Diurnal variation in pressure
 

Rather unusually for this part of the world the diurnal variation in
atmospheric pressure is clearly identifiable on today's pressure trace.
Pressure fell to 1018.2 around 0400z then rose to 1019.5 at 0830z. It
then fell to 1018.3 at 1530z. At the time of typing this (1925z) it is
rising through 1019 again.

Interesting to see this phenomenon as it is usually completely swamped
by the dynamic pressure changes in our latitudes. Very run-of-the-mill
in the tropics, though.

Norman.
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England