Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 37, NWS Boston/Norton, MA

June 30, 20215 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 30, 2021, 6:12 PM EDT for 5 counties in Massachusetts. It was in force for 47 min. 3 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, 6:12 PM EDT (22:12 UTC)
Expired: Jun 30, 2021, 6:59 PM EDT
In force: 47 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 34 km from the middle of the area, began a volume at 22:11 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, 6:27 PM EDT	TSTM WND DMG	Hopkinton, MA	TREES DOWN ON EASTVIEW STREET, HAYDEN ROWE, AND KERRY LANE
Jun 30, 6:43 PM EDT	TSTM WND DMG	Quincy, MA	TREES DOWN ON HOLBROOK ROAD AT NEWPORT AVE. TREE DOWN ON WARREN AVE
Jun 30, 7:00 PM EDT	TSTM WND DMG	Hingham, MA	POWER LINES DOWN ON BEAL 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.

Issued	Product	Office	Lasted
Jun 30, 3:21 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 10.2 hours before the alert went out and 193 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: 906 J/kg
Mixed-layer CIN: -60 J/kg
Mixed-layer LCL: 1312 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 95 m²/s²
0-3 km storm-relative helicity: 102 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.3

Open this sounding in Storm Lab

The text

As transmitted.

014 
WUUS51 KBOX 302212
SVRBOX
MAC017-021-023-025-027-302315-
/O.NEW.KBOX.SV.W.0037.210630T2212Z-210630T2315Z/

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

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Southwestern Suffolk County in eastern Massachusetts...
  Central Norfolk County in eastern Massachusetts...
  Southeastern Worcester County in central Massachusetts...
  South central Middlesex County in northeastern Massachusetts...
  North central Plymouth County in southeastern Massachusetts...

* Until 715 PM EDT.

* At 612 PM EDT, a severe thunderstorm was located over Upton, or
  near Milford, moving east at 40 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...
  Boston, Quincy, Framingham, Weymouth, Braintree, Shrewsbury,
  Natick, Randolph, Needham, Norwood, Milford, Wellesley, Milton,
  Stoughton, Dedham, Walpole, Hingham, Canton, Westborough and
  Grafton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4226 7087 4227 7085 4215 7088 4213 7167
      4227 7170 4229 7101 4226 7097 4229 7094
      4225 7096 4227 7093 4225 7088 4228 7090
      4228 7088
TIME...MOT...LOC 2212Z 271DEG 36KT 4218 7158 

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

Frank

3 follow-up statements

552 
WWUS51 KBOX 302236
SVSBOX

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

MAC017-021-023-025-027-302315-
/O.CON.KBOX.SV.W.0037.000000T0000Z-210630T2315Z/
Suffolk MA-Norfolk MA-Worcester MA-Middlesex MA-Plymouth MA-
636 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR SOUTHWESTERN SUFFOLK...CENTRAL NORFOLK...EASTERN WORCESTER...
SOUTH CENTRAL MIDDLESEX AND NORTH CENTRAL PLYMOUTH COUNTIES...

At 636 PM EDT, a severe thunderstorm was located over Westwood, or
near Norwood, moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Boston, Quincy, Framingham, Weymouth, Braintree, Natick, Randolph,
Needham, Norwood, Milford, Wellesley, Milton, Stoughton, Dedham,
Walpole, Hingham, Canton, Sharon, Rockland and Ashland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4226 7087 4227 7085 4215 7088 4214 7152
      4227 7146 4229 7101 4226 7097 4229 7094
      4225 7096 4227 7093 4225 7088 4228 7090
      4228 7088
TIME...MOT...LOC 2236Z 276DEG 28KT 4220 7126 

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

Frank

260 
WWUS51 KBOX 302250
SVSBOX

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

MAC027-302300-
/O.CAN.KBOX.SV.W.0037.000000T0000Z-210630T2315Z/
Worcester MA-
650 PM EDT Wed Jun 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN WORCESTER 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 1000 PM EDT for
eastern, southeastern and northeastern Massachusetts.

