Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 23, NWS Boston/Norton, MA

June 29, 2021Northeastern Connecticut Planning Region, Connecticut; Bristol County, Norfolk County, Worcester County, Massachusetts; Providence County, Rhode Island

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 29, 2021, 6:11 PM EDT for Northeastern Connecticut Planning Region, Connecticut; Bristol County, Norfolk County, Worcester County, Massachusetts; Providence County, Rhode Island. It was in force for 64 min. 2 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
Jun 29, 2021, 6:11 PM EDT (22:11 UTC)
Expired
Jun 29, 2021, 7:15 PM EDT
In force
64 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Northeastern Connecticut Planning Region, CT, Bristol County, MA, Norfolk County, MA, Worcester County, MA, Providence County, RI

The radar

The Boston radar (KBOX), 30 km from the middle of the area, began a volume at 22:14 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
Jun 29, 6:20 PM EDTTSTM WND DMGWoodstock, CTMULTIPLE TREES DOWN OF RTE169 AT DODGE ROAD
Jun 29, 6:25 PM EDTTSTM WND DMGWebster, MAWIRES DOWN MAKING LAKE PARKWAY IMPASSABLE

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.2 hours before the alert went out and 167 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 2021-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 681 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 2021-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 132 square meters per square second.1939Sfc1 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
681 J/kg
Mixed-layer CIN
-118 J/kg
Mixed-layer LCL
1052 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
132 m²/s²
0-3 km storm-relative helicity
179 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

591 
WUUS51 KBOX 292211
SVRBOX
CTC015-MAC005-021-027-RIC007-292315-
/O.NEW.KBOX.SV.W.0023.210629T2211Z-210629T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
611 PM EDT Tue Jun 29 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northeastern Windham County in northern Connecticut...
  Southwestern Norfolk County in eastern Massachusetts...
  Southeastern Worcester County in central Massachusetts...
  Northwestern Bristol County in southeastern Massachusetts...
  Northern Providence County in Rhode Island...

* Until 715 PM EDT.

* At 610 PM EDT, a severe thunderstorm was located over Webster, or
  16 miles south of Worcester, 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...
  Providence, Pawtucket, East Providence, Woonsocket, Cumberland,
  North Providence, Franklin, Johnston, North Attleborough, Milford,
  Attleboro, Walpole, Mansfield, Smithfield, Lincoln, Central Falls,
  Grafton, Killingly, Foxborough and Webster.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4210 7123 4183 7136 4183 7137 4186 7138
      4183 7138 4193 7208 4222 7193
TIME...MOT...LOC 2210Z 284DEG 28KT 4204 7185 

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

Loconto
3 follow-up statements
473 
WWUS51 KBOX 292235
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
635 PM EDT Tue Jun 29 2021

CTC015-MAC005-021-027-RIC007-292315-
/O.CON.KBOX.SV.W.0023.000000T0000Z-210629T2315Z/
Windham CT-Norfolk MA-Worcester MA-Bristol MA-Providence RI-
635 PM EDT Tue Jun 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR NORTHEASTERN WINDHAM...SOUTHWESTERN NORFOLK...SOUTHEASTERN
WORCESTER...NORTHWESTERN BRISTOL AND NORTHERN PROVIDENCE COUNTIES...

At 633 PM EDT, a severe thunderstorm was located near Burrillville,
or 7 miles west of Woonsocket, moving east at 30 mph.

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

SOURCE...Trained spotters and broadcast media. At 620 PM, multiple 
         trees were downed on Route 169 in Woodstock, CT.

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

Locations impacted include...
Providence, Pawtucket, East Providence, Woonsocket, Cumberland, North
Providence, Franklin, Johnston, North Attleborough, Milford,
Attleboro, Walpole, Mansfield, Smithfield, Lincoln, Central Falls,
Grafton, Killingly, Foxborough and Webster.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4210 7123 4183 7136 4183 7137 4186 7138
      4183 7138 4193 7208 4220 7181
TIME...MOT...LOC 2233Z 283DEG 27KT 4200 7164 

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

Loconto
485 
WWUS51 KBOX 292302
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
702 PM EDT Tue Jun 29 2021

CTC015-MAC005-021-027-RIC007-292315-
/O.CON.KBOX.SV.W.0023.000000T0000Z-210629T2315Z/
Windham CT-Norfolk MA-Worcester MA-Bristol MA-Providence RI-
702 PM EDT Tue Jun 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR NORTHEASTERN WINDHAM...SOUTHWESTERN NORFOLK...SOUTHEASTERN
WORCESTER...NORTHWESTERN BRISTOL AND NORTHERN PROVIDENCE COUNTIES...

At 701 PM EDT, a severe thunderstorm was located over North
Smithfield, or near Woonsocket, moving east at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Trained weather spotters. Numerous trees and power lines 
         have been downed in the towns of Woodstock and Webster from 
         these storms.

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

Locations impacted include...
Providence, Pawtucket, East Providence, Woonsocket, Cumberland, North
Providence, Franklin, Johnston, North Attleborough, Attleboro,
Smithfield, Lincoln, Central Falls, Killingly, Webster, Bellingham,
Burrillville, Northbridge, Oxford and Uxbridge.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4209 7134 4183 7136 4183 7137 4186 7138
      4183 7138 4193 7203 4214 7184
TIME...MOT...LOC 2301Z 285DEG 23KT 4196 7150 

HAIL...<.75IN
WIND...60MPH
 
$$

Loconto
651 
WWUS51 KBOX 292308
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
708 PM EDT Tue Jun 29 2021

CTC015-MAC005-021-027-RIC007-292318-
/O.EXP.KBOX.SV.W.0023.000000T0000Z-210629T2315Z/
Windham CT-Norfolk MA-Worcester MA-Bristol MA-Providence RI-
708 PM EDT Tue Jun 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WINDHAM...
SOUTHWESTERN NORFOLK...SOUTHEASTERN WORCESTER...NORTHWESTERN BRISTOL
AND NORTHERN PROVIDENCE COUNTIES WILL EXPIRE AT 715 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 4209 7134 4183 7136 4183 7137 4186 7138
      4183 7138 4193 7203 4214 7184
TIME...MOT...LOC 2308Z 284DEG 28KT 4196 7151 

$$

Loconto

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 6:48 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region57 min
Jun 29, 6:59 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region44 min
Jun 29, 7:34 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region, Northeastern Connecticut Planning Region56 min
Jun 29, 2:26 AM EDTSmall Craft AdvisoryBOX8 hr
Jun 29, 4:44 PM EDTSpecial Weather StatementBOXHampden31 min
Jun 29, 5:00 PM EDTSpecial Weather StatementBOXNorfolk45 min
Jun 29, 5:34 PM EDTSpecial Weather StatementBOXWorcester41 min
Jun 29, 5:56 PM EDTSpecial Weather StatementBOXFranklin49 min
Jun 29, 6:03 PM EDTSpecial Weather StatementBOXPlymouth42 min
Jun 29, 6:07 PM EDTSpecial Weather StatementBOXHampden, Hampshire38 min
Jun 29, 6:28 PM EDTSpecial Marine WarningBOX47 min
Jun 29, 6:32 PM EDTSpecial Weather StatementBOXHampden43 min
Jun 29, 7:22 PM EDTSpecial Weather StatementBOXHampshire53 min
Jun 29, 7:54 PM EDTSpecial Weather StatementBOXWorcester51 min
Jun 29, 7:10 PM EDTSpecial Weather StatementBOXProvidence50 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2021Severe Thunderstorm Warnings in Connecticut, 2021Severe Thunderstorm Warnings in Rhode Island, 2021Every 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.