1.   An autumnal air mass will encompass most of the Middle West and Northeast Tuesday as sprawling high pressure moves southeast from Ontario.

2.   Bright sunshine and low humidity will cover most of the Northeast and Great Lakes as high pressure moves southeast from Ontario.

3.   Clouds will develop across Texas and parts of the Rocky Mountain states as an upper-level low-pressure zone moves southeast from Idaho.

4.   Clouds will thicken from southern New England to the middle states as the storm over the Southeast moves north.

5.   Clusters of strong thunderstorms will form in the humid air over the Missouri River Valley as a jet stream disturbance moves southeast from the Dakotas.

6.   The Northeast will be mainly dry and chilly as strong high pressure moves southeast from Ontario.

7.   The Northeast will be mainly sunny but chilly as sprawling high pressure moves slowly southeast from Ontario.

8.   Unsettled weather will cover most of the Western states Wednesday as an expansive whirlpool of high-level chill moves southeast from the Pacific Northwest.

9.   Very cold, dry air will settle over the northern Plains as high pressure moves southeast into Minnesota.

10.   Widespread snow showers will develop as a series of jet stream disturbances move southeast from Canada.