FIGURE 5.22 Natural seeding by cirrus clouds may form bands of precipitation downwind of a mountain chain. Fig. 5-22, p.127

FIGURE 5.23 The streaks of falling precipitation that evaporate before reaching the ground are called virga. Fig. 5-23, p.128

* * * Below freezing all the way down 3000 2000 Height above the ground (m) * 1000 -20 -15 -10 -5 5 10 15 Temperature (°C)

* Below freezing above Above freezing below to sfc. 3000 2000 Height above the ground (m) Above freezing below to sfc. 1000 -20 -15 -10 -5 5 10 15 Temperature (°C)

* Below freezing above Above freezing layer in between 3000 2000 Above freezing layer in between Height above the ground (m) 1000 Thick subfreezing layer near-sfc. sleet -20 -15 -10 -5 5 10 15 Temperature (°C)

* Below freezing above Above freezing layer in between freezing rain 3000 2000 Above freezing layer in between Height above the ground (m) 1000 freezing rain Below freezing in shallow layer or at the surface -20 -15 -10 -5 5 10 15 Temperature (°C)

FIGURE 5.31Hailstones begin as embryos (usually ice particles) that remain suspended in the cloud by violent updrafts. When the updrafts are tilted, the ice particles are swept horizontally through the cloud, producing the optimal trajectory for hailstone growth. Along their path, the ice particles collide with supercooled liquid droplets, which freeze on contact. The ice particles eventually grow large enough and heavy enough to fall toward the ground as hailstones. Fig. 5-31, p.133

FIGURE 5.32 Components of the standard rain gauge. Fig. 5-32, p.134

FIGURE 5. 33 The tipping bucket rain gauge FIGURE 5.33 The tipping bucket rain gauge. Each time the bucket fills with one-hundredth of an inch of rain, it tips, sending an electric signal to the remote recorder. Fig. 5-33, p.135

How RADAR works

How RADAR works Transmitter sends out microwave pulse

How RADAR works Part of pulse reflected back

http://www.rap.ucar.edu RADAR Reflectivity

RADAR Estimated Rainfall Total FIGURE 5.34 (b) Doppler radar display showing1-hour rainfall amounts over Oklahoma for April 24, 1999. Fig. 5-34b, p.136

http://www.rap.ucar.edu RADAR Velocity

COLD WARM

COLD WARM Density  Density 

COLD WARM Shrinks down Expands up

COLD WARM Less weight More weight

COLD WARM LOW HIGH Pressure is

LOW HIGH COLD WARM Pressure is 100 mb 350 mb 100 mb 500 mb 350 mb

COLD WARM LOW HIGH

FIGURE 6. 4 The mercury barometer FIGURE 6.4 The mercury barometer. The height of the mercury column is a measure of atmospheric pressure. Fig. 6-4, p.146

FIGURE 6.5 The aneroid barometer. Fig. 6-5, p.146