123
FXUS62 KILM 241048
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
648 AM EDT Wed Apr 24 2024

.SYNOPSIS...
A weak backdoor cold front will bring only minor rain chances
this evening. High pressure will build in from the north
Thursday through Saturday with dry weather expected. A warming
trend will develop early next week as the high shifts offshore.

&&

.NEAR TERM /THROUGH TONIGHT/...
An upper trough moving quickly eastward across the Great Lakes this
morning will whip across New England this afternoon. A cold front
currently extending from Kentucky across the central Appalachians
will move southeastward, reaching the eastern Carolinas tonight. In
advance of the front, southwest winds should provide seasonable
temperatures today with highs in the upper 70s to near 80 inland.

Clear skies should last through early afternoon inland and through
mid afternoon along the coast. The approach of the front should be
accompanied by an increase in cumulus clouds, although these will
initially be limited in depth by a weak subsidence inversion near 700
mb. As this inversion erodes late in the day and a belt of better
mid level Gulf moisture arrives from the west, clouds should become
more solid through this evening.

There are conflicting signs in the models about how much shower
activity will develop this evening. Although the airmass below 850
mb remains rather dry, there is little doubt we`ll have at least a
few hours of solid moisture between 800-600 mb, roughly 6000-15000
feet AGL. Isentropic analysis on the 300K surface this evening shows
largely neutral motion through this moist layer. Forecast soundings
suggest lapse rates roughly equaling the moist adiabat with minimal
convective instability present. The GFS plus many of the high-res
and convection allowing models still suggest good coverage of
showers - however the Canadian, ECMWF, and multiple machine learning
models based on EC input suggest much lesser chances. I`ll cap
forecast PoPs at 30 percent for this evening, only about 10 percent
higher than previous forecasts, and hope that the 12z models runs
converge on a clearer answer.

The cold front should slide off the coast after midnight. Only
modest cool advection is expected behind the front as skies clear
and forecast lows range from 55-60, except cooler west of I-95.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
High pressure will build in behind exiting cold front Thursday.
Winds will have shifted to the north with only a slight cooling
off, bringing high temps to the mid 70s most places instead of
high 70s from day before. Although water temps are creeping up a
bit, they still remain in the mid 60s so expect cooler temps at
the beaches and bleeding inland a bit in the afternoon sea
breeze.

A warm front extending from system over the Midwest will lift
north with any weak lift or pcp remaining west of the area. The
Coastal Carolinas will remain on the southern extent of high
centered over the Mid Atlantic to New England coast on Fri. This
will kick winds around to a more onshore direction, but overall
expect mainly dry weather with just some clouds later in the
day on Fri into the weekend. In the mid to upper levels a ridge
will begin to amplify and build in from the west with some
moisture in the way of higher clouds spilling over the ridge.
Any chc of pcp should remain west of the local area and east
over the waters Thurs and Fri. Should also see some aftn cu
associated with the seabreeze. High temps on Fri will reach into
the 70s again, but should be a few degrees lower than Thurs.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
High pressure will shift off the Mid Atlantic coast over the
weekend with an onshore flow over the Coastal Carolinas. Some
moisture convergence around the high and aftn sea breeze should
produce some clouds and possibly a stray shwr, but not enough
confidence to include any pcp chances in the forecast for now,
especially with the ridge building overhead. The center of the
sfc high will shift from the Mid Atlantic coast southward and
will become situated off the Southeast coast. This will lead to
winds veering around slowly through the weekend, becoming
southerly Mon into Tues. This should help with warming and temps
reaching back into the 80s into early next week.

Overall, expect mainly quiet weather with limited potential for
clouds and pcp with unseasonably warmer weather into early next
week.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR should continue through the day. Breezy southwest winds
may gust to 15-20 kt after sunrise. The approach of a cold
front should lead to increasing mid to late afternoon cumulus
clouds, merging into a broken deck by this evening with
scattered showers dotting the area. At this time there do not
appear to be widespread ceiling or visibility concerns with
these showers. As the front moves offshore in the 07-09z
timeframe, there is a moderate potential for MVFR visibility
restrictions to develop in ground fog inland, and a low
potential near the coast.

Extended Outlook...There is a low potential for MVFR to IFR
visibility in ground fog Friday morning.

&&

.MARINE...
Through Tonight...
High pressure has moved a couple hundred miles off the Southeast
coast. The pressure gradient along the high`s backside has tightened
and allowed southwest winds to increase to around 15 knots this
morning. The approach of a cold front, currently located across
Kentucky through the central Appalachians, should maintain these
speeds throughout the day. This afternoon`s seabreeze will locally
increase speeds to near 20 knots, particularly along the Grand
Strand and Pender/New Hanover county coastline.

The front will arrive here at the coast after midnight, accompanied
by a shift to northwest winds. Scattered showers may precede the
front`s arrival during the evening hours.

Seas currently consist of 2-3 foot 10 second east swell along with a
2-3 foot wind chop. Combined seas should average 4 feet today,
although it will be an awfully rough 4 feet given the direction
differences in swells vs wind waves. The swell will continue through
tonight although wind waves should diminish with the arrival of the
front.

Thursday through Sunday...
Winds shift around to the N-NE behind front early Thurs as high
pressure builds down behind cold front. Winds will become
onshore over the weekend around 10 to 15 kts as high pressure
shifts off of the Mid Atlantic coast. It will then shift
southward and set up off of the Southeast coast leaving a more
southerly flow of winds into early next week. The onshore flow
will keep seas up 3 to 4 ft into the weekend and early next
week. No headlines this period.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...High Risk for Rip Currents through this evening for NCZ106-108.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...TRA
MARINE...TRA/RGZ