NOAA’s Climate Prediction Center produces long-range forecasts for several time periods, including 6-10 days, 8-14 days, 3-4 weeks, and for one to three months at a time going out to as much as a year ahead. Most of these forecasts provide shading to indicate where the probabilities are tipped towards warmer or colder than normal (or wetter or drier, for precipitation maps). But there a lot of confusion about how to interpret these maps. Here is a good discussion by Michelle L’Heureux of NOAA on how to interpret the maps correctly and what they really tell us. You can read it at Weather Nation at http://www.weathernationtv.com/news/understanding-long-range-forecasting-fast-slow/.