Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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647
FXUS61 KPHI 260642
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
242 AM EDT THU MAY 26 2016

.SYNOPSIS...
Our area will remain on the western periphery of an area of high
pressure located over the ocean off the east coast through the end
of this week into the weekend. A backdoor cold front may approach
the area from the north this weekend, but should end up remaining
to our north. An area of low pressure moving into New England early
next week is forecast to bring a cold front across our area around
Tuesday.

&&

.NEAR TERM /THROUGH TODAY/...
Prior to sunrise. Fair (variable cirrus). Light southwest or calm
wind.

After sunrise...A second mostly sunny very warm day is ahead with
a few locations in our forecast area likely nudging 90F for the
first time this year including KABE, KRDG, KPNE, KSMQ, KGED but
mainly northward from near PHL along and west of the NJT to KABE
and KRDG. Wind this afternoon south to southwest gusting to 15 mph.
A midday ocean influenced south southeast sea breeze will eventually
lower the near 80F late morning max temps significantly by mid
afternoon. Otherwise, high temps in the interior around 10-13F degrees
above normal. Pops withdrawn from e PA late today and it appears any
showers should develop after 6 pm there, if at all. Not much lift
mechanism despite weak instability burst.

Fcst basis: generally a 50 50 blend of the 00z/26 GFS/NAM MOS
guidance. Have checked all 00z/26 MAX temps tools from MET/MAV,
BIAS adjust of these as well as National and Super blend and basically
raised the highest of the warmest guidance away from the bays and
Atlantic coasts by 1-2F. That means the 89 at KPHL, 84 KMPO, 90 at
KABE and KGED as well as 89 at KFWN are all all fcst above the warmest
guidance...in part due to the initial westerly isobaric flow.

&&

.SHORT TERM /TONIGHT/...
Tonight...A small chance of a shower or maybe even an isolated
thunderstorm advancing eastward into our forecast area...toward
midnight, mainly eastern PA and e MD. Guidance lowered toward the
drier MET/ECMWF/UKMET guidance. Am not expecting much and my
confidence on any rain occurrence tonight is below average.
(00z/26 SPC WRF n/a but NSSL WRF was quickly reviewed).

A milder night than what is occurring early this Thursday morning.
Min temps around 10-13 degrees above normal.

Fcst basis was a 50 50 blend of 00z/26 GFS/NAM guidance except
favored the drier 00z/NAM MET pop guidance.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A summer like pattern continuing with a warm, above normal period
ahead for our area for the end of the week, through the weekend,
and into early next week. Also, chances of showers and
thunderstorms basically each day.

High pressure will remain to our east well offshore through the
end of the week into the weekend, with our area on the
western periphery. This will keep a southerly flow across the
area. Meanwhile, ridging aloft begins to take place as well. In
turn, thicknesses will rise into the weekend, helping
temperatures rise well above normal. Friday, Saturday, and Sunday
look to be the warmest days of the upcoming forecast period. By
Monday, the ridge aloft breaks down some, so the temperatures may
cool down a couple of degrees. However, the ridging may return for
Tuesday into Wednesday which would allow temperatures to rise a
few more degrees.

There will be a chance of isolated to scattered showers each
day, especially during the day with afternoon heating. The best
chance of shower/thunderstorm activity will be tied to individual
vorticity, short wave impulses.

A backdoor cold front may approach the area over the weekend,
but should stay north of the area. If it does make its way into
our northern areas, it could hold temperatures down on the
northern side, and possibly bring a higher shower potential. But
for now, we do not expect it to make its way into our area.

There is some timing differences with the next actual frontal
passage, with the GFS bringing the front through on Tuesday, and
the ECMWF bringing the front through on Monday. We`ll keep closer
to the GFS and and WPC with a late Tuesday passage. Either way,
there will still be a chance of showers and thunderstorms both
days.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Through 12z...VFR with variable cirrus. Small chance of isolated
MVFR VSBY near 10z vcnty KRDG or KMIV but dewpoints are so low
that fog is unlikely. Light south to southwest wind.

After 12z Today...VFR. Sct clouds aoa 6000 ft, mainly this
afternoon. South to southwest wind should gust 15 kt this
afternoon.

Tonight...VFR sct-bkn aoa 6000 ft. Small chance of a shower or
isolated tstm near 06z/27...mainly KRDG, KABE after 03z/27.

OUTLOOK...

FRIDAY-Monday...Generally VFR during the day through the period.
A chance of showers and thunderstorms, mostly during the day,
which may temporarily lead to lower conditions. Some fog
development overnight into the morning each day.

&&

.MARINE...
No marine headlines anticipated through Tonight.

Southwest winds with scattered gusts 15 kt this morning become
south to southeast this afternoon, also with gusts to 15 kt...then
return to southwest overnight-this coming Thursday night.

Seas aob 3 feet. Used the latest available more conservative NWPS
guidance (25/18z run).

OUTLOOK...

Friday-Monday...Sub-small craft advisory conditions expected.
Winds may gust near 20 knots, especially Thursday night through
Friday night.

&&

.CLIMATE...
The Philadelphia monthly average temperature continues to project
only about 1f below normal... with this current end of the month
stretch of above normal temperatures denting the first 24 days,
nearly 4 degree below average.

Also the Philadelphia month of May precip total of 5.14 inches
ranks 20th wettest dating back to 1872. Atlantic City has had 4.87
is ranked #21 wettest dating back to 1874 and Wilmington`s (DE)
5.55 inches ranks 18th dating back to 1894.

We may add more information by 5am Thursday.

&&

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

&&

$$
Synopsis...Drag/Robertson
Near Term...Drag 242
Short Term...Drag 242
Long Term...Robertson
Aviation...Drag/Robertson
Marine...Drag/Robertson
Climate...



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