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457
FXUS62 KCAE 251837
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
237 PM EDT Tue Jun 25 2024

.SYNOPSIS...
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Hot temperatures with heat indices over 100 F are expected to
continue through the period. Isolated to scattered showers and
thunderstorms should occur each afternoon and evening,
particularly in the eastern Midlands and coastal plain. As a
front approaches, better coverage is likely Thursday.
Increasing heat impacts Friday through the weekend. Another weak
front will move into near the area Monday with possible better
convective coverage.
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&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:
-Heat continues to hold on over the area with max heat indices
 over 100. A Heat Advisory is in effect for Orangeburg and
 Bamberg counties for heat indices near 110 this afternoon.

A moisture boundary remains draped across the area with a steep
dew point gradient of 5-10 degrees from Columbia to Orangeburg.
A scattered cu field is seen on the dry side of the moisture
gradient, but some more widespread cu is beginning to develop
across the I-95 corridor. Dew point depressions and mid-level
dry air will prevent any shower-storm activity this afternoon
across much of the Midlands, but in the deeper moisture in the
extreme eastern Midlands and coastal plain, a few pop up showers
and storms are likely. High temps should top our around 100
again with heat indices pushing 110 in the areas on the moist
side of the boundary.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
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KEY MESSAGES:
-Hot conditions to continue with max heat indices of 105-110
 likely on Wednesday.
-Isolated to scattered afternoon/early evening thunderstorms,
 greatest coverage in the southeast Midlands Wednesday.
-Highest chances of showers and thunderstorms Thursday, some
 possibly severe. Wind damage is the main threat.

Wednesday: Broad troughing to our north will steadily help
drive some weak height falls across the area as we move into
Wednesday. Moisture will pull northward as the lingering
boundary lifts along southerly low level flow. So much of the
area will yield dew points into the 70`s again as PWAT`s climb
to around 1.5". PWAT`s will be a bit limited by some weak
downsloping flow aloft and the relatively dry northwest flow
above 850mb but this allow for strong solar heating. So again
high temps will cruise into the upper 90`s or low 100`s and with
the enhanced moisture, heat indices will likely top out around
110; a heat advisory will likely be needed for parts of the
area. Shower and storm activity will remain generally confined
to the sea breeze and coastal plain, but will likely push
further west into the Midlands compared to Tuesday.

Thursday: Troughing will continue to dig across the eastern US
with an associated low pressure system and front dragging
southward towards our area. While the best height falls will
shift north of us across the Mid-Atlantic, low level moisture
and plenty of heating will allow for some modest destabilization
in the afternoon; even the over-mixed GEFS still yields a mean
near 1500 MU CAPE and near 1000 ML CAPE. So while the forecast
soundings are not extremely impressive for severe weather,
anytime we have a synoptic- mesoscale lift source, dew points in
the upper 60`s or 70`s, and high temps in the upper 90`s,
severe weather is possible.
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&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
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KEY MESSAGES:
-Increasing heat impacts expected Friday through the weekend
 with heat index values 105 to 110.
-Scattered afternoon thunderstorms each day.

Behind the boundary and trough passage on Thursday, broad flat
ridging will develop across much of the Southeast US. GEFS and
EC members are consistent in pulling the primary jet well north
across the Great Lakes, positioning us under the zonal,
slightly northwesterly flow regime of the ridge. Temps will
steadily climb each day through this period as the ridge builds
further and shifts east slightly. The warmest temps are expected
likely on Sunday with some downsloping component below 700mb in
the GEFS and EC means; NBM 75th percentile, which is verifying
well recently, is 100 F both Saturday and Sunday. Rain chances
increase sharply into Monday and Tuesday as the ridge breaks
down and more troughing digs to our north. Confidence is
relatively low on how this will materialize however given the
current pattern.
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&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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VFR conditions expected through the TAF period.

Dry air continues to keep only a thin scattered cu field for
AGS, DNL, CUB, and CAE. Deeper moisture at OGB is yielding some
widespread cu this afternoon. Winds will remain out of the east
through the afternoon and overnight, with some gusts to around
10-12 mph. An isolated shower-storm is possible near OGB later
this evening but confidence is low; VCTS is in through 21z but
confidence too low beyond that. Some fog- stratus is possible
at OGB Wednesday morning, but again too low confidence for TAF
mention yet.

EXTENDED AVIATION OUTLOOK...Chances start to increase for precip
and restrictions on Thursday and Friday.
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&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Heat Advisory until 6 PM EDT this evening for SCZ041-135>137.
GA...None.

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...