Alert archive / New Hampshire / Mesoscale Discussions in 2015

Mesoscale Discussion 817

May 27, 2015Hampden County, Hampshire County, Worcester County, Massachusetts; 6 counties in New Hampshire

The Storm Prediction Center issued this mesoscale discussion at May 27, 2015, 7:21 PM EDT for Hampden County, Hampshire County, Worcester County, Massachusetts; 6 counties in New Hampshire. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: May 27, 2015, 7:21 PM EDT (23:21 UTC)
Expired: May 27, 2015, 8:15 PM EDT
In force: 54 min
Issued by: the Storm Prediction Center

Counties Hampden County, MA, Hampshire County, MA, Worcester County, MA, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Hillsborough County, NH, Merrimack County, NH, Strafford County, NH

The radar

The Boston radar (KBOX), 102 km from the middle of the area, began a volume at 23:21 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

Albany, NY (KALY), launched 12:00Z, 11.4 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: 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	Greater Bridgeport Planning Region, Northwest Hills Planning Region	6 hr
May 27, 2:59 PM EDT	Mesoscale Discussion	SPC		2 hr
May 27, 4:49 PM EDT	Mesoscale Discussion	SPC		86 min
May 27, 5:02 PM EDT	Severe Thunderstorm Watch	SPC	Capitol Planning Region, Northeastern Connecticut Planning Region	4 hr
May 27, 11:50 AM EDT	Mesoscale Discussion	SPC	Berkshire	85 min

Nearby

Mesoscale Discussions in New Hampshire, 2015 Mesoscale Discussions in Connecticut, 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.