Prevailing winds are light to moderate, northeasterly and southwesterly. Soon after Fort Hall, the Oregon and California trails diverged in northwesterly and southwesterly directions. The interior highlands disturb the winds, forcing them into a westerly/southwesterly direction. Summer is dominated by strong southwesterly monsoon winds. While moving rapidly westward, the depression began disorganizing due to southwesterly wind shear. Southwesterly winds bring warm air from Central Asia and the Middle East. Windsurfing is common off the West Quay, usually at low tide in southwesterly winds. Embedded within southwesterly flow ahead of mid-latitude trough, the storm moved generally northeast. Monarchs from the Northeast tend to migrate in a southwesterly direction. It was around here that the all-important southwesterly monsoon winds began to pick up. Initially, strong southwesterly wind shear prevented further significant intensification. A predominantly southwesterly wind blows through town, with wind speeds averaging around . After peaking in intensity, Ignacio began weakening as southwesterly wind shear increased. Shortly thereafter, southwesterly vertical shear began increasing, causing the hurricane to weaken. The historic vegetation was mixed woodland, with occasional goat prairies on southwesterly facing slopes.