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Guest dajackman

Is there a website that offers winds aloft info?

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I would love to try to factor more realistic winds aloft for my flights since the METAR info does not really account for anything but ground winds.Thanks.Chris Catalano

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You can get FDs (winds aloft forecasts) from the following site:http://www.awc-kc.noaa.gov/awc/awc-fd.htmlAlternatively, you could also use soundings from the following page to derive actual winds aloft (not forecasts):http://weather.uwyo.edu/upperair/sounding.html(Note that both of these sites are primarily limited to US data. If there is a website out there with worldwide FDs or soundings, I'd love to know where it is myself.)- David Sandberginfomsig.jpg

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How does one input this data into FLY? Is it available in FLYII? I only use FLY2k where there seems to be only sliders for ground winds

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Sorry - winds aloft are only supported by Fly II. (And in Fly II the only way to use them is to input them yourself through the UI ... AFAICT there's no SDK access to the winds aloft data structures, so a winds aloft add-on is not likely to be forthcoming.)- David Sandberg[br][br]infomsig.jpg

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Great!....only - how do you interpret what these numbers mean? For example - at KJFK: (The altitudes are not primted in this examle - they did not copy & paste for some reason - bit I know how to see which column I am looking for) JFK 2506 9900+15 2805+10 3205+04 3109-08 3115-19 341434 351744 361656What would each number mean, & why do some have +2 extensions, while others do not? Thanks! Looks like great potential. Also, do you use these info pages yourself, & if so, do you have to manually keep updating the winds aloft along your flight route, or can you do it all at once - or will infometar keep reverting back to its original steeings every time you fly past a METAR station? Thanks a bunch!Sincerely, Chris

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Last answer first: all bets are off if you manually enter winds aloft after loading METARs. I honestly don't know how well that will work, and I've not done it myself (personally I'm not very happy with the whole winds aloft implementation in the sim ... it's rather fiddly even just to get them all set the way you want). But I will say that if it works at all it probably will continue working throughout a flight, as the winds aloft settings are global and should be entirely separate from the METAR settings.Also I want to point out that InfoMETAR isn't doing a thing at this point ... it is out of the picture once you've saved METARs to disk for use in Fly! What Fly! does with them at that point is beyond my control. The whole point of InfoMETAR is to tweak the METARs before Fly! sees them, in such a way that Fly! is more likely to produce accurate results with them.As far as updating the winds aloft during a flight, you'll probably note that winds aloft forecasts generally cover much broader areas than METARs, and vary much less dramatically for the most part. If you want to try to update them throughout a flight I suppose you can, but I'd probably just set and forget them myself.Now, as to how to read FDs ... that's a pretty big question, but here are the basics for your needs:The first four digits at each altitude are all you need for winds aloft (ascending from left to right, using MSL up through the 12K feet entry, and pressure altitude above that). The first two are the direction the wind is blowing FROM, in degrees (dropping the last zero, so "34" is 340 degrees). The third and fourth digits are the speed in knots. You don't need the last two digits (sometimes preceded by a plus or minus sign), as that is the forecast temperature.Some special cases: light and variable winds are always written as "9900" (as in the 6000 ft. report for JFK in your example). Also, if the first digit of the direction is 5 or more, subtract 5 from that digit and then add 100 knots to the wind speed. Another one: altitudes close enough to ground level for the winds to be affected by surface friction are omitted. For example, if the elevation of a particular station is 2000 ft., the 3000 ft. entry will almost certainly be omitted from the FD for that station.If you need to know more than this you can probably find information on FDs via a web search.- David Sandberginfomsig.jpg

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Hi Chris,All wind directions in a winds aloft forecast are true direction, so you have to add or subtract the magnetic variation found on your sectional to get the magnetic direction. Winds given in METAR observations are also in true direction, btw.The column headings are missing from this, but ...JFK 2506 9900+15 2805+10 3205+04 3109-08 3115-19 341434 351744 361656JFK is the reporting station3000' - 250 degrees true at 6 knots, (temperature is omitted since it close to the surface)6000' - 9900 means light and variable, temp is 15 degrees C.9000' - 280 true at 5 knots, 10 degrees C12000' - 320 at 5 knots, 4 degrees C18000' - 310 at 9 knots, -8 degrees C24000' - 310 at 15 knots, -19 degrees CAll temps above 24000' are negative and the minus sign is omitted.30000' - 340 at 14 knots, -34 degrees C34000' - 350 at 17, -44 degrees39000' - 360 at 16, -56 degreesIf the wind speed is higher than 99 knots, 50 is added to the direction. So if the winds at 39000' were 360 at 116 knots with a temp of -56, it would be encoded as 861656.Hope that helps.John

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David and John,Thanks for sharing this info. I have also wondered how to read the winds aloft data. You just clarified it for me very nicely.Allen

