Wx - General Flashcards
Gas changing directly to solid is called
Deposition
Solid to gas change is called
Sublimation
Relative humidity
Relative Humidity (
• Relative humidity is the ratio of the actual water vapour present
in the air to the amount which the same volume of air would
hold if it were saturated at the same atmospheric pressure and
temperature.
> Saturated air has 100% relative humidity.
> Completely dry air has 0% relative humidity.
• Knowing the “spread” between the dew point and the current
temperature gives us an indication of the relative humidity.
> Temperature +30° Dew point -10° (Very dry air)
> Temperature +15° Dew point +14° (High humidity)
Dry adiabatic lapse rate
3% per 1000’.
Use this for calculations of temperature at altitude for dry air.
What lapse rate to use for calculating cloud base
2.5°C per 1000 feet
What is could base formula
1000 x (temp - dew point) / 2.5 = Cloud base in feet AGL
What is the saturated adiabatic lapse rate or SALR?
1.5°C per 1000 feet of increase in altitude
Use this for calculations of temperature at altitude in saturated air
Radiation is
Reflection of the earths rays
Conduction is
Warm air contacting cold air
Advection
Horizontal movement of air
Convection
Une equal surface heating
If an altimeter is set 1 inch too high (say 30.92 instead of 29.92), the altimeter will read
1000’ high
0.1” would be 100’ high
Cloud type associate with steady rain is
Stratocumulus
WRT cyclone and anti cyclone, which was does air move?
Clockwise around an anticyclone and counter clockwise around a cyclone
In a climb, as surface friction decreases, winds tend to
Veer and increase
In a descent, they back and decrease
