Alert archive / Maine / Mesoscale Discussions in 2020

Mesoscale Discussion 853

June 6, 20204 states

The Storm Prediction Center issued this mesoscale discussion at Jun 6, 2020, 2:20 PM EDT for 4 states. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Jun 6, 2020, 2:20 PM EDT (18:20 UTC)
Expired: Jun 6, 2020, 3:45 PM EDT
In force: 85 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 260

All 26 counties

Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Androscoggin County, ME, Cumberland County, ME, Kennebec County, ME, Knox County, ME, Lincoln County, ME, Oxford County, ME, Sagadahoc County, ME, Waldo County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Providence County, RI

The radar

The Boston radar (KBOX), 107 km from the middle of the area, began a volume at 18:19 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 12:00Z, 6.3 hours before the alert went out and 144 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: 662 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 1024 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 43 m²/s²
0-3 km storm-relative helicity: 117 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.8

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
Jun 6, 12:23 PM EDT	Severe Thunderstorm Watch	SPC	Capitol Planning Region, Northeastern Connecticut Planning Region	8 hr
Jun 6, 10:46 AM EDT	Mesoscale Discussion	SPC	Androscoggin, Cumberland, Kennebec, Knox, Lincoln, Oxford and 3 more	119 min

Nearby

Mesoscale Discussions in Maine, 2020 Mesoscale Discussions in Massachusetts, 2020 Mesoscale Discussions in New Hampshire, 2020 Every mesoscale discussion in 2020

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.