Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 58, NWS Boston/Norton, MA

July 7, 2021Hampden County, Hampshire County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 7, 2021, 5:21 PM EDT for Hampden County, Hampshire County, Worcester County, Massachusetts. It was in force for 54 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 7, 2021, 5:21 PM EDT (21:21 UTC)
Expired
Jul 7, 2021, 6:15 PM EDT
In force
54 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

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

The radar

The Boston radar (KBOX), 87 km from the middle of the area, began a volume at 21:20 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 7, 5:50 PM EDTTSTM WND DMGWest Brookfield, MATREES AND WIRES ON LONG HILL 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 7, 2:41 PM EDTSevere Thunderstorm WatchSPC10 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 9.4 hours before the alert went out and 149 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 2021-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 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 2021-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 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
18 J/kg
Mixed-layer CIN
-132 J/kg
Mixed-layer LCL
923 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

248 
WUUS51 KBOX 072121
SVRBOX
MAC013-015-027-072215-
/O.NEW.KBOX.SV.W.0058.210707T2121Z-210707T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
521 PM EDT Wed Jul 7 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Southwestern Worcester County in central Massachusetts...
  East central Hampshire County in western Massachusetts...
  East central Hampden County in western Massachusetts...

* Until 615 PM EDT.

* At 521 PM EDT, a severe thunderstorm was located over West
  Brookfield, or 18 miles southeast of Amherst, moving east at 15
  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...
  Worcester, Holden, Auburn, Oxford, Charlton, Palmer, Spencer,
  Leicester, Ware, Sturbridge, Rutland, Barre, Warren, Paxton, North
  Brookfield, West Brookfield, Brimfield, Princeton, Brookfield and
  Hardwick.

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 4216 7229 4237 7228 4244 7187 4210 7184
TIME...MOT...LOC 2121Z 274DEG 12KT 4225 7219 

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

Loconto
3 follow-up statements
274 
WWUS51 KBOX 072138
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
538 PM EDT Wed Jul 7 2021

MAC013-015-027-072215-
/O.CON.KBOX.SV.W.0058.000000T0000Z-210707T2215Z/
Worcester MA-Hampshire MA-Hampden MA-
538 PM EDT Wed Jul 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR SOUTHWESTERN WORCESTER...EASTERN HAMPSHIRE AND EAST CENTRAL
HAMPDEN COUNTIES...

At 538 PM EDT, a severe thunderstorm was located over West
Brookfield, or 15 miles west of Worcester, moving east at 15 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...
Worcester, Holden, Auburn, Oxford, Charlton, Palmer, Spencer,
Leicester, Ware, Sturbridge, Rutland, Barre, Warren, Paxton, North
Brookfield, West Brookfield, Brimfield, Princeton, Brookfield and
Hardwick.

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 4216 7229 4238 7222 4244 7187 4210 7184
TIME...MOT...LOC 2138Z 274DEG 12KT 4225 7211 

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

Loconto
477 
WWUS51 KBOX 072149
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
549 PM EDT Wed Jul 7 2021

MAC013-015-027-072215-
/O.CON.KBOX.SV.W.0058.000000T0000Z-210707T2215Z/
Worcester MA-Hampshire MA-Hampden MA-
549 PM EDT Wed Jul 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR SOUTHWESTERN WORCESTER...EASTERN HAMPSHIRE AND EAST CENTRAL
HAMPDEN COUNTIES...

At 548 PM EDT, a severe thunderstorm was located over North
Brookfield, or 13 miles west of Worcester, moving east at 15 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Worcester, Holden, Auburn, Oxford, Charlton, Palmer, Spencer,
Leicester, Ware, Sturbridge, Rutland, Warren, Paxton, North
Brookfield, West Brookfield, Brimfield, Princeton, Brookfield, East
Brookfield and Oakham.

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 4216 7229 4233 7217 4244 7187 4210 7184
TIME...MOT...LOC 2148Z 274DEG 12KT 4225 7206 

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

Loconto
834 
WWUS51 KBOX 072213
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
613 PM EDT Wed Jul 7 2021

MAC013-015-027-072223-
/O.EXP.KBOX.SV.W.0058.000000T0000Z-210707T2215Z/
Worcester MA-Hampshire MA-Hampden MA-
613 PM EDT Wed Jul 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WORCESTER...
EASTERN HAMPSHIRE AND EAST CENTRAL HAMPDEN COUNTIES WILL EXPIRE AT
615 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
western and central Massachusetts.

LAT...LON 4216 7229 4233 7217 4244 7187 4210 7184
TIME...MOT...LOC 2213Z 274DEG 12KT 4225 7198 

$$

Loconto

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 4:00 PM EDTSevere Thunderstorm WarningBOXHampden, Hampshire60 min
Jul 7, 4:01 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampshire59 min
Jul 7, 4:05 PM EDTSpecial Weather StatementBOXEssex40 min
Jul 7, 4:33 PM EDTSevere Thunderstorm WarningBOXEssex, Middlesex57 min
Jul 7, 5:02 PM EDTSpecial Weather StatementBOXWorcester43 min
Jul 7, 5:05 PM EDTSpecial Marine WarningBOX25 min
Jul 7, 5:10 PM EDTTropical Storm WatchBOXBarnstable, Bristol, Dukes, Nantucket, Plymouth13 hr
Jul 7, 5:24 PM EDTSpecial Marine WarningBOX66 min
Jul 7, 5:30 PM EDTSevere Thunderstorm WarningBOXHampden, Worcester60 min
Jul 7, 6:01 PM EDTSpecial Weather StatementBOXWorcester44 min
Jul 7, 6:17 PM EDTSevere Thunderstorm WarningBOXBristol, Middlesex, Norfolk, Worcester58 min
Jul 7, 6:18 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Worcester36 min
Jul 7, 6:22 PM EDTSpecial Marine WarningBOX53 min
Jul 7, 6:59 PM EDTSevere Thunderstorm WarningBOXBristol, Middlesex, Norfolk, Plymouth, Suffolk61 min
Jul 7, 7:18 PM EDTSpecial Marine WarningBOX57 min
Jul 7, 7:47 PM EDTSevere Thunderstorm WarningBOXNorfolk, Plymouth25 min
Jul 7, 7:51 PM EDTSpecial Marine WarningBOX54 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.