Predicting Snowfall from Radar in Mountainous Regions

California recently emerged from a historic, four-year drought, thrusting the state’s system of water supply monitoring into the spotlight. Where does California’s water originate? Mostly the mountains, in particular, the Sierra Nevada range. The snowpack accumulates in the winter, then melts and flows into the Owens Valley, where it is carried by aqueducts to Southern California. The state of California tracks the depth of this snowpack carefully via a network of sensors, and occasional manual measurements by snow scientists. Unfortunately, these sensors are pretty sparse, leaving wide swaths of snowpack unmeasured. Continue reading

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The World of Rope Soloing

I used this method from SuperTopo to rope solo a 5.8 crack route today. A few things to make clear with this approach:

  • You’re not tied into the rope by a figure 8. Instead, you’re fastened to it with a Micro Traxion pulley. As you climb, the rope automatically feeds down through the pulley because it’s weighted with a water bottle (or a pair of approach shoes, or something else). The teeth in the Micro Traxion prevent movement of the rope in the opposite direction, thereby arresting a fall.
  • The rope is fixed at the top. An elegant way to do this is with a bunny ear figure 8 knot tied in the middle of the rope, and two locking carabiners.
  • The Micro Traxion is your fall-catcher, but you’re backed up by clipping into knots (alpine butterflies) in the other strand. If your Micro Traxion were to fail or the strand on that side broke, those knots would limit your fall to the interval between them. Clipping in and out of those knots can be tricky, but kind of gives a feel for climbing on lead and having to place gear with one hand.
  • Static vs. dynamic ropes. A lot of talk about how a static rope works better for rope soloing. I used a dynamic rope, my Mammut Infinity. The stretch was a little annoying, but overall didn’t seem to compromise anything.
  • Does the Micro Traxion shred the rope? Many people use them to rope solo, quite often two of them (one is primary, the other is backup rather than clipping into knots). A discussion on Mountain Project seems to conclude that only large falls of 5 kn or more would cause rope damage. So check that the rope is feeding through to minimize potential fall factors.
  • With the SuperTopo method, the strand with the backup knots can get stuck in cracks. This got annoying, so I’m looking into just using a secondary device on the other strand. Another climber mentioned the Camp Lift ascender. This is a toothless device, which, depending on whom you ask, has a lower potential to damage the rope sheath. One thing nice about it is that it allows movement of the rope in both directions, but will lock up if the movement is too rapid.

Overall, I really enjoyed rope soloing. With a partner, you forget how much time you spend just belaying. In a few hours I got 8 laps in, and got better at hand jams. This is definitely a great way to get mileage in alone.

Stock Project

As a personal project, I’m going to attempt to predict prices of stocks with low institutional ownership/influence with machine learning. Using the finviz screener, I’ve found 41 stocks that qualify under the following screener attributes:

  • Exchange: NYSE

  • Country: USA

  • Market Cap < $2b

  • Price > $5

  • Average Volume > $200k

  • Institutional Ownership < 30%

The next step would be getting the tick data (probably paying for it through eoddata.com) for these and high institutional ownership stocks (probably S&P 500) and looking at some statistical summaries (histogram of per day changes, sharpe ratio) of the two categories and seeing if they differ.

Standard Harness

I’ve settled on what items I always keep on my climbing harness (BD Momentum).

  • BD ATC Guide with pear carabiner. Common belay/rappel device with an autoblocking mode. Autoblocking mode is good for bringing up a follower at an anchor, since the autoblock works as a “progress capture” device that will hold the rope if you were to accidentally let go. It’s super easy to setup and requires one additional locking carabiner.
  • Metolius Alpine PAS, with locking carabiner. A personal anchor system is just a chain of strength-rated loops that you use to clip into an anchor. The individual loops make it easy to adjust the distance from the anchor, and provide some redundancy since you can clip into multiple loops. The Alpine PAS is a lighter version of the PAS. One thing to note, this can’t take factor 1 falls so you should tighten it up so that it is always loaded (Petzl Connect Adjust can take dynamic loads though).
  • 13.5 inch HollowBlock, with locking carabiner. Used as a rappel backup mostly. Why not a loop of cordelette? Mostly preference. The HollowBlock is a fixed loop with the ends stitched together as a bar tack. It’s made of this hollow sheath cord that grips extremely well as a klemheist or prusik, requiring usually just two wraps to hold. The absence of knots in the loop makes it slightly less fussy. I believe it’s lighter than most cordelettes. Downsides might be that you can’t untie it and use it for something else like anchor building, and that its rated strength is not as high as cordelettes I’ve seen.
  • Extra locking carabiner. Good to have for putting the ATC Guide in autoblocking mode.
  • Emergency locking carabiner.