Alert archive / Minnesota / Mesoscale Discussions in 2017

Mesoscale Discussion 1660

September 19, 201743 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Sep 19, 2017, 10:10 PM CDT for 43 counties in Minnesota. It was in force for 35 min.

The area

The outline as issued.

The facts

Issued: Sep 19, 2017, 10:10 PM CDT (03:10 UTC)
Expired: Sep 19, 2017, 10:45 PM CDT
In force: 35 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 43 counties

Benton County, MN, Blue Earth County, MN, Brown County, MN, Carver County, MN, Cass County, MN, Chippewa County, MN, Cottonwood County, MN, Crow Wing County, MN, Douglas County, MN, Faribault County, MN, Grant County, MN, Jackson County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Le Sueur County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, McLeod County, MN, Meeker County, MN, Mille Lacs 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, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Wadena County, MN, Waseca County, MN, Watonwan County, MN, Wright County, MN, Yellow Medicine County, MN

The radar

The Minneapolis radar (KMPX), 133 km from the middle of the area, began a volume at 03:09 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 3.2 hours before the alert went out and 131 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: 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

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 19, 8:56 PM CDT	Mesoscale Discussion	SPC	Becker, Big Stone, Clay, Clearwater, Grant, Kittson and 12 more	2 hr
Sep 19, 10:36 PM CDT	Severe Thunderstorm Watch	SPC	Becker, Beltrami, Benton, Brown, Cass, Chippewa and 30 more	4 hr
Sep 20, 1:03 AM CDT	Mesoscale Discussion	SPC	Anoka, Benton, Blue Earth, Brown, Carver, Hennepin and 18 more	87 min
Sep 20, 1:22 AM CDT	Severe Thunderstorm Watch	SPC	Aitkin, Anoka, Carlton, Carver, Chisago, Hennepin and 8 more	4 hr

Nearby

Mesoscale Discussions in Minnesota, 2017 Every mesoscale discussion 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.