Mountain-gap wind

A mountain-gap wind, gap wind or gap flow is a local wind blowing through a gap between mountains.

Gap winds are low-level winds and can be associated with strong winds of 20-40 knots and on occasion exceeding 50 knots. Gap winds are generally strongest close to gap exit.

Example flows include the surface winds blowing through the Strait of Gibraltar – one of the strongest winds in this region is called Levanter. Similar winds occur at other gaps in mountain ranges, such as the tehuantepecer and the jochwinde, and in long channels, such as the Strait of Juan de Fuca between the Olympic Mountains of Washington and Vancouver Island, British Columbia, Hinlopen Strait near Spitsbergen. In the Columbia River Gorge on the border of Washington and Oregon, the high frequency of gap winds has led to the installation of wind farms, and the large amount of wind surfing that takes place on the Columbia River.

Another example is the Koshava wind Košava (wind) in Serbia that blows along the Danube River.^[1] The South Carpathian Mountains and Balkan Mountains are channelling the flow into the Danube River basin in Romania and the exiting jet at the Iron Gates is known as the Koshava wind. The main characteristics of the Koshava wind are its high wind speed, southeasterly direction, persistence, and gustiness.^[2]

See also

• Wind gap (geographical feature)
• Valley exit jet

References

• Bendall, A. A., 1982: Low-level flow through the Strait of Gibraltar. The Meteorological Magazine, Vol. 111, pp. 149–153
• Colle, B. A., C. F. Mass, 2000: High-Resolution Observations and Numerical Simulations of Easterly Gap Flow through the Strait of Juan de Fuca on 9–10 December 1995. Monthly Weather Review: Vol. 128, pp. 2398–2422.
• Colle, B. A., C. F. Mass, 1998: Windstorms along the Western Side of the Washington Cascade Mountains. Part I: A High-Resolution Observational and Modeling Study of the 12 February 1995 Event. Monthly Weather Review: Vol. 126, pp. 28–52.
• Overland, J. E., and B. A. Walter, 1981: Gap winds in the Strait of Juan de Fuca, Monthly Weather Review: Vol. 109, pp. 2221–2233.
• Scorer, R.S., 1952: Mountain-gap winds; a study of the surface wind in Gibraltar. Quarterly Journal of the Royal Meteorological Society: Vol. 78, pp. 53–59
• Sharp, J. and C. F. Mass, 2002: Columbia Gorge Gap Flow: Insights from Observational Analysis and Ultra-High Resolution Simulation. Bulletin of the American Meteorological Society: Vol. 83, pp. 1757–1762.
• Steenburgh, W. J., D. M. Schultz, B. A. Colle, 1998: The Structure and Evolution of Gap Outflow over the Gulf of Tehuantepec, Mexico. Monthly Weather Review: Vol. 126, pp. 2673–2691.