Alert archive / South Carolina / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 77
The Storm Prediction Center issued this severe thunderstorm watch at Mar 21, 2017, 8:35 PM EDT for 15 counties in Georgia; 21 counties in South Carolina. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 21, 2017, 8:35 PM EDT (00:35 UTC)
- Expired
- Mar 22, 2017, 2:00 AM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 36 counties
Burke County, GA, Butts County, GA, Columbia County, GA, Glascock County, GA, Hancock County, GA, Jasper County, GA, Jefferson County, GA, Jenkins County, GA, Lincoln County, GA, McDuffie County, GA, Putnam County, GA, Richmond County, GA, Screven County, GA, Warren County, GA, Washington County, GA, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Berkeley County, SC, Calhoun County, SC, Clarendon County, SC, Colleton County, SC, Dorchester County, SC, Edgefield County, SC, Fairfield County, SC, Hampton County, SC, Kershaw County, SC, Lee County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC
The radar
The Columbia radar (KCAE), 114 km from the middle of the area, began a volume at 00:39 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
17 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 21, 9:01 PM EDT | Severe Thunderstorm Warning | CAE | Fairfield, Newberry, Saluda | 44 min |
| Mar 21, 9:36 PM EDT | Severe Thunderstorm Warning | CAE | Fairfield, Lexington, Richland | 39 min |
| Mar 21, 9:45 PM EDT | Severe Thunderstorm Warning | FFC | Glascock, Greene, Hancock, Morgan, Oglethorpe, Putnam and 4 more | 45 min |
| Mar 21, 10:04 PM EDT | Severe Thunderstorm Warning | CAE | Kershaw, Lexington, Richland | 41 min |
| Mar 21, 10:05 PM EDT | Severe Thunderstorm Warning | CAE | Lincoln | 40 min |
| Mar 21, 10:08 PM EDT | Severe Thunderstorm Warning | CAE | Columbia, McDuffie, Richmond | 37 min |
| Mar 21, 10:31 PM EDT | Severe Thunderstorm Warning | CAE | Richmond | 59 min |
| Mar 21, 10:34 PM EDT | Severe Thunderstorm Warning | CAE | Calhoun, Clarendon, Richland, Sumter | 41 min |
| Mar 21, 10:45 PM EDT | Severe Thunderstorm Warning | CAE | Burke, Columbia, Richmond | 45 min |
| Mar 21, 10:51 PM EDT | Severe Thunderstorm Warning | CAE | Chesterfield, Kershaw, Lee, Sumter | 39 min |
| Mar 21, 10:58 PM EDT | Severe Thunderstorm Warning | CAE | Clarendon, Lee, Orangeburg, Sumter | 47 min |
| Mar 21, 11:15 PM EDT | Severe Thunderstorm Warning | CAE | Burke | 45 min |
| Mar 21, 11:28 PM EDT | Severe Thunderstorm Warning | CAE | Aiken, Lexington, Orangeburg | 32 min |
| Mar 21, 11:31 PM EDT | Severe Thunderstorm Warning | CHS | Jenkins, Screven | 59 min |
| Mar 21, 11:57 PM EDT | Severe Thunderstorm Warning | CHS | Effingham, Screven | 33 min |
| Mar 22, 12:41 AM EDT | Severe Thunderstorm Warning | CHS | Beaufort, Charleston, Colleton, Jasper | 34 min |
| Mar 22, 12:50 AM EDT | Severe Thunderstorm Warning | CHS | Beaufort, Berkeley, Charleston, Colleton, Dorchester | 44 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 0.6 hours before the alert went out and 211 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.
- Mixed-layer CAPE
- 377 J/kg
- Mixed-layer CIN
- -45 J/kg
- Mixed-layer LCL
- 2348 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 67 m²/s²
- 0-3 km storm-relative helicity
- 160 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 21, 11:18 PM EDT | Mesoscale Discussion | SPC | Burke, Jenkins, Richmond, Screven | 57 min |
Nearby
Severe Thunderstorm Watches in South Carolina, 2017Severe Thunderstorm Watches in Georgia, 2017Every severe thunderstorm watch in 2017
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.