Alert archive / Minnesota / Severe Thunderstorm Watches in 2007
Severe Thunderstorm Watch 676
The Storm Prediction Center issued this severe thunderstorm watch at Sep 20, 2007, 11:13 PM CDT for 10 counties in Minnesota; 8 counties in Wisconsin. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 20, 2007, 11:13 PM CDT (04:13 UTC)
- Expired
- Sep 21, 2007, 6:00 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Aitkin County, MN, Carlton County, MN, Cass County, MN, Cook County, MN, Crow Wing County, MN, Itasca County, MN, Koochiching County, MN, Lake County, MN, Pine County, MN, Saint Louis County, MN, Ashland County, WI, Bayfield County, WI, Burnett County, WI, Douglas County, WI, Iron County, WI, Price County, WI, Sawyer County, WI, Washburn County, WI
The radar
The Duluth radar (KDLH), 35 km from the middle of the area, began a volume at 04:15 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
- 70%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 11:56 PM CDT | Severe Thunderstorm Warning | DLH | Aitkin, Itasca, Saint Louis | 38 min |
| Sep 21, 1:25 AM CDT | Severe Thunderstorm Warning | DLH | Ashland, Bayfield | 20 min |
| Sep 21, 1:50 AM CDT | Severe Thunderstorm Warning | DLH | Cass, Crow Wing | 68 min |
| Sep 21, 5:00 AM CDT | Severe Thunderstorm Warning | DLH | Cass, Itasca | 20 min |
| Sep 21, 5:35 AM CDT | Severe Thunderstorm Warning | DLH | Ashland, Bayfield | 40 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, 4.2 hours before the alert went out and 213 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
- 1394 J/kg
- Mixed-layer CIN
- -85 J/kg
- Mixed-layer LCL
- 838 m above ground
- 0-6 km bulk shear
- 60 kt
- 0-1 km storm-relative helicity
- 192 m²/s²
- 0-3 km storm-relative helicity
- 567 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 24.8
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 8:40 PM CDT | Mesoscale Discussion | SPC | Murray, Nobles, Pipestone, Rock | 95 min |
| Sep 21, 12:00 AM CDT | Tornado Watch | SPC | Becker, Beltrami, Benton, Big Stone, Chippewa, Clay and 28 more | 6 hr |
| Sep 21, 3:08 AM CDT | Mesoscale Discussion | SPC | Aitkin, Carlton, Cook, Itasca, Koochiching, Lake and 2 more | 2 hr |
| Sep 21, 3:29 AM CDT | Mesoscale Discussion | SPC | Becker, Beltrami, Benton, Big Stone, Chippewa, Clay and 27 more | 2 hr |
| Sep 21, 6:04 AM CDT | Severe Thunderstorm Watch | SPC | Aitkin, Anoka, Benton, Carlton, Carver, Cass and 24 more | 5 hr |
| Sep 21, 1:34 PM CDT | Mesoscale Discussion | SPC | Chisago, Cook, Dakota, Dodge, Fillmore, Freeborn and 10 more | 116 min |
| Sep 21, 3:17 PM CDT | Mesoscale Discussion | SPC | Houston | 88 min |
| Sep 21, 3:53 PM CDT | Severe Thunderstorm Watch | SPC | Houston | 4 hr |
| Sep 20, 11:09 PM CDT | Mesoscale Discussion | SPC | Barron, Burnett, Chippewa, Clark, Dunn, Eau Claire and 9 more | 81 min |
| Sep 21, 10:24 AM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calumet, Clark, Columbia, Dodge and 27 more | 66 min |
| Sep 21, 2:46 PM CDT | Tornado Watch | SPC | Adams, Ashland, Bayfield, Chippewa, Clark, Eau Claire and 25 more | 8 hr |
| Sep 21, 6:17 PM CDT | Mesoscale Discussion | SPC | Columbia, Dane, Dodge, Grant, Green, Iowa and 7 more | 88 min |
| Sep 21, 6:49 PM CDT | Mesoscale Discussion | SPC | Brown, Door, Kewaunee, Manitowoc, Sheboygan | 86 min |
Nearby
Severe Thunderstorm Watches in Minnesota, 2007Severe Thunderstorm Watches in Wisconsin, 2007Every severe thunderstorm watch in 2007
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.