Alert archive / South Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 34, NWS Wilmington, NC

July 18, 2021Florence County, Williamsburg County, South Carolina

NWS Wilmington, NC issued this severe thunderstorm warning at Jul 18, 2021, 3:58 PM EDT for Florence County, Williamsburg County, South Carolina. It was in force for 32 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 18, 2021, 3:58 PM EDT (19:58 UTC)
Expired
Jul 18, 2021, 4:30 PM EDT
In force
32 min
Issued by
NWS Wilmington, NC
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Florence County, SC, Williamsburg County, SC

The radar

The Columbia radar (KCAE), 115 km from the middle of the area, began a volume at 19:58 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.

What was reported inside it

TimeReportWhereRemark
Jul 18, 4:05 PM EDTTSTM WND DMG4 Ese Olanta, SCLARGE PINE LIMBS BLOWN DOWN DURING THUNDERSTORM

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 8.0 hours before the alert went out and 91 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-pSkew-T log-p diagram, Charleston AFB, SC at 12:00Z on 2021-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 962 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Charleston AFB, SC at 12:00Z on 2021-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
962 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
983 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

094 
WUUS52 KILM 181958
SVRILM
SCC041-089-182030-
/O.NEW.KILM.SV.W.0034.210718T1958Z-210718T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Wilmington NC
358 PM EDT Sun Jul 18 2021

The National Weather Service in Wilmington has issued a

* Severe Thunderstorm Warning for...
  Southern Florence County in northeastern South Carolina...
  Williamsburg County in northeastern South Carolina...

* Until 430 PM EDT.

* At 358 PM EDT, severe thunderstorms were located along a line
  extending from near Woods Bay State Park to Salters, moving
  northeast at 35 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Minor hail damage to vehicles is possible. Expect wind 
           damage to trees and power lines.

* Locations impacted include...
  Lake City, Kingstree, Trio, Salters, Effingham, Cades, Gourdin,
  Earle, Hebron, Friendfield, Claussen, New Hope, Evergreen, Hyman,
  Scranton, Coward, Olanta, Lane, Greeleyville and Central
  Crossroads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3364 8002 3372 7998 3377 8000 3382 7991
      3388 7988 3388 7994 3395 7997 3399 7989
      3401 7993 3417 7960 3347 7961 3341 7985
      3343 7988 3344 7987 3350 7996 3350 8004
TIME...MOT...LOC 1958Z 233DEG 29KT 3394 7990 3359 7988 

HAIL...1.00IN
WIND...60MPH
 
$$

TRA
3 follow-up statements
028 
WWUS52 KILM 182011
SVSILM

Severe Weather Statement
National Weather Service Wilmington NC
411 PM EDT Sun Jul 18 2021

SCC041-089-182030-
/O.CON.KILM.SV.W.0034.000000T0000Z-210718T2030Z/
Florence SC-Williamsburg SC-
411 PM EDT Sun Jul 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR SOUTHERN FLORENCE AND WILLIAMSBURG COUNTIES...

At 410 PM EDT, severe thunderstorms were located along a line
extending from near Lake City to near Trio, moving northeast at 35
mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor hail damage to vehicles is possible. Expect wind 
         damage to trees and power lines.

Locations impacted include...
Lake City, Kingstree, Trio, Salters, Effingham, Cades, Gourdin,
Earle, Hebron, Friendfield, Claussen, New Hope, Evergreen, Hyman,
Scranton, Coward, Olanta, Lane, Central Crossroads and Lake City
Community Hospital.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3382 7991 3388 7988 3388 7994 3395 7997
      3399 7989 3401 7993 3417 7960 3347 7961
      3341 7985 3343 7988 3344 7987 3350 7996
TIME...MOT...LOC 2010Z 243DEG 30KT 3393 7979 3357 7971 

HAIL...1.00IN
WIND...60MPH
 
$$

TRA
072 
WWUS52 KILM 182021
SVSILM

Severe Weather Statement
National Weather Service Wilmington NC
421 PM EDT Sun Jul 18 2021

SCC041-089-182030-
/O.CON.KILM.SV.W.0034.000000T0000Z-210718T2030Z/
Florence SC-Williamsburg SC-
421 PM EDT Sun Jul 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR SOUTHERN FLORENCE AND NORTH CENTRAL WILLIAMSBURG COUNTIES...

At 421 PM EDT, severe thunderstorms were located along a line
extending from near Lake City to 6 miles west of Indiantown, moving
northeast at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect wind damage to trees and power lines.

Locations impacted include...
Lake City, Kingstree, Cades, Friendfield, Scranton, Coward, Lake City
Community Hospital and Williamsburg Regional Hospital.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3383 7988 3390 7988 3397 7989 3399 7989
      3401 7993 3402 7961 3359 7961 3357 7979
TIME...MOT...LOC 2021Z 233DEG 30KT 3388 7969 3370 7967 

HAIL...<.75IN
WIND...60MPH
 
$$

TRA
049 
WWUS52 KILM 182026
SVSILM

Severe Weather Statement
National Weather Service Wilmington NC
426 PM EDT Sun Jul 18 2021

SCC041-089-182035-
/O.EXP.KILM.SV.W.0034.000000T0000Z-210718T2030Z/
Florence SC-Williamsburg SC-
426 PM EDT Sun Jul 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN FLORENCE AND NORTH 
CENTRAL WILLIAMSBURG COUNTIES WILL EXPIRE AT 430 PM EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

LAT...LON 3383 7988 3390 7988 3397 7989 3399 7989
      3401 7993 3402 7961 3359 7961 3357 7979
TIME...MOT...LOC 2025Z 233DEG 33KT 3391 7963 3373 7961 

$$

TRA

The office that day

Everything else NWS Wilmington, NC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 18, 3:05 PM EDTSpecial Weather StatementILMHorry55 min
Jul 18, 3:24 PM EDTSpecial Weather StatementILMWilliamsburg66 min
Jul 18, 3:28 PM EDTSpecial Weather StatementILMHorry17 min
Jul 18, 4:30 PM EDTSpecial Weather StatementILMFlorence, Marion30 min
Jul 18, 4:47 PM EDTSpecial Weather StatementILMDarlington, Dillon, Marlboro28 min
Jul 18, 4:56 PM EDTSevere Thunderstorm WarningILMDillon, Florence, Horry, Marion34 min
Jul 18, 5:14 PM EDTSpecial Weather StatementILMDarlington31 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2021Every severe thunderstorm warning in 2021

Sources

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