7-1-16 Estimating Intensity of Rain and Ice Pellets
AIM Chapter 7. Safety of Flight — Section 7-1, Meteorology
Official text — AIM 7-1-16
AIM — FAA OPERATIONAL GUIDANCEa. Rain
1. Light. From scattered drops that, regardless of duration, do not completely wet an exposed surface up to a condition where individual drops are easily seen.
2. Moderate. Individual drops are not clearly identifiable; spray is observable just above pavements and other hard surfaces.
3. Heavy. Rain seemingly falls in sheets; individual drops are not identifiable; heavy spray to height of several inches is observed over hard surfaces.
b. Ice Pellets
1. Light. Scattered pellets that do not completely cover an exposed surface regardless of duration. Visibility is not affected.
2. Moderate. Slow accumulation on ground. Visibility reduced by ice pellets to less than 7 statute miles.
3. Heavy. Rapid accumulation on ground. Visibility reduced by ice pellets to less than 3 statute miles.
Reproduced from the FAA Aeronautical Information Manual (Basic (with Change 3)). The AIM is FAA guidance, not regulation. Verify against the official source before relying on it operationally.
Is this a regulation?
No — this is FAA guidance, not a regulation.
Aeronautical Information Manual. FAA operational guidance and recommended practices. The AIM is not regulatory, although it often explains how to comply with regulations.