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545
FXUS62 KILM 230533
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
133 AM EDT Thu May 23 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.

&&

.NEAR TERM /THROUGH TODAY/...
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 /TONIGHT 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 /05Z THURSDAY THROUGH MONDAY/...
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Bulk of the forecast will feature VFR. Morning fog development
appears less likely than the last few nights given the strength
of the nocturnal jet. May have some FEW/SCT sub 1k ft ceilings
develop around daybreak, although confidence is on the low side.
Forecast soundings show a bit of moisture at the top of the
surface based inversion, but it does not appear to be enough to
warrant a BKN/OVC ceiling.

Other aviation concern will be potential for convection moving
in from the west-northwest late in the day then lingering
overnight. Currently appears NC terminals have the best chance,
but cannot rule out storms affecting at least some of the SC
terminals.

Extended Outlook...Morning low clouds/fog Friday morning.
Afternoon showers/storms through at least Monday.
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&&

.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...
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NC...None.
SC...None.
MARINE...None.
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&&

$$

SYNOPSIS...TRA
NEAR TERM...MBB
SHORT TERM...TRA
LONG TERM...TRA
AVIATION...III
MARINE...TRA/MBB