Definition
Surface winds with an average speed of 30 knots or greater, measured at a standard height of about 10 meters (33 feet) above the ground, lasting long enough to be considered a steady condition rather than a short gust. In AIRMET Tango, sustained surface winds of 30 knots or more trigger an advisory.
Plain English
Steady winds at ground level that are blowing 30 knots or stronger and aren't just brief gusts. The wind has to keep blowing at that speed, not just spike for a moment.
Context Anchor
Seen in AIRMET weather advisories, especially when a route may have strong winds during takeoff, landing, taxi, or low-altitude flight.
Derivation
Sustained' comes from the Latin sustinere, meaning 'to hold up' or 'to keep going.' The idea is a wind speed that holds steady over time, rather than a momentary peak. This is what separates it from a gust, which is brief.
Why Pilots Care
Strong sustained surface winds increase takeoff and landing distances, affect directional control on the runway, and can limit operations at smaller airports.
Grounding Statement
Picture arriving at an airport where the wind is not just gusting once in a while, but steadily pushing hard across the ramp and runway.
Intuition Check
Do not read “sustained” as “the strongest gust.” Sustained surface winds are the steady wind near the ground; gusts are short increases above that steady wind.
Example Sentence 1
AIRMET Tango was issued for sustained surface winds of 30 knots or greater across the region, so we delayed departure until conditions eased.
Example Sentence 2
Although the METAR showed gusts to 38 knots, the sustained surface winds remained at 25 knots throughout the approach.