Today I installed a new tipping spoon automatic rain gauge that will report real-time rainfall to the website. This is described by the manufacturer, Davis Instruments, as an “incremental improvement” over the previous tipping bucket gauge.
For the most part, our automatic gauge has run very close to our 4″ reference gauge which is 6 ft away & 2 ft lower. However, sometimes — particularly during large rain events — we encounter under reports of approximately 25% to 50%. Discrepancies can appear at any time regardless of wind speed or direction. Many others have reported similar, inexplicable anomalies with the old gauge.
Astute, long-time readers may notice the new “Aerocone” funnel in the picture. Supposedly, this cuts down on rain-induced measurement errors by reducing turbulence where rain is collected.
We’ll see how the new gauge performs. Early side-by-side comparisons from other station owners with reference equipment are encouraging. I’m definitely in the “trust but verify” camp nonetheless.
[UPDATE 5/20/19: The new gauge is performing marvelously so far. This weekend the tipping spoon reported 2.70″ of rain. Our reference gauge caught 2.67″. That’s about a 1% departure. Given the distance & design differences between the two gauges, small variances are normal.]