U.S. DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
Air Traffic Organization Policy
[link to www.faa.gov
February 9, 2012
Subject: Air Traffic Control
Section 6. Weather Information.
2-6-4. WEATHER AND CHAFF SERVICES
a. Issue pertinent information on observed/reported weather and chaff areas. When requested by the pilot, provide radar navigational guidance and/or approve deviations around weather or chaff areas.
1. Issue weather and chaff information by defining the area of coverage in terms of azimuth (by referring to the 12-hour clock) and distance from the aircraft or by indicating the general width of the area and the area of coverage in terms of fixes or distance and direction from fixes.
WEATHER/CHAFF AREA BETWEEN (number)O'CLOCK AND (number) O'CLOCK (number) MILES,
(number) MILE BAND OF WEATHER/CHAFF FROM (fix or number of miles and direction from fix) TO (fix or number of miles and direction from fix).
2. When a deviation cannot be approved as requested and the situation permits, suggest an alternative course of action.
UNABLE DEVIATION (state possible alternate course of action).
FLY HEADING (heading),
PROCEED DIRECT (name of NAVAID).
b. In areas of significant weather, plan ahead and be prepared to suggest, upon pilot request, the use of alternative routes/altitudes.