Now that the NHC has taken to naming every thunderstorm as a tropical storm, a new index of hurricane intensity has emerged. It's called Accumulated cyclone energy , or ACE for short. ACE is a measure used by the National Oceanic and Atmospheric Administration (NOAA) to express the activity of individual tropical cyclones and entire tropical cyclone seasons, particularly the Atlantic hurricane seasons. It uses an approximation of the energy used by a tropical system over its lifetime and is calculated every six-hour period. The ACE of a season is the sum of the ACEs for each storm and takes into account the number, strength, and duration of all the tropical storms in the season.
ACE was a dud for the 2007 and 2008 hurricane seasons in the US which is why you see these headlines --- Global warming causing more tropical storms: NASA, Which are just outright lies. Now every wiggle on the radar gets a name as soon as it widdles.
I point you to the history of hurricane spotting for comparison purposes. The largest USA hurricane disaster was the 1900 Galveston hurricane which made landfall at the city of Galveston, Texas on September 9 , 1900. It had estimated winds of 135 mph (215 km/h) at landfall, making it a Category 4 storm on the Saffir-Simpson Hurricane Scale. The first warnings to the beach goers on Galveston beach came just hours before landfall.
Similar no warning hurricanes made landfall in the USA up until about the 1960s when radio observations from ships became more reliable. Another big jump in hurricane tracking came in
October 16, 1975, when the first satellite under the GOES program was launched from Cape Canaveral, FL.
Remember this -- When you talk about hurricane number and intensity tracking, you are talking about observations during the last 60 or so years of the planets 4.5 billion years existence. Anyone will tell you, that is not a very valid statical sample of anything.
Saturday, December 20, 2008
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment