Hillsdale, NY and Great Barrington, MA Tornadoes
May 29, 1995
is not especially prone to large scale destructive severe weather outbreaks
due in large part to geography. However, on occasion, large violent
thunderstorms do develop and go on to produce damaging straight line winds,
large damaging hail, and in rare instances, large damaging tornadoes.
For example, on June 9, 1953 and extremely violent tornado leveled parts
of Worcester, MA killing 94, injuring over 1000, and leaving 10,000 people
homeless. On August 28, 1973, a large tornado hit the town of West
Stockbridge, MA killing four and injuring forty people. More recently,
on May 12, 1984 a moderate tornado injured eleven people on the Altamont
fairgrounds and one in Schenectady, NY as well as damaging property.
And on November 16, 1989, a tornado, which had dissipated into a straight
line wind gust, crumbled a wall at the East Coldenham Elementary School
in Montgomery, NY killing seven children. Even with the historical occurrences
of damaging tornadoes in the Northeast, many residents of the southeast
Columbia county, NY, and in Egremont, Great Barrington, and Monterey,
Massachusetts in Berkshire county were stunned, when shortly after 6:30pm
on the evening of May 29, 1995 two powerful tornadoes, spawned from one
rotating thunderstorm, struck.
Aspects of the May 29, 1995 Tornado Event
MORNING, MAY 29, 1995
weather charts showed a warm front slowly moving northward across New
York and southern New England. The warm front produced a cloudy, cool,
and showery start to the Memorial day holiday across the region. Sunshine,
however, began burning through the low overcast during the late morning
setting the stage for later events. A powerful cold front, extending from
low pressure located over Ontario, was plowing eastward into the increasingly
warm and humid air over western New York. Radars displayed a broken line
of showers and thunderstorms developing in the moist air mass over central
New York. These thunderstorms were the beginnings of what would develop
into an evening weather disaster further east.
Dewpoint temperatures steadily edged up through the sixties and temperatures
climbed into the seventies through the morning and early afternoon providing
the necessary moisture and heat that thunderstorms need in order to grow.
Using temperature, moisture, and wind information from the National Weather
Service balloon launches at 8:00 am, regional meteorologists, including
myself, analyzed soundings of upper level atmospheric conditions for the
Northeast to determine if weather parameters aloft were as favorable for
severe thunderstorms as the surface parameters appeared to be.
The upper air profiles revealed several very interesting facts. A surface
air temperature of 73 degrees F and dewpoint temperature of 68 degrees
F would be sufficient to trigger large thunderstorms with no aid from
any other atmospheric parameters. That fact alone was very impressive.
The profiles also indicated that a tremendous amount of wind shear, especially
along the advancing warm front, was present. For example, wind velocities
increased from 12 knots at the surface to 36 knots at 7000 feet and the
directional change in the winds measured greater than 60 degrees. Those
numbers indicate strong directional and speed shear, parameters quite
favorable for supporting severe weather.
It was apparent
to me that there would be sufficient heat and humidity to spark thunderstorms
as sunshine continued to increase over New York and New England sending
temperatures soaring beyond the needed 73 degree F critical temperature.
Southeasterly surface winds established themselves, transporting additional
moisture into the atmospheric brew guaranteeing dewpoint temperatures
would be in the upper 60's later in the day. Simultaneously, increasing
westerly winds aloft were increasing the wind shear as each hour passed.
The initial parameters were coming together for a major severe weather
On close inspection of the smaller atmospheric details present during
the early afternoon of May 29, 1995 it became very clear to me that not
only some of the parameters necessary for severe weather were coming together
but almost every parameter in the proverbial book seemed to be in place
or would be in place later in the day to support a large severe weather
event. For example, a cold air pocket aloft at around 20,000 feet above
the ground was due to arrive over eastern New York at the time of maximum
surface heating. The arrival of the spinning cold pool aloft would cause
a further and rapid destabilization of the atmosphere supporting severe
thunderstorms. The warm sector of air at the ground was in place with
thunderstorms already developing along the strong cold front. Upper winds
in the atmosphere were diffluent. In other words, winds aloft were blowing
away from each other allowing the thunderstorms to vent, potentially increasing
their intensity. Lastly, and perhaps most importantly, the wind shear
over New York and New England was unusually strong and increasing promoting
the development of rotating supercell thunderstorms and tornadoes.
later be determined through research by meteorologists at the Albany National
Weather Service forecast office that local terrain effects were responsible
for increasing the low level wind shear environment in southeast Columbia
county, NY and in Berkshire county, MA which supported the intense supercell
thunderstorm that produced the tornadoes.
SEVERE WEATHER BEGINS
The National Severe Storms Forecast Center in Kansas City, Missouri (now
called the Storm Prediction Center) issued the first of several severe
thunderstorm watches for the day. The initial watch included all of upstate
eastern New York and was issued to cover the developing thunderstorms
over central New York during the morning. Damaging winds, hail, frequent
lightning, and heavy rain were all possible and likely in this watch area.
