Fronts Flashcards
What is the definition of a Front?
The transition zone between two air masses
During the passing of a front, abrupt changes in temp, wind, moisture content, and humidity are dependent on:
- The stability and moisture content of the warmer air mass
- The speed of the front as determined by the cold air mass
- The slope of the front
What does a cold front (where cold air is moving in to warm air) and a warm front (where warm air is filling in behind a passing cold front) look like on a weather map?
Cold Front: Spiky blue line with the spikes in the direction the cold front is moving
Warm Front: Red bubbles pointing in the direction into which the warm are is filling in
How is a stationary front depicted on a weather map?
Alternating blue spikes and red bubbles. The red and blue spikes and bubbles are pointing in opposite directions.
Where will frontal weather happen in a cold front vs warm front?
Cold Front: weather will happen behind the blue spiky line
Warm Front: weather will happen ahead of red bubble line
What are the symbols on a weather map for cold, warm, and stationary fronts?
An occluded front and a trowal are the same thing. Which one is American and which one is Canadian and what do their symbols look like on a map?
If something is an ‘upper’ front, how are those depicted on weather maps?
Same symbols just not colored in
What is a stationary front?
A warm, high pressure air mass, and a cold high pressure air mass trying to shove in to each other but neither will give
What moves faster, a warm front or cold front?
Cold front
How many degrees is a typical cold front’s slope and how fast can they move?°
- 1 to 1.5°C
- 30KTS or more
- Depth is usually about 50NM
What kind of clouds would indicate a warm front is coming?
Cirrus to start, then altostratus, then nimbostratus, then stratus
How far in front of an advancing warm front can clouds and weather form?
250-600NM
What is the typical slope of a warm front?
1:150 - 1:250
**For every 1NM of height, its 250NM across the ground
If you are flying at 6000ft and 12000ft, what does height do in terms of where you will hit weather when flying towards a warm front?
The higher you are, the farther ahead of the front you will hit weather
Signs of a cold front as it passes
What happens after cold front passage?
Warm front weather diagram
What is an occluded/trowal front?
This happens when a cold front associated with a low ‘catches up’ to a warm front. It overtakes it and undercuts the warm front
Where can most of the weather be found in an occluded/trowal front?
In the trowal itself
How does an upper front differ from a trowal/occlusion?
With a trowal, two colder air masses converge and shove the warm are up
With an upper front, warmer air moves up over cold air on its own. So the air below is still super cold but at altitude its nice and warm
What is frontal fog?
Associated with weather at warmer fronts. Happens when frontal precip falls into the colder air ahead or below the warm air, causing the colder air to become saturated through evaporation
What is a fast moving cold front?
- Mostly forms in summer
- Very steep, cold, dense, air that moves fast
- Warm air ahead of it is forced to rise violently
- May produce a squall line is warm air is moist and unstable already
- Very narrow band of violent weather
- Winds veer with frontal passage and are strong, gusty, and turbulent well after passage
