Weather watch: Tidal disaster cancelled. High X saves Britain.

Have you been keeping an eye on the high tides chart? A curious astronomical coincidence has led to some of the highest tides seen in this country in the last 40 years. Every year in mid-September, when the moon is closest to the earth, tides are high. But this year we are also at the peak of a four-year lunar cycle and a 19-year cycle affecting the angle of the earth. Even the sun has been helping to produce a combined effect on the tides that reaches its height this morning.

Peter Burrows, Flood Defence Manager at the Environment Agency explains: "These very high tides in themselves don't present a threat. It is only if on top of these tides we get a surge because of adverse weather conditions that we start to worry."

The only ingredient missing from a recipe for disaster is high winds, to whip up the water and turn the high tide into a flood. The Thames barrier and other flood defence systems were ready to be put into operation, but it now looks as though it will not be necessary.

Thanks to a large and benign high pressure system (X on the map) which has settled helpfully over the British Isles, it looks as though we shall have only light winds for the next few days. Only a "yellow" precautionary warning - the lowest level of flood alert - has gone out in the south west, with the rest of the country considered totally secure.