Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 7, NWS Boston/Norton, MA

May 26, 2021Hampden County, Hampshire County, Worcester County, Massachusetts; Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this severe thunderstorm warning at May 26, 2021, 7:45 PM EDT for Hampden County, Hampshire County, Worcester County, Massachusetts; Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut. It was in force for 60 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 26, 2021, 7:45 PM EDT (23:45 UTC)
Expired
May 26, 2021, 8:45 PM EDT
In force
60 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT, Hampden County, MA, Hampshire County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 116 km from the middle of the area, began a volume at 23:45 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 26, 3:56 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 11.8 hours before the alert went out and 129 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 2021-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 2021-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 149 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
6 J/kg
Mixed-layer CIN
-291 J/kg
Mixed-layer LCL
1196 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

908 
WUUS51 KBOX 262345
SVRBOX
CTC003-013-015-MAC013-015-027-270045-
/O.NEW.KBOX.SV.W.0007.210526T2345Z-210527T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
745 PM EDT Wed May 26 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northern Windham County in northern Connecticut...
  Northern Tolland County in northern Connecticut...
  Northern Hartford County in northern Connecticut...
  Southern Worcester County in central Massachusetts...
  Southeastern Hampshire County in western Massachusetts...
  Southeastern Hampden County in western Massachusetts...

* Until 845 PM EDT.

* At 745 PM EDT, severe thunderstorms were located along a line 
  extending from Brookfield to Canton, 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, Enfield, Westfield, Windsor, Agawam, West Springfield,
  Simsbury, Ludlow, Bloomfield, Webster, Southbridge, Auburn,
  Longmeadow, Suffield, East Longmeadow, Northbridge, Ellington,
  Tolland, Wilbraham and Oxford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4197 7302 4209 7273 4225 7217 4213 7155
      4188 7206 4190 7291 4197 7289
TIME...MOT...LOC 2344Z 286DEG 27KT 4217 7214 4186 7291 

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

BL
2 follow-up statements
000 
WWUS51 KBOX 270008
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
808 PM EDT Wed May 26 2021

MAC015-270016-
/O.CAN.KBOX.SV.W.0007.000000T0000Z-210527T0045Z/
Hampshire MA-
808 PM EDT Wed May 26 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HAMPSHIRE COUNTY
IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 4209 7247 4224 7210 4213 7155 4188 7206
      4190 7291 4198 7272
TIME...MOT...LOC 0006Z 270DEG 27KT 4213 7193 4182 7270 

$$

CTC003-013-015-MAC013-027-270045-
/O.CON.KBOX.SV.W.0007.000000T0000Z-210527T0045Z/
Windham CT-Tolland CT-Hartford CT-Worcester MA-Hampden MA-
808 PM EDT Wed May 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR NORTHERN WINDHAM...NORTHERN TOLLAND...NORTHERN HARTFORD...
SOUTHERN WORCESTER AND SOUTHEASTERN HAMPDEN COUNTIES...

At 806 PM EDT, severe thunderstorms were located along a line
extending from near Charlton to near Bloomfield, moving east at 30
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Enfield, Windsor, Simsbury, Bloomfield, Webster, Southbridge, Auburn,
Longmeadow, Suffield, East Longmeadow, Northbridge, Ellington,
Tolland, Wilbraham, Oxford, Uxbridge, Millbury, Charlton, Windsor
Locks and Palmer.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4209 7247 4224 7210 4213 7155 4188 7206
      4190 7291 4198 7272
TIME...MOT...LOC 0006Z 270DEG 27KT 4213 7193 4182 7270 

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

BL
185 
WWUS51 KBOX 270031
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
831 PM EDT Wed May 26 2021

MAC013-270040-
/O.CAN.KBOX.SV.W.0007.000000T0000Z-210527T0045Z/
Hampden MA-
831 PM EDT Wed May 26 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HAMPDEN COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 4203 7238 4202 7177 4188 7206 4189 7270
      4195 7254
TIME...MOT...LOC 0030Z 282DEG 16KT 4216 7197 4178 7249 

$$

CTC003-013-015-MAC027-270045-
/O.CON.KBOX.SV.W.0007.000000T0000Z-210527T0045Z/
Windham CT-Tolland CT-Hartford CT-Worcester MA-
831 PM EDT Wed May 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR NORTHERN WINDHAM...NORTHERN TOLLAND...NORTHEASTERN HARTFORD AND
SOUTHERN WORCESTER COUNTIES...

At 831 PM EDT, severe thunderstorms were located along a line 
extending from Charlton to Manchester, moving east at 20 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Enfield, Windsor, Ellington, Tolland, Windsor Locks, Stafford,
Somers, East Windsor, Thompson, Douglas, Woodstock, Willington,
Ashford, Pomfret, Eastford and Union.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4203 7238 4202 7177 4188 7206 4189 7270
      4195 7254
TIME...MOT...LOC 0030Z 282DEG 16KT 4216 7197 4178 7249 

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

BL

The office that day

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

IssuedProductOfficeCountiesLasted
May 25, 10:05 PM EDTSmall Craft AdvisoryBOX12 hr
May 26, 9:51 AM EDTSmall Craft AdvisoryBOX21 hr
May 26, 5:03 PM EDTSpecial Weather StatementBOXFranklin27 min
May 26, 5:30 PM EDTSpecial Weather StatementBOXFranklin45 min
May 26, 5:47 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampshire, Worcester58 min
May 26, 6:13 PM EDTSevere Thunderstorm WarningBOXFranklin, Middlesex, Worcester62 min
May 26, 6:39 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester66 min
May 26, 7:05 PM EDTSevere Thunderstorm WarningBOXHampden55 min
May 26, 7:15 PM EDTSpecial Weather StatementBOXEssex, Middlesex45 min
May 26, 7:21 PM EDTSpecial Marine WarningBOX54 min
May 26, 7:40 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region65 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2021Severe Thunderstorm Warnings in Connecticut, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.