Alert archive / New Hampshire / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 443

June 8, 2011Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut; 5 counties in Massachusetts; 7 counties in New Hampshire

The Storm Prediction Center issued this severe thunderstorm watch at Jun 8, 2011, 6:45 PM EDT for Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut; 5 counties in Massachusetts; 7 counties in New Hampshire. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jun 8, 2011, 6:45 PM EDT (22:45 UTC)
Expired
Jun 8, 2011, 11:00 PM EDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
65 kt

Counties Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Worcester County, MA, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Sullivan County, NH

The radar

The Burlington radar (KCXX), 163 km from the middle of the area, began a volume at 22:46 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 8, 7:49 PM EDTSevere Thunderstorm WarningGYXGrafton, Merrimack, Sullivan56 min
Jun 8, 8:12 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region48 min
Jun 8, 8:56 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester49 min
Jun 8, 9:42 PM EDTSevere Thunderstorm WarningBOXNortheastern Connecticut Planning Region48 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 10.8 hours before the alert went out and 155 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-pSkew-T log-p diagram, Albany, NY at 12:00Z on 2011-06-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 344 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 12:00Z on 2011-06-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
344 J/kg
Mixed-layer CIN
-215 J/kg
Mixed-layer LCL
880 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 8, 4:15 PM EDTSevere Thunderstorm WatchSPCNorthwest Hills Planning Region6 hr
Jun 8, 7:45 PM EDTMesoscale DiscussionSPC90 min
Jun 8, 3:46 PM EDTMesoscale DiscussionSPCBerkshire, Franklin, Hampshire59 min
Jun 8, 7:27 PM EDTSevere Thunderstorm WatchSPCCoos4 hr

Nearby

Severe Thunderstorm Watches in New Hampshire, 2011Severe Thunderstorm Watches in Massachusetts, 2011Severe Thunderstorm Watches in Connecticut, 2011Every severe thunderstorm watch in 2011

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.