Alert archive / South Dakota / Severe Thunderstorm Watches in 2020
Severe Thunderstorm Watch 341
The Storm Prediction Center issued this severe thunderstorm watch at Jul 7, 2020, 8:17 PM CDT for 7 counties in South Dakota. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 7, 2020, 8:17 PM CDT (01:17 UTC)
- Expired
- Jul 8, 2020, 1:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Campbell County, SD, Corson County, SD, Dewey County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Walworth County, SD
The radar
The Bismarck radar (KBIS), 156 km from the middle of the area, began a volume at 01:20 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
- 10%
- One or more EF2 to EF5 tornadoes
- 5%
- 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
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 7, 10:48 PM CDT | Severe Thunderstorm Warning | ABR | Hughes, Stanley, Sully | 42 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
Bismarck Municip, ND (KBIS), launched 00:00Z, 1.3 hours before the alert went out and 156 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
- 972 J/kg
- Mixed-layer CIN
- -223 J/kg
- Mixed-layer LCL
- 1688 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 49 m²/s²
- 0-3 km storm-relative helicity
- 178 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.4
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 7, 7:13 PM CDT | Severe Thunderstorm Watch | SPC | Bennett, Butte, Haakon, Harding, Jackson, Lawrence and 5 more | 5 hr |
| Jul 7, 8:02 PM CDT | Mesoscale Discussion | SPC | Dewey, Haakon, Jackson, Jones, Meade, Pennington and 3 more | 118 min |
| Jul 8, 4:10 AM CDT | Mesoscale Discussion | SPC | Brown, Codington, Day, Grant, Marshall, Roberts | 2 hr |
| Jul 8, 3:03 PM CDT | Mesoscale Discussion | SPC | Codington, Grant, Roberts | 117 min |
| Jul 8, 3:39 PM CDT | Mesoscale Discussion | SPC | Aurora, Bon Homme, Charles Mix, Clay, Davison, Douglas and 10 more | 3 hr |
| Jul 8, 4:15 PM CDT | Severe Thunderstorm Watch | SPC | Clark, Codington, Deuel, Grant, Hamlin, Roberts | 8 hr |
| Jul 8, 5:10 PM CDT | Severe Thunderstorm Watch | SPC | Aurora, Beadle, Bon Homme, Brookings, Brule, Charles Mix and 14 more | 7 hr |
| Jul 8, 6:17 PM CDT | Mesoscale Discussion | SPC | Codington, Deuel, Grant, Hamlin | 118 min |
Nearby
Severe Thunderstorm Watches in South Dakota, 2020Every severe thunderstorm watch 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.