Meteorologists currently use a unit of 100 000 seconds ( a quantity on the order of a day ) to quantify atmospheric vorticity at the synoptic scale; the unit, however, does not have a formal name.
22.
On a synoptic scale, the most important factors that controls the climate in Chile are the Pacific Anticyclone, the southern circumpolar low pressure area, the cold Humboldt current, the Chilean Coast Range and the Andes Mountains.
23.
Warm air at the surface creates a surface low ( not necessarily on a weather map / synoptic scale ), which rises aloft-- the air column reaches higher altitudes for a given pressure, and is less dense, and " stretches out " more.
24.
As in a case in December 1986 when the precipitation shield of a snow storm was confirmed to be traveling at 125 mph over Missouri, Kansas, and Iowa and with some species of synoptic scale dust storms and some cold fronts which also can attain forward speeds of up to 110 mph or more, the system hooked into an area of fast-moving upper-level winds and / or a strong jet stream.
25.
As supercells and multi-cell thunderstorms dissipate due to a weak shear force or poor lifting mechanisms, ( e . g . considerable terrain or lack of daytime heating ) the gust front associated with them may outrun the squall line itself and the synoptic scale area of low pressure may then infill, leading to a weakening of the cold front; essentially, the thunderstorm has exhausted its updrafts, becoming purely a downdraft dominated system.
