5:00 PM CDT | November 3, 2017
November is off to a warm start for Texans. Several record highs were set yesterday ahead of the cold front. Cooler air has settled into the state behind the boundary, but temperatures are still above seasonal norms. Temps will climb this weekend with some parts of the state expected to be around 90*F again. The next cold front will arrive Monday night-Tuesday, dropping temperatures closer to normal. A reinforcing shot of cold air is expected Tuesday night with a disturbance. The weather models differ in the strength of this system, but it should provide enough lift for at least widely scattered showers Tuesday night-Wednesday. Because of the overrunning setup (moisture lifting over and falling through a shallow layer of dry, cool air), forecast temperatures during this time-frame may be too warm for many areas on Wednesday. We will have a better idea on the strength of the disturbance and the coverage of showers in the next few days.
One thing I wanted to briefly discuss is the Arctic Oscillation (AO). Many of you have probably heard of the Arctic Oscillation. In case you are not familiar with it, the Arctic Oscillation is an index representing the state of the atmosphere in the Arctic region. More can be found here: https://climate.ncsu.edu/climate/patterns/NAO.html. For this post, the important thing to know is that positive anomalies favor higher pressure over our part of the globe, usually leading to mild or warm conditions. Negative anomalies favor lower pressure and unsettled, often colder, weather. As you can see, it is in positive territory and has been for a while. Our temperatures have been warmer than normal as well. During the latter part of October, the index dropped to near neutral meaning that it favored neither, and other factors had a bigger role in our weather. We saw a string of colder than normal days, including a round of early season frosts and freezes. The latest model guidance shows the AO falling to neutral or negative territory in 7-10 days.
The weather pattern that is taking shape before our eyes is unique and unlike the one we saw take shape last fall. According to the recurring cycle theory, a unique pattern sets up from early October through mid or late November and repeats in the following months. The same number of features are in play, but they can differ in strength depending on the jet stream, the AO, etc. I still believe the state will see more opportunities for wintry weather than what we experienced over the last two winters. Does it mean that the entire winter will be cold and wet? No, but whereas many Texans did not really have a winter last season, this one looks more promising in my honest opinion.