Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 92, NWS Boston/Norton, MA

July 27, 2021Franklin County, Hampden County, Hampshire County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 27, 2021, 5:04 PM EDT for Franklin County, Hampden County, Hampshire County, Massachusetts. It was in force for 56 min. 10 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
Jul 27, 2021, 5:04 PM EDT (21:04 UTC)
Expired
Jul 27, 2021, 6:00 PM EDT
In force
56 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

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

The radar

The Albany radar (KENX), 112 km from the middle of the area, began a volume at 21:04 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
Jul 27, 5:18 PM EDTTSTM WND DMGCummington, MAWIRES DOWN ON MAIN STREET
Jul 27, 5:20 PM EDTTSTM WND DMGCummington, MATREES AND WIRES DOWN ON PLAINFIELD ROAD
Jul 27, 5:23 PM EDTTSTM WND DMGGoshen, MATREE DOWN ON ROUTE 9. TREE DOWN ON BERKSHIRE TRAIL. RELAYED BY AMATEUR RADIO.
Jul 27, 5:31 PM EDTTSTM WND DMGWhately, MATREE IN DOWN ON HAYDENVILLE ROAD BY WESTBROOK ROAD. TREE DOWN ON I-91 SOUTH. RELAYED BY AMATEUR RADIO.
Jul 27, 5:39 PM EDTTSTM WND DMGNorthampton, MATREE DOWN ON WIRES. RELAYED BY AMATEUR RADIO.
Jul 27, 5:40 PM EDTTSTM WND DMGHatfield, MATREE DOWN ON A CAR ON WEST ST. TREE DOWN ON NORTH STREET. RELAYED BY AMATEUR RADIO.
Jul 27, 5:40 PM EDTTSTM WND DMGHatfield, MATREE DOWN AT 90 LINDSEED ROAD. TREE DOWN ON ARNOLD ROAD. RELAYED BY AMATEUR RADIO.
Jul 27, 5:45 PM EDTTSTM WND DMGAmherst, MATREE BRANCHES DOWN ON SOUTH WHITNEY STREET BY COLLEGE STREET, AND ALSO ON EAST PLEASANT STREET BY OWEN DRIVE. WIRES DOWN ON 34 BAKER STREET. RELAYED BY AMATEUR RADIO.
Jul 27, 5:46 PM EDTTSTM WND DMGPelham, MAWIRES DOWN ON AMHERST ROAD NEAR ENFIELD ROAD. RELAYED BY AMATEUR RADIO.
Jul 27, 6:06 PM EDTTSTM WND DMGChesterfield, MATREE DOWN ON WIRES NEAR 46 BRAY ROAD. RELAYED BY AMATEUR RADIO.

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
Jul 27, 2:47 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 9.1 hours before the alert went out and 97 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 2021-07-27Temperature 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 12:00Z on 2021-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.19395878Sfc1 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
1464 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
46 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

337 
WUUS51 KBOX 272104
SVRBOX
MAC011-013-015-272200-
/O.NEW.KBOX.SV.W.0092.210727T2104Z-210727T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
504 PM EDT Tue Jul 27 2021

The National Weather Service in Boston/Norton has issued a

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

* Until 600 PM EDT.

* At 503 PM EDT, a severe thunderstorm was located over East Windsor,
  or 15 miles east of Pittsfield, moving southeast at 40 mph.

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

  SOURCE...Radar indicated. This storm has downed trees in portions 
           of central Berkshire County.

  IMPACT...Expect wind damage to trees and power lines. Minor hail 
           damage to vehicles is possible.

* Locations impacted include...
  Springfield, Chicopee, Holyoke, Amherst, Northampton, Deerfield,
  Ludlow, South Hadley, Easthampton, Belchertown, Wilbraham, Ware,
  Montague, Granby, Southampton, Hadley, Sunderland, Hatfield,
  Williamsburg and Huntington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 4239 7305 4238 7301 4263 7295 4244 7229
      4240 7232 4234 7231 4210 7246 4238 7307
TIME...MOT...LOC 2103Z 299DEG 33KT 4246 7296 

HAIL...1.00IN
WIND...60MPH
 
$$

Loconto/Gaucher
3 follow-up statements
003 
WWUS51 KBOX 272125
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
525 PM EDT Tue Jul 27 2021

MAC011-013-015-272200-
/O.CON.KBOX.SV.W.0092.000000T0000Z-210727T2200Z/
Hampshire MA-Franklin MA-Hampden MA-
525 PM EDT Tue Jul 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR HAMPSHIRE...CENTRAL FRANKLIN AND CENTRAL HAMPDEN COUNTIES...

