Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 150, NWS St. Louis, MO

August 23, 2021Saint Louis County, City of Saint Louis, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 23, 2021, 3:33 PM CDT for Saint Louis County, City of Saint Louis, Missouri. It was in force for 27 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: Aug 23, 2021, 3:33 PM CDT (20:33 UTC)
Expired: Aug 23, 2021, 4:00 PM CDT
In force: 27 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties City of Saint Louis, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 40 km from the middle of the area, began a volume at 20:37 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

Time	Report	Where	Remark
Aug 23, 3:46 PM CDT	TSTM WND DMG	1 Nne Normandy, MO	SEVERAL LARGE LIMBS DOWN IN THE NORMANDY AREA.
Aug 23, 3:47 PM CDT	TSTM WND DMG	Cool Valley, MO	MULTIPLE TREES DOWN IN THE COOL VALLEY AREA, INCLUDING ONE UPROOTED AND SOME FENCE DAMAGE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.6 hours before the alert went out and 214 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

410 
WUUS53 KLSX 232033
SVRLSX
MOC189-510-232100-
/O.NEW.KLSX.SV.W.0150.210823T2033Z-210823T2100Z/

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

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Central St. Louis City in east central Missouri...
  East central St. Louis County in east central Missouri...

* Until 400 PM CDT.

* At 332 PM CDT, a severe thunderstorm was located over Pine Lawn,
  and is nearly stationary.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  St. Louis around 340 PM CDT.

This also includes Scott Joplin Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3862 9025 3872 9034 3878 9020 3875 9018
      3873 9021 3871 9021 3868 9019 3865 9018
TIME...MOT...LOC 2032Z 332DEG 4KT 3869 9023 

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

$$

Byrd

1 follow-up statement

685 
WWUS53 KLSX 232101
SVSLSX

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

MOC189-510-232111-
/O.EXP.KLSX.SV.W.0150.000000T0000Z-210823T2100Z/
St. Louis City MO-St. Louis MO-
401 PM CDT Mon Aug 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL ST. LOUIS COUNTY
AND CENTRAL ST. LOUIS CITY 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.  However gusty
winds are still possible with this thunderstorm.

LAT...LON 3862 9025 3872 9034 3878 9020 3875 9018
      3873 9021 3871 9021 3868 9019 3865 9018
TIME...MOT...LOC 2101Z 332DEG 4KT 3866 9021 

$$

Byrd

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 23, 3:05 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles	25 min
Aug 23, 4:01 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Saint Charles, Warren	17 min
Aug 23, 6:04 PM CDT	Areal Flood Advisory	LSX	Sainte Genevieve	3 hr

Nearby

Severe Thunderstorm Warnings in Missouri, 2021 Every 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.