Alert archive / Missouri / Tornado Watches in 2001
Tornado Watch 135
The Storm Prediction Center issued this tornado watch at Apr 11, 2001, 1:00 PM CDT for 16 counties in Illinois; 26 counties in Missouri. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 11, 2001, 1:00 PM CDT (18:00 UTC)
- Expired
- Apr 11, 2001, 7:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 42 counties
Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, McDonough County, IL, Morgan County, IL, Pike County, IL, Saint Clair County, IL, Schuyler County, IL, Scott County, IL, Adair County, MO, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Clark County, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Macon County, MO, Marion County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Saint Charles County, MO, Saint Louis County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Warren County, MO
The radar
The St Louis radar (KLSX), 110 km from the middle of the area, began a volume at 18:00 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.
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 6.0 hours before the alert went out and 214 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.
- Mixed-layer CAPE
- 732 J/kg
- Mixed-layer CIN
- -137 J/kg
- Mixed-layer LCL
- 716 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 326 m²/s²
- 0-3 km storm-relative helicity
- 368 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.5
The text
As transmitted, in the capitals the NWS used until 2016.
000 WWUS9 KMKC 111745 SEL5 SEL5 MKC WW 111740 ILZ000-MOZ000-120000- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 135 STORM PREDICTION CENTER NORMAN OK 1240 PM CDT WED APR 11 2001 THE STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF WEST CENTRAL ILLINOIS NORTHEAST MISSOURI EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 100 PM UNTIL 700 PM CDT. ...THIS IS A PARTICULARLY DANGEROUS SITUATION... DAMAGING TORNADOES...LARGE HAIL TO 3 INCHES IN DIAMETER... THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS ALONG AND 70 STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH NORTHWEST OF QUINCY ILLINOIS TO 45 MILES SOUTHWEST OF SAINT LOUIS MISSOURI. REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. OTHER WATCH INFORMATION... CONTINUE...WW 131...WW 132...WW 133...WW 134... DISCUSSION...SEVERE THUNDERSTORMS WILL RAPIDLY DEVELOP ALONG AND AHEAD OF COLD FRONT MOVING INTO WRN MO. VERY STRONG COUPLED JET WITH 500MB WINDS OF 100 KT AND 850 MB WINDS OF 60-70KT WILL ROTATE ACROSS NERN MO INTO IL DURING AFTERNOON. WITH CAPES APPROACHING 2000 J/KG...INSTABILITY IS AVAILABLE FOR DEVELOPMENT OF TORNADO SUPERCELLS. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS. A FEBW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 22050. ...HALES ;403,0901 381,0894 381,0921 403,0925;
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 10, 7:00 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Calhoun, Clay, Clinton, Crawford, Edwards and 21 more | 5 hr |
| Apr 11, 12:00 PM CDT | Tornado Watch | SPC | Henderson | 5 hr |
| Apr 11, 4:00 PM CDT | Tornado Watch | SPC | Bureau, Carroll, Ford, Henderson, Henry, Jo Daviess and 16 more | 6 hr |
| Apr 11, 2:00 AM CDT | Tornado Watch | SPC | Atchison | 5 hr |
| Apr 11, 4:00 AM CDT | Severe Thunderstorm Watch | SPC | Andrew, Buchanan, Caldwell, Daviess, DeKalb, Gentry and 10 more | 5 hr |
| Apr 11, 6:15 AM CDT | Tornado Watch | SPC | Barry, McDonald, Newton, Stone | 6 hr |
| Apr 11, 9:30 AM CDT | Tornado Watch | SPC | Andrew, Barton, Bates, Benton, Buchanan, Caldwell and 47 more | 6 hr |
| Apr 11, 10:00 AM CDT | Severe Thunderstorm Watch | SPC | Butler, Carter, Douglas, Howell, Oregon, Ozark and 2 more | 5 hr |
| Apr 11, 10:45 AM CDT | Tornado Watch | SPC | Atchison, Gentry, Grundy, Harrison, Holt, Nodaway and 1 more | 5 hr |
Nearby
Tornado Watches in Missouri, 2001Tornado Watches in Illinois, 2001Every tornado watch in 2001
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.