Plaincast is a free, independent website that takes the National Weather Service's Area Forecast Discussion — the real forecast, written 3 to 4 times a day by the meteorologist on shift — and translates it into plain English.
An Area Forecast Discussion is the most informative weather product the government publishes and the least readable. It is where a forecaster explains their reasoning: which models disagree, what they are watching, how confident they are, and what would have to change for the forecast to bust. None of that survives the trip to a weather app icon. But it is written in dense shorthand for other meteorologists — "hgts fall aft 12Z w/ shrtwv trof apchg the cwa" — so almost nobody outside the field reads it.
Plaincast puts the plain-English summary beside the annotated original, so you can read the translation and still check the forecaster's actual words. Nothing is hidden behind the summary.
How it works
- The latest discussion is fetched live from the National Weather Service API for any of 68 forecast offices. Nothing is scraped, and no key is required — it is public data.
- Each section is summarized by Anthropic's Claude Haiku into readable prose. The model summarizes; it never forecasts, and it is never asked to add information the forecaster did not write.
- The original text is annotated in parallel: 230+ meteorological terms carry hover definitions, 109 abbreviation patterns are expanded, and Zulu times are converted to the office's local clock.
- A confidence reading is derived from the forecaster's own hedging language — "high confidence" and "models diverge" are counted, not guessed at.
- Every page is readable without JavaScript and without AI: the server renders a decoded plain-text edition first, and the interactive one loads over it.
Where the data comes from
Every forecast, alert, and outlook on this site originates with the National Weather Service and the Storm Prediction Center, both part of NOAA. Plaincast adds no observations, no model runs, and no forecasting of its own. It is a reading layer, not a source.
Plaincast is not affiliated with, endorsed by, or operated by NOAA, the National Weather Service, or any government agency.
When not to use it
For a life-safety decision, read the original. During a warning, go to weather.gov or your local office directly — Plaincast summarizes a discussion product that can be up to six hours old, and a machine translation is one more layer between you and the forecaster. Plaincast is for understanding the forecast, not for taking shelter.
Who makes it
Plaincast is built and run by Jonah Berg as an independent project. It is free, has no accounts, runs no ads, and sells nothing. The source is public.
- Source code: github.com/jonahberg/plaincast
- The author: jonahberg.com
- Get in touch: /contact