Who we are

Andrew Berkley and Peter Spear are paraglider pilots. We like to know what the weather is going to do so we can go flying more often.

What we do

This site visualizes the output of the western run of the High Resolution Deterministic Prediction System (HRDPS), a weather model run by Environment Canada.


Starting in 2013, this site ran very high resolution cloud resolving (400m) WRF models for the Pemberton, Fraser Valley, and Lumby areas nested inside the HRDPS west parent model.

Much of the starting code came from Dr. Jack Glendening's RASP project, but I decided to use a more modern version of WRF and needed to interface it all to the output of the HRDPS model for boundary conditions so I ended up tearing most of the original parts apart. The initial bits for the map viewer came from Paul Scorer, a sailplane pilot in the UK. The windgram code and assorted advice came from TJ Olney, a American paraglider pilot in Washington state. These WRF runs were very informative for understanding the details of wind and Whistler express events around the Pemberton valleys. Unfortunately, it regularly over-predicted the winds in that area and thus resulted in pilots choosing not to fly when it was flyable. I spent time trying to tweak the models and the topography to make it work better but the turn around time was so long to see if it made any difference that I eventually gave up and stopped running it in late 2014. Plus, some of the computers running the model died.

Then we were left with just visualizing the HRDPS output as it seemed to be quite accurate as an indicator for flyability and soarability in our local flying areas.

In May 2018, I began working on trying to visualize the entire Pan-Canadian HRDPS model output as we miss many of the pilots in the east and the north with the current western only output. As a result, I have extended the visualization for at least the entire western HRDPS output, which gives complete wind map coverage of the northern Cariboo and east into Alberta. We were already providing windgrams for those areas, but the wind maps are an important resource as well. This unfortunately takes a reasonable amount of computing power (this all runs on relatively big iron in Amazon EC2), so I am hoping all my viewers consider donating.

Also, if you would like any windgram locations added, just email me.

Planned Changes

August 2018 Add top of lift absolute and actual model terrain to the maps.


7 August 2018 For tomorrows run: fixed surface dewpoint. Added boundary layer depth, average thermal velocity, and cloudbase. Added a parameter description page. 5 August 2018 Added a map of expected top of lift above ground. This is similar to the height the paragliders get drawn on on the windgrams. I'm thinking this indicator is a bit pessimistic. I will get the boundary layer height map on soon which will be the most optimistic. This top of lift indicator ignores cloud suck and ridge lift and uses a model for the shape of thermals and their lift distribution versus altitude. I think we can probably do better. On some days with a slightly inverted layer the top of lift can be very sensitive to ground heating. You have to look at the windgrams to see and judge yourself. I can add a sensitivity map too (ie assume ground temperatures are 0.5C higher or lower), but in the end these are just meant to give you a rough indicator of soarability.

5 July 2018 The old windgram generator failed to run today, so I switched everyone over to the new one. There is now only the new page running. Old bookmarks will work fine, but the map interface will be the new one only. Remember to check the bottom left corner of each windgram to be sure it is the newest one.

3 July 2018 Another oops, windgrams were being generated in the wrong spot, so sorry if it put you off flying. The old versions were fine (and most people link directly to them).

2 July 2018 Oops, some windgrams were not being generated properly. Fixed. Also shrank back the clouds on the two day windgrams and got the time access colored properly and the pressure back to kPa. Show windgrams checkbox is now persistent too (saved in bookmark).

30 June 2018 The tiled map viewer is currently in beta test with all of you as my testers. You can no longer access the old viewer and old windgrams.

10 April 2018 Added a donate button.