Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 123, NWS Kansas City, MO

August 20, 2021Atchison County, Holt County, Nodaway County, Missouri

NWS Kansas City, MO issued this severe thunderstorm warning at Aug 20, 2021, 7:39 PM CDT for Atchison County, Holt County, Nodaway County, Missouri. It was in force for 51 min. 1 report 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, 7:39 PM CDT (00:39 UTC)
Expired: Aug 20, 2021, 8:30 PM CDT
In force: 51 min
Issued by: NWS Kansas City, MO
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Atchison County, MO, Holt County, MO, Nodaway County, MO

The radar

The Omaha radar (KOAX), 150 km from the middle of the area, began a volume at 00:40 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 20, 8:18 PM CDT	TSTM WND DMG	Mound City, MO	TREE DOWN ACROSS ROAD IN MOUND CITY. TRAFFIC BEING REROUTED.

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 00:00Z, 0.7 hours before the alert went out and 138 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: 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.

989 
WUUS53 KEAX 210039
SVREAX
MOC005-087-147-210130-
/O.NEW.KEAX.SV.W.0123.210821T0039Z-210821T0130Z/

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

The National Weather Service in Pleasant Hill has issued a

* Severe Thunderstorm Warning for...
  Atchison County in northwestern Missouri...
  Holt County in northwestern Missouri...
  Southwestern Nodaway County in northwestern Missouri...

* Until 830 PM CDT.

* At 739 PM CDT, severe thunderstorms were located along a line
  extending from near Johnson to near Humboldt to near Bern, moving
  east at 55 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Tarkio, Mound City, Rock Port, Oregon, Fairfax, Maitland, Skidmore,
  Forest City, Craig, White Cloud, Graham, Big Lake, Quitman,
  Fortescue, Bigelow, Corning, Phelps City and Indian Cave State
  Park.

This includes Interstate 29 between mile markers 71 and 115.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4034 9504 4013 9503 4007 9506 4004 9503
      4000 9503 3998 9530 4001 9532 4004 9542
      4012 9539 4018 9548 4024 9547 4026 9555
      4030 9556 4031 9566 4034 9562 4041 9566
      4046 9564 4054 9516
TIME...MOT...LOC 0039Z 257DEG 47KT 4045 9592 4020 9587 4000 9604 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Leighton

2 follow-up statements

244 
WWUS53 KEAX 210051
SVSEAX

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

MOC005-087-147-210130-
/O.CON.KEAX.SV.W.0123.000000T0000Z-210821T0130Z/
Atchison MO-Holt MO-Nodaway MO-
751 PM CDT Fri Aug 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM CDT
FOR ATCHISON...HOLT AND SOUTHWESTERN NODAWAY COUNTIES...

At 750 PM CDT, severe thunderstorms were located along a line
extending from Peru to Shubert to 6 miles northeast of Bern, moving
east at 45 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Tarkio, Mound City, Rock Port, Oregon, Fairfax, Maitland, Skidmore,
Forest City, Craig, White Cloud, Graham, Big Lake, Quitman,
Fortescue, Bigelow, Corning, Phelps City and Indian Cave State Park.

This includes Interstate 29 between mile markers 71 and 114.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4013 9503 4007 9506 4004 9503 4000 9503
      3998 9530 4001 9532 4004 9542 4012 9539
      4018 9548 4024 9547 4026 9555 4030 9556
      4031 9566 4034 9562 4041 9566 4046 9564
      4048 9512 4034 9504
TIME...MOT...LOC 0050Z 266DEG 39KT 4047 9575 4022 9570 4002 9587 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Leighton

550 
WWUS53 KEAX 210111
SVSEAX

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

MOC005-087-147-210130-
/O.CON.KEAX.SV.W.0123.000000T0000Z-210821T0130Z/
Atchison MO-Holt MO-Nodaway MO-
811 PM CDT Fri Aug 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM CDT
FOR SOUTHEASTERN ATCHISON...HOLT AND SOUTHWESTERN NODAWAY COUNTIES...

At 811 PM CDT, severe thunderstorms were located along a line
extending from 6 miles north of Tarkio to near Fairfax to near Falls
City, moving east at 55 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Mound City, Oregon, Fairfax, Maitland, Skidmore, Forest City, Craig,
White Cloud, Graham, Big Lake, Quitman, Fortescue, Bigelow, Corning
and Indian Cave State Park.

This includes Interstate 29 between mile markers 71 and 106.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4013 9503 4007 9506 4004 9503 4000 9503
      3998 9530 4001 9532 4004 9542 4012 9539
      4018 9548 4024 9547 4026 9555 4030 9556
      4031 9566 4034 9562 4039 9507 4034 9504
TIME...MOT...LOC 0111Z 257DEG 47KT 4053 9541 4028 9536 4008 9553 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Leighton

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 8:10 PM CDT	Severe Thunderstorm Warning	EAX	Holt	20 min
Aug 20, 8:29 PM CDT	Special Weather Statement	EAX	Andrew, Buchanan, Holt	31 min
Aug 20, 8:31 PM CDT	Severe Thunderstorm Warning	EAX	Andrew, Buchanan, Clinton, DeKalb, Gentry, Holt and 1 more	44 min
Aug 20, 9:13 PM CDT	Special Weather Statement	EAX	Buchanan, Platte	47 min
Aug 20, 9:41 PM CDT	Special Weather Statement	EAX	Buchanan, Caldwell, Clay, Clinton, Platte	49 min
Aug 20, 10:11 PM CDT	Special Weather Statement	EAX	Clay, Jackson, Ray	49 min
Aug 20, 10:44 PM CDT	Severe Thunderstorm Warning	EAX	Cass, Clay, Jackson, Platte	46 min
Aug 20, 11:18 PM CDT	Special Weather Statement	EAX	Bates, Cass, Johnson	42 min
Aug 20, 11:39 PM CDT	Special Weather Statement	EAX	Cooper, Howard, Pettis, Saline	51 min
Aug 21, 12:02 AM CDT	Special Weather Statement	EAX	Henry, Pettis	28 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.