Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 050739 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 339 AM EDT SAT SEP 5 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO OUR AREA FROM THE NORTH TODAY, THEN BECOME MOSTLY CENTERED OFFSHORE SUNDAY AND MONDAY. A COLD FRONT IS FORECAST TO APPROACH OUR REGION LATE WEDNESDAY, THEN STALL NEARBY THURSDAY INTO FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGH PRESSURE WAS CENTERED OVER NORTHERN NEW ENGLAND THIS MORNING. THE CENTER OF THE HIGH WILL SLIDE TO THE SOUTH TODAY AND IT IS EXPECTED TO REACH THE WATERS OFF CAPE COD TOWARD EVENING. A NORTHEAST TO EAST SURFACE FLOW WILL CONTINUE IN OUR FORECAST AREA FOR TODAY. THE ONSHORE FLOW IS EXPECTED TO BRING ADDITIONAL CLOUDS THIS MORNING. HOWEVER, AS THE CENTER OF THE HIGH DRIFTS CLOSER, DRY AIR SHOULD BEGIN TO NUDGE INTO OUR REGION WITH A CLEARING TREND ANTICIPATED FROM THE NORTHEAST AND EAST DURING THE AFTERNOON. THE ONSHORE FLOW SHOULD PREVENT ANY LOCATION IN OUR FORECAST AREA FROM REACHING 90 DEGREES TODAY. HIGHS ARE EXPECTED TO FAVOR THE LOWER AND MIDDLE 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE CENTER OF THE HIGH IS FORECAST TO ELONGATE FROM WEST TO EAST TONIGHT AS IT DRIFTS SOUTHWARD. AS A RESULT, THE ONSHORE FLOW IN OUR REGION WILL LIKELY WEAKEN. DRY AIR WILL CONTINUE TO WORK ITS WAY INTO OUR FORECAST AREA AND WE ARE ANTICIPATING A MAINLY CLEAR SKY. THE LACK OF CLOUD COVER AND THE DIMINISHING WIND SHOULD ALLOW TEMPERATURES TO DROP INTO THE UPPER 50S AND LOWER 60S AT MOST LOCATIONS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... THE SYNOPTIC SETUP IS COMPRISED OF A RIDGE ACROSS THE EAST AND A TROUGH IN THE WEST TO START. AS THE TROUGH EJECTS EASTWARD ACROSS THE NORTHERN PLAINS AND MIDWEST SUNDAY INTO MONDAY, THE PORTION OF THE RIDGE IN THE NORTHEAST AND MID ATLANTIC IS FORECAST TO FLATTEN SOME FROM THE NORTH. THE INITIAL TROUGH LIFTS WELL INTO CANADA LATE WEDNESDAY AND THURSDAY WITH ANOTHER ONE THEN GRADUALLY SLIDING EAST- NORTHEAST THURSDAY AND FRIDAY. THE MODEL GUIDANCE HAS BEEN SLOWING THE ASSOCIATED SURFACE COLD FRONT/S/, WHICH IS DUE TO THE LAGGING OF THE UPPER-LEVEL FEATURE PLUS SOME RIDGING NEAR THE SOUTHEASTERN U.S. COAST. IT STILL APPEARS THAT A WARMING AIRMASS WILL OVERSPREAD THE AREA NEXT WEEK FOR AWHILE, AND GENERALLY DRY CONDITIONS TO CONTINUE. THE CWA NEEDS RAIN, HOWEVER IT LOOKS LIKE THE CHCS ARE LOW GIVEN NO SIGNIFICANT SYSTEMS MOVING THROUGH ALTHOUGH THE LATE WEEK FRONT MAY END UP STALLING IN OUR VICINITY AND OPEN THE DOOR FOR INCREASED RAIN CHCS. WE USED A MODEL/CONTINUITY BLEND FOR SUNDAY INTO TUESDAY, WITH A 00Z WPC GUIDANCE/CONTINUITY BLEND THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE AFTER ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES. FOR SUNDAY...AN UPPER-LEVEL RIDGE IS IN PLACE ALTHOUGH IT STARTS TO FLATTEN ON THE NORTHERN SIDE AS SHORT WAVES SLIDE UP INTO