Our People

Jeff Kepert
Project Leader
Key interests:

About

My main research interests are divided between data assimilation and tropical cyclones, with a focus on the marine boundary layer in both areas.

In data assimilation, I was responsible for implementing the use of scatterometer data from the QuikScat instrument in the Bureau's operational global NWP system [paper]. In conjunction with this, I lead a major study which used the QuikScat data to validate the near-surface winds in the entire NWP suite [research report] [paper].

I have also investigated formulation details of the Ensemble Kalman Filter, a relatively new assimilation method with considerable potential. Specific projects include (i) an examination of the implications of using perturbed observations to estimate the observation-error covariance [paper] and (ii) an examination of the implications for balance of covariance localisation, and the development of a new method of localisation with much improved balance properties .

Wind energy is a renewable source of energy with a gradually increasing presence in Australia. A major factor impeding the more extensive use of wind power is that the wind is highly variable, leading to large fluctuations in electricity output and hence a difficulty in incorporating these power sources within the electricity grid. I have been closely involved in the development within BMRC of a new high-resolution NWP system, WLAPS, developed partly to improve the Bureau's ability to support forecasting of wind power production. The main innovation in this system is that it assimilates at the native model resolution of 10 km. Extensive verification has demonstrated that WLAPS produces significantly superior forecasts to its predecessors.

Recent tropical cyclone work has focussed on the structure of the boundary layer winds, especially the dynamics and characteristics of the low-level jet that is often found near the top of the boundary layer, and the factors that determine the strength of the surface winds relative to those aloft. The approach has been a mix of analytical modelling, numerical modelling, and the analysis of observations, including detailed case studies of the flow and balance in Hurricanes Georges and Mitch using data obtained by the NOAA Hurricane Research Division from the GPS dropsonde. These analyses required very accurate location of the cyclone centre, leading to the development of an objective new method for finding the centre of a storm using asynoptic mass data. Currently, I am attempting to better understand the turbulent structure of the tropical cyclone boundary layer, using dropsonde data .

Earlier work on air-sea interaction at high wind speeds included a demonstration of the roles of sea spray and rain evaporation in the thermodynamics of the TCBL, using a slab model which included parameterisations of these effects together with cloud downdrafts, clear sky and surface fluxes. I also used a turbulent closure model coupled to a spray dispersion and evaporation model to explore the transport and transformations of saline droplets in the full atmospheric boundary layer, and to refine bulk parameterisations of these effects. A major experimental project, instrumenting two 300 m towers on the tip of North West Cape, Western Australia, to make detailed boundary layer measurements during a tropical cyclone passage, ended in 2002.

More info:

Project leadership

This project is using high-resolution modelling, together with a range of meteorological data, to better understand and predict important meteorological natural hazards, including fire weather, tropical cyclones, severe thunderstorms and heavy rainfall. The outcomes from the project will contribute to reducing the impact and cost of these hazards on people, infrastructure, the economy and the environment.
Research team:
This research into interactions with topography, potential for pyro-convection, potential for three dimensional interactions, potential for winds to change substantially around a fire, water vapour dry slots, plume development and spotting process will be integrated into a formal, quantitative system for use with the current fire forecasting system.

