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2024 Tioga Road opening date prediction

Spring has sprung, flowers are blooming, and my thoughts turn to when I’ll be able to drive through Yosemite and see Tuolumne Meadows again!

This year the April 1st measurement of snow water equivalent (SWE) in Tuolumne Meadows is 19.9 inches. My model of the Tioga Road opening date as a function of SWE predicts that the road will open on May 22 this year, with a 50% chance that the actual opening date will fall in the May 16 – 28 range.

This year’s prediction is a full 2 months earlier than when the road opened last year, July 22nd.

As before, I’ve excluded a bunch of years (grey dots and numbers on the graph) because of various management and Park operations issues. So the model and reported averages are all based on the black dots and years only.

Snow data here: https://cdec.water.ca.gov/reportapp/javareports?name=COURSES.202404

Tioga Road opening dates here: https://www.nps.gov/yose/planyourvisit/seasonal.htm

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Phase 2, Ackerson Meadow, Yosemite

Just announced: We’ve been fully funded to complete the restoration that we started last year! It was a lot of work helping to oversee the 3.5-month Phase 1 restoration but the job isn’t done. Planting this spring, another 3.5-month earthwork push this summer/fall, more planting spring 2025, and then probably some maintenance over the following few years. This has been years in the making, this is really about phase 5 out of 9 or 10! https://www.gov.ca.gov/2024/03/13/california-distributes-50-million-to-boost-salmon-population/

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Hot off the press: 20 years of research in Yellowstone

I started my professional ecological research with my Masters project in Yellowstone National Park more than two decades ago. During that project I helped establish the long-term research plots and data collection methods that led to this just-published summary of what happens when willows are protected from browsing and have extra water provided by simulated beaver dams.

As we hypothesized, the small streams in Yellowstone that used to support resident beaver for centuries, but lost them in the 1920s-1930s, have not seen a rapid recovery of willow just because wolves were reintroduced in the 1990s. Nor have the beavers returned in significant numbers. The impacted ecosystem, where streams eroded through the long-abandoned beaver dams and dried out conditions for willows, needs more than just reduced browsing pressure to recover.

Here’s a TikTok-er doing a good job summarizing our paper: https://www.tiktok.com/@natureexperienced/video/7331856319521017119

@natureexperienced

Read the paper! “Does restoring apex predators to food webs restore ecosystems? Large carnivores in Yellowstone as a model system” in Ecological Monographs. #Wolf #Yellowstone #Wildlife #Biology #Ecology #Science #Beavers #Nature #Research

♬ original sound – Nature Experienced

Click image below to go to free online paper:

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2023 Tioga Road opening prediction

It’s that time of year again to guess when the Tioga Road will open!

The 2023 Tioga Road opening date prediction is July 8th,

with a 50% chance that the real opening date will fall between June 30th and July 17th.

This is based off of the WHOPPING 62.5″ of snow water equivalent measured at the Tuolumne Meadows snow course for the April 1 report.

This huge winter has presented many challenges, this prediction included. For the first time since I started this in 2018 I need to extrapolate, to make a prediction outside of the range of existing data. I’ve ditched the linear model, since it doesn’t make sense that added inches of Apr 1 snow will have the same effect on road openings from May to July. As a snowpack lingers into June, those extra inches will melt away much faster than they did in April and May. So, I switched to a Gompertz function that has a lower and upper asymptote, which seems like a much better model for how snowpack affects getting a road open.

Snow data here: https://cdec.water.ca.gov/reportapp/javareports?name=COURSES

Past Tioga Road opening dates here: https://www.nps.gov/yose/planyourvisit/seasonal.htm

Data excluded from the model are the grey dots and dates on graph: 1995 and earlier, due to significantly different wilderness and safety regulations; 2020-2022 due to covid impacts to Park staffing and operations.

I’ll post the R code to Github if anyone wants it.