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Guidelines on Ensemble Prediction Systems and Forecasting
Ensemble Prediction Systems (EPS) are numerical weather prediction (NWP) systems that allow us to estimate the uncertainty in a weather forecast as well as the most likely outcome. Instead of running the NWP model once (a deterministic forecast), the model is run many times from very slightly different initial conditions. Often the model physics is also slightly perturbed, and some ensembles use more than one model within the ensemble (multi-model EPS) or the same model but with different combinations of physical parameterization schemes (multi-physics EPS). Owing to the cost of running ...
PWS, 24. Guidelines on the strategies for use of social media by National Meteorological and Hydrological Services
Increasingly, Social Media meet the information needs of individuals and communities. Social Media provide enormous opportunities for National Meteorololgical and Hydrological Services (NMHSs) to enhance the delivery of information and services and to interact with users to better understand their needs and interests. The purpose of these Guidelines is to assist NMHSs who may be considering the use of Social Media. The Guidelines address the challenges and highlight the benefits of Social Media, suggest some principles for an effective strategy, and encourage NMHSs to consider Social Media as ...
PWS, 23. Proceedings of the WMO Regional Association VI Conference on Social and Economic Benefits of Weather, Climate and Water Services
The Conference provided material, and, in particular, a number of studies which are contained in these proceedings and which will be used in the development of guidelines on undertaking the analysis, assessment and demonstration of socio-economic benefits of meteorological and hydrological services. These guidelines will complement the development of demonstration and pilot projects and capacity-building and training activities on this subject. These proceedings represent the collection of abstracts of papers delivered at the Conference.
WWRP, 2012-1. Recommended Methods for Evaluating Cloud and Related Parameters
World Meteorological Organization (WMO) ; WWRP/WGNE Joint Working Group on Forecast Verification Research (JWGFVR) - WMO, 2012Cloud errors can have wide-reaching impacts on the accuracy and quality of outcomes, most notably, but not exclusively, on temperature. This is especially true for weather forecasting, where cloud cover has a significant impact on human comfort and wellbeing. Whilst public perception may not be interested in absolute precision, i.e. whether there were 3 or 5 okta of cloud, there is anecdotal evidence to suggest strong links between the perceptions of overall forecast accuracy and whether the cloud was forecast correctly, mostly because temperature errors often go hand-in-hand. It is therefore ...
JCOMM Technical Report, 57. Extreme value analysis: wave data
World Meteorological Organization (WMO) ; Intergovernmental Oceanographic Commission (IOC) - WMO, 2011In this report we begin by describing and discussing approaches that can be used to estimate such return values in Chapter 2. Approaches based on extreme value theory as well as ad hoc methods are considered. We then present in Chapter 3 some worked examples using two time series of significant wave height measurements, one in deep and the other in shallow waters. In Chapter 4 we provide an inventory of software packages available to carry out extreme value analyses. We finish in Chapter 5 with some guidelines / recommendations.
JCOMM Technical Report, 58. Extreme value analysis: still water level
World Meteorological Organization (WMO) ; Intergovernmental Oceanographic Commission (IOC) - WMO, 2011In this report we begin by describing and discussing approaches based on extreme value theory that can be used to estimate return values of SWL in Chapter 2. We then present in Chapter 3 a worked example using a long-term time series of still water level measurements processed and quality-checked by the Dutch Ministry of Transport, Public Works and Water Management. They are the measurements of the gauge located at Hoek van Holland, The Netherlands (see Figure 3.1), available from 1887 onwards. In Chapter 4 we provide an inventory of software packages available to carry out extreme value analy ...
Contributions by the World Meteorological Organization to the Millenium Development Goals
For developing countries, particularly LDCs (Least Developed Countries), this publication provides guidelines on enhancing the contribution of WMO and NMHSs (National Meteorological and Hydrological Services) to the achievement of the MDGs (Millenium Development Goals). Benefiting from the GFCS (Global Framework for Climate Services), NMHSs should be encouraged to use these guidelines, among others, to mainstream their activities, including generation and effective delivery of relevant weather-, climate- and water-related information and services into national sustainable development strategie ...
PWS, 22. Guidelines on international and cross-border collaboration in the warning process
This document provides guidelines on international collaboration in the warning process for severe weather threats and extreme conditions (heat wave, cold wave, drought, storm surge, avalanches, flooding.) It discusses general principles regarding cross-border exchange of warnings, and includes the role of the media in raising the public’s expectations, focus on public safety, threshold criteria and the scope of cooperation. It also presents examples from different parts of the world to illustrate the factors to be considered in developing international or cross-border collaborations in the wa ...
GAW Report, 191. Instruments to Measure Solar Ultraviolet Radiation : part 4: Array Spectroradiometers
World Meteorological Organization (WMO) ; Bais A.; Bernhard G.; et al. - WMO, 2010 (WMO/TD-No. 1538)This paper is part four of a series of documents dedicated to instruments for the measurement of solar ultraviolet radiation. The series of documents has been drawn up by the WMO Scientific Advisory Group on UV Monitoring and the UV Instrumentation Subgroup. The aim of the series is to define instrument specifications and guidelines for instrument characterization that are needed for reliable UV measurements.
PWS, 21. Guidelines on early warning systems and application of nowcasting and warning operations
In 2010, a historic heat wave and numerous wildfires impacted Moscow and surrounding areas in the Russian Federation. At the same time, catastrophic flooding from unusually heavy monsoon rains was ongoing in Pakistan. Both events led to many fatalities and considerable human suffering. As climate change due to anthropogenic forcing continues, extreme weather events such as these are likely to become more common (IPCC 2007), further increasing the need for preparedness and early warning systems.
The need for robust early warning systems goes beyond purely natural disasters and extend ...
Guidelines for converting between various wind averaging periods in tropical cyclone conditions
World Meteorological Organization (WMO) ; Kepert Jeffrey David; Ginger J.D. - WMO, 2010 (WMO/TD-No. 1555)
GAW Report, 192. Guidelines for the Measurement of Atmospheric Carbon Monoxide
The Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO) aims at providing reliable long-term observations of the chemical composition and physical properties of the atmosphere that are relevant for understanding atmospheric chemistry and climate change. Reactive gases are one of the foci of the GAW programme. This group includes carbon monoxide (CO), which is present only in trace quantities in the atmosphere but plays an important role in atmospheric chemistry. Compatibility of data from different observational platforms and sites is of crucial importance fo ...
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