1What condition requires clouds, fog, or dew to form?
water vapor
2Calculating cloud base
Cloud base = temperature/dewpoint = #/4.4 per 1000ft
-> Example:
(70F-48F)/4.4 * 1000
- surface is 1000 MSL so 5000+1000 = 6000
3Stratus Clouds
Forms when moist, stable air is lifted
4Conditions for fog, or low clouds to develope
- temp/dewpoint is small and decreasing
- temperature is above freezing
- water condenses
5What causes Radition Fog to form?
- warm moist air
- flatland area
- a clear calm night
6What causes Advection Fog to form?
- when a layer of warm air moves over a cooler surface via the wind transporting warm air over a cooler surface
- common under cloudy skies
- mostly occurs on coastlines
7What can Steam Fog cause?
- low level turbulance
- hazardous icing
8Characteristics of moist, unstable air
- cumuliform clouds
- showey precipitation
9low level temperature inversions occur...
- stable
- smooth air
- poor visibility
10Dewpoint is...
- the temperature in which air must cool to become saturated
11What causes Frost to form?
- temp of collecting surface has to be a lower temp than the dewpoint of air
- dewpoint must be below freezing
12Lapse Rate
- is the decrease in temp with an increase in altitude
- indicates unstable air
- low lapse rate is an indicator of the stability in the atmosphere
13Stratus clouds can be produced when....
- warm stable air travels upslope
14If an airmass is unstable...
it will cause a cloud with vertical development and turbulance
15Clouds are characterized by....
height range
16Cumulonimbus
- the most turbulant cloud
- needs lifting action and unstable conditions
- one of the tallest clouds
17Thunderstorm Stages
- cumlumus stage: has lifting action and vertical movement resulting in continus updraft
- Mature Stage: the stage of the greatest intensity
- Dissipating Stage: characterized by a ton of downdrafts and weak updrafts. releases latent energy
18Wake Turbulance
- created by air downwash from the creation of lift
- intensity depends on aircraft weight, speed, and configuration
- greatest strength occurs when the aircraft generating the lift is heavy, clean, and slow
- be cautious of quartering tailwind when avoiding wake turbulance, because it was the most hazardous
19Mountain Turbulance
- almond shapped lens cloud
- looks stationary
- can have 50KTs of turbulance
- lenicular cloud
- pilots can expect it in winds of 40 KTS below a mountain ridge
20Wind sear
- can occur at any altitude
- expected in areas of low level temperature inversion, frontal zones, and clear air turbulance
- can be expected in temp inversions, when wind speed is 2000-4000 ft above surface at least 25 KTS
21Squall Lines
- narrow bands of thunderstorms
- develops ahead of a cold front
- contain severe steady state thunderstorms
- presents the most hazardous conditions infront of an aircraft