MODELS OFFER SLIGHT VARIATIONS ON WHEN RAIN WILL OCCUR. ONE THING IS SOMEWHAT CERTAIN HERE...IT WILL BE MILD...AND DESPITE ANY CLOUDS THE SUSTAINED WARM UP WILL NOT BE HELD BACK ANY LOWER THAN THE 50S GIVEN DEWPOINTS RISING TO THAT LEVEL. RAIN CHANCES APPEAR UNORGANIZED THROUGH MONDAY AS BROAD WARM ADVECTION SPREADS ACROSS THE REGION. MODELS HINT AT BETTER COVERAGE OF RAIN SHOWERS MONDAY NIGHT THROUGH TUESDAY NIGHT...AND POSSIBLY DRY WEATHER AFTER TUESDAY NIGHT. HOWEVER...THE FRONT FORECAST TO BE JUST SOUTHEAST OF THE REGION WEDNESDAY AND THURSDAY IS CLOSE ENOUGH THAT SOME RAIN MAY BRUSH THE SOUTHEAST 1/2 OF THE CWA AT TIMES. THIS IS A VERY LOW CONFIDENCE RAIN CHANCE...THAT MAY IN THE END BE WELL SOUTHEAST OF THE CWA. THIS IS GOOD FOR THE SIMPLE FACT THAT WE NEED FURTHER TIME THIS WEEK TO MELT ANY REMAINING FROST IN THE GROUND PRIOR TO ANY SPRING HEAVY RAINS. THOSE RAINS APPEAR LIKELY TO BRING FLOODING RAINS TO THE MID TO LOWER MISSISSIPPI VALLEY THIS WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 610 PM CST FRI MAR 4 2016 BRIEF MVFR CONDITIONS ARE POSSIBLE UNTIL 05/02Z WITH LIGHT RAIN SOUTH OR SNOW NORTH AS A COOL FRONT PASSES. THEN...SKIES WILL CLEAR BY 05/06Z WITH VFR CONDITIONS AS WINDS SHIFT FROM THE SOUTH AT 5 TO 10 KTS TO THE NORTHWEST AT 10 TO 20 KTS THROUGH SATURDAY. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...08 SHORT TERM...08 LONG TERM...ERVIN AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1020 AM MST THU MAR 3 2016 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 200 AM MST THU MAR 3 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS LARGE SCALE RIDGING IN PLACE ACROSS THE WESTERN US WITH NW FLOW ACROSS THE ROCKIES INTO THE PLAINS. SHORTWAVE TROUGHS OVER NORTHEAST KANSAS AND ANOTHER OVER WESTERN NEBRASKA. CONFLUENT FLOW AND ASSOCIATED SUBSIDENCE IS SPREADING SOUTH INTO NORTHEAST COLORADO AND NORTHWEST KANSAS AS THE SECOND SHORTWAVE TRANSITIONS EAST AND SHORTWAVE RIDGING BUILDS TOWARDS THE REGION. AT THE SURFACE A COLD FRONT HAS COMPLETELY PUSHED THROUGH OUR CWA WITH HIGH PRESSURE BUILDING SOUTHEAST FROM COLORADO AND THE NEBRASKA PANHANDLE. THERE IS STILL TIGHT GRADIENT IN PLACE IMMEDIATELY BEHIND THE FRONT IN OUR EASTERN CWA DUE TO A MESO LOW APPEARS TO HAVE DEVELOPED IN NORTHCENTRAL/NORTHEAST KANSAS. TODAY-SATURDAY NIGHT...NORTHWEST TO WESTERLY FLOW WILL CONTINUE WITH A SERIES OF SHORTWAVE RIDGES AND TROUGHS MOVING ACROSS THE PLAINS. ANOMALOUSLY HIGH 500MB HEIGHTS REMAIN IN PLACE THROUGH THESE PERIODS...SO WHILE THERE MAY BE A FEW REINFORCING COLD FRONTS MOVING INTO OUR CWA...ABOVE NORMAL TEMPERATURES WILL CONTINUE. MOISTURE PROFILES REMAIN VERY DRY ON ALL GUIDANCE...SO DESPITE A FRONTAL PASSAGE FRIDAY AND A STRONGER SHORTWAVE APPROACHING THE REGION SATURDAY NIGHT DRY WEATHER SHOULD CONTINUE. NAM/SREF ARE ALSO HINTING AT POSSIBLE STRATUS/FOG DEVELOPMENT WITH MOIST RETURN FLOW SATURDAY NIGHT. BL/SURFACE WINDS AND PROJECTED SURFACE DEWPOINT DEPRESSIONS APPEAR TO FAVOR STRATUS...AND I DECIDED AGAINST ADDING FOG MENTION. A CHANGE I MADE DURING THIS UPDATE WAS TO TREND HIGH TEMPS DOWN A LITTLE FROM PREVIOUS FORECAST FRIDAY AS FRONT ALREADY APPEARS TO BE THROUGH MOST OF OUR CWA BY 18Z AND CLOUD COVER MAY BE A BIT MORE OPAQUE/EXTENSIVE. THIS STILL RESULTS IN ABOVE NORMAL HIGHS RANGING FROM AROUND 70F IN OUR SOUTH TO MID 60S IN OUR NORTH. .LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT) ISSUED AT 200 AM MST THU MAR 3 2016 SUNDAY-SUNDAY NIGHT...MID AND HIGH CLOUDS MOVE THROUGH FROM THE SOUTHWEST DURING THE MORNING WITH DECREASING COVERAGE FROM SOUTHWEST TO NORTHEAST DURING THE AFTERNOON. SIMILAR EXPECTATIONS SUNDAY NIGHT...INCREASING CLOUDS THROUGH MIDNIGHT WITH DECREASING CLOUDS AFTERWORD. THIS IS ALL AHEAD OF AN APPROACHING UPPER TROUGH. AFTERNOON TEMPERATURES WILL WARM INTO THE LOW 70S...POSSIBLY A FEW MID 70S IF FULL 850MB MIXING OCCURS. THIS IS AROUND 20+ DEGREES ABOVE NORMAL. LOW TEMPERATURES ALSO VERY MILD WITH MID 30S TO MID 40S (WEST TO EAST). MONDAY-MONDAY NIGHT...SLIGHTLY NEGATIVELY TILTED UPPER TROUGH MOVES INTO THE AREA FROM THE SOUTHWEST MONDAY AFTERNOON THEN LIFTING OUT OF THE AREA MONDAY EVENING. EXTENSIVE CLOUDINESS MOVES IN FROM THE WEST BEHIND THE SYSTEM AND SURFACE COLD FRONT DURING THE AFTERNOON...SPREADING EAST OVERNIGHT. THERE WILL BE A CHANCE FOR RAIN SHOWERS ALONG AND BEHIND THE FRONT FROM EARLY TO MID MORNING THROUGH THE AFTERNOON. AS COLDER AIR MOVES IN DURING THE EVENING AND OVERNIGHT HOURS SOME LIGHT SNOW IS POSSIBLE. WIDE RANGE IN AFTERNOON TEMPERATURES WITH LOW TO MID 60S IN FAR EASTERN COLORADO...LOW 70S FROM NEAR MCCOOK TO LEOTI EAST...ALL DEPENDENT ON COLD FRONT AND CLOUD ARRIVAL. LOW TEMPERATURES GENERALLY IN THE LOW 30S TO AROUND 40 (WEST TO EAST). ANOTHER ITEM THAT WILL NEED TO BE MONITORED WILL BE FIRE WEATHER THREAT AS HUMIDITY VALUES FALL BELOW 20 PERCENT ACROSS GREELEY AND WICHITA COUNTIES. WINDS DURING THE TIME OF LOWEST HUMIDITY LOOK TO BE FROM THE WEST AROUND 15KTS OR SO AND POSSIBLY GUSTY...CREATING A BORDERLINE CASE FOR A FIRE WEATHER HIGHLIGHT. TUESDAY-TUESDAY NIGHT...HIGH PRESSURE BUILDS IN FROM THE NORTH ALLOWING COOLER AIR TO MOVE IN. AFTERNOON TEMPERATURES IN THE LOW/MID 50S TO LOW 60S LOOKS GOOD PER 850MB TEMPERATURES AND IS STILL A FEW DEGREES ABOVE NORMAL. LOWS IN THE UPPER 20S TO MID 30S. EXTENDED PROCEDURE GENERATED SOME SLIGHT CHANCE POPS TUESDAY NIGHT FOR THE SOUTHEAST 1/2 OR SO OF THE AREA. THERE IS SOME MOISTURE IN THE 850-500MB LAYER IN THAT AREA BUT IT LOOKS RATHER LIMITED AND MAY BE WHY MODELS DONT GENERATE ANY MOISTURE FROM IT. WILL KEEP A MENTION OF IT FOR NOW BUT IT DOESNT LOOK VERY IMPRESSIVE. WEDNESDAY-WEDNESDAY NIGHT...EXTENDED PROCEDURE POPULATED THE WEDNESDAY DAY PERIOD WITH SLIGHT CHANCE POPS ALONG THE SAME SOUTHEAST PORTION OF THE AREA AS TUESDAY NIGHT. AGAIN...RIGHT NOW MOISTURE DOESNT APPEAR ENOUGH TO WARRANT THE SLIGHT CHANCE POPS. PER COORDINATION WITH NEIGHBORS IMPACTED BY THE POPS WILL KEEP IT IN FOR NOW. OTHERWISE SHOULD SEE QUITE A BIT OF SUNSHINE WITH A MOSTLY CLEAR SKY OVERNIGHT. HIGH TEMPERATURES IN THE LOW TO UPPER 50S WITH LOWS IN THE UPPER 20S TO LOW 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1017 AM MST THU MAR 3 2016 VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD DUE TO AN UPPER LEVEL RIDGE WHICH WILL MOVE OUT OF THE CENTRAL ROCKIES AND ACROSS THE ADJACENT HIGH PLAINS. BREEZY SURFACE WINDS EARLY THIS AFTERNOON WILL DIMINISH BY MID AFTERNOON. && .FIRE WEATHER... ISSUED AT 200 AM MST THU MAR 3 2016 RH MAY DROP BELOW 20 PERCENT THIS AFTERNOON IN OUR WEST AND AGAIN FRIDAY AND SATURDAY IN OUR SOUTH. ANY GUSTY WINDS TODAY WILL BE IN THE MORNING IMMEDIATELY AFTER SUNRISE WITH DECREASING PRESSURE GRADIENT THROUGH MIDDAY AND LOWER RH VALUES IN THE AFTERNOON...SO CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED. WINDS SHOULD BE STRONG ENOUGH FRIDAY BEHIND THE FRONTAL PASSAGE...HOWEVER IT DOESNT APPEAR LIKELY THAT 3HR CRITERIA WOULD BE MET DUE TO MARGINAL RH VALUES OVER MOST OF THE REGION. IT COULD BE CLOSE IN OUR FAR SOUTH IF TEMPS ARE A BIT WARMER. IF LOWER TDS ARE ABLE TO MIX SATURDAY WE COULD SEE RED FLAG CONDITIONS MET OVER WESTERN PORTIONS OF OUR CWA. AT THIS TIME MOST GUIDANCE IS KEEPING RH JUST ABOVE CRITERIA. THESE PERIODS WILL NEED TO BE MONITORED...BUT NO WATCHES/WARNINGS ARE PLANNED AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...024 FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
411 AM MST THU MAR 3 2016 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 200 AM MST THU MAR 3 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS LARGE SCALE RIDGING IN PLACE ACROSS THE WESTERN US WITH NW FLOW ACROSS THE ROCKIES INTO THE PLAINS. SHORTWAVE TROUGHS OVER NORTHEAST KANSAS AND ANOTHER OVER WESTERN NEBRASKA. CONFLUENT FLOW AND ASSOCIATED SUBSIDENCE IS SPREADING SOUTH INTO NORTHEAST COLORADO AND NORTHWEST KANSAS AS THE SECOND SHORTWAVE TRANSITIONS EAST AND SHORTWAVE RIDGING BUILDS TOWARDS THE REGION. AT THE SURFACE A COLD FRONT HAS COMPLETELY PUSHED THROUGH OUR CWA WITH HIGH PRESSURE BUILDING SOUTHEAST FROM COLORADO AND THE NEBRASKA PANHANDLE. THERE IS STILL TIGHT GRADIENT IN PLACE IMMEDIATELY BEHIND THE FRONT IN OUR EASTERN CWA DUE TO A MESO LOW APPEARS TO HAVE DEVELOPED IN NORTHCENTRAL/NORTHEAST KANSAS. TODAY-SATURDAY NIGHT...NORTHWEST TO WESTERLY FLOW WILL CONTINUE WITH A SERIES OF SHORTWAVE RIDGES AND TROUGHS MOVING ACROSS THE PLAINS. ANOMALOUSLY HIGH 500MB HEIGHTS REMAIN IN PLACE THROUGH THESE PERIODS...SO WHILE THERE MAY BE A FEW REINFORCING COLD FRONTS MOVING INTO OUR CWA...ABOVE NORMAL TEMPERATURES WILL CONTINUE. MOISTURE PROFILES REMAIN VERY DRY ON ALL GUIDANCE...SO DESPITE A FRONTAL PASSAGE FRIDAY AND A STRONGER SHORTWAVE APPROACHING THE REGION SATURDAY NIGHT DRY WEATHER SHOULD CONTINUE. NAM/SREF ARE ALSO HINTING AT POSSIBLE STRATUS/FOG DEVELOPMENT WITH MOIST RETURN FLOW SATURDAY NIGHT. BL/SURFACE WINDS AND PROJECTED SURFACE DEWPOINT DEPRESSIONS APPEAR TO FAVOR STRATUS...AND I DECIDED AGAINST ADDING FOG MENTION. A CHANGE I MADE DURING THIS UPDATE WAS TO TREND HIGH TEMPS DOWN A LITTLE FROM PREVIOUS FORECAST FRIDAY AS FRONT ALREADY APPEARS TO BE THROUGH MOST OF OUR CWA BY 18Z AND CLOUD COVER MAY BE A BIT MORE OPAQUE/EXTENSIVE. THIS STILL RESULTS IN ABOVE NORMAL HIGHS RANGING FROM AROUND 70F IN OUR SOUTH TO MID 60S IN OUR NORTH. .LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT) ISSUED AT 200 AM MST THU MAR 3 2016 SUNDAY-SUNDAY NIGHT...MID AND HIGH CLOUDS MOVE THROUGH FROM THE SOUTHWEST DURING THE MORNING WITH DECREASING COVERAGE FROM SOUTHWEST TO NORTHEAST DURING THE AFTERNOON. SIMILAR EXPECTATIONS SUNDAY NIGHT...INCREASING CLOUDS THROUGH MIDNIGHT WITH DECREASING CLOUDS AFTERWORD. THIS IS ALL AHEAD OF AN APPROACHING UPPER TROUGH. AFTERNOON TEMPERATURES WILL WARM INTO THE LOW 70S...POSSIBLY A FEW MID 70S IF FULL 850MB MIXING OCCURS. THIS IS AROUND 20+ DEGREES ABOVE NORMAL. LOW TEMPERATURES ALSO VERY MILD WITH MID 30S TO MID 40S (WEST TO EAST). MONDAY-MONDAY NIGHT...SLIGHTLY NEGATIVELY TILTED UPPER TROUGH MOVES INTO THE AREA FROM THE SOUTHWEST MONDAY AFTERNOON THEN LIFTING OUT OF THE AREA MONDAY EVENING. EXTENSIVE CLOUDINESS MOVES IN FROM THE WEST BEHIND THE SYSTEM AND SURFACE COLD FRONT DURING THE AFTERNOON...SPREADING EAST OVERNIGHT. THERE WILL BE A CHANCE FOR RAIN SHOWERS ALONG AND BEHIND THE FRONT FROM EARLY TO MID MORNING THROUGH THE AFTERNOON. AS COLDER AIR MOVES IN DURING THE EVENING AND OVERNIGHT HOURS SOME LIGHT SNOW IS POSSIBLE. WIDE RANGE IN AFTERNOON TEMPERATURES WITH LOW TO MID 60S IN FAR EASTERN COLORADO...LOW 70S FROM NEAR MCCOOK TO LEOTI EAST...ALL DEPENDENT ON COLD FRONT AND CLOUD ARRIVAL. LOW TEMPERATURES GENERALLY IN THE LOW 30S TO AROUND 40 (WEST TO EAST). ANOTHER ITEM THAT WILL NEED TO BE MONITORED WILL BE FIRE WEATHER THREAT AS HUMIDITY VALUES FALL BELOW 20 PERCENT ACROSS GREELEY AND WICHITA COUNTIES. WINDS DURING THE TIME OF LOWEST HUMIDITY LOOK TO BE FROM THE WEST AROUND 15KTS OR SO AND POSSIBLY GUSTY...CREATING A BORDERLINE CASE FOR A FIRE WEATHER HIGHLITE. TUESDAY-TUESDAY NIGHT...HIGH PRESSURE BUILDS IN FROM THE NORTH ALLOWING COOLER AIR TO MOVE IN. AFTERNOON TEMPERATURES IN THE LOW/MID 50S TO LOW 60S LOOKS GOOD PER 850MB TEMPERATURES AND IS STILL A FEW DEGREES ABOVE NORMAL. LOWS IN THE UPPER 20S TO MID 30S. EXTENDED PROCEDURE GENERATED SOME SLIGHT CHANCE POPS TUESDAY NIGHT FOR THE SOUTHEAST 1/2 OR SO OF THE AREA. THERE IS SOME MOISTURE IN THE 850-500MB LAYER IN THAT AREA BUT IT LOOKS RATHER LIMITED AND MAY BE WHY MODELS DONT GENERATE ANY MOISTURE FROM IT. WILL KEEP A MENTION OF IT FOR NOW BUT IT DOESNT LOOK VERY IMPRESSIVE. WEDNESDAY-WEDNESDAY NIGHT...EXTENDED PROCEDURE POPULATED THE WEDNESDAY DAY PERIOD WITH SLIGHT CHANCE POPS ALONG THE SAME SOUTHEAST PORTION OF THE AREA AS TUESDAY NIGHT. AGAIN...RIGHT NOW MOISTURE DOESNT APPEAR ENOUGH TO WARRANT THE SLIGHT CHANCE POPS. PER COORDINATION WITH NEIGHBORS IMPACTED BY THE POPS WILL KEEP IT IN FOR NOW. OTHERWISE SHOULD SEE QUITE A BIT OF SUNSHINE WITH A MOSTLY CLEAR SKY OVERNIGHT. HIGH TEMPERATURES IN THE LOW TO UPPER 50S WITH LOWS IN THE UPPER 20S TO LOW 30S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 411 AM MST THU MAR 3 2016 VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD AT KGLD AND KMCK TERMINALS THROUGH THE TAF PERIOD. FOG MAY DEVELOP OVER SOUTH CENTRAL NEBRASKA BY FRIDAY MORNING AS INDICATED BY SREF/NAM...HOWEVER EVEN IF THIS WERE TO OCCUR IT LOOKS TO REMAIN EAST OF KMCK. A BRIEF PERIOD OF GUSTY WEST-NORTHWEST WINDS WILL BE POSSIBLE THIS MORNING AS LLJ TRANSITIONS EAST. BEST CHANCE FOR GUSTS IS CURRENTLY AT KMCK...THOUGH I COULDNT RULE OUT A FEW GUSTS 15-18KT AT KGLD AS WELL. WINDS SHOULD DECREASE BY MIDDAY WITH SOUTH TO SOUTHEAST WINDS BELOW 12KT DEVELOPING THIS EVENING AS SURFACE LOW PRESSURE REDEVELOPS IN EASTERN COLORADO. && .FIRE WEATHER... ISSUED AT 200 AM MST THU MAR 3 2016 RH MAY DROP BELOW 20 PERCENT THIS AFTERNOON IN OUR WEST AND AGAIN FRIDAY AND SATURDAY IN OUR SOUTH. ANY GUSTY WINDS TODAY WILL BE IN THE MORNING IMMEDIATELY AFTER SUNRISE WITH DECREASING PRESSURE GRADIENT THROUGH MIDDAY AND LOWER RH VALUES IN THE AFTERNOON...SO CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED. WINDS SHOULD BE STRONG ENOUGH FRIDAY BEHIND THE FRONTAL PASSAGE...HOWEVER IT DOESNT APPEAR LIKELY THAT 3HR CRITERIA WOULD BE MET DUE TO MARGINAL RH VALUES OVER MOST OF THE REGION. IT COULD BE CLOSE IN OUR FAR SOUTH IF TEMPS ARE A BIT WARMER. IF LOWER TDS ARE ABLE TO MIX SATURDAY WE COULD SEE RED FLAG CONDITIONS MET OVER WESTERN PORTIONS OF OUR CWA. AT THIS TIME MOST GUIDANCE IS KEEPING RH JUST ABOVE CRITERIA. THESE PERIODS WILL NEED TO BE MONITORED...BUT NO WATCHES/WARNINGS ARE PLANNED AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...DR FIRE WEATHER...DR
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
510 AM CST THU MAR 3 2016 ...Updated Aviation Discussion... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 245 AM CST THU MAR 3 2016 In the wake of an upper level disturbance and associated cold front. skies will clear out this morning with weak surface high pressure building into western Kansas today. As the flow becomes more zonal at mid levels across the Rockies by tonight, surface troughing will develop in the lee of the Rockies, with a resumption of south winds. Highs today should be in the lower to middle 60s, with mainly lower to middle 30s tonight. Temperatures will be held up tonight by the increasing south winds. .LONG TERM...(Friday THROUGH Wednesday) ISSUED AT 245 AM CST THU MAR 3 2016 The mid to upper level pattern will remain fairly zonal through Saturday across the Rockies and plains before the next upper level trough amplifies across the Rockies Sunday and ejects into the plains in a progressive manner by Monday. After a warm day Friday ahead of a weak cold front with highs in the 70s, highs Saturday should reach into the mid to upper 60s. Gulf moisture will surge into the plains ahead of the upper level trough, but most if not all of the shower and thunderstorm activity is expected to be off to the east in south central Kansas and points southward from there from Sunday into Monday. Medicine Lodge and Pratt will be on the western edge of the small precipitation chances. After a warm day Sunday with highs in the 70s, Monday ought to be a mild day as well ahead of the front with downslope flow and highs in the 70s. Fire weather may be a consideration Monday if the frontal timing is favorable and stronger southwest winds and dry air materialize. This system will push a weak cold front through western Kansas Monday night. Another stronger upper level storm system is expected to move into the southwestern United States by Tuesday and into south Texas by Wednesday, which may be too far south for significant precipitation across western Kansas. Nevertheless, the gridded forecast does indicated small chance of showers and thunderstorms Tuesday into Tuesday night with small chances for showers lingering into Wednesday. Given the weakness of the aforementioned cold front passing Monday night, high temperatures are still expected to be in the upper 50s and lower 60s for Tuesday through Thursday. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING) ISSUED AT 508 AM CST THU MAR 3 2016 Gusty northwest winds returning by late morning will fall back to around 10 knots after 21z Thursday as an area of high pressure at the surface builds south southeast across western Kansas. After 00z Friday these light winds will back to the south as the surface high moves into Oklahoma and a trough of low pressure at the surface develops along the lee of the Rockies. NAM BUFR soundings, RAP and HRRR indicating VFR conditions over the next 24 hours. && .PRELIMINARY POINT TEMPS/POPS... DDC 63 36 73 37 / 0 0 0 0 GCK 63 36 72 35 / 0 0 0 0 EHA 65 40 73 37 / 0 0 0 0 LBL 65 36 75 36 / 0 0 0 0 HYS 60 35 70 36 / 0 0 0 0 P28 65 33 73 40 / 0 0 0 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Finch LONG TERM...Finch AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
338 AM CST THU MAR 3 2016 .SHORT TERM...(Today and Tonight) Issued at 334 AM CST THU MAR 3 2016 Early this morning a shortwave trough was embedded within the northwesterly flow aloft, with water vapor imagery showing this wave clipping northeast Kansas. This passing wave helped to push surface low pressure into the area with a cold front advancing out of the forecast area. There was enough lift and mid-level moisture from this frontal passage and shortwave trough to support scattered showers and isolated thunderstorms last night through early this morning. Short-range models show these scattered showers gradually becoming more widely scattered before eventually dissipating around or shortly after sunrise this morning. Mid-level cloud cover will stick around through mid morning before quickly scattering out and making way for mostly sunny skies by this afternoon. Northwesterly winds will prevail as a result of the early morning frontal passage, with enough of a pressure gradient in place to support gusts of 20- 30mph late morning into early this afternoon. These northwesterly winds will support some cold air advection, keeping temperatures cooler than yesterday with afternoon highs only reaching into the low/mid 50s. Surface high pressure will track eastward over the forecast area late this afternoon through tonight, causing winds to shift to the southeast by Friday morning. The combination of mostly clear skies and light winds will support decent radiational cooling and low temperatures dropping into the upper 20s to low 30s tonight. .LONG TERM...(Friday through Wednesday) Issued at 334 AM CST THU MAR 3 2016 Friday will see dry conditions with broad upper level ridging in place. Most guidance seems to have been fairly consistent over the past few days hinting at the set up for dry conditions to cause elevated fire weather concerns over northeastern Kansas in the afternoon Friday as southwest flow at the surface through the mid levels sets up in response to a lee side trough in place. Although some high clouds will likely be in place, the atmosphere remains very dry and will likely mix down some of the dry air to the surface. As temps rise in the afternoon with dry adibatic conditions being the rule, expect winds to gust as high as 30mph. As models tend to do this time of year, the RH values may not have been low enough. Therefore, lowered dewpoints a degree or two for Friday afternoon while also increasing the temps by just about the same. This seems like the likely scenario given the synoptic set up in place and fairly strong subsidence in place. Saturday remains very dry, but slightly cooler with a dry cold frontal passage having taken place. Winds will not be a concern as they should shift to the northeast and be light enough to not create as elevated of a fire danger concern. Into the extended period beginning Sunday afternoon time frame, fire weather concerns subside as the switch over to possible thunderstorms takes place with a fairly good amount of WAA beginning to draw up a good moisture plume for this time of year. Dewpoints in the mid 50s could be in place by Monday afternoon. The first shortwave emerging out of the Central Rockies on Sunday ahead of larger wave trough digging over the Western CONUS into the Desert Southwest will help to begin to draw this better moisture north from the Gulf. The ECMWF is a bit more agressive with the overall system as well as deeper, so have essentially compromised in the long term with the GFS as there were no major initialization concerns. Into Sunday afternoon, this lead shortwave will cause isentropic ascent over southeastern KS and possibly have enough lift and moisture advection to begin light precip in the form of rain as the atmosphere continues to saturate. Have kept mention of thunder in the forecast generally into Monday and Tuesday over northeastern KS as deep moisture continues to build into the region ahead of a second major shortwave with a narrow axis of instability working through the region. While shear profiles increase and a fairly nice dryline also works toward the region, the atmosphere still appears to be capped but given the deepening low and continued WAA in place, perhaps enough factors may come together to erode the cap and cause a few thunderstorms to form. Whether these would be severe or not remains to be seen at this point. Again, the better dynamics at this point seem to be positioned further south over the Southern Plains and if anything, the trend with models has been pushing further south with the southern branch of the jet stream. && .AVIATION...(For the 06Z TAFS through 06Z Friday) Issued at 1103 PM CST WED MAR 2 2016 VFR conditions are expect to persist through the night as some dry air remains in the low levels. The one potential wrench in this forecast is the NAM showing a brief period of MVFR CIGS around 12Z. The RAP and GFS are a little less obvious in the RH progs and there aren`t a lot of low clouds upstream across eastern NEB or western IA. Therefore have maintained a VFR forecast and will monitor trends. Precip timing is based on the latest HRRR/RAP/NAM consensus, which fits in fairly well with the prev forecast. Impact from the light showers at the terminals is expected to be minor with conditions remaining VFR. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Hennecke LONG TERM...Drake AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
201 AM MST THU MAR 3 2016 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 200 AM MST THU MAR 3 2016 EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS LARGE SCALE RIDGING IN PLACE ACROSS THE WESTERN US WITH NW FLOW ACROSS THE ROCKIES INTO THE PLAINS. SHORTWAVE TROUGHS OVER NORTHEAST KANSAS AND ANOTHER OVER WESTERN NEBRASKA. CONFLUENT FLOW AND ASSOCIATED SUBSIDENCE IS SPREADING SOUTH INTO NORTHEAST COLORADO AND NORTHWEST KANSAS AS THE SECOND SHORTWAVE TRANSITIONS EAST AND SHORTWAVE RIDGING BUILDS TOWARDS THE REGION. AT THE SURFACE A COLD FRONT HAS COMPLETELY PUSHED THROUGH OUR CWA WITH HIGH PRESSURE BUILDING SOUTHEAST FROM COLORADO AND THE NEBRASKA PANHANDLE. THERE IS STILL TIGHT GRADIENT IN PLACE IMMEDIATELY BEHIND THE FRONT IN OUR EASTERN CWA DUE TO A MESO LOW APPEARS TO HAVE DEVELOPED IN NORTHCENTRAL/NORTHEAST KANSAS. TODAY-SATURDAY NIGHT...NORTHWEST TO WESTERLY FLOW WILL CONTINUE WITH A SERIES OF SHORTWAVE RIDGES AND TROUGHS MOVING ACROSS THE PLAINS. ANOMALOUSLY HIGH 500MB HEIGHTS REMAIN IN PLACE THROUGH THESE PERIODS...SO WHILE THERE MAY BE A FEW REINFORCING COLD FRONTS MOVING INTO OUR CWA...ABOVE NORMAL TEMPERATURES WILL CONTINUE. MOISTURE PROFILES REMAIN VERY DRY ON ALL GUIDANCE...SO DESPITE A FRONTAL PASSAGE FRIDAY AND A STRONGER SHORTWAVE APPROACHING THE REGION SATURDAY NIGHT DRY WEATHER SHOULD CONTINUE. NAM/SREF ARE ALSO HINTING AT POSSIBLE STRATUS/FOG DEVELOPMENT WITH MOIST RETURN FLOW SATURDAY NIGHT. BL/SURFACE WINDS AND PROJECTED SURFACE DEWPOINT DEPRESSIONS APPEAR TO FAVOR STRATUS...AND I DECIDED AGAINST ADDING FOG MENTION. A CHANGE I MADE DURING THIS UPDATE WAS TO TREND HIGH TEMPS DOWN A LITTLE FROM PREVIOUS FORECAST FRIDAY AS FRONT ALREADY APPEARS TO BE THROUGH MOST OF OUR CWA BY 18Z AND CLOUD COVER MAY BE A BIT MORE OPAQUE/EXTENSIVE. THIS STILL RESULTS IN ABOVE NORMAL HIGHS RANGING FROM AROUND 70F IN OUR SOUTH TO MID 60S IN OUR NORTH. .LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT) ISSUED AT 200 AM MST THU MAR 3 2016 SUNDAY-SUNDAY NIGHT...MID AND HIGH CLOUDS MOVE THROUGH FROM THE SOUTHWEST DURING THE MORNING WITH DECREASING COVERAGE FROM SOUTHWEST TO NORTHEAST DURING THE AFTERNOON. SIMILAR EXPECTATIONS SUNDAY NIGHT...INCREASING CLOUDS THROUGH MIDNIGHT WITH DECREASING CLOUDS AFTERWORD. THIS IS ALL AHEAD OF AN APPROACHING UPPER TROUGH. AFTERNOON TEMPERATURES WILL WARM INTO THE LOW 70S...POSSIBLY A FEW MID 70S IF FULL 850MB MIXING OCCURS. THIS IS AROUND 20+ DEGREES ABOVE NORMAL. LOW TEMPERATURES ALSO VERY MILD WITH MID 30S TO MID 40S (WEST TO EAST). MONDAY-MONDAY NIGHT...SLIGHTLY NEGATIVELY TILTED UPPER TROUGH MOVES INTO THE AREA FROM THE SOUTHWEST MONDAY AFTERNOON THEN LIFTING OUT OF THE AREA MONDAY EVENING. EXTENSIVE CLOUDINESS MOVES IN FROM THE WEST BEHIND THE SYSTEM AND SURFACE COLD FRONT DURING THE AFTERNOON...SPREADING EAST OVERNIGHT. THERE WILL BE A CHANCE FOR RAIN SHOWERS ALONG AND BEHIND THE FRONT FROM EARLY TO MID MORNING THROUGH THE AFTERNOON. AS COLDER AIR MOVES IN DURING THE EVENING AND OVERNIGHT HOURS SOME LIGHT SNOW IS POSSIBLE. WIDE RANGE IN AFTERNOON TEMPERATURES WITH LOW TO MID 60S IN FAR EASTERN COLORADO...LOW 70S FROM NEAR MCCOOK TO LEOTI EAST...ALL DEPENDENT ON COLD FRONT AND CLOUD ARRIVAL. LOW TEMPERATURES GENERALLY IN THE LOW 30S TO AROUND 40 (WEST TO EAST). ANOTHER ITEM THAT WILL NEED TO BE MONITORED WILL BE FIRE WEATHER THREAT AS HUMIDITY VALUES FALL BELOW 20 PERCENT ACROSS GREELEY AND WICHITA COUNTIES. WINDS DURING THE TIME OF LOWEST HUMIDITY LOOK TO BE FROM THE WEST AROUND 15KTS OR SO AND POSSIBLY GUSTY...CREATING A BORDERLINE CASE FOR A FIRE WEATHER HIGHLITE. TUESDAY-TUESDAY NIGHT...HIGH PRESSURE BUILDS IN FROM THE NORTH ALLOWING COOLER AIR TO MOVE IN. AFTERNOON TEMPERATURES IN THE LOW/MID 50S TO LOW 60S LOOKS GOOD PER 850MB TEMPERATURES AND IS STILL A FEW DEGREES ABOVE NORMAL. LOWS IN THE UPPER 20S TO MID 30S. EXTENDED PROCEDURE GENERATED SOME SLIGHT CHANCE POPS TUESDAY NIGHT FOR THE SOUTHEAST 1/2 OR SO OF THE AREA. THERE IS SOME MOISTURE IN THE 850-500MB LAYER IN THAT AREA BUT IT LOOKS RATHER LIMITED AND MAY BE WHY MODELS DONT GENERATE ANY MOISTURE FROM IT. WILL KEEP A MENTION OF IT FOR NOW BUT IT DOESNT LOOK VERY IMPRESSIVE. WEDNESDAY-WEDNESDAY NIGHT...EXTENDED PROCEDURE POPULATED THE WEDNESDAY DAY PERIOD WITH SLIGHT CHANCE POPS ALONG THE SAME SOUTHEAST PORTION OF THE AREA AS TUESDAY NIGHT. AGAIN...RIGHT NOW MOISTURE DOESNT APPEAR ENOUGH TO WARRANT THE SLIGHT CHANCE POPS. PER COORDINATION WITH NEIGHBORS IMPACTED BY THE POPS WILL KEEP IT IN FOR NOW. OTHERWISE SHOULD SEE QUITE A BIT OF SUNSHINE WITH A MOSTLY CLEAR SKY OVERNIGHT. HIGH TEMPERATURES IN THE LOW TO UPPER 50S WITH LOWS IN THE UPPER 20S TO LOW 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1027 PM MST WED MAR 2 2016 VFR CONDITIONS EXPECTED FOR BOTH TAF SITES...WITH FEW-SCT120-250. WINDS WNW 10-20KTS WITH GUSTS NEAR 30 KTS THRU 22Z...THEN NW AROUND 10 KTS. BY 02Z FRIDAY...MAINLY SW AROUND 10 KTS. && .FIRE WEATHER... ISSUED AT 200 AM MST THU MAR 3 2016 RH MAY DROP BELOW 20 PERCENT THIS AFTERNOON IN OUR WEST AND AGAIN FRIDAY AND SATURDAY IN OUR SOUTH. ANY GUSTY WINDS TODAY WILL BE IN THE MORNING IMMEDIATELY AFTER SUNRISE WITH DECREASING PRESSURE GRADIENT THROUGH MIDDAY AND LOWER RH VALUES IN THE AFTERNOON...SO CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED. WINDS SHOULD BE STRONG ENOUGH FRIDAY BEHIND THE FRONTAL PASSAGE...HOWEVER IT DOESNT APPEAR LIKELY THAT 3HR CRITERIA WOULD BE MET DUE TO MARGINAL RH VALUES OVER MOST OF THE REGION. IT COULD BE CLOSE IN OUR FAR SOUTH IF TEMPS ARE A BIT WARMER. IF LOWER TDS ARE ABLE TO MIX SATURDAY WE COULD SEE RED FLAG CONDITIONS MET OVER WESTERN PORTIONS OF OUR CWA. AT THIS TIME MOST GUIDANCE IS KEEPING RH JUST ABOVE CRITERIA. THESE PERIODS WILL NEED TO BE MONITORED...BUT NO WATCHES/WARNINGS ARE PLANNED AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...JN FIRE WEATHER...DR
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1103 PM CST WED MAR 2 2016 ...AVIATION UPDATE... .SHORT TERM...(This Evening through Thursday) Issued at 313 PM CST WED MAR 2 2016 The strong pressure gradient and associated low level jet will relax this evening causing the winds to diminish. In the meantime deep mixing has occurred across east central KS, and red flag criteria has been met. Therefore the red flag warning will continue until 6 pm this evening. Later tonight a few weak shortwaves will track southeastward across the area. The waves will bring steep mid level lapse rates and some weak isentropic lift. The steep lapse rates along with mid level moisture will support elevated cape on the order of 200 j/kg right ahead of the waves. High based showers with some embedded thunder could form in north central KS this evening and move eastward and southeastward overnight. Most of the models are indicating at least some precip across the area, but these showers appear scattered in nature and will only produce light amounts. Especially given the deep mixing and low level dry air in place. A cold front will also sweep through the area shifting the winds to the northwest by sunrise tomorrow. Wind gusts 20 to 30 mph will occur behind the front and persist through the morning. A second slightly stronger shortwave will track over the area behind the initial wave during the late morning. Although this secondary wave appears to be competing with some isentropic downglide therefore it may be difficult to form any precip. If any showers were to form it would most likely take place around sunrise and be more isolated. Low temperatures tonight will be in the mid 30s to lower 40s, while highs tomorrow only reach the 50s. .LONG TERM...(Thursday Night through Wednesday) Issued at 313 PM CST WED MAR 2 2016 Thursday night through Saturday night, the upper pattern will be progressive with a southern stream upper ridge moving east across the southern and central plains on Friday. A lee surface trough will deepen across the southern high plains and will cause southerly winds to increase to 15 to 25 MPH across eastern KS. Highs will warm into the lower to mid 60s Friday afternoon. An upper level trough will round the upper ridge axis across southern Canada, then did southeast across the upper midwest and Great Lakes states. Low-level cold air advection will cause a weak cold front to push southward across the CWA Friday night. North winds of 10 to 20 MPH during the morning will become light by afternoon. Highs will warm once again into the lower to mid 60s. Sunday through Wednesday, An intense upper level trough will amplify across the southwest US and will eventually move east across central TX on Wednesday. Ahead of this amplified trough a few lead short wave troughs will lift northeast across the southern and central plains. The first lead upper trough will lift northeast across KS and OK on Sunday. Ahead of the trough deeper gulf moisture will return northward increasing isentropic lift late Saturday night and Sunday morning and may provide the CWA with a chance for elevated thunderstorms. The scattered showers and thunderstorms may last through the day due to increased ascent ahead of the first lead upper trough and deeper moisture return. Southerly winds will keep temperatures mild despite cloud cover and chances for showers and thunderstorms. Highs will reach the lower to mid 60s. Monday, a more amplified lead trough will lift northeast from the four corners region into western KS by Monday afternoon. The ECMWF shows the deeper gulf moisture will be in place ahead of a surface dryline that will move into central KS. If skies clear and instability increases ahead of the dryline, then we could see strong to potentially severe thunderstorms develop across central and north central KS ahead of the surface dryline. The GFS model veers the 850mb and surface winds ahead of the lead H5 trough, which would reduce the low-level vertical wind shear. Timing and the possibility of keeping cloud cover through the day Monday may negate the potential for severe thunderstorms development across the CWA. Monday will be warmer with the stronger WAA. Highs on Monday should reach the lower to mid 70s. If we see more insolation through the late morning and early afternoon hours, highs may reach into the upper 70s to near 80 degrees. Monday night through Tuesday night, The deep upper low across southern AZ move east into far west TX. A weak cold front that will move southeast of the CWA will become stationary, while 850mb winds back to the south and transport deeper moisture north of the surface boundary. The resulting isentropic lift along with ascent ahead of a 50 to 60 KT H5 jet max will provide periods of showers and thunderstorms through the period. northwest winds and periods of showers and thunderstorms will keep temperatures cooler in the lower to mid 60s. Wednesday, the deep upper low will slowly move east into west central TX. A surface low will deepen across southeast OK and move east into far southern AZ. There may be enough lift due to ascent on the left exit region of mid level jet combined with isentropic lift for scattered showers to continue across the CWA. The GFS model is farther south with the upper low, moving it east across the southern TX. If the GFS were to verify then the rain chances would end Tuesday night. Mostly cloudy skies along with low-level cold air advection will keep highs in the mid to upper 50s. && .AVIATION...(For the 06Z TAFS through 06Z Friday) Issued at 1103 PM CST WED MAR 2 2016 VFR conditions are expect to persist through the night as some dry air remains in the low levels. The one potential wrench in this forecast is the NAM showing a brief period of MVFR CIGS around 12Z. The RAP and GFS are a little less obvious in the RH progs and there aren`t a lot of low clouds upstream across eastern NEB or western IA. Therefore have maintained a VFR forecast and will monitor trends. Precip timing is based on the latest HRRR/RAP/NAM consensus, which fits in fairly well with the prev forecast. Impact from the light showers at the terminals is expected to be minor with conditions remaining VFR. && .FIRE WEATHER... Issued at 313 PM CST WED MAR 2 2016 A Red Flag Warning will continue for the remainder of this afternoon for portions of eastern Kansas. Relative Humidities have dropped blow 20 percent along with 30 to 50 MPH wind gusts this afternoon. Do not burn the remainder of this afternoon! There will be a very high to extreme rangeland fire index friday afternoon across the CWA. At this time in the forecast, minimum RHs will be in the 20 to 30 percent range and southerly wind gust will be in the 30 MPH range. However, deeper mixing will likely cause dewpoints to be lower than forecasted and wind gust to be higher leading to extreme fire danger. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Sanders LONG TERM...Gargan AVIATION...Wolters FIRE WEATHER...Gargan
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1101 PM EST FRI MAR 4 2016 .UPDATE... ISSUED AT 1058 PM EST FRI MAR 4 2016 THE LOW CLOUDS HAVE BROKEN UP AS THE LOW LEVEL FLOW HAS BECOME MORE WESTERLY UNDER A WEAK AREA OF RIDGING IN BETWEEN A DEPARTING SYSTEM AND AN APPROACHING UPPER LEVEL DISTURBANCE AND COLD FRONT. MODEL TIME HEIGHT SECTIONS SUGGEST BREAKS OR EVEN CLEAR SKIES FOR THE NEXT 5 HOURS OR SO BEFORE CLOUDS SHOULD THICKEN AND LOWER IN ADVANCE OF THE COLD FRONT. THIS SHOULD LEAD TO CONTINUED FOG DEVELOPMENT AND WITH TEMPERATURES NEAR FREEZING PATCHY BLACK ICE IS A CONCERN ON BRIDGES AND OVERPASSES. ELSEWHERE NORTH OF THE MTN PARKWAY WHERE SNOW REMAINS ON THE GROUND MELTING ON FRIDAY LED TO WET ROADS IN SOME LOCATIONS. THIS COULD ALSO LEAD TO SOME PATCHY BLACK ICE. THE POTENTIAL FOR BLACK ICE HAS BEEN ADDED TO THE HWO. OTHERWISE...AS FOR THE SYSTEM ARRIVING ON SATURDAY... SCATTERED SHOWERS POSSIBLY ARRIVING AS EARLY AS 9 AM TO 10 AM EST PER THE 0Z GFS AND RECENT HRRR RUN...OR LATER PER RAP AND NAM GUIDANCE. ANY INITIAL PRECIPITATION COULD FALL AS A RAIN AND SNOW MIX BEFORE WARM ADVECTION THROUGHOUT THE COLUMN IN ADVANCE OF THE COLD FRONT TURNS ANY PRECIPITATION TO ALL RAIN BY MIDDAY. UPDATE ISSUED AT 630 PM EST FRI MAR 4 2016 WEAK UPSLOPE FLOW AND MOIST LOW LEVELS IS LEADING TO SOME DRIZZLE OR VERY LIGHT RAIN...AND OR HIGH ELEVATION FLURRIES ACROSS THE REGION. THIS SHOULD CONTINUE MAINLY ACROSS THE SOUTHEAST PART OF THE CWA UNTIL LATE EVENING BEFORE THE LOW LEVEL FLOW BECOMES MORE WESTERLY AND THE MOISTURE BECOMES MORE SHALLOW. PATCHY FOG SHOULD ALSO BE COMMONPLACE...BOTH ON THE RIDGES AND IN SOME VALLEY LOCATIONS. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 345 PM EST FRI MAR 4 2016 LATEST GOES WV IMAGERY SHOWS THE UPPER LEVEL TROUGH AXIS PUSHING OFF TO THE EAST ALLOWING FOR SOME TEMPORARY DRYING AT MID LEVELS. AT LOW LEVELS...HOWEVER...MOISTURE AND CLOUDS WILL LIKELY REMAIN IN PLACE THROUGH THE OVERNIGHT PERIOD...WITH THE POTENTIAL FOR SOME SCOURING OUT OF THE CLOUDS IN NORTHWESTERN LOCATIONS. A FEW STRAY SHOWERS ARE ALSO POSSIBLE THIS EVENING. LOWS WILL STAY IN THE LOWER 30S. GOES IR IMAGERY SHOWS MID AND HIGH LEVEL CLOUDS STARTING TO SPREAD INTO THE REGION AHEAD OF THE NEXT SHORTWAVE TROUGH. THIS TROUGH WILL DROP DOWN FROM THE NORTHERN PLAINS TONIGHT AND PASS THROUGH EASTERN KENTUCKY DURING THE DAY TOMORROW...PROVIDING CHANCES OF MAINLY RAIN SHOWERS. DUE TO THE COLDER TEMPERATURES IN THE NORTHERN COUNTIES...KEPT A BRIEF CHANCE OF A RAIN/SNOW MIX EARLY ON. RAIN SHOWERS WILL CONTINUE THROUGHOUT THE DAY AND THEN GRADUALLY PUSH OFF TO THE EAST SATURDAY NIGHT. HIGHS WILL REBOUND INTO THE UPPER 40S AND LOWER 50S NORTH...WITH SOME MID 50S NOTED IN THE SOUTHWEST. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 405 PM EST FRI MAR 4 2016 THE MODELS HAVE COME INTO BETTER AGREEMENT ALOFT THROUGH THE EXTENDED PORTION OF THE FORECAST. THEY ALL DEPICT THE DEPARTURE OF A SHORTWAVE TROUGH TO THE SOUTHEAST ON SUNDAY WITH RIDGING BUILDING INTO THE AREA THROUGH MONDAY MORNING. AROUND THIS TIME A DEEP AND BROAD TROUGH STARTS TO SET UP OVER THE WESTERN UNITED STATES. THIS TROUGH SETTLES DEEP INTO SOUTHERN CALIFORNIA AND INTO NORTHERN MEXICO WHILE SENDING SPURS OF ENERGY NORTHEAST INTO THE SOUTHERN PLAINS. WITH TIME...THE RIDGE BUILDS STRONGER OVER THE SOUTHERN APPALACHIANS WHILE THE WESTERN TROUGH CLOSES OFF OVER THE MOUNTAINS OF NORTHWESTERN MEXICO. THIS WILL SET UP BROAD SOUTHWEST FLOW INTO THE SOUTHERN PLAINS...ONLY SLOWLY MOVING EAST THROUGH THE MIDDLE OF THE WEEK. ALL THESE FEATURES TIGHTEN UP INTO WEDNESDAY WITH MORE RIDGING EAST AND TROUGHING TO THE SOUTHWEST. THROUGH THE DEEP SOUTH SOUTHWEST FLOW...FROM OVER THE WESTERN GULF...PLENTY OF ENERGY WILL RUN NORTHEAST INTO THE SOUTHERN PLAINS AND CENTRAL MISSISSIPPI VALLEY INTO THURSDAY. MEANWHILE... EAST KENTUCKY WILL BE UNDER THE HEAVY INFLUENCE OF STRONG RIDGING WHOSE CENTER WILL SLOWLY SLIP SOUTH TO SOUTHERN FLORIDA. THE CUTOFF SOUTHERN LOW WILL START TO GET PICKED UP BY THE NORTHERN STREAM LATE IN THE WEEK WITH A BETTER CHANCE OF ENERGY SPILLING INTO KENTUCKY. FOR FRIDAY...THE MODELS ARE IN GENERAL AGREEMENT WITH THE BROAD LOW MOVING TOWARD THE MISSISSIPPI DELTA WITH GENERAL SOUTHERLY FLOW CONTINUING OVER KENTUCKY. DUE TO THE DECENT MODEL AGREEMENT HAVE FAVORED A GENERAL BLEND FOR THE FORECAST DETAILS. SENSIBLE WEATHER WILL FEATURE MODERATING TEMPERATURES ON SUNDAY AS HIGH PRESSURE CROSSES THE OHIO VALLEY AND WEAK LOW PRESSURE MOVES AWAY FROM THE AREA. FOLLOWING THIS...THE HIGH MOVES TO THE EAST COAST AND AS IT DOES SO TEMPERATURES WILL REALLY SOAR REACHING WELL INTO THE MID 60S BY MONDAY AFTERNOON. THIS PATTERN WILL THEN BE RATHER STEADY STATE THROUGH THE BULK OF THE WEEK. HIGH PRESSURE WILL KEEP THE RAINS OF THE WEST AT BAY FOR MOST OF THE CWA DURING THIS TIME. THIS WILL LIKELY SPARE EAST KENTUCKY FROM THE VERY HEAVY RAINS THAT WILL BE SETTING UP FOR PARTS OF THE SOUTHERN PLAINS AND INTO THE WESTERN OHIO VALLEY. EVENTUALLY...THOUGH... THE PATTERN WILL SHIFT EAST ENOUGH THAT SHOWERS AND POSSIBLE THUNDERSTORMS WILL MOVE INTO OUR AREA FOR WEDNESDAY AND THURSDAY. ADDITIONAL SHOWERS CAN BE ANTICIPATED FOR FRIDAY...AS WELL. ALSO THROUGH IT ALL...TEMPERATURES WILL REMAIN WELL ABOVE NORMAL BOTH FOR HIGHS AND NIGHTTIME LOWS. THE ONLY CONCERN WILL BE FOR PERHAPS EXCESSIVE RAINS LATE IN THE WEEK AND BEYOND AS THIS AREA OF VERY MOIST LOW PRESSURE SLOWLY EDGES INTO THE DEEP SOUTH AND TENNESSEE VALLEY. ADJUSTED THE GRIDS FROM THE CR INIT MAINLY TO ACCOUNT FOR DECENT SMALL RIDGE TO VALLEY TEMPERATURE DIFFERENCES SUNDAY THROUGH WEDNESDAY NIGHTS. ALSO TWEAKED THE POP GRIDS FOR THE LATTER PART OF THE PERIOD TO SLOW THE ARRIVAL OF THE HIGHER POPS INTO OUR WESTERN ZONES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 650 PM EST FRI MAR 4 2016 LOW LEVEL MOISTURE REMAINS ALONG WITH WEAK UPSLOPE FLOW AND SOME FOG AS WELL AS SOME FOG AND DRIZZLE ACROSS THE SOUTHEAST PART OF THE AREA. CIGS AND OR VIS ARE GENERALLY IFR TO MVFR ACROSS THE AREA. IMPROVEMENT BACK TO MVFR AND OR VFR IS POSSIBLE OVERNIGHT... BEFORE THE NEXT SYSTEM BRINGS A THREAT OF SHOWERS AND CONTINUED MVFR OR A RETURN TO MVFR GENERALLY FROM 14Z THROUGH THE END OF THE PERIOD. WINDS SHOULD GENERALLY REMAIN AT 10 KT OR LESS THROUGH THE PERIOD...INITIALLY FROM THE WEST OR NORTHWEST BEFORE BECOMING SOUTHWEST FROM 9Z ON. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...JVM LONG TERM...GREIF AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
111 AM EST THU MAR 3 2016 .UPDATE... ISSUED AT 111 AM EST THU MAR 3 2016 THICKER CLOUDS ARE STARTING TO WORK IN FROM THE WEST. TEMPERATURES HAVE MOSTLY LIKELY BOTTOMED OUT AT THIS POINT...WITH SOME OF THE SHELTERED VALLEYS REPORTING IN THE LOWER 20S. THE CURRENT FORECAST HAS THINGS WELL IN HAND...SO WILL ONLY BE FRESHENING UP THE HOURLY TEMPERATURES...DEW POINTS...AND SKY COVER THROUGH DAWN TO ACCOUNT FOR THE LATEST TRENDS IN OBSERVATIONS. UPDATE ISSUED AT 1106 PM EST WED MAR 2 2016 HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND TRENDS. FOR NOW...WE HAVE OPTED TO LEAVE THE FORECAST FOR THURSDAY UNCHANGED FROM THE PREVIOUS UPDATE. THE 0Z GFS IS MORE CONSISTENT WITH THICKNESSES AND COLUMN TEMPERATURES WHICH WOULD POINT TOWARD A MIX OF RAIN AND SNOW AT ONSET TO RAIN ON THURSDAY. IT STILL DOES APPEAR THAT ALL LOCATIONS SHOULD MEASURE ON THURSDAY. THE 0Z NAM HAS SOME MORE INTENSE PRECIPITATION ON THURSDAY AFTERNOON AND COOLS THE COLUMN TO NEAR FREEZING WHICH WOULD POINT TOWARD SOME POTENTIAL FOR ACCUMULATING SNOW. UPDATE ISSUED AT 658 PM EST WED MAR 2 2016 HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT OBSERVATIONS AND TRENDS. IT WILL BE A WHILE BEFORE THICKER CLOUDS MOVE INTO THE AREA AND THIS SHOULD SET THE STAGE FOR VALLEY LOCATIONS IN PARTICULAR TO DROP WELL INTO THE 20S WITH A NOCTURNAL INVERSION SETTING UP. LOWS FOR DEEPER VALLEYS HAVE BEEN LOWERED ACCORDINGLY. OTHERWISE...MAX TEMPERATURES FOR TOMORROW SEEMED A BIT TOO HIGH AND HAVE BEEN LOWERED A BIT CLOSER TO MODEL BLEND NUMBERS. THIS LED TO A BIT SLOWER ANTICIPATED SFC TEMPERATURE RISE WHEN PRECIPITATION LIKELY AS SNOW OR A RAIN SNOW MIX SHOULD MOVE INTO THE AREA FOR THURSDAY...WHICH MIGHT ALLOW FOR A DUSTING TO LESS THAN A HALF OF ACCUMULATION ON GRASSY AND ELEVATED SURFACES IN SOME AREAS PARTICULARLY RIDGETOPS. HOWEVER...NO TRAVEL IMPACTS ARE ANTICIPATED. MOST IF NOT ALL LOCATIONS SHOULD HAVE MEASURABLE PRECIPITATION ON THURSDAY...SO POPS HAVE BEEN INCREASED TO CATEGORICAL IN ALL LOCATIONS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 300 PM EST WED MAR 2 2016 HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE AREA THROUGH THIS EVENING BUT THEN QUICKLY SHIFT OFF TO THE EAST OVERNIGHT. CLOUDS WILL BE ON THE INCREASE OVERNIGHT AHEAD OF A CLIPPER LOW PRESSURE SYSTEM THAT IS PROGGED TO PASS THROUGH THE VICINITY OR JUST SOUTH OF THE AREA TOMORROW MORNING AND AFTERNOON. PRECIPITATION WILL LIKELY START OUT AS LIGHT SNOW OR A MIX OF RAIN AND SNOW DURING THE MORNING BEFORE TRANSITIONING TO A COLD RAIN FOR THE MAJORITY OF THE EVENT. LITTLE TO NO SNOW ACCUMULATION IS EXPECTED. ALSO DO NOT EXPECT ANY TRAVEL IMPACTS BECAUSE THE ROAD TEMPERATURES ACROSS THE AREA ARE CURRENTLY IN THE MID TO UPPER 40S AND ARE NOT EXPECTED TO DROP TO THE FREEZING MARK. AS THE LOW EXITS THE REGION LATE THURSDAY NIGHT...RAIN MAY TRANSITION BACK TO A MIX OF RAIN/SNOW AS THE PRECIPITATION TAPERS OFF. TEMPERATURES WILL REMAIN ON THE COLD SIDE THROUGH THE SHORT TERM PERIOD WITH TEMPS TONIGHT DROPPING OFF INTO THE MID AND UPPER 20S. HIGH TEMPERATURES ON THURSDAY WILL ONLY REACH THE UPPER 30S/LOWER 40S AND LOWS THAT NIGHT DIPPING BACK INTO THE 30S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 446 PM EST WED MAR 2 2016 A RAPIDLY DEEPENING LOW IS EXPECTED TO BE LOCATED NEAR CAPE HATTERAS AT THE START OF THE PERIOD...WITH THE JKL FORECAST AREA ON THE WESTERN FRINGE OF ITS INFLUENCE. A BIT OF LINGERING SNOW OR RAIN IS POSSIBLE IN THE SOUTHEAST PART OF THE AREA FRIDAY MORNING BEFORE HIGH PRESSURE BUILDS IN FROM THE NORTHWEST DURING THE DAY. ITS PRESENCE WILL BE FLEETING...AS IT DEPARTS TO THE SOUTHEAST AND A WEAK LOW PRESSURE SYSTEM MOVES EAST SOUTHEAST ACROSS THE CENTRAL APPALACHIANS SATURDAY NIGHT. MODELS HAVE TRENDED DRIER IN THE JKL FORECAST AREA FOR THIS SYSTEM...WITH MOST OF THE PRECIP TO OUR NORTH AND NORTHEAST. HAVE TRIMMED POPS TO ONLY INCLUDE A SLIGHT CHANCE OF PRECIP IN OUR NORTHERN AND EASTERN COUNTIES. ANOTHER AREA OF HIGH PRESSURE BUILDING IN FROM THE NORTHWEST WILL BRING DECREASING CLOUDS SUNDAY...AND PARK ITSELF OFF THE EAST COAST EARLY IN THE WEEK. THIS WILL OCCUR AS A HIGHLY AMPLIFIED PATTERN SETS UP...WITH AN UPPER LOW SLOWLY MOVING EAST SOUTHEAST ALONG THE MEXICAN BORDER NEXT WEEK...WHILE STRONG RIDGING DEVELOPS ALONG THE SOUTHEAST COAST. THE SLOWLY MOVING REGIME WILL BRING WARM AIR ADVECTION FOR OUR AREA. HOWEVER...WE WILL NOT HAVE A GOOD TRAJECTORY OFF THE GULF AND SHOULD SEE OUR LOW LEVEL MOISTURE INCREASE MORE SLOWLY WHEN COMPARED TO AREAS FURTHER WEST. THIS WOULD HELP TO LIMIT OUR PRECIP POTENTIAL UNTIL WEDNESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 111 AM EST THU MAR 3 2016 CLOUDS WILL THICKEN AND LOWER OVERNIGHT OUT AHEAD OF AN AREA OF SURFACE LOW PRESSURE THAT PASS BY TO OUR SOUTH DURING THE DAY. THIS WILL SPREAD A MIX OF LIGHT RAIN/SNOW ACROSS THE AREA BETWEEN 15 AND 18Z...BEFORE TRANSITIONING TO LIGHT RAIN. CEILINGS/VISIBILITIES WILL LOWER TO MVFR...WITH IFR CEILINGS EXPECTED BY THIS EVENING. WINDS WILL REMAIN OUT OF THE EAST AND SOUTHEAST AT AROUND 5 KTS THROUGH THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...JVM LONG TERM...HAL AVIATION...GEOGERIAN
Area Forecast Discussion National Weather Service Louisville KY 1249 AM EST THU MAR 3 2016 ...Updated Aviation Discussion... ...Forecast Update... Updated 930 PM EST Wed Mar 3 2016 Temps are close to forecast lows, especially across the Bluegrass region. Mid-level clouds continue to spread east from the mid Mississippi Valley as the upper wave digs in, and will put the brakes on any continued drop in temps. Have included a non-diurnal temp curve overnight to reflect this. Low confidence in precip type at onset Thursday morning. With so much dry air to overcome, we have a sounding that could produce snow, but it doesn`t seem like we have the forcing to squeeze out a lot of precip quickly enough. Will not make substantial changes to precip types until the midnight crew has a look at the 00Z guidance. What is apparent is that if we end up with widespread precip to go along with easterly winds, temps will have a really hard time recovering during the day. Have trended Thu max temps down by a few degrees, with lower to mid 40s in most locations. Will have a hard time cracking 40 in the northern Bluegrass. .SHORT TERM (Now through Thursday Night)... Issued at 300 PM EST Wed Mar 2 2016 Finally getting some clearing as one system heads off to the east. In its wake however is another system starting to bring in high clouds. Low pressure associated with this system will move into northern MO by daybreak Thursday. Weak isentropic lift over our area will make for light radar returns by then. Dry low-level air should weaken/dry out the precip somewhat, but as the day goes along that dry air should moisten up...especially as the better lift comes ahead of trough swinging through by late afternoon. By the time the column moistens, we should just see all rain, but cannot rule out a few flurries early on in the day. Rainfall totals look to range from a tenth to two tenths of an inch. After tonight`s lows around freezing, temperatures during the day should mostly stay in the 40s, though a few 50s are possible across south central KY. Will keep in some light precip on the back side of the system Thursday night and associated cloud cover will keep temperatures in the low to mid 30s. This precip may see a transition overnight from rain to snow as temperatures fall, especially over the north, but still not looking at any significant accumulations. .LONG TERM (Friday through Wednesday)... Issued at 320 PM EST Wed Mar 2 2016 Friday we may start off with continued light precip over the Bluegrass, but will keep pops silent as measurable snow looks unlikely. Cloud cover should hold on for most of the day, so have temperatures only in the low to mid 40s. High pressure will move over the region Friday evening before shift east toward daybreak Saturday. Yet another trough will breeze through the region Saturday, bringing another batch of light precip across the north. Southwesterly winds ahead of this system will mean highs rising into the 50s. High pressure will build in quickly behind this front, allowing temperatures to fall into the 30s at night, close to normal like the highs Saturday. Sunday and Monday we should see another warmup, with increasing southerly winds. Highs by Monday should be well into the 60s. We may see some warm air advection showers Monday night west of I-65. Then for Tuesday, the trend in the models has been for our storm chances to remain west of I-65. That trend would keep us in the warm sector and allow for high temperatures closer to 70. Then Tuesday night and Wednesday both deterministic and ensemble solutions drift a front into the region, perhaps stalling it. Thus will go with higher pops and above normal temperatures with the muggy airmass. The type of setup shown by the 12Z GFS and Euro are indicative of those that bring flood conditions, so will have to watch how the models trend over the next few days. && .AVIATION (06Z TAF Update)... Updated at 1245 AM EST Thu Mar 3 2016 The latest 0Z guidance has trended colder and a bit snowier with the northern stream low pressure system passing through the Ohio Valley today. VFR conditions can be expected until precip associated with this weather system arrives. All TAF sites look to begin as a cold rain between 15-17Z with flight conditions quickly dropping to MVFR. BWG should stay all rain for the remainder of the day and then drizzle as precip ends tonight. SDF/LEX will be a bit colder and precip may change over to snow especially in heavier bursts during the afternoon hours and as temps cool during the evening hrs so have added periods of -RASN to these TAFs. IFR conditions should begin at all TAF sites by this afternoon and persist through the end of the TAF period. VRB winds early this morning will become predominantly ESE for much of the TAF period with wind speeds of 6-9 kts common this afternoon. && .LMK Watches/Warnings/Advisories... KY...NONE. IN...NONE. && $$ Update.........RAS Short Term.....RJS Long Term......RJS Aviation.......AMS
Area Forecast Discussion National Weather Service Louisville KY 1249 AM EST THU MAR 3 2016 ...Updated Aviation Discussion... ...Forecast Update... Updated 930 PM EST Wed Mar 3 2016 Temps are close to forecast lows, especially across the Bluegrass region. Mid-level clouds continue to spread east from the mid Mississippi Valley as the upper wave digs in, and will put the brakes on any continued drop in temps. Have included a non-diurnal temp curve overnight to reflect this. Low confidence in precip type at onset Thursday morning. With so much dry air to overcome, we have a sounding that could produce snow, but it doesn`t seem like we have the forcing to squeeze out a lot of precip quickly enough. Will not make substantial changes to precip types until the midnight crew has a look at the 00Z guidance. What is apparent is that if we end up with widespread precip to go along with easterly winds, temps will have a really hard time recovering during the day. Have trended Thu max temps down by a few degrees, with lower to mid 40s in most locations. Will have a hard time cracking 40 in the northern Bluegrass. .SHORT TERM (Now through Thursday Night)... Issued at 300 PM EST Wed Mar 2 2016 Finally getting some clearing as one system heads off to the east. In its wake however is another system starting to bring in high clouds. Low pressure associated with this system will move into northern MO by daybreak Thursday. Weak isentropic lift over our area will make for light radar returns by then. Dry low-level air should weaken/dry out the precip somewhat, but as the day goes along that dry air should moisten up...especially as the better lift comes ahead of trough swinging through by late afternoon. By the time the column moistens, we should just see all rain, but cannot rule out a few flurries early on in the day. Rainfall totals look to range from a tenth to two tenths of an inch. After tonight`s lows around freezing, temperatures during the day should mostly stay in the 40s, though a few 50s are possible across south central KY. Will keep in some light precip on the back side of the system Thursday night and associated cloud cover will keep temperatures in the low to mid 30s. This precip may see a transition overnight from rain to snow as temperatures fall, especially over the north, but still not looking at any significant accumulations. .LONG TERM (Friday through Wednesday)... Issued at 320 PM EST Wed Mar 2 2016 Friday we may start off with continued light precip over the Bluegrass, but will keep pops silent as measurable snow looks unlikely. Cloud cover should hold on for most of the day, so have temperatures only in the low to mid 40s. High pressure will move over the region Friday evening before shift east toward daybreak Saturday. Yet another trough will breeze through the region Saturday, bringing another batch of light precip across the north. Southwesterly winds ahead of this system will mean highs rising into the 50s. High pressure will build in quickly behind this front, allowing temperatures to fall into the 30s at night, close to normal like the highs Saturday. Sunday and Monday we should see another warmup, with increasing southerly winds. Highs by Monday should be well into the 60s. We may see some warm air advection showers Monday night west of I-65. Then for Tuesday, the trend in the models has been for our storm chances to remain west of I-65. That trend would keep us in the warm sector and allow for high temperatures closer to 70. Then Tuesday night and Wednesday both deterministic and ensemble solutions drift a front into the region, perhaps stalling it. Thus will go with higher pops and above normal temperatures with the muggy airmass. The type of setup shown by the 12Z GFS and Euro are indicative of those that bring flood conditions, so will have to watch how the models trend over the next few days. && .AVIATION (06Z TAF Update)... Updated at 1245 AM EST Thu Mar 3 2016 The latest 0Z guidance has trended colder and a bit snowier with the northern stream low pressure system passing through the Ohio Valley today. VFR conditions can be expected until precip associated with this weather system arrives. All TAF sites look to begin as a cold rain between 15-17Z with flight conditions quickly dropping to MVFR. BWG should stay all rain for the remainder of the day and then drizzle as precip ends tonight. SDF/LEX will be a bit colder and precip may change over to snow especially in heavier bursts during the afternoon hours and as temps cool during the evening hrs so have added periods of -RASN to these TAFs. IFR conditions should begin at all TAF sites by this afternoon and persist through the end of the TAF period. VRB winds early this morning will become predominantly ESE for much of the TAF period with wind speeds of 6-9 kts common this afternoon. && .LMK Watches/Warnings/Advisories... KY...NONE. IN...NONE. && $$ Update.........RAS Short Term.....RJS Long Term......RJS Aviation.......AMS
