Some of you have been noticing a tendency for almost any gust of wind in the Atlantic to now become a named storm. Given this tendency, more relevant metrics are obviously the number of hurricane-days (and the closely related ACE index) and the number of storm-days.
I’ve scraped the data and done the YTD calculations, comparing these to the corresponding values to the end of September in previous years (I’ll replace this graphic in a few days when Sept 2007 is completed, but I don’t expect much change.)
At this point, despite a couple of intense hurricanes, 2007 is even quieter thus far than 2006.
Script for doing the update is at http://www.climateaudit.org/scripts/hurricane/update.hurdat.txt . Structurally it can update other basins as well, but I’ve only checked the current update against the Atlantic basin. This script requires hurricane.tab and Track.tab objects to 2006 which can be obtained http://www.climateaudit.org/scripts/hurricane/data/unisys . If required, I’ll modify the update script to work off these text files.
UPDATE: OK, here are corresponding plots for other basins. It didn’t take that long to do the calculations. You’d think that this would be available form the hurricane specialists with their legions of graduate students. The graphics pretty much speak for themselves. (In the early years for some basins, there are identified storms which often don’t have any wind speeds attached, which explains the appearance here.) The scales of these graphics are not uniform – the N Indian Ocean is much much lower than N Pacific and would be barely noticeable on a uniform scale.