Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 67, NWS Boston/Norton, MA

July 18, 2011Barnstable County, Plymouth County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 18, 2011, 5:17 PM EDT for Barnstable County, Plymouth County, Massachusetts. It was in force for 32 min. 2 reports 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: Jul 18, 2011, 5:17 PM EDT (21:17 UTC)
Expired: Jul 18, 2011, 5:49 PM EDT
In force: 32 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon

Counties Barnstable County, MA, Plymouth County, MA

The radar

The Boston radar (KBOX), 58 km from the middle of the area, began a volume at 21:20 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

Time	Report	Where	Remark
Jul 18, 5:20 PM EDT	TSTM WND DMG	Wareham, MA	TREE DOWN ON CAR ON SANDWICH ROAD AND TREE DOWN ON HOUSE ON PERRY AVE.
Jul 18, 5:32 PM EDT	TSTM WND DMG	Sagamore, MA	KAYAK TURNED OVER OFF SAGAMORE BEACH WITH PERSON NEEDING TO BE RESCUED

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, 9.3 hours before the alert went out and 44 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 732 J/kg
Mixed-layer CIN: -158 J/kg
Mixed-layer LCL: 1048 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 66 m²/s²
0-3 km storm-relative helicity: 96 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 182117
SVRBOX
MAC001-023-182200-
/O.NEW.KBOX.SV.W.0067.110718T2117Z-110718T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
517 PM EDT MON JUL 18 2011

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL BARNSTABLE COUNTY IN SOUTHEAST MASSACHUSETTS...
  THIS INCLUDES THE CITY OF BARNSTABLE...
  SOUTHEASTERN PLYMOUTH COUNTY IN SOUTHEAST MASSACHUSETTS...

* UNTIL 600 PM EDT

* AT 511 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.  THIS STORM WAS LOCATED NEAR
  WAREHAM...OR 13 MILES NORTHEAST OF NEW BEDFORD...AND WAS MOVING
  EAST AT 45 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE...BOURNE...SANDWICH...
  YARMOUTH...DENNIS...BREWSTER AND HARWICH.

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 4162 7025 4170 7065 4171 7064 4169 7068
      4171 7067 4172 7071 4170 7071 4170 7074
      4182 7074 4184 7053 4181 7053 4177 7047
      4172 7026 4176 7020 4179 7003 4188 7007
      4189 7006 4179 7003 4166 7002
TIME...MOT...LOC 2116Z 272DEG 39KT 4177 7066

$$

THOMPSON

2 follow-up statements

992 
WWUS51 KBOX 182133
SVSBOX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
533 PM EDT MON JUL 18 2011

MAC001-023-182200-
/O.CON.KBOX.SV.W.0067.000000T0000Z-110718T2200Z/
BARNSTABLE MA-PLYMOUTH MA-
533 PM EDT MON JUL 18 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR SOUTHEASTERN PLYMOUTH AND CENTRAL BARNSTABLE COUNTIES...

AT 530 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR SANDWICH...OR 9 MILES NORTHWEST OF BARNSTABLE...MOVING
EAST AT 40 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
HYANNIS...YARMOUTH...DENNIS...BREWSTER AND HARWICH. THE CAPE COD BAY 
SIDE OF CAPE COD WILL BE MOST VULNERABLE TO ANY DAMAGING WINDS.

LAT...LON 4162 7025 4170 7065 4171 7064 4169 7068
      4171 7067 4172 7071 4170 7071 4170 7074
      4182 7074 4184 7053 4181 7053 4177 7047
      4172 7026 4176 7020 4179 7003 4188 7007
      4189 7006 4179 7003 4166 7002
TIME...MOT...LOC 2132Z 272DEG 39KT 4176 7043

$$

THOMPSON

322 
WWUS51 KBOX 182149
SVSBOX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
549 PM EDT MON JUL 18 2011

MAC001-023-182157-
/O.CAN.KBOX.SV.W.0067.000000T0000Z-110718T2200Z/
BARNSTABLE MA-PLYMOUTH MA-
549 PM EDT MON JUL 18 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN PLYMOUTH AND
CENTRAL BARNSTABLE COUNTIES IS CANCELLED...

THE STRONGEST PART OF THE STORM HAS BECOME LOCATED OVER CAPE COD BAY 
AND HAS BEGUN TO WEAKEN. THERE WILL STILL BE A THREAT OF LIGHTNING 
AND HEAVY RAIN FROM ANOTHER THUNDERSTORM CELL THAT WAS APPROACHING 
THE UPPER CAPE AT 545 PM.

LAT...LON 4162 7025 4170 7065 4171 7064 4169 7068
      4171 7067 4172 7071 4170 7071 4170 7074
      4182 7074 4184 7053 4181 7053 4177 7047
      4172 7026 4176 7020 4179 7003 4188 7007
      4189 7006 4179 7003 4166 7002
TIME...MOT...LOC 2147Z 272DEG 39KT 4175 7021

$$

THOMPSON

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 12:43 PM EDT	Special Marine Warning	BOX		47 min
Jul 18, 4:44 PM EDT	Special Weather Statement	BOX	Bristol	46 min
Jul 18, 5:12 PM EDT	Special Weather Statement	BOX	Barnstable	48 min
Jul 18, 5:23 PM EDT	Special Marine Warning	BOX		37 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2011 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.