Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 4, NWS Boston/Norton, MA

May 26, 20214 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at May 26, 2021, 6:39 PM EDT for 4 counties in Massachusetts. It was in force for 66 min. 2 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
May 26, 2021, 6:39 PM EDT (22:39 UTC)
Expired
May 26, 2021, 7:45 PM EDT
In force
66 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

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

The radar

The Boston radar (KBOX), 82 km from the middle of the area, began a volume at 22:40 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
May 26, 6:39 PM EDTTSTM WND DMGPelham, MATREE DOWN ON AMHERST ROAD
May 26, 7:20 PM EDTTSTM WND DMGSpringfield, MAMULTIPLE TREES DOWN ON NORTH BRANCH PARKWAY

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
May 26, 3:56 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 10.7 hours before the alert went out and 155 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.

322 
WUUS51 KBOX 262239
SVRBOX
MAC011-013-015-027-262345-
/O.NEW.KBOX.SV.W.0004.210526T2239Z-210526T2345Z/

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

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Central Worcester County in central Massachusetts...
  Southeastern Hampshire County in western Massachusetts...
  Southeastern Franklin County in western Massachusetts...
  Central Hampden County in western Massachusetts...

* Until 745 PM EDT.

* At 638 PM EDT, severe thunderstorms were located along a line
  extending from near Templeton to near South Hadley, moving east at
  30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Worcester, Springfield, Chicopee, Westfield, Leominster, Holyoke,
  Amherst, Shrewsbury, Northampton, West Springfield, Ludlow, South
  Hadley, Holden, Southbridge, Auburn, Easthampton, Belchertown,
  Wilbraham, Northborough and Oxford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4248 7156 4231 7166 4205 7198 4216 7293
      4251 7230
TIME...MOT...LOC 2238Z 274DEG 25KT 4252 7209 4223 7255 

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

BL
2 follow-up statements
523 
WWUS51 KBOX 262250
SVSBOX

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

MAC011-013-015-027-262345-
/O.CON.KBOX.SV.W.0004.000000T0000Z-210526T2345Z/
Worcester MA-Hampshire MA-Franklin MA-Hampden MA-
650 PM EDT Wed May 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR CENTRAL WORCESTER...SOUTHEASTERN HAMPSHIRE...SOUTHEASTERN
FRANKLIN AND CENTRAL HAMPDEN COUNTIES...

At 648 PM EDT, severe thunderstorms were located along a line
extending from Hubbardston to near Granby, moving east at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Trained weather spotters. At 640 PM EDT trees down in 
         Pelham, MA on Amherst and Jones Roads.

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

Locations impacted include...
Worcester, Springfield, Chicopee, Westfield, Leominster, Holyoke,
Amherst, Shrewsbury, Northampton, West Springfield, Ludlow, South
Hadley, Holden, Southbridge, Auburn, Easthampton, Belchertown,
Wilbraham, Northborough and Oxford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4248 7156 4231 7166 4205 7198 4216 7293
      4251 7230
TIME...MOT...LOC 2248Z 274DEG 25KT 4252 7200 4223 7246 

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

FN
377 
WWUS51 KBOX 262326
SVSBOX

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

MAC011-262335-
/O.CAN.KBOX.SV.W.0004.000000T0000Z-210526T2345Z/
Franklin MA-
726 PM EDT Wed May 26 2021

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

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

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

LAT...LON 4216 7293 4219 7273 4231 7235 4250 7197
      4248 7156 4231 7166 4205 7198
TIME...MOT...LOC 2325Z 254DEG 31KT 4248 7167 4211 7234 

$$

MAC013-015-027-262345-
/O.CON.KBOX.SV.W.0004.000000T0000Z-210526T2345Z/
Worcester MA-Hampshire MA-Hampden MA-
726 PM EDT Wed May 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR CENTRAL WORCESTER...SOUTHEASTERN HAMPSHIRE AND CENTRAL HAMPDEN
COUNTIES...

At 725 PM EDT, severe thunderstorms were located along a line
extending from Lancaster to Monson, moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Trained weather spotters.

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

Locations impacted include...
Worcester, Springfield, Chicopee, Westfield, Leominster, Holyoke,
Shrewsbury, West Springfield, Ludlow, South Hadley, Holden,
Southbridge, Auburn, Belchertown, Wilbraham, Northborough, Oxford,
Clinton, Millbury and Charlton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4216 7293 4219 7273 4231 7235 4250 7197
      4248 7156 4231 7166 4205 7198
TIME...MOT...LOC 2325Z 254DEG 31KT 4248 7167 4211 7234 

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, 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, 7:45 PM EDTSevere Thunderstorm WarningBOXHampden, Hampshire, 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.