Weather
A live console of the global atmosphere — circulation, fronts, severe weather, forecasting. Drawn from NOAA, ECMWF, and the storm-watcher tradition of Beaufort, Fitzroy, and the chasers of Tornado Alley.
The Air We Live In
Earth's atmosphere is 78% nitrogen, 21% oxygen, 0.93% argon, 0.04% CO₂. 99% of its mass sits within 32 km of the surface. Five layers, defined by temperature gradient.
- Troposphere 0–12km · weather lives here
- Stratosphere 12–50km · ozone, jets fly here
- Mesosphere 50–85km · meteors burn here
- Thermosphere 85–600km · ISS orbits here, aurorae
- Exosphere 600km+ · merges with space
Three Cells, Six Winds
Earth's rotation and uneven solar heating split the atmosphere into three convection cells per hemisphere — Hadley (equator–30°), Ferrel (30°–60°), Polar (60°–pole). Surface winds: trades (NE/SE), westerlies, polar easterlies. The Coriolis effect deflects right (N) / left (S).
Where Air Masses Meet
A front is the boundary between two air masses of different temperature and humidity. Fronts produce most of mid-latitude weather.
// COLD FRONT
Cold air pushes warm air up steeply. Narrow band of intense rain, thunderstorms. Temperature drops fast.
// WARM FRONT
Warm air rides up over cold. Long, gradual rain over hours. Cirrus → cirrostratus → nimbostratus.
// OCCLUDED
A cold front overtakes a warm front. Triple-point intersections breed severe storms.
Cloud Atlas
Luke Howard's 1803 nomenclature — Latin roots — survives unchanged: cirrus (curl), cumulus (heap), stratus (layer), nimbus (rain).
The Top of the Beaufort Scale
Hurricane Patricia (2015, eastern Pacific) reached 345 km/h sustained — the strongest reliably measured. Tornadoes form in the supercell's mesocyclone, where rotating updrafts (originating in horizontal wind shear) tilt vertical and tighten. Tornado Alley runs from north Texas through Oklahoma, Kansas, Nebraska — uniquely positioned where Gulf moisture meets dry continental air and Rocky Mountain cap.
The Eye
A mature tropical cyclone has three structures: the eyewall (60–80 km/h to 350+ km/h winds, deepest convection), the eye (calm, descending air, 30–60 km diameter), and spiral rainbands extending hundreds of km out.
Hurricane Hunters of the 53rd Weather Reconnaissance Squadron fly Lockheed WC-130J Super Hercules through eyewalls at 3,000m to deploy dropsondes — the data improves track forecasts by ~30%.
Saffir-Simpson scale developed 1971 by engineer Herbert Saffir & meteorologist Robert Simpson.
Active Watch Categories
Numerical Weather Prediction
Lewis Fry Richardson's 1922 dream — computing the weather from physics — became reality on April 5, 1950, when the ENIAC produced the first 24-hr forecast in 24 hours. Today the ECMWF Integrated Forecasting System (Reading, UK) and NOAA GFS are the gold-standard global models.
A modern forecast solves the primitive equations on a 9 km grid worldwide, ingesting ~50 million observations per day from satellites, balloons, ships, aircraft. Forecast skill at day 5 today exceeds day 3 in the 1980s. Ensemble methods (50 perturbed runs) probability-cone hurricane tracks.
"The atmosphere is a chaotic system; this does not prevent us forecasting it — only forecasting it perfectly." — Edward Lorenz, 1963
Tornado Alley
Howard Bluestein, professor at the University of Oklahoma, has chased and probed mesocyclones with mobile Doppler radar since the 1970s. His work and that of the VORTEX field projects (1994, 2009) revealed the inflow geometry that distinguishes tornado-producing supercells. The El Reno tornado of May 31, 2013 — 4.2 km wide, the widest ever recorded — killed researchers Tim Samaras, Paul Samaras, and Carl Young of the TWISTEX team.
Tetsuya "Ted" Fujita, University of Chicago, devised the F-scale (1971); refined to EF-scale 2007.
ENSO — The Oscillation
The El Niño–Southern Oscillation is the dominant year-to-year climate variability on the planet. Trade winds slacken; warm Pacific water sloshes east toward South America; the entire global rainfall pattern shifts. El Niño brings drought to Indonesia and Australia, flood to Peru, mild winters to the northern US. La Niña reverses the pattern. The 1997–98 El Niño is the largest on instrumental record; the 2023–24 event nearly matched it.
Decoding the Weather Machine
Two-hour PBS NOVA documentary on circulation, climate models, and the men and women who chase storms with mobile radar trucks across the Plains. Features Robert Henson, Jennifer Francis, and footage from inside an EF4.
The Sky as Common Property
Robert FitzRoy, captain of HMS Beagle, founded the UK Meteorological Office in 1854 and issued the world's first storm warnings to fishing ports — a public good without precedent. He took his life in 1865, exhausted by the work and by attacks from skeptics. Today some 5 million weather observations are exchanged daily between national services through the WMO's Global Telecommunication System. The atmosphere is a single fluid; you cannot forecast Boston tomorrow without the data from Mongolia today. Weather is the planet's oldest and most successful collaborative project.
"Every weather forecast is a small miracle of physics, computation, and international cooperation." — Tim Palmer, Royal Society