000
FXUS61 KPHI 251515
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1015 AM EST WED FEB 25 2015

.SYNOPSIS...
LOW PRESSURE OFF OF THE NORTH CAROLINA COAST WILL TRACK
NORTHEASTWARD AND OUT TO SEA TODAY, THEN A COLD FRONT WILL MOVE
ACROSS OUR AREA LATER TODAY. A MORE POTENT LOW PRESSURE SYSTEM
ALONG THE GULF COAST TRACKS NORTHEASTWARD, WHICH THEN 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 WILL CROSS OUR AREA SUNDAY
NIGHT OR MONDAY. A STRONGER LOW PRESSURE SYSTEM WILL APPROACH FROM
THE SOUTHWEST ON TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH THE COASTAL LOW AND THE NORTHERN LOW RAPIDLY LIFTING AWAY
FROM THE REGION, WE SHOULD SEE RATHER TRANQUIL WEATHER THROUGH
THE DAY TIME HOURS. STILL LOOKING AT A VERY WEAK COLD FRONT MOVING
IN FOLLOWED BY AN INVERTED SURFACE RIDGE SETTLING IN LATE IN THE
DAY.

TEMPERATURES SHOULD BE ABOUT 10 DEGREES HIGHER THAN YESTERDAY,
BUT WITH BREEZY CONDITIONS, IT WON`T FEEL THAT WAY. HIGH
TEMPERATURES WILL BE INTO THE 30S THROUGH MUCH OF THE REGION.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE NEXT IN THE PARADE OF LOWS LIFTS NE ALONG THE CAROLINA COAST
THROUGH THE EVENING HOURS. THOUGH THE CENTER OF THE LOW SHOULD BE
WELL OUT TO SEA, A TRAILING UPPER LEVEL SHORT WAVE TROUGH CROSSING
OVER THE SOUTHERN HALF OF OUR REGION COULD LEAD TO LIGHT SNOW
ESPECIALLY ACROSS DELMARVA AND ACROSS FAR SOUTHERN NJ.

DESPITE WHAT THE CALENDAR SAYS, MODEL SOUNDINGS REMAIN PLENTY COLD
ENOUGH FOR ALL SNOW FOR THE P TYPE. AS FOR SNOW AMOUNTS, HAVE STAYED
CLOSE TO THE PREVIOUS FORECAST AND WPC GUIDANCE.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
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.

THURSDAY...WE HAVE ISSUED A WINTER WEATHER ADVISORY FOR A LIGHT SNOW
ACCUMULATION ACROSS THE EXTREME SOUTHERN DELMARVA THROUGH THE
MORNING HOURS ON THURSDAY. MID-LEVEL CONSENSUS SHOWS A VERY BROAD
TROUGH OVER THE REGION WITH A WEAK SOUTHERN STREAM IMPULSE SLIDING
THROUGH FROM THE SOUTHWEST. AS THE WAVE MOVES TOWARDS THE EAST-
NORTHEAST IT PICKS UP SPEED, WITHOUT MUCH DOWNSTREAM BLOCKING
PRESENT, AND OPENS UP EVEN FURTHER ACTING MORE LIKE A STABLE WAVE
THOUGH IT DOES TURN SLIGHTLY NEGATIVE. AT THE SURFACE THE CENTER OF
THE LOW SHOULD REMAIN WELL TO THE SOUTH OF OUR REGION PLACING THE
SOUTHERN HALF OF OUR CWA IN ITS NORTHERN FRINGE PRECIPITATION
SHIELD. SOME UPPER LEVEL DYNAMICS, IN THE FORM OF A POSSIBLE
COUPLED JET STREAK STRUCTURE, HAS OUR SOUTHERN ZONES WITHIN AN
AREA OF BROAD SCALE LIFT. THERMALLY WE ARE COLD ENOUGH FOR ALL
SNOW BUT DO NOT SEE MUCH IN THE WAY OF THERMALLY DRIVEN
ENHANCEMENT, BANDING, TO HELP INCREASE OUR ACCUMULATIONS. AS WAS
STATED ABOVE IN THE NEAR TERM SECTION WE STAYED CLOSE TO A WPC
SNOWFALL FORECAST FOR THIS EVENT...GENERALLY A 1 TO 2 INCH EVENT
WITH SOME HIGHER TOTALS POSSIBLE IN THE ADVISED AREA. IT SHOULD BE
NOTED THOUGH, OUR CURRENT 90TH PERCENTILE GRAPHIC SHOWS UPWARDS OF
6 TO 8 INCHES OF SNOW POSSIBLE WITH THIS SYSTEM ACROSS THE
DELMARVA. RECENT RUNS OF THE SREF, MOSTLY ITS ARW MEMBERS, HAVE
GONE GANG BUSTERS WITH THE AMOUNT OF QPF, GIVEN THEIR MESOSCALE
CORE WHICH COMPLETELY SKEWS THE TOTALS. USE THE SREF VERY VERY
VERY CAREFULLY, OR NOT AT ALL.

