Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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990 FXUS61 KPHI 100532 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1232 AM EST WED FEB 10 2016 .SYNOPSIS... A WEAK SYSTEM WILL MOVE NORTHEAST OF OUR REGION OVERNIGHT INTO WEDNESDAY. HIGH PRESSURE WILL WORK EASTWARD THROUGH THE REGION THURSDAY INTO FRIDAY BEFORE GIVING WAY TO AN ARCTIC FRONT ON FRIDAY NIGHT AND SATURDAY. HIGH PRESSURE WILL BUILD ACROSS THE AREA ON SUNDAY AND MONDAY, THEN LOW PRESSURE IS EXPECTED TO FORM ALONG THE MID ATLANTIC OR SOUTHEAST COAST ON TUESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 930 PM UPDATE...THE WINTER WEATHER ADVISORIES AND WINTER STORM WARNING HAS BEEN CANCELLED. A STRONG UPPER-LEVEL TROUGH IN THE EAST WILL CONTINUE TO CIRCULATE SHORT WAVE ENERGY ACROSS THE REGION THROUGH THE OVERNIGHT. ONE SHORT WAVE MOVING THROUGH THIS EVENING HAS HELPED TO MAINTAIN BANDS OF MORE ORGANIZED SNOW, HOWEVER THESE ARE TENDING TO WEAKEN AS THEY LIFT SLOWLY TO THE NORTHEAST. IT APPEARS THAT THE EARLIER CONVERGENCE THAT HELPED TO STRENGTHEN A BAND OF SNOW HAS WEAKENED AS IT GRADUALLY LIFTED NORTHEASTWARD AND WE CONTINUE TO SEE A DOWNWARD TREND IN THE OVERALL REFLECTIVITIES. HOWEVER, DESPITE LESSENING RADAR REFLECTIVITY FARTHER WEST THERE IS STILL LIGHT SNOW FALLING. OVERALL, THE TREND APPEARS TO CONTINUE TO BE MORE OF A SNOW SHOWER VARIETY INSTEAD OF A WIDESPREAD SNOW. THEREFORE, THE FORECAST WAS ADJUSTED ACCORDINGLY. GIVEN THE LACK OF REAL ORGANIZATION, SNOWFALL AMOUNTS LOWER ACROSS MANY AREAS AND NOT A LOT OF ADDITIONAL ACCUMULATION EXPECTED THROUGH THE OVERNIGHT, THE ADVISORIES AND WARNING HAVE BEEN CANCELLED. BASED ON SOME REPORTS, MUCH OF THE SNOW ACCUMULATIONS HAVE BEEN ON NON- ROADWAY SURFACES WITH THE ROADS THEMSELVES BEING MOSTLY WET. THE HEAVIEST SNOW HAS FALLEN IN PORTIONS OF CHESTER TO BERKS COUNTIES WITH LESSER AMOUNTS AS ONE HEADS TO THE EAST AND NORTH FROM THERE. THE UPDATED SNOWFALL GRAPHIC WILL DEPICT ADDITIONAL ACCUMULATIONS OVERNIGHT WHICH RANGES FROM A COATING UP TO 2 INCHES /HIGHEST ACROSS THE NORTHWEST ZONES/. OF COURSE IN SITUATIONS LIKE THESE, LOCALLY SLIPPERY CONDITIONS CAN OCCUR ON UNTREATED SURFACES. THE MODEL GUIDANCE DOES SHOW A STRONGER SHORT WAVE ARRIVING TOWARD MORNING, AND THIS COULD DEVELOP SOME SNOW SHOWERS ESPECIALLY ACROSS THE EASTERN AREAS. THE HOURLY TEMPERATURE AND DEW POINT GRIDS WERE ADJUSTED WITH THE LATEST OBSERVATIONS, THEN THE LAMP/LAV GUIDANCE WAS BLENDED IN. NO MAJOR CHANGES WERE MADE TO THE LOW TEMPERATURES ATTM. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/... ANY LIGHT SNOW SHOWERS WILL BE WINDING DOWN AS A STRONGER SHORT WAVE MOVES THROUGH TO START THE DAY. TEMPERATURES WILL BE IN THE UPPER 20S TO LOWERS 30S ACROSS MOST OF THE AREA AT RUSH HOUR. ALTHOUGH THE SNOW WILL HAVE ENDED OVER MOST OF THE REGION, LOCALLY SLIPPERY CONDITIONS CAN OCCUR ON UNTREATED SURFACES. OTHERWISE, IT WILL BE A MOSTLY CLOUDY DAY WITH SEASONABLE TEMPS. