Alert archive / Missouri / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 166, NWS St. Louis, MO

July 20, 2015Saint Charles County, Saint Louis County, City of Saint Louis, Missouri; Madison County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 20, 2015, 9:43 AM CDT for Saint Charles County, Saint Louis County, City of Saint Louis, Missouri; Madison County, Saint Clair County, Illinois. It was in force for 47 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
Jul 20, 2015, 9:43 AM CDT (14:43 UTC)
Expired
Jul 20, 2015, 10:30 AM CDT
In force
47 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Madison County, IL, Saint Clair County, IL, City of Saint Louis, MO, Saint Charles County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 50 km from the middle of the area, began a volume at 14:46 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 20, 9:51 AM CDTTSTM WND GST 511 Ssw Hazelwood, MO
Jul 20, 9:54 AM CDTTSTM WND GST 551 Ssw Hazelwood, 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 12:00Z, 2.7 hours before the alert went out and 210 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 2015-07-20Temperature 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 12:00Z on 2015-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 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
1276 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

352 
WUUS53 KLSX 201443
SVRLSX
ILC119-163-MOC183-189-510-201530-
/O.NEW.KLSX.SV.W.0166.150720T1443Z-150720T1530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
943 AM CDT MON JUL 20 2015

THE NATIONAL WEATHER SERVICE IN ST LOUIS  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN MADISON COUNTY IN SOUTHWESTERN ILLINOIS...
  NORTHERN ST. CLAIR COUNTY IN SOUTHWESTERN ILLINOIS...
  ST. LOUIS CITY IN EAST CENTRAL MISSOURI...
  NORTHEASTERN ST. CHARLES COUNTY IN EAST CENTRAL MISSOURI...
  NORTHEASTERN ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 1030 AM CDT

* AT 943 AM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
  EXTENDING FROM NEAR ST. PETERS TO BRECKENRIDGE HILLS TO
  MAPLEWOOD...MOVING EAST AT 35 MPH.

  HAZARD...60 MPH WIND GUSTS. 

  SOURCE...RADAR INDICATED. 

  IMPACT...EXPECT DAMAGE TO ROOFS...SIDING AND TREES. 

* LOCATIONS IMPACTED INCLUDE...
  ST. LOUIS...ST. CHARLES...ST. PETERS...FLORISSANT...BELLEVILLE...
  UNIVERSITY CITY...GRANITE CITY...O'FALLON...ALTON...KIRKWOOD...
  MARYLAND HEIGHTS...EAST ST. LOUIS...HAZELWOOD...COLLINSVILLE...
  EDWARDSVILLE...WEBSTER GROVES...FERGUSON...CREVE COEUR...FAIRVIEW
  HEIGHTS AND OVERLAND.

THIS INCLUDES THE FOLLOWING HIGHWAYS...
 INTERSTATE 70 IN ILLINOIS NEAR EXIT 21.
 INTERSTATE 55 IN ILLINOIS NEAR EXIT 23.
 INTERSTATE 64 IN ILLINOIS BETWEEN EXITS 9 AND 27.
 INTERSTATE 70 IN MISSOURI BETWEEN EXITS 222 AND 231.

THIS WARNING ALSO INCLUDES ... 
SCOTT JOPLIN HISTORIC SITE...CONFLUENCE STATE PARK...FIRST MISSOURI
STATE CAPITOL HISTORIC SITE...AND HORSESHOE LAKE STATE PARK.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

TORRENTIAL RAINFALL IS OCCURRING WITH THESE STORMS...AND MAY LEAD TO
FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS.

&&

LAT...LON 3848 8973 3853 9036 3871 9046 3883 9069
      3891 9009 3873 8972
TIME...MOT...LOC 1443Z 268DEG 30KT 3883 9059 3872 9038 3860 9031 

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

BYRD
2 follow-up statements
134 
WWUS53 KLSX 201514
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1014 AM CDT MON JUL 20 2015

MOC510-201523-
/O.CAN.KLSX.SV.W.0166.000000T0000Z-150720T1530Z/
ST. LOUIS CITY MO-
1014 AM CDT MON JUL 20 2015

...THE SEVERE THUNDERSTORM WARNING FOR ST. LOUIS CITY IS CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE MOVED 
OUT OF THE CITY. THEREFORE THE WARNING HAS BEEN CANCELLED.

