May Climate Update

May Climate Update:

Minnesota farmers took advantage of the recent preponderance of dry days and rapidly advanced their planting progress. Over two-thirds of the state corn crop and over a third of the state soybean crops have been planted. Soil moisture recharge has been very good this spring around most of the state, with over 80 percent of the state reporting adequate to surplus stored soil moisture conditions (according to USDA Crop Condition reports). Rains this week of over half an inch were beneficial to parts of western and southern Minnesota fields. Over an inch and a half of rain fell in portions of Clay, Nobles, and Houston Counties. Dew points also hit seasonal high points this week reaching the mid to upper 50s F prior to the rains on May 15th. With near seasonal or above normal temperatures prevailing, crops are readily germinating and emerging in only a few days.

Mother’s Day (last Sunday brought the warmest temperatures since April 13th when it was 90°F at Granite Falls and in the 80s F at many other places. Many areas of the state reported afternoon highs in the 80s F for Mother’s Day, with 88°F at MSP. Temperatures for the balance of the month are expected to run a bit cooler than normal, but no expected frosts are in the forecasts. Also, rainfall may be more frequent for the balance of the month. This will perhaps produce above normal rainfall for the second month in a row.

Weekly Weather Potpourri:

Earlier this week I had the privilege of handing out the 10th Annual Climate Adaptation Leadership Awards from the Minnesota Climate Adaptation Partnership Program. It was an absolute honor for me to recognize these outstanding leaders for their efforts to make Minnesotans more resilient to climate change. In the five award categories the winters were:

Climate Justice Leadership-the Community Action Center of Northfield, MN
Collaborative Climate Adaptation-Truterra and the MN Dept of Agriculture Climate Smart Farms Program
Individual Climate Adaptation Leadership- Syd Bauer of Morris, MN
Organizational Climate Adaptation Leadershp-Frogtown Green in St Paul
Creative Climate Communications Leadership-Ben Weaver

More details about the accomplishments of these award winters can be found at the MCAP web site.

This week’s AGU-EOS Bulletin features an article out a pilot study in New York that used a set of low-cost flood sensors to collect data on flood events at a local scale. This detailed data proved to be of great value to various stakeholders, including city agencies, community members, and researchers. Perhaps these sensors will be deployed in other urban environments that are prone to periodic flash flooding.

The BBC reported this week on a comprehensive tree ring study that showed last summer was the warmest in 2000 years for the Northern Hemisphere, following a upward trend evident in recent decades. This new study suggests this means that the world may have actually warmed around a quarter of a degree more than typically reported.

MPR listener question:

We have heard you talk in the past about comfortable weather conditions and how infrequent they are. From the standpoint of average temperature and humidity when are the most comfortable times of the year in Minnesota?

Answer:

Not sure that I can objectively answer this question. But if we accept that 70°F is generally comfortable for outside activity, and that 50° is generally a comfortable nighttime low, the long-term averages for the Twin Cities suggest that May 15-19 are ideal, and that September 22-26 are equally ideal as average maximum and minimum temperatures correspond to these values. I might further add that average dew points are in the mid-40s F as well which adds to the comfort. Of course, in Minnesota there is such wide variation around the daily averages, that the actual average value hardly ever occurs. Such is the case for today (May 17) where the average maximum temperature is 70°F and the average minimum temperature is 50°F. In the past 150 years of Twin Cities climate records, these values have only been measure on May 17th just 7 times, so less than 5 percent of the time has average actually occurred.

Twin Cities Almanac for May 17th:

The average MSP high temperature for this date is 70 degrees F (plus or minus 10 degrees F standard deviation), while the average low is 50 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for May 17th:

MSP records for this date: highest daily maximum temperature of 93 degrees F in 1987; lowest daily maximum temperature of 46 degrees F in 1890; lowest daily minimum temperature of 31 degrees F in 1915; highest daily minimum temperature of 69 degrees F in 1911, and record precipitation of 2.47 inches in 2020. There was a trace of snow in 1890.

Average dew point for May 17th is 45°F; the maximum dew point on this date is 69°F in 1996; and the minimum dew point on this date is 17 degrees F in 2009.

All-time state records for May 17th:

The state record high temperature for this date is 100 degrees F at New Ulm (Brown

County) in 1934. The state record low temperature for this date is 14 degrees F at St Vincent (Kittson County) in 1888. The state record precipitation for this date is 4.43 inches at Blue Earth (Faribault County) in 2000. The state snowfall record is 12.0 inches at Saint Cloud (Stearns County) in 1890.

Past Weather:

Measurable snowfalls occurred on May 17 of 1890 across many central and northern Minnesota communities as temperatures hovered in the 30s and 40s F. Traces of snow were recorded in the Twin Cities. Thirty-six hours later, it was sunny and temperatures rebounded to the 60s F.

The hottest May 17 was in 1934 when over 40 climate stations reported maximum temperatures of 90°F or greater. In Chaska, after a morning low of 45°F the afternoon high warmed to 96°F.

Very cold temperatures prevailed over central and northern Minnesota on May 17 of 1983. Many areas reported morning low temperatures in the 20s F. Afternoon high temperatures were only in the 40s F along the north shore of Lake Superior.

Outlook:

Warm, sunny, and breezy in the south over the weekend, with increasing clouds on Sunday and a chance for showers into Monday. Up north there will be scattered showers and thunderstorms over the weekend with breezy conditions. A good chance for showers on Monday and Tuesday, with perhaps some thunderstorms, then consistent, but smaller chances for showers the remainder of next week, with temperatures trending a bit cooler than normal from the prevalent cloudiness.