WeatherAid: Software for continuous weather monitoring and coding* Meteorological Service, Nicosia, Cyprus At manned synoptic and aviation meteorological stations, the prevailing weather conditions are continuously under surveillance. These conditions are registered, coded and subsequently reported as ‘present’, ‘recent’ and ‘past weather’, accordingly. Meteorological observers carry out the above functions in accordance with internationally agreed practices, but often national procedures are adopted (World Meteorological Organization (WMO ) 1995, 1998). Normally, monitoring the current weather requires keeping a weather logbook in which various aspects of the observed weather are registered. This includes not only the weather phenomena themselves but also their times of onset and cessation and changes of type. At fixed times, it is the meteorological observer’s task to come to a decision for the proper SYNOP† and METAR‡ weather codes to be reported, based on the registered weather sequence. The purpose of the present article is to introduce a new approach that can become a convenient tool for recording present and past weather and for partly automating SYNOP and METAR reports. This new approach can help in both the traditional (manual) weather monitoring and the international coding practices by exploiting modern computer technologies. The development of this new idea is the outcome of several years of meteorological observing, monitoring and coding of the weather, and of a thorough knowledge of all the problems related to the above complex procedures. All of these have led to the development of WeatherAid, an advanced
software tool for registering and coding the weather. WeatherAid is a very good example of the exploitation of computer science techniques in efficiently managing a quite complex operational meteorology domain. WeatherAid was developed as a softwarebased handling agent of all the procedures in registering and coding, as shown in Fig. 1. This figure contrasts the complex traditional methodology and the simple computerbased tool presented here for professionally observing, registering and coding weather phenomena.
Traditional weather recording and coding Traditionally, the state of the weather is registered in weather logbooks by using
some kind of shorthand approach. Francis Beaufort used letters as abbreviations, denoting the weather sequence. The set of weather annotations that he introduced nearly 200 years ago is widely known by the inventor’s name as Beaufort letters (see Meteorological Office 1982). The adoption of Beaufort letters, along with similar coding practices for cloud and wind, not only made it easier for observers to make detailed brief notes, but also introduced a common language among all those observing the weather (Pouncy 2003). It is beyond the scope of the present article to describe this shorthand approach or to go into any detail about its use. However, an example is given here in order to give a feeling of this inspiring methodology for registering information about the state of the weather:
Weather – March 2004, Vol. 59, No. 3
M. I. Kyrmitsis S. C. Michaelides
* Publication of this paper should not be taken to represent endorsement by the Royal Meteorological Society.
† Report of surface observation from a fixed land station. ‡ Aviation routine weather report.
Fig. 1 Flow chart contrasting the complex traditional and the simple WeatherAid methodology for monitoring and coding the weather
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Fig. 2 The WeatherAid user interface
ro 1315 tlrr 1525
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r 1400 tlRH 1556
rr 1500 TLR 1614
.
For the experienced user of the approach, the above description is meaningful and essential, as it forms the basis for subsequent coding of the weather, in accordance with specific sets of rules, for international exchange. (It can be translated as: slight rain from 1315, becoming moderate rain at 1400, then continuous moderate rain at 1500, which continued moderate but with moderate thunderstorm from 1525. Moderate thunderstorm continued but with heavy rain and hail from 1556, which changed to heavy thunderstorm with heavy rain from 1614.) For the SYNOP, the observer has to choose from 100 different predefined weather phenomena or combinations for present and recent weather (see Code Table 4677 in WMO 1995) and from a total of 10 for past weather (see Code Table 4561 in WMO 1995). Even more complex is the coding of present and recent weather in meeting the needs of aviation. In the METAR code, the observer is required to build the weather codes not only from the weather phenomena themselves but also from a combination of their intensity, proximity and character (see Code Table 4678 in WMO 1995). The decision for the adoption of the proper codes, which must describe ac-
curately and sufficiently the present, recent and past weather, in accordance with internationally agreed rules, is very demanding and requires the attendance of a skilful observer. Normally, this skill is acquired with formal and ad hoc training lasting a few to several months. The weather observer must be professionally trained to the highest standards: to be always capable of correctly appraising the prevailing weather conditions; to decide appropriately how to describe and register them in accordance with the existing local practice; and finally, to code them in accordance with international rules. However, there is always a possibility that the observer is not familiar with all the possible weather phenomena and the respective coding requirements. In addition, under conditions of rapidly changing weather, the proper and correct recording and subsequent coding can be a stressful task. Monitoring the weather by using Beaufort letters and their subsequent conversion into weather codes can sometimes be quite confusing, especially to the inexperienced observer.
