Mountain, Coastal, and Local Weather Effects
Concepts to master
Understand orographic lifting and the resulting windward cloud/precipitation and leeward drying (rain shadow). Know mountain wave formation, lenticular clouds, rotor zones, and the associated severe turbulence and downdrafts. Recognise foehn/chinook warming as air descends leeward. Understand valley and slope winds, anabatic and katabatic flows, and nocturnal drainage. Coastal effects include sea and land breezes, coastal fog (advection and radiation types), and the influence of sea surface temperature on stability.
Know how local effects modify fronts and stability: mountains can enhance or dissipate convection, and coastal boundaries can focus convergence. Also understand gap winds and the effect of terrain on surface wind direction.
Traps
Questions often assume mountain waves always produce cloud, or that leeward conditions are calm. Another trap is confusing sea-breeze timing and direction, or treating coastal fog as purely radiative.
Rule of thumb
If the wind is perpendicular to a ridge and strong aloft, expect mountain waves and possible rotors. The windward side gets cloud; the leeward side gets subsidence, clearing, and turbulence.