Alert archive / Pennsylvania / Mesoscale Discussions in 2011

Mesoscale Discussion 493

April 20, 2011Broome County, Chemung County, Tioga County, New York; 36 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2011, 3:45 PM EDT for Broome County, Chemung County, Tioga County, New York; 36 counties in Pennsylvania. It was in force for 30 min.

The area

The outline as issued.

The facts

Issued: Apr 20, 2011, 3:45 PM EDT (19:45 UTC)
Expired: Apr 20, 2011, 4:15 PM EDT
In force: 30 min
Issued by: the Storm Prediction Center

All 39 counties

Broome County, NY, Chemung County, NY, Tioga County, NY, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Bradford County, PA, Cambria County, PA, Carbon County, PA, Centre County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Monroe County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA

The radar

The State College radar (KCCX), 95 km from the middle of the area, began a volume at 19:47 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 172Apr 20, 4:05 PM EDT

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
Apr 20, 12:18 AM EDT	Severe Thunderstorm Watch	SPC	Crawford, Erie	4 hr
Apr 20, 2:22 AM EDT	Severe Thunderstorm Watch	SPC	Allegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 9 more	3 hr
Apr 20, 3:20 AM EDT	Mesoscale Discussion	SPC	Allegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 10 more	85 min
Apr 20, 4:03 PM EDT	Severe Thunderstorm Watch	SPC	Adams, Bedford, Berks, Blair, Bradford, Carbon and 29 more	4 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2011 Mesoscale Discussions in New York, 2011 Every mesoscale discussion in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.