tomdiving - 15-5-2017 at 05:38 AM
hey,
recently picked up a skywatch meteos 1 wind meter.
i'm trying to find a correlation between what i actually am reading, and what the weather channel has forecast at a particular time.
my WC reading comes from an airport 12 miles west of me. i do know that wind can change considerably over just a couple of miles. my next closest
reading would be from another airport 15 miles SE of me.
WC says, for instance, 13mph yesterday. i took an average with the meter over a 30 minute time frame and it was 5.5mph.
when the meter indicated 11 to 12 mph briefly, my little 2m pansh flux was dragging me all over the place.
when the meter showed 5-6mph, it was flying along rather nicely.
anybody using this meter? find the same huge discrepancies? is there a way to recalibrate the unit?
i've downloaded the sparse manual and see a "CAL" button, but there is nothing written about it as a system reset.
or, is the wind actually less strong normally than i thought it was?
thanks for any info/opinions!
tom
Bladerunner - 15-5-2017 at 06:36 AM
Wind speed often changes a lot as you go up in level.
Don't get all worried about numbers and work more on feeling the wind speed. Personally I get a lot more valuable information from a flag or wind
sock.
Randy - 15-5-2017 at 09:45 AM
Lots of factors come into play. Is the field you are in very large? Surrounded by trees or buildings, hills, etc? Airports have lots of concrete
and asphalt, so they can build up heat, which helps wind to flow. Also, most airports read the wind from 30 feet (or 10 M?) above ground, where there
would be some more wind, though not enough to differ from 5-6 though.
I've seen lots of times when I have been at the lake and wind is say 5-10, while the airport says something like 12-20. Other times I see lots of
whitecaps and wind seems to be 15+, and airport is saying 7-9.
tomdiving - 15-5-2017 at 10:15 AM
this particular field is about 1/2 of a normal city block. the wind was NNE which is my most clear path there, at the bottom of the rectangular area.
yes, trees and a school building, which I try to take into account. I was measuring about 4 ft. off of the ground.
did not think about the airport heights or pavement.
in that flight, the treetops and ground wind appeared similar, going only by what I saw and felt. when the trees took a gust, so did the grass.
I was really trying to find... say... a relatively constant 3mph difference so that I'd know what was really happening out there when it shows 10,
15, whatever.
one day was predicted to be at 8mph, my average was 4.4. another said 10, I got 2.4. so nothing solid yet, but I do intend to try this is more open
areas when I can.
tom
jimbocz - 15-5-2017 at 11:10 AM
I'm with Bladerunner, pay the most attention to what you see and feel. I'd bet your windmeter will be less accurate than your observations. There's
a scale called the Beufort scale, that focuses on what you can observe. Most forecasts will also be able to display that as the unit for wind speed.
Then you can start to get an idea of the relation between forecasts and actual wind.
Perhaps you could try to find a weather site that's more accurate. My favorite is https://www.windguru.cz/ , although your mileage may vary if you are somewhere other than the UK. Mostly it's free but you can subscribe for
increased accuracy. Even though it's usually pretty accurate, i only use it to plan which spot I am going to go to based on the predicted direction,
or if I am going to stay home because there is no wind at all forecast. Once I am at the flying site, I pay attention to what I can see and feel
rather than any forecast.
Good Luck!
tomdiving - 15-5-2017 at 01:10 PM
I'm in the US. southeast Michigan.
I'm familiar with the beaufort scale, it's also a choice on the meter, along with others.
first I wanted mph numbers to gauge how things look, but i'll also switch it to beaufort for the same reason.
rather than just going by "leaves move," "branches move," etc, I want to see HOW MUCH they move to be regarded for that part of the scale.
with leaves on the limbs, and then without leaves in the winter.
I am happy with knowing what wind it takes to launch various kites, and how useful they'll fly, I merely wanted hard numbers to back it up.
tom
markite - 15-5-2017 at 01:42 PM
your numbers on your meter may be fairly accurate for where you are holding it. I'm the north side of lake Erie and this time of year is early surf
season and squeezing in last days of bugging until fall. Many forecasts locations are inland but it's very different from what you would get looking
at marine forecasts just a few miles away. Then depending on how clear and warm it is and wind direction you might find the trees doing sit up within
a 1/4 mile of the beach and then dead calm at the beach because of doming. Then at the beach the is zero wind at ground level and maybe 30-40 feet up
but the very top leaves of trees will be moving - coax a kite up through zero wind only to have it climb well above tree tops and find yourself lifted
off the ground.
Standing on the beach with a bit of breeze it will feel like more in areas because the wind accelerates up a slope or funnels through an area. One of
the funniest things happens all the time - there is 1-2 mph and everyone is sitting and waiting for the wind to come up and you'll feel a puff of
maybe 3-4mph (still way below minimum needed) and someone learning to surf will jump up with a wind meter holding their arm out right, out left, up
high double check the readings, out again confirming the readings - we usually yell out to quite blocking the wind with that thing - all in good fun
but I understand your wanting to learn, most of us did it too. Living by the great lakes (or many inland locations) it'll be hard to nail down the
numbers, we usually check multiple forecast models, web sites and locations to get an overall sense of what is happening and then go with a gut
feeling as well as bring everything because you just never know for sure.
Bladerunner - 15-5-2017 at 05:21 PM
I get what you are hoping to do. I have found that where I live the real wind is usually what is predicted in KPH if I change that to MPH. That is my
location though. I really count on my site for direction and a hint as to what the wind will do.
Look at the wind like water flowing down a stream. Pretty hard to quantify the flow from one part of the stream to another.
I suspect you will find more wind up high than at ground level at your location? How long are your lines? If I am correct you should be able to feel
what I am saying. To feel more wind up top and less as you bring it down the edge.
tomdiving - 19-5-2017 at 08:37 AM
bladerunner - i'll try and switch the meter settings and see what that may give me. good idea there. I had heard in the past to gauge airflow as water
flow. I had not thought about that for a while, though. it will now be incorporated constantly.
my flux lines were 20m. I made extensions last year for my rush pros to get up out of the bottom of the wind bowl I'm in. I have a 30m set, but I
didn't think that I'd have to go to that yet. I had figured that I would need to put them on in the summer months, but it looks like I won't be
waiting that long now.
since I'm just playing with the kites, and not doing anything traction related, I'm wondering how useful longer lines may actually be. if I have to
get above the tree levels to fly, I'm not going to be able to use much of a window to play around in. still, I guess, any flying is better than no
flying.
markite - trees doing situps is a fantastic mental image! very funny! never heard of doming before, so I learned something with that.
in addition to the weather channel info, I look at windalert and weatherunderground. as luck may have it, there's a local site less than 2 miles from
my house. as MY particular luck may have it, it's useless. it's always late with windspeed. the actual location was the very first one of many in my
county. when it was installed, though, (so long ago) the area was a field with 2 intersecting dirt roads and clear as far as you could see.
it's next to a winding creek. all of the tiny trees along the creek then are now monsters, the area has built up into a city. if the speed is
actually showing currently, I can only hope for a strong SW wind in order to have a usable reading. in the winter it's ok when the leaves are down.
ran across this today, which should give me many more options - http://torontowindsurfingclub.com/resources/twc-news/201-whe...
thank you, gentlemen, for your replies.
tom