Alert archive / Indiana / Mesoscale Discussions in 2021
Mesoscale Discussion 1748
The Storm Prediction Center issued this mesoscale discussion at Sep 14, 2021, 6:04 PM EDT for 21 counties in Indiana; 20 counties in Michigan; 7 counties in Ohio. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- Sep 14, 2021, 6:04 PM EDT (22:04 UTC)
- Expired
- Sep 14, 2021, 7:30 PM EDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 498
All 48 counties
Adams County, IN, Allen County, IN, Blackford County, IN, Carroll County, IN, Cass County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Grant County, IN, Huntington County, IN, Kosciusko County, IN, LaGrange County, IN, Marshall County, IN, Miami County, IN, Noble County, IN, Pulaski County, IN, Steuben County, IN, Wabash County, IN, Wells County, IN, White County, IN, Whitley County, IN, Branch County, MI, Calhoun County, MI, Eaton County, MI, Genesee County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Monroe County, MI, Oakland 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, Defiance County, OH, Fulton County, OH, Henry County, OH, Lucas County, OH, Paulding County, OH, Van Wert County, OH, Williams County, OH
The radar
The Detroit radar (KDTX), 112 km from the middle of the area, began a volume at 22:05 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, 10.1 hours before the alert went out and 116 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
- 620 J/kg
- Mixed-layer CIN
- -74 J/kg
- Mixed-layer LCL
- 977 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 105 m²/s²
- 0-3 km storm-relative helicity
- 105 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.1
The text
As transmitted.
266
ACUS11 KWNS 142205
SWOMCD
SPC MCD 142204
MIZ000-OHZ000-INZ000-142330-
Mesoscale Discussion 1748
NWS Storm Prediction Center Norman OK
0504 PM CDT Tue Sep 14 2021
Areas affected...Eastern Michigan...northern Indiana...and far
northwest Ohio
Concerning...Severe Thunderstorm Watch 498...
Valid 142204Z - 142330Z
The severe weather threat for Severe Thunderstorm Watch 498
continues.
SUMMARY...An isolated large hail and damaging-wind threat will
continue into the evening.
DISCUSSION...Storm coverage has been somewhat sparse ahead of the
cold front so far with only occasional stronger cores. This is
probably a result of weak forcing from a weak confluence zone with
the upper forcing farther north in Canada and the surface front
farther west. However, the environment still remains quite favorable
ahead of these storms with MLCAPE around 1500 to 2000 J/kg per SPC
mesoanalysis. In addition, the KDTX VWP shows flow in excess of 40
knots below 1km. Therefore, damaging winds will remain a threat with
any stronger storms which can bring some of this stronger flow to
the surface. The best damaging-wind threat may materialize from the
storm cluster developing in Kalamazoo, Calhoun, St. Joseph, and
Branch counties in southern Michigan given current convective trends
and a favorable downstream environment.
..Bentley.. 09/14/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CLE...ILN...DTX...IWX...GRR...IND...LOT...
LAT...LON 40558723 41418646 42438522 42988449 43528350 43818249
43398180 42338251 40448509 40558723SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 14, 2:12 PM EDT | Mesoscale Discussion | SPC | Allen, DeKalb, Elkhart, Fulton, Huntington, Kosciusko and 9 more | 2 hr |
| Sep 14, 3:08 PM EDT | Severe Thunderstorm Watch | SPC | Allen, Blackford, Cass, DeKalb, Elkhart, Fulton and 16 more | 7 hr |
| Sep 14, 4:18 PM EDT | Mesoscale Discussion | SPC | Benton, Newton, Warren | 117 min |
| Sep 14, 7:46 PM EDT | Mesoscale Discussion | SPC | Adams, Allen, Blackford, DeKalb, Delaware, Grant and 8 more | 89 min |
Nearby
Mesoscale Discussions in Indiana, 2021Mesoscale Discussions in Michigan, 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; radar from the NEXRAD Level II archive.