When I talk about impacts of El Nino in the Southeast, I often mention that the jet stream moves south to a position that is usually located across southern AL and GA and northern FL. The jet stream pushes along the winter storm systems that bring rain (and occasionally snow) to the region. Cloud cover associated with these low pressure centers also keeps daytime temperatures cooler, so climatological El Nino winters are often cooler than average because of cooler daytime high temperatures and not necessarily because we have more cold outbreaks. Of course, this is starting to change with global warming, since the increase in winter temperatures due to greenhouse gases may overwhelm the cooling from El Nino, which makes forecasting based on statistics of past events less reliable. NOAA’s ENSO blog last week had a good discussion of how El Nino moves the jet stream that you might find helpful. You can read it at https://www.climate.gov/news-features/blogs/what-we-talk-about-when-we-talk-about-jet-stream-and-el-nino.
