In article
,
Scott W writes:
Are the seemingly constant changes to forecasts, sometimes just hours
ahead, being caused by the fact that the Met Office very rarely has to
cope with predicting snowfall? I would guess that the same event in
summer, under similar environmental dynamics, would lead to forecasts
of heavy thundery rain - some places would get a deluge, others less
so, though people would not bat an eyelid because they would just be
happy to know that there was a "chance of heavy rain".
Does the fact that there are now far fewer official met office
observers also play a part?

I imagine that snow is probably the most difficult weather element to
forecast. Not only do you have all the factors involved with forecasting
rain, but you also need to get the temperature and humidity profile
right, not only at the surface but all the way up to the clouds that the
snow is falling from. A few tenths of a degree can make all the
difference.

There can be great differences in conditions over remarkably small
distances on occasion. On the morning of the Tuesday before Christmas, a
friend reported that he had driven through heavy snow about six miles
away, while here we had rain. Also the difference between 3" of snow and
6" of snow is very obvious, while people are unlikely to notice the
difference between 0.3" of rain and 0.6" (and of course rainfall amounts
aren't normally forecast in figures unless the expected amount is very
large).
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)