Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPHI 210638 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 238 AM EDT THU MAY 21 2015 .SYNOPSIS...
-- Changed Discussion --
WEAK HIGH PRESSURE PREVAILS OVER THE MID ATLANTIC STATES EARLY TODAY. LOW PRESSURE INN THE CAROLINAS WILL STRENGTHEN AS IT MOVES NORTHEASTWARD OUT TO SEA THIS EVENING. A WEAK COLD FRONT WILL CROSS THE AREA FRIDAY, FOLLOWED BY HIGH PRESSURE RETURNING ACROSS THE REGION FRIDAY NIGHT THROUGH SATURDAY, BEFORE PROGRESSING OFFSHORE SUNDAY. ORGANIZING LOW PRESSURE ACROSS THE CENTRAL UNITED STATES WILL ALLOW A WARM FRONT TO LIFT NORTH THROUGH THE REGION MONDAY, AND A COLD FRONT IS FORECAST TO APPROACH FROM THE WEST TUESDAY.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TODAY/...
-- Changed Discussion --
TODAY...HPC QPF AND 00Z/21 MODEL CONSENSUS HAS THE NORTHERN EDGE OF THE MEASURABLE RAIN TODAY NEAR I-95. THIS 330AM FORECAST THEN TAKES INTO ACCOUNT THE HRRR AS WELL AS THE NARRE THROUGH THIS MORNING. CONFIDENCE ON TEMPS/POPS IS BELOW AVERAGE FROM SE PA ACROSS CENTRAL NJ WHERE GREATEST UNCERTAINTY EXISTS (KPHL-KTTN). NO RAIN IS EXPECTED IN NE PA AND NNJ TODAY. LIGHT WIND WILL BE N-NE THIS MORNING THEN THIS AFTN BECOMES LIGHT SOUTH IN THE NORTH AND REMAINING E-NE ACROSS ACROSS THE SOUTH. WARMEST TEMPS MAY BE IN NNJ TODAY WHERE NO RAIN IS FCST. FCST BASED ON A GENERAL 50 50 BLEND OF 00Z/21 NAM/GFS MOS. CAUSE OF THE RAIN AND CLOUD COVER: INSTABILITY BURST WITH SLY FLOW WAA AHEAD OF A RELATIVELY STRONG 500MB SHORT WAVE MOVING ESEWD FROM THE MIDWEST THIS MORNING AND ARRIVING IN THE UPPER OHIO VALLEY THIS EVENING.
-- End Changed Discussion --
&& .SHORT TERM /TONIGHT/...
-- Changed Discussion --
LEFTOVER RAIN ALONG THE COAST AND A CHANCE OF A PERIOD OF RAIN ELSEWHERE EARLY, THEN CLEARING TOWARD DAWN AS THE RELATIVELY STRONG 500MB SHORT WAVE SEEN AS AN -80M 12 HR HFC PASSES THROUGH E PA REACHING LI BY DAYBREAK FRIDAY. PATCHY FOG POSSIBLE TOWARD DAWN IF IT CLEARS FAST ENOUGH AND IT REMAINS DECOUPLED THROUGH THE NIGHT. LIGHT WIND TREND W-NW OVERNIGHT.
