November 2024 Atmospheric River

The November 20-22, 2024 Atmospheric River dropped 11.65" in San Geronimo Valley compared to much higher amounts to the north. It was not as wet as the October 2021 storm (that dropped 12.67" in 36 hours causing San Geronimo Creek to peak over twice as high). But the 2024 storm lasted longer--it rained for three days straight (except for a break during the second night). It was so nice to see the sun again on the bright yellow fall leaves on Saturday! San Geronimo Creek peaked at 1,105 cfs at 2:15 pm on Friday November 22nd (at day 3 hour 14 on the graph below). The creek started at its late summer-fall baseflow of less than 1 cfs at the Lagunitas gauge, and as of December 1st is still flowing at 7 cfs. The peak flow was similar in magnitude to last winter season's highest flow in January. We already have about a third of our annual average rainfall as of the end of November, and our 3rd-highest to-date total since water year 2012. Along with over an inch of rain in early November, this has been a wonderful start to our rainy season.

Barnabe and Woodacre rain are reported about 10 minutes before and after the hour, respectively, but shown on the hour here (the hourly differences are mostly due to that). The x-axis is day.hour. 

Reconciliation

On October 26, 2024, the Alliance for Felix Cove hosted a reconciliation conversation between a Tamal-Ko (Tomales Bay Coast Miwok) family and a Point Reyes settler family. The settler family's ancestor, C.W. Howard--who owned most of the land on the west side of Tomales Bay--in 1887 hired Captain Henrik Claussen to evict all the Indians living on the west side of Tomales Bay. Their houses were destroyed and the people were forced to leave. One house remains standing at Felix Cove (Laird's Landing, used by the Lairds to ship dairy products to San Francisco 1860-1866). The last of the Felix family was evicted from their ancestral home by ranchers in 1952, and then later the ranches became part of the Point Reyes National Seashore--owned by all of us and managed for us by the National Park Service.

Felix Cove in 2020

Looking up Tomales Bay from above Felix Cove

The road to nearby Marshall Beach

The thought-provoking conversation included how family members learned of their ancestors' history and how they feel about it, complete with long-overdue apologies. It also included discussion of reparations--specifically, returning Felix Cove to the now landless (aside from a recently-acquired parcel in Nicasio) and federally-unrecognized tribe. You can support their efforts here.

Etcha Tamal, rematriated Coast Miwok Tribal Council
land in Nicasio (photo taken in 2015 after pile burns, and
prior to the 2023 purchase)

The conversation was relevant to all of us, since we all are either indigenous to the land where we live or from somewhere else, and many of us from somewhere else have ancestors who came here and displaced the indigenous people. It felt personal to me, because I too have ancestors that pioneered a dairy industry in the 1850s on stolen indigenous land. And it made me realize that I too would like to apologize for those actions. This is that apology.

"At some point, you have to decide, are you going to live in a world of abundance, open-heartedness, and open-mindedness, or are you going to live in a world of exclusion, isolationism, and scarcity?"

--Theresa Harlan, founder of the Alliance for Felix Cove, describing why she laughed at herself when contacted by a descendant of the Point Reyes colonizers

October 2024 Heat Wave

 The October 2024 heat wave was the warmest early-October weather in the Bay Area since 1980. Above average temperatures began for San Geronimo Valley just before the autumnal equinox, which was the beginning of 18 days over 80 degrees F, 10 days over 90 F, and 3 days over 100 F. Two of the days in the 90s occurred in September, then there was one cool day--September 25th, where the high only reached 69 degrees. After that there were 13 days in a row exceeding 80 F and 8 days in a row exceeding 90 F. In October, it had never been over 95 F before, but 3 days over 100 F and 3 days over 95 F set new October monthly records (since I started recordkeeping in 2012). October has now become a month when it can not just get hot, but really hot.

