Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 020756 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 356 AM EDT THU OCT 2 2014 .SYNOPSIS... HIGH PRESSURE OVER THE CANADIAN MARITIMES WILL INFLUENCE OUR WEATHER THROUGH FRIDAY. THEN, A STRONG COLD FRONT, ASSOCIATED WITH POTENT LOW PRESSURE IN ONTARIO, WILL MOVE ACROSS THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. BEHIND THE FRONT, HIGH PRESSURE WILL BUILD TO THE SOUTH AND EAST THROUGH MONDAY, THEN A SERIES OF IMPULSES LOOK TO AFFECT THE REGION THROUGH AT LEAST MIDWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... OVERNIGHT WATER VAPOR LOOP SHOWS A WELL-DEFINED SPIN IN THE ATMOSPHERE THAT IS ASSOCIATED WITH AN UPPER-LEVEL LOW OVER SOUTHERN NEW ENGLAND. THE LOW IS FORECAST TO MOVE OFFSHORE TODAY. MARINE LAYER AND STRATOCU HAS BEEN ESTABLISHED ACROSS THE REGION OVER THE PAST 30 HOURS AS A PERSISTENT NORTHEASTERLY FLOW AROUND THE LOW HAS DRAWN COOL/MOIST AIR FROM THE ATLANTIC MOISTURE INLAND. THESE CLOUDS ARE EXPECTED TO LINGER OVER THE AREA ONCE AGAIN TODAY. THERE SHOULD BE AN OPPORTUNITY TO SEE MORE APPRECIABLE BREAKS IN THE CLOUDS, PARTICULARLY SOUTH AND WEST OF PHILLY LATER THIS MORNING. HOWEVER, DEEPER MIXING AT THESE SUNNIER LOCATIONS WILL RESULT IN REDEVELOPMENT OF STRATOCU DURING THE AFTERNOON. THE BULK OF THE LIFT WITH THE LOW WILL STAY OFFSHORE AND OVER NEW ENGLAND, BUT A BRIEF PERIOD OF LIGHT RAIN OR DRIZZLE CERTAINLY POSSIBLE EARLY THIS MORNING NEAR THE COAST. ANY LINGERING PRECIP NEAR THE COAST WILL SHIFT OFFSHORE BY MID MORNING AS THE UPPER LOW PULLS AWAY FROM THE AREA. FORECAST MAX TEMPS ARE IN THE 70S TODAY EXCEPT FOR THE UPPER 60S ALONG THE NJ COAST (WHERE THICKER CLOUD COVER WILL LIMIT DAYTIME HEATING) AND IN THE HIGHER ELEVATIONS OF NW NJ AND THE POCONOS. LEANED TOWARD THE WARMER MET GUIDANCE FOR PHILLY AND POINTS SOUTH AND WEST (WHERE LESS CLOUD COVER WOULD ALLOW FOR HIGHS TO REACH THE MID 70S). && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... THE UPPER LOW PULLS FARTHER AWAY FROM THE COAST TONIGHT. RIDGE BUILDING WILL OCCUR ALONG THE EASTERN SEABOARD. CONDITIONS WILL BE FAVORABLE FOR RADIATIONAL FOG TO DEVELOP OVER THE LEHIGH VALLEY AND WESTERN SUBURBS OF PHILLY WHERE THE SFC-925 MB RIDGE AXIS IS FORECAST TO BE POSITIONED OVERHEAD. DOWNSTREAM OF THIS LOW-LEVEL RIDGE AXIS, MARINE LAYER WILL REMAIN ESTABLISHED UNDER LIGHT EASTERLY FLOW. ACCORDINGLY, COASTAL LOCATIONS HAVE THE BEST CHANCE OF SEEING STRATUS RETURN LATE TONIGHT. FORECAST MIN TEMPS RANGE FROM THE UPPER 40S IN HIGHER ELEVATIONS OF NORTHWEST NJ/NORTHEAST PA TO NEAR 60S ALONG THE NJ AND DE COAST. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... HIGH PRES OVER ERN CANADA WILL RIDGE DOWN WWD ON FRI AND THIS FEATURE COUPLED WITH LOW PRES OVER THE OPEN ATLC WILL KEEP ELY FLOW OVER THE REGION. AS THIS TAKES PLACE, A STRONG AREA OF LOW PRESSURE WILL BE DEVELOPING NR THE GRTLKS AND MOVG INTO ONTARIO. THE MDLS STILL DIFFER A BIT IN THE DETAILS OF THE EVOLUTION OF THE LOW WITH ITS ULTIMATE PLACEMENT AND STRENGTH, BUT AGREE ON THE OVERALL LARGE-SCALE PATTERN. THE POTENT CDFNT ASSOCD WITH THIS LOW WILL EXTEND FAR S FROM THIS LOW AND WILL WORK ITS WAY FROM W TO E FROM FRI NIGHT INTO SAT. FRI DURG THE DAY SHUD BE DRY WITH PRECIP STILL TO THE W. DURG THE EVE HOURS PRECIP WILL BEGIN TO MOVE IN FROM THE W AND BY DAYBREAK SAT PRECIP CHCS WILL EXIST EVERYWHERE, WITH THE BEST CHCS FROM THE I-95 CORRIDOR N AND W. THERE IS VERY GOOD DYNAMICS WITH THIS FRONT AND NEG TILTED TROF AND THE GLFMEX IS OPEN SO THE THREAT OF HVY RAIN IS THERE. HOWEVER, ANTECEDENT CONDS HAVE BEEN DRY. DURG THE MRNG HOURS OF SAT SEEMS TO BE THE