Preliminary Climate Summary for March 2019

Preliminary Climate Summary for March 2019:

Following the trend of February, March was colder and wetter than normal across most of the state. Most climate stations will report a mean March temperature that ranges from 3 to 6 degrees F cooler than normal. No daily record high maximum or minimum temperatures were reported within the Minnesota climate station network. However, during the cold first week of the month there were 74 low minimum daily temperature records tied or broken, and 108 daily low maximum temperature records tied or broken. Extreme temperatures for the month were minus35°F at Cotton (St Louis County) on the 8th to 67°F at Windom (Cottonwood County) and Winnebago (Faribault County) on the 27th.

Most observers in the state reported above normal precipitation for the month, with the wettest areas in west-central and southwestern counties where totals of 2.5 to 3.0 inches were common. Within the climate station network 103 daily precipitation records were tied or set. Madison (Lac Qui Parle County) reported the most with 3.26 inches. Many stations reported over 1.5 inches of precipitation on the 14th. For monthly snowfall, over 100 climate stations reported a monthly total of 10 inches or more, with 15 to 18 inches in western portions of the state. Within the climate station network, 37 daily snowfall records were tied or broken during the month. Amazingly, 170 climate stations reported new daily snow depth records, including 40 inches at Milan (Chippewa County) on March 10th.

There was plenty of wind during the month as well, with 10 or more days seeing gusts of 30 mph or higher.

Thankfully the second half of March was drier than normal, with many freeze-thaw cycles which helped to meter out the snowmelt runoff, and mitigate a serious flood threat on many watersheds.

The Annual Larson-Allmaras Endowment Lecture on April 5th

For those interested in environmental and agricultural topics, a highlight of the month of April is the Annual Larson-Allmaras Endowment Lecture at the University of Minnesota-St Paul Campus. This program concentrates on the topics of soil and water, with emphasis on research and management practices. This year it is scheduled for 2pm on April 5th. It is also special because it is marking the retirement of Professor Satish Gupta, who has concluded a 46 year career. The title of his presentation is "Reflections on 46 years of research: From packing sand grains to the Minnesota River. You can find out more at the Department of Soil, Water, and Climate web site.

Weekly Weather Potpourri:

For those not acquainted with the Cloud Appreciation Society, they are out with their new newsletter and cloud of month photo. They also have some articles about clouds depicted in works of art, as well as descriptions of some cloud watching tours they are conducting.

Tom Di Liberto of NOAA is out with an interesting article about how well the NOAA-Climate Prediction Center performed with their 2018-2019 winter Outlook for the nation. With respect to Minnesota, they got it wrong with both temperature and precipitation for the December through February period. The CPC outlook for winter favored warmer than normal conditions and normal to drier than normal with respect to precipitation. The actual measured conditions were colder than normal or near normal for the average of December-February, and very much wetter than normal with respect to precipitation.

Another analysis released this week by NOAA presents the expansion of the pollen season due to climate change. In our Minnesota backyards the ragweed pollen season measured over the past several decades has lengthened by 16 to 20 days.

In this week’s AGU-EOS newsletter there is a highlighted report about how difficult it is to accurately track and count tornadoes across the Canadian landscape. Scientists there are trying to come up with methods to more accurately count tornadoes, including an examination of signatures in the Canadian Lightning Detection Network.

In the Southern Indian Ocean this week Cyclone Joaninha was churning with winds of 115 mph and sea wave heights of 35-40 feet. It was weakening and remaining out to sea and not a threat to any islands there.

MPR listener question:

I am a 60 year gardener in the Twin Cities (West St Paul) and I have always abided by the statistic that our average last temperature reading of 32 degrees F or colder in the spring is about May 9th. But my neighbors tell me that it has changed and it is earlier now. Can you provide an opinion on this?

Answer:

Indeed, your neighbors are correct. Over the past 20 years, the last reading of 32 degrees F in the Twin Cities has been around April 20th. The latest it has occurred in the past 20 years is May 9th in 2010, but it has also occurred as early as April 8th in 2006.

Twin Cities Almanac for March 29th:

The average MSP high temperature for this date is 48 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 29th:

MSP records for this date include: highest daily maximum temperature of 83 degrees F in 1986; lowest daily maximum temperature of 13 degree F in 1969; lowest daily minimum temperature of -5 degrees F in 1969; highest daily minimum temperature of 57 degrees F in 1910; record precipitation of 0.79 inches in 1998. Record snowfall is 11.0 inches also in 1924. Believe it or not there was still 27 inches on the ground on this date in 1965.

Believe it or not on this date in 1843 the high temperature at Fort Snelling was 11°F and the low was -7°F for a mean daily temperature of 2°F, 37 degrees F colder than the modern normal.

Average dew point for March 29th is 25°F; the maximum dew point on this date is 56°F in 1910; and the minimum dew point on this date is -13°F in 1969.

All-time state records for March 29th:

The state record high temperature for this date is 83 degrees F at MSP and at Gaylord (Sibley County) in 1986. The state record low temperature for this date is -23 degrees F at Itasca State Park (Clearwater County) in 1921. The state record precipitation for this date is 2.88 inches at Lake City (Wabasha County) in 1998. Record snowfall for this date is 17.5 inches at Maple Plain (Hennepin County) in 1924.

Past Weather Features:

The morning of March 29, 1922 brought bitter cold temperatures to Minnesota, with subzero readings across the far north. Even the daytime highs could not make it out of the 20s F that day in many places.

March 28-29, 1924 brought a blizzard with heavy snow to many parts of the state. Many observers reported 10-20 inches from this storm, with a record-setting 22 inches at Canby (Yellow Medicine County). By far the warmest March 29th in state history was in 1986. Most areas of the state saw afternoon high temperatures reach the 70s F, while 17 climate stations reported highs of 80 degrees F or greater.

The greatest March tornado outbreak in Minnesota history took place on March 29, 1998, resulting in two fatalities. As many as 14 tornadoes touched down across southern Minnesota, including 13 spawned by a supercell thunderstorm that tracked from the SW corner of the state to just a few miles from the Wisconsin border. One of the more powerful tornadoes, an EF-4, was on the ground for 67 miles and had a maximum width of 1.25 miles. Comfrey and St Peter were hit very hard, and it took years to recover from the damages. The MN State Climatology Office provides a more detailed accounting of these storms.

Outlook:

A mostly sunny weekend is coming up, with temperatures a few degrees F cooler than normal. It will continue to be mostly dry with a slight chance of a shower late Sunday in some places. A warm up to above normal temperatures will begin on Monday, but increasing cloudiness by Wednesday will bring a chance for rain or wet snow showers to many areas.