Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 48, NWS Boston/Norton, MA

August 20, 2004Middlesex County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Aug 20, 2004, 8:31 PM EDT for Middlesex County, Massachusetts. It was in force for 29 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, 8:31 PM EDT (00:31 UTC)
Expired
Aug 20, 2004, 9:00 PM EDT
In force
29 min
Issued by
NWS Boston/Norton, MA
Area
Counties, with a storm outline in the text

County Middlesex County, MA

The radar

The Boston radar (KBOX), 102 km from the middle of the area, began a volume at 00:33 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.

IssuedProductOfficeLasted
Aug 20, 6:10 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 0.5 hours before the alert went out and 151 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-pSkew-T log-p diagram, Albany, NY at 00:00Z on 2004-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 78 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 00:00Z on 2004-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
78 J/kg
Mixed-layer CIN
-102 J/kg
Mixed-layer LCL
1074 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
78 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KBOX 210031
SVRBOX
MAC017-210100-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
831 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   

* UNTIL 900 PM EDT

* AT 824 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS
  STORM WAS LOCATED NEAR ROYALSTON...OR ABOUT 15 MILES SOUTHWEST OF
  JAFFREY...AND MOVING EAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  GARDNER BY 845 PM EDT
  WESTMINSTER AND ASHBURNHAM BY 850 PM EDT
  FITCHBURG AND 7 MILES SOUTH OF ASHBY BY 855 PM EDT
  LUNENBURG...LEOMINSTER...8 MILES SOUTHWEST OF TOWNSEND AND 8 MILES
  WEST OF SHIRLEY BY 900 PM EDT

LAT...LON 4272 7221 4254 7225 4245 7166 4267 7161

$$

STRAUSS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 3:05 AM EDTSevere Thunderstorm WarningBOXWorcester40 min
Aug 21, 4:36 AM EDTSpecial Marine WarningBOX54 min
Aug 21, 3:22 PM EDTSpecial Marine WarningBOX83 min
Aug 21, 3:22 PM EDTSpecial Marine WarningBOX83 min
Aug 21, 4:08 PM EDTSpecial Marine WarningBOX67 min
Aug 21, 4:08 PM EDTSpecial Marine WarningBOX67 min
Aug 21, 4:12 PM EDTSevere Thunderstorm WarningBOXNorfolk, Plymouth, Suffolk33 min
Aug 21, 4:37 PM EDTSpecial Marine WarningBOX53 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2004Every 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.