Welcome to Quick Tour for XC Maps. There are just 3 simple steps to start using XC Maps:

Step 1. Select a Forecast Model
Simply put, there are several widely used forecast models which are the culmination of years of science and validation. Of these, the GFS (Global Forecast System) is the only freely available global model. We currently use this to 'seed' our global soaring predictions. There are two other models used extensively for North America: the NAM (North American Mesoscale Model) and RUC (Rapid Update Cycle). These regional models differ in several fundamental approaches, so we have incorporated both into our applications for North America. You can select the model maps to use at the top left of the application.

Step 2. Select a Time
Don't let the time feature confuse you. It's quite simple. When you create a user, select an appropriate time offset from GMT (Greenwich Mean Time) for your local location. If the time is set correctly on your computer, that offset value will be used unless you indicate otherwise. Once your user is setup with a proper offset, all times displayed above the map are in your local time, in 24 hour format. For example, Utah is -6 hours from GMT. Once this is selected, all times reflect as local, so 12 is noon, 15 is 3PM, 18 is 6PM, and so on. You can select a different offset anytime you like. Times highlighted in blue indicate there are maps available for that time, and yellow indicates the selected time.

Step 3. Select a Map Layer
The map layers are 2-dimensional imagery of useful soaring parameters. Layers are categorized into related parameters, and include: Thermal, Cloud/Weather, Wind/Turbulence, and Surface. Click on one of the layers for the model and forecast time you have selected and watch that layer load on the map. To read more about the details of each parameter, click on the icon to the right of each map layer section. Many of the variables will be quite intuitive to use. Others may not be so obvious and will require a little reading to understand how best to incorporate that information into your flight planning. Also note that a color bar will appear to the right indicating how to read to the colored contours for each map layer.

That's all there is to using XC Maps. Once the basic functionality is understood, interpreting how to the utilize the various soaring parameters is next. Consider following along with the next example. We'll be posting more extensive examples with time.

A Quick Example by Chris Galli:
Let's say I'm interested in knowing what conditions will be like for flying my favorite mountain site in Salt Lake City, Utah. I center the map to that location and zoom in for the general area. After that, the first two map layers I look at are the Top of Usable Lift, and the wind barbs overlay for the Top of Usable Lift. This is a quick way to see how strong the winds will be and how high I can expect to thermal for that region for a given time (in this case at 3PM local time). Click here to see this example. You can see on the map that winds aloft are reasonably light. Specifically, 8 mph at 13K ft over the valley, and not much stronger at 18K ft over the mountains to the east. The lift potential looks good, so I then look at the Thermal Updraft Velocity and check that the thermal strength is forecasted to allow a glider to climb effectively. In this case, it seems quite reasonable for the area. Click here to see this example. The daily forecast from the local NWS office predicts there to be cloudy conditions throughout the day, with a slight chance (20%) for thunderstorms to develop later in the day. Knowing this, I take a quick look at the forecasted Cumulus Cloud Base and Cumulus Cloud Depth parameters. I'm specifically looking to see if cloud base is forecasted to be much lower than the Thermal Tops. If it is, then where there is significant moisture in the lower atmosphere, there will likely be thunderstorms. Click here to see this example. The cloud depth over the mountains to the east of Salt Lake is predicted to reach 6000 feet. Although this could be benign, it is something to note. This supports the local forecast of possible thunderstorms for the area. In addition to all of this, I look at the 3 day point forecast to see how the wind and thermal lift changes over a single point. In this case, it's a point in the center of the Salt Lake Valley. Click here to view this image. At the bottom of this image, I look at the the time intervals. The time is my local time, so for Sept 17 at 15 (3PM) I can see the top of the lift is expected to be 13,776 feet (in red). This agrees with the Top of Usable Lift map for this period, which indicates a value between 13K and 14K ft. (bright red).

I didn't fly this day. Even though everything looked OK, there were also indications of high and mid level clouds spreading over the area throughout the day. This was indicated in both comments from the local NWS office, as well as the XC Map GFS cloud cover images. Click here to see this example. Note that the Sky Cloud Cover forecast is for extensive, widely spread cloud cover for northern Utah. And of course, when extensive shading of the surface occurs, lift potential diminishes along with it due to a loss of trigger mechanisms and direct surface heating (heat flux) among other things. This is exactly what happened. Several pilot reports for the day indicated there was a short window for flying the western slopes of the Wasatch around 3PM when the clouds finally shaded out the region. Even with the ground being shaded, soaring was still possible but thermals were not extending much more than 8000 feet.

Other Interface Options
There are quite a few other options to explore which greatly enhance the core XC Maps application.

• Point Forecasts
• Sun Angles
• Time Offset
• Change Units
• Save Profiles
• Load Profiles
• Overlay Roads
• Transparency Settings
• Mouse Scroll-Wheel Zooming