BEST SHOT OF RAIN FOR MOST OF US, WITH THE CFP LATE MRNG ERLY AFTN DEPENDING ON LOCATION, AND PRECIP COMING TO AND END BEHIND THE FROPA FROM SW TO NE. THE SECOND HALF OF SAT SHOULD BE BETTER THAN THE FIRST. THEN SAT NIGHT THRU MON LOOKS DRY AS HIGH PRES BUILDS IN FROM THE S AND SPREADS NEWD. STRONG CAA MOVES IN SAT NIGHT BEHIND THE FRONT AND IT WILL BE A BIT BREEZY. WE WILL HAVE OUR FIRST TRUE TOUCH OF FALL WITH TEMPS NOT HITTING 60 IN MANY AREAS ON SUN AND ANY WIND MAKING IT FEEL COOLER. THE WIND SHUD DECREASE DURG THE DAY. BEYOND MON, A SERIES OF DISTURBANCES WILL BRING SOME ADDITIONAL SHOTS OF PRECIP THRU MIDWEEK WITH THE MDLS DIFFERING ON THE S/WV DETAILS WHICH ARE NEARLY IMPOSSIBLE TO RESOLVE AT THIS TIME SCALE. DID NOT MAKE ANY CHANGES TO THE EXTENDD BEYOND MON NIGHT AS THE ECMWF WAS DELAYED IN ITS ARRIVAL, AND COULD NOT ANALYZE IT IN TIME FOR THE FCST ISSUANCE. TEMPS WILL START OUT NR NRML AND END NR NRML AFTER A SIGNIFICANT DROP WITH THE CFP OVER THE WKND. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. MARINE STRATOCU PERSISTS OVER THE REGION EARLY THIS MORNING. CIGS HAVE TAKEN A BIT LONGER TO LOWER TO MVFR SOUTH AND WEST OF ABE-TTN. STILL EXPECT MVFR CIGS TO DEVELOP AT ALL TERMINALS BY 09Z. CIGS AROUND 2-3 KFT SHOULD SLOWLY IMPROVE TO VFR BETWEEN 14-17Z ALTHOUGH MVFR MAY CONTINUE WELL INTO THE AFTN AT ACY WHERE MARINE LAYER IS MOST ESTABLISHED. N-NE WINDS AROUND 5 KT AT SUNRISE WILL INCREASE TO AROUND 10 KT THIS AFTN. VFR EXPECTED THIS EVE. THERE IS A POTENTIAL FOR FOG AND LOW CLOUDS TO DEVELOP AGAIN BETWEEN 06Z-12Z FRIDAY. FOR THE 06Z TAFS, KEPT FLIGHT RESTRICTIONS ABOVE IFR FOR NOW AT KPHL SINCE THE END OF THE 30-HR FORECAST COVERS THIS TIME WINDOW. OUTLOOK... FRI...MOSTLY VFR. HIGH CONFIDENCE. FRI NIGHT...INCREASING RAIN CHANCES FROM W TO E AND MVFR/IFR IN PERIODS OF RAIN, SOME OF IT HEAVY. E TO SE WIND. MDT TO HIGH CONFIDENCE. SAT...MVFR/IFR EARLY IN RAIN, SOME OF IT HEAVY, THEN BECOMING VFR WITH RAIN ENDING FROM SW TO NE. CFP AND WSHFT FROM E TO WNW. MDT CONFIDENCE. SUN-MON...VFR. GUSTY NW WIND SUN. HIGH CONFIDENCE. && .MARINE... HERE WAS A CHANGE TO THE HEADLINE FOR TODAY AND TONIGHT, CONVERTING THE SMALL CRAFT ADVISORY INTO A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS. WINDS WILL BE BELOW 25 KT DURING THIS TIME BUT SEAS WILL CONTINUE TO BUILD TO 5-6 FT. OUTLOOK... FRI...SCA CONDS WILL LIKELY PERSIST ON OUR WATERS THROUGH THE DAY AND SCA HAS BEEN EXTENDD TO ACCOUNT FOR THIS AS PERSISTENT SELY FLOW CONTINUES. SEAS WILL CONTINUE TO RUN AROUND 5 FEET. COULD BE MARGINAL. SAT...STRONG CFP. WSHFT BACK TOWARDS THE WNW LATER IN THE DAY BEHIND THE FROPA. A GUSTY WIND IS EXPECTED IN ADVANCE OF THE FRONT, THEN THERE COULD BE A BRIEF LULL BEFORE THE Y PICK UP AGAIN BEHIND THE FRONT IN THE CAA. SCA SEEMS LIKELY. GUSTY WINDS ALSO PSBL IN THE HEAVIER RAIN SHOWERS...MOSTLY IN THE MORNING. SUN...GUSTY NW WIND WILL CONTINUE BEFORE SUBSIDING DURG THE MRNG. SEAS SHOULD ALSO DROP BELOW SCA CONDS TO AROUND 3-4 FEET. MON...NO MARINE HEADLINES ANTICIPATED. && .TIDES/COASTAL FLOODING... PERSISTENT NORTHEAST WINDS HAVE RESULTED IN POSITIVE TIDAL DEPARTURES BETWEEN 1-1.25 FT. DO NOT EXPECT ANOMALIES TO INCREASE MUCH TODAY AS THE ONSHORE WINDS SUBSIDE A BIT. THIS SHOULD RESULT IN TIDES BELOW MINOR FLOODING THRESHOLD FOR THIS MORNING`S AND TONIGHT`S HIGH TIDE CYCLES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT FRIDAY FOR ANZ450>455. && $$ SYNOPSIS...NIERENBERG NEAR TERM...KLEIN SHORT TERM...KLEIN LONG TERM...NIERENBERG AVIATION...KLEIN/NIERENBERG MARINE...KLEIN/NIERENBERG TIDES/COASTAL FLOODING...KLEIN

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