Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 49, NWS Boston/Norton, MA

July 20, 2019Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 20, 2019, 8:56 PM EDT for Worcester County, Massachusetts. It was in force for 18 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 20, 2019, 8:56 PM EDT (00:56 UTC)
Expired: Jul 20, 2019, 9:14 PM EDT
In force: 18 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Worcester County, MA

The radar

The Boston radar (KBOX), 46 km from the middle of the area, began a volume at 00:58 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

Chatham, MA (KCHH), launched 00:00Z, 0.9 hours before the alert went out and 148 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: 1179 J/kg
Mixed-layer CIN: -153 J/kg
Mixed-layer LCL: 1092 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -12 m²/s²
0-3 km storm-relative helicity: 3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

173 
WUUS51 KBOX 210056
SVRBOX
MAC027-210145-
/O.NEW.KBOX.SV.W.0049.190721T0056Z-190721T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
856 PM EDT Sat Jul 20 2019

The National Weather Service in Boston/Norton has issued a

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

* Until 945 PM EDT.

* At 855 PM EDT, a severe thunderstorm was located near Oxford, or 11
  miles south of Worcester, moving east at 25 mph.

  HAZARD...50 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...
  Milford, Grafton, Webster, Auburn, Northbridge, Oxford, Uxbridge,
  Millbury, Dudley, Blackstone, Sutton, Douglas, Upton, Hopedale,
  Mendon and Millville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4219 7152 4202 7150 4206 7191 4217 7190
      4218 7164 4218 7155 4219 7155
TIME...MOT...LOC 0055Z 276DEG 23KT 4210 7181 

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

BW

1 follow-up statement

590 
WWUS51 KBOX 210114
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
914 PM EDT Sat Jul 20 2019

MAC027-210123-
/O.CAN.KBOX.SV.W.0049.000000T0000Z-190721T0145Z/
Worcester MA-
914 PM EDT Sat Jul 20 2019

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WORCESTER COUNTY
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.

LAT...LON 4219 7152 4202 7150 4206 7191 4217 7190
      4218 7164 4218 7155 4219 7155
TIME...MOT...LOC 0109Z 276DEG 23KT 4209 7165 

$$

BW

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2019 Every severe thunderstorm warning in 2019

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.