Alert archive / Massachusetts / Tornado Warnings in 2020

Tornado Warning 8, NWS Boston/Norton, MA

November 23, 2020Barnstable County, Dukes County, Massachusetts

NWS Boston/Norton, MA issued this tornado warning at Nov 23, 2020, 11:23 AM EST for Barnstable County, Dukes County, Massachusetts. It was in force for 37 min. 2 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: Nov 23, 2020, 11:23 AM EST (16:23 UTC)
Expired: Nov 23, 2020, 12:00 PM EST
In force: 37 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Barnstable County, MA, Dukes County, MA

The radar

The Boston radar (KBOX), 79 km from the middle of the area, began a volume at 16:26 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

Time	Report	Where	Remark
Nov 23, 11:50 AM EST	TSTM WND GST 63	Hyannis, MA	WEATHERFLOW SITE
Nov 23, 11:50 AM EST	NON-TSTM WND GST 63	Hyannis, MA	WEATHERFLOW SITE

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

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 4.4 hours before the alert went out and 33 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: 201 J/kg
Mixed-layer CIN: -26 J/kg
Mixed-layer LCL: 574 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 285 m²/s²
0-3 km storm-relative helicity: 321 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

146 
WFUS51 KBOX 231623
TORBOX
MAC001-007-231700-
/O.NEW.KBOX.TO.W.0008.201123T1623Z-201123T1700Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Boston/Norton MA
1123 AM EST Mon Nov 23 2020

The National Weather Service in Boston/Norton has issued a

* Tornado Warning for...
  Northeastern Dukes County in southeastern Massachusetts...
  Southeastern Barnstable County in southeastern Massachusetts...

* Until noon EST.
    
* At 1122 AM EST, a severe thunderstorm capable of producing a
  tornado was located near Edgartown, moving northeast at 50 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Yarmouth and Dennis around 1145 AM EST.
  Brewster and Harwich around 1150 AM EST.

Other locations impacted by this tornadic thunderstorm include
Hyannis.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4166 6999 4160 7046 4141 7045 4155 7051
      4153 7052 4135 7045 4138 7047 4144 7050
      4135 7050 4135 7063 4136 7063 4174 7041
      4173 7031 4172 7035 4171 7030 4176 7014
      4173 6994 4174 6993
TIME...MOT...LOC 1622Z 211DEG 70KT 4130 7053 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Nocera

1 follow-up statement

683 
WWUS51 KBOX 231640
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
1140 AM EST Mon Nov 23 2020

MAC001-007-231700-
/O.CON.KBOX.TO.W.0008.000000T0000Z-201123T1700Z/
Dukes MA-Barnstable MA-
1140 AM EST Mon Nov 23 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL NOON EST FOR EAST
CENTRAL DUKES AND SOUTHEASTERN BARNSTABLE COUNTIES...
    
At 1136 AM EST, a severe thunderstorm capable of producing a tornado
was located 8 miles south of Barnstable, moving northeast at 50 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation. At 1132 AM in Edgartown MA on 
         Marthas Vineyard a gusts to 45 mph was reported by 
         Skywarn spotter.  

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Yarmouth around 1140 AM EST.
  Dennis and Harwich around 1145 AM EST.
  Brewster around 1150 AM EST.

Other locations impacted by this tornadic thunderstorm include
Hyannis.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4166 6999 4160 7046 4141 7045 4155 7051
      4153 7052 4137 7046 4138 7047 4144 7050
      4140 7050 4141 7053 4148 7056 4174 7041
      4173 7031 4172 7035 4171 7030 4176 7014
      4174 6997 4174 6993
TIME...MOT...LOC 1636Z 211DEG 70KT 4155 7033 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Nocera

The office that day

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

Issued	Product	Office	Counties	Lasted
Nov 23, 10:35 AM EST	Special Marine Warning	BOX		25 min
Nov 23, 10:37 AM EST	Special Marine Warning	BOX		23 min
Nov 23, 10:55 AM EST	Special Marine Warning	BOX		65 min
Nov 23, 11:54 AM EST	Severe Thunderstorm Warning	BOX	Nantucket	17 min
Nov 23, 11:58 AM EST	Severe Thunderstorm Warning	BOX	Barnstable	21 min
Nov 23, 12:01 PM EST	Special Marine Warning	BOX		29 min
Nov 23, 12:25 PM EST	Special Marine Warning	BOX		35 min
Nov 23, 1:01 PM EST	Special Marine Warning	BOX		29 min
Nov 23, 4:10 PM EST	Small Craft Advisory	BOX		41 hr

Nearby

Tornado Warnings in Massachusetts, 2020 Every tornado warning in 2020 Tornadoes in 2020

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.