What a difference a day can make, and for that matter a year. This time last year we had not even had our first freeze yet; that did not happen till Thanksgiving Day. This time yesterday some locations were at 80 degrees and an inspection of the temperature map on the right shows that some locations in extreme SE Ok are still near the 80 degree mark this afternoon. Meanwhile, the rest of us have been holding in the 50s or low 60s.
So, with very warm and humid air not that far away it will not take long for it to surge back northward in advance of the next storm system that will be affecting the state on Wed and Thanksgiving Day. This next storm system will be a potent one with strong southerly winds in advance of it for much of the day Wednesday. Showers and some embedded thunder will likely be spreading northward during the overnight hours tonight, but those are not expected to be severe. As that very warm, humid air just south of us surges back over the state during the day Wednesday, the atmosphere will become conditionally unstable. Very strong dynamics will already be in place and this all adds up to the potential for severe storms late Wednesday and Wednesday night.
How quickly the morning activity moves out and how much, if any, sunshine we receive during the day Wednesday will be one factor in determining how severe the storms will be later in the day. Another factor is the timing of a much stronger cold front. Most of the guidance has this cold front arriving around midnight or shortly thereafter although there is some disagreement with that as some models are much slower. At any rate, showers and storms are likely along and ahead of that front and as mentioned, some of these will pose a risk of becoming severe.
For the most part, the general consensus is to bring the front through with the faster solutions so that the rain will be ending from west to east during the morning of Thanksgiving Day. That is a good thing as temperatures will quickly fall to near freezing that morning and will pretty much stay in the 30s. There are some indications that lingering showers may persist even into the afternoon hours for the more eastern counties but temperature should be above freezing there. However, with gusty northerly winds through Thanksgiving, wind chill values will be generally in the 20s so it will be quite cold.
The coldest temperatures so far this season can then be expected to start Fri with teens and low 20s expected. Fortunately, we will have a quick turnaround with a return to southerly winds and warmer conditions for the weekend.
As always, stay tuned and check back for updates.