Alert archive / Michigan / Severe Thunderstorm Watches in 2020
Severe Thunderstorm Watch 83
The Storm Prediction Center issued this severe thunderstorm watch at Apr 7, 2020, 7:18 PM EDT for 15 counties in Michigan. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 7, 2020, 7:18 PM EDT (23:18 UTC)
- Expired
- Apr 7, 2020, 11:21 PM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 50 kt
Counties Bay County, MI, Genesee 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, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI
The radar
The Detroit radar (KDTX), 38 km from the middle of the area, began a volume at 23:20 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 7, 7:42 PM EDT | Severe Thunderstorm Warning | DTX | Tuscola | 48 min |
| Apr 7, 7:54 PM EDT | Severe Thunderstorm Warning | DTX | Bay, Saginaw | 16 min |
| Apr 7, 8:01 PM EDT | Severe Thunderstorm Warning | DTX | Bay, Midland | 11 min |
| Apr 7, 8:19 PM EDT | Severe Thunderstorm Warning | DTX | Lapeer, Tuscola | 41 min |
| Apr 7, 8:25 PM EDT | Severe Thunderstorm Warning | DTX | Livingston, Washtenaw | 80 min |
| Apr 7, 8:41 PM EDT | Severe Thunderstorm Warning | DTX | Macomb, Saint Clair | 64 min |
| Apr 7, 9:12 PM EDT | Severe Thunderstorm Warning | DTX | Midland | 31 min |
| Apr 7, 9:17 PM EDT | Severe Thunderstorm Warning | DTX | Washtenaw | 47 min |
| Apr 7, 9:31 PM EDT | Severe Thunderstorm Warning | DTX | Bay, Saginaw | 28 min |
| Apr 7, 9:41 PM EDT | Severe Thunderstorm Warning | DTX | Monroe | 42 min |
| Apr 7, 10:47 PM EDT | Severe Thunderstorm Warning | DTX | Lenawee | 43 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, 11.3 hours before the alert went out and 38 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
- 983 m above ground
- 0-6 km bulk shear
- 60 kt
- 0-1 km storm-relative helicity
- 148 m²/s²
- 0-3 km storm-relative helicity
- 253 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 |
|---|---|---|---|---|
| Apr 7, 12:03 AM EDT | Mesoscale Discussion | SPC | Allegan, Berrien, Branch, Cass, Hillsdale, Kalamazoo and 2 more | 2 hr |
| Apr 7, 4:06 PM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Berrien, Branch, Calhoun, Cass and 20 more | 114 min |
| Apr 7, 4:55 PM EDT | Severe Thunderstorm Watch | SPC | Allegan, Antrim, Barry, Benzie, Calhoun, Clare and 25 more | 5 hr |
| Apr 7, 6:59 PM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Berrien, Branch, Calhoun, Cass and 23 more | 91 min |
Nearby
Severe Thunderstorm Watches in Michigan, 2020Every severe thunderstorm watch in 2020
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.