Category: climate

It is looking like December 2023 will end up being in the top 5 warmest Decembers on record across Michigan. This will likely be true not only in Michigan but across most of the northern CONUS.

So far, as of the 16th, December is averaging 6 to 8 degrees above normal across Southern Lower Michigan. Flint is warmest with +7.8, while while Grand Rapids is the least with +5.5. Most other climate sites are between 6 and 7 degrees warmer than normal through the 16th in Michigan. Over northern Michigan Alpena has the least positive departure with +4.1 while Gaylord is +5.9 and Traverse City is +5.1. We are expecting two cold days (Monday and Tuesday) but the rest of December is expected to well above normal. Thus, December 2023 is likely to be in the top 5 warmest on record over most of Lower Michigan.

I thought it would be fun to look at our Fall of 2023 climate and now close what happened came to what would typically happen during an El Niño Fall.

In our string of nationally much warmer than normal seasons, the fall of 2023 was 124th out of 129 falls for warmer than normal. This puts this fall warmer than 96% of all falls since 1895! No area of the CONUS had a below normal temperatures (bottom 1/3 coldest) this fall.

Here is a quick look at November.

For the most part, November was not was warm, relative to normal as October was, in fact the eastern half of the CONUS was cooler than normal in November, as were parts of the Pacific Northwest. It was an extremely dry month over most of the CONUS, ranking 111th dries out of 128 years (91%). Only the Gulf Coast and Florida were wetter than normal. Snowfall was mostly below normal but a snow storm brought heavy snow from Kansas to near Chicago around the 25th resulted in up to a foot of snow in that area, bringing them above normal snowfall for November.

It looks like our warmer than normal temperatures will persist over the western CONUS but over the eastern half of the CONUS, largely based on the MJO, with some ensemble model support colder and snowier weather will follow the last 2 weeks of December. Over the Southeast it will just be cool and wet.

Here is my winter forecast for 2023-2024 for both the CONUS and for Southwest Michigan.

The short story is I am expecting a not so typical moderate to strong El Nino Winter this year. This is due to record warm sea surface temperatures in combination with an easterly wind over the tropical oceans, near 200 mb. This these two features acting together create an unusual amount of blocking in our Northern Hemisphere jet stream. This will mean periods of extremely cold weather and periods of unusually warm weather for a good part of the central and eastern United States lower 48 states. Even so, for Southwest Michigan and actually for all of Michigan I expect snowfall to be below normal but we will get a decent amount of snow nonetheless.

Here is a more detailed both CONUS and for Michigan, October Climate Summary.

By waiting until the 8th, I can get the maps from NCEI (National Center for Environmental Information). I have added graphs from xmACIS for the daily temperature and precipitation plus I have the monthly climate summary from Grand Rapids and Gaylord.

The weather over the next two weeks will feature some warm and dry weather as well as cold and wet weather. Mostly it will be warm dry over the western CONUS into next week. Over the eastern CONUS it will mostly be cooler and wet. A significant warm up may follow over the eastern CONUS by the middle of next week.

Typical of fall we will see a warm up, then it will rain and get cooler, only to warm up by early next week. Then it will get wet and cooler once again.

Expect the wet and cool weather over Northern Midwest into New England, including the Great Lakes, to persist into early next week. An impressively large blocking upper-level high, over central Canada will keep the storm track over the northern CONUS into early next week. It will also allow a subtropical system to track along the Gulf Coast over the next few days.