Alert archive / Connecticut / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 72, NWS Boston/Norton, MA

July 16, 2021Northeastern Connecticut Planning Region, Connecticut; Providence County, Rhode Island; Hampden County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 16, 2021, 5:05 PM EDT for Northeastern Connecticut Planning Region, Connecticut; Providence County, Rhode Island; Hampden County, Worcester County, Massachusetts. It was in force for 55 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
Jul 16, 2021, 5:05 PM EDT (21:05 UTC)
Expired
Jul 16, 2021, 6:00 PM EDT
In force
55 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Northeastern Connecticut Planning Region, CT, Hampden County, MA, Worcester County, MA, Providence County, RI

The radar

The Boston radar (KBOX), 70 km from the middle of the area, began a volume at 21:06 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 12:00Z, 9.1 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-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2021-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1044 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 12:00Z on 2021-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.1939Sfc1 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
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.

640 
WUUS51 KBOX 162105
SVRBOX
CTC013-015-MAC013-027-RIC007-162200-
/O.NEW.KBOX.SV.W.0072.210716T2105Z-210716T2200Z/

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

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northern Windham County in northern Connecticut...
  Northeastern Tolland County in northern Connecticut...
  South central Worcester County in central Massachusetts...
  Southeastern Hampden County in western Massachusetts...
  Northwestern Providence County in Rhode Island...

* Until 600 PM EDT.

* At 504 PM EDT, a severe thunderstorm was located near Union, or 15
  miles northeast of Mansfield, moving east at 20 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Smithfield, Killingly, Webster, Southbridge, Burrillville, Oxford,
  Uxbridge, Charlton, Stafford, North Smithfield, Dudley, Scituate,
  Glocester, Putnam, Thompson, Sturbridge, Douglas, Woodstock,
  Willington and Mendon.

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 4190 7224 4210 7225 4207 7156 4181 7160
TIME...MOT...LOC 2104Z 276DEG 18KT 4199 7210 

HAIL...0.88IN
WIND...60MPH
 
$$

Gaucher/Nocera

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 2:59 PM EDTFlash Flood WatchBOXCapitol Planning Region, Northeastern Connecticut Planning Region56 hr
Jul 16, 3:04 PM EDTSevere Thunderstorm WarningBOXNortheastern Connecticut Planning Region56 min
Jul 16, 5:14 PM EDTSpecial Weather StatementBOX46 min
Jul 16, 5:31 PM EDTSevere Thunderstorm WarningBOXCapitol Planning Region, Northeastern Connecticut Planning Region42 min
Jul 16, 5:47 PM EDTSevere Thunderstorm WarningBOXProvidence33 min
Jul 16, 6:17 PM EDTSpecial Weather StatementBOXBristol, Kent, Providence58 min
Jul 16, 9:38 AM EDTHeat AdvisoryBOXBristol, Essex, Middlesex, Norfolk, Plymouth, Suffolk9 hr
Jul 16, 3:41 PM EDTSpecial Weather StatementBOXHampden49 min
Jul 16, 4:26 PM EDTSpecial Weather StatementBOXNorfolk, Suffolk49 min
Jul 16, 4:36 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Worcester35 min
Jul 16, 4:50 PM EDTSpecial Marine WarningBOX55 min
Jul 16, 6:32 PM EDTSpecial Marine WarningBOX43 min

Nearby

Severe Thunderstorm Warnings in Connecticut, 2021Severe 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.