261
FXUS62 KILM 171406
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
1006 AM EDT Thu Jul 17 2025

.SYNOPSIS...
Bermuda High Pressure will remain off the coast through this
weekend. Temperatures will increase with a dangerous
combination of heat and humidity developing Friday through the
weekend. Widely scattered thunderstorms are possible through
Sunday with more widespread coverage by early next week as a
front drops south into the Carolinas.

&&

.UPDATE...
Morning convective activity has been a bit more widespread than
expected, especially the inland batch that dropped a quarter to
half inch from Cerro Gordo and Whiteville into southeastern
Bladen County. Visible satellite shows well-defined cumulus
cloud streets developing within this warm and very humid
airmass.

12z soundings from MHX and CHS show some mid level drying as
the offshore upper ridge builds westward, but it may not be
enough to prevent more scattered showers and thunderstorms from
bubbling up again today. 00z HREF hourly QPF ensembles didn`t
do a great job with this morning`s activity and show generally
dry weather continuing through the day. I`ll hold the forecast
closer to NBM probs which show 20 to locally 30 percent
coverage of showers and storms today. Heat indices may reach 105
degrees for an hour this afternoon but we`re saving the Heat
Advisories for what looks like a longer and more impactful heat
event starting tomorrow and lasting through the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure aloft over the western Atlantic will gradually drift
westward toward the southeastern US coast today and attempt to limit
widespread convection. Low level moisture advection out of the south
will maintain isolated to widely scattered showers this afternoon,
but these will be focused along an early afternoon sea breeze and
afternoon Piedmont trough. Disruption of the pressure gradient will
occur today as a cold front approaches the Mid-Atlantic states.
Southerly winds turn toward the SW late in the day, establishing the
Piedmont trough as the primary convective generation mechanism. This
slight veering of the wind will also set the stage for warmer
temperatures this weekend.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Increasing chance for dangerous heat Fri through the weekend.
Mid to upper ridge will be sprawled across the Southeast Fri
through Sat. Should see heights as high as 596 dam on Fri with
decent westerly flow above the sfc producing dangerous heat.
Models continue to show shortwave riding over the ridge into Fri
night over the NC/VA border area which could generate a bit
more convection to the north, but for our area, expect increased
subsidence and dry air aloft keeping limited convection across
the local forecast area. The ridge gets suppressed a bit to the
south and west on Sat and Sun which could lead to a bit of
shortwave energy to reach closer to the area. The SW to W flow
should steer any storms or debris clouds toward the coast and
should keep sea breeze pinned closer to the coast. Overall,
expect very hot and humid weather with better chc of convection
Sat and Sun, especially over northern tier of local area and to
the north. Highs will be in the mid 90s and will combine with
high humidity to produce heat indices likely reaching Heat
Advisory thresholds with Heat Warning possible in places Fri
through Sun.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Mid to upper trough should push frontal boundary south into the
Carolinas Sun night into Mon with possibly a low developing
along the boundary Mon into Tues. Looks like best chc of pcp
will be Mon as that frontal boundary drops south. By Tues the
best convection will shift southward over SC with high pressure
pushing in from the north. The mid to upper ridge starts
building up the Mississippi Valley Tues and builds eastward into
the Carolinas through midweek. This should lead to decreasing
chc of convection and warming again. Overall, temps will be
modified by clouds and pcp on Mon and closer to normal on Tues,
but should increase again through midweek as ridge builds back
in.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Land breeze showers along the coast will diminish over the next
couple of hours. A brief MVFR restriction is possible if these
showers approach a coastal terminal, but their isolated nature
should limit meaningful disruptions. Removed the PROB30 for
inland areas this afternoon as HREF guidance continues to be dry
and keeps most of the Piedmont trough activity west of I-95. S
winds turn SW during the afternoon with afternoon gusts up to 20
knots, especially near the coast. MVFR possible for coastal
terminals after sunset. Predominately VFR overnight with
elevated winds. Some stratus is possible, but tough to provide
confident details at this time.

Extended Outlook... Isolated showers and thunderstorms may bring
brief MVFR ceiling and visibility impacts Friday through Sunday,
mainly the afternoon and early evening hours. Coverage may increase
Monday as a frontal boundary approaches from the north.

&&

.MARINE...
Through tonight...Southerly flow today will veer during the
afternoon as a cold front pushes through the Mid-Atlantic
states. Some enhancement is expected near the sea breeze with
winds up to around 15 knots. Waves around 3-4 feet, primarily
wind-driven by diurnal circulations, with periods around 6 to 7
seconds. Showers and storms will continue to be isolated
overnight.

Friday through Monday...
Bermuda high and front pushing down into NC from the Mid
Atlantic will produce a SW to W flow across the waters Fri into
the weekend. As this boundary drops south and the high weakens,
winds will diminish closer to 10 kts or less through the
weekend into early next week. Winds should back each aftn in sea
breeze and spike up with seas generally 3 to 4 ft dropping to 2
to 3 ft over the weekend as winds drop. A longer period, around
8 second, swell will mix in.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ106-
     108.
SC...Beach Hazards Statement until 8 PM EDT this evening for SCZ056.
MARINE...None.

&&

$$

SYNOPSIS...ILM
UPDATE...TRA
NEAR TERM...21
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...21
MARINE...RGZ/21