Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/23/15


AREA FORECAST DISCUSSION
NWS ALBANY NY
415 PM EST SAT NOV 21 2015 .SYNOPSIS... A LOW PRESSURE WILL RACE NORTHEAST THROUGH THE EASTERN GREAT LAKES TONIGHT...AND DRAG A COLD FRONT ACROSS THE REGION WITH SCATTERED RAIN AND SNOW SHOWERS. ANY ACCUMULATION WILL BE CONFINED TO RIM OF THE MOHAWK VALLEY AND ADIRONDACKS. BREEZY NORTHWEST WINDS WILL BRING COOLER AIR BACK INTO THE AREA ON SUNDAY...ALONG WITH SOME LAKE EFFECT SNOW SHOWERS OVER THE ADIRONDACKS. MAINLY DRY AND COLD WEATHER IS EXPECTED ON MONDAY ALTHOUGH THERE COULD BE ADDITIONAL SNOW SHOWERS ACROSS THE ADIRONDACKS. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 415 PM EST...STILL DRY ACROSS OUR REGION. HIGH PRESSURE JUST TO OUR EAST WAS STILL IN CONTROL OF OUR WEATHER...WITH HIGH CLOUDS INCREASING OVER OUR REGION AHEAD OF THE NEXT DISTURBANCE. TEMPERATURES WERE GENERALLY IN THE 40S. THIS DISTURBANCE WAS AN AREA OF LOW PRESSURE OVER OHIO WHICH HAS PRODUCED A EARLY SEASON SNOWSTORM ACROSS PORTIONS OF THE GREAT LAKES. THIS STORM WILL TRACK NORTHEASTWARD INTO ONTARIO. IT WILL DRAG AN OCCLUDED FRONT THROUGH OUR REGION LATE TONIGHT. THE BEST FORCING AND MOISTURE WILL STAY WELL NORTH AND EAST OF THE CAPITAL REGION. INITIALLY ANY PRECIPITATION WILL START AS A RAIN SNOW MIX OVER THE ADIRONDACKS BUT SHOULD CHANGE TO ALL SNOW OVERNIGHT. ACCUMULATIONS LOOK MINOR AS SURFACE TEMPERATURES WILL ONLY BE MARGINALLY COLD ENOUGH FOR ACCUMULATIONS. FOR TONIGHT WE ARE LOOKING FOR A COATING TO TWO INCHES OVER THE ADIRONDACK PARK. FURTHER SOUTH AND EAST SHOWERS WILL BE MOST SCATTERED. SNOW FLAKES COULD MIX ANYWHERE BUT WILL LIKELY NOT PRODUCE ANY ACCUMULATION AS THE QPF LOOKS VERY LIGHT WITH SOME AREAS NOT GETTING ANY MEASURABLE AT ALL...ESPECIALLY SOUTH OF ALBANY. OVERNIGHT LOWS WILL RANGE FROM THE UPPER 20S TO MID 30S. IN SOME CASES... THEY MIGHT HAPPEN THIS EVENING BEFORE THICKER CLOUDS AND A BREEZE KICKS IN WHICH BOTH MIGHT WARM THE BOUNDARY A LITTLE IN THE VALLEYS. A SOUTH BREEZE WILL AVERAGE 5-15 MPH TONIGHT BECOME WESTERLY BY DAYBREAK AS THE FRONT MOVES ON BY. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... AS THE FRONT MOVES ON BY...CHILLIER AIR WILL FILTER INTO THE REGION. HOWEVER...WITH A WSW FLOW AND A GOOD DEAL OF SUNSHINE...TEMPERATURES WILL ACTUALLY WARM TO NEAR 50 IN THE VALLEYS...WHILE HOLDING CLOSER TO 40 ACROSS THE HIGHER TERRAIN. KEEP IN MIND THESE VALUES MIGHT HAPPEN BY MIDDAY...WITH TEMPERATURES FALLING A BIT DURING THE AFTERNOON. IT WILL BE BREEZY WITH A WEST WIND 10-15 MPH...GUSTING TO 25 MPH ESPECIALLY OVER THE HIGHER TERRAIN/MOHAWK VALLEY AND THE CAPITAL REGION. WHILE MOST OF THE AREA WILL BE DRY WITH PARTIAL SUNSHINE...LAKE ENHANCED CLOUDS AND PERHAPS SOME SNOW SHOWERS WILL PERSIST OVER THE ADIRONDACKS. EVEN IF SURFACE TEMPERATURES ARE ABOVE FREEZING ON SUNDAY...THE AIR WILL BE QUITE CHILLY ALOFT AND CERTAINLY VERTICAL INSTABILITY AND UPSLOPE COULD GENERATE THESE SNOW SHOWERS EVEN IN THE ABSENCE OF ANY PURE LAKE EFFECT. HOWEVER...AFTER EXAMINING THE EXPERIMENTAL KVIE CSTAR PROGRAM... IT NOW APPEARS THE INLAND LAKE EXTENT OFF OF ONTARIO WILL ONLY BE ABOUT 50 MILES...LIMITED DUE TO SOME SHEAR IN THE COLUMN AND DRY AIR IN THE MID LEVELS. THEREFORE PURE LAKE EFFECT SNOW PLUMES MIGHT ONLY GRAZE HERKIMER AND LIKELY NOT EVEN REACH HAMILTON COUNTIES. THEREFORE NO HEADLINES WERE ISSUED. IF CONDITIONS LOOK DIFFERENT LATER ON...HEADLINES WILL BE RECONSIDERED. ANY ADDITIONAL SNOW ACCUMULATIONS ON SUNDAY OVER THE ADIRONDACKS SHOULD LIGHT...AN INCH OR LESS. SUNDAY NIGHT THROUGH MONDAY NIGHT...LARGE HIGH PRESSURE WILL BUILD TO OUR SOUTH. ADDITIONAL SHORT WAVE ENERGY ALONG WITH ANOTHER MID LEVEL TROUGH ROLLING TO OUR NORTH... COULD TRIGGER A FEW MORE BOUTS OF SNOW SHOWERS WITH ADDITIONAL MAINLY MINOR ACCUMULATIONS OVER OUR ADIRONDACKS AND PERHAPS CENTRAL MOHAWK VALLEY. THIS AGAIN ASSUMES THE MAIN PLUMES OFF ONTARIO STAY MAINLY TO OUR WEST. IT WILL BE A CLOSE CALL BUT RIGHT NOW THEY APPEAR TO JUST MISS MOST OF OUR AREA. THE POTENTIAL IS THERE FOR 1-4 INCHES OF SNOWFALL WHEN IT IS ALL SAID AND DONE...SPREAD OUT OVER SEVERAL PERIODS SO AGAIN NO LAKE EFFECT SNOW ADVISORIES WERE ISSUED WITH THIS PACKAGE. KEEP IN MIND IF ANY PLUME FROM LAKE ONTARIO WAS ABLE TO PENETRATE INTO HERKIMER OR HAMILTON COUNTIES...AMOUNTS COULD BE LOCALLY A LITTLE HIGHER. THE REMAINDER OF THE REGION SHOULD REMAIN MOSTLY DRY ALTHOUGH A SPRINKLE OR FLURRY IS POSSIBLE ALONG WITH OCCASIONAL CLOUDINESS. OTHERWISE IT LOOKS CHILLY BUT NOTHING OUT OF THE ORDINARY FOR LATE NOVEMBER. LOW TEMPERATURES MONDAY MORNING WILL BE MAINLY IN THE 20S...WITH SOME TEENS IN THE COLDEST AREAS. HIGHS MONDAY WILL BE ONLY IN THE UPPER 20S TO MID 30S HIGHER TERRAIN...CLOSE TO 40 IN THE VALLEYS. BY TUESDAY...AS HIGH PRESSURE SLOWLY BEGINS TO BUILD ALOFT...THERE WILL BE SLOW MODERATION IN THE AIRMASS. ANY LINGERING SNOW SHOWERS WILL CEASE ACROSS THE ADIRONDACKS. OTHERWISE IT WILL BE MOSTLY SUNNY. LOWS TUESDAY MORNING WILL RANGE FROM THE MID TEENS TO MID 20S. HIGHS TUESDAY WILL RANGE FROM THE 30S OVER THE HIGHER TERRAIN... LOWER TO MID 40S IN THE VALLEYS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MAINLY DRY WEATHER WITH THE NEXT CHANCE FOR PRECIPITATION ACROSS THE REGION FRIDAY INTO SATURDAY AS A FRONTAL BOUNDARY MOVES ACROSS THE REGION. AT THE START OF THE LONG TERM PERIOD...THE LONG RANGE GUIDANCE CONTINUES TO BE IN VERY GOOD AGREEMENT WITH THE EVOLUTION OF THE LONG TERM PATTERN. MUCH OF THE LONG TERM PERIOD WILL BE DOMINATED BY HIGH PRESSURE AT THE SURFACE AND UPPER-LEVEL RIDGING ALOFT. THIS WILL RESULT IN AN EXTENDED PERIOD OF DRY WEATHER TUESDAY NIGHT THROUGH THURSDAY NIGHT...INCLUDING THANKSGIVING...WITH PARTLY CLOUDY SKIES. A FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION FRIDAY INTO THE SATURDAY TIME PERIOD. THERE IS SOME DIFFERENCE IN THE LONG RANGE GUIDANCE REGARDING THE TIMING OF THIS FRONTAL BOUNDARY...BUT HAVE INDICATED CHANCE POPS DURING THIS TIMEFRAME FOR RAIN SHOWERS DURING THE DAYTIME HOURS...AND A MIX OF RAIN/SNOW SHOWERS DURING THE NIGHTTIME HOURS WITH THE BEST CHANCE FOR SNOW ACROSS THE HIGHER TERRAIN. TEMPERATURES DURING THE LONG TERM PERIOD WILL BE SLIGHTLY ABOVE NORMAL FOR LATE NOVEMBER. HIGHS ON WEDNESDAY WILL RANGE FROM THE UPPER 30S/LOW 40S ACROSS THE HIGHER TERRAIN TO THE MID AND UPPER 40S IN VALLEY AREAS. HIGHS ON THURSDAY AND FRIDAY WILL RANGE FROM THE UPPER 40S TO MID 50S. HIGHS ON SATURDAY WILL RANGE FROM NEAR 40 TO NEAR 50. LOWS TUESDAY NIGHT WILL RANGE FROM THE MID TO UPPER 20S...UPPER 20S TO LOWER 30S WEDNESDAY NIGHT...AND MID 30S TO NEAR 40 THURSDAY AND FRIDAY NIGHTS. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... VFR CONDITIONS WILL CONTINUE THROUGH THE DAY TODAY...LOWERING TO MVFR LATER THIS EVENING AS STRATUS WORKS IN FROM THE SOUTH. A VARIABLE WIND WILL BECOME SOUTH AROUND 10KTS LATER THIS AFTERNOON OR EARLY EVENING. A SYSTEM WILL BRING THE CLOUDS THIS EVENING AND SOME SCATTERED RAIN SHOWERS...POSSIBLY MIXING WITH SNOW FLAKES LATER TOWARD DAYBREAK. FOR NOW...WE WILL ONLY WENT VCSH INTO EARLY SUNDAY. A FRONT WILL PASS THROUGH SHIFTING THE WIND TO THE WEST AROUND 10KTS WITH GUSTS TO 20KTS AT KPSF AND KALB. CONDITIONS WILL RETURN TO VFR WITH GOOD VISIBILITY AT THE TAF SITES SUNDAY. OUTLOOK... SUNDAY NIGHT-THANKSGIVING DAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A FRONTAL SYSTEM WILL BRING SOME SHOWERS OF RAIN AND SNOW TONIGHT... HEAVIEST ACROSS THE ADIRONDACKS WHERE A COUPLE INCHES OF SNOW COULD ACCUMULATE. OTHERWISE...RAIN SHOWER AMOUNTS WILL BE VERY LIGHT...WELL UNDER A QUARTER INCH MOST PLACES. ASIDE FROM ON GOING SNOW SHOWERS ACROSS THE ADIRONDACKS... THE REMAINDER OF THE REGION LOOKS MAINLY DRY SUNDAY THROUGH THANKSGIVING DAY. EACH NIGHT WILL SEE A NEAR RECOVERY OF RR VALUES...DROPPING TO SEASONABLE LEVELS IN THE 40S AND 50S EACH AFTERNOON. AMOUNTS WILL BE HIGHER ACROSS THE ADIRONDACKS WHERE THERE WILL BE POSSIBLE PRECIPITATION...GENERALLY IN THE 50S AND EVEN 60S. IT WILL BE SOMEWHAT BREEZY ON SUNDAY...WITH A WESTERLY WIND 10-15 MPH WITH GUSTS TO 25 MPH ACROSS THE HIGHER TERRAIN/MOHAWK VALLEY AND CAPITAL REGION. THE WIND WILL GENERALLY BE LIGHTER THROUGH THE REMAINDER OF THE WEEK. THE NEXT CHANCE OF WIDESPREAD PRECIPITATION AFTER TONIGHT DOES NOT APPEAR TO BE UNTIL LATE FRIDAY OR SATURDAY. && .HYDROLOGY... NO HYDROLOGY ISSUES ARE EXPECTED THROUGH THE NEXT WEEK. OTHER THAN THE POTENTIAL FOR SCATTERED SHOWERS TONIGHT AND LAKE ENHANCED SNOW SHOWERS IN HAMILTON AND HERKIMER COUNTIES SUNDAY...THE PERIOD WILL BE MAINLY DRY THROUGH FRIDAY. 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...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV LONG TERM...IRL AVIATION...HWJIV FIRE WEATHER...HWJIV HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
338 PM EST SAT NOV 21 2015 .SYNOPSIS... LOW PRESSURE LOCATED OVER WESTERN OHIO THIS AFTERNOON WILL PROGRESS NORTHEASTWARD AND INTO QUEBEC ON SUNDAY. THE LOW IS FORECAST TO PULL A COLD FRONT THROUGH OUR AREA LATE TONIGHT. HIGH PRESSURE SHOULD NOSE INTO OUR REGION FROM THE SOUTHWEST FOR SUNDAY INTO MONDAY. THE HIGH IS EXPECTED TO BE LOCATED OVER THE SOUTHEASTERN STATES ON MONDAY NIGHT. THE CENTER OF THE AIR MASS IS ANTICIPATED TO MOVE NORTHEASTWARD AND IT SHOULD REACH CANADA`S MARITIME PROVINCES ON WEDNESDAY. THE HIGH SHOULD CONTINUE TO INFLUENCE OUR WEATHER INTO FRIDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST IS FORECAST TO ARRIVE ON SATURDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AT LATE-DAY AN AREA OF HIGH PRESSURE WAS PULLING AWAY FROM OUR REGION TO THE NORTHEAST AS STRENGTHENING LOW PRESSURE WAS TRACKING FROM THE UPPER OHIO VALLEY TOWARD THE EASTERN GREAT LAKES. A COLD FRONT EXTENDED DOWN FROM THE OHIO VALLEY AND INTO THE SOUTHEAST STATES. THIS BOUNDARY WILL BE APPROACHING OUR AREA LATER TONIGHT, AND CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH THIS EVENING. NAM/GFS DATA AS WELL AS THE HRRR AND RAP OVERALL SHOW DISORGANIZED, WIDELY SCATTERED SHOWERS ASSOCIATED WITH THE FRONT, MAINLY AFTER MIDNIGHT, AS IT SWEEPS WEST TO EAST ACROSS THE FORECAST AREA. THE SPEED OF THE FRONT THROUGH THE AREA AND SOMEWHAT LIMITED MOISTURE ASSOCIATED WITH IT WILL LIMIT OVERALL PRECIP CHANCES AND AMOUNTS. CURRENT MODEL GUIDANCE CONTINUES TO FOCUS A BETTER CHANCE FOR SHOWERS FOR THE NORTHERN THIRD OF THE FORECAST AREA INTO THE POCONOS, LEHIGH VALLEY, AND NORTHERN NEW JERSEY, AND WE HAVE KEPT LOW CHANCE POPS FOR THESE AREAS, WITH MAINLY SLIGHT CHANCE ELSEWHERE. IN ADDITION, THERE IS THE POSSIBILITY FOR SOME WET SNOW TO MIX IN WITH THE RAIN SHOWERS ACROSS THE FAR NORTH BEFORE THE PRECIP ENDS DEPENDING ON HOW QUICKLY THE COLDER AIR ARRIVES BEHIND THE PASSING FRONT. OVERALL QPF AMOUNTS WITH THIS FRONT WILL BE LIGHT, WITH ONLY A FEW HUNDREDTHS OF AN INCH ANTICIPATED. MINIMUM TEMPERATURES ARE EXPECTED TO RANGE MOSTLY FROM THE LOWER 40S SOUTH TO THE MIDDLE 30S NORTH, WITH PERHAPS THE HIGHER TERRAIN IN THE POCONOS DROPPING INTO THE LOWER 30S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... THE PREVIOUSLY MENTIONED COLD FRONT WILL BE TO OUR EAST AND OFFSHORE INTO SUNDAY MORNING AS AN AREA OF LOW PRESSURE DEVELOPS ALONG THE BOUNDARY WELL TO OUR SOUTH, OFF THE COAST OF THE CAROLINAS. THIS LOW IS FORECAST TO REMAIN OFFSHORE AS IT PROGRESSES FARTHER NORTHEAST AND OUT TO SEA LATER SUNDAY TO SUNDAY EVENING. WHILE WE ARE EXPECTING THINNING CLOUDS AND CLEARING CONDITIONS FOR MUCH OF THE FORECAST AREA DURING THE MORNING, CLOUDS AND A FEW SHOWERS MAY HANG ON AT THE COAST THROUGH ABOUT MIDDAY OR SO AS SOME MOISTURE GETS DRAWN NORTHWARD IN THE SOUTHWEST FLOW ALOFT AHEAD OF THE LOW PRESSURE. OVERALL, WE KEPT CHANCE POPS IN PLACE THROUGH THE MORNING AT THE COAST AND FOR OUR COASTAL WATERS. IN TERMS OF TEMPERATURES AND WINDS, SOME OF THE COOLEST AIR OF THE AUTUMN SEASON THUS FAR WILL BEGIN SPREADING ACROSS THE REGION ON GUSTY NORTHWESTERLY WINDS, GUSTING AT TIMES TO AROUND 25 MPH. WE MOSTLY TOOK A BLEND OF MET/MAV GUIDANCE WITH CONTINUITY FOR MAXIMUM TEMPERATURES, AND WE EXPECT HIGHS TO MAINLY BE IN THE UPPER 40S TO LOWER 50S ACROSS THE REGION, WITH ONLY LOWER 40S EXPECTED INTO THE POCONOS. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... THE COLD FRONT WILL CONTINUE TO MOVE FARTHER OUT TO SEA ON SUNDAY NIGHT WITH A ROBUST LOW FORECAST TO DEVELOP ALONG THE BOUNDARY. THE THE MODEL GUIDANCE CONTINUES TO KEEP THE LOW WELL TO OUR EAST. THE CIRRUS SHIELD ASSOCIATED WITH THE SYSTEM SHOULD BE OVERHEAD ON SUNDAY EVENING BEFORE MOVING TO OUR EAST LATE ON SUNDAY NIGHT. A MID LEVEL SHORT WAVE TROUGH APPROACHING FROM THE WEST IS FORECAST TO PASS OVERHEAD ON MONDAY MORNING. THE COLDEST AIR OF THE NEW WEEK IS EXPECTED TO ARRIVE IN ITS WAKE FOR MONDAY. ANOTHER MID LEVEL SHORT WAVE TROUGH FROM THE NORTHWEST IS ANTICIPATED TO PASS OVER OUR REGION LATE ON MONDAY NIGHT. THE FEATURE IS EXPECTED TO BE PRECEDED BY SOME MID LEVEL CLOUDS ON MONDAY EVENING. IT MAY BE ACCOMPANIED AND FOLLOWED BY SOME STRATOCUMULUS OVER OUR NORTHERN COUNTIES ON MONDAY NIGHT. A MID LEVEL RIDGE IS FORECAST TO BUILD OVER THE EASTERN STATES AND THE WESTERN NORTH ATLANTIC DURING THE BALANCE OF THE NEW WEEK. SURFACE HIGH PRESSURE IS EXPECTED TO MOVE FROM THE SOUTHEASTERN STATES ON MONDAY NIGHT TO CANADA`S MARITIME PROVINCES ON WEDNESDAY. A TRAILING SURFACE RIDGE IS FORECAST TO EXTEND INTO OUR REGION INTO FRIDAY. WE ARE ANTICIPATING DRY WEATHER FOR THE COMING WEEK. TEMPERATURES WILL BEGIN ABOUT 10 DEGREES BELOW NORMAL ON MONDAY BUT THEY SHOULD REBOUND TO AROUND 6 TO 8 DEGREES ABOVE NORMAL FOR THANKSGIVING DAY AND FRIDAY. A COLD FRONT IS EXPECTED TO APPROACH FROM THE NORTHWEST ON FRIDAY NIGHT AND IT SHOULD PASS THROUGH OUR REGION ON SATURDAY. WE WILL INDICATE A CHANCE OF RAIN SHOWERS AT THAT TIME. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...MAINLY VFR CONDITIONS ARE EXPECTED TO CONTINUE THIS EVENING AND OVERNIGHT. A COLD FRONT WILL APPROACH THE REGION FROM THE WEST THIS EVENING, AND WE WILL SEE A GRADUAL THICKENING AND LOWERING OF VFR CLOUDS. WINDS THROUGH THIS EVENING WILL BE OUT OF THE EAST-SOUTHEAST AND MAINLY IN THE 5 TO 8 KNOT RANGE. THE COLD FRONT IS EXPECTED TO SWEEP ACROSS THE AREA BETWEEN ABOUT 07Z TO 12Z, AND AS THE FRONT PASSES THROUGH, WINDS WILL BECOME MORE WESTERLY TO WEST-NORTHWEST AND INCREASE SOME UP TOWARD 10 TO 12 KNOTS. IN ADDITION WITH THE PASSAGE OF THE FRONT THROUGH THE OVERNIGHT TO EARLY MORNING, CEILINGS WILL LOWER TOWARD ABOUT 3500 TO 4000 FEET WITH ISOLATED SHOWERS POSSIBLE, BUT AT THIS TIME, WE DO NOT EXPECT ANY EXTENDED TIME OF SUB-VFR CONDITIONS. SHOWERS WERE NOT INCLUDED IN THE TAFS AS THEY WILL BE BRIEF AND ISOLATED IN NATURE. SUNDAY...VFR CONDITIONS ARE EXPECTED BEHIND THE COLD FRONT WITH CLOUDS THINNING. NORTHWESTERLY WINDS WILL BECOME GUSTY FOR MOST SITES IN THE 12Z TO 14Z TIME FRAME AND CONTINUE THROUGH THE BULK OF THE DAY. GUSTS INTO THE 20 TO 25 KNOT RANGE ARE EXPECTED. OUTLOOK... SUNDAY NIGHT THROUGH WEDNESDAY...MAINLY VFR. WEDNESDAY NIGHT AND THURSDAY...MAINLY VFR. HOWEVER, PATCHY LATE NIGHT AND EARLY MORNING FOG IS POSSIBLE. && .MARINE... A COLD FRONT WILL BE CROSSING THE AREA DURING THE OVERNIGHT TO EARLY MORNING SUNDAY. AS THE FRONT PASSES, WINDS WILL SHIFT FROM THE SOUTHEAST TO WESTERLY AND THEN NORTHWESTERLY DURING THE DAYTIME SUNDAY. IN ADDITION, GUSTS WILL ALSO PICK UP BEHIND THE FRONT, WITH GUSTS AROUND 25 KNOTS PLUS BEGINNING AROUND DAYBREAK SUNDAY. SEAS WILL ALSO RESPOND WILL SOME 4 TO 5 FOOT SEAS FOR THE ATLANTIC COASTAL WATERS AND 2 TO 4 FOOT SEAS INTO DELAWARE BAY. WE HAVE RAISED A SMALL CRAFT ADVISORY FOR OUR COASTAL WATERS AND DELAWARE BAY BEGINNING 11Z SUNDAY. OUTLOOK... SUNDAY NIGHT...A SMALL CRAFT ADVISORY IS IN EFFECT FOR NORTHWEST WINDS GUSTING TO 25 TO 30 KNOTS. MONDAY...THE SMALL CRAFT ADVISORY MAY NEED TO BE EXTENDED IN TIME AS 25 KNOT WIND GUSTS FROM THE NORTHWEST MAY LINGER INTO AT LEAST PART OF MONDAY. MONDAY NIGHT THROUGH THURSDAY...NO MARINE HEADLINES ARE ANTICIPATED. && .TIDES/COASTAL FLOODING... A DEVELOPING ONSHORE FLOW ALONG WITH THE HIGH ASTRONOMICAL TIDES ASSOCIATED WITH THE UPCOMING FULL MOON MAY RESULT IN SOME MINOR COASTAL FLOODING DURING THE SECOND HALF OF THE WEEK. THE MORNING HIGH TIDE CYCLES ON THURSDAY AND FRIDAY SEEM MOST SUSCEPTIBLE. POSITIVE DEPARTURES OF ONLY 0.3 TO 0.6 FEET ARE NEEDED FOR MINOR FLOODING TO BEGIN. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 AM SUNDAY TO 6 AM EST MONDAY FOR ANZ430-431-450>455. && $$ SYNOPSIS...IOVINO NEAR TERM...KLINE SHORT TERM...KLINE LONG TERM...IOVINO AVIATION...IOVINO/KLINE MARINE...IOVINO/KLINE TIDES/COASTAL FLOODING...IOVINO
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EST SAT NOV 21 2015 ...INCREASED RAIN CHANCES THROUGH THIS WEEKEND FOLLOWED BY THE COOLEST AIR OF THE DRY SEASON THUS FAR... ...HAZARDOUS BOATING CONDITIONS DEVELOPING SUNDAY AND CONTINUING MOST OF NEXT WEEK... .UPDATE... CURRENT...SRLY COMPONENT TO METAR/C-MAN DATA OVER/OFFSHORE PB COUNTY AND GRAND BAHAMA ISLAND PLACE THE DIFFUSE FRONTAL BDRY (A WARM FRONT FOR THE TIME BEING) SOMEWHERE NORTH OF JUPITER INLET THIS MORNING. IT`S PROBABLY OVER NORTH LAKE OKEECHOBEE...BUT BASED ON RADAR HAS LIKELY LIFTED FARTHER NORTH OVER THE ATLC TO OFFSHORE BREVARD CO. BDRY ALSO EXTENDS WELL WEST INTO THE GOMEX TO A WEAK LOW PRES WAVE NEAR/ALONG 92W. WIDESPREAD MULTILAYERED CLOUDS ARE IN PLACE OVER THE PENINSULA. MORNING RAOBS SHOW RATHER UNIMPRESSIVE PWAT AT KXMR A LITTLE UNDER 1.5" WHILE DEEPER MEAN MOISTURE LURKS TO THE SOUTH (MFL 1.93") AND WEST (TBW 1.76"). WATER VAPOR AND RUC MID-UPPER ANLYS FIELDS SHOW VORTLOBES STUNG OUT ACROSS THE CENTRAL-ERN GOMEX WITH THE LEAD ONE PUSHING INTO SE FL NEAR PGD/FMY. IMPRESSIVE SRN STREAM 80-90KT H25 JETSTREAK EXTENDS FROM THE GULF ACROSS NORTH FL WITH EXPANSIVE SWATH OF DIVG OVHD. REMAINDER OF TODAY...ELEMENTS LOOK TO BE IN PLACE FOR INCREASING CHC OF RAIN OVER MUCH OF THE AREA AS INCREASING MOISTURE AND DEEP LAYER FORCED ASCENT BEGIN TO SPREAD EAST AND OVHD THROUGH LATER TODAY. LOCAL HRRR MODEL GUIDANCE SHOWS A GENEROUS COVERAGE A STRATIFORM RAIN WITH EMBEDDED CONVECTION WILL DEVELOP BY LATE AFTERNOON AND CONTINUE WELL INTO THIS EVENING. WHILE THIS MAY BE A TAD OVERDONE MAV GUIDANCE PAINTS 50-60 POPS FOR TODAY WITH THE MET (60-80) AND LAV (30-40) ON OPPOSITE SIDES. CURRENT GRIDS SHOW 50...WHICH SEEMS LIKE A DECENT COMPROMISE GIVEN CURRENT RADAR AND SATELLITE TRENDS. THINK CHC FOR THUNDER WILL BE QUITE LOW DUE TO ANTICIPATED LACK OF INSOLATION...BUT NON-ZERO AS IT WILL BE OFFSET TO SOME DEGREE BY COOLING ALOFT AND SLOWLY STRENGTHENING MEAN VV. ADDITIONALLY...WE ALREADY HAD ISOLD EMBEDDED THUNDER WITH CELLS ALONG THE TREASURE COAST AND WELL OFFSHORE BREVARD...SO EXPECT MORE OF THE SAME WITH MODEST DAYTIME HEATING THROUGH THIS AFTERNOON. GIVEN EXPECTED CLOUD COVER...NUDGED MAX TEMPS DOWN BY A DEGREE OR SO...RESULTING IN ALL AREAS REACHING THE U70S TO AROUND 80F OR SO. && .AVIATION...WIDESPREAD VFR OVC-BKN150 WITH LCL-AREAS MVFR BKN CIGS IN CONVECTIVE CU...INCREASING IN COVERAGE AFT 18Z. LCL IFR VSBYS IN +SHRA/TS...BUT GREATER COVERAGE OF MVFR VSBYS/CIGS IN PRECIP SHOULD BECOME MORE PREVALENT. && .MARINE...WARM FRONT MOVING NWD INTO THE MAOR HAS PUT A DENT IN THE SFC PGRAD. AS A RESULT WINDS ARE 20KT OR LESS WITH SEAS 3-4FT NEAR SHORE AND 5 TO OCNL 6FT WELL AWAY FROM THE COAST. CURRENT FORECAST WITH SCEC 20-60NM OFFSHORE NORTH OF SEBASTIAN INLET IS SPOT ON. NO CHGS NEEDED. && UPDATE/SHORT TERM/AVIATION...CRISTALDI LONG TERM/IMPACT WX/DSS....BLOTTMAN && .PREV DISCUSSION... /ISSUED 348 AM EST SAT NOV 21 2015/ TONIGHT...SOME OF THE DAYTIME CONVECTION MAY LINGER INTO EVENING... BUT THE GREATEST LARGE SCALE ASCENT AHEAD OF THE SHORTWAVE WILL BE AFTER MIDNIGHT. MOS POPS ARE VERY HIGH TONIGHT...75-90 PERCENT... WHICH LOOKS REASONABLE GIVEN THE IMPRESSIVE DIVERGENCE ALOFT WHICH IS DEPICTED BY THE GFS. HOWEVER THE BULK OF THIS PRECIP SHOULD BE QUITE LATE... SO HAVE KEPT OUR PREVIOUS FORECAST FOR AREAWIDE 70 PERCENT CHANCES. WILL ALSO KEEP MENTION OF SLIGHT CHANCE FOR STORMS OVERNIGHT DUE TO LARGE SCALE ASCENT AND WEAK ELEVATED INSTABILITY. SUN...AN AMORPHOUS AREA OF LOW PRESSURE WILL STRETCH FROM OFF THE SOUTHWEST COAST OF FLORIDA TOWARD THE ATLANTIC WATERS OFFSHORE GEORGIA/SOUTH CAROLINA. THE LOW WILL ORGANIZE NORTH OF THE BAHAMAS BEFORE ADVANCING QUICKLY TO THE NORTH AND EAST. AS IT DOES SO...A STRONG COLD FRONT WILL ADVANCE OVER THE AREA LATE SUNDAY INTO EARLY MONDAY. LARGE SCALE ASCENT ALOFT WILL BE ONGOING THROUGH THE MORNING AS LOW LEVEL CONVERGENCE IN ASSOCIATION WITH THE WEAK LOW SHIFTS TOWARDS THE CENTRAL/SOUTHERN PENINSULA. EXPECT SHOWER COVERAGE TO BE WIDESPREAD THROUGH AT LEAST THE FIRST HALF OF THE DAY. AS THE SYSTEM PULLS AWAY LATE SUNDAY...RAIN CHANCES WILL LOWER AND ABATE FROM NORTH TO SOUTH. CLOUDS WILL HOLD MAXES DOWN ON SUNDAY WHILE COLD AIR ADVECTION BEGINS IN EARNEST SUNDAY NIGHT. EXPECTING A LARGE SPREAD IN MINS...UPPER 40S ACROSS THE FAR NORTH AND 60-65 ALONG THE TREASURE COAST. CONSIDERING THE VERY WARM TEMPERATURES THUS FAR THIS FALL...AND THE FACT THAT WINDS ARE EXPECTED TO REMAIN BREEZY THROUGH THE OVERNIGHT AND INTO EARLY MONDAY MORNING...IT WILL FEEL QUITE CHILLY AS YOU HEAD OUT THE DOOR. MON-FRI...COLD FRONT WILL BE WELL SOUTH OF THE AREA BY SUNRISE MONDAY AS NORTHWEST WINDS USHER IN THE COOLEST AIR OF THE SEASON. MAX HIGHS WILL STRUGGLE TO ESCAPE THE 60S DURING THE DAY ON MONDAY. AS HAS BEEN THE CASE WITH NEARLY EVERY FROPA THIS SEASON...POST- FRONTAL WINDS WILL RAPIDLY VEER ONSHORE...MODIFYING THE AIR MASS FOR THE COASTAL COUNTIES AS EARLY AS MONDAY NIGHT. THIS WILL BE MOST PRONOUNCED ALONG THE TREASURE COAST GIVEN THE STILL-WARM SHELF WATER TEMPS THERE. AS FLOW VEERS ONSHORE LATE MONDAY INTO TUESDAY...WILL LIKELY SEE SIGNIFICANT MARINE STRATOCU FORM OVER THE ATLANTIC AND SPREAD INLAND. BRIEF LIGHT RAIN / SPRINKLES POSSIBLE TUESDAY (CONFINED TO THE COASTAL WATERS IN THIS FORECAST PACKAGE) BEFORE ONSHORE MOVING SHOWERS RE-ENTER THE PICTURE MID-WEEK AND BEYOND AS MOISTURE INCREASES IN DEEPENING EAST FLOW. MEANWHILE...TEMPS CLIMB TO NEAR CLIMO BY WEDNESDAY AND ABOVE THU-FRI. && .AVIATION... CONDITIONS SO FAR THIS MORNING HAVE MAINLY BEEN VFR EXCEPT FOR A FEW BRIEF MVFR CEILINGS. EXPECT THIS TREND TO CONTINUE...THEN AS DAYTIME HEATING CLOUDS FORM...MORE AREAS OF MVFR CEILINGS SHOULD FORM. SCATTERED SHOWERS AND A FEW STORMS ARE FORECAST DURING THE AFTERNOON AND EARLY EVENING. A HIGHER COVERAGE OF SHOWERS AND ISOLATED STORMS SHOULD SPREAD INLAND FROM THE GULF IN THE PRE DAWN HOURS OF SUNDAY. && .MARINE... TODAY-TONIGHT...EAST WINDS WILL GRADUALLY VEER TO SOUTHEAST AND EVEN SOUTH LATE IN THE DAY AS OLD FRONTAL TROUGH LIFTS BACK INTO THE WATERS. SPEEDS LOOK TO BE 10-15 KNOTS EARLY THIS MORNING AND EASING TO 10 KNOTS OR LESS THIS AFTERNOON. HAVE CANCELLED THE SMALL CRAFT ADVISORY AS TIGHTENED PRESSURE GRADIENT WAS BRIEF OVER OUR NORTHERN WATERS. EXPECT SCATTERED MAINLY AFTERNOON SHOWERS WITH A SLIGHT CHANCE OF STORMS THROUGH EARLY EVENING. A HIGHER COVERAGE OF SHOWERS WILL OCCUR IN THE PRE DAWN HOURS OF SUNDAY. SUN-WED...PRESSURE GRADIENT WILL START OFF RELAXED EARLY SUNDAY BEFORE TIGHTENING AS LOW PRESSURE ORGANIZES NORTH OF THE BAHAMAS. AS THE LOW PULLS AWAY TO THE NORTH AND EAST...A STRONG COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS LATE SUNDAY. STRONG SUSTAINED NORTHERLY WINDS OF AROUND 25 KNOTS WILL BUILD SEAS BEHIND THE FRONT...RESULTING IN A QUICK TRANSITION TO HAZARDOUS BOATING/SURF CONDITIONS THAT WILL LINGER THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. EXPECT HIGH END SCA CONDITIONS WITH GUSTS NEAR GALE FORCE...AND SEAS AS HIGH AS 12-13FT IN THE GULF STREAM...PERHAPS BRIEFLY HIGHER. WE ALSO MAY BE LOOKING AS DANGEROUS BEACH CONDITIONS EARLY NEXT WEEK WITH HIGH/CHOPPY SURF AND STRONG RIPS WITH POTENTIAL FOR ADVISORY CONDITIONS. && .PRELIMINARY POINT TEMPS/POPS... DAB 81 67 69 50 / 50 70 70 30 MCO 84 68 72 52 / 50 70 70 40 MLB 83 69 73 61 / 50 70 70 40 VRB 84 69 75 64 / 50 70 70 40 LEE 82 67 69 47 / 50 70 70 30 SFB 82 67 72 51 / 50 70 70 40 ORL 83 68 71 51 / 50 70 70 40 FPR 84 69 76 64 / 50 70 70 50 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
348 AM EST SAT NOV 21 2015 .DISCUSSION... ...INCREASED RAIN CHANCES THIS WEEKEND... ...HAZARDOUS BOATING CONDITIONS DEVELOPING SUNDAY AND CONTINUING MOST OF NEXT WEEK... TODAY-TONIGHT...HIGH MOISTURE BAND VICINITY OF OLD FRONT WAS OVER SOUTH FLORIDA AND INTO THE GULF OF MEXICO. SHORTWAVE TROUGH WILL MOVE THROUGH THE MID PART OF THE COUNTRY AND INDUCE A WEAK WAVE OF LOW PRESSURE ALONG THE BOUNDARY IN THE GULF. THIS WILL ALLOW THE BOUNDARY AND ASSOCIATED HIGH MOISTURE TO LIFT A LITTLE NORTHWARD. THOUGH WE WILL HAVE CONSIDERABLE HIGH LEVEL CLOUDINESS TO START OFF THE DAY...EXPECT A LITTLE HEATING AND WITH 500 MB TEMPS AROUND MINUS 9 CELSIUS...SUFFICIENT INSTABILITY WILL EXIST FOR ISOLATED LIGHTNING STORMS. THE HRRR MODEL HOURLY RUNS HAVE RANGED FROM EARLY CONVECTION ALONG REMNANT OLD FRONTAL BOUNDARY IN THE SOUTH...TO MORE RECENTLY HIGHLIGHTING NORTHERN AREAS WITH THE MOST CONVECTION AS EAST COAST SEA BREEZE MOVES INLAND. EARLY MORNING RADAR HAS NOT BEEN SHOWING MUCH SHOWER ACTIVITY OVER THE ATLANTIC AND WITH LIMITED DIRECT SOLAR INSOLATION TODAY...PREFER NOT TO GO WITH LIKELY POPS. INSTEAD WILL GO 50 PERCENT EVERYWHERE...WHICH IS WHAT THE 00Z MOS VALUES WERE. SOME OF THE DAYTIME CONVECTION MAY LINGER INTO EVENING...BUT THE GREATEST LARGE SCALE ASCENT AHEAD OF THE SHORTWAVE WILL BE AFTER MIDNIGHT. MOS POPS ARE VERY HIGH TONIGHT...75-90 PERCENT...WHICH LOOKS REASONABLE GIVEN THE IMPRESSIVE DIVERGENCE ALOFT DEPICTED BY THE GFS. HOWEVER THE BULK OF THIS PRECIP SHOULD BE QUITE LATE... SO HAVE KEPT OUR PREVIOUS FORECAST FOR AREAWIDE 70 PERCENT CHANCES. WILL ALSO KEEP MENTION OF SLIGHT CHANCE FOR STORMS OVERNIGHT DUE TO LARGE SCALE ASCENT AND WEAK ELEVATED INSTABILITY. SUN...AN AMORPHOUS AREA OF LOW PRESSURE WILL STRETCH FROM OFF THE SOUTHWEST COAST OF FLORIDA TOWARD THE ATLANTIC WATERS OFFSHORE GEORGIA/SOUTH CAROLINA. THE LOW WILL ORGANIZE NORTH OF THE BAHAMAS BEFORE ADVANCING QUICKLY TO THE NORTH AND EAST. AS IT DOES SO...A STRONG COLD FRONT WILL ADVANCE OVER THE AREA LATE SUNDAY INTO EARLY MONDAY. LARGE SCALE ASCENT ALOFT WILL BE ONGOING THROUGH THE MORNING AS LOW LEVEL CONVERGENCE IN ASSOCIATION WITH THE WEAK LOW SHIFTS TOWARDS THE CENTRAL/SOUTHERN PENINSULA. EXPECT SHOWER COVERAGE TO BE WIDESPREAD THROUGH AT LEAST THE FIRST HALF OF THE DAY. AS THE SYSTEM PULLS AWAY LATE SUNDAY...RAIN CHANCES WILL LOWER AND ABATE FROM NORTH TO SOUTH. CLOUDS WILL HOLD MAXES DOWN ON SUNDAY WHILE COLD AIR ADVECTION BEGINS IN EARNEST SUNDAY NIGHT. EXPECTING A LARGE SPREAD IN MINS...UPPER 40S ACROSS THE FAR NORTH AND 60-65 ALONG THE TREASURE COAST. CONSIDERING THE VERY WARM TEMPERATURES THUS FAR THIS FALL...AND THE FACT THAT WINDS ARE EXPECTED TO REMAIN BREEZY THROUGH THE OVERNIGHT AND INTO EARLY MONDAY MORNING...IT WILL FEEL QUITE CHILLY AS YOU HEAD OUT THE DOOR. MON-FRI...COLD FRONT WILL BE WELL SOUTH OF THE AREA BY SUNRISE MONDAY AS NORTHWEST WINDS USHER IN THE COOLEST AIR OF THE SEASON. MAX HIGHS WILL STRUGGLE TO ESCAPE THE 60S DURING THE DAY ON MONDAY. AS HAS BEEN THE CASE WITH NEARLY EVERY FROPA THIS SEASON...POST- FRONTAL WINDS WILL RAPIDLY VEER ONSHORE...MODIFYING THE AIR MASS FOR THE COASTAL COUNTIES AS EARLY AS MONDAY NIGHT. THIS WILL BE MOST PRONOUNCED ALONG THE TREASURE COAST GIVEN THE STILL-WARM SHELF WATER TEMPS THERE. AS FLOW VEERS ONSHORE LATE MONDAY INTO TUESDAY...WILL LIKELY SEE SIGNIFICANT MARINE STRATOCU FORM OVER THE ATLANTIC AND SPREAD INLAND. BRIEF LIGHT RAIN / SPRINKLES POSSIBLE TUESDAY (CONFINED TO THE COASTAL WATERS IN THIS FORECAST PACKAGE) BEFORE ONSHORE MOVING SHOWERS RE-ENTER THE PICTURE MID-WEEK AND BEYOND AS MOISTURE INCREASES IN DEEPENING EAST FLOW. MEANWHILE...TEMPS CLIMB TO NEAR CLIMO BY WEDNESDAY AND ABOVE THU-FRI. && .AVIATION... CONDITIONS SO FAR THIS MORNING HAVE MAINLY BEEN VFR EXCEPT FOR A FEW BRIEF MVFR CEILINGS. EXPECT THIS TREND TO CONTINUE...THEN AS DAYTIME HEATING CLOUDS FORM...MORE AREAS OF MVFR CEILINGS SHOULD FORM. SCATTERED SHOWERS AND A FEW STORMS ARE FORECAST DURING THE AFTERNOON AND EARLY EVENING. A HIGHER COVERAGE OF SHOWERS AND ISOLATED STORMS SHOULD SPREAD INLAND FROM THE GULF IN THE PRE DAWN HOURS OF SUNDAY. && .MARINE... TODAY-TONIGHT...EAST WINDS WILL GRADUALLY VEER TO SOUTHEAST AND EVEN SOUTH LATE IN THE DAY AS OLD FRONTAL TROUGH LIFTS BACK INTO THE WATERS. SPEEDS LOOK TO BE 10-15 KNOTS EARLY THIS MORNING AND EASING TO 10 KNOTS OR LESS THIS AFTERNOON. HAVE CANCELLED THE SMALL CRAFT ADVISORY AS TIGHTENED PRESSURE GRADIENT WAS BRIEF OVER OUR NORTHERN WATERS. EXPECT SCATTERED MAINLY AFTERNOON SHOWERS WITH A SLIGHT CHANCE OF STORMS THROUGH EARLY EVENING. A HIGHER COVERAGE OF SHOWERS WILL OCCUR IN THE PRE DAWN HOURS OF SUNDAY. SUN-WED...PRESSURE GRADIENT WILL START OFF RELAXED EARLY SUNDAY BEFORE TIGHTENING AS LOW PRESSURE ORGANIZES NORTH OF THE BAHAMAS. AS THE LOW PULLS AWAY TO THE NORTH AND EAST...A STRONG COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS LATE SUNDAY. STRONG SUSTAINED NORTHERLY WINDS OF AROUND 25 KNOTS WILL BUILD SEAS BEHIND THE FRONT...RESULTING IN A QUICK TRANSITION TO HAZARDOUS BOATING/SURF CONDITIONS THAT WILL LINGER THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. EXPECT HIGH END SCA CONDITIONS WITH GUSTS NEAR GALE FORCE...AND SEAS AS HIGH AS 12-13FT IN THE GULF STREAM...PERHAPS BRIEFLY HIGHER. WE ALSO MAY BE LOOKING AS DANGEROUS BEACH CONDITIONS EARLY NEXT WEEK WITH HIGH/CHOPPY SURF AND STRONG RIPS WITH POTENTIAL FOR ADVISORY CONDITIONS. && .PRELIMINARY POINT TEMPS/POPS... DAB 81 67 69 50 / 50 70 70 30 MCO 84 68 72 52 / 50 70 70 40 MLB 83 69 73 61 / 50 70 70 40 VRB 84 69 75 64 / 50 70 70 40 LEE 82 67 69 47 / 50 70 70 30 SFB 82 67 72 51 / 50 70 70 40 ORL 83 68 71 51 / 50 70 70 40 FPR 84 69 76 64 / 50 70 70 50 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...LASCODY LONG TERM....ULRICH
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
255 PM CST SAT NOV 21 2015 .SHORT TERM...(Tonight) ISSUED AT 255 PM CST SAT NOV 21 2015 20z/2pm surface analysis shows 1006mb low over west-central Ohio, with light snow lingering westward across much of the KILX CWA. The snow has ended and skies are beginning to clear west of the Illinois River, and this clearing will work its way steadily eastward over the next few hours. Satellite timing tools suggest the back edge of the cloud shield will be along a Bloomington to Shelbyville line by 00z/6pm...then will be into Indiana by 04z/10pm. Skies will then be clear across the board until late tonight when SCT-BKN mid-level clouds associated with a short-wave trough spill into the W/SW CWA toward dawn. Strong northwesterly winds gusting to between 20 and 30 mph early this evening will diminish to less than 10 mph and back to the W/SW overnight. Thanks to the clear skies and diminishing winds over a fresh snow-cover across the northern half of the CWA, this will be the coldest night thus far this season. Lows will drop into the teens in most areas, but will bottom out in the single digits where the snow cover is deepest across Knox, Stark, and Marshall counties. && .LONG TERM...(Sunday through Saturday) ISSUED AT 255 PM CST SAT NOV 21 2015 Cold air moving into the region overnight with clearing skies, and by Sunday morning, temperatures will drop into the single digits and teens. Brisk winds in the morning will result in wind chills dropping to -5C to 11C range. Sundays high temperatures will struggle into the 30s, with areas in the north and nearer to any remaining snow will have a hard time reaching the freezing mark, although southerly winds will assist to counter with some weak waa. Southwesterly flow aloft assists the warm up with the next system digging into the desert SW and amplifying the pattern across the CONUS. Big question for the first part of the week will be how much of the snow remains in the northern tier of the state. Have pulled down the temps both Monday and Tuesday from the SuperBlend to compensate for the influence of the snowpack. Elsewhere, temperatures start on a warming trend that will continue through the holiday. By Wednesday and Thursday, temps are above freezing through the overnight as well and the next system lays out a boundary across the region, providing a focus for plenty of rain in the Midwest in time for holiday travel. So far the models are keeping rain prolonged through Thanksgiving and into Friday. Disparity in the operational models with respect to the timing/clearing out of the wave. With ECMWF and the Canadian hinting at a kicker wave digging in over the Pacific, inclined to point the forecast towards a more rapid clearing. Cold air will move in again behind the system, with chilly temperatures back for next weekend. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) ISSUED AT 1218 PM CST SAT NOV 21 2015 IFR conditions will prevail at the central Illinois terminals for the next few hours...before the low clouds/snow begin to clear the area from west to east by mid to late afternoon. Latest satellite imagery shows back edge of clouds currently along the Mississippi River and advancing steadily eastward. Based on satellite timing tools and HRRR forecasts...have ended the snow at KPIA by 20z...then further east to KCMI by 22z. Skies will clear at KPIA by 22z...but will remain overcast further east at KCMI until around 01z. Northwesterly winds will become strong/gusty this afternoon through early evening. Current obs are already showing gusts in the 25 to 30kt range and these will continue/spread eastward through the remainder of the day. As low pressure lifts further northeastward and the pressure gradient relaxes...the gusts will subside by mid-evening. As high pressure approaches...winds will become light and gradually back to the SW late tonight into Sunday morning. && .ILX Watches/Warnings/Advisories... Winter Weather Advisory until 3 PM CST this afternoon for ILZ038- 043>046-055-057. && $$ SHORT TERM...Barnes LONG TERM...HJS AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1218 PM CST SAT NOV 21 2015 .UPDATE... ISSUED AT 1043 AM CST SAT NOV 21 2015 16z/10am surface analysis shows 1012mb low between KDEC and KMTO. Widespread precipitation is ongoing across all of central and southeast Illinois, with the rain/snow line along/south of a Taylorville to Robinson line. As the low shifts eastward into Indiana, northwesterly winds will cool the atmosphere sufficiently to support a rain/snow mix as far south as Olney/Lawrenceville this afternoon. Light to moderate snow will continue across the northern two-thirds of the KILX CWA through early afternoon before the precip gradually ends from west to east. Latest satellite imagery shows the back edge of the cloud/precip shield across eastern Iowa/northern Missouri and this will advance steadily eastward over the next few hours. Based on satellite timing tools and HRRR forecast, have lingered PoPs across the E/NE CWA a bit longer into the afternoon before ending all precip by 00z. Storm total snowfall with this system is on track with previous forecasts: however, have increased the amounts into the 6 to 8-inch range across Knox/Stark counties and have included amounts of 1 inch or less as far south as a Springfield to Mattoon line. && .SHORT TERM...(Today) ISSUED AT 336 AM CST SAT NOV 21 2015 the 09z/3am surface analysis shows the center of the low pressure in south-central Missouri, with a warm front extending across southern IL, roughly along I-70. The rain-snow line has maintained farther north...with snow remaining north of a line from Macomb to Peoria to Pontiac. The Peoria airport just SW of Peoria has little to no snow, while the north side of Peoria has what looks to be at least an inch of snow, and possibly more, on grassy surfaces based on IDOT cameras. Reports of 2.5" of snow have come in from Knox county observers in Altona and Abingdon earlier tonight. The RAP and HRRR take the surface low across southern IL, with deformation band snows continuing in our NW counties. Cold air along the northern edge of the system will gradually get pulled southward into our counties, prompting the rain to change to snow progressively farther south and east. Snowfall amounts look on track for our NW counties to be in the 3 to 6 inch range, with a sharp cutoff down to an inch or less. As the deformation band progresses across central IL into the afternoon, our NE counties could see snowfall amounts up to an inch or possibly a little more toward Hoopeston. We did not expand the winter weather advisory eastward, as snow amounts should remain enough below the 3" criteria for Champaign and Vermilion counties. The southern row of counties of our advisory (Fulton, Tazewell, McLean) will be borderline in terms of snow amounts as well, but will continue with headlines unchanged as there remains some uncertainty as to how soon the cold air will surge southward to change rain to snow, and how efficient of snowfall production will occur in our NW areas. Temps will remain warm enough for rain south of I-72 for a majority of the day, with any change to snow coming so late in the event that little to no snow accumulation is expected south of there. The center of the surface low is forecast to pull into Indiana by 11 am/17z, so cold air will invade on strong NW winds by early afternoon. High temps will likely occur by Noon in most areas because of that, with steady or falling temps this afternoon as winds increase to 25-30 mph. The snow should generally be too wet to blow around, but wind chills could drop into the teens in our W-NW counties. .LONG TERM...(Tonight through Friday) ISSUED AT 336 AM CST SAT NOV 21 2015 Strong short wave to lift ne of central IL early this evening with Canadian high pressure over the central Rockies quickly ridging east into the mid MS river valley by dawn Sunday. Clouds to decrease from west to east later this afternoon and into the evening while nw winds 15-25 mph at sunset today diminish to 5-10 mph overnight. Diminishing clouds and winds to bring a very cold night to the area especially over northern CWA where snow cover where lows will be 7- 13F with mid teens over central parts of CWA and upper teens to near 20F in southeast IL. Wind chills will lower to 5 above to 5 below zero northern cwa and 10-15 southeast IL. This will be the coldest night since March 6th over central IL. High pressure ridges into the Ohio river valley by sunset Sunday while upper level trof axis shifts east of IL. A mostly sunny but cold day with highs ranging form lower 30s from i-74 ne, mid 30s central CWA and upper 30s sw CWA. Winds to become ssw at 7-14 mph by Sunday afternoon. After a taste of winter weather this weekend for IL, temperatures to moderate back above normal during the upcoming work week with upper level heights rising over the region and nearly zonal upper level flow Monday becoming sw by mid week with strong upper level ridge in the east and strong upper level low/trof digging in the western states. Dry weather expected Monday through Wednesday with temps warming back up. Lows Sunday night in the mid to upper 20s. Highs Monday range from lower 40s from I-74 ne where remaining snow cover likely to melt while upper 40s to near 50F sw CWA. Highs by Wed in the low to mid 50s and mid to upper 50s on Thanksgiving day. 00Z models have trended slower with qpf returning to IL Wed night and Thu and looks like a wet period from Wed night into early Sat. GFS is quicker than ECMWF model with cold front moving through later Thu night and Friday with highest pops will likely be. Between 1 and 2 inches of rain appear possible during this time frame. Rain chances diminish next weekend and colder air returns to central/se IL. