It has been bone dry in Kentucky and especially western Kentucky for the past 8 weeks. On top of that, while temperatures have been cooler recently, that are still a few degrees above normal for the most part. All these conditions can partially be explained by the re-emergence of the La Niña in the Pacific Ocean.
La Niña is basically the opposite of El Niño, meaning that instead of warm conditions in a particular part of the equatorial Pacific, the water is cooler than average. And though these aren't strong La Niña conditions, they will affect the winter weather forecast for the United States. 
I have told you before in previous posts that a La Niña would contribute to a milder and drier winter across our region. Phenomena like El Niño or La Niña only provide some clues, not certainty, as to what might occur during an upcoming season.
There are other things at play here than just the La Niña. Arctic sea ice was observed to be at a new all-time low for the month of October. Given that sea ice is running well below normal, this currently favors a strengthened Siberian high, and a weakened polar vortex/negative AO this upcoming winter. In English, this means that despite the presence of a weak La Nina, the polar vortex is expected to split and the part that will affect our region will probably set up near Hudson’s Bay in Canada.
The polar vortex is what affected our winter a couple of years ago with the cold and the deep snowfalls. I look for this to begin sometime around the week of Christmas and continue into the New Year. Right now, much of the really cold air is over Siberia on the other side of the planet. As time goes by, a cross polar flow will develop a
nd help to transfer some of that cold into the Arctic areas of Canada. As the snowpack continues to build in the north, the cold will increase as well. Having said that, a problem in our region is the drought. These dry conditions help to create a warmer type of dome over us.
So, even though we have some colder shots of air coming in, it won’t have any long lasting staying power. There is some thoughts that a strong front and storm system arriving for the coming weekend of the 19th and 20th, will help deliver some rainfall. It won’t be enough to break the drought, but it could help start the break. Sort of like priming the pump. A pattern flip that I and others have been speaking of for several weeks will start as temperatures take a nosedive and continuing into Thanksgiving week. Highs in the 40’s are likely and some parts of Kentucky could see a few flakes of snow. As we get into the first week of December, an unsettled period seems to take hold along with a few shots of colder air. There could be a rain/snow mix around the 3rd or 4th but more rain than anything.
Every few days through the first half of December a series of systems will bring additional chances of rain. If this holds true, the drought should be minimized and open the door for more normal winter type 
weather patterns. While daytime highs are expected to remain above freezing, the lows will drop below freezing more frequently. So this is an uncertain time and difficult to predict.
But it does seem that the chance for an icing event would be more probable during the time from about mid-December until the start of Christmas week. Then, around December 23rd or 24th, there are signs the polar vortex may start affecting our region. By this time, the storm track should lie just to our south and with colder temperatures in place…I think you get the picture. From this point, into January and February if everything continues on target, this is when we can expect a good deal of winter type weather. The only thing that concerns me is the continued threat of icing between visits from the polar vortex in January.
So this is my latest thinking on the upcoming winter. Just remember, nothing is in concrete. But it is at least a thought of what is in the works. Be patient. Winter doesn’t even begin until December 21st and it is coming. Feel free to leave comments and be sure to hit the “Like” button at the bottom of this post.
