Area Forecast Discussion
Issued by NWS Mt. Holly, NJ-- Highlight Changed Discussion --
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FXUS61 KPHI 240027
Area Forecast Discussion
National Weather Service Mount Holly NJ
827 PM EDT Fri Sep 23 2016
A cold front will move across the area tonight. High pressure will
build across the northeast over the weekend into early next week. A
warm front is expected to lift north of the area around Monday,
while a cold front moves across the area around Tuesday. The front
will push out to sea Wednesday, while high pressure builds in for
the end of the week.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 7 PM EDT, the cold front was just to our northwest and
should arrive in the Poconos, NW NJ, and Lehigh Valley within the
next 2 hours. Have kept the mention of slight chance and chance of
thunderstorms across the far north as a few showers and storms
have developed along the front, but coverage is very limited. A
few showers may spread south into central NJ and along the NJ
shore after midnight.
Can expect a BKN-OVC mid-deck to spread through the region late
tonight and into daybreak Saturday. A brief period of sprinkles is
possible, but not expecting much in the way of measurable QPF south
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
Cold front continues to work its way south through the CWA on
Saturday. May take some time to clear southern DE/MD zones, so the
cooler and dryer air may not get there until late in the day. Few
lingering showers possible along the NJ shore early, but those will
taper off by midday.
Clouds will give way to increasing amounts of afternoon sunshine
from north to south. Temps will return to seasonal levels, generally
topping off in the mid to upper 60s across the Poconos and into
northern NJ, and in the low to mid 70s for most of PA/NJ. MD/DE will
be a bit warmer, generally in the mid to upper 70s.
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
High pressure will remain in control of the weather Saturday night
through Monday. Cool conditions, along with a dry forecast are
expected through Monday.
By Monday night, a warm front is expected to have lifted north of
the area. If there are any weak short wave/vorticity impulses
overnight Monday, a few isolated shower could possibly develop,
On Tuesday, a cold front is expected to move across the area. The
ECMWF is faster than the GFS, which brings the front across the area
overnight Monday into Tuesday morning. The GFS brings the front
across the area during the day Tuesday, as does the Canadian model.
We will continue with an expectation of a Tuesday frontal passage,
keeping Tuesday as the period with the greatest POPs.
The front is expected to have pushed offshore by Tuesday night and
out to sea Wednesday. High pressure will build back across the area
for the end of the week. It is possible that a few isolated showers
are possible in the northwest flow Wednesday as a short wave moves
across the area. However, the remainder of the week Thursday and
Friday will remain dry.
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Cold front should arrive at the TAF sites between 01Z for KABE and
as late as 06 or 07Z for KACY. Isolated showers and thunderstorms
are possible with the front, but coverage is so limited that I do
not have the confidence to include in any of the TAFs (though the
highest risk would be at KABE). Winds should quickly shift to
northerly with the front, but generally remain near 10kt. MVFR
ceilings are expected to propagate in over the region a few hours
behind the initial frontal passage. At this point we are expecting
ceilings generally between 2000 and 3000 ft AGL. However, upstream
obs show IFR and even LIFR ceilings further north, so will
continue to monitor as the front gets closer.
Ceilings gradually lift to VFR Saturday morning from N to S.
Saturday night-Monday...VFR conditions expected.
Monday night-Tuesday night...MVFR early Monday night, possibly
lowering to MVFR by Tuesday, improving back to VFR Tuesday night. A
chance of showers, especially Tuesday.
A cold front approaches from the north this evening and slowly works
its way south tonight through Saturday morning.
Behind the passage of the cold front, winds become N, and then NE.
for ANZ450-453, can expect a period of 25 KT wind gusts, and seas
will build to around 5 ft. Will hoist a Small Craft Advisory for
those zones from early Saturday morning through Saturday afternoon.
For southern ocean waters, think gusts will be marginal at best, and
seas may only briefly touch 5 FT. Will hold off on SCA for those
waters. Conditions should remain below SCA criteria on DE Bay.
Saturday night-Monday...Sub-Small Craft Advisory conditions expected
through. Winds may gust around 20 knots at times.
Monday night-Tuesday night...Small Craft Advisory level winds
possible ahead of and behind a cold frontal passage.
Wednesday...Sub-Small Craft Advisory conditions return.
There is a moderate risk for the formation of dangerous rip
currents for both the NJ shore and the DE beaches on Saturday. The
moderate risk may continue into Sunday.
MARINE...Small Craft Advisory from 6 AM to 6 PM EDT Saturday for ANZ452-
Small Craft Advisory from 4 AM to 6 PM EDT Saturday for ANZ450-