685
FXUS62 KILM 240721
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
321 AM EDT Fri Jul 24 2026

.WHAT HAS CHANGED...
Confidence is increasing on the potential for an isolated flash
flooding event today through Saturday night. Expanded the Flood
Watch to include Horry, Williamsburg, Georgetown, Florence,
Marion, and Dillon Counties in northeast SC. The watch has also
been extended until 8 AM EDT Saturday. A moderate risk (threat
level 3/4) of excessive rainfall is possible east and south of
I-95 through Saturday morning.

Elsewhere, aviation discussion was updated for the 06Z TAFs.

&&

.KEY MESSAGES...
- 1) Stalled out front along the coast will bring an isolated flash
flood threat through Saturday night.

- 2) Forecast begins to dry out Sunday into early next week,
  with heat returning.

&&

.DISCUSSION...
.KEY MESSAGE 1...Stalled out front along the coast will bring an
isolated flash flood threat through Saturday night.

Latest surface analysis shows the frontal boundary draped across the
southern extent of the local forecast area, spanning roughly from
Kingstree to Conway to south of downtown Wilmington. An exceedingly
tropical atmosphere is building in, with precipitable water (PWAT)
values at or above 2 inches across most of the area, sans
Williamsburg and Georgetown Counties at 1.8-1.9 inches. In the
coming hours, PWAT values will shoot up into the 2.25-2.50" range.

Latest radar observations show clusters of rain with a few rumbles
of thunder across parts of the SC Pee Dee and NC coastal plain,
riding along shortwave energy aloft. This activity will slowly make
its way over to the I-95 corridor over the next few hours.
Meanwhile, at the coast, showers are much more isolated in nature,
with an overall lull in the activity expected to continue through
much of the morning hours.

The front will remain nearly stationary this afternoon, if not
nudging slightly closer to the coast. HREF probs soundly suggest
that the seabreeze will interact with this front, providing a good
convergence boundary for showers and storms to quickly pop along the
coastline sometime between noon EDT and 3 PM EDT this afternoon.
Rainfall rates could look particularly sporty here, especially if
there`s some extra shortwave energy aloft (4-6 inches/hour in some
spots).

Flood Watch remains in effect for all counties in southeast NC, and
has now been expanded to include Horry, Williamsburg, Georgetown,
Florence, Dillon, and Marion Counties in northeast SC. This watch
now goes through 8 AM EDT Saturday officially, but could be extended
further out in time in later forecast updates.

What happens beyond the seabreeze/front interaction this afternoon
becomes feast or famine, as far as rain and flooding concerns go.
Deep tropical moisture with lack of steering flow scream flooding,
but weak shear and thicker CAPE profiles don`t have it looking very
organized. And then of course, there`s the drought. In spite of
whatever limitations there are, HREF and REFS guidance is really
starting to pick up on isolated flash flooding, while the NBM has
yet to catch up on this idea. Collaboration with the Weather
Prediction Center (WPC) resulted in highlighting a "Moderate Risk"
(threat level 3/4) for excessive rainfall across the southern half
of the forecast area.

General trends seem to show a swath of rain over the Cape Fear
region late tonight through Saturday morning, transitioning to the
Grand Strand and Pee Dee regions by late Saturday into Saturday
night. Given the lack of organization with this system, it`s very
hard to determine where the heaviest rain swaths will set up, and
when. Most won`t see flooding, but within these isolated pockets,
some could be dealing with a potentially significant event. Overall
rainfall totals through Saturday night are expected to be 2-4
inches, with locally higher amounts in excess of 5-6 inches possible.

This is a complicated forecast with high bust potential, but leaves
me feeling a little uneasy. Be careful today and this weekend.

.KEY MESSAGE 2...Forecast begins to dry out Sunday into early next
week, with heat returning.

The front finally starts to push into the Atlantic Sunday, aided by
deepening surface low pressure. Forecast gradually drys out Sunday
through Tuesday. As a result, heat is on the rise, and triple digit
heat indices become a factor again as early as Monday. Another
frontal system may bring back some rain chances by midweek.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Pretty complicated 24hr TAF period as a front stall across the
area. For the next 6hrs:

Inland terminals should experience predominant IFR perhaps LIFR due
to stratus with intermittent light rain that could make it to the
surface and impact VSBYs but not seeing much of that now. Waves of
heavier rain are passing by to the north with some upstream to the
west moving slowly, will have to see how that holds together. Most
likely site to be impacted is KLBT.

Coastal terminals starting to dip into the typical SCT/BKN MVFR
CIGs, may need amends to avoid complicating TAFs further of I`ll
just go with predominant restrictions. Otherwise storms look to be
more of an issue towards the Fri morning/afternoon hours rather than
overnight. KILM is the terminal that could be most impacted through
the next 6hrs but it looks like it will be more towards dawn from
stuff slowly moving in from the west.

Headed into Friday we`ll have to deal with more hit or miss
showers/storms but with the atmosphere so moist VSBYs will be
heavily impacted should rain move over any terminals. These rain
chances in the TAFs will likely need tweaking with the next update
to try to target higher/lower confidence times, but for now
restrictions will be possible at all terminals during the day. There
could be a period of drier conditions (but still CIG restrictions)
Fri night with activity possible at the coast.

Extended Forecast...Potential for periodic MVFR/IFR due to storms
expected through late Sat, most numerous in the afternoons and
evenings. Conditions should start to dry out Monday with predominant
VFR returning, and prevailing through Tuesday.

&&

.MARINE...
Friday through Tuesday...A front will stall near the coast with
light S/SW winds prevailing and seas calming to largely 2-3 ft. The
main threat to mariners will be gusty winds and drops in visibility
due to moderate to heavy rain. The front is expected to eventually
drop south of our area with some uncertainty with timing. For now it
looks like Sunday the winds will become northerly briefly behind the
front before another approaches and S/SW flow builds back in through
early next week. Seas remain largely 2-3 ft through the period.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Flood Watch through Saturday morning for NCZ087-096-099-
     105>110.
SC...Flood Watch through Saturday morning for SCZ024-032-033-039-
     054>056-058-059.
MARINE...None.

&&

$$

WHAT HAS CHANGED...IGB
KEY MESSAGES...IGB
DISCUSSION...IGB
AVIATION...LEW
MARINE...LEW