Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 031942
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
342 PM EDT FRI JUL 3 2015

.SYNOPSIS...
A WEAK HIGH PRESSURE SYSTEM WILL REMAIN OVER NEW ENGLAND TONIGHT,
BEFORE MOVING OFFSHORE ON SATURDAY. MEANWHILE, LOW PRESSURE OVER
THE OHIO VALLEY WILL MOVE ALONG A STALLED FRONTAL BOUNDARY TO OUR
SOUTH AND PASS EAST OF THE DELMARVA PENINSULA ON INDEPENDENCE DAY.
ANOTHER AREA OF HIGH PRESSURE WILL THEN MOVE INTO THE REGION FOR
THE END OF THE HOLIDAY WEEKEND AND MONDAY. A WEAK LOW PRESSURE
SYSTEM MIGHT EASE NORTH INTO THE AREA ON TUESDAY AS ANOTHER COLD
FRONT APPROACHES THE FORECAST AREA BY MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WILL BEGIN THE NIGHT WITH STILL RATHER PLEASANT CONDITIONS AS THE
HIGH CONTINUES TO SLIDE AWAY FROM THE REGION. WILL LIKELY NOT BEGIN
TO SEE THE EFFECTS OF THE APPROACHING LOW UNTIL AFTER MIDNIGHT. ONE
THING WE`LL BE WATCHING CLOSELY IS THE LOW LEVEL WINDS OVERNIGHT.
LOW AND MID LEVEL FLOW TODAY ENDED UP BEING CONSIDERABLY LIGHTER
THAN WAS PREVIOUSLY FORECAST, NOT TO MENTION THAT WIND DIRECTION AT
THE SURFACE WAS VARIABLE FOR MUCH OF THE DAY. THUS, RELATIVELY DRY
AIR REMAINS IN PLACE IN THE BOUNDARY LAYER. AS A RESULT, EVEN THOUGH
WE MAY HAVE THE BEST SYNOPTIC SCALE LIFT IN PLACE BY 12Z, START OF
RAIN (OR AT LEAST INCREASE IN INTENSITY OF RAIN) MAY BE DELAYED BY A
FEW HOURS.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
STILL LOTS OF UNCERTAINTY IN THIS PERIOD. THERE IS CONSIDERABLE
DISAGREEMENT BETWEEN MODELS AND RUN-TO-RUN ON INDIVIDUAL MODEL RUNS.
FOR THE MOST PART, THE MAIN DETERMINISTIC MODELS HAD A SLIGHTLY
DRIER TREND WITH THE 12Z RUNS. HOWEVER, THIS HAS BEEN THE CASE THE
LAST FEW DAYS, WITH THE 00Z RUNS TENDING TO BE WETTER SOLUTIONS. AT
THIS POINT, THINK THE HIGHEST CHANCES WILL STILL COME BEFORE 21Z.
THINK THAT IT WILL MOSTLY BE A STEADY RAIN GIVEN A RATHER STABLE
ATMOSPHERE IN PLACE. AS FAR AS RAIN AMOUNTS, HAVE FAVORED LIGHTER
AMOUNTS GIVEN THE UNCERTAINTY OF HOW MUCH MOISTURE ADVECTION WE WILL
HAVE. MOST MODEL SOLUTIONS CONTINUE TO SHOW THE PRECIP LIFTING OUT
QUICKLY FROM MID TO LATE AFTERNOON.

WITH ALL THE CLOUD COVER IN PLACE, IT LOOKS TO BE A RATHER COOL DAY
(HIGHS IN THE 60S AND 70S).

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
ANY LINGERING PRECIP SHUD BE ENDING ERLY SAT EVE WHICH SHUD HAVE
A POSITIVE IMPACT ON ANY FIREWORKS DISPLAYS AND OTHER HOLIDAY
FESTIVITIES.

HIGH PRES WILL THEN BUILD IN FOR SAT NIGHT THRU MON KEEPING THIS
PD DRY OVER MOST, IF NOT ALL OF THE AREA. THE ONLY LOCATION THAT
GUID IMPLIES CUD SEE SOME PRECIP WUD BE OVER THE DELMARVA COME
MON.

BY MON NIGHT INTO TUE, ANOTHER QUICK WV MOVES THRU, THEN THE GFS
IS MUCH FASTER WITH A CDFNT FROM THE W, BRINGING IT THRU BY WED
MRNG AND THE ASSOCD PRECIP. THE CMC AND ECMWF ARE MUCH SLOWER
BRING THE FRONT THRU LATER WED INTO WED NIGHT. IF THE EC IS TO BE
BELIEVED, WITH THE SLOWER FRONTAL TIMING, TUE NIGHT INTO ERLY WED,
CUD BE DRY AND WED CUD BE ON THE HOT SIDE AHEAD OF THE FRONT. THEN
THE ECMWF DEVELOPS WHAT APPEARS TO BE A VERY STRONG WAVE FOR FRI
THAT THE GFS DOESN`T HAVE, AND IS SUBSEQUENTLY DRY.

