Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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956
FXUS61 KPHI 240738
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
238 AM EST Fri Nov 24 2017

.SYNOPSIS...
High pressure will shift offshore today. A cold front will move
across the area during the day Saturday. High pressure builds
across the region Monday, then offshore and to our south Monday
night into Tuesday. A cold front is expected later Tuesday into
Wednesday, though precipitation may dry out before reaching the
east coast. High pressure is expected to briefly build across
the area Wednesday night before weakening and lifting north of
the area Thursday ahead of the next storm system for the end of
the week.

&&

.NEAR TERM /THROUGH TODAY/...
The main feature through the near term remains the surface high
which remains over the Mid Atlantic. However, through the day,
the center of the high is expected to shift northeast, thus
allowing winds to shift from westerly to southwesterly and
eventually southerly. This slight shift, plus sunny conditions
all day, will help start warming trend.

Highs are expected to be 5 to 10 degrees higher than yesterday,
ranging from the mid 40s to mid 50s across the region.

&&

.SHORT TERM /TONIGHT/...
Overnight, we`ll be in between the departing surface high and
the approaching cold front. Clouds well ahead of the front could
begin to propagate into our area very late tonight. The light
southerly low level flow may temper radiational cooling slightly
as compared to the last few nights. Lows are expected to range
from the mid 20s to upper 30s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Fairly quiet weather is expected for most of the extended
period through next Thursday, with only a slight chance of
isolated showers this weekend.

A cold front will move across the area during the day Saturday.
Models continue to indicate small chances of precipitation as
the front moves across the area. PW values do approach one inch,
and there is some enhanced low-mid level moisture forecast as
the short wave/vorticity impulse and cold front move across the
area. So we will keep a slight chance of showers in the forecast
during the day Saturday. Portions of northeast Pennsylvania and
northwest New Jersey currently have best chance, although it is
only about 30%.

Northwest flow develops across the area behind the front
overnight Saturday night into Sunday. It is possible that some
isolated lake effect showers/flurries could make their way
across our area Saturday night into early Sunday morning in the
northwest flow. As usual, the Poconos have the better chance of
any showers. However, the flow from the Great Lakes gets cut off
during the day Sunday, so any showers are expected to end
during the morning.

Temperatures remain above normal Saturday before the front
moves through the area, but falls back to near normal or
slightly below for Sunday.

By Sunday night, high pressure begins to approach from the west
then fully builds across the area Monday. The high then pushes
offshore and to our south Monday night into Tuesday. This will
keep dry weather across the area into early next week.
Temperatures are expected to be warm back to above normal Monday
through Tuesday as return flow develops.

A cold front is forecast to move across the area Tuesday night
into Wednesday. Moisture associated with this front is expected
to dissipate as it approaches our area and the frontal passage
may end up being precipitation free. Even with the frontal
passage, temperatures are forecast to be above normal into
Wednesday. High pressure briefly builds across the area
Wednesday night, keeping dry conditions.

By Thursday, the high lifts to our northeast ahead of an
approaching storm system. In fact, a warm front may lift into
the area Thursday as an area of low pressure lifts through the
Great Lakes region. Therefore, there will be a slight chance for
isolated showers during the Thursday time period.

&&

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

Today...VFR conditions with hardly any clouds. Wind speeds will
be less than 10 KT, but the direction will be shifting from
westerly to southwesterly and eventually southerly. High
confidence on all aspects of the forecast.

Tonight...VFR conditions expected. Mid level clouds may be on
the increase very late tonight. Winds will generally be
southerly at 5 KT or less, but could become light and variable.
High confidence on all aspects of the forecast.

OUTLOOK...

Saturday-Saturday night...Generally VFR. Isolated showers
possible which may occasionally lower conditions. Southwest
winds early Saturday, becoming west to northwest and gusting
20-25 knots Saturday night. Moderate to high confidence on VFR
conditions. Low to moderate confidence on showers and sub-VFR
conditions. High confidence on winds.

Sunday-Tuesday...VFR expected. Northwest winds gusting 15-20
knots Sunday and Monday, then southwest winds gusting 15-20
knots Tuesday. High confidence.

&&

.MARINE...
Winds and seas will stay below small craft advisory criteria today
and tomorrow. The southeasterly 10 second swell continues through
this period. High confidence.

OUTLOOK...

Saturday...Sub Small Craft Advisory conditions expected,
although seas may be around 4 feet at times Friday night into
Saturday.

Saturday night-Sunday night...Small Craft Advisory conditions
likely behind cold frontal passage.

Monday-Monday night...Conditions falling below Small Craft
Advisory levels later Monday into Monday night.

Tuesday...Conditions may return to Small Craft Advisory levels
later on Tuesday.

&&

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

&&

$$

Synopsis...Robertson
Near Term...Johnson
Short Term...Johnson
Long Term...Robertson
Aviation...Johnson/Robertson
Marine...Johnson/Robertson



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