Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 149, NWS St. Louis, MO

August 23, 2021Saint Charles County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 23, 2021, 3:05 PM CDT for Saint Charles County, Missouri. It was in force for 25 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
Aug 23, 2021, 3:05 PM CDT (20:05 UTC)
Expired
Aug 23, 2021, 3:30 PM CDT
In force
25 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Saint Charles County, MO

The radar

The St Louis radar (KLSX), 27 km from the middle of the area, began a volume at 20:08 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 nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.1 hours before the alert went out and 268 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 12:00Z on 2021-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 12:00Z on 2021-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 118 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
1261 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
118 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

636 
WUUS53 KLSX 232005
SVRLSX
MOC183-232030-
/O.NEW.KLSX.SV.W.0149.210823T2005Z-210823T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
305 PM CDT Mon Aug 23 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Southwestern St. Charles County in east central Missouri...

* Until 330 PM CDT.

* At 304 PM CDT, a severe thunderstorm was located over Augusta, and
  is nearly stationary.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Augusta.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 3861 9096 3856 9085 3853 9091 3853 9093
      3854 9096 3855 9097 3856 9097
TIME...MOT...LOC 2004Z 240DEG 4KT 3857 9093 

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

$$

Byrd
1 follow-up statement
059 
WWUS53 KLSX 232026
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
326 PM CDT Mon Aug 23 2021

MOC183-232036-
/O.EXP.KLSX.SV.W.0149.000000T0000Z-210823T2030Z/
St. Charles MO-
326 PM CDT Mon Aug 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN ST. CHARLES
COUNTY WILL EXPIRE AT 330 PM CDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

LAT...LON 3861 9096 3856 9085 3853 9091 3853 9093
      3854 9096 3855 9097 3856 9097
TIME...MOT...LOC 2026Z 240DEG 4KT 3858 9090 

$$

Byrd

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 23, 3:33 PM CDTSevere Thunderstorm WarningLSXSaint Louis, City of Saint Louis27 min
Aug 23, 4:01 PM CDTSevere Thunderstorm WarningLSXLincoln, Saint Charles, Warren17 min
Aug 23, 6:04 PM CDTAreal Flood AdvisoryLSXSainte Genevieve3 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.