-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPHI 242132
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
432 PM EST TUE FEB 24 2015

.SYNOPSIS...
HIGH PRESSURE IS SHIFTING OFFSHORE. LOW PRESSURE ALONG THE SOUTHEAST
COAST OF THE UNITED STATES SCOOTS NORTHEASTWARD OUT TO SEA
WEDNESDAY. A COLD FRONT WILL PASS ACROSS OUR AREA LATE WEDNESDAY, AS
A MORE POTENT LOW PRESSURE SYSTEM ALONG THE GULF COAST HEADS
NORTHEAST. THAT LOW RACES OUT TO SEA WELL TO OUR EAST ON THURSDAY.
STRONG ARCTIC HIGH PRESSURE CENTERED IN MONTANA WILL ARRIVE ALONG
THE MID ATLANTIC COAST THIS COMING WEEKEND, THEN A COLD FRONT
PROBABLY CROSSES OUR AREA SUNDAY NIGHT OR MONDAY. A MORE IMPORTANT
AREA OF LOW PRESSURE SHOULD APPROACH FROM THE SOUTHWEST ON
TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
TWO SYSTEMS OF CONCERN TONIGHT, ALTHOUGH NEITHER IS EXPECTED TO
BRING SIGNIFICANT WEATHER TO THE AREA. FIRST IS THE LOW PRESSURE
SYSTEM WELL TO OUR SOUTH OFF THE SOUTHEAST COAST. THIS ACTUAL LOW
WILL REMAIN WELL SOUTH OF THE AREA, BUT AS THE SOUTHERN STREAM SHORT
WAVE MOVES OFF THE COAST, A SECONDARY AREA OF LOW PRESSURE IS
FORECAST TO DEVELOP NORTH OF THE MAIN LOW, AND TRACK TO OUR EAST AND
NORTHEAST. EVEN THIS SECONDARY LOW LOOKS TO STAY FAR ENOUGH EAST OF
THE AREA THAT MOST OF ITS PRECIPITATION SHOULD STAY OFFSHORE,
ALTHOUGH IT MAY BRING SOME VERY LIGHT PRECIPITATION TO OUR EXTREME
SOUTH AND COASTAL AREAS. THE ONLY PLACES THAT MIGHT GET SOME LIGHT
SNOW ON THE OUTSKIRTS OF THE SYSTEM WOULD BE SOUTHERN DELAWARE AND
COASTAL NEW JERSEY, SO WE KEEP A SLIGHT CHANCE OF SNOW HERE. NO
ACCUMULATION IS EXPECTED.

THE SECOND IS A FRONTAL BOUNDARY ASSOCIATED WITH LOW PRESSURE MOVING
ACROSS SOUTHERN CANADA OVERNIGHT. THERE IS NOT MUCH SIGNIFICANT
MOISTURE ASSOCIATED WITH THE SYSTEM. THE MAIN VORTICITY WITH THE
SHORT WAVE ALOFT IS FORECAST TO PASS NORTH OF THE AREA, BUT OUR FAR
NORTHERN AREAS MAY BE CLOSE ENOUGH THAT SOME SNOW SHOWERS MAY
DEVELOP, SO WE INCLUDE A SLIGHT CHANCE HERE AS WELL.

OVERNIGHT LOWS ARE EXPECTED WARMER THAN LAST NIGHT, BUT WILL STILL
BE 10-15 DEGREES BELOW NORMAL.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
A SECONDARY COLD FRONT WILL PUSH THROUGH THE AREA DURING THE DAY
WEDNESDAY. NO PRECIPITATION IS EXPECTED DURING THE DAY WITH THE
FRONT. THE FRONT WILL HELP INCREASE WINDS ACROSS THE AREA, WITH
WINDS GUSTING AROUND 20-25 MPH AT TIMES DURING THE DAY. THE GOOD
NEWS IS HIGHS WILL BE ABOUT 10 DEGREES WARMER THAN TODAY, BUT WITH
THE WIND IT WILL FEEL COLDER.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
500MB: PREDOMINANTLY WEST OR WEST SOUTHWEST FLOW THROUGH EARLY NEXT
WEEK. A SHORT WAVE IN THE SOUTHERN STREAM WEDNESDAY NIGHT ZIPS ENE
OFF THE MID ATLANTIC COAST INTO THE CONFLUENCE ZONE WITH THE NORTHERN
STREAM. SEVERAL WEAK SHEAR RELATED SHORT WAVES CROSS THE AREA
THEREAFTER BUT ARE GENERALLY DRY DUE TO THE OVERWHELMING SUBSIDENCE
ASSOCIATED WITH THE APPROACHING ARCTIC HIGH. EARLY NEXT WEEK THERE
SHOULD BE A MUCH MORE SUBSTANTIAL WARM AIR ADVECTION PRECIPITATION
PATTERN WITH A MODELED 180 KT 250 MB JET CORE OVER MAINE...RRQ FOR
OUR AREA ON TUESDAY.

