Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 29, NWS Boston/Norton, MA

June 30, 2021Franklin County, Middlesex County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 30, 2021, 4:32 PM EDT for Franklin County, Middlesex County, Worcester County, Massachusetts. It was in force for 58 min. 10 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
Jun 30, 2021, 4:32 PM EDT (20:32 UTC)
Expired
Jun 30, 2021, 5:30 PM EDT
In force
58 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Franklin County, MA, Middlesex County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 108 km from the middle of the area, began a volume at 20:33 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
Jun 30, 4:41 PM EDTTSTM WND GST 58Orange Ap, MA
Jun 30, 4:50 PM EDTTSTM WND DMGGill, MATREE DOWN BLOCKING SOUTH CROSS ROAD
Jun 30, 4:50 PM EDTTSTM WND DMGGill, MATREES DOWN ON WIRES ON WEST GILL ROAD
Jun 30, 4:55 PM EDTTSTM WND DMGWarwick, MATREE DOWN BLOCKING ORANGE ROAD
Jun 30, 4:57 PM EDTTSTM WND DMGBernardston, MATREE DOWN ON WIRES HUCKERVILLE ROAD
Jun 30, 5:00 PM EDTTSTM WND DMGAthol, MATREE DOWN ON HOUSE ON JERI DRIVE. TREE DOWN ON METROPLOLITAN COURT
Jun 30, 5:00 PM EDTTSTM WND DMGOrange, MATREE BRANCH DOWN ON WIRES ON WARWICK RD
Jun 30, 5:15 PM EDTTSTM WND DMGAthol, MATRANSFORMER BLOWN, WIRES ACROSS ROAD ON PEQUOIG AVE
Jun 30, 5:21 PM EDTTSTM WND DMGNorthfield, MATREES DOWN ACROSS RANDALL RD
Jun 30, 5:34 PM EDTTSTM WND DMGErving, MATREE AND WIRES DOWN ACROSS RANDALL RD

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
Jun 30, 3:21 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 8.5 hours before the alert went out and 142 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 2021-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 113 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 2021-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 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
113 J/kg
Mixed-layer CIN
-257 J/kg
Mixed-layer LCL
1162 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

936 
WUUS51 KBOX 302032
SVRBOX
MAC011-017-027-302130-
/O.NEW.KBOX.SV.W.0029.210630T2032Z-210630T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
432 PM EDT Wed Jun 30 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northwestern Worcester County in central Massachusetts...
  Northwestern Middlesex County in northeastern Massachusetts...
  Northeastern Franklin County in western Massachusetts...

* Until 530 PM EDT.

* At 432 PM EDT, a severe thunderstorm was located over Gill, or near
  Greenfield, moving east at 25 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...
  Leominster, Fitchburg, Greenfield, Orange, Deerfield, Gardner,
  Athol, Winchendon, Lunenburg, Townsend, Montague, Templeton,
  Sterling, Westminster, Ashburnham, Barre, Hubbardston, Sunderland,
  Princeton and Ashby.

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 4271 7175 4244 7179 4250 7263 4273 7258
TIME...MOT...LOC 2032Z 278DEG 20KT 4262 7252 

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

Frank
1 follow-up statement
204 
WWUS51 KBOX 302042
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
442 PM EDT Wed Jun 30 2021

MAC011-017-027-302130-
/O.CON.KBOX.SV.W.0029.000000T0000Z-210630T2130Z/
Worcester MA-Middlesex MA-Franklin MA-
442 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR NORTHWESTERN WORCESTER...NORTHWESTERN MIDDLESEX AND NORTHEASTERN
FRANKLIN COUNTIES...

At 440 PM EDT, a severe thunderstorm was located over Erving, or 7
miles east of Greenfield, moving east at 25 mph.

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

SOURCE...Radar indicated. At 427 PM in Turners Falls, Trees and 
         wires were reported down near Montague city road near 
         Walnut street. This storm has a history of producing wind 
         damage.

IMPACT...Expect wind damage to trees and power lines. Minor hail 
         damage to vehicles is possible.

Locations impacted include...
Leominster, Fitchburg, Greenfield, Orange, Deerfield, Gardner, Athol,
Winchendon, Lunenburg, Townsend, Montague, Templeton, Sterling,
Westminster, Ashburnham, Barre, Hubbardston, Sunderland, Princeton
and Ashby.

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 4271 7175 4244 7179 4250 7263 4273 7258
TIME...MOT...LOC 2040Z 278DEG 20KT 4261 7245 

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

Frank

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 2:29 AM EDTSmall Craft AdvisoryBOX18 hr
Jun 30, 3:40 PM EDTSpecial Weather StatementBOXHampshire65 min
Jun 30, 3:42 PM EDTSpecial Weather StatementBOXFranklin63 min
Jun 30, 3:48 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire57 min
Jun 30, 4:03 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampshire57 min
Jun 30, 4:39 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester66 min
Jun 30, 4:45 PM EDTTornado WarningBOXFranklin, Worcester26 min
Jun 30, 5:00 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Worcester30 min
Jun 30, 5:13 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Worcester62 min
Jun 30, 5:25 PM EDTSevere Thunderstorm WarningBOXEssex, Middlesex49 min
Jun 30, 5:26 PM EDTSpecial Marine WarningBOX64 min
Jun 30, 5:29 PM EDTSevere Thunderstorm WarningBOXWorcester44 min
Jun 30, 5:43 PM EDTSevere Thunderstorm WarningBOXEssex, Middlesex51 min
Jun 30, 5:54 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Suffolk, Worcester53 min
Jun 30, 5:58 PM EDTSpecial Marine WarningBOX62 min
Jun 30, 6:11 PM EDTSpecial Weather StatementBOXNorfolk49 min
Jun 30, 6:12 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Plymouth, Suffolk, Worcester47 min
Jun 30, 6:22 PM EDTSpecial Marine WarningBOX53 min
Jun 30, 6:31 PM EDTSpecial Marine WarningBOX59 min
Jun 30, 6:45 PM EDTSevere Thunderstorm WarningBOXHampden60 min
Jun 30, 6:57 PM EDTSpecial Marine WarningBOX33 min
Jun 30, 7:15 PM EDTSevere Thunderstorm WarningBOXHampden, Worcester60 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.