Alert archive / Minnesota / Mesoscale Discussions in 2007

Mesoscale Discussion 1909

August 28, 200711 counties in Minnesota; 4 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 28, 2007, 1:50 AM CDT for 11 counties in Minnesota; 4 counties in Wisconsin. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Aug 28, 2007, 1:50 AM CDT (06:50 UTC)
Expired: Aug 28, 2007, 2:45 AM CDT
In force: 55 min
Issued by: the Storm Prediction Center

Counties Anoka County, MN, Carver County, MN, Chisago County, MN, Hennepin County, MN, Isanti County, MN, McLeod County, MN, Ramsey County, MN, Scott County, MN, Sherburne County, MN, Washington County, MN, Wright County, MN, Barron County, WI, Dunn County, WI, Polk County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 25 km from the middle of the area, began a volume at 06:51 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.

Severe Thunderstorm Watch 657Aug 28, 2:00 AM CDT

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 6.8 hours before the alert went out and 27 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: 2564 J/kg
Mixed-layer CIN: -230 J/kg
Mixed-layer LCL: 806 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 379 m²/s²
0-3 km storm-relative helicity: 526 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 8.1

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 27, 9:05 PM CDT	Mesoscale Discussion	SPC	Aitkin, Carlton, Crow Wing, Lake, Morrison, Pine	55 min
Aug 27, 9:49 PM CDT	Mesoscale Discussion	SPC	Lincoln, Yellow Medicine	86 min
Aug 28, 1:56 AM CDT	Severe Thunderstorm Watch	SPC	Anoka, Brown, Carver, Chisago, Dakota, Goodhue and 10 more	3 hr
Aug 28, 11:58 AM CDT	Mesoscale Discussion	SPC	Dodge, Goodhue, Mower, Olmsted, Wabasha, Winona	62 min
Aug 28, 12:15 PM CDT	Severe Thunderstorm Watch	SPC	Blue Earth, Brown, Carver, Dakota, Dodge, Faribault and 20 more	8 hr
Aug 28, 3:24 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Dodge, Faribault, Fillmore, Freeborn, Goodhue and 10 more	66 min
Aug 28, 3:48 AM CDT	Mesoscale Discussion	SPC	Chippewa, Clark, Dunn, Eau Claire, Forest, Langlade and 8 more	87 min
Aug 28, 4:17 AM CDT	Severe Thunderstorm Watch	SPC	Clark, Door, Florence, Forest, Langlade, Lincoln and 7 more	4 hr
Aug 28, 6:04 PM CDT	Mesoscale Discussion	SPC	Crawford, Richland, Vernon	3 hr
Aug 28, 6:28 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Columbia, Crawford, Fond du Lac and 9 more	62 min

Nearby

Mesoscale Discussions in Minnesota, 2007 Mesoscale Discussions in Wisconsin, 2007 Every mesoscale discussion in 2007

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.