Humor me for a second. Let’s say that there was a planet that was experiencing a covert civil war. By this I mean that most of the fighting was being done cloak and dagger, by various factions within intelligence agencies and the corporate bureaucracies. Of course the occasional open skirmish between paramilitaries erupts from time to time but for the most part there is a gentleman’s agreement to keep things as quiet as possible and not alarm the public.
Now assume for a moment that one of the two major factions had control of the planetary weather control system. On one hand this is a powerful weapon but they need to be very careful not to push their luck too far. After all they are trying to conquer the planet, not destroy it and all major factions have access to WMDs. There is also the problem that if they keep messing with the weather too much the general population is going to notice something’s up and the last thing any of the elites want is the average citizen pulling his grandfather’s rifle out of the closet and getting involved.
Therefore use of the planetary weather control system is limited not so much by capability but political factors and the need to avoid escalating the conflict into open warfare.
So now that we have the basic parameters let’s ask the real question. What advantages would causing a continent-wide cold snap around the time of the major winter holidays confer?
Interestingly is not the northern cities that suffer. As a population that is prepared for -35C winters at least know what to do in -45C weather even if they are not particularly fans of it. Plus even the poorest citizen of a northern city is going to own a proper winter coat.
The southern cities also are barely effected. While snow in unexpected places can cause panic and a few traffic accidents, there will be no real damage to infrastructure.
It is the temperate cities in the middle of the continent that are most effected. A population that does not normally experience harsh winters is unlikely to own heavy winter clothing and infrastructure may fail if suddenly subjects to unexpected stresses.
Now what if the major political centers on this hypothetical continent were moderate temperate cities near a coastline. Well not only would we have cold weather in a city where the general population is unprepared for severe winter weather but there would also be much heavier snowfall than usual.
And this of course is during the major winter holidays, the time of year where air travel is highest. A northern airport is going to have a great of snow removal capacity, a temperate city airport is not. Therefore causing a cold snap is going to have the effect of shutting down or restricting air travel near the politically important coastal cities. Why do this?
Perhaps it’s a measure to make moving key personnel very difficult for the opposing faction.