-- End Changed Discussion --
&& .LONG TERM /FRIDAY THROUGH WEDNESDAY/... ANOTHER WEAK SURFACE LOW PRESSURE WILL BE TRACKING TOWARD NORTHERN NEW ENGLAND AND THE CANADIAN MARITIMES THROUGH THE DAYTIME FRIDAY, WITH ITS ASSOCIATED COLD FRONT EXPECTED TO CROSS OUT REGION FRIDAY AFTERNOON TO EVENING. WITH VERY LIMITED MOISTURE, WE HAVE MAINTAINED A DRY FORECAST FRIDAY; ALTHOUGH, WEST- NORTHWEST WINDS WILL PICK UP IN THE WAKE OF THIS FRONT AS THE PRESSURE GRADIENT TIGHTENS FOR A TIME. WINDS THEN RELAX LATER FRIDAY NIGHT AND THROUGH SATURDAY AS AN AREA OF HIGH PRESSURE BUILDS EASTWARD FROM THE MIDWEST STATES. A COOL FRIDAY NIGHT WITH BELOW AVERAGE TEMPERATURES IS ANTICIPATED FOR OUR AREA, WITH CLEARING SKIES AND LIGHT WINDS. OVERNIGHT LOWS WILL RANGE FROM THE LOWER 50S IN THE SOUTHERN DELMARVA TO THE LOWER 40S ACROSS OUR NORTHERN ZONES AND PERHAPS EVEN SOME 30S AND PATCHY FROST INTO THE HIGHER TERRAIN OF THE POCONOS. LIGHT WINDS, AMPLE SUN, AND NEAR AVERAGE MAY TEMPERATURES ARE EXPECTED FOR OUR AREA WITH HIGH PRESSURE PASSING OVER THE REGION SATURDAY. WHILE SUNDAY WILL STILL BE PLEASANT, TEMPERATURES AND DEWPOINTS WILL BE CREEPING UPWARD A FEW DEGREES AS THE AREA OF HIGH PRESSURE EASES OFFSHORE AND A RETURN SOUTHWESTERLY FLOW SETS UP OVER THE REGION. THIS WARMING TREND AND GRADUAL INCREASE IN DEWPOINTS WILL CONTINUE THEN INTO MONDAY AS AN AREA OF LOW PRESSURE IS FORECAST TO ORGANIZE OVER THE CENTRAL UNITED STATES, WITH ITS ASSOCIATED WARM FRONT LIFTING NORTH THROUGH THE OHIO VALLEY AND OUR REGION MONDAY. THERE SHOULD BE ENOUGH LIFT AND INSTABILITY AS THIS BOUNDARY PASSES NORTH FOR SOME SCATTERED SHWR/TSTORM ACTIVITY ACROSS OUR REGION, AND WE HAVE KEPT CHANCE POPS IN PLACE FOR MEMORIAL DAY, SOMEWHAT HIGHER CHANCES FOR THE NORTHERN TWO-THIRDS OF THE FORECAST AREA. A MORE NOTICEABLE INCREASE IN WARMTH AND HUMIDITY IS THEN EXPECTED GOING INTO TUESDAY AS OUR REGION WILL BE IN THE WARM SECTOR, WITH THE SURFACE LOW AND WARM FRONT TO OUR NORTH. BUILDING INSTABILITY AND A COLD FRONT APPROACHING FROM THE WEST WILL YIELD MORE SCATTERED SHWR/TSTORM POTENTIAL, AND WE KEPT SOME CHANCE POPS IN PLACE THROUGH THIS TIMEFRAME. DAYTIME TEMPERATURES SHOULD EASILY REACH INTO THE MIDDLE AND UPPER 80S FROM THE DELAWARE VALLEY INTO THE DELMARVA, WITH SOMEWHAT COOLER UPPER 70S/LOW 80S FARTHER NORTH AND ALONG THE COAST. A LITTLE MORE UNCERTAINTY EXISTS INTO WEDNESDAY WITH REGARDS TO ISOLATED/SCATTERED PRECIP POTENTIAL DEPENDING ON THE PROGRESS OF THE FRONTAL BOUNDARY, AND FOR NOW, WE INTRODUCED SOME VERY LOW POPS INTO THE FORECAST FOR THE WEDNESDAY TIMEFRAME. && .AVIATION /06Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THROUGH 12Z...VFR. AREAS OF CIGS AOA 20000 FT LOWER TO NEAR 10000 FT AT 12Z. WIND NNW BECOMING NNE WITH GUSTS 10-15 KT FROM THE I-95 CORRIDOR EASTWARD INCLUDING KPHL GROUP OF TAFS. AFTER 12Z TODAY...VFR