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Old 06-12-2008, 07:48 PM
conchxpress conchxpress is offline
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Join Date: Mar 2008
Location: South Tampa, Key West
Posts: 244
Default Gust fronts and microbursts

Rick

I have one piece of equipment in my plane that I won't fly without. It's a Garmin 396 GPS that has XM satellite weather. It's not as up-to-date as on- board real time radar, which is quite expensive, but it does give relatively timely Nexrad radar information which is usually updated every couple of minutes. In addition it gives winds aloft, lightning strikes, cell movement, cloud levels, and individual reporting station weather, as well as severe weather alerts. Apart from the initial cost of the unit, the XM weather is 9.95/month. I can also get XM radio with it, just in case I get bored. It can function on battery power alone, and could be used quite easily on the beach.
I think the most worrisome thing that we as kiteboarders might have to deal with are microbursts and their associated gust fronts. Gust fronts happen to some degree with every mature thunderstorm, and it's the increase in a cooler wind that we feel in the face of an approaching TS. However, it emanates in a radial pattern from the cell and can be felt even if the storm is moving away from us. Normally the increase in wind is usually in the 10mph range. But with an entity called a microburst, conditions within the cell accelerate the downdrafts and the wind increase can be quite significant. Some gust fronts have been clocked at 168mph, but typically they are more in the range of 60mph with this type of phenomenon. As the gust front moves outward, friction from the ground or base causes the leading edge to roll upward causing a severe wind shear. How would you like to get lofted by a 60mph updraft? Microbursts were once thought to only occur with supercells, but now are known to occur with your run of the mill airmass thunderstorms that make up our summertime pattern here in Florida. Airmass TS are the result of the differential heating and cooling of the surface, and are not usually associated with a frontal line. The safe rule of thumb in flying is to give all thunderstorms a 20 mile buffer zone. They bring down Jumbo jets, so imagine one measly kiteboarder.

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