TEMPERATURES...WE HOPE THE CLIMATE SECTION HAS CONSIDERABLE
USEFUL INFORMATION NOT ONLY FOR FEBRUARY BUT ALSO A COMPARISON TO
JANUARY AND THE HISTORICAL DATABASE. CALENDAR DAY TEMPERATURES
THURSDAY-SATURDAY SHOULD AVERAGE 14 TO 20 DEGREES BELOW NORMAL.
THEN 10 TO 15 DEGREES BELOW NORMAL SUNDAY; 0 TO 5 BELOW NORMAL
MONDAY AND NEAR NORMAL TUESDAY AS WE DELAY THE WARMING 24 HOURS
EACH DAY WE DO THIS AFTERNOON EXTENDED PRODUCT.

FORECAST BASIS:  UNLESS OTHERWISE NOTED, 50 50 BLEND 12Z/24 GFS/NAM
MOS GUIDANCE WEDNESDAY NIGHT-THURSDAY NIGHT, 12Z/24 MEX MOS FRIDAY
AND FRIDAY NIGHT THEN THE 15Z/24 WPC GRIDDED ELEMENTS OF MAX/MIN
TEMP, 12 HOUR POP, 6 HOUR DEWPOINT-SKY-WIND FROM SATURDAY-NEXT
TUESDAY.


THE DAILIES BELOW...

WEDNESDAY NIGHT-THURSDAY...WATCHING THE NW EXTENT OF THE SNOW SHIELD
ASSOCIATED WITH THE SOUTHERN STREAM SHORT WAVE WHICH SHOULD FOR THE
MOST PART PASS OUT TO SEA WITH ONLY A LITTLE SNOW FOR POSSIBLY SRN
DELAWARE AND THE SOUTHERN TIP OF NJ. THERE SHOULD BE QUITE A BIT
OF CLOUD COVER NW OF THE SNOW SHIELD BUT FOR NOW THE THINKING IS
DRY AIR BELOW 5000 FT SHOULD RENDER THE NORTHERN EDGE OF THE .01
AS VIRGA. DESPITE LACK OF ATLANTIC EASTERLY INFLOW AT OUR LATITUDE
THIS NEEDS TO BE MONITORED FOR A SLIGHTLY LARGER RESPONSE THAN
NOW FORECAST. WE`VE MAINTAINED CONSIDERABLE CONTINUITY WITH THE
MID SHI9FT FORECAST. YOU`LL NOTE A CHANCE OF SNOW SHOWERS FURTHER
N ACROSS E PA AND WESTERN NJ ON THURSDAY BUT FOR NOW MY CONFIDENCE
IN THAT OCCURRENCE IS WELL BELOW AVERAGE.

THIS SHORT WAVE PASSAGE HOLDS UP THE ARRIVAL OF THE ARCTIC AIRMASS.
N-NE WIND WEDNESDAY NIGHT AND THURSDAY MORNING WITH GUSTS 15-20 MPH
ALONG AND SE OF I95.

CONFIDENCE ON THE OVERALL FORECAST SCENARIO FOR WEDNESDAY NIGHT-
THURSDAY: AVERAGE.

FRIDAY - SATURDAY...HIGH PRESSURE WILL BE IN CONTROL OVER THE REGION
WITH ZONALISH FLOW ALOFT TAKING SHAPE. A COUPLE MORE WELL BELOW AVERAGE
TEMPERATURE DAYS ARE EXPECTED. PARTLY CLOUDY SKIES ARE ANTICIPATED
BOTH DAYS WITH NORTHERLY GUSTS AROUND 20 MPH AND LESS OF A NORTHERLY
WIND SATURDAY. ITS NOT IMPOSSIBLE TO SEE SOME FLURRIES HERE AND
THERE FRIDAY BUT FOR NOW THESE ARE NOT IN THE FORECAST.

