Alert archive / Vermont / Severe Thunderstorm Watches in 2015

Severe Thunderstorm Watch 280

June 9, 20154 states

The Storm Prediction Center issued this severe thunderstorm watch at Jun 9, 2015, 3:16 PM EDT for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jun 9, 2015, 3:16 PM EDT (19:16 UTC)
Expired
Jun 9, 2015, 7:02 PM EDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 26 counties

Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT, Northwest Hills Planning Region, CT, Berkshire County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Worcester County, MA, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Sullivan County, NH, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Orange County, VT, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 102 km from the middle of the area, began a volume at 19:18 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 9, 3:19 PM EDTSevere Thunderstorm WarningALYNorthwest Hills Planning Region41 min
Jun 9, 3:28 PM EDTSevere Thunderstorm WarningALYBerkshire62 min
Jun 9, 3:43 PM EDTSevere Thunderstorm WarningALYNorthwest Hills Planning Region35 min
Jun 9, 3:44 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampshire, Worcester61 min
Jun 9, 3:51 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region39 min
Jun 9, 4:32 PM EDTSevere Thunderstorm WarningBOXHampden, Hampshire, Worcester43 min
Jun 9, 4:56 PM EDTSevere Thunderstorm WarningGYXGrafton49 min
Jun 9, 5:07 PM EDTSevere Thunderstorm WarningGYXCheshire, Hillsborough, Merrimack, Sullivan38 min
Jun 9, 5:16 PM EDTSevere Thunderstorm WarningBOXWorcester29 min
Jun 9, 5:21 PM EDTSevere Thunderstorm WarningGYXBelknap, Grafton, Merrimack, Sullivan39 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, 7.3 hours before the alert went out and 139 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 2015-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 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 2015-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 99 square meters per square second.1939587897Sfc1 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
27 J/kg
Mixed-layer CIN
-58 J/kg
Mixed-layer LCL
642 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
99 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 9, 12:36 PM EDTMesoscale DiscussionSPC114 min
Jun 9, 4:26 PM EDTMesoscale DiscussionSPC94 min

Nearby

Severe Thunderstorm Watches in Vermont, 2015Severe Thunderstorm Watches in New Hampshire, 2015Severe Thunderstorm Watches in Massachusetts, 2015Every severe thunderstorm watch 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.