Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 84, NWS St. Louis, MO

June 20, 20216 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 20, 2021, 10:10 PM CDT for 6 counties in Missouri. It was in force for 50 min. 3 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, 10:10 PM CDT (03:10 UTC)
Expired
Jun 20, 2021, 11:00 PM CDT
In force
50 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

Counties Audrain County, MO, Boone County, MO, Monroe County, MO, Montgomery County, MO, Pike County, MO, Ralls County, MO

The radar

The St Louis radar (KLSX), 105 km from the middle of the area, began a volume at 03:13 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, 10:11 PM CDTTSTM WND DMG1 Nw Mexico, MOLARGE TREE DOWN ACROSS JACKSON STREET IN CENTRAL MEXICO.
Jun 20, 10:11 PM CDTTSTM WND DMGMexico, MONUMEROUS TREE LIMBS DOWN IN/AROUND MEXICO. ONE LARGE LIMB FELL ON A PARKED CAR IN 800 BLOCK OF EAST JACKSON. METAL STORAGE SHED BLOWN ONTO NEARBY ROADWAY NEAR HOLT STREET AND MARTIN LUTHER KING DRIVE.
Jun 20, 10:22 PM CDTTSTM WND DMGLaddonia, MOLARGE TREE (GREATER THAN TWO FT DIA) BROKEN INTO POWER LINES.

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

Lincoln, IL (KILX), launched 00:00Z, 3.2 hours before the alert went out and 289 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, Lincoln, IL at 00:00Z on 2021-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1632 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, Lincoln, IL at 00:00Z on 2021-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 159 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
1632 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
1351 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
159 m²/s²
0-3 km storm-relative helicity
421 m²/s²
Significant tornado parameter
0.9
Supercell composite
13.7

Open this sounding in Storm Lab

The text

As transmitted.

438 
WUUS53 KLSX 210310
SVRLSX
MOC007-019-137-139-163-173-210400-
/O.NEW.KLSX.SV.W.0084.210621T0310Z-210621T0400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
1010 PM CDT Sun Jun 20 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Southwestern Ralls County in northeastern Missouri...
  Northeastern Boone County in central Missouri...
  Audrain County in central Missouri...
  Northern Montgomery County in east central Missouri...
  Southeastern Monroe County in northeastern Missouri...
  Southwestern Pike County in northeastern Missouri...

* Until 1100 PM CDT.

* At 1010 PM CDT, severe thunderstorms were located along a line
  extending from Vandalia to near Mexico, 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.

* Severe thunderstorms will be near...
  Vandalia and Farber around 1015 PM CDT.
  Martinsburg and New Hartford around 1025 PM CDT.
  Wellsville around 1030 PM CDT.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3942 9198 3927 9115 3900 9138 3903 9164
      3906 9164 3906 9186 3912 9224
TIME...MOT...LOC 0310Z 288DEG 45KT 3932 9150 3914 9189 

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

19
1 follow-up statement
944 
WWUS53 KLSX 210336
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1036 PM CDT Sun Jun 20 2021

MOC137-210345-
/O.CAN.KLSX.SV.W.0084.000000T0000Z-210621T0400Z/
Monroe MO-
1036 PM CDT Sun Jun 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MONROE COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 100 AM CDT for
central, northeastern and east central Missouri.

LAT...LON 3924 9214 3934 9182 3934 9172 3937 9172
      3927 9115 3900 9138 3903 9164 3906 9164
      3906 9186 3912 9224
TIME...MOT...LOC 0335Z 288DEG 45KT 3922 9112 3904 9151 

$$

MOC007-019-139-163-173-210400-
/O.CON.KLSX.SV.W.0084.000000T0000Z-210621T0400Z/
Ralls MO-Boone MO-Audrain MO-Montgomery MO-Pike MO-
1036 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1100 PM CDT
FOR SOUTHWESTERN RALLS COUNTY IN NORTHEASTERN MISSOURI...NORTHEASTERN
BOONE AND AUDRAIN COUNTIES IN CENTRAL MISSOURI...NORTHERN MONTGOMERY
COUNTY IN EAST CENTRAL MISSOURI AND SOUTHWESTERN PIKE COUNTIES IN
NORTHEASTERN MISSOURI...

At 1035 PM CDT, severe thunderstorms were located along a line
extending from near Eolia to near Buell, 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
southwestern Ralls County in northeastern Missouri, northeastern
Boone and Audrain Counties in central Missouri, northern Montgomery
County in east central Missouri and southwestern Pike Counties in
northeastern Missouri, including the following locations... Benton
City, Middletown, Vandiver, Ashley, Thompson and Rush Hill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3924 9214 3934 9182 3934 9172 3937 9172
      3927 9115 3900 9138 3903 9164 3906 9164
      3906 9186 3912 9224
TIME...MOT...LOC 0335Z 288DEG 45KT 3922 9112 3904 9151 

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, 8:41 PM CDTSevere Thunderstorm WarningLSXKnox, Lewis, Shelby49 min
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, 10:22 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.