1.   A mix of clouds and sun will cover the northern Plains as upslope winds combine with weak disturbances in the jet stream.

2.   High winds will combine with arctic air to create potentially dangerous conditions.

3.   Humid, onshore winds will combine with seasonably warm air to trigger a couple of showers in central Florida.

4.   In the Middle Atlantic region, onshore winds will combine with thick clouds to keep readings below seasonal levels.

5.   Meanwhile, increasing winds will combine with the snow over the eastern Dakotas and northern Minnesota to produce near blizzard conditions at times.

6.   Onshore winds will combine with a weak disturbance aloft to keep clouds over much of the Northwest.

7.   The frigid air over New England will moderate Tuesday as sunshine and lighter winds combine with slightly milder air aloft.

8.   Over the interior mountains of Puerto Rico southerly upslope winds combined with high moisture content of the air may produce local areas of dense fog.

9.   Light winds combined with daytime heating and afternoon sea breezes will give the greatest chance for thunderstorms over the western interior and west coast of Puerto Rico.

10.   Rain and snow were expected across much of the nation on Thursday, and wind could combine with the winter storm to create blizzard conditions in the Rockies.