Alert archive / Michigan / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 626
The Storm Prediction Center issued this severe thunderstorm watch at Jul 11, 2011, 9:07 AM EDT for 17 counties in Michigan. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 11, 2011, 9:07 AM EDT (13:07 UTC)
- Expired
- Jul 11, 2011, 1:12 PM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 70 kt
Counties Bay County, MI, Genesee County, MI, Huron County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Midland County, MI, Monroe County, MI, Oakland County, MI, Saginaw County, MI, Saint Clair County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI
The radar
The Detroit radar (KDTX), 21 km from the middle of the area, began a volume at 13:07 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
- 5%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 10%
- 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 |
|---|---|---|---|---|
| Jul 11, 9:42 AM EDT | Severe Thunderstorm Warning | DTX | Lenawee | 63 min |
| Jul 11, 11:39 AM EDT | Severe Thunderstorm Warning | DTX | Livingston, Shiawassee, Washtenaw | 66 min |
| Jul 11, 11:42 AM EDT | Severe Thunderstorm Warning | DTX | Lenawee | 63 min |
| Jul 11, 11:57 AM EDT | Severe Thunderstorm Warning | DTX | Genesee, Lapeer, Oakland | 63 min |
| Jul 11, 12:19 PM EDT | Severe Thunderstorm Warning | DTX | Monroe, Wayne | 56 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
Detroit, MI (KDTX), launched 12:00Z, 1.1 hours before the alert went out and 24 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
- 4 J/kg
- Mixed-layer CIN
- -284 J/kg
- Mixed-layer LCL
- 1566 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 64 m²/s²
- 0-3 km storm-relative helicity
- 149 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 |
|---|---|---|---|---|
| Jul 11, 6:07 AM EDT | Mesoscale Discussion | SPC | Lake, Manistee, Mason, Muskegon, Newaygo, Oceana and 1 more | 113 min |
| Jul 11, 6:37 AM EDT | Severe Thunderstorm Watch | SPC | Allegan, Barry, Berrien, Branch, Calhoun, Cass and 22 more | 6 hr |
| Jul 11, 8:10 AM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Bay, Berrien, Branch, Calhoun and 35 more | 95 min |
| Jul 11, 8:50 AM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Berrien, Branch, Calhoun, Cass and 13 more | 55 min |
| Jul 11, 10:55 AM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Branch, Calhoun, Cass, Clinton and 14 more | 65 min |
| Jul 11, 12:34 PM EDT | Mesoscale Discussion | SPC | Lenawee, Macomb, Monroe, Oakland, Washtenaw, Wayne | 56 min |
Nearby
Severe Thunderstorm Watches in Michigan, 2011Every severe thunderstorm watch in 2011
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.