Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 98, NWS Boston/Norton, MA

August 12, 2021Hampden County, Hampshire County, Worcester County, Massachusetts; Capitol Planning Region, Connecticut

NWS Boston/Norton, MA issued this severe thunderstorm warning at Aug 12, 2021, 5:35 PM EDT for Hampden County, Hampshire County, Worcester County, Massachusetts; Capitol Planning Region, Connecticut. It was in force for 55 min. 5 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: Aug 12, 2021, 5:35 PM EDT (21:35 UTC)
Expired: Aug 12, 2021, 6:30 PM EDT
In force: 55 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, Worcester County, MA

The radar

The Albany radar (KENX), 121 km from the middle of the area, began a volume at 21:38 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
Aug 12, 5:37 PM EDT	TSTM WND GST 58	Westover Afb, MA
Aug 12, 5:44 PM EDT	TSTM WND DMG	Agawam, MA	TREE AND WIRES DOWN ON HIGH STREET. TREE DOWN ON LINE STREET
Aug 12, 5:50 PM EDT	TSTM WND DMG	Chicopee, MA	TREE DOWN ON HOME ON CRESCENT DRIVE
Aug 12, 6:00 PM EDT	TSTM WND DMG	Enfield, CT	6 POWER POLES DOWN ON SOUTH STREET
Aug 12, 6:20 PM EDT	TSTM WND DMG	Hartland, CT	TREE AND WIRES DOWN ON SOUTH ROAD

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 9.6 hours before the alert went out and 114 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: 58 J/kg
Mixed-layer CIN: -212 J/kg
Mixed-layer LCL: 1178 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 56 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

922 
WUUS51 KBOX 122135
SVRBOX
CTC003-013-MAC013-015-027-122230-
/O.NEW.KBOX.SV.W.0098.210812T2135Z-210812T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
535 PM EDT Thu Aug 12 2021

The National Weather Service in Boston/Norton has issued a

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

* Until 630 PM EDT.

* At 534 PM EDT, severe thunderstorms were located along a line
  extending from Holyoke to near Winsted, moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Springfield, Hartford, West Hartford, Manchester, Chicopee, East
  Hartford, Enfield, Westfield, Holyoke, Glastonbury, Vernon,
  Windsor, Agawam, West Springfield, South Windsor, Simsbury, Ludlow,
  Bloomfield, Avon and South Hadley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms have a history of producing wind damage. For your 
protection move to an interior room on the lowest floor of a 
building.

&&

LAT...LON 4226 7271 4220 7208 4168 7247 4181 7295
      4183 7294 4185 7295 4188 7295 4189 7294
      4190 7291 4197 7289 4197 7303 4204 7301
      4204 7305 4205 7306
TIME...MOT...LOC 2134Z 281DEG 29KT 4220 7266 4193 7311 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Nash

1 follow-up statement

198 
WWUS51 KBOX 122157
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
557 PM EDT Thu Aug 12 2021

CTC003-013-MAC013-015-027-122230-
/O.CON.KBOX.SV.W.0098.000000T0000Z-210812T2230Z/
Tolland CT-Hartford CT-Worcester MA-Hampshire MA-Hampden MA-
557 PM EDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR NORTHWESTERN TOLLAND...HARTFORD...SOUTHWESTERN WORCESTER...
SOUTHERN HAMPSHIRE AND SOUTHEASTERN HAMPDEN COUNTIES...

At 556 PM EDT, severe thunderstorms were located along a line
extending from near Ludlow to near Simsbury, moving east at 35 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Springfield, Hartford, West Hartford, Manchester, Chicopee, East
Hartford, Enfield, Westfield, Glastonbury, Vernon, Windsor, Agawam,
West Springfield, South Windsor, Simsbury, Ludlow, Bloomfield, Avon,
Longmeadow and Suffield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms have a history of producing wind damage. SEEK SHELTER 
NOW inside a sturdy structure and stay away from windows.
 
&&

LAT...LON 4223 7247 4220 7208 4168 7247 4181 7295
      4183 7294 4185 7295 4188 7295 4189 7294
      4190 7291 4197 7289 4197 7303 4198 7303
TIME...MOT...LOC 2156Z 281DEG 29KT 4217 7242 4190 7287 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Nash

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 12, 2:53 PM EDT	Heat Advisory	BOX	Barnstable, Bristol, Essex, Franklin, Hampden, Hampshire and 5 more	29 hr
Aug 12, 3:45 PM EDT	Special Weather Statement	BOX	Franklin, Hampshire	60 min
Aug 12, 4:45 PM EDT	Special Weather Statement	BOX	Franklin, Hampden, Hampshire	60 min
Aug 12, 5:02 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire	58 min
Aug 12, 5:42 PM EDT	Special Weather Statement	BOX	Worcester	48 min
Aug 12, 5:51 PM EDT	Severe Thunderstorm Warning Considerable damage threat	BOX	Franklin, Hampden, Hampshire, Worcester	39 min
Aug 12, 6:13 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Hampden, Middlesex, Norfolk, Worcester	62 min
Aug 12, 6:52 PM EDT	Special Marine Warning	BOX		53 min
Aug 12, 7:14 PM EDT	Special Weather Statement	BOX	Bristol, Plymouth	61 min
Aug 12, 6:26 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	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.