On Wednesday, November 11, 2015 at 11:18:02 AM UTC-2, danlj wrote:
I am researching shear wave and thermal wave.

For example, the WI glider altitude record was set by Ted Clausing in thermal wave.

For example, on 4/24/98, bases were 7000 msl, thermal wave took gliders to 16-20,000 msl over lower Michigan, and stacked lenticulars were seen.

If you understand how to predict where shear and thermal wave will occur, I'd be delighted to hear about that!

In any case, if you'll send me dates/locations of thermal-wave flights, and altitudes achieved, and a bit of story about the conditions, this would be wonderful. Attaching a log file would be a bonus.

Send to: dleroyj AT gmail.com

Thanks!

DrDan

Yes, thermal wave or convective wave! Neat! Where I fly, on the Canadian prairies, 500km downwind of the mountains and at least 300km from any substantive foothills, we see wave clouds occasionally (several times per season), and some times manage to contact the lift. The technique is to climb normally in a thermal till right snug up against the cloud, and then press forward into wind. Just upwind of the cloud, with luck, will be that magical smooth smooth laminar wave flow and up you go climbing the face of the cloud using the classic wave climb figure 8 pattern.

Sometimes we just see lennies appear in one quandrant of the sky or another, either in some messy relationship to the cumulous clouds or, occasionally, clearly capping or bisecting a particular cu. More dramatic are the days, typically a day with a brisk wind aloft, perhaps 20 knots, with excellent streeting fully developed, when, within what seems a blink of an eye, the clouds re-orient themselves 90 degrees to form a series of bars across the wind. This happens mid to the later part of the afternoon.

Good climbs are rare, but do happen. Unfortunately, I do not have any electronic examples. I saw one barograph trace of a sustained gentle climb over a period of about an hour and a half. On another day, three of us noticed convective wave northwest of the field and headed up there. That evening, one of my friends was particularly animated, reporting having climbed up and over the cumulous reaching "harruumpp-tin thousand feet". Despite his overwhelming need to clear his throat at the critical juncture, I am pretty sure I know what he was trying to choke out - if it would be useful to your research I could pass it on by private email.