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For
Fun: Questions & Answers

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What country gets the most snow and why? We've
searched and come up with no answers.
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This is a harder question than it seems. The problem is that
there are snow places in many countries, but the whole country
may not be very snowy. The US. for example, is less snowy than
Canada, on average -- by a lot. But there are places in the U.S.
that receive more snow than most places in Canada. So the question
is, are you looking for snowy countries, or just snowy places
in countries. The U.S. has a long history of measuring "inches
of snowfall" while that has not been a standard meteorological
measurement in many other countries.
That being said, where are the snowy places. Basically, the best
combination is the northern mid latitudes to southern high latitudes
(north of perhaps 40 deg N latitude but not all the way up to
the Arctic and close to a rich source of moisture (like an ocean).
Throw in some mountains to help squeeze out the moisture, and
then you're in business. There are snowy places in high mountains
in other parts of the world (Asia, for example) but snowfall generally
falls short of those areas that are closer to relatively warm
oceans. So some of the possibilities become the U.S. Pacific NW,
British Columbia in Canada. The areas of SE Alaska where mountain
ranges are close to the Pacific. Then head over to Europe -- the
Alps harvest a lot of Atlantic and Mediterranean Sea moisture.
The mountains of Norway get tons of snow. And so on and so on.
In the southern Hemisphere there are fewer candidates, but the
best is the southern Andes mountains, and the mountain ranges
of New Zealand.
You can pretty much narrow down the possibilities like this.
Then, perhaps, you may be able to find some specific data from
those locations.
--Answered by Nolan
Doesken
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Why is it so windy in Huerfano County?
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Episodic strong winds are a part of life for all
areas in the immediate
lee (just east of) the high Rocky Mountain chain. Most of these
strong
winds are relatively brief but severe associated with rapidly descending
air cascading over the crest of the Rockies and racing out to the
plains.
These "Down Slope Wind storms" are most common from late
autumn into
spring and accompany upper level disturbances in the strong winter-teim
jet stream.
Fort Collins, Boulder, Denver, Colorado Springs and Pueblo are
all prone
to these windstorm events.
There are a few "preferred" areas that see strong winds
much more
commonly. Particular topographic features along the Front Range
of the
Rockies make certain areas more prone to strong winds than others.
You
are in one of those wind zones. There are three topographic features
of your area that work together to produce a "wind tunnel".
A clue to
this tunnel is the location of the Great Sand Dunes. The long,
relatively straight and broad valley of the Huerfano River happens
to
run parallel to the strongest upper level winds that blow over
the
Rockies in the winter. The bend in the Sangre De Cristo Mountains
(and
the protruding Blanca Peak massive) channels the winds toward
Mosca Pass.
Mosca Pass provides a low pass for the concentrated winds to blow
through.
Then, on the eastern side is a long, broad and straight valley
headed
straight for the open plains. And thar' she blows!
This is not a year-round wind tunnel. From late spring through
mid autumn
when upper level winds are light, the Huerfano County winds are
not
strong. But as long as the upper-level "Westerlies"
are blowing, your
wind tunnel will often be working. One of the benefits of these
winds are
markedly warmer winter temperatures. Compare temperatures at Westcliffe
to those of Gardner on a breezy winter morning. The difference
can be
huge -- as long as you don't consider the wind chill effect.
Under certain circumstances winds can reverse and blow up the
valley.
When easterly "upslope" winds blow, the Huerfano valley
becomes a
preferred lcoation for heavy snows. In the summer, upvalley winds
create
preferred locations for thunderstorm development. The wettest
areas in
Colorado in July and August are often found in the Wet and Sangre
de
Cristo Mountains where these upslope easterly daytime winds converge
with
monsoonal winds blowing up from the south or southwest at mountain
top
level.
--Answered by Nolan
Doesken
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What exactly is a 100-year drought?
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A 100-year "***" refers to any event that
has a one-percent chance of
occurrence in any year at a given point. Probabilities like this
are
normally determined based on past historic data. 100-year events
have
usually been reserved for heavy rain amounts for a specified duration
(at a specified point or small local area) or peak or annual stream
flow
volumes at a particular point along a river or stream. Flood plains
are often designated based on estimated 100-year flood flow volumes.
The values of a 100-year event are area and duration dependent and
cannot
easily be generalized.
