Mike Tullett wrote:
On Sun, 18 Oct 2009 11:14:48 +0100, Graham P Davis wrote in


Hugh Newbury wrote:

Will Hand wrote:

Min +1.3C in Haytor even (and we are not prone to radiation frost being
elevated).
Will, could you please explain this for beginners like me.

The ground cools through radiation as elsewhere and thus the air in contact
with the ground is cooled. However, the cold air then drains off the hill.

And it's in these conditions that valley bottoms can be several degrees
colder than hill/mountain tops at night.


Another factor occurs here. My house is on a slope towards the N and E,
so the garden sheds its frost in those directions (I purposely left a
gap in the hedge at the bottom of the garden). But the houses on the
opposite (South) side of the street prevent the frost leaving their
gardens and have complained the last few nights of the frost, which has
evidently piled up against their houses. QED!

Hugh

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Hugh Newbury

www.evershot-weather.org