Alert archive / Pennsylvania / Mesoscale Discussions in 2020

Mesoscale Discussion 254

March 28, 2020Allegany County, Garrett County, Maryland; 7 counties in Pennsylvania; Mineral County, Morgan County, Preston County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 28, 2020, 5:51 PM EDT for Allegany County, Garrett County, Maryland; 7 counties in Pennsylvania; Mineral County, Morgan County, Preston County, West Virginia. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Mar 28, 2020, 5:51 PM EDT (21:51 UTC)
Expired: Mar 28, 2020, 7:15 PM EDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Allegany County, MD, Garrett County, MD, Bedford County, PA, Blair County, PA, Cambria County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Somerset County, PA, Mineral County, WV, Morgan County, WV, Preston County, WV

The radar

The State College radar (KCCX), 117 km from the middle of the area, began a volume at 21:50 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

Pittsburgh, PA (KPIT), launched 12:00Z, 9.9 hours before the alert went out and 144 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 885 m above ground
0-6 km bulk shear: 71 kt
0-1 km storm-relative helicity: 504 m²/s²
0-3 km storm-relative helicity: 719 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
Mar 28, 10:32 AM EDT	Mesoscale Discussion	SPC	Allegheny, Armstrong, Beaver, Butler, Clarion, Indiana and 4 more	88 min
Mar 28, 1:42 PM EDT	Severe Thunderstorm Watch	SPC	Allegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 9 more	6 hr
Mar 28, 4:03 PM EDT	Mesoscale Discussion	SPC	Allegheny, Beaver, Butler, Greene, Lawrence, Washington and 1 more	87 min

Nearby

Mesoscale Discussions in Pennsylvania, 2020 Mesoscale Discussions in West Virginia, 2020 Mesoscale Discussions in Maryland, 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.