Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 1, NWS Boston/Norton, MA

April 21, 2021Capitol Planning Region, Connecticut; Hampden County, Hampshire County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Apr 21, 2021, 3:17 PM EDT for Capitol Planning Region, Connecticut; Hampden County, Hampshire County, Massachusetts. It was in force for 58 min. 24 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: Apr 21, 2021, 3:17 PM EDT (19:17 UTC)
Expired: Apr 21, 2021, 4:15 PM EDT
In force: 58 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Capitol Planning Region, CT, Hampden County, MA, Hampshire County, MA

The radar

The Albany radar (KENX), 119 km from the middle of the area, began a volume at 19:17 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

Time	Report	Where	Remark
Apr 21, 3:45 PM EDT	TSTM WND DMG	Simsbury, CT	TREE DOWN ON HOUSE AT 8 THE BUTTERCHURN.
Apr 21, 3:45 PM EDT	TSTM WND DMG	Simsbury, CT	TREE DOWN ON HOUSE ON BUTTERTURN RD.
Apr 21, 3:46 PM EDT	HAIL 0.75	Granby, MA
Apr 21, 3:50 PM EDT	TSTM WND DMG	Granby, CT	TREE DOWN BLOCKING NOTCH ROAD.
Apr 21, 3:50 PM EDT	TSTM WND DMG	Holyoke, MA	TREE AND POWER LINES DOWN ON SILVER STREET.
Apr 21, 3:56 PM EDT	HAIL 0.75	1 Ne Westfield, MA	REPORT FROM MPING: DIME (0.75 IN.).
Apr 21, 3:58 PM EDT	TSTM WND DMG	Russell, MA	TWO TREES DOWN ON GENERAL KNOX ROAD.
Apr 21, 3:58 PM EDT	TSTM WND DMG	Southwick, MA	TREES AND TRANSFORM DOWN ON SLEEP PASTURE ROAD. UTILITY POLES DOWN ON SOUTH LONGYARD RD.
Apr 21, 4:01 PM EDT	TSTM WND DMG	Agawam, MA	POLE AND WIRES DOWN ON A CAR ON ROUTE 159 AT SOUTHWICK LINE.
Apr 21, 4:01 PM EDT	TSTM WND DMG	Agawam, MA	POLE AND WIRES DOWN ON CAR ON RTE 159.
Apr 21, 4:03 PM EDT	TSTM WND DMG	3 Nw Suffield, CT	REPORT FROM MPING: 3-INCH TREE LIMBS BROKEN; POWER POLES BROKEN.
Apr 21, 4:05 PM EDT	TSTM WND DMG	Enfield, CT	TREE DOWN ON WIRES ON GEORGE WASHINGTON RD.
Apr 21, 4:05 PM EDT	TSTM WND DMG	Enfield, CT	TREE DOWN ON WIRES ON GEORGE WASHINGTON ROAD.
Apr 21, 4:05 PM EDT	TSTM WND DMG	Holyoke, MA	TREE AND UTILITY POLE DOWN ON A HOUSE ON MAYER DRIVE.
Apr 21, 4:10 PM EDT	TSTM WND DMG	Chicopee, MA	TREE DOWN BLOCKING CHICOPEE STREET AT CARPENTER BLVD.
Apr 21, 4:10 PM EDT	TSTM WND DMG	Chicopee, MA	TREE DOWN ON CARS ON CHICOPEE ROAD.
Apr 21, 4:10 PM EDT	TSTM WND DMG	Chicopee, MA	TREE DOWN ON HOUSE AT PENDLETON AVE AND DESLORIES AVE. EXTENSIVE DAMAGE TO HOUSE. TREES DOWN ON GARLAND AVENUE AND GRANBY ROAD.
Apr 21, 4:10 PM EDT	TSTM WND DMG	Chicopee, MA	TREES AND WIRES DOWN ON BEVERLY STREET AND DESLORIES AVENUE, TREE AND WIRES AND UTILITY POLE DOWN ON BILLINGS STREET.
Apr 21, 4:10 PM EDT	TSTM WND DMG	Chicopee, MA	WOODBRIDGE ROAD, HONEYSUCKLE DRIVE, APPLEWOOD DRIVE, MEADOWLARK DRIVE AND LYNWOOD DRIVE ALL IN DOVER CONDOS COMPLEX HAD 15 LARGE TREES BLOWN DOWN. THREE UNITS HAD TREES THROUGH THE ROOF WITH ONE UNIT HAVING A TREE THROUGH THE ROOF OF A BEDROOM JUST MISSINTG A
Apr 21, 4:12 PM EDT	TSTM WND DMG	Southwick, MA	SEVERAL UTILITY POLES SNAPPED, TREES AND WIRES DOWN ON SOUTH LONGYARD ROAD AND SLEEP PASTURE ROAD.
Apr 21, 4:12 PM EDT	TSTM WND DMG	Southwick, MA	TREE AND TRANSFORMER DOWN ON SLEEP PASTURE ROAD.
Apr 21, 4:15 PM EDT	TSTM WND DMG	Ludlow, MA	TREES AND WIRES DOWN AT WESTOVER GOLF COURSE. TREE DOWN ON WAVERLY CIRCLE.
Apr 21, 4:21 PM EDT	TSTM WND DMG	Huntington, MA	TREE DOWN IN YARDS ON GOSS HILL ROAD BY STAGE ROAD.
Apr 21, 4:23 PM EDT	TSTM WND DMG	Russell, MA	TWO TREES DOWN ACROSS GENERAL KNOX 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.