Area Forecast Discussion National Weather Service Louisville KY 1249 AM EST THU MAR 3 2016 ...Updated Aviation Discussion... ...Forecast Update... Updated 930 PM EST Wed Mar 3 2016 Temps are close to forecast lows, especially across the Bluegrass region. Mid-level clouds continue to spread east from the mid Mississippi Valley as the upper wave digs in, and will put the brakes on any continued drop in temps. Have included a non-diurnal temp curve overnight to reflect this. Low confidence in precip type at onset Thursday morning. With so much dry air to overcome, we have a sounding that could produce snow, but it doesn`t seem like we have the forcing to squeeze out a lot of precip quickly enough. Will not make substantial changes to precip types until the midnight crew has a look at the 00Z guidance. What is apparent is that if we end up with widespread precip to go along with easterly winds, temps will have a really hard time recovering during the day. Have trended Thu max temps down by a few degrees, with lower to mid 40s in most locations. Will have a hard time cracking 40 in the northern Bluegrass. .SHORT TERM (Now through Thursday Night)... Issued at 300 PM EST Wed Mar 2 2016 Finally getting some clearing as one system heads off to the east. In its wake however is another system starting to bring in high clouds. Low pressure associated with this system will move into northern MO by daybreak Thursday. Weak isentropic lift over our area will make for light radar returns by then. Dry low-level air should weaken/dry out the precip somewhat, but as the day goes along that dry air should moisten up...especially as the better lift comes ahead of trough swinging through by late afternoon. By the time the column moistens, we should just see all rain, but cannot rule out a few flurries early on in the day. Rainfall totals look to range from a tenth to two tenths of an inch. After tonight`s lows around freezing, temperatures during the day should mostly stay in the 40s, though a few 50s are possible across south central KY. Will keep in some light precip on the back side of the system Thursday night and associated cloud cover will keep temperatures in the low to mid 30s. This precip may see a transition overnight from rain to snow as temperatures fall, especially over the north, but still not looking at any significant accumulations. .LONG TERM (Friday through Wednesday)... Issued at 320 PM EST Wed Mar 2 2016 Friday we may start off with continued light precip over the Bluegrass, but will keep pops silent as measurable snow looks unlikely. Cloud cover should hold on for most of the day, so have temperatures only in the low to mid 40s. High pressure will move over the region Friday evening before shift east toward daybreak Saturday. Yet another trough will breeze through the region Saturday, bringing another batch of light precip across the north. Southwesterly winds ahead of this system will mean highs rising into the 50s. High pressure will build in quickly behind this front, allowing temperatures to fall into the 30s at night, close to normal like the highs Saturday. Sunday and Monday we should see another warmup, with increasing southerly winds. Highs by Monday should be well into the 60s. We may see some warm air advection showers Monday night west of I-65. Then for Tuesday, the trend in the models has been for our storm chances to remain west of I-65. That trend would keep us in the warm sector and allow for high temperatures closer to 70. Then Tuesday night and Wednesday both deterministic and ensemble solutions drift a front into the region, perhaps stalling it. Thus will go with higher pops and above normal temperatures with the muggy airmass. The type of setup shown by the 12Z GFS and Euro are indicative of those that bring flood conditions, so will have to watch how the models trend over the next few days. && .AVIATION (06Z TAF Update)... Updated at 1245 AM EST Thu Mar 3 2016 The latest 0Z guidance has trended colder and a bit snowier with the northern stream low pressure system passing through the Ohio Valley today. VFR conditions can be expected until precip associated with this weather system arrives. All TAF sites look to begin as a cold rain between 15-17Z with flight conditions quickly dropping to MVFR. BWG should stay all rain for the remainder of the day and then drizzle as precip ends tonight. SDF/LEX will be a bit colder and precip may change over to snow especially in heavier bursts during the afternoon hours and as temps cool during the evening hrs so have added periods of -RASN to these TAFs. IFR conditions should begin at all TAF sites by this afternoon and persist through the end of the TAF period. VRB winds early this morning will become predominantly ESE for much of the TAF period with wind speeds of 6-9 kts common this afternoon. && .LMK Watches/Warnings/Advisories... KY...NONE. IN...NONE. && $$ Update.........RAS Short Term.....RJS Long Term......RJS Aviation.......AMS
Area Forecast Discussion National Weather Service Paducah KY 1106 PM CST WED MAR 2 2016 .UPDATE... Issued at 1106 PM CST WED MAR 2 2016 Updated aviation section for 06z taf issuance UPDATE issued at 934 PM CST WED MAR 2 2016 Starting to see some decent signal for a drier forecast overnight and Thursday over the north/northeast portions of the area. The 00Z NAM keeps the entire area dry through 12Z, and then spreads precipitation eastward through southeast Missouri and much of west Kentucky. The latest RAP and HRRR runs also have trended this way. Decided to trend drier over the Evansville Tri State and the Pennyrile region of west Kentucky through 12Z, and then blend with the likely to categorical PoPs throughout the area later in the day. Also trended warmer with overnight temperatures in the east, with most places not likely to drop much from current levels, unless there is enough precipitation to wet bulb which is unlikely. && .SHORT TERM...(This evening through Friday night) Issued at 258 PM CST WED MAR 2 2016 Clouds are starting to increase now, and will be working down from the mid levels overnight as showers set in tmrw. Instability parameters keep thunder chances just outside (mainly south) of PAH FA thru the event, but with the surface/upper Low tracks across the FA, wouldnt be shocked to see an isolated stroke. No consensus for adding though, so went just showers for the event. The system is positively tilted, filling, and weakening as it moves across the FA. Good moisture influx and deep column moisture advection means main impact will be qpf, with low end totals of 1/4 to 1/2" expected, and high end amounts approaching 1" not out of the realm of possibility. While a lingering sprinkle or two is not of the question, the wetting rain event is over tmrw. Moisture does take awhile to scour, so clouds could be stubborn/hang into Friday, particularly east, before clearing out in earnest. .LONG TERM...(Saturday through Wednesday) Issued at 258 PM CST WED MAR 2 2016 The more significant weather during the extended period will be focused toward the last day of the seven day forecast period (Tuesday). Through at least Sunday, the WFO PAH forecast area is expected to gradually shift from northwest flow ahead of slowly moving westward tilted upper level high pressure ridge to southerly flow as this ridge axis moves over the area during the day on Sunday. The net effect for the weekend will be dry weather and warmer temperatures. From Sunday night onward, both ensemble and deterministic guidance carve out a convoluted mean trough over the western 1/2 of the U.S. with successive shortwaves deepening the trough. There is a wide variability in the exact location/orientation of the trough via the 12z Wednesday deterministic GFS/ECMWF, but both seem to show an initial progressive trough over the northern Mexico and the desert Southwest U.S., before becoming meridional by early Wednesday. Given the open and strong fetch of Gulf of Mexico moisture and the persistent nature of the baroclinic gradient on the east side of this trough, anticipate isentropically lifted shower activity will dominate parts of Southeast Missouri and Southern Illinois, as early as Sunday night and persisting through Monday night. Initially, it looks like Tuesday into Wednesday of next week (just beyond the seven day forecast period) will be interesting. Model Analogs from the GFS Ensemble suggest that there will be around a 50% probability of close to one half inch of rain with a 30% probability in excess of one inch, mainly over Southeast Missouri and part of Southwest Illinois. NCEP modeling center QPF plumes suggest an average 2" precipitation between 12z Tuesday to 12z Wednesday of next week centered near Paducah. An Atmospheric River forecast forecast prog (presented by our SOO), suggests that deep moisture will be working up the Mississippi River next week. The only caveat to a heavy rain setup for part of the WFO PAH forecast area will be intervening convective development that could occur over the Lower Mississippi Valley, impacting parts of Mississippi, Alabama, and Tennessee. Regardless, it will be worth watching and planning for heavy rain potential and possible severe weather early next week, beginning with the Monday/Tuesday time frame. SPC is already monitoring the potential for severe weather for early next week. && .AVIATION... Issued at 1106 PM CST WED MAR 2 2016 Widespread mid clouds around 10k feet will continue through the night, possibly producing some virga. Unusually dry southeast winds will evaporate the precip before it reaches the ground. Between 12z and 18z Thursday, the low levels will moisten up as heavier precipitation starts falling through the column. Cigs and vsbys will lower to mvfr. A period of ifr conditions is likely for at least a few hours where the heavier precip occurs. The 06z tafs will forecast ifr at kcgi/kpah based on heavier precip rates in those areas. && .PAH Watches/Warnings/Advisories... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...DRS AVIATION...MY
AREA FORECAST DISCUSSION
NWS GRAY ME
934 PM EST FRI MAR 4 2016 .SYNOPSIS... LOW PRESSURE WILL PASS WELL OFF THE COAST TONIGHT. HIGH PRESSURE WILL START TO BUILD OVER THE REGION THROUGHOUT THE WEEKEND AND INTO NEXT WEEK. AS HIGH PRESSURE DOMINATES OVER MUCH OF THE EAST COAST NEXT WEEK...SOUTHWESTERLY FLOW WILL SET UP OVER NEW ENGLAND. THIS WILL ALLOW MUCH WARMER AIR TO STREAM INTO THE AREA. BY MIDWEEK TEMPERATURES ARE EXPECTED TO BE WELL ABOVE NORMAL. A WEAK COLD FRONT WILL TRY TO CROSS THE AREA ON THURSDAY. && .NEAR TERM /THROUGH SATURDAY/... UPDATE... HAVE UPDATED THE GRIDS BASED ON CURRENT OBSERVATIONS...RADAR TRENDS AND MESOSCALE MODEL DATA. LIGHT SNOW SHOWERS CONTINUE TO FALL OVER SOUTHWEST MAINE AND SOUTHEAST NEW HAMPSHIRE...HOWEVER MANY OF THE RETURNS DEPICTED ON RADAR ARE NOT REACHING THE GROUND AS MOISTURE IS LACKING IN THE LOWEST LEVELS. WILL TAKE DOWN THE WINTER WEATHER ADVISORIES A FEW HOURS EARLY AS LITTLE PRECIPITATION IS ACCUMULATING IN ROCKINGHAM COUNTY. HAVE ADJUSTED POPS...TEMPERATURES AND CLOUD GRIDS AS WELL. PREV DISC... BIGGEST FORECAST PROBLEM IS GOING TO BE THE OCEAN EFFECT SNOW THAT IS CONTINUING OVER SOUTHERN NEW HAMPSHIRE. WHILE THERE IS SOME LIGHT SNOW FALLING OVER PORTIONS OF COASTAL MAINE AS WELL...ROCKINGHAM COUNTY IN NEW HAMPSHIRE IS SEEING THE LIONS SHARE OF THE PRECIPITATION. BOTH THE RAP AND THE NAM12 HAVE STARTED TO PICK UP ON THIS FEATURE AND THE HRRR IS STARTING TO FALL IN LINE ALSO. IT LOOKS AS THOUGH THE SNOW COULD CONTINUE THROUGH THE AFTERNOON COMMUTE AND INTO THE EVENING HOURS. BECAUSE OF THIS...WE HAVE PULLED THE TRIGGER ON A WINTER WEATHER ADVISORY FOR ROCKINGHAM COUNTY. && .SHORT TERM /SATURDAY NIGHT/... AS THE COASTAL LOW PASSES WELL OFF TO THE EAST OF THE REGION EXPECT COOL HIGH PRESSURE TO BUILD OVER THE AREA WITH NORTHERLY FLOW. SKIES SHOULD CLEAR OUT QUICKLY ON SATURDAY WITH PLENTY OF SUNSHINE AS HIGHS CLIMB INTO THE UPPER 30S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGH IMPACT WX: NONE ANTICIPATED. LARGE SCALE HEMISPHERIC FLOW AT 500 MB AS POLAR VORTEX OVER NRN CANADA BEGINS TO SEND PIECES OFF TO THE EAST AND EVENTUALLY BREAKS DOWN THE BLOCKING OVER THE NRN ATLANTIC...WHILE A SERIES OF LOWS DEEPEN OVER THE ERN PACIFIC AND BREAK DOWN THE RIDGING OVER THE WEST COAST. THIS WILL ALLOW FOR A TREND TOWARD RIDGING OVER THE ERN 2/3 OF THE CONUS AND THE WRN AND GENERALLY DRIER CONDS /NO MAJOR STORMS/ AND SIGNIFICANTLY WARMER CONDS AS WELL. FROM A SENSIBLE WX PERSPECTIVE...SUNDAY STARTS WITH A WEAK 500 MB TROUGH MOVING THROUGH WHICH WILL PRODUCE A FAIR AMT OF MID-HIGH CLOUDS...BUT NOT MUCH ELSE. THE RIDGE STARTS BUILDING IN SUN NIGHT...BUT ANOTHER WEAK WAVE DROPS OUT OF THE POLAR VORTEX AND CLIPS THE NE ZONES MONDAY AND COULD SET OFF A FEW SHSN OR RA IN THE MTNS MONDAY. RIDGING ALOFT THE MOVES IN FOR TUE-WED WITH SFC RIDGE BUILDING TO OUR S. EURO AND GFS DOW PASS A 500MB OVER OR JUST TO OUR N LATE WED INTO THU NIGHT. MODELS DIVERGE QUITE A BIT AT THIS POINT, WITH THE GFS PUSHING MOISTURE OVER THE TOP OF THE RIDGE AROUND THU...AS A COLD FRONT STALLS OVER NEW ENGLAND. THE EURO TIMING IS REVERSED WITH THE COLD FRONT BEING PUSHED DOWN THU AND AND STALLING S OF THE CWA...AS A WAVE MOVES ALONG IT THU NIGHT. EITHER WAY...QPF NOT IMPRESSIVE ATTM...AND WILL LIKELY FALL AS RAIN. THE MODEL BLEND OF POPS GENERALLY KEEP THEM IN THE SLT CHC TO LOW CHC RANGE IN THE WED-THU NIGHT PERIOD. TEMPS START AROUND NORMAL ON SUNDAY...AROUND 30 IN THE N TO AROUND 40 IN THE S. MON WILL SEE TEMPS JUMP UP SIGNIFICANTLY WITH HIGHS FROM 40 TO 50...AND THE WILL INCREASE SEVERAL DEGREES EACH ON TUE AND WED WITH WED HIGHS WELL ABOVE NORMAL...RANGING FROM THE LOW TO MID 50S IN THE N TO 60-65 IN THE S. THE PRESENCE OF THE FRONTAL BOUNDARY AND LOTS OF CLOUDS WILL SCALE BACK TEMPS ON THU AND FRI...BUT THEY WILL STILL REMAIN ABOUT 10F ABV NORMAL. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH SAT NIGHT/...EXPECT IFR/MVFR CONDITIONS IN SNOW AT KCON...KPWM...KPSM AND KMHT. OCEAN EFFECT SNOW IS EXPECTED TO CONTINUE INTO THE EVENING HOURS. ONCE SNOW ENDS EXPECT ALL LOCATIONS TO GO VFR THROUGH SATURDAY NIGHT. LONG TERM...MAINLY VFR SUN-WED. && .MARINE... SHORT TERM /THROUGH SAT NIGHT/...AS LOW PRESSURE PASSES TO THE EAST OF THE REGION EXPECT WINDS TO PICK UP OVER THE WATERS. IT SHOULD BE A FAIRLY SHORT LIVED EVENT WITH WINDS TONIGHT AND TOMORROW. ONCE THE LOW MOVES AWAY FROM THE REGION...HIGH PRESSURE BUILDS AS WINDS DECREASE. LONG TERM...SCA POSSIBLE ON MONDAY AS WINDS SW WINDS SURGE AHEAD OF A FRONT. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ151-153. GALE WARNING UNTIL NOON EST SATURDAY FOR ANZ150-152-154. && $$
AREA FORECAST DISCUSSION
NWS GRAY ME
648 PM EST FRI MAR 4 2016 .SYNOPSIS... LOW PRESSURE WILL PASS WELL OFF THE COAST TONIGHT. HIGH PRESSURE WILL START TO BUILD OVER THE REGION THROUGHOUT THE WEEKEND AND INTO NEXT WEEK. AS HIGH PRESSURE DOMINATES OVER MUCH OF THE EAST COAST NEXT WEEK...SOUTHWESTERLY FLOW WILL SET UP OVER NEW ENGLAND. THIS WILL ALLOW MUCH WARMER AIR TO STREAM INTO THE AREA. BY MIDWEEK TEMPERATURES ARE EXPECTED TO BE WELL ABOVE NORMAL. A WEAK COLD FRONT WILL TRY TO CROSS THE AREA ON THURSDAY. && .NEAR TERM /THROUGH SATURDAY/... UPDATE... HAVE UPDATED THE GRIDS BASED ON CURRENT OBSERVATIONS...RADAR TRENDS AND MESOSCALE MODEL DATA. LIGHT SNOWS CONTINUE...MAINLY ALONG AND NEAR THE COASTLINE. UP TO 3 INCHES OF OCEAN ENHANCED SNOW FELL IN ROCKINGHAM COUNTY TODAY. SNOW IN THIS AREA HAS BEEN INTERMITTENT...HOWEVER WILL LEAVE UP WINTER WEATHER ADVISORY FOR A FEW MORE HOURS UNTIL THE BANDS SHIFT OUT TO SEA. HAVE ADJUSTED POPS...TEMPERATURES AND CLOUD GRIDS AS WELL. PREV DISC... BIGGEST FORECAST PROBLEM IS GOING TO BE THE OCEAN EFFECT SNOW THAT IS CONTINUING OVER SOUTHERN NEW HAMPSHIRE. WHILE THERE IS SOME LIGHT SNOW FALLING OVER PORTIONS OF COASTAL MAINE AS WELL...ROCKINGHAM COUNTY IN NEW HAMPSHIRE IS SEEING THE LIONS SHARE OF THE PRECIPITATION. BOTH THE RAP AND THE NAM12 HAVE STARTED TO PICK UP ON THIS FEATURE AND THE HRRR IS STARTING TO FALL IN LINE ALSO. IT LOOKS AS THOUGH THE SNOW COULD CONTINUE THROUGH THE AFTERNOON COMMUTE AND INTO THE EVENING HOURS. BECAUSE OF THIS...WE HAVE PULLED THE TRIGGER ON A WINTER WEATHER ADVISORY FOR ROCKINGHAM COUNTY. && .SHORT TERM /SATURDAY NIGHT/... AS THE COASTAL LOW PASSES WELL OFF TO THE EAST OF THE REGION EXPECT COOL HIGH PRESSURE TO BUILD OVER THE AREA WITH NORTHERLY FLOW. SKIES SHOULD CLEAR OUT QUICKLY ON SATURDAY WITH PLENTY OF SUNSHINE AS HIGHS CLIMB INTO THE UPPER 30S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGH IMPACT WX: NONE ANTICIPATED. LARGE SCALE HEMISPHERIC FLOW AT 500 MB AS POLAR VORTEX OVER NRN CANADA BEGINS TO SEND PIECES OFF TO THE EAST AND EVENTUALLY BREAKS DOWN THE BLOCKING OVER THE NRN ATLANTIC...WHILE A SERIES OF LOWS DEEPEN OVER THE ERN PACIFIC AND BREAK DOWN THE RIDGING OVER THE WEST COAST. THIS WILL ALLOW FOR A TREND TOWARD RIDGING OVER THE ERN 2/3 OF THE CONUS AND THE WRN AND GENERALLY DRIER CONDS /NO MAJOR STORMS/ AND SIGNIFICANTLY WARMER CONDS AS WELL. FROM A SENSIBLE WX PERSPECTIVE...SUNDAY STARTS WITH A WEAK 500 MB TROUGH MOVING THROUGH WHICH WILL PRODUCE A FAIR AMT OF MID-HIGH CLOUDS...BUT NOT MUCH ELSE. THE RIDGE STARTS BUILDING IN SUN NIGHT...BUT ANOTHER WEAK WAVE DROPS OUT OF THE POLAR VORTEX AND CLIPS THE NE ZONES MONDAY AND COULD SET OFF A FEW SHSN OR RA IN THE MTNS MONDAY. RIDGING ALOFT THE MOVES IN FOR TUE-WED WITH SFC RIDGE BUILDING TO OUR S. EURO AND GFS DOW PASS A 500MB OVER OR JUST TO OUR N LATE WED INTO THU NIGHT. MODELS DIVERGE QUITE A BIT AT THIS POINT, WITH THE GFS PUSHING MOISTURE OVER THE TOP OF THE RIDGE AROUND THU...AS A COLD FRONT STALLS OVER NEW ENGLAND. THE EURO TIMING IS REVERSED WITH THE COLD FRONT BEING PUSHED DOWN THU AND AND STALLING S OF THE CWA...AS A WAVE MOVES ALONG IT THU NIGHT. EITHER WAY...QPF NOT IMPRESSIVE ATTM...AND WILL LIKELY FALL AS RAIN. THE MODEL BLEND OF POPS GENERALLY KEEP THEM IN THE SLT CHC TO LOW CHC RANGE IN THE WED-THU NIGHT PERIOD. TEMPS START AROUND NORMAL ON SUNDAY...AROUND 30 IN THE N TO AROUND 40 IN THE S. MON WILL SEE TEMPS JUMP UP SIGNIFICANTLY WITH HIGHS FROM 40 TO 50...AND THE WILL INCREASE SEVERAL DEGREES EACH ON TUE AND WED WITH WED HIGHS WELL ABOVE NORMAL...RANGING FROM THE LOW TO MID 50S IN THE N TO 60-65 IN THE S. THE PRESENCE OF THE FRONTAL BOUNDARY AND LOTS OF CLOUDS WILL SCALE BACK TEMPS ON THU AND FRI...BUT THEY WILL STILL REMAIN ABOUT 10F ABV NORMAL. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH SAT NIGHT/...EXPECT IFR/MVFR CONDITIONS IN SNOW AT KCON...KPWM...KPSM AND KMHT. OCEAN EFFECT SNOW IS EXPECTED TO CONTINUE INTO THE EVENING HOURS. ONCE SNOW ENDS EXPECT ALL LOCATIONS TO GO VFR THROUGH SATURDAY NIGHT. LONG TERM...MAINLY VFR SUN-WED. && .MARINE... SHORT TERM /THROUGH SAT NIGHT/...AS LOW PRESSURE PASSES TO THE EAST OF THE REGION EXPECT WINDS TO PICK UP OVER THE WATERS. IT SHOULD BE A FAIRLY SHORT LIVED EVENT WITH WINDS TONIGHT AND TOMORROW. ONCE THE LOW MOVES AWAY FROM THE REGION...HIGH PRESSURE BUILDS AS WINDS DECREASE. LONG TERM...SCA POSSIBLE ON MONDAY AS WINDS SW WINDS SURGE AHEAD OF A FRONT. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NHZ013- 014. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ151-153. GALE WARNING UNTIL NOON EST SATURDAY FOR ANZ150-152-154. && $$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1201 PM EST THU MAR 3 2016 .AVIATION... SURFACE HIGH PRESSURE AND LOW LEVEL DRY AIR OVER MUCH OF LOWER MICHIGAN HAS BEEN STUBBORN THUS FAR...BUT STILL EXPECT SNOW TO OVERSPREAD SOUTHEAST MICHIGAN SOUTH OF I-69 CORRIDOR THIS AFTERNOON...CONTINUING INTO EVENING HOURS BEFORE TAPERING OFF FROM NORTH TO SOUTH AROUND MIDNIGHT. MUCH OF THIS SNOW LOOKS TO BE OF THE BORDERLINE IFR/MVFR VARIETY...WITH ACCUMULATIONS OF AN INCH OR SLIGHTLY MORE ACROSS SOUTHERN TAF SITES..DTW/YIP/DET...WITH AMOUNTS LESS FARTHER NORTH. IN-FACT...MBS WILL PROBABLY NOT SEE ANY MEASURABLE SNOWFALL. DRIER LIGHT NORTHERLY WINDS LATE TONIGHT LOOK TO CLEAR OUT MUCH OF THE LOW CLOUDS...INTO TOMORROW. FOR DTW...LIGHT SNOW SHOULD BE ONGOING AT START OF 18Z TAF PERIOD...CONTINUING THROUGH THIS EVENING...WITH PROLONGED PERIOD OF 2SM SNOW LEADING TO ACCUMULATIONS OF 1 TO 1.5 INCHES BEFORE SNOW ENDS AROUND OR SHORTLY AFTER MIDNIGHT. WINDS BECOMING A BIT MORE NORTHERLY OVERNIGHT EXPECTED TO LEAD TO SOME CLEARING...BUT COLD FLOW OFF LAKE HURON COULD PROLONG CEILINGS A BIT LONGER THAN FORECASTED. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CEILING AOB 5000 FEET THROUGH THIS EVENING...MEDIUM TONIGHT...LOW TOMORROW * HIGH FOR SNOW AS PRECIPITATION TYPE. && .PREV DISCUSSION...ISSUED 1000 AM EST THU MAR 3 2016 UPDATE... UPDATE SEND TO GRIDS/TEXT PRODUCTS AS FLURRIES HAVE BEGUN TO FALL IN ADRIAN WITH 3/2 MILE VSBY JUST UPSTREAM AT HILLSDALE ALREADY. THE EARLIER TIMING CORRESPONDS WITH A NORTHWARD MOISTURE SURGE EVIDENT ON WV/RADAR COMPOSITE OVERLAY. 13Z RAP CAPTURES THIS AND SUGGESTS MID-LEVEL THETA-E ADVECTION IS A BIT MORE ROBUST THAN PREVIOUSLY THOUGHT. IN ADDITION, THE SHORTWAVE OVER NORTHERN LAKE MICHIGAN AT 1445Z IS QUITE A BIT STRONGER THAN ADVERTISED IN MODEL PROGS. THIS FEATURE WILL BE TRANSIENT IN NATURE, EXITING TO THE EAST BY EARLY AFTERNOON. HOWEVER, IT IS LIKELY PROVIDING A BOOST TO THE BACKGROUND FORCING FIELD AS WELL AS PROVIDING SOME ENHANCEMENT TO MOIST ISENTROPIC ASCENT ACROSS LOWER MICHIGAN. GIVEN THE DRY NATURE OF THE 12Z DTX SOUNDING, ANYTHING THAT SPEEDS UP THE MOISTENING PROCESS IS A PLUS IN TERMS OF POTENTIAL SNOW COVERAGE AND ACCUMS. STILL SOME QUESTION AS TO HOW QUICKLY ACTIVITY WILL SPREAD NORTHEAST, SO TIMING REMAINS ON THE CONSERVATIVE SIDE FURTHER NORTH FROM 8 MILE. NONETHELESS, THE AFOREMENTIONED OBSERVATIONS SUPPORT THE 12Z NAM AND ESPECIALLY 13Z RAP IN A MORE AGGRESSIVE FORECAST FOR THE REMAINDER OF THE DAY. NOW ADVERTISING ABOUT 3" SOUTH OF I-94 WITH UP TO AN INCH POSSIBLE AS FAR NORTH AS I-69. PREV DISCUSSION...ISSUED 349 AM EST THU MAR 3 2016 DISCUSSION... ACTIVE WEATHER PATTERN WILL CONTINUE RIGHT INTO THE WEEKEND AS MULTIPLE WAVES TRAVERSE ACROSS THE REGION. UPPER LEVEL TROUGH CONTINUES TO ALLOW THESE WAVES TO QUICKLY DIVE SOUTH WITH THE FIRST WAVE CURRENTLY COMING ACROSS THE SOUTHERN PLAINS. THE LOW PRESSURE SYSTEM IN RESPONSE WILL ALLOW THE NORTHERN EDGE OF THE PRECIP FIELD TO MOVE OVER SOUTHERN PORTION OF THE CWA AS THE INVERTED TROUGH SLIDES ACROSS THE AREA. THIS EDGE AT PRESS TIME WAS DROPPING LIGHT SNOW OVER NORTHERN ILLINOIS/NORTHWEST INDIANA AND WILL SLOWLY EASE EAST THROUGH THE MORNING HOURS. 00Z MODEL SUITE HAS COME IN WITH A SLOWER ONSET OF THE SNOW SHOWERS AND A SLIGHT SOUTHERLY SHIFT IN THE TRACK. THE 00Z SOUNDING FROM DTX ALSO SUPPORTS A LATER ONSET GIVEN THE AMOUNT OF DRY AIR IN THE COLUMN. PRECIP WILL SLOWLY SATURATE THROUGH THE MORNING HOURS WITH THE MAJORITY OF THE SNOW SHOWERS FALLING IN THE AFTERNOON/EARLY EVENING. STILL EXPECTING SNOW ACCUMULATIONS OF BETWEEN 1-2 INCHES FOR LOCATIONS SOUTH OF DETROIT WITH 0.5-1 INCH POSSIBLE BETWEEN DETROIT AND FLINT. HIGHEST SNOWFALL ACCUMULATIONS EXPECTED TO BE FOR LOCATIONS CLOSER TO THE OHIO BORDER. A BRIEF BREAK WILL COME ON FRIDAY AS SURFACE HIGH PRESSURE BUILDS IN BETWEEN THE TWO WAVES. UPPER LEVEL RIDGING BUILDING IN OVERHEAD ON FRIDAY WILL SLOWLY GIVE WAY AS THE SECOND WAVE MOVES SOUTH FROM THE NORTHERN PLAINS ON SATURDAY. THIS IS WHERE SOUTHEASTERN MICHIGAN WILL SEE YET ANOTHER CHANCE FOR PRECIPITATION. ONE CONCERN WITH THIS SYSTEM IS THE PRECIP TYPE AND HAVE INTRODUCED A RAIN/SNOW MIX DURING THE AFTERNOON HOURS ON SATURDAY FOR ROUGHLY THE SOUTHERN THIRD OF THE FORECAST AREA. TEMPS LOOK TO HOVER JUST ABOVE FREEZING IN THE AFTERNOON AS SOUTHERLY FLOW BRINGS IN THE WARMER TEMPS ALTHOUGH THIS WILL BE DEPENDENT ON THE TRACK OF THE LOW. WITH THIS SYSTEM... THE AREA IS LOOKING AT POTENTIAL FOR ANOTHER INCH OR TWO OF SNOW ONCE IT IS ALL SAID AND DONE. THE SYSTEM WILL QUICKLY EXIT OFF TO THE SOUTHEAST SATURDAY NIGHT AS HIGH PRESSURE ONCE AGAIN TAKES OVER FOR THE REMAINDER OF THE WEEKEND. MORE SUBSTANTIAL CHANGES COME TO THE UPPER LEVELS STARTING NEXT WEEK. MODEST RIDGING BUILDS IN OVER THE PLAINS AS STRONG HIGH PRESSURE HOLDS OVER THE SOUTHEAST CONUS. THIS WILL PUT SOUTHEASTERN MICHIGAN ON THE NORTHERN EDGE OF THE HIGH. WAA ADVECTION WILL COMMENCE AND BRING ABOVE NORMAL TEMPS BACK TO SOUTHEAST MICHIGAN. HOWEVER...WHILE TEMPS WILL BE ON THE WARMER SIDE COMPARED TO WHAT THEY HAVE BEEN...MODELS ARE HINTING AT ANOTHER ACTIVE STRETCH OF WEATHER AS A BOUNDARY SETS UP RIGHT OVER THE AREA. MARINE... A WEAK PRESSURE GRADIENT OVER THE GREAT LAKES REGION WILL ENSURE LIGHT TO MODERATE WINDS THROUGH THE WEEKEND. SOUTHWEST RETURN FLOW WILL EVENTUALLY DEVELOP SUNDAY NIGHT AND MONDAY AS LARGE SURFACE HIGH RETREATS TO THE ATLANTIC SEABOARD. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....SF UPDATE.......JVC DISCUSSION...SS MARINE.......CB YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1000 AM EST THU MAR 3 2016 .UPDATE... UPDATE SEND TO GRIDS/TEXT PRODUCTS AS FLURRIES HAVE BEGUN TO FALL IN ADRIAN WITH 3/2 MILE VSBY JUST UPSTREAM AT HILLSDALE ALREADY. THE EARLIER TIMING CORRESPONDS WITH A NORTHWARD MOISTURE SURGE EVIDENT ON WV/RADAR COMPOSITE OVERLAY. 13Z RAP CAPTURES THIS AND SUGGESTS MID-LEVEL THETA-E ADVECTION IS A BIT MORE ROBUST THAN PREVIOUSLY THOUGHT. IN ADDITION, THE SHORTWAVE OVER NORTHERN LAKE MICHIGAN AT 1445Z IS QUITE A BIT STRONGER THAN ADVERTISED IN MODEL PROGS. THIS FEATURE WILL BE TRANSIENT IN NATURE, EXITING TO THE EAST BY EARLY AFTERNOON. HOWEVER, IT IS LIKELY PROVIDING A BOOST TO THE BACKGROUND FORCING FIELD AS WELL AS PROVIDING SOME ENHANCEMENT TO MOIST ISENTROPIC ASCENT ACROSS LOWER MICHIGAN. GIVEN THE DRY NATURE OF THE 12Z DTX SOUNDING, ANYTHING THAT SPEEDS UP THE MOISTENING PROCESS IS A PLUS IN TERMS OF POTENTIAL SNOW COVERAGE AND ACCUMS. STILL SOME QUESTION AS TO HOW QUICKLY ACTIVITY WILL SPREAD NORTHEAST, SO TIMING REMAINS ON THE CONSERVATIVE SIDE FURTHER NORTH FROM 8 MILE. NONETHELESS, THE AFOREMENTIONED OBSERVATIONS SUPPORT THE 12Z NAM AND ESPECIALLY 13Z RAP IN A MORE AGGRESSIVE FORECAST FOR THE REMAINDER OF THE DAY. NOW ADVERTISING ABOUT 3" SOUTH OF I-94 WITH UP TO AN INCH POSSIBLE AS FAR NORTH AS I-69. && .AVIATION...ISSUED 651 AM EST THU MAR 3 2016 RESIDUAL DRY AIR IN THE LOWEST 6000 FT AGL WILL MAKE IT DIFFICULT FOR PRECIPITATION TO MOVE INTO FAR SOUTHEASTERN MICHIGAN THIS MORNING. OBSERVATIONAL TRENDS SUPPORT A HIGH AMOUNT OF VIRGA ON ADJACENT RADARS WHICH MAY MAKE IT DIFFICULT TO PIN DOWN ONSET TIMING AT THE DETROIT METRO TERMINAL. REALLY LOOKING FOR VFR CONDITIONS IN BOTH CIGS/VSBYS TO HOLD ON RIGHT INTO THE LATE AFTERNOON HOURS. WARM ADVECTION WILL THEN INCREASE BY THE EVENING RUSH WHICH WILL SUPPORT LIGHT ACCUMULATING SNOW AT THE SOUTHERN TERMINALS. WILL CONTINUE TO BE OPTIMISTIC AND SUPPORT LIGHT SNOW AS FAR NORTH AS FNT...BUT WILL REMOVE FROM MBS. PEAK OF THE POTENTIAL WILL BE IN THE 21-03Z TIMEFRAME WHERE HAS MUCH AS AN INCH OF SNOW WILL BE POSSIBLE AT THE DETROIT TERMINALS. FOR DTW... VFR CIGS WILL LOWER TO MVFR/IFR DURING THE AFTERNOON AS SNOW INCREASES COVERAGE AND INTENSITY. ABOUT 1 INCH OF DRY SNOW ACCUMULATION IS EXPECTED BY LATE THURSDAY EVENING. THERE ARE INDICATIONS THAT IFR CEILING HEIGHTS WILL AT LEAST APPROACH SOUTHEASTERN MICHIGAN FROM THE SOUTHWEST ESPECIALLY 23-03Z. CONFIDENCE IS LOW ATTM. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CIG AOB 5 KFT LATE MORNING THROUGH THURSDAY EVENING. * HIGH FOR SNOW AS PRECIPITATION TYPE DURING AFTERNOON AND EVENING. && .PREV DISCUSSION...ISSUED 349 AM EST THU MAR 3 2016 DISCUSSION... ACTIVE WEATHER PATTERN WILL CONTINUE RIGHT INTO THE WEEKEND AS MULTIPLE WAVES TRAVERSE ACROSS THE REGION. UPPER LEVEL TROUGH CONTINUES TO ALLOW THESE WAVES TO QUICKLY DIVE SOUTH WITH THE FIRST WAVE CURRENTLY COMING ACROSS THE SOUTHERN PLAINS. THE LOW PRESSURE SYSTEM IN RESPONSE WILL ALLOW THE NORTHERN EDGE OF THE PRECIP FIELD TO MOVE OVER SOUTHERN PORTION OF THE CWA AS THE INVERTED TROUGH SLIDES ACROSS THE AREA. THIS EDGE AT PRESS TIME WAS DROPPING LIGHT SNOW OVER NORTHERN ILLINOIS/NORTHWEST INDIANA AND WILL SLOWLY EASE EAST THROUGH THE MORNING HOURS. 00Z MODEL SUITE HAS COME IN WITH A SLOWER ONSET OF THE SNOW SHOWERS AND A SLIGHT SOUTHERLY SHIFT IN THE TRACK. THE 00Z SOUNDING FROM DTX ALSO SUPPORTS A LATER ONSET GIVEN THE AMOUNT OF DRY AIR IN THE COLUMN. PRECIP WILL SLOWLY SATURATE THROUGH THE MORNING HOURS WITH THE MAJORITY OF THE SNOW SHOWERS FALLING IN THE AFTERNOON/EARLY EVENING. STILL EXPECTING SNOW ACCUMULATIONS OF BETWEEN 1-2 INCHES FOR LOCATIONS SOUTH OF DETROIT WITH 0.5-1 INCH POSSIBLE BETWEEN DETROIT AND FLINT. HIGHEST SNOWFALL ACCUMULATIONS EXPECTED TO BE FOR LOCATIONS CLOSER TO THE OHIO BORDER. A BRIEF BREAK WILL COME ON FRIDAY AS SURFACE HIGH PRESSURE BUILDS IN BETWEEN THE TWO WAVES. UPPER LEVEL RIDGING BUILDING IN OVERHEAD ON FRIDAY WILL SLOWLY GIVE WAY AS THE SECOND WAVE MOVES SOUTH FROM THE NORTHERN PLAINS ON SATURDAY. THIS IS WHERE SOUTHEASTERN MICHIGAN WILL SEE YET ANOTHER CHANCE FOR PRECIPITATION. ONE CONCERN WITH THIS SYSTEM IS THE PRECIP TYPE AND HAVE INTRODUCED A RAIN/SNOW MIX DURING THE AFTERNOON HOURS ON SATURDAY FOR ROUGHLY THE SOUTHERN THIRD OF THE FORECAST AREA. TEMPS LOOK TO HOVER JUST ABOVE FREEZING IN THE AFTERNOON AS SOUTHERLY FLOW BRINGS IN THE WARMER TEMPS ALTHOUGH THIS WILL BE DEPENDENT ON THE TRACK OF THE LOW. WITH THIS SYSTEM... THE AREA IS LOOKING AT POTENTIAL FOR ANOTHER INCH OR TWO OF SNOW ONCE IT IS ALL SAID AND DONE. THE SYSTEM WILL QUICKLY EXIT OFF TO THE SOUTHEAST SATURDAY NIGHT AS HIGH PRESSURE ONCE AGAIN TAKES OVER FOR THE REMAINDER OF THE WEEKEND. MORE SUBSTANTIAL CHANGES COME TO THE UPPER LEVELS STARTING NEXT WEEK. MODEST RIDGING BUILDS IN OVER THE PLAINS AS STRONG HIGH PRESSURE HOLDS OVER THE SOUTHEAST CONUS. THIS WILL PUT SOUTHEASTERN MICHIGAN ON THE NORTHERN EDGE OF THE HIGH. WAA ADVECTION WILL COMMENCE AND BRING ABOVE NORMAL TEMPS BACK TO SOUTHEAST MICHIGAN. HOWEVER...WHILE TEMPS WILL BE ON THE WARMER SIDE COMPARED TO WHAT THEY HAVE BEEN...MODELS ARE HINTING AT ANOTHER ACTIVE STRETCH OF WEATHER AS A BOUNDARY SETS UP RIGHT OVER THE AREA. MARINE... A WEAK PRESSURE GRADIENT OVER THE GREAT LAKES REGION WILL ENSURE LIGHT TO MODERATE WINDS THROUGH THE WEEKEND. SOUTHWEST RETURN FLOW WILL EVENTUALLY DEVELOP SUNDAY NIGHT AND MONDAY AS LARGE SURFACE HIGH RETREATS TO THE ATLANTIC SEABOARD. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......JVC AVIATION.....CB DISCUSSION...SS MARINE.......CB YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
307 AM EST THU MAR 3 2016 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 412 PM EST WED MAR 2 2016 WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL LOW NEAR JAMES BAY RESULTING IN CONFLUENT NW FLOW THROUGH THE NRN LAKES. AT THE SFC...A RIDGE EXTENDED FROM NRN ONTARIO TO THE OHIO VALLEY. HOWEVER LAKE INDUCED TROUGHING HAD DEVELOPED ACROSS PORTIONS OF THE WRN LAKES. WITH THE LIGHT NRLY FLOW OVER THE REGION...LOW LEVEL CONV OVER ERN LAKE SUPERIOR ALONG WITH 850 MB TEMPS AROUND -18C SUPPORTED SCT LES FROM ERN ALGER COUNTY INTO LUCE COUNTY. TONIGHT...HIGH RES MODELS SUGGEST THAT THE WEAK PRES GRADIENT WILL FAVOR DEVELOPMENT OF TROUGHING OR EVEN A MESO-LOW OVER ERN LAKE SUPERIOR. THE LIGHT LES INTO ERN CWA SHOULD CONTINUE INTO THIS EVENING BEFORE LAND BREEZES AND LAKE INDUCED CIRCULATIONS BECOME MORE PROMINENT. CONFIDENCE IN WHERE THE LES NEAR THE ERN CWA SHORELINE WILL DEVELOP IS LOW BUT THE DRY AIRMASS OVER THE REGION AND INVERSION HEIGHTS REMAINING AOB 5K FT WILL LIMIT THE INTENSITY WITH ANY ACCUMULATIONS LESS THAN AN INCH. OTHERWISE...PARTLY CLOUDY SKIES WILL ALLOW ENOUGH RADIATIONAL COOLING FOR TEMPS TO DROP TOWARD THE LOWER END OF GUIDANCE...ESPECIALLY OVER THE EAST. THURSDAY...HIGH PRES WILL CONTINUE TO DOMINATE THE REGION WITH DRY WEATHER AND LIGHT WINDS PREVAILING. ANY LES ON LAKE SUPERIOR SHOULD REMAIN OFF SHORE. HOWEVER...A LIGHT S TO SE FLOW FROM LAKE MI MAY BRING SOME SNOW SHOWERS TOWARD THE GARDEN PENINSULA OR SRN SCHOOLCRAFT COUNTY. AGAIN IN THE WEAK FLOW ENVIRONMENT...CONFIDENCE IN THE TIMING/LOCATIONS OF ANY LES THAT WILL AFFECT THE CWA IS LOW. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 307 AM EST THU MAR 3 2016 NAM SHOWS THE UPPER AIR PATTERN CONSISTING OF A SHORTWAVE OVER THE NORTHERN PLAINS 12Z FRI THAT MOVES SOUTHEAST INTO THE UPPER GREAT LAKES FRI NIGHT AND INTO THE LOWER GREAT LAKES ON SAT. RIDGING THEN BUILDS INTO THE PLAINS SAT NIGHT. NAM SHOWS DEEPER MOISTURE AND 850- 500 MB Q-VECTOR CONVERGENCE MOVING INTO THE AREA FRI AFTERNOON AND THE CONVERGENCE MOVES OUT FRI NIGHT. GFS AND ECMWF SHOW ABOUT THE SAME THING AS WELL. STILL LOOKS LIKE THERE COULD BE A 1-3 INCH SNOWFALL ACROSS THE CWA FRI AFTERNOON AND FRI NIGHT AND STILL KEPT IN CHANCE TO LIKELY POPS IN THE CWA WITH THE SNOW MOVING OUT SAT MORNING. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE PLAINS 12Z SUN THAT MOVES TO THE EAST HALF OF THE U.S. 12Z MON. MEANWHILE...A BROAD 500 MB TROUGH MOVES INTO THE WESTERN U.S. THE TROUGH MOVES INTO THE ROCKIES 12Z TUE WITH A SHORTWAVE EJECTING OUT OF IT INTO THE NORTHERN PLAINS. A BROAD 500 MB TROUGH THEN MOVES INTO THE SOUTHERN PLAINS 12Z WED. TEMPERATURES WILL REMAIN ABOVE NORMAL THIS FORECAST PERIOD WITH THE PCPN BEING MOSTLY RAIN AS IT IS WARM ENOUGH EVEN AT NIGHT FOR IT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1142 PM EST WED MAR 2 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT ALL TAF SITES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 412 PM EST WED MAR 2 2016WEAK PRESSURE GRADIENT RESULTS IN WINDS LESS THAN 25 KTS THROUGH SAT. SOUTHWEST WINDS COULD INCREASE TO 30 KTS ON SUN OVER EASTERN LAKE SUPERIOR AS A DEEP LOW PRESSURE SYSTEM CROSSING FROM MANITOBA INTO ONTARIO INCREASES PRESSURE GRADIENT. WINDS ARE EXPECTED TO DROP BLO 25 KTS BY MON AS GRADIENT WEAKENS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...07 AVIATION...VOSS MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1143 PM EST WED MAR 2 2016 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 412 PM EST WED MAR 2 2016 WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL LOW NEAR JAMES BAY RESULTING IN CONFLUENT NW FLOW THROUGH THE NRN LAKES. AT THE SFC...A RIDGE EXTENDED FROM NRN ONTARIO TO THE OHIO VALLEY. HOWEVER LAKE INDUCED TROUGHING HAD DEVELOPED ACROSS PORTIONS OF THE WRN LAKES. WITH THE LIGHT NRLY FLOW OVER THE REGION...LOW LEVEL CONV OVER ERN LAKE SUPERIOR ALONG WITH 850 MB TEMPS AROUND -18C SUPPORTED SCT LES FROM ERN ALGER COUNTY INTO LUCE COUNTY. TONIGHT...HIGH RES MODELS SUGGEST THAT THE WEAK PRES GRADIENT WILL FAVOR DEVELOPMENT OF TROUGHING OR EVEN A MESO-LOW OVER ERN LAKE SUPERIOR. THE LIGHT LES INTO ERN CWA SHOULD CONTINUE INTO THIS EVENING BEFORE LAND BREEZES AND LAKE INDUCED CIRCULATIONS BECOME MORE PROMINENT. CONFIDENCE IN WHERE THE LES NEAR THE ERN CWA SHORELINE WILL DEVELOP IS LOW BUT THE DRY AIRMASS OVER THE REGION AND INVERSION HEIGHTS REMAINING AOB 5K FT WILL LIMIT THE INTENSITY WITH ANY ACCUMULATIONS LESS THAN AN INCH. OTHERWISE...PARTLY CLOUDY SKIES WILL ALLOW ENOUGH RADIATIONAL COOLING FOR TEMPS TO DROP TOWARD THE LOWER END OF GUIDANCE...ESPECIALLY OVER THE EAST. THURSDAY...HIGH PRES WILL CONTINUE TO DOMINATE THE REGION WITH DRY WEATHER AND LIGHT WINDS PREVAILING. ANY LES ON LAKE SUPERIOR SHOULD REMAIN OFF SHORE. HOWEVER...A LIGHT S TO SE FLOW FROM LAKE MI MAY BRING SOME SNOW SHOWERS TOWARD THE GARDEN PENINSULA OR SRN SCHOOLCRAFT COUNTY. AGAIN IN THE WEAK FLOW ENVIRONMENT...CONFIDENCE IN THE TIMING/LOCATIONS OF ANY LES THAT WILL AFFECT THE CWA IS LOW. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 352 PM EST WED MAR 2 2016 BY 00Z FRIDAY...SFC HIGH PRESSURE WILL BE CENTERED ALONG THE U.S./CANADIAN BORDER BETWEEN THE NEW ENGLAND STATES AND FAR SE ONTARIO AND S QUEBEC. CLOSER TO HOME...WEAK LOW PRESSURE JUST NW OF LAKE SUPERIOR WILL SLIDE OVER CENTRAL AND E LAKE SUPERIOR THURSDAY NIGHT AND BE ACCENTUATED BY AN ELONGATED SHORTWAVE SLIDING IN ON THE NW FLOW ALOFT. THE SFC LOW WILL BRING THE BEST CHANCE FOR LAKE EFFECT SNOW SHOWERS TO THE KEWEENAW PENINSULA 09Z-21Z FRIDAY...AS 850MB TEMPS HOVER AROUND -12C. WAA TAKES HOLD OVER UPPER MI FRIDAY AFTERNOON...AHEAD OF A WARM FRONT NEARING FROM A SFC LOW ACROSS E ND/W MN. WAA SNOW WILL INVADE W UPPER MI LATE IN THE DAY AS THE SFC LOW MOVES OVER CENTRAL MN AND 850MB TEMPS RISE TO AROUND -8C. WHILE MOST SOLUTIONS INDICATE THE SFC LOW SINKING ACROSS CENTRAL WI FRIDAY NIGHT...WITH AN INVERTED TROUGH MOVING OVER UPPER MI/LAKE SUPERIOR...THERE IS AN OUTLIER BRINGING THE LOW ACROSS LAKE SUPERIOR. WILL CONTINUE OUR FCST WITH A CONSENSUS APPROACH...SHIFTING THE LOW ACROSS S WI BY 12Z SATURDAY. THIS WOULD BRING THE HIGHEST PRECIP TO AREAS ALONG THE WI BORDER WHERE 850MB TEMPS OF -5 TO -7C. STILL LOOKS LIKE THE PRECIPITATION SHOULD REMAIN IN THE FORM OF ALL SNOW. QPF TOTALS LOOK TO BE AROUND 0.10 INCHES TO AROUND 0.20 INCHES WITH THE HEAVIEST EXPECTED ALONG THE WI BORDER WHERE THE BETTER FORCING WILL BE LOCATED. THESE QPF TOTALS WITH AROUND 13 TO 15 TO SNOW TO LIQUID RATIOS WILL GIVE SNOWFALL TOTALS AROUND 1 TO 3 INCHES. AGAIN THE HEAVIEST SNOWFALL TOTALS ARE EXPECTED NEAR THE WI BORDER. HIGH PRESSURE WILL BUILD IN AT THE SFC SATURDAY AFTERNOON- EVENING...WITH ONLY A BRIEF TURN OF THE SFC WINDS OUT OF THE NW. BUT WITH 850MB TEMPS ONLY AROUND -8C OVER THE E HALF...NOT EXPECTING MUCH MORE THAN CLOUD COVER AND A FEW LIGHT SNOW SHOWERS...THROUGH EARLY AFTERNOON. WAA WILL BE MORE IMPRESSIVE SATURDAY NIGHT INTO SUNDAY AS THE SFC LOW EXITS E AND RIDGING BUILDS IN ALOFT. 850MB TEMPS BY 18Z SUNDAY WILL INCREASE TO 0 TO 6C /HIGHEST OFF THE GFS AS IT INDICATES 850MB W-SW FLOW OF 40-55KTS THAT WILL CONTINUE THROUGH 06Z MONDAY/. EXPECT THE NEXT ROUND OF PRECIP TO START SUNDAY EVENING AS RAIN. THERE ARE SOME DISCREPANCIES IN THE TIMING OF THE SMALLER SCALE DISTURBANCES...SO WILL NOT GO TOO HIGH WITH POPS. A REBOUNDING 500MB RIDGE OVERHEAD SUNDAY NIGHT-MONDAY AND LOW PRESSURE ORGANIZING ACROSS THE PLAINS STATES WILL ALLOW FOR EVEN INCREASED WAA INTO THE UPPER GREAT LAKES. BY 12Z TUESDAY 850MB TEMPS WILL LIKELY BE NEAR 8C...ALLOWING SFC TEMPS TO RISE TO NEAR 50F. WITH A STACKED SFC- 500MB LOW ACROSS THE E DAKOTAS AND W MN BY EARLY AFTERNOON...IT COULD BE AN INTERESTING AFTERNOON ACROSS THE UPPER GREAT LAKES. WILL WAIT UNTIL FCST SOLUTIONS GET MORE IN LINE BEFORE JUMPING ON ANY SIGNIFICANT SHOWERS...OR POSSIBLY EVEN A FEW THUNDERSTORMS. AT THIS POINT THE SFC LOW LOOKS TO EJECT NE...SLIDING JUST NW OF LAKE SUPERIOR TUESDAY EVENING-EARLY WEDNESDAY MORNING. THE S END OF THE LOW LOOKS TO INTENSIFY AND MOVE OVER WI/UPPER MI ON WEDNESDAY. THERE ARE SOME TIMING DIFFERENCES THAT AVERAGE NEARLY 12HRS. COULD BE A WET AND WARM PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1142 PM EST WED MAR 2 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT ALL TAF SITES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 412 PM EST WED MAR 2 2016WEAK PRESSURE GRADIENT RESULTS IN WINDS LESS THAN 25 KTS THROUGH SAT. SOUTHWEST WINDS COULD INCREASE TO 30 KTS ON SUN OVER EASTERN LAKE SUPERIOR AS A DEEP LOW PRESSURE SYSTEM CROSSING FROM MANITOBA INTO ONTARIO INCREASES PRESSURE GRADIENT. WINDS ARE EXPECTED TO DROP BLO 25 KTS BY MON AS GRADIENT WEAKENS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KEC/KF AVIATION...VOSS MARINE...JLB
THROUGH MOST OF THE WEEK. THE PREVIOUS FORECAST DISCUSSION HAD A
GOOD HANDLE ON THE SITUATION AND RELEVANT PORTIONS ARE ATTACHED
BELOW... /DL/ THE WARM AND DRY WEATHER WILL LAST INTO MONDAY BUT RAIN CHANCES LOOK TO RETURN OVER OUR WESTERN ZONES MONDAY NIGHT. RIDGING ALOFT WILL STRENGTHEN JUST EAST OF OUR AREA MONDAY IN RESPONSE TO A DEEPENING UPPER LEVEL LOW OVER THE WESTERN CONUS. THIS RIDGING WILL COMBINE WITH SURFACE OVER THE SOUTHEAST STATES TO REMAIN DOMINANT OVER OUR CWA MONDAY INTO MONDAY NIGHT BUT WAA OVER THE SOUTHERN PLAINS AHEAD OF LARGE CLOSED LOW DROPPING OVER MEXICO WILL RESULT IN CONVECTION SPREADING INTO OUR CWA FROM THE WEST MONDAY NIGHT. WAA AHEAD OF THE CLOSED LOW WILL INCREASE OVER OUR CWA TUESDAY. OUR PWATS WILL INCREASE FROM JUST OVER AN INCH TO NEAR AN INCH AND THREE QUARTERS BY TUESDAY EVENING GENERALLY WEST OF THE MISSISSIPPI RIVER WHICH WOULD BE A MAXIMUM FOR THIS TIME OF THE YEAR. WIND FIELDS WILL INCREASE AND COMBINE WITH INSTABILITY TO RESULT IN SEVERE STORM POTENTIAL. BIGGEST CHANGE FROM LAST NIGHT`S RUN IS THAT THIS FOCUS APPEARS TO BE FARTHER WEST TUESDAY AFFECTING MAINLY OUR WESTERN MOST ZONES. THERE ALSO EXISTS BOTH THE POTENTIAL FOR LOCALLY HEAVY RAIN AS WELL AS THE TRAINING OF STORMS OVER THE SAME AREA WITH THIS SYSTEM. MODELS REMAIN IN AGREEMENT THAT THIS LOW WILL BE VERY SLOW TO MOVE OUT OF THE REGION PERHAPS NOT UNTIL SATURDAY. AS THE THIS CLOSED LOW SHIFTS EAST TO SOUTHERN TEXAS THURSDAY AND THEN NORTHEAST TOWARD THE ARKLATEX REGION FRIDAY THE MAIN FEED OF MOIST GULF AIR AND STORM TRAJECTORIES WILL SET UP ACROSS OUR CWA. THIS WILL PROLONG THE POTENTIAL FOR HEAVY RAIN AND STRONG TO SEVERE STORMS ACROSS PORTIONS OF OUR CWA WEDNESDAY INTO FRIDAY. /22/ AVIATION...VFR CONDITIONS ARE PREVAILING THIS AFTERNOON. NORTHERLY WINDS OF 5-9 KTS THIS AFTERNOON WILL DIMINISH THIS EVENING AND TONIGHT. LIGHT TO CALM WINDS AND CLEAR SKIES MAY LEAD TO SOME PATCHY FOG OVERNIGHT/EARLY SATURDAY MORNING THOUGH HIGH CLOUDS MAY HAMPER THIS. THIS WILL BE MONITORED IN LATER TAF ISSUANCES. PLEASANT WEATHER WILL CONTINUE THROUGH THE WEEKEND. /28/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 43 72 42 73 / 0 0 0 0 MERIDIAN 39 70 38 71 / 0 0 0 0 VICKSBURG 45 74 43 74 / 0 0 0 0 HATTIESBURG 44 72 43 74 / 0 0 0 0 NATCHEZ 46 73 46 74 / 0 0 0 0 GREENVILLE 42 68 43 69 / 0 0 0 0 GREENWOOD 40 69 40 70 / 0 0 0 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ JAN/
AREA FORECAST DISCUSSION...UPDATE
NWS JACKSON MS
1025 AM CST THU MAR 3 2016 .UPDATE... SHOWERS AND EMBEDDED THUNDERSTORMS ARE STREAMING FROM WEST TO EAST ACROSS CENTRAL AND EAST-CENTRAL MS CURRENTLY...IN RESPONSE TO AN INCOMING POTENT WEATHER DISTURBANCE ACTIVATING A BAROCLINIC ZONE RUNNING FROM THE ARKLATEX ESE TOWARD THE CENTRAL GULF COAST. SURFACE LOW PRESSURE DEEPENING OFF TO OUR WEST SHOULD MOVE INTO THE HEART OF THE REGION THIS AFTERNOON AND HELP KINK SAID BAROCLINIC ZONE...BRIEFLY HELPING TO CONGREGATE DEEP LOW LEVEL INSTABILITY A LITTLE INLAND OF THE GULF COAST. THIS ZONE SHOULD EXTEND NORTH INTO MY SOUTHEAST ZONE THIS AFTERNOON AND HERE WIND SHEAR SHOULD BE SUFFICIENT FOR ORGANIZED THUNDERSTORMS ASSOCIATED WITH A NON-ZERO TORNADO POTENTIAL. LATEST HRRR RUNS BEAR OUT THIS POTENTIAL WELL...ALTHOUGH IT DOES LOOK LIKE LIKELIHOOD OF SEVERE ACTIVITY MAY INCREASE AS SURFACE-BASED CONVECTION BEGINS TO TRANSITION SOUTHEAST OF OUR FORECAST AREA LATE THIS AFTERNOON. ALL THIS BEING SAID...THE LIMITED RISK OF SEVERE THUNDERSTORMS PREVIOUSLY POSTED IN THE HWO/GRAPHICS FOR OUR SE ZONES LOOKS GOOD...ALTHOUGH WE DID UPDATE TIMING TO FOCUS MORE ON THIS AFTERNOON AND WE ALSO INCLUDED SOME WORDING RELATED TO THE SMALL POSSIBILITY OF A TORNADO IN THAT NECK-OF-THE-WOODS. OTHERWISE...EXPECT A CONTINUED SMATTERING OF SHOWERS AND EMBEDDED THUNDERSTORMS THROUGH THE AFTERNOON (ESPECIALLY OVER MS COUNTIES) AS IMPRESSIVE LIFT FROM THE INCOMING DISTURBANCE MAKES ITS PRESENCE FELT. VERY CHILLY TEMPERATURES ALOFT ASSOCIATED WITH THE DISTURBANCE IS HELPING TO INCREASE 700 TO 500 MB TEMP LAPSE RATES...DELIVERING ELEVATED INSTABILITY EVEN WHERE THE SURFACE REMAINS COOL. IN MANY AREAS THIS COMBO OF ELEVATED INSTABILITY AND COLD AIR ALOFT WILL YIELD SOME SMALL HAIL POTENTIAL AS WE GO THROUGH THE AFTERNOON...EVEN TO THE NORTH OF OUR LIMITED SVR RISK AREA IN SE MS. FORTUNATELY...THINKING IS THAT TRULY SEVERE HAIL WITH ANY OF THESE STORMS OUTSIDE OF THE LIMITED RISK WILL BE HARD TO COME BY...BUT OF COURSE WE WILL BE MONITORING THE SITUATION CLOSELY. FINALLY...TEMPS WILL BE TRICKY TODAY WITH A CURRENT LARGE SURFACE TEMP GRADIENT (WARM TO CHILLY) FROM SW TO NE. EXPECT SURFACE TEMPS MAY TRY TO RECOVER QUICKLY FROM MID TO LATE AFTERNOON IN AT LEAST THE SOUTHWEST HALF OF ZONES...ALTHOUGH LOCATIONS IN EAST-CENTRAL MS AND AROUND THE GOLDEN TRIANGLE MAY SEE THE SUN SET TOO SOON TO BENEFIT. THIS UPDATE REFLECTS THIS THINKING. /BB/ && .AVIATION...MVFR CIGS PREVAIL ACROSS THE REGION THIS MORNING DUE TO LOW STRATUS. SCT SHRA WITH SOME EMBEDDED TS ENCOMPASSED MUCH OF CENTRAL MS. THIS ACTIVITY WILL CONTINUE THROUGH THE DAYTIME HOURS AS A COLD FRONT MOVES ACROSS THE REGION. A FEW SEVERE STORMS ARE POSSIBLE. CIGS ARE EXPECTED TO REMAIN IN THE MVFR (OCCASIONALLY IFR) RANGE OVER MOST OF THE AREA THROUGH TONIGHT, IMPROVING TO VFR BY EARLY FRIDAY. AS THE FRONT MOVES THROUGH, WINDS WILL SHIFT FROM S/SE THIS MORNING TO W/NW THIS AFTERNOON INTO TONIGHT AS THE FRONT MOVES SOUTHEASTWARD ACROSS THE AREA. A FEW GUSTS TO AROUND 20 KT ARE POSSIBLE THIS AFTERNOON. /DL/ && .PREV DISCUSSION... /ISSUED 447 AM CST THU MAR 3 2016/ SHORT TERM...TODAY THROUGH SATURDAY MORNING...OVERALL MAIN STORY FOR THE SHORT TERM PERIOD ARE THE RAIN AND STORM CHANCES MOVING IN THIS MORNING TO AFTERNOON BEFORE A QUIETER AND DRIER PERIOD IN STORE GOING INTO THE WEEKEND. FAST MOVING S/WV MOVING INTO SRN AR IS BRINGING A MCS INTO THE NW DELTA EARLY THIS MORNING. DUE TO VERY LOW DEWPOINTS IN THE UPPER 30S ACROSS MOST OF THE REGION...THIS WILL LIKELY REMAIN ELEVATED BUT SOME OCCASIONAL PRECIP LOADING COULD BRING DOWN SOME QUICK GUSTY WINDS. THIS IS IN RESPONSE TO A QUICK MOVING UPPER JET/SFC LOW MOVING INTO NRN TX/SRN OK. EXPECT THIS TO RAPIDLY MOVE TO THE E TODAY AND CONTINUE TO HELP INCREASE LOW LEVEL FLOW AND MOISTURE RETURN WITH DEWPOINTS GETTING INTO THE UPPER 50S/LOWER 60S IN THE S. OVERALL MOST OF THE ACTIVITY TODAY WILL REMAIN TAME DUE TO STRONG LOW LEVEL INVERSION BUT AFTER THE 21Z TIMEFRAME OR SO...THAT INVERSION SHOULD BE MOSTLY MIXED OUT AND SOME LOW LEVEL INSTABILITY...DUE TO STEEP MID-LEVEL LAPSE RATES...WILL BE ABLE TO BE REALIZED. BASED ON HI-RES ARW AND GOOD LOW LEVEL SHEAR...WENT AHEAD AND INTRODUCED A LIMITED IN THE HWO FOR SEVERE IN THE HWY 84 CORRIDOR. ALSO THE HIGHS TODAY WENT A LITTLE ON THE COOLER SIDE DUE TO THE INVERSION STICKING AROUND AWHILE AND OP GFS/EURO BEING MUCH COOLER...WENT A FEW DEGREES COOLER. EXPECT THE ~1010MB SFC LOW AND ASSOCIATED LIFT/RAIN TO MOVE THROUGH AFTER 00Z TONIGHT AND RAIN TO TAPER OFF BETWEEN 03-06Z FRIDAY. AFTER THE SFC LOW MOVES THROUGH...EXPECT NW FLOW AND SFC RIDGING TO BUILD IN AND HELP TO DRY OUT THE AREA AS PW`S FALL TO LESS THAN HALF AN INCH. THIS WILL LEAD TO A MUCH DRIER PATTERN AND CLOUDS WILL CLEAR OUT OF THE AREA FRIDAY AFTERNOON. A NICE AFTERNOON IS IN STORE ON FRIDAY BUT SOME NE SFC WINDS WILL KEEP THE AREA FROM WARMING AS MUCH WITH HIGHS IN THE UPPER 50S IN THE N TO MID/UPPER 60S IN THE S. EXPECT ANOTHER COLD NIGHT IN STORE IN THE MID 30S IN THE E TO LOW 40S IN THE WEST. /DC/ LONG TERM...SATURDAY THROUGH THURSDAY...WARMING TREND BEGINS SATURDAY AND WILL CONTINUE...ALONG WITH DRY WEATHER...THROUGH TUESDAY. A SURFACE RIDGE WILL BE OVER THE SOUTHEAST STATES SATURDAY MORNING RESULTING IN RETURN FLOW OVER OUR CWA BUT THIS WILL BE SHORT LIVED. A NORTHERN STREAM SHORTWAVE TROUGH AND WEAK SURFACE LOW WILL MOVE SOUTHEAST ACROSS THE OHIO VALLEY SATURDAY AND TO THE MID ATLANTIC SEABOARD BY SUNDAY MORNING. THE WEAK DRY TRAILING COLD FRONT WILL DROP SOUTH INTO OUR NORTHEAST ZONES EARLY SUNDAY MORNING BEFORE DISSIPATING. IN ITS WAKE A 1028MB HIGH WILL BECOME CENTERED OVER THE MID MISSISSIPPI RIVER VALLEY PROVIDING A LIGHT DRY NORTHEAST TO EAST FLOW BACK ACROSS OUR CWA SUNDAY. RIDGING ALOFT WILL STRENGTHEN JUST EAST OF OUR AREA IN RESPONSE TO A DEEPENING UPPER LEVEL TROUGH OVER THE WESTERN CONUS SUNDAY INTO MONDAY. RIDGING SURFACE AND ALOFT CENTERED OVER THE EASTERN CONUS WILL REMAIN DOMINANT OVER OUR CWA INTO MONDAY MAINTAINING DRY WEATHER OVER OUR CWA. THIS WILL ALLOW TEMPERATURES TO WARM BACK ABOVE NORMAL BY SUNDAY AND CONTINUE ABOVE NORMAL THROUGH THURSDAY. THE DRY WEATHER WILL NOT LAST THOUGH. MODELS ARE IN DECENT AGREEMENT WITH THE DEVELOPMENT OF A CLOSED LOW OVER MEXICO BY TUESDAY MORNING. WAA AHEAD OF THIS LOW WILL INCREASE OVER OUR CWA TUESDAY. OUR PWATS WILL INCREASE FROM JUST OVER AN INCH TO NEAR AN INCH AND THREE QUARTERS BY TUESDAY EVENING OVER THE WESTERN HALF OF OUR CWA. THIS ANOMALOUS PWAT IS WOULD BE A MAXIMUM FOR THIS TIME OF THE YEAR. WIND FIELDS WILL INCREASE AND COMBINE WITH INSTABILITY TO RESULT IN SEVERE STORM POTENTIAL. THIS EXISTS BOTH THE POTENTIAL FOR HEAVY RAIN AS WELL AS THE TRAINING OF STORMS OVER THE SAME AREA. THE MAIN AREA FOR SEVERE WEATHER TUESDAY AND TUESDAY NIGHT WILL BE WEST OF INTERSTATE 55 AND WL INCLUDE THIS POTENTIAL IN THE HWO. MODELS ARE SLOW TO MOVE THIS CLOSED LOW OUT AND BOTH THE GFS AND THE ECMWF HAVE THE LOW STILL OVER MEXICO THURSDAY EVENING. AS THE LOW SHIFTS EAST TOWARD TEXAS TUESDAY THROUGH THURSDAY THE AXIS OF HEAVIEST RAIN AND SEVERE STORM POTENTIAL WILL SHIFT FARTHER EAST OVER OUR CWA. /22/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 66 44 64 40 / 65 16 1 1 MERIDIAN 61 41 64 37 / 82 24 1 1 VICKSBURG 71 45 65 44 / 51 10 0 1 HATTIESBURG 69 47 68 40 / 66 26 1 1 NATCHEZ 73 47 66 45 / 36 10 1 1 GREENVILLE 65 43 59 42 / 53 10 1 1 GREENWOOD 62 41 60 40 / 68 13 1 1 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ BB/DL/DC/22
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1201 PM CST THU MAR 3 2016 .SHORT TERM: (Through Late This Afternoon) Issued at 316 AM CST Thu Mar 3 2016 Main concern will be timing of precipiation today. Regional radar and water vapor is showing a vort max circulation currently just northwest of Columbia that will continue to move east early this morning. Light rain over central and northeast Missouri as well as west central Illinois is being generated by low level moisture convergence as well as ascent caused by the vort max. Expect that light rain will continue to spread across the area this morning and then end from west to east this afternoon as shortwave trough now back over the Central Plains sweeps across the area. Forecast soundings and surface temperatures from the RAP and other models continue to show that this will be an all rain system. Temperatures will be held in check by the rain and clouds. .LONG TERM: (Tonight through Wednesday) Issued at 310 AM CST Thu Mar 3 2016 Have a dry forecast now through late Sunday as the GFS/ECMWF/NAM are all tracking the system that moves across the Upper Midwest and Great Lakes on Friday night and Saturday will keep precipitation northeast of the CWA. It still appears that we will be going from below normal temperatures on Friday to above normal temperatures on Saturday and Sunday as the upper pattern switches from northwesterly to southwesterly. Both the ECWMF and the GFS are showing persisent southwesterly flow setting up early-mid next week which will allow for plenty of moisture to move northward from the Gulf of Mexico. Will continue the high chance of showers and thunderstorms going beginning Sunday night through Wednesday. Will need to watch the potential for locally heavy rainfall with this system if the front stalls over CWA. Britt && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1151 AM CST Thu Mar 3 2016 A surface low pressure system was located in SW MO at midday with an area of light rain centered from St. Louis into SE MO. The low will move southeastward through the remainder of the afternoon and evening with the rain persisting into early-mid afternoon for the St. Louis area terminals. In the wake of the low pressure system, surface winds will shift to the north-northwest and this will bring an extensive area of stratus out of IA into the area, and will also keep the stratus currently across eastern MO locked in. MVFR flight conditions will be most predominate with KUIN continuing to experiencing IFR through the afternoon. There may be another period again of IFR towards daybreak on Friday morning. Flight conditions should improve to VFR late morning-midday on Friday. Specifics for KSTL: Light rain will persist into early-mid afternoon as a low pressure system tracks to the southeast of the area. In the wake of the low pressure system, surface winds will shift to the north- northwest and this keep the stratus currently across eastern MO locked in. MVFR flight conditions will be most predominate. Flight conditions should improve to VFR late morning-midday on Friday. Glass && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
454 AM CST THU MAR 3 2016 .SHORT TERM: (Through Late This Afternoon) Issued at 316 AM CST Thu Mar 3 2016 Main concern will be timing of precipiation today. Regional radar and water vapor is showing a vort max circulation currently just northwest of Columbia that will continue to move east early this morning. Light rain over central and northeast Missouri as well as west central Illinois is being generated by low level moisture convergence as well as ascent caused by the vort max. Expect that light rain will continue to spread across the area this morning and then end from west to east this afternoon as shortwave trough now back over the Central Plains sweeps across the area. Forecast soundings and surface temperatures from the RAP and other models continue to show that this will be an all rain system. Temperatures will be held in check by the rain and clouds. .LONG TERM: (Tonight through Wednesday) Issued at 310 AM CST Thu Mar 3 2016 Have a dry forecast now through late Sunday as the GFS/ECMWF/NAM are all tracking the system that moves across the Upper Midwest and Great Lakes on Friday night and Saturday will keep precipitation northeast of the CWA. It still appears that we will be going from below normal temperatures on Friday to above normal temperatures on Saturday and Sunday as the upper pattern switches from northwesterly to southwesterly. Both the ECWMF and the GFS are showing persisent southwesterly flow setting up early-mid next week which will allow for plenty of moisture to move northward from the Gulf of Mexico. Will continue the high chance of showers and thunderstorms going beginning Sunday night through Wednesday. Will need to watch the potential for locally heavy rainfall with this system if the front stalls over CWA. Britt && .AVIATION: (For the 12z TAFs through 12z Friday Morning) Issued at 419 AM CST Thu Mar 3 2016 Light rain will move eastward through our area this morning ahead of an upper level disturbance and an inverted surface trough. The light rain should shift east of COU by about 14Z, east of UIN by 17Z, and east of the St Louis metro area by 20Z. The cloud ceiling will drop into the MVFR catagory by late morning. The e-sely surface wind will back around to a nly direction by late morning in UIN and COU and during the afternoon in the St Louis metro area after the passage of the inverted surface trough. MVFR cigs should rise into the VFR catagory by late tonight. Specifics for KSTL: Light rain will move eastward into STL early this morning, then shift east of STL during the early afternoon. The cloud ceiling will lower in the MVFR catagory by late morning. The ely surface wind will become sely later this morning, then back around to a n-nwly direction by late afternoon. The MVFR cigs should rise into the VFR catagory late tonight. The surface wind will become light Friday morning as a surface ridge axis moves over STL. GKS && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1131 PM CST WED MAR 2 2016 .UPDATE: Issued at 920 PM CST Wed Mar 2 2016 Currently, the main upper level energy associated with the system for later tonight and Thursday is over the northern High Plains, near the interface between Wyoming and western South Dakota. There is persistent WAA over our region now in advance of the system, most focused in an axis from central IA to northwest MO, but it is still taking some time to saturate the lower layers before pcpn can initiate. A few stray sprinkles are not out of the question for the remainder of this evening. The main energy is expected to dig into western AR Thursday morning, while driving a lead disturbance thru northern AR into TN. These two main drivers now appear to take much of the best WAA and broadscale lift south with them. While this does work over our region, it will only do so briefly and then collapses to the south. This has been picked up by the HRRR and RAP, which significantly reduce the QPF over our region to near zero in many areas. But one thing the HRRR and RAP are missing out on is that there is currently strong WAA over the interface of NE/KS/MO and this is producing rain, although the coverage on radar is worse than what is actually hitting the ground. What all of this appears to be saying is that the energy needed to saturate the column sufficiently to achieve rain is going to be close to what will actually happen and we are being given large divergences on forecast rainfall amounts, depending on whether that threshold is met or not. It all seemed much more achievable a model run ago. As it stands now, the best chances for rainfall look to be northeast MO, as the pcpn enters from the west with weakening lift, and southeast MO which will gain benefit of the more southerly digging main system. Will only make minor changes to the forecast at this stage, trimming slightly but maintaining the high PoPs in spots (only 0.01" needed), but backing off on QPF amounts. Lots of low clouds still expected Thursday, and cool temps seem to be the way to go with this setup and winds turning from east to north. TES && .SHORT TERM: (Through Thursday) Issued at 243 PM CST Wed Mar 2 2016 Hybrid clipper will begin to impact the CWA overnight tonight and continue into the day on Thursday. System has pushed slightly to the southwest compared to 24 hours ago. Main impacts for this southwestward adjustment include increasing PoPs into the categorical category as well as cooling high temperatures on Thursday. Expect strong warm/moist advection in conjunction with increasing upper-level forcing for ascent to develop widespread light rain late this evening near the MO/IA border. This are of rain should expand southward due to a strengthening nocturnal LLJ but also advect to the south and east as well. Precipitation for our CWA...even with a slight adjustment of the system track to the south and west...still appears to be all liquid rain due to temperatures above freezing at lower levels. As alluded to above...had to cool high temperatures for a majority of the CWA on Thursday several degrees. Surface low on Thursday now looks to track southwest of a KIRK>>KSTL>>KSLO line which will put at least the northeastern 1/2 of the CWA in the cold sector of the cyclone. A chilly...raw early March day looks on tap for most with light rain...low clouds...and highs in the 40s. By afternoon...rain should push off to the south and east of the CWA. Gosselin .LONG TERM: (Thursday through Next Wednesday) Issued at 243 PM CST Wed Mar 2 2016 Mostly quiet weather with moderating temperatures back above normal by this upcoming weekend still looks in store. Very unsettled weather should take hold early next week with potentially multiple rounds of showers and thunderstorms. Best bet of this activity for now appears to be in the Tuesday/Tuesday night timeframe. Though still many days away...the pattern next week looks quite ominous with meridional flow throughout the troposphere. This would in turn supply much of the lower and mid-Mississippi Valley with tons of Gulf moisture. If the baroclinic zone does not progress much southeastward through the week...there will be more than enough rain to cause problems across the region as round after round of showers w/ possible embedded convection could affect many of the same areas. Gosselin && .AVIATION: (For the 06z TAFs through 06z Thursday Night) Issued at 1131 PM CST Wed Mar 2 2016 Flight category conditions are expected to transition from VFR at all sites currently to at least MVFR by late tonight into early Thursday morning with some IFR possible. As it stands now, the best chances for IFR remain in UIN and have kept the mention in the 06z TAF. Elsewhere, it looks like the trend to delay the rain a bit and have it struggle advecting eastward into the STL metro area will probably also cause a delay with the MVFR CIGs moving in, and as a result, have delayed in STL metro until mid to late morning. But once these CIGs move in, they should stay for much, if not all, the remainder of the valid TAF period. Some clearing expected late Thursday night, but beyond the valid period for most TAFs. Otherwise, look for easterly winds to shift northerly during the day on Thursday, either late morning or early afternoon at the TAF sites as an inverted TROF works thru. TES && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
