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Thread: Wave Watch: Fri March 31 (SF mission)

  1. #1
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    Wave Watch: Fri March 31 (SF mission)

    The forecast is tracking for a north wind wave day, all day, this Friday. I saw this setup on the 16th day of the 16 day forecast charts, so noted it, but didn't say anything as it was so far out. However, it did prompt me to make the March 14 post about the task to San Francisco & return:
    https://www.williamssoaring.com/news...-San-Francisco

    Further, in talking with John Cochrane who'd fly his ship with me on this mapping mission:
    Goal #1 is to prove that the Kenwood, Petaluma and Novato waves are there,
    Goal #2 is to the confirm a Bolinas wave or similar in the area,
    Goal #3, once #1 & 2 are accomplished, is to return to St Helena, then down the Napa valley wave to Mt. Diablo, and return to WSC.

    A big "wishbone" pattern. If we do all three it'll be about 6-8 hours. Other pilots welcome, so top up your O2, dress warmly, and be ready for a long time in the air.

    Setup:
    - The good news is that the wind looks to be steady in direction and steady increase in speed up to 60 knots @18K, as opposed to last year's April 30 SF flight where the wind spiked from 40 to 75knots from 15 to 17K.
    - The wave looks to work all day, unlike last time, when winds suddenly died off around 2p.
    - The so-so news is the the direction down low is about 010 @850mb, not the 020 of last year's SF flight. This may affect the wave quality & location.
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    Will report further as we get closer. If this forecast holds, then no need to launch at dawn, rather a more civilized 9:30a launch. Sunset will be 7:30p, giving a 10 hour flight window. I plan to arrive Thu afternoon to setup.
    Kemp
    ASH-25 (FNX)

  2. #2
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    Re: Wave Watch: Fri March 31 (SF mission)

    Tue morn update, 3 days out. Forecast staying very consistent, wish it were more easterly, but it is what it is:

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    Still looks best at around 10p Friday evening. Tonight's RASP will confirm.

    I also have a Delorme InReach that I'll bring on the flight, will post the link on the tracker page.
    Last edited by Kempton; 03-28-2017 at 12:47 PM.
    Kemp
    ASH-25 (FNX)

  3. #3
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    Re: Wave Watch: Fri March 31 (SF mission)

    Kempton and Russell are preparing to launch.

    You can follow their adventure: https://share.garmin.com/KemptonIzuno

    John Cochrane http://share.findmespot.com/shared/f...X0eFPstVrBmS1D

    Current surface winds are 30+ MPH
    Last edited by Noelle Mayes; 03-31-2017 at 01:51 PM.

  4. #4
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    Re: Wave Watch: Fri March 31 (SF mission)

    Looks like they made down and back.
    Congrats !!!

    I was watching as John launched at 1039 AM
    thanks for posting the links.
    Peter Kelly

  5. #5
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    Re: Wave Watch: Fri March 31 (SF mission)

    Great flight guys! Looks like the upwind grind was hard.

  6. #6
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    Re: Wave Watch: Fri March 31 (SF mission)

    The wave adventure. I can now admit some skepticism about the whole north wind wave to Mt. Tam project -- and especially back! But, with plenty of good airports along the way, there was no question about safety, so let's give it a try. The wave was mostly 2 knots, though we took 1 knot here and there as well. Goat to 17.7, down to St Helena, climb in pretty much the obvious spots. Then downwind. Kempton had found bits of wave in the valley before. Wave isn't always one big waterfall; think instead of a stream flowing over pebbles. There will be lots of hard to forecast little bits of it. We kept bumping these, the last right over the petaluma airport. Then off to Mt tam / bolinas and ... nothing. Perhaps more searching around might have worked. The view was absolutely spectacular by the way. Then, a quick retreat with San Rafael and Gnoss airports in sight. And a good thing too -- rivers of 6 + knot sink that go on and on and on. Into a 40-50 kt headwind. But, Kempton had marked a good spot just west of Gnoss field before, so we went there, and lo and behold even at 6,500!, there is wave! That took me back to 16,000' and enough to push forward. After a somewhat benign glide to petaluma, I ended up doing rather classic upwind wave flying -- get every inch you can, dive through 6 + knot sink. (Speed to fly theory -- as fast as you dare, for me middle of yellow arc) Wait for it to get not so bad netto zero, slowly better, and then stop in the next climb. explore horizontally to find the best lift. Ponder how 6 knots of netto sink only produces 2-3 knots of netto lift. Repeat. On the trace, it seems I was working four downwind wave bars all off Mt St. helena. I did a little sideways exploration of the napa wave, which also seems promising. Everything would be more promising with 10 degrees more easterly wind! Kempton worked a line more over the napa valley, which produced less lift but also no rivers of sink. The trip home from St. helena was interesting too -- from 17.7 at St Helena, I found another river of sink to gold mine. Usually I cheer myself up with, "well if there is sink this bad, it must really be going up strong on the other side," but after a while of this, one's faith does get stretched. But it all worked out fine, with 5000' to spare back home. Do keep the possibility of huge sink in mind when flying wave! And the possibility of a downwind retreat.

