Temperatures, Humidity Go Up, Down Like Yo-Yo

Muggy weather and record-breaking temperatures Tuesday recalled last year’s relentless heat wave, but meteorologists say this week’s sticky weather is not a harbinger of another summer siege.

A freak weather front carrying moisture from central Mexico swept across the desert early Tuesday morning, generating hot air and high winds throughout the county. No damage was reported.

On Tuesday morning just after midnight, winds were recorded at 12 m.p.h. at Lindbergh Field. Just 17 minutes later the wind was blowing at 27 m.p.h.

Although no rain was recorded, the National Weather Service received reports of thunder, lightning and showers from

several areas of the county Tuesday. National Weather Service forecasters said thundershowers are expected today in the mountains.

The warm front raised the temperature to a record 95 degrees at Lindbergh Field by 11 a.m. Tuesday. It surpassed the record of 86 set in 1968. Humidity also was high Tuesday, but skipped around --87% at 3 a.m., 76% at 8 a.m., 46% at noon, 71% at 3 p.m. and 51% at 8 p.m.

After noon, as winds shifted from the southeast to the northwest, the temperature dropped 14 degrees in one hour at Lindbergh Field, falling to 75 degrees by 1 p.m.

But the temperature, like the humidity, continued to go up and down like a yo-yo throughout the day.

Winds shifted again to the southeast by 7 p.m. Tuesday, sending the temperature at the airport back up to 81 degrees.

Peak highs were 100 in Santee and Fallbrook, 86 at Mt. Laguna, 90 in Point Loma, 98 in Lemon Grove, 101 in Vista, 89 in Oceanside, 84 in Del Mar, 90 in Coronado and 93 in Chula Vista.

San Diego County will remain under the influence of the moist subtropical air mass for at least two days, National Weather Service forecaster Richard Stitt said, but temperatures should drop slightly.

Fears of a second summer of subtropical moisture with record-breaking warm nights and days found San Diegans wondering about long-range forecasts.

According to meteorologists at Scripps Institution of Oceanography, the chances of such a summer are remote.

“I would really be surprised to see a prolonged spell like we saw last summer,” said Dan Cayan, a Scripps climate researcher. “We may have episodes, but statistically it is most unlikely. It was probably a 1-in-20-year sort of summer.”

Research meteorologist Jerome Namias pointed out that last week’s heat wave was extremely dry. He said it may be warm this summer, but not necessarily muggy.

“I think it is going to be a summer in which the western part of the nation is warm while the East and Northeast remain cool,” Namias said. “These two things go together as self-supporting, self-aggravating situations because of wind patterns.

“Last summer was moist and hot. There will be some of those days. My guess is that they will be interspersed with dryness too. It won’t be so persistently moist. Although it will be a mild, warm summer, the degree and duration won’t be equivalent to last summer.”

High-pressure systems last summer centered over Texas and New Mexico, he said. This year it appears that such high-pressure systems will center closer to California --as happened last week, when humidity was abnormally low and the weather tinder dry.

A high-pressure system centered east of San Diego County will keep the weather warm at least through Thursday in all parts of the county--and the moist air mass will stick.

Foggy morning skies are expected to clear to partly cloudy skies and hazy sunshine, except in the mountains, where thundershowers are expected. Highs at the shore are expected to be in the 70s, and the ocean water temperature has warmed to 69 degrees.

Daytime highs in the 80s are expected along the coastal strip, with nighttime temperatures in the high 60s.

Inland highs of 94 to 104 should cool to the 60s at night.

Despite cloud-churning skies, mountain weather is expected to be hot, with highs around 90 and lows in the 60s.

Desert highs of 104 to 110 degrees are expected.