The rain gods are cooperating with rain to keep the entry level down to a
reasonable number. Look what happened the day they didn't help--340 drivers!
--Pat K
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>From: "Michael R. Clements" <mrclem@telocity.com>
>To: "Autocross" <ba-autox@autox.team.net>
>Subject: rain -- again? what's going on?
>Date: Fri, Apr 5, 2002, 11:53 AM
>
> In S.F., the average inches of rainfall for Jan, Feb, Mar are 4.4, 3.2 &
> 3.1. Assuming one day of rain is about 0.4 inches on average, that is 11
> days, 8 days and 7.75 days of rain in these months, historical average.
> Total average days of rain for Jan-Mar is 26.75. Total days is 90.25
> (counting Feb as 28.25 for leap years). Thus, a rough average
> probability for any given day from Jan to March to have rain in S.F. is
> about 30%. It's a bit lower for Oakland & GGF.
>
> We have had 4 autocrosses so far, in 3 of which it rained. The
> probability to get rain on all three of these days is 0.3 * 0.3 * 0.3 =
> 0.027. Thus getting rain on all three of these days is only 2.7% likely.
> And that's if they are all in SF. Some were in GGF and Oakland, which
> get slightly less rain, so the probability is actually a bit lower.
>
> Furthermore, now it looks like rain tomorrow morning on the school. This
> further reduces the probability to a number so small that it stretches
> the limits of credulity to imagine that it has occurred naturally.
>
> Can anybody explain what is happening? Is there some phenomena going on
> causing it to rain on every event this year?
>
> Michael R. Clements
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