Alert archive / South Dakota / Severe Thunderstorm Watches in 2007
Severe Thunderstorm Watch 685
The Storm Prediction Center issued this severe thunderstorm watch at Sep 23, 2007, 2:23 PM MDT for 15 counties in Nebraska; 14 counties in North Dakota; 24 counties in South Dakota. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 23, 2007, 2:23 PM MDT (20:23 UTC)
- Expired
- Sep 23, 2007, 10:00 PM MDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 53 counties
Burleigh County, ND, Dickey County, ND, Emmons County, ND, Foster County, ND, Grant County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Morton County, ND, Oliver County, ND, Sioux County, ND, Stutsman County, ND, Wells County, ND, Arthur County, NE, Blaine County, NE, Brown County, NE, Cherry County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Sheridan County, NE, Thomas County, NE, Bennett County, SD, Brown County, SD, Buffalo County, SD, Campbell County, SD, Corson County, SD, Dewey County, SD, Edmunds County, SD, Faulk County, SD, Haakon County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, McPherson County, SD, Mellette County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD, Ziebach County, SD
The radar
The Rapid City radar (KUDX), 175 km from the middle of the area, began a volume at 20:25 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
- 2%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 30%
- 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
- 90%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 23, 5:16 PM MDT | Severe Thunderstorm Warning | LBF | Arthur, Garden, Grant | 44 min |
| Sep 23, 6:20 PM MDT | Severe Thunderstorm Warning | UNR | Haakon, Ziebach | 55 min |
| Sep 23, 6:41 PM MDT | Severe Thunderstorm Warning | BIS | Logan, McIntosh | 53 min |
| Sep 23, 7:10 PM MDT | Severe Thunderstorm Warning | BIS | LaMoure, Stutsman | 65 min |
| Sep 23, 7:40 PM MDT | Severe Thunderstorm Warning | UNR | Bennett, Todd | 65 min |
| Sep 23, 7:47 PM MDT | Severe Thunderstorm Warning | UNR | Mellette | 33 min |
| Sep 23, 8:02 PM MDT | Severe Thunderstorm Warning | BIS | McIntosh | 28 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
Aberdeen, SD (KABR), launched 12:00Z, 8.4 hours before the alert went out and 192 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
- 396 J/kg
- Mixed-layer CIN
- -392 J/kg
- Mixed-layer LCL
- 1130 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 101 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 23, 1:51 PM MDT | Mesoscale Discussion | SPC | Arthur, Cherry, Cheyenne, Deuel, Garden, Grant and 3 more | 114 min |
| Sep 23, 5:29 PM MDT | Mesoscale Discussion | SPC | Cherry, Hooker, Keya Paha, McPherson, Thomas | 91 min |
| Sep 23, 5:45 PM MDT | Mesoscale Discussion | SPC | Barnes, Benson, Cass, Cavalier, Eddy, Foster and 11 more | 2 hr |
Nearby
Severe Thunderstorm Watches in South Dakota, 2007Severe Thunderstorm Watches in Nebraska, 2007Severe Thunderstorm Watches in North Dakota, 2007Every severe thunderstorm watch in 2007
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.