Issued	Product	Office	Lasted
Apr 21, 12:28 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 7.3 hours before the alert went out and 110 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 814 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 298 m²/s²
0-3 km storm-relative helicity: 352 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

404 
WUUS51 KBOX 211917
SVRBOX
CTC003-MAC013-015-212015-
/O.NEW.KBOX.SV.W.0001.210421T1917Z-210421T2015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
317 PM EDT Wed Apr 21 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northwestern Hartford County in northern Connecticut...
  South central Hampshire County in western Massachusetts...
  Hampden County in western Massachusetts...

* Until 415 PM EDT.

* At 317 PM EDT, severe thunderstorms were located along a line
  extending from near Canaan to near Winsted to Torrington, moving
  northeast at 50 mph.

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

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Burlington around 325 PM EDT.
  Canton, Hartland and Tolland around 330 PM EDT.
  Granby around 335 PM EDT.
  Simsbury, Granville and Blandford around 340 PM EDT.
  Windsor, Windsor Locks, Southwick, East Granby and Russell around 
  345 PM EDT.
  Westfield, Agawam, West Springfield, Suffield and Montgomery 
  around 350 PM EDT.
  Holyoke, Longmeadow, Southampton, Huntington and Westhampton 
  around 355 PM EDT.
  Springfield, Chicopee, Enfield, Easthampton and Somers around 400 
  PM EDT.

LAT...LON 4215 7307 4215 7303 4221 7302 4239 7254
      4225 7238 4207 7233 4203 7243 4204 7251
      4200 7250 4178 7301 4180 7301 4182 7294
      4188 7295 4190 7291 4197 7289 4197 7303
      4204 7301 4204 7306
TIME...MOT...LOC 1917Z 240DEG 43KT 4204 7328 4193 7312 4181 7311 

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

JWD

3 follow-up statements

460 
WWUS51 KBOX 211943
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
343 PM EDT Wed Apr 21 2021

CTC003-MAC013-015-212015-
/O.CON.KBOX.SV.W.0001.000000T0000Z-210421T2015Z/
Hartford CT-Hampshire MA-Hampden MA-
343 PM EDT Wed Apr 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR NORTHWESTERN HARTFORD...SOUTH CENTRAL HAMPSHIRE AND HAMPDEN
COUNTIES...

At 342 PM EDT, severe thunderstorms were located along a line
extending from near Blandford to near Southwick to near East Granby,
moving northeast at 40 mph.

The strongest storm along the line was near Granby.

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

SOURCE...Radar indicated.

