Weather Watch

Air, sea temperatures are much warmer this year — but will we get an El Niño?

Tessa Lange of Tenera Environmental with one of the 18 seawater temperature recorders positioned around the Diablo Canyon Power Plant. This one was in an intertidal "tide pool" zone.
Tessa Lange of Tenera Environmental with one of the 18 seawater temperature recorders positioned around the Diablo Canyon Power Plant. This one was in an intertidal "tide pool" zone.

If you thought the first half of this year was abnormally warm along the Central Coast, you are correct.

The first six months of 2014 were the hottest ever in California, according to the National Oceanic and Atmospheric Administration (NOAA). In fact, it was nearly 5 degrees warmer than average.

Locally, the Paso Robles Airport maximum temperature averaged 80.2 degrees from January through July this year. Normally in the North County, the high average is 74.5 for this time frame.

So far this year, San Luis Obispo County Regional Airport high temperature has averaged 74.6 or 5.1 degrees warmer than the historical mean.

On the other side of the coin, the minimum temperature appears to be running about 3 degrees warmer in San Luis Obispo County, probably because of lower than average cloud cover that either produces precious rain or gloomy marine overcast.

You see, when the skies are clear at night, more heat from the earth’s surface radiates out in space, producing cooler temperatures. However, there’s been less cloud cover as the California drought intensifies.

The U.S. Drought Monitor map released last week indicates that 58 percent of California is now experiencing “exceptional drought,” the worst category on the agency’s five-level scale or about 22 percent more of the state than the previous week’s maps with most of the expansion occurring in Northern California.

Not only has the atmosphere been warmer than normal, but the ocean has also been at near or at record-breaking levels. That also has also contributed to the above-normal air temperatures.

According to NOAA, the June global sea surface temperature was 1.2 degrees above the 20th century average of 61.5 degrees, the highest for June on record. At the end of July the oceans continue to be well above normal.

Locally, temperature recorders housed in steel canisters and placed at 18 fixed locations near Diablo Canyon Power Plant have recorded near record-breaking temperatures. The Patton Cove monitoring station, which is just south of the power plant in about 10 feet of water, indicates that the warmest July on record occurred in 1983 with an average seawater temperature of 58.8 degrees. This July the seawater temperature averaged 58.7 degrees, just missing the all-time record.

Individual temperature readings at this station reached nearly 65 degrees this past month.

Millions of seawater temperatures have been recorded along the stretch of coastline since 1976 and the average for July is 55.5 degrees. Historically, the warmest seawater temperatures along the Central Coast occur in October, still months away.

It’s still early, but despite these abnormally warm ocean temperatures, the atmosphere has still not responded in a classic El Niño pattern. Currently, the warmest waters are in the central Pacific and not against South America, which normally occurs with classic El Niño’s events.

According to the Climate Prediction Center, the chance of entering into an El Niño condition is about 70 percent later this summer and close to 80 percent this fall and winter. The Australian Bureau of Meteorology has pushed back the start of El Niño to September, and says a strong event is unlikely.

Historically, weak and moderate El Niños events give average rainfall, with some years experiencing above normal precipitation and other years below. However, strong El Niño events can produce about 140 percent of above-normal rainfall for our area.

But please keep in mind, that historical data doesn’t guarantee future rainfall predictions, especially with climate change factored into the equation. At this point, most meteorologist and climate scientists are taking a wait-and-see attitude.

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