Alert archive / Minnesota / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 218

May 15, 201722 counties in Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at May 15, 2017, 9:48 PM CDT for 22 counties in Minnesota; 10 counties in Wisconsin. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 15, 2017, 9:48 PM CDT (02:48 UTC)
Expired
May 16, 2017, 3:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 32 counties

Blue Earth County, MN, Brown County, MN, Dakota County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Le Sueur County, MN, Martin County, MN, Mower County, MN, Nicollet County, MN, Olmsted County, MN, Rice County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Watonwan County, MN, Winona County, MN, Buffalo County, WI, Crawford County, WI, Jackson County, WI, La Crosse County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Richland County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The Minneapolis radar (KMPX), 90 km from the middle of the area, began a volume at 02:50 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
20%
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

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

IssuedProductOfficeCountiesLasted
May 15, 9:55 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Waseca35 min
May 15, 10:04 PM CDTSevere Thunderstorm WarningMPXSteele56 min
May 15, 10:08 PM CDTSevere Thunderstorm WarningARXFillmore, Houston, Winona67 min
May 15, 10:17 PM CDTSevere Thunderstorm WarningARXDodge23 min
May 15, 10:25 PM CDTSevere Thunderstorm WarningARXOlmsted, Wabasha, Winona41 min
May 15, 10:25 PM CDTSevere Thunderstorm WarningMPXGoodhue26 min
May 15, 11:30 PM CDTSevere Thunderstorm WarningARXDodge33 min
May 16, 12:12 AM CDTFlash Flood WarningARXOlmsted, Wabasha, Winona7 hr

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, 2.8 hours before the alert went out and 91 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 2017-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2017-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1282 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
111 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.

IssuedProductOfficeCountiesLasted
May 15, 8:50 PM CDTMesoscale DiscussionSPCBlue Earth, Brown, Cottonwood, Dakota, Dodge, Faribault and 19 more115 min
May 15, 11:54 PM CDTSevere Thunderstorm WatchSPCCottonwood, Jackson, Nobles, Rock3 hr
May 16, 2:13 AM CDTMesoscale DiscussionSPCBlue Earth, Brown, Cottonwood, Dodge, Faribault, Fillmore and 22 more92 min
May 16, 3:32 PM CDTMesoscale DiscussionSPCAnoka, Blue Earth, Brown, Carver, Chisago, Dakota and 28 more88 min
May 16, 4:08 PM CDTSevere Thunderstorm WatchSPCAnoka, Blue Earth, Brown, Carver, Chisago, Dakota and 16 more4 hr
May 15, 7:19 PM CDTMesoscale DiscussionSPCCrawford, Dane, Grant, Green, Iowa, Lafayette and 4 more56 min
May 15, 7:52 PM CDTSevere Thunderstorm WatchSPCDane, Green, Iowa, Jefferson, Kenosha, Lafayette and 3 more3 hr
May 15, 10:14 PM CDTMesoscale DiscussionSPCJefferson, Kenosha, Rock, Walworth, Waukesha61 min
May 16, 12:57 PM CDTMesoscale DiscussionSPCBuffalo, Clark, Eau Claire, Jackson, Marathon, Menominee and 7 more2 hr
May 16, 4:02 PM CDTTornado WatchSPCAshland, Barron, Bayfield, Buffalo, Burnett, Chippewa and 24 more6 hr
May 16, 6:25 PM CDTMesoscale DiscussionSPCAshland, Barron, Bayfield, Brown, Buffalo, Burnett and 32 more65 min

Nearby

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