Alert archive / Massachusetts / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 13, NWS Boston/Norton, MA

July 30, 1986Nantucket County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 30, 1986, 12:30 AM EDT for Nantucket County, Massachusetts. It was in force for 30 min.

The area

The counties it named.

The facts

Issued
Jul 30, 1986, 12:30 AM EDT (04:30 UTC)
Expired
Jul 30, 1986, 1:00 AM EDT
In force
30 min
Issued by
NWS Boston/Norton, MA
Area
Whole counties

County Nantucket County, MA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Chatham, MA (KCHH), launched 00:00Z, 4.5 hours before the alert went out and 45 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 1986-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 373 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 1986-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 70 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
373 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
552 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
70 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBOS 300345
SVRBOS
MAC007-019-300500-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BOSTON MA
1130 PM EDT TUE JUL 29 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 100 AM EDT WED FOR PEOPLE IN THE FOLLOWING
COUNTIES OF

SOUTHEAST MASSACHUSETTS...DUKES...NANTUCKET

AT 1130 PM EDT NATIONAL WEATHER SERVICE RADAR SHOWED A CLUSTER OF
HEAVY THUNDERSTORMS OVER VINEYARD SOUND APPROACHING MARTHAS VINEYARD
ISLAND.  MOVEMENT WAS EAST AT 15 MPH.

THESE STORMS ARE ACCOMPANIED BY WIND GUSTS TO 50 MPH..TORRENTIAL
DOWNPOURS..AND POSSIBLE HAIL.

IF YOU ARE IN THE PATH OF THESE STORMS MOVE TO A SAFE SHELTER QUICKLY.
ASK THE NEAREST LAW ENFORCEMENT AGENCY TO RELAY ANY REPORTS OF
SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE.

AUCIELLO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 12:30 AM EDTSevere Thunderstorm WarningBOXDukes30 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 1986Every severe thunderstorm warning in 1986

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.