When are the forecasts updated? The update schedule for discussion forecasts is: 14 day forecast is issued every Sunday, and is comprehensively updated on Wednesday or Thursday. 45 day forecast is issued during the last week of each month. Seasonal forecasts are issued during the last week of February, May, August and November. Other forecasts for up to 16 days ahead are updated at least twice each day. The 16 to 28 day icon forecasts are updated daily.