Alert archive / Pennsylvania / Mesoscale Discussions in 2016

Mesoscale Discussion 1711

September 17, 20168 counties in New York; 10 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Sep 17, 2016, 6:55 PM EDT for 8 counties in New York; 10 counties in Pennsylvania. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued: Sep 17, 2016, 6:55 PM EDT (22:55 UTC)
Expired: Sep 17, 2016, 8:00 PM EDT
In force: 65 min
Issued by: the Storm Prediction Center
Chance of a watch: 5%

Counties Allegany County, NY, Cattaraugus County, NY, Genesee County, NY, Livingston County, NY, Monroe County, NY, Ontario County, NY, Wayne County, NY, Wyoming County, NY, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Elk County, PA, Forest County, PA, Jefferson County, PA, McKean County, PA, Venango County, PA, Warren County, PA

The radar

The Buffalo radar (KBUF), 86 km from the middle of the area, began a volume at 22:55 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, 10.9 hours before the alert went out and 83 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: 48 J/kg
Mixed-layer CIN: -304 J/kg
Mixed-layer LCL: 980 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 226 m²/s²
0-3 km storm-relative helicity: 222 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
Sep 17, 4:23 PM EDT	Mesoscale Discussion	SPC	Cattaraugus, Chautauqua, Erie, Wyoming	2 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2016 Mesoscale Discussions in New York, 2016 Every mesoscale discussion in 2016

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.