Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 190134
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
934 PM EDT SAT OCT 18 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE MID-ATLANTIC STATES SUNDAY NIGHT
AND MOVE OFFSHORE ON MONDAY. BY TUESDAY A COLD FRONTAL BOUNDARY WITH
AN AREA OF LOW PRESSURE WILL DIVE SOUTHEAST FROM THE GREAT LAKES
INTO THE MID-ATLANTIC STATES. ANOTHER LOW PRESSURE WILL FORM OFF THE
CAROLINA COASTLINE. THESE TWO LOW PRESSURE SYSTEMS WILL INTERACT
WITH EACH OTHER AND MERGE JUST OFFSHORE WEDNESDAY AND THURSDAY,
DEPARTING THE REGION BY FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MOST OF THE ISOLATED-SCATTERED SHOWERS THAT WERE TO OUR NORTHWEST
HAVE MOSTLY DISSIPATED AS DAYTIME HEATING HAS BEEN LOST, EXCEPT
FOR A FEW SHOWERS/SPRINKLES MOVING ACROSS THE NORTHERN THIRD OF
THE AREA. THERE MAY STILL BE A FEW ISOLATED SHOWERS OR SPRINKLES
THIS EVENING, BUT NOT MUCH MORE FOR THE REMAINDER OF THE NIGHT. WE
GENERALLY EXPECT PARTLY TO MOSTLY CLOUDY SKIES FOR THE OVERNIGHT
PERIOD.

THE GUSTS WILL CONTINUE TO DROP OFF THROUGH THE OVERNIGHT, BUT A
STEADY BREEZE IS EXPECTED TO CONTINUE THROUGH THE NIGHT. THIS
WILL KEEP THE BOUNDARY LAYER WELL MIXED, SO EVEN WITH THE COOLER
DEWPOINTS AND AIRMASS IN PLACE, TEMPERATURES WILL ONLY BE ABLE TO
DROP INTO THE LOW TO MID-40S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SECONDARY COLD FRONT CONTINUES TO PUSH THROUGH TOMORROW LATE MORNING
AND WE SEE ANOTHER BOUT OF STRONGER NORTHWEST WIND GUSTS WITH MUCH
BETTER COLD AIR ADVECTION TAKING PLACE. THE FRONTAL PASSAGE, WITH
NOT MUCH MOISTURE TO WORK WITH, SHOULD BE DRY AS IT PUSHES THROUGH
BUT THE AIRMASS WILL BE NEARLY 10-15 DEGREES COLDER THAN TODAY`S.
HIGHS WILL END UP BEING IN THE LOW TO MID-50S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
SUNDAY NIGHT: HIGH PRESSURE WILL BE LOCATED TO OUR SOUTH. THIS WILL
RESULT IN CLEAR SKIES AND LIGHT WINDS, GOOD SET-UP FOR RADIATIONAL
COOLING. DEWPOINTS BY BOTH THE ECMWF AND GFS IN THIS PERIOD ARE
MODELED IN THE MID TO UPPER 20`S. CURRENT THINKING IS THE GFS AND
THE RESPECTIVE MAV GUIDANCE ARE TO AGGRESSIVE WITH COOLER LOW
TEMPERATURES. EVEN WITH THAT THE MET GUIDANCE HAS LOWS RIGHT
AROUND FREEZING ACROSS THE NORTHWEST PORTION OF THE CWA. MODERATE
CONFIDENCE IS CURRENTLY PRESENT FOR A FREEZE EVENT ACROSS CARBON,
MONROE AND SUSSEX COUNTIES SO A FREEZE WATCH HAS BEEN ISSUED.

