Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 49, NWS Boston/Norton, MA

July 1, 2001Middlesex County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 1, 2001, 4:22 PM EDT for Middlesex County, Massachusetts. It was in force for 38 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 1, 2001, 4:22 PM EDT (20:22 UTC)
Expired
Jul 1, 2001, 5:00 PM EDT
In force
38 min
Issued by
NWS Boston/Norton, MA
Area
Whole counties

County Middlesex County, MA

The radar

The Boston radar (KBOX), 63 km from the middle of the area, began a volume at 20:25 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
Jul 1, 4:30 PM EDTThunderstorm Wind 50 EGroton, MA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

IssuedProductOfficeLasted
Jul 1, 2:15 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 8.4 hours before the alert went out and 148 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 2001-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 156 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 2001-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 square meters per square second.193958Sfc1 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
156 J/kg
Mixed-layer CIN
-140 J/kg
Mixed-layer LCL
1403 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
94 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.

902 
WUUS51 KBOX 012022
SVRBOX
MAC017-012100-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
422 PM EDT SUN JUL 1 2001

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN MIDDLESEX COUNTY IN EASTERN MASSACHUSETTS
    INCLUDING LOWELL

* UNTIL 500 PM EDT.

* AT 420 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER GROTON...OR ABOUT 9 MILES SOUTHWEST OF
  NASHUA...MOVING EAST AT 45 MPH.

* OTHER LOCATIONS IN THE WARNING AREA INCLUDE WESTFORD...TYNGSBORO...
  TEWKSBURY...PEPPERELL...DUNSTABLE...DRACUT AND CHELMSFORD.

SEVERE THUNDERSTORMS PRODUCE LARGE HAIL AND WIND STRONG ENOUGH TO
KNOCK DOWN TREES AND POWER LINES. MOVE INDOORS AND STAY AWAY FROM
WINDOWS.

$$

NOTCHEY
VALLEE

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 9:00 PM EDTSevere Thunderstorm WarningBOXNorfolk45 min
Jun 30, 9:30 PM EDTSevere Thunderstorm WarningBOXWorcester30 min
Jul 1, 2:32 PM EDTSevere Thunderstorm WarningBOXFranklin43 min
Jul 1, 3:24 PM EDTSevere Thunderstorm WarningBOXFranklin, Worcester66 min
Jul 1, 3:58 PM EDTSevere Thunderstorm WarningBOXEssex47 min
Jul 1, 4:38 PM EDTSevere Thunderstorm WarningBOXWorcester52 min
Jul 1, 4:57 PM EDTSevere Thunderstorm WarningBOXEssex48 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2001Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.