Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 21, NWS Boston/Norton, MA

June 22, 20214 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 22, 2021, 2:00 PM EDT for 4 counties in Massachusetts. It was in force for 45 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
Jun 22, 2021, 2:00 PM EDT (18:00 UTC)
Expired
Jun 22, 2021, 2:45 PM EDT
In force
45 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Bristol County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA

The radar

The Boston radar (KBOX), 34 km from the middle of the area, began a volume at 18:00 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 nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 6.0 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-pSkew-T log-p diagram, Gray, ME at 12:00Z on 2021-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 47 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, Gray, ME at 12:00Z on 2021-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 square meters per square second.193958Sfc1 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
47 J/kg
Mixed-layer CIN
-102 J/kg
Mixed-layer LCL
851 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

815 
WUUS51 KBOX 221800
SVRBOX
MAC005-021-023-025-221845-
/O.NEW.KBOX.SV.W.0021.210622T1800Z-210622T1845Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
200 PM EDT Tue Jun 22 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  South central Suffolk County in eastern Massachusetts...
  Eastern Norfolk County in eastern Massachusetts...
  Northwestern Plymouth County in southeastern Massachusetts...
  Northwestern Bristol County in southeastern Massachusetts...

* Until 245 PM EDT.

* At 200 PM EDT, a severe thunderstorm was located near Norton, or
  near North Attleborough, moving northeast at 55 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, Brockton, Quincy, Taunton, Weymouth, Braintree, Randolph,
  North Attleborough, Norwood, Milton, Stoughton, Attleboro, Dedham,
  Mansfield, Easton, Hingham, Canton, Norton, Scituate and Sharon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4232 7105 4230 7105 4230 7100 4229 7102
      4227 7099 4228 7095 4225 7096 4226 7091
      4225 7088 4227 7088 4228 7090 4228 7088
      4226 7086 4224 7077 4221 7073 4186 7125
      4192 7136 4233 7108
TIME...MOT...LOC 1800Z 216DEG 47KT 4195 7124 

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

BW
1 follow-up statement
089 
WWUS51 KBOX 221817
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
217 PM EDT Tue Jun 22 2021

MAC005-021-023-025-221845-
/O.CON.KBOX.SV.W.0021.000000T0000Z-210622T1845Z/
Suffolk MA-Norfolk MA-Plymouth MA-Bristol MA-
217 PM EDT Tue Jun 22 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM EDT
FOR SOUTHEASTERN SUFFOLK...EASTERN NORFOLK...NORTHWESTERN PLYMOUTH
AND NORTH CENTRAL BRISTOL COUNTIES...

At 217 PM EDT, a severe thunderstorm was located over Avon, or over
Stoughton, moving northeast at 55 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, Brockton, Quincy, Taunton, Weymouth, Braintree, Randolph,
Milton, Stoughton, Mansfield, Easton, Hingham, Canton, Norton,
Scituate, Sharon, Rockland, Foxborough, Abington and Whitman.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4230 7100 4229 7102 4227 7099 4228 7095
      4225 7096 4226 7091 4225 7088 4227 7088
      4228 7090 4228 7088 4226 7086 4224 7077
      4221 7073 4192 7116 4199 7124 4230 7105
TIME...MOT...LOC 1817Z 216DEG 47KT 4213 7106 

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

BW

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 10:50 PM EDTSpecial Weather StatementBOXFranklin40 min
Jun 22, 3:38 AM EDTRip Current StatementBOXDukes, Nantucket15 hr
Jun 22, 1:52 PM EDTSevere Thunderstorm WarningBOXBristol38 min
Jun 22, 2:14 PM EDTSpecial Marine WarningBOX31 min
Jun 22, 2:33 PM EDTSpecial Weather StatementBOXPlymouth42 min
Jun 22, 2:43 PM EDTSpecial Weather StatementBOXPlymouth32 min
Jun 22, 3:06 PM EDTSevere Thunderstorm WarningBOXBristol, Plymouth23 min
Jun 22, 3:07 PM EDTSpecial Marine WarningBOX53 min
Jun 22, 3:41 PM EDTSpecial Marine WarningBOX64 min
Jun 22, 4:42 PM EDTSpecial Weather StatementBOXNorfolk, Suffolk48 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.