In article ,
Janet Baraclough writes:
|
| | The danger of frost is often specific to certain
| | locations. Even within a matter of a few yards, frost
| | pockets can form in hollows, and up against fences and
| | other barriers to the free circulation of air.
|
| That phenomenon is relatively rare in the UK, as it applies only
| in very still conditions.
|
| I don't think so Nick, though living on the flatlands perhaps you may
| not see frostpockets as often as I do. Many gardeners (even in windy
| Scotland) with a hillside/sloping/valley garden will be only too
| familiar with frost pockets exactly as Michael describes, and they are
| very frequently referred to in UK gardening books.

Even in hilly areas, you will see the phenomenon I refer to more often.
Indeed, one might say ESPECIALLY in hilly areas! Frost often occurs
on hilltops and not on the bottoms, even when the adiabatic cooling
phenomenon is negligible, due to the effect of a freezing wind.

I know that books often refer to the frost-pocket phenomenon, but my
observation is that it is a lot rarer (in the UK) than is often made
out. Yes, it occurs, but it is nowhere near as common as the shelter
phenomenon, which is what I referred to in the section that you snipped.

Michael Adams was correct that the danger is very location-specific,
but a little misleading when he described the frost-pocket phenomenon
alone. The shelter phenomenon is a much more important cause of the
variations with precise location.


Regards,
Nick Maclaren.