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 270246 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 946 PM EST WED NOV 26 2014 .SYNOPSIS...
-- Changed Discussion --
A COASTAL LOW WILL QUICKLY MOVE TO THE NORTHEAST OVERNIGHT. HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE EAST COAST FRIDAY INTO EARLY SATURDAY, BEFORE SQUEEZING TO THE SOUTH SATURDAY NIGHT. A COLD FRONT IS EXPECTED TO SAG DOWN ACROSS THE AREA SUNDAY NIGHT, BEFORE SLOWLY MOVING THROUGH THE AREA MONDAY INTO MONDAY NIGHT. HIGH PRESSURE WILL THEN RETURN TO THE NORTHEAST FOR TUESDAY, FOLLOWED BY ANOTHER POTENTIAL FRONTAL SYSTEM WEDNESDAY.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
MANY THANKS FOR THE REPORTS TODAY. IT WAS A BUSY TRAVEL DAY FOR MANY AND WE APPRECIATE THE SKYWARN NETS, THE SPECIAL COCORAHS REPORTS AS WELL AS ALL THE INFORMATION ON SOCIAL MEDIA. HAVE A MUCH QUIETER AND HAPPY THANKSGIVING TOMORROW! WITHOUT MUCH TO BLOCK IT, THE SURFACE LOW PRESSURE SYSTEM HAS QUICKLY REACHED THE WATERS SOUTH OF NANTUCKET. FRONTOGENETIC FORCING IS NOW NORTHEAST OF OUR CWA AND WHAT PRECIPITATION IS LEFT IS BECOMING VERY LIGHT. THE BANDED PRECIPITATION MOVING THROUGH NEW JERSEY HAS HAD THE OPPOSITE OF EXPECTED AFFECTS AS TEMPERATURES HAVE RISEN AND VSBYS IMPROVED AS IT MOVED THROUGH. AS IT PASSED OUR OFFICE IT WAS AS IF THE RAIN DROPS WERE TRYING TO FREEZE, BUT COULDNT. WITH VSBYS THREE MILES OR GREATER WHERE SNOW IS STILL FALLING, WE WILL LET ALL WINTER RELATED HEADLINES EXPIRE AT 10 PM. TEMPERATURES ARE EXPECTED TO FALL BELOW FREEZING BY MORNING IN MANY AREAS, SO ANY TRAVEL OVERNIGHT BE WARY ABOUT THE POTENTIAL FOR ICY SPOTS DEVELOPING ON UNTREATED ROADWAYS, PARKING LOTS AND SIDEWALKS. TO THE NORTHWEST THE SNOW AND SLUSH SHOULD FREEZE, TO THE SOUTHEAST NOT AS CONFIDENT ABOUT AOB FREEZING MINS, BUT THERE IS PLENTY OF STANDING WATER AROUND. PROPS TO THE ECMWF THAT HAD THIS GULF OF MEXICO SYSTEM AFFECTING US THE LONGEST INTO THE LONG TERM, IT ALSO HAD A WARMER SOLUTION THAT THE GFS AND WRF-NMMB TRENDED TOWARD. PTYPE A BLEND OF THE WRF AND GFS WORKED BEST AS WE CLOSED IN WITHIN OUR CWA. WE SAW SNOW AT SOME MIGHTY HIGH 1000-500MB THICKNESSES (AT LEAST 549DM), MOST OF THE ACCUMULATING SNOW OCCURRED AT THICKNESSES LESS THAN 546DM. AS MY PREDECESSOR INDICATED, THE SOUNDING AROUND PHL WAS NEARLY ISOTHERMAL FROM 700MB DOWNWARD, A RARE THERMAL EVENT INDEED.
-- End Changed Discussion --
&& .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... THE COASTAL LOW THAT IS IMPACTING THE AREA TODAY WILL TRACK NORTHEASTWARD INTO THE CANADIAN MARITIMES ON THURSDAY. THE TRAILING SURFACE TROUGH/COLD FRONT IS FORECAST TO MOVE OFF THE NJ COAST AND THROUGH THE DELMARVA. THE 12Z GFS AND ECMWF HINT AT A WEAK WAVE OF LOW PRESSURE DEVELOPING ON THE LEE SIDE OF THE BLUE RIDGE MOUNTAINS BY 12Z THURSDAY. THIS LOW WOULD THEN MOVE EAST-NORTHEAST OFF THE NC COAST DURING THE AFTERNOON. A FEW SHOWERS NORTH OF THIS LOW MAY BRUSH THE DELMARVA DURING THE DAY. BOUNDARY LAYER THERMAL PROFILES MARGINALLY SUPPORTIVE OF A SNOW PERHAPS MIXING IN WITH THE RAIN BUT NO ACCUMULATIONS EXPECTED WITH SURFACE TEMPERATURES NEAR 40F. OTHERWISE, CLOUDS WILL LINGER ACROSS THE AREA FOR MOST OF THE DAY WITH THE UPPER TROUGH PROGRESSING EASTWARD ACROSS THE MID ATLANTIC AND NORTHEAST STATES. USED A BLEND OF THE MAV/MET GUIDANCE FOR TEMPS, GIVING US HIGHS IN THE 30S FROM I-95 WEST AND LOWER 40S TO THE EAST. