Property of Lear Siegler

1. Property of Lear Siegler

3. FRONTAL WEATHER Property of Lear Siegler

4. Terminal Learning Objective Page D-1 in Student Handout: ACTION: CONDITION: STANDARD:

5. ELO Identify the characteristics common to all fronts IAW FM 1-230.

6. WARM COLD A FRONT IS A BOUNDARY BETWEEN AIR MASSES OF DIFFERENT DENSITIES. Property of Lear Siegler

7. WARM COLD Frontal formation: When two high pressure cells exist so that the circulation of air is converging between them, a front is formed. The converging air currents veer upward creating a zone (trough) of low pressure. Property of Lear Siegler

8. H cP L H mT Property of Lear Siegler

9. Frontal weather is caused by the lifting of warm moist air by colder more dense air. ALL FRONTS HAVE A TEMPERATURE INVERSION

10. FRONTAL DISCONTINUITIES • TEMPERATURE • DEWPOINT • PRESSURE “ FALL THEN RISE” • WIND SHIFT : APPROX 90° DRIFT CORRECTION TO THE RIGHT Property of Lear Siegler

11. Primary factors affecting frontal weather are slope, speed, moisture content, and stability.

12. questions ?

13. ELO Identify the general characteristics of a cold front IAW FM 1-230.

14. Cold Front The leading edge of a cold air mass, normally moving toward the southeast. Property of Lear Siegler

15. ColdFront • Slope • Clouds • Width of weather band • Winds • Direction of movement • Speed • Symbol

16. 1 mile 80 miles ColdFront Slope – avg. 1:80

17. 25,000’ cumuliform predominant CUMULONIMBUS 20,000’ 15,000’ 10,000’ COLD AIR WARM AIR Cold Front COLD FRONT Property of Lear Siegler

18. type of weather Post-frontal, can be violent Cold Front Property of Lear Siegler

19. 50 miles Width of weather band Cold Front Property of Lear Siegler

20. northwest southwest Cold Front Winds

21. Property of Lear Siegler

22. southeast Direction of Movement

23. Average 25 knots Speed

24. WARNING! If speed of front exceeds 25 kts a squall line may form as much as 300 miles ahead. Squall lines may include tornadoes, hail, and destructive winds! Speed

26. Property of Lear Siegler

27. Property of Lear Siegler

28. SQUALL LINE Property of Lear Siegler

29. NOTE: You must recognize in color and black and white. color-blue triangle shapes, pointing in direction of movement Symbol

30. questions ?

31. ELO Identify the general characteristics of a warm front IAW FM 1-230.

32. Warm Front The trailing edge of a cold air mass, normally moving generally toward the northeast, being overridden by warmer air. Property of Lear Siegler

33. WarmFront • Slope • Clouds • Width of weather band • Winds • Direction of movement • Speed • Symbol

34. 1 mile 200 miles WarmFront Slope – avg. 1:200

35. stratiform predominant Warm Front Property of Lear Siegler

38. 25,000’ 20,000’ Width of weather band 15,000’ Ci 10,000’ Cs As WARM AIR Ns COLD AIR St 400 to 600 miles 0 100 MILES 200 300 400 500 WARM FRONT Property of Lear Siegler

39. southwest southeast WARM FRONT Winds

40. Property of Lear Siegler

41. northeast WARM FRONT Direction of Movement

42. Average 15 knots WARM FRONT Speed

43. NOTE: You must recognize in color and black and white. WARM FRONT color - red half moon shapes, pointing in direction of movement Symbol

44. questions ?

45. ELO Identify the general characteristics of a stationary front IAW FM 1-230.

46. Stationary Front A front which is not moving, speed of zero to less than 5 knots. H H Property of Lear Siegler

47. StationaryFront • Slope • Clouds • Width of weather band • Winds • Direction of movement • Speed • Symbol similar to warm front

48. Stationary Front Winds – light and variable, tend to parallel isobars. Speed – zero to < 5 kts Movement - unpredictable H H Property of Lear Siegler

49. Stationary Front NOTE: You must recognize in color and black and white. combination of symbols for cold and warm fronts, alternating sides of line of front color – alternating red and blue Property of Lear Siegler

50. questions ?