20% chance of thunderstorms

[canyoncaver]

I always understood it that 40% means that 40% of the forecast area will receive rain. Saying that a certain point within the forecast area has a 40% chance that it actually will receive rain, is essentially saying the same thing.

[Brian in SLC]

I always understood it that 40% means that 40% of the forecast area will receive rain. Saying that a certain point within the forecast area has a 40% chance that it actually will receive rain, is essentially saying the same thing.

Nah, not really. Your first statement would be that there's a 100% chance that it WILL rain, but, only in 40% of the forecast area. So, if the forecast was spefically for that area, it would be 100% chance.

But, the calculation for the whole area would yeild a 40% chance, yeah, but, you can't really know that unless the forecast discussion would lead you there.

Slightly different, methinks.

But, "whatever"...ha ha.

Its all an edjumacated crapshoot anyhow.

[mdd]

Nah, not really. Your first statement would be that there's a 100% chance that it WILL rain, but, only in 40% of the forecast area. So, if the forecast was spefically for that area, it would be 100% chance.

But, the calculation for the whole area would yeild a 40% chance, yeah, but, you can't really know that unless the forecast discussion would lead you there.

Slightly different, methinks.

But, "whatever"...ha ha.

Its all an edjumacated crapshoot anyhow.

In other words, the latter is probabilistic, but the former isn't - so they aren't really saying the same thing, all because of the word 'will' in the former.

M

[Brian in SLC]

Yeah, something like that, Mike. If there were a 20% chance of rain in an area, and, it meant that 20% of the forecast area would recieve rain, then folks shouldn't be in a slot canyon anywhere downstream of that area because that interpretation would mean that it would rain, with certainty. But, I don't think it does, so...

Anyhoo. Take care out there!

[spinesnaper]

Ocanier

Keep in mind that we are now entering monsoon season for the Colorado Plateau. Thundershowers are common and the weather can be unstable. Those canyons will always be there so you might consider alternative plans if the weather looks dicey. Remember that flash floods are not simply the water coming down canyon. It also involved water and debris coming down the sides of canyons. These are inherently dangerous environments and your safest choice is to postpone your excursion to a date with better weather.

Ken