"---- Year Rain" Probability
Name: Donald W. J.
In August of 2000 heavy rains of up to 14 inches hit the
area around Sparta New Jersey. The was the result of an apparently
unusual storm that hung over the area and continued to dump rain. The
average monthly precipitation for the area is about 4.5 inches.
My question is this:
Is there any way to determine the probability that such a rain event will
occur in 1 year, 5 years, 10 years, 20 years?
And if so,what is that probability?
There is no way of "calculating" the probability of such an event. You can
arrive at a sort of probability by looking back at the historical record of
rainfall and see how often a certain rainfall occurred, but that is not a
Commonly, the frequency of extreme weather events can be determined
simply by seeing how many events have occurred in a certain period
during the past. This requires digging back through the weather
data of the past 100 years or so. These statistics have been
compiled for most of the National Weather Service (NWS) observation
stations. I recommend calling your local NWS office to see if they
have this information.
David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory
Click here to return to the Weather Archives
Update: June 2012