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First I want to mention that I just got a call from the High Plains
Climate Center. They have been following the growth of NeRAIN on the site
and want to add our data to their network. The Omaha National Weather
Service contacted me last week for the same reason. Just as hoped and
planned, NeRAIN is quickly becoming a very important source of information
for weather forecasting and modeling. They were delighted that we planned
to continue throughout the year rather than just during the growing
season. I’ll be working with them in the near future to develop ways to
share our information with them.
Finally, the dreaded SNOW discussion
I have to confess that when I first started measuring precip for NeRAIN
last April, I was fully intending to just pack it up for the winter once
that white stuff started dropping from the skies. However, after having
been doing this every morning for 200 days straight, I find I need my
NeRAIN fix every morning at 7:00 AM. After all, how bad can it be to get
out there when it is still dark, cold, snowy, windy, slippery and just
generally uncomfortable? In addition, it requires more data that is more
complex to measure. Oops, I think I just talked myself out of it …
NAAAAAH. Seriously, there are special challenges to measuring snow but
nothing us dedicated NeRAIN volunteers can’t handle.
This discussion is going to be a lot shorter than what I had first
envisioned. I looked at the NeRAIN website to re-read what is available
under the “help” section and there is an item titled “How to Measure Snow”
That was actually written by Nolan Doesken from the Community
Collaborative Rain and Hail Study (CoCoRaHS) in Colorado and he very
literally wrote the book on this subject so I certainly can’t do any
better than that. Be sure to check that out at:
http://dnrdata.dnr.ne.gov/NeRAIN/docs/snow.asp and that will describe
most of what you need to know about this. I will add just a few comments
as they pertain to entering your data.
You use the same form you have been for Daily Precip except now there are
three more fields to enter. In the website documentation, it describes
“Measuring Precipitation – the water content of snow.” Following these
steps will get you the information for our field called “Total
Precipitation” which is where you have been entering your rainfall
measurements.
The next item is called “New Snow Amount” and this is the amount of new
snow in the past 24 hours. You try to measure the maximum amounts before
melting and settling occur so you may want to check the snow amounts more
frequently than just at 7:00 AM. You will still just enter the data at
7:00 so will need to record the intermediate readings on paper. Reading
the website description will make this more clear.
Next is “Total Depth of Snow on Ground” and here you just measure what is
on the ground at the time of the measurement to the nearest half inch.
Since the depth will vary, you may have to take more than one reading and
average them.
Finally, the “Core Precipitation” is very similar to the “Total
Precipitation” described above except this is measured by using your
four-inch outer tube and using it like a cookie cutter to grab the snow.
Then you take it inside to melt and measure as above.
There is a specific order to doing all this so do be sure to read all of
the instructions at: http://dnrdata.dnr.ne.gov/NeRAIN/docs/snow.asp
I’m a rookie at this too so we will all be learning together but if you
have any questions, fire them to me and I’ll see if I can find the
answers. I’m supposed to be getting a DVD from the High Plains Climate
Center that goes through the process visually so that should help.
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
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