Alert archive / Connecticut / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 76, NWS Boston/Norton, MA

July 17, 2021Northeastern Connecticut Planning Region, Connecticut; Providence County, Rhode Island

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 17, 2021, 3:26 PM EDT for Northeastern Connecticut Planning Region, Connecticut; Providence County, Rhode Island. It was in force for 64 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: Jul 17, 2021, 3:26 PM EDT (19:26 UTC)
Expired: Jul 17, 2021, 4:30 PM EDT
In force: 64 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Northeastern Connecticut Planning Region, CT, Providence County, RI

The radar

The Boston radar (KBOX), 61 km from the middle of the area, began a volume at 19:24 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 17, 3:55 PM EDT	TSTM WND DMG	Pomfret, CT	TREES AND WIRES DOWN ON ANDERSON ROAD AND HAMLET HILL 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 12:00Z, 7.4 hours before the alert went out and 142 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: 1203 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 1054 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted.

074 
WUUS51 KBOX 171926
SVRBOX
CTC015-RIC007-172030-
/O.NEW.KBOX.SV.W.0076.210717T1926Z-210717T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
326 PM EDT Sat Jul 17 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northeastern Windham County in northern Connecticut...
  Western Providence County in Rhode Island...

* Until 430 PM EDT.

* At 326 PM EDT, a severe thunderstorm was located over Pomfret, or
  14 miles north of Plainfield, moving east at 15 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Killingly, Burrillville, Scituate, Glocester, Putnam, Thompson,
  Brooklyn, Woodstock, Foster, Pomfret, Hampton and Eastford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4182 7209 4198 7209 4201 7170 4201 7161
      4175 7162
TIME...MOT...LOC 1926Z 271DEG 11KT 4190 7196 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

Chai

1 follow-up statement

240 
WWUS51 KBOX 172002
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
402 PM EDT Sat Jul 17 2021

CTC015-RIC007-172030-
/O.CON.KBOX.SV.W.0076.000000T0000Z-210717T2030Z/
Windham CT-Providence RI-
402 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR NORTHEASTERN WINDHAM AND WESTERN PROVIDENCE COUNTIES...

At 402 PM EDT, a severe thunderstorm was located near Putnam, or 14
miles north of Plainfield, moving east at 15 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Killingly, Burrillville, Scituate, Glocester, Putnam, Thompson,
Brooklyn, Woodstock, Foster, Pomfret, Hampton and Eastford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4182 7209 4198 7209 4201 7170 4201 7161
      4175 7162
TIME...MOT...LOC 2002Z 271DEG 11KT 4190 7181 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

Chai

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 1:59 PM EDT	Special Weather Statement	BOX		46 min
Jul 17, 3:47 PM EDT	Areal Flood Warning	BOX	Northeastern Connecticut Planning Region	118 min
Jul 17, 4:14 PM EDT	Flash Flood Warning	BOX	Northeastern Connecticut Planning Region	5 hr
Jul 17, 4:15 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	60 min
Jul 17, 4:18 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	57 min
Jul 17, 4:20 PM EDT	Special Weather Statement	BOX		40 min
Jul 17, 4:29 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	61 min
Jul 17, 4:38 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region	67 min
Jul 17, 4:58 PM EDT	Flash Flood Warning	BOX	Capitol Planning Region	2 hr
Jul 17, 5:21 PM EDT	Flash Flood Warning	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	5 hr
Jul 17, 5:30 PM EDT	Flash Flood Warning	BOX	Northeastern Connecticut Planning Region	3 hr
Jul 17, 2:14 PM EDT	Special Weather Statement	BOX	Bristol	46 min
Jul 17, 2:39 PM EDT	Areal Flood Warning	BOX	Kent, Providence	111 min
Jul 17, 2:46 PM EDT	Special Weather Statement	BOX	Providence	44 min
Jul 17, 2:53 PM EDT	Severe Thunderstorm Warning	BOX	Providence	52 min
Jul 17, 3:36 PM EDT	Areal Flood Warning	BOX	Kent, Providence	114 min
Jul 17, 4:06 PM EDT	Flash Flood Warning	BOX	Kent, Providence	4 hr
Jul 17, 5:49 PM EDT	Special Weather Statement	BOX	Bristol	41 min
Jul 17, 6:05 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Kent, Providence	26 min

Nearby

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