Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 130, NWS Boston/Norton, MA

December 11, 20214 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Dec 11, 2021, 9:53 PM EST for 4 counties in Massachusetts. It was in force for 52 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
Dec 11, 2021, 9:53 PM EST (02:53 UTC)
Expired
Dec 11, 2021, 10:45 PM EST
In force
52 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 Albany radar (KENX), 100 km from the middle of the area, began a volume at 02:54 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 nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 2.9 hours before the alert went out and 87 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 00:00Z on 2021-12-12Temperature 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, Albany, NY at 00:00Z on 2021-12-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 405 square meters per square second.1939587897117136Sfc1 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
956 m above ground
0-6 km bulk shear
95 kt
0-1 km storm-relative helicity
405 m²/s²
0-3 km storm-relative helicity
481 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

322 
WUUS51 KBOX 120253
SVRBOX
MAC011-013-015-027-120345-
/O.NEW.KBOX.SV.W.0130.211212T0253Z-211212T0345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
953 PM EST Sat Dec 11 2021

The National Weather Service in Boston/Norton has issued a

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

* Until 1045 PM EST.

* At 952 PM EST, a line of intense showers capable of producing 
  damaging winds extended from 6 miles east of Bennington Vermont to 
  near Copake New York, moving east at 60 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. These storms have a history of producing 
           wind damage north of Troy, New York.

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

* Locations impacted include...
  Springfield, Chicopee, Westfield, Holyoke, Amherst, Northampton,
  Agawam, West Springfield, Greenfield, Orange, Deerfield, Ludlow,
  South Hadley, Easthampton, Longmeadow, East Longmeadow,
  Belchertown, Wilbraham, Monroe and Palmer.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4215 7307 4214 7305 4215 7303 4230 7300
      4233 7306 4238 7307 4239 7301 4266 7295
      4267 7300 4270 7295 4270 7302 4274 7302
      4271 7208 4203 7236 4204 7275 4202 7275
      4202 7281 4204 7282 4204 7306
TIME...MOT...LOC 0252Z 263DEG 51KT 4285 7307 4207 7351 

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

$$

Loconto
2 follow-up statements
171 
WWUS51 KBOX 120332
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
1032 PM EST Sat Dec 11 2021

MAC011-013-015-027-120345-
/O.CON.KBOX.SV.W.0130.000000T0000Z-211212T0345Z/
Worcester MA-Hampshire MA-Franklin MA-Hampden MA-
1032 PM EST Sat Dec 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1045 PM EST
FOR NORTHWESTERN WORCESTER...HAMPSHIRE...FRANKLIN AND HAMPDEN
COUNTIES...

At 1030 PM EST, a line of intense showers capable of producing 
damaging winds extended from Chesterfield to near Granville, moving 
east at 60 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated. Several trees and power lines were downed 
         in the town of Cheshire in Berkshire County as these 
         intense showers moved through.

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

Locations impacted include...
Springfield, Chicopee, Westfield, Holyoke, Amherst, Northampton,
Agawam, West Springfield, Greenfield, Orange, Deerfield, Ludlow,
South Hadley, Easthampton, Longmeadow, East Longmeadow, Belchertown,
Wilbraham, Palmer and Athol.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4215 7307 4214 7305 4215 7303 4230 7300
      4233 7306 4238 7307 4239 7301 4256 7290
      4264 7274 4273 7258 4271 7208 4203 7236
      4204 7275 4202 7275 4202 7281 4204 7282
      4204 7306
TIME...MOT...LOC 0330Z 263DEG 51KT 4290 7246 4213 7290 

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

$$

Loconto
168 
WWUS51 KBOX 120344
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
1044 PM EST Sat Dec 11 2021

MAC011-013-015-027-120354-
/O.EXP.KBOX.SV.W.0130.000000T0000Z-211212T0345Z/
Worcester MA-Hampshire MA-Franklin MA-Hampden MA-
1044 PM EST Sat Dec 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN WORCESTER...
HAMPSHIRE...FRANKLIN AND HAMPDEN COUNTIES WILL EXPIRE AT 1045 PM
EST...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However gusty 
winds are still possible. A wind advisory remains in effect until 5 
AM Sunday.

LAT...LON 4215 7307 4214 7305 4215 7303 4230 7300
      4233 7306 4238 7307 4239 7301 4256 7290
      4264 7274 4273 7258 4271 7208 4203 7236
      4204 7275 4202 7275 4202 7281 4204 7282
      4204 7306
TIME...MOT...LOC 0344Z 263DEG 51KT 4291 7235 4214 7279 

$$

Loconto

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 12, 9:59 AM ESTSmall Craft AdvisoryBOX53 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.