October 10, 2019

Triumph in Northern California

This was a historic day.

Today there was a major Diablo wind event in northern California, with winds gusting to 70-80 mph from the northeast in favored locations.

But no major fires were started.  No cities or town burned down.  And there were no wildfire deaths.

A major achievement.

In comparison, two similar events in 2017 and 2018 killed dozens of people and caused tens of billions of dollars of damage.

The big difference?  Pre-emptive power outages by PG&E.

The winds were formidable and the relative humidities were low.

To illustrate, here are the maximum winds since midnight around the Bay Area ((October 10, 2019).  One can spot maxima of 73, 77 and 75 mph, with lots of wind about 40 mph.

The west slopes of the Sierra Nevada were windy as well, with winds gusting to 40-50 mph on the mid-slopes of the western side of the Sierra Nevada.

High-resolution weather prediction models correctly predicted the evolution and magnitudes of the winds, including the CANSAC model system run by DRI in Reno, Nevada (see below for 8 AM this morning) and the NOAA/NWS HRRR model.  Just as important as forecasting the strong winds, was the prediction that the winds would weaken during the afternoon, allowing power to be restored.

The avoidance of disaster today was particularly impressive, consider the wet winter and spring led to bountiful growth of flammable grasses.

Increasingly skillful weather forecasts are on the front line of protecting people from natural hazards, be it wind-driven wildfires, hurricanes, floods, and strong thunderstorms. 

Such excellent predictions do not replacement the hard work of making our civilization better adapted for the natural environment, such as ensuring that folks don't live in vulnerable locations (urban-wildland interface, vulnerable coastlines, unstable slopes and more) or properly taking care of tour coastal zones and forests. 

But good forecasting is a potent tool and can buy some time to complete the infrastructure changes needed to be resilient to extreme weather in the natural world.

Update:    Strong Santa Ana winds in southern California have resulted in fires growing last night.

My blog on UW College of the Environment Censoring of Social Media is Here.


  1. Very impressive, Cliff. I remember when you wrote about PC&E shutting down power with connection of forecasts. It is real progress!

  2. Surprising good news. Especially given the heat the media was putting on the utility supplier with stories about people suffering due to no power

  3. Thanks for your perspective Cliff. I live in the Berkeley Hills, and it never did get windy here, but we had power out and UCB was shut down.
    I see from the map that 75 mph winds were just 20 miles away on Mt Diablo. Humidity of 12% is impressive this time of year (or anytime)!
    PG&E has an impossible task, wrong if they do too much, or too little.
    We certainly need to change the infrastructure in a major way.
    I wonder if it would be feasible to place anemometers all along the grid power-lines for real-time localized monitoring. 10,000 of them, for more accurate triggering.
    The loss of electricity has a huge impact on life- from lost food, cancelled surgeries, traffic gridlock, etc. I had to call in backup from out of state for my emergency service job.
    But I am very grateful for no fire.

  4. The NW regularly has east wind events, including the last few days. Are our winds slower or more humid, ad so not prone to cause powerline fires? Or does BPA do a better job of powerline maintenance?

    1. Humidity levels, vegetation moisture content and soil moisture content are all far higher here in the fall than they are in areas of California where these winds/fires have occurred. You're better off worrying about the cognitive dissonance displayed by every "Eco-conscious" western Washingtonian who has no qualms about spending hours every week idling in traffic because the area is criminally overpopulated for the infrastructure.

    2. I have to second "Seldom Seen". Had dinner with friends in Vancouver yesterday and it took them 2 hours to go 17 miles on hwy 205 from Clackamus to Vancouver at 2PM in the afternoon. Too many cars {people} f,or the infastructure.

  5. Another way to adapt our civilization to the natural environment would be to wind-proof the power lines.

  6. >..and people in California complained bitterly about having their power shut off! Just like they complained bitterly last year when the power wasn't shut off and the Camp Fire started and killed many people. You can't win! Better to be safe than sorry though, right? No fires is great.

