Another task in forecasting is that of the formation of cutoff lows. They generally form only off the southwestern coast of the United States and the northwestern coast of Africa. . The upstream ridge intensifies greatly. This intensifying upstream ridge contains an increasing, strong, southwesterly flow. . Strong northerlies on the west side of the trough. .
Height falls move south or southeastward. .
Strong cold air advection occurs on the west side of the upper trough. The constant pressure prognostic chart is about to take form. The forecasted position of the long wave troughs and ridges have been determined and depicted on the tentative prognostic chart. The position of the highs, lows, and cutoff centers were then determined and depicted on the tentative prognostic chart. Short waves were treated in a similar fashion.