Almanac prediction comes true

Winter is halfway over and, despite fluctuations in precipitation and temperatures, meteorologists say things appear to be on the normal side.

But when one looks at "The Old Farmer's Almanac," a folklorist guide to all things weather that has been published since 1792 and whose 2009 edition went on sale in September, certain anomalies were predicted.

"Normal" is relative in the weather business. And the weather is always a pickle to predict.

Weather service scientists use state-of-the art-technology, satellite tracking and mathematical models to make predictions. The Old Farmer's Almanac predicts weather based on solar activity, climatology and meteorology.

Take the Almanac's summary of the Intermountain region, which includes the Tahoe-Reno area. The wide-swath prediction for November would be some rain, snow showers and seasonable temperatures.

According to the National Weather Service, that's what the Sierra experienced, said meteorologist Brian O'Hara.

"We had precipitation at the first part of November and toward Thanksgiving," he said. "Overall this fall was pretty close to normal temperatures."

This winter we are experiencing a weak La Nina, which is a cooling of Pacific ocean temperatures. La Nina is the opposite of El Nino, which is the warming of Pacific waters during the winter season.

The impact of the La Nina, which was predicted in the Almanac, hasn't been as dramatic.

According to the Almanac, the snowiest periods of the season would be in mid-November, early and mid-December, mid- and late-January and late February.

The Christmas storm, which dumped between 2 to 3 feet of snow at Lake Tahoe and in the Sierra, could easily be lopped into the storm for mid-December, and the storm pattern set up for this weekend could meet the January prognostication.

Still, weather service forecasters, who use science, don't necessarily like to predict

weather more than 10 days out, as several variables set in motion the jet streams that ultimately decide whether or not a storm will reach the region, O'Hara said.

The forecast for the weekend calls for rain and snow showers to continue, with snow above 7,000 feet. Snow levels may lower some, but, as of Thursday, no winter warnings or watches are anticipated. Rain and snow showers could continue through at least Tuesday, O'Hara said.

"These are typical Sierra storms that are lined up," O'Hara said. "There's nothing out of the ordinary."