Special Marine Warning 52, NWS Philadelphia/Mount Holly

Area Forecast Discussion
National Weather Service Mount Holly NJ
821 PM EDT Sun Jun 14 2026

.WHAT HAS CHANGED...
Updates for Aviation and Marine sections.

&&

.KEY MESSAGES...
1. Scattered severe thunderstorms are likely this evening.

2. Widespread minor coastal flooding continues with the evening
high tide cycles tonight along the Atlantic coast and Delaware
Bay. A Coastal Flood Advisory remains in effect for tonight's
high tide.

3. Some severe thunderstorms possible Thursday afternoon and evening.

&&

.DISCUSSION...
KEY MESSAGE 1...Scattered severe thunderstorms are likely this evening.

Severe thunderstorm Watch up for many parts of the area through
1AM.

An expansive upper-level trough across much of eastern Canada
will gradually shift eastward. Some stronger shortwave energy
within the southern portion of the trough will slide across our
area. At the surface, a cold front will be tied to this feature,
which is forecast to cross through overnight.

Showers and thunderstorms have developed to the west/southwest
of our area and are now beginning to affect Berks County PA and
the southern Poconos. Another area of tstms will approach our Delmarva
area shortly. Warnings are probable with the threat of damaging
winds the greatest concern. Also, given that PWATs are abnormally
high, we also cannot rule out some localized flash flooding, especially
near/over the urban corridor. The limiting factor, however, will
be rapid storm motion.

The cold front and associated convection should be largely out of
the area by 2-4 AM Monday though the severe threat will be decreasing
by around 1 AM.

KEY MESSAGE 2...Widespread minor coastal flooding continues with
the evening high tide cycles tonight along the Atlantic coast and
Delaware Bay. A Coastal Flood Advisory remains in effect for tonight's
high tide.

A New Moon is occurring this weekend and resulting in higher than
normal astronomical tides. Further rounds of tidal flooding are
expected with the evening/nighttime high tide cycles tonight and
potentially Monday for the Atlantic Coast and Delaware Bay.

The tidal Delaware River and its tributaries could experience some
spotty minor tidal flooding (non-advisory) with tonight's high tide
but generally these astronomical tide driven flooding events produce
more noteworthy impacts for the Atlantic coasts and Delaware Bay.
The highest of the New Moon tides will be tonight and Monday night.
A Coastal Flood Advisory remains in effect for this evening (Jersey
Shore/Delaware Beaches/Delaware Bay Communities/Middlesex County for
the Raritan Bay).

Tidal flooding is not currently expected along the eastern shore of
Chesapeake Bay.

KEY MESSAGE 3...Some severe thunderstorms possible Thursday afternoon
and evening.

An upper-level trough centered over south-central Canada is forecast
to strengthen eastward and also southward across the Great Lakes to
end the week. A strong shortwave rounding the base of this trough
may result in a portion of it taking on a negative tilt across the
eastern Great Lakes and toward New England late Wednesday and Thursday.
This feature is a bit stronger in the ECMWF solution, while the
GFS ensembles are mostly a little weaker. A deepening surface low
will accompany it and track across the eastern Great Lakes and into
adjacent Canada during Thursday. A strong cold front will then arrive
into our area Thursday afternoon or Thursday evening.

As the synoptic pattern evolves, the flow will increase out of the
south and southwest. This will advect deeper moisture northward, and
in tandem with strengthening warm air advection will lead to
increased instability during the day Thursday. In addition, a strong
mid to upper level jet is forecast to extend eastward from the
eastern Great Lakes. While the core of the 500 mb jet (80-100 knots)
is forecast to remain mainly northwest of our area, 40-70 knots of
flow at 500 mb is still forecast across our area Thursday afternoon
into the evening. This increased flow will result in greater shear
magnitudes. While there remains some timing differences among the
guidance regarding the main features, the consensus is that enough
instability should overlap with the stronger shear along with
incoming stronger forcing. As a result, there continues to be some
severe thunderstorm potential Thursday afternoon and evening. As of
now, locally damaging winds are the primary threat especially if
convection develops into a squall line. However if shear and
instability ends up being even greater, than all severe thunderstorm
hazards may come into play especially if the mode is discrete for a
time. The details remain much less certain at this time range given
the typical uncertainty with instability and the thermodynamic
profiles. The forecast synoptic setup however with a deepening
surface low tracking to our northwest with strong flow within a
warmer and more moist environment suggests some risk for severe
thunderstorms. In addition, the main trough may end up arriving on
Friday with some additional chances for showers and some
thunderstorms.

