I have been reading a lot of articles on global warming this year and on what we consider ‘normal’. Climate normals are three-decade averages of climatological variables including temperature and precipitation.
Scientists traditionally define a Climate Normal as an average over a recent 30-year period. The most recent installment covers the period from 1981 to 2010. Why 30 years? Close to a century ago, the International Meteorological Organization—now known as the World Meteorological Organization—instructed member nations to calculate Climate Normals using 30-year periods, beginning with 1901–1930. Also, a general rule in statistics says that you need at least 30 numbers to get a reliable estimate of their mean or average. So, our scientists have traditionally defined Normals as averages over 30 years simply because that is the accepted convention—not because a 30-year average is the only logical or “right” way to define a Climate Normal.
Of course there are a lot of other variables which can swing the climatology for any given year into chaos, such as multiple members of the population buying snow tires at any given point during the year, the flap of a butterflies wings in Brazil or a herd of cattle suddenly farting in Montana or the worse, buying a new snow thrower before the beginning of winter. This is chaos theory with the butterfly effect mixed in.
It is my belief that though the above may be true figuring in chaos theory, climate records only go back a little over 100 years. The average of weather conditions as obtained from observations for a historical 30-year time interval defines typical conditions for a given area. Note that according to the rules of the World Meteorological Organization (WMO), 30-year reference periods are updated at the start of each decade. Granted some of mans influence on climate does bias the data over these periods, such as the amounts of crops grown or cattle raised, and the heat and pollution from large cities we also have to figure in the possibility of volcanic eruptions, wild fires, etc to muck up the equations. While climatology may be cyclic the weather systems around the world are constantly changing and trying to pinpoint what may happen for any given period past 5 days may as well be left to the odds makers in Vegas. Just my opinion….
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I set up a new page on the site from the snow and ice archives which go back to 1997 to current. Above is the comparison between last year and this year to date.
We have a frost advisory for tonight – temps will drop into the mid 30s in SW Michigan. Due to the gaseous effects of pigs and cows our temps may warm into the 60s by the end of the week. 😆
34* degrees out at thee YARDofBRICKS NE of GR as of 1am for sure our first frosty morning ahead …INDY
Nope. Temps bottomed out about 3 or 4 a.m., above freezing, and have been going back up since with the clouds and Southerly breeze. 41 degrees at 7 a.m and no frost.
https://w1.weather.gov/data/obhistory/KGRR.html
It is 39 here already. We picked some of our tomatoes today. We have a lot to ripen yet.
The overnight low here at my house was 37 however the official low at GRR was 42. Yesterday the H/L at Grand Rapids was 50/44. At this time the mean for October at Grand Rapids is 55.9° this is a departure of +1.8. For today the average H/L is 61/42. The record high is 83 set in 1975 and the record low is 27 set in 1939. Last year the H/L was 60/38 and that was the last time Grand Rapids seen a high of 60 or better until March 28th 2019 when the high reached 61.
Slim
Some very good points today MV. My go to site for past weather history is still down it claims to be temporary but we shall see. While there are some other sites that have some of the information they are much less user friendly and contain much less information. My point in bring that up is that while the norm is a 30 year average with the way the site I went to you could input 10, 15, 20, or even a 100 year average. And yes it changes.
Slim
And we must not forget about the rain we are having this Fall amazing amounts shuuu! And onto Wednesday and next Monday more rain coming ..We be in a wet pattern pretty much since last Spring I’m thinking this will favorite our area for snowstorms soon storm track loves west Michigan…INDY ..