Alert archive / Ohio / Mesoscale Discussions in 2021
Mesoscale Discussion 1178
The Storm Prediction Center issued this mesoscale discussion at Jul 7, 2021, 12:07 PM EDT for 10 counties in Indiana; 11 counties in Michigan; 43 counties in Ohio. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- Jul 7, 2021, 12:07 PM EDT (16:07 UTC)
- Expired
- Jul 7, 2021, 1:30 PM EDT
- In force
- 83 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch likely
- Chance of a watch
- 80%
All 64 counties
Adams County, IN, Allen County, IN, DeKalb County, IN, Elkhart County, IN, Huntington County, IN, LaGrange County, IN, Noble County, IN, Steuben County, IN, Wells County, IN, Whitley County, IN, Branch County, MI, Calhoun County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Lenawee County, MI, Livingston County, MI, Monroe County, MI, Saint Joseph County, MI, Washtenaw County, MI, Wayne County, MI, Allen County, OH, Ashland County, OH, Ashtabula County, OH, Auglaize County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Crawford County, OH, Cuyahoga County, OH, Defiance County, OH, Erie County, OH, Fulton County, OH, Geauga County, OH, Hancock County, OH, Hardin County, OH, Henry County, OH, Holmes County, OH, Huron County, OH, Knox County, OH, Lake County, OH, Lorain County, OH, Lucas County, OH, Mahoning County, OH, Marion County, OH, Medina County, OH, Mercer County, OH, Morrow County, OH, Ottawa County, OH, Paulding County, OH, Portage County, OH, Putnam County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Van Wert County, OH, Wayne County, OH, Williams County, OH, Wood County, OH, Wyandot County, OH
The radar
The Cleveland radar (KCLE), 108 km from the middle of the area, began a volume at 16:09 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, 4.1 hours before the alert went out and 131 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
- 1092 J/kg
- Mixed-layer CIN
- -19 J/kg
- Mixed-layer LCL
- 779 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 123 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.2
The text
As transmitted.
578
ACUS11 KWNS 071608
SWOMCD
SPC MCD 071607
OHZ000-MIZ000-INZ000-071730-
Mesoscale Discussion 1178
NWS Storm Prediction Center Norman OK
1107 AM CDT Wed Jul 07 2021
Areas affected...Southern Lower MI...northern OH...northeast IN
Concerning...Severe potential...Watch likely
Valid 071607Z - 071730Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorms are expected to increase in coverage this
afternoon, with clusters of strong/severe storms posing a risk for
primarily damaging winds. A few instances of hail will also be
possible. A Severe Thunderstorm watch will likely be needed by 18z.
DISCUSSION...Strong daytime heating continues south of an east-west
stationary front, a segment of which extends from southern Ontario
Province to southern lower MI and southeast IA. With minimal MLCIN
and moderate/pockets of strong instability developing by early-mid
afternoon, thunderstorms are expected to develop over the next few
hours and move generally east. Effective shear values across the
area will average 20 and 30 kts, supporting primarily a
multicellular/cluster storm mode. Steep low-level lapse rates and a
very moist environment will result in a risk for damaging downburst
winds with storms and clusters this afternoon. Although weak
mid-level lapse rates and modest effective shear will limit large
hail potential, isolated stronger updrafts may produce instances of
severe hail.
Observational trends will be monitored and a Severe Thunderstorm
Watch will likely be needed by 18z.
..Bunting/Guyer.. 07/07/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PBZ...CLE...ILN...DTX...IWX...GRR...
LAT...LON 42388535 42768387 42538281 42228317 41878315 41648260
42018176 42188137 42108066 41238058 40558073 40238149
40308281 40448411 40578514 41018575 41658589 42388535SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 7, 1:31 PM EDT | Severe Thunderstorm Watch | SPC | Allen, DeKalb, Elkhart, Kosciusko, LaGrange, Noble and 2 more | 7 hr |
| Jul 7, 3:02 PM EDT | Mesoscale Discussion | SPC | Benton, Jasper, Lake, LaPorte, Newton, Porter and 4 more | 88 min |
| Jul 7, 3:59 PM EDT | Mesoscale Discussion | SPC | Allen, DeKalb, Elkhart, LaGrange, Noble, Steuben | 91 min |
| Jul 7, 3:31 PM EDT | Severe Thunderstorm Watch | SPC | Carroll, Columbiana | 7 hr |
Nearby
Mesoscale Discussions in Ohio, 2021Mesoscale Discussions in Michigan, 2021Mesoscale Discussions in Indiana, 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.