Alert archive / Connecticut / Tornado Warnings in 2021

Tornado Warning 15, NWS Boston/Norton, MA

September 9, 2021Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this tornado warning at Sep 9, 2021, 4:13 AM EDT for Northeastern Connecticut Planning Region, Connecticut. It was in force for 11 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: Sep 9, 2021, 4:13 AM EDT (08:13 UTC)
Expired: Sep 9, 2021, 4:24 AM EDT
In force: 11 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Northeastern Connecticut Planning Region, CT

The radar

The Boston radar (KBOX), 86 km from the middle of the area, began a volume at 08:15 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, 8.2 hours before the alert went out and 121 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: 619 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 807 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 211 m²/s²
0-3 km storm-relative helicity: 225 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.4

Open this sounding in Storm Lab

The text

As transmitted.

572 
WFUS51 KBOX 090813
TORBOX
CTC013-015-090900-
/O.NEW.KBOX.TO.W.0015.210909T0813Z-210909T0900Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Boston/Norton MA
413 AM EDT Thu Sep 9 2021

The National Weather Service in Boston/Norton has issued a

* Tornado Warning for...
  Central Windham County in northern Connecticut...
  Central Tolland County in northern Connecticut...

* Until 500 AM EDT.
    
* At 412 AM EDT, a severe thunderstorm capable of producing a tornado
  was located near Coventry, or near Mansfield, moving northeast at
  30 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...
  Chaplin around 435 AM EDT.
  Ashford, Hampton and Eastford around 440 AM EDT.
  Woodstock and Pomfret around 455 AM EDT.
  Putnam around 500 AM EDT.

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 4170 7228 4179 7236 4201 7202 4187 7187
TIME...MOT...LOC 0812Z 236DEG 25KT 4177 7229 

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

$$

RM

1 follow-up statement

803 
WWUS51 KBOX 090824
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
424 AM EDT Thu Sep 9 2021

CTC013-015-090834-
/O.CAN.KBOX.TO.W.0015.000000T0000Z-210909T0900Z/
Windham CT-Tolland CT-
424 AM EDT Thu Sep 9 2021

...THE TORNADO WARNING FOR CENTRAL WINDHAM AND CENTRAL TOLLAND
COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been cancelled.

LAT...LON 4170 7228 4179 7236 4201 7202 4187 7187
TIME...MOT...LOC 0822Z 236DEG 25KT 4182 7220 

$$

RM

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 9, 3:33 AM EDT	Special Weather Statement	BOX		42 min
Sep 9, 3:50 AM EDT	Tornado Warning	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	25 min

Nearby

Tornado Warnings in Connecticut, 2021 Every tornado warning in 2021 Tornadoes 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.