Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 90, NWS St. Louis, MO

June 20, 20215 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 20, 2021, 11:59 PM CDT for 5 counties in Missouri. It was in force for 31 min. 1 report 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, 11:59 PM CDT (04:59 UTC)
Expired
Jun 21, 2021, 12:30 AM CDT
In force
31 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Franklin County, MO, Gasconade County, MO, Montgomery County, MO, Osage County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 74 km from the middle of the area, began a volume at 05:02 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
Jun 21, 12:20 AM CDTTSTM WND DMGNew Haven, MONUMEROUS LARGE TREE LIMBS BLOWN DOWN AROUND TOWN.

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

Springfield, MO (KSGF), launched 00:00Z, 5.0 hours before the alert went out and 277 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 00:00Z on 2021-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1346 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, Springfield, MO at 00:00Z on 2021-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 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
1346 J/kg
Mixed-layer CIN
-132 J/kg
Mixed-layer LCL
1683 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
264 m²/s²
Significant tornado parameter
0.2
Supercell composite
5.8

Open this sounding in Storm Lab

The text

As transmitted.

804 
WUUS53 KLSX 210459
SVRLSX
MOC071-073-139-151-219-210530-
/O.NEW.KLSX.SV.W.0090.210621T0459Z-210621T0530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
1159 PM CDT Sun Jun 20 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Southwestern Montgomery County in east central Missouri...
  Northwestern Franklin County in east central Missouri...
  Northeastern Osage County in central Missouri...
  Southwestern Warren County in east central Missouri...
  Northern Gasconade County in east central Missouri...

* Until 1230 AM CDT.

* At 1159 PM CDT, severe thunderstorms were located along a line
  extending from Hermann to near Mount Sterling, moving east at 65
  mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  New Haven, Gerald and Treloar around 1210 AM CDT.

This also includes Deutschheim Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3870 9168 3870 9165 3877 9164 3870 9111
      3835 9125 3854 9173
TIME...MOT...LOC 0459Z 283DEG 55KT 3871 9142 3850 9155 

HAIL...<.75IN
WIND...60MPH
 
$$

19
2 follow-up statements
572 
WWUS53 KLSX 210511
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1211 AM CDT Mon Jun 21 2021

MOC139-151-210521-
/O.CAN.KLSX.SV.W.0090.000000T0000Z-210621T0530Z/
Montgomery MO-Osage MO-
1211 AM CDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MONTGOMERY AND
NORTHEASTERN OSAGE COUNTIES 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
east central Missouri.

LAT...LON 3864 9153 3871 9149 3871 9142 3874 9141
      3870 9111 3835 9125 3850 9163
TIME...MOT...LOC 0511Z 283DEG 55KT 3867 9119 3846 9133 

$$

MOC071-073-219-210530-
/O.CON.KLSX.SV.W.0090.000000T0000Z-210621T0530Z/
Franklin MO-Warren MO-Gasconade MO-
1211 AM CDT Mon Jun 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT
FOR NORTHWESTERN FRANKLIN...SOUTHWESTERN WARREN AND NORTHERN
GASCONADE COUNTIES...

At 1211 AM CDT, severe thunderstorms were located along a line
extending from Treloar to near Gerald, moving east at 65 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

These severe thunderstorms will remain over mainly rural areas of
northwestern Franklin, southwestern Warren and northern Gasconade
Counties, including the following locations... Berger, Holstein,
Leslie and Bay.

This also includes Deutschheim Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3864 9153 3871 9149 3871 9142 3874 9141
      3870 9111 3835 9125 3850 9163
TIME...MOT...LOC 0511Z 283DEG 55KT 3867 9119 3846 9133 

HAIL...<.75IN
WIND...60MPH
 
$$

19
289 
WWUS53 KLSX 210524
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1224 AM CDT Mon Jun 21 2021

MOC071-073-219-210532-
/O.EXP.KLSX.SV.W.0090.000000T0000Z-210621T0530Z/
Franklin MO-Warren MO-Gasconade MO-
1224 AM CDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN FRANKLIN...
SOUTHWESTERN WARREN AND NORTHERN GASCONADE COUNTIES WILL EXPIRE AT
1230 AM CDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire.  However gusty winds are still possible with
these thunderstorms.

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

LAT...LON 3864 9153 3871 9149 3871 9142 3874 9141
      3870 9111 3835 9125 3850 9163
TIME...MOT...LOC 0522Z 283DEG 55KT 3863 9099 3842 9113 

$$

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, 10:10 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 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.