Winter temperatures affected by snow cover

Winter temperatures affected by snow cover:

Our MPR Morning Edition chat last week provoked several listener comments about the effects of snow cover on temperatures in Minnesota. Indeed, they are significant and measurable. Nearly all of the daily high temperature records during the winter months are from days without snow cover. Some examples:

Highest temperature in December is 74°F on December 9 of 1939 at Wheaton (Traverse County, zero snow cover.

Highest temperature in January is 69°F on January 24, 1981 at Montevideo (Chippewa County), zero snow cover.

Highest temperature in February is 73°F on February 26, 1896 at Pleasant Mound (Blue Earth County), zero snow cover.

Looking at the winter season (December through February) the highest daily temperatures that I can find with the presence of snow cover are in the upper 50s to low 60s F. This suggests that the presence or absence of snow cover may affect the extreme warm daily high temperatures by as much as 9 to 12°F.

In the Twin Cities 150-year climate record the highest winter season temperature (Dec-Feb) is 68°F on December 1, 1998. There was no snow cover and golf courses were open for play. The record coldest winter season temperature reading is -41°F on January 21, 1888 with at least 15 inches of snow cover.

For southern Minnesota climate stations, the effect of snow cover on daily maximum and minimum temperatures can be illustrated by computing them for today’s date (February 10) using two sets of conditions, with and without snow cover. Here are the results for two climate station:

Albert Lea with snow cover: average February 10 maximum temperature 23°F, minimum temperature 4°F.

Albert Lea without snow cover: average February 10 maximum temperature 36°F, minimum temperature 17°F

Marshall with snow cover: average February 10 maximum temperature 24°F, minimum temperature 3°F

Marshall without snow cover: average February 10 maximum temperature 34°F, minimum temperature 15°F.

These data from Albert Lea and Marshall climate histories also suggest that snow cover has about a 10 to 12°F impact on temperature readings.

Despite having 8-12 inches of snow cover, a few places like Cass Lake and Detroit Lakes reported 50°F temperatures on Wednesday this week, under bright sun and with south winds. Imagine what their temperatures might have reached without snow cover!

Minnesota Climate Adaptation Partnership Program kicks-off a new seminar series;

2023 UMN Climate Adaptation Partnership monthly webinar series resumes on 2/21 at 12pm with a session to learn about the new statewide MN Climate Action Framework that identifies actions to achieve a carbon-neutral, resilient, and equitable future. Individuals who are interested can visit the web site below for details and free registration.

This group of climate adaptation advocates and practitioners is terrific to network with in order to keep up with the latest news in Minnesota about adapting to our changing climate.

Weekly Weather Potpourri:

A recent study published in Nature Communications found that over 15 million people globally are exposed flooding threats from glacial lakes. More and more glaciers are melting and creating large, and sometimes unstable lakes which pose a flood risk to surrounding or downstream communities. More than half of the globally exposed population are found in just four countries: India, Pakistan, Peru, and China.


This week’s AGU-EOS Bulletin features an article about the role of insurance in climate adaptation, especially to manage risk of tropical storm damages. The study states that “depending on how tropical storms evolve with a shifting climate, insurance policies would need to cover 58% to 84% of direct asset losses—not 50%, the historical average.” They go on to say that a single approach to insuring against damages from tropical storms does not fit all nations or geographies. Many other details about the risks to local economies must be taken into account.

A recent article in Scientific Reports documents how honeybee colony loss has been linked to parasites, pesticides, and impacts of extreme weather. As reported by Science Daily “this research team found that several stressors impacted honeybee colony loss at the national level, including the presence of nearby pesticides, frequent extreme weather events, and weather instability.”

MPR listener question:

With close to 56 inches of snowfall for this season so far in the Twin Cities, some of us were wondering if it can sharply tail off in March. Has there ever been a March with no snowfall?

Answer:

The Twin Cities snowfall record is 139 years old. It shows one year when March did not bring any measurable snowfall. That was in 2010. March of 1981 brought only 0.1 inches of snowfall, and there have been 7 other Marches that brought less than 1 inch. On the other hand, there have been 8 Marches that brought 20 inches or more.

Twin Cities Almanac for February 10th:

The average MSP high temperature for this date is 27 degrees F (plus or minus 12 degrees F standard deviation), while the average low is 11 degrees F (plus or minus 13 degrees F standard deviation).

MSP Local Records for February 10th:

MSP records for this date: highest daily maximum temperature of 49 degrees F in 1877; lowest daily maximum temperature of -8 degrees F in 1899; lowest daily minimum temperature of -24 degrees F in 1885; highest daily minimum temperature of 35 degrees F in 2009; record precipitation of 0.62 inches in 2013. Record snowfall is 5.9 inches in 2019.

Average dew point for February 10th is 9°F; the maximum dew point on this date is 34°F in 2005; and the minimum dew point on this date is -37 degrees F in 1923.

All-time state records for February 10th:

The state record high temperature for this date is 58 degrees F at Granite Falls (Yellow Medicine County) in 2017. The state record low temperature for this date is -49 degrees F at Tower (St Louis County) in 1899. The state record precipitation for this date is 1.69 inches at Montevideo (Chippewa County) in 1965. Record snowfall is 20.0 inches also at Pigeon River (Cook County) in 1939.

Past Weather:

An Arctic air mass gripped the state on February 10, 1899. Morning low temperatures were minus 20s F in the south and minus 40s F in the north. The afternoon high temperature only reached -24°F at Roseau, as the state was also blanketed with heavy snow cover.

Persistent cold and heavy snow prevailed across Minnesota over February 9-12, 1965. Many climate stations reported between 10 and 15 inches of snowfall. Some schools were closed in southern Minnesota counties. Fairmont reported nearly 20 inches of snowfall.

February 10 of 1977 brought an early taste of Spring to many citizens as afternoon temperatures soared into the 50s F in over 30 Minnesota counties. Sunny skies and moderate south winds prevailed. The low temperature at Canby never fell below freezing.

Outlook:

Continued warmer than normal temperatures over the weekend and through the middle of next week. There will be increasing cloudiness later on Tuesday with a chance for rain in the southe and some snow in the north. Continued chances for rain/snow on Wednesday and early Thursday, as temperature drop to colder than normal values towards the end of next week.