668
FXUS62 KILM 092027
AFDILM

Area Forecast Discussion...corrected synopsis
National Weather Service Wilmington NC
427 PM EDT Sun Mar 9 2025

.SYNOPSIS...
Low pressure moving along the Gulf Coast tonight into Monday
will strengthen as it passes off the Carolina coast Monday into
Monday night. Periods of heavy rain will be possible, especially
Monday and Monday night. The low will be followed by dry air and
temperatures above normal for the upcoming week.

&&

.NEAR TERM /THROUGH MONDAY/...
Deep low pressure will move up from the Gulf coast tonight through
Mon reaching the SC coast around sunset on Mon. As the low tracks
across the South, it will spread rain northward with increasing lift
and moisture into Mon morning. The shallow cooler NE flow will be
overrun with increasing SW flow aloft with increasing isentropic
lift late tonight into Mon. Initially the moisture will be limited
to the mid to upper levels with drier air closer to the sfc. Radar
shows some light pcp falling from this mid level deck, but most of
it is not reaching the ground. Dewpoint temps were still in the 30s
this aftn most places. Expect the column to moisten up after
midnight with increasing lift into Mon. This will lead the way to
rain spreading across the area from south to north. There will be a
gradient in QPF with greatest amounts near the Georgetown and Grand
Strand coast and across SC but lowest amounts over inland NC.
Soundings showing some elevated instability along the SC coast Mon
aftn. NBM was a little more bullish in terms of any thunderstorms
and decided to keep mention out except right along the SC coast
later Mon aftn. Models still showing some differences when it comes
to track which could impact northern extent of pcp, but for now
expect greatest chc of 1 to 2 inches possible along the SC coast and
some periods of moderate to heavier rain possible. Low temps tonight
will be in the mid 40s most places and up around 50 along the coast.
Temps on Mon will remain below normal with clouds and pcp and
increasing NE winds. Expect highs between 55 and 60 most
places.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
Occluded low off the coast Mon evening will depart east-northeast
overnight, with rain coming to an end from west to east. Expect any
rain will be done by daybreak (even along the coast) with rapid
drying commencing first thing Tue. Deep dry moves in with subsidence
and north-northwest flow dropping precipitable water down around
0.30". Tue could be an interesting fire weather day with
temperatures well above normal, very dry air in place and enhanced
west-northwest flow. Forecast soundings show 20-25 kt around 5k ft.
The key will be can will mixing reach 5k ft. Forecast highs in the
mid 70s for much of the area would at least open the door for those
winds to mix to the surface. Have to keep an eye on it, but
afternoon humidity will drop to around 30% and could dip into the
upper 20s.

Surface ridge axis, stretching north from the surface high over FL
will lead to light winds Tue night. This should lead to good to
excellent radiational cooling conditions as the light winds will be
coupled with the very dry air and clear skies. Lows will be near to
slightly above normal outside of the typical cold spots which will
probably end up around freezing.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Sprawling surface high and flat mid-level flow will keep the region
dry with temperatures a little above normal Wed. Mid-level pattern
changes Thu as weak southern stream shortwave moves east along the
Gulf coast. The shortwave has more punch as it moves across the
Lower Mississippi Valley and by the time it reaches the Southeast
it`s pretty weak. The bulk of the deep moisture with the wave ends
up moving northeast, missing the local area. Not enthusiastic about
rain chances with the wave, although it will lead to increased cloud
cover and a bump in dewpoints/southerly flow. Temperatures will
remain above to well above normal.

End of the week and start of next week looking like a more robust
system will affect the eastern CONUS. Good agreement in the medium
range with respect to a strong longwave trough powering a cold front
across the Southeast. The parent cyclone moves into Canada Sat, but
the trailing cold front will move across the local area Sun. The
front is likely to be losing moisture to the advancing dry slot as
it reaches the area, but still looks like a line of convection will
accompany the front. Hard to say anything about the nature of the
event at this time range. Looks typical of a high shear, low CAPE
setup, but 7 days out a lot can change. Temperatures above normal
continue.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
High confidence in VFR continuing through this evening. Area
will remain in relatively light NE flow. As low pressure moves
up from the Gulf coast through Monday, will initially see mid to high
clouds streaming over the area but expect moisture increasing
into tonight and increasing chc of pcp spreading north, mainly
after 04z. There is moderate to high confidence in MVFR
developing in showers beginning after 08-09z all terminals
except LBT with greater confidence in IFR ceilings between 12z
and 18z on Mon. Winds will increase out of the NE after 14z
with higher gusts.


Extended Outlook...High confidence in MVFR and moderate to high
confidence in IFR through Monday evening mainly due to
ceilings, as low pressure from the south increases clouds and
rainfall. Expect improvement from west to east Monday night as
the low pushes off to the east away from the local area. High
pressure will return Tuesday with high confidence in VFR
conditions persisting through Friday.

&&

.MARINE...
Through Monday...
Marine conditions will be relatively quiet to start with NE
winds increasing only slightly into tonight remaining in the 10
to 15 kt range and seas 2 to 3 ft. Winds and seas will ramp up
into Monday with NE flow increasing up to 20 to 25 kts. Seas
will increase to 3 to 5 ft Mon morning and then up to 5 to 8 ft
by Mon aftn as low pressure lifts north from the Gulf coast
reaching the SC coast by Mon aftn. Small Craft Advisory is in
effect starting Mon morning at 9a with conditions deteriorating
further through the day.


Monday night through Friday...
Less than favorable conditions Mon night as low pressure will
be just east of the waters. The low quickly moves east-northeast
Mon night into Tue with deep northwest flow in its wake.
Conditions will gradually improve across the waters on Tue. A
Small Craft Advisory will be in effect for all zones Mon night
and currently runs through Tue afternoon, although it is
possible some or even all of the headlines could be dropped
prior to the current end time of 4PM Tue. Northwest winds drop
below 15 kt around midday Tue and will be under 10 kt Tue night
as weak return flow starts to develop. Winds will remain 10 kt
or less through Fri outside of some nearshore enhancement due to
the sea breeze each afternoon. Light winds Wed- Fri will keep
seas 3 ft or less.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...Air Quality Alert until 7 PM EDT this evening for SCZ054-058-
     059.
MARINE...Small Craft Advisory from 9 AM Monday to 4 PM EDT Tuesday for
 AMZ250-252-254-256.

&&

$$

SYNOPSIS...ILM
NEAR TERM...RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...RGZ
MARINE...III/RGZ