689
FXUS62 KILM 101837
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
237 PM EDT Thu Sep 10 2026

.WHAT HAS CHANGED...
No significant changes have been made to the forecast over the
weekend into early next week.

&&

.KEY MESSAGES...
1) Shower and thunderstorm chances will increase this weekend.

2) Heat and humidity will build and heat indices should exceed
100 degrees through Monday.

3) Grand Strand minor coastal flooding is possible during
multiple high tides over the coming days.

&&

.DISCUSSION...
KEY MESSAGE 1...Shower and thunderstorm chances will increase
this weekend.

Models look broadly similar to yesterday showing the persistent
mid and upper level ridge across the Southeast U.S. breaking
down this weekend as a shortwave digs into the mid-Mississippi
Valley region. This will remove the subsidence inversion that`s
been capping us for days, and establish a deeper flow of Gulf
moisture that should bring precipitable water value up toward
2.2 inches by Saturday.

Today`s isolated showers are being vertically inhibited by warm,
dry conditions aloft within the upper ridge. Once that factor
is removed this weekend, forecast rain chances blossom: 20-40
percent Friday, 60-80 percent on Saturday, and 50-60 percent on
Sunday.

None of these days appear to be washouts and model storm-total
QPF through Sunday appears to have decreased in spots from
yesterday. A few lucky locations should still pick up 2-3 inch
totals over the coming days, with half inch totals likely more
common. Storm mode should remain single-cell with 0-6 km bulk
shear 10 knots or less. Loose storm organization along outflow
boundaries and the seabreeze front should occur.

Storm coverage should begin to decline Monday as the 700-500 mb
ridge redevelops just to our west, intercepting the flow of Gulf
moisture. The subsidence inversion reappears in forecast
soundings by Tuesday which should lead to much drier conditions
Tuesday and Wednesday.


KEY MESSAGE 2...Heat and humidity will build and heat indices should
exceed 100 degrees through Monday.

Light south to southwest low level winds should advect plenty
of Atlantic and Gulf moisture across the Carolinas through the
weekend. Dewpoints remaining in the 70s coupled with well-above
normal high temperatures in the lower to middle 90s should equal
heat indices rising above 100 degrees each day through Monday.

Tomorrow (Friday) appears to be the hottest day of the period.
Forecast 850 mb temps near +19C are 4C above normal and 1.5C
above the 90th climatological percentile at the KMHX upper air
site. Our current forecast high for Friday is still 4-5 degrees
F below daily records.

This unseasonably hot airmass should remain across the area
through Monday, but will be tempered by additional clouds and
precipitation. By Tuesday, Canadian high pressure moving across
New England should introduce a northeasterly low level flow
which should bring a slightly cooler marine airmass onshore with
forecast highs generally in the 85-90 degree range Tuesday and
Wednesday.


KEY MESSAGE 3...Minor Grand Strand coastal flooding is possible
during multiple high tides over the coming days.

September`s New Moon occurs today which is leading to a period
of larger astronomical tides. Tidal anomalies along the Grand
Strand beaches as measured at Myrtle Beach`s Springmaid Pier
should average around +1.0 feet today through the weekend. Half
to two-thirds of this anomaly is likely due to sea level rise
leaving onshore winds responsible for the remainder.

Forecast water levels should exceed flood stage at Springmaid
Pier by about 0.3 feet this evening, and may reach or slightly
exceed flood stage during high tides Friday morning through
Sunday morning. See the recently-issued Coastal Flood Advisory
for details.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
An area of showers offshore is spreading broken low
stratocumulus back toward the Grand Strand coastline. There is
a low probability of ceiling impacts at KMYR and KCRE between
18-20z before the offshore showers weaken or dissipate. New
convective showers are developing inland along and west of the
South Carolina seabreeze front this afternoon, but the
probability of impacts on airports is too low for mention in the
TAFs at this time.

Isolated showers should dissipate this evening and VFR
conditions are expected overnight. New convective showers may
begin to develop again Friday along the seabreeze front prior
to 18z.

Extended Outlook... Although VFR conditions will prevail, there
is increasing potential for pop-up showers and thunderstorms
bringing brief MVFR/IFR conditions, especially Saturday and
Sunday. There is also a low potential for late night/early
morning stratus or ground fog, particularly affecting KLBT and
KFLO Saturday and Sunday.

&&

.MARINE...
Tonight through Tuesday...High pressure off the Southeast coast
is weakening as a cold front moves southward. This front is
still expected to stall across interior North Carolina Friday
night before lifting back to the north Saturday. South to
southwesterly winds should continue with speeds less than 15
knots.

Increasing coverage of showers and thunderstorms is expected
beginning late Friday night as Gulf moisture increases across
the area, and as high pressure aloft dissipates and is replaced
by cyclonic flow ahead of an upper level trough to our west.
Rather high chances for showers and storms should continue until
Monday when high pressure should begin to redevelop aloft.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory from 9 PM this evening to midnight EDT
     tonight for NCZ107.
SC...Coastal Flood Advisory from 7 PM to 10 PM EDT this evening for
     SCZ054-056.
MARINE...None.

&&

$$

WHAT HAS CHANGED...TRA
KEY MESSAGES...TRA
DISCUSSION...TRA
AVIATION...TRA
MARINE...TRA