Alert archive / Massachusetts / Tornado Warnings in 2026

Tornado Warning 1, NWS Boston/Norton, MA

June 18, 2026Middlesex County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this tornado warning at Jun 18, 2026, 5:23 PM EDT for Middlesex County, Worcester County, Massachusetts. It was in force for 31 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 18, 2026, 5:23 PM EDT (21:23 UTC)
Expired: Jun 18, 2026, 5:54 PM EDT
In force: 31 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Middlesex County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 73 km from the middle of the area, began a volume at 21:25 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 18, 1:45 PM EDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.4 hours before the alert went out and 182 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: 22 J/kg
Mixed-layer CIN: -101 J/kg
Mixed-layer LCL: 583 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 323 m²/s²
0-3 km storm-relative helicity: 384 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

563 
WFUS51 KBOX 182123
TORBOX
MAC017-027-182215-
/O.NEW.KBOX.TO.W.0001.260618T2123Z-260618T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Boston/Norton MA
523 PM EDT Thu Jun 18 2026

The National Weather Service in Boston/Norton has issued a

* Tornado Warning for...
  Central Worcester County in central Massachusetts...
  South central Middlesex County in northeastern Massachusetts...

* Until 615 PM EDT.

* At 523 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Paxton, or 9 miles west of Worcester, moving east
  at 35 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Worcester, Shrewsbury, Holden, Leicester, Rutland, Sterling, West 
  Boylston, Paxton, Boylston, and Princeton around 530 PM EDT.
  Grafton, Northborough, Clinton, and Millbury around 535 PM EDT.
  Westborough, Lancaster, and Berlin around 540 PM EDT.
  Marlborough, Hudson, Hopkinton, Southborough, and Upton around 545 
  PM EDT.
  Bolton around 550 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4226 7204 4238 7210 4251 7162 4221 7152
TIME...MOT...LOC 2123Z 267DEG 29KT 4230 7199 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

BW

1 follow-up statement

888 
WWUS51 KBOX 182154
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
554 PM EDT Thu Jun 18 2026

MAC017-027-182204-
/O.CAN.KBOX.TO.W.0001.000000T0000Z-260618T2215Z/
Worcester MA-Middlesex MA-
554 PM EDT Thu Jun 18 2026

...THE TORNADO WARNING FOR CENTRAL WORCESTER AND SOUTH CENTRAL
MIDDLESEX COUNTIES IS CANCELLED...

The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 700 PM EDT for central and
northeastern Massachusetts.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Boston/Norton.

LAT...LON 4226 7204 4238 7210 4251 7162 4221 7152
TIME...MOT...LOC 2154Z 267DEG 29KT 4231 7165 

$$

CB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 18, 2:22 AM EDT	Gale Warning	BOX		20 hr
Jun 18, 3:00 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampshire	60 min
Jun 18, 4:05 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Middlesex, Worcester	55 min
Jun 18, 5:30 PM EDT	Tornado Warning	BOX	Hampden, Hampshire, Worcester	26 min
Jun 18, 5:55 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Norfolk, Worcester	21 min

Nearby

Tornado Warnings in Massachusetts, 2026 Every tornado warning in 2026 Tornadoes in 2026

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.