SNIP


After this morning's deluge (14.6 mm) my JJA total is 420.6 mm.

Does not compete with Haytor or Evershot but still likely to be a

record for Wembury.

It is amazing that Haytor has 240 mm more when it is only 40 km away

as the

pigeon flies.

Not only due to elevation clearly.



Weather systems have been doing funny things this summer.

I believe it is called ECWOLEXIT.

Enhanced Convergence Where One Least Expects IT

or,

Enhanced Convergence Where One Left EXITs

for the initiated.



Len Wood

Wembury, SW Devon, 83 m asl

I once got detailed rainfall figures from the EA for around 40 sites around Cornwall, most with 15 years of records, and then plotted average annual rainfall for various periods.

What became apparent was that the overwhelming controlling factor for rainfall variance (in Cornwall - nowhere near as much in Devon) was distance from the spine of the county, altitude being a very 2ndary factor. In fact if you had no knowledge of orographic rainfall and were presented with the map I doubt if you'd give any real thought to altitude being a significant factor.

A few examples:-

Culdrose (85m) 1961-1990 LTA 1032mm
Penzance (19m) 1961-1990 LTA 1140mm

Penzance being affected by convergence along the spine.

By far the driest spots are headlands, though over exposure (of the meteorological type, for the more interesting variety head for Pedn-Vounder near Porthcurno http://www.naturist-holiday-guide.co...favourite.html )can reduce recorded rainfall at these sites.

Nearby Porthcurno (55mm) therefore LTA 955mm, Lizard (also 55m) 805.9mm

Michaelstowe @ 114m on the NW edge of Bodmin Moor, but away from the 'spinal convergence zone' has an LTA of 1165mm, virtually identical to Penzance. Move to Altarnum, not greatly higher (167m) but on the convergence line, LTA 1581mm.

Sorry if your eyes have glazed over, I'm a bit of an anorak for rainfall figures.

Been mainly sunny here since 11:00 (now 16:45)

Graham
Penzance