Understanding California wildfires for an outsider (Sacramento, Paradise: 2013, apartments, power lines)

[ColdAilment]

Pardon any ignorance on my part regarding this topic, but the most common natural disasters in California seem to be wildfires, and they seem to be more common in California than just about anywhere else in the country. With the exception of one wildfire in Tennessee last year I believe it was, wildfires in the east, south east, and midwest seem very very rare, especially when compared with an almost regular occurrence of wildfires in California.


So to an outsider, who has never even visited California, can you explain to me and others who may be wondering, why are wildfires so common in California? And why are they so unimaginably destructive?


My theories, based on very limited research, were a combination of the following:


- Over population in drier areas. Too many people in places that are susceptible to fires due to a drier climate means increased chance of someone throwing a cigarette butt out the window, or power lines to the millions of people defaulting and sparking, or motorists driving up and down highways may inadvertently send sparks off through chains or other portions of a vehicle scrapping the roadway.


- Dry climate susceptible to fire either from campers or lightning. I know southern California is rather dry, but my understanding was that northern California was more temperate and saw more rain. A quick Google search states that Paradise California receives over 50 inches of rain per year? This seems pretty high, higher than I would have anticipated. It's higher than even a wet season here in the Midwest, we average 38-39 inches of rain per year here, and we're close to 50 this year, way above normal. Is Paradise normally that wet? Sacramento averages about 18-20 inches of rain, mostly in the Winter months, according to the same search.


Any enlightenment on these disasters and their factors would be greatly appreciated! Thank you.

[CCbaxter]

CA is experiencing a drought. All the towns and cities were there first.

https://droughtmonitor.unl.edu/Curre...htMonitor.aspx

[volosong]

In the north, lightening strikes are a significant cause of wildfires, but overwhelmingly, most devasting wildfires are caused by a seasonal shift in the climate. In the autumn and throughout the winter, the semi-persistent Pacific High high pressure system shifts from off the coast of northern/central California and parks itself over the Colorado Plateau, (somewhat near the Four Corners area).

Air descends over a high pressure system and heats up adiabaticly. Being over a large continental land mass, it is dry air, (low humidity). Air flows clockwise out of a high pressure system, which means the dry desert air of the Colorado Plateau flows toward California. The Colorado Plalteau is at, and over, 5,000 feet of elevation and an air parcel continues to heat up as it descends to the coast.

Additionally, as the air flows through the canyons of the Sierra Nevada range, as water flowing through a narrow canyon, it increases velocity.

The results are very dry, very low humidity air that flows from the desert, it increases in velocity as it goes through the canyons, the low humidity sucks what little moisture there is in the coastal chaparral, and the least little ignition starts a wildfire that is next to impossible to extinguish until the weather condition changes, (the high moves east, replaced by a low and its associated humidity/precipitation).

You are correct in that the population growth of the region increases opportunities for ignition sources.

[1AngryTaxPayer]

Wildfires are naturally occurring and many say that every time we put one out it increases the fuel for the next one. It just gets worse when we have years of drought which is also naturally occurring. Plus, every wet year we get just increase the growth. Lather, rinse, repeat.

[ColdAilment]

Originally Posted by 1AngryTaxPayer

Wildfires are naturally occurring and many say that every time we put one out it increases the fuel for the next one. It just gets worse when we have years of drought which is also naturally occurring. Plus, every wet year we get just increase the growth. Lather, rinse, repeat.

I understand some wildfires are naturally occurring, but some are not. Some are blamed on power lines or brush fires, or fireworks. Surely those should be avoided.

[Tulemutt]

Originally Posted by ColdAilment

I understand some wildfires are naturally occurring, but some are not. Some are blamed on power lines or brush fires, or fireworks. Surely those should be avoided.

Obviously.

With regard to your comment about the amount of precipitation in northern CA ... the north coast is wet and stays wet most of the year. Inland, Paradise area, gets its rain mostly from November through about April. Like most other areas of the state, it then gets just about - nothing - in the way of precipitation until the next November. East and mid-west spread their precipitation year round.

[ryanst530]

Having worked for the Forest Service for a short stint during college, the general consensus among BLM and USFS fire fighters was that unmanaged or poorly controlled underbrush ("duff") and dead trees are major contributors to large fires... the ones that burn large acreages.

