Alert archive / Ohio / Mesoscale Discussions in 2015

Mesoscale Discussion 617

May 11, 20157 counties in Ohio; Beaver County, Lawrence County, Mercer County, Pennsylvania; Hancock County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 11, 2015, 4:24 PM EDT for 7 counties in Ohio; Beaver County, Lawrence County, Mercer County, Pennsylvania; Hancock County, West Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 11, 2015, 4:24 PM EDT (20:24 UTC)
Expired: May 11, 2015, 6:30 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Columbiana County, OH, Geauga County, OH, Mahoning County, OH, Portage County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Beaver County, PA, Lawrence County, PA, Mercer County, PA, Hancock County, WV

The radar

The Cleveland radar (KCLE), 75 km from the middle of the area, began a volume at 20:26 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 167May 11, 5:45 PM EDT

The nearest sounding before it

Pittsburgh, PA (KAGC), launched 12:00Z, 8.4 hours before the alert went out and 122 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: 30 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 1342 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 56 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
May 11, 12:48 PM EDT	Mesoscale Discussion	SPC	Allen, Auglaize, Butler, Champaign, Clark, Clermont and 36 more	2 hr
May 11, 1:14 PM EDT	Tornado Watch	SPC	Allen, Ashland, Auglaize, Butler, Champaign, Clark and 43 more	7 hr
May 11, 1:53 PM EDT	Mesoscale Discussion	SPC	Adams, Athens, Brown, Gallia, Guernsey, Hocking and 12 more	3 hr
May 11, 2:19 PM EDT	Severe Thunderstorm Watch	SPC	Adams, Athens, Brown, Clermont, Clinton, Coshocton and 22 more	8 hr
May 11, 2:58 PM EDT	Mesoscale Discussion	SPC	Allen, Auglaize, Butler, Champaign, Clark, Crawford and 24 more	62 min
May 11, 4:13 PM EDT	Mesoscale Discussion	SPC	Adams, Athens, Gallia, Guernsey, Hocking, Jackson and 10 more	92 min
May 11, 4:39 PM EDT	Mesoscale Discussion	SPC	Allen, Auglaize, Butler, Champaign, Clark, Crawford and 35 more	66 min
May 11, 5:47 PM EDT	Severe Thunderstorm Watch	SPC	Ashtabula, Belmont, Carroll, Columbiana, Cuyahoga, Geauga and 12 more	4 hr
May 11, 6:23 PM EDT	Mesoscale Discussion	SPC	Adams, Brown, Clermont, Clinton, Fayette, Greene and 5 more	97 min
May 11, 7:26 PM EDT	Mesoscale Discussion	SPC	Belmont, Columbiana, Harrison, Jefferson, Mahoning, Monroe and 1 more	64 min
May 11, 1:32 PM EDT	Mesoscale Discussion	SPC	Bradford, Potter, Susquehanna, Tioga	2 hr

Nearby

Mesoscale Discussions in Ohio, 2015 Mesoscale Discussions in Pennsylvania, 2015 Mesoscale Discussions in West Virginia, 2015 Every mesoscale discussion in 2015

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.