Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 150713
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
213 AM EST Wed Nov 15 2017

.SYNOPSIS...
High pressure will continue to influence our weather through
today before moving off the coast. A cold front approaching
from the northwest is forecast to arrive on Thursday followed by
high pressure for Friday. Another cold front is expected to
pass through our region on Saturday night with high pressure
anticipated in its wake for Sunday and the early part of the new
week.

&&

.NEAR TERM /THROUGH TODAY/...
215 AM ESTF: Clouds thinning rapidly attm so will adjust early
morning lows back down.

The new 330 am fcst is basically published and posted.

Early this morning...monitoring sprinkles offshore and suspect
that they will remain there... second time within about 10 days
that we`ve seen this at night. Patchy fog-frosty where clearing
of thin deck at 5000 ft now occuring.


Today...Its a model rh time section battle between the NAM and
GFS. An inversion near 800 MB caps moisture below it and overall
am thinking the cooler more moist NAM will prevail. So this
forecast was a blend of the 00z/15 GFS/NAM MOS but LOW confidence
on having made the correct decision on more clouds than sun.
For now...am fcstg temps no higher than 2F above the blended
GFS/GGEM/NAM 18z 2m temps. Light east to southeast winds. If
there is a shower along the coast, it should be this Wednesday
morning.

&&

.SHORT TERM /TONIGHT/...
Cloudy and relatively mild with nearly steady temps, possibly
rising a bit during the night along and east of I-95. Showers
ahead of a cold front are expected to develop, mainly after
06z/16 as per HRRRX NAM/GFS...mostly likely toward 09z/16. That
means a band moving from w to E across PA/MD into our western
zones around 06z and meanwhile showers sprouting ahead of the
main band in DE/NJ. Amounts .05 to 0.25". Less than average
confidence on rainfall ILG/MIV southward but the 00z/EC has .10
or greater over virtually all of our area 6z-12z Thu. The
drivers for the rainfall area area 100m 500mb height falls over
our area ahead of a modeled 160M 12 hr HFC vt max sliding sewd
through sw NYS at 12z Thu, also a nice 850 trough with
considerable absolute vorticity in its axis as it crosses our
area by 12z. That and some pretty good jet cores at 850-40 kt
700mb-55kt aiding the forcing.

This forecast was a 50 50 blend of the 00z/15 GFS/NAM MOS.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Showers may linger into Thursday morning, especially in the
northern and eastern parts of our forecast area prior to a CFP.

High pressure is forecast to build across our region from west
to east on Thursday night and Friday, bringing dry weather
conditions.

A strong cold front is forecast to approach from the west on
Friday night and Saturday. There is an increasing chance of
showers beginning late on Friday night. It appears as though
temperatures should increase slowly as the cloud cover lowers
and thickens. As a result, we are not anticipating any freezing
or frozen precipitation at the onset.

The cold front is forecast to push through our region on
Saturday night. Another blast of cold air is expected to follow
for Sunday and Monday. We continue to use the low end of
guidance for temperatures. Cold advection stratocumulus is
anticipated, especially on Sunday. Also, scattered snow showers
and flurries are possible in our northern counties, mainly in
the elevated terrain.

Temperatures may warm a bit on Tuesday as the center of the
high moves out to sea.

&&

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

Early this morning...VFR CIGS generally based near 5000 ft with
spotty MVFR CIGS along the coast. CIGS may become sct clouds,
especially vcnty KABE/KRDG/KTTN by 10z. This per the sliver of
clear sky as seen on satellite imagery is developing slowly west
through e MD e PA and nw NJ.  Light north to northeast wind.

Today...Confidence lowers on the scenario but we are are not
using the NARRE which is off to a poor start in our forecast
area. Reliance will be on a visually blended GFS/NAM Tsection.
That will mean generally VFR conditions...probably cigs based
near 4000 or 5000 ft with a possibly MVFR CIG here and there,
especially late in the day when MVFR CIGS may become much more
widespread. Light northeast wind to start becoming southeast
this afternoon. Confidence in CIG forecast height is well below
average, and for winds is above average.

Tonight...VFR or MVFR CIGS to start, then degrading to probable
IFR conds toward 09z/16 in showers stratus fog with stratus fog
contg even after showers end vcnty Philly westward near 11z (no
mixing). Confidence above average on sub MVFR conditions late
at night. Light southeast wind becomes light southwest or west
toward 11z/16.

OUTLOOK...
Thursday morning...Mainly VFR. However, rain showers may reduce
conditions to MVFR at times.

Thursday afternoon through Friday evening...Mainly VFR.

Friday night...VFR lowering to MVFR in spots. A chance of
showers after midnight.

Saturday and Saturday night...Mainly MVFR and VFR with showers
likely. Snow showers are possible around KRDG and KABE late on
Saturday night.

Sunday...Mainly VFR.

&&

.MARINE...
Small craft advisory for the Atlantic waters from Cape May to
Fenwick Island through 6 pm today as seas will likely stay
elevated through this afternoon, especially with a modeled
slight increase in northeast wind this morning. Winds may
briefly gust to 25 kts, especially off the Delaware coast, but
the main threat will be elevated seas of around 5 to 6 feet.

There is a change of sprinkles or a light shower through much
of the period, generally from the southern New Jersey coast
southward.

Tonight...No marine headlines but rereviewing for the 330 am
fcst.


OUTLOOK...
Thursday morning...No marine headlines are anticipated.

Thursday afternoon through Friday morning...Northwest wind
gusts of 25 to 30 knots are expected. A few hours of gale force
gusts are possible on Thursday evening.

Friday afternoon and Friday night...No marine headlines are
anticipated.

Saturday and Saturday evening...Gale force gusts from the
southwest are possible.

Late Saturday night and Sunday...Gale force gusts from the west
and northwest are possible.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 6 PM EST this evening for
     ANZ451>453.
     Small Craft Advisory until 6 AM EST Thursday for ANZ454-455.

&&

$$
Synopsis...Iovino
Near Term...Drag 213
Short Term...Drag 213
Long Term...Iovino
Aviation...Drag/Iovino
Marine...Drag/Iovino 213



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