Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 50, NWS Boston/Norton, MA

July 6, 20214 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 6, 2021, 5:13 PM EDT for 4 counties in Massachusetts. It was in force for 62 min. 6 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 6, 2021, 5:13 PM EDT (21:13 UTC)
Expired
Jul 6, 2021, 6:15 PM EDT
In force
62 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Essex County, MA, Middlesex County, MA, Suffolk County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 47 km from the middle of the area, began a volume at 21:12 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
Jul 6, 5:20 PM EDTTSTM WND DMGActon, MATREE DOWN ON HOUSE ON JASMINE CIRCLE
Jul 6, 5:20 PM EDTTSTM WND DMGActon, MATREES AND WIRES DOWN ON MAIN STREET AND ON CENTRAL STREET
Jul 6, 5:20 PM EDTTSTM WND DMGActon, MATREES DOWN ON POPE ROAD AND RTE 2A
Jul 6, 5:30 PM EDTTSTM WND DMGConcord, MATREE DOWN ON CAR ON ELM STREETAT PARK LANE. TREES DOWN ON LEXINGTON ROAD, NEAR THE CONCORD AND LINCOIN LINE
Jul 6, 5:50 PM EDTTSTM WND DMGArlington, MAMULTIPLE TREES DOWN ACROSS TOWN INCLUDING TREEE DOWN ONTO A CAR ON CLEVELAND STREET
Jul 6, 5:56 PM EDTTSTM WND DMGSaugus, MATREE DOWN ON LINCION AVE

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.

IssuedProductOfficeLasted
Jul 6, 1:13 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 9.2 hours before the alert went out and 181 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 2021-07-06Temperature 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 2021-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 152 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
-182 J/kg
Mixed-layer LCL
717 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

424 
WUUS51 KBOX 062113
SVRBOX
MAC009-017-025-027-062215-
/O.NEW.KBOX.SV.W.0050.210706T2113Z-210706T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
513 PM EDT Tue Jul 6 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Suffolk County in eastern Massachusetts...
  South central Essex County in northeastern Massachusetts...
  East central Worcester County in central Massachusetts...
  East central Middlesex County in northeastern Massachusetts...

* Until 615 PM EDT.

* At 512 PM EDT, a severe thunderstorm was located over Stow, or near
  Marlborough, 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...
  Boston, Cambridge, Lynn, Newton, Somerville, Framingham, Waltham,
  Malden, Brookline, Medford, Revere, Arlington, Everett, Billerica,
  Marlborough, Woburn, Chelsea, Natick, Watertown and Lexington.

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 4247 7089 4246 7094 4243 7093 4245 7094
      4245 7097 4241 7099 4233 7089 4238 7105
      4233 7101 4232 7101 4233 7102 4233 7103
      4228 7104 4225 7111 4233 7125 4232 7132
      4229 7132 4235 7168 4257 7154
TIME...MOT...LOC 2112Z 281DEG 26KT 4244 7152 

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

Frank
1 follow-up statement
368 
WWUS51 KBOX 062144
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
544 PM EDT Tue Jul 6 2021

MAC027-062153-
/O.CAN.KBOX.SV.W.0050.000000T0000Z-210706T2215Z/
Worcester MA-
544 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL 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 800 PM EDT for
eastern and northeastern Massachusetts.

LAT...LON 4237 7133 4252 7129 4249 7103 4247 7089
      4246 7094 4243 7093 4245 7094 4245 7097
      4241 7099 4233 7089 4238 7105 4233 7101
      4232 7101 4233 7102 4233 7103 4228 7104
      4227 7105
TIME...MOT...LOC 2143Z 281DEG 26KT 4240 7122 

$$

MAC009-017-025-062215-
/O.CON.KBOX.SV.W.0050.000000T0000Z-210706T2215Z/
Suffolk MA-Essex MA-Middlesex MA-
544 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR SUFFOLK...SOUTH CENTRAL ESSEX AND EAST CENTRAL MIDDLESEX
COUNTIES...

At 543 PM EDT, a severe thunderstorm was located over Waltham, 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...
Boston, Cambridge, Lynn, Newton, Somerville, Waltham, Malden,
Brookline, Medford, Revere, Arlington, Everett, Woburn, Chelsea,
Watertown, Lexington, Milton, Melrose, Saugus and Wakefield.

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 4237 7133 4252 7129 4249 7103 4247 7089
      4246 7094 4243 7093 4245 7094 4245 7097
      4241 7099 4233 7089 4238 7105 4233 7101
      4232 7101 4233 7102 4233 7103 4228 7104
      4227 7105
TIME...MOT...LOC 2143Z 281DEG 26KT 4240 7122 

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

RM

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 1:42 AM EDTSpecial Weather StatementBOXFranklin33 min
Jul 6, 1:57 AM EDTSpecial Weather StatementBOXFranklin33 min
Jul 6, 2:20 AM EDTSpecial Weather StatementBOXFranklin25 min
Jul 6, 2:34 AM EDTSpecial Weather StatementBOXWorcester41 min
Jul 6, 3:33 AM EDTHeat AdvisoryBOXBristol, Essex, Franklin, Hampden, Hampshire, Middlesex and 4 more39 hr
Jul 6, 2:14 PM EDTSpecial Weather StatementBOXFranklin46 min
Jul 6, 3:02 PM EDTSpecial Weather StatementBOXHampshire43 min
Jul 6, 3:06 PM EDTSpecial Weather StatementBOXHampden39 min
Jul 6, 3:12 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire63 min
Jul 6, 3:36 PM EDTSpecial Weather StatementBOXHampden39 min
Jul 6, 3:49 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampshire, Worcester56 min
Jul 6, 4:13 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester40 min
Jul 6, 4:20 PM EDTSevere Thunderstorm WarningBOXHampden, Hampshire55 min
Jul 6, 4:42 PM EDTSpecial Weather StatementBOXMiddlesex, Worcester48 min
Jul 6, 4:43 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester62 min
Jul 6, 4:51 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester33 min
Jul 6, 5:16 PM EDTSpecial Marine WarningBOX44 min
Jul 6, 5:19 PM EDTSpecial Weather StatementBOXEssex41 min
Jul 6, 5:21 PM EDTSpecial Marine WarningBOX39 min
Jul 6, 5:21 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Worcester42 min
Jul 6, 5:52 PM EDTSevere Thunderstorm WarningBOXBristol, Middlesex, Norfolk, Worcester53 min
Jul 6, 5:54 PM EDTSpecial Marine WarningBOX66 min
Jul 6, 5:57 PM EDTSpecial Marine WarningBOX48 min
Jul 6, 6:00 PM EDTSpecial Weather StatementBOXEssex30 min
Jul 6, 6:07 PM EDTSpecial Marine WarningBOX23 min
Jul 6, 6:13 PM EDTSevere Thunderstorm WarningBOXBristol, Middlesex, Norfolk, Plymouth, Suffolk31 min
Jul 6, 6:37 PM EDTSpecial Marine WarningBOX23 min
Jul 6, 6:45 PM EDTSpecial Weather StatementBOXBristol, Plymouth45 min
Jul 6, 6:52 PM EDTSpecial Marine WarningBOX53 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.