Special Weather Statement, NWS Columbia, SC

Area Forecast Discussion
National Weather Service Columbia SC
1206 PM EDT Tue Aug 7 2018

.SYNOPSIS...
An upper ridge will extend westward from the Atlantic into our
region through Thursday. This will allow a return to more
typical summerlike weather with scattered mainly afternoon and
evening thunderstorms, along with a warming trend. The upper
ridge will gradually weaken late this week into this weekend as
an upper trough digs into the eastern US.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Upper ridging will continue over the Southeastern CONUS this
afternoon. At the surface morning analysis shows a weak lee
side trough across the Upstate. PW values range from the 1.7
inches across the Upstate to 1.9 across the central/eastern
Midlands/CSRA. Dewpoint values are quite impressive again today
with many areas in the middle 70s. This will push Heat
Index/Apparent Temperature values to around 105 degrees. Models
are a bit mixed on coverage of convection this afternoon. The
GFS/NAM pops are from 15 to 25 percent with only widely
scattered shra/tsra at best. Some of the higher resolution
models show more coverage across the area that begins to develop
during the early afternoon hours and continues into early this
evening. Have stayed in the middle, as today has begun much
slower than yesterday with cu development and convection. Main
threat today will once again be locally heavy rainfall and the
possibility of an isolated strong wind event. Expect afternoon
temperatures to max out in the lower/middle 90s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
Center of the upper ridge remains off to the south of the cwa
through the period, with upper flow around the high keeping a
western wind pattern. Lingering rainfall this evening should
once again be dissipated by Midnight. Then for Wednesday,
redevelopment of scattered afternoon and evening showers and
storms along a weak lee side trough. Storms will be aided by
weak short wave energy moving around the northern portions of
the ridge. High temperatures will climb into the lower to mid
90s on Wednesday, with heat index values between 100 and 105.
Overnight lows in the lower to mid 70s expected.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Energy moving through the main upper trough north of the area
will mainly remain north of the area as it moves through the
Mid-Atlantic and New England states Thursday. Further west
across the lower Mississippi River region, digging energy on the
backside of the trough will begin pushing east by Friday, then
move through the cwa Friday afternoon and night. Behind that
piece of energy, a deeper trough will then settle in across the
eastern US into the weekend. Precipitation chances will
increase over the weekend as a result, but the bulk of
convection is expected to remain diurnally driven. High
temperatures should be near or even slightly below normal
through the long term period given the increased rain chances
and potential for cloud cover.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
VFR conditions have returned to all TAF sites after some morning
fog/low ceilings at both OGB/AGS. Isolated/Widely scattered
shra/tsra are expected to develop this afternoon but timing and
coverage are too uncertain to include in the terminal forecast
at this time. Light winds will become more south/southwest
around 6 kts this afternoon. For tonight, a 15 to 20 knot low
level jet may help limit development of fog.

EXTENDED AVIATION OUTLOOK...Mainly diurnal scattered
thunderstorms are forecast each day. Widespread stratus and fog
may occur during the late nights and early mornings.

&&

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

&&

SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99

Hazardous Weather Outlook
National Weather Service Columbia SC
320 AM EDT Tue Aug 7 2018

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-080730-
Lincoln-McDuffie-Columbia-Richmond-Burke-Lancaster-Chesterfield-
McCormick-Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington-
Richland-Lee-Aiken-Sumter-Barnwell-Orangeburg-Calhoun-Clarendon-
Bamberg-
320 AM EDT Tue Aug 7 2018

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
245 PM EDT TUE AUG 7 2018

SCZ027-028-071930-
Lexington SC-Richland SC-
245 PM EDT TUE AUG 7 2018

...Strong Thunderstorms Will Impact Portions of central Lexington and
central Richland Counties Until 330 PM EDT....

At 244 PM EDT...National Weather Service doppler radar indicated a
strong thunderstorm over Oak Grove, moving east at 10 mph.

  HAZARD...gusty winds 35 to 45 mph, excessive cloud to ground
           lightning and localized minor flooding.

  IMPACT...expect minor damage to tree limbs and blowing around of
           light, unsecured objects. All outdoor activities should
           cease. Move indoors immediately. Localized, minor
           flooding of low lying and poor drainage areas is also
           possible.

Some locations in the path of this storm include...
Columbia, Lexington, West Columbia, Cayce, Forest Acres, Springdale,
Oak Grove, Red Bank, St. Andrews, South Congaree, Pine Ridge, Arcadia
Lakes, Five Points, Woodfield and Seven Oaks.

Heavy rainfall is occurring with this storm, and may cause localized
flooding. Do not drive your vehicle through flooded roadways.

Move indoors immediately.  Excessive cloud to ground lightning is
occurring with this storm. If you can hear thunder, you are close
enough to be struck by lightning.

This includes the following highways...
 Interstate 126 between mile markers 1 and 3.
 Interstate 20 in South Carolina between mile markers 50 and 62.
 Interstate 26 between mile markers 108 and 120.
 Interstate 77 between mile markers 0 and 15.

LAT...LON 3385 8097 3386 8100 3388 8100 3388 8102
      3387 8104 3384 8104 3388 8129 3396 8134
      3402 8118 3406 8090
TIME...MOT...LOC 1844Z 276DEG 8KT 3396 8116

HC