Alert archive / Ohio / Mesoscale Discussions in 2020

Mesoscale Discussion 1018

June 27, 202036 counties in Ohio; 4 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Jun 27, 2020, 12:35 AM EDT for 36 counties in Ohio; 4 counties in Pennsylvania. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Jun 27, 2020, 12:35 AM EDT (04:35 UTC)
Expired: Jun 27, 2020, 2:30 AM EDT
In force: 115 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 309

All 40 counties

Allen County, OH, Ashland County, OH, Ashtabula County, OH, Auglaize County, OH, Champaign County, OH, Crawford County, OH, Cuyahoga County, OH, Delaware County, OH, Erie County, OH, Geauga County, OH, Hancock County, OH, Hardin County, OH, Huron County, OH, Lake County, OH, Logan County, OH, Lorain County, OH, Mahoning County, OH, Marion County, OH, Medina County, OH, Miami County, OH, Morrow County, OH, Ottawa County, OH, Portage County, OH, Putnam County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Shelby County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Union County, OH, Van Wert County, OH, Wayne County, OH, Wood County, OH, Wyandot County, OH, Crawford County, PA, Erie County, PA, Mercer County, PA, Venango County, PA

The radar

The Cleveland radar (KCLE), 78 km from the middle of the area, began a volume at 04:34 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 00:00Z, 4.6 hours before the alert went out and 183 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 18 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 1267 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 178 m²/s²
0-3 km storm-relative helicity: 231 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 26, 10:40 PM EDT	Mesoscale Discussion	SPC	Allen, Ashland, Auglaize, Champaign, Clark, Coshocton and 47 more	95 min
Jun 26, 11:15 PM EDT	Severe Thunderstorm Watch	SPC	Ashland, Ashtabula, Auglaize, Crawford, Cuyahoga, Delaware and 29 more	5 hr
Jun 27, 2:48 AM EDT	Mesoscale Discussion	SPC	Ashland, Ashtabula, Crawford, Cuyahoga, Delaware, Geauga and 18 more	57 min
Jun 27, 8:48 AM EDT	Mesoscale Discussion	SPC	Preble	87 min
Jun 27, 12:34 PM EDT	Mesoscale Discussion	SPC	Berks, Bucks, Carbon, Columbia, Dauphin, Juniata and 12 more	2 hr
Jun 27, 3:16 PM EDT	Severe Thunderstorm Watch	SPC	Berks, Bucks, Chester, Delaware, Montgomery, Philadelphia	5 hr

Nearby

Mesoscale Discussions in Ohio, 2020 Mesoscale Discussions in Pennsylvania, 2020 Every mesoscale discussion in 2020

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.