How to measure snowfall the right way
A quick step-by-step guide to get an accurate snow total in your backyard.
By
Alyssa Glenny, AccuWeather Meteorologist
Assisted by Ramesh Gautam, left, Sean de Guzman, chief of snow surveys for the California Department of Water Resources, measure the depth of the snowpack during the second snow survey of the season at Phillips Station near Echo Summit, Calif., Wednesday, Feb. 3, 2021. The survey found the snowpack at 63 inches deep with a water content of 17 inches. (AP Photo/Randall Benton)
When Mother Nature unloads heavy snowfall in the winter, snow-lovers may be eager to suit up, step out and take measurements. And meteorologists, particularly with the National Weather Service (NWS), rely on accurate snow reports from the public to figure out precise snow totals across a region, because snow varies greatly over small distances and can't be easily measured automatically.
Taking snowfall measurements may sound like a simple task — and it can be — if you have the proper equipment and some key tips to properly measure the snow. Not only will accurate measurements provide an understanding of how much snow has fallen, but they can also play a significant role in improving local weather forecasts.
In order to measure snowfall accurately, there are a few guidelines that storm spotters, such as Community Collaborative Rain, Hail and Snow Network (CoCoRAHs) volunteers, should follow. The process begins with collecting a few simple supplies: a measuring stick, a snow board and a rain gauge cylinder.
The measuring stick can be any ruler that has values clearly marked in measures of tenths of an inch. A typical yardstick can be used.
A snow board used for measuring snowfall is not the same one you bring with you to a ski slope, but rather it is a lightly-colored plywood board that is roughly 16 inches in size. A rain gauge cylinder will be needed only for those measuring the liquid-equivalent of snowfall, which is not required by most organizations.
There are three primary types of snowfall reports that are submitted: new snowfall, existing snow depth and, for advanced users, the amount of liquid-equivalent snowfall.
New snowfall measurements include the amount of snow that has accumulated since the last measurement, or it can be the total snow measured from a fresh event. New snowfall measurements are reported to the nearest tenth of an inch and displayed, for example, like this: 2.1 inches.
Determining snow depth involves measuring the snowfall that has piled up from single or multiple events and reflects the total amount of snow presently on the ground in a given area. Snow depth measurements are reported to the nearest inch. AccuWeather forecasters recommend measuring several times and averaging the measurements to get a reliable snow-depth report.
For meteorological purposes, the liquid equivalent of snowfall can be measured to determine the amount of liquid within. This involves melting the snow that has fallen in the rain gauge cylinder and measuring the amount of liquid the same way you would if rain had fallen. This requires melting a core sample from the snow board into a rain gauge. The liquid equivalent of snowfall is reported in hundredths of an inch, like this, for example: 0.21 of an inch.
Once the supplies are collected and you know which type of report you are measuring for, the next step is to determine the location where measurements will be taken. It is best to choose a flat piece of grassy or dirt land on which to place your snow board and ensure that the spot is not obstructed by buildings or trees.
“Spots next to buildings may shield some snowfall or allow a facing wind to pile up lighter snow, skewing measured snowfall totals,” explained AccuWeather Meteorologist Adam Sadvary.
Additionally, Sadvary stated that it’s best to avoid measuring snow on asphalt or a dark, paved area, as temperatures on these surfaces are typically higher than surrounding surfaces. Daytime heating can be absorbed and leave dark surfaces warmer than their lighter counterparts. This can result in initial snowflakes melting as they fall, leading to lower snowfall amounts than on a grassy surface or snowboard.
Once the snowboard has been placed in a location where influences that can skew measurements are minimized, note the location with a flag or reflector. This step is done to ensure you can locate the snow board once the snow has accumulated.
It is important to consider if you are taking snowfall measurements where drifting typically occurs. In a snowdrift, totals can be skewed higher than they actually are. On the other hand, in an area where snow has been blown away, measurements will be skewed lower than they actually are. Therefore, it's important to be aware of the nature of the wind when measuring snow amounts.
To use the measuring stick properly, meteorologists say it is important to hold it upright, measure at eye level and take several measurements across the snow board to get an average snowfall total. Up to 10 measurements would be optimal in order to calculate an average.
A snow ruler is used to measure snow at the National Weather Service in State College, PA (NOAA)
Timing is a key factor when seeking accurate snow measurements. The NWS advises measuring as soon after snow stops falling as possible to avoid lower totals due to melting, compaction or drifting.
After recording a snow measurement to the nearest tenth of an inch, the NWS recommends wiping all of the snow off the snow board and placing the board on top of the snow. Then, you're ready for your next measurement.
Observers can send measurements to AccuWeather or their local NWS office via websites or social media or via the CoCoRaHS website -- the latter requires registration and training first. It is important to include the location where the measurement was taken in a snowfall report as well as the timeframe of the report, including when snow began and ended.
You can also order brass or plastic snow stakes, rulers or gauges online that you can temporarily or permanently place in your yard, but these generally are not useful for official measurements due to the complicated nature of measuring snow correctly.
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How to measure snowfall the right way
A quick step-by-step guide to get an accurate snow total in your backyard.
