691
FXUS62 KCAE 072356
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
756 PM EDT Sun Jul 7 2024

.SYNOPSIS...
Abundant moisture combined with an unstable air mass should
support scattered to numerous showers and thunderstorms
for each afternoon and evening through much of the next week.
Above normal temperatures are expected again, with Heat Index
values above 100 each day through next week.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Key message(s) - Slow moving storms/potential for isolated flash
flooding.

Thunderstorms have been slow to develop this afternoon and
evening, with the skies remaining largely benign until the past
hour or so. Since, a cluster of thunderstorms has pushed into
Burke and Richmond counties in GA. This has been pushing
north/northeastward at a decent pace, which is good news
considering this is the area of the FA that received the most
rainfall yesterday. However, we aren`t out of the woods yet
flash flood wise as this cluster should continue moving
northward and interact with a larger, slow moving MCS pushing
out of GSP`s area. This is the interaction that could yield our
biggest threat of the day so far, as it could slow both
complexes down a bit and lead to some training rainfall. The
atmosphere is in a similar place to yesterday with skinny SBCAPE
between 1500 and 2000 j/kg and PWs in excess of 2.25" across the
FA. With weak atmospheric flow, this favors slow moving storms
producing high rainfall totals in short periods of time. We will
need to watch the areas that were impacted yesterday the
closets, but this kind of setup tends to yield a potential for
flash flooding regardless of how dry we have been. An isolated
severe storm cannot be ruled out either. Similar to last night,
storms should weaken into stratiform rain which may take several
hours overnight and is honestly needed across the FA, so we
will likely end up being fairly warm again tonight with lows
expected in the mid 70s.


&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Key Message(s):
- Anomalously high atmospheric moisture
- Scattered to numerous diurnal thunderstorms with isolated
  flash flood threat
- High heat index readings possible again by Tuesday.

Upper trough will continue over then central U.S., with western
Atlantic ridge influencing our region. Will mention that there
is a weak upper low on the western portions of the ridge, but it
will continue to weaken and move southward through the period as
the upper ridge begins to strengthen and push further west into
Tuesday. Plenty of moisture will be over the area, with southwesterly
winds aloft bringing Gulf moisture toward us, and low-level
moisture coming inland off the Atlantic. Afternoon and evening
convection appears likely as the sea-breeze moves inland each
day, with other mesoscale boundaries from prior convection all
being potential initialization points for convection too. High
pwat values will lend to potential for periods of heavy rainfall
in any slower storms. Severe threat is minimal, but can not rule
out some gusty winds in stronger storms through the period. Temperatures
should be a bit cooler Monday due to cloud cover with highs
expected in the lower 90s, then a return to the middle 90s and
higher heat index readings on Tuesday. Can not rule out the need
for another Heat Advisory on Tuesday as latest guidance is
showing some areas climbing above 108 degrees for periods
Tuesday afternoon.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Key message(s):

- Daily diurnal showers and thunderstorms
- Heat indices exceeding 100 degrees
- Isolated flash flooding threat

Models still showing upper trough across the middle of the
country, with our region under the influence of western Atlantic
ridge. The upper trough will begin lifting on Thursday, with
increasing upper ridging building back into our area by the
weekend. Weak surface troughs, along with sea-breeze
convection moving inland each afternoon, should aid in diurnal
development of scattered to numerous convection pretty much each
afternoon through the period. Heavy rainfall can be expected
with any storms, especially with pwat readings still forecast
above 2 inches each afternoon. High temperatures climb back into
the low to middle 90s by mid-week. Heat indices are expected to
exceed 100 degrees each day. Best chance to reach heat advisory
criteria appears to be Wednesday, especially with dewpoints
forecast in the upper 70s. Slightly lower dewpoints possible by
the end of the week will bring lower heat index readings, but
still expected at or above the century mark.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR conditions through much of the TAF period with restrictions
expected this evening into early tonight and possible around
sunrise.

Convection continues to develop and will be aided in the coming
hours by and approaching boundary currently moving through the
Upstate. Showers and thunderstorms are currently around all
terminals except OGB and have a TEMPO to cover the cells as they
move through the area. Expect thunderstorms to contain brief
locally heavy rainfall and wind gusts around 25 knots. The
convection will persist through midnight and possible into the
early morning hours as boundaries collide and generate new
cells. Restrictions also possible around sunrise as moisture
will be trapped under an inversion however confidence is low as
much will depend on debris cloudiness departing the area or not.
With sunrise and heating cumulus will again begin developing and
have once again included VCSH for all terminals from 19z through
the end of the period for convection.

EXTENDED AVIATION OUTLOOK...Restrictions possible in diurnally
driven showers and thunderstorms each day as well as early
morning fog and stratus.

&&

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

&&

$$