Alert archive / South Dakota / Tornado Watches in 2010
Tornado Watch 484
The Storm Prediction Center issued this tornado watch at Jul 17, 2010, 4:37 PM CDT for 8 counties in Minnesota; 12 counties in Nebraska; 24 counties in South Dakota. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 17, 2010, 4:37 PM CDT (21:37 UTC)
- Expired
- Jul 17, 2010, 9:15 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 4 in
- Strongest gust expected
- 80 kt
All 44 counties
Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Antelope County, NE, Boyd County, NE, Brown County, NE, Cedar County, NE, Dakota County, NE, Dixon County, NE, Holt County, NE, Keya Paha County, NE, Knox County, NE, Pierce County, NE, Rock County, NE, Wayne County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Brule County, SD, Charles Mix County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Sioux Falls radar (KFSD), 92 km from the middle of the area, began a volume at 21:37 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
- 40%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 80%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 90%
- Six or more combined severe hail and wind reports
- 95%
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 |
|---|---|---|---|---|
| Jul 17, 5:49 PM CDT | Severe Thunderstorm Warning | LBF | Blaine, Brown | 41 min |
| Jul 17, 5:50 PM CDT | Severe Thunderstorm Warning | FSD | Gregory | 16 min |
| Jul 17, 5:52 PM CDT | Severe Thunderstorm Warning | LBF | Boyd, Holt, Keya Paha, Rock | 53 min |
| Jul 17, 6:23 PM CDT | Severe Thunderstorm Warning | FSD | Brookings, Kingsbury | 67 min |
| Jul 17, 6:31 PM CDT | Severe Thunderstorm Warning | LBF | Blaine, Brown | 44 min |
| Jul 17, 7:25 PM CDT | Severe Thunderstorm Warning | LBF | Holt | 50 min |
| Jul 17, 7:28 PM CDT | Severe Thunderstorm Warning | FSD | Brookings, Kingsbury | 47 min |
| Jul 17, 7:32 PM CDT | Tornado Warning | LBF | Holt | 28 min |
| Jul 17, 7:40 PM CDT | Severe Thunderstorm Warning | FSD | Brookings, Kingsbury, Lake, Moody | 35 min |
| Jul 17, 7:54 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Pipestone | 36 min |
| Jul 17, 7:57 PM CDT | Flash Flood Warning | FSD | Brookings | 3 hr |
| Jul 17, 7:59 PM CDT | Tornado Warning | LBF | Holt | 46 min |
| Jul 17, 8:11 PM CDT | Severe Thunderstorm Warning | LBF | Holt | 39 min |
| Jul 17, 8:27 PM CDT | Flash Flood Warning | FSD | Lincoln, Lyon, Murray, Pipestone | 3 hr |
| Jul 17, 8:32 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Pipestone | 43 min |
| Jul 17, 9:00 PM CDT | Severe Thunderstorm Warning | FSD | Cottonwood, Murray | 45 min |
| Jul 17, 9:07 PM CDT | Severe Thunderstorm Warning | FSD | Nobles, Pipestone, Rock | 23 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, 9.6 hours before the alert went out and 147 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
- 1448 J/kg
- Mixed-layer CIN
- -232 J/kg
- Mixed-layer LCL
- 1674 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 237 m²/s²
- 0-3 km storm-relative helicity
- 356 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 15.6
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 16, 7:28 PM CDT | Mesoscale Discussion | SPC | Faribault, Fillmore, Freeborn, Mower, Steele | 92 min |
| Jul 17, 11:58 AM CDT | Mesoscale Discussion | SPC | Anoka, Benton, Big Stone, Carver, Chippewa, Chisago and 29 more | 92 min |
| Jul 17, 12:28 PM CDT | Tornado Watch | SPC | Aitkin, Anoka, Benton, Big Stone, Brown, Carver and 39 more | 11 hr |
| Jul 17, 4:05 PM CDT | Mesoscale Discussion | SPC | Pipestone, Rock | 55 min |
| Jul 17, 5:56 PM CDT | Mesoscale Discussion | SPC | Anoka, Benton, Big Stone, Blue Earth, Brown, Carver and 53 more | 94 min |
| Jul 17, 12:02 AM CDT | Mesoscale Discussion | SPC | Adams, Buffalo, Dawson, Franklin, Frontier, Furnas and 6 more | 88 min |
| Jul 17, 5:56 PM CDT | Mesoscale Discussion | SPC | Blaine, Buffalo, Chase, Custer, Dawson, Dundy and 17 more | 64 min |
| Jul 17, 6:13 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Blaine, Buffalo, Chase, Clay, Custer and 31 more | 7 hr |
| Jul 17, 2:33 PM CDT | Mesoscale Discussion | SPC | Brown, Faulk | 87 min |
Nearby
Tornado Watches in South Dakota, 2010Tornado Watches in Nebraska, 2010Tornado Watches in Minnesota, 2010Every tornado watch in 2010
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.