south sides of the cyclones; if the pressure falls below 29.00 inches a violent storm, with winds from whole gale to storm strength, is certain.
The various types of cyclonic storms differ but little in character, and their names apply to the locality where they originate or are first observed. Thus, they are variously known as “Alberta,” “North Pacific,” “Northern Rocky Mountain,” “Colorado,” “Texas,” “Central,” and “West Indian.” Other names occasionally are used in designating the storms. The
Redway’s Physical Geography.
Wind, cloud, and precipitation in a cyclonic storm.
system employed by the Weather Bureau is one of convenience rather than of scientific value. About a third of the storms that cross the continent are of the Alberta and North Pacific type.
The map, p. 148, shows the isobars of a cyclonic storm. The low pressure at the center indicates a storm of unusual intensity; this is indicated also by the closeness of the isobars. In other words, the pressure gradient is steep, when the isobars are close, and this also indicates the degree of violence of the storm.
