By FLI Products – Official Distributor of the Stratus Precision Rain Gauge

 

❄️ Winter Snow Measurement 101 with the Stratus Precision Rain Gauge

Accurate winter precipitation measurements matter. Whether you’re part of CoCoRaHS, a weather enthusiast, a school researcher, or a hydrology professional, understanding snowfall and snow-water equivalent provides critical data for water forecasting, climate research, and storm reporting.

And there’s no better tool for the job than the Stratus Precision Rain Gauge, distributed by FLI Products, the official 4" diameter gauge recommended by CoCoRaHS and trusted by NOAA observers nationwide.

This guide—written by a meteorologist and snow-measurement specialist—breaks down the three official CoCoRaHS winter measurement techniques, with clear instructions and field-tested recommendations.

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🌨️ Why Measuring Snow Is More Challenging Than Rain

Snowfall measurement introduces unique complexities:

• Settling and compaction

• Wind redistribution

• Melting during storms

• Variations in density

• Refreezing inside gauges

Despite the challenge, winter measurements are vital. Scientists need detailed snowfall data just as much as rain and hail, and snowmelt is a major contributor to the U.S. water supply.

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🌨️ The 3 Official Winter Snow Measurement Methods

(From CoCoRaHS Winter Training & NOAA Guidelines)

In order of difficulty:

1️⃣ Snowfall Only (Depth Measurement)

2️⃣ Liquid Equivalent from the Gauge

3️⃣ Liquid Equivalent from a Snow “Core Sample”

Each method adds value—you may choose one, two, or all three depending on conditions.

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1️⃣ Snowfall-Only Measurement

Your Essential Tools:

• Snowboard (16" × 16" white-painted plywood recommended by CoCoRaHS)

• Yardstick or snow ruler

Where to Place Your Snowboard

According to CoCoRaHS guidelines:

• Place at ground level

• At least 2× the height of your house away from buildings

• Avoid trees, fences, decks, and drift zones

• Use the same location consistently

How to Measure Snowfall Correctly

1. Insert the ruler vertically into the snow.

2. Record to the nearest 0.1 inch (or as close as your ruler allows).

3. Report “Trace” if snow falls but melts on contact.

4. Measure as soon as possible after snowfall ends—do not wait until morning if the storm ended the day before.

CoCoRaHS requires observers to report snowfall once every 24 hours.
During long-duration storms, mid-storm measurements may be taken for Significant Weather Reports.

Important for Big Snowstorms (20"+)

Snow depth may vary widely. Average several measurements across your yard and round to the nearest inch.

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2️⃣ Liquid Equivalent of Snowfall Using the Stratus Gauge

The Stratus Precision Rain Gauge is designed for accurate winter use, but only when prepared correctly.

Before Freezing Weather Arrives

➡️ Remove the funnel and inner cylinder
This prevents cracking and ensures proper freezing precipitation collection.

Snow, sleet, or freezing rain that accumulates in the outer cylinder represents your winter “total precipitation” and must be melted before measuring.

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Two Approved Melting Methods (CoCoRaHS)

🔥 Method 1: Hot Water Bath (MOST accurate)

1. Bring the outer cylinder indoors.

2. Place snow in a saucepan.

3. Melt using hot tap water, not direct heat (prevents evaporation).

4. Pour melted snow into the inner cylinder.

5. Measure to 0.01 inch.

🔥 Method 2: Add Measured Hot Water

1. Measure a known amount of hot water into the inner cylinder.

2. Pour it into the outer cylinder with snow.

3. Swirl until fully melted.

4. Pour back into the inner tube.

5. Your liquid equivalent = Final measurement – initial added water.

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⚠️ Winter Gauge Care Warning

• Never allow snow to melt and refreeze inside the outer cylinder—it may crack the gauge.

• If you’ll be away, store the gauge indoors.

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3️⃣ Core Measurement: The Gold Standard of Winter Data

CoCoRaHS describes the core method as the most precise way to determine snow-water equivalent.

How to Take a Snow Core Sample

1. Place the outer cylinder upside-down on your snowboard.

2. Press straight down until the rim reaches the board surface (cookie cutter technique).

3. Slide a thin board underneath and flip the sample upright.

4. Melt and measure using Method 1 or 2.

5. Enter the result under “Core Precipitation” in CoCoRaHS.

Perform this method after your snowfall depth measurement, since it disturbs the snow surface.

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📚 Additional Resources (CoCoRaHS & NOAA)

CoCoRaHS ‘All About Snow’

Guides, diagrams, winter videos, and measurement tips. Go to the "All About Snow" web site

The Snow Booklet (Colorado State University)

A comprehensive look at snow science and measurement; available for free download.

NOAA / National Weather Service Winter Observer Video

A surprisingly entertaining, highly educational demonstration of official snow-measurement procedures.

YouTube page here.

These are the exact same techniques used by climate researchers, airport weather stations, and hydrology networks.

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🌧️ Why Choose the Stratus Precision Rain Gauge?

The Stratus Precision Rain Gauge, available at FLI Products, is:

• The official gauge of CoCoRaHS

• Built to NOAA and NWS standards

• Accurate for all seasons, including winter

• Trusted by universities, emergency managers, and professional observers

• Made from UV-resistant, heavy-duty polycarbonate for years of service

When accuracy matters, professionals choose Stratus.

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🛒 Ready to Measure Like a Meteorologist?

Equip yourself with the official Stratus Precision Rain Gauge from FLI Products.

👉 Order Today:

🌐 www.fliproducts.com

Your winter measurements support science, water resource management, and better forecasting across the nation.

Interested in becoming an observer?  Click here: cocrahs.org/application.aspx