Alert archive / Iowa / Mesoscale Discussions in 2018

Mesoscale Discussion 682

June 9, 201812 counties in Iowa; 4 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Jun 9, 2018, 1:46 PM CDT for 12 counties in Iowa; 4 counties in Minnesota. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: Jun 9, 2018, 1:46 PM CDT (18:46 UTC)
Expired: Jun 9, 2018, 3:45 PM CDT
In force: 119 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

Counties Bremer County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Floyd County, IA, Franklin County, IA, Hancock County, IA, Howard County, IA, Mitchell County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Mower County, MN

The radar

The Des Moines radar (KDMX), 167 km from the middle of the area, began a volume at 18:49 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.

Tornado Watch 165Jun 9, 2:25 PM CDT

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 6.8 hours before the alert went out and 189 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: 395 J/kg
Mixed-layer CIN: -155 J/kg
Mixed-layer LCL: 661 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 128 m²/s²
0-3 km storm-relative helicity: 154 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 8, 11:51 PM CDT	Mesoscale Discussion	SPC	Plymouth	84 min
Jun 9, 2:51 AM CDT	Mesoscale Discussion	SPC	Audubon, Carroll, Cass, Crawford, Fremont, Greene and 10 more	114 min
Jun 9, 2:26 PM CDT	Tornado Watch	SPC	Allamakee, Black Hawk, Bremer, Buchanan, Butler, Cerro Gordo and 18 more	5 hr
Jun 9, 3:52 PM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 23 more	83 min
Jun 9, 6:30 PM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 22 more	2 hr

Nearby

Mesoscale Discussions in Iowa, 2018 Mesoscale Discussions in Minnesota, 2018 Every mesoscale discussion in 2018

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.