924 AM MST THU MAR 3 2016 .UPDATE... THE FOG IS DISSIPATING AROUND BAKER...BUT VISIBILITY IS STILL AROUND 2 MILES...SO EXTENDED THE MENTION OF FOG FOR ANOTHER HOUR. OTHERWISE TWEAKED TEMPS AND HUMIDITY BASED ON CURRENT TRENDS. REST OF THE FORECAST LOOK GOOD. REIMER && .SHORT TERM...VALID FOR TDY AND FRI... THE MAIN THEME FOR THE NEXT COUPLE OF DAYS IS FOR MILD WEATHER TO TAKE HOLD THROUGH THE END OF THE WEEK. HIGH TEMPERATURES WILL REACH IN THE 60S TO END THE WEEK...AND AS YOU WILL SEE IN THE EXTENDED FORECAST...EVEN A 70 DEGREE HIGH IS POSSIBLE SATURDAY. THE BEST CHANCE OF PRECIPITATION WILL COME TONIGHT WITH THE PASSAGE OF A WEAK SHORTWAVE. A QUIETER DAY IS IN STORE TODAY AS FLAT RIDGING TAKES OVER. MID LEVEL FLOW BACKS AND DOWNSLOPE WARMING IN RESPONSE HAS 850MB TEMPERATURES RISING TO AROUND 12C. THIS WOULD TRANSLATE TO HIGH TEMPERATURES IN THE UPPER 50S TO LOWER 60S. A LEE SURFACE TROUGH WAS FORMING THIS MORNING AND THIS HAS CAUSED WINDS TO GUST TO AROUND 45 MPH AT LIVINGSTON. GRADIENT WILL CONTINUE THIS MORNING THEN TURN MORE WESTERLY THIS AFTERNOON. BUMPED WINDS UP FOR LIVINGSTON BUT KEPT THEM BELOW ADVISORY CRITERIA. THE REST OF THE AREA WILL BE A LITTLE BREEZY BUT WINDS WILL BE MUCH LIGHTER COMPARED TO YESTERDAY. FOG HAS FORMED IN BAKER THIS MORNING WITH VISIBILITY DROPPING BELOW A MILE. EVENING CREW ADDED FOR THIS MORNING AND WILL LEAVE IN. HRRR LIFTS FOG OUT BY LATE MORNING SO DID MAKE THAT ADJUSTMENT. SHORTWAVE ENERGY WILL CRASH THE RIDGE TONIGHT AND THIS WILL SPREAD MID LEVEL MOISTURE AND ASCENT IN THIS EVENING. AS THE WAVE DROPS SOUTHEAST TOWARD THE CENTRAL PLAINS...ASCENT WILL BE DRIVEN INTO THE SOUTHERN SECTIONS OVERNIGHT. RAISED POPS TO SCATTERED AS A DECENT SLUG OF MOISTURE AND SOME INSTABILITY WERE AVAILABLE. THE SHORTWAVE WAS WEAKER THAN THE LAST FEW THAT HAVE COME THROUGH AND WILL BE WORKING AGAINST DOWNSLOPE FLOW...SO WILL KEEP THE HIGHER POPS IN THE MOUNTAINS. THE SHORTWAVE EXISTS INTO THE PLAINS FRIDAY NIGHT AND IS REPLACED BY A RIDGE. FRIDAY SHOULD BE MILD AGAIN DESPITE LINGERING CLOUDS EARLY IN THE DAY. CLOUDS WILL CLEAR OUT BY AFTERNOON AND THIS WILL ALLOW THE RIDGE AXIS TO PRODUCE LOWER 60S MOST LOCATIONS. TWH .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... MADE A FEW CHANGES TO THE EXTENDED FORECAST PERIOD THIS MORNING...CONCENTRATED ON RAISING WEEKEND TEMPS AND TWEAKING OF POPS ASSOCIATED WITH WAVES CROSSING THE REGION THROUGH THE PERIOD. OVERALL...THE STORY FOR THE EXTENDED PERIOD REMAINS THE SAME HOWEVER...WITH AN UPPER LEVEL RIDGE DOMINATING THE PATTERN. TEMPERATURES SHOULD BE WELL ABOVE NORMAL THROUGH THE WEEKEND...AND RAISED HIGHS FOR SATURDAY AND SUNDAY...EVEN THOUGH THE APPEARS TO FLATTEN...GIVING WAY TO A LONG WAVE PACIFIC TROUGH MOVING IN FROM THE PACIFIC COAST. THIS CHANGE MARKS THE BEGINNING OF A STRETCH OF POTENTIALLY UNSETTLED WEATHER WITH SEVERAL SHORTWAVES TRANSITIONING THROUGH THE FLOW. IT WILL ALSO MARK THE START OF STRETCH OF COOLER TEMPERATURES...WITH MID 50S MOST OF NEXT WEEK. THE BEST CHANCE FOR ANY WIDESPREAD PRECIPITATION WILL COME SUNDAY EVENING INTO MONDAY AS A DISTURBANCE CROSSES THER REGION. WEAKER SHORTWAVES WILL SLIDE THROUGH THE REGION THROUGH THE REMAINDER OF THE THE WORK WEEK...WITH MAINLY MOUNTAIN POPS...BUT SLIGHTS CHANCES INTO THE PLAINS AS WELL. GILSTAD && .AVIATION... MAINLY VFR CONDITIONS TODAY. A DISTURBANCE CROSSING THE REGION WILL BRING ISOLATED TO SCATTERED SHOWERS ACROSS THE REGION THIS EVENING...WITH LOCALIZED MVFR CONDITIONS POSSIBLE IN SHOWERS. BEST POTENTIAL FOR PRECIP WILL BE IN BEARTOOTH/ABSAROKAS MOUNTAINS...WITH INCREASING OBSCURATIONS THROUGH THE DAY...THEN PERSISTENT OBSCURATIONS THROUGH THE NIGHT...IN SNOW. GILSTAD/CHAMBERS && .PRELIMINARY POINT TEMP/POPS... TDY FRI SAT SUN MON TUE WED ------------------------------------------------------- BIL 060 036/062 038/070 039/067 038/056 032/052 031/056 0/B 30/U 00/U 01/U 42/W 11/B 22/W LVM 059 034/057 036/066 040/061 033/051 029/050 031/052 2/W 41/U 01/N 12/W 42/W 12/W 22/W HDN 061 032/062 031/071 034/069 035/059 028/054 028/058 0/B 30/U 00/U 01/U 42/W 11/B 22/W MLS 059 034/060 031/070 034/069 036/057 029/053 028/055 0/B 30/U 00/U 00/U 33/W 21/B 21/B 4BQ 059 033/059 031/070 034/070 035/056 027/052 028/057 0/B 30/U 00/U 00/U 33/W 21/B 21/B BHK 053 031/054 028/068 032/069 034/054 027/048 026/052 0/B 30/U 00/U 00/U 23/W 21/B 21/B SHR 059 030/057 028/068 033/066 034/053 026/051 025/056 0/B 31/B 00/U 00/U 43/W 22/W 21/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
340 AM MST THU MAR 3 2016 .SHORT TERM...VALID FOR TDY AND FRI... THE MAIN THEME FOR THE NEXT COUPLE OF DAYS IS FOR MILD WEATHER TO TAKE HOLD THROUGH THE END OF THE WEEK. HIGH TEMPERATURES WILL REACH IN THE 60S TO END THE WEEK...AND AS YOU WILL SEE IN THE EXTENDED FORECAST...EVEN A 70 DEGREE HIGH IS POSSIBLE SATURDAY. THE BEST CHANCE OF PRECIPITATION WILL COME TONIGHT WITH THE PASSAGE OF A WEAK SHORTWAVE. A QUIETER DAY IS IN STORE TODAY AS FLAT RIDGING TAKES OVER. MID LEVEL FLOW BACKS AND DOWNSLOPE WARMING IN RESPONSE HAS 850MB TEMPERATURES RISING TO AROUND 12C. THIS WOULD TRANSLATE TO HIGH TEMPERATURES IN THE UPPER 50S TO LOWER 60S. A LEE SURFACE TROUGH WAS FORMING THIS MORNING AND THIS HAS CAUSED WINDS TO GUST TO AROUND 45 MPH AT LIVINGSTON. GRADIENT WILL CONTINUE THIS MORNING THEN TURN MORE WESTERLY THIS AFTERNOON. BUMPED WINDS UP FOR LIVINGSTON BUT KEPT THEM BELOW ADVISORY CRITERIA. THE REST OF THE AREA WILL BE A LITTLE BREEZY BUT WINDS WILL BE MUCH LIGHTER COMPARED TO YESTERDAY. FOG HAS FORMED IN BAKER THIS MORNING WITH VISIBILITY DROPPING BELOW A MILE. EVENING CREW ADDED FOR THIS MORNING AND WILL LEAVE IN. HRRR LIFTS FOG OUT BY LATE MORNING SO DID MAKE THAT ADJUSTMENT. SHORTWAVE ENERGY WILL CRASH THE RIDGE TONIGHT AND THIS WILL SPREAD MID LEVEL MOISTURE AND ASCENT IN THIS EVENING. AS THE WAVE DROPS SOUTHEAST TOWARD THE CENTRAL PLAINS...ASCENT WILL BE DRIVEN INTO THE SOUTHERN SECTIONS OVERNIGHT. RAISED POPS TO SCATTERED AS A DECENT SLUG OF MOISTURE AND SOME INSTABILITY WERE AVAILABLE. THE SHORTWAVE WAS WEAKER THAN THE LAST FEW THAT HAVE COME THROUGH AND WILL BE WORKING AGAINST DOWNSLOPE FLOW...SO WILL KEEP THE HIGHER POPS IN THE MOUNTAINS. THE SHORTWAVE EXISTS INTO THE PLAINS FRIDAY NIGHT AND IS REPLACED BY A RIDGE. FRIDAY SHOULD BE MILD AGAIN DESPITE LINGERING CLOUDS EARLY IN THE DAY. CLOUDS WILL CLEAR OUT BY AFTERNOON AND THIS WILL ALLOW THE RIDGE AXIS TO PRODUCE LOWER 60S MOST LOCATIONS. TWH .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... MADE A FEW CHANGES TO THE EXTENDED FORECAST PERIOD THIS MORNING...CONCENTRATED ON RAISING WEEKEND TEMPS AND TWEAKING OF POPS ASSOCIATED WITH WAVES CROSSING THE REGION THROUGH THE PERIOD. OVERALL...THE STORY FOR THE EXTENDED PERIOD REMAINS THE SAME HOWEVER...WITH AN UPPER LEVEL RIDGE DOMINATING THE PATTERN. TEMPERATURES SHOULD BE WELL ABOVE NORMAL THROUGH THE WEEKEND...AND RAISED HIGHS FOR SATURDAY AND SUNDAY...EVEN THOUGH THE APPEARS TO FLATTEN...GIVING WAY TO A LONG WAVE PACIFIC TROUGH MOVING IN FROM THE PACIFIC COAST. THIS CHANGE MARKS THE BEGINNING OF A STRETCH OF POTENTIALLY UNSETTLED WEATHER WITH SEVERAL SHORTWAVES TRANSITIONING THROUGH THE FLOW. IT WILL ALSO MARK THE START OF STRETCH OF COOLER TEMPERATURES...WITH MID 50S MOST OF NEXT WEEK. THE BEST CHANCE FOR ANY WIDESPREAD PRECIPITATION WILL COME SUNDAY EVENING INTO MONDAY AS A DISTURBANCE CROSSES THER REGION. WEAKER SHORTWAVES WILL SLIDE THROUGH THE REGION THROUGH THE REMAINDER OF THE THE WORK WEEK...WITH MAINLY MOUNTAIN POPS...BUT SLIGHTS CHANCES INTO THE PLAINS AS WELL. GILSTAD && .AVIATION... MAINLY VFR CONDITIONS TODAY...WITH SOME PATCHY FOG POSSIBLE AROUND KMLS AND KBHK THROUGH MID MORNING. A DISTURBANCE CROSSING THE REGION WILL BRING ISOLATED TO SCATTERED SHOWERS ACROSS THE REGION THIS EVENING...WITH LOCALIZED MVFR CONDITIONS POSSIBLE IN SHOWERS. BEST POTENTIAL FOR PRECIP WILL BE IN BEARTOOTH/ABSAROKAS MOUNTAINS...WITH INCREASING OBSCURATIONS THROUGH THE DAY...THEN PERSISTENT OBSCURATIONS THROUGH THE NIGHT...IN SNOW. GILSTAD && .PRELIMINARY POINT TEMP/POPS... TDY FRI SAT SUN MON TUE WED ------------------------------------------------------- BIL 060 036/062 038/070 039/067 038/056 032/052 031/056 0/B 30/U 00/U 01/U 42/W 11/B 22/W LVM 060 034/057 036/066 040/061 033/051 029/050 031/052 2/W 41/U 01/N 12/W 42/W 12/W 22/W HDN 061 032/062 031/071 034/069 035/059 028/054 028/058 0/B 30/U 00/U 01/U 42/W 11/B 22/W MLS 059 034/060 031/070 034/069 036/057 029/053 028/055 0/B 30/U 00/U 00/U 33/W 21/B 21/B 4BQ 060 033/059 031/070 034/070 035/056 027/052 028/057 0/B 30/U 00/U 00/U 33/W 21/B 21/B BHK 053 031/054 028/068 032/069 034/054 027/048 026/052 0/B 30/U 00/U 00/U 23/W 21/B 21/B SHR 059 030/057 028/068 033/066 034/053 026/051 025/056 0/B 31/B 00/U 00/U 43/W 22/W 21/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
526 AM CST THU MAR 3 2016 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 315 AM CST THU MAR 3 2016 FORECAST CONCERNS THROUGH THE SHORT TERM WILL MAINLY BE TEMPERATURES AND CLOUDS. THE OAX 00Z SOUNDING WAS MOIST ABOVE H6 WITH A PWAT OF 0.49 INCHES. THE H3 130 JET STRETCHED FROM MONTANA TO WYOMING AND COLORADO. THERE WERE 60-80M HEIGHT FALLS OVER COLORADO AND WESTERN KANSAS WITH EMBEDDED SHORTWAVES IN THE NORTHWEST FLOW ALOFT. CLUSTERS OF STORMS WERE BETTER ORGANIZED OVER WESTERN NEBRASKA...NORTHERN KANSAS AND SOUTH INTO OKLAHOMA WITH RAIN AND SPOTTY SHOWERS FOR THE LOCAL AREA. AT 09Z...THE LATEST SURFACE ANALYSIS HAD AN ELONGATED AREA OF SURFACE LOW PRESSURE FROM NORTHERN TEXAS INTO EASTERN KANSAS...WITH AND INVERTED TROF FEATURE BACK TOWARD ONEILL AND INTO SOUTH DAKOTA. TEMPERATURES WERE IN THE 20S AND 30S WITH NORTH WINDS MAINLY 5 TO 10 MPH. AT 0930Z...A BAND RAIN/FREEZING RAIN/RAIN SNOW MIX EXTENDED FROM PRAGUE TO SEWARD TO FRIEND. SEWARD COUNTY SAID IT WAS ALL RAIN THERE. TODAY...THE SHORTWAVE TROUGH OVER THE REGION WILL SOUTHEAST THROUGH MISSOURI AND INTO KENTUCKY/TENNESSEE/GULF STATES. NORTHWEST FLOW AND COLD AIR ADVECTION WILL CONTINUE. ANY LINGERING SPRINKLES OR ISOLATED RAIN/MIX SHOULD BE ON THE WANE EARLY THIS MORNING. THERE IS QUITE A BIT OF STRATUS TO THE NORTH AND THE NORTH FLOW WOULD ADVECT THESE LOW AND MID CLOUDS SOUTHWARD THROUGH THE DAY. THE CLOUDS SHOULD HANG AROUND THE LONGEST IN NORTHEAST NEBRASKA AND WESTERN IOWA...WITH FEWER CLOUDS TOWARD FAIRBURY. HIGHS ARE FORECAST TO TOP OUT IN THE 30S AND 40S. STRONGER WINDS ALOFT WILL KEEP WINDS UP IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA...HOWEVER SURFACE WINDS WILL BECOME LIGHT AND VARIABLE BY EVENING AS SURFACE HIGH PRESSURE BUILDS IN. THE OPERATIONAL MODELS ARE IN GOOD AGREEMENT THAT RIDGING WILL BUILD INTO THE PLAINS TONIGHT. WARM AIR ADVECTION ENSUES AHEAD OF THE NEXT SHORTWAVE TROUGH THAT PASSES THROUGH THE NORTHERN PLAINS AND PARTS OF THE MISSOURI RIVER VALLEY FRIDAY. A LOW LEVEL JET STRENGTHENS TO 40 KNOTS WITH BREEZY CONDITIONS AT THE SURFACE. WARMER TEMPERATURES WITH HIGHS IN THE 50S AND 60S FOR FRIDAY WITH INCREASING SOUTH WINDS TO 15 TO 30 MPH. THERE COULD BE SOME SPRINKLES WITH THE WARM AIR ADVECTION FRIDAY...HOWEVER...THE ORGANIZED PRECIPITATION SHOULD BE NORTH OF THE FORECAST AREA. THE MID TROPOSPHERIC RIDGE AMPLIFIES OVER THE ROCKIES FRIDAY NIGHT AND THE PLAINS SATURDAY. THIS ALLOWS SOME COOLING AIR TO WORK IN...HOWEVER HIGHS ARE STILL FORECAST TO BE IN THE 50S. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 315 AM CST THU MAR 3 2016 MORE OF A SPRINGTIME PATTERN WITH STRONGER WINDS...WARMER TEMPERATURES AND SCATTERED SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK. AN IMPULSE MOVING ACROSS THE ROCKIES SATURDAY NIGHT BEGINS TO BREAK DOWN THE RIDGE AND THIS CONTINUES SUNDAY. THE FLOW ALOFT IS FROM THE SOUTHWEST AND AN ADDITIONAL SHORTWAVE TROF SWINGS THROUGH THE ROCKIES AND WESTERN PLAINS MONDAY AND MONDAY NIGHT. MEANWHILE...MONDAY THROUGH TUESDAY...CLOSED LOW PRESSURE OVER CALIFORNIA TRACKS INTO MEXICO...WITH THE TROUGH ELONGATING NORTHEASTWARD INTO THE PLAINS. A STRENGTHENING LOW LEVEL JET TO AROUND 40KTS WILL TRANSPORT MOISTURE NORTHWARD (6 TO 10DEG C DEWPOINT) WITH THE CHANCE FOR A FEW SHOWERS OR THUNDERSTORMS IN SOUTHEAST NEBRASKA SUNDAY AFTERNOON. HIGHS IN 50S AND 60S RETURN FOR SUNDAY. THE CHANCE FOR THUNDERSTORMS CONTINUES SUNDAY NIGHT AND MONDAY AS THE SHORTWAVE TROUGH OVER THE ROCKIES LIFT NORTHEAST INTO WESTERN NEBRASKA...AND ALSO MONDAY NIGHT AS THE SURFACE FRONT PUSHES ACROSS THE FORECAST AREA. SURFACE WINDS LOOK STRONG MONDAY AND MONDAY NIGHT AND A WIND ADVISORY MAY BE NEEDED. SOME POST-FRONTAL PRECIPITATION COULD LINGER IN FAR SOUTHEAST NEBRASKA TUESDAY NIGHT...HOWEVER LOOKS TO BE EAST OF THE AREA WEDNESDAY. HIGHS MONDAY SHOULD RISE INTO THE 60S AND 70S. NOT AS WARM TUESDAY WITH HIGHS IN THE 50S AND 60S...AND 50S FOR WEDNESDAY. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 525 AM CST THU MAR 3 2016 ALL THREE TAF SITES HAD VFR CONDITIONS AS OF 11Z...BUT THIS WILL LIKELY CHANGE. LOW LEVEL MOISTURE EXTENDED FROM NORTHWEST TO EAST OF THE AREA...AND IT SHOULD MOVE SOUTHWARD. THE LOW CIGS IN IOWA MAY BACK TO THE SOUTHWEST TOWARD OMAHA THIS MORNING...THEN LOOK FOR MVFR CIGS AT ALL THREE SITES MUCH OF THE DAY. RECENT RAP MODEL SOUNDINGS AND RH TIME SECTIONS SUGGEST LOW CLOUDS MAY LINGER WELL INTO THE EVENING...BUT FOR NOW...DECIDED TO TREND TOWARD VFR BY LATE AFTN OR EARLY EVENING. SOME FOG MAY DEVELOP OVERNIGHT...BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE AT THIS TIME. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS ELKO NV
207 AM PST THU MAR 3 2016 .SYNOPSIS...PATTERN IS BEGINNING TO TRANSITION TO A WET AND COOLER ONE WITH A COUPLE OF WEAK SYSTEMS BRINGING CLOUDS AND SHOWERS THROUGH SATURDAY. A STRONGER AND COLDER SYSTEM IS ON TAP FOR SUNDAY...FOLLOWED BY SEVERAL MORE NEXT WEEK. && .SHORT TERM...THIS MORNING THROUGH SATURDAY. PATTERN BEGINNING TO BECOME ACTIVE WITH A FRONTAL BOUNDARY ENTERING THE CWA TODAY...FOLLOWED ANOTHER ONE EARLY SATURDAY. OVERALL STILL ABOVE AVERAGE TEMPERATURES AS THE UPPER LEVEL FLOW REMAINS OUT OF THE SOUTHWEST. SPECIFICALLY..A COLD FRONT IS PROGRESSING EASTWARD WITH THE MAIN PRECIP BAND JUST CROSSING INTO NV. 700-600MB FGEN NUMBERS ALONG WITH METSAT INDICATES THAT THIS BAND WILL WEAKEN AS IT ENTERS HUMBOLDT COUNTY EARLY THIS MORNING...BUT PROVIDE ENOUGH LIFT TO GENERATE SHOWERS OVER MAINLY THE HIGHER TERRAIN. BY LATER THIS MORNING ANOTHER WAVE WILL TRAVEL NORTHEAST ALONG THE FRONTAL BOUNDARY...REDEVELOPING A FRONTAL BAND OF PRECIP OVER EASTERN HUMBOLDT COUNTY AND NORTHWESTERN HALF OF ELKO COUNTY BY EARLY THIS AFTERNOON. GFS...RAP...AND HRRR ALL PEG THIS NARROW BAND SO BASICALLY WENT A BLEND FOR PLACEMENT BUT LIMITED THE POP AND QPF BELOW THEIR MEANS AS THIS BAND MAY NOT DEVELOP AS STRONG AS THEY INDICATE. ALSO...CANNOT RULE OUT A LIGHTNING STRIKE OR TWO...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IT IN THE FORECAST AT THIS TIME. SOME HIGHER TERRAIN AREAS COULD PICK A QUICK .10 OF PRECIP DURING THIS BRIEF PERIOD. SNOW LEVELS WILL RUNS WELL ABOVE THE VALLEYS FLOOR SO NO IMPACTS EXPECTED. THIS BAND WILL WEAKEN QUITE QUICKLY AS IT SHIFTS MAINLY EASTWARD...SPREADING THE BEST PRECIP CHANCES OVER NORTHEASTERN NV...STRETCHING SOUTHWESTWARD TOWARDS BATTLE MTN. AMOUNTS ARE NOT EXPECTED TO BE MORE THAN A COUPLE OF HUNDREDTHS WITH THE EXCEPTION OF NORTHEASTERN ELKO COUNTY WHERE MORE COULD FALL IN THE HIGHER TERRAIN. BY TONIGHT THIS BOUNDARY PRETTY MUCH STALLS OUT JUST SOUTH I-80 AND LOOKS TO WEAKEN...BUT DOES PROVIDE SOME LOW LEVEL CONVERGENCES TO GENERATE VERY ISOLATED SHOWERS NEAR AND TO THE NORTH OF IT OVERNIGHT INTO EARLY FRIDAY MORNING. ONCE AGAIN..PRECIP AMOUNTS WILL BE VERY LIGHT. SOME SHORT RANGE MODELS INDICATE ANOTHER WAVE MAY TRAVEL NORTHEAST ALONG THE BOUNDARY...STRENGTHENING IT AND FORMING A BAND OF PRECIP. CLOUD COVER DECREASES TOMORROW AS A SHORTWAVE RIDGE QUICKLY BUILDS OVERHEAD IN ADVANCE OF THE NEXT FRONTAL SYSTEM HITTING THE CA COAST LATE FRIDAY. THIS BOUNDARY WILL ONCE AGAIN WEAKEN AS IT LIFTS NORTHEAST IN WESTERN NV LATE FRIDAY NIGHT. THIS WILL SPREAD PRECIP IN HUMBOLDT COUNTY SATURDAY MORNING...SHIFTING EASTWARD SATURDAY AFTERNOON. POPS AND PRECIP AMOUNTS WILL QUICKLY DROP TO OFF EAST AND SOUTH OF HUMBOLDT COUNTY AS BOUNDARY FALLS APART. ONCE AGAIN SNOW LEVELS WILL RUN ABOVE 7500FT OR HIGHER SO NO TRAVEL IMPACTS EXPECTED. SOUTHERLY WINDS WILL PICK UP SATURDAY AHEAD OF THIS BOUNDARY BUT ALSO FROM THE OVERALL INCREASE IN SOUTHWESTERLY WINDS ALOFT AHEAD OF A MUCH STRONGER FRONTAL SYSTEM WITH A WELL DEFINE ATMOSPHERE RIVER THAT SPREADS HEAVY PRECIP INTO NORTHERN CALIFORNIA SATURDAY AFTERNOON. WILL HAVE TO KEEP AN EYE ON THE WINDS FOR LIKELY HEADLINES IN HUMBOLDT COUNTY FOR SATURDAY AFTERNOON OR EVENING. AS FOR TEMPS...WITH ABUNDANCE OF CLOUD COVER IN NORTHERN NV TODAY...TEMPS WILL NOT CLIMB AS MUCH AS YESTERDAY...STILL 50S AND 60S WILL DOMINANT. TEMPS SHOULD DROP OFF OFF TONIGHT TO MAINLY THE 30S BEFORE CLIMBING BACK IN THE 50S AND 60S TOMORROW UNDER PARTLY CLOUDY SKIES. WITH THE APPROACHING FRONTAL BOUNDARY TOMORROW WESTERN AREAS WILL REMAIN WELL IN THE 30S TOMORROW NIGHT...WHILE EASTERN NV FALLS BACK INTO THE 20S AND 30S. WITH INCREASE IN SOUTHERLY OR SOUTHWESTERLY FLOW...TEMPS SHOULD EASILY CLIMB BACK INTO THE 50S AND 60S ON SATURDAY. .LONG TERM...SATURDAY NIGHT THROUGH NEXT WEDNESDAY. A MOIST LOW PRESSURE SYSTEM WILL BRING AN EXTENDED PERIOD OF UNSETTLED WEATHER...AND A DEFINITE CHANGE FROM RECENT MILD WEATHER. THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE TIMING OF A COLD FRONT ON SUNDAY. SATURDAY NIGHT. HIGH PRESSURE WILL BROADEN TO ENCOMPASS THE ENTIRE CENTRAL CONUS...BUT WILL YIELD TO A STRONG INCOMING TROUGH OF LOW PRESSURE. A LOW PRESSURE SYSTEM WILL BE DROPPING DOWN FROM ALASKA AND PUSHING A COPIOUS AMOUNT OF MOISTURE INTO CALIFORNIA AND WESTERN NEVADA. NEVADA WILL BE UNDER A DIFFLUENT FLOW ALOFT. WITH THE PERSISTENT MOISTENING FLOW ALOFT...SHOWERS SHOULD SPREAD TO MOST AREAS BY SUNRISE SUNDAY HOWEVER THERE IS SOME QUESTION AS TO HOW MUCH RAIN WILL REACH THE VALLEYS EAST OF HUMBOLDT COUNTY DUE TO THE PURE SOUTHWEST FLOW ACROSS THE SIERRAS. SNOW LEVEL WILL BE DROPPING TO AROUND 7500 FEET. EARLY MORNING LOWS WILL BE RELATIVELY MILD...ABOVE FREEZING ALL AROUND. SUNDAY. AN UPPER LOW CIRCULATION WILL TAKE OFF TO THE NORTH...SKIRTING THE OREGON AND WASHINGTON COASTLINE...AND SPINNING OFF A STRONG SHORTWAVE THAT WILL BLAST THROUGH NEVADA. A COLD FRONT WILL BRING RAIN THAT WILL QUICKLY TURN TO SNOW IN THE VALLEYS. SNOW LEVELS WILL START OUT AROUND 6500 FEET. ISOLATED THUNDERSTORMS WILL BE POSSIBLE AND WIND GUSTS ON THE HIGHEST MOUNTAIN PEAKS MAY REACH 70 MPH AHEAD OF THE COLD FRONT. THE LATEST MODEL TIMING LOOKS LIKE THIS...THE FRONT SHOULD MOVE THROUGH WINNEMUCCA ABOUT 4 AM...FOLLOWED BY ELKO ABOUT 8 AM...THEN ELY ABOUT 10 AM. AT THIS JUNCTURE...SNOWFALL ESTIMATES ARE FIGURED TO BE HIGHER IN CENTRAL NEVADA...AS MUCH AS ONE FOOT ON THE MOUNTAINS GENERALLY 2-4 INCHES IN THE VALLEYS. IT IS POSSIBLE THAT AS MUCH AS 6 INCHES COULD FALL IN THE VALLEYS OF WHITE PINE COUNTY. TEMPERATURES MAY START OUT IN THE 40S EARLY IN THE DAY THEN FALL THROUGH THE 30S. SUNDAY NIGHT THROUGH TUESDAY. SNOW SHOWERS WILL CONTINUE. THERE MAY BE A SECONDARY COLD FRONT MOVING THROUGH ON MONDAY. HIGHS IN THE 30S TO AROUND 40. LOWS IN THE TEENS AND 20S. TUESDAY NIGHT THROUGH WEDNESDAY. AT THIS JUNCTURE...IT APPEARS THAT A SHORTWAVE RIDGE WILL BRING DRIER CONDITIONS HOWEVER A FEW SHOWERS MAY PERSIST ACROSS NORTHERN NEVADA. HIGHS IN THE 30S TO AROUND 40. LOWS IN THE TEENS AND 20S. && .AVIATION...VFR CONDITIONS ARE EXPECTED TO HOLD THROUGH FRIDAY MORNING. HOWEVER HIGH PRESSURE WILL BE MOVING EAST OF NEVADA THIS MORNING AND SHOWERS WILL BE DEVELOPING OVER THE NORTHERN PART OF THE STATE AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST. VCSH IS POSSIBLE AT KWMC THURSDAY AFTERNOON. && .LKN WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 85/92/85
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 PM EST THU MAR 3 2016 .SYNOPSIS... AN AREA OF LOW PRESSURE TRACKING EAST ACROSS THE GULF COAST STATES WILL QUICKLY NORTHEAST UP THE NC COAST OVERNIGHT AND OFF THE MID-ATLANTIC COAST ON FRIDAY. HIGH PRESSURE WILL BUILD INTO THE AREA FRIDAY NIGHT AND SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM THURSDAY... ...A LIGHT WINTRY MIX POSSIBLE ACROSS THE NORTHERN PIEDMONT TONIGHT... HIGH PRESSURE CURRENTLY CENTERED OVER THE DELMARVA IS SHIFTING OFFSHORE THIS AFTERNOON. WINDS WILL CONTINUE TO BECOME MORE EAST- SOUTHEASTERLY AND DEWPOINTS WILL RECOVER INTO THE UPPER 20S AND 30S. IT IS WORTH NOTING THAT DEWPOINTS ARE SLIGHTLY LOWER THAN FORECAST RIGHT NOW. MEANWHILE...A LOW AMPLITUDE SHORTWAVE AND ASSOCIATED SURFACE LOW TRACKING THROUGH THE MID-SOUTH WILL TRACK ACROSS AL/GA THIS EVENING AND TO THE NC COAST BY LATE TONIGHT. RAIN IS CURRENTLY MOVING INTO UPSTATE SC...THOUGH IT WILL INITIALLY GO TOWARD SATURATED THE DRY BOUNDARY LAYER AND SET UP A HYBRID CAD AIRMASS. LIFT REALLY STARTS TO STRENGTHEN AFTER 21Z AS THE WARM CONVEYOR BELT AND DEEPENING ISENTROPIC LIFT SHIFT OVERHEAD. THE HEAVIEST QPF WILL FOCUS ACROSS THE SOUTHERN PIEDMONT TO THE COASTAL PLAIN ALONG AND JUST NORTH OF THE SURFACE LOW...WITH ADDITIONAL LIGHTER PRECIP EXPECTED TO BREAK OUT OVER THE PIEDMONT AS A DEFORMATION BAND FORMS NORTHWEST OF THE PASSING LOW. LOW TEMPS TONIGHT WILL BE IN THE 32-39 RANGE. THE ONSET OF PRECIP MAY EVERY WELL COME IN FORM OF RAIN WITH SLEET OR PARTIALLY MELTED SNOW MIXED IN THIS EVENING...MAINLY ACROSS THE WESTERN PIEDMONT WHERE WET-BULB PROFILES ARE A BIT COOLER. AREAS SOUTH OF HIGHWAY 64 WILL BE MUCH TOO WARM BELOW 5000 FT FOR ANY NON- LIQUID PTYPES TONIGHT. CRITICAL THICKNESSES IN THE NORTHERN PIEDMONT (AND WITHIN THE DEFORMATION BAND ARE GENERALLY IN THE 1300-1310M (H10-H85) AND SUB-1540M (H85-H7)...WHICH SUPPORTS A MIX OF PTYPES. THE BIGGEST QUESTIONS THAT STILL REMAIN...AND LEAD US TO REFRAIN FROM A WINTER WX ADVISORY...ARE WHETHER OR NOT SNOW/SLEET WILL BE THE PREDOMINATE PTYPE FOR A DECENT DURATION. MODELS SHOW PRETTY RAPID DRYING ABOVE -10C AFTER 06Z...WHICH WILL SHUT OFF THE THE MIXING OF SNOW. ALSO...WETBULB TEMPS ARE PROGGED TO REMAIN ABOVE FREEZING THROUGH THE EVENT...SO SNOW SHOULD NOT READILY ACCUMULATE...EXCEPT MAYBE ON ELEVATED SURFACES. FINALLY...THE LATEST HRRR HAS SHIFTED THE NORTHWEST EDGE OF THE PRECIP SHIELD TO THE EAST...A TREND ALSO NOTED IN THE 12Z WRF-ARW. CONCERNS FOR ACCUMULATING SNOW ARE 1)MODELS UNDERDOING PRECIP RATES WHERE THERMAL PROFILES ARE MARGINAL AND 2) DRIER LOW-LEVEL AIR OVER EAST-CENTRAL VA COULD BE TAPPED THIS EVENING AS WINDS SWING BACK TO NORTH-NORTHEASTERLY IN RESPONSE TO THE SURFACE LOW ALONG THE COAST...CREATING LOWER WETBULB VALUES. WITH ALL OF THIS IN MIND...CONFIDENCE IN GREATER THAN 1 INCH OF SNOW AND/OR TRAVEL IMPACTS IS TOO LOW TO ISSUE AN ADVISORY. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM THURSDAY... PRECIP WILL BE EXITING THE COASTAL PLAIN FRIDAY MORNING ALONG WITH HE SURFACE LOW. SUBSIDENCE AND AND NORTHWESTERLY FLOW WILL CLEAR SKIES FROM WEST TO EAST...ALLOWING TEMPS INT HE WESTERN PIEDMONT TO CLIMB INTO THE 50S...WHILE AREAS EAST OF US 1 WILL HOLD ONTO CLOUDS A BIT LONGER AND MAY STAY IN THE MID/UPPER 40S. HIGH PRESSURE WILL BEGIN TO BUILD OVERHEAD FRIDAY NIGHT...WITH CLEARING SKIES...THOUGH SOME LINGERING MOISTURE UPSTREAM MAY RESULT IN PATCHY STRATO CU DRIFTING ACROSS THE PIEDMONT EARLY. OTHERWISE...GOOD RADIATIONAL POOLING CONDITIONS SHOULD RESULT IN LOWER 30S FOR LOWS. & .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 228 PM THURSDAY... THROUGH SAT NIGHT: HIGH PRESSURE WILL PASS OVERHEAD SAT...SHIFTING OFFSHORE SAT EVE/NIGHT. HIGHS GENERALLY IN THE MID 50S WITH WEAK WINDS BACKING TO SOUTHERLY BY SAT AFT/EVE. A SHORT WAVE ALOFT AND ASSOCIATED SURFACE LOW WILL DIVE SOUTHEAST FROM THE WESTERN GREAT LAKES INTO THE MID ATLANTIC SAT NIGHT. THE CHANCE FOR SOME LIGHT RAIN AS THE SHORTWAVE PASSES OVERHEAD CONTINUES TO INCREASE... HOWEVER AMOUNTS ARE EXPECTED TO BE FAIRLY LIGHT. LOWS SAT NIGHT IN THE MID 30S TO LOW 40S. SUN THROUGH THU: SURFACE HIGH PRESSURE WILL BUILD INTO AND OVER THE REGION THROUGH TUESDAY...SHIFTING OFFSHORE BUT CONTINUING TO RIDGE WESTWARD FROM THE ATLANTIC WED AND THU RESULTING IN A SOUTHERLY RETURN FLOW OVER CENTRAL NC. ANOTHER POTENT LOW PRESSURE SYSTEM APPROACHES FROM THE WEST MID-WEEK. AMPLIFYING THE RIDGE OVER THE SE U.S. AS IT DOES. THE RESULT WILL BE DEEPENING SOUTHERLY FLOW OVER CENTRAL NC AND INCREASING WINDS AT THE SURFACE. THERE WILL BE PLENTY OF SUNSHINE SUN AND MON...WITH GRADUALLY INCREASING HIGH CLOUDS THROUGH MID WEEK AHEAD OF THE AFOREMENTIONED SYSTEM. WITH THE INCREASING WARM ADVECTION...TEMPS WILL MODERATE FROM SUN (HIGHS IN THE MID 50S TO LOW 60S AND LOWS IN THE LOW TO MID 30S) THROUGH THU (HIGHS IN THE LOW TO MID 70S AND LOWS IN THE MID 50S). FOR NOW THE MODELS SUGGEST ANY PRECIPITATION WILL HOLD OFF UNTIL THU AFT/EVE OR LATER. WILL INTRODUCE A SLIGHT CHANCE OF SHOWERS ACROSS THE NORTH THU AFTERNOON. OTHERWISE...WILL KEEP THE FORECAST DRY. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 100 PM THURSDAY... HIGH PRESSURE CURRENTLY OVER THE DELMARVA WILL SHIFT OFFSHORE THIS AFTERNOON AND WINDS WILL BECOME MORE SOUTHEASTERLY AHEAD OF A LOW PRESSURE SYSTEM TRACKING INTO THE MID SOUTH. AS THE SYSTEM APPROACHES...MID-LEVEL CEILINGS WILL LOWER TO MVFR AND EVENTUALLY IFR AS RAIN OVERSPREADS THE AREA. KINT/KGSO/KFAY SHOULD SEE MVFR BY 00Z...AT KRDU/KRWI BY 03Z. IFR CONDITIONS WILL FOLLOW IN THE 03-07Z TIME FRAME. RAIN MAY BE BRIEFLY HEAVY AT KFAY...WHILE SNOW MAY MIX IN WITH THE RAIN AT KGSO/KINT. PRECIP WILL END FROM WEST TO EAST FRIDAY MORNING AS THE LOW PRESSURE MOVES TO NEAR THE OBX BY 12Z. NORTHERLY WINDS WILL STRENGTHEN TO 12- 15KT AT KRWI...WITH NORTHWESTERLY WINDS EVENTUALLY DEVELOPING ACROSS THE ENTIRE AREA AND GUSTING TO 15-18KT AS SKIES CLEAR. OUTLOOK: VFR CONDITIONS SHOULD DOMINATE THROUGH EARLY NEXT WEEK. THE EXCEPTION WILL BE SATURDAY NIGHT/EARLY SUNDAY MORNING WHEN A STRONG UPPER LEVEL DISTURBANCE WILL TRACK ACROSS THE REGION AND BRING A CHANCE OF SUB-VFR CONDITIONS AND LIGHT RAIN. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...22 LONG TERM...10 AVIATION...CBL/22
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1142 AM CST THU MAR 3 2016 .UPDATE... ISSUED AT 1136 AM CST THU MAR 3 2016 NO SIGNIFICANT CHANGE TO THE ONGOING FORECAST OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 17 UTC. EXPECT THE STRATUS TO HOLD ACROSS NORTH DAKOTA THROUGH THE REMAINDER OF THE DAY AND INTO THE NIGHT WITH LOW LEVEL WARM AIR ADVECTION REINFORCING THE LOW LEVEL INVERSION UNTIL GREATER MIXING SCOURS OUT THE LOW LEVEL MOISTURE BEHIND THE COLD FRONT TONIGHT INTO FRIDAY MORNING. UPDATE ISSUED AT 931 AM CST THU MAR 3 2016 CURRENT FORECAST IS ON TRACK AS PARTS OF THE NORTH CENTRAL CONTINUE TO SHOW LIGHT SNOW AND VISIBILITY IN DICKINSON HAS RISEN TO 5 MILES ALONG WITH VISIBILITIES AT ALL OTHER SITES ACROSS THE SOUTHWEST. UPDATE ISSUED AT 636 AM CST THU MAR 3 2016 WE ADDED ISOLATED FLURRIES TO THE FORECAST FROM CROSBY EASTWARD TO BOTTINEAU...ROLLA AND RUGBY THROUGH THE MORNING WITH THIS UPDATE. THAT CHANGE WAS PREDICATED BY WEAK RADAR ECHOES AROUND ROLLA WITH FLURRIES REPORTED AT ROLLA AND ESTEVAN...AND SUBTLE HINTS OF SAID ACTIVITY OVER NORTH CENTRAL ND WITH RECENT HRRR RUNS. THE REST OF THE FORECAST IS GENERALLY ON TRACK. FOG OVER SOUTHWESTERN ND HAS OCCASIONALLY BEEN REDUCING THE VISIBILITY TO 1/2SM AT DICKINSON. HOWEVER...SUB-1SM TYPE OF VISIBILITIES HAVE NOT BEEN WIDESPREAD. THAT IS LIKELY DUE TO A SHALLOW MIXED LAYER STILL PRESENT AT THE SURFACE PER MODEL FORECAST SOUNDINGS /AND CONFIRMED BY THE 12 UTC OBSERVED SOUNDING AT BISMARCK/. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CST THU MAR 3 2016 THE MAIN FOCUS FOR THE SHORT TERM IS FOG AND CLOUD COVER TODAY AND FREEZING RAIN POTENTIAL TONIGHT. A VERY MOIST BOUNDARY LAYER AND EASTERLY UPSLOPING WINDS WILL KEEP MOST OF NORTH DAKOTA SOCKED IN UNDER LOW STRATUS AND PATCHY FOG MOST OF THE DAY. WARM AIR ADVECTION AND SOUTHWESTERLY FLOW AT THE SURFACE WILL BEGIN LATE THIS AFTERNOON ACROSS SOUTHWEST NORTH DAKOTA AHEAD OF AN APPROACHING CLIPPER. THIS WILL BEGIN TO ERODE THE LOW STRATUS. TONIGHT...A CLIPPER WILL SWING THROUGH NORTH DAKOTA BRINGING A CHANCE FOR SOME LIGHT PRECIPITATION. MODELS ARE INDICATING A WARM LAYER AROUND 850MB BEING ADVECTED IN ALONG THE LEADING EDGE OF THE SURFACE LOW. THIS WARMER AIR SHOULD BE SUFFICIENT TO MELT ANY ICE CRYSTALS THAT FALL ALOFT. DUE TO THE TIMING OF THIS SYSTEM (DURING THE OVERNIGHT AND EARLY MORNING HOURS) SURFACE TEMPERATURES WILL BE BELOW FREEZING. THIS COULD LEAD TO SOME LIGHT FREEZING RAIN FOR PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. THERE IS SOME UNCERTAINTY AND DISPARITY BETWEEN THE MODELS ON EXACTLY HOW MUCH PRECIPITATION COULD FALL. SOME MODELS ARE ALMOST COMPLETELY DRY WITH THE PASSING OF THE LOW...WHILE OTHER MODELS BRING IN A FEW HUNDRETHS OF PRECIPITATION. ONLY A LITTLE BIT OF MOISTURE COULD CAUSE SOME SLICK CONDITIONS SO THIS SITUATION WILL BE CLOSELY MONITORED. AT THIS TIME WE DON`T FEEL CONFIDENT ENOUGH GIVEN THE UNCERTAINTY IN THE DIFFERENT MODEL SOLUTIONS TO ISSUE ANY HEADLINES OR HIGHLIGHT THIS THREAT ANY FURTHER THAN THE HAZARDOUS WEATHER OUTLOOK AND WEATHER STORY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 342 AM CST THU MAR 3 2016 A MILD AND WINDY FRIDAY WILL BE FOLLOWED BY A VERY WARM WEEKEND AND AN INCREASING CHANCE OF PRECIPITATION MONDAY AND TUESDAY. A SLIGHT CHANCE OF LIGHT FREEZING RAIN CONTINUES THROUGH 15 UTC FRIDAY MORNING OVER EAST CENTRAL ND...BUT WILL ABRUPTLY END AS ANY PRECIPITATION EXITS THE AREA AND SURFACE TEMPERATURES RISE ABOVE 32 F. A COLD FRONT WILL CROSS THE AREA FRIDAY MORNING AND LOW-LEVEL NORTHWEST FLOW WILL INCREASE IN ITS WAKE WITH THE GFS RUN FROM 00 UTC SIMULATING BOUNDARY LAYER WINDS AROUND 30 KT ON FRIDAY. PRESSURE RISES ARE NOT MUCH TO WRITE HOME ABOUT AT ONLY 2-3 MB/3 HOURS ON THE GFS /AND LESS ON THE 00 UTC NAM/ AND PEAK WINDS AT THE TOP OF THE WELL-MIXED LAYER FRIDAY AFTERNOON BASED ON FORECAST SOUNDINGS ARE GENERALLY UNDER 40 KT. THUS...WHILE A WINDY DAY IS EXPECTED...SPEEDS WILL LIKELY STAY UNDER ADVISORY CRITERIA IF TRENDS IN THE 00 UTC GUIDANCE SUITE ARE CORRECT. ON THE LARGE SCALE...HEIGHTS WILL BUILD ALOFT ACROSS THE REGION THIS WEEKEND DOWNSTREAM OF A POWERFUL PACIFIC JET THAT WILL DIG INTO THE WESTERN UNITED STATES...CARVING OUT A 500-MB TROUGH BY EARLY NEXT WEEK. GLOBAL MODEL GUIDANCE HAS BEEN STEADFAST IN ITS PREDICTION OF THESE KEY FEATURES THE LAST SEVERAL DAYS...RAISING OUR CONFIDENCE IN A VERY WARM WEEKEND BENEATH THE RIDGING ALOFT. IN FACT...WE WEIGHTED THE FORECAST A BIT TOWARD THE WARMER EDGE OF THE 00 UTC GUIDANCE GIVEN THE BREADTH OF EXPECTED WARM AIR ADVECTION AND MIXING...WITH WIDESPREAD 50S AND LOWER 60S F OVER MOST OF THE AREA ON SATURDAY...AND MANY 60S F LIKELY ON SUNDAY. IT WILL BE BREEZY...ESPECIALLY ON SATURDAY...PERHAPS ELEVATING THE RISK OF GRASS FIRES A BIT THIS WEEKEND TOO. BY MONDAY AND TUESDAY...A LEAD NORTHERN-STREAM SHORTWAVE TROUGH IS FORECAST TO EJECT INTO THE NORTHERN PLAINS OUT OF THE THEN- SPLITTING LONGWAVE TROUGH. HOWEVER...THE PREDICTABILITY OF ITS EVOLUTION IS LOW...SO FOR NOW WE ARE MERELY ADVERTISING CHANCE POPS AND A COOLING TREND IN THE MONDAY AND TUESDAY FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1136 AM CST THU MAR 3 2016 WIDESPREAD IFR/MVFR CEILINGS IN STRATUS WILL SLOWLY LIFT THROUGH THE AFTERNOON ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HOWEVER...STRATUS BUILD DOWN TO WIDESPREAD IFR IS EXPECTED AGAIN THIS EVENING AND TONIGHT. A COLD FRONT WILL MOVE ACROSS NORTH DAKOTA LATE TONIGHT INTO FRIDAY MORNING. NORTHWEST WIND GUSTS OF 25-30 KTS ARE EXPECTED BEHIND THE FRONT WITH IMPROVING CEILINGS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...AJ LONG TERM...CJS AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
938 AM CST THU MAR 3 2016 .UPDATE... ISSUED AT 931 AM CST THU MAR 3 2016 CURRENT FORECAST IS ON TRACK AS PARTS OF THE NORTH CENTRAL CONTINUE TO SHOW LIGHT SNOW AND VISIBILITY IN DICKINSON HAS RISEN TO 5 MILES ALONG WITH VISIBILITIES AT ALL OTHER SITES ACROSS THE SOUTHWEST. UPDATE ISSUED AT 636 AM CST THU MAR 3 2016 WE ADDED ISOLATED FLURRIES TO THE FORECAST FROM CROSBY EASTWARD TO BOTTINEAU...ROLLA AND RUGBY THROUGH THE MORNING WITH THIS UPDATE. THAT CHANGE WAS PREDICATED BY WEAK RADAR ECHOES AROUND ROLLA WITH FLURRIES REPORTED AT ROLLA AND ESTEVAN...AND SUBTLE HINTS OF SAID ACTIVITY OVER NORTH CENTRAL ND WITH RECENT HRRR RUNS. THE REST OF THE FORECAST IS GENERALLY ON TRACK. FOG OVER SOUTHWESTERN ND HAS OCCASIONALLY BEEN REDUCING THE VISIBILITY TO 1/2SM AT DICKINSON. HOWEVER...SUB-1SM TYPE OF VISIBILITIES HAVE NOT BEEN WIDESPREAD. THAT IS LIKELY DUE TO A SHALLOW MIXED LAYER STILL PRESENT AT THE SURFACE PER MODEL FORECAST SOUNDINGS /AND CONFIRMED BY THE 12 UTC OBSERVED SOUNDING AT BISMARCK/. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CST THU MAR 3 2016 THE MAIN FOCUS FOR THE SHORT TERM IS FOG AND CLOUD COVER TODAY AND FREEZING RAIN POTENTIAL TONIGHT. A VERY MOIST BOUNDARY LAYER AND EASTERLY UPSLOPING WINDS WILL KEEP MOST OF NORTH DAKOTA SOCKED IN UNDER LOW STRATUS AND PATCHY FOG MOST OF THE DAY. WARM AIR ADVECTION AND SOUTHWESTERLY FLOW AT THE SURFACE WILL BEGIN LATE THIS AFTERNOON ACROSS SOUTHWEST NORTH DAKOTA AHEAD OF AN APPROACHING CLIPPER. THIS WILL BEGIN TO ERODE THE LOW STRATUS. TONIGHT...A CLIPPER WILL SWING THROUGH NORTH DAKOTA BRINGING A CHANCE FOR SOME LIGHT PRECIPITATION. MODELS ARE INDICATING A WARM LAYER AROUND 850MB BEING ADVECTED IN ALONG THE LEADING EDGE OF THE SURFACE LOW. THIS WARMER AIR SHOULD BE SUFFICIENT TO MELT ANY ICE CRYSTALS THAT FALL ALOFT. DUE TO THE TIMING OF THIS SYSTEM (DURING THE OVERNIGHT AND EARLY MORNING HOURS) SURFACE TEMPERATURES WILL BE BELOW FREEZING. THIS COULD LEAD TO SOME LIGHT FREEZING RAIN FOR PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. THERE IS SOME UNCERTAINTY AND DISPARITY BETWEEN THE MODELS ON EXACTLY HOW MUCH PRECIPITATION COULD FALL. SOME MODELS ARE ALMOST COMPLETELY DRY WITH THE PASSING OF THE LOW...WHILE OTHER MODELS BRING IN A FEW HUNDRETHS OF PRECIPITATION. ONLY A LITTLE BIT OF MOISTURE COULD CAUSE SOME SLICK CONDITIONS SO THIS SITUATION WILL BE CLOSELY MONITORED. AT THIS TIME WE DON`T FEEL CONFIDENT ENOUGH GIVEN THE UNCERTAINTY IN THE DIFFERENT MODEL SOLUTIONS TO ISSUE ANY HEADLINES OR HIGHLIGHT THIS THREAT ANY FURTHER THAN THE HAZARDOUS WEATHER OUTLOOK AND WEATHER STORY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 342 AM CST THU MAR 3 2016 A MILD AND WINDY FRIDAY WILL BE FOLLOWED BY A VERY WARM WEEKEND AND AN INCREASING CHANCE OF PRECIPITATION MONDAY AND TUESDAY. A SLIGHT CHANCE OF LIGHT FREEZING RAIN CONTINUES THROUGH 15 UTC FRIDAY MORNING OVER EAST CENTRAL ND...BUT WILL ABRUPTLY END AS ANY PRECIPITATION EXITS THE AREA AND SURFACE TEMPERATURES RISE ABOVE 32 F. A COLD FRONT WILL CROSS THE AREA FRIDAY MORNING AND LOW-LEVEL NORTHWEST FLOW WILL INCREASE IN ITS WAKE WITH THE GFS RUN FROM 00 UTC SIMULATING BOUNDARY LAYER WINDS AROUND 30 KT ON FRIDAY. PRESSURE RISES ARE NOT MUCH TO WRITE HOME ABOUT AT ONLY 2-3 MB/3 HOURS ON THE GFS /AND LESS ON THE 00 UTC NAM/ AND PEAK WINDS AT THE TOP OF THE WELL-MIXED LAYER FRIDAY AFTERNOON BASED ON FORECAST SOUNDINGS ARE GENERALLY UNDER 40 KT. THUS...WHILE A WINDY DAY IS EXPECTED...SPEEDS WILL LIKELY STAY UNDER ADVISORY CRITERIA IF TRENDS IN THE 00 UTC GUIDANCE SUITE ARE CORRECT. ON THE LARGE SCALE...HEIGHTS WILL BUILD ALOFT ACROSS THE REGION THIS WEEKEND DOWNSTREAM OF A POWERFUL PACIFIC JET THAT WILL DIG INTO THE WESTERN UNITED STATES...CARVING OUT A 500-MB TROUGH BY EARLY NEXT WEEK. GLOBAL MODEL GUIDANCE HAS BEEN STEADFAST IN ITS PREDICTION OF THESE KEY FEATURES THE LAST SEVERAL DAYS...RAISING OUR CONFIDENCE IN A VERY WARM WEEKEND BENEATH THE RIDGING ALOFT. IN FACT...WE WEIGHTED THE FORECAST A BIT TOWARD THE WARMER EDGE OF THE 00 UTC GUIDANCE GIVEN THE BREADTH OF EXPECTED WARM AIR ADVECTION AND MIXING...WITH WIDESPREAD 50S AND LOWER 60S F OVER MOST OF THE AREA ON SATURDAY...AND MANY 60S F LIKELY ON SUNDAY. IT WILL BE BREEZY...ESPECIALLY ON SATURDAY...PERHAPS ELEVATING THE RISK OF GRASS FIRES A BIT THIS WEEKEND TOO. BY MONDAY AND TUESDAY...A LEAD NORTHERN-STREAM SHORTWAVE TROUGH IS FORECAST TO EJECT INTO THE NORTHERN PLAINS OUT OF THE THEN- SPLITTING LONGWAVE TROUGH. HOWEVER...THE PREDICTABILITY OF ITS EVOLUTION IS LOW...SO FOR NOW WE ARE MERELY ADVERTISING CHANCE POPS AND A COOLING TREND IN THE MONDAY AND TUESDAY FORECAST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 636 AM CST THU MAR 3 2016 MVFR/IFR CIGS ACROSS THE TERMINALS UNTIL LATE AFTERNOON AND THIS EVENING. AREAS OF FOG ALSO EXPECTED INTO MID MORNING THURSDAY ESPECIALLY AT KDIK WITH IFR VSBYS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MM SHORT TERM...AJ LONG TERM...CJS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
636 AM CST THU MAR 3 2016 .UPDATE... ISSUED AT 636 AM CST THU MAR 3 2016 WE ADDED ISOLATED FLURRIES TO THE FORECAST FROM CROSBY EASTWARD TO BOTTINEAU...ROLLA AND RUGBY THROUGH THE MORNING WITH THIS UPDATE. THAT CHANGE WAS PREDICATED BY WEAK RADAR ECHOES AROUND ROLLA WITH FLURRIES REPORTED AT ROLLA AND ESTEVAN...AND SUBTLE HINTS OF SAID ACTIVITY OVER NORTH CENTRAL ND WITH RECENT HRRR RUNS. THE REST OF THE FORECAST IS GENERALLY ON TRACK. FOG OVER SOUTHWESTERN ND HAS OCCASIONALLY BEEN REDUCING THE VISIBILITY TO 1/2SM AT DICKINSON. HOWEVER...SUB-1SM TYPE OF VISIBILITIES HAVE NOT BEEN WIDESPREAD. THAT IS LIKELY DUE TO A SHALLOW MIXED LAYER STILL PRESENT AT THE SURFACE PER MODEL FORECAST SOUNDINGS /AND CONFIRMED BY THE 12 UTC OBSERVED SOUNDING AT BISMARCK/. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CST THU MAR 3 2016 THE MAIN FOCUS FOR THE SHORT TERM IS FOG AND CLOUD COVER TODAY AND FREEZING RAIN POTENTIAL TONIGHT. A VERY MOIST BOUNDARY LAYER AND EASTERLY UPSLOPING WINDS WILL KEEP MOST OF NORTH DAKOTA SOCKED IN UNDER LOW STRATUS AND PATCHY FOG MOST OF THE DAY. WARM AIR ADVECTION AND SOUTHWESTERLY FLOW AT THE SURFACE WILL BEGIN LATE THIS AFTERNOON ACROSS SOUTHWEST NORTH DAKOTA AHEAD OF AN APPROACHING CLIPPER. THIS WILL BEGIN TO ERODE THE LOW STRATUS. TONIGHT...A CLIPPER WILL SWING THROUGH NORTH DAKOTA BRINGING A CHANCE FOR SOME LIGHT PRECIPITATION. MODELS ARE INDICATING A WARM LAYER AROUND 850MB BEING ADVECTED IN ALONG THE LEADING EDGE OF THE SURFACE LOW. THIS WARMER AIR SHOULD BE SUFFICIENT TO MELT ANY ICE CRYSTALS THAT FALL ALOFT. DUE TO THE TIMING OF THIS SYSTEM (DURING THE OVERNIGHT AND EARLY MORNING HOURS) SURFACE TEMPERATURES WILL BE BELOW FREEZING. THIS COULD LEAD TO SOME LIGHT FREEZING RAIN FOR PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. THERE IS SOME UNCERTAINTY AND DISPARITY BETWEEN THE MODELS ON EXACTLY HOW MUCH PRECIPITATION COULD FALL. SOME MODELS ARE ALMOST COMPLETELY DRY WITH THE PASSING OF THE LOW...WHILE OTHER MODELS BRING IN A FEW HUNDRETHS OF PRECIPITATION. ONLY A LITTLE BIT OF MOISTURE COULD CAUSE SOME SLICK CONDITIONS SO THIS SITUATION WILL BE CLOSELY MONITORED. AT THIS TIME WE DON`T FEEL CONFIDENT ENOUGH GIVEN THE UNCERTAINTY IN THE DIFFERENT MODEL SOLUTIONS TO ISSUE ANY HEADLINES OR HIGHLIGHT THIS THREAT ANY FURTHER THAN THE HAZARDOUS WEATHER OUTLOOK AND WEATHER STORY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 342 AM CST THU MAR 3 2016 A MILD AND WINDY FRIDAY WILL BE FOLLOWED BY A VERY WARM WEEKEND AND AN INCREASING CHANCE OF PRECIPITATION MONDAY AND TUESDAY. A SLIGHT CHANCE OF LIGHT FREEZING RAIN CONTINUES THROUGH 15 UTC FRIDAY MORNING OVER EAST CENTRAL ND...BUT WILL ABRUPTLY END AS ANY PRECIPITATION EXITS THE AREA AND SURFACE TEMPERATURES RISE ABOVE 32 F. A COLD FRONT WILL CROSS THE AREA FRIDAY MORNING AND LOW-LEVEL NORTHWEST FLOW WILL INCREASE IN ITS WAKE WITH THE GFS RUN FROM 00 UTC SIMULATING BOUNDARY LAYER WINDS AROUND 30 KT ON FRIDAY. PRESSURE RISES ARE NOT MUCH TO WRITE HOME ABOUT AT ONLY 2-3 MB/3 HOURS ON THE GFS /AND LESS ON THE 00 UTC NAM/ AND PEAK WINDS AT THE TOP OF THE WELL-MIXED LAYER FRIDAY AFTERNOON BASED ON FORECAST SOUNDINGS ARE GENERALLY UNDER 40 KT. THUS...WHILE A WINDY DAY IS EXPECTED...SPEEDS WILL LIKELY STAY UNDER ADVISORY CRITERIA IF TRENDS IN THE 00 UTC GUIDANCE SUITE ARE CORRECT. ON THE LARGE SCALE...HEIGHTS WILL BUILD ALOFT ACROSS THE REGION THIS WEEKEND DOWNSTREAM OF A POWERFUL PACIFIC JET THAT WILL DIG INTO THE WESTERN UNITED STATES...CARVING OUT A 500-MB TROUGH BY EARLY NEXT WEEK. GLOBAL MODEL GUIDANCE HAS BEEN STEADFAST IN ITS PREDICTION OF THESE KEY FEATURES THE LAST SEVERAL DAYS...RAISING OUR CONFIDENCE IN A VERY WARM WEEKEND BENEATH THE RIDGING ALOFT. IN FACT...WE WEIGHTED THE FORECAST A BIT TOWARD THE WARMER EDGE OF THE 00 UTC GUIDANCE GIVEN THE BREADTH OF EXPECTED WARM AIR ADVECTION AND MIXING...WITH WIDESPREAD 50S AND LOWER 60S F OVER MOST OF THE AREA ON SATURDAY...AND MANY 60S F LIKELY ON SUNDAY. IT WILL BE BREEZY...ESPECIALLY ON SATURDAY...PERHAPS ELEVATING THE RISK OF GRASS FIRES A BIT THIS WEEKEND TOO. BY MONDAY AND TUESDAY...A LEAD NORTHERN-STREAM SHORTWAVE TROUGH IS FORECAST TO EJECT INTO THE NORTHERN PLAINS OUT OF THE THEN- SPLITTING LONGWAVE TROUGH. HOWEVER...THE PREDICTABILITY OF ITS EVOLUTION IS LOW...SO FOR NOW WE ARE MERELY ADVERTISING CHANCE POPS AND A COOLING TREND IN THE MONDAY AND TUESDAY FORECAST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 636 AM CST THU MAR 3 2016 MVFR/IFR CIGS ACROSS THE TERMINALS UNTIL LATE AFTERNOON AND THIS EVENING. AREAS OF FOG ALSO EXPECTED INTO MID MORNING THURSDAY ESPECIALLY AT KDIK WITH IFR VSBYS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CJS SHORT TERM...AJ LONG TERM...CJS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
706 AM EST THU MAR 3 2016 .SYNOPSIS... LINGERING SNOW SHOWERS AND FLURRIES WILL GIVE WAY TO FAIR WEATHER LATER TODAY. A WIDESPREAD LIGHT SNOW ACCUMULATION OF 1 TO 2 INCHES IS EXPECTED TONIGHT INTO FRIDAY MORNING. ADDITIONAL LIGHT SNOW IS POSSIBLE SATURDAY EVENING INTO EARLY SUNDAY. THE FORECAST FOR NEXT WEEK LOOKS MILD WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES. && .NEAR TERM /THROUGH TONIGHT/... IR SATELLITE AND RADAR TRENDS SHOW DECREASING COVERAGE OF LAKE STRATOCU AND SNOW SHOWERS/FLURRIES. MOST AREAS WILL SEE SUNSHINE THIS MORNING BEFORE CLOUDS INCREASE FROM THE WEST AND THICKEN THROUGH THE AFTERNOON. SHORTWAVE DIGGING SOUTHEAST INTO THE MID MS VALLEY THIS MORNING WILL MOVE THROUGH THE TN VALLEY TODAY BEFORE EJECTING ENEWD ACROSS THE SOUTHERN APPALACHIANS/MID ATLANTIC STATES TONIGHT INTO EARLY FRIDAY. INCREASING LOW LEVEL WARM ADVECTION INTERACTING WITH LOW-MID LEVEL FGEN WILL SUPPORT A ZONE OF ISENTROPIC LIFT- GENERATED SNOW SPREADING WEST-TO-EAST ACROSS MUCH OF CENTRAL PA FROM LATE THIS EVENING/EARLY TONIGHT INTO FRIDAY MORNING. AT THIS POINT THE THURSDAY EVENING COMMUTE DOES NOT APPEAR TO BE IMPACTED BY THE INCOMING LIGHT SNOW. THE BROAD AREA OF LIFT IS LOCATED WELL TO THE NORTH OF A DEVELOPING SFC LOW NEAR THE NC OBX BY 04/12Z. MAIN FCST ISSUE IS TOTAL SNOW FCST AMTS AND POTENTIAL NEED FOR A WINTER WX ADVISORY ACROSS THE LOWER SUSQ VALLEY. WE STRONGLY CONSIDERED ISSUING AN ADVISORY FOR THE LOWER SUSQ COUNTIES BASED ON NEW 2 INCH CRITERIA AND IMPACTS RELATED TO THE FRIDAY MORNING COMMUTE. CONSENSUS BLEND OF GLOBAL/REGIONAL MODEL QPF FAVORED 1.5-3 INCHES OF SNOW OVER MUCH OF THE AREA...BUT THE HI RES ENSEMBLE SSEO/NCAR OUTPUT CAME IN LOWER AT 1-2 INCHES WITH SUB-1 INCH AMTS IN THE LOWEST ELEVATIONS. WE DECIDED TO HOLD OFF ON THE ADVY FOR NOW AND ALLOW DAYSHIFT TO EXAMINE THE HRRR AND NEWER MDL DATA...STILL WITH SUFFICIENT LEAD TIME/HEADS UP FOR LIGHT SNOW ACCUMULATION IMPACTS (FRIDAY AM COMMUTE). WE COULD SEE A BOOM SCENARIO WHERE SOME PERSISTENT FGEN BANDING AND HIGHER SLR/S AFFORD SOME LOCAL 3+ INCH AMOUNTS...WHILE ON THE OTHER HAND COULD SEE LOWER AMOUNTS VERIFYING GIVEN LIMITED FORCING AND BEST MOISTURE TO THE SOUTH. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... LGT SNOW SHOULD TAPER OFF BY LATE AM ACROSS THE AREA...AS MID LVL TROF AXIS SWINGS EAST OF THE AREA. DEEP MOISTURE ASSOC WITH DEVELOPING COASTAL LOW NR CAPE HATTERAS IS PROGGED BY ALL MDL DATA TO REMAIN SOUTH OF PA...SO SNOW ACCUMS SHOULD REMAIN LIGHT. SOME BRIGHTENING EXPECTED BY AFTN PER MDL SOUNDINGS...AS COASTAL LOW EXITS THE E COAST. HOWEVER...DIURNAL HEATING COMBINED W/COOL TEMPS ALOFT SHOULD RESULT IN QUITE A BIT OF LINGERING STRATOCU. BLEND OF LATEST SUPERBLEND AND ECME MOS SUPPORT HIGH TEMPS SEVERAL DEG BLW AVG...MAINLY 35-40F. CLEARING SKIES AND LIGHT WIND UPON ARRIVAL OF SFC RIDGE SHOULD ALLOW TEMPS TO FALL QUICKLY FRI EVENING. HOWEVER...COMPLICATING FACTOR W/REGARD TO MIN TEMPS WILL BE THE POTENTIAL ARRIVAL OF CLOUDS BEFORE DAWN ASSOC WITH APPROACHING CLIPPER. ENSEMBLE TEMP PLUMES SHOWING A FAIR AMT OF SPREAD IN THE MIN TEMPS...ILLUSTRATING THE UNCERTAINTY. WILL TAKE THE MIDDLE ROAD FOR NOW WITH A FCST OF UTEENS NORTH TO M20S SE. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... A FAIR AMT OF AGREEMENT AMONG MED RANGE MDLS W/REGARD TO STRENGTH/TIMING OF WEEKEND CLIPPER...ALL OF WHICH POINT TOWARD A RELATIVELY WEAK AND DEFINITELY MOISTURE-STARVED SYSTEM. LATEST GEFS/SREF MEAN QPF SUPPORTS A 1-2 INCH SNOWFALL WITH THE W MTNS CLIMATOLOGICALLY FAVORED FOR THE HIGHEST AMTS. ALTHOUGH MDL TIMING OF SFC LOW SUGGEST THE STEADIEST SNOW SHOULD FALL SAT NIGHT...SOME VERY LGT SNOW IS ALSO POSSIBLE DURING THE DAYTIME SAT IN WAA AHEAD OF LEAD SHORTWAVE. ABV FREEZING SFC TEMPS AND MARCH SUN ANGLE SHOULD PRECLUDE DAYTIME ACCUMS. BRIGHTENING SKIES BUT STILL CHILLY WX ANTICIPATED SUNDAY...AS HIGH PRES BUILDS IN FROM THE WEST. WIDE CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP NEXT WEEK...AS ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 00Z ECENS. HAVE CONSERVATIVELY BUMPED TEMPS UPWARD TO ARND 70F BY WED OVR SOUTHERN PA. A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF COULD POTENTIALLY COME CLOSE ENOUGH TO NW PA TO BRING SHOWERS BY MIDWEEK. HOWEVER...LATEST ECENS INDICATES THE MORE LIKELY SCENARIO KEEPS FRONT AND CHC OF RAIN NW OF PENNSYLVANIA. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... FOR THE 03/12Z TAFS THROUGH 04/12Z FRIDAY ISSUED AT 705 AM EST MAR 03 2016 LINGERING MVFR CIG AT JST WILL IMPROVE TO VFR BY 14Z. INCREASING AND THICKENING VFR MID CLOUDS WILL SPREAD FROM WEST-TO-EAST ACROSS THE AIRSPACE BY THIS AFTERNOON BEFORE CIGS TREND LOWER THIS EVENING. WIDESPREAD -SN AND IFR VIS WILL IMPACT ALL TERMINALS TONIGHT INTO EARLY FRIDAY MORNING. OUTLOOK... FRI...AM -SN WITH MVFR CIGS. IMPROVING CONDS BY FRI EVE/NGT. SAT...VFR/MVFR CIGS EARLY THEN CHC OF -SN SAT NGT. SUN...MVFR CIGS WEST BCMG VFR. MON...VFR/NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STEINBUGL NEAR TERM...FITZGERALD/STEINBUGL SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
630 AM EST THU MAR 3 2016 .SYNOPSIS... LINGERING SNOW SHOWERS AND FLURRIES WILL GIVE WAY TO FAIR WEATHER LATER TODAY. A WIDESPREAD LIGHT SNOW ACCUMULATION OF 1 TO 2 INCHES IS EXPECTED TONIGHT INTO FRIDAY MORNING. ADDITIONAL LIGHT SNOW IS POSSIBLE SATURDAY EVENING INTO EARLY SUNDAY. THE FORECAST FOR NEXT WEEK LOOKS MILD WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES. && .NEAR TERM /THROUGH TONIGHT/... IR SATELLITE AND RADAR TRENDS SHOW DECREASING COVERAGE OF LAKE STRATOCU AND SNOW SHOWERS/FLURRIES. MOST AREAS SHOULD SEE SOME SUNSHINE THIS MORNING BEFORE CLOUDS INCREASE FROM THE WEST AND THICKEN THROUGH THE AFTERNOON. SHORTWAVE DIGGING SOUTHEAST INTO THE MID MS VALLEY THIS MORNING WILL MOVE THROUGH THE TN VALLEY TODAY BEFORE EJECTING ENEWD ACROSS THE SOUTHERN APPALACHIANS/MID ATLANTIC STATES TONIGHT INTO EARLY FRIDAY. INCREASING LOW LEVEL WARM ADVECTION INTERACTING WITH LOW-MID LEVEL FGEN WILL SUPPORT A ZONE OF ISENTROPIC LIFT- GENERATED SNOW SPREADING WEST-TO-EAST ACROSS MUCH OF CENTRAL PA FROM LATE THIS EVENING/EARLY TONIGHT INTO FRIDAY MORNING. AT THIS POINT THE THURSDAY EVENING COMMUTE DOES NOT APPEAR TO BE IMPACTED BY THE INCOMING LIGHT SNOW. THE BROAD AREA OF LIFT IS LOCATED WELL TO THE NORTH OF A DEVELOPING SFC LOW NEAR THE NC OBX BY 04/12Z. MAIN FCST ISSUE IS TOTAL SNOW FCST AMTS AND POTENTIAL NEED FOR A WINTER WX ADVISORY ACROSS THE LOWER SUSQ VALLEY. WE STRONGLY CONSIDERED ISSUING AN ADVISORY FOR THE LOWER SUSQ COUNTIES BASED ON NEW 2 INCH CRITERIA AND IMPACTS RELATED TO THE FRIDAY MORNING COMMUTE. CONSENSUS BLEND OF GLOBAL/REGIONAL MODEL QPF FAVORED 1.5-3 INCHES OF SNOW OVER MUCH OF THE AREA...BUT THE HI RES ENSEMBLE SSEO/NCAR OUTPUT CAME IN LOWER AT 1-2 INCHES WITH SUB-1 INCH AMTS IN THE LOWEST ELEVATIONS. WE DECIDED TO HOLD OFF ON THE ADVY FOR NOW AND ALLOW DAYSHIFT TO EXAMINE THE HRRR AND NEWER MDL DATA...STILL WITH SUFFICIENT LEAD TIME/HEADS UP FOR LIGHT SNOW ACCUMULATION IMPACTS (FRIDAY AM COMMUTE). WE COULD SEE A BOOM SCENARIO WHERE SOME PERSISTENT FGEN BANDING AND HIGHER SLR/S AFFORD SOME LOCAL 3+ INCH AMOUNTS...WHILE ON THE OTHER HAND COULD SEE LOWER AMOUNTS VERIFYING GIVEN LIMITED FORCING AND BEST MOISTURE TO THE SOUTH. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... LGT SNOW SHOULD TAPER OFF BY LATE AM ACROSS THE AREA...AS MID LVL TROF AXIS SWINGS EAST OF THE AREA. DEEP MOISTURE ASSOC WITH DEVELOPING COASTAL LOW NR CAPE HATTERAS IS PROGGED BY ALL MDL DATA TO REMAIN SOUTH OF PA...SO SNOW ACCUMS SHOULD REMAIN LIGHT. SOME BRIGHTENING EXPECTED BY AFTN PER MDL SOUNDINGS...AS COASTAL LOW EXITS THE E COAST. HOWEVER...DIURNAL HEATING COMBINED W/COOL TEMPS ALOFT SHOULD RESULT IN QUITE A BIT OF LINGERING STRATOCU. BLEND OF LATEST SUPERBLEND AND ECME MOS SUPPORT HIGH TEMPS SEVERAL DEG BLW AVG...MAINLY 35-40F. CLEARING SKIES AND LIGHT WIND UPON ARRIVAL OF SFC RIDGE SHOULD ALLOW TEMPS TO FALL QUICKLY FRI EVENING. HOWEVER...COMPLICATING FACTOR W/REGARD TO MIN TEMPS WILL BE THE POTENTIAL ARRIVAL OF CLOUDS BEFORE DAWN ASSOC WITH APPROACHING CLIPPER. ENSEMBLE TEMP PLUMES SHOWING A FAIR AMT OF SPREAD IN THE MIN TEMPS...ILLUSTRATING THE UNCERTAINTY. WILL TAKE THE MIDDLE ROAD FOR NOW WITH A FCST OF UTEENS NORTH TO M20S SE. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... A FAIR AMT OF AGREEMENT AMONG MED RANGE MDLS W/REGARD TO STRENGTH/TIMING OF WEEKEND CLIPPER...ALL OF WHICH POINT TOWARD A RELATIVELY WEAK AND DEFINITELY MOISTURE-STARVED SYSTEM. LATEST GEFS/SREF MEAN QPF SUPPORTS A 1-2 INCH SNOWFALL WITH THE W MTNS CLIMATOLOGICALLY FAVORED FOR THE HIGHEST AMTS. ALTHOUGH MDL TIMING OF SFC LOW SUGGEST THE STEADIEST SNOW SHOULD FALL SAT NIGHT...SOME VERY LGT SNOW IS ALSO POSSIBLE DURING THE DAYTIME SAT IN WAA AHEAD OF LEAD SHORTWAVE. ABV FREEZING SFC TEMPS AND MARCH SUN ANGLE SHOULD PRECLUDE DAYTIME ACCUMS. BRIGHTENING SKIES BUT STILL CHILLY WX ANTICIPATED SUNDAY...AS HIGH PRES BUILDS IN FROM THE WEST. WIDE CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP NEXT WEEK...AS ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 00Z ECENS. HAVE CONSERVATIVELY BUMPED TEMPS UPWARD TO ARND 70F BY WED OVR SOUTHERN PA. A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF COULD POTENTIALLY COME CLOSE ENOUGH TO NW PA TO BRING SHOWERS BY MIDWEEK. HOWEVER...LATEST ECENS INDICATES THE MORE LIKELY SCENARIO KEEPS FRONT AND CHC OF RAIN NW OF PENNSYLVANIA. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... FOR THE 03/06Z TAFS THROUGH 04/06Z ISSUED AT 127 AM EST MAR 03 2016 LINGERING -SHSN AND MVFR TO LOW VFR CIGS /2-5KFT AGL/ WILL CONTINUE ACROSS THE NW 1/2 OF THE AIRSPACE EARLY THIS MORNING. EXPECT -SHSN TO DIMINISH BY LATE MORNING WITH MOST SITES VFR. THICKENING VFR MID CLOUDS WILL SPREAD ACROSS THE AIRSPACE THIS AFTERNOON BEFORE CIGS TREND LOWER THIS EVENING. WIDESPREAD -SN IS FCST TO DEVELOP INTO TONIGHT AND HAVE ADDED IFR GROUP 00-04Z WHICH SHOULD PERSIST INTO EARLY FRIDAY MORNING. OUTLOOK... FRI...-SN WITH MVFR CIGS. IMPROVING CONDS BY FRI EVE/NGT. SAT...VFR/MVFR CIGS EARLY THEN CHC OF -SN SAT NGT. SUN...MVFR CIGS WEST BCMG VFR. MON...VFR/NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STEINBUGL NEAR TERM...FITZGERALD/STEINBUGL SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
555 AM EST THU MAR 3 2016 .SYNOPSIS... LINGERING SNOW SHOWERS AND FLURRIES WILL GIVE WAY TO FAIR WEATHER LATER TODAY. A WIDESPREAD LIGHT SNOW ACCUMULATION OF 1 TO 2 INCHES IS EXPECTED TONIGHT INTO FRIDAY MORNING. ADDITIONAL LIGHT SNOW IS POSSIBLE SATURDAY EVENING INTO EARLY SUNDAY. THE FORECAST FOR NEXT WEEK LOOKS MILD WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES. && .NEAR TERM /THROUGH TONIGHT/... IR SATELLITE AND RADAR TRENDS SHOW DECREASING COVERAGE OF LAKE STRATOCU AND SNOW SHOWERS/FLURRIES. MOST AREAS SHOULD SEE SOME SUNSHINE THIS MORNING BEFORE CLOUDS INCREASE FROM THE WEST AND THICKEN THROUGH THE AFTERNOON. SHORTWAVE DIGGING SOUTHEAST INTO THE MID MS VALLEY THIS MORNING WILL MOVE THROUGH THE TN VALLEY TODAY BEFORE EJECTING ENEWD ACROSS THE SOUTHERN APPALACHIANS/MID ATLANTIC STATES TONIGHT INTO EARLY FRIDAY. INCREASING LOW LEVEL WARM ADVECTION INTERACTING WITH LOW-MID LEVEL FGEN WILL SUPPORT A ZONE OF ISENTROPIC LIFT- GENERATED SNOW SPREADING WEST-TO-EAST ACROSS MUCH OF CENTRAL PA FROM LATE THIS EVENING/EARLY TONIGHT INTO FRIDAY MORNING. AT THIS POINT THE THURSDAY EVENING COMMUTE DOES NOT APPEAR TO BE IMPACTED BY THE INCOMING LIGHT SNOW. THE BROAD AREA OF LIFT IS LOCATED WELL TO THE NORTH OF A DEVELOPING SFC LOW NEAR THE NC OBX BY 04/12Z. MAIN FCST ISSUE IS TOTAL SNOW FCST AMTS AND POTENTIAL NEED FOR A WINTER WX ADVISORY ACROSS THE LOWER SUSQ VALLEY. WE STRONGLY CONSIDERED ISSUING AN ADVISORY FOR THE LOWER SUSQ COUNTIES BASED ON NEW 2 INCH CRITERIA AND IMPACTS RELATED TO THE FRIDAY MORNING COMMUTE. CONSENSUS BLEND OF GLOBAL/REGIONAL MODEL QPF FAVORED 1.5-3 INCHES OF SNOW OVER MUCH OF THE AREA...BUT THE HI RES ENSEMBLE SSEO/NCAR OUTPUT CAME IN LOWER AT 1-2 INCHES WITH SUB-1 INCH AMTS IN THE LOWEST ELEVATIONS. WE DECIDED TO HOLD OFF ON THE ADVY FOR NOW AND ALLOW DAYSHIFT TO EXAMINE THE HRRR AND NEWER MDL DATA...STILL WITH SUFFICIENT LEAD TIME/HEADS UP FOR LIGHT SNOW ACCUMULATION IMPACTS (FRIDAY AM COMMUTE). WE COULD SEE A BOOM SCENARIO WHERE SOME PERSISTENT FGEN BANDING AND HIGHER SLR/S AFFORD SOME LOCAL 3+ INCH AMOUNTS...WHILE ON THE OTHER HAND COULD SEE LOWER AMOUNTS VERIFYING GIVEN LIMITED FORCING AND BEST MOISTURE TO THE SOUTH. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... LGT SNOW SHOULD TAPER OFF BY LATE AM ACROSS THE AREA...AS MID LVL TROF AXIS SWINGS EAST OF THE AREA. DEEP MOISTURE ASSOC WITH DEVELOPING COASTAL LOW NR CAPE HATTERAS IS PROGGED BY ALL MDL DATA TO REMAIN SOUTH OF PA...SO SNOW ACCUMS SHOULD REMAIN LIGHT. SOME BRIGHTENING EXPECTED BY AFTN PER MDL SOUNDINGS...AS COASTAL LOW EXITS THE E COAST. HOWEVER...DIURNAL HEATING COMBINED W/COOL TEMPS ALOFT SHOULD RESULT IN QUITE A BIT OF LINGERING STRATOCU. BLEND OF LATEST SUPERBLEND AND ECME MOS SUPPORT HIGH TEMPS SEVERAL DEG BLW AVG...MAINLY 35-40F. CLEARING SKIES AND LIGHT WIND UPON ARRIVAL OF SFC RIDGE SHOULD ALLOW TEMPS TO FALL QUICKLY FRI EVENING. HOWEVER...COMPLICATING FACTOR W/REGARD TO MIN TEMPS WILL BE THE POTENTIAL ARRIVAL OF CLOUDS BEFORE DAWN ASSOC WITH APPROACHING CLIPPER. ENSEMBLE TEMP PLUMES SHOWING A FAIR AMT OF SPREAD IN THE MIN TEMPS...ILLUSTRATING THE UNCERTAINTY. WILL TAKE THE MIDDLE ROAD FOR NOW WITH A FCST OF UTEENS NORTH TO M20S SE. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... A FAIR AMT OF AGREEMENT AMONG MED RANGE MDLS W/REGARD TO STRENGTH/TIMING OF WEEKEND CLIPPER...ALL OF WHICH POINT TOWARD A RELATIVELY WEAK AND DEFINITELY MOISTURE-STARVED SYSTEM. LATEST GEFS/SREF MEAN QPF SUPPORTS A 1-2 INCH SNOWFALL WITH THE W MTNS CLIMATOLOGICALLY FAVORED FOR THE HIGHEST AMTS. ALTHOUGH MDL TIMING OF SFC LOW SUGGEST THE STEADIEST SNOW SHOULD FALL SAT NIGHT...SOME VERY LGT SNOW IS ALSO POSSIBLE DURING THE DAYTIME SAT IN WAA AHEAD OF LEAD SHORTWAVE. ABV FREEZING SFC TEMPS AND MARCH SUN ANGLE SHOULD PRECLUDE DAYTIME ACCUMS. BRIGHTENING SKIES BUT STILL CHILLY WX ANTICIPATED SUNDAY...AS HIGH PRES BUILDS IN FROM THE WEST. WIDE CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP NEXT WEEK...AS ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 00Z ECENS. HAVE CONSERVATIVELY BUMPED TEMPS UPWARD TO ARND 70F BY WED OVR SOUTHERN PA. A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF COULD POTENTIALLY COME CLOSE ENOUGH TO NW PA TO BRING SHOWERS BY MIDWEEK. HOWEVER...LATEST ECENS INDICATES THE MORE LIKELY SCENARIO KEEPS FRONT AND CHC OF RAIN NW OF PENNSYLVANIA. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... FOR THE 03/06Z TAFS THROUGH 04/06Z ISSUED AT 127 AM EST MAR 03 2016 LINGERING -SHSN AND MVFR TO LOW VFR CIGS /2-5KFT AGL/ WILL CONTINUE ACROSS THE NW 1/2 OF THE AIRSPACE EARLY THIS MORNING. EXPECT -SHSN TO DIMINISH BY LATE MORNING WITH MOST SITES VFR. THICKENING VFR MID CLOUDS WILL SPREAD ACROSS THE AIRSPACE THIS AFTERNOON BEFORE CIGS TREND LOWER THIS EVENING. WIDESPREAD -SN IS FCST TO DEVELOP INTO TONIGHT AND HAVE ADDED IFR GROUP 00-04Z WHICH SHOULD PERSIST INTO EARLY FRIDAY MORNING. OUTLOOK... FRI...-SN WITH MVFR CIGS. IMPROVING CONDS BY FRI EVE/NGT. SAT...VFR/MVFR CIGS EARLY THEN CHC OF -SN SAT NGT. SUN...MVFR CIGS WEST BCMG VFR. MON...VFR/NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STEINBUGL NEAR TERM...STEINBUGL SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