MONDAY AND MONDAY NIGHT: STILL LOOKS LIKE A NICE DAY AS HIGH PRESSURE
MOVES OFFSHORE, LIGHT WINDS BECOMING SOUTHWEST. CLOUDS BEGIN TO
INCREASES MONDAY NIGHT AHEAD OF THE NEXT COLD FRONTAL SYSTEM TO
IMPACT THE REGION KEEPING TEMPERATURES UP. FAIRLY LIMITED
TEMPERATURE SPREAD AMONG THE VARIOUS TEMPERATURE FORECASTING TOOLS
WITH HIGHS AROUND 60 FOR MOST OF THE AREA, COOLER NW.

TUESDAY THROUGH THURSDAY NIGHT: A COASTAL LOW PRESSURE SYSTEM WILL
DEVELOP OFFSHORE AND BE SLOW TO MOVE NORTHEAST THROUGHOUT THIS
PERIOD. THE END RESULT WILL BE GRAY GLOOMY COOLER DAYS FEATURING
RAIN SHOWERS AND SOME NORTHWESTERLY WINDS BY THE END OF THIS PERIOD. THE
FORMATION OF THIS LOW PRESSURE WILL START WITH TWO PIECES, A STRONG
UPPER LEVEL LOW AND COLD FRONT DIVING FROM THE GREAT LAKES INTO THE
MID-ATLANTIC AND A LOW PRESSURE FORMING OFF THE CAROLINAS. THE UPPER
LOW AND COLD FRONTAL BOUNDARY WILL BEGIN TO BRING SOME SCATTERED
SHOWERS ON TUESDAY TO THE REGION WITH A MOISTURE PLUME FROM THE
CAROLINA LOW WELL OFFSHORE. BY TUESDAY NIGHT WE BEGIN TO SEE MORE
INTERACTION BETWEEN THE FEATURES, PHASING. THE MAIN LOW FORMS OFF
THE SOUTHERN NEW ENGLAND COASTLINE BY WEDNESDAY WITH THE MAJORITY
OF ATLANTIC MOISTURE BROUGHT INTO SOUTHERN NEW ENGLAND. TO COMPARE
OUR REGION WOULD BE FAVORED FOR JUST SOME WRAP AROUND SHOWERS.

THE LAST TWO ECMWF RUNS SHOW AN INTERESTING INVERTED TROUGH FEATURE
WHICH ENHANCES SOME OF THE SHOWER ACTIVITY. ON THE OTHER HAND THE
OPERATIONAL GFS AND CMC KEPT A GOOD PORTION OF THE AREA DRY
THROUGHOUT MOST OF THIS PERIOD. IN TERMS OF THE ENSEMBLES SEVERAL WETTER
MEMBERS WERE PRESENT IN THE 06Z GEFS WHILE THE 00Z ECMWF SEEMED TO
BE A LITTLE FURTHER SOUTHEAST COMPARED TO IT`S ENSEMBLE MEAN. THE
NAO IS LIKELY TO BE NEAR NEUTRAL, WHICH DOESN`T INSPIRE CONFIDENCE
THAT THE SYSTEM WILL STAY CLOSER TO THE COASTLINE THAN CURRENTLY
MODELED. CONFIDENCE IS INCREASING SOMEWHAT THAT THIS PERIOD WILL
BE DOMINATED BY SOME SCATTERED SHOWERS STARTING TUESDAY AND
LASTING THROUGH THURSDAY WITH AREAS FURTHER NORTHEAST CLOSER TO
THE LOW STANDING THE BEST CHANCE TO SEE A MORE WIDESPREAD
RAINFALL. WITH PLENTY OF CLOUDS, LOW TEMPERATURES WILL STAY UP AT
NIGHT CLOSE TO 50 FOR MOST OF US WHILE HIGHS STRUGGLE INTO THE LOW
60`S, COOLER NW. NOT MUCH SPREAD IN THE MODELS AND THERE
ENSEMBLES/ STATISTICAL GUIDANCE ON TEMPERATURES. IN TERMS OF TIDES
ONCE A BETTER HANDLE OF THE LOW PRESSURE POSITION AND WIND
DIRECTION ARE ESTABLISHED CONFIDENCE WILL INCREASE ON WHAT IF ANY
TIDAL ISSUES WILL BE PRESENT.


