Alert archive / Massachusetts / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 73, NWS Boston/Norton, MA

July 23, 1998Middlesex County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 23, 1998, 1:09 PM EDT for Middlesex County, Massachusetts. It was in force for 46 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 23, 1998, 1:09 PM EDT (17:09 UTC)
Expired
Jul 23, 1998, 1:55 PM EDT
In force
46 min
Issued by
NWS Boston/Norton, MA
Area
Whole counties

County Middlesex County, MA

The radar

The Boston radar (KBOX), 63 km from the middle of the area, began a volume at 17:09 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

TimeReportWhereRemark
Jul 23, 1:12 PM EDTHail 0.75Acton, MA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

IssuedProductOfficeLasted
Jul 23, 12:45 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 5.2 hours before the alert went out and 148 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, Chatham, MA at 12:00Z on 1998-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Chatham, MA at 12:00Z on 1998-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1192 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
56 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.

910 
WUUS1 KBOS 231707 RRA
SVRBOS
MAC017-231755-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
109 PM EDT THU JUL 23 1998

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MIDDLESEX COUNTY IN NORTHEASTERN MASSACHUSETTS

* UNTIL 155 PM EDT

* AT 105 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 3 MILES NORTHEAST OF BOXBORO...MOVING
  NORTHEAST AT 30 MPH.

* TOWNS IN/NEAR THE PATH OF THIS STORM INCLUDE...
  ACTON AT 108 PM
  CARLISLE AT 115 PM
  CHELMSFORD AT 125 PM
  BILLERICA AT 125 PM

SEVERE THUNDERSTORMS PRODUCE LARGE HAIL AND/OR WINDS STRONG ENOUGH
TO KNOCK DOWN TREES AND POWER LINES.  MOVE INDOORS AND STAY AWAY
FROM WINDOWS.

TORRENTIAL DOWNPOURS WILL ALSO ACCOMPANY THIS STORM.

GAF/WD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 1:28 PM EDTSevere Thunderstorm WarningBOXHampden, Worcester32 min
Jul 23, 1:45 PM EDTTornado WarningBOXWorcester50 min
Jul 23, 2:01 PM EDTSevere Thunderstorm WarningBOXMiddlesex44 min
Jul 23, 2:06 PM EDTSevere Thunderstorm WarningBOXEssex49 min
Jul 23, 2:18 PM EDTSevere Thunderstorm WarningBOXNorfolk57 min
Jul 23, 2:27 PM EDTSevere Thunderstorm WarningBOXSuffolk48 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 1998Every severe thunderstorm warning in 1998

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.