Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 200235
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
935 PM EST WED NOV 19 2014

.SYNOPSIS...
HIGH PRESSURE SLIDES OFFSHORE TONIGHT AND IS FOLLOWED BY A COLD
FRONTAL PASSAGE ON THURSDAY. BEHIND THIS FRONT, A STRONGER HIGH
PRESSURE SYSTEM WILL MOVE IN FROM THE WEST ON FRIDAY, AND CREST
OVER THE REGION ON SATURDAY BEFORE MOVING OFFSHORE ON SUNDAY.
MEANWHILE, LOW PRESSURE WILL DEVELOP ACROSS THE INTER-MOUNTAIN
WEST, AND TRACK NORTHEASTWARD TO LAKE MICHIGAN. THIS LOW WILL
BRING A COLD FRONT THROUGH THE REGION EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
MID LEVEL CLOUDS WERE DEVELOPING OVERHEAD IN THE WEAK WARM
ADVECTION IN ADVANCE OF AN APPROACHING COLD FRONT. THE CLOUDS AND
THE SOUTH TO SOUTHWEST SURFACE FLOW SHOULD PREVENT TEMPERATURES
FROM DROPPING MUCH OVERNIGHT. WE CONTINUE TO EXPECT MINIMUM
TEMPERATURES TO BE MOSTLY IN THE 20S.

THERE REMAINS A CHANCE FOR SNOW FLURRIES IN THE ELEVATED TERRAIN
OF THE POCONOS AND FAR NORTHERN NEW JERSEY OVERNIGHT.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
SOUTHERLY FLOW WILL GIVE WAY ONCE AGAIN TO WESTERLY BEHIND THE
COLD FRONT. STILL VERY DRY NO PRECIPITATION EXPECTED FROM THIS
WITH THE EXCEPTION OF A FLURRY FOR THE POCONOS AND MORNING CLOUDS.
THE MAIN CHALLENGE WILL BE THE FRONTAL TIMING AND TEMPERATURES.
THE ECMWF IS SLOWER AND WARMER GIVING PHL A GOOD SHOT TO GET WELL
INTO THE 40`S. HOWEVER THE GFS IS FASTER WITH PHL BARELY HITTING
40. FRONTAL PASSAGE NW OF PHL SHOULD OCCUR IN THE MORNING,
LIMITING THE MODEL SPREAD FOR TEMPERATURES IN THIS REGION. A
SLOWER FRONTAL PASSAGE ALLOWS FOR COASTAL AREAS TO SEE MORE
SOUTHERLY FLOW AND MAKE A RUN AT 50. WENT A COUPLE OF DEGREES
BELOW MAV/MET NORTHWEST GIVEN NW FLOW AND WENT ABOVE MAV/MET ALONG
THE COAST DUE TO THE SOUTHERLY FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
HIGHLIGHTS...

* TEMPERATURES WELL BELOW NORMAL FRIDAY W/SNOW SHOWERS POSSIBLE IN
  THE POCONOS
* CHANCE OF RAIN LATE SUNDAY INTO EARLY NEXT WEEK W/TEMPERATURES
  ABOVE NORMAL
* TEMPERATURES PROJECTED TO RETURN TO SEASONABLE LEVELS MID-WEEK

DETAILS...

A PATTERN CHANGE IS UNDERWAY AS THE PERSISTENT BLOCKING PATTERN
ALONG THE WEST COAST OF NOAM /POSITIVE HEIGHT ANOMALIES/ BREAKS
DOWN...ALLOWING A VIGOROUS S/WV TO MOVE INTO THE FOUR CORNERS
REGION ON SATURDAY...LEADING TO STRONG DOWNSTREAM HEIGHT RISES
ACROSS THE E CONUS, W/THE MID-LEVEL TROUGH GRADUALLY LIFTING TO
THE NORTHEAST ON FRIDAY AND RIDGING TAKING ITS PLACE BY MONDAY.
THIS WILL LEAD TO A WARMING TREND...WITH MAXIMUM TEMPERATURES WELL
BELOW NORMAL ON FRIDAY MODERATING TO ABOVE NORMAL LEVELS BY
MONDAY.

