How to view probability of preciptation?

  • | Premium

    First of all, Windy is awesome! Thanks for creating it!

    I may be missing something obvious, so apologies if I am, but how do I see the probability of precipitation in the forecast?

    All I see in Windy are forecast amounts of precipitation but as far as I can tell that doesn't inform me about the likelihood of precip. Most of the time it doesn't matter to me if it's going to rain 0.1" or 2". What matters more is whether or not it is going to rain at all so I can plan my day.

    I can't tell what the amount on a Windy forecast is supposed to mean. Does 0.5" mean the model indicates it will 100% certainly rain 0.5" at that time? Does it mean that there's some chance between 0-100% that 0.5" of rain will fall at that time? The data seems of limited usefulness without an indication of probability.

    Thanks!


  • Afaik. weather forecast models only provide amount of precipitation, not it's probability.
    To get it simple, if you would just want to know if it will rain or not, then values of 0 mm would mean NO RAIN, while values > 0mm would mean RAIN... Moreover, meteograms available for a given position on the map also provide markers whith sun, clouds and rain drops...

  • | Premium

    Almost all weather apps and websites, including those that run the models like the National Weather Service, provide a probability number with their forecasts. They must use some method to come up with this number. If the models don't generate it, then how is it done? There must be some method beyond a random guess haha


  • These are forecast centers, which don't only use Deterministic models (like e.g. GFS), but also Ensemble models (e.g. GEFS) which allows to compute statistics on different scenarios (there are 21 scenarios for GEFS model, 54 or so for ECMWF). Windy doesn't compute any probability, it just displays models...

Windyty, S.E. - all rights reserved. Powered by excellent NodeBB
NodeBB & contributors, OSM & contributors, HERE maps
Terms and Conditions     Privacy Policy