Alert archive / Minnesota / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 488

September 19, 201736 counties in Minnesota

The Storm Prediction Center issued this severe thunderstorm watch at Sep 19, 2017, 10:36 PM CDT for 36 counties in Minnesota. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Sep 19, 2017, 10:36 PM CDT (03:36 UTC)
Expired
Sep 20, 2017, 3:00 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
65 kt
All 36 counties

Becker County, MN, Beltrami County, MN, Benton County, MN, Brown County, MN, Cass County, MN, Chippewa County, MN, Clearwater County, MN, Cottonwood County, MN, Crow Wing County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Lincoln County, MN, Lyon County, MN, Mahnomen County, MN, McLeod County, MN, Meeker County, MN, Morrison County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Otter Tail County, MN, Pipestone County, MN, Pope County, MN, Redwood County, MN, Renville County, MN, Rock County, MN, Sibley County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Wadena County, MN, Yellow Medicine County, MN

The radar

The Minneapolis radar (KMPX), 154 km from the middle of the area, began a volume at 03:37 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
20%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 19, 10:55 PM CDTSevere Thunderstorm WarningMPXLac qui Parle50 min
Sep 19, 11:08 PM CDTSevere Thunderstorm WarningFSDPipestone, Rock52 min
Sep 19, 11:24 PM CDTSevere Thunderstorm WarningMPXStevens, Swift36 min
Sep 19, 11:29 PM CDTSevere Thunderstorm WarningFSDNobles, Pipestone, Rock46 min
Sep 19, 11:46 PM CDTSevere Thunderstorm WarningFGFGrant, Otter Tail44 min
Sep 19, 11:47 PM CDTSevere Thunderstorm WarningFSDLincoln, Lyon, Murray, Nobles, Pipestone, Rock43 min
Sep 19, 11:50 PM CDTSevere Thunderstorm WarningMPXDouglas, Pope, Stevens55 min
Sep 20, 12:24 AM CDTSevere Thunderstorm WarningMPXSwift21 min
Sep 20, 12:42 AM CDTSevere Thunderstorm WarningMPXKandiyohi, Pope, Stearns, Todd33 min
Sep 20, 1:02 AM CDTSevere Thunderstorm WarningMPXKandiyohi, Meeker, Renville43 min
Sep 20, 1:11 AM CDTSevere Thunderstorm WarningMPXBenton, Morrison, Sherburne, Stearns49 min
Sep 20, 1:15 AM CDTSevere Thunderstorm WarningMPXBrown, Nicollet, Redwood, Renville, Sibley30 min
Sep 20, 1:21 AM CDTSevere Thunderstorm WarningDLHAitkin, Cass, Crow Wing39 min
Sep 20, 1:37 AM CDTSevere Thunderstorm WarningMPXMeeker, Sherburne, Stearns, Wright38 min
Sep 20, 1:41 AM CDTSevere Thunderstorm WarningMPXMcLeod, Renville, Sibley34 min
Sep 20, 1:49 AM CDTSevere Thunderstorm WarningMPXBenton, Kanabec, Mille Lacs, Morrison56 min
Sep 20, 1:50 AM CDTSevere Thunderstorm WarningDLHCass25 min
Sep 20, 2:00 AM CDTSevere Thunderstorm WarningMPXBenton, Isanti, Mille Lacs, Sherburne45 min
Sep 20, 2:10 AM CDTSevere Thunderstorm WarningDLHCass, Itasca20 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 00:00Z, 3.6 hours before the alert went out and 151 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-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2017-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 246 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2017-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 274 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
246 J/kg
Mixed-layer CIN
-155 J/kg
Mixed-layer LCL
1179 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
274 m²/s²
0-3 km storm-relative helicity
454 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 8:56 PM CDTMesoscale DiscussionSPCBecker, Big Stone, Clay, Clearwater, Grant, Kittson and 12 more2 hr
Sep 19, 10:10 PM CDTMesoscale DiscussionSPCBenton, Blue Earth, Brown, Carver, Cass, Chippewa and 37 more35 min
Sep 20, 1:03 AM CDTMesoscale DiscussionSPCAnoka, Benton, Blue Earth, Brown, Carver, Hennepin and 18 more87 min
Sep 20, 1:22 AM CDTSevere Thunderstorm WatchSPCAitkin, Anoka, Carlton, Carver, Chisago, Hennepin and 8 more4 hr

Nearby

Severe Thunderstorm Watches in Minnesota, 2017Every 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.