078
FXUS61 KPHI 070541
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
141 AM EDT Tue May 7 2024

.SYNOPSIS...
A cold front will work its way through the region tonight before
becoming nearly stationary south of Delmarva. Low pressure tracks
along the front late tonight through Tuesday morning. Another area
of low pressure passes through the region on Wednesday followed by a
stronger low on Thursday. A cold front passes through on Friday,
then several disturbances are possible this weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Forecast is on track this morning. No real changes made. A cold
front is slowly sliding through. Some patchy fog has developed
out ahead of it. Some fog could be locally dense, though not
expecting it to be as widespread as yesterday morning. Otherwise,
a cold front will slowly slide south across the area tonight
and with a weak wave of low pressure track along it the best
best forcing for ascent and RH is across the southern areas
(highest PoPs will be here for the overnight). Overnight lows
will be in the lower 50s to lower 60s.

Weak low pressure will be just east of Delaware Tuesday morning.
This will keep some showers in the forecast through at least
the daybreak hours. Some showers and possibly a few
thunderstorms are expected to decrease by lunchtime as low
pressure moves offshore. PoPs won`t be zero for the remainder of
the day for all areas, but the most showers should be in the
morning. Afternoon highs will be in the 70s for most places.

Another area of low pressure will track from the Great Lakes into
the Ohio Valley. A warm front extending out from that system will
lift towards southwest portions of the area later in the day.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Another area of low pressure will track from the Great Lakes into
the Ohio Valley. A warm front extending out from that system will
lift towards southwest portions of the forecast area Tuesday night.
Scattered showers and thunderstorms will develop in the evening and
then become likely for most of the region after midnight Tuesday
night and into Wednesday morning as that warm front lifts through
the region. Precipitation tapers off by midday Wednesday, and then a
warm and humid airmass will be in place. Highs top off in the mid to
upper 80s, except for the low 80s in the southern Poconos and
northern New Jersey, and in the 70s along the coasts. Surface dew
points will be in the upper 50s to low 60s in the afternoon.

Low pressure approaches from the west Wednesday night, and scattered
showers and isolated thunderstorms will move into portions of
southeast Pennsylvania and Delmarva late Wednesday night. As the
main surface low tracks towards western New York and
Pennsylvania, a secondary low will develop out ahead of this
primary low, resulting in more widespread showers with
scattered thunderstorms moving into the region Thursday
afternoon and evening as a warm front lifts north of the region.
Global guidance has indicated some instability as the warm
front lifts north, suggesting the potential for some strong to
severe thunderstorms south of the warm front during the
afternoon, but exactly how far north the warm front progresses
will greatly determine the coverage of any strong to severe
storms in our forecast area. At the moment, it remains too
uncertain to mention anything more specific at this time. Even
the afternoon high temperatures will be highly variant on where
the warm front ends up, with low to mid 60s north of the front
and mid to upper 70s south. Showers and storms will taper off
Thursday night as the storm system shifts offshore.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A cold front will push through the region Friday afternoon and
evening. Yet another round of scattered showers and isolated
thunderstorms will affect the area during that time.

Behind the cold front, surface high pressure builds east.
Several weak disturbances may touch off some afternoon showers
on Saturday and Sunday.

Highs will then be in the 60s for southeast Pennsylvania and
New Jersey and in the low to mid 70s in Delmarva on Friday.
Below normal highs expected for Saturday and Sunday, generally
in the low to mid 60s.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of Tonight...MVFR/IFR conditions at the Lehigh Valley and
I-95 terminals. Should be more of VSBY restrictions at KABE/KRDG
as a cold front slowly slides through, with stratus and patchy
fog developing at the I-95 terminals. Conditions drop to LIFR at
KACY/KMIV where the fog will be more widespread and some marine
stratus moves onshore. Winds generally light and variable, 3 kt
or less. Moderate confidence overall.

Tuesday...Conditions quickly lift to VFR with fog mixing out and
any lingering low ceilings lifting. All terminals outside of
KMIV/KACY should be back to VFR by the late morning (12z-14z or
so). Lower visibilities and ceilings persist at KMIV/KACY
through midday or so, though expecting VFR for the afternoon.
Very light flow out of the north/northeast in the morning will
shift to a more southwesterly flow in the afternoon. Wind speeds
5 kt or less. Moderate confidence overall.

Tuesday Night...MVFR/IFR conditions redeveloping with low clouds
and patchy fog. Southerly winds 5 kt or less. Low confidence in
timing and extent of restrictions.

Outlook...

Wednesday through Saturday...Sub-VFR conditions at night in fog
and stratus, while VFR conditions overall during the day.
Chances for SHRA/TSRA throughout the period with sub-VFR
conditions. More widespread SHRA with scattered TSRA Thursday
afternoon and evening.

&&

.MARINE...
Tonight through Tuesday...The conditions are expected to remain
below Small Craft Advisory criteria. Some fog, possibly dense,
improving during Tuesday.

Outlook...

Tuesday night through Saturday...Overall, sub-SCA conditions
through the period. Scattered showers and thunderstorms will
result in locally higher wind gusts and seas, with biggest
impacts coming on Thursday afternoon and evening.

&&

.TIDES/COASTAL FLOODING...
Tidal ranges increasing this week as the new moon arrives Tuesday
evening. Limited onshore flow means that there won`t be much in
the way of serious flooding concerns, but still minor tidal
flooding is possible beginning tomorrow evening and perhaps
Wed/Thu evening as well. A Coastal Flood Advisory may be issued
overnight if trends remain.

&&

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

&&

$$

SYNOPSIS...MJL
NEAR TERM...Gorse/Hoeflich/Kruzdlo
SHORT TERM...MJL/MPS
LONG TERM...MJL/MPS
AVIATION...Gorse/Hoeflich/Kruzdlo/MJL
MARINE...Gorse/Hoeflich/Kruzdlo/MJL
TIDES/COASTAL FLOODING...NWS PHI