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Questionnaire replies from forecasters in 16 tropical-cyclone warning centers are summarized to provide an overview of the current state of the science in tropical-cyclone analysis and forecasting. Information is tabulated on the data sources and techniques used, on their role and perceived usefulness, and on the levels of verification and accuracy of cyclone forecasting.
Questionnaire replies from forecasters in 16 tropical-cyclone warning centers are summarized to provide an overview of the current state of the science in tropical-cyclone analysis and forecasting. Information is tabulated on the data sources and techniques used, on their role and perceived usefulness, and on the levels of verification and accuracy of cyclone forecasting.
Considerable interest in the use of autonomous aircraft for atmospheric measurements in remote and hazardous areas worldwide has arisen over recent years. Their application in tropical cyclone reconnaissance is under study by the World Meteorological Organization and the International Council for Scientific Unions under the United Nations International Decade for Natural Disaster Reduction. More diverse experiments, particularly for stratospheric operations, are being planned by agencies in the United States.
The aerosonde can provide an economical and flexible element in these international initiatives. The concept is for a small aircraft (weighing less than 20 kg) with on-board meteorological sensors to provide radiosonde-quality observations at any location on the globe. Individual missions could span several thousand kilometers and several days' duration, using the Global Positioning System for autonomous navigation, and satellite relay for data return and flight-plan updates. With a supercharged engine, the aerosonde could make soundings from sea level to 100 hPa and back in a cycle of about 4 h. Aerosondes flying such profiles in routine wide-scale use are expected to achieve a per-sounding cost competitive with that of balloon-borne radiosondes, but with much greater flexibility of operation.
Considerable interest in the use of autonomous aircraft for atmospheric measurements in remote and hazardous areas worldwide has arisen over recent years. Their application in tropical cyclone reconnaissance is under study by the World Meteorological Organization and the International Council for Scientific Unions under the United Nations International Decade for Natural Disaster Reduction. More diverse experiments, particularly for stratospheric operations, are being planned by agencies in the United States.
The aerosonde can provide an economical and flexible element in these international initiatives. The concept is for a small aircraft (weighing less than 20 kg) with on-board meteorological sensors to provide radiosonde-quality observations at any location on the globe. Individual missions could span several thousand kilometers and several days' duration, using the Global Positioning System for autonomous navigation, and satellite relay for data return and flight-plan updates. With a supercharged engine, the aerosonde could make soundings from sea level to 100 hPa and back in a cycle of about 4 h. Aerosondes flying such profiles in routine wide-scale use are expected to achieve a per-sounding cost competitive with that of balloon-borne radiosondes, but with much greater flexibility of operation.
A brief description is given of the Cyclone Game, a direct simulation of many of the operational aspects of the Perth Tropical Cyclone Warning Centre. The game's main purpose is to provide tropical-cyclone forecasters with additional operational experience and skills. It may also be used to familiarize others with some of the complexities of tropical-cyclone forecasting. The game is controlled by a microcomputer and may be played by one or a team of “forecasters.” It has a modular structure and is designed for easy modification to suit local requirements.
We suggest that microcomputer-based simulations of severe weather events, such as described in this paper, have considerable potential as an educational and training tool.
A brief description is given of the Cyclone Game, a direct simulation of many of the operational aspects of the Perth Tropical Cyclone Warning Centre. The game's main purpose is to provide tropical-cyclone forecasters with additional operational experience and skills. It may also be used to familiarize others with some of the complexities of tropical-cyclone forecasting. The game is controlled by a microcomputer and may be played by one or a team of “forecasters.” It has a modular structure and is designed for easy modification to suit local requirements.
We suggest that microcomputer-based simulations of severe weather events, such as described in this paper, have considerable potential as an educational and training tool.
