2021 winter seasonal outlook

A survey of 12 international models condensed in the below charts (top both and bottom LHS) shows the outlook for winter rain sitting in the mid-tercile range for the BOM and other EU multi-system, whereas the IRI North American ensemble is more bullish on higher precipitation. Temperature predictions (bottom RHS) show a similar theme with no signal for cooler or warmer conditions. This is not unusual given most indicators are quite close to neutral. The longer-range charts do favour a wet Indian Ocean Dipole developing along with a wet Modoki phase, influencing our spring. SST predictions also favour warm waters through the Arafura Sea and Ningaloo Reef which could well be flowing through model outputs for the mid-latitudes.

See bottom chart for the IRIs refreshed early spring outlook!

Order of Figures clockwise from top left: ACCESS-S tercile forecast, CS3 multi-model tercile (ECMWF, UK, France, Italy, US, Japan), 5x North American models combined on the bottom showing rainfall (LHS) and temperature (RHS). IRIs extended outlook at the bottom.

IRIs winter precip and temp forecasts

IRI’s early spring forecast refreshed this week.