Alert archive / Ohio / Mesoscale Discussions in 2021

Mesoscale Discussion 1182

July 7, 20214 states

The Storm Prediction Center issued this mesoscale discussion at Jul 7, 2021, 3:59 PM EDT for 4 states. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Jul 7, 2021, 3:59 PM EDT (19:59 UTC)
Expired
Jul 7, 2021, 5:30 PM EDT
In force
91 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 343
All 59 counties

Allen County, IN, DeKalb County, IN, Elkhart County, IN, LaGrange County, IN, Noble County, IN, Steuben County, IN, Barry County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Eaton County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Kalamazoo County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Monroe County, MI, Oakland County, MI, Saint Joseph County, MI, Washtenaw County, MI, Wayne County, MI, Ashland County, OH, Ashtabula County, OH, Crawford County, OH, Cuyahoga County, OH, Defiance County, OH, Erie County, OH, Fulton County, OH, Geauga County, OH, Hancock 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, 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, Wayne County, OH, Williams County, OH, Wood County, OH, Wyandot County, OH, Crawford County, PA, Erie County, PA

The radar

The Cleveland radar (KCLE), 76 km from the middle of the area, began a volume at 20:03 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, 8.0 hours before the alert went out and 120 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.

Skew-T log-pSkew-T log-p diagram, Detroit, MI at 12:00Z on 2021-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1092 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Detroit, MI at 12:00Z on 2021-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
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

Open this sounding in Storm Lab

The text

As transmitted.

678 
ACUS11 KWNS 071959
SWOMCD
SPC MCD 071959 
PAZ000-OHZ000-MIZ000-INZ000-072130-

Mesoscale Discussion 1182
NWS Storm Prediction Center Norman OK
0259 PM CDT Wed Jul 07 2021

Areas affected...southern Lower MI...northeast IN...northern
OH...far northwest PA

Concerning...Severe Thunderstorm Watch 343...

Valid 071959Z - 072130Z

The severe weather threat for Severe Thunderstorm Watch 343
continues.

SUMMARY...The threat for damaging downburst winds continues across
the watch area.

DISCUSSION...Several clusters of strong/severe storms were ongoing
across the watch area as of 1955z, with the greatest concentration
of severe storms in the vicinity of a stationary front over southern
lower MI.  The environment remains supportive of a continued severe
threat with moderate instability outside of convectively-cooled
areas, and damaging winds will remain the primary hazard through
early evening, when overall storm intensity should begin to wane.

..Bunting.. 07/07/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...PBZ...CLE...ILN...DTX...IWX...GRR...

LAT...LON   41308582 41828610 42708528 42848402 42968286 42888245
            42508259 42298299 42068318 41738285 41688235 41918191
            42198128 42328063 42298007 42017986 41727987 41378060
            41008066 40688137 40348259 40708371 41308582

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 7, 12:07 PM EDTMesoscale DiscussionSPCAdams, Allen, DeKalb, Elkhart, Huntington, LaGrange and 4 more83 min
Jul 7, 1:31 PM EDTSevere Thunderstorm WatchSPCAllen, DeKalb, Elkhart, Kosciusko, LaGrange, Noble and 2 more7 hr
Jul 7, 3:02 PM EDTMesoscale DiscussionSPCBenton, Jasper, Lake, LaPorte, Newton, Porter and 4 more88 min
Jul 7, 3:31 PM EDTSevere Thunderstorm WatchSPCCarroll, Columbiana7 hr
Jul 7, 1:50 PM EDTMesoscale DiscussionSPCLackawanna, Monroe, Northampton, Pike, Wayne115 min
Jul 7, 2:41 PM EDTSevere Thunderstorm WatchSPCBerks, Bradford, Bucks, Carbon, Columbia, Lackawanna and 15 more10 hr
Jul 7, 4:48 PM EDTMesoscale DiscussionSPCBerks, Bradford, Bucks, Carbon, Columbia, Lackawanna and 15 more87 min
Jul 7, 7:11 PM EDTMesoscale DiscussionSPCBradford, Cameron, Carbon, Centre, Clinton, Columbia and 16 more2 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.