National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 191355
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
955 AM EDT Fri Apr 19 2024

.SYNOPSIS...
Rain chances increase today as a cold front moves across the
area. The front stalls in the area for the weekend, maintaining
elevated rain chances. High pressure next week leads to drying
conditions once more, with a gradual warming trend.

&&

.UPDATE...
-- Changed Discussion --
Tweaking visibility grids a bit but main impacts are to
TAFs...public fcst grids still holding up quite well.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
A cold front currently just to our north will push down and stall in
the area through the day, enhancing our potential for storms. As the
ridge axis aloft moves offshore a trough with a surface cold front
will approach from the west. Ahead of this feature, pockets of
vorticity will move overhead. Instability from daytime heating with
the stalled frontal boundary will lead to scattered activity
developing in the afternoon. Inverted V soundings suggest a
potential wind threat with any stronger storms` downdrafts along
with the possibility for a small hail threat. The majority of the
area is in a marginal (threat 1 of 5) risk for severe weather
outside of coastal SE NC where there`s more inhibition. As the cold
front to the west approaches overnight, the lack of instability will
cause precip with it to become isolated in coverage. This activity
will move offshore before daybreak Sat as the cold front moves
through. Highs in the mid to upper 80s away from the SE NC coast.
Lows in the mid 60s.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Cold front in the area Sat morning gradually slips offshore during
the day, ending up parallel to the flow aloft in the evening. Rain
chances Sat will depend heavily on how quickly the front moves
offshore. If the front pushes offshore before midday, drier mid-
level air will work its way into the area, significantly limiting
rainfall chances. The post front environment is marked by a strong
inversion based around 850mb. Even isentropic lift is negligible
post front. The best chance for getting rain will be along the
coast, if a sea breeze can develop and help bring some of prefrontal
air back onshore. Confidence in rainfall Sat is lower than normal
due to the limiting factors mentioned above. Temperatures continue
well above climo Sat regardless of where the front is with no
cold air to be found. Highs will ranges from upper 70s on the
cold side of the front and lower 80s on the warm side.
Temperatures do start trending closer to climo late Sat night as
the front begins to slip farther south and a northerly flow
regime moves in.

Frontal zone lingers in or just south of the area Sat night through
Sun night. Weak surface waves develop along the front then start to
deepen as they feel the influence of a southern stream shortwave
crossing the Gulf Coast. Increasing moisture Sat night and
increasing mid-level lapse rates as heights start falling will lead
to elevated convection developing over coastal SC Sat night then
moving northeast in NC after midnight. The lows pass offshore later
Sun and Sun night with the location of the front determining how
close the lows are to the forecast area. The strength of the lows
and their proximity to the coast will determine how much rain ends
up falling, but rain seems all but certain. There is likely to
be a sharp rainfall gradient in or near the forecast area. Cloud
cover, rain and increased northerly flow on the west side of
the aforementioned lows will keep highs Sun well below climo
while lows end up near climo.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Low confidence right away Mon as a robust, moisture laden shortwave
moves across the forecast area. Hard to imagine this feature won`t
bring at least some isolated showers to the area, and the guidance
is split on location and timing of this feature. Would not be
shocked to see cloud cover and rain chances increase with further
updates. Flow aloft flattens in the wake of the exiting shortwave
Tue through Thu, leading to fast moving surface features and keeping
coldest air north of the area. High pressure moves overhead Tue then
offshore Wed as dry cold front moves across the area. High pressure
with Canadian origins then settles over the area Thu. Temperatures
will be on a roller coaster next week with well below climo temps
Mon/Mon night trending close to climo Tue/Tue night and above
Wed before dropping back near to below climo late in the week.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
A IFR/LIFR cloud deck is making its way through SE NC at this
time, over KILM. Timing for KLBT/KCRE/KMYR will be around 12Z,
but at the same time sunrise should start to scatter out this
stratus and restrictions should be brief. Then the afternoon
will see scattered thunderstorm activity with restrictions hard
to pin down. Another possibility is stratus at the coastal
terminals due to sea fog, but low confidence with this as well.
A cold front will move through near the end of the TAF period
with winds coming around to the NW.

Extended Outlook... Restrictions possible through the weekend due
to daily shower chances from a stalled front. High pressure
building in late Mon into Tues should return dominant VFR.

&&

.MARINE...
Through Tonight:
Sub-SCA conditions. A stalled front in the area will increase
shower and storm chances this afternoon with the possibility for
strong wind gusts. Another cold front from the west will move
over the waters overnight into Sat morning. Wind direction with
the competing boundaries will be a bit tumultuous, going from
the E this morning to more SE in the afternoon and then SW
overnight. Speeds should be near 10 kts. Seas will be 2-3 ft
with a 1ft E swell at 12-14 seconds, a 1-2 ft SE well at 8-9
seconds, and a NE to SW wind wave.

Saturday through Tuesday:
Brief period of southerly flow on Sat before front sags south
of the waters and high pressure starts building in from the
north Sat night. North to northeast flow will continue through
Tue with potential for northeast winds in excess of 20 kt at
times Sun night and Mon as low pressure passes east of the
waters. Northeast surge Mon night into Tue may bring about
another round of winds in excess of 20 kt late Mon night before
speeds drop down near 10 kt Tue. Seas build from 2-3 ft Sat to
3-4 ft Sun and 3-5 ft Sun night and Mon. Continued strong
northeast flow will keep seas 3-5 ft Mon night before seas
gradually start to diminish on Tue. Initially a southerly wind
wave and a southeast to east swell will be present, but the
development of enhanced northeast flow will lead to an easterly
wind wave becoming dominant on Sun and persisting through Tue
with wave periods gradually increasing.

&&

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

&&

$$

SYNOPSIS...ILM
UPDATE...LEW
NEAR TERM...LEW
SHORT TERM...III
LONG TERM...III
AVIATION...LEW
MARINE...III/LEW