Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 220746 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 346 AM EDT MON SEP 22 2014 .SYNOPSIS... IN THE WAKE OF THE COLD FRONT THAT MOVED THROUGH LAST NIGHT, A HIGH WILL BUILD IN OVER THE REGION TO START THE WEEK. BY THURSDAY, A LOW WILL LIFT NORTHEAST JUST OFF SHORE. ANOTHER HIGH WILL BUILD IN RIGHT BEHIND THAT AND REMAIN THE DOMINANT FEATURE THROUGH THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AN AREA OF LOW PRESSURE THAT PULLED A COLD FRONT ACROSS THE AREA OVERNIGHT WILL CONTINUE TO LIFT INTO EASTERN CANADA TODAY, WHILE HIGH PRESSURE ACROSS THE CENTRAL PART OF THE COUNTRY STARTS TO NOSE INTO OUR AREA FROM THE WEST. THIS WILL CREATE GUSTY NORTHWEST WINDS ACROSS THE AREA FOR MUCH OF THE DAY TODAY. DRIER AIR WILL FILTER IN ACROSS THE AREA, ESPECIALLY AS A SECONDARY TROUGH SLIDES ACROSS THE AREA LATER DURING THE DAY. WITH PW VALUES BELOW HALF AN INCH, NO PRECIPITATION IS EXPECTED. THERE WILL BE SOME CLOUD COVER AS THE STRATOCU TO OUR NORTHWEST FILTERS ACROSS THE AREA IN THE NORTHWEST FLOW. TEMPERATURES TODAY WERE A BLEND OF MIXED 925 MB ECMWF TEMPS, MAV/MET MOS, AND MOSGUIDE. OVERALL, HIGHS TODAY ARE EXPECTED TO BE A COUPLE OF DEGREES BELOW NORMAL, ALTHOUGH IT MAY FEEL SLIGHTLY COOLER WITH THE BREEZY CONDITIONS AND LOWERING DEWPOINTS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/... HIGH PRESSURE WILL CONTINUE TO PUSH INTO THE AREA OVERNIGHT. SKIES WILL BEGIN TO CLEAR OUT AFTER SUNSET, AND WIND GUSTS WILL DIMINISH AS WELL. LIGHT WINDS AND MOSTLY CLEAR SKIES WILL LEAD TO GOOD RADIATIONAL COOLING. OVERNIGHT LOWS WERE A BLEND OF MAV/MET MOS AND MOSGUIDE, WHICH BRINGS EVERYONE A FEW DEGREES BELOW NORMAL. TEMPERATURES ARE EXPECTED TO DROP INTO THE UPPER 30S ACROSS THE POCONOS, BUT WE STILL THINK MOST AREAS SHOULD BE WARM ENOUGH TO PREVENT FROST FROM FORMING, ALTHOUGH A FEW ISOLATED SPOTS OF FROST WOULD NOT BE SURPRISING. && .LONG TERM /TUESDAY THROUGH SUNDAY/... TUESDAY INTO WEDNESDAY...THE SURFACE HIGH WILL SLOWLY SLIDE PROPAGATE NORTHEAST AWAY FROM THE REGION. IN THE UPPER LEVELS, THE MAIN UPPER LEVEL TROUGH WILL ALSO BE LIFTING NE TOWARDS THE NORTH ATLANTIC. AS A RESULT EXPECT INCREASING THICKNESSES. THUS, COULD SEE A MODEST WARMING TREND THROUGH THIS PERIOD FROM TEMPERATURES SLIGHTLY BELOW NORMAL ON TUESDAY TO NEAR NORMAL FOR WEDNESDAY. WEDNESDAY NIGHT INTO THURSDAY NIGHT...AS THE UPPER LEVEL TROUGH MOVES OFF OVER THE NEXT FEW DAY, A CUTOFF LOW IS EXPECTED ON THE SOUTHERN END OF THE TROUGH AND THEN DRIFT SE OVER THE CAROLINAS THROUGH MID WEEK. THIS LOOKS TO BE THE START OF THE OFF SHORE SYSTEM THAT COULD AFFECT OUR COASTAL WATERS AND FAR EASTERN ZONES THROUGH THIS PERIOD. MODELS ARE STILL IN POOR AGREEMENT ON THE TRACK OF THIS LOW, AND MODEL AGREEMENT MAY NOT IMPROVE MUCH UNTIL THE CUTOFF LOW DEVELOPS. AT THIS POINT, EXPECT ANY IMPACTS, LIMITED AT THAT, TO BE CONFINED TO DELMARVA AND SOUTHERN AND EASTERN NJ. KEPT POPS IN THIS AREA LIMITED TO SLIGHT CHANCE MENTION WITHE THE TRACK UNCERTAINTY. FRIDAY AND BEYOND...ANOTHER HIGH BUILDS OVER THE REGION BY FRIDAY. THE ASSOCIATED UPPER LEVEL RIDGE IS UNUSUALLY HIGH AMPLITUDE FOR THIS TIME OF YEAR, AS THE CENTER OF THE HIGH BOTH AT THE SURFACE AND