Alert archive / South Dakota / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 440
The Storm Prediction Center issued this severe thunderstorm watch at Jun 30, 2012, 4:57 PM CDT for 6 counties in North Dakota; 21 counties in South Dakota. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 30, 2012, 4:57 PM CDT (21:57 UTC)
- Expired
- Jun 30, 2012, 10:14 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 27 counties
Burleigh County, ND, Emmons County, ND, Kidder County, ND, Logan County, ND, McIntosh County, ND, Sioux County, ND, Bennett County, SD, Campbell County, SD, Corson County, SD, Custer County, SD, Dewey County, SD, Edmunds County, SD, Fall River County, SD, Haakon County, SD, Hughes County, SD, Jackson County, SD, Jones County, SD, McPherson County, SD, Meade County, SD, Mellette County, SD, Pennington County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Walworth County, SD, Ziebach County, SD
The radar
The Bismarck radar (KBIS), 155 km from the middle of the area, began a volume at 21:57 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 30, 5:15 PM CDT | Severe Thunderstorm Warning | UNR | Ziebach | 60 min |
| Jun 30, 5:34 PM CDT | Severe Thunderstorm Warning | BIS | Sioux | 39 min |
| Jun 30, 5:43 PM CDT | Severe Thunderstorm Warning | BIS | Emmons, Morton, Sioux | 48 min |
| Jun 30, 6:00 PM CDT | Severe Thunderstorm Warning | BIS | Emmons, Logan | 30 min |
| Jun 30, 6:01 PM CDT | Severe Thunderstorm Warning | UNR | Meade, Perkins, Ziebach | 59 min |
| Jun 30, 6:41 PM CDT | Severe Thunderstorm Warning | UNR | Haakon, Meade, Ziebach | 64 min |
| Jun 30, 6:50 PM CDT | Severe Thunderstorm Warning | UNR | Meade, Pennington | 55 min |
| Jun 30, 7:09 PM CDT | Severe Thunderstorm Warning | UNR | Haakon, Meade, Pennington | 66 min |
| Jun 30, 7:20 PM CDT | Severe Thunderstorm Warning | BIS | Kidder, Stutsman | 40 min |
| Jun 30, 7:24 PM CDT | Severe Thunderstorm Warning | BIS | Kidder, Stutsman, Wells | 66 min |
| Jun 30, 7:54 PM CDT | Severe Thunderstorm Warning | UNR | Pennington | 66 min |
| Jun 30, 7:58 PM CDT | Severe Thunderstorm Warning | BIS | Kidder, Stutsman | 62 min |
| Jun 30, 8:07 PM CDT | Severe Thunderstorm Warning | UNR | Haakon, Jackson, Pennington | 53 min |
| Jun 30, 8:47 PM CDT | Severe Thunderstorm Warning | UNR | Bennett, Jackson, Pennington | 37 min |
| Jun 30, 8:56 PM CDT | Severe Thunderstorm Warning | UNR | Haakon, Jackson | 26 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 12:00Z, 10.0 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
- 269 J/kg
- Mixed-layer CIN
- -371 J/kg
- Mixed-layer LCL
- 1200 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 159 m²/s²
- 0-3 km storm-relative helicity
- 419 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 17.9
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 30, 3:48 AM CDT | Mesoscale Discussion | SPC | McHenry, McLean, Mountrail, Sheridan, Ward, Wells | 87 min |
| Jun 30, 3:53 PM CDT | Mesoscale Discussion | SPC | Sioux | 97 min |
Nearby
Severe Thunderstorm Watches in South Dakota, 2012Severe Thunderstorm Watches in North Dakota, 2012Every severe thunderstorm watch in 2012
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.