427 AM EST THU MAR 3 2016 .SYNOPSIS... LINGERING SNOW SHOWERS AND FLURRIES WILL GIVE WAY TO FAIR WEATHER LATER TODAY. A WIDESPREAD LIGHT SNOW ACCUMULATION OF 1 TO 2 INCHES IS EXPECTED TONIGHT INTO FRIDAY MORNING. ADDITIONAL LIGHT SNOW IS POSSIBLE SATURDAY EVENING INTO EARLY SUNDAY. THE FORECAST FOR NEXT WEEK LOOKS MILD WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... IR SATELLITE AND RADAR TRENDS SHOW DECREASING COVERAGE OF LAKE STRATOCU AND SNOW SHOWERS/FLURRIES. MOST AREAS SHOULD SEE SOME SUNSHINE THIS MORNING BEFORE CLOUDS INCREASE FROM THE WEST AND THICKEN THROUGH THE AFTERNOON. SHORTWAVE DIGGING SOUTHEAST INTO THE MID MS VALLEY THIS MORNING WILL MOVE THROUGH THE TN VALLEY TODAY BEFORE EJECTING ENEWD ACROSS THE SOUTHERN APPALACHIANS/MID ATLANTIC STATES TONIGHT INTO EARLY FRIDAY. INCREASING LOW LEVEL WARM ADVECTION INTERACTING WITH LOW-MID LEVEL FGEN WILL SUPPORT A ZONE OF ISENTROPIC LIFT- GENERATED SNOW SPREADING WEST-TO-EAST ACROSS MUCH OF CENTRAL PA FROM LATE THIS EVENING/EARLY TONIGHT INTO FRIDAY MORNING. AT THIS POINT THE THURSDAY EVENING COMMUTE DOES NOT APPEAR TO BE IMPACTED BY THE INCOMING LIGHT SNOW. THE BROAD AREA OF LIFT IS LOCATED WELL TO THE NORTH OF A DEVELOPING SFC LOW NEAR THE NC OBX BY 04/12Z. MAIN FCST ISSUE IS TOTAL SNOW FCST AMTS AND POTENTIAL NEED FOR A WINTER WX ADVISORY ACROSS THE LOWER SUSQ VALLEY. WE STRONGLY CONSIDERED ISSUING AN ADVISORY FOR THE LOWER SUSQ COUNTIES BASED ON NEW 2 INCH CRITERIA AND IMPACTS RELATED TO THE FRIDAY MORNING COMMUTE. CONSENSUS BLEND OF GLOBAL/REGIONAL MODEL QPF FAVORED 1.5-3 INCHES OF SNOW OVER MUCH OF THE AREA...BUT THE HI RES ENSEMBLE SSEO/NCAR OUTPUT CAME IN LOWER AT 1-2 INCHES WITH SUB-1 INCH AMTS IN THE LOWEST ELEVATIONS. WE DECIDED TO HOLD OFF ON THE ADVY FOR NOW AND ALLOW DAYSHIFT TO EXAMINE THE HRRR AND NEWER MDL DATA...STILL WITH SUFFICIENT LEAD TIME/HEADS UP FOR LIGHT SNOW ACCUMULATION IMPACTS (FRIDAY AM COMMUTE). WE COULD SEE A BOOM SCENARIO WHERE SOME PERSISTENT FGEN BANDING AND HIGHER SLR/S AFFORD SOME LOCAL 3+ INCH AMOUNTS...WHILE ON THE OTHER HAND COULD SEE LOWER AMOUNTS VERIFYING GIVEN LIMITED FORCING AND BEST MOISTURE TO THE SOUTH. && .SHORT TERM /8 AM THIS MORNING THROUGH FRIDAY NIGHT/... RIDGING SFC/ALOFT ARRIVING BEHIND DEPARTING STORM SYSTEM OFF THE EAST COAST WILL END PCPN EARLY FRIDAY. EARLY CLOUDS SHOULD DECREASE BY LATER IN THE DAY BEHIND A DRIER NORTHERLY FLOW...BUT QUICKLY FILL BACK IN FRI NIGHT INTO SATURDAY MORNING AHEAD OF CLIPPER LOW DIVING SOUTHEAST FROM MN TO NEAR CHICAGO IL BY 05/12Z. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... CLIPPER SHOULD BRING ANOTHER CHANCE FOR PRECIPITATION SATURDAY NIGHT THROUGH THE FIRST HALF OF SUNDAY. THE EC AND GFS...ALONG WITH THE ENSEMBLES ARE IN FAIR AGREEMENT ON THE POSITION AND TIMING OF THE TROUGH....THOUGH THE GEFS BEGINS TO DIVERGE IN ANY SOLUTION BY 12Z SUNDAY. SNOW REMAINS THE LIKELY PRECIP TYPE. A LARGE RIDGE SHOULD BUILD IN QUICKLY BEHIND THIS SYSTEM...BRINGING DRY WARM AIR TO THE REGION EARLY NEXT WEEK. THE TREND CONTINUES TO SHOW HIGH PRESSURE THROUGH MID WEEK WHICH SHOULD SUPPORT ABOVE NORMAL TEMPERATURES. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... FOR THE 03/06Z TAFS THROUGH 04/06Z ISSUED AT 127 AM EST MAR 03 2016 LINGERING -SHSN AND MVFR TO LOW VFR CIGS /2-5KFT AGL/ WILL CONTINUE ACROSS THE NW 1/2 OF THE AIRSPACE EARLY THIS MORNING. EXPECT -SHSN TO DIMINISH BY LATE MORNING WITH MOST SITES VFR. THICKENING VFR MID CLOUDS WILL SPREAD ACROSS THE AIRSPACE THIS AFTERNOON BEFORE CIGS TREND LOWER THIS EVENING. WIDESPREAD -SN IS FCST TO DEVELOP INTO TONIGHT AND HAVE ADDED IFR GROUP 00-04Z WHICH SHOULD PERSIST INTO EARLY FRIDAY MORNING. OUTLOOK... FRI...-SN WITH MVFR CIGS. IMPROVING CONDS BY FRI EVE/NGT. SAT...VFR/MVFR CIGS EARLY THEN CHC OF -SN SAT NGT. SUN...MVFR CIGS WEST BCMG VFR. MON...VFR/NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STEINBUGL NEAR TERM...STEINBUGL SHORT TERM...DANGELO/RXR LONG TERM...CERU AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1144 AM CST THU MAR 3 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 331 AM CST THU MAR 3 2016 DIFFICULT CLOUD FORECAST TODAY WITH A FAIR AMOUNT OF LOW LEVEL SATURATION ACROSS THE AREA. CURRENTLY HAVE A FAIR AMOUNT OF MID CLOUDS ACROSS SOUTHWEST MINNESOTA AND NORTHWEST IOWA...HOWEVER...FURTHER TO THE WEST...MUCH LOWER CLOUDS ARE DEVELOPING AS THE SURFACE FLOW BECOMES MORE NORTHERLY. MODEL SOUNDING SUGGEST A STRATUS LAYER WILL TRY TO DEVELOP AT THE TOP OF THE BOUNDARY LAYER TODAY. WITH RELATIVELY POOR MIXING CONDITIONS AND SIGNIFICANT CLOUD COVER...HAVE LOWERED FORECAST HIGHS TODAY. SHORT TERM HIGH RES MODELS INDICATE A FEW TRENDS ACROSS THE EASTERN EDGE OF THE AREA THAT NEED WATCHING. FIRST...BOTH THE HRRR AND THE RAP SUGGEST FOG DEVELOPING ACROSS NORTHWEST IOWA AND EXPANDING WESTWARD TOWARDS THE I-29 CORRIDOR. WITH FOG STARTING TO DEVELOP AT STORM LAKE CONFIDENCE IS GROWING WITH FOG AND WILL HAVE SOME PATCHY AND AREAS MENTIONED. OTHER CONCERN IS WITH A WEAK SHORTWAVE MOVING OUT OF NORTH DAKOTA INTO SOUTHWEST MINNESOTA. AS THIS WAVE PASSES THROUGH IN THE 12-15Z TIME FRAME...MODEL SOUNDINGS SUGGEST THAT SATURATION MAY GET DEEP ENOUGH TO TEMPORARILY SATURATE THE DENDRITIC LAYER LEADING TO THE DEVELOPMENT OF SOME VERY LIGHT PRECIPITATION. AT THIS POINT...OBSERVATIONS ARE DRY UPSTREAM...BUT WILL HAVE TO KEEP A CLOSE EYE ON WORTHING TO SPIRIT LAKE AREA THIS MORNING. FAIR AMOUNT OF CLOUDS ARE EXPECTED TO STICK AROUND THE AREA AGAIN TONIGHT. AS SOUTHEASTERLY WINDS INCREASE FROM WEST TO EAST...EXPECT TEMPERATURES TO STEADY OUT...IF NOT RISE A DEGREE OR TWO. HAVE A SLIGHT NON-DIURNAL CURVE...ESPECIALLY ACROSS CENTRAL SOUTH DAKOTA. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 331 AM CST THU MAR 3 2016 AN EXTENDED WARMUP IS IN STORE FOR THE REGION AS WE MOVE INTO THE MEDIUM AND THROUGH THE EXTENDED PORTIONS OF THE FORECAST. A MODEST UPPER WAVE WILL TRACK THROUGH THE NORTHERN PLAINS FRIDAY. GENERALLY...MOISTURE WILL BE LIMITED WITH THIS WAVE...AND SHOULD KEEP ANY PRECIPITATION THROUGH THE FIRST HALF OF FRIDAY ON THE LIGHT SIDE. RAIN MAY BE THE PREDOMINATE PRECIPITATION FORM...BUT WOULD NOT RULE OUT A FEW SNOWFLAKES MIXING IN ESPECIALLY ALONG THE BUFFALO RIDGE AREA OF SW MINNESOTA. SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE AREA BY SATURDAY MORNING...SIGNALING A RETURN OF WARMER SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEKEND AND INTO NEXT WEEK. TEMPERATURES WILL BEGIN TO WARM ON SATURDAY...BUT LINGERING SNOW MAY KEEP READINGS DOWN A COUPLE DEGREES FROM THEIR POTENTIAL LEVELS. BY SUNDAY...GUSTY SOUTHWESTERLY WINDS SHOULD PUSH READINGS THROUGH THE 50S...WITH 60S POSSIBLE IN MANY AREAS. STRATUS REMAINS A CONCERN FOR SUNDAY...AND IT MAY HAMPER HIGHS JUST A BIT IF IT DEVELOPS AS ADVERTISED BY THE GFS. AN UPPER TROUGH LIFTING OUT OF THE FOUR CORNERS REGION OF THE US WILL AMPLIFY SOUTHWESTERLY FLOW IN THE LOWER LEVELS...BRINGING AN INCREASING RISK FOR LIGHT SHOWERS OR DRIZZLE BY MONDAY MORNING. INSTABILITY WILL BEGIN TO INCREASE AHEAD OF THIS UPPER TROUGH LATER ON MONDAY...AND WILL BRING AND INCREASING RISK FOR THUNDERSTORMS TO THE CWA BY MONDAY AFTERNOON AND EVENING. HIGHEST INSTABILITY LVLS REMAIN NEAR THE MO RIVER VALLEY...AND CAPPING LAYER REMAINS IN PLACE AS THE FRONT SLIDES INTO THE AREA...BUT GIVEN AMPLITUDE OF SHEAR...COULD NOT RULE OUT A STRONGER STORM OR TWO INTO MONDAY NIGHT. LOW-LVL TROUGH PASSAGE WILL OCCUR MONDAY NIGHT INTO TUESDAY MORNING...BUT SHOULD IT SLOW DOWN...A LINGERING RISK FOR A FEW THUNDERSTORMS WILL CONTINUE OVER NW IA AND SW MN TUESDAY MORNING. OTHERWISE...DEFORMATION PRECIPITATION AREA ON THE BACKSIDE OF THE ADVANCING TROUGH SHOULD BRING SHOWERS TO THE CWA ON TUESDAY. IF YOU ARE A FAN OF SPRING...THE OUTLOOK THROUGH NEXT WEEK REMAINS WARM. ABOVE NORMAL TEMPERATURES LOOK LIKELY THROUGH NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1144 AM CST THU MAR 3 2016 CEILINGS 1-3K FEET...EXCEPT THRU 04/00Z CEILINGS 3-5K FEET EAST AND NORTH OF A HON/FSD/SPW LINE. AFTER 04/00Z CEILINGS BECOMING 1-3K FEET ACROSS THE AREA. AREAS OF CEILINGS BELOW 1K FEET 04/06Z-16Z. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM...DUX AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
538 AM CST THU MAR 3 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 331 AM CST THU MAR 3 2016 DIFFICULT CLOUD FORECAST TODAY WITH A FAIR AMOUNT OF LOW LEVEL SATURATION ACROSS THE AREA. CURRENTLY HAVE A FAIR AMOUNT OF MID CLOUDS ACROSS SOUTHWEST MINNESOTA AND NORTHWEST IOWA...HOWEVER...FURTHER TO THE WEST...MUCH LOWER CLOUDS ARE DEVELOPING AS THE SURFACE FLOW BECOMES MORE NORTHERLY. MODEL SOUNDING SUGGEST A STRATUS LAYER WILL TRY TO DEVELOP AT THE TOP OF THE BOUNDARY LAYER TODAY. WITH RELATIVELY POOR MIXING CONDITIONS AND SIGNIFICANT CLOUD COVER...HAVE LOWERED FORECAST HIGHS TODAY. SHORT TERM HIGH RES MODELS INDICATE A FEW TRENDS ACROSS THE EASTERN EDGE OF THE AREA THAT NEED WATCHING. FIRST...BOTH THE HRRR AND THE RAP SUGGEST FOG DEVELOPING ACROSS NORTHWEST IOWA AND EXPANDING WESTWARD TOWARDS THE I-29 CORRIDOR. WITH FOG STARTING TO DEVELOP AT STORM LAKE CONFIDENCE IS GROWING WITH FOG AND WILL HAVE SOME PATCHY AND AREAS MENTIONED. OTHER CONCERN IS WITH A WEAK SHORTWAVE MOVING OUT OF NORTH DAKOTA INTO SOUTHWEST MINNESOTA. AS THIS WAVE PASSES THROUGH IN THE 12-15Z TIME FRAME...MODEL SOUNDINGS SUGGEST THAT SATURATION MAY GET DEEP ENOUGH TO TEMPORARILY SATURATE THE DENDRITIC LAYER LEADING TO THE DEVELOPMENT OF SOME VERY LIGHT PRECIPITATION. AT THIS POINT...OBSERVATIONS ARE DRY UPSTREAM...BUT WILL HAVE TO KEEP A CLOSE EYE ON WORTHING TO SPIRIT LAKE AREA THIS MORNING. FAIR AMOUNT OF CLOUDS ARE EXPECTED TO STICK AROUND THE AREA AGAIN TONIGHT. AS SOUTHEASTERLY WINDS INCREASE FROM WEST TO EAST...EXPECT TEMPERATURES TO STEADY OUT...IF NOT RISE A DEGREE OR TWO. HAVE A SLIGHT NON-DIURNAL CURVE...ESPECIALLY ACROSS CENTRAL SOUTH DAKOTA. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 331 AM CST THU MAR 3 2016 AN EXTENDED WARMUP IS IN STORE FOR THE REGION AS WE MOVE INTO THE MEDIUM AND THROUGH THE EXTENDED PORTIONS OF THE FORECAST. A MODEST UPPER WAVE WILL TRACK THROUGH THE NORTHERN PLAINS FRIDAY. GENERALLY...MOISTURE WILL BE LIMITED WITH THIS WAVE...AND SHOULD KEEP ANY PRECIPITATION THROUGH THE FIRST HALF OF FRIDAY ON THE LIGHT SIDE. RAIN MAY BE THE PREDOMINATE PRECIPITATION FORM...BUT WOULD NOT RULE OUT A FEW SNOWFLAKES MIXING IN ESPECIALLY ALONG THE BUFFALO RIDGE AREA OF SW MINNESOTA. SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE AREA BY SATURDAY MORNING...SIGNALING A RETURN OF WARMER SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEKEND AND INTO NEXT WEEK. TEMPERATURES WILL BEGIN TO WARM ON SATURDAY...BUT LINGERING SNOW MAY KEEP READINGS DOWN A COUPLE DEGREES FROM THEIR POTENTIAL LEVELS. BY SUNDAY...GUSTY SOUTHWESTERLY WINDS SHOULD PUSH READINGS THROUGH THE 50S...WITH 60S POSSIBLE IN MANY AREAS. STRATUS REMAINS A CONCERN FOR SUNDAY...AND IT MAY HAMPER HIGHS JUST A BIT IF IT DEVELOPS AS ADVERTISED BY THE GFS. AN UPPER TROUGH LIFTING OUT OF THE FOUR CORNERS REGION OF THE US WILL AMPLIFY SOUTHWESTERLY FLOW IN THE LOWER LEVELS...BRINGING AN INCREASING RISK FOR LIGHT SHOWERS OR DRIZZLE BY MONDAY MORNING. INSTABILITY WILL BEGIN TO INCREASE AHEAD OF THIS UPPER TROUGH LATER ON MONDAY...AND WILL BRING AND INCREASING RISK FOR THUNDERSTORMS TO THE CWA BY MONDAY AFTERNOON AND EVENING. HIGHEST INSTABILITY LVLS REMAIN NEAR THE MO RIVER VALLEY...AND CAPPING LAYER REMAINS IN PLACE AS THE FRONT SLIDES INTO THE AREA...BUT GIVEN AMPLITUDE OF SHEAR...COULD NOT RULE OUT A STRONGER STORM OR TWO INTO MONDAY NIGHT. LOW-LVL TROUGH PASSAGE WILL OCCUR MONDAY NIGHT INTO TUESDAY MORNING...BUT SHOULD IT SLOW DOWN...A LINGERING RISK FOR A FEW THUNDERSTORMS WILL CONTINUE OVER NW IA AND SW MN TUESDAY MORNING. OTHERWISE...DEFORMATION PRECIPITATION AREA ON THE BACKSIDE OF THE ADVANCING TROUGH SHOULD BRING SHOWERS TO THE CWA ON TUESDAY. IF YOU ARE A FAN OF SPRING...THE OUTLOOK THROUGH NEXT WEEK REMAINS WARM. ABOVE NORMAL TEMPERATURES LOOK LIKELY THROUGH NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 535 AM CST THU MAR 3 2016 AS THE FLOW BECOMES MORE NORTHERLY...LOWER CEILINGS ARE BUILDING INTO THE AREA AND HAVE WROTE A FAIRLY PESSIMISTIC SET OF TAFS. MODEL SOUNDINGS ALSO SUGGEST STRATUS DEVELOPING AND LINGERING THROUGHOUT THE DAY. AS WINDS GO LIGHT TONIGHT...EXPECT STRATUS TO REMAIN ACROSS THE AREA...POTENTIALLY LEADING TO CONDITIONS LOWER THAN IFR. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM...DUX AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
334 AM CST THU MAR 3 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 331 AM CST THU MAR 3 2016 DIFFICULT CLOUD FORECAST TODAY WITH A FAIR AMOUNT OF LOW LEVEL SATURATION ACROSS THE AREA. CURRENTLY HAVE A FAIR AMOUNT OF MID CLOUDS ACROSS SOUTHWEST MINNESOTA AND NORTHWEST IOWA...HOWEVER...FURTHER TO THE WEST...MUCH LOWER CLOUDS ARE DEVELOPING AS THE SURFACE FLOW BECOMES MORE NORTHERLY. MODEL SOUNDING SUGGEST A STRATUS LAYER WILL TRY TO DEVELOP AT THE TOP OF THE BOUNDARY LAYER TODAY. WITH RELATIVELY POOR MIXING CONDITIONS AND SIGNIFICANT CLOUD COVER...HAVE LOWERED FORECAST HIGHS TODAY. SHORT TERM HIGH RES MODELS INDICATE A FEW TRENDS ACROSS THE EASTERN EDGE OF THE AREA THAT NEED WATCHING. FIRST...BOTH THE HRRR AND THE RAP SUGGEST FOG DEVELOPING ACROSS NORTHWEST IOWA AND EXPANDING WESTWARD TOWARDS THE I-29 CORRIDOR. WITH FOG STARTING TO DEVELOP AT STORM LAKE CONFIDENCE IS GROWING WITH FOG AND WILL HAVE SOME PATCHY AND AREAS MENTIONED. OTHER CONCERN IS WITH A WEAK SHORTWAVE MOVING OUT OF NORTH DAKOTA INTO SOUTHWEST MINNESOTA. AS THIS WAVE PASSES THROUGH IN THE 12-15Z TIME FRAME...MODEL SOUNDINGS SUGGEST THAT SATURATION MAY GET DEEP ENOUGH TO TEMPORARILY SATURATE THE DENDRITIC LAYER LEADING TO THE DEVELOPMENT OF SOME VERY LIGHT PRECIPITATION. AT THIS POINT...OBSERVATIONS ARE DRY UPSTREAM...BUT WILL HAVE TO KEEP A CLOSE EYE ON WORTHING TO SPIRIT LAKE AREA THIS MORNING. FAIR AMOUNT OF CLOUDS ARE EXPECTED TO STICK AROUND THE AREA AGAIN TONIGHT. AS SOUTHEASTERLY WINDS INCREASE FROM WEST TO EAST...EXPECT TEMPERATURES TO STEADY OUT...IF NOT RISE A DEGREE OR TWO. HAVE A SLIGHT NON-DIURNAL CURVE...ESPECIALLY ACROSS CENTRAL SOUTH DAKOTA. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 331 AM CST THU MAR 3 2016 AN EXTENDED WARMUP IS IN STORE FOR THE REGION AS WE MOVE INTO THE MEDIUM AND THROUGH THE EXTENDED PORTIONS OF THE FORECAST. A MODEST UPPER WAVE WILL TRACK THROUGH THE NORTHERN PLAINS FRIDAY. GENERALLY...MOISTURE WILL BE LIMITED WITH THIS WAVE...AND SHOULD KEEP ANY PRECIPITATION THROUGH THE FIRST HALF OF FRIDAY ON THE LIGHT SIDE. RAIN MAY BE THE PREDOMINATE PRECIPITATION FORM...BUT WOULD NOT RULE OUT A FEW SNOWFLAKES MIXING IN ESPECIALLY ALONG THE BUFFALO RIDGE AREA OF SW MINNESOTA. SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE AREA BY SATURDAY MORNING...SIGNALING A RETURN OF WARMER SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEKEND AND INTO NEXT WEEK. TEMPERATURES WILL BEGIN TO WARM ON SATURDAY...BUT LINGERING SNOW MAY KEEP READINGS DOWN A COUPLE DEGREES FROM THEIR POTENTIAL LEVELS. BY SUNDAY...GUSTY SOUTHWESTERLY WINDS SHOULD PUSH READINGS THROUGH THE 50S...WITH 60S POSSIBLE IN MANY AREAS. STRATUS REMAINS A CONCERN FOR SUNDAY...AND IT MAY HAMPER HIGHS JUST A BIT IF IT DEVELOPS AS ADVERTISED BY THE GFS. AN UPPER TROUGH LIFTING OUT OF THE FOUR CORNERS REGION OF THE US WILL AMPLIFY SOUTHWESTERLY FLOW IN THE LOWER LEVELS...BRINGING AN INCREASING RISK FOR LIGHT SHOWERS OR DRIZZLE BY MONDAY MORNING. INSTABILITY WILL BEGIN TO INCREASE AHEAD OF THIS UPPER TROUGH LATER ON MONDAY...AND WILL BRING AND INCREASING RISK FOR THUNDERSTORMS TO THE CWA BY MONDAY AFTERNOON AND EVENING. HIGHEST INSTABILITY LVLS REMAIN NEAR THE MO RIVER VALLEY...AND CAPPING LAYER REMAINS IN PLACE AS THE FRONT SLIDES INTO THE AREA...BUT GIVEN AMPLITUDE OF SHEAR...COULD NOT RULE OUT A STRONGER STORM OR TWO INTO MONDAY NIGHT. LOW-LVL TROUGH PASSAGE WILL OCCUR MONDAY NIGHT INTO TUESDAY MORNING...BUT SHOULD IT SLOW DOWN...A LINGERING RISK FOR A FEW THUNDERSTORMS WILL CONTINUE OVER NW IA AND SW MN TUESDAY MORNING. OTHERWISE...DEFORMATION PRECIPITATION AREA ON THE BACKSIDE OF THE ADVANCING TROUGH SHOULD BRING SHOWERS TO THE CWA ON TUESDAY. IF YOU ARE A FAN OF SPRING...THE OUTLOOK THROUGH NEXT WEEK REMAINS WARM. ABOVE NORMAL TEMPERATURES LOOK LIKELY THROUGH NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1041 PM CST WED MAR 2 2016 THE 06Z TAF SET WILL REFLECT VFR CONDITIONS IN THE NEAR TERM. HOWEVER BEHIND A DEPARTING SHORT WAVE...WINDS OFF THE SURFACE WILL BECOME NORTHERLY WHICH SHOULD USHER IN SOME MVFR CEILINGS INTO THE AREA APPROACHING 12Z THURSDAY. CONFIDENCE IN THE TAFS CONTINUES TO BE LOW HOWEVER. FOR INSTANCE THE NAM AND RAP MODEL SOUNDINGS AND HUMIDITY TIME SECTIONS CONTINUE TO SHOW AN INUNDATION OF LOW STRATUS ACROSS THE ENTIRE AREA FOR THE REST OF TONIGHT AND THROUGH THURSDAY. THE PROBLEM IS...THOSE MODELS HAVE THESE CONDITIONS RIGHT NOW AND THEY ARE NOT OCCURRING. LOOKING BACK AT THE GFS ON TUESDAY...IT DID A BETTER JOB WITH THE CLOUD FORECAST FOR WEDNESDAY IN THAT IT WAS MORE OPTIMISTIC DURING THE AFTERNOON AND EVENING HOURS WEDNESDAY OF KEEPING THE IFR AND MVFR STRATUS AWAY FROM THIS AREA. THEREFORE RELIED HEAVILY ON THE GFS FOR THE REST OF TONIGHT AND THURSDAY...AND IT IS SUGGESTING MORE OF AN MVFR ENVIRONMENT...BRINGING DOWN SOME MVFR CEILINGS CURRENTLY IN NORTH DAKOTA INTO THIS AREA. AGAIN...TIMING OF THE ARRIVAL OF MVFR CONDITIONS IS QUESTIONABLE. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM...DUX AVIATION...MJ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1046 PM CST WED MAR 2 2016 .UPDATE... ISSUED AT 853 PM CST WED MAR 2 2016 THE ORGANIZED AREA OF PRECIPITATION THAT WAS IN SOUTHWEST SD IS DIVING SOUTHEASTWARD AT THIS POINT INTO NEBRASKA. THAT WAS EXPECTED. THE NORTHERN BRANCH IN NORTH DAKOTA IS WEAKENING AS IT TRIES TO MOVE SOUTHEASTWARD. ALL THAT IS LEFT IS A BAND OF MID LEVEL MOISTURE IN OUR WESTERN ZONES THAT IS ALSO MOVING SOUTHEASTWARD. AND IT IS LIKELY MOST OF THAT IS NOT REACHING THE GROUND. THEREFORE ONLY SKITTISH POPS FOR LIGHT SNOW SHOWERS ARE WARRANTED FOR THE REST OF TONIGHT...AND ITS DOUBTFUL WHETHER ANY SNOWFALL WOULD ACTUALLY MEASURE. THEREFORE WILL KEEP THE POPS LOW. LASTLY...WILL ELIMINATE THE CHANCE FOR SCATTERED FLURRIES FOR OUR EASTERN ZONES THURSDAY MORNING. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 300 PM CST WED MAR 2 2016 MAIN WAVE NOW APPEARS TO MOVE SOUTHEAST OFF THE SOUTHWEST CORNER OF THE AREA TONIGHT. SOME UPPER SUPPORT APPEARS TO SPREAD TO THE EAST OVER THE MISSOURI RIVER AREA BUT ALL MODELS ARE DEPICTING PRECIPITATION BECOMING ORGANIZED EAST OF THE AREA. EXPECT PRECIPITATION TONIGHT TO BE SCATTERED AND QUITE LIGHT...INCLUDING SOUTHWEST MINNESOTA WHERE BEFORE WE WERE GOING WITH LIKELY POPS. TEMPERATURES ALOFT APPEAR COOLER FOR TONIGHT THAT WE WERE LOOKING AT YESTERDAY...SO DESPITE THE VERY LIGHT NATURE OF THE PRECIPITATION AND THE RESULTING MINIMAL EVAPORATIONAL COOLING...SEE A VERY MINIMAL FREEZING RAIN CHANCE WHERE COOLING IS FAST ENOUGH OVER THE SOUTHWEST HALF OF THE AREA EARLY THIS EVENING. OTHERWISE SOME LIGHT RAIN SOUTHWEST EARLY OTHERWISE PRECIPITATION...IF ANY...SHOULD BE MOSTLY LIGHT SNOW. ACCUMULATIONS WILL STAY BELOW A HALF INCH. AS THE UPPER WAVE PASSES A LOW LEVEL FLOW OF COOL AND MOIST AIR SHOULD ASSURE A LOT OF LOW STRATUS OVER THE AREA ESPECIALLY NORTH AND EAST. THIS SHOULD DEVELOP STRONGLY LATER TONIGHT AND BE STUBBORN ABOUT DISSIPATING THURSDAY. AM ALLOWING FOR THE START OF BREAKING UP BY THURSDAY AFTERNOON BUT EXPECT SKIES TO BE MOSTLY CLOUDY AT BEST. TEMPERATURES WILL COOL INTO THE 20S TONIGHT AND WARM TO THE 30S THURSDAY...EXCEPT 40 PLUS FAR SOUTHWEST. NOT A LOT OF DIURNAL RANGE WITH ALL THE CLOUDS. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 300 PM CST WED MAR 2 2016 THURSDAY NIGHT INTO FRIDAY WILL SEE A WAVE APPROACH FROM THE NORTHWEST BUT WILL STRUGGLE TO PRODUCE TOO MUCH IN THE WAY OF PRECIPITATION DUE TO A LACK OF LOW LEVEL MOISTURE. WILL HAVE LOW END CHANCE POPS IN PLACE ACROSS HIGHWAY 14 INTO SOUTHWEST MINNESOTA WITH SMALLER CHANCES TO THE SOUTHWEST. THE BETTER CHANCES SHOULD BE LATE FRIDAY MORNING THROUGH THE AFTERNOON AND SHOULD MAINLY BE IN THE FORM OF LIGHT RAIN. WITH A VERY GRADUALLY INCREASING SOUTHERLY FLOW AND CLOUD COVER LOWS WILL NOT BE TOO COLD AND SHOULD BE MAINLY MID TO UPPER 20S. AS THE WAVE MOVES THROUGH CLOUDS WILL DECREASE FROM THE WEST AND ALLOW FOR SOME DECENT WARMING. THIS SHOULD BE A BIG MELTING DAY FOR AREAS WEST OF INTERSTATE 29...AS HIGHS CLIMB INTO THE MID TO UPPER 40S ALONG THE JAMES RIVER VALLEY AND TO 50 TO 55 INTO SOUTH CENTRAL SD. A SHOT OF COOL AIR WILL SPREAD SOUTH FRIDAY NIGHT AND AT THIS TIME APPEARS TO BE A BIT OVERDONE ON THE GFS COMPARED TO OTHER MODELS. SO AT THIS TIME WILL LEAN TOWARDS MID TO UPPER 20S FOR LOWS. SATURDAY LOOKS TO BE A VERY NICE DAY AS HIGH PRESSURE MOVES THROUGH AND SOUTHERLY FLOW STARTS TO DEVELOP. TO EASTERN CWA WILL STILL HAVE SOME SNOW TO GET RID OF SO WILL KEEP HIGHS TEMPERED BACK A BIT THERE...BUT ALLOW FOR 50S ALONG AND WEST OF THE JAMES RIVER VALLEY. IN THE OUTER PERIODS...SUNDAY THROUGH WEDNESDAY...A SIGNIFICANT CHANGE IN PATTERN IS STILL EXPECTED AS RIDGING ALOFT GRADUALLY SHIFTS EAST WHILE A TROUGH DEEPENS OVER THE WESTERN THIRD OF THE UNITED STATES. THIS WILL BRING MUCH MORE MOIST AIR IN THE LOW LEVELS THAN HAS BEEN SEEN FOR QUITE AWHILE ALONG WITH A SUSTAINED SOUTHERLY FLOW FROM ABOUT SUNDAY INTO TUESDAY. TEMPERATURES WILL BE WELL ABOVE NORMAL...ESPECIALLY WITH REGARDS TO LOWS...AND A FEW WARM LOW TEMPERATURE RECORDS ARE LIKELY TO FALL. THE BEST CHANCE FOR THIS WILL BE MONDAY MORNING AND TUESDAY MORNING. ALONG WITH THE INCREASED WARMING AND MOISTURE IN THE LOW LEVELS WILL BE A THREAT FOR A FEW THUNDERSTORMS. AT THIS TIME THE BETTER CHANCE FOR THIS LOOKS TO BE MONDAY NIGHT BUT IF THE SYSTEM IS SLOW ENOUGH EXITING ON TUESDAY THE EASTERN THIRD OF THE CWA...MAINLY SW MINNESOTA AND NW IOWA...WOULD SEE AN ADDITIONAL THREAT. NOT OUT OF THE QUESTION TO SEE A FEW SEVERE STORMS NEAR THE MISSOURI RIVER MONDAY NIGHT BUT THE BETTER CHANCE WILL BE TO THE SOUTH. WHILE EVERYTHING WOULD NEED TO COME TOGETHER JUST RIGHT...DUE TO THE POTENTIAL FOR A LOT OF LOW TO MID LEVEL SHEAR A FEW SEVERE THUNDERSTORMS WOULD ALSO BE POSSIBLE TUESDAY AFTERNOON...BUT AT THIS TIME THAT THREAT APPEARS TO BE EAST OF THIS AREA. COOLER WEATHER WILL SETTLE BACK INTO THE AREA WEDNESDAY BUT STILL MILD FOR EARLY MARCH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1041 PM CST WED MAR 2 2016 THE 06Z TAF SET WILL REFLECT VFR CONDITIONS IN THE NEAR TERM. HOWEVER BEHIND A DEPARTING SHORT WAVE...WINDS OFF THE SURFACE WILL BECOME NORTHERLY WHICH SHOULD USHER IN SOME MVFR CEILINGS INTO THE AREA APPROACHING 12Z THURSDAY. CONFIDENCE IN THE TAFS CONTINUES TO BE LOW HOWEVER. FOR INSTANCE THE NAM AND RAP MODEL SOUNDINGS AND HUMIDITY TIME SECTIONS CONTINUE TO SHOW AN INUNDATION OF LOW STRATUS ACROSS THE ENTIRE AREA FOR THE REST OF TONIGHT AND THROUGH THURSDAY. THE PROBLEM IS...THOSE MODELS HAVE THESE CONDITIONS RIGHT NOW AND THEY ARE NOT OCCURRING. LOOKING BACK AT THE GFS ON TUESDAY...IT DID A BETTER JOB WITH THE CLOUD FORECAST FOR WEDNESDAY IN THAT IT WAS MORE OPTIMISTIC DURING THE AFTERNOON AND EVENING HOURS WEDNESDAY OF KEEPING THE IFR AND MVFR STRATUS AWAY FROM THIS AREA. THEREFORE RELIED HEAVILY ON THE GFS FOR THE REST OF TONIGHT AND THURSDAY...AND IT IS SUGGESTING MORE OF AN MVFR ENVIRONMENT...BRINGING DOWN SOME MVFR CEILINGS CURRENTLY IN NORTH DAKOTA INTO THIS AREA. AGAIN...TIMING OF THE ARRIVAL OF MVFR CONDITIONS IS QUESTIONABLE. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...MJ SHORT TERM... LONG TERM...08 AVIATION...MJ
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
351 PM EST THU MAR 3 2016 .SYNOPSIS... LOW PRESSURE WILL MOVE QUICKLY TRACK FROM THE MISSISSIPPI VALLEY TONIGHT...TO THE COAST OF NORTH CAROLINA FRIDAY MORNING. FOLLOWING A BRIEF PERIOD OF HIGH PRESSURE FRIDAY NIGHT...ANOTHER LOW WILL MOVE FROM THE NORTHERN PLAINS TO THE MID ATLANTIC REGION BY SUNDAY. A LARGE HIGH WILL COVER THE REGION ON MONDAY. && .NEAR TERM /THROUGH FRIDAY/... AS OF 340 PM EST THURSDAY... WINTER WEATHER ADVISORY WAS IN EFFECT FOR A LARGE PART OF THE FORECAST AREA. SOIL TEMPERATURES RANGED FROM THE MID 30S IN THE NORTHWEST COUNTY WARNING AREA TO THE MID 40S IN THE SOUTHEAST COUNTY WARNING AREA...WITH THE EXCEPTING OF UPPER 20S IN THE NORTHWEST NORTH CAROLINA MOUNTAINS. A FEW OTHER FACTORS WILL INFLUENCE SNOW AMOUNTS TOO. AS LOWER LEVELS SATURATE TEMPERATURES WILL COME DOWN AND DEW POINTS WILL COME UP. FOLLOWED THIS NON DIURNAL TREND TO ESTABLISH MINIMUM TEMPERATURES TONIGHT. BUFKIT FORECAST SOUNDING SUPPORTED SNOW FORMATION AT UPPER LEVELS BUT SURFACE AND NEAR SURFACE WET BULB TEMPERATURES ALONG AND EAST OF THE BLUE RIDGE WERE AT OR SLIGHTLY ABOVE FREEZING FOR A FEW HOURS OVERNIGHT. THIS WILL LIMIT SNOW ACCUMULATION IN THE EAST. THE EXCEPTION IS A BAND OF HIGHER QPF POTENTIAL FROM CHARLOTTE COUNTY VIRGINIA TO ROCKINGHAM COUNTY NORTH CAROLINA WHERE QPF WILL BE LOCALLY ENHANCED AND THE DEEPENING LOW MAY PROVIDE ENOUGH LIFT SNOWFALL RATES TO OVERCOME MELTING. CONFIDENCE IS ONLY MODERATE WITH THIS OUTCOME. WINDS AT LOWER LEVEL BACK TO THE SOUTH AHEAD OF THE LOW BUT DO NOT HAVE A GOOD SOUTHEAST COMPONENT BEFORE THE MAIN LOW BEGINS TO DEEPEN RAPIDLY OFF OF THE OUTER BANKS. HRRR AND LOCAL WRF ARE SIMILAR WITH THE LOCATION AND TIMING OF THE PRECIPITATION. THESE MODELS BRING ONE BATCH OF SNOW ACROSS THE NORTHERN HALF OF THE COUNTY WARNING AREA LATE THIS AFTERNOON INTO EARLY THIS EVENING...WITH PRECIPITATION FILLING IN ACROSS THE SOUTHERN COUNTY WARNING AREA A FEW HOURS LATER...THEN SHOWING AN AXIS OF POTENTIALLY HEAVIER SNOW FROM CHARLOTTE COUNTY VIRGINIA TO ROCKINGHAM COUNTY NORTH CAROLINA LATE TONIGHT. IN GENERAL WILL FOLLOW THIS TIMING AND PLACEMENT THROUGH FRIDAY MORNING. BASED ON THE EXPECTED LIQUID EQUIVALENT AMOUNTS...SNOWFALL AMOUNTS SUPPORT AN ADVISORY BUT NOT A WARNING. SNOW WILL IMPACT THE EVENING COMMUTE IN MOUNTAIN LOCATIONS AND BASED ON THE TIMING...FAR EASTERN COUNTIES OF THE FORECAST AREA MAY STILL BE GETTING SNOW DURING FRIDAY MORNINGS PEAK TRAVEL TIME. BY FRIDAY AFTERNOON COLD UPPER TROF AND COLD AIR ALOFT ARE WELL EAST OF THE FORECAST AREA WITH 500 MB HEIGHTS ALREADY BEGINNING TO RISE. UPPER JET ROUNDS BASE OF THE TROF THEN INTENSIFIES RESULTING IN SOME STRONGER LIFT OVER EASTERN VIRGINIA AND NORTH CAROLINA OVERNIGHT. WILL HAVE SOME CLEARING AND SUN DURING THE AFTERNOON...ESPECIALLY IN THE EAST ON FRIDAY. THIS WILL MEAN TEMPERATURES WILL BE CLOSE TO MAV VALUES FOR MAXIMUM TEMPERATURES. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... AS OF 315 PM EST THURSDAY... THE DEEPENING CLIPPER SYSTEM SHOULD DEPART OFFSHORE ON FRIDAY NIGHT...AND ALLOW ANY UPSLOPE MOISTURE OVER SOUTHEAST WEST VIRGINIA TO SUBSIDE. CLOUDS WILL REMAIN PREVALENT AS ONE MORE CLIPPER SYSTEM APPROACHES FROM THE GREAT LAKES ON SATURDAY. THE MODELS PIN ITS ARRIVAL WITHIN THE AFTERNOON HOURS. IT APPEARS CONSIDERABLY WEAK WITH JUST A 1016 MB LOW. THE 12Z GFS KEEPS MOST OF THE MOISTURE CONFINED TO AREAS WEST OF THE BLUE RIDGE...WHERE THE HIGHEST POPS WERE KEPT IN THIS UPDATE. LIGHT RAIN SHOWERS SHOULD CHANGE TO SNOW SHOWERS BY SATURDAY NIGHT WITH LITTLE IF ANY ACCUMULATION. BREEZY NORTHWEST WINDS ARE POSSIBLE FOR SATURDAY NIGHT INTO SUNDAY MORNING...AS THE CLIPPER SYSTEM HEADS EAST OF THE CWA. THE HIGHER RIDGETOPS MAY GUST UP TO 30 MPH...BUT IT APPEARS THAT NO HEADLINES FOR WIND WILL BE NEEDED DUE TO WEAK COLD AIR ADVECTION AND MINIMAL PRESSURE RISES BEHIND THIS SYSTEM. AS IT DEPARTS OFFSHORE ON SUNDAY...HIGH PRESSURE SHOULD BUILD OVER THE MID ATLANTIC. IT MAY TAKE UNTIL LATER IN THE DAY FOR SKIES TO FINALLY CLEAR ALONG THE FAR WESTERN PORTIONS OF THE CWA. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 330 PM EST WEDNESDAY... BY MONDAY...IT WILL SEEM LIKE THE ATMOSPHERE FLIPPED A SWITCH FROM WINTER TO SPRING. SURFACE HIGH PRESSURE SHOULD ANCHOR ALONG THE EAST COAST...WHILE 500 MB HEIGHTS BUILD TOWARD 580 DAM OVERHEAD. THESE FACTORS WILL START A NOTEWORTHY WARMING TREND. HIGHS FOR WEDNESDAY AND THURSDAY COULD EASILY REACH THE 60S AND 70S. MEANWHILE...A LOW PRESSURE SYSTEM WILL ORGANIZE OVER THE CENTRAL PLAINS IN ASSOCIATION WITH AN UPPER LEVEL TROUGH MOVING TOWARD TEXAS. THIS TROUGH IS PROJECTED TO BECOME A CUT OFF LOW...BUT ITS FORWARD PROGRESS WILL BE SLOWED BY THE UPPER LEVEL RIDGE OVER FLORIDA. EVENTUALLY...THE WARM FRONT FROM THE LOW PRESSURE SYSTEM MAY REACH THE MID ATLANTIC TO SPARK A CHANCE OF SHOWERS LATER IN THE WORK WEEK. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... AS OF 1235 PM EST THURSDAY... LOW PRESSURE SYSTEM TRACKING FROM THE MIDDLE AND LOWER MISSISSIPPI VALLEY TO THE COAST OF NORTH CAROLINA BY FRIDAY MORNING WILL SPREAD SNOW INTO THE AREA TONIGHT. MEDIUM TO HIGH CONFIDENCE ON TIMING WITH A GOOD CONSENSUS IN THE MODELS THAT SNOW WILL BEGIN AT KBLF/KLWB/KBCB/KROA/KLYH 20Z/3PM AND 00Z/7PM. RAIN OR A MIX OF RAIN AND SNOW WILL BEGIN AT KDAN AROUND 00Z/7PM. LOWER CONFIDENCE IN THE AMOUNT OF SNOW. WITH THE SNOW...CEILINGS AND VISIBILITIES WILL BE IFR TO LIFR OVERNIGHT. ONCE THE LOW MOVES TO THE EAST...WINDS WILL BECOME NORTHWEST. SNOW WILL END IN THE EAST AFTER 09Z/4AM BUT SNOW SHOWERS WILL PERSIST AT KLWB AND KBLF THROUGH MUCH OF FRIDAY. HIGH CONFIDENCE THERE WILL BE LITTLE IMPROVEMENT IN CEILINGS AT THOSE SITES. CEILINGS WILL LIFT TO VFR WITH BREAKS IN THE CLOUD COVER BY AFTERNOON EAST OF THE BLUE RIDGE. EXTENDED DISCUSSION... FRIDAY NIGHT WILL BE A BRIEF WINDOW OF VFR BEFORE ANOTHER FAST MOVING CLIPPER SYSTEM PASSES JUST NORTH OF THE REGION SATURDAY PROVIDING ANOTHER ROUND OF MVFR AND POSSIBLE LIGHT PRECIPITATION TO THE MOUNTAINS. HIGH PRESSURE BUILDS OVERHEAD WITH VFR CONDITIONS SUNDAY THROUGH TUESDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR VAZ007- 009>020-022>024-032>035-043>047-058-059. NC...WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR NCZ001>004- 018-019. WV...WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR WVZ042>044- 507-508. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...PW LONG TERM...PW AVIATION...AMS/KK
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
730 PM PST FRI MAR 4 2016 .SYNOPSIS...THE COLD FRONT THAT IS CURRENTLY BRINGING RAIN TO THE COAST WILL PUSH INLAND THIS EVENING SPREADING RAIN TO THE REST OF NORTHWEST OREGON AND SOUTHWEST WASHINGTON. SURFACE LOW PRESSURE MOVING UP THE COAST WILL ALSO BRING A PERIOD OF STRONG WINDS TO THE COAST LATE FRIDAY EVENING AND OVERNIGHT. ANOTHER DEVELOPING LOW PRESSURE SYSTEM WILL LIKELY BRING MORE RAIN TO THE REGION SATURDAY AND POSSIBLY STRONG WINDS...PARTICULARLY TO THE COAST AGAIN. SNOW LEVELS WILL LIKELY DROP TO THE CASCADE PASSES SATURDAY NIGHT FOR A FEW INCHES OF ACCUMULATION BY SUNDAY MORNING. SHOWERS CONTINUE THROUGH MONDAY WITH POSSIBLY AN AFTERNOON THUNDERSTORM OR TWO. ADDITIONAL WET WEATHER WILL LIKELY ARRIVE TOWARDS THE MIDDLE TO LATTER HALF OF NEXT WEEK. && .EARLY UPDATE...RELEASED A QUICK UPDATE TO THE FORECAST FOR TONIGHT...ACCOUNTING FOR THE SLOWER INLAND PROGRESSION OF THE RAIN. INLAND VALLEYS AND CASCADES MAY SEE A COUPLE SPRINKLES OR AREAS OF LIGHT RAIN...BUT MOST OF THE EVENING SHOULD STAY DRY EAST OF THE COAST RANGE. THE SAME FEATURE DELAYING THE RAIN INLAND IS ALSO DELAYING THE WIND ALONG THE COAST...A WEAK WAVE OF LOW PRESSURE HAS DEVELOPED ALONG THE FRONT NEAR 39N/127W. WITH THIS SYSTEM HEADED TOWARD NORTHERN CA AND ROBBING SOME OF THE SOUTHERLY FLOW...AM BECOMING INCREASINGLY SKEPTICAL THAT THE HIGH WIND WARNING WILL VERIFY ALONG THE COAST. HOWEVER...WILL LET THE WARNING RIDE FOR THE TIME BEING AND WILL TAKE A CLOSER LOOK BEFORE THE REGULARLY SCHEDULED EVENING PACKAGE GOES OUT. WEAGLE /PREV DISC ISSUED 322 PM FRI MAR 4 2016/ .SHORT TERM...TONIGHT THROUGH MONDAY...A LARGE LOW PRESSURE AREA COVERING THE GULF OF ALASKA WILL SEND MULTIPLE SECONDARY LOWS AND ASSOCIATED FRONTAL SYSTEMS ACROSS THE REGION OVER THE NEXT FEW DAYS. A COLD FRONT WILL BRING MORE RAIN TO THE COAST THIS AFTERNOON BEFORE SPREADING INLAND THIS EVENING. KRTX AND KLGX RADARS CONTINUE TO SHOW SOME LIGHT RAIN OVER MAINLY THE NORTH COAST THIS AFTERNOON WITH KAST MEASURING 0.05 INCHES IN THE LAST HOURS. MEANWHILE...SATELLITE IMAGERY CONTINUES TO REVEAL A DEVELOPING SURFACE LOW MOVING NORTH OVER THE SOUTHERN OREGON OFFSHORE WATERS NEAR 125 W. THIS LOW HELPED STALL THE COLD FRONT THIS MORNING...BUT AS IT CONTINUES TO MOVE NORTH THIS EVENING THE FRONT WILL PUSH INLAND. THE 12Z OPERATIONAL MODELS AND THE 18Z NAM CONTINUES TO SHOW THE LOW BOTTOMING OUT NEAR 995 MB AS IT PASSES JUST WEST OF THE NORTHERN OREGON AND SOUTHERN WASHINGTON WATERS LATER THIS EVENING. MODELS CONTINUE TO SHOW THE PRESSURE GRADIENT OPENING UP LATER THIS EVENING WHICH WILL BRING A SURGE OF HIGH WINDS TO THE MAINLY THE BEACHES AND HEADLANDS AROUND 10 PM TONIGHT...WITH GUSTS TO 65 MPH LIKELY. WINDS LOOK TO QUICKLY FALL BELOW 50 MPH SHORTLY AFTER MIDNIGHT TONIGHT AS THE LOW CONTINUES TO PUSH NORTH AND WEAKEN BEFORE MAKING LANDFALL OVER BRITISH COLUMBIA. WILL MAINTAIN THE HIGH WIND WARNING AS IS...BUT WE MAY BE ABLE TO DROP IT BY 2 AM SATURDAY. WILL SEE A BRIEF PERIOD OF POST FRONTAL SHOWERS DEVELOP WEST OF THE COAST RANGE LATE TONIGHT AHEAD OF ANOTHER SERIES OF FRONTAL SYSTEMS THAT WILL IMPACT THE REGION ON SATURDAY. THIS SYSTEM LOOKS TO FOLLOW A SIMILAR EVOLUTION TO TODAY`S SYSTEM...ALBEIT WITH A MUCH MORE COMPLICATED SURFACE PATTERN. WARM FRONTAL RAIN LOOKS TO RETURN TO THE COAST EARLY SATURDAY AFTERNOON...WITH RAIN SPREADING INLAND IN THE EVENING. WITH SUCH A SHORT BREAK BETWEEN SYSTEMS SNOW LEVELS LOOK TO GENERALLY REMAIN ABOVE 6000 FT THROUGH MUCH OF SATURDAY. WITH REGARDS TO THE COMPLICATED SURFACE PATTERN...MODELS CONTINUE TO SHOW TWO SECONDARY LOWS DEVELOPING SATURDAY MORNING OVER THE NORTHERN CALIFORNIA WATERS NEAR 130 W. BOTH LOWS LOOK TO DEEPEN TO AROUND 975 MB AS THEY MOVE NORTH STRADDLING 130 W. DESPITE THE LOW REMAINING FURTHER OFFSHORE THAT TODAY`S SYSTEM WE COULD STILL SEE A PERIOD OF HIGH WINDS ALONG THE COAST AND BREEZY CONDITIONS INLAND. WILL GO AHEAD AND ISSUE A HIGH WIND WATCH FOR THE COAST...WITH GUSTS TO 60 MPH POSSIBLE SATURDAY AFTERNOON THROUGH EARLY SUNDAY MORNING. SNOW LEVELS WILL FINALLY FALL BELOW PASS LEVEL LATE SATURDAY AS THE COLD FRONT PUSHES EAST OF THE CASCADES. THE AFOREMENTIONED LARGE LOW PRESSURE AREA FINALLY MOVES ONSHORE ON SUNDAY...WITH THE BASE OF THE TROUGH PASSING OVER THE PACIFIC NORTHWEST. THIS WILL HELP SUPPORT SHOWERS ACROSS THE FORECAST AREAS SUNDAY AND MONDAY. COULD ALSO SEE A PERIOD OF THUNDERSTORMS ON SUNDAY AS THE COLD CORE DRIFTS OVER THE FORECAST AREA. THIS COLD CORE WILL ALSO ALLOW SNOW LEVELS TO FALL TO AROUND 3000 FT BY SUNDAY EVENING...WITH 3 TO 6 INCHES OF NEW SNOW POSSIBLE IN THE CASCADES SUNDAY AND MONDAY. /64 .LONG TERM...MONDAY NIGHT THROUGH FRIDAY...AN UPPER LEVEL TROUGH AND ONSHORE FLOW WILL CONTINUE SHOWERS MONDAY NIGHT. TUESDAY MORNING WILL BE BETWEEN SYSTEMS WITH SHOWERS RAPIDLY DECREASING UNDER BRIEF RIDGING. THE NEXT PACIFIC FRONT WILL BRING A RETURN OF RAIN AND MOUNTAIN SNOW TUESDAY AFTERNOON WITH SNOW LEVELS AROUND 3500 FEET. THERE IS POTENTIAL FOR AN ATMOSPHERIC RIVER EVENT WEDNESDAY AND THURSDAY WITH A SURFACE LOW (AND ASSOCIATED FRONT) TAPPING INTO A SWATH OF 1.10 TO 1.4 INCHES OF PRECIPITABLE WATER. INTEGRATIVE VAPOR TRANSPORT SHOWS THE BEST CHANCE FOR HEAVY RAIN ACROSS SW OREGON...BUT THINK NW OREGON AND SW WASHINGTON CAN STILL GET A DECENT SOAKING. SNOW LEVELS WILL INITIALLY START AROUND 3500 FEET TUESDAY NIGHT...THEN RAPIDLY RISE TO AROUND 5500 FEET WEDNESDAY. TJ && .AVIATION...SOME SHOWERS ALONG THE COAST THIS AFTERNOON BUT THE ENTIRE AREA IS VFR. COULD START TO SEE SOME MVFR ALONG THE COAST WITH STEADIER RAIN AROUND 00Z...PUSHING INTO THE VALLEY BY AROUND 03Z. VFR RETURNS AFTER 10Z AT THE COAST AND AFTER ABOUT 12Z OR 13Z INLAND AS RAIN MOVES OUT OF THE AREA. WINDS ALONG THE COAST WILL PICK UP THIS EVENING OUT OF THE SOUTH...DROPPING OFF EARLY SATURDAY MORNING. KPDX AND APPROACHES...VFR WITH HIGH CLOUDS. WILL SEE CIGS LOWER TO NEAR 5000 FT THIS EVENING...WITH LIGHT RAIN AND POTENTIAL FOR MVFR CONDITIONS INCREASING AFTER 03Z. WINDS GUSTY OUT OF THE EAST ON EASTERN APPROACHES. BOWEN && .MARINE...WINDS AND SEAS HAVE DROPPED OFF SLIGHTLY THIS AFTERNOON AS A COLD FRONT HAS STALLED ACROSS THE MARINE WATERS. LOW PRESSURE WELL OFF THE SW OREGON COAST WILL PUSH TOWARD THE LOCAL WATERS THROUGH THE EVENING AND HELP TO PUSH THE FRONT ONSHORE WHILE INCREASING WINDS AND SEAS AGAIN. SEAS WILL PUSH 25 FT LATE THIS AFTERNOON AND EVENING WITH WINDS OUT OF THE SOUTH AT AROUND 40 KT WITH GUSTS ABOVE 50 KT. ONCE THE FRONT MOVES ONSHORE AND THE LOW PASSES BY...WINDS WILL SHIFT SW AND EASE...WITH SEAS DROPPING BACK INTO THE MID TEENS SATURDAY MORNING. A VERY SIMILAR SITUATION LOOKS LIKE IT IS SETTING UP FOR SATURDAY AFTERNOON AND EVENING WITH ANOTHER LOW PRESSURE SYSTEM MOVING UP THE COAST FROM THE SOUTHWEST. THIS IS A A STRONGER LOW BUT STAYS SLIGHTLY FARTHER OUT SO WINDS AND SEAS WILL LIKELY BE JUST A BIT LESS THAN WITH THE SYSTEM TODAY. HOWEVER THERE IS STILL THE POTENTIAL FOR SOME STORM GUSTS SO HAVE ISSUED A STORM WATCH FOR THE WATERS OFF THE COAST OF CENTRAL OREGON. ALSO ISSUED A GALE WATCH FOR THE WATERS OFF THE N OREGON AND S WASHINGTON COASTS FOR THE SAME TIME PERIOD LATE SATURDAY AFTERNOON AND EVENING. CONFIDENCE IS MODERATE FOR THIS SYSTEM...SO WILL BE KEEPING A CLOSE EYE ON ITS DEVELOPMENT OVER THE NEXT 24 HOURS. THE REST OF THE FORECAST PERIOD LOOKS ACTIVE WITH PERIODS OF GALES AND SEAS REMAINING IN THE TEENS. HOWEVER THERE IS NOTHING IN THE REST OF THE 5-DAY FORECAST THAT LOOKS AS STRONG AND THIS EVENING`S AND TOMORROW EVENING`S SYSTEMS. BOWEN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...HIGH WIND WARNING FROM 9 PM THIS EVENING TO 4 AM PST SATURDAY FOR CENTRAL OREGON COAST-NORTH OREGON COAST. HIGH SURF ADVISORY UNTIL 3 AM PST SATURDAY FOR CENTRAL OREGON COAST-NORTH OREGON COAST. HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY NIGHT FOR CENTRAL OREGON COAST-NORTH OREGON COAST. WA...HIGH WIND WARNING FROM 9 PM THIS EVENING TO 4 AM PST SATURDAY FOR SOUTH WASHINGTON COAST. HIGH SURF ADVISORY UNTIL 3 AM PST SATURDAY FOR SOUTH WASHINGTON COAST. HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY NIGHT FOR SOUTH WASHINGTON COAST. PZ...GALE WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. STORM WARNING FROM 6 PM THIS EVENING TO 1 AM PST SATURDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. GALE WARNING UNTIL 6 PM PST THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. STORM WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM PST SATURDAY. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
  [top] Area Forecast Discussion National Weather Service Spokane WA 715 PM PST FRI MAR 4 2016 .SYNOPSIS... A series of weather disturbances are expected this weekend. These storms will result in significant rain and mountain snow. Cooler temperatures with lingering showers will persist Monday and Tuesday. A very wet pattern looks to then set up toward the end of next week. && .DISCUSSION... Updated the forecast to increase pops for tonight as the short term models like the RUC are trending wetter and bringing in some of the rain a bit earlier overnight. /Pelatti && .AVIATION... 00Z TAFs: VFR cigs/vsby will prevail through 12z Saturday. The next in a series of weather systems will bring increasing moisture to the region after 03z tonight with -ra possible at KEAT after 09z spreading to the region and Taf locations by 15Z. Stratiform rain is expected to linger in the region through the end of the TAF period. /JDC && .PRELIMINARY POINT TEMPS/POPS... Spokane 43 53 45 51 34 48 / 60 80 100 90 20 40 Coeur d`Alene 41 54 43 50 34 49 / 60 80 100 100 30 40 Pullman 43 54 45 50 36 48 / 60 80 90 90 20 50 Lewiston 46 58 48 55 39 53 / 60 60 80 80 40 40 Colville 38 53 43 54 32 50 / 50 60 100 100 30 40 Sandpoint 37 49 41 48 33 47 / 40 90 100 100 40 40 Kellogg 38 49 41 44 31 45 / 60 80 90 100 20 50 Moses Lake 42 58 46 58 34 52 / 50 40 100 20 20 30 Wenatchee 39 53 40 55 34 49 / 60 50 100 20 20 40 Omak 38 51 42 52 32 48 / 80 20 100 60 30 40 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
242 AM CST SAT MAR 5 2016 .SHORT TERM...(Today) ISSUED AT 241 AM CST SAT MAR 5 2016 Patchy fog will affect central Illinois ahead of an advancing cold front early this morning. The fog will clear by mid-morning as cold front departs into Indiana by 11 am. Little to no precipitation is expected with the frontal passage in central Illinois, except for possibly a few sprinkles in areas northeast of Champaign to Danville. Winds will shift from southwest to northwest behind the front, and become breezy with gusts to 25 mph at times later this morning and this afternoon. The latest HRRR and RAP guidance are pointing towards enough residual low level moisture behind the front for mostly cloudy skies to linger through at least mid-afternoon. Breaks will eventually develop in the cloud layer due to turbulent mixing of dry mid-level air toward the surface. Areas southwest of Springfield to Mattoon will have the best chances of seeing sunshine earlier, but even northeast areas should see sunshine break through later this afternoon. Even limited late afternoon sunshine should help high temperatures reach the mid 40s north of I-74, with lower 50s for areas from Jacksonville to Effingham to Lawrenceville. && .LONG TERM...(Tonight through Friday) ISSUED AT 241 AM CST SAT MAR 5 2016 Mild and wet period shaping up for much of the upcoming week, as upper flow finally trends more toward the southwest. Main issue will be with the rains, as a frontal boundary will be draped over the state part of the time, and will limit some of the rainfall north of it around midweek. High pressure will quickly pass through the Midwest tonight, and southerly winds will be in place by Sunday morning and become a bit gusty. This will bring temperatures well into the 50s, with some 60 degree readings possible over the southwest CWA. Some WAA-type precip expected to develop by afternoon west of the Illinois border, but forecast soundings in our area quite parched below 700 mb until evening, and thus will keep the daytime hours dry albeit with increasing clouds. Have limited mentionable PoP`s Sunday night to west of I-55, with most of the energy tracking into northwest Illinois. On Monday, southerly winds expected to gust from 25-30 mph, pushing temperatures well into the 60s. During this time, an upper trough will be digging southward along the California coast, closing off a low over the Baja. Nice moisture surge coming northward from the Gulf of Mexico will combine with a wave/front in the northern stream to gradually increase rain chances from west to east across the state. Reasonable agreement among the models through about Tuesday evening with the cold front being just to our northwest. Waves of low pressure will surge northeast along the front bringing periods of heavier rain, but how far south the front makes it first will be key. The ECMWF is slowest in exiting the rain (not until Thursday evening over the southeast CWA), while the GFS and Canadian show periodic surges of rain until Thursday morning. Went with categorical PoP`s (80%) for most areas east of I-55 Tuesday night through Wednesday night. WPC progs and blended model guidance suggesting potential for 3-4 inches of rain through the week in this area, subject to the oscillations of the front. Hydrologic Outlook product is being used to address this heavy rain concern for the time being. The upper low will only slowly drift through northern Mexico, cut off from the northern flow through much of the week. Late in the period, the GFS and ECMWF show this low finally ejecting northeast, although the GFS is much faster in bringing the frontal boundary back north. With the front position still a significant question, PoP`s generally remain in place over most of the forecast area into Friday. Temperatures north of the front will cool a bit mid week, but still be mid-upper 50s for highs. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) ISSUED AT 1125 PM CST FRI MAR 4 2016 A cold front, currently over east central Iowa will track across our area Saturday morning. Forecast soundings and last few runs of the HRRR model indicate a deterioration in cigs and vsbys after 06z until the front shifts east of the area after 12z. Subsidence in the wake of the upper wave should bring cigs back to MVFR or even low VFR by afternoon. Once the rain band shifts to our east after 06z, there may be enough lift for some drizzle at our BMI and CMI locations but coverage too limited to include in the TAFs at this time. Surface winds will be southerly at 10 to 15 kts overnight and then become southwest towards dawn at 5 to 10 kts, and then shift into the northwest in the 12z to 15z time frame with speeds of 12 to 17 kts with a few gusts around 23 kts thru 21z before winds diminish quickly from a northerly direction around 00z. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Shimon LONG TERM...Geelhart AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1131 PM CST FRI MAR 4 2016 .UPDATE... ISSUED AT 830 PM CST FRI MAR 4 2016 Another fast moving shortwave to our northwest will sweep across the region late tonight accompanied by scattered rain showers which may mix with a little sleet and light snow across our north for about an hour or two. The cold front, currently over central Iowa, will track through our area after midnight taking the threat for rain with it as it moves to our east by dawn Saturday. Southerly flow ahead of the front will help to keep temperatures rather steady in the mid 30s to around 40 through the evening before falling off towards dawn Saturday. Update already sent out to address precip timing and type across our northern counties, as a result, no additional updates needed at this time. && .SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT) ISSUED AT 320 PM CST FRI MAR 4 2016 SURFACE HIGH SITUATED OVER THE REGION PROVIDING FOR DRY/QUIET CONDITIONS THIS AFTERNOON...WITH A MAJORITY OF THE CWA OBSERVING SUNNY TO PARTLY CLOUDY SKIES. THE EXCEPTION THIS AFTERNOON IS STILL THE FAR WESTERN CWA NEAR THE JACKSONVILLE AREA WHERE LOW STRATUS IS STILL SITUATED. HOWEVER...EXPECT CLOUD COVER TO BEGIN INCREASING THIS AFTERNOON INTO THE EVENING AHEAD OF A COUPLE OF PIECES OF ENERGY AND ATTENDANT SURFACE TROUGH/FRONTAL BOUNDARY DROPPING SOUTHEAST THROUGH THE REGION. MOST GUIDANCE KEEPING THE BULK OF ANY ASSOCIATED PRECIP TO THE NORTH AND NORTHEAST OF THE AREA TONIGHT...WHERE THE STRONGER/MORE ORGANIZED FORCING WILL RESIDE. STRONG WAA ALREADY NOTED APPROACHING NORTHWEST AND WEST CENTRAL ILLINOIS WILL ALSO DROP SOUTHEAST AND EVEN STRENGTHEN AS IT FOCUSES OVER THE CWA THIS EVENING. THIS SHOULD ALLOW THE PREVALENT DRIER AIR IN PLACE TO BECOME OVERCOME WITH LIGHT PRECIP TO AT LEAST BE OBSERVED OVER A FEW HOUR WINDOW TIME FRAME LATE THIS EVENING TO JUST AFTER MIDNIGHT. WITH THIS PRECIP EXPECTED TO BE LIGHT...BRIEF AND LOW IN COVERAGE...HAVE MAINTAINED CHANCE POPS FOR THE ENTIRE AREA TONIGHT. PRECIP SHOULD REMAIN IN THE FORM OF RAIN TONIGHT FOR MOST AREAS GIVEN THE WARMER BOUNDARY LAYER CONDITIONS AND WARM WEDGE ALOFT WITH THE PERSISTENT WAA. HOWEVER...A FEW SNOW FLAKES MAY BE OBSERVED INITIALLY WITH WET BULBING. THIS COULD OCCUR OVER THE FAR NORTHEAST CWA FROM LACON TO DANVILLE...BUT SHOULD BE BRIEF AS THE ENTIRE COLUMN FURTHER WARMS AND WITH THE LOSS OF CRYSTALS. TEMPS DURING THIS TIME WILL LIKELY REMAIN ABOVE FREEZING...WITH ANY FREEZING RAIN NOT EXPECTED. TEMPS MAY BEGIN TO APPROACH THE FREEZING MARK LATE TONIGHT...BUT DO EXPECT ANY PRECIP TO HAVE EXITED BY THIS TIME. THESE MID/UPPER LEVEL FEATURES WILL EXIT TO THE EAST SATURDAY...WITH SURFACE RIDGING EXPECTED TO OCCUR ONCE AGAIN ACROSS THE REGION. THIS SHOULD BRING ANOTHER PERIOD OF DRY WEATHER SATURDAY AND SATURDAY NIGHT. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 346 PM CST FRI MAR 4 2016 A QUIET START TO THE PERIOD IS EXPECTED EARLY NEXT WEEK WHILE UPPER LEVEL RIDGING IS OCCURRING. BACKING LOW/MID LEVEL FLOW IN ADVANCE OF UPPER LEVEL TROUGH OVER THE WESTERN HALF OF THE CONUS WILL HELP STEER IN A WARMER AIRMASS TO THE REGION...WITH ABOVE NORMAL TEMPS EXPECTED BY SUNDAY AND MONDAY. THIS WILL START A PERIOD OF WARMER/ABOVE NORMAL TEMPS FOR THE REGION INTO NEXT WEEK. WITH THIS WARMER AIRMASS IN PLACE...MOISTURE WILL BEGIN TO MAKE A RETURN TO THE AREA...WITH THE PATTERN BECOMING MORE CONDUCIVE OF PERIODIC SHOWER DEVELOPMENT. INCREASING CHANCES FOR SHOWERS WILL RETURN BY SUNDAY NIGHT INTO MONDAY AS SOME WEAKER MID LEVEL IMPULES PUSH THROUGH THE MID MISSISSIPPI VALLEY. HOWEVER...CHANCES REALLY INCREASE CLOSER TO MID WEEK AS LARGE SCALE FORCING RAMPS UP AHEAD OF ADVANCING UPPER LEVEL TROUGH OVER THE CENTRAL CONUS. SHOWERS AND A FEW THUNDERSTORMS WILL BECOME LIKELY DURING THIS TIME WITH THE POSSIBILITY OF REPEATED ROUNDS OF RAIN. THIS WILL BE DUE IN PART TO A STATIONARY BAROCLINIC ZONE IN PLACE SETTING UP THE POSSIBILITY FOR HEAVY RAINFALL...AND WILL NEED TO CONTINUE TO MONITOR THIS PERIOD FOR THIS POTENTIAL. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) ISSUED AT 1125 PM CST FRI MAR 4 2016 A cold front, currently over east central Iowa will track across our area Saturday morning. Forecast soundings and last few runs of the HRRR model indicate a deterioration in cigs and vsbys after 06z until the front shifts east of the area after 12z. Subsidence in the wake of the upper wave should bring cigs back to MVFR or even low VFR by afternoon. Once the rain band shifts to our east after 06z, there may be enough lift for some drizzle at our BMI and CMI locations but coverage too limited to include in the TAFs at this time. Surface winds will be southerly at 10 to 15 kts overnight and then become southwest towards dawn at 5 to 10 kts, and then shift into the northwest in the 12z to 15z time frame with speeds of 12 to 17 kts with a few gusts around 23 kts thru 21z before winds diminish quickly from a northerly direction around 00z. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Smith SHORT TERM...RODRIGUEZ/KREIN LONG TERM...RODRIGUEZ/KREIN AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1044 PM CST FRI MAR 4 2016 .SHORT TERM... 200 PM CST THROUGH SATURDAY... ALL REMAINS ON TRACK FOR A QUICK SHOT OF SNOW TONIGHT ESPECIALLY ALONG AND NORTH OF I-80. THE PRIMARY IMPACT LOOKS TO BE SHARPLY REDUCED VISIBILITY FOLLOWED BY A QUICK COATING OF SNOW ON SOME PAVED SURFACES. THE CENTER OF THE MAIN CLIPPER SHORT WAVE IS IN WESTERN MINNESOTA EARLY THIS AFTERNOON. AS ITS DRIVING JET SPREAD INTO OUR REGION THIS EVENING...HEIGHT FALLS AND ASSOCIATED LIFT WILL MAXIMIZE OVER WISCONSIN AND NORTHERN ILLINOIS. STEEPER MID-LEVEL LAPSE RATES OBSERVED ON UPSTREAM MORNING SOUNDINGS AND EARLY AFTERNOON AIRCRAFT DATA FROM OMAHA WILL CONTINUE TO SPREAD EASTWARD WITHIN THE WARM ADVECTION ZONE SOUTH OF THE VORTICITY CENTER. AS THIS CATCHES UP TO THE LIFT AND SATURATION...THE AREA OF PRECIPITATION PRESENTLY IN MN/NORTHERN IA SHOULD SHOW SOUTHEAST EXPANSION AND PROBABLY INTENSIFICATION DURING THE EARLY TO MID EVENING WHICH CORRELATES TO WHEN IT IS OVER THE AREA. HAVE ONLY MADE FURTHER REFINEMENTS TO HOURLY TIMING OF PRECIPITATION WHICH LOOKS TO BE MAINLY WET SNOW THIS EVENING ESPECIALLY IN NORTHEAST ILLINOIS AND FAR NORTHWEST INDIANA. ONSET OF PRECIPITATION COULD BRIEFLY BE A MIX WITH RAIN...AND TOWARD I-39 IT COULD REMAIN A MIX OR EVEN JUST RAIN SHOWERS THIS EVENING. BECAUSE OF THE QUICK MOVEMENT OF THE FORCING AND FOCUS...THE SNOWFALL LOOKS TO LAST TWO HOURS OR LESS IN MOST LOCATIONS...WITH THE MODERATE INTENSITY EVEN A SHORTER SPAN. CONVECTIVE ALLOWING MODELS CONTINUE TO SUPPORT THIS IN THEIR REFLECTIVITY... VISIBILITY...AND HOURLY SNOWFALL FORECASTS. THE PRIMARY TIMING FOR THE CHICAGO METRO LOOKS TO BE BETWEEN 9 PM AND MIDNIGHT. WETTER QUALITY OF THE SNOW AND TEMPERATURES OF 31-35 SHOULD LIMIT MUCH FOR ACCUMULATION ON PAVEMENT...THOUGH GRASSY SURFACES WILL PROBABLY SEE A QUICK COAT IN NORTH OF I-80 COMMUNITIES. SOUTH OF I-80 MORE LIMITED TIME AND FORCING FOR SATURATION WILL PROVIDE MORE VIRGA /RADAR ECHOES NOT REACHING THE GROUND/ THAN PRECIPITATION...SO NO ACCUMULATION FORECAST. LOSS OF ICE HAPPENS RAPIDLY BY MIDNIGHT WHICH MAKES SENSE GIVEN UPSTREAM SATELLITE TRENDS. LOW-LEVEL SATURATION AND LIFT STILL ARE PROVIDED ON RAP AND NAM SOUNDINGS EVEN THROUGH DAYBREAK. SO CONTINUE FORECAST DRIZZLE CHANCES. THE TEMPERATURES SHOULD BE INCHING UP LATE TONIGHT SO NOT TOO CONCERNED ON FREEZING DRIZZLE BUT DO INDICATE THE BRIEF POSSIBILITY IN THE FORECAST WHERE OUR DETERMINISTIC TEMPERATURE FORECASTS OUR 30-32 FOR A FEW HOURS. HAVE TRENDED MORE CLOUDY FOR SATURDAY ESPECIALLY FOR THE EASTERN HALF OF THE CWA. HAVE DONE SO AS THE CLIPPER BROADENS TO OUR NORTHEAST AND KEEPS CYCLONIC FLOW ACROSS THE REGION. CLEARING SHOULD OCCUR FROM WEST-TO-EAST SOMETIME IN THE AFTERNOON THROUGH IT COULD TAKE UNTIL EARLY SATURDAY EVENING. HAVE HIGHS AROUND NORMAL WITH 40 EAST TO 45 WEST. MTF && .LONG TERM... 213 PM CST SATURDAY NIGHT THROUGH FRIDAY... A SHIFT TOWARDS A WARM AND ACTIVE SPRING-LIKE PATTERN IS EXPECTED TO OCCUR LATE IN THE WEEKEND INTO EARLY NEXT WEEK BRINGING UNSEASONABLY WARM CONDITIONS AS WELL AS PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS. BY SATURDAY NIGHT...SURFACE RIDGE IS EXPECTED TO BUILD ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA BRINGING QUIET CONDITIONS BUT FAVORABLE FOR RADIATIONAL COOLING...AND WHAT LOOKS TO BE OUR COLDEST NIGHT OVER THE UPCOMING WEEK. FORECASTING LOWS IN THE 20S ACROSS THE FORECAST AREA...HOWEVER WOULDNT BE SURPRISED TO SEE A FEW OF THE TYPICAL COLD SPOTS DIPPING INTO THE TEENS. HIGH PRESSURE WILL SHIFT TO OUR EAST SUNDAY WITH SOUTHERLY FLOW OVERSPREADING THE REGION. THE HIGH IS PROGGED TO BECOME ANCHORED JUST OFF THE SOUTHEASTERN ATLANTIC COAST WHILE UPPER LEVEL PATTERN CONTINUES TO AMPLIFY WITH STRONG EAST COAST UPPER RIDGE DEVELOPING BY THE MIDDLE OF NEXT WEEK AND DEEP TROUGHING DEVELOPING ACROSS THE WESTERN CONUS. LOCALLY THIS WILL MEAN A WARMING TREND THROUGH TUESDAY WHEN TEMPERATURES ARE FORECAST TO RISE INTO THE MID 60S ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. AS DEEP TROUGHING MOVES OVER THE MID SECTION OF THE COUNTRY...WE WILL SET THE STAGE FOR SEVERE WEATHER TO OCCUR ACROSS PORTIONS OF THE PLAINS AND MIDWEST EARLY NEXT WEEK AND WHILE ITS TOO EARLY TO HONE IN ON SPECIFICS FOR SEVERE WEATHER...MODELS DO SHOW INSTABILITY BUILDING THIS FAR NORTH SO A THUNDERSTORM MENTION IS INCLUDED IN THE FORECAST FOR NOW...MAINLY ON TUESDAY FOR OUR AREA. UPPER LOW EXPECTED TO CUT OFF ACROSS THE DEEP SOUTH AROUND MIDWEEK AND EVENTUALLY MEANDER ACROSS THE MIDWEST LATE IN THE WEEK OR NEXT WEEKEND. DETAILS REMAIN UNCLEAR AT THIS POINT BUT IT DOES APPEAR WE WILL GENERALLY STAY IN A WARMER AND WETTER PATTERN LATE IN THE WEEK INTO NEXT WEEKEND. DEUBELBEISS && .AVIATION... FOR THE 06Z TAFS... MAIN FORECAST CONCERNS FOR TAFS IS WITH MVFR/POTENTIAL IFR CIGS AND MVFR VIS IN DRIZZLE AND LIGHT FOG OVERNIGHT. MID-LEVEL DISTURBANCE WHICH BROUGHT SNOW TO THE REGION DURING THE MID-LATE EVENING HOURS WAS MOVING THROUGH THE AREA AT MIDNIGHT. FAIRLY DISTINCT BACK EDGE TO MORE ORGANIZED SNOW...ROUGHLY FROM KMKE TO KVYS/KPIA AT 0440Z. THUS IT APPEARS MOST SNOW WILL END BY 06Z...PERHAPS SHORTLY AFTER AT GYY. IR SATELLITE IMAGERY DEPICTS EXTENSIVE AREA OF LOW CLOUDS EXTENDING UPSTREAM INTO THE UPPER MISSISSIPPI VALLEY...WHICH MODEL FORECAST SOUNDINGS INDICATE WILL LIKELY LINGER ACROSS THE TERMINALS INTO SATURDAY. PERSISTENT LIFT ABOVE THIS LOW LEVEL MOISTURE WILL LIKELY PRODUCE DRIZZLE FOR THE REMAINDER OF THE OVERNIGHT HOURS...WITH A BRIEF WINDOW OF FREEZING DRIZZLE POSSIBLE AFTER MIDNIGHT BEFORE TEMPS SLOWLY RISE ABOVE FREEZING DURING THE PRE-DAWN HOURS. SINKING AIR BEHIND THE DEPARTING WAVE SHOULD LIMIT ANY PRECIP BY SATURDAY MORNING... THOUGH GRADUALLY RISING MVFR CIGS LIKELY TO LINGER THROUGH A GOOD PORTION OF THE DAY BEFORE SCATTERING LATE. SOUTH WINDS NEAR 10 KT WILL SHIFT WEST BY MORNING AND THEN NORTHWEST WITH GUSTS NEAR 20 KT SATURDAY MORNING. WINDS THEN DIMINISH AND BECOME NORTH-NORTHEAST SATURDAY EVENING AS SURFACE HIGH PRESSURE APPROACHES. RATZER && .MARINE... 213 PM CST A CLIPPER LIKE SNOW SYSTEM WILL DROP ACROSS THE UPPER MIDWEST AND WESTERN GREAT LAKES REGION TODAY WITH MODERATE SOUTHERLY FLOW OF 20 TO 25 KT EXPECTED AHEAD OF THIS SYSTEM THIS EVENING AND TONIGHT. THE LOW WILL CROSS OVER THE SOUTHERN HALF OF LAKE MICHIGAN ON SATURDAY WITH WINDS TURNING NORTHERLY BEHIND...THEN DIMINISHING AS HIGH PRESSURE BEGINS TO BUILD OVERHEAD FOR SATURDAY NIGHT. THE HIGH WILL CONTINUE TO THE SOUTHEAST STATES AND EVENTUALLY SET UP NEAR BERMUDA WHERE IT WILL REMAIN ANCHORED MUCH OF THE UPCOMING WEEK WHICH WILL HELP DRIVE A MAJOR PATTERN CHANGE ACROSS THE REGION. LOW PRESSURE DEVELOPS OVER THE PLAINS SUNDAY INTO EARLY NEXT WEEK WITH SOUTHERLY FLOW RAMPING BACK UP AGAIN TO AROUND 30 KT SUNDAY. MODERATE SOUTHERLY FLOW OF 20 TO 25 AND OCCASIONALLY 30 KT WILL CONTINUE THROUGH TUESDAY HELPING SPREAD AN UNSEASONABLY WARM AND MOIST AIRMASS INTO THE GREAT LAKES. THE HIGH DEWPOINTS ARE EXPECTED TO RESULT IN AREAS OF FOG DEVELOPING OVER THE LAKE. ALSO CANNOT RULE OUT SOME THUNDERSTORMS...PARTICULARLY ON TUESDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS JACKSON KY
102 AM EST SAT MAR 5 2016 .UPDATE... ISSUED AT 1058 PM EST FRI MAR 4 2016 THE LOW CLOUDS HAVE BROKEN UP AS THE LOW LEVEL FLOW HAS BECOME MORE WESTERLY UNDER A WEAK AREA OF RIDGING IN BETWEEN A DEPARTING SYSTEM AND AN APPROACHING UPPER LEVEL DISTURBANCE AND COLD FRONT. MODEL TIME HEIGHT SECTIONS SUGGEST BREAKS OR EVEN CLEAR SKIES FOR THE NEXT 5 HOURS OR SO BEFORE CLOUDS SHOULD THICKEN AND LOWER IN ADVANCE OF THE COLD FRONT. THIS SHOULD LEAD TO CONTINUED FOG DEVELOPMENT AND WITH TEMPERATURES NEAR FREEZING PATCHY BLACK ICE IS A CONCERN ON BRIDGES AND OVERPASSES. ELSEWHERE NORTH OF THE MTN PARKWAY WHERE SNOW REMAINS ON THE GROUND MELTING ON FRIDAY LED TO WET ROADS IN SOME LOCATIONS. THIS COULD ALSO LEAD TO SOME PATCHY BLACK ICE. THE POTENTIAL FOR BLACK ICE HAS BEEN ADDED TO THE HWO. OTHERWISE...AS FOR THE SYSTEM ARRIVING ON SATURDAY... SCATTERED SHOWERS POSSIBLY ARRIVING AS EARLY AS 9 AM TO 10 AM EST PER THE 0Z GFS AND RECENT HRRR RUN...OR LATER PER RAP AND NAM GUIDANCE. ANY INITIAL PRECIPITATION COULD FALL AS A RAIN AND SNOW MIX BEFORE WARM ADVECTION THROUGHOUT THE COLUMN IN ADVANCE OF THE COLD FRONT TURNS ANY PRECIPITATION TO ALL RAIN BY MIDDAY. UPDATE ISSUED AT 630 PM EST FRI MAR 4 2016 WEAK UPSLOPE FLOW AND MOIST LOW LEVELS IS LEADING TO SOME DRIZZLE OR VERY LIGHT RAIN...AND OR HIGH ELEVATION FLURRIES ACROSS THE REGION. THIS SHOULD CONTINUE MAINLY ACROSS THE SOUTHEAST PART OF THE CWA UNTIL LATE EVENING BEFORE THE LOW LEVEL FLOW BECOMES MORE WESTERLY AND THE MOISTURE BECOMES MORE SHALLOW. PATCHY FOG SHOULD ALSO BE COMMONPLACE...BOTH ON THE RIDGES AND IN SOME VALLEY LOCATIONS. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 345 PM EST FRI MAR 4 2016 LATEST GOES WV IMAGERY SHOWS THE UPPER LEVEL TROUGH AXIS PUSHING OFF TO THE EAST ALLOWING FOR SOME TEMPORARY DRYING AT MID LEVELS. AT LOW LEVELS...HOWEVER...MOISTURE AND CLOUDS WILL LIKELY REMAIN IN PLACE THROUGH THE OVERNIGHT PERIOD...WITH THE POTENTIAL FOR SOME SCOURING OUT OF THE CLOUDS IN NORTHWESTERN LOCATIONS. A FEW STRAY SHOWERS ARE ALSO POSSIBLE THIS EVENING. LOWS WILL STAY IN THE LOWER 30S. GOES IR IMAGERY SHOWS MID AND HIGH LEVEL CLOUDS STARTING TO SPREAD INTO THE REGION AHEAD OF THE NEXT SHORTWAVE TROUGH. THIS TROUGH WILL DROP DOWN FROM THE NORTHERN PLAINS TONIGHT AND PASS THROUGH EASTERN KENTUCKY DURING THE DAY TOMORROW...PROVIDING CHANCES OF MAINLY RAIN SHOWERS. DUE TO THE COLDER TEMPERATURES IN THE NORTHERN COUNTIES...KEPT A BRIEF CHANCE OF A RAIN/SNOW MIX EARLY ON. RAIN SHOWERS WILL CONTINUE THROUGHOUT THE DAY AND THEN GRADUALLY PUSH OFF TO THE EAST SATURDAY NIGHT. HIGHS WILL REBOUND INTO THE UPPER 40S AND LOWER 50S NORTH...WITH SOME MID 50S NOTED IN THE SOUTHWEST. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 405 PM EST FRI MAR 4 2016 THE MODELS HAVE COME INTO BETTER AGREEMENT ALOFT THROUGH THE EXTENDED PORTION OF THE FORECAST. THEY ALL DEPICT THE DEPARTURE OF A SHORTWAVE TROUGH TO THE SOUTHEAST ON SUNDAY WITH RIDGING BUILDING INTO THE AREA THROUGH MONDAY MORNING. AROUND THIS TIME A DEEP AND BROAD TROUGH STARTS TO SET UP OVER THE WESTERN UNITED STATES. THIS TROUGH SETTLES DEEP INTO SOUTHERN CALIFORNIA AND INTO NORTHERN MEXICO WHILE SENDING SPURS OF ENERGY NORTHEAST INTO THE SOUTHERN PLAINS. WITH TIME...THE RIDGE BUILDS STRONGER OVER THE SOUTHERN APPALACHIANS WHILE THE WESTERN TROUGH CLOSES OFF OVER THE MOUNTAINS OF NORTHWESTERN MEXICO. THIS WILL SET UP BROAD SOUTHWEST FLOW INTO THE SOUTHERN PLAINS...ONLY SLOWLY MOVING EAST THROUGH THE MIDDLE OF THE WEEK. ALL THESE FEATURES TIGHTEN UP INTO WEDNESDAY WITH MORE RIDGING EAST AND TROUGHING TO THE SOUTHWEST. THROUGH THE DEEP SOUTH SOUTHWEST FLOW...FROM OVER THE WESTERN GULF...PLENTY OF ENERGY WILL RUN NORTHEAST INTO THE SOUTHERN PLAINS AND CENTRAL MISSISSIPPI VALLEY INTO THURSDAY. MEANWHILE... EAST KENTUCKY WILL BE UNDER THE HEAVY INFLUENCE OF STRONG RIDGING WHOSE CENTER WILL SLOWLY SLIP SOUTH TO SOUTHERN FLORIDA. THE CUTOFF SOUTHERN LOW WILL START TO GET PICKED UP BY THE NORTHERN STREAM LATE IN THE WEEK WITH A BETTER CHANCE OF ENERGY SPILLING INTO KENTUCKY. FOR FRIDAY...THE MODELS ARE IN GENERAL AGREEMENT WITH THE BROAD LOW MOVING TOWARD THE MISSISSIPPI DELTA WITH GENERAL SOUTHERLY FLOW CONTINUING OVER KENTUCKY. DUE TO THE DECENT MODEL AGREEMENT HAVE FAVORED A GENERAL BLEND FOR THE FORECAST DETAILS. SENSIBLE WEATHER WILL FEATURE MODERATING TEMPERATURES ON SUNDAY AS HIGH PRESSURE CROSSES THE OHIO VALLEY AND WEAK LOW PRESSURE MOVES AWAY FROM THE AREA. FOLLOWING THIS...THE HIGH MOVES TO THE EAST COAST AND AS IT DOES SO TEMPERATURES WILL REALLY SOAR REACHING WELL INTO THE MID 60S BY MONDAY AFTERNOON. THIS PATTERN WILL THEN BE RATHER STEADY STATE THROUGH THE BULK OF THE WEEK. HIGH PRESSURE WILL KEEP THE RAINS OF THE WEST AT BAY FOR MOST OF THE CWA DURING THIS TIME. THIS WILL LIKELY SPARE EAST KENTUCKY FROM THE VERY HEAVY RAINS THAT WILL BE SETTING UP FOR PARTS OF THE SOUTHERN PLAINS AND INTO THE WESTERN OHIO VALLEY. EVENTUALLY...THOUGH... THE PATTERN WILL SHIFT EAST ENOUGH THAT SHOWERS AND POSSIBLE THUNDERSTORMS WILL MOVE INTO OUR AREA FOR WEDNESDAY AND THURSDAY. ADDITIONAL SHOWERS CAN BE ANTICIPATED FOR FRIDAY...AS WELL. ALSO THROUGH IT ALL...TEMPERATURES WILL REMAIN WELL ABOVE NORMAL BOTH FOR HIGHS AND NIGHTTIME LOWS. THE ONLY CONCERN WILL BE FOR PERHAPS EXCESSIVE RAINS LATE IN THE WEEK AND BEYOND AS THIS AREA OF VERY MOIST LOW PRESSURE SLOWLY EDGES INTO THE DEEP SOUTH AND TENNESSEE VALLEY. ADJUSTED THE GRIDS FROM THE CR INIT MAINLY TO ACCOUNT FOR DECENT SMALL RIDGE TO VALLEY TEMPERATURE DIFFERENCES SUNDAY THROUGH WEDNESDAY NIGHTS. ALSO TWEAKED THE POP GRIDS FOR THE LATTER PART OF THE PERIOD TO SLOW THE ARRIVAL OF THE HIGHER POPS INTO OUR WESTERN ZONES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1257 AM EST SAT MAR 5 2016 LOW LEVEL MOISTURE REMAINS ACROSS MUCH OF THE REGION...DESPITE SOME CLOUDS STARTING TO MOVE IN FROM THE NORTH. AS A RESULT...FOG CONTINUES ACROSS THE TAF SITES...WITH MOST LOCATIONS AT OR BELOW AIRPORT MINIMUMS FOR BOTH VIS AND CIG HEIGHTS. EVEN AS CLOUDS CONTINUE TO OVERSPREAD AHEAD OF OUR NEXT WEATHER SYSTEM...SUBSIDENCE AND MOISTURE AT THE SURFACE SHOULD REMAIN STRONG ENOUGH TO KEEP FOG INTACT THROUGHOUT THE NIGHT. CONDITIONS WILL IMPROVE AS DAY BREAKS AND SCATTERED LIGHT RAIN SHOWERS BEGIN IMPACTING THE NORTHEASTERN PORTION OF THE STATE BY 12Z...REACHING KSYM BY 14Z AND MAKING THEIR WAY SOUTHEAST ACROSS THE REST OF THE TAF SITES. COVERAGE WILL BE SPOTTY...BUT RAIN SHOULD REMAIN LIGHT...SO CONTINUED WITH VCSH MENTION AT MOST TAF SITES FOR NOW UNDER GENERALLY MVFR CIGS. RAIN WILL QUICKLY EXIT OVERNIGHT...BUT ANOTHER SUBSIDENCE/LLVL MOISTURE SET UP WILL LIKELY LEAD TO MORE FOG DEVELOPMENT ACROSS THE REGION. OVERALL...WINDS SHOULD REMAIN LIGHT THROUGHOUT THE TAF PERIOD...PREDOMINATELY FROM THE SW BEFORE BECOMING MORE WRLY BEHIND THE PASSING COLD FRONT AFTER 0Z SUNDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...JVM LONG TERM...GREIF AVIATION...JMW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
