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Nicko Brännlund

CAVOK OpusFSX

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Hi!

 

Im living 10 min near the airport of Arlanda outside Stockholm and I fly alot in and out my local airport.

 

I have a question regarding the CAVOK in OpusFSX. As the metar at arlanda shows CAVOK the metar in Opus is also CAVOK and its resulting in a clear and blue sky.

Today the sky here is like, hazed... Looks like a high cloud layer or something, which Opus dont show. Any ideas if there is a fix for this so the 

sky can become near the to the real thing?  

ESSA 101550Z 15011KT CAVOK 06/M01 Q1019 RWY 88 CLEAR AND DRY 51-100 PCT BA GOOD NOSIG=¨

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The weather engine cannot look out of your window it can only go by what is reported in the METARs.

 

Your METAR is saying CAVOK and so is reporting that both the ceiling and visibility is OK at that location.

 

Hence, the LWE has to assume there are no significant clouds below 5000 feet AGL and the surface visibility is at least 9999 (minimum 10km or 6 miles). So it sounds like the LWE is 100% correct with the weather in accordance with the actual reported METAR. Also note the METARs day and time stamp indicates the ACTUAL weather was reported by the Met station at 15:50 Zulu. This report was not automated.

 

I would suggest you set all defaults in all weather dialogs and then adjust your Default Surface Visibility and Cirrus options to match the current conditions. Enable cirrus if you know that there are high level cirrus (they are NOT reported in the METARs so this option its up to you), also do as I do and set the Default Surface Visibilty to say no more than 32km. That will then give you conditions similar to the current observations. You could even set the default to lower.

 

Remember, all the LWE has to go on are the METARs. It will reflect these very accurately but you can tweak the parameters to match your local known conditions. That's what these options are for. The LWE cannot see what you are seeing!

 

Stephen :-)

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Hi Stephen!

 

Thanks for the very quick answer!

 

I fully agree that the technology has not come that far so the weather engine see what our eyes see

 

As from i read from your answer I will try to adjust and try get the weather engine set up at close as it gets!

 

Thanks again for the quick response!

 

Nicko

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If your general conditions are quite hazy with high level cirrus then after setting all defaults you could always enable the cirrus (turn off auto cirrus) and set the Default Surface Visibility to something like 16km.

 

In other words tweak the parameters to match your know hazy conditions and high level cirrus cloud. You could even load a new cirrus cloud texture to match your sky.

 

The LWE can only interpret and interpolate the METARs and its is doing this correctly. Your hazy conditions and cirrus are NOT specified or covered by the METAR reports as they are of minor or no significance to pilots. So its up to you to tweak the Weather Preferences to match your known conditions.

 

Stephen :-)

 

Remember CAVOK just means no significant clouds below 5000 feet AGL and the surface visibility is at least 9999 (minimum 10km or 6 miles).

 

So hazy conditions (visibility > 10km) are not covered by the METAR so you have to create them by tweaking the Default Surface Visibility (the default visibility that is assumed when CAVOK, 9999, or 10SM is reported). A Default Surface Visibility of 16km (10 miles) will be perfect for hazy conditions.

 

Stephen :-)

 

If you are using FSX or P3D without the Volumetric Fog then you might like to try installing the latest beta which produces very realistic visibilities at lower altitude levels whenever there is a reduced surface visibility reported, or even a user specified hazy condition.

 

Stephen :-)

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