Preliminary Climate Summary for March

Preliminary Climate Summary for March:

March will wind up as a warmer than normal month, with most climate stations reporting a mean monthly temperature from 3 to 6 degrees F above normal. Extreme temperature values for the month ranged from -30 degrees F at Cotton (St Louis County) on the 2nd to 65 degrees F at Granite Falls (Yellow Medicine County) on the 8th…although this temperature may be surpassed by high temperatures on Monday or Tuesday of next week. Minnesota reported the coldest temperature in the nation 5 times during March of 2020.

Although precipitation for the month to date has been less than normal, the forecast calls for better chances for precipitation during the last 4 days of the month, with some expected amounts over 1 inch. This may bring monthly totals closer to normal, or even push them above normal. Most climate stations are about a half inch below normal for the month as of Friday, March 27th. Some of the wetter areas of the state included portions of Steele, Winona, and Houston Counties which have reported over 2 inches of precipitation this month. The snowiest place this month was Isabella (Lake County) where over 17 inches of snowfall was measured. Many other areas of northern Minnesota reported over a foot of snow in this March.

Overall the month was a good one for diminishing the threat from spring snowmelt flooding, which has been minor to moderate in only some places. Temperature fluctuations above and below the freezing mark helped meter out the thawed snow- pack, and this was enhanced by higher than normal wind speeds. Many days produced wind gusts over 30 mph and several days there were gusts over 40 mph. Snow cover was all but lost across the southern part of the state, and many southern Minnesota lakes began to lose their ice cover. Over half a dozen lakes have already lost their ice.

Apology for No Broadcast

Unfortunately, the phone lines at the Minnesota Public Radio studio in St Paul were out of order on Friday, March 27 preventing the usual broadcast of the WeatherTalk chat with Cathy Wurzer. I am sorry for this. Hopefully in these challenging times, this issue will be cleared up. Thanks for your patience.

Weekly Weather Potpourri:

NOAA’sClimate.gov web site this week features a number of activities related to climate and energy that can be done by students and their parents at home while they are restricted by the coronavirus pandemic. These are excellent for their engaging content as well as their lessons.

Experience Magazine features an article about how to make decisions that affect your carbon footprint in everyday life. They include an examination of the trade-off features in (1) planning a wedding; (2) hosting a dinner party; (3) or taking a vacation. This might be a fun exercise to try with your family and friends.

Brian Donegan of the WeatherUnderground features a discussion of tornado distribution across the USA over the 1991-2010 period. He also talks about the distribution of tornado occurrences across the calendar. This is a good review article as we prepare for entering the severe weather season in April.

MPR listener question:

I would like to know the outlook for spring and summer flooding. With all we are going through with the COVID-19 pandemic, spring floods would be overwhelming.

Answer:

The threat for spring snowmelt flooding has been greatly diminished by the weather pattern of the past 30 days or so. However, flow volume on many Minnesota rivers and streams remains higher than normal, and soil moisture storage is above normal as well. So, this leaves little buffering capacity to withstand large doses of precipitation this spring. As a consequence, there is still a risk of flooding in many areas if the weather pattern were to suddenly turn very wet for a prolonged period. I do not see that characteristic in the outlook models, but we know how much those can change over time. Note that with an expected rainfall this weekend of over 1 inch in southwestern Minnesota, the National Weather Service has issued a Flood Watch for the Redwood and Cottonwood Rivers.

Twin Cities Almanac for March 27th

The average MSP high temperature for this date is 47 degrees F (plus or minus 12 degrees F standard deviation), while the average low is 29 degrees F (plus or minus 10 degrees F standard deviation).

MSP Local Records for March 27th:

MSP records for this date include: highest daily maximum temperature of 75 degrees F in 1946; lowest daily maximum temperature of 24 degree F in 1965; lowest daily minimum temperature of 5 degrees F in 1921; highest daily minimum temperature of 57 degrees F in 1910; record precipitation of 1.52 inches in 1998. Record snowfall is 5.6 inches in 1965.

Average dew point for March 27th is 25°F; the maximum dew point on this date is 58°F in 1989; and the minimum dew point on this date is -1°F in 2015.

All-time state records for March 27th:

The state record high temperature for this date is 88 degrees F at Winona Dam (Winona County) in 2007. The state record low temperature for this date is -29 degrees F at Red Lake Falls (Red Lake County) in 1955. The state record precipitation for this date is 2.70 inches at Two Harbors (Lake County) in 1975. Record snowfall for this date is 15.0 inches at Virginia (St Louis County) also in 1975.

Past Weather Features:

A slow-moving winter storm brought a mixture of rain, sleet, and snow to many parts of Minnesota over March 26-28, 1940. Many areas of the state recorded 4-8 inches of snowfall, and others set rainfall records with over 2 inches.

By far the warmest March 27th was in 1946 when most climate stations reported highs of 70° or higher. Several locations in the northwest reached 80 degrees F under sunny skies and southerly winds.

Very cold, mid-winter type air mass prevailed across Minnesota on March 27, 1996 bringing subzero temperature readings to most parts of the state. Temperatures fell into the minus 20s F in northwestern parts of the state, and the daytime high temperature only reached 6°F at Wadena.

Outlook:

Rain likely on Saturday, even lingering into early Sunday in some parts of the state. Snow will likely occur in northeastern counties. This system will also bring high winds on Saturday night and early Sunday to parts of the state. Generally warmer for much of next week, with some chance for showers (rain/snow) from late Monday through Wednesday.