The Good News

Several of you have been asking what is happening to the snow data you are entering. It appeared as though it was entered and just disappeared. That was not the case of course. When you entered it, it was going into the database but there was previously no web page to display the information. Well now there is … sorta.

In the Reports section, there is now a new options for New Snow. I want to do more with it but just having this available has pointed out the next topic.

The Bad News

Now that there is a way to look at the data, it has become very obvious that we still need a LOT of training on how to measure and enter snow data. All of you that have experienced measuring snow already know it is more complex, confusing, and time consuming than just measuring precipitation in the form of rain. But that certainly doesn’t mean we can't learn how to do it right. Please don’t get discouraged that it is a little more of a challenge. There really isn’t much snow data available for Nebraska so once we start getting it right, this will become very valuable and interesting.

First, I see that I need to do a lot of work on the quality control phase for the data entry form. As you look over the data, you will see all sorts of input data formats in the three new snow fields. In fact, I see there are even several entries for snow during the months of May through September. I would guess that most of those early entries are not valid so I’ll have to go through and edit out what are obviously incorrect entries and try to make assumptions on those where I can make a good reasonable guess as to what they should be.

I also need to add programming to the web page to make sure only valid entries go into the database in the future. Don’t be surprised if you had entered something like '1/2', '4 ??', or '1 inch' earlier but later that no longer works. I’ll try to put checks into the programming to stop entry errors like this before they get into the database.

Another item needed is to improve the reports for snow and develop mapping capabilities to provide a better visual presentation but I can’t do that until we can make sure all the data going into the database is in the correct format.

We also all need better training on how to measure snow and what is supposed to go into each field on the form. I recently obtained a DVD from the High Plains Regional Climate Center entitled “Measuring Snow” and it really does a nice job of showing how all of this should be done. They explain some of the problems you will run into and what to do about them. I wish everyone would have the opportunity to view this but I have made copies and just today sent them out to all of the Regional Coordinators. At least now when you have questions, we will be able to answer more intelligently ourselves.

I will also try to send out further instructions on the measuring process soon. Now that most of us have been through a snowfall or two, we at least have a better idea of what problems may arise.

Be sure to re-read the Help File on Measuring Snow at: http://dnrdata.dnr.ne.gov/NeRAIN/docs/snow.asp but here is a brief synopsis of what should go in each field. In the near future, I’ll add more detail.

Total Precipitation: By now everyone should have their funnel and inner tube removed and inside because those will break in freezing rain. The snow that is trapped in the outer tube should be melted down and then poured through the funnel into the inner tube. At this point, it is just like the rain you have always been measuring and is entered in hundredths (0.23 for example).

New Snow: This can be measured several times a day during a storm and totaled up if you have the opportunity but just enter the information once at your normal 7:00 AM time slot. The reason for measuring more often is snow melts and settles so the more often you measure, the more likely you are to measure the maximum amount. Just measure this with a ruler (ideally on a snowboard or other hard surface) and record only to the nearest half inch (4.5 for example). You may have to measure in several places and average the results when you have blowing and drifting snow. This should just be the snow that has accumulated in the last 24-hour period.

Total Depth of Snow: The purpose of this field is to measure the total snow that is still on the ground from not only the previous 24 hours but also all previous snowfalls. Just measure the snow with your ruler at various locations so you can get representative samples around your area and enter the average. Yes, you may have none in some locations and five foot drifts in others but just give it your best shot at an average converted to inches (12 inches per foot) and enter to the nearest half inch. You may end up with a number like 29.5 to represent two feet five and one half inch.

Core Precipitation: This is just another way to measure the total precipitation but don’t be surprised to get significantly different results due to blowing and drifting snow. Turn your outer tube upside down and press it through the snow onto the snowboard. Then holding the outer tube and the bottom of the snowboard, turn it right side up so the snow is trapped in the outer tube. Now melt this down just like you do for the Total Precipitation and enter the results in hundredths (0.37 for example).

As mentioned earlier, more information can be found at: http://dnrdata.dnr.ne.gov/NeRAIN/docs/snow.asp. While measuring and entering snow data does take a bit more effort, the results will certainly be useful for the citizens of Nebraska and your efforts are appreciated.

Thanks again for volunteering for NeRAIN.

Rich Kern
Nebraska Department of Natural Resources
301 Centennial Mall South
P.O. Box 94676
Lincoln, NE 68509-4676
(402) 471-3948
rkern@dnr.ne.gov