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... OVERVIEW...IF I HAD TO CONVEY JUST ONE THING DURING THIS PERIOD IT WOULD BE THE COLDEST AIR OF THE SEASON IS EXPECTED TO ARRIVE THIS WEEKEND. THE OVERALL PATTERN OVER NORTH AMERICA THROUGH THE PERIOD WILL BE A TROF ACROSS THE EAST AND A RIDGE ACROSS THE WEST. LOOKS LIKE TWO PIECES OF POLAR/ARCTIC AIR WILL WORKS ITS WAY TOWARD THE NORTHERN MID-ATLANTIC WITH THE FIRST PIECE ARRIVING THIS THURSDAY. A TROF OR COLD FRONT SHOULD PASS THROUGH WEDNESDAY NIGHT LEADING THE WAY FOR THE COLD AIR. WEAK HIGH PRESSURE WILL BUILD LATER ON THURSDAY AND PERSIST INTO FRIDAY. AS THIS OCCURS THE MID-LEVEL TROF WILL RELOAD. A SECOND FRONT IS FORECAST TO MOVE THROUGH SOMETIME ON FRIDAY NIGHT INTO SATURDAY MORNING. IT`S BEHIND THIS FRONT WHERE THE COLDEST AIR OF THE SEASON IS FORECAST...H8 TEMPS BOTTOMING OUT IN THE -25 TO 30 DEGREE C RANGE. ON SUNDAY BEHIND THE COLD FRONT, THE CENTER OF SURFACE HIGH SHOULD BE SOMEWHERE NEAR THE OHIO VALLEY. BECAUSE OF THIS (WILL STILL HAVE A GRADIENT), WINDS WILL BE QUITE NOTICEABLE. BY MONDAY (PRESIDENTS DAY), THE HIGH IS FORECAST TO SHIFT TO THE EASTERN SEABOARD. BY TUESDAY, THE SAME FEATURE SHOULD SHIFT OFFSHORE PROVIDING A RETURN FLOW BEFORE THE NEXT FROPA. TEMPERATURES...TO BE ABLE TO GET SOME PERSPECTIVE, NORMALS FOR KPHL ARE BASICALLY IN THE LOW 40S AND MID 20S THROUGH THE PERIOD. THAT SAID, BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH THE WEEKEND. WE`LL START TO MODERATE ON MONDAY (NEAR NORMAL) AND REBOUND FURTHER ON TUESDAY (ABOVE NORMAL). TEMPERATURES MAY NOT CLIMB ABOVE FREEZING ACROSS MOST, IF NOT ALL, THE FORECAST AREA FROM EARLY THURSDAY MORNING TO MONDAY MORNING. LOWS IN THE SINGLE DIGITS AND TEENS WILL BE THE RULE, BUT ON SUNDAY MORNING, TEMPERATURES FROM ABOUT 5 BELOW TO FIVE ABOVE ARE POSSIBLE. HIGHS IN THE TEENS AND 20S THROUGH THIS TIME FRAME WILL BE COMMON. PRECIPITATION...NOT SEEING ANY LARGE SCALE EVENTS THROUGH THE PERIOD. SMALL POPS ACROSS PORTIONS OF THE AREA WEDNESDAY NIGHT INTO THURSDAY. SMALL POPS AGAIN WITH THE COLD FRONT FRIDAY NIGHT INTO SATURDAY. ANOTHER SHOT ON TUESDAY. WIND AND WIND CHILLS...WEST TO NORTHWEST WINDS WILL PREVAIL WEDNESDAY NIGHT THROUGH SUNDAY NIGHT. A SOUTHERLY COMPONENT CAN BE EXPECTED MONDAY INTO TUESDAY. SPEEDS WILL BE IN THE 10 TO 20 RANGE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THEY WILL RELAX ON FRIDAY AND FRIDAY NIGHT AND RAMP BACK UP SATURDAY NIGHT AND SUNDAY. WIND CHILLS ON SUNDAY MORNING COULD BE IN THE -15 TO -25 DEGREE F RANGE, COLDEST NORTH AND WEST. IMPACTS...IMPACTS WILL BE TIED MORE TO TEMPERATURES RATHER THAN PRECIPITATION. BUT KEEP IN MIND THAT ANY SNOW SHOWER OR SQUALL CAN GREATLY REDUCE VISIBILITIES. BITTERLY COLD AIR CAN BE ANTICIPATED ON SUNDAY MORNING WITH WIND CHILLS IN THE -15 TO -25 DEGREE F RANGE. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
