Alert archive / New York / Mesoscale Discussions in 2017

Mesoscale Discussion 1445

August 4, 20174 counties in New York; Addison County, Chittenden County, Grand Isle County, Vermont

The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2017, 5:53 PM EDT for 4 counties in New York; Addison County, Chittenden County, Grand Isle County, Vermont. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Aug 4, 2017, 5:53 PM EDT (21:53 UTC)
Expired: Aug 4, 2017, 8:30 PM EDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Clinton County, NY, Essex County, NY, Franklin County, NY, Warren County, NY, Addison County, VT, Chittenden County, VT, Grand Isle County, VT

The radar

The Burlington radar (KCXX), 75 km from the middle of the area, began a volume at 21:56 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 12:00Z, 9.9 hours before the alert went out and 174 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: 160 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 892 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 116 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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
Aug 4, 11:38 AM EDT	Mesoscale Discussion	SPC	Cattaraugus, Chautauqua, Erie	2 hr
Aug 4, 1:25 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 23 more	8 hr
Aug 4, 3:46 PM EDT	Mesoscale Discussion	SPC	Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 27 more	119 min
Aug 4, 7:41 PM EDT	Mesoscale Discussion	SPC	Allegany, Broome, Cattaraugus, Cayuga, Chemung, Chenango and 18 more	2 hr

Nearby

Mesoscale Discussions in New York, 2017 Mesoscale Discussions in Vermont, 2017 Every mesoscale discussion in 2017

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.