With the closure of Liddell power station we have crossed the line into uncharted territory.
Now it actually matters whether the wind blows continuously, or at last between sunset and sunrise.
it does not, although continental wind droughts have only been studied since about 2010 when Paul Miskelly and others started to look at the information from the windmills which are the most useful instruments for detecting them.
The outstanding contributor has been blogging under the name of Tony from Oz since 2018 and his thousands of records on all forms of generation must represent one of the most remarkable single-handed and unfunded research projects of all time.
The BOM might have issued wind drought alerts but their system which was installed in the 1990s collected wind velocity measurements hourly and reported the data as averages for weeks, months and the year. The longest wind droughts max out around three days they only reduced the score for the week without actually revealing periods when there was effectively no useful wind.
The big question is how the meteorologists managed to avoid seeing and warning about the consequences of the European Dunkelfauts that last for weeks. They only got an entry in Wikipedia in 2021! Mariners and millers on land must have experienced them for centuries. Interest has been aroused since Germany and Britain are now embarked on serious deindustrialization due to the Dunkelfauts plus the closure of coal and nuclear (in Germany.) There were clear signs of impending disaster at least a year before the Ukraine invasion.
So the plans for replacing coal with wind and solar need to be re-jigged to take account of these now well-recognized wind droughts and lulls.