Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | 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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPHI 211155 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 655 AM EST FRI NOV 21 2014 .SYNOPSIS... STRONG HIGH PRESSURE FROM THE LOWER OHIO VALLEY WILL BUILD INTO OUR AREA TODAY THROUGH SATURDAY. THE HIGH WILL MOVE OFFSHORE SATURDAY NIGHT. A WARM FRONT WILL LIFT ACROSS OUR AREA SUNDAY NIGHT AND MONDAY AS A STRONG LOW PRESSURE SYSTEM TRACKS INTO THE GREAT LAKES REGION. A COLD FRONT IS FORECAST TO MOVE THROUGH LATER MONDAY NIGHT AND TUESDAY, FOLLOWED BY HIGH PRESSURE LATE WEDNESDAY AND THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A 1030 MB SURFACE HIGH WAS CENTERED OVER THE MIDWEST OVERNIGHT WHILE THE COLD FRONT THAT MOVED THROUGH THE CWA YESTERDAY WAS LOCATED OFF THE NORTHEAST COAST AND THE SOUTHERN MID-ATLANTIC STATES. THE LATEST WATER VAPOR SATELLITE LOOP CAPTURES A POLAR TROUGH DIGGING INTO THE GREAT LAKES AND NORTHEAST STATES. WEST-NORTHWEST FLOW AROUND THE BASE OF THE TROUGH WILL CONTINUE TO USHER IN COLD AIR THIS MORNING. THE END RESULT WILL BE DAY 3 THIS WEEK OF WINTER-LIKE TEMPERATURES FOR THE FORECAST AREA. FORECAST SOUNDINGS FROM THE LATEST MODEL GUIDANCE SHOWS A DEEP MIXED LAYER AROUND 4-5 KFT THIS AFTERNOON. FORECAST 850 MB TEMPS OF AROUND -14C TODAY, WHICH WOULD BE 1 TO 2C HIGHER THAN IT WAS THIS PAST TUESDAY-WEDNESDAY, WAS A REASONABLE PROXY FOR DETERMINING FULL HEATING POTENTIAL. THIS TRANSLATES TO HIGHS IN THE MID 30S (EXCEPT MID TO UPPER 20S IN THE MOUNTAINS). WINDS WILL BE BREEZY THIS MORNING WITH 20-30 MPH GUSTS BEFORE IT GRADUALLY RELAXES THIS AFTERNOON AS HIGH PRESSURE BUILDS INTO THE AREA. BOUNDARY-LAYER FLOW WILL VEER SLIGHTLY OUT OF THE NORTHWEST EARLY THIS MORNING, CAUSING A LAKE EFFECT SNOW BAND NEAR BGM TO SHIFT SOUTHWARD. IF IT IS ABLE TO MAINTAIN ITSELF ENOUGH DOWNWIND, THE POCONOS AND THE NORTHWESTERN TIP OF SUSSEX COUNTY MAY SEE A FEW FLURRIES THIS MORNING. LITTLE OR NO ACCUMULATION IS EXPECTED. THERE MAY ALREADY BE FLURRIES OCCURRING BUT THE RADAR WOULD OVERSHOOT ANY OF THESE SNOW SHOWERS OR FLURRIES IN OUR FAR NORTHWEST ZONES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... HIGH PRESSURE WILL BUILD SOUTHEASTWARD TONIGHT WITH THE CENTER OF THE HIGH SETTLING OVER THE SOUTHERN MID-ATLANTIC STATES. WAA WILL OCCUR OVERHEAD TONIGHT AS THE 925-850 MB RIDGE BUILDS EASTWARD. DO NOT EXPECT THE WARM AIR ALOFT TO HAVE MUCH OF AN IMPACT ON SURFACE TEMPS AS THE BOUNDARY LAYER DECOUPLES UNDER A GOOD RADIATIONAL COOLING SETUP. MIN TEMP FORECAST WEIGHTED MORE TOWARD THE COLDER MAV GUIDANCE. TEMPS ARE EXPECTED TO BOTTOM OUT IN THE MID TO UPPER TEENS IN THE MORE RURAL AREAS AND LOW TO MID 20S IN THE URBAN AND COASTAL LOCALES. && .LONG TERM /SATURDAY THROUGH THURSDAY/... THE WEATHER PATTERNS CHANGE SOMEWHAT ACROSS THE REGION DURING THE LONGER TERM PARTS OF THE FCST. THE MEAN TROUGH ACROSS NORTH AMERICA REMAINS...BUT THE COLDEST AIR MOVES AWAY SAT/EARLY SUN AS SOME PROGRESSIVE RIDGING MOVES ACROSS THE ERN U.S. MORE COLDER AIR BEGINS TO BUILD UP ACROSS CNTRL CANADA TOWARDS NEXT WEEKEND. TEMPERATURES...COLD SAT WITH READINGS STILL SOME 10 DEGREES BELOW NORMAL. BY SUNDAY READINGS WILL BE CLOSE TO NORMAL WITH THE HIGH PRESSURE SYSTEM PASSING EAST OF