  7. Have had friends in the area complaining of the power cuts, but I'd rather have them complaining than their properties burning and running for their lives.

  8. " ... such as ensuring that folks don't live in vulnerable locations (urban-wildland interface, vulnerable coastlines, unstable slopes and more) ..." It is widely acknowledged how difficult it is to persuade people this. Politicians get voted out if they speak truthfully on this. In fact they get voted out if they don't come up with federal funds to bail them out. We really would benefit with a bi-partisan committee to evaluate risks throughout the US, and what kind of insurance is needed to alleviate the costs of recovery. In Seattle not only should property owners carry earthquake insurance, but also the city and state should have some insurance to help cover infrastructure costs. Federal taxes implicitly cover a lot of this, but it would be better if it all were explicit. And have proposed plans for infrastructure recovery.

  9. You can wind proof all the power lines you wish, but you can't wind proof the trees and branches that will fall into the lines, even if you clear/cut the vegetation to the required distances. A 60 mph gust can lift and propel a broken branch quite far and hard into a power line as the lines are no match against a falling large tree stricken by drought or eaten by beetles.


    It’s been around since the early 1900’s - it’s called burying power lines. Unfortunately the utilities want to maximize profits so they refused to do it.

    1. Are people willing to pay double for their power so it isn't shut off a few days a year for fire danger? Burying transmission lines costs up to $5 million PER MILE! A good solution would be to work towards localizing power generation, reducing the need for long distance transmission lines.

  11. Burying power lines is rather wasteful because power lines which are in the air, use the air to transport excess heat away from the cables. On hot days power lines get very hot and the cables can sag with the expansion and heat. Underground cables however, cannot perform that cooling trick using the air and so they are de-rated. Could you live with a substantially decreased electricity supply. As a disclaimer I live in an area where summers can occasionally reach 114'F and I survive just fine with no air conditioning. Could you? Cheers. Chris

  12. I am surprised to see this post Cliff, I thought you were all about data on this blog! Pretty weak link to causality there, not supported by the data..

    Only about 10% of wildfire are generated by power lines I think. And whats the incremental mortality here..
    how many people died due to the power shut off?? How much economic activity was lost? Whats the full data driven cost-benefit analysis of this situation?

  13. Quote: "Such excellent predictions do not replacement the hard work of making our civilization better adapted for the natural environment, such as ensuring that folks don't live in vulnerable locations (urban-wildland interface, vulnerable coastlines, unstable slopes and more) or properly taking care of tour coastal zones and forests. "

    Cliff, I live in the Urban-Wildland interface and there are a whole lot of steps that can be taken that can mitigate the risk of houses burning down and loss of life.

    In addition to turning off vulnerable power lines during a windstorm, building with materials that don't allow embers to take hold and closing off soffits reduces risk. Also creating a defensible space around the house helps.

    I took such steps when I built my house and the fire crew that defended my neighboorhood during the Carlton Complex fire credited building material choices for why my house did not catch fire. The defensible space created a safer environment for the firefighters.

    Its worth living in such areas because its less noisey,less light ,less traffic, and less crime than living in the big city-suburb areas and Mother Nature lives in my back yard.

    Name one area to live that doesn't carry risk. I do agree we need to better adapt, however that has happened historically as we gain more knowledge and evolve.

    But that process sometimes seems slow as tragedies continue, some by our own choosing.

    Chris H.
    Heli free North Cascades

  14. A very good example of progress for the rest world. Admiration from Argentina

  15. Sorry, but it's hardly a "triumph" when, to prevent wildfires, a major portion of the state had shut down its power and take a billion-plus dollar hit on its economy. What next? Should we ban flying and gloat when there are no aircraft crashes? This isn't an intelligent fix. It's an indication of just how badly California has been run in recent decades. I'd only be impressed if the state formerly called "Golden" had the good sense to build a power distribution system that doesn't have to be shut down every time the winds begin to blow hard.


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

Thunderstorms Return to the Northwest

 Thunderstorms have been relatively rare this summer, but today will see some boomers over the Cascades and eastern Washington. In fact, the...