894
FXUS62 KILM 241845
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
245 PM EDT Sat May 24 2025

.SYNOPSIS...
Low pressure moving across the Mid South will lift a front
across the Carolinas, bringing periods of showers and thunderstorms
late Sunday through Monday. The front should dip south on Memorial
Day, but return north again Tuesday bringing another period of
wet weather into Wednesday. Temperatures should return to normal
late in the week with showers and storms becoming more isolated.

&&

.NEAR TERM /THROUGH SUNDAY/...
Progressive flow aloft is pushing a weak surface high across the
Carolinas today, which will move off the coast early this evening. A
weak surface trough will approach the area after midnight, with
guidance mixed on how far south it will progress. Short-range
ensemble suggests it will make it to near a FLO-ILM line by 12Z
Sunday before lifting north. Moisture will increase west to east
through the day, and interaction with this boundary will lead to
scattered showers, with the possibility of thunder during the
afternoon. Best chances for precip during the daytime hours Sunday
should occur over our SC zones, where PoPs will increase to 50-60%
after 18Z.

Lows tonight will fall to around 60, with highs Sunday ranging from
around 80 north, to lower 80s Georgetown and Williamsburg
counties.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
An extended period of unsettled weather that begins Sunday will
persist through at least the middle of the week. An active
southern branch of the jet will bring a series of low amplitude
disturbances across the Carolinas. Streamlines at 850 and 700 mb
point back to the Gulf which should advect deep moisture
overhead with precipitable water values peaking near 1.80 inches
early Monday and again late Tuesday.

The surface pattern Sunday night will feature a front stalled
across central North Carolina. A wave of low pressure rippling
eastward along the front should help organize a large area of
showers with embedded thunderstorms Sunday night. The low is
expected to reach the NC coast Monday morning, pushing the front
south all the way to the FL/GA state line by Monday night.
Forecast PoPs as high as 70 percent Sunday night into early
Monday will accompany this frontal wave.

Enough subsidence should follow the low after it exits the coast
to bring a period of mainly dry (but still mostly cloudy) weather
late Monday through Tuesday morning. However the next subtle
disturbance approaching from the west should begin to lift the
front back to the north again Tuesday afternoon into Tuesday
night. Another surge of showers with embedded thunderstorms
should develop across the area with forecast PoPs again surging
to 70 percent.

Diurnal temperature ranges will be constrained by the clouds
and periods of rain with highs expected to remain in the 70s
both Monday and Tuesday. Monday night`s lows could dip into the
upper 50s away from the beaches, with 60s expected otherwise
through the period.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Model spread increases considerably by Wednesday concerning the
timing of arrival of the next wave of low pressure. Among
current models the GFS seems to be the preferred solution
bringing the low across the area and off the coast during the
day Wednesday. Last night`s 00z ECWMF and the newer 12z were
both slightly slower, but today`s 12z Canadian is considerably
slower than both. I`m maintaining high PoPs (70 percent) through
Wednesday morning, then ramping down to 30-50 percent Wednesday
night.

There is considerable uncertainty with Thursday`s forecast.
Rainfall should become more scattered and diurnal in nature
without the focusing of the old front nearby. West-southwesterly
winds from 850-500 mb and the likely continuation of subtle
upper disturbances rippling overhead will likely ignite
scattered batches of showers and thunderstorms, but timing is
very difficult at this extended time range. Highs should return
to the mid 80s with some more sunshine expected with lows
generally in the mid to upper 60s.

There`s broad consensus that the next cold front will arrive on
Friday, accompanied by 30-40 percent chance of showers and
thunderstorms. Ensemble spread becomes such that I`m
maintaining small PoPs for diurnal convection next Saturday
given uncertainty in the surface and upper pattern by then.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
High confidence in VFR conditions through 12Z Sunday as weak high
pressure slides across the area and offshore. A weak trough will
approach KILM and KLBT late tonight, then lift north Sunday morning.
Widely scattered showers will develop Sunday morning across the
southern zones with possible MVFR impacting KFLO/KMYR/KCRE.
Convection will spread north through the day, with chance for MVFR
conditions increasing for KLBT and KILM during the afternoon.

Extended Outlook...A stalled front just south of the area, will
return north next week bringing moderate to high potential for
periodic MVFR/IFR conditions in ceilings and reduced vsby from pcpn.
At this time there are two windows that appear most susceptible for
aviation impacts: Sun night into Mon morning, then again Tue night
into Wed morning.

&&

.MARINE...
Through Sunday...High pressure building across the waters from west
to east this afternoon will yield light winds, which will veer from
ENE to ESE by this evening. A weak surface trough will approach from
the north overnight and is expected to make it to near Cape Fear by
12Z Sunday before stalling and returning north. Winds on the north
side of the boundary will become northerly, though speeds will
remain light. Although there is uncertainty on how far south
the wind shift will make it, SSE winds should increase to 10-15
kts across all waters by early Sunday afternoon. Shower and
thunderstorm activity will be minimal early in the day, with
chances increasing during the afternoon.

Sunday Night through Thursday...An extended period of unsettled
weather will begin Sunday evening and last through at least the
middle of the week. Weak low pressure moving along a front
stalled across North Carolina should bring waves of showers and
thunderstorms across the area Sunday night. As the low moves off
the NC coast Monday the front will get a kick southward and
should stall near the FL/GA state line Monday night. A period
of breezy northeast winds should develop along the Carolina
coast during the day Monday and last into Monday night, possibly
reaching 20 knots at times. Given the large number of mariners
anticipated to be active Monday, the wind and subsequent choppy
waves could be rather impactful.

Low pressure moving northeastward through the lower Mississippi
Valley on Tuesday will begin to pull the stalled front northward
again, likely veering our winds southeasterly by late Tuesday
afternoon, then southerly by late Tuesday night as the front
returns to the area. Models paint a variety of possible
locations for where the surface low could track but most are
far enough inland to maintain southerly winds across the area
Wednesday into Wednesday night. The front`s arrival will likely
be preceded by another period of showers and thunderstorms
Tuesday night into Wednesday morning.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory from 6 PM to 11 PM EDT this evening for
     NCZ107.
SC...Coastal Flood Advisory until 8 PM EDT this evening for SCZ054-
     056.
MARINE...None.

&&

$$

SYNOPSIS...TRA
NEAR TERM...CRM
SHORT TERM...TRA
LONG TERM...TRA
AVIATION...CRM
MARINE...TRA/CRM