LAT...LON 3848 8973 3851 9010 3868 9019 3871 9021
      3873 9021 3875 9018 3877 9017 3877 9018
      3875 9019 3873 9023 3886 9033 3889 9005
      3873 8972
TIME...MOT...LOC 1513Z 267DEG 30KT 3885 9014 3873 9007 3853 8997 

$$

ILC119-163-MOC183-189-201530-
/O.CON.KLSX.SV.W.0166.000000T0000Z-150720T1530Z/
MADISON IL-ST. CLAIR IL-ST. CHARLES MO-ST. LOUIS MO-
1014 AM CDT MON JUL 20 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 AM CDT
FOR SOUTHERN MADISON AND NORTHEASTERN ST. CLAIR COUNTIES IN
SOUTHWESTERN ILLINOIS...EAST CENTRAL ST. CHARLES AND NORTHEASTERN ST.
LOUIS COUNTIES IN EAST CENTRAL MISSOURI...

AT 1013 AM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
EXTENDING FROM NEAR EAST ALTON TO PONTOON BEACH TO SWANSEA...MOVING
EAST AT 35 MPH.

HAZARD...60 MPH WIND GUSTS. 

SOURCE...RADAR INDICATED. 

IMPACT...EXPECT DAMAGE TO ROOFS...SIDING AND TREES. 

LOCATIONS IMPACTED INCLUDE...
ST. LOUIS...FLORISSANT...BELLEVILLE...GRANITE CITY...O'FALLON...
ALTON...EAST ST. LOUIS...COLLINSVILLE...EDWARDSVILLE...FAIRVIEW
HEIGHTS...SWANSEA...GLEN CARBON...SHILOH...BELLEFONTAINE NEIGHBORS...
WOOD RIVER...TROY...BETHALTO...MARYVILLE...MASCOUTAH AND BLACK JACK.

THIS WARNING ALSO INCLUDES CONFLUENCE STATE PARK AND HORSESHOE LAKE
STATE PARK.
 
THIS INCLUDES THE FOLLOWING HIGHWAYS...
 INTERSTATE 70 IN ILLINOIS NEAR EXIT 21.
 INTERSTATE 55 IN ILLINOIS NEAR EXIT 23.
 INTERSTATE 64 IN ILLINOIS BETWEEN EXITS 9 AND 27.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

TORRENTIAL RAINFALL IS OCCURRING WITH THESE STORMS...AND MAY LEAD TO
FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS.

&&

LAT...LON 3848 8973 3851 9010 3868 9019 3871 9021
      3873 9021 3875 9018 3877 9017 3877 9018
      3875 9019 3873 9023 3886 9033 3889 9005
      3873 8972
TIME...MOT...LOC 1513Z 267DEG 30KT 3885 9014 3873 9007 3853 8997 

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

BYRD
417 
WWUS53 KLSX 201529
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1029 AM CDT MON JUL 20 2015

ILC119-163-MOC183-189-201539-
/O.EXP.KLSX.SV.W.0166.000000T0000Z-150720T1530Z/
MADISON IL-ST. CLAIR IL-ST. CHARLES MO-ST. LOUIS MO-
1029 AM CDT MON JUL 20 2015

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN MADISON AND
NORTHEASTERN ST. CLAIR COUNTIES IN SOUTHWESTERN ILLINOIS...EAST
CENTRAL ST. CHARLES AND NORTHEASTERN ST. LOUIS COUNTIES IN EAST
CENTRAL MISSOURI WILL EXPIRE AT 1030 AM CDT...
            
THE STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.  HOWEVER HEAVY RAIN
IS STILL POSSIBLE WITH THESE THUNDERSTORMS.

LAT...LON 3848 8973 3851 9010 3868 9019 3871 9021
      3873 9021 3875 9018 3877 9017 3877 9018
      3875 9019 3873 9023 3886 9033 3889 9005
      3873 8972
TIME...MOT...LOC 1524Z 268DEG 30KT 3885 9014 3873 9007 3853 8997 

$$

BYRD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 7:49 PM CDTRiver Flood WarningLSXLewis3 days
Jul 19, 9:21 PM CDTRiver Flood WarningLSXLewis48 hr
Jul 20, 3:36 AM CDTFlash Flood WarningLSXReynolds6 hr
Jul 20, 7:28 AM CDTFlash Flood WarningLSXMoniteau6 hr
Jul 20, 5:02 PM CDTSevere Thunderstorm WarningLSXIron, Madison43 min
Jul 20, 6:00 PM CDTTornado WarningLSXIron, Madison14 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2015Severe Thunderstorm Warnings in Illinois, 2015Every severe thunderstorm warning in 2015

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.