Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 011330
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
930 AM EDT WED APR 1 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION TODAY AND SLOWLY MOVE
OFFSHORE ON THURSDAY. A WARM FRONT WILL MOVE NORTHWARD THROUGH OUR
AREA THURSDAY NIGHT...FOLLOWED BY A STRONG COLD FRONTAL PASSAGE
SATURDAY MORNING. A WEAKER COLD FRONT WILL GRADUALLY MOVE
SOUTHWARD INTO OUR REGION SUNDAY NIGHT...AND MAY STALL OVER THE
MID ATLANTIC THROUGH MID-WEEK...AS WAVES OF LOW PRESSURE MOVE
ALONG IT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SKY OVER THE NORTHERN PART OF OUR FORECAST AREA WAS PARTLY
CLOUDY AT MID MORNING. CONDITIONS WERE CLEAR OVER OUR CENTRAL AND
SOUTHERN COUNTIES. THE PATTERN IS EXPECTED TO CONTINUE THOUGH THE
DAY WITH A BIT MORE CLOUD COVER OVER THE NORTH THAN OVER THE
CENTRAL AND SOUTHERN PARTS OF OUR FORECAST AREA.

TEMPERATURES IN OUR REGION WERE MOSTLY IN THE 30S AROUND 900 AM.
AFTERNOON READINGS SHOULD RISE MAINLY INTO THE UPPER 40S AND LOWER
50S DURING THE AFTERNOON WITH A NORTHWEST WIND AROUND 10 TO 15
MPH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
BECAUSE OF THE UNSEASONABLY COLD FEBRUARY AND MARCH WE ARE
DELAYING THE START OF FROST AND FREEZE PRODUCTS FOR THE DELMARVA
UNTIL APRIL 11TH. EVEN LOCALLY, WE ARE WAY BEHIND. OUR NEIGHBOR`S
BEAUTIFUL WHITE MAGNOLIA TREES THAT NORMALLY BLOOM LIKE CLOCKWORK
ON THE FIRST DAY OF SPRING ARE NOT EVEN CLOSE, ESTIMATING WE ARE
ABOUT TWO WEEKS BEHIND SCHEDULE.

SPEAKING OF FROST WITH THE HIGH PRESSURE SYSTEM PASSING OVER OUR
CWA TONIGHT, EXCELLENT RADIATIONAL COOLING CONDITIONS ARE
EXPECTED. THE GRADIENT STARTS TO TIGHTEN TOWARD MORNING, BUT
SUSPECT THE RADIATIONAL INVERSION WILL PREVENT MIXING. AT THE
NORTH END OF OUR CWA SOME HIGH LEVEL CLOUDS SHOULD ARRIVE TOWARD
MORNING. BECAUSE WE ARE ON THE CONVERGENT SIDE OF THE JET AND
STRONG RIDGING IS PREDICTED OVERNIGHT, DO NOT BELIEVE THEY WILL
HAVE MUCH OF A THERMAL IMPACT. THUS MIN TEMPS IN OUTLYING AREAS
ARE AT OR BELOW STAT GUIDANCE. CLOSER TO STAT GUIDANCE IN URBAN
AND COASTAL AREAS.

THE GFS BRINGS MEASURABLE PCPN EVER SO CLOSE TO NJ TOWARD
MORNING, OVER THE PAST MONTH IN THE 24 TO 36 HR FORECAST TIME
FRAME, ITS EQUITABLE THREAT SCORE IS LOWER AND ITS (WET) BIAS WITH
THE .01 ISOHYET IS HIGHER THAN THE SREF, NAM OR ECMWF IN OUR
REGION. BTW AT 24 HOURS THE ECMWF AND AT 36 HR THE NAM HAS HAD THE
HIGHEST SCORE WITH THAT ISOHYET. THAT BEING SAID, THE GFS KEEPS
PREDICTED OMEGA, THETA E RDGG AND MID LEVEL WAA NORTH OF OUR CWA,
SO NO PCPN CORROBORATION.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE MID-LEVEL PATTERN FEATURES A RIDGE CRESTING OVER THE
NORTHEAST CONUS FRI NIGHT...WITH THE FLOW BACKING
SOUTHWEST...FOLLOWED BY THE PASSAGE OF A STRONG S/WV ON SATURDAY.
THEREAFTER...COMPLEX PATTERN SETS UP AS TROUGH SETS UP OVER THE
WESTERN US AND DOWNSTREAM FLOW BECOMES WEST-SOUTHWEST OVER THE ERN
CONUS. THE 00Z/01 MODEL SUITE DISAGREEMENT CENTERS AROUND
MAGNITUDE OF S/WV ENERGY ENTERING THE WESTERN CONUS TROUGH AND
UPPER MS VALLEY EARLY NEXT WEEK. THE EC/UKMET SOLUTION FAVORS A
MORE ZONAL FLOW OVER THE NORTHEAST CONUS WHICH LEADS TO A
STATIONARY FRONT INVOF THE MID ATLANTIC...WHILE THE GFS SOLUTION
FAVORS MORE OF A MERIDIONAL FLOW WHICH PLACES THIS FRONT FURTHER
TO THE NORTH.