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) ISSUED AT 1218 PM CST SAT NOV 21 2015 IFR conditions will prevail at the central Illinois terminals for the next few hours...before the low clouds/snow begin to clear the area from west to east by mid to late afternoon. Latest satellite imagery shows back edge of clouds currently along the Mississippi River and advancing steadily eastward. Based on satellite timing tools and HRRR forecasts...have ended the snow at KPIA by 20z...then further east to KCMI by 22z. Skies will clear at KPIA by 22z...but will remain overcast further east at KCMI until around 01z. Northwesterly winds will become strong/gusty this afternoon through early evening. Current obs are already showing gusts in the 25 to 30kt range and these will continue/spread eastward through the remainder of the day. As low pressure lifts further northeastward and the pressure gradient relaxes...the gusts will subside by mid-evening. As high pressure approaches...winds will become light and gradually back to the SW late tonight into Sunday morning. && .ILX Watches/Warnings/Advisories... Winter Weather Advisory until 3 PM CST this afternoon for ILZ038- 043>046-055-057. && $$ UPDATE...Barnes SHORT TERM...Shimon LONG TERM...07 AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1043 AM CST SAT NOV 21 2015 .UPDATE... ISSUED AT 1043 AM CST SAT NOV 21 2015 16z/10am surface analysis shows 1012mb low between KDEC and KMTO. Widespread precipitation is ongoing across all of central and southeast Illinois, with the rain/snow line along/south of a Taylorville to Robinson line. As the low shifts eastward into Indiana, northwesterly winds will cool the atmosphere sufficiently to support a rain/snow mix as far south as Olney/Lawrenceville this afternoon. Light to moderate snow will continue across the northern two-thirds of the KILX CWA through early afternoon before the precip gradually ends from west to east. Latest satellite imagery shows the back edge of the cloud/precip shield across eastern Iowa/northern Missouri and this will advance steadily eastward over the next few hours. Based on satellite timing tools and HRRR forecast, have lingered PoPs across the E/NE CWA a bit longer into the afternoon before ending all precip by 00z. Storm total snowfall with this system is on track with previous forecasts: however, have increased the amounts into the 6 to 8-inch range across Knox/Stark counties and have included amounts of 1 inch or less as far south as a Springfield to Mattoon line. && .SHORT TERM...(Today) ISSUED AT 336 AM CST SAT NOV 21 2015 the 09z/3am surface analysis shows the center of the low pressure in south-central Missouri, with a warm front extending across southern IL, roughly along I-70. The rain-snow line has maintained farther north...with snow remaining north of a line from Macomb to Peoria to Pontiac. The Peoria airport just SW of Peoria has little to no snow, while the north side of Peoria has what looks to be at least an inch of snow, and possibly more, on grassy surfaces based on IDOT cameras. Reports of 2.5" of snow have come in from Knox county observers in Altona and Abingdon earlier tonight. The RAP and HRRR take the surface low across southern IL, with deformation band snows continuing in our NW counties. Cold air along the northern edge of the system will gradually get pulled southward into our counties, prompting the rain to change to snow progressively farther south and east. Snowfall amounts look on track for our NW counties to be in the 3 to 6 inch range, with a sharp cutoff down to an inch or less. As the deformation band progresses across central IL into the afternoon, our NE counties could see snowfall amounts up to an inch or possibly a little more toward Hoopeston. We did not expand the winter weather advisory eastward, as snow amounts should remain enough below the 3" criteria for Champaign and Vermilion counties. The southern row of counties of our advisory (Fulton, Tazewell, McLean) will be borderline in terms of snow amounts as well, but will continue with headlines unchanged as there remains some uncertainty as to how soon the cold air will surge southward to change rain to snow, and how efficient of snowfall production will occur in our NW areas. Temps will remain warm enough for rain south of I-72 for a majority of the day, with any change to snow coming so late in the event that little to no snow accumulation is expected south of there. The center of the surface low is forecast to pull into Indiana by 11 am/17z, so cold air will invade on strong NW winds by early afternoon. High temps will likely occur by Noon in most areas because of that, with steady or falling temps this afternoon as winds increase to 25-30 mph. The snow should generally be too wet to blow around, but wind chills could drop into the teens in our W-NW counties. .LONG TERM...(Tonight through Friday) ISSUED AT 336 AM CST SAT NOV 21 2015 Strong short wave to lift ne of central IL early this evening with Canadian high pressure over the central Rockies quickly ridging east into the mid MS river valley by dawn Sunday. Clouds to decrease from west to east later this afternoon and into the evening while nw winds 15-25 mph at sunset today diminish to 5-10 mph overnight. Diminishing clouds and winds to bring a very cold night to the area especially over northern CWA where snow cover where lows will be 7- 13F with mid teens over central parts of CWA and upper teens to near 20F in southeast IL. Wind chills will lower to 5 above to 5 below zero northern cwa and 10-15 southeast IL. This will be the coldest night since March 6th over central IL. High pressure ridges into the Ohio river valley by sunset Sunday while upper level trof axis shifts east of IL. A mostly sunny but cold day with highs ranging form lower 30s from i-74 ne, mid 30s central CWA and upper 30s sw CWA. Winds to become ssw at 7-14 mph by Sunday afternoon. After a taste of winter weather this weekend for IL, temperatures to moderate back above normal during the upcoming work week with upper level heights rising over the region and nearly zonal upper level flow Monday becoming sw by mid week with strong upper level ridge in the east and strong upper level low/trof digging in the western states. Dry weather expected Monday through Wednesday with temps warming back up. Lows Sunday night in the mid to upper 20s. Highs Monday range from lower 40s from I-74 ne where remaining snow cover likely to melt while upper 40s to near 50F sw CWA. Highs by Wed in the low to mid 50s and mid to upper 50s on Thanksgiving day. 00Z models have trended slower with qpf returning to IL Wed night and Thu and looks like a wet period from Wed night into early Sat. GFS is quicker than ECMWF model with cold front moving through later Thu night and Friday with highest pops will likely be. Between 1 and 2 inches of rain appear possible during this time frame. Rain chances diminish next weekend and colder air returns to central/se IL. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) ISSUED AT 600 AM CST SAT NOV 21 2015 Conditions are expected to continue at IFR or LIFR for PIA and BMI where snow will fall through the morning and into early afternoon. IFR conditions will develop at SPI, DEC and CMI as the morning progresses, as rain changes to snow. Low pressure will pass south of the area this morning, roughly just south of I-70. The low will move into Indiana before Noon/18z, causing winds to shift to the NE, then N, then NW by afternoon for all TAF sites. Wind speeds will increase to 15 to 20kt after 15z, with gusts to 30kt at times this afternoon. Winds will diminish to 8-12kt after 00z. Initially, surface temps will hover right around or just above freezing early this morning for a few hours. Ground temperatures are generally above freezing, so snow accumulation on travel surfaces will remain lower than grassy areas. 1 inch of slushy accumulation could occur at PIA, with less than an inch at BMI and CMI, and little to no snow accumulation at DEC and SPI. IFR conditions should gradually improve to MVFR during the afternoon and then to VFR after 00-03z. && .ILX Watches/Warnings/Advisories... Winter Weather Advisory until noon CST today for ILZ027>031- 036>038. && $$ UPDATE...Barnes SHORT TERM...Shimon LONG TERM...07 AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1012 AM CST SAT NOV 21 2015 .UPDATE... 915 AM CST ONLY CHANGE TO HEADLINES WAS TO UPGRADE ADVISORY TO A WINTER STORM WARNING FOR LAKE AND PORTER COUNTIES IN NORTHWEST INDIANA. MAJORITY OF FORECAST CONTINUES WELL ON TRACK...INCLUDING FOR THE MOST PART SNOWFALL TOTALS AND ENDING TIMES TODAY. THE WELL-DEFINED TROUGH ON SATELLITE THIS MORNING IS SWINGING INTO THE AREA...PIVOTING SLIGHTLY MORE NEGATIVELY TILTED...WITH RAPID MID-LEVEL AND DYNAMIC COOLING. AN IMPRESSIVE 500MB TEMPERATURE DIFFERENCE FROM MPX TO DVN OF 16C HIGHLIGHTS THAT. THE SURFACE TEMPERATURES ARE STARTING TO SLOWLY FALL IN NORTH CENTRAL ILLINOIS WITH NORTHERLY WINDS. TEMPERATURES ARE ALSO BEGINNING TO SLOWLY COOL NEAR THE IMMEDIATE LAKE SHORE OF NORTHEAST ILLINOIS...INCLUDING DOWNTOWN CHICAGO...WHERE RAIN OR RAIN/SNOW MIX WITH LITTLE TO NO ACCUMULATION HAS BEEN REPORTED THUS FAR THIS MORNING. EXPECTING TO SEE THESE LOCATIONS TURN OVER TO ALL SNOW FOR GOOD OVER THE NEXT COUPLE HOURS. AS DEFORMATION ENVELOPS THE AREA AS NOTED IN THE PREVIOUS DISCUSSION...WE SHOULD CONTINUE TO SEE HEAVIER SNOW BLOSSOM ON RADAR WHICH WE HAVE NOTICED UNDULATE SINCE 7 AM. AREAS OF HALF MILE AND TEMPORARY QUARTER MILE VISIBILITY HAVE BEEN OBSERVED UNDER THESE. SNOWFLAKE QUALITY...OR SNOW RATIOS...ALSO APPEAR TO INCREASE IN THESE AREAS BASED ON OUT OUR WINDOW AND A FEW OTHER REPORTS. THAT WOULD LINE UP WITH SATURATION PROFILES...ESPECIALLY WHERE THE WINDS ARE LIGHTER IN THE LOW-LEVELS /LESS FLAKE FRAGMENTING/...SUCH AS NORTHEAST ILLINOIS AND FAR NORTHWEST INDIANA AT PRESENT. TEMPORARY ONE INCH PER HOUR RATES WILL BE MOST FAVORED IN THESE AREAS. LAKE ENHANCEMENT CONTINUES TO BE SEEN NEAR THE WI/IL STATE LINE...WITH EVEN SOME 40 MPH GUSTS ON THE IMMEDIATE SOUTHEAST WISCONSIN SHORE LIKELY INDICATING THE PRESENCE OF SHARPENING CONVERGENCE AND STEEP LAPSE RATES. THIS ENHANCEMENT WILL SLOWLY MOVE SOUTHWARD THROUGH EARLY AFTERNOON...WITH THE LONGEST RESIDENCE TIME JUST NORTH OF CHICAGO IT WOULD APPEAR ON THE HRRR AND RAP PREDICTED WIND FIELDS. THIS WILL SHIFT INTO NORTHWEST INDIANA DURING THE MID AFTERNOON OR SO AND FURTHER INCREASE RATES AND TOTAL SNOW. WHILE SNOWFALL TOTALS IN PARTS OF LAKE AND PORTER ARE LIKELY TO NOT REACH SIX INCHES...THE COMBINATION OF THE HEAVIER SYNOPTIC AND EXPECTED LATER MESOSCALE RATES DURING THE DAYTIME...AND THE FIRST EVENT OF THE YEAR...HAVE COLLABORATED THE UPGRADE TO WARNING FOR THERE. MTF && .SHORT TERM... 330 AM CST THROUGH MONDAY... A VERY IMPRESSIVE DYNAMIC EARLY SEASON STORM SYSTEM HAS ONLY PRESENTED ITS FIRST PUNCH TO PORTIONS OF THE AREA. YESTERDAY EVENING...A VERY STRONGLY FRONTOGENTICALLY FORCED HEAVY SNOW BAND DEVELOPED OVER FAR NORTHERN ILLINOIS AND DROPPED UP TO 10 INCHES WITHIN A FEW HOURS. HOWEVER...AREAS FARTHER SOUTH RECEIVED LIGHTER AMOUNTS OUT OF THIS FIRST PERIOD OF SNOW. THIS IS EXPECTED TO CHANGE THIS MORNING...HOWEVER...AS ADDITIONAL MODERATE TO OCCASIONALLY HEAVY BANDS OF SNOW DEVELOP OVER THE AREA AND PRESENT THE OPPORTUNITY FOR AREAS SOUTH OF YESTERDAY EVENINGS HEAVY SNOW EVENT TO GET SNOW ACCUMULATION. THE TRACKS OF THE 850 AND 700 MB LOWS APPEAR QUITE FAVORABLE FOR HEAVY SNOW ACROSS NORTHERN ILLINOIS AND NORTHWESTERN INDIANA TODAY. STRONG Q-VECTOR CONVERGENCE IS EXPECTED TO SET UP OVER THE REGION THIS MORNING AS THE MAIN MID LEVEL SHORT WAVE TRANSITIONS TO A NEGATIVE TILT. THIS SUGGESTS THE PRESENCE OF STRONG LARGE SCALE FORCING FOR ASCENT...ESPECIALLY CONSIDERING THE AREA WILL RESIDE WITHIN THE FAVORABLE LEFT EXIT REGION OF A 120+ KT UPPER LEVEL JET. AS THE LOWER LEVEL LOW SHIFTS EASTWARD OVER ILLINOIS...THIS WILL RESULT IN A CORRIDOR OF RATHER STOUT DEFORMATION...AND THE RESULTANT BANDS OF FRONTOGENESIS SHOULD DIVE AN AREA OF MODERATE...TO OCCASIONALLY HEAVY SNOW OVER THE AREA TODAY. THIS STRONG FORCING FOR ASCENT ALSO LOOKS TO BE COMPLEMENTED...AT LEAST OVER NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA...BY FAVORABLE THERMODYNAMICS FOR LAKE ENHANCEMENT. SURFACE TEMPERATURES HAVE REMAINED AT...OR A COUPLE OF DEGREES ABOVE FREEZING THROUGH THE NIGHT IN MOST AREAS OUTSIDE OF NORTH CENTRAL ILLINOIS...AND THIS HAS RESULTED IN LITTLE SNOW ACCUMULATION...ESPECIALLY CONSIDERING SNOW RATES HAVE REMAINED FAIRLY LIGHT OVERNIGHT. SURFACE TEMPERATURES SHOULD BEGIN TO COOL TO AND BELOW FREEZING DURING THE DAY AS HEAVIER PRECIPITATION RATES DEVELOP...AND THIS SHOULD ALLOW SNOW TO ACCUMULATE...ESPECIALLY ON GRASSY AREAS. IT IS A BIT UNCERTAIN HOW MUCH SNOW WILL ACCUMULATE ON PAVEMENT...DUE TO THE WARMER TEMPERATURES. HOWEVER...AT LEAST SOME SLUSHY ACCUMS LOOKS POSSIBLE. AS MENTIONED ABOVE...THERMODYNAMICS SHOULD BECOME INCREASING FAVORABLE FOR A LAKE ENHANCED BAND OF SNOW TO DEVELOP OVER NORTHEASTERN ILLINOIS AND EVENTUALLY NORTHWESTERN INDIANA. COOLER MID-LEVEL TEMPERATURES MOVING OVER THE AREA SHOULD SET UP THESE FAVORABLE CONDITIONS. HI-RES GUIDANCE IS ACTUALLY PICKING UP ON THIS...AND SUGGESTS THAT A HEAVY LAKE ENHANCED BAND OF HEAVY SNOW WILL IMPACT PORTIONS OF NORTHEASTERN ILLINOIS THIS MORNING. IT APPEARS THAT THE STORM SYSTEM WILL TRACK A BIT FARTHER SOUTH THEN WHAT WAS ANTICIPATED EARLIER. THEREFORE...IT APPEARS THAT AREAS OUTSIDE THE CURRENT ADVISORY COULD END UP GETTING A FEW INCHES OF ACCUMULATION TODAY. BECAUSE OF THIS...WE OPTED TO EXPAND THE WINTER WX ADVISORY FARTHER SOUTH TO COVER THE REST OF MY AREA. OVERALL...IT APPEARS THE HEAVIEST SNOW TODAY WILL FALL DURING THE MORNING...THEN BEGIN TAPERING OFF FROM WEST TO EAST THROUGH THE AFTERNOON. LAKE ENHANCED SNOW SHOWERS COULD LINGER INTO THE EVENING OVER FAR NORTHEASTERN PORTER. OTHERWISE...THINGS SHOULD BE DONE IN MOST AREAS BY LATER THIS AFTERNOON. IT APPEARS THAT AMOUNTS OF 3 TO 7 INCHES COULD FALL ACROSS THE AREA TODAY. THEREFORE...NO CHANGES ARE PLANED TO THE HEADLINES...ASIDE FROM THE EXPANSION MENTIONED. NORTH-NORTHWESTERLY WINDS WILL BECOME VERY GUSTY THIS AFTERNOON AS THE SURFACE LOW TRACKS OVER THE EASTERN GREAT LAKES REGION. THESE STRONGER WINDS COULD PRODUCE SOME BLOWING SNOW. HOWEVER...DUE TO THE WETTER NATURE OF THE SNOW...THIS MAY NOT BE TOO BIG OF AN ISSUE...AND I HAVE OPTED TO LEAVE THE MENTION OUT OF THE FORECAST AT THIS TIME. OTHERWISE...EXPECT A VERY COLD NIGHT TONIGHT WITH THE FRESH SNOW ON THE GROUND. AREAS ACROSS NORTH CENTRAL ILLINOIS LOOK TO DROP INTO THE SINGLE DIGITS...WITH TEENS LIKELY IN MOST OTHER AREAS. SUBFREEZING TEMPERATURES WILL CONTINUE SUNDAY...BEFORE TEMPERATURES BEGIN TO INCH ABOVE FREEZING ON MONDAY. KJB && .LONG TERM... 238 AM CST TUESDAY THROUGH FRIDAY... THE EXTENDED BEGINS QUIETLY WITH HIGH PRESSURE SHIFTING FROM THE SOUTHEAST U.S. TO NEW ENGLAND BY WEDNESDAY MORNING. WINDS TURN SOUTH WEDNESDAY USHERING IN WARMER AIR. THIS IS REFLECTED IN HIGH TEMPS WHICH WILL JUMP FROM THE UPPER 30S TO MID 40S TUESDAY TO THE LOW TO MID 50S THURSDAY. A WEAKENING MID LEVEL SHORTWAVE TROUGH PASSES OVER THE REGION WEDNESDAY BRINGING A SLIGHT CHANCE TO CHANCE OF LIGHT RAIN WITH IT. HAVE MORE CONFIDENCE IN RAIN WEDNESDAY NIGHT THAN WEDNESDAY AS THE NEXT LOW/S WARM FRONT LIFTS NORTH OVER THE REGION...BUT ONLY EXPECTING LIGHT RAIN. THE LOW ARRIVES OVER IOWA THURSDAY MORNING AND CONTINUES NORTHEAST THROUGH LATE IN THE WEEK. THE GFS IS MORE AGGRESSIVE WITH THE RAIN/S PROGRESSION THURSDAY. THINKING AREAS WEST OF I-55 WILL LIKELY SEE RAIN WHILE THE GFS SUGGESTS THE WHOLE WARNING AREA WILL RECEIVE RAIN. GUSTY SOUTH WINDS ARE ALSO EXPECTED THURSDAY WITH GUSTS UP TO 30 MPH. THE LOW/S COLD FRONT SWINGS THROUGH FRIDAY LEADING TO COOLER TEMPS...AN END TO THE RAIN...AND NORTHWEST TO WEST WINDS. HIGH TEMPS FRIDAY WILL STILL BE AROUND TO SLIGHTLY ABOVE AVERAGE RANGING FROM THE MID 40S TO AROUND 50. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * ONGOING SNOW THROUGH THE EARLY AFTERNOON. VSBYS WILL DROP AGAIN TO NEAR 1/2SM WITH A LAKE EFFECT BAND FROM 17-202Z. * IFR TO LIFR CIGS IMPROVING IN THE AFTERNOON. * NORTHEAST WINDS ARE SHIFTING NORTHERLY CURRENTLY. ANOTHER SHIFT TO NNW AND GUST TO 20-25KT EXPECTED THIS AFTN. MM //DISCUSSION...UPDATED 12Z... SNOW WILL INCREASE THIS MORNING WITH 3/4 SM VSBY EXPECTED AT ALL OF THE TAF SITES. PERIODS OF 1/4 SM VSBY ARE NOT OUT OF THE QUESTION ACROSS THE EASTERN TERMINALS. A LAKE EFFECT BAND WILL FORM LATE THIS MORNING AND ROTATE OVER THE EASTERN TERMINALS. 1/4SM WITH HEAVY SNOW IS EXPECTED UNDER THIS BAND ALONG WITH QUICK ACCUMULATIONS. HOWEVER THE BAND WILL BE TRANSIENT SO THE HEAVY SNOW WILL LAST ABOUT AN HOUR OR LESS. RFD WILL NOT BE AFFECTED BY THE BAND AND WILL SEE THE SNOW END FIRST AROUND NOON. EAST WINDS WILL BE LESS THAN 10 KT EARLY THIS MORNING AND INCREASE TO CLOSE TO 10 KT LATE THIS MORNING. WINDS WILL BE BACKING LATE THIS MORNING AND BECOME NORTHWEST GUSTING TO 20-25 KT EARLY THIS AFTN. FLURRIES OR LIGHT SNOW MAY PERSIST PAST 19Z AT THE EASTERN TERMINALS...BUT NOT EXPECTING ANY SIGNIFICANT IMPACT FROM THE LINGERING SNOW. LIFR CIGS WILL LIFT AFTER THE SNOW TO MVFR AND CLEAR OUT THIS EVENING WITH WINDS BECOMING SOUTHWEST SUNDAY MORNING. JEE //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH ON SNOW VSBYS THE NEXT 2 HOURS...MEDIUM HIGH CONFIDENCE IN A LAKE EFFECT BAND DEVELOPING...BUT MEDIUM ON TIMING AND LOWESTY VSBYS. * HIGH ON CIG TRENDS. * MEDIUM ON WIND TRENDS. MM //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...VFR. SOUTHWEST WINDS. MONDAY...VFR. WEST WINDS. TUESDAY...VFR. SOUTH WINDS. WEDNESDAY...SCHC-CHC -RA. SOUTH WINDS. THURSDAY...RA LIKELY. MVFR PSBL. GUSTY SOUTH WINDS BECOMING WEST. FRIDAY...CHC RAIN. IMPROVING TO VFR. NORTHWEST WINDS. JEE && .MARINE... 238 AM CST NO CHANGES TO CURRENT SMALL CRAFT ADVISORY AND GALE WARNING. WILL LIKELY NEED ANOTHER GALE HEADLINE FOR THE SOUTHERN HALF OF THE LAKE SUNDAY EVENING AND NIGHT...BUT WILL HOLD OFF ON ISSUING ONE NOW GIVEN THE CURRENT HEADLINES. WINDS WILL BECOME NORTH TO NORTHWEST ACROSS THE LAKE THIS AFTERNOON AS THE LOW PRESSURE SYSTEM CURRENTLY OVER TEXAS MOVES OVER THE OHIO RIVER VALLEY. NW WINDS WILL INCREASE TO GALE FORCE ACROSS THE SOUTHERN HALF OF THE LAKE AND INDIANA NEARSHORE ZONES. WINDS DIMINISH OVERNIGHT AS THE LOW MOVES OVER QUEBEC. HIGH PRESSURE SPREADS OVER THE SOUTHERN MISSISSIPPI VALLEY AND SOUTHEAST U.S. AS ANOTHER LOW SHIFTS SOUTHEAST OVER ONTARIO SUNDAY NIGHT INTO MONDAY. WINDS BACK TO SOUTHWEST AND GALES ARE EXPECTED SUNDAY NIGHT ACROSS THE SOUTHERN HALF OF THE LAKE. WINDS DIMINISH AND BECOME WEST BEHIND THE LOWS COLD FRONT MONDAY. WINDS BACK TO SOUTH AHEAD OF THE NEXT LOW TUESDAY AND INCREASE TO 15-25 KT WEDNESDAY. THE LOW IS PROGGED TO PASS JUST NORTHWEST AND NORTH OF THE LAKE THURSDAY NIGHT INTO FRIDAY WITH SOUTH WINDS INCREASING TO AT LEAST 30 KT THURSDAY BECOMING WEST 20-25 KT BEHIND THE LOW. SOME GUIDANCE MEMBERS DO SUGGEST WE COULD HAVE GALES THURSDAY. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ022 UNTIL 3 PM SATURDAY. WINTER WEATHER ADVISORY...ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 3 PM SATURDAY. IN...WINTER STORM WARNING...INZ001-INZ002 UNTIL 6 PM SATURDAY. WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019 UNTIL 6 PM SATURDAY. LM...GALE WARNING...ILLINOIS NEARSHORE WATERS UNTIL 9 PM SATURDAY. SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 PM SATURDAY TO 9 AM SUNDAY. GALE WARNING...LMZ743-LMZ744-LMZ745-LMZ777-LMZ779...3 PM SATURDAY TO 3 AM SUNDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 3 PM SATURDAY. && $$ 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...UPDATED
NWS CHICAGO/ROMEOVILLE IL
917 AM CST SAT NOV 21 2015 .UPDATE... 915 AM CST ONLY CHANGE TO HEADLINES WAS TO UPGRADE ADVISORY TO A WINTER STORM WARNING FOR LAKE AND PORTER COUNTIES IN NORTHWEST INDIANA. MAJORITY OF FORECAST CONTINUES WELL ON TRACK...INCLUDING FOR THE MOST PART SNOWFALL TOTALS AND ENDING TIMES TODAY. THE WELL-DEFINED TROUGH ON SATELLITE THIS MORNING IS SWINGING INTO THE AREA...PIVOTING SLIGHTLY MORE NEGATIVELY TILTED...WITH RAPID MID-LEVEL AND DYNAMIC COOLING. AN IMPRESSIVE 500MB TEMPERATURE DIFFERENCE FROM MPX TO DVN OF 16C HIGHLIGHTS THAT. THE SURFACE TEMPERATURES ARE STARTING TO SLOWLY FALL IN NORTH CENTRAL ILLINOIS WITH NORTHERLY WINDS. TEMPERATURES ARE ALSO BEGINNING TO SLOWLY COOL NEAR THE IMMEDIATE LAKE SHORE OF NORTHEAST ILLINOIS...INCLUDING DOWNTOWN CHICAGO...WHERE RAIN OR RAIN/SNOW MIX WITH LITTLE TO NO ACCUMULATION HAS BEEN REPORTED THUS FAR THIS MORNING. EXPECTING TO SEE THESE LOCATIONS TURN OVER TO ALL SNOW FOR GOOD OVER THE NEXT COUPLE HOURS. AS DEFORMATION ENVELOPS THE AREA AS NOTED IN THE PREVIOUS DISCUSSION...WE SHOULD CONTINUE TO SEE HEAVIER SNOW BLOSSOM ON RADAR WHICH WE HAVE NOTICED UNDULATE SINCE 7 AM. AREAS OF HALF MILE AND TEMPORARY QUARTER MILE VISIBILITY HAVE BEEN OBSERVED UNDER THESE. SNOWFLAKE QUALITY...OR SNOW RATIOS...ALSO APPEAR TO INCREASE IN THESE AREAS BASED ON OUT OUR WINDOW AND A FEW OTHER REPORTS. THAT WOULD LINE UP WITH SATURATION PROFILES...ESPECIALLY WHERE THE WINDS ARE LIGHTER IN THE LOW-LEVELS /LESS FLAKE FRAGMENTING/...SUCH AS NORTHEAST ILLINOIS AND FAR NORTHWEST INDIANA AT PRESENT. TEMPORARY ONE INCH PER HOUR RATES WILL BE MOST FAVORED IN THESE AREAS. LAKE ENHANCEMENT CONTINUES TO BE SEEN NEAR THE WI/IL STATE LINE...WITH EVEN SOME 40 MPH GUSTS ON THE IMMEDIATE SOUTHEAST WISCONSIN SHORE LIKELY INDICATING THE PRESENCE OF SHARPENING CONVERGENCE AND STEEP LAPSE RATES. THIS ENHANCEMENT WILL SLOWLY MOVE SOUTHWARD THROUGH EARLY AFTERNOON...WITH THE LONGEST RESIDENCE TIME JUST NORTH OF CHICAGO IT WOULD APPEAR ON THE HRRR AND RAP PREDICTED WIND FIELDS. THIS WILL SHIFT INTO NORTHWEST INDIANA DURING THE MID AFTERNOON OR SO AND FURTHER INCREASE RATES AND TOTAL SNOW. WHILE SNOWFALL TOTALS IN PARTS OF LAKE AND PORTER ARE LIKELY TO NOT REACH SIX INCHES...THE COMBINATION OF THE HEAVIER SYNOPTIC AND EXPECTED LATER MESOSCALE RATES DURING THE DAYTIME...AND THE FIRST EVENT OF THE YEAR...HAVE COLLABORATED THE UPGRADE TO WARNING FOR THERE. MTF && .SHORT TERM... 330 AM CST THROUGH MONDAY... A VERY IMPRESSIVE DYNAMIC EARLY SEASON STORM SYSTEM HAS ONLY PRESENTED ITS FIRST PUNCH TO PORTIONS OF THE AREA. YESTERDAY EVENING...A VERY STRONGLY FRONTOGENTICALLY FORCED HEAVY SNOW BAND DEVELOPED OVER FAR NORTHERN ILLINOIS AND DROPPED UP TO 10 INCHES WITHIN A FEW HOURS. HOWEVER...AREAS FARTHER SOUTH RECEIVED LIGHTER AMOUNTS OUT OF THIS FIRST PERIOD OF SNOW. THIS IS EXPECTED TO CHANGE THIS MORNING...HOWEVER...AS ADDITIONAL MODERATE TO OCCASIONALLY HEAVY BANDS OF SNOW DEVELOP OVER THE AREA AND PRESENT THE OPPORTUNITY FOR AREAS SOUTH OF YESTERDAY EVENINGS HEAVY SNOW EVENT TO GET SNOW ACCUMULATION. THE TRACKS OF THE 850 AND 700 MB LOWS APPEAR QUITE FAVORABLE FOR HEAVY SNOW ACROSS NORTHERN ILLINOIS AND NORTHWESTERN INDIANA TODAY. STRONG Q-VECTOR CONVERGENCE IS EXPECTED TO SET UP OVER THE REGION THIS MORNING AS THE MAIN MID LEVEL SHORT WAVE TRANSITIONS TO A NEGATIVE TILT. THIS SUGGESTS THE PRESENCE OF STRONG LARGE SCALE FORCING FOR ASCENT...ESPECIALLY CONSIDERING THE AREA WILL RESIDE WITHIN THE FAVORABLE LEFT EXIT REGION OF A 120+ KT UPPER LEVEL JET. AS THE LOWER LEVEL LOW SHIFTS EASTWARD OVER ILLINOIS...THIS WILL RESULT IN A CORRIDOR OF RATHER STOUT DEFORMATION...AND THE RESULTANT BANDS OF FRONTOGENESIS SHOULD DIVE AN AREA OF MODERATE...TO OCCASIONALLY HEAVY SNOW OVER THE AREA TODAY. THIS STRONG FORCING FOR ASCENT ALSO LOOKS TO BE COMPLEMENTED...AT LEAST OVER NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA...BY FAVORABLE THERMODYNAMICS FOR LAKE ENHANCEMENT. SURFACE TEMPERATURES HAVE REMAINED AT...OR A COUPLE OF DEGREES ABOVE FREEZING THROUGH THE NIGHT IN MOST AREAS OUTSIDE OF NORTH CENTRAL ILLINOIS...AND THIS HAS RESULTED IN LITTLE SNOW ACCUMULATION...ESPECIALLY CONSIDERING SNOW RATES HAVE REMAINED FAIRLY LIGHT OVERNIGHT. SURFACE TEMPERATURES SHOULD BEGIN TO COOL TO AND BELOW FREEZING DURING THE DAY AS HEAVIER PRECIPITATION RATES DEVELOP...AND THIS SHOULD ALLOW SNOW TO ACCUMULATE...ESPECIALLY ON GRASSY AREAS. IT IS A BIT UNCERTAIN HOW MUCH SNOW WILL ACCUMULATE ON PAVEMENT...DUE TO THE WARMER TEMPERATURES. HOWEVER...AT LEAST SOME SLUSHY ACCUMS LOOKS POSSIBLE. AS MENTIONED ABOVE...THERMODYNAMICS SHOULD BECOME INCREASING FAVORABLE FOR A LAKE ENHANCED BAND OF SNOW TO DEVELOP OVER NORTHEASTERN ILLINOIS AND EVENTUALLY NORTHWESTERN INDIANA. COOLER MID-LEVEL TEMPERATURES MOVING OVER THE AREA SHOULD SET UP THESE FAVORABLE CONDITIONS. HI-RES GUIDANCE IS ACTUALLY PICKING UP ON THIS...AND SUGGESTS THAT A HEAVY LAKE ENHANCED BAND OF HEAVY SNOW WILL IMPACT PORTIONS OF NORTHEASTERN ILLINOIS THIS MORNING. IT APPEARS THAT THE STORM SYSTEM WILL TRACK A BIT FARTHER SOUTH THEN WHAT WAS ANTICIPATED EARLIER. THEREFORE...IT APPEARS THAT AREAS OUTSIDE THE CURRENT ADVISORY COULD END UP GETTING A FEW INCHES OF ACCUMULATION TODAY. BECAUSE OF THIS...WE OPTED TO EXPAND THE WINTER WX ADVISORY FARTHER SOUTH TO COVER THE REST OF MY AREA. OVERALL...IT APPEARS THE HEAVIEST SNOW TODAY WILL FALL DURING THE MORNING...THEN BEGIN TAPERING OFF FROM WEST TO EAST THROUGH THE AFTERNOON. LAKE ENHANCED SNOW SHOWERS COULD LINGER INTO THE EVENING OVER FAR NORTHEASTERN PORTER. OTHERWISE...THINGS SHOULD BE DONE IN MOST AREAS BY LATER THIS AFTERNOON. IT APPEARS THAT AMOUNTS OF 3 TO 7 INCHES COULD FALL ACROSS THE AREA TODAY. THEREFORE...NO CHANGES ARE PLANED TO THE HEADLINES...ASIDE FROM THE EXPANSION MENTIONED. NORTH-NORTHWESTERLY WINDS WILL BECOME VERY GUSTY THIS AFTERNOON AS THE SURFACE LOW TRACKS OVER THE EASTERN GREAT LAKES REGION. THESE STRONGER WINDS COULD PRODUCE SOME BLOWING SNOW. HOWEVER...DUE TO THE WETTER NATURE OF THE SNOW...THIS MAY NOT BE TOO BIG OF AN ISSUE...AND I HAVE OPTED TO LEAVE THE MENTION OUT OF THE FORECAST AT THIS TIME. OTHERWISE...EXPECT A VERY COLD NIGHT TONIGHT WITH THE FRESH SNOW ON THE GROUND. AREAS ACROSS NORTH CENTRAL ILLINOIS LOOK TO DROP INTO THE SINGLE DIGITS...WITH TEENS LIKELY IN MOST OTHER AREAS. SUBFREEZING TEMPERATURES WILL CONTINUE SUNDAY...BEFORE TEMPERATURES BEGIN TO INCH ABOVE FREEZING ON MONDAY. KJB && .LONG TERM... 238 AM CST TUESDAY THROUGH FRIDAY... THE EXTENDED BEGINS QUIETLY WITH HIGH PRESSURE SHIFTING FROM THE SOUTHEAST U.S. TO NEW ENGLAND BY WEDNESDAY MORNING. WINDS TURN SOUTH WEDNESDAY USHERING IN WARMER AIR. THIS IS REFLECTED IN HIGH TEMPS WHICH WILL JUMP FROM THE UPPER 30S TO MID 40S TUESDAY TO THE LOW TO MID 50S THURSDAY. A WEAKENING MID LEVEL SHORTWAVE TROUGH PASSES OVER THE REGION WEDNESDAY BRINGING A SLIGHT CHANCE TO CHANCE OF LIGHT RAIN WITH IT. HAVE MORE CONFIDENCE IN RAIN WEDNESDAY NIGHT THAN WEDNESDAY AS THE NEXT LOW/S WARM FRONT LIFTS NORTH OVER THE REGION...BUT ONLY EXPECTING LIGHT RAIN. THE LOW ARRIVES OVER IOWA THURSDAY MORNING AND CONTINUES NORTHEAST THROUGH LATE IN THE WEEK. THE GFS IS MORE AGGRESSIVE WITH THE RAIN/S PROGRESSION THURSDAY. THINKING AREAS WEST OF I-55 WILL LIKELY SEE RAIN WHILE THE GFS SUGGESTS THE WHOLE WARNING AREA WILL RECEIVE RAIN. GUSTY SOUTH WINDS ARE ALSO EXPECTED THURSDAY WITH GUSTS UP TO 30 MPH. THE LOW/S COLD FRONT SWINGS THROUGH FRIDAY LEADING TO COOLER TEMPS...AN END TO THE RAIN...AND NORTHWEST TO WEST WINDS. HIGH TEMPS FRIDAY WILL STILL BE AROUND TO SLIGHTLY ABOVE AVERAGE RANGING FROM THE MID 40S TO AROUND 50. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * PERIODS OF SNOW THROUGH THE EARLY AFTERNOON WITH VSBYS DROPPING AS LOW AS 1/4SM DURING HEAVIEST PERIODS OF SNOW. * IFR TO LIFR CIGS THROUGH THIS MORNING...IMPROVING TO VFR THIS EVENING. * EAST WINDS LESS THAN 10 KT BECOME NE AND INCREASE TO ARND 10 KT LATE THIS MORNING. WINDS THEN BACK TO NNW AND GUST TO 20-25KT THIS AFTN. JEE/MM //DISCUSSION...UPDATED 12Z... SNOW WILL INCREASE THIS MORNING WITH 3/4 SM VSBY EXPECTED AT ALL OF THE TAF SITES. PERIODS OF 1/4 SM VSBY ARE NOT OUT OF THE QUESTION ACROSS THE EASTERN TERMINALS. A LAKE EFFECT BAND WILL FORM LATE THIS MORNING AND ROTATE OVER THE EASTERN TERMINALS. 1/4SM WITH HEAVY SNOW IS EXPECTED UNDER THIS BAND ALONG WITH QUICK ACCUMULATIONS. HOWEVER THE BAND WILL BE TRANSIENT SO THE HEAVY SNOW WILL LAST ABOUT AN HOUR OR LESS. RFD WILL NOT BE AFFECTED BY THE BAND AND WILL SEE THE SNOW END FIRST AROUND NOON. EAST WINDS WILL BE LESS THAN 10 KT EARLY THIS MORNING AND INCREASE TO CLOSE TO 10 KT LATE THIS MORNING. WINDS WILL BE BACKING LATE THIS MORNING AND BECOME NORTHWEST GUSTING TO 20-25 KT EARLY THIS AFTN. FLURRIES OR LIGHT SNOW MAY PERSIST PAST 19Z AT THE EASTERN TERMINALS...BUT NOT EXPECTING ANY SIGNIFICANT IMPACT FROM THE LINGERING SNOW. LIFR CIGS WILL LIFT AFTER THE SNOW TO MVFR AND CLEAR OUT THIS EVENING WITH WINDS BECOMING SOUTHWEST SUNDAY MORNING. JEE //ORD AND MDW CONFIDENCE...UPDATED 14Z... * HIGH CONFIDENCE IN SNOW THROUGH THE MORNING WITH PERIODS OF LIFR VSBY UNDER HEAVIEST SNOW BANDS. * MEDIUM-HIGH CONFIDENCE IN OCCURRENCE AND TIMING OF A LAKE EFFECT BAND WITH 1/4SM VSBY. * HIGH CONFIDENCE IN CIG AND WIND TRENDS. JEE/MM //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...VFR. SOUTHWEST WINDS. MONDAY...VFR. WEST WINDS. TUESDAY...VFR. SOUTH WINDS. WEDNESDAY...SCHC-CHC -RA. SOUTH WINDS. THURSDAY...RA LIKELY. MVFR PSBL. GUSTY SOUTH WINDS BECOMING WEST. FRIDAY...CHC RAIN. IMPROVING TO VFR. NORTHWEST WINDS. JEE && .MARINE... 238 AM CST NO CHANGES TO CURRENT SMALL CRAFT ADVISORY AND GALE WARNING. WILL LIKELY NEED ANOTHER GALE HEADLINE FOR THE SOUTHERN HALF OF THE LAKE SUNDAY EVENING AND NIGHT...BUT WILL HOLD OFF ON ISSUING ONE NOW GIVEN THE CURRENT HEADLINES. WINDS WILL BECOME NORTH TO NORTHWEST ACROSS THE LAKE THIS AFTERNOON AS THE LOW PRESSURE SYSTEM CURRENTLY OVER TEXAS MOVES OVER THE OHIO RIVER VALLEY. NW WINDS WILL INCREASE TO GALE FORCE ACROSS THE SOUTHERN HALF OF THE LAKE AND INDIANA NEARSHORE ZONES. WINDS DIMINISH OVERNIGHT AS THE LOW MOVES OVER QUEBEC. HIGH PRESSURE SPREADS OVER THE SOUTHERN MISSISSIPPI VALLEY AND SOUTHEAST U.S. AS ANOTHER LOW SHIFTS SOUTHEAST OVER ONTARIO SUNDAY NIGHT INTO MONDAY. WINDS BACK TO SOUTHWEST AND GALES ARE EXPECTED SUNDAY NIGHT ACROSS THE SOUTHERN HALF OF THE LAKE. WINDS DIMINISH AND BECOME WEST BEHIND THE LOWS COLD FRONT MONDAY. WINDS BACK TO SOUTH AHEAD OF THE NEXT LOW TUESDAY AND INCREASE TO 15-25 KT WEDNESDAY. THE LOW IS PROGGED TO PASS JUST NORTHWEST AND NORTH OF THE LAKE THURSDAY NIGHT INTO FRIDAY WITH SOUTH WINDS INCREASING TO AT LEAST 30 KT THURSDAY BECOMING WEST 20-25 KT BEHIND THE LOW. SOME GUIDANCE MEMBERS DO SUGGEST WE COULD HAVE GALES THURSDAY. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ022 UNTIL 3 PM SATURDAY. WINTER WEATHER ADVISORY...ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 3 PM SATURDAY. IN...WINTER STORM WARNING...INZ001-INZ002 UNTIL 6 PM SATURDAY. WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019 UNTIL 6 PM SATURDAY. LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 9 AM SUNDAY. GALE WARNING...LMZ743-LMZ744-LMZ745-LMZ777-LMZ779...3 PM SATURDAY TO 3 AM SUNDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 3 PM SATURDAY. && $$ 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
608 AM CST SAT NOV 21 2015 .SHORT TERM...(Today) ISSUED AT 336 AM CST SAT NOV 21 2015 the 09z/3am surface analysis shows the center of the low pressure in south-central Missouri, with a warm front extending across southern IL, roughly along I-70. The rain-snow line has maintained farther north...with snow remaining north of a line from Macomb to Peoria to Pontiac. The Peoria airport just SW of Peoria has little to no snow, while the north side of Peoria has what looks to be at least an inch of snow, and possibly more, on grassy surfaces based on IDOT cameras. Reports of 2.5" of snow have come in from Knox county observers in Altona and Abingdon earlier tonight. The RAP and HRRR take the surface low across southern IL, with deformation band snows continuing in our NW counties. Cold air along the northern edge of the system will gradually get pulled southward into our counties, prompting the rain to change to snow progressively farther south and east. Snowfall amounts look on track for our NW counties to be in the 3 to 6 inch range, with a sharp cutoff down to an inch or less. As the deformation band progresses across central IL into the afternoon, our NE counties could see snowfall amounts up to an inch or possibly a little more toward Hoopeston. We did not expand the winter weather advisory eastward, as snow amounts should remain enough below the 3" criteria for Champaign and Vermilion counties. The southern row of counties of our advisory (Fulton, Tazewell, McLean) will be borderline in terms of snow amounts as well, but will continue with headlines unchanged as there remains some uncertainty as to how soon the cold air will surge southward to change rain to snow, and how efficient of snowfall production will occur in our NW areas. Temps will remain warm enough for rain south of I-72 for a majority of the day, with any change to snow coming so late in the event that little to no snow accumulation is expected south of there. The center of the surface low is forecast to pull into Indiana by 11 am/17z, so cold air will invade on strong NW winds by early afternoon. High temps will likely occur by Noon in most areas because of that, with steady or falling temps this afternoon as winds increase to 25-30 mph. The snow should generally be too wet to blow around, but wind chills could drop into the teens in our W-NW counties. .LONG TERM...(Tonight through Friday) ISSUED AT 336 AM CST SAT NOV 21 2015 Strong short wave to lift ne of central IL early this evening with Canadian high pressure over the central Rockies quickly ridging east into the mid MS river valley by dawn Sunday. Clouds to decrease from west to east later this afternoon and into the evening while nw winds 15-25 mph at sunset today diminish to 5-10 mph overnight. Diminishing clouds and winds to bring a very cold night to the area especially over northern CWA where snow cover where lows will be 7- 13F with mid teens over central parts of CWA and upper teens to near 20F in southeast IL. Wind chills will lower to 5 above to 5 below zero northern cwa and 10-15 southeast IL. This will be the coldest night since March 6th over central IL. High pressure ridges into the Ohio river valley by sunset Sunday while upper level trof axis shifts east of IL. A mostly sunny but cold day with highs ranging form lower 30s from i-74 ne, mid 30s central CWA and upper 30s sw CWA. Winds to become ssw at 7-14 mph by Sunday afternoon. After a taste of winter weather this weekend for IL, temperatures to moderate back above normal during the upcoming work week with upper level heights rising over the region and nearly zonal upper level flow Monday becoming sw by mid week with strong upper level ridge in the east and strong upper level low/trof digging in the western states. Dry weather expected Monday through Wednesday with temps warming back up. Lows Sunday night in the mid to upper 20s. Highs Monday range from lower 40s from I-74 ne where remaining snow cover likely to melt while upper 40s to near 50F sw CWA. Highs by Wed in the low to mid 50s and mid to upper 50s on Thanksgiving day. 00Z models have trended slower with qpf returning to IL Wed night and Thu and looks like a wet period from Wed night into early Sat. GFS is quicker than ECMWF model with cold front moving through later Thu night and Friday with highest pops will likely be. Between 1 and 2 inches of rain appear possible during this time frame. Rain chances diminish next weekend and colder air returns to central/se IL. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) ISSUED AT 600 AM CST SAT NOV 21 2015 Conditions are expected to continue at IFR or LIFR for PIA and BMI where snow will fall through the morning and into early afternoon. IFR conditions will develop at SPI, DEC and CMI as the morning progresses, as rain changes to snow. Low pressure will pass south of the area this morning, roughly just south of I-70. The low will move into Indiana before Noon/18z, causing winds to shift to the NE, then N, then NW by afternoon for all TAF sites. Wind speeds will increase to 15 to 20kt after 15z, with gusts to 30kt at times this afternoon. Winds will diminish to 8-12kt after 00z. Initially, surface temps will hover right around or just above freezing early this morning for a few hours. Ground temperatures are generally above freezing, so snow accumulation on travel surfaces will remain lower than grassy areas. 1 inch of slushy accumulation could occur at PIA, with less than an inch at BMI and CMI, and little to no snow accumulation at DEC and SPI. IFR conditions should gradually improve to MVFR during the afternoon and then to VFR after 00-03z. && .ILX Watches/Warnings/Advisories... Winter Weather Advisory until noon CST today for ILZ027>031- 036>038. && $$ SHORT TERM...Shimon LONG TERM...07 AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
336 AM CST SAT NOV 21 2015 .SHORT TERM...(Today) ISSUED AT 336 AM CST SAT NOV 21 2015 the 09z/3am surface analysis shows the center of the low pressure in south-central Missouri, with a warm front extending across southern IL, roughly along I-70. The rain-snow line has maintained farther north...with snow remaining north of a line from Macomb to Peoria to Pontiac. The Peoria airport just SW of Peoria has little to no snow, while the north side of Peoria has what looks to be at least an inch of snow, and possibly more, on grassy surfaces based on IDOT cameras. Reports of 2.5" of snow have come in from Knox county observers in Altona and Abingdon earlier tonight. The RAP and HRRR take the surface low across southern IL, with deformation band snows continuing in our NW counties. Cold air along the northern edge of the system will gradually get pulled southward into our counties, prompting the rain to change to snow progressively farther south and east. Snowfall amounts look on track for our NW counties to be in the 3 to 6 inch range, with a sharp cutoff down to an inch or less. As the deformation band progresses across central IL into the afternoon, our NE counties could see snowfall amounts up to an inch or possibly a little more toward Hoopeston. We did not expand the winter weather advisory eastward, as snow amounts should remain enough below the 3" criteria for Champaign and Vermilion counties. The southern row of counties of our advisory (Fulton, Tazewell, McLean) will be borderline in terms of snow amounts as well, but will continue with headlines unchanged as there remains some uncertainty as to how soon the cold air will surge southward to change rain to snow, and how efficient of snowfall production will occur in our NW areas. Temps will remain warm enough for rain south of I-72 for a majority of the day, with any change to snow coming so late in the event that little to no snow accumulation is expected south of there. The center of the surface low is forecast to pull into Indiana by 11 am/17z, so cold air will invade on strong NW winds by early afternoon. High temps will likely occur by Noon in most areas because of that, with steady or falling temps this afternoon as winds increase to 25-30 mph. The snow should generally be too wet to blow around, but wind chills could drop into the teens in our W-NW counties. && .LONG TERM...(Tonight through Friday) ISSUED AT 336 AM CST SAT NOV 21 2015 Strong short wave to lift ne of central IL early this evening with Canadian high pressure over the central Rockies quickly ridging east into the mid MS river valley by dawn Sunday. Clouds to decrease from west to east later this afternoon and into the evening while nw winds 15-25 mph at sunset today diminish to 5-10 mph overnight. Diminshing clouds and winds to bring a very cold night to the area especially over northern CWA where snow cover where lows will be 7- 13F with mid teens over central parts of CWA and upper teens to near 20F in southeast IL. Wind chills will lower to 5 above to 5 below zero northern cwa and 10-15 southeast IL. This will be the coldest night since March 6th over central IL. High pressure ridges into the Ohio river valley by sunset Sunday while upper level trof axis shifts east of IL. A mostly sunny but cold day with highs ranging form lower 30s from i-74 ne, mid 30s central CWA and upper 30s sw CWA. Winds to become ssw at 7-14 mph by Sunday afternoon. After a taste of winter weather this weekend for IL, temperatures to moderate back above normal during the upcoming work week with upper level heights rising over the region and nearly zonal upper level flow Monday becoming sw by mid week with strong upper level ridge in the east and strong upper level low/trof digging in the western states. Dry weather expected Monday through Wednesday with temps warming back up. Lows Sunday night in the mid to upper 20s. Highs Monday range from lower 40s from I-74 ne where remaining snow cover likely to melt while upper 40s to near 50F sw CWA. Highs by Wed in the low to mid 50s and mid to upper 50s on Thanksgiving day. 00Z models have trended slower with qpf returning to IL Wed night and Thu and looks like a wet period from Wed night into early Sat. GFS is quicker than ECMWF model with cold front moving through later Thu night and Friday with highest pops will likely be. Between 1 and 2 inches of rain appear possible during this time frame. Rain chances diminish next weekend and colder air returns to central/se IL. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) ISSUED AT 1055 PM CST FRI NOV 20 2015 Conditions are expected to deteriorate to IFR at all sites after 09z as a storm system tracks across the region. Low pressure will pass south of the area on Saturday insuring a changeover to snow at the TAF sites with PIA first in the 06-08z time frame...and then over to BMI by 09z with CMI the last to see the change to snow. Initially, surface temps will be above freezing but should edge close to or just below freezing for a few hours Saturday morning when we should see the steadier snowfall that will accumulate. IFR conditions should gradualliy improve to MVFR during the afternoon and then to VFR by 00z. Southeast to east winds of 10 to 15 kts will back into the northeast and then north by morning with speeds increasing to 15 to 25 kts during the morning, and then continue into the afternoon. Gusts around 30 kts will be possible at times as well before we see northwest winds diminish to around 10 kts around 00z. && .ILX Watches/Warnings/Advisories... Winter Weather Advisory until noon CST today for ILZ027>031- 036>038. && $$ SHORT TERM...Shimon LONG TERM...07 AVIATION...Smith
