ST. LOUIS, Mo. – Fall is a great season, if it lasts that long. All summer, we look forward to some heat and humidity relief. But sometimes fall doesn’t act like fall at all. Let’s dive in.
There are several ways to define the season we call Autumn. As meteorologists, we define it as the months of September, October and November.
On September first, you will hear us say “welcome to meteorological Fall.” Then there is astronomical Fall: starting with the Autumnal Equinox. Then there is “real fall” or the time it really starts to feel like fall.
We’ve had a taste of some cooler temps, but mostly it has been a warm September — at least warmer than you think Fall should be. That is a trend that will continue through the end of the month: above normal temps, and generally dry weather. It is a pattern that is the remnant of late August.
For the next couple of weeks, look for average temperatures to above normal, making September warmer than normal — just last September 2021. Precipitation last year was around the normal 3” — this year we will be just below that normal mark.
There is one key atmospheric ingredient that has been generally missing so far this season: the tropics. It has been very quiet and the hurricane season has been slow to develop. I think October is the month that will change. With a more active tropics, our weather will get active too. Let’s look for some quick swings to cool or cold within the first couple weeks of October. That quick drop in temps may also come with some rain. Let’s watch for some severe weather with that kind of transition.
The second half of the month will turn warm and that too could bring some rain. Yes rain, not snow. We’ve had snow on Halloween before, but this year it will be on the warmer side of anything spooky.
Last October temps averaged out a bit above normal thanks to a very warm start. This year, even with some potentially big temperature dips, we will average out near normal — or a little above.
October 2021 had several storms rolling through, but precipitation by the end of the month averaged below normal. This year we will watch the pattern transitions for rain, with a monthly total that will be a little below normal.
Sometimes when you see where you’re going, it makes you nervous about the journey. We are getting our first looks at the winter pattern and what December, January, and February look like. More on that in our Winter Outlook that will air in November. But to get to that point, we will really need to start evolving in November.
I think the month will actually start warmer than normal. But cold air will be looming, lurking, and ready to pounce. I think by the end of the month, some of that cold will be arriving. You can never truthfully rule out snow in November. Last year marked the 3rd straight year we’ve had snow in early November. This year we may wait a little, but snow is a higher possibility with the chill arriving late in the month.
Last November was weird. We had very little rain, amazingly dry for weeks. This year it will not be drier than that, but could average out below normal.
In 2021, we had above normal temps for the first half of the month, but it averaged out to about normal. This year, let’s look for a warm start, then a drop toward the end.