Alert archive / Minnesota / Severe Thunderstorm Watches in 2015
Severe Thunderstorm Watch 503
The Storm Prediction Center issued this severe thunderstorm watch at Sep 6, 2015, 3:42 PM CDT for 39 counties in Minnesota; 4 counties in Wisconsin. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 6, 2015, 3:42 PM CDT (20:42 UTC)
- Expired
- Sep 6, 2015, 9:47 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 43 counties
Aitkin County, MN, Anoka County, MN, Benton County, MN, Carlton County, MN, Carver County, MN, Cass County, MN, Chippewa County, MN, Chisago County, MN, Cook County, MN, Crow Wing County, MN, Dakota County, MN, Douglas County, MN, Hennepin County, MN, Isanti County, MN, Itasca County, MN, Kanabec County, MN, Kandiyohi County, MN, Koochiching County, MN, Lac qui Parle County, MN, Lake County, MN, McLeod County, MN, Meeker County, MN, Mille Lacs County, MN, Morrison County, MN, Pine County, MN, Pope County, MN, Ramsey County, MN, Redwood County, MN, Renville County, MN, Saint Louis County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Swift County, MN, Todd County, MN, Washington County, MN, Wright County, MN, Yellow Medicine County, MN, Bayfield County, WI, Burnett County, WI, Douglas County, WI, Washburn County, WI
The radar
The Duluth radar (KDLH), 85 km from the middle of the area, began a volume at 20:44 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
- 50%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- 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 6, 5:52 PM CDT | Severe Thunderstorm Warning | DLH | Aitkin, Cass, Crow Wing | 23 min |
| Sep 6, 6:18 PM CDT | Severe Thunderstorm Warning | DLH | Aitkin | 27 min |
| Sep 6, 6:50 PM CDT | Severe Thunderstorm Warning | DLH | Aitkin, Carlton, Saint Louis | 25 min |
| Sep 6, 7:19 PM CDT | Severe Thunderstorm Warning | DLH | Cook, Lake | 26 min |
| Sep 6, 7:24 PM CDT | Severe Thunderstorm Warning | DLH | Carlton, Pine | 16 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
International Fa, MN (KINL), launched 12:00Z, 8.7 hours before the alert went out and 190 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
- 408 J/kg
- Mixed-layer CIN
- -36 J/kg
- Mixed-layer LCL
- 640 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 106 m²/s²
- 0-3 km storm-relative helicity
- 185 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 5, 7:34 PM CDT | Mesoscale Discussion | SPC | Aitkin, Cass, Crow Wing, Douglas, Hubbard, Itasca and 6 more | 86 min |
| Sep 6, 2:31 PM CDT | Mesoscale Discussion | SPC | Aitkin, Anoka, Beltrami, Benton, Blue Earth, Brown and 51 more | 119 min |
| Sep 6, 5:12 PM CDT | Mesoscale Discussion | SPC | Fillmore, Houston, Winona | 2 hr |
| Sep 6, 5:26 PM CDT | Mesoscale Discussion | SPC | Blue Earth, Cottonwood, Faribault, Freeborn, Jackson, Martin and 3 more | 94 min |
| Sep 6, 6:02 PM CDT | Severe Thunderstorm Watch | SPC | Fillmore, Houston, Mower | 7 hr |
| Sep 6, 6:29 PM CDT | Mesoscale Discussion | SPC | Aitkin, Anoka, Benton, Carlton, Carver, Chippewa and 24 more | 2 hr |
Nearby
Severe Thunderstorm Watches in Minnesota, 2015Severe Thunderstorm Watches in Wisconsin, 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.