Alert archive / Iowa / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 154, NWS Des Moines, IA

July 20, 20194 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 20, 2019, 4:59 PM CDT for 4 counties in Iowa. It was in force for 46 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 20, 2019, 4:59 PM CDT (21:59 UTC)
Expired: Jul 20, 2019, 5:45 PM CDT
In force: 46 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Jasper County, IA, Polk County, IA, Story County, IA, Warren County, IA

The radar

The Des Moines radar (KDMX), 26 km from the middle of the area, began a volume at 22:02 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 20, 4:58 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.0 hours before the alert went out and 242 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: 2651 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 1133 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 129 m²/s²
0-3 km storm-relative helicity: 169 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 20, 3:23 PM CDT, 1 hour 36 minutes earlier.

Area forecast discussion, Jul 20, 3:23 PM CDT, 1 hour 36 minutes before

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Hazardous weather outlook, Jul 20, 3:31 PM CDT, 1 hour 28 minutes before

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In the hours before

Local storm report, Jul 20, 12:33 PM CDT, 4 hours 26 minutes before

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Special weather statement, Jul 20, 12:43 PM CDT, 4 hours 16 minutes before

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Local storm report, Jul 20, 12:56 PM CDT, 4 hours 3 minutes before

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Local storm report, Jul 20, 1:22 PM CDT, 3 hours 37 minutes before

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Local storm report, Jul 20, 1:31 PM CDT, 3 hours 28 minutes before

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      <p class="small" id="detail">
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Special weather statement, Jul 20, 3:56 PM CDT, 1 hour 3 minutes before

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      <p id="message2">
        Please try again in a few minutes.
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The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 9:42 AM CDT	Severe Thunderstorm Warning	DMX	Emmet, Palo Alto	48 min
Jul 20, 10:15 AM CDT	Severe Thunderstorm Warning	DMX	Humboldt, Kossuth, Palo Alto, Pocahontas	60 min
Jul 20, 10:37 AM CDT	Special Weather Statement	DMX	Emmet, Palo Alto	53 min
Jul 20, 10:53 AM CDT	Special Weather Statement	DMX	Cerro Gordo, Franklin, Hancock, Humboldt, Winnebago, Worth and 1 more	52 min
Jul 20, 11:04 AM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Hancock, Winnebago, Worth	41 min
Jul 20, 11:24 AM CDT	Special Weather Statement	DMX	Boone, Butler, Grundy, Hamilton, Hardin, Story	51 min
Jul 20, 11:35 AM CDT	Severe Thunderstorm Warning	DMX	Butler, Franklin, Grundy, Hamilton, Hardin	40 min
Jul 20, 12:18 PM CDT	Special Weather Statement	DMX	Black Hawk, Grundy, Marshall, Story, Tama	57 min
Jul 20, 12:43 PM CDT	Special Weather Statement	DMX	Kossuth, Palo Alto	62 min
Jul 20, 3:56 PM CDT	Special Weather Statement	DMX	Greene	49 min
Jul 20, 4:14 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Greene	46 min
Jul 20, 4:28 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Polk	47 min
Jul 20, 5:29 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion, Polk, Warren	46 min
Jul 20, 5:58 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Lucas, Mahaska, Marion, Monroe, Poweshiek and 2 more	47 min
Jul 20, 6:27 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Davis, Lucas, Mahaska, Monroe, Wapello and 1 more	63 min
Jul 20, 6:41 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Dallas, Guthrie, Madison	49 min
Jul 20, 6:48 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska, Poweshiek	42 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2019 Every severe thunderstorm warning in 2019

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.