Alert archive / Massachusetts / Tornado Warnings in 2023

Tornado Warning 4, NWS Boston/Norton, MA

July 21, 2023Worcester County, Massachusetts

NWS Boston/Norton, MA issued this tornado warning at Jul 21, 2023, 4:24 PM EDT for Worcester County, Massachusetts. It was in force for 17 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 21, 2023, 4:24 PM EDT (20:24 UTC)
Expired: Jul 21, 2023, 4:41 PM EDT
In force: 17 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Worcester County, MA

The radar

The Boston radar (KBOX), 101 km from the middle of the area, began a volume at 20:24 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
Jul 21, 1:02 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.4 hours before the alert went out and 185 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: 343 J/kg
Mixed-layer CIN: -60 J/kg
Mixed-layer LCL: 836 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 88 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

538 
WFUS51 KBOX 212024
TORBOX
MAC027-212100-
/O.NEW.KBOX.TO.W.0004.230721T2024Z-230721T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Boston/Norton MA
424 PM EDT Fri Jul 21 2023

The National Weather Service in Boston/Norton has issued a

* Tornado Warning for...
  Northwestern Worcester County in central Massachusetts...

* Until 500 PM EDT.
    
* At 424 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Petersham, or 12 miles south of Orange, moving
  northeast at 20 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...
  Templeton, Barre, Hubbardston, Hardwick, Phillipston and Petersham 
  around 430 PM EDT.
  Rutland around 440 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 4240 7226 4243 7229 4258 7209 4242 7198
TIME...MOT...LOC 2024Z 245DEG 18KT 4243 7225 

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

$$

KP

2 follow-up statements

541 
WWUS51 KBOX 212036
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
436 PM EDT Fri Jul 21 2023

MAC027-212100-
/O.CON.KBOX.TO.W.0004.000000T0000Z-230721T2100Z/
Worcester MA-
436 PM EDT Fri Jul 21 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM EDT FOR
NORTHWESTERN WORCESTER COUNTY...
    
At 436 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Petersham, or 12 miles southeast of Orange, moving
northeast at 20 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...
  Templeton, Rutland, Barre, Hubbardston, Phillipston and Petersham 
  around 440 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 4242 7218 4246 7222 4258 7209 4242 7198
TIME...MOT...LOC 2036Z 245DEG 18KT 4246 7218 

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

$$

KP

812 
WWUS51 KBOX 212041
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
441 PM EDT Fri Jul 21 2023

MAC027-212051-
/O.CAN.KBOX.TO.W.0004.000000T0000Z-230721T2100Z/
Worcester MA-
441 PM EDT Fri Jul 21 2023

...THE TORNADO WARNING FOR NORTHWESTERN WORCESTER COUNTY 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.  However gusty winds and
heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
central Massachusetts.

LAT...LON 4242 7218 4246 7222 4258 7209 4242 7198
TIME...MOT...LOC 2039Z 245DEG 18KT 4247 7215 

$$

KP

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 12:56 PM EDT	Special Weather Statement	BOX	Franklin	64 min
Jul 21, 1:55 PM EDT	Special Weather Statement	BOX	Hampden	65 min
Jul 21, 2:03 PM EDT	Flash Flood Warning	BOX	Franklin, Hampshire	3 hr
Jul 21, 2:06 PM EDT	Special Weather Statement	BOX	Franklin	54 min
Jul 21, 2:59 PM EDT	Special Weather Statement	BOX	Franklin	61 min
Jul 21, 3:02 PM EDT	Flash Flood Warning	BOX	Franklin, Worcester	5 hr
Jul 21, 3:50 PM EDT	Special Weather Statement	BOX	Worcester	55 min
Jul 21, 4:18 PM EDT	Special Weather Statement	BOX	Middlesex	57 min
Jul 21, 4:25 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	27 min
Jul 21, 4:47 PM EDT	Special Weather Statement	BOX	Middlesex	58 min
Jul 21, 4:49 PM EDT	Flash Flood Warning	BOX	Middlesex, Worcester	3 hr
Jul 21, 4:58 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	43 min
Jul 21, 5:01 PM EDT	Special Weather Statement	BOX	Worcester	59 min
Jul 21, 5:07 PM EDT	Areal Flood Warning	BOX	Franklin, Hampshire	57 min
Jul 21, 5:46 PM EDT	Special Weather Statement	BOX	Middlesex	59 min
Jul 21, 6:04 PM EDT	Flash Flood Warning Considerable damage threat	BOX	Franklin, Hampshire	2 hr
Jul 21, 6:16 PM EDT	Special Weather Statement	BOX	Franklin	59 min
Jul 21, 6:22 PM EDT	Flash Flood Warning	BOX	Essex, Middlesex, Worcester	3 hr
Jul 21, 6:32 PM EDT	Severe Thunderstorm Warning	BOX	Worcester	39 min
Jul 21, 7:22 PM EDT	Special Weather Statement	BOX	Middlesex	53 min
Jul 21, 7:54 PM EDT	Areal Flood Warning	BOX	Franklin, Worcester	111 min

Nearby

Tornado Warnings in Massachusetts, 2023 Every tornado warning in 2023 Tornadoes in 2023

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.