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681
FXUS62 KILM 170745
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
345 AM EDT Fri May 17 2024

.SYNOPSIS...
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Weak high pressure will exit the coast today. Low pressure moving
east across the Carolinas this weekend will bring periods of
showers and thunderstorms. A cold front will sweep south on Sunday
bringing drier and cooler weather Monday into Tuesday. A warming
trend is expected during the middle portion of next week.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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High pressure overhead this morning will be shunted offshore as
storm system currently over the Gulf states approaches. Mid clouds
will thicken during the day today with as a rather potent shortwave
moves across from the southwest. Despite PVA and increasing
moisture, rain chances may be limited this afternoon owing to an
impressive subsidence inversion developing at 500mb midday across
the area likely due to ongoing convection in the Gulf. May see some
shallow showers develop beneath the inversion before it lowers, and
weakens, through late afternoon. Pops generally less than 30%
through sunset. Highs today approach 85F with increasing low level
WAA.

Rain chances ramp up after midnight as isentropic lift develops from
the surface up to ~310K (around 600mb) ahead of a warm front and
PWATs increase to 1.75+". Rainy and cloudy night will keep low temps
in the upper 60s. Rain coverage will begin to decrease before dawn
Saturday.
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&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
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A well-defined shortwave will move eastward across the Southeast
states Saturday and Sunday, slowing significantly as it reaches
the Carolina coast Sunday night. An upper ridge expanding
across PA/NY will likely trap the disturbance just off our
coast Monday, potentially allowing it become a closed feature as
shown on the 00z GFS.

At the surface, a diffuse area of low pressure should exist
across the central and eastern Carolinas Saturday morning,
likely responsible for sustaining scattered showers and
thunderstorms across the area. Although I certainly expect
there to be convective activity on radar, I`ve trimmed PoPs
back slightly versus previous forecasts as there are hints in
most models that a slug of mid level dry/stable air from
subsidence downstream of Gulf coast convection will traverse the
Carolinas for a portion of the day.

The surface low should push offshore by Saturday evening. The
low should remain weak, however the building upper ridge to our
north will cause rising surface pressures across the Mid
Atlantic and a tightening pressure gradient here. This will
help push a cold front south across the area Sunday. A second
round of shower and thunderstorm chances should accompany this
frontal passage, which happens to align with the upper level
trough pushing overhead too. Forecast PoPs remain rather high
(70 percent) for Sunday.

Cool air should deepen with continued northerly winds Sunday
night. Some scattered showers could continue especially along
the coast.
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&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
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The upper ridge to our north will likely continue to trap this
weekend`s shortwave and weak surface low between the Carolinas
and Bermuda through Wednesday. Shower potential should diminish
rapidly in the cool, dry northerly wind across the Carolinas.
Eventually by Thursday a significant shortwave pushing across
the Great Lakes should erode the ridge to our north, removing
the block and allowing our old (and very tired) offshore
disturbance to escape off to the east.

In terms of sensible weather, below normal temperatures are
expected Monday into Tuesday with northerly flow across the
area. Later forecasts may need to make further downward
adjustments to Monday as some guidance shows the potential for
temperatures barely eclipse 70 during the day. A warming trend
should begin in earnest by Wednesday and by Thursday summerlike
temperatures in the upper 80s are expected.
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&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Currently VFR across the area. There remains a chance for fog
before morning, mainly MVFR with patches of IFR/LIFR possible,
although saturated layer at surface is quite thin. Couple
things to keep an eye on: stretch of mid clouds moving down
from the south across NC and lingering WSW winds around 5 kts in
the area. If clouds and winds linger, chances of fog will
decrease quickly and TAF amendments will be necessary.

After daybreak, VFR to dominate rest of TAF period. Mid clouds
will be thickening during the day, around 10 kft, and lowering
this evening into tonight, though expect sub-VFR ceilings to
hold off until after 6z Saturday morning. A few storms are
possible this afternoon and evening associated with an upper
shortwave, but coverage not enough for TAF inclusion. Rain
chances increase tonight, with isolated thunder possible. Winds
remain relatively light out of the south today into tonight.

Extended Outlook...The next storm system and associated
periodic flight restrictions will affect the area late Fri night
thru the weekend and likely into Mon.

&&

.MARINE...
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Through Tonight...Light southerly winds today will increase a bit
tonight as a warm front lifts north across the waters. This will be
accompanied by increasing rain chances after midnight tonight, with
isolated thunder possible especially for northern coastal waters.
Seas linger around 2 ft today and tonight, primarily from a SE 6 sec
swell and a weak NE 8-9 sec swell moving in later today.

Saturday through Tuesday...Low pressure across interior North
Carolina will slide eastward during the day Saturday accompanied
by scattered showers and thunderstorms. Light southerly winds
should veer southwesterly Saturday night as the low goes by.
Once the low gets farther offshore and strengthens Sunday
morning, it will drag a cold front southward across the coastal
waters. Another period of rain and possible thunderstorms is
expected. Northerly winds should increase to near 20 knots by
Sunday night into Monday and there is an outside shot we`ll get
to Small Craft Advisory conditions across the Cape Fear waters.
Breezy northerly winds should continue into Tuesday as the low
stalls 300 miles southeast of Cape Fear.
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&&

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

&&

$$

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