Alert archive / Maine / Mesoscale Discussions in 2013

Mesoscale Discussion 1876

September 11, 20135 states

The Storm Prediction Center issued this mesoscale discussion at Sep 11, 2013, 9:44 PM EDT for 5 states. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: Sep 11, 2013, 9:44 PM EDT (01:44 UTC)
Expired: Sep 11, 2013, 10:45 PM EDT
In force: 61 min
Issued by: the Storm Prediction Center

All 41 counties

Franklin County, MA, Hampden County, MA, Hampshire County, MA, Worcester County, MA, Androscoggin County, ME, Aroostook County, ME, Cumberland County, ME, Franklin County, ME, Kennebec County, ME, Lincoln County, ME, Oxford County, ME, Penobscot County, ME, Piscataquis County, ME, Sagadahoc County, ME, Somerset County, ME, Waldo County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Sullivan 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), 115 km from the middle of the area, began a volume at 01:46 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

Gray, ME (KGYX), launched 00:00Z, 1.7 hours before the alert went out and 137 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: 1951 J/kg
Mixed-layer CIN: -53 J/kg
Mixed-layer LCL: 1620 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 136 m²/s²
0-3 km storm-relative helicity: 140 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 6.5

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 12, 12:24 PM EDT	Mesoscale Discussion	SPC	Androscoggin, Cumberland, Franklin, Hancock, Kennebec, Knox and 6 more	66 min
Sep 12, 1:03 PM EDT	Severe Thunderstorm Watch	SPC	Androscoggin, Cumberland, Franklin, Kennebec, Knox, Lincoln and 5 more	9 hr
Sep 12, 3:26 PM EDT	Mesoscale Discussion	SPC	Cumberland, Knox, Lincoln, Sagadahoc, York	64 min
Sep 12, 12:37 PM EDT	Severe Thunderstorm Watch	SPC	Berkshire	7 hr
Sep 12, 12:02 PM EDT	Mesoscale Discussion	SPC	Albany, Broome, Chemung, Chenango, Cortland, Delaware and 12 more	58 min
Sep 12, 2:41 PM EDT	Mesoscale Discussion	SPC	Albany, Broome, Chemung, Chenango, Cortland, Delaware and 18 more	64 min
Sep 12, 4:24 PM EDT	Mesoscale Discussion	SPC	Bronx, Kings, Nassau, New York, Queens, Richmond and 1 more	66 min

Nearby

Mesoscale Discussions in Maine, 2013 Mesoscale Discussions in New Hampshire, 2013 Mesoscale Discussions in Vermont, 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.