Tropical cyclone warnings and watchesTropical cyclone warnings and watches are alerts issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local population and civil authorities to make appropriate preparation for the cyclone, including evacuation of vulnerable areas where necessary. It is important that interests throughout the area of an alert make preparations to protect life and property, and do not disregard it on the strength of the detailed forecast track.
Synoptic scale meteorologyIn meteorology, the synoptic scale (also called the large scale or cyclonic scale) is a horizontal length scale of the order of or more. This corresponds to a horizontal scale typical of mid-latitude depressions (e.g. extratropical cyclones). Most high- and low-pressure areas seen on weather maps (such as surface weather analyses) are synoptic-scale systems, driven by the location of Rossby waves in their respective hemisphere.
Hurricane KatrinaHurricane Katrina was a devastating that resulted in 1,836 fatalities and caused damage estimated between 97.4billionto145.5 billion in late August 2005, particularly in the city of New Orleans and its surrounding areas. At the time, it was the costliest tropical cyclone on record, tied now with Hurricane Harvey of 2017. Katrina was the twelfth tropical cyclone, the fifth hurricane, and the third major hurricane of the 2005 Atlantic hurricane season. CyclogenesisCyclogenesis is the development or strengthening of cyclonic circulation in the atmosphere (a low-pressure area). Cyclogenesis is an umbrella term for at least three different processes, all of which result in the development of some sort of cyclone, and at any size from the microscale to the synoptic scale. Tropical cyclones form due to latent heat driven by significant thunderstorm activity, developing a warm core. Extratropical cyclones form as waves along weather fronts before occluding later in their life cycle as cold core cyclones.
Numerical weather predictionNumerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to predict the weather based on current weather conditions. Though first attempted in the 1920s, it was not until the advent of computer simulation in the 1950s that numerical weather predictions produced realistic results. A number of global and regional forecast models are run in different countries worldwide, using current weather observations relayed from radiosondes, weather satellites and other observing systems as inputs.
AdvectionIn the field of physics, engineering, and earth sciences, advection is the transport of a substance or quantity by bulk motion of a fluid. The properties of that substance are carried with it. Generally the majority of the advected substance is also a fluid. The properties that are carried with the advected substance are conserved properties such as energy. An example of advection is the transport of pollutants or silt in a river by bulk water flow downstream. Another commonly advected quantity is energy or enthalpy.
Lake PontchartrainLake Pontchartrain (ˈpɒntʃətreɪn ) is an estuary located in southeastern Louisiana in the United States. It covers an area of with an average depth of . Some shipping channels are kept deeper through dredging. It is roughly oval in shape, about from west to east and from south to north. In descending order of area, the lake is located in parts of six Louisiana parishes: St. Tammany, Orleans, Jefferson, St. John the Baptist, St. Charles, and Tangipahoa. The water boundaries were defined in 1979 (see list of parishes in Louisiana).
Atlantic Oceanographic and Meteorological LaboratoryThe Atlantic Oceanographic and Meteorological Laboratory (AOML), a federal research laboratory, is part of the National Oceanic and Atmospheric Administration's (NOAA) Office of Oceanic and Atmospheric Research (OAR), located in Miami in the United States. AOML's research spans tropical cyclone and hurricanes, coastal ecosystems, oceans and human health, climate studies, global carbon systems, and ocean observations. It is one of seven NOAA Research Laboratories (RLs).
SquallA squall is a sudden, sharp increase in wind speed lasting minutes, as opposed to a wind gust, which lasts for only seconds. They are usually associated with active weather, such as rain showers, thunderstorms, or heavy snow. Squalls refer to the increase of the sustained winds over that time interval, as there may be higher gusts during a squall event. They usually occur in a region of strong sinking air or cooling in the mid-atmosphere.
AnticycloneAn Anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere as viewed from above (opposite to a cyclone). Effects of surface-based anticyclones include clearing skies as well as cooler, drier air. Fog can also form overnight within a region of higher pressure.