AREA FORECAST DISCUSSION
NWS GOODLAND KS
506 AM MST SAT NOV 21 2015 .UPDATE... ISSUED AT 456 AM MST SAT NOV 21 2015 SMALL AREA OF FLURRIES MOVING THROUGH THE SOUTHWEST QUADRANT OF THE AREA AT THIS TIME. HRRR DOES CATCH THIS SMALL AREA. SO ADDED SCATTERED FLURRIES TO THE ABOVE MENTIONED AREA FOR THE NEXT FEW HOURS. ALSO INCREASED SKY COVER TO CATCH CURRENT SATELLITE AND SURFACE OBSERVATION TRENDS. && .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 210 AM MST SAT NOV 21 2015 MAIN FORECAST PROBLEM WILL BE TEMPERATURES. SATELLITE SHOWING A SOMEWHAT AMPLIFIED BUT STILL PROGRESSIVE FLOW FROM THE PACIFIC INTO THE WESTERN ATLANTIC. AT JET LEVEL...THE ECMWF STARTED OUT BETTER THAN THE REMAINING OUTPUT. AT MID LEVELS...ALL MODELS STARTED OUT WELL WITH MAYBE THE GFS/CANADIAN/UKMET HAVING AN EVER SO SLIGHT ADVANTAGE. THE ECMWF WAS DOING A LITTLE BETTER ON THE SURFACE WIND AND PRESSURE FIELD. THE ECMWF WAS DOING A LITTLE BETTER THAN THE GFS/CANADIAN ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...AREA REMAINS IN SUBSIDENCE FROM UPPER JET AS MID LEVEL RIDGE BUILDS IN. COLD AND DRY AIR POURING INTO THE AREA. SATELLITE STILL SHOWING A NARROW BUT SUBSTANTIAL SNOWFIELD FROM THE SOUTHWEST CORNER TO NEAR THE NORTHEAST CORNER. BIG DIFFERENCES IN TEMPERATURES BETWEEN WHERE THERE IS NO SNOW AND THIS SNOW FIELD. SIGNIFICANT CLEARING SHOULD OCCUR. CONSIDERING THE CHANGE IN AIR MASS AND YESTERDAYS TEMPERATURES...MADE ONLY SLIGHT ADJUSTMENTS TO THE TEMPERATURES WITH THE COOLEST IN THE SNOWFIELD. LIGHT WESTERLY WINDS TONIGHT. SO WOULD EXPECT THE SNOWFIELD AND LOCATIONS JUST DOWNSTREAM OF THE SNOWFIELD TO BE THE COLDEST. SUNDAY/SUNDAY NIGHT...SUBSIDENCE AND RIDGING CONTINUE/STRENGTHENS ACROSS THE AREA. AIR MASS WARMS AND DO HAVE DOWNSLOPE WINDS OVER THE ENTIRE AREA. HOWEVER THOSE WINDS LOOK TO BE BLOWING ALONG THE LENGTH OF THAT SNOWFIELD. NOT SURE HOW MUCH THE AIR MASS WILL BE MODIFIED...ESPECIALLY IN THE SNOWFIELD. TENDED TO WARM TEMPERATURES FROM THE PREVIOUS FORECAST IN LOCATIONS THAT WILL NOT BE AFFECTED BY THE SNOWFIELD. MADE LITTLE TO NO ADJUSTMENTS FOR THE SNOWFIELD AFFECTED AREAS. WINDS LOOK TO BE A LITTLE STRONGER DURING THE NIGHT WITH MORE WARM AIR ADVECTION OCCURRING. SO TEMPERATURES WARMER AND MORE UNIFORM. MONDAY/MONDAY NIGHT...WEAK RIDGING/ZONAL FLOW ALOFT IS OVER THE REGION. MODELS ARE IN DISAGREEMENT IN WHAT TO DO WITH THE WIND FIELD. IT IS ALMOST LIKE SOME OF THE MODELS PUSH A WEAK BOUNDARY INTO THE AREA. OVERALL THE WIND FIELD LOOKS LIGHT WHICH IS NOT CONDUCIVE TO A BIG WARMUP. THIS COMBINED WITH THE SNOWFIELD MAKES THE TEMPERATURES A LITTLE MORE DIFFICULT. AGAIN ONLY MADE SLIGHT ADJUSTMENTS TO THE HIGH TEMPERATURES. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 145 AM MST SAT NOV 21 2015 TUESDAY-WEDNESDAY...CLOSED UPPER LOW DEEPENING OVER THE WESTERN US RESULTS IN DEEP SW FLOW ACROSS OUR CWA AND GOOD WAA. DEEP DRY AIR MASS WILL PREVENT ANY SHOWER/THUNDERSTORM DEVELOPMENT DESPITE INCREASING INSTABILITY AND WEAK SHORTWAVE TROUGHS EMBEDDED WITHIN SW FLOW. CURRENTLY EXPECTED THESE PERIOD TO REMAIN DRY WITH ABOVE NORMAL TEMPERATURES BOTH DAYS. I CONTINUED TO ACCOUNT FOR SNOW FIELD...THOUGH ITS IMPACT SHOULD CONTINUE TO DECREASE AS FURTHER MELTING OCCURS SUNDAY/MONDAY. WEDNESDAY NIGHT-THURSDAY...MESSY AND COLD WEATHER PATTERN POSSIBLE FOR THANKSGIVING AS UPPER LOW BEGINS TO SHIFT EASTWARD AND ARCTIC FRONT DROPS SOUTH ACROSS THE PLAINS. EXPERIENCE WITH SIMILAR EVENTS LEADS ME TO FAVOR FASTER FRONTAL TIMING AND COLDER TEMPERATURES...AND I TRENDED THIS WAY. WITH EXTENSIVE CLOUD COVER/POSSIBLE PRECIPITATION WE MAY NOT SEE HIGHS OUT OF THE TEENS. IT IS STILL FAR ENOUGH OUT THAT I ONLY MADE INCREMENTAL ADJUSTMENTS DOWNWARD ON TEMPERATURES FROM CONSENSUS BLEND. MODELS ARE SHOWING BEST PRECIP SIGNAL WED NIGHT THROUGH THURSDAY. TEMPERATURE/MOISTURE PROFILES WED NIGHT AND THURSDAY FAVOR A MIX OF FREEZING RAIN (MAYBE A SHORT PERIOD OF SLEET) WITH SATURATED LAYER ABOUT 3-5KFT DEEP 0C TO -8C UNTIL AROUND SUNSET THURSDAY. AS I MENTIONED...I COULD SEE BL TEMPS COOLER THAN PROJECTED AND THIS MIGHT FAVOR A TRANSITION TO MAINLY SNOW EARLIER ACROSS THE NORTH/NORTHWEST. I KEPT MENTION OF FREEZING DRIZZLE/SNOW WHERE DEEPER COLD LAYER IS MOST LIKELY WITH RAIN/FREEZING RAIN IN OUR SOUTH/SOUTHEAST. AT THIS TIME IT APPEARS ANY ACCUMULATIONS SHOULD BE LIGHT IF WE DO SEE ICE OR SNOW. CONDITIONS WILL BE SLICK AND COLD EITHER WAY THOUGH...SO WE WILL NEED TO CONTINUE MONITORING THIS AS WE MAY END UP NEEDING SOME FLAVOR OF ADVISORY. FRIDAY...EVOLUTION OF UPPER LOW AND EROSION OF SHALLOW COLD AIR MASS IS LESS CERTAIN DURING THESE PERIODS AND MODELS ARE SHOWING MUCH MORE VARIANCE IN HEIGHT PATTERNS AND A LESS CONSISTENT PRECIP SIGNAL. THERE IS SIGNIFICANT ENSEMBLE SPREAD WITH GEFS. DETERMINISTIC GUIDANCE ISNT ANY BETTER WITH ECMWF SHOWING CLOSED LOW REMAINING WEST AND LARGE SCALE TROUGH ELONGATING ACROSS THE PLAINS...WHILE GFS/GEM BOTH BREAK DOWN CLOSED CENTER AND PROGRESS THIS UPPER LOW QUICKLY ACROSS THE PLAINS. EITHER SOLUTION WILL FAVOR COLD TEMPERATURES FRIDAY...HOWEVER THESE VARIANCES DO LEAD TO LESS CONFIDENCE IN PRECIP CHANCES BEYOND THURSDAY NIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 456 AM MST SAT NOV 21 2015 FOR KGLD...FLURRIES WITH MVFR CEILINGS WILL OCCUR THROUGH THE FIRST COUPLE HOURS OF THE FORECAST. AFTER THAT...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NORTHWEST WINDS AT 5 TO AROUND 10 KNOTS WILL GRADUALLY SHIFT TO THE WEST AND SOUTHWEST THROUGH THE PERIOD. FOR KMCK...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NORTHWEST WINDS OF 5 TO NEAR 10 KNOTS WILL GRADUALLY SHIFT TO THE WEST AND SOUTHWEST THROUGH THE PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...BULLER LONG TERM...DR AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1037 PM EST SUN NOV 22 2015 .SYNOPSIS... LOW PRESSURE WILL DEVELOP ALONG A STATIONARY FRONT EAST OF THE REGION TONIGHT AND MOVE NORTHEAST MONDAY TOWARD NOVA SCOTIA. HIGH PRESSURE WILL BUILD TOWARD THE REGION MON NIGHT INTO TUE. && .NEAR TERM /THROUGH MONDAY/... 1040 PM UPDATE... QUICK UPDATE TO GRIDS TO WARM T/TD VALUES AS THEY RMN SLOW TO FALL. PER LATEST HRRR DATA 0C 925MB TEMP LINE IS DOWN TO HUL AS OF 04Z AND EXPECT THEY WL BEGIN TO SWITCH OVER TO SNOW BTWN 05 AND 06Z PER LATEST HRRR SNDG. INTERESTING TO NOTE THAT BGR IS REPORTING RA/SN BUT NO OTHER STATION AROUND THEM IS. THINK THAT CURRENT FCST IS STILL ON TRACK SO JUST MADE MINOR TWEAKS TO WX GRIDS WITH NO REAL CHANGE IN OVERALL THINKING. PREV DISCUSSIONS BLO... 850 PM UPDATE... SFC LOW CURRENTLY SITTING OFF OF THE VIRGINIA CAPES AND RIDING UP ALONG FRONTAL BOUNDARY JUST OFFSHORE. FAIRLY TIGHT GRADIENT EXISTS BTWN PCPN AND NO PCPN AS EXPECTED WITH HUL HVG RAIN AND PQI NOTHING IN THE WAY OF PCPN. RADAR POPUP SKEW T IS SHOWING HUL ISOTHERMAL FROM ABOUT 900MB UP WITH BLYR ABV ZERO ALL THE WAY BACK TO ALLAGASH. THIS AGREES WELL WITH LATEST HRRR DATA THUS HV ADJUSTED WX GRIDS BASED ON HRRR FCST DATA THRU THE MRNG. EXPECT THAT PCPN WL BE HIT AND MISS IN NATURE FROM ABOUT PQI NORTHWARD BUT IF IT CAN GET THIS AFTN NORTH IT SHOULD NOT BEGIN TO MIX WITH SNOW UNTIL CLOSE TO 03Z. PCPN SHUD GRADUALLY SPREAD NORTH AFT ABOUT 05Z AS LOW TRACKS CLOSER TO GULF OF MAINE IN COMBINATION WITH RFQ OF H3 SPEED MAX GETTING EVER CLOSER TO CWA. THIS WL BRING THE BEST CHC FOR ACCUMULATING SNOW FOR NORTHERN AREAS BFR DAYBREAK. AT THIS TIME IT APPEARS THAT QPF AMNTS WL BE LIGHT FOR NRN ZONES AND WL BE HARD-PRESSED TO SEE MORE THAN AN INCH OF SNOW AND SLEET FOR AREAS NORTH OF A MILLINOCKET TO HOULTON LINE. THUS WL CONTINUE WITH MENTION OF AMNTS UP TO AN INCH BY MRNG. FURTHER TO THE SOUTH HV LOWERED STORM TOTAL SNOW AMNTS BY ARND AN INCH AS IT APPEARS THAT CLD AIR WL TAKE LONGER TO WRAP IN BHND LOW ESPECIALLY ALONG THE COAST. HWVR, WL CONT WITH WINTER WX ADVISORY AS STILL EXPECTING WIDESPREAD 1-4 INCHES ON TOP OF SLEET THAT FALLS. ALL THIS WL FALL ON ALREADY WET ROADWAYS WHICH WL QUICKLY ICE OVER AS TEMPS FALL DRG THE DAY TOMORROW. HIGHEST SNOW TOTALS LOOK TO OCCUR ACRS NRN WASHINGTON CNTY AS WELL AS PARTS OF SE AROOSTOOK CNTY. PREV DISCUSSION BLO... LONGER RANGE MODELS HAVE COME INTO BETTER CONSENSUS FOR THIS AFTN`S FCST UPDATE REGARDING THE COASTAL LOW EVENT MOVG NE FROM OFF THE MID ATLC STATES TNGT TOWARD THE CNTRL NOVA SCOTIA MON AFTN. THE 12Z DTMNSTC ECMWF BACKED OFF FROM BEING FURTHER N LIKE THE PRIOR 00Z ECMWF RUN...BOTH WITH THE PSN OF THE SFC LOW AND HEAVIER QPF FURTHER N INTO CNTRL AND NRN PTNS OF THE FA. THE FURTHER SE TRACK OF THE 12Z GFS AND CANGEM MODELS SEEMS TO BE INITIALLY VERIFYING BASED ON THE TRAJECTORIES OF THE WRN EDGE OF RADAR REF MOVG INTO THE MID COAST AND DOWNEAST PTNS OF ME LATE THIS AFTN. BASED ON THE CURRENT FCST OF THE LOW TRACK...MILD AIR CURRENTLY OVR THE FA WILL BE REPLACED BY SIG COLDER AIR MOVG E FROM QB AS THE LOW HELPS ADVECT IT SE INTO OUR FA LATER TNGT INTO MON MORN. TEMPS WILL FALL FAIRLY QUICKLY...FIRST ACROSS THE NW HLF LATER THIS EVE THEN SPREADING SE THRU THE REST OF THE FA LATE TNGT INTO MON MORN...RESULTING IN PRECIP CHGNG FROM RN TO SN NW TO SE ACROSS THE FA DURG THIS TM...PERHAPS ACCOMPANIED BY A BRIE PD OF SLEET BASED ON SREF PRECIP TYPES AND FCST SOUNDINGS. THE TRICKY PART OF THIS FCST WILL BE OVR E CNTRL AND DOWNEAST PTNS OF THE FA WHERE SIG PRECIP RATES MAY STILL BE GOING ON WHEN TEMPS APCH OR FALL BELOW FZG...MEANING LCTNS CHGNG TO SNOW LATEST TNGT N OF THE IMMEDIATE DOWNEAST COAST COULD RECEIVE THE MOST SN DUE TO GREATER REMAINING QPF LEFT WITH THIS EVENT. SPEAKING OF QPF... STORM TOTAL QPF WILL RANGE FROM NEAR ZERO OVR THE FAR NW TO NEARLY 2.00 INCHES OVR THE EXTREME SE. FOR NOW...OUR OFFICIAL MAX SNFL TOTALS ARE 3 TO 5 INCHES OVR NRN AND CNTRL WASHINGTON COUNTIES WITH LESSER AMOUNTS ELSEWHERE...BUT GIVEN UNCERTAINTIES OF CHGOVR TM AND POTENTIAL INTENSITY OF SNFL AFT THE CHGOVR...CONFIDENCE WITH MAX AMOUNTS OVR THIS PTN OF THE FA IS NOT HIGH WITH SIG MORE OR LESS POSSIBLE. LATER SHIFTS WILL NEED TO MONITOR OBSVD AND MODEL TRENDS WITH THIS EVENT. IN ANY EVENT...SN WILL TAPER TO SCT SN SHWRS N AND RN/SN SHWRS CNTRL AND DOWNEAST MON AFTN AND THEN END BY LATE IN THE DAY. BOTH LOWS TNGT AND HI TEMPS MON WILL BE COLDER...SPCLY OVR CNTRL AND DOWNEAST PTNS OF THE FA. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... THE SHORT TERM WILL FEATURE FAIR WEATHER UNDER A BUILDING RIDGE, THOUGH AT LEAST TUE WILL BE A BIT COOLER THAN NORMAL. AT THE BEGINNING OF THE SHORT TERM, THE BULK OF THE PRECIP IS EXPECTED TO HAVE DEPARTED TO THE EAST. HOWEVER, WITH THE BASE OF THE UPR TROF SWINGING OVER THE AREA MON NIGHT, CAN`T RULE OUT SOME LINGERING CLOUDS AND A FEW LIGHT SN SHWRS IN THE FAR NRN CWA, AS WAS REFLECTED IN A FEW MODELS. BEYOND THAT, HIGH PRESSURE AND RIDGING TUE THRU WED WILL BRING PARTLY TO MOSTLY SUNNY SKIES TO THE STATE. COLD AIR DRAWN IN BEHIND THE LOW MON NIGHT AND GOOD RADIATIONAL COOLING WILL SET THE STAGE FOR SOME OF THE COLDEST TEMPS IN THE CWA THUS FAR THIS COLD SEASON MON AND TUE NIGHTS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE WILL GRADUALLY SLIDE OFF THE EAST COAST THURSDAY, KEEPING CONDITIONS DRY FOR THANKSGIVING DAY. THIS WILL ALSO PLACE THE REGION UNDER SOUTHWEST FLOW ON THE BACKSIDE OF THE HIGH, ALLOWING TEMPERATURES TO WARM INTO THE MID AND UPPER 40S. HOWEVER, LOW PRESSURE MOVING BY TO OUR NORTH WILL SLOWLY DRAG A COLD FRONT EASTWARD ACROSS THE EASTERN US/CANADA THURSDAY NIGHT THROUGH FRIDAY. THERE`S SOME DISAGREEMENT AMONGST THE LONGER-RANGE MODELS ON THE EXACT TIMING OF THIS FRONT AND ITS PRECIPITATION, BUT THE HIGHEST THREAT FOR FRONTAL PASSAGE LOOKS TO OCCUR SOMETIME LATE FRIDAY THROUGH SATURDAY. IF THE FRONT HOLDS OFF UNTIL FRIDAY NIGHT, EXPECT WE`LL SEE VERY MILD TEMPERATURES FOR THE DAY AFTER THANKSGIVING AS HIGHS TOP OUT IN THE UPPER 40S TO LOWER 50S. HOWEVER, IF THE FRONT MOVES THROUGH A LITTLE FASTER (SIMILAR TO THE GFS SOLUTION), NORTHERN MAINE MAY HAVE A COOLER AND WETTER FRIDAY THAN IS CURRENTLY IN THE FORECAST. REGARDLESS, EXPECT MUCH COLDER AIR WILL MOVE IN BEHIND THE FRONT. SUNDAY LOOKS TO BE THE COLDEST DAY OF THE WEEKEND AT THE MOMENT, WITH HIGHS ONLY IN THE 20S IN THE NORTH, AND LOWS IN THE TEENS. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... NEAR TERM: IFR EXPECTED NEXT 24 HOURS AT MOST TERMINALS IN RAIN/SNOW. EXCEPTION WILL BE FVE WHERE SITE WILL MOST LIKELY BE AFFECTED BY IFR CIGS WITH PCPN REMAINING TO THE SOUTH. STILL SOME QUESTION AS TO HOW MUCH CAR AND PQI WILL SEE WITH REGARD TO PTYPE AS THEY WILL BE ON NORTHERN EDGE OF PCPN SHIELD. HUL WILL SEE RA/SN MIX AROUND 03Z THEN OVER TO ALL SNOW AFTER 06Z. BGR CAN BE EXPECTED TO BE RA/SN AFTER 04Z THEN SWITCHING TO SNOW BY 08Z. BHB WILL BE LATEST TO SEE CHANGEOVER TO RA/SN BY 09Z AND ALL SNOW AROUND 10Z. BY 18Z MON BHB, BGR AND HUL WILL SEE IMPROVEMENT TO VFR CIGS WITH FVE, CAR AND PQI VFR BY 15Z. NW WINDS WILL BE GUSTY DURING THE DAY AT 15G25KTS. SHORT TERM: ASIDE FROM THE CHC FOR SOME MVFR CIGS AND ISO SN SHWRS FOR KFVE BEFORE 09ZTUE, ALL TERMINALS ARE EXPECTED TO HAVE VFR CIGS AND VIS THROUGH WED EVENING. VFR CONDITIONS WILL THEN CONTINUE THROUGH FRIDAY, THOUGH MVFR CEILINGS WILL BE POSSIBLE AT THE NORTHERN TERMINALS FRIDAY AFTERNOON AS A COLD FRONT APPROACHES FROM THE NORTH. && .MARINE... NEAR TERM: E TO NE WINDS WILL INCREASE TO SCA CRITERIA FOR THE INNER BAY/HARBOR MZ THIS EVE AND GALES (IN GUSTS) OVR THE OUTER MZS LATE TNGT...BACKING TO THE N AS THEY CONTINUE INTO MON. GALES OVR THE OUTER MZS WILL NEED TO BE TRANSITIONED TO AN SCA LATER MON AFTN. KEPT CLOSE TO WW3 WV GUIDANCE FOR FCST WV HTS. SHORT TERM: SCA WIND GUSTS AND SEAS LKLY ONGOING OFFSHORE AT THE START OF THE SHORT TERM. WILL CONTINUE TUE AM BEFORE GRADUALLY DIMINISHING TUE PM AS HIGH PRES BUILDS INTO THE AREA. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY UNTIL 11 AM EST MONDAY FOR MEZ006-011- 015. WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR MEZ016-017- 029-030-032. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST MONDAY FOR ANZ052. GALE WARNING UNTIL 1 PM EST MONDAY FOR ANZ050-051. && $$ NEAR TERM...FARRAR/VJN SHORT TERM...KREDENSOR LONG TERM...HASTINGS AVIATION...FARRAR/VJN/KREDENSOR MARINE...FARRAR/VJN/KREDENSOR
AREA FORECAST DISCUSSION
NWS CARIBOU ME
847 PM EST SUN NOV 22 2015 .SYNOPSIS... LOW PRESSURE WILL DEVELOP ALONG A STATIONARY FRONT EAST OF THE REGION TONIGHT AND MOVE NORTHEAST MONDAY TOWARD NOVA SCOTIA. HIGH PRESSURE WILL BUILD TOWARD THE REGION MON NIGHT INTO TUE. && .NEAR TERM /THROUGH MONDAY/... 850 PM UPDATE... SFC LOW CURRENTLY SITTING OFF OF THE VIRGINIA CAPES AND RIDING UP ALONG FRONTAL BOUNDARY JUST OFFSHORE. FAIRLY TIGHT GRADIENT EXISTS BTWN PCPN AND NO PCPN AS EXPECTED WITH HUL HVG RAIN AND PQI NOTHING IN THE WAY OF PCPN. RADAR POPUP SKEW T IS SHOWING HUL ISOTHERMAL FROM ABOUT 900MB UP WITH BLYR ABV ZERO ALL THE WAY BACK TO ALLAGASH. THIS AGREES WELL WITH LATEST HRRR DATA THUS HV ADJUSTED WX GRIDS BASED ON HRRR FCST DATA THRU THE MRNG. EXPECT THAT PCPN WL BE HIT AND MISS IN NATURE FROM ABOUT PQI NORTHWARD BUT IF IT CAN GET THIS AFTN NORTH IT SHOULD NOT BEGIN TO MIX WITH SNOW UNTIL CLOSE TO 03Z. PCPN SHUD GRADUALLY SPREAD NORTH AFT ABOUT 05Z AS LOW TRACKS CLOSER TO GULF OF MAINE IN COMBINATION WITH RFQ OF H3 SPEED MAX GETTING EVER CLOSER TO CWA. THIS WL BRING THE BEST CHC FOR ACCUMULATING SNOW FOR NORTHERN AREAS BFR DAYBREAK. AT THIS TIME IT APPEARS THAT QPF AMNTS WL BE LIGHT FOR NRN ZONES AND WL BE HARD-PRESSED TO SEE MORE THAN AN INCH OF SNOW AND SLEET FOR AREAS NORTH OF A MILLINOCKET TO HOULTON LINE. THUS WL CONTINUE WITH MENTION OF AMNTS UP TO AN INCH BY MRNG. FURTHER TO THE SOUTH HV LOWERED STORM TOTAL SNOW AMNTS BY ARND AN INCH AS IT APPEARS THAT CLD AIR WL TAKE LONGER TO WRAP IN BHND LOW ESPECIALLY ALONG THE COAST. HWVR, WL CONT WITH WINTER WX ADVISORY AS STILL EXPECTING WIDESPREAD 1-4 INCHES ON TOP OF SLEET THAT FALLS. ALL THIS WL FALL ON ALREADY WET ROADWAYS WHICH WL QUICKLY ICE OVER AS TEMPS FALL DRG THE DAY TOMORROW. HIGHEST SNOW TOTALS LOOK TO OCCUR ACRS NRN WASHINGTON CNTY AS WELL AS PARTS OF SE AROOSTOOK CNTY. PREV DISCUSSION BLO... LONGER RANGE MODELS HAVE COME INTO BETTER CONSENSUS FOR THIS AFTN`S FCST UPDATE REGARDING THE COASTAL LOW EVENT MOVG NE FROM OFF THE MID ATLC STATES TNGT TOWARD THE CNTRL NOVA SCOTIA MON AFTN. THE 12Z DTMNSTC ECMWF BACKED OFF FROM BEING FURTHER N LIKE THE PRIOR 00Z ECMWF RUN...BOTH WITH THE PSN OF THE SFC LOW AND HEAVIER QPF FURTHER N INTO CNTRL AND NRN PTNS OF THE FA. THE FURTHER SE TRACK OF THE 12Z GFS AND CANGEM MODELS SEEMS TO BE INITIALLY VERIFYING BASED ON THE TRAJECTORIES OF THE WRN EDGE OF RADAR REF MOVG INTO THE MID COAST AND DOWNEAST PTNS OF ME LATE THIS AFTN. BASED ON THE CURRENT FCST OF THE LOW TRACK...MILD AIR CURRENTLY OVR THE FA WILL BE REPLACED BY SIG COLDER AIR MOVG E FROM QB AS THE LOW HELPS ADVECT IT SE INTO OUR FA LATER TNGT INTO MON MORN. TEMPS WILL FALL FAIRLY QUICKLY...FIRST ACROSS THE NW HLF LATER THIS EVE THEN SPREADING SE THRU THE REST OF THE FA LATE TNGT INTO MON MORN...RESULTING IN PRECIP CHGNG FROM RN TO SN NW TO SE ACROSS THE FA DURG THIS TM...PERHAPS ACCOMPANIED BY A BRIE PD OF SLEET BASED ON SREF PRECIP TYPES AND FCST SOUNDINGS. THE TRICKY PART OF THIS FCST WILL BE OVR E CNTRL AND DOWNEAST PTNS OF THE FA WHERE SIG PRECIP RATES MAY STILL BE GOING ON WHEN TEMPS APCH OR FALL BELOW FZG...MEANING LCTNS CHGNG TO SNOW LATEST TNGT N OF THE IMMEDIATE DOWNEAST COAST COULD RECEIVE THE MOST SN DUE TO GREATER REMAINING QPF LEFT WITH THIS EVENT. SPEAKING OF QPF... STORM TOTAL QPF WILL RANGE FROM NEAR ZERO OVR THE FAR NW TO NEARLY 2.00 INCHES OVR THE EXTREME SE. FOR NOW...OUR OFFICIAL MAX SNFL TOTALS ARE 3 TO 5 INCHES OVR NRN AND CNTRL WASHINGTON COUNTIES WITH LESSER AMOUNTS ELSEWHERE...BUT GIVEN UNCERTAINTIES OF CHGOVR TM AND POTENTIAL INTENSITY OF SNFL AFT THE CHGOVR...CONFIDENCE WITH MAX AMOUNTS OVR THIS PTN OF THE FA IS NOT HIGH WITH SIG MORE OR LESS POSSIBLE. LATER SHIFTS WILL NEED TO MONITOR OBSVD AND MODEL TRENDS WITH THIS EVENT. IN ANY EVENT...SN WILL TAPER TO SCT SN SHWRS N AND RN/SN SHWRS CNTRL AND DOWNEAST MON AFTN AND THEN END BY LATE IN THE DAY. BOTH LOWS TNGT AND HI TEMPS MON WILL BE COLDER...SPCLY OVR CNTRL AND DOWNEAST PTNS OF THE FA. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... THE SHORT TERM WILL FEATURE FAIR WEATHER UNDER A BUILDING RIDGE, THOUGH AT LEAST TUE WILL BE A BIT COOLER THAN NORMAL. AT THE BEGINNING OF THE SHORT TERM, THE BULK OF THE PRECIP IS EXPECTED TO HAVE DEPARTED TO THE EAST. HOWEVER, WITH THE BASE OF THE UPR TROF SWINGING OVER THE AREA MON NIGHT, CAN`T RULE OUT SOME LINGERING CLOUDS AND A FEW LIGHT SN SHWRS IN THE FAR NRN CWA, AS WAS REFLECTED IN A FEW MODELS. BEYOND THAT, HIGH PRESSURE AND RIDGING TUE THRU WED WILL BRING PARTLY TO MOSTLY SUNNY SKIES TO THE STATE. COLD AIR DRAWN IN BEHIND THE LOW MON NIGHT AND GOOD RADIATIONAL COOLING WILL SET THE STAGE FOR SOME OF THE COLDEST TEMPS IN THE CWA THUS FAR THIS COLD SEASON MON AND TUE NIGHTS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE WILL GRADUALLY SLIDE OFF THE EAST COAST THURSDAY, KEEPING CONDITIONS DRY FOR THANKSGIVING DAY. THIS WILL ALSO PLACE THE REGION UNDER SOUTHWEST FLOW ON THE BACKSIDE OF THE HIGH, ALLOWING TEMPERATURES TO WARM INTO THE MID AND UPPER 40S. HOWEVER, LOW PRESSURE MOVING BY TO OUR NORTH WILL SLOWLY DRAG A COLD FRONT EASTWARD ACROSS THE EASTERN US/CANADA THURSDAY NIGHT THROUGH FRIDAY. THERE`S SOME DISAGREEMENT AMONGST THE LONGER-RANGE MODELS ON THE EXACT TIMING OF THIS FRONT AND ITS PRECIPITATION, BUT THE HIGHEST THREAT FOR FRONTAL PASSAGE LOOKS TO OCCUR SOMETIME LATE FRIDAY THROUGH SATURDAY. IF THE FRONT HOLDS OFF UNTIL FRIDAY NIGHT, EXPECT WE`LL SEE VERY MILD TEMPERATURES FOR THE DAY AFTER THANKSGIVING AS HIGHS TOP OUT IN THE UPPER 40S TO LOWER 50S. HOWEVER, IF THE FRONT MOVES THROUGH A LITTLE FASTER (SIMILAR TO THE GFS SOLUTION), NORTHERN MAINE MAY HAVE A COOLER AND WETTER FRIDAY THAN IS CURRENTLY IN THE FORECAST. REGARDLESS, EXPECT MUCH COLDER AIR WILL MOVE IN BEHIND THE FRONT. SUNDAY LOOKS TO BE THE COLDEST DAY OF THE WEEKEND AT THE MOMENT, WITH HIGHS ONLY IN THE 20S IN THE NORTH, AND LOWS IN THE TEENS. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... NEAR TERM: IFR EXPECTED NEXT 24 HOURS AT MOST TERMINALS IN RAIN/SNOW. EXCEPTION WILL BE FVE WHERE SITE WILL MOST LIKELY BE AFFECTED BY IFR CIGS WITH PCPN REMAINING TO THE SOUTH. STILL SOME QUESTION AS TO HOW MUCH CAR AND PQI WILL SEE WITH REGARD TO PTYPE AS THEY WILL BE ON NORTHERN EDGE OF PCPN SHIELD. HUL WILL SEE RA/SN MIX AROUND 03Z THEN OVER TO ALL SNOW AFTER 06Z. BGR CAN BE EXPECTED TO BE RA/SN AFTER 04Z THEN SWITCHING TO SNOW BY 08Z. BHB WILL BE LATEST TO SEE CHANGEOVER TO RA/SN BY 09Z AND ALL SNOW AROUND 10Z. BY 18Z MON BHB, BGR AND HUL WILL SEE IMPROVEMENT TO VFR CIGS WITH FVE, CAR AND PQI VFR BY 15Z. NW WINDS WILL BE GUSTY DURING THE DAY AT 15G25KTS. SHORT TERM: ASIDE FROM THE CHC FOR SOME MVFR CIGS AND ISO SN SHWRS FOR KFVE BEFORE 09ZTUE, ALL TERMINALS ARE EXPECTED TO HAVE VFR CIGS AND VIS THROUGH WED EVENING. VFR CONDITIONS WILL THEN CONTINUE THROUGH FRIDAY, THOUGH MVFR CEILINGS WILL BE POSSIBLE AT THE NORTHERN TERMINALS FRIDAY AFTERNOON AS A COLD FRONT APPROACHES FROM THE NORTH. && .MARINE... NEAR TERM: E TO NE WINDS WILL INCREASE TO SCA CRITERIA FOR THE INNER BAY/HARBOR MZ THIS EVE AND GALES (IN GUSTS) OVR THE OUTER MZS LATE TNGT...BACKING TO THE N AS THEY CONTINUE INTO MON. GALES OVR THE OUTER MZS WILL NEED TO BE TRANSITIONED TO AN SCA LATER MON AFTN. KEPT CLOSE TO WW3 WV GUIDANCE FOR FCST WV HTS. SHORT TERM: SCA WIND GUSTS AND SEAS LKLY ONGOING OFFSHORE AT THE START OF THE SHORT TERM. WILL CONTINUE TUE AM BEFORE GRADUALLY DIMINISHING TUE PM AS HIGH PRES BUILDS INTO THE AREA. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY UNTIL 11 AM EST MONDAY FOR MEZ006-011- 015. WINTER WEATHER ADVISORY FROM 1 AM TO 1 PM EST MONDAY FOR MEZ016-017-029-030-032. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST MONDAY FOR ANZ052. GALE WARNING FROM 1 AM TO 1 PM EST MONDAY FOR ANZ050-051. && $$ NEAR TERM...FARRAR/VJN SHORT TERM...KREDENSOR LONG TERM...HASTINGS AVIATION...FARRAR/VJN/KREDENSOR MARINE...FARRAR/VJN/KREDENSOR
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1238 PM EST SAT NOV 21 2015 .SYNOPSIS... HIGH PRESSURE WILL CREST OVER THE REGION TODAY. LOW PRESSURE WILL MOVE NORTHWEST OF THE AREA ON SUNDAY WITH SOME RAIN. A SECOND AREA OF LOW PRESSURE WILL LIFT ACROSS THE GULF OF MAINE SUNDAY NIGHT AND THEN INTO THE MARITIMES ON MONDAY WITH MUCH COLDER AIR. && .NEAR TERM /THROUGH TONIGHT/... 1240 PM UPDATE... SKIES ARE GRADUALLY CLOUDING UP ACRS THE NORTH THIS AFTN AS EXPECTED. MOSUNNY SKIES THIS MRNG ALLOWED TEMPS TO CLIMB ABV 40F AT MOST LOCALES ACRS THE NORTH AS OF 17Z THUS HV BUMPED MAXES UP ABOUT 2 DEGREES FOR TDA. NO OTHER CHGS NEEDED WITH THIS UPDATE. PREV DISCUSSION BLO... HIGH PRESSURE WILL BUILD IN FROM THE WEST THIS MORNING WITH CLEARING EARLY TODAY. THE HIGH PRESSURE SYSTEM WILL CREST OVER THE REGION TODAY THEN MOVE OFF TO THE EAST THIS EVENING. WEAK LOW PRESSURE WILL DEVELOP OVER THE GULF OF MAINE BEHIND THE DEPARTING LOW AND SPREAD RAIN AND SNOW INTO NEW BRUNSWICK TONIGHT. INTENSE LOW PRESSURE WILL MOVE INTO THE GREAT LAKES TONIGHT THEN MOVE INTO SOUTHEASTERN QUEBEC PROVINCE EARLY SUNDAY. && .SHORT TERM /SUNDAY THROUGH MONDAY/... AN INTERESTING SETUP FOR SUNDAY NIGHT INTO EARLY MONDAY. A FRONTAL SYSTEM IS FORECAST TO SLIDE ACROSS THE AREA ON SUNDAY W/SOME SHOWERS OR LIGHT RAIN PULLING OUT OF THE AREA IN THE MORNING. THE 2ND BATCH OF PRECIP IN THE FORM OF RAIN IS EXPECTED TO SET UP LATER IN DAY AS LOW PRES DEVELOPS OFF THE SOUTHERN NEW ENGLAND COAST AND LIFTS NNE. THE AREAS THAT WILL SEE MEASURABLE QPF WILL BE ACROSS THE EASTERN 1/2 OF THE CWA WHERE THE BEST FORCING AND LLVL CONVERGENCE WILL BE LOCATED. AS THE LOW LIFTS TO NNE AND THE UPPER TROF DIGS SOME AS IT SWINGS INTO THE NE, COLDER AIR WILL START TO FILTER INTO THE REGION. THE ECMWF AND GFS ARE IN AGREEMENT W/THE COLDER AIR COMING IN BY THE EVENING WHILE THE CANADIAN GEM & NAM HOLD THE COLDER AIR BACK BY 3-6 HRS. DECIDED TO GO W/A CONSENSUS BLEND OF THE GUIDANCE FOR THIS PACKAGE SHOWING RAIN GOING OVER TO A PERIOD OF SNOW BY 11 PM OR SO. ALL THE GUIDANCE IS IN AGREEMENT THAT THE BULK OF THE QPF WILL BE ACROSS THE EASTERN 3RD OF THE CWA SAY FROM FROM HOULTON DOWN INTO HANCOCK AND WASHINGTON COUNTY W/UP AROUND 0.50 INCHES. ATTM, IF THERE IS TO BE ANY SNOWFALL ACCUMULATION, IT WILL BE ACROSS EASTERN WASHINGTON COUNTY W/A SLUSHY INCH POSSIBLE BEFORE THINGS WIND DOWN MONDAY MORNING. TEMPERATURES ARE FORECAST TO DROP DOWN INTO THE LOWER 30S ACROSS EASTERN AREAS AFTER MIDNIGHT W/MID AND UPPER 20S BACK ACROSS THE W AND NW AREAS. THE LOW IS FORECAST TO QUICKLY LIFT ACROSS THE MARITIMES ON MONDAY W/CAA POURING INTO THE REGION AND DRIER CONDITIONS. THERE IS SOME CONCERN THE CLOUDS ACROSS NORTHERN AND EASTERN MAINE MIGHT HANG ON THROUGH MONDAY W/A NNW FLOW COMING IN OFF THE OPEN ST. LAWRENCE. THE GFS SOUNDINGS HINT AT THIS TO BE POSSIBLE W/SOME MOISTURE SHOWING UP BELOW 3000 FT. THIS SETUP SIMILAR TO THIS SCENARIO TOOK PLACE LAST WEEK WHEN A CLOUD DECK BELOW 2500 FT HUNG ON LONGER THAN ANTICIPATED. TEMPERATURES ON MONDAY WILL BE HELD DOWN INTO THE 30S W/CLOUDS AND A NNW WIND OF 10 TO 20 MPH. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A NNW WIND AND CLOUDS LOOK TO HANG ON ESPECIALLY FOR NORTHERN AND EASTERN AREAS MONDAY NIGHT W/CAA CONTINUING TO POUR INTO THE REGION. ANOTHER ITEM TO BE AWARE OF WILL BE POTENTIAL FOR STREAMERS OF LIGHT SNOW FROM THE OPEN ST. LAWRENCE FOR PORTIONS OF NORTHERN AND EASTERN MAINE. THE MODEL GUIDANCE TENDS TO HAVE A DIFFICULT TIME IN PICKING UP THIS MESO-SCALE FEATURE. THE HRRR MODEL AND NAM12 TEND TO CATCH ON AS WE CLOSE IN CLOSER TO THE EVENT. CONTINUED BREEZY AND COLD ON TUESDAY W/SOME PARTIAL CLEARING ACROSS NORTHERN MAINE AS HIGH PRES STARTS TO MOVE IN FROM THE W. DOWNEAST AND THE COAST SHOULD SEE A DECENT AMOUNT OF SUNSHINE. DAYTIME TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL FOR LATE NOVEMBER. STRONG HIGH PRES IS FORECAST TO BUILD ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY AND THEN LIFT TO THE NE INTO THE NW ATLC ON THANKSGIVING DAY. THIS WILL MEAN DRY TRAVEL WEATHER FOR THE THANKSGIVING HOLIDAY W/MODERATING TEMPERATURES. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... NEAR TERM: VFR CONDITIONS THROUGH 06Z TONIGHT THEN CIGS LOWERING TO MVFR RESTRICTIONS AFTER THIS TIME. IFR EXPECTED AT FVE, HUL AND BHB WITH LOW MVFR EXPECTED AT CAR, PQI AND BGR BUT CANNOT RULE OUT THESE TERMINALS WILL DROP TO IFR AT SOME POINT TONIGHT. CONFIDENCE IS LOW SO HAVE NOT INCLUDED IN TAFS. SHORT TERM: IFR/MVFR CONDITIONS FOR SUNDAY W/IFR MAINLY FROM KHUL TO KBHB. MVFR FOR THE REMAINDER OF THE TAF SITES THROUGH SUNDAY EVENING. CONDITIONS EXPECTED TO IMPROVE TO VFR FOR KBGR AND KBHB FRO MONDAY WHILE THE NORTHERN TAF SITES COULD SEE PERIODS OF MVFR CIGS. ATTM, VFR EXPECTED FOR ALL TAF SITES FOR TUESDAY INTO WEDNESDAY && .MARINE... NEAR TERM: FOR SUSTAINED WINDS HAVE USED THE NAM12. FOR WAVES: BUOY OBSERVATIONS INDICATE LONG PERIOD INCOMING SWELL STILL PRESENT FROM SOUTHEASTERLY FETCH EARLY FRIDAY. EXPECT THIS TO SUBSIDE RAPIDLY EARLY TODAY WITH OFF-SHORE WIND WAVE BECOMING THE PREDOMINATE WAVE SYSTEM. SEAS WILL SUBSIDE RAPIDLY TONIGHT ALONG WITH WINDS WITH LONG PERIOD SOUTHEASTERLY WAVE SYSTEM 1-2 FEET/8 SECONDS ONCE AGAIN BECOMING PREDOMINATE. SHORT TERM: LOOKING FOR THE POTENTIAL FOR SCA CONDITIONS TO DEVELOP SUNDAY NIGHT INTO MONDAY ESPECIALLY FOR THE OUTER ZONES. WINDS ARE EXPECTED TO INCREASE TO 15 TO 20 KT W/GUSTS OF 25 KTS AND A SWELL GENERATION TAKING PLACE ALLOWING FOR SEAS TO BUILD TO 5 TO 7 FT. AS A MATTER OF FACT, SCA CONDITIONS COULD HANG ON RIGHT INTO MONDAY AS THE PRES GRADIENT TIGHTENS BETWEEN THE LOW PASSING ACROSS THE MARITIMES AND STRONG HIGH PRES MOVING IN FROM THE W. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...FARRAR/MIGNONE SHORT TERM...HEWITT LONG TERM...HEWITT AVIATION...FARRAR/MIGNONE/HEWITT MARINE...FARRAR/MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
920 AM EST SAT NOV 21 2015 .SYNOPSIS... HIGH PRESSURE WILL CREST OVER THE REGION TODAY. LOW PRESSURE WILL MOVE NORTHWEST OF THE AREA ON SUNDAY WITH SOME RAIN. A SECOND AREA OF LOW PRESSURE WILL LIFT ACROSS THE GULF OF MAINE SUNDAY NIGHT AND THEN INTO THE MARITIMES ON MONDAY WITH MUCH COLDER AIR. && .NEAR TERM /THROUGH TONIGHT/... 920 AM UPDATE... CRYSTAL CLR SKIES ACRS NRN AND SERN ZONES THIS MRNG WITH HIGH CLDS STREAMING NORTH INTO CNTRL SXNS AHD OF S/WV MOVING UP ON SW FLOW. HV GONE WITH MOSUNNY SKIES THIS MRNG FOR NRN SXNS FOR A FEW MORE HRS BUT EXPECT MID-HIGH CLDS TO WORK IN BY LATE MRNG. ADJUSTED GRIDS FOR HRLY T/TD VALUES BUT TEMPS SHUD QUICKLY WARM THIS MRNG. MAY NEED TO BOOST HIGHS A DEGREE OR TWO WITH NEXT UPDATE. NO OTHER CHGS NEEDED AT THIS TIME AS HIPRES WL BUILD EAST INTO AREA THIS AFTN. PREV DISCUSSION BLO... HIGH PRESSURE WILL BUILD IN FROM THE WEST THIS MORNING WITH CLEARING EARLY TODAY. THE HIGH PRESSURE SYSTEM WILL CREST OVER THE REGION TODAY THEN MOVE OFF TO THE EAST THIS EVENING. WEAK LOW PRESSURE WILL DEVELOP OVER THE GULF OF MAINE BEHIND THE DEPARTING LOW AND SPREAD RAIN AND SNOW INTO NEW BRUNSWICK TONIGHT. INTENSE LOW PRESSURE WILL MOVE INTO THE GREAT LAKES TONIGHT THEN MOVE INTO SOUTHEASTERN QUEBEC PROVINCE EARLY SUNDAY. && .SHORT TERM /SUNDAY THROUGH MONDAY/... AN INTERESTING SETUP FOR SUNDAY NIGHT INTO EARLY MONDAY. A FRONTAL SYSTEM IS FORECAST TO SLIDE ACROSS THE AREA ON SUNDAY W/SOME SHOWERS OR LIGHT RAIN PULLING OUT OF THE AREA IN THE MORNING. THE 2ND BATCH OF PRECIP IN THE FORM OF RAIN IS EXPECTED TO SET UP LATER IN DAY AS LOW PRES DEVELOPS OFF THE SOUTHERN NEW ENGLAND COAST AND LIFTS NNE. THE AREAS THAT WILL SEE MEASURABLE QPF WILL BE ACROSS THE EASTERN 1/2 OF THE CWA WHERE THE BEST FORCING AND LLVL CONVERGENCE WILL BE LOCATED. AS THE LOW LIFTS TO NNE AND THE UPPER TROF DIGS SOME AS IT SWINGS INTO THE NE, COLDER AIR WILL START TO FILTER INTO THE REGION. THE ECMWF AND GFS ARE IN AGREEMENT W/THE COLDER AIR COMING IN BY THE EVENING WHILE THE CANADIAN GEM & NAM HOLD THE COLDER AIR BACK BY 3-6 HRS. DECIDED TO GO W/A CONSENSUS BLEND OF THE GUIDANCE FOR THIS PACKAGE SHOWING RAIN GOING OVER TO A PERIOD OF SNOW BY 11 PM OR SO. ALL THE GUIDANCE IS IN AGREEMENT THAT THE BULK OF THE QPF WILL BE ACROSS THE EASTERN 3RD OF THE CWA SAY FROM FROM HOULTON DOWN INTO HANCOCK AND WASHINGTON COUNTY W/UP AROUND 0.50 INCHES. ATTM, IF THERE IS TO BE ANY SNOWFALL ACCUMULATION, IT WILL BE ACROSS EASTERN WASHINGTON COUNTY W/A SLUSHY INCH POSSIBLE BEFORE THINGS WIND DOWN MONDAY MORNING. TEMPERATURES ARE FORECAST TO DROP DOWN INTO THE LOWER 30S ACROSS EASTERN AREAS AFTER MIDNIGHT W/MID AND UPPER 20S BACK ACROSS THE W AND NW AREAS. THE LOW IS FORECAST TO QUICKLY LIFT ACROSS THE MARITIMES ON MONDAY W/CAA POURING INTO THE REGION AND DRIER CONDITIONS. THERE IS SOME CONCERN THE CLOUDS ACROSS NORTHERN AND EASTERN MAINE MIGHT HANG ON THROUGH MONDAY W/A NNW FLOW COMING IN OFF THE OPEN ST. LAWRENCE. THE GFS SOUNDINGS HINT AT THIS TO BE POSSIBLE W/SOME MOISTURE SHOWING UP BELOW 3000 FT. THIS SETUP SIMILAR TO THIS SCENARIO TOOK PLACE LAST WEEK WHEN A CLOUD DECK BELOW 2500 FT HUNG ON LONGER THAN ANTICIPATED. TEMPERATURES ON MONDAY WILL BE HELD DOWN INTO THE 30S W/CLOUDS AND A NNW WIND OF 10 TO 20 MPH. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A NNW WIND AND CLOUDS LOOK TO HANG ON ESPECIALLY FOR NORTHERN AND EASTERN AREAS MONDAY NIGHT W/CAA CONTINUING TO POUR INTO THE REGION. ANOTHER ITEM TO BE AWARE OF WILL BE POTENTIAL FOR STREAMERS OF LIGHT SNOW FROM THE OPEN ST. LAWRENCE FOR PORTIONS OF NORTHERN AND EASTERN MAINE. THE MODEL GUIDANCE TENDS TO HAVE A DIFFICULT TIME IN PICKING UP THIS MESO-SCALE FEATURE. THE HRRR MODEL AND NAM12 TEND TO CATCH ON AS WE CLOSE IN CLOSER TO THE EVENT. CONTINUED BREEZY AND COLD ON TUESDAY W/SOME PARTIAL CLEARING ACROSS NORTHERN MAINE AS HIGH PRES STARTS TO MOVE IN FROM THE W. DOWNEAST AND THE COAST SHOULD SEE A DECENT AMOUNT OF SUNSHINE. DAYTIME TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL FOR LATE NOVEMBER. STRONG HIGH PRES IS FORECAST TO BUILD ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY AND THEN LIFT TO THE NE INTO THE NW ATLC ON THANKSGIVING DAY. THIS WILL MEAN DRY TRAVEL WEATHER FOR THE THANKSGIVING HOLIDAY W/MODERATING TEMPERATURES. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: EXPECT VFR CONDITIONS TODAY AND TONIGHT. SHORT TERM: IFR/MVFR CONDITIONS FOR SUNDAY W/IFR MAINLY FROM KHUL TO KBHB. MVFR FOR THE REMAINDER OF THE TAF SITES THROUGH SUNDAY EVENING. CONDITIONS EXPECTED TO IMPROVE TO VFR FOR KBGR AND KBHB FRO MONDAY WHILE THE NORTHERN TAF SITES COULD SEE PERIODS OF MVFR CIGS. ATTM, VFR EXPECTED FOR ALL TAF SITES FOR TUESDAY INTO WEDNESDAY && .MARINE... UPDATE 0615 AM: HAVE REMOVE SCA FOR ZONES 51 & 52 AND WILL KEEP SCA FOR ZONE 50 UNTIL 15Z. NEAR TERM: FOR SUSTAINED WINDS HAVE USED THE NAM12. FOR WAVES: BUOY OBSERVATIONS INDICATE LONG PERIOD INCOMING SWELL STILL PRESENT FROM SOUTHEASTERLY FETCH EARLY FRIDAY. EXPECT THIS TO SUBSIDE RAPIDLY EARLY TODAY WITH OFF-SHORE WIND WAVE BECOMING THE PREDOMINATE WAVE SYSTEM. SEAS WILL SUBSIDE RAPIDLY TONIGHT ALONG WITH WINDS WITH LONG PERIOD SOUTHEASTERLY WAVE SYSTEM 1-2 FEET/8 SECONDS ONCE AGAIN BECOMING PREDOMINATE. SHORT TERM: LOOKING FOR THE POTENTIAL FOR SCA CONDITIONS TO DEVELOP SUNDAY NIGHT INTO MONDAY ESPECIALLY FOR THE OUTER ZONES. WINDS ARE EXPECTED TO INCREASE TO 15 TO 20 KT W/GUSTS OF 25 KTS AND A SWELL GENERATION TAKING PLACE ALLOWING FOR SEAS TO BUILD TO 5 TO 7 FT. AS A MATTER OF FACT, SCA CONDITIONS COULD HANG ON RIGHT INTO MONDAY AS THE PRES GRADIENT TIGHTENS BETWEEN THE LOW PASSING ACROSS THE MARITIMES AND STRONG HIGH PRES MOVING IN FROM THE W. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ050. && $$ NEAR TERM...FARRAR/MIGNONE SHORT TERM...HEWITT LONG TERM...HEWITT AVIATION...FARRAR/MIGNONE/HEWITT MARINE...FARRAR/MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
623 AM EST SAT NOV 21 2015 .SYNOPSIS... HIGH PRESSURE WILL CREST OVER THE REGION TODAY. LOW PRESSURE WILL MOVE NORTHWEST OF THE AREA ON SUNDAY WITH SOME RAIN. A SECOND AREA OF LOW PRESSURE WILL LIFT ACROSS THE GULF OF MAINE SUNDAY NIGHT AND THEN INTO THE MARITIMES ON MONDAY WITH MUCH COLDER AIR. && .NEAR TERM /THROUGH TONIGHT/... UPDATE 6:15 AM: HAVE ADJUSTED TEMPERATURE AND DEW POINT BASED ON LATEST OBSERVATIONS. NO OTHER CHANGES. HIGH PRESSURE WILL BUILD IN FROM THE WEST THIS MORNING WITH CLEARING EARLY TODAY. THE HIGH PRESSURE SYSTEM WILL CREST OVER THE REGION TODAY THEN MOVE OFF TO THE EAST THIS EVENING. WEAK LOW PRESSURE WILL DEVELOP OVER THE GULF OF MAINE BEHIND THE DEPARTING LOW AND SPREAD RAIN AND SNOW INTO NEW BRUNSWICK TONIGHT. INTENSE LOW PRESSURE WILL MOVE INTO THE GREAT LAKES TONIGHT THEN MOVE INTO SOUTHEASTERN QUEBEC PROVINCE EARLY SUNDAY. && .SHORT TERM /SUNDAY THROUGH MONDAY/... AN INTERESTING SETUP FOR SUNDAY NIGHT INTO EARLY MONDAY. A FRONTAL SYSTEM IS FORECAST TO SLIDE ACROSS THE AREA ON SUNDAY W/SOME SHOWERS OR LIGHT RAIN PULLING OUT OF THE AREA IN THE MORNING. THE 2ND BATCH OF PRECIP IN THE FORM OF RAIN IS EXPECTED TO SET UP LATER IN DAY AS LOW PRES DEVELOPS OFF THE SOUTHERN NEW ENGLAND COAST AND LIFTS NNE. THE AREAS THAT WILL SEE MEASURABLE QPF WILL BE ACROSS THE EASTERN 1/2 OF THE CWA WHERE THE BEST FORCING AND LLVL CONVERGENCE WILL BE LOCATED. AS THE LOW LIFTS TO NNE AND THE UPPER TROF DIGS SOME AS IT SWINGS INTO THE NE, COLDER AIR WILL START TO FILTER INTO THE REGION. THE ECMWF AND GFS ARE IN AGREEMENT W/THE COLDER AIR COMING IN BY THE EVENING WHILE THE CANADIAN GEM & NAM HOLD THE COLDER AIR BACK BY 3-6 HRS. DECIDED TO GO W/A CONSENSUS BLEND OF THE GUIDANCE FOR THIS PACKAGE SHOWING RAIN GOING OVER TO A PERIOD OF SNOW BY 11 PM OR SO. ALL THE GUIDANCE IS IN AGREEMENT THAT THE BULK OF THE QPF WILL BE ACROSS THE EASTERN 3RD OF THE CWA SAY FROM FROM HOULTON DOWN INTO HANCOCK AND WASHINGTON COUNTY W/UP AROUND 0.50 INCHES. ATTM, IF THERE IS TO BE ANY SNOWFALL ACCUMULATION, IT WILL BE ACROSS EASTERN WASHINGTON COUNTY W/A SLUSHY INCH POSSIBLE BEFORE THINGS WIND DOWN MONDAY MORNING. TEMPERATURES ARE FORECAST TO DROP DOWN INTO THE LOWER 30S ACROSS EASTERN AREAS AFTER MIDNIGHT W/MID AND UPPER 20S BACK ACROSS THE W AND NW AREAS. THE LOW IS FORECAST TO QUICKLY LIFT ACROSS THE MARITIMES ON MONDAY W/CAA POURING INTO THE REGION AND DRIER CONDITIONS. THERE IS SOME CONCERN THE CLOUDS ACROSS NORTHERN AND EASTERN MAINE MIGHT HANG ON THROUGH MONDAY W/A NNW FLOW COMING IN OFF THE OPEN ST. LAWRENCE. THE GFS SOUNDINGS HINT AT THIS TO BE POSSIBLE W/SOME MOISTURE SHOWING UP BELOW 3000 FT. THIS SETUP SIMILAR TO THIS SCENARIO TOOK PLACE LAST WEEK WHEN A CLOUD DECK BELOW 2500 FT HUNG ON LONGER THAN ANTICIPATED. TEMPERATURES ON MONDAY WILL BE HELD DOWN INTO THE 30S W/CLOUDS AND A NNW WIND OF 10 TO 20 MPH. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A NNW WIND AND CLOUDS LOOK TO HANG ON ESPECIALLY FOR NORTHERN AND EASTERN AREAS MONDAY NIGHT W/CAA CONTINUING TO POUR INTO THE REGION. ANOTHER ITEM TO BE AWARE OF WILL BE POTENTIAL FOR STREAMERS OF LIGHT SNOW FROM THE OPEN ST. LAWRENCE FOR PORTIONS OF NORTHERN AND EASTERN MAINE. THE MODEL GUIDANCE TENDS TO HAVE A DIFFICULT TIME IN PICKING UP THIS MESO-SCALE FEATURE. THE HRRR MODEL AND NAM12 TEND TO CATCH ON AS WE CLOSE IN CLOSER TO THE EVENT. CONTINUED BREEZY AND COLD ON TUESDAY W/SOME PARTIAL CLEARING ACROSS NORTHERN MAINE AS HIGH PRES STARTS TO MOVE IN FROM THE W. DOWNEAST AND THE COAST SHOULD SEE A DECENT AMOUNT OF SUNSHINE. DAYTIME TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL FOR LATE NOVEMBER. STRONG HIGH PRES IS FORECAST TO BUILD ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY AND THEN LIFT TO THE NE INTO THE NW ATLC ON THANKSGIVING DAY. THIS WILL MEAN DRY TRAVEL WEATHER FOR THE THANKSGIVING HOLIDAY W/MODERATING TEMPERATURES. && .AVIATION /11Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: EXPECT VFR CONDITIONS TODAY AND TONIGHT. SHORT TERM: IFR/MVFR CONDITIONS FOR SUNDAY W/IFR MAINLY FROM KHUL TO KBHB. MVFR FOR THE REMAINDER OF THE TAF SITES THROUGH SUNDAY EVENING. CONDITIONS EXPECTED TO IMPROVE TO VFR FOR KBGR AND KBHB FRO MONDAY WHILE THE NORTHERN TAF SITES COULD SEE PERIODS OF MVFR CIGS. ATTM, VFR EXPECTED FOR ALL TAF SITES FOR TUESDAY INTO WEDNESDAY && .MARINE... UPDATE 0615 AM: HAVE REMOVE SCA FOR ZONES 51 & 52 AND WILL KEEP SCA FOR ZONE 50 UNTIL 15Z. NEAR TERM: FOR SUSTAINED WINDS HAVE USED THE NAM12. FOR WAVES: BUOY OBSERVATIONS INDICATE LONG PERIOD INCOMING SWELL STILL PRESENT FROM SOUTHEASTERLY FETCH EARLY FRIDAY. EXPECT THIS TO SUBSIDE RAPIDLY EARLY TODAY WITH OFF-SHORE WIND WAVE BECOMING THE PREDOMINATE WAVE SYSTEM. SEAS WILL SUBSIDE RAPIDLY TONIGHT ALONG WITH WINDS WITH LONG PERIOD SOUTHEASTERLY WAVE SYSTEM 1-2 FEET/8 SECONDS ONCE AGAIN BECOMING PREDOMINATE. SHORT TERM: LOOKING FOR THE POTENTIAL FOR SCA CONDITIONS TO DEVELOP SUNDAY NIGHT INTO MONDAY ESPECIALLY FOR THE OUTER ZONES. WINDS ARE EXPECTED TO INCREASE TO 15 TO 20 KT W/GUSTS OF 25 KTS AND A SWELL GENERATION TAKING PLACE ALLOWING FOR SEAS TO BUILD TO 5 TO 7 FT. AS A MATTER OF FACT, SCA CONDITIONS COULD HANG ON RIGHT INTO MONDAY AS THE PRES GRADIENT TIGHTENS BETWEEN THE LOW PASSING ACROSS THE MARITIMES AND STRONG HIGH PRES MOVING IN FROM THE W. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ050. && $$ NEAR TERM...MIGNONE SHORT TERM...HEWITT LONG TERM...HEWITT AVIATION...MIGNONE/HEWITT MARINE...MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
