December a roller-coaster weather month
By Tim Krohn [email protected]
The year is ending with a potpourri of weather in December, starting the month with rain, some decent snows, then the bitter cold, wind and heavy snow last week, with the waning days of the month relatively balmy.
Meteorologist Brent Hewett of the National Weather Service Twin Cities office in Chanhassen said the Mankato region will finish the month at about 3 degrees below the average mean temperature for December.
The area was almost 6 degrees below normal as of Wednesday, but the warmer final days will take the edge off the monthly average temp. “Having these higher temps at night now really helps.”
As for precipitation, the Mankato region will be a half inch to 1 inch above normal for the month.
“You’ve had about 12 inches of snow for the month. We’re certainly not lacking in the snow department,” Hewett said.
He said the extreme cold is what highlighted the month.
“The temperatures last week were very cold for this time of year. It’s more typical to see that in mid- to late-January or in February. It’s definitely been a while since we had a cold December.”
Tom Hoverstad, a scientist at the University of Minnesota Southern Research and Outreach Center in Waseca, said his area has gotten even more snow in December.
“We’re up to about 19 inches of snow while our average is about 11.”
After years with relatively non-descript Decembers, the recent cold and storm were notable.
“We had a genuine blizzard. It was a huge and rare system.”
Hoverstad said the howling winds, while causing whiteout conditions, kept temperatures from sinking even lower.
“We were in the 10-below range, but you’d have to get to 20-below this time of year to set records. You need calm to get down to 20- below. This one had a lot of wind so it didn’t get that low.”
With the summer and fall bringing above average temps Hoverstad said the below normal temps for December were a change.
“It’s probably the first cooler-than-average month we’ve had since March or April of this year,” Hoverstad said.
Drought eased
The recent precipitation has lessened the drought in southern Minnesota, according to this week’s Drought Monitor map.
A strip of extreme drought that had stretched from the southwest to northeast across southern Minnesota, including through northern Brown and Nicollet counties and all of Sibley and Le Sueur counties, has been reduced to severe drought. Counties southeast of Mankato are in only a moderate drought.
Hewett said the snowfall in December brought about 1½ inches of liquid. But with the ground frozen, some of the snow that melts will run off rather than getting in the ground.
“We still need a wet spring,” Hewett said. “It helps to get a snowpack and some precip this time of year, but I’ll hold my celebration until we get a wet spring.”
Hoverstad said the above-normal precipitation isn’t going to do much to recharge soil moisture.
“It’s good but I’m not sure it’s going to do much for farm soil moisture. It’ll be good for filling up streams and lakes and things.”
Mild weekend
New Year’s Eve will be relatively mild with some scattered snow showers possible.
Another potent storm system is possible Monday into Tuesday. Some areas could see rain while others could see heavy snowfall.
Highs will be around 30 through New Year’s Day and a high of 35 for Monday in the Mankato area. It will then cool down some for a few days, with temperatures predicted to rebound to about the 30s for highs the following weekend.