Probability of Rain Math Question

[BoomerD]

That you think under 2" of rain in 24 hours is notable sort of illustrates my point. Seattle rainfall per year is only about 37"

The small town where I live...on the Olympic peninsula...does a bit better...

Average annual precipitation - rainfall: 56.37 inch

Still not "Forks quantities," but not bad either.

 

[Fenixgoon]

If there is a 20% chance of rain today, 60% chance tomorrow, and 20% chance of rain in two days, what is the probability it will rain over the next three days? Anyone know how to figure that out? College stats seems like 20 years ago........

probably of it raining: day1/day2/day + day1/noday2/day3 + day1/day2/noday3 + day1/noday2/noday3 + noday1/day2/noday3 + noday1/noday2/day3

or.... 1 - the probably it will not rain on all 3 days (0.8*0.4*0.8)

 

[DrPizza]

Unfortunately, the above calculations are probably wrong. Those calculations are based on the probability of 3 independent events. I don't think successive weather forecasts are independent.