News
03/23/2022, 8:13 pm EDT

Australia Season 1-3 Ahead Outlook: Cold risk late autumn/early winter; finally, a drier climate East next spring.

Executive Summary: The Climate Impact Company season 1-3 ahead forecast for Australia valid for the remainder of autumn through spring 2022 is update. The outlook is based on a slowly fading La Nina through mid-year and a developing negative phase Indian Ocean Dipole by mid-winter. Highlights include significant cool risk late autumn and early winter followed by a drier climate emerging on the East Coast for next spring. Climate discussion: During the past 2 years the Australian climate has averaged wetter than normal which is in direct opposition to the preceding 2 dry years. So far in 2022, the wettest anomalies are concentrated on Central/South-central and Coastal Southeast Australia while dry zones have emerged in Northeast Queensland and Southwest Australia (Fig. 1).  However, the wet regime was more widespread in 2021 and 2020 although less extreme (Fig. 2-3). Triggering the wet climate pattern for most of Australia during the past 2 years is a steady La Nina climate based on multivariate ENSO index (Fig. 4).   In 2022, the La Nina pattern is forecast to weaken (Fig. 5). However, the La Nina climate as identified by MEI may be slower to fade. Consequently, the wet bias La Nina brings to Australia is likely to continue through at least mid-year. Additionally, there is risk of a negative Indian Ocean Dipole (-IOD) pattern developing by early quarter 3 of 2022 (Fig. 6). The -IOD pattern also has a wet bias for Australia climate. Based on these two climate indicators, the general wetter than normal climate pattern of 2020, 2021 and Q1 of 2022 is likely to continue and any major drought risk is negated. Fig. 1-4: Australia anomalous rainfall for 2022, 2021 and 2020 and the cause of the general wet pattern – a La Nina regime based on multivariate ENSO index. Fig. 5-6: Australia Bureau of Meteorology forecasts neutral ENSO for southern hemisphere winter and also potential for a weak negative phase IOD pattern. The 2022 Australian climate forecasts are generated using a constructed analog based primarily on a weakening La Nina and possible -IOD development. April 2022: The mid-autumn outlook remains warmer-than-normal across Southeast Australia due to the presence of semi-permanent high-pressure. Western Australia cool risk increases. The tendency for wet weather is projected along much of the East Coast which is also similar to the previous outlook.   Fig. 7-8: The Climate Impact Company constructed analog temperature and precipitation anomaly climate forecasts for April 2022.  May 2022: Forecast confidence increases regarding significant chill during late autumn. The risk is strongest mid-continent. The forecast trend is cooler for an already chilly forecast. The chilly pattern implies precipitation is likely typically dry for most of the continent. Fig. 9-10: The Climate Impact Company constructed analog temperature and precipitation anomaly climate forecasts for May 2022.  JUN/JUL/AUG 2022: Meteorological winter starts with a cold risk mainly for central to northwest quadrant. The seasonal forecast is warmer than normal for the eastern half of the continent. Implications are winter starts with the strongest cold risk but ends quite mild especially in the East. Despite a possible lingering La Nina climate (despite the actual oceanic La Nina ending) combined with evolving -IOD, the forecast is not unusually wet. Wet risk is highlighted in parts of eastern continent and the forecast trend is wetter. The fading La Nina but developing -IOD pattern suggest that any new evolution of important drought is unlikely. Fig. 11-12: The Climate Impact Company constructed analog temperature and precipitation anomaly climate forecasts for JUN/JUL/AUG 2022.  SEP/OCT/NOV 2022: Signs of a changing climate pattern? For the first time in 2+ years, the East is forecast drier than normal. The temperature outlook features both patchy warm/cool zones. Fig. 13-14: The preliminary Climate Impact Company constructed analog temperature and precipitation anomaly climate forecasts for SEP/OCT/NOV 2022.