El Nino, La Nina make forecasting less predictable

Meteorologists have access to satellites, computers and other modern technology to aid them in forecasting the weather.

But take away the eastern Pacific Ocean weather phenomena known as El Nino with its warmer-than-normal surface temperatures and La Nina with its colder-than-normal surface temperatures and forecasting is less certain.

"Those are the two extremes and right now we're in between them, in the neutral zone," said Randy Cerveny, professor of geography at Arizona State University.

"With El Nino and La Nina we know what weather patterns set up.

Without them forecasting becomes a crap shoot so that you're just as likely to get rain or snow as sunshine and hot weather."

A La Nina that is weakening currently is in place, according to Cerveny and John Adair, meteorologist with the National Weather Service in Las Vegas.

"October had a fairly wet ending, then the pattern changed," Adair said.

"A high pressure system settled over the southwest and has kept us pretty dry (in November and December), and that system is mainly attributable to La Nina."

A weak upper low pressure system off San Diego is expected to cross Southern California and Arizona tonight, though it will bring only cloudiness and no precipitation for Mohave County, Adair said.

A cold front is expected to pass through this area Monday night bringing windy conditions and cool temperatures on Tuesday but still with no rain, Adair said.

Information supplied by the ASU Office of Climatology indicates average precipitation for Kingman is .74 inches in November and .94 inches in December.

That office recorded no measurable rainfall in December and just .11 inches for November in Kingman.

Dry conditions are expected to continue into early February due to little or no movement of the high pressure system now over the southwest, Cerveny said.

The average maximum and average minimum temperatures for Kingman are 63.6 and 38.7 for November and 54.7 and 31.8 in December, according to the ASU Office of Climatology.

Data for November indicates the temperature reached 64 or higher only on each of the last three days of the month.

A minimum temperature of 38 or below occurred on 25 of those days, including readings below 30 each night during Nov.

13-20.

December was warmer than normal in Kingman.

Daytime temperatures reached 55 degrees or higher on 25 of 31 days.

Nighttime lows dipped below freezing 16 of 31 days.

"The warmth of last month was the result of the large bubble of high pressure over the southwest, which kept cold and storms to the north," Cerveny said.

"That bubble looks like it will stay in place for the next month, so precipitation becomes iffy."

La Nina, while weakening, is expected to remain a factor in Arizona's weather for the next three months, Adair said.

Temperatures in Las Vegas were 4.8 degrees below normal in November and 3.8 degrees above normal in December, Adair said.

The latest update from the Climate Predictions Center in Silver Springs, Md., indicates Mohave County should have warmer-than-normal temperatures and slightly below normal precipitation for the remainder of the winter, Adair said.