the.com/coldfront
a wall of dense air shoving warm skies aside like a bouncer at closing time
means A cold front is the leading edge of a cooler air mass advancing into and displacing warmer air, often bringing a sharp shift in temperature, wind, and stormy weather.
from A compound of "cold" and "front," the latter borrowed from military language — a "front" being the line where opposing forces meet. Meteorologists of the early 20th century, notably the Norwegian school led by Vilhelm Bjerknes and his colleagues after the First World War, adopted the wartime metaphor of clashing battle lines to describe colliding air masses, giving us "front," "warm front," and "cold front."
- steep slope
- Advances faster than warm fronts, climbing sharply
- map symbol
- Blue line with triangles pointing where it heads
- storm trigger
- Forces warm air up, spawning thunderstorms and squalls
- temp drop
- Can plunge temperatures double digits within hours
- wind shift
- Passage flips wind direction, often clockwise
chicago january 1999 freeze — arctic coldfront brought -30°f windchills, killing 63 people and freezing lake michigan
texas february 2021 crisis — coldfront dropped to -2°f in dallas, caused blackouts affecting 4.5 million households