The Free Press, Mankato, MN

Local News

January 8, 2012

What in the name of winter is going on?

MANKATO — The “winter” weather in southern Minnesota is starting to sound like a broken record.

High temperature records were broken Thursday and Friday and the records for today (46 degrees in 2002) and Tuesday (39 degrees in 2007) are in clear danger of shattering with highs of near 50 forecast for each day.

“Weather has a tendency to feed on itself,” said KEYC meteorologist Russ Joseph. “The adage is true that winter tends to feed on winter.”

And this year, winter is having an extended picnic, feasting on warm western air rather than its typical diet of icy Canadian chill. Just look at Thursday, when temperatures topped 60 in several southwestern Minnesota towns, to see how unusual the winter has been.

“That’s never happened — ever — in Minnesota where we had a 60 degree day the first week of January,” Joseph said.

It was more mild in Marshall (62 degrees) than Madrid (57), warmer in Canby (63) than Cairo (62), and as pleasant in Appleton as Athens (both 59). It wasn’t as balmy in Benson (59) as Bermuda (66), but it was close.

Muchas gracias

In Mankato, the half-century-old record high temperature of 45 degrees in 1958 was demolished by Thursday’s 52 degrees. Friday’s 46 degree high was also a record.

While the past week has been extraordinary, the entire season has been a stroll in the park compared to typical Minnesota winters. November? Mankatoans didn’t have to go as much as a week between 50-degree temperatures, including 63 degrees on Thanksgiving, and the coldest temperature was 10 degrees on Nov. 17, according to National Weather Service statistics.

December? There was a 55-degree day on Dec. 9, and it reached 50 the day after Christmas. Ten days topped 41 degrees and only 12 days didn’t exceed the melting point.

The thanks (or curses from snowmobile and cross country ski enthusiasts) can go to La Nina, the phenomenon that occurs some winters where parts of the Pacific Ocean cool, Joseph said. Temperatures in the massive ocean have a lot of impact on upper air wind patterns, commonly called the jet stream.

“Normally, at this point it’s a lot farther south,” he said of the upper air stream that flows from west to east across North America. “Right now, it’s hovering right over us.”

That means warmer western air is streaming over Minnesota and frigid Arctic air is being blocked. It’s still plenty cold in the sunless north. The high temperature in North Pole, Alaska, for example, is expected to be -19 today. But unlike other years, Alaska and northern Canada aren’t sharing that frigid air with the Upper Midwest.

“That cold air is getting manufactured, but it’s just getting bottled-up up there,” Joseph said.

Fully absorbed

The lofty air stream is also playing a role in keeping moist air from the Gulf of Mexico from reaching Minnesota, helping to explain the absence of snow storms, he said. Just 8 inches of snow have fallen at KEYC’s North Mankato studio this year compared to 38.5 inches by this date last year.

 Snow is a key element in Joseph’s previous point about how winter can feed on itself. The fact that there’s been so little snow has contributed to the mild temperatures this year.

“Brown grass absorbs 75 percent of the sun’s energy,” said Joseph, with the rest reflected back into space. “Fresh snow only absorbs about 10 percent of the sun’s energy.”

So brown grass allows the daytime temperatures to rise higher than would happen with a sparkling blanket of white snow. The lack of snow also means there isn’t much melting and evaporation, processes that consume energy that otherwise can feed higher air temperatures.

The brown landscape was a key contributor to those unheard of temperatures on Thursday.

“It would have been nearly impossible to get that warm if we’d had snow on the ground,” Joseph said.

If the snow continues to stay away, an early and warm spring would be likely. But Joseph won’t touch that kind of long-range forecast with a 10-foot snow board.

“It’s Minnesota, so in the flip of a switch we can go right back to terrible winter weather,” he said.

180 degrees difference

There’s another reason this winter feels so warm, and it’s psychological rather than meteorological. The horrendous winter of 2010-11 is still fresh in most Minnesotans’ minds, and that makes the contrast with this winter even more striking.

A snow and ice storm came on Nov. 13, 2010, and the misery didn’t really let up until April.

Last winter, it was 54 degrees on Nov. 11 and 50 degrees wasn’t seen again for the rest of November, for all of December, all of January, all of February and all of March. Finally, on April 2, 2011, it reached 54 again. This winter, 50-plus-degree days have come like clockwork.

Mankato hasn’t seen a below-zero temperature the entire winter so far. Last winter, December brought lows as frigid as -15 and January offered five days where the high temperatures never reached 10 degrees, according to Weather Service statistics. The first 23 days of January a year ago included lows of zero or below on 13 days, including -15, -17 and -24.

There was a January thaw last year. It lasted a few hours on Jan. 28 when the high temperature was 34. No other day that month topped the melting point. In February, nine more nights dropped below zero and March 4 tossed in a -4.

Joseph is a more popular guy this winter than last as people talk to him about their outdoor activities.

“I tell them I only take credit for the good, not the bad,” he said.

And there is some comparatively bad weather coming after the balmy temperatures predicted for today and Tuesday. The highs in Mankato will probably be around 30 on Wednesday, dropping to the upper teens by the end of the week. There’s even a chance of snow later in the week.

As Minnesota moves into what is historically the coldest stretch of the winter, high temperatures just above or below 20 are basically the norm. But after the past few months, Mankatoans might react like a tourist from Florida by Thursday or Friday.

“Compared to what we’ve had,” Joseph said, “it’s going to feel really cold.”

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