Alert archive / Michigan / Mesoscale Discussions in 2003
Mesoscale Discussion 518
The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2003, 3:34 PM EDT for 32 counties in Michigan. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2003, 3:34 PM EDT (19:34 UTC)
- Expired
- Apr 20, 2003, 6:00 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 32 counties
Barry County, MI, Bay County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Gratiot County, MI, Hillsdale County, MI, Huron County, MI, Ingham County, MI, Ionia County, MI, Jackson County, MI, Kalamazoo County, MI, Kent County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Midland County, MI, Monroe County, MI, Montcalm County, MI, Oakland County, MI, Saginaw County, MI, Saint Clair County, MI, Saint Joseph County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI
The radar
The Grand Rapids radar (KGRR), 77 km from the middle of the area, began a volume at 19:37 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 nearest sounding before it
Detroit, MI (KDTX), launched 12:00Z, 7.6 hours before the alert went out and 101 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
- 41 J/kg
- Mixed-layer CIN
- -164 J/kg
- Mixed-layer LCL
- 1190 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 177 m²/s²
- 0-3 km storm-relative helicity
- 171 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 20, 3:09 PM EDT | Mesoscale Discussion | SPC | Barry, Bay, Branch, Calhoun, Cass, Clinton and 26 more | 3 hr |
| Apr 20, 3:25 PM EDT | Severe Thunderstorm Watch | SPC | Branch, Calhoun, Clinton, Eaton, Genesee, Hillsdale and 16 more | 5 hr |
Nearby
Mesoscale Discussions in Michigan, 2003Every mesoscale discussion in 2003
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.