Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 142, NWS St. Louis, MO

August 12, 20214 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 12, 2021, 3:58 PM CDT for 4 counties in Missouri. It was in force for 62 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
Aug 12, 2021, 3:58 PM CDT (20:58 UTC)
Expired
Aug 12, 2021, 5:00 PM CDT
In force
62 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Audrain County, MO, Boone County, MO, Monroe County, MO, Shelby County, MO

The radar

The St Louis radar (KLSX), 147 km from the middle of the area, began a volume at 20:57 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 12, 4:36 PM CDTTSTM WND DMGMexico, MOTREE LIMBS DOWN ACROSS ROAD.
Aug 12, 4:55 PM CDTTSTM WND GST 611 E Vandiver, MOMEASURED KMYJ AWOS.
Aug 12, 4:55 PM CDTTSTM WND GST 612 E Vandiver, MO

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 12:00Z, 9.0 hours before the alert went out and 281 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 12:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2463 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

114 
WUUS53 KLSX 122058
SVRLSX
MOC007-019-137-205-122200-
/O.NEW.KLSX.SV.W.0142.210812T2058Z-210812T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
358 PM CDT Thu Aug 12 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Northeastern Boone County in central Missouri...
  Central Audrain County in central Missouri...
  Southern Shelby County in northeastern Missouri...
  Monroe County in northeastern Missouri...

* Until 500 PM CDT.

* At 358 PM CDT, a severe thunderstorm was located near Cairo, moving
  east at 30 mph.

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

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Woodlawn around 410 PM CDT.
  Madison around 415 PM CDT.

Other locations in the path of this severe thunderstorm include
Granville, Paris and Santa Fe.

This also includes Union Covered Bridge Historic Site and Mark Twain
Lake Recreational Area.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3925 9243 3925 9231 3970 9229 3970 9185
      3966 9184 3965 9171 3906 9173 3922 9244
TIME...MOT...LOC 2058Z 282DEG 25KT 3949 9236 

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

$$

Elmore
3 follow-up statements
168 
WWUS53 KLSX 122111
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
411 PM CDT Thu Aug 12 2021

MOC007-019-137-205-122200-
/O.CON.KLSX.SV.W.0142.000000T0000Z-210812T2200Z/
Boone MO-Audrain MO-Shelby MO-Monroe MO-
411 PM CDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR NORTHEASTERN BOONE...CENTRAL AUDRAIN...SOUTHERN SHELBY AND MONROE
COUNTIES...

At 410 PM CDT, a severe thunderstorm was located over Madison, moving
east at 30 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
  Granville, Paris and Santa Fe.

This also includes Union Covered Bridge Historic Site and Mark Twain
Lake Recreational Area.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3925 9243 3925 9231 3970 9229 3970 9185
      3966 9184 3965 9171 3906 9173 3922 9244
TIME...MOT...LOC 2110Z 282DEG 25KT 3947 9225 

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

$$

Elmore
092 
WWUS53 KLSX 122140
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
440 PM CDT Thu Aug 12 2021

MOC007-019-137-205-122200-
/O.CON.KLSX.SV.W.0142.000000T0000Z-210812T2200Z/
Boone MO-Audrain MO-Shelby MO-Monroe MO-
440 PM CDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR NORTHEASTERN BOONE...CENTRAL AUDRAIN...SOUTHEASTERN SHELBY AND
MONROE COUNTIES...

At 440 PM CDT, a severe thunderstorm was located near Paris, moving
east at 30 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Mexico, Centralia, Monroe City, Shelbina, Paris, Santa Fe, Granville,
Hunnewell, Rush Hill, Benton City, Vandiver, Stoutsville, Florida,
Indian Creek and Thompson.

This also includes Union Covered Bridge Historic Site and Mark Twain
Lake Recreational Area.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3924 9216 3970 9209 3970 9185 3966 9184
      3965 9171 3906 9173 3916 9217
TIME...MOT...LOC 2140Z 282DEG 25KT 3943 9199 

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

$$

Elmore
112 
WWUS53 KLSX 122156
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
456 PM CDT Thu Aug 12 2021

MOC007-019-137-205-122206-
/O.EXP.KLSX.SV.W.0142.000000T0000Z-210812T2200Z/
Boone MO-Audrain MO-Shelby MO-Monroe MO-
456 PM CDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BOONE...CENTRAL
AUDRAIN...SOUTHEASTERN SHELBY AND MONROE COUNTIES WILL EXPIRE AT 500
PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 3924 9216 3970 9209 3970 9185 3966 9184
      3965 9171 3906 9173 3916 9217
TIME...MOT...LOC 2156Z 282DEG 25KT 3941 9186 

$$

Elmore

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 4:45 PM CDTSevere Thunderstorm WarningLSXMarion, Pike, Ralls45 min
Aug 12, 4:50 PM CDTSevere Thunderstorm WarningLSXAudrain, Callaway, Lincoln, Monroe, Montgomery, Pike and 1 more40 min
Aug 12, 4:56 PM CDTAreal Flood AdvisoryLSXLewis, Marion4 hr
Aug 12, 5:27 PM CDTSevere Thunderstorm WarningLSXAudrain, Lincoln, Montgomery, Pike, Warren48 min
Aug 12, 5:51 PM CDTSevere Thunderstorm WarningLSXFranklin, Gasconade, Jefferson, Lincoln, Saint Charles, Saint Louis and 1 more54 min
Aug 12, 6:37 PM CDTSevere Thunderstorm WarningLSXFranklin, Jefferson, Saint Charles, Saint Louis, City of Saint Louis53 min
Aug 12, 6:41 PM CDTAreal Flood AdvisoryLSXLincoln, Saint Charles, Saint Louis4 hr

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.