Alert archive / Pennsylvania / Mesoscale Discussions in 2012

Mesoscale Discussion 1724

August 9, 2012Broome County, Chemung County, Tioga County, New York; 8 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Aug 9, 2012, 12:46 PM EDT for Broome County, Chemung County, Tioga County, New York; 8 counties in Pennsylvania. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Aug 9, 2012, 12:46 PM EDT (16:46 UTC)
Expired: Aug 9, 2012, 2:15 PM EDT
In force: 89 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Broome County, NY, Chemung County, NY, Tioga County, NY, Bradford County, PA, Cameron County, PA, Lycoming County, PA, Potter County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Wyoming County, PA

The radar

The State College radar (KCCX), 95 km from the middle of the area, began a volume at 16:46 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 12:00Z, 4.8 hours before the alert went out and 175 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: 1185 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 30 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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
Aug 9, 4:18 PM EDT	Mesoscale Discussion	SPC	Allegheny, Beaver, Greene, Washington	57 min
Aug 9, 4:41 PM EDT	Severe Thunderstorm Watch	SPC	Allegheny, Armstrong, Beaver, Butler, Clarion, Forest and 6 more	5 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2012 Mesoscale Discussions in New York, 2012 Every mesoscale discussion in 2012

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.