Alert archive / Massachusetts / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 21, NWS Boston/Norton, MA

July 6, 1999Plymouth County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 6, 1999, 10:23 PM EDT for Plymouth County, Massachusetts. It was in force for 52 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 6, 1999, 10:23 PM EDT (02:23 UTC)
Expired
Jul 6, 1999, 11:15 PM EDT
In force
52 min
Issued by
NWS Boston/Norton, MA
Area
Whole counties

County Plymouth County, MA

What was reported inside it

TimeReportWhereRemark
Jul 6, 10:45 PM EDTThunderstorm Wind 60Hingham, 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 nearest sounding before it

Chatham, MA (KCHH), launched 00:00Z, 2.4 hours before the alert went out and 73 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 00:00Z on 1999-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1046 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 00:00Z on 1999-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 67 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
1046 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
1453 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBOX 070225 RRA
SVRBOS
MAC023-070315-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
1023 PM EDT TUE JUL 6 1999

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN PLYMOUTH COUNTY IN MASSACHUSETTS
  INCLUDING BROCKTON

* UNTIL 1115 PM EDT.

* AT 1020 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER NORFOLK COUNTY BETWEEN SHARON AND
  FOXBORO...MOVING EAST AT 40 MPH.  THESE STORMS HAVE A HISTORY OF
  PRODUCING DAMAGING WIND GUSTS.

* OTHER LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE WHITMAN...
  SCITUATE...ROCKLAND...PEMBROKE...NORWELL...HINGHAM...AND ABINGTON.

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

IN ADDITION TO LARGE HAIL AND DAMAGING WIND...VERY FREQUENT
CLOUD-TO-GROUND LIGHTNING IS ALSO LIKELY WITH THIS STORM. GET \AWAY
FROM OPEN FIELDS...BODIES OF WATER...AND TALL OBJECTS.
$$

JWD/FIELD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 10:12 PM EDTSevere Thunderstorm WarningBOXNorfolk33 min
Jul 6, 11:05 PM EDTSevere Thunderstorm WarningBOXBarnstable55 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 1999Every severe thunderstorm warning in 1999

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.