Measuring & Recording Snowfall

The following is a summary of guidelines that pertain to measuring snowfall; specifically for north Texas. These procedures include those observers who use a snowboard to measure snowfall. For a more complete description or the full guidelines, you may view this link: NWS Snow Measurement Guidelines. You may also request a DVD on measuring snowfall from the National Weather Service Office in Fort Worth.

NOTE: Snowfall depth is recorded to the nearest tenth of an inch, meaning one decimal place (i.e. 0.5", 8.4", 15.9"). Round to the nearest tenth of an inch in all cases.

Use the below images as a reference for recording snowfall measurements based on your type of form.

B-91 Form

B-91 Precipitation Section

B-92 Form            

   B-92 Precipitation Section

  • Before an anticipated winter weather event or snow 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.

    Standard 8" rain gage with parts labeled

  • Place your snowboard in an unrestricted area. Hopefully the placement location will already have been determined when your station was established, but the location should be away from buildings, trees, and not in an area where drifting snow would result in higher snow depth amounts.

  • There are three measurements you will need to take at your observation time:

1.       Measure and record the water equivalent of snow since your last reading

2.       Measure and record the total snowfall depth

3.       Measure and record the new snowfall amount since your last reading

 

       Arrow To measure and record the water equivalent of snow: (There are two ways)

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" under the "24-hour Amounts" heading under the "Precipitation" section (Box #1 above); just as you would record regular rainfall. 

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

 

          Arrow To measure and record the total snowfall depth:

1. Using the snow stick, measure the depth of the snow on your snowboard.
2. Write the total in the column titled "Snow, ice pellets, hail, ice on ground" under the "At Ob" heading under the "Precipitation" section (Box #3).

 

          Arrow  To measure and record the new snowfall amount since your last reading:

1. Using the snow stick, measure the depth of the snow on your snowboard.
2a. If there was no snow on the ground the day before, then your measured snow depth will be the same value as your total snow depth. Skip to step number 3.
2b. If there was snow on the ground the day before, subtract the total depth that you just measured from the depth of snow that was on the ground the day before (this would be the total snow depth that you recorded the day before). This value will be your new snowfall amount since your last reading. For example, if on the 16th you measure 2" of snow on your snowboard and on the previous day (the 15th), you had measured 0.5", then 2" - 0.5" = 1.5" and this would be your new daily snowfall. You would record 1.5" as described in Step #3.
3. Write the total in the column titled "Snow, ice pellets, hail" under the "24-hour Amounts" heading under the "Precipitation" section (Box #2)

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