Howdy Steve and WeatherCat gardeners
I think the proposed additions make sense as I understand it right now. Are you going to include this in both ET calculations, or just the VP2 one?
I had been thinking only to include the VP-2 ET calculation because it is much more accurate and I can't imagine someone would buy the soil sensors without already having the radiation sensor.
Here's my comparison of ET calculated with both the B-C and VP2 formula since November.
Thanks for sharing your data. It is similar to what I've seen here in wintertime. The Blaney?Criddle estimate only works well when evapotranspiration is driven mostly by direct solar heating that also is causing the observed temperatures. When the winds kick up or there is higher humidity, the Blaney?Criddle estimate started to go off. Also, when solar radiation is weaker, it tends to overestimate the evapotranspiration. As reported, it is best used only in arid areas like the American southwest. Still, I hoped it would be a guide for folks who can't afford a Davis station and radiation sensor.
What I've found it good for so far is a great early rain warning! It jumps right up if there's a mist or very light rain that might take some time to register on the tipping bucket mechanism of the ISS. A guy on the WXforum (where I've cross-posted my review) says he uses it in conjunction with the temp and dew point to predict frost and fog.
I've complained about the slow response to misty, foggy condition by most weather stations. Even if the rain bucket doesn't tip, the moisture on the ground could be a serious safety hazard. Too bad Davis didn't adapt this sensor into something that could be added to the VP-2 to detect this sort of mist without all the overhead of soil and leaf sensors.
I was wondering about adding one more entry to my proposed spreadsheet output: maximum soil moisture. The case I was wondering about is what happens if you water the area during the day. In that case, you might want to make sure that the soil reached the target moisture content.
So that's where my thinking is on this right now.
Cheers, Edouard