Alert archive / South Carolina / Heat Advisories in 2020

Heat Advisory 3, NWS Columbia, SC

July 21, 2020Lancaster County, South Carolina

NWS Columbia, SC issued this heat advisory at Jul 21, 2020, 7:45 PM EDT for Lancaster County, South Carolina. It took effect at Jul 22, 2020, 12:00 PM EDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: Jul 21, 2020, 7:45 PM EDT (23:45 UTC)
In effect from: Jul 22, 2020, 12:00 PM EDT
Expired: Jul 22, 2020, 8:00 PM EDT
In force: 8 hr
Issued by: NWS Columbia, SC

County Lancaster County, SC

The radar

The Columbia radar (KCAE), 90 km from the middle of the area, began a volume at 23:47 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 11.8 hours before the alert went out and 209 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 985 J/kg
Mixed-layer CIN: -82 J/kg
Mixed-layer LCL: 1101 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: -9 m²/s²
0-3 km storm-relative helicity: 12 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Columbia, SC wrote its last area forecast discussion before this heat advisory went out at Jul 21, 7:12 PM EDT, 33 minutes earlier.

Area forecast discussion, Jul 21, 7:12 PM EDT, 33 minutes before

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Hazardous weather outlook, Jul 21, 4:08 AM EDT, 15 hours 37 minutes before

Hazardous Weather Outlook
National Weather Service Columbia SC
408 AM EDT Tue Jul 21 2020

GAZ040-063>065-077-SCZ016-018-020>022-025>031-035>038-041-116-220815-
Lincoln-McDuffie-Columbia-Richmond-Burke-Chesterfield-McCormick-
Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington-Richland-Lee-
Aiken-Sumter-Barnwell-Orangeburg-Calhoun-Clarendon-Bamberg-
Southern Lancaster-
408 AM EDT Tue Jul 21 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.

SCZ115-220815-
Northern Lancaster-
408 AM EDT Tue Jul 21 2020

...HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 8 PM EDT THIS
EVENING...

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

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.

.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.

In the hours before

Special weather statement, Jul 21, 2:17 PM EDT, 5 hours 28 minutes before

Special Weather Statement
National Weather Service Columbia SC
217 PM EDT Tue Jul 21 2020

SCZ016-022-116-211900-
Chesterfield SC-Southern Lancaster SC-Kershaw SC-
217 PM EDT Tue Jul 21 2020

...Strong Thunderstorms Will Impact Portions of Chesterfield...
Southern Lancaster and Kershaw Counties Until 300 PM EDT....

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

At 216 PM EDT...National Weather Service doppler radar indicated a
strong thunderstorm near Carolina Sandhills Wildlife Refuge, or 17
miles west of Cheraw. This storm was nearly stationary. Additional
strong thunderstorms may develop soon in portions of Lancaster and
Kershaw counties.

  HAZARD...gusty winds 40 to 50 mph and localized minor flooding.

  IMPACT...expect minor damage to tree limbs and blowing around of
           light, unsecured objects. Localized minor flooding of low
           lying and poor drainage areas is also possible.

Some locations in the path of this storm include...
Camden, Cheraw, Lake Wateree Dam, Pageland, Kershaw, Chesterfield,
Heath Springs, Lugoff, Westville, Cheraw State Park, Northeastern
Technical College, Cassatt, Liberty Hill, Cheraw Municipal Airport,
Elgin, Carolina Sandhills Wildlife Refuge, Mt Pisgah, Goodale State
Park, Mcbee and Jefferson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters on Lake Wateree 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.

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

&&

This includes Interstate 20 in South Carolina between mile markers 85
and 105.

LAT...LON 3460 7981 3449 7988 3449 8005 3434 8033
      3434 8036 3430 8036 3428 8044 3425 8042
      3418 8046 3410 8058 3411 8062 3407 8072
      3418 8087 3438 8077 3448 8089 3482 8039
      3481 7994 3468 7986 3465 7980 3461 7978
TIME...MOT...LOC 1816Z 250DEG 3KT 3461 8018

CJR

Special weather statement, Jul 21, 2:45 PM EDT, 5 hours before

Special Weather Statement
National Weather Service Columbia SC
245 PM EDT Tue Jul 21 2020

SCZ022-027-028-037-211945-
Lexington SC-Calhoun SC-Richland SC-Kershaw SC-
245 PM EDT Tue Jul 21 2020

...Strong Thunderstorms Will Impact Portions of Lexington...
northwestern Calhoun...Richland and southwestern Kershaw Counties
Until 345 PM EDT....

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

At 245 PM EDT...National Weather Service doppler radar indicated a
strong thunderstorm over Forest Acres. This storm was nearly
stationary.