IN THE UPPER LEVELS COULD BE NORTH OF THE REGION. THUS, EXPECT THE REGION TO BE UNDER EASTERLY FLOW WHICH COULD SLIGHTLY TEMPER THE WARMING TREND THROUGH THIS PERIOD, BUT SHOULD STILL SEE TEMPERATURES AROUND 5 DEGREES ABOVE NORMAL BY SATURDAY. THE NEXT THING TO WATCH WILL COME AT THE VERY END OF THE PERIOD AS THE GFS AND ECMWF SHOW AN UPPER LEVEL TROUGH DIGGING OUT OF CENTRAL CANADA INTO THE GREAT LAKES REGION TOWARDS THE END OF THE PERIOD. THERE IS STILL CONSIDERABLE UNCERTAINTY WITH THE TRACK AND UNCERTAINTY OF THIS SYSTEM. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. WE EXPECT CONDITIONS TO BE VFR THROUGH THE TAF PERIOD, ALTHOUGH WE EXPECT CLOUD COVER TO INCREASE THIS MORNING THROUGH SUNRISE AS CLOUDS FILTER DOWN ACROSS THE AREA FROM THE NORTHWEST IN THE NORTHWEST FLOW. CIGS ARE EXPECTED TO BE IN THE LOWER END OF THE VFR RANGE, AROUND 3,000-4,000 FEET. CLOUD COVER WILL BEGIN DISSIPATING LATER TODAY INTO THIS EVENING, AND MOSTLY CLEAR SKIES EXPECTED OVERNIGHT. WINDS THAT HAVE NOT BEGUN GUSTING YET WILL BEGIN IN THE NEXT COUPLE OF HOURS THROUGH SUNRISE AND CONTINUE TO BE GUSTY THROUGH TODAY. WIND GUSTS WILL BEGIN TO DIMINISH LATER THIS AFTERNOON/EVENING AND WILL LIGHTEN AS HIGH PRESSURE BUILDS INTO THE AREA TONIGHT, ALTHOUGH THERE SHOULD STILL BE A LIGHT BREEZE OVERNIGHT. OUTLOOK... TUESDAY AND WEDNESDAY...VFR CONDITIONS EXPECTED. THURSDAY...MOSTLY VFR CONDITIONS EXPECTED. THERE IS A SMALL RISK OF CEILINGS INTO THE MVFR RANGE AND MVFR VISIBILITIES WITH BR AND -RA CLOSER TO THE SHORE INCLUDING KACY AND KMIV. FRIDAY...VFR CONDITIONS EXPECTED. && .MARINE... WINDS ARE BEGINNING TO INCREASE AND SHOULD GUST AROUND 25 KNOTS FOR A GOOD PART OF THE DAY. SEAS ARE EXPECTED TO BUILD NOW THE WINDS ARE INCREASING, AND COULD BUILD TO 5 FEET. THEREFORE THE SMALL CRAFT ADVISORY REMAINS ACROSS THE ATLANTIC OCEAN AND LOWER DELAWARE BAY. WE ENDED UP EXTENDING THE ADVISORY A FEW HOURS INTO THE AFTERNOON AS WINDS AND SEAS MAY REMAIN ELEVATED. WINDS AND SEAS ARE EXPECTED TO DIMINISH LATER THIS AFTERNOON INTO THIS EVENING AS HIGH PRESSURE CONTINUES TO BUILD ACROSS THE AREA. OUTLOOK... TUESDAY...WINDS AND SEAS ARE EXPECTED TO BE BELOW SCA CRITERIA. WEDNESDAY AND THURSDAY...WINDS AND SEAS WILL LIKELY INCREASE BY MID DAY WEDNESDAY TO SCA CRITERIA. AT THIS POINT, EXPECT WINDS TO GUST NEAR OR JUST ABOVE 25KT, ESPECIALLY FOR THE COASTAL ZONES ADJACENT TO DE AND SOUTHERN NJ. EXPECT WAVES TO GENERALLY REMAIN IN THE 5 TO 6 FOOT RANGE THROUGH THIS PERIOD. HOWEVER, THERE IS SOME UNCERTAINTY ON THE TRACK OF THIS SYSTEM, AND WAVEWATCH GUIDANCE SHOWS WAVE HEIGHTS UP TO 9 FT THROUGH THIS PERIOD, BUT THIS SEEMS UNLIKELY AS THE PATTERN DOESN`T APPEAR THAT CONDUCIVE FOR SUCH LARGE WAVES AND IT IS CURRENTLY RUNNING A BIT HIGH. FRIDAY...WAVES SHOULD FALL BACK BELOW SCA CRITERIA EARLY IN THE DAY. && .RIP CURRENTS... LOCAL GUIDANCE INDICATES THAT THERE WILL BE A MODERATE RISK OF RIP CURRENTS TODAY INTO TONIGHT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ431- 450>455. && $$ SYNOPSIS...JOHNSON NEAR TERM...ROBERTSON SHORT TERM...ROBERTSON LONG TERM...JOHNSON AVIATION...JOHNSON/ROBERTSON MARINE...JOHNSON/ROBERTSON RIP CURRENTS...ROBERTSON

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