-- Discussion containing changed information from previous version are highlighted. --
984
FXUS62 KCHS 101137
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
737 AM EDT Mon Jun 10 2024

.SYNOPSIS...
A cold front will gradually sag southward across the forecast
area today. The front will become stationary near/along the
coast through the rest of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
At 740 AM, KCLX detected isolated thunderstorms across portions
of the CHS Tri-county, moving east between 35-40 mph. These
storms should move north and east of the forecast area by 830
AM. Storms should provide rain-cooled temperatures in the low to
mid 70s across the Tri-County. The updated forecast will feature
adjustments to hourly PoP, Wx and temps to align with recent
observations.

Temperatures should begin the day in the mid 70s, with a few areas
in the upper 70s along the coast. Given steady west winds and strong
June insolation, temperatures should rapidly warm across the
forecast area this morning. Areas across SE GA could exceed 90
degrees by noon, peaking in the low to mid 90s by early afternoon. A
cold front is expected to remain nearly stationary across SE GA this
afternoon. Near term guidance indicates that a amplifying H5 H5
trough will reach the western Carolinas and Georgia this afternoon.
As a result, a weak frontal wave is forecast to develop across SE
GA, likely resulting in winds along the GA and SC coast to shift
from east. Sfc dewpoints along the coast are expected to rise into
the low to mid 70s this afternoon. Heat index values across extreme
SE GA may peak between 100-104.

The hot and humid BL will combine with the falling heights aloft to
produce a moderately unstable environment this afternoon and
evening, especially along the coast. In fact, HRRR forecast
soundings indicates that coastal area may see CAPE peak between 2500-
3000 J/kg, with little to no inhibition. North of the sfc low, SRH
values may range between 100-150 m2/s2 and effective bulk shear
around 50 kts. In addition, DCAPE may range from 1300-900 J/kg this
afternoon. The combination of deep instability, shear, and the
passage of synoptic scale forcing should result in numerous to
widespread thunderstorms this afternoon and evening. Several
supercell thunderstorms may develop across the CWA this afternoon
and evening, capable of producing large hail and damaging wind
gusts. SPC has highlighted most of the forecast area with either a
Marginal or Slight Risk today. 0Z HREF parameters suggests that area
along and east of I-95 should see the greatest potential for severe
thunderstorms. The severe risk will be highlighted in the HWO for
both land and marine zones.

In addition, PW values around 1.8 inches will be common across the
forecast area this afternoon and evening. Organized thunderstorms,
especially supercells, may develop heavy downpours, resulting in
swaths of 1-1.5 inches of rainfall. Steering flow and a field of
moderate DCAPE may result in storm motions up to 40 mph.

Tonight, convection will be ongoing across the region this evening,
then pushing off the coast late. PoPs will decrease from west to
east, ending by the pre-dawn hours. Cooler temperatures expected
across the region tonight. Low temperatures may range from the mid
to upper 60s inland to around 70 along the coast.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
A positively-tilted upper trough over the eastern CONUS Tuesday will
lift out of the Southeast overnight into Wednesday replaced by
northwest flow aloft. An area of broad high pressure will be
centered to our northwest and will gradually build into our region
through the week. A surface stationary front will meander just off
or near our coast through the period. This will result in a fairly
decent moisture gradient across the area with relatively dry high
pressure inland and moisture rich air streaming northeast over the
Florida Peninsula and into the Atlantic. Despite the virtually
stagnant synoptic pattern, a tricky forecast is in play this week in
terms of convection. Showers and thunderstorms should be limited
over the coastal waters, but with PWATs near 1.5" over land, there
should be enough moisture and instability to generate at least
isolated convection along the coast (in proximity to the stationary
front). The general thinking is that areas far inland will likely
remain rain-free through most of the week. However, an inland
(offshore) shift in the boundary could result in greater (lesser)
coverage over land with southeast Georgia being the prime location.
Any convection that does develop should diminish in the evening.

Temperatures will remain nearly constant each day with highs in the
upper 80s to low 90s. Lows will range from the upper 60s far inland
to the lower 70s near the coast and mid 70s along the beaches both
Tuesday and Wednesday night.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
The general pattern remains largely unchanged for the remainder of
the week. Ridging aloft should slide in from the southwest, with
surface high pressure across the northeast CONUS and an area of low
pressure developing in the southwestern Gulf of Mexico. Scattered
showers and thunderstorms associated with a progressive sea breeze
are possible in the afternoon/evening each day. Temperatures should
range near or slightly above normal through the weekend.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
Tonight: Prior to the 12Z TAFs, KCLX detected isolated
thunderstorm tracking over or near KCHS and KJZI. Both TAFs will
feature a mention of thunderstorms through 13Z. Then, all
terminals should remain VFR through the rest of the morning.

This afternoon, a sfc cold front is expected to become nearly
stationary across southern GA. A mid-level disturbance will
swing over the region this afternoon, resulting in a weak area
of low pressure to develop across SE GA. The low should aid in
pooling instability over the Coastal Plain and provide veering
winds. The environment north of the low will be suitable for
numerous to widespread thunderstorm development this afternoon
and evening. Each TAF will feature a TEMPO from 20-24Z for gusty
winds and IFR vis during thunderstorms. TSRAs will be featured
as the predominate weather from 0-4Z this evening at each TAF.
There is some potential for severe wind gusts or hail with the
afternoon and evening thunderstorms. By late this evening,
convection should push east across the adjacent waters. TAFs are
forecast to remain VFR with light and variable winds through the
rest of the night.

Extended Aviation Outlook: Mostly VFR conditions expected; however,
isolated convection could bring brief flight restrictions mainly in
the afternoon period this week.
-- End Changed Discussion --

&&

.MARINE...
Today, a cold front will remain nearly stationary across the marine
zones this morning. A weak area of low pressure is expected to
develop across SE GA this afternoon, tracking ENE across the waters
tonight. Wind directions will vary through today and tonight, with
speeds generally between 10 to 15 kts. Seas should remain between 2-
3 ft through today and tonight. The primary concern will be the
development of strong to severe thunderstorms across SE GA/SC this
afternoon, pushing off the coast late this afternoon and evening.
Some of these thunderstorms will be capable of producing winds in
excess of 35 kts and large hail. An isolated waterspout will be
possible, especially north of Ossabaw Island.

Tuesday through Saturday: Broad high pressure inland with low
pressure to the south will result in winds shifting predominately
out of the east-southeast through the period. Wind speeds, fairly
light on Tuesday, will average around 10 kt Wednesday into
Saturday. Seas will average 2-3 feet.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$

NEAR TERM...NED
SHORT TERM...BRM
LONG TERM...BRM
AVIATION...BRM/NED
MARINE...BRM/NED