Weather Forecasting Group

Group Leader: T. Keenan

Objectives: To improve understanding of mesoscale processes and to develop systems to enhance weather forecasting services.

Research activities

The group is active in mesoscale meteorology research, observational system development, and enhancing the value of numerical weather prediction for the forecast process. It is undertaking significant collaboration with scientists from national and international organisations.

Observational research and development

The BMRC Darwin Climate Monitoring and Research Station (DCMRS) undertook routine data collection in Darwin from November 2003-April 2004 for Ground Validation studies in support of the NASA/NASDA Tropical Rainfall Measuring Mission (TRMM). Observations were coordinated in support of the Atmospheric Radiation Measurement (ARM) program in Darwin.

A range of research activities included validation of TRMM products, analysis of EMERALD-2 data, validation and intercomparison of profiler and polarimetric radar hydrometeor type inferences, studies of the statistical properties and wave generation from tropical convection. Probabilistic and cluster analysis approaches were used to evaluate numerical model simulations of tropical clouds in the Tropical Western Pacific based on ARM and International Satellite Cloud Climatology Project (ISCCP) data. Assessment of the ECMWFreanalysis (ERA40) over the tropical ARM sites was a part of the studies. Single column model simulations are also being employed at the ARM Tropical Western Pacific Sites using various forcing datasets and new modelling techniques.

Significant national and international planning has been a developing activity as part of the proposed Tropical Warm Pool International Cloud Experiment (TWP-ICE) planned for January-February 2006. TWP-ICE will study the morphology and evolution of monsoonal cirrus and the representation of these sub-grid scale processes in numerical models. The contrasts with continental clouds will be an issue and remote sensing, rawinsondes, aircraft and ground-based instruments will be deployed.

System development activities continued with upgrades and conversion to a Linux environment of the control, data acquisition and associated software of the CPOL polarimetric radar. The acquisition of the CP2 polarimetric/dual frequency radar continued from the National Center of Atmospheric Research (NCAR) for research and weather monitoring functions. CP2 will act as a focus for nowcasting, hydrological, satellite validation and severe weather studies in a sub-tropical environment.

Nowcasting research and development

The Nowcasting project mission is to deliver national nowcast systems and procedures for operational use and a focus for these activities is the Radar Network and Doppler Services Upgrade Project (RNDSUP). Applications and systems are being developed to support the delivery of new Doppler services for the Bureau. This work is based on BMRC specific applications e.g. Thunderstorm Interactive Forecast System (TIFS), STEPS but involves collaboration with the National Severe Storm Laboratory (NSSL), using the Warning Decision Support System (WDSS) for severe weather applications, the National Center for Atmospheric Research (NCAR) for storm tracking and the UK MetOffice for hydrological and rainfall algorithms. The aviation industry has also supported the development of nowcasting applications given thunderstorm forecasting requirements in the terminal area of airports.

New development has incorporated improved system administration and diagnostics within the Nowcast server. This Linux server is now undergoing operational trials and includes a rainfall server required for hydrological applications. Collaboration across the Bureau has been underway to define delivery and support mechanisms for RNDSUP applications. Storm cells table displays have been incorporated into 3DRAPIC to provide detailed cell information. Development of the Nowcast Application server system and 3DRAPIC has continued with the delivery of 3DRAPIC V4.23a and V525 (Linux) for operational implementation.

A special issue of Weather and Forecasting devoted to the Sydney 2000 Forecast Demonstration Project of the World Weather Research Programme (WWRP) was published.

Aviation weather research and development

Aviation specific thunderstorm alert products have been generated automatically for the Sydney area based on the TIFS system and will be extended to other capital cities.

The fog and low cloud project aimed at improving our understanding and forecasting capability of fog continued with operational implementation of the national low cloud and fog detection product, including a GOES-9 product on the internal web. Fog forecasting guidance based on LAPS 125 for Perth and LAPS05 for Sydney was refined with verification over the 2003 season undertaken. Further forecasting techniques have been developed for Sydney and show improvement over current techniques. A fog forecasting workshop was conducted to further refine the fog forecasting process making use of operational techniques and BMRC techniques. Initial testing of an interferometer for monitoring of low-level temperature and moisture was undertaken at Melbourne.

The volcanic ash detection project aimed at improving the detection and forecasting of ash dispersion, and streamlining the associated forecast preparation has progressed with the development and release of an initial operational Volcanic Ash Warning Preparation System. On-going operational improvements have focussed on web-based display of the Hysplit plume dispersion and incorporation of GOES-9 data.

Forecast Streamlining and Enhancement (FSEP)

FSEP is a significant activity for the group, involving regular participation in the coordination of FSEP activities and specific projects related to nowcasting, forecasting process and the use of NWP.

