Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 41, NWS Boston/Norton, MA

June 30, 2021Norfolk County, Plymouth County, Suffolk County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 30, 2021, 8:14 PM EDT for Norfolk County, Plymouth County, Suffolk County, Massachusetts. It was in force for 46 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: Jun 30, 2021, 8:14 PM EDT (00:14 UTC)
Expired: Jun 30, 2021, 9:00 PM EDT
In force: 46 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Norfolk County, MA, Plymouth County, MA, Suffolk County, MA

The radar

The Boston radar (KBOX), 37 km from the middle of the area, began a volume at 00:15 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
Jun 30, 3:21 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Gray, ME (KGYX), launched 00:00Z, 0.2 hours before the alert went out and 192 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: 505 J/kg
Mixed-layer CIN: -92 J/kg
Mixed-layer LCL: 1353 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 125 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted.

031 
WUUS51 KBOX 010014
SVRBOX
MAC021-023-025-010100-
/O.NEW.KBOX.SV.W.0041.210701T0014Z-210701T0100Z/

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

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  South central Suffolk County in eastern Massachusetts...
  Northeastern Norfolk County in eastern Massachusetts...
  Northwestern Plymouth County in southeastern Massachusetts...

* Until 900 PM EDT.

* At 814 PM EDT, a severe thunderstorm was located over Rockland, or
  near Weymouth, moving east at 25 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect wind damage to trees and power lines. Minor hail 
           damage to vehicles is possible.

* Locations impacted include...
  Boston, Quincy, Weymouth, Braintree, Randolph, Milton, Marshfield,
  Hingham, Scituate, Rockland, Abington, Hanover, Holbrook, Norwell,
  Hull and Cohasset.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4212 7098 4228 7109 4226 7097 4229 7094
      4225 7096 4227 7093 4225 7088 4230 7088
      4226 7086 4225 7077 4220 7072 4221 7071
      4220 7071 4217 7073 4212 7068
TIME...MOT...LOC 0014Z 266DEG 22KT 4217 7091 

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

Frank

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 8:08 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Norfolk, Worcester	67 min
Jun 30, 8:16 PM EDT	Special Marine Warning	BOX		59 min
Jun 30, 8:31 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Norfolk, Plymouth	59 min
Jun 30, 8:41 PM EDT	Special Marine Warning	BOX		64 min
Jun 30, 8:57 PM EDT	Special Marine Warning	BOX		63 min
Jun 30, 9:54 PM EDT	Special Marine Warning	BOX		66 min
Jul 1, 4:01 PM EDT	Special Weather Statement	BOX	Bristol, Plymouth	59 min
Jul 1, 4:02 PM EDT	Small Craft Advisory	BOX		4 days
Jul 1, 4:29 PM EDT	Special Marine Warning	BOX		61 min
Jul 1, 5:03 PM EDT	Special Weather Statement	BOX	Barnstable	42 min
Jul 1, 5:21 PM EDT	Special Marine Warning	BOX		54 min
Jul 1, 7:05 PM EDT	Special Weather Statement	BOX	Hampden	55 min
Jul 1, 7:59 PM EDT	Areal Flood Warning	BOX	Hampden, Hampshire	3 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.