Alert archive / South Dakota / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 283

June 21, 201612 counties in Iowa; 9 counties in Nebraska; 16 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jun 21, 2016, 10:21 PM CDT for 12 counties in Iowa; 9 counties in Nebraska; 16 counties in South Dakota. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jun 21, 2016, 10:21 PM CDT (03:21 UTC)
Expired: Jun 22, 2016, 5:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 37 counties

Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Ida County, IA, Lyon County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Boyd County, NE, Cedar County, NE, Dakota County, NE, Dixon County, NE, Holt County, NE, Keya Paha County, NE, Knox County, NE, Thurston County, NE, Wayne County, NE, Aurora County, SD, Bon Homme 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, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 73 km from the middle of the area, began a volume at 03:23 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: 40%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Jun 22, 1:41 AM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Clay	34 min
Jun 22, 2:15 AM CDT	Severe Thunderstorm Warning	FSD	Brule	32 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 00:00Z, 3.4 hours before the alert went out and 195 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2484 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 71 m²/s²
0-3 km storm-relative helicity: 267 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 21, 9:49 PM CDT	Mesoscale Discussion	SPC	Buena Vista, Cherokee, Clay, Crawford, Dickinson, Ida and 8 more	26 min
Jun 21, 10:28 PM CDT	Mesoscale Discussion	SPC	Appanoose, Benton, Black Hawk, Buchanan, Cedar, Davis and 22 more	2 hr
Jun 21, 11:18 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Black Hawk, Bremer, Buchanan, Butler, Calhoun and 34 more	6 hr
Jun 22, 2:31 AM CDT	Mesoscale Discussion	SPC	Benton, Black Hawk, Bremer, Buena Vista, Butler, Calhoun and 38 more	119 min
Jun 22, 4:00 AM CDT	Mesoscale Discussion	SPC	Des Moines	2 hr
Jun 22, 4:43 AM CDT	Mesoscale Discussion	SPC	Clay, Dickinson, Lyon, O'Brien, Osceola, Sioux	92 min
Jun 22, 3:38 PM CDT	Mesoscale Discussion	SPC	Buchanan, Cedar, Clayton, Clinton, Delaware, Dubuque and 4 more	97 min
Jun 22, 6:11 PM CDT	Tornado Watch	SPC	Benton, Buchanan, Cedar, Clinton, Delaware, Dubuque and 10 more	7 hr
Jun 21, 8:00 PM CDT	Mesoscale Discussion	SPC	Brule, Buffalo, Dewey, Haakon, Hand, Harding and 11 more	60 min
Jun 21, 8:35 PM CDT	Severe Thunderstorm Watch	SPC	Brown, Campbell, Corson, Edmunds, McPherson, Walworth	7 hr
Jun 21, 11:30 PM CDT	Mesoscale Discussion	SPC	Brown, Campbell, Edmunds, McPherson	60 min
Jun 22, 1:15 AM CDT	Mesoscale Discussion	SPC	Beadle, Brown, Campbell, Clark, Edmunds, Faulk and 8 more	2 hr

Nearby

Severe Thunderstorm Watches in South Dakota, 2016 Severe Thunderstorm Watches in Iowa, 2016 Severe Thunderstorm Watches in Nebraska, 2016 Every 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.