Gravity Air resistance

Curvature Effect

Solute Effect Pure Water: High Vapor pressure Small rain drop Salty Water: Low Vapor pressure Large rain drop

Table 7-1, p. 166

Bergeron Process (ice-crystal process) Ice grows at the expense of water drops.

Accretion (riming) Ice collecting suppercooled water drops Results in icy snow pellets called graupel

Aggregation Ice collecting small ice particles to make a snow flake

Virga

Fall Streaks -- icy crystals or snow falling

Dendrite snow crystal

Fig. 7-11, p. 172

Fig. 7-12, p. 173

Rime: super cooled drop freezing on contact

Freezing Rain: rain freezes on contact.

Fig. 7-21, p. 180

Fig. 7-23, p. 182 Days with Freezing rain

Fig. 5, p. 183

Fig. 7-18, p. 179

5.5 inches

Polarized light