Area Forecast Discussion
Issued by NWS Columbia, SC

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FXUS62 KCAE 170234
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
1034 PM EDT Wed Aug 16 2017

.SYNOPSIS...
Moisture will remain high with a pressure trough in the
forecast area through Friday. The trough and heating will help
support thunderstorms but coverage should remain limited
because of upper ridging. This ridging will help support hot
conditions with heat index values peaking around 102 to 108
into the weekend. Another cold front will approach later in the
weekend.

&&

.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
Upper ridging will continue over the Southeastern CONUS
overnight. At the surface, a weak trough will remain over the
region. Regional radar this evening shows a few small isolated
showers and thunderstorms. Lingering convection should continue
to weaken and dissipate later this evening. Convection upstream
may bring some higher clouds over the area tonight but those
should thin with time. Temperatures will be warm overnight
after such a hot day with lows in the mid to upper 70s. Patchy
fog mainly in fog prone locations will be possible toward
daybreak Thursday.

&&

.SHORT TERM /8 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
Upper ridge over the southeastern States will remain on
Thursday into portions of Friday. The ridge will become
suppressed southward Friday evening into Saturday ahead of a
deeper trough that will be moving eastward through the Great
Lakes and the Ohio River Valley region. Even with the expected
ridging there should still be enough low-level moisture during
the afternoons Thursday and Friday to aid in the development of
isolated to scattered showers and thunderstorms. As the upper
trough moves towards the area on Saturday, a weak front will
approach from the northwest during the day, helping to produce
additions scattered storms. For each afternoon, can not rule
out brief heavy rainfall in any activity that develops due to
pwat values still hovering around 2 inches across the area.
Afternoon temperatures are expected to be hot, climbing into at
least the middle 90s each day. This heat will combine with the
humidity to cause high heat index readings. While readings are
still expected to remain below local office advisory criteria of
110 degrees, many areas are expected to see heat index vales on
Thursday between 105 and 109 degrees, and readings Friday and
Saturday only slightly cooler.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Surface front will still be off to the north of the cwa on
Sunday, but will be slowly moving southward into Monday. Aloft,
the upper trough will move east of the region, allowing the
upper ridge to build back into the area by the beginning of the
work week. The surface front should be across the cwa on Monday
morning, continuing the slow track southward before stalling
out just south of the cwa by Tuesday. The exact location of the
front, and any slightly drier air behind it, will have an
impact on cloud cover and precip potential for Monday. Models
do show moisture during the morning hours, with some potential
drying as the day progresses across the north and central cwa.
Can not rule out isolated to scattered activity on Monday,
especially in areas closer to the frontal position. Additional
drying possible on Tuesday, with mainly isolated convection.
Temperatures still at or above normal each afternoon, with
maximum heat index values in the upper 90s to lower 100s during
the rest of the period.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Generally VFR conditions through the period.

Diminishing convection across the region no longer threatening the
TAF sites. Could see mid and high level debris clouds from
upstream convection cross the area overnight. Some models
indicated MVFR fog at AGS/OGB 09Z-12Z. Given near calm winds
coupled with low level moisture and mostly clear skies
overnight...have indicated MVFR fog at AGS and OGB around
sunrise. Scattered convection expected to develop Thursday
afternoon. Have not included convection in TAFs given low
probability of affecting any one terminal.

EXTENDED AVIATION OUTLOOK...Scattered mainly afternoon and evening
showers and thunderstorms possible each day. Also, low-level
moisture could result in early morning fog and/or stratus.

&&

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

&&

$$



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