San Diego’s Rain Year Ends As One Of Driest On Record
Monday, June 30, 2014
San Diego closes the books Monday on its rainy season, or lack of one. The region is set to record its third year in a row of below normal precipitation.
San Diego Weather Extremes
Rainfall 5.5 inches below normal
Three-year rainfall deficit is more than 12 inches
Nov. 2013 through May 2014 is warmest on record (for that time period). Daily combined high/low was 3.6 degrees above average
Santa Ana Wind clocked at 101 mph near Cuyamaca in May 2014 is strongest recorded
San Diego on Monday is wrapping up one of its driest years on record, with just 5.06 inches of rain recorded at Lindbergh Field, according to the National Weather Service.
The average annual precipitation for downtown San Diego is 10.34 inches, measured from July 1 through June 30; that leaves the region’s rainfall total at 49 percent of normal, and the 13th driest year ever recorded.
Escondido recorded its driest all-time record of 5.75 inches of rain; the normal average is 15 inches.
It’s the third consecutive year of below-normal rainfall.
The last significant rain accumulation in San Diego County occurred in December 2010 when a rare atmospheric river system brought wave after wave of storms, dumping 5 inches in downtown, said Alex Tardy, warning coordination meteorologist with the National Weather Service San Diego.
Since then, precipitation has been dismal, he said.
"If you add up all those years we should have 30 inches of rain total," Tardy said. "And we’re not even close to that. We’re short a little over a foot — that’s a whole season basically."
Also going down in the record books is San Diego County's above-average warm temperatures.
"This past winter from November through May is the warmest on record," Tardy said. "That’s huge because our records are almost 150 years."
The daily combined high and low temperature at Lindbergh Field from November 2013 through June 2014 was 3.6 degrees above average.
Another weather extreme this year was the pair of Santa Ana wind events that battered San Diego County in April and May and fueled more than a dozen raging wildfires.
"Each one of those events in San Diego County alone saw winds over 80 miles per hour in our foothills," Tardy said. "The strongest wind was 101 miles per hour... up near Cuyamaca Lake."
"At the same time, humidity was almost not measurable, down in some places 2-3 percent," Tardy added.
The nearly week-long Santa Ana wind event that began on May 12 also brought record heat. On May 15, the temperature reached 97 degrees in downtown San Diego and 104 in Escondido and El Cajon.
The ongoing drought conditions have parched canyons and hillsides and raised the risk of fire danger.
“The fuels, the vegetation, is as dry as it can get,” Tardy said. “Driest we’ve seen on record is the way the fuels are right now, and we’re just getting through the month of June.”
Tardy said there is a glimmer of hope with the brewing El Niño. If it strengthens, it could bring more rain-producing storms to San Diego.
The weather phenomenon changes the heating pattern of the atmosphere and pulls the Pacific jet stream farther south. It has the potential to play havoc on weather systems across the globe, causing heavy rain and mudslides in some areas, drought in others, and disrupting the marine food chain.
“Right now there is probability that that will give above normal precipitation, at least for the late fall and early winter,” Tardy said.
Tardy warned, El Niño does not always guarantee rain for San Diego.
“Just a few years ago in 2006 and 2007 we had an El Niño — that was actually the start of our last drought.
He said 1976-1977, comparable in numbers and impact to the current drought, was also an El Niño year.
"And not just a weak El Niño year — it was a notable El Niño year. So that’s the variability that we have challenges with," Tardy said.
Tardy said record-breaking conditions are expected to continue through the summer with above average temperatures and increased heat waves.
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