Alert archive / Ohio / Mesoscale Discussions in 2011

Mesoscale Discussion 1650

July 18, 201133 counties in Ohio; 14 counties in Pennsylvania; Brooke County, Hancock County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 18, 2011, 1:18 PM EDT for 33 counties in Ohio; 14 counties in Pennsylvania; Brooke County, Hancock County, West Virginia. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: Jul 18, 2011, 1:18 PM EDT (17:18 UTC)
Expired: Jul 18, 2011, 3:15 PM EDT
In force: 117 min
Issued by: the Storm Prediction Center

All 49 counties

Ashland County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Crawford County, OH, Cuyahoga County, OH, Delaware County, OH, Erie County, OH, Geauga County, OH, Hancock County, OH, Hardin County, OH, Harrison County, OH, Holmes County, OH, Huron County, OH, Jefferson County, OH, Knox County, OH, Lorain County, OH, Mahoning County, OH, Marion County, OH, Medina County, OH, Morrow County, OH, Ottawa County, OH, Portage County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Wayne County, OH, Wood County, OH, Wyandot County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Elk County, PA, Forest County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV

The radar

The Cleveland radar (KCLE), 66 km from the middle of the area, began a volume at 17:20 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.

Severe Thunderstorm Watch 658Jul 18, 3:55 PM EDT

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 5.3 hours before the alert went out and 119 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: 243 J/kg
Mixed-layer CIN: -76 J/kg
Mixed-layer LCL: 725 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 91 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 18, 3:57 PM EDT	Severe Thunderstorm Watch	SPC	Ashland, Ashtabula, Belmont, Carroll, Columbiana, Coshocton and 33 more	6 hr
Jul 18, 6:14 PM EDT	Mesoscale Discussion	SPC	Athens, Champaign, Clark, Crawford, Delaware, Fairfield and 27 more	31 min
Jul 18, 6:26 PM EDT	Severe Thunderstorm Watch	SPC	Adams, Athens, Brown, Champaign, Clark, Clinton and 23 more	4 hr

Nearby

Mesoscale Discussions in Ohio, 2011 Mesoscale Discussions in Pennsylvania, 2011 Mesoscale Discussions in West Virginia, 2011 Every mesoscale discussion in 2011

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.