Description of the tool WeatherAid was built as an interactive application running under Windows. The layout of the user interface consists of five parts and is shown in Fig. 2. These parts are (from
top to bottom): the weather description section (occupying the top half ), followed by the date–time display and the controls of the application (the keys and the time scroll bar), the plain-language weather description text box, and the registered entry list. The user does not need to type anything, since the software is fully controlled by the computer’s mouse only. The basic idea behind the application is the development of a practical tool for continuous logging of the evolving weather conditions, simply by choosing from a list of permissible weather phenomena or related supplementary information. The basic structure of the weather description section on the user interface referred to above is the outcome of a detailed tabulation of all the weather phenomena reported by meteorological observers, with respect to both the SYNOP and METAR codes and their subsequent assemblage into three generic groups: Precipitation/Lightning/Thund er, Obscuration, and Other phenomena, as shown in Fig. 2. The idea of having just three generic groups is to simplify the interface and make it particularly user-friendly. In addition, an option for the declaration of observation interruption is available, marking the switching into a latent state in the absence of the observer. In order to avoid disruption to the observer’s attention, an algorithm ‘decides’ which
WeatherAid
Fig. 3 Some of the pop-up windows in the weather description section, guiding the user to declare all the details pertinent to specific weather situations
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option buttons or check boxes (separate or in groups) must exclusively be displayed, in each instance, making the rest inaccessible. In this way, the user is guided by the application to choose the proper combination, by limiting the available choices only to the applicable ones as it is demonstrated in Fig. 3. By pressing the Process key, a plainlanguage weather description is displayed in the relevant text box (see Fig. 2). The translation of the combination of the abstract selections made by the user into a comprehensible description of the weather conditions allows the user to have full control of the weather ‘assemblage’ procedure. WeatherAid operates with the personal computer’s clock being set to GMT. The time is displayed and continuously updated at the top of the user’s interface (see Fig. 2). The continuous surveillance of the weather requires that the exact times of occurrence of any weather changes are registered. The application uses time as a benchmark. The declaration of time is achieved through the appropriate date–time controls on the user interface. WeatherAid allows the user to locate previous entries. Moving between days is achieved by pressing the Today, Previous or Next (day) keys, while the hours and minutes can be selected by using the time scroll bar. By selecting a previous day, the respective day’s database is loaded and the last entry in the list is automatically selected. The first entry in the list is marked as ‘PREV’, denoting the essential link between successive days. Usually, for the registration of a new entry, the first step is pressing the Now key. This action accesses the current day, selects the last entry and sets the time scroll bar to the computer’s present time. The second step is to make changes, if any, in the weather description section, converting the described weather to plain language by pressing the Process key and registering the new entry in present time by pressing the Record key. The new entry is added to the registered entry list. All entries are chronologically ordered. WeatherAid allows modification, adaptation or deletion of previous entries. The modification and adaptation features have a great instructive potential – observers (especially inexperienced ones) can explore previous entries and adapt them to present time. The registered entry list functions dynamically and the procedure for the registration of new entries can be reversed, simply by selecting any entry from the list, as described above. When an entry is selected from the registered entry list, the weather description section, the plainlanguage description text box and the displayed time are updated according to the selected entry. Also, the limits of the time
Fig. 4 The codes window with two columns, one for METAR and one for SYNOP codes
scroll bar are automatically set to one minute after the previous entry and one minute before the next entry. The selected entry can be modified as it concerns its content, its time, or both. If only its content is modified then the revised entry is registered with the same time, replacing the selected one. If only the time is changed then the entry is moved chronologically. If both content and time are changed then a new entry is created before or after the selected entry, accordingly. Entries can also be deleted by pressing the Delete key.
WeatherAid was originally conceived as an electronic alternative for recording the evolving weather conditions. However, the weather description section was designed bearing in mind the information required to define all the weather codes for SYNOP and METAR reports. By reading a registered entry sequence, an intelligent algorithm that embodies all the weather coding procedures produces the proper codes to be reported in both SYNOP and METAR reports. This is achieved simply by pressing the Codes key. The results are displayed in a
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two-column window, as in Fig. 4. The METAR column lists up to three groups for present weather (w¢w¢) and up to three groups for recent weather (REw¢w¢), generated every half-hour. The SYNOP column lists the predominant present or recent weather (ww) and is also generated every half-hour. At main and intermediate synoptic times, the software also generates the past weather codes (W1W2) and up to two weather codes for inclusion in the group for special phenomena (960ww). Finally, WeatherAid has been designed to prepare a daily weather summary that may be used for climatological purposes. By pressing the Summary key, a weather summary is produced and displayed on the computer’s monitor. This daily summary is based on the registered entry list but the times are converted into local standard time to meet national requirements.
