Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 68, NWS Boston/Norton, MA

August 5, 2017Franklin County, Hampden County, Hampshire County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Aug 5, 2017, 3:01 PM EDT for Franklin County, Hampden County, Hampshire County, Massachusetts. It was in force for 44 min. 4 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: Aug 5, 2017, 3:01 PM EDT (19:01 UTC)
Expired: Aug 5, 2017, 3:45 PM EDT
In force: 44 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Franklin County, MA, Hampden County, MA, Hampshire County, MA

The radar

The Albany radar (KENX), 124 km from the middle of the area, began a volume at 19:01 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
Aug 5, 3:01 PM EDT	TSTM WND DMG	Northampton, MA	LARGE TREE DOWN ON I91 NORTHBOUND BY EXIT 19 AT MILE MARKER 25
Aug 5, 3:02 PM EDT	TSTM WND DMG	Northampton, MA	LARGE PPINE TREE DOWN ON ELM STREET
Aug 5, 3:02 PM EDT	TSTM WND DMG	Northampton, MA	TREES DOWN ON WOODLAWN AVENUE
Aug 5, 3:10 PM EDT	TSTM WND DMG	Northampton, MA	TREE DOWN BLOCKING JACKSON STREET BIKE PATH

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

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 7.0 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: 478 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 590 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 202 m²/s²
0-3 km storm-relative helicity: 219 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted.

423 
WUUS51 KBOX 051901
SVRBOX
MAC011-013-015-051945-
/O.NEW.KBOX.SV.W.0068.170805T1901Z-170805T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Taunton MA
301 PM EDT SAT AUG 5 2017

The National Weather Service in Taunton has issued a

* Severe Thunderstorm Warning for...
  Central Hampshire County in western Massachusetts...
  East central Franklin County in western Massachusetts...
  North central Hampden County in western Massachusetts...

* Until 345 PM EDT

* At 300 PM EDT, a severe thunderstorm was located over Hadley, or
  near Northampton, moving northeast at 30 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...
  Holyoke, Amherst, Northampton, Deerfield, South Hadley,
  Easthampton, Belchertown, Montague, Granby, Southampton, Hadley,
  Sunderland, Hatfield, Williamsburg, Leverett, Shutesbury,
  Westhampton, Whately, Pelham and New Salem.

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 4221 7263 4223 7280 4252 7258 4246 7231
TIME...MOT...LOC 1900Z 224DEG 26KT 4235 7261 

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

Frank

2 follow-up statements

608 
WWUS51 KBOX 051935
SVSBOX

Severe Weather Statement
National Weather Service Taunton MA
335 PM EDT SAT AUG 5 2017

MAC011-013-015-051945-
/O.CON.KBOX.SV.W.0068.000000T0000Z-170805T1945Z/
Hampshire MA-Franklin MA-Hampden MA-
335 PM EDT SAT AUG 5 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR CENTRAL HAMPSHIRE...EAST CENTRAL FRANKLIN AND NORTHERN HAMPDEN
COUNTIES...

At 334 PM EDT, a severe thunderstorm was located over Hadley, or over
Amherst, moving northeast at 30 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Trained weather spotters reported a few trees down along 
         with large limbs in Northampton.

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

Locations impacted include...
Holyoke, Amherst, Northampton, Deerfield, South Hadley, Easthampton,
Belchertown, Granby, Hadley, Sunderland, Hatfield, Leverett,
Shutesbury, Whately, Pelham and New Salem.

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 4226 7257 4231 7271 4245 7261 4251 7255
      4246 7231
TIME...MOT...LOC 1934Z 226DEG 27KT 4238 7256 

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

Frank

578 
WWUS51 KBOX 051942
SVSBOX

Severe Weather Statement
National Weather Service Taunton MA
342 PM EDT SAT AUG 5 2017

MAC011-013-015-051952-
/O.EXP.KBOX.SV.W.0068.000000T0000Z-170805T1945Z/
Hampshire MA-Franklin MA-Hampden MA-
342 PM EDT SAT AUG 5 2017

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL HAMPSHIRE...EAST
CENTRAL FRANKLIN AND NORTHERN HAMPDEN COUNTIES WILL EXPIRE AT 345 PM
EDT...
                
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 will be allowed to expire.  However heavy rain
is still possible with this thunderstorm.

LAT...LON 4226 7257 4231 7271 4245 7261 4251 7255
      4246 7231
TIME...MOT...LOC 1942Z 224DEG 26KT 4238 7256 

$$

Frank

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 4, 8:42 PM EDT	Dense Fog Advisory	BOX	Barnstable, Dukes, Nantucket	13 hr
Aug 5, 3:37 AM EDT	Small Craft Advisory	BOX		36 hr
Aug 5, 8:49 AM EDT	Areal Flood Advisory	BOX	Hampden, Hampshire, Worcester	116 min
Aug 5, 9:39 AM EDT	Areal Flood Advisory	BOX	Worcester	2 hr
Aug 5, 1:04 PM EDT	Areal Flood Advisory	BOX	Franklin, Hampden, Hampshire, Worcester	56 min
Aug 5, 2:45 PM EDT	Special Weather Statement	BOX	Hampshire	45 min
Aug 5, 3:04 PM EDT	Areal Flood Warning	BOX	Hampden, Hampshire	116 min
Aug 5, 3:22 PM EDT	Special Weather Statement	BOX	Franklin	38 min
Aug 5, 3:38 PM EDT	Severe Thunderstorm Warning	BOX	Franklin	10 min
Aug 5, 4:17 PM EDT	Special Weather Statement	BOX	Worcester	43 min
Aug 5, 4:32 PM EDT	Special Weather Statement	BOX	Worcester	43 min
Aug 5, 4:56 PM EDT	Special Weather Statement	BOX	Worcester	34 min
Aug 5, 7:27 PM EDT	Special Weather Statement	BOX	Worcester	48 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.