Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 291639
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1239 PM EDT WED OCT 29 2014

.SYNOPSIS...
A COLD FRONT CROSSING NEW JERSEY AND DELAWARE AT NOON WILL MOVE OFF
THE COAST THIS EVENING. THE FRONT TRAILS INTO WEAK LOW PRESSURE OVER
SE VA. THE COLD FRONT AND LOW PRESSURE WILL CONTINUE MOVING OFFSHORE
TONIGHT. HIGH PRESSURE WILL BRIEFLY AFFECT THE AREA THURSDAY. AN
AREA OF LOW PRESSURE WILL MOVE OUT OF THE GREAT LAKES REGION AND
SOUTH OF THE AREA ON FRIDAY, BEFORE COMBINING WITH A DEVELOPING
AND STRENGTHENING COASTAL LOW OFFSHORE OF THE MID ATLANTIC COAST
SATURDAY. THIS LOW WILL MOVE WELL NORTHEAST OF THE AREA ON SUNDAY,
THEN HIGH PRESSURE IS EXPECTED TO BUILD BACK ACROSS THE EAST COAST
MONDAY, THEN OFFSHORE TUESDAY AHEAD OF AN APPROACHING FRONTAL
SYSTEM.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOUNT HOLLY IS ALSO SERVICE BACKING UP STERLING THROUGH 4 PM TODAY.
YOU`LL SEE STERLING FORECAST PRODUCTS ISSUED BY NWS MOUNT HOLLY.

1230 PM ESTF: LOWERED TEMPS AS A PROCESS FROM WEST TO EAST THIS
AFTN AFTER RAIN DEVELOPS. USED A 50 50 BLEND OF THE NEW 12Z/29
GFS/NAM MOS TEMPS. THERE STILL WILL BE ERRORS BUT TEMPS ARE
NOTABLY COOLER DURING MID AND LATE AFTN PER EXPECTED/MODELED RAIN.

EXPECTING A 2-4 HOUR WIDE BAND OF MEASURABLE SHOWERS. MAX AMT
.4 INCHES IN PWAT OF 1.1 INCHES...HEAVIEST NEAR I-95.

DID NOT INCLUDE ISOLATED THUNDER POTENTIAL VCNTY FENWICK ISLAND DE
LATE TODAY BUT ITS MODELED.

THE CURRENT HOURLY TEMPS OVER E PA AND NE MD IN RAIN COOLING THE
AIR TEMP (WET BULBING) MAY STILL BE 2 DEGREES TOO WARM IN EASTERN
PA DURING MID LATE AFTN (NEAR 52 DEGREES INSTEAD OF THE HOURLY
MID 50S TEMPS AS POSTED AT 1230 PM).

A COLD FRONT WILL CONTINUE TO PROGRESS EASTWARD FROM EASTERN NJ
AT 17Z. IT TRAILS INTO LOW PRES OVER SE VA WHICH IS A RESPONSE TO
PROCESSES ALOFT THAT WAS GENERATING THE BAND OF RAIN FROM WESTERN
VA INTO E PA NEWD.

RAINFALL AMOUNTS WILL BE LIGHT (GENERALLY UNDER ONE THIRD INCH).
ISOLATED SLIGHTLY HIGHER AMOUNTS POSSIBLE LATE THIS AFTERNOON AS A
WEAK DISTURBANCE TRAILING THE FRONT IS FORECAST TO TRACKS FROM VA
TO THE DELMARVA, LEADING TO AN ENHANCEMENT OF PRECIP OVER THE
SOMEWHERE OVER THE SOUTHEASTERN TWO THIRDS OF THE CWA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE COLD FRONT WILL CONTINUE TO MOVE OFF THE EAST COAST TONIGHT. THE
BACK EDGE OF THE LINGERING SHOWERS BEHIND THE BOUNDARY SHOULD BE
SHIFTING THRU THE I-95 CORRIDOR EARLY THIS EVENING AND OFF THE NJ/DE
COAST AROUND MIDNIGHT.

WEST-NORTHWEST WINDS BEHIND THE FRONT WILL ADVECT COLDER AND
EVENTUALLY DRIER AIR INTO THE REGION. SKIES WILL CLEAR NOT TOO LONG
AFTER PRECIP ENDS- DURING THE EVENING ACROSS EASTERN PA AND
NORTHWEST NJ AND OVERNIGHT FOR COASTAL AREAS. THE PRESSURE GRADIENT
WILL BE STRONG ENOUGH FOR A 5-10 MPH WIND TO CONTINUE OVERNIGHT
ESPECIALLY WITH CAA AIDING IN A MIXED NOCTURNAL BOUNDARY LAYER.
THEREFORE, WENT A COUPLE OF DEGREES ABOVE A MAV/MET BLEND FOR MIN
TEMPS.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE IS EXPECTED TO BRIEFLY AFFECT THE AREA THURSDAY
INTO THURSDAY NIGHT. DRY WEATHER AND NEAR NORMAL TEMPERATURES ARE
EXPECTED BEFORE A DECLINE IN THE WEATHER FOR THE UPCOMING WEEKEND.

