Alert archive / Connecticut / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 46, NWS Boston/Norton, MA

July 12, 2017Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 12, 2017, 1:57 PM EDT for Capitol Planning Region, Northeastern Connecticut Planning Region, Connecticut. It was in force for 41 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 12, 2017, 1:57 PM EDT (17:57 UTC)
Expired: Jul 12, 2017, 2:38 PM EDT
In force: 41 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

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

The radar

The Boston radar (KBOX), 102 km from the middle of the area, began a volume at 18:01 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, 6.0 hours before the alert went out and 109 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: 529 J/kg
Mixed-layer CIN: -143 J/kg
Mixed-layer LCL: 1143 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 145 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

987 
WUUS51 KBOX 121757
SVRBOX
CTC003-013-015-121900-
/O.NEW.KBOX.SV.W.0046.170712T1757Z-170712T1900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Taunton MA
157 PM EDT WED JUL 12 2017

The National Weather Service in Taunton has issued a

* Severe Thunderstorm Warning for...
  West central Windham County in northern Connecticut...
  Tolland County in northern Connecticut...
  Northeastern Hartford County in northern Connecticut...

* Until 300 PM EDT

* At 156 PM EDT, a severe thunderstorm was located over East Windsor,
  or over South Windsor, moving east at 15 mph.

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

  SOURCE...Trained weather spotters. 

  IMPACT...Hail damage to vehicles is possible. Expect damage to 
           trees and power lines. 

* Locations impacted include...
  Manchester, East Hartford, Enfield, Glastonbury, Vernon, Mansfield,
  South Windsor, Windham, Willimantic, Ellington, Tolland, Coventry,
  East Windsor, Hebron, Lebanon, Willington, Columbia, Bolton,
  Ashford and Pomfret.

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 4196 7254 4189 7203 4170 7221 4171 7224
      4169 7227 4167 7227 4164 7233 4162 7233
      4179 7261
TIME...MOT...LOC 1756Z 287DEG 12KT 4188 7256 

HAIL...1.00IN
WIND...60MPH
 
$$

DUNTEN

2 follow-up statements

424 
WWUS51 KBOX 121820
SVSBOX

Severe Weather Statement
National Weather Service Taunton MA
220 PM EDT WED JUL 12 2017

CTC003-121830-
/O.CAN.KBOX.SV.W.0046.000000T0000Z-170712T1900Z/
Hartford CT-
220 PM EDT WED JUL 12 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN HARTFORD COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4195 7251 4195 7249 4189 7203 4170 7221
      4171 7224 4169 7227 4167 7227 4164 7233
      4162 7233 4170 7246 4181 7247 4181 7251
      4186 7250 4186 7252
TIME...MOT...LOC 1820Z 276DEG 16KT 4187 7242 

$$

CTC013-015-121900-
/O.CON.KBOX.SV.W.0046.000000T0000Z-170712T1900Z/
Windham CT-Tolland CT-
220 PM EDT WED JUL 12 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR WEST CENTRAL WINDHAM AND TOLLAND COUNTIES...

At 220 PM EDT, a severe thunderstorm was located over Vernon, moving
east at 20 mph.

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

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is possible. Expect damage to trees 
         and power lines. 

Locations impacted include...
Vernon, Mansfield, South Windsor, Windham, Willimantic, Ellington,
Tolland, Coventry, Hebron, Lebanon, Willington, Columbia, Bolton,
Ashford, Pomfret, Andover, Chaplin 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 4195 7251 4195 7249 4189 7203 4170 7221
      4171 7224 4169 7227 4167 7227 4164 7233
      4162 7233 4170 7246 4181 7247 4181 7251
      4186 7250 4186 7252
TIME...MOT...LOC 1820Z 276DEG 16KT 4187 7242 

HAIL...1.00IN
WIND...60MPH
 
$$

DUNTEN

726 
WWUS51 KBOX 121838
SVSBOX

Severe Weather Statement
National Weather Service Taunton MA
238 PM EDT WED JUL 12 2017

CTC013-015-121848-
/O.CAN.KBOX.SV.W.0046.000000T0000Z-170712T1900Z/
Windham CT-Tolland CT-
238 PM EDT WED JUL 12 2017

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL WINDHAM AND
TOLLAND 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 heavy rain is
still possible with this thunderstorm.

LAT...LON 4195 7251 4195 7249 4189 7203 4170 7221
      4171 7224 4169 7227 4167 7227 4164 7233
      4162 7233 4170 7246 4181 7247 4181 7251
      4186 7250 4186 7252
TIME...MOT...LOC 1836Z 287DEG 12KT 4185 7234 

$$

DUNTEN

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 10:15 AM EDT	Flash Flood Watch	BOX	Capitol Planning Region, Northeastern Connecticut Planning Region	11 hr
Jul 12, 12:53 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region	67 min
Jul 12, 1:07 PM EDT	Areal Flood Advisory	BOX	Capitol Planning Region	53 min
Jul 12, 1:22 PM EDT	Severe Thunderstorm Warning	BOX		38 min
Jul 12, 3:27 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	63 min
Jul 12, 3:47 PM EDT	Areal Flood Advisory	BOX	Northeastern Connecticut Planning Region	58 min
Jul 12, 4:26 PM EDT	Flash Flood Warning	BOX	Northeastern Connecticut Planning Region	2 hr
Jul 12, 5:01 PM EDT	Special Weather Statement	BOX		44 min
Jul 12, 5:19 PM EDT	Areal Flood Advisory	BOX	Northeastern Connecticut Planning Region	56 min
Jul 12, 5:21 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	35 min
Jul 12, 5:36 PM EDT	Flash Flood Warning	BOX	Northeastern Connecticut Planning Region	114 min
Jul 12, 5:43 PM EDT	Special Weather Statement	BOX		47 min

Nearby

Severe Thunderstorm Warnings in Connecticut, 2017 Every severe thunderstorm warning in 2017

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.