-- Discussion containing changed information from previous version are highlighted. --
494
FXUS62 KCHS 141207
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
807 AM EDT Tue May 14 2024

.SYNOPSIS...
A warm front will lift northward through the area this morning,
followed by a cold front from the west tonight. High pressure
will return to the area by Thursday, followed by another storm
system this weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: A complex of thunderstorms will continue to track east across
southern Georgia and northern Florida early this morning, while a
warm front begins to lift north across the region, before eventually
clearing the local area to the north by late morning. While
activity across northern Florida should stay south of the Altamaha
River initially, the northern extent could impact far southern
zones along the southeast Georgia coast a few hours after daybreak
and bring the potential for a few stronger and perhaps severe
thunderstorms as the warm front pivots north across the area.
Along the warm front, thunderstorms will likely develop and
progress north through late morning, with highest chances of
severe weather occurrence closer to the southeast Georgia and
southeast South Carolina coast where the axis of greatest instability
crosses over land from the Atlantic. With the morning activity,
the severe threat will likely be tied to the environment along
and near the front itself, where modest MLCAPE and veering wind
profiles reside. Damaging winds and a low-end tornado threat are
the primary concerns during morning hours. However, enhanced
convergence associated with the front could also lead to a brief
window of localized heavy downpours, resulting in 0.5 to 1.5
inches of rainfall along the southeast South Carolina coast.

As the warm front shifts north of the Santee River and the
thunderstorm complex to the south pushes across coastal waters,
there will likely be a lull of precip activity early to mid
afternoon, as it will take some time for the airmass to recover
locally despite becoming warm-sectored for much of the day. Latest
guidance does indicate a fairly large shift in lowering overall
precip coverage during this time frame, thus chances of precip have
been reduced for much of the afternoon. However, there will still be
a risk for isolated severe thunderstorms heading into mid-late
afternoon hours, that could very well persist into early evening
hours as another round of h5 shortwave energy rounds the southeast
periphery of the mid-upper lvl trough placed to our northwest.
Enhanced unidirectional wind fields along with some mid-lvl drying
leading to higher DCAPE suggests a few thunderstorms could produce
damaging wind gusts and/or perhaps some small hail.

Tonight: Although latest guidance does suggest a fairly large trend
downward in precip coverage this evening, the atmosphere should
remain somewhat favorable for a low-end risk of strong and/or
isolated severe thunderstorms for a few hours after sunset well in
advance of a cold front approaching from the west late. Instability
will become limited by late evening, especially across southeast
South Carolina, but could linger across southeast Georgia after
midnight. Here additional showers and thunderstorms that develop
west of the region could eventually push into far southern zones,
before shifting offshore. Although severe weather is not expected
based on the timing of what could be another thunderstorm complex
nearing the area, the threat will remain non-zero until the cold
front pushes through the area and offshore late. Overnight temps
will remain mild until fropa occurs with lows generally expected to
range in the mid 60s inland to upper 60s/around 70 near the
coast.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
A mid-level low pressure and it`s associated surface low pressure
will be positioned over the Mid-Atlantic states to start Wednesday
This feature will slip off the East Coast Wednesday night into
Thursday. A secondary, reinforcing cold front is forecast to push
through the region early in the morning on Thursday as the upper
level feature moves offshore. In the presence of the upper level
low, there will likely be enough forcing to trigger an isolated to
scattered shower or thunderstorm through the day on Wednesday,
tapering off in the evening to overnight hours. Dry conditions are
then expected Thursday as high pressure briefly builds in at the
surface. A shortwave trough aloft approaching from the west on
Friday will then trigger isolated to scattered showers and
thunderstorms, with PWATs increasing to 1.5+ inches Friday afternoon.
High temperatures through the short term period will generally
be in the mid to upper 80s with mild overnight lows in the mid
to upper 60s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Friday night into Saturday a mid-level trough will push off of the
Mid-Atlantic coast, with a surface cold front sweeping through the
region. Behind the departing trough northwesterly flow aloft will
prevail before another shortwave trough ripples across the southeastern
states on Monday. Between the upper level features and the cold
front at the surface the extended forecast will feature PoPs
almost every day as the pattern remains rather unsettled. Temperatures
are expected to be above normal.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
A complex of showers/thunderstorms will shift into the area
early this morning, likely impacting the SAV terminal by 13Z and
persisting to around 15Z initially. MVFR conditions will be
ongoing at SAV at well, but once thunderstorms reach the
terminal tempo IFR conditions are likely. Further north, MVFR
conditions should begin to impact CHS/JZI within the next 1-2
hours, then persist through 15Z as showers and potentially
thunderstorms impact the terminals. Conditions will improve to
VFR at all terminals by early afternoon, once a warm front
quickly advances north of the region. However, tempo MVFR
conditions can not be ruled out at the terminals this afternoon
should additional showers and/or thunderstorms develop late day.
Expect prevailing VFR conditions at all terminals overnight.

Extended Aviation Outlook: Prevailing VFR through the end of the
week, when showers and thunderstorms could bring restrictions to
terminals into the weekend.
-- End Changed Discussion --

&&

.MARINE...
Today and Tonight: South-southeast winds and seas will remain
elevated across local waters this morning as a warm front lifts
north and eventually leaves the area by early afternoon. Small Craft
Advisories will be in place across offshore Georgia waters until 2
PM and across nearshore waters along the Charleston County coast for
much of the day, mainly due to seas around 6 ft. Otherwise, expected
south-southeast winds upwards to 15-20 kt across local waters
turning southwest this afternoon and remaining at or below 15 kt
while the pressure gradient weakens. Heading into early evening,
winds/seas are expected to remain below advisory levels across all
waters, but a slight uptick in south-southwest winds (15-20 kt) is
anticipated with the approach of a cold front late. Seas should
range between 2-4 ft nearshore to 3-5 ft across offshore Georgia
waters overnight.

Wednesday through Sunday: All Small Craft Advisory conditions should
be over to start Wednesday, with seas averaging 3 to 5 ft and SW
winds 15 knots with gusts to 20 knots. A cold front is expected to
push through the region on Wednesday, shifting the SW winds to the
NW by Thursday, remaining around 15 knots. The remainder of the
period is expected to remain below Small Craft Advisory criteria,
with seas averaging 2 to 4 ft and winds generally 10 to 15
knots.

Rip Currents: Strong onshore winds along with 2-3 ft swell every
6-7 seconds favors a Moderate Risk of rip currents along all
beaches today.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for AMZ350.
     Small Craft Advisory until 2 PM EDT this afternoon for AMZ374.

&&

$$

NEAR TERM...DPB
SHORT TERM...CPM
LONG TERM...CPM
AVIATION...CPM/DPB
MARINE...CPM/DPB