ON FRIDAY, AN AREA OF LOW PRESSURE WILL BE MOVING OUT OF THE
GREAT LAKES REGION, AND IS EXPECTED TO MOVE TO THE SOUTH OF THE
AREA WHILE A COASTAL LOW DEVELOPS AND STRENGTHENS TO OUR SOUTH. WE
DO NOT EXPECT MUCH, IF ANY PRECIPITATION DURING THE DAY AS THE
PRECIPITATION TIED TO THE SYSTEM TO OUR WEST SHOULD REMAIN TO OUR
NORTH AND WEST UNDERNEATH THE MID/UPPER LOW/TROUGH. AS WE GO INTO
FRIDAY NIGHT, THE MID/UPPER LOW WILL SWING TO OUR SOUTH, WHILE THE
SURFACE LOW WILL BEGIN GETTING ABSORBED BY THE COASTAL LOW. THIS
WILL ALLOW SOME LIGHT PRECIPITATION TO FILL IN ACROSS THE AREA AS
THE MAJORITY OF THE MODEL GUIDANCE IS INDICATING. IT LOOKS LIKE
ANY PRECIPITATION THAT STARTS OUT FRIDAY NIGHT SHOULD BE MOSTLY A
COLD RAIN AS MODELS NOW KEEP 925/850 MB TEMPS ABOVE FREEZING,
ALTHOUGH IT IS STILL POSSIBLE FOR A MIXTURE ACROSS THE FAR
NORTHERN AREAS.

THE MID/UPPER TROUGH WILL SWING OFFSHORE OF THE NORTH CAROLINA
COAST SATURDAY, WHICH WILL ALLOW THE SURFACE LOW TO STRENGTHEN AND
WRAP UP MORE. THE GFS KEEPS THE PRECIP CLOSE TO THE SURFACE AND
MID-LEVEL LOW AND MOSTLY OFFSHORE, BUT THE ECMWF AND CANADIAN KEEP
PRECIP ACROSS THE ENTIRE AREA AND EXTEND IT PRETTY FAR TO OUR
NORTHWEST, SO WE WILL KEEP A CHANCE OF SHOWERS THROUGH THE DAY
SATURDAY. THE MODELS DO SHOW THE PRECIP MOVING TO OUR NORTHEAST
OVERNIGHT SATURDAY AS THE SURFACE AND MID/UPPER LOW PULL TO OUR
NORTHEAST, SO WE`LL HAVE DECREASING POPS OVERNIGHT. THE MODELS
KEEP THE SUB-FREEZING TEMPERATURES OUT OF THE AREA UNTIL
OVERNIGHT SATURDAY, SO THE BEST CHANCE FOR A MIX OR COMPLETE
CHANGE OVER TO SNOW WILL BE SATURDAY NIGHT INTO SUNDAY MORNING IF
THERE IS STILL ANY REMAINING PRECIPITATION, MAINLY ACROSS THE
NORTHERN THIRD OF THE AREA.

WINDS WILL INCREASE SATURDAY INTO SATURDAY NIGHT AS THE PRESSURE
GRADIENT TIGHTENS SIGNIFICANTLY BETWEEN THE COASTAL LOW AND HIGH
PRESSURE TO THE WEST. WINDS LOOK TO GUST BETWEEN 30-40 MPH, WITH
HIGHER GUSTS POSSIBLE CLOSER TO THE COAST.

SUNDAY IS EXPECTED TO BE DRY, BUT COLD AND BLUSTERY AS A STIFF
NORTHWEST FLOW IS EXPECTED AS THE LOW PRESSURE STRENGTHENS TO OUR
NORTHEAST AND HIGH PRESSURE BEGINS APPROACHING FROM THE WEST. WINDS
COULD CONTINUE TO GUST 30-40 MPH ACROSS THE AREA.

HIGH PRESSURE IS EXPECTED TO BUILD TO OUR SOUTH MONDAY AND NOSE ITS
WAY INTO OUR AREA. THIS WILL PROVIDE FAIR WEATHER WITH TEMPERATURES
RISING BACK CLOSER TO NORMAL.

