Daily `precipType` snow with only one hour of snow `precipType` forecasted

[cloneofghosts]

Describe the bug

I noticed that the API is forecasting a brief period of rain this afternoon with enough accumulation (1.2mm) but the daily summary doesn't mention any rain but maybe this is due to the daily precipType being snow for some reason.

A snippet of today's data is below:

{
  "time": 1740459600,
  "summary": "Mostly Cloudy",
  "icon": "partly-cloudy-day",
  "precipIntensity": 0.0529,
  "precipIntensityMax": 0.254,
  "precipIntensityMaxTime": 1740466800,
  "precipProbability": 0.37,
  "precipAccumulation": 0.127,
  "precipType": "snow",
  "liquidAccumulation": 0.127,
  "snowAccumulation": 0,
  "iceAccumulation": 0,
},

I looked through the hourly data for the rest of the day and the API is only returning the snow precipType for the rest of the day so am confused as to why snow would be showing and not rain. Even if the precipType for the last 9 hours was snow there would still be more rain than snow (13 hours vs 11 hours).

Expected behavior

The API returns rain as the daily precipType and shows the rain icon and summary for the current day

Actual behavior

The API returns snow as the daily precipType and shows the partly cloudy icon and mostly cloudy summary for the current day

API Endpoint

Production

Location

Ottawa, Ontario

Other details

No response

Troubleshooting steps

• I have searched this repository and Home Assistant Repository to see if the issue has already been reported.
• I have read through the API documentation before opening this issue.
• I have not included my API key anywhere in my issue.
• I have written an informative title.

[cloneofghosts]

@alexander0042 If you're looking for a location to test with you can use Essex, UK (51.7704,0.4646). Was looking at the data to see if I could figure out a solution for #428 when I noticed this pop up.

The third day in the daily block has summary Possible Flurries with:

"precipIntensity": 0.0334,
"precipIntensityMax": 0.1259,
"precipIntensityMaxTime": 1741964400,
"precipProbability": 0.4,
"precipAccumulation": 0.10250000000000001,
"liquidAccumulation": 0.0777,
"snowAccumulation": 0.0248,
"iceAccumulation": 0,

There's more rain than snow so the text should be possible drizzle? I don't think it would show Drizzle because there is both rain and snow forecasted with neither reaching the icon threshold.

[cloneofghosts]

@alexander0042 took a quick look at the code and I realized that precipType was calculated using the 4am-4am precipitation whereas the other fields were using the 12am-12am precipitation. Did a quick fix to change it to use the 12am-12am precipitation so this should be mostly fixed.

The only thing left here is how to handle a day with multiple precipitation types but not enough precipitation to reach any of the precipitation (10 mm of rain, 5 mm of snow or 1 mm of ice). Should the precipType be whichever type has the highest amount of precipitation forecasted? Thats what I'm doing for the daily summaries but I can change it if we come up with a better solution.

You could do something like this after the first check or maybe replace the first check with this?

    maxPrecip = max(InterPdaySum[:, 21], InterPdaySum[:, 22], InterPdaySum[:, 23])
    maxPchanceDay[InterPdaySum[:, 21] == maxPrecip] = 4
    maxPchanceDay[InterPdaySum[:, 22] == maxPrecip] = 1
    maxPchanceDay[(InterPdaySum[:, 23] == maxPrecip] = 2

[cloneofghosts]

Thinking about this I don't think checking the maximum precipitation would really be useful. If there are multiple types its very likely that snow or ice will hit their threshold to become the type of precipitation. I'll need to update the summary logic to account for this but should be simple to setup.