What POP really means in a weather forecast

'POP' or 'probability of precipitation' has long been a source of confusion for those trying to make sense of their forecast.

The POP, or probability of precipitation, feature is commonly found on weather apps and forecasts. You can see it on our forecast pages as well, in a column that looks like this:


Chris Murphy, a Weather Network broadcast meteorologist, says POP functions like an added tool to help plan the day.

When an area has an 80 per cent POP of rain or snow in the morning, for example, it doesn't mean that there will be precipitation for 80 per cent of the morning, or that 80 per cent of the area will be covered in rain or snow.

"It simply means that if this exact same storm system went through 10 times, 8 out of 10 times it would bring you precipitation within that forecast period," Chris says.


If the POP drops to 30 per cent in the afternoon, "there's only a 3 out of 10 chance you'll get any precipitation from this scenario."

So—while meteorologists can't tell the future, they can use probability to predict outcomes, not unlike what we see during elections, sports finals, and financial investments.

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Watch the video above to learn more.

Header image source: Victoria_Regen via Pixabay.