Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 53, NWS Boston/Norton, MA

July 6, 20215 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 6, 2021, 6:13 PM EDT for 5 counties in Massachusetts. It was in force for 31 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
Jul 6, 2021, 6:13 PM EDT (22:13 UTC)
Expired
Jul 6, 2021, 6:44 PM EDT
In force
31 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

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

The radar

The Boston radar (KBOX), 33 km from the middle of the area, began a volume at 22:17 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 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, 10.2 hours before the alert went out and 194 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.

027 
WUUS51 KBOX 062213
SVRBOX
MAC005-017-021-023-025-062315-
/O.NEW.KBOX.SV.W.0053.210706T2213Z-210706T2315Z/

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

The National Weather Service in Boston/Norton has issued a

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

* Until 715 PM EDT.

* At 612 PM EDT, severe thunderstorms were located along a line
  extending from near Maynard to near Holliston, moving southeast at
  25 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, Brockton, Quincy, Newton, Brookline, Taunton, Weymouth,
  Braintree, Natick, Randolph, Needham, Norwood, Wellesley, Milton,
  Stoughton, Bridgewater, Marshfield, Dedham, Walpole and Mansfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4229 7102 4227 7099 4228 7095 4225 7096
      4225 7088 4230 7091 4231 7091 4226 7087
      4220 7071 4217 7073 4215 7070 4178 7106
      4222 7143 4237 7133
TIME...MOT...LOC 2212Z 302DEG 23KT 4242 7141 4220 7150 

HAIL...0.75IN
WIND...60MPH
 
$$
RM
1 follow-up statement
495 
WWUS51 KBOX 062244
SVSBOX

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

MAC005-017-021-023-025-062254-
/O.CAN.KBOX.SV.W.0053.000000T0000Z-210706T2315Z/
Suffolk MA-Norfolk MA-Middlesex MA-Plymouth MA-Bristol MA-
644 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUFFOLK...
NORFOLK...SOUTHEASTERN MIDDLESEX...NORTHWESTERN PLYMOUTH AND NORTH
CENTRAL BRISTOL COUNTIES IS CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds are
still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
eastern and southeastern Massachusetts.

LAT...LON 4229 7102 4227 7099 4228 7095 4225 7096
      4225 7088 4230 7091 4231 7091 4226 7087
      4220 7071 4217 7073 4215 7070 4178 7106
      4222 7143 4237 7133
TIME...MOT...LOC 2243Z 302DEG 23KT 4231 7118 4209 7127 

$$
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, 5:13 PM EDTSevere Thunderstorm WarningBOXEssex, Middlesex, Suffolk, Worcester62 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, 6:37 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.