-- Discussion containing changed information from previous version are highlighted. --
035
FXUS62 KILM 221038
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
638 AM EDT Sun Sep 22 2024

.SYNOPSIS...
Other than isolated showers across Southeast North Carolina
this morning, expect a dry forecast for the remainder of the
weekend, with high pressure dominating. Temperatures to remain
just above seasonal norms through early next week. Next
appreciable rain chances look to return by the middle of next
week due to the passage of the next frontal system.

&&

.UPDATE...
Coastal flood warning in effect today from 11am to 5 pm for the
Lower Cape Fear River. Look for stage readings to reach moderate
coastal flood levels, aoa 6.8 ft MLLW.

Coastal flood advisory for minor coastal flooding for the
shoreline between Surf City NC and South Santee River SC.

Have kept low chance POPs, isolated, thru mid-morning.
Convective showers slowly dissipating but should re-fire later
this aftn and early evening due to the combined effects of a
passage of a weak mid-level s/w trof and a backdoor cold front.

&&

.NEAR TERM /THROUGH TONIGHT/...
The mid-level ridge axis will slide eastward this period, but
still remaining west of the ILM CWA, thus continuing the NW
flow aloft. The mid-level s/w trof will weaken as it slides off
the northern NC Coast and offshore early this morning. Another
dampening mid-level s/w trof will follow suit and actually drop
across the ILM NC CWA this aftn and tonight. With a backdoor
cold front dropping south, may see isolated convection this aftn
into this evening, in the vicinity of this front. POPs to
remain within the low chance category. Ample sun still expected
today with maxes in the mid to upper 80s with a few remote 90s
given the downsloping trajectory of the winds aloft. Later
tonight will be interesting as far as the potential for areas to
widespread fog and/or low stratus. At this point, stayed on the
optimistic side given the slow progression of the front
southward.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Ridge axis deepens slightly Monday, creating a dry and warm
forecast. Parts of southeast NC may have a bit more clouds to
contend with as part of the shortwave passing offshore. This only
serves to create a small temperature gradient across the area, with
highs in the lower 80s in the Cape Fear region, to the upper 80s in
the far interior portions of the Pee Dee and Grand Strand regions.

More moisture builds into the column Monday night through Tuesday
night, allowing for rain chances to return a little quicker than
expected (not that this amounts to much). Mesoscale features like
the Piedmont trough and seabreeze would help to spawn convection, if
any. Highs Tuesday about the same as the day before. Lows each night
in the upper 60s to lower 70s.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Uncertainty continues in the long term forecast period, at least
with the specifics of the large scale patterns. CMC and ECMWF are
starting to come together a bit more on an upper trough in the upper
Midwest spitting out a cutoff low that traverses through either the
Plains or Mid South towards the end of the week. GFS shows less
cutoff low and more of said upper Midwest trough sweeping through
the Great Lakes region late week, before going through New England
by the weekend. This creates timing and intensity differences on the
frontal system due to move through late week, which has been the
same old story these last several forecast cycles.

Regardless of the specifics, the bigger story is that this looks
like a warm and muggy period, certainly not something representing
astronomical fall. Rain chances on the rise, particularly Thursday
through Saturday as the front nears the area. Guidance shows the
front slowing and possibly stalling by the weekend, which is not
surprising. Highs in the mid-to-upper 80s Wednesday and Thursday,
before falling to the upper 70s to lower 80s by Friday and Saturday,
aided by thicker cloud cover or even FROPA. Better yet, hopefully
those dastardly 70s dewpoints are gone by the weekend. Keep those
pumpkin spice lattes on ice for now.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
VFR to dominate this 24 hr issuance period except the 6 hours
prior to sunrise Mon when fog and/or low stratus affects the
area, especially the inland terminals. A mid-level shortwave
trough will work its way SSE and off the NC Coast during early
today. Could see a few VFR showers affect the inland terminals
early on. Cloud decks generally occurring in the mid and upper
levels except for possible daytime Cu. Weak sfc high and a
relaxed sfc pg to yield SW-NW winds 10 kt or less during
daylight, becoming NE-ENE 5 kt or less later tonight as a
backdoor cold front drops to the area. May see an active sea
breeze at the coastal terminals given max temps upper 80s near
90.

Extended Outlook...Mainly dry and VFR until midweek when the
next cold front approaches. Expect daily early morning MVFR/IFR
due to fog/stratus.
-- End Changed Discussion --

&&

.MARINE...
Through Tonight...Diffuse pressure pattern ahead of a backdoor
cold front will result in a generally S to SW wind 5 to 10 kt
thru tonight. The exception will be the passage of the cold
front across the Surf City to Cape Fear waters by daybreak Mon.
This will result in winds becoming NE 10 kt or less for these
northern waters. Seas generally 2 to 3 ft and dominated by an
easterly swell.

Monday through Thursday...Onshore flow continues throughout the
period, mostly out of the ESE. Winds mostly at 10 kts,
increasing to 10-15 kts by Thursday. Seas remain locked in 1-3
ft through Wednesday night. By Thursday, a cold front starts to
approach the waters, where gradients tighten, allowing seas to
build up to 2-4 ft, with a few 5 ft waves spotted 20 nm from
shore.

&&

.TIDES/COASTAL FLOODING...
Coastal flooding remains a threat through the weekend into
early next week with high astronomical tides and a modest
northeast flow. The beaches seem secure for minor coastal
flooding requiring an advisory. However, criteria along the
lower Cape Fear River from Wilmington south may reach Moderate
Coastal flood thresholds requiring a Coastal Flood Warning.
Upstream waters working their way down the Cape Fear River will
also enhance the flooding along the banks of the lower Cape
Fear River including Brunswick County.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
NC...Coastal Flood Advisory until 2 PM EDT this afternoon for
     NCZ106-108-110.
     Coastal Flood Warning from 11 AM this morning to 5 PM EDT this
     afternoon for NCZ107-109.
SC...Coastal Flood Advisory until 2 PM EDT this afternoon for
     SCZ054-056.
MARINE...None.
-- End Changed Discussion --

&&

$$

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