THE REGION. MUCH ABOVE NORMAL TEMPS ARE IN STORE FOR MONDAY...WHEN HIGHS WILL REACH THE MID/UPPER 60S IN MOST AREAS WITH SOME 70S ALSO POSSIBLE. TEMPERATURES WILL FALL BACK TO NEAR NORMAL TUESDAY...THEN A BIT BELOW NORMAL FOR THE REST OF THE WEEK. NORMAL TEMPS : PHL/ACY...MAX 50-52..MIN 35-37. RDG/ABE...MAX 48-50..MIN 30-32 GED...MAX 52-54..MIN 33-35. PRECIPITATION...DRY SAT THEN A CHC FOR SOME LIGHT MIXED PCPN ACROSS THE FAR NORTH FOR SAT NIGHT. MOSTLY DRY SUN...THEN CATEGORICAL POPS FOR RAIN SUN NIGHT...DECREASING TO CHC MON AND MON NIGHT. TUE/WED DRY ACROSS MOST AREAS...BUT SMALL CHC FOR RAIN ALONG THE COAST AS THE OP MODELS SHOWING A LOW MOVING JUST E OF THE AREA THEN. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR TODAY AND TONIGHT. W-NW WINDS AROUND 10-15 KT WILL GUST 20-25 KT SHORTLY AFTER SUNRISE. THE WINDS DO SUBSIDE IN THE AFTERNOON ALTHOUGH GUSTS TO 20 KT ARE STILL POSSIBLE. WINDS WILL DIMINISH TO UNDER 10 KT TOWARD SUNSET AND BECOME LIGHT/VARIABLE TONIGHT. OUTLOOK... SAT THRU SUN...VFR EXPECTED. INCREASING CLOUDS SUN. SUN NIGHT THRU MON NIGHT...LOWER CONDITIONS POSSIBLE IN RAIN/FOG. TUE...MOSTLY VFR. && .MARINE...
-- Changed Discussion --
GALE WARNING HAS BEEN ALLOWED TO EXPIRE AT 7 AM. A SMALL CRAFT ADVISORY WAS ALSO ISSUED FOR ALL OF THE WATERS TODAY. PREVIOUS DISCUSSION...THE FORECAST GALES HAVE FOR THE MOST PART FAILED TO MATERIALIZE AS STRONGER GUSTS HAVE NOT MIXED DOWN QUITE AS EFFECTIVELY AS EXPECTED. HOWEVER, THE LATEST DOWNSTREAM OBSERVATIONS AND HIRES MODEL GUIDANCE INDICATES A SURGE OF COLDER AIR ABOUT TO MOVE OVER THE WATERS. STILL EXPECT PREDOMINATELY SCA- LEVEL WINDS BUT THE POTENTIAL FOR A FEW GUSTS TO GALES WILL BE HIGHEST EARLY THIS MORNING. WILL THEREFORE BE CONSERVATIVE AND KEEP THE GLW UP FOR THE LOWER DE BAY AND ATLANTIC ZONES THRU 7 AM. AFTER GLW EXPIRES, A SCA WILL BE NEEDED FOR TODAY. SUB-SCA WINDS AND SEAS EXPECTED FOR TONIGHT. OUTLOOK... SAT/SAT NIGHT...LOW END SCA CONDITIONS EXPECTED. SUN...SUB-SCA CONDITIONS. SUN NIGHT THRU MON NIGHT...SCA CONDITIONS POSSIBLE. TUE...SCA CONDITIONS POSSIBLE EARLY ON THE OCEAN.
-- End Changed Discussion --
&& .FIRE WEATHER... A REINFORCING SHOT OF COLD AIR TODAY WILL BE ACCOMPANIED BY BREEZY NORTHWEST AND VERY DRY AIR. FREQUENT WEST-NORTHWEST GUSTS BETWEEN 20 AND 30 MPH ARE EXPECTED THIS MORNING BEFORE WINDS START TO WEAKEN THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. FORECAST MINIMUM RHS ARE GENERALLY IN THE LOWER 30S BUT MAY REACH THE 30 PERCENT RED FLAG CRITERIA IN A FEW SPOTS THIS AFTERNOON. HOWEVER, THESE MIN RHS THIS AFTERNOON MAY NOT COINCIDE WITH THE FREQUENT 20 MPH GUSTS, WHICH WOULD LOWER THE FIRE WEATHER THREAT. YESTERDAY`S FUEL MOISTURE OBSERVATIONS OBTAINED FROM THE NFDRS WAS BELOW 10 PERCENT IN THE DAY AREA. WE WILL LET THE DAY SHIFT COORDINATE WITH STATE OFFICIALS BEFORE ANY ENHANCED FIRE WEATHER STATEMENT IS ISSUED. && .PHI WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ431- 450>455. GALE WARNING UNTIL 7 AM EST THIS MORNING FOR ANZ431-450>455. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430.
-- End Changed Discussion --
&& $$ SYNOPSIS...O`HARA NEAR TERM...KLEIN SHORT TERM...KLEIN LONG TERM...O`HARA AVIATION...KLEIN/O`HARA MARINE...KLEIN/O`HARA FIRE WEATHER...KLEIN

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