Alert archive / New York / Mesoscale Discussions in 2013

Mesoscale Discussion 1872

September 11, 20135 states

The Storm Prediction Center issued this mesoscale discussion at Sep 11, 2013, 1:30 PM EDT for 5 states. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: Sep 11, 2013, 1:30 PM EDT (17:30 UTC)
Expired: Sep 11, 2013, 2:30 PM EDT
In force: 60 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 45 counties

Berkshire County, MA, Androscoggin County, ME, Cumberland County, ME, Franklin County, ME, Kennebec County, ME, Oxford County, ME, Penobscot County, ME, Piscataquis County, ME, Somerset County, ME, Waldo County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Merrimack County, NH, Sullivan County, NH, Albany County, NY, Clinton County, NY, Columbia County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Montgomery County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady 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), 76 km from the middle of the area, began a volume at 17:31 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 521Sep 11, 2:35 PM EDT

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 5.5 hours before the alert went out and 176 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: 1310 J/kg
Mixed-layer CIN: -231 J/kg
Mixed-layer LCL: 970 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 49 m²/s²
0-3 km storm-relative helicity: 139 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
Sep 11, 2:33 PM EDT	Severe Thunderstorm Watch	SPC	Androscoggin, Aroostook, Cumberland, Franklin, Kennebec, Knox and 8 more	9 hr
Sep 11, 6:54 PM EDT	Mesoscale Discussion	SPC	Androscoggin, Aroostook, Franklin, Kennebec, Oxford, Penobscot and 3 more	96 min
Sep 11, 11:42 AM EDT	Mesoscale Discussion	SPC	Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 20 more	63 min
Sep 11, 12:33 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 22 more	8 hr
Sep 11, 2:47 PM EDT	Mesoscale Discussion	SPC	Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 16 more	58 min

Nearby

Mesoscale Discussions in New York, 2013 Mesoscale Discussions in Vermont, 2013 Mesoscale Discussions in Maine, 2013 Every mesoscale discussion in 2013

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.