Severe Weather
A thunderstorm is considered severe if it produces large hail, strong surface winds, or this
What is a tornado
Liquid precipitation that freezes before it reaches the surface
What is sleet
This type of air mass often forms over the Gulf of Mexico
What is a maritime tropical air mass
Another term for a low pressure system.
What is a cyclone.
Band of low pressure near the equator
What is the ITCZ
Hurricanes only form over this
What is warm water
These clouds form highest in the atmosphere
What are cirrus clouds
Overrunning typically occurs ahead of this
What is a warm front
Atmospheric pressure at sea level
What is 1013 mb
Areas of high pressure near 30 degrees latitude where ships were often becalmed
What are the horse latitudes
Snow blown by winds over 30 knots for at least 3 hours
What is a blizzard
Low clouds, generally forming a layer with a relatively uniform base
What are stratus clouds
The warmest type of air mass
What is a continental tropical air mass
Decreasing vorticity generally produces this in the upper atmosphere.
What is divergence
Large convection cells where air rises near the equator and descends near 30 degrees north and south latitude
What are Hadley cells
Sighting one of these results in a tornado warning, even if it hasn't reached the ground
What is a funnel cloud
Small particles that facilitate formation of cloud droplets
What are cloud condensation nuclei
Occurs when a cold front catches up to a warm front
What is an occluded front
Used to map troughs and ridges of pressure in the upper atmosphere
What are 500 mb heights
Upper-level bands of wind generated by steep gradients between cold and warm air
What are jet streams
A tropical storm becomes a hurricane when winds exceed this speed
What is 64 knots
Soft hail
What is graupel
This air mass often provides the air behind cold fronts west of the Rocky Mountains
What is a maritime polar air mass
A stage in cyclogenesis, this typically forms when low pressure intensifies along the stationary front, and results in develoment of a distinct cold front and warm front
What is a frontal wave
See-saw shift in atmospheric pressure between the eastern and western regions of the tropical Pacific
What is the Southern Oscillation