Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 241326
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
826 AM EST TUE FEB 24 2015

.SYNOPSIS...
ARCTIC HIGH PRESSURE WILL CONTINUE TO CROSS THE REGION TODAY
BEFORE SHIFTING OFFSHORE THIS EVENING. LOW PRESSURE FORMS OFF THE
SOUTHERN MID ATLANTIC COAST TUESDAY NIGHT AND THEN SCOOTS
NORTHEASTWARD. A COLD FRONT WILL PASS ACROSS OUR AREA WEDNESDAY,
THEN A MORE POTENT LOW PRESSURE SYSTEM ALONG THE GULF COAST
WEDNESDAY EVENING RACES OUT TO SEA WELL TO OUR EAST ON THURSDAY.
STRONG ARCTIC HIGH PRESSURE CENTERED IN MONTANA WILL ARRIVE ALONG
THE MID ATLANTIC COAST NEXT WEEKEND, THEN A COLD FRONT APPROACHES
FROM THE WEST NEXT MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LIGHT WINDS WILL BEGIN TO SHIFT FROM NORTHERLY TO SOUTHEASTERLY AS A
SURFACE HIGH SLIDES NE OF THE REGION BY MID DAY. UNFORTUNATELY, AS
LIGHT AS THE WINDS ARE, THE SOUTHERLY FLOW WON/T BE MUCH HELP FOR
GETTING TEMPERATURES BACK TO NEAR NORMAL. HIGHS TODAY WILL CONTINUE
TO BE WELL BELOW NORMAL, WITH THE ENTIRE REGION EXPECTED TO STAY
BELOW FREEZING, AND MUCH OF THE NORTHERN HALF OF THE REGION
STRUGGLING TO GET OUT OF THE TEENS. WENT WITH OR JUST BELOW GUIDANCE
TO ACCOUNT FOR THE PERSISTENT SNOW PACK OVER MUCH OF THE REGION.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TWO LOWS TO WATCH TONIGHT. FIRST, A COASTAL LOW IS EXPECTED TO
DEVELOP OFF THE CAROLINA COAST AND LIFT NE. MODELS TRENDED
SLIGHTLY FURTHER WEST WITH THE TRACK. AS SUCH, COASTAL DE AND NJ
COULD BE ON THE WESTERN FRINGE OF ANY ASSOCIATED PRECIPITATION.

THE SECOND LOW TO WATCH WILL BE CROSSING THE NORTHERN GREAT LAKES
REGION. IN THIS CASE, THE POCONO`S COULD BE ON THE SOUTHERN
FRINGE OF ANY ASSOCIATED PRECIPITATION. HOWEVER, MODELS ARE IN
RELATIVELY GOOD AGREEMENT OF THE VORT MAX PASSING NORTH OF THE
REGION.

DESPITE THE REGION BEING IN BETWEEN THE TWO LOWS, WINDS SHOULD NOT
BE MUCH HIGHER THAN DURING DAY AS THE PRESSURE GRADIENT ACROSS THE
REGION ISN/T EXPECTED TO INCREASE DRAMATICALLY UNTIL AFTER MIDNIGHT
TONIGHT.

AS WITH THE HIGHS, GENERALLY UNDERCUT GUIDANCE ON LOWS TONIGHT TO
ACCOUNT FOR THE SNOW PACK.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
VERY BROAD TROUGHING ACROSS THE EASTERN HALF OF THE STATES THROUGH
THE FIRST PART OF THE EXTENDED FOLLOWED BY ZONAL FLOW/WEAK RIDGING
TOWARDS THE WEEKEND. A RETURN TO BROAD SCALE TROUGHING IS EXPECTED
AGAIN VERY LATE IN THE PERIOD.

WEDNESDAY - THURSDAY... SHOULD BE MOSTLY DRY ON WEDNESDAY WITH AS
ONE EMBEDDED MID-LEVEL SHORTWAVE MOVES FARTHER TO OUR NORTHEAST
EARLY IN THE DAY. WE ARE WATCHING THE ADVANCEMENT OF ANOTHER SYSTEM,
THIS TIME A SOUTHERN STREAM EMBEDDED WAVE THAT FORMS A WEAK LOW
PRESSURE OFF THE SOUTHEAST COAST. MODEL CONSENSUS THE PAST FEW DAYS
HAS BEEN TO KEEP THIS SYSTEM FAIRLY SUPPRESSED AS IT EJECTS OUT TO
SEA, BUT THAT DOES NOT MEAN WE STAY COMPLETELY DRY EITHER. LATE
WEDNESDAY NIGHT LIGHT PRECIPITATION, SNOW, SHOULD CLIP THE
SOUTHEASTERN PORTION OF THE DELMARVA AND POSSIBLY EXTREME
SOUTHEASTERN NEW JERSEY AS IT MOVES BY. UPPER LEVEL JET STREAK
DYNAMICS WILL HELP AIDE IN SLIGHTLY WETTER CONDITIONS ACROSS
SOUTHERN DELMARVA WITH A LIGHT ACCUMULATION OF SNOW POSSIBLE...WE
KEEP TOTALS BELOW AN INCH AT THIS TIME BASED ON THE LOWS TRACK. THE
SURFACE WAVE QUICKLY MOVES OUT TO SEA WITH LITTLE DOWNSTREAM
BLOCKING IN PLACE AND WE DRY OUT BY THE AFTERNOON HOURS.
TEMPERATURES ON WEDNESDAY LOOK TO GET ABOVE FREEZING BEFORE FALLING
ONCE AGAIN ON THURSDAY BEHIND THE DEPARTING LOW PRESSURE AND THE
PREVIOUS DAYS COLD FRONT PASSAGE.

