Alert archive / Minnesota / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 418

July 17, 201729 counties in Minnesota; 7 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 17, 2017, 3:21 PM CDT for 29 counties in Minnesota; 7 counties in Wisconsin. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jul 17, 2017, 3:21 PM CDT (20:21 UTC)
Expired: Jul 17, 2017, 10:18 PM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 36 counties

Aitkin County, MN, Becker County, MN, Benton County, MN, Big Stone County, MN, Carlton County, MN, Cass County, MN, Chisago County, MN, Cook County, MN, Crow Wing County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Isanti County, MN, Itasca County, MN, Kanabec County, MN, Lake County, MN, Mille Lacs County, MN, Morrison County, MN, Otter Tail County, MN, Pine County, MN, Pope County, MN, Saint Louis County, MN, Sherburne County, MN, Stearns County, MN, Stevens County, MN, Todd County, MN, Traverse County, MN, Wadena County, MN, Wilkin County, MN, Barron County, WI, Bayfield County, WI, Burnett County, WI, Douglas County, WI, Polk County, WI, Sawyer County, WI, Washburn County, WI

The radar

The Duluth radar (KDLH), 166 km from the middle of the area, began a volume at 20:22 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: 2%
Ten or more severe wind reports: 60%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 60%
One or more hailstones of 2 inches or more: 40%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 17, 3:26 PM CDT	Severe Thunderstorm Warning	FGF	Otter Tail, Wadena	64 min
Jul 17, 4:24 PM CDT	Severe Thunderstorm Warning	FGF	Grant, Otter Tail	66 min
Jul 17, 4:34 PM CDT	Severe Thunderstorm Warning	FGF	Grant, Otter Tail, Wilkin	56 min
Jul 17, 4:44 PM CDT	Severe Thunderstorm Warning	DLH	Cass	31 min
Jul 17, 4:50 PM CDT	Severe Thunderstorm Warning	MPX	Todd	40 min
Jul 17, 5:05 PM CDT	Severe Thunderstorm Warning	DLH	Cass, Crow Wing	40 min
Jul 17, 5:24 PM CDT	Severe Thunderstorm Warning	MPX	Douglas	66 min
Jul 17, 5:29 PM CDT	Severe Thunderstorm Warning	MPX	Morrison, Todd	61 min
Jul 17, 5:30 PM CDT	Severe Thunderstorm Warning	FGF	Grant, Otter Tail	39 min
Jul 17, 5:34 PM CDT	Severe Thunderstorm Warning	DLH	Crow Wing	41 min
Jul 17, 5:37 PM CDT	Tornado Warning	MPX	Morrison, Todd	38 min
Jul 17, 5:45 PM CDT	Tornado Warning	MPX	Douglas	45 min
Jul 17, 5:56 PM CDT	Severe Thunderstorm Warning	DLH	Itasca	49 min
Jul 17, 5:58 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Cass, Crow Wing	47 min
Jul 17, 6:01 PM CDT	Severe Thunderstorm Warning	DLH	Cass, Itasca	44 min
Jul 17, 6:01 PM CDT	Severe Thunderstorm Warning	MPX	Morrison	59 min
Jul 17, 6:09 PM CDT	Severe Thunderstorm Warning	DLH	Crow Wing	39 min
Jul 17, 6:19 PM CDT	Tornado Warning	MPX	Morrison	41 min
Jul 17, 6:27 PM CDT	Severe Thunderstorm Warning	MPX	Douglas, Todd	63 min
Jul 17, 6:28 PM CDT	Severe Thunderstorm Warning	ABR	Traverse	32 min
Jul 17, 6:40 PM CDT	Tornado Warning	MPX	Douglas, Stearns, Todd	35 min
Jul 17, 6:43 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Carlton, Pine, Saint Louis	62 min
Jul 17, 6:47 PM CDT	Severe Thunderstorm Warning	MPX	Benton, Kanabec, Mille Lacs, Morrison	58 min
Jul 17, 6:53 PM CDT	Severe Thunderstorm Warning	DLH	Saint Louis	37 min
Jul 17, 7:11 PM CDT	Tornado Warning	DLH	Saint Louis	34 min
Jul 17, 7:17 PM CDT	Severe Thunderstorm Warning	DLH	Carlton, Pine	43 min
Jul 17, 7:23 PM CDT	Severe Thunderstorm Warning	DLH	Saint Louis	37 min
Jul 17, 7:30 PM CDT	Severe Thunderstorm Warning	DLH	Saint Louis	30 min
Jul 17, 7:39 PM CDT	Severe Thunderstorm Warning	DLH	Pine	51 min
Jul 17, 7:48 PM CDT	Severe Thunderstorm Warning	MPX	Benton, Isanti, Mille Lacs, Sherburne	42 min
Jul 17, 7:56 PM CDT	Severe Thunderstorm Warning	DLH	Pine	49 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

Minneapolis, MN (KMPX), launched 12:00Z, 8.4 hours before the alert went out and 204 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: 1041 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 140 m²/s²
0-3 km storm-relative helicity: 214 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 17, 2:57 PM CDT	Mesoscale Discussion	SPC	Aitkin, Becker, Benton, Big Stone, Carlton, Cass and 22 more	63 min
Jul 17, 6:22 PM CDT	Mesoscale Discussion	SPC	Aitkin, Becker, Benton, Carlton, Cass, Crow Wing and 12 more	53 min
Jul 17, 6:41 PM CDT	Mesoscale Discussion	SPC	Aitkin, Becker, Benton, Carlton, Cass, Crow Wing and 12 more	2 hr

Nearby

Severe Thunderstorm Watches in Minnesota, 2017 Severe Thunderstorm Watches in Wisconsin, 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.