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 291945 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 345 PM EDT MON SEP 29 2014 .SYNOPSIS...
-- Changed Discussion --
LOW PRESSURE OVER THE EASTERN GREAT LAKES TONIGHT WILL MOVE ACROSS PENNSYLVANIA TUESDAY WHILE A WEAK COLD FRONT SLIDES SOUTH ACROSS THE REGION. THAT LOW PRESSURE SYSTEM WILL DEVELOP OUT TO SEA WEDNESDAY WITH HIGH PRESSURE IN EASTERN CANADA RIDGING DOWN INTO THE MID ATLANTIC STATES THURSDAY. A STRONGER COLD FRONT WILL MOVE EAST ACROSS THE MID ATLANTIC STATES EARLY SATURDAY. WEAK HIGH PRESSURE FOLLOWS NEXT SUNDAY. A WARM FRONT APPROACHES THE REGION EARLY NEXT WEEK.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
MID AND HIGH LEVEL CLOUDS CONTINUE TO STREAM IN FROM THE SOUTHWEST IN ASSOCIATION WITH A INVERTED TROUGH EXTENDING FROM A LOW PRESSURE WELL TO OUR SOUTH. SOUNDINGS HAVE SHOWN ALL DAY A CONSIDERABLE AMOUNT OF DRY AIR IN THE MID-LEVELS. EVEN THOUGH THE RADAR SHOWS SOME PRECIPITATION MOST OF IT WILL BE VIRGA. HOWEVER THE RAP AND HRRR BRING IN SOME LIGHT PRECIPITATION (UNDER .05 INCHES) THIS EVENING ACROSS DELMARVA AND SOUTH NJ. DID INCLUDE THE THREAT FOR AN ISOLATED LIGHT RAIN SHOWER FOR THESE AREAS. KEPT MANY WEATHER ELEMENTS INCLUDING LOWS NEAR THE MET/MAV. THE MAV HAS BEEN TO DRY WITH SURFACE DEWPOINTS ALL DAY AND DID NOT INCORPORATE THIS SET FOR DEWPOINTS. WE MAY SEE SOME CLEARING AS WELL BY SUNRISE PERHAPS ALLOWING FOR A FEW HOUR WINDOW FOR THE FORMATION OF PATCHY FOG.
-- End Changed Discussion --
&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
-- Changed Discussion --
THE INVERTED TROUGH WILL BE WELL EAST OF OUR REGION. HOWEVER AN UPPER LEVEL LOW WILL BE QUICKLY ON ITS HEALS WITH AN ASSOCIATED COLD FRONT. THIS FRONT ALONG WITH MID-LEVEL SUPPORT MAY ALLOW FOR THE GENERATION OF SOME SCATTERED SHOWERS IN THE AFTERNOON FOCUSED NW OF PHL. FOR TEMPERATURES WENT SLIGHTLY WARMER THAN THE MAV/MET GUIDANCE SETS. ECMWF 925 MB TEMPERATURES WOULD YIELD TO SURFACE HIGHS IN THE LOW 80`S FOR PHL. HOWEVER WITH THE POTENTIAL FOR A FAIR AMOUNT OF CLOUDS KEPT HIGHS IN THE 70`S ACROSS THE REGION.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --
VERY FEW CHANGES IN THE EXTENDED PERIOD FORECAST FROM 12 HOURS AGO. SEVERAL CHANCES FOR RAIN THROUGH THIS TIME PERIOD BUT AMOUNTS LOOK LIKE THEY WILL BE ON THE RELATIVELY LIGHT SIDE. TEMPERATURES FOR THE TIME PERIOD WILL BE SLIGHTLY ABOVE NORMAL EARLY IN THE PERIOD, THEN TRENDING TO NEAR NORMAL LATE IN THE PERIOD. RAIN CHANCES TUESDAY NIGHT ARE ASSOCIATED WITH DEPARTING UPPER LEVEL TROUGH AND ASSOCIATED BACKDOOR COLD FRONT. HIGH PRESSURE BUILDS INTO THE REGION FOR LATE WEDNESDAY INTO FRIDAY. COLD FRONTAL BOUNDARY APPROACHING WITH NEXT UPPER LEVEL SYSTEM MOVES THROUGH LATE FRIDAY/EARLY SATURDAY BRINGING ANOTHER CHANCE OF RAIN. HIGHEST POPS THROUGH THE LONG TERM PERIOD ARE ASSOCIATED WITH THIS SYSTEM. HIGH PRESSURE BUILDS IN ONCE AGAIN FOR THE REMAINDER OF THE WEEKEND BEFORE A WARM FRONTAL BOUNDARY APPROACHES FROM THE SOUTHWEST LATE ON MONDAY, ONCE AGAIN BRINGING A CHANCE OF PRECIPITATION. USE WPC GUIDANCE PREDOMINATELY FOR DAYS 4 THOUGH 7. FOR TUE NIGHT INTO THU, USED A 50/50 BLEND OF PREVIOUS FORECAST AND ADJUSTED GFS MAV MOS
