November has given us inclement weather across much of the United States. We can use our climate links to visualize how different this weather is from the climate normals I discussed in a previous post. I make those comparisons from Missoula, MT, my home, but you can explore the sites and examine how this year is playing out climatically for you hometown.
Temperature is the big story, with major polar/arctic higher pressure systems defending across the central U.S. Here is a plot of temperature for Missoula for November showing a background of normal and record temps.
You can see that until November 9th, everything was “normal”, maximum and minimum temperatures within or close to the boundaries of the normal band (light green band). In fact there were several days in the “warmer than normal” category. But then everything changed!. On November 10th, a new weather system set up, bringing in the arctic air mass and its associated cold temperatures. For eight days maximum temperatures did not reach or barely reached the normal minimum temperatures. The last two days have warmed some, but with maximum temperatures still well below the normal maximum temperatures. Now, November 21st, the weather has shifted (see Prof. Cliff Mass’ blog for today for a great description of this change in weather) and warmer weather is arriving for the weekend, along with more precipitation.
November precipitation has also been interesting (as those living in Buffalo, NY know!). Here is the same NOAA Weather Service plot for Missoula.
Not many days of precipitation, but what we had was near record levels. Not that the precipitation came as the warmer weather of early November was replaced by the cold arctic air of middle November. This was due to warm, wet air from the Pacific hitting the arctic blast on November 9 and 10. Let’s look at how all this compared to temperature and precipitation throughout the year. Again, you can get all these plots for you area by going to the NOAA website listed in the precipitation plot or reading the “Normal vs. Normals” post.
Here is the summary for the year, to put our November weather in the annual climate context. Quite something!
First, check out temperature. November really stands out for the year. A blob of low temperatures well below the normal band, but it was not alone. Back in February and early March we had the same sort of arctic blast. But, look at how the precipitation responded to that event versus now.Until mid-February, Missoula precipitation was below normal. Then in omen storm associated with two Feb-Mar weather events, precipitation rose well above normal. Through the Spring precipitation continued to be above normal until Fall, when we entered a dry spell. That was ended by the mid-November storm system that moved through. So, we are now above normal precipitation. That Feb-Mar event also set us for an above normal snow year, that looks to be entrenched for the rest of the year. In fact the NOAA forecast is for substantial snow in Montana’s mountains over the next 72 hours. So, most of November will be subnormal for temperature and supernormal for precipitation. The climate point to all of this? Weather controls these short-term deviations from climate which is a function of “averaging” all this variability.
Have a great Thanksgiving, what ever weather you receive.