We’ve made it to October! That means we have a new month to look at weather stats and records for here in the Tennessee Valley. Keep in mind the way we do this… we use climate reporting stats from Muscle Shoals, Alabama at the Northwest Alabama Regional Airport. That is the most centrally located NWS climate reporting site with long-term records in our area. Its stats also give a good idea of the general climatology of southern middle Tennessee also, not just northwest Alabama.
The average daytime high for the month comes in at 75.7 degrees, and the average monthly low is 51.5 degrees. However, that ranges a lot from one end of the month to the other. As we begin the month, the average high is 79 degrees, but it is down to 69 as we head out of October into the start of November… and likewise, the morning low averages at 58 degrees to start the month but is down to 45 as we reach Halloween and then the first of November. Those are just averages though. The high temperature at the Muscle Shoals site has been as hot as 100 degrees in both October 2018 and 2019, and the overnight low has been as cold as 23 degrees in 1917. In fact, while the average morning low by the end of the month is down around 45 degrees, we usually do see our first frost of the season in the final week or two of the month.
Along with September, October is the driest time of the year in the Tennessee Valley, statistically speaking. We average about 3.47″ of precipitation for the month normally. However, in drier years, we can go the entire month without any rain at all. Other years, we can have landfalling tropical systems or heavy thunderstorms bring flooding rains to the area. In addition, while there hasn’t officially been any measurable accumulating snowfall in the month of October at the Muscle Shoals reporting site, we have been known to occasionally have sleet showers and snow flurries as early in the cool season as the last week of October!
Severe weather and tornado “season” in our local area here in the Tennessee Valley runs from November through the end of May. However, those are fuzzy lines instead of hard ones. Just as our spring tornado season bled over into June this year, sometimes the fall activity can start in October some years. October isn’t known for a ton of tornado activity here, historically speaking, but they do sometimes happen. This marks the transition time of year when whatever severe storm and tornado threat there may be shifts from being related to tropical systems in the summer to being associated with cold fronts and jet stream disturbances that come down with the fall southward migration of the upper-level jet stream. Because of this increase in wind shear intensity, while tornadoes are not frequent in the month here, when they do happen, they can occasionally be strong (EF2 or greater intensity). This serves as a reminder that we will be heading into our area’s severe weather season soon, and it is time to go through your safety plan, make sure you have a shelter plan hammered out, make sure everyone has helmets, etc.
October is also often a somewhat active month for tropical systems in the Atlantic basin, especially the first half of the month. Our attention over time shifts away from the waves that roll off the coast of Africa and more toward systems that develop in the Caribbean and Gulf. These often lift north and northeastward ahead of approaching cold fronts and upper-level troughs. The Florida peninsula is often a hotspot for landfalling tropical storms and sometimes hurricanes as we head through October; however, we only have to think back to storms like Michael in 2018 and Opal in 1995 to remember that big league hurricanes can occasionally make landfall on the northern Gulf Coast as well in October. Having said that, there are many years that we see little to no tropical landfalling systems on the Gulf Coast during the month of October. So far, the Gulf has been quiet this year. Only time will tell whether or not that trend holds. The Atlantic hurricane season continues through the end of November.
