Topic: New Davis Vantage Pro 2 Install

[Weatherjunkie]

I have waited a long time to obtain one of these. I upgraded from a La Crosse Station that I've had for about 6 years. I decided to install the Davis Vantage Pro 2 on roof for now. Wanted to try it out there first and see how the readings compare with other stations. I know this install makes maintenance a pain so maybe relocating the ISS unit closer to the ground in the spring. In the one picture the mast appears to be leaning but it must be the angle of the shot because it is plumb and level. The top of the mast is almost 30ft in the air, 29ft 8" to be exact. I wasn't too crazy about adding a taller "lightning rod" to the top of my house but the previous anemometer for the La Crosse was located there, just on a shorter mast. I was smart enough to ground it though, with 6 gauge stranded wire connected to a 4 ft grounding rod driven into the ground. Still wonder if grounding it was a good thing or not. Seems to be a lot of opinions out there about it. I figured if it was to take a hit it would give it a nice path to ground and maybe not damage the house or the VP2. 

[ValentineWeather]

Congratulations, 
As long as its temporary. Rain and temperature data won't be reliable. Like you mentioned ISS needs to be at ground 5'-6' and anemometer mounted on roof. One of the reasons many use the wireless anemometer setup. The 40' anemometer wire is restricting but can be spliced and extended if needed.

[CW2274]

Ya, like Randy said, the ISS has to come off the roof. And just so there's no confusion, he meant to say anemometer, not altimeter.

[alexstaar]

Not bad! I second the advice to move the ISS closer to the ground, or at least away from the roof/shingles. I envy you anemometer setup, I wish I had no trees around to have better exposure for my anemometer...

[ValentineWeather]

Ya, like Randy said, the ISS has to come off the roof. And just so there's no confusion, he meant to say anemometer, not altimeter.

I'm half asleep today.

[Scalphunter]

All #6 wire does is bleed the static electric off of you annometer. With the amperage in lighting both the wire and unit would vaporate.

John

[Mtn_man]

I have my ISS mounted on a mast on the roof, as I really don't have any other options due to trees, as I live on a steep heavily wooded lot on the side of the mountain.  Same reason I have not added solar or UV sensors, as it has a limited view of the sky.  I'm just happy the sun hits the solar panel enough to keep the battery up.

If anything the anemometer readings are likely low simply because my house is completely surrounded by big trees.  Even the wind direction is probably skewed because of being on the side of a mountain.  The ISS is 7 feet above the roof peak, and the anemometer is approx 15 feet above roof peak.

I worried about the temp aspect, but the temp is always within 0.2 or 0.3 degrees (F) of an accurate thermometer that is about 5 feet off the ground.

Best I can do, and I'm not cutting 100+ year old oaks down for a better site. 

Downside, maintenance is a PIA, but have a wire screen funnel I improvised in the rain bucket which has reduced clogs significantly.

[Weatherjunkie]

Thanks for all the comments and advice. The ISS is not directly above the roof surface but rotated just off the roof to help with the surface heat effecting the temps. Its a little tough to see in photos, but I know its better to locate the ISS closer to the ground. Everything I read recommends 5-6 ft off the ground, but I have seen many people mounting them on the roof using the roof mount. I do live in "suburbia" so it did play a factor in the decision to get it up away from trees and other houses that might have an effect on it. It is keeping up with close readings with surrounding stations including the near by airport readings. I will definitely spend the winter rethinking the placement of the ISS but leave the anemometer up on the mast. Maybe extending the mast to a recommended 33 feet and and possibly adding a roof cam. I really think its neat being able to see different reading from stations with the live cam view of it.

[ValentineWeather]

One thing that might help change your mind in a hurry is go outside at night (Must be still very little wind) preferably predawn with another thermometer. Wouldn't surprise me if it wasn't 3+ degrees warmer above the roof. We measure surface air temperature at 5-6' not 15-20.

[Weatherjunkie]

Well first let me state again, I do agree with lowering the ISS down to the recommended height, but I compared the temp readings throughout today, starting at 5am, against several surrounding stations including the airport. Now I have no idea how or where these stations are mounted or located exactly, but surprisingly I was actually a either right on with them in temp or a degree or two cooler than them. I used the airport as a base line. Figured it was the most accurate and is located only a few miles SE of me. I matched it several times throughout the day in readings but mostly about a degree cooler or at times two degrees cooler. Just wanted to share my findings but not to start an argument about it because I really do want to relocate it and make my station as true as I can.

[CW2274]

Well first let me state again, I do agree with lowering the ISS down to the recommended height, but I compared the temp readings throughout today, starting at 5am, against several surrounding stations including the airport. Now I have no idea how or where these stations are mounted or located exactly, but surprisingly I was actually a either right on with them in temp or a degree or two cooler than them. I used the airport as a base line. Figured it was the most accurate and is located only a few miles SE of me. I matched it several times throughout the day in readings but mostly about a degree cooler or at times two degrees cooler. Just wanted to share my findings but not to start an argument about it because

I really do want to relocate it and make my station as true as I can.

Then you're one of us.