Preston, Maryland Weather Forecast Discussion

463
FXUS61 KPHI 291842
AFDPHI
Area Forecast Discussion
National Weather Service Mount Holly NJ
242 PM EDT Mon Sep 29 2025
.SYNOPSIS...
High pressure is in control through Tuesday. A strong but
moisture-starved cold front moves through on Tuesday night
before an expansive area of high pressure moves in for the rest
of the week and the upcoming weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
Very large shield of high clouds has spread north of Imelda, but
otherwise, impacts for land areas are expected to be minimal
before it turns east and out-to-sea on Tuesday. Otherwise, weak
high pressure will remain in control through Tuesday, keeping it
warm and humid by late September standards. A few showers may
creep their way into parts of the Delmarva, most likely this
evening, but overall dry weather should prevail with a
relatively light northeast wind of 5-10 mph. Near the coastal
waters, this wind may become closer to 10-20 mph by later in the
day Tuesday. Lows tonight will be in the mid 50s to mid 60s,
warmest south/coast/urban areas, while highs Tuesday will be in
the mid 70s to low 80s, warmest eastern PA and central/northern
NJ where there should be a little more sun and a bit less marine
influence.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Initially, a fairly complex upper-pattern will be in place
across the region as we find ourselves between a ridge to the
west over the Missouri Valley and Great Lakes regions, Humberto
and Imelda to the southeast over the open Atlantic, and the
polar jet across portions of northern New England. With time,
the ridge will expand eastward, eventually encompassing our area
on Thursday, as the other features continue to track away. At
the surface, a cold front will track southward through the
region Tuesday night, with strong high pressure building in from
the north.
With sufficient moisture in place and easterly flow, widespread
cloud cover is expected Tuesday night ahead of the cold front.
No precipitation is expected, however, and clouds should clear
from north to south with the frontal passage. Lows Tuesday night
look to be in the mid-upper 40s across the higher elevations of
eastern PA and far northern NJ, the low 50s across the
remainder of eastern PA and inland NJ, and in the upper 50s to
near 60 along the coast and in the Delmarva. Wednesday should
feature mostly clear skies with highs ranging from the upper 60s
to low 70s. Wednesday night will feel like fall, with
temperatures falling deep into the 40s across eastern PA and
northern NJ, and the upper 40s to near 50 elsewhere. The cooler
trend will continue on Thursday, with highs likely struggling to
climb out of the 60s across the entire area.
Aside from fair weather and cooler temperatures behind a cold
front, our area will be between the pair of tropical cyclones to
our southeast and strong high pressure building in from the
north. This setup will favor gusty winds along the coastal
strip. The gustiest period looks to be Tuesday night into
Wednesday, with gusts in the 30-40 mph range. As of right now,
it appears winds will fall short of wind advisory criteria, but
this is something that will need to be watched the next few
forecast cycles in case there is any upward trend to forecasted
winds.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
There will likely be very little change to the upper-pattern
through the extended period, with ridging remaining situated
over the eastern tier of the US. At the surface, high pressure
will remain centered over portions of the Mid-Atlantic and
northeast.
Tranquil weather is expected from Thursday night through
Monday, with skies ranging from partly to mostly clear.
Temperatures will remain below average Thursday night through
Friday night, though slowly moderating with time. By Saturday,
temperatures are expected to be mostly seasonable across the
area. Sunday into Monday look to continue the slow moderating
trend, with temperatures getting back to being slightly above
normal.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...
Generally VFR conditions expected through Tuesday, with east-
northeast winds up to 10 kts today shifting north-northeast
later tonight and Tuesday. The exception will be KACY, where an
MVFR cig has (likely briefly) moved into the terminal and may
linger through the rest of this afternoon. There may also be a
little mist there overnight tonight, though confidence on that
is low. Moderate to high confidence overall otherwise.
Outlook...
Tuesday night through Wednesday...VFR. Wind gusts could
approach 30 kt for KMIV and KACY.
Wednesday night through Saturday...VFR. No significant weather.
&&
.MARINE...
Small Craft Advisory goes into effect this evening on the ocean
waters as seas start to build thanks to the influence of
Hurricane Humberto and Tropical Storm Imelda. While the SCA
continues as seas build further on Tuesday, winds should stay
below advisory levels through Tuesday. However, they will start
increasing notably towards day`s end.
Outlook...
Tuesday night through Wednesday...Confidence is increasing in a
period of gale force winds beginning Tuesday night and
continuing through much of the day Wednesday. Have issued a Gale
Warning for ocean zones south of Manasquan Inlet, where
frequent gusts of 35-40 kt are expected. Have maintained the SCA
north of Manasquan Inlet and for the Delaware Bay, where winds
are expected to peak in the 25- 30 kt range. Seas over the open
ocean could build to 7-11 feet.
Wednesday night through Thursday...SCA conditions are expected
to continue across all ocean zones, and at least the lower
Delaware Bay. While winds should decrease on Thursday, seas will
remain elevated, in the 5-7 foot range.
Thursday night...SCA conditions may linger on some waters,
primarily in the form of elevated seas.
Friday through Saturday...No marine headlines expected. Fair
weather.
Rip Currents...
For today, the increasing influence of longer period swells
around 13 to 16 seconds combined with there being multiple swell
groups along with northeast winds around 10 to 15 mph will
result in a MODERATE risk for the development of dangerous rip
currents at all beaches. Generally expect wave heights in the
surf zone to be around 2-3 feet.
For Tuesday, the long period swells associated with the
tropical systems to our south will continue to build and this
will result in a HIGH risk for the threat of dangerous rip
currents at all beaches. Generally expect rough surf conditions
as wave heights in the surf zone look to be around 3 to 6 feet.
Increasing onshore winds of 10-20+ MPH are expected. Issued a
Rip Current Statement for Tuesday.
For specific beach forecasts, visit weather.gov/beach/phi
The SRF product and rip current discussion will end on
September 30th.
&&
.TIDES/COASTAL FLOODING...
Strengthening northeast winds through later Tuesday into Wednesday
will lead to a piling up of water along the ocean front, back bays,
and the Delaware Bay. There is an increasing potential that this
will lead to widespread minor coastal flooding for these areas with
the Wednesday PM high tide cycle. For areas along the tidal Delaware
Bay, if any minor flooding occurs it will be very spotty. No tidal
flooding is expected along the Chesapeake Bay for our eastern MD
zones.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...High Risk for Rip Currents from Tuesday morning through Tuesday
     evening for NJZ014-024>026.
DE...High Risk for Rip Currents from Tuesday morning through Tuesday
     evening for DEZ004.
MD...None.
MARINE...Small Craft Advisory from 11 PM Tuesday to 6 PM EDT Wednesday
     for ANZ430.
     Small Craft Advisory from 6 PM Tuesday to 6 PM EDT Thursday
     for ANZ431.
     Small Craft Advisory from 8 PM this evening to 6 PM EDT
     Thursday for ANZ450.
     Small Craft Advisory from 8 PM this evening to 6 PM EDT
     Tuesday for ANZ451>455.
     Gale Warning from 6 PM Tuesday to 6 PM EDT Wednesday for
     ANZ451>455.
&&
$$
SYNOPSIS...Hoeflich/RCM
NEAR TERM...RCM
SHORT TERM...Cooper
LONG TERM...Cooper
AVIATION...Cooper/RCM
MARINE...Cooper/RCM
TIDES/COASTAL FLOODING...

NWS PHI Office Area Forecast Discussion