Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 93, NWS Boston/Norton, MA

July 27, 2021Capitol Planning Region, Connecticut; Franklin County, Hampden County, Hampshire County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 27, 2021, 5:34 PM EDT for Capitol Planning Region, Connecticut; Franklin County, Hampden County, Hampshire County, Massachusetts. It was in force for 56 min. 8 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, 5:34 PM EDT (21:34 UTC)
Expired
Jul 27, 2021, 6:30 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 Capitol Planning Region, CT, Franklin County, MA, Hampden County, MA, Hampshire County, MA

The radar

The Albany radar (KENX), 103 km from the middle of the area, began a volume at 21:34 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, 5:39 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, 6:06 PM EDTTSTM WND DMGChesterfield, MATREE DOWN ON WIRES NEAR 46 BRAY ROAD. RELAYED BY AMATEUR RADIO.
Jul 27, 6:13 PM EDTTSTM WND DMGRussell, MATREE DOWN NEAR 185 HUNTINGTON ROAD (ROUTE 20). RELAYED BY AMATEUR RADIO.
Jul 27, 6:25 PM EDTTSTM WND DMG4 E Sandsfield, MATREE DOWNED ACROSS ROUTE 8
Jul 27, 6:28 PM EDTTSTM WND DMGAgawam, MAWIRES DOWN NEAR 1004 NORTH WEST STREET.
Jul 27, 6:28 PM EDTTSTM WND DMGWest Springfield, MAUTILITY POLE DOWN ON ROUTE 20 AT DEWEY STREET. TREE DOWN ON WIRES BIRNIE AVE.

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, 9.6 hours before the alert went out and 92 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.

590 
WUUS51 KBOX 272134
SVRBOX
CTC003-MAC011-013-015-272230-
/O.NEW.KBOX.SV.W.0093.210727T2134Z-210727T2230Z/

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

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northern Hartford County in northern Connecticut...
  Hampshire County in western Massachusetts...
  South central Franklin 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 near Cheshire to near Lee to Sheffield, moving
  southeast at 35 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Springfield, Chicopee, Enfield, Westfield, Holyoke, Amherst,
  Northampton, Agawam, West Springfield, Ludlow, South Hadley,
  Easthampton, Longmeadow, Suffield, East Longmeadow, Belchertown,
  Wilbraham, Windsor Locks, Somers and East Windsor.

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 these storms. 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 these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4215 7307 4214 7305 4215 7303 4231 7300
      4231 7303 4233 7306 4238 7307 4238 7301
      4250 7298 4232 7235 4208 7249 4191 7253
      4199 7303 4204 7301 4204 7306
TIME...MOT...LOC 2134Z 293DEG 31KT 4252 7316 4231 7317 4213 7334 

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

Loconto/Gaucher
2 follow-up statements
344 
WWUS51 KBOX 272211
SVSBOX

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

CTC003-MAC011-013-015-272230-
/O.CON.KBOX.SV.W.0093.000000T0000Z-210727T2230Z/
Hartford CT-Hampshire MA-Franklin MA-Hampden MA-
611 PM EDT Tue Jul 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR NORTHERN HARTFORD...HAMPSHIRE...SOUTH CENTRAL FRANKLIN AND
HAMPDEN COUNTIES...

At 610 PM EDT, severe thunderstorms were located along a line
extending from near Cummington to near Montgomery to near Tolland,
moving southeast at 35 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Springfield, Chicopee, Enfield, Westfield, Holyoke, Amherst,
Northampton, Agawam, West Springfield, Ludlow, South Hadley,
Easthampton, Longmeadow, Suffield, East Longmeadow, Belchertown,
Wilbraham, Windsor Locks, Somers and East Windsor.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with these storms.
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 these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4215 7307 4214 7305 4215 7303 4231 7300
      4231 7303 4233 7306 4238 7307 4238 7301
      4250 7298 4232 7235 4208 7249 4191 7253
      4199 7303 4204 7301 4204 7306
TIME...MOT...LOC 2210Z 293DEG 31KT 4243 7288 4222 7289 4204 7306 

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

Loconto
949 
WWUS51 KBOX 272226
SVSBOX

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

CTC003-MAC011-013-015-272236-
/O.EXP.KBOX.SV.W.0093.000000T0000Z-210727T2230Z/
Hartford CT-Hampshire MA-Franklin MA-Hampden MA-
626 PM EDT Tue Jul 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN HARTFORD...
HAMPSHIRE...SOUTH CENTRAL FRANKLIN AND HAMPDEN COUNTIES WILL EXPIRE
AT 630 PM EDT...
            
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 with these thunderstorms.

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

LAT...LON 4215 7307 4214 7305 4215 7303 4231 7300
      4231 7303 4233 7306 4238 7307 4238 7301
      4250 7298 4232 7235 4208 7249 4191 7253
      4199 7303 4204 7301 4204 7306
TIME...MOT...LOC 2226Z 293DEG 31KT 4243 7288 4222 7289 4204 7306 

$$

Gaucher/Loconto

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 6:27 PM EDTSpecial Weather StatementBOX48 min
Jul 27, 6:53 PM EDTSpecial Weather StatementBOX37 min
Jul 27, 7:01 PM EDTSevere Thunderstorm WarningBOXNortheastern Connecticut Planning Region44 min
Jul 27, 7:21 PM EDTSpecial Weather StatementBOX39 min
Jul 27, 4:48 PM EDTSpecial Weather StatementBOXFranklin27 min
Jul 27, 4:59 PM EDTSpecial Weather StatementBOXHampshire31 min
Jul 27, 5:04 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire56 min
Jul 27, 5:15 PM EDTSpecial Weather StatementBOXFranklin30 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, 7:11 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, 2021Severe Thunderstorm Warnings in Connecticut, 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.