Weather Radar Used to Detect and Forecast Rain
Puzzle 12 of Good luck Easy Pack
Question is: Weather Radar Used to Detect and Forecast Rain
and the answer is: DOPPLER
Word Meaning:
DOPPLER — (medicine, by ellipsis, informal) Ellipsis of Doppler ultrasonography: Any of various types of ultrasonography that use the Doppler effect; especially, medical versions thereof.
Definitions from Wiktionary.