Significant Late Winter Storm

Significant Late Winter Storm:

A very large-scale late winter storm moved across the midsection of the USA this week, bringing widespread strong winds and thunderstorms to many states, even tornadoes to Oklahoma, and a mixture of precipitation to southern and eastern portions of Minnesota. Many areas of Minnesota reported over 6 inches of snowfall, and over an inch of precipitation on Wednesday night (March 5) into Thursday morning (March 6).. Some observers reported over 10 inches. There were several reports of wind gusts over 40 mph, and a few over 50 mph:

Jackson reported 56 mph wind gust
Worthington 54 mph wind gust
Rochester 52 mph wind gust

There were widespread school closures by Thursday morning, and several highways in southwestern and south-central Minnesota were closed due to poor visibility from blizzard conditions or large mounds of drifted snow.

From the Minnesota long-term climate station network there were a few new record daily snowfall amounts reported for March 7th:

10.0 inches at Wells (Faribault County
8.1 inches at Owatonna (Steele County)
7.3 inches at Jordan (Scott County)

In addition, because of the combined rainfall/snowfall produced by the storm, there were a number of record daily precipitation amounts reported for March 7th as well.

2.10 inches at Wolf Ridge Environmental Learning Center (Lake County)
1.25 inches at Red Wing (Goodhue County)
1.20 inches at Faribault (Rice County)
1.14 inches at Hokah (Houston County)
1.10 inches at Theilman (Wabasha County)
0.98 inches at Zumbrota (Goodhue County)

A more comprehensive review of this week’s storm can be found at the DNR-Minnesota State Climatology Office web site.

For many observers in the state this storm brought the most snow of the season. This snow is expected to be short-live, as temperatures by Thursday afternoon had climbed into the low to mid 40s F in many areas of southern Minnesota, and forecasts for the coming week call for several days to reach highs in the 50s F and may be even low 60s F across southern portions of the state. The outlook for the second half of March is for temperatures to mainly be well above normal across Minnesota.

Weekly Weather Potpourri:

Slow-moving Tropical Cyclone Alfred was expected to make landfall near Brisbane, Australia on Saturday (March 8), with winds up to 80 mph, significant wave heights over 20 feet and heavy rains. There were already many flight cancellations in play at the Brisbane airport. According to news agency Al Jazeera, it is somewhat rare for a tropical cyclone to strike this area of Australia, but the storm has so far been well forecasted by the Bureau of Meteorology.

The Weather Underground reports this week that both Arctic and Antarctica sea ice extent were below normal for the month of February, continuing long term trends in that direction. The report goes on to say that NASA scientists have calculated that Artic sea ice is declining at a rate of 13 percent per decade as global temperatures continue to rise.

This week’s AGU EOS Bulletin features an article about the potential sustainable use of deep aquifer (400 meters to 3500 meters below ground) ground water to meet fresh water needs and agricultural needs, especially in more arid regions of the world. Some of these deep aquifers have already been tapped, and technologies have improved to make use of them.

MPR listener question:

After the winter storm and blizzard this week, we were wondering what is the historical monthly frequency of blizzards in Minnesota? We thought the most occurred in January.

Answer:

From research published by the American Meteorological Society I don’t know the actual year to year monthly frequencies of blizzards in Minnesota, but I do know historically the seasonal totals have ranged from 0 (in several winters) to as many as 14 (winter of 1996-1997). The absolute historical frequency of blizzards in Minnesota is highest in January, followed by December. After that the order of declining frequency is probably March, February, November, April, and October.

Twin Cities Almanac for March 7th:

The average MSP high temperature for this date is 37 degrees F (plus or minus 11 degrees F standard deviation), while the average low is 21 degrees F (plus or minus 12 degrees F standard deviation).

MSP Local Records for March 7th:

MSP records for this date: highest daily maximum temperature of 73 degrees F in 2000; lowest daily maximum temperature of 4 degrees F in 1932; lowest daily minimum temperature of -16 degrees F in 1960; highest daily minimum temperature of 45 degrees F in 2000, and record precipitation of 1.02 inches in 1874. Record snowfall is 11.5 inches in 1917.

Average dew point for March 7th is 13°F; the maximum dew point on this date is 58°F in 2000 and the minimum dew point on this date is -25 degrees F in 1960.

All-time state records for March 7th:

The state record high temperature for this date is 80 degrees F at Winona (Winona County) in 2000. The state record low temperature for this date is -44 degrees F at Embarrass (St Louis County) in 1996. The state record precipitation for this date is 1.56 inches at Lynd (Lyon County) in 1915. The statewide snowfall record for this date is 15.0 inches also at Lynd (Lyon County) in 1915.

Past Weather:

A late season winter storm brought a mixture of rain and snow to Minnesota over March 6-7 of 1946. The heaviest snow was in the western counties where 8 to 12 inches was measured in many areas, with drifts of 5 feet. School were closed in some areas.

March 7 of 1955 brought mid-winter cold to Minnesota with subzero temperatures thoroughly covering the state. Many northern communities reported temperatures of -30°F or colder. Cass Lake only reached an afternoon high temperature of -3°F.

Perhaps the warmest ever March 7th in state history was in 2000 when climate stations in 50 Minnesota counties reported afternoon temperatures of 70°F or higher. There was virtually no snow cover in the state on that date as well, so in many places overnight minimum temperatures remained in the 40s and 50s F.

On March 7 of 2003 NOAA reported that Lake Superior was 90 percent ice covered, a rare occurrence in the modern era. This was not surprising as January-February in combination that winter had been one of the coldest periods of the new millennium across the Great Lakes region. Also, as a result of the cold winter, soil frost depths were as deep as 60 inches in Minnesota on March 7th of that year.

Outlook:

Strong warming trend will begin this weekend and run through early next week, bringing above normal temperatures to the state. There will be a dip in temperatures during mid-week, then a return of warmth towards the end of next week with a chance for rain or snow (north) by Friday and Saturday.