Seasonal climate summary for the southern hemisphere (summer 2019–20): a summer of extremes
Naomi Benger
A * and Bernard Chapman B *
+ Author Affiliations
- Author Affiliations
A Bureau of Meteorology, Science and Innovation Group, Level 4, 431 King William Street, Adelaide, SA 5000, Australia.
B Bureau of Meteorology, Business Solutions Group, GPO Box 413, Brisbane, Qld 4001, Australia.
* Correspondence to: naomi.benger@bom.gov.au, bernard.chapman@bom.gov.au
Handling Editor: Blair Trewin
Journal of Southern Hemisphere Earth Systems Science 73(2) 83-101 https://doi.org/10.1071/ES22029
Submitted: 20 September 2022 Accepted: 23 March 2023 Published: 11 May 2023
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the Bureau of Meteorology. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)
Abstract
This is a summary of the southern hemisphere atmospheric circulation patterns and meteorological indices for summer 2019–20; an account of seasonal rainfall and temperature for the Australian region is also provided. The antecedent climate conditions and climatic drivers for summer 2019–20 resulted in unprecedented extremes for Australia, with many heat and fire weather extremes. The austral summer of 2019–20 was staged to be hot and dry, with climate drivers supporting higher than average temperatures and lower than average rainfall. These conditions contributed to the highest recorded monthly accumulated national Forest Fire Danger Index. As the dominant climate influence for December receded during the season, dynamic (weather) processes dominated for changeable conditions – particularly in the mid-latitudes. Both January and February were among the 10 hottest on record, although several mid-latitude sites experienced unusually cool days. Across the rest of the hemisphere, conditions were also extreme, with notable drought conditions persisting from spring over large parts of South America. Temperature anomalies for land and ocean areas of the southern hemisphere were respectively the third and second highest on record.
Keywords: 2019, 2020, Black summer of fire, climate summary, Forest Fire Danger Index, Indian Ocean Dipole, Pacific, seasonal summary, severe Tropical Cyclone Damien, southern hemisphere, summer, summer of extremes.
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