Alert archive / Massachusetts / Tornado Watches in 2008

Tornado Watch 937

November 15, 20084 states

The Storm Prediction Center issued this tornado watch at Nov 15, 2008, 6:55 PM EST for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Nov 15, 2008, 6:55 PM EST (23:55 UTC)
Expired
Nov 15, 2008, 9:31 PM EST
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 30 counties

Capitol Planning Region, CT, Greater Bridgeport Planning Region, CT, Lower Connecticut River Valley Planning Region, CT, Naugatuck Valley Planning Region, CT, Northeastern Connecticut Planning Region, CT, Southeastern Connecticut Planning Region, CT, Bristol County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Suffolk County, NY, Westchester County, NY, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI

The radar

The Boston radar (KBOX), 96 km from the middle of the area, began a volume at 23:58 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
30%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
10%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Nov 15, 7:39 PM ESTSevere Thunderstorm WarningOKXGreater Bridgeport Planning Region22 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 11.9 hours before the alert went out and 126 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, Brookhaven, NY at 12:00Z on 2008-11-15Temperature 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 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2008-11-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 246 square meters per square second.1939587897117Sfc1 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
604 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
246 m²/s²
0-3 km storm-relative helicity
314 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.

000
WWUS20 KWNS 152356
SEL7  
SPC WW 152356
CTZ000-MAZ000-NYZ000-RIZ000-CWZ000-160700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 937
NWS STORM PREDICTION CENTER NORMAN OK
650 PM EST SAT NOV 15 2008

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       CONNECTICUT
       MASSACHUSETTS
       SOUTHEASTERN NEW YORK
       RHODE ISLAND
       COASTAL WATERS

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 650 PM
UNTIL 200 AM EST.

TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 35 MILES NORTH NORTHEAST OF
WORCESTER MASSACHUSETTS TO 20 MILES EAST SOUTHEAST OF ISLIP NEW
YORK.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 934...WW 935...WW 936...

DISCUSSION...BROKEN BAND OF SHOWERS/OCCASIONAL TSTMS OVER THE LWR
HUDSON VLY SWD INTO NJ EXPECTED TO CONTINUE ENE INTO NEW ENG LATER
THIS EVE AS INDIVIDUAL CELLS MOVE RAPIDLY NNE ALONG IT.  BOUNDARY
LAYER HAS SLIGHTLY WARMED/MOISTENED IN THE PAST 2 HRS ACROSS
WW...AND MAIN SFC LOW OVER UPSTATE NY IS EXPECTED TO CONTINUE
DEEPENING /LIKELY MAINTAINING AXIS OF CONVERGENCE ALONG CONVECTIVE
BAND/.  ALTHOUGH LOW LVL LAPSE RATES WILL REMAIN WEAK...COMBINATION
OF STRONG WIND FIELD WITH EXISTING UPDRAFTS SUGGESTS AN EWD SPREAD
OF ISOLD TORNADO THREAT FROM THE LWR HUDSON VLY/NRN NJ INTO
SRN/CNTRL NEW ENG.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
300. MEAN STORM MOTION VECTOR 22045.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 15, 2:56 PM ESTTornado WatchSPCNorthwest Hills Planning Region6 hr
Nov 15, 6:15 PM ESTMesoscale DiscussionSPC2 hr
Nov 15, 1:47 PM ESTMesoscale DiscussionSPCColumbia, Delaware, Dutchess, Greene, New York, Orange and 5 more58 min

Nearby

Tornado Watches in Massachusetts, 2008Tornado Watches in New York, 2008Tornado Watches in Connecticut, 2008Every tornado watch in 2008

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.