Leading Edge of a Balmy Air Mass
This page is the CodyCross answer for the clue below from London, Group 491, Puzzle 2 (Trafalgar Square).
Question is: Leading Edge of a Balmy Air Mass
and the answer is: WARMFRONT
Word Meaning:
WARM FRONT — (meteorology) The trailing edge of a retreating mass of cold air.
Definitions from Wiktionary.