Question

When would ISOLD, OCNL, or FRQ be used in a GFA and with what kind of weather?

a. Isolated, Occasional, Frequent in thunderstorms
b. Isolated, Occasional, Frequent in clear skies
c. Isolated, Occasional, Frequent in fog
d. Isolated, Occasional, Frequent in precipitation

Answer 1

In a Graphical Forecast for Aviation (GFA), ISOLD, OCNL, and FRQ descriptors are used to denote the coverage and frequency of precipitation, such as thunderstorms, with isolated indicating 10-20% coverage, occasional 30-50%, and frequent over 50% of an area.

Step-by-step explanation:

ISOLD (Isolated), OCNL (Occasional), and FRQ (Frequent) are terms used in a Graphical Forecast for Aviation (GFA) to describe the coverage and frequency of certain weather phenomena. These terms would be used with the kind of weather listed as 'd' meaning Isolated, Occasional, and Frequent in precipitation. These descriptors help pilots understand the extent of the weather they may encounter. For example, isolated thunderstorms mean that thunderstorms are scattered and affect only 10-20% of a particular area, while occasional may refer to 30-50%, and frequent implies that thunderstorms are occurring in greater than 50% of the area.