Alert archive / Missouri / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 4, NWS St. Louis, MO

January 17, 2012Saint Charles County, Saint Louis County, Missouri; Calhoun County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jan 17, 2012, 1:23 AM CST for Saint Charles County, Saint Louis County, Missouri; Calhoun County, Illinois. It was in force for 37 min. 12 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: Jan 17, 2012, 1:23 AM CST (07:23 UTC)
Expired: Jan 17, 2012, 2:00 AM CST
In force: 37 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Calhoun County, IL, Saint Charles County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 20 km from the middle of the area, began a volume at 07:27 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
Jan 17, 1:34 AM CST	HAIL 0.5	Weldon Spring, MO	AT NWS OFFICE.
Jan 17, 1:36 AM CST	HAIL 0.25	2 W St. Peters, MO
Jan 17, 1:45 AM CST	HAIL 0.25	Chesterfield, MO
Jan 17, 1:47 AM CST	HAIL 0.25	St. Charles, MO
Jan 17, 1:50 AM CST	TSTM WND DMG	Town And Country, MO	LARGE PINE TREE WAS BLOWN DOWN. DO STRUCTURAL DAMAGE WAS REPORTED.
Jan 17, 1:52 AM CST	HAIL 0.88	Maryland Heights, MO	NEAR INTERSECTION OF PAGE AND LINDBERGH.
Jan 17, 1:54 AM CST	HAIL 0.7	Creve Coeur, MO
Jan 17, 1:57 AM CST	HAIL 0.25	1 Ssw Hazelwood, MO	OBSERVATION FROM LAMBERT AIRPORT.
Jan 17, 1:58 AM CST	HAIL 0.25	St. Ann, MO
Jan 17, 2:02 AM CST	HAIL 0.25	Ferguson, MO
Jan 17, 2:05 AM CST	HAIL 0.25	Brentwood, MO
Jan 17, 2:08 AM CST	HAIL 0.5	Clayton, 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
Jan 16, 11:47 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 7.4 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-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: 2 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 748 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 431 m²/s²
0-3 km storm-relative helicity: 500 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.

496 
WUUS53 KLSX 170723
SVRLSX
ILC013-MOC183-189-170800-
/O.NEW.KLSX.SV.W.0004.120117T0723Z-120117T0800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
123 AM CST TUE JAN 17 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN CALHOUN COUNTY IN SOUTHWEST ILLINOIS...
  ST. CHARLES COUNTY IN EAST CENTRAL MISSOURI...
  NORTHERN ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 200 AM CST

* AT 118 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  NEW MELLE...OR 10 MILES NORTHEAST OF WASHINGTON...AND MOVING EAST
  AT 55 MPH.

  AT 118 AM CST...NICKEL SIZE HAIL WAS REPORTED IN DUTZOW.

* LOCATIONS IMPACTED INCLUDE...
  LAKE ST. LOUIS...WILDWOOD...DARDENNE PRAIRIE...O'FALLON...WELDON
  SPRING...COTTLEVILLE...ELLISVILLE...CLARKSON VALLEY...
  CHESTERFIELD...BALLWIN...ST. PETERS...TOWN AND COUNTRY...ST.   
  CHARLES...MARYLAND HEIGHTS...RIDGETON AND OLIVETTE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

&&

LAT...LON 3880 9012 3878 9018 3875 9019 3872 9025
      3862 9031 3857 9073 3863 9074 3860 9077
      3855 9091 3868 9097 3873 9097 3897 9047
      3896 9039 3892 9030 3892 9026 3885 9011
TIME...MOT...LOC 0721Z 252DEG 50KT 3866 9083
WIND...HAIL 60MPH 1.00IN

$$

BRITT

3 follow-up statements

180 
WWUS53 KLSX 170736
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
136 AM CST TUE JAN 17 2012

ILC013-MOC183-189-170800-
/O.CON.KLSX.SV.W.0004.000000T0000Z-120117T0800Z/
CALHOUN IL-ST. CHARLES MO-ST. LOUIS MO-
136 AM CST TUE JAN 17 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN ST.
LOUIS...ST. CHARLES AND SOUTHERN CALHOUN COUNTIES UNTIL 200 AM CST...

