Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 272039
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
339 PM EST THU NOV 27 2014

.SYNOPSIS...
HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE EAST COAST FRIDAY INTO
FRIDAY NIGHT, BEFORE MOVING TO THE SOUTH AND EAST SATURDAY INTO
SATURDAY NIGHT. A WARM FRONT MAY LIFT NORTH OF THE AREA SATURDAY
NIGHT INTO SUNDAY. 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 BRIEFLY RETURN TO THE
NORTHEAST FOR TUESDAY, FOLLOWED BY ANOTHER FRONTAL SYSTEM AROUND
WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE COASTAL LOW THAT BROUGHT WINTRY WEATHER TO THE NORTHWESTERN
HALF OF THE FORECAST AREA YESTERDAY IS NOW OVER THE CANADIAN
MARITIMES. MEANWHILE, THE UPPER TROUGH ASSOCIATED WITH THIS SYSTEM
IS POSITIONED BACK OVER THE EASTERN CONUS.

THE SNOW SHOWER ACTIVITY THAT BROUGHT LIGHT SNOWFALL ACCUMULATIONS
TO THE HIGHER ELEVATIONS OF THE NORTHEAST PA AND NW NJ THIS MORNING
HAS EXITED THE AREA AND IS NOW OVER SOUTHERN NEW ENGLAND. SUBSIDENCE
BEHIND THE EXITING SHORTWAVE TROUGH IS MOVING IN, YIELDING SOME
BREAKS IN THE CLOUDS. TEMPS HAVE BEEN ABLE TO RISE INTO THE 40S
ACROSS THE NORTHERN DELMARVA AND SOUTHERN NJ WHERE CLEARING HAS BEEN
MOST PROMINENT. ELSEWHERE, TEMPS ARE STUCK IN THE 30S THIS
AFTERNOON. A SECOND SHORTWAVE DISTURBANCE IS CURRENTLY CROSSING THE
LOWER DELMARVA THIS AFTERNOON. AN ISOLATED SHOWER OR SPRINKLE IS
POSSIBLE OVER SOUTHERN DE AND ADJACENT PARTS OF EASTERN MD THROUGH
SUNSET.

STRATOCU SHOULD ERODE THIS EVENING WITH THE LOSS OF DAYTIME MIXING
AND AS DRIER AIR NEAR 925 MB ADVECTS INTO THE AREA. MID AND HI
CLOUDS WILL THEN SPREAD IN FROM THE WEST LATE TONIGHT AS THE NEXT
UPPER SHORTWAVE TROUGH APPROACHES FROM THE GREAT LAKES. MIN TEMPS
TONIGHT RANGE FROM NEAR 20F IN THE POCONOS TO NEAR 30F IN THE
DELMARVA, SOUTHERN NJ COAST AND IN CENTER CITY PHILLY.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS IS EXPECTED TO PROGRESS EAST OF THE MID-
ATLANTIC REGION BY 12Z FRIDAY. SUBSIDENCE IN ITS WAKE WILL BE
ACCOMPANIED BY CLEARING SKIES AND DRY WEATHER FOR BLACK FRIDAY. A
CAA REGIME UNDER NORTHWEST FLOW BEHIND THE TROUGH WILL PERSIST AS
WELL. SO DESPITE SUNSHINE TOMORROW VS CLOUDY SKIES TODAY, MAX TEMPS
FRIDAY WILL BE SEVERAL DEGREES COOLER THAN TODAY. HIGHS RANGE FROM
THE UPPER 20S IN THE POCONOS TO NEAR 40F ALONG THE COAST.

EXPECT WINDS TO BE BREEZY (GUSTS 20-25 MPH) IN THE MORNING AS HIGH
PRESSURE BUILDS IN FROM THE TENNESSEE VALLEY. THE WINDS RELAX A BIT
LATE IN THE DAY WHEN THE HIGH SHIFTS OVERHEAD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE OVER THE AREA FRIDAY NIGHT WILL BEGIN TO MOVE TO OUR
SOUTH AND EAST BY SATURDAY AND SATURDAY NIGHT. SEVERAL WEAK SHORT
WAVE/VORTICITY IMPULSES ARE FORECAST TO SLIDE ACROSS THE AREA FRIDAY
NIGHT, SATURDAY, AND SATURDAY NIGHT, ALONG WITH AN INCREASE IN
MOISTURE ALOFT ACROSS THE NORTHERN AREAS. THERE IS SOME TIMING
DIFFERENCES, BUT THERE IS SOME POTENTIAL FOR SOME LIGHT
PRECIPITATION TO DEVELOP DURING THIS TIME PERIOD. WE WILL KEEP A
SLIGHT CHANCE OF SHOWERS ACROSS OUR NORTHERN 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 SAG TOWARD THE AREA SUNDAY NIGHT,
THEN SLOWLY MOVE THROUGH THE AREA INTO MONDAY INTO MONDAY NIGHT.
THERE CONTINUES TO BE SOME SLIGHT DIFFERENCES WITH THIS BOUNDARY
WITH THE GFS THE FASTEST, THE CANADIAN THE SLOWEST, AND THE ECMWF IN
BETWEEN. ALSO THERE AREA DIFFERENCES WITH QPF AMOUNTS, SO WE WILL
KEEP CHANCE/SLIGHT CHANCE POPS ACROSS THE AREA DURING THIS PERIOD.

