Snow Season Outlook for Winter 2021-2022 for Duluth, MN
The 30-year climatology for mean seasonal snowfall for Duluth, MN was recently updated based on the years 1991 to 2020. The new value is 90.2, which is an increase from the previous 86.1 based on the years 1981 to 2010. The National Centers for Environmental Information updates climatological averages every 10 years by dropping the oldest 10 years and adding the most recent 10 years.
Updated Discussion issued April 9, 2022
Winter 2021-2022 has already reached the anticipated snow total of 86 inches as of April 8. EXCELLENT! A good chance exists that the 30-year snow average of 90.2 inches will be reached or exceeded. A strong upper-level jet stream has been aimed into the west coast early this April and extending into the central United States. With the jet stream flowing around a broad upper-level trough, low pressure systems will be taking aim at Minnesota and Wisconsin as they move from southwest to northeast. This time of year those types of storms usually have little trouble soaking up moisture from the Gulf of Mexico. One such storm just dumped a load of rain and soggy snow on April 5 to April 8. Higher elevations of Duluth, including the National Weather Service, got around 8 inches of accumulation. A variety of forecast models show that additional storms will affect the area during the month. The jet stream may flatten a bit but the procession of storms looks likely to continue. With Duluth along the edge of the cold air, expect some of the precipitation to fall as snow.
June 1, 2022: Update to the update - The stormy weather pattern continued through April as expected. The season snow total at the National Weather Service Forecast Office in Duluth was 94.2 inches and exceeded the seasonal average. The office reported 19.2 inches of snowfall for April. April was also generally wet with lots of rain falling. Total liquid equivalent was 4.02 inches compared to a normal of 2.53 inches.
Original discussion issued November 8, 2021
Snow season totals are anticipated to exceed the previous season. Lets try 86 inches for the National Weather Service Office in Duluth and 84 inches at personal location near the ridge crest in Central Duluth. Margin of error is plus or minus 30 inches. Just kidding!
Similar early snow season climate patters exist as compared to last year. La Niña conditions still exist with colder than normal Pacific water near the equator. The Pacific Decadal Oscillation (PDO) is still negative. The cooling of the water off of the west coast of North America associated with the PDO tends to enhance the atmospheric affects of a La Niña. One difference from last year is that the Arctic Oscillation (AO) has been dominantly negative during September and October leading into the snow season. The longer-term condition of the AO, based on the last several years and several decades, is still dominantly positive. The La Niña does not appear to be as strong as last year but is still in the weak to moderate range. The combination of a stronger La Niña and positive AO can sometimes result in the main jet stream staying too far north. Hopefully that won't happen. The snow total for the previous season was only 76.4 inches at the National Weather Service in Duluth. That season also failed to produce any big snowstorms of 10 inches or more. Bummer!
Oceanic Niño Index - Climate Prediction Center of the National Weather Service
Pacific Decadal Oscillation (PDO) - National Centers for Environmental Information
Graph of the Arctic Oscillation Index (3-month running mean) - Climate Prediction Center of the National Weather Service