Alert archive / Michigan / Mesoscale Discussions in 2009
Mesoscale Discussion 558
The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2009, 10:23 AM EDT for 33 counties in Michigan. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 25, 2009, 10:23 AM EDT (14:23 UTC)
- Expired
- Apr 25, 2009, 12:30 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 33 counties
Alcona County, MI, Alpena County, MI, Arenac County, MI, Barry County, MI, Bay County, MI, Clare County, MI, Clinton County, MI, Crawford County, MI, Eaton County, MI, Genesee County, MI, Gladwin County, MI, Gratiot County, MI, Ingham County, MI, Ionia County, MI, Iosco County, MI, Isabella County, MI, Kent County, MI, Lake County, MI, Lapeer County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Montcalm County, MI, Montmorency County, MI, Newaygo County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Ottawa County, MI, Roscommon County, MI, Saginaw County, MI, Shiawassee County, MI, Tuscola County, MI
The radar
The NCL Michigan radar (KAPX), 111 km from the middle of the area, began a volume at 14:24 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.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Detroit, MI (KDTX), launched 12:00Z, 2.4 hours before the alert went out and 162 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
- 1402 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 221 m²/s²
- 0-3 km storm-relative helicity
- 222 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 24, 8:42 PM EDT | Mesoscale Discussion | SPC | Dickinson, Gogebic, Iron, Ontonagon | 63 min |
| Apr 25, 10:44 AM EDT | Severe Thunderstorm Watch | SPC | Alcona, Allegan, Alpena, Arenac, Barry, Bay and 35 more | 5 hr |
| Apr 25, 11:55 AM EDT | Mesoscale Discussion | SPC | Alcona, Alpena, Arenac, Barry, Bay, Calhoun and 31 more | 95 min |
| Apr 25, 1:06 PM EDT | Mesoscale Discussion | SPC | Arenac, Barry, Bay, Calhoun, Clare, Clinton and 26 more | 84 min |
| Apr 25, 2:55 PM EDT | Mesoscale Discussion | SPC | Allegan, Arenac, Barry, Bay, Berrien, Branch and 25 more | 95 min |
| Apr 25, 3:39 PM EDT | Severe Thunderstorm Watch | SPC | Allegan, Barry, Berrien, Branch, Calhoun, Cass and 23 more | 6 hr |
| Apr 25, 7:15 PM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Berrien, Branch, Calhoun, Cass and 21 more | 60 min |
Nearby
Mesoscale Discussions in Michigan, 2009Every mesoscale discussion in 2009
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.