Area Forecast Discussion
Issued by NWS Wilmington, NC

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547
FXUS62 KILM 170910
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
410 AM EST Fri Jan 17 2025

.SYNOPSIS...
High pressure with below normal temperatures to continue today.
Low pressure will bring milder temperatures and some rain back
to the Carolinas for the weekend. Arctic high pressure will then
return starting Sunday night with very cold temperatures
expected through the mid to late week period along with the
potential for some wintry precipitation during the Tue into
early Wed time period.

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure centered over the southern Appalachians this
morning will drift offshore during the afternoon.

Weak cold air advection early in the day will quickly erode as
southerly winds become established across the forecast area.
High temperatures will be similar to yesterday for most areas;
highs in the mid and upper 50s. Near the coast, onshore flow
will push cooler air from the frigid shelf waters onshore. Highs
in the lower 50s for coastal communities.

Clear skies throughout the day will become overcast this
evening. A shortwave aloft and developing low pressure over the
Lower Mississippi River Valley will advect warm, moist air
northward overnight.

A building gradient and strengthening low level jet will keep
a shallow mixed boundary layer near the coast. Low temperatures
tonight are expected to hold in the low to mid 40s along the
coast although mixing and increasing cloud cover could lead to
warmer temperatures. Cooler inland after a period of clear
skies just after sunset; overnight lows in the mid and upper
30s.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Southern stream s/w trof and associated sfc low to tap Gulf
moisture and low level Atlantic moisture Sat, resulting in
increased liquid rain chances since WAA leading into Sat will
result in temps breaking into the 50s Sat. 1st low books off to
the NE and well offshore Sat with a trailing broad low pressure
across the Carolinas. Will keep a rain threat Sat night into
Sun but POPs not as high as what will occur during the day Sat.
Most of the rainfall will occur Sat with 0.25 to 0.50 inches
possible, with the hier end of this range occurring closer to
the coast. Lows Sat night only in the 40s, with Sun highs again
in the 50s, both above the norm. Low chance Pops for showers
Sun ahead of the approaching strong cold/Arctic. Sun night is
when the fun begins. Look for the passage of the cold/Arctic
front followed by blustery conditions as CAA and a tightened sfc
pg combine. Large amplitude upper trof will expand across 1/2
to 2/3rds of the U.S. by late Sun night, reaching and pushing
all the way to the Gulf of Mexico. This will help drive that
1050+ mb Canadian Arctic south- southeastward across the U.S.
border, with its sfc ridge axis reaching the Carolinas by Mon
morning. Widespread low to mid 20s expected for Sun night lows
with wind chills upper teens to around 20.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
For Mon thru Wed, Southeast NC and Northeast SC will be
entrenched in Arctic air. Temps will run 15 to 20 degrees below
normal, possibly as much as 25 degrees below normal. Daytime
highs Mon thru Wed in the 30s, possibly not breaking above 32
for highs, especially Tue and Wed. Night-time lows, widespread
teens Mon night, Tue night and possibly again Wed night. Any
wind addition, will obviously make it seem colder. Thus,will
advertise in the HWO the threat for Cold Weather Advisory
conditions possible.

The threat for wintry pcpn has increased-some for the ILM CWA.
With various models, GFS, European and etc., having finally
started to come closer to some type of common agreement between
them. At this point, looking at early Tue into Wed morning as a
potential time-line for this Wintry weather threat. Low
pressure is expected to push out of the Gulf of Mexico, across
Fl and offshore by late Tue, then moving NE-ward, remaining
well offshore as it passes by the Carolinas Tue night and Wed.
With an Arctic airmass in place, this is 1 of the better
scenarios for Snow to occur across the ILM CWA. Models indicate
moisture from this low moving along the baroclinic zone will
reach into the Carolinas, possibly as far west as the I-95
corridor within the ILM CWA. As a result, POPs have been
adjusted upwards especially from the Coast to I-95. At this
point, will keep it mainly snow but bear in mind, if the low
tracks closer to the coast, then a wintry mixture may result
with some Gulf stream air influence. And if the storm track is
further offshore, no pcpn may result given the sharp moisture
gradient on the western side of this system. Arctic airmass to
remain with the FA going into Thu as an upper ridge axis pushes
to the FA but dry conditions to prevail.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
VFR tonight. West winds shift behind a cold front early this
morning. Light northerly winds and clear skies expected today.

Extended Outlook... Flight restrictions expected with rain and
a cold front this weekend. VFR returns with an arctic air mass
early next week.

&&

.MARINE...
Through Tonight...Transient high pressure will move offshore
today. Northerly winds this morning will shift throughout the
day, becoming southeasterly this afternoon and southerly
overnight. A poor gradient and inefficient mixing will keep
winds light through Saturday morning. Gusts could reach 15-20
knots near the outer boundary of the relevant forecast zone (20
nm). Seas around 3-4 feet this morning become 1-2 feet this
afternoon.

Saturday through Tuesday night...Light S to SW winds Sat thru
Sat night with ongoing WAA however with the cold SSTS near
shore, the best S-SW winds will remain elevated across the local
waters. Sun, the sfc pg tightens late somewhat, with increasing
SW winds to around 15 kt g20 kt possible. Seas will slowly
build across the waters Sat thru Sun, more-so from the hier
waves bleeding into the local waters from offshore given the
better/stronger winds offshore where SSTS likely in the 60s+.
CFP Sun night, with excellent CAA(Arctic air) and notably drier
air under strong and gusty NW flow overspreading the waters.
Could see SCA conditions as a result. For Mon thru Tue night,
look for winds to become Northerly at SCA threshold speeds at
times, especially during the potential winter wx event Tue into
Tue night. Reduced vsby to 1 nm or less possible in wintry mix
of pcpn Tue/Tue night.

&&

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

&&

$$

SYNOPSIS...ILM
NEAR TERM...21
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...21
MARINE...DCH/21