As can be calculated by counting up the alphabet to M, there have been 13 hurricanes so far this year in the Atlantic. The average is eight or nine, and the most active year this century was 1933 when there were no less than 21; this record is closely followed by 19 in 1995, the year whose brilliant summer here in Ireland made us believe that global warming had finally arrived.
Other high hurricane counts were the 18 that occurred in 1969, and the 17 that were noted more than a century ago in 1887. By way of contrast, there have been only two years since methodical records began when there were no hurricanes at all: 1907 and 1914.
The older figures on this list must be looked at circumspectly, because the advent of satellites in the last 35 years or so has made mid-Atlantic hurricanes much easier to spot. Although we had no way of knowing, it is possible there may have been even more than 21 in some forgotten hurricane season in the dim and distant past.
The potential of hurricanes to cause damage to life and property is rated on the Saffir-Simpson Hurricane Intensity Scale of one to five. The scale was designed in the early 1970s by one Herbert Saffir, a consulting engineer who specialised in wind damage to buildings, and Robert Simpson, a former director of the US National Hurricane Centre in Miami, Florida. Any individual hurricane may pass through one or all of the stages on the scale.
A hurricane at Stage 1 on the Saffir-Simpson Scale is comparatively harmless. It may lop a branch or two from trees and bring down some power-lines, but its winds are no stronger than 90 m.p.h.
By Stage 2 a hurricane will have winds of more than 100 m.p.h., and a few trees begin to fall. At Stage 3 the damage becomes relatively widespread, and affects buildings and other relatively solid structures, while Stage 4 brings winds to 150 m.p.h., with extreme damage and the doors and windows of buildings in the path of the storm being almost totally destroyed.
And Stage 5 is catastrophic: buildings in the storm's vicinity are devastated, winds exceed 160 or 170 m.p.h., and on coasts storm surges approaching 20 feet can be expected.
It will come as no surprise to those following recent meteorological events in the Caribbean to hear that Hurricane Mitch was a Category 5 hurricane on the Saffir-Simpson Scale. At its peak intensity, Mitch's sustained surface winds were estimated to be in excess of 180 m.p.h.