FRIDAY THROUGH SATURDAY: LOW PRESSURE SYSTEM FINALLY DEPARTS WITH
HIGH PRESSURE BUILDING BACK IN AT THE VERY END OF THE PERIOD. WENT
ON THE WARMER END OF THE MODEL SUITE FOR HIGH TEMPERATURES ON
SATURDAY CLOSER TO MEX GUIDANCE GIVEN REBOUNDING 925/850 MB TEMPS.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

TONIGHT...VFR. GUSTY NW WINDS DROP OFF SOME BUT WE KEEP THE HIGHER
SUSTAINED THROUGH THE OVERNIGHT HOURS. STRATOCU DECK BEGINS TO THIN
AND SCATTER OUT LATE TONIGHT.

SUNDAY...VFR. MORE GUSTY NW WINDS, AROUND 25 TO 30 KNOTS, WILL
COMMENCE BY LATE MORNING.

OUTLOOK...
SUNDAY NIGHT THROUGH MONDAY NIGHT: VFR WEST WINDS 5 TO 10 KNOTS SHIFTING
TO SOUTHWEST MONDAY. SOME HIGHER GUSTS EARLY IN THE EVENING.

TUESDAY...SOME RESTRICTIONS TO MVFR WITH SCATTERED SHOWERS.

TUESDAY NIGHT THROUGH THURSDAY... MAINLY MVFR CONDITIONS WITH
SCATTERED SHOWERS. NORTH TO NORTHWEST WINDS WEDNESDAY AFTERNOON
THROUGH THURSDAY FROM 10-15 KNOTS WITH HIGHER GUSTS.

&&

.MARINE...
TONIGHT - SUNDAY...SCA CONDITIONS PERSIST ACROSS ALL OUR WATERS
THROUGH LATE SUNDAY NIGHT. GUSTY NORTHWEST WINDS, AROUND 25 TO 30
KNOTS, WILL CONTINUE...AT THE MOUTH OF THE BAY WE COULD SEE CLOSE TO
GALE FORCE GUSTS WITH THE POTENTIAL WIND FUNNELING. SEAS WILL REMAIN
ELEVATED AROUND 4 TO 7 FEET ON THE OCEANFRONT.

OUTLOOK...
SUNDAY NIGHT: EARLY IN THE EVENING SEAS ARE STILL LIKELY TO BE
AROUND FIVE FEET WITH SOME HIGHER GUSTS AROUND 25 KNOTS FROM THE NORTHWEST.
THESE VALUES WILL BE DECREASING BELOW SCA THRESHOLD EARLY AND WILL
ALLOW THE SCA TO EXPIRE EARLY SUNDAY EVENING.

MONDAY THROUGH WEDNESDAY MORNING: SEAS AND WINDS BELOW SCA CRITERIA
BUT INCREASING WEDNESDAY MORNING WITH THE DEVELOPMENT OF A LOW
PRESSURE TO OUR NORTHEAST.

WEDNESDAY AFTERNOON THROUGH THURSDAY: OVERALL THINKING IS THAT
WAVEWATCH IS UNDERDONE. SEAS WILL LIKELY OR OVER FIVE FEET THROUGH
MOST OF THIS PERIOD. NORTHWEST WIND GUSTS OVER 25 KNOTS ARE ALSO
POSSIBLE.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FREEZE WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY MORNING FOR
     PAZ054-055.
NJ...FREEZE WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY MORNING FOR
     NJZ001.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT SUNDAY NIGHT FOR
     ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR ANZ430-431.

&&

$$

SYNOPSIS...GAINES
NEAR TERM...ROBERTSON/HEAVENER
SHORT TERM...HEAVENER
LONG TERM...GAINES
AVIATION...GAINES/HEAVENER
MARINE...GAINES/HEAVENER







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