Ask A Met: The forecast says there is a 30% chance of isolated thunderstorms in my area. Should I cancel my outdoor plans this weekend?

Jon Erdman: I don't personally gamble, but I do listen to a lot of sports podcasts. I'm fascinated by gambling, but I personally have never sportsbet in my life and probably never will. That said, it might help to think about this question as a matter of chance and risk. If it's 30%, that means just a few storms are forecast to sprout up in the area. Think of popcorn on a map or just a few weeds in your lawn. The chances are pretty good I’ll be fine having, say, a picnic with my family in the park. I'll have the app with me, check the radar occasionally, watch the sky and turn on my alerts to warn of lightning nearby, just in case I can't see the lightning or hear the thunder myself.

But that’s for a picnic, which isn’t much of a headache to cancel at the last minute. If we’re talking about an event like an outdoor wedding, even a 30% chance might be too much of a risk without a backup plan to move indoors. Also, these odds can change throughout the day.

Once it gets above 50% chance, that's when I start to say, “Hmmmm.”

When you get above 60 to 70%, that means if you picked up your radar and looked at it right now, there's probably a cluster of storms headed directly your way, or the expectation of that developing. That's when we start thinking, “This is a bad bet for being outside, today.”

Do you have a question to ask the meteorologists at Weather.com? Write to us at [email protected] and we’ll pick a new question from readers to answer each week.