Alert archive / Iowa / Severe Thunderstorm Watches in 2015
Severe Thunderstorm Watch 331
The Storm Prediction Center issued this severe thunderstorm watch at Jun 22, 2015, 8:08 AM CDT for Carroll County, Jo Daviess County, Stephenson County, Illinois; 11 counties in Iowa; 5 counties in Wisconsin. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 22, 2015, 8:08 AM CDT (13:08 UTC)
- Expired
- Jun 22, 2015, 11:45 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Benton County, IA, Buchanan County, IA, Cedar County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Iowa County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Carroll County, IL, Jo Daviess County, IL, Stephenson County, IL, Dane County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Sauk County, WI
The radar
The Quad Cities radar (KDVN), 118 km from the middle of the area, began a volume at 13:09 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
- 10%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 22, 8:09 AM CDT | Severe Thunderstorm Warning | DVN | Buchanan | 51 min |
| Jun 22, 8:34 AM CDT | Severe Thunderstorm Warning | DVN | Delaware, Dubuque | 41 min |
| Jun 22, 8:44 AM CDT | Severe Thunderstorm Warning | DVN | Benton, Linn | 46 min |
| Jun 22, 9:00 AM CDT | Severe Thunderstorm Warning | DVN | Carroll, Jo Daviess | 60 min |
| Jun 22, 9:00 AM CDT | Severe Thunderstorm Warning | MKX | Columbia, Dane, Green, Iowa, Lafayette, Rock and 1 more | 60 min |
| Jun 22, 9:26 AM CDT | Severe Thunderstorm Warning | DVN | Carroll, Stephenson | 48 min |
| Jun 22, 9:58 AM CDT | Severe Thunderstorm Warning | MKX | Columbia, Dane, Dodge, Green, Iowa, Jefferson and 4 more | 62 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
Davenport, (KDVN), launched 12:00Z, 1.1 hours before the alert went out and 119 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
- 1240 J/kg
- Mixed-layer CIN
- -232 J/kg
- Mixed-layer LCL
- 853 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 95 m²/s²
- 0-3 km storm-relative helicity
- 66 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
961 WWUS20 KWNS 221306 SEL1 SPC WW 221306 IAZ000-ILZ000-WIZ000-221800- URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 331 NWS STORM PREDICTION CENTER NORMAN OK 810 AM CDT MON JUN 22 2015 THE NWS STORM PREDICTION CENTER HAS ISSUED A * SEVERE THUNDERSTORM WATCH FOR PORTIONS OF EASTERN IOWA FAR NORTHWEST ILLINOIS SOUTHWEST AND SOUTH-CENTRAL WISCONSIN * EFFECTIVE THIS MONDAY MORNING AND AFTERNOON FROM 810 AM UNTIL 100 PM CDT. * PRIMARY THREATS INCLUDE... ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE SUMMARY...A MATURE MCS WITH A HISTORY OF WIND DAMAGE WILL CONTINUE EAST ACROSS THE WATCH AREA THIS MORNING WITH A RISK FOR DAMAGING WINDS AND SEVERE HAIL. THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES WEST OF CEDAR RAPIDS IOWA TO 20 MILES NORTHEAST OF MADISON WISCONSIN. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES. && OTHER WATCH INFORMATION...CONTINUE...WW 328...WW 329...WW 330... AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 28040. ...MEAD
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 7:08 PM CDT | Mesoscale Discussion | SPC | Franklin, Gallatin, Hamilton, Hardin, Jackson, Jefferson and 6 more | 67 min |
| Jun 22, 7:42 AM CDT | Mesoscale Discussion | SPC | Carroll, Jo Daviess, Stephenson, Whiteside | 93 min |
| Jun 22, 9:14 AM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Cook, DeKalb, DuPage, Grundy and 11 more | 61 min |
| Jun 22, 9:39 AM CDT | Severe Thunderstorm Watch | SPC | Boone, Bureau, Cook, DeKalb, DuPage, Ford and 19 more | 3 hr |
| Jun 22, 11:00 AM CDT | Mesoscale Discussion | SPC | Bureau, Cook, DeKalb, DuPage, Grundy, Henry and 11 more | 2 hr |
| Jun 22, 1:22 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Carroll, Cass, Fulton and 21 more | 113 min |
| Jun 22, 3:56 PM CDT | Tornado Watch | SPC | Bureau, Carroll, Cass, Champaign, Coles, DeKalb and 34 more | 9 hr |
| Jun 22, 6:08 PM CDT | Mesoscale Discussion | SPC | Bureau, DeWitt, Fulton, Grundy, Hancock, Henderson and 21 more | 67 min |
| Jun 22, 2:25 AM CDT | Severe Thunderstorm Watch | SPC | Clay, Dickinson, Lyon, O'Brien, Osceola, Sioux | 6 hr |
| Jun 22, 3:10 AM CDT | Mesoscale Discussion | SPC | Benton, Black Hawk, Bremer, Buchanan, Butler, Cerro Gordo and 16 more | 95 min |
| Jun 22, 4:53 AM CDT | Mesoscale Discussion | SPC | Allamakee, Cerro Gordo, Chickasaw, Clay, Clayton, Dickinson and 15 more | 2 hr |
| Jun 22, 5:33 AM CDT | Severe Thunderstorm Watch | SPC | Black Hawk, Boone, Bremer, Butler, Cerro Gordo, Emmet and 15 more | 6 hr |
| Jun 22, 6:03 AM CDT | Severe Thunderstorm Watch | SPC | Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more | 4 hr |
| Jun 22, 2:50 PM CDT | Mesoscale Discussion | SPC | Barron, Burnett, Douglas, Polk, Saint Croix, Washburn | 55 min |
| Jun 22, 4:48 PM CDT | Severe Thunderstorm Watch | SPC | Ashland, Bayfield, Burnett, Douglas, Florence, Forest and 7 more | 4 hr |
Nearby
Severe Thunderstorm Watches in Iowa, 2015Severe Thunderstorm Watches in Wisconsin, 2015Severe Thunderstorm Watches in Illinois, 2015Every severe thunderstorm watch in 2015
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.