Topic: Rainlog.org

[miraculon]

I came across a site called "Rainlog.org". It seems to be similar to CoCoRaHS, but is mainly for Arizona from what I can tell.
They seem to have the same objective as CoCoRaHS, and seems kind of redundant.
It does have some good tips in their gauge area. They recommend mineral oil to prevent evaporation. It is probably not needed here in Michigan, but I can see the need in AZ. (I was just there last week)
There are some non AZ contributors, but the intent is for Arizona data collection.

One key difference that I noticed was that they do accept "automatic" (tipping bucket) rain gauge data.

http://rainlog.org/usprn/html/main/maps.jsp

Greg H.

[CW2274]

Jeez, I live here and never saw this. However, I'm usually satisfied with what I do see so I don't go out looking around...

[DaleReid]

I followed this over from another thread about mineral oil to prevent evaporation during the day.

Greg, it is curious as to your comment that they do allow the use of a tipping bucket or automatic rain gauge.

This implies that the cocorhas or how ever it is spelled does not do so.

Is there any logic to that prohibition of tipping buckets, or the idea that a scratch baked cake tastes better than a store bought one, and that's the way GrandPa did it, so dang it, we're going to do it that way too!

I am fiddling with an RM Young capacitance gauge right now and from it's construction seems to be lessor surface area to evaporate, plus the electronics give a readout whenever queried, so if it goes to say 0.08 inches and then back tracks during the day, it is obvious there'd be evaporation. 

Beautiful country, but brutal at times and I'm glad for the green and rain up here in Sunny Wisconsin!
Dale

[nincehelser]

http://www.cocorahs.org/Content.aspx?page=faqgeneral#autogauges

Why does CoCoRaHS not use automated rain gauges?

We are often asked why CoCoRaHS does not encourage the use of automatic rain gauges to report 24 hour precipitation totals.  After all, many weather enthusiasts already have electronic home weather stations with automatic rain gauges to record precipitation  -  why should they also purchase a separate CoCoRaHS gauge?

Unfortunately, it turns out that rain gauges are not all created equal and do not all report the same.  The Colorado Climate Center has been involved in rain gauge studies for many years and have had dozens of volunteers like you test their automated gauges against either the CoCoRaHS 4" diameter gauge or the National Weather Service (NWS) 8" diameter Standard Rain Gauge.  We have also tested National Weather Service Automated Surface Observing System tipping bucket rain gauges  (not unlike the tipping bucket gauges that come with most home weather stations, but sturdier and a lot more expensive).

While the NWS and CoCoRaHS gauges compare quite well with each other (our tests indicate that the CoCoRHS gauge has a collection efficiency of 101-105% compared to the standard NWS gauge), the majority of automated rain gauges, when summed over several months or years, report less precipition than actually fell by a significant amount -- sometimes 25% or more.  Moreover, none of the automated gauges  work well in areas that receive snow.  This is not acceptable for our project because we are interested in observing and understanding natural precipitation variability, as accurately as possible.  If we're all using different kinds of gauges with different abilities to catch precipitation, it's too hard to determine if differences in rain or snowfall are "real" or due to the kind of instrument that was used to report the measurement.

Because of these test results, we have asked our observers to please set up a CoCoRaHS 4" gauge along with their automated gauge and see for themselves.  Many observers have converted to using the 4" gauge as their daily measurement when they see the results, and then use their automated gauge as a backup when they are gone.  It is very good to use the two in combination.  But whenever people do use their automated gauge as their measurement, we request that they mention that in the daily "observation notes".

For those of you who decide it's too much trouble to purchase a CoCoRaHS gauge in addition to your automatic system, you may still be able to share your data with the National Oceanic and Atmospheric Administration (NOAA - the organization that oversees the NWS) via their Citizen Weather Observation Program (CWOP).  This program makes home weather station data available to the NWS for certain real time applications. WeatherUnderground is another system for web-based data sharing. 

For climate data and research applications, as well as supporting the "NowCasting" goals of NOAA, we encourage you to use the 4" diameter high capacity manual rain gauge and join CoCoRaHS.

[DaleReid]

Thanks,
I had the page with some general info but didn't look for a FAQ or more.

Nice discussion.

[ValentineWeather]

Nebraska has its own network also called NeRain  http://nerain.dnr.ne.gov/NeRAIN/docs/equip.asp  They also required the standard 4" plastic gauge and work together with Cocorahs.