447 AM EST SAT MAR 5 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 445 AM EST SAT MAR 5 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS A RIDGE OVER THE ROCKIES AND A TROF OVER ERN NAMERICA. SHORTWAVE THAT BROUGHT SNOW INTO UPPER MI OVER THE LAST 12HRS OR SO IS TRACKING SE THRU WI. THIS WILL BE THE FINAL SHORTWAVE TO DROP SE THRU THE AREA BEFORE A TRANSITION TO A WARM SPLIT FLOW PATTERN WITH ABOVE NORMAL HEIGHTS AND W TO SW FLOW ACROSS THE UPPER GREAT LAKES NEXT WEEK. RADAR TRENDS OVER THE LAST COUPLE OF HRS SHOW SNOW DIMINISHING OVER UPPER MI...AND UPSTREAM... KDLH RADAR SHOWS VERY LITTLE PCPN REMAINING. THERE WERE OBS AND REPORTS OF SOME -FZDZ EARLIER IN THE NIGHT OVER WRN UPPER MI AND NRN WI AS THE HEAVIER SNOW DEPARTED. RECENTLY...THERE ARE FEWER OBS SHOWING UNKNOWN PCPN...SO -FZDZ MAY BE DIMINISHING. WITH SHORTWAVE CONTINUING SE TODAY...DIMINISHING PCPN WILL END FROM NW TO SE. SOUTHERLY FLOW ON LAKE MI PERSISTS THRU MID TO LATE MORNING WHICH SHOULD HELP WEAKLY LAKE ENHANCED SNOW TO LINGER. THUS...HIGHEST POPS WILL PAINTED OVER THE E THIS MORNING WITH PERHAPS ANOTHER HALF INCH OR SO OF SNOW ACCUMULATION. TO THE W... WILL KEEP A MENTION OF -FZDZ/-SN MAINLY IN THE COUNTIES BORDERING WI FOR THE NEXT FEW HRS. SATELLITE IMAGERY SHOWS CLEARING NOT THAT FAR AWAY ACROSS NRN LAKE SUPERIOR. WITH HIGH PRES RIDGE BUILDING INTO THE UPPER GREAT LAKES THIS AFTN...LOW-LEVEL NORTHERLY WINDS AHEAD OF THE RIDGE WILL DIMINISH. THIS INCREASES THE UNCERTAINTY IN HOW MUCH CLEARING WILL OCCUR...ESPECIALLY SINCE UPSLOPE FLOW OFF THE LAKE UNDER A LOWERING INVERSION SHOULD GREATLY SLOW THE CLEARING PROCESS. KEWEENAW OBVIOUSLY HAS THE BEST CHC OF AT LEAST PARTIALLY CLEARING OUT TODAY GIVEN THE CLOSE PROXIMITY OF CLEAR SKIES ALREADY EARLY THIS MORNING. FOR NOW...FCST WILL SHOW A VERY GRADUAL DECREASE IN CLOUDS FROM THE N AND NW THIS AFTN INTO THIS EVENING. CLOUD FCST INTO TONIGHT REMAINS A BIT TRICKY. IF THE EXTENSIVE LOW CLOUDS ACROSS MN/WI PERSIST THRU THE DAY...THESE CLOUDS MAY MOVE BACK INTO THE AREA TONIGHT ONCE S TO SW FLOW DEVELOPS/INCREASES AFTER THE HIGH PRES RIDGE PASSES. OTHERWISE...PROVIDED MUCH OF TODAYS CLOUD COVER DEPARTS BY EVENING...THERE WILL BE AN OPPORTUNITY FOR TEMPS TO FALL QUICKLY THIS EVENING UNDER LIGHT/CALM WIND. LEANED FCST TO THE COLDER BIAS CORRECTED REGIONAL/GLOBAL CANADIAN MODELS DUE TO THEIR NORMAL SUPERIOR PERFORMANCE IN RADIATIONAL COOLING SITUATIONS. TRADITIONAL COLD SPOTS WILL FALL DOWN INTO THE MID TEENS IF SKIES ARE MOSTLY CLEAR THIS EVENING. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 349 AM EST SAT MAR 5 2016 ADVERTISED EARLY SPRING PREVIEW IS STILL ON TRACK FOR EARLY NEXT WEEK AND BEYOND. SUBSTANTIAL WARM ADVECTION KICKS IN ON SUNDAY. PRESSURE GRADIENT WILL TIGHTEN SIGNIFICANTLY BETWEEN SURFACE LOW/SHORTWAVE MOVING THROUGH NORTHERN ONTARIO AND HIGH PRESSURE ALONG THE EAST COAST. 85H TEMPS CLIMB INTO THE PLUS 5 TO 8C RANGE. EVEN WITH THE STABLE THERMAL PROFILE 92H WINDS ARE FORECAST UP TO 40 KNOTS SO EXPECT WINDS TO BE PRETTY GUSTY. NAM REMAINS CONSISTENT...AND TO A LESSER EXTENT THE GFS...IN SHOWING ENOUGH MOISTENING THROUGH THE DAY THAT THERE MAY EVEN BE SOME LIGHT PRECIPITATION OVER EASTERN AREAS BY LATE IN THE DAY. WILL INTRODUCE SOME SLIGHT CHANCE POPS ACROSS THE EAST FOR SOME LIGHT RAIN/DRIZZLE. TEMPS ON SUNDAY WILL CLIMB INTO THE 40S WEST WHILE LAKE MICHIGAN COOLING WITH THE STRONG SOUTHWESTERLY WINDS WILL KEEP TEMPS IN THE UPPER 30S ACROSS THE EAST. THE BEST CHANCES FOR ANY WIDESPREAD PRECIPITATION...ALBEIT RELATIVELY LIGHT...WILL OCCUR DURING THE MONDAY THROUGH TUESDAY NIGHT TIME PERIOD. WHILE TEMPERATURES WILL BE WELL ABOVE NORMAL...IT WILL PROBABLY BE PRETTY GLOOMY DURING THIS PERIOD. CONTINUED WARM ADVECTION...DEWPOINTS CLIMBING INTO THE 30S AND 40S...AND A MELTING SNOWPACK WILL YIELD PLENTY OF LOW CLOUDS...PATCHY FOG...AND DRIZZLE. SHEARING OUT SHORTWAVE EJECTING WEST OF THE AREA ON TUESDAY WITH SURFACE LOW PASSING NORTHWEST OF LAKE SUPERIOR WILL BRING THE BEST CHANCE OF RAIN ON TUESDAY. WITH DYNAMICAL FORCING ON THE WANE AND LINGERING MID LEVEL DRY AIR ANY PRECIPITATION WILL BE PRETTY LIGHT. AS TRAILING COLD FRONT CROSSES THE AREA LATE TUESDAY AND WITH FAIRLY STEEP MID LEVEL LAPSE RATES STILL CANNOT RULE THE POSSIBILITY OF A THUNDERSTORM ALONG THE FRONT. HOWEVER...CAPPING MAY REMAIN TOO STRONG TO ALLOW ANY DEEP CONVECTION. DESPITE THE CLOUDS TEMPERATURES WILL APPROACH 50 FOR MANY ON MONDAY AND INTO THE 50S ON TUESDAY AWAY FROM THE COOLING INFLUENCES OF THE LAKES...ESPECIALLY LAKE MICHIGAN. DRIER AIR ALONG WITH SOME COOLING BEHIND THE FRONT WILL ALLOW PRECIPITATION TO COME TO AN END TUESDAY NIGHT. FORECAST LOOKS DRY DURING THE WEDNESDAY THROUGH FRIDAY PERIOD. AFTER A BRIEF COOL DOWN WEDNESDAY...ALTHOUGH STILL ABOVE NORMAL...MILD PACIFIC AIR WILL RETURN FOR LATE IN THE WEEK WITH DAYTIME TEMPS ONCE AGAIN APPROACHING 50 FOR MANY BY LATE IN THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1159 PM EST FRI MAR 4 2016 EXPECT IFR TO POSSIBLY LIFR CONDITIONS AT KIWD AND KSAW OVERNIGHT AS LIGHT SNOW CHANGES TO MIX OF FLURRIES/FZDZ AND CIGS CONTINUE TO LOWER AS MOISTURE REMAINS TRAPPED IN THE LOW-LEVELS. CONDITIONS AT KCMX COULD REMAIN PREVAILING MFVR WITH ONLY IFR AT TIMES AS NE FLOW OVERNIGHT WILL BE MORE OF A DOWNSLOPE FLOW AND ALSO KCMX WILL BE FARTHER FROM DEEP MOISTURE OF SYSTEM PASSING TO SOUTH. ONCE THE SYSTEM SLIDES OUT ON SAT...EXPECT IFR TO LOW MVFR DECK TO STAY IN PLACE INTO AT LEAST EARLY AFTN ALONG WITH LINGERING FLURRIES POSSIBLE. HIGH PRESSURE MOVING IN LATE AFTERNOON FROM THE WEST SHOULD ALLOW FOR CONDITIONS TO IMPROVE TO VFR AT KIWD AND KCMX AND TOWARD EVENING AT KSAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 445 AM EST SAT MAR 5 2016 EXPECT LIGHT WINDS...MOSTLY UNDER 15KT TO BE THE RULE ACROSS LAKE SUPERIOR TODAY UNDER A WEAK PRES GRADIENT WITH HIGH PRES RIDGE ARRIVING IN THE AFTN. PRES GRADIENT WILL THEN TIGHTENT TONIGHT AND SUN AS THE RIDGE SHIFTS TO THE E COAST AND A LOW PRES MOVES ACROSS SCNTRL CANADA. S TO SW WINDS WILL RAMP UP TO AS HIGH AS 30KT LATE TONIGHT AND SUN. NOT OUT OF THE QUESTION THAT A FEW GALE FORCE GUSTS COULD OCCUR OVER EASTERN LAKE SUPERIOR SUN. WINDS WILL THEN DIMINISH SUN NIGHT/MON UNDER A WEAKENING PRES GRADIENT. AS LOW PRES TRACKS FROM THE WESTERN PLAINS MON MORNING TO NORTHERN ONTARIO TUE AND QUEBEC WED...WINDS WILL AGAIN INCREASE TO 15-25KT AT TIMES TUE/WED. SOME FOG MAY FORM OVER THE CHILLY WATERS MON NIGHT/TUE AS MOISTER AIR MOVES INTO THE UPPER LAKES AHEAD OF THE LOW PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...MZ AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
309 AM EST SAT MAR 5 2016 .DISCUSSION... LIGHT SNOW OVERSPREAD MUCH OF SE MI OVERNIGHT. SFC OBSERVATIONS AND RADAR SUGGEST SOME LOCALS /PARTICULARLY SOUTH OF THE I-69 CORRIDOR/ HAVE BEEN EXPERIENCING INTERVALS OF FAIRLY GOOD SNOWFALL RATES. THIS SNOW IS OCCURRING WITHIN A REGION OF MID LEVEL ISENTROPIC ASCENT AHEAD OF AN UPPER SHORT WAVE NOW OVER WISCONSIN...AIDED BY A LEAD SHORT WAVE IMPULSE NOW ROTATING INTO SE MI. THE UPSTREAM MID LEVEL TROUGH WILL ROTATE INTO THE OHIO VALLEY BY AFTERNOON...WITH THE ASSOCIATED SFC LOW /OVER CNTRL WISCONSIN AS OF 07Z/ TRACKING INTO NRN INDIANA BY EARLY AFTERNOON. THE REGIONAL WATER VAPOR LOOP SHOWS THE AXIS OF DEEP LAYER MOISTURE ALREADY OVER SE MI...WITH MID LEVEL DRY AIR FAST MOVING INTO SW LOWER MI. THIS LOSS OF MID LEVEL MOISTURE IS LEADING TO AN ABRUPT END TO THE LIGHT SNOW OVER SW LOWER ATTM. MODEL RH PROGS AND SOUNDINGS /WITH SUPPORT FROM THE WATER VAPOR LOOP/ INDICATE THE MID LEVEL DRY AIR WILL OVERSPREAD SE MI BY 12Z. THE RESULTING BRIEF DURATION OF THE SNOW EARLY THIS MORNING WILL KEEP ACCUMS TO AN INCH OR LESS /WITH THE HIGHEST AMOUNTS SOUTH OF I-69/. DESPITE THE LOSS OF MID LEVEL MOISTURE...THERE WILL BE AN ADDITIONAL INFLUX OF LOW LEVEL MOISTURE /SUB 850MB/ DRIVEN INTO SE MI DURING THE MORNING. THIS WILL PROVIDE A GOOD SET UP FOR SOME FREEZING DRIZZLE. THIS AND THE AMOUNT OF FZDZ REPORTS ACROSS WISCONSIN SUPPORT ADDING AREAS OF FZDZ TO THE MORNING FORECAST. BY THE TIME THAT CONDITIONS BECOME OPTIMAL FOR FZDZ...SFC TEMPS SHOULD BE WARMING INTO THE LOWER 30S AND LIKELY ABOVE FREEZING BY NOON. THIS AND THE POTENTIAL SHORT DURATION OF ANY DRIZZLE WILL SUPPORT HOLDING OFF ON ANY TYPE OF WINTER WX ADVISORIES FOR THE TIME BEING. DEEP LAYER MOISTURE WILL ROTATE BACK INTO SE MI THIS AFTERNOON. WITH SOME STEEP MID LEVEL LAPSE RATES AND DIURNAL INSTABILITY...SNOW SHOWER ACTIVITY IS POSSIBLE. THE NAM AND HRRR SUGGEST SOME FGEN DEVELOPMENT ALONG THE MID TROPOSPHERIC FRONT...GENERALLY SOUTH OF THE M 59 CORRIDOR EARLY IN THE AFTERNOON. THIS WILL NOT ONLY WARRANT HIGHER POPS IN THESE LOCALS BUT ALSO SUGGEST SOME ADDITIONAL LIGHT AFTERNOON SNOW ACCUMS /POSSIBLY A HALF INCH/. SFC HIGH PRESSURE WILL EXPAND ACROSS SE TONIGHT AMIDST RISING MID LEVEL HEIGHTS IN THE WAKE OF THE DEPARTING UPPER TROUGH. LOW LEVEL ANTICYCLONIC FLOW AND DRY AIR ADVECTION SHOULD CLEAR THE LOW CLOUDS OUT LATE IN THE NIGHT...SUPPORTING A BRIEF PERIOD OF DECENT RADIATIONAL COOLING. IF THIS COOLING OCCURS A LITTLE EARLIER...LATER SHIFTS WILL HAVE TO CONSIDER ADDING FOG TO THE FORECAST. LONG WAVE RIDGE AMPLIFICATION ACROSS THE ERN US EARLY NEXT WEEK AND THE ESTABLISHMENT OF STRENGTHENING SOUTHWEST FLOW FROM THE SRN PLAINS INTO THE UPPER MIDWEST AND GREAT LAKES WILL SUPPORT A DRAMATIC WARM UP BEGINNING SUNDAY AND PERSISTING THROUGH AT LEAST TUESDAY. DESPITE THE SNOW COVER...THE STRONG LOW LEVEL WARM AIR ADVECTION WITHIN THE WELL MIXED SW FLOW WILL SUPPORT TEMPS ON THE HIGH END OF GUIDANCE /40S SUNDAY...50S MON...60S TUES/. CONSENSUS AMONG THE MEDIUM RANGE MODEL SUITE INDICATE BETTER RAINFALL CHANCES MID TO LATE WEEK AS MUCH DEEPER MOISTURE GETS ADVECTED INTO THE GREAT LAKES. A GOOD DEAL OF FCST UNCERTAINTY REVOLVES AROUND TIMING A BACK DOOR COLD FRONT THROUGH THE AREA NEXT WEEK. MODEL SOLUTIONS DIVERGE WITH RESPECT TO TIMING AND AMPLITUDE OF AN UPPER WAVE TRACKING ACROSS CANADA WHICH RESULTS IN A LARGE SPREAD IN TIMING THIS BACK DOOR COLD FRONT INTO SE MI. IT LOOKS AS THOUGH THIS FRONT WILL MOVE THROUGH SOMETIME IN THE WED TO THURS TIME FRAME AND WILL HAVE THE POTENTIAL TO BRING MUCH COOLER LAKE MODIFIED BOUNDARY LAYER AIR INTO THE AREA /WITH WARM MOIST SOUTHWEST FLOW ALOFT STILL PROVING PERIODIC CHANCES FOR RAIN SHOWERS/. && .MARINE... WINDS WILL REMAIN LIGHT TODAY...GENERALLY UNDER 10 KNOTS...AS LOW PRESSURE SLIDES FROM THE WESTERN GREAT LAKES INTO THE OHIO VALLEY TODAY...AND THEN A RIDGE OF HIGH PRESSURE SHIFTS INTO THE AREA TONIGHT. LOW PRESSURE TRACKING ACROSS HUDSON BAY AND ONTARIO SUNDAY INTO SUNDAY NIGHT WILL THEN PROVIDE A TIGHTER SURFACE PRESSURE GRADIENT OVER THE AREA...CAUSING WINDS TO INCREASE. THE STRONGEST WINDS LOOK TO OCCUR OVER THE OPEN WATERS OF LAKE HURON...WITH SPEEDS INTO THE 20 TO 25 KNOT RANGE. GUSTS SHOULD REMAIN BELOW GALE FORCE HOWEVER AS WARMER AIR SURGING INTO THE AREA WILL PROVIDE A HIGH DEGREE OF STABILITY OVER THE COLD LAKE WATERS. && .AVIATION...ISSUED 1153 PM EST FRI MAR 4 2016 LIGHT SNOW MOVING IN FROM THE WEST AND STRATUS FROM THE SOUTH WILL HELP PRODUCE MVFR CONDITIONS DURING THE NIGHT AS THE NEXT LOW PRESSURE SYSTEM MOVES IN FROM THE MIDWEST. THERE COULD BE A BREAK IN SNOW SHOWERS OR A MIX OF DRIZZLE/FREEZING DRIZZLE DURING THE MORNING AS THE LOW APPROACHES. THIS COULD ALSO TURN OUT TO BE JUST FOG WITH ENOUGH UNCERTAINTY TO HOLD OFF ON FZDZ MENTION IN THE FORECAST FOR NOW. A RESURGENCE OF SNOW SHOWERS WITH IFR INTENSITY IS THEN EXPECTED DURING THE AFTERNOON...MAINLY SOUTH OF FNT THROUGH THE DTW AREA...AS THE LOW TRACKS NEAR TOLEDO. ACCUMULATION AROUND 1 INCH... LOCALLY 2 WHERE HEAVIER SNOW SHOWERS ARE MORE CONCENTRATED...REMAINS ON TARGET BEFORE THE SYSTEM EXITS SATURDAY EVENING. FOR DTW... A SLIGHTLY FASTER TREND FOR MVFR DEVELOPMENT IS EXPECTED MAINLY DUE TO STRATUS RETURNING NORTHWARD FROM OHIO...BUT ALSO WITH A FASTER ONSET OF SNOW. SNOW SHOWERS OFF AND ON DURING THE MORNING COULD ALSO BE MIXED WITH FOG OR FREEZING DRIZZLE. UPSTREAM TRENDS IN OBSERVATIONS WILL BE NEEDED TO REFINE THE POTENTIAL. AFTERNOON SNOW SHOWERS WILL HAVE GREATER INTENSITY WITH ABOUT 1 INCH OF ACCUMULATION BY SATURDAY EVENING. //DTW THRESHOLD PROBABILITIES... * MODERATE FOR CEILINGS AOB 5000 FEET OVERNIGHT. HIGH SATURDAY. * HIGH FOR SNOW AS PRECIPITATION TYPE TONIGHT THROUGH AFTERNOON. LOW FOR FREEZING DRIZZLE DURING THE MORNING. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ DISCUSSION...SC MARINE.......HLO AVIATION.....BT YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BISMARCK ND
344 AM CST SAT MAR 5 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 344 AM CST SAT MAR 5 2016 WARMER...BREEZY...AND DRY CONDITIONS HIGHLIGHT THE SHORT TERM PERIOD. SOUTHERLY WINDS/WARM AIR ADVECTION DEVELOP TODAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A MINOR COLD FRONT PASSES THROUGH SATURDAY NIGHT. THE LATEST WATER VAPOR AND IR IMAGERY LOOP INDICATE MID/UPPER LEVEL RIDGING OVER THE NORTHERN ROCKIES THIS MORNING WITH SCATTERED HIGH CLOUDS RIDING ATOP THE RIDGE INTO WESTERN NORTH DAKOTA. FOG/STRATUS IMAGERY LOOP CONTINUES TO SHOW AN AREA OF LOW CLOUDS IN THE JAMES RIVER VALLEY. THIS IS FORECAST TO EXIT BY 12Z SATURDAY. THE TREND WILL BE FOR THE UPPER RIDGE TO SHIFT EAST AND GRADUALLY FLATTEN/BECOME BROADER THROUGH TONIGHT...AS A PAIR OF SHORTWAVES PUSH INTO THE RIDGE. THE FIRST SHORTWAVE IS BEST DEFINED AT 700MB AND CURRENTLY IS LOCATED IN SOUTH CENTRAL MONTANA. THIS WILL STEADILY MOVE INTO SOUTH CENTRAL NORTH DAKOTA BY 00Z SUNDAY. NOT EXPECTING ANYTHING SIGNIFICANT AS THERE IS NO SURFACE LOW REFLECTION. THIS SHORTWAVE WILL MAINLY SERVE TO FLATTEN THE OVERALL HEIGHT FIELD/RIDGE AXIS AS IT PROPAGATES THROUGH. THE SECOND SHORTWAVE NOW INTO SOUTHWEST BRITISH COLUMBIA WILL SLIDE ACROSS SOUTHERN CANADA INDUCING A SURFACE LOW/COLD FRONT IN SOUTHERN ALBERTA THIS AFTERNOON. IT WILL THEN MOVE EAST AND GRAZE NORTH DAKOTA SATURDAY NIGHT WITH A WIND SHIFT AND WEAK COLD AIR ADVECTION. FOR TODAY...THE CANOPY OF THE 1000-500MB THICKNESS RIDGE HOVERS OVER THE SOUTHWEST...RESULTING IN THE WARMEST/DRIEST AIR TO RESIDE HERE. AFTERNOON HIGHS WILL CLIMB INTO THE MID/UPPER 60S SOUTHWEST. ELSEWHERE EXPECT HIGHS IN THE 50S CENTRAL TO 40S FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY. UTILIZED A 50/50 COMBINATION BLEND OF THE HRRR EXPERIMENTAL 2M HOURLY RH FIELD AND OFFICIAL GRIDDED FORECAST TO YIELD MINIMUM RELATIVE HUMIDITIES IN THE 15 TO 20 PERCENT RANGE SOUTHWEST. THIS SEEMS LOGICAL GIVEN UPSTREAM FLOW AND RELATED AIRMASS FROM FRIDAY HAVING ADVECTED IN FROM WYOMING. THE HRRR RH FIELD VERIFIED WELL IN NORTH DAKOTA AS WELL AS UPSTREAM IN THE LAST 24HR. WINDS TODAY WILL BE WEAKEST IN THE FAR SOUTHWEST WHERE AFTERNOON RELATIVE HUMIDITIES WILL BE LOWEST. WINDS WILL STEADILY INCREASE INTO THE BREEZY CATEGORY (15-25MPH) FOR CENTRAL NORTH DAKOTA THIS AFTERNOON. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 344 AM CST SAT MAR 5 2016 ABOVE-NORMAL TEMPERATURES AND MAINLY DRY WEATHER WILL PREVAIL FOR THE NEXT WEEK. ON SUNDAY...DAILY RECORD HIGHS MAY FALL GIVEN 850-MB TEMPERATURES IN THE 97.5 TO 99TH PERCENTILE FOR THIS TIME OF THE YEAR...NEARLY FULL SUNSHINE...DRY SOILS...AND DORMANT VEGETATION...ALL OF WHICH WILL SUPPORT EFFICIENT HEATING. WE ARE STILL CALLING FOR HIGHS IN THE 60S F IN MOST AREAS AND A FEW 70 F READINGS ARE LIKELY ACROSS SOUTHWEST AND SOUTH CENTRAL ND. MIXING IS FORECAST TO BE SOMEWHAT MORE SHALLOW THAN ON SATURDAY BASED ON 00 UTC MODEL SOUNDINGS AND THAT RAISES A BIT OF CONCERN FOR WARMING....BUT MORE THAN LIKELY THAT WILL JUST ENSURE WINDS WILL STAY RELATIVELY LIGHT. SUNDAY IS APT TO BE A TRULY STELLAR EARLY MARCH DAY. THEREAFTER...A PACIFIC COLD FRONT WILL CROSS THE AREA MONDAY AS A WEAK SHORTWAVE TROUGH EJECTS ACROSS THE REGION OUT OF A SPLITTING TROUGH THAT WILL KEEP ITS CORE WELL SOUTH IN TX AND MEXICO. WE DO HAVE A LOW-GRADE SHOWER CHANCE IN THE FORECAST BEHIND THE FRONT MONDAY THROUGH EARLY TUESDAY. PROGRESSIVE...QUASI-ZONAL FLOW WILL THEN OCCUR IN THE NORTHERN STREAM THE MIDDLE PART OF THE WEEK AND THAT WILL YIELD MAINLY DRY WEATHER. THE 00 UTC GFS AND ECMWF BOTH SUGGEST RIDGING REBUILDING AGAIN BY LATE WEEK....WITH THE 00 UTC NAEFS EVEN CALLING FOR 850-MB TEMPERATURE ANOMALIES IN THE 90TH PERCENTILE BY FRIDAY. THAT IS A SIGNIFICANT SIGNAL IN A LONG-LEAD ENSEMBLE FORECAST...SUGGESTING HIGHS COULD ONCE AGAIN END UP WELL INTO THE 60S F /WARMER THAN OUR CURRENT FORECAST/ BY LATE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY) ISSUED AT 344 AM CST SAT MAR 5 2016 MVFR CIGS AT KJMS WILL LIFT TO VFR BY 12Z SATURDAY. VFR CIGS/VSBYS THEREAFTER AND ACROSS ALL OTHER TERMINALS THROUGH 12Z SUNDAY. BREEZY SOUTHERLY WINDS 15-25KT SATURDAY WILL BECOME WEST AT 5-10KT AFTER 06Z SUNDAY AS A WEAK COLD FRONT SLIDES THROUGH. && .FIRE WEATHER... ISSUED AT 344 AM CST SAT MAR 5 2016 IT APPEARS RIGHT NOW THE PROJECTED FIRE DANGER WILL BE IN THE HIGH CATEGORY ACROSS SOUTHWEST NORTH DAKOTA TODAY. DESPITE MINIMUM RELATIVE HUMIDITIES IN THE 15 TO 20 PERCENT RANGE...WINDS WILL BE LACKING FOR CRITICAL FIRE WEATHER CRITERIA BEING MET. SUSTAINED SOUTHERLY WINDS WILL WEAKEN THROUGH THE AFTERNOON TO BETWEEN 10 AND 15 MPH...JUST AS RELATIVE HUMIDITIES REACH THEIR MINIMUM AS MENTIONED ABOVE. THUS WILL NOT ISSUE ANY HIGHLIGHTS AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KS LONG TERM...CJS AVIATION...KS FIRE WEATHER...KS
AREA FORECAST DISCUSSION...CORRECTED
NWS PORTLAND OR
934 PM PST FRI MAR 4 2016 .SYNOPSIS...A STRONG BUT SLOW MOVING FRONT REMAINS JUST OFF THE COAST...YIELDING A MOSTLY DRY EVENING FOR THE FORECAST AREA. THIS FRONT WILL CONTINUE TO SLOWLY MOVE TOWARD THE COAST TONIGHT... EVENTUALLY SPREADING RAIN ACROSS THE FORECAST AREA LATER TONIGHT AND SATURDAY MORNING. THE FRONT IS ALSO BRINGING STRONG WINDS TO THE COASTAL WATERS...WHICH WILL BRIEFLY IMPACT THE IMMEDIATE COAST LATER TONIGHT. A STRONGER LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP OFFSHORE SATURDAY...BRINGING MORE RAIN AND GUSTY WINDS BY SATURDAY EVENING. COOLER AIR BEHIND THIS SYSTEM WILL CAUSE SNOW LEVELS TO LOWER TO THE CASCADE PASSES FOR A FEW INCHES OF ACCUMULATION BY SUNDAY MORNING. SHOWERS CONTINUE SUNDAY AND MONDAY WITH POSSIBLY AN AFTERNOON THUNDERSTORM OR TWO. ADDITIONAL WET WEATHER WILL LIKELY ARRIVE TOWARDS THE MIDDLE TO LATTER HALF OF NEXT WEEK. && .SHORT TERM...TONIGHT THROUGH MONDAY...WINDS REMAIN GENERALLY LIGHT ALONG THE COAST SO FAR THIS EVENING...A STARK CONTRAST FROM THE GALE FORCE WINDS OCCURRING JUST OFFSHORE. THE DELAY IN WINDS HAS LARGELY BEEN DUE TO THE DEVELOPMENT OF A WEAK WAVE OF LOW PRESSURE NEAR 40N/127W WHICH IS KEEPING PRESSURE GRADIENTS UNFAVORABLE FOR STRONG WINDS ALONG THE COAST. THIS WAVE OF LOW PRESSURE IS BECOMING ABSORBED INTO THE FRONT...WITH THE REMNANT IMPULSE FORECAST BY THE 00Z NAM AND UW WRF-GFS TO LIFT NORTH ALONG THE OREGON COAST OVERNIGHT TONIGHT. THIS COULD YIELD A BRIEF PERIOD WHERE WINDS REACH 55-65 MPH ALONG THE BEACHES AND HEADLANDS...WHILE THE COASTAL COMMUNITIES SEE MUCH LIGHTER WINDS. REGARDLESS...CONFIDENCE IS DWINDLING A BIT ON WHETHER OR NOT THE HIGH WIND WARNING WILL VERIFY TONIGHT. HOWEVER CONFIDENCE THAT IT WILL NOT VERIFY IS NOT NEARLY HIGH ENOUGH TO CANCEL AN EXISTING WARNING AT THIS POINT. THE SAME WAVE OF LOW PRESSURE HOLDING UP THE WINDS ALONG THE COAST HAS ALSO ALLOWED A MAINLY DRY EVENING ACROSS THE FORECAST AREA ASIDE FROM SOME SPRINKLES HERE AND THERE. IN FACT...NO RAWS OR ASOS STATIONS HAVE REPORTED MEASURABLE PRECIPITATION IN THE PAST HOUR IN OUR CWA. ISSUED A QUICK UPDATE EARLIER TO DECREASE POPS EAST OF THE COAST RANGE THIS EVENING. 03Z HRRR AND 00Z NAM/GFS STILL SUGGEST THE FRONT WILL MAKE ENOUGH PROGRESS TOWARD THE COAST TO SPREAD RAIN INLAND LATER TONIGHT AND SAT MORNING. THE EXISTING FRONT WILL LIKELY STRETCH AND WEAKEN CONSIDERABLY WHILE OVER WESTERN WA/OR SAT. THE FRONT WILL LIKELY LEAVE BEHIND PLENTY OF LOW-LEVEL MOISTURE... AND THERE MAY BE ENOUGH SUN BREAKS OR THINNING IN CLOUD COVER TO ALLOW SFC TEMPS TO REACH A POINT WHERE THE AIR MASS WILL BE CONDITIONALLY UNSTABLE UP TO 25 KFT OR SO. WITH STRONG FORCING EXPECTED TO ARRIVE IN THE FORM OF A DEVELOPING LOW AND NEGATIVELY- TILTED COLD FRONT...DECIDED IT WOULD BE PRUDENT TO ADD A THUNDER MENTION TO THE ENTIRE CWA SAT AFTERNOON AND EVENING. ALSO ADJUSTED TEMPS UPWARDS BY A FEW DEGREES AS THE 00Z GFS SHOWS A THERMAL RIDGE OF 850 MB TEMPS +8 TO +10 DEG C SPREADING UP NORTH THROUGH THE WILLAMETTE VALLEY SAT AFTERNOON. BARRING A COMPLETELY CLOUDY DAY WITH NO SUNBREAKS AT ALL...THIS SHOULD ALLOW MOST LOWLAND LOCATIONS TO REACH 60 DEGREES SAT AFTERNOON. AS MENTIONED ABOVE...THESE WARMER SFC TEMPS WILL ASSIST ANY SFC-BASED CONVECTION THAT TRIES TO DEVELOP ALONG/AHEAD OF THE COLD FRONT COMING IN FROM THE SOUTHWEST. THE DEVELOPING LOW MENTIONED ABOVE IS SHOWING MORE AND MORE INDICATION THAT IT IS GOING TO BE THE BIG DOG OF THIS SERIES OF LOWS BRUSHING THE PAC NW COAST. A VERY WELL-DEFINED NORTHERN STREAM SHORTWAVE IS EASILY VISIBLE ON WATER VAPOR SATELLITE IMAGERY NEAR 40N/145W. A STRONG PUSH OF COLD AIR BEHIND THIS SYSTEM IS TIGHTENING THE BAROCLINICITY...WHILE A 160-180 KT JET STREAM FEEDS INTO THIS SYSTEM. ALL THE INGREDIENTS ARE THERE FOR RAPID CYCLOGENESIS...AND THE 00Z GFS SHOWS THIS NICELY IN DEVELOPING A 975 MB LOW NEAR 45N/130W BY SAT AFTERNOON WHICH EVENTUALLY BECOMES A 965 MB PARENT LOW NEAR HAIDA GWAII BY SUN AFTERNOON. MEANWHILE...COLD AIR WILL CONTINUE TO UNDERCUT THE LOW...DRIVING A STRONG AND VERY SHARP COLD FRONT INTO THE OREGON COAST LATE SAT AFTERNOON OR SAT EVENING. THE 00Z NAM DEVELOPS ANOTHER SUB-980 MB LOW ALONG THE FRONT NEAR THE OREGON COAST...WHICH IS POSSIBLE BUT THE DETAILS ARE LIKELY IMPOSSIBLE FOR THE MODEL TO RESOLVE AT THIS POINT. EITHER WAY...STRONG COLD ADVECTION FROM THE SOUTHWEST AND PRESSURE RISES BEHIND THE FRONT ARE LOOKING INCREASINGLY FAVORABLE FOR WINDY CONDITIONS NOT JUST ALONG THE COAST...BUT INLAND AS WELL SAT EVENING. WOULD NOT BE SURPRISED IF WE END UP WITH LOW-END ADVISORY GUSTS IN THE WILLAMETTE VALLEY... THOUGH THIS IS NOT SHOWN AT THIS POINT BY EITHER THE 00Z NAM OR UW WRF. WILL HOLD GUSTS JUST BELOW ADVISORY CRITERIA FOR NOW...WITH 30-40 MPH GUSTS IN THE WILLAMETTE VALLEY. THE HIGH WIND WATCH FOR THE COAST SATURDAY NIGHT STILL LOOKS GOOD. GIVEN THE TRAJECTORY OF THE LOW...GRADIENTS WILL PROBABLY NOT BE FAVORABLE FOR STRONG WINDS UNTIL THE FRONT ARRIVES. HOWEVER A STRONG SURGE OF WIND IS LIKELY ALONG AND AHEAD OF THE FRONT...NOT JUST FOR THE BEACHES AND HEADLANDS BUT FOR THE COASTAL COMMUNITIES AS WELL. JUST HOW STRONG WILL DEPEND LARGELY ON THE TRACK OF THE PARENT LOW AND IF/WHEN/WHERE ANY SECONDARY LOWS DEVELOP. GIVEN THE COLD AIR PUSHING IN BEHIND THE FRONT...THIS APPEARS TO BE THE TYPE OF EVENT WHICH UNDERPERFORMS FOR THE BEACHES AND HEADLANDS BUT OVERPERFORMS ELSEWHERE. SNOW LEVELS WILL LOWER DRAMATICALLY IN THE COLD AIR BEHIND THE FRONT SAT NIGHT/SUN. MEANWHILE COLD AIR ALOFT WILL KEEP THE AIR MASS UNSTABLE WITH COOL SHOWERS AND ISOLATED THUNDERSTORMS LINGERING THROUGH MONDAY. A FEW INCHES OF SNOW WILL LIKELY ADD UP IN THE CASCADES BY MONDAY. SOME MODELS HINT AT THE POTENTIAL FOR YET ANOTHER LOW TO DEVELOP TO OUR SOUTHWEST SUN NIGHT...BUT GIVEN THE MAGNITUDE OF COLD ADVECTION BEHIND SAT EVENINGS FRONT...IT APPEARS ANY STRONG LOW THAT WOULD DEVELOP BY THEN WOULD LIKELY STAY WELL TO OUR SOUTH. ALL IN ALL...AN INTERESTING PATTERN FOR STORMWATCHERS THE NEXT SEVERAL DAYS. WEAGLE .LONG TERM...MONDAY NIGHT THROUGH FRIDAY...AN UPPER LEVEL TROUGH AND ONSHORE FLOW WILL CONTINUE SHOWERS MONDAY NIGHT. TUESDAY MORNING WILL BE BETWEEN SYSTEMS WITH SHOWERS RAPIDLY DECREASING UNDER BRIEF RIDGING. THE NEXT PACIFIC FRONT WILL BRING A RETURN OF RAIN AND MOUNTAIN SNOW TUESDAY AFTERNOON WITH SNOW LEVELS AROUND 3500 FEET. THERE IS POTENTIAL FOR AN ATMOSPHERIC RIVER EVENT WEDNESDAY AND THURSDAY WITH A SURFACE LOW (AND ASSOCIATED FRONT) TAPPING INTO A SWATH OF 1.10 TO 1.4 INCHES OF PRECIPITABLE WATER. INTEGRATIVE VAPOR TRANSPORT SHOWS THE BEST CHANCE FOR HEAVY RAIN ACROSS SW OREGON...BUT THINK NW OREGON AND SW WASHINGTON CAN STILL GET A DECENT SOAKING. SNOW LEVELS WILL INITIALLY START AROUND 3500 FEET TUESDAY NIGHT...THEN RAPIDLY RISE TO AROUND 5500 FEET WEDNESDAY. TJ && .AVIATION...A FRONT AND BAND OF RAIN WILL PUSH ONSHORE OVERNIGHT AND BRING A DETERIORATION TO MVFR FLIGHT CONDITIONS TO MANY TAF SITES BETWEEN 06Z AND 12Z MONDAY. INCREASING OFFSHORE FLOW SHOULD TURN CONDITIONS PREDOMINANTLY VFR AREA WIDE AFTER 12Z SATURDAY. ANOTHER LOW PRESSURE SYSTEM THAT WILL LIKELY BRING STRONGER WINDS REGION WIDE SATURDAY EVENING WITH GUSTS UP TO 50 KT POSSIBLE ALONG THE COAST AND 35 KT ACROSS THE INTERIOR. THIS SYSTEM WILL ALSO LIKELY PRODUCE A PERIOD OF FLIGHT RESTRICTIONS FOR COASTAL LOCATIONS BETWEEN 00Z AND 06Z SUNDAY. KPDX AND APPROACHES...EXPECT PREDOMINATELY VFR CONDITIONS THROUGH 06Z SUNDAY AS A SERIES OF LOW PRESSURE SYSTEMS KEEP EAST TO SOUTH WINDS ELEVATED. HOWEVER...A PERIOD OF STEADIER RAIN LATER TONIGHT SHOULD BE ENOUGH TO PRODUCE A BRIEF PERIOD OF MVFR CONDITIONS...MOST LIKELY BETWEEN 09Z AND 12Z SATURDAY. /NEUMAN && .MARINE...SEVERAL SURFACE LOW PRESSURE SYSTEMS DEVELOPED THIS AFTERNOON AND ARE MOVING NORTHEASTWARD TOWARDS THE PACIFIC NORTHWEST. WHILE EACH STORM SYSTEM IS NOTABLE...THIS HAS LIKELY PREVENTED A WORST CASE SCENARIO FROM UNFOLDING. NONETHELESS...GALE FORCE WIND GUSTS ARE CURRENTLY BEING OBSERVED ACROSS THE WATERS...AND EXPECT THESE TO CONTINUE FOR THE NEXT SEVERAL HOURS BEFORE WEAKENING AFTER MIDNIGHT. WILL KEEP THE CURRENT STORM WARNING GOING DUE TO AN INHERENT UNCERTAINTY WITH THIS TYPE OF SYSTEM...BUT LATEST TRENDS IN OBSERVATIONS AND MODEL GUIDANCE ARE NOT PROMISING. EXPECT WINDS AND SEAS TO SUBSIDE AFTER MIDNIGHT WITH SEAS LIKELY DROPPING INTO THE LOW TO MID TEENS SATURDAY MORNING THROUGH AT LEAST EARLY SATURDAY AFTERNOON. HOWEVER...THE LULL IN WINDS AND SEAS WILL BE SHORT LIVED AS THE NEXT STORM SYSTEM PRODUCES ANOTHER SET OF STRENGTHENING SURFACE LOW PRESSURES AND STRONGER WINDS AND HIGH SEAS ACROSS THE WATERS. THERE IS CERTAINLY POTENTIAL FOR STORM FORCE GUSTS...BUT SUSPECT WIND GUSTS WILL GENERALLY REMAIN IN SOLID GALE FORCE CRITERIA OF 40 TO 45 KT. AT THIS POINT...THE STRONGEST WINDS AND ABRUPT RISE IN SEAS WILL LIKELY BEGIN ACROSS THE CENTRAL OREGON WATERS BETWEEN 3 PM AND 6 PM AND BETWEEN 6 PM AND 9 PM ACROSS THE NORTHERN WATERS. WINDS AND SEAS WILL LIKELY REMAIN ELEVATED THROUGH SUNDAY WITH A SMALL CHANCE THAT ANOTHER SURFACE LOW PRESSURE COULD IMPACT THE REGION. HOWEVER...IT APPEARS THIS SYSTEM WILL MOST LIKELY STAY SOUTH OF THE REGION SUNDAY AFTERNOON/EVENING. ANOTHER FRONT TUESDAY-ISH HAS THE POTENTIAL TO BRING ANOTHER ROUND OF GALE FORCE WINDS...WITH PERHAPS A STRONGER STORM SYSTEM WEDNESDAY. SEAS LOOK TO REMAIN ABOVE 10 FT FOR AT LEAST THE NEXT WEEK...AND MAY EXCEED 20 FT BY QUITE A BIT TOWARDS THE MIDDLE OF NEXT WEEK. /NEUMAN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...HIGH WIND WARNING UNTIL 4 AM PST SATURDAY FOR CENTRAL OREGON COAST-NORTH OREGON COAST. HIGH SURF ADVISORY UNTIL 3 AM PST SATURDAY FOR CENTRAL OREGON COAST-NORTH OREGON COAST. HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY NIGHT FOR CENTRAL OREGON COAST-NORTH OREGON COAST. WA...HIGH WIND WARNING UNTIL 4 AM PST SATURDAY FOR SOUTH WASHINGTON COAST. HIGH SURF ADVISORY UNTIL 3 AM PST SATURDAY FOR SOUTH WASHINGTON COAST. HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY NIGHT FOR SOUTH WASHINGTON COAST. PZ...GALE WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. STORM WARNING UNTIL 1 AM PST SATURDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. STORM WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM PST SUNDAY. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
215 AM EST SAT MAR 5 2016 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL MOVE THROUGH THE REGION EARLY TODAY...BEFORE ANOTHER WEAK CLIPPER TYPE SYSTEM BRINGS THE CHANCE FOR MORE LIGHT RAIN OR SNOW LATER TODAY INTO SUNDAY MORNING. A LARGE RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN HALF OF THE CONTINENT DURING THE UPCOMING WEEK. TEMPERATURES WILL SURGE TO WELL ABOVE NORMAL LEVELS STARTING MONDAY...AND LAST THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... IR LOOP AT 0630Z SHOWS EXTENSIVE STRATOCU DECK HOLDING TOUGH ACROSS MUCH OF THE FCST AREA TO THE WEST OF THE SUSQUEHANNA`S MAINSTEM. MID LEVEL WARM ADVECTION WILL BRING A SHIELD OF ALTOCU/ALOTSTRATUS ACROSS THE REGION DURING THE MID TO LATE MORNING. EXPECT EARLY MORNING LOWS IN THE MID TO UPPER TEENS TO BE COMMON ACROSS THE N MTNS. MORE PERSISTENT CLOUD COVER SHOULD RESULT IN LOWS MAINLY THE L-M20S ACROSS THE REMAINDER OF CENTRAL/SOUTHERN PA. SOME SPOTS IN SCENT PENN WILL HAVE TROUBLE SLIPPING BELOW 27F. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SUNDAY/... ANY EARLY SUNSHINE TODAY /MAINLY ACROSS THE SUSQ VALLEY AND POINTS EAST OF THE STUBBORN STRATOCU DECK/ WILL FADE BEHIND THICKENING CLOUDS BY LATE THIS MORNING...AS A CLIPPER DIVES SE FROM THE GRT LKS. IT WILL STAY DRY ACROSS ALL BUT THE NW MTNS THROUGH THE MIDDAY HOURS. INVOF KBFD AND POINTS WEST...SOME FLURRIES COULD DEVELOP AROUND 15Z...BUT THE 05Z HRRR AND PRIOR RUNS HAVE INDICATED THAT THIS INITIAL BATCH OF VERY LIGHT QPF FIZZLES OUT ACROSS THE NW MTNS...WITH ESSENTIALLY DRY CONDITIONS OVER THE ENTIRE REGION THROUGH AT LEAST 20Z. THE BULK OF THE LIGHT SNOW /WITH THE EMPHASIS ON THE WORD LIGHT/ WILL ARRIVE VERY LATE TODAY ACROSS THE WEST...AND EARLY TONIGHT ACROSS CENTRAL AND ERN PENN WITH THE PASSAGE OF A WEAK /1016-1018 MB/ SFC LOW AND ASSOC WEAK WAA. CONSENSUS MODEL QPF IS JUST A FEW...TO SVRL HUNDREDTHS OF AN INCH...WHICH LEADS TO SNOWFALL AMOUNTS SIMILAR...IF NOT LIGHTER IN MOST AREAS THAN WHAT OCCURRED ABOUT 48 HOURS PRIOR - THURSDAY NIGHT INTO FRIDAY MORNING. THE LAURELS COULD BE THE EXCEPTION WITH THE POTENTIAL FOR AN INCH OR TWO OF SNOW ACCUMULATION BY EARLY SUNDAY...CONSIDERING THIS AREA WILL BE CLOSEST TO THE SFC LOW TRACK ACROSS WEST VA. NATIONAL BLEND COMBINED WITH INPUT FROM LATEST LAMP SUPPORT MAX TEMPS THIS AFTERNOON IN THE L30S OVR THE HIGHEST TERRAIN OF THE ALLEGHENIES...TO ARND 40F ACROSS THE SUSQ VALLEY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... MEDIUM RANGE PORTION OF THE FORECAST CONTINUES TO HAVE A FAIR AMOUNT OF AGREEMENT IN MODEL SOLUTIONS...AS A WEAK CLIPPER SLIDES THROUGH SAT INTO EARLY SUN. STILL LOOKING AT A RELATIVELY WEAK AND DEFINITELY MOISTURE-STARVED SYSTEM...WITH MEAN QPF SUPPORTING A 1-2 INCH SNOWFALL WITH THE W MTNS CLIMATOLOGICALLY FAVORED FOR THE HIGHEST AMTS. THE BEST CHANCES FOR PRECIP FROM MDL TIMING OF WEAK SFC REFLECTION SUGGEST THE STEADIEST SNOW SHOULD FALL SAT NIGHT. SOME BRIEFLY MDT SNOW RATES ARE POSSIBLE FROM THE LAURELS...INTO SOUTH CENTRAL PENN SATURDAY NIGHT AS SOME FLEETING BANDS OF MID LEVEL FRONTOGENESIS DEVELOP/DRIFT ESE. HOWEVER...MOST OF THE SNOW WILL BE VERY LIGHT /SIMILAR TO THU NIGHT AND EARLY FRIDAY/ AS THE FAVORABLE THERMAL RIBBON FOR DENDRITIC SNOW GROWTH STAYS BETWEEN 7-11 KFT AGL AND WEAK OMEGA COINCIDES WITH IT. THE BEST PERIOD FOR A LIGHT SNOW ACCUMULATION OF AROUND AN INCH OR SO WILL BE IN THE 06-12Z SUNDAY PERIOD. BRIGHTENING SKIES BUT STILL CHILLY WX ANTICIPATED SUNDAY...AS HIGH PRES BUILDS IN FROM THE WEST WITH LIGHT NW FLOW. WIDE CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP NEXT WEEK...AS ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 12Z ECENS. TEMPS WILL TAKE A RUN AT 70F BY WED OVR SOUTHERN PA. MODELS ARE IN BETTER AGREEMENT ON BRINGING A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF THROUGH PA BY MIDWEEK...AS HIGH PRESSURE TRACKING EASTWARD ACROSS CANADA WILL NUDGE THE FRONT SOUTHWARD AND PIVOT IT FROM MORE OF A N-S ORIENTATION TO A W-E DIRECTION. THIS COULD BRING THE NEXT BEST CHANCE FOR PRECIPITATION AS WEAK WAVES COULD RIPPLE TOWARD PA ALONG THE PORTION OF THE /WARM/ FRONT OVER THE OHIO VALLEY. GIVEN THE STRONG WAA IT LOOKS TO BE ALL RAIN...WITH PRECIP BRACKETED BETWEEN LATE IN THE DAY WED AND FRI. THE GFS IS MORE AGGRESSIVE WITH ONSET OF PRECIP AND QPF AMOUNTS THAN THE ECMWF...BUT EITHER WAY IT LOOKS TO BE A SHOWERY END TO THE WEEK AND TEMPS GRADUALLY COOL BACK DOWN BUT REMAIN ABOVE NORMAL. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... FOR THE 05/06Z TAFS THROUGH 06/06Z ISSUED AT 135 AM EST SAT MAR 5 2016 LOW CLOUDS TRAPPED UNDERNEATH SUBSIDENCE INVERSION WILL KEEP MVFR TO LOW VFR CIGS /1.5-4KFT AGL/ IN PLACE THIS MORNING ACROSS THE WRN 2/3 OF THE AIRSPACE. VFR ALONG/EAST OF IPT-MDT LINE WITH FEW- SCT CIGS AT 5KFT. LOW PRESSURE TRACKING SOUTHEAST FROM WI THRU WV WILL BRING LIGHT SNOW AND REDUCED CONDITIONS LATER THIS AFTERNOON INTO TONIGHT. HIGHEST CONFIDENCE IN IFR IS AT JST. OUTLOOK...SUNDAY-WEDNESDAY SUN...MVFR CIGS WEST BECOMING VFR. NO SIG WX. MON-TUE...VFR/NO SIG WX. WED...VFR. RAIN POSSIBLE NORTHWEST AIRSPACE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT/FITZGERALD LONG TERM...RXR AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
248 AM EST SAT MAR 5 2016 .SHORT TERM (TODAY AND TONIGHT)... CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A TROUGH ACROSS THE NORTHERN MISSISSIPPI RIVER VALLEY WITH NORTHWESTERLY FLOW ACROSS THE FORECAST AREA. THIS TROUGH WILL BE THE MAIN FEATURE FOR THE SHORT-TERM FORECAST. AT THE SURFACE... HIGH PRESSURE IS IN PLACE WITH CALM WINDS AND MOSTLY CLEAR SKIES. DUE TO THIS RADIATIONAL COOLING...COULD SEE SOME AREAS OF PATCHY FOG THIS MORNING BUT NOT EXPECTING ANYTHING WIDESPREAD OR DENSE ENOUGH TO ISSUE AN ADVISORY. ANY SHALLOW FOG THAT DOES FORM WILL MIX OUT QUICKLY THIS MORNING WITH MOSTLY SUNNY SKIES EXPECTED THROUGHOUT MUCH OF THE MORNING. FURTHER TO THE WEST...A SURFACE LOW CAN BE NOTED ACROSS THE UPPER MISSISSIPPI RIVER VALLEY WITH A COLD FRONT EXTENDING SOUTHWESTWARD INTO THE SOUTHERN PLAINS. THE AFOREMENTIONED TROUGH WILL DIVE SOUTHEASTWARD INTO THE OHIO RIVER VALLEY WITH CLOUDS INCREASING ACROSS THE NORTHERN COUNTIES LATE IN THE MORNING. PW VALUES ARE A BIT MORE IMPRESSIVE THAN IN PREVIOUS MODEL RUNS WITH VALUES IN THE 0.5-0.6 INCH RANGE. THESE VALUES ARE RIGHT AROUND TO JUST ABOVE AVERAGE FOR EARLY MARCH. MODEL SOUNDINGS SUPPORT ENOUGH SATURATION FOR LIGHT PRECIPITATION TO DEVELOP THIS AFTERNOON WITH THE NORTHERN HALF OF THE AREA HAVING THE HIGHEST CHANCES. THE COLD FRONT WILL MOVE THROUGH THE AREA BETWEEN 00-06Z WITH COLDER AIR IN THE LOW LEVELS MOVING IN BEHIND THE FRONT. LATEST MODEL GUIDANCE SUGGEST ENOUGH MOISTURE LEFT OVER FOR A FEW SNOW SHOWERS/FLURRIES FOR ELEVATIONS ABOVE 3 KFT LATE TONIGHT. HOWEVER...THE MOISTURE IS LIMITED AND DO NOT EXPECT ANY ACCUMULATIONS WOULD APPROACH ADVISORY LEVEL CRITERIA. .LONG TERM (SUNDAY THROUGH FRIDAY)... STRONG RIDGE BUILDS IN ACROSS THE SOUTHERN APPALACHIAN REGION EARLY IN THE EXTENDED. THIS WILL USHER IN DRY...WARM CONDITIONS. A STRONG WARMING TREND SUNDAY AND MONDAY WILL CULMINATE WITH TEMPERATURES REACHING INTO THE UPPER 60S AND 70S TUESDAY AND WEDNESDAY. THE RIDGE SHIFTS EAST OF THE REGION THURSDAY AND FRIDAY...ALLOWING A SYSTEM THAT HAS BEEN STALLED OVER THE WEST TN AREA TO MOVE IN. MODELS IN POOR AGREEMENT ON DETAILS BY THE END OF THE PERIOD....BUT WEDNESDAY NIGHT INTO THURSDAY...CLOUDS WILL INCREASE AND SCATTERED RAIN SHOWERS WILL MOVE IN. AS THE BOUNDARY AND UPPER TROUGH MOVE THROUGH AROUND FRIDAY TIME FRAME...THE SHOWERS WILL BECOME WIDESPREAD AND COULD SEE ISOLATED THUNDERSTORMS DEVELOP BY THE END OF THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 62 35 63 41 / 10 0 0 0 KNOXVILLE MCGHEE TYSON AIRPORT, TN 55 35 56 37 / 20 30 0 0 OAK RIDGE, TN 56 35 56 37 / 30 30 0 0 TRI CITIES AIRPORT, TN 51 33 53 33 / 60 60 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ MA/MJB
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
544 AM PST SAT MAR 5 2016 ...HEAVY RAIN LATER THIS AFTERNOON AND EVENING... ...MODERATE RAIN EVENT SUNDAY NIGHT WITH NEXT FRONT... .SYNOPSIS...PERIODS OF RAIN...MAINLY LIGHT THIS MORNING. RAIN WILL THEN INCREASE AND BECOME MODERATE TO HEAVY AFTER 2 PM AS A STRONG COLD FRONT APPROACHES THE BAY AREA. PERIODS OF HEAVY RAIN THIS EVENING WITH GUSTY SOUTHERLY WINDS. WIND AND RAIN WILL RAPIDLY WIND DOWN BEFORE MIDNIGHT. SHOWERS AND ISOLATED THUNDERSTORMS SUNDAY IN POST FRONTAL ENVIRONMENT. NEXT FRONT ARRIVES SUNDAY NIGHT WITH ANOTHER ROUND OF MODERATE RAINS. SHOWERS LINGER MONDAY THEN DRY THROUGH MIDWEEK. CHANCE OF NORTH BAY RAIN BY WEDNESDAY THEN ALL OF THE BAY AREA AND CENTRAL COAST BY THURSDAY AND FRIDAY. && .DISCUSSION...AS OF 4:04 AM PST SATURDAY...ISSUED A PNS AT 3 AM WITH LATEST 24 HOUR RAINFALL TOTALS. RADAR SHOWS OVERNIGHT STEADY RAINFALL MOVING EASTWARD BUT MORE RETURNS STARTING TO DEVELOP WELL OFFSHORE. WERE STILL IN THE WARM ADVECTION ENVIRONMENT WITH MAINLY LIGHT AND PERIODIC RAINFALL THROUGH LUNCH TIME TODAY. IR SATELLITE OVER THE LAST 6 HOURS OR SO IS SHOWING A BAROCLINIC LEAF CLOUD BLOWING UP OUT NEAR 130W/36N...EVIDENCE OF STRONG INCOMING JET STREAK AND STRENGTHENING SURFACE COLD FRONTAL BOUNDARY. THIS IS THE FEATURE THE MODELS HAVE BEEN HONING IN ON NOW FOR NEARLY THE LAST WEEK. FEATURE WILL QUICKLY APPROACH THE COAST TODAY AND EXPECT MODERATE RAINS TO START IN EARNEST AROUND 2 PM OR SO OVER MUCH OF THE GREATER BAY AREA. LOCAL HILLS SUCH AS BIG SUR AND SANTA CRUZ MOUNTAINS WILL SEE PERIODS OF RAIN THROUGH MOST OF THE DAY. ANYWAY THE HIGHLY ANTICIPATED FRONTAL PASSAGE SHOULD BE OBVIOUS FROM ROUGHLY 3 PM TO 8 PM LOCAL TIME WHEN VERY STRONG WINDS AND HEAVY RAIN OCCUR OVER A SEVERAL HOUR WINDOW OF TIME. DO EXPECT SOME PREFRONTAL SOUTHERLY WIND GUSTS TO SHOW UP AS EARLY AS LUNCH TIME AND CURRENT TIMING OF WIND ADVISORY TO START THEN STILL LOOKS GOOD. SANTA CRUZ MOUNTAINS OFTEN SEE WIND DAMAGE AND LINES DOWN IN THESE TYPE OF PATTERNS AS SYNOPTIC FLOW AND STRONG SOUTHEAST WINDS FLOWING OUT OF SALINAS VALLEY FOCUS UP THERE. ANYWAY THE HRRR AND RAP SHORT TERM MESOSCALE MODELS ARE IN AGREEMENT THAT THE HEAVIEST RAINS FALL FROM ROUGHLY 4 TO 8 PM THIS EVENING (EARLIEST IN THE NORTH BAY AND LATEST IN MONTEREY BAY REGION). STORM TOTALS FROM NOW THROUGH ABOUT 10 PM TONIGHT SHOULD BRING 1-2 INCHES TO THE LOWER ELEVATIONS WITH 2-5 INCHES FOR THE NORTH BAY/SANTA CRUZ AND SANTA LUCIA HILLS. (USUAL DRY SPOTS IN THE SALINAS AND EAST BAY VALLEYS WILL BE UNDER AN INCH). THIS STORM WILL CAUSE ISSUES TONIGHT THROUGHOUT THE BAY AREA WITH TRAFFIC...LOCALIZED FLOODING DUE TO THE HEAVY RAIN RATES OVER A SHORT WINDOW OF TIME AND ASSOCIATED WIND DAMAGE ISSUES. A DISTINCT LULL IN THE ACTION WILL OCCUR AFTER MIDNIGHT BEHIND THE FRONT WITH ONLY SOME LINGERING SHOWERS AND MUCH LIGHTER SW WINDS. SHOWER AND POST FRONTAL T-STORMS POSSIBLE ON SUNDAY BUT PARTLY CLOUDY SKIES WILL PREVAIL FOR MANY AREAS SOUTH OF SAN FRANCISCO ON SUNDAY. NEXT SYSTEM APPROACHING WILL BRING GENTLE WARM ADVECTION RAINS TO THE NORTH BAY BY SUNDAY AFTERNOON. THEN ON SUNDAY NIGHT POTENT SHORTWAVE WITH MUCH COLDER AIR ALOFT WILL PASS FROM NW TO SE ACROSS THE DISTRICT. ANOTHER ROUND OF SOME HEAVY RAIN SHOWERS WITH POSSIBLE T-STORMS WILL OCCUR. RAIN TOTALS WILL BE LESS WITH THIS SYSTEM BUT SOME LOCALIZED HEAVY RAINFALL SHOULD BE EXPECTED. LOOKS LIKE THE BULK OF THE HEAVY RAIN IS DONE BY 12Z MONDAY WITH ONLY SOME LINGERING RAINS SHOWERS BY 15Z MONDAY FOR THE MORNING COMMUTE. HOWEVER EVEN A WET START TO THE COMMUTE IS OFTEN ENOUGH TO THROW THINGS INTO DISARRAY TO START OUT THE WORK WEEK. SIMILAR TO SUNDAY...SHOWERS CHANCES WILL LINGER MONDAY BUT BE ON THE DECREASE THROUGH THE DAY. LOOKS DRY MONDAY NIGHT AND TUESDAY. LATEST ECMWF HAS TRENDED WETTER BY WEDS FOR THE NORTH BAY WITH SOME WARM FRONTAL LIGHT RAIN CHANCES. MORE ORGANIZED COLD FRONT THEN ARRIVES LATER THURSDAY INTO FRIDAY. WILL HONE IN ON THOSE DETAILS AFTER WE GET THROUGH THE WEEKEND SYSTEMS BUT THE STORMS LATER NEXT WEEK LOOK MODERATE IN STRENGTH/INTENSITY. && .AVIATION...AS OF 5:44 AM PST SATURDAY...A STRONG COLD FRONT WILL SWEEP EAST OVER THE AREA THIS EVENING. THIS FRONTAL PASSAGE HAS THE POTENTIAL TO BE THE STRONGEST WE`VE SEEN THIS WINTER SEASON. DETERIORATING WX CONDITIONS TODAY WITH MODERATE-HEAVY RAIN AND HEAVY S-SE WIND COMBINED UP TO THE FRONTAL PASSAGE THIS EVENING. WORTH NOTING PRE-FRONTAL S-SE WINDS OFTEN CAUSES A RAIN SHADOW FOR PLACES LIKE THE SOUTH BAY AND THE MONTEREY PENINSULA THUS THE RAIN MAY AT TIMES BECOME MORE PERIODIC TODAY IN PLACES THAT ARE IN THE LEE OF HIGHER TERRAIN. SHOWERY COLDER MORE UNSTABLE AIR ARRIVES LATE TONIGHT AND SUNDAY. VICINITY OF KSFO...AIRPORT WEATHER WARNING ISSUED FOR STRONG AND GUSTY S-SE WINDS. MVFR CIGS. RAIN. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS. STRONG AND GUSTY SOUTHERLY WINDS DEVELOPING TODAY. RAIN. && .BEACHES...AS OF 5:30 AM PST SATURDAY...A HIGH SURF ADVISORY BEGINS 10 PM TONIGHT AND LASTS INTO TUESDAY MORNING. WESTERLY SWELL WILL BE PEAKING CLOSE TO 20 FEET WITH 14 SECOND SWELL PERIODS FROM LATE SUNDAY NIGHT TO MONDAY NIGHT. IF FUTURE WAVE MODEL FORECASTS TREND STEADY OR HIGHER WITH THE PEAK OF THIS SWELL TRAIN THEN THE ADVISORY MAY NEED TO BE UPGRADED TO A HIGH SURF WARNING AT A LATER POINT IN TIME. PLEASE STAY TUNED. && .MARINE...AS OF 3:43 AM PST SATURDAY...SOUTHERLY WINDS WILL BECOME STRONG AND GUSTY TODAY AS A COLD FRONT OVER THE EASTERN PACIFIC ADVANCES EAST OVER THE AREA THIS EVENING. GALE FORCE WINDS ARE EXPECTED OVER THE WATERS THIS AFTERNOON AND TONIGHT. COLD UNSTABLE AIR WILL SETTLE OVER THE AREA BRINGING A SLIGHT CHANCE OF THUNDERSTORMS ON SUNDAY. ANOTHER VIGOROUS FRONTAL SYSTEM WILL ADVANCE OVER THE AREA SUNDAY NIGHT AND EARLY MONDAY MORNING. A LARGE WESTERLY SWELL WILL ARRIVE TONIGHT AND PERSIST THROUGH EARLY TUESDAY MORNING. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...WIND ADVISORY...SF BAY AREA FROM NOON TO 11 PM SAT WIND ADVISORY...MRY BAY AREA FROM 1 PM SAT TO 1 AM SUNDAY SCA...MRY BAY FROM 10 AM SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 10 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 10 AM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 10 AM GLW...MRY BAY FROM 4 PM GLW...PIGEON PT TO PT PINOS 0-10 NM FROM 4 PM GLW...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 4 PM GLW...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 4 PM SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 10 AM SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 10 AM SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 10 AM GLW...PT ARENA TO PT REYES 0-10 NM FROM 10 AM GLW...PT REYES TO PIGEON PT 0-10 NM FROM 10 AM GLW...PT ARENA TO PIGEON PT 10-60 NM FROM 10 AM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...SF BAY UNTIL NOON GLW...SF BAY FROM NOON && $$ PUBLIC FORECAST: R_WALBRUN AVIATION/MARINE: CANEPA VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
404 AM PST SAT MAR 5 2016 ...HEAVY RAIN LATER THIS AFTERNOON AND EVENING... ...MODERATE RAIN EVENT SUNDAY NIGHT WITH NEXT FRONT... .SYNOPSIS...PERIODS OF RAIN...MAINLY LIGHT THIS MORNING. RAIN WILL THEN INCREASE AND BECOME MODERATE TO HEAVY AFTER 2 PM AS A STRONG COLD FRONT APPROACHES THE BAY AREA. PERIODS OF HEAVY RAIN THIS EVENING WITH GUSTY SOUTHERLY WINDS. WIND AND RAIN WILL RAPIDLY WIND DOWN BEFORE MIDNIGHT. SHOWERS AND ISOLATED THUNDERSTORMS SUNDAY IN POST FRONTAL ENVIRONMENT. NEXT FRONT ARRIVES SUNDAY NIGHT WITH ANOTHER ROUND OF MODERATE RAINS. SHOWERS LINGER MONDAY THEN DRY THROUGH MIDWEEK. CHANCE OF NORTH BAY RAIN BY WEDNESDAY THEN ALL OF THE BAY AREA AND CENTRAL COAST BY THURSDAY AND FRIDAY. && .DISCUSSION...AS OF 4:04 AM PST SATURDAY...ISSUED A PNS AT 3 AM WITH LATEST 24 HOUR RAINFALL TOTALS. RADAR SHOWS OVERNIGHT STEADY RAINFALL MOVING EASTWARD BUT MORE RETURNS STARTING TO DEVELOP WELL OFFSHORE. WERE STILL IN THE WARM ADVECTION ENVIRONMENT WITH MAINLY LIGHT AND PERIODIC RAINFALL THROUGH LUNCH TIME TODAY. IR SATELLITE OVER THE LAST 6 HOURS OR SO IS SHOWING A BAROCLINIC LEAF CLOUD BLOWING UP OUT NEAR 130W/36N...EVIDENCE OF STRONG INCOMING JET STREAK AND STRENGTHENING SURFACE COLD FRONTAL BOUNDARY. THIS IS THE FEATURE THE MODELS HAVE BEEN HONING IN ON NOW FOR NEARLY THE LAST WEEK. FEATURE WILL QUICKLY APPROACH THE COAST TODAY AND EXPECT MODERATE RAINS TO START IN EARNEST AROUND 2 PM OR SO OVER MUCH OF THE GREATER BAY AREA. LOCAL HILLS SUCH AS BIG SUR AND SANTA CRUZ MOUNTAINS WILL SEE PERIODS OF RAIN THROUGH MOST OF THE DAY. ANYWAY THE HIGHLY ANTICIPATED FRONTAL PASSAGE SHOULD BE OBVIOUS FROM ROUGHLY 3 PM TO 8 PM LOCAL TIME WHEN VERY STRONG WINDS AND HEAVY RAIN OCCUR OVER A SEVERAL HOUR WINDOW OF TIME. DO EXPECT SOME PREFRONTAL SOUTHERLY WIND GUSTS TO SHOW UP AS EARLY AS LUNCH TIME AND CURRENT TIMING OF WIND ADVISORY TO START THEN STILL LOOKS GOOD. SANTA CRUZ MOUNTAINS OFTEN SEE WIND DAMAGE AND LINES DOWN IN THESE TYPE OF PATTERNS AS SYNOPTIC FLOW AND STRONG SOUTHEAST WINDS FLOWING OUT OF SALINAS VALLEY FOCUS UP THERE. ANYWAY THE HRRR AND RAP SHORT TERM MESOSCALE MODELS ARE IN AGREEMENT THAT THE HEAVIEST RAINS FALL FROM ROUGHLY 4 TO 8 PM THIS EVENING (EARLIEST IN THE NORTH BAY AND LATEST IN MONTEREY BAY REGION). STORM TOTALS FROM NOW THROUGH ABOUT 10 PM TONIGHT SHOULD BRING 1-2 INCHES TO THE LOWER ELEVATIONS WITH 2-5 INCHES FOR THE NORTH BAY/SANTA CRUZ AND SANTA LUCIA HILLS. (USUAL DRY SPOTS IN THE SALINAS AND EAST BAY VALLEYS WILL BE UNDER AN INCH). THIS STORM WILL CAUSE ISSUES TONIGHT THROUGHOUT THE BAY AREA WITH TRAFFIC...LOCALIZED FLOODING DUE TO THE HEAVY RAIN RATES OVER A SHORT WINDOW OF TIME AND ASSOCIATED WIND DAMAGE ISSUES. A DISTINCT LULL IN THE ACTION WILL OCCUR AFTER MIDNIGHT BEHIND THE FRONT WITH ONLY SOME LINGERING SHOWERS AND MUCH LIGHTER SW WINDS. SHOWER AND POST FRONTAL T-STORMS POSSIBLE ON SUNDAY BUT PARTLY CLOUDY SKIES WILL PREVAIL FOR MANY AREAS SOUTH OF SAN FRANCISCO ON SUNDAY. NEXT SYSTEM APPROACHING WILL BRING GENTLE WARM ADVECTION RAINS TO THE NORTH BAY BY SUNDAY AFTERNOON. THEN ON SUNDAY NIGHT POTENT SHORTWAVE WITH MUCH COLDER AIR ALOFT WILL PASS FROM NW TO SE ACROSS THE DISTRICT. ANOTHER ROUND OF SOME HEAVY RAIN SHOWERS WITH POSSIBLE T-STORMS WILL OCCUR. RAIN TOTALS WILL BE LESS WITH THIS SYSTEM BUT SOME LOCALIZED HEAVY RAINFALL SHOULD BE EXPECTED. LOOKS LIKE THE BULK OF THE HEAVY RAIN IS DONE BY 12Z MONDAY WITH ONLY SOME LINGERING RAINS SHOWERS BY 15Z MONDAY FOR THE MORNING COMMUTE. HOWEVER EVEN A WET START TO THE COMMUTE IS OFTEN ENOUGH TO THROW THINGS INTO DISARRAY TO START OUT THE WORK WEEK. SIMILAR TO SUNDAY...SHOWERS CHANCES WILL LINGER MONDAY BUT BE ON THE DECREASE THROUGH THE DAY. LOOKS DRY MONDAY NIGHT AND TUESDAY. LATEST ECMWF HAS TRENDED WETTER BY WEDS FOR THE NORTH BAY WITH SOME WARM FRONTAL LIGHT RAIN CHANCES. MORE ORGANIZED COLD FRONT THEN ARRIVES LATER THURSDAY INTO FRIDAY. WILL HONE IN ON THOSE DETAILS AFTER WE GET THROUGH THE WEEKEND SYSTEMS BUT THE STORMS LATER NEXT WEEK LOOK MODERATE IN STRENGTH/INTENSITY. && .AVIATION...AS OF 10:30 PM PST FRIDAY...RADAR INDICATES SHOWERS MOVING OVER THE AREA FROM THE SOUTHWEST. THIS WILL KEEP PERIODS OF LIGHT RAIN GOING THROUGH SATURDAY MORNING WHEN THINGS WILL RAMP UP IN TERMS OF WINDS AND RAIN. CIGS WILL BE BOUNCING UP AND DOWN BUT WILL REMAIN PREDOMINANTLY IN THE MVFR RANGE. SOUTH TO SOUTHEAST WINDS INCREASE AFTER 16Z WITH SURFACE WINDS GUSTING TO 25 KT AND INCREASE EVEN MORE TO 30-35 KT AFTER 21Z. WIND SHEAR MAY BE A FACTOR SATURDAY AFTERNOON AS 925 MB WINDS ARE SOUTHWEST 50 KT. VICINITY OF KSFO...MVFR CIGS. BASES MAINLY 2500 FEET LOWERING TO 1000-1500 FEET AFTER 16Z. RAIN SHOWERS TONIGHT WILL BECOME STEADY MODERATE RAIN SATURDAY MORNING. SOUTHERLY WINDS AROUND 15 KT INCREASING TO 20-25 KT WITH GUSTS TO 30 KT AFTER 16Z. WINDS FURTHER INCREASING AS FRONT MOVES IN AND WILL LIKELY REACH AIRPORT WEATHER WARNING CRITERIA. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS WITH RAIN SHOWERS. STEADIER RAIN RETURNING BY SATURDAY AFTERNOON WITH INCREASING SOUTHERLY WINDS. && .BEACHES...AS OF 10:30 PM PST FRIDAY...LARGE SWELLS WILL ARRIVE ALONG THE COAST BY MONDAY. SWELL HEIGHTS MAY REACH 15 TO 20 FEET WITH SWELL PERIOD OF 14 SECONDS. WEST FACING BEACHES WILL FEEL THE BRUNT OF THIS SWELL TRAIN... WITH STRONG RIP CURRENTS... LARGE SHORE BREAK... AND SNEAKER WAVES POSSIBLE. A COMBINATION OF HIGH SURF... MODERATE TO HEAVY RAIN... AND HIGH TIDE MAY ALSO LEAD TO COASTAL FLOODING OVER THE UPCOMING DAYS. REMEMBER... NEVER UNDERESTIMATE THE OVERWHELMING POWER OF THE OCEAN... SEVERAL INDIVIDUALS HAVE BEEN SWEPT OUT TO SEA THIS SEASON. && .MARINE...AS OF 03:26 AM PST SATURDAY... A POWERFUL STORM WILL BRING RAIN AND STRONG WINDS TO THE AREA SATURDAY. GALE FORCE WINDS ARE EXPECTED OVER THE WATERS SATURDAY AFTERNOON AND NIGHT. WINDS WILL DECREASE EARLY SUNDAY AFTER THE STORM MOVES THROUGH BUT COLD UNSTABLE AIRMASS WILL SETTLE OVER THE AREA BRINGING A SLIGHT CHANCE OF THUNDERSTORMS ON SUNDAY. A LARGE MODERATE TO LONG PERIOD WEST SWELL WILL BEGIN TO ARRIVE AND PERSIST THROUGH EARLY NEXT WEEK. THE LARGEST SWELL ARRIVES MONDAY. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...WIND ADVISORY...SF BAY AREA FROM NOON TO 11 PM SAT WIND ADVISORY...MRY BAY AREA FROM 1 PM SAT TO 1 AM SUNDAY SCA...MRY BAY FROM 10 AM SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 10 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 10 AM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 10 AM GLW...MRY BAY FROM 4 PM GLW...PIGEON PT TO PT PINOS 0-10 NM FROM 4 PM GLW...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 4 PM GLW...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 4 PM SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 10 AM SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 10 AM SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 10 AM GLW...PT ARENA TO PT REYES 0-10 NM FROM 10 AM GLW...PT REYES TO PIGEON PT 0-10 NM FROM 10 AM GLW...PT ARENA TO PIGEON PT 10-60 NM FROM 10 AM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...SF BAY UNTIL NOON GLW...SF BAY FROM NOON && $$ PUBLIC FORECAST: R_WALBRUN AVIATION: CANEPA MARINE: CANEPA VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
603 AM CST SAT MAR 5 2016 .SHORT TERM...(Today) ISSUED AT 241 AM CST SAT MAR 5 2016 Patchy fog will affect central Illinois ahead of an advancing cold front early this morning. The fog will clear by mid-morning as cold front departs into Indiana by 11 am. Little to no precipitation is expected with the frontal passage in central Illinois, except for possibly a few sprinkles in areas northeast of Champaign to Danville. Winds will shift from southwest to northwest behind the front, and become breezy with gusts to 25 mph at times later this morning and this afternoon. The latest HRRR and RAP guidance are pointing towards enough residual low level moisture behind the front for mostly cloudy skies to linger through at least mid-afternoon. Breaks will eventually develop in the cloud layer due to turbulent mixing of dry mid-level air toward the surface. Areas southwest of Springfield to Mattoon will have the best chances of seeing sunshine earlier, but even northeast areas should see sunshine break through later this afternoon. Even limited late afternoon sunshine should help high temperatures reach the mid 40s north of I-74, with lower 50s for areas from Jacksonville to Effingham to Lawrenceville. .LONG TERM...(Tonight through Friday) ISSUED AT 241 AM CST SAT MAR 5 2016 Mild and wet period shaping up for much of the upcoming week, as upper flow finally trends more toward the southwest. Main issue will be with the rains, as a frontal boundary will be draped over the state part of the time, and will limit some of the rainfall north of it around midweek. High pressure will quickly pass through the Midwest tonight, and southerly winds will be in place by Sunday morning and become a bit gusty. This will bring temperatures well into the 50s, with some 60 degree readings possible over the southwest CWA. Some WAA-type precip expected to develop by afternoon west of the Illinois border, but forecast soundings in our area quite parched below 700 mb until evening, and thus will keep the daytime hours dry albeit with increasing clouds. Have limited mentionable PoP`s Sunday night to west of I-55, with most of the energy tracking into northwest Illinois. On Monday, southerly winds expected to gust from 25-30 mph, pushing temperatures well into the 60s. During this time, an upper trough will be digging southward along the California coast, closing off a low over the Baja. Nice moisture surge coming northward from the Gulf of Mexico will combine with a wave/front in the northern stream to gradually increase rain chances from west to east across the state. Reasonable agreement among the models through about Tuesday evening with the cold front being just to our northwest. Waves of low pressure will surge northeast along the front bringing periods of heavier rain, but how far south the front makes it first will be key. The ECMWF is slowest in exiting the rain (not until Thursday evening over the southeast CWA), while the GFS and Canadian show periodic surges of rain until Thursday morning. Went with categorical PoP`s (80%) for most areas east of I-55 Tuesday night through Wednesday night. WPC progs and blended model guidance suggesting potential for 3-4 inches of rain through the week in this area, subject to the oscillations of the front. Hydrologic Outlook product is being used to address this heavy rain concern for the time being. The upper low will only slowly drift through northern Mexico, cut off from the northern flow through much of the week. Late in the period, the GFS and ECMWF show this low finally ejecting northeast, although the GFS is much faster in bringing the frontal boundary back north. With the front position still a significant question, PoP`s generally remain in place over most of the forecast area into Friday. Temperatures north of the front will cool a bit mid week, but still be mid-upper 50s for highs. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) ISSUED AT 600 AM CST SAT MAR 5 2016 A cold front, currently passing on a line from Galesburg to Quincy, will continue to track east across our area this morning. Forecast soundings and last few runs of the HRRR model correctly depicted the IFR/LIFR ceilings in over our eastern terminals of CMI, BMI, and DEC. PIA also dropped down to VLIFR vis and IFR cig. Conditions will improve to VFR at all the terminal sites as the cold front passes between 13z and 16z. Satellite images show a region of high MVFR and VFR clouds rotating into NW IL. They are poised to affect all of our terminal sites later this morning and early this afternoon, with less coverage for the southern TAF sites of SPI and DEC. Turbulent mixing of dry mid level air should help to create breaks in cloud cover as the afternoon progresses. The winds are the other issue today, with southwest winds becoming light as the cold front passes, then increasing out of the northwest shortly after FROPA. Sustained winds will become 12-16kt with gusts to 23kt at times late this morning and early this afternoon. Pressure rises will weaken later this afternoon, with gusts diminishing by sunset. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Shimon LONG TERM...Geelhart AVIATION...Shimon
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
