Expect a cold one this winter
It's not far off...and, if you were a fan of last winter's weather, you're in luck. But, if your snowblower needs repairs, you might want to get those taken care of before Old Man Winter arrives.
Many signs point to a likely repeat of last winter's conditions, with cold temperatures and above-average precipitation in much of the Midwest and drier conditions in the Plains, says Don Keeney, meteorologist with MDA EarthSat Weather. Look for one difference from last year, though.
"It should be noted that the coldest conditions should occur earlier in the winter, with December and January being the colder time periods," Keeney says.The reason for the repeat in the winter outlook: The La Nina system that was supposed to be gone by now will likely stay in place through March, says Iowa State University (ISU) Extension Ag meteorologist Elwynn Taylor. La Nina is characterized by colder winter temperatures and the potential for a lot more volatile swings in the mercury than normal.
"A year ago, we had one of the 3 strongest La Ninas in the last 100 years. It did a lot of the things we expected it to do, both in the summer and winter," Taylor says. "Now, we're seeing it restrengthening. Not as harsh or extreme, but similar to last year.
"So yes, the probability looks like a replay of last year, maybe just not as extreme. But, let's just say it wouldn't be smart to do without your snowblower if you are a person who gets tired of shoveling snow."Taylor says La Nina's sticking around because of a factor called the North Atlantic Oscillation (NAO). For the months of January, February and March, the NAO -- a weather phenomenon that causes the gulf stream to "wander around the Atlantic [Ocean]," Taylor says -- comprises a decades-long trend of divergence from average temperatures. Historical records show, from the mid-1950s to the mid-1980s, the NAO index was lower than 0, resulting in lower-than-normal temperatures and greater temperature extremes. Then, from about 1984 to 2004, the NAO index was above 0.
"When NAO is in its negative mode, we tend to have harsher winters from about eastern Nebraska to the east coast," Taylor says. "When it is in positive mode, we have milder winters. It has been mild from about 1984 to 2004 or so, and it's been moving back toward normal or maybe the harsh side since. We have reason to thin we may be going back to 20 years of winters more reminiscent of the 1950s than the 1990s."
The North Atlantic Oscillation (NAO) appears to be trending back below zero in the next few years, a sign of colder winters and more volatile conditions, says ISU's Elwynn Taylor (chart courtesy National Weather Service).
One thing that should be slightly different this year, Keeney adds, is the timeframe for the coldest temperatures of the season. Late January through February was the coldest part of last winter. Look for that window to move up.
"It should be noted that the coldest conditions should occur earlier in the winter, with December and January being the colder time periods," Keeney says.
How could this outlook affect things on the farm next spring? Between now and then, the southern Plains should get at least some much-needed moisture for the winter wheat crop there. But, the moisture will be heavier in the northern Plains and northwestern Corn Belt, meaning some of the issues farmers in those areas faced this last spring could come around next year.
"We do expect some rainfall to return to the southern Plains during October and early November, before they return to a drier pattern by the end of the year," Keeney says. "I would expect there to be problems once again with planting delays in the northern Plains spring wheat areas and northwest Midwest corn areas next spring."