A cold front is defined as the leading edge of a cooler mass of air, replacing (at ground level) a warmer mass of air, which lies within a fairly sharp surface trough of low pressure. It forms in the wake of an extratropical cyclone, at the leading edge of its cold air advection pattern, which is also known as the cyclone's dry conveyor belt circulation. Temperature changes across the boundary can be as much as 30 °C (54 °F). When enough moisture is present, rain can occur along the boundary. If there is significant instability along the boundary, a narrow line of thunderstorms can form along the frontal zone. If instability is less, a broad shield of rain can move in behind the front, which increases the temperature difference across the boundary. They are stronger in the fall and spring transition seasons, and weakest during the summer. When they catch up with the preceding warm front, the portion of the boundary which does so is then known as an occluded front.
Read more about Cold Front: Development of Cold Front, Precipitation, Temperature Changes, Characteristics of Boundaries Around An Extratropical Cyclone
Famous quotes containing the words cold and/or front:
“Under bare Ben Bulben’s head
In Drumcliff churchyard Yeats is laid.
An ancestor was rector there
Long years ago, a church stands near,
By the road an ancient cross.
No marble, no conventional phrase;
On limestone quarried near the spot
By his command these words are cut:
Cast a cold eye
On life, on death.
Horseman pass by!”
—William Butler Yeats (1865–1939)
“It is told that some divorcees, elated by their freedom, pause on leaving the courthouse to kiss a front pillar, or even walk to the Truckee to hurl their wedding rings into the river; but boys who recover the rings declare they are of the dime-store variety, and accuse the throwers of fraudulent practices.”
—Administration in the State of Neva, U.S. public relief program. Nevada: A Guide to the Silver State (The WPA Guide to Nevada)