High Pressure Delivers Sun To Start Week

Posted at 9:04 AM, Oct 13, 2013
and last updated 2013-10-13 09:04:19-04

WEST MICHIGAN – I always wonder as a Meteorologist if people really know, understand, or care (for that matter) what high pressure or low pressure is and how it affects our weather. It’s pretty simple actually, but these two atmospheric pressure systems deliver totally different weather. My point is if you understand each one, then you’ll know what kind of weather to expect when you see them on a map or over our area.

Low pressure is usually associated with clouds and precipitation. The system itself pulls air inward to the center of circulation and forces it to rise. Rising air motion tends to lead to clouds and precipitation because the air cools as it rises and the moisture can condense out on to cloud condensation nuclei and form clouds.

On the other hand, high pressure creates something called subsidence. It forces air to sink. That sinking promotes a dry air mass and the end result is usually fair weather with sunshine. Note the high is exactly the opposite of the low.

Sunshine will rule over Michigan on Sunday and Monday, but slowly be cut-off Tuesday as another low pressure system presses in to the region. Our next rain chance arrives Tuesday P.M.. Get the complete West Michigan forecast at