The general trend is for the weather to come in from the west and move eastwards with the frontal systems, but there can also be more local weather phenomena such as occasional thunderstorms and Berg Winds, which are warm winds coming down over the mountains from inland. There can be considerable variation in weather conditions between different parts of Cape Town on any day, though the general tendency may be similar. For example rain may fall on the Cape Peninsula in the morning, and by afternoon these conditions may have moved over to the east side of False Bay and the peninsula may be clearing, with a significant wind directional shift from north-westerly to south-westerly, which mat be followed by south-easterly depending on the season. Local variation in wind strength may be extreme, as there may be a dead calm in one place and a gale force wind a few kilometres away. There are places known for exposure to both south-easterly and north-westerly winds, and some which are sheltered from one or the other, while the south-westerlies blow most places, but not usually to quite the same extremes.