Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 18, NWS Boston/Norton, MA

June 15, 2021Essex County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 15, 2021, 5:28 PM EDT for Essex County, Massachusetts. It was in force for 32 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 15, 2021, 5:28 PM EDT (21:28 UTC)
Expired: Jun 15, 2021, 6:00 PM EDT
In force: 32 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

County Essex County, MA

The radar

The Boston radar (KBOX), 99 km from the middle of the area, began a volume at 21:29 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 15, 5:45 PM EDT	HAIL 0.5	Newburyport, MA	HAIL REPORTED BY COCORAHS OBSERVER
Jun 15, 5:45 PM EDT	HAIL 1.25	Newburyport, MA	COCORAHS OBSERVER

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

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 9.5 hours before the alert went out and 129 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 659 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: 126 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

502 
WUUS51 KBOX 152128
SVRBOX
MAC009-152200-
/O.NEW.KBOX.SV.W.0018.210615T2128Z-210615T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
528 PM EDT Tue Jun 15 2021

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  North central Essex County in northeastern Massachusetts...

* Until 600 PM EDT.

* At 528 PM EDT, a severe thunderstorm was located over Merrimac, or
  near Haverhill, moving east at 25 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Haverhill, Newburyport, Amesbury, Salisbury, Newbury, Groveland,
  Merrimac and West Newbury.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4286 7085 4287 7082 4283 7081 4281 7087
      4280 7083 4282 7082 4276 7080 4277 7082
      4276 7082 4278 7107 4281 7107 4286 7103
      4289 7093 4289 7090
TIME...MOT...LOC 2128Z 269DEG 20KT 4282 7099 

HAIL...0.88IN
WIND...60MPH
 
$$

KJC

1 follow-up statement

179 
WWUS51 KBOX 152201
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
601 PM EDT Tue Jun 15 2021

MAC009-152211-
/O.EXP.KBOX.SV.W.0018.000000T0000Z-210615T2200Z/
Essex MA-
601 PM EDT Tue Jun 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL ESSEX COUNTY HAS
EXPIRED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been allowed to expire.

LAT...LON 4286 7085 4287 7082 4283 7081 4281 7087
      4280 7083 4282 7082 4276 7080 4277 7082
      4276 7082 4278 7107 4281 7107 4286 7103
      4289 7093 4289 7090
TIME...MOT...LOC 2201Z 269DEG 20KT 4282 7076 

$$

KJC

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 15, 5:13 PM EDT	Severe Thunderstorm Warning	BOX	Essex	62 min
Jun 15, 5:32 PM EDT	Special Marine Warning	BOX		58 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.