At 524 PM EDT, a severe thunderstorm was located over Goshen, or 7
miles northwest of Northampton, moving southeast at 35 mph.

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

SOURCE...Trained weather spotters. At 518 PM, powerline wires were 
         downed in Cummington from this severe thunderstorm.

IMPACT...Expect wind damage to trees and power lines. Minor hail 
         damage to vehicles is possible.

Locations impacted include...
Springfield, Chicopee, Holyoke, Amherst, Northampton, Deerfield,
Ludlow, South Hadley, Easthampton, Belchertown, Wilbraham, Ware,
Montague, Granby, Southampton, Hadley, Sunderland, Hatfield,
Williamsburg and Huntington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4239 7305 4238 7301 4263 7295 4244 7229
      4240 7232 4234 7231 4210 7246 4238 7307
TIME...MOT...LOC 2124Z 297DEG 30KT 4240 7278 

HAIL...1.00IN
WIND...60MPH
 
$$

Loconto
903 
WWUS51 KBOX 272140
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
540 PM EDT Tue Jul 27 2021

MAC011-013-015-272200-
/O.CON.KBOX.SV.W.0092.000000T0000Z-210727T2200Z/
Hampshire MA-Franklin MA-Hampden MA-
540 PM EDT Tue Jul 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR HAMPSHIRE...CENTRAL FRANKLIN AND NORTH CENTRAL HAMPDEN
COUNTIES...

At 538 PM EDT, a severe thunderstorm was located over Northampton,
moving southeast at 40 mph.

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

SOURCE...Trained weather spotters. Trees were reported downed in 
         Whately and Goshen between 523 and 531 PM. Powerlines were 
         downed in Cummington at 520 PM.

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

Locations impacted include...
Holyoke, Amherst, Northampton, Deerfield, Ludlow, South Hadley,
Easthampton, Belchertown, Ware, Montague, Granby, Hadley, Sunderland,
Hatfield, Williamsburg, Buckland, Conway, Leverett, Shutesbury and
Ashfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4263 7295 4244 7229 4240 7232 4234 7231
      4218 7241 4243 7300
TIME...MOT...LOC 2138Z 299DEG 33KT 4234 7263 

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

Loconto
366 
WWUS51 KBOX 272157
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
557 PM EDT Tue Jul 27 2021

MAC011-013-015-272207-
/O.EXP.KBOX.SV.W.0092.000000T0000Z-210727T2200Z/
Hampshire MA-Franklin MA-Hampden MA-
557 PM EDT Tue Jul 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR HAMPSHIRE...CENTRAL FRANKLIN
AND NORTH CENTRAL HAMPDEN COUNTIES WILL EXPIRE AT 600 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
western and central Massachusetts.

LAT...LON 4263 7295 4244 7229 4240 7232 4234 7231
      4218 7241 4243 7300
TIME...MOT...LOC 2157Z 299DEG 33KT 4230 7252 

$$

Loconto

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 4:48 PM EDTSpecial Weather StatementBOXFranklin27 min
Jul 27, 4:59 PM EDTSpecial Weather StatementBOXHampshire31 min
Jul 27, 5:15 PM EDTSpecial Weather StatementBOXFranklin30 min
Jul 27, 5:34 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire56 min
Jul 27, 6:01 PM EDTSpecial Weather StatementBOXWorcester29 min
Jul 27, 6:33 PM EDTSevere Thunderstorm WarningBOXEssex, Middlesex, Norfolk, Plymouth, Suffolk, Worcester57 min
Jul 27, 6:50 PM EDTSpecial Weather StatementBOXEssex25 min
Jul 27, 6:52 PM EDTSpecial Marine WarningBOX53 min
Jul 27, 7:01 PM EDTSevere Thunderstorm WarningBOXHampden, Worcester44 min
Jul 27, 7:11 PM EDTSpecial Marine WarningBOX94 min
Jul 27, 7:26 PM EDTSevere Thunderstorm WarningBOXBristol, Essex, Middlesex, Norfolk, Plymouth, Suffolk and 1 more64 min
Jul 27, 7:39 PM EDTSpecial Marine WarningBOX66 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.