458 AM EST SAT NOV 21 2015 .SYNOPSIS... HIGH PRESSURE WILL CREST OVER THE REGION TODAY. LOW PRESSURE WILL MOVE NORTHWEST OF THE AREA ON SUNDAY WITH SOME RAIN. A SECOND AREA OF LOW PRESSURE WILL LIFT ACROSS THE GULF OF MAINE SUNDAY NIGHT AND THEN INTO THE MARITIMES ON MONDAY WITH MUCH COLDER AIR. && .NEAR TERM /THROUGH TONIGHT/... HIGH PRESSURE WILL BUILD IN FROM THE WEST THIS MORNING WITH CLEARING EARLY TODAY. THE HIGH PRESSURE SYSTEM WILL CREST OVER THE REGION TODAY THEN MOVE OFF TO THE EAST THIS EVENING. WEAK LOW PRESSURE WILL DEVELOP OVER THE GULF OF MAINE BEHIND THE DEPARTING LOW AND SPREAD RAIN AND SNOW INTO NEW BRUNSWICK TONIGHT. INTENSE LOW PRESSURE WILL MOVE INTO THE GREAT LAKES TONIGHT THEN MOVE INTO SOUTHEASTERN QUEBEC PROVINCE EARLY SUNDAY. && .SHORT TERM /SUNDAY THROUGH MONDAY/... AN INTERESTING SETUP FOR SUNDAY NIGHT INTO EARLY MONDAY. A FRONTAL SYSTEM IS FORECAST TO SLIDE ACROSS THE AREA ON SUNDAY W/SOME SHOWERS OR LIGHT RAIN PULLING OUT OF THE AREA IN THE MORNING. THE 2ND BATCH OF PRECIP IN THE FORM OF RAIN IS EXPECTED TO SET UP LATER IN DAY AS LOW PRES DEVELOPS OFF THE SOUTHERN NEW ENGLAND COAST AND LIFTS NNE. THE AREAS THAT WILL SEE MEASURABLE QPF WILL BE ACROSS THE EASTERN 1/2 OF THE CWA WHERE THE BEST FORCING AND LLVL CONVERGENCE WILL BE LOCATED. AS THE LOW LIFTS TO NNE AND THE UPPER TROF DIGS SOME AS IT SWINGS INTO THE NE, COLDER AIR WILL START TO FILTER INTO THE REGION. THE ECMWF AND GFS ARE IN AGREEMENT W/THE COLDER AIR COMING IN BY THE EVENING WHILE THE CANADIAN GEM & NAM HOLD THE COLDER AIR BACK BY 3-6 HRS. DECIDED TO GO W/A CONSENSUS BLEND OF THE GUIDANCE FOR THIS PACKAGE SHOWING RAIN GOING OVER TO A PERIOD OF SNOW BY 11 PM OR SO. ALL THE GUIDANCE IS IN AGREEMENT THAT THE BULK OF THE QPF WILL BE ACROSS THE EASTERN 3RD OF THE CWA SAY FROM FROM HOULTON DOWN INTO HANCOCK AND WASHINGTON COUNTY W/UP AROUND 0.50 INCHES. ATTM, IF THERE IS TO BE ANY SNOWFALL ACCUMULATION, IT WILL BE ACROSS EASTERN WASHINGTON COUNTY W/A SLUSHY INCH POSSIBLE BEFORE THINGS WIND DOWN MONDAY MORNING. TEMPERATURES ARE FORECAST TO DROP DOWN INTO THE LOWER 30S ACROSS EASTERN AREAS AFTER MIDNIGHT W/MID AND UPPER 20S BACK ACROSS THE W AND NW AREAS. THE LOW IS FORECAST TO QUICKLY LIFT ACROSS THE MARITIMES ON MONDAY W/CAA POURING INTO THE REGION AND DRIER CONDITIONS. THERE IS SOME CONCERN THE CLOUDS ACROSS NORTHERN AND EASTERN MAINE MIGHT HANG ON THROUGH MONDAY W/A NNW FLOW COMING IN OFF THE OPEN ST. LAWRENCE. THE GFS SOUNDINGS HINT AT THIS TO BE POSSIBLE W/SOME MOISTURE SHOWING UP BELOW 3000 FT. THIS SETUP SIMILAR TO THIS SCENARIO TOOK PLACE LAST WEEK WHEN A CLOUD DECK BELOW 2500 FT HUNG ON LONGER THAN ANTICIPATED. TEMPERATURES ON MONDAY WILL BE HELD DOWN INTO THE 30S W/CLOUDS AND A NNW WIND OF 10 TO 20 MPH. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A NNW WIND AND CLOUDS LOOK TO HANG ON ESPECIALLY FOR NORTHERN AND EASTERN AREAS MONDAY NIGHT W/CAA CONTINUING TO POUR INTO THE REGION. ANOTHER ITEM TO BE AWARE OF WILL BE POTENTIAL FOR STREAMERS OF LIGHT SNOW FROM THE OPEN ST. LAWRENCE FOR PORTIONS OF NORTHERN AND EASTERN MAINE. THE MODEL GUIDANCE TENDS TO HAVE A DIFFICULT TIME IN PICKING UP THIS MESO-SCALE FEATURE. THE HRRR MODEL AND NAM12 TEND TO CATCH ON AS WE CLOSE IN CLOSER TO THE EVENT. CONTINUED BREEZY AND COLD ON TUESDAY W/SOME PARTIAL CLEARING ACROSS NORTHERN MAINE AS HIGH PRES STARTS TO MOVE IN FROM THE W. DOWNEAST AND THE COAST SHOULD SEE A DECENT AMOUNT OF SUNSHINE. DAYTIME TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL FOR LATE NOVEMBER. STRONG HIGH PRES IS FORECAST TO BUILD ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY AND THEN LIFT TO THE NE INTO THE NW ATLC ON THANKSGIVING DAY. THIS WILL MEAN DRY TRAVEL WEATHER FOR THE THANKSGIVING HOLIDAY W/MODERATING TEMPERATURES. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: EXPECT VFR CONDITIONS TODAY AND TONIGHT. SHORT TERM: IFR/MVFR CONDITIONS FOR SUNDAY W/IFR MAINLY FROM KHUL TO KBHB. MVFR FOR THE REMAINDER OF THE TAF SITES THROUGH SUNDAY EVENING. CONDITIONS EXPECTED TO IMPROVE TO VFR FOR KBGR AND KBHB FRO MONDAY WHILE THE NORTHERN TAF SITES COULD SEE PERIODS OF MVFR CIGS. ATTM, VFR EXPECTED FOR ALL TAF SITES FOR TUESDAY INTO WEDNESDAY && .MARINE... NEAR TERM: FOR SUSTAINED WINDS HAVE USED THE NAM12. FOR WAVES: BUOY OBSERVATIONS INDICATE LONG PERIOD INCOMING SWELL STILL PRESENT FROM SOUTHEASTERLY FETCH EARLY FRIDAY. EXPECT THIS TO SUBSIDE RAPIDLY EARLY TODAY WITH OFF-SHORE WIND WAVE BECOMING THE PREDOMINATE WAVE SYSTEM. SEAS WILL SUBSIDE RAPIDLY TONIGHT ALONG WITH WINDS WITH LONG PERIOD SOUTHEASTERLY WAVE SYSTEM 1-2 FEET/8 SECONDS ONCE AGAIN BECOMING PREDOMINATE. SHORT TERM: LOOKING FOR THE POTENTIAL FOR SCA CONDITIONS TO DEVELOP SUNDAY NIGHT INTO MONDAY ESPECIALLY FOR THE OUTER ZONES. WINDS ARE EXPECTED TO INCREASE TO 15 TO 20 KT W/GUSTS OF 25 KTS AND A SWELL GENERATION TAKING PLACE ALLOWING FOR SEAS TO BUILD TO 5 TO 7 FT. AS A MATTER OF FACT, SCA CONDITIONS COULD HANG ON RIGHT INTO MONDAY AS THE PRES GRADIENT TIGHTENS BETWEEN THE LOW PASSING ACROSS THE MARITIMES AND STRONG HIGH PRES MOVING IN FROM THE W. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ050>052. && $$ NEAR TERM...MIGNONE SHORT TERM...HEWITT LONG TERM...HEWITT AVIATION...MIGNONE/HEWITT MARINE...MIGNONE/HEWITT
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1102 AM EST SAT NOV 21 2015 .SYNOPSIS... A COLD FRONT WILL SPAWN RAIN AND SNOW SHOWERS TONIGHT. SNOW SHOWERS ON SUNDAY WILL AFFECT AREAS NORTH OF INTERSTATE 80. && .NEAR TERM /THROUGH TONIGHT/... PRIMARY ADJUSTMENTS THIS MORNING INCLUDE INCREASE IN SKY COVER TO REFLECT CURRENT MID-LEVEL DECK AND MODEST CHANGES TO MAXIMA GIVEN PERSISTENT CLOUD DECK. SELY WIND IS EXPECTED TO INCREASE DURING THE NEXT HOUR OR TWO...WHICH WILL PROVIDE A DOWNSLOPE COMPONENT AND MAY AID IN INCREASING TEMPS SLIGHTLY VIA COMPRESSIONAL WARMING. PREVIOUS DISCUSSION FOLLOWS... THE PREDAWN UPDATE INCLUDED AN UPWARD BUMP IN TEMPS AND WIND GUSTS BASED ON THE LATEST RAP AND HRR MDL SOUNDINGS WHICH INDICATE LESS CLOUD COVER AND A HIGHER MIXING HEIGHT IN THE WARM ADVECTION REGIME OF TODAY. PRECIP CHANCES WILL BE ON THE INCREASE LATE THIS EVE...CUMULATING IN LIKELY AND CATEGORICAL NUMBERS FOR THE REGION...AS A COLD FRONT SWEEPS OUT OF THE MIDWEST WITH LOW PRESSURE DEEPENING OVR THE GREAT LAKES. WITH THE SFC LOW PROJECTED TO REMAIN WEST OF THE IMMEDIATE AREA...AND WITH DRY ENCROACHMENT AND MID LEVEL TROUGH PROGRESSION...THE PRECIP POTENTIAL IS EXPECTED TO REMAIN WITH THE ACTUAL FRONT. THE TEMPERATURE GRADIENT IS STILL EXPECTED TO SUPPORT A CHANGE FROM RAIN...TO SNOW SHOWERS AFTER FRONTAL PASSAGE...ALTHOUGH THE FADING DYNAMICS PER THE WESTWARD TRACK AND RELATIVELY WARM BOUNDARY LAYER WILL NOT BE SUPPORTIVE OF ANY SIGNIFICANT ACCUMULATION OUTSIDE OF THE I 80 CORRIDOR AND RIDGES WHICH COULD SEE AN INCH IN THE PREDAWN. && .SHORT TERM /SUNDAY THROUGH MONDAY/... ZONES NORTH OF I 80 AS WELL AS THE RIDGES WILL EXPERIENCE SOME LINGERING SNOW SHOWER POTENTIAL INTO SUNDAY. THE BETTER ACCUMULATION POTENTIAL...ALBEIT ON THE ORDER OF AN ANOTHER INCH GIVEN PROJECTIONS OF A FAIRLY DEEP MIXING LAYER WITH THE LAKE TAP...IS LIKELY TO BE CONFINED TO EXTREME NORTHERN PORTIONS OF MERCER AND VENANGO COUNTIES GIVEN THE STRONG WESTERLY WIND COMPONENT OF THE BOUNDARY LAYER FLOW. OTHERWISE...SUNDAY LOOKS TO BE DRY/MAYBE SOME FLURRIES...BUT COLD WITH HIGHS FORECAST APPROXIMATELY 10 DEGREES UNDER THE AVERAGES...WHICH WERE FORECAST USING A GUIDANCE BLEND. THE COLD UPPER TROUGH IS PROJECTED TO PIVOT EASTWARD WHILE A SURFACE HIGH BUILDS OVER THE REGION ON MONDAY. A WEAK SHORTWAVE EMBEDDED IN THE FLOW MAY PROVIDE FOR ADDITIONAL CLOUD COVER...BUT TEMPERATURES SHOULD BEGIN TO SLOWLY MODERATE FOR THE START OF THE WORK-WEEK. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... COLD EARLY WEEK WEATHER WITH THE AFOREMENTIONED PROGRESSIVE UPR TROUGH IS FORECAST TO MODERATE TOWARD SEASONAL READINGS BY MIDWEEK AS HEIGHTS RISE/FLATTEN IN ADVANCE OF ANOTHER WRN CONUS LOW. A GUIDANCE BLEND WAS USED FOR THE LONG TERM FORECAST. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS STILL EXPECTED THROUGH THIS EVENING. LIGHT PRECIPITATION IS EXPECTED OVERNIGHT AT MOST TERMINALS AS A FRONTAL BOUNDARY CROSSES THE REGION...BUT UPPER-LEVEL SUPPORT WILL WANE QUICKLY...SUGGESTING A BRIEF WINDOW FOR PRECIPITATION BEFORE THE SYSTEM DRY SLOT BRINGS AN END TO ANY PRECIPITATION. COLD AIR WILL INVADE LATE TONIGHT...WHICH MAY PROVIDE A VERY BRIEF CHANGE TO LIGHT SNOW AT THE BACK EDGE OF PRECIPITATION. AS COLD AIR DEPTH INCREASES...LAPSE RATES WILL STEEPEN CONSIDERABLY AND WILL SUPPORT LAKE-ENHANCED PRECIPITATION...PRIMARILY AT NORTHERN TERMINALS GIVEN WIND DIRECTION PRIMARILY FROM THE WEST. CONDITIONS DURING THIS TIME LIKELY WILL SUPPORT IFR-MVFR FLIGHT CATEGORIES OR LOWER...ESPECIALLY IN ANY SNOW SHOWERS. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY/... RESTRICTIONS ARE EXPECTED TO CONTINUE THRU SUNDAY NIGHT WITH AN EASTERN CONUS UPPER TROUGH AND COLD WNWLY FLOW. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ UPDATE...KRAMAR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
527 AM EST SAT NOV 21 2015 .SYNOPSIS... A REINFORCING COLD FRONT WILL SPAWN RAIN AND SNOW SHOWERS TONIGHT. SNOW SHOWERS WILL PLAGUE AREAS NORTH OF I 80 ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... THE PREDAWN UPDATE INCLUDED AN UPWARD BUMP IN TEMPS AND WIND GUSTS BASED ON THE LATEST RAP AND HRR MDL SOUNDINGS WHICH INDICATE LESS CLOUD COVER AND A HIGHER MIXING HEIGHT IN THE WARM ADVECTION REGIME OF TODAY. PRECIP CHANCES WILL BE ON THE INCREASE LATE THIS EVE...CUMULATING IN LIKELY AND CATEGORICAL NUMBERS FOR THE REGION...AS A COLD FRONT SWEEPS OUT OF THE MIDWEST WITH LOW PRESSURE DEEPENING OVR THE GREAT LAKES. WITH THE SFC LOW PROJECTED TO REMAIN WEST OF THE IMMEDIATE AREA...AND WITH DRY ENCROACHMENT AND MID LEVEL TROUGH PROGRESSION...THE PRECIP POTENTIAL IS EXPECTED TO REMAIN WITH THE ACTUAL FRONT. THE TEMPERATURE GRADIENT IS STILL EXPECTED TO SUPPORT A CHANGE FROM RAIN...TO SNOW SHOWERS AFTER FRONTAL PASSAGE...ALTHOUGH THE FADING DYNAMICS PER THE WESTWARD TRACK AND RELATIVELY WARM BOUNDARY LAYER WILL NOT BE SUPPORTIVE OF ANY SIGNIFICANT ACCUMULATION OUTSIDE OF THE I 80 CORRIDOR AND RIDGES WHICH COULD SEE AN INCH IN THE PREDAWN. && .SHORT TERM /SUNDAY THROUGH MONDAY/... ZONES NORTH OF I 80 AS WELL AS THE RIDGES WILL EXPERIENCE SOME LINGERING SNOW SHOWER POTENTIAL INTO SUNDAY. THE BETTER ACCUMULATION POTENTIAL...ALBEIT ON THE ORDER OF AN ANOTHER INCH GIVEN PROJECTIONS OF A FAIRLY DEEP MIXING LAYER WITH THE LAKE TAP...IS LIKELY TO BE CONFINED TO EXTREME NORTHERN PORTIONS OF MERCER AND VENANGO COUNTIES GIVEN THE STRONG WESTERLY WIND COMPONENT OF THE BOUNDARY LAYER FLOW. OTHERWISE...SUNDAY LOOKS TO BE DRY/MAYBE SOME FLURRIES...BUT COLD WITH HIGHS FORECAST APPROXIMATELY 10 DEGREES UNDER THE AVERAGES...WHICH WERE FORECAST USING A GUIDANCE BLEND. THE COLD UPPER TROUGH IS PROJECTED TO PIVOT EASTWARD WHILE A SURFACE HIGH BUILDS OVER THE REGION ON MONDAY. A WEAK SHORTWAVE EMBEDDED IN THE FLOW MAY PROVIDE FOR ADDITIONAL CLOUD COVER...BUT TEMPERATURES SHOULD BEGIN TO SLOWLY MODERATE FOR THE START OF THE WORK-WEEK. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... COLD EARLY WEEK WEATHER WITH THE AFOREMENTIONED PROGRESSIVE UPR TROUGH IS FORECAST TO MODERATE TOWARD SEASONAL READINGS BY MIDWEEK AS HEIGHTS RISE/FLATTEN IN ADVANCE OF ANOTHER WRN CONUS LOW. A GUIDANCE BLEND WAS USED FOR THE LONG TERM FORECAST. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS ARE EXPECTED THROUGH MOST OF TODAY. A COLD FRONT IS PROGGED FOR A LATE AFTERNOON/EVENING PASSAGE WITH A FEW SHOWERS AND CONDITIONS DETERIORATION TO MVFR NEAR AND BEHIND THE FRONT....WITH A PERIOD OF GUSTY W WINDS. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY/... RESTRICTIONS ARE EXPECTED TO CONTINUE THRU SUNDAY NIGHT WITH AN EASTERN CONUS UPPER TROUGH AND COLD W-NW FLOW. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 15/22
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1154 AM CST SAT NOV 21 2015 .SHORT TERM: (Through Tonight) Issued at 255 AM CST Sat Nov 21 2015 Ongoing precipitation will continue through early afternoon, eventually tapering off from west to east due to strong subsidence behind a cold front. A few snowflakes could mix in with the rain at times almost anywhere across the CWA, especially just as the rain is ending because that is when the colder air will also be arriving. However, only the far northern CWA appears to stay cold enough for long enough to see any accumulation, and likely only a dusting at best. Strong CAA behind the aforementioned cold front will produce falling temperatures during the day across most of the area. The exception may be across the far eastern CWA where temperatures could remain steady or perhaps rise by a degree or two before the front arrives. Very windy conditions are expected today, especially for the first few hours after fropa. A tight pressure gradient will lead to sustained winds of 15-25 mph, and stronger winds aloft will mix down and produce gusts of 30-40 mph. These values are consistent with upstream METARs early this morning. BUFKIT soundings from the RAP and the NAM do suggest that the wind gusts could even be a bit higher than currently forecast, which would approach criteria for a wind advisory. However, it does not appear that wind gusts of that magnitude will be widespread enough to warrant issuing a wind advisory, therefore no wind headlines are planned attm. The next shift may revisit the need for wind headlines based on observational trends. Winds should diminish quickly this evening. The coldest temperatures of the season so far are expected tonight and early tomorrow morning. Overnight lows will likely drop into the upper teens to lower 20s across the area. Overnight temperatures would be even lower if it weren`t for the expected mid/high clouds ahead of a secondary vort max dropping through the upper trough tonight. These clouds will interfere with radiational cooling processes. Kanofsky .LONG TERM: (Sunday through Friday) Issued at 255 AM CST Sat Nov 21 2015 A surface high pressure center will be located south of the area this weekend, keeping winds from the west or west-southwest until the surface ridge moves farther eastward during the early or middle part of the week. At that point, winds will likely become southerly ahead of a developing low pressure system, bringing warmer air back into the region. Unlike the 00z runs on the last two days, the current ECMWF/GFS/GEM 00z model runs are in remarkably good agreement on large scale atmospheric features through 00z Wed. The primary features of interest are a large, complex low pressure system over NV/UT and broad southwesterly flow aloft over MO/IL. Model solutions quickly diverge thereafter, and confidence in the forecast beyond Tuesday is low. Kanofsky && .AVIATION: (For the 18z TAFs through 18z Sunday Afternoon) Issued at 1150 AM CST Sat Nov 21 2015 Rapidly moving low pressure system has moved to Indiana taking the precipitaton with it. Clouds will quickly scatter and clear this afternoon. Northwest wind will also calm down going light and variable tonight. High pressure moves east of the area Sunday bringig a light south wind. Specifics for KSTL: MVFR clouds looks to scatter and clear around 22z. Clear overnight with wind becoming light and variable after 06z as high pressure moves in. The high quickly moves east Sunday bringing a light south to southwest wind. An upper level distubance will bring in some mid clouds overnight. JPK && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
603 AM CST SAT NOV 21 2015 .SHORT TERM: (Through Tonight) Issued at 255 AM CST Sat Nov 21 2015 Ongoing precipitation will continue through early afternoon, eventually tapering off from west to east due to strong subsidence behind a cold front. A few snowflakes could mix in with the rain at times almost anywhere across the CWA, especially just as the rain is ending because that is when the colder air will also be arriving. However, only the far northern CWA appears to stay cold enough for long enough to see any accumulation, and likely only a dusting at best. Strong CAA behind the aforementioned cold front will produce falling temperatures during the day across most of the area. The exception may be across the far eastern CWA where temperatures could remain steady or perhaps rise by a degree or two before the front arrives. Very windy conditions are expected today, especially for the first few hours after fropa. A tight pressure gradient will lead to sustained winds of 15-25 mph, and stronger winds aloft will mix down and produce gusts of 30-40 mph. These values are consistent with upstream METARs early this morning. BUFKIT soundings from the RAP and the NAM do suggest that the wind gusts could even be a bit higher than currently forecast, which would approach criteria for a wind advisory. However, it does not appear that wind gusts of that magnitude will be widespread enough to warrant issuing a wind advisory, therefore no wind headlines are planned attm. The next shift may revisit the need for wind headlines based on observational trends. Winds should diminish quickly this evening. The coldest temperatures of the season so far are expected tonight and early tomorrow morning. Overnight lows will likely drop into the upper teens to lower 20s across the area. Overnight temperatures would be even lower if it weren`t for the expected mid/high clouds ahead of a secondary vort max dropping through the upper trough tonight. These clouds will interfere with radiational cooling processes. Kanofsky .LONG TERM: (Sunday through Friday) Issued at 255 AM CST Sat Nov 21 2015 A surface high pressure center will be located south of the area this weekend, keeping winds from the west or west-southwest until the surface ridge moves farther eastward during the early or middle part of the week. At that point, winds will likely become southerly ahead of a developing low pressure system, bringing warmer air back into the region. Unlike the 00z runs on the last two days, the current ECMWF/GFS/GEM 00z model runs are in remarkably good agreement on large scale atmospheric features through 00z Wed. The primary features of interest are a large, complex low pressure system over NV/UT and broad southwesterly flow aloft over MO/IL. Model solutions quickly diverge thereafter, and confidence in the forecast beyond Tuesday is low. Kanofsky && .AVIATION: (For the 12z TAFs through 12z Sunday Morning) Issued at 544 AM CST Sat Nov 21 2015 Surface low nearly on top of STL area attm, with strong pressure gradient in the wake of the low center really beginning to ramp up the winds over western sections of the CWA. Rain continues to work east-northeast in a broad swath from sw MO into s IL, with the back edge of the rain shield nearly coincident with low level temps necessary to support snow. Over the next few hours...band of IFR cigs beneath and west of the low should sweep into STL Metro TAFS with rain continuing. Precip here should generallly remain liquid, although a very brief switch to snow may occur by mid morning before the precip comes to an end. Meanwhile, at KUIN and KCOU it appears that low level AMS is just now getting cold enough to support snow, and there could be a brief period of IFR vsbys with this brief shot of snow. Ceilings will lift into the MVFR range by midday, with this cloud deck then clearing from west to east during the afternoon. Northwest winds will be gusting to around 35kts throughout the morning in the wake of the low, with a gradual decrease in speeds expected during the afternoon. Specifics for KSTL: IFR cigs will develop/advect into the area shortly, with the rain possibly changing over to a brief period of snow before ending around mid morning. As surface low pulls away, cigs should increase into the MVFR range from late morning into the afternoon, with this cloud deck clearing by sunset. Winds will increase rapidly over the next few hours, and expect northwest winds to gust to around 35kts from mid morning into early afternoon, with a slow decrease heading into the early evening hours. Truett && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
431 AM CST SAT NOV 21 2015 .SHORT TERM: (Through Tonight) Issued at 255 AM CST Sat Nov 21 2015 Ongoing precipitation will continue through early afternoon, eventually tapering off from west to east due to strong subsidence behind a cold front. A few snowflakes could mix in with the rain at times almost anywhere across the CWA, especially just as the rain is ending because that is when the colder air will also be arriving. However, only the far northern CWA appears to stay cold enough for long enough to see any accumulation, and likely only a dusting at best. Strong CAA behind the aforementioned cold front will produce falling temperatures during the day across most of the area. The exception may be across the far eastern CWA where temperatures could remain steady or perhaps rise by a degree or two before the front arrives. Very windy conditions are expected today, especially for the first few hours after fropa. A tight pressure gradient will lead to sustained winds of 15-25 mph, and stronger winds aloft will mix down and produce gusts of 30-40 mph. These values are consistent with upstream METARs early this morning. BUFKIT soundings from the RAP and the NAM do suggest that the wind gusts could even be a bit higher than currently forecast, which would approach criteria for a wind advisory. However, it does not appear that wind gusts of that magnitude will be widespread enough to warrant issuing a wind advisory, therefore no wind headlines are planned attm. The next shift may revisit the need for wind headlines based on observational trends. Winds should diminish quickly this evening. The coldest temperatures of the season so far are expected tonight and early tomorrow morning. Overnight lows will likely drop into the upper teens to lower 20s across the area. Overnight temperatures would be even lower if it weren`t for the expected mid/high clouds ahead of a secondary vort max dropping through the upper trough tonight. These clouds will interfere with radiational cooling processes. Kanofsky .LONG TERM: (Sunday through Friday) Issued at 255 AM CST Sat Nov 21 2015 A surface high pressure center will be located south of the area this weekend, keeping winds from the west or west-southwest until the surface ridge moves farther eastward during the early or middle part of the week. At that point, winds will likely become southerly ahead of a developing low pressure system, bringing warmer air back into the region. Unlike the 00z runs on the last two days, the current ECMWF/GFS/GEM 00z model runs are in remarkably good agreement on large scale atmospheric features through 00z Wed. The primary features of interest are a large, complex low pressure system over NV/UT and broad southwesterly flow aloft over MO/IL. Model solutions quickly diverge thereafter, and confidence in the forecast beyond Tuesday is low. Kanofsky && .AVIATION: (For the 06z TAFs through 06z Saturday Night) Issued at 1127 PM CST Fri Nov 20 2015 Occasional light rain will affect the terminals overnight tonight. Ceilings should quickly lower later tonight at KCOU and KUIN behind the inverted trough from VFR down to IFR. Still thinking a changeover from rain to snow at KUIN around 1200 UTC and KCOU at 1300 UTC. Northwest winds will be quite gusty during Saturday morning...on the order of 30-35 knots. Ceilings will be slow to improve during the day on Saturday but do look to scatter out by late Saturday afternoon along with winds becoming lighter. A clear sky and light NW winds are expected for Saturday night. Specifics for KSTL: Occassional light rain will affect the terminal overnight tonight. Ceilings should quickly lower toward 1200 UTC from VFR down to IFR behind after surface low passes just to south of KSTL. Northwest winds will be quite gusty as well by late Saturday morning...on the order of 30-35 knots. Cannot rule out some wet snowflakes mixing in with rain or some flurries toward tail end of precipitation...but left mention out for now. Ceilings will be slow to improve during the day on Saturday but do look to scatter out around 2100 UTC Saturday afternoon along with winds becoming lighter. A clear sky and light NW winds are expected for Saturday night. Gosselin && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1120 PM CST FRI NOV 20 2015 .UPDATE... ISSUED AT 826 PM CST FRI NOV 20 2015 FORECAST WAS UPDATED TO CLEAR HEADLINES...AND REMOVE ALL MENTION OF PRECIPITATION TONIGHT EXCEPT FOR WHAT IS STILL MOVING THROUGH THE FAR SOUTHEAST CORNER OF THE FORECAST AREA...BUT EVEN THAT SHOULD BE DONE SOON. ALSO ADJUSTED TEMPERATURES AND WINDS FOR TONIGHT BASED ON LATEST OBSERVATIONS. A FEW FLURRIES MAY STILL BE REPORTED THIS EVENING BUT NO REDUCTIONS TO VISIBILITY EXPECTED. AT 0230Z THERE WAS ANOTHER SMALL BAND OF VERY LIGHT SNOW OVER THE NEBRASKA PANHANDLE WITH CHADRON DOWN TO 1.25 MI AND 1 MILE AT SCOTTS BLUFF. THE 01Z RUNS OF THE THE OPERATIONAL AND EXPERIMENTAL HRRR BRING THIS LIGHT BAND INTO NORTH CENTRAL-SOUTHWEST NEBRASKA BY 09Z. THESE MODELS INDICATE THAT BAND SHOULD DISSIPATE BEFORE MOVING INTO EASTERN NEBRASKA...BUT WE WILL KEEP ON EYE ON THE TRENDS. && .SHORT TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 230 PM CST FRI NOV 20 2015 SNOW CONTINUES TO FALL ACROSS NORTHERN PARTS OF THE AREA EARLY THIS AFTERNOON WITH HIGHEST AMOUNTS REPORTED ALONG THE NORTHERN BORDER WHERE SNOW HAS BEEN PERSISTENT SINCE THIS MORNING. LATEST REGIONAL RADARS SHOW BACK EDGE OF SNOW MOVING QUICKLY EAST INTO NORTHEAST NEBRASKA AT 19Z WITH COLD FRONT PUSHING SOUTH TOWARD SOUTHEAST NEBRASKA. MAIN SNOW BAND HAS BEEN ORIENTED ALONG 600-700MB AXIS OF FRONTOGENETIC FORCING SINCE THIS MORNING WITH A SECONDARY BAND OF PRECIP OVER SOUTHWEST IOWA ALONG THE 800-900MB AXIS. LATEST SHORT RANGE MODELS SHOW THE MID LEVEL FORCING BECOMING LESS FOCUSED ALONG THE NORTHERN BORDER AND DRIFTING TO THE SOUTHEAST THROUGH THE EVENING WHILE LOW LEVEL FORCING DROPS INTO KANSAS AND MISSOURI AS THE COLD AIR MOVES INTO THE AREA. WILL CONTINUE WITH CURRENT HEADLINES FOR NOW SINCE WINDS WILL BE PICKING UP BEHIND THE FRONT. CURRENT SNOW AMOUNTS AND ORIENTATION ALSO LOOKS PRETTY GOOD WITH AMOUNTS DROPPING OFF QUICKLY SOUTH OF THE PLATTE RIVER INTO SOUTHWEST CORNER OF IOWA. SYSTEM SHOULD BE PRETTY MUCH OUT OF THE AREA BY MID TO LATE EVENING. A PERIOD OF DRY WEATHER FOLLOWS BEHIND THIS SYSTEM FOR SATURDAY INTO MONDAY. COLD TEMPERATURES WILL BE THE RULE THROUGH SUNDAY MORNING THEN MODERATING A BIT INTO EARLY NEXT WEEK. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 230 PM CST FRI NOV 20 2015 FIRST PART OF THE WEEK STARTS OFF SEASONAL AND DRY BUT ANOTHER STORM SYSTEM FROM MID TO LATE WEEK WILL BRING THE CHANCE OF MORE WINTER WEATHER TO A LARGE PART OF THE REGION FOR THE THANKSGIVING HOLIDAY. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1120 PM CST FRI NOV 20 2015 WINDS WILL SLOWLY DECREASE OVERNIGHT. CURRENT CIGS FROM 1000 TO 2000 FEET WILL LIFT AND BECOME VFR. STILL SOME POTENTIAL FOR SOME FLURRIES OVERNIGHT BUT GENERALLY SHOULD NOT RESTRICT VSBY BELOW 6 MILES. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ UPDATE...NIETFELD SHORT TERM...FOBERT LONG TERM...FOBERT AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1107 PM CST FRI NOV 20 2015 .UPDATE... ISSUED AT 655 PM CST FRI NOV 20 2015 SENT AN UPDATE OUT FOR THIS EVENING...CURTAILING SNOW EARLIER BY 9 AM FOR ALL AREAS AS THE HRRR SEEMS TO HAVE THE BEST GRIP ON LATEST PRECIPITATION TRENDS AS WELL AS THE RADAR INDICATING THAT MOST PRECIPITATION IS OUT OF OUR CWA. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 319 PM CST FRI NOV 20 2015 THE MAIN CONCERNS IN THE SHORT TERM FORECAST PERIOD ARE ACTUALLY IN THE VERY NEAR TERM AS A LARGE UPPER LEVEL DISTURBANCE IS BRINGING ONGOING PRECIPITATION TO PORTIONS OF NEBRASKA. OTHERWISE THE REMAINDER OF SHORT TERM IS FAIRLY QUIET AND SEASONABLY COLD. FOR THE REST OF TODAY...THE UPPER LEVEL TROUGH WILL CONTINUE TO SURGE EASTWARD ACROSS THE PLAINS...AS A DAUNTING COLD FRONTAL BOUNDARY SINKS QUICKLY SOUTHEAST. LATEST RADAR TRENDS HAS INDICATED POCKETS OF HEAVIER PRECIPITATION REMAINING WELL TO THE NORTH OF INTERSTATE 80 WITH ONLY LIGHT SCATTERED RADAR RETURNS ACROSS THE TRI- CITIES. OBSERVATIONS AROUND MID AFTERNOON SHOW THE FRONTAL BOUNDARY HAS SAGGED AS FAR SOUTH AS THE TRI-CITIES. FORECAST SNOW AMOUNTS COULD BE A BIT HIGH FOR PORTIONS OF POLK COUNTY THIS EVENING. CHANCES FOR PRECIPITATION WILL LAST THE LONGEST FOR THAT COUNTY AS THE SYSTEM EXITS. HOWEVER...TEMPERATURES WILL NEED TO WET BULB DOWN CLOSER TO FREEZING FOR SNOW TO MATERIALIZE. THIS HAPPENED RATHER QUICKLY ACROSS PORTIONS OF VALLEY AND GREELEY COUNTIES BUT CONFIDENCE IS RATHER SHAKY FURTHER SOUTHEAST. THUS SNOW AMOUNTS MAY ACTUALLY BE LOWER THAN FORECAST. THE COLD FRONT WILL CONTINUE TO SURGE SOUTH THIS EVENING WITH STRONG NORTHERLY WINDS BEHIND THE FRONT. THIS INCREASED GUSTS COULD LAST WELL INTO THE OVERNIGHT HOURS BEFORE DECREASING NEAR SUNRISE. THE FRONT WILL USHER IN MUCH COLDER AIR...IN FACT...PROBABLY THE COLDEST OF THE SEASON SO FAR. HIGH TEMPERATURES TOMORROW WILL STRUGGLE TO REACH THE MID TO UPPER 30S. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 319 PM CST FRI NOV 20 2015 A COLD SURFACE HIGH PRESSURE SYSTEM WILL SLIDE TO THE SOUTHEAST SATURDAY NIGHT. TEMPERATURES WILL CONTINUE TO BE COLD SATURDAY NIGHT. BY SUNDAY MORNING THE WINDS ARE TURNING TO THE WEST AND WITH WARM ADVECTION AND DOWN SLOPE WINDS...TEMPERATURES SHOULD RECOVER PRETTY EASILY INTO THE MID 40S TO AROUND 50. WILL HAVE TO WATCH TO SEE HOW MUCH SNOW FALLS THIS AFTERNOON AND IF IT WILL HAVE ANY EFFECT ON THE TEMPERATURES ON SUNDAY. SUNDAY NIGHT THROUGH TUESDAY A WEAK UPPER LEVEL RIDGE MOVES OVER THE AREA. THE SURFACE HIGH MOVES TO THE EAST AND A SURFACE LOW DEVELOPS ON THE HIGH PLAINS. WITH WARM ADVECTION AND WINDS TURNING FROM WEST TO SOUTH...WILL CONTINUE WITH THE WARM TEMPERATURES. READINGS IN THE 50S ARE POSSIBLE DURING THE DAY. AN UPPER LEVEL WAVE STARTS TO APPROACH THE FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY. WITH THE SOUTH WINDS ACROSS THE AREA MONDAY AND TUESDAY THERE IS SOME MOISTURE THAT MOVES NORTH INTO THE AREA...MOSTLY IN THE EAST. BY WEDNESDAY THE UPPER WAVE IS AFFECTING THE AREA ENOUGH THAT WITH THE MOISTURE...THERE IS A SMALL CHANCE FOR SOME LIGHT RAIN...MAINLY NORTH AND EAST IN THE AREA. A COLD FRONT MOVES INTO THE AREA WEDNESDAY AFTERNOON AND EVENING. THE COLD AIR IS A LITTLE BEHIND THE FRONT AND DURING THE AFTERNOON EXPECT RAIN. THE UPPER LEVEL WAVE MOVES INTO THE AREA WEDNESDAY NIGHT AND THE COLD FRONT MOVES TO THE SOUTH. BY WEDNESDAY NIGHT THE TEMPERATURES START TO COOL OFF ENOUGH THAT THE PRECIPITATION SHOULD MIX WITH SNOW FOR MUCH OF THE AREA THEN CHANGE TO SNOW IN THE NORTHWEST. THE NORTHWEST SHOULD BE COLD ENOUGH DURING THE DAY THURSDAY TO KEEP SNOW...BUT PORTIONS OF THE AREA COULD HAVE A MIX WITH MOSTLY RAIN IN THE SOUTHEAST. COLDER AIR CONTINUES TO PUSH INTO THE AREA AND HAVE A CHANCE FOR SNOW BOTH THURSDAY NIGHT AND FRIDAY. THAT IS THE CURRENT THINKING. THE ONE MAIN WRENCH IN ALL OF THIS IS THERE IS A TIGHT TEMPERATURE GRADIENT AT 850MB AS IT MOVES THROUGH THE AREA. THE CHANGE FROM RAIN TO SNOW COULD CHANGE QUITE A BIT AS THE COLD AIR COMES IN. ALSO...IF THE TIMING IS OFF A LITTLE BIT IT COULD MAKE PHASE CHANGE TIMING DIFFERENT AS WELL. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1055 PM CST FRI NOV 20 2015 NORTH WINDS WILL BE GUSTY FOR THE MAJORITY OF THE NIGHT BEFORE SUBSIDING TOWARDS DAYBREAK ON SATURDAY AS THE SFC GRADIENT RELAXES AS HIGH PRESSURE SETTLES ONTO THE PLAINS. CANNOT COMPLETELY RULE OUT A FLURRY POTENTIAL BRIEFLY TONIGHT BUT CHCS ARE FAIRLY MINIMAL. MVFR CIGS WILL INCREASE TO VFR SATURDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...HEINLEIN SHORT TERM...SALTZMAN LONG TERM...JCB AVIATION...FAY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1249 PM EST SAT NOV 21 2015 .SYNOPSIS... LOW PRESSURE WILL LIFT NORTHEAST ACROSS THE GREAT LAKES TODAY WITH A TRAILING COLD FRONT SWEEPING EAST ACROSS THE REGION THIS AFTERNOON. RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS OR FLURRIES BEFORE ENDING TONIGHT. MUCH COLDER AIR WILL SETTLE IN BEHIND THE FRONT FOR THE END OF THE WEEKEND. A WARMING TREND WILL THEN RETURN BY THE FIRST OF THE WEEK INTO THE THANKSGIVING HOLIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ONLY MINOR CHANGES TO GRIDS THIS MORNING AS SURFACE LOW STILL REMAINS ON TRACK TO BE AROUND KDAY AT 18Z. CURRENT SURFACE ANALYSIS FROM THIS MORNING SHOWS THE SURFACE LOW CURRENTLY IN SOUTHERN ILLINOIS WITH A COLD FRONT TRAILING OFF TO THE SOUTHEAST. THERE WAS ALSO A WEAK WARM FRONT ACROSS NORTHERN KENTUCKY. DEWPOINTS NORTH OF THE COLD FRONT WERE MAINLY AROUND 20 DEGREES WHILE SOUTH OF THE WARM FRONT AT OR ABOVE 30 DEGREES. KILN 12Z SOUNDING ALSO SHOWS A GOOD DEAL OF DRY AIR BETWEEN 700 AND 1000 MB. FORECAST SOUNDINGS SHOW THE LAYER SLOWLY SATURATING WITH WEAK WET BULBING FIGHTING WAA AS THE WARM FRONT PUSHES NORTH. LOOKING AT RAP CRITICAL THICKNESSES IT SEEMS LIKE MOST OF THE AREA WILL INITIALLY BE RAIN EXCEPT FOR THE POSSIBILITY OF OUR FAR NORTHERN COUNTIES (DEPENDING ON THE EXACT TRACK OF THE SURFACE LOW AND WARM FRONT). AS THE FRONT PASSES THERE WILL BE A BRIEF PERIOD OF RAIN CHANGING OVER TO A RAIN/SNOW MIX AND THEN SNOW. DRIER MID LEVEL AIR WILL THEN QUICKLY MOVE IN BEHIND THE FRONT. FORECAST SOUNDINGS STILL SHOW LOW LEVEL SATURATION WHICH WOULD SUPPORT FLURRIES BEHIND THE FRONT. WIND GUSTS UP TO 35 MPH CAN ALSO BE EXPECTED ALONG AND BEHIND THE FRONT. PREV DISCUSSION -> MID LEVEL ENERGY DROPPING SE INTO THE PLAINS WILL ACT TO SHARPEN UP AND CARVE OUT A TROF OVER THE NATIONS MID SECTION. AN EMBEDDED S/W TO ROTATE AROUND THE EAST SIDE OF THIS LONG WAVE TROF THRU THE MID MS VLY THIS MORNING AND INTO THE GREAT LAKES BY EVENING. ASSOCIATED SFC LOW OVER THE MID MS VLY TO EJECT NE INTO SW OHIO BY 18Z AND THEN INTO THE EASTERN GREAT LAKES BY EVENING. NUMERICAL MODEL SOLNS HAVE CLUSTERED COMING INTO BETTER AGREEMENT WITH SFC LOW NEAR JUST WEST OF DAYTON AT 18Z. COMPARED TO THE 12Z RUNS...THESE SOLNS HAVE GENERALLY TRENDED FURTHER SOUTH CLOSER TO THE CONSISTENT ECMWF...ALLOWING FOR A QUICKER CHANGE OVER AND A LTL MORE SNOW. WILL ALLOW PCPN TO DEVELOP BY AFTN ACROSS THE WESTERN COUNTIES AND SPREAD EAST. STRONG CAA DEVELOPS WITH 8H TEMPS GOING FROM AT OR ABOVE 5 DEG C TO -6 DEG C IN THE WEST BY 00Z. WILL BUMP UP SNOW TO AROUND 1 INCH ACROSS THE FAR NW TO ABOUT ONE TENTH OF AN INCH ON GRASSY AREAS AT ILN. WILL SHOW NON- DIURNAL TEMPERATURE TREND WITH READINGS FALLING INTO THE 30S IN THE WEST LATE IN THE DAY. EXPECT WEST WIND GUSTS UP TO 35 MPH WITH THE FRONTAL PASSAGE. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... STRONG SFC COLD FRONT EXPECTED TO PUSH THRU ILN/S EASTERN COUNTIES DURG THE EARLY EVENING. STRONG CAA TO DEVELOP WITH 8H TEMPS TO BETWEEN -8 AND -11 DEG C BY SUNDAY MORNING. EXPECT PCPN TO MIX WITH AND CHANGE TO SNOW ACRS THE ENTIRE FA EARLY TONIGHT. BASED ON BETTER AGREEMENT OF SOLNS MORE IN LINE WITH COLDER FURTHER SOUTH ECMWF SOLN...HAVE INCREASED SNOW TO AROUND 1 INCH ACRS THE FAR NW TO A TENTH OF AN INCH AT ILN. FURTHER SOUTH...EXPECT LITTLE OR NO ACCUMULATION. EXPECT PCPN TO END OR DIMINISH TO FLURRIES BY LATE EVENING. AS SFC LOW LIFTS NE INTO SE CANADA...EXPECT DRY SLOW TO PUSH INTO SW OHIO. WILL ALLOW CLOUDS TO DECREASE ACRS THE WEST LATE. THE COLDEST AIR OF THE SEASON WILL SETTLE INTO THE OHIO VALLEY AS SFC HIGH PRESSURE BUILD INTO THE OHIO VALLEY SUNDAY. EXPECT SAT NIGHTS LOWS TO RANGE FROM THE UPPER TEENS FAR NW TO THE UPPER 20S SE. SUNDAY WILL OFFER COLD TEMPERATURES WITH A GOOD AMOUNT OF SUNSHINE. EXPECT SUNDAYS HIGHS TO RANGE FROM THE UPPER 20S NW TO THE MID/UPR 30S SE. TEMPERATURES WILL MODERATE ON THE BACK SIDE OF THE HIGH MONDAY WITH READINGS FROM NEAR 40 NW TO THE MID 40S SE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... UPPER LEVEL TROUGH WILL CROSS THE NORTHERN OHIO VALLEY EARLY MONDAY AND INCREASE CLOUD COVER HERE WITH GENERALLY SUNNY SKIES TO THE SOUTH. THE AXIS OF THE SURFACE HIGH WILL PASS EAST OF THE REGION OVERNIGHT MONDAY AND RETURN FLOW WILL PERMIT A WARMING TREND FOR NEXT WEEK. MODELS DIVERGE SIGNIFICANTLY ON THURSDAY NIGHT AS A LONGWAVE TROUGH RUNS FROM JAMES BAY CANADA TO CALIFORNIA AND A SURFACE FRONT LAYS OUT FROM TX TO SOUTH OF HUDSON BAY. GFS IS PROGRESSIVE WITH THE UPPER LOW AND PULLS THE SURFACE LOW INTO CANADA...SWEEPING THE FRONT THROUGH THE OHIO VALLEY LATER FRIDAY AND OVERNIGHT. THE EUROPEAN DISJOINTS THE UPPER SYSTEM AND CUTS OFF A H5 CLOSED LOW IN THE GREAT BASIN WITH A SOMEWHAT PROGRESSIVE NORTHERN S/W PEELING OFF OF THIS AND CROSSING THE GREAT LAKES OVERNIGHT FRIDAY. THIS KEEPS THE SURFACE FRONT OVER THE MIDWEST AND PULLS ENERGY NORTHEAST AND AWAY FROM THE OHIO VALLEY FOR FRIDAY AND OVERNIGHT. BLENDED THE TWO BUT KEPT FORECAST AREA IN LOW CHANCE POPS ON FRIDAY...INCREASING THEM BEYOND VALID FORECAST PERIOD. FORECAST UNCERTAINTY ON FRIDAY IS HIGH AFTER THURSDAY NIGHT DUE TO THESE DIFFERENCES IN MODELS. TEMPS AT THE END OF THE WEEK SHOULD RISE INTO AT LEAST THE 50S AND COULD PULL INTO THE 60S IF THE DRIER EUROPEAN VERIFIES. CLOUDY AND RAINY GFS VERIFICATION WILL LIMIT HIGHS THIS DAY. TOOK A MIDDLE OF THE ROAD APPROACH BEING THIS FAR OUT. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... SURFACE LOW PRESSURE CURRENTLY LOCATED JUST EAST OF KIND AT THIS HOUR WITH SNOW BEING REPORTED NEAR THE LOW WITH MOSTLY RAIN BEING REPORTED SOUTH OF THE LOW. THE LOW WILL CONTINUE TO TRACK OFF TO THE ENE AND BE APPROACHING DAYTON IN THE NEXT COUPLE OF HOURS. AS PRECIP MOVES INTO THE AREA WIDESPREAD MVFR CIGS CAN BE EXPECTED WITH POCKETS OF IFR IN THE HEAVIER SHOWERS. A SURFACE COLD FRONT WILL THEN PUSH THROUGH THE AREA BRINGING GUSTY WINDS ACROSS THE TAF SITES. 850 MB WINDS ARE SHOWING AROUND 35 KTS (VIA GFS/ RAP) AND WITH STRONG COLD AIR ADVECTION SOME OF THIS SHOULD BE ABLE TO MIX DOWN. THERE WILL ALSO BE A SLIGHT WINDOW OF WHEN RAIN WILL START TO MIX WITH SNOW. IN GENERAL AM NOT IMPRESSED WITH THE CHANCES OF THIS THOUGH (ESP SOUTHERN TAF SITES) AS FORECAST SOUNDINGS QUICKLY DRY OUT THE MID LEVELS. A LACK OF MOISTURE IN THE SNOW GROWTH REGION WOULD FAVOR FLURRIES. TOMORROW AFTERNOON SURFACE HIGH PRESSURE WILL MOVE INTO THE AREA ALLOWING THE AREA TO SLOWLY CLEAR AND WINDS TO RELAX. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HAINES/AR NEAR TERM...HAINES/AR SHORT TERM...AR LONG TERM...FRANKS AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
