Alert archive / South Dakota / Severe Thunderstorm Watches in 2016
Severe Thunderstorm Watch 487
The Storm Prediction Center issued this severe thunderstorm watch at Sep 23, 2016, 2:21 PM MDT for 5 counties in Nebraska; 13 counties in South Dakota; 9 counties in Wyoming. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 23, 2016, 2:21 PM MDT (20:21 UTC)
- Expired
- Sep 23, 2016, 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 27 counties
Banner County, NE, Box Butte County, NE, Dawes County, NE, Scotts Bluff County, NE, Sioux County, NE, Bennett County, SD, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD, Albany County, WY, Campbell County, WY, Converse County, WY, Crook County, WY, Goshen County, WY, Laramie County, WY, Niobrara County, WY, Platte County, WY, Weston County, WY
The radar
The Rapid City radar (KUDX), 191 km from the middle of the area, began a volume at 20:21 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
- 50%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
13 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 23, 3:43 PM MDT | Severe Thunderstorm Warning | CYS | Box Butte, Dawes, Sioux | 47 min |
| Sep 23, 4:08 PM MDT | Severe Thunderstorm Warning | CYS | Goshen, Niobrara, Platte | 52 min |
| Sep 23, 4:20 PM MDT | Severe Thunderstorm Warning | CYS | Dawes | 38 min |
| Sep 23, 4:51 PM MDT | Severe Thunderstorm Warning | UNR | Fall River, Oglala Lakota | 39 min |
| Sep 23, 5:01 PM MDT | Severe Thunderstorm Warning | CYS | Dawes, Sioux | 44 min |
| Sep 23, 5:14 PM MDT | Severe Thunderstorm Warning | UNR | Custer, Fall River | 35 min |
| Sep 23, 5:17 PM MDT | Tornado Warning | CYS | Sioux | 28 min |
| Sep 23, 5:36 PM MDT | Severe Thunderstorm Warning | UNR | Custer, Fall River | 39 min |
| Sep 23, 5:53 PM MDT | Severe Thunderstorm Warning | UNR | Custer, Fall River | 52 min |
| Sep 23, 6:36 PM MDT | Severe Thunderstorm Warning | UNR | Custer, Pennington | 39 min |
| Sep 23, 7:02 PM MDT | Severe Thunderstorm Warning | UNR | Oglala Lakota, Pennington | 43 min |
| Sep 23, 7:09 PM MDT | Severe Thunderstorm Warning | UNR | Meade, Pennington | 51 min |
| Sep 23, 7:37 PM MDT | Severe Thunderstorm Warning | UNR | Pennington | 38 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 (KRAP), launched 12:00Z, 8.4 hours before the alert went out and 184 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
- 3 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 468 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 133 m²/s²
- 0-3 km storm-relative helicity
- 149 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 23, 1:23 PM MDT | Mesoscale Discussion | SPC | Banner, Box Butte, Dawes, Kimball, Morrill, Scotts Bluff and 1 more | 67 min |
| Sep 23, 5:35 PM MDT | Mesoscale Discussion | SPC | Banner, Box Butte, Cheyenne, Dawes, Kimball, Morrill and 3 more | 85 min |
Nearby
Severe Thunderstorm Watches in South Dakota, 2016Severe Thunderstorm Watches in Wyoming, 2016Severe Thunderstorm Watches in Nebraska, 2016Every severe thunderstorm watch in 2016
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.