363
FXUS62 KCAE 300721
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
321 AM EDT Sun Jun 30 2024

.SYNOPSIS...
Hot and humid conditions continue, with afternoon and evening
showers and thunderstorms again today ahead of an approaching
frontal boundary. The front is expected to bring slightly cooler
and drier conditions to start off the work week, but building
high pressure will allow the return of temperatures near the
century mark by mid to late week.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:
- Heat Advisory in effect during the afternoon and early
  evening.
- Scattered to numerous showers and thunderstorms possible this
  afternoon/evening ahead of a cold front.

Early this morning: Expect mostly rain free conditions overnight,
with only a few light showers possible over the upstate of SC/GA
through sunrise. Skies partly to mostly cloudy. Low temperatures
will again be mild with lows expected in the mid 70s.

Today and tonight: Upper ridge that has been across the area
will begin to shift off to the west as an approaching upper
trough digs towards the Mid-Atlantic this afternoon and evening.
At the surface, a cold front will push southward towards the
forecast area through the day before moving into and eventually
into the southern cwa overnight tonight. In addition, a lee-side
trough should set up ahead of the surface front this afternoon,
helping produce additional convergence for shower and storm
development. Pwat readings at or above 2 inches will continue
today. With afternoon high temperatures expected to climb into
the middle 90s, and when combined with the moisture, heat index
values in the 105-111 are forecast. Current heat advisory will
remain in effect for this afternoon across the entire cwa. With
that being said, one fly in the ointment that could keep
conditions slightly cooler would be the development of the
showers and thunderstorms this afternoon, which would produce
additional cloud cover along with rainfall. Models do show
development beginning generally between 18z-21z, with activity
then moving across the area into the evening hours. Instability
will be rather moderate during peak heating. Best shear remains
north of the area along the Mid-Atlantic corridor. This would
help limit severe potential this afternoon, and SPC keeps the
cwa in a Marginal Risk through the period. Can not rule out some
strong gusts, along with periods of heavy rainfall, in some of
the stronger storms.

Activity should be diminishing somewhat again overnight, with
highest rainfall potential moving closer to the coastal plain
through the night as the front moves through. Overnight lows
will still be muggy as the drier air lags behind the front
somewhat. Lows tonight in the middle 70s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Key messages:
- A brief respite from the heat and humidity.

A frontal boundary stalls across or just south of the eastern
Midlands and lower CSRA during this time period. Noticeably cooler
and somewhat drier air filters into the Northern and Central
Midlands with precipitable water levels decreasing below 1.5 inches
north of I-20 and below one inch close to the North Carolina state
line. Scattered to numerous afternoon and evening thunderstorms
will be possible south of I-20 while the Northern Midlands
might see at best a slight chance of diurnal convection.
Temperatures will be below normal for early July with highs in
the mid to upper 80s and lows in the mid to upper 60s.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Key Messages:
- Heat and humidity return as high pressure aloft rebuilds.

The model ensembles depict much above normal H5 heights building
back over the Southeast U.S. during the second half of this week.
This should lead to much above normal temperatures. The
probabilistic guidance shows a better than 35 percent chance of
high temperatures in excess of 100F both Friday and Saturday.
Precipitable water levels increase to greater than 1.75 inches.
Isolated to scattered diurnal convection should develop
primarily near the remnants of a frontal boundary on Wednesday
and then primarily near the sea breeze front Independence Day
through Saturday.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
VFR Conditions Expected through the period outside of any
convection.

Partly to mostly cloudy vfr cloud cover through the period. A
cold front will be approaching the region from the north through
the day before pushing through tonight. Scattered to numerous
showers and thunderstorm should form between 18-21z, impacting
all taf locations at some point into the evening. Have generally
added vcts beginning at 19z at all locations, lasting into the
evening. Although much of the period will be vfr, do expect that
mvfr conditions could develop in convection. After 03z tonight
as the front moves in and convection pushes east, rainfall
should end at all taf sites, with vfr remaining overnight.

EXTENDED AVIATION OUTLOOK...Low chances for showers and
thunderstorms during the afternoon and evening hours continue
Monday and Tuesday, mainly over the eastern/southern Midlands
and southern CSRA. Stratus and fog possible each morning.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Heat Advisory from noon today to 7 PM EDT this evening for
     SCZ016-018-020>022-025>031-035-037-038-041-115-116-
     135>137.
GA...Heat Advisory from noon today to 7 PM EDT this evening for
     GAZ040-063>065-077.

&&

$$