    All in all, this is much more possible and benign than I thought. One big revelation, relative to looking at maps, is just how good the angles look. 17.7 at goat, Mt. St. Helena, or (some day) Tam, gives you 30 degree angles to airports.

    Thanks much to Kempton for organizing and encouraging, and to Rex and Noelle as always for making it happen. The traces are on OLC. Russ' pictures look a lot nicer than mine.

    John Cochrane

  7. #7
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    Re: Wave Watch: Fri March 31 (SF mission)

    John's pre-flight skepticism I could sense, but I also knew there was a good chance I could get him to push thru it. 8^)
    After all, if we can get more pilots to really push their limits, we can do really great things, like this flight!

    The forecast was pretty stable, but not as NE as last year's flight, which was very consistent from 030, whereas this flight was 010 or so:

    Click image for larger version. 

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    with the strength & quality fluctuating thru the day, best in the morning, weaker in mid-day, then improving to evening. Also the 500mb is not well aligned with the 700mb so we should expect fading lift with altitude, which is what the wind cross section predicted, and what we experienced:
    Click image for larger version. 

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    Nevertheless, I felt it was good enough. The original plan is outlined here:
    https://www.williamssoaring.com/news...-San-Francisco

    But as the saying goes,"no plan survives contact with the enemy". I thought I was flexible enough, but the day had other plans.

    Russ & I launch at 9:48a, a bit later than planned, thanks to several last minute prep glitches. Rex towed us to Goat, right over the creek at the bottom, entering from the side, avoiding rotor and pretty much a direct line from WSC. Off tow @ 8K or so, 4 knots to start, fading to 2 knots by 17.7K.

    Downwind to Mt. St. Helena, but only 2 knots at best. Feeling confident, we had off to the Kenwood wave spot to confirm it's presence.

    Nothing.

    Onto Petaluma, and 1-1.5 knots. Surely there has to be something at Novato, so we leave the Petaluma lift at 16,400.

    Nothing again.

    Now it's back upwind to around Gnoss Field where, over the marsh of the "S" turn of the Petaluma river, we work 1-3 knots up to 16,600. By this time John is nearing us, from the Petaluma airport direction. Don't have him in sight but both of us aim for the lee of Mt. Tam from Novato, view from 16K:
    Click image for larger version. 

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    Crossing over Stinson Beach at 15K, the views continue to be magnificent:
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    with the Farallones within easy glideClick image for larger version. 

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    Note the dirty outflow from the Bay on the left pushing out into the Pacific.

    But just like last time, no Mt. Tam wave, so little time to enjoy the view, it's time to retreat! The view at that point:
    Click image for larger version. 

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ID:	3703 Novato is the last decent lift, and is 20 miles into a 40-50 knot wind. We lose 7,500 ft in that 20 mile push upwind, about 16:1 glide. John was able to find lift fairly quickly at Novato, but as we experienced all day, the waves would come & go, not often repeatable. We did see John at this point, we hadn't sen him before, and went under him only 300 ft lower, and.... nothing! I can't explain it....

    John climbs out and Russ & I thrash about for over an hour! Later Russ said,"that was dire", to which I replied,"it wasn't dire, but we could SEE dire from there". Honestly, towards the end of that period, it was like, just try anything different! We tried areas such as the ridge on the N side of Lucas Valley (bottom of pic), which produced 1 knot or so:
    Click image for larger version. 

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    >> continued with another post as I've hit the 10 attachment limit
    Last edited by Kempton; 04-02-2017 at 03:49 PM.
    Kemp
    ASH-25 (FNX)

  8. #8
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    Re: Wave Watch: Fri March 31 (SF mission)

    Part 2

    If you look at the trace from 3p to 3:30p, that's our breakthru climb out from 8,500 to 13,500 starting pretty much over Gnoss Field, then followed my nose across the Petaluma river:
    Click image for larger version. 

