Alert archive / Maine / Tornado Watches in 2011

Tornado Watch 416

June 1, 20115 states

The Storm Prediction Center issued this tornado watch at Jun 1, 2011, 7:40 PM EDT for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 1, 2011, 7:40 PM EDT (23:40 UTC)
Expired
Jun 1, 2011, 10:05 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 37 counties

Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT, Bristol County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Androscoggin County, ME, Cumberland County, ME, Franklin County, ME, Kennebec County, ME, Oxford County, ME, Penobscot County, ME, Piscataquis County, ME, Sagadahoc County, ME, Somerset County, ME, Waldo County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Sullivan County, NH, Bristol County, RI, Kent County, RI, Providence County, RI, Washington County, RI

The radar

The Boston radar (KBOX), 121 km from the middle of the area, began a volume at 23:41 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
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 1, 7:44 PM EDTSevere Thunderstorm WarningCARPenobscot, Piscataquis46 min
Jun 1, 7:57 PM EDTSevere Thunderstorm WarningBOXBristol, Middlesex, Norfolk, Plymouth, Suffolk, Worcester24 min
Jun 1, 8:03 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Worcester27 min
Jun 1, 8:10 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region, Northeastern Connecticut Planning Region44 min
Jun 1, 8:10 PM EDTSevere Thunderstorm WarningCARHancock, Penobscot50 min
Jun 1, 8:22 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Worcester38 min
Jun 1, 8:41 PM EDTSevere Thunderstorm WarningCARPenobscot29 min
Jun 1, 8:48 PM EDTSevere Thunderstorm WarningBOXBarnstable, Essex, Middlesex, Norfolk, Plymouth, Suffolk and 1 more42 min
Jun 1, 8:58 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Worcester32 min
Jun 1, 9:16 PM EDTSevere Thunderstorm WarningCARHancock, Penobscot29 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

Gray, ME (KGYX), launched 12:00Z, 11.7 hours before the alert went out and 128 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, Gray, ME at 12:00Z on 2011-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Gray, ME at 12:00Z on 2011-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 square meters per square second.193958Sfc1 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
1092 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
185 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.

999 
WWUS20 KWNS 012340
SEL6  
SPC WW 012340
CTZ000-MAZ000-MEZ000-NHZ000-RIZ000-CWZ000-020300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 416
NWS STORM PREDICTION CENTER NORMAN OK
740 PM EDT WED JUN 1 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       NORTHERN CONNECTICUT
       MASSACHUSETTS
       MAINE
       NEW HAMPSHIRE
       RHODE ISLAND
       COASTAL WATERS

EFFECTIVE THIS WEDNESDAY EVENING FROM 740 PM UNTIL 1100 PM EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 35 MILES SOUTH SOUTHEAST OF
WINDSOR LOCKS CONNECTICUT TO 45 MILES NORTH NORTHWEST OF BANGOR
MAINE.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 411...WW 412...WW
413...WW 414...WW 415...

DISCUSSION...ONGOING SEVERE STORMS --INCLUDING SUPERCELLS-- WILL
CONTINUE TO POSE A THREAT FOR TORNADOES...LARGE HAIL AND DAMAGING
WINDS WHILE INTERACTING WITH A MOIST AND MODERATELY UNSTABLE AIR
MASS IN PLACE ACROSS THE REGION.  THIS THREAT SHOULD BEGIN TO
DIMINISH LATER TONIGHT AS THE BOUNDARY LAYER GRADUALLY COOLS AND
STABILIZES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 27030.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 1, 10:02 AM EDTSevere Thunderstorm WatchSPCNorthwest Hills Planning Region7 hr
Jun 1, 12:26 PM EDTMesoscale DiscussionSPC64 min
Jun 1, 12:58 PM EDTTornado WatchSPCGreater Bridgeport Planning Region, Capitol Planning Region, Naugatuck Valley Planning Region, Northeastern Connecticut Planning Region7 hr
Jun 1, 4:17 PM EDTMesoscale DiscussionSPC88 min
Jun 1, 7:09 PM EDTMesoscale DiscussionSPC96 min
Jun 1, 2:19 PM EDTMesoscale DiscussionSPCAroostook, Franklin, Kennebec, Penobscot, Piscataquis, Somerset and 1 more86 min
Jun 1, 2:37 PM EDTTornado WatchSPCAroostook, Franklin, Kennebec, Knox, Lincoln, Penobscot and 3 more5 hr
Jun 1, 5:47 PM EDTMesoscale DiscussionSPCBristol, Dukes, Plymouth58 min

Nearby

Tornado Watches in Maine, 2011Tornado Watches in Massachusetts, 2011Tornado Watches in New Hampshire, 2011Every tornado 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.