Concluding remarks Personal computers are capable of processing meteorological information extremely quickly, and operational meteorology can benefit from the wide availability of this powerful and low-cost hardware. The development of in-house software tools can simplify existing complex procedures, thus reducing considerably the effort and time required for such tasks (see Tandy 1997). By exploiting modern computer technologies, the practice of hand registering and manual coding weather phenomena can be simplified and compiled to the greatest possible extent. The idea is to have an all-in-one, user-friendly application software which not only diminishes the need for a thorough knowledge of existing practices for manually registering weather phenomena and the requirement for familiarity with coding practices, but also can serve as an effective guide in carrying out weather observations. The motivation behind the development of WeatherAid is to provide an intelligent system which would assist the observer in recording the weather conditions efficiently, and in providing the proper weather codes to be used in internationally exchanged weather messages. An Automatic Weather Observing System (AWOS) for the production of several SYNOP and METAR parameters is already in operation at international airports in Cyprus. WeatherAid supplements AWOS as far as the reporting and coding of weather elements is concerned. WeatherAid has been checked against traditional practices and proved to produce the same output. It was built to produce its output according to international standards. Having been tested extensively under all weather conditions, WeatherAid proved to operate correctly. Subsequently, it was officially adopted and integrated into AWOS.
The software can be programmed so that, at fixed times, the weather codes are generated automatically without further intervention from the user. Codes for the present and recent weather (if any) appropriate for inclusion in the METAR are issued every half-hour. Similarly, codes for the weather groups appropriate for inclusion in the SYNOP are issued every three hours. Meteorological observing for synoptic and aviation purposes is a task requiring skill and experience. The development of an electronic tool such as WeatherAid that exploits the potential of personal computers simplifies the procedure and guides the observer in describing the weather conditions properly and accurately. The introduction of WeatherAid into operational use at aerodromes in Cyprus has shown that weather observers have embraced it soon after a basic training, and the new system has replaced the time-consuming traditional weather-monitoring and coding procedures. As a future development, WeatherAid could be adapted for use with battery- or solar light-powered hand-held computers that individual observers could carry as a notepad. WeatherAid can also be used for educational purposes. Indeed, it can be used as a teaching tool for meteorological observers, shortening considerably the training period required. It can be of great assistance to professional meteorological observers but it can also be used as guidance to the individual amateur who is interested in recording, coding or decoding the weather. A large variety of meteorological information is widely published over the Internet (see Brugge 1994, 1995). To take advantage of this easily accessible network, an updated database generated by WeatherAid may be made available for downloading over the Internet, and WeatherAid can subsequently be used as a fully-fledged ‘weather observation viewer’. WeatherAid is available at http://www.cs.ucy.ac.c y/~meteo/Weather Aid.html. Through this web page a users’ manual can also be downloaded and the authors can be contacted by e-mail. In the past three decades, several attempts have been made to computerise some of the weather observer’s functions (see Hill 1975; Strangeways and Smith 1985). Automatic weather observing systems are already operating in many countries, thus enhancing to a large extent the real-time information provided to weather forecasters and also broadening the database available to climatologists and researchers. The exploitation of technology is most welcome, but technology cannot be a substitute for human observation of the weather. In adopting WeatherAid, every effort has been made so that traditional expertise would not be lost. There is no
doubt that the human observation of the weather has inspired many generations of meteorologists, and has laid the foundations and aided the evolution of the science of meteorology. WeatherAid is a tool that exploits current technological advances and aims at facilitating the meteorological observer in carrying out his essential duty of observing the weather. Bearing the above in mind, and also the possibility of a computer failure, the traditional weather logbook has not been abolished completely, but it is maintained and meteorological observers are instructed to carry out at least one full SYNOP and METAR report a day.
Acknowledgements The authors wish to thank the two reviewers for their useful comments in revising the article.
References Brugge, R. (1994) Computer networks and meteorological information. Weather, 49, pp. 298–306 —— (1995) Meteorology and the Internet – current surface weather information. Weather, 50, pp. 387–389 Hill, A. N. (1975) Automated objective observation techniques for “present weather elements”. In: Automated meteorological systems, WMO No. 420, World Meteorological Organization, Geneva, pp. 128–136 Meteorological Office (1982) Observer’s handbook, fourth edition. HMSO Pouncy, F. J. (2003) A history of cloud codes and symbols. Weather, 58, pp. 69–80 Strangeways, I. C. and Smith, S. W. (1985) Development and use of automatic weather stations. Weather, 40, pp. 277–285 Tandy, C. D. (1997) Processing weather data on a personal computer. Weather, 52, pp. 319–322 WMO (1995) Manual on codes. Vol. I, Part A: Alphanumeric codes. World Meteorological Organization, Geneva —— (1998) Manual on codes. Vol. II: Regional codes and national coding practices. World Meteorological Organization, Geneva
Correspondence to: Dr S. C. Michaelides, Meteorological Service, Nicosia 1418, Cyprus. e-mail:
[email protected] © Royal Meteorological Society, 2003. doi: 10.1256/wea.58.03
