Alert archive / Iowa / Mesoscale Discussions in 2018

Mesoscale Discussion 966

June 30, 201817 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Jun 30, 2018, 7:15 PM CDT for 17 counties in Iowa. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: Jun 30, 2018, 7:15 PM CDT (00:15 UTC)
Expired: Jun 30, 2018, 8:45 PM CDT
In force: 90 min
Issued by: the Storm Prediction Center

Counties Benton County, IA, Cedar County, IA, Clinton County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Marshall County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Tama County, IA, Washington County, IA

The radar

The Quad Cities radar (KDVN), 108 km from the middle of the area, began a volume at 00:16 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

Davenport, (KDVN), launched 00:00Z, 0.3 hours before the alert went out and 114 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: 3950 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 1125 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 123 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.0

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 30, 8:05 PM CDT	Mesoscale Discussion	SPC	Allamakee, Chickasaw, Clayton, Fayette, Winneshiek	85 min
Jun 30, 8:55 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Cass, Fremont, Harrison and 8 more	95 min
Jul 1, 12:48 AM CDT	Mesoscale Discussion	SPC	Harrison, Mills, Pottawattamie, Shelby	117 min

Nearby

Mesoscale Discussions in Iowa, 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.