As we approach the winter months, many national news outlets will be talking about the La Nina pattern which is setting up on a global scale. But what does this mean in general and for our weather?
La Nina is part of a global pattern called the El Nino / Southern Oscillation (ENSO). This is a pattern of above and below normal water temperatures in the central and east-central Pacific Ocean. The La Nina phase is the cooler than normal temperatures over this region of the Pacific. These cool temperatures affect patterns in our part of the United States.
In a typical La Nina year, cooler than normal temperatures often prevail over the northern tier of the country while warmer than normal temperatures are common from the Ohio Valley through the Mid Atlantic and southern United States.
In terms of precipitation, with a strong moisture flow off the Pacific northwest and a jet stream predominately over the Ohio River area, wetter than normal conditions prevail over the Pacific northwest and the lower Great Lakes. Dry conditions are usually preferred for the southern tier of the country.
So for us at home, this would put us on average in a wetter than normal pattern for a majority of the winter while we would be between an area of colder temperatures to our north and warmer weather to the south.
Keep in mind this is NOT an actual winter weather prediction, rather an informative post which explains the predominant characteristics for a La Nina pattern. This video contains maps which display this information.