Alert archive / Iowa / Mesoscale Discussions in 2014

Mesoscale Discussion 1593

August 21, 20144 states

The Storm Prediction Center issued this mesoscale discussion at Aug 21, 2014, 9:04 AM CDT for 4 states. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Aug 21, 2014, 9:04 AM CDT (14:04 UTC)
Expired: Aug 21, 2014, 10:30 AM CDT
In force: 86 min
Issued by: the Storm Prediction Center

All 87 counties

Allamakee County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cedar County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Howard County, IA, Humboldt County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Marshall County, IA, Mitchell County, IA, Scott County, IA, Story County, IA, Tama County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Boone County, IL, Carroll County, IL, Jo Daviess County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Stephenson County, IL, Whiteside County, IL, Winnebago County, IL, Fillmore County, MN, Freeborn County, MN, Houston County, MN, Mower County, MN, Adams County, WI, Calumet County, WI, Chippewa County, WI, Clark County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jefferson County, WI, Juneau County, WI, La Crosse County, WI, Lafayette County, WI, Lincoln County, WI, Marathon County, WI, Marquette County, WI, Milwaukee County, WI, Monroe County, WI, Outagamie County, WI, Ozaukee County, WI, Portage County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Taylor County, WI, Vernon County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 46 km from the middle of the area, began a volume at 14:06 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, 2.1 hours before the alert went out and 257 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: 236 J/kg
Mixed-layer CIN: -150 J/kg
Mixed-layer LCL: 975 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 73 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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 21, 5:12 PM CDT	Mesoscale Discussion	SPC	Ford, Iroquois, Kankakee, Will	2 hr
Aug 21, 5:39 PM CDT	Severe Thunderstorm Watch	SPC	Iroquois, Kankakee	5 hr
Aug 20, 9:07 PM CDT	Mesoscale Discussion	SPC	Lyon, Plymouth, Sioux	2 hr
Aug 21, 3:58 AM CDT	Mesoscale Discussion	SPC	Dickinson, Emmet, Osceola	92 min
Aug 21, 5:15 AM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Cerro Gordo, Chickasaw, Clayton, Fayette, Floyd and 6 more	5 hr
Aug 21, 12:29 AM CDT	Mesoscale Discussion	SPC	Benton, Big Stone, Blue Earth, Brown, Carver, Chippewa and 32 more	2 hr
Aug 21, 1:00 AM CDT	Severe Thunderstorm Watch	SPC	Blue Earth, Brown, Carver, Chippewa, Douglas, Faribault and 22 more	6 hr

Nearby

Mesoscale Discussions in Iowa, 2014 Mesoscale Discussions in Wisconsin, 2014 Mesoscale Discussions in Illinois, 2014 Every mesoscale discussion in 2014

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.