345
FXUS62 KILM 240004
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
804 PM EDT Thu May 23 2024

.SYNOPSIS...
Shower and thunderstorm chances will grow as a series of upper
level disturbances move across the region Friday through
Sunday, while a front remains stalled well north of the area.
Inland temperatures will rise into the lower 90s by Sunday, then
cool back towards normal by Wednesday behind a cold frontal
passage late Tue.

&&

.NEAR TERM /THROUGH FRIDAY/...
A ridge axis extending northeastward from a mid and upper level high
centered over the Gulf of Mexico will move off the Carolina coast
this evening. Behind this ridge the westerly flow near and above 700
mb will bring cooler air overhead, removing the convective cap that
has remained across the Carolinas for the past several days.
Precipitable water along the coast should increase from around 1.2
inches this morning to 1.8 inches by Friday morning. A series of
upper level disturbances should begin to arrive tonight, each
potentially accompanied by a wave of showers and thunderstorms.

Timing of these disturbances starts easy but gets more muddled with
time. Disturbance #1 is discernible in water vapor imagery now
across central TN into Alabama and should move across the eastern
Carolinas tonight. My forecast shows an increasing trend in inland
PoPs after 9 PM, peaking around 40 percent late in the evening, then
diminishing again after 1 AM. It`s less likely this initial wave
will reach the coast intact although clouds should certainly
increase. Forecast lows are generally in the upper 60s inland to
around 70 on the coast.

Mesoscale subsidence behind tonight`s initial impulse may keep
convection isolated Friday morning, but renewed convective activity
should develop during the afternoon hours as surface-based
instability rises to near 2000 J/kg and modest DPVA overspreads the
region in advance of another disturbance slowly approaching from the
west. High-res models suggest the seabreeze front should be a
significant trigger for convection, and my forecast PoPs are highest
(60 percent) just inland from the coast. Forecast highs are in the
upper 80s, except lower-mid 80s at the beaches.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
Still expecting an active pattern for the weekend via
the mostly zonal mid level flow and embedded short waves. Of course
the inland Piedmont Trough and to a lesser extent the sea breeze
will play a part as well. The highest pops occur Friday night and
again Saturday pm. Guidance is trending toward formidable NVA in the
wake of Saturday`s system for Sunday and pops may need to be reduced
further there if this continues. Temperatures look to remain above
climatology throughout.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Active pattern continues for the first part of next
week as the west to east mid level flow pushes to the south slightly
with remaining embedded shortwaves. It appears the best forcing in
several days may occur Tuesday evening when all of the elements
(surface front, mid level height falls) combine. Beyond this still
expecting dry conditions to develop along with cooler temperatures.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
An upper level disturbance to approach from the west overnight
into Fri. Have indicated a VCTS/VCSH for the inland terminals
by 04z/05z with activity likely dissipating as it pushes closer
to the coast during the pre-dawn Fri hrs. Could see a round of
low stratus around a 2-3 hr window around sunrise. A better shot
of convection from generally 18Z Fri thru the remainder of the
fcst period. May use PROB30 groups to highlight at this time
given the upper disturbance, the sea breeze and says insolation
aiding increasing instability.

Extended Outlook...Scattered thunderstorms will be accompanied
by periodic short lived MVFR/IFR conditions through the weekend
into Monday. The best potential appears to be Friday and
Saturday afternoons when thunderstorm potential coverage and
potential increases at or above 50 percent, especially inland.

&&

.MARINE...
Through Friday...Surface high pressure will retreat east to near
Bermuda tonight as a series of weak upper level disturbances
begin to move across the Carolinas from the west. Synoptic winds
will remain south to southwest at less than 10 knots, however
some higher winds will persist along the coast through this
evening due to today`s well- defined seabreeze circulation.
Additional periods of stronger winds could accompany scattered
thunderstorms on Friday, expected to be most numerous during the
afternoon hours. A few of our high-res weather models including
the HRRR explicitly indicate west to northwest thunderstorm
outflow winds developing along the South Carolina coast late
Friday afternoon.

Outside of any thunderstorms, sea heights of only 2 feet are
expected through Friday consisting of an eight second easterly
swell plus local wind chop.

Friday night through Tuesday...Overall light winds will persist
into the weekend from the south to southeast as the pressure
pattern remains weak. In time the flow will turn more from the
southwest and increase a bit in magnitude. This occurs early
next week. Significant seas will be 2-3 feet this weekend
perhaps increasing to a range of 2-4 feet early next week.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory until 1 AM EDT Friday for NCZ107.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DCH
MARINE...TRA/SHK