Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 46, NWS Boston/Norton, MA

July 18, 2012Essex County, Middlesex County, Massachusetts; Hillsborough County, New Hampshire

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 18, 2012, 12:54 PM EDT for Essex County, Middlesex County, Massachusetts; Hillsborough County, New Hampshire. It was in force for 66 min. 4 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, 2012, 12:54 PM EDT (16:54 UTC)
Expired: Jul 18, 2012, 2:00 PM EDT
In force: 66 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon

Counties Essex County, MA, Middlesex County, MA, Hillsborough County, NH

The radar

The Boston radar (KBOX), 88 km from the middle of the area, began a volume at 16:55 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
Jul 18, 1:23 PM EDT	HAIL 1	Dracut, MA
Jul 18, 1:55 PM EDT	FUNNEL CLOUD	Peabody, MA
Jul 18, 2:00 PM EDT	HAIL 0.88	Lynnfield, MA
Jul 18, 2:03 PM EDT	HAIL 1.25	Peabody, MA

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 18, 12:20 PM EDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 4.9 hours before the alert went out and 141 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: 37 J/kg
Mixed-layer CIN: -325 J/kg
Mixed-layer LCL: 861 m above ground
0-6 km bulk shear: 68 kt
0-1 km storm-relative helicity: -43 m²/s²
0-3 km storm-relative helicity: 15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

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

790 
WUUS51 KBOX 181654
SVRBOX
MAC009-017-NHC011-181800-
/O.NEW.KBOX.SV.W.0046.120718T1654Z-120718T1800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
1254 PM EDT WED JUL 18 2012

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ESSEX COUNTY IN EASTERN MASSACHUSETTS...
  SOUTHEASTERN HILLSBOROUGH COUNTY IN SOUTHERN NEW HAMPSHIRE...
  NORTHERN MIDDLESEX COUNTY IN SOUTHEAST MASSACHUSETTS...

* UNTIL 200 PM EDT

* AT 1248 PM EDT...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 PEPPERELL...OR 5
  MILES SOUTHWEST OF NASHUA...AND MOVING EAST AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  LOWELL...NASHUA...LAWRENCE...BEVERLY...NEWBURYPORT...DRACUT...
  PELHAM...NORTH ANDOVER...GROVELAND...HAVERHILL...NEWBURY...
  WEST NEWBURY...PEABODY...METHUEN...HAMILTON...WENHAM...
  CHELMSFORD...DANVERS...WILMINGTON AND AMESBURY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 60 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING AND VERY HEAVY RAIN. FOR YOUR
PROTECTION...MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4287 7082 4282 7081 4281 7087 4282 7082
      4256 7077 4253 7078 4255 7083 4251 7082
      4255 7083 4253 7090 4251 7085 4251 7085
      4260 7161 4278 7162 4282 7139 4277 7135
      4274 7119 4281 7116 4281 7107 4289 7093
TIME...MOT...LOC 1648Z 269DEG 26KT 4269 7158 

$$

KJC

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:23 PM EDT	Special Weather Statement	BOX	Essex	67 min
Jul 18, 12:37 PM EDT	Special Weather Statement	BOX	Middlesex	53 min
Jul 18, 12:41 PM EDT	Heat Advisory	BOX	Bristol, Essex, Franklin, Hampden, Hampshire, Middlesex and 2 more	6 hr
Jul 18, 1:21 PM EDT	Special Marine Warning	BOX		84 min
Jul 18, 1:29 PM EDT	Flash Flood Warning	BOX	Essex, Middlesex	98 min
Jul 18, 1:43 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Suffolk	36 min
Jul 18, 1:45 PM EDT	Special Marine Warning	BOX		60 min
Jul 18, 1:50 PM EDT	Special Weather Statement	BOX	Hampden	40 min
Jul 18, 2:04 PM EDT	Severe Thunderstorm Warning	BOX	Hampden, Hampshire, Worcester	56 min
Jul 18, 2:04 PM EDT	Tornado Warning	BOX	Essex, Suffolk	12 min
Jul 18, 2:21 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Suffolk	39 min
Jul 18, 2:21 PM EDT	Severe Thunderstorm Warning	BOX	Hampden	54 min
Jul 18, 2:24 PM EDT	Flash Flood Warning	BOX	Hampden, Worcester	3 hr
Jul 18, 2:30 PM EDT	Special Marine Warning	BOX		90 min
Jul 18, 2:39 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Middlesex, Norfolk, Plymouth, Suffolk, Worcester	51 min
Jul 18, 2:44 PM EDT	Severe Thunderstorm Warning	BOX	Hampden, Norfolk, Worcester	61 min
Jul 18, 3:09 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Norfolk, Worcester	51 min
Jul 18, 3:46 PM EDT	Severe Thunderstorm Warning	BOX	Barnstable, Bristol, Norfolk, Plymouth	59 min
Jul 18, 4:04 PM EDT	Special Marine Warning	BOX		56 min
Jul 18, 4:25 PM EDT	Special Marine Warning	BOX		80 min
Jul 18, 4:42 PM EDT	Severe Thunderstorm Warning	BOX	Barnstable, Plymouth	36 min
Jul 18, 5:08 PM EDT	Special Weather Statement	BOX	Norfolk, Suffolk	52 min
Jul 18, 5:24 PM EDT	Flash Flood Warning	BOX	Middlesex, Norfolk, Suffolk	78 min
Jul 18, 5:27 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Norfolk, Plymouth, Suffolk	48 min
Jul 18, 5:30 PM EDT	Special Marine Warning	BOX		54 min
Jul 18, 6:08 PM EDT	Special Marine Warning	BOX		67 min
Jul 18, 6:27 PM EDT	Special Weather Statement	BOX	Essex	33 min
Jul 17, 8:03 PM EDT	Severe Thunderstorm Warning	BOX	Hillsborough	13 min
Jul 17, 8:46 PM EDT	Special Weather Statement	BOX	Cheshire	44 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2012 Severe Thunderstorm Warnings in New Hampshire, 2012 Every 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.