Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 251033 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 633 AM EDT SAT APR 25 2015 .SYNOPSIS... WEAK HIGH PRESSURE COVERS OUR AREA EARLY TODAY. LOW PRESSURE OVER THE LOWER OHIO VALLEY WILL PASS OFF THE NORTH CAROLINA COAST SUNDAY. THAT LOW BECOMES PART OF LARGE LOW PRESSURE CIRCULATION OVER THE NORTHWEST ATLANTIC EARLY NEXT WEEK. A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF MEXICO TUESDAY NIGHT EMERGES OFF THE SOUTHEASTERN SEABOARD LATE WEDNESDAY AND THURSDAY AND HEADS NORTHEAST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 630 AM PACKAGE: FROST/FREEZE HAZARD WILL BE DISCONTINUED BY 8 AM. APPEARS TO HAVE VERIFIED WELL. BASED ON 06Z NCEP MODELS...NO SIG CHANGE TO THE FCST ISSUED AT 330 AM. I DID ADD A LITTLE MORE SKYCOVER TODAY. TODAY...VARIABLE HIGH CLOUD COVER. THE THICKER SKYCOVER FROM FAR SE PA AND SNJ SOUTHWARD. SPRINKLES MAY DEVELOP TOWARD 6 PM OVER TALBOT/CAROLINE AND SOUTHERN SUSSEX COUNTIES ON THE SW EDGE OF OUR FCST AREA. FORECAST TEMPERATURES TODAY WERE A 1/3RD BLEND OF THE 00Z/25 GFS/NAM MOS AND 00Z/25 ECMWF 2M TEMPS. THE ECMWF IS QUITE COOL UNDER THE CLOUDS OVER THE DELMARVA AND HAVE MODIFIED THE NCEP MOS DOWNWARD THERE. WARMEST TEMPS IN OUR FCST AREA TODAY SHOULD BE IN NORTHERN NJ WHERE THERE SHOULD BE MORE SUNSHINE. A NICE DAY WITH MUCH LESS WIND THAN THE PREVIOUS WED-THU-FRIDAY AFTERNOONS. DAYTIMES TEMPS WILL BE WARMING A BIT EXCEPT THE DELMARVA WHERE IT WILL BE CHILLY TODAY AND MAXIMUM TEMPS ALMOST 15 DEGREES BELOW NORMAL WHILE MAXIMUM TEMPERATURES AROUND ALLENTOWN AND MOUNT POCONO NEWD THROUGH NNJ SHOULD ONLY BE 8 TO 10 DEGREES BELOW NORMAL. A WEAK WIND SHIFT BOUNDARY WILL BE FORMING JUST TO OUR NORTH LATE IN THE DAY WITH WESTERLY WINDS GUSTING TO 15 MPH DURING THE AFTERNOON IN PA AND NNJ BUT SEA BREEZES SHOULD DEVELOP COASTAL NJ AND COASTAL DE. WINDS ON THE DELMARVA WILL BE LIGHT WHERE LESS MIXING IS EXPECTED DUE TO HEAVIER SKYCOVER. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... TONIGHT...THICK HIGH CLOUD ALONG AND SOUTH OF I-78, WITH THE NORTHERN PORTION OF THE FORECAST RAIN SHIELD A BLEND OF HPC QPF, 50 50 00Z/25 NAM/GFS MOS AND MULTI MODEL .10 IN 6 HRS. THAT MEANS MAINLY THE SOUTHERNMOST 40 MILES OF OUR CWA, TALBOT COUNTY, QUEEN ANNES AND CAROLINE COUNTIES IN MD AND SUSSEX COUNTY DE, POSSIBLY KENT COUNTY DE AND POSSIBLY THE SRN TIP OF NJ. THIS CLOUD COVER TODAY AND CLOUD COVER/RAIN TONIGHT IS ASSOCIATED WITH THE LOW REDEVELOPING NEAR THE NC COAST. A WIND SHIFT FROM LIGHT WEST TO NORTH-NORTHEAST PROGRESSES FROM NORTH TO SOUTH THROUGH OUR CWA DURING THE NIGHT. PATCHY FROST IS IN THE FCST N OF I-78 TONIGHT. NO NEW FROST ADVY ATTM DUE TO THE UNCERTAINTY OF THE NORTHERN EDGE OF THICK CLOUD COVER. IT ALREADY FROZE UP THERE THIS MORNING SO EARLY SUSCEPTIBLE BLOOMS WERE PROBABLY DAMAGED. