Alert archive / Indiana / Mesoscale Discussions in 2021
Mesoscale Discussion 1480
The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2021, 1:26 PM EDT for 13 counties in Indiana; 4 counties in Michigan; 8 counties in Ohio. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Aug 11, 2021, 1:26 PM EDT (17:26 UTC)
- Expired
- Aug 11, 2021, 3:00 PM EDT
- In force
- 94 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 423
All 25 counties
Adams County, IN, Allen County, IN, DeKalb County, IN, Elkhart County, IN, Huntington County, IN, Kosciusko County, IN, LaGrange County, IN, Miami County, IN, Noble County, IN, Steuben County, IN, Wabash County, IN, Wells County, IN, Whitley County, IN, Branch County, MI, Hillsdale County, MI, Kalamazoo County, MI, Saint Joseph County, MI, Allen County, OH, Defiance County, OH, Fulton County, OH, Henry County, OH, Paulding County, OH, Putnam County, OH, Van Wert County, OH, Williams County, OH
The radar
The Northern Indiana radar (KIWX), 38 km from the middle of the area, began a volume at 17:28 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, 5.4 hours before the alert went out and 214 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
- 106 J/kg
- Mixed-layer CIN
- -290 J/kg
- Mixed-layer LCL
- 1220 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 169 m²/s²
- 0-3 km storm-relative helicity
- 167 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
670
ACUS11 KWNS 111727
SWOMCD
SPC MCD 111726
MIZ000-OHZ000-INZ000-111900-
Mesoscale Discussion 1480
NWS Storm Prediction Center Norman OK
1226 PM CDT Wed Aug 11 2021
Areas affected...northern Indiana...southern Michigan and northwest
Ohio
Concerning...Severe Thunderstorm Watch 423...
Valid 111726Z - 111900Z
The severe weather threat for Severe Thunderstorm Watch 423
continues.
SUMMARY...A more organized severe weather threat is developing
across northern Indiana.
DISCUSSION...The earlier cluster of storms has now congealed into
more of a bowing segment across northern Indiana. Recently,
estimated 60 mph winds were reported in Kosciusko county and radar
estimated winds in excess of 60 knots are being measured by the KIWX
radar at 700 feet to the northwest of the radar. In addition,
periodic, weak circulations have been observed along this line, to
the south of the apex of the bow. The downstream airmass downstream
of this bowing segment is very unstable with MLCAPE around 2500
J/kg. Therefore, expect maintenance and potential strengthening as
this MCS moves east across northern Indiana and eventually into
northwest Ohio.
..Bentley/Thompson.. 08/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ILN...DTX...IWX...GRR...
LAT...LON 41988597 42268555 42178431 41478397 40828397 40548472
40548571 40638617 41058616 41988597SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 8:12 PM EDT | Mesoscale Discussion | SPC | DeKalb, Elkhart, Kosciusko, LaGrange, Lake, LaPorte and 6 more | 63 min |
| Aug 10, 8:38 PM EDT | Severe Thunderstorm Watch | SPC | DeKalb, Elkhart, Fulton, Jasper, Kosciusko, LaGrange and 10 more | 5 hr |
| Aug 10, 10:57 PM EDT | Mesoscale Discussion | SPC | Allen, DeKalb, Elkhart, Fulton, Huntington, Jasper and 8 more | 93 min |
| Aug 11, 2:20 AM EDT | Mesoscale Discussion | SPC | Benton, Jasper, Lake, Newton, Warren | 115 min |
| Aug 11, 9:34 AM EDT | Mesoscale Discussion | SPC | Benton, Jasper, Lake, Newton, Porter | 86 min |
| Aug 11, 9:52 AM EDT | Severe Thunderstorm Watch | SPC | Jasper, Lake, Newton, Porter | 4 hr |
| Aug 11, 10:52 AM EDT | Mesoscale Discussion | SPC | Adams, Allen, Carroll, Cass, DeKalb, Elkhart and 20 more | 83 min |
| Aug 11, 11:50 AM EDT | Severe Thunderstorm Watch | SPC | Adams, Allen, Blackford, Cass, DeKalb, Elkhart and 18 more | 4 hr |
| Aug 11, 12:48 PM EDT | Mesoscale Discussion | SPC | Menominee | 117 min |
| Aug 11, 1:17 PM EDT | Tornado Watch | SPC | Delta, Menominee | 8 hr |
| Aug 11, 2:12 PM EDT | Mesoscale Discussion | SPC | Genesee, Huron, Lapeer, Lenawee, Livingston, Macomb and 9 more | 93 min |
| Aug 11, 2:32 PM EDT | Severe Thunderstorm Watch | SPC | Bay, Genesee, Huron, Lapeer, Lenawee, Livingston and 11 more | 4 hr |
| Aug 11, 4:20 PM EDT | Mesoscale Discussion | SPC | Alcona, Alpena, Antrim, Benzie, Cheboygan, Crawford and 13 more | 115 min |
| Aug 11, 4:48 PM EDT | Severe Thunderstorm Watch | SPC | Alcona, Alpena, Antrim, Arenac, Benzie, Charlevoix and 17 more | 3 hr |
| Aug 11, 7:45 PM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Calhoun, Cass, Clinton, Eaton and 15 more | 90 min |
| Aug 11, 9:31 AM EDT | Mesoscale Discussion | SPC | Ashland, Ashtabula, Carroll, Columbiana, Coshocton, Crawford and 19 more | 89 min |
| Aug 11, 11:50 AM EDT | Mesoscale Discussion | SPC | Carroll, Columbiana, Harrison, Jefferson, Mahoning, Trumbull | 115 min |
| Aug 11, 4:24 PM EDT | Mesoscale Discussion | SPC | Athens, Belmont, Carroll, Clinton, Columbiana, Coshocton and 31 more | 96 min |
| Aug 11, 4:57 PM EDT | Severe Thunderstorm Watch | SPC | Ashtabula, Belmont, Carroll, Columbiana, Coshocton, Geauga and 13 more | 3 hr |
Nearby
Mesoscale Discussions in Indiana, 2021Mesoscale Discussions in Ohio, 2021Mesoscale Discussions in Michigan, 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; radar from the NEXRAD Level II archive.