Alert archive / New York / Mesoscale Discussions in 2011

Mesoscale Discussion 1730

July 25, 201120 counties in New York; 4 counties in Ohio; 14 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2011, 11:12 AM EDT for 20 counties in New York; 4 counties in Ohio; 14 counties in Pennsylvania. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Jul 25, 2011, 11:12 AM EDT (15:12 UTC)
Expired: Jul 25, 2011, 12:15 PM EDT
In force: 63 min
Issued by: the Storm Prediction Center

All 38 counties

Allegany County, NY, Cattaraugus County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Hamilton County, NY, Herkimer County, NY, Livingston County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Ontario County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Wyoming County, NY, Yates County, NY, Geauga County, OH, Mahoning County, OH, Portage County, OH, Trumbull County, OH, Butler County, PA, Cameron County, PA, Clarion County, PA, Crawford County, PA, Elk County, PA, Forest County, PA, Jefferson County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Potter County, PA, Tioga County, PA, Venango County, PA, Warren County, PA

The radar

The Buffalo radar (KBUF), 106 km from the middle of the area, began a volume at 15:15 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 683Jul 25, 11:40 AM EDT

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 3.2 hours before the alert went out and 103 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: 992 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 857 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 91 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

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
Jul 25, 11:37 AM EDT	Severe Thunderstorm Watch	SPC	Albany, Allegany, Broome, Cattaraugus, Cayuga, Chautauqua and 33 more	7 hr
Jul 25, 3:16 PM EDT	Mesoscale Discussion	SPC	Albany, Allegany, Broome, Cayuga, Chemung, Chenango and 26 more	59 min
Jul 25, 1:12 PM EDT	Mesoscale Discussion	SPC	Berks, Bucks, Chester, Delaware, Lancaster, Montgomery and 2 more	2 hr
Jul 25, 5:42 PM EDT	Mesoscale Discussion	SPC	Adams, Bedford, Berks, Blair, Bucks, Cambria and 25 more	63 min

Nearby

Mesoscale Discussions in New York, 2011 Mesoscale Discussions in Pennsylvania, 2011 Mesoscale Discussions in Ohio, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.