orografic cloud

[bill-scott]

orografic cloud is formed when a damp airmas meets an obstruction and is forced over it resulting in
A: a drop in pressure
or
B: an increase in pressure

this is important theres a pint resting on it

[GlennP]

ask Wallis. He knows everything.

[gary stenhouse]

a drop in the air pressure causing low pressure to the lee of the hill

[ron freeman]

Bill, air (dry or moist) which is force up over a hill there has to be a drop in pressure due to accelerate air flow just the same as airflow over you wing

Orographic is moist air being cooled quicker than the normal rate.

[John Wallis]

Ask Glen he knows more than us all put together then again he 's never done owt so I maybe wrong for the first time................

Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and create clouds and, under the right conditions, precipitation.

[bill-scott]

I agree with all that john but the pint depends upon wether or not the air pressure drops or increases when an air mass is forced over an obstruction

[colin keightley]

It drops

[John Wallis]

Drops as Colin says think of a wing (Aerofoil) as air is pushed over it the air accelerates above the wing causing the pressure to drop

[gary stenhouse]

so who owes who a pint or will it be swordes at dawn to battle it out?

[bill-scott]

Neil is very conspicous by his silence on this thread