Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 80, NWS St. Louis, MO

June 20, 2021Knox County, Lewis County, Shelby County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 20, 2021, 8:41 PM CDT for Knox County, Lewis County, Shelby County, Missouri. It was in force for 49 min. 5 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
Jun 20, 2021, 8:41 PM CDT (01:41 UTC)
Expired
Jun 20, 2021, 9:30 PM CDT
In force
49 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

Counties Knox County, MO, Lewis County, MO, Shelby County, MO

The radar

The St Louis radar (KLSX), 176 km from the middle of the area, began a volume at 01:41 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
Jun 20, 9:15 PM CDTTSTM WND DMGShelbyville, MOTREES CAME DOWN ON A HOUSE AND VEHICLE. TIME ESTIMATED FROM RADAR.
Jun 20, 9:15 PM CDTTSTM WND GST 661 Nne Bethel, MOVIA FACEBOOK.
Jun 20, 9:20 PM CDTTSTM WND DMG2 S Shelbyville, MOTREES DOWN OVER HIGHWAY 15 SOUTH OF SHELBYVILLE.
Jun 20, 9:20 PM CDTTSTM WND DMG4 Ene Maud, MOA BARN ROOF WAS TORN OFF AND THE BARN DOOR WAS BLOWN A QUARTER OF A MILE TO THE SOUTH (INTO MONROE COUNTY). ALSO, AN EMPTY SEMI TRAILER WAS BLOWN OVER ON TOP OF A PICKUP TRUCK. THE HOUSE LOST A NUMBER OF SHINGLES.
Jun 20, 9:24 PM CDTTSTM WND DMGLewistown, MOSIX INCH DIAMETER TREE LIMBS DOWNED. TIME ESTIMATED FROM RADAR.

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
Jun 20, 8:10 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.7 hours before the alert went out and 232 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, Davenport, at 00:00Z on 2021-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1058 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, Davenport, at 00:00Z on 2021-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 174 square meters per square second.19395878Sfc1 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
1058 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
1009 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
174 m²/s²
0-3 km storm-relative helicity
230 m²/s²
Significant tornado parameter
1.4
Supercell composite
7.8

Open this sounding in Storm Lab

The text

As transmitted.

622 
WUUS53 KLSX 210141
SVRLSX
MOC103-111-205-210230-
/O.NEW.KLSX.SV.W.0080.210621T0141Z-210621T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
841 PM CDT Sun Jun 20 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Knox County in northeastern Missouri...
  Shelby County in northeastern Missouri...
  Southwestern Lewis County in northeastern Missouri...

* Until 930 PM CDT.

* At 840 PM CDT, severe thunderstorms were located along a line
  extending from near Edina to 6 miles south of Marceline, moving
  southeast at 45 mph.

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

  SOURCE...Trained weather spotters. At 8:32 pm, a 71 mph wind gust 
           was measured at Kirksville Regional Airport.

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Severe thunderstorms will be near...
  Edina around 845 PM CDT.
  Knox City around 850 PM CDT.
  La Belle around 900 PM CDT.

Other locations in the path of these severe thunderstorms include
Lewistown and Ewing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4009 9162 3995 9179 3995 9184 3990 9184
      3966 9211 3966 9219 3960 9219 3961 9230
      3995 9229 3996 9234 4021 9235
TIME...MOT...LOC 0140Z 293DEG 38KT 4021 9211 3962 9293 

HAIL...1.00IN
WIND...70MPH
 
$$

19
2 follow-up statements
210 
WWUS53 KLSX 210154
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
854 PM CDT Sun Jun 20 2021

MOC103-111-205-210230-
/O.CON.KLSX.SV.W.0080.000000T0000Z-210621T0230Z/
Knox MO-Shelby MO-Lewis MO-
854 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM CDT
FOR SOUTHEASTERN KNOX...SHELBY AND SOUTHWESTERN LEWIS COUNTIES...

At 854 PM CDT, severe thunderstorms were located along a line
extending from La Belle to 9 miles northeast of Salisbury, moving
east at 50 mph.

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

SOURCE...Trained weather spotters. At 8:32 pm, a 71 mph wind gust 
         was measured at Kirksville Regional Airport.

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

These severe storms will be near...
  La Belle and Lewistown around 900 PM CDT.

Other locations in the path of these severe thunderstorms include
Ewing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3991 9229 4014 9195 4009 9162 3995 9179
      3995 9184 3990 9184 3966 9211 3966 9219
      3960 9219 3961 9230
TIME...MOT...LOC 0154Z 288DEG 44KT 4013 9191 3955 9273 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

19
409 
WWUS53 KLSX 210204
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
904 PM CDT Sun Jun 20 2021

MOC103-111-205-210230-
/O.CON.KLSX.SV.W.0080.000000T0000Z-210621T0230Z/
Knox MO-Shelby MO-Lewis MO-
904 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM CDT
FOR SOUTHEASTERN KNOX...SHELBY AND SOUTHWESTERN LEWIS COUNTIES...

At 903 PM CDT, severe thunderstorms were located along a line
extending from near Lewistown to near Huntsville, moving east at 50
mph.

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

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

These severe thunderstorms will remain over mainly rural areas of
southeastern Knox, Shelby and southwestern Lewis Counties, including
the following locations... Leonard, Newark and Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4008 9204 4000 9173 3995 9179 3995 9184
      3990 9184 3966 9211 3966 9219 3960 9219
      3961 9230 3991 9229
TIME...MOT...LOC 0203Z 288DEG 43KT 4009 9176 3951 9258 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

19

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 9:07 PM CDTTornado WarningLSXMarion, Shelby38 min
Jun 20, 9:17 PM CDTSevere Thunderstorm WarningLSXKnox, Lewis, Marion, Monroe, Ralls, Shelby43 min
Jun 20, 9:42 PM CDTSevere Thunderstorm WarningLSXAudrain, Boone, Monroe48 min
Jun 20, 9:59 PM CDTSevere Thunderstorm WarningLSXMarion, Monroe, Pike, Ralls46 min
Jun 20, 10:10 PM CDTSevere Thunderstorm WarningLSXAudrain, Boone, Monroe, Montgomery, Pike, Ralls50 min
Jun 20, 10:22 PM CDTSevere Thunderstorm WarningLSXAudrain, Boone, Callaway38 min
Jun 20, 10:27 PM CDTAreal Flood AdvisoryLSXAudrain, Boone, Monroe3 hr
Jun 20, 10:42 PM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole, Moniteau48 min
Jun 20, 10:55 PM CDTSevere Thunderstorm WarningLSXAudrain, Boone, Callaway, Montgomery35 min
Jun 20, 11:29 PM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole, Franklin, Gasconade, Lincoln and 3 more31 min
Jun 20, 11:41 PM CDTSevere Thunderstorm WarningLSXLincoln, Saint Charles19 min
Jun 20, 11:59 PM CDTSevere Thunderstorm WarningLSXFranklin, Gasconade, Montgomery, Osage, Warren31 min
Jun 21, 12:34 AM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole, Moniteau26 min

Nearby

Severe Thunderstorm Warnings in Missouri, 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.