Alert archive / New York / Mesoscale Discussions in 2015

Mesoscale Discussion 801

May 27, 2015Berkshire County, Massachusetts; 17 counties in New York; 14 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at May 27, 2015, 11:50 AM EDT for Berkshire County, Massachusetts; 17 counties in New York; 14 counties in Vermont. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: May 27, 2015, 11:50 AM EDT (15:50 UTC)
Expired: May 27, 2015, 1:15 PM EDT
In force: 85 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 32 counties

Berkshire County, MA, Albany County, NY, Clinton County, NY, Columbia County, NY, Delaware County, NY, Essex County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Montgomery County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Ulster County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington 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, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 62 km from the middle of the area, began a volume at 15:50 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 227May 27, 12:55 PM EDT

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 3.8 hours before the alert went out and 157 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: 101 J/kg
Mixed-layer CIN: -166 J/kg
Mixed-layer LCL: 994 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 188 m²/s²
0-3 km storm-relative helicity: 193 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
May 27, 12:54 PM EDT	Severe Thunderstorm Watch	SPC	Berkshire	6 hr
May 27, 2:59 PM EDT	Mesoscale Discussion	SPC	Berkshire, Franklin, Hampden, Hampshire	2 hr
May 27, 4:49 PM EDT	Mesoscale Discussion	SPC	Berkshire, Franklin, Hampden, Hampshire	86 min
May 27, 5:02 PM EDT	Severe Thunderstorm Watch	SPC	Franklin, Hampden, Hampshire, Suffolk, Worcester	4 hr
May 27, 7:21 PM EDT	Mesoscale Discussion	SPC	Hampden, Hampshire, Worcester	54 min
May 27, 12:21 PM EDT	Mesoscale Discussion	SPC	Delaware, Dutchess, Orange, Putnam, Rockland, Sullivan and 1 more	54 min

Nearby

Mesoscale Discussions in New York, 2015 Mesoscale Discussions in Vermont, 2015 Mesoscale Discussions in Massachusetts, 2015 Every mesoscale discussion in 2015

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.