349
FXUS62 KILM 171838
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
238 PM EDT Sun Aug 17 2025

.SYNOPSIS...
Dry high pressure will shift eastward as another area of high
pressure builds down behind a weak backdoor cold front through
Monday. Erin is expected to remain far enough offshore to keep
substantial wind and rain impacts away, but will bring dangerous
surf to the beaches for much of the work week. Rain chances
increase late in the week as a cold front stalls south of the
area and moisture increases.

&&

.NEAR TERM /THROUGH MONDAY/...
Dry high pressure will be displaced farther east and south as
another area of high pressure builds down from the north behind
a weak backdoor cold front. At the same time, a lingering
boundary to the south will keep any shower activity south of our
local forecast area through early Mon. Low dewpoint air and
overall dry column with pcp water values down less than 1.5
inches spread southward today but will see this airmass gets
squeezed out as high pressure well north builds southward
pushing a weak backdoor cold front south. Should see afternoon
cu build ahead of this front Mon aftn with pcp water values
increasing up near 2 inches inland. As sea breeze front pushes
inland Mon aftn, should see best convergence lined up along or
west of I-95 corridor with convection developing there. The
coast should remain drier.

With clear skies and calm winds tonight, look for temps to
quickly drop this evening with lows down to 70 to 75 most
places. Highs Mon should top 90 once again with heat index
values up around 100 inland where some moisture recovery will
occur.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
Key Messages/Highlights:
*Generally below normal rain chances
*Very low flash flood/severe storm risk
*Near normal temperatures

Confidence:
*Moderate to High

Details: High pressure will prevail with mainly dry weather and
seasonable temps. Still watching Hurricane Erin closely which is
forecast by the NHC to be well east of the northern FL east coast
early Wed AM. Will start to see a slight tightening of the pressure
gradient across the area Tue night as Erin draws closer but no
significant winds are expected.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Mid-upper troughing is progged to dig southward into the
western Atlantic on Wednesday, aided by a shortwave trough
diving southeastward from Ontario on Tuesday night. Although
ensemble guidance for Hurricane Erin still shows some across-
track spread, the overwhelming majority of the guidance agrees
on a northward turn and a pass between NC and Bermuda that keeps
any substantial wind and rain impacts offshore, with the
closest approach expected late Wednesday or Wednesday night.
High surf and dangerously strong rip currents remain the most
significant hazard, lasting for most of the work week.

A "cold" front is expected to slide through on Wednesday night as
Erin passes by and begins to depart, with winds turning north to
slightly west of north. In addition, moisture aloft should
temporarily decrease behind the front on Thursday in tandem with
the strong subsidence around Erin, before increasing again on
Friday. Ultimately, this front should stall south of the area as
steering flow aloft weakens. Otherwise, confidence remains low
for the late week and weekend as the pattern evolves in the wake
of Erin. In general, precip chances are expected to increase
with a corresponding decrease in high temps, but whether this
follows a typical diurnal trend of afternoon/evening convection
which dissipates overnight or waves of showers and storms not
necessarily timed with afternoon heating remains to be seen.

High temperatures are expected to hold near-normal (upper 80s
to around 90F) ahead of Erin before trending slightly below
normal (mid- 80s) over the weekend as increasing precip coverage
should keep the sun at bay. Lows will depend on how dew points
evolve, but low-mid 70s are generally expected each night.

&&

.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
Expect VFR with light and variable winds through the period.
Essentially, very light NE winds will become light southerly
into Mon morning before quite variable as high pressure builds
down behind a very weak backdoor front later on Mon. Very low
confidence for any fog, but if there will be any, it would be at
FLO, but dewpoint depression seems too large for fog. Included
some aftn Cu around 4k for FLO, but terminals should see more in
the way of aftn Cu on Monday aftn, but should be just after
this TAF period.

Extended Outlook...Predominantly VFR outside of periodic daily
early morning fog/low stratus.

&&

.MARINE...
Through Monday...Dry high pressure extending in from the
northeast will be remain over the coastal waters on Mon as weak
low remains to the east with a weakening boundary trailing to
the southwest. Overall, expect light northerly flow becoming
more east to southeast tonight, mainly controlled by land/sea
breeze through Mon. Very long period swells from Erin in the
distant Atlantic will reach into the local waters starting Mon
with seas increasing toward the end of the day. Seas Mon should
remain in the 2 to 4 ft range with sharp increase thereafter.

Monday night through Friday...High pressure will prevail with
Tropical Cyclone Erin likely passing to the north well offshore mid
week. Winds/seas are expected to start increasing Monday night when
swells from Erin lead to 6+ foot seas and we have raised a Small
Craft Advisory through Thu as a result due to high confidence.
Significant wave heights up to around 13 ft are possible, mainly off
Cape Fear. Winds/gusts should mostly stay 25 kt or less, although
confidence is lower in wind speeds as much depends on the proximity
of the storm and resulting pressure gradient.

&&

.TIDES/COASTAL FLOODING...
Through midweek, minor coastal flooding is expected along the
Lower Cape Fear River during the late afternoon and evening high
tide cycles, basically within a 3 hour window centered on high
tide.

Runup from large waves associated with Hurricane Erin, could
result in minor coastal flooding, beach erosion and minor ocean
overwash across vulnerable coastal locations such as areas
without a protective dune line.

RIP CURRENTS: A high risk of rip currents is likely as early as
Monday and continuing into Friday as large swells impact the coast
from Hurricane Erin well offshore.

HIGH SURF: Rough surf with 6+ foot breaking wave heights is also
expected as early as Monday night north of Cape Fear and Tuesday
through Thursday for much of the SE NC and NE SC coast, especially
for east-facing beaches.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory from 4 PM this afternoon to 7 PM EDT
     this evening for NCZ107.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
NEAR TERM...RGZ
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...RGZ
MARINE...RJB/RGZ
TIDES/COASTAL FLOODING...ILM