I knew it would come as soon as I saw the weather chart on Friday. A large anticyclone centred over Europe brought a flow of air from the Sahara over Portugal, and the mild, balmy breezes we have enjoyed of late continued northwards towards Ireland.
It seemed only a matter of time before a nonplussed populace would find their cars and other belongings covered in a fine, red dust, and so it happened in my neighbourhood late on Saturday.
Of course, it might very well have never come at all. For the dust to fall directly on our little island, more meteorological coincidences are needed than merely favourable winds.
Sandstorms in the Sahara are the first prerequisite; the reddish-brown particles of dust raised by these storms are carried high into the atmosphere by the powerful convective currents common in those latitudes.
Once aloft, the lighter grains remain suspended and are carried along at high levels, typically two to three miles high.
For Ireland to be affected, the most favourable weather pattern is an anticyclone over western Europe, providing easterly winds over north Africa to bring the airborne dust first westwards out over the Atlantic, and then north-eastwards to reach Ireland two or three days later.
Finally comes the last link in the chain: the airborne particles are usually too light to fall to the ground of their own accord, but if rain originates in the atmosphere at a higher level than the dust, many of the suspended particles are washed to earth, carried downwards with the raindrops. And so it happened over the weekend.
In olden times, because of their reddish tinge, these scarlet visitations were thought of as "showers of blood". One such in Lombardy in 1117, for example, caused such consternation among the locals that a meeting, not of meteorologists, but of bishops was held afterwards in Milan to consider what might be their origin.
And Homer relates how a "shower of blood" fell upon the heroes of ancient Greece as a harbinger of death.
But now we know, of course, that there is nothing supernatural about them - or is that so? Perhaps, with Ash Wednesday on the way, the weekend's dust was a meteorological precursor of the Lenten enjoinment "Memento homo, quia pulvis es", a reminder, as Edward Fitzgerald put it, in his Rubaiyyat, to:
?????make the most of what we yet may spend,
Before we too into the Dust descend;
Dust into Dust, and under Dust, to lie,
Sans Wine, sans Song, sans Singer, and - sans End!