Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 34, NWS Boston/Norton, MA

June 30, 2021Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 30, 2021, 5:29 PM EDT for Worcester County, Massachusetts. It was in force for 44 min. 2 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: Jun 30, 2021, 5:29 PM EDT (21:29 UTC)
Expired: Jun 30, 2021, 6:13 PM EDT
In force: 44 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Worcester County, MA

The radar

The Boston radar (KBOX), 56 km from the middle of the area, began a volume at 21:27 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
Jun 30, 5:30 PM EDT	TSTM WND DMG	Oakham, MA	LARGE TREE DOWN NORTH BROOKFIELD ROAD
Jun 30, 5:42 PM EDT	TSTM WND DMG	Leicester, MA	LARGE TREE DOWN ON WIRES ON SIANAI STREET

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
Jun 30, 3:21 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 9.5 hours before the alert went out and 186 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: 113 J/kg
Mixed-layer CIN: -257 J/kg
Mixed-layer LCL: 1162 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 66 m²/s²
0-3 km storm-relative helicity: 98 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

319 
WUUS51 KBOX 302129
SVRBOX
MAC027-302230-
/O.NEW.KBOX.SV.W.0034.210630T2129Z-210630T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
529 PM EDT Wed Jun 30 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Central Worcester County in central Massachusetts...

* Until 630 PM EDT.

* At 528 PM EDT, a severe thunderstorm was located over Oakham, or 10
  miles west of Worcester, moving east at 25 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Worcester, Framingham, Marlborough, Shrewsbury, Milford, Hudson,
  Westborough, Grafton, Holden, Auburn, Hopkinton, Northborough,
  Clinton, Millbury, Spencer, Leicester, Southborough, Rutland,
  Sterling and West Boylston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4241 7158 4240 7160 4239 7158 4235 7163
      4232 7160 4233 7149 4231 7148 4227 7151
      4227 7156 4226 7159 4221 7160 4219 7156
      4219 7150 4218 7150 4224 7215 4244 7213
TIME...MOT...LOC 2128Z 277DEG 19KT 4233 7201 

HAIL...0.75IN
WIND...60MPH
 
$$

Frank

3 follow-up statements

037 
WWUS51 KBOX 302146
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
546 PM EDT Wed Jun 30 2021

MAC027-302230-
/O.CON.KBOX.SV.W.0034.000000T0000Z-210630T2230Z/
Worcester MA-
546 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR EAST CENTRAL WORCESTER COUNTY...

At 545 PM EDT, a severe thunderstorm was located over Holden, or near
Worcester, moving east at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Worcester, Framingham, Marlborough, Shrewsbury, Milford, Hudson,
Westborough, Grafton, Holden, Auburn, Hopkinton, Northborough,
Clinton, Millbury, Spencer, Leicester, Southborough, Rutland,
Sterling and West Boylston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4241 7158 4240 7160 4239 7158 4235 7163
      4232 7160 4233 7149 4231 7148 4227 7151
      4227 7156 4226 7159 4221 7160 4220 7157
      4219 7150 4218 7150 4225 7197 4243 7200
TIME...MOT...LOC 2145Z 277DEG 19KT 4232 7188 

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

Frank

418 
WWUS51 KBOX 302201
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
601 PM EDT Wed Jun 30 2021

MAC027-302230-
/O.CON.KBOX.SV.W.0034.000000T0000Z-210630T2230Z/
Worcester MA-
601 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR EAST CENTRAL WORCESTER COUNTY...

At 601 PM EDT, a severe thunderstorm was located over Boylston, or
near Shrewsbury, moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Framingham, Marlborough, Shrewsbury, Hudson, Westborough,
Northborough, Clinton, Southborough, Sterling, West Boylston, Bolton,
Boylston and Berlin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4241 7158 4240 7160 4239 7158 4235 7163
      4232 7160 4233 7149 4231 7148 4227 7151
      4227 7156 4226 7159 4226 7161 4227 7164
      4227 7175 4242 7177
TIME...MOT...LOC 2201Z 254DEG 30KT 4235 7170 

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

Frank

477 
WWUS51 KBOX 302213
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
613 PM EDT Wed Jun 30 2021

MAC027-302223-
/O.CAN.KBOX.SV.W.0034.000000T0000Z-210630T2230Z/
Worcester MA-
613 PM EDT Wed Jun 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL WORCESTER COUNTY
IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
central and northeastern Massachusetts.

LAT...LON 4241 7158 4240 7160 4239 7158 4235 7163
      4232 7160 4233 7149 4231 7148 4227 7151
      4227 7156 4226 7159 4226 7161 4227 7164
      4227 7175 4242 7177
TIME...MOT...LOC 2212Z 277DEG 19KT 4234 7161 

$$

Frank

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 2:29 AM EDT	Small Craft Advisory	BOX		18 hr
Jun 30, 3:40 PM EDT	Special Weather Statement	BOX	Hampshire	65 min
Jun 30, 3:42 PM EDT	Special Weather Statement	BOX	Franklin	63 min
Jun 30, 3:48 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire	57 min
Jun 30, 4:03 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampshire	57 min
Jun 30, 4:32 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Middlesex, Worcester	58 min
Jun 30, 4:39 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire, Worcester	66 min
Jun 30, 4:45 PM EDT	Tornado Warning	BOX	Franklin, Worcester	26 min
Jun 30, 5:00 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	30 min
Jun 30, 5:13 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	62 min
Jun 30, 5:25 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	49 min
Jun 30, 5:26 PM EDT	Special Marine Warning	BOX		64 min
Jun 30, 5:43 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	51 min
Jun 30, 5:54 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Norfolk, Suffolk, Worcester	53 min
Jun 30, 5:58 PM EDT	Special Marine Warning	BOX		62 min
Jun 30, 6:11 PM EDT	Special Weather Statement	BOX	Norfolk	49 min
Jun 30, 6:12 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Norfolk, Plymouth, Suffolk, Worcester	47 min
Jun 30, 6:22 PM EDT	Special Marine Warning	BOX		53 min
Jun 30, 6:31 PM EDT	Special Marine Warning	BOX		59 min
Jun 30, 6:45 PM EDT	Severe Thunderstorm Warning	BOX	Hampden	60 min
Jun 30, 6:57 PM EDT	Special Marine Warning	BOX		33 min
Jun 30, 7:15 PM EDT	Severe Thunderstorm Warning	BOX	Hampden, Worcester	60 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.