The Forecast Information Flows Analysis Project has provided a framework for mapping information flow, streamlining these information flows, and defining the information content of weather service products. Emphasis has been on forecasting rainfall with development of a number of Bayesian decision support networks. This work has been done in collaboration with Monash University through a Linkage grant established by CCSB and through various workshops with a rainfall focus. The aim is to build appropriate decision support networks.

The Thunderstorm Interactive Forecast System (TIFS) has been implemented in the NSW RFC and at the Sydney Airport Meteorological Unit (SAMU) for automated product generation in support of aviation services. It is also been adapted for operational use in Victoria and Queensland with protocols for operational support developed. TIFS has been extended to provide longer lead time products making direct use of the numerically-based National Thunderstorm Guidance System. TIFS now provides a link between nowcasting and short-range forecasting of severe weather. Real time verification, Bayesian decision support and development of multi radar TIFS have also been undertaken.

The model evaluation and use of short-range "Frequent Update NWP" project is investigating ways to improve the use of NWP information in the forecast process. NWP spread diagrams have been developed to provide operational guidance of divergence among medium-range prognoses and to identify source regions for the pattern differences. Frequent data insertion (3 h versus 6 h) approaches have generally shown positive impact on forecasts. As part of the National Thunderstorm and Severe Thunderstorm Forecasting Guidance Project, coding and testing of diagnostic fields was undertaken in liaison with NMOC for operational implementation of the guidance. Objective verification of the diagnostic fields is underway.

Intelligent Alerting is being progressed as an internal project and as part of an Australian Research Council (ARC) Linkage grant in collaboration with RMIT University and Agent Oriented Software (AOS). Trials have been conducted using agent software for detecting and propagating alerts relating to inconsistencies in aviation products, occurrence of volcanic ash, strong winds and locations threatened by storms. The research is exploring dynamic subscriptions, as well as real time interactions between fire events and weather events.

Weather prediction studies and applications

The objective guidance system based on consensus forecasts is now running within NMOC providing guidance for public, aviation and fire weather elements at daily and hourly resolution in real-time. Detailed verification of the daily forecasts has been undertaken and documentation of the method has been completed. Subset verification is now undertaken daily within AIFS. New Model Output Forecast (MOF) coefficients were implemented operationally by NMOC, and description of the new system has been published.

Quantitative precipitation forecasting and verification of rainfall continued. As part of the WMO Working Group on Numerical Experimentation (WGNE) model verification/intercomparison program a Verification Methods web page was developed for the community. Probabilistic precipitation forecasts based on a Poor Man’s Ensemble and the LAPS and GASP ensembles were developed and verified as part of daily runs. Satellite rainfall, which has the potential to improve the Bureau daily rainfall analysis, is also being verified in conjunction with an International Precipitation Working Group (IPWG) project and is being extended to include European and USA domains. High-resolution space-time deterministic precipitation forecasts are being used to generate probabilistic products and have been implemented within operational systems.

BMRC is involved in the Bushfire CRC and is contributing to programs related to fire danger, fire behaviour including smoke plume and haze behaviour. An international fire weather workshop supported by the World Weather Research Program (WWRP) and the CRC was hosted by BMRC during the year as part of this process. New staff joined the group as part of the fire danger program activities of the CRC. Wind-change studies form a significant part of the fire danger program, with relevant climatologies, forecasting products and verification studies being undertaken. High impact events including Ash Wednesday 1983 and the recent Canberra and Alpine fires have been studied and are the subject of papers published this year. The national smoke management advice system to assist fire and emergency agencies responsible for burns, wildfires and hazardous incidents has continued its development and is now operational in all states. A focus has been retaining smoke from continuing burns and inclusion of diurnal variations in plume heights. It is supported by web-based training modules.

Diagnostic weather studies continue to be undertaken on significant and high impact events with emphasis on thunderstorm occurrence. Verification of cool season tornado prediction and probabilistic predictions were investigated. Characteristics of warm season thunderstorms in weakly forced synoptic environments across Australia were compared to those undertaken in the USA and Asia as part of a global investigation promoted by the WWRP.

Hydrological studies and applications

Jointly with the CRCCH at Monash University, the study of the hydrologic balance over the Murray Darling Basin continued as part of a Continental Scale Experiment (CSE) under the Global Energy and Water Cycle Experiment (GEWEX) umbrella. Tests of the land-surface scheme (VB95) continued with soil moisture measurements being compared to model runs.

In collaboration with the Hydrology Branch of the Bureau, focused hydrological research and development has continued. A rainfall server concept was further developed to provide quantitative rainfall estimation and prediction based on radar and rain gauges. This work has been further extended into ensemble-based nowcasting of rainfall combining STEPS and NWP ensemble forecasts. This is being developed jointly with the MetOffice. These nowcasting activities are integrated within the BMRC nowcast server.