Alert archive / South Dakota / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 409

July 11, 201713 counties in Minnesota; 17 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jul 11, 2017, 6:52 PM CDT for 13 counties in Minnesota; 17 counties in South Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jul 11, 2017, 6:52 PM CDT (23:52 UTC)
Expired: Jul 12, 2017, 12:00 AM CDT
In force: 5 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 30 counties

Big Stone County, MN, Chippewa County, MN, Douglas County, MN, Lac qui Parle County, MN, Lincoln County, MN, Lyon County, MN, Pipestone County, MN, Pope County, MN, Rock County, MN, Stevens County, MN, Swift County, MN, Traverse County, MN, Yellow Medicine County, MN, Brookings County, SD, Clark County, SD, Codington County, SD, Davison County, SD, Day County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Hanson County, SD, Kingsbury County, SD, Lake County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Roberts County, SD, Sanborn County, SD

The radar

The Aberdeen radar (KABR), 123 km from the middle of the area, began a volume at 23:53 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: 30%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 30%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 60%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 11, 6:58 PM CDT	Severe Thunderstorm Warning	ABR	Big Stone, Traverse	47 min
Jul 11, 7:00 PM CDT	Severe Thunderstorm Warning	ABR	Codington, Deuel, Hamlin	45 min
Jul 11, 7:24 PM CDT	Severe Thunderstorm Warning	ABR	Codington, Deuel, Grant	51 min
Jul 11, 7:25 PM CDT	Severe Thunderstorm Warning	ABR	Deuel, Hamlin	50 min
Jul 11, 7:51 PM CDT	Severe Thunderstorm Warning	ABR	Codington, Deuel, Hamlin	39 min
Jul 11, 8:07 PM CDT	Severe Thunderstorm Warning	ABR	Big Stone, Traverse	68 min
Jul 11, 8:08 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Davison	37 min
Jul 11, 8:22 PM CDT	Severe Thunderstorm Warning	ABR	Codington, Deuel, Hamlin	27 min
Jul 11, 8:35 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Davison	40 min
Jul 11, 8:36 PM CDT	Severe Thunderstorm Warning	FSD	Hanson, McCook, Miner, Sanborn	24 min
Jul 11, 8:56 PM CDT	Severe Thunderstorm Warning	FSD	Brookings	34 min
Jul 11, 9:08 PM CDT	Severe Thunderstorm Warning	FSD	Davison, Hanson, Hutchinson	37 min
Jul 11, 9:19 PM CDT	Tornado Warning	FSD	Brookings	26 min
Jul 11, 9:25 PM CDT	Severe Thunderstorm Warning	FSD	Hanson, Hutchinson, McCook	35 min
Jul 11, 9:28 PM CDT	Tornado Warning	FSD	Brookings	32 min
Jul 11, 9:29 PM CDT	Severe Thunderstorm Warning	FSD	Brookings	31 min
Jul 11, 9:36 PM CDT	Severe Thunderstorm Warning	ABR	Deuel, Hamlin	24 min
Jul 11, 9:44 PM CDT	Severe Thunderstorm Warning	ABR	Codington, Deuel, Hamlin	46 min
Jul 11, 9:46 PM CDT	Severe Thunderstorm Warning	FSD	Brookings, Kingsbury	29 min
Jul 11, 9:49 PM CDT	Severe Thunderstorm Warning	ABR	Clark, Codington, Deuel, Hamlin	41 min
Jul 11, 9:57 PM CDT	Severe Thunderstorm Warning	FSD	Brookings, Kingsbury	33 min
Jul 11, 10:00 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln	30 min
Jul 11, 10:27 PM CDT	Severe Thunderstorm Warning	FSD	Brookings	33 min
Jul 11, 10:28 PM CDT	Severe Thunderstorm Warning	ABR	Codington, Hamlin	47 min
Jul 11, 10:29 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln	31 min
Jul 11, 10:48 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln	27 min
Jul 11, 11:10 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Pipestone	35 min
Jul 11, 11:14 PM CDT	Severe Thunderstorm Warning	MPX	Douglas	46 min
Jul 11, 11:27 PM CDT	Severe Thunderstorm Warning	MPX	Pope	33 min
Jul 11, 11:59 PM CDT	Severe Thunderstorm Warning	MPX	Douglas, Pope, Stearns, Todd	46 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, 11.9 hours before the alert went out and 110 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: 1893 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 62 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
Jul 11, 3:48 PM CDT	Mesoscale Discussion	SPC	Becker, Big Stone, Chippewa, Clay, Douglas, Grant and 16 more	87 min
Jul 11, 4:48 PM CDT	Tornado Watch	SPC	Becker, Clay, Clearwater, Grant, Hubbard, Kittson and 9 more	6 hr
Jul 11, 6:26 PM CDT	Mesoscale Discussion	SPC	Aurora, Beadle, Brookings, Clark, Codington, Davison and 12 more	2 hr

Nearby

Severe Thunderstorm Watches in South Dakota, 2017 Severe Thunderstorm Watches in Minnesota, 2017 Every severe thunderstorm watch in 2017

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.