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THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. OVERNIGHT...IFR/MVFR CEILINGS WITH SOME IMPROVEMENT TO VFR AT TIMES. THE VISIBILITIES WILL BE REDUCED TO IFR/MVFR AT TIMES DUE TO LINGERING SNOW SHOWERS FOR THE NEXT FEW HOURS. A MORE WIDESPREAD IMPROVEMENT TO VFR IS ANTICIPATED TOWARD 12Z FROM WEST TO EAST. WINDS LIGHT AND SOMEWHAT VARIABLE, BECOMING WEST-NORTHWEST WITH SOME INCREASE TO ABOUT 5-10 KNOTS. WEDNESDAY...VFR CEILINGS. WEST-NORTHWEST WINDS INCREASING TO 10-15 KNOTS WITH GUSTS UP TO 25 KNOTS. OUTLOOK... WEDNESDAY NIGHT THROUGH THURSDAY: MAINLY VFR, SOME BRIEF MVFR RESTRICTIONS IN ISOLATED SNOW SHOWERS AND FLURRIES. NORTHWEST WINDS 15-25 KNOTS WITH HIGHER GUSTS. THURSDAY NIGHT AND FRIDAY: VFR. NORTHWEST WINDS, BRIEFLY BECOMING SOUTHWEST ON FRIDAY...10 KNOTS OF LESS. FRIDAY NIGHT AND SATURDAY: MAINLY VFR, POSSIBLE MVFR RESTRICTIONS IN SCATTERED SNOW SHOWERS. NORTHWEST WINDS INCREASING SATURDAY FROM 15-25 KNOTS WITH HIGHER GUSTS. SUNDAY...VFR WITH DIMINISHING NORTHWEST WINDS.
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&& .MARINE... FOR TONIGHT AND WEDNESDAY...SCA REMAINS IN EFFECT FOR THE ENTIRE PERIOD, MAINLY FOR HAZARDOUS SEAS IN THE 4 TO 7 FT RANGE. OUTLOOK... A GALE WATCH WILL BE ISSUED FOR WEDNESDAY NIGHT AND THURSDAY. WEST TO NORTHWEST WINDS WILL BE INCREASING WEDNESDAY NIGHT BENEATH STRONG COLD ADVECTION AND A DEEPENING BOUNDARY LAYER. PER BUFKIT, THE TRANSFER IN THE MIXED LAYER IS STRONG. FREEZING SPRAY SHOULD DEVELOP AS WELL. NORTHWEST GALES ARE LIKELY ONCE AGAIN SATURDAY INTO SUNDAY AS THE COLDEST AIR OF THE SEASON ARRIVES, POSSIBLY AS COLD AS THE COLDEST PERIOD OF LAST FEBRUARY. MODERATE TO HEAVY FREEZING SPRAY RATES SHOULD DEVELOP AS WELL. && .TIDES/COASTAL FLOODING...
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LOW PRESSURE WILL CONTINUE TO MOVE FARTHER OUT TO SEA AND A TRAILING SURFACE TROUGH IS EXPECTED TO DRIFT NORTHEASTWARD THROUGH OUR REGION OVERNIGHT. AN ONSHORE FLOW IS FORECAST TO PERSIST UNTIL THE TROUGH PASSES AND BRINGS A SHIFT TO A WESTERLY WIND. THE WIND SHIFT HAD ALREADY ARRIVED IN MARYLAND AND DELAWARE BY MID EVENING. IT SHOULD WORK ITS WAY ACROSS DELAWARE BAY AND SOUTHERN NEW JERSEY UP TO ABOUT LONG BEACH ISLAND BY MIDNIGHT. THE WIND SHIFT IS EXPECTED TO REACH THE NORTHERN PART OF THE JERSEY SHORE LATE TONIGHT. ANOTHER ROUND OF MINOR FLOODING WAS OCCURRING ALONG THE COASTS OF DELAWARE AND NEW JERSEY AND ALONG DELAWARE BAY THIS EVENING. AS A RESULT, A COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL MIDNIGHT. THE COASTAL FLOOD WARNING THAT WAS ISSUED FOR MIDDLESEX COUNTY AND MONMOUTH COUNTY WAS DOWNGRADED TO AN ADVISORY BASED ON THIS EVENING`S TIDAL TRENDS. IT APPEARS AS THOUGH THE COASTAL FLOODING MAY WORK ITS WAY UP TO NEW CASTLE COUNTY AND SALEM