697
FXUS62 KILM 041813
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
113 PM EST Thu Dec 4 2025

.SYNOPSIS...
High pressure to the north will keep temperatures below normal
for quite some time while low pressure along a frontal boundary
well to our south brings an unsettled weekend. Even colder but
drier air builds in on Monday.

&&

.NEAR TERM /THROUGH FRIDAY/...
Although a rarity in the La Nina climate pattern we`re in, a
moisture laden subtropical jet extends from the Pacific across
northern Mexico and over the southeastern United States this
afternoon. A multitude of shortwaves embedded with the subtropical
and polar jets are already inducing surface low pressure to develop
along a stalled front near the Gulf Coast. This low should move
eastward tonight, jumping across Florida Friday morning, and work
its way northeastward off the SC and NC coast Friday afternoon.

Visible satellite already shows a large zone of upglide over the
front as tropical moisture is lifted over the cool dome in place
over the Deep South. Rain produced via deep isentropic lift should
spread northeastward across the eastern Carolinas after midnight
tonight (70-90 percent chance) leading into a complete washout on
Friday with 100 PoPs and QPF ranging from 0.5 to 1.0 inches.

Forecast lows tonight should fall to 40-45, warmest along the SC
beaches. With dense clouds and rain Friday highs will only warm into
the mid-upper 40s inland and some lower 50s along the immediate
coast. This appears Friday will be the middle of at least a 10-day
period of sustained below normal temperatures across our portion of
the Carolinas.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
Steady rain from the near term to carry over into the start of the
short term. Forecast soundings show impressive entire-column
saturation. Normally this is supportive of heavy rain potential but
the forcing for ascent is quite weak, the current forecast and it
looks like most areas will average 0.25" of rain (despite PW values
being 1.25"). Saturday`s forecast is a bit less straightforward.
Models do show the rain getting shunted slightly southward and
yet forecast soundings still show an entirely saturated
troposphere. POPs and QPF will both show a gradient from north
to south but I think this could be optimistic and that most
areas will continue to be quite unsettled as the mid level flow
doesn`t appear to support the aforementioned southern shift.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Sunday now offers the same forecast problem as Saturday and that is
does the deep layer moisture really have any impetus to push
southward. The current NBM-based forecast shows as such but the 12Z
GFS still looks pretty wet (and by wet I still mean good rain
chances as opposed to heavy rain). Forecast confidence then
increases on Monday as a healthy trough finally drives the front and
it`s moisture southward ahead of what will wind up being a chilly
1035 mb high in the OH Valley. This airmass winds up offshore by
Wed/Thu which should allow for a return of more seasonable
temperatures. This could also favor the development of a coastal
trough for some clouds and minor rain chances but the forecast
remains dry at this time.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Thickening mid level clouds will overspread area this afternoon in
advance of a developing storm system along the Gulf Coast. Rain
should arrive from the southwest between 05z-10z Friday. As
precipitation intensity increases, ceilings should fall below 1000
feet with widespread and long-lived IFR ceilings anticipated to
develop by 11-13z Friday. MVFR visibility in moderate rainfall could
occasionally dip to IFR (1-2 miles) during heavier periods of rain
during the day.

Extended Outlook...Widespread and prolonged IFR ceilings should
continue through Friday night into Saturday. There is some model
support for improving aviation weather conditions late Saturday
night into Sunday, however a chance of MVFR/IFR ceilings will
continue from Sunday into Monday as an unsettled weather pattern
remains along the Southeast coast.

&&

.MARINE...
Through Friday...Low pressure developing along the Gulf Coast today
will cross Florida Friday morning and then move along the edge of
the Gulf Stream off the Carolina coast Friday afternoon. Light winds
tonight should turn northeasterly Friday morning as the low jumps
east of the Florida peninsula.

There`s actually a pretty wide range of model projections for wind
speeds: the 12z NAM and HRRR are among the strongest models and show
the potential for up to 6 hours of 20 knot winds Friday, while
others like the 12z GFS and 00z ECMWF keep winds 10 knots or less. A
compromise solution is for 10-15 knots during the day Friday which
should increase seas to near 3 feet in a mix of 10-second easterly
swell and local wind waves. Widespread rain Friday could knock
visibility down to 3 miles or less at times.

Friday night through Tuesday... Frontal boundary stalled south of
the waters early in the period keeping northerly wind component
dominant, though a weak pressure pattern along with waves of low
pressure running along the boundary will lead to oscillations from
NW to NE. The front will also keep the gradient light offshore
keeping any swells from developing and local waves will tend to be
shorter in period. This whole setup doesn`t change appreciably
until Monday. A healthy trough will form a deeper low on the
front pushing it further offshore and paving the way for a
strong area of high pressure to start building in from the NW.
Seas will build to advisory levels while winds grow close but
generally fall short.


&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
UPDATE...ILM
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...TRA
MARINE...ILM