How do you judge the wind at 300 feet or 400 feet?
- Thread starter Verdrone
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Wind can alter fairly fast, but usually it does change reasonably predictible.
Around gullies, hills etc it can change a lot faster.
You can use a weather app with various altitude options, in the US I've seen several mentioned here on the forum like UAV Forecast (also in an app).
This works worldwide too.
Other than that, you can look for tall tree movement, usually if there are trees around, they can shelter lower altitude down to ground level, so look up there and see it the tree tops and leaves are showing signs of higher wind before heading up.
Then, test the waters so to speak, gradually ascend to where you want to be paying attention to attitude indicator (the Fly app has this ? Not sure), and watching distance carefully.
Try and fly straight up, or at least into the wind to start as you ascend, this way you can recover from trouble if the wind seems to be too strong to fly higher.
Around gullies, hills etc it can change a lot faster.
You can use a weather app with various altitude options, in the US I've seen several mentioned here on the forum like UAV Forecast (also in an app).
This works worldwide too.
Other than that, you can look for tall tree movement, usually if there are trees around, they can shelter lower altitude down to ground level, so look up there and see it the tree tops and leaves are showing signs of higher wind before heading up.
Then, test the waters so to speak, gradually ascend to where you want to be paying attention to attitude indicator (the Fly app has this ? Not sure), and watching distance carefully.
Try and fly straight up, or at least into the wind to start as you ascend, this way you can recover from trouble if the wind seems to be too strong to fly higher.
UAV Forecast and treetops are the best indicators. I have a Mavic Pro and the DJI App also tells you when the drone is tilted (fighting to keep position). Mine is rated to 9m/s. Not sure what yours can handle. Expect battery drain in marginal conditions and always plan to fly upwind first.
It's common for there to be a gradual increase in wind speed as you 50 or 100 feet and see higher.
The way to prevent wind problems is to think about the wind and how it might affect your flight rather than just flying the drone off into the distance and finding out too late that the return will be difficult.
You should be able to tell what direction the wind is blowing from before launching.
If there is a significant wind, don't fly away with the wind - fly into the wind and see how that affects the drone's speed.
If there is enough wind to make flying against the wind difficult, do not fly downwind.
It might be slow flying upwind, but the return flight will be easy.
FoxhallGH
Well-Known Member
Due to the 'drag' of the surface of the earth, and the foliage etc. on it, you can pretty much guarantee that the wind-speed at ground level is always less than at 400ft above you. So even before you launch, you should be asking yourself if the wind speed is approaching max. allowable at ground level? If it is - then you know you are going to be in trouble as soon as the drone ascends. In that regard, it IS useful to get a hand-held anemometer, just so that you can use it to learn what wind-speed 'looks' like across grass, in trees, across flags etc.
There are some good app's that will show you weather reports of wind speed at altitude too ... 'Ventusky' and 'UAV Forecast' are a couple that you will see mentioned quite often.
There are some good app's that will show you weather reports of wind speed at altitude too ... 'Ventusky' and 'UAV Forecast' are a couple that you will see mentioned quite often.
to be quite honest with you, i personally would not be taking my MM to 300ft to 400ft to begin with, it is so small and at those sort of heights, you would be struggling to see it at any sort of distance, apart from studying how the trees are moving and going up in stages ,i have found a good way to have a safe flight with my drone is to go up to around 20ft ,and hover, and observe and listen to the drone as it fights the wind ,you will get a good idea if it is to windy to fly,one other way to judge wind speed is to look at the clouds and see how fast they move across the sky in spite of the specs of the MM it is more at home being flown lower and nearer than something like a MPP or M2P
bumper
Well-Known Member
As the old man says, look at clouds. They'll give you a good idea of winds aloft and can also hint at the possibility of unstable surface conditions. If their direction is significantly different than surface winds, there is likely a shear line, but at what altitude? If you live near mountains, and winds are 25 knots at ridge level, expect strong turbulence in the lee or downwind (think ocean waves breaking) that can reach the surface - I've had my glider rolled almost inverted, even though I pushed stick forward with full aileron against the roll.
FoxhallGH wrote about slower wind at the surface, or "wind gradient", a commonly encountered phenomena that affects landing aircraft, though it's most often not so abrupt as to overwhelm things if the pilot carries extra speed "for the wife and kids". Wind gradient and shear can occur even over flat unobstructed terrain.
Puffy cumulus are often used by glider pilots as markers. They show the tops of rising air or "thermals" that gliders can use to gain altitude. Circling raptors and other soaring birds "mark" thermals nicely - they do it for a living. Glider pilots head that way for a lift. When a thermal "bubble kicks off" (breaks free of the ground), there will be inrush air from all directions to replace the warmer bubble of rising air. Sometimes there'll be other tell-tail signs, dust devils or light debris rising up. Under such conditions, surface winds can go from calm to extremely strong near instantly and can change direction almost as fast.
FoxhallGH wrote about slower wind at the surface, or "wind gradient", a commonly encountered phenomena that affects landing aircraft, though it's most often not so abrupt as to overwhelm things if the pilot carries extra speed "for the wife and kids". Wind gradient and shear can occur even over flat unobstructed terrain.
Puffy cumulus are often used by glider pilots as markers. They show the tops of rising air or "thermals" that gliders can use to gain altitude. Circling raptors and other soaring birds "mark" thermals nicely - they do it for a living. Glider pilots head that way for a lift. When a thermal "bubble kicks off" (breaks free of the ground), there will be inrush air from all directions to replace the warmer bubble of rising air. Sometimes there'll be other tell-tail signs, dust devils or light debris rising up. Under such conditions, surface winds can go from calm to extremely strong near instantly and can change direction almost as fast.
