Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 280155
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
955 PM EDT Wed Mar 27 2024

.SYNOPSIS...
A slow moving front will approach our region from the west tonight,
then a wave of low pressure will track northeastward off the coast
on Thursday resulting in a period of unsettled weather. A weak clipper
system may move through on Saturday, otherwise dry and seasonable
conditions will prevail over the weekend. Another rain making system
will impact the region early next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
No major changes with the late evening update. The cold front,
now as close as central PA, continues to approach from the west,
and moves into eastern Pennsylvania late tonight. Meanwhile,
surface low pressure will organize and develop over the Gulf of
Mexico just ahead of the front.

We expect to have a few hours lull from widespread rain (though
a few showers will remain in the region this evening). After
midnight, rain will spread into the region from the south. The
cold front will be through the region and just offshore by
daybreak Thursday, where it will become nearly stationary
through the day. Rain continues to develop on that front,
primarily over eastern New Jersey and Delmarva throughout the
day. The surface low will move into the Mid-Atlantic by Thursday
afternoon, and the heaviest rain will be focused on the front.

A light onshore flow will prevail for most of tonight. Winds then
turn north and increase to 10 to 15 mph with gusts up to 20 mph by
Thursday afternoon as the pressure gradient tightens up as high
pressure builds in from the north and west.

Total rainfall will range from 0.25 inches or so over the southern
Poconos and Lehigh Valley to as much as 0.75 inches down to the I-95
corridor. In general, 1 to 1.5 inches of rain will fall east of the
I-95 corridor and as much as 2 inches of rain is possible along the
New Jersey and Delaware coasts.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
The upper trough will move offshore Thu night carrying the front and
low pressure with it. Rains that are still around during the evening
will exit the area overnight. Patchy fog will be possible overnight.
Lows will reach the mid/upper 30s for most spots and some low 30s
for the far NW areas. Increasing NW winds 10 to 15 mph with gusts up
to 25 mph possible.

Cooler and drier air move in Friday as a decent pressure gradient
develops between the departing low and high pressure dropping down
from Canada. Under mostly sunny skies, temperatures will rise into
the 50s for most spots, about normal for late March. Gusty NW winds
will continue mostly 10 to 20 mph.

The short term ends up mostly dry most spots, but a weak low will
move thru Sat afternoon and evening and a few scattered showers are
possible. We`ll just have some small chance pops over the area.
Milder temps are predicted with highs reaching the upper 50s/low 60s
for much of the area.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
After some showers Sat night, pleasant weather is expected for the
last half of the weekend. A variety of weak systems crossing thru
the Middle Atlantic and Northeast Sunday and Monday, but weak high
pressure will be over the region Sunday followed by weak low for
Monday, so we will have chance pops for then. Rather mild Sunday but
then temperatures moderate back to below normal Monday with more
clouds present.

The upper pattern becomes more energized towards the middle of next
week with a strong trough across the far SW part of the country
ejecting a few shortwaves while another low drops SE out of central
Canada. OP models from 12Z show a rather potent low forming across
the Ohio Valley and moving NE. We should be affected by the
associated fronts, if not the low itself. We`ll go along with the
latest NBM and have likely pops for Tue night into Wed then back to
chance pops for Wed night/Thu. Plenty of uncertainty with this
period overall. Temperatures look to be around normal or perhaps a
degree or two below for the most part.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...Expect conditions, primarily ceilings to gradually
lower through the next several hours. We may continue to see
some sites briefly jump to MVFR or even VFR (especially KTTN and
KABE), but should see widespread IFR by 06Z. Visibilities should
be more variable, but are likely not to be the controlling
factor. LGT/VRB winds, becoming N 5 to 10 kt prior to 12Z
Thursday. High confidence on the overall pattern, but low
confidence on timing details.

Thursday...IFR/LIFR CIGs/VSBYs in the morning in RA/BR. Conditions
slowly improve to MVFR by midday, and then to VFR prior to 00Z
Friday. Sub-VFR conditions expected at KMIV/KACY all day. N
winds becoming NW 10 to 15 kt with gusts up to 20 kt. Moderate
confidence.

Thursday night...Mostly VFR. Northwest winds 10 to 15 KT gusting
up to 20 kt. Could see a low level jet develop near or after
06Z, but expect surface winds to be well enough mixed to prevent
any low level wind shear concerns. Moderate confidence.

Outlook...

Friday... VFR. Gusty NW winds.
Fri night/Saturday... Mostly VFR.
Sat evening and night... VFR/MVFR. Scattered showers.
Sunday into Monday... Mostly VFR then lower conditions possible
with showers Monday.

&&

.MARINE...
Light onshore flow this evening becomes N 5 to 10 kt late tonight,
and then winds become N-NW 10 to 15 kt with gusts up to 20 kt by
Thursday afternoon.

Seas remain elevated at 4 to 6 feet for most of tonight, and seas
will gradually subside to less than 5 feet by Thursday morning. The
Small Craft Advisory will remain in effect for most of tonight,
ending from north to south after midnight.

VSBY restrictions in rain and fog tonight and Thursday with VSBYs 1
to 3 NM.

Outlook...
Thu night/Friday... Gale watch continues for this period. Gales, if
the occur, diminish to SCA level winds/seas later Friday. Rains Thu
night then Fair Friday.

Fri night/Saturday... SCA conditions continue until Sat morning then
sub-SCA. Fair weather.

Sat night thru Sunday... sub-SCA. Scattered showers Sat night then
Fair Sunday.

&&

.TIDES/COASTAL FLOODING...
Coastal Flood Advisories have expired in Ocean County, NJ and
Sussex County, DE. No coastal flooding headlines are in effect
at this time. Some spotty minor flooding in the back bays
remains possible within the back bays of Barnegat Bay and Little
Assawoman Bay, but the threat is not expected to be widespread.

The current forecast has the Delaware River at Burlington
falling just below advisory-minor, so have elected on holding
off on an Advisory for now. Some spotty minor flooding remains
possible near the Delaware River and surrounding tributaries
with tomorrow morning`s high tide in Burlington County, NJ and
Bucks County, PA.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Gale Watch from Thursday evening through Friday afternoon for
     ANZ430-431-450>455.
     Small Craft Advisory until 4 AM EDT Thursday for ANZ450>453.
     Small Craft Advisory until 7 AM EDT Thursday for ANZ454-455.

&&

$$

SYNOPSIS...Staarmann
NEAR TERM...Johnson/MPS
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...Johnson/MPS/OHara
MARINE...MPS/OHara
TIDES/COASTAL FLOODING...Hoeflich


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