Alert archive / Connecticut / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 73, NWS Boston/Norton, MA

July 16, 2021Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 16, 2021, 5:31 PM EDT for Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut. It was in force for 42 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: Jul 16, 2021, 5:31 PM EDT (21:31 UTC)
Expired: Jul 16, 2021, 6:13 PM EDT
In force: 42 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT

The radar

The Boston radar (KBOX), 98 km from the middle of the area, began a volume at 21:30 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
Jul 16, 5:40 PM EDT	TSTM WND DMG	Andover, CT	LAKE ROAD AND MATHIESON DRIVE - TREE AND WIRES DOWN, SEVERAL BRANCHES DOWN ON 200 BLOCK OF LAKE ROAD.
Jul 16, 5:40 PM EDT	TSTM WND DMG	Andover, CT	TREES AND WIRES DOWN ON LAKE ROAD AND MATHIESON DRIVE

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 12:00Z, 9.5 hours before the alert went out and 104 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: 1044 J/kg
Mixed-layer CIN: -56 J/kg
Mixed-layer LCL: 994 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 108 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

507 
WUUS51 KBOX 162131
SVRBOX
CTC003-013-015-162230-
/O.NEW.KBOX.SV.W.0073.210716T2131Z-210716T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
531 PM EDT Fri Jul 16 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Southwestern Windham County in northern Connecticut...
  Southern Tolland County in northern Connecticut...
  Eastern Hartford County in northern Connecticut...

* Until 630 PM EDT.

* At 531 PM EDT, a severe thunderstorm was located over Andover, or 8
  miles southwest of Mansfield, moving east at 25 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Mansfield, Windham, Plainfield, Willimantic, Coventry, Hebron,
  Brooklyn, Marlborough, Columbia, Canterbury, Bolton, Andover,
  Chaplin, Hampton and Scotland.

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 4180 7244 4177 7194 4164 7197 4166 7213
      4166 7216 4171 7224 4169 7227 4167 7227
      4164 7233 4161 7233 4160 7234 4163 7247
TIME...MOT...LOC 2131Z 278DEG 12KT 4171 7236 

HAIL...<.75IN
WIND...60MPH
 
$$

Nocera

1 follow-up statement

254 
WWUS51 KBOX 162213
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
613 PM EDT Fri Jul 16 2021

CTC003-013-015-162223-
/O.CAN.KBOX.SV.W.0073.000000T0000Z-210716T2230Z/
Windham CT-Tolland CT-Hartford CT-
613 PM EDT Fri Jul 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WINDHAM...
SOUTHERN TOLLAND AND EASTERN HARTFORD 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 gusty winds and
heavy rain are still possible with this thunderstorm.

LAT...LON 4180 7244 4177 7194 4164 7197 4166 7213
      4166 7216 4171 7224 4169 7227 4167 7227
      4164 7233 4161 7233 4160 7234 4163 7247
TIME...MOT...LOC 2212Z 278DEG 12KT 4169 7218 

$$

Nocera

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 2:59 PM EDT	Flash Flood Watch	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	56 hr
Jul 16, 3:04 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	56 min
Jul 16, 5:05 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	55 min
Jul 16, 5:14 PM EDT	Special Weather Statement	BOX		46 min

Nearby

Severe Thunderstorm Warnings in Connecticut, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.