Clouds
Isobar spacing
Fronts are always located
In a low pressure trough
Two main categories of icing
Structural and Engine
How long is a METAR valid for?
1h
What is required for a thunderstorm to form
Unstable Air
Lifting Action
Moisture
Cloud altitudes and prefixes
Low: 0-6,500 (no prefix)
Middle: 6,500-20,000 (alto-)
High: 20,000-40,000 (cirro-)
Faster moving fronts are generally accompanied by a _____ _____ of _____ _____
Narrow band of severe weather
Most common type of icing and the associated front
Mixed
Occluded front
What does a flag on a wind barb indicate?
50 knots
Turbulence intensity classification and descriptive word
Light (slight)
Moderate (larger)
Severe (large)
Extreme (violent)
Force Parallel to isobars
Pressure gradient force
Forms on the surface at the leading edge of an advancing thunderstorm
What is a gust front
Types of precipitation
drizzle
rain
frozen
Decode "630102"
6 - icing
3 - type and intensity
010 - base in hundreds of feet
2 - depth of layer in thousands of feet
Where are thunderstorms most severe inside the cell?
Upper 2/3's of the cell
Ceiling definition with numbers
Height AGL of lowest broken (5/8-7/8) or overcast (8/8) layer
OR
Vertical visibility into an obscuring phenomenon
Warm and cold front wind shift directions
Cold: SW -> NW
Warm: SE -> SW
4 Methods of Lifting
Convergence
Frontal
Orographic
Thermal
What are the conditions for fog to be reported?
Bases at or below 50ft
Greater than 20ft thick
Reduces visibility to less than 5/8 mile
Causes for turbulence
Thermal
Mechanical
Frontal
Wind shear
Stable Air characteristics (clouds, turbulence, visibility, winds, precipitation, icing)
stratiform
smooth
poor
steady winds & precip
rime
High pressure air moves ______, _______, and _____
Down, out, clockwise
Clear Icing characteristics (temp, droplet size, associated clouds and stability)
0º - -10ºC
Large water droplets
Cumulus clouds
Unstable conditions
METAR codes: "UP"
Unknown precipitation
Microburst Characteristics
- wind speed
- diameter
- cloud type
- duration
- feet per min descent rate
20-200knots
1/4 - 2 1/2 miles wide
cumuliform
5-10 min
2000 - 6000 ft/min