A Near Normal Year Weather-Wise

A  near normal year weather-wise is what Leon Osborne, president of Meridian Environmental Technology in Grand Forks, ND predicts for growers in this region in 2008.

He says three dominant conditions will impact 2008 weather:  moderate La Nina conditions, strong polar circulation, and a divided North American jet stream.

La Nina conditions (caused by cold eastern Pacific tropical sea surface temperatures) point to a very cold winter. Since there is a three-to-five month lag for La Nina’s effects to become evident in our area, it means cooler and dryer weather this spring.

Strong polar circulation – the strongest we’ve seen in ten years – also points to more cool air moving into the region from the north throughout the winter and into spring. It shouldn’t, however, have a large impact on the growing season, he says.

And, for the third consecutive year, Osborne says we’ll see a split structure of the North American jet stream.  This, he says, results in episodes of extreme conditions, reminiscent of the winter of 2004-05.

As for the 2008 growing season in our region, Osborne says their prediction models suggest near normal precipitation and near normal temperatures.

• Winter/Early Spring – Below normal temperatures and near normal precipitation.
• Early Spring/Mid-Summer – Above normal temperatures and near normal precipitation for the beginning of the growing season, and a strengthening of drought conditions in Montana and western North Dakota.
• Mid-Summer/Fall – Near normal precipitation and temperatures.  A rare “average” year.

How will 2008 weather compare to last year?
Osborne says that North Dakota as a whole last year had slightly above average precipitation, as rains in August provided a good additional boost to conditions.  “However,” says Osborne, “as we have seen for years, there was a significant drop off in this precipitation (relative to the long-term average) as you look from east to west.” He says this recent trend will continue this year where we will have near normal conditions.  The exception will be in the western portion of the region, where excessively dry conditions will prevail near the end of summer.

In closing, Osborne says, “don’t put drought completely out of your mind.  For 2008 to 2010, expectations are that deficit moisture conditions will develop.”  He says indications are that the excessive wet period we’ve experienced since 1992 is coming to a close.