Volunteers needed assist in providing weather data for CoCoRaHS

Do you keep a rain gauge and check it regularly? Does it seem that the drought monitor doesn’t see the droughts you experience? If so, you may be interested in participating in the Community Collaborative Rain, Hail and Snow Network or CoCoRaHS.

Who uses CoCoRaHS data?

CoCoRaHS is not just a fun activity. The reports are used by many agencies and weather scientists. The National Weather Service looks at reports to track storms and their variability. Reports also help inform the United States Drought Monitor creators. Weather modelers compare reports to radar information to improve predictions. In addition to their weather spotters the NWS warning system relies on CoCoRaHS ‘significant weather reports.’ Many others use the data including emergency managers, insurance adjusters, USDA and engineers.

Additionally, various drought and range condition models and monitors are looking at using CoCoRaHS data. Currently, most of these models use National Weather Service COOP stations and/or state sponsored automated weather stations. But these stations are widely scattered across the west. This leaves large gaps to fill in with statistics — and opportunities for error.

Those gaps would shrink enormously if every person that has rain gauge(s) reported their results.

Knowing what rain or snow did, or didn’t, fall would vastly improve drought monitoring, forage and crop production predictions, and disaster assistance planning.

Can I use my rain gauge?

CoCoRaHS does require that you use a four inch diameter high-capacity manual precipitation gauge. Most automated rain gauges report less rainfall than the reference NWS Standard manual rain gauge. These differences can be 10 percent or more — especially for storms with high intensity rainfall. Gauges with small openings are also notoriously inaccurate. The four inch gauges are within one to five percent of the NWS gauges.

The gauge is easy to purchase from weatheryourway.com (or other sources). One nice feature is that the funnel reduces evaporation significantly. So, you don’t have to beat the sun to your gauge every morning. If your gauge is in a remote location, you can simply submit multi-day reports. You do not have to read it every day. If it will be several days between checks, you can add a small amount of vegetable oil to your gauge to reduce evaporation even more. Just remember to subtract the oil from your report.

Because the gauge holds 11 inches of water, most Eastern Colorado downpours are not a problem.

How do I join CoCoRaHS?

Curious? Check out their website http://www.cocorahs.org. On the front page you will see the maps the volunteers make possible. If you want to volunteer, the sign-up link is on the left-hand side. Once you have a gauge, simply log in and report your moisture. Zeros often are more important than rain, so don’t skip the days when your gauge is empty.

Each volunteer is valuable in helping to fill in a piece of the weather puzzle. These pieces are crucial for researchers, drought and flood monitors, and many others to make accurate assessments of conditions in your area.