515
FXUS61 KPHI 160801
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
401 AM EDT Mon Jun 16 2025

.SYNOPSIS...
Low pressure tracks on a stationary boundary over the Mid-
Atlantic through this morning. The stationary boundary lifts
north as a warm front Tuesday through Tuesday night. Bermuda
high pressure sets up offshore Wednesday and Thursday. A regime
change occurs towards the end of the week as a cold front
passes through the region Thursday afternoon and night. High
pressure returns for Friday and Saturday, possibly followed by a
cold front on Sunday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Dreary conditions and showery weather with periods of
mist/drizzle will continue through the day as the stalled
boundary continues to be the trigger for weak showers. Relative
humidities in the 0-2km layer remains above 90% and light WAA in
the 1000-850mb layer there`s enough lift and moisture to see
areas of light rain/drizzle throughout the morning and into the
afternoon. Its by no means a washout, but I`d anticipate most of
the area should see at least some light rain. With PWATs in the
1.25-1.75" range and warm cloud depths in the 12-13kft range,
rainfall could end up being heavy at times even though overall
accumulation numbers should be small.

Temps this afternoon topping out in the mid 60s to mid 70s under
widespread cloud cover.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
Unsettled weather continues through Wednesday. Weak low
pressure starts to approach from the west this evening, and
will start to lift the stationary boundary located south of the
region back north as a warm front. The front should be slow to
move through the region and will likely not reach the area
until late Tuesday. Again, with modest WAA and sufficient low
level moisture, we`ll see mostly cloudy skies with occasional
showers from time to time, with one shot coming late Monday
night through Tuesday morning, and then another shot Tuesday
night into Wednesday morning. Highs on Tuesday will be a bit
warmer owing to the light WAA, generally in the low to mid 70s
north of the Fall Line and in the upper 70s south of the Fall
Line.

With the warm front north of the area on Wednesday, warm air
advection will be underway, and highs will be in the mid to
upper 80s throughout and low 90s towards the Pines and DelMarVa.
Several shortwaves will pass through the region, keeping
scattered showers and thunderstorms in the forecast throughout
the day.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The pattern finally looks to change for the end of this week
and into the weekend. Bermuda high pressure sets up offshore and
strong WAA will result in a hot and increasingly humid airmass
into the region on Thursday. Highs will be in the low 90s
throughout, and surface dew points will be in the low 70s. Max
Heat Index values will be in the upper 90s throughout, and Heat
Advisories may be needed. The NWS HeatRisk categories are
forecast to be between level 2 to level 3 indicating that the
early season heat will likely affect anyone without effective
cooling or adequate hydration.

The second impact from Thursday will be the convection
associated with a strong cold front passing through the region
late Thursday and Thursday night. This will spark off afternoon
and evening showers and thunderstorms, some of which may be
strong to severe. The Storm Prediction Center has a 15% risk for
severe weather across portions of the Northeast and Mid-
Atlantic on Thursday.

From there, conditions become settled into the weekend as high
pressure builds in from the north and west. An upper trough
passing through the region on Friday may touch off some showers
across northern zones, but the majority of the area should stay
dry with highs in the low to mid 80s and lower dew points. Sunny
and warm conditions continue into Saturday.

Another cold front may result in scattered showers and
thunderstorms on Sunday.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through 12z...MVFR/IFR expected through the night trending
towards IFR by daybreak. Light rain may briefly pass through
producing MVFR visibilities along with IFR cigs. Cannot rule
out some patchy fog and lower visibility, but guidance has lower
chances of reduced visibility compared to the previous few
nights. East- northeast winds around 3-8 kt. Moderate confidence
overall.

Monday...IFR conditions to continue for most of Monday with
little improvements. Have introduced Prob30`s to cover the
threat of the light rain showers through the middle portion of
the day. East- northeast winds around 10 kt. MVFR VSBYs
expected in any drizzle. Low- moderate confidence.

Outlook...

Monday night through Tuesday night...Sub-VFR CIGs/VSBYs in fog,
stratus, and scattered SHRA.

Wednesday through Wednesday night...VFR. Scattered TSRA
possible with brief sub-VFR conditions, mainly in the afternoon
and evening.

Thursday through Thursday night...VFR. Scattered afternoon and
evening SHRA/TSRA with brief sub-VFR conditions.

Friday...VFR.

&&

.MARINE...
No marine headlines are in effect through Monday. East-
northeast winds around 10-15 kt with occasional gusts up to
18-20 kt. Seas of 3-4 feet. Periods of showers, drizzle, and
mist expected to continue through Monday.

Outlook...

Monday night through Friday...Sub-SCA conditions expected
through the week with max wind gusts below 20 kt and seas in the
2 to 4 ft range. VSBY restrictions in showers and fog through
Tuesday night. Afternoon and evening showers and thunderstorms
possible on Wednesday and Thursday with locally stronger winds
and higher waves.

Rip Currents...

For Monday, winds will be out of the northeast and nearly
perpendicular to shore around 10-20 MPH, with 2 to 4 foot waves
within the surf zone. Multiple swell groups are expected as
well, with the longest period being around 8 to 9 seconds. This
will result in a MODERATE risk for the development of rip
currents for all beaches.

For Tuesday, winds turn to be a bit more east-southeasterly and
decrease to around 10 MPH. Swell remains onshore but the number
of swell groups look to consolidate with the period decreasing
to 6-7 seconds. Breaking waves in the surf zone look to decrease
to 2-3 feet as a result. The combination of these factors look
to lead to a decreasing risk for the development of rip
currents, so at this time a LOW risk is forecast for the beaches
south of Atlantic City and MODERATE for the northern Jersey
Shore beaches.

For specific beach forecasts, visit weather.gov/beach/phi

&&

.TIDES/COASTAL FLOODING...
With onshore flow continuing over multiple tide cycles, water
will pile up within back bays and inlets. This will result in
some spotty minor tidal flooding along the Atlantic coastline
for areas in Atlantic and Cape May County, New Jersey and Sussex
County in Delaware. Cannot rule out some spotty minor tidal
flooding within the Delaware Bay and tidal Delaware River. The
overnight high tide cycle tonight looks to bring the highest
tides, with slowing declining water levels getting into this
week.

&&

.CLIMATE...
Georgetown and Wilmington set record low maximum temperatures
today. Please see the Record Event Reports for more information.

&&

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

&&

$$

SYNOPSIS...Deal/MPS
NEAR TERM...Deal/DeSilva
SHORT TERM...Deal/MPS
LONG TERM...Deal/MPS
AVIATION...Deal/DeSilva/Hoeflich/MPS
MARINE...AKL/Deal/DeSilva/MPS
TIDES/COASTAL FLOODING...
CLIMATE...