About Weather Forecasting
Forecasting begins with measurements from the entire atmosphere. Computers combine observations with physical equations to estimate the current state, then calculate how conditions may evolve.
Weather Stations
Surface stations measure temperature, pressure, humidity, wind, and precipitation.
Learn MoreWeather Balloons
Radiosondes rise through the atmosphere beneath balloons.
Learn MoreSatellites
Weather satellites observe clouds, temperature, moisture, fires, ice, oceans, and storms.
Learn MoreRadar
Weather radar sends radio waves and measures echoes from precipitation.
Learn MoreComputer Models
Forecast models solve equations describing atmosphere and oceans.
Learn MoreEnsembles
Ensemble forecasts run models many times with slightly different starting conditions.
Learn MoreMeteorologists
Human forecasters interpret model guidance and local conditions.
Learn MoreForecast Limits
Forecast skill decreases with time.
Learn MoreWeather Stations
Networks of stations provide continuous local observations.
Weather Balloons
They measure temperature, moisture, pressure, and wind from the surface into the stratosphere.
Satellites
Geostationary satellites repeatedly view the same region, while polar orbiters scan the whole planet.
Radar
Doppler radar also measures motion toward or away from the radar.
Computer Models
Different models use different resolution, physics, and data-assimilation methods.
Ensembles
The spread helps estimate forecast uncertainty.
Meteorologists
Experience matters especially for terrain, coastlines, convection, and rapidly changing hazards.
Forecast Limits
The atmosphere is chaotic, so tiny initial uncertainties can grow into larger differences days later.