---
name: Jet Stream
slug: jet-stream
type: atmospheric feature
status: running
version: 4.6.1
released: "~23000000 BCE"
maintainer: Hadley Cell Consortium / Coriolis Force Working Group
dependencies:
  - temperature-gradient
  - earth-rotation
  - troposphere
  - solar-heating
license: Public Domain (nobody asked)
tags:
  - weather
  - atmosphere
  - fluid-dynamics
  - invisible-infrastructure
  - wind
---

Jet Stream

What it actually is

A fast, narrow current of air looping the planet at altitude, doing enormous work that almost nobody thanks it for.

How it works

The atmosphere is not uniform. Warm air masses and cold air masses press against each other at the poles, and the Coriolis effect spins that pressure gradient into a ribbon of high-velocity wind. This ribbon sits roughly 9 to 16 kilometers above sea level, moves at 100 to 400 km/h, and meanders in great sinuous waves called Rossby waves.

There are four main jet streams. Two polar, two subtropical. The polar jet streams get most of the press because they are the ones that rearrange your winter without warning.

The core mechanic:

Sun heats the equator unevenly
Temperature gradient forms between poles and tropics
Air attempts to equalize
Earth's rotation deflects it sideways
Narrow fast current forms at the tropopause
Your flight from London to New York takes 90 extra minutes

Features

Tailwind service: Reduces transatlantic eastbound flight time by 1 to 3 hours. Mostly unacknowledged.
Weather steering: Guides storms like a slow conveyor belt. High pressure, low pressure, all riding the wave.
Polar vortex containment: When functioning correctly, keeps the Arctic cold air locked in the north. When not, see Known Bugs.
Self-modifying path: Naturally amplifies its own meanders over time. This is called amplification and it is not a metaphor.

Known bugs

Bug ID	Description	Severity	Status
JS-041	Polar vortex disruption releases Arctic air equatorward	Critical	Intermittent
JS-119	Blocking patterns stall weather systems for weeks	High	Recurring
JS-203	Jet stream weakening linked to Arctic amplification	High	Worsening
JS-307	Aviation turbulence spikes near core	Medium	Increasing

"It just sat there. A dome of high pressure for three weeks. Nothing moved." — a farmer, every decade, more frequently now

Configuration

# jet_stream.config
type: polar
hemisphere: northern
current_position: anomalously_wavy
wave_amplitude: elevated
speed_kph: 180
climate_mode: transitional
turbulence_output: moderate_to_severe

Note: Do not attempt to configure manually. Several nations have tried. None succeeded.

Edge cases

When the jet stream splits into two branches, meteorologists politely call it a "split flow." What it means for your weather is less polite.
Over the Pacific Ocean, the jet stream can accelerate past 400 km/h, briefly outrunning some aircraft in absolute terms.
During solar minimum, the jet stream tends to sit lower and wander more. Correlation with cold winters observed. Causation debated loudly at conferences.

Changelog

v4.6.1: Increased wave amplitude. Blocking events more frequent. No patch available.
v4.5.0: Gradual poleward migration of subtropical jet begins.
v3.0.0: Last glacial maximum repositions all streams significantly southward.
v1.0.0: Initial deployment following planet achieving rotational stability.

drafting spec…