Measuring Snowfall

• How to measure NEW SNOW with a ruler or yard stick

• Find a location where the snow appears to be of average depth.

• Avoid areas of drifted snow.

• Look for a flat and somewhat open area away from buildings and trees.

• Some trees in the distance may be helpful in breaking the wind and preventing drifting snow.

• Picnic tables, patio decks and car surfaces also make good spots for measuring snow.

• Take around 5 readings and average your measurements, especially if drifting occurred.

• If you measure the snow on the grass, be sure to measure the bottom of the snow and not the base of the ground,

as this will give you an inflated reading.

• Measuring Tips:

• New snowfall is measured to the nearest tenth of an inch

• Example :  T, 0.4, 1.0, 3.6, 13.6

• Total snow depth on the ground is measured to the nearest whole inch

• (Round up if =>0.5. round down if 0.4 or less)

• Examples: flurries=trace  0.4=trace  0.5=1  2.6=3  14.4=14

• Note: If snow has melted as it fell, record as trace of snow.

• How to measure NEW SNOW falling on top of OLD SNOW

• When new snow has fallen on old snow, it is necessary to measure the depth of the new snow along

with the total snow depth.  Here are several ways to do this:

• Using a Clean Snow Board.

• Snow boards are laid on top of the old snow, and are usually made of thin lumber or light material.

• The board should be light enough so they will not sink in the snow...but heavy enough not to blow away.

• They should also be painted white.

• After each observation, boards should be cleaned and placed in a new location.

• Snow boards or measuring areas like decks and patios should be wiped clean of snow every 6 hours

if possible.

• Snow boards are also good for doing snow cores and measuring the liquid of the snow.

• Using a Dirty (Crusty) Snow Board.

• If the old snow has settled and developed a crust, you may be able to insert the snow stick until you

feel a greater resistance.

• Sometimes older snow has taken on a darker color. If so, you can cut a vertical core through the snow

to get the new snow depth.

• Measuring the water content of the snow:

• If you are using a 4” diameter rain gauge, then take the outer cylinder inside with the snowfall in it and let it melt.

• Pour the liquid contents into the calibrated inner cylinder.

• Sometimes the amount of melted liquid inside the outer cylinder may not be representative of the actual precipitation,

especially if there was strong winds and considerable blowing snow.

• You may then want to take a core sample with the outer cylinder.

• ake the outer cylinder and push it straight down into the snow (or your snowboard) and cut out a biscuit of snow.

• Then use a flat surface or cookie sheet to slide under the cylinder so you can lift up the snow contents.

• Then let the contents melt and measure the liquid as done above.

• For those reporting monthly snowfall on the Denver/Boulder Web page, please note the following information:

• Send your monthly snowfall report to scott.entrekin@noaa.gov as close to the first of the month as possible, and

no later than the 15th of the month.

• Snowfall maps are then generated based on CAST and COOP monthly snowfall reports at or around the 15th of each month.

• Seasonal maps are then made based on the season to date snowfall.

• If snowfall is recorded on the last day of the month and snows into the first day of the next month, try and estimate as

close to possible the snowfall up to midnight on the first of the month.

• This means that snowfall should coincide with the calendar date ending at midnight.

• Scott Entrekin at:  303-494-3210 or email at: scott.entrekin@noaa.gov

• Web Site Owner:
• National Weather Service
• Denver/Boulder, CO Weather Forecast Office