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... THURSDAY NIGHT IS EXPECTED TO BE DRY, WITH THE EXCEPTION OF A FEW LAKE EFFECT SNOW SHOWERS THAT MAY MAKE THEIR WAY ACROSS OUR NORTHERN AREAS. THEY WOULD BE QUITE ISOLATED, SO WE ONLY CARRY 20 POPS. ON FRIDAY, HIGH PRESSURE BEGINS TO BUILD ACROSS THE EAST COAST, BEFORE SQUEEZING TO OUR SOUTH AND EAST BY SATURDAY NIGHT. MODEL GUIDANCE IS INDICATING A COUPLE OF SHORT WAVE/VORTICITY IMPULSES SLIDING ACROSS THE AREA, ALONG WITH AN INCREASE IN MOISTURE ALOFT ACROSS THE NORTHERN AREAS. THERE IS SOME TIMING DIFFERENCES, BUT WE WILL KEEP A SLIGHT CHANCE OF SHOWERS ACROSS OUR NORTHWESTERN ZONES WHERE THEY HAVE A BETTER CHANCE OF SQUEEZING OUT SOME MOISTURE. ANYTHING THAT WOULD FALL IS EXPECTED TO BE LIGHT. ON SUNDAY, WE WILL BE IN BETWEEN THE HIGH TO OUR EAST AND AN APPROACHING COLD FRONT. ANOTHER WEAK SHORT WAVE/VORTICITY IMPULSE AND MOISTURE PLUME ALOFT SPREAD ACROSS THE NORTHERN HALF OF THE AREA SUNDAY, SO THERE REMAINS A SLIGHT CHANCE OF SHOWERS SUNDAY. A FRONTAL BOUNDARY IS EXPECTED TO APPROACH THE AREA SUNDAY NIGHT INTO MONDAY. THERE IS SOME DIFFERENCES WITH THIS BOUNDARY AS THE GFS IS FAST THAN THE ECMWF AND CANADIAN, AND DRIES THE PRECIP OUT SIMILAR TO THE CANADIAN, BUT UNLIKE THE ECMWF WHICH KEEPS SOME LIGHT PRECIP ACROSS THE AREA. WE WILL CONTINUE WITH CHANCE/SLIGHT CHANCE POPS, WITH THE HIGHEST ACROSS THE NORTHERN AND WESTERN AREAS WHERE THE PRECIP WOULD IMPACT FIRST BEFORE DRYING OUT. THE FRONT SHOULD PUSH TO OUR SOUTH AS HIGH PRESSURE BUILDS ACROSS THE NORTHEAST TUESDAY, BUT THERE COULD BE SOME LIGHT PRECIP THAT LINGERS ACROSS THE SOUTHERN AREAS IF THE FRONT STALLS CLOSER TO THE AREA. ANOTHER FRONTAL BOUNDARY IS EXPECTED TO AFFECT THE AREA AROUND NEXT WEDNESDAY. HOWEVER, THERE IS A QUESTION OF WHETHER THE FRONT SURGES THROUGH LIKE THE ECMWF, OR GETTING HUNG UP TO OUR NORTH LIKE THE GFS. WE WILL INTRODUCE A CHANCE/SLIGHT CHANCE OF POPS ACROSS THE AREA AS BOTH ARE SHOWING THE POTENTIAL FOR PRECIP. && .AVIATION /03Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...MVFR TRENDING TO VFR. LATER THIS EVENING WE SHOULD SEE THE PRECIPITATION BEGIN TO SLOW DOWN AS THE SURFACE LOW MOVES TO OUR NORTHEAST. THERE IS A CHANCE THAT WE COULD SEE ANOTHER CHANGE OVER TO A LIGHT RAIN/DRIZZLE AS WELL WHICH SHOULD HELP TO IMPROVE CONDITIONS A BIT...WINDS BACK TOWARDS THE NORTHWEST LATE. TOMORROW...VFR CONDITIONS EXPECTED. WINDS TURN MORE WESTERLY WITH MOSTLY DRY CONDITIONS EXPECTED. COULD BE SOME ISOLATED SHOWERS AT ILG/MIV/ACY DURING THE AFTERNOON HOURS. OUTLOOK... THURSDAY NIGHT...MOSTLY VFR. FRIDAY-MONDAY...MOSTLY VFR. WIND GUSTS 15-20 KNOTS EACH DAY; NW FRIDAY, SW SATURDAY & SUNDAY, AND NW ON MONDAY.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
GALE WARNINGS WILL BE CHANGED TO SMALL CRAFT ADVISORY ON THE OCEAN AND LOWER DELAWARE BAY. THE DELAWARE SMALL CRAFT ADVISORY WILL BE CARRIED FOR A COUPLE MORE HOURS. ON THE OCEAN, IT WILL BECOME THE SEAS THAT WILL BE DRIVER FOR SMALL CRAFT ADVISORY CONDITIONS TO PERSIST INTO THANKSGIVING DAY. OUTLOOK... THURSDAY NIGHT...WINDS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS, BUT SEAS MAY REMAIN ELEVATED INTO THURSDAY NIGHT. FRIDAY-FRIDAY NIGHT...SUB-SMALL CRAFT ADVISORY CONDITIONS EXPECTED AS HIGH PRESSURE BUILDS OVER THE AREA. SATURDAY-SUNDAY...NEAR SMALL CRAFT ADVISORY CONDITIONS POSSIBLE AS HIGH PRESSURE PUSHES TO OUR SOUTH AND COLD FRONT APPROACHES LATE ON SUNDAY NIGHT.
-- End Changed Discussion --
&& .CLIMATE... HERE ARE THE DAILY SNOWFALL RECORDS FOR OUR 4 SNOW CLIMATE SITES FOR NOVEMBER 26. ACY - TRACE IN 1977, 1957, 1955 PHL - 6.0 INCHES IN 1898 ILG - 0.1 INCHES IN 1950 ABE - 1.7 INCHES IN 1925. && .PHI WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR ANZ430-431.
-- End Changed Discussion --
&& $$ SYNOPSIS...ROBERTSON NEAR TERM...GIGI SHORT TERM...KLEIN LONG TERM...ROBERTSON AVIATION...HEAVENER/ROBERTSON MARINE...KLEIN/ROBERTSON CLIMATE...

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