Area Forecast Discussion
Issued by NWS Columbia, SC

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FXUS62 KCAE 220519
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
119 AM EDT Sat Jul 22 2017

.SYNOPSIS...
Upper ridging will remain over the forecast area through
Saturday then weaken Sunday into early next week. Along with the
troughing moisture will increase across the area with slowly
increasing chances of thunderstorms through Tuesday. It will
remain hot over the weekend with heat index values peaking
between 105 and 110 degrees.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
Storms have ended and mostly clear skies with generally light
winds can be expected overnight. Low temperatures will be slightly
warmer than last night, with mid 70s expected.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
Ridge from the Bermuda high will remain over the northern Gulf
Coast with the upper level trough digging into the eastern US
late Saturday and Sunday. First concern for Saturday will be the
heat index as temperatures will rise to the upper 90s to around
100 and push heat index values to 105 to 109. This will be just
shy of criteria for a heat advisory of 110...so will continue to
mention in HWO and discussions with no special products issued.
Next concern will be potential for thunderstorms...and with the
lack of a strong trigger will again depend on diurnal heating.
Thus expect slight chance to low chance pops through the
afternoon and evening hours with the best chances over the
western Midlands where the upper troughing will show the effects
first and along the sea breeze. On Sunday as the upper trough
swings closer to the forecast area and PWAT values again reach 2
inches expect chance pops with the highest chance over the Pee
Dee and western Midlands where some dynamic lift from the upper
trough will trigger convection. With freezing levels AOA 14 kft
main threat will remain damaging wind gusts. Temperatures will
be in the mid 90s to around 100 Saturday with mid 90s on
Sunday...overnight lows will generally be in the mid 70s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Few changes made to the long term forecast as the ridging from
the Bermuda high pushes southward into the Gulf of Mexico and
upper level troughing digs over the eastern US. By mid week the
trough subsides slightly...only to deepen again from Wednesday
onward. With the forecast area between these two features and
PWAT values remaining near 2 inches will see chances of
thunderstorms each day. Models indicate potential for a weak
surface boundary to develop Tuesday through Thursday and with
the upper level trough deepening could see some short waves
enter the area. This would result in increased pops...and with
confidence low in this scenario have remained with chance pops.
Temperatures will moderate somewhat through the long term with
near normal temperatures...afternoon highs in the low to mid
90s.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Showers and storms have ended and skies will be mostly clear
overnight with only a few mid-level clouds lingering. Do not
expect early morning fog development for most of the area due to
a 20 knot low level jet which should promote mixing in the
boundary layer, but cannot rule out brief MVFR restrictions at
fog prone AGS. Have kept tempo group at AGS from 09Z/12Z.
Expect scattered showers and thunderstorms to develop again on
Saturday afternoon/evening, but coverage is too uncertain at
this time to include in TAFs.

EXTENDED AVIATION OUTLOOK...Increasing chances of afternoon/evening
thunderstorms, and late night/early morning fog/stratus,
Monday/Tuesday.

&&

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

&&

$$



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