Alert archive / Vermont / Severe Thunderstorm Watches in 2015

Severe Thunderstorm Watch 466

August 3, 20154 states

The Storm Prediction Center issued this severe thunderstorm watch at Aug 3, 2015, 1:16 PM EDT for 4 states. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Aug 3, 2015, 1:16 PM EDT (17:16 UTC)
Expired
Aug 3, 2015, 9:00 PM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 27 counties

Aroostook County, ME, Franklin County, ME, Oxford County, ME, Penobscot County, ME, Piscataquis County, ME, Somerset County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Sullivan County, NH, Essex County, NY, Addison County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT, Windsor County, VT

The radar

The Caribou radar (KCBW), 183 km from the middle of the area, began a volume at 17:18 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
30%
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
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 3, 1:27 PM EDTSevere Thunderstorm WarningCARAroostook, Piscataquis, Somerset48 min
Aug 3, 2:15 PM EDTSevere Thunderstorm WarningBTVAddison, Chittenden, Washington45 min
Aug 3, 2:17 PM EDTSevere Thunderstorm WarningGYXSomerset43 min
Aug 3, 2:24 PM EDTSevere Thunderstorm WarningCARAroostook, Penobscot, Piscataquis, Somerset51 min
Aug 3, 2:36 PM EDTSevere Thunderstorm WarningBTVAddison28 min
Aug 3, 2:41 PM EDTSevere Thunderstorm WarningBTVChittenden, Franklin, Lamoille, Orleans, Washington21 min
Aug 3, 2:56 PM EDTSevere Thunderstorm WarningBTVOrleans34 min
Aug 3, 2:59 PM EDTSevere Thunderstorm WarningGYXSomerset46 min
Aug 3, 3:18 PM EDTFlash Flood WarningBTVOrleans6 hr
Aug 3, 3:33 PM EDTSevere Thunderstorm WarningCARAroostook, Penobscot, Piscataquis42 min
Aug 3, 3:36 PM EDTSevere Thunderstorm WarningCARAroostook39 min
Aug 3, 3:45 PM EDTSevere Thunderstorm WarningBTVCaledonia, Orleans19 min
Aug 3, 4:05 PM EDTSevere Thunderstorm WarningCARAroostook40 min
Aug 3, 4:16 PM EDTSevere Thunderstorm WarningGYXSomerset44 min
Aug 3, 4:37 PM EDTSevere Thunderstorm WarningCARAroostook38 min
Aug 3, 4:46 PM EDTSevere Thunderstorm WarningGYXGrafton44 min
Aug 3, 5:01 PM EDTSevere Thunderstorm WarningGYXFranklin, Oxford44 min
Aug 3, 5:05 PM EDTSevere Thunderstorm WarningGYXGrafton40 min
Aug 3, 5:08 PM EDTSevere Thunderstorm WarningGYXCheshire, Grafton, Merrimack, Sullivan67 min
Aug 3, 5:23 PM EDTSevere Thunderstorm WarningGYXCoos, Grafton31 min
Aug 3, 5:24 PM EDTSevere Thunderstorm WarningCARAroostook66 min
Aug 3, 5:29 PM EDTFlash Flood WarningGYXGrafton3 hr
Aug 3, 5:33 PM EDTSevere Thunderstorm WarningGYXCoos, Grafton57 min
Aug 3, 5:42 PM EDTSevere Thunderstorm WarningGYXGrafton41 min
Aug 3, 5:44 PM EDTSevere Thunderstorm WarningGYXFranklin, Oxford, Somerset61 min
Aug 3, 5:57 PM EDTSevere Thunderstorm WarningGYXBelknap, Cheshire, Grafton, Hillsborough, Merrimack, Sullivan48 min
Aug 3, 6:02 PM EDTFlash Flood WarningGYXFranklin, Oxford3 hr
Aug 3, 6:13 PM EDTSevere Thunderstorm WarningGYXBelknap, Carroll, Coos, Grafton62 min
Aug 3, 6:22 PM EDTFlash Flood WarningGYXCarroll, Coos, Grafton3 hr
Aug 3, 6:32 PM EDTSevere Thunderstorm WarningGYXCoos38 min
Aug 3, 6:35 PM EDTSevere Thunderstorm WarningGYXBelknap, Carroll, Cheshire, Hillsborough, Merrimack, Rockingham and 2 more40 min
Aug 3, 6:41 PM EDTSevere Thunderstorm WarningCARAroostook, Penobscot, Piscataquis64 min
Aug 3, 6:47 PM EDTSevere Thunderstorm WarningGYXFranklin, Somerset43 min
Aug 3, 6:55 PM EDTSevere Thunderstorm WarningGYXCumberland, Oxford, York51 min
Aug 3, 7:40 PM EDTSevere Thunderstorm WarningGYXAndroscoggin, Franklin, Kennebec, Oxford, Somerset65 min
Aug 3, 8:12 PM EDTSevere Thunderstorm WarningCARAroostook, Penobscot, Piscataquis48 min
Aug 3, 8:12 PM EDTSevere Thunderstorm WarningGYXCoos32 min
Aug 3, 8:27 PM EDTSevere Thunderstorm WarningGYXBelknap, Carroll, Hillsborough, Merrimack, Rockingham, Strafford48 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

Caribou, ME (KCAR), launched 12:00Z, 5.3 hours before the alert went out and 206 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, Caribou, ME at 12:00Z on 2015-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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, Caribou, ME at 12:00Z on 2015-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1296 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
160 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
Aug 3, 12:45 PM EDTMesoscale DiscussionSPCAroostook, Franklin, Oxford, Piscataquis, Somerset2 hr

Nearby

Severe Thunderstorm Watches in Vermont, 2015Severe Thunderstorm Watches in New Hampshire, 2015Severe Thunderstorm Watches in Maine, 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.