DAY TO DAY...EXPECTING TEMPS ABV AVERAGE ON THU AND FRI W/GUSTY
SOUTHWEST WINDS LIKELY. A GENERALLY DRY DAY EXPECTED THU WITH
SHOWERS AND THUNDERSTORMS LIKELY FRI AS A COLD FRONT APPROACHES
FROM THE WEST. AS THE COLD FRONT CROSSES THE AREA EARLY SAT... IT
WILL TURN BLUSTERY AND PRECIP MAY TURN TO SNOW OVER THE HIGHER
TERRAIN...DEPENDING ON THE THERMAL PROFILE. THIS BEARS WATCHING. A
BRIEF REPRIVE ON SUNDAY BEFORE A STATIONARY BOUNDARY ATTEMPTS TO
SETUP INVOF THE MID ATLANTIC IN THE MON THRU WED TIME FRAME. THIS
FAVORS AN OVERRUNNING REGIME...AND WITH THE ADDITION OF GULF
MOISTURE...HEAVY RAINFALL IS A POSSIBILITY DURING THIS TIME FRAME.

&&

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

NO BIG CHANGES WITH THE 12Z TAFS.

THIS MORNING...VFR. NORTHWEST WINDS SHOULD AVERAGE 10 TO 15 KTS.
WE MIGHT HAVE SOME GUSTINESS, BUT BELIEVE THEY SHOULD BE UNDER 20
KTS AND HAVE NOT CARRIED THEM AT ANY TAF SITE.

THIS AFTERNOON...A VFR CU BASED CIG MIGHT FORM AT NORTHERN AND PA
AIRPORTS AND TERMINALS. ELSEWHERE WE ARE EXPECTING THEM TO BE
SCATTERED OR LESS. WINDS SHOULD BACK EVER SO SLIGHTLY MORE TO THE
WEST WITH SIMILAR SPEEDS. NO CHANGE TO GUSTINESS THINKING.

TONIGHT...LIGHT WINDS, NO VSBY RESTRICTIONS EXPECTED. SOME CIRRUS
CLOUDS WILL PASS BY AFTER MIDNIGHT.

OUTLOOK...
THURSDAY...VFR CONDITIONS EXPECTED.

THURSDAY NIGHT AND FRIDAY...MVFR POSSIBLE IN SHRA AND TSRA.

SATURDAY...MVFR IN SHRA EARLY...GRADUALLY IMPROVING TO VFR.

SUNDAY AND MONDAY...GENERALLY VFR WITH MVFR POSSIBLE IN SHRA.

&&

.MARINE...
THE SMALL CRAFT ADVISORY HAS EXPIRED DUE TO THE COMBINATION OF A
RELAXING GRADIENT AND INCREASING AIR TEMPERATURES.

THEN WITH THE HIGH PRESSURE SYSTEM NEARING OUR AREA, SUB SMALL
CRAFT ADVISORY CONDITIONS WILL CONTINUE THROUGH TONIGHT.

OUTLOOK...
THURSDAY AND FRIDAY...SEAS ARE EXPECTED TO REACH SCA CRITERIA
LATE ON THU AND CONTINUE THRU SATURDAY. MEANWHILE...SOUTHWEST
WINDS ON THU AND FRI ARE ANTICIPATED TO VEER NORTHWEST BY FRI
NIGHT... AND REMAIN AOB THE SCA THRESHOLD DURING THIS TIME FRAME.

SUNDAY AND MONDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW
THE SCA THRESHOLD ATTM.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

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



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