Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 310134
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
934 PM EDT THU OCT 30 2014

.SYNOPSIS...
HIGH PRESSURE OVER OUR REGION WILL SHIFT TO NORTHERN NEW ENGLAND
BY MORNING. LOW PRESSURE OVER OHIO FRIDAY AFTERNOON WILL JOIN
FORCES WITH LOW PRESSURE EAST OF THE CAROLINAS TO FORM A STRONG
STORM SOUTHEAST OF CAPE COD LATE SATURDAY. THAT STORM MOVES TO THE
MARITIMES SUNDAY. STRONG HIGH PRESSURE SETTLES INTO THE CAROLINAS
EARLY NEXT WEEK THEN SLIPS EASTWARD INTO THE CENTRAL ATLANTIC NEXT
WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
WEAK HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR REGION
OVERNIGHT.

THE DAYTIME STRATOCUMULUS CONTINUED TO DISSIPATE THIS EVENING. WE
ARE ANTICIPATING FEW TO SCATTERED CLOUDS DURING THE NIGHT WITH A
LIGHT WIND, MAINLY 5 MPH OR LESS FAVORING THE NORTH.

TEMPERATURES ARE ANTICIPATED TO FALL INTO THE RANGE FROM THE
MIDDLE 30S TO THE LOWER 40S TOWARD DAYBREAK. THE LOW LEVEL AIR IN
OUR REGION IS DRIER THAN IT WAS LAST NIGHT, SO NO FOG IS
EXPECTED.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
TWO AREAS OF LOW PRESSURE WILL BEGIN TO IMPACT OUR WEATHER LATE
IN THIS PERIOD. THE FIRST ONE WILL BE OVER THE GREAT LAKES AND
OHIO VALLEY FRIDAY WITH THE SECOND DEVELOPING OFF THE CAROLINA
COASTLINE. CLOUDS FROM THE LOW PRESSURE SYSTEM TO OUR WEST SHOULD
BEGIN TO MOVE IN LATE IN THE DAY. WINDS WILL SHIFT TO THE
NORTHEAST IN RESPONSE TO THE LOW PRESSURE OFF THE CAROLINA COAST.
THIS WILL LIKELY ALLOW ADDITIONAL CLOUDS TO ADVECT IN FROM THE
OCEAN DURING THE AFTERNOON. SOME PATCHY DRIZZLE CAN NOT BE RULED
OUT ALONG THE COAST. MODELED 925 MB TEMPERATURES INDICATE THE
POTENTIAL FOR HIGHS IN THE UPPER 50`S ON FRIDAY FOR PHL. HOWEVER
WITH CLOUDS MOVING IN IT WILL BE HARD TO REACH THESE AND KEPT
HIGHS IN THE MID 50`S WITH SOME UPPER 40`S NW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
500 MB: A HIGH AMPLITUDE TROUGH IN THE EASTERN UNITED STATES THIS
WEEKEND MOVES TO THE MARITIMES EARLY NEXT WEEK WHILE A WARMING
RIDGE FOLLOWS EARLY NEXT WEEK. ANOTHER TROUGH EVOLVES IN THE
EASTERN UNITED STATES LATER NEXT WEEK.

TEMPERATURES: BY THE TIME THE LONG TERM FORECAST PERIOD BEGINS
WE`VE CLOSED OUT THE MONTH OF OCTOBER THAT AVERAGED MORE THAN 2
DEGREES ABOVE NORMAL. NOVEMBER STARTS OUT NEAR NORMAL SATURDAY...
5 DEGREES COLDER THAN NORMAL SUNDAY WITH WIND... STILL NEARLY 5
DEGREES BELOW NORMAL MONDAY BUT WITH LESS WIND AND THEN NEAR
NORMAL TUESDAY. TEMPERATURES SHOULD AVERAGE SEVERAL DEGREES ABOVE
NEXT WEDNESDAY AND THURSDAY....MAYBE AS MUCH AS 10 DEGREES ABOVE
NORMAL EITHER DAY.

HAZARDS: GALE SATURDAY POSSIBLY LINGERING INTO SUNDAY. POSSIBLE
MINOR TIDAL INUNDATION FLOODING NEAR THE TIME OF HIGH TIDE
SATURDAY AFTERNOON AND NIGHT BUT THIS IS NOT LIKELY. A SMALL
CHANCE OF SPOTTY WIND ADVISORY CONDITIONS SUNDAY.