As with many heat waves, the remarkable thing was how warm it was at night above the inversion layer. In the graph below, you can see red and blue lines for the temperature on the ridges, and a green square for the highs and lows on the valley floor (with blank spots for occasional missing data). Starting September 30th, for 9 nights in a row, valley floor temperatures were below 60 F while ridgetop temperatures were in the upper 60s or warmer. And some nights were much warmer, with the ridges staying near 80 F all night! Who would have guessed that Marin County would have low temperatures in the 80s in October, rivaling Death Valley temperatures!

Death Valley-like nighttime temperatures in the 80s in Marin County

The third remarkable thing (after the extreme October heat and the heat above the inversion layer) was the short duration of each day's heat on the valley floor. Because the October days are shorter, the 50-degree temperature uptick was packed into fewer daytime hours. On multiple days I would be cold all morning, then go outside in the afternoon to warm up, then get too hot. Inside our house, temperatures never got above the upper 70s, with some mornings starting at a cool 62 F. Another year (like 2017 or 2019, when nights were in the 30s and highs were in the 70s) we might have turned on our heat to keep our house warm, but this year the heat wave provided our house heating!

So while this October heatwave was extremely anomalous and concerning, the impacts were lessened on the valley floor due to the lateness of the season and the nighttime cooling. But the concerns are big ones--warmest October high temperatures ever, warmest October water temperatures ever, driest soils and vegetation ever, and the impacts to plants and animals on the ridges of seven days in-a-row of low temperatures in the 70s and 80s.

The California Water Cycle

 The causes of most problems are solutions. We rarely unbuild big things that we've built. Instead we layer on solutions--some of them big new things that create their own big new problems. Sometimes you gotta just take out the big thing that started the whole cycle.

Soil Science Joke

 Mono Basin Textural Triangle:

Note that in some lentic zones you might encounter loamy sand, sandy loam, sandy clay loam, or sandy clay. But there will be sand. In other areas you might encounter gravelly sand, cobbly sand, stony sand (not just near the dispensary), or bouldery sand.

Insurance

Last week, the Marin Open Space District created a "shaded" fuel break along a fire road in French Ranch. They chipped and bucked a lot of trees near the road, some of which had fallen during winter storms. They took out a good number of trees in the lower grassland, before you reach the forest. It feels a lot more open and sunny now. Forest management isn't always pretty, but in a couple of years things grow back and look a lot better. And the long-term context is that over the last 40 years (with no grazing, no fires, and warmer temperatures) the woody vegetation is spreading, slowly converting the grassland to coyotebush and Douglas-fir forest. Perhaps the management goal is to revert these transitioning slopes back to a grassland? Or more likely, with work only occurring along the road, it is to give vehicles more room and safety during a wildfire.

But now imagine someone cutting down your favorite shade tree in your local park. The loss of individual shade trees on the steep hot sunny hike up to ridgetop forest makes this hike less accessible to kids and elderly and less pleasant for everyone. On a recent hike with my daughter and her friend, they were tired and we stopped to rest at one of these missing trees before heading back down. Doing that hike today would be a hotter and sunnier and less-pleasant experience.

February (left) and July (right) photos show the loss of 25-year-old shade trees on a hot south-facing slope.

A young solitary Pacific Madrone (Arbutus menziesii) was cut down in a Marin Open Space Preserve last week.

Honorable Mention

 About thirty years ago, when I was at Cal Poly San Luis Obispo, I took an environmental law class. At the end of the class we had to write a brief and present it to a panel of volunteer judges in a real courtroom. The judges awarded students first, second, third place for the best briefs, and I had an honorable mention--for being clever.

The case we had to argue was a real one from our environmental law book--a developer had proposed a housing development in the Central Valley, and a raptor center had challenged it on various environmental and CEQA grounds. Our instructor was also clever--he assigned which side of the case we were to argue based on our opposite inclinations. Since I probably exhibited signs of populism, caring about good governance, and prioritizing environmental and people protection over developers making money at public expense, I was assigned the developer's side of the case to argue.

This put me in a difficult position. In a real job, I just would have rejected it--frankly, I felt the developer's case sucked. I saw no way to win, or even argue that side with a straight face. But as a student, I couldn't say no. I had to do it somehow.

Then I had an idea.