COUNTY FOR THE OVERNIGHT HIGH TIDE SO AN ADVISORY REMAINS IN EFFECT THERE UNTIL 200 AM. AS THE WIND SHIFT TAKES HOLD AND WATER BEGINS TO BE PUSHED AWAY FROM THE SOUTHERN PART OF OUR COAST, POSITIVE DEPARTURES SHOULD COME DOWN ENOUGH TO SPARE THE TIDAL DELAWARE RIVER FROM ANOTHER ROUND OF MINOR FLOODING LATE TONIGHT. WE THINK THAT THIS ROUND OF ADVISORIES SHOULD BE THE LAST FOR COASTAL AREAS OF DELAWARE, DELAWARE BAY AND PERHAPS FAR SOUTHERN NEW JERSEY. HOWEVER, THE FACT THAT THE WIND WILL NOT TURN TO THE WEST UNTIL LATE TONIGHT ALONG THE NORTHERN PART OF THE JERSEY SHORE GIVES US CONCERN THAT THE WATER WILL HOLD THERE FOR WEDNESDAY MORNING`S HIGH TIDE. THUS, HAVE ISSUED A COASTAL FLOOD ADVISORY FOR MIDDLESEX, MONMOUTH, AND OCEAN COUNTIES FOR THE HIGH TIDE WEDNESDAY MORNING. THERE REMAINED A FAIR AMOUNT OF WATER BOTTLED UP IN CHESAPEAKE BAY THIS EVENING. WHILE THE WESTERLY WIND HAS REACHED THE BAY AND IT SHOULD BEGIN TO DRAIN, WE THINK THAT IT WILL NOT BE IN TIME TO PREVENT ANOTHER ROUND OF MINOR FLOODING ALONG THE UPPER EASTERN SHORE FROM THE CHOPTANK RIVER UP TO KENT ISLAND. AS A RESULT, WE HAVE ISSUED ANOTHER COASTAL FLOOD ADVISORY FOR THE COUNTIES OF CAROLINE, TALBOT AND QUEEN ANNE`S AND IT COVERS THE LATE NIGHT AND EARLY MORNING HIGH TIDE. WE SHOULD NOT NEED TO EXTENDED THE ADVISORY FARTHER NORTH TO KENT COUNTY AND CECIL COUNTY BASED ON THIS EVENING`S TIDAL TRENDS IN THOSE TWO COUNTIES.
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&& .CLIMATE... NEAR RECORD COLD IS EXPECTED FOR PORTIONS OF OUR AREA SUNDAY MORNING AND BY FAR THE COLDEST AIR OF THE SEASON SO FAR. 2015-16 SO FAR RER 14TH ABE 8......... -1 1979 ACY 10........ -6 1979 PHL 12........ +2 1979 ILG 12........ -4 1979 RDG 10........ -4-1983 TTN 9......... 0 1916 GED 13........ -7 1979 MPO -1........ -12 1970 ADDITIONALLY...THIS WILL BE WIND DRIVEN COLD WITH MANY AREAS EXPERIENCING WIND CHILL VALUES OF 15 TO 20 BELOW ZERO...POSSIBLY 25 BELOW IN THE HILLS AND MOUNTAINS OF NORTHWEST NEW JERSEY AND NORTHEAST PENNSYLVANIA. && .PHI WATCHES/WARNINGS/ADVISORIES...
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PA...NONE. NJ...COASTAL FLOOD ADVISORY FROM 8 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR NJZ012>014-020-026. COASTAL FLOOD ADVISORY UNTIL 2 AM EST EARLY THIS MORNING FOR NJZ016. DE...COASTAL FLOOD ADVISORY UNTIL 2 AM EST EARLY THIS MORNING FOR DEZ001. MD...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR MDZ015- 019-020. MARINE...GALE WATCH FROM THIS EVENING THROUGH THURSDAY AFTERNOON FOR ANZ430-431-450>455. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455.
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&& $$ SYNOPSIS...KRUZDLO NEAR TERM...GORSE SHORT TERM...FRANCK LONG TERM...KRUZDLO AVIATION...GORSE/JOHNSON/KRUZDLO MARINE...FRANCK/KRUZDLO TIDES/COASTAL FLOODING... CLIMATE...

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