At this point there was no "Official" mention of the possibility
4:30 pm TORNADO WARNING
Binghamton, NY National Weather Service Doppler weather radar began showing
rotation in a thunderstorm moving into Otsego county, NY at 4:30pm. The
first tornado warning of the day was issued at 4:30 pm to cover this storm.
By 5:15 pm radar showed the storm weakening. A few reports of scattered
straight line wind damage were relayed to the National Weather Service.
Apparently, no tornado had formed from the rotating thunderstorm, which
is not altogether unusual. Through 6:30 pm, scattered heavy thunderstorms
moved through the greater Capital District, producing isolated pockets
of wind damage near Rotterdam, NY, and large hail in Poestenkill, NY.
The Albany Doppler radar, located in Berne, NY, did not indicate any significant
development to the storms through 6pm. The relative calm did not last
RAPID STORM INTENSIFICATION
At 6:30 pm, the thunderstorm cell that had been associated with the tornado
warning for Otsego county two hours earlier had held together and moved
into eastern Greene county, NY. The Albany Doppler radar detected an intensifying
circulation of wind inside the storm. The storm grew rapidly, almost exploding
as it encountered increase low level wind shear and high dewpoint air
in the Hudson valley. A tornado warning for Columbia county, NY
was issued at about 6:40 pm. The storm's trajectory had it aimed straight
for the Egremont, Great Barrington, MA area in southern Berkshire county.
Warnings were broadcast first on WRGB giving residents of southeast Columbia
county NY and Great Barrington, MA an unprecedented 21 minutes lead time.
9:00 pm DAMAGE REPORTS
"Like a bomb went off..." That was a quote from a caller in
the Great Barrington area to Channel 6. Radar had pegged it, an apparently
devastating storm had ripped through southern Berkshire county. Reports
from Columbia county, NY also indicated a serious storm had moved through
producing extensive damage to buildings and trees. Home video arrived
at Channel 6 by 9:15 pm from a family traveling north on New York's Taconic
parkway. The video showed a fifty foot wide path of destruction across
the highway and into the woods. The tell tale twisting of debris was convincing
evidence that a tornado had been on the ground and was responsible for
AFTER, TUESDAY, MAY 30, 1995 - THE DESTRUCTION
The official report from the teams of meteorologists dispatched from the
Albany, NY National Weather Service forecast office to survey the damage
concluded the following:
Multiple homes and wooded areas sustained extensive damage in the towns
of Greenport and Hillsdale in Columbia county, NY from a tornado which
began at 6:40 pm and continued through 7:00 pm. The path length of the
tornado was estimated to be thirteen miles long. The storm packed winds
estimated between 73 mph to 135 mph.
In Berkshire county, MA, the same parent thunderstorm responsible for
the Columbia county tornado produced another, and more violent tornado.
Damage began at 7:06 pm at the Great Barrington airport and ended in Monterey,
MA at 7:16 pm. Over a length of seven miles and maximum width of 300 yards,
the Great Barrington tornado produced a swath of devastation through
the town, destroying buildings, tossing cars, and shearing off tree tops.
Three people were killed, 27 injured, over 100 homes and businesses were
either damaged or destroyed, and many thousands of trees were felled by
the storm. Winds in the Great Barrington tornado were estimated to range
up to 165 mph making it one of the strongest tornadoes on record
in the Northeast.
County Damage Photographs (Photographs by Steve LaPointe)
#1 of 5: May 30, 1995....Decimated forest along route 23 approaching
Great Barrington, MA
trees in this photograph are merely a handful of the thousands of trees
felled by the tornado. The tree tops were sheared off by winds estimated
over 100mph. Debris from the forest shelled the roof of the home in the
background of the photograph, producing extensive damage. Had the tornado
been level with the ground at this point, the home would likely have suffered
damage even more severe than the large holes in the roof. Within minutes
after obliterating these trees the tornado went on to devastate the Great
Barrington fairgrounds. The next three photographs illustrate the power
of the tornado as it tore through the fairgrounds.
#2 of 5: May 30, 1995...Destruction of the Great Barrington fairgrounds
full force of the tornado bore down on the fairgrounds reducing the pavilion
to a pile of twisted debris. Winds at this point in the tornado's life
were close to 150mph splintering the roof and gutting the interior. Fortunately
the buildings were vacant at the time of the storm, so there were no injuries
or fatalities on the fairgrounds.
#3 of 5: May 30, 1995...Destruction of the Great Barrington fairgrounds
section of the pavilion crumbled under the force of the tornado. Typically,
once the roof blows off a structure the walls collapse very easily, which
was the case in this instance. Notice the debris behind the front wall...This
is mostly the remains of the roof indicating it blew off first allowing
the front, side, and interior walls to collapse, obliterating the entire
section of the building.
#4 of 5: May 30, 1995...Destruction of the Great Barrington fairgrounds
is another view of the ruined pavilion. Some of the surrounding debris
actually belonged to buildings that were not part of the fairgrounds.
