Following is a list of Internet sites that I have found useful in determining what will be happening to the weather, from a glider pilot’s point of view. The order in which you search these sites and whether all are useful at the time depends on whether you are doing a last minute check up or taking a longer term view.
Remember that we will be lucky to get an accurate prediction 5 days in advance so anything beyond that can only be taken as a guide.
There are three models that we use in the US.
The GFS (Global Forecast System) model - This is a world model run by NOAA and has the longest term view that you can get but is generally too coarse for good local predictions. The computer model is run 4 times per day and forecasts up to 16 days in advance. It uses either a 35 or 70 kilometre grid square.
The NAM (North American Mesoscale Model) model - This model is run by the NCEP (National Center for Environmental Prediction) for short term weather forecasting. The model is run four times a day out to 84 hrs on a 12Km grid size.
The RUC (Rapid Update Cycle) model – This model also run by NCEP assimilates recent observations to provide high frequency updates of current conditions. It runs every hour and predicts out to 18 hr. I believe it uses a 13Km grid size.
I find the NAM the most useful as I am generally looking a day or two ahead, but the most accurate on the day will be the RUC.
1) I think the easiest to use site that produces a gliding forecast from each of these three models is XCSkies
This requires a subscription which is either US$39.95/year; US $29.95/six months; US$4.95/month.
The forecast data is given as contours over a map of the area of interest, or the program will provide a point forecast over a period of time or a forecast along a certain route of choice. It will also allow the Tephi to be plotted for a point selected from the map. One can also select wind barbs to be shown at various chosen heights. I now prefer this to the old Dr Jack site that I have used previously. The facilities are quite comprehensive and easy to select.
2) For a quick look at the weather charts
3) For a view of the radar and satellite data
4) For looking at the long range picture of how things are changing over the whole of North America then the following site produces an easy to navigate set of charts.
5) The following site has an interesting interpretation showing cloud cover at three levels. This can be reached by scrolling down the left bar; the option is second from the bottom.
6) For ridge winds a good site to get the meteograms showing the wind with height is.
A similar plot can created in XCSkies.
7) A sanity check to see that other forecasters agree is always a good idea.
For the Toronto area I use
For State College and other US locations