154
FXUS62 KILM 230244
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
1044 PM EDT Wed May 22 2024

.SYNOPSIS...
High pressure will retreat offshore tonight and Thursday.
Shower and thunderstorm chances will grow as a series of upper
level disturbances move across the region late Thursday through
Saturday while a frontal boundary stalls just north of the area.
Inland temperatures will rise into the 90s early next week, then
should cool behind a CFP Tuesday night.

&&

.UPDATE...
Kept the fog patchy in coverage. Did add additional clouds, low
stratus ie. 1k ft or less, mainly across the coastal counties
during the pre-dawn hrs up to a few hrs after sunrise Thu. This
based on latest guidance using various model time height series
for locations across the FA. )ne thing that stood out was a
10-20 kt SSW-SW winds just off the deck that should help keep
mixing avbl to keep fog limited in its occurrence and coverage.
Marine, did up SSW-SW winds up by a kt or 2, which brings speeds
around 10 kt. Seas generally around 2 ft with an E swell at 8
to 10 second periods dominating with the short period chop on
top.

&&

.NEAR TERM /THROUGH THURSDAY/...
Surface high pressure had been nosing in from the NE has
retreated and most of the area now seeing light S to SE winds.
This will remain the case for the entire near term meaning quiet
weather tonight with seasonable temperatures. In the mid levels
will will transition from ridging to flatter flow, the latter
always more susceptible to housing shortwaves. The vorts
depicted in guidance are quite weak and for the most part stay
to our north. Will continue to maintain POPs capped at 30 over
nrn zones but could definitely see how we get one last
rain-free day Thursday.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
A positively tilted mid and upper ridge axis will move off
the Carolina coast Thursday evening, allowing colder air at 500
and 700 mb to flood in from the west across the Carolinas. The
strongly capped airmass we`ve enjoyed for the past couple of
days will be replaced by moderate convective instability, no mid
level cap, and precipitable water values up to 1.8 inches.

Although scattered showers or thunderstorms may dot the area
Thursday night into Friday morning, we`ll be watching for the
arrival of what could be a well-defined upper disturbance later
on Friday. This potential disturbance appears to be convectively
generated on the GFS/Canadian/ECMWF Thursday afternoon across
NE Texas and moves quickly eastward across the Mid South.
Assuming this actually occurs as expected, higher shower and
t-storm chances should develop here Friday afternoon into the
evening hours. SPC does not have a Day 3 risk area outlined,
however strengthened mid level flow and steep lapse rates could
generate a wind threat.

Saturday`s forecast gets a little murky given the potential for
subsidence and mesoscale capping behind any Friday night storms
lingering offshore, but I`m still going to keep scattered
mainly afternoon showers and t-storms in the forecast.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Our 500 mb heights should rise by 40 meters between Saturday
evening and Sunday evening as an upper level ridge across the
Gulf of Mexico expands northeastward. While it might seem like
an easy "win" to remove all convection from the forecast with
renewed capping aloft, there`s still the westerly upper level
flow to contend with which can easily bring fast-moving MCSs
across the Carolinas given rather subtle disturbances aloft.
For this reason I won`t stray too far from blended MOS PoPs
through the extended period.

As the ridging aloft builds Sunday and Monday it appears
inland high temperatures may soar to 91-94 degrees, near the
warmest of the year so far and similar to what we experienced
back on May 8th.

For Tuesday and Wednesday, all models want to carve out a
trough across the Great Lakes extending southward to the
southern Appalachians. There are indications 500 mb heights
could fall by 40-60 meters by Wednesday with decreases in
temperatures expected behind a Tuesday night cold front.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR for the most part, the only exception will be the chance
for MVFR fog and/or MVFR/IFR low stratus around or below 1k
ft, during the pre-dawn Thu hrs up thru 12Z Thu. SSW-SW winds
10-20 kt just off the deck will help keep the sfc winds at or
below 5 kt after the demise of the sea breeze. This will help
keep sfc rad fog limited but the elevated moisture may be
enough for low stratus around 1k ft or lower.

Extended Outlook...Mostly VFR outside morning low clouds/fog
through Fri morning followed by periodic showers/storms
starting late Thu night with the threat last through Mon as a
cold front stalls in the vicinity.

&&

.MARINE...
Through Thursday...The continued retreat of higher pressures
will continue to lead to minor veering of the winds from SE
to S while speeds remain capped at 10kt. With only a tiny
swell component that leaves mainly wind waves, capped at 2 ft
through the period.

Thursday night through Monday...High pressure will retreat
farther offshore late this week as a weak cold front slowly
approaches from the northwest. Light southwest winds are
expected with seas only 2-3 feet. As the atmosphere becomes
more unstable getting out from beneath the warm ridging aloft,
isolated showers and thunderstorms could develop as early as
Thursday night with better chances developing Friday night. It
appears the front won`t make it down to the coastline, instead
stalling across interior North and South Carolina Saturday.
Thunderstorm outflow could temporarily shift winds across the
coastal waters northwesterly Saturday night, but winds should
come back around to the south and southwest again on Sunday.

Southwest winds should increase to 15-20 kt Monday as a strong
(for the season) area of low pressure moves across the Great
Lakes.

&&

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

&&

$$

SYNOPSIS...TRA
UPDATE...DCH
NEAR TERM...MBB
SHORT TERM...TRA
LONG TERM...TRA
AVIATION...DCH
MARINE...TRA/MBB