National Weather Service Raw Text Product

233 
FXUS62 KCHS 121456
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1056 AM EDT Thu Jun 12 2025

.SYNOPSIS...
A series of upper level disturbances will affect the area
through the weekend while high pressure remains offshore. 

&&

.NEAR TERM /THROUGH TONIGHT/...
Update: Showers and embedded thunderstorms have started a bit
earlier than anticipated and both their coverage and intensity
is has been a on the higher side as well. We update the POPs to
reflect the radar trends now and the expectations for the
afternoon. Likewise, we're concerned that high temperatures may
not be as hot as expected closer to the coast for this reason.
But we only made minor changes to the diurnal temperature range.

Rest of Today: Aloft, ridging will continue to be centered from
just off the east coast of FL and extending into the forecast 
area and the Southeast. At the surface, the subtropical high 
over the Atlantic will drive the summer-like pattern as it 
extends back to the west and into the area. The morning will 
start off with isolated to scattered coastal showers from the GA
coast up through Beaufort County. These showers will be 
developing within subtle convergence boundaries that show up on 
radar and could spread up into the Charleston area as well. 
These showers will move relatively slow to the northeast within 
the weak steering flow, and could drop a few hundredths of an 
inch of rainfall. This activity should dissipate by mid morning 
and attention will then turn to afternoon convection. Convection
should start developing along the sea breeze in the early 
afternoon and gradually shift inland into the evening. Overall, 
the best coverage is expected inland of the coast especially by 
late afternoon and the evening. Model soundings aren't 
particularly impressive showing little to no shear and weak 
DCAPE values. MLCAPE looks to be in the 1,000-1,500 J/kg range. 
The overall severe threat is quite low, but we could still see a
strong to marginally isolated severe storm where boundary 
interactions can work to enhance updrafts. Storm motion will be 
very slow, on the order of 5-10 knots. This means there will be 
a threat of locally heavy rainfall and possibly a few instances 
of minor flooding. Temperatures are forecast to reach the low 
90s in most places. 

This evening and tonight: Afternoon convection should shift 
inland through the evening and we should be pretty much 
convection-free by the late evening. Overnight, we will see the 
focus for showers and thunderstorms shift to the SC coast and 
the adjacent coastal waters. There are no significant concerns 
for fog at this time. Lows are forecast to fall into the low to 
mid 70s.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
The forecast area will remain on the backside of high pressure 
at the surface and aloft late week into the weekend. Diurnally-
driven showers and thunderstorms will be possible each day, with
coverage highest in the afternoon and evening. Shortwave energy
rotating through the region at times could provide additional 
focus for convective development. Organized severe weather is 
not expected, but a couple stronger storms are possible, as is 
typical for this time of year. Highs will be seasonable in the 
upper 80s to around 90, but heat indices will likely exceed 
triple digits in many spots over the weekend. Values are held 
below Heat Advisory criteria. Lows will be in the 70-75 range, 
except a bit higher at the beaches.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Ridging will persist during the early to middle of next week, 
with a shortwave trough to pass by to the north early in the 
period. The surface will feature high pressure offshore and a 
trough of low pressure inland. Scattered showers and 
thunderstorms will be possible each day, especially during peak 
heating. Temperatures will be warming, and combined with higher 
humidity, heat indices are currently forecast to approach or 
exceed 105F, possibly even close to Heat Advisory criteria of 
108F in spots.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
15Z Update: Coastal showers are developing and are now in the VC
of the TAF sites. It is possible these showers could produce 
brief rainfall and perhaps MVFR ceilings, but the chances of 
direct impacts are low. For afternoon and evening thunderstorm 
chances, model guidance suggests the best chances will be inland
of the TAF sites. Therefore, we have not included any mention 
of thunder in the TAF's. 

Extended Aviation Forecast: Brief flight restrictions are 
possible in showers and thunderstorms each day, mainly in the 
afternoon.

&&

.MARINE...
Today and tonight: High pressure to the east in the Atlantic 
will drive southerly onshore flow across the local waters 
through the period. Wind speeds should top out around 15 knots 
this afternoon and evening along the land/sea interface with the
sea breeze. Seas are forecast to average 2-3 feet. 

Friday through Tuesday: Marine conditions are expected to stay 
below Small Craft Advisory criteria through the period. 
Southerly flow will persist with speeds 15 knots or less. Seas 
will average 2-3 feet, with some occasional 4 footers in the 
outer portions of the waters.

&&

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

&&

$$

NEAR TERM...
SHORT TERM...ETM
LONG TERM...ETM
AVIATION...ETM
MARINE...ETM