Latest.csv giving unlikely weather situations

I and others, have noticed for some time that occasionally we’re getting odd forecast descriptions from the latest.csv file which is used for my hourly forecast script. Today it has given: SUNNYCH.SHWR - sunny with a chance of a shower. I have resisted creating a translation for such a condition as surely “with a change of a shower” the sky conditions should be at least “partly cloudy” and not sunny.

Can I ask your opinions please?

It does mean “chance” of a shower. It does sound unusual and I’m not quite sure what’s leading to it in your case. I’ll try to check into that.

I can say that in many places (including here in the summer), many (or most) days are sunny in the morning and early afternoon, and then scattered thundershowers pop up in mid-late afternoon, so “sunny with a chance of a shower” does make sense in those cases. It probably doesn’t sound right in your area, though.


I agree 100% with Tom here.
I had few weeks ago forecasts where WXSIM “missed” the thunder due to its was too clear weather or no rain in the forecast.
In real the weekend was heaviest thunder-weekend here so far this year and WXSIM showed almost no thunder thanks to that.

Here its not uncommon at all that its like Tom said, clear in the morning/midday and thunderstorms grows up during the day at summertime when other conditions are right.
My tought from case 1 in the “no rain = no thunder”-discussion was that it will not work in real life for all and allways.