Alert archive / Wisconsin / Mesoscale Discussions in 2011

Mesoscale Discussion 1830

August 2, 2011Chisago County, Ramsey County, Washington County, Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 2, 2011, 9:02 AM CDT for Chisago County, Ramsey County, Washington County, Minnesota; 10 counties in Wisconsin. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Aug 2, 2011, 9:02 AM CDT (14:02 UTC)
Expired: Aug 2, 2011, 10:00 AM CDT
In force: 58 min
Issued by: the Storm Prediction Center

Counties Chisago County, MN, Ramsey County, MN, Washington County, MN, Barron County, WI, Chippewa County, WI, Dunn County, WI, Eau Claire County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Rusk County, WI, Saint Croix County, WI, Taylor County, WI

The radar

The Minneapolis radar (KMPX), 141 km from the middle of the area, began a volume at 14:05 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

Minneapolis, MN (KMPX), launched 12:00Z, 2.0 hours before the alert went out and 144 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: 2133 J/kg
Mixed-layer CIN: -209 J/kg
Mixed-layer LCL: 850 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 233 m²/s²
0-3 km storm-relative helicity: 194 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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.

Issued	Product	Office	Counties	Lasted
Aug 1, 9:40 PM CDT	Mesoscale Discussion	SPC	Aitkin, Anoka, Becker, Benton, Big Stone, Carlton and 29 more	95 min
Aug 1, 10:35 PM CDT	Severe Thunderstorm Watch	SPC	Aitkin, Becker, Carlton, Cass, Clay, Crow Wing and 11 more	7 hr
Aug 2, 1:24 AM CDT	Mesoscale Discussion	SPC	Aitkin, Anoka, Benton, Carlton, Chisago, Crow Wing and 5 more	96 min
Aug 2, 3:32 AM CDT	Mesoscale Discussion	SPC	Aitkin, Anoka, Benton, Carlton, Chisago, Crow Wing and 5 more	88 min
Aug 2, 5:23 AM CDT	Severe Thunderstorm Watch	SPC	Anoka, Benton, Big Stone, Carver, Chippewa, Chisago and 25 more	7 hr
Aug 2, 12:57 PM CDT	Mesoscale Discussion	SPC	Houston	93 min
Aug 2, 2:20 AM CDT	Severe Thunderstorm Watch	SPC	Ashland, Barron, Bayfield, Burnett, Chippewa, Clark and 24 more	10 hr
Aug 2, 6:19 AM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Chippewa, Clark, Columbia and 32 more	86 min
Aug 2, 11:51 AM CDT	Mesoscale Discussion	SPC	Ashland, Barron, Bayfield, Burnett, Chippewa, Douglas and 11 more	24 min
Aug 2, 5:22 PM CDT	Severe Thunderstorm Watch	SPC	Kenosha, Milwaukee, Racine, Rock, Walworth, Waukesha	9 hr

Nearby

Mesoscale Discussions in Wisconsin, 2011 Mesoscale Discussions in Minnesota, 2011 Every 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.