Alert archive / West Virginia / Mesoscale Discussions in 2020

Mesoscale Discussion 905

June 10, 202014 counties in Pennsylvania; 15 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 10, 2020, 9:03 PM EDT for 14 counties in Pennsylvania; 15 counties in West Virginia. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued: Jun 10, 2020, 9:03 PM EDT (01:03 UTC)
Expired: Jun 10, 2020, 10:00 PM EDT
In force: 57 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 279

All 29 counties

Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Crawford County, PA, Erie County, PA, Forest County, PA, Greene County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Warren County, PA, Washington County, PA, Brooke County, WV, Calhoun County, WV, Doddridge County, WV, Hancock County, WV, Jackson County, WV, Marion County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Putnam County, WV, Ritchie County, WV, Roane County, WV, Tyler County, WV, Wetzel County, WV, Wirt County, WV

The radar

The Pittsburgh radar (KPBZ), 36 km from the middle of the area, began a volume at 01:05 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 280Jun 10, 10:20 PM EDT

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 00:00Z, 1.1 hours before the alert went out and 44 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: 1006 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1383 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 113 m²/s²
0-3 km storm-relative helicity: 201 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 8.4

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 10, 10:20 PM EDT	Severe Thunderstorm Watch	SPC	Cameron, Clearfield, Elk, McKean, Potter, Warren	3 hr

Nearby

Mesoscale Discussions in West Virginia, 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.