Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 241805
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
105 PM EST SAT JAN 24 2015

.SYNOPSIS...
RAPIDLY INTENSIFYING LOW PRESSURE CROSSING EASTERN NORTH CAROLINA
EARLY TODAY WILL RACE PAST CAPE COD BY THIS EVENING. A WEAK RIDGE
OF HIGH PRESSURE BRIEFLY FOLLOWS SUNDAY. ATTENTION THEN TURNS TO LOW
PRESSURE IN KENTUCKY SUNDAY EVENING. IT MOVES TO THE NORTH CAROLINA
COAST MONDAY THEN INTENSIFIES ALONG ITS TRACK EAST OF NEW ENGLAND
ON TUESDAY. IN ITS WAKE, COLDER AIR IS EXPECTED FOR SEVERAL DAYS
AS HIGH PRESSURE HEADS FOR THE EAST COAST THURSDAY. A REINFORCING
SURGE OF COLD AIR ARRIVES AFTER A COLD FRONTAL PASSAGE FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH THE EARLY AFTERNOON UPDATE, WE HAVE ALLOWED THE REMAINING
WINTER STORM WARNING THAT WAS COVERING PORTIONS OF NORTHWEST NEW
JERSEY AND EASTERN PENNSYLVANIA TO EXPIRE. WHILE SOME SCATTERED
SNOW SHOWERS ARE EXPECTED THIS AFTERNOON WITH THE MID-LEVEL TROUGH
STILL OFF TO THE WEST, LITTLE IF ANY ADDITIONAL ACCUMULATION IS
EXPECTED.

OTHERWISE, WE SHOULD BEGIN TO DRY FROM WEST TO EAST AS THE
SURFACE LOW PRESSURE TO OUR SOUTHEAST RAPIDLY MOVES NORTHEASTWARD
AND CONTINUES TO DEEPEN. COLD AIR WILL FILTER IN BEHIND THE
DEPARTING LOW PRESSURE ALLOWING FOR ANY REMAINING MOISTURE TO TURN
BACK OVER TO SNOW. A FEW SNOW SHOWERS ARE POSSIBLE THIS
AFTERNOON/EVENING WITH MINIMAL ACCUMULATIONS AS BOUNDARY LAYER
TEMPERATURES WILL BE ABOVE FREEZING, MID-30S ACROSS OUR EASTERN
ZONES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
SNOW SHOWERS SHOULD COME TO AN END AS HIGH PRESSURE PRESSES IN FROM
THE WEST, ALBEIT BRIEFLY. SKIES WILL CLEAR WITH BRISK WESTERLY
WINDS. TEMPERATURES ARE EXPECTED TO DIP INTO THE MID TO
UPPER-20S...SLIGHTLY COLDER IN FRESH PACK AREAS.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
500MB: A PAIR OF SHORT WAVES HEADING SOUTHEAST FROM CENTRAL NORTH
AMERICA SUNDAY WILL PROBABLY EVOLVE INTO A STRONG LONG WAVE TROUGH
OVER THE EASTERN SEABOARD STATES ON TUESDAY BEFORE RIDGING FOLLOWS
THURSDAY. A SHORT WAVE PASSAGE THROUGH SOUTHEAST CANADA FRIDAY SEEMS
TO WANT TO YANK THE POLAR VORTEX SOUTHWARD TO NEAR JAMES BAY BY THE
START OF NEXT WEEKEND.

TEMPERATURES: NEAR NORMAL SUNDAY THEN BELOW NORMAL MONDAY THROUGH
THURSDAY WITH POTENTIALLY WELL BELOW NORMAL TEMPS TUESDAY AND
WEDNESDAY.  A BRIEF RETURN TO NEAR NORMAL TEMPS EXPECTED FRIDAY.

FORECAST BASIS: UNLESS OTHERWISE NOTED WITHIN THE DAILIES. THIS
FORECAST IS A 50 50 BLEND OF THE 00Z/24 MAV/MET FOR SUNDAY-MONDAY.
THE 00Z/24 MEX MOS WAS APPLIED MONDAY NIGHT AND TUESDAY.NO CHANGES
WERE MADE TO THE FORECAST BEYOND TUESDAY.

THE DAILIES...

SUNDAY...A QUIET DAY WITH WEAK COLD AIR ADVECTION. INCREASING CLOUDS
AHEAD OF THE CLIPPER HEADING ESE FROM THE LOWER OHIO VALLEY.

SUNDAY NIGHT-MONDAY NIGHT...SNOW OVERSPREADS THE AREA SUNDAY EVENING.
PRECIP COULD BEGIN OVER NRN DELMARVA AS A MIX OF RAIN AND SNOW BUT
SHOULD CHANGE TO ALL SNOW OVERNIGHT AS THE PRECIP RATE INCREASES AND
SOME NOCTURNAL COOLING TAKES PLACE. PERIODS OF SNOW SHOULD CONTINUE
INTO MONDAY AS LOW PRESSURE MOVES BY TO OUR SOUTH AND THEN BEGINS TO
DEEPEN OFF THE MID-ATLANTIC COAST. THE MOST SIGNIFICANT SNOW COULD
OCCUR MONDAY MORNING...ALTO OVERALL AMOUNTS SHOULD BE LIGHT THOUGH
THERE IS OPPORTUNITY FOR THIS STORM TO DEEPEN CLOSER TO THE COAST
ON MONDAY. THIS CERTAINLY PORTENDS TO BECOME AT LEAST AN ADVISORY
SITUATION FOR THE DELMARVA AND COASTAL NEW JERSEY AND NEEDS TO BE
MONITORED FOR MORE SIGNIFICANT POWDERY AMOUNTS OF SNOW. SNOW WATER
RATIOS SHOULD BE MUCH DRIER THAN WHAT OCCURRED LAST NIGHT....IN
OTHER WORDS FLUFFIER.

