Alert archive / Ohio / Mesoscale Discussions in 2019

Mesoscale Discussion 1815

August 20, 20196 counties in Michigan; 22 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Aug 20, 2019, 5:50 PM EDT for 6 counties in Michigan; 22 counties in Ohio. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 20, 2019, 5:50 PM EDT (21:50 UTC)
Expired: Aug 20, 2019, 8:15 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 28 counties

Lenawee County, MI, Livingston County, MI, Monroe County, MI, Oakland County, MI, Washtenaw County, MI, Wayne County, MI, Ashland County, OH, Coshocton County, OH, Crawford County, OH, Cuyahoga County, OH, Erie County, OH, Fulton County, OH, Hancock County, OH, Holmes County, OH, Huron County, OH, Knox County, OH, Lorain County, OH, Lucas County, OH, Medina County, OH, Morrow County, OH, Ottawa County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Stark County, OH, Summit County, OH, Wayne County, OH, Wood County, OH

The radar

The Cleveland radar (KCLE), 89 km from the middle of the area, began a volume at 21:54 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, 9.8 hours before the alert went out and 165 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: 1415 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 806 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 71 m²/s²
0-3 km storm-relative helicity: 128 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.1

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
Aug 20, 3:29 PM EDT	Mesoscale Discussion	SPC	Adams, Auglaize, Brown, Butler, Champaign, Clark and 19 more	91 min
Aug 20, 3:35 PM EDT	Severe Thunderstorm Watch	SPC	Butler, Clermont, Hamilton, Montgomery, Preble, Warren	2 hr

Nearby

Mesoscale Discussions in Ohio, 2019 Mesoscale Discussions in Michigan, 2019 Every mesoscale discussion in 2019

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.