CANADA. AT THE SURFACE HIGH PRESSURE IS FORECAST TO BE MORE CENTERED OFFSHORE, ALLOWING THE WINDS TO TURN FROM NORTHEAST AND EAST TO SOUTHEASTERLY. WHILE THIS WILL ALLOW FOR SOME MODERATION IN THE TEMPERATURES OVER LAND, THE COASTAL AREAS WILL BE COOLER. SOME MOISTURE OFF THE CAROLINA COAST SHOULD REMAIN SOUTH OF THE AREA WITH OUR CWA MOSTLY PROTECTED BY THE UPPER-LEVEL RIDGE AND SURFACE HIGH PRESSURE. SOME RADIATIONAL COOLING INDUCED FOG HOWEVER MAY BE AROUND TO START THE DAY PENDING LIMITED CLOUDS. FOR MONDAY AND TUESDAY...A SIMILAR SETUP AS THE RIDGE LOOKS TO SLIDE A BIT FARTHER EAST AS A TROUGH MOVES ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES. OUR WEATHER SHOULD BE GENERALLY DOMINATED BY SURFACE HIGH PRESSURE ANCHORED OFFSHORE, THEREFORE WITH A BETTER ESTABLISHED SOUTHERLY FLOW WE LOOK TO HEAT UP SOME MORE. IT ALSO LOOKS LIKE THE HUMIDITY STARTS TO CREEP BACK UP MORE TOWARD NOTICEABLE LEVELS. FOR WEDNESDAY THROUGH FRIDAY...THE INITIAL UPPER-LEVEL TROUGH/CLOSED LOW LOOKS TO TRACK WELL INTO CANADA WEDNESDAY, HOWEVER ANOTHER ONE IN ITS WAKE MOVES FROM THE NORTHERN PLAINS TO THE GREAT LAKES AND MAY SHARPEN WITH TIME. THERE MAY BE A SURFACE TROUGH IN OUR VICINITY WEDNESDAY WITH PERHAPS A FEW SHOWERS OR THUNDERSTORMS FOR THE INTERIOR DURING PEAK HEATING, OTHERWISE THE MAIN COLD FRONT CONTINUES TO SLOW. THIS IS MAINLY DUE TO THE INITIAL ENERGY TRACKING SO FAR TO OUR WEST AND NORTH, AND THEREFORE THE FRONT MAY ARRIVE LATE WEDNESDAY BUT THEN EITHER STALL OR START TO WASHOUT ACROSS OUR AREA. THERE IS LESS CERTAINTY WITH THE UPPER-LEVEL TROUGH TO OUR WEST AND HOW AMPLIFIED IT BECOMES. THIS WILL AFFECT HOW QUICKLY THE FRONT ARRIVES ALONG WITH ANY POSSIBLE WEAK SURFACE LOWS THAT DEVELOP ALONG IT. THERE IS THE CHC OF A LEAD SHORT WAVE THAT DEVELOPS A WEAK SURFACE LOW ALONG THE INITIAL/LINGERING FRONT IN OUR VICINITY, THEN THE MAIN FRONT SHOULD APPROACH LATE FRIDAY. WE BLENDED IN THE NEW 00Z WPC GUIDANCE WITH CONTINUITY GIVEN LESS CERTAINTY WITH THE TIMING AND DETAILS. THIS ALLOWS FOR CHC POPS FOR CONVECTION ESPECIALLY THURSDAY AND FRIDAY. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AN ONSHORE FLOW WILL LIKELY KEEP MVFR CEILINGS OVER MUCH OF OUR REGION FOR MOST OF THIS MORNING. SCATTERED IFR CEILINGS ARE POSSIBLE IN NEW JERSEY AND IN THE ELEVATED TERRAIN OF THE POCONOS. CEILINGS SHOULD LIFT AND THE CLOUD COVER IS ANTICIPATED TO BECOME SCATTERED FOR THIS AFTERNOON. A MAINLY CLEAR SKY IS EXPECTED FOR TONIGHT WITH PATCHY FOG POSSIBLE, ESPECIALLY AWAY FROM URBAN CENTERS. AS A RESULT, WE MAY NEED TO MENTION VISIBILITY RESTRICTIONS FOR LATE TONIGHT AT KRDG AND KMIV. THE TWO LOCATIONS ARE USUALLY MORE SUSCEPTIBLE TO FOG THAN OUR OTHER SIX TAF SITES. A NORTHEAST TO EAST WIND AROUND 8 TO 12 KNOTS IS EXPECTED FOR TODAY. WIND SPEEDS SHOULD DROP TO 6 KNOTS OR LESS FOR TONIGHT WITH THE DIRECTION FAVORING THE NORTHEAST OR BECOMING VARIABLE. OUTLOOK... SUNDAY