Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 210847
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
347 AM EST FRI NOV 21 2014

.SYNOPSIS...
STRONG HIGH PRESSURE FROM THE LOWER OHIO VALLEY WILL BUILD INTO
OUR AREA TODAY THROUGH SATURDAY. THE HIGH WILL MOVE OFFSHORE
SATURDAY NIGHT. A WARM FRONT WILL LIFT ACROSS OUR AREA SUNDAY
NIGHT AND MONDAY AS A STRONG LOW PRESSURE SYSTEM TRACKS INTO THE
GREAT LAKES REGION. A COLD FRONT IS FORECAST TO MOVE THROUGH LATER
MONDAY NIGHT AND TUESDAY, FOLLOWED BY HIGH PRESSURE LATE WEDNESDAY
AND THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A 1030 MB SURFACE HIGH WAS CENTERED OVER THE MIDWEST OVERNIGHT WHILE
THE COLD FRONT THAT MOVED THROUGH THE CWA YESTERDAY WAS LOCATED OFF
THE NORTHEAST COAST AND THE SOUTHERN MID-ATLANTIC STATES. THE LATEST
WATER VAPOR SATELLITE LOOP CAPTURES A POLAR TROUGH DIGGING INTO THE
GREAT LAKES AND NORTHEAST STATES. WEST-NORTHWEST FLOW AROUND THE
BASE OF THE TROUGH WILL CONTINUE TO USHER IN COLD AIR THIS MORNING.
THE END RESULT WILL BE DAY 3 THIS WEEK OF WINTER-LIKE TEMPERATURES
FOR THE FORECAST AREA.

FORECAST SOUNDINGS FROM THE LATEST MODEL GUIDANCE SHOWS A DEEP MIXED
LAYER AROUND 4-5 KFT THIS AFTERNOON. FORECAST 850 MB TEMPS OF AROUND
-14C TODAY, WHICH WOULD BE 1 TO 2C HIGHER THAN IT WAS THIS PAST
TUESDAY-WEDNESDAY, WAS A REASONABLE PROXY FOR DETERMINING FULL
HEATING POTENTIAL. THIS TRANSLATES TO HIGHS IN THE MID 30S (EXCEPT
MID TO UPPER 20S IN THE MOUNTAINS).

WINDS WILL BE BREEZY THIS MORNING WITH 20-30 MPH GUSTS BEFORE IT
GRADUALLY RELAXES THIS AFTERNOON AS HIGH PRESSURE BUILDS INTO THE
AREA.

BOUNDARY-LAYER FLOW WILL VEER SLIGHTLY OUT OF THE NORTHWEST EARLY
THIS MORNING, CAUSING A LAKE EFFECT SNOW BAND NEAR BGM TO SHIFT
SOUTHWARD. IF IT IS ABLE TO MAINTAIN ITSELF ENOUGH DOWNWIND, THE
POCONOS AND THE NORTHWESTERN TIP OF SUSSEX COUNTY MAY SEE A FEW
FLURRIES THIS MORNING. LITTLE OR NO ACCUMULATION IS EXPECTED. THERE
MAY ALREADY BE FLURRIES OCCURRING BUT THE RADAR WOULD OVERSHOOT ANY
OF THESE SNOW SHOWERS OR FLURRIES IN OUR FAR NORTHWEST ZONES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HIGH PRESSURE WILL BUILD SOUTHEASTWARD TONIGHT WITH THE CENTER OF
THE HIGH SETTLING OVER THE SOUTHERN MID-ATLANTIC STATES. WAA WILL
OCCUR OVERHEAD TONIGHT AS THE 925-850 MB  RIDGE BUILDS EASTWARD. DO
NOT EXPECT THE WARM AIR ALOFT TO HAVE MUCH OF AN IMPACT ON SURFACE
TEMPS AS THE BOUNDARY LAYER DECOUPLES UNDER A GOOD RADIATIONAL
COOLING SETUP. MIN TEMP FORECAST WEIGHTED MORE TOWARD THE COLDER MAV
GUIDANCE. TEMPS ARE EXPECTED TO BOTTOM OUT IN THE MID TO UPPER TEENS
IN THE MORE RURAL AREAS AND LOW TO MID 20S IN THE URBAN AND COASTAL
LOCALES.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE WEATHER PATTERNS CHANGE SOMEWHAT ACROSS THE REGION DURING THE
LONGER TERM PARTS OF THE FCST. THE MEAN TROUGH ACROSS NORTH AMERICA
REMAINS...BUT THE COLDEST AIR MOVES AWAY SAT/EARLY SUN AS SOME
PROGRESSIVE RIDGING MOVES ACROSS THE ERN U.S. MORE COLDER AIR BEGINS
TO BUILD UP ACROSS CNTRL CANADA TOWARDS NEXT WEEKEND.

