Definition
A surface weather condition in which water droplets are lifted by the wind from a body of water and carried through the air in sufficient quantity to reduce horizontal visibility at or near the surface to six statute miles or less. Reported in aviation weather observations using the contraction BLPY.
Plain English
Wind picks up water from the sea or a lake and carries it through the air as a fine mist, thick enough to make it harder to see.
Context Anchor
Seen in aviation weather reports, forecasts, and pilot observations near oceans, large lakes, or other open water, especially during strong winds.
Derivation
From 'blowing' (carried by wind) and 'spray' (fine droplets of water). The pairing in weather reporting specifically means the spray is wind-driven from a water surface, not falling precipitation.
Why Pilots Care
It reduces visibility and can affect safe low-level flight, takeoff, and landing decisions over water.
Grounding Statement
Picture strong wind ripping droplets off wave tops and blowing them across the shoreline or water surface like a moving sheet of mist.
Intuition Check
Blowing spray is not rain falling from clouds. It is water lifted from a surface by wind and blown through the air.
Example Sentence 1
The METAR reported blowing spray, warning the seaplane pilot of strong winds and reduced visibility over the bay.
Example Sentence 2
The pilot delayed the approach because blowing spray made the shoreline hard to see.