ADDS - Aviation Digital Data Service

ADDS - METARs Help Page (5 of 5)
Back to METARs Page
example METARs applet By default, the tool loads with an icon at all locations where there is data for the current hour. This icon is shaded green for VFR (Visual Flight Rules), blue for MVFR (Marginal VFR), and red for IFR (Instrument Flight Rules). The amount of cloudiness (Clear, Scattered, Broken, Overcast) is also displayed by this icon - view the legend for the plot key. Placing the cursor over one of these icons causes a text message to appear which reveals the cloud coverage/bases and visibility (the two main ingredients which determine flight category - IFR/VFR/MVFR).
Next, zoom into your region of interest by clicking and holding the left mouse button, then drag the mouse while continuing to keep the mouse button depressed. This creates a "rubber-band" which will be the zoom area. Then let go of the mouse button and the tool will zoom into that region bounded by the red rectangle.
Now, you can turn on certain variables reported at airports such as temperature, winds, altimeter setting, etc. by simply choosing which variables from the checklist found near the center below the map. If your zoom level causes too much data overlap, the tool will eliminate lower priority sites in order to keep the map from becoming a terrible clutter. If you want all sites no matter how cluttered the display may be, then choose to show all sites (or more) using the checkbox to the far right (below map).
Once you have choosen to display particular parameters such as temperature or winds, then placing the cursor over a particular station location will cause the full raw text METAR to appear.