Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 3, NWS Boston/Norton, MA

May 7, 2011Middlesex County, Norfolk County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at May 7, 2011, 1:08 PM EDT for Middlesex County, Norfolk County, Massachusetts. It was in force for 52 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
May 7, 2011, 1:08 PM EDT (17:08 UTC)
Expired
May 7, 2011, 2:00 PM EDT
In force
52 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon

Counties Middlesex County, MA, Norfolk County, MA

The radar

The Boston radar (KBOX), 37 km from the middle of the area, began a volume at 17:08 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 nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 5.1 hours before the alert went out and 130 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 2011-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 72 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 2011-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 square meters per square second.1939587897Sfc1 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
72 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
793 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
45 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.

538 
WUUS51 KBOX 071708
SVRBOX
MAC017-021-071800-
/O.NEW.KBOX.SV.W.0003.110507T1708Z-110507T1800Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
108 PM EDT SAT MAY 7 2011

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL NORFOLK COUNTY IN EASTERN MASSACHUSETTS...
  SOUTH CENTRAL MIDDLESEX COUNTY IN SOUTHEAST MASSACHUSETTS...

* UNTIL 200 PM EDT

* AT 104 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
  STORM WAS LOCATED NEAR ASHLAND...OR NEAR FRAMINGHAM...AND WAS
  MOVING EAST AT 20 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE...SHERBORN AND DOVER.

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 4228 7125 4221 7124 4220 7147 4227 7149
TIME...MOT...LOC 1708Z 268DEG 16KT 4224 7146

$$
FIELD
1 follow-up statement
352 
WWUS51 KBOX 071738
SVSBOX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
138 PM EDT SAT MAY 7 2011

MAC017-021-071800-
/O.CON.KBOX.SV.W.0003.000000T0000Z-110507T1800Z/
MIDDLESEX MA-NORFOLK MA-
138 PM EDT SAT MAY 7 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR NORTH CENTRAL NORFOLK AND SOUTH CENTRAL MIDDLESEX COUNTIES...

AT 134 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING ONE INCH 
DIAMETER HAIL. THIS STORM WAS LOCATED NEAR DOVER...OR 8 MILES 
SOUTHWEST OF NEWTON...MOVING EAST AT 20 MPH. PENNY SIZE HAIL 
COVERING THE GROUND HAS BEEN REPORTED BY A TRAINED SPOTTER IN 
NATICK. 

LAT...LON 4222 7133 4227 7136 4228 7132 4228 7125
      4221 7124
TIME...MOT...LOC 1737Z 264DEG 16KT 4225 7129

$$
FIELD

The office that day

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

IssuedProductOfficeCountiesLasted
May 7, 11:32 AM EDTSpecial Weather StatementBOXWorcester43 min
May 7, 12:28 PM EDTSpecial Weather StatementBOXMiddlesex32 min
May 7, 12:31 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Worcester29 min
May 7, 1:32 PM EDTSpecial Weather StatementBOXNorfolk43 min
May 7, 2:08 PM EDTSpecial Weather StatementBOXNorfolk37 min
May 7, 4:53 PM EDTSpecial Weather StatementBOXMiddlesex52 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2011Every severe thunderstorm warning in 2011

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.