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765
FXUS62 KCAE 271833
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
233 PM EDT Thu Jun 27 2024

.SYNOPSIS...
Hot and humid conditions continue into the weekend. Afternoon
and evening rain and storm chances start to increase today
through the weekend with noticeable higher moisture building
into the region.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:
- Hot and humid conditions continue today.

- Increasing moisture leading to scattered afternoon and evening
  storms beginning after 18z.

An approaching mid-level shortwave is expected to trigger some
showers and storms across the I-20 corridor and southeastward
this afternoon and evening. Hi-res guidance is in good agreement
that initiation should start between 17-18z, but overall these
hi-res members are a bit too warm with surface temps, so
initiation might be an hour or two later. The severe threat is
fairly limited given modest mixed layer CAPE and little-no cloud
layer shear despite a forcing mechanism aloft. But deep inverted
V soundings with expected strong convection may yield isolated
severe winds this afternoon and evening. Highest confidence for
heavy rainfall and severe potential are across the eastern
Midlands where heating and moisture are maximized.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
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KEY MESSAGES:
- The heat continues with a significant increase in humidity
  levels and rainfall chances.

Upper level ridging will be gradually building over the region
Friday and Saturday as southerly flow continues advecting
moisture into the area. Couple of concerns through the short
term with the first being the continued heat which will be
sightly enhanced by the increasing moisture. Heat index values
will be between 100 and 105 each day which will be just below
criteria so do not expect any headlines however the increase in
moisture will become noticeable. The other concern will be
potential for afternoon thunderstorms each day. There will be
plenty of instability and with some dry air in the mid levels
DCAPE values Friday will be in excess of 700 J/Kg and 500 J/Kg
on Saturday. Thunderstorms which become strong and well
developed vertically will have the potential to produce strong
and gusty winds. With the moisture also creating additional
clouds high temperatures each day will be in the low to mid 90s
with overnight lows in the low to mid 70s.
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&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
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KEY MESSAGES:
- Above normal temperatures persist with excessive potential on
  Sunday.
- Slightly cooler temperatures possible to start off the work
  week.

Change will be coming in the long term however Sunday will see a
potential for excessive heat and potential headlines. Moisture
on Sunday will reach a peak as a frontal boundary moves
southward toward the forecast area. This will work to trap
moisture across the area and when combined with high
temperatures in the mid to upper 90s thunderstorms will become
likely during the afternoon and evening. The heat index will be
the issue Sunday as values will push to 108 to 113 degrees which
will be well into heat advisory and possibly into the excessive
heat category (113 or higher for at least two hours or more).
Will continue to monitor as this remains several days out. With
the front crossing the area Sunday there will also be an upper
level trough crossing the region and when combined with the heat
there is potential for strong thunderstorms with the main threat
being strong and gusty winds. Behind the front slightly cooler
temperatures will move into the region with high temperatures
returning to near normal for Monday and Tuesday with
temperatures returning to the mid 90s to near 100 for Wednesday
and Thursday.

As for rainfall potential, with the front both approaching
Sunday, then stalling out across the southern areas into next
week, expect that scattered showers and thunderstorms will
remain possible through the long term. Rainfall will be highly
variable however all rainfall will be welcome as the dry
conditions are beginning to raise fire weather concerns and with
the coming holiday the potential for wildfires will be
increasing if little rainfall is received.
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&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR conditions expected through the TAF period outside of
some scattered showers and storms this afternoon and evening.

Typical summer pattern is in play today ahead of weak upper
level system, bringing some mid-level strato-cu early this
afternoon. Winds will remain out of the southwest, sustain
5-8 knots with gusts to around 15 knots throughout the late
afternoon. Some showers and storms are expected by 18z, then
linger into the evening. Confidence is high enough for a VCTS
mention at all sites from 20z through 01z; some fine tuning
of the timing will be needed at the next update. Ample
moisture overnight is expected to yield a stratus deck for
Friday morning with IFR and LIFR conditions likely.

EXTENDED AVIATION OUTLOOK...Scattered showers-storms with
restrictions each afternoon Friday through Sunday as
additional moisture moves over the region.

&&

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

&&

$$