Gale

a wind of force 8 on the BEAUFORT SCALE (more than 30 knots).

Taken from Dictionary of Science

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A gale is a very strong wind. There are conflicting definitions of how strong. The U.S. Government's National Weather Service defines a gale as 34 to 47 knots (63 - 87 km/h or 17.5 - 24.2 m/s or 39 - 54 miles/hour) of sustained surface winds. Forecasters typically issue gale warnings when winds of this strength are expected.

Other sources use minimums as low as 28 knots (52 km/h) and maximums as high as 90 knots (170 km/h). Through 1986, the National Hurricane Center used the term gale to refer to winds of tropical storm force for coastal areas, between 33 knots (61 km/h) and 63 knots (117 km/h). The 90-knot (170 km/h) definition is very non-standard. A common alternative definition of the maximum is 55 knots (102 km/h).

The most common way of measuring winds is with the Beaufort scale (pronounced /ˈboʊfət/). It is an empirical measure for describing wind speed based mainly on observed sea conditions. Its full name is the Beaufort wind force scale.

Taken from Wikipedia

Jet Stream

a high-speed westerly wind in the region of the tropopause. The principal jets are the polar front and subtropical jets, which occur at heights between 10 and 15 km. The winter jet stream occurs between 50 and 80 km in the upper STRATOSPHERE. The wind speeds can reach 300 km/h. The air streams move north and south of their general trend, in surges, which are probably the cause of depressions and anticyclones. There are a number of separate jet streams, but the most constant is that of the subtropics. Jet stream speed and location are of importance to high-flying aircraft.

Taken from Dictionary of Science