1.   Another cluster of thunderstorms will develop in the mountains as the advancing sticky air is lifted.

2.   As the advancing cool air lifts the hot, muggy air, strong thunderstorms will develop.

3.   At the leading edge of the advancing cool air, isolated severe thunderstorms will erupt from southern Idaho to eastern Montana.

4.   Advancing cool air behind a cold front often resembles a wedge of cheese, with the thinnest slice of cool air located at the front.

5.   Advancing warm air will be resisted by retreating chilly air in the Ohio and upper Mississippi Valleys.

6.   Advancing drier air will trigger scattered thunderstorms from the eastern Great Lakes to the central Plains.

7.   Advancing polar air will reach the Dakotas later Monday, preceded by clouds and flurries.

8.   Advancing warm air will produce widespread clouds from the Great Lakes to the eastern Rockies.

9.   Clusters of thunderstorms will develop as the sultry air across the South is replaced by the advancing cool air.

10.   Cold air over the snow-covered regions around the western and northern Great Lakes will impede the progress of the advancing warmer air.