January 5, 2010

Soaring While Still on the Ground

Soaring is one of those activities where the anticipation is so great that it's hard not to spend your days daydreaming about it. On a recent trip from Harrisburgh, Pa to Binghamton, Ny I had an opportunity to do just that and I learn a lot in the process.

I left Harrisburgh at 11:15 on December 27th, had I been soaring it would have been a sled ride; but the air was crisp and clear and seasonably warm. I didn't think much about soaring until I saw the fist hints of convention around 12:15 near Pine Grove, Pa. This is where we introduce Weather Underground's historic data for the 27th in Scranton, Pa (the middle point of my journey). The data shows that the winds were between 6 and 16 mph, and the high was 43F with a dew point of 30F. At 12:15, when I spotted the first Cu, the temperature was about 39F. it was low, about 2500' agl appropriate for the temp-dew point spread. What was interesting was how fast the day developed. Here is a sequence of photos for the 1.5 hours following the first Cu spotting.

Pine Grove, Pa - looking north at 12:15

Minersville, Pa - Looking west at 12:45

Hazleton, Pa - Looking north at 1:30

Looking at the photos, it is interesting to see how quickly the day developed, and how much development there turned out the be. The south west wind formed streets on the predominately SW to NE running Appalachian mountains helped by the low sun angle all day. What is missing from the photo sequence is how quickly the day ended. The historical data shows the peak temperature of 42F at 1:00pm with a quick drop after that. By the time i arrived at my destination of Binghamton, Ny the day was well over.

While I was watching the clouds, I used the opportunity to run a number of different experiments. The results were obviously difficult to verify but by not having to worry about flying the airplane (only driving the car) I was able to spend to time thinking what I should be thinking while flying. Here is an example: in the second picture, how would you get from your current position to the best cloud, which is the best cloud, and what is the expected thermal strength under that cloud? These are all questions that the best pilots will know how to answer, using this light workload time to think about how to answer them is time on the ground that is time well spent.

If you are interested like me, there were only 7 flights in the US on December 27th, 6 were in California/Nevada and 1 in North Carolina.

Keep soaring - even if it's on the ground,

1 comment:

  1. Hi Michael, thanks for visiting my blog and linking it - I have reciprocated! Interesting site and I plan to spend some time here soon reading through the theory sections. Neat shots in this post of the day developing as you drove. I had a similar experience today out at my club's field at Camden NSW Australia.

    Day started with the usual blue hole over the field which was substantially larger than normal (pretty much horizon to horizon). On my morning flight I could see some Cu's beginning to form some distance away to the south and west.

    On the ground I watched the day change shape. It was very hot (42-43C) and after about 11.30am the Cu's advanced towards the field as a high light Cirrus dissipated until by 2.00 pm they were widespread and lift was everywhere. It was interesting to watch streets of clouds begin to form from mere whisps.

    At one stage at around noon the Sun had a huge halo with a darker centre and later as I was launching the Junior I looked up to see a sort of horizontal wavy rainbow high overhead, almost like the southern lights. Must have been a mess of ice particles up there or something. Wish I'd got some shots...

    cheers, smith