TEMPERATURES...COLD SAT WITH READINGS STILL SOME 10 DEGREES BELOW
NORMAL. BY SUNDAY READINGS WILL BE CLOSE TO NORMAL WITH THE HIGH
PRESSURE SYSTEM PASSING EAST OF THE REGION. MUCH ABOVE NORMAL TEMPS
ARE IN STORE FOR MONDAY...WHEN HIGHS WILL REACH THE MID/UPPER 60S IN
MOST AREAS WITH SOME 70S ALSO POSSIBLE. TEMPERATURES WILL FALL BACK
TO NEAR NORMAL TUESDAY...THEN A BIT BELOW NORMAL FOR THE REST OF THE
WEEK. NORMAL TEMPS : PHL/ACY...MAX 50-52..MIN 35-37. RDG/ABE...MAX
48-50..MIN 30-32 GED...MAX 52-54..MIN 33-35.

PRECIPITATION...DRY SAT THEN A CHC FOR SOME LIGHT MIXED PCPN ACROSS
THE FAR NORTH FOR SAT NIGHT. MOSTLY DRY SUN...THEN CATEGORICAL POPS
FOR RAIN SUN NIGHT...DECREASING TO CHC MON AND MON NIGHT. TUE/WED
DRY ACROSS MOST AREAS...BUT SMALL CHC FOR RAIN ALONG THE COAST AS
THE OP MODELS SHOWING A LOW MOVING JUST E OF THE AREA THEN.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

VFR TODAY AND TONIGHT. W-NW WINDS AROUND 10-15 KT WILL GUST 20-25 KT
SHORTLY AFTER SUNRISE. THE WINDS DO SUBSIDE IN THE AFTERNOON
ALTHOUGH GUSTS TO 20 KT ARE STILL POSSIBLE. WINDS WILL DIMINISH TO
UNDER 10 KT TOWARD SUNSET AND BECOME LIGHT/VARIABLE TONIGHT.

OUTLOOK...
SAT THRU SUN...VFR EXPECTED. INCREASING CLOUDS SUN.
SUN NIGHT THRU MON NIGHT...LOWER CONDITIONS POSSIBLE IN RAIN/FOG.
TUE...MOSTLY VFR.

&&

.MARINE...
THE FORECAST GALES HAVE FOR THE MOST PART FAILED TO MATERIALIZE AS
STRONGER GUSTS HAVE NOT MIXED DOWN QUITE AS EFFECTIVELY AS EXPECTED.
HOWEVER, THE LATEST DOWNSTREAM OBSERVATIONS AND HIRES MODEL GUIDANCE
INDICATES A SURGE OF COLDER AIR ABOUT TO MOVE OVER THE WATERS. STILL
EXPECT PREDOMINATELY SCA-LEVEL WINDS BUT THE POTENTIAL FOR A FEW
GUSTS TO GALES WILL BE HIGHEST EARLY THIS MORNING. WILL THEREFORE BE
CONSERVATIVE AND KEEP THE GLW UP FOR THE LOWER DE BAY AND ATLANTIC
ZONES THRU 7 AM. AFTER GLW EXPIRES, A SCA WILL BE NEEDED FOR TODAY.

SUB-SCA WINDS AND SEAS EXPECTED FOR TONIGHT.

OUTLOOK...
SAT/SAT NIGHT...LOW END SCA CONDITIONS EXPECTED.
SUN...SUB-SCA CONDITIONS.
SUN NIGHT THRU MON NIGHT...SCA CONDITIONS POSSIBLE.
TUE...SCA CONDITIONS POSSIBLE EARLY ON THE OCEAN.


&&

.FIRE WEATHER...
A REINFORCING SHOT OF COLD AIR TODAY WILL BE ACCOMPANIED BY BREEZY
NORTHWEST AND VERY DRY AIR. FREQUENT WEST-NORTHWEST GUSTS BETWEEN 20
AND 30 MPH ARE EXPECTED THIS MORNING BEFORE WINDS START TO WEAKEN
THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. FORECAST MINIMUM RHS ARE
GENERALLY IN THE LOWER 30S BUT MAY REACH THE 30 PERCENT RED FLAG
CRITERIA IN A FEW SPOTS THIS AFTERNOON.

HOWEVER, THESE MIN RHS THIS AFTERNOON MAY NOT COINCIDE WITH THE
FREQUENT 20 MPH GUSTS, WHICH WOULD LOWER THE FIRE WEATHER THREAT.
YESTERDAY`S FUEL MOISTURE OBSERVATIONS OBTAINED FROM THE NFDRS WAS
BELOW 10 PERCENT IN THE DAY AREA. WE WILL LET THE DAY SHIFT
COORDINATE WITH STATE OFFICIALS BEFORE ANY ENHANCED FIRE WEATHER
STATEMENT IS ISSUED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 7 AM EST THIS MORNING FOR ANZ431-450>455.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLEIN
SHORT TERM...KLEIN
LONG TERM...O`HARA
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA
FIRE WEATHER...






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