416
FXUS62 KILM 180031
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
831 PM EDT Tue Jun 17 2025

.SYNOPSIS...
Warm and humid summertime weather will continue with
temperatures above normal for most of the week. Frontal passage
will lead to a slight uptick in rain chances late Thursday into
Friday. Strong ridge of high pressure over the eastern U.S. will
lead to a warming trend Sunday into next week, with a potential
for increased heat risk Monday and Tuesday.

&&

.UPDATE...
Main update was to POP for far western counties of the forecast
area. Current ongoing convection southwest of these areas is
along a SBCAPE gradient with a peak in the neighborhood of 4k
J/kg. High res guidance suggests this gradient will persist
through 04Z or 05Z before surface based instability starts to
weaken. Cells will continue to track north-northeast during the
next few hours. Since this convection is being driven by the
high amount of surface based instability, the reduction in
instability will result in weakening storms and decreasing
coverage after midnight. No other changes were required for the
update.


&&

.NEAR TERM /THROUGH WEDNESDAY/...
Return flow around Bermuda high continues to feed in plenty of
warm and moist air. Dewpoints remain in the 70s and pcp water
values will continue near or above 2 inches. CAPE values upwards
of 3 to 4k j/kg both this afternoon and again on Wed, leave the
atmosphere primed for convection. With that being said, the H5
ridge was expanding northward enough to help keep shwrs and
storms more limited and sub- severe for the most part, and also
should die out each evening as daytime heating ends. The ridge
expands a bit farther north on Wed which should help to limit
convection a bit more. The main forcing mechanism to get any
convection going will be along the sea breeze boundary, inland
Piedmont and localized boundaries or outflows that develop. Any
storms that develop will produce a brief period of very heavy
rain, possible lightning and cannot rule out a wet microburst or
brief stronger wind gust. They should also collapse fairly
quickly.

Winds should remain SW with a slight backing and spike upwards
in the aftn sea breeze. Models show winds holding up enough
overnight to avoid fog but can not rule out a bit of stratus
near sunrise. Overnight lows will be in the mid to upper 70s in
a continued warm and muggy air mass.

The building ridge will produce further h5 height rises into
Wed aiding in some well above normal temps, reaching 2 to 3
degrees higher than today, mainly between 90 and 95. Looks like
the heat indices will be between 99 and 103, remaining below
Heat Advisory criteria of 105. Therefore will hold off on Heat
Advisory for now, but a slight uptick in temps or dewpoints
could change that. Overall, hot and humid weather will continue.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
Mid level ridging will be weakening during the day Thursday as
a trough approaches from the west. Expect partly cloudy skies
and widely scattered storms Thursday afternoon, with high temps
in the low 90s. Combined with persistent dewpoints in the 70s,
heat indices are likely to eclipse 100F but stay below the 105F
criteria for a heat advisory. A weak surface front is forecasted
to move across the area late Thursday/Thursday night, with
scattered storms developing ahead of and along the front into
overnight hours. Don`t expect much in the way of widespread
rainfall, and QPF is rather meager around 0.1-0.25". Low temps
both Wednesday and Thursday nights in the low to mid 70s.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
500mb trough and associated PVA will be delayed behind the
surface front, moving across the area sometime on Friday. This
will aid in scattered storms developing on Friday before mid
level dry air moves in from the west later in the day. Highs
near normal around 90F Friday. Near normal temps continue
Saturday, with mid level ridge beginning to build in from the
west and 500mb ridge approaching from the west. Could see a few
storms Saturday afternoon, mainly along the sea breeze.

The main feature of the long term period will be a large ridge
building over the eastern US Sunday into early next week. Latest
deterministic guidance has the 500mb ridge at around 600 dam
centered over the Ohio River Valley, which is almost 2-3
standardized anomalies above normal according to NAEFS and ENS.
Locally, this will begin a warming trend into next week. NWS
HeatRisk maps highlight chance for parts of our area to reach an
extreme risk of heat-related impacts next Monday, and a similar
risk likely for Tuesday, with current forecasted high temps in
the mid 90s and summertime dewpoints.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
High confidence in VFR through the TAF period. Southwest winds
will keep boundary layer well mixed tonight, preventing any
fog. Winds pick up on Wednesday with heating, afternoon gusts
around 25 kt will be possible, especially closer to the coast.
Increasing stability will limit development of deep convection
Wednesday afternoon with best chances (although still very low)
along the SC coast. Not carrying any mention of thunder in the
TAFS.

Extended Outlook...A front will produce periods of sub-VFR in
shwrs/tstms late Thurs into Fri. Otherwise, brief restrictions
due to widely scattered to scattered thunderstorms are possible.

&&

.MARINE...
Through Wednesday...Return flow around Bermuda High will
continue to produce SW winds mainly in the 10 to 15 kt range,
but expect a spike in winds each aftn in sea breeze near shore.
Winds on Wed will increase a bit as gradient tightens with some
gusts to 25kts. Persistent southerly push will keep sea up to 3
to 4 ft but can not rule out some 5 fters. A minimal longer
period SE swell will mix in.

Wednesday Night through Sunday...Southwest wind 15-20kt prevail
across the local coastal waters Wednesday night through
Thursday night before a front moves offshore and off to the east
early Friday. Winds become relatively light, around 10 kts or
less, behind the front during the day Friday. Continued light
winds through Sunday alternating between westerly and southerly,
as high pressure slowly builds in. Seas around 4 ft Wednesday
night through Thursday night lower to around 2 ft for late
Friday through Sunday, with a continued mix of SE swell and S
wind wave. Best chance of thunderstorms over the waters will be
Thursday night, ahead of the frontal passage, and again Friday
afternoon/evening as westerly mean winds advect any storms
offshore.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement from 6 AM EDT Wednesday through
     Wednesday evening for NCZ106-108.
SC...Beach Hazards Statement from 6 AM EDT Wednesday through
     Wednesday evening for SCZ054-056.
MARINE...None.

&&

$$

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