Weather Services: Official Warnings, Local Forecasts, Model Apps
Three tiers, and the order matters: official warnings first, local forecasts second, model apps third. Reverse that order and you are planning on someone's evening model run.
Weather information comes in three tiers, and the order is fixed: official warnings, then local forecasts, then model or aggregator apps. Official warnings decide whether you change the plan; local forecasts tell you what the next six hours look like at the nearest station or pass; model apps show trends and multi-model agreement. When models disagree, plan for the more conservative one.
Most weather errors are not forecasting errors. They are ordering errors: a hiker checks an aggregator app, sees a green sunny icon, and never looks at the warning that was issued six hours earlier.
Tier 1 — official warnings
- China: China Meteorological Administration (CMA), the National Meteorological Center, and weather.com.cn. Watch for heavy rain, lightning, gale, heat, cold snap and flash-flood warnings.
- United States: the National Weather Service at weather.gov. Learn the difference between a watch, a warning and an advisory — a watch means conditions are favourable, a warning means it is happening.
- United Kingdom: the Met Office. Elsewhere, find the national meteorological service, not a rebranded app.
- An official warning decides whether you change the plan. It is not one input among many.
Tier 2 — local forecasts
- Hourly temperature, feels-like, wind speed and gusts, precipitation, visibility, thunderstorm risk. Not just the daily high.
- Use the nearest station, pass or summit. A valley town 1,500 ft below your route is a different climate.
- Look three times: before departure, on arrival, and before sleep. If the window moves, the plan moves.
Tier 3 — model and aggregator apps
- Windy, Meteoblue and Yr are good for trends and for comparing model runs. They are not official warnings.
- When models disagree, take the conservative one. Do not shop for the run that shows the nicest weather.
- Mind the resolution. Ridges, narrow valleys and local convective storms can fall between model grid points entirely.
- "30% chance of precipitation" is not "it will stay dry". Look at the amount and the timing.
Offline and redundancy
- Screenshot or save the key hours before you leave. There is no signal where you are going.
- Carry a power bank — weather apps drain a phone faster than a map does.
- At least two people in the group should know how to read the forecast. Single points of failure are not only mechanical.
If the only weather source you trust is the one that told you what you wanted to hear, you do not have a weather plan.