Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPHI 260153 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 953 PM EDT WED MAR 25 2015 .SYNOPSIS... A WARM FRONT FROM SOUTHWEST PENNSYLVANIA THROUGH WEST VIRGINIA WILL HEAD NORTHEAST AND CROSS OUR REGION MIDDAY THURSDAY. THEN A COLD FRONT WILL MOVE ACROSS THE MID ATLANTIC STATES THURSDAY NIGHT. LOW PRESSURE MAY DEVELOP ON THAT FRONT OFF THE MID ATLANTIC COAST LATE FRIDAY AND HEAD NORTHEAST WELL OUT TO SEA SATURDAY. HIGH PRESSURE CENTERED OVER THE GREAT LAKES MIDWEST SATURDAY WILL BUILD TOWARD THE EAST COAST SATURDAY NIGHT INTO SUNDAY. AN AREA OF LOW PRESSURE IS EXPECTED TO TRACK TO OUR NORTH MONDAY, PULLING A COLD FRONT ACROSS THE AREA. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 930 PM ESTF: ADJUSTED POPS LOWER TO REFLECT DRYING ALOFT BEHIND THE BAND OF SHOWERS THAT CROSSED MUCH OF OUR AREA LATE THIS AFTN/EVENING. NOT THINKING MUCH DRIZZLE OVERNIGHT AND SO REDUCED THAT RISK. THINK THE FOG WILL HOLD OFF FOR A WHILE SINCE LOW CIGS NOT YET EVIDENT. TEMPS NEAR WHERE THEY ARE NOW AND NOT EXPECTING MUCH CHANGE OVERNIGHT. STEADY. A STRENGTHENING LOW LEVEL SOUTHWESTERLY JET WHICH SHOULD GENERATE WAA BANDS OF HEAVY SHOWERS AND ISOLATED TSTMS OVER THE DELMARVA AND FAR SNJ AFTER 09Z/26. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... A BAND OR BANDS OF HEAVY SHOWERS/ISOLATED TSTMS SHOULD MOVE NE OFF THE NJ/DE COASTS DURING THE MORNING AND THEN A BREAK IN THE WX WITH MORNING FOG/SPOTTY DRIZZLE LIFTING AND DISSIPATING BECAUSE OF WARM SOUTHWEST WIND GUSTS OF 25 TO 35 MPH DURING THE AFTN. FOG MAY BECOME QUITE THICK FOR SEVERAL HOURS DURING THE MORNING DAYLIGHT HOURS AS DEWPOINTS RISE AND THE WARM FRONT LOWERS TO THE SFC. THE THICKEST FOG ALONG AND N OF I 78 MAY BE DELAYED TIL MIDDAY. THE WARM FRONT WILL PROBABLY APPEAR NEAR I-78 NE THURSDAY AFTERNOON. WINDS WILL TURN MORE SOUTHWEST THROUGH THE MORNING AND A CONTINUED INFLUX OF WARMER AIR WILL SPREAD ACROSS THE REGION. HIGH TEMPERATURES THURSDAY AFTERNOON WILL RISE WELL INTO THE 60S AND INTO THE LOWER 70S THROUGH MUCH OF THE FORECAST AREA FROM NEAR PHILADELPHIA ANS TRENTON SOUTHWARD. NORTH OF THERE...HAVE MY DOUBTS AND WE MAY NEED TO CONSIDER LOWERING MAX TEMPS SEVERAL DEGREES NORTH OF I-78, OR AT LEAST DELAY MAX TEMP THERE TIL 6P. ALONG WITH THE WARM AIR FLOWING INTO THE OUR AREA, WE WILL SEE INCREASED INSTABILITY AND A POSSIBLY A CHANCE FOR SOME RUMBLES OF THUNDER LATE IN THE DAY INTO THE EARLY EVENING HOURS. THERE IS VERY LITTLE MLCAPE ON THURSDAY AND THE SWI STABILIZES AFTER THE MORNING VALUES WHICH ARE NEAR -2 ALONG THE COASTS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... A COLD FRONT WILL BE MOVING ACROSS THE AREA THURSDAY EVENING INTO THURSDAY NIGHT. SHOWERS WILL CONTINUE ACROSS THE AREA THROUGH THE EVENING AND INTO THE OVERNIGHT HOURS, ESPECIALLY AS THE COLD FRONT MOVES ACROSS