Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 99, NWS Boston/Norton, MA

September 7, 20124 counties in Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Sep 7, 2012, 5:59 PM EDT for 4 counties in Massachusetts. It was in force for 46 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 7, 2012, 5:59 PM EDT (21:59 UTC)
Expired
Sep 7, 2012, 6:45 PM EDT
In force
46 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon

Counties Essex County, MA, Middlesex County, MA, Norfolk County, MA, Suffolk County, MA

The radar

The Boston radar (KBOX), 50 km from the middle of the area, began a volume at 22:01 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
Sep 7, 6:14 PM EDTTSTM WND DMGConcord, MATREES DOWN ON SUDBURY RD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 10.0 hours before the alert went out and 129 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 2012-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 834 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, Chatham, MA at 12:00Z on 2012-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 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
834 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
508 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
49 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.

822 
WUUS51 KBOX 072159
SVRBOX
MAC009-017-021-025-072245-
/O.NEW.KBOX.SV.W.0099.120907T2159Z-120907T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
559 PM EDT FRI SEP 7 2012

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EXTREME SOUTH CENTRAL ESSEX COUNTY IN EASTERN MASSACHUSETTS...
  NORTH CENTRAL NORFOLK COUNTY IN EASTERN MASSACHUSETTS...
  THIS INCLUDES THE CITY OF BROOKLINE...
  SUFFOLK COUNTY IN EASTERN MASSACHUSETTS...
  THIS INCLUDES THE CITY OF BOSTON...
  CENTRAL MIDDLESEX COUNTY IN SOUTHEAST MASSACHUSETTS...
  THIS INCLUDES THE CITIES OF...WALTHAM...SOMERVILLE...NEWTON...
  CAMBRIDGE...

* UNTIL 645 PM EDT

* AT 551 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH. TORRENTIAL RAINFALL IS ALSO 
  LIKELY WITH THIS STORM. THIS STORM WAS LOCATED NEAR LINCOLN...OR 
  NEAR WALTHAM...AND WAS MOVING EAST AT 10 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE...BEDFORD...WESTON...
  LEXINGTON...WELLESLEY...WOBURN...WINCHESTER...WATERTOWN...
  STONEHAM...SAUGUS...MILTON...MELROSE...MEDFORD...MALDEN...
  EVERETT...CHELSEA...BELMONT AND ARLINGTON.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS AND LARGE HAIL...AS WELL
AS DEADLY LIGHTNING AND TORRENTIAL RAIN. GET TO SAFE SHELTER NOW...
INSIDE A STURDY BUILDING OR IN A VEHICLE. DO NOT SEEK SHELTER UNDER
TREES. IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY
LIGHTNING. DRIVERS SHOULD BE ALERT FOR PONDING OF WATER AND AVOID
FLOODED ROADS.

&&

LAT...LON 4247 7098 4223 7108 4235 7146 4252 7139
TIME...MOT...LOC 2158Z 287DEG 8KT 4241 7131

$$

BELK

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 4:39 PM EDTHigh Surf AdvisoryBOXBarnstable, Bristol, Dukes, Essex, Nantucket, Norfolk and 1 more4 days
Sep 7, 4:42 PM EDTSmall Craft AdvisoryBOX4 days
Sep 7, 5:46 PM EDTSpecial Weather StatementBOXMiddlesex59 min
Sep 7, 6:14 PM EDTSpecial Weather StatementBOXSuffolk31 min
Sep 7, 6:42 PM EDTAreal Flood AdvisoryBOXMiddlesex, Norfolk, Suffolk55 min
Sep 7, 7:12 PM EDTSpecial Weather StatementBOXWorcester48 min
Sep 7, 7:20 PM EDTAreal Flood AdvisoryBOXEssex, Middlesex, Norfolk, Suffolk100 min
Sep 7, 7:34 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampshire, Worcester26 min
Sep 7, 7:53 PM EDTSpecial Weather StatementBOXWorcester52 min
Sep 7, 7:57 PM EDTAreal Flood AdvisoryBOXFranklin, Hampshire, Worcester93 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2012Every severe thunderstorm warning in 2012

Sources

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