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http://weather.noaa.gov/fax/nwsfax.shtmlthis is where I get all my prelim info before doing any X-country flights, prior to getting my flight breif. Main ones I use are the Radar Summary (Shows rain and t-storm movements), Wx Depiction (movement and frontal areas), and the surface analysis charts, mainly the prog charts to get an idea on the outlook. They download in .tif format so just pop them open in a graphics program and print them out.c ya :-waveBart flyhelp@zoomtown.comhttp://bartsflyplace.tripod.com/pics/ryans...ight/flight.gif http://bartsflyplace.tripod.com/bart_logo3.jpg

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Here's a site that shows winds aloft in a graphical format. Much easier to interpret and see the "big picture" instead of reading a string of numbers off a teletype. This site has a lot of cool aviation weather stuff that doesn't rely on 1960's technology (limited to ASCII characters).http://adds.aviationweather.noaa.gov/Dan

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Hi David,There is SDK support for winds aloft data via the APISetWindsAloft and APIGetWindsAloft entrypoints. Perhaps InfoMetar can be modified to collect and store the winds aloft data? I can write a simple DLL that can read the data and set winds aloft when Fly! II starts. Cheers, Tony

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I wasn't aware of those functions ... I don't remember seeing them in the SDK documentation, anyway. Have you by ay chance tested them to see if they actually work as one would expect?If they do, I could certainly put together something to get the forecasts with InfoMETAR and then pass it off to an SDK module to bring the data into Fly II (either one that you write or one I write myself ... if these functions really work, it seems like it should be relatively trivial).Actually I'm now starting to have all sorts of ideas here. Shame on you. :)- David Sandberg[br][br]infomsig.jpg

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Hi David,What can I say? I'm a trouble-maker! :-)I'll whip up a simple test tonight that'll verify the usability of those API functions. I'll let you know. Cheers, Tony

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Hi David,Created a simple DLL that changes the winds aloft according to some rather unscientific and unprincipled random nonsense that works like a charm! Here's a bit of the interesting code (in particular, note the APISetWindsAloft() method invocation--pretty easy, no?)...

void setWindsAloft(){/*	WEATHER_WINDS_ALOFT_3000 = 0,	WEATHER_WINDS_ALOFT_6000 = 1,	WEATHER_WINDS_ALOFT_9000 = 2,	WEATHER_WINDS_ALOFT_12000 = 3,	WEATHER_WINDS_ALOFT_15000 = 4,	WEATHER_WINDS_ALOFT_18000 = 5,	WEATHER_WINDS_ALOFT_FL18 = WEATHER_WINDS_ALOFT_18000,	WEATHER_WINDS_ALOFT_21000 = 6,	WEATHER_WINDS_ALOFT_FL21 = WEATHER_WINDS_ALOFT_21000,	WEATHER_WINDS_ALOFT_24000 = 7,	WEATHER_WINDS_ALOFT_FL24 = WEATHER_WINDS_ALOFT_24000,	WEATHER_WINDS_ALOFT_27000 = 8,	WEATHER_WINDS_ALOFT_FL27 = WEATHER_WINDS_ALOFT_27000,	WEATHER_WINDS_ALOFT_30000 = 9,	WEATHER_WINDS_ALOFT_FL30 = WEATHER_WINDS_ALOFT_30000,	WEATHER_WINDS_ALOFT_33000 = 10,	WEATHER_WINDS_ALOFT_FL33 = WEATHER_WINDS_ALOFT_33000,	WEATHER_WINDS_ALOFT_36000 = 11,	WEATHER_WINDS_ALOFT_FL36 = WEATHER_WINDS_ALOFT_36000,	WEATHER_WINDS_ALOFT_39000 = 12,	WEATHER_WINDS_ALOFT_FL39 = WEATHER_WINDS_ALOFT_39000,	WEATHER_WINDS_ALOFT_42000 = 13,	WEATHER_WINDS_ALOFT_FL42 = WEATHER_WINDS_ALOFT_42000,	WEATHER_WINDS_ALOFT_60000 = 14,	WEATHER_WINDS_ALOFT_FL60 = WEATHER_WINDS_ALOFT_60000,	WEATHER_WINDS_ALOFT_MAX*/	SWindsAloft wa&l;WEATHER_WINDS_ALOFT_MAX&r;;	int heading = rand() % 360;		int delta&l;&r; = { 180, 90, 270, 90, 270, 20, 20, 340, 340, 20, 			20, 340, 340, 10, 10, 10, 10, 350, 350, 350, 			350, 10, 10, 10, 10, 350, 350, 350, 350 };	for( int i = 0; i < WEATHER_WINDS_ALOFT_MAX; ++i )	{		heading = ( heading + delta&l; rand() % sizeof(delta) &r; ) % 360;		wa&l;i&r;.windHeading = heading;		int speed = rand() % 30;		if( rand() % 100 < ( i + 4 ) * 3 )			speed += rand() % 70;		wa&l;i&r;.windSpeed = speed;		wa&l;i&r;.gustSpeed = speed + rand() % 30;		wa&l;i&r;.windFluctuates = ( rand() % 100 < 30 ) ? char( true ) : char( false );	}	APISetWindsAloft( wa );}

