Hi.
BBC weather, anything with isobars on, I can also make my own weather map from the shipping forecast if need be.
A trick I employ if diving for a long period, maybe a long weekend is stick your back to the wind, then stick your left arm out, this will roughly point towards the center of a low, as the low moves past the direction of your arm will change, from this you can judge where the low is and what direction you can expect the wind direction from. High pressure usually has winds revolving clockwise, but it usually not a problem in summer as high's are usually light winds and good weather.
A low usually has wind revolving round a low in the Northern hemisphere anti-clockwise, and clockwise in the Southern hemisphere, this is known as the Coriolis effect, where the equator revolves round at a relevant greater speed to the poles.
E.G.
If you had a bath of water drop some ink in, then pull a stick along in a straight line you would see the same effect with the swirling eddies.
I think the water going down the plug hole anti-clockwise scenario is a load of tosh, unless you no different
