To better understand how quickly the seasonal forecast is changing , new forecasts (actually an entire ensemble) are computed every day. We average all forecasts computed within a ten-day period, giving three periods of different forecast age for the last 30 days. The most current period (0-10 days) thus includes todays forecast and the forecasts from the previous 10 days. This most recent forecast period is used to draw the maps for the next 3 months in the lower panels. If you see that forecasts of different age are very different, and even contradict each other, then there is very little hope of forecasting the season at the moment.