UAVForecast i find is very very useful. They now have a Wind Profile feature which gives you a basic idea of wind speed as height increases. They use the Wind Gradient equation to determine approximate winds at height. Very helpful. This is a snapshot of my location's wind profile, you can see a 'flyable' wind of 16mph at surface quickly becomes 26+mph at 250ft and beyond. I think that is past your suitable limit for a Mavic Mini's capabilities.
But as others said, taking a Mini up to 400ft is not a wise choice.
But as others said, taking a Mini up to 400ft is not a wise choice.
I know an RC Pilot that uses a helium balloon attached to about 200' of string. He slowly lets out the string and watches the balloon. With marks on the string every 50' or so he knows how high it gets. It doesn't give the wind speed but as soon as the balloon tries to go off in a direction, he knows where the wind changes. Yes, he needs a new balloon every now and then, and he bought balloons and a small helium bottle at the local party store. You can also just release the balloon and watch it go up, as the balloonists do.
Bottom line (to me if I owned a MM) is that DJI states the max wind resistance is 18mph (8m/s). So if you are near that at ground level you are 99% certain that any altitude will have wind speed that is greater than the MM can handle.
If you are in a spot where you have constant wind, you may want to look at a Mavic 2 which can handle wind better.
If you are in a spot where you have constant wind, you may want to look at a Mavic 2 which can handle wind better.
MercHornet
Active Member
Yeah, helium method is not cheap at all.
Those bottles at party supplies or Walmart start at $50
just a tip on what not to get near. Fields of solar panels thow up such thermals that some glider pilots usethem to stay up for hours! They will give most UAVs a merry ride!
SCWxGuy
New Member
I would suggest learning how to read a Skew-T we use in meteorology. A good site to look at good data would be www.twisterdata.com and then click on the "RAP", then use the map to select your location in the United States, then you will be given a Skew-T chart which is basically a splice of the atmosphere from the surface to the top of the troposphere.
From that page you can choose the "show text" option above the Skew-T. This will display as a table that begins at the surface (Highest Pressure Level) and from there will go up in altitude and the corresponding pressure level will drop with height at 25mb increments.
To see the winds at specific heights, look at the HGHT box that will be in Meters, then look at the two boxes labeled DRCT and SKNT which are wind direction (from) in degrees, and speed in knots.
From there just convert to imperial.
*Important*
I do not suggest using any other model than the RAP because its a high-resolution model that updates every single hour and this model is what the NWS Storm Prediction Center uses to base their current mesoanalysis products on.
In the Southeast and Midwest be mindful of the nocturnal Low Level Jet that increases throughout the day just above the surface along with a strong low level jet ahead of any approaching frontal or low pressure system.
Lastly, maybe the biggest piece of advice I can recommend to anyone is reading the local AFD (Area Forecast Discussion) from your local NWS Office that is updated every few hours. To find that, first figure out what NWS Office serves you, then just google your specific "NWS Office" + AFD. For example here in Cola, SC you would google NWS CAE AFD and it will be one of the first 3 or 4 results. Just replace CAE with your local WFO Office. In that, you will find a detailed synopsis of everything you would need to know including a detailed Aviation Discussion that will highlight things like high winds, low level wind shear, and so on.
If you ever have any wx related questions, feel free to shoot me a message.
Hope this is helpful.
- Chris
From that page you can choose the "show text" option above the Skew-T. This will display as a table that begins at the surface (Highest Pressure Level) and from there will go up in altitude and the corresponding pressure level will drop with height at 25mb increments.
To see the winds at specific heights, look at the HGHT box that will be in Meters, then look at the two boxes labeled DRCT and SKNT which are wind direction (from) in degrees, and speed in knots.
From there just convert to imperial.
*Important*
I do not suggest using any other model than the RAP because its a high-resolution model that updates every single hour and this model is what the NWS Storm Prediction Center uses to base their current mesoanalysis products on.
In the Southeast and Midwest be mindful of the nocturnal Low Level Jet that increases throughout the day just above the surface along with a strong low level jet ahead of any approaching frontal or low pressure system.
Lastly, maybe the biggest piece of advice I can recommend to anyone is reading the local AFD (Area Forecast Discussion) from your local NWS Office that is updated every few hours. To find that, first figure out what NWS Office serves you, then just google your specific "NWS Office" + AFD. For example here in Cola, SC you would google NWS CAE AFD and it will be one of the first 3 or 4 results. Just replace CAE with your local WFO Office. In that, you will find a detailed synopsis of everything you would need to know including a detailed Aviation Discussion that will highlight things like high winds, low level wind shear, and so on.
If you ever have any wx related questions, feel free to shoot me a message.
Hope this is helpful.
- Chris
Most states have a "critical infrastructure laws" that prohibit flying within 400ft around power generators and power distribution plants.
Wow this is some really great responses and information, thank you all very much, I actually have a weather station at the house so that will help when I fly from home
Obsidian Sereniti
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I’d also look at flags on flagpoles if you have them. We have lots of industry here so I can always look at smokestacks and see the way the wind is blowing. That gives me a pretty good indicator of the speed and direction of the wind at those heights.
I think the other members gave some AWESOME advice, and thanks for checking before getting up there.
hiflyer201
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It's a guess and they don't have to be from the same direction as on the ground. I would say if you are in doubt...send it straight up a see how it behaves..I'm not talking about launching in a gale or a micro burst. If wind was as big a problem as everyone is making it out to be lately...there wouldn't be a drone left in Texas...would there?
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