OTHER TOPICS -----> Intro./Maps Atmosphere Pressure/Wind Moisture
Storms Forecasting Climates and Change Optics

MOISTURE/PRECIP CHAPTERS -----> Humidity Clouds Stability Precipitation

Precipitation Processes

I.   MOISTURE CONCEPTS AND TERMINOLOGY

A.   Supersaturated

B.   Supercooled

II.   PRECIPITATION PROCESSES AND TYPES

A.   Processes

  1. ice crystal formation ... video demo
    • riming
    • snowflake growth
  2. collision coalescence
B.   Types
  1. rain
  2. snow (graupel) (definition of blizzard)
  3. sleet ("ice pellets") vs. freezing rain ("ice storm" ... close up)
  4. hail: small-to-deadly ... (cross section)
    • freeze liquid = clear; freeze ice crystals = milky
C.   Measurement (0.01" or mm or "trace")
  1. standard NWS rain gauge
  2. weighing rain gauge
  3. tipping bucket
  4. Doppler radar estimates
  5. snow water equivalent (SWE) (data)
III.   DISTRIBUTION

A. Distribution: annual average and seasonal shift

  1. wettest = equatorial / tropics
  2. 20-30° latitude = driest (Atacama Desert, Chile)
B.   U.S. Distribution
  1. wettest in Cascades
  2. driest in interior west and southwest
C.   El Nino / La Nina D. Precipitation Variability : small -vs.- large

MOISTURE/PRECIP CHAPTERS -----> Humidity Clouds Stability Precipitation