Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 260942
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
542 AM EDT THU MAR 26 2015

.SYNOPSIS...
LOW PRESSURE IN SOUTHERN OHIO WILL MOVE NORTHEASTWARD TODAY. ITS
ASSOCIATED WARM FRONT WILL MOVE THROUGH THE REGION DURING THE
FIRST PART OF THE DAY. THEN AS THE LOW CONTINUES TOWARD NEW
ENGLAND, ITS ATTENDANT COLD FRONT WILL MOVE ACROSS THE MID
ATLANTIC STATES TONIGHT. LOW PRESSURE MAY DEVELOP ON THAT FRONT
OFF THE MID ATLANTIC COAST LATE FRIDAY AND HEAD NORTHEAST WELL OUT
TO SEA SATURDAY. UNSEASONABLY STRONG CANADIAN HIGH PRESSURE BUILD
INTO THE REGION FOR THE WEEKEND. AN AREA OF LOW PRESSURE IS
EXPECTED TO TRACK TO OUR NORTH MONDAY, PULLING A COLD FRONT ACROSS
THE AREA. MORE HIGH PRESSURE IS EXPECTED BEHIND THAT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE WAS SOME CLEARING OF THE LOW CLOUDS OVER EASTERN
PENNSYLVANIA, NORTHEASTERN MARYLAND AND DELAWARE AROUND 530 AM.
HOWEVER, THE LOW CLOUDS ARE EXPECTED TO EXPAND WESTWARD THIS
MORNING AND CEILING HEIGHTS SHOULD LOWER AS ADDITIONAL MOISTURE IS
DRAWN INTO OUR AREA ON THE SOUTHERLY FLOW. ALSO, MILD AIR WILL
CONTINUE TO BUILD OVERHEAD STRENGTHENING THE TEMPERATURE INVERSION
INTO THE MORNING HOURS. WE EXPECT SOME FOG TO DEVELOP IN THE
TERRAIN OF EASTERN PENNSYLVANIA AND NORTHERN NEW JERSEY.THERE WAS
ALREADY A FAIR AMOUNT OF FOG NEAR THE COAST AND OVER OUR COASTAL
WATERS AND IT SHOULD PERSIST THROUGH MUCH OF THE MORNING.

DEVELOPING RAIN SHOWERS OVER THE CHESAPEAKE BAY REGION AND THE
CAROLINAS EARLY THIS MORNING WILL PROGRESS NORTHWARD AND THEY ARE
FORECAST TO AFFECT OUR REGION FROM THIS MORNING INTO THE EARLY
AFTERNOON HOURS. SOME SHOWERS WERE ALREADY INTO SOUTHERN AND
CENTRAL DELAWARE AROUND 530 AM. THE BULK OF THE PRECIPITATION
SHOULD PASS OVER THE COASTAL PLAIN AND OVER OUR COASTAL WATERS.
DEVELOPING LIFT AND SUBTLE INSTABILITY MAY RESULT IN ISOLATED
THUNDER WITHIN THE AREA OF SHOWERS.

THE PROBABILITY OF RAIN SHOWERS MAY DECREASE FOR A TIME THIS
AFTERNOON AFTER A WARM FRONT LIFTS THROUGH MUCH OF OUR REGION.
THERE REMAINS SOME QUESTION AS TO WHETHER THE LOW LEVEL COOL AIR
WILL SCOUR OUT OF OUR NORTHERN COUNTIES ENTIRELY. AS A RESULT,
TODAY`S MAXIMUM TEMPERATURE FORECAST IS ONE OF LOW CONFIDENCE,
ESPECIALLY IN THE NORTH. MEANWHILE, A STRENGTHENING LOW LEVEL JET
WILL BE LOCATED OFF THE COASTS OF THE MIDDLE ATLANTIC STATES AND
SOUTHERN NEW ENGLAND. THE LOW CLOUDS WILL LIKELY CLEAR FROM THE
COASTAL PLAIN DUE TO FRICTIONAL EFFECTS FROM THE JET ALONG WITH
THE STRONG LATE MARCH SUN. MAXIMUM TEMPERATURES AROUND 70 ARE
ANTICIPATED FOR PARTS OF THE UPPER DELMARVA AND EXTREME SOUTHERN
NEW JERSEY.

THE WIND IS FORECAST START AS LIGHT AND VARIABLE AND IT SHOULD
BECOME SOUTHERLY IN THE WAKE OF THE WARM FRONT AS THE BOUNDARY
LIFTS GRADUALLY THROUGH OUR REGION TODAY. WE HAVE INDICATED A
PERIOD OF LIGHT EASTERLY WINDS AHEAD OF THE WARM FRONT.

RAINFALL TOTALS TODAY SHOULD BE LESS THAN A TENTH OF AN INCH IN
MUCH OF OUR REGION. THE CONVECTIVE ACTIVITY DURING THE MORNING AND
EARLY AFTERNOON COULD BRING LOCALIZED RAINFALL TOTALS OF A QUARTER
TO A HALF INCH TO PARTS OF THE UPPER DELMARVA AND SOUTHERN NEW
JERSEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
A COLD FRONT IS FORECAST TO WORK ITS WAY ACROSS OUR REGION FROM
NORTHWEST TO SOUTHEAST BETWEEN ABOUT 800 PM AND 200 AM. SHOWERS
ARE EXPECTED WITH AND BEHIND THE BOUNDARY. INSTABILITY SHOULD BE
RATHER LIMITED. HOWEVER, IT IS A ROBUST FRONTAL BOUNDARY AND
SCATTERED THUNDER REMAINS POSSIBLE.

