Alert archive / New Hampshire / Mesoscale Discussions in 2018

Mesoscale Discussion 786

June 18, 2018Cumberland County, York County, Maine; Essex County, Massachusetts; 8 counties in New Hampshire

The Storm Prediction Center issued this mesoscale discussion at Jun 18, 2018, 7:05 PM EDT for Cumberland County, York County, Maine; Essex County, Massachusetts; 8 counties in New Hampshire. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Jun 18, 2018, 7:05 PM EDT (23:05 UTC)
Expired: Jun 18, 2018, 8:00 PM EDT
In force: 55 min
Issued by: the Storm Prediction Center

Counties Essex County, MA, Cumberland County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Sullivan County, NH

The radar

The Portland,ME radar (KGYX), 92 km from the middle of the area, began a volume at 23:07 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, 11.1 hours before the alert went out and 92 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1400 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 137 m²/s²
0-3 km storm-relative helicity: 180 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 18, 2:49 PM EDT	Severe Thunderstorm Watch	SPC	Androscoggin, Cumberland, York	5 hr
Jun 18, 5:55 PM EDT	Mesoscale Discussion	SPC	Hampden, Hampshire, Middlesex, Norfolk, Suffolk, Worcester	2 hr
Jun 18, 12:19 PM EDT	Mesoscale Discussion	SPC	Belknap, Carroll, Grafton, Sullivan	116 min

Nearby

Mesoscale Discussions in New Hampshire, 2018 Mesoscale Discussions in Maine, 2018 Mesoscale Discussions in Massachusetts, 2018 Every mesoscale discussion in 2018

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.