How to measure snowfall in your area

The big weather pattern change finally arrived at the very end of October. Despite the moisture, Coeur d’Alene’s October precipitation was 1.46 inches. The normal moisture total for October is 2.22 inches, so this was the fourth month in a row with below-average precipitation in Coeur d’Alene. But it’s likely that November will have above-normal moisture as we’re already off to a good start.

With the storm track directed over the northwestern portion of the country, more rain and mountain snow are expected through Tuesday. There’s also the chance of some snow in the lower elevations Tuesday. Then, we should have a brief break from the moisture before more weather systems are likely to arrive next week. Toward the middle of the month, it’s very possible that we could see more significant snowfall in the lower elevations, so we would advise putting on those snow tires. Our current snowfall prediction for Coeur d’Alene is between 80 and 85 inches for the season.

As of early November, there is still a 60% chance of a new La Niña being declared by NOAA’s Climate Prediction Center. The latest information does have a stretch of cooler than normal sea-surface temperatures along the equatorial regions in the south-central Pacific Ocean, but it’s a relatively thin stretch of colder waters.

Despite the equatorial cooling, much of the Pacific Ocean is warmer than normal. It’s estimated that over 70% of this ocean shows sea-surface temperatures above average levels. The warmest areas are east of Japan, the eastern Pacific Ocean near the U.S. West Coast, the Atlantic and Indian oceans. The tremendous warming of the Pacific Ocean has been occurring over the last 10 to 15 years and does not currently show signs of cooling in the near future.

Although a new La Niña has not been declared, the weather pattern has changed to the wetter and cooler side in the western U.S. Rainfall has been reported southward into California where the moisture is needed. As mentioned in other articles, our chances for above-normal snowfalls are higher with a La Niña pattern.

Since Cliff has been in Coeur d’Alene, he has been dedicated to the measurement of snowfall at his station. To answer the many questions concerning the times per day that local Coeur d’Alene area snowfall is tracked, Cliff measures the snowfall, and liquid precipitation as well, every four hours, six times a day, 365 days a year.

He also measures the snow depths at three separate locations in his backyard, including the flat deck that’s away from both the house and trees or other various obstructions. Then, he averages out the three measurements for maximum accuracy. It’s almost hard to believe, but the guy has been measuring snow now for over 70 years! That’s an amazing dedication to the weather.

Cliff systematically measures snow before it melts. If it falls as snow, it’s measured as snow. In this region of the country, we usually see a tremendous amount of melting, especially below 2,500 feet, even in the dead of winter. Therefore, there is a loss of accuracy if snowfall is measured only once per day.

According to NOAA, the measurement of new snow is reported in “tenths” of an inch. For example, if 3 and a half inches of snow falls, it’s reported as 3.5 inches. However, when the snow is melted to get the liquid equivalent, then it’s reported in “hundredths” of an inch, which is what we will report on the Daily Weather Page and weather columns. To get the liquid-equivalent from pure snow, Cliff will take the collected snow in his rain gauge and melt it, usually in a microwave, to get the results.

If one is looking to measure snowfall this season, then consider taking the measurements at a location where the winds will not create snow drifts. If there are areas of snow drifts, then choose several locations to obtain an average. NOAA says that using a snowboard or an open flat surface is the best and easiest way to measure snow. A light-colored board about 2-by-2 feet would be adequate. Other flat surfaces, such as a table or open deck should also work well.

A yardstick would work well to measure the fallen snow. At the time of observation, record the snow to the nearest tenth and then clear the surface for the next observation. Although Cliff measures six times per day, others will measure snow four times every 24 hours. Anything less than four times per day would not be very accurate due to melting.

One of the more creative methods to measure snowfall is to have a web camera pointed at the yardstick and continuously record the amount. I’ve tried this technique and the results were promising.

With the many microclimates in our region, snowfall totals will vary greatly from near the lake to the outlying areas, such as Rathdrum and Athol. Many of the locations away from the lake and city will often report higher totals due to elevation, temperature and other factors.

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Contact Randy Mann at randy@longrangeweather.com.