STRONG COLD ADVECTION WILL TAKE PLACE FOLLOWING THE FRONTAL
PASSAGE AND TEMPERATURES SHOULD FALL INTO THE 40S BY DAYBREAK ON
FRIDAY. READINGS ARE EXPECTED TO DROP INTO THE 30S IN OUR NORTHERN
COUNTIES AND ANY LINGERING RAIN SHOWERS COULD CHANGE TO SNOW
THERE. HOWEVER, ANY SNOWFALL ACCUMULATIONS SHOULD BE NEGLIGIBLE AS
PRECIPITATION RATES CONTINUE TO DIMINISH LATE TONIGHT.

RAINFALL TOTALS WITH THE FRONTAL SYSTEM ARE FORECAST TO BE
GENERALLY A QUARTER INCH OR LESS.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE COLD FRONT WILL BE OFF THE COAST FRI MRNG AND PRECIP WILL BE
COMING TO AN END FROM W TO E DURG THE COURSE OF THE MRNG HOURS.
PRECIP WILL LINGER LONGEST OVER SRN AND ERN SECTIONS WHERE IT CUD
LINGER INTO ERLY AFTN. THE MDLS HAVE COME INTO BETTER AGREEMENT
WITH THIS SCENARIO TODAY, AND MOST IF NOT ALL OF THE PRECIP SHUD
BE OVER WITH BY 00Z SAT WITH EXCEPT FOR PSBLY THE DELMARVA.

LOW PRES IS THEN EXPECTED TO FORM ON THE CDFNT TO THE E FRI NIGHT
INTO SAT AS STRONG HIGH PRES BUILDS DOWN FROM CAN ACRS THE UPPER
MIDWEST. A WEAK SFC TROF MAY DEVELOP ON THE WRN SIDE OF THE TROF
AND MOVE ACRS THE REGION BEFORE THE HIGH BUILDS IN AND THIS TROF
COUPLED WITH AN UNSEASONABLY DEEP H5 TROF COULD TRIGGER SOME
INSTABILITY SHWRS/SNOW SHOWERS ON SAT, ESPECIALLY ACRS THE N. SO,
WILL CARRY SOME LOW POPS.

THE LARGE HIGH THEN MOVE OVER THE AREA SAT NIGHT INTO SUN AND
CONDS DRY OUT. THE HIGH THEN MOVES OFF THE COAST SUN NIGHT AS LOW
PRES TREKS ACRS SRN CANADA. THIS LOW WILL BRING A WK CDFNT ACRS
NEW ENG AND ITS SRN EXTENT MAY BRUSH OUR NRN ZONES. THE FRONT WILL
NOT HAVE MUCH MOISTURE WITH IT, BUT CUD TRIGGER SOME PRECIP WITH
IT MON INTO MON NIGHT.

THEN, THERE IS SOME DISAGREEMENT BETWEEN THE GFS AND ECMWF WITH
REGARD TO TUE. THE GFS KEEPS THINGS DRY WITH WK HIGH PRES. THIS
CONTINUES INTO ERLY WED BEFORE LOW PRES APPROACHES. ON THE OTHER
HAND, THE ECMWF WANTS TO BRING A WK AREA OF LOW PRES ACRS THE
REGION LATER TUE INTO TUE NIGHT THEN KEEPS WED DRY. THE CMC IS
SOMEWHERE IN THE MIDDLE. SO, FOR RIGHT NOW, WILL MAINTAIN A DRY
FCST TUE AND KEEP LOW POPS ON WED AND SEE HOW THINGS DEVELOP.

TEMPS WILL START OFF AROUND NRML ON FRI THEN PLUMMET BEHIND THE
CFP FOR SAT AND SUN. TEMPS WILL AVERAGE 10 TO 15 DEGREES BELOW
NRML OVER THE WEEKEND BEFORE RETURNING TO NR NRML ON MON. THEY
WILL DROP A BIT FOR TUE BEHIND THE WK FRONT THEN BOUNCE BACK AGAIN
NR MIDWEEK.

&&

.AVIATION /10Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

WE WILL KEEP THE MENTION OF LOW LEVEL WIND SHEAR FOR KMIV AND
KACY THIS MORNING DUE TO THE LOW LEVEL SOUTHWESTERLY WIND JET
LOCATED NEAR THE COAST.

CONDITIONS WERE IFR AT KTTN, KPNE AND KACY AROUND 0930Z AND THEY
WERE GENERALLY MVFR AT OUR REMAINING FIVE TAF SITES. CONDITIONS
ARE EXPECTED TO LOWER INTO THE IFR CATEGORY THIS MORNING AT KPHL,
KILG, KMIV, KRDG AND KABE WITH AN AREA OF SHOWERS LIFTING
NORTHWARD AND AFFECTING MAINLY KPHL AND POINTS TO THE SOUTH AND
EAST. ISOLATED THUNDER IS POSSIBLE BUT THE PROBABILITY IS NOT
GREAT ENOUGH TO INCLUDE IN THE TAFS.

