Figure11.2 Air mass source regions and their paths. Figure11-2 p295

Table 11-1 p295

Figure11.15 A surface weather map showing surface-pressure systems, air masses, fronts, and isobars (in millibars) as solid gray lines. Large arrows in color show air flow. (Green-shaded area represents rain; pink-shaded area represents freezing rain and sleet; white-shaded area represents snow.) Figure11-15 p305

Figure11.18 A vertical view of the weather across the cold front in Fig. 11.16 along the line X–X′. Figure11-18 p307

Figure11.14 The polar front represents a cold frontal boundary that separates colder air from warmer air at the surface and aloft. The more shallow arctic front separates cold air from extremely cold air. Figure11-14 p305

Figure11.19 The infrared satellite image (a) shows a weakening cold front over land on Tuesday morning, November 21, intensifying into (b) a vigorous front over warm Gulf Stream water on Wednesday morning, November 22. Figure11-19a p308

Table 11-2 p309

Figure11.22 Vertical view of clouds, precipitation, and winds across the warm front in Fig. 11.21 along the line P–P′. Figure11-22a p311

Table 11-3 p311

Figure11. 25 The formation of a cold-occluded front Figure11.25 The formation of a cold-occluded front. The faster-moving cold front (a) catches up to the slower-moving warm front (b) and forces it to rise off the ground (c). (Green-shaded area in (d) represents precipitation.) Figure11-25a p314

Figure11. 25 The formation of a cold-occluded front Figure11.25 The formation of a cold-occluded front. The faster-moving cold front (a) catches up to the slower-moving warm front (b) and forces it to rise off the ground (c). (Green-shaded area in (d) represents precipitation.) Figure11-25d p314

Figure11. 25 The formation of a cold-occluded front Figure11.25 The formation of a cold-occluded front. The faster-moving cold front (a) catches up to the slower-moving warm front (b) and forces it to rise off the ground (c). (Green-shaded area in (d) represents precipitation.) Figure11-25c p314

Figure11. 25 The formation of a cold-occluded front Figure11.25 The formation of a cold-occluded front. The faster-moving cold front (a) catches up to the slower-moving warm front (b) and forces it to rise off the ground (c). (Green-shaded area in (d) represents precipitation.) Figure11-25b p314

Figure11. 26 The formation of a warm-type occluded front Figure11.26 The formation of a warm-type occluded front. The faster-moving cold front in (a) overtakes the slower-moving warm front in (b). The lighter air behind the cold front rises up and over the denser air ahead of the warm front. Diagram (c) shows a surface map of the situation. Figure11-26c p314

Figure11. 26 The formation of a warm-type occluded front Figure11.26 The formation of a warm-type occluded front. The faster-moving cold front in (a) overtakes the slower-moving warm front in (b). The lighter air behind the cold front rises up and over the denser air ahead of the warm front. Diagram (c) shows a surface map of the situation. Figure11-26b p314

Table 11-4 p315

Figure11.12 Weather conditions during an unseasonably hot spell in the eastern portion of the United States that occurred between the 15th and 20th of April, 1976. The surface low-pressure area and fronts are shown for April 17. Numbers to the east of the surface low (in red) are maximum temperatures recorded during the hot spell, while those to the west of the low (in blue) are minimum temperatures reached during the same time period. The heavy arrow is the average upper-level flow during the period. The purple L and H show average positions of the upper-level trough and ridge. Figure11-12 p303

Figure11.17 A Doppler radar image showing precipitation patterns along a cold front similar to the cold front in Fig. 11.16. Green represents light-to-moderate precipitation; yellow represents heavier precipitation; and red the most likely areas for thunderstorms. (The cold front is superimposed on the radar image.) Figure11-17 p307

Figure11.8 After crossing several mountain ranges, cool moist maritime polar (mP) air from off the Pacific Ocean descends the eastern side of the Rockies as modified, relatively dry Pacific air. Stepped Art Figure11-8 p301

Figure11.10 An infra-red satellite image that shows maritime tropical air (heavy yellow arrow) moving into northern California on January 1, 1997. The warm, humid airflow (sometimes called “the pineapple ex-press”) produced heavy rain and extensive flooding in northern and central California. Figure11-10 p302

Figure11. 26 The formation of a warm-type occluded front Figure11.26 The formation of a warm-type occluded front. The faster-moving cold front in (a) overtakes the slower-moving warm front in (b). The lighter air behind the cold front rises up and over the denser air ahead of the warm front. Diagram (c) shows a surface map of the situation. Figure11-26a p314

Figure11.27 A visible satellite image showing a mid-latitude cyclonic storm with its weather fronts over the Atlantic Ocean during March, 2005. Superimposed on the photo is the position of the surface cold front, warm front, and occluded front. Precipitation symbols indicate where precipitation is reaching the surface. Figure11-27 p315