Dover, Delaware 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

113
FXUS61 KPHI 170717
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
317 AM EDT Sat May 17 2025

.SYNOPSIS...
Spotty showers, thunderstorms and warm weather persists through this
afternoon. A cold front will cross through the area later today
followed by a secondary cold front on Sunday night. High pressure
will return for Monday and Tuesday. Another dynamic weather system
will approach the region towards the middle of the week, bringing
another period of unsettled weather through the end of the week.

&&

.NEAR TERM /THROUGH SUNDAY/...
240 AM...As of early this morning, the area is once again in a bit
of a lull. However we still have at least one more round of some
convection to go through in association with the large area of
low pressure located to our west over the Great Lakes. In the
meantime, just some areas of low cloud cover, mist, and fog
around but it`s not nearly as widespread as this time last
night.

As we get towards dawn (4-6am), expect showers/storms currently over
portions of western PA into western MD to move through affecting
mainly Delmarva into adjacent southern NJ and perhaps extreme SE PA.
There`s been a general weakening trend with this convection but that
said, the shear and dynamics are quite impressive and there`s still
pretty good instability just off the deck with MU CAPES around 1000
j/kg. The low level wind field is also quite strong with SW winds at
850 mb around 40-45 knots. For this reason, these storms will be
capable of producing at least localized severe weather. Damaging
winds looks to be the biggest threat.

Once we get into the day Saturday, aformentioned storms will be
moving off the coast by around mid morning. After this time
we`ll have have an initial weak cold front (really more of a dry
line) moving through in the afternoon followed by a stronger
cold front in the evening. This will occur as surface low
pressure moves east from Ontario into Quebec while the
associated upper level low lumbers across the lower Great Lakes.
At this point though, any additional isolated to scattered
showers/storms PM looks to be more limited than earlier
thinking, especially in terms of the severe threat which was
downgraded to MARGINAL. Otherwise expect a mix of sun and clouds
with highs generally in the 80s and falling humidity levels in
the afternoon. It will also become fairly breezy with WSW winds
gusting 20 to 30 mph.

For Saturday night, both the surface and upper low pass by to our
north as they move into New England. Any left over showers/storms
diminish after sunset as drier air continues to move in and
also due to the loss of daytime heating. It will be cooler than
recent nights with lows generally ranging from the low to mid
50s north to the low 60s south.

Sunday is looking like the better half of the weekend as tranquil
weather returns with the upper trough moving farther east. Partly to
mostly cloudy skies are expected with dry conditions and low
humidity. Perhaps an isolated shower is possible north and west, but
general thinking is most of the area will stay dry. The one thing to
note is winds will increase as diurnal mixing occurs as the area
lies wedged between systems resulting in a tightening pressure
gradient. West wind gusts up 30-35 mph will be possible.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
The upper level low over the Northeast US will move east into the
North Atlantic on Monday. This will give way to northwest flow as a
subtle mid-level ridge moves into the Ohio Valley on Tuesday. At the
surface, a secondary cold front crosses through the region early
Sunday night with high pressure over Canada extending its ridging
southward through Tuesday.

All in all, a benign weather period is anticipated across the Mid-
Atlantic region through Tuesday. Mostly clear skies and dry weather
is expected. Winds will remain a bit breezy Sunday night into Monday
with gusts up to 30 mph as the pressure gradient remains modest in
combination with downsloping northwest flow. Lighter winds are
expected for Monday night and Tuesday. Highs will mostly be in the
70s on Monday with a mix of 60s/70s on Tuesday. Lows will be in the
40s/50s at night.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
By Tuesday night and through the middle of the week, our attention
turns to our next weather system which will take aim at the area. A
deep upper trough is expected to close off over the northern Great
Lakes region on Wednesday. This feature is then forecast to gain a
negative tilt as a vigorous piece of energy rounds the base of the
trough Wednesday night into Thursday. The upper low will then
meander over the Northeast US through Friday.