955 AM EST SAT MAR 5 2016 .UPDATE... ISSUED AT 955 AM EST SAT MAR 5 2016 14Z SFC ANALYSIS SHOWS LOW PRESSURE DIVING SOUTHEAST THROUGH THE GREAT LAKES WITH A WEAK COLD FRONT PASSING THE MID MISSISSIPPI VALLEY. HERE TO THE EAST...A MID LEVEL DISTURBANCE IS DEPARTING THE CENTRAL APPALACHIANS. THIS IS RESULTING IN SOME LIGHT PCPN DROPPING THROUGH EAST KENTUCKY THIS MORNING. IN ADDITION TO THE SPRINKLES AND LIGHT RAIN...AREAS OF FOG...LOCALLY DENSE...PLAGUED THE HIGHER ELEVATIONS THROUGH EAST KENTUCKY EARLY THIS MORNING. THE FOG IS STARTING TO DISSIPATE WITH IMPROVING VISIBILITY AND LIFTING CEILINGS. HOWEVER...THE LOW CLOUDS AND PCPN ARE RETARDING A TEMPERATURE RISE SO FAR THIS MORNING WITH MOST PLACES STILL IN THE LOW 30S. THE APPROACH OF THE WEAKENING LOW AND ITS FRONT SHOULD MIX OUT THE LOWER CLOUDS BY MIDDAY WITH WARMING TEMPERATURES THE RESULT...THOUGH ANOTHER ROUND MORE SUBSTANTIVE SHOWERS WILL LIKELY DEVELOP AND CROSS EAST KENTUCKY THIS AFTERNOON. HAVE ADJUSTED THE FORECAST TO SLOW THE TEMP RISE THIS MORNING AND TO FINE TUNE THE POPS/WX THROUGH THE AFTERNOON PER THE LATEST HRRR AND NAM12. DID ALSO TWEAK THE DEWPOINTS...CURRENTLY REPORTING SIMILAR VALUES TO DRY TEMPS AT MOST SITES...PER THE LATEST OBS AND TRENDS. LIGHT WINDS EARLY THIS MORNING WILL SHIFT TO THE SOUTHWEST AND PICK UP TO NEAR 10 MPH THIS AFTERNOON ALSO HELPING TEMPS TO REBOUND INTO THE 40S. THE GRID UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS...WITH A FRESHENED SET OF ZONES AND HWO ALSO ISSUED. UPDATE ISSUED AT 656 AM EST SAT MAR 5 2016 CURRENT RADAR IS SHOWING A LINE OF PRECIPITATION MOVING ACROSS THE NORTHERN PORTION OF THE CWA. ACCORDING TO THE LATEST OBSERVATIONS...PRECIP IS LIKELY STILL NOT HITTING THE GROUND...WITH ONLY ONE BRIEF OBSERVATION OF LIGHT SNOW IN THE CINCINNATI AREA UNDER A HIGHER RETURN OVER THE LAST HOUR. IT IS POSSIBLE THAT SOME FLURRIES ARE OCCURRING OUT OF THIS GIVEN TEMPERATURES AT OR NEAR THE FREEZING MARK...BUT NOTHING IS EXPECTED TO ACCUMULATE. OVER THE NEXT HOUR...EXPECT RETURNS TO INTENSIFY AND PRECIP TO BEGIN HITTING THE GROUND...BUT NOT BEFORE TEMPERATURES BEGIN A WARMING TREND ABOVE FREEZING AND PRECIP CHANGES TO MAINLY RAIN. MEANWHILE...STILL SEEING QUITE A BIT OF FOG ACROSS THE REMAINDER OF THE CWA...THOUGH THERE HAS BEEN SIGNS OF VIS IMPROVEMENT AT MANY SITES. ACCORDING TO THE OBS IT SEEMS AS THOUGH MUCH OF THE FOG IS ELEVATED AT THIS POINT...MAINLY AFFECTING THE RIDGE TOPS. SEVERAL OBSERVATIONS ACROSS EASTERN KY ARE ALSO STILL REPORTING TEMPS AT OR JUST BELOW 32 DEGREES...SO WILL CONTINUE MENTION OF FREEZING FOG AS WELL IN THE GRIDS FOR THE NEXT HOUR. CURRENT SPS HIGHLIGHTING PATCHY DENSE FOG AND POSSIBLE SLICK CONDITIONS FROM FREEZING FOG/SLICK ROADWAYS WILL BE ALLOWED TO EXPIRE AT 7AM...AS FOG SHOULD CONTINUE LIFTING/MIXING OUT AND TEMPERATURES WILL BE WARMING AFTER THIS POINT. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 349 AM EST SAT MAR 5 2016 LINGERING LLVL MOISTURE AND STRONG SUBSIDENCE IN PLACE THROUGH THE FIRST PART OF THE NIGHT HAS LED TO FOG DEVELOPMENT ACROSS MUCH OF THE CWA. GIVEN TEMPERATURES AT OR BELOW FREEZING IN MANY LOCATIONS AS WELL...THIS ALSO CREATED A SET UP FOR POTENTIAL FREEZING FOG. AN AREA OF LOW PRESSURE IS CURRENTLY MOVING EASTWARD INTO THE UPPER GREAT LAKES REGION AS OF 8Z THIS MORNING. THIS IS PUSHING THE SURFACE HIGH IN PLACE EAST OF THE REGION...AND ALLOWING MID AND UPPER LEVEL MOISTURE TO BEGIN FILTERING INTO THE REGION. DESPITE THIS...SOUNDINGS STILL SUPPORT A DECENT LLVL INVERSION WHICH WILL LIKELY KEEP THE FOG AND FREEZING FOG IN PLACE THROUGHOUT THE REST OF THE NIGHT. BY 12Z THIS MORNING...THE LOW IS EXPECTED TO BEGIN QUICKLY DROPPING SOUTHEASTWARD...CLIPPING THE FAR NE PORTION OF THE STATE BY LATE THIS AFTERNOON...BEFORE EXITING EASTWARD OVERNIGHT. THIS QUICK DROP SOUTHWARD WILL LIKELY CLEAR OUT ANY REMAINING FOG ACROSS THE REGION. OVERALL THIS SYSTEM IS BOTH FAST MOVING AND RELATIVELY WEAK. HOWEVER...THERE WILL BE ENOUGH MOISTURE SUPPORT FROM LLVL SRLY WINDS TO PROMOTE SOME SCATTERED BUT LIGHT PRECIP POTENTIAL ACROSS THE CWA. LATEST HI RES MODELS ARE SHOWING PRECIP DEVELOPING ALONG OUR FAR NW CWA AROUND OR JUST AFTER 12Z THIS MORNING...WITH SCATTERED ACTIVITY OVERSPREADING FROM NW TO SE THROUGHOUT THE DAY...THEN EXITING TO OUR EAST OVERNIGHT. BEST QPF AND POPS WILL BE ACROSS THE NORTHERN AND FAR EASTERN CWA...CLOSEST TO THE CENTER OF THE LOW. WILL CONTINUE TO MONITOR THE TEMPERATURES AS THE PRECIP BEGINS TO NEAR THE REGION THIS MORNING...AS IT IS LIKELY THAT BELOW FREEZING TEMPS COULD LEAD TO SOME SNOW AT ONSET...BEFORE CHANGING OVER TO ALL RAIN AS CONDITIONS WARM TO ABOVE FREEZING AFTER 12Z. OVERALL...NOT LOOKING AT ANY ACCUMULATIONS IF SNOW DOES OCCUR...AND SHOULD BE A PRETTY QUICK TURNOVER. OTHERWISE...TEMPERATURES WILL REMAIN ABOVE FREEZING THROUGHOUT THE DURATION OF THE EVENT...SO REST OF PRECIP SHOULD FALL AS ALL RAIN. AMPLIFIED RIDGING WILL SHIFT EASTWARD ACROSS KY BEHIND THE EXITING SHORTWAVE AND LOW PRESSURE SYSTEM TONIGHT AND THROUGH THE DAY SUNDAY. WITH LINGERING MOISTURE IN PLACE ONCE MORE TONIGHT...AND STRONG SUBSIDENCE TAKING HOLD...EXPECT SOME FOG DEVELOPMENT TO RESULT ONCE MORE. IT IS POSSIBLE THAT THERE COULD BE SOME WIDESPREAD AND/OR DENSE FOG IN LOCATIONS THAT RECEIVE RAINFALL TODAY...AND NEAR SOME BODIES OF WATER. HOWEVER...GIVEN THE LOW CONFIDENCE ON WHERE BEST IMPACTS FROM RAIN WILL BE...JUST STUCK WITH PATCHY FOG MENTION ACROSS ENTIRE CWA AT THIS TIME. SURFACE HIGH PRESSURE WILL ACCOMPANY THIS AMPLIFIED RIDGING...CROSSING DIRECTLY OVER KY DURING THE DAY SUNDAY. AS A RESULT...EXPECT LIGHT WINDS...CLEARING SKIES...AND TEMPERATURES WARMING INTO THE MID 50S. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 359 AM EST SAT MAR 5 2016 WARMING TEMPERATURES AND A DRY START TO THE WEEK REMAIN IN THE OFFING COURTESY OF BUILDING HEIGHTS/THICKNESSES ASSOCIATED WITH BROAD EASTERN CONUS RIDGING. FURTHER WARMING WILL ENSUE AS FLOW BACKS SOUTHWEST ALOFT IN RESPONSE TO AN UPPER LEVEL LOW DIGGING THROUGH BAJA CALIFORNIA INTO CHIHUAHUA MEXICO. WELL ABOVE NORMAL TEMPERATURES WILL BE THE RULE WITH HIGHS LOOKING TO TOP OUT BETWEEN THE MID 60S TO MID 70S AS LOWS FROM TUESDAY MORNING INTO THE WEEKEND ONLY FALL INTO THE MID 40S TO MID 50S. GIVEN THE DEEP SOUTHERN TRACK OF THE AFOREMENTIONED SYSTEM...SURFACE LOW PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS WILL BE SLOW TO EJECT EASTWARD IN AN AMPLIFIED PATTERN AS SURFACE RIDGING ESTABLISHES A LENGTHY RESIDENCE TIME ACROSS THE MID TO SOUTHERN ATLANTIC COAST. THIS WILL LIKELY KEEP ANY EARLIER WEEK RAINFALL...RESULTING FROM AN INITIAL SHORTWAVE IMPULSE...WELL WEST OF INTERSTATE 71. PROSPECTS FOR RAINFALL ACROSS CENTRAL INTO EASTERN KENTUCKY LOOK TO BECOME MUCH BETTER FOR MID-LATE WEEK AS UPPER ENERGY APPROACHES IN TANDEM WITH A SURFACE LOW AND PLENTY OF DEEP LAYER MOISTURE. APPRECIABLE THUNDER CHANCES CONTINUE TO LOOK POSSIBLE AS LONG AS INSTABILITY CAN MATERIALIZE AMID PLENTY OF MID- HIGH CLOUD COVER. A NORTHERN STREAM TROUGH MAY ALSO ATTEMPT TO DIVE FAR ENOUGH SOUTH TO AID IN PROVIDING ADDITIONAL LIFT FOR SHOWER/THUNDERSTORM POTENTIAL. DEPENDING ON THE TRACK/EVOLUTION OF THE UPPER LOW...RAINFALL COULD VERY WELL LAST INTO THE WEEKEND. WILL HAVE TO MONITOR HEAVY RAIN/FLOODING THREAT GOING FORWARD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 713 AM EST SAT MAR 5 2016 A LOW PRESSURE SYSTEM IS CURRENTLY LOCATED OVER THE UPPER GREAT LAKES AND IS EXPECTED TO DROP SOUTHWARD AND ACROSS EASTERN KY BY THIS AFTERNOON. THIS WILL RESULT IN SCATTERED LIGHT RAIN SHOWERS ACROSS MUCH OF THE AREA THROUGHOUT THE DAY...WITH BEST CHANCES AT KSYM AND KSJS...CLOSER TO THE CENTER OF THE LOW PRESSURE SYSTEM. KEPT WITH VCSH MENTION THROUGHOUT THE DAY /STARTING WITH KSYM AT 13Z/ DUE TO THE SCATTERED NATURE OF THE SHOWERS AND LOW CONFIDENCE ON WHEN A SPECIFIC TAF SITE WILL BE IMPACTED AND TO WHAT DEGREE. THE LOW PRESSURE SYSTEM AND ASSOCIATED RAIN WILL QUICKLY EXIT EASTWARD OVERNIGHT. AS HIGH PRESSURE FILLS IN...ANOTHER SUBSIDENCE/LLVL MOISTURE WILL SET UP...LIKELY LEADING TO MORE FOG DEVELOPMENT ACROSS THE REGION. OVERALL...WINDS SHOULD REMAIN LIGHT THROUGHOUT THE TAF PERIOD...PREDOMINATELY FROM THE SW BEFORE BECOMING MORE WRLY BEHIND THE PASSING COLD FRONT AFTER 0Z THIS EVENING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JMW LONG TERM...GUSEMAN AVIATION...JMW
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
959 AM EST SAT MAR 5 2016 .UPDATE... HAVE ALL BUT REMOVED FREEZING DRIZZLE MENTION...AS 700 MB COLD OF -14 TO -15 C SLOWLY TRACKS THROUGH SOUTHEAST MICHIGAN DURING THE REMINDER OF THE DAY SUPPORTING ALL SNOW...WITH RADAR TRENDS SUPPORTING MORE CONVECTIVE SNOW BANDS/HIGHER RATES...AND HAVE GONE AHEAD AND RAISED ACCUMULATIONS TO ACCOUNT FOR 2 INCH TOTALS ACROSS WASHTENAW/LENAWEE COUNTIES...AND WITH THE SLOW MOVING CONVERGENCE ZONE AND PROLONGED PERIOD THROUGH THE AFTERNOON HOURS...3 INCHES CAN`T BE RULED OUT. && .PREV DISCUSSION...ISSUED 826 AM EST SAT MAR 5 2016 UPDATE... QUICK UPDATE TO RAISE POPS AND CARRY MORE SNOW (VS FREEZING DRIZZLE BASED ON LATEST RADAR TRENDS)...AS MID LEVEL CIRCULATION ROTATING THROUGH CENTRAL LAKE MICHIGAN/SOUTHWEST LOWER MICHIGAN PROVIDES SUFFICIENT FORCING ON THE NORTHEAST FLANK TO SUPPORT SNOW SHOWERS...AS IR SHOWS CLOUD TOP COOLING AND SUFFICIENT ICE NUCLEI. THE WEAK LOW LEVEL CIRCULATION WILL SLOWLY TRACK SOUTHEAST...EXPECTED TO MOVE THROUGH LENAWEE COUNTY AND INTO NORTHWEST OHIO LATE THIS AFTERNOON. SHOULD BE ABLE TO GRIND OUT AT LEAST AN INCH OF SNOW ACCUMULATION ALONG AND WEST OF U.S. 23 UP TO ABOUT M-59. WILL HAVE TO WATCH OUT FOR LOCALIZED HIGHER AMOUNTS IF CONVECTIVE ELEMENTS ARE MORE VIGOROUS. && .AVIATION...ISSUED 505 AM EST SAT MAR 5 2016 INITIAL ROUND OF SNOW WILL EXIT EAST OF THE TERMINAL BY 12Z. SURFACE OBSERVATIONS AND RADAR IMAGERY THEN SUPPORT IFR CEILINGS...FOG AND LIGHT FREEZING DRIZZLE SPREADING INTO THE AREA FROM OVER WISCONSIN AS LOW PRESSURE OVER THE WESTERN GREAT LAKES TRACKS TOWARDS THE OHIO VALLEY. THE DRIZZLE AND FOG WILL OCCUR AS DRIER AIR IN THE MID-LEVELS ARRIVES...WHICH WILL ALSO MAKE THE THREAT FOR SNOW DURING THIS TIMEFRAME VERY LOW. ADDITIONAL MOISTURE WILL WRAP IN AS LOW PRESSURE TRACKS SOUTH OF THE AREA THIS AFTERNOON...ALLOWING A SECOND ROUND OF LIGHT SNOW TO AFFECT THE TERMINALS MAINLY FROM PTK SOUTH. ADDITIONAL ACCUMULATIONS SHOULD BE UNDER 0.5 INCHES. CEILINGS SHOULD REMAIN IFR HOWEVER. A RIDGE OF HIGH PRESSURE WILL SLIDE IN OVERHEAD TONIGHT...ENDING THE THREAT FOR PRECIPITATION. CALM CONDITIONS WILL THEN PROMOTE THE DEVELOPMENT OF FOG AND STRATUS OVERNIGHT. WILL FAVOR FOG FROM FNT SOUTH...CLOSER TO THE RIDGE AXIS WHERE WINDS SHOULD BE CALM...AND LEAN MORE TOWARDS STRATUS ALONG THE NORTHERN PERIPHERY OF THE RIDGE AXIS AT MBS OVERNIGHT. FOR DTW...IFR CEILINGS...BR...AND -FZDZ OBSERVED UPSTREAM OVER WISCONSIN AND FAR WESTERN MICHIGAN SHOULD MOVE WEST TOWARDS DTW EARLY IN THE TAF PERIOD. THIS SHOULD LAST INTO AFTERNOON UNTIL ADDITIONAL MOISTURE WORKS INTO THE AREA...BRINGING ANOTHER ROUND OF SNOW TO THE AREA. ACCUMULATIONS UP TO 0.5 INCHES ARE EXPECTED. IFR CONDITIONS SHOULD LIFT THIS EVENING...WITH MVFR FOG FILLING IN OVERNIGHT AS HIGH PRESSURE AND CALM CONDITIONS SPREAD INTO LOWER MICHIGAN. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CEILINGS AOB 5000 FEET TODAY AND THIS EVENING. LOW OVERNIGHT. * MEDIUM FOR FREEZING DRIZZLE AS PRECIPITATION TYPE BETWEEN 12- 17Z. HIGH FOR SNOW AS PRECIPITATION TYPE THIS AFTERNOON. && PREV DISCUSSION...ISSUED 309 AM EST SAT MAR 5 2016 DISCUSSION... LIGHT SNOW OVERSPREAD MUCH OF SE MI OVERNIGHT. SFC OBSERVATIONS AND RADAR SUGGEST SOME LOCALS /PARTICULARLY SOUTH OF THE I-69 CORRIDOR/ HAVE BEEN EXPERIENCING INTERVALS OF FAIRLY GOOD SNOWFALL RATES. THIS SNOW IS OCCURRING WITHIN A REGION OF MID LEVEL ISENTROPIC ASCENT AHEAD OF AN UPPER SHORT WAVE NOW OVER WISCONSIN...AIDED BY A LEAD SHORT WAVE IMPULSE NOW ROTATING INTO SE MI. THE UPSTREAM MID LEVEL TROUGH WILL ROTATE INTO THE OHIO VALLEY BY AFTERNOON...WITH THE ASSOCIATED SFC LOW /OVER CNTRL WISCONSIN AS OF 07Z/ TRACKING INTO NRN INDIANA BY EARLY AFTERNOON. THE REGIONAL WATER VAPOR LOOP SHOWS THE AXIS OF DEEP LAYER MOISTURE ALREADY OVER SE MI...WITH MID LEVEL DRY AIR FAST MOVING INTO SW LOWER MI. THIS LOSS OF MID LEVEL MOISTURE IS LEADING TO AN ABRUPT END TO THE LIGHT SNOW OVER SW LOWER ATTM. MODEL RH PROGS AND SOUNDINGS /WITH SUPPORT FROM THE WATER VAPOR LOOP/ INDICATE THE MID LEVEL DRY AIR WILL OVERSPREAD SE MI BY 12Z. THE RESULTING BRIEF DURATION OF THE SNOW EARLY THIS MORNING WILL KEEP ACCUMS TO AN INCH OR LESS /WITH THE HIGHEST AMOUNTS SOUTH OF I-69/. DESPITE THE LOSS OF MID LEVEL MOISTURE...THERE WILL BE AN ADDITIONAL INFLUX OF LOW LEVEL MOISTURE /SUB 850MB/ DRIVEN INTO SE MI DURING THE MORNING. THIS WILL PROVIDE A GOOD SET UP FOR SOME FREEZING DRIZZLE. THIS AND THE AMOUNT OF FZDZ REPORTS ACROSS WISCONSIN SUPPORT ADDING AREAS OF FZDZ TO THE MORNING FORECAST. BY THE TIME THAT CONDITIONS BECOME OPTIMAL FOR FZDZ...SFC TEMPS SHOULD BE WARMING INTO THE LOWER 30S AND LIKELY ABOVE FREEZING BY NOON. THIS AND THE POTENTIAL SHORT DURATION OF ANY DRIZZLE WILL SUPPORT HOLDING OFF ON ANY TYPE OF WINTER WX ADVISORIES FOR THE TIME BEING. DEEP LAYER MOISTURE WILL ROTATE BACK INTO SE MI THIS AFTERNOON. WITH SOME STEEP MID LEVEL LAPSE RATES AND DIURNAL INSTABILITY...SNOW SHOWER ACTIVITY IS POSSIBLE. THE NAM AND HRRR SUGGEST SOME FGEN DEVELOPMENT ALONG THE MID TROPOSPHERIC FRONT...GENERALLY SOUTH OF THE M 59 CORRIDOR EARLY IN THE AFTERNOON. THIS WILL NOT ONLY WARRANT HIGHER POPS IN THESE LOCALS BUT ALSO SUGGEST SOME ADDITIONAL LIGHT AFTERNOON SNOW ACCUMS /POSSIBLY A HALF INCH/. SFC HIGH PRESSURE WILL EXPAND ACROSS SE TONIGHT AMIDST RISING MID LEVEL HEIGHTS IN THE WAKE OF THE DEPARTING UPPER TROUGH. LOW LEVEL ANTICYCLONIC FLOW AND DRY AIR ADVECTION SHOULD CLEAR THE LOW CLOUDS OUT LATE IN THE NIGHT...SUPPORTING A BRIEF PERIOD OF DECENT RADIATIONAL COOLING. IF THIS COOLING OCCURS A LITTLE EARLIER...LATER SHIFTS WILL HAVE TO CONSIDER ADDING FOG TO THE FORECAST. LONG WAVE RIDGE AMPLIFICATION ACROSS THE ERN US EARLY NEXT WEEK AND THE ESTABLISHMENT OF STRENGTHENING SOUTHWEST FLOW FROM THE SRN PLAINS INTO THE UPPER MIDWEST AND GREAT LAKES WILL SUPPORT A DRAMATIC WARM UP BEGINNING SUNDAY AND PERSISTING THROUGH AT LEAST TUESDAY. DESPITE THE SNOW COVER...THE STRONG LOW LEVEL WARM AIR ADVECTION WITHIN THE WELL MIXED SW FLOW WILL SUPPORT TEMPS ON THE HIGH END OF GUIDANCE /40S SUNDAY...50S MON...60S TUES/. CONSENSUS AMONG THE MEDIUM RANGE MODEL SUITE INDICATE BETTER RAINFALL CHANCES MID TO LATE WEEK AS MUCH DEEPER MOISTURE GETS ADVECTED INTO THE GREAT LAKES. A GOOD DEAL OF FCST UNCERTAINTY REVOLVES AROUND TIMING A BACK DOOR COLD FRONT THROUGH THE AREA NEXT WEEK. MODEL SOLUTIONS DIVERGE WITH RESPECT TO TIMING AND AMPLITUDE OF AN UPPER WAVE TRACKING ACROSS CANADA WHICH RESULTS IN A LARGE SPREAD IN TIMING THIS BACK DOOR COLD FRONT INTO SE MI. IT LOOKS AS THOUGH THIS FRONT WILL MOVE THROUGH SOMETIME IN THE WED TO THURS TIME FRAME AND WILL HAVE THE POTENTIAL TO BRING MUCH COOLER LAKE MODIFIED BOUNDARY LAYER AIR INTO THE AREA /WITH WARM MOIST SOUTHWEST FLOW ALOFT STILL PROVING PERIODIC CHANCES FOR RAIN SHOWERS/. MARINE... WINDS WILL REMAIN LIGHT TODAY...GENERALLY UNDER 10 KNOTS...AS LOW PRESSURE SLIDES FROM THE WESTERN GREAT LAKES INTO THE OHIO VALLEY TODAY...AND THEN A RIDGE OF HIGH PRESSURE SHIFTS INTO THE AREA TONIGHT. LOW PRESSURE TRACKING ACROSS HUDSON BAY AND ONTARIO SUNDAY INTO SUNDAY NIGHT WILL THEN PROVIDE A TIGHTER SURFACE PRESSURE GRADIENT OVER THE AREA...CAUSING WINDS TO INCREASE. THE STRONGEST WINDS LOOK TO OCCUR OVER THE OPEN WATERS OF LAKE HURON...WITH SPEEDS INTO THE 20 TO 25 KNOT RANGE. GUSTS SHOULD REMAIN BELOW GALE FORCE HOWEVER AS WARMER AIR SURGING INTO THE AREA WILL PROVIDE A HIGH DEGREE OF STABILITY OVER THE COLD LAKE WATERS. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......SF AVIATION.....HLO DISCUSSION...SC MARINE.......HLO YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
826 AM EST SAT MAR 5 2016 .UPDATE... QUICK UPDATE TO RAISE POPS AND CARRY MORE SNOW (VS FREEZING DRIZZLE BASED ON LATEST RADAR TRENDS)...AS MID LEVEL CIRCULATION ROTATING THROUGH CENTRAL LAKE MICHIGAN/SOUTHWEST LOWER MICHIGAN PROVIDES SUFFICIENT FORCING ON THE NORTHEAST FLANK TO SUPPORT SNOW SHOWERS...AS IR SHOWS CLOUD TOP COOLING AND SUFFICIENT ICE NUCLEI. THE WEAK LOW LEVEL CIRCULATION WILL SLOWLY TRACK SOUTHEAST...EXPECTED TO MOVE THROUGH LENAWEE COUNTY AND INTO NORTHWEST OHIO LATE THIS AFTERNOON. SHOULD BE ABLE TO GRIND OUT AT LEAST AN INCH OF SNOW ACCUMULATION ALONG AND WEST OF U.S. 23 UP TO ABOUT M-59. WILL HAVE TO WATCH OUT FOR LOCALIZED HIGHER AMOUNTS IF CONVECTIVE ELEMENTS ARE MORE VIGOROUS. && .AVIATION...ISSUED 505 AM EST SAT MAR 5 2016 INITIAL ROUND OF SNOW WILL EXIT EAST OF THE TERMINAL BY 12Z. SURFACE OBSERVATIONS AND RADAR IMAGERY THEN SUPPORT IFR CEILINGS...FOG AND LIGHT FREEZING DRIZZLE SPREADING INTO THE AREA FROM OVER WISCONSIN AS LOW PRESSURE OVER THE WESTERN GREAT LAKES TRACKS TOWARDS THE OHIO VALLEY. THE DRIZZLE AND FOG WILL OCCUR AS DRIER AIR IN THE MID-LEVELS ARRIVES...WHICH WILL ALSO MAKE THE THREAT FOR SNOW DURING THIS TIMEFRAME VERY LOW. ADDITIONAL MOISTURE WILL WRAP IN AS LOW PRESSURE TRACKS SOUTH OF THE AREA THIS AFTERNOON...ALLOWING A SECOND ROUND OF LIGHT SNOW TO AFFECT THE TERMINALS MAINLY FROM PTK SOUTH. ADDITIONAL ACCUMULATIONS SHOULD BE UNDER 0.5 INCHES. CEILINGS SHOULD REMAIN IFR HOWEVER. A RIDGE OF HIGH PRESSURE WILL SLIDE IN OVERHEAD TONIGHT...ENDING THE THREAT FOR PRECIPITATION. CALM CONDITIONS WILL THEN PROMOTE THE DEVELOPMENT OF FOG AND STRATUS OVERNIGHT. WILL FAVOR FOG FROM FNT SOUTH...CLOSER TO THE RIDGE AXIS WHERE WINDS SHOULD BE CALM...AND LEAN MORE TOWARDS STRATUS ALONG THE NORTHERN PERIPHERY OF THE RIDGE AXIS AT MBS OVERNIGHT. FOR DTW...IFR CEILINGS...BR...AND -FZDZ OBSERVED UPSTREAM OVER WISCONSIN AND FAR WESTERN MICHIGAN SHOULD MOVE WEST TOWARDS DTW EARLY IN THE TAF PERIOD. THIS SHOULD LAST INTO AFTERNOON UNTIL ADDITIONAL MOISTURE WORKS INTO THE AREA...BRINGING ANOTHER ROUND OF SNOW TO THE AREA. ACCUMULATIONS UP TO 0.5 INCHES ARE EXPECTED. IFR CONDITIONS SHOULD LIFT THIS EVENING...WITH MVFR FOG FILLING IN OVERNIGHT AS HIGH PRESSURE AND CALM CONDITIONS SPREAD INTO LOWER MICHIGAN. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CEILINGS AOB 5000 FEET TODAY AND THIS EVENING. LOW OVERNIGHT. * MEDIUM FOR FREEZING DRIZZLE AS PRECIPITATION TYPE BETWEEN 12- 17Z. HIGH FOR SNOW AS PRECIPITATION TYPE THIS AFTERNOON. && .PREV DISCUSSION...ISSUED 309 AM EST SAT MAR 5 2016 DISCUSSION... LIGHT SNOW OVERSPREAD MUCH OF SE MI OVERNIGHT. SFC OBSERVATIONS AND RADAR SUGGEST SOME LOCALS /PARTICULARLY SOUTH OF THE I-69 CORRIDOR/ HAVE BEEN EXPERIENCING INTERVALS OF FAIRLY GOOD SNOWFALL RATES. THIS SNOW IS OCCURRING WITHIN A REGION OF MID LEVEL ISENTROPIC ASCENT AHEAD OF AN UPPER SHORT WAVE NOW OVER WISCONSIN...AIDED BY A LEAD SHORT WAVE IMPULSE NOW ROTATING INTO SE MI. THE UPSTREAM MID LEVEL TROUGH WILL ROTATE INTO THE OHIO VALLEY BY AFTERNOON...WITH THE ASSOCIATED SFC LOW /OVER CNTRL WISCONSIN AS OF 07Z/ TRACKING INTO NRN INDIANA BY EARLY AFTERNOON. THE REGIONAL WATER VAPOR LOOP SHOWS THE AXIS OF DEEP LAYER MOISTURE ALREADY OVER SE MI...WITH MID LEVEL DRY AIR FAST MOVING INTO SW LOWER MI. THIS LOSS OF MID LEVEL MOISTURE IS LEADING TO AN ABRUPT END TO THE LIGHT SNOW OVER SW LOWER ATTM. MODEL RH PROGS AND SOUNDINGS /WITH SUPPORT FROM THE WATER VAPOR LOOP/ INDICATE THE MID LEVEL DRY AIR WILL OVERSPREAD SE MI BY 12Z. THE RESULTING BRIEF DURATION OF THE SNOW EARLY THIS MORNING WILL KEEP ACCUMS TO AN INCH OR LESS /WITH THE HIGHEST AMOUNTS SOUTH OF I-69/. DESPITE THE LOSS OF MID LEVEL MOISTURE...THERE WILL BE AN ADDITIONAL INFLUX OF LOW LEVEL MOISTURE /SUB 850MB/ DRIVEN INTO SE MI DURING THE MORNING. THIS WILL PROVIDE A GOOD SET UP FOR SOME FREEZING DRIZZLE. THIS AND THE AMOUNT OF FZDZ REPORTS ACROSS WISCONSIN SUPPORT ADDING AREAS OF FZDZ TO THE MORNING FORECAST. BY THE TIME THAT CONDITIONS BECOME OPTIMAL FOR FZDZ...SFC TEMPS SHOULD BE WARMING INTO THE LOWER 30S AND LIKELY ABOVE FREEZING BY NOON. THIS AND THE POTENTIAL SHORT DURATION OF ANY DRIZZLE WILL SUPPORT HOLDING OFF ON ANY TYPE OF WINTER WX ADVISORIES FOR THE TIME BEING. DEEP LAYER MOISTURE WILL ROTATE BACK INTO SE MI THIS AFTERNOON. WITH SOME STEEP MID LEVEL LAPSE RATES AND DIURNAL INSTABILITY...SNOW SHOWER ACTIVITY IS POSSIBLE. THE NAM AND HRRR SUGGEST SOME FGEN DEVELOPMENT ALONG THE MID TROPOSPHERIC FRONT...GENERALLY SOUTH OF THE M 59 CORRIDOR EARLY IN THE AFTERNOON. THIS WILL NOT ONLY WARRANT HIGHER POPS IN THESE LOCALS BUT ALSO SUGGEST SOME ADDITIONAL LIGHT AFTERNOON SNOW ACCUMS /POSSIBLY A HALF INCH/. SFC HIGH PRESSURE WILL EXPAND ACROSS SE TONIGHT AMIDST RISING MID LEVEL HEIGHTS IN THE WAKE OF THE DEPARTING UPPER TROUGH. LOW LEVEL ANTICYCLONIC FLOW AND DRY AIR ADVECTION SHOULD CLEAR THE LOW CLOUDS OUT LATE IN THE NIGHT...SUPPORTING A BRIEF PERIOD OF DECENT RADIATIONAL COOLING. IF THIS COOLING OCCURS A LITTLE EARLIER...LATER SHIFTS WILL HAVE TO CONSIDER ADDING FOG TO THE FORECAST. LONG WAVE RIDGE AMPLIFICATION ACROSS THE ERN US EARLY NEXT WEEK AND THE ESTABLISHMENT OF STRENGTHENING SOUTHWEST FLOW FROM THE SRN PLAINS INTO THE UPPER MIDWEST AND GREAT LAKES WILL SUPPORT A DRAMATIC WARM UP BEGINNING SUNDAY AND PERSISTING THROUGH AT LEAST TUESDAY. DESPITE THE SNOW COVER...THE STRONG LOW LEVEL WARM AIR ADVECTION WITHIN THE WELL MIXED SW FLOW WILL SUPPORT TEMPS ON THE HIGH END OF GUIDANCE /40S SUNDAY...50S MON...60S TUES/. CONSENSUS AMONG THE MEDIUM RANGE MODEL SUITE INDICATE BETTER RAINFALL CHANCES MID TO LATE WEEK AS MUCH DEEPER MOISTURE GETS ADVECTED INTO THE GREAT LAKES. A GOOD DEAL OF FCST UNCERTAINTY REVOLVES AROUND TIMING A BACK DOOR COLD FRONT THROUGH THE AREA NEXT WEEK. MODEL SOLUTIONS DIVERGE WITH RESPECT TO TIMING AND AMPLITUDE OF AN UPPER WAVE TRACKING ACROSS CANADA WHICH RESULTS IN A LARGE SPREAD IN TIMING THIS BACK DOOR COLD FRONT INTO SE MI. IT LOOKS AS THOUGH THIS FRONT WILL MOVE THROUGH SOMETIME IN THE WED TO THURS TIME FRAME AND WILL HAVE THE POTENTIAL TO BRING MUCH COOLER LAKE MODIFIED BOUNDARY LAYER AIR INTO THE AREA /WITH WARM MOIST SOUTHWEST FLOW ALOFT STILL PROVING PERIODIC CHANCES FOR RAIN SHOWERS/. MARINE... WINDS WILL REMAIN LIGHT TODAY...GENERALLY UNDER 10 KNOTS...AS LOW PRESSURE SLIDES FROM THE WESTERN GREAT LAKES INTO THE OHIO VALLEY TODAY...AND THEN A RIDGE OF HIGH PRESSURE SHIFTS INTO THE AREA TONIGHT. LOW PRESSURE TRACKING ACROSS HUDSON BAY AND ONTARIO SUNDAY INTO SUNDAY NIGHT WILL THEN PROVIDE A TIGHTER SURFACE PRESSURE GRADIENT OVER THE AREA...CAUSING WINDS TO INCREASE. THE STRONGEST WINDS LOOK TO OCCUR OVER THE OPEN WATERS OF LAKE HURON...WITH SPEEDS INTO THE 20 TO 25 KNOT RANGE. GUSTS SHOULD REMAIN BELOW GALE FORCE HOWEVER AS WARMER AIR SURGING INTO THE AREA WILL PROVIDE A HIGH DEGREE OF STABILITY OVER THE COLD LAKE WATERS. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......SF AVIATION.....HLO DISCUSSION...SC MARINE.......HLO YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
651 AM EST SAT MAR 5 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 445 AM EST SAT MAR 5 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS A RIDGE OVER THE ROCKIES AND A TROF OVER ERN NAMERICA. SHORTWAVE THAT BROUGHT SNOW INTO UPPER MI OVER THE LAST 12HRS OR SO IS TRACKING SE THRU WI. THIS WILL BE THE FINAL SHORTWAVE TO DROP SE THRU THE AREA BEFORE A TRANSITION TO A WARM SPLIT FLOW PATTERN WITH ABOVE NORMAL HEIGHTS AND W TO SW FLOW ACROSS THE UPPER GREAT LAKES NEXT WEEK. RADAR TRENDS OVER THE LAST COUPLE OF HRS SHOW SNOW DIMINISHING OVER UPPER MI...AND UPSTREAM... KDLH RADAR SHOWS VERY LITTLE PCPN REMAINING. THERE WERE OBS AND REPORTS OF SOME -FZDZ EARLIER IN THE NIGHT OVER WRN UPPER MI AND NRN WI AS THE HEAVIER SNOW DEPARTED. RECENTLY...THERE ARE FEWER OBS SHOWING UNKNOWN PCPN...SO -FZDZ MAY BE DIMINISHING. WITH SHORTWAVE CONTINUING SE TODAY...DIMINISHING PCPN WILL END FROM NW TO SE. SOUTHERLY FLOW ON LAKE MI PERSISTS THRU MID TO LATE MORNING WHICH SHOULD HELP WEAKLY LAKE ENHANCED SNOW TO LINGER. THUS...HIGHEST POPS WILL PAINTED OVER THE E THIS MORNING WITH PERHAPS ANOTHER HALF INCH OR SO OF SNOW ACCUMULATION. TO THE W... WILL KEEP A MENTION OF -FZDZ/-SN MAINLY IN THE COUNTIES BORDERING WI FOR THE NEXT FEW HRS. SATELLITE IMAGERY SHOWS CLEARING NOT THAT FAR AWAY ACROSS NRN LAKE SUPERIOR. WITH HIGH PRES RIDGE BUILDING INTO THE UPPER GREAT LAKES THIS AFTN...LOW-LEVEL NORTHERLY WINDS AHEAD OF THE RIDGE WILL DIMINISH. THIS INCREASES THE UNCERTAINTY IN HOW MUCH CLEARING WILL OCCUR...ESPECIALLY SINCE UPSLOPE FLOW OFF THE LAKE UNDER A LOWERING INVERSION SHOULD GREATLY SLOW THE CLEARING PROCESS. KEWEENAW OBVIOUSLY HAS THE BEST CHC OF AT LEAST PARTIALLY CLEARING OUT TODAY GIVEN THE CLOSE PROXIMITY OF CLEAR SKIES ALREADY EARLY THIS MORNING. FOR NOW...FCST WILL SHOW A VERY GRADUAL DECREASE IN CLOUDS FROM THE N AND NW THIS AFTN INTO THIS EVENING. CLOUD FCST INTO TONIGHT REMAINS A BIT TRICKY. IF THE EXTENSIVE LOW CLOUDS ACROSS MN/WI PERSIST THRU THE DAY...THESE CLOUDS MAY MOVE BACK INTO THE AREA TONIGHT ONCE S TO SW FLOW DEVELOPS/INCREASES AFTER THE HIGH PRES RIDGE PASSES. OTHERWISE...PROVIDED MUCH OF TODAYS CLOUD COVER DEPARTS BY EVENING...THERE WILL BE AN OPPORTUNITY FOR TEMPS TO FALL QUICKLY THIS EVENING UNDER LIGHT/CALM WIND. LEANED FCST TO THE COLDER BIAS CORRECTED REGIONAL/GLOBAL CANADIAN MODELS DUE TO THEIR NORMAL SUPERIOR PERFORMANCE IN RADIATIONAL COOLING SITUATIONS. TRADITIONAL COLD SPOTS WILL FALL DOWN INTO THE MID TEENS IF SKIES ARE MOSTLY CLEAR THIS EVENING. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 349 AM EST SAT MAR 5 2016 ADVERTISED EARLY SPRING PREVIEW IS STILL ON TRACK FOR EARLY NEXT WEEK AND BEYOND. SUBSTANTIAL WARM ADVECTION KICKS IN ON SUNDAY. PRESSURE GRADIENT WILL TIGHTEN SIGNIFICANTLY BETWEEN SURFACE LOW/SHORTWAVE MOVING THROUGH NORTHERN ONTARIO AND HIGH PRESSURE ALONG THE EAST COAST. 85H TEMPS CLIMB INTO THE PLUS 5 TO 8C RANGE. EVEN WITH THE STABLE THERMAL PROFILE 92H WINDS ARE FORECAST UP TO 40 KNOTS SO EXPECT WINDS TO BE PRETTY GUSTY. NAM REMAINS CONSISTENT...AND TO A LESSER EXTENT THE GFS...IN SHOWING ENOUGH MOISTENING THROUGH THE DAY THAT THERE MAY EVEN BE SOME LIGHT PRECIPITATION OVER EASTERN AREAS BY LATE IN THE DAY. WILL INTRODUCE SOME SLIGHT CHANCE POPS ACROSS THE EAST FOR SOME LIGHT RAIN/DRIZZLE. TEMPS ON SUNDAY WILL CLIMB INTO THE 40S WEST WHILE LAKE MICHIGAN COOLING WITH THE STRONG SOUTHWESTERLY WINDS WILL KEEP TEMPS IN THE UPPER 30S ACROSS THE EAST. THE BEST CHANCES FOR ANY WIDESPREAD PRECIPITATION...ALBEIT RELATIVELY LIGHT...WILL OCCUR DURING THE MONDAY THROUGH TUESDAY NIGHT TIME PERIOD. WHILE TEMPERATURES WILL BE WELL ABOVE NORMAL...IT WILL PROBABLY BE PRETTY GLOOMY DURING THIS PERIOD. CONTINUED WARM ADVECTION...DEWPOINTS CLIMBING INTO THE 30S AND 40S...AND A MELTING SNOWPACK WILL YIELD PLENTY OF LOW CLOUDS...PATCHY FOG...AND DRIZZLE. SHEARING OUT SHORTWAVE EJECTING WEST OF THE AREA ON TUESDAY WITH SURFACE LOW PASSING NORTHWEST OF LAKE SUPERIOR WILL BRING THE BEST CHANCE OF RAIN ON TUESDAY. WITH DYNAMICAL FORCING ON THE WANE AND LINGERING MID LEVEL DRY AIR ANY PRECIPITATION WILL BE PRETTY LIGHT. AS TRAILING COLD FRONT CROSSES THE AREA LATE TUESDAY AND WITH FAIRLY STEEP MID LEVEL LAPSE RATES STILL CANNOT RULE THE POSSIBILITY OF A THUNDERSTORM ALONG THE FRONT. HOWEVER...CAPPING MAY REMAIN TOO STRONG TO ALLOW ANY DEEP CONVECTION. DESPITE THE CLOUDS TEMPERATURES WILL APPROACH 50 FOR MANY ON MONDAY AND INTO THE 50S ON TUESDAY AWAY FROM THE COOLING INFLUENCES OF THE LAKES...ESPECIALLY LAKE MICHIGAN. DRIER AIR ALONG WITH SOME COOLING BEHIND THE FRONT WILL ALLOW PRECIPITATION TO COME TO AN END TUESDAY NIGHT. FORECAST LOOKS DRY DURING THE WEDNESDAY THROUGH FRIDAY PERIOD. AFTER A BRIEF COOL DOWN WEDNESDAY...ALTHOUGH STILL ABOVE NORMAL...MILD PACIFIC AIR WILL RETURN FOR LATE IN THE WEEK WITH DAYTIME TEMPS ONCE AGAIN APPROACHING 50 FOR MANY BY LATE IN THE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 650 AM EST SAT MAR 5 2016 WITH LOW PRES DEPARTING TO THE SE AND DRIER AIR GRADUALLY FILTERING INTO UPPER MI FROM THE N AND NW...EXPECT IMPROVING CONDITIONS TODAY. AT KIWD...INITIAL IFR/LIFR CONDITIONS WILL IMPROVE TO MVFR BY LATE MORNING...THEN VFR BY LATE AFTN/EARLY EVENING IF NOT SOONER. CIGS HAVE ALREADY RISEN TO VFR AT KCMX AS DRIER AIR HAS SLIPPED INTO THE KEWEENAW. HOWEVER...SOME PERIODS OF MVFR CIGS ARE STILL EXPECTED THIS MORNING. AT KSAW...MVFR CIGS WILL PROBABLY PERSIST UNTIL LATE AFTN/EARLY EVENING UNDER UPSLOPE FLOW OFF LAKE SUPERIOR. HOWEVER...NOT OUT OF THE QUESTION FOR SOME PERIODS OF IFR THIS MORNING UNDER UPSLOPE FLOW AND ALSO FOR VFR CONDITIONS TO DEVELOP SOONER THIS AFTN. AFTER HIGH PRES RIDGE PASSES THIS EVENING...WINDS WILL BEGIN TO INCREASE ABOVE SFC BASED INVERSION. THIS WILL LEAD TO LLWS AT KIWD LATE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 445 AM EST SAT MAR 5 2016 EXPECT LIGHT WINDS...MOSTLY UNDER 15KT TO BE THE RULE ACROSS LAKE SUPERIOR TODAY UNDER A WEAK PRES GRADIENT WITH HIGH PRES RIDGE ARRIVING IN THE AFTN. PRES GRADIENT WILL THEN TIGHTENT TONIGHT AND SUN AS THE RIDGE SHIFTS TO THE E COAST AND A LOW PRES MOVES ACROSS SCNTRL CANADA. S TO SW WINDS WILL RAMP UP TO AS HIGH AS 30KT LATE TONIGHT AND SUN. NOT OUT OF THE QUESTION THAT A FEW GALE FORCE GUSTS COULD OCCUR OVER EASTERN LAKE SUPERIOR SUN. WINDS WILL THEN DIMINISH SUN NIGHT/MON UNDER A WEAKENING PRES GRADIENT. AS LOW PRES TRACKS FROM THE WESTERN PLAINS MON MORNING TO NORTHERN ONTARIO TUE AND QUEBEC WED...WINDS WILL AGAIN INCREASE TO 15-25KT AT TIMES TUE/WED. SOME FOG MAY FORM OVER THE CHILLY WATERS MON NIGHT/TUE AS MOISTER AIR MOVES INTO THE UPPER LAKES AHEAD OF THE LOW PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...MZ AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
505 AM EST SAT MAR 5 2016 .AVIATION... INITIAL ROUND OF SNOW WILL EXIT EAST OF THE TERMINAL BY 12Z. SURFACE OBSERVATIONS AND RADAR IMAGERY THEN SUPPORT IFR CEILINGS...FOG AND LIGHT FREEZING DRIZZLE SPREADING INTO THE AREA FROM OVER WISCONSIN AS LOW PRESSURE OVER THE WESTERN GREAT LAKES TRACKS TOWARDS THE OHIO VALLEY. THE DRIZZLE AND FOG WILL OCCUR AS DRIER AIR IN THE MID-LEVELS ARRIVES...WHICH WILL ALSO MAKE THE THREAT FOR SNOW DURING THIS TIMEFRAME VERY LOW. ADDITIONAL MOISTURE WILL WRAP IN AS LOW PRESSURE TRACKS SOUTH OF THE AREA THIS AFTERNOON...ALLOWING A SECOND ROUND OF LIGHT SNOW TO AFFECT THE TERMINALS MAINLY FROM PTK SOUTH. ADDITIONAL ACCUMULATIONS SHOULD BE UNDER 0.5 INCHES. CEILINGS SHOULD REMAIN IFR HOWEVER. A RIDGE OF HIGH PRESSURE WILL SLIDE IN OVERHEAD TONIGHT...ENDING THE THREAT FOR PRECIPITATION. CALM CONDITIONS WILL THEN PROMOTE THE DEVELOPMENT OF FOG AND STRATUS OVERNIGHT. WILL FAVOR FOG FROM FNT SOUTH...CLOSER TO THE RIDGE AXIS WHERE WINDS SHOULD BE CALM...AND LEAN MORE TOWARDS STRATUS ALONG THE NORTHERN PERIPHERY OF THE RIDGE AXIS AT MBS OVERNIGHT. FOR DTW...IFR CEILINGS...BR...AND -FZDZ OBSERVED UPSTREAM OVER WISCONSIN AND FAR WESTERN MICHIGAN SHOULD MOVE WEST TOWARDS DTW EARLY IN THE TAF PERIOD. THIS SHOULD LAST INTO AFTERNOON UNTIL ADDITIONAL MOISTURE WORKS INTO THE AREA...BRINGING ANOTHER ROUND OF SNOW TO THE AREA. ACCUMULATIONS UP TO 0.5 INCHES ARE EXPECTED. IFR CONDITIONS SHOULD LIFT THIS EVENING...WITH MVFR FOG FILLING IN OVERNIGHT AS HIGH PRESSURE AND CALM CONDITIONS SPREAD INTO LOWER MICHIGAN. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CEILINGS AOB 5000 FEET TODAY AND THIS EVENING. LOW OVERNIGHT. * MEDIUM FOR FREEZING DRIZZLE AS PRECIPITATION TYPE BETWEEN 12- 17Z. HIGH FOR SNOW AS PRECIPITATION TYPE THIS AFTERNOON. && .PREV DISCUSSION...ISSUED 309 AM EST SAT MAR 5 2016 DISCUSSION... LIGHT SNOW OVERSPREAD MUCH OF SE MI OVERNIGHT. SFC OBSERVATIONS AND RADAR SUGGEST SOME LOCALS /PARTICULARLY SOUTH OF THE I-69 CORRIDOR/ HAVE BEEN EXPERIENCING INTERVALS OF FAIRLY GOOD SNOWFALL RATES. THIS SNOW IS OCCURRING WITHIN A REGION OF MID LEVEL ISENTROPIC ASCENT AHEAD OF AN UPPER SHORT WAVE NOW OVER WISCONSIN...AIDED BY A LEAD SHORT WAVE IMPULSE NOW ROTATING INTO SE MI. THE UPSTREAM MID LEVEL TROUGH WILL ROTATE INTO THE OHIO VALLEY BY AFTERNOON...WITH THE ASSOCIATED SFC LOW /OVER CNTRL WISCONSIN AS OF 07Z/ TRACKING INTO NRN INDIANA BY EARLY AFTERNOON. THE REGIONAL WATER VAPOR LOOP SHOWS THE AXIS OF DEEP LAYER MOISTURE ALREADY OVER SE MI...WITH MID LEVEL DRY AIR FAST MOVING INTO SW LOWER MI. THIS LOSS OF MID LEVEL MOISTURE IS LEADING TO AN ABRUPT END TO THE LIGHT SNOW OVER SW LOWER ATTM. MODEL RH PROGS AND SOUNDINGS /WITH SUPPORT FROM THE WATER VAPOR LOOP/ INDICATE THE MID LEVEL DRY AIR WILL OVERSPREAD SE MI BY 12Z. THE RESULTING BRIEF DURATION OF THE SNOW EARLY THIS MORNING WILL KEEP ACCUMS TO AN INCH OR LESS /WITH THE HIGHEST AMOUNTS SOUTH OF I-69/. DESPITE THE LOSS OF MID LEVEL MOISTURE...THERE WILL BE AN ADDITIONAL INFLUX OF LOW LEVEL MOISTURE /SUB 850MB/ DRIVEN INTO SE MI DURING THE MORNING. THIS WILL PROVIDE A GOOD SET UP FOR SOME FREEZING DRIZZLE. THIS AND THE AMOUNT OF FZDZ REPORTS ACROSS WISCONSIN SUPPORT ADDING AREAS OF FZDZ TO THE MORNING FORECAST. BY THE TIME THAT CONDITIONS BECOME OPTIMAL FOR FZDZ...SFC TEMPS SHOULD BE WARMING INTO THE LOWER 30S AND LIKELY ABOVE FREEZING BY NOON. THIS AND THE POTENTIAL SHORT DURATION OF ANY DRIZZLE WILL SUPPORT HOLDING OFF ON ANY TYPE OF WINTER WX ADVISORIES FOR THE TIME BEING. DEEP LAYER MOISTURE WILL ROTATE BACK INTO SE MI THIS AFTERNOON. WITH SOME STEEP MID LEVEL LAPSE RATES AND DIURNAL INSTABILITY...SNOW SHOWER ACTIVITY IS POSSIBLE. THE NAM AND HRRR SUGGEST SOME FGEN DEVELOPMENT ALONG THE MID TROPOSPHERIC FRONT...GENERALLY SOUTH OF THE M 59 CORRIDOR EARLY IN THE AFTERNOON. THIS WILL NOT ONLY WARRANT HIGHER POPS IN THESE LOCALS BUT ALSO SUGGEST SOME ADDITIONAL LIGHT AFTERNOON SNOW ACCUMS /POSSIBLY A HALF INCH/. SFC HIGH PRESSURE WILL EXPAND ACROSS SE TONIGHT AMIDST RISING MID LEVEL HEIGHTS IN THE WAKE OF THE DEPARTING UPPER TROUGH. LOW LEVEL ANTICYCLONIC FLOW AND DRY AIR ADVECTION SHOULD CLEAR THE LOW CLOUDS OUT LATE IN THE NIGHT...SUPPORTING A BRIEF PERIOD OF DECENT RADIATIONAL COOLING. IF THIS COOLING OCCURS A LITTLE EARLIER...LATER SHIFTS WILL HAVE TO CONSIDER ADDING FOG TO THE FORECAST. LONG WAVE RIDGE AMPLIFICATION ACROSS THE ERN US EARLY NEXT WEEK AND THE ESTABLISHMENT OF STRENGTHENING SOUTHWEST FLOW FROM THE SRN PLAINS INTO THE UPPER MIDWEST AND GREAT LAKES WILL SUPPORT A DRAMATIC WARM UP BEGINNING SUNDAY AND PERSISTING THROUGH AT LEAST TUESDAY. DESPITE THE SNOW COVER...THE STRONG LOW LEVEL WARM AIR ADVECTION WITHIN THE WELL MIXED SW FLOW WILL SUPPORT TEMPS ON THE HIGH END OF GUIDANCE /40S SUNDAY...50S MON...60S TUES/. CONSENSUS AMONG THE MEDIUM RANGE MODEL SUITE INDICATE BETTER RAINFALL CHANCES MID TO LATE WEEK AS MUCH DEEPER MOISTURE GETS ADVECTED INTO THE GREAT LAKES. A GOOD DEAL OF FCST UNCERTAINTY REVOLVES AROUND TIMING A BACK DOOR COLD FRONT THROUGH THE AREA NEXT WEEK. MODEL SOLUTIONS DIVERGE WITH RESPECT TO TIMING AND AMPLITUDE OF AN UPPER WAVE TRACKING ACROSS CANADA WHICH RESULTS IN A LARGE SPREAD IN TIMING THIS BACK DOOR COLD FRONT INTO SE MI. IT LOOKS AS THOUGH THIS FRONT WILL MOVE THROUGH SOMETIME IN THE WED TO THURS TIME FRAME AND WILL HAVE THE POTENTIAL TO BRING MUCH COOLER LAKE MODIFIED BOUNDARY LAYER AIR INTO THE AREA /WITH WARM MOIST SOUTHWEST FLOW ALOFT STILL PROVING PERIODIC CHANCES FOR RAIN SHOWERS/. MARINE... WINDS WILL REMAIN LIGHT TODAY...GENERALLY UNDER 10 KNOTS...AS LOW PRESSURE SLIDES FROM THE WESTERN GREAT LAKES INTO THE OHIO VALLEY TODAY...AND THEN A RIDGE OF HIGH PRESSURE SHIFTS INTO THE AREA TONIGHT. LOW PRESSURE TRACKING ACROSS HUDSON BAY AND ONTARIO SUNDAY INTO SUNDAY NIGHT WILL THEN PROVIDE A TIGHTER SURFACE PRESSURE GRADIENT OVER THE AREA...CAUSING WINDS TO INCREASE. THE STRONGEST WINDS LOOK TO OCCUR OVER THE OPEN WATERS OF LAKE HURON...WITH SPEEDS INTO THE 20 TO 25 KNOT RANGE. GUSTS SHOULD REMAIN BELOW GALE FORCE HOWEVER AS WARMER AIR SURGING INTO THE AREA WILL PROVIDE A HIGH DEGREE OF STABILITY OVER THE COLD LAKE WATERS. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....HLO DISCUSSION...SC MARINE.......HLO YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BISMARCK ND
933 AM CST SAT MAR 5 2016 .UPDATE... ISSUED AT 931 AM CST SAT MAR 5 2016 NO MAJOR CHANGES TO THE FORECAST WERE WARRANTED SO FAR THIS MORNING. MAIN CHANGE WAS TO SLOW DOWN THE CLEARING FROM JAMESTOWN EASTWARD WHERE THE CLOUDS HAVE BEEN A LITTLE SLOW TO MOVE OUT. THE LATEST SHORT TERM MODELS STILL SHOW THE CLOUDS EXITING...WITH ONLY SCATTERED HIGH CLOUDS LATER THIS AFTERNOON. UPDATE ISSUED AT 646 AM CST SAT MAR 5 2016 NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE CYCLE...BUT WE DID DELAY THE EXIT OF LOW CLOUDS /STRATUS/ IN THE SOUTHERN JAMES RIVER VALLEY A BIT UNTIL MID MORNING BASED ON SATELLITE AND HRRR TRENDS. OTHERWISE...THE 12 UTC BISMARCK SOUNDING REVEALED PLENTY OF MID-LEVEL WARMING AND DRYING SINCE LAST EVENING...SUPPORTING THE GOING WARM FORECAST FOR TODAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 344 AM CST SAT MAR 5 2016 WARMER...BREEZY...AND DRY CONDITIONS HIGHLIGHT THE SHORT TERM PERIOD. SOUTHERLY WINDS/WARM AIR ADVECTION DEVELOP TODAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A MINOR COLD FRONT PASSES THROUGH SATURDAY NIGHT. THE LATEST WATER VAPOR AND IR IMAGERY LOOP INDICATE MID/UPPER LEVEL RIDGING OVER THE NORTHERN ROCKIES THIS MORNING WITH SCATTERED HIGH CLOUDS RIDING ATOP THE RIDGE INTO WESTERN NORTH DAKOTA. FOG/STRATUS IMAGERY LOOP CONTINUES TO SHOW AN AREA OF LOW CLOUDS IN THE JAMES RIVER VALLEY. THIS IS FORECAST TO EXIT BY 12Z SATURDAY. THE TREND WILL BE FOR THE UPPER RIDGE TO SHIFT EAST AND GRADUALLY FLATTEN/BECOME BROADER THROUGH TONIGHT...AS A PAIR OF SHORTWAVES PUSH INTO THE RIDGE. THE FIRST SHORTWAVE IS BEST DEFINED AT 700MB AND CURRENTLY IS LOCATED IN SOUTH CENTRAL MONTANA. THIS WILL STEADILY MOVE INTO SOUTH CENTRAL NORTH DAKOTA BY 00Z SUNDAY. NOT EXPECTING ANYTHING SIGNIFICANT AS THERE IS NO SURFACE LOW REFLECTION. THIS SHORTWAVE WILL MAINLY SERVE TO FLATTEN THE OVERALL HEIGHT FIELD/RIDGE AXIS AS IT PROPAGATES THROUGH. THE SECOND SHORTWAVE NOW INTO SOUTHWEST BRITISH COLUMBIA WILL SLIDE ACROSS SOUTHERN CANADA INDUCING A SURFACE LOW/COLD FRONT IN SOUTHERN ALBERTA THIS AFTERNOON. IT WILL THEN MOVE EAST AND GRAZE NORTH DAKOTA SATURDAY NIGHT WITH A WIND SHIFT AND WEAK COLD AIR ADVECTION. FOR TODAY...THE CANOPY OF THE 1000-500MB THICKNESS RIDGE HOVERS OVER THE SOUTHWEST...RESULTING IN THE WARMEST/DRIEST AIR TO RESIDE HERE. AFTERNOON HIGHS WILL CLIMB INTO THE MID/UPPER 60S SOUTHWEST. ELSEWHERE EXPECT HIGHS IN THE 50S CENTRAL TO 40S FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY. UTILIZED A 50/50 COMBINATION BLEND OF THE HRRR EXPERIMENTAL 2M HOURLY RH FIELD AND OFFICIAL GRIDDED FORECAST TO YIELD MINIMUM RELATIVE HUMIDITIES IN THE 15 TO 20 PERCENT RANGE SOUTHWEST. THIS SEEMS LOGICAL GIVEN UPSTREAM FLOW AND RELATED AIRMASS FROM FRIDAY HAVING ADVECTED IN FROM WYOMING. THE HRRR RH FIELD VERIFIED WELL IN NORTH DAKOTA AS WELL AS UPSTREAM IN THE LAST 24HR. WINDS TODAY WILL BE WEAKEST IN THE FAR SOUTHWEST WHERE AFTERNOON RELATIVE HUMIDITIES WILL BE LOWEST. WINDS WILL STEADILY INCREASE INTO THE BREEZY CATEGORY (15-25MPH) FOR CENTRAL NORTH DAKOTA THIS AFTERNOON. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 344 AM CST SAT MAR 5 2016 ABOVE-NORMAL TEMPERATURES AND MAINLY DRY WEATHER WILL PREVAIL FOR THE NEXT WEEK. ON SUNDAY...DAILY RECORD HIGHS MAY FALL GIVEN 850-MB TEMPERATURES IN THE 97.5 TO 99TH PERCENTILE FOR THIS TIME OF THE YEAR...NEARLY FULL SUNSHINE...DRY SOILS...AND DORMANT VEGETATION...ALL OF WHICH WILL SUPPORT EFFICIENT HEATING. WE ARE STILL CALLING FOR HIGHS IN THE 60S F IN MOST AREAS AND A FEW 70 F READINGS ARE LIKELY ACROSS SOUTHWEST AND SOUTH CENTRAL ND. MIXING IS FORECAST TO BE SOMEWHAT MORE SHALLOW THAN ON SATURDAY BASED ON 00 UTC MODEL SOUNDINGS AND THAT RAISES A BIT OF CONCERN FOR WARMING...BUT MORE THAN LIKELY THAT WILL JUST ENSURE WINDS WILL STAY RELATIVELY LIGHT. SUNDAY IS APT TO BE A TRULY STELLAR EARLY MARCH DAY. THEREAFTER...A PACIFIC COLD FRONT WILL CROSS THE AREA MONDAY AS A WEAK SHORTWAVE TROUGH EJECTS ACROSS THE REGION OUT OF A SPLITTING TROUGH THAT WILL KEEP ITS CORE WELL SOUTH IN TX AND MEXICO. WE DO HAVE A LOW-GRADE SHOWER CHANCE IN THE FORECAST BEHIND THE FRONT MONDAY THROUGH EARLY TUESDAY. PROGRESSIVE...QUASI-ZONAL FLOW WILL THEN OCCUR IN THE NORTHERN STREAM THE MIDDLE PART OF THE WEEK AND THAT WILL YIELD MAINLY DRY WEATHER. THE 00 UTC GFS AND ECMWF BOTH SUGGEST RIDGING REBUILDING AGAIN BY LATE WEEK....WITH THE 00 UTC NAEFS EVEN CALLING FOR 850-MB TEMPERATURE ANOMALIES IN THE 90TH PERCENTILE BY FRIDAY. THAT IS A SIGNIFICANT SIGNAL IN A LONG-LEAD ENSEMBLE FORECAST...SUGGESTING HIGHS COULD ONCE AGAIN END UP WELL INTO THE 60S F /WARMER THAN OUR CURRENT FORECAST/ BY LATE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 931 AM CST SAT MAR 5 2016 ALL TERMINALS IN VFR STATUS THROUGH THE TAF PERIOD EXCEPT KJMS...WHERE MVFR CIGS WILL LINGER UNTIL 17Z SATURDAY...THEN VFR. BREEZY SSE/S WINDS BETWEEN 15KT AND 25KT AT KBIS/KJMS DURING THE AFTERNOON. && .FIRE WEATHER... ISSUED AT 931 AM CST SAT MAR 5 2016 DESPITE MINIMUM RELATIVE HUMIDITIES IN THE 15 TO 20 PERCENT RANGE OVER SOUTHWEST ND TODAY...WINDS WILL NOT BE STRONG ENOUGH FOR CRITICAL FIRE WEATHER CRITERIA TO BE MET. SUSTAINED SOUTHERLY WINDS WILL WEAKEN THROUGH THE AFTERNOON TO BETWEEN 10 AND 15 MPH...JUST AS RELATIVE HUMIDITIES REACH THEIR MINIMUM AS MENTIONED ABOVE. THUS WILL NOT ISSUE ANY HIGHLIGHTS AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CK SHORT TERM...KS LONG TERM...CJS AVIATION...KS FIRE WEATHER...KS/CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
646 AM CST SAT MAR 5 2016 .UPDATE... ISSUED AT 646 AM CST SAT MAR 5 2016 NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE CYCLE...BUT WE DID DELAY THE EXIT OF LOW CLOUDS /STRATUS/ IN THE SOUTHERN JAMES RIVER VALLEY A BIT UNTIL MID MORNING BASED ON SATELLITE AND HRRR TRENDS. OTHERWISE...THE 12 UTC BISMARCK SOUNDING REVEALED PLENTY OF MID-LEVEL WARMING AND DRYING SINCE LAST EVENING...SUPPORTING THE GOING WARM FORECAST FOR TODAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 344 AM CST SAT MAR 5 2016 WARMER...BREEZY...AND DRY CONDITIONS HIGHLIGHT THE SHORT TERM PERIOD. SOUTHERLY WINDS/WARM AIR ADVECTION DEVELOP TODAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A MINOR COLD FRONT PASSES THROUGH SATURDAY NIGHT. THE LATEST WATER VAPOR AND IR IMAGERY LOOP INDICATE MID/UPPER LEVEL RIDGING OVER THE NORTHERN ROCKIES THIS MORNING WITH SCATTERED HIGH CLOUDS RIDING ATOP THE RIDGE INTO WESTERN NORTH DAKOTA. FOG/STRATUS IMAGERY LOOP CONTINUES TO SHOW AN AREA OF LOW CLOUDS IN THE JAMES RIVER VALLEY. THIS IS FORECAST TO EXIT BY 12Z SATURDAY. THE TREND WILL BE FOR THE UPPER RIDGE TO SHIFT EAST AND GRADUALLY FLATTEN/BECOME BROADER THROUGH TONIGHT...AS A PAIR OF SHORTWAVES PUSH INTO THE RIDGE. THE FIRST SHORTWAVE IS BEST DEFINED AT 700MB AND CURRENTLY IS LOCATED IN SOUTH CENTRAL MONTANA. THIS WILL STEADILY MOVE INTO SOUTH CENTRAL NORTH DAKOTA BY 00Z SUNDAY. NOT EXPECTING ANYTHING SIGNIFICANT AS THERE IS NO SURFACE LOW REFLECTION. THIS SHORTWAVE WILL MAINLY SERVE TO FLATTEN THE OVERALL HEIGHT FIELD/RIDGE AXIS AS IT PROPAGATES THROUGH. THE SECOND SHORTWAVE NOW INTO SOUTHWEST BRITISH COLUMBIA WILL SLIDE ACROSS SOUTHERN CANADA INDUCING A SURFACE LOW/COLD FRONT IN SOUTHERN ALBERTA THIS AFTERNOON. IT WILL THEN MOVE EAST AND GRAZE NORTH DAKOTA SATURDAY NIGHT WITH A WIND SHIFT AND WEAK COLD AIR ADVECTION. FOR TODAY...THE CANOPY OF THE 1000-500MB THICKNESS RIDGE HOVERS OVER THE SOUTHWEST...RESULTING IN THE WARMEST/DRIEST AIR TO RESIDE HERE. AFTERNOON HIGHS WILL CLIMB INTO THE MID/UPPER 60S SOUTHWEST. ELSEWHERE EXPECT HIGHS IN THE 50S CENTRAL TO 40S FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY. UTILIZED A 50/50 COMBINATION BLEND OF THE HRRR EXPERIMENTAL 2M HOURLY RH FIELD AND OFFICIAL GRIDDED FORECAST TO YIELD MINIMUM RELATIVE HUMIDITIES IN THE 15 TO 20 PERCENT RANGE SOUTHWEST. THIS SEEMS LOGICAL GIVEN UPSTREAM FLOW AND RELATED AIRMASS FROM FRIDAY HAVING ADVECTED IN FROM WYOMING. THE HRRR RH FIELD VERIFIED WELL IN NORTH DAKOTA AS WELL AS UPSTREAM IN THE LAST 24HR. WINDS TODAY WILL BE WEAKEST IN THE FAR SOUTHWEST WHERE AFTERNOON RELATIVE HUMIDITIES WILL BE LOWEST. WINDS WILL STEADILY INCREASE INTO THE BREEZY CATEGORY (15-25MPH) FOR CENTRAL NORTH DAKOTA THIS AFTERNOON. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 344 AM CST SAT MAR 5 2016 ABOVE-NORMAL TEMPERATURES AND MAINLY DRY WEATHER WILL PREVAIL FOR THE NEXT WEEK. ON SUNDAY...DAILY RECORD HIGHS MAY FALL GIVEN 850-MB TEMPERATURES IN THE 97.5 TO 99TH PERCENTILE FOR THIS TIME OF THE YEAR...NEARLY FULL SUNSHINE...DRY SOILS...AND DORMANT VEGETATION...ALL OF WHICH WILL SUPPORT EFFICIENT HEATING. WE ARE STILL CALLING FOR HIGHS IN THE 60S F IN MOST AREAS AND A FEW 70 F READINGS ARE LIKELY ACROSS SOUTHWEST AND SOUTH CENTRAL ND. MIXING IS FORECAST TO BE SOMEWHAT MORE SHALLOW THAN ON SATURDAY BASED ON 00 UTC MODEL SOUNDINGS AND THAT RAISES A BIT OF CONCERN FOR WARMING...BUT MORE THAN LIKELY THAT WILL JUST ENSURE WINDS WILL STAY RELATIVELY LIGHT. SUNDAY IS APT TO BE A TRULY STELLAR EARLY MARCH DAY. THEREAFTER...A PACIFIC COLD FRONT WILL CROSS THE AREA MONDAY AS A WEAK SHORTWAVE TROUGH EJECTS ACROSS THE REGION OUT OF A SPLITTING TROUGH THAT WILL KEEP ITS CORE WELL SOUTH IN TX AND MEXICO. WE DO HAVE A LOW-GRADE SHOWER CHANCE IN THE FORECAST BEHIND THE FRONT MONDAY THROUGH EARLY TUESDAY. PROGRESSIVE...QUASI-ZONAL FLOW WILL THEN OCCUR IN THE NORTHERN STREAM THE MIDDLE PART OF THE WEEK AND THAT WILL YIELD MAINLY DRY WEATHER. THE 00 UTC GFS AND ECMWF BOTH SUGGEST RIDGING REBUILDING AGAIN BY LATE WEEK....WITH THE 00 UTC NAEFS EVEN CALLING FOR 850-MB TEMPERATURE ANOMALIES IN THE 90TH PERCENTILE BY FRIDAY. THAT IS A SIGNIFICANT SIGNAL IN A LONG-LEAD ENSEMBLE FORECAST...SUGGESTING HIGHS COULD ONCE AGAIN END UP WELL INTO THE 60S F /WARMER THAN OUR CURRENT FORECAST/ BY LATE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 646 AM CST SAT MAR 5 2016 ALL TERMINALS IN VFR STATUS THROUGH THE TAF PERIOD EXCEPT KJMS...WHERE MVFR CIGS WILL LINGER UNTIL 16Z SATURDAY...THEN VFR. BREEZY SSE/S WINDS BETWEEN 15KT AND 25KT AT KBIS/KJMS DURING THE AFTERNOON. && .FIRE WEATHER... ISSUED AT 646 AM CST SAT MAR 5 2016 DESPITE MINIMUM RELATIVE HUMIDITIES IN THE 15 TO 20 PERCENT RANGE OVER SOUTHWEST ND TODAY...WINDS WILL NOT BE STRONG ENOUGH FOR CRITICAL FIRE WEATHER CRITERIA TO BE MET. SUSTAINED SOUTHERLY WINDS WILL WEAKEN THROUGH THE AFTERNOON TO BETWEEN 10 AND 15 MPH...JUST AS RELATIVE HUMIDITIES REACH THEIR MINIMUM AS MENTIONED ABOVE. THUS WILL NOT ISSUE ANY HIGHLIGHTS AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CJS SHORT TERM...KS LONG TERM...CJS AVIATION...KS FIRE WEATHER...KS/CJS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
737 AM EST SAT MAR 5 2016 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL MOVE THROUGH THE REGION EARLY TODAY...BEFORE ANOTHER WEAK CLIPPER TYPE SYSTEM BRINGS THE CHANCE FOR MORE LIGHT RAIN OR SNOW LATER TODAY INTO SUNDAY MORNING. A LARGE RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN HALF OF THE CONTINENT DURING THE UPCOMING WEEK. TEMPERATURES WILL SURGE TO WELL ABOVE NORMAL LEVELS STARTING MONDAY...AND LAST THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... REGIONAL RADAR AND INFRARED SATL LOOP INDICATES A LARGE SHIELD OF ALTOSTRATUS SPREADING ACROSS THE WESTERN THIRD OF THE STATE...AND OVER A LAYER OF STRATOCU CLOUDS THAT COVERED THE CENTRAL VALLEYS AND LOCATIONS JUST WEST OF THE SUSQ MAINSTEM. THE RADAR RETURNS LOOK MUCH MORE OMINOUS THAN WHAT WE`RE NOTING AT METAR SITES ACROSS OHIO AND WRN PENN. THE SEVERAL AREAS OF VERY LIGHT SNOW OR FLURRIES WITH VSBYS AOA 7SM ARE SHOWN TO FIZZLE OUT ACROSS WRN PA /FOR THIS MORNING INTO THE MID AFTERNOON HOURS/ BY THE LATEST SVRL RUNS OF THE HRRR AS THE LLVLS WILL STAY DRY WITH DEWPOINTS IN THE MID TEENS TO LOWER 20S. A SLIGHT NUDGE OF FCST TEMPS TOWARD THE LATEST BLENDED MODEL GUIDANCE COMBINED WITH INPUT FROM LATEST LAMP YIELDS MAX TEMPS THIS AFTERNOON RANGING FROM THE L30S ACROSS HE HIGHEST TERRAIN OF THE ALLEGHENIES...TO ARND 40F ACROSS THE SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE BULK OF THE LIGHT SNOW /WITH THE EMPHASIS ON THE WORD LIGHT/ WILL ARRIVE VERY LATE TODAY ACROSS THE WEST...AND EARLY TONIGHT ACROSS CENTRAL AND ERN PENN WITH THE PASSAGE OF A WEAK /1016-1018 MB/ SFC LOW AND ASSOC WEAK WAA. CONSENSUS MODEL QPF IS JUST A FEW...TO SVRL HUNDREDTHS OF AN INCH...WHICH LEADS TO SNOWFALL AMOUNTS SIMILAR...IF NOT LIGHTER IN MOST AREAS THAN WHAT OCCURRED ABOUT 48 HOURS PRIOR - THURSDAY NIGHT INTO FRIDAY MORNING. THE LAURELS COULD BE THE EXCEPTION WITH THE POTENTIAL FOR AN INCH OR TWO OF SNOW ACCUMULATION BY EARLY SUNDAY...CONSIDERING THAT THIS IS THE TARGET AREA FOR THE HRRR`S QPF - AS A RESULT OF BEING CLOSEST TO THE SFC LOW TRACK ACROSS WEST VA. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AFTER SOME MORNING CLOUDS...AND FLURRIES ACROSS THE FAR SE DURING THE MORNING...LOOK FOR BRIGHTENING SKIES BUT STILL CHILLY CONDITIONS FOR LATE SUNDAY MORNING AND SUNDAY AFTERNOON AS HIGH PRES BUILDS IN FROM THE WEST WITH LIGHT NW SFC FLOW. BROAD CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP DURING THE FIRST HALF OF THE UPCOMING WEEK...AS AN ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 12Z ECENS. TEMPS WILL TAKE A RUN AT 70F BY WED OVR SOUTHERN PA. MODELS ARE IN BETTER AGREEMENT ON BRINGING A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF THROUGH PA BY MIDWEEK...AS HIGH PRESSURE TRACKING EASTWARD ACROSS CANADA WILL NUDGE THE FRONT SOUTHWARD AND PIVOT IT FROM MORE OF A N-S ORIENTATION TO A W-E DIRECTION. THIS COULD BRING THE NEXT BEST CHANCE FOR PRECIPITATION AS WEAK WAVES COULD RIPPLE TOWARD PA ALONG THE PORTION OF THE /WARM/ FRONT OVER THE OHIO VALLEY. GIVEN THE STRONG WAA IT LOOKS TO BE ALL RAIN...WITH PRECIP BRACKETED BETWEEN LATE IN THE DAY WED AND FRI. THE GFS IS MORE AGGRESSIVE WITH ONSET OF PRECIP AND QPF AMOUNTS THAN THE ECMWF...BUT EITHER WAY IT LOOKS TO BE A SHOWERY END TO THE WEEK AND TEMPS GRADUALLY COOL BACK DOWN BUT REMAIN ABOVE NORMAL. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... FOR THE 05/12Z TAFS THROUGH 06/12Z ISSUED AT 735 AM EST SAT MAR 5 2016 MVFR TO LOW VFR CIGS /2500-5000FT AGL/ WILL PREVAIL TODAY WITH VERY LIGHT SNOW/FLURRIES OVER THE WESTERN AIRSPACE. LOW PRESSURE TRACKING SOUTHEAST FROM WI THRU WV/KY WILL BRING LIGHT SNOW AND MVFR VIS THIS EVENING THROUGH TONIGHT INTO EARLY SUNDAY MORNING. HIGHEST CONFIDENCE IN IFR IS AT JST. PATTERN FAVORS STUBBORN LOW CLOUDS GETTING TRAPPED UNDER RIDGE OF HIGH PRESSURE/SUBSIDENCE INVERSION WITH LOW CIGS CONTINUING INTO SUNDAY MORNING. OUTLOOK...SUNDAY-WEDNESDAY SUN...MVFR CIGS BECOMING VFR. NO SIG WX. MON-TUE...VFR/NO SIG WX. WED...LOW CIGS/RAIN POSSIBLE NORTHWEST AIRSPACE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/RXR AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
602 AM EST SAT MAR 5 2016 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL MOVE THROUGH THE REGION EARLY TODAY...BEFORE ANOTHER WEAK CLIPPER TYPE SYSTEM BRINGS THE CHANCE FOR MORE LIGHT RAIN OR SNOW LATER TODAY INTO SUNDAY MORNING. A LARGE RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN HALF OF THE CONTINENT DURING THE UPCOMING WEEK. TEMPERATURES WILL SURGE TO WELL ABOVE NORMAL LEVELS STARTING MONDAY...AND LAST THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... REGIONAL RADAR AND INFRARED SATL LOOP INDICATES A LARGE SHIELD OF ALTOSTRATUS SPREADING ACROSS THE WESTERN THIRD OF THE STATE...AND OVER A LAYER OF STRATOCU CLOUDS THAT COVERED THE CENTRAL VALLEYS AND LOCATIONS JUST WEST OF THE SUSQ MAINSTEM. THE RADAR RETURNS LOOK MUCH MORE OMINOUS THAN WHAT WE`RE NOTING AT METAR SITES ACROSS OHIO AND WRN PENN. THE SEVERAL AREAS OF VERY LIGHT SNOW OR FLURRIES WITH VSBYS AOA 7SM ARE SHOWN TO FIZZLE OUT ACROSS WRN PA /FOR THIS MORNING INTO THE MID AFTERNOON HOURS/ BY THE LATEST SVRL RUNS OF THE HRRR AS THE LLVLS WILL STAY DRY WITH DEWPOINTS IN THE MID TEENS TO LOWER 20S. A SLIGHT NUDGE OF FCST TEMPS TOWARD THE LATEST BLENDED MODEL GUIDANCE COMBINED WITH INPUT FROM LATEST LAMP YIELDS MAX TEMPS THIS AFTERNOON RANGING FROM THE L30S ACROSS HE HIGHEST TERRAIN OF THE ALLEGHENIES...TO ARND 40F ACROSS THE SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE BULK OF THE LIGHT SNOW /WITH THE EMPHASIS ON THE WORD LIGHT/ WILL ARRIVE VERY LATE TODAY ACROSS THE WEST...AND EARLY TONIGHT ACROSS CENTRAL AND ERN PENN WITH THE PASSAGE OF A WEAK /1016-1018 MB/ SFC LOW AND ASSOC WEAK WAA. CONSENSUS MODEL QPF IS JUST A FEW...TO SVRL HUNDREDTHS OF AN INCH...WHICH LEADS TO SNOWFALL AMOUNTS SIMILAR...IF NOT LIGHTER IN MOST AREAS THAN WHAT OCCURRED ABOUT 48 HOURS PRIOR - THURSDAY NIGHT INTO FRIDAY MORNING. THE LAURELS COULD BE THE EXCEPTION WITH THE POTENTIAL FOR AN INCH OR TWO OF SNOW ACCUMULATION BY EARLY SUNDAY...CONSIDERING THAT THIS IS THE TARGET AREA FOR THE HRRR`S QFP - AS A RESULT OF BEING CLOSEST TO THE SFC LOW TRACK ACROSS WEST VA. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AFTER SOME MORNING CLOUDS...AND FLURRIES ACROSS THE FAR SE DURING THE MORNING...LOOK FOR BRIGHTENING SKIES BUT STILL CHILLY CONDITIONS FOR LATE SUNDAY MORNING AND SUNDAY AFTERNOON AS HIGH PRES BUILDS IN FROM THE WEST WITH LIGHT NW SFC FLOW. BROAD CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP DURING THE FIRST HALF OF THE UPCOMING WEEK...AS AN ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 12Z ECENS. TEMPS WILL TAKE A RUN AT 70F BY WED OVR SOUTHERN PA. MODELS ARE IN BETTER AGREEMENT ON BRINGING A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF THROUGH PA BY MIDWEEK...AS HIGH PRESSURE TRACKING EASTWARD ACROSS CANADA WILL NUDGE THE FRONT SOUTHWARD AND PIVOT IT FROM MORE OF A N-S ORIENTATION TO A W-E DIRECTION. THIS COULD BRING THE NEXT BEST CHANCE FOR PRECIPITATION AS WEAK WAVES COULD RIPPLE TOWARD PA ALONG THE PORTION OF THE /WARM/ FRONT OVER THE OHIO VALLEY. GIVEN THE STRONG WAA IT LOOKS TO BE ALL RAIN...WITH PRECIP BRACKETED BETWEEN LATE IN THE DAY WED AND FRI. THE GFS IS MORE AGGRESSIVE WITH ONSET OF PRECIP AND QPF AMOUNTS THAN THE ECMWF...BUT EITHER WAY IT LOOKS TO BE A SHOWERY END TO THE WEEK AND TEMPS GRADUALLY COOL BACK DOWN BUT REMAIN ABOVE NORMAL. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... FOR THE 05/06Z TAFS THROUGH 06/06Z ISSUED AT 135 AM EST SAT MAR 5 2016 LOW CLOUDS TRAPPED UNDERNEATH SUBSIDENCE INVERSION WILL KEEP MVFR TO LOW VFR CIGS /1.5-4KFT AGL/ IN PLACE THIS MORNING ACROSS THE WRN 2/3 OF THE AIRSPACE. VFR ALONG/EAST OF IPT-MDT LINE WITH FEW- SCT CIGS AT 5KFT. LOW PRESSURE TRACKING SOUTHEAST FROM WI THRU WV WILL BRING LIGHT SNOW AND REDUCED CONDITIONS LATER THIS AFTERNOON INTO TONIGHT. HIGHEST CONFIDENCE IN IFR IS AT JST. OUTLOOK...SUNDAY-WEDNESDAY SUN...MVFR CIGS WEST BECOMING VFR. NO SIG WX. MON-TUE...VFR/NO SIG WX. WED...VFR. RAIN POSSIBLE NORTHWEST AIRSPACE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/RXR AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
256 PM PST SAT MAR 5 2016 .SYNOPSIS... MOIST WEST FLOW WILL LIKELY BRING SHOWERS TO NORTHERN AREAS THIS EVENING... WITH A CHANCE OF SHOWERS ELSEWHERE. A COUPLE OF FRONTAL SYSTEMS WILL THEN BRING RAIN...POSSIBLY HEAVY AT TIMES TO THE REGION. THE FIRST WILL AFFECT THE AREA TONIGHT AND EARLY SUNDAY...AND THE SECOND LATE SUNDAY NIGHT INTO MONDAY. THUNDERSTORMS ARE POSSIBLE MONDAY. HIGH SNOW LEVELS WILL LOWER THROUGH MONDAY. DRY AND WARMER WEATHER IS EXPECTED TUESDAY THROUGH MOST OF THURSDAY. ANOTHER FRONT MAY BRING RAIN TO THE REGION LATE THURSDAY THROUGH FRIDAY. && .SHORT TERM...(TDY-TUE) WARM FRONTAL CLOUDS MOVING OVER THE AREA THIS AFTERNOON. THERE HAS BEEN SOME ON AGAIN OFF AGAIN LIGHT RAIN ACROSS THE AREA DUES TO THE WARM FRONT AS WELL. RADAR SHOWERS A MORE ORGANIZED AREA OF LIGHT RAIN JUST OFF THE CENTRAL COAST ASSOC WITH THE CORE OF THE WARM FRONT. SO CENTRAL COAST SHOULD BE SEEING A MARKED INCREASE IN RAIN LATER THIS AFTERNOON AND EARLY EVENING. WINDS WILL INCREASE ACROSS SLO AND SBA COUNTIES AS THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE FRONT. SOUTH WINDS WILL INCREASE TO 15 TO 25 MPH WITH GUSTS BETWEEN 35 AND 45 MPH. ALL MDLS ARE IN GOOD AGREEMENT THAT A COLD FRONT JUST OFF THE NRN CA COAST AND TRAILING TO THE SW WILL MOVE THROUGH THE AREA LATER TONIGHT AND SUNDAY MORNING. THIS FRONT WILL BRING A 2 TO 4 HOUR PERIOD OF MODERATE TO LOCALLY HEAVY RAIN WITH IT. IT WILL REACH SLO COUNTY JUST BEFORE MIDNIGHT AND EXIT THE COUNTY A FEW HOURS BEFORE SUNRISE...IT WILL ENTER SBA COUNTY JUST AFTER MIDNIGHT AND EXIT THE COUNTY AROUND DAWN...IT WILL ENTER VTA COUNTY JUST BEFORE DAWN AND EXIT THE COUNTY IN THE EARLY MORNING...IT WILL ENTER L.A. COUNTY AT DAWN AND DEPART BY MID MORNING. THE CHANCE OF RAIN WILL GREATLY DIMINISH BEHIND THE FRONT AND ODDS ON IT WILL BE PARTLY CLOUDY AND DRY FOR SUNDAY AFTERNOON. PRECIPITABLE WATER VALUES WITH THIS FRONT WILL BE AROUND 1.3 INCHES WHICH WILL HELP RAINFALL TOTALS. STILL EXPECT 0.25 TO 0.75 INCHES OF RAIN ACROSS L.A. AND VTA COUNTIES...WITH TOTALS OVER 1 INCH POSSIBLE IN THE FOOTHILLS AND MTNS ON AND BELOW S FACING SLOPES. ACROSS SBA AND SLO COUNTIES...EXPECT 0.75 TO 1.5 INCHES OF RAIN...WITH UP TO 2.0 INCHES ACROSS THE HIGHER TERRAIN OF SLO COUNTY AND IN THE MTNS OF SRN SBA COUNTY. SNOW LEVELS WILL BE HIGH WITH THIS FIRST SYSTEM...NEAR 7000 FEET. THERE COULD LOCALLY BE A FEW INCHES OF SNOW AT THE HIGHEST ELEVATIONS. A SECOND COLDER AND MORE DYNAMIC...BUT SLIGHTLY DRIER COLD FRONT WILL WORK ITS WAY TOWARDS CA TONIGHT. THE FRONTS PARENT TROF WILL TAKE ON A SLIGHT NEGATIVE TILT AND SET UP A NICE DIFFLUENT PATTERN OVER THE REGION EARLY MONDAY. THE DYNAMICS AND INSTABILITY WILL ALLOW FOR A CHANCE OF THUNDER MONDAY MORNING AND A SLIGHT CHANCE IN THE COLD AIR BEHIND THE FRONT IN THE AFTERNOON. AS THE SYSTEM TAKES ON A MORE NEGATIVE TILT THE SYSTEM WILL SLOW DOWN SOME. RIGHT NOW IT LOOKS LIKE THE FRONT WILL PASS INTO SLO COUNTY AT ABOUT 3 AM MONDAY MORNING AND EXIT L.A. COUNTY JUST AFTER NOON ON MONDAY AFTERNOON. SINCE THIS SYSTEM WILL BE COLDER...SHOWERY AND MORE DYNAMIC THAN TONIGHT`S STORM RAINFALL RATES WILL BE A LITTLE MORE VARIABLE. MDLS ARE STRUGGLING TO COME INTO AGREEMENT WITH RAINFALL TOTALS WITH THE NAM NOT SEEING AS MUCH RAIN AS THE GFS OR EC SOLUTIONS. RIGHT NOW IT LOOKS LIKE THERE WILL NOT BE MUCH IN THE WAY OF DIFFERENCES BETWEEN THE COUNTIES AND ALL AREAS SHOULD SEE BETWEEN AN INCH AND AN INCH AND A HALF OF RAIN WITH THIS SECOND SYSTEM. ANY THUNDERSTORMS THAT FORM MONDAY COULD PRODUCE RAINFALL RATES THAT EXCEED ONE HALF INCH PER HOUR...WHICH COULD CAUSE SOME PROBLEMS IN AND BELOW RECENT BURN AREAS. SHOWERS WILL END ACROSS THE AREA MONDAY EVENING...EXCEPT ON THE NORTH SLOPES WHERE STRONG MOIST NLY FLOW WILL CREATE UPSLOPE SNOW INTO EARLY TUESDAY. SNOW LEVELS WITH AND BEHIND THIS SECOND FRONT WILL BE QUITE A BIT LOWER... POSSIBLY DOWN TO 4000 TO 5000 FEET MONDAY AND MON NIGHT. THIS COULD CAUSE TRAVEL PROBLEMS IN THE GRAPEVINE PORTION OF INTERSTATE 5. RIGHT NOW IT LOOKS LIKE BETWEEN 4 AND 8 INCHES OF SNOW WILL FALL ABOVE 6000 FEET ON MONDAY. THERE WILL BE SOME FAIRLY STRONG NW WINDS BEHIND THE FRONT AND THERE WILL BE AT LEAST ADVISORY LEVEL WINDS AND POSSIBLY WARNING LEVEL WINDS OVER THE MTNS AND ANTELOPE VLY MONDAY NIGHT AND TUESDAY MORNING. A RIDGE WILL BUILD IN FROM THE SW ON TUESDAY. IT WILL USHER IN A CLEARING AND WARMING TREND. MAX TEMPS WILL RISE TO THE UPPER 60S OR THE LOWER 70S. .LONG TERM...(WED-SAT) ALL MDLS AGREE THAT RIDGING WILL DOMINATE THE AREA WED AND THU. 578 DM HGTS WILL ALL MAX TEMPS TO CLIMB INTO THE LOW TO MID 70S ACROSS MOST OF THE CSTS AND VLYS OR ABOUT 3 TO 6 DEGREES ABOVE NORMAL. ANOTHER COLD FRONT WILL ZIP ACROSS THE AREA ON FRIDAY. ALL MDLS ARE IN PRETTY GOOD AGREEMENT ABOUT THIS AND UPPED THE POPS TO THE CHANCE RANGE. RIGHT NOW IT LOOKS LIKE A MEDIUM KIND OF SYSTEM BUT THESE THINGS CAN CHANGE AS THE MDLS GET A CLOSER AND CLOSER LOOK AT IT. MAX TEMPS WILL NOSE DIVE BY 10 TO 15 DEGREES, THE GFS SEES A STORM ON SATURDAY BUT THE EC AND CANADIAN DO NOT. FOR NOW KEPT THE AREA DRY BUT ONE SHOULD NEVER REALLY HAVE THAT MUCH FAITH IN A DAY 7 FORECAST. && .AVIATION... 05/0000Z WILL BE OUT SHORTLY && .MARINE... 05/200 PM SOUTH WINDS WILL CONTINUE TO INCREASE OVER THE ENTIRE AREA AND SCA CONDITIONS WILL EXIST FROM PIEDRAS BLANCAS TO SAN CLEMENTE ISLAND EXCLUDING THE SANTA BARBARA, SANTA MONICA AND SAN PEDRO BASINS THROUGH TO NIGHT. THE WINDS WILL LIKELY BECOME WEST SUNDAY AND THERE IS A CHANCE SCA CONDITIONS FOR WINDS AND SEAS WILL EXIST OVER THE ENTIRE AREA SUNDAY THROUGH SUNDAY NIGHT. THE WINDS WILL THEN LIKELY BECOME NORTHWEST MONDAY AND THERE IS A CHANCE GALES WILL EXIST OVER THE ENTIRE AREA MONDAY AFTERNOON THROUGH TUESDAY. && .BEACHES... 05/900 AM A LARGE LONG-PERIOD WESTERLY SWELL WILL CONTINUE ACROSS THE COASTAL WATERS THROUGH SUNDAY...GENERATING HIGH SURF CONDITIONS ALONG WEST FACING BEACHES. BY MONDAY INTO EARLY TUESDAY...AN EVEN LARGER LONG-PERIOD WEST SWELL WILL MOVE INTO THE COASTAL WATERS AND SURF CONDITIONS ACROSS LOCAL BEACHES ARE EXPECTED TO BE EVEN HIGHER. A HIGH SURF ADVISORY WILL CONTINUE. HOWEVER...THE POTENTIAL EXISTS FOR SURF HEIGHTS TO EXCEED WARNING LEVELS FOR THE CENTRAL COAST AND WEST FACING BEACHES OF LA/VENTURA COUNTIES. IN ADDITION TO THE VERY LARGE SURF...HIGH TIDES IN THE 6 TO 6.5 FOOT RANG COMBINED WITH GUSTY ONSHORE WINDS AND RAINFALL COULD BRING A THREAT OF MODERATE COASTAL FLOODING TO THESE SAME LOCATIONS. THE COASTAL FLOOD THREAT COULD ALSO CONTINUE INTO TUESDAY MORNING NEAR TIME OF HIGH TIDE. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...HIGH SURF ADVISORY IN EFFECT UNTIL 3 PM PST TUESDAY FOR ZONES 34-35-39>41-87. (SEE LAXCFWLOX). WIND ADVISORY IN EFFECT UNTIL 6 AM PST SUNDAY FOR ZONES 34-35-37-38-51-52. (SEE LAXNPWLOX). GALE WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR ZONE 34. (SEE LAXMWWLOX). WIND ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO 9 PM PST SUNDAY FOR ZONES 53-54-59. (SEE LAXNPWLOX). PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 PM PST MONDAY FOR ZONES 645-670-673-676. (SEE LAXMWWLOX). SMALL CRAFT ADVISORY IN EFFECT FROM 8 AM SUNDAY TO 3 PM PST MONDAY FOR ZONES 650-655. (SEE LAXMWWLOX). && $$ PUBLIC...RORKE AVIATION...HALL MARINE...30 BEACHES...RAT SYNOPSIS...BARTLING WEATHER.GOV/LOSANGELES
