C18 - Fronts and Frontal Depressions Flashcards
What is a Warm Front?
Warmer Air displaces Colder Air.
What is a Cold Front?
Colder Air displaces Warmer Air.
Little movement of either Air Mass is called what?
Quasi-Stationary Front.
What is a Polar Front?
Boundary between Polar Maritime and Tropical Maritime.
What Latitudes can the Polar Front be found in the Northern Hemisphere (2)?
- Summer = 65°N.
- Winter = 35°N
Where can you find the Polar Front in the Northern Hemisphere (2)?
- Winter = Florida to UK.
- Summer = Newfoundland to North Scotland.
What is an Arctic Front?
Boundary between Arctic Continental and Polar Maritime/Continental.
Arctic Fronts may move to ‘____’ Latitudes in the Winter?
Lower.
What is the Mediterranean Front?
Boundary between Polar Continental and Tropical Continental.
When does the Mediterranean Front exists?
Winter.
True or False. Thunderstorms in the ITCZ can reach 45,000ft?
True.
What causes a Polar Front Depression?
Turbulence at the boundary between two airstreams.
In what direction does a Polar Front Depression move in?
West to East.
What are the Upper Winds in a Polar Front Depression?
Westerly.
What is the Frontal Slope of a Warm Front?
1:150.
How long is a Warm Front?
600-800 km.
What sequence of Cloud exists in a Warm Front?
Ci, Cs, As, Ns and St.
How in a Warm Front can Precipitation exist from the Frontal Surface Point?
200 nm.
How far does the general Weather in a Warm Front extend from the Frontal Surface Point?
5-700 nm.
In a Warm Front, the Geostrophic Wind blows ‘____’ to the Isobars with the Low on the ‘____’ in the Northern Hemisphere (2)?
- Parallel.
- Left.
How can you calculate the Warm Front Speed?
2/3rds of the Geostrophic Wind Speed.
What happens to the Wind ahead of a Warm Front?
Increases and slightly Backs Southernly.
What happens to the Temperature ahead of a Warm Front?
Steady Low.
What happens to the Dew Point ahead of a Warm Front?
Steady Low.
What happens to the Pressure ahead of a Warm Front?
Steady Falls.
What happens to the Cloud ahead of a Warm Front?
Increasing to 8/8 with Ci, Cs, As, Ns and Sc.
What happens to the Precipitation ahead of a Warm Front?
Light continuous at As and moderate continuous at Ns.
What happens to the Visibility ahead of a Warm Front?
Decreases.
What happens to the Wind at the Warm Front?
Sharply Veers.
What happens to the Temperature at the Warm Front?
Rises.
What happens to the Dew Point at the Warm Front?
Rises.
What happens to the Pressure at the Warm Front?
Decreases Slightly.
What happens to the Cloud at the Warm Front?
8/8 with Ns and St.
What happens to the Precipitation at the Warm Front?
Moderate/Heavy Continuous.
What happens to the Visibility at the Warm Front?
Very Poor, Fog can occur.
What happens to the Wind in the Warm Sector?
Usually from the SW.
What happens to the Temperature in the Warm Sector?
Steady.
What happens to the Dew Point in the Warm Sector?
Steady.
What happens to the Pressure in the Warm Sector?
Decreases Slightly.
What happens to the Cloud in the Warm Sector?
6/8 to 8/8, some large breaks with St and Sc.
What happens to the Precipitation in the Warm Sector?
Dry or Light Drizzle.
What happens to the Visibility in the Warm Sector?
Poor.
What is the Frontal Slope of a Cold Front?
1:50/75.
What Cloud exists in a Cold Front?
Embedded Cumulonimbus and Cumulus.
How long is a Cold Front?
200-300 km.
How far does the general Weather in a Cold Front extend from the Frontal Surface Point?
30-50 nm.
What happens to the Wind at the Cold Front?
Sharply Veers, gusts and squalls.
What happens to the Temperature at the Cold Front?
Falls.
What happens to the Dew Point at the Cold Front?
Falls.
What happens to the Pressure at the Cold Front?
Starts to Rise.
What happens to the Cloud at the Cold Front?
All Cloud Types.
What happens to the Precipitation at the Cold Front?
Heavy Rain, Snow, Hail and Thunderstorms.
What happens to the Visibility at the Cold Front?
Poor in Precipitation but good elsewhere.
What happens to the Wind behind the Cold Front?
Slight Veer to NW.
What happens to the Temperature behind the Cold Front?
Steady Low.
What happens to the Dew Point behind the Cold Front?
Steady Low.
What happens to the Pressure behind the Cold Front?
Rises Slowly.
What happens to the Cloud behind the Cold Front?
4/8 to 6/8, Cu and CB developing.
What happens to the Precipitation behind the Cold Front?
Showers developing with Hail and Thunderstorms a possibility.
What happens to the Visibility behind the Cold Front?
Good except in Precipitation.
What is the Speed of a Quasi-Stationary Front?
5 kts.
What conditions will form in a Stable Stationary Front during Summer (2)?
- Stratiform Clouds.
- Drizzle/Light Rain.
What conditions will form in a Stable Stationary Front during Winter?
Sleet/Snow.
What conditions will form in an Unstable Stationary Front during Summer (2)?
- Cumulus Clouds.
- Showers and Frontal Fog.
What conditions will form in an Unstable Stationary Front during Winter?
Snow Showers.
What is an Ana Front?
Air in the Warm Sector is rising more.
What is a Kata Front?
Warm Sector Air descends.
What is the term given when a Cold Front catches up with a Warm Front?
Occluded Front.
What is a Warm Occlusion?
Cold Front rides up and over a Warm Front.
When does a Warm Occlusion occur?
Usually found in Winter but can occur anytime.
Describe the Air in a Warm Occlusion?
The Cold Air ahead of the Warm Front is colder than the Air behind the Warm Front.
What is a Cold Occlusion?
Cold Front slips underneath the Warm Front.
When does a Cold Occlusion occur?
Usually found in Summer but can occur anytime.
Describe the Air in a Cold Occlusion?
The Cold Air ahead of the Warm Front is warmer than the Air behind the Warm Front.
