286
FXUS62 KCAE 050005
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
805 PM EDT Thu Jul 4 2024

.SYNOPSIS...
Atmospheric moisture increases into the weekend with isolated
to scattered showers and thunderstorms each day beginning
Friday. Above normal temperatures are expected Friday and
Saturday with Heat Index values up to 110 possible. Atmospheric
moisture remains high through the long term supporting a chance
of showers and thunderstorms each day.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Key Message(s):
- Muggy conditions overnight with lows well above average.

Cumulus clouds dissipating as the sun sets this evening. Some
high cirrus clouds across the north coming over the top of the
upper level ridge centered southwest of the area. As the surface
ridge has moved offshore and a cold front approaches the
forecast area, a strengthening southwesterly low level jet
develops overnight which will increase low level moisture as
well as keep low temperatures warm overnight. Expect muggy
conditions overnight as a result with low temperatures near the
daily record max in the mid to upper 70s.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Key Message(s):
- A Heat Advisory is in effect from 11am to 8pm Friday
- Low threat of severe thunderstorms and flash flooding Saturday

Heat: Moisture increases on Friday pushing Heat Index values up
to 110. MOS dewpoints in the afternoon are in the low to mid
70s which are several degrees higher than the previous day. With
warming 850mb temps and only widely scattered convection
expected, we will likely see highs in the upper 90s to around
100 degrees. Despite PWAT values around 1.7 to 1.9 inches, upper
ridging over the FA should be sufficient to suppress widespread
convection. Dewpoints continue to increase on Saturday with
PWAT values over 2 inches. However increased convergence ahead
of a front and some shortwave energy moving into the region will
promote higher convective coverage than Friday. So confidence
in a Heat Advisory for Saturday is limited. Convection and cloud
cover should keep us cooler than Friday.

Thunderstorms: An upper level trough will move into the Great
Lakes region then into New England this weekend. The associated
front will remain west of the area however increased convergence
ahead of the front and rising atmospheric moisture will lead to
scattered or numerous showers and thunderstorms for Saturday
afternoon. Shortwave energy rounding the base of the trough may
also support convection in the afternoon and evening. PWAT
values as high as 2.5 inches indicates potential for flash
flooding however the threat will be hampered by 10 to 20 kt
cloud layer winds. The flash flooding potential may be limited
to training storms or urban areas. A tall, skinny CAPE profile
suggests limited updraft strength but precip loading may promote
isolated downbursts in some of the deeper storms.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Key Message(s):
- Daily afternoon thunderstorms expected for much of the period

A fairly persistent synoptic pattern dominates the long term
period. Global ensembles favor positive 500mb height anomalies
over the Southeast with mean PWAT values very steady around 2
inches through the end of the long term. With near or above
normal atmospheric moisture and weak ridging in place, we would
expect a common summertime pattern of diurnal showers and
thunderstorms with temperatures near or a little above normal.
As is typical for the season, there could be an isolated severe
threat each day.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR conditions expected through the TAF period.

Cumulus have generally dissipated as heating quickly wanes. with
scattered cirrus expected to cross the region overnight. Concern
for the period remain potential for early morning fog and
stratus. This is complicated by particulates from area fireworks
displays. Although moisture has been gradually increasing there
will be a 20 knot LLJ over the area so the potential is lowered
and have remained without mention of early morning and sunrise
restrictions. Will continue to monitor and for impacts of
fireworks displays. With sunrise and onset of mixing cumulus
will once again begin developing with winds turning more
southerly through the day with speeds remaining 10 knots or
less. Convection will be possible near the end of the TAF period
however confidence in timing and coverage remain too low to
include.

EXTENDED AVIATION OUTLOOK...Restrictions possible in diurnally
driven convection each day. The greatest convective coverage
expected Sat/Sun afternoon.

&&

.FIRE WEATHER...
Key messages(s):
-Hot temperatures will continue through the weekend
-Rainfall probabilities increasing Friday through early next
 week

Hot temperatures will continue through the weekend with
increasing moisture and chances of showers and thunderstorms
Friday into early next week. Although there was some rain late
in the weekend and into early this week the hot and dry
conditions over the past few days have generally minimize any
improvement from the rain. Moisture has begun increasing over
the area and scattered afternoon and evening thunderstorms
possible Friday mainly along and north of I-20. Increasing
coverage of afternoon and evening showers and thunderstorms are
expected to spread across the Midlands and CSRA Saturday through
much of next week. Temperatures will also be a concern with
afternoon highs in the upper 90s to around 100 which will push
heat index values to 110 Friday and between 105 and 110
Saturday.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Heat Advisory from 11 AM to 8 PM EDT Friday for SCZ016-018-
     020>022-025>031-035-037-038-041-115-116-135>137.
GA...Heat Advisory from 11 AM to 8 PM EDT Friday for GAZ040-063>065-
     077.

&&

$$