Southern California Fall Heat Wave Worries Fire Authorities

The National Weather Service for Los Angeles/Oxnard reports unseasonably warm Southern California fall temperatures that are between 10 degrees and 20 degrees above normal. As a result of the high pressure system that ushers in the dry heat, forecast Santa Ana winds increase the risk of fire danger in areas with dry brush. A Department of Forestry and Fire Protection spokesperson alerted the L.A. Times that 2,000 seasonal firefighters are kept on as a precaution. Just how common are California heat waves -- and will the trend continue?

* An Increase of three Heat Waves per Century

Writing for the Association of Pacific Coast Geographers on 2008, researchers have discovered that Los Angeles in particular is experiencing a marked uptick in heat waves. Findings support the notion that the number of events has increased by three for each century. The tripling of this figure is associated with a steady warming trend of the L.A. basin.

* Strain on the Water Supply

Attributing the heat waves to steady warming of the L.A. area, which in turn is caused by the increase of human activity in the city, researchers predict that there will be more notable heat waves. Moreover, of the average length of heat waves will increase. A direct result of this development is "increase in wildfires, and more strain on water, power, and agriculture." Already the County of Los Angeles warns that Southern California summer temperatures above 100 degrees Fahrenheit in valleys -- and above 110 degrees Fahrenheit in the low desert -- "are not uncommon."

* Notable Spring Heat Wave hit Southern California in 2006

NASA's Earth Observatory noted in 2006 that nearby Long Beach noted record temperatures that were 10 degrees Fahrenheit above normal spring weather. Relying on heat imaging, satellite photos revealed that the land mass had reached temperatures "nearing 150 degrees Fahrenheit" at 2:20 p.m. local (Pacific) time.

* More extreme nighttime Heat Waves

Climate researchers at the American Meteorological Society differentiate between daytime and nighttime heat waves. They document "stronger nighttime heating" especially along California's southern coast. In contrast, daytime heat weaves appear to be more common in the northern coastal hills.

* Looking into the Future

The Southern California Association of Governments warns that by the year 2100, Southern California's overall temperature will rise by four to 10 degrees Fahrenheit. Heat waves "will likely intensify and last longer." In the same time frame, water levels along the coast will rise by 1.5 feet, even as precipitation continues to be erratic and unpredictable. This will most likely lead to water shortages. Further aggravating the expected temperature variations are short-term climate events, such as El Niño weather patterns. 

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