Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2014

Severe Thunderstorm Warning 9, NWS Boston/Norton, MA

May 25, 2014Hillsborough County, New Hampshire; Middlesex County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at May 25, 2014, 6:30 PM EDT for Hillsborough County, New Hampshire; Middlesex County, Worcester County, Massachusetts. It was in force for 30 min. 3 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
May 25, 2014, 6:30 PM EDT (22:30 UTC)
Expired
May 25, 2014, 7:00 PM EDT
In force
30 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon

Counties Middlesex County, MA, Worcester County, MA, Hillsborough County, NH

The radar

The Boston radar (KBOX), 94 km from the middle of the area, began a volume at 22:32 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
May 25, 6:30 PM EDTHAIL 0.75Brookline, NH
May 25, 6:50 PM EDTHAIL 1Brookline, NH
May 25, 7:02 PM EDTHAIL 1Pepperell, MA

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

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 10.5 hours before the alert went out and 169 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, Gray, ME at 12:00Z on 2014-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Gray, ME at 12:00Z on 2014-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
619 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
65 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.

598 
WUUS51 KBOX 252230
SVRBOX
MAC017-027-NHC011-252300-
/O.NEW.KBOX.SV.W.0009.140525T2230Z-140525T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
630 PM EDT SUN MAY 25 2014

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN WORCESTER COUNTY IN CENTRAL MASSACHUSETTS...
  NORTHWESTERN MIDDLESEX COUNTY IN NORTHEAST MASSACHUSETTS...
  SOUTH CENTRAL HILLSBOROUGH COUNTY IN SOUTHERN NEW HAMPSHIRE...

* UNTIL 700 PM EDT

* AT 630 PM EDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING QUARTER SIZE HAIL. THIS STORM WAS LOCATED NEAR
  HOLLIS...OR NEAR MERRIMACK...AND WAS MOVING SOUTH AT 25 MPH.

* SOME LOCATIONS IMPACTED INCLUDE...
  NASHUA...CHELMSFORD...MERRIMACK...HUDSON...WESTFORD...MILFORD...
  PEPPERELL...TYNGSBOROUGH...AMHERST...GROTON...LUNENBURG...
  TOWNSEND...LITTLETON...LITCHFIELD...LANCASTER...HOLLIS...AYER...
  SHIRLEY...HARVARD AND BROOKLINE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS AND LARGE HAIL. GO
INDOORS AND STAY AWAY FROM WINDOWS.  DRIVERS SHOULD PREPARE FOR LOW
VISIBILITY AND AVOID FLOODED ROADS.

&&

LAT...LON 4286 7173 4289 7150 4255 7135 4250 7171
TIME...MOT...LOC 2230Z 349DEG 22KT 4279 7160 
$$

RLG

The office that day

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

IssuedProductOfficeCountiesLasted
May 25, 3:03 PM EDTSevere Thunderstorm WarningBOXCheshire, Hillsborough27 min
May 25, 5:12 PM EDTSevere Thunderstorm WarningBOXHillsborough48 min
May 25, 5:57 PM EDTSevere Thunderstorm WarningBOXHillsborough33 min
May 25, 6:57 PM EDTSevere Thunderstorm WarningBOXHillsborough48 min
May 25, 1:07 PM EDTSpecial Weather StatementBOXWorcester83 min
May 25, 1:42 PM EDTSevere Thunderstorm WarningBOXWorcester33 min
May 25, 2:15 PM EDTSevere Thunderstorm WarningBOXWorcester30 min
May 25, 3:25 PM EDTSpecial Marine WarningBOX95 min
May 25, 4:45 PM EDTSmall Craft AdvisoryBOX37 hr
May 25, 7:40 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Worcester50 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2014Severe Thunderstorm Warnings in New Hampshire, 2014Every severe thunderstorm warning in 2014

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.