On Wednesday, September 18, 2013 2:17:13 PM UTC+1, exmetman wrote:


As you can see from the results, the chart shows a peak in mid-January that erratically diminishes to around 50% at the beginning of June. This remains fairly flat till the second week of August when it begins to steadily increase up until the beginning of December when it flattens of a little. There is no real sign of any surge in the Gale index at the exact date of either the spring or autumn equinoxes, but there are minor peaks at around the 1st of March, and in the first week of October, that come closest to the dates of the equinoxes.



So no real sign of any equinoctial gales in either spring or autumn, just a steady decrease in the daily frequency of gales in spring, and a steady increase in autumn.



Bruce.

CEP Brookes, writing in his 'English Climate' 1954, says of the Autumn equinoctial gales:

'There is often a stormy period in mid-Sept, with a peak date of the 20th. The belief that a violent storm may be expected about the Autumn Equinox goes back at least to Shakespeare's time (Macbeth) and though its origin is not definitely known, it is not improbable that it was brought back by sailors to America, for it happens that West Indian hurricanes are most frequent around that date'

However, Brookes regarded the Spring Equinoctial gales as a complete myth.

Dick Lovett