244
FXUS61 KPHI 130138
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
938 PM EDT Sun May 12 2024

.SYNOPSIS...
Low pressure over southeastern Pennsylvania this afternoon will
move offshore this evening. High pressure builds south of the
Mid-Atlantic region tonight into Monday. Another area of low
pressure brings more unsettled weather by the middle of next
week.

&&

.NEAR TERM /THROUGH MONDAY/...
Broad high pressure will remain across the East Coast and
strengthen some overnight, then shift offshore into Monday.
Clouds will scatter out early in the night as drier air filters
in, however areas of fog and some stratus will form overnight
with radiational cooling and light winds. Dense fog currently
appears unlikely. Low temperatures will be in the 40s.

Quiet weather makes a brief return Monday. Initially cloudy and
foggy conditions will scatter out by late morning, with
scattered clouds remaining into the afternoon. Temperatures
will warm into the lower to mid 70s under broad scale
subsidence. Winds will increase from the south to southwest near
10 mph.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
Fair weather will continue Monday night with high pressure
remaining offshore and dry air remaining in place. Seasonable
temperatures continue with lows Monday night in the 50s.

Poor weather will return for Tuesday into Wednesday as low
pressure slowly deepens across the Ohio valley and advances
slowly towards the Middle Atlantic. The low should tap into some
moisture across the Appalachians and it will be carried up over
our region. A period of rains and perhaps a few tstms are
expected for the period. Plenty of likely/categorical pops for
Tue night/Wed. Temperatures will be little above normal Tue, but
then get scaled back for Wed with plenty of clouds and rains
around. Highs Wed will mostly be in the mid/upper 60s. Rainfall
from the midweek system could range from 1 1/2 inches for
Delmarva and SE NJ to around 1/2 inch for the NW areas.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
In the wake of the system from the short term, improving
conditions are set for Wednesday night with only chance pops in
the grids for Wednesday evening. After that, upper ridging and
weak surface high pressure settle across the Middle Atlantic and
Northeast. A mild night is expected with lows in the mid/upper
50s.

A short period of mostly fair weather to end the upcoming week
is foreseen presently. The upper ridge diminishes while high
pressure moves offshore. We can`t rule out a couple isolated
showers Thu afternoon, but pops will only be slight chance for
now and won`t appear in the text products. Seasonable
temperatures expected with highs in the low/mid 70s.

Later Friday and into next weekend look unsettled (again!). A
northern stream upper trough moves across the Great Lakes and
tries to absorb some moisture from the Ohio Valley. We`ll carry
some chance pops for Fri night and Saturday for now and keep
lower chance pops into Sunday. There is enough uncertainty with
regards to these periods for now, so check back in a few days
for better details.

&&

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

Tonight...Any lingering MVFR ceilings will scatter out through
03Z or so, however a return to MVFR or even IFR conditions is
anticipated overnight. Ceilings 1-2K ft form once again after
06Z in southeast PA, northern Delmarva, and inland NJ with
moisture trapped at low levels and light/variable winds. Some
fog development should also occur in some areas. Lower
confidence on whether restrictions will come in the form of fog
or stratus, however most terminals are expected to have MVFR to
IFR restrictions 10-12Z.

Monday...Low clouds and fog scatter out 13-16Z, then VFR with
scattered clouds lingering. South to southwest winds increasing
to near 10 kts. High confidence in prevailing VFR by 18Z at all
terminals.

Outlook...

Monday night through Tuesday...No significant weather expected.

Tuesday Night through Wednesday night...Sub-VFR conditions
expected with occasional showers.

Thursday/Friday...No significant weather expected.

&&

.MARINE...
No marine headlines are in effect through Monday. East to
Southeast winds 10 to 15 kts this afternoon will diminish to
around 5-10 kts tonight. South wind around 10 knots Monday. Seas
of 3-4 feet. Scattered rain showers through this afternoon.

Outlook...

Monday night...No marine headlines expected.

Tuesday through Wednesday...SCA conditions possible (30-40%) as
wind gusts get near 25 kt. Significant wave heights approach 6
feet Wednesday. Occasional showers.

Wednesday night and Thursday... SCA seas possible, diminishing
Thu. Showers Wed night then mostly Fair Thursday.

&&

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

&&

$$

SYNOPSIS...Deal/Franklin
NEAR TERM...Franklin/Staarmann
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...Franklin/OHara/Staarmann
MARINE...Franklin/OHara