1.   The arctic air of deep winter.

2.   Another irony, since it is the lake that defines this usually bountiful growing region by moderating the cold Arctic air before it reaches the New York shore.

3.   Another reason is that this time, there is no vast pool of Arctic air in place to set the stage for the storm.

4.   Another surge of arctic air will cross the eastern Great Lakes on Wednesday, producing more heavy snow along the east shores of Lakes Ontario, Erie and Huron.

5.   Arctic air crossing the upper Great Lakes will produce snow showers and squalls from northern Michigan to central New York.

6.   Arctic air will continue its slow but inexorable progress toward the East Coast on Wednesday.

7.   Arctic air will move into northern and central New England on brisk breezes from the Northwest on Wednesday.

8.   Arctic air will penetrate southward across the Plains, sending a big chill as far south as Oklahoma and Texas.

9.   Arctic air will pour into the Northern Plains behind a sharp cold front while partly cloudy and seasonable conditions cover the Northeast.

10.   Arctic air, which has been massing over western Canada this week, will be poised to invade the western United States early next week.