Alert archive / Missouri / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 21, NWS St. Louis, MO

April 7, 2015Jefferson County, Saint Louis County, City of Saint Louis, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 7, 2015, 9:26 AM CDT for Jefferson County, Saint Louis County, City of Saint Louis, Missouri. It was in force for 49 min. 11 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: Apr 7, 2015, 9:26 AM CDT (14:26 UTC)
Expired: Apr 7, 2015, 10:15 AM CDT
In force: 49 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.75 in
Wind: 50.0 mph

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

The radar

The St Louis radar (KLSX), 35 km from the middle of the area, began a volume at 14:27 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
Apr 7, 9:28 AM CDT	HAIL 1	Chesterfield, MO	HAIL SIZE RANGED FROM DIME-SIZE TO QUARTER-SIZE IN CHESTERFIELD.
Apr 7, 9:29 AM CDT	HAIL 1	Ballwin, MO
Apr 7, 9:30 AM CDT	HAIL 0.88	Town And Country, MO
Apr 7, 9:30 AM CDT	HAIL 1	Chesterfield, MO
Apr 7, 9:31 AM CDT	HAIL 1	Ballwin, MO
Apr 7, 9:32 AM CDT	HAIL 0.88	Chesterfield, MO
Apr 7, 9:40 AM CDT	HAIL 0.5	Valley Park, MO
Apr 7, 9:43 AM CDT	HAIL 0.5	Des Peres, MO
Apr 7, 9:46 AM CDT	HAIL 1	Des Peres, MO
Apr 7, 9:55 AM CDT	HAIL 0.75	Frontenac, MO	HAIL INCREASING IN SIZE AT LINDBERGH BLVD AND I-64... VIA AMATEUR RADIO.
Apr 7, 10:01 AM CDT	HAIL 0.25	St. Louis, MO

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 7, 8:34 AM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 2.4 hours before the alert went out and 230 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: 134 J/kg
Mixed-layer CIN: -199 J/kg
Mixed-layer LCL: 443 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 23 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, in the capitals the NWS used until 2016.

275 
WUUS53 KLSX 071426
SVRLSX
MOC099-189-510-071515-
/O.NEW.KLSX.SV.W.0021.150407T1426Z-150407T1515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
926 AM CDT TUE APR 7 2015

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN JEFFERSON COUNTY IN EAST CENTRAL MISSOURI...
  SOUTHERN ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...
  ST. LOUIS CITY IN EAST CENTRAL MISSOURI...

* UNTIL 1015 AM CDT

* AT 922 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR
  ELLISVILLE...AND MOVING EAST AT 30 MPH.

  HAZARD...GOLF BALL SIZE HAIL.

  SOURCE...TRAINED WEATHER SPOTTERS. HALF DOLLAR SIZE HAIL HAS BEEN
           REPORTED IN WILDWOOD.

  IMPACT...PEOPLE AND ANIMALS OUTDOORS WILL BE INJURED. EXPECT DAMAGE
           TO ROOFS...SIDING...WINDOWS AND VEHICLES.

* LOCATIONS IMPACTED INCLUDE...
  MANCHESTER...TOWN AND COUNTRY...VALLEY PARK...MURPHY...CREVE
  COEUR...DES PERES...FENTON...FRONTENAC...KIRKWOOD...SUNSET HILLS...
  WARSON WOODS...OLIVETTE...LADUE...GLENDALE...OAKLAND...CRESTWOOD...
  BRENTWOOD...WEBSTER GROVES...UNIVERSITY CITY AND CLAYTON.

THIS WARNING INCLUDES CASTLEWOOD STATE PARK...ROUTE 66 STATE PARK AND
SCOTT JOPLIN HISTORIC SITE.

THIS WARNING ALSO INCLUDES...
INTERSTATE 44 FROM EXIT 261 TO EXIT 277.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. PREPARE IMMEDIATELY FOR LARGE DESTRUCTIVE
HAIL CAPABLE OF PRODUCING SIGNIFICANT DAMAGE. PEOPLE OUTSIDE SHOULD
MOVE TO A SHELTER...INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 3859 9020 3855 9024 3852 9027 3847 9028
      3844 9029 3848 9072 3868 9063 3867 9019
      3862 9018
TIME...MOT...LOC 1425Z 280DEG 24KT 3858 9055

HAIL...1.75IN
WIND...<50MPH

$$

GLASS

2 follow-up statements

708 
WWUS53 KLSX 071434
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
934 AM CDT TUE APR 7 2015

MOC099-189-510-071515-
/O.CON.KLSX.SV.W.0021.000000T0000Z-150407T1515Z/
JEFFERSON MO-ST. LOUIS MO-ST. LOUIS CITY MO-
934 AM CDT TUE APR 7 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR ST. LOUIS
CITY...SOUTHERN ST. LOUIS AND NORTHEASTERN JEFFERSON COUNTIES UNTIL
1015 AM CDT...

AT 932 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR VALLEY PARK...
AND MOVING EAST AT 30 MPH.

HAZARD...GOLF BALL SIZE HAIL.

SOURCE...TRAINED WEATHER SPOTTERS. NUMEROUS REPORTS OF QUARTER SIZE 
         HAIL IN CHESTERFIELD...WILDWOOD...AND BALLWIN.

IMPACT...PEOPLE AND ANIMALS OUTDOORS WILL BE INJURED. EXPECT DAMAGE
         TO ROOFS...SIDING...WINDOWS AND VEHICLES.

