Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 109, NWS Kansas City, MO

August 12, 2021Jackson County, Johnson County, Lafayette County, Missouri

NWS Kansas City, MO issued this severe thunderstorm warning at Aug 12, 2021, 4:42 PM CDT for Jackson County, Johnson County, Lafayette County, Missouri. It was in force for 33 min. 8 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, 4:42 PM CDT (21:42 UTC)
Expired: Aug 12, 2021, 5:15 PM CDT
In force: 33 min
Issued by: NWS Kansas City, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Jackson County, MO, Johnson County, MO, Lafayette County, MO

The radar

The Pleasant Hill radar (KEAX), 20 km from the middle of the area, began a volume at 21:44 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	Remark
Aug 12, 4:45 PM CDT	TSTM WND DMG	2 Sse Blue Springs, MO	TREE LIMBS DOWNED
Aug 12, 4:45 PM CDT	TSTM WND DMG	3 Sse Blue Springs, MO	FENCE DESTROYED, TREE LIMBS DOWNDED, AND BBQ GRILL THROWN SEVERAL YARDS OVER DUE TO STRONG WINDS.
Aug 12, 4:45 PM CDT	TSTM WND DMG	3 Sse Blue Springs, MO	FENCE DESTROYED, TREE LIMBS DOWNED, AND BBQ GRILL THROWN A FEW YARDS DOWN DUE TO STRONG WIND GUSTS.
Aug 12, 4:47 PM CDT	HAIL 1.75	2 Nne Blue Springs, MO
Aug 12, 4:54 PM CDT	HAIL 1.25	2 Ne Blue Springs, MO	DELAYED REPORT...
Aug 12, 5:00 PM CDT	HAIL 1	Oak Grove, MO	DELAYED REPORT...
Aug 12, 5:00 PM CDT	HAIL 1.25	2 Ne Blue Springs, MO	DELAYED REPORT...
Aug 12, 5:02 PM CDT	HAIL 1.25	3 Ne Blue Springs, MO	DELAYED REPORT...

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, 9.7 hours before the alert went out and 126 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.

352 
WUUS53 KEAX 122142
SVREAX
MOC095-101-107-122215-
/O.NEW.KEAX.SV.W.0109.210812T2142Z-210812T2215Z/

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

The National Weather Service in Pleasant Hill has issued a

* Severe Thunderstorm Warning for...
  Southwestern Lafayette County in west central Missouri...
  Southeastern Jackson County in west central Missouri...
  Northwestern Johnson County in west central Missouri...

* Until 515 PM CDT.

* At 442 PM CDT, a severe thunderstorm was located over Grain Valley,
  moving southeast at 20 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...
  Independence, Lee's Summit, Blue Springs, Grain Valley, Oak Grove,
  Odessa, Lake Lotawana, Lone Jack, Lake Tapawingo, Lake Lafayette,
  Bates City and Tarsney Lakes.

This includes the following highways...
 Interstate 70 in Missouri between mile markers 18 and 40.
 Interstate 470 between mile markers 10 and 12.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3893 9438 3909 9430 3913 9381 3881 9405
TIME...MOT...LOC 2142Z 299DEG 19KT 3903 9419 

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, 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, 3:28 PM CDT	Severe Thunderstorm Warning	EAX	Clay, Platte	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, 3:56 PM CDT	Severe Thunderstorm Warning	EAX	Clay, Jackson, Platte	34 min
Aug 12, 4:09 PM CDT	Severe Thunderstorm Warning	EAX	Clay, Jackson, Lafayette, Ray, Saline	36 min
Aug 12, 5:11 PM CDT	Severe Thunderstorm Warning	EAX	Cass, Jackson, Johnson, Lafayette	34 min
Aug 12, 5:18 PM CDT	Severe Thunderstorm Warning	EAX	Cass, Jackson	27 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 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.