Special Weather Statement, NWS Columbia, SC

Area Forecast Discussion
National Weather Service Columbia SC
452 PM EDT Fri Jun 15 2018

.SYNOPSIS...
Weak frontal boundary over the Midlands and Pee Dee will slowly
move southward today and stall near the CSRA Saturday. High
pressure and a building upper level ridge will control the
region for Sunday into late next week. This scenario will keep
chances of mainly afternoon and evening thunderstorms in the
forecast with rising temperatures through late next week.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A frontal boundary/dewpoint gradient is situated across the
Midlands this afternoon. A warm moist airmass along and south of
the front has allowed for convective development. Dry air aloft
will inhibit widespread, deep convection although convergence
along the advancing frontal boundary and sea-breeze is
triggering pulse-type thunderstorms. Most of the activity is
currently focused from Aiken County eastward through Orangeburg
County, and into Calhoun County. Instability is moderate to
strong, and any stronger storms that develop will pose a threat
of severe weather. DCAPE values up to 1300 J/KG and wetbulb zero
heights between 10 and 11 kft suggest that both damaging
downburst winds and large hail are threats. Expect the highest
coverage and strongest thunderstorms to develop in eastern SC
where the upper levels aren't as dry.

Latest HRRR suggests activity could persist through the late
evening and overnight hours, but will die off by early morning.

High temperatures this afternoon will be in the mid 90s with
overnight lows in the low to mid 70s.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
Upper level ridge over the MS River Valley will slowly build east
Saturday as the upper trough off the east coast moves out to sea.
The remains of a surface front will be near the CSRA on Saturday
and continue acting as a focusing mechanism for diurnal convection.
Instability will continue in the moderate to strong range with DCAPE
again around 1000 J/KG and pwat values of 1.7 inches. Still expect
afternoon and evening thunderstorms...with a better chance across
the southern Midlands and CSRA. Strong winds and locally heavy
rainfall be will the main threats. Hail potential will be lower
Saturday as wet bulb zero heights will be higher.

Saturday night through Sunday will see the upper level ridge build
over the area with the ridge axis centered over the forecast area
Sunday night. At the surface high pressure will move north of the
area Saturday night and be located offshore of the Carolinas Sunday
and Sunday night. With the remains of the front south of the area
and high pressure pushing slightly drier air into the region Sunday
and Sunday night...thunderstorm chances will be lower with slight
chance over the northern Midlands and chance farther south.

Temperatures will be in the low to mid 90s for afternoon highs with
low to mid 70s for overnight lows.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Upper level ridge over the region Monday and Tuesday will be
suppressed south and west Wednesday through Friday as an upper
trough crosses the northeastern states. Surface high pressure
over the western Atlantic will ridge into the southeastern
states with a lee side trough over the Carolinas. Main concern
for the first half of next week will be hot temperatures with
highs in the mid to upper 90s and lows in the low to mid 70s.
Should see heat indices between 100F and 110F. Scattered
diurnal thunderstorms expected Monday through Wednesday.

Several weak short waves moving through area on the east side of the
upper ridge Thursday and Friday will increase the chance for showers
and thunderstorms for the end of next week...as a frontal boundary
drops south into the Mid Atlantic region. May see slight
cooling by Friday but temperatures will remain above normal
through the long term.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
VFR conditions expected outside of scattered diurnal convection.

A weak front will remain over the area this afternoon,
triggering thunderstorms, mainly to the south. Widespread
thunderstorms are unlikely given the upper level dry air. This
will keep confidence low that thunderstorms will impact the TAF
sites. OGB is the most likely to experience activity, but
currently convection is moving south of the site. However,
strong outflow winds are possible at all sites from nearby
convection. Thunderstorms will continue to develop through the
evening but diminish after 03Z. Otherwise, winds will be light
and variable through much of the period.

Tonight, a 20 kt LLJ will inhibit widespread fog although we
cannot rule out a brief period of visibility restriction at fog
prone OGB and AGS. Model trends have shown good agreement in
predominantly VFR conditions.

Saturday through 18Z, light easterly winds will pick up around
15Z with a scattered cumulus deck developing late morning.

EXTENDED AVIATION OUTLOOK...There may be restrictions in
stratus and fog during the early morning hours and also in
mainly afternoon and evening thunderstorms through Tuesday.

&&

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

&&

Hazardous Weather Outlook
National Weather Service Columbia SC
507 AM EDT Fri Jun 15 2018

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-160915-
Lincoln-McDuffie-Columbia-Richmond-Burke-Lancaster-Chesterfield-
McCormick-Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington-
Richland-Lee-Aiken-Sumter-Barnwell-Orangeburg-Calhoun-Clarendon-
Bamberg-
507 AM EDT Fri Jun 15 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.

Scattered thunderstorms will develop this afternoon and evening
across the Midlands and Central Savannah River Area. A few strong
storms are possible across the eastern Midlands and southern Central
Savannah River Area with the the main concerns being strong outflow
winds and hail.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Thunderstorms will be possible each day mainly during the afternoon
and evening hours. A few storms could contain strong wind and
locally heavy rain.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service Columbia SC
514 PM EDT FRI JUN 15 2018

SCZ035-036-041-152145-
Orangeburg SC-Barnwell SC-Bamberg SC-
514 PM EDT FRI JUN 15 2018

...Strong Thunderstorms Will Impact Portions of west central
Orangeburg...northeastern Barnwell and northwestern Bamberg Counties
Until 545 PM EDT....

At 513 PM EDT...National Weather Service doppler radar indicated a
strong thunderstorm 11 miles north of Blackville, or 16 miles
northwest of Denmark, moving southeast at 10 mph.

  HAZARD...gusty winds 40 to 50 mph and pea sized hail.

  IMPACT...expect minor damage to tree limbs and blowing around of
           light, unsecured objects. Minor hail damage to plants,
           trees and crops is possible. Damage to windshields is
           unlikely.

Some locations in the path of this storm include...
Blackville, Springfield, Neeses, Norway and Livingston.

LAT...LON 3350 8136 3363 8121 3346 8100 3330 8126
TIME...MOT...LOC 2113Z 323DEG 10KT 3353 8127

fwa