482
FXUS62 KILM 251757
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
157 PM EDT Wed Jun 25 2025

.SYNOPSIS...
Hot temperatures combined with high humidity will create
dangerous heat again this afternoon. Storm chances return today
as the upper ridge begins to weaken and an upper low approaches
the Florida coast. Typical afternoon storm coverage is expected
through the weekend.

&&

.UPDATE...
No major changes coming down the track as we approach 2 PM EDT.
Updated 18Z TAF discussion found below.

&&

.NEAR TERM /THROUGH TONIGHT/...
Another day, more heat. Ridging at the surface and aloft
remains in place, maintaining the heat and humidity. Despite the
strong ridging it does look like today will be a convectively
active day. The deep ridging remains centered over the eastern
half of TN which leads to weaker subsidence over the forecast
area. The ridge is also entering a weakening phase being
slightly weaker when compared to Tue, when a few storms were
able to develop.

The heat and humidity will create an impressive storm
environment with SBCAPE and MLCAPE exceeding 4k J/kg in many
areas. Mid-level lapse rates AOA 8 C/km today are more of a
function of the very warm low levels, 850mb temps around 20C, as
opposed to cold temperatures aloft, temps at 500mb around -10C.
To put this in perspective, based on sounding climatology the
500mb temps are 1-2 degrees below normal while 850mb temps are
5-7 degrees above normal. DCAPE is also quite impressive with
values ranging from 1000 J/kg to over 1500 J/kg. This is a
function of the low level dry air, a remnant from the mid- level
dry air from past days strong subsidence. The low/level dry
air/DCAPE increase the potential for damaging wind, despite
forecast soundings not showing winds over 40kt until 33k ft.
While damaging wind will be the main threat and the reason for
the SPC slight risk cannot rule out large hail despite freezing
levels around 15k ft due to the strength of the updrafts in
strongest storms. It will take a while for clusters of storms to
develop. The mid-level subsidence is weaker, but need temps
approaching 100 to break the cap. An isolated shower or
thunderstorm is possible in the early afternoon, especially in
the vicinity of the sea breeze, but more widespread convection
will be delayed until later in the afternoon/evening.

No changes to the heat headlines, although similar to yesterday
the heat warning is of a marginal nature. Seems unlikely to get
2 hours or more of 110+, but do not like the optics of lowering
a warning to an advisory when the heat persists. Highs will
again range from lower 90s along the immediate coast to around
100 inland. Lows will still run above normal, but only by a few
degrees as afternoon and evening convection help knock the heat
back.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
Depending on how much activity develops on Wednesday, Thursday
should feature isolated or widely scattered thunderstorms. If
the atmosphere is sufficiently worked-over, isolated storms
would focus along the sea breeze initially and along the inland
thermal trough by late afternoon. Given the substantial amount
of accumulated energy stored over the last few days with 100+
degree heat, if convection remains isolated on Wednesday, the
lack of any meaningful inhibition could see cold pools foster
the downstream development of convection on Thursday afternoon.
We`ll have a better idea with tomorrow night`s forecast.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
The remainder of the upper ridge will diminish on Friday with
an upper low over the southeastern states. Weak subsidence on
the periphery of the low could inhibit scattered storm
development. However, mesoscale processes will likely control
storm development. Sea breeze showers earlier in the afternoon
will give way to a better chance of storms inland later in the
afternoon (slightly higher PoPs over northeastern SC on Friday).
Warm with highs in the 90s. Expect a similar story on Saturday
with slightly higher PoPs as the low devolves into the large
scale zonal pattern to the north.

Sunday, and possibly Monday, will serve as a transition to an
approaching upper level trough. Expect a slight increase in
storm coverage again on Sunday and Monday. Troughing over the
eastern half of the US early next week should yield a better
than average chance for storms. While details are limited, the
slightly cooler upper level temperatures should be enough to
signal increased storm development each afternoon through the
end of the period.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
High confidence in VFR to kick off the 18Z TAF period, for now.
Scattered storms have started to initiate within the last hour
or so, with one cell about 20 miles northeast of KILM. There`s
no considerable synoptic flow in place, so it may take this
storm awhile to make it to this terminal, if at all. Generally
looking at 19-20Z.

Elsewhere, anticipate better coverage at inland terminals, with
KFLO looking to have the best chances. Threw in TEMPO groups at
all terminals, with the best chances lingering between 20-01Z
this afternoon/evening. Storms have the potential for strong
wind gusts of 35kt or higher. However, with storm coverage
still somewhat uncertain, have opted not to include gusts
within the TAFs. Storms will be moving, albeit slowly, from
north- northeast to south-southwest.

Storms come to an end during the evening hours with the loss of
heating. Light and variable winds expected overnight with
lingering debris clouds. May see some fog development tonight
wherever the storms occurred previously, especially if there was
considerable rainfall. However, winds at the top of the
boundary layer will be close to 10 kts, which typically creates
enough mixing to keep fog patchy and visibility above 3SM.
Seabreeze kicks up again towards the end of the period.

Extended Outlook...Mainly VFR with brief MVFR possible in the
afternoons.

&&

.MARINE...
Through Tonight... Another day with winds under 10 kt into the
afternoon before the sea breeze enhances winds nearshore. Brief
period of 10-15 kt is possible this afternoon, especially across
the SC nearshore waters, but by evening winds will be back
under 10 kt with a west-southwest component resuming once the
sea breeze circulation collapses. Light winds will keep seas 1-2
ft with both a southeast swell and southerly wind wave present.

Thursday through Sunday... Bermuda high will bring southwest
winds around 10-15 mph through the weekend. Seas at 1-2 feet on
Thursday will gradually start to increase as southwest winds
become more substantial. SE swell arrives this weekend at 2-3
feet and 8-9 seconds.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Extreme Heat Warning until 8 PM EDT this evening for NCZ087-
     096-099-105-107-109.
     Heat Advisory until 8 PM EDT this evening for NCZ106-108-110.
SC...Heat Advisory until 8 PM EDT this evening for SCZ017-023-024-
     032-033-039-054>056-058-059.
MARINE...None.

&&

$$

SYNOPSIS...ILM
UPDATE...IGB
NEAR TERM...III
SHORT TERM...21
LONG TERM...21
AVIATION...IGB
MARINE...III/21