The effect is that you get a high pressure area at the surface but a relative low pressure area in the upper atmosphere.
22.
Unseasonably cold air will cover most areas east of the Rockies on Wednesday as a sprawling Arctic high pressure area envelopes the region.
23.
If the nor'easter takes the East Coast track, that usually indicates the presence of a high pressure area in the vicinity of Bermuda.
24.
The high pressure area that brought much less humid air to most of the Northeast during the last two day will slowly move east.
25.
Hot conditions with abundant sunshine will spread from the interior West into the western Plains as an enormous high pressure area over Utah strengthens.
26.
It passed without incident, but began to intensify rapidly as it encountered the edge of an unusually intense high pressure area over southeastern Canada.
27.
This high pressure area is formed due to strong descending motion behind the squall line, and could come in the form of a downburst.
28.
A warming trend will develop across the Mississippi Valley as breezes from the south develop on the western flank of the high pressure area.
29.
Meanwhile, an equally large high pressure area over the eastern Pacific Ocean will promote abundant sunshine across the West, with only patchy clouds near the coast.
30.
With an unusually strong high pressure area located over The Bahamas, the tropical depression moved westward through the southern Caribbean near the northern coast of South America.