The Island Thunderstorm Experiment (ITEX) is a field and modeling study of the tropical thunderstorms that form regularly over Bathurst and Melville Islands north of Darwin, Northern Territory, Australia, during the transition season and breaks in the summer monsoon season. Such thunderstorms are of widespread occurrence in the tropics and they play an important role in tropical dynamics. ITEX is a joint project of the Bureau of Meteorology Research Centre and Monash University's Centre for Dynamical Meteorology. Preliminary studies have been used to plan an intensive period of observations that was carried out from 20 November to 10 December 1988. The resulting data will provide the basis for a series of analytical and numerical studies of tropical island thunderstorms.
The Island Thunderstorm Experiment (ITEX) is a field and modeling study of the tropical thunderstorms that form regularly over Bathurst and Melville Islands north of Darwin, Northern Territory, Australia, during the transition season and breaks in the summer monsoon season. Such thunderstorms are of widespread occurrence in the tropics and they play an important role in tropical dynamics. ITEX is a joint project of the Bureau of Meteorology Research Centre and Monash University's Centre for Dynamical Meteorology. Preliminary studies have been used to plan an intensive period of observations that was carried out from 20 November to 10 December 1988. The resulting data will provide the basis for a series of analytical and numerical studies of tropical island thunderstorms.
The outlook for tropical cyclone intensity forecasts from operational and from research perspectives was discussed during a panel discussion at the 19th Conference on Hurricanes and Tropical Meteorology. Whereas the operational requirement at the National Hurricane Center is to predict maximum 1-min sustained wind speeds at specific locations, the research community is addressing the prediction of the maximum wind or minimum sea level pressure in the storm. Commonality was found in the forecast strategies for subjectively predicting storm intensity. The panelists suggested improvements may be gained from additional observations, better conceptual and theoretical models of storm structure and behavior, and enhancements in statistical and numerical models.
The discussion period brought out opposing viewpoints on a number of topics. Both new observations and better use of the existing observations were believed to be necessary. The limitations and advantages of remotely sensed data for this problem were raised. The most vigorous debates were on the physical processes, such as existence or nonexistence of coupling between outer and inner core structure, and whether convection is simply a response to forcing or is an essential contributor to uncertainty in intensity forecasting. Several participants suggested that uncertainties related to the sea surface temperature and its evolution also contribute to the intensity forecast problem. Some specific suggestions for improving intensity forecasts are given in terms of new observations, new basic understandings, and new applied developments.
The outlook for tropical cyclone intensity forecasts from operational and from research perspectives was discussed during a panel discussion at the 19th Conference on Hurricanes and Tropical Meteorology. Whereas the operational requirement at the National Hurricane Center is to predict maximum 1-min sustained wind speeds at specific locations, the research community is addressing the prediction of the maximum wind or minimum sea level pressure in the storm. Commonality was found in the forecast strategies for subjectively predicting storm intensity. The panelists suggested improvements may be gained from additional observations, better conceptual and theoretical models of storm structure and behavior, and enhancements in statistical and numerical models.
The discussion period brought out opposing viewpoints on a number of topics. Both new observations and better use of the existing observations were believed to be necessary. The limitations and advantages of remotely sensed data for this problem were raised. The most vigorous debates were on the physical processes, such as existence or nonexistence of coupling between outer and inner core structure, and whether convection is simply a response to forcing or is an essential contributor to uncertainty in intensity forecasting. Several participants suggested that uncertainties related to the sea surface temperature and its evolution also contribute to the intensity forecast problem. Some specific suggestions for improving intensity forecasts are given in terms of new observations, new basic understandings, and new applied developments.
The BMRC Australian Monsoon Experiment is part of a concerted tropical research program aimed at improving our understanding of the physics and dynamics of tropical weather systems. It is based on the collection of high-density tropical upper-air soundings and radar data during two observational phases in October 1986 and January/February 1987. The objectives, background, and rationale for this program are described together with an overview of the design and timetable of the observing component.
The BMRC Australian Monsoon Experiment is part of a concerted tropical research program aimed at improving our understanding of the physics and dynamics of tropical weather systems. It is based on the collection of high-density tropical upper-air soundings and radar data during two observational phases in October 1986 and January/February 1987. The objectives, background, and rationale for this program are described together with an overview of the design and timetable of the observing component.
