[ Post a Response | FLSC Message Board ]
Posted by Ray
on 6/26/2009, 8:18 am
69.205.81.50
Summary: Saturday will be excellent for winch launching and instruction, both morning and afternoon. As for soaring, no usable thermals before 1 or 2 PM, if at all. Will require high aerotow, preferably to cloud base. Sunday also will not be a good soaring day, with a system moving in. Models differ as to timing...best case scenario is if overcast comes in late in the afternoon.
Details: a good part of western NY has been drenched with over an inch of rain. So on Saturday, even though sunny, most of the sun's energy will be spent evaporating soil moisture, as opposed to heating the ground. Afternoon Cu's will surely form...essentially maritime clouds with weak lift except possibly right at cloudbase. This in spite of the fact that cold air with a favorable lapse rate will be advecting in. But the ground is relatively cold too. It is indeed possible to have strong boundary layer convection over water. That can happen only when the water has so much thermal mass that it can stay warm in spite of the incoming cold air. A perfect example of this is in September, when an outbreak of polar air comes out of Canada and bathes the entire eastern seaboard, and coastal water temperatures are still a couple of degrees from their maximum of over 70F. Then, satellite maps show, after a gap of 10 or 20 miles, Cumulus bands offshore from Maine to Florida, both day and night. It would be quite possible under those conditions to fly that distance, which would be a world record, in a properly instrumented and staffed two-place sailplane, especially with an aircraft carrier backup. Homework question: why the gap?
Ray
Message Thread:
« Back to thread