Alert archive / Connecticut / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 62, NWS Boston/Norton, MA

July 7, 2021Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 7, 2021, 6:38 PM EDT for Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 7, 2021, 6:38 PM EDT (22:38 UTC)
Expired: Jul 7, 2021, 7:21 PM EDT
In force: 43 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT

The radar

The Boston radar (KBOX), 103 km from the middle of the area, began a volume at 22:38 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.

The watch it was issued in

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

Issued	Product	Office	Lasted
Jul 7, 2:41 PM EDT	Severe Thunderstorm Watch	SPC	10 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.6 hours before the alert went out and 106 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 568 J/kg
Mixed-layer CIN: -83 J/kg
Mixed-layer LCL: 901 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 79 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

392 
WUUS51 KBOX 072238
SVRBOX
CTC003-013-015-072345-
/O.NEW.KBOX.SV.W.0062.210707T2238Z-210707T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
638 PM EDT Wed Jul 7 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Southwestern Windham County in northern Connecticut...
  Central Tolland County in northern Connecticut...
  East central Hartford County in northern Connecticut...

* Until 745 PM EDT.

* At 637 PM EDT, a severe thunderstorm was located over Manchester,
  moving east at 30 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines.

* Locations impacted include...
  Hartford, Manchester, East Hartford, Glastonbury, Vernon, Windsor,
  Wethersfield, Mansfield, South Windsor, Windham, Willimantic,
  Ellington, Tolland, Windsor Locks, Coventry, East Windsor, Hebron,
  Marlborough, Willington and Columbia.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4191 7264 4187 7206 4166 7210 4166 7216
      4171 7224 4169 7227 4167 7227 4165 7232
      4163 7233 4172 7270
TIME...MOT...LOC 2237Z 279DEG 28KT 4179 7257 

HAIL...0.75IN
WIND...60MPH
 
$$

Chai

2 follow-up statements

019 
WWUS51 KBOX 072306
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
706 PM EDT Wed Jul 7 2021

CTC003-072315-
/O.CAN.KBOX.SV.W.0062.000000T0000Z-210707T2345Z/
Hartford CT-
706 PM EDT Wed Jul 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL HARTFORD COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
northern Connecticut.

LAT...LON 4189 7243 4187 7206 4166 7210 4166 7216
      4171 7224 4169 7227 4167 7227 4165 7232
      4163 7233 4165 7242 4167 7245
TIME...MOT...LOC 2305Z 270DEG 28KT 4176 7227 

$$

CTC013-015-072345-
/O.CON.KBOX.SV.W.0062.000000T0000Z-210707T2345Z/
Windham CT-Tolland CT-
706 PM EDT Wed Jul 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR SOUTHWESTERN WINDHAM AND CENTRAL TOLLAND COUNTIES...

At 705 PM EDT, a severe thunderstorm was located near Mansfield,
moving east at 30 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and power lines.

Locations impacted include...
Vernon, Mansfield, Windham, Willimantic, Tolland, Coventry, Hebron,
Marlborough, Willington, Columbia, Bolton, Ashford, Andover, Chaplin,
Hampton, Eastford and Scotland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4189 7243 4187 7206 4166 7210 4166 7216
      4171 7224 4169 7227 4167 7227 4165 7232
      4163 7233 4165 7242 4167 7245
TIME...MOT...LOC 2305Z 270DEG 28KT 4176 7227 

HAIL...0.75IN
WIND...60MPH
 
$$

Chai

509 
WWUS51 KBOX 072321
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
721 PM EDT Wed Jul 7 2021

CTC013-015-072331-
/O.CAN.KBOX.SV.W.0062.000000T0000Z-210707T2345Z/
Windham CT-Tolland CT-
721 PM EDT Wed Jul 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WINDHAM AND
CENTRAL TOLLAND COUNTIES IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
northern Connecticut.

LAT...LON 4189 7243 4187 7206 4166 7210 4166 7216
      4171 7224 4169 7227 4167 7227 4165 7232
      4163 7233 4165 7242 4167 7245
TIME...MOT...LOC 2320Z 279DEG 28KT 4174 7210 

$$

Chai

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 7, 4:00 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region	60 min
Jul 7, 4:50 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region	55 min
Jul 7, 5:30 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	60 min
Jul 7, 5:53 PM EDT	Special Weather Statement	BOX		52 min
Jul 7, 6:17 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	58 min

Nearby

Severe Thunderstorm Warnings in Connecticut, 2021 Every severe thunderstorm warning in 2021

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.