THE GFS...ECMWF AND THEIR RESPECTIVE ENSEMBLES ARE IN GENERAL
AGREEMENT ON TAKING THE SOUTHERN STREAM S/WV INTO THE FOUR-
CORNERS REGION ON SATURDAY...BUT DIFFER ON THE STRENGTH OF THE
NORTHERN STREAM S/WV COMING ASHORE IN THE PACIFIC NORTHWEST AT
THAT TIME. THIS HAS IMPLICATIONS FOR THE DEGREE OF DOWNSTREAM
PHASING OVER THE UPPER MS VALLEY ON SUNDAY AND THE EVOLUTION OF
THE RESULTANT STORM SYSTEM. THE MODELS AGREE ON A STORM TRACK OVER
THE MICHIGAN PENINSULA...BUT THE WEAKER NORTHERN STREAM SHORTWAVE
HAS LEAD TO A FASTER SOLUTION BY 24-HOURS...W/THE LOW NOW PROGGED
OVER THE MICHIGAN PENINSULA AT 12Z MONDAY. BUT AT D+5 IT/S TOUGH
TO SPECULATE IF THIS TRACK AND TIMING WILL HOLD.

NEVERTHELESS...THE PATTERN FAVORS A STORM TRACK TO THE WEST OF
THE APPALACHIANS AS WELL AS WARMER AIR MOVING INTO THE E CONUS...
BUT UNCERTAINTY IN THE TRACK AND STRENGTH OF THIS STORM SYSTEM
TRANSLATES INTO UNCERTAINTY IN THE TEMPERATURE FORECAST SUNDAY AND
BEYOND. LOOKING AHEAD TO TUESDAY AND WEDNESDAY...A FRONTAL PASSAGE
DURING THIS TIME FRAME LOOKS TO DELIVER A REINFORCING SHOT OF COLD
AIR...WHILE CYCLOGENSIS MAY TAKE PLACE INVOF THE EAST COAST, WHICH
BEARS WATCHING AS THE NAO IS PROJECTED TO GO NEGATIVE.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. CEILINGS MAY
LOWER INTO THE 4500 TO 5500 FOOT RANGE FOR A TIME LATE TONIGHT
INTO THURSDAY MORNING AT KRDG AND KABE. CEILINGS SHOULD REMAIN AT
OR ABOVE 8000 FEET OVER OUR REMAINING TAF SITES. THE CLOUD COVER
SHOULD BECOME SCATTERED FOR LATE THURSDAY MORNING AND THURSDAY
AFTERNOON.

A SOUTHERLY WIND AT 5 TO 10 KNOTS THIS EVENING SHOULD VEER TO THE
SOUTHWEST AND WEST OVERNIGHT. A WEST WIND AROUND 8 TO 12 KNOTS
WITH GUSTS NEAR 20 KNOTS IS ANTICIPATED FOR THURSDAY.

OUTLOOK...

FRIDAY...VFR. NORTHWEST WINDS MAY GUST TO 25 KNOTS DURING THE
LATE MORNING THRU EARLY AFTERNOON HOURS.

SATURDAY...VFR.

SUNDAY AND MONDAY...MVFR POSSIBLE IN LOW CEILINGS AND -SHRA
ESPECIALLY LATE SUNDAY AND PARTICULARLY ON MONDAY.

&&

.MARINE...
SEAS AND WINDS SHOULD INCREASE THIS EVENING. THE ENVIRONMENT WILL
BE FAVORABLE FOR SOME SOUTHWEST GALE FORCE WIND GUSTS AROUND 35
KNOTS ON THE OCEAN WATERS FROM 04-12Z THURSDAY. A GALE WARNING IS
IN EFFECT. THE GALE GUSTS MAY NOT BE SUSTAINED THROUGH THIS WHOLE
PERIOD BUT MAY BE MORE OF A INTERMITTENT VARIETY. SCA CONDITIONS
LIKELY WILL CONTINUE THROUGHOUT THE DAY THURSDAY WITH
NORTHWESTERLY WINDS.

OUTLOOK...

FRIDAY...SCA WINDS AND SEAS LIKELY THURSDAY NIGHT AND FRIDAY...
SLOWLY SUBSIDING TO SUB-SCA CONDITIONS FRIDAY NIGHT.

SATURDAY AND SUNDAY...SUB-SCA CONDITIONS ARE ANTICIPATED ATTM.

MONDAY...A GALE WARNING MAY BE NEEDED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 7 AM EST THURSDAY FOR ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR ANZ430-431.

&&

$$

SYNOPSIS...FRANCK
NEAR TERM...IOVINO
SHORT TERM...GAINES
LONG TERM...FRANCK
AVIATION...FRANCK/IOVINO
MARINE...FRANCK/GAINES






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