Friday, August 31, 2007

August weather turns erratic


From lightning and thundershowers to intense heat waves, Southern California’s normally stable August weather turned erratic this week, prompting officials to issue a Stage 1 emergency to conserve energy and excessive heat watches.
While inland parts of Santa Barbara County soared into the high 90s yesterday, temperatures on the coast remained more mild, but still far above average.
“Although it’s hot at the coast, we’ve been spared the brunt of the heat wave,” said Alan Rose, meteorologist for KEYT Channel 3.

Rose said a high pressure system centered over Arizona has pushed hot, dry air west, which has forced temperatures to rise.
Accompanying the higher than normal temperatures was thunderstorms, which put on a rare lightning show for many on the South Coast, but sparked at least three brush fires.
Rose said the unstable air that made room for the thunderstorms was created as a result of storm energy that rotated around the base of the high pressure system.
The high temperature in Santa Barbara reached 84 degrees yesterday, six degrees higher than the norm for this time of year.
At some points yesterday, the temperature difference between Santa Ynez and Santa Barbara was as much as 20 degrees.
Rose said the variation in temperatures were aided by the high pressure system, but that a spell of weak onshore winds have failed to penetrate the scorching inland areas, which is contributing to the difference.
Aside from the usual heat precautions, like staying in air conditioned areas and remaining hydrated, the California ISO (Independent System Operation) issued a State 1 emergency yesterday when the state’s energy reserve levels fell below 7 percent.
Jane Brown, public affairs regional manager for Southern California Edison, said when temperatures soar, the power supply is like a bathtub with several faucets pouring into it. The only problem, according to Brown, is more water was draining from the tub Wednesday than was entering.
“When you have more water going out of the bathtub and going into the bathtub you’re in trouble,” Brown said.
According to the ISO web site, a Stage 2 emergency is called when the minimum operating reserve level falls below five percent, which can prompt the ISO to call on “interruptible” programs to conserve energy. Participants in the “interruptible” programs are typically commercial and industrial customers who receive a lower electricity rate in exchange for reducing their energy use by a specific amount during Stage 2 emergencies.
A Stage 3 emergency is called when reserves fall below the minimum requirement, which is about 3 percent. At this stage, the ISO can require utility providers to begin implementing rotating outages.
Aside from the headaches the heat has caused, Brown said the lightning damaged several transformers around Santa Barbara Wednesday night, leaving about 100 customers powerless. As of 2 p.m. yesterday, Brown said most of the power had been restored, but five customers served by a the most badly damaged transformer were not expected have power restored until 9 last night.
Stuart Seto, a weather specialist for the National Weather Service in Oxnard, said excessive heat watches, which were in effect yesterday for Los Angeles County, have been issued for parts of Ventura County today.
Seto said temperatures are expected to climb as high as 112 degrees in parts of Ventura County.
Rose said the thunderstorms aren’t expected to return over the weekend, but the high pressure that’s driving temperatures up will.
“This is just a very strong ridge of high pressure,” Rose said. “When it’s this strong you get a significant increase in temperatures.”

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