Area Forecast Discussion
Issued by NWS Charleston, SC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KCHS 201512
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1112 AM EDT Thu Jun 20 2019

.SYNOPSIS...
A trough of low pressure will persist over the Southeast
through at least the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Main changes with the latest update were to back off on
timing of rain chances a bit. Otherwise, moderate confidence
remains in some severe thunderstorms from late afternoon through
early evening, generally from about 4 to 8 pm closer to the
Midlands/CSRA and from about 6 to 10 pm near the coast. An
approaching upper shortwave trough will cause an increase in
wind fields across the region and moderate instability is expected
to develop across southeast SC/GA. Damaging winds appear to be
the greatest hazard with the storms although large hail and/or
tornadoes are also possible. It will become breezy even before
any storms arrive with gusts near 30 mph at times. Highs should
be in the lower to mid 90s inland with heat indices near 100
degrees, possibly even closer to 105 degrees south of I-16 and
near/west of I-95.

Tonight: Convection should be pushing offshore this evening, at
least the strongest of the storms, with decreasing chances for
showers and weak tstms after midnight. Lows should be in the
lower to mid 70s inland and upper 70s near the coast.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Friday: Guidance depicts drier air spreading across the forecast
area from the north/northeast. Cannot rule out an isolated
shower/thunderstorm across far southern/inland counties Friday
afternoon, but latest trends suggest that most, if not all,
locations should remain rain-free, so maximum PoPs are capped below
15 percent with no mention of diurnal convection. Above-normal
temperatures are expected to peak in the middle 90s at most
locations away from the beaches, and dewpoints in the 70s could
contribute to heat index values around 105F across far southern
counties. Thus, per our lower criteria prior to July 1, a Heat
Advisory could be required across SE GA counties mainly
south/southwest of Savannah. With continued rain-free conditions,
Friday night temperatures will remain in the 70s most areas and
could hold close to 80F on the beaches.

Saturday and Sunday: Hot and humid conditions will prevail. High
temperatures should average in the middle 90s at most locations, and
dewpoints in the 70s will spread deeper into the forecast area. As a
result, maximum heat index values around 105F are possible at many
locations, and Heat Advisories could be required. Meanwhile, expect
greater coverage of convection, especially during the afternoon/
evening hours both days. Afternoon/evening PoPs average 30-50
percent, and MLCape values as high as 2500-3500 j/kg suggest some
potential for brief/isolated pulse severe thunderstorms with
damaging wind gusts.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Weak troughing at the surface and aloft will persist through at
least the middle of next week. Guidance continues to depict above-
normal temperatures. Interestingly, despite the trough, medium range
guidance suggests that coverage of diurnal convection could become
sparse next week, resulting in below-normal daily PoPs.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
Periods of MVFR cigs around the coastal corridor through mid
morning. Risk for tstms will increase at both KCHS and KSAV
toward evening, mainly 23-01Z.

Extended Aviation Outlook: Mainly VFR.

&&

.MARINE...
Today/Tonight: We have expanded the Small Craft Advisory into
the southern SC nearshore waters and it will be close even
across the nearshore GA waters. Stronger storms could produce
significant impacts early-mid this evening with strong winds and
possible large hail/waterspouts. Seas will range from 3-5 ft
within 20 NM with some 6 ft seas off the Charleston County coast
and over the outer GA waters.

Friday through Tuesday: South to southwest winds and associated seas
are expected to remain below Small Craft Advisory levels through
this period. Seas as high as 4-5 feet to start Friday will settle
back to 1-3 feet much of the time through early next week. Winds
gusting as high as 20 knots Friday should remain mainly 15 knots or
less for the remainder of this period.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for AMZ330.
     Small Craft Advisory until 2 AM EDT Friday for AMZ350-352.
     Small Craft Advisory until 6 AM EDT Friday for AMZ374.

&&

$$
NEAR TERM...RJB
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.