Extratropical Cyclones Flashcards
If the surface winds backs from northeast to north, Halifax usually experiences__
Cold air advection
If the surface winds veer from east to southeast to south, Halifax usually experiences__
Warm air advection
Where are fog and drizzle most likely to develop in a mature extratropical cyclone?
In the cold air just ahead of the surface warm front
What direction is the low center moving if a weather station reports a wind shift from northeast to the north and then northwest and a steady rain turn into snow flurries?
From southwest to northeast, east of the station
What sector of a mature extratropical cyclone is precipitation usually the most steady and persistent?
Northeast
What is the coldest sector of a mature extratropical cyclone?
Northwest of the cyclone center
What is the warmest sector of a mature extratropical cyclone?
Southeast of the cyclone center
What is the surface wind direction in the northwest sector of a mature extratropical cyclone?
Northwest
What is the direction of the surface wind circulation about an Alberta-type cyclone when viewed from above?
Counterclockwise and inward
Why does a wave cyclone have a cold side and a warm side?
Surface winds in a wave cyclone blow counterclockwise and inward. Winds on the left of the cyclone track have a component from the north and cause cold air advection whereas winds to the right of the cyclone track have a component from the south and are responsible for warm air advection
What happens when a cyclone occludes?
The system moves into colder air and the faster cold front merges with the slower warm front. The warm sector begins to separate from the storm center and shortly afterward the central pressure begins to rise and the storm weakens.
Why does an Alberta-track cyclone typically produce less precipitation than a Colorado-track cyclone?
Because the Alberta storm is further away from the source of moisture and travels faster
Why do most cyclones that cross North America travel toward the east and northeast?
Westerly winds aloft in the middle and upper troposphere steer cyclones. Because extratropical cyclones typically develop to the east of an upper-air trough, the steering winds are directed from the southwest towards the northeast.
Why does colder weather often occur after an intense extratropical cyclone has passed through the area in the winter?
Because an arctic or polar anticyclone often follows in the wake of a departing intense extratropical winter cyclone. Conditions are ideal for extreme radiational cooling when the center of a cold anticyclone slowly moves over a region covered by a fresh mantle of snow.
