"Tom Bennett" wrote in message
...
This morning I noticed a large, fairly low-flying, 4- engined
passenger
jet go overhead through a clear blue sky (it appeared to be still in
takeoff mode from Stansted).

What immediately struck me was that it was creating a large sheet of
condensation (?) in its wake, the sheet forming a delta shape, with
the
apex somewhere just under the body of the aircraft. The condensate
only
lasted a few seconds before it evaporated, but the continuous
production
of it looked as if the plane was trailing a large white sheet behind
it.

.... see the FAQ Q/A 2A.11

I've actually seen military aircraft with full fuel load (having
difficulty lifting clear by the end of the runway) just after dawn (high
RH ... 96%), actually feeding into a pre-existing sheet of shallow fog
(MIFG) and temporarily thickening same to 'proper' fog (BCFG), though by
the same token, the wake of the a/c then causes turbulence which mixes
down unsaturated air from just above the fog layer and the entire sheet
disappears!

Martin.


--
FAQ & Glossary for uk.sci.weather at:-
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