-- End Changed Discussion --
&& .AVIATION /19Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. HIGH LEVEL VFR CLOUDS AOA 15,000 FEET CONTINUE TO ADVECT IN FROM THE SOUTHEAST IN ASSOCIATION WITH LOW PRESSURE TO SOUTH. THIS LOW PRESSURE WILL PASS OFFSHORE KEEPING ANY PRECIPITATION TO A ISOLATED LIGHT SHOWER OR SPRINKLE, WITH ACY/MIV HAVING THE BEST CHANCE. DRY TAFS. OVERNIGHT, SOME SCATTERED LOWER VFR CLOUDS AROUND 4,000 FEET MAY DEVELOP. CURRENTLY IS IT MORE LIKELY THAT THE HIGHER LEVEL CLOUDS WILL PREVENT THE FORMATION OF LOWER CLOUDS OR FOG, EXCEPT AT RDG AND MIV WHICH TYPICALLY HAVE THE BEST CHANCE TO SEE FOG. ANY FOG SHOULD BURN OFF BY 14Z TUESDAY LEAVING SOME SCATTERED CLOUDS AOA 4,000 FEET, SO ANOTHER VFR DAY TUESDAY. THE NEXT FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST TUESDAY NIGHT. LOW CHANCE OF SHOWERS AT RDG AND ABE AFTER THE CURRENT TAF PERIOD WHICH CURRENTLY RUNS TILL 18Z TUESDAY. OUTLOOK... WEDNESDAY...MAINLY VFR CIGS WITH POSSIBLE MVFR CONDS IN SHOWERS KABE/KRDG/KTTN DURING THE MORNING. E/NE WINDS GUST 15 KNOTS. THURSDAY...POSSIBLE MVFR FOG EARLY OTHERWISE VFR SCT-BKN CLOUDS AOA 4000 FT. N-NW WIND GUST 15 KT. FRIDAY...VFR CIGS EXCEPT POSSIBLE MVFR CONDS IN ST/FOG EARLY FRIDAY MORNING AND THEN AGAIN FRIDAY NIGHT IN SHOWERS NEAR A COLD FRONT. E-SE WIND BECOMING S OR SW LATE AT NIGHT. SATURDAY...VFR CONDITIONS EXPECTED.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
SEAS THIS EVENING ARE AROUND TWO FEET ACROSS THE REGION. WINDS WILL BE LIGHT THROUGH TONIGHT AS WELL. TOMORROW WE WILL GRADUALLY SEE SEAS BUILD AND WINDS INCREASE OUT OF NORTHEAST. SEAS MAY REACH FOUR FEET TUESDAY AFTERNOON WITH SOME WIND GUSTS AROUND 20 KNOTS AS WELL. CONDITIONS BELOW SCA CRITERIA FOR THIS PERIOD. OUTLOOK... TUESDAY NIGHT THROUGH WEDNESDAY NIGHT: NE FLOW TUESDAY NIGHT THROUGH WEDNESDAY NIGHT SHOULD INCREASE TO SCA CRITERIA ALONG THE NNJ COAST TUESDAY NIGHT AND THEN POSSIBLY SOUTHWARD TO THE ENTIRE ATLC COAST LATER WEDNESDAY OR WEDNESDAY NIGHT. DELAWARE BAY MAY NOT SEE WIND GUSTS ABOVE 22 KT WITH ANY SCA HEADLINE THERE NOT LIKELY. HAVE HELD OFF ON ISSUING ANY FORMAL HEADLINES ON THIS FORECAST UPDATE AS CONDITIONS WILL JUST MEET LOWER END SCA CRITERIA AND CONFIDENCE IS NOT YET HIGH. THURSDAY...SMALL CHANCE OF SCA SEAS ON THE ATLANTIC WATERS FROM NE SWELLS GENERATED BY AN OFFSHORE LOW. FRIDAY...WIND BECOMING SOUTH BY NIGHT. SMALL CHANCE OF AN SCA AT NIGHT. SATURDAY...SCA CONDITIONS POSSIBLE EARLY WITH COLD FRONT PASSAGE, THEN IMPROVING CONDITIONS EXPECTED.
-- End Changed Discussion --
&& .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...SZATKOWSKI NEAR TERM...GAINES/HEAVENER SHORT TERM...GAINES/HEAVENER LONG TERM...SZATKOWSKI AVIATION...GAINES/SZATKOWSKI/HEAVENER MARINE...GAINES/SZATKOWSKI/HEAVENER

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