THE AREA. THERE WILL REMAIN THE CHANCE FOR A FEW THUNDERSTORMS BEFORE THE FRONT PASSAGES THROUGH AS THERE REMAINS SOME WEAK INSTABILITY FORECAST. HOWEVER, ONCE THE FRONT MOVES THROUGH, THE THREAT FOR THUNDER DIMINISHES, BUT THERE WILL REMAIN SOME SHOWERS POST FRONTAL. QPF AMOUNTS ARE EXPECTED TO BE AROUND ONE QUARTER TO ONE THIRD OF AN INCH. BEHIND THE FRONT, IT LOOKS TO BE COLD ENOUGH ACROSS THE POCONOS FOR SNOW TO OCCUR IF SHOWERS HOLD ON THERE LONG ENOUGH. THE FRONT WILL PUSH OFFSHORE BY FRIDAY MORNING, BUT THERE WILL REMAIN THE CHANCE OF SHOWERS THROUGH FRIDAY AND FRIDAY NIGHT AS SEVERAL SHORT WAVE/VORTICITY IMPULSES ARE FORECAST TO SLIDE ACROSS THE AREA IN THE SOUTHWEST FLOW ALOFT. SHOWER ACTIVITY DOES NOT LOOK VERY ORGANIZED, SO WE KEEP ONLY 20/30 POPS FOR NOW. ON SATURDAY, AN AREA OF LOW PRESSURE IS EXPECTED TO STRENGTHEN ALONG THE FRONTAL BOUNDARY TO OUR EAST. HOWEVER, IT IS POSSIBLE THAT A WEAK SURFACE TROUGH MAY DEVELOP ON THE WESTERN SIDE OF THE LOW AND MOVE ACROSS OUR AREA. THIS SURFACE TROUGH MAY INTERACT WITH THE MID/UPPER TROUGH AS IT MOVES ACROSS THE AREA DURING THE DAY AND CREATE SOME SHOWER ACTIVITY. IT IS POSSIBLE THAT IT MAY BE COLD ENOUGH FOR SOME SNOW SHOWERS TO OCCUR, ESPECIALLY ACROSS NORTHERN SECTIONS. THE LOW AND TROUGH PULL AWAY FROM THE AREA SATURDAY NIGHT, WHILE HIGH PRESSURE BRIEFLY BUILDS ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY. THIS WILL BRING DRY WEATHER TO THE AREA FOR THROUGH THE DAY SUNDAY. FOR SUNDAY NIGHT INTO MONDAY, AN AREA OF LOW PRESSURE IS FORECAST TO SLIDE ACROSS THE NORTHEAST, BRINGING A COLD FRONT ACROSS THE EAST COAST. THIS WILL LEAD TO ANOTHER CHANCE OF ISOLATED/SCATTERED SHOWERS FOR THE AREA. ONCE AGAIN, IT MAY BE COLD ENOUGH ACROSS MUCH OF THE AREA FOR SOME SNOW TO OCCUR OVERNIGHT SUNDAY INTO MONDAY MORNING, BEFORE CHANGING TO RAIN DURING THE DAY. THE LOW WILL WILL PULL AWAY FROM THE AREA MONDAY NIGHT, ENDING PRECIPITATION CHANCES. HIGH PRESSURE IS EXPECTED TO BRIEFLY AFFECT THE AREA ON TUESDAY INTO TUESDAY NIGHT, THEN SHIFT TO OUR SOUTH ON WEDNESDAY. DRY WEATHER SHOULD PREVAIL FOR TUESDAY THROUGH EARLY WEDNESDAY. SHOWERS MAY RETURN LATE WEDNESDAY INTO WEDNESDAY NIGHT AS A WARM FRONT MAY LIFT ACROSS THE AREA. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. REST OF TONIGHT...VFR-MVFR CIGS FOR A WHILE. CONDS RAPIDLY LOWER TO IFR-LIFR IN ST/FOG AND POSSIBLE DRIZZLE BETWEEN 08Z AND 12Z/26. HEAVY SHOWERS OR A TSTM POSSIBLE VCNTY KMIV AFTER 10Z/26. TSTM NOT IN THE TAF ATTM. WINDS AT 2000 FT CURRENTLY SSW NEAR 35 KT WILL BECOME MORE SOUTHWESTERLY OVERNIGHT AND INCREASE TO BETWEEN 40-45 KT, ESPECIALLY SE NJ WHERE MAINTAINED A PERIOD LLWS. CONFIDENCE BELOW AVERAGE ON DETAILS. THURSDAY... IFR-LIFR CONDITIONS BEGIN THE DAY IN ST/FOG WITH SCT HEAVY SHOWERS AND ISOLATED TSTMS MAINLY DELMARVA ACROSS SE NJ EARLY IN THE DAY. CONDITIONS WILL GRADUALLY