Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 126, NWS Kansas City, MO

August 20, 20214 counties in Missouri; Johnson County, Leavenworth County, Wyandotte County, Kansas

NWS Kansas City, MO issued this severe thunderstorm warning at Aug 20, 2021, 10:44 PM CDT for 4 counties in Missouri; Johnson County, Leavenworth County, Wyandotte County, Kansas. It was in force for 46 min. 11 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 20, 2021, 10:44 PM CDT (03:44 UTC)
Expired
Aug 20, 2021, 11:30 PM CDT
In force
46 min
Issued by
NWS Kansas City, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Johnson County, KS, Leavenworth County, KS, Wyandotte County, KS, Cass County, MO, Clay County, MO, Jackson County, MO, Platte County, MO

The radar

The Pleasant Hill radar (KEAX), 62 km from the middle of the area, began a volume at 03:44 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

TimeReportWhereRemark
Aug 20, 10:45 PM CDTTSTM WND DMGLansing, KSTREE DOWN ON HOUSE IN LANSING.
Aug 20, 10:55 PM CDTTSTM WND DMG3 N De Soto, KSTREE KNOCKED DOWN ONTO POWER LINES AT 171ST AND CANTRELL ROAD.
Aug 20, 10:57 PM CDTTSTM WND DMG2 Ssw Beverly Hills, KSTWO INCH BRANCHES KNOCKED DOWN.
Aug 20, 10:57 PM CDTTSTM WND DMG2 Sw Beverly Hills, KSTHREE INCH BRANCHES KNOCKED DOWN.
Aug 20, 10:58 PM CDTTSTM WND DMG4 N Oakview, MOREPORT FROM MPING: 1-INCH TREE LIMBS BROKEN; SHINGLES BLOWN OFF.
Aug 20, 11:00 PM CDTTSTM WND DMGWestwood, KSDELAYED REPORT POWER LINES DOWN, PEOPLE ARE STILL OUT OF POWER AS OF 11:30 AM 8/21.
Aug 20, 11:06 PM CDTTSTM WND DMG1 Sse Merriam, KSREPORT FROM MPING: 1-INCH TREE LIMBS BROKEN; SHINGLES BLOWN OFF.
Aug 20, 11:09 PM CDTTSTM WND GST 644 Ne Lake Waukomis, MO1 INCH TREE LIMBS BROKEN, 2-3 INCH THICK BRANCHES DOWN. 64 MPH MEASURED BY AUTOMATED WEATHER EQUIPMENT.
Aug 20, 11:15 PM CDTTSTM WND GST 653 S Independence, MOSMALL TO MED SIZED TREE LIMBS DOWN. REPORT VIA SOCIAL MEDIA.
Aug 20, 11:17 PM CDTTSTM WND DMGRaytown, MOSMALL TREE LIMBS DOWN IN RAYTOWN. REPORT VIA SOCIAL MEDIA.
Aug 20, 11:19 PM CDTTSTM WND DMG3 Ne Raytown, MOREPORT FROM MPING: 1-INCH TREE LIMBS BROKEN; SHINGLES BLOWN OFF.

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

The watch it was issued in

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

IssuedProductOfficeLasted
Aug 20, 7:40 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 3.7 hours before the alert went out and 61 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, Topeka, KS at 00:00Z on 2021-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3676 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Topeka, KS at 00:00Z on 2021-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 square meters per square second.193958Sfc1 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
3676 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
1017 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
242 m²/s²
Significant tornado parameter
3.1
Supercell composite
18.5

Open this sounding in Storm Lab

The text

As transmitted.

709 
WUUS53 KEAX 210344
SVREAX
KSC091-103-209-MOC037-047-095-165-210430-
/O.NEW.KEAX.SV.W.0126.210821T0344Z-210821T0430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Kansas City/Pleasant Hill MO
1044 PM CDT Fri Aug 20 2021

The National Weather Service in Pleasant Hill has issued a

* Severe Thunderstorm Warning for...
  Wyandotte County in northeastern Kansas...
  Leavenworth County in northeastern Kansas...
  Johnson County in east central Kansas...
  Northwestern Cass County in west central Missouri...
  Southwestern Clay County in west central Missouri...
  Southeastern Platte County in west central Missouri...
  Western Jackson County in west central Missouri...

