157
FXUS62 KILM 050040
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
840 PM EDT Fri Jul 4 2025

.SYNOPSIS...
A weakening front remains offshore tonight. Rain chances
increase this weekend as stalled low pressure south of the area
starts to move north later in the weekend. More typical summer
time weather returns next week.

&&

.UPDATE...
Minor updates made to POPs over the next couple hours around
I-95 as isolated to scattered convection continues. Updated
aviation discussion below.

&&

.NEAR TERM /THROUGH SATURDAY/...
Mid level dry air has mixed into the boundary layer today as evident
by most stations having a 3-5 degree drop in dewpoint (less so along
the Grand Strand).  This doesn`t bode super well for convective
coverage on this highlighted day characterized by outdoor
celebrations aplenty but our 20-ish POPs seem hard to argue with.
Later on tonight focus shifts to the system off the coast. Of course
the center and thermal structure of the storm are only just now
behind investigated by aircraft but models are in good agreement
that rain should start to affect the coast towards daybreak
Saturday, spreading gradually into inland zones as the day wears on.
The widespread clouds and rain will keep inland locales near normal
whilst coastal locales stay in the onshore flow around the low.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
Period will be unsettled with deep tropical moisture spreading over
the region Friday night and lingering well into next week. Weak low
currently off the northeast FL coast will slowly move north Sat
night. The low`s northward progress was held up by high pressure to
its north, but the high slips east later Sat, opening the door. Main
concern with the system will be strong rip currents/dangerous surf
conditions and potential for heavy rain anytime Sat night through
Sun night. The heavy rain timing remains in question and is a
function of when the low actually starts moving north. The guidance
the last few days has been consistent with the environment the low
will bring with it. Precipitable water 2.2-2.4", warm cloud layer on
the order of 16k ft deep, and decreasing storm motion as the
center of the low moves across or just west of the forecast area.

All of this points to potential for periods of very heavy rain.
Soils are on the dry side and rivers are lower which should help
limit the flooding threat to a point. A good example was the storms
Wed evening which dropped 5-6" of rain in a short period of time
across parts of the forecast area. Only very minor flooding was
reported with this event, showing the current conditions can take
heavy rain. The caveat would be multiple storms affecting urban
areas in rapid succession and/or a focused band leading to rainfall
amounts in excess of 6" in a short period of time. Again, not
something that would happen on a large scale, but would be possible
on a localized scale. Still a lot of uncertainty with any rainfall
impact given timing and location unknowns. The threat exists, but
does it exist for the local area? Further forecast refinements will
answer that question.

Have much higher confidence in potential for strong rip currents and
dangerous surf conditions through the end of the weekend.
Temperatures below normal Sun given plenty of clouds and potential
for periods of heavy rain. Lows will run above normal.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Work week begins with remains of low on the verge of exiting the
local area to the north. The low trails a weak trough, the remains
of a front, which ends up lingering in the area through Tue before
dissipating. The sea breeze does make the boundary much harder to
find Mon and Tue afternoon, but it will help with convective
initiation each day. Weak mid-level ridging will not be enough to
suppress storms Mon/Tue and expect to see diurnal storm coverage
slightly higher than the typical 30-40%, given the presence of the
boundary and abundant moisture, precipitable water remains over 2"
Mon and Tue even as the low departs.

Coverage is likely to increase during the middle to later part of
the week as the weak ridging is shunted south by 5h trough moving in
from the northwest. The trough is not particularly strong, but it
will drop 5h temps enough to increase mid-level lapse rates.
Precipitable water remains north of 2" through the end of the week
and while cloud cover will limit afternoon temps a bit, there will
still be plenty of surface based instability and a weak sea breeze.
Deep warm cloud layer, tropical moisture and storm motion 5-10 kt
Mon-Wed would suggest the possibility of heavy rain being an issue
IF the same areas are affected by storms multiple times a day and
day after day. Not worthy of any mention outside of the AFD at this
point, but something to watch. temperatures near to slightly above
normal during the day and above normal at night.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
Periodic MVFR/IFR possible in scattered convection moving
through for the rest of this evening, with impacts primarily at
KFLO/KLBT and perhaps KILM. Otherwise VFR through most of
tonight with MVFR at coastal terminals towards the morning. Rain
chances will increase in the afternoon as well.


Extended Outlook...Predominantly VFR. Early morning fog and/or low
stratus will be possible each morning as low-level moisture remains
plentiful, especially near the coast. Otherwise, transient MVFR
restrictions due to showers and storms become possible each day over
the weekend and into early next week due to offshore low
pressure.

&&

.MARINE...
Through Saturday...
E to NE winds will be in place, with the former becoming more
predominant hinging upon the still unknown evolution (and
thermal structure) of the low developing off the coast. This
could lead to a slight increase in period as the fetch length
grows a tad longer. The bigger story however will be the
building of the shorter period wind waves. SCA could have been
raised this shift starting Saturday but given the uncertainty
regarding possible tropical headlines soon neighbors and I have
decided to wait one forecast cycle, if not address during any
evening update.

Saturday Night through Wednesday...
Treacherous marine conditions Sat night continue for much of
Sun before gradual improvement as wind speeds decrease. More
typical summer time pattern sets up Mon-Wed with Bermuda High
offshore and inland trough in the wake of the departing low.
Southerly flow peaks around 15 kt each afternoon then drops back
to 10 kt overnight. Seas will steadily decrease in response to
the weakening winds, stabilizing around 3 ft Tue and Wed. Seas
will be a mix of a southerly wind wave and a southeast swell
with the southeast swell becoming more noticeable later in the
week.

&&

.TIDES/COASTAL FLOODING...
Other - Rip Currents: Increasing south-southeasterly fresh swell
with wave periods averaging 7 seconds should feed onto the beaches
Saturday in advance Tropical Depression Three. This wave group
should produce a high risk of rip currents at the South Carolina
beaches and a moderate risk elsewhere. Conditions should deteriorate
further Sunday as the tropical system approaches landfall on the
southern South Carolina coast when breaking wave heights in the surf
zone could approach 6 feet south of Cape Fear.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...Tropical Storm Watch for SCZ054-056.
     High Risk for Rip Currents from 6 AM EDT Saturday through Saturday
     evening for SCZ054-056.
MARINE...Tropical Storm Watch for AMZ252-254-256.
&&

$$

SYNOPSIS...ILM
UPDATE...LEW
NEAR TERM...MBB
SHORT TERM...III
LONG TERM...III
AVIATION...LEW
MARINE...III/MBB
TIDES/COASTAL FLOODING...