How fire scientist in charge of California power shutoffs uses a ‘time machine’
At PG E s weather lab in San Ramon Scott Strenfel studies a huge digital map on the wall displaying temperatures dew points and humidity levels across California At a spot in Kern Hills outside of Bakersfield wind gusts of mph were forecast to hit Hey company thunderstorm outflow down in Kern at p m Strenfel calls out to his fellow scientists each behind double computer screens You guys see it Related Articles When is your home safe after wildfire smoke California researchers have certain answers California to boost utility wildfire fund by billion Wildfire threats to California water guidance demand attention group warns Firefighters who drop from the sky to climb from ground in bid to save giant sequoias in Sierra from Garnet Fire Brentwood moves forward with new downtown fire station Strenfel leads PG E s meteorology operations and fire science group His job is to help prevent the utility s equipment from sparking catastrophic wildfires by progressing models to determine when to shut off power to customers We want to mitigate catastrophic fires he noted but we also don t want to overuse community safety power shut offs because we know it s our tool of last resort With September and October the height of California s wildfire season Strenfel s responsibilities are as he puts it pretty incredible Below is a newest interview with Strenfel edited for length and clarity Q Do you feel like when these big wind events come through there s this sort of race against time to make sure that these devastating fires don t happen again A Since - we ve definitely felt like we re on that treadmill and we re trying to run as fast as we can and develop the bulk scientifically accurate models that we can to mitigate the liability of catastrophic fires We never want to see that happen again not on our watch Q What should have been done differently to prevent the North Bay wildfires in A We ve got to remember that was seven years ago and so we ve made specific huge strides We did not have a citizens safety power shut off campaign And now we do We ve really built up a content science and analytics company within PG E and the meteorology department and so pretty much for every operational meteorologist that is forecasting the weather I also have them paired with a statistics scientist who is creating these models that we use to mitigate hazard Q What are those models A The main models we use for PSPS citizens safety power shutoffs are the Fire Foreseen Index that predicts the probability of fast intense spreading fires and the Ignition Probability Weather Model that predicts the probability of ignitions as well as fire simulations of over million virtual fires per day On top of these models we layer on the machine learning wind gusts as well as forecasts from external agencies like the National Weather Amenity Q Tell me how the fire anticipated index model works A The fire foreseen index provides material every hour at these hexagons that are kilometers big So we re modeling the weather at about of these little areas of our arrangement territory every hour going out five days It s a machine learning classification model developed internally by our figures science club and we ve taken weather evidence fuel facts topography input and historical fire occurrence and have trained up a machine learning model to learn what conditions lead to catastrophic fires We can extract a value of basically what is the probability that we have critical or catastrophic fire foreseen and then we can use those values to determine what the relative danger is Q How does this model work going backwards in time A We re able to basically take the model and run it backward over the past years so that we can extract what it was saying on October If I had a time machine and I had these models and I had these tools and I went back in time would we have been de-energizing North Bay for example or these circuits that caused these catastrophic fires Basically with this incredible historical material that we have we re able to cast the model over the past years and then calibrate it such that we re not only mitigating a lot of the catastrophic fires of the past but we re also balancing the impact of PSPS events in order to essentially establish the models and establish the guidance that we would then use Q What happens when a dry windstorm is upon us A We have over weather stations and cameras and all that evidence is represented on a map where I can see all of our infrastructure and we re using that in real time to determine whether the winds are high enough to justify turning the power off proactively Q Lightning can be a big cause of a fire but it s very hard to predict where it will strike How do you factor that in A As we start to see clouds bubbling up thunderstorms growing we can then look at radar and then we can look at exactly where the lightning strikes are happening in relation to our assets Q How do you know how effective you ve been in preventing wildfires so far A When you compare October of when power was shut off to nearly a million customers to the event that started this all off the North Bay fires in October the event was stronger than In you had a dozen catastrophic wildfires that broke out In we had zero although we revealed after the fact we had -plus cases of damage including trees through our lines and branches down It s impossible to prove but we definitely prevented something Q Has the mechanism failed you A One of my adages is all models are wrong various are useful As a scientist I m a trained pessimist and skeptic But what I will say is that these are the the greater part accurate models to date absolutely Are they right No We can t forecast the weather perfectly That remains the big gap Scott Strenfel Title PG E Senior Director Meteorology Operations and Fire Science Age Marital status Married school-age children who are proceeding in sports Teaching Leland High School graduate San Jose State University bachelor s degree in meteorology and master s degree in meteorology with an emphasis in fire science Five Compelling Things About Scott Strenfel With his wife Kari Strenfel has summited mounts Kilimanjaro Whitney Shasta and a meager ers in Colorado Grew up in San Jose with the Mercury News on his family breakfast table every morning The second San Jose State apprentice enrolled in the Fire Weather Research Lab activity where he met his wife who was the first Recognized this year as the university s College of Science Outstanding Latest Graduate Enjoys mountain biking snowboarding and skiing with his family
