Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 104, NWS Kansas City, MO

August 12, 2021Leavenworth County, Kansas; Clay County, Platte County, Missouri

NWS Kansas City, MO issued this severe thunderstorm warning at Aug 12, 2021, 3:28 PM CDT for Leavenworth County, Kansas; Clay County, Platte County, Missouri. It was in force for 32 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 12, 2021, 3:28 PM CDT (20:28 UTC)
Expired: Aug 12, 2021, 4:00 PM CDT
In force: 32 min
Issued by: NWS Kansas City, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Leavenworth County, KS, Clay County, MO, Platte County, MO

The radar

The Pleasant Hill radar (KEAX), 79 km from the middle of the area, began a volume at 20:30 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.

What was reported inside it

Time	Report	Where
Aug 12, 3:36 PM CDT	HAIL 1	Platte City, MO
Aug 12, 3:56 PM CDT	HAIL 1	4 Nnw Weatherby Lake, MO
Aug 12, 4:00 PM CDT	TSTM WND GST 60	Kansas City Intl Airpor, MO

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 8.5 hours before the alert went out and 92 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: 951 J/kg
Mixed-layer CIN: -437 J/kg
Mixed-layer LCL: 1729 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: 141 m²/s²
0-3 km storm-relative helicity: 228 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

As transmitted.

267 
WUUS53 KEAX 122028
SVREAX
KSC103-MOC047-165-122100-
/O.NEW.KEAX.SV.W.0104.210812T2028Z-210812T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Kansas City/Pleasant Hill MO
328 PM CDT Thu Aug 12 2021

The National Weather Service in Pleasant Hill has issued a

* Severe Thunderstorm Warning for...
  North central Leavenworth County in northeastern Kansas...
  Northwestern Clay County in west central Missouri...
  Northeastern Platte County in west central Missouri...

* Until 400 PM CDT.

* At 328 PM CDT, a severe thunderstorm was located over Weston,
  moving east at 35 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Kansas City, Leavenworth, Smithville, Platte City, Weston, Lake
  Waukomis, Camden Point, Ferrelview, Platte Woods, Tracy, Ridgely,
  Fort Leavenworth, Beverly, Kansas City Intl Arpt and Hoover.

This includes the following highways...
 Interstate 29 between mile markers 8 and 28.
 Interstate 435 between mile markers 27 and 41.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3952 9490 3947 9460 3946 9460 3945 9450
      3921 9460 3937 9497
TIME...MOT...LOC 2028Z 286DEG 29KT 3941 9485 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HB

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 12, 3:56 PM CDT	Severe Thunderstorm Warning	EAX	Wyandotte	34 min
Aug 12, 5:18 PM CDT	Severe Thunderstorm Warning	EAX	Johnson	27 min
Aug 12, 4:29 AM CDT	Special Weather Statement	EAX	Harrison	31 min
Aug 12, 4:58 AM CDT	Special Weather Statement	EAX	Mercer	47 min
Aug 12, 5:31 AM CDT	Severe Thunderstorm Warning	EAX	Harrison, Mercer	29 min
Aug 12, 6:00 AM CDT	Special Weather Statement	EAX	Mercer	30 min
Aug 12, 8:37 AM CDT	Special Weather Statement	EAX	Schuyler	8 min
Aug 12, 8:38 AM CDT	Special Weather Statement	EAX	Schuyler	37 min
Aug 12, 1:27 PM CDT	Flash Flood Watch	EAX	Putnam, Schuyler	6 hr
Aug 12, 1:42 PM CDT	Special Weather Statement	EAX	Daviess, Grundy, Sullivan	48 min
Aug 12, 1:45 PM CDT	Special Weather Statement	EAX	Schuyler	30 min
Aug 12, 2:15 PM CDT	Flash Flood Warning	EAX	Putnam, Schuyler	2 hr
Aug 12, 2:16 PM CDT	Special Weather Statement	EAX	Caldwell, Linn, Livingston	29 min
Aug 12, 2:18 PM CDT	Severe Thunderstorm Warning	EAX	Grundy, Linn, Livingston	27 min
Aug 12, 2:31 PM CDT	Severe Thunderstorm Warning	EAX	Caldwell, Carroll, Daviess, Linn, Livingston	29 min
Aug 12, 2:49 PM CDT	Severe Thunderstorm Warning	EAX	Carroll, Chariton, Livingston	26 min
Aug 12, 3:13 PM CDT	Severe Thunderstorm Warning	EAX	Carroll, Chariton, Livingston, Saline	32 min
Aug 12, 3:44 PM CDT	Severe Thunderstorm Warning	EAX	Chariton, Macon, Randolph	31 min
Aug 12, 3:53 PM CDT	Severe Thunderstorm Warning	EAX	Randolph	37 min
Aug 12, 4:09 PM CDT	Severe Thunderstorm Warning	EAX	Clay, Jackson, Lafayette, Ray, Saline	36 min
Aug 12, 4:42 PM CDT	Severe Thunderstorm Warning	EAX	Jackson, Johnson, Lafayette	33 min
Aug 12, 5:11 PM CDT	Severe Thunderstorm Warning	EAX	Cass, Jackson, Johnson, Lafayette	34 min
Aug 12, 5:22 PM CDT	Severe Thunderstorm Warning	EAX	Jackson	8 min
Aug 12, 5:37 PM CDT	Severe Thunderstorm Warning	EAX	Cass, Jackson, Johnson	8 min
Aug 12, 5:43 PM CDT	Severe Thunderstorm Warning	EAX	Cass, Jackson, Johnson	32 min
Aug 12, 6:15 PM CDT	Special Weather Statement	EAX	Cass	45 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2021 Severe Thunderstorm Warnings in Kansas, 2021 Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.