Alert archive / Illinois / Tornado Watches in 2009
Tornado Watch 306
The Storm Prediction Center issued this tornado watch at May 15, 2009, 2:39 PM CDT for 39 counties in Illinois; 5 counties in Missouri. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- May 15, 2009, 2:39 PM CDT (19:39 UTC)
- Expired
- May 15, 2009, 10:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
All 44 counties
Bond County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clinton County, IL, Coles County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Fayette County, IL, Ford County, IL, Fulton County, IL, Greene County, IL, Iroquois County, IL, Jersey County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Vermilion County, IL, Washington County, IL, Woodford County, IL, City of Saint Louis, MO, Franklin County, MO, Jefferson County, MO, Saint Charles County, MO, Saint Louis County, MO
The radar
The Lincoln radar (KILX), 83 km from the middle of the area, began a volume at 19:40 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 50%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
34 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 15, 3:32 PM CDT | Flash Flood Warning | ILX | Fulton, Schuyler | 6 hr |
| May 15, 3:45 PM CDT | Tornado Warning | ILX | Cass, Morgan, Scott | 45 min |
| May 15, 4:17 PM CDT | Flash Flood Warning | ILX | Marshall, Peoria, Tazewell, Woodford | 6 hr |
| May 15, 4:25 PM CDT | Tornado Warning | ILX | Cass, Morgan | 35 min |
| May 15, 4:49 PM CDT | Tornado Warning | ILX | Cass, Menard, Sangamon | 26 min |
| May 15, 5:14 PM CDT | Tornado Warning | ILX | Logan, Menard, Sangamon | 46 min |
| May 15, 5:40 PM CDT | Tornado Warning | ILX | Logan, Macon, Sangamon | 50 min |
| May 15, 5:46 PM CDT | Flash Flood Warning | ILX | McLean, Tazewell, Woodford | 5 hr |
| May 15, 5:46 PM CDT | Flash Flood Warning | LOT | Cook, DuPage, Ford, Grundy, Iroquois, Kankakee and 4 more | 6 hr |
| May 15, 5:54 PM CDT | Flash Flood Warning | ILX | Cass, Logan, Mason, Menard, Morgan, Sangamon and 2 more | 6 hr |
| May 15, 5:58 PM CDT | Severe Thunderstorm Warning | ILX | Cass, Morgan, Scott | 47 min |
| May 15, 6:06 PM CDT | Severe Thunderstorm Warning | ILX | Champaign, Vermilion | 54 min |
| May 15, 6:06 PM CDT | Tornado Warning | LSX | Calhoun, Greene, Jersey, Pike | 39 min |
| May 15, 6:09 PM CDT | Severe Thunderstorm Warning | LOT | Ford, Iroquois | 66 min |
| May 15, 6:09 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Greene, Jersey, Pike | 51 min |
| May 15, 6:11 PM CDT | Tornado Warning | ILX | Macon | 35 min |
| May 15, 6:26 PM CDT | Severe Thunderstorm Warning | ILX | Logan, Menard, Sangamon | 30 min |
| May 15, 6:27 PM CDT | Flash Flood Warning | ILX | DeWitt, Macon | 6 hr |
| May 15, 6:29 PM CDT | Flash Flood Warning | LSX | Calhoun, Greene | 5 hr |
| May 15, 6:38 PM CDT | Tornado Warning | ILX | Champaign, Vermilion | 31 min |
| May 15, 6:42 PM CDT | Severe Thunderstorm Warning | ILX | Christian, Logan, Sangamon | 48 min |
| May 15, 6:42 PM CDT | Tornado Warning | ILX | Champaign, Macon, Piatt | 48 min |
| May 15, 6:59 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Jersey, Madison, Saint Clair | 46 min |
| May 15, 7:04 PM CDT | Flash Flood Warning | ILX | Champaign, Piatt, Vermilion | 6 hr |
| May 15, 7:04 PM CDT | Severe Thunderstorm Warning | ILX | Christian, Macon, Shelby | 41 min |
| May 15, 7:19 PM CDT | Severe Thunderstorm Warning | ILX | Champaign, Vermilion | 41 min |
| May 15, 7:35 PM CDT | Flash Flood Warning | ILX | Fulton, Knox, Marshall, Peoria, Schuyler, Stark and 2 more | 4 hr |
| May 15, 7:50 PM CDT | Severe Thunderstorm Warning | ILX | Champaign, Vermilion | 40 min |
| May 15, 7:57 PM CDT | Flash Flood Warning | ILX | Christian, Moultrie, Shelby | 6 hr |
| May 15, 8:07 PM CDT | Flash Flood Warning | LOT | Iroquois | 6 hr |
| May 15, 8:18 PM CDT | Flash Flood Warning | ILX | Clark, Coles, Cumberland, Douglas, Edgar | 6 hr |
| May 15, 8:33 PM CDT | Severe Thunderstorm Warning | LSX | Monroe, Saint Clair | 22 min |
| May 15, 8:48 PM CDT | Severe Thunderstorm Warning | ILX | Coles, Cumberland, Moultrie, Shelby | 42 min |
| May 15, 8:55 PM CDT | Severe Thunderstorm Warning | ILX | Edgar, Vermilion | 20 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 7.7 hours before the alert went out and 124 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1235 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 109 m²/s²
- 0-3 km storm-relative helicity
- 242 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 15, 12:50 PM CDT | Tornado Watch | SPC | Adams, Brown, Calhoun, Pike | 7 hr |
| May 15, 2:05 PM CDT | Mesoscale Discussion | SPC | Cass, Champaign, Christian, Coles, Cumberland, DeWitt and 23 more | 25 min |
| May 15, 3:43 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Pike | 62 min |
| May 15, 5:31 PM CDT | Mesoscale Discussion | SPC | Adams, Bond, Brown, Calhoun, Cass, Champaign and 39 more | 119 min |
| May 15, 6:30 PM CDT | Severe Thunderstorm Watch | SPC | Randolph | 6 hr |
| May 15, 2:03 AM CDT | Mesoscale Discussion | SPC | Adair, Andrew, Atchison, Audrain, Boone, Buchanan and 35 more | 87 min |
| May 15, 7:14 AM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Buchanan, Caldwell, Clinton, Daviess and 9 more | 91 min |
| May 15, 7:42 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Andrew, Atchison, Buchanan, Caldwell, Carroll and 29 more | 5 hr |
| May 15, 11:48 AM CDT | Mesoscale Discussion | SPC | Adair, Andrew, Atchison, Buchanan, Caldwell, Carroll and 24 more | 57 min |
| May 15, 3:01 PM CDT | Mesoscale Discussion | SPC | Carroll, Chariton, Clay, Platte, Ray, Saline | 59 min |
Nearby
Tornado Watches in Illinois, 2009Tornado Watches in Missouri, 2009Every tornado watch in 2009
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.