Alert archive / Connecticut / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 121, NWS Boston/Norton, MA

August 21, 2011Capitol Planning Region, Connecticut

NWS Boston/Norton, MA issued this severe thunderstorm warning at Aug 21, 2011, 3:40 PM EDT for Capitol Planning Region, Connecticut. It was in force for 35 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 21, 2011, 3:40 PM EDT (19:40 UTC)
Expired
Aug 21, 2011, 4:15 PM EDT
In force
35 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon

County Capitol Planning Region, CT

The radar

The Brookhaven radar (KOKX), 108 km from the middle of the area, began a volume at 19:44 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 was reported inside it

TimeReportWhereRemark
Aug 21, 3:52 PM EDTTSTM WND DMGHartford, CTLARGE TREE DOWN ON HOUSE ON PLINY STREET

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 21, 1:20 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 7.7 hours before the alert went out and 108 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, Brookhaven, NY at 12:00Z on 2011-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 874 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2011-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
874 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
857 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
116 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.

259 
WUUS51 KBOX 211940
SVRBOX
CTC003-212015-
/O.NEW.KBOX.SV.W.0121.110821T1940Z-110821T2015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
340 PM EDT SUN AUG 21 2011

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL HARTFORD COUNTY IN NORTHERN CONNECTICUT...
  THIS INCLUDES THE CITIES OF...WEST HARTFORD...NEWINGTON...NEW
  BRITAIN...MANCHESTER...HARTFORD...EAST HARTFORD...

* UNTIL 415 PM EDT

* AT 334 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR FARMINGTON...OR NEAR
  BRISTOL...AND WAS MOVING EAST AT 30 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE...AVON...BLOOMFIELD...
  WETHERSFIELD...ROCKY HILL...GLASTONBURY...WINDSOR...SOUTH WINDSOR
  AND EAST WINDSOR.

IN ADDITION FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. GET 
INDOORS OR INSIDE A VEHICLE NOW! DO NOT SEEK SHELTER UNDER TREES. IF 
YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY 
LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT SUNDAY
EVENING FOR NORTHERN CONNECTICUT AND MASSACHUSETTS AND SOUTHERN NEW
HAMPSHIRE.

&&

LAT...LON 4183 7294 4197 7250 4195 7249 4194 7251
      4186 7252 4186 7250 4181 7251 4181 7248
      4180 7247 4168 7245 4166 7243 4166 7292
      4181 7297
TIME...MOT...LOC 1939Z 253DEG 26KT 4174 7284

$$

SIPPRELL
2 follow-up statements
605 
WWUS51 KBOX 211953
SVSBOX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
353 PM EDT SUN AUG 21 2011

CTC003-212015-
/O.CON.KBOX.SV.W.0121.000000T0000Z-110821T2015Z/
HARTFORD CT-
353 PM EDT SUN AUG 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR CENTRAL HARTFORD COUNTY...

AT 351 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR WEST HARTFORD...MOVING
EAST AT 30 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
WETHERSFIELD...HARTFORD...ROCKY HILL...GLASTONBURY...EAST HARTFORD...
WINDSOR...SOUTH WINDSOR...EAST WINDSOR AND MANCHESTER

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE 
IMMEDIATELY FOR DAMAGING WINDS...AND DEADLY CLOUD TO GROUND 
LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY 
INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT SUNDAY
EVENING FOR NORTHERN CONNECTICUT AND MASSACHUSETTS AND SOUTHERN NEW
HAMPSHIRE.

&&

LAT...LON 4197 7250 4195 7249 4194 7251 4186 7252
      4181 7251 4181 7248 4180 7247 4168 7245
      4167 7244 4166 7244 4166 7260 4166 7276
      4185 7287
TIME...MOT...LOC 1953Z 253DEG 26KT 4177 7271

$$

SIPPRELL
405 
WWUS51 KBOX 212009
SVSBOX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
409 PM EDT SUN AUG 21 2011

CTC003-212018-
/O.EXP.KBOX.SV.W.0121.000000T0000Z-110821T2015Z/
HARTFORD CT-
409 PM EDT SUN AUG 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL HARTFORD COUNTY WILL
EXPIRE AT 415 PM EDT...

THE THUNDERSTORM HAS WEAKENED ACROSS THE WARNED AREA. LOCATIONS 
WITHIN AND TO THE EAST OF EAST-CENTRAL HARTFORD COUNTY CAN EXPECT 
HEAVY RAINS...FREQUENT LIGHTNING...AND GUSTY WINDS UP TO 30 MPH WITH 
THIS STORM. 

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT SUNDAY
EVENING FOR NORTHERN CONNECTICUT AND MASSACHUSETTS AND SOUTHERN NEW
HAMPSHIRE.

LAT...LON 4197 7250 4195 7249 4194 7251 4186 7252
      4181 7251 4181 7248 4180 7247 4168 7245
      4167 7244 4166 7244 4166 7260 4166 7276
      4185 7287
TIME...MOT...LOC 2008Z 253DEG 26KT 4180 7257

$$

SIPPRELL

The office that day

Everything else NWS Boston/Norton, MA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 21, 1:39 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region66 min
Aug 21, 3:15 PM EDTSpecial Weather StatementBOX45 min

Nearby

Severe Thunderstorm Warnings in Connecticut, 2011Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.