Extreme Weather: When Worlds Collide

Real data — temperature, for instance — are almost always the combination of signal and noise, which we could also refer to as trend and fluctuation. Fluctuations are ubiquitous, they happen all the time. Sometimes they go up, sometimes down, sometimes a little and sometimes a lot, but the one thing they don’t do is stop.

Hot down under, and up over

Australia started this new year with the worst heat wave they have ever experienced. It is notable not just for its high temperatures, but for its extent — both geographic and temporal. This heat wave affected nearly the entire country, pushing the continent-wide temperature record to a new high of 40.33°C (104.6°F) — and that’s the average for the entire nation. It has also endured longer than previous extremes. As scientists from Australia’s Bureau of Meteorology (BoM) have stated publicly

It is not that common for the Australian-average temperature to exceed 39°C for even two days in a row. A run of three days above 39°C has occurred on only three occasions, and a run of four days just once, in 1972.

The current heat wave has seen a sequence of Australian temperatures above 39°C of seven days, and above 38°C of 11 days straight.