Tuesday, June 25, 2019

SkySight Wave Forecast...Round 2

Sunday offered another chance to fly wave.  Strong NW wind in Summer is not normally considered prime wave weather but SkySight was showing areas of more than 7 kts and going to altitudes over 32,000'.

My flight started off with a tow to the northwest in a cloudless sky (at least in our area).  The tow was in sink from the time we past West Fairlee.  I held on to the tow until we got to 5,200' hoping that we would find some good air but we never did.  I continued in sink for a few more miles to the northwest.  Finally, I made a big left turn to the northeast.  It wasn't until I got over Middlebrook 4-5 miles north of the airport that I finally found my first traces of lift and slowly worked into wave and up to 12,000'.  SkySight had predicted the bad tow and the sink during the first part of the flight (the box showing -0.8 kts shows where I turned around and headed northeast).  SkySight also showed wave right where I found it (the blue dot), over Middlebrook and Lake Fairlee.

Thinking I would head to Mt. Washington I headed towards Franconia trying to use ragged clouds as wave markers.  Once I passed Dean Memorial I fell out of the wave and was never able to find it again.  I spent the rest of the flight in turbulent, broken, rotory, frustrating lift.  I made it as far as the Mount Washington Hotel but at 6,000' I again chickened out (see last posting) and did not make the transition to Mt. Washington.

For this flight SkySight got everything right.  I got sink off of tow where SkySight expected sink.  I found weak wave near PM right where SkySight said it would be.  And I spent the rest of the day in a futile effort to find wave where SkySight said there won't be any.

I had looked at the SkySight forecast the night before the flight and I saw the strong wave prediction but I really didn't pay attention to the exact location they were predicting wave.  The strong wave was predicted to be in the Pemigewasset wilderness to Jackson NH.   From the area from Franconia to Mt. Washington it would have been very difficult to safely access the wave through the sink (especially with only 6,000').  This picture shows the forecast wave cross section for a line drawn from the MW Hotel to Jackson, NH.  It shows - 5 kts where we normally expect wave and +7 kts over Jackson, much further downwind than normal.  I guess we'll never know if this forecast is correct.

If I had paid more attention to the forecast maybe I would have tried to pick up wave behind Smarts Mountain, using Plymouth and Wentworth as safety airports.  I can get SkySight downloaded to my Oudie but I have to signup for SeeYou Cloud $59/yr.  Maybe I shouldn't be so cheap.

I also looked at a flight by Nelson Howe from GBSC.  He did a nice job of following the wave upstream for 4 wave cycles.  In this case SkySight seems to have predicted the wavelength to be twice as long he found:

1 comment:

DG said...

Nice flying and comprehension of weather, Tim.