CIGS. LIGHT RAIN IS FORECAST TO SPREAD INTO OUR REGION FROM THE WEST AND SOUTHWEST AROUND 1500Z. THE RAIN IS EXPECTED TO REMAIN SOUTH OF KRDG AND KABE. A PERIOD OF LIGHT RAIN IS ANTICIPATED FOR KILG, KPHL, KPNE AND KTTN DURING THE AFTN WITH THE CATEGORICAL RAIN PROBABILITY RESTRICTED TO KILG. CONDITIONS SHOULD REMAIN IN THE VFR CATEGORY AT THOSE LOCATIONS WITH CEILINGS STAYING ABOVE 3000 FEET AND VISIBILITY VALUES STAYING ABOVE 5 MILES. THE RAIN IS FORECAST TO HAVE A GREATER IMPACT ON KMIV AND KACY THAN ON OUR TAF SITES TO THE NORTH. CONDITIONS MAY DROP TO MVFR AT KMIV AND KACY THIS THURSDAY AFTERNOON. AFTER THIS MORNINGS LIGHT NE WIND TO START, A LIGHT SOUTHWEST WIND MAY DEVELOP AT KRDG, KABE, KTTN, KPNE, KPHL AND KILG DURING MIDDAY. THE WIND MAY REMAIN VARIABLE AT KMIV AND KACY OR IT COULD RESETTLE INTO THE NORTHEAST OR EAST DURING THE AFTERNOON HOURS AT THOSE LOCATIONS. TONIGHT...MOSTLY VFR CIGS; ALTHOUGH, SOME LINGERING RAIN/SHWRS MAY MEAN SOME SUB-VFR THROUGH THE FIRST PART OF THE NIGHT MAINLY FROM AROUND KMIV/KACY AND SOUTH. LIGHT WIND TREND W-NW OVERNIGHT. OUTLOOK... FRIDAY...VFR CONDITIONS ARE EXPECTED WITH WEST-NORTHWEST WINDS GUSTING TO AROUND 20 KNOTS DURING THE AFTERNOON. SATURDAY...CONTINUED VFR WITH LIGHT NORTHWEST WINDS. SUNDAY...VFR CONDITIONS WITH SOUTHWEST WINDS 10 TO 15 KNOTS. MONDAY...MAINLY VFR WITH LIGHT SOUTHWEST WINDS; ALTHOUGH, SOME SCATTERED SHWRS/TSTORMS AND SUB-VFR POSSIBLE AT TIMES.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
SAFE BOATING WEEK CONTINUES THROUGH FRIDAY MORNING. THERE IS A NEW USCG SAFETY APP THAT SHOULD BE OF VALUE TO MARINERS AND WAS JUST UNVEILED THIS WEEK: HTTP:/WWW.USCG.MIL/MOBILE THIS APP PROVIDES ADDITIONAL SAFE BOATING RESOURCES FOR MOBILE DEVICE USERS. WHEN LOCATION ENABLED, USERS CAN RECEIVE THE LATEST WEATHER REPORTS FROM THE CLOSEST NOAA BUOY AS WELL AS REPORT THE LOCATION OF A HAZARD ON THE WATER. IT FEATURES AN EMERGENCY ASSISTANCE BUTTON, WHICH CAN CALL THE CLOSEST CG COMMAND CENTER. THE FORECAST: ISSUING SCA FOR THE DE BAY ATLC WATERS TONIGHT. NCAROLINA LOW INTENSIFIES IN ITS DEPARTURE AND SHOULD DEVELOP MARGINAL 5 FT HAZARDOUS SEAS AND A FEW SCA GUSTS AROUND 25 KT OVERNIGHT NEAR 44009. OTHERWISE NO MARINE HEADLINE ANTICIPATED THROUGH TONIGHT. NORTHERLY WINDS EARLY TODAY TEND NORTHEAST NORTHEAST-EAST BY DAYBREAK THEN ONSHORE SOUTHEAST THIS AFTERNOON. WINDS EVENTUALLY BECOMING NORTHWEST EVERYWHERE LATER THIS THURSDAY NIGHT. OUTLOOK... FRIDAY...WHILE WE HAVE NO HEADLINE ANTICIPATED AT THIS TIME THERE IS SMALL POTENTIAL FOR AN SCA WEST-NORTHWEST FLOW LATE FRIDAY OR FRIDAY NIGHT. SATURDAY AND SUNDAY...CONTINUED SUB-ADVISORY CONDITIONS; ALTHOUGH, SOME WIND GUSTS TO AROUND 20 KNOTS STILL POSSIBLE AT TIMES. MONDAY...SUB-ADVISORY ANTICIPATED AT THIS TIME. SOME SCATTERED SHWRS/TSTORMS EXPECTED WITH LOCALLY HIGHER WINDS/SEAS NEAR TSTORMS.
