Flat, unbroken terrain, and water cause the smoke to take longer to blend into a uniform smoke haze or blanket, requiring a greater distance between the smoke release point and the target area. Obstructions, such as trees and small buildings, tends to make smoke into a uniform screen much closer to the target area. Large hill masses and mountains tend to split winds and cause strong cross currents which excessively disperse smoke, creating holes in smoke coverage and unevenness in the smoke screen. Thermally induced slope winds make it difficult to establish and maintain a smoke screen. Slopes and valleys also create thermally-induced slope winds.
Winds tend to blow upslope during the day and downslope at night.
Smoke and obscurants will support any type of offensive operation at any level because smoke generally favors the attacker. Smoke is used to conceal units and individual weapon systems. This enables the commander to maneuver behind a screen and deceive the enemy about his strength and weakness. Smoke can be used to support maneuver, provide additional firepower and protect the force. The TC immediately backs up under the cover of his smoke screen.