Special Weather Statement, NWS Columbia, SC

Area Forecast Discussion
National Weather Service Columbia SC
152 PM EDT Sat Aug 21 2021

.SYNOPSIS...
An upper trough will settle over the Mid-Atlantic region through
the weekend keeping chances of afternoon and evening convection
in the forecast and directing Henri northward away from the
Carolina coast. The upper ridge over the middle of the country
will build eastward early next week bringing a return to typical
summer like conditions.

&&

.NEAR TERM /THROUGH TONIGHT/...
Scattered convection has developed just south of Columbia and
extending towards Orangeburg. Mean flow is southeasterly, but more
storms will continue to pop up along outflow boundaries through the
afternoon. Storms will tend to favor the CSRA and southern Midlands
where a tight PWAT gradient exists along a weak boundary. Moderate
instability throughout the region and DCAPE around 1000 suggest
there is a low chance of some strong wind gusts within
thunderstorms, however severe threat remains low. Hi res guidance
shows convection continuing within this area of heightened moisture
through the evening hours with an isolated shower possible prior to
midnight. Mid and low level moisture will wrap around the upper
level trough overnight and into the area from the southwest. This
low stratus will keep temperatures from falling to climatology
with overnight lows in the mid to upper 70s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The main upper low that has been located just north of the
region will remain through Sunday night, then the low begins
lifting northeastward and the trough axis pushes off the
Carolina coasts on Monday. Upper ridge west of the area will
begin to build a little further eastward, keeping a general
northwesterly upper flow pattern. Models still indicating some
scattered convection possible Sunday from late morning through
much of the afternoon. Additional showers/storms remain possible
on Monday, but highest rain chances should be confined closer to
the coast.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Region should remain between strong upper ridge to the west and
another ridge across the western Atlantic. This keeps a weak
upper trough axis in the immediate area. Guidance shows a
shortwave moving westward along the southern portions of the
Atlantic ridge into Thursday, and this should bring deeper
moisture into the area. Rain chances increase during the
afternoon hours each day, with scattered to numerous showers and
storms expected each afternoon. Temperatures should remain near
or slightly below normal.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Scattered convection will continue through the afternoon along
with associated restrictions, mainly along OGB/AGS/DNL. Tonight,
thunderstorms will become more isolated by 00z and winds will
become light and variable. Moisture will increase from the
southwest through the night bringing potential stratus deck into
the TAF sites. MVFR visibility and ceiling restrictions towards
daybreak with intermittent IFR possible. Low confidence at this
time on timing of improvement.

EXTENDED AVIATION OUTLOOK...Late night/early morning
fog/stratus restrictions possible through Monday as moisture
returns. Mainly afternoon and evening convection along with
associated restrictions possible each day.

&&

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

&&

Hazardous Weather Outlook
National Weather Service Columbia SC
341 AM EDT Sat Aug 21 2021

GAZ040-063>065-077-SCZ016-018-020>022-025>031-035-037-038-041-115-
116-135>137-220745-
Lincoln-McDuffie-Columbia-Richmond-Burke-Chesterfield-McCormick-
Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington-Richland-Lee-
Aiken-Sumter-Barnwell-Calhoun-Clarendon-Bamberg-Northern Lancaster-
Southern Lancaster-Northwestern Orangeburg-Central Orangeburg-
Southeastern Orangeburg-
341 AM EDT Sat Aug 21 2021

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...Sunday through Friday.

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
126 PM EDT Sat Aug 21 2021

SCZ027-028-030-135-211830-
Lexington SC-Aiken SC-Richland SC-Northwestern Orangeburg SC-
126 PM EDT Sat Aug 21 2021

...A strong thunderstorm will impact portions of southern Lexington,
northeastern Aiken, northwestern Orangeburg and southwestern Richland
Counties through 230 PM EDT...

At 124 PM EDT, Doppler radar was tracking a cluster of strong
thunderstorms across southern Lexington county and northern Aiken
county, with limited movement.

HAZARD...Winds in excess of 40 mph and heavy rainfall.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.  Heavy rainfall could cause ponding of
         water on area roadways.

Locations impacted include...
Lexington, Cayce, Batesburg-Leesville, Springdale, Red Bank, South
Congaree, Pine Ridge, Gaston, SC State Farmer's Market, Columbia
Metro Airport, Wagener, Pelion, Gilbert, Summit, Perry, Murray, Thor,
Camp Kinard, New Holland and Samaria Fire Station.

This includes the following highways...
 Interstate 20 in South Carolina between mile markers 30 and 55.
 Interstate 26 between mile markers 115 and 119.
 Interstate 77 between mile markers 0 and 1.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3368 8158 3402 8148 3392 8101 3361 8123
TIME...MOT...LOC 1724Z 282DEG 19KT 3372 8120

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

Special Weather Statement
National Weather Service Columbia SC
236 PM EDT Sat Aug 21 2021

SCZ035-041-137-211900-
Barnwell SC-Southeastern Orangeburg SC-Bamberg SC-
236 PM EDT Sat Aug 21 2021

...A strong thunderstorm will impact portions of east central
Barnwell, Bamberg and southwestern Orangeburg Counties through 300 PM
EDT...

At 236 PM EDT, Doppler radar was tracking a strong thunderstorm over
Denmark, moving southeast at 15 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3310 8118 3331 8131 3341 8116 3338 8111
      3338 8108 3334 8102 3334 8101 3331 8094
      3327 8090 3328 8088 3307 8114
TIME...MOT...LOC 1836Z 320DEG 13KT 3331 8119

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

NS