Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 113, NWS Boston/Norton, MA

September 16, 2021Bristol County, Plymouth County, Massachusetts; Bristol County, Newport County, Rhode Island

NWS Boston/Norton, MA issued this severe thunderstorm warning at Sep 16, 2021, 6:38 AM EDT for Bristol County, Plymouth County, Massachusetts; Bristol County, Newport County, Rhode Island. It was in force for 53 min. 1 report 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
Sep 16, 2021, 6:38 AM EDT (10:38 UTC)
Expired
Sep 16, 2021, 7:31 AM EDT
In force
53 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Bristol County, MA, Plymouth County, MA, Bristol County, RI, Newport County, RI

The radar

The Boston radar (KBOX), 37 km from the middle of the area, began a volume at 10:40 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
Sep 16, 7:00 AM EDTTSTM WND DMGWestport, MATREE AND WIRES DOWN ON HORSENECK ROAD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 10.6 hours before the alert went out and 170 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 2021-09-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 664 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 172 square meters per square second.193958Sfc1 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
664 J/kg
Mixed-layer CIN
-93 J/kg
Mixed-layer LCL
1000 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.4

Open this sounding in Storm Lab

The text

As transmitted.

877 
WUUS51 KBOX 161038
SVRBOX
MAC005-023-RIC001-005-161145-
/O.NEW.KBOX.SV.W.0113.210916T1038Z-210916T1145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
638 AM EDT Thu Sep 16 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Southwestern Plymouth County in southeastern Massachusetts...
  Southeastern Bristol County in southeastern Massachusetts...
  Newport County in Rhode Island...
  Southeastern Bristol County in Rhode Island...

* Until 745 AM EDT.

* At 638 AM EDT, a severe thunderstorm was located over Tiverton, or
  near Bristol, moving northeast at 20 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  New Bedford, Fall River, Dartmouth, Newport, Bristol, Marion,
  Middleborough, Wareham, Somerset, Portsmouth, Middletown,
  Fairhaven, Tiverton, Westport, Carver, Lakeville, Acushnet,
  Freetown, Mattapoisett and Rochester.

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.

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

&&

LAT...LON 4146 7133 4159 7128 4158 7134 4163 7134
      4160 7129 4166 7127 4168 7124 4164 7121
      4172 7117 4192 7082 4173 7068 4171 7077
      4165 7076 4165 7092 4159 7090 4161 7093
      4158 7093 4149 7120 4164 7123 4148 7124
TIME...MOT...LOC 1038Z 240DEG 19KT 4160 7121 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Loconto
2 follow-up statements
888 
WWUS51 KBOX 161103
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
703 AM EDT Thu Sep 16 2021

RIC001-161113-
/O.CAN.KBOX.SV.W.0113.000000T0000Z-210916T1145Z/
Bristol RI-
703 AM EDT Thu Sep 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BRISTOL COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4151 7113 4166 7120 4167 7119 4183 7075
      4173 7068 4171 7077 4165 7076 4165 7092
      4159 7090 4161 7093 4158 7093
TIME...MOT...LOC 1103Z 249DEG 20KT 4162 7098 

$$

MAC005-023-RIC005-161145-
/O.CON.KBOX.SV.W.0113.000000T0000Z-210916T1145Z/
Plymouth MA-Bristol MA-Newport RI-
703 AM EDT Thu Sep 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 AM EDT
FOR SOUTH CENTRAL PLYMOUTH...SOUTHEASTERN BRISTOL AND NORTHEASTERN
NEWPORT COUNTIES...

At 703 AM EDT, a severe thunderstorm was located near Dartmouth,
moving east at 25 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
New Bedford, Fall River, Dartmouth, Marion, Middleborough, Wareham,
Fairhaven, Tiverton, Westport, Carver, Acushnet, Freetown,
Mattapoisett, Rochester and Little Compton.

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 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 4151 7113 4166 7120 4167 7119 4183 7075
      4173 7068 4171 7077 4165 7076 4165 7092
      4159 7090 4161 7093 4158 7093
TIME...MOT...LOC 1103Z 249DEG 20KT 4162 7098 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Loconto
971 
WWUS51 KBOX 161131
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
731 AM EDT Thu Sep 16 2021

MAC005-023-RIC005-161141-
/O.CAN.KBOX.SV.W.0113.000000T0000Z-210916T1145Z/
Plymouth MA-Bristol MA-Newport RI-
731 AM EDT Thu Sep 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL PLYMOUTH...
SOUTHEASTERN BRISTOL AND NORTHEASTERN NEWPORT COUNTIES IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

LAT...LON 4151 7113 4166 7120 4167 7119 4183 7075
      4173 7068 4171 7077 4165 7076 4165 7092
      4159 7090 4161 7093 4158 7093
TIME...MOT...LOC 1124Z 240DEG 19KT 4170 7081 

$$

Loconto

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 5:43 AM EDTSpecial Marine WarningBOX62 min
Sep 16, 6:10 AM EDTSpecial Weather StatementBOXEssex, Norfolk65 min
Sep 16, 6:13 AM EDTSpecial Weather StatementBOXNorfolk62 min
Sep 16, 6:24 AM EDTSpecial Weather StatementBOXBristol66 min
Sep 16, 6:42 AM EDTSpecial Marine WarningBOX63 min
Sep 16, 7:00 AM EDTSpecial Marine WarningBOX60 min
Sep 16, 7:13 AM EDTSevere Thunderstorm WarningBOXBarnstable, Bristol, Dukes, Plymouth62 min
Sep 16, 7:25 AM EDTSpecial Marine WarningBOX65 min
Sep 16, 7:27 AM EDTSpecial Marine WarningBOX63 min
Sep 16, 7:36 AM EDTSevere Thunderstorm WarningBOXBarnstable, Dukes54 min
Sep 16, 7:51 AM EDTSpecial Marine WarningBOX54 min
Sep 16, 7:59 AM EDTSpecial Weather StatementBOXBarnstable, Dukes61 min
Sep 16, 8:15 AM EDTSpecial Marine WarningBOX90 min
Sep 16, 8:37 AM EDTSpecial Marine WarningBOX40 min
Sep 16, 9:31 AM EDTSpecial Marine WarningBOX59 min
Sep 16, 3:18 PM EDTSmall Craft AdvisoryBOX3 days
Sep 16, 5:15 AM EDTSpecial Weather StatementBOXProvidence60 min
Sep 16, 6:35 AM EDTSpecial Weather StatementBOXWashington55 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2021Severe Thunderstorm Warnings in Rhode Island, 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.