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CLASHING CLIMATES
A Primer on Yukon Weather:
Differences Aired Between Warm

and Cold Systems

Whenever tourists start “chatting up TWO SYSTEMS
the locals” in the Yukon Territory, the This influence of air from the Gulf
usual stream of questions seems to of Alaska is one of the two great
dwell on three topics: Yukon history, “systems,” as we might loosely call
ne al attractions and the .- them, which determine Yukon weather.
weather.

Container Route News stories for the The other “system” is the frigid
past 13- years have been rich with ; arctic air mass which has its source
history and géography but, although => in Alaska, Siberia and the Mackenzie
everybody else might be exchanging Valley where the darkness of winter
small talk about it, we haven’t focused. -.. days cools the air to abysmally low
much on the weather. ae 'e temperatures.

There's: lots of questions people ~*~ |° ‘©. The main population of the Yukon
have about the North’s chilly climate— . in Whitehorse is caught between these
and in this issue we’ve looked around - two systems, one very cold and the
for some answers to them. other rather warm, which can seesaw

For instance, why is Whitehorse the thermometer readings in extreme
weather so similar, if not milder than, fashion.
the kind of deep freeze effect found :
in Winnipeg and elsewhere on the W h i
prairies. eat CT Nh

Located at almost exactly the same Y k S
altitude and not too far apart, White- Uu On ever c
horse and Watson Lake have very dif- Herb Wahl, senior officer of the
ferent weather patterns. Why is this Whitehorse Weather station, notes that
yF on February 3, 1968 his station re-
Let's take a look at the weather. corded -60; within three days, Wahl

According to Norm Penny, Weather added, the thermometer had risen to
Information Officer of the Vancouver 38 above.

Weather Office, Meteorological Ser- AROUND THE CLOCK

vice of Canada, the most basic thing
you can say about the Yukon’s climate
is that it is “continental.”

A “continental” region, contrasted
with “coastal” or “maritime” climates,
is‘ comparatively free of the storm
centers brewing out at sea which move
into the coastline and dump as much
as 100 inches of rain a year on places
like North Vancouver.

The continental climate of the Yukon
is caused by the massive St. Elias
Mountains which are inpenetrable bar-

riers to all but the most vigorous storms
of the winter months.

Air in the Gulf of Alaska, heated by
the sea temperature of around 35
above, forms a “low” pressure area
which, as all such lows do, rotates
counter-clockwise in the gulf.

This tends to push warm air up to-
wards the St. Elias peaks and some-
times over them into the lower Yukon.

The Gulf was controlling the weather
like this, for example, on Christmas
Eve last year when Whitehorse ex-
perienced 37 degrees above, about the
same level that particular day as Las
Vegas, Nevada.

« ” But another pressure area, in this
Although breakthroughs of case the “high” mass of arctic air, is

ates Raut . Seda er Cake. normally active somewhat to the north
of Whitehorse and, since it moves in

horse in the southwest Yukon, the St. ; ‘ " that mata?
Elias range normally strips away the a clockwise ' direction, the “high
moisture and intensity of storms, shoves cold ar dows into the Yukou.
leaving only a body of moving air It is this counterbalance between
: two pressure areas that, although there
is an element of oversimplification
here, is the basic reason why the

Yukon weather operates as it does.