Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 198, NWS St. Louis, MO

December 15, 20216 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Dec 15, 2021, 8:01 PM CST for 6 counties in Missouri. It was in force for 44 min. 2 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
Dec 15, 2021, 8:01 PM CST (02:01 UTC)
Expired
Dec 15, 2021, 8:45 PM CST
In force
44 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Damage threat
Considerable
Hail
0.75 in
Wind
70.0 mph

Counties Knox County, MO, Lewis County, MO, Marion County, MO, Monroe County, MO, Ralls County, MO, Shelby County, MO

The radar

The St Louis radar (KLSX), 164 km from the middle of the area, began a volume at 02:02 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

TimeReportWhereRemark
Dec 15, 8:27 PM CSTTSTM WND GST 471 Ene Novelty, MO
Dec 15, 8:41 PM CSTTSTM WND DMGLa Belle, MO1.5 FOOT DIAMETER TREE BLOWN DOWN.

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
Dec 15, 6:00 PM CSTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.0 hours before the alert went out and 219 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 2021-12-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 229 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 2021-12-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 433 square meters per square second.1939587897117Sfc1 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
229 J/kg
Mixed-layer CIN
-358 J/kg
Mixed-layer LCL
1061 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
433 m²/s²
0-3 km storm-relative helicity
496 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

878 
WUUS53 KLSX 160201
SVRLSX
MOC103-111-127-137-173-205-160245-
/O.NEW.KLSX.SV.W.0198.211216T0201Z-211216T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
801 PM CST Wed Dec 15 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Knox County in northeastern Missouri...
  Ralls County in northeastern Missouri...
  Marion County in northeastern Missouri...
  Shelby County in northeastern Missouri...
  Lewis County in northeastern Missouri...
  Monroe County in northeastern Missouri...

* Until 845 PM CST.

* At 800 PM CST, severe thunderstorms were located along a line
  extending from 7 miles southeast of Greentop to near Keytesville,
  moving east at 65 mph.

  HAZARD...70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Severe thunderstorms will be near...
  Greensburg around 810 PM CST.

Other locations in the path of these severe thunderstorms include
Madison, Woodlawn, Maud, Granville and Shelbina.

This also includes Wakonda State Park, 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 4030 9195 4026 9193 4025 9150 4003 9150
      3993 9142 3988 9145 3983 9142 3947 9143
      3945 9146 3932 9144 3935 9231 3995 9229
      3996 9234 4030 9235
TIME...MOT...LOC 0200Z 249DEG 56KT 4030 9244 3939 9288 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Elmore
3 follow-up statements
647 
WWUS53 KLSX 160223
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
823 PM CST Wed Dec 15 2021

MOC103-111-127-137-173-205-160245-
/O.CON.KLSX.SV.W.0198.000000T0000Z-211216T0245Z/
Knox MO-Ralls MO-Marion MO-Shelby MO-Lewis MO-Monroe MO-
823 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CST
FOR KNOX...RALLS...MARION...SHELBY...LEWIS AND MONROE COUNTIES...

At 823 PM CST, severe thunderstorms were located along a line
extending from near South Gorin to near Huntsville, moving northeast
at 105 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
  Clarence, Shelbyville, Plevna, Steffenville, La Belle, Lewistown 
  and Ewing.

This also includes Wakonda State Park, 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 4030 9195 4026 9193 4025 9150 4003 9150
      3993 9142 3988 9145 3983 9142 3947 9143
      3945 9146 3932 9144 3935 9231 3995 9229
      3996 9234 4030 9235
TIME...MOT...LOC 0223Z 224DEG 91KT 4040 9205 3952 9257 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Elmore
071 
WWUS53 KLSX 160228
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
828 PM CST Wed Dec 15 2021

MOC103-111-127-137-173-205-160245-
/O.CON.KLSX.SV.W.0198.000000T0000Z-211216T0245Z/
Knox MO-Ralls MO-Marion MO-Shelby MO-Lewis MO-Monroe MO-
828 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CST
FOR KNOX...RALLS...MARION...SHELBY...LEWIS AND MONROE COUNTIES...

At 827 PM CST, a severe thunderstorm was located near Plevna, moving
northeast at 65 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Hannibal, Palmyra, Monroe City, Canton, Shelbina, Paris, Edina, Santa
Fe, Warren, La Grange, Clarence, Perry, La Belle, Madison,
Shelbyville, Lewistown, Center, Ewing, Rensselaer and Knox City.

This also includes Wakonda State Park, 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 4030 9195 4026 9193 4025 9150 4003 9150
      3993 9142 3988 9145 3983 9142 3947 9143
      3945 9146 3932 9144 3935 9231 3995 9229
      3996 9234 4030 9235
TIME...MOT...LOC 0227Z 239DEG 56KT 4005 9215 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Elmore
818 
WWUS53 KLSX 160243
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
843 PM CST Wed Dec 15 2021

MOC103-111-127-137-173-205-160253-
/O.EXP.KLSX.SV.W.0198.000000T0000Z-211216T0245Z/
Knox MO-Ralls MO-Marion MO-Shelby MO-Lewis MO-Monroe MO-
843 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR KNOX...RALLS...MARION...
SHELBY...LEWIS AND MONROE COUNTIES WILL EXPIRE AT 845 PM CST...
                
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 gusty
winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until midnight CST for
west central Illinois...and central and northeastern Missouri.

Remember, a Severe Thunderstorm Warning still remains in effect for
Monroe and Ralls counties. 

LAT...LON 4030 9195 4026 9193 4025 9150 4003 9150
      3993 9142 3988 9145 3983 9142 3947 9143
      3945 9146 3932 9144 3935 9231 3995 9229
      3996 9234 4030 9235
TIME...MOT...LOC 0243Z 270DEG 56KT 4013 9188 

$$

Elmore

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 15, 8:34 PM CSTSevere Thunderstorm WarningLSXAudrain, Boone, Callaway, Moniteau, Monroe, Ralls41 min
Dec 15, 9:09 PM CSTSevere Thunderstorm WarningLSXAudrain, Boone, Callaway, Cole, Marion, Monroe and 3 more51 min
Dec 15, 9:22 PM CSTSevere Thunderstorm WarningLSXMarion53 min
Dec 15, 9:48 PM CSTSevere Thunderstorm WarningLSXAudrain, Callaway, Lincoln, Montgomery, Pike, Ralls42 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.