Alert archive / Michigan / Severe Thunderstorm Watches in 2007
Severe Thunderstorm Watch 532
The Storm Prediction Center issued this severe thunderstorm watch at Jul 18, 2007, 4:39 PM EDT for 30 counties in Michigan. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 18, 2007, 4:39 PM EDT (20:39 UTC)
- Expired
- Jul 18, 2007, 9:42 PM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 30 counties
Arenac County, MI, Bay County, MI, Clare County, MI, Clinton County, MI, Genesee County, MI, Gladwin County, MI, Gratiot County, MI, Huron County, MI, Ingham County, MI, Ionia County, MI, Iosco County, MI, Isabella County, MI, Lake County, MI, Lapeer County, MI, Livingston County, MI, Macomb County, MI, Mecosta County, MI, Midland County, MI, Montcalm County, MI, Newaygo County, MI, Oakland County, MI, Ogemaw County, MI, Osceola County, MI, Roscommon County, MI, Saginaw County, MI, Saint Clair County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Wayne County, MI
The radar
The Detroit radar (KDTX), 102 km from the middle of the area, began a volume at 20:40 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
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 4:41 PM EDT | Severe Thunderstorm Warning | GRR | Gratiot | 79 min |
| Jul 18, 4:57 PM EDT | Severe Thunderstorm Warning | DTX | Midland | 93 min |
| Jul 18, 5:35 PM EDT | Tornado Warning | DTX | Midland | 47 min |
| Jul 18, 5:40 PM EDT | Severe Thunderstorm Warning | DTX | Saginaw | 95 min |
| Jul 18, 5:55 PM EDT | Severe Thunderstorm Warning | GRR | Gratiot | 27 min |
| Jul 18, 6:17 PM EDT | Severe Thunderstorm Warning | DTX | Shiawassee | 46 min |
| Jul 18, 6:39 PM EDT | Severe Thunderstorm Warning | DTX | Genesee | 68 min |
| Jul 18, 7:24 PM EDT | Severe Thunderstorm Warning | DTX | Lapeer, Oakland | 68 min |
| Jul 18, 7:37 PM EDT | Severe Thunderstorm Warning | GRR | Gratiot | 38 min |
| Jul 18, 7:48 PM EDT | Severe Thunderstorm Warning | DTX | Midland, Saginaw | 72 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, 8.7 hours before the alert went out and 102 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
- 317 J/kg
- Mixed-layer CIN
- -17 J/kg
- Mixed-layer LCL
- 717 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 66 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 1:17 PM EDT | Mesoscale Discussion | SPC | Menominee | 118 min |
| Jul 18, 4:03 PM EDT | Mesoscale Discussion | SPC | Arenac, Bay, Clare, Clinton, Genesee, Gladwin and 25 more | 117 min |
| Jul 18, 6:46 PM EDT | Mesoscale Discussion | SPC | Alcona, Alpena, Arenac, Barry, Bay, Clare and 42 more | 119 min |
| Jul 18, 7:38 PM EDT | Mesoscale Discussion | SPC | Allegan, Berrien, Branch, Calhoun, Cass, Hillsdale and 6 more | 97 min |
Nearby
Severe Thunderstorm Watches in Michigan, 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.