01
The mesocyclone
The turning mass above everything else, three times wider than the column is tall. It is what gives the funnel its rotation, and it is where the light comes from when a bolt fires inside it.
A Fabric mod for Minecraft 1.21.11
A supercell turns somewhere over the map, its base lowers, and a funnel comes out of it and reaches the ground. What it passes over is torn out, thrown and destroyed.
What it changes
The sky decides on its own, and between the moment you hear it and the moment it is on you there are eighty seconds.
Nothing is summoned. A vanilla thunderstorm breaks, the mod watches whether it holds long enough to organise, and if it does a rotation settles over a point on the map. The funnel comes out of that, spends fifteen seconds or so reaching down, touches the ground and starts working. It travels at eight blocks a second and the roar carries six hundred and forty, which leaves time to run if you leave at once.
The Enhanced Fujita scale
00/05
Hover to compare, click to pin.
The rating is stored nowhere: it is read off the gust, the way a real survey reads it off the damage. The six floors are the real ones, 29, 38, 50, 61, 75 and 90 metres per second, and the width follows the speed because large tornadoes really are the strong ones. The scale in detail
Five pieces
A tornado is not an object.
It is a stack, and every floor of it has its own size and its own duration. The mod draws all five, from the cloud deck down to the dust hanging at ground level.
02
The wall cloud
The local lowering of the base, right over the spot where something is about to come out. It forms before the funnel and stays after it, which makes it the one marker left when rain hides the column.
03
The funnel
The visible condensation, narrow at the ground and flared above. No particles in there: it is a volume marched through by a fragment program, with its striations, its hollow centre and a wall that thickens as the wind climbs.
04
The debris ring
What the column has already torn out and has not yet dropped. It spreads well past the funnel, it takes the colour of the ground it crossed, and the heavy pieces are real entities that really do hit you.
05
The rope
The last fifth of its life, where it draws out, leans over by up to 70 % of its height and finishes as a thread. It still hurts the whole time, which is exactly the trap the real ones set.
The warning
YOU HEAR IT
BEFORE YOU SEE IT
The roar starts before anything is visible on the horizon, and it rises as the distance falls. Three messages arrive in chat, one per step, never the same one twice. The last one warns of nothing: it reports.
640 blocksthe roar starts
The skystalls and turns green
The walllowers, the funnel drops
Contactwhatever is under it goes
The wiki
Thirteen pages, none of them hiding where its number came from
Every threshold quoted here is the one written in the code, with the name of the setting that moves it. A page that gives a number gives the formula that produces it too.
Report, suggest, vote
A bug gets told once, in the same place as all the others.
Known problems live on the repository's Issues page, with their state and what sets them off. Look there before writing: half the time the answer is already up, and the rest of the time your report is what the existing thread was missing.