333
FXUS62 KILM 130041
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
841 PM EDT Sat Sep 12 2026

.WHAT HAS CHANGED...
No major changes needed to the current forecast. With the mid-
level trough west of the forecast area widely scattered showers
and few t-storms will persist overnight and move toward the
northeast. The current forecast has 15-30% and should
effectively handle this. Aviation discussion was updated for the
00Z TAF set.

&&

.KEY MESSAGES...
1) Deep Gulf moisture and a break in the ridge aloft will
maintain good chances for showers and thunderstorms through
Sunday.

2) A modified Canadian airmass should bring cooler temperatures
beginning Tuesday.

&&

.DISCUSSION...
KEY MESSAGE 1...Deep Gulf moisture and a break in the ridge
aloft will maintain chances for showers and thunderstorms
through Sunday.

Forecast convective development today has been scaled back
significantly compared to what NBM and synoptic models were
suggesting over the past 2-3 days. On a broad scale the culprit
may be subsidence from persistent offshore convection. On a
more local scale, persistent mid level clouds inland, subsidence
behind a subtle shortwave lifting northward across North
Carolina, or the lack of strongly convergent surface boundaries
could be to blame. Forecast PoPs through early evening have
been scaled back to only 30-40 percent which is still higher
than most of the recent CAMs suggest.

For any storms that do manage to develop this afternoon, the
airmass should still support locally heavy rain given slow cell
motion and anomalously high precipitable water values near 2.25
inches.

CAMs suggest new showers and thunderstorms may begin to develop
across the coastal waters around midnight. Mid level winds
would tend to bring these northeastward where they could drop
rain across portions of Brunswick and New Hanover counties late
tonight into Sunday morning.

Sunday`s daytime seabreeze front may be the focus for additional
scattered showers and storms. The mid level flow will veer more
westerly on Sunday as a shortwave moves eastward across the
Carolinas. Bulk shear should also increase to 15-20 kt which
may lead to multicell storms redeveloping along boundaries like
the seabreeze front. Drier conditions developing aloft inland
during the afternoon should tend to reduce coverage of showers
or storms there.


KEY MESSAGE 2...A modified Canadian airmass should bring cooler
temperatures beginning Tuesday.

The strongest Canadian high, 1030 mb, we`ve seen since last
spring will move eastward across southern Quebec and New England
Monday through Tuesday, pushing a cold front southward. Models
are in excellent agreement showing the boundary will push
across Cape Fear early Monday evening, racing southward past
Myrtle Beach and Georgetown before midnight.

Modified Canadian air will spread southwestward behind the
front Monday night, scouring out the excessive humidity and
unseasonable warmth of the past week. Given the long path over
75-85 degree water off the East Coast, this won`t feel like a
crisp fall airmass although it will be cooler and drier.

Forecast highs Tue-Thu should hold in the 80s, close to normal
for this time of year. The big improvement will be with
nighttime lows: models have continued to trend lower each run
and now show some potential for upper 50s in spots inland
Tuesday night. Dewpoints in the 50s and 60s will feel very
refreshing.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR conditions currently prevail this evening at all terminals.
Isolated convection near KFLO thus far, but if trends continue
with upstream convection moving into the area may need to
include TEMPO restrictions. Impulse will move toward the
northeast with the mid-level trough approaching the
Appalachians tonight. Could see pockets of restrictions during
the early morning hours with strato-cumulus or some stratus.
Sunday`s seabreeze front could also be a potential focus for
new showers or storms affecting KMYR and KCRE mainly after 16z.

Extended Outlook...There is also a low potential for late
night/early morning stratus or ground fog affecting KLBT and
KFLO late Saturday night and again late Sunday night. VFR
conditions should prevail Monday through Wednesday as a more
stable and drier Canadian airmass builds in from the northeast.

&&

.MARINE...
Tonight through Thursday...Aside from anticipated waves of
showers and thunderstorms developing late tonight into Sunday
morning, then additional isolated showers/storms Sunday
afternoon along the seabreeze front, marine weather conditions
won`t be too bad for the next couple of days. Synoptic winds
from the southwest should average 10-15 knots with seas
averaging 2-3 feet in a mixture of wind chop and a 9 second
southeasterly swell.

Big changes should arrive Monday evening as a cold front sweeps
quickly across the area from the north. A surge of
northeasterly winds should follow the the front, driven
southward by the strongest Canadian high we`ve seen since last
spring. Northeast winds 15-20 knots, occasionally reaching 25
knots at times, should develop Monday night and persist through
Wednesday. There`s better than 50-50 chances wind/wave
conditions will necessitate a Small Craft Advisory beginning
Monday evening.

&&

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

&&

$$

WHAT HAS CHANGED...SRP
KEY MESSAGES...TRA
DISCUSSION...TRA
AVIATION...MBB/SRP
MARINE...TRA