959 AM EST SAT NOV 21 2015 .SYNOPSIS... LOW PRESSURE WILL LIFT NORTHEAST ACROSS THE GREAT LAKES TODAY WITH A TRAILING COLD FRONT SWEEPING EAST ACROSS THE REGION THIS AFTERNOON. RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS OR FLURRIES BEFORE ENDING TONIGHT. MUCH COLDER AIR WILL SETTLE IN BEHIND THE FRONT FOR THE END OF THE WEEKEND. A WARMING TREND WILL THEN RETURN BY THE FIRST OF THE WEEK INTO THE THANKSGIVING HOLIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ONLY MINOR CHANGES TO GRIDS THIS MORNING AS SURFACE LOW STILL REMAINS ON TRACK TO BE AROUND KDAY AT 18Z. CURRENT SURFACE ANALYSIS FROM THIS MORNING SHOWS THE SURFACE LOW CURRENTLY IN SOUTHERN ILLINOIS WITH A COLD FRONT TRAILING OFF TO THE SOUTHEAST. THERE WAS ALSO A WEAK WARM FRONT ACROSS NORTHERN KENTUCKY. DEWPOINTS NORTH OF THE COLD FRONT WERE MAINLY AROUND 20 DEGREES WHILE SOUTH OF THE WARM FRONT AT OR ABOVE 30 DEGREES. KILN 12Z SOUNDING ALSO SHOWS A GOOD DEAL OF DRY AIR BETWEEN 700 AND 1000 MB. FORECAST SOUNDINGS SHOW THE LAYER SLOWLY SATURATING WITH WEAK WET BULBING FIGHTING WAA AS THE WARM FRONT PUSHES NORTH. LOOKING AT RAP CRITICAL THICKNESSES IT SEEMS LIKE MOST OF THE AREA WILL INITIALLY BE RAIN EXCEPT FOR THE POSSIBILITY OF OUR FAR NORTHERN COUNTIES (DEPENDING ON THE EXACT TRACK OF THE SURFACE LOW AND WARM FRONT). AS THE FRONT PASSES THERE WILL BE A BRIEF PERIOD OF RAIN CHANGING OVER TO A RAIN/SNOW MIX AND THEN SNOW. DRIER MID LEVEL AIR WILL THEN QUICKLY MOVE IN BEHIND THE FRONT. FORECAST SOUNDINGS STILL SHOW LOW LEVEL SATURATION WHICH WOULD SUPPORT FLURRIES BEHIND THE FRONT. WIND GUSTS UP TO 35 MPH CAN ALSO BE EXPECTED ALONG AND BEHIND THE FRONT. PREV DISCUSSION -> MID LEVEL ENERGY DROPPING SE INTO THE PLAINS WILL ACT TO SHARPEN UP AND CARVE OUT A TROF OVER THE NATIONS MID SECTION. AN EMBEDDED S/W TO ROTATE AROUND THE EAST SIDE OF THIS LONG WAVE TROF THRU THE MID MS VLY THIS MORNING AND INTO THE GREAT LAKES BY EVENING. ASSOCIATED SFC LOW OVER THE MID MS VLY TO EJECT NE INTO SW OHIO BY 18Z AND THEN INTO THE EASTERN GREAT LAKES BY EVENING. NUMERICAL MODEL SOLNS HAVE CLUSTERED COMING INTO BETTER AGREEMENT WITH SFC LOW NEAR JUST WEST OF DAYTON AT 18Z. COMPARED TO THE 12Z RUNS...THESE SOLNS HAVE GENERALLY TRENDED FURTHER SOUTH CLOSER TO THE CONSISTENT ECMWF...ALLOWING FOR A QUICKER CHANGE OVER AND A LTL MORE SNOW. WILL ALLOW PCPN TO DEVELOP BY AFTN ACROSS THE WESTERN COUNTIES AND SPREAD EAST. STRONG CAA DEVELOPS WITH 8H TEMPS GOING FROM AT OR ABOVE 5 DEG C TO -6 DEG C IN THE WEST BY 00Z. WILL BUMP UP SNOW TO AROUND 1 INCH ACROSS THE FAR NW TO ABOUT ONE TENTH OF AN INCH ON GRASSY AREAS AT ILN. WILL SHOW NON- DIURNAL TEMPERATURE TREND WITH READINGS FALLING INTO THE 30S IN THE WEST LATE IN THE DAY. EXPECT WEST WIND GUSTS UP TO 35 MPH WITH THE FRONTAL PASSAGE. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... STRONG SFC COLD FRONT EXPECTED TO PUSH THRU ILN/S EASTERN COUNTIES DURG THE EARLY EVENING. STRONG CAA TO DEVELOP WITH 8H TEMPS TO BETWEEN -8 AND -11 DEG C BY SUNDAY MORNING. EXPECT PCPN TO MIX WITH AND CHANGE TO SNOW ACRS THE ENTIRE FA EARLY TONIGHT. BASED ON BETTER AGREEMENT OF SOLNS MORE IN LINE WITH COLDER FURTHER SOUTH ECMWF SOLN...HAVE INCREASED SNOW TO AROUND 1 INCH ACRS THE FAR NW TO A TENTH OF AN INCH AT ILN. FURTHER SOUTH...EXPECT LITTLE OR NO ACCUMULATION. EXPECT PCPN TO END OR DIMINISH TO FLURRIES BY LATE EVENING. AS SFC LOW LIFTS NE INTO SE CANADA...EXPECT DRY SLOW TO PUSH INTO SW OHIO. WILL ALLOW CLOUDS TO DECREASE ACRS THE WEST LATE. THE COLDEST AIR OF THE SEASON WILL SETTLE INTO THE OHIO VALLEY AS SFC HIGH PRESSURE BUILD INTO THE OHIO VALLEY SUNDAY. EXPECT SAT NIGHTS LOWS TO RANGE FROM THE UPPER TEENS FAR NW TO THE UPPER 20S SE. SUNDAY WILL OFFER COLD TEMPERATURES WITH A GOOD AMOUNT OF SUNSHINE. EXPECT SUNDAYS HIGHS TO RANGE FROM THE UPPER 20S NW TO THE MID/UPR 30S SE. TEMPERATURES WILL MODERATE ON THE BACK SIDE OF THE HIGH MONDAY WITH READINGS FROM NEAR 40 NW TO THE MID 40S SE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL TROUGH WILL CROSS THE NORTHERN OHIO VALLEY EARLY MONDAY AND INCREASE CLOUD COVER HERE WITH GENERALLY SUNNY SKIES TO THE SOUTH. THE AXIS OF THE SURFACE HIGH WILL PASS EAST OF THE REGION OVERNIGHT MONDAY AND RETURN FLOW WILL PERMIT A WARMING TREND FOR NEXT WEEK. MODELS DIVERGE SIGNIFICANTLY ON THURSDAY NIGHT AS A LONGWAVE TROUGH RUNS FROM JAMES BAY CANADA TO CALIFORNIA AND A SURFACE FRONT LAYS OUT FROM TX TO SOUTH OF HUDSON BAY. GFS IS PROGRESSIVE WITH THE UPPER LOW AND PULLS THE SURFACE LOW INTO CANADA...SWEEPING THE FRONT THROUGH THE OHIO VALLEY LATER FRIDAY AND OVERNIGHT. THE EUROPEAN DISJOINTS THE UPPER SYSTEM AND CUTS OFF A H5 CLOSED LOW IN THE GREAT BASIN WITH A SOMEWHAT PROGRESSIVE NORTHERN S/W PEELING OFF OF THIS AND CROSSING THE GREAT LAKES OVERNIGHT FRIDAY. THIS KEEPS THE SURFACE FRONT OVER THE MIDWEST AND PULLS ENERGY NORTHEAST AND AWAY FROM THE OHIO VALLEY FOR FRIDAY AND OVERNIGHT. BLENDED THE TWO BUT KEPT FORECAST AREA IN LOW CHANCE POPS ON FRIDAY...INCREASING THEM BEYOND VALID FORECAST PERIOD. FORECAST UNCERTAINTY ON FRIDAY IS HIGH AFTER THURSDAY NIGHT DUE TO THESE DIFFERENCES IN MODELS. TEMPS AT THE END OF THE WEEK SHOULD RISE INTO AT LEAST THE 50S AND COULD PULL INTO THE 60S IF THE DRIER EUROPEAN VERIFIES. CLOUDY AND RAINY GFS VERIFICATION WILL LIMIT HIGHS THIS DAY. TOOK A MIDDLE OF THE ROAD APPROACH BEING THIS FAR OUT. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... TAF SITES WILL STAY UNDER VFR THROUGH THE EARLY PART OF THE FORECAST AS HIGH PRESSURE MOVES EAST. CONDITIONS WILL DETERIORATE AFTER 18Z WHEN RAIN SHOWERS WITH MVFR WILL MOVE IN AHEAD OF A STRONG COLD FRONT. SNOW SHOWERS WITH MVFR ARE LIKELY STARTING AT 22Z WHEN COLDER AIR ARRIVES WITH FRONTAL PASSAGE AND A WIND SHIFT TO WEST. GUSTS OVER 30 KNOTS WILL BE POSSIBLE ALONG AND BEHIND THE FRONT ESPECIALLY AT DAY. SNOW SHOWERS WILL END AND WINDS WILL SLOWLY SUBSIDE AFTER 02Z SUNDAY. CVG WILL SEE SCT CLOUDS AND DECREASING NORTHWEST WINDS AFTER 12Z SUNDAY. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HAINES/AR NEAR TERM...HAINES/AR SHORT TERM...AR LONG TERM...FRANKS AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
953 AM EST SAT NOV 21 2015 .SYNOPSIS... A COLD FRONT CROSSES TONIGHT...MAKING THE SECOND HALF OF THE WEEKEND MUCH COLDER THAN THE FIRST...WITH MAINLY MOUNTAIN SNOW SHOWERS. HIGH PRESSURE NEXT WEEK WITH MODERATING TEMPERATURES. && .NEAR TERM /THROUGH TONIGHT/... 945 AM UPDATE... RAISED TEMPS A FEW DEGREES THIS AFTN OVER THE LOWLANDS. WINDS WILL PICK UP AHEAD OF THE FRONT AND ESPECIALLY JUST BEHIND THE FRONT WHERE BUFKIT AND HRRR SUGGESTS 30 TO 35 KT GUSTS THIS EVENING. AS FOR FIRE CONCERNS...THERE MAY BE ENOUGH OF A REBOUND IN RH THIS AFTERNOON AS THE WINDS PICK UP TO MITIGATE NEEDING A FIRE SPS. WILL CONTINUE TO MONITOR TRENDS OVER THE NEXT FEW HRS. PREV DISCN... LOW PRESSURE CENTER APPROACHES FROM THE LOWER OHIO VALLEY TODAY. IT TAKES A LEFT HAND TURN THIS AFTERNOON...REACHING THE UPPER OHIO VALLEY THIS EVENING...AS ITS ASSOCIATED UPPER LEVEL S/W TROUGH ROUNDS THE BASE OF THE L/W TROUGH AND STARTS COMING UP THE E SIDE...TAKING ON A NEGATIVE TILT AS A RESULT. THE SYSTEM IS PROGGED TO DEEPEN TO THE TUNE OF ABOUT 6 MB / HR THIS AFTERNOON AND TONIGHT...CROSSING SERN ONTARIO AND MOVING INTO SWRN QUEBEC TONIGHT. THE WARM FRONT AHEAD OF THE APPROACHING LOW LIFTS NWD THROUGH THE AREA THIS MORNING AND MIDDAY...THE ASSOCIATED MID AND HIGH CLOUD RETREATING NWD WELL AHEAD OF THE SFC FRONT FIRST THING THIS MORNING. THIS PLACES THE FCST AREA IN THE WARM SECTOR THIS AFTERNOON. EXITING DRY AIR WILL RESULT IN RH VALUES DIPPING INTO THE 20S THIS AFTERNOON ACROSS CENTRAL AND NRN WV. WITH GUSTY WARM SECTOR WINDS THIS AFTERNOON...AND DRYING FUELS...A FIRE DANGER STATEMENT MAY BE NEEDED...AND THE LOW PROB HWO MENTION WILL CONTINUE FOR THIS. SHOWERS ARRIVE JUST AHEAD OF THE COLD FRONT THIS EVENING. COLDER AIR RUSHES IN BEHIND THE SYSTEM WITH SHARP PRESSURE RISES BEHIND THE COLD FRONT...ENDING THE PRECIPITATION AS IT ARRIVES. THEREFORE SEE A VERY NARROW WINDOW OF OPPORTUNITY FOR A FEW SNOW FLAKES OVER THE LOWLANDS AS THE SHOWERS END...MORE SO N THAN S IF ANYTHING. THERE IS...OF COURSE...A BETTER CHANCE FOR SNOW IN THE MOUNTAINS TONIGHT...ESPECIALLY ACROSS THE HIGHER TERRAIN...AS UPSLOPE ENHANCES LOW LEVEL LIFT DURING THE COLD ADVECTION. AMOUNTS WILL BE LIMITED BY LACK OF DENDRITIC GROWTH...AS IT WILL TAKE THE UPSLOPE FLOW OVER THE MOUNTAINS JUST TO GET THE TOP OF THE SATURATED UP INTO THE -8C AND COLDER LAYER. THOUGHT OVERNIGHT POPS MAY HAVE BEEN A BIT HIGH FOR THIS REASON BUT OPTED TO LEAVE AS IS. HAVE CUT BACK ON SNOW AMOUNTS TO UNDER AN INCH EVEN ACROSS THE HIGHEST RIDGES...MAYBE A TRACE ON NRN LOWLAND HILLTOPS. USED A MET/MAV/PREV BLEND FOR HIGHS IN THE WARM SECTOR TODAY...AND A NAM/MET/PREV BLEND FOR HOURLY TEMPERATURES TONIGHT AS THE BAROCLINIC ZONE MOVES THROUGH...A LITTLE SLOWER ON THE COOLING THAN PREVIOUS. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... FRONT WILL BE THROUGH CWA WITH COLD AIR ADVECTION TAKING PLACE DURING THE DAY ON SUNDAY AND CONTINUING SUNDAY NIGHT. SURFACE HIGH PRESSURE BEGINS BUILDING IN FROM THE WEST. 5H TROUGH...WITH 85H THERMAL TROUGH FOLLOWING...WILL MOVE THROUGH DURING THE DAY SUNDAY. LOW LEVELS DRY OUT FAIRLY QUICKLY...HOWEVER RESIDUAL MOISTURE WITH SOME ENHANCED DYNAMICS WILL HANG ON TO ALLOW FOR THE CONTINUATION OF A FEW SNOW SHOWERS...PERHAPS ENDING BY SUNDAY AFTERNOON. ATMOSPHERIC COLUMN WILL CONTINUE DRYING TREND FOR THE REST OF THE PERIOD WITH NORTHWEST FLOW USHERING COOLER AIR. WILL SEE SOME OF THE COLDEST TEMPERATURES MONDAY MORNING. FOR TEMPS...USED MODEL BLEND ACROSS THE BOARD...AVERAGING VALUES BACK INTO INHERITED FORECAST. && .LONG TERM /TUESDAY THROUGH FRIDAY/... MODELS AND ENSEMBLES SHOWING HIGH PRESSURE OVER THE AREA FOR MONDAY NIGHT THROUGH THURSDAY NIGHT. NEXT SYSTEM ARRIVES LATE IN THE WEEK OR NEXT WEEKEND. CONFIDENCE IN TIMING OF THIS COLD FRONT IS LOW. USED A BLEND OF THE GEFS AND ECMWF ENSEMBLE MEANS. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... VFR THROUGH TODAY YIELDS TO MVFR CONDITIONS FROM W TO E TONIGHT...AS A LOW PRESSURE SYSTEM APPROACHES FROM THE LOWER OHIO VALLEY. ITS WARM FRONT WILL MOVE NWD THROUGH THE AREA DURING THE MORNING AND MIDDAY HOURS TODAY. THE LOW ITSELF WILL TAKE A LEFT HAND TURN THIS AFTERNOON AND REACH THE UPPER OHIO VALLEY BY THIS EVENING. THIS WILL BRING ITS COLD FRONT TO THE OHIO RIVER NEAR 00Z SUN AND THEN THROUGH THE MOUNTAINS BY 06Z SUN. SHOWERS WILL ARRIVE JUST AHEAD OF...IF NOT WITH...THE COLD FRONT...THIS EVENING...LIKELY BRINGING VSBYS DOWN TO MVFR AND THEN CIGS DOWN TO MVFR AN HOUR OR TWO AFTER THE COLD FRONT PASSES. THE RAIN SHOWERS WILL SWITCH OVER TO SNOW SHOWERS OVER THE MOUNTAINS OVERNIGHT TONIGHT. VSBYS WILL IMPROVE TO VFR FROM W TO E OVERNIGHT AS THE PRECIPITATION ENDS. LIGHT E TO SE FLOW AHEAD OF THE WARM FRONT THIS MORNING WILL BECOME S TO SW AND GUSTY IN THE WARM SECTOR AHEAD OF THE COLD FRONT THIS AFTERNOON AND EVENING...AND THEN W TO SW AND STILL A BIT GUSTY BEHIND THE COLD FRONT TONIGHT...THEN W TO NW AND DIMINISHING A BIT TOWARD DAWN SUN. LIGHT SW FLOW ALOFT THIS MORNING WILL BECOME MODERATE SW THIS AFTERNOON...SHIFTING TO MODERATE W BEHIND THE COLD FRONT TONIGHT...AND THEN LIGHT TO MODERATE NW BY DAWN SUN. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY... FORECAST CONFIDENCE: HIGH. ALTERNATE SCENARIOS: ONSET AND EXTENT OF MVFR IN RAIN SHOWERS AND CIGS MAY VARY LATE TODAY AND TONIGHT. GUSTY WINDS WILL VARY LATER TODAY AND TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02 EST 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H H H H H H H H H H H M HTS CONSISTENCY H H H H H H H H H M M H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H M M M CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z SUNDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KMC/TRM NEAR TERM...TRM/30 SHORT TERM...KMC LONG TERM...RPY AVIATION...TRM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
518 PM EST SAT NOV 21 2015 .SYNOPSIS... A FAST MOVING AREA OF LOW PRESSURE WILL RACE DOWN THE ST LAWRENCE RIVER VALLEY TONIGHT AND SUNDAY...PUSHING A COLD FRONT ACROSS THE REGION OVERNIGHT. A WEAK CLIPPER LOW WILL MOVE THROUGH NEW YORK STATE MONDAY NIGHT...FOLLOWED BY A RIDGE OF HIGH PRESSURE THAT WILL BUILD OVER THE OHIO VALLEY AND EASTERN US TUESDAY THROUGH THANKSGIVING DAY. A NEW FRONTAL SYSTEM COULD BRING A RETURN OF RAIN SHOWERS LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... A BRIGHT DAY IS IN PROGRESS OVER MOST OF THE THE REGION AS THE THICKER FRONTAL CLOUDS REMAIN OVER NWRN PA FOR THE TIME BEING. RIDGE OF HIGH PRESSURE JUST TO OUR EAST WILL ENSURE DRY CONDITIONS CONTINUING THROUGH THE DAYLIGHT HOURS. WE`LL SEE SERLY WINDS MAINLY IN THE 10-20 MPH RANGE...WITH HIGHER GUSTS OF 20-25 MPH SUPPORTED OVER THE HIGHER ELEVATIONS. THE COLD FRONT SHOULD BE ENTERING THE WESTERN STRIPE OF MY CWA SHORTLY AFTER MIDNIGHT...AND BE EAST OF THE AREA BY SUNRISE. HRRR TIMING SHOWS THE LEADING RAIN SHOWERS MOVING INTO THE AREA BETWEEN ABOUT 10 PM AND MIDNIGHT...WITH COLD AIR CHANGING THE PRECIP TO SNOW SHOWERS BETWEEN ABOUT MIDNIGHT AND 3 AM AS THE FRONT SWEEPS EAST. THE BEST CHANCE FOR MEASURABLE PRECIP WILL BE OVER THE WESTERN AND NORTHERN HIGH TERRAIN WITH SHORT RANGE GUIDANCE ALL AGREEING IN SHOWING THE PRECIP SHIELD DIMINISHING IN COVERAGE AS IT ENTERS CENTRAL AND EASTERN PA. OVER THESE CENTRAL AND EASTERN AREAS VERY LIGHT RAIN SHOWERS WILL TAPER OFF AS LIGHT SNOW SHOWERS OR FLURRIES VERY LATE TONIGHT. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... SUNDAY WILL TURN MARKEDLY COLDER AND BREEZY. THE COLD AIR...WARM LAKES AND MEAN SFC-800MB 250-270 DEG WINDS INDICATE A POTENTIAL FOR SINGLE LAKE ERIE SNOW BAND INITIALLY ALONG THE I-90 CORRIDOR LATER TONIGHT AND SUNDAY MORNING... TRANSITIONING INTO A MORE MULTI-BAND SETUP DURING THE DAY SUNDAY INTO SUNDAY NIGHT. AT THIS TIME...LATEST OPERATIONAL MODELS AND THE SREF IS SUGGESTING 2-4 INCHES OF SNOW POSSIBLE NEAR THE NY BORDER WITH WARREN COUNTY...BUT BEST SNOW IS LIKELY JUST TO THE NORTH OF THE PA/NY BORDER. WE WILL CONTINUE OUR LES WATCH FOR NW WARREN COUNTY AT THIS TIME WITH THE POTENTIAL FOR A FEW OF THE PERENNIAL SNOWBELT LOCATIONS ACROSS FAR NW WARREN COUNTY PICKING UP MINIMAL WARNING CRITERIA SNOWS OF 5-8 INCHES THROUGH MONDAY MORNING. THE REST OF WARREN AND MCKEAN COUNTIES WOULD LIKELY SEE BETWEEN 1 AND 3 INCHES DURING THIS SAME PERIOD. SUNDAY WILL BE COLD AND BREEZY WITH FLURRIES AND A FEW SNOW SHOWERS ACROSS THE LAURELS...AND AND PERHAPS A FEW LIGHT SNOW SHOWERS OR FLURRIES BLEEDING INTO THE CENTRAL MOUNTAINS AT TIMES. HIGH TEMPS WILL RANGE FROM NEAR 32 ACROSS THE NRN AND WRN MOUNTAINS...AND UPPER 30S TO L40S ACROSS THE CENTRAL AND SE VALLEY LOCATIONS. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... LOOKING AT A SEE-SAW WEATHER PATTERN THIS PERIOD AS WE START OFF THE PERIOD WITH A DEEPENING RELATIVE CHILL AS A SERIES OF SHORTWAVE TROFS REINFORCE COOLER AIR ESTABLISHED OVER THE REGION THIS WEEKEND...BEFORE THE START OF THE LONG TERM PERIOD. EARLY NEXT WEEK THE PATTERN IS FORECAST TO TRANSITION TO A ZONAL FLOW THEN HEIGHTS RISE OVER THE EASTERN U.S. IN RESPONSE TO A DIGGING UPPER TROF OVER THE CENTRAL ROCKIES. THE COLD AIR SHOULD SLOWLY EASE ON MONDAY INTO MONDAY NIGHT. WE BOTTOM OUT -1 TO -1.5SD BELOW NORMAL FOR 850 MB TEMPS SUNDAY INTO MONDAY EVENING. AT THE SURFACE HIGH PRESSURE WILL DOMINATE OUR WEATHER TUESDAY TO FRIDAY...THE CENTER OF THE HIGH WILL DRIFT OVER THE WESTERN ATLANTIC...THE PATTERN IMPLIES LOW-LEVEL TRAPPED COLD AIR AS WARM AIR BUILDS IN ALOFT AND A RIDGE BUILDS AT 500 MB TO OUR WEST. A WARM LOOKING PATTERN ABOVE THE SURFACE. THE DEEP SOUTHWEST FLOW IMPLIES INCREASED CHANCE RAIN TOWARD THE WEEKEND BUT NOTHING AT THIS TIME TO FOCUS ON. THE 850 MB TEMPERATURES WILL BE A BIT ABOVE NORMAL BY THANKSGIVING AND PERHAPS INTO EARLY SATURDAY. LOTS OF UNCERTAINTY AND SOME GEFS AND NAEFS MEMBERS SHOW COLD AIR SAGGING SOUTH FRIDAY-SATURDAY. SO THE GEFS SHOWS SLIGHTLY ABOVE NORMAL TEMPERATURES WED-FRIDAY BUT LATE FRIDAY-SATURDAY THE 2M TEMPERATURE PLUMES SHOW HUGE SPREAD AND LOTS OF UNCERTAINTY. WILL IT GET WARM OR A SHALLOW FRONT SLIDE THROUGH? INITIALLY THE MEDIAN IS HIGHER THEN THE MEAN...FRIDAY SHOULD BE WARM...SATURDAY THE MEDIAN IS BELOW THE MEAN...SATURDAY HIGHER PROBABILITY OF BEING COLDER THAN FORECAST AS WE TEND TO THE MEAN. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... MAIN AVIATION CONCERN THIS EVENING WILL BE THE POSSIBILITY OF LLWS...AS CORE OF STRONG WINDS ALOFT OVERSPREAD THE AREA IN ADVANCE OF APPROACHING COLD FRONT. LATEST BUFKIT SOUNDINGS SUPPORT A BRIEF PERIOD OF LLWS CRITERIA ACROSS MUCH OF CENTRAL PA LATE THIS EVENING. COLD FRONT WILL SWEEP THRU CENTRAL PA BTWN 04Z-07Z...ACCOMPANIED BY A FEW SHRA ACROSS THE W MTNS. MVFR CONDS COULD ACCOMPANY THE FRONTAL SHOWERS AT KBFD/KJST. HOWEVER...A BIGGER CONCERN MAY STRONG...GUSTY WSW WINDS ACCOMPANYING AND IMMEDIATELY FOLLOWING THE FRONTAL PASSAGE. HRRR AND LATEST NAM SOUNDINGS INDICATE THE POSSIBILITY OF GUSTS BTWN 35-40KTS AT KBFD/KJST BTWN 04Z-07Z...WITH SOMEWHAT WEAKER GUSTS FURTHER EAST. COLD AIR FLOWING OVER THE GREAT LAKES WILL PRODUCE LAKE EFFECT SNOW SHOWERS ACROSS PORTIONS OF NW PA LATE TONIGHT AND SUNDAY. HOWEVER...LATEST MDL DATA SUGGESTS THE SIG VIS REDUCTIONS WILL REMAIN JUST NORTHWEST OF KBFD. ELSEWHERE...WIDESPREAD VFR CONDS APPEAR VERY LIKELY THRU SUNDAY WITH THE POSSIBLE EXCEPTION OF OCNL MVFR CIGS AT KJST. OUTLOOK...SUNDAY-WEDNESDAY MON-TUE...MVFR WITH CHC -SHSN NW. VFR/NO SIG WX ELSEWHERE. WED-THU...VFR/NO SIG WX. && .CLIMATE... ISSUED AT 148 AM EST SAT NOV 21 2015 WITH 10 DAYS LEFT IN THE MONTH...PRELIMINARY CLIMATE DATA INDICATES THAT NOVEMBER 2015 IS CURRENTLY ON TRACK TO BE THE WARMEST NOVEMBER ON RECORD AT OUR TWO LONG TERM CLIMATE SITES: HARRISBURG AND WILLIAMSPORT. A CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT EACH SITE SINCE 1888 AND 1895 RESPECTIVELY. THROUGH 11/20... THE AVG. MONTHLY TEMPERATURE AT HARRISBURG IS 53.2 DEGREES OR +7.2 DEGREES ABOVE NORMAL. THE AVG. MONTHLY TEMPERATURE AT WILLIAMSPORT IS 50.9 DEGREES OR +7.5 DEGREES ABOVE NORMAL. THE TOP 5 WARMEST NOVEMBERS (CURRENT RANKINGS) MDT: 2015 (53.2), 1931 (51.3), 1975 (50.0), 1999 (49.3), 1994 (49.0) IPT: 2015 (50.9), 1931 (48.8), 1902 (47.3), 2009/1972 (47.2), 1913 (46.3) && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW WATCH FROM 1 AM EST SUNDAY THROUGH LATE SUNDAY NIGHT FOR PAZ004. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...GRUMM/GARTNER AVIATION...FITZGERALD/LA CORTE CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
148 AM EST SAT NOV 21 2015 .SYNOPSIS... HIGH PRESSURE WILL RAPIDLY MOVE OVER AND THEN EAST OF OUR AREA OVERNIGHT AS A FAST WAVE AND COLD FRONT APPROACHES FROM THE WEST SATURDAY AFTERNOON. THIS WILL TRIGGER RAIN TO SNOW SHOWERS OVERNIGHT SATURDAY INTO SUNDAY AND POSSIBLE LAKE EFFECT SNOW IN NORTHWEST PENNSYLVANIA SUNDAY INTO SUNDAY NIGHT. IT WILL BE A TAD COLDER THEN NORMAL SUNDAY-MONDAY. A RIDGE WILL BUILD TO OVER THE CENTRAL US TUESDAY INTO THANKSGIVING PROVIDING A RELATIVELY DRY PERIOD AND WARMING TREND. DEEP SOUTHWESTERLY FLOW LATE NEXT WEEK COULD BRING A CHANCE OF RAIN/RAIN SHOWERS LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 03Z IR LOOP SHOWING MID/HIGH LVL CLOUDINESS MOVING INTO CENTRAL PA...AS WAA ALOFT OVERSPREADS THE REGION AHEAD OF SHORTWAVE OVR THE PLAINS STATES. LATEST NEAR TERM MDL DATA SUGGESTS THE CLOUD COVER WILL BE THICKEST ARND 06Z...THEN THIN OUT AND PUSH NORTHEAST OF THE AREA TOWARD DAWN. THE LGT WIND AND VERY DRY AIR ASSOC WITH SFC HIGH PRES WILL ALLOW TEMPS TO FALL INTO THE 20S FOR MOST OF THE AREA. LATEST HRRR TIMESERIES SHOW TEMPS BOTTOMING OUT ARND 04Z...RISING A BIT AS CLOUDS ARRIVE...THEN REACHING A SECOND MIN AT DAWN. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... RIDGE OF HIGH PRES ALONG THE E COAST SHOULD ENSURE A DRY SATURDAY ACROSS CENTRAL PA. LIGHT WINDS EXPECTED FOR MOST...ALTHOUGH THE HIGHER ELEVATIONS OF THE ALLEGHENY HIGHLANDS WILL SEE SOME INCREASING SOUTHEAST BREEZES IN THE AFTERNOON. BUFKIT SUPPORTS AFTN GUSTS BTWN 20-25KTS. LATEST MDL DATA INDICATES 8-7H BAROCLINIC ZONE AND ASSOC MID LVL CLOUDINESS WILL SHIFT NORTH OF PA ON SATURDAY. WILL MAINTAIN MCLDY SKIES FOR NOW ACROSS THE N MTNS. HOWEVER...MUCH OF CENTRAL PA SHOULD EXPERIENCE A MSUNNY SATURDAY. ENS MEAN 925MB TEMPS NR 2C SHOULD BE SUPPORTIVE OF MAX TEMPS BTWN 45-50F. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... A FAST MOVING WAVE AND STRONG COLD FRONT WILL TRIGGER SOME LIGHT RAIN WHICH WILL TURN TO SNOW QUICKLY IN THE NORTHWESTERN AREAS SATURDAY NIGHT. FARTHER EAST VERY LIGHT RAIN LIKELY ENDING AS SNOW SHOWERS OR FLURRIES SUNDAY. IT WILL TURN MARKEDLY COLDER EARLY SUNDAY AND BREEZY. THE COLD AIR...WARM LAKES AND WESTERLY WINDS INDICATE A POTENTIAL ERIE SNOW BAND. AT THIS TIME SREF IS SUGGESTING 2-4 INCHES POSSIBLE NEAR NY BORDER...BUT BEST SNOW IS LIKELY TO THE NORTH OF THE PA/NY BORDER. WE WILL WAIT TO SEE 3KM NCAR ENSEMBLE TONIGHT AND HOW IT FORECASTS THE SNOW. WE SHOWED GENERALLY 1-3 INCHES AT THIS TIME IN THE LES EVENT AND WILL WAIT FOR HIGHER RESOLUTION GUIDANCE. SUNDAY WILL BE COLD AND BREEZY. THE COLD AIR SHOULD SLOWLY EASE ON MONDAY INTO MONDAY NIGHT. WE BOTTOM OUT -1 TO -1.5SD BELOW NORMAL FOR 850 MB TEMPS SUNDAY INTO MONDAY EVENING. AT THE SURFACE HIGH PRESSURE WILL DOMINATE OUR WEATHER TUESDAY TO FRIDAY...THE CENTER OF THE HIGH WILL DRIFT OVER THE WESTERN ATLANTIC...THE PATTERN IMPLIES LOW-LEVEL TRAPPED COLD AIR AS WARM AIR BUILDS IN ALOFT AND A RIDGE BUILDS AT 500 MB TO OUR WEST. A WARM LOOKING PATTERN ABOVE THE SURFACE. THE DEEP SOUTHWEST FLOW IMPLIES INCREASED CHANCE RAIN TOWARD THE WEEKEND BUT NOTHING AT THIS TIME TO FOCUS ON. THE 850 MB TEMPERATURES WILL BE A BIT ABOVE NORMAL BY THANKSGIVING AND PERHAPS INTO EARLY SATURDAY. LOTS OF UNCERTAINTY AND SOME GEFS AND NAEFS MEMBERS SHOW COLD AIR SAGGING SOUTH FRIDAY-SATURDAY. SO THE GEFS SHOWS SLIGHTLY ABOVE NORMAL TEMPERATURES WED-FRIDAY BUT LATE FRIDAY-SATURDAY THE 2M TEMPERATURE PLUMES SHOW HUGE SPREAD AND LOTS OF UNCERTAINTY. WILL IT GET WARM OR A SHALLOW FRONT SLIDE THROUGH? INITIALLY THE MEDIAN IS HIGHER THEN THE MEAN...FRIDAY SHOULD BE WARM...SATURDAY THE MEDIAN IS BELOW THE MEAN...SATURDAY HIGHER PROBABILITY OF BEING COLDER THAN FORECAST AS WE TEND TO THE MEAN. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT... ISSUED AT 120 AM EST SAT NOV 21 2015... VFR WILL CONTINUE TODAY WITH SOME DETERIORATION IN FLYING CONDITIONS EXPECTED LATER SATURDAY NIGHT INTO EARLY SUNDAY. SFC WINDS FROM 100-150 DEGREES WILL INCREASE AS LOW PRESSURE INTENSIFIES TRACKING ENEWD FROM THE LOWER OH VALLEY INTO THE LOWER GREAT LAKES. ADDED LLWS TO THE WESTERN TAFS DUE TO 40-50KT SOUTHERLY LOW LEVEL FLOW IN ADVANCE OF THE LOW AND TRAILING COLD FRONT. RAIN SHOWERS SHOULD REACH THE WESTERN 1/3 OF THE AIRSPACE BY 06Z SATURDAY AND EVENTUALLY TRANSITION TO -SHSN WITH IFR VIS POSSIBLE AT BFD. OUTLOOK...SUNDAY-WEDNESDAY SUN...MVFR CIGS WEST TO VFR EAST. IFR VIS PSBL NW IN SHSN. MON...MVFR/VFR CIGS WEST. VFR CENTRAL/EAST. NO SIG WX. TUE...MVFR WITH CHC -SHSN NW. VFR/NO SIG WX ELSEWHERE. WED...VFR/NO SIG WX. && .CLIMATE... ISSUED AT 148 AM EST SAT NOV 21 2015 WITH 10 DAYS LEFT IN THE MONTH...PRELIMINARY CLIMATE DATA INDICATES THAT NOVEMBER 2015 IS CURRENTLY ON TRACK TO BE THE WARMEST NOVEMBER ON RECORD AT OUR TWO LONG TERM CLIMATE SITES: HARRISBURG AND WILLIAMSPORT. A CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT EACH SITE SINCE 1888 AND 1895 RESPECTIVELY. THROUGH 11/20... THE AVG. MONTHLY TEMPERATURE AT HARRISBURG IS 53.2 DEGREES OR +7.2 DEGREES ABOVE NORMAL. THE AVG. MONTHLY TEMPERATURE AT WILLIAMSPORT IS 50.9 DEGREES OR +7.5 DEGREES ABOVE NORMAL. THE TOP 5 WARMEST NOVEMBERS (CURRENT RANKINGS) MDT: 2015 (53.2), 1931 (51.3), 1975 (50.0), 1999 (49.3), 1994 (49.0) IPT: 2015 (50.9), 1931 (48.8), 1902 (47.3), 2009/1972 (47.2), 1913 (46.3) && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/DEVOIR NEAR TERM...FITZGERALD SHORT TERM...DEVOIR/FITZGERALD LONG TERM...GRUMM AVIATION...STEINBUGL CLIMATE...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
123 AM EST SAT NOV 21 2015 .SYNOPSIS... HIGH PRESSURE WILL RAPIDLY MOVE OVER AND THEN EAST OF OUR AREA OVERNIGHT AS A FAST WAVE AND COLD FRONT APPROACHES FROM THE WEST SATURDAY AFTERNOON. THIS WILL TRIGGER RAIN TO SNOW SHOWERS OVERNIGHT SATURDAY INTO SUNDAY AND POSSIBLE LAKE EFFECT SNOW IN NORTHWEST PENNSYLVANIA SUNDAY INTO SUNDAY NIGHT. IT WILL BE A TAD COLDER THEN NORMAL SUNDAY-MONDAY. A RIDGE WILL BUILD TO OVER THE CENTRAL US TUESDAY INTO THANKSGIVING PROVIDING A RELATIVELY DRY PERIOD AND WARMING TREND. DEEP SOUTHWESTERLY FLOW LATE NEXT WEEK COULD BRING A CHANCE OF RAIN/RAIN SHOWERS LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 03Z IR LOOP SHOWING MID/HIGH LVL CLOUDINESS MOVING INTO CENTRAL PA...AS WAA ALOFT OVERSPREADS THE REGION AHEAD OF SHORTWAVE OVR THE PLAINS STATES. LATEST NEAR TERM MDL DATA SUGGESTS THE CLOUD COVER WILL BE THICKEST ARND 06Z...THEN THIN OUT AND PUSH NORTHEAST OF THE AREA TOWARD DAWN. THE LGT WIND AND VERY DRY AIR ASSOC WITH SFC HIGH PRES WILL ALLOW TEMPS TO FALL INTO THE 20S FOR MOST OF THE AREA. LATEST HRRR TIMESERIES SHOW TEMPS BOTTOMING OUT ARND 04Z...RISING A BIT AS CLOUDS ARRIVE...THEN REACHING A SECOND MIN AT DAWN. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... RIDGE OF HIGH PRES ALONG THE E COAST SHOULD ENSURE A DRY SATURDAY ACROSS CENTRAL PA. LIGHT WINDS EXPECTED FOR MOST...ALTHOUGH THE HIGHER ELEVATIONS OF THE ALLEGHENY HIGHLANDS WILL SEE SOME INCREASING SOUTHEAST BREEZES IN THE AFTERNOON. BUFKIT SUPPORTS AFTN GUSTS BTWN 20-25KTS. LATEST MDL DATA INDICATES 8-7H BAROCLINIC ZONE AND ASSOC MID LVL CLOUDINESS WILL SHIFT NORTH OF PA ON SATURDAY. WILL MAINTAIN MCLDY SKIES FOR NOW ACROSS THE N MTNS. HOWEVER...MUCH OF CENTRAL PA SHOULD EXPERIENCE A MSUNNY SATURDAY. ENS MEAN 925MB TEMPS NR 2C SHOULD BE SUPPORTIVE OF MAX TEMPS BTWN 45-50F. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... A FAST MOVING WAVE AND STRONG COLD FRONT WILL TRIGGER SOME LIGHT RAIN WHICH WILL TURN TO SNOW QUICKLY IN THE NORTHWESTERN AREAS SATURDAY NIGHT. FARTHER EAST VERY LIGHT RAIN LIKELY ENDING AS SNOW SHOWERS OR FLURRIES SUNDAY. IT WILL TURN MARKEDLY COLDER EARLY SUNDAY AND BREEZY. THE COLD AIR...WARM LAKES AND WESTERLY WINDS INDICATE A POTENTIAL ERIE SNOW BAND. AT THIS TIME SREF IS SUGGESTING 2-4 INCHES POSSIBLE NEAR NY BORDER...BUT BEST SNOW IS LIKELY TO THE NORTH OF THE PA/NY BORDER. WE WILL WAIT TO SEE 3KM NCAR ENSEMBLE TONIGHT AND HOW IT FORECASTS THE SNOW. WE SHOWED GENERALLY 1-3 INCHES AT THIS TIME IN THE LES EVENT AND WILL WAIT FOR HIGHER RESOLUTION GUIDANCE. SUNDAY WILL BE COLD AND BREEZY. THE COLD AIR SHOULD SLOWLY EASE ON MONDAY INTO MONDAY NIGHT. WE BOTTOM OUT -1 TO -1.5SD BELOW NORMAL FOR 850 MB TEMPS SUNDAY INTO MONDAY EVENING. AT THE SURFACE HIGH PRESSURE WILL DOMINATE OUR WEATHER TUESDAY TO FRIDAY...THE CENTER OF THE HIGH WILL DRIFT OVER THE WESTERN ATLANTIC...THE PATTERN IMPLIES LOW-LEVEL TRAPPED COLD AIR AS WARM AIR BUILDS IN ALOFT AND A RIDGE BUILDS AT 500 MB TO OUR WEST. A WARM LOOKING PATTERN ABOVE THE SURFACE. THE DEEP SOUTHWEST FLOW IMPLIES INCREASED CHANCE RAIN TOWARD THE WEEKEND BUT NOTHING AT THIS TIME TO FOCUS ON. THE 850 MB TEMPERATURES WILL BE A BIT ABOVE NORMAL BY THANKSGIVING AND PERHAPS INTO EARLY SATURDAY. LOTS OF UNCERTAINTY AND SOME GEFS AND NAEFS MEMBERS SHOW COLD AIR SAGGING SOUTH FRIDAY-SATURDAY. SO THE GEFS SHOWS SLIGHTLY ABOVE NORMAL TEMPERATURES WED-FRIDAY BUT LATE FRIDAY-SATURDAY THE 2M TEMPERATURE PLUMES SHOW HUGE SPREAD AND LOTS OF UNCERTAINTY. WILL IT GET WARM OR A SHALLOW FRONT SLIDE THROUGH? INITIALLY THE MEDIAN IS HIGHER THEN THE MEAN...FRIDAY SHOULD BE WARM...SATURDAY THE MEDIAN IS BELOW THE MEAN...SATURDAY HIGHER PROBABILITY OF BEING COLDER THAN FORECAST AS WE TEND TO THE MEAN. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT... ISSUED AT 120 AM EST SAT NOV 21 2015... VFR WILL CONTINUE TODAY WITH SOME DETERIORATION IN FLYING CONDITIONS EXPECTED LATER SATURDAY NIGHT INTO EARLY SUNDAY. SFC WINDS FROM 100-150 DEGREES WILL INCREASE AS LOW PRESSURE INTENSIFIES TRACKING ENEWD FROM THE LOWER OH VALLEY INTO THE LOWER GREAT LAKES. ADDED LLWS TO THE WESTERN TAFS DUE TO 40-50KT SOUTHERLY LOW LEVEL FLOW IN ADVANCE OF THE LOW AND TRAILING COLD FRONT. RAIN SHOWERS SHOULD REACH THE WESTERN 1/3 OF THE AIRSPACE BY 06Z SATURDAY AND EVENTUALLY TRANSITION TO -SHSN WITH IFR VIS POSSIBLE AT BFD. OUTLOOK...SUNDAY-WEDNESDAY SUN...MVFR CIGS WEST TO VFR EAST. IFR VIS PSBL NW IN SHSN. MON...MVFR/VFR CIGS WEST. VFR CENTRAL/EAST. NO SIG WX. TUE...MVFR WITH CHC -SHSN NW. VFR/NO SIG WX ELSEWHERE. WED...VFR/NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/DEVOIR NEAR TERM...FITZGERALD SHORT TERM...DEVOIR/FITZGERALD LONG TERM...GRUMM AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
302 AM EST SAT NOV 21 2015 .SHORT TERM (TODAY AND TONIGHT)... TRANQUIL WEATHER CONDITIONS ACROSS THE AREA EARLY THIS MORNING. CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A LARGE SCALE TROUGH ACROSS THE CENTRAL CONUS. AT THE SURFACE...HIGH PRESSURE IS IN PLACE ACROSS THE MID-ATLANTIC WITH A SURFACE LOW CURRENTLY ACROSS SOUTHERN MISSOURI WITH A COLD FRONT TRAILING INTO THE SOUTHERN PLAINS. TEMPERATURES SHOULD WARM QUICKLY INTO THE MID 50S BY LATE THIS MORNING AS THE SURFACE LOW TRACKS TO THE NORTH OF THE AREA THIS AFTERNOON. MOISTURE RETURN WITH THE SYSTEM WILL NOT BE OVERLY IMPRESSIVE. IT WILL TAKE SOME TIME BEFORE LOW LEVEL WINDS SWITCH AROUND TO THE SOUTH WITH THE SURFACE HIGH TO THE NORTHEAST. THIS DELAY WILL CREATE A BRIEF AND NARROW WINDOW OF DEWPOINTS IN THE 40S AND PW VALUES IN THE 0.75-0.85 INCH RANGE. THESE VALUES ARE A BIT ABOVE NORMAL FOR THIS TIME OF YEAR...BUT AGAIN THIS MOISTURE IS NOT EXPECTED TO LAST LONG. HAVE CONTINUED WITH THE HIGHEST POPS AFTER 3PM WITH THE MOISTURE BEING LIMITED TO RIGHT ALONG THE FRONTAL BOUNDARY. THE COLDEST AIR OF THE SEASON WILL MOVE IN BEHIND THE FRONT LATE THIS EVENING INTO THE OVERNIGHT HOURS. ALL OF THE MODELS INDICATE ENOUGH MOISTURE HANGING AROUND FOR A FEW LIGHT SNOW SHOWERS/FLURRIES ACROSS THE HIGHER TERRAIN. AGAIN...MOISTURE IS EXTREMELY LIMITED BUT THERE WILL BE SOME OROGRAPHIC LIFT WITH LIMITED LOW LEVEL MOISTURE IN PLACE. IT APPEARS THE BEST TIME FOR SNOW IN THE HIGH TERRAIN WILL BE FROM 06-12Z SUNDAY. THERE COULD BE SOME MINOR ACCUMULATIONS OF UP TO HALF AN INCH IN THE HIGHEST TERRAIN LATE TONIGHT INTO EARLY TOMORROW MORNING. .LONG TERM (SUNDAY THROUGH FRIDAY)... THE EXTENDED BEGINS WITH VERY COLD AIR MOVING INTO THE SOUTHERN APPALACHIAN REGION. HIGHS ON SUNDAY WILL STRUGGLE TO REACH INTO THE 40S ACROSS THE TN VALLEY...WITH ONLY 30S OVER THE MOUNTAINS. COLD AIR CONTINUES TO PUSH IN SUNDAY NIGHT WITH LOWS FALLING INTO THE TEENS IN THE MOUNTAINS AND 20S ACROSS LOWER VALLEY LOCATIONS. TEMPERATURES WILL SLOWLY BEGIN TO MODERATE ON MONDAY AS FLOW ALOFT BEGINS LESS NORTHERLY. HOWEVER...THE WARMING TREND WILL BEGIN IN EARNEST TUESDAY AND WEDNESDAY AS UPPER FLOW BECOME ZONAL. BY THURSDAY AND FRIDAY...AN UPPER RIDGE BUILDS INTO THE REGION ALLOWING DAYTIME HIGHS TO ONCE AGAIN REACH INTO THE 60S ACROSS MUCH LOWER ELEVATIONS. OVERALL...WE WILL BE IN A QUIET WEATHER PATTERN WITH DRY CONDITIONS EXPECTED THROUGHOUT THE EXTENDED. ONLY CONCERN WILL BE AN APPROACHING WEATHER SYSTEM ON FRIDAY. CURRENT MODEL RUNS BEGIN TO BRING MID AND HIGH CLOUDS IN BY FRIDAY BUT FOR NOW KEEP ASSOCIATED PRECIP TO THE WEST UNTIL AFTER THE EXTENDED PERIOD. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 59 33 46 27 / 20 20 0 0 KNOXVILLE MCGHEE TYSON AIRPORT, TN 60 33 43 23 / 20 40 10 0 OAK RIDGE, TN 60 33 42 23 / 30 30 0 0 TRI CITIES AIRPORT, TN 58 32 41 20 / 10 40 10 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ MA/MJB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1118 PM CST FRI NOV 20 2015 .UPDATE... ISSUED AT 740 PM CST FRI NOV 20 2015 LOOKING A LOT MORE LIKE LATE NOVEMBER OUT THERE...AT LEAST FOR PARTS OF THE AREA. NICE TO SEE THAT THIS STORM SYSTEM OVERALL IS UNFOLDING AS EXPECTED THE PAST 24-36 HOURS...WITH INCOMING AMOUNTS ACROSS MUCH OF THE CURRENT WARNING AREA MAINLY IN THE 4-7 INCH RANGE SO FAR...HEAVIEST OF COURSE WHERE INDIVIDUAL STRONGER FGEN BANDED ELEMENTS HAVE LAID OUT THE LONGEST...PRIMARILY SOUTH OF HIGHWAY 18. FARTHER NORTH...AMOUNTS HAVE TAPERED CONSIDERABLY... GENERALLY ONLY PUSHING AN INCH OR TWO ALONG THE IA/MN BORDER PER REPORTS...AND ONLY A DUSTING TO PERHAPS A HALF INCH JUST SOUTH OF THE I-90 CORRIDOR. THESE AMOUNTS ARE PRETTY MUCH IN LINE WITH EARLIER THINKING.. DON`T PLAN ANY BIG CHANGES TO GOING HEADLINES...THOUGH MAY ULTIMATELY HAVE TO DITCH THE WARNING FOR RICHLAND COUNTY PER RADAR TRENDS...AS THE STRONGER FGEN BAND HAS REALLY WEAKENED OVER THAT AREA THE PAST HOUR OR TWO. ALSO...WILL LIKELY NEED TO SPEED UP THE EXIT TIME OF WIDESPREAD PRECIP PER RADAR TRENDS...THOUGH WITH THE ARRIVAL OF THE ACTUAL UPPER WAVE...WE MAY TEND TO SEE SOME REDEVELOPMENT WITHIN AN ELONGATING MID LEVEL DEFORMATION AXIS INTO FAR SOUTHWEST WISCONSIN AND NORTHEAST IOWA. REGARDLESS OF THE ACTUAL TIME...CURRENT HEADLINES DO COVER THE BIGGER ISSUE...WHICH HAS BEEN IMPACT WITH QUITE A FEW REPORTS OF ACCIDENTS...CERTAINLY NOT HELPED BY THE FACT THAT THIS IS THE FIRST EVENT OF THE SEASON. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 217 PM CST FRI NOV 20 2015 HAVE BEEN TRYING TO INTEGRATE CURRENT RADAR AND SURFACE OBSERVATIONS INTO THE FORECAST TO FINE TUNE STORM. BOTTOM LINE IS THE ADVISORIES AND WARNINGS LOOK ON TRACK FOR LOCATION. WE DID UPDATE THE START TIME. HAVE LEFT THE END TIME ON SATURDAY AS THE NORTHWEST WINDS OF 15 TO 25 MPH WILL CAUSE SOME DRIFTING... ESPECIALLY ON THE HIGHER TERRAIN OF SWRN WI AND NERN IA. CURRENT SNOW BAND IS IMPRESSIVE WITH AMOUNTS NEAR 15 INCHES NEAR SIOUX FALLS SD TODAY AND MESSY ROADS EXTENDING NOW INTO PARTS OF NERN IA UNDER THE SNOW BAND. GIVEN A MODERATE SNOW RATE IN THE CENTRAL-EASTERN IA SNOW BAND...ACCUMULATING SNOW AND SLICK ROADS HAPPEN FAIRLY QUICK AFTER ONSET. THIS BAND IS WELL REPRESENTED BY 600-700 MB FRONTOGENESIS FORCING PER RAP ANALYSIS. THE BAND SHOULD CONTINUE TO SHIFT NORTHEAST THROUGH EARLY EVENING. PER VIGOROUS SHORTWAVE TROUGH IN KS/NEB MOVING AT US...THE FRONTOGENESIS THEN REINVIGORATES A BIT LATER EVENING ON A NE-SW ARC OVER THE SOUTHERN FORECAST AREA...WITH THE MAIN HEAVY SNOW BAND NEAR HIGHWAY 20 TO I-80 WITH STRONGER FRONTOGENESIS INDICATED IN THE SHORT TERM MODELS. BIG PICTURE REMAINS THE SAME FOR THIS STORM. WE HAVEN`T CHANGED THE TOTAL LIQUID FROM THIS STORM MUCH...BUT DO HAVE SOME CONCERNS WITH SNOW RATIOS IN THE WARNING...ESPECIALLY CLOSER TO DUBUQUE AND THE SOUTHERN HALF OF THE FAYETTE-CLAYTON-GRANT COUNTIES. THE LATEST RAP AND 20.12Z NAM/GFS OUTPUT RUN THROUGH THE DENDRITIC GROWTH ZONE COBB TECHNIQUE SUGGEST RATIOS COULD BE IN THE 20-24 TO 1 RANGE. WE HAVE INCREASED THOSE RATIOS TO 17 TO 1 ACROSS THE WARNING WITH A 150-200 MB DENDRITE GROWTH ZONE SUGGESTED. THIS RAISES TOTALS TOWARD A FOOT. WINDS WILL INCREASE ACROSS THE SOUTH INTO THE 15 TO 25 MPH RANGE SATURDAY FOR A BIT OF DRIFTING SNOW. MAIN MESSAGE IS THE SAME...WITH POSSIBLY A BIT MORE IMPACT ACROSS THE FAR SOUTH /IA HIGHWAY 3/ WITH 10-12 INCHES AND SOME DRIFTING SNOW. BELIEVE ACCUMULATING SNOW WILL REALLY BE SOUTH OF I-90...AND THE HAZARDS LOOK LIKE THEY ARE PLACED WELL. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 217 PM CST FRI NOV 20 2015 NORTHWEST FLOW CONTINUES WITH A COLD WEEKEND. CONSENSUS DETERMINISTIC MODEL RUNS FROM 20.12Z AGREED WELL ON A DYNAMIC SYSTEM SHIFTING THROUGH NERN WI RAPIDLY SUNDAY NIGHT. THIS LOOKS LIKE IT COULD SPREAD SOME SNOW ACROSS NORTHCENTRAL WI...LEAVING BY MONDAY. THE WEEK THEN BEGINS TO WARM AS ANOTHER LONGWAVE TROUGH DIGS IN THE WEST. BY MID-WEEK PRECIPITATION WORKS INTO THE AREA ON A MOIST FLOW. A CLOUDY PERIOD WITH POSSIBLY PRECIPITATION TYPE ISSUES. AT THIS TIME IT APPEARS MAINLY LIKE A RAIN/SNOW SCENARIO BUT DEPENDING ON HOW MOISTURE ARRIVES...SOME FREEZING DRIZZLE COULD BE AROUND. THE MAIN IDEA NOW IS WARMING AND PRECIPITATION BY MID-WEEK INTO THANKSGIVING. CONFIDENCE MODERATE WITH GOOD && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1118 PM CST FRI NOV 20 2015 SNOW WILL WIND DOWN FROM WEST TO EAST FOR BOTH KRST AND KLSE THROUGH 07Z...LEAVING LINGERING MID CLOUDS FOR A TIME BEFORE THINGS CLEAR BY SUNRISE. HOWEVER...THERE REMAINS CONSIDERABLE QUESTIONS ABOUT JUST HOW MUCH ADDITIONAL STRATOCUMULUS WE MIGHT BE ABLE TO MUSTER UP HEADING INTO MIDDAY AND THE AFTERNOON...WITH QUITE CHILLY AIR ALOFT BUT DRYING DOWN LOW. UPSTREAM CLOUD TRENDS ARE SOMEWHAT TELLING...WITH A STEADY SOUTHWARD EXPANSION OF LOWER STRATUS. HOWEVER...ARRIVAL OF THAT STUFF DURING PEAK HEATING (SUCH AS IT IS IN LATE NOVEMBER) DOES SUGGEST THINGS WILL REMAIN MORE SCATTERED AT THIS TIME. DEFINITELY SOMETHING TO WATCH CLOSELY FOR AVIATION INTERESTS...AS ANY CEILING TODAY WILL LIKELY BE MVFR. OTHERWISE...A RETURN TO CLEAR SKIES IS EXPECTED TONIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR WIZ054-055-061. WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR WIZ053. MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR MNZ094-095. WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR MNZ096. IA...WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR IAZ008-009-018- 019. WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR IAZ010-011-029- 030. && $$ UPDATE...LAWRENCE SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...LAWRENCE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1025 PM CST FRI NOV 20 2015 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .UPDATE... ISSUED AT 1006 PM CST FRI NOV 20 2015 LATEST TREND OF THE HRRR SUPPORTS THE 00Z NAM TO KEEP THE ACCUM SNOW FURTHER SOUTH. WILL CANCEL THE ADVISORY. UPDATE ISSUED AT 915 PM CST FRI NOV 20 2015 TREND OF THE LAST FEW HOURS INDICATE A SOUTHERN SHIFT WITH THE HEAVY SNOW BAND OVER SOUTHERN WISCONSIN. GRB SOUNDING THIS EVENING SUGGESTS A LOT OF DRY AIR TO OVERCOME. BEST 850-700 FGEN REGION WELL SOUTH. NORMALLY WOULD DROP THE ADVISORY WITH AMOUNTS MINIMAL...BUT NEED TO CONSIDER THE FIRST SNOW OF THE SEASON. THE 00Z NAM INDICATES A DIRECTION OF DROPPING THE ADVISORY...WILL TRY TO TAKE A QUICK PEAK AT THE EARLY PART OF THE GFS THE NEXT HOUR...AND GO FROM THERE. WE DO HAVE THE UPPER TROUGH DROPPING IN TONIGHT INTO SATURDAY WHICH COULD PIVOT THE LIGHTER SNOW NORTH A BIT...BUT THIS SYSTEM IS ALSO TRACKING A BIT FASTER. && .SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 242 PM CST FRI NOV 20 2015 PRIMARY FOCUS TO BE ON THE SNOW POTENTIAL OVER SRN SECTIONS OF THE FCST AREA LATE TNGT/SAT MORNING AS A SYSTEM PASSES BY TO OUR SOUTH. MODEL INCONSISTENCY HAS BEEN A PROBLEM ALL WEEK...BUT IT NOW APPEARS THAT THE 12Z RUN HAS AT LEAST TRIED TO ZERO ON A TRACK/NRN EDGE OF SNOW. A SECONDARY FOCUS TO BE ON INCREASING LK EFFECT FOR N-CNTRL WI AS WINDS GRADUALLY SHIFT TO THE NW AND COLD AIR FLOWS OVER LK SUPERIOR. THE 20Z MSAS SFC ANALYSIS SHOWED AN AREA OF HI PRES OVER THE OHIO RIVER VALLEY WITH STRONG LOW PRES OVER HUDSON BAY AND WEAK LOW PRES OVER THE CNTRL HI PLAINS. RADAR MOSAIC INDICATED A NARROW... BUT INTENSE BAND OF SNOW OVER SE SD...NE NEBRASKA AND NRN IA. SNOWFALL RATES WITHIN THIS INTENSE BAND WERE 2-3" PER HOUR! EVEN AT THIS LATE DATE...THE NRN EDGE OF THE MAIN SNOW BAND WAS NOT SET IN STONE AS THE MODELS CONTINUED TO TWEAK NORTH (NAM/GFS) OR SOUTH (GEM). MODELS DO AGREE ON THE STRONG FRONTOGENETICAL FORCING SIGNAL THAT RUNS FROM CNTRL IA E-NE INTO SRN WI/NRN IL TNGT...THUS HIGHEST ACCUMULATION NUMBERS WL STAY TO OUR SOUTH. HOWEVER...DO ANTICIPATE LIGHT ACCUMULATIONS (< 1") ALONG OUR SRN TIER OF COUNTIES BY DAYBREAK. WE WL ALSO HAVE TO WATCH SFC WINDS AS ANY SLIGHT VEERING TO THE NE COULD ADD TO ACCUMULATIONS OVER MANITOWOC COUNTY. LIGHT SNOW WL CONT OVER E-CNTRL WI THRU AT LEAST SAT MORNING AS THE SFC LOW LIFTS NE FROM THE MID-MS VALLEY TOWARD THE ERN GREAT LAKES AND MID-LEVEL FRONTOGENETICAL FORCING BEGINS TO SHIFT FROM SE WI INTO LWR MI. AN ADDITIONAL INCH OR TWO OF ACCUMULATION IS POSSIBLE OVER E-CNTRL WI...THUS PLAN ON ISSUING A WINTER WEATHER ADVY FOR WINNEBAGO...CALUMET AND MANITOWOC COUNTIES FROM 03Z-21Z SAT (PRIMARILY FOR SRN SECTIONS OF THESE COUNTIES). TRAILING THIS SYSTEM IS A SHRTWV TROF THAT IS FCST TO SWEEP INTO THE WRN GREAT LAKES ON SAT. WHILE THE BULK OF THE SYNOPTIC MOISTURE TO BE TIED UP WITH THE INITIAL STORM...WINDS ARE EXPECTED TO TURN NW AND INTRODUCE LK EFFECT SNOW SHWRS TO N-CNTRL WI. THERE IS A POTENTIAL FOR AN INCH OR TWO OF ACCUMULATION...ESPECIALLY OVER THE SNOWBELT REGION OF VILAS CNTY. MAX TEMPS TO ONLY BE IN THE MID TO UPR 20S N-CNTRL...TO THE MID 30S E-CNTRL WI. ADD IN A NW WIND AT 10 TO 20 MPH AND WIND CHILL VALUES WL ONLY BE IN THE UPR TEENS TO LWR 20S. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 242 PM CST FRI NOV 20 2015 SEVERAL CONCERNS TO DEAL WITH INCLUDE LAKE EFFECT SNOW SHOWERS ACROSS THE NORTH SATURDAY NIGHT INTO SUNDAY MORNING...A CLIPPER SYSTEM SUNDAY NIGHT INTO MONDAY MORNING AND THEN ABOVE NORMAL TEMPERATURES AND UNSETTLED WEATHER FOR THANKSGIVING DAY AND BLACK FRIDAY. PERUSAL OF THE BUFKIT SOUNDING OVER WESTERN LAKE SUPERIOR SATURDAY NIGHT PRETTY IMPRESSIVE SATURDAY NIGHT. ABUNDANT MOISTURE UP TO TEN THOUSAND FEET...EQL LEVELS OF TWELVE TO FIFTEEN THOUSAND FEET AND LAKE TO 850MB TEMPERATURE DIFFERENCES APPROACHING 20C. LOW LEVEL WINDS ARE NOT AS FAVORABLE...BUT CLOSE ENOUGH TO WARRANT INCREASING SNOWFALL TOTALS FROM PREVIOUS FORECAST. CONTEMPLATED LAKE EFFECT SNOW WATCH THINKING THE SNOW BELT REGION OF VILAS COUNTY COULD SEE OVER 6 INCHES IN A FEW SPOTS IF BANDS SET UP. PER COORDINATION WITH DULUTH AND MARQUETTE...WILL HOLD OFF FOR NOW AND MIDNIGHT SHIFT MAY GO WITH AN ADVISORY. A CLIPPER SYSTEM WILL MOVE ACROSS THE REGION SUNDAY NIGHT...BRINGING A CHANCE OF LIGHT SNOW ACROSS THE SOUTH AND LIGHT SNOW LIKELY ACROSS THE NORTH. AN INCH OR TWO IS EXPECTED ACROSS THE NORTH WITH LIGHTER AMOUNTS TO THE SOUTH. ATTENTION THEN TURNS TO WEDNESDAY THROUGH FRIDAY WITH AN UNSETTLED PERIOD EXPECTED. PRECIPITATION SHOULD BE MAINLY RAIN ACROSS CENTRAL AND NORTHEAST WISCONSIN...WITH MORE OF A MIX OF RAIN AND SNOW ACROSS NORTH-CENTRAL WISCONSIN. LATEST ECMWF HAS PUSHED THE FRONT FURTHER SOUTH ON FRIDAY WHERE THE NORTH MAY BE DRY. PLENTY OF TIME TO WORK OUT THE DETAILS. BELOW NORMAL TEMPERATURES THIS WEEKEND SHOULD RETURN TO OR ABOVE NORMAL BY THE MIDDLE OF NEXT WEEK. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1025 PM CST FRI NOV 20 2015 VFR CIGS EXPECTED OVER MOST AREAS TONIGHT INTO SATURDAY. EXCEPTIONS INCLUDE LOCALIZED MVFR CIGS WITH LIGHT SNOW MAINLY SOUTH OF HIGHWAY 10 INCLUDING THE ATW AND MTW TAFS OVERNIGHT INTO SATURDAY. ANOTHER EXCEPTION FOR PATCHY MVFR CIGS AND VSBYS INCLUDE NORTH CENTRAL WISCONSIN LATE TONIGHT INTO SATURDAY NIGHT WITH INCLUDES THE RHI TAF. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE.........TDH SHORT TERM.....KALLAS LONG TERM......ECKBERG AVIATION.......TDH
