Special Weather Statement, NWS Columbia, SC

Area Forecast Discussion
National Weather Service Columbia SC
239 PM EDT Tue Jun 23 2020

.SYNOPSIS...
The chance of showers and thunderstorms will continue through
mid to late week as moisture and the next frontal boundary move
into the region. Temperatures will be near or above normal.

&&

.NEAR TERM /THROUGH TONIGHT/...
An upper trough over the Great Lakes region will gradually move
eastward while a shortwave rotates through the base of the
trough through the forecast area late this afternoon. Deep
moisture is in place across the area with pwat values around 1.8
to 2.0 inches. The moist airmass combined with heating and the
presence of a lee- side trough will allow isolated to scattered
showers and thunderstorms to develop early this afternoon. Radar
shows the convection associated with the trough as of 1830Z
extending through the western Carolinas into central GA. This
broken line is expected to continue to move eastward and into
the forecast area by late afternoon. The forecast area is
outlooked in a marginal risk for severe weather by SPC, but the
overall severe threat appears low. Damaging winds are the
primary severe threat, although DCAPE is currently unimpressive
at 400 to 500 J/kg. Instability appears weak and shear is weak.
Convective activity and wind gusts should diminish during the
evening as the shortwave moves out and the conditional
instability is lost. Overnight lows around 70.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Wednesday morning, one short wave will have moved offshore, but a
streamer of vorticity will hang back across the southern half of the
area as another shortwave follows closely on its heels within the
eastern North America large scale trough. At the surface, a weak
front will sag into South Carolina from the north, but will likely
stall across the northern parts of the FA, keeping most of us in a
warm and humid airmass, which will become moderately unstable by
afternoon. As the aforementioned shortwave approaches, more showers
and thunderstorms are expected to develop, with the best chances
along and south of the weak front.

By the late afternoon and evening, winds in the 850-500 mb layer
will increase somewhat, so its possible the convection would form
into multicell clusters with some organization. Were that to happen,
a few severe storms would be possible.

Wednesday night, lingering convection should be done by midnight as
the upper energy moves away and diurnal effects diminish the
instability.

On Thursday, the deepest moisture will pull away from the
southeastern states as heights slowly build aloft. The surface front
will have moved out by then as well, so the chances of convection
should drop down to the lower end of the chance category. The air
mass will be a touch cooler, and winds will pick up a little, so
conditions will not be overly oppressive.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Heights will continue to build aloft Friday into the weekend as
the low level bermuda high builds westward across northern
Florida and the northern Gulf of Mexico. Low level temps will be
on the rise as well, with highs expected to be at least mid 90s
in many places. Chances of rain will be lower due to large
scale subsidence, but the near surface thermal trof could still
be the focus for a few scattered thunderstorms by late each day.

The one fly in the ointment for the weekend is the eventual
evolution of the SAL dust over the area. Mid layer trajectories
would suggest that some of that may work its way into the FA,
especially by Sunday. Were this to happen, it could potentially
knock down max temps by a couple of degrees and make the chances of
rain even lower by enhancing the expected low level cap. It's too
early in the forecast cycle to get too cute, however, as the amount
and timing is still uncertain.

Early next week, a cutoff low is forecast to develop by the global
models over eastern Canada and New England. However, there is some
question as to how far south the influence of the cutoff will get.
If it becomes deep enough, it could drive a cold front through the
area from the north. While this is possible, it could also struggle
to get into South Carolina and Georgia, given the region a hot and
dry pattern. I'm going with a near seasonable forecast for now.
Also, some effects from the SAL may still be in play.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
VFR conditions expected outside of afternoon/evening convection.

Isolated to scattered thunderstorms should develop in the early
afternoon due to the warm, moist airmass. Radar showing a line
of mainly showers extending from western NC through central GA
which is expected to track towards region later this afternoon
with convective coverage increasing. Most of the convection will
diminish with loss of heating this evening. Winds will continue
out of the southwest through the afternoon at around 12 knots
gusting to 18 to 20 knots. Higher gusts possible in
thunderstorms. Fog potential is low tonight due to a 20 know low
level jet and clouds.

EXTENDED AVIATION OUTLOOK...CIG/VSBY conditions through the end of the week
will be mainly impacted by scattered afternoon/evening convection.
Some dust may make it into the area over the weekend, but at the
current time I am not expecting anything but VFR vsbys from the
SAL.

&&

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

&&

Hazardous Weather Outlook
National Weather Service Columbia SC
322 AM EDT Tue Jun 23 2020

GAZ040-063>065-077-SCZ016-018-020>022-025>031-035>038-041-115-116-
240730-
Lincoln-McDuffie-Columbia-Richmond-Burke-Chesterfield-McCormick-
Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington-Richland-Lee-
Aiken-Sumter-Barnwell-Orangeburg-Calhoun-Clarendon-Bamberg-
Northern Lancaster-Southern Lancaster-
322 AM EDT Tue Jun 23 2020

This Hazardous Weather Outlook is for the Midlands of South Carolina
and the Central Savannah River area of Georgia.

.DAY ONE...Today and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service Columbia SC
349 PM EDT Tue Jun 23 2020

SCZ020-026-232045-
Newberry SC-Saluda SC-
349 PM EDT Tue Jun 23 2020

...Strong Thunderstorms Will Impact Portions of Newberry and Saluda
Counties Until 445 PM EDT....

...Boaters on Lake Murray Should Seek Safe Harbor...

At 348 PM EDT...National Weather Service doppler radar indicated
strong thunderstorms along a line extending from 6 miles northeast of
Clinton to 9 miles southwest of Newberry College to 9 miles northwest
of Saluda County Airport, moving east at 20 mph.

  HAZARD...gusty winds 40 to 50 mph.

  IMPACT...expect minor damage to tree limbs and blowing around of
           light, unsecured objects.

Some locations in the path of these storms include...
Newberry, Saluda, Whitmire, Prosperity, Ridge Spring, Saluda County
Airport, Newberry College, Newberry County Airport, Dreher Island
State Park, Blair, Little Mountain, Monetta, Pomaria, Silverstreet,
Ward, Peak, Saluda Co Sheriff's Office, US-176 and SC-
34 Crossroads, Good Hope and Hollywood Elementary School.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters on Lake Murray should move to shore and seek shelter. Strong,
erratic wind gusts and lightning are possible. If you can hear
thunder, you are close enough to be struck by lightning.

&&

This includes Interstate 26 between mile markers 62 and 89.

LAT...LON 3413 8187 3420 8184 3433 8185 3437 8178
      3453 8165 3445 8154 3449 8149 3449 8143
      3424 8132 3420 8134 3417 8141 3412 8143
      3409 8140 3409 8147 3386 8160 3384 8162
      3388 8185 3398 8190 3396 8201
TIME...MOT...LOC 1948Z 264DEG 18KT 3454 8177 3421 8175 3398 8194