The seasonal forecast for above-, below- and near-normal precipitation from the IRI.
The default map shows globally the seasonal precipitation forecast tercile probability. The historical climatology used is 1982-2010 up to the forecast issued in August 2021, and is 1991-2020 from the forecast issued in September 2021. The forecast shown is the latest forecast made (e.g. Dec 2017) for the next season to come (e.g. Jan-Mar 2018). Four different seasons are forecasted and it is also possible to consult forecasts made previously. The forecasts are directly computed from the extended logistic regression model as tercile probabilities.
Contact help@iri.columbia.edu with any technical questions or problems with this Map Room.