Interpreting the Weather API

I'm going to add that the list of weather condition codes from openweathermap.org (an organization whose sole proficiency is weather data) has no "chance of" values.

https://openweathermap.org/weather-conditions#Weather-Condition-Codes-2

Also, the Accuweather icon set has no "chance of" values.

https://developer.accuweather.com/weather-icons

I'm going to flag it as a bug that the Garmin APi can return more weather options for current conditions than OpenWeatherMap and AccuWeather can.

I'll see if I can get some formal definitions about these "chance of" conditions. Our data source (which is not strictly openweathermap.org or Accuweather) is the same one used by the system, so you'd see these same conditions outside of Connect IQ apps on devices that support weather, as well. I just don't have any additional info beyond what's in the API docs.

My off-the-cuff interpretation of something like "chance of showers" is that this indicates there are showers in the area, but it may not be raining at your current location. This avoids the problem where it would be completely accurate to report clear conditions but, that could lead someone to a false conclusion that they won't get rained on during their run/ride/etc. It's similar to how forecasts will often give a percentage value for precipitation (e.g. 40% chance of showers), which indicates the % of the viewing area, in the case of a television station, that will likely receive precipitation during a particular time frame.

If I get more info, I'll post here.

I know for me, it can be raining downtown and blue skies where I live (the same city), and if the wind shifts, it can start raining where I am in minutes, so for the area over all, the chance of rain is high.  Having "chance of rain" makes sense to me.

Mark Bolusmjak said:

I'd argue that currently, it is either showering or not.

Sure, that's true for a particular location but the weather you get from any service isn't for the exact location you are at.

I've seen situations where it's not raining where I am but raining 20 feet away.

www.discovery.com/.../chance-of-rain

"According to the National Weather Service, if you see a 40 percent chance of rain, "there is a 40 percent chance that rain will occur at any given point in the area.""

Thanks jim_m_58 and dpawlyk. Let me know your responses to the following:

We already have HourlyForecast.precipitationChance if we want the chance of rain. So why must we also require a new constant that is derived from that value in an opaque way? 

But also, we can have CONDITION_CLOUDY_CHANCE_OF_RAIN, and CONDITION_CHANCE_OF_SHOWERS. So is that to guarantee that CONDITION_CHANCE_OF_SHOWERS implies it is NOT currently cloudy? And what about CONDITION_CHANCE_OF_THUNDERSTORMS: does that mean it's cloudy or raining or sunny with a change of thunderstorms (because all of those are possible). Where is CONDITION_CLOUDY_CHANCE_OF_SHOWERS?

I understand that Garmin might be pulling from different APIs based on the phone OS and location, and it might get incongruent results from different services. But it would be nice if those nuances were reflected in the API or, at minimum, documented so that developers could understand how to interpret results.

Lots of helpful definitions and detective work. Thank you.

Found an article explaining that "chance of" indicates 30-50% likelihood of an event, and "scattered" indicates 30-50% areal coverage of precipitation. And the API differentiates between CONDITION_CHANCE_OF_THUNDERSTORMS, and CONDITION_SCATTERED_THUNDERSTORMS. So if there are "scattered" thunderstorms in your area, there is a "chance of" one being directly over you. Yet these are strictly independent event constants in the API. 

I do think the above clarifications (and remaining mysteries) are better address via API design or clearer documentation. As opposed to further discussion here. 

> You really don't need a device to tell you the weather at your present position and current time. 

... if at your position you have a view outside, including a view of the sky.

Mark Bolusmjak said:

... if at your position you have a view outside, including a view of the sky.

If you are inside, you don't really care about the weather at that moment.

You might care about the weather at that location (actually, someplace nearby your indoor location) at some time in the future (when you will actually be outside).

If you don't have a view outside (sometimes, even if you do!), the device won't know your location very accurately (or at all). So, even if you wanted to know the weather outside, the Edge is the wrong way to get it.

Most often, people will have some access to a window (I used to work in a place that had no windows (and that was weird). Looking outside (if that's an option) is going to generally be much more accurate than a weather report.

And the weather report isn't always going to be that accurate for your specific location. Which means you'd be better off going to a window and looking for the weather at your location and current time.

Weather reports are, in part, based on weather stations and there aren't that many of these (often, the nearest one to your location will be at the nearest airport). Weatherunderground is unusual because they can use weather stations that regular people set up.

In any case, the weather report at your current location and time is often wrong. Looking outside is going to be much more accurate.

I am the SOLE authority about what I care about and why.

And I want to look at my watch and see the current conditions.

Mark Bolusmjak said:

I am the SOLE authority about what I care about and why.

You (are more or less) asking Garmin to do work in support of "what you care about any why". They aren't going to do that if it that isn't something that a fair number of other people want also. So, the reasonableness of what you want does matter.

Mark Bolusmjak said:

And I want to look at my watch and see the current conditions.

The weather report for your current location and time is often going to be wrong.

While it's nice to see the current weather on your wrist, it doesn't make much sense to put much faith in it.