Alert archive / Pennsylvania / Mesoscale Discussions in 2020

Mesoscale Discussion 104

February 7, 2020Allegany County, New York; 18 counties in Pennsylvania; 8 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Feb 7, 2020, 5:32 AM EST for Allegany County, New York; 18 counties in Pennsylvania; 8 counties in West Virginia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Feb 7, 2020, 5:32 AM EST (10:32 UTC)
Expired: Feb 7, 2020, 9:00 AM EST
In force: 3 hr
Issued by: the Storm Prediction Center

All 27 counties

Allegany County, NY, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Cameron County, PA, Clarion County, PA, Clearfield County, PA, Elk County, PA, Fayette County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, McKean County, PA, Potter County, PA, Venango County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Harrison County, WV, Marion County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Taylor County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 57 km from the middle of the area, began a volume at 10:34 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

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 10.5 hours before the alert went out and 265 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: 545 m above ground
0-6 km bulk shear: 110 kt
0-1 km storm-relative helicity: 285 m²/s²
0-3 km storm-relative helicity: 450 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
Feb 6, 7:48 PM EST	Mesoscale Discussion	SPC	Cattaraugus, Chautauqua, Erie, Genesee, Livingston, Monroe and 3 more	4 hr
Feb 7, 9:58 AM EST	Mesoscale Discussion	SPC	Clinton, Essex, Fulton, Hamilton, Herkimer, Montgomery and 5 more	4 hr
Feb 7, 3:03 PM EST	Mesoscale Discussion	SPC	Essex	4 hr
Feb 7, 9:50 AM EST	Mesoscale Discussion	SPC	Bucks, Chester, Delaware, Montgomery, Philadelphia	85 min

Nearby

Mesoscale Discussions in Pennsylvania, 2020 Mesoscale Discussions in West Virginia, 2020 Mesoscale Discussions in New York, 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.