Alert archive / Missouri / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 113, NWS St. Louis, MO

July 19, 20204 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 19, 2020, 7:32 PM CDT for 4 counties in Missouri. It was in force for 43 min. 3 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
Jul 19, 2020, 7:32 PM CDT (00:32 UTC)
Expired
Jul 19, 2020, 8:15 PM CDT
In force
43 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

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

The radar

The St Louis radar (KLSX), 30 km from the middle of the area, began a volume at 00:35 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
Jul 19, 7:45 PM CDTHAIL 1Valley Park, MO
Jul 19, 7:57 PM CDTTSTM WND DMGFenton, MOROAD SIGNS BLOWN DOWN.
Jul 19, 8:00 PM CDTHAIL 0.7Manchester, MO

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 00:00Z, 0.5 hours before the alert went out and 222 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 2020-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2020-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 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
1662 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

640 
WUUS53 KLSX 200032
SVRLSX
MOC099-183-189-510-200115-
/O.NEW.KLSX.SV.W.0113.200720T0032Z-200720T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
732 PM CDT Sun Jul 19 2020

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Central St. Louis City in east central Missouri...
  Central St. Charles County in east central Missouri...
  North central Jefferson County in east central Missouri...
  St. Louis County in east central Missouri...

* Until 815 PM CDT.

* At 732 PM CDT, a severe thunderstorm was located over Fenton,
  moving northeast at 25 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  St. Louis, St. Charles, St. Peters, Florissant, Chesterfield,
  Wildwood, University City, Ballwin, Kirkwood, Maryland Heights,
  Hazelwood, Webster Groves, Ferguson, Arnold, Manchester, Creve
  Coeur, Overland, Clayton, Jennings and St. Ann.

This includes the following highways...
 Interstate 44 in Missouri between exits 261 and 277.
 Interstate 70 in Missouri between exits 227 and 231.

This also includes Route 66 State Park, Castlewood State Park, and
First Missouri State Capitol Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in St Louis.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3872 9021 3871 9021 3868 9019 3841 9043
      3851 9071 3883 9053 3876 9018
TIME...MOT...LOC 0032Z 198DEG 22KT 3852 9047 

HAIL...1.00IN
WIND...60MPH
 
$$

TES
2 follow-up statements
649 
WWUS53 KLSX 200056
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
756 PM CDT Sun Jul 19 2020

MOC099-200105-
/O.CAN.KLSX.SV.W.0113.000000T0000Z-200720T0115Z/
Jefferson MO-
756 PM CDT Sun Jul 19 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL JEFFERSON COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3876 9018 3872 9021 3871 9021 3868 9019
      3847 9038 3848 9042 3849 9040 3850 9041
      3850 9050 3854 9066 3883 9053
TIME...MOT...LOC 0055Z 204DEG 13KT 3861 9044 

$$

MOC183-189-510-200115-
/O.CON.KLSX.SV.W.0113.000000T0000Z-200720T0115Z/
St. Louis City MO-St. Charles MO-St. Louis MO-
756 PM CDT Sun Jul 19 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR CENTRAL ST. CHARLES AND ST. LOUIS COUNTIES AND CENTRAL ST. LOUIS
CITY...

At 755 PM CDT, a severe thunderstorm was located over Crystal Lake
Park, moving northeast at 15 mph.

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

SOURCE...Trained weather spotters reported wind damage and large 
         hail in the Fenton and Valley Park areas.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
St. Louis, St. Charles, St. Peters, Florissant, Chesterfield,
Wildwood, University City, Ballwin, Kirkwood, Maryland Heights,
Hazelwood, Webster Groves, Ferguson, Manchester, Creve Coeur,
Overland, Clayton, Jennings, St. Ann and Crestwood.

This also includes Castlewood State Park and First Missouri State
Capitol Historic Site.
 
This includes the following highways...
 Interstate 44 in Missouri between exits 269 and 277.
 Interstate 70 in Missouri between exits 227 and 231.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
St Louis.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3876 9018 3872 9021 3871 9021 3868 9019
      3847 9038 3848 9042 3849 9040 3850 9041
      3850 9050 3854 9066 3883 9053
TIME...MOT...LOC 0055Z 204DEG 13KT 3861 9044 

HAIL...1.00IN
WIND...60MPH
 
$$

TES
843 
WWUS53 KLSX 200115
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
815 PM CDT Sun Jul 19 2020

MOC183-189-510-200125-
/O.EXP.KLSX.SV.W.0113.000000T0000Z-200720T0115Z/
St. Louis City MO-St. Charles MO-St. Louis MO-
815 PM CDT Sun Jul 19 2020

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL ST. CHARLES AND ST.
LOUIS COUNTIES 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 and heavy rain are still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
St Louis.

LAT...LON 3876 9018 3872 9021 3871 9021 3868 9019
      3847 9038 3848 9042 3849 9040 3850 9041
      3850 9050 3854 9066 3883 9053
TIME...MOT...LOC 0115Z 198DEG 22KT 3872 9039 

$$

TES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 7:46 PM CDTSevere Thunderstorm WarningLSXFranklin, Gasconade44 min
Jul 19, 8:08 PM CDTSevere Thunderstorm WarningLSXCity of Saint Louis39 min
Jul 19, 8:57 PM CDTFlash Flood WarningLSXCrawford, Franklin, Gasconade6 hr

Nearby

Severe Thunderstorm Warnings in Missouri, 2020Every severe thunderstorm warning in 2020

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.