November 18, 2010 in Washington Voices

Warmer world average cooling off as region sees wetter winter coming

Randy Mann
 

Since late summer, I’ve been talking about the new La Niña, the cooler-than-normal sea-surface temperature along the equatorial regions. During the winter of 2009-’10, we had an El Niño, the warmer sea-surface temperature, which resulted in less snow for our region.

During the record-breaking snowy winters of 2007-’08 and 2008-’09, we were influenced by La Niña and little sunspot activity.

With the expansion of a new La Niña in the past several months, global temperatures have dropped significantly in October. This information is based upon the Remote Sensing Systems dataset.

The data shows that global temperatures climbed to 0.608 degrees Celsius above the long-term normal in July 2010, then dropped to just 0.293 degrees above the average in October.

Scientists say that the drop from July is “significant and very steep, losing more than half of the temperature anomaly since July.” The last time we were near this temperature was in October 2009 when the RSS reported 0.282 degrees Celsius.

According to some scientists, “the rise and fall of global temperatures this past year approximates a square wave.” They believe that a moderate to strong El Niño followed by a moderate to strong La Nina is the cause of this drop.

The Southern Hemisphere’s average temperature has dropped the most. Readings were near 0.80 degrees above normal in July and approximately 0.27 degrees in October.

The Earth’s averaged satellite-based temperature of the lower atmosphere also dropped in October. But the decline was not as steep and remains higher, at approximately 0.4 degrees Celsius.

Many scientists expected the drop, mainly due to the much cooler waters near the west coast of South America and along the equator. However, no one is certain on whether this recent cooling will continue or how long La Niña will be with us. I believe the Earth’s temperature will rebound a bit when La Niña finally weakens in 2011.

It still looks favorable for moderate to heavy snow during the full moon lunar cycle just ahead of the Thanksgiving weekend, especially above 3,500 feet. This would be good news for the area’s ski resorts.

Assuming that La Niña maintains its current intensity, I still see at least 20 percent more snowfall than normal from late November through late January before tapering off in February and March. The chances of a brilliant white Christmas are a little better than 50 percent in Spokane but near 70 percent in areas north and east of Spokane.

Contact meteorologist Randy Mann at randy@longrange weather.com.


Thoughts and opinions on this story? Click here to comment >>

Get stories like this in a free daily email