This will be short version of this idea, I will post something with more detail next week (CPC issues a new forecast on Thursday) and I want to look at more information. Still what I know now is worth sharing.
The last forecast from CPC (Feb 16th) suggests a warm summer is slightly higher odds than does a near normal or cool summer but the odds are not great, 35% for warm, 33% for near normal and 32% for colder than normal.
However, if we look at all years when there was a La Nina during the winter (there was this winter) when the winter in Southwest Michigan was warmer than normal, like it was this past winter, we see from the charts below the spring it typically warmer than normal with near normal precipitation.
As for the summer we see the warmer than normal trend continues and precipitation remains near normal south of I-96 but it’s wet north of I-96
Since southwest Michigan had a warm winter, let’s look at what happens when the winter is warm, not caring about the state of ENSO.
Now here is something that may change that story! So far, most of southern Lower Michigan has not had a daily the temperature above 60F. The extended ensembles of both the GFS and ECMWF, while not ruling out one or two days with highs that warm, odds are very low at this point. Neither model means show highs that warm, it is only 1 or 2 out of 50 of the ECMWF that are forecasting highs that warm by the end of March. So below is a joint study by Gary Rizzo and myself on what happens at both Grand Rapids and Detriot.
So, this will be fun to watch how this plays out! We already know that if at Grand Rapids the daily high reaches 90F in May there will be a much higher than normal number of 90F days but it now seems we have a filter for below normal numbers of highs in the 90s.
Once again next week I will put info out on our coming summer, but I through it’d be fun to post this this week.
themarinocast 