Definition
In a METAR, SQ is the contraction used to report a squall — a sudden, strong increase in wind speed of at least 16 knots, with the wind sustained at 22 knots or more for at least one minute.
Plain English
SQ is the code on a weather report that means a sudden, strong burst of wind happened — not just a gust, but a sharp jump in wind speed that held on for at least a minute.
Context Anchor
Seen in METAR and other aviation weather reports, usually in the present-weather part of the report.
Derivation
Squall comes from older Scandinavian roots meaning a sudden gust or shriek of wind. The two-letter SQ is simply a shortened code used to keep weather reports compact.
Why Pilots Care
Sudden wind shifts from a squall can affect aircraft control during takeoff and landing.
Grounding Statement
Picture a steady windy day suddenly turning into a much stronger blast that holds for more than just a moment.
Intuition Check
Do not read SQ as just “windy” or as any small gust. In weather reports, SQ means a defined sudden wind increase strong enough to be reported as a squall.
Example Sentence 1
The METAR included SQ in the present weather, so the pilot delayed departure until the wind settled.
Example Sentence 2
The pilot delayed departure after seeing SQ in the weather report due to expected wind changes.