ON TUESDAY, THE HIGH IS EXPECTED TO BUILD OFFSHORE OF THE SOUTHEAST
COAST, WHILE A WARM FRONT LIFTS NORTH OF THE AREA AHEAD OF THE NEXT
APPROACHING COLD FRONT. AS OF NOW, THE FORECAST FOR TUESDAY IS FOR
DRY WEATHER WITH WARMING TEMPERATURES, ALTHOUGH IF THE WARM FRONT
PASSES CLOSE ENOUGH, A FEW SHOWERS MAY BE POSSIBLE.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

FOR MOUNT HOLLY:

THIS AFTERNOON...PREDOMINATELY VFR CIGS THIS AFTERNOON AOA 3500
FT. A BRIEF PERIOD OF MVFR CIGS/VSBYS POSSIBLE WITH HEAVIER SHRA
BEHIND A COLD FRONT BUT CONFIDENCE FOR MVFR CONDS IS LOW AT THIS
TIME. SHOWER BAND LASTS 2-4 HOURS ONCE IT STARTS.

LATEST HIGH RES SHORT TERM GUIDANCE AND THE 12Z NAM ARE SUGGESTING
SHOWERS MAY NOT ARRIVE KACY AND KMIV TIL AROUND 21Z AND MAY LINGER
THROUGH 01Z THIS EVENING.

LIGHT SHIFTING WIND TURNING W TO NW AND BRIEFLY GUSTING 20 KT (1
HOUR LESS) BEHIND THE COLD FRONTAL PASSAGE.

TONIGHT...VFR CIGS CLEARING FROM WEST TO EAST WITH LEFTOVER RAIN
KACY/KMIV AND SE DELAWARE ENDING BY 03Z/30. LIGHT NORTHWEST WIND.

FOR STERLING: NWS MOUNT HOLLY IS BACKING UP THIS OFFICE AND THEIR
TAFS THROUGH 20Z TODAY.

THIS AFTERNOON...VFR CIGS. A 2-4 HOUR WIDE BAND OF SHOWERS
CROSSES THE AREA. BRIEF MVFR CONDS POSSIBLE IN A HEAVIER SHOWER.

TONIGHT...CLEARING WITH A LIGHT NW WIND.


OUTLOOK...

THURSDAY-FRIDAY...MOSTLY VFR.

FRIDAY NIGHT-SATURDAY NIGHT...LOWER END VFR OR UPPER END MVFR WITH
CIGS 2,500-3,500 EXPECTED. LOWER VSBYS POSSIBLE WITH RAIN SHOWERS.
SNOW SHOWERS POSSIBLE ACROSS NORTHEAST PENNSYLVANIA AND NORTHWEST
NEW JERSEY. GUSTY NORTH-NORTHWEST WINDS SATURDAY INTO SATURDAY NIGHT
25-30 KNOTS, POSSIBLY HIGHER NEAR THE COAST.

SUNDAY...VFR. GUSTY NORTHWEST WINDS 25-30 KNOTS.

&&

.MARINE...
44065 HAS RETURNED TO SVC. 44009 WINDS OTS AND WE DONT KNOW A
SERVICE DATE YET.

NO HEADLINES THROUGH TONIGHT.

SW WIND 10-15 KT SHIFTING WNW BY MID AFTERNOON WITH SCT GUSTS TO 20
KT. NW WIND TONIGHT AT 10 TO 15 KT.

OUTLOOK...
THURSDAY-FRIDAY NIGHT...SUB-SMALL CRAFT ADVISORY CONDITIONS
EXPECTED, ALTHOUGH WINDS A SEAS WILL BE INCREASING LATE FRIDAY NIGHT.

SATURDAY-SATURDAY NIGHT...INCREASING WINDS SATURDAY AND SATURDAY
NIGHT AS A COASTAL LOW STRENGTHENS. GALE FORCE WINDS LOOKING MORE
LIKELY.

SUNDAY...GALE FORCE WINDS POSSIBLE EARLY, BEFORE DIMINISHING TO
SMALL CRAFT ADVISORY LEVELS LATE IN THE DAY.

&&

.EQUIPMENT...
SERVICE BACKUP FOR STERLING - LWX TODAY. HAVE LISTED THIS UNDER
EQUIPMENT...JUST IN CASE THIS SERVICE BACKUP MESSAGE IS MISSED IN
THE NEAR TERM AND AVIATION SECTION.

44009 BUOY HAS RETURNED TO SVC. 44009 WIND OTS AND NO SERVICE DATE
YET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...ROBERTSON
NEAR TERM...DRAG 1239
SHORT TERM...KLEIN
LONG TERM...ROBERTSON
AVIATION...DRAG/ROBERTSON 1239
MARINE...DRAG/ROBERTSON 1239
EQUIPMENT...






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