Alert archive / Connecticut / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 59, NWS Boston/Norton, MA

July 7, 2021Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut; Hampden County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 7, 2021, 5:30 PM EDT for Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut; Hampden County, Worcester County, Massachusetts. It was in force for 60 min. 8 reports 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: Jul 7, 2021, 5:30 PM EDT (21:30 UTC)
Expired: Jul 7, 2021, 6:30 PM EDT
In force: 60 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, Hampden County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 91 km from the middle of the area, began a volume at 21:31 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

Time	Report	Where	Remark
Jul 7, 5:30 PM EDT	TSTM WND DMG	Bolton, CT	LARGE TREE BLOCKING RTE 85 AT RIGA LANE
Jul 7, 5:30 PM EDT	TSTM WND DMG	Somers, CT	TREE AND WIRES DOWN ON HALL HILL ROAD
Jul 7, 5:35 PM EDT	TSTM WND DMG	Ellington, CT	TREE DOWN ON A HOUSE ON PINNACLE ROAD
Jul 7, 5:52 PM EDT	TSTM WND DMG	Stafford, CT	TREES AND WIRES DOWN ON NEW CITY ROAD
Jul 7, 5:55 PM EDT	TSTM WND DMG	Columbia, CT	TREES AND WIRES DOWN ON OLD WILLIMANTIC ROAD
Jul 7, 6:00 PM EDT	TSTM WND DMG	Storrs, CT	MULTIPLE TREES AND WIRES DOWN ON ROCKRIDGE ROAD AT RTE 195
Jul 7, 6:10 PM EDT	TSTM WND DMG	Woodstock, CT	MULTIPLE TREES DOWN ON BRICKYARD ROAD
Jul 7, 6:29 PM EDT	TSTM WND GST 60	Webster, MA

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.

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, 9.5 hours before the alert went out and 116 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.

783 
WUUS51 KBOX 072130
SVRBOX
CTC003-013-015-MAC013-027-072230-
/O.NEW.KBOX.SV.W.0059.210707T2130Z-210707T2230Z/

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

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Windham County in northern Connecticut...
  Tolland County in northern Connecticut...
  East central Hartford County in northern Connecticut...
  Southwestern Worcester County in central Massachusetts...
  Southeastern Hampden County in western Massachusetts...

* Until 630 PM EDT.

* At 529 PM EDT, severe thunderstorms were located along a line
  extending from near Monson to Ellington to Glastonbury, 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...
  Manchester, East Hartford, Enfield, Glastonbury, Vernon,
  Wethersfield, Mansfield, South Windsor, Windham, Plainfield, Rocky
  Hill, Willimantic, Killingly, Webster, Southbridge, East
  Longmeadow, Ellington, Tolland, Wilbraham and Oxford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4219 7239 4210 7178 4177 7189 4164 7198
      4166 7213 4166 7216 4171 7224 4169 7227
      4167 7227 4164 7233 4161 7233 4168 7264
TIME...MOT...LOC 2129Z 280DEG 25KT 4213 7234 4191 7245 4167 7257 

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

Chai

2 follow-up statements

312 
WWUS51 KBOX 072157
SVSBOX

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

CTC003-013-015-MAC013-027-072230-
/O.CON.KBOX.SV.W.0059.000000T0000Z-210707T2230Z/
Windham CT-Tolland CT-Hartford CT-Worcester MA-Hampden MA-
557 PM EDT Wed Jul 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR WINDHAM...TOLLAND...EASTERN HARTFORD...SOUTH CENTRAL WORCESTER
AND SOUTHEASTERN HAMPDEN COUNTIES...

At 556 PM EDT, severe thunderstorms were located along a line
extending from Sturbridge to near Ashford to near Hebron, moving east
at 30 mph.

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

SOURCE...Radar indicated. 53 kt gust reported at BDL at 512 PM. This 
         storm also has a history of producing tree damage. 

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

Locations impacted include...
Mansfield, Windham, Plainfield, Willimantic, Killingly, Webster,
Southbridge, Ellington, Tolland, Oxford, Charlton, Coventry,
Stafford, Dudley, Hebron, Putnam, Thompson, Sturbridge, Monson and
Douglas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4216 7224 4210 7178 4177 7189 4164 7198
      4166 7213 4166 7216 4171 7224 4169 7227
      4167 7227 4164 7233 4161 7233 4164 7246
TIME...MOT...LOC 2156Z 280DEG 25KT 4210 7209 4188 7220 4164 7232 

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

Chai

154 
WWUS51 KBOX 072225
SVSBOX

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

CTC003-013-015-MAC013-027-072234-
/O.EXP.KBOX.SV.W.0059.000000T0000Z-210707T2230Z/
Windham CT-Tolland CT-Hartford CT-Worcester MA-Hampden MA-
625 PM EDT Wed Jul 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR WINDHAM...TOLLAND...EASTERN
HARTFORD...SOUTH CENTRAL WORCESTER AND SOUTHEASTERN HAMPDEN COUNTIES
WILL EXPIRE AT 630 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
northern Connecticut...and western and central Massachusetts.

LAT...LON 4216 7224 4210 7178 4177 7189 4164 7198
      4166 7213 4166 7216 4171 7224 4169 7227
      4167 7227 4164 7233 4161 7233 4164 7246
TIME...MOT...LOC 2224Z 270DEG 25KT 4209 7184 4187 7195 4163 7207 

$$

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, 5:53 PM EDT	Special Weather Statement	BOX		52 min
Jul 7, 6:17 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	58 min
Jul 7, 6:38 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	43 min
Jul 7, 4:01 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampshire	59 min
Jul 7, 4:05 PM EDT	Special Weather Statement	BOX	Essex	40 min
Jul 7, 4:33 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	57 min
Jul 7, 5:02 PM EDT	Special Weather Statement	BOX	Worcester	43 min
Jul 7, 5:05 PM EDT	Special Marine Warning	BOX		25 min
Jul 7, 5:10 PM EDT	Tropical Storm Watch	BOX	Barnstable, Bristol, Dukes, Nantucket, Plymouth	13 hr
Jul 7, 5:21 PM EDT	Severe Thunderstorm Warning	BOX	Hampden, Hampshire, Worcester	54 min
Jul 7, 5:24 PM EDT	Special Marine Warning	BOX		66 min
Jul 7, 6:01 PM EDT	Special Weather Statement	BOX	Worcester	44 min
Jul 7, 6:18 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	36 min
Jul 7, 6:22 PM EDT	Special Marine Warning	BOX		53 min
Jul 7, 6:59 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Middlesex, Norfolk, Plymouth, Suffolk	61 min
Jul 7, 7:18 PM EDT	Special Marine Warning	BOX		57 min
Jul 7, 7:47 PM EDT	Severe Thunderstorm Warning	BOX	Norfolk, Plymouth	25 min
Jul 7, 7:51 PM EDT	Special Marine Warning	BOX		54 min

Nearby

Severe Thunderstorm Warnings in Connecticut, 2021 Severe Thunderstorm Warnings in Massachusetts, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.