FORECAST BASIS: UNLESS OTHERWISE NOTED THE LONG TERM PERIOD OF
THIS FORECAST IS GENERALLY BASED ON A 50 50 BLEND OF THE 12Z/30
NAM/GFS MOS FOR THE PERIOD FRIDAY NIGHT-SATURDAY NIGHT AND THEN
THAT VALUE BLENDED 50 PCT WITH THE 00Z/30 ECMWF 2M TEMPS. 12Z/30
GFS MOS COMPRISES SUNDAY AND SUNDAY NIGHT...THEN THEREAFTER
(MONDAY ONWARD) THE 1523Z/30 WPC GRIDDED GUIDANCE WHICH AT TIMES
IS BLENDED 50 50 WITH THE 12Z/30 MEXMOS. ALL THIS WAS EVENTUALLY
CHECKED AGAINST THE 12Z/30 ECMWF THROUGH TUESDAY ONLY, WHEN WE
MODIFIED THE NCEP-WPC GUIDANCE HIGHER BY SEVERAL DEGREES BOTH
MONDAY AND TUESDAY!

THE REMAINDER..WEDNESDAY AND BEYOND..OF THE 12Z/30 OPERATIONAL
ECMWF DID NOT ARRIVE IN A TIMELY FASHION AND WAS NOT USED FOR THIS
FORECAST.

PRECIPITATION PROBABILITY GUIDANCE IS CHECKED AGAINST THE 09Z/30
SREF 3HRLY POPS FOR .01 THROUGH 00Z MONDAY AND THEREAFTER THE
12Z/30 GEFS 6HR POPS FOR 0.05.

THE DAILIES BELOW...

FRIDAY NIGHT...PERIODS OF RAIN DEVELOPING WESTWARD THROUGH
NJ...POSSIBLY DURING THE EVENING TRICK OR TREAT TIME. CONFIDENCE
ON FORECAST DETAILS IS AVERAGE.

SATURDAY...COOLER THAN NORMAL AND BRISK WITH NORTHERLY GUSTS
20-30 MPH. RAIN PROBABLE AT TIMES SE PA THROUGH SOUTHERN-CENTRAL
NJ AND PROBABLY SOUTH ONTO THE DELMARVA. 15Z SREF IS DRIER THAN
I`D LIKE TO SEE FOR SATURDAY. SO THE COMBINATION OF THE LATE
ARRIVING ECMWF AND SPREAD IN SOLUTIONS LOWERS MY CONFIDENCE ON
SATURDAYS FORECAST TO ONLY AVERAGE.

SUNDAY...WINDY AND MAYBE 5 DEGREES COLDER THAN NORMAL WITH
NORTHWEST WINDS GUSTS 30-40 MPH. ISOLATED WIND ADVISORY CRITERIA
POSSIBLE. THE GFS IS MORE ROBUST THAN THE 12Z ECMWF AND SO MY
CONFIDENCE ON MAX WIND GUST IS BELOW AVERAGE. DIURNAL SC WITH
PLENTIFUL MORNING SUNSHINE HIDING BEHIND INCREASING MIDDAY SC.
THERE IS A SMALL CHANCE OF BUT AS YET UNMENTIONED...FOR AN
AFTERNOON SPRINKLE WITH A SECONDARY TROUGH ALOFT PASSAGE. IF THE
SPRINKLES MATERIALIZE...IT WOULD BE A SNOW SHOWER IN THE POCONOS.

SUNDAY NIGHT...THE FROST FREEZE PORTION FOR OUR FORECAST AREA
ENDS NOVEMBER 1 SO DESPITE THE FORECAST OF FROST OR FREEZING
TEMPERATURES UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS...A HEADLINE
WILL NOT BE ISSUED. THERE IS A CHANCE OF MID LEVEL CLOUD COVER
ARRIVING AROUND DAWN.

MONDAY...DIMINISHED WIND AND MILDER. MID LVL CLOUD COVER. WEST
WIND GUST 15 MPH. THE WPC GUIDANCE WAS RAISED BY 4 DEGREES DUE TO
THE MUCH MILDER 12Z/30 ECMWF 2M TEMPS.

TUESDAY...LOW CONFIDENCE ON HOW MUCH CLOUD COVER. THIS SHOULD BE
A NICE DAY. ABOVE NORMAL TEMPS.

WEDNESDAY...PROBABLY STILL NICE. MAYBE A SHOWER DEVELOPS LATE.
ABOVE NORMAL TEMPS.

THURSDAY...MAYBE A PERIOD OF SHOWERS OTHERWISE...THE NEXT TROUGH
AND A COOL FRONT MAY BE MOVING INTO THE EASTERN USA. ABOVE NORMAL
TEMPERATURES.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.

