Over the past decade, I have made numerous road trips between Colorado and Missouri; until today, I cannot recall one in which the entire 800-mile drive was made under a cloudless sky. Becoming aware of this fact during the trip, I started looking for even a hint of clouds on distant horizons; alas, none were seen.
High pressure controlled the entire Great Plains province today, shunting any Pacific moisture into Canada and blocking any flow from the Gulf of Mexico. Under such conditions, the air within the dome sinks, further compressing and drying the air. Since the formation of clouds and showers requires lift, atmospheric conditions within the high pressure dome negate any chance of their development.
In addition to the cloudless sky, evidence of the low humidity was made evident by the rapid evaporation of power plant steam and by the short contrails of commercial jets. Under more typical conditions, we see the long exhaust trails of these planes crisscrossing the sky, often distorted by the effects of high altitude winds; today, their linear exhaust clouds rapidly disappeared within seconds of their production.
As one might expect, persistent high pressure domes are found in many desert regions and can lead to prolonged drought in other areas. These domes are also characterized by light surface winds which, combined with the sinking air, exacerbate air pollution in urban centers.
