In aviation routine meteorological reports (METARs) and terminal aerodrome forecasts (TAFs), the terms VC (vicinity) and DSNT (distant) mean that the reported or forecast weather is between 5 to 10 nautical miles (VC) and beyond 10 nm (DSNT) from the reporting station.
But what happens when next to METARs and TAFs at your departure and destination airports there’s only one reporting station along your route?
Here’s an excellent tool to see forecast weather conditions over a wide area: the Aviation Weather Center’s Graphical Forecasts for Aviation (GFA). Enter your route using the flight path tool, and once your route is depicted on the map, zoom in to see the details. Menu buttons at the top allow you to look at each weather condition that might affect your flight, and a sliding timeline shows you the forecast conditions expected for your flight’s duration. One feature that would have helped the pilot who filed the ASRS report is the “Clouds” forecast. Zooming into the flight route, you’ll see forecast cloud bases and tops. Each menu option provides a specific key so you can readily understand what you’re looking at.
The GFA information makes it easier to stay VFR and avoid becoming a VFR-into-IMC accident statistic. Just take the time to compare your route of flight with the forecast conditions. Weather can change, but you’ll be better prepared to deal with it when it does. Consider providing a pirep (pilot weather report) to help out your fellow pilots as well.