Monday, February 1, 2016

Our Farms Historic Rainfall

I have recently put 18 years of rainfall data in a spreadsheet ( 1998 - 2015).
---14.67"  is what it turns out to be our average yearly rainfall over the years, --with 9 years at or above, and 10 years at or below. (one point was counted in both, above/below).  The graph indicates our Ewan/St.John farm is in the 13-16" rainfall zone, instead of the 15-17" as most maps have us.  (Is this a real change from 1940-1970's)???
---Our lowest rainfall total was in 2002 with 10.31 inches.
---Our highest rainfall total was in 2006 with 18.35 inches
---Two years, 2015 & 2003, June received a trace, or no rain.  June is a benchmark for us.  Good rains normally translate to good yields, little rain translates to not so good yields.
---Six years, July received no rain.
---Five years, August had a trace, or no rain.
---June with more than 1.5 inches were (2014, 2013, 2012, 2010, 2005 ).  These were great crop years, or, had the potential had not other climatic forces become involved, --for example, Nov. of 2013 had an event where high winds accompanied by a sudden drop in temperature severely damaged the 2014 winter wheat through out the Palouse.  Most people had patches of good wheat, but the general yield was down approximately 25-30%,
---Our ULD system that incorporates the Shelbourne header and the CrossSlot drill is an attempt to lessen dependency on good June rains by reducing moisture loss through runoff and evaporation.  2014 was a great year to test the theory, but alas, the June 12 freeze ruined the potential of all our crops, both winter and spring.  All surviving crops were delayed in maturity, and the unusually high heat of July & August caused further damage.  The CrossSlot did all it was advertised to do, and the crops got a great start, but circumstances beyond our, or it's control lowered yields.
---Our rainfall tends to cycle up for three years, then, down for three years.  (+/- ?)
---If that pattern holds we may rise through the average precipitation line in 2016, and give us, depending on the June rains, a good crop, both winter and spring.
---The charts below use the same data, but the lines attempt to show three different aspects:  June rain,  total rain received, average monthly rain received.



















Conclusions (?):  When I started this post three days ago, the goal was to state a few obvious points that stuck out in the 18 years of data, but as I got more into it, the more intriguing it became.  I'm not going into any more detail than what's been stated above; other than to say that,  I'm extremely glad we chose to upgrade to a ULD system.  In the short time (4 years), I can visually see it is paying off.  We are, and always have been in climate change.  What that means for the future is argued daily.  I'm convinced the Shelbourne and CrossSlot is the best option for meeting the challenges in the future.








4 comments:

  1. I handle the weather data for ARS at the Pendleton Station. For 1940 to 1970 we averaged 17.29 and 1998-2015 16.03. Our long term 1930-2015 is 16.38. Our experience with maps has been that the older maps didn't have a lot of input data or take terrain into account. The new NOAA maps based on the PRISM model from Oregon State University have a tendency at least in our immediate area to over estimate at elevated locations in the basin. For us the area between the station and Helix is mapped as an inch or two higher than we have encountered in our experiments. If all your measurements are from a manual gage that is best. If you have gone to an automated station as many have, the tipping buckets have their own deficiencies. Always appreciate seeing a good long term dataset. Thanks for sharing it.

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    1. Thank you for this information. I'm familiar with the Pendleton Station and have a particular interest in the long term farm practice plots. There are only a couple of areas in the US with similar studies, going back to 1939. While I was serving on the STEEP advisory committee and the funding was going away, it was my priority that those plots were funded. Fortunately, most of the other committee members had the same priority. Those plots are a treasure. Also, I use a physical gauge. I also have a remote electronic station I verify with. It normally is ≈+0.10 per month compared to the physical. To keep it from going nuts with wind I had to isolate the bottom dump area. I could accumulate 5" an hour on a cloudless day.

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    1. You bet. Hopefully we can keep those plots going. Sounds like you have good quality control on your precipitation measurements. We have some remote sites that just have tipping buckets which always raises some questions during long term snow (rare for us), and extreme events with tip to tip rates greater than a couple inches an hour, but generally they are pretty good. Thanks for the blog, It's helpful for those of us that don't have the knowledge to run a whole operation, but benefit from following along.

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