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
1006 PM CST FRI NOV 20 2015 NEW INFORMATION ADDED TO UPDATE SECTION .UPDATE... ISSUED AT 1006 PM CST FRI NOV 20 2015 LATEST TREND OF THE HRRR SUPPORTS THE 00Z NAM TO KEEP THE ACCUM SNOW FURTHER SOUTH. WILL CANCEL THE ADVISORY. UPDATE ISSUED AT 915 PM CST FRI NOV 20 2015 TREND OF THE LAST FEW HOURS INDICATE A SOUTHERN SHIFT WITH THE HEAVY SNOW BAND OVER SOUTHERN WISCONSIN. GRB SOUNDING THIS EVENING SUGGESTS A LOT OF DRY AIR TO OVERCOME. BEST 850-700 FGEN REGION WELL SOUTH. NORMALLY WOULD DROP THE ADVISORY WITH AMOUNTS MINIMAL...BUT NEED TO CONSIDER THE FIRST SNOW OF THE SEASON. THE 00Z NAM INDICATES A DIRECTION OF DROPPING THE ADVISORY...WILL TRY TO TAKE A QUICK PEAK AT THE EARLY PART OF THE GFS THE NEXT HOUR...AND GO FROM THERE. WE DO HAVE THE UPPER TROUGH DROPPING IN TONIGHT INTO SATURDAY WHICH COULD PIVOT THE LIGHTER SNOW NORTH A BIT...BUT THIS SYSTEM IS ALSO TRACKING A BIT FASTER. && .SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 242 PM CST FRI NOV 20 2015 PRIMARY FOCUS TO BE ON THE SNOW POTENTIAL OVER SRN SECTIONS OF THE FCST AREA LATE TNGT/SAT MORNING AS A SYSTEM PASSES BY TO OUR SOUTH. MODEL INCONSISTENCY HAS BEEN A PROBLEM ALL WEEK...BUT IT NOW APPEARS THAT THE 12Z RUN HAS AT LEAST TRIED TO ZERO ON A TRACK/NRN EDGE OF SNOW. A SECONDARY FOCUS TO BE ON INCREASING LK EFFECT FOR N-CNTRL WI AS WINDS GRADUALLY SHIFT TO THE NW AND COLD AIR FLOWS OVER LK SUPERIOR. THE 20Z MSAS SFC ANALYSIS SHOWED AN AREA OF HI PRES OVER THE OHIO RIVER VALLEY WITH STRONG LOW PRES OVER HUDSON BAY AND WEAK LOW PRES OVER THE CNTRL HI PLAINS. RADAR MOSAIC INDICATED A NARROW... BUT INTENSE BAND OF SNOW OVER SE SD...NE NEBRASKA AND NRN IA. SNOWFALL RATES WITHIN THIS INTENSE BAND WERE 2-3" PER HOUR! EVEN AT THIS LATE DATE...THE NRN EDGE OF THE MAIN SNOW BAND WAS NOT SET IN STONE AS THE MODELS CONTINUED TO TWEAK NORTH (NAM/GFS) OR SOUTH (GEM). MODELS DO AGREE ON THE STRONG FRONTOGENETICAL FORCING SIGNAL THAT RUNS FROM CNTRL IA E-NE INTO SRN WI/NRN IL TNGT...THUS HIGHEST ACCUMULATION NUMBERS WL STAY TO OUR SOUTH. HOWEVER...DO ANTICIPATE LIGHT ACCUMULATIONS (< 1") ALONG OUR SRN TIER OF COUNTIES BY DAYBREAK. WE WL ALSO HAVE TO WATCH SFC WINDS AS ANY SLIGHT VEERING TO THE NE COULD ADD TO ACCUMULATIONS OVER MANITOWOC COUNTY. LIGHT SNOW WL CONT OVER E-CNTRL WI THRU AT LEAST SAT MORNING AS THE SFC LOW LIFTS NE FROM THE MID-MS VALLEY TOWARD THE ERN GREAT LAKES AND MID-LEVEL FRONTOGENETICAL FORCING BEGINS TO SHIFT FROM SE WI INTO LWR MI. AN ADDITIONAL INCH OR TWO OF ACCUMULATION IS POSSIBLE OVER E-CNTRL WI...THUS PLAN ON ISSUING A WINTER WEATHER ADVY FOR WINNEBAGO...CALUMET AND MANITOWOC COUNTIES FROM 03Z-21Z SAT (PRIMARILY FOR SRN SECTIONS OF THESE COUNTIES). TRAILING THIS SYSTEM IS A SHRTWV TROF THAT IS FCST TO SWEEP INTO THE WRN GREAT LAKES ON SAT. WHILE THE BULK OF THE SYNOPTIC MOISTURE TO BE TIED UP WITH THE INITIAL STORM...WINDS ARE EXPECTED TO TURN NW AND INTRODUCE LK EFFECT SNOW SHWRS TO N-CNTRL WI. THERE IS A POTENTIAL FOR AN INCH OR TWO OF ACCUMULATION...ESPECIALLY OVER THE SNOWBELT REGION OF VILAS CNTY. MAX TEMPS TO ONLY BE IN THE MID TO UPR 20S N-CNTRL...TO THE MID 30S E-CNTRL WI. ADD IN A NW WIND AT 10 TO 20 MPH AND WIND CHILL VALUES WL ONLY BE IN THE UPR TEENS TO LWR 20S. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 242 PM CST FRI NOV 20 2015 SEVERAL CONCERNS TO DEAL WITH INCLUDE LAKE EFFECT SNOW SHOWERS ACROSS THE NORTH SATURDAY NIGHT INTO SUNDAY MORNING...A CLIPPER SYSTEM SUNDAY NIGHT INTO MONDAY MORNING AND THEN ABOVE NORMAL TEMPERATURES AND UNSETTLED WEATHER FOR THANKSGIVING DAY AND BLACK FRIDAY. PERUSAL OF THE BUFKIT SOUNDING OVER WESTERN LAKE SUPERIOR SATURDAY NIGHT PRETTY IMPRESSIVE SATURDAY NIGHT. ABUNDANT MOISTURE UP TO TEN THOUSAND FEET...EQL LEVELS OF TWELVE TO FIFTEEN THOUSAND FEET AND LAKE TO 850MB TEMPERATURE DIFFERENCES APPROACHING 20C. LOW LEVEL WINDS ARE NOT AS FAVORABLE...BUT CLOSE ENOUGH TO WARRANT INCREASING SNOWFALL TOTALS FROM PREVIOUS FORECAST. CONTEMPLATED LAKE EFFECT SNOW WATCH THINKING THE SNOW BELT REGION OF VILAS COUNTY COULD SEE OVER 6 INCHES IN A FEW SPOTS IF BANDS SET UP. PER COORDINATION WITH DULUTH AND MARQUETTE...WILL HOLD OFF FOR NOW AND MIDNIGHT SHIFT MAY GO WITH AN ADVISORY. A CLIPPER SYSTEM WILL MOVE ACROSS THE REGION SUNDAY NIGHT...BRINGING A CHANCE OF LIGHT SNOW ACROSS THE SOUTH AND LIGHT SNOW LIKELY ACROSS THE NORTH. AN INCH OR TWO IS EXPECTED ACROSS THE NORTH WITH LIGHTER AMOUNTS TO THE SOUTH. ATTENTION THEN TURNS TO WEDNESDAY THROUGH FRIDAY WITH AN UNSETTLED PERIOD EXPECTED. PRECIPITATION SHOULD BE MAINLY RAIN ACROSS CENTRAL AND NORTHEAST WISCONSIN...WITH MORE OF A MIX OF RAIN AND SNOW ACROSS NORTH-CENTRAL WISCONSIN. LATEST ECMWF HAS PUSHED THE FRONT FURTHER SOUTH ON FRIDAY WHERE THE NORTH MAY BE DRY. PLENTY OF TIME TO WORK OUT THE DETAILS. BELOW NORMAL TEMPERATURES THIS WEEKEND SHOULD RETURN TO OR ABOVE NORMAL BY THE MIDDLE OF NEXT WEEK. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 517 PM CST FRI NOV 20 2015 VFR CIGS EXPECTED OVER MOST AREAS TONIGHT. THE ONLY EXCEPTION WOULD BE FOR A WEST TO EAST MVFR OR LOWER END VFR CIG DEVELOPING SOUTH OF HIGHWAY 29 TONIGHT AS A STORM SYSTEM TRACKS OVER NORTHERN ILLINOIS. CONDITIONS WILL DETERIORATE FURTHER SOUTH OVER SOUTHERN WISCONSIN. AS THIS SYSTEM DEPARTS SATURDAY MORNING CONDITIONS EXPECTED TO IMPROVE. HOWEVER PATCHY MVFR CIGS OVER NORTHERN WISCONSIN LATE TONIGHT MAY BECOME MORE WIDESPREAD ON SATURDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 3 PM CST SATURDAY FOR WIZ048>050. && $$ UPDATE.........TDH SHORT TERM.....KALLAS LONG TERM......ECKBERG AVIATION.......TDH
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
250 AM CST MON NOV 23 2015 ...Updated Short and Long Term Discussion... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 248 AM CST MON NOV 23 2015 A northwesterly flow across the Central Rockies will become more westerly during the day. This improving westerly flow will result in a developing trough of low pressure along the lee of the Rockies and some warming in the 950mb to 850mb level. Based on the weak net 24 hour warming trend in the 950mb to 850mb level along with the mixing potential and 00z Tuesday temperatures at this height the highs today are expected to 3-5F warmer than yesterday. Tonight the surface winds will be a little stronger than the past few nights. This combined with increasing low level moisture will tend towards staying close to the latest MET/MAV guidance. .LONG TERM...(Tuesday THROUGH Sunday) ISSUED AT 248 AM CST MON NOV 23 2015 Models remain in good agreement with an upper level storm system moving from the coast of British Columbia into the western United States during the first half of the work week. This will result in the westerly flow across the Central Rockies early in the week backing to the Southwest by early Wednesday. Subtle upper waves embedded in this developing southwesterly flow still evident based on 500mb to 400mb potential vorticity. One of which will be crossing western Kansas on Wednesday and then a stronger wave on Thursday. A cold front moving south across the Northern Plains on Tuesday will extend from eastern Colorado into north central Kansas by early Wednesday. Ahead of this surface boundary a southerly flow will continue to draw more humid air northward into central and portions of western Kansas. Early morning stratus and fog appears possible south of this front based on model soundings. At this time the depth of the low level moisture does not appear deep enough to support drizzle but later shifts may wish to reevaluate this. By Wednesday evening warm air advection will begin to improve across western Kansas. Given this lift along increasing moisture will keep the chance for rain showers and even a few thunderstorms developing Wednesday night, especially east of highway 283. Chance for precipitation will continue on Thursday with the precipitation type being mainly in the form of liquid early in the the day as the cold front moves across southwest Kansas. During the afternoon the colder air moving into western Kansas behind the cold front will cool that atmosphere enough for the rain to change over to snow from northwest to southeast. BUFR soundings even suggest there may be a brief period of freezing rain or sleet before the change over to snow. Given how far out this event is will keep precipitation type simple at this time. On Thursday night the ongoing precipitation will continue early and then begin to taper off from north to south as a 700mb baroclinic zone moves across western Kansas. At this time it appears that the prevailing precipitation type will be snow with the possible exception of portions of south central Kansas. Upper level jet dynamics shift north and northeast early and isentropic downglide observed in the I285 to I295 level by 06z Friday. Frontogenesis also not that strong near the 700mb baroclinic zone. The better moisture and lift appears to be focused above the 700mb level so can not rule out some light snow but accumulations should be light. Possible exception will be near the OK border, especially in far southwest Kansas, where up to an inch may not be completely out of the question. On Friday any lingering light snow will end, however Friday still appears to be cloudy and cold as a surface ridge axis begins to build into western Kansas. Based on 950mb and 850mb temperatures at 18z Friday and 00z Saturday the previous forecast with highs only in the 30s still look on track. On Friday night and Saturday moisture and isentropic lift begins to improve across western Kansas in the i285 to i300 levels as the cold dome of high pressure begins to build into western Kansas and the next upper level wave begins to approach the area from the southwest. Over parts of western Kansas a southeast upslope flow is also evident west of the surface ridge axis. Given moisture return and lift late Friday night into Saturday there will be improving chances for snow across all of western Kansas early this weekend. This chance for precipitation will continue through early Sunday. Some snow accumulations will be possible from this weekend event, however at how much snow and where is still unclear. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Monday NIGHT) ISSUED AT 1145 PM CST SUN NOV 22 2015 VFR conditions are expected overnight and Monday based on BUFR soundings moisture profiles along with the latest RUC and HRRR. The winds will be west to southwest at less than 10 knots. Southwesterly winds on Monday are expected to increase to around 15 knots by the early afternoon as a the weak surface trough axis, located across eastern Colorado, remains nearly stationary and deepens. && .PRELIMINARY POINT TEMPS/POPS... DDC 62 34 60 38 / 0 0 0 0 GCK 63 28 59 31 / 0 0 0 0 EHA 63 31 66 37 / 0 0 0 0 LBL 64 32 63 35 / 0 0 0 0 HYS 62 33 57 37 / 0 0 0 0 P28 64 35 61 47 / 0 0 0 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1147 PM CST SUN NOV 22 2015 ...Updated Synopsis and Aviation discussions... .SYNOPSIS... ISSUED AT 1145 PM CST SUN NOV 22 2015 At 00z Monday a 500mb trough extended from the Upper Great Lakes to the Tennessee Valley. A 500mb ridge axis was located along the western United states. Over the Central United States a northwest flow was evident at the 700mb and 500mb level. Across Kansas and Nebraska earlier this evening 850mb temperatures varied from +3 at Topeka to +8C at Dodge City and North Platte. && .SHORT TERM...(THIS EVENING THROUGH Monday) ISSUED AT 316 PM CST SUN NOV 22 2015 Northwest flow aloft will persist through the next couple of days. Weak westerly surface flow will give way to south winds once again on Monday as the surface trough develops over eastern Colorado. As more broad zonal flow develops by Monday night, an initial lead westerly shortwave will be approaching the region. Models suggest this will be mainly a dry/ non-precipitation events, with probably an increase in cloud cover heading into the Tuesday period. Continually but slightly increasing high temperatures are likely in the meantime as the boundary layer temperatures rise sue to adiabatically warmed air from the higher terrain. The snow over extreme western Hamilton county will likely be eliminated, and highs could reach the low 60s area wide on Monday. The latest ECMWF model temperatures have appear to do the best in the medium range and were generally followed. .LONG TERM...(Monday NIGHT THROUGH Sunday) ISSUED AT 316 PM CST SUN NOV 22 2015 The more amplified wave will be on the heels right around the Thanksgiving travel period. Initially higher surface winds will likely mean slower warming Tuesday and perhaps slightly cooler highs. An increase in cirrus clouds should occur by late Tuesday with the aforementioned shortwave before stronger surface pressure falls develop ahead of the strong cold front all the models show by Thanksgiving day. The main problem will be precipitation, how much and what type. Rain and thunderstorms are possible in the prefrontal environment as the models indicate modest moisture transport, but it is possible most of this will be well to the east in eastern Kansas as well. It is possible our far western Kansas counties will be on the low end for precipitation probabilities, but fare better after the frontal passage for ra/sn. The models indicate another system on its heels by around saturday, and precipitation probabilities remain in the forecast through the rest of the extended. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Monday NIGHT) ISSUED AT 1145 PM CST SUN NOV 22 2015 VFR conditions are expected overnight and Monday based on BUFR soundings moisture profiles along with the latest RUC and HRRR. The winds will be west to southwest at less than 10 knots. Southwesterly winds on Monday are expected to increase to around 15 knots by the early afternoon as a the weak surface trough axis, located across eastern Colorado, remains nearly stationary and deepens. && .PRELIMINARY POINT TEMPS/POPS... DDC 29 61 33 59 / 0 0 0 0 GCK 26 59 28 56 / 0 0 0 0 EHA 26 60 33 62 / 0 0 0 0 LBL 27 61 32 59 / 0 0 0 0 HYS 28 60 31 55 / 0 0 0 0 P28 30 61 34 59 / 0 0 0 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ SYNOPSIS...Burgert SHORT TERM...Russell LONG TERM...Russell AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1246 AM EST MON NOV 23 2015 .SYNOPSIS... LOW PRESSURE WILL DEVELOP ALONG A STATIONARY FRONT EAST OF THE REGION TONIGHT AND MOVE NORTHEAST MONDAY TOWARD NOVA SCOTIA. HIGH PRESSURE WILL BUILD TOWARD THE REGION MON NIGHT INTO TUE. && .NEAR TERM /THROUGH TODAY/... UPDATE 1240 AM: HAVE ADJUSTED TEMPERATURE... DEWPOINT AND WIND. NO OTHER CHANGES. SFC LOW CURRENTLY SITTING OFF OF THE VIRGINIA CAPES AND RIDING UP ALONG FRONTAL BOUNDARY JUST OFFSHORE. FAIRLY TIGHT GRADIENT EXISTS BTWN PCPN AND NO PCPN AS EXPECTED WITH HUL HVG RAIN AND PQI NOTHING IN THE WAY OF PCPN. RADAR POPUP SKEW T IS SHOWING HUL ISOTHERMAL FROM ABOUT 900MB UP WITH BLYR ABV ZERO ALL THE WAY BACK TO ALLAGASH. THIS AGREES WELL WITH LATEST HRRR DATA THUS HV ADJUSTED WX GRIDS BASED ON HRRR FCST DATA THRU THE MRNG. EXPECT THAT PCPN WL BE HIT AND MISS IN NATURE FROM ABOUT PQI NORTHWARD BUT IF IT CAN GET THIS AFTN NORTH IT SHOULD NOT BEGIN TO MIX WITH SNOW UNTIL CLOSE TO 03Z. PCPN SHUD GRADUALLY SPREAD NORTH AFT ABOUT 05Z AS LOW TRACKS CLOSER TO GULF OF MAINE IN COMBINATION WITH RFQ OF H3 SPEED MAX GETTING EVER CLOSER TO CWA. THIS WL BRING THE BEST CHC FOR ACCUMULATING SNOW FOR NORTHERN AREAS BFR DAYBREAK. AT THIS TIME IT APPEARS THAT QPF AMNTS WL BE LIGHT FOR NRN ZONES AND WL BE HARD-PRESSED TO SEE MORE THAN AN INCH OF SNOW AND SLEET FOR AREAS NORTH OF A MILLINOCKET TO HOULTON LINE. THUS WL CONTINUE WITH MENTION OF AMNTS UP TO AN INCH BY MRNG. FURTHER TO THE SOUTH HV LOWERED STORM TOTAL SNOW AMNTS BY ARND AN INCH AS IT APPEARS THAT CLD AIR WL TAKE LONGER TO WRAP IN BHND LOW ESPECIALLY ALONG THE COAST. HWVR, WL CONT WITH WINTER WX ADVISORY AS STILL EXPECTING WIDESPREAD 1-4 INCHES ON TOP OF SLEET THAT FALLS. ALL THIS WL FALL ON ALREADY WET ROADWAYS WHICH WL QUICKLY ICE OVER AS TEMPS FALL DRG THE DAY TOMORROW. HIGHEST SNOW TOTALS LOOK TO OCCUR ACRS NRN WASHINGTON CNTY AS WELL AS PARTS OF SE AROOSTOOK CNTY. PREV DISCUSSION BLO... LONGER RANGE MODELS HAVE COME INTO BETTER CONSENSUS FOR THIS AFTN`S FCST UPDATE REGARDING THE COASTAL LOW EVENT MOVG NE FROM OFF THE MID ATLC STATES TNGT TOWARD THE CNTRL NOVA SCOTIA MON AFTN. THE 12Z DTMNSTC ECMWF BACKED OFF FROM BEING FURTHER N LIKE THE PRIOR 00Z ECMWF RUN...BOTH WITH THE PSN OF THE SFC LOW AND HEAVIER QPF FURTHER N INTO CNTRL AND NRN PTNS OF THE FA. THE FURTHER SE TRACK OF THE 12Z GFS AND CANGEM MODELS SEEMS TO BE INITIALLY VERIFYING BASED ON THE TRAJECTORIES OF THE WRN EDGE OF RADAR REF MOVG INTO THE MID COAST AND DOWNEAST PTNS OF ME LATE THIS AFTN. BASED ON THE CURRENT FCST OF THE LOW TRACK...MILD AIR CURRENTLY OVR THE FA WILL BE REPLACED BY SIG COLDER AIR MOVG E FROM QB AS THE LOW HELPS ADVECT IT SE INTO OUR FA LATER TNGT INTO MON MORN. TEMPS WILL FALL FAIRLY QUICKLY...FIRST ACROSS THE NW HLF LATER THIS EVE THEN SPREADING SE THRU THE REST OF THE FA LATE TNGT INTO MON MORN...RESULTING IN PRECIP CHGNG FROM RN TO SN NW TO SE ACROSS THE FA DURG THIS TM...PERHAPS ACCOMPANIED BY A BRIE PD OF SLEET BASED ON SREF PRECIP TYPES AND FCST SOUNDINGS. THE TRICKY PART OF THIS FCST WILL BE OVR E CNTRL AND DOWNEAST PTNS OF THE FA WHERE SIG PRECIP RATES MAY STILL BE GOING ON WHEN TEMPS APCH OR FALL BELOW FZG...MEANING LCTNS CHGNG TO SNOW LATEST TNGT N OF THE IMMEDIATE DOWNEAST COAST COULD RECEIVE THE MOST SN DUE TO GREATER REMAINING QPF LEFT WITH THIS EVENT. SPEAKING OF QPF... STORM TOTAL QPF WILL RANGE FROM NEAR ZERO OVR THE FAR NW TO NEARLY 2.00 INCHES OVR THE EXTREME SE. FOR NOW...OUR OFFICIAL MAX SNFL TOTALS ARE 3 TO 5 INCHES OVR NRN AND CNTRL WASHINGTON COUNTIES WITH LESSER AMOUNTS ELSEWHERE...BUT GIVEN UNCERTAINTIES OF CHGOVR TM AND POTENTIAL INTENSITY OF SNFL AFT THE CHGOVR...CONFIDENCE WITH MAX AMOUNTS OVR THIS PTN OF THE FA IS NOT HIGH WITH SIG MORE OR LESS POSSIBLE. LATER SHIFTS WILL NEED TO MONITOR OBSVD AND MODEL TRENDS WITH THIS EVENT. IN ANY EVENT...SN WILL TAPER TO SCT SN SHWRS N AND RN/SN SHWRS CNTRL AND DOWNEAST MON AFTN AND THEN END BY LATE IN THE DAY. BOTH LOWS TNGT AND HI TEMPS MON WILL BE COLDER...SPCLY OVR CNTRL AND DOWNEAST PTNS OF THE FA. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... THE SHORT TERM WILL FEATURE FAIR WEATHER UNDER A BUILDING RIDGE, THOUGH AT LEAST TUE WILL BE A BIT COOLER THAN NORMAL. AT THE BEGINNING OF THE SHORT TERM, THE BULK OF THE PRECIP IS EXPECTED TO HAVE DEPARTED TO THE EAST. HOWEVER, WITH THE BASE OF THE UPR TROF SWINGING OVER THE AREA MON NIGHT, CAN`T RULE OUT SOME LINGERING CLOUDS AND A FEW LIGHT SN SHWRS IN THE FAR NRN CWA, AS WAS REFLECTED IN A FEW MODELS. BEYOND THAT, HIGH PRESSURE AND RIDGING TUE THRU WED WILL BRING PARTLY TO MOSTLY SUNNY SKIES TO THE STATE. COLD AIR DRAWN IN BEHIND THE LOW MON NIGHT AND GOOD RADIATIONAL COOLING WILL SET THE STAGE FOR SOME OF THE COLDEST TEMPS IN THE CWA THUS FAR THIS COLD SEASON MON AND TUE NIGHTS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE WILL GRADUALLY SLIDE OFF THE EAST COAST THURSDAY, KEEPING CONDITIONS DRY FOR THANKSGIVING DAY. THIS WILL ALSO PLACE THE REGION UNDER SOUTHWEST FLOW ON THE BACKSIDE OF THE HIGH, ALLOWING TEMPERATURES TO WARM INTO THE MID AND UPPER 40S. HOWEVER, LOW PRESSURE MOVING BY TO OUR NORTH WILL SLOWLY DRAG A COLD FRONT EASTWARD ACROSS THE EASTERN US/CANADA THURSDAY NIGHT THROUGH FRIDAY. THERE`S SOME DISAGREEMENT AMONGST THE LONGER-RANGE MODELS ON THE EXACT TIMING OF THIS FRONT AND ITS PRECIPITATION, BUT THE HIGHEST THREAT FOR FRONTAL PASSAGE LOOKS TO OCCUR SOMETIME LATE FRIDAY THROUGH SATURDAY. IF THE FRONT HOLDS OFF UNTIL FRIDAY NIGHT, EXPECT WE`LL SEE VERY MILD TEMPERATURES FOR THE DAY AFTER THANKSGIVING AS HIGHS TOP OUT IN THE UPPER 40S TO LOWER 50S. HOWEVER, IF THE FRONT MOVES THROUGH A LITTLE FASTER (SIMILAR TO THE GFS SOLUTION), NORTHERN MAINE MAY HAVE A COOLER AND WETTER FRIDAY THAN IS CURRENTLY IN THE FORECAST. REGARDLESS, EXPECT MUCH COLDER AIR WILL MOVE IN BEHIND THE FRONT. SUNDAY LOOKS TO BE THE COLDEST DAY OF THE WEEKEND AT THE MOMENT, WITH HIGHS ONLY IN THE 20S IN THE NORTH, AND LOWS IN THE TEENS. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... NEAR TERM: IFR EXPECTED NEXT 24 HOURS AT MOST TERMINALS IN RAIN/SNOW. EXCEPTION WILL BE FVE WHERE SITE WILL MOST LIKELY BE AFFECTED BY IFR CIGS WITH PCPN REMAINING TO THE SOUTH. STILL SOME QUESTION AS TO HOW MUCH CAR AND PQI WILL SEE WITH REGARD TO PTYPE AS THEY WILL BE ON NORTHERN EDGE OF PCPN SHIELD. HUL WILL SEE RA/SN MIX AROUND 03Z THEN OVER TO ALL SNOW AFTER 06Z. BGR CAN BE EXPECTED TO BE RA/SN AFTER 04Z THEN SWITCHING TO SNOW BY 08Z. BHB WILL BE LATEST TO SEE CHANGEOVER TO RA/SN BY 09Z AND ALL SNOW AROUND 10Z. BY 18Z MON BHB, BGR AND HUL WILL SEE IMPROVEMENT TO VFR CIGS WITH FVE, CAR AND PQI VFR BY 15Z. NW WINDS WILL BE GUSTY DURING THE DAY AT 15G25KTS. SHORT TERM: ASIDE FROM THE CHC FOR SOME MVFR CIGS AND ISO SN SHWRS FOR KFVE BEFORE 09ZTUE, ALL TERMINALS ARE EXPECTED TO HAVE VFR CIGS AND VIS THROUGH WED EVENING. VFR CONDITIONS WILL THEN CONTINUE THROUGH FRIDAY, THOUGH MVFR CEILINGS WILL BE POSSIBLE AT THE NORTHERN TERMINALS FRIDAY AFTERNOON AS A COLD FRONT APPROACHES FROM THE NORTH. && .MARINE... NEAR TERM: E TO NE WINDS WILL INCREASE TO SCA CRITERIA FOR THE INNER BAY/HARBOR MZ THIS EVE AND GALES (IN GUSTS) OVR THE OUTER MZS LATE TNGT...BACKING TO THE N AS THEY CONTINUE INTO MON. GALES OVR THE OUTER MZS WILL NEED TO BE TRANSITIONED TO AN SCA LATER MON AFTN. KEPT CLOSE TO WW3 WV GUIDANCE FOR FCST WV HTS. SHORT TERM: SCA WIND GUSTS AND SEAS LKLY ONGOING OFFSHORE AT THE START OF THE SHORT TERM. WILL CONTINUE TUE AM BEFORE GRADUALLY DIMINISHING TUE PM AS HIGH PRES BUILDS INTO THE AREA. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR MEZ006-011-015. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MEZ016-017-029-030-032. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ052. SMALL CRAFT ADVISORY UNTIL 3 AM EST EARLY THIS MORNING FOR ANZ050-051. GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR ANZ050-051. && $$ NEAR TERM...MIGNONE
AREA FORECAST DISCUSSION
NWS GRAY ME
1239 AM EST MON NOV 23 2015 .SYNOPSIS... LOW PRESSURE WILL MOVE NORTHEASTWARD THROUGH THE GULF OF MAINE TONIGHT ALLOWING FOR SOME RAIN AND SNOW ON THE COASTAL PLAIN. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION MONDAY MORNING WHILE LOW PRESSURE TRACKS TO OUR EAST. THE HIGH WILL SHIFT OFFSHORE ON WEDNESDAY AND A BROAD UPPER LEVEL RIDGE BUILDS OVER NEW ENGLAND. THIS WILL BRING ABOVE AVERAGE TEMPERATURES THROUGH THE END OF THE WORK WEEK. HIGH PRESSURE WILL HOLD OFFSHORE THROUGH FRIDAY AND THE NEXT CHANCE FOR RAIN WILL COME OVER THE WEEKEND POSSIBLY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... UPDATE... COLD AIR CONTINUES TO ADVECT SOUTH AND EASTWARD OVERNIGHT WHILE HEIGHTS LOWER ALOFT. THIS WILL CONTINUE TO ALLOW THE RA TO CHANGE TO SN OVERNIGHT. MODERATE SNOW AS FAR SOUTH AS THE GYX OFFICE AS OF MIDNIGHT ACCORDING TO SOCIAL MEDIA AND TELCON REPORTS. LATEST HRRR RUN CONTINUES TO SHOW A NICE BAND SETTING UP FROM COASTAL CUMBERLAND COUNTY AND POINTS NORTHEASTWARD THROUGH THE I95 CORRIDOR AND POINTS TO THE EAST AT 09Z. BEST FOCUS SHIFTS EAST INTO THE KNOW/WALDO COUNTY AREAS BY 12Z. SOME OF THE FIRST ACCUMULATING SNOWS OF THE SEASON WILL BE OCCURRING DURING THAT TIME PERIOD...LEADING TO HAZARDOUS TRAVEL CONDITIONS. PREV DISC... 11 PM UPDATE: RADAR SHOWS RAIN SHIELD MOVING INTO COASTAL AND MIDCOAST AREAS AS FORECAST. QUICK PEEK AT LATEST MODELS SHOW GOOD CONTINUITY FROM PRIOR RUN. COLD AIR WORKING IN INTO THE LOWER LEVELS OVER THE NEXT SEVERAL HOURS WILL GRADUALLY CHANGE PTYPE TO SNOW. ONLY MINOR TWEAKS TO TEMPS OTRW NO CHANGES NEEDED ATTM. 630 PM UPDATE: UPDATED TEMPS BASED ON LATEST OBS DATA. ALSO ADDED SOME AREAS OF FOG FOR COASTAL AND THE ADJACENT AREAS OF ME/NH FOR NEXT FEW HOURS BEFORE WINDS WINDS AND INCREASING MIXING IN THOSE AREAS INCREASE. PREVIOUS DISCUSSION: CHALLENGING FORECAST THIS SUNDAY AFTERNOON AS WE/LL BE DEALING WITH A TIGHT PRECIPITATION GRADIENT OVERNIGHT. A SOUTHERN STREAM SHORT WAVE TROUGH CURRENTLY EJECTING OFF THE CAROLINA COAST THIS EVENING WILL MOVE NORTHEAST OVERNIGHT. THIS TROUGH AND ASSOCIATED SFC LOW PRESSURE WILL COME CLOSE ENOUGH TO THE NEW ENGLAND COAST TO ALLOW FOR THE SHIELD OF PRECIPITATION TO MOVE INTO THE COASTAL PLAIN OF MAINE AND NEW HAMPSHIRE. HOWEVER...THE QUESTION IS HOW FAR WEST...HOW MUCH QPF...AND HOW MUCH WILL FALL AS SNOW? THE 12Z MODELS AND ENSEMBLES HAVE COME MORE OR LESS INTO GENERAL AGREEMENT WITH THE WESTERN EXTENT OF THE STRONG FORCING FOR ASCENT. HOWEVER...SHARP BACK EDGES ARE ALWAYS TRICKY SINCE 5 TO 10 MILES COULD MEAN THE DIFFERENCE BETWEEN NO PRECIPITATION AND UP TO A HALF INCH LIQUID OR LIQUID EQUIVALENT. USED A CONSENSUS APPROACH FOR THE OVERNIGHT HOURS...AND GAVE THE LATEST MESOSCALE MODELS /HRRR AND RAP/ A LITTLE MORE CREDENCE IN THE BLEND. THIS WAS ALSO THE CASE WITH TIMING OF POPS AS WELL. AT THE SAME TIME...THE COLUMN AS A WHOLE WILL GRADUALLY GET COLDER OVERNIGHT...AND THIS INCLUDES A CONTRIBUTION FROM DYNAMIC COOLING THAT SHOULD OCCUR ONCE THE HEAVIER PRECIPITATION GETS GOING. SO BLENDING THE ABOVE IDEAS WITH TEMPERATURE AND POP TRENDS ALONG WITH A CONSENSUS-BASED QPF FORECAST...IT LOOKS AS THOUGH SOME ACCUMULATING SNOW IS IN THE CARDS TONIGHT FOR THE COASTAL PLAIN AS WELL AS PORTIONS OF CENTRAL MAINE. RAIN THIS EVENING SHOULD GRADUALLY FLIP OVER TO WET SNOW AFTER MIDNIGHT FROM WEST TO EAST AS A COLUMN COOLS. THEREAFTER...IT DEPENDS ON HOW HARD IT IS PRECIPITATING THAT WILL DETERMINE HOW MUCH SNOW STICKS. USING OUR CURRENT IDEAS...WE ARE FORECASTING UP TO AN INCH OF SNOW ON THE MAINE COASTAL PLAIN...WITH 1 TO 3 INCHES ON THE MID COAST NORTHWARD INTO PARTS OF CENTRAL MAINE. HIGHER ELEVATIONS NEAR THE MID COAST SUCH AS THE CAMDEN HILLS NORTHWARD TO THE HILLY SPOTS IN WALDO COUNTY NEAR ROUTES 202 AND 139 COULD ALSO EXPERIENCE HIGHER AMOUNTS. PERHAPS UP TO 4 INCHES DEPENDING HOW FAST THE PRECIP CHANGES OVER AND HOW HARD IT FALLS. AT THIS TIME...SNOW AMOUNTS SHOULD BE MINIMAL ENOUGH TO AVOID WIDESPREAD POWER OUTAGE PROBLEMS. HOWEVER...ISOLATED OUTAGES WILL BE POSSIBLE GIVEN THE EXPECTED HEAVY AND WET NATURE TO THE SNOW AFTER THE CHANGEOVER COMBINED WITH INCREASING NORTHERLY WINDS. OTHERWISE...FURTHER SOUTH DOWN I-95 INTO AUGUSTA...LEWISTON...GRAY...AND PORTLAND...UP TO AN INCH WILL BE POSSIBLE /PERHAPS A LITTLE BIT MORE IN AUGUSTA/WATERVILLE CORRIDOR/. TEMPERATURES WILL FALL TO NEAR FREEZING IN THESE AREAS TOWARD MORNING SO IT/S POSSIBLE ANY WET SNOW AND STANDING WATER COULD FREEZE AND THIS MAY ALLOW FOR SOME SLIPPERY SPOTS FOR THE AM COMMUTE. IF THE IMPACTS LOOK TO BE A LITTLE MORE SUBSTANTIAL LATER ON...AN ADVISORY MAY BE ISSUE FURTHER SOUTH. FOR NOW...WE HAVE A WINTER WEATHER ADVISORY FOR JUST WALDO AND KNOX COUNTY WHERE THE POTENTIAL FOR ACCUMULATING SNOW IS GREATEST. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... ANY SNOW WILL MOVE OUT EARLY MONDAY MORNING...WITH SUNNY SKIES QUICKLY MOVING IN. OVERALL...COLD TEMPERATURES AND BLUSTERY WINDS WILL BE THE RULE MONDAY. HIGH PRESSURE MOVES IN MONDAY NIGHT ALLOW FOR A COLD AND CLEAR NIGHT. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... THE MODELS ARE IN GENERAL AGREEMENT ON THE LONG WAVE PATTERN THROUGH LATE NEXT WEEK. THE UPPER TROUGH ACROSS THE REGION AT THE START OF THE PERIOD WILL LIFT OUT INTO THE MARITIMES BY WEDNESDAY...REPLACED BY A BROAD RIDGE AND WEST-SOUTHWEST FLOW ALOFT...IN RESPONSE TO DIGGING PACIFIC SHORTWAVE ENERGY CARVING OUT A DEEP TROUGH OVER THE WESTERN CONUS. BY FRIDAY...SIGNIFICANT DIFFERENCES EMERGE IN NUMERICALS WITH GFS MOST PROGRESSIVE WITH HANDLING OF WESTERN TROUGH...WITH SLOWER ECMWF/CMC-GLOBAL SCENARIO REMAINING THE PREFERRED SOLUTION FOR NOW. IN THE DAILIES...A FEW CLOUDS TUESDAY AS THE UPPER TROUGH SWINGS ACROSS THE AREA. RISING HEIGHTS WITH HIGH PRESSURE AND DRY AIR BRINGS MODERATING TEMPERATURES FOR WEDNESDAY AND THURSDAY. THE PREFERRED AND SLOWER ECMWF/CMC-GLOBAL SOLUTIONS KEEP THE RIDGE ACROSS THE AREA AND THE APPROACHING FRONTAL SYSTEM WELL TO OUR WEST ON FRIDAY. THE COLD FRONT SHOULD CROSS THE AREA ON SATURDAY...WITH SHARPLY COLDER TEMPERATURES AND SOME UPSLOPE SNOW SHOWERS IN ITS WAKE TO ROUND OUT NEXT WEEKEND. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... SHORT TERM...MVFR TO IFR CONDITIONS ARE PROBABLE TONIGHT ON THE COASTAL PLAIN WHERE RAIN CHANGING TO SNOW IS LIKELY. VFR CONDITIONS RESUME MONDAY MORNING AND CONTINUE THROUGH MONDAY NIGHT. GUSTY NORTHWESTERLY WINDS TO 25 KT WILL BE LIKELY LATE TONIGHT AND MONDAY. LONG TERM... NO SIGNIFICANT OPERATIONAL IMPACTS DUE TO WEATHER EXPECTED. && .MARINE... SHORT TERM...SMALL CRAFT ADVISORIES HAVE BEEN HOISTED FOR TONIGHT THROUGH MONDAY. NOT OUT OF THE QUESTION THESE WILL NEED TO BE UPGRADED TO GALES FOR A TIME LATE TONIGHT INTO MONDAY. WINDS AND SEAS DIMINISH MONDAY NIGHT. LONG TERM... THU - FRI...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE WITH GUSTS TO NEAR GALE OUTSIDE THE BAYS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY UNTIL 8 AM EST THIS MORNING FOR MEZ022- 027-028. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EST TUESDAY FOR ANZ150>154. && $$ JC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
450 AM EST MON NOV 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM EST MON NOV 23 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF EXTENDING S THRU THE GREAT LAKES REGION. SHEARED OUT SHORTWAVE/LEFT EXIT OF 120+KT UPPER JET EXTENDING FROM SASKATCHEWAN INTO THE UPPER MISSISSIPPI VALLEY HAS GENERATED SOME AREAS OF -SN INTO WRN UPPER MI OVERNIGHT. MODELS OVER THE LAST DAY OF RUNS CORRECTLY TRENDED LIGHTER WITH THIS PCPN AS SNOW THAT HAS OCCURRED HAS BEEN VERY LIGHT WITH NOT MUCH MORE THAN A DUSTING OF ACCUMULATION WHERE SNOW HAS FALLEN PER WEBCAMS. TO THE E...JUST AS SOME HIGH RES MODELS WERE INDICATING 24 HRS AGO...THE REGIONAL CANADIAN IN PARTICULAR...A BURST OF HVY SNOW MOVED N OFF NRN LAKE MI INTO PARTS OF THE ERN U.P. OVER THE LAST SEVERAL HRS. IT APPEARS THE EXTREME SE CORNER OF LUCE COUNTY PROBABLY SAW A VERY BRIEF PERIOD OF MDT TO HVY SNOW AROUND 06Z. THAT AREA OF MDT/HVY SNOW HAS SHIFTED E INTO THE STRAITS VCNTY SINCE THEN. THERE IS STILL SOME CONCERN FOR LAKE ENHANCED SNOW OFF NRN LAKE MI TO SHIFT/REFORM BACK TO THE W TODAY. ON THE HIGH EXTREME IS THE REGIONAL CANADIAN WHICH GENERATES 0.3 INCHES OF QPF IN THE FAR SE CORNER OF LUCE COUNTY BTWN 15Z AND 00Z. SINCE THE MAJORITY OF AVBL HIGH RES GUIDANCE...INCLUDING THE HIGH RES CANADIAN...KEEPS THE BULK OF REDEVELOPING LAKE ENHANCED SNOW JUST E OF LUCE COUNTY...WILL KEEP SNOW AMOUNTS UNDER ADVY CRITERIA WITH PERHAPS 1.5-2 INCHES TO THE SE OF KERY. ELSEWHERE....PATCHY -SN MOVING ACROSS WRN UPPER MI ATTM SHOULD DISSIPATE OVER THE NEXT SEVERAL HRS AS IT SHIFTS E AND HAS TO OVERCOME INITIAL DRY LOWER LEVEL AIR. THEN...A SFC LOW PRES TROF WILL SWING INTO WRN UPPER MI LATE MORNING/AFTN...BRINGING A WIND SHIFT TO THE W TO NW. EXPECT -SHSN TO ACCOMPANY THE TROF AS OVERLAKE INSTABILITY WITH 850MB TEMPS AROUND -7C WILL BE MORE THAN SUFFICIENT TO GENERATE -SHSN ALONG THE TROF/CONVERGENCE ZONE AS IT CROSSES WRN LAKE SUPERIOR. THIS WILL THEN TRANSITION TO SCT LAKE EFFECT -SHSN INTO TONIGHT FOR AREAS FAVORED BY NW WINDS AS 850MB TEMPS DROP A DEGREE OR TWO C. INITIALLY...INVERSION IS UP AROUND 7KFT THIS EVENING...BUT FALLS TO AROUND 4KFT W OVERNIGHT AND TO AROUND 5KFT E LATE. DESPITE THE DECENTLY HIGH INVERSION HEIGHTS...SNOW ACCUMULATIONS WILL BE LIMITED DUE TO THE DGZ BEING ABOVE THE CONVECTIVE LAYER. AT THIS POINT...EXPECT ACCUMULATIONS MOSTLY UNDER 1 INCH...BUT IF ANY RELATIVELY STATIONARY BANDS SET UP...THERE CERTAINLY COULD BE ISOLATED 2-3 INCH AMOUNTS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 422 AM EST MON NOV 23 2015 ...RAIN CHANGING TO SNOW WED NIGHT INTO THANKSGIVING DAY WITH ACCUMULATING SNOW POSSIBLE INTO THU NIGHT... IN LARGER SCALE...DEEP TROUGH OVER EASTERN CONUS SLIDES TO EASTERN CANADA ON TUE WHILE SPLIT FLOW TROUGHING DEVELOPS WESTERN CANADA TO WESTERN CONUS. 1000-850MB TROUGH FORMING ON TUE OVER ROCKIES AND ADJACENT PLAINS AND LOW-LEVEL HIGH PRESSURE SETTLING TO SOUTHEAST CONUS WILL ALLOW S/SE WINDS AT SFC TO BRING INCREASING MOISTURE OFF THE GULF OF MEXICO TOWARD THE MIDDLE MISSISSIPPI RIVER VALLEY. WILL STAY DRY OVER UPR LAKES ON TUE BUT LATE TUE NIGHT INTO WED MORNING SOUNDINGS SHOW INCREASING MOISTURE BLO H9 INTO UPPER GREAT LAKES. IF THERE IS ANY PRECIP AROUND ON WED MORNING...IT LIKELY WOULD TAKE FORM OF DZ/FZDZ DEPENDING ON SFC TEMPS. BEST CHANCE FOR LIGHT ICING WOULD BE OVER INTERIOR CNTRL CWA FM IRON/DICKINSON INTO BARAGA AND WESTERN MARQUETTE COUNTY. MODELS SOMETIMES ARE TOO OVERDONE ON THIS TYPE OF LOW-LEVEL MOISTENING BUT IN THIS CASE THERE IS DECENT SNOW PACK JUST TO THE SOUTH SO THAT MAY HELP THE EXPANSION OF LOW-LEVEL MOISTURE. LATER ON WEDNESDAY DEEPER MOISTURE AND LARGER SCALE FORCING INCREASE STEADILY AHEAD OF SHORTWAVE TROUGH SLIDING OVER MANTIOBA AND NORTHERN ONTARIO. LOW-LEVEL THETA-E ADVECTION INCREASES BRIEFLY BEFORE BEING SHUNTED TO THE SOUTH AND EAST ON WED NIGHT. SHOULD SEE LIGHT RAIN BECOME MORE WIDESPREAD...BUT WITHOUT MUCH OF STRONG MOISTURE TAP AHEAD OF THE TROUGH WITH THE NORTHERN STREAM SHORTWAVE TROUGH...RAINFALL AMOUNTS SHOULD BE LIGHT. COOLER AIR WITH H85 TEMPS DOWN BLO -2C SLIDES IN AFTER MIDNIGHT WED NIGHT OVER THE WEST AND THAT SHOULD TURN ANY LINGERING RAIN TO SNOW. GFS SOUNDINGS AND H85- H7 RH FIELDS FM THE ECMWF INDICATE MID-LEVEL DRYING MAY LEAD TO CHANCES OF FREEZING DRIZZLE OR DRIZZLE INSTEAD OF SNOW LATE WED NIGHT INTO THANKSGIVING MORNING WITH MOIST LAYER AT TEMPS BLO 0C BUT MUCH WARMER THAN -10C. UPSLOPE FLOW OFF LK SUPERIOR WOULD ALSO AID IN LOW-LEVEL LIFT AND MAYBE LEAD TO GREATER CHANCES OF DRIZZLE FOR WEST AND NCNTRL UPR MICHIGAN. ADDED MENTION OF DZ/FZDZ IN THE GRIDS FOR THESE AREAS. ATTN LATER ON THANKSGIVING TURNS TO WAVE OF LOW PRESSURE THAT RIDES NORTHEAST ALONG THE TROUGH OVER THE UPR GREAT LAKES. 00Z ECMWF TRENDED FARTHER WEST WITH THE WAVE WHILE THE GFS TRENDED FARTHER EAST. IF THE ECMWF IS CORRECT SWATH OF MODERATE PRECIP WOULD LIFT BACK OVER AT LEAST THE SOUTH AND EAST CWA THANKSGIVING AFTN INTO THU NIGHT. SINCE THE INITIAL TROUGH/COLD FRONT IS THROUGH MOST CWA PTYPE WOULD MOSTLY BE SNOW...EXCEPT OVER FAR SCNTRL WHERE WARM AIR LINGERS AS EVEN ECMWF SHOWS H85 TEMPS AT LEAST +1C WHEN HEAVIER QPF IS FORECAST TO MOVE THROUGH. SFC TEMPS STILL MID 30S AS WELL SO NO RISK OF ANY FREEZING PRECIP EITHER. JUST INLAND OVER SOUTH CENTRAL AND OVER MOST OF THE EASTERN CWA /N WINDS LEADING TO OFFSHORE WINDS AT ESC AND ISQ/ COULD SEE SEVERAL INCHES OF WET SNOW WITH THE ECMWF SOLN AS 12 HR QPF BTWN 18Z THU AND 06Z FRI IS AT LEAST 0.5 IF NOT UP TO 0.75 INCH. MEANWHILE...LATEST GFS BARELY IS OVER 0.25 INCHES FOR THAT TIME FRAME. GEM IS MORE LIKE THE ECMWF WITH TOTAL QPF...BUT MUCH WARMER AND WOULD RESULT IN MOSTLY RAIN FOR THOSE AREAS. WPC PREFERRED CONSENSUS OF GFS/ECMWF/GEM. WILL CONTINUE TO MENTION THE RAIN TO SNOW AND SOME ACCUMULATING SNOW IN THE HWO...BUT CANNOT PLAY UP THE SNOW TOO MUCH OR GET TOO SPECIFIC YET GIVEN THE UNCERTAINTIES THAT REMAIN. BEHIND THIS SYSTEM...TURNS COLD ENOUGH FOR LAKE EFFECT SNOW SHOWERS OFF LK SUPERIOR FRI INTO FRI NIGHT. ON FRI...AREAS FAVORED BY N WINDS MAY SEE SOME SNOW FOR A CHANGE...THEN WOULD BE MAINLY NW FLOW AREAS FRI NIGHT. DRY LOW-LEVEL AIRMASS WITH STRONG HIGH BUILDING IN SHOULD LIMIT EXTENT OF LES. BASED ON CURRENT MODEL SOLUTIONS IT IS DOUBTFUL AMOUNTS WOULD REACH ADVY LEVELS FRI-FRI NIGHT. SLIGHT WARMING TREND WITH GENERALLY DRY WEATHER IS EXPECTED FOR NEXT WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1225 AM EST MON NOV 23 2015 A DISTURBANCE MOVING THROUGH THE REGION WILL BRING LIGHT SNOW INTO THE WEST HALF OF UPPER MI. THIS SHOULD GRADUALLY DROP CONDITIONS INTO THE MVFR RANGE LATE IN THE NIGHT. EVEN THOUGH ANY SNOW TODAY WILL BE LIGHT...MVFR CONDITIONS WILL PERSIST AS LOW LEVEL MOISTURE LINGERS ACROSS THE REGION. HOWEVER...WNW WINDS WITH MORE OF A DOWNSLOPE COMPONENT WILL FAVOR VFR CIGS AT KSAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 450 AM EST MON NOV 23 2015 NO GALES ARE EXPECTED ON LAKE SUPERIOR THRU THE END OF THE WEEK. PREVIOUSLY...THERE WERE INDICATIONS OF A GALE EVENT THU NIGHT/FRI AFTER A COLD FRONT PASSES. HOWEVER...IT NOW APPEARS THAT THE FRONT WILL BE WEAKER SO THAT WINDS WILL REMAIN BLO GALE FORCE. LIGHTEST WINDS THIS WEEK WILL OCCUR TUE AS A HIGH PRES RIDGE QUICKLY SHIFTS ACROSS THE UPPER GREAT LAKES. STRONGEST WINDS THIS WEEK WILL OCCUR LATE TUE NIGHT/WED OVER THE E HALF OF LAKE SUPERIOR IN THE SOUTHERLY FLOW AHEAD OF THE AFOREMENTIONED COLD FRONT AND THEN LATE THU/FRI AFTER THE FRONT PASSES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...JLB MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
