IB Geography Hazards and Disasters

[Submitted by Marcelo Fonseca]

Posted at 11:35 AM ET, 08/19/2010 Forecasting hurricanes: Part 1 By Steve Tracton How good (or bad) are today's forecasts? * Sun & warmth: Full Forecast | Yesterday's rain totals * This is the first of a two-part series on hurricane forecasting. Part 1 details how reliable forecasts are expected to be when (and if?) the 2010 tropical season finally picks up steam. Part 2, to appear next week, will look at ongoing research into the development of tropical systems and the prospects for improved forecasts. Hurricane Fran, Sept. 5, 1996. Satellite image by NASA. As reported in an earlier post by CWG's Greg Postel, the National Oceanic and Atmospheric Administration's latest update of its 2010 seasonal hurricane forecast calls for a significant chance that the remainder of the season will be very active, perhaps one of the most active on record. Whatever the number of tropical storms and hurricanes -- collectively referred to here as tropical cyclones (TC) -- most seasonal hurricane forecasts justifiably caution that it's impossible to reliably forecast when and where an individual storm might develop, nor its intensity and whether it will make landfall, before a storm even exists. The specifics of genesis, strength, size and track of TCs fall in the domain of daily weather. As such, predictability is limited in theory and practice from a few hours to about a week or two at most (no one really knows for sure). These specifics, of course, are precisely those which are required by emergency managers who, for example, must decide if and when to order evacuations, and those which ultimately determine the impact of a TC on lives and property. So, what are the current capabilities and limitations in the accuracy and utility of TC forecasts? The foundation of the TC prediction and warning process is the track forecast. If the track forecast is off, so too will be predictions of other parameters, such as wind speed and direction, rainfall, and storm surge relative to landf