Heading into the final week of December and the year 2021, we are expecting to see near-record warmth and active weather! We will end the weekend off with mild temperatures and breaks in clouds. By the afternoon hours, the Tennessee Valley will enjoy some sunshine and temperatures nearing 70 degrees.
A strong southwesterly wind flow will lead to an increase in warm air and deep tropical moisture. This tropical air will set the stage for active weather midweek and near-record high temperatures. Temperatures Monday, Tuesday, and Wednesday are forecasted to reach the low 70s. With the high-temperature Tuesday forecasted to reach 73 degrees, it will be one degree off from tieing the warmest on the record set in 1907. Wednesday looks to be another potential record-setting day with the warmest on the record being set in 2019.
By the second half of the week, slightly cooler air will be ushered in behind a frontal passage. Although we will see this cooler air being filtered, temperatures will still remain above average for the remainder of the seven-day forecast period. High temperatures late this week and into the first half of the weekend will be in the mid to upper 60s!
Active weather returns
Though scattered rain showers are possible on Tuesday the better chance for the active weather will arrive Wednesday. Deep tropical moisture, instability, and lift will support the potential for thunderstorm development. A strong cold front passage will be the reason for the return of this active weather. Coverage in rain showers becomes more widespread as the cold front approaches the region Wednesday.
One thing that will be monitored closely is the possibility of localized heavy rainfall. Any showers or storms that develop will be able to tap into a very saturated environment leading to the threat of heavy rainfall. For the month of December, here in Huntsville, we are seeing a rain deficit of nearly 2 inches. Any rainfall we see will be beneficial, but if we see training storms it could lead to isolated flooding.
All the necessary ingredients will come together to support the development of thunderstorms. The Storm Prediction Center has already noted the potential for isolated strong to severe storms to develop late Wednesday into Wednesday night. It is still too early to tell where exactly these storms could develop, but at this moment, any location within this yellow area could see a strong storm. The main threats during this time period will be damaging winds and heavy rainfall. Stick with the Weather Authority for the latest updates!