781
FXUS62 KCAE 210722
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
322 AM EDT Sun Jul 21 2024

.SYNOPSIS...
A frontal boundary will be stationary across the region for the
next several days with increased shower and thunderstorm
activity mainly in the afternoon and evening hours. Some
locally heavy rainfall is possible which could result in areas
of flash flooding and rising river levels. Temperatures will be
near to slightly below through the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Message(s):

- Areas of low clouds this morning give way to partly to mostly
  cloudy skies
- Scattered showers and thunderstorms along with the potential
  for locally heavy rainfall continue

Radar tonight shows a few isolated showers across our northern
counties with dry conditions elsewhere. The remainder of the
overnight should be quiet as lingering showers dissipate. Skies
become mostly cloudy as low stratus currently over Georgia
spreads into the entire CWA. Low temperatures will be in the
lower 70s.

The Synoptic scale pattern remains largely unchanged today with
a trough to the north and west and a ridge to our south and
east. The southwesterly flow will continue to advect moisture
into the region with PWATs around 2 inches. A lingering frontal
boundary will continue to support the development of scattered
showers and thunderstorms today. Winds aloft will be stronger
than previous days partially mitigating the threat for flash
flooding. However, any showers and thunderstorms could producing
locally heavy rainfall so there is a non-zero risk of flash
flooding, especially if thunderstorms train over the same area
in quick succession. With CAPE values in excess of 1000 J/kg
and modeled soundings showing an inverted-V signature, there is
also a low (less than 20%) chance of a few strong wind gusts
being produced from any robust convection. The amount of
instability will be dictated by how much clearing can occur
after morning stratus scours out. Skies are expected to become
partly cloudy by midday allowing temperatures to rise into the
upper 80s to lower 90s, still slightly below normal for this
time of year. Latest guidance suggests that there will be a
higher rain threat this evening across the northern Midlands and
the highest PoPs of the day are in this area. Any convection
should gradually wind down with the loss of daytime heating.
Skies then become partly to mostly cloudy with lows in the lower
to mid 70s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
Key Message(s):

- Stagnant pattern persists with a continued potential for heavy
  rainfall

A stalled frontal boundary remains over The Midlands and CSRA early
this week. In addition a weak upper level trough over the Upper
Mississippi River Valley will rotate weak disturbances in a
southwest flow aloft and enhance diurnal convective activity.
Precipitable water values in excess of two inches provides the
continued risk of flash flooding. Wet antecedent soil conditions and
storm motion speeds of 15 mph or less will add to the flooding risk.
WPC has the region in a Marginal Risk of Excessive Rainfall for the
entire service area on Monday and the Northern and Western Midlands
on Tuesday.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Key Message(s):

- Subtle pattern change with a trend toward less rainfall and
  warmer temperatures

A persistent upper level trough over the Upper Mississippi River
Valley slowly lifts into the Great Lakes and then progresses
eastward during the latter half of the week. This should allow
high pressure aloft to build westward into the Southeast U.S.
Temperatures should gradually warm with rising H5 heights and
the chances of precipitation should decrease to climatological
norms for mid summer by the end of the forecast period.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
Ceiling Restrictions Possible at the Terminals this Morning....

Low clouds continue to build into the forecast area tonight
though ceiling restrictions are currently being observed
exclusively at CUB at the moment. TAFs continue to reflect the
likelihood of low stratus causing ceiling restrictions at all
terminals later tonight lingering into the mid-morning hours.
The low stratus will eventually scour out with scattered cumulus
developing as the day goes on. While scattered showers and
thunderstorms are possible later today, confidence is not high
enough to warrant their inclusion in the TAFs at this time.

EXTENDED AVIATION OUTLOOK...Thunderstorms likely each day and
may cause brief restrictions. Abundant low level moisture may
cause early morning restrictions through mid-week.

&&

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

&&

$$