Fig. 40. Comparison of flight trends and surface weather conditions on April 22-23, 1948. The meteorological data were taken from the U. S. Weather Bureau Daily Weather Map for 12:30 A. M. (CST) on April 23. The nightly station densities and the average hourly station density (shown in parentheses) are as follows:

5. Louisville: 9,100 (1,100)16. College Station: 13,300 (1,900)
6. Murray: 16,300 (2,700)17. Baton Rouge: 6,200 (1,000)
8. Stillwater: 1,900 (500)19. Lafayette: 2,800 (600)
9. Knoxville: 15,200 (1,700)21. Winter Park: 6,200 (700)
13. Oak Grove: 13,600 (1,700)23. Tampico: 11,100 (3,700)

Fig. 41. Winds aloft at 10:00 P. M. on April 22 (CST). Winds at 2,000 feet above mean sea level are shown in black; those at 4,000 feet, in white. Velocities are indicated by standard Beaufort Scale of Wind Force. The numbers in circles refer to the stations shown in [Figure 40].

Fig. 42. Comparison of flight trends and surface weather conditions on April 23-24, 1948. The meteorological data were taken from the U. S. Weather Bureau Daily Weather Map for 12:30 A. M. (CST) on April 24. The nightly station densities and the average hourly station density (shown in parentheses) are as follows:

1. Albion: 1,100 (300)14. Mansfield: 4,900 (1,200)
2. Ottumwa: 5,500 (900)16. College Station: 700 (100)
4. Lawrence: 5,400 (1,400)17. Baton Rouge: 1,700 (400)
5. Louisville: 13,300 (2,700)18. Pensacola: migration negligible
6. Murray: 9,800 (1,400)20. New Orleans: 1,600 (800)
8. Stillwater: 800 (100)21. Winter Park: 2,700 (300)
9. Knoxville: 8,000 (900)23. Tampico: 63,600 (6,300)
10. Memphis: 7,900 (1,000)24. Progreso: 31,300 (3,900)