Alert archive / Iowa / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 135
The Storm Prediction Center issued this severe thunderstorm watch at Apr 9, 2017, 9:01 PM CDT for 11 counties in Iowa; 6 counties in Minnesota; 9 counties in Wisconsin. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 9, 2017, 9:01 PM CDT (02:01 UTC)
- Expired
- Apr 10, 2017, 1:00 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 26 counties
Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Floyd County, IA, Franklin County, IA, Hancock County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Fillmore County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Jackson County, WI, Pepin County, WI, Taylor County, WI, Trempealeau County, WI
The radar
The La Crosse radar (KARX), 110 km from the middle of the area, began a volume at 02:01 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
- 10%
- 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
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
19 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 9:09 PM CDT | Severe Thunderstorm Warning | ARX | Olmsted, Wabasha | 40 min |
| Apr 9, 9:20 PM CDT | Severe Thunderstorm Warning | ARX | Mitchell | 55 min |
| Apr 9, 9:28 PM CDT | Severe Thunderstorm Warning | ARX | Olmsted, Wabasha, Winona | 47 min |
| Apr 9, 9:30 PM CDT | Severe Thunderstorm Warning | MPX | Chippewa, Dunn | 30 min |
| Apr 9, 9:51 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Worth | 9 min |
| Apr 9, 9:57 PM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Floyd, Howard, Mitchell | 48 min |
| Apr 9, 10:11 PM CDT | Severe Thunderstorm Warning | ARX | Buffalo | 49 min |
| Apr 9, 10:15 PM CDT | Severe Thunderstorm Warning | ARX | Fillmore, Mower | 45 min |
| Apr 9, 10:21 PM CDT | Severe Thunderstorm Warning | ARX | Olmsted, Wabasha | 39 min |
| Apr 9, 10:25 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Worth | 23 min |
| Apr 9, 10:33 PM CDT | Severe Thunderstorm Warning | ARX | Trempealeau | 57 min |
| Apr 9, 10:41 PM CDT | Severe Thunderstorm Warning | ARX | Taylor | 64 min |
| Apr 9, 10:50 PM CDT | Severe Thunderstorm Warning | ARX | Winona | 40 min |
| Apr 9, 11:04 PM CDT | Severe Thunderstorm Warning | ARX | Buffalo | 41 min |
| Apr 9, 11:12 PM CDT | Severe Thunderstorm Warning | ARX | Clark, Jackson | 63 min |
| Apr 9, 11:31 PM CDT | Severe Thunderstorm Warning | ARX | Wabasha | 24 min |
| Apr 9, 11:37 PM CDT | Severe Thunderstorm Warning | ARX | Jackson, Trempealeau | 53 min |
| Apr 9, 11:44 PM CDT | Severe Thunderstorm Warning | ARX | Clark | 60 min |
| Apr 9, 11:58 PM CDT | Severe Thunderstorm Warning | ARX | Clark, Jackson | 47 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
Minneapolis, MN (KMPX), launched 00:00Z, 2.0 hours before the alert went out and 127 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
- 1596 m above ground
- 0-6 km bulk shear
- 59 kt
- 0-1 km storm-relative helicity
- 173 m²/s²
- 0-3 km storm-relative helicity
- 450 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 8:06 PM CDT | Mesoscale Discussion | SPC | Cerro Gordo, Chickasaw, Floyd, Franklin, Hancock, Howard and 4 more | 54 min |
| Apr 9, 10:28 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Clarke, Decatur, Lucas and 9 more | 2 hr |
| Apr 9, 11:28 PM CDT | Severe Thunderstorm Watch | SPC | Appanoose, Clarke, Davis, Decatur, Lucas, Mahaska and 7 more | 4 hr |
| Apr 10, 1:53 AM CDT | Mesoscale Discussion | SPC | Appanoose, Cedar, Clinton, Davis, Des Moines, Henry and 15 more | 2 hr |
| Apr 9, 11:32 PM CDT | Mesoscale Discussion | SPC | Dodge, Fillmore, Houston, Mower, Olmsted, Wabasha and 1 more | 58 min |
| Apr 10, 12:01 AM CDT | Severe Thunderstorm Watch | SPC | Florence, Forest, Langlade, Lincoln, Marathon, Oneida and 3 more | 3 hr |
| Apr 10, 2:16 AM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calumet, Columbia, Crawford, Dane and 26 more | 119 min |
| Apr 10, 11:57 AM CDT | Mesoscale Discussion | SPC | Kenosha, Milwaukee, Racine, Walworth | 3 hr |
| Apr 10, 1:48 PM CDT | Severe Thunderstorm Watch | SPC | Dane, Dodge, Green, Jefferson, Kenosha, Lafayette and 7 more | 8 hr |
| Apr 10, 3:25 PM CDT | Mesoscale Discussion | SPC | Jefferson, Kenosha, Milwaukee, Racine, Rock, Walworth and 1 more | 2 hr |
| Apr 10, 6:22 PM CDT | Mesoscale Discussion | SPC | Kenosha, Racine | 53 min |
Nearby
Severe Thunderstorm Watches in Iowa, 2017Severe Thunderstorm Watches in Wisconsin, 2017Severe Thunderstorm Watches in Minnesota, 2017Every severe thunderstorm watch in 2017
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.