21. Warm, maritime air can bring springlike conditions while strong Arctic air masses can push lows to between. 22. Usually, said Kousky, El Nino tends to generate strong west-to-east winds that break up large Arctic air masses . 23. Deeper in the Arctic air mass , the upper Middle West will be variably cloudy, breezy and very cold. 24. The Arctic air mass that gripped much of the contiguous states Sunday felled scores of records for chill. 25. Early on Friday, the mercury fell to one degree as the coldest part of the arctic air mass arrived. 26. Such a vertical variance indicates the shallowness of the Arctic air mass that invaded the Deep South this week. 27. A big snowstorm blanketed President Kennedy's inauguration in 1961, and an Arctic air mass forced Reagan's 1985 swearing-in inside. 28. An arctic air mass has been trapped across interior Alaska by a blocking high-pressure system over the Bering Sea. 29. And things promised to get worse, with an Arctic air mass squatting over the Northeast with no sign of moving. 30. A wavering front will separate an expanding arctic air mass over the Northeast from increasingly humid air over the Southeast.
