Hilberg's Tips -- Reporting Hail

As you know "hail" is part of the CoCoRaH S name. Spring is prime time for hail, especially the large variety, but it falls in different parts of the country during various seasons, often summer. We often see observers mention hail in their comments, but then forget to submit a separate hail report. When you observe hail, please submit a hail report as soon as possible with as much information as you can provide (you can always go back and add to or edit your report later). As soon as you submit the hail report it is also transmitted to your local National Weather Service office. These reports are critical in severe weather situations and may be one of the triggers for a severe thunderstorm warning, for example. You can find the link to the hail report in the left hand menu once you log in.

Once the hail report displays, fill out as much information as you have at the time, but be sure to include the date, time, and size of the hailstones. Note that often there will be larger hailstones among a fall of smaller stones. For example, you may be observing many 1/4 inch stones (pea-size), and at the same time may see a few larger hailstones falling as well. Again, you may go back and update your report, for example, after you have had a chance to see if there was any damage. Note that the Hail report is NOT yet available on the mobile app.

Safety is of critical importance! Observe from the safety of a building. DO NOT run outside to pick up or measure large hail stones in the middle of a storm. Stay away from windows, especially if the wind is blowing and/or there is lightning.

Hail size is easy to estimate by comparing the hail to the size of common objects, from coins to softballs. Not all hailstones are round. Some look like oblong potatoes or have jagged spikes protruding. When measuring hail or estimating its size, use the measurement along its longest axis. 

You can download this handy pocket hail size guide from the Illinois CoCoRaHS web page. The rule on the bottom is to scale and fits on a 3x5 card. Make multiple copies and keep one at home, in the car, or at work.

Finally, review hail measurement procedures by viewing our CoCoRaHS hail measurement training animation.