Area Forecast Discussion
Issued by NWS Wilmington, NC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KILM 271725
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
125 PM EDT Wed Mar 27 2024

.SYNOPSIS...
A strong storm system will produce moderate to heavy rain late
today through early Thursday. Dry high pressure then builds in
Thursday night with a warming trend through the weekend with dry
weather.

&&

.UPDATE...
Temperature updates continue to be a small battle given the
current location of the cold front. A tight gradient will remain
mostly stationary today and will gradually push eastward this
evening. Updated PoPs to correspond to the relatively quiet warm
sector. Things should begin to fill-in late this afternoon and
into this evening.

&&

.NEAR TERM /THROUGH TONIGHT/...
Latest surface analysis shows a warm front draped across parts of
South Carolina, stretching from the CSRA and Midlands to Lowcountry.
This front has been sluggish in its movement over the last few
hours, with dry air lingering ahead of it at 700mb and above.
Virtually no rain to speak of as the overnight hours have played
out, with the lone exception being some radar estimated
accumulations of a few hundredths of an inch in parts of Marion
County several hours ago. Despite the lazy movement of the front and
dry air aloft, dewpoints have slowly been increasing. Isentropic
lift at 290-295K (and to a lesser extent, 300K) is the reason for
this, which will help moistening from the lower levels of the
atmosphere.

This subtle lift and moistening will continue ahead of the lifting
warm front. This front will eventually lift north of the local
forecast area by the mid-morning hours. Precipitable water values
currently linger in the 1.1-1.4" range, and will be escalating up to
1.5-1.75" by this afternoon. Increased shortwave energy ahead of the
main trough will come in from the southwest late this morning into
the afternoon, which ramps up the rain chances. Scattered showers
late this morning and midday will give way to more widespread rain
late this afternoon and evening. Instability still looks meager
overall, but a few rumbles of thunder are still expected with this
system.

Much more potent shortwave energy comes in this evening through the
overnight hours tonight, which is where the heaviest rain will come
in. Current rainfall forecast paints the highest amounts across
southeast NC, where generally 2-3 inches are expected, with locally
higher amounts possible. 3-hourly flash flood guidance (FFG) in
these areas is sitting at 3-4 inches, and considering that the 2-3"
forecast rainfall totals are expecting to occur over a span of 12+
hours, this does not scream a flash flooding scenario. CREST soil
moisture values in these same areas are 25% at best, which helps
reinforce this idea. Still, isolated areas of flash flooding cannot
be ruled out, with the area being in a "Marginal Risk" (threat level
1/4) for excessive rainfall.

Meanwhile, the Storm Prediction Center (SPC) has put northeast SC in
a "Marginal Risk" (threat level 1/5) for severe weather. As
mentioned before, instability does not look impressive, but
considering the expected lull in activity during the morning hours,
some extra instability could build in. Bulk shear does eclipse 50kts
this afternoon, and in some cases, nears 60kts by tonight. Even so,
a stable layer up to 850mb will act to protect the area from the
stronger winds. Regardless, a couple of strong storms cannot be
ruled out, with wind being the main concern, especially tonight. In
any case, have a way to receive warnings, particularly during
nocturnal events where you`re likely to be asleep.

Highs this afternoon in the lower 70s. Lows tonight in the mid
50s.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
Sfc low pressure strengthens off the coast Thursday as a potent
upr-level trough approaches from the west. Favorable dynamics
and strong moisture feed support moderate to heavy rain early in
the day, especially over eastern areas. Guidance in good
agreement now that the precip ends from west to east through
the afternoon, leading to a dry Thursday night. With decreasing
clouds expect low temps in the low/mid 40s, with 30s not
expected (outside of typical cold spots) due to breezy NW
winds.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Quiet and dry weather this period as sfc high pressure builds
over the SE states this weekend. Fairly zonal flow aloft
transitions to subtle ridging, with increasing temps through the
period...highs in the mid 70s Saturday increase to around 80
Sunday through Tuesday. Low rain chances return late this
period, but confidence remains low as its uncertain if the
shortwaves embedded within the westerly flow aloft will pass
directly over the area or stay off the north.

&&

.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
VFR in warm advective flow along the coast and most of our
inland areas east of I-95. Other than some passing showers which
will bring MVFR, expect this to continue into this evening.
Inland, MVFR seems to be dominant near the leader edge of a
stalled cold front near I-95. As this front creeps eastward this
evening, MVFR will gradually worsen to IFR behind the front.
Heavy rain and elevated instability will lower VIS at all sites,
progressing from west to east this evening and after midnight.
LIFR in heavy rain behind the front will improve slightly after
sunrise tomorrow morning although heavy rain may continue
through mid morning. Winds out of the SE this afternoon and
this evening will be gusty before turning light and variable
during the front`s passage, becoming northerly behind the front.

Extended Outlook...Flight restrictions likely into Thursday
with increasing rain chances. Forecast dries out Thursday night
and high pressure returns throughout the weekend, allowing for
widespread VFR.

&&

.MARINE...
Through Tonight...ESE winds at 10-15kts gradually become more SE by
late this morning after a warm front lifts northward. A cold front
will move into the coastal waters late tonight, creating a varying
wind direction that eventually moves towards the northwest. A few
gusts up to 20kts possible late tonight. Seas generally 3-4ft.

Thursday through Sunday...A SCA has been issued from midday
Thursday through Thursday night for 20-25 kt NNW winds following
the aforementioned front pushing offshore. Seas up to 5-6 ft.
Somewhat improving marine conditions expected towards the end of
the week as sfc high pressure builds over the SE states, with a
small chance for SCA conditions again Saturday night in SW flow
as the pressure gradient tightens slightly.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...None.
MARINE...Small Craft Advisory from noon Thursday to 4 AM EDT Friday for
     AMZ250-252-254-256.

&&

$$

SYNOPSIS...ILM
UPDATE...21
NEAR TERM...IGB
SHORT TERM...MAS
LONG TERM...MAS
AVIATION...21
MARINE...MAS/IGB


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.