-- Discussion containing changed information from previous version are highlighted. --
155
FXUS62 KILM 211032
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
632 AM EDT Fri Jun 21 2024

.SYNOPSIS...
Onshore movement of showers and thunderstorms today as a result
of a tropical wave tracking across the SW Atlantic, moving
onshore well south of the local forecast area. A warming trend
will begin Saturday, with an extended period of heat, humidity,
and diurnal convection through the middle of next week.

&&

.UPDATE...
-- Changed Discussion --
606 am edt Update...SCA extended from 6 am to 1 pm today for
the southernmost ILM waters. With 41004, 45 nm SE of CHS,
reporting 8+ ft seas and a healthy 10 sec period 5 to 6 ft
E-ESE swell. Decided to extend the SCA given some bleeding of
this healthy swell across the waters south of Murrells Inlet.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
Closed upper high centered over TN today will drop to the Gulf
Coast States tonight. This will likely weaken the subsidence
inversion across the FA, especially east of the I-95 corridor,
later today and tonight. The weak tropical low/wave will move
onshore in the vicinity of FL/GA this aftn and weakening after
moving ashore. The inverted sfc trof extending from the low
northward, will get dragged onshore the Carolinas and inland to
roughly near the I-95 corridor by the end of this period. This
will be a source of forcing for showers and isolated tstorms to
develop from especially as the subsidence aloft weakens. At this
point, will only peak POPs in the low chance, roughly between
15 and 35 percent, with the "hier" pops across the coastal
counties. After sunset, expect convection to die out except
across the adjacent Atl waters where the nocturnal shra engine
will rev up, possibly resulting in keeping a low pop along the
immediate coast as winds in the lower levels become SE-S. Max
temps today mid 80s at the coast to lower 90s across the
generally NW-N inland areas of the ILM CWA. Tonights lows milder
than previous nights, generally in the lower 70s with a few
upper 60s away from the coast.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Low-mid level ridge overhead early Saturday will be weakening
during the day as the weak Atlantic system (AL92) moves across
eastern GA and into southern SC. With PWATs on the rise, sea
breeze will likely be main focus for afternoon convection
Saturday, with inland/far northern chances dependent on strength
of subsidence inversion at 700mb. High temps in the low 90s
Saturday with low 70s Saturday night. Whatever is left of AL92
system across coastal SC Sunday will be picked up by an incoming
trough later in the day. Piedmont trough, daytime heating, and
sea breeze should lead to scattered convection Sunday afternoon
with highs in the low 90s. An upper trough approaching Sunday
night may keep pops around through overnight hours with clouds
and mixed boundary layer keeping low temps in the mid 70s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Hot and humid conditions are forecasted for Monday through
Wednesday, with potential for heat advisory conditions (heat
indices >= 105F) each day. Despite increased clouds during the
day Monday, forecasting highs in the upper 90s due to a bit of a
downslope flow and WAA. Lingering Piedmont trough, sea breeze,
and incoming front will likely lead to another day of scattered
convection.

Front stalls nearby on Tuesday before dissipating by Wednesday.
Quite a bit of dry air moves in aloft Tuesday and Wednesday,
which may be enough to limit coverage of afternoon/evening
storms. Given time of year, decent sea breeze, and without
strong subsidence, have kept pops both days around 30% for
widely scattered storms. Main focus will be high temps Tuesday
and Wednesday, as temps approach triple digits away from the
immediate coastline both days. Currently, Wednesday looks to be
the hottest day of the period. While afternoon mixing will help
a bit with humidity, it will still be quite uncomfortable both
days (and Monday) and care needs to be taken to remain cool and
hydrated.

A deeper upper trough and associated surface trough approach on
Thursday, increasing rain chances and (slightly) decreasing
temps with increasing clouds.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
VFR to start at all terminals at 12z There-after, MVFR ceilings
and possible pcpn are possible at the coastal terminals as
shower laced low level clouds move onshore. As the days
insolation increases, so will the avbl instability. The
convective lid of the past several days will not be as
prevalent, resulting in potential tstorm activity and therefore
identified it with PROB30 groups later this morning thru the
aftn, mainly at the coastal terminals. With the potential for
activity reaching FLO later in the day. After sunset, pcpn
activity should dissipate, however activity will be lurking off
the coast. May need to include VCSH for the coastal terminals
for this evening and overnight. Looking at Easterly flow that
will veer to the SE-S given the sfc pressure pattern as the
tropical wave or low moves onshore across FL/GA late today along
with it`s inverted sfc trof extending north of it pivoting
around and onshore and inland across the Eastern Carolinas later
today. Fog remains a possibility after 07Z tonight with some of
the guidance dictating IFR possibilities, especially the inland
terminals.

Extended Outlook...VFR to prevail outside of the
periodic MVFR/IFR from diurnally-induced showers/storms.
-- End Changed Discussion --

&&

.MARINE...
Through Tonight...A tightened sfc pg today will relax-some
later today thru tonight. This in response to sfc low moving
westward across the ATL Waters off the SE U.S. Coast, progged to
move onshore FL/GA coasts later today and weaken as it moves
inland. The inverted sfc trof extending north from the low to
HAT, will follow suit and also move onshore across the
Carolinas. Easterly winds will become SE after the sfc trof
passage. Winds at their relative peak this morning, will abate-
some this aftn and especially tonight, 10 kt or less. Seas also
at their peak this morning followed by a slow subsiding trend.
THE SCA will be allowed to expire at 6am this morning. The hier
SCA threshold seas will remain south of the area waters.
Overall, seas dominated by E becoming SE swell at 9 second
periods.

Friday night through Tuesday Night...South-southwest winds will
prevail across the local coastal waters Saturday through middle
of next week around Bermuda high pressure. Wind speeds peak
Sunday night through Monday night around 15-20 kts. Seas 2-3 ft
Saturday through Sunday (weakening ESE swell and S wind chop)
increase to 3-4 ft Sunday night through Monday night as
southerly fresh swell peaks. Seas lower back down to around 3
feet Tuesday. Chance of showers and thunderstorms over the
waters for most of the forecast period, particularly each night
into morning hours.

&&

.TIDES/COASTAL FLOODING...
Other - Rip Currents: A high risk of rip currents is in effect
today for Pender, New Hanover, Horry, and Georgetown County
beaches, as well as Ocean Isle Beach west in Brunswick, due to
ESE swell and full moon. Although Oak Island and the south side
of Bald Head Island should see weak rip activity today, the rip
current risk will be higher for the western half of Brunswick
and therefore a moderate risk is in effect for the county. Rip
risk will improve to moderate for east facing beaches on
Saturday as the ESE swell weakens, with a low risk forecasted
for all beaches Sunday.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...High Risk for Rip Currents through this evening for NCZ106-108.
SC...High Risk for Rip Currents through this evening for SCZ054-056.
MARINE...Small Craft Advisory until 1 PM EDT this afternoon for AMZ256.

&&

$$

SYNOPSIS...VAO
UPDATE...DCH
NEAR TERM...DCH
SHORT TERM...VAO
LONG TERM...VAO
AVIATION...DCH
MARINE...DCH/VAO
TIDES/COASTAL FLOODING...