Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 20, NWS Boston/Norton, MA

May 29, 2010Franklin County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at May 29, 2010, 4:09 PM EDT for Franklin County, Worcester County, Massachusetts. It was in force for 36 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 29, 2010, 4:09 PM EDT (20:09 UTC)
Expired: May 29, 2010, 4:45 PM EDT
In force: 36 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon

Counties Franklin County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 108 km from the middle of the area, began a volume at 20:10 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

Albany, NY (KALY), launched 12:00Z, 8.2 hours before the alert went out and 132 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: 219 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 572 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Boston/Norton, MA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 29, 2:24 PM EDT, 1 hour 45 minutes earlier.

Area forecast discussion, May 29, 2:24 PM EDT, 1 hour 45 minutes before

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Hazardous weather outlook, May 29, 4:05 AM EDT, 12 hours 4 minutes before

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In the hours before

Special weather statement, May 29, 3:49 PM EDT, 20 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
349 PM EDT SAT MAY 29 2010

MAZ003-004-292030-
EASTERN FRANKLIN MA-NORTHERN WORCESTER MA-
349 PM EDT SAT MAY 29 2010

AT 340 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE
OF SHOWERS AND THUNDERSTORMS CAPABLE OF PRODUCING WIND GUSTS TO 40
MPH AND SMALL HAIL ALONG A LINE EXTENDING FROM 2 MILES NORTHWEST OF
ROYALSTON TO 2 MILES WEST OF WENDELL...MOVING SOUTHEAST AT 15 MPH.

* SOME LOCATIONS AFFECTED INCLUDE...ATHOL...NEW SALEM...WINCHENDON...
  PHILLIPSTON...PETERSHAM AND TEMPLETON.

HEAVY RAIN MAY CAUSE MINOR STREET FLOODING AND PONDING OF WATER IN
LOW LYING AREAS SUCH AS UNDERPASSES. DO NOT DRIVE THROUGH FLOODED
ROADS. CLOUD TO GROUND LIGHTNING IS OCCURRING AS WELL.

&&

LAT...LON 4272 7225 4270 7189 4234 7228 4235 7228
      4235 7230 4255 7247

MLE

Special weather statement, May 29, 4:05 PM EDT, 4 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
405 PM EDT SAT MAY 29 2010

CTZ002>004-MAZ011-292045-
EASTERN HAMPDEN MA-HARTFORD CT-TOLLAND CT-WINDHAM CT-
405 PM EDT SAT MAY 29 2010

AT 401 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM CAPABLE OF PRODUCING WIND GUSTS TO 40 MPH AND SMALL
HAIL OVER EAST LONGMEADOW...OR ABOUT 4 MILES SOUTH OF
SPRINGFIELD...MOVING SOUTHEAST AT 20 MPH.

* SOME LOCATIONS AFFECTED INCLUDE...HAMPDEN...SOMERS...STAFFORD...
  STAFFORD SPRINGS AND TOLLAND.

HEAVY RAIN MAY CAUSE MINOR STREET FLOODING AND PONDING OF WATER IN
LOW LYING AREAS SUCH AS UNDERPASSES. DO NOT DRIVE THROUGH FLOODED
ROADS. DANGEROUS CLOUD TO GROUND LIGHTNING WILL OCCUR AS WELL.

&&

LAT...LON 4198 7217 4182 7234 4203 7257 4214 7252

MLE

The office that day

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

Issued	Product	Office	Counties	Lasted
May 29, 3:49 PM EDT	Special Weather Statement	BOX	Worcester	41 min
May 29, 3:57 PM EDT	Areal Flood Advisory	BOX	Hampden	93 min
May 29, 4:42 PM EDT	Severe Thunderstorm Warning	BOX	Hampden, Hampshire, Worcester	48 min
May 29, 4:43 PM EDT	Special Weather Statement	BOX	Norfolk	62 min
May 29, 4:52 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Norfolk, Plymouth	47 min
May 29, 5:08 PM EDT	Severe Thunderstorm Warning	BOX	Franklin, Hampden, Hampshire, Worcester	41 min
May 29, 5:36 PM EDT	Special Weather Statement	BOX	Plymouth	54 min
May 29, 4:35 PM EDT	Special Weather Statement	BOX	Providence	40 min
May 29, 4:05 PM EDT	Special Weather Statement	BOX		40 min
May 29, 4:11 PM EDT	Special Weather Statement	BOX		49 min
May 29, 4:26 PM EDT	Severe Thunderstorm Warning	BOX		49 min
May 29, 5:11 PM EDT	Severe Thunderstorm Warning	BOX	Northeastern Connecticut Planning Region	39 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2010 Every severe thunderstorm warning in 2010

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.