Spring starts today, sort of
Published 9:25 am Tuesday, March 1, 2011
Spring has finally sprung.
Well, maybe not according to your calendar. However, today does mark the first day of the 2011 meteorological spring.
The meteorological seasons are a way to measure seasons based on weather patterns. These differ from the season dates typically marked on calendars, which notes the astronomical seasons, and are used in large part for record keeping purposes.
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While astronomical spring this year runs March 20 through June 20, meteorological spring runs March through May.
According to University of Minnesota Extension climotologist Mark Seeley, the meteorological seasons make it easier for those who study climate science to figure statistics for the season.
“The latitude band is better because the essence of soil thaw and loss of frost in the soil from the Minnesota winter corresponds more closely to March, April and May,” Seeley said. “The bottom line is for climate science; it’s better to block the year into four three-month periods to run simple statistics on.”
He said most of the middle bands of latitude, not just in the U.S. but around the globe, observe and calculate climate statistics based on the meteorological season.
In recapping meteorological winter 2010-2011, which spanned December 2010 through February 2011, Seeley said three things stood out in his calculations.
The first was the above-normal snowfall.
According to Rick Ashling, who submits Albert Lea’s snowfall data taken at the wastewater treatment plant to the Chanhassen bureau of the National Weather Service, the snowfall total in Albert Lea for the 2010-2011 meteorological winter capped out at 51.5 inches: 33 1/2 inches in December, 11 inches in January and 7 inches in February.
Shawn Devinny, meteorologist with the Chanhassen bureau, said this was the fourth snowiest meteorological winter on the books for Albert Lea.
He said looking over the entire season, to date, Albert Lea sits at 20th in the rankings for total 2010-2011 season snowfall. That’s based on records that span all 365 days of the year. He said, in Minnesota, snowfall can occur outside of the astronomical and meteorological winter seasons, they track their statistics based on the entire year.
“Because we get snow in November, and sometimes even in October, and it spans through April, we track from July through June,” he said. “Look at March. It’s huge for snow, and it’s not included in the meteorological season.”
Seeley said the second thing that stood out this meteorological winter was the persistence of snow cover.
“We got pretty good snow cover the first week in December and it’s been with us pretty continuously, unlike previous winters where we saw it depleted and could see open ground,” Seeley said.
The third highlight of this meteorological winter was that temperatures have been consistently cooler than normal, which has allowed the snow to persist.
Devinny said that although the radar is showing below normal temperatures for the next couple of weeks, the longer the cold hangs on, the worst things could get in terms of spring flooding.
“We want it to be in the mid-30s with refreezing at night,” Devinny said. “If we jump straight into the 50 and 60 degree days, that could cause fast flooding.”
Seeley said his No. 1 concern this spring is the threat of flooding.
“All communities along Minnesota watersheds should be prepared for what’s going to happen this spring,” he said. “March is going to be the trump card here. It’s going to be a key month for the entire season, whether we’re wetter or drier than normal.”
In fact, Moorhead is calling for volunteers starting Tuesday to help make 1 million sandbags to hold back flooding expected this spring. Across the Red River, Fargo, N.D., is nearly halfway to its goal of 3 million sandbags.
Devinny also said the winter rains and refreezing, along with above-average snow, also means there’s more water locked into the snow, which could add to flooding concerns when spring temperatures begin to thaw the landscape.
December 2010 measured in at the second snowiest December in Albert Lea history, Devinny said, with 33 1/2 inches of snow for the month. December’s snowfall record was set in 2000 and measured in at 34.6 inches of snow for the month.
This winter makes this list
Top 5 snowiest winters in Albert Lea, based on meteorological seasons
1. 56.2 inches 1935-36
2. 56 inches 1928-1929
3. 54 inches 1908-1909
4. 51.5 inches so far 2010-2011
5. 47.1 inches 2000-2001
This winter doesn’t make this list
Top 10 snowiest winters in Albert Lea according to the National Weather Service, based on 365 days of each year, from July through June:
1. 75 inches 1928-1929
2. 70.8 inches 1935-1936
3. 66.2 inches 1974-1975
4. 65.2 inches 1978-1979
5. 65 inches 1908-1909
6. 64.7 inches 1896-1897
7. 64.5 inches 1983-1984
8. 64 inches 1916-1917
9. 62 inches 1909-1910
10. 61.3 inches 2006-2007