* Until 1130 PM CDT.

* At 1044 PM CDT, a severe thunderstorm was located near Linwood, or
  near Tonganoxie, moving east at 50 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Kansas City, Overland Park, Olathe, Independence, Lee's Summit,
  Shawnee, Lenexa, Leavenworth, Leawood, Raytown, Liberty, Gladstone,
  Grandview, Belton, Prairie Village, Raymore, Gardner, Lansing,
  Merriam and Mission.

This includes the following highways...
 Interstate 70 in Missouri between mile markers 0 and 17.
 Interstate 70 in Kansas between mile markers 410 and 423.
 Interstate 35 in Missouri between mile markers 0 and 16.
 Interstate 35 in Kansas between mile markers 209 and 235.
 Interstate 29 between mile markers 0 and 13.
 Interstate 635 between mile markers 0 and 12.
 Interstate 470 between mile markers 0 and 9, and between mile
markers 13 and 16.
 Interstate 435 between mile markers 0 and 28, between mile markers
36 and 42, and between mile markers 46 and 83.
 Kansas Turnpike between mile markers 206 and 226.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3928 9517 3932 9455 3914 9428 3882 9443
      3877 9461 3880 9505 3898 9506 3899 9507
      3898 9509 3896 9508 3898 9516 3896 9517
      3897 9519
TIME...MOT...LOC 0344Z 289DEG 44KT 3904 9508 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Leighton
3 follow-up statements
433 
WWUS53 KEAX 210358
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
1058 PM CDT Fri Aug 20 2021

KSC091-103-209-MOC037-047-095-165-210430-
/O.CON.KEAX.SV.W.0126.000000T0000Z-210821T0430Z/
Wyandotte KS-Leavenworth KS-Johnson KS-Cass MO-Clay MO-Platte MO-
Jackson MO-
1058 PM CDT Fri Aug 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 PM CDT
FOR WYANDOTTE...SOUTHEASTERN LEAVENWORTH...JOHNSON...NORTHWESTERN
CASS...SOUTHWESTERN CLAY...SOUTHEASTERN PLATTE AND WESTERN JACKSON
COUNTIES...

At 1058 PM CDT, a severe thunderstorm was located near Kansas City
Kansas, moving east at 50 mph.

HAZARD...70 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Kansas City, Overland Park, Olathe, Independence, Lee's Summit,
Shawnee, Lenexa, Leawood, Raytown, Liberty, Gladstone, Grandview,
Belton, Prairie Village, Raymore, Gardner, Merriam, Mission, Bonner
Springs and De Soto.

This includes the following highways...
 Interstate 70 in Missouri between mile markers 0 and 17.
 Interstate 70 in Kansas between mile markers 410 and 423.
 Interstate 35 in Missouri between mile markers 0 and 16.
 Interstate 35 in Kansas between mile markers 209 and 235.
 Interstate 29 between mile markers 0 and 10.
 Interstate 635 between mile markers 0 and 12.
 Interstate 470 between mile markers 0 and 9, and between mile
markers 13 and 16.
 Interstate 435 between mile markers 0 and 24, between mile markers
39 and 42, and between mile markers 46 and 83.
 Kansas Turnpike between mile markers 219 and 226.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3914 9428 3882 9443 3877 9461 3880 9505
      3898 9505 3920 9488 3932 9458 3932 9455
TIME...MOT...LOC 0358Z 291DEG 42KT 3908 9469 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Leighton
672 
WWUS53 KEAX 210410
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
1110 PM CDT Fri Aug 20 2021

KSC103-210419-
/O.CAN.KEAX.SV.W.0126.000000T0000Z-210821T0430Z/
Leavenworth KS-
1110 PM CDT Fri Aug 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LEAVENWORTH
COUNTY IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
northeastern and east central Kansas...and west central Missouri.