AND MONDAY...A CHANCE FOR EARLY MORNING FOG MAINLY AT THE MORE RURAL TERMINALS, OTHERWISE VFR. EAST TO SOUTHEAST WINDS 4-8 KNOTS SUNDAY /DIMINISHING AT NIGHT/, THEN TURNING MORE SOUTH AND SOUTHWEST ON MONDAY. TUESDAY AND WEDNESDAY...VFR OVERALL. A FEW SHOWERS OR THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY AFTERNOON, ESPECIALLY NORTH AND WEST OF KPHL. && .MARINE... HIGH PRESSURE LOCATED OVER NORTHERN NEW ENGLAND EARLY THIS MORNING WILL SINK TO THE SOUTH DURING TODAY AND TONIGHT. A BRISK ONSHORE FLOW IS ANTICIPATED FOR TODAY WITH WIND SPEEDS DECREASING TONIGHT. WE WILL CONTINUE THE SMALL CRAFT ADVISORY UNTIL 600 PM FOR OUR OCEAN WATERS NORTH OF ATLANTIC CITY WHERE THE WIND GUSTS SHOULD FALL BELOW 25 KNOTS BY LATE IN THE DAY. WE WILL EXTEND THE ADVISORY UNTIL MIDNIGHT FOR OUR WATERS OFF ATLANTIC CITY AND POINTS SOUTHWARD TO ALLOW WINDS AND SEAS A CHANCE TO SUBSIDE THERE. THE WINDS SHOULD TAKE A LITTLE LONGER TO DIMINISH IN THE SOUTH AS THE TIGHTER PRESSURE GRADIENT DRIFTS SOUTHWARD. THE SMALL CRAFT ADVISORY FOR LOWER DELAWARE BAY HAS BEEN EXTENDED UNTIL 200 PM WITH WIND GUSTS NEAR 25 KNOTS ANTICIPATED NEAR THE MOUTH OF THE BAY UNTIL THAT TIME. NO ADVISORY IS IN EFFECT FOR UPPER DELAWARE BAY WHICH SHOULD BE SHELTERED FROM THE STRONGEST OF THE WIND GUSTS. OUTLOOK... SUNDAY THROUGH WEDNESDAY...HIGH PRESSURE ANCHORED TO OUR EAST FOR MUCH OF THIS TIME FRAME WILL ALLOW A SOUTHERLY FLOW REGIME TO BECOME ESTABLISHED. WHILE THESE WINDS SHOULD INCREASE AT TIMES, ESPECIALLY IN THE AFTERNOON AND EVENING NEARSHORE WITH A SEA/BAY BREEZE, THEY ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. THE SEAS ALSO ARE ANTICIPATED TO REMAIN BELOW 5 FEET. && .RIP CURRENTS... WE WILL GO WITH A HIGH RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS FOR TODAY. A BRISK EAST NORTHEAST SURFACE FLOW ALONG WITH AN EASTERLY SWELL AND WAVE HEIGHTS IN THE 4 TO 6 FOOT RANGE WILL CREATE HAZARDOUS CONDITIONS AT THE NEW JERSEY SHORE AND AT THE DELAWARE BEACHES. FOR SUNDAY AND MONDAY...A NORTHEAST TO EAST WIND SUNDAY WILL TURN SOUTHEASTERLY BY LATE DAY AND ALSO BE 10-15 MPH. THE WAVES ARE FORECAST TO BE ON THE DECREASE, AND AS OF NOW THE ELEVATED RIP CURRENT RISK LOOKS TO BE DECREASING SUNDAY AND MONDAY. FOR SUNDAY, THE RISK LEVEL WILL MAINLY DEPEND ON HOW THE ELEVATED SEAS TODAY SUBSIDE HOWEVER THE DAY MAY START WITH A MODERATE RISK. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR NJZ014-024>026. DE...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR DEZ004. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ452>455. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ450- 451. SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ431. && $$ SYNOPSIS...GORSE NEAR TERM...IOVINO SHORT TERM...IOVINO LONG TERM...GORSE AVIATION...GORSE/IOVINO MARINE...GORSE/IOVINO RIP CURRENTS...GORSE/IOVINO

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