Lewes, Delaware 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

039
FXUS61 KPHI 141740
AFDPHI

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

.WHAT HAS CHANGED...
Updated Aviation section for 18Z TAFs.

&&

.KEY MESSAGES...
1. Scattered severe thunderstorms are likely late this
afternoon into this evening.

2. Widespread minor coastal flooding continues with the evening
high tide cycles tonight along the Atlantic coast and Delaware
Bay. A new Coastal Flood Advisory was issued for tonight`s high
tide.

3. Some severe thunderstorms possible Thursday afternoon and evening.

&&

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

For today, 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 this
evening. There is also indications of a pre-frontal trough as
well. The low to mid level flow will increase some in response
to these features, which will increase both the warm air and
low-level moisture advection.

At this point we are still fairly confident that showers and
thunderstorms will be around portions of the area late this
afternoon and evening. As stronger synoptic forcing arrives,
guidance continues to indicate bulk shear values in excess of 40
kt, which will aid storm organization. Looking at other
parameters, MLCAPE in the area should max out around 1000-1500
J/kg with decent low-level shear around 25-30 kt. Low-level
lapse rates will be in excess of 8 C/km, DCAPE will top out near
1000 J/kg, and PWATs will be near 1.8 inches, which support wet
microbursts, indicating that damaging winds gusts are likely
with any storms. Additionally, some guidance has continued to
depict a localized corridor of backed surface winds, primarily
over southwestern portions of the area, so an isolated tornado
cannot be ruled out. One fly in the ointment though, is some
forecast soundings (more notably the NAM) indicate an area of
mid-level warming between 700-850 mb, which may keep the area
largely capped through the afternoon. In fact the trend has been
for a slightly later timing for the convection.

Given that there will likely be a prefrontal trough ahead of the
main cold front, convection could start to fire along the trough
as early as the 21-23z timeframe over Delmarva into portions of
SE PA and adjacent portions of southern NJ. This initial round
of convection would tend to favor clusters of storms with the
potential for some embedded supercells. Storm motion will be to
the northeast with the main uncertainty being the magnitude and
coverage. Following this initial round, another round of storms
will be possible by later in the evening into the early part of
the overnight along and just ahead of the cold front. This
second round would favor a more linear configuration. A forecast
challenge continues to be that the instability should be a bit
higher with the initial round but the forcing won`t be as strong
and this could be a limiting factor along with the warm layer
aloft noted above. Stronger forcing will arrive with the cold
front later in the evening however instability could be more
limited by this time. For these reasons, the Storm Prediction
Center is maintaining the SLIGHT risk (level 2/5). Finally,
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 AM Monday though the severe threat will be decreasing
by around midnight.


KEY MESSAGE 2...Widespread minor coastal flooding continues with
the evening high tide cycles tonight along the Atlantic coast
and Delaware Bay. A new Coastal Flood Advisory was issued for
tonight`s high tide.

Minor tidal flooding was observed on Saturday Night as a New
Moon this weekend is 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 new Coastal Flood Advisory was
issued for this evening for the same area it was last night
(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. 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 during Thursday. This will also drive
deepening surface low pressure up 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 streak is forecast to extend eastward from
the eastern Great Lakes, with 40-70 knots of flow at 500 mb forecast
across our area Thursday afternoon. This increased flow will result
in greater shear magnitudes. While there are 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 is some severe
thunderstorm potential Thursday afternoon and evening. As of now,
damaging winds may be 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. The details are much less certain at this time range
though given the typical uncertainty with instability and the
thermodynamic profiles. The forecast synoptic setup however with a
deepening surface low tracking well to our northwest with stronger
flow within a warmer and more moist environment suggests some risk
for severe thunderstorms. Finally, it`s possible the front ends
up being slow moving which could result in showers/storms
lingering into Friday (though there should be a lower threat of
severe weather by Friday).

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of Today...VFR with increasing clouds. Outside of stray
shower, any convective activity is expected to occur tonight
(see below). South-southwest winds around 10-15 kt gusting up to
20-25 kt. High confidence.

Tonight...Prevailing VFR to start the night. Showers and
thunderstorms are likely to move into the area around 23-02Z
for western areas, and 02-05Z 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...

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.

&&

.MARINE...
Small Craft Advisories remain in effect for the Atlantic
Coastal Waters from Sandy Hook NJ to Cape Henlopen DE from 1 PM
this afternoon to 12 AM Monday. Small Craft Advisories have
also been issued for the Delaware Bay from 1 PM to 8 PM today.

Southwest winds around 10-15 kt and seas of 2 feet or less are
expected to continue through this morning. By this afternoon
and into this evening, southerly winds are expected to increase
to around 15-20 kt with gusts up to 25 kt. Seas build from 2-4,
potentially up to 5 feet. Scattered thunderstorms possible
this evening.

Outlook...

Monday 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.

Rip Currents...

For today, winds become southerly and increase to 10-15 MPH
with some higher gusts. However, a medium period swell around
6-8 seconds will continue along with breaking waves once again 2
feet or less for most beaches. The exception will be at
southern facing beaches in Cape May and Atlantic counties where
breaking waves in the surf zone will be up to 3 feet as the
winds will be most directly onshore here. Therefore, the risk
for the development of dangerous rip currents will be higher for
these beaches, and a MODERATE risk is currently forecast for
these two counties. For the remainder of the Jersey Shore and
the Delaware Beaches, a LOW risk for the development of
dangerous rip currents is forecast.

For Monday, winds become northwest 10-15 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 all beaches.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory from 7 PM this evening to 1 AM EDT
     Monday for NJZ012>014-020>027.
DE...Coastal Flood Advisory from 7 PM this evening to 1 AM EDT
     Monday for DEZ002>004.
MD...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ430-
     431.
     Small Craft Advisory until midnight EDT tonight for ANZ450>454.

&&

$$

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