Seasonal Temperature Outlook

The NOAA CPC seasonal temperature outlooks forecast the likelihood (percent chance) of the 1-month or 3-month temperatures occurring in the above-average, near-average, and below-average categories, based on the historic (1981-2010) distribution of temperatures.  These three categories, or terciles, are bounded so that an equal fraction (33.3%) of the historic temperatures is in each category.

The numeric values on the maps do not refer to actual temperature values, but to the probability, in percent, that temperatures will be in one of these three terciles, if that probability is different than 33.3%. The shading indicates areas in which the odds are tilted towards warmer-than-average (A, orange shading) or cooler-than-average (B, blue shading) condition. The numeric values indicate the probability that temperatures will be in the above-average or below-average tercile--with a corresponding decrease in the opposite category. The near-average category remains at 33.3% likelihood, unless the forecast probability is very high for the above- or below-average tercile, or a near-average forecast is more likely than the other two categories. 

Thus, areas with dark orange shading indicate a 40.0–50.0% chance of below-average, a 33.3% chance of near-average, and a 16.7–26.6% chance of above-average temperatures. Light orange shading displays a 33.3–39.9% chance of below-average, a 33.3% chance of near-average, and a 26.7–33.3% chance of above-average temperatures, and so on. Equal Chances (EC) represents equal odds or a 33.3% probability for each tercile, indicative of areas where forecast signals are weak or conflicting. “N” indicates an increased chance of near-average conditions, but this is not forecast very often. 

The skill of the temperature outlooks largely comes from the status of ENSO, and recent warming trends. 

Additional CPC forecast maps, at lead times longer than 1.5 months.