204
FXUS62 KILM 060005
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
805 PM EDT Fri Jul 5 2024

.SYNOPSIS...
Extreme heat will persist into Saturday. Showers and
thunderstorms will return to the forecast as well on Saturday
and persist through most of next week. Temperatures will remain
above normal even after Saturday`s heat.

&&

.UPDATE...
Have ended the Heat Advisory for today, and will be raising one
for Saturday shortly. Otherwise no changes to going forecast
this evening.

&&

.NEAR TERM /THROUGH TONIGHT/...
Elongated southwest to northeast oriented mid-level ridging will
remain in place through the period, maintaining unseasonably hot and
humid conditions for Saturday, which will more than likely warrant a
Heat Advisory. A shortwave trough pivoting through the Midwest into
the Ohio Valley along with its surface low pressure system will send
a cold front into the western Carolinas tomorrow, which is expected
to stall northwest of the area. With moderate instability and little
to no convective inhibition, the front will provide a focus for
storm development across the Sandhills and western mountains while
the Piedmont trough should become more active with scattered
convection developing along it as well. Colliding outflow from
initial storms will lead to additional development and some
organization into short lines may occur along these outflow
boundaries. Very weak vertical shear will limit storm longevity and
keep the severe threat very low and isolated to wet microbursts.

With southerly winds expected through the night, overnight lows
should only fall into the mid-upper 70s. Daytime highs should reach
the mid-upper 90s again with heat indices breaching 105F around
midday and continuing into or through the afternoon. The one caveat
will be the timing and extent of thunderstorm development. In
general, it appears most storms should form inland of our western
border and spread mainly eastward along outflow boundaries late in
the afternoon, with cirrus canopies spreading northeastward. This
cirrus could temper heating enough across the inland zones to
prevent heat indices from holding at or above 105F through the
afternoon if storms develop early enough. Regardless of this
specific detail, dangerously hot and humid conditions are expected
once again.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
One last day of blistering heat as high pressure off the coast
brings a broad swath of heat and humidity into the Southeast. A
front will drop into the western Carolinas late in the day and touch
off fairly numerous thunderstorms, the coverage of which over
western zones will appear to warrant some likely POPs (dropping off
sharply as one heads east towards the coast). The storm`s late
arrival will allow advisory-worthy heat indices once again. The
front may not move much heading into Sunday but the mid level
ridging overhead weakens sufficiently that thunderstorm coverage
may be somewhat elevated above the 30-40 values common to this time
of year. More widespread cloud cover is also expected. This should
be the main factor in tempering the heat enough to preclude an
advisory.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
A bit of a complicated forecast for just about the entire period.
The front will remain stalled helping to keep rain chances elevated.
This should be good news given our rainfall deficit. Models are
having trouble handling the upper low off the coast, with the GFS
having a relatively new idea that it could retrograde this way. As
it does so slowly there is some concern that weak subsidence assoc
with it could suppress lift locally esp along the coast. Other
guidance keep it far enough to be much of a concern. Even farther
out in time the moisture from Beryl`s remnants could be a player
somewhere though that would seemingly stay  north of the area.
Temperatures will remain a bit above climatology for most of the
period but nothing like the current heat or that of the short
term.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR is expected through the TAF period. High pressure offshore
and a stalled frontal boundary/trough to the west will maintain
moderate SSW flow overnight and through Saturday. Convection
is expected to fire up in the vicinity of the trough Saturday
afternoon, and will drift eastward and may approach KFLO/KLBT
by late Saturday afternoon.

Extended Outlook...VFR is expected to prevail outside of
convection. A cold front is forecast to stall across the
Piedmont amidst plenty of moisture, which should provide a
greater coverage of convection than normal, particularly for the
inland terminals. Early morning fog and low clouds are possible
each morning, especially where precip falls the previous day.

&&

.MARINE...
Through Saturday... Breezy south to southwesterly winds in the range
of 10-20 kts will continue through Saturday around offshore high
pressure. Seas will be rather chaotic due to SErly long period
swells of 2-3 ft at 9-10 seconds running almost perpendicular to
SSWrly wind waves of 2-3 ft at 4 seconds.

Saturday through Wednesday... High pressure will remain in place
across the West Atlantic early in the period, with some drift to the
east later in the period. This will mean little deviation from the
dominance of a southerly wind direction and also wind speeds that
taper off late in the weekend. The swell component will dwindle to 8
seconds as its power continues to ease as well. For most of the long
term a 2-3 ft predominant wave height will suffice.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory until midnight EDT tonight for NCZ107.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
UPDATE...CRM
NEAR TERM...ABW
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...CRM
MARINE...ILM