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identityless
2006-Mar-19, 03:31 AM
"There's about a 50 percent chance there will be rain on Saturday and there will be about a 50 percent chance that it will also rain on Sunday. Thus, the weatherman conclude, there's a 100% chance of rain over the weekend."

:D

Ara Pacis
2006-Mar-19, 07:59 PM
In meteorlogy, percentages are not odds of occurance but geographic coverage. If the northern 50% is rained on Saturday and the southern 50% is rained on Sunday, then 100% of the area received rain over the weekend. But you're right, the statement sounds confusing.

hhEb09'1
2006-Mar-19, 08:07 PM
In meteorlogy, percentages are not odds of occurance but geographic coverage.They can be both. But I doubt that any "prediction" could ever be really 100%, unless it's like "I predict 100% chance of rain in the next few seconds" because it's raining hard now.

01101001
2006-Mar-19, 08:58 PM
It's a good thing that Monday rain wasn't also 50% likely, or the weatherman might have said there was a 150% chance that it would rain on one of the 3 days.

01101001
2006-Mar-19, 09:06 PM
In meteorlogy, percentages are not odds of occurance but geographic coverage.

NOAA National Weather Service (Des Moines) FAQ (http://www.crh.noaa.gov/dmx/faq.php)

A 30 percent chance of rain only means that there is a 3 in 10 chance of seeing measurable precipitation somewhere in the forecast area (Measurable means 0.01” or greater).[...] It means that if we issue that forecast 100 times, there will be measurable rain in 30 of them.

Lord Jubjub
2006-Mar-19, 09:29 PM
and, here in Houston, we do get 100% forecasts of rain. Also, at times, the percentage mentioned is the geographic area likely to get rain (at least in Houston). Conditions are ripe for scattered showers but not every place will get rain.

Matherly
2006-Mar-20, 11:40 PM
and, here in Houston, we do get 100% forecasts of rain.

Huh. Maybe my memory is fading, but I though Houston never got a 100% chance of rain, just a 100% chance the sewers would back up.

(So says the Houstonian in Phoenix;))