AS THE HIGH CRESTS OVER OUR AREA SATURDAY BAROMETRIC PRESSURE
SHOULD RISE CLOSE TO 30.8 INCHES.

RADIATIONAL COOLING WILL PROBABLY RENDER MOS GUIDANCE LESS
EFFECTIVE THAN THE APPLICATION OF THE GFS 2M TEMPS OVER THE
COUNTRYSIDE LOCATIONS SUCH AS KPTW, KABE, KFWN, KSMQ, KMIV.

CONFIDENCE ON THE OVERALL FORECAST SCENARIO FOR FRIDAY-SATURDAY:
AVERAGE.

SUNDAY...THICKENING CLOUDS AHEAD OF THE NEXT COLD FRONT. NOT NEARLY
AS COLD AFTER A POSSIBLE VERY EARLY MORNING RADIATING RECORD LOW
AT KACY? A PERIOD OF SNOW IS POSSIBLE IN THE AFTERNOON OR EVENING
IN THE WAA PATTERN AHEAD OF THIS NEXT COLD FRONT. LOWERED THE MAX
TEMPS AS FCST BY WPC WITH A BLEND OF THE 12Z/24 MEX AND EC 2M
TEMPS. 2M TEMPS AGAIN MAY PROVE MORE USEFUL IN FORECASTING THE LOW
TEMPS FOR THE NJ COUNTRYSIDE, PRIOR TO THE ARRIVAL OF WAA CLOUD
COVER NEAR DAYBREAK. MINS MAY BE AT 12010AM SUNDAY. CONFIDENCE:
AVERAGE.

MONDAY...CFP POSSIBLY ACCOMPANIED BY A PERIOD OF PRECIPITATION,
MAINLY EARLY. SEASONABLE. GUSTY NW WINDS POSSIBLE IN THE AFTERNOON?
CONFIDENCE: BELOW AVERAGE NOT ONLY ANY PRECIPITATION OCCURRENCE
AFTER 12Z BUT ALSO THE MAX TEMPS MIGHT BE FORECAST SEVERAL DEGREES
TOO WARM.

TUESDAY...JET DYNAMICS...WAA AND POOLING MOISTURE IN THE SOUTHERN
UNITED STATES FAVOR THE DEVELOPMENT A HEAVY PRECIPITATION EVENT.
TOO EARLY FOR DETAILS SINCE THE SYSTEM MAY END UP SLIGHTLY WEAKER
AND THEREFORE COLDER AND FURTHER EAST. ESSENTIALLY A MIXED PCPN
EVENT AT THIS DISTANT OUTLOOK. CONFIDENCE: AVERAGE OR ABOVE ON AN
EVENT BUT ONLY AVERAGE OR BELOW ON THE THERMAL PROFILES.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS ARE MOSTLY EXPECTED ACROSS THE TAF SITES. A PERIOD OF
MVFR CIGS IS POSSIBLE AT ABE/RDG OVERNIGHT. THE REST OF THE SITES
MAY EXPERIENCE SOME SCATTERED LOWER CLOUDS, BUT CIGS ARE EXPECTED TO
REMAIN VFR.

SOUTH-SOUTHEAST WINDS AROUND 5-10 KNOTS TODAY MAY BECOME LIGHT AND
VARIABLE AT MANY LOCATIONS THIS EVENING, BEFORE SHIFTING TO THE
SOUTHWEST BEHIND A FRONTAL BOUNDARY OVERNIGHT. DURING THE DAY
WEDNESDAY, WEST-NORTHWEST WINDS WILL LIKELY BEGIN GUSTING AROUND 20
KNOTS DURING THE LATE MORNING INTO THE AFTERNOON.

OUTLOOK...

WEDNESDAY NIGHT - THURSDAY MORNING...VFR CIGS. GUSTY N WINDS TO
15 OR 20 KT POSSIBLE I95 EWD. POSSIBLE LIGHT MVFR/IFR SNOW SOUTH
AND EAST OF PHL/ILG...COULD AFFECT MIV/ACY LATE THURSDAY MORNING
BEFORE MOVING OUT TO SEA.

THURSDAY AFTERNOON...VFR PARTIAL CLEARING.  N WIND GUST 15-20KT.

FRIDAY - SATURDAY...VFR. N WIND WIND GUST 15-20 KT FRIDAY AND
LESS SATURDAY.

