Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 122, NWS Boston/Norton, MA

October 31, 2021Barnstable County, Dukes County, Plymouth County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Oct 31, 2021, 2:26 AM EDT for Barnstable County, Dukes County, Plymouth County, Massachusetts. It was in force for 31 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
Oct 31, 2021, 2:26 AM EDT (06:26 UTC)
Expired
Oct 31, 2021, 2:57 AM EDT
In force
31 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Barnstable County, MA, Dukes County, MA, Plymouth County, MA

The radar

The Boston radar (KBOX), 70 km from the middle of the area, began a volume at 06:28 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 00:00Z, 6.4 hours before the alert went out and 214 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, Brookhaven, NY at 00:00Z on 2021-10-31Temperature 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, Brookhaven, NY at 00:00Z on 2021-10-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 square meters per square second.1939587897Sfc1 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
854 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
159 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

092 
WUUS51 KBOX 310626
SVRBOX
MAC001-007-023-310715-
/O.NEW.KBOX.SV.W.0122.211031T0626Z-211031T0715Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
226 AM EDT Sun Oct 31 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northeastern Dukes County in southeastern Massachusetts...
  Southwestern Barnstable County in southeastern Massachusetts...
  Southeastern Plymouth County in southeastern Massachusetts...

* Until 315 AM EDT.

* At 225 AM EDT, a severe thunderstorm was located 7 miles southeast
  of Edgartown, moving north at 45 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Barnstable, Falmouth, Oak Bluffs, Edgartown, Tisbury, Sandwich,
  Bourne, Mashpee, West Tisbury and Hyannis.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4153 7068 4168 7062 4166 7065 4170 7067
      4173 7028 4172 7027 4172 7030 4171 7026
      4164 7028 4160 7047 4141 7045 4155 7051
      4155 7052 4135 7045 4137 7046 4144 7050
      4135 7050 4135 7061
TIME...MOT...LOC 0625Z 172DEG 39KT 4127 7042 

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

$$

Chai
1 follow-up statement
618 
WWUS51 KBOX 310657
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
257 AM EDT Sun Oct 31 2021

MAC001-007-023-310707-
/O.CAN.KBOX.SV.W.0122.000000T0000Z-211031T0715Z/
Dukes MA-Barnstable MA-Plymouth MA-
257 AM EDT Sun Oct 31 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DUKES...
SOUTHWESTERN BARNSTABLE AND SOUTHEASTERN PLYMOUTH 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.  However heavy rain is
still possible with this thunderstorm.

LAT...LON 4153 7068 4168 7062 4166 7065 4170 7067
      4173 7028 4172 7027 4172 7030 4171 7026
      4164 7028 4160 7047 4141 7045 4155 7051
      4155 7052 4135 7045 4137 7046 4144 7050
      4135 7050 4135 7061
TIME...MOT...LOC 0655Z 172DEG 39KT 4162 7049 

$$

Chai

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 31, 2:01 AM EDTSpecial Marine WarningBOX59 min
Oct 31, 2:13 AM EDTSpecial Weather StatementBOXDukes47 min
Oct 31, 3:11 AM EDTSpecial Weather StatementBOXPlymouth64 min
Oct 31, 3:21 AM EDTAreal Flood WarningBOXBristol, Plymouth96 min
Oct 31, 3:34 AM EDTSpecial Marine WarningBOX56 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.