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310
FXUS62 KILM 231048
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
648 AM EDT Mon Sep 23 2024

.SYNOPSIS...
High pressure at the surface and aloft to prevail through mid
week. Unsettled weather should return Thu thru Fri as low
pressure or possibly a tropical cyclone, emerges from the
Eastern Gulf of Mexico and tracks possibly onshore. The
upcoming weekend will be dependent on what transpires with the
tropical cyclone or low.

&&

.UPDATE...
-- Changed Discussion --
Minimal changes to fog and visibility to account for current
observations. Otherwise, no significant changes with the 7 AM
EDT forecast update.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure to our north is nosing southward into extreme
eastern NC and has pushed a backdoor cold front through the
area overnight. Drier low levels to the northeast and warm and
humid conditions to southwest will influence high temps and
afternoon rain chances on Monday. A ridge over the southeastern
will move eastward today, allowing the ridge axis to position
itself along the Piedmont from SC to VA. This ridge will produce
warm temperatures again; highs in the mid 80s across much of
the area with upper 80s across portions of northeastern SC.
Areas in southeastern NC will remain slightly cooler behind the
surface front.

Weak shortwave energy will traverse the northern edge of the
ridge today and will provide additional lift for showers and
storms west of I-95. Have increased PoPs slightly higher than
models suggest due to warmer temperatures and elevated
instability available during the afternoon. Expecting isolated
to widely scattered afternoon showers with the additional lift
as some of these will overcome the limited inversion. Remaining
mild overnight with lingering shower chances; lows around 70.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Upper ridge axis to slide overhead Tue and off the East Coast
Wed. Sfc ridging from the north will slide off the Carolin a
Coasts during this period. Stalled front across the FA will
dissipate to a sfc trof across the inland Carolinas. Low level
flow will become more onshore veering from NE-E Tue and SE Wed
and thus an increase in low level moisture. Both days will see
maxes in the mid to possibly upper 80s, with daily lows in the
65-70 range except lower 70s at the beaches. POPs will peak
possibly in the modest chance cat, decreasing Wed to isolated
at best. The best forcing to occur Tu/Tue night due to
mentioned sfc features and mid-level s/w trof energy.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The long term period will be dependent on the tropical cyclone
in the Gulf Of Mexico early Thu that pushes onshore across the
NE Gulf Coast States. From there onwards in time, uncertainty to
prevail with respect to the future movement, strength and etc
of this tropical cyclone given slightly differing solutions of
the global models especially dealing with a progged
closed/cutoff low that drops down to the Lower/Mid Mississippi
River Valley during this period and has varying interactions
with this possible tropical cyclone. Have kept pops capped
around 50 due to this uncertainty. Should see clouds and
potential pcpn limit max temps to at or slightly below normal
and night time lows at or above normal, overall a lower than
normal diurnal range of temps.

To get the latest on the tropics, including preparedness info,
visit the ILM Tropical Page at: weather.gov/ilm/tropical.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
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Low clouds will be slow to clear inland this morning with
coastal areas already seeing broken cloud decks prior to
sunrise. Expect MVFR along the coast to become VFR quickly.
Inland, the forecast is a bit trickier. Satellite indicates that
CIGs are firmly in place and gradual improvement could continue
through the late morning. Areas of fog should lift to low clouds
at FLO as IFR becomes MVFR by mid morning. Showers possible this
afternoon, mainly inland. Mid level debris clouds develop
tonight and could make low clouds/fog forecast difficult yet
again.

Extended Outlook... VFR through Wednesday or Thursday outside
of morning low clouds and fog. Cold front will approach the area
late this week and produce unsettled weather through this
weekend.
-- End Changed Discussion --

&&

.MARINE...
Through Tonight...A weak surge behind a backdoor cold front
will turn easterly this afternoon. Gusts will be enhanced along
the coast this afternoon in the sea breeze to around 15 knots.
Seas around 2 feet near the coast, increasing slightly farther
offshore where 2-3 foot seas will be possible. Showers and
storms will be possible tonight, but coverage is likely to be
limited as high pressure builds from the north.

Tuesday through Friday Night...Sfc ridging from the north will
slide off the NC and SC Coasts Tue, veering the winds to more
of an onshore direction, from the SE to SSE around 10 kt thru
Wed. Late Wed thru Thu, decent agreement amongst models with
SE-S winds increasing to possibly SCA thresholds. There-after,
later Thu thru Fri night, effects from low pressure or a
tropical cyclone moving onshore across the NE Gulf Coast states
may yield further deteriorating marine conditions.

Seas early on, Tue into Thu, will be primarily influenced by
the 10+ second period NE-E swell generated by Atlantic low
pressure churning well offshore the Mid-Atlantic coast. This
low will finally get kicked off further east during the midweek
period but still continuing to throw back swell. Increasing
SE-S wind waves expected Thu and beyond that may surpass SCA
thresholds and potentially continuing to increase in size by the
end of the work-week.

&&

.TIDES/COASTAL FLOODING...
Coastal flooding remains a threat this week with high
astronomical tides. Beaches are expected to reach minor
flooding (advisory criteria) again during the midday high tides
today and Tuesday. The Lower Cape Fear River is forecasted to
reach moderate flood stage (coastal flood warning criteria)
during the daytime high tide today. Minor flooding is expected
to occur during the overnight high tides, with upstream waters
working their way down the river combining with the high
astronomical tides. Coastal flooding along the Lower Cape Fear
River will impact Downtown Wilmington and Brunswick County on
the west side of the river, especially during daytime high
tides.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory from 10 AM this morning to 3 PM EDT
     this afternoon for NCZ106-108-110.
     Coastal Flood Warning from noon today to 7 PM EDT this evening
     for NCZ107-109.
SC...Coastal Flood Advisory from 10 AM this morning to 3 PM EDT
     this afternoon for SCZ054-056.
MARINE...None.

&&

$$

SYNOPSIS...ILM
UPDATE...21
NEAR TERM...21
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...21
MARINE...DCH/21
TIDES/COASTAL FLOODING...ILM