Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 48, NWS Boston/Norton, MA

July 6, 20214 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 6, 2021, 4:51 PM EDT for 4 counties in Massachusetts. It was in force for 33 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
Jul 6, 2021, 4:51 PM EDT (20:51 UTC)
Expired
Jul 6, 2021, 5:24 PM EDT
In force
33 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Franklin County, MA, Hampden County, MA, Hampshire County, MA, Worcester County, MA

The radar

The Albany radar (KENX), 102 km from the middle of the area, began a volume at 20:55 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, 5:07 PM EDTTSTM WND DMGBelchertown, MATREE DOWN ON WIRES ON HOWARD STREET
Jul 6, 5:23 PM EDTTSTM WND DMGRussell, MATREE AND WIRES DOWN ON RTE 23 AT RTE 20
Jul 6, 5:28 PM EDTTSTM WND DMGHuntington, MATREE AND WIRES DOWN BROMLEY 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.

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

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 8.9 hours before the alert went out and 89 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, Albany, NY at 12:00Z on 2021-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 326 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, Albany, NY at 12:00Z on 2021-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 182 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
326 J/kg
Mixed-layer CIN
-120 J/kg
Mixed-layer LCL
941 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
182 m²/s²
0-3 km storm-relative helicity
202 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

658 
WUUS51 KBOX 062051
SVRBOX
MAC011-013-015-027-062145-
/O.NEW.KBOX.SV.W.0048.210706T2051Z-210706T2145Z/

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

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Western Worcester County in central Massachusetts...
  Southern Hampshire County in western Massachusetts...
  Southeastern Franklin County in western Massachusetts...
  Central Hampden County in western Massachusetts...

* Until 545 PM EDT.

* At 451 PM EDT, a severe thunderstorm was located near Chester, or
  15 miles northwest of Westfield, 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...
  Springfield, Chicopee, Westfield, Holyoke, Amherst, Northampton,
  West Springfield, Ludlow, South Hadley, Easthampton, Belchertown,
  Wilbraham, Palmer, Ware, Monson, Granby, Southampton, Hadley,
  Hardwick and Huntington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and 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 4238 7307 4239 7305 4238 7301 4239 7301
      4233 7247 4232 7225 4211 7230 4217 7303
      4225 7300 4231 7300 4231 7303 4233 7306
TIME...MOT...LOC 2051Z 278DEG 27KT 4226 7301 

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

Loconto
3 follow-up statements
819 
WWUS51 KBOX 062053 RRA
SVSBOX

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

MAC011-013-015-027-062145-
/O.CON.KBOX.SV.W.0048.000000T0000Z-210706T2145Z/
Worcester MA-Hampshire MA-Franklin MA-Hampden MA-
453 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EDT
FOR WESTERN WORCESTER...SOUTHERN HAMPSHIRE...SOUTHEASTERN FRANKLIN
AND CENTRAL HAMPDEN COUNTIES...

At 453 PM EDT, a severe thunderstorm was located over Chester, or 14
miles northwest of Westfield, moving east at 30 mph.

This is a dangerous storm.

HAZARD...70 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable damage to trees and power lines. Wind 
         damage is also likely to mobile homes, roofs, and 
         outbuildings. Minor hail damage to vehicles is possible.

Locations impacted include...
Springfield, Chicopee, Westfield, Holyoke, Amherst, Northampton, West
Springfield, Ludlow, South Hadley, Easthampton, Belchertown,
Wilbraham, Palmer, Ware, Monson, Granby, Southampton, Hadley,
Hardwick and Huntington.

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 4238 7307 4239 7305 4238 7301 4239 7301
      4233 7247 4232 7225 4211 7230 4217 7303
      4225 7300 4231 7300 4231 7303 4233 7306
TIME...MOT...LOC 2053Z 278DEG 27KT 4226 7299 

HAIL...1.25IN
WIND...70MPH
 
$$

Loconto
597 
WWUS51 KBOX 062114
SVSBOX

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

MAC011-013-015-027-062145-
/O.CON.KBOX.SV.W.0048.000000T0000Z-210706T2145Z/
Worcester MA-Hampshire MA-Franklin MA-Hampden MA-
514 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EDT
FOR WESTERN WORCESTER...SOUTHERN HAMPSHIRE...SOUTHEASTERN FRANKLIN
AND CENTRAL HAMPDEN COUNTIES...

At 513 PM EDT, a severe thunderstorm was located over Southampton, or
near Westfield, moving east at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Springfield, Chicopee, Westfield, Holyoke, Amherst, Northampton, West
Springfield, Ludlow, South Hadley, Easthampton, Belchertown,
Wilbraham, Palmer, Ware, Monson, Granby, Southampton, Hadley,
Hardwick and Huntington.

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 4231 7286 4233 7247 4232 7225 4211 7230
      4217 7303 4225 7300 4231 7300 4232 7294
TIME...MOT...LOC 2113Z 278DEG 27KT 4224 7278 

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

Loconto
771 
WWUS51 KBOX 062124
SVSBOX

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

MAC011-013-015-027-062134-
/O.CAN.KBOX.SV.W.0048.000000T0000Z-210706T2145Z/
Worcester MA-Hampshire MA-Franklin MA-Hampden MA-
524 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN WORCESTER...SOUTHERN
HAMPSHIRE...SOUTHEASTERN FRANKLIN AND CENTRAL HAMPDEN 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 and
heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
western and central Massachusetts.

LAT...LON 4231 7286 4233 7247 4232 7225 4211 7230
      4217 7303 4225 7300 4231 7300 4232 7294
TIME...MOT...LOC 2118Z 278DEG 27KT 4223 7267 

$$

Loconto

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, 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, 6:13 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.