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...WE END METEOROLOGICAL WINTER
WITH ANOTHER CLOD SNAP.

SUNDAY - MONDAY...ZONAL FLOW TURNS SHARPER AS THE BROAD TROUGH
RELOADS TO OUR WEST. DEEP SOUTHWESTERLY FLOW COMMENCES AS SURFACE
RIDGING DEPARTS THE COAST. TEMPERATURES BEGIN TO CLIMB CLOSER TO
NORMAL, POSSIBLY ABOVE NORMAL FOR THE FIRST TIME IN A WHILE BY
MONDAY. SOUTHERN STREAM SYSTEM WITH LOTS OF MOISTURE IS EXPECTED TO
PASS THROUGH THE REGION DURING THIS PERIOD AND DEPENDING ON WHEN IT
STARTS TO AFFECT THE AREA MIXED-PHASE PRECIPITATION WILL OCCUR. TOO
EARLY FOR SPECIFICS THIS FAR OUT BUT A SNOW TO RAIN PROGRESSION
LOOKS GOOD.

&&

.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS ARE EXPECTED THROUGH 00Z. WINDS WILL BE LIGHT THROUGH
THE DAY AND COULD AT TIMES BE VRB AS THEY SHIFT FROM NORTHERLY TO
SOUTHEASTERLY THROUGH THE DAY. AFTER 00Z, MODELS ARE SHOWING A LAYER
AROUND 1000 TO 3000 FT AGL BECOMING NEARLY SATURATED ACROSS MUCH OF
THE REGION. GIVEN HOW WEAK THE WINDS ARE, IT SEEMS UNLIKELY AT THIS
TIME THAT THIS WILL MEAN PERSISTENT CEILINGS AT THAT LEVEL, BUT HAVE
INCLUDED A SCT MENTION AND WILL CONTINUE TO MONITOR THROUGH THE DAY.
OTHER THAN THAT POSSIBILITY, VFR CONDITIONS SHOULD CONTINUE
OVERNIGHT.

OUTLOOK...

WEDNESDAY...VFR. GUSTY W WINDS POSSIBLE IN THE AFTERNOON.

THURSDAY...MOSTLY VFR. POSSIBLE LIGHT MVFR/IFR SNOW SOUTH AND EAST
OF PHL/ILG...COULD AFFECT MIV/ACY LATE THURSDAY MORNING BEFORE
MOVING OUT TO SEA.

FRIDAY - SATURDAY...VFR.

&&

.MARINE...
WINDS AND SEAS HAVE SUBSIDED, SO WILL LET THE SCA GO AT THE TOP OF
THE HOUR. WITH WINDS DIMINISHING, FREEZING SPRAY WILL SLOWLY
DIMINISH THROUGH THE MORNING HOURS ON THE BAY.

SUB SCA CONDITIONS SHOULD CONTINUE TODAY INTO TONIGHT. HOWEVER,
WINDS INCREASE AFTER MIDNIGHT WITH GUSTS ABOVE 20KT EXPECTED.
HOWEVER CONDITIONS ARE EXPECTED TO REMAIN JUST BELOW SCA CRITERIA.

OUTLOOK...

WEDNESDAY...SUB-SCA EXPECTED, THOUGH VERY MARGINAL SCA GUSTS MAY
OCCUR ACROSS OUR NORTHERN ZONES.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT... WINDS TURN NLY AND
INCREASE TO AROUND 20 KT WITH NEAR SCA LEVELS. MODERATE FREEZING
SPRAY IS ALSO POSSIBLE AS WINDS AND WAVES INCREASE THURSDAY INTO
FRIDAY.

FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT NORTHEAST
WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN ZONES.

&&

.CLIMATE...
THIS MORNINGS RECORDS AND THE NEXT TWO PRIME DAYS FOR RECORDS.

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) -15RER  -9 1993  -15 1907

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...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ054-
     055.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...FREEZING SPRAY ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     ANZ430-431.

&&

$$
SYNOPSIS...HEAVENER
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
CLIMATE...FRANCK/DRAG 827



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