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A LOW PRESSURE SYSTEM WILL BE MOVING OFFSHORE SUNDAY MORNING AND ITS ASSOCIATED CLOUDS AND LIGHT RAINS WILL BE AFFECTING THE SRN PARTS OF OUR AREA. SOME LIGHT RAIN WILL PULL AWAY BY EVENING WITH PERHAPS UP TO A TENTH OF AN INCH POSSIBLE. ELSEWHERE...PARTLY TO MOSTLY SUNNY NORTH AND CENTRAL AREAS WITH TEMPERATURES NEAR NORMAL. COOLER AIR ARRIVES FOR MONDAY AND TUESDAY AS THE LARGE UPPER LOW OFFSHORE ROTATES A FEW SHORT WAVES AND SFC TROUGHS ACROSS THE AREA. SCT SHOWERS ARE EXPECTED MONDAY WITH CHC POPS. DRIER AIR ARRIVES TUE...BUT STILL A SLGT CHC FOR A SHOWER FAR NORTH. TEMPERATURES WILL RUN SEVERAL DEGREES BELOW NORMAL MON/TUE...WITH TUE LIKELY THE MILDER DAY. THE ECMWF/GFS MODELS BOTH SHOW ANOTHER SFC/UPPER LOW STRENGTHENING ACROSS THE SOUTHEAST STATES AND MOVING NORTHEAST...JUST EAST OF OUR AREA. IT APPEARS TO BE ANOTHER GLANCING SHOT OF CLOUDS AND RAINS S/E FOR THU AND INTO EARLY FRI. ANY CHANGES WITH THE TRACK COULD BRING SOME HEAVIER RAINS TO THE AREA. WE HAVE JUST USED THE WPC POPS FOR NOW...MOSTLY CHC (THU) AND SLGT CHC (THU NIGHT). TEMPERATURES WILL RETURN TO NEAR NORMAL FOR THE MIDDLE/LATE PART OF NEXT WEEK. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...BKN CIGS AOA 12000 FT DEVELOPING SOUTH PORTION MAY BRIEFLY THIN LATE IN THE DAY. HIGHER THINNER CLOUDS KABE NORTHWARD. LIGHT WEST - NORTHWEST WIND WIND BECOMING WEST MIDDAY WITH GUSTS TO 15 KT POSSIBLE DURING THE AFTERNOON IN NJ/PA BUT SEABREEZES DEVELOP ALONG COASTAL SECTIONS MID AND LATE AFTN. TONIGHT...CIGS AOA 8000 FT, ESPECIALLY AFTER 03Z/26. A SPRINKLE POSSIBLE KPHL/KILG/KMIV KACY BUT NOT IN THE FCST ATTM. IT MAY BE TOO DRY IN THE LAYER UNDER 8000 FT. LIGHT WEST WIND SHIFTING N-NE DURING THE NIGHT. PLEASE SEE TAFS FOR TIMING DETAILS AS A WIND SHIFT BOUNDARY SAGS SOUTHWARD. OUTLOOK... SUNDAY...MAINLY VFR CONDITIONS, AS ANY SUB-VFR IN RAIN TO START ACROSS SOUTHERN AREAS WILL IMPROVE BACK TO VFR. MONDAY...MAINLY VFR CONDITIONS; ALTHOUGH, SOME ISOLATED SHOWERS ARE POSSIBLE. GUSTY NORTH TO NORTHWEST WINDS, WITH GUSTS TO 20 KNOTS. TUESDAY AND WEDNESDAY...MAINLY VFR EXPECTED; ALTHOUGH, CONDITIONS MAY DETERIORATE LATE WEDNESDAY NIGHT DEPENDING ON THE TIMING AND TRACK OF A POSSIBLE COASTAL LOW PRESSURE. && .MARINE... SUB SCA CONDITIONS THROUGH TONIGHT WITH NORTHWEST TO NORTH WINDS BACKING TO WESTERLY MIDDAY THEN SEA BREEZES DURING MID - LATE AFTERNOON. LIGHT WINDS TONIGHT BECOMING N-NE LATE. OUTLOOK... SUNDAY/SUNDAY NIGHT...SUB-SCA CONDITIONS. RAIN SOUTH. MONDAY/MONDAY NIGHT...MOSTLY SUB-SCA BUT SOME WIND GUSTS AROUND 25 KTS POSSIBLE. SCATTERED SHOWERS. TUE THRU WED...MOSTLY SUB SCA. && .FIRE WEATHER... DRY CONDITIONS ARE EXPECTED ONCE AGAIN TODAY, WITH MINIMUM RH VALUES ONCE AGAIN RANGING FROM 20 TO 35 PERCENT NORTH TO SOUTH. HOWEVER, WINDS WILL BE CONSIDERABLY LIGHTER, WITH GUSTS GENERALLY NEAR OR BELOW 15 MPH THROUGH THE DAY. NO ACTION ATTM. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR PAZ060>062- 101>106. FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ070-071. NJ...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR NJZ001-007>010- 012-013-015>022-027. FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NJZ014-023>026. DE...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR DEZ001>004. MD...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR MDZ008. FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ012-015-019- 020. MARINE...NONE. && $$ SYNOPSIS...O`HARA NEAR TERM...DRAG 632 SHORT TERM...DRAG 632 LONG TERM...O`HARA AVIATION...DRAG/O`HARA 632 MARINE...DRAG/O`HARA 632 FIRE WEATHER...

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