Soggy weather leading up to Christmas Eve
A mild and soggy weather pattern for the last few shopping days before Christmas Eve & Day. Some much colder air could move in around Christmas and we will be watching for any precipitation to still be around by then.
FOGGY START AGAIN TUESDAY, THEN MUCH WETTER THROUGH WEDNESDAY
Dense fog could again be a problem across the Tennessee Valley through the morning commute. Expect some travel delays during the morning.
The rest of Tuesday looks partly to mostly cloudy with afternoon temperatures in he 50s. A mild day for mid/late December, but also becoming wetter during the afternoon. Some scattered showers could move in from the west during the afternoon and evening. So, the afternoon commute could be wet in some locations. The coverage of rain increases late Tuesday Night and into Wednesday. Some heavy downpours are possible through the Wednesday Morning rush hour. Rain by the afternoon should become more scattered and begin moving out through Wednesday Evening.
Rainfall potential shows the possibility of a 1"-2" average locally, but a few isolated local spots could be near 3". The bulk of this heavy rain Wednesday Morning.
BRIEFLY DRIER TO BEGIN WINTER
The first day of Winter is on Thursday. It should be a mild start to the new season as afternoon highs could reach the upper 50s. Some fog early, but otherwise a mix of sun and clouds. A nice, but brief dry period before more rain moves in,
NEXT ROUND OF RAIN STARTS FRIDAY
Rain could move back in during the day Friday. Forecast models differ a bit on timing of arrival with the GFS Model sooner, but the European Model later. For now, I will forecast the arrival of the rain later in the day Friday and into Friday Night. This round of rain could even include some thunderstorms as a cold front approaches on Saturday. Rainfall amounts could again be heavy in spots. A quick glance at forecast model projections shows anywhere between 2" (GFS) to over 3" (European) for late Friday through Saturday.
CHRISTMAS EVE/DAY OUTLOOK
Just a week away, but still some uncertainty with the upcoming weather pattern. It all comes down to when much colder air could return to the Tennessee Valley.
As of this posting, the latest forecast model runs show much colder air moving in during the day Christmas. The early Monday GFS model had what we call some "overrunning" precipitation interacting with the arrival of cold air. That scenario showed a possible round of wintry weather (snow, sleet). But, again, that is a model. As another example, the European Model for Christmas has the cold air arriving much later in the day. Therefore, a wet day with above freezing temperatures, then a possible change to snow showers late day as the cold air moves in. Another model scenario by the GFS Monday Afternoon forecast had all of the precipitation far out of the Tennessee Valley before much colder air arrives on Christmas Day.
In other words, a lot of scenarios here without much consistency from run to run. And, we have two big weather systems in front of this. So, I would expect the uncertainty and model flip-flop to continue into the start of the weekend until these 2 rain makers move through.
It does appear that a much colder week can be expected next week. The question as mentioned above is how soon the cold air arrives.
As always, you can depend on the StormTrack 9 Team for updates!