846
FXUS62 KILM 252335
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
735 PM EDT Sat May 25 2024

.SYNOPSIS...
Unseasonably hot and humid conditions are expected to continue
through Monday with scattered mainly afternoon and evening
thunderstorms continuing. An approaching cold front should
enhance thunderstorm coverage late Monday into Monday night.
Cooling trend and mostly dry weather expected Tuesday through
late week as front stalls near the coast before high pressure
builds in from the west Thursday.

&&

.NEAR TERM /THROUGH SUNDAY/...
Surface-based instability as large as 2500 J/kg across the Pee
Dee region is being tapped by this afternoon`s seabreeze front
plus an approaching shortwave aloft. This upper disturbance
kicked off storms across Tennessee and Georgia this morning and
should slide southeastward across the area this evening.
Forecast PoPs are as high as 60 percent across the Grand Strand
beaches, but decrease to 30 percent along the coast north of
Cape Fear where drier air aloft lingers and upper forcing may be
less pronounced than farther south.

Steep lapse rates plus westerly winds increasing to 25 knots as
low as 10kft aloft could help create an isolated wind damage
threat this this evening. Bulk shear across the surface to 6 km
layer is barely 15 knots, significantly less than what was
observed yesterday, limiting the degree of storm cell
organization expected. Today`s storms are reminiscent of what
one would expect in July across the Carolinas with heavy rain,
lightning, and isolated wet downbursts, but otherwise limited
organization.

Convective activity should settle down late this evening with
generally dry conditions expected overnight. A little patchy
ground fog could develop where heavier rain falls, and forecast
lows are generally in the upper 60s to near 70.

Our 500 mb heights will rise by almost 40 meters over the next
24 hours as the subtropical ridge centered across the Gulf of
Mexico expands northeastward. Despite warming and drying
observed aloft in model progs, unseasonably warm and humid air
at and below 850 mb should still create an unstable and uncapped
airmass Sunday afternoon. As much as I want to forecast a dry
day, I`m still putting 20-30 percent chances of afternoon
thunderstorms in the forecast for Sunday. Forecast highs range
from the mid 80s on the beaches to lower 90s inland with heat
indices reaching the upper 90s in spots.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
A band of weakening storms are forecasted to move across the
area from the west early Sunday night before clearing out. Low
temps in the low 70s with lingering boundary layer winds. Warm
and humid Memorial Day in store as WAA strengthens ahead of an
approaching front. High temps in the low 90s with dewpoints near
70F (much like Sunday). Main uncertainty is chances of daytime
showers and thunderstorms. Looks like there may be a window for
convection around midday, primarily along sea breeze, before a
dry slot looks to move across and a mid-level subsidence
inversion develops around 18-21z. PWATs pick up again and
inversion dissipates heading into Monday evening as the front
moves across the western Carolinas. Best chance for storms
Monday look to be Monday evening into overnight hours. Given
timing, not sure how much overlap will be left between
instability ahead of front and elevated shear along front.
Something to keep an eye on over the next two days.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Front expected to be near/along the coast Tuesday morning,
where it will stall for a day or two before being pushed
offshore as high pressure begins to build across the central US
midweek. Quite a bit of dry air inland beginning Tuesday - have
kept daytime pops Tuesday limited to slight chance near the
coast, and if trends continue even those pops may be removed.
While upper trough lingers over the northeastern US through
Friday, at the surface a cool, dry high pressure centered over
the Great Lakes ridges down into the Carolinas Thursday and
Friday. Upper level pattern remains a bit uncertain heading into
next weekend - regardless atmosphere looks to be quite dry for
a bit. A brief cooling trend in store after an above normal
Tuesday, before slowly warming heading into next weekend.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
Scattered showers and thunderstorms continue this evening, but
coverage will continue to slowly decrease as time goes on.
Mainly VFR conditions as of 23Z, with MVFR/IFR possible over the
next few hours should a storm pass over a TAF site. Otherwise,
VFR continues until patchy fog develops early Sunday morning,
especially inland, but confidence is not particularly high on
this so kept it MVFR for now and will further fine-tune in the
next TAF issuance. Sunday similar to today with fairly light
winds but rain chances are slightly lower (only 20-30%) so kept
any mention of rain out of the TAFs this far out.

Extended Outlook...Scattered mainly afternoon and evening
thunderstorms may be accompanied by periodic short lived IFR
conditions Monday and Tuesday.

&&

.MARINE...
Through Sunday...Low pressure over the central Plains and high
pressure well off the East Coast are providing the Carolinas
with a light southwest synoptic wind around 5 knots. Afternoon
seabreezes today and again tomorrow will accelerate winds near
the beach as high as 10-15 knots. In addition, the most
significant potential for thunderstorm outflow winds will be
this afternoon through this evening as several waves of showers
and thunderstorms move off the beaches, especially from Cape
Fear southward.

Outside of thunderstorms, seas should average only 1-2 feet in
height through Sunday, split between a 9 second southeast swell plus
local wind waves.

Sunday Night through Thursday...South-southwest winds around 10
kts Sunday night will be increasing during the day Monday as a
front approaches from the west. Winds peak around 20 kts with
gusts up to 25 kts late Monday afternoon/evening. In turn seas
increase from 2-3 ft Sunday night to around 4 feet Monday
evening with the building south wind wave. Chance for
thunderstorms over the waters Monday night ahead of an along the
front. Front expected to stall near the coast Monday night into
Tuesday morning, and linger there through Wednesday before
being pushed further off the coast as high pressure begins to
build inland. Winds generally around 10 kts or less Tuesday and
Wednesday, alternating between southwesterly and northwesterly,
with seas around 2-3 ft. Winds turn northerly on Thursday with
the building high pressure inland.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory from 10 PM this evening to 3 AM EDT
     Sunday for NCZ107.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
NEAR TERM...TRA
SHORT TERM...VAO
LONG TERM...VAO
AVIATION...MAS
MARINE...TRA/VAO