-- Discussion containing changed information from previous version are highlighted. --
107
FXUS62 KCAE 250542
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
142 AM EDT Tue Jun 25 2024

.SYNOPSIS...
Hot temperatures are expected to continue into midweek. Isolated to
scattered showers and thunderstorms should occur each afternoon and
evening, with better coverage likely Thursday. Increasing heat
impacts Friday through the weekend.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
KEY MESSAGES:
-A few thunderstorms possible east this evening.

A couple of surface boundaries are being noted on radar and
through surface observations. There`s a moisture boundary over
the eastern portions of the forecast area. East of that
boundary, dew points are around 70 while dew points west of the
boundary are in the upper 50s to mid 60s. Not expecting this
boundary to move all that much any more this evening into
tonight. A second boundary is roughly along I-20 east of the
Columbia area and sliding south. This boundary has sparked some
showers and thunderstorms just east of our forecast area. As
this boundary continues to slide south and likely collide with
the moisture boundary, a few showers or thunderstorms could
develop over the next 3 to 4 hours. Otherwise, expect overnight
lows in the lower to mid 70s.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
KEY MESSAGES:
-Hot conditions to continue with max heat indices of 100-105.
-Widely scattered to scattered afternoon/early evening
thunderstorms, greatest coverage in the southeast Midlands.


The region will be located along the eastern periphery of an upper
level ridge on Tuesday. At the surface, a weak front will generally
stall just southeast of the area. Higher levels of moisture will
persist in closer to proximity to the stalled front (southeastern
Midlands) with dewpoints in the upper 60s/lower 70s and precipitable
water values around 1.75 inches. However, farther inland, the
airmass will be significantly drier with dewpoints bottoming out in
the lower to mid 60s and precipitable water values of 1.00-1.25". As
a result of the increased moisture and low level convergence, CAMs
show isolated to scattered showers and thunderstorms focusing across
the eastern Midlands and perhaps lower CSRA during the afternoon and
early evening hours on Tuesday. Soundings show enough instability
and dry air in place aloft to support a damaging wind threat with
any storms that do form. Temperatures will be above normal once
again, but with more of a northeasterly/easterly low level flow,
expect conditions to be perhaps a couple of degrees cooler than
Monday with highs in the mid-upper 90s and heat index values of 100-
105.

The front will lift north of the area on Wednesday, setting up more
of a southerly low level flow. Diurnally driven isolated to
scattered showers and thunderstorms are possible across most areas.
Slightly rising heights and the southerly flow should result in
warmer high temperatures, with highs in the upper 90s in most areas.
Fortunately, dewpoints should mix out enough in the afternoon to
keep heat index values to 100-105 degrees.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
KEY MESSAGES:
-Highest chances of showers and thunderstorms Thursday, some
possibly severe.
-Increasing heat impacts expected Friday through the weekend.

Models show an upper trough swinging through the area on Thursday,
and an associated cold front at the surface. This should provide
enough forcing to result in at least scattered showers and
thunderstorms in the afternoon/evening, and perhaps be the day with
the greatest rain chances in the long term. Overall shear is not
that strong, but soundings show weaker capping, moderate instability
and more a pronounced inverted V, suggesting the potential for a few
strong/severe thunderstorms with primarily a wind threat.

Ensembles are in good agreement showing a strengthening upper ridge
aloft Friday through the weekend. Diurnally driven scattered showers
and thunderstorms are possible each day, but knocked down the NBM
POPs a bit as the subsidence aloft looks to be fairly strong.
Temperatures will rise through the weekend beneath the building
ridge, and heat impacts will once again become an issue.

Ensembles show the ridge breaking down on Monday as an upper trough
passes to the north, potentially resulting in greater rain chances
and cooler temperatures.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
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VFR conditions expected through the TAF period.

Drier air continues to move in over the terminals early this
morning with scattered clouds around 10kft. Winds remain around
5 kts out of the NE overnight at the terminals with winds
shifting more easterly after sunrise between 5 to 10 kts.
Cumulus field develops around 5kft late morning with highest
chance for any showers or thunderstorms east of the terminals.
Winds generally becoming light and variable after sunset
tonight.

EXTENDED AVIATION OUTLOOK...Increasing chances for afternoon
scattered showers and thunderstorms and associated restrictions
through Saturday.
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&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.

&&

$$