How to defend our weather stations from large hail...

[Andrea Griffa]

Hi all
I was trying to find a solution to protect my Davis Vue while chasing but I'm not really finding a definitive solution to protect it from large hail.

Anyone has got any idea to build something like a hail net to defend our weather stations from large hail?
Thanks a lot!

Andrea

 

[Jeff Duda]

One possible solution: if you're driving around with expensive weather stations on your roof, don't drive into hail.

 

[Zach Young]

The problem with most (maybe all) methods one might use to protect instruments from hail is that in the process of protecting them, you'd be ruining the station's ability to collect accurate data. Especially wind data.

 

[Andrea Griffa]

One possible solution: if you're driving around with expensive weather stations on your roof, don't drive into hail.

Thanks Jeff, this is a perfect idea

Joke apart, my demand comes from the observation that sometimes it's impossibile to rule out the hail in a stormchasing day, sometimes because of poor road options, sometimes because of chasing errors or supercell types (it could happen that the rain free base is not so free, especially from hail ).
However, it's true that every kind of net could invalidate your weather data but I actually don't need a perfect wind speed or a perfect rain rate while chasing. I overall need a good dew and a wind speed (I don't need a perfect wind speed to chase). It could be good to realize a net that would not be an absolute drawback.

 

[Jeff Duda]

To be honest, other than a bulky metal/wire mesh screen box over the instruments, I can't really think of any existing product that would serve the purpose.

 

[cdcollura]

Good day all,

I was thinking a sonic anemometer with an extra "hard hat" dome atop it so that the wind will still not get disrupted. Maybe a plexiglass disk above it.

Above: Hail "hard hat" protecting delicate (solar panel) instruments.

For temperature / other sensors, those can be put in vented PVC, as in the image below...

A rain guage can be a problem, but I am thinking the plastic funnel over it can be "remade" with sheet metal or some stronger material, just thinking.

 

[Robert Forry]

I just purchased my Davies in October so next season will be my first with it in the Plaines (and here). I plan to deploy it on a mag mount and will remove it at the onset of severe hail, which begs the question, what size will the unit tolerate? Thanks

 

[Jeff Duda]

I just purchased my Davies in October so next season will be my first with it in the Plaines (and here). I plan to deploy it on a mag mount and will remove it at the onset of severe hail, which begs the question, what size will the unit tolerate? Thanks

Just curious how you plan to remove the anemometer at the onset of severe hail. Do you mean you'll get out of the car and take it off yourself when the hail gets too big? I fear you may find that to be more of a pain than it will be worth, unless you have a way of quickly pulling it down through the roof without getting out of your vehicle.

 

[Joshua Nall]

Ha... "more of a pain than it will be worth", no pun intended? yeah you will probably want to remove it when you think you will no longer be able to tolerate the size of the hail. Seriously, that should be in time to keep the unit from seeing damage.

 

[Robert Forry]

I guess I need to think that one through some more. Obviously, I don't want to see the investment ruined, and staying out of the way of it (severe hail) is the best bet - but not always avoidable.

 

[Joshua Nall]

I probably wouldn't worry about it too much if you do try to stay out of the hail and then if you do get caught you can jump out and grab it. Hail is sort of a funny thing. You may get into big hail 15 times and it never take a hit. But then again you could have one big stone fly from a meso on your first chase next year and take out your unit, when you thought you were safe. I’ve stood out in quarter size at times and have it hit all around and never hit me. I’ve been sitting in really big hail before and never even had one hit my truck. Obviously its a chance type of thing. Welcome to the site, I saw you posted on the meet and greet and read with interest.

 

[bjewett]

One possible solution: if you're driving around with expensive weather stations on your roof, don't drive into hail.

Not the most helpful suggestion ...

 

[JL Gacke]

I understand your situation.

Top pic - I originally kept a Davis station sans rain bucket and with the anemometer able to fold up to clear the Jeep's slip stream as best I could.
After a couple years I decided against the anemometer because you had to take into account a moving vehicle and cross winds with that older model.

The middle pic shows a fun hail event that nearly destroyed the station.

Bottom pic is how I've been running a few years and yes, the shroud around the sensor housing does affect the readings while stopped (though not much), but it's quite accurate within usually a percent humidity or degree TDP/mean temp.

I can live with that just fine and I'm not always repairing a busted up housing, especially since I always end up in hail.
The housing does allow for a moderate airflow front to back and while driving is usually in pretty good agreement with real-time data from outside sources.

Hope this helps.

 

[Quinton Kirsch]

There's not much you can do to really prevent hail damage. Even the best instruments used by NSSL and researchers at universities succumb to damage. Best thing you can do like Jeff said is avoid it when possible or worst case have the parts that most easily break readily available for replacement in the field. Redundancy is key in that situation. An alternative to this could be learning the threshold of hail size your station can survive and react accordingly with the environment. However, there are other caveats to this. Despite the hail only being a certain size that your station might survive, you may also have to account for the speed of the vehicle and how that effects the impact to the station itself. All really just depends on your budget and how involved you want to be.

Cheers