598
FXUS62 KCAE 201651
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
1251 PM EDT Thu Jun 20 2024

.SYNOPSIS...
Dry weather and near normal temperatures will continue through
tonight as synoptic situation remains relatively unchanged.
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/...
With little change in the overall pattern and the surface high
remaining in control of the region another day of cumulus with
limited vertical development is upon us. The 12z CHS sounding
once again showed a strong subsidence inversion and based on
current clouds expect the inversion to persist through tonight.
This will result in cumulus developing through early this
evening then dissipating with the loss of heating. Temperatures
across the area are currently in the upper 80s and remain on
track for the low 90s at most locations. Easterly winds at 5 to
10 mph with gusts up to 20 mph will continue through the
afternoon then diminish this evening becoming light and
variable overnight. With good radiational cooling tonight
overnight lows will be in the mid to upper 60s.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
An area of low pressure east of the Bahamas, Invest 92L, 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 THURSDAY/...
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 /18Z THURSDAY THROUGH TUESDAY/...
VFR conditions expected through the TAF period.

High pressure remains in control of the region with scattered
cumulus again across the area. Little will change is expected
through tonight which will result in the cumulus dissipating
toward sunset with the easterly winds also diminishing. Friday
morning the situation will begin changing as a weak tropical
wave moves toward the coast of eastern GA and NE FL. This will
spread moisture into AGS/DNL/OGB during the morning and CAE/CUB
during the early afternoon. Convection will be possible very
late in the period however confidence remains too low in timing
and coverage to include attm.

EXTENDED AVIATION OUTLOOK...Brief restrictions possible in
isolated to scattered afternoon and evening thunderstorms Friday
and Saturday with increasing chances Sunday through Tuesday.

&&

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

&&

$$