THE FRONT SHOULD PUSH TO OUR SOUTH AS HIGH PRESSURE BRIEFLY BUILDS
ACROSS THE NORTHEAST TUESDAY. THE GFS AND ECMWF INDICATE DRIER AIR
BUILDING ACROSS THE AREA DURING THE DAY, SO WE MAKE THE FORECAST DRY
FOR TUESDAY DAY.

ANOTHER FRONTAL SYSTEM IS EXPECTED TO AFFECT THE AREA AROUND NEXT
WEDNESDAY. A WARM FRONT MAY LIFT ACROSS THE AREA TUESDAY NIGHT AS
THE HIGH RETREATS NORTHEASTWARD, BEFORE A COLD FRONT MOVES ACROSS
THE AREA ON WEDNESDAY. PRECIPITATION CHANCES INCREASE TUESDAY INT
WEDNESDAY, THEN LOWER BEHIND THE FRONT WEDNESDAY NIGHT INTO THURSDAY
AS HIGH PRESSURE BUILDS BACK ACROSS THE NORTHEAST AGAIN.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

MAINLY OVC STRATOCU BETWEEN 2-3 KFT RESULTED IN MVFR CONDITIONS
EARLY THIS AFTN. SOME CLEARING HAS SINCE DEVELOPED OVER PORTIONS OF
THE REGION, RESULTING IN THE MAJORITY OF THE TERMINALS VARYING
BETWEEN MVFR AND VFR SINCE ABOUT 19Z. EXPECT THIS TO CONTINUE THRU
21-00Z BEFORE DRIER AIR WORKS INTO THE AREA AND FURTHER CLEARING
OCCURS. MID TO HI CLOUDS ARE FORECAST TO SPREAD INTO THE REGION LATE
TONIGHT BUT VFR WILL PREVAIL. W-NW WINDS AROUND 5-10 KT.

VFR ON FRIDAY. NW WINDS WILL GUST TO 20 KT FROM MID MORNING THRU MID
AFTN. WINDS RELAX LATE IN THE DAY.

OUTLOOK...
FRIDAY NIGHT-MONDAY...MOSTLY VFR. WIND GUSTS 15-20 KNOTS EACH DAY;
SOUTHWEST SATURDAY & SUNDAY, AND NORTHWEST ON MONDAY.

MONDAY NIGHT...CHANCE OF RAIN OR SNOW SHOWERS. GENERALLY VFR UNLESS
PRECIPITATION OCCURS. GUSTY NORTHWEST WINDS AROUND 20 KNOTS POSSIBLE.

TUESDAY...MOSTLY VFR.

&&

.MARINE...
THE SCA FOR HAZARDOUS SEAS THAT WAS IN EFFECT FOR THIS AFTN HAS BEEN
CANCELLED. HOWEVER, A NEW SCA WAS ISSUED FOR TONIGHT AND FRIDAY FOR
THE DE BAY AND MOST OF THE OCEAN ZONES TO COVER THE EXPECTED
NORTHWEST PRESSURE SURGE. MIXING WILL BE EFFECTIVE WITH EVEN COLDER
AIR MOVING ABOVE THE RELATIVELY WARMER WATERS. THE ONE EXCEPTION TO
THE SCA IS THE COASTAL WATERS FROM SANDY HOOK TO MANASQUAN INLET.
THE SCA FOR THIS NORTHERN MOST ZONE IS ONLY IN EFFECT FRIDAY SINCE
THE PRESSURE GRADIENT WILL BE A BIT WEAKER TONIGHT AND THE GUST
POTENTIAL SHOULD BE CAPPED AROUND 20 KT.

OUTLOOK... FRIDAY NIGHT-SATURDAY...SUB-SMALL CRAFT ADVISORY
CONDITIONS EXPECTED AS HIGH PRESSURE BUILDS OVER THE WATERS.

SATURDAY-SUNDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS POSSIBLE AS
HIGH PRESSURE PUSHES TO OUR SOUTH AND COLD FRONT APPROACHES LATE ON
SUNDAY NIGHT.

MONDAY-MONDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS REMAIN
POSSIBLE BEHIND THE COLD FRONT THAT MOVES ACROSS THE AREA.

TUESDAY...SUB-SMALL CRAFT ADVISORY CONDITIONS EXPECTED AS HIGH
PRESSURE AFFECTS THE WATERS.


&&

.EQUIPMENT...
KDIX WSR-88D RADAR IS INOPERATIVE. TECHNICIANS HAVE BEEN NOTIFIED
AND WILL TROUBLESHOOT THE ISSUE. TPHL TDWR SHOULD PROVIDE
SUFFICIENT BACKUP RADAR COVERAGE.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ430-431-
     451>455.
     SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST FRIDAY FOR ANZ450.

&&

$$
SYNOPSIS...ROBERTSON
NEAR TERM...KLEIN
SHORT TERM...KLEIN
LONG TERM...ROBERTSON
AVIATION...KLEIN/ROBERTSON
MARINE...KLEIN/ROBERTSON
EQUIPMENT...KLEIN




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