41. Storms in the atmosphere mix air masses to eliminate temperature differences. 42. The juxtaposition of contrasting air masses provides the fuel for storms. 43. Thunderstorms with downpours will develop in the sultry air mass across the Southeast. 44. The leading edge of an Arctic air mass will seep into northern Montana. 45. They traced those air masses backwards to find the source of the pollution. 46. A dry air mass will soothe the northeast quadrant of the nation Saturday. 47. Several patches of thunderstorms will erupt in the steamy air mass . 48. Continental air masses bring significant amounts of snowfall during winter. 49. A warm, moist air mass covered most of the southeast. 50. Tornadoes form underneath severe thunderclouds in which warm and cold air masses are colliding.