As the tornado moved through town damaging trees and buildings it picked
up pieces of debris and deposited them hundreds of feet away. Notice in
the background of the photograph, the impact point on East Mountain where
the tornado slammed into the hill. The next photograph is a close up examination
of the impact point.
#5 of 5: May 30, 1995...Tornado Impact on East Mountain
demolishing the fairgrounds, the tornado slammed into the side of East
Mountain, leveling a section of the forest covering the hill. From the
photograph it's apparent that the tornado literally hit the mountain and
then quickly lifted off the ground, since trees along the top and bottom
of the mountain show no damage. As the storm hopped over the mountain
it touched down again in Monterey where it attained its maximum intensity
with winds estimated briefly in excess of 150 mph.
The intensification of the storm on the other side of East Mountain is
not a surprise. As the tornado column descended over the lower elevation
adjacent to the mountain, the column stretched vertically causing the
winds to increase. The physics involved are known as conservation of angular
momentum. It's the same process that allows a figure skater to spin faster
when pulling in the arms and extending them upwards.
Also, notice the rotary damage pattern in the trees. The trees are blown
down in a pattern showing the counterclockwise spinning motion of the
air around the tornado. This type of damage pattern is what meteorologist
look for when trying to determine whether or not storm damage was caused
by a tornado or severe thunderstorm straight line winds. If the damage
in this photograph had been caused by straight line winds the trees along
the entire slope of the mountain would have been blown down in one direction,
not in the rotary pattern shown.
Doppler Radar (NEXRAD) Images of the Tornado Event
National Weather Service Doppler Radar Reflectivity Display
on the Channel 6 Weather Spectrum 9000 Computer
degree Elevation Tilt
7:01 pm May 29, 1995
The radar image above is called a reflectivity display. The radar emits
a beam of radiation which bounces off precipitation and returns to the
emitter. From the returned pulse, the radar generates an image which shows
areas of precipitation and precipitation intensity, a line of intense
thunderstorm in this case. The various colors give an estimate of the
intensity and even the type of precipitation occurring. The blue and green
shades indicate light rain in this case and the yellow, orange, and red
shades indicate heavy rain and hail.
There are two storms of note on the display. The storm circled over western
Massachusetts was producing the tornado that struck Great Barrington at
the time this image was taken. A storm over northern Fairfield county,
CT (due south of the Massachusetts storm on the map) was also suspected
at this time of producing a tornado. The reflectivity on the Connecticut
storm is quite impressive given the distance that storm was from the radar
site which is located in Berne, NY in Albany county. The next image is
a close look at the Great Barrington, MA supercell thunderstorm.
National Weather Service Doppler Radar Reflectivity Display
degree Elevation Tilt, Close-up
7:01 pm May 29, 1995
This is a close-up look at the parent thunderstorm which produced the
devastating Great Barrington, MA tornado. This type of thunderstorm is
called a supercell. Supercell thunderstorms rotate, most in a counterclockwise
direction. These types of storms actually form small centers of low pressure,
called mesocyclones. The mesocyclone in this case is located at the head
of the arrow in an area of very light precipitation. From the mesocyclone
the smaller tornado circulation sometimes develops. The radar signature
of the mesocyclone, illustrated in this image, is called a hook echo.
National Weather Service Doppler Radar Radial Velocity Display
on the Channel 6 Weather Spectrum 9000 Computer
degree Elevation Tilt
7:01pm, May 29, 1995
The colors on this display are not indicating precipitation but instead
showing wind speeds and directions relative to the Albany radar site.
This image is called a radial velocity display and is the heart of what
makes Doppler radar such an important tool in forecasting local severe
The physics are known as the Doppler effect. Essentially, the radar emits
a beam of radiation at a certain frequency. When the beam bounces off
a particle in the atmosphere which is in motion such as precipitation,
dust, or even bugs, the frequency of the reflected beam of radiation returning
to the radar is shifted. The shift in frequency is called the Doppler
shift. From the frequency shift the radar is able to determine whether
the wind is blowing away from or towards the radar site and is able to
determine a velocity that is a close approximation to the actual speed
of the particle.
The yellow, red, and orange colors on the picture above indicate winds
blowing away from the radar site at various velocities and elevations
and the greens and blues indicate winds blowing towards the radar site
at various velocities and elevations.
The term for the radar indication in the image above is called a mesocyclone
vortex signature. The thunderstorm's circulation is evident by there being
an area of bright red shading, which shows strong winds blowing away from
the radar, directly next to an area of green shading, which shows an area
of strong winds blowing towards the radar site. This radar signature shows
the parent circulation from which the smaller tornado vortex evolves.
By being able to see the small scale wind currents within severe thunderstorms
meteorologists can now give tremendous tornado warning lead times. In
fact, this signature on the Doppler allowed a 21 minute warning lead time
to the arrival of the tornado in Great Barrington, saving peoples lives.