  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...
Columbia, Lexington, West Columbia, Cayce, Irmo, Forest Acres,
Batesburg-Leesville, Springdale, St. Andrews, Dentsville, Oak Grove,
McEntire Air Base, Highway 6 at Lake Murray Dam, Red Bank, South
Congaree, Pine Ridge, Gaston, Arcadia Lakes, Lugoff and Columbia
International University.

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 the following highways...
 Interstate 126 between mile markers 0 and 3.
 Interstate 20 in South Carolina between mile markers 37 and 94.
 Interstate 26 between mile markers 93 and 131.
 Interstate 77 between mile markers 0 and 29.

LAT...LON 3409 8064 3404 8060 3400 8065 3395 8062
      3377 8087 3369 8103 3366 8118 3373 8141
      3388 8157 3407 8148 3407 8139 3411 8141
      3421 8123 3418 8118 3422 8118 3427 8083
      3436 8078 3442 8084 3442 8083 3412 8055
TIME...MOT...LOC 1845Z 059DEG 1KT 3404 8098

CJR

Local storm report, Jul 21, 2:50 PM EDT, 4 hours 55 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE COLUMBIA SC
250 PM EDT TUE JUL 21 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0238 PM     HAIL             1 S ARCADIA LAKES       34.04N 80.96W
07/21/2020  E0.25 INCH       RICHLAND           SC   PUBLIC

            PUBLIC REPORT PEA SIZE HAIL AND 40 MPH
            WINDS.

&&

AWP

Special weather statement, Jul 21, 3:04 PM EDT, 4 hours 41 minutes before

Special Weather Statement
National Weather Service Columbia SC
304 PM EDT Tue Jul 21 2020

GAZ064-065-SCZ018-025>027-030-212000-
Richmond GA-Columbia GA-Lexington SC-Aiken SC-McCormick SC-Saluda SC-
Edgefield SC-
304 PM EDT Tue Jul 21 2020

...Strong Thunderstorms Will Impact Portions of northeastern
Richmond...east central Columbia...southwestern Lexington...Aiken...
southeastern McCormick...southeastern Saluda and Edgefield Counties
Until 400 PM EDT....

...Boaters on Lake Strom Thurmond Should Seek Safe Harbor...

At 304 PM EDT...National Weather Service doppler radar indicated a
strong thunderstorm 7 miles south of Batesburg-Leesville. This storm
was nearly stationary. Other strong storms will develop in the areas
listed.

  HAZARD...strong winds 45 to 55 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...
Aiken, North Augusta, Lexington, Grovetown, Evans,
Batesburg-Leesville, Augusta, Clearwater, Martinez, Aiken Mall, Red
Bank, Belvedere, Edgefield, Johnston, Ridge Spring, Glendale,
Edgefield County Airport, Summerville, Augusta Mall and Daniel Field.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters on Lake Strom Thurmond 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 the following highways...
 Interstate 20 in Georgia between mile markers 185 and 201.
 Interstate 20 in South Carolina between mile markers 0 and 55.
 Interstate 520 in Georgia between mile markers 1 and 8, and between
mile markers 10 and 15.
 Interstate 520 in South Carolina between mile markers 16 and 23.

LAT...LON 3406 8125 3379 8115 3353 8141 3339 8206
      3348 8230 3362 8217 3377 8221 3400 8161
      3406 8145
TIME...MOT...LOC 1904Z 056DEG 2KT 3380 8150

CJR

Special weather statement, Jul 21, 3:32 PM EDT, 4 hours 13 minutes before

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Special weather statement, Jul 21, 4:28 PM EDT, 3 hours 17 minutes before

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The office that day

Everything else NWS Columbia, SC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 10:02 PM EDT	Heat Advisory	CAE	Lancaster	22 hr
Jul 21, 2:17 PM EDT	Special Weather Statement	CAE	Chesterfield, Kershaw	43 min
Jul 21, 2:26 PM EDT	Severe Thunderstorm Warning	CAE	Kershaw, Lancaster	49 min
Jul 21, 2:45 PM EDT	Special Weather Statement	CAE	Lexington, Richland	60 min
Jul 21, 2:51 PM EDT	Severe Thunderstorm Warning	CAE	McCormick	39 min
Jul 21, 3:04 PM EDT	Special Weather Statement	CAE	Aiken, Edgefield, Lexington	56 min
Jul 21, 3:18 PM EDT	Severe Thunderstorm Warning	CAE	Aiken, Edgefield, Lexington, Saluda	40 min
Jul 21, 3:32 PM EDT	Special Weather Statement	CAE	McCormick	28 min
Jul 21, 4:28 PM EDT	Special Weather Statement	CAE	Newberry	32 min
Jul 21, 2:10 PM EDT	Special Weather Statement	CAE	Columbia, McDuffie, Richmond	35 min

Nearby

Heat Advisories in South Carolina, 2020 Every heat advisory in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.