The Thomas Fire of Ventura and Santa Barbara Counties in Southern California has now become (as of Sunday Night) the 5th largest fire in California State history. And based on trends and fire weather expected, it may go for the state record (273,246 acres). After winds decreased somewhat Friday afternoon-Saturday, they picked up again on Sunday, causing extreme fire growth to an incredible 50,000 acres and reducing the containment from 15% to 10%.
Since the fire developed last early-morning Tuesday, it has exhibited extreme fire behavior in intense Santa Ana winds with gusts of 45-80 mph, fanning flames and, more importantly, embers far downwind of the actual fire. Currently, 790 structures have been destroyed with the evacuation of over 88,000 people. A 70 year old woman died after being overtaken by the fire following suffering severe injuries in a car crash. In San Diego County, another woman was badly burned over 50% of her body in the Lilac Fire while helping horses escape from a thoroughbred training facility. And speaking of horses…46 horses were confirmed killed at San Luis Rey Downs where the trainer was badly injured. The death toll will likely rise among the horses as 450 horses were there when the fire rapidly struck. Many burned to death refusing to leave their stables or running back into them, while others died from shock even after initially safely away from the fire’s path. Meanwhile, another 29 horses suffered a similar fate at a ranch in Los Angeles County’s Creek Fire.
Unfortunately, high fire danger will continue through Monday with gusts over 45 mph allowing the Thomas Fire and any other fires which develop to easily spread and do so rapidly. Conditions should relax Monday night before possible re-intensification on Tuesday. As mentioned, the Thomas Fire may reach record territory tomorrow based on trends. And as of now, NO significant measurable rainfall is expected in California (or much of the Southwest US and Great Plains) the next 10 days. A blocking upper-atmospheric high pressure pattern over the Eastern Pacific will certainly allow for intensification of drought conditions and continued dryness and moderate to high fire danger for days to come. I should also note, fire danger will also be elevated on parts of the High Plains. Much of Eastern Colorado into Western Kansas are under red flag warnings for Monday because of expected elevated breezy conditions and low humidity with dry fuels.
A few months ago, it was Wine Country, this week it is Southern California. Powerful Santa Ana winds…with gusts up to 80 mph… are creating conditions favorable for explosive fire development and extreme fire behavior. Multiple fires have already broken out across Southern California leading to the destruction of (likely) hundreds of structures in what is usually the early part of the dry season in the region.
The largest fire…the Thomas Fire…has now burned an incredible 96,000 acres since early Tuesday morning! An area equivalent to 150 square mi/241 square km. Over 116,000 acres total have been burned in total across Los Angeles and Ventura Counties, with over 200,000 people ordered to evacuate.
Very powerful Santa Ana winds…easterly winds blowing down the Santa Ana Mountains of Southern California are driving these highly destructive fires. A strong ridge of high pressure sitting over western North America…locked in place by a highly amplified atmospheric wave pattern…is causing enhanced surface pressures over the Interior West. This elevated, dense, high pressure air is sinking rapidly down the mountainous terrain towards lower pressure out at sea causing the powerful downsloping and gap winds…the Santa Anas…which through Friday morning may produce gusts near 80 mph fanning fires. And because the air flow undergoes “adiabatic heating” as it sinks to lower elevations and compresses under higher atmospheric pressure near sea level, the temperature of the air both warms and dries *significantly* drying fuels as the high wind speeds fan the flames over those fuels.
The blocking upper-air pattern favoring these unusually warm, dry conditions out west (with unusually cool conditions in the Eastern US) will continue into next week unfortunately. While fire weather conditions will vary (mild improvement as far as winds and humidity this weekend), no significant rainfall is expected during the period for Southern California…in what should be their wet season.
Current research suggests that California’s increasing shift toward more drought conditions (which can fuel and extend wildfire seasons) is being caused by the reduction in sea ice in the Arctic (a symptom of human-induced climate change). As a side note, the Arctic is experiencing extremely abnormal temperatures this November and early December, with temperatures up to 30-50 degrees F above normal in some locations and top 2 or 3 record low sea ice extent for this time of year over the Arctic Ocean (record low in the Chukchi Sea and Bering Sea).
Fires have been raging across the world this year with unprecedented scope. Major wildfire outbreaks have been notable from tropical rainforests in Africa and South America to the taiga of Canada and Russia. Even Greenland has seen an unusual amount of fire activity on the edge of the ice sheet. This year, Western North America, and the Iberian Peninsula of Europe have been particularly hard hit with life-threatening fires (see HERE,HERE, and HERE). Although fires occur every year with variable impacts, a significant upward trend can be tied to climate change allowing both natural and human activity to ignite and expand the destructive intensity of wildfires.
As of now (5:30 pm PDT), the death toll in the California Wildfires is up to 35 and is expected to go up further. 18 in Sonoma County, 9 in Mendocino County, 4 in Yuba County and 4 in Napa County. 5700 structures have been destroyed and 221,000 acres have been burned. Treating the conglomeration of fires as a single event (as all the Northern CA ones initiated Sunday Night), this is by far the most destructive fire event in state history and one of the deadliest. Simply horrifying and very sad.
Firefighters have begun to have some containment success the past 48 hrs with slower winds and at least some periods of slightly improved humidity. However, tonight-Sunday morning will feature an intensification of extreme fire danger. This is because a strong surface high pressure system will advance toward the central Intermountain West this weekend, intensifying downsloping Diablo winds from the hilly and foothill mountainous terrain of Northern California. North-northeast winds may gust as high as 45-60 mph Saturday, inducing very low humidity values, drying out fuels and potentially promoting extreme fire behavior (high forward speed, rapid growth) in existing fires as well as any new fires. Red Flag Warnings have been issued by the National Weather Service to cover this forecast potential.
