Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 201507 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1107 AM EDT MON APR 20 2015 .SYNOPSIS... LOW PRESSURE LOCATED OVER THE GREAT LAKES EARLY THIS MORNING WILL CONTINUE TO MOVE NORTHWARD. THE LOW IS FORECAST TO PULL A WARM FRONT FROM THE SOUTH INTO OUR REGION TODAY FOLLOWED BY A COLD FRONT FROM THE WEST LATE TONIGHT. HIGH PRESSURE IS EXPECTED TO EDGE NORTHWARD INTO OUR REGION FOR TUESDAY INTO WEDNESDAY BEFORE ANOTHER COLD FRONT FROM THE NORTHWEST ARRIVES ON WEDNESDAY NIGHT. A SECONDARY COLD FRONT IS ANTICIPATED FOR LATE THURSDAY. HIGH PRESSURE SHOULD BUILD INTO OUR REGION GRADUALLY FROM THE NORTHWEST AND WEST DURING FRIDAY AND THE COMING WEEKEND AS STRONG LOW PRESSURE MEANDERS OFF THE SOUTHEAST COAST OF CANADA. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE WARM FRONT IS IN THE PROCESS OF TRACKING ACROSS THE AREA. THE DECENT SURGE OF SE/E WINDS AHEAD OF THE FRONT ARE BEING REPLACED WITH A LIGHTER WIND MOSTLY FROM THE S BEHIND IT. THE BACK EDGE OF THE STEADY RAINS ARE MOVING UP INTO THE SOUTHERN POCONOS AND NE NJ ATTM. BREAKS IN THE CLOUDS ARE BEING OBSERVED BY VIS SAT ACROSS MD/NRN VA. WE EXPECT BREAKS TO DEVELOP IN THE CLOUDS ACROSS THE SRN HALF OF THE AREA THIS AFTERNOON. SPC HAS UPDATED THE DAY1 OUTLOOK TO INCLUDE MUCH OF OUR CWA IN AN ENHANCED THREAT FOR SVR WEATHER. THIS SUGGESTS THAT THE AIRMASS WILL HEAT SUFFICIENTLY THIS AFTERNOON TO REALIZE SOME DECENT CAPE VALUES (OVER 2000 J/KG ON THE 06Z NAM FOR THE DEL VALLEY). THIS CAPE COMBINED WITH SOME MODELS LOW LEVEL WINDS/SHEAR WILL LIKELY ORGANIZE SOME SVR WEATHER FOR PARTS OF THE AREA. STAY UPDATED WITH THE LATEST THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/... THE COLD FRONT WILL BE APPROACHING THE AREA FROM THE WEST DURING THE EARLY EVENING, AND PROGRESS ACROSS THE AREA OVERNIGHT. WE EXPECT A LINE OF SHOWERS, WITH ISOLATED THUNDERSTORMS TO HAVE DEVELOPED TO OUR WEST DURING THE DAY ALONG AND AHEAD OF THE BOUNDARY. THESE SHOWERS WILL PROGRESS EASTWARD THROUGH THE EVENING AND INTO THE OVERNIGHT HOURS AS THE FRONT MOVES THROUGH. ALL SHOWER ACTIVITY IS EXPECTED TO HAVE MOVED TO OUR EAST BY SUNRISE TUESDAY. && .LONG TERM /TUESDAY THROUGH SUNDAY/... A MID LEVEL LOW IS FORECAST TO BE LOCATED OVER LAKE SUPERIOR ON TUESDAY MORNING WITH A BROAD LONG WAVE TROUGH AFFECTING MUCH OF THE CENTRAL AND EASTERN PARTS OF THE COUNTRY. THE MID LEVEL LOW IS EXPECTED TO DRIFT EASTWARD AND IT SHOULD PASS OFF THE COAST OF NEW ENGLAND AND CANADA`S MARITIME PROVINCES ON FRIDAY AND FRIDAY NIGHT. WHILE THERE CONTINUES TO BE A SPREAD IN THE MODEL SOLUTIONS FOR THE WEEKEND, THE OVERALL TRENDS KEEP US UNDER THE INFLUENCE OF THE BROAD MID LEVEL TROUGH THROUGH THE BALANCE OF THE LONG TERM PERIOD. THE FORECAST PATTERN SHOULD RESULT IN A RETURN TO BELOW NORMAL TEMPERATURES. AFTERNOON READINGS SHOULD BE ABOUT 10 DEGREES BELOW NORMAL FOR THE PERIOD FROM THURSDAY THROUGH SUNDAY. THERE IS THE POTENTIAL FOR FROST, ESPECIALLY DURING THE EARLY MORNING HOURS OF SATURDAY WHEN A MOSTLY CLEAR SKY AND A RELATIVELY LIGHT WIND ARE ANTICIPATED. THERE IS A CHANCE OF SHOWERS ON TUESDAY AFTERNOON IN OUR NORTHWESTERN COUNTIES AS A MID LEVEL SHORT WAVE TROUGH LIFTS NORTHEASTWARD OVER OUR REGION. A COLD FRONT IS FORECAST TO APPROACH FROM THE NORTHWEST ON WEDNESDAY AND IT SHOULD PASS THROUGH OUR REGION ON WEDNESDAY NIGHT. AS A RESULT, WE WILL MENTION A CHANCE OF SHOWERS THROUGHOUT