LAT...LON 3900 9492 3898 9492 3899 9491 3902 9491
      3914 9483 3924 9459 3914 9428 3882 9443
      3877 9461 3880 9505
TIME...MOT...LOC 0409Z 289DEG 44KT 3903 9451 

$$

KSC091-209-MOC037-047-095-165-210430-
/O.CON.KEAX.SV.W.0126.000000T0000Z-210821T0430Z/
Wyandotte KS-Johnson KS-Cass MO-Clay MO-Platte MO-Jackson MO-
1110 PM CDT Fri Aug 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 PM CDT
FOR WYANDOTTE...JOHNSON...NORTHWESTERN CASS...SOUTHWESTERN CLAY...
SOUTHEASTERN PLATTE AND WESTERN JACKSON COUNTIES...

At 1109 PM CDT, a severe thunderstorm was located near Raytown,
moving east at 50 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Kansas City, Overland Park, Olathe, Independence, Lee's Summit,
Shawnee, Lenexa, Leawood, Raytown, Liberty, Gladstone, Grandview,
Belton, Prairie Village, Raymore, Gardner, Merriam, Mission, Bonner
Springs and De Soto.

This includes the following highways...
 Interstate 70 in Missouri between mile markers 0 and 17.
 Interstate 70 in Kansas between mile markers 410 and 423.
 Interstate 35 in Missouri between mile markers 0 and 12.
 Interstate 35 in Kansas between mile markers 209 and 235.
 Interstate 29 between mile markers 0 and 6.
 Interstate 635 between mile markers 0 and 12.
 Interstate 470 between mile markers 0 and 9, and between mile
markers 13 and 16.
 Interstate 435 between mile markers 0 and 15, and between mile
markers 52 and 83.
 Kansas Turnpike near mile marker 226.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3900 9492 3898 9492 3899 9491 3902 9491
      3914 9483 3924 9459 3914 9428 3882 9443
      3877 9461 3880 9505
TIME...MOT...LOC 0409Z 289DEG 44KT 3903 9451 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Leighton
246 
WWUS53 KEAX 210428
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
1128 PM CDT Fri Aug 20 2021

KSC091-209-MOC037-047-095-165-210438-
/O.EXP.KEAX.SV.W.0126.000000T0000Z-210821T0430Z/
Wyandotte KS-Johnson KS-Cass MO-Clay MO-Platte MO-Jackson MO-
1128 PM CDT Fri Aug 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR WYANDOTTE...JOHNSON...
NORTHWESTERN CASS...SOUTHWESTERN CLAY...SOUTHEASTERN PLATTE AND
WESTERN JACKSON COUNTIES WILL EXPIRE AT 1130 PM CDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.  However small hail, gusty winds and heavy rain
are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
northeastern and east central Kansas...and west central Missouri.

LAT...LON 3900 9492 3898 9492 3899 9491 3902 9491
      3914 9483 3924 9459 3914 9428 3882 9443
      3877 9461 3880 9505
TIME...MOT...LOC 0428Z 289DEG 44KT 3897 9428 

$$

Leighton

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 7:39 PM CDTSevere Thunderstorm WarningEAXAtchison, Holt, Nodaway51 min
Aug 20, 8:10 PM CDTSevere Thunderstorm WarningEAXHolt20 min
Aug 20, 8:29 PM CDTSpecial Weather StatementEAXAndrew, Buchanan, Holt31 min
Aug 20, 8:31 PM CDTSevere Thunderstorm WarningEAXAndrew, Buchanan, Clinton, DeKalb, Gentry, Holt and 1 more44 min
Aug 20, 9:13 PM CDTSpecial Weather StatementEAXBuchanan, Platte47 min
Aug 20, 9:41 PM CDTSpecial Weather StatementEAXBuchanan, Caldwell, Clay, Clinton, Platte49 min
Aug 20, 10:11 PM CDTSpecial Weather StatementEAXClay, Jackson, Ray49 min
Aug 20, 11:18 PM CDTSpecial Weather StatementEAXBates, Cass, Johnson42 min
Aug 20, 11:39 PM CDTSpecial Weather StatementEAXCooper, Howard, Pettis, Saline51 min
Aug 21, 12:02 AM CDTSpecial Weather StatementEAXHenry, Pettis28 min
Aug 20, 10:29 PM CDTSpecial Weather StatementEAXAtchison46 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2021Severe Thunderstorm Warnings in Kansas, 2021Every 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.