Area Forecast Discussion Issued by NWS Wilmington, NC
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000
FXUS62 KILM 131912
AFDILM
Area Forecast Discussion
National Weather Service Wilmington NC
312 PM EDT Wed Mar 13 2024
.SYNOPSIS...
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Temperatures will warm well above normal late this week as high
pressure shifts offshore. Showers and thunderstorm chances will
return Friday afternoon as a cold front approaches. Unsettled
weather may continue through Sunday night ahead of a stronger
cold front. Dry and much colder air will build in for Monday
and Tuesday next week.-- End Changed Discussion --
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.NEAR TERM /THROUGH THURSDAY/...
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Surface high pressure will remain parked off the Southeast US coast
while a mid-level ridge axis draws nearer. This will bring a notable
increase in 1000-500mb thicknesses from around 556dam this afternoon
to around 562dam tomorrow afternoon. The result will be very warm
temperatures for this time of year with low 80s expected away from
the coast. Record highs for our climate sites in the upper 80s are
more than likely safe, but still, it will feel like the middle of
Spring outside. However, with low-level flow backing to southerly,
the sea breeze should have an easier time advancing inland than
today, limiting coastal areas to the 70s. Very dry air mixing down
today will remain a concern tomorrow as the source of dry air just
above the boundary layer remains in place. Thus, relative humidity
should bottom out in the 20s, with some of the driest spots dipping
below 20%. Given the past few days of sunny skies and very dry
afternoons, fine fuels will continue to dry out and will begin
to pose a risk of quick fire spread if ignition were to occur.
Tonight`s lows will end up near to slightly above normal as
dewpoints rebound into the 40s this evening, leading to mid-upper
40s for lows. With light or calm winds expected, some normally
cooler spots may dip to near 40F.-- End Changed Discussion --
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.SHORT TERM /THURSDAY NIGHT THROUGH SUNDAY NIGHT/...
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A pair of upper level disturbances will cross the Carolinas
this weekend, providing two potential shots of showers and
thunderstorms. Neither look particularly strong and forecast
rain chances are currently 50 percent or less for each system.
Surface high pressure will drift away from the Carolina coast
Thursday night into Friday, allowing unseasonably warm air to
bleed northeastward across the Carolinas. Thursday looks warm
but Friday looks even warmer as 850 mb temps of +13 to +14C
support highs in the lower 80s for all but the immediate coast.
Moisture should increase from the west late Friday afternoon as
the first upper disturbance approaches and this should support
increasing coverage of showers. Forecast soundings show enough
depth of conditional instability to support thunder chances in
the forecast, but rapid storm motion should keep precipitation
totals rather low.
A synoptic cold front pushed southward by low pressure off
coastal New England should stall in the Cape Fear region
Saturday morning. Despite the increase in low level convergence
with the stalled boundary, drier and warmer mid levels should
limit instability to a shallow layer below 750 mb and forecast
PoPs Saturday are being capped at 20 percent.
The second upper disturbance will reach the area late Sunday,
accompanied by a similar increase in mid level moisture with
attendant increases in forecast shower and thunderstorm
potential. Unlike yesterday, the Canadian and ECMWF have both
shifted their QPF max southward with this system, leaving the
GFS as the only model suggesting high precip chances locally.
I`m limiting PoPs to around 40 percent Sunday night. Another
surface low moving across southern Canada will drag a cold front
toward the Carolina coast late Sunday night.-- End Changed Discussion --
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.LONG TERM /MONDAY THROUGH WEDNESDAY/...
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A Canadian cold front will push farther offshore Monday,
allowing colder and much drier Canadian air to spread across the
Carolinas and offshore. 850 mb temps look to fall below 0C
Monday night, bottoming around near -5C during the day Tuesday.
A breezy boundary layer Monday night should keep temps from
crashing (forecast lows are currently upper 30s inland) but
Tuesday night could be touchier as the center of the Canadian
high approaches and winds drop off. After highs only in the
upper 50s Tuesday, Tuesday night`s lows could dip low enough
for frost to become a concern. There`s plenty of time to watch
trends on this.
Otherwise dry weather is expected through the period.-- End Changed Discussion --
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.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR expected to persist through the TAF period. Deep mixing
beneath sunny skies and subsidence aloft will permit occasional
gustiness with speeds up to around 15 kts or so. A sharp sea
breeze will remain pinned near the SC coast with slow northward
progress into the Cape Fear region bringing a wind shift to
southerly behind it. Winds will quickly subside near and after
sunset with light and variable flow expected through the night.
With high pressure well offshore, a weak south to south-
southeasterly flow should become dominant by midday tomorrow.
Extended Outlook...Dry high pressure will bring VFR conditions
through Friday morning. A couple cold fronts will affect the
area over the weekend, bringing the next chance for a couple periods
of flight restrictions, mainly Friday night through Saturday
night and again from Sunday night into Monday.
&&
.MARINE...
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Through Thursday... Surface high pressure will remain off the coast
of the Southeast US through the period, bringing benign marine
conditions. Southerly wind waves of 1-2 ft with a period of 4 sec
this evening and tonight will settle down to around 1 ft for
Thursday. A healthy sea breeze can be expected tomorrow as southerly
winds help to push it inland, with gusty winds behind it.
Thursday night through Monday...High pressure off the Carolina
coast will drift farther offshore Friday as a cold front
advances eastward across the Southeast states. Initially light
southwest winds Thursday night will begin to increase on Friday,
peaking near 20 knots late Friday afternoon and evening.
Scattered showers and a few thunderstorms are possible Friday
night. It still appears we will get through this event without a
Small Craft Advisory becoming necessary. Objective model blends
only show a 20-40 percent chance of gusts reaching 25 knots
Friday evening. Winds should diminish and become variable in
direction Saturday morning as the front stalls across Cape Fear.
Wind directions will turn back to the southwest again Saturday
night into Sunday as another frontal wave reaches the Carolinas
by Sunday night. As this system clears offshore Monday morning
increasing northwest winds are expected as sprawling Canadian
high pressure begins to build southeastward.-- End Changed Discussion --
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.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...None.
MARINE...None.
&&
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SYNOPSIS...TRA
NEAR TERM...ABW
SHORT TERM...TRA
LONG TERM...TRA
AVIATION...ABW
MARINE...TRA/ABW