207 AM EST MON NOV 23 2015 .SYNOPSIS... A HIGH AMPLITUDE UPPER TROUGH EXTENDING FROM CENTRAL CANADA TO THE EASTERN U.S. WILL BRING MAINLY DRY CONDITIONS AND BELOW NORMAL TEMPERATURES THROUGH TUESDAY. A GRADUAL WARMUP AND CONTINUED DRY WEATHER WILL FOLLOW FOR WEDNESDAY THROUGH FRIDAY AS A LARGE AREA OF HIGH PRESSURE DRIFTS EAST AND OFF THE MID ATLANTIC SEABOARD. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE STATE LATE FRIDAY INTO SATURDAY WITH THE NEXT CHANCE OF RAIN SHOWERS...CHANGING TO SCATTERED SNOW SHOWERS ON SATURDAY. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... A LOW PWAT AIR MASS...RELATIVELY LOW SUBSIDENCE INVERSION HGTS OF JUST 4-5 KFT AGL OR SO...AND LIMITED MFLUX OFF OF LK ERIE FROM CROSS LAKE/NWRLY FLOW WILL LEAD TO CLOUDS AND THE LIKELIHOOD OF MAINLY LIGHT SNOW SHOWERS ACROSS WARREN AND MCKEAN COUNTIES EARLY TODAY... WHILE SKIES ACROSS MUCH OF THE REST OF THE REGION WILL BE CLEAR TO PARTLY CLOUDY. 05Z HRRR SHOWS ALMOST NO MEASURABLE SNOW FALLING FROM THE GENERALLY SHALLOW STRATO CU DECK ACROSS THE NW MTNS...THOUGH SFC OBS BENEATH THIS CLOUD SHIELD /SUCH AS KELZ/ SUGGESTS THAT ADDITIONAL LIGHT ACCUMS OF SNOW /ANOTHER COATING TO 1.5 INCHES/ COULD OCCUR THIS MORNING INVOF KBFD AND AREAS TO THE WEST ACROSS WARREN COUNTY. LOW TEMPS EARLY THIS MONDAY SHOULD DIP INTO THE UPPER TEENS ACROSS SOME NORTHERN AND WESTERN MTN LOCATIONS...WITH THE REST OF THE REGION SEEING MINS IN THE 20S. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/... A WEAK CLIPPER WILL MOVE QUICKLY SE FROM THE UPPER GLAKES THIS AFTERNOON INTO TUESDAY. WAA AHEAD OF THIS SYSTEM COULD PRODUCE A BIT OF LGT SNOW/FLURRIES THIS EVENING...MAINLY OVR THE NW MTNS. BLEND OF LATEST MDL OUTPUT SUPPORTS NOTHING MORE THAN A FRESH DUSTING OVER THE NW COUNTIES. HIGH TEMPS THIS AFTERNOON WILL RANGE FROM NEAR 32F OVR THE HIGHER TERRAIN OF NRN AND WRN PENN...TO THE LOWER 40S ACROSS THE SOUTHEAST PART OF OUR CWA. IN GENERAL...WINDS SHOULD BE FAIRLY LIGHT BENEATH SFC RIDGE AS IT SLIDES EAST ACROSS PENN TODAY. HOWEVER...BUFKIT SUGGESTS SW WINDS COULD GUST AS HIGH AS 20KTS ACROSS THE W MTNS LATE TODAY...AS THE LLVL P-GRADIENT TIGHTENS BETWEEN WEAK LOW PRESSURE OVR THE GRT LKS...AND HIGH PRES OVR THE SOUTHERN STATES. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... A MODERATION OF TEMPERATURES WILL BE STARTING NEAR THE BEGINNING OF THE LONG TERM PERIOD AS UPPER PATTERN TRANSITIONS TOWARD MORE ZONAL FLOW EARLY IN THE WEEK...THEN SOUTHWESTERLY FLOW IN RISING HEIGHTS IN RESPONSE TO A DIGGING UPPER TROF OVER THE WESTERN U.S. INTERMOUNTAIN REGION. AT THE SURFACE HIGH PRESSURE WILL DOMINATE OUR WEATHER TUESDAY TO FRIDAY...THE CENTER OF THE HIGH WILL DRIFT OVER THE WESTERN ATLANTIC...THE PATTERN IMPLIES LOW-LEVEL TRAPPED COLD AIR AS WARM AIR BUILDS IN ALOFT AND A RIDGE BUILDS AT 500 MB TO OUR WEST. A WARM LOOKING PATTERN ABOVE THE SURFACE. THE DEEP SOUTHWEST FLOW IMPLIES INCREASED CHANCE RAIN TOWARD THE WEEKEND BUT NOTHING AT THIS TIME TO FOCUS ON. THE 850 MB TEMPERATURES WILL BE A BIT ABOVE NORMAL BY THANKSGIVING AND PERHAPS INTO EARLY SATURDAY. LOTS OF UNCERTAINTY AND SOME GEFS AND NAEFS MEMBERS SHOW COLD AIR SAGGING SOUTH FRIDAY-SATURDAY. SO THE GEFS SHOWS SLIGHTLY ABOVE NORMAL TEMPERATURES WED-FRIDAY BUT LATE FRIDAY-SATURDAY THE 2M TEMPERATURE PLUMES SHOW HUGE SPREAD AND LOTS OF UNCERTAINTY. WILL IT GET WARM OR A SHALLOW FRONT SLIDE THROUGH? INITIALLY THE MEDIAN IS HIGHER THEN THE MEAN...FRIDAY SHOULD BE WARM...SATURDAY THE MEDIAN IS BELOW THE MEAN...SATURDAY HIGHER PROBABILITY OF BEING COLDER THAN FORECAST AS WE TEND TO THE MEAN. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT ISSUED AT 134 AM EST MON NOV 23 2015 IR SATELLITE LOOP SHOWS AREA OF MVFR TO LOW VFR CIGS COVERING THE NW 1/3 OF THE AIRSPACE PUSHING SOUTHEAST APPROACHING FIG/UNV/IPT. LIGHT SNOW SHOWERS/FLURRIES MAY ALSO EXPAND ACROSS THIS AREA BUT ISOLD VIS RESTRICTIONS SHOULD BE LIMITED TO MVFR. EXPECT LINGERING SNOW TO DIMINISH BY THE AFTERNOON WITH MAINLY VFR CONDITIONS. SFC WINDS 8-10KTS FROM 280-320 DEGREES THROUGH THE AFTERNOON /GUSTS 15-20KTS AT MDT-LNS/ WILL DECREASE AND BACK TO 200-250 DEGREES BY TONIGHT. VFR SHOULD PREVAIL AT MOST SITES OVERNIGHT BUT MVFR CIGS COULD RETURN TO THE NW AIRSPACE BY EARLY TUESDAY MORNING. OUTLOOK...TUESDAY-FRIDAY TUE...MVFR CIGS AND SCATTERED SNOW SHOWERS PSBL NW. WED...VFR/NO SIG WX EXPECTED. THU...LOW CIGS PSBL/NO SIG WX EXPECTED. FRI...VFR/MVFR WITH RAIN SHOWERS PSBL MAINLY FRIDAY NIGHT. && .CLIMATE... UPDATED AT 210 AM EST MON NOV 23 2015 WITH 8 DAYS LEFT IN THE MONTH...PRELIMINARY CLIMATE DATA INDICATES THAT NOVEMBER 2015 CURRENTLY RANKS AS THE WARMEST NOVEMBER ON RECORD AT OUR TWO LONG TERM CLIMATE SITES: HARRISBURG AND WILLIAMSPORT. A CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT EACH SITE SINCE 1888 AND 1895 RESPECTIVELY. THROUGH 11/22... THE AVG. MONTHLY TEMPERATURE AT HARRISBURG IS 52.2 DEGREES OR +6.6 DEGREES ABOVE NORMAL. THE AVG. MONTHLY TEMPERATURE AT WILLIAMSPORT IS 50.0 DEGREES OR +6.9 DEGREES ABOVE NORMAL. THE TOP 5 WARMEST NOVEMBERS (8 DAYS LEFT FOR 2015) MDT: 2015 (52.2), 1931 (51.3), 1975 (50.0), 1999 (49.3), 1994 (49.0) IPT: 2015 (50.0), 1931 (48.8), 1902 (47.3), 2009/1972 (47.2), 1913 (46.3) && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...FITZGERALD/LAMBERT SHORT TERM...FITZGERALD/LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...STEINBUGL CLIMATE...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
200 AM EST MON NOV 23 2015 .SYNOPSIS... A HIGH AMPLITUDE UPPER TROUGH EXTENDING FROM CENTRAL CANADA TO THE EASTERN U.S. WILL BRING MAINLY DRY CONDITIONS AND BELOW NORMAL TEMPERATURES THROUGH TUESDAY. A GRADUAL WARMUP AND CONTINUED DRY WEATHER WILL FOLLOW FOR WEDNESDAY THROUGH FRIDAY AS A LARGE AREA OF HIGH PRESSURE DRIFTS EAST AND OFF THE MID ATLANTIC SEABOARD. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE STATE LATE FRIDAY INTO SATURDAY WITH THE NEXT CHANCE OF RAIN SHOWERS...CHANGING TO SCATTERED SNOW SHOWERS ON SATURDAY. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... A LOW PWAT AIR MASS...RELATIVELY LOW SUBSIDENCE INVERSION HGTS OF JUST 4-5 KFT AGL OR SO...AND LIMITED MFLUX OFF OF LK ERIE FROM CROSS LAKE/NWRLY FLOW WILL LEAD TO CLOUDS AND THE LIKELIHOOD OF MAINLY LIGHT SNOW SHOWERS ACROSS WARREN AND MCKEAN COUNTIES EARLY TODAY... WHILE SKIES ACROSS MUCH OF THE REST OF THE REGION WILL BE CLEAR TO PARTLY CLOUDY. 05Z HRRR SHOWS ALMOST NO MEASURABLE SNOW FALLING FROM THE GENERALLY SHALLOW STRATO CU DECK ACROSS THE NW MTNS...THOUGH SFC OBS BENEATH THIS CLOUD SHIELD /SUCH AS KELZ/ SUGGESTS THAT ADDITIONAL LIGHT ACCUMS OF SNOW /ANOTHER COATING TO 1.5 INCHES/ COULD OCCUR THIS MORNING INVOF KBFD AND AREAS TO THE WEST ACROSS WARREN COUNTY. LOW TEMPS EARLY THIS MONDAY SHOULD DIP INTO THE UPPER TEENS ACROSS SOME NORTHERN AND WESTERN MTN LOCATIONS...WITH THE REST OF THE REGION SEEING MINS IN THE 20S. && .SHORT TERM /8 AM THIS MORNING THROUGH 8 AM TUESDAY/... A WEAK CLIPPER WILL MOVE QUICKLY SE FROM THE UPPER GLAKES THIS AFTERNOON INTO TUESDAY. WAA AHEAD OF THIS SYSTEM COULD PRODUCE A BIT OF LGT SNOW/FLURRIES THIS EVENING...MAINLY OVR THE NW MTNS. BLEND OF LATEST MDL OUTPUT SUPPORTS NOTHING MORE THAN A FRESH DUSTING OVER THE NW COUNTIES. HIGH TEMPS THIS AFTERNOON WILL RANGE FROM NEAR 32F OVR THE HIGHER TERRAIN OF NRN AND WRN PENN...TO THE LOWER 40S ACROSS THE SOUTHEAST PART OF OUR CWA. IN GENERAL...WINDS SHOULD BE FAIRLY LIGHT BENEATH SFC RIDGE AS IT SLIDES EAST ACROSS PENN TODAY. HOWEVER...BUFKIT SUGGESTS SW WINDS COULD GUST AS HIGH AS 20KTS ACROSS THE W MTNS LATE TODAY...AS THE LLVL P-GRADIENT TIGHTENS BETWEEN WEAK LOW PRESSURE OVR THE GRT LKS...AND HIGH PRES OVR THE SOUTHERN STATES. && .LONG TERM /TUESDAY THROUGH SUNDAY/... A MODERATION OF TEMPERATURES WILL BE STARTING NEAR THE BEGINNING OF THE LONG TERM PERIOD AS UPPER PATTERN TRANSITIONS TOWARD MORE ZONAL FLOW EARLY IN THE WEEK...THEN SOUTHWESTERLY FLOW IN RISING HEIGHTS IN RESPONSE TO A DIGGING UPPER TROF OVER THE WESTERN U.S. INTERMOUNTAIN REGION. AT THE SURFACE HIGH PRESSURE WILL DOMINATE OUR WEATHER TUESDAY TO FRIDAY...THE CENTER OF THE HIGH WILL DRIFT OVER THE WESTERN ATLANTIC...THE PATTERN IMPLIES LOW-LEVEL TRAPPED COLD AIR AS WARM AIR BUILDS IN ALOFT AND A RIDGE BUILDS AT 500 MB TO OUR WEST. A WARM LOOKING PATTERN ABOVE THE SURFACE. THE DEEP SOUTHWEST FLOW IMPLIES INCREASED CHANCE RAIN TOWARD THE WEEKEND BUT NOTHING AT THIS TIME TO FOCUS ON. THE 850 MB TEMPERATURES WILL BE A BIT ABOVE NORMAL BY THANKSGIVING AND PERHAPS INTO EARLY SATURDAY. LOTS OF UNCERTAINTY AND SOME GEFS AND NAEFS MEMBERS SHOW COLD AIR SAGGING SOUTH FRIDAY-SATURDAY. SO THE GEFS SHOWS SLIGHTLY ABOVE NORMAL TEMPERATURES WED-FRIDAY BUT LATE FRIDAY-SATURDAY THE 2M TEMPERATURE PLUMES SHOW HUGE SPREAD AND LOTS OF UNCERTAINTY. WILL IT GET WARM OR A SHALLOW FRONT SLIDE THROUGH? INITIALLY THE MEDIAN IS HIGHER THEN THE MEAN...FRIDAY SHOULD BE WARM...SATURDAY THE MEDIAN IS BELOW THE MEAN...SATURDAY HIGHER PROBABILITY OF BEING COLDER THAN FORECAST AS WE TEND TO THE MEAN. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT ISSUED AT 134 AM EST MON NOV 23 2015 IR SATELLITE LOOP SHOWS AREA OF MVFR TO LOW VFR CIGS COVERING THE NW 1/3 OF THE AIRSPACE PUSHING SOUTHEAST APPROACHING FIG/UNV/IPT. LIGHT SNOW SHOWERS/FLURRIES MAY ALSO EXPAND ACROSS THIS AREA BUT ISOLD VIS RESTRICTIONS SHOULD BE LIMITED TO MVFR. EXPECT LINGERING SNOW TO DIMINISH BY THE AFTERNOON WITH MAINLY VFR CONDITIONS. SFC WINDS 8-10KTS FROM 280-320 DEGREES THROUGH THE AFTERNOON /GUSTS 15-20KTS AT MDT-LNS/ WILL DECREASE AND BACK TO 200-250 DEGREES BY TONIGHT. VFR SHOULD PREVAIL AT MOST SITES OVERNIGHT BUT MVFR CIGS COULD RETURN TO THE NW AIRSPACE BY EARLY TUESDAY MORNING. OUTLOOK...TUESDAY-FRIDAY TUE...MVFR CIGS AND SCATTERED SNOW SHOWERS PSBL NW. WED...VFR/NO SIG WX EXPECTED. THU...LOW CIGS PSBL/NO SIG WX EXPECTED. FRI...VFR/MVFR WITH RAIN SHOWERS PSBL MAINLY FRIDAY NIGHT. && .CLIMATE... UPDATED AT 138 AM EST SUN NOV 22 2015 WITH 9 DAYS LEFT IN THE MONTH...PRELIMINARY CLIMATE DATA INDICATES THAT NOVEMBER 2015 CURRENTLY RANKS AS THE WARMEST NOVEMBER ON RECORD AT OUR TWO LONG TERM CLIMATE SITES: HARRISBURG AND WILLIAMSPORT. A CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT EACH SITE SINCE 1888 AND 1895 RESPECTIVELY. THROUGH 11/21... THE AVG. MONTHLY TEMPERATURE AT HARRISBURG IS 52.7 DEGREES OR +6.9 DEGREES ABOVE NORMAL. THE AVG. MONTHLY TEMPERATURE AT WILLIAMSPORT IS 50.4 DEGREES OR +7.1 DEGREES ABOVE NORMAL. THE TOP 5 WARMEST NOVEMBERS (CURRENT RANKINGS) MDT: 2015 (52.7), 1931 (51.3), 1975 (50.0), 1999 (49.3), 1994 (49.0) IPT: 2015 (50.4), 1931 (48.8), 1902 (47.3), 2009/1972 (47.2), 1913 (46.3) && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT/FITZGERALD LONG TERM...LAMBERT/GARTNER AVIATION...STEINBUGL CLIMATE...STEINBUGL
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
928 AM EST MON NOV 23 2015 ...WIDESPREAD FROST AND FREEZE CONDITIONS LIKELY TONIGHT AWAY FROM THE COAST... .SYNOPSIS... HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH THE END OF THE WEEK. A WEAK COASTAL TROUGH COULD FORM DURING THE MIDDLE OF THE WEEK JUST OFF THE SOUTHEAST COAST. A COLD FRONT IS EXPECTED TO DROP THROUGH THE AREA FROM THE NORTH OVER THE WEEKEND...FOLLOWED BY A STORM SYSTEM FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGH PRESSURE WILL EXTEND ACROSS THE REGION TODAY. LOW-LEVEL THICKNESS SCHEMES COUPLED WITH THE LATEST RAP FORECAST SOUNDINGS SUPPORT HIGHS FROM THE LOWER 50S NORTH TO THE UPPER 50S ALONG THE ALTAMAHA RIVER. WINDS HAVE DIMINISHED ENOUGH ON LAKE MOULTRIE TO CANCEL THE LAKE WIND ADVISORY A BIT EARLY. THE FORECAST IS VERY MUCH ON TRACK AND DID NOT REQUIRE ANY MEANINGFUL CHANGES. WITH REGARDS TO TONIGHT...A WIDESPREAD FREEZE IS EXPECTED ACROSS INLAND AREAS. INCOMING DATA SUPPORT THE ONGOING FREEZE WARNING AREA WHERE A FREEZE OF 4-7 HOURS IS LIKELY. THE FREEZE IS A BIT MORE MARGINAL ACROSS ALONG THE LOWER SOUTH CAROLINA COASTAL COUNTIES AND SOUTH OF THE I-16 CORRIDOR...THERE A FREEZE WATCH IS CURRENTLY VALID. THE FREEZE WATCH WILL EITHER BE UPGRADED TO A FREEZE WARNING OR A FROST ADVISORY LATER TODAY AFTER THE FULL SUITE OF 12Z MODEL DATA ARE REVIEWED. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TONIGHT...HIGH PRESSURE WILL NUDGE CLOSER SETTING UP SOUTHEAST MONDAY NIGHT...SETTING UP FAVORABLE RADIATIONAL COOLING. WITH DEWPOINTS IN THE 20S TEMPERATURES WILL FALL QUICKLY AFTER SUNSET AND SHOULD REACH NEAR 30 FOR MOST INLAND AREAS AND CLOSER TO 40 NEAR THE COAST. WE HAVE A FREEZE WARNING UP FOR NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA WHERE THERE IS A HIGHER LIKELIHOOD OF FREEZING TEMPERATURES...MAINLY NORTH AND WEST OF CHARLESTON...BEAUFORT...SAVANNAH AND CLAXTON. ELSEWHERE EXCEPT ALONG THE GEORGIA COAST THERE IS A FREEZE WATCH FOR THE POTENTIAL OF FREEZING TEMPERATURES...MAINLY INLAND OF HWY 17 IN SOUTH CAROLINA AND WEST OF I-95 IN GEORGIA. IN ADDITION...MOST AREAS AWAY FROM THE IMMEDIATE COAST SHOULD SEE FROST SO THOSE FOLKS WITH SENSITIVE VEGETATION ARE URGED TO TAKE PROPER PRECAUTIONS. TUESDAY AND TUESDAY NIGHT...BENEATH A NEARLY ZONAL FLOW ALOFT...A LARGE AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTHWEST. A VERY DRY ATMOSPHERIC COLUMN WILL RESULT IN MAINLY CLEAR SKIES THROUGH AT LEAST TUESDAY EVENING. TEMPERATURES WILL REMAIN BELOW NORMAL...BUT START A SLOW MODERATING TREND WITH HIGHS IN THE LOWER 60S AND NIGHTTIME LOWS IN THE MID TO UPPER 30S WELL INLAND AND LOWER TO MID 40S CLOSER TO THE COAST...BUT NEAR 50 ALONG PARTS OF THE IMMEDIATE GEORGIA COAST. WEDNESDAY AND WEDNESDAY NIGHT...THE SURFACE HIGH WILL BUILD SOUTHWARD INTO THE REGION AS IT SHIFTS ACROSS NEW ENGLAND ON WEDNESDAY AND EVENTUALLY EAST OF NOVA SCOTIA WEDNESDAY NIGHT. AS THIS OCCURS...A WEAK COASTAL TROUGH IS EXPECTED TO TAKE SHAPE JUST OFF THE SOUTHEAST U.S. COAST. AN ENHANCED NORTHEAST FLOW WILL ADVECT LOW LEVEL MOISTURE ONSHORE RESULTING IN AN INCREASE IN CLOUD COVER. ISOLATED SHOWERS COULD DEVELOP ALONG THE IMMEDIATE SOUTHEAST GEORGIA COAST ON WEDNESDAY...AND BECOME MORE PROBABLE FOR ALL COASTAL AREAS BY WEDNESDAY NIGHT. HIGHS DURING THE DAY WILL BE IN THE MID 60S MOST AREAS...WITH LOWS WEDNESDAY NIGHT RANGING FROM THE MID 40S WELL INLAND TO THE MID 50S ALONG THE GEORGIA COAST. THANKSGIVING DAY...UPPER LEVEL RIDGING WILL EXPAND OVER THE REGION FROM THE SOUTHERN GULF OF MEXICO AS SURFACE HIGH PRESSURE SHIFTS WELL OUT INTO THE ATLANTIC...HELPING TO MAINTAIN A NORTHEAST FLOW ACROSS THE AREA. ISOLATED SHOWERS WILL STILL BE POSSIBLE FOR COASTAL AREAS GIVEN THE INFLUX OF ATLANTIC MOISTURE AND SOME LOW LEVEL CONVERGENCE NEAR THE COAST. BENEATH THE STRENGTHENING RIDGE...HIGHS SHOULD BE IN THE UPPER 60S TO AROUND 70 ACROSS THE AREA. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... UPPER LEVEL RIDGING WILL EXTEND OVER THE REGION FROM THE GULF OF MEXICO LATE IN THE WEEK INTO THE START OF THE WEEKEND...BEFORE FLATTENING OUT AS AN UPPER LEVEL TROUGH PASSES OFF THE MID-ATLANTIC COAST LATE SATURDAY AND SATURDAY NIGHT. A POTENT UPPER LEVEL LOW WILL THEN TRACK EASTWARD FROM THE NORTHERN PLAINS TO THE UPPER MISSISSIPPI VALLEY/OHIO VALLEY LATE IN THE WEEKEND INTO EARLY NEXT WEEK. MEANWHILE AT THE SURFACE...HIGH PRESSURE WILL PREVAIL OVER THE AREA ON FRIDAY. MODELS THEN DIVERGE WITH THE GFS INDICATING A BACKDOOR COLD FRONT DROPPING THROUGH THE AREA OVER THE WEEKEND...BUT THE ECMWF KEEPS THE FRONT TO THE NORTH. A STORM SYSTEM THEN APPROACHES FROM THE WEST EARLY NEXT WEEK. AS FOR EXPECTED WEATHER CONDITIONS...RAIN-FREE CONDITIONS WILL PREVAIL ON FRIDAY AND SATURDAY...BUT A SLIGHT CHANCE OF SHOWERS IS POSSIBLE ON SUNDAY DEPENDING ON THE POSITION OF THE FRONT. RAIN PROBABILITIES THEN INCREASE WELL INTO THE CHANCE CATEGORY SUNDAY NIGHT THROUGH MONDAY WITH THE APPROACHING STORM SYSTEM. TEMPERATURES WILL RISE ABOVE NORMAL FRIDAY AND SATURDAY...THEN LIKELY FALL BELOW NORMAL FOR SUNDAY AND MONDAY. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... VFR. EXTENDED AVIATION OUTLOOK...VFR. && .MARINE... TODAY AND TONIGHT...HIGH PRESSURE WILL BUILD INTO THE AREA MEANING GENERALLY IMPROVING CONDITIONS AS THE PRESSURE GRADIENT AND COLD ADVECTION DIMINISH. SMALL CRAFT ADVISORIES REMAIN UP FOR THE NEAR SHORE WATERS THROUGH EARLY AFTERNOON AND BEYOND 20 NM THROUGH AROUND MIDNIGHT. TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE WATERS AND PERSIST INTO MID-WEEK. A TROUGH OF LOW PRESSURE WILL THEN DEVELOP MID-WEEK...LEADING TO A STRONGER PRESSURE GRADIENT OVER THE COASTAL WATERS WITH ENHANCED NORTHEAST FLOW. SMALL CRAFT ADVISORIES APPEAR TO RETURN ON WEDNESDAY FOR MOST WATERS OUTSIDE THE CHARLESTON HARBOR...AND COULD PERSIST INTO AT LEAST LATE WEEK. && .TIDES/COASTAL FLOODING... TIDE LEVELS WILL BE ELEVATED THROUGH THE WEEK DUE TO THE FULL MOON...LUNAR PERIGEE AND PERSISTENT NORTHEAST WINDS. TIDAL FLOODING COULD REACH MODERATE LEVELS BY THE TUESDAY MORNING HIGH TIDE...AND MINOR TO MODERATE TIDAL FLOODING WILL THEN BE POSSIBLE WITH EACH HIGH TIDE CYCLE THROUGH AT LEAST MID-WEEK...IF NOT LONGER. THE MORNING HIGH TIDE CYCLE APPEARS TO BE THE GREATER OF THE TWO...AND THERE IS INCREASING CONCERN THAT MAJOR COASTAL FLOODING COULD BE AN ISSUE WEDNESDAY AND POSSIBLY THURSDAY MORNING GIVEN STRONG NORTHEAST WINDS JUST OFFSHORE. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WARNING FROM 1 AM TO 9 AM EST TUESDAY FOR GAZ087-088- 099>101. FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR GAZ114>116-118-137-138. SC...FREEZE WARNING FROM 1 AM TO 9 AM EST TUESDAY FOR SCZ040- 042>045-047-052. FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR SCZ048>051. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ350- 352. SMALL CRAFT ADVISORY UNTIL 1 AM EST TUESDAY FOR AMZ374. SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ330. && $$ ST
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
646 AM EST MON NOV 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM EST MON NOV 23 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF EXTENDING S THRU THE GREAT LAKES REGION. SHEARED OUT SHORTWAVE/LEFT EXIT OF 120+KT UPPER JET EXTENDING FROM SASKATCHEWAN INTO THE UPPER MISSISSIPPI VALLEY HAS GENERATED SOME AREAS OF -SN INTO WRN UPPER MI OVERNIGHT. MODELS OVER THE LAST DAY OF RUNS CORRECTLY TRENDED LIGHTER WITH THIS PCPN AS SNOW THAT HAS OCCURRED HAS BEEN VERY LIGHT WITH NOT MUCH MORE THAN A DUSTING OF ACCUMULATION WHERE SNOW HAS FALLEN PER WEBCAMS. TO THE E...JUST AS SOME HIGH RES MODELS WERE INDICATING 24 HRS AGO...THE REGIONAL CANADIAN IN PARTICULAR...A BURST OF HVY SNOW MOVED N OFF NRN LAKE MI INTO PARTS OF THE ERN U.P. OVER THE LAST SEVERAL HRS. IT APPEARS THE EXTREME SE CORNER OF LUCE COUNTY PROBABLY SAW A VERY BRIEF PERIOD OF MDT TO HVY SNOW AROUND 06Z. THAT AREA OF MDT/HVY SNOW HAS SHIFTED E INTO THE STRAITS VCNTY SINCE THEN. THERE IS STILL SOME CONCERN FOR LAKE ENHANCED SNOW OFF NRN LAKE MI TO SHIFT/REFORM BACK TO THE W TODAY. ON THE HIGH EXTREME IS THE REGIONAL CANADIAN WHICH GENERATES 0.3 INCHES OF QPF IN THE FAR SE CORNER OF LUCE COUNTY BTWN 15Z AND 00Z. SINCE THE MAJORITY OF AVBL HIGH RES GUIDANCE...INCLUDING THE HIGH RES CANADIAN...KEEPS THE BULK OF REDEVELOPING LAKE ENHANCED SNOW JUST E OF LUCE COUNTY...WILL KEEP SNOW AMOUNTS UNDER ADVY CRITERIA WITH PERHAPS 1.5-2 INCHES TO THE SE OF KERY. ELSEWHERE....PATCHY -SN MOVING ACROSS WRN UPPER MI ATTM SHOULD DISSIPATE OVER THE NEXT SEVERAL HRS AS IT SHIFTS E AND HAS TO OVERCOME INITIAL DRY LOWER LEVEL AIR. THEN...A SFC LOW PRES TROF WILL SWING INTO WRN UPPER MI LATE MORNING/AFTN...BRINGING A WIND SHIFT TO THE W TO NW. EXPECT -SHSN TO ACCOMPANY THE TROF AS OVERLAKE INSTABILITY WITH 850MB TEMPS AROUND -7C WILL BE MORE THAN SUFFICIENT TO GENERATE -SHSN ALONG THE TROF/CONVERGENCE ZONE AS IT CROSSES WRN LAKE SUPERIOR. THIS WILL THEN TRANSITION TO SCT LAKE EFFECT -SHSN INTO TONIGHT FOR AREAS FAVORED BY NW WINDS AS 850MB TEMPS DROP A DEGREE OR TWO C. INITIALLY...INVERSION IS UP AROUND 7KFT THIS EVENING...BUT FALLS TO AROUND 4KFT W OVERNIGHT AND TO AROUND 5KFT E LATE. DESPITE THE DECENTLY HIGH INVERSION HEIGHTS...SNOW ACCUMULATIONS WILL BE LIMITED DUE TO THE DGZ BEING ABOVE THE CONVECTIVE LAYER. AT THIS POINT...EXPECT ACCUMULATIONS MOSTLY UNDER 1 INCH...BUT IF ANY RELATIVELY STATIONARY BANDS SET UP...THERE CERTAINLY COULD BE ISOLATED 2-3 INCH AMOUNTS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 422 AM EST MON NOV 23 2015 ...RAIN CHANGING TO SNOW WED NIGHT INTO THANKSGIVING DAY WITH ACCUMULATING SNOW POSSIBLE INTO THU NIGHT... IN LARGER SCALE...DEEP TROUGH OVER EASTERN CONUS SLIDES TO EASTERN CANADA ON TUE WHILE SPLIT FLOW TROUGHING DEVELOPS WESTERN CANADA TO WESTERN CONUS. 1000-850MB TROUGH FORMING ON TUE OVER ROCKIES AND ADJACENT PLAINS AND LOW-LEVEL HIGH PRESSURE SETTLING TO SOUTHEAST CONUS WILL ALLOW S/SE WINDS AT SFC TO BRING INCREASING MOISTURE OFF THE GULF OF MEXICO TOWARD THE MIDDLE MISSISSIPPI RIVER VALLEY. WILL STAY DRY OVER UPR LAKES ON TUE BUT LATE TUE NIGHT INTO WED MORNING SOUNDINGS SHOW INCREASING MOISTURE BLO H9 INTO UPPER GREAT LAKES. IF THERE IS ANY PRECIP AROUND ON WED MORNING...IT LIKELY WOULD TAKE FORM OF DZ/FZDZ DEPENDING ON SFC TEMPS. BEST CHANCE FOR LIGHT ICING WOULD BE OVER INTERIOR CNTRL CWA FM IRON/DICKINSON INTO BARAGA AND WESTERN MARQUETTE COUNTY. MODELS SOMETIMES ARE TOO OVERDONE ON THIS TYPE OF LOW-LEVEL MOISTENING BUT IN THIS CASE THERE IS DECENT SNOW PACK JUST TO THE SOUTH SO THAT MAY HELP THE EXPANSION OF LOW-LEVEL MOISTURE. LATER ON WEDNESDAY DEEPER MOISTURE AND LARGER SCALE FORCING INCREASE STEADILY AHEAD OF SHORTWAVE TROUGH SLIDING OVER MANTIOBA AND NORTHERN ONTARIO. LOW-LEVEL THETA-E ADVECTION INCREASES BRIEFLY BEFORE BEING SHUNTED TO THE SOUTH AND EAST ON WED NIGHT. SHOULD SEE LIGHT RAIN BECOME MORE WIDESPREAD...BUT WITHOUT MUCH OF STRONG MOISTURE TAP AHEAD OF THE TROUGH WITH THE NORTHERN STREAM SHORTWAVE TROUGH...RAINFALL AMOUNTS SHOULD BE LIGHT. COOLER AIR WITH H85 TEMPS DOWN BLO -2C SLIDES IN AFTER MIDNIGHT WED NIGHT OVER THE WEST AND THAT SHOULD TURN ANY LINGERING RAIN TO SNOW. GFS SOUNDINGS AND H85- H7 RH FIELDS FM THE ECMWF INDICATE MID-LEVEL DRYING MAY LEAD TO CHANCES OF FREEZING DRIZZLE OR DRIZZLE INSTEAD OF SNOW LATE WED NIGHT INTO THANKSGIVING MORNING WITH MOIST LAYER AT TEMPS BLO 0C BUT MUCH WARMER THAN -10C. UPSLOPE FLOW OFF LK SUPERIOR WOULD ALSO AID IN LOW-LEVEL LIFT AND MAYBE LEAD TO GREATER CHANCES OF DRIZZLE FOR WEST AND NCNTRL UPR MICHIGAN. ADDED MENTION OF DZ/FZDZ IN THE GRIDS FOR THESE AREAS. ATTN LATER ON THANKSGIVING TURNS TO WAVE OF LOW PRESSURE THAT RIDES NORTHEAST ALONG THE TROUGH OVER THE UPR GREAT LAKES. 00Z ECMWF TRENDED FARTHER WEST WITH THE WAVE WHILE THE GFS TRENDED FARTHER EAST. IF THE ECMWF IS CORRECT SWATH OF MODERATE PRECIP WOULD LIFT BACK OVER AT LEAST THE SOUTH AND EAST CWA THANKSGIVING AFTN INTO THU NIGHT. SINCE THE INITIAL TROUGH/COLD FRONT IS THROUGH MOST CWA PTYPE WOULD MOSTLY BE SNOW...EXCEPT OVER FAR SCNTRL WHERE WARM AIR LINGERS AS EVEN ECMWF SHOWS H85 TEMPS AT LEAST +1C WHEN HEAVIER QPF IS FORECAST TO MOVE THROUGH. SFC TEMPS STILL MID 30S AS WELL SO NO RISK OF ANY FREEZING PRECIP EITHER. JUST INLAND OVER SOUTH CENTRAL AND OVER MOST OF THE EASTERN CWA /N WINDS LEADING TO OFFSHORE WINDS AT ESC AND ISQ/ COULD SEE SEVERAL INCHES OF WET SNOW WITH THE ECMWF SOLN AS 12 HR QPF BTWN 18Z THU AND 06Z FRI IS AT LEAST 0.5 IF NOT UP TO 0.75 INCH. MEANWHILE...LATEST GFS BARELY IS OVER 0.25 INCHES FOR THAT TIME FRAME. GEM IS MORE LIKE THE ECMWF WITH TOTAL QPF...BUT MUCH WARMER AND WOULD RESULT IN MOSTLY RAIN FOR THOSE AREAS. WPC PREFERRED CONSENSUS OF GFS/ECMWF/GEM. WILL CONTINUE TO MENTION THE RAIN TO SNOW AND SOME ACCUMULATING SNOW IN THE HWO...BUT CANNOT PLAY UP THE SNOW TOO MUCH OR GET TOO SPECIFIC YET GIVEN THE UNCERTAINTIES THAT REMAIN. BEHIND THIS SYSTEM...TURNS COLD ENOUGH FOR LAKE EFFECT SNOW SHOWERS OFF LK SUPERIOR FRI INTO FRI NIGHT. ON FRI...AREAS FAVORED BY N WINDS MAY SEE SOME SNOW FOR A CHANGE...THEN WOULD BE MAINLY NW FLOW AREAS FRI NIGHT. DRY LOW-LEVEL AIRMASS WITH STRONG HIGH BUILDING IN SHOULD LIMIT EXTENT OF LES. BASED ON CURRENT MODEL SOLUTIONS IT IS DOUBTFUL AMOUNTS WOULD REACH ADVY LEVELS FRI-FRI NIGHT. SLIGHT WARMING TREND WITH GENERALLY DRY WEATHER IS EXPECTED FOR NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 644 AM EST MON NOV 23 2015 A DISTURBANCE MOVING ACROSS THE REGION WILL BRING SOME PATCHY -SN THIS MORNING. WITH THE PASSAGE OF A SFC TROF...LAKE EFFECT -SHSN WILL DEVELOP FOR AREAS FAVORED BY NW WINDS THIS AFTN AND TONIGHT. FOR KCMX/KIWD...THIS MEANS MVFR CONDITIONS SHOULD PREVAIL THRU THE FCST PERIOD. AT KSAW...VFR CONDITIONS SHOULD PREVAIL THIS MORNING UNDER LINGERING DRIER AIR AT THE LOW LEVELS...THOUGH THERE MAY A PERIOD OF MVFR VIS IN -SN. VFR SHOULD CONTINUE INTO THE MID AFTN WITH A DOWNSLOPE WESTERLY WIND. MVFR CONDITIONS SHOULD THEN DEVELOP AT KSAW LATE AFTN AND CONTINUE THRU TONIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 450 AM EST MON NOV 23 2015 NO GALES ARE EXPECTED ON LAKE SUPERIOR THRU THE END OF THE WEEK. PREVIOUSLY...THERE WERE INDICATIONS OF A GALE EVENT THU NIGHT/FRI AFTER A COLD FRONT PASSES. HOWEVER...IT NOW APPEARS THAT THE FRONT WILL BE WEAKER SO THAT WINDS WILL REMAIN BLO GALE FORCE. LIGHTEST WINDS THIS WEEK WILL OCCUR TUE AS A HIGH PRES RIDGE QUICKLY SHIFTS ACROSS THE UPPER GREAT LAKES. STRONGEST WINDS THIS WEEK WILL OCCUR LATE TUE NIGHT/WED OVER THE E HALF OF LAKE SUPERIOR IN THE SOUTHERLY FLOW AHEAD OF THE AFOREMENTIONED COLD FRONT AND THEN LATE THU/FRI AFTER THE FRONT PASSES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GLASGOW MT
904 AM MST MON NOV 23 2015 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY... MORNING UPDATE... CHANGES FOR THIS MORNING WERE FOCUSED ON THE LIGHT ECHOS ACROSS THE AREA. A LARGE HOLE EXISTS AROUND THE RADAR ON COMPOSITE MODE AND THEREFORE MOST OF THESE ECHOS ARE NOT REACHING THE GROUND. HOWEVER... WHERE ECHOS EXCEED ROUGHLY 20 TO 25 DBZ SOME LIGHT FLURRIES WILL BE POSSIBLE. SO, HAVE UPDATED WX GRIDS TO INCLUDE FLURRIES THROUGH THE EARLY AFTERNOON. RAP WAS USED TO BLEND INTO THE POPS TO ACCOUNT FOR FLURRIES AS IT SEEMS TO BE ABOUT THE MOST ACCOUNTABLE MODEL AT THE MOMENT. SKY CONDITIONS WERE ALSO TWEAKED SLIGHTLY TO INCLUDE THESE BANDS OF ECHOS PASSING THROUGH. GAH PREVIOUS SHORT TERM DISCUSSION... THE UPPER LEVEL RIDGE FLATTENS OUT TODAY RESULTING IN ZONAL FLOW ALOFT. OFF TO THE WEST A FAST MOVING UPPER TROUGH WILL BE DROPPING SOUTH FROM THE GULF OF ALASKA AND NORTHERN BC. THIS WILL PUSH COLDER AIR SOUTH INTO NORTHEAST MONTANA TODAY. BY 00Z THIS EVENING THE BASE OF THE TROUGH WILL BE TO THE WEST OF WASHINGTON AND BC EJECTING MOISTURE INTO THE SOUTHERN BC AND ALBERTA. THE FLOW DIRECTION WILL AVOID OUR AREA UNTIL TUESDAY. SO EXPECT COOLER BUT CONTINUED DRY CONDITIONS THROUGH TONIGHT. MODELS SUGGEST TUESDAY MORNING AND MUCH OF TUESDAY AFTERNOON STAYING DRY WHILE CLOUDS INCREASE FROM THE NORTHWEST AS THE COLD FRONT DESCENDS INTO MONTANA. THE TROUGH BEGINS TO SPLIT APART WITH THE SOUTHERN PORTION HEADING INTO NORTHERN CALIFORNIA...WHERE IT KEEPS PICKING UP PACIFIC MOISTURE. TUESDAY NIGHT AND WEDNESDAY...THE FAST-MOVING STORM IMPACTS THE LOCAL REGION WITH CAA FROM WIND THAT SHIFTS TO THE NORTH AND PRECIPITATION THAT STARTS AS RAIN...BUT TURNS INTO ACCUMULATING SNOW. AT 00Z WEDNESDAY...LIGHT PRECIPITATION IS JUST MOVING INTO OUR WESTERN COUNTIES. THEN IT SPREADS TOTALLY ACROSS THE AREA OVERNIGHT. AS THE MODELS EVOLVE CLOSER TO THE EVENT...GFS QPF CONTINUES TO TREND LOWER FOR THE CWA...AS EVIDENCED BY THE WPC WINTER DESK ANALYSIS. THE HEAVIEST GFS QPF WILL BE THROUGH CENTRAL MONTANA...THEN SOUTHEAST MONTANA. LOCALLY...QPF SHOULD BE HEAVIEST IN OUR SOUTHWEST AREAS. THE NAM IS MUCH MORE WET WITH QPF AMOUNTS ACROSS SOUTHERN PORTIONS OF THE CWA. DUE TO MODEL DIFFERENCES...WILL CONTINUE TO GO WITH A BLEND. MOST PRECIPITATION WILL END NORTH OF THE MISSOURI RIVER BEFORE NOON WEDNESDAY...AND BEFORE MIDNIGHT SOUTH OF THE MISSOURI. WHAT WILL BE LEFT ARE ROADS THAT MAY BE AFFECTED BY SNOW AND ICE WHICH COULD CAUSE HOLIDAY TRAVEL PROBLEMS. SCT .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE AREAS WEDNESDAY NIGHT. THIS WILL PUSH THE SNOW COMPLETELY SOUTH OF THE FORECAST AREA DURING THE NIGHT POSSIBLY SOONER. WILL MAINTAIN A CHANCE OF SNOW IN THE SOUTH FOR NOW. TEMPERATURES WILL BE SOMEWHAT COLDER THAN NORMAL BUT NOT BITTER COLD AS LOWS IN THE SINGLE DIGITS ARE EXPECTED IN MOST AREAS. THE SURFACE HIGH WILL CONTINUE TO BRING DRY WEATHER ON THURSDAY. A NORTH TO NORTHWEST FLOW ALOFT IN THE NORTHERN BRANCH UPPER TROUGH WILL KEEP TEMPERATURE ABOUT 10 DEGREES BELOW NORMAL. UPPER LEVEL HIGH BUILDS INTO WESTERN CANADA FRIDAY AND SATURDAY WHILE CLOSED UPPER LOW REMAINS OVER NEVADA AND CALIFORNIA. THIS WILL RESULT IN AN UNUSUAL NORTHEAST TO EAST FLOW ALOFT. SINCE THE FLOW ALOFT WILL BE ANTI-CYCLONIC...LOOK FOR DRY WEATHER TO CONTINUE WITH MODERATING TEMPERATURES. MODEL DIFFERENCES START APPEARING OVER THE WEEKEND AS THE GFS WANTS TO BRING THE UPPER LOW TO THE SOUTH TOWARDS MONTANA ON SUNDAY WHILE ECMWF WANTS TO RIDGE THE UPPER HIGH INTO THE AREA AND KEEP THE LOW TO THE SOUTH. WILL LEAN TOWARDS THE DRIER ECMWF FOR NOW AND CONTINUE THE WARMING TREND FOR NOW. THE ECMWF MAINTAINS THAT RIDGE ON MONDAY WHILE THE GFS MOVES THE LOW TO THE EAST. FORRESTER && .AVIATION... VFR WITH A MIX OF MID AND HIGH CLOUDS TODAY AND TONIGHT. A FEW FLURRIES MAY ALSO OCCUR AS A WARM FRONT LIFTS ACROSS THE REGION TODAY. VARIABLE WINDS LESS THAN 10 KNOTS EARLY WILL BECOME EAST TO SOUTHEAST 10 TO 15 KNOTS BY AFTERNOON AND CONTINUE TONIGHT. && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 AM CST MON NOV 23 2015 .UPDATE... ISSUED AT 635 AM CST MON NOV 23 2015 NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE CYCLE OTHER THAN BLENDING RECENT OBSERVATIONS WITH SHORT TERM MODEL GUIDANCE. RADAR ECHOES IN NORTHEASTERN MT REFLECT AN INCREASE IN MIDDLE- AND HIGH- LEVEL CLOUDS AND NOT PRECIPITATION DUE TO A DRY LOWER ATMOSPHERE. THAT SCENARIO IS WELL-REFLECTED BY RECENT HRRR ITERATIONS AND THUS THE DRY FORECAST FOR TODAY APPEARS TO BE WELL IN HAND. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CST MON NOV 23 2015 QUIET WEATHER HIGHLIGHTS THE SHORT TERM PERIOD. CURRENTLY...THE STRONG LOW PRESSURE SYSTEM ASSOCIATED WITH YESTERDAY`S WINDY CONDITIONS WAS CENTERED OVER THE BORDER OF MANITOBA/ONTARIO/MINNESOTA. A WEAK HIGH PRESSURE AXIS EXTENDED FROM SOUTHERN ALBERTA SOUTHEASTWARD INTO EASTERN MONTANA AND THE WESTERN DAKOTAS...WITH BROAD LOW PRESSURE DEVELOPING IN THE LEE OF THE ROCKIES. TODAY THE STRONG LOW PRESSURE SYSTEM IS FORECAST TO MOVE EAST TOWARDS THE GREAT LAKES AND HUDSON BAY...AND THE SURFACE HIGH PRESSURE RIDGE AXIS MOVES EASTWARD INTO THE CENTRAL AND EASTERN DAKOTAS AS AN UPPER LEVEL RIDGE BUILDS/EXPANDS FROM THE ROCKIES INTO THE WESTERN PLAINS. MAINLY PARTLY CLOUDY SKIES TODAY WITH MIDDLE/HIGH CLOUDS MOVING EAST INTO NORTH DAKOTA. WARMER AIR IN SOUTHWESTERN NORTH DAKOTA WITH HIGHS IN THE LOWER 40S...WITH COOLER AIR TO THE NORTHEAST WITH HIGHS IN THE MID TO UPPER 30S. TONIGHT THE BROAD UPPER LEVEL RIDGE MIGRATES EASTWARD AND THE FLOW OVER THE ROCKIES BECOMES SOUTHWESTERLY ALOFT. IN RESPONSE...BROAD SURFACE LOW PRESSURE DEVELOPS OVER THE ROCKIES AND FRONT RANGE...AND A LONG BROAD FETCH OF SOUTHERLY SURFACE WINDS DEVELOPS FROM THE SOUTHERN PLAINS NORTHWARD INTO THE NORTHERN PLAINS. A LOW LEVEL JET DEVELOPS...AND THIS WILL ALLOW LOW LEVEL MOISTURE TO STREAM NORTHWARD INTO SOUTH CENTRAL CANADA. LOOK FOR INCREASING LOW CLOUDS WITH SOUTHEASTERLY SURFACE WINDS...AND INCREASING MID LEVEL CLOUDS MOVING IN FROM THE WEST/SOUTHWEST. LOW TEMPERATURES ARE EXPECTED TO BE IN THE 20S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 337 AM CST MON NOV 23 2015 THE FOCUS IN THE LONG TERM IS ON LIGHT SNOW POTENTIAL CENTERED ON WEDNESDAY. WE ARE BECOMING MORE CONFIDENT THAT ACCUMULATIONS WILL BE RELATIVELY LOW WITH THIS EVENT...POTENTIALLY LIMITING IMPACTS. THE 00 UTC MODEL SUITE WAS IN RELATIVELY GOOD AGREEMENT IN SHOWING LIGHT SNOW DEVELOPING IN WESTERN ND BY EARLY WEDNESDAY MORNING AND SPREADING EASTWARD DURING THE DAY. THE MULTI-MODEL CONSENSUS CALLS FOR LIQUID-EQUIVALENT MOISTURE VALUES OF 0.05 TO 0.15 INCHES /MOST IN FAR SOUTHWESTERN ND/...WHICH SHOULD CONTRIBUTE TO SNOW AMOUNTS RANGING FROM LESS THAN ONE-HALF INCH TO THE NORTH AND EAST OF THE MISSOURI RIVER...TO 1 TO 2 INCHES SOUTH AND WEST OF THE MISSOURI RIVER. OUR OFFICIAL FORECAST PRODUCED 3 INCH SNOW TOTALS ONLY IN EXTREME SOUTHWESTERN ND...BOWMAN AND SLOPE COUNTIES...WEDNESDAY THROUGH WEDNESDAY NIGHT. THE SNOW WILL BE GENERATED IN A POST-FRONTAL ENVIRONMENT...DRIVEN MAINLY BY DYNAMICS ASSOCIATED WITH A SHORTWAVE TROUGH EMBEDDED IN THE NORTHERN STREAM OF A SPLIT FLOW. THE 03 UTC SREF LINGERED THE SNOW LONGER THAN THE 00 UTC DETERMINISTIC GUIDANCE...SO A BIT OF UNCERTAINTY REMAINS...BUT IN GENERAL GUIDANCE CONTINUED TO SUGGEST THAT THE PRIMARY VERTICAL MOTION ASSOCIATED WITH THE 500-MB LOW IN THE GREAT BASIN WILL REMAIN DISPLACED SOUTH OF ND. IF THAT IS THE CASE...THANKSGIVING DAY MAY END UP COLD...BUT DRY IN MOST AREAS. ONE OTHER ISSUE WE WILL NEED TO CONSIDER IS WHETHER FOG DEVELOPS TUESDAY NIGHT...AND WHETHER LINGERING WARM AND DRY AIR ALOFT IS CAPABLE OF PRODUCING ANY LIGHT FREEZING RAIN OR LIGHT FREEZING DRIZZLE TUESDAY NIGHT INTO WEDNESDAY MORNING. FORECAST SOUNDINGS ARE NOT PARTICULARLY SUGGESTIVE OF THAT POTENTIAL THOUGH...SO WE ARE NOT MESSAGING THAT RISK AT THIS POINT. A REX BLOCK WILL DEVELOP ALOFT OVER THE WESTERN UNITED STATES BY NEXT WEEKEND AS THE GREAT BASIN LOW GETS PINCHED OFF TO THE SOUTH OF A DEVELOPING 500-MB RIDGE OVER WESTERN CANADA. THIS SCENARIO IS EXPECTED TO GENERATE A WARMING TREND AND MAINLY DRY WEATHER ACROSS THE AREA NEXT WEEKEND...THOUGH THE 00 UTC GFS /AND THE 00 UTC GFS ALONE/ DOES SUGGEST SOME SNOW POTENTIAL RETURNING NEXT SUNDAY WHEN IT BREAKS THE BLOCK DOWN AND KICKS THE REMNANT LOW ALOFT EASTWARD FURTHER NORTH THAN THE REST OF THE 00 UTC MODEL GUIDANCE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 635 AM CST MON NOV 23 2015 VFR CONDITIONS EXPECTED UNTIL AROUND 02Z-06Z MONDAY EVENING...WHEN INCREASING LOW CLOUDS WILL RESULT IN MVFR CIGS AT ALL TAF SITES. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CJS SHORT TERM...JV LONG TERM...CJS AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1221 PM EST MON NOV 23 2015 ...FROST AND FREEZE CONDITIONS TONIGHT... .SYNOPSIS... HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH THE END OF THE WEEK. A WEAK COASTAL TROUGH COULD FORM DURING THE MIDDLE OF THE WEEK JUST OFF THE SOUTHEAST COAST. A COLD FRONT IS EXPECTED TO DROP THROUGH THE AREA FROM THE NORTH OVER THE WEEKEND...FOLLOWED BY A STORM SYSTEM FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO CHANGES WERE NEEDED FOR THE EARLY AFTERNOON UPDATE. SEE THE SHORT TERM PERIOD BELOW FOR INFORMATION ABOUT CHANCES TO THE FROST/FREEZE HEADLINES. HIGH PRESSURE WILL EXTEND ACROSS THE REGION TODAY. LOW-LEVEL THICKNESS SCHEMES COUPLED WITH THE LATEST RAP FORECAST SOUNDINGS SUPPORT HIGHS FROM THE LOWER 50S NORTH TO THE UPPER 50S ALONG THE ALTAMAHA RIVER. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TONIGHT...CANADIAN HIGH PRESSURE WILL BECOME CENTERED JUST THE NORTH OVERNIGHT AS HEIGHTS BUILD ALOFT IN THE WAKE OF THE DEPARTING LONGWAVE TROUGH OFF NEW ENGLAND. THE BOUNDARY LAYER IS POISED TO DECOUPLE QUICKLY AFTER SUNSET WITH CALM WINDS DOMINATING FOR MOST LOCATIONS. CALM WINDS...LOW DEWPOINTS AND CLEAR SKIES WILL PROMOTE STRONG RADIATIONAL COOLING WITH THE STEEPEST THERMAL DECLINES OCCURRING DURING THE EVENING HOURS. THE 23/12Z GUIDANCE HAS TRENDED SLIGHTLY COOLER SO CONFIDENCE HAS INCREASED ENOUGH TO UPGRADE THE REMAINING FREEZE WATCH AREA TO A FREEZE WARNING. A FROST ADVISORY HAS ALSO BEEN ISSUED FOR INLAND MCINTOSH COUNTY WHERE SCATTERED FROST IS LIKELY...BUT A FREEZE IS NOT AS CERTAIN. FREEZE DURATIONS OF 5-8 HOURS ARE LIKELY ACROSS THE FAR INLAND COUNTIES WITH 2-4 HOURS FARTHER EAST AND SOUTH. A FREEZE IS UNLIKELY FOR DOWNTOWN CHARLESTON AND THE HEART OF DOWNTOWN SAVANNAH. LOWS WILL RANGE FROM THE UPPER 20S WELL INLAND TO THE UPPER 40S ALONG THE BEACHES OF NORTH COASTAL GEORGIA. THERE WILL BE A LARGE THERMAL GRADIENT ACROSS THE SOUTH CAROLINA COASTAL ZONES TONIGHT WITH TEMPERATURES RANGING FROM 31-32 WEST OF HIGHWAY 17 AND OUTSIDE OF THE 526 LOOP WITH UPPER 30S IN DOWNTOWN CHARLESTON AND MID 40S AT THE BEACHES. FOR THE GEORGIA COASTAL ZONES...THERE MAY BE JUST ENOUGH OF AN ONSHORE COMPONENT THERE TO KEEP TEMPERATURES WARM ENOUGH TO PRECLUDE SCATTERED FROST. WILL HOLD OFF ON A FROST ADVISORY FOR THOSE ZONES...ALTHOUGH IT MAY BE CLOSE IN COMMUNITIES SUCH AS BETHESDA...FAR WESTERN PORTIONS OF SKIDAWAY ISLAND...HALFMOON LANDING...SHELLMAN BLUFF AND DARIEN. LOWS LOOK TO GO NO LOWER THAN THE UPPER 40S FOR THE IMMEDIATE GEORGIA COAST...INCLUDING TYBEE ISLAND. TUESDAY AND TUESDAY NIGHT...BENEATH A NEARLY ZONAL FLOW ALOFT...A LARGE AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTHWEST. A VERY DRY ATMOSPHERIC COLUMN WILL RESULT IN MAINLY CLEAR SKIES THROUGH AT LEAST TUESDAY EVENING. TEMPERATURES WILL REMAIN BELOW NORMAL...BUT START A SLOW MODERATING TREND WITH HIGHS IN THE LOWER 60S AND NIGHTTIME LOWS IN THE MID TO UPPER 30S WELL INLAND AND LOWER TO MID 40S CLOSER TO THE COAST...BUT NEAR 50 ALONG PARTS OF THE IMMEDIATE GEORGIA COAST. WEDNESDAY AND WEDNESDAY NIGHT...THE SURFACE HIGH WILL BUILD SOUTHWARD INTO THE REGION AS IT SHIFTS ACROSS NEW ENGLAND ON WEDNESDAY AND EVENTUALLY EAST OF NOVA SCOTIA WEDNESDAY NIGHT. AS THIS OCCURS...A WEAK COASTAL TROUGH IS EXPECTED TO TAKE SHAPE JUST OFF THE SOUTHEAST U.S. COAST. AN ENHANCED NORTHEAST FLOW WILL ADVECT LOW LEVEL MOISTURE ONSHORE RESULTING IN AN INCREASE IN CLOUD COVER. ISOLATED SHOWERS COULD DEVELOP ALONG THE IMMEDIATE SOUTHEAST GEORGIA COAST ON WEDNESDAY...AND BECOME MORE PROBABLE FOR ALL COASTAL AREAS BY WEDNESDAY NIGHT. HIGHS DURING THE DAY WILL BE IN THE MID 60S MOST AREAS...WITH LOWS WEDNESDAY NIGHT RANGING FROM THE MID 40S WELL INLAND TO THE MID 50S ALONG THE GEORGIA COAST. THANKSGIVING DAY...UPPER LEVEL RIDGING WILL EXPAND OVER THE REGION FROM THE SOUTHERN GULF OF MEXICO AS SURFACE HIGH PRESSURE SHIFTS WELL OUT INTO THE ATLANTIC...HELPING TO MAINTAIN A NORTHEAST FLOW ACROSS THE AREA. ISOLATED SHOWERS WILL STILL BE POSSIBLE FOR COASTAL AREAS GIVEN THE INFLUX OF ATLANTIC MOISTURE AND SOME LOW LEVEL CONVERGENCE NEAR THE COAST. BENEATH THE STRENGTHENING RIDGE...HIGHS SHOULD BE IN THE UPPER 60S TO AROUND 70 ACROSS THE AREA. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... UPPER LEVEL RIDGING WILL EXTEND OVER THE REGION FROM THE GULF OF MEXICO LATE IN THE WEEK INTO THE START OF THE WEEKEND...BEFORE FLATTENING OUT AS AN UPPER LEVEL TROUGH PASSES OFF THE MID-ATLANTIC COAST LATE SATURDAY AND SATURDAY NIGHT. A POTENT UPPER LEVEL LOW WILL THEN TRACK EASTWARD FROM THE NORTHERN PLAINS TO THE UPPER MISSISSIPPI VALLEY/OHIO VALLEY LATE IN THE WEEKEND INTO EARLY NEXT WEEK. MEANWHILE AT THE SURFACE...HIGH PRESSURE WILL PREVAIL OVER THE AREA ON FRIDAY. MODELS THEN DIVERGE WITH THE GFS INDICATING A BACKDOOR COLD FRONT DROPPING THROUGH THE AREA OVER THE WEEKEND...BUT THE ECMWF KEEPS THE FRONT TO THE NORTH. A STORM SYSTEM THEN APPROACHES FROM THE WEST EARLY NEXT WEEK. AS FOR EXPECTED WEATHER CONDITIONS...RAIN-FREE CONDITIONS WILL PREVAIL ON FRIDAY AND SATURDAY...BUT A SLIGHT CHANCE OF SHOWERS IS POSSIBLE ON SUNDAY DEPENDING ON THE POSITION OF THE FRONT. RAIN PROBABILITIES THEN INCREASE WELL INTO THE CHANCE CATEGORY SUNDAY NIGHT THROUGH MONDAY WITH THE APPROACHING STORM SYSTEM. TEMPERATURES WILL RISE ABOVE NORMAL FRIDAY AND SATURDAY...THEN LIKELY FALL BELOW NORMAL FOR SUNDAY AND MONDAY. && .AVIATION /17Z MONDAY THROUGH FRIDAY/... VFR. EXTENDED AVIATION OUTLOOK...VFR. && .MARINE... TODAY AND TONIGHT...HIGH PRESSURE WILL BUILD INTO THE AREA MEANING GENERALLY IMPROVING CONDITIONS AS THE PRESSURE GRADIENT AND COLD ADVECTION DIMINISH. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GEORGIA OFFSHORE WATERS UNTIL 7 PM. TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE WATERS AND PERSIST INTO MID-WEEK. A TROUGH OF LOW PRESSURE WILL THEN DEVELOP MID-WEEK...LEADING TO A STRONGER PRESSURE GRADIENT OVER THE COASTAL WATERS WITH ENHANCED NORTHEAST FLOW. SMALL CRAFT ADVISORIES APPEAR TO RETURN ON WEDNESDAY FOR MOST WATERS OUTSIDE THE CHARLESTON HARBOR...AND COULD PERSIST INTO AT LEAST LATE WEEK. && .TIDES/COASTAL FLOODING... TIDE LEVELS WILL BE ELEVATED THROUGH THE WEEK DUE TO THE FULL MOON...LUNAR PERIGEE AND PERSISTENT NORTHEAST WINDS. TIDAL FLOODING COULD REACH MODERATE LEVELS BY THE TUESDAY MORNING HIGH TIDE...AND MINOR TO MODERATE TIDAL FLOODING WILL THEN BE POSSIBLE WITH EACH HIGH TIDE CYCLE THROUGH AT LEAST MID-WEEK...IF NOT LONGER. THE MORNING HIGH TIDE CYCLE APPEARS TO BE THE GREATER OF THE TWO...AND THERE IS INCREASING CONCERN THAT MAJOR COASTAL FLOODING COULD BE AN ISSUE WEDNESDAY AND POSSIBLY THURSDAY MORNING GIVEN STRONG NORTHEAST WINDS JUST OFFSHORE. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WARNING FROM 1 AM TO 9 AM EST TUESDAY FOR GAZ087-088- 099>101-114>116-118-137-138. FROST ADVISORY FROM 4 AM TO 9 AM EST TUESDAY FOR GAZ140. SC...FREEZE WARNING FROM 1 AM TO 9 AM EST TUESDAY FOR SCZ040- 042>045-047>052. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ374. && $$ ST
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