ONCE AGAIN, CONFIDENCE IS LOWER THAN AVERAGE. THERE WILL BE A CFP.
HAVE SHADED THIS FCST TWD THE MDL CONSENSUS AND THE SLOWER
TIMING, BUT, NOT SURE ON THE MOST LIKELY PDS OF PRECIP AS A RESULT
OF THE UNCERTAINTY. FOR NOW, AM JUST CARRYING LOW POPS FOR FRI, AS
WE HAVE A WEEK TO SEE WHAT, IF ANYTHING, DEVELOPS.

TEMPS WILL START OFF NR NRML AND RISE TO ABV NRML VALUES BY THE
MIDDLE AND END OF THE WEEK.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS WITH LIGHT WINDS (GENERALLY NEAR OR BELOW 5 KT) WILL
CONTINUE THROUGH AT LEAST 00Z. RAIN MAY START MOVING INTO THE AREA
AS EARLY AS 03Z, BUT MORE LIKELY AFTER 09Z. ONCE THE RAIN BEGINS,
CONDITIONS WILL LOWER TO MVFR. FOR KACY, KMIV, KILG, AND KPHL, A
PERIOD OF IFR CONDITIONS IS POSSIBLE SOMETIME BETWEEN 12 AND 18Z.
IFR CONDITIONS FOR THE OTHER TAF SITES APPEARS UNLIKELY, BUT NOT OUT
OF THE QUESTION. WIND DIRECTION WILL ONCE AGAIN BE A BIT VARIABLE
INTO THIS EVENING, BUT SHOULD SETTLE INTO A SOUTHEASTERLY DIRECTION
AROUND OR AFTER 00Z.

OUTLOOK...

SAT NIGHT...SOME MVFR FOG PSBL AT THE MORE RURAL ARPTS, OTHERWISE
VFR.   HIGH CONFIDENCE.

SUN THRU TUE NIGHT...VFR SUN AND SUN NIGHT. HIGH CONFIDENCE. VFR
MON AND TUE OUTSIDE OF ANY SHRA/TSRA MAINLY IN THE AFTNS.

WED...PREDOMINATELY VFR, BUT DECREASING TO MVFR/IFR WITH
INCREASING CHCS OF SHRA/TSRA, ESPECIALLY W AS CDFNT APPROACHES.
MDT CONFIDENCE.

&&

.MARINE...
WINDS AND SEAS SHOULD STAY BELOW SCA CRITERIA TONIGHT INTO TOMORROW
MORNING. BY TOMORROW AFTERNOON, WINDS AND SEAS COULD BUILD NEAR 25
KT/5 FT, PRIMARILY ON THE NORTHERN ATLANTIC WATERS. HOWEVER, THERE
IS CONSIDERABLE UNCERTAINTY.

OUTLOOK... SAT NIGHT AND SUN...THERE IS STILL SOME UNCERTAINTY
WITH THE STRENGTH AND TRACK OF THE LOW, BUT IT APPEARS THE BEST
CHC OF SEAS ABOVE SCA CONDS WILL BE EARLY SAT NIGHT AND PSBLY SOME
MRGNL WIND. HOWEVER, CONFIDENCE IS LOW ENOUGH AT THE MOMENT TO
HOLD OFF ISSUING ANY FLAGS ATTM. THE BEST CHCS APPEAR TO BE ON THE
NRN WATERS. AFTER ANY SCA LINGERING INTO THE MRNG, THE CONDS SHUD
DECREASE BELOW SCA LATER INTO SUN.

SUN NIGHT THRU WED...NO MARINE FLAGS ARE ANTICIPATED.

&&

.TIDES/COASTAL FLOODING...
WITH CONTINUED WEAK ON SHORE FLOW, HIGH TIDES THIS EVENING AND
SATURDAY EVENING COULD APPROACH THE MINOR FLOODING LEVEL, BUT
RIGHT NOW NO SITES ARE FORECAST TO REACH LEVELS NEEDED FOR A
COASTAL FLOOD ADVISORY. SAT NIGHT AND SUN LOOK TO BE THE SAME WAY.
WHILE SOME SITES MAY APPROACH MINOR TIDAL FLOODING LEVELS, CURRENT
DATA INDICATES THEY WILL REMAIN BELOW CRITERIA.

&&

.RIP CURRENTS...
THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING ALONG THE
NEW JERSEY SHORE. BY TOMORROW, A MODERATE RISK OF RIP CURRENTS IS
LIKELY FOR BOTH NEW JERSEY AND DELAWARE.

&&

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

&&

$$
SYNOPSIS...NIERENBERG
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...NIERENBERG
AVIATION...JOHNSON/NIERENBERG
MARINE...JOHNSON/NIERENBERG
TIDES/COASTAL FLOODING...JOHNSON/NIERENBERG
RIP CURRENTS...JOHNSON


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