GRAND FORKS -- Red River Valley residents are in for a colder and possibly snowier than normal winter, according to a forecast released Thursday by the national Climate Prediction Center.
With a second year of La Nina conditions in the Pacific Ocean, the agency's winter outlook for the Northern Plains says there is an increased likelihood of colder and wetter weather December through February.
Mark Ewens, senior hydrometeorologist technician with the National Weather Service, said eastern North Dakota and northwestern Minnesota tend to experience colder than normal winters during a La Nina year.
This is the second consecutive year the phenomenon has been in effect, a relatively rare occurrence in meteorology. The system is "considerably weaker" than last year, but Ewens said it still will likely make for a frigid winter.
But it's a little harder to know what La Nina will mean for the region's overall precipitation.
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Grand Forks typically sees 4 to 5 inches of water content in its snow from November through March, Ewens said, while Fargo gets an average of 5 inches or more.
The Red River Valley will likely see its total winter precipitation remain close to normal this year, he said.
But La Nina could lead to a snowier than normal winter.
"That makes sense from the standpoint that typically when you're colder than normal, you have more frequent fluffy, drier snows and more snowfall accumulation without moisture," he said.
Grand Forks has a normal yearly snowfall of about 46 inches. Fargo normally gets about 50 inches.
But Ewens pointed out that snowfall totals can vary widely from year to year.
"That's just the historical average," he said. "That really is not a prediction of what will happen in the future."
Ewens said meteorologists instead tend to look at the actual snowfall recorded over the past 30 years to determine what the region might expect. From 1981 to 2010, Grand Forks has seen as little as 17 inches of snow in 1981-1982 and as much as 98.6 inches in 1996-1997.
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The city's normal range -- which means the actual snowfall for a year falls within the range about three-quarters of the time -- is 25.8 to 65.5 inches.
That range has increased in recent decades to account for the snowy winters the region has experienced almost consistently since the mid-1990s, Ewens said. Grand Forks has averaged 37 inches of snow each year since 1890, but has experienced an average of 45.6 inches since 1981.
Because the La Nina is in effect, Ewens said he expects the city might approach the high end of the normal range this year and end up with more than 60 inches of snow.
La Nina winters tend to produce the most snowfall between Thanksgiving and Christmas and late February to mid-March, he said. That's because it's usually too cold in January and February to get enough moisture to produce heavy snowstorms.
Ryan Johnson is a reporter at the Grand Forks Herald, which is owned by Forum Communications Co.
