ASN and FSX wind

[Alex Kulak 30]

It will say wind is at 250 and the runways are 13,4,and 29...29 is what i chose but when i requested a VFR landing fsx gave me the runway to land on RWY4...when they said cleared to land it said wind was 069 @ 14 but ASN said it was 250 at 12KTs.. why isnt fsx reading the right wind data?

[kterz 49]

Hi,

 

where and when? Where exactly did ASN report: "ASN said it was 250 at 12KTs" ? In the metar, ambient monitor, map? Was there a flight plan loaded?

[Alex Kulak 30]

its said that on the conditions page when i entered the ICAO code. (for the surface winds)...its been happening a lot especially at Chicago Midway. the wind direction will say 220@10kts which is straight onto 22L and it gave me 13C and then reported the wind was 136@12Kts but ASN said it was 220@10KTs(happened a couple days ago). ive updated ASN to SP1B but whenever i open up ASN it doesnt say SP1B it just says SP1(doubt that has something to do with it). 

[kterz 49]

Hi,

 

KMDW is an area with densely populated weather stations. From ASN manual, p12:

 

"Your currently loaded flight plan within ASN can affect certain interpolation and weather synthesis behavior. In summary, your flight plan-associated waypoints, stations and airports have precedence in certain situations where multiple weather stations within a “weather cell” can influence the conditions experienced. For this reason, we recommend using flight plans for better accuracy according to your route-specific relevant weather stations."

KMDW is in close proximity to KORD and KIGW, so these stations (if having different weather conditions) will affect the actual depiction you'll get when flying to KMDW. This is a limitation of fsx (and p3d). The weather has to be same in what we call a weather cell. And if more than one stations exist within this cell, the actual weather (and the runway assignment) is the result of interpolation.

You can cross check this in fsx->map, where you can see the winds being different compared to the metar ASN reports. This can be rectified, if you make ASN "aware" of the actual destination. In this case it's considered a priority weather station and the other ones are not taken into account. Similarly ASN considers as priority wx station the closest one, when the aircraft is on the ground. This is the reason in most cases such discrepancies don't come up in your departure field and they only come up in such cases as a VFR flight towards a destination that is unknown to ASN the moment the depiction is decided.

 

Hope this helps

 

[Alex Kulak 30]

yeah this helps for MDW and chicago area airports...i never enter a flightplan into ASN should i?

[kterz 49]

Yes.

 

Even a simple direct "GPS" flight plan that does none of the other stuff will at least make ASN aware of the actual destination and this way you'll avoid such discrepancies. 

[Alex Kulak 30]

well i use the NGX so next time ill fly ill put in a flight plan