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

These severe storms will be near...
  Southwick around 350 PM EDT.
  Windsor, Agawam, Suffield and Windsor Locks around 355 PM EDT.
  Westfield, West Springfield, Longmeadow and Montgomery around 400 
  PM EDT.
  Southampton and Westhampton around 405 PM EDT.
  Chicopee, Enfield and Somers around 410 PM EDT.
  Springfield, Holyoke, Northampton, Easthampton and East Longmeadow 
  around 415 PM EDT.
  Ludlow, South Hadley, Wilbraham and Hampden around 420 PM EDT.
  Monson and Hatfield around 425 PM EDT.

LAT...LON 4213 7304 4215 7301 4221 7302 4239 7254
      4225 7238 4207 7233 4203 7243 4204 7251
      4200 7250 4185 7285 4187 7289 4187 7290
      4188 7289 4190 7291 4197 7289 4198 7296
      4204 7301 4206 7303
TIME...MOT...LOC 1942Z 246DEG 33KT 4215 7298 4203 7283 4193 7279 

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

JWD

359 
WWUS51 KBOX 211959
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
359 PM EDT Wed Apr 21 2021

CTC003-MAC013-015-212015-
/O.CON.KBOX.SV.W.0001.000000T0000Z-210421T2015Z/
Hartford CT-Hampshire MA-Hampden MA-
359 PM EDT Wed Apr 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR NORTH CENTRAL HARTFORD...SOUTH CENTRAL HAMPSHIRE AND EASTERN
HAMPDEN COUNTIES...

At 358 PM EDT, severe thunderstorms were located along a line
extending from Southampton to near West Springfield to Longmeadow,
moving northeast at 45 mph.

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

SOURCE...Radar indicated.

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

These severe storms will be near...
  Ludlow, South Hadley, Wilbraham and Hampden around 410 PM EDT.
  Monson and Granby around 415 PM EDT.
  
LAT...LON 4236 7254 4223 7239 4207 7233 4203 7243
      4204 7251 4200 7250 4192 7268 4193 7270
      4195 7270 4198 7273 4205 7282 4220 7287
TIME...MOT...LOC 1958Z 240DEG 43KT 4225 7275 4213 7260 4203 7256 

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

JWD

745 
WWUS51 KBOX 212009
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
409 PM EDT Wed Apr 21 2021

CTC003-MAC013-015-212017-
/O.EXP.KBOX.SV.W.0001.000000T0000Z-210421T2015Z/
Hartford CT-Hampshire MA-Hampden MA-
409 PM EDT Wed Apr 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL HARTFORD...SOUTH
CENTRAL HAMPSHIRE AND EASTERN HAMPDEN COUNTIES WILL EXPIRE AT 415 PM
EDT...

The storms which prompted the warning have weakened below severe 
limits, so the warning will be allowed to expire at 415 PM.

However, strong winds gusting to 40 MPH may cause minor damage such 
as a downed tree limbs. Pea sized hail is also possible.

A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
northern Connecticut...and western Massachusetts.

&&

LAT...LON 4236 7254 4223 7239 4207 7233 4203 7243
      4204 7251 4200 7250 4192 7268 4193 7270
      4195 7270 4198 7273 4205 7282 4220 7287
TIME...MOT...LOC 2007Z 240DEG 43KT 4225 7275 4213 7260 4203 7256 

$$

JWD

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 21, 2:15 PM EDT	Special Weather Statement	BOX		90 min
Apr 21, 4:13 PM EDT	Freeze Warning	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	14 hr
Apr 21, 3:25 PM EDT	Special Weather Statement	BOX	Franklin	50 min
Apr 21, 4:11 PM EDT	Special Weather Statement	BOX	Worcester	49 min
Apr 21, 4:13 PM EDT	Freeze Watch	BOX	Bristol, Norfolk, Plymouth	24 hr
Apr 21, 4:42 PM EDT	Special Weather Statement	BOX	Worcester	48 min
Apr 21, 5:26 PM EDT	Special Weather Statement	BOX	Essex, Norfolk, Suffolk	49 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2021 Severe Thunderstorm Warnings in Connecticut, 2021 Every 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.