Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 40, NWS Boston/Norton, MA

August 20, 2004Middlesex County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Aug 20, 2004, 2:58 PM EDT for Middlesex County, Worcester County, Massachusetts. It was in force for 47 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: Aug 20, 2004, 2:58 PM EDT (18:58 UTC)
Expired: Aug 20, 2004, 3:45 PM EDT
In force: 47 min
Issued by: NWS Boston/Norton, MA
Area: Counties, with a storm outline in the text

Counties Middlesex County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 112 km from the middle of the area, began a volume at 18:58 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 20, 1:05 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 7.0 hours before the alert went out and 137 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: 244 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 569 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 77 m²/s²
0-3 km storm-relative helicity: 142 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS51 KBOX 201858
SVRBOX
MAC017-027-201945-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
257 PM EDT FRI AUG 20 2004

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN WORCESTER COUNTY IN CENTRAL MASSACHUSETTS
  THIS INCLUDES THE CITIES OF...LEOMINSTER...FITCHBURG
  EXTREME NORTHWESTERN MIDDLESEX COUNTY IN EASTERN MASSACHUSETTS

* UNTIL 345 PM EDT

* AT 254 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
NEW SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED NEAR ATHOL...OR 
ABOUT 16 MILES EAST OF GREENFIELD...AND MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ROYALSTON BY 305 PM EDT
  PHILLIPSTON BY 310 PM EDT
  TEMPLETON BY 320 PM EDT
  WINCHENDON BY 325 PM EDT
  GARDNER BY 330 PM EDT
  ASHBURNHAM AND WESTMINSTER BY 340 PM EDT

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

LAT...LON 4271 7214 4270 7172 4251 7171 4252 7225
      4254 7227 4258 7227 4257 7226 4261 7225
      4262 7222 4265 7222 4268 7227 4271 7227

$$

BELK/DUNHAM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 1:59 PM EDT	Severe Thunderstorm Warning	BOX	Worcester	31 min
Aug 20, 2:07 PM EDT	Tornado Warning	BOX	Worcester	23 min
Aug 20, 2:28 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	32 min
Aug 20, 3:25 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	50 min
Aug 20, 3:51 PM EDT	Special Marine Warning	BOX		84 min
Aug 20, 4:29 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	46 min
Aug 20, 4:33 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampshire	27 min
Aug 20, 5:27 PM EDT	Special Marine Warning	BOX		48 min
Aug 20, 6:03 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	42 min
Aug 20, 6:41 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Norfolk, Suffolk	49 min
Aug 20, 6:46 PM EDT	Special Marine Warning	BOX		89 min
Aug 20, 6:46 PM EDT	Special Marine Warning	BOX		89 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2004 Every severe thunderstorm warning in 2004

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.