Alert archive / Vermont / Mesoscale Discussions in 2011

Mesoscale Discussion 1645

July 17, 2011Coos County, Grafton County, New Hampshire; 4 counties in New York; 10 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at Jul 17, 2011, 10:09 PM EDT for Coos County, Grafton County, New Hampshire; 4 counties in New York; 10 counties in Vermont. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Jul 17, 2011, 10:09 PM EDT (02:09 UTC)
Expired: Jul 17, 2011, 11:15 PM EDT
In force: 66 min
Issued by: the Storm Prediction Center

Counties Coos County, NH, Grafton County, NH, Clinton County, NY, Essex County, NY, Franklin County, NY, St. Lawrence County, NY, Addison County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Washington County, VT

The radar

The Burlington radar (KCXX), 35 km from the middle of the area, began a volume at 02:09 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

Albany, NY (KALY), launched 00:00Z, 2.2 hours before the alert went out and 186 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: 98 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 2064 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 73 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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 18, 3:58 PM EDT	Mesoscale Discussion	SPC	Allegany, Cattaraugus, Cayuga, Chautauqua, Chemung, Chenango and 36 more	92 min

Nearby

Mesoscale Discussions in Vermont, 2011 Mesoscale Discussions in New York, 2011 Mesoscale Discussions in New Hampshire, 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.