982
FXUS61 KPHI 070141
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
941 PM EDT Tue May 6 2025

.SYNOPSIS...
An upper level low will slowly move across the Northeast and Mid-
Atlantic regions tonight, then it will lift out of the region on
Wednesday. A cold front will cross our area Wednesday night and
Thursday morning. Another upper level low develops across the
Northeast and Mid-Atlantic regions Thursday night and Friday with
weak low pressure nearby, before shifting northeast on Saturday. A
cold front may then move through during Sunday with high pressure
returning by early next week.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
A closed H5 low remains centered over western New York and
western Pennsylvania. This system will lift to the northeast and
will be over the border of northern New York state, northern
Vermont, and southern portions of the Province of Quebec. Strong
shortwave energy will pass through the region during the
overnight hours, and this may trigger a few showers across the
region with minimal QPF. Most of the showers will be north and
west of the I-95 corridor. Cloud cover may tend to fill back in
again through the night as the mixing wanes and the main core of
the closed low arrives. Overall though, dew points will come
down some across the entire region through the overnight as some
drier arrives on the south side of the closed low.

As we go through Wednesday, the closed low continues to depart
our area and the cyclonic flow weakens. While a few showers
cannot be ruled out especially through midday, they look to be
spotty given enough drying arriving in the wake of the closed
low. This should also result in more sunshine through the day
along with a west or west-southwest breeze. High temperatures
are forecast to be in the 70s across much of the area, although
cooler along the coast as the winds should be light enough to
result in a more southerly wind component.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
By Wednesday night, the upper low will have departed the region
where a brief period of zonal flow orients itself over the area.
However, this will be short-lived as another upper level trough
begins to pivot into the region on Thursday. This feature is also
expected to close off in nature, just like its predecessor as it
pivots over the Northeast through Friday, before lifting out of the
region by Friday night.

As a result, we`ll have partly to mostly cloudy skies in place for
Wednesday night with lows in mostly in the 50s and light winds.
Clouds will continue to increase on Thursday, especially during the
afternoon as a round of showers and thunderstorms are expected to
develop across the region and linger into the early evening hours.
Considering the placement of the upper low and the abundance of
cloud cover expected, it is not too certain on how much we may
destabilize during the afternoon. High temperatures will be in the
upper 60s to upper 70 across much of the area regardless. For now,
the severe potential appears to be low, but a few thunderstorms are
certainly plausible at times time. Showers will likely continue into
Thursday night, but with the loss of diurnal heating, any activity
should generally be showery in nature. Lows on Thursday night will
remain quite seasonable in the 40s and 50s.

By Friday, the closed low will settle near/over New York State, with
surface low pressure developing either over or just off the coast of
New Jersey. Showers will continue to develop throughout the course
of the day with a few embedded rumbles of thunder possible as well.
High temperatures will be noticeably cooler than those on Thursday,
as highs on Friday will only be in the upper 50s to upper 60s.
Overall, a damp day is expected to close out the week. The surface
low will depart by Friday night as the upper level low exits the
region. The shower activity will then cease from southwest to
northeast as the low departs. Lows on Friday night will generally be
in the 40s to around 50 degrees with skies improving from mostly to
partly cloudy.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
For Saturday through Monday...A rather benign weather period is
expected to occur for the weekend into early next week with dry
conditions (PoPs less than 10%) and gradually warming temperatures.
Mostly sunny skies during the day and mostly clear skies at night
are expected through the period. Highs in the upper 60s to low 70s
on Saturday will gradually warm low to mid 70s on Sunday and into
the mid to upper 70s by Monday.

For Monday night into Tuesday...A deep closed low over the Gulf
Coast will begin to migrate northeastward into the Tennessee Valley
by mid week. At the surface, an area of low pressure will be making
its way northward over the Carolinas into the Mid-Atlantic states on
Tuesday. This will allow a chance of showers to be introduced into
the southern portions of the forecast area beginning Monday night
and a slight chance of showers into the remainder of the forecast
area on Tuesday. Temperatures are expected to be around 5 degrees
above normal for mid-May.

&&

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

Tonight...There may be scattered SHRA after 04Z, but a VFR
forecast overall. If a heavier SHRA passes over any given
terminal, there may be brief restrictions as low as MVFR. Since
confidence is low in that occurring, will carry a VFR forecast
with VCSH. W-SW winds 5 to 7 kt.

Wednesday...VFR. A few SHRA are possible during the day, but not
expecting sub-VFR conditions. W winds 5 to 10 kt, though a sea
breeze may develop near KACY in the afternoon. Moderate
confidence overall.

Outlook...

Wednesday night...VFR. No significant weather expected.

Thursday through Friday...Sub-VFR conditions expected, especially
for Thursday night and Friday. Periods of rain showers likely with
isolated thunderstorms possible.

Friday night through Sunday...VFR expected. Other than a slight
chance of a shower on Friday night, no significant weather
anticipated.

&&

.MARINE...
Sub-Small Craft Advisory criteria on the waters through
Wednesday.

Outlook...

Wednesday night through Thursday night...No marine headlines
expected. Winds of 15 kt or less with seas around 2-4 feet. Fair
weather on Wednesday night with a chance for showers and isolated
thunderstorms on Thursday into Thursday night.

Friday through Friday night...SCA conditions possible mainly due to
seas. Winds of 10-20 kt with seas around 3-5 feet. Periods of rain
showers and isolated thunderstorms possible.

Saturday through Sunday...No marine headlines expected. Winds of 15
kt or less with seas around 2-4 feet. Fair weather.

&&

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

&&

$$

SYNOPSIS...DeSilva/MJL
NEAR TERM...Gorse/MPS
SHORT TERM...DeSilva/MJL
LONG TERM...DeSilva/MJL
AVIATION...DeSilva/Gorse/MPS
MARINE...DeSilva/Gorse/MPS