NOAA/National Centers for Environmental Information


The toolkit manages the way information is displayed in the viewer through the use of layers. There are three different categories of layers in the viewer: Data, Overlay, and Background Maps (WMS).

This tutorial will explain how to use the Overlay Selector, which is a tool that controls the layers being displayed. Data and Overlays will be the only two categories covered in this tutorial. Background Maps (WMS) has its own Background Maps tutorial

To open the Overlay Selector, click Layers in the Left Side Tab or click Data in the viewer menu bar, then Layer Selector. CTRL-M will also bring up the Overlay Selector.

Layer Selector

The Overlay Selector has three tabs: Data layers, Overlay Selector, Background Maps (WMS).

Overlay Selector

The Data Layers tab has two sections for different data types available for viewing: radar and gridded/satellite. Each section has four variables: Visible, Transparency, Smoothing, and Legend.

The four variables control the following:

'Active' vs. 'Snapshot' Layers:

In the Weather and Climate Toolkit, a single 'active' data layer may be visualized. However, multiple 'snapshot' layers be visualized as well, which allows the visual comparison and layering of different data types. To create a snapshot layer, simply click on the 'Snapshot Layer' button on the bottom left.

Snapshot Layer Button

An entry in the snapshot layer section of the data layer list will be created for each new snapshot layer. Controls are provided to adjust the visibility, transparency and drawing order of the layer. The 'Isolate' button will make the selected snapshot layer the only layer visible, while the 'Zoom To' button will set the current view extent to the extent of the snapshot layer.

Snapshot Layer Controls

The Overlay Selector tab includes different layers which can be added to the background of the viewer to show climate divisions, NEXRAD sites, cities, states, counties, and interstates to name a few.

The layer visibility is controlled by checking or un-checking the box beside each layer name. The color can be adjusted by clicking on the color button with the layer. The size of the line drawn on the viewer is adjusted by using the dropdown list under size for each layer, size ranges from 1 to 5. Label visibility is controlled by checking or un-checking the label box with each layer.

Overlay Layers

At the bottom of the overlay selector tab, the Radar Layer On Top checkbox defines whether the radar data should be drawn on top of the overlays (this is turned off by default). The Load Shapefile button brings up a file selection window to add your own ESRI Shapefiles to the overlay selector.