  [top] Area Forecast Discussion National Weather Service Sacramento CA 218 PM PST SAT MAR 5 2016 .SYNOPSIS... A strong storm system will move through the area through this evening with heavy rain, strong winds, and localized flooding. Additional rain, along with heavy snow in the mountains, is on tap for Sunday, Monday, and late next week. && .DISCUSSION... Main event is underway with increasing wind and precipitation across the area. One large area of showers has moved out of the valley into the foothills and northern Sierra, but another area of showers presently enhancing to the southwest of the Bay Area will move into the southern Sacramento and northern San Joaquin Valleys late this afternoon. Satellite imagery shows the cold front is now inside of 130W, and with its current movement, it will move across interior NorCal by mid to late evening accompanied by very heavy rain and perhaps a little thunder. Strong ascent and wide swath of deep TPW (in excess of 1.25 inches) ahead of the front result in extreme water vapor transport anomalies this evening (> 7 SD on NAEFS mean IVT!), so heavy rain nearly certain. Will continue flash flood watches for the burn scars and monitor for possible issuance of flood advisories this evening as heavier rain develops. Winds have continued to increase this afternoon. The Fresno to Medford gradient is now around 15 mbs, and the HRRR forecasts it to increase to around 19-20 mbs by 02Z as a 992 mb surface low moves across Siskiyou County. High-res models continue to point toward the potential for a high impact wind event early this evening across the Sacramento Valley and extending eastward into the foothills with 925 mb winds forecast to reach nearly 70 kts ahead of the cold front. Power outages and tree damage will be likely. Snow will develop across the northern Sierra passes late tonight and continue into Monday. Still looking like good potential for several feet of snow along the crest through Monday with a foot or two possible as low as 5000 feet. Main snow impacts will hold off until midnight as profilers indicate the snow level is still above 7500 feet. Snow levels will rapidly lower behind the cold frontal passage late tonight. Heavier precipitation tapers by 12Z Sunday, then picks up again later Sunday into Monday as the next wave moves into the area. Break in the weather looks more likely for Tuesday. && .EXTENDED DISCUSSION (Wednesday THROUGH Saturday) Upper ridging over the area Wednesday shifts east allowing some overrunning precip. GFS keeps this precip mainly north of the forecast area while the EC spreads it over most of the CWA. Forecast is a blend of these Wednesday. Models in better agreement Thursday into Friday and advertise another atmospheric river dropping slowly south through Interior NorCal. QPF values look to be significant during this period. By Saturday, forecast confidence lowers as EC returns upper ridging and drier weather, while the GFS keeps moist cyclonic flow and showers, along with strong wind, especially in orographically favored mountains. && && .AVIATION... Frontal system will impact NorCal this evening into Sunday morning. Expect widespread MVFR/IFR conditions during frontal passage with local LIFR over mountains. Strong southwest winds aloft with strong southerly winds in the valley. Wind gusts ranging 30 to 50 kts...locally higher over ridgetops through at least 06z. Airport Weather Warnings issued for KRDD and KSCK for this evening. JBB && .STO Watches/Warnings/Advisories... Winter Storm Warning until 4 PM PST Monday for West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. Flash Flood Watch through late tonight for Clear Lake/Southern Lake County-Motherlode-West Slope Northern Sierra Nevada. Wind Advisory until 10 PM PST this evening for Burney Basin / Eastern Shasta County-Carquinez Strait and Delta-Central Sacramento Valley-Clear Lake/Southern Lake County-Motherlode- Mountains Southwestern Shasta County to Northern Lake County- Northeast Foothills/Sacramento Valley-Northern Sacramento Valley- Northern San Joaquin Valley-Shasta Lake Area / Northern Shasta County-Southern Sacramento Valley. High Wind Warning until 10 PM PST this evening for Central Sacramento Valley-Motherlode-Northeast Foothills/Sacramento Valley-Northern Sacramento Valley-Southern Sacramento Valley. && $$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
949 AM PST SAT MAR 5 2016 ...HEAVY RAIN LATER THIS AFTERNOON AND EVENING... ...MODERATE RAIN EVENT SUNDAY NIGHT WITH NEXT FRONT... .SYNOPSIS...PERIODS OF RAIN...MAINLY LIGHT THIS MORNING. RAIN WILL THEN INCREASE AND BECOME MODERATE TO HEAVY AFTER 2 PM AS A STRONG COLD FRONT APPROACHES THE BAY AREA. PERIODS OF HEAVY RAIN THIS EVENING WITH GUSTY SOUTHERLY WINDS. WIND AND RAIN WILL RAPIDLY WIND DOWN BEFORE MIDNIGHT. SHOWERS AND ISOLATED THUNDERSTORMS SUNDAY IN POST FRONTAL ENVIRONMENT. NEXT FRONT ARRIVES SUNDAY NIGHT WITH ANOTHER ROUND OF MODERATE RAINS. SHOWERS LINGER MONDAY THEN DRY THROUGH MIDWEEK. CHANCE OF NORTH BAY RAIN BY WEDNESDAY THEN ALL OF THE BAY AREA AND CENTRAL COAST BY THURSDAY AND FRIDAY. && .DISCUSSION...AS OF 9:00 AM PST SATURDAY...RAIN CONTINUES ACROSS OUR REGION WITH MANY LOCATIONS BETWEEN 1 AND 3 TENTHS OVER THE PAST THREE HOURS. KMUX RADAR SHOWS MORE RAIN ON THE WAY ALTHOUGH LOOKS LIKE A DEFINITE BREAK CAN BE EXPECTED LATE THIS MORNING (WHICH THE HRRR ALSO INDICATES). RAIN WILL QUICKLY RETURN THIS AFTERNOON BECOMING MODERATE TO HEAVY AT TIMES AS A STRONG COLD FRONT ADVANCES TO OUR REGION. WPC NOW HAS MOST OF OUR AREA IN THE SLIGHT CHANCE FOR EXCESSIVE RAINFALL AND WITH GUIDANCE STILL SHOWING HEAVY RAIN LATER, DECIDED TO ISSUE A FLASH FLOOD WATCH FOR OUR ENTIRE AREA. ALSO ISSUED AN UPDATE TO THE QPF GRIDS BASED OFF LATEST RFC VALUES, HOWEVER AMOUNTS ARE ONLY SLIGHTLY DIFFERENT COMPARED TO THE PREVIOUS FORECAST PACKAGE. WINDS STILL ON TRACK SO WILL KEEP THE WIND ADVISORY AS IS. BOTTOM LINE...PEOPLE THROUGHOUT THE SAN FRANCISCO AND MONTEREY BAY REGION SHOULD MAKE PREPARATIONS NOW BEFORE THE STORM HITS LATER TODAY. OVERALL FORECAST LOOKS TO BE ON TRACK. .PREVIOUS DISCUSSION...ISSUED A PNS AT 3 AM WITH LATEST 24 HOUR RAINFALL TOTALS. RADAR SHOWS OVERNIGHT STEADY RAINFALL MOVING EASTWARD BUT MORE RETURNS STARTING TO DEVELOP WELL OFFSHORE. WERE STILL IN THE WARM ADVECTION ENVIRONMENT WITH MAINLY LIGHT AND PERIODIC RAINFALL THROUGH LUNCH TIME TODAY. IR SATELLITE OVER THE LAST 6 HOURS OR SO IS SHOWING A BAROCLINIC LEAF CLOUD BLOWING UP OUT NEAR 130W/36N...EVIDENCE OF STRONG INCOMING JET STREAK AND STRENGTHENING SURFACE COLD FRONTAL BOUNDARY. THIS IS THE FEATURE THE MODELS HAVE BEEN HONING IN ON NOW FOR NEARLY THE LAST WEEK. FEATURE WILL QUICKLY APPROACH THE COAST TODAY AND EXPECT MODERATE RAINS TO START IN EARNEST AROUND 2 PM OR SO OVER MUCH OF THE GREATER BAY AREA. LOCAL HILLS SUCH AS BIG SUR AND SANTA CRUZ MOUNTAINS WILL SEE PERIODS OF RAIN THROUGH MOST OF THE DAY. ANYWAY THE HIGHLY ANTICIPATED FRONTAL PASSAGE SHOULD BE OBVIOUS FROM ROUGHLY 3 PM TO 8 PM LOCAL TIME WHEN VERY STRONG WINDS AND HEAVY RAIN OCCUR OVER A SEVERAL HOUR WINDOW OF TIME. DO EXPECT SOME PREFRONTAL SOUTHERLY WIND GUSTS TO SHOW UP AS EARLY AS LUNCH TIME AND CURRENT TIMING OF WIND ADVISORY TO START THEN STILL LOOKS GOOD. SANTA CRUZ MOUNTAINS OFTEN SEE WIND DAMAGE AND LINES DOWN IN THESE TYPE OF PATTERNS AS SYNOPTIC FLOW AND STRONG SOUTHEAST WINDS FLOWING OUT OF SALINAS VALLEY FOCUS UP THERE. ANYWAY THE HRRR AND RAP SHORT TERM MESOSCALE MODELS ARE IN AGREEMENT THAT THE HEAVIEST RAINS FALL FROM ROUGHLY 4 TO 8 PM THIS EVENING (EARLIEST IN THE NORTH BAY AND LATEST IN MONTEREY BAY REGION). STORM TOTALS FROM NOW THROUGH ABOUT 10 PM TONIGHT SHOULD BRING 1-2 INCHES TO THE LOWER ELEVATIONS WITH 2-5 INCHES FOR THE NORTH BAY/SANTA CRUZ AND SANTA LUCIA HILLS. (USUAL DRY SPOTS IN THE SALINAS AND EAST BAY VALLEYS WILL BE UNDER AN INCH). THIS STORM WILL CAUSE ISSUES TONIGHT THROUGHOUT THE BAY AREA WITH TRAFFIC...LOCALIZED FLOODING DUE TO THE HEAVY RAIN RATES OVER A SHORT WINDOW OF TIME AND ASSOCIATED WIND DAMAGE ISSUES. A DISTINCT LULL IN THE ACTION WILL OCCUR AFTER MIDNIGHT BEHIND THE FRONT WITH ONLY SOME LINGERING SHOWERS AND MUCH LIGHTER SW WINDS. SHOWER AND POST FRONTAL T-STORMS POSSIBLE ON SUNDAY BUT PARTLY CLOUDY SKIES WILL PREVAIL FOR MANY AREAS SOUTH OF SAN FRANCISCO ON SUNDAY. NEXT SYSTEM APPROACHING WILL BRING GENTLE WARM ADVECTION RAINS TO THE NORTH BAY BY SUNDAY AFTERNOON. THEN ON SUNDAY NIGHT POTENT SHORTWAVE WITH MUCH COLDER AIR ALOFT WILL PASS FROM NW TO SE ACROSS THE DISTRICT. ANOTHER ROUND OF SOME HEAVY RAIN SHOWERS WITH POSSIBLE T-STORMS WILL OCCUR. RAIN TOTALS WILL BE LESS WITH THIS SYSTEM BUT SOME LOCALIZED HEAVY RAINFALL SHOULD BE EXPECTED. LOOKS LIKE THE BULK OF THE HEAVY RAIN IS DONE BY 12Z MONDAY WITH ONLY SOME LINGERING RAINS SHOWERS BY 15Z MONDAY FOR THE MORNING COMMUTE. HOWEVER EVEN A WET START TO THE COMMUTE IS OFTEN ENOUGH TO THROW THINGS INTO DISARRAY TO START OUT THE WORK WEEK. SIMILAR TO SUNDAY...SHOWERS CHANCES WILL LINGER MONDAY BUT BE ON THE DECREASE THROUGH THE DAY. LOOKS DRY MONDAY NIGHT AND TUESDAY. LATEST ECMWF HAS TRENDED WETTER BY WEDS FOR THE NORTH BAY WITH SOME WARM FRONTAL LIGHT RAIN CHANCES. MORE ORGANIZED COLD FRONT THEN ARRIVES LATER THURSDAY INTO FRIDAY. WILL HONE IN ON THOSE DETAILS AFTER WE GET THROUGH THE WEEKEND SYSTEMS BUT THE STORMS LATER NEXT WEEK LOOK MODERATE IN STRENGTH/INTENSITY. && .AVIATION...AS OF 9:49 AM PST SATURDAY...A STRONG COLD FRONT WILL MOVE ACROSS THE AREA THIS EVENING. DETERIORATING WX CONDITIONS TODAY WITH MODERATE-HEAVY RAIN AND STRONG S-SE WINDS EXPECTED UP TO THE FRONTAL PASSAGE THIS EVENING. SHOWERY COLDER MORE UNSTABLE AIR ARRIVES LATE TONIGHT AND SUNDAY. VICINITY OF KSFO...AIRPORT WEATHER WARNING ISSUED FOR STRONG AND GUSTY S-SE WINDS. MVFR CIGS. RAIN. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS. STRONG AND GUSTY SOUTHERLY WINDS DEVELOPING TODAY. RAIN. && .BEACHES...AS OF 5:30 AM PST SATURDAY...A HIGH SURF ADVISORY BEGINS 10 PM TONIGHT AND LASTS INTO TUESDAY MORNING. WESTERLY SWELL WILL BE PEAKING CLOSE TO 20 FEET WITH 14 SECOND SWELL PERIODS FROM LATE SUNDAY NIGHT TO MONDAY NIGHT. IF FUTURE WAVE MODEL FORECASTS TREND STEADY OR HIGHER WITH THE PEAK OF THIS SWELL TRAIN THEN THE ADVISORY MAY NEED TO BE UPGRADED TO A HIGH SURF WARNING AT A LATER POINT IN TIME. PLEASE STAY TUNED. && .MARINE...AS OF 8:27 AM PST SATURDAY...SOUTHERLY WINDS WILL BECOME STRONG AND GUSTY TODAY AS A COLD FRONT APPROACHES THE AREA. GALE FORCE WINDS ARE EXPECTED OVER THE WATERS THIS AFTERNOON AND TONIGHT. A LARGE WESTERLY SWELL WILL ARRIVE TONIGHT AND PERSIST THROUGH EARLY TUESDAY MORNING. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...WIND ADVISORY...ALL LOCATIONS TODAY AND THIS EVENING FLASH FLOOD WATCH...ALL LOCATIONS TODAY AND THIS EVENING SCA...MRY BAY FROM 10 AM SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 10 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 10 AM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 10 AM GLW...MRY BAY FROM 4 PM GLW...PIGEON PT TO PT PINOS 0-10 NM FROM 4 PM GLW...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 4 PM GLW...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 4 PM SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 10 AM SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 10 AM SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 10 AM GLW...PT ARENA TO PT REYES 0-10 NM FROM 10 AM GLW...PT REYES TO PIGEON PT 0-10 NM FROM 10 AM GLW...PT ARENA TO PIGEON PT 10-60 NM FROM 10 AM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...SF BAY UNTIL NOON GLW...SF BAY FROM NOON && $$ PUBLIC FORECAST: BELL/R_WALBRUN AVIATION: SIMS MARINE: SIMS VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
909 AM PST SAT MAR 5 2016 ...HEAVY RAIN LATER THIS AFTERNOON AND EVENING... ...MODERATE RAIN EVENT SUNDAY NIGHT WITH NEXT FRONT... .SYNOPSIS...PERIODS OF RAIN...MAINLY LIGHT THIS MORNING. RAIN WILL THEN INCREASE AND BECOME MODERATE TO HEAVY AFTER 2 PM AS A STRONG COLD FRONT APPROACHES THE BAY AREA. PERIODS OF HEAVY RAIN THIS EVENING WITH GUSTY SOUTHERLY WINDS. WIND AND RAIN WILL RAPIDLY WIND DOWN BEFORE MIDNIGHT. SHOWERS AND ISOLATED THUNDERSTORMS SUNDAY IN POST FRONTAL ENVIRONMENT. NEXT FRONT ARRIVES SUNDAY NIGHT WITH ANOTHER ROUND OF MODERATE RAINS. SHOWERS LINGER MONDAY THEN DRY THROUGH MIDWEEK. CHANCE OF NORTH BAY RAIN BY WEDNESDAY THEN ALL OF THE BAY AREA AND CENTRAL COAST BY THURSDAY AND FRIDAY. && .DISCUSSION...AS OF 9:00 AM PST SATURDAY...RAIN CONTINUES ACROSS OUR REGION WITH MANY LOCATIONS BETWEEN 1 AND 3 TENTHS OVER THE PAST THREE HOURS. KMUX RADAR SHOWS MORE RAIN ON THE WAY ALTHOUGH LOOKS LIKE A DEFINITE BREAK CAN BE EXPECTED LATE THIS MORNING (WHICH THE HRRR ALSO INDICATES). RAIN WILL QUICKLY RETURN THIS AFTERNOON BECOMING MODERATE TO HEAVY AT TIMES AS A STRONG COLD FRONT ADVANCES TO OUR REGION. WPC NOW HAS MOST OF OUR AREA IN THE SLIGHT CHANCE FOR EXCESSIVE RAINFALL AND WITH GUIDANCE STILL SHOWING HEAVY RAIN LATER, DECIDED TO ISSUE A FLASH FLOOD WATCH FOR OUR ENTIRE AREA. ALSO ISSUED AN UPDATE TO THE QPF GRIDS BASED OFF LATEST RFC VALUES, HOWEVER AMOUNTS ARE ONLY SLIGHTLY DIFFERENT COMPARED TO THE PREVIOUS FORECAST PACKAGE. WINDS STILL ON TRACK SO WILL KEEP THE WIND ADVISORY AS IS. BOTTOM LINE...PEOPLE THROUGHOUT THE SAN FRANCISCO AND MONTEREY BAY REGION SHOULD MAKE PREPARATIONS NOW BEFORE THE STORM HITS LATER TODAY. OVERALL FORECAST LOOKS TO BE ON TRACK. .PREVIOUS DISCUSSION...ISSUED A PNS AT 3 AM WITH LATEST 24 HOUR RAINFALL TOTALS. RADAR SHOWS OVERNIGHT STEADY RAINFALL MOVING EASTWARD BUT MORE RETURNS STARTING TO DEVELOP WELL OFFSHORE. WERE STILL IN THE WARM ADVECTION ENVIRONMENT WITH MAINLY LIGHT AND PERIODIC RAINFALL THROUGH LUNCH TIME TODAY. IR SATELLITE OVER THE LAST 6 HOURS OR SO IS SHOWING A BAROCLINIC LEAF CLOUD BLOWING UP OUT NEAR 130W/36N...EVIDENCE OF STRONG INCOMING JET STREAK AND STRENGTHENING SURFACE COLD FRONTAL BOUNDARY. THIS IS THE FEATURE THE MODELS HAVE BEEN HONING IN ON NOW FOR NEARLY THE LAST WEEK. FEATURE WILL QUICKLY APPROACH THE COAST TODAY AND EXPECT MODERATE RAINS TO START IN EARNEST AROUND 2 PM OR SO OVER MUCH OF THE GREATER BAY AREA. LOCAL HILLS SUCH AS BIG SUR AND SANTA CRUZ MOUNTAINS WILL SEE PERIODS OF RAIN THROUGH MOST OF THE DAY. ANYWAY THE HIGHLY ANTICIPATED FRONTAL PASSAGE SHOULD BE OBVIOUS FROM ROUGHLY 3 PM TO 8 PM LOCAL TIME WHEN VERY STRONG WINDS AND HEAVY RAIN OCCUR OVER A SEVERAL HOUR WINDOW OF TIME. DO EXPECT SOME PREFRONTAL SOUTHERLY WIND GUSTS TO SHOW UP AS EARLY AS LUNCH TIME AND CURRENT TIMING OF WIND ADVISORY TO START THEN STILL LOOKS GOOD. SANTA CRUZ MOUNTAINS OFTEN SEE WIND DAMAGE AND LINES DOWN IN THESE TYPE OF PATTERNS AS SYNOPTIC FLOW AND STRONG SOUTHEAST WINDS FLOWING OUT OF SALINAS VALLEY FOCUS UP THERE. ANYWAY THE HRRR AND RAP SHORT TERM MESOSCALE MODELS ARE IN AGREEMENT THAT THE HEAVIEST RAINS FALL FROM ROUGHLY 4 TO 8 PM THIS EVENING (EARLIEST IN THE NORTH BAY AND LATEST IN MONTEREY BAY REGION). STORM TOTALS FROM NOW THROUGH ABOUT 10 PM TONIGHT SHOULD BRING 1-2 INCHES TO THE LOWER ELEVATIONS WITH 2-5 INCHES FOR THE NORTH BAY/SANTA CRUZ AND SANTA LUCIA HILLS. (USUAL DRY SPOTS IN THE SALINAS AND EAST BAY VALLEYS WILL BE UNDER AN INCH). THIS STORM WILL CAUSE ISSUES TONIGHT THROUGHOUT THE BAY AREA WITH TRAFFIC...LOCALIZED FLOODING DUE TO THE HEAVY RAIN RATES OVER A SHORT WINDOW OF TIME AND ASSOCIATED WIND DAMAGE ISSUES. A DISTINCT LULL IN THE ACTION WILL OCCUR AFTER MIDNIGHT BEHIND THE FRONT WITH ONLY SOME LINGERING SHOWERS AND MUCH LIGHTER SW WINDS. SHOWER AND POST FRONTAL T-STORMS POSSIBLE ON SUNDAY BUT PARTLY CLOUDY SKIES WILL PREVAIL FOR MANY AREAS SOUTH OF SAN FRANCISCO ON SUNDAY. NEXT SYSTEM APPROACHING WILL BRING GENTLE WARM ADVECTION RAINS TO THE NORTH BAY BY SUNDAY AFTERNOON. THEN ON SUNDAY NIGHT POTENT SHORTWAVE WITH MUCH COLDER AIR ALOFT WILL PASS FROM NW TO SE ACROSS THE DISTRICT. ANOTHER ROUND OF SOME HEAVY RAIN SHOWERS WITH POSSIBLE T-STORMS WILL OCCUR. RAIN TOTALS WILL BE LESS WITH THIS SYSTEM BUT SOME LOCALIZED HEAVY RAINFALL SHOULD BE EXPECTED. LOOKS LIKE THE BULK OF THE HEAVY RAIN IS DONE BY 12Z MONDAY WITH ONLY SOME LINGERING RAINS SHOWERS BY 15Z MONDAY FOR THE MORNING COMMUTE. HOWEVER EVEN A WET START TO THE COMMUTE IS OFTEN ENOUGH TO THROW THINGS INTO DISARRAY TO START OUT THE WORK WEEK. SIMILAR TO SUNDAY...SHOWERS CHANCES WILL LINGER MONDAY BUT BE ON THE DECREASE THROUGH THE DAY. LOOKS DRY MONDAY NIGHT AND TUESDAY. LATEST ECMWF HAS TRENDED WETTER BY WEDS FOR THE NORTH BAY WITH SOME WARM FRONTAL LIGHT RAIN CHANCES. MORE ORGANIZED COLD FRONT THEN ARRIVES LATER THURSDAY INTO FRIDAY. WILL HONE IN ON THOSE DETAILS AFTER WE GET THROUGH THE WEEKEND SYSTEMS BUT THE STORMS LATER NEXT WEEK LOOK MODERATE IN STRENGTH/INTENSITY. && .AVIATION...AS OF 5:44 AM PST SATURDAY...A STRONG COLD FRONT WILL SWEEP EAST OVER THE AREA THIS EVENING. THIS FRONTAL PASSAGE HAS THE POTENTIAL TO BE THE STRONGEST WE`VE SEEN THIS WINTER SEASON. DETERIORATING WX CONDITIONS TODAY WITH MODERATE-HEAVY RAIN AND HEAVY S-SE WIND COMBINED UP TO THE FRONTAL PASSAGE THIS EVENING. WORTH NOTING PRE-FRONTAL S-SE WINDS OFTEN CAUSES A RAIN SHADOW FOR PLACES LIKE THE SOUTH BAY AND THE MONTEREY PENINSULA THUS THE RAIN MAY AT TIMES BECOME MORE PERIODIC TODAY IN PLACES THAT ARE IN THE LEE OF HIGHER TERRAIN. SHOWERY COLDER MORE UNSTABLE AIR ARRIVES LATE TONIGHT AND SUNDAY. VICINITY OF KSFO...AIRPORT WEATHER WARNING ISSUED FOR STRONG AND GUSTY S-SE WINDS. MVFR CIGS. RAIN. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS. STRONG AND GUSTY SOUTHERLY WINDS DEVELOPING TODAY. RAIN. && .BEACHES...AS OF 5:30 AM PST SATURDAY...A HIGH SURF ADVISORY BEGINS 10 PM TONIGHT AND LASTS INTO TUESDAY MORNING. WESTERLY SWELL WILL BE PEAKING CLOSE TO 20 FEET WITH 14 SECOND SWELL PERIODS FROM LATE SUNDAY NIGHT TO MONDAY NIGHT. IF FUTURE WAVE MODEL FORECASTS TREND STEADY OR HIGHER WITH THE PEAK OF THIS SWELL TRAIN THEN THE ADVISORY MAY NEED TO BE UPGRADED TO A HIGH SURF WARNING AT A LATER POINT IN TIME. PLEASE STAY TUNED. && .MARINE...AS OF 08:53 AM PST SATURDAY...SOUTHERLY WINDS WILL BECOME STRONG AND GUSTY TODAY AS A COLD FRONT APPROACHES THE AREA. GALE FORCE WINDS ARE EXPECTED OVER THE WATERS THIS AFTERNOON AND TONIGHT. A LARGE WESTERLY SWELL WILL ARRIVE TONIGHT AND PERSIST THROUGH EARLY TUESDAY MORNING. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...WIND ADVISORY...ALL LOCATIONS TODAY AND THIS EVENING FLASH FLOOD WATCH...ALL LOCATIONS TODAY AND THIS EVENING SCA...MRY BAY FROM 10 AM SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 10 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 10 AM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 10 AM GLW...MRY BAY FROM 4 PM GLW...PIGEON PT TO PT PINOS 0-10 NM FROM 4 PM GLW...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 4 PM GLW...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 4 PM SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 10 AM SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 10 AM SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 10 AM GLW...PT ARENA TO PT REYES 0-10 NM FROM 10 AM GLW...PT REYES TO PIGEON PT 0-10 NM FROM 10 AM GLW...PT ARENA TO PIGEON PT 10-60 NM FROM 10 AM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...SF BAY UNTIL NOON GLW...SF BAY FROM NOON && $$ PUBLIC FORECAST: BELL/R_WALBRUN AVIATION: CANEPA MARINE: SIMS VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
259 PM CST SAT MAR 5 2016 .SHORT TERM...(Tonight) ISSUED AT 259 PM CST SAT MAR 5 2016 Despite passage of a short-wave trough and its associated cold front, clouds continue to blanket central Illinois this afternoon. In fact, 20z/2pm visible satellite imagery shows continuous cloud cover upstream into Wisconsin and the eastern half of Iowa as well. Based on the trajectory of the clouds, the KILX CWA will remain on the southwest periphery of the cloud shield through at least early evening. HRRR has been consistently showing the clouds partially dissipating from the W/SW toward sunset, resulting in mostly clear skies across much of the area by mid to late evening. Think this may be a bit too aggressive with the clearing, so have slowed trends from previous forecasts. Have started the evening with mostly cloudy skies everywhere except across the far southwest around Jacksonville where partly to mostly clear conditions will prevail. As per the latest HRRR, have then cleared things out from west to east through the evening, but have maintained mostly cloudy skies northeast of I-74 until well after midnight. Due to the clearing skies and diminishing winds, have undercut MAV guidance numbers by a couple of degrees, with frosty overnight lows in the middle to upper 20s. && .LONG TERM...(Sunday through Saturday) ISSUED AT 259 PM CST SAT MAR 5 2016 Mild temperatures and wet weather will be the primary features for much of the upcoming forecast period through next Saturday. For Sunday, brisk southerly winds around 15 mph and gusts around 25 mph will set up by afternoon west of I-57 as a corridor of strong moist southwesterly flow sets up over the Plains. This will initiate showers and a few thunderstorms, potentially creeping eastward into west-central IL Sunday night. Highs should reach the mid 50s to around 60 degrees in Springfield and Jacksonville. Mild lows in the mid 40s expected Sunday night as precipitable water around 1 inch, or approaching 99th percentile for this time of year, plumes over central IL. On Monday, southerly winds expected to increase to 15-20 mph and gust to 25-30 mph. High temperatures should reach the mid 60s as warm advection continues, and rich precipitable water continues to stream over Illinois. Still, weak forcing appears it will result in modest precipitation chances and amounts, mainly I-72 northward. The moisture plume looks to remain in the vicinity through midweek as a frontal boundary lingers just to the northwest, and a series of disturbances track along the front bringing periods of heavier rain. Some uncertainty remain in the location of the front through midweek and this will modulate the exact timing and location of precipitation through midweek, however likely to categorical (80%+) chance of precipitation included in the forecast for Tuesday night through Wednesday night, and current precipitation amounts 2-2.5 inches I-72 southward expected through this period, with 0.5 to 2.0 inches to the north. Instability pattern indicates occasional thunderstorms a possibility. A hydrologic outlook remains in effect to address the heavy rain concern during this period. Highs through midweek expected to remain mild, from around 60 to 65 degrees. Next weekend...a cut-off low that should be meanering over Mexico midweek is progged to eject northeast toward central IL. Unfortunately, the timing and track of this feature is highly uncertain as evidenced by a variety of differing model and ensemble solutions available at this time. This feature will have impacts on the position of the frontal boundary, temperatures, and precipitation for central IL. With the front position still a significant question, PoP`s generally remain in place over most of the forecast area into Saturday. High temperatures forecast from around 60 to 65, but this will be subject to change. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) ISSUED AT 1134 AM CST SAT MAR 5 2016 MVFR ceilings continue to spill southward into central Illinois behind a departing cold front late this morning. While visible satellite imagery shows plenty of clouds upstream across Iowa/Wisconsin, there are also a few holes developing in the overcast. HRRR has consistently suggested the cloud deck would begin to erode this afternoon, with any appreciable clearing holding off until evening. 12z NAM forecast soundings support this as well, with skies clearing at KSPI around 00z...then further northeast to KCMI by 03z. Skies will then remain mostly clear through the night before WAA on the back side of retreating high pressure brings increasing mid-level clouds Sunday morning. NAM shows rapidly increasing moisture within the 12000 to 15000ft layer across the western half of the area after 14z, so have included a broken mid deck at all sites except KDEC and KCMI. Winds will initially be strong/gusty from the northwest this afternoon, then will become light/variable tonight as high pressure drifts overhead. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Barnes LONG TERM...Onton AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1134 AM CST SAT MAR 5 2016 .UPDATE... ISSUED AT 1035 AM CST SAT MAR 5 2016 Weak cold front is currently passing through central Illinois, with 16z/10am obs showing it approaching the Indiana border. No precip is occurring with the front: however, quite a bit of low cloud cover is spilling southward in its wake. Latest satellite imagery shows ample clouds upstream across Iowa, Wisconsin, and Minnesota. Based on trajectory of clouds, central Illinois will remain on the S/SW edge of the cloud shield today. Most high-res guidance is suggesting the clouds will begin to erode this afternoon, resulting in partial clearing across the S/SW KILX CWA. Elsewhere around the area, skies will remain mostly cloudy throughout the day. Northwesterly winds will gust to between 20 and 30mph behind the front, while afternoon high temperatures reach the middle to upper 40s across much of the area. The exception will be south of I-70 around Flora and Olney where additional sunshine will boost highs into the lower 50s. && .SHORT TERM...(Today) ISSUED AT 241 AM CST SAT MAR 5 2016 Patchy fog will affect central Illinois ahead of an advancing cold front early this morning. The fog will clear by mid-morning as cold front departs into Indiana by 11 am. Little to no precipitation is expected with the frontal passage in central Illinois, except for possibly a few sprinkles in areas northeast of Champaign to Danville. Winds will shift from southwest to northwest behind the front, and become breezy with gusts to 25 mph at times later this morning and this afternoon. The latest HRRR and RAP guidance are pointing towards enough residual low level moisture behind the front for mostly cloudy skies to linger through at least mid-afternoon. Breaks will eventually develop in the cloud layer due to turbulent mixing of dry mid-level air toward the surface. Areas southwest of Springfield to Mattoon will have the best chances of seeing sunshine earlier, but even northeast areas should see sunshine break through later this afternoon. Even limited late afternoon sunshine should help high temperatures reach the mid 40s north of I-74, with lower 50s for areas from Jacksonville to Effingham to Lawrenceville. .LONG TERM...(Tonight through Friday) ISSUED AT 241 AM CST SAT MAR 5 2016 Mild and wet period shaping up for much of the upcoming week, as upper flow finally trends more toward the southwest. Main issue will be with the rains, as a frontal boundary will be draped over the state part of the time, and will limit some of the rainfall north of it around midweek. High pressure will quickly pass through the Midwest tonight, and southerly winds will be in place by Sunday morning and become a bit gusty. This will bring temperatures well into the 50s, with some 60 degree readings possible over the southwest CWA. Some WAA-type precip expected to develop by afternoon west of the Illinois border, but forecast soundings in our area quite parched below 700 mb until evening, and thus will keep the daytime hours dry albeit with increasing clouds. Have limited mentionable PoP`s Sunday night to west of I-55, with most of the energy tracking into northwest Illinois. On Monday, southerly winds expected to gust from 25-30 mph, pushing temperatures well into the 60s. During this time, an upper trough will be digging southward along the California coast, closing off a low over the Baja. Nice moisture surge coming northward from the Gulf of Mexico will combine with a wave/front in the northern stream to gradually increase rain chances from west to east across the state. Reasonable agreement among the models through about Tuesday evening with the cold front being just to our northwest. Waves of low pressure will surge northeast along the front bringing periods of heavier rain, but how far south the front makes it first will be key. The ECMWF is slowest in exiting the rain (not until Thursday evening over the southeast CWA), while the GFS and Canadian show periodic surges of rain until Thursday morning. Went with categorical PoP`s (80%) for most areas east of I-55 Tuesday night through Wednesday night. WPC progs and blended model guidance suggesting potential for 3-4 inches of rain through the week in this area, subject to the oscillations of the front. Hydrologic Outlook product is being used to address this heavy rain concern for the time being. The upper low will only slowly drift through northern Mexico, cut off from the northern flow through much of the week. Late in the period, the GFS and ECMWF show this low finally ejecting northeast, although the GFS is much faster in bringing the frontal boundary back north. With the front position still a significant question, PoP`s generally remain in place over most of the forecast area into Friday. Temperatures north of the front will cool a bit mid week, but still be mid-upper 50s for highs. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) ISSUED AT 1134 AM CST SAT MAR 5 2016 MVFR ceilings continue to spill southward into central Illinois behind a departing cold front late this morning. While visible satellite imagery shows plenty of clouds upstream across Iowa/Wisconsin, there are also a few holes developing in the overcast. HRRR has consistently suggested the cloud deck would begin to erode this afternoon, with any appreciable clearing holding off until evening. 12z NAM forecast soundings support this as well, with skies clearing at KSPI around 00z...then further northeast to KCMI by 03z. Skies will then remain mostly clear through the night before WAA on the back side of retreating high pressure brings increasing mid-level clouds Sunday morning. NAM shows rapidly increasing moisture within the 12000 to 15000ft layer across the western half of the area after 14z, so have included a broken mid deck at all sites except KDEC and KCMI. Winds will initially be strong/gusty from the northwest this afternoon, then will become light/variable tonight as high pressure drifts overhead. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Barnes SHORT TERM...Shimon LONG TERM...Geelhart AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1035 AM CST SAT MAR 5 2016 .UPDATE... ISSUED AT 1035 AM CST SAT MAR 5 2016 Weak cold front is currently passing through central Illinois, with 16z/10am obs showing it approaching the Indiana border. No precip is occurring with the front: however, quite a bit of low cloud cover is spilling southward in its wake. Latest satellite imagery shows ample clouds upstream across Iowa, Wisconsin, and Minnesota. Based on trajectory of clouds, central Illinois will remain on the S/SW edge of the cloud shield today. Most high-res guidance is suggesting the clouds will begin to erode this afternoon, resutling in partial clearing across the S/SW KILX CWA. Elsewhere around the area, skies will remain mostly cloudy throughout the day. Northwesterly winds will gust to between 20 and 30mph behind the front, while afternoon high temperatures reach the middle to upper 40s across much of the area. The exception will be south of I-70 around Flora and Olney where additional sunshine will boost highs into the lower 50s. && .SHORT TERM...(Today) ISSUED AT 241 AM CST SAT MAR 5 2016 Patchy fog will affect central Illinois ahead of an advancing cold front early this morning. The fog will clear by mid-morning as cold front departs into Indiana by 11 am. Little to no precipitation is expected with the frontal passage in central Illinois, except for possibly a few sprinkles in areas northeast of Champaign to Danville. Winds will shift from southwest to northwest behind the front, and become breezy with gusts to 25 mph at times later this morning and this afternoon. The latest HRRR and RAP guidance are pointing towards enough residual low level moisture behind the front for mostly cloudy skies to linger through at least mid-afternoon. Breaks will eventually develop in the cloud layer due to turbulent mixing of dry mid-level air toward the surface. Areas southwest of Springfield to Mattoon will have the best chances of seeing sunshine earlier, but even northeast areas should see sunshine break through later this afternoon. Even limited late afternoon sunshine should help high temperatures reach the mid 40s north of I-74, with lower 50s for areas from Jacksonville to Effingham to Lawrenceville. .LONG TERM...(Tonight through Friday) ISSUED AT 241 AM CST SAT MAR 5 2016 Mild and wet period shaping up for much of the upcoming week, as upper flow finally trends more toward the southwest. Main issue will be with the rains, as a frontal boundary will be draped over the state part of the time, and will limit some of the rainfall north of it around midweek. High pressure will quickly pass through the Midwest tonight, and southerly winds will be in place by Sunday morning and become a bit gusty. This will bring temperatures well into the 50s, with some 60 degree readings possible over the southwest CWA. Some WAA-type precip expected to develop by afternoon west of the Illinois border, but forecast soundings in our area quite parched below 700 mb until evening, and thus will keep the daytime hours dry albeit with increasing clouds. Have limited mentionable PoP`s Sunday night to west of I-55, with most of the energy tracking into northwest Illinois. On Monday, southerly winds expected to gust from 25-30 mph, pushing temperatures well into the 60s. During this time, an upper trough will be digging southward along the California coast, closing off a low over the Baja. Nice moisture surge coming northward from the Gulf of Mexico will combine with a wave/front in the northern stream to gradually increase rain chances from west to east across the state. Reasonable agreement among the models through about Tuesday evening with the cold front being just to our northwest. Waves of low pressure will surge northeast along the front bringing periods of heavier rain, but how far south the front makes it first will be key. The ECMWF is slowest in exiting the rain (not until Thursday evening over the southeast CWA), while the GFS and Canadian show periodic surges of rain until Thursday morning. Went with categorical PoP`s (80%) for most areas east of I-55 Tuesday night through Wednesday night. WPC progs and blended model guidance suggesting potential for 3-4 inches of rain through the week in this area, subject to the oscillations of the front. Hydrologic Outlook product is being used to address this heavy rain concern for the time being. The upper low will only slowly drift through northern Mexico, cut off from the northern flow through much of the week. Late in the period, the GFS and ECMWF show this low finally ejecting northeast, although the GFS is much faster in bringing the frontal boundary back north. With the front position still a significant question, PoP`s generally remain in place over most of the forecast area into Friday. Temperatures north of the front will cool a bit mid week, but still be mid-upper 50s for highs. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) ISSUED AT 600 AM CST SAT MAR 5 2016 A cold front, currently passing on a line from Galesburg to Quincy, will continue to track east across our area this morning. Forecast soundings and last few runs of the HRRR model correctly depicted the IFR/LIFR ceilings in over our eastern terminals of CMI, BMI, and DEC. PIA also dropped down to VLIFR vis and IFR cig. Conditions will improve to VFR at all the terminal sites as the cold front passes between 13z and 16z. Satellite images show a region of high MVFR and VFR clouds rotating into NW IL. They are poised to affect all of our terminal sites later this morning and early this afternoon, with less coverage for the southern TAF sites of SPI and DEC. Turbulent mixing of dry mid level air should help to create breaks in cloud cover as the afternoon progresses. The winds are the other issue today, with southwest winds becoming light as the cold front passes, then increasing out of the northwest shortly after FROPA. Sustained winds will become 12-16kt with gusts to 23kt at times late this morning and early this afternoon. Pressure rises will weaken later this afternoon, with gusts diminishing by sunset. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Barnes SHORT TERM...Shimon LONG TERM...Geelhart AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS JACKSON KY
302 PM EST SAT MAR 5 2016 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 220 PM EST SAT MAR 5 2016 18Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING SOUTH THROUGH EASTERN KENTUCKY ON ITS TREK TO THE SOUTHEAST COAST. THIS IS PUSHING A FAIRLY LARGE BAND OF SCATTERED TO NUMEROUS SHOWERS THROUGH THE CWA WITH GENERALLY A TENTH TO TWO TENTHS OF AN INCH OF RAIN EXPECTED. EARLIER...THIS LOW HELPED TO BREAK UP THE LOW CLOUDS AND FOG RELEASING THE AREA FROM CHILLY TEMPERATURES IN THE LOWER AND MIDDLE 30S. CURRENTLY...READINGS HAVE MADE IT INTO THE LOW 40S NORTH AND THE LOWER 50S SOUTH ON SOUTH TO SOUTHWEST WINDS. DEWPOINTS...MEANWHILE...HAVE ALSO CLIMBED WITH THE UPPER 30S AND 40S MOST COMMON AS THE RAIN STARTS TO MOVE IN. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST AS A COMPACT WAVE STRENGTHENS AND MOVES THROUGH THE SOUTHERN APPALACHIANS...TO THE SOUTHEAST COAST LATER TODAY AND INTO TONIGHT. THIS SHARP LITTLE FEATURE WILL BE FOLLOWED BY AN EQUALLY DISTINCT RIDGE BUILDING INTO KENTUCKY FROM THE SOUTHERN PLAINS. THIS RIDGE PLANTS ITSELF FIRMLY OVER THE AREA ON SUNDAY...BUILDING INTO MONDAY AS IT STARTS TO BE PUMPED UP DUE TO ITS POSITION DOWNSTREAM OF A LARGE DIGGING WEST COAST TROUGH. LOOK FOR THE RIDGE TO KEEP ANY MID LEVEL WAVES OF ENERGY TO THE NORTH OF THE AREA KEEPING THE WX QUIET. GIVEN THE MODEL AGREEMENT AND MAINLY JUST NEAR TERM WEATHER CONCERNS...HAVE FAVORED A GENERAL MODEL BLEND WITH STRONG LEAN TOWARD THE HRRR AND NAM12 SOLUTIONS. SENSIBLE WEATHER WILL FEATURE A RELATIVELY WEAK LOW PRESSURE SFC WAVE PASSING THROUGH EAST KENTUCKY WITH BULK OF THE SHOWERS MOVING THROUGH THIS AFTERNOON AND GRADUALLY DIMINISHING INTO THE EVENING FROM NORTHWEST TO SOUTHEAST. COOLER AIR DOES FOLLOW THIS LOW BUT NOT ENOUGH TO WORRY ABOUT ANY SNOW MIXING IN BEFORE THE LAST OF THE PCPN DEPARTS. OF A LARGER CONCERN WILL BE THE POTENTIAL FOR FOG DEVELOPING AGAIN TONIGHT. GIVEN THE AMPLE LOW LEVEL MOISTURE LEFT BEHIND AROUND AND ANTICIPATED SUBSIDENCE INVERSION HAVE HIT THE FOG RATHER HARD IN THE GRIDS WITH SOME AREAS HAVING SOME DENSE FOG. RIDGES MAY SEE LOW VISIBILITIES...AS WELL...WITH THE LOW CLOUDS SETTLING IN AFTER MIDNIGHT. THIS WILL ALL CLEAR OUT FAIRLY QUICKLY ON SUNDAY...THOUGH...WITH SUNSHINE RETURNING AND SOUTHERLY WINDS HELPING TO BRING TEMPS BACK INTO THE LOWER AND MIDDLE 50S BY AFTERNOON...FOR MOST PLACES. HIGH PRESSURE MOVING OFF TO THE EAST WILL LIKELY SET THE STAGE FOR A DECENT RIDGE TO VALLEY TEMPERATURE SPLIT SUNDAY NIGHT INTO MONDAY MORNING UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. ALSO...WOULD ANTICIPATE SOME VALLEY FOG DEVELOPING LATE SUNDAY NIGHT THROUGH DAWN MONDAY. USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THE NIGHT BEFORE FAVORING THE SUPERBLEND THEREAFTER. MADE THE MOST SIGNIFICANT CHANGES TO THE T GRIDS ON SUNDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE AND VALLEY DISTINCTIONS. AS FOR POP...ENDED UP CLOSEST TO THE HIGHER MET VALUES INTO THE EVENING BEFORE NEARLY ZEROING THEM OUT THROUGH MONDAY MORNING...IN LINE WITH GUIDANCE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 302 PM EST SAT MAR 5 2016 THE FIRST FEW DAYS OF THE EXTENDED ARE EXPECTED TO BE WARM AND DRY...AS A LARGE RIDGE OF HIGH PRESSURE STUBBORNLY REMAINS IN PLACE ACROSS THE SOUTHEASTERN CONUS. A WEAK COLD FRONT IS FORECAST TO MOVE OUT OF THE PLAINS TO START THE PERIOD...BUT WILL HAVE A DIFFICULT TIME MAKING MUCH EASTWARD PROGRESS AT FIRST AS IT ENCOUNTERS THE AFOREMENTIONED RIDGE. THE CURRENT DATA SUGGESTS THAT THE FRONT WILL FINALLY BEGIN TO MOVE EASTWARD LATE IN THE DAY WEDNESDAY...AS ITS PARENT UPPER LEVEL TROUGH MOVES EASTWARD ALONG THE NORTHERN THIRD OF THE CONUS. WHAT WILL MOST LIKELY HAPPEN IS THE NORTHERN SECTION OF THE FRONT WILL MOVE EAST WITH THE UPPER TROUGH...AS THE SOUTHERN HALF OF THE BOUNDARY GETS HUNG UP ALONG THE WESTERN EDGE OF THE RIDGE. AS THE RIDGE FINALLY BEGINS TO BREAK DOWN WEDNESDAY NIGHT...THE WEAKENING COLD FRONT SHOULD BE ABLE TO DRIFT SOUTHWARD ACROSS THE OHIO VALLEY AND BECOME NEARLY STATIONARY ACROSS THE REGION FROM THURSDAY ONWARD. THERE WILL BE A CHANCE OF THUNDERSTORMS WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE FRONT MOVES ACROSS THE AREA. ONCE THE BOUNDARY STALLS...AND INSTABILITY BECOMES TAPPED OUT...GENERAL RAIN SHOWERS SHOULD DOMINATE FROM LATE FRIDAY NIGHT ONWARD. TEMPERATURES THROUGH OUT THE UPCOMING WORK WEEKS WILL BE WELL ABOVE NORMAL AS THE RIDGE REMAINS ENTRENCHED SOUTHERLY TO SOUTHWESTERLY FLOW PERSISTS ACROSS THE REGION. HIGHS ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 60S ON MONDAY...IN THE LOW TO MID 70S TUESDAY THROUGH THURSDAY...AND AROUND 70 ON FRIDAY. IT WILL FEEL LIKE SPRING ALL WEEK. OVERNIGHT LOWS WILL ALSO BE WELL ABOVE NORMAL...WITH NIGHTLY MINIMUMS IN THE LOW TO MID 50S EVERY NIGHT EXCEPT MONDAY NIGHT...WHEN THE MERCURY IS EXPECTED TO DROP INTO THE LOW TO MID 40S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1250 PM EST SAT MAR 5 2016 A LOW PRESSURE SYSTEM IS DROPPING SOUTH ACROSS EAST KENTUCKY THIS AFTERNOON. THIS IS RESULTING IN SCATTERED TO NUMEROUS LIGHT RAIN SHOWERS MOVING IN FOR THE BULK OF THE AREA...LASTING INTO THE LATE AFTERNOON. KEPT WITH PREVAILING VCSH MENTION THROUGHOUT THE FIRST PART OF THE TAF ALONG WITH A FEW HOUR TEMPO GROUP TRYING TO HIT THE BEST TIMING FOR THESE SHOWERS AND LOWER CIGS/VIS. THE LOW AND ITS ASSOCIATED RAIN WILL QUICKLY EXIT EASTWARD OVERNIGHT. AS HIGH PRESSURE FILLS IN...ANOTHER NIGHT OF SUBSIDENCE W/ LLVL MOISTURE WILL SET UP...LIKELY LEADING TO MORE LOWER CIGS AND FOG DEVELOPMENT ACROSS THE REGION. OVERALL...WINDS SHOULD REMAIN LIGHT THROUGHOUT THE TAF PERIOD...PREDOMINATELY FROM THE SOUTHWEST BEFORE BECOMING MORE WESTERLY BEHIND THE COLD FRONT...AFTER 00Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...AR AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
220 PM EST SAT MAR 5 2016 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 220 PM EST SAT MAR 5 2016 18Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING SOUTH THROUGH EASTERN KENTUCKY ON ITS TREK TO THE SOUTHEAST COAST. THIS IS PUSHING A FAIRLY LARGE BAND OF SCATTERED TO NUMEROUS SHOWERS THROUGH THE CWA WITH GENERALLY A TENTH TO TWO TENTHS OF AN INCH OF RAIN EXPECTED. EARLIER...THIS LOW HELPED TO BREAK UP THE LOW CLOUDS AND FOG RELEASING THE AREA FROM CHILLY TEMPERATURES IN THE LOWER AND MIDDLE 30S. CURRENTLY...READINGS HAVE MADE IT INTO THE LOW 40S NORTH AND THE LOWER 50S SOUTH ON SOUTH TO SOUTHWEST WINDS. DEWPOINTS...MEANWHILE...HAVE ALSO CLIMBED WITH THE UPPER 30S AND 40S MOST COMMON AS THE RAIN STARTS TO MOVE IN. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST AS A COMPACT WAVE STRENGTHENS AND MOVES THROUGH THE SOUTHERN APPALACHIANS...TO THE SOUTHEAST COAST LATER TODAY AND INTO TONIGHT. THIS SHARP LITTLE FEATURE WILL BE FOLLOWED BY AN EQUALLY DISTINCT RIDGE BUILDING INTO KENTUCKY FROM THE SOUTHERN PLAINS. THIS RIDGE PLANTS ITSELF FIRMLY OVER THE AREA ON SUNDAY...BUILDING INTO MONDAY AS IT STARTS TO BE PUMPED UP DUE TO ITS POSITION DOWNSTREAM OF A LARGE DIGGING WEST COAST TROUGH. LOOK FOR THE RIDGE TO KEEP ANY MID LEVEL WAVES OF ENERGY TO THE NORTH OF THE AREA KEEPING THE WX QUIET. GIVEN THE MODEL AGREEMENT AND MAINLY JUST NEAR TERM WEATHER CONCERNS...HAVE FAVORED A GENERAL MODEL BLEND WITH STRONG LEAN TOWARD THE HRRR AND NAM12 SOLUTIONS. SENSIBLE WEATHER WILL FEATURE A RELATIVELY WEAK LOW PRESSURE SFC WAVE PASSING THROUGH EAST KENTUCKY WITH BULK OF THE SHOWERS MOVING THROUGH THIS AFTERNOON AND GRADUALLY DIMINISHING INTO THE EVENING FROM NORTHWEST TO SOUTHEAST. COOLER AIR DOES FOLLOW THIS LOW BUT NOT ENOUGH TO WORRY ABOUT ANY SNOW MIXING IN BEFORE THE LAST OF THE PCPN DEPARTS. OF A LARGER CONCERN WILL BE THE POTENTIAL FOR FOG DEVELOPING AGAIN TONIGHT. GIVEN THE AMPLE LOW LEVEL MOISTURE LEFT BEHIND AROUND AND ANTICIPATED SUBSIDENCE INVERSION HAVE HIT THE FOG RATHER HARD IN THE GRIDS WITH SOME AREAS HAVING SOME DENSE FOG. RIDGES MAY SEE LOW VISIBILITIES...AS WELL...WITH THE LOW CLOUDS SETTLING IN AFTER MIDNIGHT. THIS WILL ALL CLEAR OUT FAIRLY QUICKLY ON SUNDAY...THOUGH...WITH SUNSHINE RETURNING AND SOUTHERLY WINDS HELPING TO BRING TEMPS BACK INTO THE LOWER AND MIDDLE 50S BY AFTERNOON...FOR MOST PLACES. HIGH PRESSURE MOVING OFF TO THE EAST WILL LIKELY SET THE STAGE FOR A DECENT RIDGE TO VALLEY TEMPERATURE SPLIT SUNDAY NIGHT INTO MONDAY MORNING UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. ALSO...WOULD ANTICIPATE SOME VALLEY FOG DEVELOPING LATE SUNDAY NIGHT THROUGH DAWN MONDAY. USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THE NIGHT BEFORE FAVORING THE SUPERBLEND THEREAFTER. MADE THE MOST SIGNIFICANT CHANGES TO THE T GRIDS ON SUNDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE AND VALLEY DISTINCTIONS. AS FOR POP...ENDED UP CLOSEST TO THE HIGHER MET VALUES INTO THE EVENING BEFORE NEARLY ZEROING THEM OUT THROUGH MONDAY MORNING...IN LINE WITH GUIDANCE. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 359 AM EST SAT MAR 5 2016 WARMING TEMPERATURES AND A DRY START TO THE WEEK REMAIN IN THE OFFING COURTESY OF BUILDING HEIGHTS/THICKNESSES ASSOCIATED WITH BROAD EASTERN CONUS RIDGING. FURTHER WARMING WILL ENSUE AS FLOW BACKS SOUTHWEST ALOFT IN RESPONSE TO AN UPPER LEVEL LOW DIGGING THROUGH BAJA CALIFORNIA INTO CHIHUAHUA MEXICO. WELL ABOVE NORMAL TEMPERATURES WILL BE THE RULE WITH HIGHS LOOKING TO TOP OUT BETWEEN THE MID 60S TO MID 70S AS LOWS FROM TUESDAY MORNING INTO THE WEEKEND ONLY FALL INTO THE MID 40S TO MID 50S. GIVEN THE DEEP SOUTHERN TRACK OF THE AFOREMENTIONED SYSTEM...SURFACE LOW PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS WILL BE SLOW TO EJECT EASTWARD IN AN AMPLIFIED PATTERN AS SURFACE RIDGING ESTABLISHES A LENGTHY RESIDENCE TIME ACROSS THE MID TO SOUTHERN ATLANTIC COAST. THIS WILL LIKELY KEEP ANY EARLIER WEEK RAINFALL...RESULTING FROM AN INITIAL SHORTWAVE IMPULSE...WELL WEST OF INTERSTATE 71. PROSPECTS FOR RAINFALL ACROSS CENTRAL INTO EASTERN KENTUCKY LOOK TO BECOME MUCH BETTER FOR MID-LATE WEEK AS UPPER ENERGY APPROACHES IN TANDEM WITH A SURFACE LOW AND PLENTY OF DEEP LAYER MOISTURE. APPRECIABLE THUNDER CHANCES CONTINUE TO LOOK POSSIBLE AS LONG AS INSTABILITY CAN MATERIALIZE AMID PLENTY OF MID- HIGH CLOUD COVER. A NORTHERN STREAM TROUGH MAY ALSO ATTEMPT TO DIVE FAR ENOUGH SOUTH TO AID IN PROVIDING ADDITIONAL LIFT FOR SHOWER/THUNDERSTORM POTENTIAL. DEPENDING ON THE TRACK/EVOLUTION OF THE UPPER LOW...RAINFALL COULD VERY WELL LAST INTO THE WEEKEND. WILL HAVE TO MONITOR HEAVY RAIN/FLOODING THREAT GOING FORWARD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1250 PM EST SAT MAR 5 2016 A LOW PRESSURE SYSTEM IS DROPPING SOUTH ACROSS EAST KENTUCKY THIS AFTERNOON. THIS IS RESULTING IN SCATTERED TO NUMEROUS LIGHT RAIN SHOWERS MOVING IN FOR THE BULK OF THE AREA...LASTING INTO THE LATE AFTERNOON. KEPT WITH PREVAILING VCSH MENTION THROUGHOUT THE FIRST PART OF THE TAF ALONG WITH A FEW HOUR TEMPO GROUP TRYING TO HIT THE BEST TIMING FOR THESE SHOWERS AND LOWER CIGS/VIS. THE LOW AND ITS ASSOCIATED RAIN WILL QUICKLY EXIT EASTWARD OVERNIGHT. AS HIGH PRESSURE FILLS IN...ANOTHER NIGHT OF SUBSIDENCE W/ LLVL MOISTURE WILL SET UP...LIKELY LEADING TO MORE LOWER CIGS AND FOG DEVELOPMENT ACROSS THE REGION. OVERALL...WINDS SHOULD REMAIN LIGHT THROUGHOUT THE TAF PERIOD...PREDOMINATELY FROM THE SOUTHWEST BEFORE BECOMING MORE WESTERLY BEHIND THE COLD FRONT...AFTER 00Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...GUSEMAN AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
110 PM EST SAT MAR 5 2016 .UPDATE... ISSUED AT 110 PM EST SAT MAR 5 2016 THE TEMPERATURES HAVE NOW PROPERLY REBOUNDED SO HAVE MAINLY ADJUSTED THE FORECAST WITH THIS UPDATE TO ACCOUNT FOR THE INBOUND SHOWERS FROM THE NORTHWEST. ALSO...DID FINE TUNE THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. UPDATE ISSUED AT 955 AM EST SAT MAR 5 2016 14Z SFC ANALYSIS SHOWS LOW PRESSURE DIVING SOUTHEAST THROUGH THE GREAT LAKES WITH A WEAK COLD FRONT PASSING THE MID MISSISSIPPI VALLEY. HERE TO THE EAST...A MID LEVEL DISTURBANCE IS DEPARTING THE CENTRAL APPALACHIANS. THIS IS RESULTING IN SOME LIGHT PCPN DROPPING THROUGH EAST KENTUCKY THIS MORNING. IN ADDITION TO THE SPRINKLES AND LIGHT RAIN...AREAS OF FOG...LOCALLY DENSE...PLAGUED THE HIGHER ELEVATIONS THROUGH EAST KENTUCKY EARLY THIS MORNING. THE FOG IS STARTING TO DISSIPATE WITH IMPROVING VISIBILITY AND LIFTING CEILINGS. HOWEVER...THE LOW CLOUDS AND PCPN ARE RETARDING A TEMPERATURE RISE SO FAR THIS MORNING WITH MOST PLACES STILL IN THE LOW 30S. THE APPROACH OF THE WEAKENING LOW AND ITS FRONT SHOULD MIX OUT THE LOWER CLOUDS BY MIDDAY WITH WARMING TEMPERATURES THE RESULT...THOUGH ANOTHER ROUND MORE SUBSTANTIVE SHOWERS WILL LIKELY DEVELOP AND CROSS EAST KENTUCKY THIS AFTERNOON. HAVE ADJUSTED THE FORECAST TO SLOW THE TEMP RISE THIS MORNING AND TO FINE TUNE THE POPS/WX THROUGH THE AFTERNOON PER THE LATEST HRRR AND NAM12. DID ALSO TWEAK THE DEWPOINTS...CURRENTLY REPORTING SIMILAR VALUES TO DRY TEMPS AT MOST SITES...PER THE LATEST OBS AND TRENDS. LIGHT WINDS EARLY THIS MORNING WILL SHIFT TO THE SOUTHWEST AND PICK UP TO NEAR 10 MPH THIS AFTERNOON ALSO HELPING TEMPS TO REBOUND INTO THE 40S. THE GRID UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS...WITH A FRESHENED SET OF ZONES AND HWO ALSO ISSUED. UPDATE ISSUED AT 656 AM EST SAT MAR 5 2016 CURRENT RADAR IS SHOWING A LINE OF PRECIPITATION MOVING ACROSS THE NORTHERN PORTION OF THE CWA. ACCORDING TO THE LATEST OBSERVATIONS...PRECIP IS LIKELY STILL NOT HITTING THE GROUND...WITH ONLY ONE BRIEF OBSERVATION OF LIGHT SNOW IN THE CINCINNATI AREA UNDER A HIGHER RETURN OVER THE LAST HOUR. IT IS POSSIBLE THAT SOME FLURRIES ARE OCCURRING OUT OF THIS GIVEN TEMPERATURES AT OR NEAR THE FREEZING MARK...BUT NOTHING IS EXPECTED TO ACCUMULATE. OVER THE NEXT HOUR...EXPECT RETURNS TO INTENSIFY AND PRECIP TO BEGIN HITTING THE GROUND...BUT NOT BEFORE TEMPERATURES BEGIN A WARMING TREND ABOVE FREEZING AND PRECIP CHANGES TO MAINLY RAIN. MEANWHILE...STILL SEEING QUITE A BIT OF FOG ACROSS THE REMAINDER OF THE CWA...THOUGH THERE HAS BEEN SIGNS OF VIS IMPROVEMENT AT MANY SITES. ACCORDING TO THE OBS IT SEEMS AS THOUGH MUCH OF THE FOG IS ELEVATED AT THIS POINT...MAINLY AFFECTING THE RIDGE TOPS. SEVERAL OBSERVATIONS ACROSS EASTERN KY ARE ALSO STILL REPORTING TEMPS AT OR JUST BELOW 32 DEGREES...SO WILL CONTINUE MENTION OF FREEZING FOG AS WELL IN THE GRIDS FOR THE NEXT HOUR. CURRENT SPS HIGHLIGHTING PATCHY DENSE FOG AND POSSIBLE SLICK CONDITIONS FROM FREEZING FOG/SLICK ROADWAYS WILL BE ALLOWED TO EXPIRE AT 7AM...AS FOG SHOULD CONTINUE LIFTING/MIXING OUT AND TEMPERATURES WILL BE WARMING AFTER THIS POINT. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 349 AM EST SAT MAR 5 2016 LINGERING LLVL MOISTURE AND STRONG SUBSIDENCE IN PLACE THROUGH THE FIRST PART OF THE NIGHT HAS LED TO FOG DEVELOPMENT ACROSS MUCH OF THE CWA. GIVEN TEMPERATURES AT OR BELOW FREEZING IN MANY LOCATIONS AS WELL...THIS ALSO CREATED A SET UP FOR POTENTIAL FREEZING FOG. AN AREA OF LOW PRESSURE IS CURRENTLY MOVING EASTWARD INTO THE UPPER GREAT LAKES REGION AS OF 8Z THIS MORNING. THIS IS PUSHING THE SURFACE HIGH IN PLACE EAST OF THE REGION...AND ALLOWING MID AND UPPER LEVEL MOISTURE TO BEGIN FILTERING INTO THE REGION. DESPITE THIS...SOUNDINGS STILL SUPPORT A DECENT LLVL INVERSION WHICH WILL LIKELY KEEP THE FOG AND FREEZING FOG IN PLACE THROUGHOUT THE REST OF THE NIGHT. BY 12Z THIS MORNING...THE LOW IS EXPECTED TO BEGIN QUICKLY DROPPING SOUTHEASTWARD...CLIPPING THE FAR NE PORTION OF THE STATE BY LATE THIS AFTERNOON...BEFORE EXITING EASTWARD OVERNIGHT. THIS QUICK DROP SOUTHWARD WILL LIKELY CLEAR OUT ANY REMAINING FOG ACROSS THE REGION. OVERALL THIS SYSTEM IS BOTH FAST MOVING AND RELATIVELY WEAK. HOWEVER...THERE WILL BE ENOUGH MOISTURE SUPPORT FROM LLVL SRLY WINDS TO PROMOTE SOME SCATTERED BUT LIGHT PRECIP POTENTIAL ACROSS THE CWA. LATEST HI RES MODELS ARE SHOWING PRECIP DEVELOPING ALONG OUR FAR NW CWA AROUND OR JUST AFTER 12Z THIS MORNING...WITH SCATTERED ACTIVITY OVERSPREADING FROM NW TO SE THROUGHOUT THE DAY...THEN EXITING TO OUR EAST OVERNIGHT. BEST QPF AND POPS WILL BE ACROSS THE NORTHERN AND FAR EASTERN CWA...CLOSEST TO THE CENTER OF THE LOW. WILL CONTINUE TO MONITOR THE TEMPERATURES AS THE PRECIP BEGINS TO NEAR THE REGION THIS MORNING...AS IT IS LIKELY THAT BELOW FREEZING TEMPS COULD LEAD TO SOME SNOW AT ONSET...BEFORE CHANGING OVER TO ALL RAIN AS CONDITIONS WARM TO ABOVE FREEZING AFTER 12Z. OVERALL...NOT LOOKING AT ANY ACCUMULATIONS IF SNOW DOES OCCUR...AND SHOULD BE A PRETTY QUICK TURNOVER. OTHERWISE...TEMPERATURES WILL REMAIN ABOVE FREEZING THROUGHOUT THE DURATION OF THE EVENT...SO REST OF PRECIP SHOULD FALL AS ALL RAIN. AMPLIFIED RIDGING WILL SHIFT EASTWARD ACROSS KY BEHIND THE EXITING SHORTWAVE AND LOW PRESSURE SYSTEM TONIGHT AND THROUGH THE DAY SUNDAY. WITH LINGERING MOISTURE IN PLACE ONCE MORE TONIGHT...AND STRONG SUBSIDENCE TAKING HOLD...EXPECT SOME FOG DEVELOPMENT TO RESULT ONCE MORE. IT IS POSSIBLE THAT THERE COULD BE SOME WIDESPREAD AND/OR DENSE FOG IN LOCATIONS THAT RECEIVE RAINFALL TODAY...AND NEAR SOME BODIES OF WATER. HOWEVER...GIVEN THE LOW CONFIDENCE ON WHERE BEST IMPACTS FROM RAIN WILL BE...JUST STUCK WITH PATCHY FOG MENTION ACROSS ENTIRE CWA AT THIS TIME. SURFACE HIGH PRESSURE WILL ACCOMPANY THIS AMPLIFIED RIDGING...CROSSING DIRECTLY OVER KY DURING THE DAY SUNDAY. AS A RESULT...EXPECT LIGHT WINDS...CLEARING SKIES...AND TEMPERATURES WARMING INTO THE MID 50S. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 359 AM EST SAT MAR 5 2016 WARMING TEMPERATURES AND A DRY START TO THE WEEK REMAIN IN THE OFFING COURTESY OF BUILDING HEIGHTS/THICKNESSES ASSOCIATED WITH BROAD EASTERN CONUS RIDGING. FURTHER WARMING WILL ENSUE AS FLOW BACKS SOUTHWEST ALOFT IN RESPONSE TO AN UPPER LEVEL LOW DIGGING THROUGH BAJA CALIFORNIA INTO CHIHUAHUA MEXICO. WELL ABOVE NORMAL TEMPERATURES WILL BE THE RULE WITH HIGHS LOOKING TO TOP OUT BETWEEN THE MID 60S TO MID 70S AS LOWS FROM TUESDAY MORNING INTO THE WEEKEND ONLY FALL INTO THE MID 40S TO MID 50S. GIVEN THE DEEP SOUTHERN TRACK OF THE AFOREMENTIONED SYSTEM...SURFACE LOW PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS WILL BE SLOW TO EJECT EASTWARD IN AN AMPLIFIED PATTERN AS SURFACE RIDGING ESTABLISHES A LENGTHY RESIDENCE TIME ACROSS THE MID TO SOUTHERN ATLANTIC COAST. THIS WILL LIKELY KEEP ANY EARLIER WEEK RAINFALL...RESULTING FROM AN INITIAL SHORTWAVE IMPULSE...WELL WEST OF INTERSTATE 71. PROSPECTS FOR RAINFALL ACROSS CENTRAL INTO EASTERN KENTUCKY LOOK TO BECOME MUCH BETTER FOR MID-LATE WEEK AS UPPER ENERGY APPROACHES IN TANDEM WITH A SURFACE LOW AND PLENTY OF DEEP LAYER MOISTURE. APPRECIABLE THUNDER CHANCES CONTINUE TO LOOK POSSIBLE AS LONG AS INSTABILITY CAN MATERIALIZE AMID PLENTY OF MID- HIGH CLOUD COVER. A NORTHERN STREAM TROUGH MAY ALSO ATTEMPT TO DIVE FAR ENOUGH SOUTH TO AID IN PROVIDING ADDITIONAL LIFT FOR SHOWER/THUNDERSTORM POTENTIAL. DEPENDING ON THE TRACK/EVOLUTION OF THE UPPER LOW...RAINFALL COULD VERY WELL LAST INTO THE WEEKEND. WILL HAVE TO MONITOR HEAVY RAIN/FLOODING THREAT GOING FORWARD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1250 PM EST SAT MAR 5 2016 A LOW PRESSURE SYSTEM IS DROPPING SOUTH ACROSS EAST KENTUCKY THIS AFTERNOON. THIS IS RESULTING IN SCATTERED TO NUMEROUS LIGHT RAIN SHOWERS MOVING IN FOR THE BULK OF THE AREA...LASTING INTO THE LATE AFTERNOON. KEPT WITH PREVAILING VCSH MENTION THROUGHOUT THE FIRST PART OF THE TAF ALONG WITH A FEW HOUR TEMPO GROUP TRYING TO HIT THE BEST TIMING FOR THESE SHOWERS AND LOWER CIGS/VIS. THE LOW AND ITS ASSOCIATED RAIN WILL QUICKLY EXIT EASTWARD OVERNIGHT. AS HIGH PRESSURE FILLS IN...ANOTHER NIGHT OF SUBSIDENCE W/ LLVL MOISTURE WILL SET UP...LIKELY LEADING TO MORE LOWER CIGS AND FOG DEVELOPMENT ACROSS THE REGION. OVERALL...WINDS SHOULD REMAIN LIGHT THROUGHOUT THE TAF PERIOD...PREDOMINATELY FROM THE SOUTHWEST BEFORE BECOMING MORE WESTERLY BEHIND THE COLD FRONT...AFTER 00Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JMW LONG TERM...GUSEMAN AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
