SD warm streak hits one-year mark

Every month since late 2013 has had abnormally high temperatures

By Robert Krier8:29 P.M.OCT. 30, 2014
14


Kayakers enjoyed a sunshine-filled day at La Jolla Shores in July. / photo by Peggy Peattie * U-T San Diego




Halloween will bring one more scary temperature statistic in a year full of them: San Diego will officially be warmer than normal for 12 straight months as of today.

Complaints about the city’s persistent warmth now stretch back a full, sweaty year.

And after what’s predicted to be a cool and wet weekend to start November, the groaning could resume next week. Thoughts may be turning to sweaters and falling leaves by then, but shorts and sandals likely will be back in vogue. Temperatures at the coast are expected to climb back into the 80s next Wednesday and Thursday.

San Diego has been there, done that many times since Jan. 1. Sixty-one times, in fact — nearly twice as many 80-degree days (or hotter) as in all of 2013.

Related
Is 2014 a historically hot year?

October 2014 will go down as San Diego’s second warmest October on record, less than half a degree below the record set in 1983. September was the city’s fourth warmest, May was the warmest on record, April was the third warmest and January tied for the second warmest. All the other months since October 2013 were at least two degrees warmer than the city’s climatological average.

San Diego’s streak of abnormally warm months is its longest since 1992 and the fifth longest on record.

Since Nov. 1 of last year, the average daily temperature in San Diego — a combination of the high and the low — has been below normal 26 times.

It’s been exactly normal three times.

Warmer than normal? An almost unfathomable 336 times. That’s more than 11 out of every 12 days. The last 60 days have all been warmer than normal.

Warmth like that is great for air-conditioning companies, not so much for furnace installers.

Doug Cooper, director of marketing and customer service for Carini Heating and Air Conditioning in the Midway District, said the company’s AC business was up fivefold at the end of this summer.

“Our business is very climate-related,” Cooper said. “January, our furnace season, was unusually warm, so our business was down. But then it got hot in April, and our business has been going nonstop since then.”

Why the weird warmth that won’t go away?

“Sea-surface temperatures (off the county’s coast) are definitely a factor,” said Alex Tardy, warning coordination meteorologist at the National Weather Service’s office in Rancho Bernardo.

“They are still running three to six degrees warmer than normal.”

Warm coastal waters raise the baseline of how low the temperatures can dip, and they increase the daily highs, Tardy said.

But the warm water, which extends across the entire North Pacific, is not the sole cause of the warmth. Another big factor is California’s three-year drought, the worst in state history.

“When you have very dry soil conditions, you have the potential for extra warmth if you have a warm air mass over you — and that happened several times this year,” Tardy said.

With little soil moisture to evaporate, the sun’s energy goes directly into warming the ground, which then warms the adjacent air.

“We get more of a desert effect,” Tardy said.

The period from Jan. 1 through Oct. 28 of this year was San Diego’s second warmest on record, Tardy said, and the city was by no means alone.

El Cajon, Chula Vista and Palomar Mountain all set records for the period, and Vista had its third warmest stretch.

The past 12 months have been the warmest on record for California as a whole.

The storm this weekend should bring a temporary cool-down locally, with highs in the 60s for the first time since early May.

The storm also is expected to bring a northwest swell that is likely to churn up cooler subsurface waters and lower the temperature of the coastal waters. Cooler waters should help drop the nighttime lows, which have been warmer than normal for all but a handful of times this year.

The Climate Prediction Center, however, doesn’t expect California to catch much of a break. The latest seasonal forecast calls for warmer-than-normal conditions for the November-through-January period across the state.

Looking further back at history, San Diego’s current stretch of warm months would have to last two more years to break the city’s record.

Temperatures were warmer than normal from February 1982 through December 1984, a span of 35 months. No other warm streak has lasted longer than 15 months.

rob.krier@utsandiego.com
(619) 293-2241
Twitter: @sdutKrier

http://www.utsandiego.com/news/2014/...r-temperature/