A POTENTIAL HAZARDOUS MONDAY MORNING COMMUTE IS IN THE OFFING FOR
A PORTION OF OUR FORECAST AREA. GUSTY NORTHERLY WINDS TO 20 TO 25
MPH MAY CAUSE SOME DRIFTING OF THE SNOW ON THE DELMARVA...ESPECIALLY
THE DELAWARE COAST.

WIND CHILLS WILL BE NOTICED!

TIDAL SURGE: FAIRLY LARGE ON MONDAY AND TUESDAY DUE TO NORTHERLY
FLOW WITH SMALL POTENTIAL FOR MINOR COASTAL FLOODING ALONG THE
ATLANTIC SHORES.

TUESDAY-WEDNESDAY...HIGH PRES AND DRIER AIR WILL GRADUALLY MOVE IN
FOR MID WEEK ON CONTINUED NORTHERLY FLOW WITH GUSTS TO 20 MPH
DURING THE DAYLIGHT HOURS.  .

THURSDAY...WAA CLOUDS AND POSSIBLE SNOW SHOWERS LATE THURSDAY AHEAD
OF THE NEXT SHORT WAVE...THIS ONE IN CANADA WITH A STRONG COLD FRONT
TO FOLLOW FRIDAY.

FRIDAY...CAA DEVELOPS BEHIND THE CFP.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

LOW LEVEL MOISTURE WILL REMAIN IN OUR REGION THROUGH THE BALANCE OF
THE AFTERNOON. A DISTURBANCE IN THE UPPER ATMOSPHERE IS EXPECTED TO
PASS FROM WEST TO EAST ACROSS OUR REGION AND IT SHOULD BE
ACCOMPANIED BY SOME SHOWER ACTIVITY. THE SHOWERS ARE FORECAST TO BE
ALL SNOW AT KRDG, KABE AND KTTN AND A MIX OF RAIN AND SNOW AT OUR
REMAINING TAF SITES. IT APPEARS AS THOUGH VISIBILITY VALUES WILL BE
REDUCED TO AROUND 1 MILE AT TIMES. LITTLE OR NO ADDITIONAL SNOW
ACCUMULATION IS EXPECTED.

DRYING WILL BEGIN TO WORK ITS WAY INTO OUR REGION FROM THE WEST THIS
EVENING AS THE UPPER LEVEL DISTURBANCE PASSES FARTHER OFF THE COAST.
WE ARE ANTICIPATING AN IMPROVEMENT THROUGH MVFR TO VFR BETWEEN ABOUT
2200Z AND 0100Z.

WE EXPECT MAINLY VFR CONDITIONS FROM ABOUT 0100Z UNTIL THE END OF
THE TAF PERIOD. WE HAVE INDICATED A CEILING AROUND 4000 FEET THROUGH
MUCH OF THE NIGHT AND INTO SUNDAY MORNING. WE MAY BE A LITTLE
PESSIMISTIC AS THE CLOUDS COULD FAVOR SCATTERED FOR AT LEAST PART OF
THE TIME.

A NORTHWEST WIND AROUND 8 TO 10 KNOTS IS EXPECTED TO GUST TO AROUND
20 KNOTS THROUGH THIS EVENING. THE WIND GUSTS ARE FORECAST TO
DIMINISH LATE TONIGHT AND WIND SPEEDS SHOULD REMAIN IN THE 6 TO 10
KNOTS RANGE INTO SUNDAY.

OUTLOOK...
SUN NIGHT...CONDITIONS DIMINISHING WITH IFR POSSIBLE AND SNOW BY
EARLY MONDAY MORNING....ESPECIALLY KTTN SOUTHWARD. CONFIDENCE:
ABOVE AVERAGE

MON...MVFR/IFR WITH LOWER CIGS/VSBYS IN SNOW...ESPECIALLY KILG AND
KMIV.  CONFIDENCE: ABOVE AVERAGE.

MON NIGHT - CONDITIONS SLOWLY IMPROVING TO MVFR...POSSIBLY VFR LATE.
CONFIDENCE: AVERAGE SINCE THE DEVELOPING STORM MAY FORCE SNOW TO
LINGER ALONG THE COAST.

TUE - WED...MOSTLY VFR.  CONFIDENCE: ABOVE AVERAGE.

&&

.MARINE...
TODAY - TONIGHT...CONTINUED SCA CONDITIONS EVERYWHERE AS COASTAL
LOW PRESSURE RAPIDLY DEEPENS TODAY AND RACES OFF TOWARDS THE
NORTHEAST. NORTHEAST WINDS SHIFT TOWARDS THE WEST-NORTHWEST LATER
TODAY BEHIND THE DEPARTING LOW PRESSURE.

OUTLOOK...
STRONG SMALL CRAFT ADVISORY CONDS ARE EXPECTED TO DEVELOP EARLY
MONDAY MORNING AND MAY CONTINUE THROUGH WEDNESDAY. POTENTIAL GALES
MONDAY AND MONDAY NIGHT DELAWARE COAST. SEAS COULD EASILY BUILD TO
12 FEET EAST OF CAPE MAY TO EAST OF DELAWARE IN PERSISTENT NNE FLOW.
LIGHT TO POSSIBLY MODERATE FREEZING SPRAY POTENTIAL MONDAY NIGHT AND
WEDNESDAY NIGHT.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ430-431.

&&

$$
SYNOPSIS...DRAG
NEAR TERM...HEAVENER/KLINE
SHORT TERM...HEAVENER
LONG TERM...DRAG/HEAVENER
AVIATION...DRAG/IOVINO
MARINE...DRAG/HEAVENER





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