By Alyssa Glenny, AccuWeather Meteorologist
Assisted by Ramesh Gautam, left, Sean de Guzman, chief of snow surveys for the California Department of Water Resources, measure the depth of the snowpack during the second snow survey of the season at Phillips Station near Echo Summit, Calif., Wednesday, Feb. 3, 2021. The survey found the snowpack at 63 inches deep with a water content of 17 inches. (AP Photo/Randall Benton)
When Mother Nature unloads heavy snowfall in the winter, snow-lovers may be eager to suit up, step out and take measurements. And meteorologists, particularly with the National Weather Service (NWS), rely on accurate snow reports from the public to figure out precise snow totals across a region, because snow varies greatly over small distances and can't be easily measured automatically.
Taking snowfall measurements may sound like a simple task — and it can be — if you have the proper equipment and some key tips to properly measure the snow. Not only will accurate measurements provide an understanding of how much snow has fallen, but they can also play a significant role in improving local weather forecasts.
Want accurate snow totals? Start with a good measuring board
In order to measure snowfall accurately, there are a few guidelines that storm spotters, such as Community Collaborative Rain, Hail and Snow Network (CoCoRAHs) volunteers, should follow. The process begins with collecting a few simple supplies: a measuring stick, a snow board and a rain gauge cylinder.
The measuring stick can be any ruler that has values clearly marked in measures of tenths of an inch. A typical yardstick can be used.
A snow board used for measuring snowfall is not the same one you bring with you to a ski slope, but rather it is a lightly-colored plywood board that is roughly 16 inches in size. A rain gauge cylinder will be needed only for those measuring the liquid-equivalent of snowfall, which is not required by most organizations.
Know the types of snowfall reports
There are three primary types of snowfall reports that are submitted: new snowfall, existing snow depth and, for advanced users, the amount of liquid-equivalent snowfall.
New snowfall measurements include the amount of snow that has accumulated since the last measurement, or it can be the total snow measured from a fresh event. New snowfall measurements are reported to the nearest tenth of an inch and displayed, for example, like this: 2.1 inches.
Determining snow depth involves measuring the snowfall that has piled up from single or multiple events and reflects the total amount of snow presently on the ground in a given area. Snow depth measurements are reported to the nearest inch. AccuWeather forecasters recommend measuring several times and averaging the measurements to get a reliable snow-depth report.
For meteorological purposes, the liquid equivalent of snowfall can be measured to determine the amount of liquid within. This involves melting the snow that has fallen in the rain gauge cylinder and measuring the amount of liquid the same way you would if rain had fallen. This requires melting a core sample from the snow board into a rain gauge. The liquid equivalent of snowfall is reported in hundredths of an inch, like this, for example: 0.21 of an inch.
Finding the best spot to measure
Once the supplies are collected and you know which type of report you are measuring for, the next step is to determine the location where measurements will be taken. It is best to choose a flat piece of grassy or dirt land on which to place your snow board and ensure that the spot is not obstructed by buildings or trees.
“Spots next to buildings may shield some snowfall or allow a facing wind to pile up lighter snow, skewing measured snowfall totals,” explained AccuWeather Meteorologist Adam Sadvary.
Additionally, Sadvary stated that it’s best to avoid measuring snow on asphalt or a dark, paved area, as temperatures on these surfaces are typically higher than surrounding surfaces. Daytime heating can be absorbed and leave dark surfaces warmer than their lighter counterparts. This can result in initial snowflakes melting as they fall, leading to lower snowfall amounts than on a grassy surface or snowboard.
Once the snowboard has been placed in a location where influences that can skew measurements are minimized, note the location with a flag or reflector. This step is done to ensure you can locate the snow board once the snow has accumulated.
Where to take snowfall measurements
It is important to consider if you are taking snowfall measurements where drifting typically occurs. In a snowdrift, totals can be skewed higher than they actually are. On the other hand, in an area where snow has been blown away, measurements will be skewed lower than they actually are. Therefore, it's important to be aware of the nature of the wind when measuring snow amounts.
To use the measuring stick properly, meteorologists say it is important to hold it upright, measure at eye level and take several measurements across the snow board to get an average snowfall total. Up to 10 measurements would be optimal in order to calculate an average.
A snow ruler is used to measure snow at the National Weather Service in State College, PA (NOAA)
Timing is a key factor when seeking accurate snow measurements. The NWS advises measuring as soon after snow stops falling as possible to avoid lower totals due to melting, compaction or drifting.
After recording a snow measurement to the nearest tenth of an inch, the NWS recommends wiping all of the snow off the snow board and placing the board on top of the snow. Then, you're ready for your next measurement.
Observers can send measurements to AccuWeather or their local NWS office via websites or social media or via the CoCoRaHS website -- the latter requires registration and training first. It is important to include the location where the measurement was taken in a snowfall report as well as the timeframe of the report, including when snow began and ended.
You can also order brass or plastic snow stakes, rulers or gauges online that you can temporarily or permanently place in your yard, but these generally are not useful for official measurements due to the complicated nature of measuring snow correctly.
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Want next-level safety, ad-free? Unlock advanced, hyperlocal severe weather alerts when you subscribe to Premium+ on the AccuWeather app. AccuWeather Alerts™ are prompted by our expert meteorologists who monitor and analyze dangerous weather risks 24/7 to keep you and your family safer.
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