Watha, North Carolina Weather Forecast Discussion

184
FXUS62 KILM 261815
AFDILM
Area Forecast Discussion
National Weather Service Wilmington NC
215 PM EDT Fri Sep 26 2025
.SYNOPSIS...
An approaching cold front will bring good chances of showers
and thunderstorms this weekend. A tropical cyclone should
develop over the Bahamas this weekend and could bring impacts to
the Carolinas as early as Monday. Increasing winds and rough
seas will develop offshore but inland impacts including heavy
rain and wind are less certain. Drier and cooler weather should
develop late next week as Canadian high pressure builds in.
&&
.NEAR TERM /THROUGH SATURDAY/...
Satellite and surface observations indicate a surface front remains
stalled across the western Piedmont with south to southwesterly
winds present across much of SC into southern and eastern NC. A deep
trough in the jetstream was observed digging into the northwestern
Gulf with a closed circulation visible over southwestern TN. This
closed low is expected to drift southeastward while the broader
trough around it pivots into a north-south orientation on Saturday,
centered over the Deep South into the Mid-South. This will push the
stalled front closer to the coastal plain and support scattered to
numerous showers and thunderstorms on Saturday, mainly from midday
onward. As for today, scattered showers and storms should still
manage to develop amidst an abnormally hot and humid airmass with a
primary focus along the sea breeze which should tend to track
northwestward with time this afternoon, but these should gradually
wane in coverage this evening as heating abates.
Tonight, as the mid-level trough shifts eastward and some impulses
aloft begin to impinge on the area, some hi-res models suggest
isolated to scattered showers and storms may develop during the
latter half of the night and track south to north, feeding on
unstable air over the ocean. Cloudiness, showers, and warm dewpoints
will limit low temps to the upper 60s to low 70s. Any early morning
showers or storms should tend to weaken or dissipate around or after
sunrise, with a lull during the morning before daytime heating helps
new showers and storms develop by late morning and continue through
the day. With precipitable water values around 1.9-2.1", locally
heavy rainfall is certainly possible, and localized flash flooding
cannot be ruled out in typical problem spots. High temps will be
heavily muted by clouds and showers, so upper 70s to low 80s are
forecast.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
A shortwave trough across the southern Appalachians should get
trapped south of a ridge building across the Great Lakes. Its
vorticity will get smeared out south of the ridge and begin to
retrograde by Sunday night back to the west across Tennessee. At
the surface a cold front should push offshore Saturday night,
stalling Sunday and becoming more diffuse with time as the outer
reaches of the low level cyclonic flow around what could be
Tropical Storm Imelda in the Bahamas approaches the Carolinas
from the south.
A deep flow of tropical moisture from the Gulf should push east
across the Carolinas Saturday and Saturday night, exiting all
but the Cape Fear area by Sunday morning. Precipitable water
near 2.0 inches Saturday night will linger across Cape Fear
Sunday, but inland portions of the Carolinas should see
precipitable water fall to 1.3 to 1.6 inches. While lapse rates
should remain sufficiently steep to support scattered showers
and maybe even some thunderstorms, inland coverage of
convection may be lesser than was thought yesterday with drier
air aloft. High chances for showers and thunderstorms will
continue closer to the coast, especially across the Cape Fear
area.
The eastern Carolinas could enter a lull in rain Sunday night as
the front becomes essentially washed out, but Imelda is still
too far away for any direct impacts yet. Weekend temperatures
should run considerably cooler than most of this week saw with
clouds and showers keeping highs in the lower 80s. Overnight
lows should range from the upper 60s to near 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Models remain split this afternoon between the camp wanting to
bring Imelda onshore across South Carolina or southern North
Carolina versus those that show it captured by the larger
circulation around Hurricane Humberto well offshore. The
difference in sensible weather between these two scenarios is
huge, and it`s still too early to know which camp will
ultimately turn out to be correct.
Erring on the side of caution would base the forecast on a
landfalling tropical cyclone scenario. This idea would suggest
gradually increasing rain and wind over eastern South Carolina
during the day Monday culminating in a landfall sometime Monday
night into Tuesday with tropical storm or perhaps category 1
hurricane conditions experienced along the South Carolina coast
northward to Cape Fear. This idea is based on models like the
12z GFS and the bulk of hurricane-specific high-res models like
the HWRF, HMON, and HAFS family, and would bring heavy rain and
possible flooding, storm surge, and a risk of tornadoes. An
alternative scenario, as shown by the 12z Canadian and several
recent runs of Google`s Deepmind AI model, shows Imelda moving
more slowly toward the South Carolina coast Tuesday, missing the
connection with the southeasterly steering flow associated with
the inland shortwave beneath the Great Lakes ridge, and getting
pulled eastward by Hurricane Humberto without a landfall.
We`ll likely gain forecast confidence once a well-defined center
develops Saturday within the tropical disturbance and it
becomes clearer how quickly the system will move northwestward.
Faster movement will increase the chances the system will take
advantage of the onshore steering flow present Monday night into
Tuesday.
Beyond Imelda, strong high pressure should build southward
across southeast Canada Wednesday through Friday, likely pushing
a surge of northeasterly winds and drier air across the
Carolinas. This could herald the start of an extended period of
breezy winds with GFS soundings suggesting 25-30 knot gusts
Wednesday and 35-40 knots on Thursday. Breezy northeast winds
could continue into Friday as well. Highs through the period
should stay in the 70s except around 80 on Tuesday. Lows
generally in the 60s may fall into the 50s late in the week as
Canadian air arrives.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
VFR conditions across the area should continue to dominate through
early tonight, except for brief vis/cig restrictions in a passing
shower or storm. High dewpoints, light or calm winds, and mostly
clear skies after dark should support the development of mist/fog
and low cigs, especially inland, later tonight. Guidance tools are
mixed in how much precip may develop overnight, and this limits
confidence in the extent and magnitude of restrictions, especially
near the coast. At least isolated showers and perhaps a storm
should develop over the ocean and track northward, potentially
impacting a terminal, late in the night. Cloud cover associated
with this precipitation may limit vis restrictions, but if no
precip or cloud cover occurs, then restrictions may end up worse
than presently forecast. Otherwise, restrictions should
gradually lift/burn off during the morning, with renewed showers
and storms developing around midday with them scattered to
numerous in coverage.
Extended Outlook...Showers and thunderstorms will create periods of
MVFR to local IFR conditions in ceilings and low visibility
throughout the weekend. There is a low, but growing potential that a
tropical cyclone may impact the eastern Carolinas Monday into Monday
night with strong wind, low ceilings, and low visibility in heavy
rain.
&&
.MARINE...
Through Saturday... High pressure well offshore will maintain light
(mainly 

NWS ILM Office Area Forecast Discussion