Alert archive / Iowa / Mesoscale Discussions in 2020

Mesoscale Discussion 1749

October 22, 20204 states

The Storm Prediction Center issued this mesoscale discussion at Oct 22, 2020, 4:53 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Oct 22, 2020, 4:53 PM CDT (21:53 UTC)
Expired
Oct 22, 2020, 7:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
40%
All 61 counties

Adair County, IA, Adams County, IA, Allamakee County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Cedar County, IA, Clarke County, IA, Clayton County, IA, Clinton County, IA, Dallas County, IA, Decatur County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Grundy County, IA, Hardin County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Page County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Carroll County, IL, Jo Daviess County, IL, Stephenson County, IL, Winnebago County, IL, Andrew County, MO, Gentry County, MO, Nodaway County, MO, Worth County, MO, Columbia County, WI, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Marquette County, WI, Richland County, WI, Rock County, WI, Sauk County, WI

The radar

The Quad Cities radar (KDVN), 110 km from the middle of the area, began a volume at 21:55 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 12:00Z, 9.9 hours before the alert went out and 113 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-pSkew-T log-p diagram, Davenport, at 12:00Z on 2020-10-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2020-10-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 536 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
409 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
536 m²/s²
0-3 km storm-relative helicity
523 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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Nearby

Mesoscale Discussions in Iowa, 2020Mesoscale Discussions in Wisconsin, 2020Mesoscale Discussions in Illinois, 2020Every mesoscale discussion in 2020

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.