Alert archive / Missouri / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 156, NWS Kansas City, MO

July 21, 2020Pettis County, Missouri

NWS Kansas City, MO issued this severe thunderstorm warning at Jul 21, 2020, 4:17 PM CDT for Pettis County, Missouri. It was in force for 28 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 21, 2020, 4:17 PM CDT (21:17 UTC)
Expired: Jul 21, 2020, 4:45 PM CDT
In force: 28 min
Issued by: NWS Kansas City, MO
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Pettis County, MO

The radar

The Pleasant Hill radar (KEAX), 85 km from the middle of the area, began a volume at 21:20 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

Topeka, KS (KTOP), launched 12:00Z, 9.3 hours before the alert went out and 206 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: 4 J/kg
Mixed-layer CIN: -110 J/kg
Mixed-layer LCL: 878 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 26 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 Kansas City, MO wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 21, 2:07 PM CDT, 2 hours 10 minutes earlier.

Area forecast discussion, Jul 21, 2:07 PM CDT, 2 hours 10 minutes before

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Hazardous weather outlook, Jul 21, 5:34 AM CDT, 10 hours 43 minutes before

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In the hours before

Special weather statement, Jul 21, 2:20 PM CDT, 1 hour 57 minutes before

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Local storm report, Jul 21, 3:00 PM CDT, 1 hour 17 minutes before

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Special weather statement, Jul 21, 3:19 PM CDT, 58 minutes before

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Special weather statement, Jul 21, 3:40 PM CDT, 37 minutes before

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Special weather statement, Jul 21, 3:51 PM CDT, 26 minutes before

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The office that day

Everything else NWS Kansas City, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 8:56 PM CDT	River Flood Warning	EAX	Cass, Henry, Johnson	12 hr
Jul 20, 8:56 PM CDT	River Flood Warning	EAX	Bates, Cass, Henry	12 hr
Jul 21, 2:20 PM CDT	Special Weather Statement	EAX	Bates	40 min
Jul 21, 3:19 PM CDT	Special Weather Statement	EAX	Henry	41 min
Jul 21, 3:51 PM CDT	Special Weather Statement	EAX	Pettis	39 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2020 Every severe thunderstorm warning 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.