118
FXUS62 KCAE 271703
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
103 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/...
KEY MESSAGES:
- The heat continues, but with a significant increase in
  humidity levels and rainfall chances.

The upper level trough will move through the region Friday,
with the upper ridge then moving back in for Saturday. Moisture
will be on the increase through the period, with pwat climbing
back above two inches both days. With the moisture increase,
afternoon high temperatures should only reach into the middle
90s, but that same moisture increase will bring heat indices
above 100 degrees each day. Saturday could see heat index
readings close to or above advisory criteria once again.

&&

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

A surface front will be approaching the region on Sunday, but it
is not expected to move through the forecast area until Sunday
night or Monday morning. This front will then stall out across
the southern Midlands and CSRA. Ahead of the front on Sunday,
temperatures will reach into the middle 90s, which sounds good
compared the the heat we have recently been having. However,
there will be a noticeable increase in moisture ahead of the
approaching front, and this is expected to bring heat index
readings up to between 105-113 degrees in many areas. This would
be some of the highest readings so far this season across the
area. If these values continue to be indicated, an advisory
would at least be needed for Sunday. Slightly cooler
temperatures are then expected Monday through Tuesday as the
upper ridge breaks down some, allowing an upper trough to move
through and heights to fall somewhat. Wednesday will see the
return of a building upper ridge, bringing hotter temperatures
back to the area. Highs around 90 possible Monday and Tuesday
before warming back into the middle 90s for Wednesday.

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 much of the longer term.

&&

.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.

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...