Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 13, NWS Boston/Norton, MA

May 31, 2017Capitol Planning Region, Connecticut; Hampden County, Hampshire County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at May 31, 2017, 6:59 PM EDT for Capitol Planning Region, Connecticut; Hampden County, Hampshire County, Massachusetts. It was in force for 31 min. 5 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: May 31, 2017, 6:59 PM EDT (22:59 UTC)
Expired: May 31, 2017, 7:30 PM EDT
In force: 31 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Capitol Planning Region, CT, Hampden County, MA, Hampshire County, MA

The radar

The Albany radar (KENX), 108 km from the middle of the area, began a volume at 23:01 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.

What was reported inside it

Time	Report	Where	Remark
May 31, 7:00 PM EDT	HAIL 0.75	Montgomery, MA	HAIL COVERING THE GROUND
May 31, 7:22 PM EDT	HAIL 0.75	Granville, MA
May 31, 7:35 PM EDT	HAIL 0.88	Westfield, MA	0.5 TO 0.88 INCH HAIL
May 31, 7:39 PM EDT	HAIL 0.88	Southwick, MA
May 31, 7:39 PM EDT	HAIL 1	Westfield, MA	0.75 TO 1 INCH HAIL

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 31, 1:22 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 11.0 hours before the alert went out and 99 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: 1 J/kg
Mixed-layer CIN: -131 J/kg
Mixed-layer LCL: 690 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

893 
WUUS51 KBOX 312259
SVRBOX
CTC003-MAC013-015-312330-
/O.NEW.KBOX.SV.W.0013.170531T2259Z-170531T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Taunton MA
659 PM EDT WED MAY 31 2017

The National Weather Service in Taunton has issued a

* Severe Thunderstorm Warning for...
  Northwestern Hartford County in northern Connecticut...
  South central Hampshire County in western Massachusetts...
  Southwestern Hampden County in western Massachusetts...

* Until 730 PM EDT

* At 659 PM EDT, severe thunderstorms were located along a line
  extending from near Wendell to Easthampton to Ashley Falls, moving
  southeast at 15 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. Though numerous reports north across the 
           Connecticut River Valley in Massachusetts of dime to 
           nickel sized hail. 

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

* Locations impacted include...
  Springfield, Chicopee, Westfield, Holyoke, Agawam, West
  Springfield, Ludlow, South Hadley, Easthampton, Longmeadow,
  Suffield, East Longmeadow, Wilbraham, Granby, Southwick,
  Southampton, Huntington, Hartland, Russell and Westhampton.

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 these storms. 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.

&&

LAT...LON 4212 7306 4215 7307 4215 7303 4222 7301
      4228 7281 4217 7240 4208 7252 4194 7290
      4197 7289 4197 7303 4204 7301 4204 7306
      4211 7307
TIME...MOT...LOC 2259Z 300DEG 15KT 4251 7245 4227 7263 4207 7333 

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

Sipprell

The office that day

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

Issued	Product	Office	Counties	Lasted
May 31, 6:08 AM EDT	Dense Fog Advisory	BOX	Northeastern Connecticut Planning Region	4 hr
May 31, 7:28 PM EDT	Severe Thunderstorm Warning	BOX	Capitol Planning Region	43 min
May 31, 3:45 PM EDT	Special Weather Statement	BOX	Barnstable	60 min
May 31, 5:30 PM EDT	Special Weather Statement	BOX	Franklin, Hampden, Hampshire	60 min
May 31, 5:51 PM EDT	Severe Thunderstorm Warning	BOX	Franklin	24 min
May 31, 6:12 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire	33 min
May 31, 6:42 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire, Worcester	48 min
May 31, 6:44 PM EDT	Special Weather Statement	BOX	Franklin	46 min
May 31, 7:29 PM EDT	Special Weather Statement	BOX	Essex	46 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2017 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.