Alert archive / Missouri / Tornado Warnings in 2023

Tornado Warning 27, NWS St. Louis, MO

August 4, 2023Franklin County, Saint Charles County, Warren County, Missouri

NWS St. Louis, MO issued this tornado warning at Aug 4, 2023, 11:29 PM CDT for Franklin County, Saint Charles County, Warren County, Missouri. It was in force for 24 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 4, 2023, 11:29 PM CDT (04:29 UTC)
Expired
Aug 4, 2023, 11:53 PM CDT
In force
24 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Franklin County, MO, Saint Charles County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 23 km from the middle of the area, began a volume at 04:28 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
Aug 4, 5:17 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 4.5 hours before the alert went out and 264 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 00:00Z on 2023-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 203 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 00:00Z on 2023-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 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
203 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
1384 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.4

Open this sounding in Storm Lab

The text

As transmitted.

488 
WFUS53 KLSX 050429
TORLSX
MOC071-183-219-050515-
/O.NEW.KLSX.TO.W.0027.230805T0429Z-230805T0515Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service St Louis MO
1129 PM CDT Fri Aug 4 2023

The National Weather Service in St Louis has issued a

* Tornado Warning for...
  Southwestern St. Charles County in east central Missouri...
  Northeastern Franklin County in east central Missouri...
  Southeastern Warren County in east central Missouri...

* Until 1215 AM CDT.
    
* At 1128 PM CDT, a severe thunderstorm capable of producing a
  tornado was located over Washington, moving east at 45 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Washington and Augusta around 1135 PM CDT.
  Defiance around 1145 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 3863 9111 3870 9074 3864 9073 3849 9074
      3850 9109
TIME...MOT...LOC 0428Z 263DEG 38KT 3857 9103 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

19
2 follow-up statements
270 
WWUS53 KLSX 050441
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1141 PM CDT Fri Aug 4 2023

MOC219-050451-
/O.CAN.KLSX.TO.W.0027.000000T0000Z-230805T0515Z/
Warren MO-
1141 PM CDT Fri Aug 4 2023

...THE TORNADO WARNING FOR SOUTHEASTERN WARREN COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has 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 3866 9096 3870 9074 3864 9073 3852 9074
      3852 9093 3855 9097
TIME...MOT...LOC 0441Z 260DEG 33KT 3859 9086 

$$

MOC071-183-050515-
/O.CON.KLSX.TO.W.0027.000000T0000Z-230805T0515Z/
St. Charles MO-Franklin MO-
1141 PM CDT Fri Aug 4 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1215 AM CDT FOR
SOUTHWESTERN ST. CHARLES AND EAST CENTRAL FRANKLIN COUNTIES...
    
At 1141 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Augusta, moving east at 40 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Defiance around 1145 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 3866 9096 3870 9074 3864 9073 3852 9074
      3852 9093 3855 9097
TIME...MOT...LOC 0441Z 260DEG 33KT 3859 9086 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

19
999 
WWUS53 KLSX 050453
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1153 PM CDT Fri Aug 4 2023

MOC071-183-050502-
/O.CAN.KLSX.TO.W.0027.000000T0000Z-230805T0515Z/
St. Charles MO-Franklin MO-
1153 PM CDT Fri Aug 4 2023

...THE TORNADO WARNING FOR SOUTHWESTERN ST. CHARLES AND EAST CENTRAL
FRANKLIN COUNTIES IS CANCELLED...
                
The storm which prompted the warning no longer appears capable of 
producing a tornado.Therefore, the warning has been cancelled. 
However, gusty winds are still possible with this thunderstorm.

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

Remember, a Severe Thunderstorm Warning still remains in effect for
St. Charles and Franklin Counties.

LAT...LON 3866 9096 3870 9074 3864 9073 3852 9074
      3852 9093 3855 9097
TIME...MOT...LOC 0451Z 263DEG 38KT 3860 9071 

$$

19

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 8:21 PM CDTSevere Thunderstorm WarningLSXBoone, Cole, Moniteau54 min
Aug 4, 8:41 PM CDTTornado WarningLSXMoniteau49 min
Aug 4, 9:12 PM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole, Moniteau48 min
Aug 4, 9:44 PM CDTSevere Thunderstorm WarningLSXCallaway, Cole, Osage46 min
Aug 4, 9:53 PM CDTTornado WarningLSXCallaway22 min
Aug 4, 10:02 PM CDTSevere Thunderstorm WarningLSXCallaway, Gasconade, Montgomery, Osage43 min
Aug 4, 11:22 PM CDTSevere Thunderstorm WarningLSXFranklin, Jefferson, Saint Charles, Saint Louis, Warren38 min
Aug 4, 11:52 PM CDTSevere Thunderstorm WarningLSXKnox38 min
Aug 4, 11:53 PM CDTFlash Flood WarningLSXKnox, Lewis4 hr
Aug 5, 1:58 AM CDTSevere Thunderstorm WarningLSXSainte Genevieve32 min
Aug 5, 2:25 AM CDTAreal Flood AdvisoryLSXJefferson, Sainte Genevieve, Saint Francois, Washington3 hr
Aug 5, 2:29 AM CDTSevere Thunderstorm WarningLSXSainte Genevieve, Saint Francois31 min

Nearby

Tornado Warnings in Missouri, 2023Every tornado warning in 2023Tornadoes in 2023

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.