-- End Changed Discussion --
&& .FIRE WEATHER... FOR FRIDAY AFTERNOON, THERE MAY BE THE RISK FOR ENHANCED WILDFIRE SPREAD AS A WEST-NORTHWESTERLY WIND GUSTS TO BETWEEN 20 TO 25 MPH AT TIMES. IN ADDITION, THIS WILL COMBINE WITH RELATIVE HUMIDITY VALUES NEARING 30 PERCENT IN SOME AREAS ALONG WITH DRY FINE FUELS. && .RIP CURRENTS... SST`S ABOVE NORMAL AND JUST OFF THE COAST SSTS WELL ABOVE NORMAL BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS HOT AND BEACHES ARE UNGUARDED, SWIMMERS MAY TAKE CHANCES AT UNGUARDED LOCATIONS. BE SMART ABOUT ANY SWIMMING EARLY THIS SEASON. ATLANTIC COASTAL WATER TEMPS ARE WARMING --UPPER 50S TO MID 60S. RIP CURRENT AWARENESS WEEK FOR MT HOLLY IS JUNE 7-13 WITH PSAS VIA PUBLIC INFORMATION STATEMENTS, SOCIAL MEDIA, NOAA WEATHER RADIO AND ANY MEDIA INTERVIEWS DESIRED (CONTACT OFFICE). FOR RIP CURRENTS: DESPITE ANTICIPATED PROJECTIONS OF LOW OR MODERATE RISK THROUGH THE MEMORIAL DAY WEEKEND, EARLY SEASON FATALITIES OCCUR WHEN SWIMMING AT UNGUARDED TIMES/LOCATIONS. WEAKER SWIMMERS OR SWIMMING IN AREAS WHERE RIP CURRENTS ARE STRONGER (JETTIES) CAN QUICKLY BECOME LIFE THREATENING. WHEN TRAINED LIFEGUARDS ARE NOT NEARBY, TIMELY RESCUE IS MUCH LESS LIKELY. LETS GET THROUGH THE MONTH OF MAY WITH ALL SWIMMERS SAFE! SWIM IN THE PRESENCE OF LIFE GUARDS! THANK YOU. && .CLIMATE...
-- Changed Discussion --
**TOP 10 WARMEST MAY CONTINUES LIKELY IN PORTIONS OF THE FORECAST AREA** THE FIRST 19 DAYS OF MAY IN OUR FORECAST AREA WERE AVERAGING WITHIN ABOUT 1/2 DEGREE OF 7 DEGREES ABOVE NORMAL. BASED ON THE ENSEMBLE AND A FORECAST THAT IS DETERMINISTICALLY CONSERVATIVE INCLUDING OUR 330 PM MAY 20 PROJECTIONS THROUGH THE 27TH AND THEN THE 00Z/21 CONSERVATIVE FTPRHA THEREAFTER THROUGH THE 31ST...EASILY OUTLOOKS A TOP 10 WARMEST MAY ON RECORD. FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN AVG TEMP OF 68.7 TO 69.3 OR AROUND 5 DEGREES ABOVE NORMAL AND AT THE LEAST, 3RD WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN 69.2 2004. FOR ALLENTOWN...POR TO 1922. YESTERDAY WE WERE PROJECTING 65.0 OR 5.1 DEGREES ABOVE NORMAL AND 8TH WARMEST ON RECORD. WARMEST WAS 67.2 IN 1991. POSTED BECAUSE WE`RE EXPECTING OUR FIRST 90 IN PHILADELPHIA BY THE MIDDLE OF NEXT WEEK. NORMAL FIRST DATE OF 90 OR HIGHER. PHILADELPHIA MAY 29 ALLENTOWN MAY 30 WILMINGTON JUNE 4 ATLANTIC CITY JUNE 11.
-- End Changed Discussion --
&& .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...KLINE/DRAG 238 NEAR TERM...DRAG 238 SHORT TERM...DRAG 238 LONG TERM...KLINE AVIATION...DRAG/KLINE 238 MARINE...DRAG/KLINE 238 FIRE WEATHER... RIP CURRENTS... CLIMATE...238

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.