152
FXUS62 KCAE 200829
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
429 AM EDT Thu Jun 20 2024

.SYNOPSIS...
High pressure along with dry weather and near normal
temperatures are expected through today. Unsettled conditions
are possible tomorrow and into the weekend as moisture moves in
from the Atlantic. Well above normal temperatures are expected
by Sunday into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Skies are clear to mostly clear across the forecast area tonight
with scattered high clouds over the northern and western counties
and a few patchy stratocumulus drifting in from the east. Calm or
light easterly winds will continue through the overnight hours. Lows
tonight will be in the mid to upper 60s.

There is little change in the overall large scale pattern as upper
ridging and high pressure centered to our northeast continue to
dominate the weather. Expect another day of warm and dry weather
conditions as PWATs struggle to exceed 1 inch. Scattered cumulus are
likely to develop along with periodically gusty winds out of the
east. Any cumulus should dissipate with the loss of daytime heating
giving way to mainly clear skies tonight. Clouds may increase
towards daybreak as an area of low pressure, Invest 92L, approaches
the coast but rain is not expected until after daybreak.
Temperatures will be similar to previous days with highs around 90
degrees and lows in the mid to upper 60s.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
An area of low pressure east of the Bahamas is expected to move
south of the region Friday. The NHC Tropical Weather Outlook gives
it a low (30%) chance for further development in the next 48 hours.
The expectation is that this disturbance will remain disorganized,
but infuse more moisture into the region to support a chance of
showers and thunderstorms on Friday afternoon, mainly south of the I-
20 corridor. The moisture increase will be significant, with PW
values exceeding 1.5" and approaching 1.8" by late Friday afternoon
across the Southeast Midlands and CSRA. Additionally, temperatures
will be warmer than Thursday by a few degrees, with highs in the low
to mid 90s as a potent upper ridge and broad surface high pressure
situate over the TN Valley. The increased moisture will also lead to
more cloud cover and warmer overnight lows, mainly in the upper 60s
to around 70.

A warming trend really kicks into gear on Saturday, with highs
reaching the middle 90s to perhaps the upper 90s for a few
locations. Changes in the wind field, with more southerly flow in
the lower levels, will reinforce moisture availability and dewpoints
are expected to creep into the upper 60s to low 70s possible across
the southeast Midlands. However, this will be countered by northerly
flow aloft, as a mid and upper level low sets up off the coast of
NC. With PW values around 1.5"-1.7", daytime heating should
trigger isolated diurnally-driven convection across the area.
Storms should wind down with sunset, and overnight lows will be
mild again, only in the low 70s.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The main story in the extended forecast remains the heat. While
moisture will remain intact across the area with PW around 100-120%
of normal, its effect on apparent temperatures will be more
impactful than the increased risk for showers and thunderstorms.

Upper ridging will build across the southern tier of the CONUS and
remain in control into early next week. GEFS mean 850mb temperatures
are forecast to be 18-22C through the middle of next week, giving us
temperatures of 8-12 degrees above normal at the surface. There has
been little change in the overall high temperature forecast from the
NBM or the spread through at least Monday, though it should be noted
that the deterministic NBM highs on Monday seem to be at the 25th
percentile. The spread on Tuesday is wider, likely due to the
uncertainty regarding any convection which may interfere with peak
heating potential. Potent low level moisture (dew points in the
upper 60s and low 70s) is thought to yield max heat indices of 98F-
103F across the region, especially for Sunday through Tuesday. Its
also worth mentioning warm overnight lows, in the low to mid 70s.

There remains uncertainty for Tuesday and Wednesday as the pattern
shifts with a couple of disturbances moving through the region.
Ensemble PW means differ between the GEFS and the ECENS, with
the EC quite a bit drier than the consistently wet GEFS. Didn`t
deviate from the blend at this juncture since there is too much
uncertainty. Overall though, it does look like we`ll be entering
into a more active and summer-like pattern at temperatures
remain well above normal.

More information on the potential for moderate to major heat risk
late in the forecast period can be found at
wpc.ncep.noaa.gov/heatrisk.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...

VFR conditions continue at the terminals tonight with passing
cirriform clouds coming in from the northeast and a few
stratocumulus arriving from the east. Easterly flow continues
and will likely persist through the TAF period. A moderate low-
level jet should prevent fog development once again tonight.

Winds should increase after daybreak and may be gusty at times,
especially this afternoon. Dry conditions are likely to continue
at all terminals with passing scattered cumulus dissipating
after sunset. Winds should gradually diminish tonight under
clear skies though cloudiness may begin to approach the
terminals from the east towards the end of the current TAF
period.

EXTENDED AVIATION OUTLOOK...Brief restrictions possible in
isolated to scattered afternoon and evening thunderstorms Friday
through Sunday.

&&

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

&&

$$