ELSEWHERE, NOT EXPECTING MUCH QPF TO MAKE IT FAR ENOUGH NORTH TO BE
AN ISSUE. THE COLUMN REMAINS FAIRLY DRY NORTH OF THE DELMARVA AND AS
THE NORTHERN STREAM MID-LEVEL TROUGH SWINGS THROUGH WE COULD SEE
SOME ISOLATED TO SCATTERED SNOW SHOWERS, THOUGH THEY APPEAR TO BE
PRETTY LIGHT, MOSTLY FLURRIES, WITH VERY LITTLE TO NO ACCUMULATION
EXPECTED.

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 WEST-SOUTHWESTERLY FLOW COMMENCES AS
SURFACE RIDGING DEPARTS THE COAST. TEMPERATURES BEGIN TO CLIMB
CLOSER TO NORMAL. 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.

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 /15Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS SHOULD CONTINUE THROUGH AT LEAST 06Z. VERY LATE
TONIGHT (AFTER 06Z, BUT LIKELY CLOSER TO 09Z), SNOW SHOULD BEGIN TO
MOVE INTO SOUTHEASTERN PORTIONS OF THE REGION. AT THIS TIME, KPHL,
KPNE, KILG, KMIV, AND KRDG HAVE A LOW CHANCE OF SEEING SNOW
OVERNIGHT, WHILE KACY HAS THE HIGHEST CHANCE. EXPECT CEILINGS TO
LOWER AFTER 06Z, THOUGH WILL LIKELY REMAIN IN THE VFR CATEGORY. AND
WITH ANY SNOW, EXPECT TO SEE MVFR VISIBILITIES.

OUTLOOK...
THURSDAY...MOSTLY VFR. STEADY MVFR/IFR SNOW AROUND
MIV/ACY THURSDAY MORNING. ISOLATED TO SCATTERED SNOW SHOWERS
POSSIBLE THURSDAY AFTERNOON.

FRIDAY - SATURDAY...VFR.

SUNDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE DAY AS THE
NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST.

&&

.MARINE...
WESTERLY WINDS WILL INCREASE AFTER DAYBREAK. BY MID DAY, GUSTS NEAR
25KT WILL BE POSSIBLE ON THE NORTHERN NEW JERSEY COASTAL WATERS.
WITH THE INCREASING WINDS, SEAS SHOULD ALSO INCREASE, ESPECIALLY ON
THE NORTHERN NEW JERSEY COASTAL WATERS. ELSEWHERE, WINDS AND SEAS
SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY AND THIS EVENING.

AFTER MIDNIGHT, COULD SEE WINDS INCREASE AGAIN, WITH GUSTS ABOVE
20KT POSSIBLE ON THE ATLANTIC COASTAL WATERS.

OUTLOOK...
THURSDAY... 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.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
     THURSDAY FOR DEZ003-004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450-
     451.

&&

$$
SYNOPSIS...DRAG/GORSE
NEAR TERM...JOHNSON/MEOLA
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON