Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 260138
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
938 PM EDT SAT APR 25 2015

.SYNOPSIS...
LOW PRESSURE NEAR THE TENNESSEE VALLEY WILL PROGRESS TO THE EAST,
PASSING OFF THE NORTH CAROLINA COAST LATE TONIGHT. HIGH PRESSURE
IS THEN FORECAST TO BUILD GRADUALLY INTO OUR REGION DURING THE
EARLY AND MIDDLE PARTS OF THE NEW WEEK. ANOTHER AREA OF LOW
PRESSURE IS EXPECTED TO PASS OFF THE NORTH CAROLINA COAST AND MOVE
OUT TO SEA ON THURSDAY. A COLD FRONT IS ANTICIPATED TO PASS
THROUGH OUR REGION AT THAT TIME, THEN HIGH PRESSURE FOLLOWS FOR
FRIDAY AND SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LOW PRESSURE OVER KENTUCKY THIS EVENING WILL TRACK EASTWARD
OVERNIGHT. MEANWHILE A FRONTAL BOUNDARY IS STALLED WELL TO OUR
SOUTH. AN UPPER-LEVEL TROUGH IN THE NORTHEAST BENDS BACK INTO THE
OHIO VALLEY WHERE AN UPPER LOW IS LOCATED. THIS FEATURE IS TENDING
TO SHEAR SOME EASTWARD, HOWEVER THERE IS A DECENT AMOUNT OF PVA TO
PORTIONS OF THE MID ATLANTIC. THE ASSOCIATED LIFT WITH THE SHORT
WAVE ENERGY COMBINED WITH WAA/ISENTROPIC LIFT IS GENERATING AN AREA
OF MAINLY LIGHT RAIN. THIS IS MOVING ACROSS PORTIONS OF OUR EASTERN
MARYLAND AND DELAWARE ZONES. THERE IS DRIER AIR FARTHER NORTH AND
WITH SOME CONFLUENCE THE RAIN IS HAVING A TOUGH TIME EDGING
NORTHWARD. IT DOES APPEAR IT COULD LIFT A BIT FARTHER NORTH PER THE
RAP, HRRR AND NAM, BUT PROBABLY NOT AS FAR NORTH AS THE GFS/ECMWF
SHOW. THE POPS WERE ADJUSTED SOME AND WE MAINTAINED A NARROW AREA OF
LIKELY TO CATEGORICAL ACROSS OUR FAR SOUTHERN DELMARVA AREA. THE DRY
LOW-LEVEL AIR EARLIER MAY HAVE RESULTED IN SOME ICE PELLETS AT THE
ONSET.

OTHERWISE, MID TO HIGH CLOUDS WILL STREAM ACROSS MUCH OF THE AREA
NORTH OF THE LIGHT RAIN SHIELD. IT IS UP NORTH WHERE THE CLOUDINESS
SHOULD BE THE HIGHEST AND NOT AS THICK, ALLOWING TEMPERATURES TO
POSSIBLY FALL A LITTLE FASTER WITH LIGHT WINDS. THIS MAY ALLOW FOR
SOME FROST TO FORM LATE, MAINLY FOR AREAS NORTH OF INTERSTATE 78. A
FROST ADVISORY THEREFORE REMAINS IN EFFECT FOR LATE TONIGHT AND
EARLY SUNDAY MORNING FOR PORTIONS OF NORTHERN NEW JERSEY AND THE
ADJACENT AREAS OF EASTERN PENNSYLVANIA.

THE HOURLY GRIDS WERE ADJUSTED WITH THE LATEST OBSERVATIONS, AND
THEN THE LAMP/LAV GUIDANCE WAS BLENDED IN.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL ADVANCE FARTHER
EAST AND OUT TO SEA THROUGH THE COURSE OF THE DAY. THROUGH THE
MORNING, THOUGH, THICKER CLOUDS AND A CHANCE FOR SOME LIGHT RAIN
WILL REMAIN FOR OUR SOUTHERN ZONES AS THIS SYSTEM PULLS AWAY. THE
REST OF THE FORECAST AREA CAN EXPECT MORE OF A PARTLY CLOUDY DAY
WITH SOME LIGHT NORTHERLY WINDS AND TEMPERATURES ONLY SLIGHTLY
BELOW LATE APRIL AVERAGES, MILDER THAN THE LAST FEW DAYS. MAXIMUM
TEMPERATURES ARE EXPECTED TO REACH MOSTLY THE LOWER TO PERHAPS
MIDDLE 60S, WITH SOME COOLER 50S ALONG THE COASTS OF NEW JERSEY
AND DELAWARE AND INTO THE HIGHER TERRAIN OF THE POCONOS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A PARTLY CLOUDY SKY IS EXPECTED FOR SUNDAY NIGHT. TEMPERATURES
ARE FORECAST TO DROP INTO THE UPPER 30S TO MIDDLE 40S RANGE IN
MUCH OF OUR REGION BY DAYBREAK ON MONDAY. SOME LOCATIONS IN
NORTHERN NEW JERSEY COULD FALL INTO THE MIDDLE 30S WITH PATCHY
FROST POSSIBLE.

WE SHOULD REMAIN UNDER THE INFLUENCE OF A MID LEVEL LOW OFF NOVA
SCOTIA DURING THE PERIOD FROM SUNDAY NIGHT INTO TUESDAY NIGHT. A
MID LEVEL TROUGH ROTATING AROUND THE LOW IS FORECAST TO PASS
OVERHEAD ON MONDAY. THE TROUGH IS EXPECTED TO BRING CLOUDS TO OUR
REGION FOR MONDAY INTO MONDAY NIGHT. ALSO, THERE IS A CHANCE OF
SHOWERS ON MONDAY INTO MONDAY EVENING. ANY RAIN SHOWERS ARE
EXPECTED TO BE LIGHT BEING THAT THE AIR MASS IS ANTICIPATED TO BE
QUITE DRY AND A FAIR AMOUNT OF EVAPORATION IS LIKELY.

A WEAK MID LEVEL RIDGE IS FORECAST TO APPROACH FROM THE WEST AND
NORTHWEST ON TUESDAY AS THE MID LEVEL LOW MOVES FARTHER OUT TO
SEA. THE RIDGE SHOULD PASS OVERHEAD ON WEDNESDAY. BOTH DAYS ARE
EXPECTED TO BE DRY.

THE MODELS CONTINUE TO DIFFER ON THE HANDLING OF THE MID LEVEL
LOW THAT IS ANTICIPATED TO DROP SOUTHEASTWARD ACROSS THE EASTERN
STATES LATE IN THE WEEK. ALSO, THERE IS DISAGREEMENT IN THE
DEVELOPMENT AND TRACK OF THE ASSOCIATED SURFACE FEATURES. WE WILL
CONTINUE TO FAVOR THE ECMWF SOLUTION WITH A COASTAL LOW PASSING
OFF THE NORTH CAROLINA COAST. IT CONTINUES TO APPEAR AS THOUGH
MOST OF ITS IMPACT WILL REMAIN TO OUR SOUTH AND EAST. WE SHOULD BE
INFLUENCED BY A COLD FRONT DROPPING THROUGH OUR REGION ON THURSDAY
AND WE WILL MENTION SOME CLOUDS AND A CHANCE OF SHOWERS FOR THAT
PERIOD OF TIME.

SURFACE HIGH PRESSURE FROM THE WEST AND DRY WEATHER ARE
ANTICIPATED TO FOLLOW FOR FRIDAY AND SATURDAY. A SHORT WAVE TROUGH
IN THE NORTHWESTERLY MID LEVEL FLOW MAY PASS OVERHEAD ON SATURDAY.
IT WILL HAVE LIMITED MOISTURE ASSOCIATED WITH IT AND WE ARE
EXPECTING NO MORE THAN SCATTERED CLOUDS AT THIS TIME.

DAYTIME TEMPERATURES ARE ANTICIPATED TO BE BELOW NORMAL FOR
MONDAY AND TUESDAY. THEY ARE EXPECTED TO BE NEAR NORMAL FOR
WEDNESDAY, THURSDAY AND FRIDAY, AND THEY MAY GO A BIT ABOVE NORMAL
FOR SATURDAY.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

REST OF TONIGHT...VFR WITH A CEILING AT OR ABOVE 8000 FEET /LOWEST
SOUTH/. SOUTHWEST WINDS AROUND 5 KNOTS BECOMING MOSTLY LIGHT AND
VARIABLE, THEN BECOMING NORTHERLY 5 TO 8 KNOTS TOWARD DAYBREAK. SOME
LIGHT RAIN MAY NEAR KMIV AND KACY OVERNIGHT FOR A TIME.

SUNDAY...VFR. SOME CLOUD BASES /SCATTERED/ DEVELOPING AT 5000 FEET,
AND A CEILING AT OR ABOVE 10000 FEET FOR SOME AREAS ESPECIALLY IN
THE MORNING. NORTH TO NORTHEAST WINDS MAINLY 5-10 KNOTS, BECOMING
NORTHWEST TOWARD LATE AFTERNOON.

OUTLOOK...
SUNDAY NIGHT...MAINLY VFR.

MONDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.

MONDAY NIGHT THROUGH WEDNESDAY NIGHT...MAINLY VFR.

THURSDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.

&&

.MARINE...
SUB-ADVISORY CONDITIONS WILL CONTINUE FOR THE COASTAL WATERS AND
FOR DELAWARE BAY. A LOW PRESSURE SYSTEM IS EXPECTED TO PASS TO THE
SOUTH OF THE REGION DURING THE OVERNIGHT TO EARLY SUNDAY, BUT
OTHER THAN SOME LIGHT RAIN AND A FEW WIND GUSTS TO 20 KNOTS FOR
THE SOUTHERN COASTAL WATERS, LITTLE IMPACT IS ANTICIPATED.

OUTLOOK...
SUNDAY NIGHT AND MONDAY...NO MARINE HEADLINES ARE ANTICIPATED.

MONDAY NIGHT...A NORTHWEST WIND MAY GUST AROUND 25 KNOTS.

TUESDAY THROUGH THURSDAY...NO MARINE HEADLINES ARE ANTICIPATED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FROST ADVISORY FROM 3 AM TO 8 AM EDT SUNDAY FOR PAZ061-062-105.
NJ...FROST ADVISORY FROM 3 AM TO 8 AM EDT SUNDAY FOR NJZ001-007>010.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

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



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