Allentown, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

633
FXUS61 KPHI 121023
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
623 AM EDT Thu Jun 12 2025

.SYNOPSIS...
Bermuda high will remain in place offshore, with weaker high
pressure over the Mid- Atlantic sliding offshore by Friday. A
weak cold front approaches from the northwest tonight and
becomes nearly stationary over the Mid- Atlantic into the
weekend. Several waves of low pressure will affect the area
starting late Friday and continuing into the new week, with
multiple rounds of showers and storms, and below normal
temperatures likely.

&&

.NEAR TERM /THROUGH TONIGHT/...
Some areas of fog have developed across southern Delaware and
adjacent areas of Maryland. This bank of fog could spread north
and impact coastal Cape May County as well before mixing out
later this morning. Otherwise, the forecast remains on track.

It appears that today will be the warmest of the stretch, with
most urban areas expected to reach the low 90s while mid/upper
80s will be found in other areas. For many areas, this could be
the first 90 degree day of the year. Dewpoints will trend
upward too, so hot and muggy today. We do expect a few scattered
tstms to develop across the North/Northwest areas and track
into Northern NJ. We`ll continue with the slight chance to low
chance pops that we had earlier. The SPC has indicated that a
Marginal risk for severe thunderstorms exists across these areas
today. Large hail and damaging wind threats are low but not
zero.

Tonight, any tstms/showers end during the evening then muggy
and mild overnight. Lows will only dropping to the mid/upper 60s
for S/E areas and upper 50s to low 60s N/W. A weak cold front
will slip southward across the area tonight. Clouds early then
decreasing sky cover late. Patchy fog where any rains fall.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
Weak high pressure across the region Friday morning moves
offshore Friday afternoon. A stationary front will be draped
over the Mid- Atlantic area, and low pressure slowly approaches
from the west late Friday on that boundary. The low passes
through Delmarva and southern New Jersey Saturday morning
through Saturday afternoon before departing.

A few showers and perhaps a thunderstorm may develop late
Friday afternoon as some shortwave energy approaches from the
west but the bulk of the activity hold off until Friday night
through Saturday morning with the passage of the low. Highest
instability will be focused on Delmarva, generally in the
vicinity of the low, but not expecting severe weather. Will
carry slight chance to chance for thunderstorms, mainly Friday
night.

After the low departs late Saturday morning, the stationary
front over the Mid-Atlantic lifts north as a warm front as low
pressure moves into the Great Lakes. Some shortwave energy ahead
of that low moves into the northern half of the forecast area.
With surface dew points rising through the 60s and approaching
70, another round of showers and thunderstorms is possible late
in the day. PoPs will mostly be chance, but PoPs will be likely
for portions of the southern Poconos and western Lehigh Valley.
The threat for severe weather is minimal, but with increasing
dew points and PWATs over 1.5 inches for most of the area, and
over 2 inches for Delmarva, locally heavy rain is a threat.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Low pressure approaches from the west and slowly works its way
through the Mid-Atlantic and Delmarva Sunday through Monday. A
prolonged period of unsettled weather is on tap during this time
with showers and isolated to scattered thunderstorms. Given
abundant low level moisture with surface dew points well in the
60s, locally heavy rain will develop from time to time. WPC has
a Marginal Risk (1 out of 4) for excessive rain Saturday night
through Sunday and again Sunday through Sunday night. Rain
tapers off on Monday as low pressure departs. With a prolonged
period of onshore flow, temperatures will be on the cool side
through the weekend and into Monday with highs on Sunday in the
low to mid 70s and highs on Monday in the upper 60s to low 70s.

Several additional shortwaves approach from the west as the
week progresses, and weak waves of low pressure will develop as
a result. This will keep low chance PoPs in the forecast through
Wednesday. Temperatures will rebound somewhat on Tuesday before
warming back into the 80s on Wednesday. After multiple cloudy
days, a return of sunshine should be anticipated on Wednesday as
well.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...VFR with high clouds expected. Light winds becoming
West around 10 knots after 13Z. A few showers/tstms possible for
the late afternoon across NE PA or North NJ. Kept the VCSH in
the KABE TAF for this. High confid.

Tonight...VFR expected. Winds mostly light and variable, but
turning North or Northeast for most sites after 02Z/03Z. High
confid overall.

Outlook...

Friday...VFR initially, then scattered afternoon SHRA develop
with brief sub-VFR conds possible, mainly west of the I-95
terminals.

Friday night through Saturday...Prevailing MVFR to IFR likely,
mainly from low ceilings. SHRA and scattered TSRA. A break in
SHRA possible around midday Saturday before ramping up again
Saturday afternoon.

Saturday night through Monday...Prevailing MVFR to IFR likely,
mainly from low ceilings. SHRA and scattered TSRA.

&&

.MARINE...
An area of dense fog has developed and spread north along
coastal Delaware and offshore of southern New Jersey. Visibility
could be reduced to 1 NM or less at times in this area, which
may continue spreading northward some before visibility improves
later today. A Dense Fog Advisory was issued to highlight this
threat through noon.

Otherwise, high pressure offshore and a cold front approaching
from the North/Northwest later today and tonight. Winds will
remain below SCA levels as winds come in from the West/Southwest
today and early tonight. After that, winds across the northern
waters will turn North/Northeast into the evening and this wins
shift will trend southward thru the night. Fair weather overall,
but a stray shower across the far northern waters possible this
evening. Low confid regarding shower activity.

Outlook...

Friday through Monday...Overall, sub-SCA conditions expected,
though there is the potential for SCA conditions Sunday night
through Monday. VSBY restrictions in showers, drizzle, and
isolated to scattered thunderstorms throughout this period.
Areas of fog also possible.

Rip Currents...

For today, southwest winds around 5-10 mph turning south in the
afternoon behind a sea breeze. Breaking wave heights of 1-3
feet with a weak southeasterly swell of 1 foot around 9 seconds.
We will be about 36 hours removed from the Full Moon from
early Wednesday morning, therefore expecting to see less of an
impact to tides as a result. We have a LOW risk for dangerous
rip currents at all beaches.

For Friday, east-northeast winds around 5-10 mph turn more
easterly in the afternoon. Breaking wave heights remain around
1-3 feet with a weak southeasterly swell of 1 foot around 9
seconds. No major differences from Thursday, so we will maintain
a LOW risk for dangerous rip currents at all beaches.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Dense Fog Advisory until noon EDT today for ANZ431-453>455.

&&

$$

SYNOPSIS...MPS/Staarmann
NEAR TERM...OHara/Staarmann
SHORT TERM...MPS/Staarmann
LONG TERM...MPS/Staarmann
AVIATION...MPS/OHara/Staarmann
MARINE...MPS/OHara/Staarmann