Vindur
Live wind over the Reykjavík capital region, drawn as particles and scored against real observations.
The idea
A 2 km forecast field animated as particles, with Veðurstofan weather stations laid on top. The animation is not the point. Seeing at a glance where the forecast and the actual measurements disagree is the point.
What I built
A keyless map with no npm dependencies. The model grid comes from Open-Meteo's DMI Harmonie run, the station readings come straight from Veðurstofan, and a scrubber runs from 24 hours back to 48 hours ahead.
The interesting part
It grades itself. An accuracy tab compares every station against the model interpolated to that station's exact coordinates, reporting bias, MAE and RMSE, including the rounds where the model is wrong. And a rule worth stating: scrub away from now and the station markers switch to model values and say so, because a stale reading should never be dressed up as a forecast.
Decisions
A stale reading is not a forecast
Observations only exist for the present. Scrub away from now and the station points switch to model values, and the interface says so.
Pressure was built, then removed
Across a 60 km box, mean sea-level pressure varies by under 1 hPa, so the layer was a flat grey wash. It moved to the meteogram, where the trend is the whole point of a barometer.
Isotherms instead of a colour flood
A fixed diverging temperature scale flooded the map, so temperature is carried by isotherms every 2 °C, with the freezing line picked out brighter.
A server for one missing header
Veðurstofan's station feed sends no CORS header, so the browser cannot read it directly. A small Node server relays it and keeps the accuracy log.