LOCATIONS IMPACTED INCLUDE...
CREVE COEUR...DES PERES...FENTON...FRONTENAC...KIRKWOOD...SUNSET
HILLS...WARSON WOODS...OLIVETTE...LADUE...GLENDALE...OAKLAND...
CRESTWOOD...BRENTWOOD...WEBSTER GROVES...UNIVERSITY CITY...CLAYTON...
RICHMOND HEIGHTS...MAPLEWOOD...SHREWSBURY AND LAKESHIRE.

THIS WARNING INCLUDES CASTLEWOOD STATE PARK...ROUTE 66 STATE PARK AND
SCOTT JOPLIN HISTORIC SITE.

THIS WARNING ALSO INCLUDES...
INTERSTATE 44 FROM EXIT 261 TO EXIT 277.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. PREPARE IMMEDIATELY FOR LARGE DESTRUCTIVE
HAIL CAPABLE OF PRODUCING SIGNIFICANT DAMAGE. PEOPLE OUTSIDE SHOULD
MOVE TO A SHELTER...INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 3859 9020 3857 9023 3854 9025 3852 9027
      3844 9029 3848 9072 3868 9058 3867 9019
      3862 9018
TIME...MOT...LOC 1434Z 280DEG 24KT 3857 9047

HAIL...1.75IN
WIND...<50MPH

$$

GLASS

834 
WWUS53 KLSX 071443
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
943 AM CDT TUE APR 7 2015

MOC099-189-510-071515-
/O.CON.KLSX.SV.W.0021.000000T0000Z-150407T1515Z/
JEFFERSON MO-ST. LOUIS MO-ST. LOUIS CITY MO-
943 AM CDT TUE APR 7 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR ST. LOUIS
CITY...SOUTHERN ST. LOUIS AND NORTHEASTERN JEFFERSON COUNTIES UNTIL
1015 AM CDT...

AT 942 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR KIRKWOOD...AND
MOVING EAST AT 30 MPH.

HAZARD...GOLF BALL SIZE HAIL.

SOURCE...TRAINED WEATHER SPOTTERS.

IMPACT...PEOPLE AND ANIMALS OUTDOORS WILL BE INJURED. EXPECT DAMAGE
         TO ROOFS...SIDING...WINDOWS AND VEHICLES.

LOCATIONS IMPACTED INCLUDE...
SUNSET HILLS...WARSON WOODS...OLIVETTE...LADUE...GLENDALE...
OAKLAND...CRESTWOOD...BRENTWOOD...WEBSTER GROVES...UNIVERSITY CITY...
CLAYTON...RICHMOND HEIGHTS...MAPLEWOOD...SHREWSBURY...LAKESHIRE...
AFFTON...MEHLVILLE...LEMAY AND ST. LOUIS.

THIS WARNING INCLUDES CASTLEWOOD STATE PARK...ROUTE 66 STATE PARK AND
SCOTT JOPLIN HISTORIC SITE.

THIS WARNING ALSO INCLUDES...
INTERSTATE 44 FROM EXIT 261 TO EXIT 277.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. PREPARE IMMEDIATELY FOR LARGE DESTRUCTIVE
HAIL CAPABLE OF PRODUCING SIGNIFICANT DAMAGE. PEOPLE OUTSIDE SHOULD
MOVE TO A SHELTER...INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 3852 9027 3844 9029 3848 9072 3867 9050
      3867 9019 3862 9018
TIME...MOT...LOC 1443Z 280DEG 24KT 3857 9042

HAIL...1.75IN
WIND...<50MPH

$$

GLASS

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 7, 4:59 AM CDT	Severe Thunderstorm Warning	LSX	Boone	46 min
Apr 7, 5:34 AM CDT	Severe Thunderstorm Warning	LSX	Audrain, Callaway	56 min
Apr 7, 6:23 AM CDT	Severe Thunderstorm Warning	LSX	Callaway, Montgomery	67 min
Apr 7, 7:06 AM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Montgomery, Warren	54 min
Apr 7, 7:56 AM CDT	Severe Thunderstorm Warning	LSX	Franklin, Saint Charles, Saint Louis, Warren	49 min
Apr 7, 8:42 AM CDT	Severe Thunderstorm Warning	LSX	Franklin, Jefferson, Saint Charles, Saint Louis	48 min
Apr 7, 9:18 AM CDT	Severe Thunderstorm Warning	LSX	Franklin, Jefferson	42 min
Apr 7, 9:42 AM CDT	Flash Flood Warning	LSX	Franklin, Jefferson, Saint Charles, Saint Louis, Warren	8 hr
Apr 7, 9:58 AM CDT	Severe Thunderstorm Warning	LSX	Franklin, Jefferson	47 min
Apr 7, 10:03 AM CDT	Severe Thunderstorm Warning	LSX	Saint Louis, City of Saint Louis	42 min
Apr 7, 10:43 AM CDT	Areal Flood Advisory	LSX	Saint Louis, City of Saint Louis	4 hr
Apr 7, 10:53 AM CDT	Flash Flood Warning	LSX	Crawford, Franklin, Jefferson, Washington	4 hr
Apr 7, 12:42 PM CDT	River Flood Warning	LSX	Saint Charles	35 hr
Apr 7, 12:47 PM CDT	Flash Flood Warning	LSX	Jefferson, Sainte Genevieve, Saint Francois, Washington	6 hr

Nearby

Severe Thunderstorm Warnings in Missouri, 2015 Every 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.