Extended dry weather patterns and droughts increase the likelihood of fires starting.

So the situation is really two-fold. Fires are starting more frequently because of the dry weather and droughts, and they are difficult to contain quickly because of the fact that fuel for those fires litters the forest floors, essentially connecting tree to tree, bush to bush, with lots of dead trees interspersed acting as fire amplifiers.

[wac_432]

Here in the south, our wildfires--though dramatic--are not as bad as they were before the area became populated. In prehistoric times, the fires would only be sparked by lightning, which was usually accompanied by rain, which would then douse the fire. The hills AND valleys were FULL of tinder-dry scrub during the dry season. Every few hundred years, the "perfect storm" of a dry inside-slider type system would spark a fire with dry lightning, and then drive it with the Santa Anna winds that sometimes follow these types of cold fronts. These fires would be truly cataclysmic, burning through 500 years worth of fuel with no humans to intervene (or structures to burn).

Nowadays we have cigarettes, campfires, dragging trailer chains, downed electrical wires, etc. sparking off fires during nearly every other Santa Anna event, even with no lightning. That means that the same fire-prone areas now burn once every 5-10 years. The 2018 Hill Fire (lesser known fire that sparked at the same time as the 2018 Woolsely fire that sent the celebs scrambling) started just upwind of the burn scar of the 2013 Springs fire. It blew right into the footprint of the old burn and came to a halt. With only 5 years worth of fuel regrowth in the Springs fire footprint, the Hill fire fizzled.

Even though the footage is dramatic, in the Thomas Fire and Woolsely fire, hundreds of thousands were ordered to evacuate for a day or two, but only a few hundred structures burned. The majority of these were multi-million dollar mansions in the hills. I'm not trying to sound callous or minimize people's losses, but the vast majority of these properties are fully insured and their owners are quite wealthy. Some "irreplacable" knicknacks are lost, especially to those who keep a lot of physical items (sentimental or custom clothing, offline pictures, 1st-edition books, signed sports memorabilia, curios and antiquities picked up during world travels, weddings, etc.) but many of these are the trappings of wealth, not the essentials needed to survive. It is sad, but not really tragic.

There are, of course, some edge-of-town apartments and trailers which were destroyed. These are the real tragedies, because few renters have insurance, and mobile home owners own the structure, but not the property underneath (which is often the only thing left after a fire).

However, the reality is--except in the case of Paradise--which was a town simply built in the wrong place without adequate land management--the fires burn up in the hills and stop once they burn down to the edge of the populated valley floors. If you don't want your stuff to burn, live in the flat (often poorer) urban areas, or on the coast, where 99.5% of the population live, untroubled by fire, except for the occasional smokey day or freeway closure.

The other fire reality, that people are going to have to face, is that towns like Paradise (and new subdivisions built in the hills and valleys of fire country) will have to pay for (and suffer the effects of) creating and maintaining a LARGE defensible space around the town. The current practice of depending on homeowners to clear 400' back from their own structures is not working. People aren't following the rule, and even if some are, patchwork defensible spaces just don't work. If we don't want entire hill towns to burn, cities will need to take charge and start back-burning 1000 yards or a quarter-mile from the edges of mountain towns in fire country. It will mean a few days of smoke a year, a perpetual ugly burn scar, and some associated erosion-management construction expenses, but it will have to be done, or we can continue to just let these towns burn down.

[JGC97]

OP ...... California has been living with drought conditions for over five years. Everything is drier. That annual rainfall you quoted about Paradise is in a "normal" year. Nothing has been normal about our weather for a very long time. And, with the exception of a couple smaller fires caused by human negligence, the past few major fires are the fault of PG&E and their lack of maintaining their transformers and wiring. I hope this last one in Butte County puts the sobs out of business.

[NewbieHere]

Originally Posted by HereOnMars

OP ...... California has been living with drought conditions for over five years. Everything is drier. That annual rainfall you quoted about Paradise is in a "normal" year. Nothing has been normal about our weather for a very long time. And, with the exception of a couple smaller fires caused by human negligence, the past few major fires are the fault of PG&E and their lack of maintaining their transformers and wiring. I hope this last one in Butte County puts the sobs out of business.

59 inches last year.