Forgive the quick succession of posts, we’ve had very hot weather here and I’m finding writing much easier than game dev! Hopefully soon I’ll have caught up to the current state of development with these devlogs 
Generating Wind Patterns
There are three layers of air in Patterns of the Wind at low, mid and high altitudes, with each layer having its own wind pattern. This means that the direction of the wind acting on the balloon varies by both position on the map (the player's x,y coordinates in the room) and by the balloon's height. The prevailing wind at the top layer always blows to the east, which is defined as up on the map and into the screen from the side-on view. This allows the player to always at least easily progress on to the next map and, eventually, to circumnavigate the globe. The mid and low layers however have varying wind patterns that change on every visit to a map. These are the layers the player has to navigate so that they can land at the towns to replenish their supplies (needed to keep flying) and increase their fame (which is effectively their score).
Completely randomising the wind direction at every location would be chaotic and almost impossible to navigate, not to mention not very fun! Instead there are 14 standard predefined wind patterns that are chosen from, designed to appear both realistic by recreating familiar wind features such as cyclones, and to be comfortable to read and plot courses with across the size of each map. At any point the player can pause the game by opening up the full map view, and from there they can cycle through the wind charts showing the patterns at the low and mid layers. The idea is that manually cycling through the layers like this helps to further emulate the action of consulting paper charts.
Here are some examples of different wind patterns being displayed on charts for both low and mid layers:
When moving to the next map and choosing the new wind patterns only fully navigable pairings of patterns are allowed i.e. it must be possible to plot a course from any position on the map to any other position on the map. This precludes several combinations, for example if both the low and mid layers only had crosswinds blowing north/south it would be impossible to move west. There are also some patterns that can only appear in the mid layer and not the low layer as I wanted the scale of the patterns to reduce with lowering height. I didn't want for instance a room-size single cell cyclone to be below two cells that are half-room size as that isn't as intuitive when thinking of the lower layer as more localised weather. With those restrictions there are 64 total combinations of wind patterns and the low and mid layers, compared to a possible 196 if allowing any and all combinations. That's still plenty!
Navigating these wind patterns is at the core of Patterns of the Wind, hence the name of the game. Hopefully it strikes the right balance of complexity and navigability for players!
Of course the player can't navigate through the layers of wind without being able to alter the height of the balloon. In the next post I'll talk about how the player actually goes about flying the balloon using crank controls.