310 PM CST MON NOV 23 2015 .SHORT TERM...(Tonight) ISSUED AT 310 PM CST MON NOV 23 2015 Main short-term forecast concern continues to be potential for fog development tonight as high pressure slides overhead and winds go light/variable. Several factors point to at least patchy fog, including nearly calm winds after sunset and increasing boundary layer moisture due to snow melt. However, the possible fly-in-the- ointment will be increasing high clouds currently seen on visible satellite imagery streaming from the Dakotas into Iowa. All models suggest these clouds will spread into Illinois late this afternoon then persist through much of the night. Whether they will be thick enough to limit radiational cooling and prevent widespread fog is still in question. Several models such as the NAM and GFS indicate little or no restriction to visby tonight, while the HRRR is showing fog developing from mid-evening through the overnight hours. At this point, will mention patchy fog over the snow cover, generally along/north of the I-74 corridor. Overnight lows will be in the middle to upper 20s. && .LONG TERM...(Tuesday through Monday) ISSUED AT 310 PM CST MON NOV 23 2015 Upper level ridging will build into central IL Tuesday providing for dry conditions with some mid and high cloud cover. The warming trend will continue slowly with highs reaching the low to mid 40s I-74 northward where snow cover remains...to the low to mid 50s south of I-70. Lows Tuesday night should drop to only the mid to upper 30s as increased winds and cloud cover prevent further cooling at the surface. By Wednesday...this ridge will slip east of IL allowing increased southerly flow and a plume of Gulf moisture to nudge eastward into Illinois. The result will be a continued warming trend with highs reaching around 50 north of I-74 to the upper 50s from I-70 southward. Chances for precipitation will be arriving in western portions of the state by evening. 12Z models currently keep this precipitation light until Thursday/Thanksgiving evening...then spread heavier amounts around 0.50 inches per 6 hours across the state from Thursday afternoon through Friday morning. Total rainfall amounts look to be around 1 to 1.25 inches southeast of Champaign- Decatur, and 1.5 to 1.75 inches to the northwest. Could see a mix of light snow with the light rain over central IL Friday night before ending. Highs Thursday should be in the mid 50s to around 60, cooling to the low to mid 40s over the IL river valley to the mid to upper 50s in southeast IL. High pressure will build into the Midwest region on Saturday for a good chance for dry conditions, although GFS is quicker returning moisture back into central IL and perhaps some precipitation will return Saturday night into Sunday if this turns out. Chance for precipitation with this next system looks to linger through Monday. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) ISSUED AT 1150 AM CST MON NOV 23 2015 Main aviation forecast concern continues to be potential for fog development tonight as high pressure slides overhead and winds go light/variable. Several factors point to at least patchy fog, including nearly calm winds after sunset and increasing boundary layer moisture due to snow melt. However, the possible fly-in- the-ointment will be increasing high clouds currently seen on visible satellite imagery streaming from the Dakotas into Iowa. All models suggest these clouds will spread into Illinois late this afternoon then persist through much of the night. Whether they will be thick enough to limit radiational cooling and prevent widespread fog is still in question. Several models such as the NAM and GFS indicate little or no restriction to visby tonight, while the HRRR is showing fog developing from mid-evening through the overnight hours. At this point, will continue to feature visbys down to around 3SM tonight where snow cover exists at the I-74 terminals, but will maintain unrestricted visbys at both KSPI and KDEC. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Barnes LONG TERM...Onton AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1150 AM CST MON NOV 23 2015 .UPDATE... ISSUED AT 950 AM CST MON NOV 23 2015 High pressure over the Deep South is providing a mild southwesterly flow across central Illinois this morning. Thanks to abundant sunshine, 15z/9am temperatures have already risen into the upper 30s and lower 40s across areas without a snow cover. Further north over the deeper snow field, readings remain in the lower 30s along/north of I-74. With only a few high/thin clouds expected to stream into the area this afternoon, am expecting nearly full sunshine and continued southwesterly winds. Based on current rate of temp rise, have adjusted afternoon highs up a few degrees across the southern two-thirds of the KILX CWA. Highs will range from the upper 30s from Galesburg to Lacon...to around 50 degrees along/southwest of a Jacksonville to Flora line. && .SHORT TERM...(Today) ISSUED AT 330 AM CST MON NOV 23 2015 A weak sfc trough will move through the CWA this morning, switching southerly winds to westerly. Pressure gradient is currently tighter ahead of this trough so winds this morning will be higher than this afternoon, after the trough passes through and sfc ridging begins to build into the area. Satellite trends indicate lots of clear skies over the area for the day. Will see some warmer temps today, which will melt some of the snow, but without any good waa on the sfc and still fairly good snow pack in the north and northeast, the warmer temps will be limited to mostly areas south of I-74. Temps over the snow pack should still be above freezing, but overall below normal temps expected today. .LONG TERM...(Tonight through Sunday) ISSUED AT 330 AM CST MON NOV 23 2015 Surface high pressure ridge settling into the southeast states tonight and ridging nw into central IL will bring lighter winds to the area tonight. These lighter winds along with boundary layer moisture from snow melt will likely develop patchy fog over snow pack of northern CWA later tonight into mid morning Tue. Models continue to show streaks of mid/high clouds affecting central and especially ne CWA tonight with weak upper level disturbances in wnw flow. Main over level trof and short wave energy will be ne of IL over the Great Lakes region where more cloud cover expected. Lows tonight range from lower 20s north of Peoria to upper 20s sw CWA. 00Z models continue to show upper level ridge building into IL and the ohio river valley Tue/Wed. Meanwhile surface high pressure strengths as it moves into the mid Atlantic states and New England Tue night into Wed. Increasing pressure gradient over IL Tue/Wed to bring breezier south winds along with milder temperatures by Wed. Highs Tue range from lower 40s from I-74 ne where lingering snow pack to lower 50s sw CWA. Southeast winds of 8-15 mph on Tuesday. Added patchy fog to northern CWA overnight Tue night until mid morning Wed where more moisture from snow melt. Lows Tue night in the low to mid 30s, with upper 30s from Springfield and Jacksonville sw. Strong cutoff upper level low/trof digging into northern CA by 12Z/Wed and moving into the central Rockies on Thanksgiving Day. Increasing WAA and moisture well ahead of this storm system possibly getting rain showers into the IL river valley later Wed and Wed evening. Shower chances increase from nw to se overnight Wed night into Thursday. Southeast IL likely to stay dry Wed night and into Thu. Milder highs Wed near 50F from I-74 ne to mid 50s sw CWA and in southeast IL. Highs Thu in the upper 50s to near 60F. Highest chances of rain appears to be over the IL river valley Thu and across the area Thu night and east of the IL river Friday. Better chance of isolated thunderstorms appears to be sw of central IL Thu and Thu night. But heavier rains of 1-1.5 inches with locally higher amounts before diminishing from nw to se during Friday night. Could see a mix of light snow with the light rain over central IL Friday night especially overnight before ending. Highs Fri range from low to mid 40s over IL river valley to the mid to upper 50s in southeast IL. High pressure builds into the Great Lakes region on Saturday and Saturday night bringing cooler temperatures to IL along with drier conditions. Lingered slight chances of light rain/snow over far southern 6 counties closer to cold front pressing southward into the TN river valley. GFS is quicker returning moisture back into central IL Sunday while ECMWF model waits until Sunday night to bring back precipitation. Will stay close to superblend pops for now that far out. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) ISSUED AT 1150 AM CST MON NOV 23 2015 Main aviation forecast concern continues to be potential for fog development tonight as high pressure slides overhead and winds go light/variable. Several factors point to at least patchy fog, including nearly calm winds after sunset and increasing boundary layer moisture due to snow melt. However, the possible fly-in- the-ointment will be increasing high clouds currently seen on visible satellite imagery streaming from the Dakotas into Iowa. All models suggest these clouds will spread into Illinois late this afternoon then persist through much of the night. Whether they will be thick enough to limit radiational cooling and prevent widespread fog is still in question. Several models such as the NAM and GFS indicate little or no restriction to visby tonight, while the HRRR is showing fog developing from mid-evening through the overnight hours. At this point, will continue to feature visbys down to around 3SM tonight where snow cover exists at the I-74 terminals, but will maintain unrestricted visbys at both KSPI and KDEC. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Barnes SHORT TERM...Auten LONG TERM...07 AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1220 PM EST MON NOV 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM EST MON NOV 23 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF EXTENDING S THRU THE GREAT LAKES REGION. SHEARED OUT SHORTWAVE/LEFT EXIT OF 120+KT UPPER JET EXTENDING FROM SASKATCHEWAN INTO THE UPPER MISSISSIPPI VALLEY HAS GENERATED SOME AREAS OF -SN INTO WRN UPPER MI OVERNIGHT. MODELS OVER THE LAST DAY OF RUNS CORRECTLY TRENDED LIGHTER WITH THIS PCPN AS SNOW THAT HAS OCCURRED HAS BEEN VERY LIGHT WITH NOT MUCH MORE THAN A DUSTING OF ACCUMULATION WHERE SNOW HAS FALLEN PER WEBCAMS. TO THE E...JUST AS SOME HIGH RES MODELS WERE INDICATING 24 HRS AGO...THE REGIONAL CANADIAN IN PARTICULAR...A BURST OF HVY SNOW MOVED N OFF NRN LAKE MI INTO PARTS OF THE ERN U.P. OVER THE LAST SEVERAL HRS. IT APPEARS THE EXTREME SE CORNER OF LUCE COUNTY PROBABLY SAW A VERY BRIEF PERIOD OF MDT TO HVY SNOW AROUND 06Z. THAT AREA OF MDT/HVY SNOW HAS SHIFTED E INTO THE STRAITS VCNTY SINCE THEN. THERE IS STILL SOME CONCERN FOR LAKE ENHANCED SNOW OFF NRN LAKE MI TO SHIFT/REFORM BACK TO THE W TODAY. ON THE HIGH EXTREME IS THE REGIONAL CANADIAN WHICH GENERATES 0.3 INCHES OF QPF IN THE FAR SE CORNER OF LUCE COUNTY BTWN 15Z AND 00Z. SINCE THE MAJORITY OF AVBL HIGH RES GUIDANCE...INCLUDING THE HIGH RES CANADIAN...KEEPS THE BULK OF REDEVELOPING LAKE ENHANCED SNOW JUST E OF LUCE COUNTY...WILL KEEP SNOW AMOUNTS UNDER ADVY CRITERIA WITH PERHAPS 1.5-2 INCHES TO THE SE OF KERY. ELSEWHERE....PATCHY -SN MOVING ACROSS WRN UPPER MI ATTM SHOULD DISSIPATE OVER THE NEXT SEVERAL HRS AS IT SHIFTS E AND HAS TO OVERCOME INITIAL DRY LOWER LEVEL AIR. THEN...A SFC LOW PRES TROF WILL SWING INTO WRN UPPER MI LATE MORNING/AFTN...BRINGING A WIND SHIFT TO THE W TO NW. EXPECT -SHSN TO ACCOMPANY THE TROF AS OVERLAKE INSTABILITY WITH 850MB TEMPS AROUND -7C WILL BE MORE THAN SUFFICIENT TO GENERATE -SHSN ALONG THE TROF/CONVERGENCE ZONE AS IT CROSSES WRN LAKE SUPERIOR. THIS WILL THEN TRANSITION TO SCT LAKE EFFECT -SHSN INTO TONIGHT FOR AREAS FAVORED BY NW WINDS AS 850MB TEMPS DROP A DEGREE OR TWO C. INITIALLY...INVERSION IS UP AROUND 7KFT THIS EVENING...BUT FALLS TO AROUND 4KFT W OVERNIGHT AND TO AROUND 5KFT E LATE. DESPITE THE DECENTLY HIGH INVERSION HEIGHTS...SNOW ACCUMULATIONS WILL BE LIMITED DUE TO THE DGZ BEING ABOVE THE CONVECTIVE LAYER. AT THIS POINT...EXPECT ACCUMULATIONS MOSTLY UNDER 1 INCH...BUT IF ANY RELATIVELY STATIONARY BANDS SET UP...THERE CERTAINLY COULD BE ISOLATED 2-3 INCH AMOUNTS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 422 AM EST MON NOV 23 2015 ...RAIN CHANGING TO SNOW WED NIGHT INTO THANKSGIVING DAY WITH ACCUMULATING SNOW POSSIBLE INTO THU NIGHT... IN LARGER SCALE...DEEP TROUGH OVER EASTERN CONUS SLIDES TO EASTERN CANADA ON TUE WHILE SPLIT FLOW TROUGHING DEVELOPS WESTERN CANADA TO WESTERN CONUS. 1000-850MB TROUGH FORMING ON TUE OVER ROCKIES AND ADJACENT PLAINS AND LOW-LEVEL HIGH PRESSURE SETTLING TO SOUTHEAST CONUS WILL ALLOW S/SE WINDS AT SFC TO BRING INCREASING MOISTURE OFF THE GULF OF MEXICO TOWARD THE MIDDLE MISSISSIPPI RIVER VALLEY. WILL STAY DRY OVER UPR LAKES ON TUE BUT LATE TUE NIGHT INTO WED MORNING SOUNDINGS SHOW INCREASING MOISTURE BLO H9 INTO UPPER GREAT LAKES. IF THERE IS ANY PRECIP AROUND ON WED MORNING...IT LIKELY WOULD TAKE FORM OF DZ/FZDZ DEPENDING ON SFC TEMPS. BEST CHANCE FOR LIGHT ICING WOULD BE OVER INTERIOR CNTRL CWA FM IRON/DICKINSON INTO BARAGA AND WESTERN MARQUETTE COUNTY. MODELS SOMETIMES ARE TOO OVERDONE ON THIS TYPE OF LOW-LEVEL MOISTENING BUT IN THIS CASE THERE IS DECENT SNOW PACK JUST TO THE SOUTH SO THAT MAY HELP THE EXPANSION OF LOW-LEVEL MOISTURE. LATER ON WEDNESDAY DEEPER MOISTURE AND LARGER SCALE FORCING INCREASE STEADILY AHEAD OF SHORTWAVE TROUGH SLIDING OVER MANTIOBA AND NORTHERN ONTARIO. LOW-LEVEL THETA-E ADVECTION INCREASES BRIEFLY BEFORE BEING SHUNTED TO THE SOUTH AND EAST ON WED NIGHT. SHOULD SEE LIGHT RAIN BECOME MORE WIDESPREAD...BUT WITHOUT MUCH OF STRONG MOISTURE TAP AHEAD OF THE TROUGH WITH THE NORTHERN STREAM SHORTWAVE TROUGH...RAINFALL AMOUNTS SHOULD BE LIGHT. COOLER AIR WITH H85 TEMPS DOWN BLO -2C SLIDES IN AFTER MIDNIGHT WED NIGHT OVER THE WEST AND THAT SHOULD TURN ANY LINGERING RAIN TO SNOW. GFS SOUNDINGS AND H85- H7 RH FIELDS FM THE ECMWF INDICATE MID-LEVEL DRYING MAY LEAD TO CHANCES OF FREEZING DRIZZLE OR DRIZZLE INSTEAD OF SNOW LATE WED NIGHT INTO THANKSGIVING MORNING WITH MOIST LAYER AT TEMPS BLO 0C BUT MUCH WARMER THAN -10C. UPSLOPE FLOW OFF LK SUPERIOR WOULD ALSO AID IN LOW-LEVEL LIFT AND MAYBE LEAD TO GREATER CHANCES OF DRIZZLE FOR WEST AND NCNTRL UPR MICHIGAN. ADDED MENTION OF DZ/FZDZ IN THE GRIDS FOR THESE AREAS. ATTN LATER ON THANKSGIVING TURNS TO WAVE OF LOW PRESSURE THAT RIDES NORTHEAST ALONG THE TROUGH OVER THE UPR GREAT LAKES. 00Z ECMWF TRENDED FARTHER WEST WITH THE WAVE WHILE THE GFS TRENDED FARTHER EAST. IF THE ECMWF IS CORRECT SWATH OF MODERATE PRECIP WOULD LIFT BACK OVER AT LEAST THE SOUTH AND EAST CWA THANKSGIVING AFTN INTO THU NIGHT. SINCE THE INITIAL TROUGH/COLD FRONT IS THROUGH MOST CWA PTYPE WOULD MOSTLY BE SNOW...EXCEPT OVER FAR SCNTRL WHERE WARM AIR LINGERS AS EVEN ECMWF SHOWS H85 TEMPS AT LEAST +1C WHEN HEAVIER QPF IS FORECAST TO MOVE THROUGH. SFC TEMPS STILL MID 30S AS WELL SO NO RISK OF ANY FREEZING PRECIP EITHER. JUST INLAND OVER SOUTH CENTRAL AND OVER MOST OF THE EASTERN CWA /N WINDS LEADING TO OFFSHORE WINDS AT ESC AND ISQ/ COULD SEE SEVERAL INCHES OF WET SNOW WITH THE ECMWF SOLN AS 12 HR QPF BTWN 18Z THU AND 06Z FRI IS AT LEAST 0.5 IF NOT UP TO 0.75 INCH. MEANWHILE...LATEST GFS BARELY IS OVER 0.25 INCHES FOR THAT TIME FRAME. GEM IS MORE LIKE THE ECMWF WITH TOTAL QPF...BUT MUCH WARMER AND WOULD RESULT IN MOSTLY RAIN FOR THOSE AREAS. WPC PREFERRED CONSENSUS OF GFS/ECMWF/GEM. WILL CONTINUE TO MENTION THE RAIN TO SNOW AND SOME ACCUMULATING SNOW IN THE HWO...BUT CANNOT PLAY UP THE SNOW TOO MUCH OR GET TOO SPECIFIC YET GIVEN THE UNCERTAINTIES THAT REMAIN. BEHIND THIS SYSTEM...TURNS COLD ENOUGH FOR LAKE EFFECT SNOW SHOWERS OFF LK SUPERIOR FRI INTO FRI NIGHT. ON FRI...AREAS FAVORED BY N WINDS MAY SEE SOME SNOW FOR A CHANGE...THEN WOULD BE MAINLY NW FLOW AREAS FRI NIGHT. DRY LOW-LEVEL AIRMASS WITH STRONG HIGH BUILDING IN SHOULD LIMIT EXTENT OF LES. BASED ON CURRENT MODEL SOLUTIONS IT IS DOUBTFUL AMOUNTS WOULD REACH ADVY LEVELS FRI-FRI NIGHT. SLIGHT WARMING TREND WITH GENERALLY DRY WEATHER IS EXPECTED FOR NEXT WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1220 PM EST MON NOV 23 2015 WITH THE PASSAGE OF A SFC TROF...LAKE EFFECT -SHSN WILL DEVELOP FOR AREAS FAVORED BY NW WINDS THIS AFTN AND TONIGHT. FOR KCMX/KIWD...THIS MEANS MVFR CONDITIONS SHOULD PREVAIL THRU THE FCST PERIOD. AT KSAW...VFR CONDITIONS SHOULD CONTINUE INTO THE MID AFTN WITH A DOWNSLOPE WESTERLY WIND. MVFR CONDITIONS SHOULD THEN DEVELOP AT KSAW LATE AFTN AND CONTINUE THRU TUE MORNING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 450 AM EST MON NOV 23 2015 NO GALES ARE EXPECTED ON LAKE SUPERIOR THRU THE END OF THE WEEK. PREVIOUSLY...THERE WERE INDICATIONS OF A GALE EVENT THU NIGHT/FRI AFTER A COLD FRONT PASSES. HOWEVER...IT NOW APPEARS THAT THE FRONT WILL BE WEAKER SO THAT WINDS WILL REMAIN BLO GALE FORCE. LIGHTEST WINDS THIS WEEK WILL OCCUR TUE AS A HIGH PRES RIDGE QUICKLY SHIFTS ACROSS THE UPPER GREAT LAKES. STRONGEST WINDS THIS WEEK WILL OCCUR LATE TUE NIGHT/WED OVER THE E HALF OF LAKE SUPERIOR IN THE SOUTHERLY FLOW AHEAD OF THE AFOREMENTIONED COLD FRONT AND THEN LATE THU/FRI AFTER THE FRONT PASSES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
240 PM CST MON NOV 23 2015 .SYNOPSIS... ISSUED AT 239 PM CST MON NOV 23 2015 BROAD NWRLY FLOW ALOFT FORMED BY A SLOWLY EXITING LONG WAVE TROUGH ACROSS THE EASTERN STATES AND BROAD...WEAK RIDGING IN THE WEST. OFF THE BC COAST...A DEVELOPING LONG WAVE TROUGH WHICH WILL BE SLIDING EWD TO THE WEST COAST. LEAD SHORT WAVE/PV ANOMALY MOVING ONTO THE CENTRAL CA COAST CURRENTLY PRODUCING BAROCLINIC LEAF OVER NV. CLOSER TO HOME...SATELLITE IMAGERY SHOWING SNOW FIELD ACROSS PORTIONS OF NC NEB CONTINUING TO ERRODE SLOWLY AS TEMPS WARM QUICKLY UNDER MOSTLY FULL SUNSHINE AND DESPITE LIGHT WIND. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 239 PM CST MON NOV 23 2015 BIGGEST CONCERN OVERNIGHT IS THE POTENTIAL FOR FOG/LOW CLOUDS IN PORTIONS OF THE NC FCST AREA. NAM/SREF HAVE BEEN CONSISTENT AT SUGGESTING THIS AND NAM BUFR SOUNDINGS SHOW A LAYER OF TRAPPED COLD AIR FROM THE SFC TO ABOUT 600 FT. NAM HAS ISSUES WITH LOWER LAYER IN AND NEAR SNOW COVER...BUT COULD STILL BE SUGGESTING A REALISTIC POTENTIAL. SREF VSBY PROBS SHOW GOOD POTENTIAL FOR REDUCED VSBY IN THE 06-12Z TUES TIME FRAME. MEANWHILE THE RAP BUFR SOUNDINGS ARE NOT SHOWING THIS AND GFS LAMP GUIDANCE HAS BACKED OFF. FROM AN OBSERVATIONAL PERSPECTIVE LIGHT SOUTHEASTERLY WINDS OVERNIGHT IN CONCERT WITH ANY RESIDUAL MOISTURE FROM MELTING SNOW WOULD SUGGEST NAM COULD BE ON TO SOMETHING. HAVE ADDED PATCHY FOG TO THE FCST THOUGH WILL HAVE TO MONITOR FOR MORE STRONGER WORDING IF DEVELOPMENT DOES OCCUR. PREVIOUSLY MENTIONED LEAD SHORT WAVE WILL PIVOT NEWD INTO THE HIGH PLAINS DURING THE DAY TUES. ASSOCIATED HEIGHT FALLS WILL SERVE TO KICK THE PREVIOUSLY DEVELOPED SFC TROUGH EWD DURING THE DAY WHICH...BECAUSE OF DRY LOWER LEVELS...SHOULD ONLY RESULT IN A WIND SHIFT FROM SERLY TO SRLY OR SWRLY BEHIND SFC TROUGH. WEAK LARGE SCALE LIFT WILL TEMPER HIGHS A BIT TMRW...BUT BY LATE IN THE DAY SUBSIDENCE BECOMES RE-ESTABLISHED AND WOULD EXPECT TEMPS TO RETURN TO ABOVE NORMAL VALUES AGAIN. HAVE TRENDED FCST TWD THE HIGH END OF THE ENVELOPE OF POSSIBILITIES AS A RESULT AND ALSO BECAUSE TEMPS HAVE WARMED ABOVE EXPECTTED LEVELS THE LAST TWO DAYS. TEMPS WILL CONTINUE TO BE HELD DOWN WHERE SNOW COVER STILL REMAINS IN NC NEB AND ALSO IF CLOUDS DO FORM THEY WILL INHIBIT INSOLATION DURING THE MORNING HOURS. OTHERWISE LITTLE IN THE WAY OF FCST CONCERNS FOR TUES. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 239 PM CST MON NOV 23 2015 SOUTHERLY LOW LEVEL FLOW WILL BEGIN TO DRAW MOISTURE NORTHWARD INTO THE CENTRAL PLAINS TUESDAY NIGHT. MODELS INDICATE THAT STRATUS WILL DEVELOP AND SPREAD NORTHWARD TUESDAY NIGHT. RIGHT NOW IT APPEARS THAT MOST OF THAT WILL BE DIRECTED TOWARD CENTRAL AND EASTERN NEBRASKA...BUT MAY CLIP THE VERY FAR EASTERN PORTIONS OF THE AREA. HAVE INTRODUCED PATCHY FOG INTO THE SRN ZONES LATE TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING. AN ARCTIC COLD FRONT WILL SWEEP SOUTH THROUGH THE AREA WEDNESDAY. AT THE SAME TIME A LEAD WAVE WILL BEGIN TO EJECT EASTWARD FROM THE WESTERN CONUS UPPER LOW. EXPECT FALLING TEMPERATURES WEDNESDAY AFTERNOON AS THE COLD FRONT PASSES AS WELL AS AN INCREASE IN MID AND UPPER LEVEL CLOUDS. MAY NOT SEE THE HIGHER CLOUDS HOWEVER...AS LOW STRATUS CLOUDS WILL QUICKLY INCREASE/DEVELOP SOUTHWARD BEHIND THE FRONT. ARCTIC AIR WILL BE FILTERING SOUTH THROUGH THE AREA WEDNESDAY NIGHT BEHIND THE COLD FRONT. A PERIOD OF LIGHT DRIZZLE AND FREEZING DRIZZLE DURING THE EVENING TO FREEZING DRIZZLE/SNOW AFTER MIDNIGHT. NAM BUFKIT SOUNDING INDICATE A FREEZING DRIZZLE SOUNDING...WHILE THE GFS KEEPS THE LOWEST LEVELS DRIER. WITH CONSIDERABLE DRY AIR ALOFT NOT SURE WE WILL SEE MUCH SNOW. MAY BE MORE FREEZING DRIZZLE. THE LEAD WAVE WILL CROSS THE CENTRAL AND SOUTHERN PLAINS THANKSGIVING. MOST OF THE PRECIPITATION WILL REMAIN EAST AND SOUTHEAST OF THE IMMEDIATE AREA...BUT SOME VERY LIGHT SNOW IS POSSIBLE WITH ACCUMULATIONS EXPECTED TO REMAIN A DUSTING. NOT MUCH CHANGE TO HIGHS WITH MID TO UPPER 20S FCST. NORTH TO NORTHEAST WINDS 10 TO 20 MPH HOWEVER WILL GIVE WIND CHILLS IN THE TEENS. FOR THE WEEKEND...PARTICULARLY SATURDAY INTO MONDAY...OPERATIONAL MODELS EJECT THE LARGE UPPER LEVEL TROUGH EASTWARD INTO THE CENTRAL PLAINS. PLENTY OF QUESTIONS REGARDING TIMING. FOR NOW WILL CARRY A SLIGHT TO LOW CHANCE POP FOR SNOW SATURDAY INTO MONDAY. OTHERWISE CONTINUED COLD WITH BELOW NORMAL TEMPERATURES IN THE MID 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1130 AM CST MON NOV 23 2015 VFR CONDITIONS THROUGH THE FIRST PART OF THE FCST BUT SOME CONCERN FOR VSBY RESTRICTIONS AND IFR CIGS LATE TONIGHT AT KVTN. TRANSITORY RIDGING ALOFT WILL MOVE ACROSS THE PLAINS AS LONG WAVE TROUGH OVER THE EAST MOVES OUT. THE RESULT WILL BE A MORE ZONAL FLOW ALOFT WHICH WILL SERVE TO DEVELOP LOW PRESSURE ALONG THE LEE OF THE ROCKIES. SFC RESULT IS A WEAK FRONTAL BOUNDARY RETREATING EWD AS WARM AIR DESCENDS FROM THE WEST. SOME MID/HIGH CLOUDS RESULTING FROM THE ISENTROPIC LIFT THIS AFTERNOON PUSHING EWD. THIS WILL SETUP A FAVORABLE PATTERN TONIGHT FOR LOW CLOUDS AND FOG...WHICH THE NAM AND THE 23.09Z SREF PICK UP ON. SKEPTICAL OF THE NAM DUE ITS TENDENCY TO NOT MIX THE LOW LAYERS ENOUGH DURING THE DAY AND DEVELOP TOO MUCH COLD AIR NEAR THE SFC AT NIGHT. BUT...SINCE THIS IS A PATTERN FAVORABLE HAVE TRENDED THE FCST FOR KVTN IN THAT MANNER THOUGH CONFIDENCE IS ONLY MEDIUM AT THIS POINT. NO RESTRICTIONS IN THE FCST AT THIS TIME FOR KLBF. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STOPPKOTTE SHORT TERM...STOPPKOTTE LONG TERM...ROBERG AVIATION...STOPPKOTTE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1259 PM CST MON NOV 23 2015 .UPDATE... ISSUED AT 1256 PM CST MON NOV 23 2015 FOR THE EARLY AFTERNOON UPDATE BUMPED TEMPERATURES UP A FEW DEGREES MOST AREAS. DID TEMPER HIGHS A LITTLE OVER THE FAR SOUTHWEST WHERE PERSISTENT MID AND HIGH LEVEL CLOUDS REMAIN. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. UPDATE ISSUED AT 959 AM CST MON NOV 23 2015 HIGH PRESSURE WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA TODAY. HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE FROM WEST TO EAST. SOME MID LEVEL WARM ADVECTION CLOUDINESS SPREADING FROM EASTERN MONTANA INTO SOUTHWEST NORTH DAKOTA TODAY COULD PRODUCE A FEW FLURRIES...BUT NOT WORTH A MENTION AT THIS TIME. ADJUSTED CLOUDS HIGHER WEST AND LOWER EAST THROUGH THE MORNING. TEMPERATURES LOOK REASONABLE AND NO ADJUSTMENTS OTHER THAN POPULATING THE LATEST OBSERVATIONS. UPDATE ISSUED AT 635 AM CST MON NOV 23 2015 NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE CYCLE OTHER THAN BLENDING RECENT OBSERVATIONS WITH SHORT TERM MODEL GUIDANCE. RADAR ECHOES IN NORTHEASTERN MT REFLECT AN INCREASE IN MIDDLE- AND HIGH- LEVEL CLOUDS AND NOT PRECIPITATION DUE TO A DRY LOWER ATMOSPHERE. THAT SCENARIO IS WELL-REFLECTED BY RECENT HRRR ITERATIONS AND THUS THE DRY FORECAST FOR TODAY APPEARS TO BE WELL IN HAND. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CST MON NOV 23 2015 QUIET WEATHER HIGHLIGHTS THE SHORT TERM PERIOD. CURRENTLY...THE STRONG LOW PRESSURE SYSTEM ASSOCIATED WITH YESTERDAY`S WINDY CONDITIONS WAS CENTERED OVER THE BORDER OF MANITOBA/ONTARIO/MINNESOTA. A WEAK HIGH PRESSURE AXIS EXTENDED FROM SOUTHERN ALBERTA SOUTHEASTWARD INTO EASTERN MONTANA AND THE WESTERN DAKOTAS...WITH BROAD LOW PRESSURE DEVELOPING IN THE LEE OF THE ROCKIES. TODAY THE STRONG LOW PRESSURE SYSTEM IS FORECAST TO MOVE EAST TOWARDS THE GREAT LAKES AND HUDSON BAY...AND THE SURFACE HIGH PRESSURE RIDGE AXIS MOVES EASTWARD INTO THE CENTRAL AND EASTERN DAKOTAS AS AN UPPER LEVEL RIDGE BUILDS/EXPANDS FROM THE ROCKIES INTO THE WESTERN PLAINS. MAINLY PARTLY CLOUDY SKIES TODAY WITH MIDDLE/HIGH CLOUDS MOVING EAST INTO NORTH DAKOTA. WARMER AIR IN SOUTHWESTERN NORTH DAKOTA WITH HIGHS IN THE LOWER 40S...WITH COOLER AIR TO THE NORTHEAST WITH HIGHS IN THE MID TO UPPER 30S. TONIGHT THE BROAD UPPER LEVEL RIDGE MIGRATES EASTWARD AND THE FLOW OVER THE ROCKIES BECOMES SOUTHWESTERLY ALOFT. IN RESPONSE...BROAD SURFACE LOW PRESSURE DEVELOPS OVER THE ROCKIES AND FRONT RANGE...AND A LONG BROAD FETCH OF SOUTHERLY SURFACE WINDS DEVELOPS FROM THE SOUTHERN PLAINS NORTHWARD INTO THE NORTHERN PLAINS. A LOW LEVEL JET DEVELOPS...AND THIS WILL ALLOW LOW LEVEL MOISTURE TO STREAM NORTHWARD INTO SOUTH CENTRAL CANADA. LOOK FOR INCREASING LOW CLOUDS WITH SOUTHEASTERLY SURFACE WINDS...AND INCREASING MID LEVEL CLOUDS MOVING IN FROM THE WEST/SOUTHWEST. LOW TEMPERATURES ARE EXPECTED TO BE IN THE 20S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 337 AM CST MON NOV 23 2015 THE FOCUS IN THE LONG TERM IS ON LIGHT SNOW POTENTIAL CENTERED ON WEDNESDAY. WE ARE BECOMING MORE CONFIDENT THAT ACCUMULATIONS WILL BE RELATIVELY LOW WITH THIS EVENT...POTENTIALLY LIMITING IMPACTS. THE 00 UTC MODEL SUITE WAS IN RELATIVELY GOOD AGREEMENT IN SHOWING LIGHT SNOW DEVELOPING IN WESTERN ND BY EARLY WEDNESDAY MORNING AND SPREADING EASTWARD DURING THE DAY. THE MULTI-MODEL CONSENSUS CALLS FOR LIQUID-EQUIVALENT MOISTURE VALUES OF 0.05 TO 0.15 INCHES /MOST IN FAR SOUTHWESTERN ND/...WHICH SHOULD CONTRIBUTE TO SNOW AMOUNTS RANGING FROM LESS THAN ONE-HALF INCH TO THE NORTH AND EAST OF THE MISSOURI RIVER...TO 1 TO 2 INCHES SOUTH AND WEST OF THE MISSOURI RIVER. OUR OFFICIAL FORECAST PRODUCED 3 INCH SNOW TOTALS ONLY IN EXTREME SOUTHWESTERN ND...BOWMAN AND SLOPE COUNTIES...WEDNESDAY THROUGH WEDNESDAY NIGHT. THE SNOW WILL BE GENERATED IN A POST-FRONTAL ENVIRONMENT...DRIVEN MAINLY BY DYNAMICS ASSOCIATED WITH A SHORTWAVE TROUGH EMBEDDED IN THE NORTHERN STREAM OF A SPLIT FLOW. THE 03 UTC SREF LINGERED THE SNOW LONGER THAN THE 00 UTC DETERMINISTIC GUIDANCE...SO A BIT OF UNCERTAINTY REMAINS...BUT IN GENERAL GUIDANCE CONTINUED TO SUGGEST THAT THE PRIMARY VERTICAL MOTION ASSOCIATED WITH THE 500-MB LOW IN THE GREAT BASIN WILL REMAIN DISPLACED SOUTH OF ND. IF THAT IS THE CASE...THANKSGIVING DAY MAY END UP COLD...BUT DRY IN MOST AREAS. ONE OTHER ISSUE WE WILL NEED TO CONSIDER IS WHETHER FOG DEVELOPS TUESDAY NIGHT...AND WHETHER LINGERING WARM AND DRY AIR ALOFT IS CAPABLE OF PRODUCING ANY LIGHT FREEZING RAIN OR LIGHT FREEZING DRIZZLE TUESDAY NIGHT INTO WEDNESDAY MORNING. FORECAST SOUNDINGS ARE NOT PARTICULARLY SUGGESTIVE OF THAT POTENTIAL THOUGH...SO WE ARE NOT MESSAGING THAT RISK AT THIS POINT. A REX BLOCK WILL DEVELOP ALOFT OVER THE WESTERN UNITED STATES BY NEXT WEEKEND AS THE GREAT BASIN LOW GETS PINCHED OFF TO THE SOUTH OF A DEVELOPING 500-MB RIDGE OVER WESTERN CANADA. THIS SCENARIO IS EXPECTED TO GENERATE A WARMING TREND AND MAINLY DRY WEATHER ACROSS THE AREA NEXT WEEKEND...THOUGH THE 00 UTC GFS /AND THE 00 UTC GFS ALONE/ DOES SUGGEST SOME SNOW POTENTIAL RETURNING NEXT SUNDAY WHEN IT BREAKS THE BLOCK DOWN AND KICKS THE REMNANT LOW ALOFT EASTWARD FURTHER NORTH THAN THE REST OF THE 00 UTC MODEL GUIDANCE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1256 PM CST MON NOV 23 2015 A BAND OF MID TO HIGH LEVEL CLOUDS WILL MOVE ACROSS NORTH DAKOTA MONDAY AFTERNOON AND EVENING...FROM THE SOUTHWEST TO NORTHEAST. AS WE APPROACH THE OVERNIGHT HOURS...LOWER LEVEL MOISTURE WILL INCREASE...BRINGING MVFR CEILINGS TO KDIK...AND POSSIBLY TO ALL OTHER SITES. MORE UNCERTAINTY REGARDING LOWER CEILINGS EXIST ACROSS THESE OTHER SITES...SO MODEL TRENDS WILL HAVE TO BE MONITORED CLOSELY. FOR NOW WILL JUST KEEP SCATTERED LOWER CLOUDS IN THE FORECAST FOR KISN/KMOT/KBIS/KJMS. VARIABLE LIGHT WINDS WILL PREVAIL ACROSS ALL SITES THROUGH THE PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...JV LONG TERM...CJS AVIATION...ZH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1005 AM CST MON NOV 23 2015 .UPDATE... ISSUED AT 959 AM CST MON NOV 23 2015 HIGH PRESSURE WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA TODAY. HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE FROM WEST TO EAST. SOME MID LEVEL WARM ADVECTION CLOUDINESS SPREADING FROM EASTERN MONTANA INTO SOUTHWEST NORTH DAKOTA TODAY COULD PRODUCE A FEW FLURRIES...BUT NOT WORTH A MENTION AT THIS TIME. ADJUSTED CLOUDS HIGHER WEST AND LOWER EAST THROUGH THE MORNING. TEMPERATURES LOOK REASONABLE AND NO ADJUSTMENTS OTHER THAN POPULATING THE LATEST OBSERVATIONS. UPDATE ISSUED AT 635 AM CST MON NOV 23 2015 NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE CYCLE OTHER THAN BLENDING RECENT OBSERVATIONS WITH SHORT TERM MODEL GUIDANCE. RADAR ECHOES IN NORTHEASTERN MT REFLECT AN INCREASE IN MIDDLE- AND HIGH- LEVEL CLOUDS AND NOT PRECIPITATION DUE TO A DRY LOWER ATMOSPHERE. THAT SCENARIO IS WELL-REFLECTED BY RECENT HRRR ITERATIONS AND THUS THE DRY FORECAST FOR TODAY APPEARS TO BE WELL IN HAND. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CST MON NOV 23 2015 QUIET WEATHER HIGHLIGHTS THE SHORT TERM PERIOD. CURRENTLY...THE STRONG LOW PRESSURE SYSTEM ASSOCIATED WITH YESTERDAY`S WINDY CONDITIONS WAS CENTERED OVER THE BORDER OF MANITOBA/ONTARIO/MINNESOTA. A WEAK HIGH PRESSURE AXIS EXTENDED FROM SOUTHERN ALBERTA SOUTHEASTWARD INTO EASTERN MONTANA AND THE WESTERN DAKOTAS...WITH BROAD LOW PRESSURE DEVELOPING IN THE LEE OF THE ROCKIES. TODAY THE STRONG LOW PRESSURE SYSTEM IS FORECAST TO MOVE EAST TOWARDS THE GREAT LAKES AND HUDSON BAY...AND THE SURFACE HIGH PRESSURE RIDGE AXIS MOVES EASTWARD INTO THE CENTRAL AND EASTERN DAKOTAS AS AN UPPER LEVEL RIDGE BUILDS/EXPANDS FROM THE ROCKIES INTO THE WESTERN PLAINS. MAINLY PARTLY CLOUDY SKIES TODAY WITH MIDDLE/HIGH CLOUDS MOVING EAST INTO NORTH DAKOTA. WARMER AIR IN SOUTHWESTERN NORTH DAKOTA WITH HIGHS IN THE LOWER 40S...WITH COOLER AIR TO THE NORTHEAST WITH HIGHS IN THE MID TO UPPER 30S. TONIGHT THE BROAD UPPER LEVEL RIDGE MIGRATES EASTWARD AND THE FLOW OVER THE ROCKIES BECOMES SOUTHWESTERLY ALOFT. IN RESPONSE...BROAD SURFACE LOW PRESSURE DEVELOPS OVER THE ROCKIES AND FRONT RANGE...AND A LONG BROAD FETCH OF SOUTHERLY SURFACE WINDS DEVELOPS FROM THE SOUTHERN PLAINS NORTHWARD INTO THE NORTHERN PLAINS. A LOW LEVEL JET DEVELOPS...AND THIS WILL ALLOW LOW LEVEL MOISTURE TO STREAM NORTHWARD INTO SOUTH CENTRAL CANADA. LOOK FOR INCREASING LOW CLOUDS WITH SOUTHEASTERLY SURFACE WINDS...AND INCREASING MID LEVEL CLOUDS MOVING IN FROM THE WEST/SOUTHWEST. LOW TEMPERATURES ARE EXPECTED TO BE IN THE 20S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 337 AM CST MON NOV 23 2015 THE FOCUS IN THE LONG TERM IS ON LIGHT SNOW POTENTIAL CENTERED ON WEDNESDAY. WE ARE BECOMING MORE CONFIDENT THAT ACCUMULATIONS WILL BE RELATIVELY LOW WITH THIS EVENT...POTENTIALLY LIMITING IMPACTS. THE 00 UTC MODEL SUITE WAS IN RELATIVELY GOOD AGREEMENT IN SHOWING LIGHT SNOW DEVELOPING IN WESTERN ND BY EARLY WEDNESDAY MORNING AND SPREADING EASTWARD DURING THE DAY. THE MULTI-MODEL CONSENSUS CALLS FOR LIQUID-EQUIVALENT MOISTURE VALUES OF 0.05 TO 0.15 INCHES /MOST IN FAR SOUTHWESTERN ND/...WHICH SHOULD CONTRIBUTE TO SNOW AMOUNTS RANGING FROM LESS THAN ONE-HALF INCH TO THE NORTH AND EAST OF THE MISSOURI RIVER...TO 1 TO 2 INCHES SOUTH AND WEST OF THE MISSOURI RIVER. OUR OFFICIAL FORECAST PRODUCED 3 INCH SNOW TOTALS ONLY IN EXTREME SOUTHWESTERN ND...BOWMAN AND SLOPE COUNTIES...WEDNESDAY THROUGH WEDNESDAY NIGHT. THE SNOW WILL BE GENERATED IN A POST-FRONTAL ENVIRONMENT...DRIVEN MAINLY BY DYNAMICS ASSOCIATED WITH A SHORTWAVE TROUGH EMBEDDED IN THE NORTHERN STREAM OF A SPLIT FLOW. THE 03 UTC SREF LINGERED THE SNOW LONGER THAN THE 00 UTC DETERMINISTIC GUIDANCE...SO A BIT OF UNCERTAINTY REMAINS...BUT IN GENERAL GUIDANCE CONTINUED TO SUGGEST THAT THE PRIMARY VERTICAL MOTION ASSOCIATED WITH THE 500-MB LOW IN THE GREAT BASIN WILL REMAIN DISPLACED SOUTH OF ND. IF THAT IS THE CASE...THANKSGIVING DAY MAY END UP COLD...BUT DRY IN MOST AREAS. ONE OTHER ISSUE WE WILL NEED TO CONSIDER IS WHETHER FOG DEVELOPS TUESDAY NIGHT...AND WHETHER LINGERING WARM AND DRY AIR ALOFT IS CAPABLE OF PRODUCING ANY LIGHT FREEZING RAIN OR LIGHT FREEZING DRIZZLE TUESDAY NIGHT INTO WEDNESDAY MORNING. FORECAST SOUNDINGS ARE NOT PARTICULARLY SUGGESTIVE OF THAT POTENTIAL THOUGH...SO WE ARE NOT MESSAGING THAT RISK AT THIS POINT. A REX BLOCK WILL DEVELOP ALOFT OVER THE WESTERN UNITED STATES BY NEXT WEEKEND AS THE GREAT BASIN LOW GETS PINCHED OFF TO THE SOUTH OF A DEVELOPING 500-MB RIDGE OVER WESTERN CANADA. THIS SCENARIO IS EXPECTED TO GENERATE A WARMING TREND AND MAINLY DRY WEATHER ACROSS THE AREA NEXT WEEKEND...THOUGH THE 00 UTC GFS /AND THE 00 UTC GFS ALONE/ DOES SUGGEST SOME SNOW POTENTIAL RETURNING NEXT SUNDAY WHEN IT BREAKS THE BLOCK DOWN AND KICKS THE REMNANT LOW ALOFT EASTWARD FURTHER NORTH THAN THE REST OF THE 00 UTC MODEL GUIDANCE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 959 AM CST MON NOV 23 2015 VFR CONDITIONS EXPECTED UNTIL AROUND 02Z-06Z MONDAY EVENING...WHEN INCREASING LOW CLOUDS WILL RESULT IN MVFR CIGS AT ALL TAF SITES. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...JV LONG TERM...CJS AVIATION...TWH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
320 PM CST MON NOV 23 2015 .TONIGHT - CONFIDENCE...MEDIUM. PER WATER VAPOR/RAP LOOP BROAD MID/UPPER LEVEL ANTICYCLONIC FLOW SHIFTING EASTWARD INTO WI. SFC/850 RIDGE AXES DRAW CLOSER WITH TIME WHICH RESULTS IN GRADUAL EROSION OF THE LOW LEVEL THERMAL TROUGH SO THINKING MUCH OF THE CLOUD COVER UPSTREAM ACROSS NRN MN AND NRN WI WILL NOT MAKE IT INTO OUR AREA PLUS SOME OF THIS IS DIURNALLY DRIVEN AS WELL. HOWEVER SREF CIG/VSBY PROGS ALONG WITH MET MOS ARE KEYING ON SOME FOG/STRATUS DEVELOPMENT AS THE NIGHT WEARS ON AND THIS WOULD MAKE THE MOST SENSE NEAR THE DEEPER SNOWFIELD ACROSS THE SRN CWA AND IN CLOSER PROXIMITY TO ARRIVING LIGHTER WIND REGIME ASSOC WITH RIDGE AXIS. VSBL SATELLITE ANIMATION DOES SHOW SOME EROSION OF THE SNOWPACK FROM THE EDGES AND SOME THINNING FROM WITHIN. LLVL RH PROGS/GFS MOS AND RAP SOUNDINGS ARE NOT TOO EXCITED ABOUT STRATUS/FOG DEVELOPMENT AND WITH MAINLY CIRRUS UPSTREAM NOTHING. HAVE ADDED PATCHY FOG IN THE SOUTHERN CWA AND BOOSTED SKY COVER A BIT LATER IN THE NIGHT. .TUESDAY - CONFIDENCE...MEDIUM SFC RIDGE AXIS SHIFTS EAST. WITH LIGHT WIND REGIME EARLY WITH SURFACE/850 RIDGE AXIS NEARBY ANY STRATUS/FOG EROSION MAY BE SLOW UNTIL BETTER SOUTHERLY FLOW SETS UP. THIS RETURN FLOW WILL HELP TO FURTHER MODIFY THE LOW LEVEL THERMAL PATTERN. HAVE BOOSTED TEMPS TO ACCOUNT FOR ADDITIONAL EROSION IN SNOWCOVER AND 925 TEMPS INCHING FURTHER ABOVE 0C ESP DURG THE AFTN WHEN SOUTHERLY FLOW RAMPS UP A BIT MORE. .TUESDAY NIGHT THROUGH THURSDAY - FORECAST CONFIDENCE...MEDIUM. NO SIGNIFICANT CHANGES FOR THIS PERIOD. ZONAL STEERING FLOW TRANSITIONS TO MORE SOUTHWEST FLOW AS LONG WAVE TROF PROGRESSES SOUTHEAST ACROSS WESTERN CONUS. NORTHERN PORTION OF TROF BREAKS AWAY AND BECOMES MORE PROGRESSIVE ACROSS NORTHERN CONUS WHILE CUTOFF LOW LINGERS OVER WESTERN CONUS. AHEAD OF THIS APPROACHING TROF...INCREASING SOUTHERLY WINDS IN THE LOW LEVELS WILL GRADUALLY PULL DEEPER MOISTURE NORTHWARD INTO THE AREA BEGINNING WEDNESDAY. COLUMN PWAT EXPECTED TO INCREASE TO OVER 1 INCH BY THU AFTN...WHICH WOULD BE NEAR OR SLIGHTLY ABOVE THE RECORD PWAT FOR NORTHWEST IL PER SPC SOUNDING CLIMATOLOGY AND STILL IN THE NEIGHBORHOOD OF 3 STANDARD DEVIATIONS FROM NORMAL. MAIN PERIOD OF RAIN LIKELY TO BE LATER THURSDAY INTO THURSDAY NIGHT WHEN DEEP MOISTURE WILL BE IN PLACE AND LOW LEVEL JET SURGES INTO THE TRI-STATE AREA OF SRN WI/NRN IL AND ERN IA. IN ADDITION...RIGHT ENTRANCE REGION OF UPPER JET PASSES ACROSS THIS SAME AREA DURING THE PERIOD. OF SHORT TERM GUIDANCE...GFS REMAINS OUTLIER WITH MORE PROGRESSIVE SOLUTION WITH STRONGEST SYNOPTIC FORCING JUST TO THE SOUTH OF WI. 18Z NAM...GEH-NH AND ECMWF REMAIN FOCUSED FARTHER NORTH SO ALONG WITH WPC...WILL LEAN ON THIS CONCENSUS WHICH INCREASES THE THREAT FOR A PERIOD OF HEAVY RAINFALL ACROSS SRN WI ON THU/THU NIGHT. STILL THINKING 1-1.5 INCHES MAY FALL IN A 6 TO 12 HOUR PERIOD. BY THAT TIME...THINKING THAT CURRENT SNOW COVER WILL BE CUT IN HALF DUE TO GRADUAL MELTING THE NEXT FEW DAYS. THREAT FOR THICKER FOG AND RELEASE OF LATENT HEAT OF CONDENSATION BEGINS WED NGT SO EXPECT SNOW COVER TO BEGIN DECREASING MORE RAPIDLY THEN. GROUND NOT FROZEN AND REMAINING SNOW SHOULD ABSORB SOME OF THE INITIAL RAIN. HOWEVER WITH LINGERING SNOW ACROSS FAR SOUTHERN COUNTIES AND PERIOD OF HEAVY RAIN...WOULD EXPECT RAPID RESPONDING RIVERS TO RISE THU NGT...INCLUDING THE FOX AND PECATONICA RIVERS. THE ROCK RIVER WILL ALSO LIKELY RESPOND BUT MORE SLOWLY IN ROCKCOUNTY. DUE TO THIS THREAT...WL UPDATE HYDROLOGIC OUTLOOK STATEMENT. .EXTENDED PERIOD...THURSDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE - MEDIUM TRENDING TO LOW. WITH LARGE SCALE TROF SWEEPING EASTWARD ACROSS THE WESTERN GREAT LAKES EARLY IN THE PERIOD AND WEAKER MID-LEVEL SHORT WAVE ENERGY MOVING NORTHEAST ALONG BAROCLINIC ZONE DRAPED ACROSS SRN WI AND THE ADJOINING REGION...WL CONTINUE CATEGORICAL POPS THURSDAY NIGHT. CURRENTLY GFS OUTLIER WITH FASTER SOUTHEAST PROGRESS OF SFC FRONT AND TIGHT BAROCLINIC ZONE THURSDAY NIGHT...WHICH WOULD HAVE GREATER IMPACT ON LOW LEVEL THERMAL PROFILE. THIS WOULD INCREASE THE PROBABILITY OF THE RAIN BECOMING MIXED WITH OR CHANGING OVER TO SNOW ACROSS THE NORTHERN AND WESTERN CWA BEFORE THE PRECIP ENDS ON FRIDAY. BOTH ECMWF AND GEM-NH SHOWING SLIGHTLY FASTER EWD PROGRESSION AS WELL SO WL CONTINUE TO MENTION POTENTIAL FOR MIX OR CHANGEOVER FROM WEST TO EAST 06Z-18Z FRI BEFORE PRECIP ENDS. NOT EXPECTING ANY LAKE EFFECT OR ENHANCEMENT ON FRIDAY AS COLD AIR SETTLES IN AS LOW LEVEL WINDS ANTICIPATED TO BE MORE NORTH TO NORTHWEST WHILE DEEPER LOW LEVEL RH IS IN THE AREA. LOW LEVEL WINDS DO VEER MORE NORTHEAST LATE FRI AND FRI NGT...HOWEVER LOW LEVEL MOISTURE VERY LIMITED AT THIS TIME...AND WIND SPEEDS RAPIDLY DIMINISH. 925H TEMPS FALL 10 TO 15C BY 00Z/SAT AND THESE COLDER TEMPERATURES SHOULD REMAIN ENTRENCHED OVER SRN WI THROUGH THE WEEKEND INTO THE FIRST DAYS OF DEC AS SHORT WAVE RIDGEING AND QUIETER CONDITIONS AFFECT WISCONSIN. LATEST GFS MORE AGRESSIVE ON STRONGER PIECE OF SHORT WAVE ENERGY MOVING NORTHEAST INTO THE CENTRAL MS VALLEY INTO PARTS OF THE WESTERN GTLAKES ON MONDAY. ECMWF DOES SHOW THIS STRENGTHENING LOW PRESSURE BUT WELL EAST AND SOUTH OF THE REGION. WPC MEDIUM RANGE DESK TRENDING AWAY FROM DETERMINISTIC GFS EARLY NEXT WEEK AND LEANING MORE ON DRIER ECMWF AND ECMWF ENSEMBLE. HENCE WL KEEP POPS LOW FOR THE MONDAY TIMEFRAME. && .AVIATION/00Z TAFS/...PRONOUNCED DRYING UPSTREAM PER VSBL SATELLITE IMAGERY AND EXPECT QUIET CONDITIONS TO CONTINUE INTO TUESDAY WITH HIGH PRESSURE RIDGE AXIS SLIDING INTO THE AREA TONIGHT AND THEN SHIFTING OFF TO THE EAST ON TUESDAY. A LITTLE MORE UNCERTAINTY ARISES LATER TONIGHT INTO TUESDAY MORNING. SREF CIG/VSBY PROG SHOWING SOME HIGHER CONFIDENCE IN FOG/STRATUS DEVELOPMENT IN SRN WI AS IS THE NAM MOS. TEMPS HAVE WARMED ABOVE FREEZING AND VSBL IMAGERY SHOWS SOME MELTING HAS OCCURRED TODAY SO AS RIDGE AXIS DRAWS CLOSER SOME FOG/STRATUS DEVELOPMENT POSSIBLE LATER TONIGHT INTO TUESDAY MORNING...ESPECIALLY NEAR THE DEEPER SNOWCOVER IN FAR SRN WI. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. $$ TONIGHT AND TUESDAY/AVIATION...PC TUESDAY NIGHT THROUGH MONDAY...MBK