National Weather Service Forecast Office

Measuring & Recording Freezing Precipitation

This section focuses on the correct way to measure and record freezing precipitation. In north Texas, freezing precipitation mainly consists of freezing rain, sleet, ice pellets, and snow grains. However, this can also include measuring snow (on the occasions that it occurs in north Texas) that collects in your rain gauge using the method described below. The following procedure does not include the use of a snowboard.

Before an anticipated winter weather event, remove the plastic funnel and inner tube from the rain gauge. This will allow the outer can to catch precipitation of all types and sizes without clogging the funnel.
At your observation time, you will be measuring and recording the water equivalent of freezing precipitation. there are two ways to measure the water equivalent of freezing precipitation:

1. Bring the outer can inside.

2a. Wait for the freezing precipitation to melt (if it’s not snowing, sleeting, etc... outside)

3a. Put the plastic funnel back over the inner tube and pour the contents of the outer can into the plastic tube. Measure this total as you would a rainfall event with the rain gauge stick. This measurement is your total water equivalent of freezing precipitation.

4a. Record the total on your B-91 or B-92 form, under the column titled "Rain, Melted Snow, etc"; just as you would record regular rainfall.

5a. Dump out all the water and return the outer can back to its location outdoors.

OR...

2b. Fill part of the inner tube with hot water and measure that amount using the rain gauge stick.

3b. Pour the hot water into the outer can causing the freezing precipitation to melt. Slosh the water around, if needed, to melt all the freezing precipitation but be careful not to slosh any of the water out.

4b. Put the plastic funnel back over the inner tube and pour the contents of the outer can into the plastic tube. Measure this total as you would a rainfall event with the rain gauge stick.

5b. Subtract the amount of hot water that you poured in (Step 2b) from the total amount of water you just measured (Step 4b) to get the total water equivalent of freezing precipitation.

6b. Record the total on your B-91 or B-92 form, under the column titled "Rain, Melted Snow, etc"; just as you would record regular rainfall.

7b. Dump out all the water and return the outer can back to its location outdoors.