What is “Weather and Chaff” information provided to pilots by ATC? This one appears in an entry under &quot;Additional Services&quot; in the FAA Pilot/Controller Glossary and claims that ATC provides a wide range of additional services to pilots, including &quot;Weather and Chaff&quot; information, which seems like an unusual entry.  What does &quot;chaff&quot; mean in this context?
Originally chaff was the remains of a wheat plant cut down and with the grains in the head thrashed out, which is then discarded.  It's also a biblical reference to the wicked condemned by God to hell i.e. &quot;the chaff, which the wind driveth away&quot;.  In modern times, it is associated with a physical countermeasure to radar whereby thousands of metallic strips are ejected out of an aircraft to confuse enemy radars or break the track of radar guided anti aircraft weapons.  I though the phrase in the P/CG might have been a reference to some sort of anachronistic term about the environment which was termed &quot;chaff&quot; but I don't know.  I did locate this story from NOAA's website where their weather radar in Louisville, KY, was spoofed by military chaff which had been dispersed during nearby training exercises.  This gives though to another risk of an aircraft flying through a cloud of chaff and ingesting it into the engines, or causing some other kind of system damage.  This would seem to be a remote possibility but who knows.  Anybody know what the P/CG meant by chaff in this reference.
In the Pilot/Controller Glossary, this is the definition of &quot;Chaff&quot; and would be its meaning in the context of &quot;Additional Services&quot; referenced in your question.

CHAFF- Thin, narrow metallic reflectors of various lengths and
frequency responses, used to reflect radar energy. These reflectors,
when dropped from aircraft and allowed to drift downward, result in
large targets on the radar display.

On some radar equipment chaff may appear similar to areas of precipitation.