Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 23, NWS St. Louis, MO

April 7, 20215 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 7, 2021, 4:04 PM CDT for 5 counties in Missouri. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 7, 2021, 4:04 PM CDT (21:04 UTC)
Expired
Apr 7, 2021, 4:30 PM CDT
In force
26 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Boone County, MO, Callaway County, MO, Cole County, MO, Moniteau County, MO, Osage County, MO

The radar

The St Louis radar (KLSX), 141 km from the middle of the area, began a volume at 21:05 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 7, 12:02 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 9.1 hours before the alert went out and 218 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, Springfield, MO at 12:00Z on 2021-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 790 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 12:00Z on 2021-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 186 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
790 J/kg
Mixed-layer CIN
-275 J/kg
Mixed-layer LCL
767 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
186 m²/s²
0-3 km storm-relative helicity
223 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

329 
WUUS53 KLSX 072104
SVRLSX
MOC019-027-051-135-151-072130-
/O.NEW.KLSX.SV.W.0023.210407T2104Z-210407T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
404 PM CDT Wed Apr 7 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Cole County in central Missouri...
  Southeastern Boone County in central Missouri...
  Southwestern Callaway County in central Missouri...
  Southwestern Osage County in central Missouri...
  Southeastern Moniteau County in central Missouri...

* Until 430 PM CDT.

* At 404 PM CDT, severe thunderstorms were located along a line
  extending from near Russellville to 7 miles southwest of St.
  Thomas, moving north at 70 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Jefferson City, Ashland, Holts Summit, Columbia Regional Airport,
  Wardsville, St. Martins, Taos, Russellville, New Bloomfield, Lake
  Mykee Town, Centertown, St. Thomas, Easley, McGirk, Hickory Hill,
  Brazito, Lake Mykee, Marion, Meta and Lohman.

This also includes Clarks Hill/Norton Historic Site and Jefferson
Landing Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3885 9238 3868 9189 3829 9213 3829 9219
      3834 9220 3834 9222 3832 9224 3832 9226
      3834 9229 3834 9241 3843 9241 3843 9258
TIME...MOT...LOC 2104Z 192DEG 61KT 3851 9247 3828 9229 

HAIL...0.88IN
WIND...60MPH
 
$$

MRM
3 follow-up statements
086 
WWUS53 KLSX 072114
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
414 PM CDT Wed Apr 7 2021

MOC019-027-051-135-151-072130-
/O.CON.KLSX.SV.W.0023.000000T0000Z-210407T2130Z/
Cole MO-Boone MO-Callaway MO-Osage MO-Moniteau MO-
414 PM CDT Wed Apr 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM CDT
FOR COLE...SOUTHEASTERN BOONE...SOUTHWESTERN CALLAWAY...SOUTHWESTERN
OSAGE AND SOUTHEASTERN MONITEAU COUNTIES...

At 414 PM CDT, severe thunderstorms were located along a line
extending from near Centertown to near St. Thomas, moving east at 70
mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Jefferson City, Ashland, Holts Summit, Columbia Regional Airport,
Wardsville, St. Martins, Taos, Russellville, New Bloomfield, Lake
Mykee Town, Centertown, St. Thomas, Easley, McGirk, Hickory Hill,
Brazito, Lake Mykee, Marion, Meta and Lohman.

This also includes Clarks Hill/Norton Historic Site and Jefferson
Landing Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3885 9238 3868 9189 3829 9213 3829 9219
      3834 9220 3834 9222 3832 9224 3832 9226
      3834 9229 3834 9241 3843 9241 3843 9258
TIME...MOT...LOC 2114Z 270DEG 61KT 3865 9240 3842 9222 

HAIL...0.88IN
WIND...60MPH
 
$$

MRM
716 
WWUS53 KLSX 072122
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
422 PM CDT Wed Apr 7 2021

MOC019-027-051-135-151-072130-
/O.CON.KLSX.SV.W.0023.000000T0000Z-210407T2130Z/
Cole MO-Boone MO-Callaway MO-Osage MO-Moniteau MO-
422 PM CDT Wed Apr 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM CDT
FOR COLE...SOUTHEASTERN BOONE...SOUTHWESTERN CALLAWAY...SOUTHWESTERN
OSAGE AND SOUTHEASTERN MONITEAU COUNTIES...

At 422 PM CDT, a severe thunderstorm was located over St. Thomas,
moving north at 75 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Jefferson City, Ashland, Holts Summit, Columbia Regional Airport,
Wardsville, St. Martins, Taos, Russellville, New Bloomfield, Lake
Mykee Town, Centertown, St. Thomas, Easley, McGirk, Hickory Hill,
Brazito, Lake Mykee, Marion, Meta and Lohman.

This also includes Clarks Hill/Norton Historic Site and Jefferson
Landing Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3885 9238 3868 9189 3829 9213 3829 9219
      3834 9220 3834 9222 3832 9224 3832 9226
      3834 9229 3834 9241 3843 9241 3843 9258
TIME...MOT...LOC 2122Z 198DEG 65KT 3840 9219 

TORNADO...POSSIBLE
HAIL...0.88IN
WIND...60MPH
 
$$

MRM
946 
WWUS53 KLSX 072131
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
431 PM CDT Wed Apr 7 2021

MOC019-027-051-135-151-072141-
/O.EXP.KLSX.SV.W.0023.000000T0000Z-210407T2130Z/
Cole MO-Boone MO-Callaway MO-Osage MO-Moniteau MO-
431 PM CDT Wed Apr 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR COLE...SOUTHEASTERN BOONE...
SOUTHWESTERN CALLAWAY...SOUTHWESTERN OSAGE AND SOUTHEASTERN MONITEAU
COUNTIES HAS EXPIRED...
                
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 has been allowed to expire.

A Severe Thunderstorm Watch remains in effect until 700 PM CDT for
central Missouri.

LAT...LON 3885 9238 3868 9189 3829 9213 3829 9219
      3834 9220 3834 9222 3832 9224 3832 9226
      3834 9229 3834 9241 3843 9241 3843 9258
TIME...MOT...LOC 2131Z 192DEG 61KT 3854 9215 

$$

MRM

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 7, 3:06 PM CDTSevere Thunderstorm WarningLSXMoniteau39 min
Apr 7, 4:27 PM CDTAreal Flood AdvisoryLSXBoone, Cole, Moniteau3 hr
Apr 7, 5:09 PM CDTSevere Thunderstorm WarningLSXKnox, Lewis, Marion, Monroe, Ralls, Shelby19 min
Apr 7, 5:37 PM CDTSevere Thunderstorm WarningLSXFranklin, Jefferson, Saint Francois, Washington68 min
Apr 7, 6:27 PM CDTSevere Thunderstorm WarningLSXSaint Louis, City of Saint Louis49 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.