Could a hurricane hit California?
Rhett Butler, mongabay.com
August 20, 2007
Hurricane Katrina was particularly devastating to New Orleans because the city lies below sea level and is surrounded by three large bodies of water -- Mississippi River to the south, Lake Pontchartrain to the north, and the Gulf of Mexico to the east. In New Orleans, most destruction was associated with flooding. Flooding would likely be less of a concern in San Diego which sits at a higher elevation and would more easily be evacuated than the Louisiana city. However, San Diego and other Southern California communities could expect more wind damage and destruction caused by mudslides. In 2005, mudslides and rockfalls resulting from heavy rains killed ten people and destroyed 15 homes in La Conchita, California.
Hurricane Risk in California
This image combines data from various NASA satellites and shows sea surface temperatures (80F or higher) warm (orange areas) enough to power tropical cyclones. The darker the orange color, the warmer the water. Courtesy of NASA
"On October 2, 1858, estimated sustained hurricane force winds produced by a tropical cyclone located a short distance offshore were felt in San Diego," said Christopher Landsea, the co-author of a paper on the 1858 hurricane and a hurricane researcher at NOAA's Hurricane Research Division at the Atlantic Oceanographic and Meteorological Laboratory in Miami, Fla. "Extensive damage was done in the city and was described as the severest gale ever felt to that date, nor has it been matched or exceeded in severity since."
Coral evidence suggests the ocean was particularly warm that year and, according to a press release from NOAA, "warmer waters and a conducive atmosphere allowed the hurricane to sustain Saffir-Simpson Hurricane Scale Category 1 intensity (wind speed of 72-95 mph) as far north as southern California. Available evidence suggests that the hurricane tracked just offshore from San Diego, without the eye coming inland, but close enough to produce damaging winds along the entire coast from San Diego to Long Beach."
Should such a storm return it would cost the region hundreds of millions to billions of dollars in damage according to Christopher Landsea and Michael Chenoweth, authors of the study.
"What this also tells us is that a hurricane has directly affected southern California in recorded history and we should remember that if the conditions are right, the area could get hit again," Landsea said. "Mike and I hope that emergency managers, residents of the area, business owners, the insurance industry, and decision-makers be made aware of this possibility, as most in southern California may think they are completely safe from hurricanes because they are on the Pacific coast instead of the Atlantic."
Impact of Climate Change on Hurricanes
While there is considerable date over whether observed climate change is behind the recent increase in hurricane activity in the Atlantic basin, several studies suggest that warmer oceans could produce stronger storms in the future. Kerry Emanuel, the author of a study published in Nature, warns that since hurricanes depend on warm water to form and build, global climate change might increase the effective range of hurricanes in coming years. It is conceivable that a warmer Pacific could someday enable a hurricane to strike cities farther north, even Los Angeles.
Hurricanes already nearby in Mexico
Hurricanes do batter Baja California (the northernmost state of Mexico, located just south of San Diego) from time to time, usually coinciding with El Niño years. In September 1997, an El Niño year, Hurricane Linda became the strongest storm recorded in the eastern Pacific with winds estimated at 180 mph For a time there was concern that Linda would come ashore in California as a tropical storm, but the storm turned away and the state only experienced high surf and thunderstorms. More recently, in 2006, the Pacific coast of Mexico was battered by Hurricane John and Hurricane Kristy.
Global warming is causing stronger Atlantic hurricanes finds new study -- 3/01/2007
Global warming is fueling stronger hurricanes according to a new Geophysical Research Letters study that revises that database of historic hurricanes. Previously the hurricane database was considered inconsistent for measuring the record of tropical storms since there have been significant improvements in the technology to measure storms since recording-keeping began. Before the development of weather satellites, scientists relied on ship reports and sailor logs to record storms. The advent of weather satellites in the 1960s improved monitoring, but records from newer technology have never been squared with older data. The new study "normalizes" the hurricane record since 1983.
Hurricane intensity linked to global warming -- 8/15/2006
A new study says climate change is affecting the intensity of Atlantic hurricanes and that hurricane damage will likely worsen in coming years due to increasing ocean temperatures. Unlike recent studies that have linked higher sea temperatures to an increase in the number of hurricanes, the new research shows a direct relationship between climate change and hurricane intensity.
Global Warming Fueled Record 2005 Hurricane Season Conclude Scientists -- 6/22/2006
Global warming accounted for around half of the extra hurricane-fueling warmth in the waters of the tropical North Atlantic in 2005, while natural cycles were only a minor factor, according to a new analysis by Kevin Trenberth and Dennis Shea of the National Center for Atmospheric Research (NCAR). The study will appear in the June 27 issue of Geophysical Research Letters, published by the American Geophysical Union
Study questions link between hurricanes and global warming -- 5/10/2006
New research calls into question the linkage between major Atlantic hurricanes and global warming. That is one of the conclusions from a University of Virginia study to appear in the May 10, 2006 issue of the journal Geophysical Research Letters. In recent years, a large number of severe Atlantic hurricanes have fueled a debate as to whether global warming is responsible. Because high sea-surface temperatures fuel tropical cyclones, this linkage seems logical. In fact, within the past year, several hurricane researchers have correlated basin-wide warming trends with increasing hurricane severity and have implicated a greenhouse-warming cause.
Number of Category 4 and 5 hurricanes has nearly doubled over past 35 years -- 9/16/2005
The number of Category 4 and 5 hurricanes worldwide has nearly doubled over the past 35 years, even though the total number of hurricanes has dropped since the 1990s, according to a study by researchers at the Georgia Institute of Technology and the National Center for Atmospheric Research (NCAR). The shift occurred as global sea surface temperatures have increased over the same period. The research appears in the September 16 issue of Science.
Hurricanes getting stronger due to global warming says study -- 8/29/2005
Late last month an atmospheric scientist at Massachusetts Institute of Technology released a study in Nature that found hurricanes have grown significantly more powerful and destructive over the past three decades. Kerry Emanuel, the author of the study, warns that since hurricanes depend on warm water to form and build, global climate change might increase the effect of hurricanes still further in coming years.
This article is an updated version of a mongabay.com article that appeared September 8, 2005. This article uses quotes an information presented in a National Oceanic and Atmospheric Administration press release issued Jan. 11, 2005.