Poster: A snowHead
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Great newsletter...but what's a 'long reach easterly?
(I get the 'easterly' - but 'long reach' )
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Long fetch easterly refers to the distance that the source air has travelled to reach here. Siberia is a long way away but it’s a fairly unobstructed route at this latitude. Hence long ‘fetch’.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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Great read.
However I believe you're confused about the term 'fetch'.
The 'fetch' describes the distance and time frigid, Arctic air travels over a relatively warm body of water, not the combined distance of travel over a cold continental land mass plus a body of water.
Easterly flows like 'The Beast from the East' typically peter out at between 20-30 cm per storm event due to the short 'fetch' of the North Sea. The snow is cold and dry and is usually accompanied by high winds, which can cause significant drifting.
Typically it's the wind deposited snow which creates a large base depth not the absolute amount falling from the sky.
In comparison, the Great Lakes region of the United States and the western coastline of Japan can receive 1-2 m of snowfall in a snow event because the frigid air has more time & distance to 'fetch' water vapour.
In the Great Lakes case, the effect diminishes over the course of the winter as large tracts of the body of water freezes over.
Japan on the other hand can see between 15-20m of annual snowfall each and every winter because the body of water - the Sea of Japan - remains relatively warm and the westerly flowing Siberian air mass remains cold enough for the majority of the winter.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Japan looks to be quite a good comparator. The sea of Japan looks similar in width to the North Sea. Clearly we don't get the enormous falls that northern Japan gets but with true long fetch easterlies we do get big build ups over the Pennines as witnessed this winter.
The main difference is our distance from the truly cold air in Russia, but there are no obstacles in the way !
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You'll need to Register first of course.
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Peter S wrote: |
Japan looks to be quite a good comparator. The sea of Japan looks similar in width to the North Sea. Clearly we don't get the enormous falls that northern Japan gets but with true long fetch easterlies we do get big build ups over the Pennines as witnessed this winter.
The main difference is our distance from the truly cold air in Russia, but there are no obstacles in the way ! |
Please reread the above.
The 'fetch' between continental Europe and the Pennines - the North Sea - is fixed, as is the 'fetch' between Siberia and Western Japan - Sea of Japan.
Cold air normally flows west to east, that's why events like 'The Beast From The East' are rare and snowfall during Japanese winters is pretty consistent.
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