Canadian Weather Stations

[Guest jhaley]

Hello, Love the program, still enjoying build 147 haven't toyed with the betas. I have noticed that at some airports the magnetic variation is showing positive instead of negative. The airports observed included Regina, Saskatchewan and Cranbrook, B.C. - which by the way I highly recommend a try for all pilots, the area is a beautiful approach. There have been others too, I noticed in the activesky folder a listing of all airports, confirmed these airports are showing positive values, made the change to the list and saved it. No biggy really, but the resulting wind report is off slightly. Again, love the program. John HaleyThunder BayCanada

[JSkorna 137]

Hi John,Thanks for that. So is it that the values are correct. but the positive or negative portion is wrong. Can you list the codes of the ones you have noticed and/or changed? Thanks again!Hope this helps,JimActiveSky Supporthttp://www.hifisim.com/images/as2004proudsupporter.jpg

[Guest jhaley]

That's correct, values are right on the mark, just in some select spots minuses are missing in front of the value therefore turning it into a positive value. There have been a handful, maybe 6 or 8 airports where I have seen this over the last 2 or so months of flying. I'll check back in my log and see if I can verify the locations for you. I recently finished 50 U.S. states and spotted them here and there. Now I'm back in Canada. Most recently, the airports I have noticed are:CYXC - Cranbrook BCCYQR - Regina, SK Is there an e-mail I can send them to directly as opposed to posting here? Either way. Thanks Jim. John Haley

[Guest jhaley]

Here's a couple of more from some checks dating back a few flights. KPQI - should be plus 20, presently showing minus 19. KBDR - should be plus 15, presently showing minus 14.7KILG - should be plus 11, presently showing minus 11.9I'll keep my eye open as I continue on my trek here and there. John

[Guest jhaley]

Prince George CYXS, showing plus 21. Should be minus 21. ThanksJohn.

[Guest Ken Greenwood]

hmmm - not sure I'm with you on this one John, although I just landed Saskatoon and was wondering why my winds were not as forecast. METAR winds were 340/10 - was getting closer to 040 -- flew the VOR/DME appch to 33 and was a tad surprised by the crosswindas to the magnetic variation - the line of 0 variation runs roughly just west of Thunder Bay (CYQT). From looking at the AS airports database - all stations east of that (those with a westerly variation) have a negative value. Those west of that (easterly variation) should have a positive value in the database.CYHZ Halifax has a variation of 20W - so you would add 20 to the true winds to get magneticCYXE Saskatoon has a variation of 15E - so you would subtract 15 from the true winds to get magneticNot sure how all this interfaces with AS2004 wind reporting - but from my look at the airport database they are entered correctly

[Guest jhaley]

Appreciate hearing from you. I think we'll need more input but I believe the problem with the winds you have experienced through AS in Saskatoon are created exactly because of the information in the database. Here's what I mean. Your forecast winds showed 340/10 but you were getting 40 at 10 because in the database for Saskatoon, the variation is mis-reported at 13.7 when it should read -13.7. This is not exactly precise, I would have felt better if you said your winds were 347 at 10, but I think we're close enough to prove the point. I agree, the values should be plus values east of 0 (zero) variation and negative values west of the line. As you mention, Halifax is showing a 20W variation (+20), but in the database the airport is listed at -19.9I wasn't totally sure about any of this until I started noticing that the winds were not entirely accurate, especially on trips in Canada. I believe this explains the difference you experienced when landing in Saskatoon. To convert from TC to MC, Westerly Variations must be ADDED to TC to get MC (MC = TC + VAR. (MC = 45

[JSkorna 137]

Hi AllFYI, I spent about 2 hours doing the following, not that I mind, and I learned of some new web-pages so all is good!So that anyone can duplicate my results:1. Used the following page for airport data:http://www.pakaviation.com/PVA/Library/World_Airport_Data/2. Used the following page for magnetic declination:http://www.ngdc.noaa.gov/seg/geomag/jsp/Declination.jsp3. Looked up every ICAO you all gave me, found the actual MV today and the value in AS. (It's in the weather station list, not the airport list.)So here we go:Station Actual Today AS ValueCYXC 17E 17.8CYQR 11E 11.8KPQI 19W -19.3KBDR 14W -14KILG 11W -11.9CYXS 20E 21.8CYHZ 19W -19.9CYXE 13E 13.7My conclusion after this investigation: For every station given to me the value and the sign are correct in the AS database.Hope this helps,JimActiveSky Supporthttp://www.hifisim.com/images/as2004proudsupporter.jpg

[quantumleap 1]

JSkorna writes:>My conclusion after this investigation: For every station>given to me the value and the sign are correct in the AS>database.If I read this correctly, what you are simply saying is that in its weather station list AS represents westerly variation as a negative value and easterly variation as a positive value.As for the previous posting pointing out that winds seem to be out by the variation value, could this be because you have to remember that METAR wind values are given in degrees true not degrees magnetic.This therefore means that if the METAR at Halifax Intl (CYHZ) says winds are 32007KT, this means that they are from 320 degrees true at 7 knots i.e. 339 degrees magnetic once you factor in the 19 degrees west variation.

[JSkorna 137]

Hi,Well, not really what I am saying. The first post talks about the possibility that some of the data signs are reversed. The list of possible stations grew to a point and I had some extra time that I could check things out. So I did and posted my findings.If the question at hand would have been what is the format for the data that I could have answered right away: west variation is a negative value and east a positive value, as you stated! Same thing with lat. and long. North is positive, south is negative, west is negative and east is positive in the data fields.We also need to keep in mind that FS04 displays wind direction using magnetic values. Sometime this can throw things out of wack!Hope this helps,JimActiveSky Supporthttp://www.hifisim.com/images/as2004proudsupporter.jpg