The complement to a
Low Pressure Area, a
High Pressure Area is an area which contains air pressures higher than surrounding areas. These areas are generally associated with
sinking air. Because of this, they are usually largely free of
clouds.
precipitation is quite rare in high pressure areas, although sometimes localized convection will still occur.
Winds around
high pressure areas usually flow out from the center - in a
clockwise direction in the
northern hemisphere,
counter-clockwise in the
southern hemisphere.
High Pressure Areas are generally associated with 'fair' weather, however they are definitely prone to weather extremes. When a strong high pressure area builds in, it can result in powerful winds - the Santa Ana Winds of Southern California are caused by a high pressure area over Utah or Nevada. Temperatures under a high can also be very extreme - the hottest and coldest temperatures recorded are usually under high pressure areas. Also, droughts can be caused if a high pressure area stays stationary for too long.
On a weather map, High Pressure Areas are denoted by the letter H.