Prepar3D v5 Weather Problems

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Opus Software
Posts: 33
Joined: Tue Apr 17, 2012 1:08 pm

Prepar3D v5 Weather Problems

Postby Opus Software » Thu Apr 16, 2020 9:39 am


I have encountered two major problems with P3Dv5 weather updates. The first is the inability of the sim to adhere to any upper wind direction targets (or even the surface wind direction on occasions). The second is severe sky/cloud flickers during weather station creation and weather station updates. Details of my tests and observations are described below.

Prepar3D v5 Weather Tests

All tests conducted using the global METAR

27016KT 9999 SCT030 04/01 Q1018

Two methods of weather injection were tested.

Dynamic Weather Theme Updates


PDK Updates using IWeatherSystemV430 Functions

The weather theme or PDK IWeatherSystemV430 weather is injected on the ground at EGNX (East Midlands, UK).

In both cases, the ambient wind direction will move smoothly towards the injected 270 direction. On occasions however, the wind direction will never manage to reach it's target surface wind direction and keeps getting reset back to a lower value. For example, it may increase from 138, reach 173, and then get reset back to 138 again. Continuing in this endless cycle. Other occasions it would endlessly cycle between a wind direction of 168 and 203 degrees, again never achieving its target surface wind direction of 270 degrees.

This problem can occur irrespective of whether the 'Enhanced Atmospherics (Beta)' option is enabled or disabled. However, with Enhanced Atmospherics enabled there are additional problems (sky/cloud flicker) when the PDK functions are used to create new met stations and inject weather into new or existing met stations.

The ATIS at EGNX also reflects this problem by reporting an incorrect surface wind of 144/16. If however, the wind direction manages to reach and settle on 270 then the ATIS reports the correct 270/16.

Of course it would be much better if when the aircraft is not airborne the surface wind direction should snap to the required target value and not smoothly move toward the new target, The smooth wind direction change is only required once airborne.

After the weather injection the METAR is correct at EGKK (Gatwick) 204km (110 miles) away provided the surface wind is allowed to settle on its target.

General Problem When Airborne (Both Theme and PDK Weather updates)

P3Dv5 fails to meet any upper wind direction targets !

The ambient wind direction fails to achieve the targeted direction during climb or an upward Slew.
The ambient wind direction appears to be anchored to the surface wind direction.
Both ambient wind speed and ambient temperature meet their targeted values.

This problem occurs irrespective of what method is used to inject the weather.
The target wind directions (wind layers) are all correct when examined in Custom mode.

Enhanced Atmospherics (Beta)

In addition to the above points I have noticed the following problem with the Enhanced Atmospherics (Beta) mode.

Enhanced Atmospherics (Beta) - Enabled

There is severe sky/cloud flicker each time a new 'distant' weather station is created and also each time weather is injected into either a new or an existing (Prepar3D) 'distant' weather station. By 'distant' I mean at any distance from the aircraft even 80+ miles away. The same sky/cloud flicker is visible even if the IWeatherSystemV430 'SetMetarData' function is used exclusively in place of the separate IWeatherSystemV430 PDK functions, the flicker occurs with either zero or non-zero delays specified in the 'SetMetarData' function.

Of course, the severe sky/cloud flicker makes the new Enhanced Atmospherics (Beta) mode totally unusable.

Enhanced Atmospherics (Beta) - Disabled

No sky/cloud flicker just as in P3Dv4.5.


User avatar
Opus Software
Posts: 33
Joined: Tue Apr 17, 2012 1:08 pm

Re: Prepar3D v5 Weather Problems

Postby Opus Software » Fri Apr 17, 2020 7:44 am

Weather Theme Null Zone

You may also like to consider a previous suggestion of mine. That is to allow a Null Zone to be specified (in miles or kilometres) when submitting a theme using the Set Theme SimConnect or PDK functions.

The null zone would prevent the weather (specifically clouds) from changing in the area surrounding the aircraft, allowing only changes to the distant weather and cloud formations.

These are changes intended to improve realism in the sim with respect to weather depiction and weather injection(eliminating sudden wind and cloud changes) as users conduct flights over long distances. Allowing this for theme injection would provide the most efficient method for injecting weather into the sim with blanket coverage over an extended region.


Posts: 3
Joined: Sat Nov 10, 2012 6:44 pm

Re: Prepar3D v5 Weather Problems

Postby rdtv » Sun Apr 19, 2020 8:07 pm

+1 on this and also the the null zone proposal, would really improve weather depiction

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