Global and ensemble guidance continues to develop an area of low
pressure at the surface over the Ohio Valley while tracking up into
the eastern Great Lakes on Wednesday. As it does so, a secondary
coastal low will develop off the Mid-Atlantic coast by Wednesday
night while deepening as it moves up into New England on Thursday.
These features support another period of active and unsettled
weather with periods of rain starting as early as Tuesday night. For
now the heaviest rain looks to hold off until Wednesday and Thursday
where rain may be heavy at times. This potential is still quite a
few days out, so have continued to keep the forecast in line with
NBM guidance. PoPs have increased over the last 24 hours however,
now yielding roughly a 50-80% chance of rain on Wednesday and
Thursday. Shower chances decrease a bit Thursday night into Friday,
but still remain around 30-50% as the area remains situated under
the upper trough. Below normal temperatures are expected throughout
the period.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of overnight...Localize brief restrictions to IFR will be
possible due to areas of mist and low stratus but it won`t be
as widespread as last night. Best chances for seeing IFR will be
at ABE, TTN, MIV, and ACY. Towards the 9-12z timeframe, some
weakening showers/storms moving in from the west could pass
close to ILG, MIV, and ACY. S to SW winds around 5 knots. Low
confidence.

Saturday...Sub VFR conditions possible early in the morning with
showers and storms around. Otherwise, primarily VFR expected.
Very isolated showers and thunderstorms possible in the
afternoon and early evening, but much lower coverage than Friday.
Winds WSW around 10-15 kts with gusts to around 25 kts. Low
confidence on showers and storms in the morning and even lower
confidence on activity in the afternoon; moderate confidence
otherwise.

Saturday night...VFR. Winds W to WNW 10 kts or less.

Outlook...

Sunday through Tuesday...VFR. Occasional wind gusts up to 25-30
kt possible through Monday, otherwise no significant weather
expected.

Tuesday night through Wednesday...Sub-VFR conditions probable,
especially on Wednesday with rain showers likely.

&&

.MARINE...
Some weakening showers/storms could affect Delaware Bay and our
southern ocean zones as we get towards sunrise. These could
result in some locally strong winds. There could also be some
patchy fog over the waters. Otherwise, no marine headlines
expected through Saturday night though SW winds by the afternoon
will be around 15 to 20 knots.

For Sunday, a Small Craft Advisory is in effect for west winds
around 15 to 20 gusting up to 25 knots.

Outlook...

Sunday night...Lingering SCA conditions possible due to wind gusts
up to 25 kt.

Monday through Tuesday night...No marine headlines expected.

Wednesday...SCA conditions probable due to wind gusts around 25 kt
and seas building to 4-6 feet.

Rip Currents...

Currently projecting low risk of rip currents over the weekend
based on low wave heights of 1-2 feet and winds shifting offshore
at 10-15 mph.

&&

.TIDES/COASTAL FLOODING...
The Coastal Flood Advisory for northwestern Burlington and lower
Bucks Counties has been extended until 8 AM Saturday. Minor
coastal flooding is expected with the early morning high tide
on Saturday. It`s possible minor coastal flooding may occur on
Sunday as well, where further extensions may be needed.

For areas of the lower tidal Delaware River near Philadelphia
may encounter spotty minor coastal flooding through Saturday,
but should fall short of advisory levels.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory until 8 AM EDT this morning for PAZ106.
NJ...Coastal Flood Advisory until 8 AM EDT this morning for NJZ019.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 6 AM to 8 PM EDT Sunday for ANZ430-
     431-450>455.

&&

$$

SYNOPSIS...DeSilva
NEAR TERM...Fitzsimmons
SHORT TERM...DeSilva
LONG TERM...DeSilva
AVIATION...DeSilva/Fitzsimmons
MARINE...DeSilva/Fitzsimmons
TIDES/COASTAL FLOODING...PHI