Weather Flashcards
What changes across a front?
Temperature, humidity, wind and pressure.
What types of fronts are there?
Warm front
Cold front
Occluded front
Stationary front
What is a warm front?
A Warm Front forms when a relatively moist, warm air mass slides up and over a cold air mass. As the warm air mass rises, it often condenses into a broad area of clouds. The warm air at the surface, behind the warm front, advances slowly, replacing the cold air at the surface. Stormy weather is typically associated with a warm front.
What is a cold front?
A cold front forms when a cold, dense air mass pushes under a warm, lighter air mass, forcing the warm air to rise. The cold air advances, replacing the warm air at the surface. Rain and even thunderstorms can form as the moisture in the warm air mass rises, cools, and condenses. As the cold front passes, winds become gusty. There is a sudden drop in temperature, and also heavy rain, sometimes with hail, thunder, and lightning. Atmospheric pressure changes from falling to rising at the front.
What is an occluded front?
Occluded fronts are usually a sign that the parent weather system has reached its mature stage and is decaying (decreasing in intensity). They are indicated by a purple line with alternating triangles and half-moons on the side of its motion.
What is a stationary front?
stationary front may form when a cold or warm front slows down, or it may grow over time from underlying surface temperature differences when there is little air mass movement, like a coastal front.
The weather associated with a stationary front is typically a mixture of weather from warm and cold fronts.
What are the different kinds of Fog?
Advection fog
Radiation fog
Upslope fog
Steam fog
Frontal fog
Ice fog
Where might you encounter wind shear?
is particularly hazardous to aircraft operations at low altitudes on takeoff or landing. Wind shear may be encountered almost anywhere. The most common encounters though are near thunderstorms or in gusty surface winds, typically after a frontal passage.
What is mountain wave?
mountain waves may contain strong clear air turbulence in the form of breaking waves and rotors, which can be damaging to all sizes of aircraft. Causes isolation in altitude.
Characteristics of a stable versus unstable atmosphere?
Unstable air : cumuliform clouds, showery precipitation, rough air / turbulence & good visibility.
Stable air: Stratiform clouds and fog, continuous precipitation, smooth air, fair to poor visibility.
How long is a METAR valid for?
For one hour. And they are typically issued once an hour at the 55 minute mark.
How often are TAFS issued?
Routine TAFs are valid for a 24-hour period and issued four times daily: 00Z, 06Z, 12Z, and 18Z, and are amended (updated) as conditions require.
What’s a squall line?
squall line is a line of severe thunderstorms that can form along and/or ahead of a cold front.
When does frost form?
if temperatures are cold enough and there is sufficient moisture. Specifically: the aircraft skin temperature is below freezing.
When can icing occur flying?
10°C visible moisture (clouds precip)
