In a December 30, 2008 email from Nolan Doesken, National Director of CoCoRaHS he requested:
Default snowfall. Up until now, the snowfall (new snow) defaulted to
0.0 on the "Daily precipitation" entry from. We did this to try to
simplify your reportings since it is usually not snowing. But on the
urging of some of you, we changed that default to NA (which means "not
available"). We made this change because some volunteers don't feel
comfortable or don't choose to measure and report snow but were leaving
the 0.0 default in their reports. This made our snowfall maps very
confusing and difficult to analyze with many false zeros dotting the
maps in the middle of snowy areas.
But now we need your help. If you had rain or freezing rain but no snow
to report, the computer no longer inserts a 0.0" for your daily snowfall
total. So if you want us to know FOR SURE that it did not snow at your
location, then please type over the NA and insert a 0.0" This is
especially important if you are close to the rain-snow line. If you had
precipitation but no snow, please type in 0.0" for your new snow amount.
If you report 0.00 precipitation the computer automatically inserts 0.0"
Very few people in our area are doing this.