Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 95, NWS Boston/Norton, MA

July 27, 2021Providence County, Rhode Island; Hampden County, Worcester County, Massachusetts; Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 27, 2021, 7:01 PM EDT for Providence County, Rhode Island; Hampden County, Worcester County, Massachusetts; Northeastern Connecticut Planning Region, Connecticut. It was in force for 44 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 27, 2021, 7:01 PM EDT (23:01 UTC)
Expired
Jul 27, 2021, 7:45 PM EDT
In force
44 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Northeastern Connecticut Planning Region, CT, Hampden County, MA, Worcester County, MA, Providence County, RI

The radar

The Boston radar (KBOX), 73 km from the middle of the area, began a volume at 23:05 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 27, 7:25 PM EDTTSTM WND DMG4 Nne Glocester, RITREE DOWN ON A CAR NEAR 1720 VICTORY HIGHWAY IN BURRILLVILLE. RELAYED BY AMATEUR RADIO.

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 27, 2:47 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 11.0 hours before the alert went out and 144 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, Brookhaven, NY at 12:00Z on 2021-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Brookhaven, NY at 12:00Z on 2021-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2105 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

343 
WUUS51 KBOX 272301
SVRBOX
CTC013-015-MAC013-027-RIC007-280000-
/O.NEW.KBOX.SV.W.0095.210727T2301Z-210728T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
701 PM EDT Tue Jul 27 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northern Windham County in northern Connecticut...
  Northeastern Tolland County in northern Connecticut...
  Southeastern Worcester County in central Massachusetts...
  Southeastern Hampden County in western Massachusetts...
  Northwestern Providence County in Rhode Island...

* Until 800 PM EDT.

* At 701 PM EDT, a severe thunderstorm was located over Southbridge,
  or 18 miles southwest of Worcester, moving southeast at 20 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...
  Killingly, Webster, Southbridge, Burrillville, Northbridge, Oxford,
  Uxbridge, Charlton, Stafford, North Smithfield, Dudley, Glocester,
  Putnam, Thompson, Sturbridge, Blackstone, Sutton, Douglas, Brooklyn
  and Woodstock.

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 4198 7236 4218 7207 4209 7151 4177 7180
TIME...MOT...LOC 2301Z 297DEG 16KT 4207 7204 

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

Loconto/Gaucher
2 follow-up statements
677 
WWUS51 KBOX 272331
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
731 PM EDT Tue Jul 27 2021

MAC013-272340-
/O.CAN.KBOX.SV.W.0095.000000T0000Z-210728T0000Z/
Hampden MA-
731 PM EDT Tue Jul 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HAMPDEN COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
northern Connecticut...western and central Massachusetts...and Rhode
Island.

LAT...LON 4215 7190 4209 7151 4177 7180 4196 7229
TIME...MOT...LOC 2330Z 297DEG 16KT 4201 7188 

$$

CTC013-015-MAC027-RIC007-280000-
/O.CON.KBOX.SV.W.0095.000000T0000Z-210728T0000Z/
Windham CT-Tolland CT-Worcester MA-Providence RI-
731 PM EDT Tue Jul 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR NORTHERN WINDHAM...NORTHEASTERN TOLLAND...SOUTHEASTERN WORCESTER
AND NORTHWESTERN PROVIDENCE COUNTIES...

At 730 PM EDT, a severe thunderstorm was located over Thompson, or 18
miles south of Worcester, moving southeast at 20 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Killingly, Webster, Southbridge, Burrillville, Northbridge, Oxford,
Uxbridge, Charlton, Stafford, North Smithfield, Dudley, Glocester,
Putnam, Thompson, Sturbridge, Blackstone, Sutton, Douglas, Brooklyn
and Woodstock.

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 4215 7190 4209 7151 4177 7180 4196 7229
TIME...MOT...LOC 2330Z 297DEG 16KT 4201 7188 

HAIL...0.75IN
WIND...60MPH
 
$$

Loconto/Gaucher
712 
WWUS51 KBOX 272345
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
745 PM EDT Tue Jul 27 2021

CTC013-015-MAC027-RIC007-272355-
/O.CAN.KBOX.SV.W.0095.000000T0000Z-210728T0000Z/
Windham CT-Tolland CT-Worcester MA-Providence RI-
745 PM EDT Tue Jul 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN WINDHAM...
NORTHEASTERN TOLLAND...SOUTHEASTERN WORCESTER AND NORTHWESTERN
PROVIDENCE 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 are
still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
northern Connecticut...and Rhode Island.

LAT...LON 4215 7190 4209 7151 4177 7180 4196 7229
TIME...MOT...LOC 2343Z 297DEG 16KT 4198 7180 

$$

Gaucher/Loconto

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 7:21 PM EDTSpecial Weather StatementBOXKent39 min
Jul 27, 7:26 PM EDTSevere Thunderstorm WarningBOXProvidence64 min
Jul 27, 4:48 PM EDTSpecial Weather StatementBOXFranklin27 min
Jul 27, 4:59 PM EDTSpecial Weather StatementBOXHampshire31 min
Jul 27, 5:04 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire56 min
Jul 27, 5:15 PM EDTSpecial Weather StatementBOXFranklin30 min
Jul 27, 5:34 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire56 min
Jul 27, 6:01 PM EDTSpecial Weather StatementBOXWorcester29 min
Jul 27, 6:33 PM EDTSevere Thunderstorm WarningBOXEssex, Middlesex, Norfolk, Plymouth, Suffolk, Worcester57 min
Jul 27, 6:50 PM EDTSpecial Weather StatementBOXEssex25 min
Jul 27, 6:52 PM EDTSpecial Marine WarningBOX53 min
Jul 27, 7:11 PM EDTSpecial Marine WarningBOX94 min
Jul 27, 7:39 PM EDTSpecial Marine WarningBOX66 min
Jul 27, 6:27 PM EDTSpecial Weather StatementBOX48 min
Jul 27, 6:53 PM EDTSpecial Weather StatementBOX37 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2021Severe Thunderstorm Warnings in Connecticut, 2021Severe Thunderstorm Warnings in Rhode Island, 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.