Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 98, NWS Kansas City, MO

August 11, 2021Linn County, Macon County, Missouri

NWS Kansas City, MO issued this severe thunderstorm warning at Aug 11, 2021, 4:59 AM CDT for Linn County, Macon County, Missouri. It was in force for 46 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 11, 2021, 4:59 AM CDT (09:59 UTC)
Expired: Aug 11, 2021, 5:45 AM CDT
In force: 46 min
Issued by: NWS Kansas City, MO
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Linn County, MO, Macon County, MO

The radar

The Pleasant Hill radar (KEAX), 187 km from the middle of the area, began a volume at 10:02 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 11, 5:34 AM CDT	HAIL 1	2 W Ethel, MO	SPOTTER REPORTED IT HAILED ON AND OFF FOR 45 MINUTES, MAINLY HALF INCH TO THREE QUARTERS OF AN INCH, WITH SEVERAL QUARTER SIZE MIXED IN.

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

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 10.0 hours before the alert went out and 260 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: 856 J/kg
Mixed-layer CIN: -155 J/kg
Mixed-layer LCL: 940 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 77 m²/s²
0-3 km storm-relative helicity: 160 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -1.4

Open this sounding in Storm Lab

The text

As transmitted.

186 
WUUS53 KEAX 110959
SVREAX
MOC115-121-111045-
/O.NEW.KEAX.SV.W.0098.210811T0959Z-210811T1045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Kansas City/Pleasant Hill MO
459 AM CDT Wed Aug 11 2021

The National Weather Service in Pleasant Hill has issued a

* Severe Thunderstorm Warning for...
  East central Linn County in north central Missouri...
  Northwestern Macon County in north central Missouri...

* Until 545 AM CDT.

* At 458 AM CDT, severe thunderstorms were located along a line
  extending from 15 miles west of La Plata to 13 miles northeast of
  Marceline to near Bucklin, moving east at 20 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Elmer, Ethel and New Boston. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3997 9254 3983 9264 3980 9305 4000 9282
      4004 9256 4004 9252
TIME...MOT...LOC 0958Z 249DEG 17KT 3997 9277 3990 9285 3984 9293 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Kurtz

4 follow-up statements

463 
WWUS53 KEAX 111007
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
507 AM CDT Wed Aug 11 2021

MOC115-121-111045-
/O.CON.KEAX.SV.W.0098.000000T0000Z-210811T1045Z/
Linn MO-Macon MO-
507 AM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
FOR EAST CENTRAL LINN AND NORTHWESTERN MACON COUNTIES...

At 507 AM CDT, severe thunderstorms were located along a line
extending from 13 miles west of La Plata to 13 miles northwest of
Callao to near Bucklin, moving east at 15 mph.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Elmer and Ethel. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

These storms are producing large hail. SEEK SHELTER NOW inside a
sturdy structure and stay away from windows.

&&

LAT...LON 3997 9254 3983 9264 3983 9297 3999 9279
      4004 9256 4004 9252
TIME...MOT...LOC 1007Z 257DEG 15KT 3998 9273 3990 9282 3985 9289 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Kurtz

541 
WWUS53 KEAX 111016
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
516 AM CDT Wed Aug 11 2021

MOC115-121-111045-
/O.CON.KEAX.SV.W.0098.000000T0000Z-210811T1045Z/
Linn MO-Macon MO-
516 AM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
FOR EAST CENTRAL LINN AND NORTHWESTERN MACON COUNTIES...

At 516 AM CDT, a severe thunderstorm was located 10 miles northeast
of Bucklin, or 16 miles northeast of Marceline, moving east 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...
Elmer and Ethel. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3997 9254 3983 9264 3984 9296 3985 9295
      3991 9285 3998 9278 4004 9256 4004 9252
TIME...MOT...LOC 1016Z 259DEG 18KT 3991 9276 

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

$$

Kurtz

896 
WWUS53 KEAX 111034
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
534 AM CDT Wed Aug 11 2021

MOC115-111044-
/O.CAN.KEAX.SV.W.0098.000000T0000Z-210811T1045Z/
Linn MO-
534 AM CDT Wed Aug 11 2021

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

LAT...LON 3997 9254 3983 9264 3984 9283 3991 9283
      3997 9274 4000 9253
TIME...MOT...LOC 1034Z 255DEG 16KT 3989 9276 

$$

MOC121-111045-
/O.CON.KEAX.SV.W.0098.000000T0000Z-210811T1045Z/
Macon MO-
534 AM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
FOR NORTHWESTERN MACON COUNTY...

At 534 AM CDT, a severe thunderstorm was located 9 miles northeast of
Bucklin, or 15 miles northeast of Marceline, moving east 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...
Elmer and Ethel. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3997 9254 3983 9264 3984 9283 3991 9283
      3997 9274 4000 9253
TIME...MOT...LOC 1034Z 255DEG 16KT 3989 9276 

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

$$

Kurtz

804 
WWUS53 KEAX 111042
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
542 AM CDT Wed Aug 11 2021

MOC121-111052-
/O.EXP.KEAX.SV.W.0098.000000T0000Z-210811T1045Z/
Macon MO-
542 AM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN MACON COUNTY WILL
EXPIRE AT 545 AM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small
hail, gusty winds and heavy rain are still possible with this
thunderstorm.

LAT...LON 3997 9254 3983 9264 3984 9283 3991 9283
      3997 9274 4000 9253
TIME...MOT...LOC 1042Z 249DEG 17KT 3990 9273 

$$

Kurtz

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 4:22 AM CDT	Special Weather Statement	EAX	Linn	38 min
Aug 11, 4:49 AM CDT	Special Weather Statement	EAX	Macon	41 min
Aug 11, 5:41 AM CDT	Special Weather Statement	EAX	Macon	49 min
Aug 11, 6:12 AM CDT	Special Weather Statement	EAX	Adair	18 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.