SOME IMPROVEMENT INTO THE MVFR CATEGORY IS ANTICIPATED FOR THIS
AFTERNOON AS A WARM FRONT CONTINUES TO LIFT THROUGH OUR REGION.

A COLD FRONT FROM THE NORTHWEST IS FORECAST TO PASS ACROSS OUR
TAF SITES BETWEEN ABOUT 0100Z AND 0500Z. IT WILL BRING ADDITIONAL
SHOWERS AND LOW CONDITIONS. AGAIN, THERE IS A LOW CHANCE OF
THUNDER AT THAT TIME BUT IT IS NOT MENTIONED IN THE TAFS.

CONDITIONS SHOULD REMAIN MVFR FOR LATE TONIGHT AS THE RAIN SHOWER
ACTIVITY BEGINS TO DIMINISH.

A LIGHT AND VARIABLE WIND THIS MORNING MAY BEGIN TO FAVOR THE
EAST AROUND 4 TO 6 KNOTS IN ADVANCE OF THE WARM FRONT. THE WIND
SHOULD BECOME SOUTHERLY AFTER THE FRONT PASSES AND IT IS EXPECTED
TO INCREASE TO AROUND 10 TO 14 KNOTS WITH GUSTS INTO THE 20S. THE
WIND IS ANTICIPATED TO DECREASE A BIT THIS EVENING THEN IT WILL
SHIFT TO THE NORTHWEST FOLLOWING THE PASSAGE OF THE COLD FRONT.

OUTLOOK...
FRI-FRI NIGHT...MOSTLY VFR EXPECTED. SCATTERED SHWR PSBL WITH LWR
CONDS MAINLY E ERLY. MDT TO HIGH CONFIDENCE.

SAT-SAT NIGHT...MOSTLY VFR EXPECTED. SCATTERED SHRA OR SHSN N
PSBL. HIGH CONFIDENCE.

SUNDAY...VFR. HIGH PRESSURE. HIGH CONFIDENCE.

SUNDAY NIGHT-MONDAY...MOSTLY VFR. ISOLATED SHRA/SHSN MAINLY N AND
W PSBL. HIGH CONFIDENCE.

&&

.MARINE...
A STRENGTHENING LOW LEVEL JET IS FORECAST TO REMAIN OVER OUR
COASTAL WATERS TODAY BEFORE IT DRIFTS OUT TO SEA TONIGHT. HOWEVER,
BEING THAT THE WATER TEMPERATURE REMAINS QUITE COLD AND THE AIR
ADVECTING NORTHEASTWARD WITH THE LOW LEVEL JET IS RATHER MILD,
MOMENTUM TRANSFER WILL BE LIMITED. WE ARE ANTICIPATING THAT GUSTS
MAY REACH ONLY 25 OR 30 KNOTS EVEN AS THE LOW LEVEL JET SPEEDS
INCREASE TO 50 OR 60 KNOTS TODAY.

A SURFACE WARM FRONT WILL LIFT ACROSS THE COASTAL WATERS OF NEW
JERSEY AND DELAWARE THIS MORNING. AREAS OF FOG WILL PERSIST UNTIL
THE BOUNDARY ARRIVES. THE VISIBILITY WILL BE A HALF MILE OR LESS
OVER THE WATER.

A COLD FRONT FROM THE NORTHWEST WILL ARRIVE TONIGHT.

WE WILL KEEP THE SMALL CRAFT ADVISORY IN PLACE FOR WIND GUSTS
AROUND 25 KNOTS AND FOR WAVE HEIGHTS ON OUR OCEAN WATERS BUILDING
TO 5 TO 8 FEET.

OUTLOOK...
FRI...SCA CONDS REMAIN ON THE OCEAN DUE TO ELEVATED SEAS.

FRI NIGHT THRU SAT NIGHT...WIND AND SEAS MAY ONCE AGAIN APPROACH
SCA CONDS ON STRONG NWLY FLOW. CONDS APPEAR MARGINAL, BUT
ADDITIONAL FLAGS MAY BE NEEDED FOR A PORTION OF THIS TIME FRAME.

SUN...NO MARINE HEADLINES ANTICIPATED AS CONDS DECREASE TO BELOW
SCA CONDS.

SUN NIGHT-MON...WINDS AND SEAS INCREASE OVERNIGHT TO AT LEAST
SMALL CRAFT ADVISORY LEVELS, POSSIBLY NEAR GALE FORCE AS ANOTHER
FRONT APPROACHES AND STRONG HIGH PRES MOVES OFF THE COAST.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ430-431.

&&

$$

SYNOPSIS...NIERENBERG
NEAR TERM...IOVINO
SHORT TERM...IOVINO
LONG TERM...NIERENBERG
AVIATION...IOVINO/NIERENBERG
MARINE...IOVINO/NIERENBERG


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