This seasonal forecasting system consists of probabilistic temperature seasonal forecasts based on the full estimate of the probability distribution -- February-December 2017
Probabilistic seasonal forecasts from multi-model ensembles through the use of statistical recalibration, based on the historical performance of those models, provide reliable information to a wide range of climate risk and decision making communities, as well as the forecast community. The flexibility of the full probability distributions allows to deliver interactive maps and point-wise distributions that become relevant to user-determined needs.
The default map shows globally the seasonal temperature forecast probability (colors between 0 and 1) of exceeding the 50th percentile of the distribution from historical 1982-2010 climatology. The forecast shown is the latest forecast made (e.g. Mar 2017) for the next season to come (e.g. Apr-Jun 2017). 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 probabilities of exceedance (or non-exceedance) of every 5th percentile of the climatological distribution. The specific quantile (in steps of 5%) can then be selected. The user can also specify the historical quantitative value (here seasonal average temperature in ˚C) for probability of exceedance or non-exceedance.
Clicking on a point on the map will show the local probability of non-/exceedance of the forecast (green) together with the climatological distribution (black).
Colors Scales
Color scales are colors indicating that the distribution of the forecast tends towards drier (shades of brown) or wetter (shades of blue) conditions than normal (moccasin).
Older Forecasts
Discontinued older forecasts made prior to February 2007 can be found in the last tabbed entries of this section. Note that the methodology to obtain the full distribution of the forecasts was different at the time.
Forecast Probabilities: 1˚ spatial resolution for 17 percentiles from 10th to 90th percentiles every 5 percentile available here.
Historical temperature derived from GHCN+CAMS 2 m temperature (land only) available here monthly at 1˚ spatial resolution.
Contact help@iri.columbia.edu with any technical questions or problems with this Map Room.