Alert archive / Missouri / Tornado Warnings in 2010

Tornado Warning 33, NWS St. Louis, MO

April 30, 2010Jefferson County, Saint Louis County, Missouri; Monroe County, Illinois

NWS St. Louis, MO issued this tornado warning at Apr 30, 2010, 8:21 PM CDT for Jefferson County, Saint Louis County, Missouri; Monroe County, Illinois. It was in force for 39 min. 9 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 30, 2010, 8:21 PM CDT (01:21 UTC)
Expired: Apr 30, 2010, 9:00 PM CDT
In force: 39 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon

Counties Monroe County, IL, Jefferson County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 42 km from the middle of the area, began a volume at 01:25 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 30, 8:27 PM CDT	TORNADO	5 Nw Hillsboro, MO	SIGNIFICANT TREE DAMAGE....SOME TREES SNAPPED OFF...POLE BARN DESTROYED.
Apr 30, 8:29 PM CDT	TORNADO	Morse Mill, MO	STRUCTURAL DAMAGE AT BAPTIST CHURCH ON HIGHWAY B...JUST NORTH OF BIG RIVER. TIME ESTIMATED FROM RADAR.
Apr 30, 8:30 PM CDT	TORNADO	1 Ne Morse Mill, MO	FALLING TREES DAMAGED SEVERAL HOUSES ALONG KLONDIKE ROAD. ONE HOMEOWNER BRIEFLY TRAPPED BY THE FALLEN TREE.
Apr 30, 8:30 PM CDT	TORNADO	2 Ne Hillsboro, MO	A TREE FELL ONTO A HOME CAUSING SIGNIFICANT DAMAGE....TIME ESTIMATED....
Apr 30, 8:30 PM CDT	TORNADO	4 Se Cedar Hill, MO	POWER LINES AND TREES ARE DOWN AROUND LAKE TISHOMINGO...AND POWER IS OUT IN THE AREA
Apr 30, 8:38 PM CDT	TORNADO	1 Sw Otto, MO	SEVERAL HOMES DAMAGED...ALSO WIRES DOWN.
Apr 30, 8:40 PM CDT	TORNADO	6 Nne Otto, MO	....TIME ESTIMATED...
Apr 30, 8:49 PM CDT	TORNADO	2 Ne Hillsboro, MO	A TREE FELL ONTO A HOME CAUSING SIGNIFICANT DAMAGE
Apr 30, 9:00 PM CDT	TSTM WND GST 70	4 S Columbia, IL

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 30, 2:40 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 1.4 hours before the alert went out and 243 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: 1090 J/kg
Mixed-layer CIN: -60 J/kg
Mixed-layer LCL: 718 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 340 m²/s²
0-3 km storm-relative helicity: 345 m²/s²
Significant tornado parameter: 1.7
Supercell composite: 10.4

Open this sounding in Storm Lab

The text

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

506 
WFUS53 KLSX 010121
TORLSX
ILC133-MOC099-189-010200-
/O.NEW.KLSX.TO.W.0033.100501T0121Z-100501T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
821 PM CDT FRI APR 30 2010

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN MONROE COUNTY IN SOUTHWEST ILLINOIS...
  JEFFERSON COUNTY IN EAST CENTRAL MISSOURI...
  SOUTH CENTRAL ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 900 PM CDT

* AT 815 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 7 MILES SOUTH OF DITTMER...OR 8 MILES WEST OF
  HILLSBORO...AND MOVING NORTHEAST AT 45 MPH.

* LOCATIONS IMPACTED INCLUDE...
  HILLSBORO...CEDAR HILL...HERCULANEUM...BYRNES MILL...PEVELY...
  ANTONIA...BARNHART...HIGH RIDGE...MURPHY...ARNOLD...VALLEY PARK...
  FENTON...OAKVILLE...SUNSET HILLS...WATERLOO...DES PERES...
  KIRKWOOD...CRESTWOOD...MEHLVILLE AND OAKLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

TORNADOES ARE DIFFICULT TO SEE AND CONFIRM AT NIGHT. TAKE COVER NOW.

&&

LAT...LON 3836 9007 3813 9068 3823 9078 3838 9075
      3866 9036 3861 9031 3858 9032 3855 9027
      3852 9026 3842 9014 3841 9014
TIME...MOT...LOC 0121Z 228DEG 38KT 3827 9065

$$

KANOFSKY

2 follow-up statements

259 
WWUS53 KLSX 010134
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
834 PM CDT FRI APR 30 2010

ILC133-MOC099-189-010200-
/O.CON.KLSX.TO.W.0033.000000T0000Z-100501T0200Z/
MONROE IL-JEFFERSON MO-ST. LOUIS MO-
834 PM CDT FRI APR 30 2010

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL ST. LOUIS...
JEFFERSON AND NORTHERN MONROE COUNTIES UNTIL 900 PM CDT...