IMPROVE AND THERE MAY BE PERIODS OF VFR, ESPECIALLY DURING MID-LATE AFTERNOON WITH SW WIND GUSTS OF AROUND 30 KT DEVELOPING DURING THE AFTN MOST TAF SITES FROM PHL-TTN SOUTH AND EAST EXCEPT NOT KRDG AND KABE WHERE IFR CONDS MAY REMAIN MOST OF THE DAY. SHOWERS WILL REDEVELOP IN ADVANCE OF AN APPROACHING COLD FRONT. THERE IS A CHANCE FOR SOME THUNDER TO OCCUR JUST AHEAD OF AND ALONG THE COLD FRONT LATE IN THE DAY OR EVENING. OUTLOOK... THURSDAY NIGHT...COLD FRONTAL PASSAGE IN THE EVENING. GENERALLY VFR WITH MVFR/IFR CONDITIONS OCCURRING WITH SHOWERS AND ISOLATED THUNDERSTORMS. FRIDAY-FRIDAY NIGHT...MOSTLY VFR EXPECTED. SCATTERED SHOWER POSSIBLE. SATURDAY-SATURDAY NIGHT...MOSTLY VFR EXPECTED. SCATTERED SHOWERS POSSIBLE. SUNDAY...VFR. SUNDAY NIGHT-MONDAY...MOSTLY VFR. SCATTERED SHOWERS POSSIBLE. && .MARINE... SUB-ADVISORY CONDITIONS WILL CONTINUE THROUGH TONIGHT AND INTO EARLY THURSDAY. SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED FOR THURSDAY WITH THE ADVISORY IN EFFECT AT 8AM. A LOW LEVEL SOUTHWESTERLY JET AROUND 40 TO 50 KNOTS WILL CROSS THE AREA WATERS TONIGHT. WINDS ON THE OCEAN WILL NOT RESPOND INITIALLY AS THE WARMER AIR OVER THE COLDER WATERS IS RELATIVELY STABLE AND DOES NOT PROMOTE GOOD MIXING OF THE HIGHER WINDS TO THE SURFACE. WINDS WILL REMAIN OUT OF AN EAST TO SOUTHEAST DIRECTION AND SPEEDS WILL GENERALLY BE AROUND 10 KNOTS OR LESS THROUGH TONIGHT WITH AND INCREASE TO AROUND 10 TO 15 KNOTS BY THURSDAY MORNING. WINDS WILL CONTINUE TO INCREASE AND WE WILL SEE SUSTAINED WINDS AROUND 20 TO 25 KNOTS THURSDAY MORNING WITH GUSTS UP TO 30 KNOTS ON THE WATERS. WAVE HEIGHTS WILL REMAIN AROUND 2 FEET TONIGHT, INCREASING TO 2 TO 4 FEET BY THURSDAY MORNING. WAVE WILL CONTINUE TO INCREASE THROUGH THE DAY, BECOMING 4 TO 6 FEET BY THURSDAY AFTERNOON. OUTLOOK... THURSDAY NIGHT...SMALL CRAFT ADVISORY REMAINS IN EFFECT WITH ELEVATED WINDS AND SEAS. COLD FRONTAL PASSAGE EXPECTED DURING THE EVENING WITH A WIND SHIFT FROM SOUTHWEST TO NORTHWEST OVERNIGHT. FRIDAY...SMALL CRAFT ADVISORY CONDITIONS REMAINS OF THE OCEAN DUE TO ELEVATED SEAS. FRIDAY NIGHT...WINDS MAY INCREASE BACK TO SMALL CRAFT ADVISORY LEVELS OVERNIGHT. SATURDAY-SATURDAY NIGHT...WINDS AND SEAS MAY REMAIN NEAR SMALL CRAFT ADVISORY LEVELS. SUNDAY...CONDITIONS EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY LEVELS. SUNDAY NIGHT-MONDAY...WINDS AND SEAS INCREASE OVERNIGHT TO AT LEAST SMALL CRAFT ADVISORY LEVELS, POSSIBLY NEAR GALE FORCE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FROM 8 AM THURSDAY TO 6 PM EDT FRIDAY FOR ANZ450>455. SMALL CRAFT ADVISORY FROM 8 AM THURSDAY TO 8 AM EDT FRIDAY FOR ANZ430-431. && $$ SYNOPSIS...DRAG/ROBERTSON NEAR TERM...DRAG 954 SHORT TERM...DRAG/MEOLA 954 LONG TERM...ROBERTSON AVIATION...DRAG/ROBERTSON/MEOLA 954 MARINE...DRAG/ROBERTSON/MEOLA 954

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.