Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 71, NWS Boston/Norton, MA

August 22, 20175 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Aug 22, 2017, 11:33 PM EDT for 5 counties in Massachusetts. It was in force for 57 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: Aug 22, 2017, 11:33 PM EDT (03:33 UTC)
Expired: Aug 23, 2017, 12:30 AM EDT
In force: 57 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 96 km from the middle of the area, began a volume at 03:33 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 watch it was issued in

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

Issued	Product	Office	Lasted
Aug 22, 3:55 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 3.6 hours before the alert went out and 150 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: 412 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1561 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 258 m²/s²
0-3 km storm-relative helicity: 444 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 8.2

Open this sounding in Storm Lab

The text

As transmitted.

784 
WUUS51 KBOX 230333
SVRBOX
MAC011-013-015-017-027-230430-
/O.NEW.KBOX.SV.W.0071.170823T0333Z-170823T0430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Taunton MA
1133 PM EDT TUE AUG 22 2017

The National Weather Service in Taunton has issued a

* Severe Thunderstorm Warning for...
  Northwestern Worcester County in central Massachusetts...
  Southeastern Hampshire County in western Massachusetts...
  Northwestern Middlesex County in northeastern Massachusetts...
  Southeastern Franklin County in western Massachusetts...
  North central Hampden County in western Massachusetts...

* Until 1230 AM EDT

* At 1132 PM EDT, severe thunderstorms were located along a line
  extending from near Rindge to Granby, moving east at 35 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to trees and power lines along with 
           torrential downpours and possibly localized flooding.

* Locations impacted include...
  Leominster, Fitchburg, Holyoke, Amherst, Northampton, Orange,
  Gardner, South Hadley, Holden, Easthampton, Belchertown, Spencer,
  Athol, Pepperell, Groton, Winchendon, Lunenburg, Ware, Townsend and
  Templeton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4270 7156 4230 7197 4221 7277 4272 7221
TIME...MOT...LOC 0332Z 248DEG 31KT 4272 7200 4225 7252 

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

Nocera

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 9:56 PM EDT	Special Weather Statement	BOX	Franklin	34 min
Aug 22, 10:08 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire	55 min
Aug 22, 11:09 PM EDT	Special Weather Statement	BOX	Franklin	66 min
Aug 22, 11:47 PM EDT	Special Weather Statement	BOX	Hampden	43 min
Aug 23, 12:40 AM EDT	Special Weather Statement	BOX	Middlesex	35 min
Aug 23, 2:11 AM EDT	Special Weather Statement	BOX	Middlesex	34 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 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.