AT 829 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR CEDAR HILL...MOVING NORTHEAST AT 40 MPH.

THIS IS AN EXTREMELY DANGEROUS STORM. THERE ARE STRONG RADAR 
INDICATIONS OF A RAIN-WRAPPED TORNADO ON THE GROUND PRODUCING 
DAMAGE. DO NOT ATTEMPT TO SPOT THIS TORNADO. TAKE COVER NOW!

LOCATIONS IMPACTED INCLUDE...
  BYRNES MILL...HERCULANEUM...ANTONIA...PEVELY...HIGH RIDGE...
  BARNHART...MURPHY...ARNOLD...VALLEY PARK...FENTON...SUNSET HILLS...
  OAKVILLE...DES PERES...KIRKWOOD...CRESTWOOD...MEHLVILLE...
  OAKLAND...WATERLOO...LAKESHIRE AND LEMAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR
THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3813 9068 3838 9075 3866 9036 3861 9031
      3858 9032 3855 9027 3852 9026 3842 9014
      3841 9014 3836 9007
TIME...MOT...LOC 0133Z 235DEG 35KT 3833 9056

$$

KANOFSKY

916 
WWUS53 KLSX 010142
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
842 PM CDT FRI APR 30 2010

ILC133-MOC099-189-010200-
/O.CON.KLSX.TO.W.0033.000000T0000Z-100501T0200Z/
MONROE IL-JEFFERSON MO-ST. LOUIS MO-
842 PM CDT FRI APR 30 2010

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL ST. LOUIS...
JEFFERSON AND NORTHERN MONROE COUNTIES UNTIL 900 PM CDT...

AT 838 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR ANTONIA...MOVING NORTHEAST AT 40 MPH.

TRAINED SPOTTERS HAVE REPORTED LARGE TREES UPROOTED AND SNAPPED 
ALONG WITH DAMAGE TO A BARN BETWEEN CEDAR HILL AND HILLSBORO. THIS 
IS AN EXTREMELY DANGEROUS STORM. 

THERE ARE STRONG RADAR INDICATIONS OF A RAIN-WRAPPED TORNADO ON THE 
GROUND PRODUCING DAMAGE. DO NOT ATTEMPT TO SPOT THIS TORNADO. TAKE 
COVER NOW! 

LOCATIONS IMPACTED INCLUDE...
  HIGH RIDGE...BARNHART...MURPHY...ARNOLD...VALLEY PARK...FENTON...
  SUNSET HILLS...OAKVILLE...DES PERES...KIRKWOOD...CRESTWOOD...
  OAKLAND...MEHLVILLE...WATERLOO...COLUMBIA...LEMAY...LAKESHIRE...
  AFFTON...SHREWSBURY AND WEBSTER GROVES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR
THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3813 9068 3838 9075 3866 9036 3861 9031
      3858 9032 3855 9027 3852 9026 3842 9014
      3841 9014 3836 9007
TIME...MOT...LOC 0141Z 235DEG 35KT 3837 9047

$$

KANOFSKY

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 30, 7:40 PM CDT	Tornado Warning	LSX	Crawford, Franklin, Jefferson, Washington	50 min
Apr 30, 7:45 PM CDT	Flash Flood Warning	LSX	Crawford	6 hr
Apr 30, 7:55 PM CDT	Tornado Warning	LSX	Jefferson, Saint Francois, Washington	50 min
Apr 30, 8:07 PM CDT	Tornado Warning	LSX	Reynolds	38 min
Apr 30, 8:14 PM CDT	Flash Flood Warning	LSX	Franklin, Jefferson, Washington	6 hr
Apr 30, 8:39 PM CDT	Flash Flood Warning	LSX	Saint Louis, City of Saint Louis	6 hr
Apr 30, 8:43 PM CDT	Tornado Warning	LSX	Iron, Reynolds	47 min
Apr 30, 8:54 PM CDT	Tornado Warning	LSX	Jefferson, Saint Louis, City of Saint Louis	51 min
Apr 30, 9:02 PM CDT	Tornado Warning	LSX	Jefferson, Sainte Genevieve	29 min
Apr 30, 9:10 PM CDT	Tornado Warning	LSX	Iron, Madison	50 min
Apr 30, 9:23 PM CDT	Tornado Warning	LSX	Sainte Genevieve, Saint Francois	37 min
Apr 30, 9:51 PM CDT	Tornado Warning	LSX	Sainte Genevieve	39 min
May 1, 3:54 AM CDT	Flash Flood Watch	LSX	Crawford, Iron, Jefferson, Madison, Reynolds, Sainte Genevieve and 2 more	23 hr
Apr 30, 9:25 PM CDT	Tornado Warning	LSX	Clinton, Madison, Saint Clair, Washington	34 min

Nearby

Tornado Warnings in Missouri, 2010 Tornado Warnings in Illinois, 2010 Every tornado warning in 2010 Tornadoes in 2010

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.