Sledging forecast - post mortem
 

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This posting expresses the personal view and opinions of the author.
Something which everyone on this planet should be able to do.
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Everey good forecaster should always review their forecasts. That way they can
learn from mistakes. So just this once I will issue my own personal review of
the Dartmoor sledging forecast I issued last thursday. To refresh your minds
here it is again:

" On Friday 25th a strong to gale north to northwest wind will bring frequent
hail
and snow showers to Dartmoor, although the wind will ease back on Friday
afternoon. By the end of the day snow depths are likely to be 2-5 cms from 250
to 400m asl and 5-10cms above 400m asl. On the North moor north of the B3212,
and around Princetown, accumulations of 10-15 cms are possible in places above
500m on the high plateau. Considerable drifting is likely above 400m asl,
affecting roads. This easing on Friday afternoon as the wind decreases. For much
of the day conditions will be severe for walking above 500m due to wind chill
and occasional white-out conditions on the plateau, Unwell, inexperienced and/or
ill-equipped walkers will be at risk of hypothermia or even death if they get
lost in those conditions. Ice conditions are likely for a time on the Tors above
550m. Generally temperatures will have a maximum of 2 deg C at 350m falling to 0
deg C or less above 500m. Below 250m some temporary accumulations of 1-2 cms
snow are likely with maximum temperatures around 4 deg C.

Later on Friday night and during Saturday a thaw will begin with occasional
wintry showers of rain, hail, sleet and snow. Although a good cover of snow over
5 cms depth is likely to persist above 450m asl. Temperatures rising to above
freezing at all levels below 600m. Freezing of snow cover is likely on Saturday
night. Winds continuing to die down on Saturday.

A further spell of light sleet and snow is likely later on Saturday night
followed by a bright and fairly sunny day on Sunday with occasional wintry
showers. Continued thaw of snow below 500m asl with by then quite light winds.

Best time for sledging looks like Saturday morning. The runs at Hay Tor should
be open then, although the lower slopes will become icy and worn in the
afternoon. Good snow walking above 500m is on the cards for most of the weekend.
"

OK generally a reasonable forecast. Winds and showers died down a bit quicker
than anticipated on Friday and Friday afternoon was good for sledging on east
Dartmoor. Haytor was fantastic! I under forecast the snow at low-levels. Many
places not far above sea level had a good covering for a while. From 250-400m
3-7 cms rather than 2-5 would have been better. Temperatures were forecast too
high on Friday at high level! I did not get above freezing all day.Sledging
conditions at Hay Tor did indeed deteriorate quickly on Saturday afternoon.
Sunday had more showers than anticipated and Saturday had less. The snow depth
distribution was spot on with the west and northern moor having more snow than
the south and east. Princetown was cut off briefly on Friday and conditions were
atrocious at high level Friday morning. There was indeed good snow walking above
500m all weekend.

Will.
--

" Ah yet another day to enjoy "
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A COL BH site in East Dartmoor at Haytor, Devon 310m asl (1017 feet).

mailto:
www: http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm

DISCLAIMER - All views and opinions expressed by myself are personal
and do not necessarily represent those of my employer.
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