Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 89, NWS Boston/Norton, MA

July 23, 2021Bristol County, Plymouth County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 23, 2021, 6:09 PM EDT for Bristol County, Plymouth County, Massachusetts. It was in force for 26 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: Jul 23, 2021, 6:09 PM EDT (22:09 UTC)
Expired: Jul 23, 2021, 6:35 PM EDT
In force: 26 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Bristol County, MA, Plymouth County, MA

The radar

The Boston radar (KBOX), 23 km from the middle of the area, began a volume at 22:09 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

Brookhaven, NY (KOKX), launched 12:00Z, 10.2 hours before the alert went out and 172 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: 1463 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: -8 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

483 
WUUS51 KBOX 232209
SVRBOX
MAC005-023-232315-
/O.NEW.KBOX.SV.W.0089.210723T2209Z-210723T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
609 PM EDT Fri Jul 23 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  West central Plymouth County in southeastern Massachusetts...
  Central Bristol County in southeastern Massachusetts...

* Until 715 PM EDT.

* At 608 PM EDT, a severe thunderstorm was located over Dighton, or
  near Taunton, moving south at 15 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...
  New Bedford, Fall River, Taunton, Dartmouth, Bridgewater,
  Attleboro, Easton, Norton, Somerset, Swansea, Westport, Raynham,
  Rehoboth, Lakeville, Acushnet, Freetown, Dighton and Berkley.

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 4169 7119 4171 7116 4171 7119 4172 7120
      4171 7121 4173 7122 4171 7123 4172 7123
      4195 7128 4200 7106 4171 7088 4167 7119
TIME...MOT...LOC 2208Z 346DEG 11KT 4185 7115 

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

Loconto

1 follow-up statement

660 
WWUS51 KBOX 232235
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
635 PM EDT Fri Jul 23 2021

MAC005-023-232244-
/O.CAN.KBOX.SV.W.0089.000000T0000Z-210723T2315Z/
Plymouth MA-Bristol MA-
635 PM EDT Fri Jul 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL PLYMOUTH AND
CENTRAL BRISTOL COUNTIES IS CANCELLED...
                
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 has been cancelled.

LAT...LON 4169 7119 4171 7116 4171 7119 4172 7120
      4171 7121 4173 7122 4171 7123 4172 7123
      4195 7128 4200 7106 4171 7088 4167 7119
TIME...MOT...LOC 2230Z 346DEG 11KT 4177 7112 

$$

Loconto

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 2:28 PM EDT	Special Weather Statement	BOX	Middlesex	32 min
Jul 23, 2:49 PM EDT	Coastal Flood Statement	BOX	Barnstable, Essex, Nantucket, Norfolk, Plymouth, Suffolk	11 hr
Jul 23, 3:04 PM EDT	Special Weather Statement	BOX	Essex	26 min
Jul 23, 3:28 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Suffolk	47 min
Jul 23, 3:29 PM EDT	Special Marine Warning	BOX		61 min
Jul 23, 4:41 PM EDT	Special Weather Statement	BOX	Essex	34 min
Jul 23, 4:57 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	63 min
Jul 23, 5:23 PM EDT	Special Weather Statement	BOX	Bristol	52 min
Jul 23, 5:50 PM EDT	Special Marine Warning	BOX		55 min
Jul 23, 6:25 PM EDT	Special Weather Statement	BOX	Plymouth	50 min
Jul 23, 6:32 PM EDT	Special Weather Statement	BOX	Worcester	43 min
Jul 23, 6:42 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Norfolk, Plymouth	48 min
Jul 23, 7:28 PM EDT	Severe Thunderstorm Warning	BOX	Plymouth	34 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.