Alert archive / Minnesota / Mesoscale Discussions in 2004

Mesoscale Discussion 1746

July 20, 20044 counties in Iowa; 20 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2004, 11:08 PM CDT for 4 counties in Iowa; 20 counties in Minnesota. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Jul 20, 2004, 11:08 PM CDT (04:08 UTC)
Expired: Jul 21, 2004, 12:45 AM CDT
In force: 97 min
Issued by: the Storm Prediction Center

All 24 counties

Howard County, IA, Mitchell County, IA, Winnebago County, IA, Worth County, IA, Blue Earth County, MN, Carver County, MN, Dakota County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Le Sueur County, MN, Martin County, MN, McLeod 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

The radar

The Minneapolis radar (KMPX), 103 km from the middle of the area, began a volume at 04:11 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 00:00Z, 4.1 hours before the alert went out and 104 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: 1847 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 1144 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 66 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
Jul 21, 9:03 AM CDT	Mesoscale Discussion	SPC	Benton, Cedar, Clinton, Des Moines, Henry, Iowa and 17 more	117 min
Jul 21, 9:35 AM CDT	Severe Thunderstorm Watch	SPC	Appanoose, Benton, Cedar, Clinton, Davis, Des Moines and 24 more	5 hr
Jul 21, 1:01 PM CDT	Mesoscale Discussion	SPC	Appanoose, Benton, Cedar, Clinton, Davis, Des Moines and 22 more	89 min
Jul 21, 3:43 PM CDT	Mesoscale Discussion	SPC	Cherokee, Clay, Dickinson, Lyon, O'Brien, Osceola and 2 more	92 min
Jul 21, 6:02 PM CDT	Mesoscale Discussion	SPC	Buena Vista, Cherokee, Clay, Crawford, Dickinson, Emmet and 9 more	118 min
Jul 20, 9:00 PM CDT	Severe Thunderstorm Watch	SPC	Big Stone, Chippewa, Cottonwood, Jackson, Kandiyohi, Lac qui Parle and 10 more	4 hr
Jul 21, 1:30 PM CDT	Mesoscale Discussion	SPC	Big Stone, Lac qui Parle, Traverse	2 hr
Jul 21, 1:50 PM CDT	Severe Thunderstorm Watch	SPC	Big Stone, Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle and 9 more	5 hr

Nearby

Mesoscale Discussions in Minnesota, 2004 Mesoscale Discussions in Iowa, 2004 Every mesoscale discussion in 2004

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.