NZFF

Hi all

I've had this thing in action for a while now but haven't really publicised it.

The weather that FS9 and FSX download (and likewise for any add-ons I've seen) is limited to Auckland, Wellington and Christchurch. These are the only three airports that report around-the-clock METARs and are the only airports acknowledged by the WMS (World Meteorlological Society) as 'true' International airports. If you want to fly to airports outside these locations, you have to either live with their weather or settle for the FS defaults.

A few years ago, I wrote a personal app to try and break this limit, which took NZ Synop weather data from NOAA (originally from Metservice weather stations around the country) and wrote it all into a .WX file for use by FS9. For those who don't know, Synop data is 3-hourly observational data that Metservice stations record. It includes things like wind, temperature, dewpoint, QNH and, in the case of the more spoilt locations, visibility and the height of the lowest detected cloud layer. This data makes up the bulk of what FS classes as 'weather'. The information for NZ airports is mostly out there already, it's just not in a format that FS understands. What my app does is process the latest weather data and write it into a format that fs DOES understand.

It's not a realtime downloader in the same league as Active Sky, although it does include a lot more stations and also shares the ActiveSky phenomenon of smoothing the weather between airports rather than using the SquawkBox style 'sudden change in weather' as you get close to a new station. What it does is creates a .wx file to accompany an existing saved .flt file. If you save a flight in FS, it saves a .flt (the flight) and a .wx (the weather). My app will help you with the second part.



How do you use it?

*Go to FS and save a default flight. Take note of the filename. I call mine 'nzwx'. Close FS. (You only have to do this step once)
Before you fly:
*Go to http://flightsimnz.freehostia.com/ You should see a whole lot of METARs on the screen (if you don't, you've probably come on at just the wrong time. Come back in about 15 mins and try again).
*Click on the link at the bottom of the page called "Download FS9 .WX file"
*Save it to your "My Documents\Flight Simulator Files" folder, and name it the same as the default flight you saved. Note that the extension is important and should always be .WX
*You will be prompted to overwrite the existing file. Say yes.
*Start FS9 and load the flight you just saved.
*Enjoy weather for all of NZ

How does it work?
The script writes a .WX file which is the weather associated with a saved flight on FS. Every flight you save will have a corresponding weather file associated with it. In this case, the .WX file happens to include weather for most significant NZ airports.

What's wrong with just using the online weather from VATSIM?
What if you don't fly online? What if you don't own ActiveSky? I wrote this program years ago because I was getting fed up with the way many weather add-ons for FS worked. They loaded the weather for an airport only once you got close to it which made for some very sudden changes in weather.

This also gives you a 'takeaway weather file' which can be used on machines without a permanent connection.

Why use SYNOP data and why not use METARs?
Because METARs aren't available around the clock. Synop data is.

Does it work with FSX?
I don't know, you tell me! I hope so anyway.
I don't yet know if Microsoft have changed the weather theme/weather file binary format in the latest flight simulator. I'd be keen to hear from FSX users who may have tested this script out.

Bugs? Problems? Limitations?
The biggest limitations are on weather in between airports. The weather for all non-airport places has to be the same for the entire country. So this makes it a bit weak for use in cross country flights, but if enroute weather isn't important then that shouldn't matter.


Just so you can see what this gives, here's the weather you'll get before you use it (using FS's built-in weather downloading)

NZAA NZWN NZCH

And with the autowx from the website:

NZKK NZWR NZAA NZAR NZWP NZTG NZAP NZRO NZGS NZNP NZNR NZPM NZWU NZOH NZPP NZWN NZWS NZNS NZWB NZHK NZKI NZHT NZTU NZCH NZQN NZNV NZDN NZCI

Note, you'll also need to download the 'wxstationlist.BIN' file just the once if you want to get airports like NZKK, NZWR and NZAR into FS.

I've done a bit of borrowing so OH and WU will always have PM's weather, AR and WP always has AA's and RO always has AP's. I could very easily add more.

I'll look forward to some feedback from those who give it a go.

Richard

What is the possibility of a system to keep a record of daily weather, such as a libuary of past weather files? In what time periods does it update, is it constantly the most current weather information? Or is there a cycle system updateing after a certain amount of time? Would it be possible to get weather files for a particular date, if there was some interesting weather that occured on that particular date and time?

This isn't something I would use, but I can see how it could fill a bit of a gap, something I may once have utilised.

Thanks
James

I'm an Activesky user, and not likely to change since it's what I am used to using and what I know best. But, I just wanted to say that this is a pretty incredible thing you've done! Very impressive

Jimmy wrote:

QUOTE (Jimmy @ Dec 30 2007, 11:16 PM) <{POST_SNAPBACK}>

What is the possibility of a system to keep a record of daily weather, such as a libuary of past weather files? In what time periods does it update, is it constantly the most current weather information? Or is there a cycle system updateing after a certain amount of time? Would it be possible to get weather files for a particular date, if there was some interesting weather that occured on that particular date and time?

All good questions. It uses a rather crude mechanism for determining which weather file to use at present. Basically, it's "look for weather now, and work back in time until you find something resembling NZ weather". In other words, you always end up with the latest.

The trouble with getting it to keep past weather files is 1) Storage; and (more importantly) 2) Getting it to actually bring in each weather bulletin without a regular scheduled job. At the moment, if nobody goes to the page, then nothing happens. It only 'does' things if someone downloads it. Both these are a problem since I don't own the web server and can't set automatic jobs to happen, say, every hour, for example.

However, these questions have raised some good ideas. I like in particular the idea of going back through time to get interesting weather that occurred on a particular date.