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Summer heat arrives late in Australia. More heat in Argentina ahead.

Fig. 1-2: Australia December/January 2022-23 observed temperature anomalies.

Fig. 3-4: 12Z GFS Australia temperature anomaly forecast for the next 14 days.

Discussion: Due primarily to the wet weather suppressing heat risk related to a La Nina climate in December/January, the summer of 2022-23 has observed limited excessive heat across the continent (Fig. 1-2). However, the convection phase of Madden Julian oscillation (MJO) to the north of Australia is forecast to shift eastward the next 1-2 weeks inducing a west to southwest wind across much of the continent and cause extreme heat risk beginning across Western Australia in the near-term (Fig. 3) and expanding across the southern tier of Australia in the 8-14-day period (Fig. 4). Maximum temperatures exceed 110F/43C across mainly central and northern Western Australia into early next week with 110-115F/43-46C shifting across the southern third of Australia in the 8-14-day outlook.

In South America, the 12Z GFS indicates anomalous heat roars across Argentina over the next 5 days (Fig. 5). Featured are maximum temperatures of 110F/43C over Northeast Argentina. A brief break from the excessive heat in the 6-10-day period with patchy heavy rain indicated in Paraguay to East Argentina (Fig. 6). The excessive heat returns to Argentina in the 11-15-day period (Fig. 7).

Fig. 5-7: 12Z GFS South America temperature anomaly forecast for the next 5 days, percent of normal rainfall for days 6-10, and temperature anomaly outlook for days 11-15.