101-5 Moisture, Clouds & Precipitation Flashcards
Relative Humidity
The actual water vapor in the air to that of which it could possibly present
What determines how much water vapor can be held in the air?
Temperature & Relative humidity
Warmer temps can hold more water vapor
If relative humidity = 100% saturated air
If relative humidity <100% unsaturated air
Dew Point
Temperature in which air must be cooled to become saturated
*as H20 is added to the air, the DP will rise
Temp/Dew Point Spread (SPREAD)
Temp - dew point (T-DP)
Conditions needed for FOG
- T-DP is < or = to 3 degrees C
- Decreasing T-DP spread
- Light winds
Condensation nuclei
Microscopic particles which can become condensation surfaces
Supercooled Water
Freezing Rain/Drizzle
Liquid that is below 0 degrees C
0 to -10 degrees C = stratiform clouds
0 to -15 degrees C = cumuliform clouds
Frost may form when the …
… dew point is 0 degrees C or colder
3 types of precip
- Liquid = rain/drizzle
- Freezing = freezing rain (warmer air above)
- Frozen = ice pellets (indicates FZRA above), snow, hail
Cold air over a warm lake = ?
Warm air over a cold lake = ?
showers
fog