Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 230432
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1232 AM EDT WED JUL 23 2014

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE EASTWARD TONIGHT ALLOWING FOR A
BETTER RETURN FLOW TOMORROW AHEAD OF A POTENT COLD FRONT. THE FRONT
SHOULD MOVE THROUGH LATER ON WEDNESDAY INTO THURSDAY MORNING. HIGH
PRESSURE WILL FILL IN BEHIND THE DEPARTING FRONT THROUGH THE FIRST
HALF OF THE WEEKEND BEFORE A COMPLEX SYSTEM APPROACHES SUNDAY
SPILLING INTO THE NEW WORK WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
THE 1230 AM FURTHER ESTF UPDATE HAS CONSIDERABLY REDUCED THE FOG
IN THE FCST AND DELAYED IT. TOO MUCH TT/TD SPREAD AT 04Z.

FAIR EARLY THIS MORNING...PATCHY FOG TOWARD 10Z...MAINLY NW NJ.
USED THE UPS CROSSOVER TOOL WHICH IS MORE CONSERVATIVE THAN THE
FOGGER TOOL.

TODAY...LITTLE CHANGE IN PHILOSOPHY. MODEL GUIDANCE STATES WIDESPREAD
LOWER 90S (NEAR 18C 850 MB AND 925MB HOTTEST TEMPS ARE JUST WEST
AND NORTHWEST OF OUR FCST AREA). POCONOS AND IMMEDIATE ATLC SHORE
A BIT COOLER.

HEAT INDEX UPPER 90S. NO HEAT ADVY IN THIS CONTINUING SUMMER BEREFT
OF HEAT.

HAVE WITHDRAWN MORNING THUNDER IN E PA AND NW NJ.

TSTMS PROBABLY RESTRICTED TO NW NJ AND NE PA AFTER 21Z...POSSIBLY
A SECOND CLUSTER CROSSING CHES BAY? TT 48+ SWI -2 KI INCREASING TO
38C VCNTY POCS AND E VA. APPEARS TO BE A SEE TEXT CASE...UNLIKELY
SVR THROUGH 00Z DUE TO LACK OF BULK SHEAR...500MB WINDS UNDER 30
KT AND MLCAPE CLOSER TO 1600J.

NOTE THAT THERE SHOULD BE CU FIELDS FORMING THIS MORNING OVER NNJ
IN A LEADING EDGE AREA OF KI 33C BUT WITH LITTLE OR NO PRIMARY
FORCING AM NOT EXPECTING TO YIELD ANY LATE MORNING TSTMS IN NNJ AS
THIS LEAD AREA OF INSTABILITY SHOVES ENE TO LI BY 18Z.

PROBABLY A 50 50 BLEND OF THE 00Z/23 NAM/GFS GUIDANCE IN THE 330
AM ISSUANCE.

&&

.SHORT TERM /TONIGHT/...
SLOW SEWD PROGRESS OF THE COLD FRONT INTO THE UNSTABLE AIRMASS
SHOULD YIELD BANDS OF TSTMS INTO THE EARLY NIGHT BUT NOT NECESSARILY
WIDESPREAD. ONE OR 2 TSTMS COULD BE SVR BUT BULK SHEAR IS MARGINAL
AT WORST FOR SVR AND ONLY THE TT AND SOME CAPE ALLOW FOR MODEST
ISOLATED SVR POTENTIAL.

PWAT 1.8 INCHES OFFERS A CHANCE OF NARROW PATHS OF 2 INCH RAINS
BENEATH THE BIGGEST STORMS.

50 50 BLEND OF THE 00Z/23 GFS/NAM GUIDANCE IN THE 330 AM ISSUANCE.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE BASE OF THE TROUGH BEGINS TO FLATTEN OUT BY FRIDAY, THOUGH NOT
ENTIRELY BECOMING ZONAL. THIS YIELDS SLIGHTLY BELOW NORMAL
TEMPERATURES AND DECREASED CHANCES FOR CONVECTION GIVEN A DRIER
AIRMASS IN PLACE. STILL A BIT UNCERTAIN ABOUT THE SATURDAY EVENING
TIMEFRAME AS SOME OF THE OPERATIONAL GUIDANCE SWINGS A PIECE ENERGY
THROUGH THE BASE OF THE TROUGH WHICH COULD TOUCH OFF A COUPLE
STRAY/ISOLATED SHOWERS...BETTER EAST THAN WEST WITH BETTER MOISTURE
POOLING AND SEABREEZE INTERACTION.

RIDGING BUILDS INTO THE WEST SENDING STRONGER SHORTWAVES OF ENERGY
INTO THE TROUGH OVERHEAD ALLOWING FOR ANOTHER BOUT OF DEEPER
TROUGHING. EXPECT UNSETTLED WEATHER THROUGH THE REMAINDER OF THE
LONGTERM AS A SERIES OF EMBEDDED WAVES PUSHES THROUGH ALOFT TOUCHING
OFF SHOWERS AND THUNDERSTORMS.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

EARLY THIS MORNING BEFORE 12Z...PRIMARILY VFR WITH SCT CLOUDS AOA
4000 FT. PATCHY 2 TO 5 MI FOG IN THE COUNTRYSIDE TAF LOCATIONS
BUT CONFIDENCE IS LESS THAN IT WAS AT THIS TIME YDY. TEMP-DEWPOINT
SPREADS AT MIDNIGHT ARE JUST TOO LARGE. LIGHT S-SW WIND.

TODAY AFTER 12Z...VFR SCT AOA 5000 FT. BRIEFLY BKN CIGS NEAR 5000
FT VCNTY KABE AND KRDG THIS AFTN AND SLIGHT CHC OF A TSTM THERE
AFTER 22Z. SW WIND G 17 KT THIS AFTN MOST TAF LOCATIONS.

TONIGHT...VFR CIGS WITH A BETTER CHC OF BRIEF IFR CONDS IN
TSTMS. LIGHT SW WIND SHIFT N TOWARD MORNING WHEN PATCHY IFR ST/FOG
MIGHT FORM IN THE FRONTAL ZONE OR WHERE IT RAINS THIS EVENING.

OUTLOOK...
THURSDAY...MVFR AND IFR CONDITIONS AT TIMES IN SHOWERS AND THUNDERSTORMS.
PATCHY FOG THU MORNING.

THURSDAY NIGHT THROUGH SATURDAY...MAINLY VFR.

SUNDAY...SUB-VFR POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS.

&&

.MARINE...
NO HEADLINES THROUGH WEDNESDAY NIGHT.

MAINLY S-SW WIND G UNDER 20 KT SHIFT TO NORTH TOWARD DAWN THURSDAY.

WAVE HEIGHTS ON OUR OCEAN WATERS SHOULD BE 2 TO 4 FEET. WAVES ON
DELAWARE BAY ARE EXPECTED TO BE 2 FEET OR LESS.

SCATTERED THUNDERSTORMS TONIGHT.

OUTLOOK...
THURSDAY THROUGH SUNDAY...HIGH PRESSURE OVERHEAD WILL KEEP SEAS AND
WINDS BELOW SCA CRITERIA.

&&

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

&&

$$
SYNOPSIS...HEAVENER
NEAR TERM...DRAG 1231A
SHORT TERM...DRAG 1231A
LONG TERM...HEAVENER
AVIATION...DRAG/HEAVENER
MARINE...DRAG/HEAVENER





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