Alert archive / Minnesota / Mesoscale Discussions in 2011

Mesoscale Discussion 1671

July 20, 20114 counties in Michigan; 8 counties in Minnesota; Ashland County, Bayfield County, Douglas County, Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2011, 6:55 PM CDT for 4 counties in Michigan; 8 counties in Minnesota; Ashland County, Bayfield County, Douglas County, Wisconsin. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Jul 20, 2011, 6:55 PM CDT (23:55 UTC)
Expired
Jul 20, 2011, 8:30 PM CDT
In force
95 min
Issued by
the Storm Prediction Center

Counties Gogebic County, MI, Houghton County, MI, Keweenaw County, MI, Ontonagon County, MI, Aitkin County, MN, Carlton County, MN, Cass County, MN, Cook County, MN, Itasca County, MN, Koochiching County, MN, Lake County, MN, Saint Louis County, MN, Ashland County, WI, Bayfield County, WI, Douglas County, WI

The radar

The Duluth radar (KDLH), 72 km from the middle of the area, began a volume at 23:55 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 nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 11.9 hours before the alert went out and 165 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, International Fa, MN at 12:00Z on 2011-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3428 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, International Fa, MN at 12:00Z on 2011-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 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
3428 J/kg
Mixed-layer CIN
-134 J/kg
Mixed-layer LCL
477 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 20, 5:02 AM CDTMesoscale DiscussionSPCClay, Clearwater, Kittson, Mahnomen, Marshall, Norman and 4 more88 min
Jul 20, 5:25 AM CDTSevere Thunderstorm WatchSPCBeltrami, Clearwater, Kittson, Lake of the Woods, Mahnomen, Marshall and 5 more6 hr
Jul 20, 10:43 AM CDTMesoscale DiscussionSPCBeltrami, Clearwater, Kittson, Marshall, Pennington, Polk and 2 more62 min
Jul 19, 7:38 PM CDTMesoscale DiscussionSPCAdams, Barron, Chippewa, Clark, Dunn, Eau Claire and 5 more67 min
Jul 19, 10:16 PM CDTMesoscale DiscussionSPCAdams, Brown, Calumet, Clark, Dodge, Fond du Lac and 23 more119 min
Jul 19, 11:27 PM CDTSevere Thunderstorm WatchSPCColumbia, Dane, Dodge, Fond du Lac, Green Lake, Jefferson and 11 more2 hr

Nearby

Mesoscale Discussions in Minnesota, 2011Mesoscale Discussions in Michigan, 2011Mesoscale Discussions in Wisconsin, 2011Every mesoscale discussion in 2011

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.