259 PM EST SAT MAR 5 2016 .SYNOPSIS... WEAK LOW PRESSURE WILL MOVE QUICKLY ACROSS THE AREA TONIGHT INTO EARLY SUNDAY MORNING. HIGH PRESSURE RETURNS LATER SUNDAY AND WILL PERSIST OVER THE SOUTHEASTERN STATES THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH SUNDAY/... SFC HIGH PRESSURE IS CENTERED NEAR THE VA TIDEWATER THIS AFTERNOON AS THE WEAK CLIPPER LOW DIVES INTO THE OHIO VALLEY. THE FLURRIES WITH THE LEAD DISTURBANCE ALOFT HAVE DISSIPATED...AND BEHIND IT THERE HAVE BEEN SOME BREAKS IN THE CLOUDS. BULK OF THE AFTERNOON WILL REMAIN DRY ACROSS MOST OF THE AREA. TWO AREAS OF PRECIP TO OUR WEST TO WATCH...EACH ASSOCIATED WITH A VORT MAX ALOFT. ONE AREA IS CURRENTLY MOVING INTO EASTERN KY WHILE THE OTHER DROPS SE FROM MI. HAVE LARGELY BASED THE POPS FOR THIS EVENING AND OVERNIGHT ON THE RAP AND HRRR...WITH SOME SUPPORT FROM OTHER HI-RES MODELS AND THE NAM/GFS. ECMWF IS A NOTABLE DRY OUTLIER AND IS NOT TOTALLY OUT OF THE REALM OF POSSIBILITY...THUS WHY POPS HAVE BEEN KEPT AT 60 PCT OR LOWER EXCEPT ALONG THE ALLEGHENY FRONT. THE FORECAST HINGES ON THE TWO AREAS OF PRECIP MERGING AND PROCEEDING ACROSS THE MOUNTAINS. EVEN IF IT DOES...QPF WILL BE RATHER LIGHT AS THE SFC LOW FIZZLES AND THE PRIMARY VORT MAX IN THE TROUGH HEADS TO THE SE STATES. THE TREND WITH THE MORNING GUIDANCE WAS TO REDUCE QPF ALONG THE PA BORDER. KIND OF DOUBT COVERAGE IS COMPLETELY UNIFORM EITHER. HAVE CONTINUED TO INDICATE A TRANSITION TO RA/SN MIX THEN SN GENERALLY WEST OF I-95. LOW TEMPS WILL FALL TO NEAR THE FREEZING MARK AND FORECAST SOUNDINGS ARE NOT AS COLD ALOFT AS THE EVENT A COUPLE DAYS AGO. SO ALL PUT TOGETHER...SOME PLACES COULD RECEIVE A SLUSHY COATING (BUT NOT NECESSARILY ALL)...WITH A WORST CASE BEING UP TO AN INCH. 1-2 INCHES REMAIN POSSIBLE ALONG THE ALLEGHENY FRONT. FAIRLY GOOD TIMING AGREEMENT THAT THE TROUGH AXIS WILL BE PASSING QUICKLY TO THE EAST AT 12Z SUNDAY...ALLOWING ANY LINGERING SHOWERS TO EXIT BY 9 AM OR SO. HOWEVER CLOUDS MAY NOT BE AS QUICK TO DEPART...ALTHOUGH SUN SHOULD BREAK THROUGH BY AFTERNOON. HIGHS WILL BE ABLE TO REBOUND INTO THE MID 40S TO LOWER 50S. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... RIDGING AT THE SFC AND ALOFT WILL BUILD IN EARNESTLY SUNDAY NIGHT. AMOUNT OF MID AND HIGH CLOUDS WILL DETERMINE THE EFFECTIVENESS OF RADIATIONAL COOLING. WILL FORECAST LOWS ON EITHER SIDE OF FREEZING. && .LONG TERM /TUESDAY THROUGH SATURDAY/... WINDS WILL HAVE SHIFTED TO SOUTHERLY MONDAY MORNING ACROSS THE ENTIRE AREA...AS SFC HIGH SHIFTS TO OUR SOUTHEAST AND WAA COMMENCES. LONG PERIOD OF UNINTERRUPTED RETURN FLOW WILL ALLOW AIRMASS TO WARM/MOISTEN SUBSTANTIALLY FROM MONDAY THROUGH AT LEAST WEDNESDAY...AS SFC HIGH REMAINS ANCHORED TO OUR SOUTHEAST AND LARGE EAST COAST RIDGE DEVELOPS. RECORDS APPEAR SAFE AT THIS POINT...THOUGH WITH HIGHS IN THE M/L 70S BY WEDNESDAY...NEARLY 20 DEGREES ABOVE NORMAL...IT WILL FEEL MORE LIKE EARLY MAY. CHANGES MAY ARRIVE TO PARTS OF THE AREA THURSDAY...AS WEAK FRONT POSSIBLY NUDGES ITS WAY INTO THE NORTHERN HALF OF THE AREA. GFS MORE AGGRESSIVE THAN ECMWF WITH QPF OVER THE AREA THURSDAY...WHILE ECMWF KEEPS MEANINGFUL QPF CONFINED TO OUR FAR NORTHWEST UNTIL EARLY FRIDAY MORNING WITH THE FRONT THEN WASHING OUT OVER THE AREA. EAST COAST RIDGE BEGINS TO BREAK DOWN AND SHIFT EAST FRIDAY INTO SATURDAY...AS UPPER LOW...THAT HAD BEEN DISLODGED FROM THE MAIN FLOW...BEGINS TO EJECT OUT OF THE SOUTHERN PLAINS. THIS SETS UP AN UNSETTLED PERIOD...THOUGH SPATIOTEMPORAL SPREAD OF THE KEY FEATURES DURING THIS TIME IS RATHER LARGE...WHICH PREVENTS NOTHING MORE THAN CHC POPS THROUGH THE PERIOD. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... LOOKING DOUBTFUL THERE WILL BE ANY IMPACTS AT THE TERMINALS THROUGH EARLY EVENING...JUST CONTINUED CIGS NEAR FL050 AT TIMES. WEAK DISTURBANCE PUSHES THROUGH TONIGHT. THINK AT A MINIMUM THERE WILL BE A PERIOD OF MVFR CIGS. PRECIP IS A LITTLE MORE IN DOUBT. HAVE ADVERTISED A PERIOD OF RAIN AND/OR SNOW SHOWERS OVERNIGHT...ALTHOUGH WIDESPREAD COVERAGE IS NOT GUARANTEED. HAVE THUS LIMITED VSBY RESTRICTIONS TO MVFR FOR NOW AND WILL NOTE HERE THAT IFR IS POSSIBLE...ESPECIALLY IN ANY SNOW. ANY THREAT OF PRECIP WILL LIKELY END BY 12Z. HOWEVER CIGS MAY BE SLOW TO SCATTER OUT AND HAVE LEFT MENTION OF CLOUDS AROUND FL050 THROUGHOUT SUNDAY. SE WINDS 5-10 KT THIS AFTERNOON...BECOMING VRB TONIGHT...THEN NORTHERLY 5-10 KT SUNDAY. VFR CONDITIONS ARE EXPECTED SUNDAY NIGHT AS HIGH PRESSURE BUILDS. VFR MONDAY THROUGH MIDWEEK UNDER HIGH PRESSURE. && .MARINE... LIGHT S/SE FLOW ON THE WATERS THIS AFTERNOON AS HIGH PRESSURE DEPARTS. WEAK LOW PRESSURE CROSSES THE AREA TONIGHT WITH LITTLE IN THE WAY OF WINDS BUT PERHAPS A LIGHT RAIN OR SNOW SHOWER. NORTHERLY WINDS DEVELOP SUNDAY...ALTHOUGH STILL LOOKING LIKE THEY WILL REMAIN BELOW SCA. LIGHT SOUTHERLY FLOW DEVELOPS SUNDAY NIGHT. WINDS FOLLOW A DIURNAL CYCLE BEYOND MONDAY...WITH ELEVATED/LIGHT SOUTHERLY WINDS DURING THE DAY/NIGHT. ATTM...IT APPEARS WINDS REMAIN AOB SCA...THOUGH THERE COULD BE PERIODS OF WIND GUSTS NEAR SCA DURING THE AFTERNOONS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...ADS NEAR TERM...ADS SHORT TERM...ADS LONG TERM...MSE AVIATION...ADS/MSE MARINE...ADS/MSE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
315 PM EST SAT MAR 5 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 445 AM EST SAT MAR 5 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS A RIDGE OVER THE ROCKIES AND A TROF OVER ERN NAMERICA. SHORTWAVE THAT BROUGHT SNOW INTO UPPER MI OVER THE LAST 12HRS OR SO IS TRACKING SE THRU WI. THIS WILL BE THE FINAL SHORTWAVE TO DROP SE THRU THE AREA BEFORE A TRANSITION TO A WARM SPLIT FLOW PATTERN WITH ABOVE NORMAL HEIGHTS AND W TO SW FLOW ACROSS THE UPPER GREAT LAKES NEXT WEEK. RADAR TRENDS OVER THE LAST COUPLE OF HRS SHOW SNOW DIMINISHING OVER UPPER MI...AND UPSTREAM... KDLH RADAR SHOWS VERY LITTLE PCPN REMAINING. THERE WERE OBS AND REPORTS OF SOME -FZDZ EARLIER IN THE NIGHT OVER WRN UPPER MI AND NRN WI AS THE HEAVIER SNOW DEPARTED. RECENTLY...THERE ARE FEWER OBS SHOWING UNKNOWN PCPN...SO -FZDZ MAY BE DIMINISHING. WITH SHORTWAVE CONTINUING SE TODAY...DIMINISHING PCPN WILL END FROM NW TO SE. SOUTHERLY FLOW ON LAKE MI PERSISTS THRU MID TO LATE MORNING WHICH SHOULD HELP WEAKLY LAKE ENHANCED SNOW TO LINGER. THUS...HIGHEST POPS WILL PAINTED OVER THE E THIS MORNING WITH PERHAPS ANOTHER HALF INCH OR SO OF SNOW ACCUMULATION. TO THE W... WILL KEEP A MENTION OF -FZDZ/-SN MAINLY IN THE COUNTIES BORDERING WI FOR THE NEXT FEW HRS. SATELLITE IMAGERY SHOWS CLEARING NOT THAT FAR AWAY ACROSS NRN LAKE SUPERIOR. WITH HIGH PRES RIDGE BUILDING INTO THE UPPER GREAT LAKES THIS AFTN...LOW-LEVEL NORTHERLY WINDS AHEAD OF THE RIDGE WILL DIMINISH. THIS INCREASES THE UNCERTAINTY IN HOW MUCH CLEARING WILL OCCUR...ESPECIALLY SINCE UPSLOPE FLOW OFF THE LAKE UNDER A LOWERING INVERSION SHOULD GREATLY SLOW THE CLEARING PROCESS. KEWEENAW OBVIOUSLY HAS THE BEST CHC OF AT LEAST PARTIALLY CLEARING OUT TODAY GIVEN THE CLOSE PROXIMITY OF CLEAR SKIES ALREADY EARLY THIS MORNING. FOR NOW...FCST WILL SHOW A VERY GRADUAL DECREASE IN CLOUDS FROM THE N AND NW THIS AFTN INTO THIS EVENING. CLOUD FCST INTO TONIGHT REMAINS A BIT TRICKY. IF THE EXTENSIVE LOW CLOUDS ACROSS MN/WI PERSIST THRU THE DAY...THESE CLOUDS MAY MOVE BACK INTO THE AREA TONIGHT ONCE S TO SW FLOW DEVELOPS/INCREASES AFTER THE HIGH PRES RIDGE PASSES. OTHERWISE...PROVIDED MUCH OF TODAYS CLOUD COVER DEPARTS BY EVENING...THERE WILL BE AN OPPORTUNITY FOR TEMPS TO FALL QUICKLY THIS EVENING UNDER LIGHT/CALM WIND. LEANED FCST TO THE COLDER BIAS CORRECTED REGIONAL/GLOBAL CANADIAN MODELS DUE TO THEIR NORMAL SUPERIOR PERFORMANCE IN RADIATIONAL COOLING SITUATIONS. TRADITIONAL COLD SPOTS WILL FALL DOWN INTO THE MID TEENS IF SKIES ARE MOSTLY CLEAR THIS EVENING. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 314 PM EST SAT MAR 5 2016 THE MEDIUM/LONG RANGE FCST PERIOD WL FEATURE WELL ABOVE NORMAL TEMPS WITH PACIFIC AIR/ABOVE NORMAL HGTS DOMINATING THE CONUS. WHILE THERE COULD BE SOME RA SHOWERS ON MON/TUE ASSOCIATED WITH A SHRTWV RIDING NEWD OUT OF THE PLAINS TOWARD THE WRN GREAT LKS...RA TOTALS SHOULD BE LIMITED OVERALL. OTRW...MOST OF THE MEDIUM/EXTENDED RANGE PERIOD WL BE DRY. SUN NGT/MON...GUSTY SW WINDS SUN EVNG WL DIMINISH THRU THE NGT AS THE PRES GRADIENT RELAXES WITH PASSAGE OF ONTARIO SHRTWV/PRES FALL CENTER TO THE E...SO THE GUSTY WINDS WL SUBSIDE. SOME OF THE MODELS GENERATE SOME LGT PCPN OVER MAINLY THE SE CWA IN THE EVNG RELATED TO AREA OF SHARPER ISENTROPIC ASCENT BEST SHOWN ON THE 300K SFC /ABOUT H7/ AND SOME MODEST ELEVATED INSTABILITY ABOVE THE ACCOMPANYING H85- 7 WARMING. BUT ANY OF THIS PCPN SHOULD DIMINISH OVERNGT WITH EXIT OF THE SHARPER ISENTROPIC ASCENT AND ONSET OF MID LVL DRYING AS UPR RDG BUILDS INTO THE AREA WITH FCST SDNGS SHOWING MORE MID LVL DRYING/ CAPPING. DESPITE THESE NEGATIVE DYNAMICS...MANY OF THE MODEL CONTINUE TO GENERATE SOME SPOTTY LGT PCPN THRU THE NGT AND ON MON OVER MUCH OF THE CWA. SUSPECT THIS PCPN IS RELATED TO FCST GRADUAL INFLUX OF LLVL MSTR...SO WL MAINTAIN FCST OF DRIZZLE/FOG DVLPG OVER MELTING SN COVER IN THE PRSENCE OF SOME NOCTURNAL COOLING INTO MON MRNG. EXPECT WELL ABOVE NORMAL TEMPS WITH MIN TEMPS HOLDING ABOVE 32 ON SUN NGT. ALTHOUGH THE LINGERING LO CLDS ON MON WL LIMIT THE DIURNAL TEMP RECOVERY...TEMPS WL STILL TOP OUT IN THE 40S TO PERHAPS AS HI AS 50 OVER THE FAR W AS H85 TEMPS REBOUND. MON NGT/TUE...A SHRTWV MOVING THRU THE WRN PLAINS ON MON IS FCST TO LIFT NEWD AND INTO MN ON TUE...TENDING TO SHEAR OUT IN THE PROCESS. THIS TREND...ALONG WITH LINGERING MID LVL DRY AIR UNDER THE HIER HGTS/DRY SLOTTING TO THE E OF THE SHRTWV TRACK...WL LIMIT OVERALL POPS AND QPF. BEST CHANCE FOR THE SOMEWHAT HIER POPS WL BE LATE MON NGT/TUE MRNG SINCE THE SFC LO IS FCST TO PASS TO THE W THRU MN ON TUE AND THE AIRMASS WL BE UNSEASONABLY WARM WITH H85 TEMPS FCST AS HI AS 8 TO 9C...ANY PCPN WL BE IN THE FORM OF RA AS SFC TEMPS RISE AOA 50 ON TUE AWAY FM THE COOLING INFLUENCE OF LK MI. THE PERSISTENT SLY FLOW AND INFLUX OF WARMER/MOISTER LLVL AIR INTO THE CWA WL BRING MORE FOG AND SOME DRIZZLE...ESPECIALLY AWAY FM THE DOWNSLOPE AREAS ACRS THE NW CWA. STILL THINK THERE IS THE POTENTIAL FOR AN ELEVATED TS LATE MON NGT/TUE WITH ARRIVAL OF H7-5 LAPSE RATES AS HI AS 7.5- 8.5C/KM DESPITE CONCERNS THAT MID LVL DRY AIR/CAPPING MIGHT BE TOO PRONOUNCED TO ALLOW DEEP CONVECTION IN THE ABSENCE OF SGNFT DEEP LYR QVECTOR CNVGC WITH MORE SHEARED OUT SHRTWV. THE 12Z GFS CONTINUES THE TREND FM THAT MODEL SHOWING A FASTER COLD FROPA ON TUE WITH THIS BNDRY REACHING NEWBERRY NEAR 00Z WED. ALTHOUGH THE HI AMPLITUDE UPR RDG OVER THE ERN CONUS WOULD SUPPORT THE SLOWER MAJORITY...THE 00Z GFS ENSEMBLE MEAN SUPPORTS THE OPS MODEL SCENARIO. SO WL USE A MODEL BLEND TO REFLECT THE UNCERTAINTY. TUE NGT...THERE REMAINS SOME UNCERTAINTY ON THE DEGREE OF DRYING/ LARGER SCALE SUBSIDENCE THAT WL FOLLOW THE DEPARTING SHRTWV/COLD FROPA ON TUE NGT AS SOME OF THE MEDIUM RANGE MODELS SHOW AT LEAST ANOTHER SHRTWV FOLLOWING INTO THE AREA IN THE WSW FLOW ALOFT. SO WL MAINTAIN SOME LO CHC POPS REFLECTED IN THE MODEL CONSENSUS. WED THRU SAT...A ZONAL FLOW OF MARITIME POLAR PACIFIC AIR IS FCST TO DOMINATE THRU MID WEEK...WITH TENDENCY FOR AN UPR RDG TO BLD OVER CENTRAL NAERMICA TOWARD NEXT WEEKEND. THE RESULT WL BE ABOVE NORMAL TEMPS. ALTHOUGH A SHRTWV EMBEDDED IN THE ZONAL FLOW IS FCST TO PASS THE UPR LKS IN THE THU/FRI TIME FRAME...LARGER SCALE ACYC FLOW ARND HI PRES PASSING THRU ONTARIO WL HOLD DOWN PCPN CHCS. A LO PRES. MORE RA COULD ARRIVE NEXT WEEKEND AS A LO PRES ADVANCING SLOWLY TO THE N TOWARD THE LOWER LKS CLOSES IN ON THE AREA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1241 PM EST SAT MAR 5 2016 VFR CEILINGS AND VIS WILL BE THE RULE THROUGH THE NEXT 24HRS. THE ONLY HOLDOUT WILL BE INITIALLY THIS AFTERNOON AS THE END OF LAKE ENHANCED MAINLY MVFR CLOUD COVER SINKS ACROSS UPPER MI /ENDING LAST AT IWD AND SAW BY 23Z/. HIGH PRESSURE OVER WESTERN LAKE SUPERIOR...STRETCHING FROM S MN/IA WILL BRIEFLY TAKE HOLD OF UPPER MI FOR THE REST OF THE AFTERNOON HOURS...BEFORE QUICKLY EXITING ACROSS LOWER MI THIS EVENING. A STRONG PRESSURE GRADIENT WILL SET UP ACROSS THE AREA OVERNIGHT AND REMAIN THROUGH THE DAY SUNDAY. THIS WILL BE THE RESULT OF THE EXITING INTO THE MID ATLANTIC STATES...AND LOW PRESSURE TRACKING ACROSS S CANADA THIS EVENING TO SLIDE ACROSS S MANITOBA AND ND BY DAYBREAK SUNDAY. INCREASING WINDS ABOVE THE SFC BASED INVERSION WILL LEAD TO LLWS AT KIWD LATE TONIGHT INTO EARLY SUNDAY. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 314 PM EST SAT MAR 5 2016 AS THE PRES GRADIENT TIGHTENS TONIGHT BETWEEN HI PRES MOVING INTO THE MID ATLANTIC STATES AND A LO PRES CROSSING SCENTRAL CANADA... EXPECT LIGHT WINDS THIS EVENING TO BECOME SW AND INCREASE UP TO 25- 30 KTS ON SUN AFTERNOON. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE GUSTS TO 35 KTS OVER EASTERN LAKE SUP DURING THIS TIME. WINDS WILL THEN DIMINISH SUN NIGHT/MON UNDER A WEAKENING PRES GRADIENT. AS LOW PRES TRACKS FROM THE WESTERN PLAINS MON MORNING TO NORTHERN ONTARIO TUE...EXPECT S WINDS TO INCREASE UP TO 25 KTS AGAIN. THE ARRIVAL OF MOISTER AIR IN THIS FLOW OVER THE RELATIVELY CHILLY LAKE WATERS WILL CAUSE SOME FOG. AS THE COLD FRONT ASSOCIATED WITH THIS LO PRES PASSES OVER LAKE SUP ON LATE TUE INTO EARLY WED... WINDS WILL SHIFT TO THE WNW UP TO 20-25 KTS. THE ARRIVAL OF A HI PRES RIDGE WILL THEN CAUSE DIMINISHING WINDS LATER ON WED AND THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... GALE WARNING FROM 1 PM TO 10 PM EST SUNDAY FOR LMZ248-250. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...KF MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
300 PM EST SAT MAR 5 2016 .DISCUSSION... ACCUMULATING SNOW COMING TO AN END BY 00Z...AS 700 MB COLD POOL OF -14 TO -15 C EXITS SOUTHEAST MICHIGAN EARLY THIS EVENING AND ANTICYCLONIC FLOW BUILDS IN...WITH WARMING MID LEVELS AND LOWERING INVERSION HEIGHTS TONIGHT. UNCERTAINTY WITH TRAPPED LOW LEVEL MOISTURE/LOW CLOUDS AS SURFACE HIGH PRESSURE OF 1026 MB BUILDS INTO SOUTHEAST MICHIGAN...PROVIDING FAVORABLE BACKDROP FOR COLD (AROUND 10 DEGREES) MINS IF CLOUDS BREAK. THE RAP SOUNDINGS SUGGEST TO SKEW THE FORECAST ON CLOUDIER SIDE FOR MUCH OF THE NIGHT...WHICH WOULD KEEP MINS ELEVATED IN THE LOWER 20S/AROUND 20 DEGREES. HOWEVER...CLEARING TREND WORKING DOWN FROM NORTHERN LOWER MICHIGAN THIS AFTERNOON IS LOOKING FAIRLY AGRESSIVE...AND DO WANT TO GIVE WEIGHT TO THE 12Z EURO WHICH ALLOWS FOR CLEARING IN NORTH HALF OF CWA...ALLOWING MINS TO FALL INTO THE TEENS. IF CLEARING DOES EXTEND EVEN FARTHER SOUTH TONIGHT...COULD HAVE FOG DEVELOPMENT...BUT ELECTED TO LEAVE OUT OF THE FORECAST DUE TO THE LOW PROBABILITY OF OCCURRENCE AT THIS TIME. WITH UPPER LEVEL RIDGE AXIS ARRIVING TOMORROW...WARM ADVECTION REALLY KICKS...AS 850 MB TEMPS RISE INTO THE MID SINGLE NUMBERS LATE IN THE DAY...WITH 925 MB TEMPS PROGGED TO RISE ABOVE 0 C...SUPPORTIVE OF HIGHS IN THE LOWER 40S. ALTHOUGH...CONCERNS WITH LOW CLOUDS PERSISTS WITH THE VERY STEEP LOW LEVEL INVERSION IN PLACE. CONTINUED STRONG SOUTHWEST LOW LEVEL WARM ADVECTION SUNDAY NIGHT WITH SUFFICIENT PRESSURE GRADIENT/SURFACE WINDS TO MITIGATE FOG POTENTIAL...DESPITE SURFACE DEW PTS RISING INTO THE 30S. 12Z EURO/NAM BOTH INDICATING 925 MB TEMPS RISING JUST ABOVE 10 C ON MONDAY...SUGGESTIVE OF MAXES CLIMBING INTO THE LOWER 60S. HOWEVER...UNLIKE OUR PAST WARMUP`S IN FEBRUARY...WARM ADVECTION MID CLOUDS ARE EXPECTED TO BE A BIT THICKER/PERSISTENT...AND WILL TEMPER THE WARMUP A BIT AND KEEP MAXES IN THE 55 TO 60 DEGREE RANGE. ISENTROPIC ASCENT AND CONTINUED MOISTURE TRANSPORT COULD YIELD SOME LIGHT RAIN/DRIZZLE POSSIBLY DEVELOPING AS WELL...ESPECIALLY AS WE HEAD INTO MONDAY NIGHT. FROM TUESDAY ONWARD...MOISTURE PLUME OF PWAT 1+ INCHES WILL CREEP EASTWARD AHEAD OF LOWER TROPOSPHERIC FRONTAL BOUNDARY. THESE FEATURES SHOULD REMAIN FAR ENOUGH TO THE WEST TO ENSURE MAINLY DRY AND VERY MILD WEATHER ON TUESDAY BEFORE PRECIPITATION CHANCES INCREASE TUESDAY NIGHT. MODELS CONTINUE TO INDICATE THE BOUNDARY STALLING OVER LOWER MICHIGAN MIDWEEK...WITH A BACKDOOR SURFACE COLD FRONT WORKING THROUGH THE REGION LATER WEDNESDAY...WHICH WOULD KNOCK TEMPS DOWN BY ABOUT 10 DEGREES FOR THURSDAY. RAIN SHOWERS WILL CONTINUE TO BE LIKELY THROUGH THURSDAY FAVORING THE SOUTHERN HALF OF THE FORECAST AREA...AS DRIER AIR WILL FEED IN NORTH OF THE BOUNDARY. && .MARINE... HIGH PRESSURE MOVING ACROSS THE REGION WILL MAINTAIN LIGHT WINDS TONIGHT. WINDS THEN WILL STRENGTHEN OUT OF THE SOUTHWEST ON SUNDAY IN RESPONSE TO AN INCREASING GRADIENT IN THE WAKE OF THIS HIGH. WINDS WILL REACH 15 TO 20 KNOTS BY AFTERNOON OVER A GOOD PORTION OF LAKE HURON...PEAKING SUNDAY NIGHT AT 20 TO 25 KNOTS OVER THE OPEN WATERS. AT THIS TIME...GUSTS ARE EXPECTED TO REMAIN BELOW GALE FORCE...WITH WARMER AIR SURGING INTO THE AREA PROVIDING A HIGH DEGREE OF STABILITY OVER THE COLD LAKE WATERS. A MODERATE SOUTH TO SOUTHWEST WIND WILL CONTINUE THROUGH EARLY NEXT WEEK. && .AVIATION...ISSUED 1253 PM EST SAT MAR 5 2016 ONGOING WIDESPREAD LIGHT SNOW IN IFR CONDITIONS WILL GRADUALLY LIFT EASTWARD THROUGH THE LATE AFTERNOON/EARLY EVENING PERIOD. ADDITIONAL ACCUMULATION BELOW ONE INCH. EXISTING STRATUS WILL HOLD TIGHT THROUGH THE EVENING PERIOD...EASING INTO MVFR DURING THIS TIME. CLOUD TRENDS BECOME MUCH LESS CERTAIN BEYOND MIDNIGHT AS THE POTENTIAL DOES EXIST FOR DRIER AIR EXPANDING SOUTHWARD TO SUPPORT GREATER CLEARING POTENTIAL. A MIXED SIGNAL WITHIN THE MODEL GUIDANCE AND CURRENT SATELLITE TRENDS...AND WILL FAVOR A MORE PESSIMISTIC/CLOUDIER FORECAST UNTIL SHORT TERM TRENDS BECOME MORE DEFINITIVE. AN ELEMENT OF FOG A GREATER POSSIBILITY SHOULD A PERIOD OF CLEAR SKY EMERGE OVERNIGHT. FOR DTW...LIGHT SNOW IN IFR THROUGH 21Z...GRADUALLY IMPROVING CONDITIONS THEREAFTER INTO THE EVENING. ADDITIONAL ACCUMULATION LESS THAN ONE INCH. CLOUD TRENDS BECOME AN ISSUE BEYOND MIDNIGHT AS THE EXISTING STRATUS WORKS AGAINST A DRYING ENVIRONMENT. AT THIS TIME...IN FAVOR OF MAINTAINING A CEILING TONIGHT AND SUNDAY UNTIL TRENDS CAN BECOME MORE DEFINITIVE MOVING FORWARD. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CEILINGS AOB 5000 FEET THROUGH THIS EVENING. LOW OVERNIGHT AND SUNDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ DISCUSSION...SF/DT MARINE.......MR AVIATION.....MR YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1253 PM EST SAT MAR 5 2016 .AVIATION... ONGOING WIDESPREAD LIGHT SNOW IN IFR CONDITIONS WILL GRADUALLY LIFT EASTWARD THROUGH THE LATE AFTERNOON/EARLY EVENING PERIOD. ADDITIONAL ACCUMULATION BELOW ONE INCH. EXISTING STRATUS WILL HOLD TIGHT THROUGH THE EVENING PERIOD...EASING INTO MVFR DURING THIS TIME. CLOUD TRENDS BECOME MUCH LESS CERTAIN BEYOND MIDNIGHT AS THE POTENTIAL DOES EXIST FOR DRIER AIR EXPANDING SOUTHWARD TO SUPPORT GREATER CLEARING POTENTIAL. A MIXED SIGNAL WITHIN THE MODEL GUIDANCE AND CURRENT SATELLITE TRENDS...AND WILL FAVOR A MORE PESSIMISTIC/CLOUDIER FORECAST UNTIL SHORT TERM TRENDS BECOME MORE DEFINITIVE. AN ELEMENT OF FOG A GREATER POSSIBILITY SHOULD A PERIOD OF CLEAR SKY EMERGE OVERNIGHT. FOR DTW...LIGHT SNOW IN IFR THROUGH 21Z...GRADUALLY IMPROVING CONDITIONS THEREAFTER INTO THE EVENING. ADDITIONAL ACCUMULATION LESS THAN ONE INCH. CLOUD TRENDS BECOME AN ISSUE BEYOND MIDNIGHT AS THE EXISTING STRATUS WORKS AGAINST A DRYING ENVIRONMENT. AT THIS TIME...IN FAVOR OF MAINTAINING A CEILING TONIGHT AND SUNDAY UNTIL TRENDS CAN BECOME MORE DEFINITIVE MOVING FORWARD. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CEILINGS AOB 5000 FEET THROUGH THIS EVENING. LOW OVERNIGHT AND SUNDAY. && .PREV DISCUSSION...ISSUED 959 AM EST SAT MAR 5 2016 UPDATE... HAVE ALL BUT REMOVED FREEZING DRIZZLE MENTION...AS 700 MB COLD OF -14 TO -15 C SLOWLY TRACKS THROUGH SOUTHEAST MICHIGAN DURING THE REMINDER OF THE DAY SUPPORTING ALL SNOW...WITH RADAR TRENDS SUPPORTING MORE CONVECTIVE SNOW BANDS/HIGHER RATES...AND HAVE GONE AHEAD AND RAISED ACCUMULATIONS TO ACCOUNT FOR 2 INCH TOTALS ACROSS WASHTENAW/LENAWEE COUNTIES...AND WITH THE SLOW MOVING CONVERGENCE ZONE AND PROLONGED PERIOD THROUGH THE AFTERNOON HOURS...3 INCHES CAN`T BE RULED OUT. PREV DISCUSSION...ISSUED 826 AM EST SAT MAR 5 2016 UPDATE... QUICK UPDATE TO RAISE POPS AND CARRY MORE SNOW (VS FREEZING DRIZZLE BASED ON LATEST RADAR TRENDS)...AS MID LEVEL CIRCULATION ROTATING THROUGH CENTRAL LAKE MICHIGAN/SOUTHWEST LOWER MICHIGAN PROVIDES SUFFICIENT FORCING ON THE NORTHEAST FLANK TO SUPPORT SNOW SHOWERS...AS IR SHOWS CLOUD TOP COOLING AND SUFFICIENT ICE NUCLEI. THE WEAK LOW LEVEL CIRCULATION WILL SLOWLY TRACK SOUTHEAST...EXPECTED TO MOVE THROUGH LENAWEE COUNTY AND INTO NORTHWEST OHIO LATE THIS AFTERNOON. SHOULD BE ABLE TO GRIND OUT AT LEAST AN INCH OF SNOW ACCUMULATION ALONG AND WEST OF U.S. 23 UP TO ABOUT M-59. WILL HAVE TO WATCH OUT FOR LOCALIZED HIGHER AMOUNTS IF CONVECTIVE ELEMENTS ARE MORE VIGOROUS. PREV DISCUSSION...ISSUED 309 AM EST SAT MAR 5 2016 DISCUSSION... LIGHT SNOW OVERSPREAD MUCH OF SE MI OVERNIGHT. SFC OBSERVATIONS AND RADAR SUGGEST SOME LOCALS /PARTICULARLY SOUTH OF THE I-69 CORRIDOR/ HAVE BEEN EXPERIENCING INTERVALS OF FAIRLY GOOD SNOWFALL RATES. THIS SNOW IS OCCURRING WITHIN A REGION OF MID LEVEL ISENTROPIC ASCENT AHEAD OF AN UPPER SHORT WAVE NOW OVER WISCONSIN...AIDED BY A LEAD SHORT WAVE IMPULSE NOW ROTATING INTO SE MI. THE UPSTREAM MID LEVEL TROUGH WILL ROTATE INTO THE OHIO VALLEY BY AFTERNOON...WITH THE ASSOCIATED SFC LOW /OVER CNTRL WISCONSIN AS OF 07Z/ TRACKING INTO NRN INDIANA BY EARLY AFTERNOON. THE REGIONAL WATER VAPOR LOOP SHOWS THE AXIS OF DEEP LAYER MOISTURE ALREADY OVER SE MI...WITH MID LEVEL DRY AIR FAST MOVING INTO SW LOWER MI. THIS LOSS OF MID LEVEL MOISTURE IS LEADING TO AN ABRUPT END TO THE LIGHT SNOW OVER SW LOWER ATTM. MODEL RH PROGS AND SOUNDINGS /WITH SUPPORT FROM THE WATER VAPOR LOOP/ INDICATE THE MID LEVEL DRY AIR WILL OVERSPREAD SE MI BY 12Z. THE RESULTING BRIEF DURATION OF THE SNOW EARLY THIS MORNING WILL KEEP ACCUMS TO AN INCH OR LESS /WITH THE HIGHEST AMOUNTS SOUTH OF I-69/. DESPITE THE LOSS OF MID LEVEL MOISTURE...THERE WILL BE AN ADDITIONAL INFLUX OF LOW LEVEL MOISTURE /SUB 850MB/ DRIVEN INTO SE MI DURING THE MORNING. THIS WILL PROVIDE A GOOD SET UP FOR SOME FREEZING DRIZZLE. THIS AND THE AMOUNT OF FZDZ REPORTS ACROSS WISCONSIN SUPPORT ADDING AREAS OF FZDZ TO THE MORNING FORECAST. BY THE TIME THAT CONDITIONS BECOME OPTIMAL FOR FZDZ...SFC TEMPS SHOULD BE WARMING INTO THE LOWER 30S AND LIKELY ABOVE FREEZING BY NOON. THIS AND THE POTENTIAL SHORT DURATION OF ANY DRIZZLE WILL SUPPORT HOLDING OFF ON ANY TYPE OF WINTER WX ADVISORIES FOR THE TIME BEING. DEEP LAYER MOISTURE WILL ROTATE BACK INTO SE MI THIS AFTERNOON. WITH SOME STEEP MID LEVEL LAPSE RATES AND DIURNAL INSTABILITY...SNOW SHOWER ACTIVITY IS POSSIBLE. THE NAM AND HRRR SUGGEST SOME FGEN DEVELOPMENT ALONG THE MID TROPOSPHERIC FRONT...GENERALLY SOUTH OF THE M 59 CORRIDOR EARLY IN THE AFTERNOON. THIS WILL NOT ONLY WARRANT HIGHER POPS IN THESE LOCALS BUT ALSO SUGGEST SOME ADDITIONAL LIGHT AFTERNOON SNOW ACCUMS /POSSIBLY A HALF INCH/. SFC HIGH PRESSURE WILL EXPAND ACROSS SE TONIGHT AMIDST RISING MID LEVEL HEIGHTS IN THE WAKE OF THE DEPARTING UPPER TROUGH. LOW LEVEL ANTICYCLONIC FLOW AND DRY AIR ADVECTION SHOULD CLEAR THE LOW CLOUDS OUT LATE IN THE NIGHT...SUPPORTING A BRIEF PERIOD OF DECENT RADIATIONAL COOLING. IF THIS COOLING OCCURS A LITTLE EARLIER...LATER SHIFTS WILL HAVE TO CONSIDER ADDING FOG TO THE FORECAST. LONG WAVE RIDGE AMPLIFICATION ACROSS THE ERN US EARLY NEXT WEEK AND THE ESTABLISHMENT OF STRENGTHENING SOUTHWEST FLOW FROM THE SRN PLAINS INTO THE UPPER MIDWEST AND GREAT LAKES WILL SUPPORT A DRAMATIC WARM UP BEGINNING SUNDAY AND PERSISTING THROUGH AT LEAST TUESDAY. DESPITE THE SNOW COVER...THE STRONG LOW LEVEL WARM AIR ADVECTION WITHIN THE WELL MIXED SW FLOW WILL SUPPORT TEMPS ON THE HIGH END OF GUIDANCE /40S SUNDAY...50S MON...60S TUES/. CONSENSUS AMONG THE MEDIUM RANGE MODEL SUITE INDICATE BETTER RAINFALL CHANCES MID TO LATE WEEK AS MUCH DEEPER MOISTURE GETS ADVECTED INTO THE GREAT LAKES. A GOOD DEAL OF FCST UNCERTAINTY REVOLVES AROUND TIMING A BACK DOOR COLD FRONT THROUGH THE AREA NEXT WEEK. MODEL SOLUTIONS DIVERGE WITH RESPECT TO TIMING AND AMPLITUDE OF AN UPPER WAVE TRACKING ACROSS CANADA WHICH RESULTS IN A LARGE SPREAD IN TIMING THIS BACK DOOR COLD FRONT INTO SE MI. IT LOOKS AS THOUGH THIS FRONT WILL MOVE THROUGH SOMETIME IN THE WED TO THURS TIME FRAME AND WILL HAVE THE POTENTIAL TO BRING MUCH COOLER LAKE MODIFIED BOUNDARY LAYER AIR INTO THE AREA /WITH WARM MOIST SOUTHWEST FLOW ALOFT STILL PROVING PERIODIC CHANCES FOR RAIN SHOWERS/. MARINE... WINDS WILL REMAIN LIGHT TODAY...GENERALLY UNDER 10 KNOTS...AS LOW PRESSURE SLIDES FROM THE WESTERN GREAT LAKES INTO THE OHIO VALLEY TODAY...AND THEN A RIDGE OF HIGH PRESSURE SHIFTS INTO THE AREA TONIGHT. LOW PRESSURE TRACKING ACROSS HUDSON BAY AND ONTARIO SUNDAY INTO SUNDAY NIGHT WILL THEN PROVIDE A TIGHTER SURFACE PRESSURE GRADIENT OVER THE AREA...CAUSING WINDS TO INCREASE. THE STRONGEST WINDS LOOK TO OCCUR OVER THE OPEN WATERS OF LAKE HURON...WITH SPEEDS INTO THE 20 TO 25 KNOT RANGE. GUSTS SHOULD REMAIN BELOW GALE FORCE HOWEVER AS WARMER AIR SURGING INTO THE AREA WILL PROVIDE A HIGH DEGREE OF STABILITY OVER THE COLD LAKE WATERS. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....MR UPDATE.......SF DISCUSSION...SC MARINE.......HLO YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1241 PM EST SAT MAR 5 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 445 AM EST SAT MAR 5 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS A RIDGE OVER THE ROCKIES AND A TROF OVER ERN NAMERICA. SHORTWAVE THAT BROUGHT SNOW INTO UPPER MI OVER THE LAST 12HRS OR SO IS TRACKING SE THRU WI. THIS WILL BE THE FINAL SHORTWAVE TO DROP SE THRU THE AREA BEFORE A TRANSITION TO A WARM SPLIT FLOW PATTERN WITH ABOVE NORMAL HEIGHTS AND W TO SW FLOW ACROSS THE UPPER GREAT LAKES NEXT WEEK. RADAR TRENDS OVER THE LAST COUPLE OF HRS SHOW SNOW DIMINISHING OVER UPPER MI...AND UPSTREAM... KDLH RADAR SHOWS VERY LITTLE PCPN REMAINING. THERE WERE OBS AND REPORTS OF SOME -FZDZ EARLIER IN THE NIGHT OVER WRN UPPER MI AND NRN WI AS THE HEAVIER SNOW DEPARTED. RECENTLY...THERE ARE FEWER OBS SHOWING UNKNOWN PCPN...SO -FZDZ MAY BE DIMINISHING. WITH SHORTWAVE CONTINUING SE TODAY...DIMINISHING PCPN WILL END FROM NW TO SE. SOUTHERLY FLOW ON LAKE MI PERSISTS THRU MID TO LATE MORNING WHICH SHOULD HELP WEAKLY LAKE ENHANCED SNOW TO LINGER. THUS...HIGHEST POPS WILL PAINTED OVER THE E THIS MORNING WITH PERHAPS ANOTHER HALF INCH OR SO OF SNOW ACCUMULATION. TO THE W... WILL KEEP A MENTION OF -FZDZ/-SN MAINLY IN THE COUNTIES BORDERING WI FOR THE NEXT FEW HRS. SATELLITE IMAGERY SHOWS CLEARING NOT THAT FAR AWAY ACROSS NRN LAKE SUPERIOR. WITH HIGH PRES RIDGE BUILDING INTO THE UPPER GREAT LAKES THIS AFTN...LOW-LEVEL NORTHERLY WINDS AHEAD OF THE RIDGE WILL DIMINISH. THIS INCREASES THE UNCERTAINTY IN HOW MUCH CLEARING WILL OCCUR...ESPECIALLY SINCE UPSLOPE FLOW OFF THE LAKE UNDER A LOWERING INVERSION SHOULD GREATLY SLOW THE CLEARING PROCESS. KEWEENAW OBVIOUSLY HAS THE BEST CHC OF AT LEAST PARTIALLY CLEARING OUT TODAY GIVEN THE CLOSE PROXIMITY OF CLEAR SKIES ALREADY EARLY THIS MORNING. FOR NOW...FCST WILL SHOW A VERY GRADUAL DECREASE IN CLOUDS FROM THE N AND NW THIS AFTN INTO THIS EVENING. CLOUD FCST INTO TONIGHT REMAINS A BIT TRICKY. IF THE EXTENSIVE LOW CLOUDS ACROSS MN/WI PERSIST THRU THE DAY...THESE CLOUDS MAY MOVE BACK INTO THE AREA TONIGHT ONCE S TO SW FLOW DEVELOPS/INCREASES AFTER THE HIGH PRES RIDGE PASSES. OTHERWISE...PROVIDED MUCH OF TODAYS CLOUD COVER DEPARTS BY EVENING...THERE WILL BE AN OPPORTUNITY FOR TEMPS TO FALL QUICKLY THIS EVENING UNDER LIGHT/CALM WIND. LEANED FCST TO THE COLDER BIAS CORRECTED REGIONAL/GLOBAL CANADIAN MODELS DUE TO THEIR NORMAL SUPERIOR PERFORMANCE IN RADIATIONAL COOLING SITUATIONS. TRADITIONAL COLD SPOTS WILL FALL DOWN INTO THE MID TEENS IF SKIES ARE MOSTLY CLEAR THIS EVENING. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 349 AM EST SAT MAR 5 2016 ADVERTISED EARLY SPRING PREVIEW IS STILL ON TRACK FOR EARLY NEXT WEEK AND BEYOND. SUBSTANTIAL WARM ADVECTION KICKS IN ON SUNDAY. PRESSURE GRADIENT WILL TIGHTEN SIGNIFICANTLY BETWEEN SURFACE LOW/SHORTWAVE MOVING THROUGH NORTHERN ONTARIO AND HIGH PRESSURE ALONG THE EAST COAST. 85H TEMPS CLIMB INTO THE PLUS 5 TO 8C RANGE. EVEN WITH THE STABLE THERMAL PROFILE 92H WINDS ARE FORECAST UP TO 40 KNOTS SO EXPECT WINDS TO BE PRETTY GUSTY. NAM REMAINS CONSISTENT...AND TO A LESSER EXTENT THE GFS...IN SHOWING ENOUGH MOISTENING THROUGH THE DAY THAT THERE MAY EVEN BE SOME LIGHT PRECIPITATION OVER EASTERN AREAS BY LATE IN THE DAY. WILL INTRODUCE SOME SLIGHT CHANCE POPS ACROSS THE EAST FOR SOME LIGHT RAIN/DRIZZLE. TEMPS ON SUNDAY WILL CLIMB INTO THE 40S WEST WHILE LAKE MICHIGAN COOLING WITH THE STRONG SOUTHWESTERLY WINDS WILL KEEP TEMPS IN THE UPPER 30S ACROSS THE EAST. THE BEST CHANCES FOR ANY WIDESPREAD PRECIPITATION...ALBEIT RELATIVELY LIGHT...WILL OCCUR DURING THE MONDAY THROUGH TUESDAY NIGHT TIME PERIOD. WHILE TEMPERATURES WILL BE WELL ABOVE NORMAL...IT WILL PROBABLY BE PRETTY GLOOMY DURING THIS PERIOD. CONTINUED WARM ADVECTION...DEWPOINTS CLIMBING INTO THE 30S AND 40S...AND A MELTING SNOWPACK WILL YIELD PLENTY OF LOW CLOUDS...PATCHY FOG...AND DRIZZLE. SHEARING OUT SHORTWAVE EJECTING WEST OF THE AREA ON TUESDAY WITH SURFACE LOW PASSING NORTHWEST OF LAKE SUPERIOR WILL BRING THE BEST CHANCE OF RAIN ON TUESDAY. WITH DYNAMICAL FORCING ON THE WANE AND LINGERING MID LEVEL DRY AIR ANY PRECIPITATION WILL BE PRETTY LIGHT. AS TRAILING COLD FRONT CROSSES THE AREA LATE TUESDAY AND WITH FAIRLY STEEP MID LEVEL LAPSE RATES STILL CANNOT RULE THE POSSIBILITY OF A THUNDERSTORM ALONG THE FRONT. HOWEVER...CAPPING MAY REMAIN TOO STRONG TO ALLOW ANY DEEP CONVECTION. DESPITE THE CLOUDS TEMPERATURES WILL APPROACH 50 FOR MANY ON MONDAY AND INTO THE 50S ON TUESDAY AWAY FROM THE COOLING INFLUENCES OF THE LAKES...ESPECIALLY LAKE MICHIGAN. DRIER AIR ALONG WITH SOME COOLING BEHIND THE FRONT WILL ALLOW PRECIPITATION TO COME TO AN END TUESDAY NIGHT. FORECAST LOOKS DRY DURING THE WEDNESDAY THROUGH FRIDAY PERIOD. AFTER A BRIEF COOL DOWN WEDNESDAY...ALTHOUGH STILL ABOVE NORMAL...MILD PACIFIC AIR WILL RETURN FOR LATE IN THE WEEK WITH DAYTIME TEMPS ONCE AGAIN APPROACHING 50 FOR MANY BY LATE IN THE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1241 PM EST SAT MAR 5 2016 VFR CEILINGS AND VIS WILL BE THE RULE THROUGH THE NEXT 24HRS. THE ONLY HOLDOUT WILL BE INITIALLY THIS AFTERNOON AS THE END OF LAKE ENHANCED MAINLY MVFR CLOUD COVER SINKS ACROSS UPPER MI /ENDING LAST AT IWD AND SAW BY 23Z/. HIGH PRESSURE OVER WESTERN LAKE SUPERIOR...STRETCHING FROM S MN/IA WILL BRIEFLY TAKE HOLD OF UPPER MI FOR THE REST OF THE AFTERNOON HOURS...BEFORE QUICKLY EXITING ACROSS LOWER MI THIS EVENING. A STRONG PRESSURE GRADIENT WILL SET UP ACROSS THE AREA OVERNIGHT AND REMAIN THROUGH THE DAY SUNDAY. THIS WILL BE THE RESULT OF THE EXITING INTO THE MID ATLANTIC STATES...AND LOW PRESSURE TRACKING ACROSS S CANADA THIS EVENING TO SLIDE ACROSS S MANITOBA AND ND BY DAYBREAK SUNDAY. INCREASING WINDS ABOVE THE SFC BASED INVERSION WILL LEAD TO LLWS AT KIWD LATE TONIGHT INTO EARLY SUNDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 445 AM EST SAT MAR 5 2016 EXPECT LIGHT WINDS...MOSTLY UNDER 15KT TO BE THE RULE ACROSS LAKE SUPERIOR TODAY UNDER A WEAK PRES GRADIENT WITH HIGH PRES RIDGE ARRIVING IN THE AFTN. PRES GRADIENT WILL THEN TIGHTENT TONIGHT AND SUN AS THE RIDGE SHIFTS TO THE E COAST AND A LOW PRES MOVES ACROSS SCNTRL CANADA. S TO SW WINDS WILL RAMP UP TO AS HIGH AS 30KT LATE TONIGHT AND SUN. NOT OUT OF THE QUESTION THAT A FEW GALE FORCE GUSTS COULD OCCUR OVER EASTERN LAKE SUPERIOR SUN. WINDS WILL THEN DIMINISH SUN NIGHT/MON UNDER A WEAKENING PRES GRADIENT. AS LOW PRES TRACKS FROM THE WESTERN PLAINS MON MORNING TO NORTHERN ONTARIO TUE AND QUEBEC WED...WINDS WILL AGAIN INCREASE TO 15-25KT AT TIMES TUE/WED. SOME FOG MAY FORM OVER THE CHILLY WATERS MON NIGHT/TUE AS MOISTER AIR MOVES INTO THE UPPER LAKES AHEAD OF THE LOW PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...MZ AVIATION...KF MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1154 AM CST SAT MAR 5 2016 .UPDATE... ISSUED AT 1153 AM CST SAT MAR 5 2016 UPDATE TO THE FORECAST WILL ONLY HAVE MINOR ADJUSTMENTS WITH MOST ELEMENTS ON TRACK. THE LATEST HRRR AND RAP13 SUGGEST DEWPOINTS COULD STILL BE A COUPLE DEGREES TOO HIGH IN THE SOUTHWEST...SO ADJUSTED THEM ACCORDINGLY. THE STRATUS HAS FINALLY EXITED THE EAST...THOUGH THERE ARE SOME HIGH CLOUDS SPILLING INTO WESTERN NORTH DAKOTA FROM MONTANA. WILL CARRY SCATTERED CLOUDS...ESPECIALLY WEST THROUGH THE AFTERNOON. UPDATE ISSUED AT 931 AM CST SAT MAR 5 2016 NO MAJOR CHANGES TO THE FORECAST WERE WARRANTED SO FAR THIS MORNING. MAIN CHANGE WAS TO SLOW DOWN THE CLEARING FROM JAMESTOWN EASTWARD WHERE THE CLOUDS HAVE BEEN A LITTLE SLOW TO MOVE OUT. THE LATEST SHORT TERM MODELS STILL SHOW THE CLOUDS EXITING...WITH ONLY SCATTERED HIGH CLOUDS LATER THIS AFTERNOON. UPDATE ISSUED AT 646 AM CST SAT MAR 5 2016 NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE CYCLE...BUT WE DID DELAY THE EXIT OF LOW CLOUDS /STRATUS/ IN THE SOUTHERN JAMES RIVER VALLEY A BIT UNTIL MID MORNING BASED ON SATELLITE AND HRRR TRENDS. OTHERWISE...THE 12 UTC BISMARCK SOUNDING REVEALED PLENTY OF MID-LEVEL WARMING AND DRYING SINCE LAST EVENING...SUPPORTING THE GOING WARM FORECAST FOR TODAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 344 AM CST SAT MAR 5 2016 WARMER...BREEZY...AND DRY CONDITIONS HIGHLIGHT THE SHORT TERM PERIOD. SOUTHERLY WINDS/WARM AIR ADVECTION DEVELOP TODAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A MINOR COLD FRONT PASSES THROUGH SATURDAY NIGHT. THE LATEST WATER VAPOR AND IR IMAGERY LOOP INDICATE MID/UPPER LEVEL RIDGING OVER THE NORTHERN ROCKIES THIS MORNING WITH SCATTERED HIGH CLOUDS RIDING ATOP THE RIDGE INTO WESTERN NORTH DAKOTA. FOG/STRATUS IMAGERY LOOP CONTINUES TO SHOW AN AREA OF LOW CLOUDS IN THE JAMES RIVER VALLEY. THIS IS FORECAST TO EXIT BY 12Z SATURDAY. THE TREND WILL BE FOR THE UPPER RIDGE TO SHIFT EAST AND GRADUALLY FLATTEN/BECOME BROADER THROUGH TONIGHT...AS A PAIR OF SHORTWAVES PUSH INTO THE RIDGE. THE FIRST SHORTWAVE IS BEST DEFINED AT 700MB AND CURRENTLY IS LOCATED IN SOUTH CENTRAL MONTANA. THIS WILL STEADILY MOVE INTO SOUTH CENTRAL NORTH DAKOTA BY 00Z SUNDAY. NOT EXPECTING ANYTHING SIGNIFICANT AS THERE IS NO SURFACE LOW REFLECTION. THIS SHORTWAVE WILL MAINLY SERVE TO FLATTEN THE OVERALL HEIGHT FIELD/RIDGE AXIS AS IT PROPAGATES THROUGH. THE SECOND SHORTWAVE NOW INTO SOUTHWEST BRITISH COLUMBIA WILL SLIDE ACROSS SOUTHERN CANADA INDUCING A SURFACE LOW/COLD FRONT IN SOUTHERN ALBERTA THIS AFTERNOON. IT WILL THEN MOVE EAST AND GRAZE NORTH DAKOTA SATURDAY NIGHT WITH A WIND SHIFT AND WEAK COLD AIR ADVECTION. FOR TODAY...THE CANOPY OF THE 1000-500MB THICKNESS RIDGE HOVERS OVER THE SOUTHWEST...RESULTING IN THE WARMEST/DRIEST AIR TO RESIDE HERE. AFTERNOON HIGHS WILL CLIMB INTO THE MID/UPPER 60S SOUTHWEST. ELSEWHERE EXPECT HIGHS IN THE 50S CENTRAL TO 40S FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY. UTILIZED A 50/50 COMBINATION BLEND OF THE HRRR EXPERIMENTAL 2M HOURLY RH FIELD AND OFFICIAL GRIDDED FORECAST TO YIELD MINIMUM RELATIVE HUMIDITIES IN THE 15 TO 20 PERCENT RANGE SOUTHWEST. THIS SEEMS LOGICAL GIVEN UPSTREAM FLOW AND RELATED AIRMASS FROM FRIDAY HAVING ADVECTED IN FROM WYOMING. THE HRRR RH FIELD VERIFIED WELL IN NORTH DAKOTA AS WELL AS UPSTREAM IN THE LAST 24HR. WINDS TODAY WILL BE WEAKEST IN THE FAR SOUTHWEST WHERE AFTERNOON RELATIVE HUMIDITIES WILL BE LOWEST. WINDS WILL STEADILY INCREASE INTO THE BREEZY CATEGORY (15-25MPH) FOR CENTRAL NORTH DAKOTA THIS AFTERNOON. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 344 AM CST SAT MAR 5 2016 ABOVE-NORMAL TEMPERATURES AND MAINLY DRY WEATHER WILL PREVAIL FOR THE NEXT WEEK. ON SUNDAY...DAILY RECORD HIGHS MAY FALL GIVEN 850-MB TEMPERATURES IN THE 97.5 TO 99TH PERCENTILE FOR THIS TIME OF THE YEAR...NEARLY FULL SUNSHINE...DRY SOILS...AND DORMANT VEGETATION...ALL OF WHICH WILL SUPPORT EFFICIENT HEATING. WE ARE STILL CALLING FOR HIGHS IN THE 60S F IN MOST AREAS AND A FEW 70 F READINGS ARE LIKELY ACROSS SOUTHWEST AND SOUTH CENTRAL ND. MIXING IS FORECAST TO BE SOMEWHAT MORE SHALLOW THAN ON SATURDAY BASED ON 00 UTC MODEL SOUNDINGS AND THAT RAISES A BIT OF CONCERN FOR WARMING...BUT MORE THAN LIKELY THAT WILL JUST ENSURE WINDS WILL STAY RELATIVELY LIGHT. SUNDAY IS APT TO BE A TRULY STELLAR EARLY MARCH DAY. THEREAFTER...A PACIFIC COLD FRONT WILL CROSS THE AREA MONDAY AS A WEAK SHORTWAVE TROUGH EJECTS ACROSS THE REGION OUT OF A SPLITTING TROUGH THAT WILL KEEP ITS CORE WELL SOUTH IN TX AND MEXICO. WE DO HAVE A LOW-GRADE SHOWER CHANCE IN THE FORECAST BEHIND THE FRONT MONDAY THROUGH EARLY TUESDAY. PROGRESSIVE...QUASI-ZONAL FLOW WILL THEN OCCUR IN THE NORTHERN STREAM THE MIDDLE PART OF THE WEEK AND THAT WILL YIELD MAINLY DRY WEATHER. THE 00 UTC GFS AND ECMWF BOTH SUGGEST RIDGING REBUILDING AGAIN BY LATE WEEK....WITH THE 00 UTC NAEFS EVEN CALLING FOR 850-MB TEMPERATURE ANOMALIES IN THE 90TH PERCENTILE BY FRIDAY. THAT IS A SIGNIFICANT SIGNAL IN A LONG-LEAD ENSEMBLE FORECAST...SUGGESTING HIGHS COULD ONCE AGAIN END UP WELL INTO THE 60S F /WARMER THAN OUR CURRENT FORECAST/ BY LATE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1153 AM CST SAT MAR 5 2016 VFR CONDITIONS ARE FORECAST TO PREVAIL THROUGH THE 18Z TAF PERIOD. THERE WILL BE SOME INCREASE IN HIGH LEVEL CLOUDS...BUT THE MAIN STORY WILL BE WINDS. BREEZY SOUTH TO SOUTHEAST WINDS THIS AFTERNOON ARE EXPECTED...BUT THEY SHOULD DIMINISH THIS EVENING. && .FIRE WEATHER... ISSUED AT 1153 AM CST SAT MAR 5 2016 DESPITE MINIMUM RELATIVE HUMIDITIES IN THE 15 TO 20 PERCENT RANGE OVER SOUTHWEST NORTH DAKOTA THIS AFTERNOON...WINDS WILL NOT BE STRONG ENOUGH FOR CRITICAL FIRE WEATHER CRITERIA TO BE MET. SUSTAINED SOUTHERLY WINDS WILL WEAKEN THROUGH THE AFTERNOON TO BETWEEN 10 AND 15 MPH...JUST AS RELATIVE HUMIDITIES REACH THEIR MINIMUM. WILL CONTINUE TO MONITOR...BUT CURRENTLY DO NOT PLAN TO ISSUE ANY HIGHLIGHTS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CK SHORT TERM...KS LONG TERM...CJS AVIATION...CK FIRE WEATHER...CK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
214 PM PST SAT MAR 5 2016 .SYNOPSIS...A FRONT WILL SPREAD RAIN ACROSS THE REGION THIS AFTERNOON AND EVENING AND PRODUCE A BRIEF BURST OF GUSTY WINDS LATE TONIGHT. SNOW LEVELS WILL FALL TO BELOW THE CASCADE PASSES LATE TONIGHT AND SUNDAY. AN UPPER LEVEL TROUGH WILL CONTINUE SHOWERS FOR SUNDAY. A WEAKER FRONT WILL BRING ADDITIONAL RAIN AND CASCADE SNOW SUNDAY NIGHT THROUGH MONDAY MORNING. SHOWERS WILL DECREASE MONDAY NIGHT FOR A BRIEF BREAK IN WEATHER TUESDAY MORNING. MORE WET WEATHER IS ON TAP FOR TUESDAY THROUGH THURSDAY. && .SHORT TERM...THERE IS A COMPLEX WEATHER PATTERN OFFSHORE WITH WATER VAPOR IMAGERY SHOWING THREE DISTINCT BOUNDARIES STEMMING FROM WHAT APPEARS TO BE A TRIPLE POINT LOW OFFSHORE THE OREGON/CALIFORNIA BORDER. THE LOW IS LESS IDENTIFIABLE ON VISIBLE OR INFRARED IMAGERY. LIGHT RAIN ALONG ONE OF THE BOUNDARIES BEGAN SPREADING INTO THE SOUTHERN AND CENTRAL WILLAMETTE VALLEY EARLY THIS AFTERNOON. RADAR IMAGERY SHOWS A BATCH OF HEAVIER RAIN OVER SW OREGON QUICKLY MOVING NORTHWARD. THIS MORE PERSISTENT RAIN WILL MOVE FROM SOUTH TO NORTH ACROSS NW OREGON AND SW WASHINGTON LATER THIS AFTERNOON THROUGH TONIGHT. EXPECT 0.75 TO 1.50 INCHES OF RAIN FOR THE COAST...COAST RANGE...AND CASCADES THROUGH EARLY SUNDAY MORNING...AND 0.40 TO 0.6 INCH FOR THE INTERIOR VALLEYS. THE LOW WILL MOVE NORTHWARD OFFSHORE THE OREGON COAST THIS AFTERNOON AND EVENING AND OFF OF THE WASHINGTON COAST TONIGHT...STAYING JUST WEST OF 130W. THE SURFACE PRESSURE GRADIENT WILL TIGHTEN AS THE LOW MOVES BY THE AREA...AND EXPECT A BRIEF BURST OF STRONG WINDS FOR THE BEACHES AND HEADLANDS...AND SOME GUSTS TO AROUND 30 OR POSSIBLY 35 MPH FOR THE WILLAMETTE VALLEY. THE FRONT WILL MOVE OUT OF THE AREA AROUND AROUND MIDNIGHT TONIGHT...BUT SHOWERS WILL PERSIST THROUGH SUNDAY MORNING. SNOW LEVELS WILL LOWER BEHIND THE FRONT AND SHOULD FALL TO NEAR THE CASCADE PASSES...3500 TO 4000 FEET BY SUNRISE SUNDAY. THE ATMOSPHERE WILL REMAIN UNSTABLE SUNDAY AS THE PARENT UPPER TROUGH BECOMES NEGATIVELY-TILTED AND THE TROUGH AXIS MOVES OVER THE REGION. THIS WILL FAVOR SHOWERS EVEN THOUGH THE AREA WILL BE BETWEEN SYSTEMS. EXPECT AN ADDITIONAL 0.15 TO 0.4 INCH OF RAIN SUNDAY MORNING THROUGH SUNDAY AFTERNOON WITH 1 TO 3 INCHES OF SNOW FOR THE CASCADES. THERE MAY BE ENOUGH INSTABILITY FOR SOME ISOLATED THUNDERSTORMS TO SPROUT OVER THE REGION. THE NEXT SHORT WAVE WILL APPROACH FROM THE SOUTHWEST SUNDAY AFTERNOON AND POSSIBLY FORM A 990MB SURFACE LOW OFFSHORE OF SOUTHERN OREGON SUNDAY AFTERNOON. THIS LOW IS WEAKER AND FURTHER SOUTH THAN THE PREVIOUS FEW LOWS...AND DO NOT EXPECT AS MUCH WIND. THE FRONT WILL ALSO BE WEAKER WITH LESS AVAILABLE MOISTURE. SNOW LEVELS WILL REMAIN AT OR JUST BELOW CASCADE PASSES. EXPECT AN ADDITIONAL 0.25 TO 0.60 INCH OF RAIN SUNDAY EVENING THROUGH EARLY MONDAY MORNING WITH 1 TO 3 INCHES OF NEW SNOW IN THE CASCADES. AN UPPER TROUGH WILL MOVE OVER THE REGION MONDAY CONTINUING SHOWERS AND A SLIGHT THREAT FOR THUNDERSTORMS. SHOWERS WILL DECREASE LATE MONDAY NIGHT FOR A BRIEF BREAK IN RAIN EARLY TUESDAY. TJ .LONG TERM...TUESDAY NIGHT THROUGH SATURDAY... A RATHER STRONG AND MOISTURE LADEN SYSTEM WILL MOVE INTO THE REGION WEDNESDAY AND THURSDAY. WEATHER MODELS INDICATE THIS IS AN ATMOSPHERIC RIVER SETUP WITH THE FRONT TAPPING INTO A MOISTURE PLUME OF 1.1 T0 1.4 INCHES OF PRECIPITABLE WATER. INTEGRATIVE VAPOR TRANSPORT SHOWS THE BEST CHANCE FOR HEAVY RAIN WILL BE ACROSS SW OREGON AND NO CAL...BUT NW OREGON AND SW WASHINGTON WILL STILL GET A DECENT SOAKING. WILL NEED TO MONITOR RIVER FORECASTS CLOSELY AS WE GET INTO THE MIDDLE OF NEXT WEEK. TW && .AVIATION... VFR ACROSS MOST OF THE REGION EARLY THIS AFTERNOON...BUT RAIN ALREADY OCCURRING ALONG THE COAST BETWEEN KONP AND KBOK WITH AREAS OF MVFR. COASTAL FLIGHT CONDITIONS WILL LOWER INTO PREDOMINANT MVFR TO IFR EARLY EVENING. COLD FRONT EXPECTED TO MOVE ACROSS THE COASTAL AREAS AROUND 04Z. IMPROVEMENT TO AN MVFR TO VFR MIX AFTER 06Z. INLAND AREAS TO REMAIN MAINLY VFR THROUGH 00Z THEN SHOW A MIX OF MVFR AND LOW-END VFR 00Z TO 12Z SUN. SW-W WIND 30-40 KT AT 5000 FT MSL TONIGHT THROUGH SUN MORNING WILL RESULT IN MOUNTAIN OBSCUREMENT AND MVFR OR WORSE CONDITIONS FOR THE HIGHER TERRAIN. EXPECT WIND GUSTS UP TO 50 KT ALONG THE COASTAL HEADLANDS AND 25 TO 35 KT OVER THE INTERIOR VALLEYS 02Z TO 10Z SUN. HAVE INCLUDED LLWS FOR KAST JUST BEFORE FRONTAL PASSAGE WITH SE SURFACE WIND 10-15 KT AND S WIND 30-40 KT AT FL020. KPDX AND APPROACHES...VFR THROUGH EARLY EVENING. RAIN RETURNS AROUND 00Z SUN...BUT EAST SURFACE COMPONENT SHOULD MAINTAIN VFR CONDITIONS. MVFR LIKELY AFTER 06Z SUN...BUT IMPROVING TO VFR BY 12Z. E TO SE SURFACE WIND SWITCHES TO S TO SW AROUND 06Z...WITH GUSTS UP TO 30 KT. WEISHAAR && .MARINE...NEXT FRONTAL SYSTEM TAKING SHAPE INSIDE 130W WITH BUOY 002 REPORTING SURFACE PRES OF 981.6 MB AT 20Z. WIND HAS BECOME MORE SE AHEAD OF THIS DEVELOPING SYSTEM. THE 14Z RUC AND 12Z NAM NOT QUITE AS ROBUST WITH WIND SPEEDS LATE THIS AFTERNOON THROUGH TONIGHT. 12Z NAM AND GFS SHOW 30-35 KT BOUNDARY LAYER WIND SPEEDS 06Z SUN. NAM ALSO INDICATED JUST 35 KT AT 975 MB. WILL MAINTAIN SOLID GALES WITH PEAK GUSTS UP TO 45 KT. STRONGEST SUSTAINED WIND LOOKS TO BE FROM 02Z TO 08Z SUN. MODELS SHOW ANOTHER SURFACE LOW DEVELOPING OVER THE SRN OREGON WATERS SUN AFTERNOON. THE 12Z NAM IS FURTHER N WITH THIS SECONDARY LOW...BRINGING IT INLAND NEAR NEWPORT 06Z MON. GFS SHOWS THE ENERGY FURTHER S...BETWEEN NORTH BEND AND BROOKINGS. SHOULD THE NAM VERIFY...MAY NEED TO GO WITH GALES FOR PZZ255 SUN EVENING. CONDITIONS SETTLE DOWN A BIT LATE SUN NIGHT THROUGH MON NIGHT. THE NEXT SYSTEM MOVES INTO THE WATERS TUE. MODELS SEEMS TO FOCUS THE MAIN ENERGY ACROSS THE CENTRAL AND S OREGON WATERS. EAST WIND COMPONENT TUE WILL KEEP THE STRONGEST WIND SPEEDS FURTHER OFFSHORE AND INHIBIT THE POTENTIAL FOR COASTAL JET DEVELOPMENT. HAVE INDICATED GALE FORCE WIND SPEEDS OVER THE OUTER WATERS TUE. MODELS SHOW A COUPLE OF REINFORCING SURFACE LOWS TRAVELING ALONG THE FRONTAL BOUNDARY TUE NIGHT THROUGH WED EVENING WITH STORM FORCE GUSTS POSSIBLE SOUTH OF CASCADE HEAD WED AND WED EVENING. ACTIVE PATTERN CONTINUES INTO NEXT WEEKEND. SEAS HAVE SETTLED TO 10 TO 12 FT EARLY THIS AFTERNOON...BUT WILL RAMP UP AGAIN TONIGHT. COMBINED SEAS LIKELY TO GET CLOSE TO 20 FT 12Z TO 18Z SUN...WITH A RATHER LARGE WIND-WAVE COMPONENT. SEAS HOLD IN THE MID TO UPPER TEENS SUN AFTERNOON THROUGH MON MORNING. WAVE HEIGHTS GET CLOSE TO 2O FT AGAIN LATE TUE NIGHT AND WED...ESPECIALLY OVER THE SRN WATERS. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM PST SUNDAY FOR CENTRAL OREGON COAST-NORTH OREGON COAST. WA...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM PST SUNDAY FOR SOUTH WASHINGTON COAST. PZ...GALE WARNING FROM 4 PM THIS AFTERNOON TO NOON PST SUNDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM PST SUNDAY. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
542 PM EST SAT MAR 5 2016 .SYNOPSIS... A WEAK CLIPPER TYPE LOW WILL BRING A BIT OF LIGHT SNOW OR FLURRIES TO THE AREA TONIGHT. A LARGE RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN HALF OF THE CONTINENT BEGINNING SUNDAY AND LASTING INTO THE UPCOMING WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... EVENING WATER VAPOR LOOP SHOWING A POTENT-LOOKING SHORTWAVE DIVING FROM THE OHIO VALL INTO THE S APPALACHIANS. WEAK FORCING ON THE NORTHERN PERIPHERY OF THIS FEATURE WILL COME THRU CENTRAL PA OVERNIGHT...LIKELY PRODUCING NO MORE THAN SOME SPOTTY LGT SNOW OR FLURRIES. A BLEND OF 12Z ENSEMBLE QPF AND MORE RECENT HRRR/NAM/GFS OUTPUT SUPPORT ACCUMS OF LESS THAN AN INCH...WITH SOME PLACES LIKELY SEEING NO ACCUM AT ALL. SREF AND LATEST HRRR SUGGEST THE BACK EDGE OF THE LGT SNOW WILL BE EXITING THE SE COUNTIES ARND DAWN. OVERNIGHT LOWS AVERAGING IN THE 30S WILL BE A COUPLE OF DEGREES EITHER SIDE OF NORMAL. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... HEIGHTS ALOFT WILL START REBOUNDING RAPIDLY SUNDAY WHICH WILL LEAD TO IMPROVING SKIES AS DRY AIR WORKS IN FROM THE NW. HIGHS FROM AROUND 40 IN THE NORTH TO AROUND 50 IN THE SOUTH WILL BE THE BEGINNING OF THE MUCH ANTICIPATED BIG WARM UP THAT HAS BEEN ADVERTISED FOR THE LAST SEVERAL DAYS. && .LONG TERM /MONDAY THROUGH SATURDAY/... BROAD CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP DURING THE FIRST HALF OF THE UPCOMING WEEK...AS AN ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 12Z ECENS. TEMPS WILL TAKE A RUN AT 70F BY WED OVR SOUTHERN PA. MODELS ARE IN BETTER AGREEMENT ON BRINGING A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF THROUGH PA BY MIDWEEK...AS HIGH PRESSURE TRACKING EASTWARD ACROSS CANADA WILL NUDGE THE FRONT SOUTHWARD AND PIVOT IT FROM MORE OF A N-S ORIENTATION TO A W-E DIRECTION. THIS COULD BRING THE NEXT BEST CHANCE FOR PRECIPITATION AS WEAK WAVES COULD RIPPLE TOWARD PA ALONG THE PORTION OF THE /WARM/ FRONT OVER THE OHIO VALLEY. GIVEN THE STRONG WAA IT LOOKS TO BE ALL RAIN...WITH PRECIP BRACKETED BETWEEN LATE IN THE DAY WED AND FRI. THE GFS IS MORE AGGRESSIVE WITH ONSET OF PRECIP AND QPF AMOUNTS THAN THE ECMWF...BUT EITHER WAY IT LOOKS TO BE A SHOWERY END TO THE WEEK AND TEMPS GRADUALLY COOL BACK DOWN BUT REMAIN ABOVE NORMAL. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... 21Z TAFS SENT. MINOR ADJUSTMENTS MADE. BANDS OF SNOW TO THE WEST ABOUT ON TRACK. EARLIER DISCUSSION BELOW. MVFR OVER THE LAURELS...VFR ELSEWHERE WILL CONTINUE INTO THE LATE AFTERNOON HOURS BEFORE A STORM SYSTEM BRINGS AREAS OF LIGHT SNOW OR RAIN AND MORE WIDESPREAD REDUCED CONDITIONS BY LATE AFTERNOON INTO THE OVERNIGHT. CONFIDENCE IN IFR IS LOW DUE TO THE DISORGANIZED NATURE OF THE PRECIPITATION ASSOCIATED WITH THE WEAK-SPRAWLING LOW SLIDING SOUTH OF THE REGION. BEST CHANCE WOULD SEEM TO BE OVER THE HIGHER ELEVATIONS OF THE WEST IN NORTH...AND ONLY INTERMITTENTLY AS AREAS OF LIGHT SNOW SLIDE EAST THIS EVENING INTO THE OVERNIGHT. A MORE WIDESPREAD AREA OF MVFR CEILINGS IS LIKELY AFTER DARK INTO EARLY SUNDAY AS THE STRONGEST PART OF THE SHORTWAVE ALOFT MOVES THROUGH THE FLYING AREA WITH AREAS OF LIGHT SNOW POSSIBLY BRINGING BRIEF REDUCTIONS IN VISIBILITY INTO THE 1-3 MILE RANGE. EARLY MVFR CONDITIONS WILL STEADILY IMPROVE SUNDAY MORNING WITH ALL TERMINALS EXPECTED TO BE VFR BY MID MORNING OR MID DAY. OUTLOOK...SUNDAY-WEDNESDAY MON-TUE...VFR/NO SIG WX. WED...LOW CIGS/RAIN POSSIBLE NORTHWEST AS A COLD FRONT SAGS INTO THE AIRSPACE. THU...WIDESPREAD MVFR/IFR WITH RAIN SHOWERS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD/LA CORTE NEAR TERM...FITZGERALD/LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
446 PM EST SAT MAR 5 2016 .SYNOPSIS... A WEAK CLIPPER TYPE LOW WILL BRING THE CHANCE FOR LIGHT RAIN OR SNOW LATER TODAY INTO SUNDAY MORNING. A LARGE RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN HALF OF THE CONTINENT DURING THE UPCOMING WEEK BRINGING MUCH ABOVE NORMAL TEMPERATURES STARTING MONDAY...AND LASTING THROUGH AT LEAST MID WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... THE REGION IS CLOUDY AS OF MID DAY WITH TEMPERATURES GENERALLY IN THE 30S. DEWPOINTS RANGE FROM THE SINGLE DIGITS OVER EASTERN ZONES TO THE LOW 20S OVER THE SOUTHWEST. THIS DRY AIR IN PLACE IS DOING A FINE JOB IN KILLING WHAT LITTLE LIGHT PRECIP HAS BEEN MOVING INTO THE REGION WITH ONLY THE OBSERVING SITES OF THE SOUTHWEST REPORTING SOME INTERMITTENT LIGHT SNOW. A SPRAWLING AND WEAK LOW PRESSURE AREA IS DROPPING THROUGH THE LOWER LAKES TOWARD WEST VIRGINIA. THE PRECIPITATION SHIELD EVEN BACK INTO THE LOWER LAKES/OHIO VALLEY IS VERY DISORGANIZED...LEADING TO A FORECAST WHERE THE POPS MAY BE HIGH BUT THE QPF IS LOW. THE HRRR AND WRF-NMM SUGGEST THE BEST CHANCE OF LIGHT PRECIP WILL BE FROM ABOUT 21Z/4PM THROUGH ABOUT 09Z/4AM...WITH THE PERIOD FROM ABOUT 03-06Z HAVING THE MOST OVERALL COVERAGE OF ACTUAL PRECIP IN PROGRESS. IN GENERAL NO MORE THAN A TENTH OF AN INCH OF QPF IS EXPECTED IN MOST AREAS. WITH OCCASIONAL LIGHT PRECIP OVERNIGHT...PROBABLY MAINLY SNOW AS WE COOL OFF A BIT...ACCUMS WILL REMAIN AN INCH OR LESS WITH THE EXCEPTION OF THE LAURELS WHERE SOME WEAK OROGRAPHIC ENHANCEMENT COULD LEAD TO AN INCH OR TWO. OVERNIGHT LOWS AVERAGING IN THE 30S WILL BE A COUPLE OF DEGREES EITHER SIDE OF NORMAL. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... HEIGHTS ALOFT WILL START REBOUNDING RAPIDLY SUNDAY WHICH WILL LEAD TO IMPROVING SKIES AS DRY AIR WORKS IN FROM THE NW. HIGHS FROM AROUND 40 IN THE NORTH TO AROUND 50 IN THE SOUTH WILL BE THE BEGINNING OF THE MUCH ANTICIPATED BIG WARM UP THAT HAS BEEN ADVERTISED FOR THE LAST SEVERAL DAYS. && .LONG TERM /MONDAY THROUGH SATURDAY/... BROAD CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP DURING THE FIRST HALF OF THE UPCOMING WEEK...AS AN ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 12Z ECENS. TEMPS WILL TAKE A RUN AT 70F BY WED OVR SOUTHERN PA. MODELS ARE IN BETTER AGREEMENT ON BRINGING A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF THROUGH PA BY MIDWEEK...AS HIGH PRESSURE TRACKING EASTWARD ACROSS CANADA WILL NUDGE THE FRONT SOUTHWARD AND PIVOT IT FROM MORE OF A N-S ORIENTATION TO A W-E DIRECTION. THIS COULD BRING THE NEXT BEST CHANCE FOR PRECIPITATION AS WEAK WAVES COULD RIPPLE TOWARD PA ALONG THE PORTION OF THE /WARM/ FRONT OVER THE OHIO VALLEY. GIVEN THE STRONG WAA IT LOOKS TO BE ALL RAIN...WITH PRECIP BRACKETED BETWEEN LATE IN THE DAY WED AND FRI. THE GFS IS MORE AGGRESSIVE WITH ONSET OF PRECIP AND QPF AMOUNTS THAN THE ECMWF...BUT EITHER WAY IT LOOKS TO BE A SHOWERY END TO THE WEEK AND TEMPS GRADUALLY COOL BACK DOWN BUT REMAIN ABOVE NORMAL. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... 21Z TAFS SENT. MINOR ADJUSTMENTS MADE. BANDS OF SNOW TO THE WEST ABOUT ON TRACK. EARLIER DISCUSSION BELOW. MVFR OVER THE LAURELS...VFR ELSEWHERE WILL CONTINUE INTO THE LATE AFTERNOON HOURS BEFORE A STORM SYSTEM BRINGS AREAS OF LIGHT SNOW OR RAIN AND MORE WIDESPREAD REDUCED CONDITIONS BY LATE AFTERNOON INTO THE OVERNIGHT. CONFIDENCE IN IFR IS LOW DUE TO THE DISORGANIZED NATURE OF THE PRECIPITATION ASSOCIATED WITH THE WEAK-SPRAWLING LOW SLIDING SOUTH OF THE REGION. BEST CHANCE WOULD SEEM TO BE OVER THE HIGHER ELEVATIONS OF THE WEST IN NORTH...AND ONLY INTERMITTENTLY AS AREAS OF LIGHT SNOW SLIDE EAST THIS EVENING INTO THE OVERNIGHT. A MORE WIDESPREAD AREA OF MVFR CEILINGS IS LIKELY AFTER DARK INTO EARLY SUNDAY AS THE STRONGEST PART OF THE SHORTWAVE ALOFT MOVES THROUGH THE FLYING AREA WITH AREAS OF LIGHT SNOW POSSIBLY BRINGING BRIEF REDUCTIONS IN VISIBILITY INTO THE 1-3 MILE RANGE. EARLY MVFR CONDITIONS WILL STEADILY IMPROVE SUNDAY MORNING WITH ALL TERMINALS EXPECTED TO BE VFR BY MID MORNING OR MID DAY. OUTLOOK...SUNDAY-WEDNESDAY MON-TUE...VFR/NO SIG WX. WED...LOW CIGS/RAIN POSSIBLE NORTHWEST AS A COLD FRONT SAGS INTO THE AIRSPACE. THU...WIDESPREAD MVFR/IFR WITH RAIN SHOWERS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
347 PM EST SAT MAR 5 2016 .SYNOPSIS... A WEAK CLIPPER TYPE LOW WILL BRING THE CHANCE FOR LIGHT RAIN OR SNOW LATER TODAY INTO SUNDAY MORNING. A LARGE RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN HALF OF THE CONTINENT DURING THE UPCOMING WEEK BRINGING MUCH ABOVE NORMAL TEMPERATURES STARTING MONDAY...AND LASTING THROUGH AT LEAST MID WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... THE REGION IS CLOUDY AS OF MID DAY WITH TEMPERATURES GENERALLY IN THE 30S. DEWPOINTS RANGE FROM THE SINGLE DIGITS OVER EASTERN ZONES TO THE LOW 20S OVER THE SOUTHWEST. THIS DRY AIR IN PLACE IS DOING A FINE JOB IN KILLING WHAT LITTLE LIGHT PRECIP HAS BEEN MOVING INTO THE REGION WITH ONLY THE OBSERVING SITES OF THE SOUTHWEST REPORTING SOME INTERMITTENT LIGHT SNOW. A SPRAWLING AND WEAK LOW PRESSURE AREA IS DROPPING THROUGH THE LOWER LAKES TOWARD WEST VIRGINIA. THE PRECIPITATION SHIELD EVEN BACK INTO THE LOWER LAKES/OHIO VALLEY IS VERY DISORGANIZED...LEADING TO A FORECAST WHERE THE POPS MAY BE HIGH BUT THE QPF IS LOW. THE HRRR AND WRF-NMM SUGGEST THE BEST CHANCE OF LIGHT PRECIP WILL BE FROM ABOUT 21Z/4PM THROUGH ABOUT 09Z/4AM...WITH THE PERIOD FROM ABOUT 03-06Z HAVING THE MOST OVERALL COVERAGE OF ACTUAL PRECIP IN PROGRESS. IN GENERAL NO MORE THAN A TENTH OF AN INCH OF QPF IS EXPECTED IN MOST AREAS. WITH OCCASIONAL LIGHT PRECIP OVERNIGHT...PROBABLY MAINLY SNOW AS WE COOL OFF A BIT...ACCUMS WILL REMAIN AN INCH OR LESS WITH THE EXCEPTION OF THE LAURELS WHERE SOME WEAK OROGRAPHIC ENHANCEMENT COULD LEAD TO AN INCH OR TWO. OVERNIGHT LOWS AVERAGING IN THE 30S WILL BE A COUPLE OF DEGREES EITHER SIDE OF NORMAL. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... HEIGHTS ALOFT WILL START REBOUNDING RAPIDLY SUNDAY WHICH WILL LEAD TO IMPROVING SKIES AS DRY AIR WORKS IN FROM THE NW. HIGHS FROM AROUND 40 IN THE NORTH TO AROUND 50 IN THE SOUTH WILL BE THE BEGINNING OF THE MUCH ANTICIPATED BIG WARM UP THAT HAS BEEN ADVERTISED FOR THE LAST SEVERAL DAYS. && .LONG TERM /MONDAY THROUGH SATURDAY/... BROAD CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP DURING THE FIRST HALF OF THE UPCOMING WEEK...AS AN ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 12Z ECENS. TEMPS WILL TAKE A RUN AT 70F BY WED OVR SOUTHERN PA. MODELS ARE IN BETTER AGREEMENT ON BRINGING A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF THROUGH PA BY MIDWEEK...AS HIGH PRESSURE TRACKING EASTWARD ACROSS CANADA WILL NUDGE THE FRONT SOUTHWARD AND PIVOT IT FROM MORE OF A N-S ORIENTATION TO A W-E DIRECTION. THIS COULD BRING THE NEXT BEST CHANCE FOR PRECIPITATION AS WEAK WAVES COULD RIPPLE TOWARD PA ALONG THE PORTION OF THE /WARM/ FRONT OVER THE OHIO VALLEY. GIVEN THE STRONG WAA IT LOOKS TO BE ALL RAIN...WITH PRECIP BRACKETED BETWEEN LATE IN THE DAY WED AND FRI. THE GFS IS MORE AGGRESSIVE WITH ONSET OF PRECIP AND QPF AMOUNTS THAN THE ECMWF...BUT EITHER WAY IT LOOKS TO BE A SHOWERY END TO THE WEEK AND TEMPS GRADUALLY COOL BACK DOWN BUT REMAIN ABOVE NORMAL. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... MVFR OVER THE LAURELS...VFR ELSEWHERE WILL CONTINUE INTO THE LATE AFTERNOON HOURS BEFORE A STORM SYSTEM BRINGS AREAS OF LIGHT SNOW OR RAIN AND MORE WIDESPREAD REDUCED CONDITIONS BY LATE AFTERNOON INTO THE OVERNIGHT. CONFIDENCE IN IFR IS LOW DUE TO THE DISORGANIZED NATURE OF THE PRECIPITATION ASSOCIATED WITH THE WEAK-SPRAWLING LOW SLIDING SOUTH OF THE REGION. BEST CHANCE WOULD SEEM TO BE OVER THE HIGHER ELEVATIONS OF THE WEST IN NORTH...AND ONLY INTERMITTENTLY AS AREAS OF LIGHT SNOW SLIDE EAST THIS EVENING INTO THE OVERNIGHT. A MORE WIDESPREAD AREA OF MVFR CEILINGS IS LIKELY AFTER DARK INTO EARLY SUNDAY AS THE STRONGEST PART OF THE SHORTWAVE ALOFT MOVES THROUGH THE FLYING AREA WITH AREAS OF LIGHT SNOW POSSIBLY BRINGING BRIEF REDUCTIONS IN VISIBILITY INTO THE 1-3 MILE RANGE. EARLY MVFR CONDITIONS WILL STEADILY IMPROVE SUNDAY MORNING WITH ALL TERMINALS EXPECTED TO BE VFR BY MID MORNING OR MID DAY. OUTLOOK...SUNDAY-WEDNESDAY MON-TUE...VFR/NO SIG WX. WED...LOW CIGS/RAIN POSSIBLE NORTHWEST AS A COLD FRONT SAGS INTO THE AIRSPACE. THU...WIDESPREAD MVFR/IFR WITH RAIN SHOWERS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
125 PM EST SAT MAR 5 2016 .SYNOPSIS... A WEAK CLIPPER TYPE LOW WILL BRING THE CHANCE FOR LIGHT RAIN OR SNOW LATER TODAY INTO SUNDAY MORNING. A LARGE RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN HALF OF THE CONTINENT DURING THE UPCOMING WEEK BRINGING MUCH ABOVE NORMAL TEMPERATURES STARTING MONDAY...AND LASTING THROUGH AT LEAST MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE REGION IS CLOUDY AS OF MID DAY WITH TEMPERATURES GENERALLY IN THE 30S. DEWPOINTS RANGE FROM THE SINGLE DIGITS OVER EASTERN ZONES TO THE LOW 20S OVER THE SOUTHWEST. THIS DRY AIR IN PLACE IS DOING A FINE JOB IN KILLING WHAT LITTLE LIGHT PRECIP HAS BEEN MOVING INTO THE REGION WITH ONLY THE OBSERVING SITES OF THE SOUTHWEST REPORTING SOME INTERMITTENT LIGHT SNOW. A SPRAWLING AND WEAK LOW PRESSURE AREA IS DROPPING THROUGH THE LOWER LAKES TOWARD WEST VIRGINIA. THE PRECIPITATION SHIELD EVEN BACK INTO THE LOWER LAKES/OHIO VALLEY IS VERY DISORGANIZED...LEADING TO A FORECAST WHERE THE POPS MAY BE HIGH BUT THE QPF IS LOW. THE HRRR AND WRF-NMM SUGGEST THE BEST CHANCE OF LIGHT PRECIP WILL BE FROM ABOUT 21Z/4PM THROUGH ABOUT 09Z/4AM...WITH THE PERIOD FROM ABOUT 03-06Z HAVING THE MOST OVERALL COVERAGE OF ACTUAL PRECIP IN PROGRESS. IN GENERAL NO MORE THAN A TENTH OF AN INCH OF QPF IS EXPECTED IN MOST AREAS. WITH OCCASIONAL LIGHT PRECIP OVERNIGHT...PROBABLY MAINLY SNOW AS WE COOL OFF A BIT...ACCUMS WILL REMAIN AN INCH OR LESS WITH THE EXCEPTION OF THE LAURELS WHERE SOME WEAK OROGRAPHIC ENHANCEMENT COULD LEAD TO AN INCH OR TWO. OVERNIGHT LOWS AVERAGING IN THE 30S WILL BE A COUPLE OF DEGREES EITHER SIDE OF NORMAL. && .SHORT TERM / SUNDAY THROUGH 6 AM SUNDAY/... HEIGHTS ALOFT WILL START REBOUNDING RAPIDLY SUNDAY WHICH WILL LEAD TO IMPROVING SKIES AS DRY AIR WORKS IN FROM THE NW. HIGHS FROM AROUND 40 IN THE NORTH TO AROUND 50 IN THE SOUTH WILL BE THE BEGINNING OF THE MUCH ANTICIPATED BIG WARM UP THAT HAS BEEN ADVERTISED FOR THE LAST SEVERAL DAYS. && .LONG TERM /SUNDAY THROUGH SATURDAY/... AFTER SOME MORNING CLOUDS...AND FLURRIES ACROSS THE FAR SE DURING THE MORNING...LOOK FOR BRIGHTENING SKIES BUT STILL CHILLY CONDITIONS FOR LATE SUNDAY MORNING AND SUNDAY AFTERNOON AS HIGH PRES BUILDS IN FROM THE WEST WITH LIGHT NW SFC FLOW. BROAD CONSENSUS AMONG MED RANGE GUIDANCE IN A MARKED WARM UP DURING THE FIRST HALF OF THE UPCOMING WEEK...AS AN ANOMALOUS UPPER LVL RIDGE BUILDS OVR THE E COAST. BERMUDA HIGH AND ASSOC SW FLOW OVR PA DRAWS 8H TEMPS AS HIGH AS 12C BY MIDWEEK PER 12Z ECENS. TEMPS WILL TAKE A RUN AT 70F BY WED OVR SOUTHERN PA. MODELS ARE IN BETTER AGREEMENT ON BRINGING A QUASI-STATIONARY FRONTAL BOUNDARY RUNNING FROM THE MISS VALLEY THRU THE GRT LKS AT INTERFACE OF E COAST RIDGE AND PLAINS TROF THROUGH PA BY MIDWEEK...AS HIGH PRESSURE TRACKING EASTWARD ACROSS CANADA WILL NUDGE THE FRONT SOUTHWARD AND PIVOT IT FROM MORE OF A N-S ORIENTATION TO A W-E DIRECTION. THIS COULD BRING THE NEXT BEST CHANCE FOR PRECIPITATION AS WEAK WAVES COULD RIPPLE TOWARD PA ALONG THE PORTION OF THE /WARM/ FRONT OVER THE OHIO VALLEY. GIVEN THE STRONG WAA IT LOOKS TO BE ALL RAIN...WITH PRECIP BRACKETED BETWEEN LATE IN THE DAY WED AND FRI. THE GFS IS MORE AGGRESSIVE WITH ONSET OF PRECIP AND QPF AMOUNTS THAN THE ECMWF...BUT EITHER WAY IT LOOKS TO BE A SHOWERY END TO THE WEEK AND TEMPS GRADUALLY COOL BACK DOWN BUT REMAIN ABOVE NORMAL. && .AVIATION /17Z SATURDAY THROUGH THURSDAY/... MVFR OVER THE LAURELS...VFR ELSEWHERE WILL CONTINUE INTO THE LATE AFTERNOON HOURS BEFORE A STORM SYSTEM BRINGS AREAS OF LIGHT SNOW OR RAIN AND MORE WIDESPREAD REDUCED CONDITIONS BY LATE AFTERNOON INTO THE OVERNIGHT. CONFIDENCE IN IFR IS LOW DUE TO THE DISORGANIZED NATURE OF THE PRECIPITATION ASSOCIATED WITH THE WEAK-SPRAWLING LOW SLIDING SOUTH OF THE REGION. BEST CHANCE WOULD SEEM TO BE OVER THE HIGHER ELEVATIONS OF THE WEST IN NORTH...AND ONLY INTERMITTENTLY AS AREAS OF LIGHT SNOW SLIDE EAST THIS EVENING INTO THE OVERNIGHT. A MORE WIDESPREAD AREA OF MVFR CEILINGS IS LIKELY AFTER DARK INTO EARLY SUNDAY AS THE STRONGEST PART OF THE SHORTWAVE ALOFT MOVES THROUGH THE FLYING AREA WITH AREAS OF LIGHT SNOW POSSIBLY BRINGING BRIEF REDUCTIONS IN VISIBILITY INTO THE 1-3 MILE RANGE. EARLY MVFR CONDITIONS WILL STEADILY IMPROVE SUNDAY MORNING WITH ALL TERMINALS EXPECTED TO BE VFR BY MID MORNING OR MID DAY. OUTLOOK...SUNDAY-WEDNESDAY MON-TUE...VFR/NO SIG WX. WED...LOW CIGS/RAIN POSSIBLE NORTHWEST AS A COLD FRONT SAGS INTO THE AIRSPACE. THU...WIDESPREAD MVFR/IFR WITH RAIN SHOWERS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/RXR AVIATION...LA CORTE