The I-95 corridor and the coastal plain (away from the immediate
coast) looks to be the hottest during Thursday ahead of the
convection, with the heat indices potentially getting very close to
100 degrees.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...Prevailing VFR to start the night. Showers and thunderstorms
are likely to move into the area around 01-04Z for western areas,
and 03-06Z for eastern areas. Expect brief periods of MVR/IFR conditions
with storms with a lingering period of some showers and MVFR conditions
in wake of the storms. Improvement expected by 06-09Z. Southerly
winds around 5-10 kt tonight, becoming northwesterly around 10-15
kt in wake of the front. Winds associated with evening convection
could briefly gust to 40+ knots. Moderate confidence as a whole.

Monday...VFR with a few/scattered clouds in the afternoon. Northwest
winds around 10-15 kt, occasionally gusting up to 20 kt. High confidence.

Outlook...

Monday night...VFR. Northwest winds quickly diminish and becoming
light and variable.

Tuesday...Mainly VFR.

Wednesday...Some sub-VFR conditions with a few showers or a
thunderstorm possible.

Thursday...A period of sub-VFR conditions probable in the afternoon
and evening as showers and some thunderstorms increase.

Friday...Some showers and thunderstorms may linger with areas of sub-
VFR conditions possible at times.

&&

.MARINE...
Small Craft Advisories remain in effect for the Atlantic Coastal
Waters from Sandy Hook NJ to Cape Henlopen DE through midnight
tonight. Small Craft Advisories on the Delaware Bay were
extended until Midnight too as winds remain up ahead of the
approaching front.

Southerly winds this afternoon are expected to increase to around 15-
20 kt with gusts up to 25 kt. Winds will diminish overnight as winds
turn northwesterly behind a cold front. Northwest winds will generally
remain around 15-20 kt through Monday morning, however a few rogue
gusts up to 22-23 kt are possible before further diminishing throughout
the day. Seas generally around 2-4 feet, locally 5 feet tonight, and
around 2-3 feet on Monday.

Showers and thunderstorms are likely through tonight, which may
cause localized higher winds/seas. Some marine fog possible tonight
as well. On Monday, fair weather expected.

Outlook...

Monday night through Wednesday...The conditions are anticipated to
be below Small Craft Advisory criteria.

Thursday...A period of Small Craft Advisory conditions probable.
Southerly wind gusts could near gale force for a time later Thursday.
Some gusty thunderstorms late in the afternoon and evening possible.

Friday...The conditions are anticipated to be below Small Craft
Advisory criteria.

Rip Currents...

For Monday, winds become northwest 10-20 mph with a continued
medium southerly swell of 6-7 seconds. With breaking waves 2
feet or less, have gone with a LOW risk for the development of
dangerous rip currents at all beaches.

For Tuesday, winds start northerly before shifting southeasterly,
but only at around 5 mph with a continued medium southerly
swell of 6-7 seconds. With breaking waves 2 feet or less, have
gone with a LOW risk for the development of dangerous rip
currents at all beaches.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory until 1 AM EDT Monday for NJZ012>014-
     020>027.
DE...Coastal Flood Advisory until 1 AM EDT Monday for DEZ002>004.
MD...None.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ430-431-
     450>454.

&&

DISCUSSION...DeSilva/Gorse/Hoeflich/po
AVIATION...DeSilva/Gorse/po
MARINE...Fitzsimmons/Gorse/po

Hazardous Weather Outlook
National Weather Service Mount Holly NJ
347 AM EDT Sun Jun 14 2026

MDZ012-015-019-020-150915-
Kent MD-Queen Annes-Talbot-Caroline-
347 AM EDT Sun Jun 14 2026

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Today and tonight.

There is a SLIGHT Risk (level 2 out of 5) of severe thunderstorms
late this afternoon into this evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

There is a low probability for widespread hazardous weather.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.