Alert archive / Illinois / Tornado Watches in 2002
Tornado Watch 111
The Storm Prediction Center issued this tornado watch at Apr 18, 2002, 3:00 PM CDT for 17 counties in Illinois; 9 counties in Iowa. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 18, 2002, 3:00 PM CDT (20:00 UTC)
- Expired
- Apr 18, 2002, 8:00 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 26 counties
Cedar County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Jackson County, IA, Jones County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, Henry County, IL, Jo Daviess County, IL, LaSalle County, IL, Lee County, IL, Marshall County, IL, Mercer County, IL, Ogle County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Whiteside County, IL, Winnebago County, IL
The radar
The Quad Cities radar (KDVN), 38 km from the middle of the area, began a volume at 20:13 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.
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 18, 3:04 PM CDT | Severe Thunderstorm Warning | DVN | Jackson | 41 min |
| Apr 18, 3:12 PM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess | 48 min |
| Apr 18, 4:14 PM CDT | Severe Thunderstorm Warning | DVN | Stephenson | 46 min |
| Apr 18, 4:29 PM CDT | Severe Thunderstorm Warning | DVN | Clinton | 31 min |
| Apr 18, 5:28 PM CDT | Severe Thunderstorm Warning | LOT | Ogle | 47 min |
| Apr 18, 5:47 PM CDT | Severe Thunderstorm Warning | DVN | Carroll | 43 min |
| Apr 18, 6:07 PM CDT | Severe Thunderstorm Warning | LOT | Winnebago | 38 min |
| Apr 18, 6:09 PM CDT | Severe Thunderstorm Warning | DVN | Stephenson | 51 min |
| Apr 18, 6:21 PM CDT | Severe Thunderstorm Warning | LOT | Ogle | 39 min |
| Apr 18, 6:49 PM CDT | Severe Thunderstorm Warning | LOT | Winnebago | 36 min |
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 8.0 hours before the alert went out and 34 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
- 1362 J/kg
- Mixed-layer CIN
- -188 J/kg
- Mixed-layer LCL
- 1306 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 126 m²/s²
- 0-3 km storm-relative helicity
- 119 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WWUS20 KWNS 181954 SEL1 SPC WW 181951 IAZ000-ILZ000-190100- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 111 STORM PREDICTION CENTER NORMAN OK 251 PM CDT THU APR 18 2002 THE STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF EASTERN IOWA NORTHERN ILLINOIS EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 300 PM UNTIL 800 PM CDT. TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST NORTHWEST OF MOLINE ILLINOIS TO 25 MILES NORTH OF MARSEILLES ILLINOIS. 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 110... DISCUSSION...RAPIDLY INTENSIFYING THUNDERSTORMS ERN IA IN AXIS OF VERY UNSTABLE AIR MASS. SHEAR PROFILES ARE FAVORABLE FOR SUPERCELLS AND ISOLATED TORNADOES AS STORMS CONTINUE TO DEVELOP AND MOVE INTO NWRN IL. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM MOTION VECTOR 24035. ...HALES 405,0884 405,0912 423,0912 423,0884 WWUS20 KWNS 181954 SEL1 SPC WW 181951 IAZ000-ILZ000-190100- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 111 STORM PREDICTION CENTER NORMAN OK 251 PM CDT THU APR 18 2002 THE STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF EASTERN IOWA NORTHERN ILLINOIS EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 300 PM UNTIL 800 PM CDT. TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST NORTHWEST OF MOLINE ILLINOIS TO 25 MILES NORTH OF MARSEILLES ILLINOIS. 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 110... DISCUSSION...RAPIDLY INTENSIFYING THUNDERSTORMS ERN IA IN AXIS OF VERY UNSTABLE AIR MASS. SHEAR PROFILES ARE FAVORABLE FOR SUPERCELLS AND ISOLATED TORNADOES AS STORMS CONTINUE TO DEVELOP AND MOVE INTO NWRN IL. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM MOTION VECTOR 24035. ...HALES 405,0884 405,0912 423,0912 423,0884
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 18, 1:00 AM CDT | Severe Thunderstorm Watch | SPC | Allamakee, Black Hawk, Bremer, Buchanan, Buena Vista, Butler and 29 more | 6 hr |
| Apr 18, 4:15 PM CDT | Tornado Watch | SPC | Adair, Adams, Allamakee, Audubon, Black Hawk, Boone and 38 more | 5 hr |
Nearby
Tornado Watches in Illinois, 2002Tornado Watches in Iowa, 2002Every tornado watch in 2002
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.