News
03/16/2023, 8:24 pm EDT

Australia Month 1-3 Ahead Outlook: Out of La Nina so drier but cool climate for Q2/2023.

Executive Summary: The Climate Impact Company month 1-3 ahead climate forecast for Australia valid for Q2/2023 is updated. The outlook is based on a shift out of a La Nina climate to neutral ENSO and then into an El Nino climate by June. Also considered are marine heat waves especially intense in the New Zealand waters. The outlook is generally cooler than normal heading into the winter season. The shift away from La Nina and toward the positive phase of the Indian Ocean dipole midyear suggests risk of unusual wet weather episodes common the past 3 years has ended. The cool climate forecasts also suggest above normal risk of cold events during June across the eastern half of Australia. Climate: The ENSO prediction barrier is present into May. A transition out of La Nina climate to a neutral ENSO regime is forecast through Q2 of 2023. Dynamic models bring El Nino fast by JUN/JUL. The El Nino forecast is agreed-upon by many models but diagnostics are required to foreshadow that dramatic change in ENSO before wholeheartedly calling that outlook reliable. The month 1-3 ahead forecast is based on a transitional ENSO out of La Nina and toward El Nino for APR/MAY and into El Nino in JUN. Also of note are marine heat waves (MHW) either side of Australia. MHW can amplify subtropical ridge patterns. The month 1-3 outlook suggests subtropical ridge areas are likely either side of Australia with a persistent cool trough across the continent. April 2023: Mid-autumn brings a semi-permanent upper trough to central and eastern continent. As a result, the prevailing climate is cooler than normal. The upper trough causes patchy wet areas including the central continent and New South Wales to Victoria, and possibly parts of the West Coast. Fig. 1-2: The Climate Impact Company constructed analog temperature and precipitation anomaly climate forecasts for April 2023. May 2023: Presence of the upper trough remains based on the CIC-CA forecast. Dynamic models are not as cool. The precipitation outlook is seasonably dry especially on the East Coast. Fig. 3-4: The Climate Impact Company constructed analog temperature and precipitation anomaly climate forecasts for May 2023. June 2023: By June, El Nino onset is expected. Additionally, a positive phase of the Indian Ocean dipole (+IOD) may emerge. The combination of each climate pattern favors developing dryness in Australia although June is normally quite dry. The temperature outlook favors cooler than normal climate across central and eastern continent while southwestern sections are warm. The risk of unseasonably chilly air masses is above normal for June mainly across the eastern half of Australia. Fig. 5-6: The Climate Impact Company constructed analog temperature and precipitation anomaly climate forecasts for June 2023.