Hello Vernon, 

 

what kterz is saying in his explanation is very clear. 

 

PFPX just uses raw data, it does not analyze it and interpolate it. So, for example, in PFPX you'll see aloft wind numbers for a datum of flight levels: FL300, FL340, FL380, etc.These numbers are received from weather stations, and divided into fixed layers, or flight levels. 

 

ASN parses these numbers, and by interpolation and smoothing calculates what wind you'll find at layers not included in the raw data but included in your flight plan. Moreover, ASN goes a step further. PFPX only looks at the METAR, which is the present weather reported by a weather station, ASN parses the TAF, which is a forecast. and based on the TAF parsing is able to tell you what conditions you will get at your ETA. 

 

In other words, PFPX uses raw data, ASN gets the same data, and via parsing that numbers and using the TAF goes a step further. and tells you what you will find. 

 

As the two methods are of course different, you'll get different numbers between PFPX and ASN reports. After all, PFPX is a flight planner, and ASN is a weather engine. 

 

Hope this clears this out a bit, 

 

Enrico 

You say parsing the taf what do you mean?

 

I forgot to clear up your question. Parsing means to analyze and resolve a sentence into component parts, and give a description of a sentence. 

 

So, ASN reads the TAF, and parses it, analyzes it and through this, it outputs the weather conditions for your waypoints at the ETA. 

 

Enrico

Hi enrico so basically ASN is constantly updating as PFPX is just a fix at that time of the weather stations?

Yep, it keeps updating the weather by downloading METAR and TAF reports, this is very important for long haul flights, like oceanic routes. The initial report you see off ASN is of course a snapshot at the precise time you download it, but during the flight the weather may and will change, it is not static, of course, 

 

 

Enrico

Okay thanks alot i'll keep on reading!

Is the TAF do with the weather at the airport? And METAR at a weather statiom other than an airport?

Confused with interlayer and interpolation

 

Aaaaaaahhhhh