Networx

Posted by Steve Graham | Oct 11, 2010

La Nina Winter? Gardeners Beware and Prepare

A little girl could wreak havoc on your garden this winter and spring. The weather pattern known as La Niña, or the little girl, is already gathering strength in the Pacific. The National Oceanic and Atmospheric Administration (NOAA) predicts a moderate to strong La Niña system through May. This is likely to lead to unusual weather, ranging from storms in Seattle to droughts in Dallas.

La Niña, the meteorological opposite of El Niño, is characterized by low water temperatures at the tropical Pacific Ocean surface. However, it has far-reaching impacts. La Niña typically brings lousy surf in cold water, so surfers know what they are getting into.

For most of North America, La Niña will be less predictable. The weather system brings unusual and unpredictable weather patterns, but it typically means more storms, rain and snow through winter in the Pacific Northwest, and less precipitation and fewer storms across the southern half of the United States.

More than a century ago, Peruvian fishermen first identified El Niño as an unusually intense warm current around Christmas. It has since been intensively studied and defined as part of a cyclical weather pattern. Only in the past two decades has the other end of the cycle - La Niña - been identified and studied.

Since then, meteorologists have tracked significant global weather changes during La Niña years. The greatest temperature variations are expected in Texas and New Mexico, as well as the northern tip of Alaska. New Mexico and Arizona, not known for much winter precipitation, can expect even drier than average conditions.

The report also shows past impacts, averaged across the past 18 La Niña episodes. Arkansas and Louisiana saw the greatest drop in precipitation from an average year. Arkansas is bracing more of the same this year. The National Weather Service reports more than half of Arkansas is already in moderate to severe drought, and the drought conditions will continue spreading through the state.

Gardeners throughout the southern half of the United States should prepare for a hot, dry winter and pay heed to established plants that typically can be ignored all winter. They may suffer if they are expecting more precipitation.

On the other hand, don't overcompensate now with too much irrigation. La Niña weather is unpredictable - even more unpredictable than every other year in the recent past. Keep an eye on this little girl. She could make things interesting.

blog comments powered by Disqus