Historically unprecedented warming is projected during this century. Observed temperatures are generally within the envelope of model simulations of the historical period (gray shading). Shading indicates the range of annual temperatures from the set of models. Temperatures in California (orange line) have risen almost 3☏ since the beginning of the 20th century. Projected changes for 2006–2100 are from global climate models for two possible futures: one in which greenhouse gas emissions continue to increase (higher emissions) and another in which greenhouse gas emissions increase at a slower rate (lower emissions). For example, strong El Niño events often cause excessive precipitation in Southern California, but the effects in Northern California are inconsistent.įigure 1: Observed and projected changes (compared to the 1901–1960 average) in near-surface air temperature for California. Because of its large north–south extent and the existence of several mountain ranges, extreme climate events often affect only a portion of the state. Annual average (1991–2020 normals) temperatures vary from less than 40☏ at the highest mountain elevations to less than 50☏ in the northeast and greater than 70☏ in the southeast. Due to the moderating effect of the Pacific Ocean, coastal locations experience mild year-round temperatures, while inland locations experience a wider range of temperatures. In winter, this system moves southward, allowing storms to bring precipitation to the state. During summer, the North Pacific High and the jet stream move northward, keeping storms north of the state and resulting in dry summers. The North Pacific High, a semipermanent high-pressure system off the Pacific Coast, and the mid-latitude jet stream play dominant roles in California’s seasonal precipitation patterns. The deserts in the south are some of the Nation’s hottest and driest areas, while higher elevations can experience low temperatures and heavy snowfall. Original article on Live Science.California, the most populous and third-largest U.S. "Given the odds, it makes sense to prepare for another dry year," the researchers wrote on the center's California Water Blog.Įmail Becky Oskin or follow her. Water years are divided into five types, ranging from critically dry to wet. In the Sacramento Valley - the state’s largest source of water supply - there’s a 29 percent chance that the 2014-2015 rainfall year will also be critically dry, and a 64 percent chance that it will be a combination of dry or critically dry, according to researchers at the University of California, Davis, Center for Watershed Sciences. But most of California's winter rainfall occurs in Northern California's Sacramento and San Joaquin river basins, and an El Niño may not bring enough winter rain for the thirsty state to recover from the ongoing drought, water experts say. This Pacific Ocean climate phenomenon shifts global weather patterns, and often means heavier-than-normal winter rainfall in Southern California. While an El Niño offers hope of a wet year in Southern California, a moderate or weak event could mean another dry winter in 2014.įorecasters say there is an 80 percent chance of an El Niño developing by fall, but it's no slam-dunk. Fresno: 4.81 in (12.22 cm) 42 percent of average.San Diego: 5.06 in (12.85 cm) 49 percent of average.San Francisco: 12.54 in (31.85 cm) 53 percent of average.Sacramento: 10.35 in (26.29 cm) 51 percent of average.Los Angeles: 6.08 inches (15.44 cm) 41 percent of average.Here are some of the precipitation totals, as of June 29, from the National Weather Service. The same region received 3.15 inches (8 cm) from July 1, 2012, through June 29, 2013, which is 49 percent of normal for the water year. The city of Bakersfield, in California's farm-rich Central Valley, received 2.41 inches (6.12 centimeters) of rain, or 37 percent of normal precipitation through June 29, according to the National Weather Service. Many communities have ordered water-use restrictions, and farmers are feeling the effects of low water allocations from the state. The entire state is in severe drought conditions, with 77 percent in an extreme drought and 33 percent considered to be in an exceptional drought, according to the National Drought Mitigation Center. Jerry Brown declared a drought emergency for the state on Jan. This year is the third consecutive below-normal water year for California.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |