Meteorology 9

On shore and Off shore Winds Water and land cool at different rates as land heats up faster and cools faster than water. During the day air rises over land and so a wind blows in from the water. At night the air over the water rises and a wind blows out from the land. On-shore/ off-shore winds can emerge suddenly and result in a dramatic change in wind direction Its biggest impact is sudden gusts of wind and changing wind direction. Avoidance: be aware of these wind changes near bodies of water most prevalent during late evening and early morning

Anabatic and Katabatic Winds Winds in valleys will flow up-valley or down-valley as the air in the valleys warm and cool. Anabatic winds usually start mid-afternoon as the valley heats up. Katabatic winds occur at night-time and end shortly after sunrise both are stronger when skies are clear. These can be fairly predictable and are strongest during clear skies. Its biggest impact is sudden change of wind direction in valleys during the day. Avoidance: most prevalent during late afternoon and at night

Wind over Ridges Naturally as wind encounters a slope or ridge, it is forced to flow over that ridge. The air actually increases in speed as it does so this can lead to dramatic wind gusts near ridges - even some very small ridges. Winds at even the smallest of ridges can lead to very localized gusts and turbulence its biggest impact is sudden increase in wind and turbulence near ridges. Avoidance: observe any sudden changes in terrain near where you're flying Expect increased wind gusts near ridges