AT 132 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
WELDON SPRING...MOVING EAST AT 60 MPH. QUARTER SIZE HAIL MAY ALSO
ACCOMPANY THESE DAMAGING WINDS.

AT 132 AM CST...HALF INCH DIAMETER HAIL WAS OBSERVED AT THE NATIONAL 
WEATHER SERVICE OFFICE IN WELDON SPRING.

LOCATIONS IMPACTED INCLUDE...
  CLARKSON VALLEY...COTTLEVILLE...BALLWIN...CHESTERFIELD...ST.
  PETERS...TOWN AND COUNTRY...ST. CHARLES...MARYLAND HEIGHTS...CREVE
  COEUR...FRONTENAC...LADUE...OLIVETTE...BRIDGETON...BRENTWOOD...ST.
  ANN...OVERLAND...RICHMOND HEIGHTS...CLAYTON...UNIVERSITY CITY AND
  WOODSON TERRACE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

&&

LAT...LON 3880 9012 3878 9018 3875 9019 3872 9025
      3862 9031 3857 9073 3863 9074 3860 9077
      3855 9091 3868 9097 3873 9097 3897 9047
      3896 9039 3892 9030 3892 9026 3885 9011
TIME...MOT...LOC 0735Z 248DEG 50KT 3869 9065
WIND...HAIL 60MPH 1.00IN

$$

BRITT

084 
WWUS53 KLSX 170748
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
148 AM CST TUE JAN 17 2012

ILC013-170757-
/O.CAN.KLSX.SV.W.0004.000000T0000Z-120117T0800Z/
CALHOUN IL-
148 AM CST TUE JAN 17 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN CALHOUN COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 3880 9012 3878 9018 3874 9020 3872 9025
      3865 9030 3862 9031 3857 9073 3864 9074
      3888 9055 3892 9049 3896 9047 3896 9039
      3892 9030 3892 9026 3885 9011
TIME...MOT...LOC 0747Z 249DEG 50KT 3875 9045

$$

MOC183-189-170800-
/O.CON.KLSX.SV.W.0004.000000T0000Z-120117T0800Z/
ST. CHARLES MO-ST. LOUIS MO-
148 AM CST TUE JAN 17 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN ST.
LOUIS AND EASTERN ST. CHARLES COUNTIES UNTIL 200 AM CST...

AT 144 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
MARYLAND HEIGHTS...MOVING EAST AT 55 MPH. QUARTER SIZE HAIL MAY ALSO
ACCOMPANY THESE DAMAGING WINDS.

LOCATIONS IMPACTED INCLUDE...
  BRIDGETON...OLIVETTE...BRENTWOOD...ST. ANN...OVERLAND...RICHMOND
  HEIGHTS...CLAYTON...UNIVERSITY CITY...WOODSON TERRACE...LAMBERT
  FIELD...ST. JOHN...HAZELWOOD...BEL-RIDGE...BERKELEY...KINLOCH...
  NORMANDY...HILLSDALE...COOL VALLEY...NORTHWOODS AND FLORISSANT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

&&

LAT...LON 3880 9012 3878 9018 3874 9020 3872 9025
      3865 9030 3862 9031 3857 9073 3864 9074
      3888 9055 3892 9049 3896 9047 3896 9039
      3892 9030 3892 9026 3885 9011
TIME...MOT...LOC 0747Z 249DEG 50KT 3875 9045
WIND...HAIL 60MPH 1.00IN

$$

BRITT

079 
WWUS53 KLSX 170757
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
157 AM CST TUE JAN 17 2012

MOC183-189-170806-
/O.EXP.KLSX.SV.W.0004.000000T0000Z-120117T0800Z/
ST. CHARLES MO-ST. LOUIS MO-
157 AM CST TUE JAN 17 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN ST. LOUIS AND EASTERN
ST. CHARLES COUNTIES WILL EXPIRE AT 200 AM CST...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND IS NO LONGER 
CONSIDERED SEVERE.  HOWEVER...THIS LINE OF STRONG THUNDERSTORMS MAY 
STILL PRODUCE WIND GUSTS TO 50 MPH AND NICKEL SIZE HAIL AS IT MOVES 
ACROSS NORTH ST. LOUIS COUNTY AND FAR EASTERN ST. CHARLES COUNTY 
BETWEEN NOW AND 230 AM CST.

IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 700 AM CST.

LAT...LON 3880 9012 3878 9018 3874 9020 3872 9025
      3865 9030 3862 9031 3857 9073 3864 9074
      3888 9055 3892 9049 3896 9047 3896 9039
      3892 9030 3892 9026 3885 9011
TIME...MOT...LOC 0756Z 249DEG 50KT 3879 9030

$$

BRITT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jan 16, 11:59 PM CST	Severe Thunderstorm Warning	LSX	Callaway, Cole, Gasconade, Montgomery, Osage	58 days
Jan 17, 12:39 AM CST	Tornado Warning	LSX	Gasconade, Osage	36 min
Jan 17, 12:55 AM CST	Severe Thunderstorm Warning	LSX	Lincoln, Saint Charles, Warren	35 min
Jan 17, 1:14 AM CST	Severe Thunderstorm Warning	LSX	Franklin, Gasconade	31 min
Jan 17, 1:39 AM CST	Tornado Warning	LSX	Franklin, Jefferson	36 min
Jan 17, 1:41 AM CST	Tornado Warning	LSX	Crawford, Franklin	34 min
Jan 17, 2:08 AM CST	Severe Thunderstorm Warning	LSX	Jefferson, Saint Louis, City of Saint Louis	37 min
Jan 17, 2:12 AM CST	Tornado Warning	LSX	Franklin, Jefferson, Washington	33 min
Jan 17, 2:35 AM CST	Tornado Warning	LSX	Jefferson, Saint Louis	40 min
Jan 17, 4:18 AM CST	Severe Thunderstorm Warning	LSX	Crawford	27 min
Jan 17, 4:34 AM CST	Areal Flood Advisory	LSX	Cole, Crawford, Franklin, Gasconade, Jefferson, Saint Charles and 3 more	60 days
Jan 17, 5:22 AM CST	Severe Thunderstorm Warning	LSX	Jefferson, Sainte Genevieve	38 min
Jan 17, 6:01 AM CST	Severe Thunderstorm Warning	LSX	Iron, Sainte Genevieve, Saint Francois, Washington	44 min
Jan 17, 6:25 AM CST	Severe Thunderstorm Warning	LSX	Iron, Madison, Reynolds, Saint Francois	50 min
Jan 17, 2:17 AM CST	Severe Thunderstorm Warning	LSX	Madison	28 min
Jan 17, 2:38 AM CST	Severe Thunderstorm Warning	LSX	Clinton, Madison, Saint Clair	52 min
Jan 17, 2:39 AM CST	Severe Thunderstorm Warning	LSX	Bond	36 min
Jan 17, 3:07 AM CST	Tornado Warning	LSX	Clinton, Monroe, Saint Clair, Washington	38 min
Jan 17, 3:23 AM CST	Severe Thunderstorm Warning	LSX	Clinton, Marion	35 min
Jan 17, 3:46 AM CST	Tornado Warning	LSX	Clinton, Washington	29 min
Jan 17, 5:14 AM CST	Severe Thunderstorm Warning	LSX	Bond, Clinton, Madison, Saint Clair	46 min
Jan 17, 5:47 AM CST	Severe Thunderstorm Warning	LSX	Clinton, Fayette, Marion	43 min
Jan 17, 5:53 AM CST	Severe Thunderstorm Warning	LSX	Monroe, Randolph, Saint Clair, Washington	52 min
Jan 17, 6:35 AM CST	Severe Thunderstorm Warning	LSX	Randolph	25 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2012 Severe Thunderstorm Warnings in Illinois, 2012 Every severe thunderstorm warning in 2012

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.