Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 43, NWS Boston/Norton, MA

July 6, 2021Franklin County, Hampden County, Hampshire County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 6, 2021, 3:12 PM EDT for Franklin County, Hampden County, Hampshire County, Massachusetts. It was in force for 63 min. 1 report 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, 3:12 PM EDT (19:12 UTC)
Expired
Jul 6, 2021, 4:15 PM EDT
In force
63 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

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

The radar

The Albany radar (KENX), 95 km from the middle of the area, began a volume at 19:15 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, 4:05 PM EDTTSTM WND DMGChesterfield, MATREE DOWN ON WIRES ON STAGE 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, 7.2 hours before the alert went out and 80 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.

369 
WUUS51 KBOX 061912
SVRBOX
MAC011-013-015-062015-
/O.NEW.KBOX.SV.W.0043.210706T1912Z-210706T2015Z/

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

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Hampshire County in western Massachusetts...
  Central Franklin County in western Massachusetts...
  Northwestern Hampden County in western Massachusetts...

* Until 415 PM EDT.

* At 311 PM EDT, a severe thunderstorm was located near Cheshire, or
  8 miles east of Pittsfield, moving east at 20 mph.

  HAZARD...60 mph wind gusts and nickel size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Chicopee, Holyoke, Amherst, Northampton, Deerfield, South Hadley,
  Easthampton, Montague, Granby, Southampton, Hadley, Sunderland,
  Hatfield, Williamsburg, Huntington, Buckland, Conway, Shelburne,
  Leverett and Shutesbury.

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 4239 7305 4238 7301 4252 7297 4256 7298
      4258 7296 4255 7244 4216 7256 4227 7300
      4231 7300 4231 7303 4233 7306 4238 7307
TIME...MOT...LOC 1911Z 278DEG 19KT 4250 7310 

HAIL...0.88IN
WIND...60MPH
 
$$

Loconto
2 follow-up statements
129 
WWUS51 KBOX 061951
SVSBOX

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

MAC011-013-015-062015-
/O.CON.KBOX.SV.W.0043.000000T0000Z-210706T2015Z/
Hampshire MA-Franklin MA-Hampden MA-
351 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR HAMPSHIRE...CENTRAL FRANKLIN AND NORTHWESTERN HAMPDEN COUNTIES...

At 350 PM EDT, a severe thunderstorm was located over Goshen, or 12
miles northwest of Northampton, moving east at 20 mph.

HAZARD...60 mph wind gusts and nickel size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Chicopee, Holyoke, Amherst, Northampton, Deerfield, South Hadley,
Easthampton, Montague, Granby, Southampton, Hadley, Sunderland,
Hatfield, Williamsburg, Huntington, Buckland, Conway, Shelburne,
Leverett and Shutesbury.

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 4239 7305 4238 7301 4252 7297 4256 7298
      4258 7296 4255 7244 4216 7256 4227 7300
      4231 7300 4231 7303 4233 7306 4238 7307
TIME...MOT...LOC 1950Z 278DEG 19KT 4247 7282 

HAIL...0.88IN
WIND...60MPH
 
$$

Loconto
765 
WWUS51 KBOX 062014
SVSBOX

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

MAC011-013-015-062024-
/O.EXP.KBOX.SV.W.0043.000000T0000Z-210706T2015Z/
Hampshire MA-Franklin MA-Hampden MA-
414 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR HAMPSHIRE...CENTRAL FRANKLIN
AND NORTHWESTERN HAMPDEN COUNTIES WILL EXPIRE AT 415 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small
hail, gusty winds and heavy rain are still possible with this
thunderstorm.

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

LAT...LON 4239 7305 4238 7301 4252 7297 4256 7298
      4258 7296 4255 7244 4216 7256 4227 7300
      4231 7300 4231 7303 4233 7306 4238 7307
TIME...MOT...LOC 2014Z 278DEG 19KT 4246 7271 

$$

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, 3:36 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, 6:13 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.