LAT...LON 4226 7087 4227 7085 4215 7088 4215 7144
      4227 7131 4229 7101 4226 7097 4229 7094
      4225 7096 4227 7093 4225 7088 4228 7090
      4228 7088
TIME...MOT...LOC 2250Z 271DEG 36KT 4220 7106 

$$

MAC017-021-023-025-302315-
/O.CON.KBOX.SV.W.0037.000000T0000Z-210630T2315Z/
Suffolk MA-Norfolk MA-Middlesex MA-Plymouth MA-
650 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR SOUTHWESTERN SUFFOLK...CENTRAL NORFOLK...SOUTHERN MIDDLESEX AND
NORTH CENTRAL PLYMOUTH COUNTIES...

At 650 PM EDT, a severe thunderstorm was located over Randolph,
moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Boston, Quincy, Weymouth, Braintree, Natick, Randolph, Needham,
Norwood, Milton, Stoughton, Dedham, Walpole, Hingham, Canton, Sharon,
Rockland, Westwood, Hanover, Holliston and Medway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4226 7087 4227 7085 4215 7088 4215 7144
      4227 7131 4229 7101 4226 7097 4229 7094
      4225 7096 4227 7093 4225 7088 4228 7090
      4228 7088
TIME...MOT...LOC 2250Z 271DEG 36KT 4220 7106 

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

Frank

169 
WWUS51 KBOX 302259
SVSBOX

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

MAC017-021-023-025-302309-
/O.CAN.KBOX.SV.W.0037.000000T0000Z-210630T2315Z/
Suffolk MA-Norfolk MA-Middlesex MA-Plymouth MA-
659 PM EDT Wed Jun 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUFFOLK...CENTRAL
NORFOLK...SOUTHERN MIDDLESEX AND NORTH CENTRAL PLYMOUTH COUNTIES IS
CANCELLED...
                
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 has been cancelled.  However gusty winds are
still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
eastern, southeastern and northeastern Massachusetts.

LAT...LON 4226 7087 4227 7085 4215 7088 4215 7144
      4227 7131 4229 7101 4226 7097 4229 7094
      4225 7096 4227 7093 4225 7088 4228 7090
      4228 7088
TIME...MOT...LOC 2258Z 271DEG 36KT 4220 7093 

$$

Frank

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 2:29 AM EDT	Small Craft Advisory	BOX		18 hr
Jun 30, 3:40 PM EDT	Special Weather Statement	BOX	Hampshire	65 min
Jun 30, 3:42 PM EDT	Special Weather Statement	BOX	Franklin	63 min
Jun 30, 3:48 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire	57 min
Jun 30, 4:03 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampshire	57 min
Jun 30, 4:32 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Middlesex, Worcester	58 min
Jun 30, 4:39 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire, Worcester	66 min
Jun 30, 4:45 PM EDT	Tornado Warning	BOX	Franklin, Worcester	26 min
Jun 30, 5:00 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	30 min
Jun 30, 5:13 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	62 min
Jun 30, 5:25 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	49 min
Jun 30, 5:26 PM EDT	Special Marine Warning	BOX		64 min
Jun 30, 5:29 PM EDT	Severe Thunderstorm Warning	BOX	Worcester	44 min
Jun 30, 5:43 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	51 min
Jun 30, 5:54 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Norfolk, Suffolk, Worcester	53 min
Jun 30, 5:58 PM EDT	Special Marine Warning	BOX		62 min
Jun 30, 6:11 PM EDT	Special Weather Statement	BOX	Norfolk	49 min
Jun 30, 6:22 PM EDT	Special Marine Warning	BOX		53 min
Jun 30, 6:31 PM EDT	Special Marine Warning	BOX		59 min
Jun 30, 6:45 PM EDT	Severe Thunderstorm Warning	BOX	Hampden	60 min
Jun 30, 6:57 PM EDT	Special Marine Warning	BOX		33 min
Jun 30, 7:15 PM EDT	Severe Thunderstorm Warning	BOX	Hampden, Worcester	60 min

Nearby

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.