CoCoRaHS ~ because every drop counts! (Citizens and schools can help measure precipitation)

December 4, 2017

CoCoRaHS (pronounced KO-ko-rozz) is an acronym for the Community Collaborative Rain, Hail and Snow Network.

CoCoRaHS is a unique, non-profit, community-based network of volunteers of all ages and backgrounds working together to measure and map precipitation (rain, hail and snow).

The National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation (NSF) are major sponsors of CoCoRaHS. Other organizations have contributed either financially, and/or with supplies and equipment.

CoCoRaHS has over 20,000 volunteer observers in all 50 U.S. states, Puerto Rico, the U.S. Virgin Islands, Canada and the Bahamas. Of the network’s 333 coordinators, 254 work closely with NOAA.

By using low-cost measurement tools, stressing training and education, and utilizing an interactive website and apps, the aim is to provide the highest quality data for natural resource, education and research applications.

Why is there so much interest in rain, hail and snow?

Precipitation is essential for life. It varies greatly with topography, storm type and season. It really is true  that  it  may  pour  on  one  side  of  the  street and be dry on the other. A portion of a field may be pounded by hail while others nearby receive no damage. Snowfall may pile up in one neighborhood and only dust another. Rain, hail and snow are fairly easy to measure, and the data collected are very important.

Who uses CoCoRaHS?

CoCoRaHS is used by a wide variety of organizations and individuals. The National Weather Service, other meteorologists, hydrologists, emergency managers, city utilities (water supply, water conservation, storm water), insurance adjusters, USDA, engineers, mosquito control, ranchers and farmers, outdoor & recreation interests, teachers, students, and neighbors in the community are just some examples of those who visit their Web site and use the data.

What does a volunteer observer do?

Each time a rain, hail or snow storm crosses your area, volunteers take measurements of precipitation from as many locations as possible. These precipitation reports are then recorded online at or through CoCoRaHS’ app.

The data are then displayed and organized for many of their end users to analyze and apply to daily situations ranging from water resource analysis and severe storm warnings to neighbors comparing how much rain fell in their backyards.

It’s easy to join, takes only five minutes a day and is a fun way to learn about weather.

People of all ages can help. The only requirements are an enthusiasm for watching and reporting weather conditions and a desire to learn more about how weather can affect and impact our lives.

Complimentary training is provided to help you become an effective weather observer. Check out your state page for a list of current training sessions in your local area.  If none are taking place at the current time, CoCoRaHS has online and PDF Training Slideshows.

Can schools participate?

Absolutely! A great benefit of CoCoRaHS is that it provides real science activities for the classroom in public, private, and home schools. Over the last several years CoCoRaHS staff has worked with science teachers to develop a series of lesson plans and activities. These lesson plans are available for a variety of grade levels and are built around CoCoRaHS’s emphasis on measuring precipitation.

Watch and share below short CoCoRaHS for Schools video…


CoCoRaHS also has lesson plans and activities developed for the 4-H Program that are aligned with National Science Education Standards (NSES) for grades K-4, 5-8 and 9-12. Visit CoCoRaHS for Schools to learn how your school or program can join.

Help spread the word

Please take a moment to share this post and tell a friend or neighbor about CoCoRaHS exciting grassroots effort of citizens measuring precipitation in their own backyards. Again, it’s easy to join, takes only 5 minutes a day and your observations give scientists an ever clearer picture of where and how much precipitation falls throughout our communities.

Learn more about CoCoRaHS at and follow them on their blog, Facebook and Twitter and get involved!


Snow plows in July?? (NM storm dumps over a foot of hail clogging roads)

July 12, 2013

hail piles up city street santa rosa fdThe Weather Channel reports a lone thunderstorm dumped over a foot of hail in the town of Santa Rosa, New Mexico last Wednesday evening (July 3, 2013), leaving a surreal sight the day before the Fourth of July.

Photos from the Santa Rosa Fire Department showed snow plows clearing city streets clogged with accumulated hail drifts. According to the National Weather Service in Albuquerque, hail up to golfball size pelted the city around 6:00 p.m. MDT.

Although this sounds strange, accumulating hail is not uncommon in the High Plains according to TWC. Northeast New Mexico sits in what meteorologists call “Hail Alley“, a swath from southeast Wyoming and northeast Colorado to northeast New Mexico and the Texas Panhandle, where large hail falls on average at least three days a year.

And, considering much of the country is sweltering with intense heat, we thought this might be a “cool” set of Friday Fotos to share.

hailstorm santa rosa police vehicle new mexico state police

A police vehicle navigates a hail-clogged street in Santa Rosa, N.M. on July 3, 2013. (Credit: N.M. State Police)

hail santa rosa photo by nm state police

A few of accumulated hail on a street in Santa Rosa, N.M. on July 3, 2013. (Credit: N.M State Police)

record hailstone vivian sd nws

As fyi … above is the record-setting hailstone that fell in Vivian, South Dakota on July 23, 2010. The hailstone broke the U.S. records for largest hailstone by diameter (8 inches / 20 cm) and weight (1 pound 15 ounces). Credit: NWS Aberdeen, SD

TWC writes some other unusual hailstorm events include:

  • April 11, 2012 (Dumas, TX): The volume of both hail and rain overwhelmed a shallow gully, or draw, near the U.S. 287 bridge, piling the water and ice mass into massive drifts up to 10 feet high, trapping vehicles and forcing closure of the road for 12 hours.
  • August 14, 2004 (Clayton, NM): Up to 16-foot hail glaciers. Some ice cover lasted almost a month…even in late summer!
  • May 9, 1994 (Dalhart, TX): Up to three-foot hail drifts shutdown U.S. 385 for almost one month

We also found a short video by TWC’s Dr Greg Forbes explaining how thunderstorms produce hail.

Stay safe and cool out there .. and have a great weekend! 🙂 j & B

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