Incorrect barometric pressure in S.Africa?
#1
When I connect FSXWX, the barometric pressure at Maun (FBMN) Botswana when reset "B" changes from

29.83 at 3120ft airport ground level (already reset without FSXWX)
to
27.99 at 4330ft airport ground level (reset again)

-Below 18000ft ATC keeps telling me and AI traffic that there alititude is wrong, reseting "B" won't change it to the ATCs pressue, its stuck at 27.99.
-When descending for an approach ATC asks me and AI to fly at an altitude pattern which is very close to the ground.
-Clouds are often at ground level.

This happens in many other southern african countries aswell, Europe is fine.

I've had similar problems with other weather generators in africa aswell, normally temperature is lower as if FSX is reporting its actually below sea level so may be its an FSX bug.

Without any realtime weather generators, theres no problems.

Using latest FSUIPC, FSX Gold, Windows 7 64bit, UAC disabled.

Thanks
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#2
Hi,
I experience the same phenomenon in FBMN.
Reset pressure with B on the apron, and the altitude starts rising ( means pressure starts sinking)
However...... I just tried again, starting at fbsk. All ok.
Then slewing to fbmn. All ok!! Route fbsk - fbmn in FSXWX.

Strange..

Gert57
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#3
Just tried again.
All ok, and interpolated metar in fsxwx corresponds nicely with metar from FBMN!!
Good job and thanks again for a nice programme!!

Gert57

PS Is it possible to donate something to help in the server upkeep??
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#4
Maybe the problem is down to the actual metar, sometimes metars aren't as detailed in some areas, with less information on clouds, temp etc which would likely effect all weather generators.
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#5
Well, I'm not so sure about that.
Because it only affects the pressure, not the clouds and temp.
I will do some more tests in Botswana.
I tried yesterday eveing in the southern Cape, and all was well.
Will report back with the results in more detail.
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#6
Did a flight from FBMN to FB34.
Metar FBMN in screen fsxwx reprted as 1014 mb.
BUT FBMN gave interpolated pressure 1001 mb at FBMN.
When flying I constantly pushed B, pressure steadily went down to 948mB in a 12 min period, and then stayed at that level.
After 20 mins arrived at FB34 and pressed reload wx.
Metar gave again 1014 mb at FBMN, but fsxwx injected 27.61 Hg = 935mB
I think something is wrong in south Africa / Botswana region.
Maybe admin can shed some light on whats happening...

Gert57
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#7
Checked yesterday evening. Flight in Tasmania from YMLT:
injected weather exactly as metar,
NO decreasing barometric pressure as in Botswana.
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#8
Thanks for all these information!
I am currently quite busy with other things but I will dig into this potential error as soon as possible.
Regards
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#9
fsxwx Wrote:Thanks for all these information!
I am currently quite busy with other things but I will dig into this potential error as soon as possible.

cheers, great program
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#10
I have the same problem in the flight between VNKT and VHHH
In VNKT, the fsxwx injected a much lower pressure, say the fsxwx meter said 1014hpa but what injected into FSX was only 9xx or lower.
Throughout the flight the pressure is still very low. After transition alt, I set the altimeter back to 1013hpa and I kept having 4000ft different between indicated alt and the actual alt which is very great.

One thing I noted is that both VNKT and FBMN are located at high altitude (VNKT: ~4400ft; FBMN: ~3100ft)

Hope you will figure the bug asap. Thx
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#11
It looks like the problem is actually the barometer gauges in FSX, their range is too limited and so wont adjust or reset low enough at high altitude airports. Many forums have reported the same problem even without FSXWX and some people have made there own gauges by overriding the kohlsmans settings, calculating airport elevation with QFE etc.

eg my typical problem is at Maun, ATC says pressure 27.72 and my baro wont go lower than 27.99 at Maun, so my altitude is higher.

I dont think the pressures displayed in FSXWX vs FSX weather dialog box are relevant as theres always going to be slight delays in updating information when comparing them.
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#12
I don't think thats the case toggernet.
I tried it at KJAC, field alt 6400 ft.
pressure by fsxwx exactly as found on the internet. No change in pressure during a flight.Pressing B with fsxwx swithced on gave the exact correct qnh
What I dont understand is that atc at Maun gives a pressure of 2772. It seems that is QFE, not QNH.
FSX works with qnh, otherwise the altimeter can't give the altitude above sea level.
Or, you have still the same problem that FSXWX bleeds the qnh down to low levels in southern Africa.
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#13
I think or at least I hope that I have found the error in the post-processing of the GRIB data.
So, anyone who was affected by the problem is invited to try it again. There is no need for a new FSXWX client because the error is corrected in the data itself (but only from now on and not in the historic data!).
Regards
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#14
Yeah, seems ok now.

Cheers.
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#15
Can confirm.
Did some flights around Maun. Air pressure doesn't drop off anymore.
Thanks for fixing!!

Gert57
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