141
FXUS62 KILM 261837
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
237 PM EDT Sat Apr 26 2025

.SYNOPSIS...
A cold front will move across the area tonight. High pressure
will build in behind the front Sunday into early next week with
dry conditions. Above normal temperatures begin Tuesday, with
rain chances returning late in the week ahead of the next front.

&&

.NEAR TERM /THROUGH SUNDAY/...
A little surprised nothing of note has developed across the
area this afternoon. Admittedly the timing was a little early
and there was a lot of cloud across much of the area this
morning, but with a surface trough/shortwave combo (albeit both
on the weak side) and SBCAPE over 1000 J/kg expected to see more
than isolated light showers pop up. The lack of activity this
afternoon suggest the PVA ahead of the shortwave is not very
strong, meaning the post wave subsidence should also be weak.
Skies are slowly clearing to the west which will allow a little
more heating this afternoon and, coupled with the lack of
convection along the coast, this could lead to a large area of
SBCAPE > 1k J/kg well into the evening. So a lack of convection
today could lead to an excess of convection tonight...

Expecting another round of showers and thunderstorms this
evening as the front moves in from the west-northwest later
tonight. The exiting shortwave/trough does complicate things a
bit as what subsidence exists behind the feature will need to
move off before the front and its convection arrives. Given the
weak nature of the shortwave this may not be an issue. Plenty of
moisture lingers into the evening with precipitable water still
above the 90th percentile until the front pushes south of the
area late tonight. Front arrives late, with surface based
instability trending down however, MLCAPE continues to increase
ahead of the front, peaking between 1500-2000 J/kg. Warm, moist
flow between 900-800mb is helping drive the increase in MLCAPE
which will support a line of storms ahead of the front. Not much
in the way a of a strong low level jet, maybe 30kt, which
should limit storm strength. Anticipate the broken line will
maintain itself across the entire forecast area, generally
moving from northwest to southeast, and then offshore after
midnight. The environment across the forecast area is more or
less the same above the boundary layer, although areas closer to
the coast will see an increase in surface based stability. This
should keep storms going with only a slight decrease in
strength as the storms move closer to the coast. Once offshore
the line should become better defined with cells strengthening
farther offshore.

Much drier air mass moves in behind the front which is followed
by a rapid shift to northerly winds. Cold advection sets up,
knocking temps down a bit, but combination of late start and
good mixing will keep lows above normal, although 5-7 degrees
cooler than the last few nights.

Surface high builds in from the north Sun with the region in
between the 5h trough offshore and the 5h ridge expanding north
from southern TX. Deep north to northwest flow drops pwats under
0.5" by midday with the only potential for cloud cover being a
few patches of high cloud moving in from the northwest. Highs
Sun will end up near to slightly below normal.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
Quiet with cool nights in the short term period as surface high
ridges down from the north through early Monday before shifting
off the Mid-Atlantic coast as mid level ridging builds over the
Southeast. Mostly clear skies and light winds Sunday night will
drop temps to around 50F, likely well down into the 40s in cold
spots, though some clouds associated with PVA may impact how
low temps get by Monday morning. Highs Monday will be near
normal (upper 70s-80F) with plenty of sunshine. Below normal
temps expected again Monday night in the low 50s.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Mid-level ridge remains strong over the Southeast through at
least Wednesday, likely maintaining influence through Thursday.
Low level south-southwesterly flow (around offshore high) and
increasing 850 temps will lead to above normal temps Tuesday
through Thursday, potentially reaching 90F inland Wed and Thurs.
A front stalls well to the north across the Mid Atlantic
Wednesday into Thursday courtesy of stubborn ridge. Have
maintained 20-30% pops across inland areas Thursday afternoon,
where subsidence may be a bit weaker. Better rain chances are
forecasted for Friday as subsidence inversion disappears and
instability develops. A shortwave and associated PVA looks to
move across the area sometime Friday (rounding the base of a
larger trough over the Great Lakes), but strength and timing of
this shortwave is uncertain which will play a role in coverage
and timing of Friday precipitation. The next FROPA is progged
for late Friday with high pressure building in behind it.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
Anticipate widespread VFR through 00Z. Coastal terminals may
get a brief shower prior to 20Z, but showers are weak enough
that even MVFR seems a difficult threshold to reach. Not
expecting any IFR with the weak showers. Not impossible that
some development in the next hour along the coast could lead to
a significant impact at one of the coastal terminals, but
chances are rapidly decreasing.

Cold front tonight will bring a wind shift to the northwest,
although the bigger concern will be ahead of the front. More
robust showers and thunderstorms expected ahead of the front
which could lead to a period of MVFR or IFR late evening inland
and around midnight for coastal terminals. Confidence is not
very high though given the struggles thus far today and the
front is arriving at night and in the wake of a shortwave
(albeit a weak one). Once any storms that do develop move east
of a terminal VFR will be quick to develop and then continue
through 18Z Sun.

Extended Outlook...Generally VFR. MVFR/IFR with both visibility
and ceilings possible Wednesday morning.

&&

.MARINE...
Through Sunday...Enhancement of southwest flow this
afternoon/evening ahead of a cold front tonight will push speeds
to 15-20 kt. Front will be accompanied by a wind shift to
northwest after midnight. Limited surge tonight with the front
and speeds not expected to climb much above 15 kt. Gradient
becomes more defined on Sun as the high starts to really build
in and the winds veer to northeast. Wouldn`t rule out a surge to
around 20 kt later Sun morning but then speeds should start
decreasing. Seas 3-4 ft through the frontal passage may dip down
to 3 ft before bouncing back up to 3-4 ft for much of Sun after
the northeast surge arrives. Seas will be a mix of a southerly
wind wave and a southeast swell into Sun but then seas will
become very chaotic as a northerly wind wave quickly becomes
dominant but the southerly wind wave and the southeast swell
persist.

Sunday Night through Thursday...Benign marine conditions
expected through Thursday. High pressure ridges down from the
north Sunday north through early Monday before moving off the
Mid Atlantic coast, with NE winds across the local coastal
waters through midday Monday before veering to relatively light
onshore flow. Seas 2-3 ft Sunday night through Tuesday,
primarily from E swell with wind wave mixed in. With high
pressure offshore, south-southwesterly flow dominates from late
Tuesday through Friday, sustained around 10-15 kts with gusts to
20 kts Wednesday and Thursday. Seas linger around 2-3 ft
Tuesday through Thursday, combination of persisting E swell and
slowly building S wind wave.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory from 8 PM to 11 PM EDT this evening for
     NCZ107.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
NEAR TERM...III
SHORT TERM...VAO
LONG TERM...VAO
AVIATION...III
MARINE...III/VAO