Aeronautical Terms beginning with F

Forecast Icing Conditions

Environmental conditions expected by an NWS or an FAA-approved weather provider to be conducive to the formation of in-flight icing on aircraft.

Forecast Icing Product (FIP)

The FIP examines numerical weather prediction model output to calculate the probability and severity of icing conditions, plus SLD potential. This product is automatically produced with no human modification. More information can be found on the AWC ADDS Web site.

Freezing Drizzle

Drizzle is precipitation at ground level or aloft in the form of liquid water drops that have diameters less than 0.5 mm and greater than 0.05 mm. Freezing drizzle is water that remains in a liquid form at air temperatures less than 0 °C (supercooled) and can freeze upon contact with objects on the ground or in the air.

Freezing Rain

Rain is precipitation at ground level or aloft in the form of liquid water drops which have diameters greater than 0.5 mm. Freezing rain is rain that exists at air temperatures less than 0 °C, remains in liquid form (supercooled), and freezes upon contact with objects on the ground or in the air.

Front

The boundary between two air masses. A front can be classified as cold, warm, occluded, or stationary.