Based on statistical studies, you would like to have 200-400
years of
data in order to make a reasonable stab at estimating the magnitude
of a
100-year "***" In otherwords, there is quite a bit of
uncertainty in
many estimates of 100-year events. We only have about 100 years
of
historic observations of precipitation and streamflow, so we can
estimate
25-year events reasonably well, but our estimates of 100-year
events
are much less certain. For example, for Loveland the 100-year
rain
storm for a duration of 24 hours is currently estimated to be
about 5.0
inches and for a 6-hour duration about 3.6 inches.
One could do the same sort of analysis for drought. It is fairly
easy to
do for annual streamflow volumes, assuming the flow on the stream
has been
undisturbed for the past 100+ years (not the case on the Big THompson).
For precipitation it's a bit more difficult as there are infinite
possibilities on how to define drought based on quantities, durations
and
aras. But once you arrive at an acceptable definition, you go
through
the historic data and determine what the probablity of occurrence
of any
precipitation shortage over a prescribed period of time and a
defined
area might be. There would be a whole myriad of "100-year
drought"
numbers you could come up with based on your assumptions.
The Colorado Water Conservation Board has examined Colorado streamflow
records and can assign probabilities to annual and peak streamflow
volumes. From this, you could estimate a 100-year drought based
on single-year streamflow statistics. Likewise, the paleoclimatologists
studying tree rings could do the same. We have not tried to do
the same with precipitation at this time simply because of the
large number of potential combinations and the fact that no definition
satisfies all users.
--Answered by Nolan
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What is a river basin?
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This is simply the land area that could contribute
water to a river simply by natural gravity. There must be a clearer
and simpler definition than that, but I can't think of it. The South
Platte River Basin consists of all the areas from the crest of the
mountains (continental divide) where local water if allowed to flow
naturally by gravity without evaporating would end up in the South
Platte River. Thus Castle Rock is in the South Platte River Basin
as is Cheyenne, Wyoming and Estes Park -- as well as the cities
of Denver, Greeley, Fort Morgan, etc. that are immediately along
the river.
--Answered by Nolan
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What is snow pack? What is an average snow pack
for this time of year?
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Snowpack here in Colorado refers to the accumulation
of snow that graduallly adds up over the course of the winter, mostly
in our mountains. The water content of that snowpack is what water
officials monitor so closely since that relates closely to the amount
of water that will end up in our rivers and stream, reservoirs and
irrigation canals during the late spring and summer. The water content
in our mountain snowpack normally reaches its greatest value in
mid April and sometimes doesn't peak until late April or even early
May. Based on an average of over 70 monitoring locations in high
and moderately high snow accumulation areas of our mountains, the
average snowpack water content is about 18 inches at its peak. This
year the snow pack water content reached its maximum in late March
at about 10 inches (again, remember this is just an average of about
70 or more individual monitoring points in Colorado -- depending
on where you measure, you get a different answer -- but as long
as you measure at the same places every year then you can compare
one year to another). Snow has been melting steadily since then
and as of today the statewide average snow water equivalent remaining
in the mountain snowpack was 5 inches compared to an average on
this date of about 17 inches. This infomration is provided by the
USDA Natural Resouces Conservation Service who administers this
snowpack monitoring program.
--Answered by Nolan
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What is stream flow and what does it measure?
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Stream flow is the volume of water (typically measured
in units of cubic feet per second to define instantaneous flow rates
or in acre-feet to define the total volume of water over longer
periods of time).passing a specified point along a river or stream.
In our state's system of water law, accurate measurements of streamflow
are critical for determining how much water is available to each
water owner. Hydrologists and engineers also track streamflows carefully
in order to know how large to build structures (bridges, culverts,
canals, dams, spillways, etc.) to safely convey water from snowmelt
and from heavy rains. Scientists have long established useful relationships
between measured snowpack levels and ensuing streamflow volumes
so that winter and spring snowpack measurements result in reasonably
accurate predictions of spring and summer streamflow from our mountain
rivers and streams.
--Answered by Nolan
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What is the annual average temp and annual average
precipitation for Colorado?
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This is actually a pair of numbers that we don't
pay much attention to -- since there is no place in Colorado that
receives the average temperature and average precipitation. That
being said, 17" of precipitation per year (rain and melted
snow) is a reasonable estimate. If you include the mountains (which
in Colorado, you must), the statewide average annual temperature
is somewhere between 45 and 49 degrees F -- you could use 47. But,
again, there is no place in Colorado that I know of where the average
precip. is 17" and the average temperature is 47 F, so this
is just an exercise in research.
--Answered by Nolan
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answers to this section.
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