I'll have my gnomes contact your gnomes and maybe we can get this into the Fly! II mainstream. Maybe we should even do some networking, find our key strengths, and go to market in a focused client centered, technology driven paradigm.Sorry. I won't do that again... :-)Cheers, Tony

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Cool ... that is certainly encouraging. I had no idea that anything like this had actually made it into the SDK.I must add that I'm a bit puzzled by your implementation. :)- David Sandberginfomsig.jpg

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Puzzled?! Oh come now, it's perfectly obvious... :-lolHere's what my code does (in english):First choose an arbitrary initial wind heading.Now for each wind layer, change the direction of the wind heading randomly by anthing from 10 degrees up to 180 degrees. The da[] table provides a simple probability table--there is more likelihood of changing only +/-10 to 20 degrees that there is to change 90 or 270 degrees.For each wind layer, choose an initial wind speed in the range of 0 to 30 knots. Then, arbitrarily add a whole bunch of wind just to make things interesting. The conditional makes it more likely that there is higher wind at higher altitudes.Finally, add an arbitrary amount of gust and arbitrarily make the winds variable. It works and makes for some very entertaining wind patterns! :-)Cheers, Tony

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It was the odd sequencing of the values in the delta array that had me scratching my head, but now I can see why you would have chosen to order them in that way. Personally I tend to do ramped calculations like that with pure math, in order so there is some chance of any and all direction changes ... like 40 degrees, for example, a direction change with altitude that can never occur with this code.Edit: another thing just occurred to me ... is there some reason why you didn't allow any possibility of the wind direction not changing at all with a given bump in altitude? Maybe put a couple of zero elements at the tail end of delta?- David Sandberginfomsig.jpg

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Hi David,I know you're not being overly critical, but let me just say that I banged this code out in about 20 minutes--start to finish. I had given some thought to what I would do to test the API function and this is what I came up with. Anything more realistic would have taken me a bit more time. Besides, what we really want is to use the real data. So, my code is just a proof point and nothing more. :-)Cheers, Tony

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That's fair ... sorry to have been nit-picking. If anything, I hope you'll take my suggestions as a compliment, since in 20 minutes work you seem to have come rather close to as good a randomized winds aloft function as anyone could ask for.- David Sandberg[br][br]infomsig.jpg

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Now, as to how to read FDsWhat does FD stand for anyway?Lastly - Also I want to point out that InfoMETAR isn't doing a thing at this point ... it is out of the picture once you've saved METARs to disk for use in Fly! What Fly! does with them at that point is beyond my control. The whole point of InfoMETAR is to tweak the METARs before Fly! sees them, in such a way that Fly! is more likely to produce accurate results with them.But, the file you load must have different wind speeds & directions at different stages of the flight - no? I mean, in any given flight, you are likely to cross several Metar stations, each with different surface wind directions & speeds, so therefore, even though the file is already pre-loaded at the outset of the flight - don't the wind speeds & directions get changed & updated to reflect the current station your are passing. These varying numbers were loaded as part of the original file. So if I change the winds aloft, won't these numbers be overridden or reverted back to reflect whatever was in the original file when I pass each succesive station? In short, even though the file is loaded only once & it is in place for the entire route as a static file, each station has its own numbers & weather elements (that's why you can go from clear skies to precipitation for example). So, if I change the winds, won't they change back to the "real numbers" encoded in the loaded pre-existing file once I pass each new station? Hope I am making sense. :-)Thanks. Chris

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Chris,The METAR file produced by InfoMETAR and thereafter loaded by Fly! contains surface observations only, including surface winds. Again, the important word is surface. Internally in Fly! the data structures that contain surface data (including winds) appear to be entirely distinct from the one containing winds aloft layers. Fly! continuously and dynamically interpolates between all loaded surface observations to produce weather conditions, but presumably surface winds extend to all altitudes only if no winds aloft are specified. Winds aloft information is global in nature and not interpolated. I'm fairly certain there is no interaction between surface observations and winds aloft settings, or at least the sort of interaction you are evidently concerned about.In short, I don't expect this to be a problem.I have no idea what FD stands for, and was surprised to find that it wasn't specified as anything other than "Winds and Temperatures Aloft Forecasts (FDs)" even in any of the weather and/or aeronautical volumes I have here. Maybe someone else here can chime in with the answer if they know?- David Sandberginfomsig.jpg

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