I'm going to copy part of the 'newsletter' I just received via e-mail. Given the tragic flash flooding that struck in the Ouachita National Forest in SW Arkansas, this is a timely topic.
Why we do CoCoRaHS?
There are many good reasons why backyard rainfall measurements are
important. But the flash floods in Texas earlier this week and the sad,
devastating campground flash flood in Arkansas just two days ago -- plus
lesser but significant floods in South Dakota, Nebraska, Kansas,
Colorado and other areas -- reinforces powerfully just why we do
CoCoRaHS. Your measurements on any given day may not seem all that
useful or important, but every daily rain gauge measurement helps paint
the picture of where there is moisture and where there is not. Some
day, your report will be the one that matters most of all. Your
"Significant Weather Reports" of heavy rain in progress are especially
useful to weather forecasters since those reports are forwarded
immediately to the National Weather Service. It doesn't matter if it
rained 0.20" or 5.20" in the past hour -- if you think it might help the
NWS, then please send in a report.
For those of you who think that meteorologists already have all the
information they need, please think again. Heavy rains can be incredibly
localized. When you look at the NWS dandy nationwide detailed colorful
precipitation maps produced each day http://water.weather.gov/precip/
it is tempting to think "Who needs CoCoRaHS? They already have every
square mile of the nation covered." But the fact is that those
fantastic maps, which are based primarily on radar data, are only as
good as the rain gauge data used for calibration. Your rain gauge
measurements are used routinely, day after day, in providing baseline
"ground truth" information for U.S. precipitation maps and other
products like them. It doesn't matter if you got a lot of rain, a
little, or none; your report still matters.
And then there is the flash flood in Arkansas this week. I am really,
really sad about it. We didn't have many gauges in that beautiful area
of the state, and even if we did it might not have made a difference.
Those people in that campground did not have access to information about
what was headed their way and didn't have an escape route. They were