Alert archive / South Dakota / Severe Thunderstorm Watches in 2008
Severe Thunderstorm Watch 906
The Storm Prediction Center issued this severe thunderstorm watch at Sep 22, 2008, 4:57 PM MDT for 11 counties in Nebraska; 25 counties in South Dakota. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 22, 2008, 4:57 PM MDT (22:57 UTC)
- Expired
- Sep 23, 2008, 12:00 AM MDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 36 counties
Arthur County, NE, Cherry County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Logan County, NE, McPherson County, NE, Sheridan County, NE, Thomas County, NE, Bennett County, SD, Brown 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, Pennington County, SD, Potter County, SD, Spink County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD, Ziebach County, SD
The radar
The North Platte radar (KLNX), 146 km from the middle of the area, began a volume at 22:57 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
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 22, 5:30 PM MDT | Severe Thunderstorm Warning | LBF | Deuel, Garden | 45 min |
| Sep 22, 6:06 PM MDT | Severe Thunderstorm Warning | LBF | Garden | 39 min |
| Sep 22, 6:12 PM MDT | Severe Thunderstorm Warning | LBF | Sheridan | 48 min |
| Sep 22, 6:37 PM MDT | Severe Thunderstorm Warning | UNR | Bennett | 53 min |
| Sep 22, 6:53 PM MDT | Severe Thunderstorm Warning | UNR | Jackson | 67 min |
| Sep 22, 7:33 PM MDT | Severe Thunderstorm Warning | UNR | Haakon | 57 min |
| Sep 22, 7:43 PM MDT | Severe Thunderstorm Warning | LBF | Cherry, Grant | 47 min |
| Sep 22, 7:52 PM MDT | Severe Thunderstorm Warning | UNR | Haakon, Jackson, Mellette | 53 min |
| Sep 22, 8:11 PM MDT | Severe Thunderstorm Warning | ABR | Jones, Stanley | 49 min |
| Sep 22, 9:21 PM MDT | Severe Thunderstorm Warning | ABR | Dewey, Faulk, Hughes, Hyde, Potter, Sully | 39 min |
| Sep 22, 9:55 PM MDT | Severe Thunderstorm Warning | ABR | Edmunds, Faulk, Hyde, Potter, Walworth | 50 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
Rapid City, SD (KUNR), launched 12:00Z, 11.0 hours before the alert went out and 155 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2168 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 39 m²/s²
- 0-3 km storm-relative helicity
- 83 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 22, 4:21 PM MDT | Mesoscale Discussion | SPC | Box Butte, Dawes, Morrill, Scotts Bluff, Sheridan, Sioux | 84 min |
| Sep 22, 4:10 PM MDT | Mesoscale Discussion | SPC | Campbell, McPherson | 65 min |
Nearby
Severe Thunderstorm Watches in South Dakota, 2008Severe Thunderstorm Watches in Nebraska, 2008Every severe thunderstorm watch in 2008
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.