Weather update: Sunday – December 31, 2023

New Year's Eve: Mostly sunny and warm. Highs: Low to mid 50s. Wind: South 5-10 mph.

Overnight: Mostly cloudy. cold. Lows: High 20s to lower 30s. Winds: southwesterly 5-10 knots per hour… northerly 5-10 knots per hour.

New Year's Day: Decreasing cloudiness and cold. Highs: Low to mid 40s. Wind: North 10-15 mph.

Overnight: Mostly clear. cold. Lows: Mid to upper 20s. Wind: Northerly 5 – 10 knots per hour.

Tuesday: sunny. A little warmer. Highs: 45-50. Wind: Northerly 5 – 10 knots per hour.

Overnight: Increasing clouds. cold. Lows: Low to mid 30s. Wind: calm.

Our New Year's Eve weather will be better than what we saw on Saturday. A drier southwesterly flow will keep skies mostly sunny, and moderate southwesterly winds will provide us with a warmer day. I always say that a ten-degree difference in high temperatures from one day to the next is more than enough to be noticeable, and this is exactly what we will see today. We will definitely see temperatures in the lower and middle 50s will be an improvement over yesterday's weather system. High-level clouds will advance later in the afternoon, as another fast-moving system moves to the southeast from the upper Midwest.

There will be a lack of air lift and moisture with this frontal system, so we won't have any precipitation, but clouds will increase tonight, with cold air sliding southeast of the News12 viewing area. The facade will be right outside our door as we bid farewell to 2023 and welcome 2024, around midnight. So there may be a slight increase in northwesterly winds behind the front around 11pm to 2am EDT. Temperatures may drop a little faster after midnight until dawn, on New Year's Day. At this time, it looks like temperatures will be around 40 degrees under mostly cloudy skies, with north winds around 10 mph as we count down the final minutes of 2023.

A mid-week storm system that appeared to have the ingredients to bring a decent amount of rain later Wednesday into early Thursday morning continues to weaken as it approaches the Tennessee Valley and southern Appalachia region. During the last two months of 2023, we will see a relatively common weather pattern, where our fast river of upper-level winds splits into two, or the two streams develop independently of each other. As temperatures decrease with solar declination and day length across Canadian provinces, the upper polar jet stream strengthens, and the fast flow associated with the Earth's curved surface produces counterclockwise rising low-pressure systems. These areas of low pressure typically have a slightly greater impact across the northern tier of the United States during the early to mid-fall portion. Another rapid river of air tends to develop southward, with a greater impact on the southern parts of the country. In a similar way, these southern layer systems have a more significant influence, in terms of precipitation production, across these lower latitudes, including southern Texas, the Gulf Coast, and the Florida Peninsula.

The problem with this configuration is that the News12 viewing area can be excluded from the stronger, deeper, moisture-laden layers of the atmosphere that form near the induced, lower-level cross-surface jet stream and low-pressure centers. In this separate upper-level jet scenario, moderate to heavy precipitation occurs far enough north and south of our region, so we experience mostly dry frontal passes. Meteorologists define a separate upper-level jet stream pattern as “out of phase.” If the two rivers of fast-moving air actually merged into one dominant upper-level jet stream, this would be defined as a “simultaneous” combination of upper-level winds. This phasing system results in a much stronger lift to the upper level. A system like this, with stronger upper-level dynamics, creates a much stronger lower-level pressure system, which can create greater amounts of precipitation and, if sufficient atmospheric instability is present; Possibility of severe thunderstorms and tornadoes. As we move forward through the end of the first week into the second week of January, medium-range models indicate the possibility of approximately three “simultaneous” storm systems that appear to have enough lift and instability for some heavy rain, and possibly develop moderate to strong thunderstorms. . The heavy rainfall would certainly be appreciated, as the area's aquifers are in desperate need of recharge!

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