Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 40, NWS Boston/Norton, MA

June 30, 2021Northeastern Connecticut Planning Region, Connecticut; Providence County, Rhode Island; Bristol County, Norfolk County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 30, 2021, 8:08 PM EDT for Northeastern Connecticut Planning Region, Connecticut; Providence County, Rhode Island; Bristol County, Norfolk County, Worcester County, Massachusetts. It was in force for 67 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 30, 2021, 8:08 PM EDT (00:08 UTC)
Expired: Jun 30, 2021, 9:15 PM EDT
In force: 67 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 1.0 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), 51 km from the middle of the area, began a volume at 00:07 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
Jun 30, 8:33 PM EDT	TSTM WND DMG	Mansfield, MA	TREE AND WIRES DOWN ON PRATT STREET
Jun 30, 9:00 PM EDT	TSTM WND DMG	Norton, MA	POWER LINES DOWN KILYSYTH ROAD

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
Jun 30, 3:21 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.1 hours before the alert went out and 145 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: 1308 J/kg
Mixed-layer CIN: -130 J/kg
Mixed-layer LCL: 1402 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 99 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

742 
WUUS51 KBOX 010008
SVRBOX
CTC013-015-MAC005-021-027-RIC007-010115-
/O.NEW.KBOX.SV.W.0040.210701T0008Z-210701T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
808 PM EDT Wed Jun 30 2021

The National Weather Service in Boston/Norton has issued a

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

* Until 915 PM EDT.

* At 808 PM EDT, a severe thunderstorm was located over Mansfield,
  moving east at 30 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect wind damage to trees and power lines. Minor hail 
           damage to vehicles is possible.

* Locations impacted include...
  Providence, Cranston, Pawtucket, Taunton, East Providence,
  Woonsocket, Cumberland, North Providence, Franklin, Johnston, North
  Attleborough, Norwood, Milford, Windham, Plainfield, Attleboro,
  Walpole, Mansfield, Smithfield and Lincoln.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4198 7237 4220 7123 4180 7111 4178 7113
      4182 7139 4178 7149 4175 7210 4164 7241
TIME...MOT...LOC 0008Z 274DEG 27KT 4181 7222 

HAIL...1.00IN
WIND...60MPH
 
$$

Frank

1 follow-up statement

473 
WWUS51 KBOX 010038
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
838 PM EDT Wed Jun 30 2021

CTC013-015-MAC027-RIC007-010047-
/O.CAN.KBOX.SV.W.0040.000000T0000Z-210701T0115Z/
Windham CT-Tolland CT-Worcester MA-Providence RI-
838 PM EDT Wed Jun 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR WINDHAM...CENTRAL TOLLAND...
SOUTHEASTERN WORCESTER AND PROVIDENCE COUNTIES 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 1000 PM EDT for
eastern and southeastern Massachusetts.

LAT...LON 4180 7128 4217 7139 4220 7123 4180 7111
      4178 7113
TIME...MOT...LOC 0037Z 274DEG 27KT 4179 7193 

$$

MAC005-021-010115-
/O.CON.KBOX.SV.W.0040.000000T0000Z-210701T0115Z/
Norfolk MA-Bristol MA-
838 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM EDT
FOR SOUTHWESTERN NORFOLK AND NORTHWESTERN BRISTOL COUNTIES...

At 837 PM EDT, a severe thunderstorm was located over Brooklyn, or
near Plainfield, moving east at 30 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect wind damage to trees and power lines. Minor hail 
         damage to vehicles is possible.

Locations impacted include...
Taunton, Franklin, North Attleborough, Norwood, Attleboro, Walpole,
Mansfield, Norton, Somerset, Sharon, Foxborough, Swansea, Westwood,
Seekonk, Medfield, Rehoboth, Norfolk, Wrentham, Plainville and
Millis.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4180 7128 4217 7139 4220 7123 4180 7111
      4178 7113
TIME...MOT...LOC 0037Z 274DEG 27KT 4179 7193 

HAIL...1.00IN
WIND...60MPH
 
$$

Nocera

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 1, 4:01 PM EDT	Special Weather Statement	BOX	Bristol	59 min
Jun 30, 8:14 PM EDT	Severe Thunderstorm Warning	BOX	Norfolk, Plymouth, Suffolk	46 min
Jun 30, 8:16 PM EDT	Special Marine Warning	BOX		59 min
Jun 30, 8:31 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Norfolk, Plymouth	59 min
Jun 30, 8:41 PM EDT	Special Marine Warning	BOX		64 min
Jun 30, 8:57 PM EDT	Special Marine Warning	BOX		63 min
Jun 30, 9:54 PM EDT	Special Marine Warning	BOX		66 min
Jul 1, 4:02 PM EDT	Small Craft Advisory	BOX		4 days
Jul 1, 4:29 PM EDT	Special Marine Warning	BOX		61 min
Jul 1, 5:03 PM EDT	Special Weather Statement	BOX	Barnstable	42 min
Jul 1, 5:21 PM EDT	Special Marine Warning	BOX		54 min
Jul 1, 7:05 PM EDT	Special Weather Statement	BOX	Hampden	55 min
Jul 1, 7:59 PM EDT	Areal Flood Warning	BOX	Hampden, Hampshire	3 hr

Nearby

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