OUR REGION FOR THAT PERIOD OF TIME. THERE IS THE POTENTIAL FOR SOME SNOW FLAKES TOWARD THE END OF THE PRECIPITATION EVENT IN THE ELEVATED TERRAIN UP NORTH. A SECONDARY COLD FRONT IS EXPECTED TO ARRIVE LATE ON THURSDAY BUT IT SHOULD HAVE LIMITED MOISTURE ASSOCIATED WITH IT. WE HAVE MENTIONED ONLY A LOW OR SLIGHT CHANCE OF SHOWERS FOR OUR NORTHWESTERN COUNTIES. SURFACE HIGH PRESSURE IS ANTICIPATED TO GRADUALLY WORK ITS WAY INTO OUR REGION FROM THE NORTHWEST AND WEST FOR FRIDAY AND THE WEEKEND. WE HAVE NOT MENTIONED ANY PRECIPITATION FOR THE PERIOD FROM FRIDAY THROUGH SUNDAY. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. IMPROVEMENT...SLOW IMPROVEMENT...FROM SW TO NE THIS AFTERNOON AS THE WARM FRONT TRACKS ACROSS THE AREA. LOW CONFID IN WHAT WILL HAPPEN RE: CIGS ONCE THE FRONT PASSES. VFR WITH SCT CLOUDS POSSIBLE ACCORDING TO SOME OF THE RECENT GUIDANCE. THE SE FLOW WILL LIKELY PROMOTE SOME CIGS ACROSS KACY WITH THE COLD WATER OFFSHORE. VARIABLE CONDITIONS ELSEWHERE WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE. FRQ AMDS EXPECTED FOR ALL TAFS THIS AFTERNOON. LOWER CONDITIONS AND A CHANCE FOR ISOLATED THUNDERSTORMS LATER THIS AFTERNOON SOUTH OF THE WARM FRONT, BUT CONFIDENCE ON WHEN/WHERE THEY OCCUR IS STILL LOW SO WE DID NOT INCLUDE THEM. ADDITIONAL SHOWERS ARE EXPECTED LATER THIS EVENING INTO THE OVERNIGHT HOURS AS A COLD FRONT APPROACHES AND MOVES ACROSS THE AREA. AGAIN, THERE MAY BE SOME THUNDERSTORMS ASSOCIATED WITH THE FRONT, BUT CONFIDENCE IS LOW SO WE DID NOT INCLUDE THEM. GUSTY EASTERLY WINDS WILL CONTINUE THROUGH THE MORNING HOURS. AS THE WARM FRONT LIFTS INTO THE AREA LATER THIS MORNING INTO THE AFTERNOON, WINDS WILL BECOME MORE SOUTHERLY. BEHIND THE COLD FRONT LATER TONIGHT, WINDS WILL SWING AROUND TO THE WEST AND BECOME GUSTY ONE AGAIN. WE HAVE KEPT LLWS IN THE TAFS FOR THE MORNING HOURS AS THERE REMAINS 50-55 KT WINDS AROUND 1,000-2,000 FEET. OUTLOOK... TUESDAY AND TUESDAY NIGHT...MAINLY VFR. WEDNESDAY AND WEDNESDAY NIGHT...MAINLY VFR. HOWEVER, SCATTERED RAIN SHOWERS MAY REDUCE CEILING AND VISIBILITY VALUES INTO THE MVFR RANGE AT TIMES. THURSDAY THROUGH FRIDAY...MAINLY VFR. && .MARINE... SMALL CRAFT ADVISORY REMAIN ACROSS THE OCEAN WATERS AND FOR DEL BAY AS GUSTY EAST TO SOUTHEAST WINDS REMAIN. AS THE WARM FRONT LIFTS INTO THE AREA, WINDS SHOULD BECOME MORE SOUTHERLY THIS AFTERNOON. A COLD FRONT WILL MOVE ACROSS THE WATERS OVERNIGHT TONIGHT, SO WINDS WILL BECOME MORE WESTERLY BY TUESDAY MORNING. SEAS WILL CONTINUE TO BUILD TO AROUND 9 FEET THROUGH THIS MORNING, AND REMAIN ELEVATED THROUGH TONIGHT. OUTLOOK... TUESDAY...A SMALL CRAFT ADVISORY IS IN EFFECT FOR OUR OCEAN WATERS FOR WAVE HEIGHTS OF 5 TO 6 FEET AND THE POTENTIAL FOR LINGERING WIND GUSTS NEAR 25 KNOTS. TUESDAY NIGHT THROUGH THURSDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED. FRIDAY...A SMALL CRAFT ADVISORY MAY BE NEEDED FOR GUSTY NORTHWEST WINDS. && .TIDES/COASTAL FLOODING... SOME LOW END MINOR TIDAL FLOODING THIS MORNING ACROSS NRN NJ SHORE AREAS. CONDITIONS FOR FURTHER TIDAL FLOODING DECREASING SINCE THE WINDS BECOMING MORE OFFSHORE LATER TODAY. WE WILL CONTINUE TO MONITOR. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ430-431. && $$ SYNOPSIS...IOVINO NEAR TERM...PO SHORT TERM...ROBERTSON LONG TERM...IOVINO AVIATION...IOVINO/ROBERTSON/PO MARINE...IOVINO/ROBERTSON TIDES/COASTAL FLOODING...PO

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