Alert archive / Ohio / Mesoscale Discussions in 2018

Mesoscale Discussion 349

May 4, 20187 counties in New York; 19 counties in Ohio; 8 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at May 4, 2018, 1:04 PM EDT for 7 counties in New York; 19 counties in Ohio; 8 counties in Pennsylvania. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: May 4, 2018, 1:04 PM EDT (17:04 UTC)
Expired: May 4, 2018, 2:30 PM EDT
In force: 86 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 34 counties

Cattaraugus County, NY, Chautauqua County, NY, Erie County, NY, Genesee County, NY, Livingston County, NY, Monroe County, NY, Wyoming County, NY, Ashland County, OH, Ashtabula County, OH, Carroll County, OH, Columbiana County, OH, Crawford County, OH, Cuyahoga County, OH, Geauga County, OH, Holmes County, OH, Huron County, OH, Lake County, OH, Lorain County, OH, Mahoning County, OH, Medina County, OH, Portage County, OH, Richland County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Wayne County, OH, Crawford County, PA, Erie County, PA, Forest County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Venango County, PA, Warren County, PA

The radar

The Cleveland radar (KCLE), 115 km from the middle of the area, began a volume at 17:06 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.

The nearest sounding before it

Pittsburgh, PA (KAGC), launched 12:00Z, 5.1 hours before the alert went out and 145 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: 21 J/kg
Mixed-layer CIN: -65 J/kg
Mixed-layer LCL: 1308 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 291 m²/s²
0-3 km storm-relative helicity: 305 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
May 4, 2:18 PM EDT	Mesoscale Discussion	SPC	Clinton, Essex, Franklin, Fulton, Hamilton, Herkimer and 5 more	87 min
May 4, 2:23 PM EDT	Mesoscale Discussion	SPC	Allegany, Cattaraugus, Cayuga, Chemung, Cortland, Erie and 17 more	97 min
May 4, 2:44 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 23 more	6 hr
May 4, 3:16 PM EDT	Tornado Watch	SPC	Clinton, Essex, Franklin, Fulton, Hamilton, Herkimer and 5 more	6 hr
May 4, 4:20 PM EDT	Mesoscale Discussion	SPC	Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 21 more	55 min
May 4, 5:52 PM EDT	Mesoscale Discussion	SPC	Albany, Columbia, Delaware, Dutchess, Greene, Montgomery and 11 more	83 min
May 4, 6:20 PM EDT	Severe Thunderstorm Watch	SPC	Albany, Columbia, Delaware, Dutchess, Greene, Montgomery and 6 more	4 hr
May 4, 6:48 PM EDT	Mesoscale Discussion	SPC	Clinton, Essex, Franklin, Fulton, Hamilton, Herkimer and 5 more	117 min
May 4, 1:22 PM EDT	Severe Thunderstorm Watch	SPC	Ashland, Ashtabula, Crawford, Cuyahoga, Erie, Geauga and 22 more	5 hr
May 4, 4:30 PM EDT	Mesoscale Discussion	SPC	Adams, Athens, Brown, Butler, Clark, Clermont and 21 more	2 hr

Nearby

Mesoscale Discussions in Ohio, 2018 Mesoscale Discussions in Pennsylvania, 2018 Mesoscale Discussions in New York, 2018 Every mesoscale discussion in 2018

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.