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Michael Leduc, Severe Weather Co-ordinator
Michael Leduc has been involved in the Weather Service since 1970 and has held the position of Severe Weather
Co-ordinator since 1983.
During this time he has seen a great deal of change in our
ability to predict, and detect, tornadoes. These changes have
ranged from the development of an extremely sophisticated radar
to ... ham radio enthusiasts! "We already knew that tornadoes
are associated with severe thunderstorms, the majority of which
occur during the warmest time of the year - between April and
September - and the warmest time of the day - between 1 pm and
8 pm." says Michael. But with the use of radars, and more
importantly, volunteers, Environment Canada's Weather Service
in Ontario has been able to forecast more specifically where and
when a tornado will appear.
"We now have a greater understanding of the situations that
produce tornadoes." Michael explains. As a result of that
understanding, and the use of Doppler radars, the ability to detect
the circumstances that cause tornadoes has been greatly increased.
"The conventional radars have a signal that bounces off an
oncoming storm, giving us only an approximate intensity of the
storm; intense storms can produce hail, flooding rains, wind and/or
tornadoes. However, those conventional radars have a limited ability
to distinguish between these elements," Michael explains.
"With Doppler radar, we can actually detect wind circulations
in storms." Since tornadoes have a particular wind circulation,
the ability to differentiate between severe thunder storms, for
example, and tornadoes, has also been greatly increased. The ability
to detect tornadoes earlier provides something crucial to Environment
Canada's severe weather warning capability - TIME. "Fifteen
minutes more notice can make a big difference in the public's
level of preparedness" Michael explains.
However, there are limitations to what radar can offer. In addition
to five weather radars, there are only about 30-40 official observing
sites for weather watching in Ontario, most of which are located
in and around airports. But the majority of tornadoes are not
limited to those areas, so there is often an information gap."
We can see big storms on the radar, but we are often not sure
what's going on underneath," Michael illustrates. That is
where the volunteer service comes in. It seems nothing - not even
Doppler radar - can beat the effectiveness of a keen set of eyes!
In 1979, the Severe Weather Watch and Warning Program began a
volunteer service. And today, there are now between 1,000 and
1,500 weather watch volunteers in Ontario! These volunteers receive
information from the Weather Service outlining specific types
of data required. The watchers then pass on any weather information
they may have at the time of the storm, there are even times when
the Service contacts volunteers to verify radar echoes! The efforts
of volunteers are essential to determining how intense the weather
system is, and in what geographical area it will be most severe.
Another successful method of providing input for the forecasting
and detection of tornadoes that is used by the Weather Service
is also based on the work of volunteers. CAN-WARN is a group of
ham radio operators who advise the Severe Weather forcasters of
any unusual weather occurrences.
The CAN-WARN operators have different Alert Levels - one for a
Severe Weather Watch situation and another if a Severe Weather
Warning is in place. CAN-WARN operators communicate through the
network they have set up specifically for that purpose. "In
a Severe Weather Warning, they'll actually limit the radio traffic
to just reports of severe weather!" Michael says. These operators
take an extremely pro-active approach to weather watching. They
can be the determining factor in issuing warnings, and have further
improved the lead time of those warnings.
Michael Leduc is optimistic that our knowledge of tornadoes and
their causes will continue to grow, "We can learn something
new from every tornado we study," he says. It is this kind
of unremitting interest from Weather Service staff such as Michael,
that ensures continued success in our understanding of tornadoes.
And his commitment ensures that the population of Ontario receives
the crucial weather information they need, information that can
make a difference between life and death.
Ontario Region Success Stories
Great Lakes Success Stories
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