FEW TO SCATTERED CLOUDS ARE ANTICIPATED DURING THE NIGHT AND INTO
FRIDAY MORNING. AN INCREASE IN STRATOCUMULUS IS EXPECTED DURING
THE AFTERNOON. CEILINGS ARE FORECAST TO BE AROUND 4000 TO 5000
FEET AT THAT TIME.

A LIGHT WIND AT 5 KNOTS OR LESS SHOULD FAVOR THE NORTH OVERNIGHT.
A NORTH TO NORTHEAST WIND AROUND 4 TO 8 KNOTS IS EXPECTED FOR
FRIDAY.

OUTLOOK...
FRIDAY NIGHT...VFR CIGS MAY LOWER TO MVFR CIGS LATE. -SHRA SHOULD
BE DEVELOPING OVER NJ POSSIBLY RESULTING IN MVFR VSBY AS WELL.

SATURDAY...MVFR CIGS WITH POSSIBLE IFR CONDS IN SHOWERS ACROSS SE
PA...THE DELMARVA...S AND CENTRAL NJ. NORTHERLY WINDS GUST 20-30
KT.

SATURDAY NIGHT...CONDITIONS WILL SLOWLY IMPROVE FROM WEST TO EAST
THROUGH THE NIGHT. GUSTY NNW WINDS SHOULD CONTINUE ESPECIALLY AT
KACY.

SUNDAY...MOSTLY VFR CONDITIONS. NW WIND GUSTS 23-33KT DIMINISHING
AT NIGHT. CIGS NEAR 3500 FT IN THE EARLY AFTERNOON MAY YIELD AN
ISOLATED SPRINKLE (EXCEPT FLURRY POCONOS?).

MONDAY...VFR WITH BKN CIGS AOA 10000 FT. W-NW WIND GUSTING 15 KT.

TUESDAY...VFR.

&&

.MARINE...
SEAS AND WINDS SHOULD REMAIN BELOW SCA CRITERIA THROUGH FRIDAY
AFTERNOON. HOWEVER SOME WIND GUSTS CLOSE TO 20 KNOTS ARE POSSIBLE
BY FRIDAY EVENING OFF THE DELAWARE COAST.

OUTLOOK...
HEADLINES HAVE BEEN ISSUED. TIMING OF THE ONSET OF GALE FORCE
GUSTS IS STILL UNCERTAIN AND IF THIS GALE IS DELAYED TIL SATURDAY
EVENING...I WANTED AN SCA TO PRECEDE.

THE 12Z/30 GFS WW3 MODELED SEAS WERE INCREASED BY 2-3 FT SATURDAY
THROUGH MIDDAY SUNDAY.

FRIDAY NIGHT THROUGH SUNDAY...WINDS WILL BUILD INTO SCA CRITERIA,
AND THEN GALES, WITH PEAK GUSTS NEAR 40KT POSSIBLE DURING THE DAY
ON SATURDAY. GALE CONDITIONS COULD CONTINUE THROUGH MUCH OF THE
DAY SUNDAY.

SUNDAY NIGHT INTO MONDAY...WINDS SHOULD SUBSIDE BELOW SCA
CRITERIA THROUGH THIS PERIOD THOUGH SCA SEAS MAY LINGER INTO EARLY
MONDAY?

TUESDAY...NO HEADLINE ANTICIPATED.

&&

.TIDES/COASTAL FLOODING...
AN ONSHORE COMPONENT OF THE BREEZY TO WINDY CONDITIONS ON
SATURDAY WILL LEAD TO ELEVATED WATER LEVELS THIS WEEKEND. MINOR
TIDAL FLOODING MAY OCCUR WITH THE HIGH TIDE CYCLES SATURDAY AND
SATURDAY NIGHT. AT THIS TIME WE THINK IT UNLIKELY BUT WE STILL ARE
MONITORING.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WATCH FROM SATURDAY MORNING THROUGH LATE SATURDAY NIGHT
     FOR ANZ431-450>455.
     SMALL CRAFT ADVISORY FROM MIDNIGHT FRIDAY NIGHT TO 6 AM EDT
     SATURDAY FOR ANZ450>455.

&&

$$

SYNOPSIS...DRAG
NEAR TERM...IOVINO
SHORT TERM...GAINES
LONG TERM...DRAG
AVIATION...DRAG/IOVINO
MARINE...DRAG/GAINES
TIDES/COASTAL FLOODING...DRAG






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