Thursday, May 20, 2010

Re-Thinking Past Flights

Here's my track log from last years Owens Valley trip


It was memorable for many reasons, one of them being the unconventional crossing (or so I think). Prior to reaching the Wall where many crossings are made directly to black mountain, I found myself drifting out into the valley while climbing in a thermal. My drift rate was 10-15 mph, and it was turbulent. I knew the westerlies had kicked in and knew sticking close to the Sierra's was no longer an option unless I wanted to get upside down. So I took the thermal to the middle of the valley.

I cross where the east side of the valley get's low as the Inyo's stop and the White's begin. These low hills didn't look like a good place to cross too, so I worked whatever lift I could find. What I found was light but consistent lift in the center of the valley between 10,000 and 12,000'. I worked this lift, spending about 20 miles flying up the center of the valley, slowly drifting east towards Black. At the time I thought I was lucky to find thermals in the middle of the valley. Now I have a new thought.

Peter L gave a talk on flying the Owen's at this weeks WOR meetings. He has a theory that when the westerlies come through, they push down the back side of the Sierra's and into the valley. This creates a convergence and a line of rising air in the valley. This makes a lot of sense with my flight. I think as the west winds continue to push through, that convergence line will move east, just as my flight did.

It's interesting to re-think an old flight and understand it in a different way. This seems like a good one to keep in the play book and remember that you may want to look for lift in the center of the valley if the westerlies have arrived.

1 comment:

joe jackson said...

Interesting. I've often had surprising "luck" burbling north along the highway. Never had a coherent theory as to why, but will keep this in mind.