There are no thunderstorms forecast, so any new fires would be likely started by human activity. So folks in these areas need to very much be careful with anything which can potentially start fire and really…just avoid starting any outdoor fire or using anything which sparks.
Some good news…mid-range computer model forecasts suggest a pattern shift toward precipitation and cooler weather by the end of next week. Just have to get through the next week of fire activity before some meaningful hydrologic relief to aid the firefighting efforts.
The fire conditions Wed Night into this morning were not as severe as expected thanks to weaker winds. This allowed firefighters to make some ground against fires through the night, however high fire danger remains and will continue for days into the future, with no rain in sight.
Air quality remains terrible in the Bay Area. Folks in that region should do what they can to avoid being outside if at all possible.
I’ll add any additional updates related to fires on this post today. Stay safe in these areas!
The new geostationary weather satellite, GOES-16 captured this high spatio-temporal resolution loop of the smoke plume over the Bay Area of Northern California this evening before sunset. The deep smoke is embedded in the low-level north winds, while the white, high cirrus clouds are in southwesterly flow. You can right click to save or open in the new tab to see the larger version of it. It’s amazing but frightening to know what’s happening under all that smoke.
The Wine Country Fires in Northern California have now destroyed over 3500 structures, making it the most destructive fire event in state history. And with 23 deaths now reported, it is quickly approaching the record for the deadliest. There are still areas burned where police have yet to search for potential victims because the primary operations are focused on evacuations and maintaining safety in the current fluid situation. Unfortunately, given that the missing persons are over 280, even with many being found safe, the death toll is still likely to go up as some are found.
Amazing the disturbing level of destruction of this fire event. I was only 7 yrs old in 1991, but I remember the Oakland Hills Firestorm, as it was plastered all over the news as much as this event. I didn’t think I could imagine such a disastrous fire worse than that.
Update at 5:30 pm PDT Wed: Update on the Meteorological Conditions in the Bay Area/Napa Valley Region.
Numerous fires continue to largely out of control over the Napa Valley/North Bay region. Heavy Smoke (with particulate matter >2.5 micrometers) is spreading southward over the Greater Bay Area reducing visibility and causing air quality to be considered very unhealthy for all individuals in the region with VERY UNHEALTHY conditions in the hilly terrain east of Santa Rosa and Oakland. If you can stay indoors, do so, especially for the young, elderly, and those with chronic breathing problems.
A RED FLAG WARNING REMAINS IN EFFECT FOR MUCH OF N. AND C. CALIFORNIA FROM NOW UNTIL TOMORROW AFTERNOON. As high pressure builds across Oregon into NE. Nevada, easterly downsloping winds will intensify the foothills across the interior of Northern CA, increasing the threat for any fires which develop to spread quickly and existing fires to expand acreage quickly. These winds will help maintain very conditions longer into the night, slowing humidity recovery and allowing fires to potentially exhibit extreme behavior (heat, forward speed, self-maintenance). Winds may gust up to 45-50 mph in some areas.
These fires have largely been a result of 1) the 5 yr extreme drought weakening trees 2) the very wet winter producing abundant brush growth 3) extreme hot, dry summer drying out all fuels.
New evacuation orders have already come out for some areas, including the City of Calistoga (northeast of Santa Rosa) where the entire town of over 5,000 are being told to leave. See the Impact Statement at the bottom of this post…but folks need to be ready to evacuate if necessary at a moment’s notice.
–Meteorologist Nick Humphrey
CalFire has updated news at 11:30 am PDT and now say 21 people have been confirmed killed and 172,000 acres have now burned across the entire state. The most destructive fires are in North-Central California north of the Bay Area, but the Canyon 2 Fire continues to menace Anaheim in Southern California.
A RED FLAG WARNING is in effect for much of the interior valleys and foothill terrain of California.
This is for extreme fire danger today – Thursday. As high pressure builds this evening and tonight over Nevada and east of the Sierra Nevada Mountains, a NE-SW pressure gradient will intensify, leading to strong downslope winds known as Diablo winds or Santa Ana Winds (the former in Northern CA, the latter in Southern CA). These winds will gust potentially 40-45 mph+. In addition, because they are downsloping, the air undergoes adiabatic warming…warming caused by the air compressing as it flows down toward higher vertical pressure at lower elevations. The air not only warms, but also dries out, turning winds blasting out of canyons into a hot blow dryer…drying out fuels and allowing a fire to turn into a firestorm.
I CANNOT STRESS ENOUGH…if you live in areas under the red flag warning or if you know anyone who lives in these areas, especially near the urban-wildland interface…please have a plan of what to do if a mandatory evacuation is ordered for your area and have a way to get warnings. ESPECIALLY AT NIGHT. Stay in contact with friends/relatives, have someone stay up to watch tv or listen to radio, keep your phone on and charged, have a weather radio. Most importantly, make sure those smoke detectors are working as they may be a final warning of danger impacting your home at night. These fires may intensify or new ones may start Wed night-Thurs morning because of strengthening winds and the humidity…which normally increases at night…may not do so because of the very dry nature of the winds. This will allow for potentially explosive fire behavior. And please, be smart with anything related to flammable materials and clear any brush away from your home if possible, to give you more time if a fire does approach.
I really hope the situation does not worsen significantly. Fires are scary events and incredibly destructive. Please be safe and be ready if you are in these areas.
I’ll have updates on this page throughout today and tonight.