I know it is only early September but every year there is always speculation on what the coming winter will be like. It always makes we wonder how some people think they can tell what a 90 day period of weather will be like 3 to 6 months in advance (unless you are taking about a location where the weather is very stable) but for us living about half way between the north pole and the equator, will that is a different story. Now for the upcoming winter seasons there are some hints that we could have a condition call La Nina and there are many who think that a El Nino brings a warm dry winter and a La Nina brings a cold and snowy winter well this week I will look at past known La Nina years and see how that winter season ended up. According to Stormfax where they have a list of El Nino and La Nina years going back to 1900. While the list on https://ggweather.com/enso/oni.htm starts at 1950.
I have broke down the La Nana history into two parts. From 1900 to 1950 and 1951 to 2020. For each La Nana winter I have listed the total snow fall for that winter and then the average mean temperature for that winter season. Note all reading are for Grand Rapids La Nana winters 1900 to 1950. The Stormfax listed La Nana winters start with 1903/04 that winter Grand Rapids reported 77.8” of snow fall and the mean that winter was a cold 18.2°. 1906/07 snowfall 30.1” mean winter temperature 24.7° 1908/09 34.4” mean temp 27.8° 1916/17 snow fall 52.2 mean temp 21.8° 1920/21 snow fall 35.6 mean temp 30.9° 1924/25 snow 40.7” temp 24.7. 1928/29 snow fall 55.4” mean temp 23.7. During the warm years of the 1930’s 1931/32 snow fall 41.1” mean temp 33.9. 1938/39 snow fall 65.7 mean temp 28.7. 1942/43 snow fall 64.1 temp 22.9. Recap of the 1900 to 1950 La Nina winters. According to Stormfax there were 10 winters with La Nina winters. The mean temperature of all winters between 1900 to 1950 was 25.6 and the average snow fall was 52.8” during the La Nina winters the mean was 25.7° the mean ranged from a cold winter in 1903/04(18.2) to a very mild winter in 1931(30.9). The average snow fall was 50.1” and ranged from 77.8” in 1903/04 to just 30.1” in 1906/07. Note that total snow fall was less for all winters in that time so the way it was measured might not have been the same as today.
For the la Nina winters from 1951 to 2020. During this time there is information as to how strong the La Nina was so now there is the added item of if it was a weak, moderate, or strong La Nina. The first La Nina winter it this period was in 1954/55 that was weak La Nina the mean temperature that winter was 25.9° and there was 68.8” of snow fall. The next La Nina winter was 1964/65 that was a weak one and the mean temperature was 24.1 and there was 101.4” of snow fall. The 1970/71 event was a moderate one and that winter the mean was 22.7 and there was 101.0” of snow fall. The 1973/74 was the first strong event and the mean temperature that winter was 24.3 and there was 64.4” of snow fall. The next event in 1975/76 also was strong and that winter the mean was 25.7 and there was 69.2” of snow fall. The 1988/89 was the last in the string of strong La Nina’s and that winter the mean was 25.9 and there was 62.2” of snow fall. The 1995/96 event was moderate and that winter the mean was 23.5 and there was 98.4” of snow fall. The 1998/99 event was strong and that winter the mean was 28.6 and 76.7” of snow fell. The 2007/08 event was strong and that winter the mean was 26.0 and Grand Rapids reported 107.0” of snow fall. The 2010/11 event was strong and that winter the mean was 25.2 and there was 74.0” of snow fall. The 2011/12 event was reported as moderate and that winter the mean was a very warm 32.2 and just 51.1” of snow fell. The 2016/17 and the 2017/18 events were reported as weak. In 2016/17 the mean temp was a mild 30.4 and the snow fall was just 60.1” and in the last La Nina the mean was 26.2 and 77.7” of snow fell.
In the last 70 years there were a reported 14 La Nina events and the mean temperature of the 14 events was 24.3 the mean total snow fall was 76.2” There was a range in temperature from 22.7 to 32.2 and a range of snow fall from 51.2 to 107.0. The mean of all of the years from 1950 to 2020 for the winter season is 26.4 and for snow fall it is 75.8” So yes on average there is a chance of a La Nina winter to be colder than average and maybe a little more snow fall. But there is no guarantee.