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878
FXUS62 KILM 260813
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
413 AM EDT Wed Jun 26 2024

.SYNOPSIS...
Hot and humid conditions will continue through the weekend. Two
cold fronts will move into the region on Thursday and Monday
bringing increased chances of thunderstorms. Hot temperatures
will cool back to normal early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
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Heat will main concern again today. Compared to previous days and
the remainder of the week, partial low level thicknesses peak today
across the I-95 corridor and points eastward toward the coast. A
Heat Advisory has been issued for much of the area west of a line
from Elizabethtown to North Myrtle Beach. High temperatures in these
areas will approach 100 with some areas possibly topping out between
100-102 degrees. Near the SC coast, temperatures will be slightly
cooler with low to mid 90s expected, but the increased humidity here
necessitates the heat advisory in these areas. Majority of the area
in the Heat Advisory will see heat indices 105-109 for most of the
day.

Onshore flow from high pressure to our east will keep temperatures
in extreme southeastern NC in the lower 90s, but humidity will be
increased. Expect heat indices in the low 100s just inland from the
coast.

Isolated storms are possible again today, very similar to storms
around the area yesterday. The best chance of seeing a storm or two
will be portions of northeastern SC east of I-95 and west of the
immediate coast.

Warm and humid overnight in persistent onshore flow. Lows likely to
remain in the mid 70s overnight.
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&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
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Ahead of a surface cold front and a sharpening mid-level
shortwave trough, hot and humid conditions will prevail across
the region with heat indices likely to reach Heat Advisory
criteria (heat index of 105F to 109F for at least 2 hours)
amidst highs in the mid-upper 90s and dewpoints in the low-mid
70s (with some upper 70s possible nearer to the coast). This
will generate moderate to strong instability during the
afternoon as the cold front nears and forcing for ascent
attendant to the shortwave arrives from the northwest. The
result should be at least scattered showers and thunderstorms
developing and tracking southeastward during the afternoon and
evening, with a threat for isolated severe wind gusts and large
hail. With weak to modest 0-6km bulk shear depicted in forecast
guidance, initial storms that develop should feature a hail
threat before their outflow propagates outward and drives new
storm development, with damaging winds becoming the predominant
threat as cold pools merge. Showers and storms should gradually
shift south and east as the front settles through the area,
although the front will be stalling out as the shortwave driving
it shifts away and the flow aloft becomes parallel to the
boundary. Low temperatures will depend on the extent of
dry air brought by thunderstorm cold pools as little dry
advection occurs behind the front. Lows in the low-mid 70s are
forecast.

On Friday, mid-level heights rise as ridging takes over aloft
while surface high pressure quickly shifts across New England
and offshore, turning our winds to southeasterly. Forecast
soundings show a moist atmosphere below 500mb and weak to
virtually nonexistent capping, which should permit a greater-
than-normal coverage of diurnal showers and thunderstorms along
the typical forcing mechanisms - the Piedmont trough inland and
the sea breeze along the coast. Highs in the low-mid 90s are
expected with heat indices possibly reaching Heat Advisory
criteria once again.
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&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
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Ridging aloft will dominate through the weekend with Heat
Advisory-level heat indices possible each day before a rather
potent shortwave pivots through on Monday, sending a cold front
into the region which should bring at least a brief respite from
the heat and humidity. Isolated diurnal pop-up showers and
storms are possible on Saturday and Sunday with dry mid-level
air keeping coverage at a more typical level. However, a cold
front sliding down from the northwest in tandem with forcing for
ascent provided by the aforementioned shortwave looks to bring
an elevated chance for showers and thunderstorms from Sunday
night into Monday as the front stalls just south or over the CWA.
This may bring a risk for flash flooding if heavy thunderstorms
end up training over the same areas, especially with pwats at
or above 2". Depending on how far south this front tracks,
slightly cooler and drier conditions may be in order by Tuesday
before ridging builds back in.
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&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Stratus developing inland this morning in the wake of
convective outflow. Have decreased the coverage of morning fog
due to light winds, debris clouds, and the recent development of
stratus. Still expect inland areas to have some VIS
restrictions, with a better chance of low stratus (primarily IFR
near sunrise). Along the coast, MVFR is likely in onshore flow
and convective debris clouds.

VFR for the rest of the day after 13Z. Isolated showers and
storms very similar to yesterday, primarily in coastal SC.

Extended Outlook...VFR should prevail outside of periodic
MVFR/IFR during diurnal showers/thunderstorms plus spotty
morning low clouds/fog. Thursday afternoon and evening has the
highest potential for convection affecting local airports.

&&

.MARINE...
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Through Tonight... Bermuda high will bring onshore winds today.
Winds will increase this afternoon as an inland Piedmont trough
develops in response to temperatures in the triple digits across a
large portion of central NC/SC. South winds around 15 knots could
gust to 20-25 knots during the late afternoon and evening. Winds
shift slightly tonight ahead of the next trough and associated cold
front. SW winds remain elevated overnight.

Thursday through Sunday... Southerly flow will dominate through
the period except for a stretch of southeast winds behind a
cold front for Friday into early Saturday. Wind speeds of 10-15
kts on Thursday will relax to around 10 kts or so for the
remainder of the period until the next front approaches on
Sunday. Seas in the 2-3 ft range will driven by southerly 2-3
ft wind waves through Thursday before a 1-2 ft ESE swell at 8-9
sec takes over for Friday through the weekend.
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&&

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

&&

$$

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