Fronal Mechanics 3.3

Question 1

Define Air Mass.

Answer 1

A large body of air that has essentially uniform temperature and moisture conditions in a horizontal plane.

Question 2

Define Front

Answer 2

An area of discontinuity that forms between 2 contrasting air masses when they are adjacent to each other. Thought of as a border, boundary, or line between the air masses.

Question 3

Describe the Structure of a Front.

Answer 3

Either side of the front diminish with increase in Alt.
Significant weather occurs in the lower layers.
Name according to the temperature change they bring.
Move attached to Low Pressure System (trough)and IsoBar.
Move Perpendicular to the way they are. Drawn.
90 degree shift from one side to another.

Question 4

Describe the Discontinuities used to locate and Classify Fronts.

Answer 4

**TDWP**Tough/Defense/Wins/Playoffs
Temperature - Names the front.
Dew Point 
Winds
Pressure

Question 5

Describe the factors that influence Frontal Weather.

Answer 5

MCSSSMarine Corps/Saves/Salty/Sailors
M Moisture Content - Dew Point
C Contrast between Air masses - Temp and Moisture
S Speed of Frontal movement
S Slope of the front
S Stability of Lifted Air

Question 6

Describe the conditions associated with a Cold Front.

Answer 6

Overtaking Cold air isDenser than Warm Air. “BullDozer”
Frontal lifting creates Unstable Conditions “Ahead of the Front”
Cooler Temp and Clear skies “After Passage”
Narrow Frontal Zone
Normally moves SE at 20KTS

Question 7

Describe the characteristics of a Squall Line.

Answer 7

Depicted as Dash Double Dotted Dash red lines _.._
Line of Severe Thunderstorms
Exact cause unknown
Forms 50-300 Miles ahead of Cold Front
Can Form Without cold Front
Hazardous to Aviation.

Question 8

Describe the characteristics of a Warm Front.

Answer 8

Warm air Advances over Dense Cold Air. “Slow, Lazy Blob”
Extensive Forward Slop
Weather occurs ahead of Surface Front
STeady Precipitation and Reduced Vis. Ahead of Passage
Winds Shift SE to SW with Passage

Question 9

Describe the conditions associated with a Stationary Front.

Answer 9

Alternating Cold and Warm Front Symbols in Opposite Directions
Weather Similar to Warm Front
Align in ANY Direction
180 degree Wind Shift - C VS W pulling away from each other.

Question 10

Describe the Conditions associated with Occluded Fronts.

Answer 10

Formed when Cold Front Overtakes a Warm Front(due to Speed)
Named based on whichever touches the Ground C vs W.
Purple W and C Front symbols
Pressure Falls then Rises.
Winds Shifts SE to NW with Passage.

Question 11

Describe the conditions associated with an Inactive Front.

Answer 11

Known as Dry Fronts.
No Clouds or Precipitation.
Wind shift and Temp change Occurs.
Marks area of potentially unfavorable flying conditions.