SUNDAY...VFR CIGS. CHANCE OF MVFR CONDITIONS IN SNOW SUNDAY
AFTERNOON OR NIGHT. CHANCE OF LIGHT WIND.

&&

.MARINE...
SOUTH-SOUTHEAST WINDS WILL BECOME MORE SOUTHERLY THIS EVENING, THEN
SOUTHWEST-WEST OVERNIGHT AS A FRONTAL BOUNDARY MOVES ACROSS THE
AREA. AS LOW PRESSURE LIFTS TO OUR NORTHEAST OVERNIGHT INTO
WEDNESDAY, WINDS WILL INCREASE, ESPECIALLY AS A SECONDARY FRONTAL
BOUNDARY MOVES ACROSS THE AREA DURING THE DAY WEDNESDAY. THE
NORTHERN HALF OF THE ATLANTIC WATERS MAY BEGIN TO SEE SMALL CRAFT
ADVISORY CONDITIONS AROUND DAYBREAK WEDNESDAY AND CONTINUE THROUGH
THE DAY. SO A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE NORTHERN
HALF OF THE ATLANTIC WATERS. FOR THE SOUTHERN HALF OF THE ATLANTIC
WATERS AND DELAWARE BAY, THESE AREAS MAY BE FAR ENOUGH AWAY FROM THE
DEPARTING LOW THAT THE PRESSURE GRADIENT MAY NOT CONTRIBUTE ENOUGH
TO CREATE SMALL CRAFT ADVISORY CONDITIONS, SO NO ADVISORY FOR THE
REST OF THE AREA.


OUTLOOK...

WEDNESDAY NIGHT THROUGH THURSDAY... WINDS TURN NLY AND INCREASE
TO AROUND 20-25 KT WITH SCA POSSIBLE AT LEAST OFF SNJ AND THE DE
ATLC WATERS. ATLANTIC SEAS SHOULD BUILD TO 5 OR 6 FEET EAST OF S
NJ AND OVER THE ATLC DELAWARE WATERS.

FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT NORTH NORTHEAST
WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN ZONES TO SCA
HAZARDOUS SEAS OF 5 FT WITH A SHORT 5 SEC PERIOD. COASTAL FLURRIES
POSSIBLE FROM THE BACKEDGE OF OCEAN EFFECT, PRIMARILY DEPENDENT ON
THE 925MB WIND DIRECTION.

SUNDAY...NO MARINE HEADLINES ANTICIPATED.

&&

.CLIMATE...
THIS MORNINGS RECORDS AND THE NEXT TWO PRIME DAYS FOR RECORDS.
ADDED KACY RER LOW FOR MARCH 1 AT THE END OF THIS SECTION WHERE
RADIATIONAL COOLING MIGHT PERMIT A RECORD SUNDAY MORNING BEFORE
WAA CLOUD COVER CUTS OFF THE COOLING.

ALSO THIS SECTION PROBABLY WONT UPDATE WEDNESDAY BUT WILL UPDATE
AGAIN THURSDAY AND FRIDAY MORNINGS.


POR / SITE / RECORD LOW FEB 24   FEB 27    FEB 28

1872 / KPHL / 2F (1889) NONE     6 1900    9 1934
1874 / KACY / 2F (1889) NONE     7 1934*   2 1934
1894 / KILG / 6F (1923) EQUAL    5 1934   -5 1934
1922 / KABE / 4F (1948) -8RER    -2 1963  -10 1934
1869 / KRDG / 3F (1914) -3RER     4 1934*   3 1934
1865 / KTTN / -2F (1889,1873)NONE 6 1934   1 1934
1948 / KGED / 13F (1956) 11RER   10 1963   8 1950
1901 / KMPO /-14F (1914) -16RER -9 1993 -15 1907

KACY RER FOR 3/1 IS 5 IN 1980.

NOTE: * INDICATE AND OTHER YEARS.
NOTE: POR = PERIOD OF RECORD,THE YEAR OFFICIAL CLIMATE OBS BEGAN.

THE FOLLOWING IS A TABLE OF THE ***PROJECTED*** TOP 5 COLDEST
FEBRUARY`S ON RECORD, BASED ON THE CURRENT FORECAST, AND THUS
SUBJECT TO CHANGE. EACH RANKING DENOTES THE MEAN FEBRUARY
TEMPERATURE /F/ AND YEAR OF OCCURRENCE.

