*Analysed position refers to the positions of tropical cyclones fixed by the Observatory based on observation data available in real time. The size in terms of radius of the 'Potential Track Area' corresponding to different forecast hours are determined from the error statistics of the forecasts issued in past years (updated in 2022) and are as shown in the following table: It will be particularly larger beyond 72 hours and is indicated with lighter shadings on the map. The area grows as the forecast hour increases. Literally, it means that among 10 times of track forecast for similar situations, the tropical cyclone will be centred within the indicated area in about 7 times. By pressing the 'Potential Track Area' button, the probable area within which the tropical cyclone will fall with a probability of 70% will be shown. While the forecast positions and track indicate the most likely future path of the tropical cyclone, they may deviate from the actual path of the storm.Please bear in mind the uncertainty of the tropical cyclone locations as described below in using this function. The user can use the controls on the left of the map to change the area of interest and to zoom into city or even street levels. Detailed information of the tropical cyclone, including latitude, longitude, classification and the maximum sustained wind near centre will be shown when placing the mouse cursor over the analysed or forecast positions.*The tropical cyclone track, analysed positions and maximum sustained wind near centre are based on Hong Kong Observatory's tropical cyclone warning for shipping. The two low waters each day are the higher low water and the lower low water.No Tropical Cyclone Warning Signal in force The two high tides on a given day are normally not the same height – these are the higher high water and the lower high water in tide tables. Tides are mostly semi-diurnal (meaning two high waters & two low waters each day), or diurnal (meaning one tidal cycle per day). But in some locations the moments of slack tide differ quite a lot from those of high and low water. Slack water normally happens near high water and low water. Then the tide reverses direction and is said to be turning. When a tidal current ceases it is called slack water or a slack tide. Tides produce currents known as tidal streams. The water stops falling, reaching low tide.Sea level falls over several hours, revealing the intertidal zone ebb tide.The water rises to its highest level, reaching high tide.Sea level rises over several hours, covering the intertidal zone flood tide.Tide changes proceed over several stages: The Ocean Isle Beach area experiences four tides a day, two high and two low each day.While tides are usually the largest source of short-term sea-level fluctuations, sea levels are also subject to forces such as wind and barometric pressure changes, resulting in storm surges, especially in shallow seas and near coasts. Tides are when sea level rises and falls due to the combined effects of forces of gravity exerted by the Moon and the Sun and also the rotation of the Earth.

They are not certified to be correct, and they do not incorporate the effects of tropical storms, El Niño, seismic events, continental drift, or changes in global sea level. Both the author and the website provider assume no liability for damages arising from use of these predictions. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Tide tables