High-pressure area

Highs are middle-scale meteorological features that result from interplays between the relatively larger-scale dynamics of an entire planet's atmospheric circulation.

[2] High pressure systems in the temperate latitudes generally bring warm weather in summer, when the amount of heat received from the Sun during daytime exceeds what is lost at night, and cold weather in winter when the amount of heat lost at night exceeds what is gained during daytime.

[7] High-pressure areas form due to downward motion through the troposphere, the atmospheric layer where weather occurs.

Preferred areas within a synoptic flow pattern in higher levels of the troposphere are beneath the western side of troughs.

On English-language weather maps, high-pressure centers are identified by the letter H in English,[10] within the isobar with the highest pressure value.

[13] During the day, since no clouds are present to reflect sunlight, there is more incoming shortwave solar radiation and temperatures rise.

At night, the absence of clouds means that outgoing longwave radiation (i.e. heat energy from the surface) is not absorbed, giving cooler diurnal low temperatures in all seasons.

[19] The horse latitudes, or torrid zone,[20] is roughly at the 30th parallel and is the source of warm high pressure systems.

As the hot air closer to the equator rises, it cools, losing moisture; it is then transported poleward where it descends, creating the high-pressure area.

The land-based Siberian High often remains quasi-stationary for more than a month during the most frigid time of the year, making it unique in that regard.

[25] Surface winds accelerating down valleys down the western Pacific Ocean coastline, causing the winter monsoon.

[28] The highest barometric pressure ever recorded on Earth was 1,085.7 hectopascals (32.06 inHg) measured in Tosontsengel, Zavkhan, Mongolia on 19 December 2001.