WE REREVIEWED THESE PROJECTIONS LISTED BELOW USING THIS TUESDAY
MORNINGS (24TH) MINS AND THE PHI FCST AS SEEN ON NDFD AND SFT`S.
WE SEE PHL/ABE/ILG ALL VERY CLOSE TO YESTERDAYS PROJECTIONS. KACY
CHANGED TO A WARMER PROJECTION HOWEVER THAT COULD YET REVERT BACK
TO A COLDER MONTHLY AVERAGE DUE TO THE POTENTIAL FOR RADIATIONAL
COOLING ON ONE OR 2 OF THE MORNINGS.

POR  / SITE  / 1ST RANK / 2ND RANK / 3RD RANK / 4TH RANK / 5TH RANK

1872 / KPHL / 22.2(1934) 23.0(1979) 24.3(1885) 24.6(1978) 25.1(2015)
1874 / KACY / 21.6(1979) 23.8(1978/1934) 24.5(2015) 25.5(1875)25.7(1905)
1894 / KILG / 20.2(1934) 22.1(1979) 22.7(1978) 24.2(2015) 24.9(1936)
1922 / KABE / 16.6(1934) 18.5(2015) 20.4(1979) 21.6(1936) 22.0(1963)

PER THE ABOVE TABLE, BOTH ABE IS ON TRACK FOR THE SECOND COLDEST
FEBRUARY, ATLANTIC CITY 3RD COLDEST FOLLOWED BY THE FOURTH
COLDEST AT ILG, AND THE FIFTH COLDEST AT PHL.

THE FOLLOWING IS A TABLE OF THE ***PROJECTED*** MEAN FEBRUARY 2015
TEMPERATURES /F/ AND DEPARTURES FROM NORMAL. THIS IS ALSO BASED ON
THE CURRENT FORECAST, AND THUS SUBJECT TO CHANGE. JANUARY 2015 MEAN
TEMPERATURES ARE ALSO INCLUDED FOR COMPARISON PURPOSES.

POR  / SITE / FEB MEAN(F) / FEB NORMAL(F) / DEPARTURE / JAN MEAN(F)

1872 / KPHL / 25.1        / 35.7          / -10.6     / 30.9
1874 / KACY / 24.5        / 35.3          / -10.8     / 30.2
1894 / KILG / 24.2        / 35.1          / -10.9     / 30.3
1922 / KABE / 18.5        / 30.7          / -12.2     / 25.9

IN GENERAL, MEAN TEMPERATURES AT OUR FOUR MAJOR CLIMATE SITES ARE ON
TRACK TO BE AROUND 10 TO 12 DEGREES BELOW NORMAL FOR FEBRUARY 2015.
IT`S ALSO INTERESTING TO NOTE THAT THE PROJECTED FEBRUARY 2015 MEAN
TEMPERATURES WILL BE WELL BELOW THE JANUARY 2015 MEAN TEMPERATURES.
TO PUT THIS IN PERSPECTIVE, NORMAL MEAN FEBRUARY TEMPERATURES AT OUR
FOUR MAJOR CLIMATE SITES ARE ABOUT 2 TO 3 DEGREES WARMER THAN JANUARY.
THE OPPOSITE IS SHAPING UP FOR FEBRUARY 2015.

ALSO...OF INTEREST...THIS WOULD ALSO BE THE SECOND COLDEST MONTHLY
MEAN TEMPERATURE ON RECORD AT ALLENTOWN SINCE RECORDS BEGAN IN
1922; FEBRUARY 1934 BEING THE COLDEST!

PHL PROJECTS 12TH COLDEST MONTHLY MEAN SINCE RECORDS BEGAN IN 1873.

ATLANTIC CITY 7TH COLDEST MONTHLY MEAN SINCE RECORDS BEGAN THERE
IN 1874.

WILMINGTON HAS MISSING DATA IN ITS DATABASE (1897-1916) AND SO WE
DONT FOCUS AS MUCH ATTENTION ON THAT RECORD.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST WEDNESDAY FOR
     ANZ450-451.

&&

$$
SYNOPSIS...DRAG
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...DRAG
AVIATION...DRAG/ROBERTSON
MARINE...DRAG/ROBERTSON
CLIMATE...CORRECTED MPO LOW THIS MORNING  431