The Climate Prediction Center (CPC) is the National Weather Service center that predicts and monitors climate on time scales from about a week out to seasons ahead. Its outlooks tell you whether temperature and precipitation are favored to run above, near or below normal, rather than what will happen on a given day.
Where it sits and what it issues
CPC is part of the National Centers for Environmental Prediction (NCEP) and is based at the NOAA Center for Weather and Climate Prediction in Maryland. NOAA describes its work as predicting and describing climate variations on time scales from weeks to years.
Its products include the 6 to 10 day and 8 to 14 day outlooks, Week 3 to 4 outlooks, one-month and three-month outlooks, the 8 to 14 day U.S. Hazards Outlook, drought information and the ENSO Diagnostic Discussion, which tracks the El Nino-Southern Oscillation (ENSO). The 6 to 10 day outlooks are issued daily between 3 and 4 p.m. Eastern Time.
How to read the maps
Each outlook compares the forecast to three equal categories taken from a 30-year record. The coldest or driest third defines below normal, the warmest or wettest third defines above normal, and the middle third is near normal, so each starts with a 33.33 percent chance.
Shading shows how far the favored category's probability rises above 33.33 percent. Areas where the forecast tools favor neither side are labeled EC, for equal chances.
What it does not tell you
Darker shading means more confidence, not a bigger anomaly. A 60 percent chance of above normal temperatures says nothing about how far above normal readings will run.
Equal chances is not a forecast of normal weather. It means the tools do not lean either way, so above, near and below normal each keep a 33.33 percent chance.
Fitting it with weather forecasts
CPC handles the longer range, while the Weather Prediction Center and Storm Prediction Center handle specific rain, winter and severe weather events in the days ahead. A pattern favoring wetness in week 2 can hint at an active period, but individual storms still need short-range forecasts.