Monday, January 21, 2013

Subsidence

The wind at Kahana was forecast to veer from the unflyable NNW flow to a more normal NE trade direction throughout the day. But the needle got stuck at due north. We hiked anyway, and lots of people launched, and scratched, and sunk. Sinking was pretty much the theme of the day. Except for one very lucky pilot who managed to get up at just the right moment, to claw his way up and across the bay, and soar over Kaaawa for a couple of chilly hours.

The forecast had mentioned that atmospheric subsidence would govern the conditions. I never know quite how that works, but it has something to do the air cooling and sinking and becoming more dense. And that's exactly what it felt like today! There was plenty of airflow but almost no lift! The air just wouldn't rise in any normal way. For the amount of airflow measured on the sensor I shouldn't have had to scratch as hard as I did to get up over the north bowls. Even once I was high up there were no thermals to turn in, just random chunks of air struggling to rise. The only organization of air seemed to be in shapes of wedges or shelves, and when I tried to turn I fell off or behind them. It was best to just skate along in those little shelves of lift. It was a very strange and interesting airmass.

In one sense, this was my favorite kind of day, despite the subsidence: super northerly, reasonably light, at least by the end of the day, sunny with nice high clouds, challenging to launch and get up and stay up. But in a more important sense, it was my least favorite kind of day: I was alone up there, and that makes it about half as much fun as it should be. Monday is supposed to be turning more NE through the day - I expect to have lots of company up there!

Today's roll call: me, FlyStrong, Jim, JeffMc, Gaza, Bonnie, Woody, Luis, Alison, Thom, Johnimo, Sandy, Roland, Oregonians Peter D and Bill, Allegra, RK Jeff, Jayson, Ginny, Tom P.

1 comment:

Thom said...

Thanks, I needed a coffee read just in time for third cup.

I got lured to KNA and watched you get high then McStalker got plucked off launch which entised VIPJayson and I to 'scramble' up (on two legs not 4 like someone else).

We got there to watch One-eye scratch and get pretty much the longest extended sledder. With bomb flights by OrPete, OrBill, FlyStrong, VIPJayson and Sidehill.

The King sucked up all there was in his anti-gravity machine and left nothing for his serfs.

A nice day but the snags on launch made think of top pasteurs of the Dill and wish they were here as well.