Area Forecast Discussion
Issued by NWS Mt. Holly, NJ
FXUS61 KPHI 281921
Area Forecast Discussion
National Weather Service Mount Holly NJ
321 PM EDT Fri Oct 28 2016
Low pressure will gradually move away from coastal New England this
evening. Weak high pressure will build into our area overnight and
settle to our south over the weekend. A cold front will slide
southward across our area Sunday and Sunday evening as weak low
pressure tracks along it. High pressure will dominate on Monday. A
cold front is expected on Tuesday night and Wednesday followed by
another cold frontal passage on Thursday. High pressure will build
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Gusty conditions continue across the area this afternoon, but winds
will diminish this evening and overnight as the low to our northeast
pulls away and high pressure builds in across the area. Clouds will
clear out this evening and into the first half of the night as the
high pressure builds in, but clouds may increase again up north as a
warm front passes to our north toward daybreak.
With the light winds and mostly clear skies, temperatures will cool
rather efficiently. We still have several counties that remain in
their growing season, but we do not have any frost in the forecast
for these counties.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
For Saturday, the high pushes to our south while an area of low
pressure passes across southeast Canada and toward New England. Its
associated cold front will remain well to our west during the day
Saturday, so we only expect an increase in high level clouds during
the day across the area. Temperatures will warm well above normal,
and winds will likely become gusty during the day with gusts
reaching 20 to 25 mph at times.
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Synoptic Overview...The period starts off with a warm front across
Maine, a cold front draped across the eastern Great Lakes, and a
dome of high pressure sliding south across the mid-Atlantic and
southeastern states. On Sunday, the cold front will shift south
across the forecast area. As it does so, weak low pressure is
forecast to develop along the front. The front clears the coast on
Sunday night. By Monday morning, the cold front is forecast to be
well south of the area, across the Carolinas, as surface high
pressure builds into the northeastern U.S. On Monday night, the
surface high will slide east allowing a warm front/cold front regime
to set up across the Great Lakes. The warm front is forecast to be
north of our area on Tuesday. A cold frontal passage is currently
forecast for the Tuesday night/Wednesday time frame. Weak high
pressure will move in on Wednesday night, but will be short-lived.
Another cold frontal passage is expected on Thursday. High pressure
is forecast for Friday.
Temperatures...For perspective, normals for PHL are in the lower 60s
and mid 40s. While high temperatures on Sunday will depend on cloud
cover and the position of the cold front, they will be above normal.
We could see mid 70s in the Delaware Valley with some 80s across
southern Delaware. Temperatures are forecast to drop to near normal
on Monday and Tuesday and climb above normal Wednesday and Thursday.
Behind the cold front on Friday, temperatures will be near normal.
Precipitation...The first shot of precipitation will come mainly
later on Sunday and persist into Sunday night. All precipitation
will be in liquid form. The cold frontal passage on Tuesday night
and Wednesday looks dry at this time. POPS will be included for the
Thursday cold front. All precipitation looks to be in liquid form.
Winds...The strongest winds look to be right in the beginning of the
forecast period with a strong southwest push. They diminish on
Sunday and eventually go northwest behind the cold front. They`ll go
more northerly on Monday and turn southeast on Tuesday, but the flow
will remain fairly benign. They`ll turn offshore on Wednesday and
then southerly on Thursday ahead of the cold front. Later on
Thursday, behind the cold front, they`ll turn northwest and become
Impacts...The probability of hazardous weather is low through the
forecast period. The north and northwestern counties could see some
frost on Monday and Tuesday mornings, but the growing season has
ended. No freezing or frozen precipitation is expected during the
period and winds will be fairly benign.
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Generally VFR conditions expected tonight into Saturday.
Stratocumulus clouds this evening will thin out and be replaced by
high level clouds overnight and into Saturday. More stratocumulus
clouds could form during the day Saturday, and northern areas could
approach MVFR conditions.
Winds will continue to gust 20-30 knots this afternoon, before
diminishing after sunset. Winds will likely become light and
variable overnight as high pressure builds across the area. Winds
are expected to become southwest during the day Saturday and could
begin gusting 15-20 knots by the afternoon.
Saturday night...VFR except MVFR possible from about KABE to KTTN on
northward. Southwest winds 5 to 10 knots.
Sunday...VFR except scattered MVFR is possible once again as a cold
front settles southward across our area along with showers. West-
southwest winds around 10 knots, becoming north-northwest in the
afternoon and evening.
Monday through Wednesday...Generally VFR with no precipitation
We`ve upgraded the northern half of out Atlantic coastal waters to a
Gale Warning for the late afternoon and evening hours. Winds have
been gusting around 35-37 knots for a couple of hours and will
likely continue into the evening. The Small Craft Advisory remains
elsewhere as winds consistently are gusting 25-30 knots. There has
been an occasional gust around 35 knots here or there, but not
consistent enough for a Gale Warning at this time.
Winds are expected to diminish overnight and fall below Small Craft
Advisory levels after midnight. The sub-Small Craft Advisory
conditions will remain through much of the day Saturday before winds
increase again late in the afternoon.
Saturday night...Southwesterly flow increases Saturday ahead of a
cold front. The ocean waters could see a period of SCA winds late on
Saturday into Saturday evening.
Sunday and Sunday night...The front settles southward during the day
on Sunday and Sunday night with a wind shift to the north-northwest
in its wake. Gusts to 20 knots possible behind the front. No SCA
Monday through Tuesday...North winds diminishing and becoming
southeasterly. No SCA conditions expected.
Tuesday night and Wednesday...A cold front will make its way through
area waters. Southeast winds will become northwest behind the front.
No SCA conditions expected at this time.
Tidal levels along the Delaware Bay and tidal portions of the
Delaware River this evening will be around a foot lower than the
astronomical forecast, but are not expected to reach blow out
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ430-431-
Gale Warning until 10 PM EDT this evening for ANZ450-451.