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    thinking that "I'll just follow this lift until it dies off". Well you can see it didn't die off until way across the marsh! Gnoss Field is now 2 for 2 in terms of lift, this flight & last years.

    Heading north directly into the wind, we encounter lift and reduced sink into the wind, so I just keep pushing. We cover 24 miles directly into the wind, with only a couple of very short stops, and yet only lose 1-2,000 ft, black rectangles.
    Click image for larger version. 

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ID:	3706 I can't explain it....

    A couple of times when we hit lift, I do a 90 degree turn, thinking that with no clear trigger, that the wave would be orthogonal to the flow. This worked most times, but it was more efficient to keep pushing upwind.

    We're now within striking distance of Mt. St. Helena. John went from Novato to Santa Rosa, and that worked for him. He's well ahead of us around Mt. St. Helena, but it's not very strong. From near Kenwood we nose along to Mt. St. Helena topping out around 15K. At this point, one could have bicycled faster than we were averaging. But it's exploration, and not racing...

    We decide we've had enough and, with John's caution not to head directly to Goldmine from Mt. St. Helena, we go further NW, over the geothermal plants, then aim to WSC. Even with the wind and at 90 knots, we have 3-4 thousand excess to WSC, so we could have left Mt. St. Helena at 12K and be fine. We land a bit before 6p, clocking 8 hours & 1 minute. Ground wind wasn't bad at 12-15 knots.

    Lots to think about:
    - Don't expect much btwn Mt. St. Helena & Novato.
    - The Novato lift could be because it's at the end of the Petaluma valley, channeling the winds to a hydraulic jump point.
    - I characterize the Novato area as "that's where the fish are". I can't tell you where each fish is at any moment, but that's where they congregate....
    - Many times we'd be in lift at Novato, then turn to go back thru it, and it would be gone. Can't explain it...
    - We didn't have to dress as warmly as we did. Boots, ok, but not such a heavy jacket.
    - Talking with Ramy later, the theory came up that due to the strong NW winds parallel to shore, this blocks the "bounce" of the wave on the lee of Mt. Tam. Ramy's flight was in early January when there was no such flow, but I noticed this flow on the forecast charts for this flight & last years.

    Next time, the task is climb at Novato, leave @ 17K, forget the Tam wave & aim for downtown SF for the photo run (losing only 1,500ft), turn 180 & head back to Novato expecting to lose 9,000 ft on the way to Novato. There was some lift just N of Santa Venetia, so perhaps there's more lift out on the flats then we know. But it's psychologically tough to head out to the marsh for lift..

    Thanks to Russ for co-piloting with me (and being photographer, the pics are all his), John for actually doing the flight, and of course, Rex & Noelle for their continued support for boundary pushing flights like this.

    Watch for the next N wind day!

    OLC: http://www.onlinecontest.org/olc-2.0...htId=659583226
    For some reason OLC doesn't like my file.
    Last edited by Kempton; 04-02-2017 at 03:52 PM.
    Kemp
    ASH-25 (FNX)

  9. #9
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    Re: Wave Watch: Fri March 31 (SF mission)

    Kempton posted such a complete history of our flight Friday and lessons that I (co-pilot) will just add a few graphics to show some of the phases of the flight that I found challenging and/or interesting. The following are screen captures from SeeYou with graphics added using PowerPoint.

    The flight south was fairly straight forward so the first image off shore near Stinson Beach where John-BB and Kempton/Russ-FNX who have just turned north to return to Williams. We never saw each other until near Novato.
    Click image for larger version. 

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    This image shows BB and FNX in the same area with 900’ elevation difference. 33 minutes later BB is 14738’ MSL and FNX 8576’. Even Kempton can’t explain this.
    Click image for larger version. 

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    This image shows how close we were in the Novato area with BB climbing and FNX barely holding altitude. We had BB in sight at this time and it looked like we were right below, but apparently a little too far south.
    Click image for larger version. 

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    This image shows how much Kempton/Russ-FNX wandered around for two hours before finding enough lift to proceed north.
    Click image for larger version. 

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    This image shows the difference between downwind in sink compared to upwind in sink. The northbound position shown is 5 hours later and 4000' lower, so the wind was probably somewhat different.
    Click image for larger version. 

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  10. #10
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    Re: Wave Watch: Fri March 31 (SF mission)

    Nice flying, and excellent reporting.
    Thanks
    Peter Kelly

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