Alert archive / Michigan / Mesoscale Discussions in 2021
Mesoscale Discussion 1709
The Storm Prediction Center issued this mesoscale discussion at Sep 7, 2021, 5:37 PM EDT for 11 counties in Indiana; 29 counties in Michigan; Fulton County, Williams County, Ohio. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- Sep 7, 2021, 5:37 PM EDT (21:37 UTC)
- Expired
- Sep 7, 2021, 7:00 PM EDT
- In force
- 83 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 490
All 42 counties
Elkhart County, IN, Fulton County, IN, Kosciusko County, IN, LaGrange County, IN, LaPorte County, IN, Marshall County, IN, Noble County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Allegan County, MI, Barry County, MI, Berrien 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, Ingham County, MI, Ionia County, MI, Jackson County, MI, Kalamazoo County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Monroe County, MI, Oakland County, MI, Saginaw County, MI, Saint Clair County, MI, Saint Joseph County, MI, Shiawassee County, MI, Tuscola County, MI, Van Buren County, MI, Washtenaw County, MI, Wayne County, MI, Fulton County, OH, Williams County, OH
The nearest sounding before it
Detroit, MI (KDTX), launched 12:00Z, 9.6 hours before the alert went out and 125 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
- 1621 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 150 m²/s²
- 0-3 km storm-relative helicity
- 201 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
341
ACUS11 KWNS 072138
SWOMCD
SPC MCD 072137
MIZ000-OHZ000-INZ000-072300-
Mesoscale Discussion 1709
NWS Storm Prediction Center Norman OK
0437 PM CDT Tue Sep 07 2021
Areas affected...Portions of Lower Michigan into far northern
Indiana
Concerning...Severe Thunderstorm Watch 490...
Valid 072137Z - 072300Z
The severe weather threat for Severe Thunderstorm Watch 490
continues.
SUMMARY...The severe threat continues across portions of Lower
Michigan and far northern Indiana. Damaging gusts will be the
primary threat, though occasional large hail is also possible.
DISCUSSION...Semi-discrete storm clusters have gradually morphed
into short linear segments across portions of Lower Michigan over
the past few hours. Severe winds have recently been reported with a
few of the stronger storms, including 60 kts measured at Kalamazoo
and 57 kts at Battle Creek Executive Airport. While modest buoyancy
remains in place (i.e. 1000 J/kg MLCAPE), ample deep-layer ascent
and vertical shear are present, with 21Z mesoanalysis showing 50+
kts of effective bulk shear. As such, damaging gusts should remain
possible through the late afternoon hours, with an occasional bout
of severe hail also possible.
..Squitieri/Guyer.. 09/07/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CLE...DTX...IWX...GRR...LOT...
LAT...LON 41758701 42458625 43168522 43488428 43688350 43748300
43558266 42948264 42378286 41938316 41658356 41548443
41348526 41188573 41058614 40998650 40958688 41758701SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 7, 2:12 PM EDT | Severe Thunderstorm Watch | SPC | Benton, Jasper, Lake, Newton, Porter | 8 hr |
| Sep 7, 2:48 PM EDT | Mesoscale Discussion | SPC | DeKalb, Elkhart, Fulton, Kosciusko, LaGrange, LaPorte and 6 more | 117 min |
| Sep 7, 3:20 PM EDT | Severe Thunderstorm Watch | SPC | Cass, Elkhart, Fulton, Kosciusko, LaGrange, LaPorte and 7 more | 7 hr |
| Sep 7, 6:25 PM EDT | Mesoscale Discussion | SPC | Benton, Carroll, Cass, Miami, Tippecanoe, Warren and 1 more | 95 min |
| Sep 7, 3:40 AM EDT | Mesoscale Discussion | SPC | Baraga, Gogebic, Houghton, Iron, Ontonagon | 3 hr |
| Sep 7, 8:05 AM EDT | Mesoscale Discussion | SPC | Antrim, Benzie, Cheboygan, Emmet, Grand Traverse, Kalkaska and 1 more | 115 min |
| Sep 7, 10:15 AM EDT | Mesoscale Discussion | SPC | Antrim, Benzie, Crawford, Grand Traverse, Kalkaska, Lake and 10 more | 90 min |
| Sep 7, 11:47 AM EDT | Mesoscale Discussion | SPC | Clare, Gladwin, Isabella, Lake, Manistee, Mason and 10 more | 58 min |
| Sep 7, 12:21 PM EDT | Severe Thunderstorm Watch | SPC | Alcona, Arenac, Bay, Clare, Crawford, Gladwin and 20 more | 6 hr |
| Sep 7, 1:49 PM EDT | Mesoscale Discussion | SPC | Gratiot, Isabella, Mecosta, Montcalm, Muskegon, Newaygo and 2 more | 86 min |
Nearby
Mesoscale Discussions in Michigan, 2021Mesoscale Discussions in Indiana, 2021Mesoscale Discussions in Ohio, 2021Every mesoscale discussion in 2021
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.