Lead end user

This study is identifying the thresholds beyond which dynamic fire behaviour becomes a dominant factor, the effects that these dynamic effects have on the overall power output of a fire, and the impacts that such dynamic effects have on fire severity. This will necessarily include consideration of other factors such as how fine fuel moisture varies across a landscape. The research team is investigating the conditions and processes under which bushfire behaviour undergoes major transitions, including fire convection and plume dynamics, evaluating the consequences of eruptive fire behaviour (spotting, convection driven wind damage, rapid fire spread) and determining the combination of conditions for such behaviours to occur (unstable atmosphere, fuel properties and weather conditions).
Research team:
Year Type Citation
2017 Report Kepert, J. D. et al. Improved predictions of severe weather to reduce community impact: midterm report 2014-17. (Bushfire and Natural Hazards CRC, 2017).
2017 Journal Article Thurston, W., Kepert, J. D., Tory, K. J. & Fawcett, R. J. B. The contribution of turbulent plume dynamics to long-range spotting. International Journal of Wildland Fire 26, 317-330 (2017).
2017 Report Kepert, J. D., Peace, M. & Ye, H. Coupled fire-atmosphere modelling project: annual project report 2016-17. (Bushfire and Natural Hazards CRC, 2017).
2017 Conference Paper Peace, M. et al. Lessons learned from a multidisciplinary investigation into the Waroona fire. AFAC17 (Bushfire and Natural Hazards CRC, 2017).
2017 Conference Paper Tory, K. J., Thurston, W. & Kepert, J. D. Thermodynamic considerations of pyrocumulus formation. AFAC17 (Bushfire and Natural Hazards CRC, 2017).
2017 Conference Paper Kepert, J. D. Secondary eyewall formation in tropical cyclones. AFAC17 (Bushfire and Natural Hazards CRC, 2017).
2017 Journal Article Kepert, J. D. Time and space scales in the tropical cyclone boundary layer, and the location of the eyewall updraft. Journal of the Atmospheric Sciences (2017). doi:10.1175/JAS-D-17-0077.1
2016 Conference Paper Thurston, W., Tory, K. J., Fawcett, R. J. B. & Kepert, J. D. Large-eddy simulations of pyro-convection and its sensitivity to mositure. 5th International Fire Behaviour and Fuels Conference (International Association of Wildland Fire, 2016).
2016 Report Kepert, J. D. et al. Improved predictions of severe weather to reduce community impact: Annual project report 2015-2016. (Bushfire and Natural Hazards CRC, 2016).
2016 Conference Paper Thurston, W., Tory, K. J., Fawcett, R. J. B. & Kepert, J. D. The effects of turbulent plume dynamics on long-range spotting. AFAC16 (Bushfire and Natural Hazards CRC, 2016).
2016 Report Kepert, J. D. & Peace, M. Coupled fire-atmosphere modelling: Annual project report 2015-2016. (Bushfire and Natural Hazards CRC, 2016).
2016 Conference Paper Ching, S., Fawcett, R. J. B., Thurston, W., Tory, K. J. & Kepert, J. D. Mesoscale features related to the Blue Mountains fires of 17 October 2013 revealed by high resolution Numerical Weather Prediction (NWP) modelling. 5th International Fire Behaviour and Fuels Conference (International Association of Wildland Fire, 2016).
2016 Journal Article Peace, M., Mattner, T., Mills, G. A., Kepert, J. D. & McCaw, L. Coupled fire-atmosphere simulations of the Rocky River fire using WRF-SFIRE. Journal of Applied Meteorology and Climatology 55, (2016).
2016 Conference Paper Thurston, W., Tory, K. J., Fawcett, R. J. B. & Kepert, J. D. Long-range spotting by bushfire plumes: The effects of plume dynamics and turbulence on firebrand trajectory. 5th International Fire Behaviour and Fuels Conference (International Association of Wildland Fire, 2016).
2015 Conference Paper Thurston, W., Tory, K. J., Kepert, J. D. & Fawcett, R. J. B. The Effects of Fire-Plume Dynamics on the Lateral and Longitudinal Spread of Long-Range Spotting Conference Paper 2014. Bushfire and Natural Hazards CRC and AFAC Wellington Conference 2014 (2015).
2015 Presentation Kepert, J. D. & Peace, M. Coupled Fire-Atmosphere Modelling. (2015).
2015 Conference Paper Kepert, J. D., Naughton, M. & Bally, J. Managing Severe Weather - Progress and Opportunities Conference Paper 2014. Bushfire and Natural Hazards CRC and AFAC Wellington Conference 2014 (2015).
2015 Conference Paper Fawcett, R. J. B., Yeo, C., Thurston, W., Kepert, J. D. & Tory, K. J. Modelling the Fire Weather of the Coonabarabran Fire of 13 January 2013. Bushfire and Natural Hazards CRC and AFAC Wellington Conference 2014 (2015).
2015 Conference Paper Dharssi, I., Kumar, V., Yeo, C., Bally, J. & Kepert, J. D. Mitigating the Effects of Severe Fires, Floods and Heatwaves Conference Paper 2014. Bushfire and Natural Hazards CRC and AFAC Wellington Conference 2014 (2015).
2015 Conference Paper Foley, M., Peace, M., Griffiths, D., Sofra, J. & Kepert, J. D. The Sydney 2014 forecast demonstration project - a step from research to operations - non peer reviewed extended abstract. Adelaide Conference 2015 (2015).
2015 Conference Paper Thurston, W., Tory, K. J., Fawcett, R. J. B. & Kepert, J. D. Large-eddy simulations of pyro-convection and its sensitivity to environmental conditions - peer viewed. Adelaide Conference 2015 (2015).
2015 Journal Article Thurston, W., Fawcett, R. J. B., Tory, K. J. & Kepert, J. D. Simulating boundary-layer rolls with a numerical weather prediction model. Quarterly Journal of the Royal Meteorological Society 1-14 (2015). at <http://www.cawcr.gov.au/staff/jdk/Kepert_papers/Thurston_etal_2015_qjrms_acc.pdf>
2015 Presentation Kepert, J. D., Thurston, W., Ching, S., Tory, K. J. & Fawcett, R. J. B. Improved predictions of severe weather to reduce community risk. (2015).
2014 Report Yeo, C., Kepert, J. D. & Hicks, R. Fire Danger Indices: Current Limitations and a Pathway to Better Indices. (Bushfire and Natural Hazards CRC, 2014).
2013 Conference Proceedings Kepert, J. D., Fawcett, R. J. B., Tory, K. J. & Thurston, W. Applications of Very High Resolution Atmospheric Modelling for Bushfires. 2013 Research Forum (2013). at <http://www.bushfirecrc.com/resources/research-report/applications-very-high-resolution-atmospheric-modelling-bushfires>
2013 Conference Paper Thurston, W., Tory, K. J., Fawcett, R. J. B. & Kepert, J. D. Large-eddy simulations of bushfire plumes in the turbulent atmospheric boundary layer. 20th International Congress on Modelling and Simulation (2013).
2013 Journal Article Fawcett, R. J. B., Wain, A., Thurston, W., Kepert, J. D. & Tory, K. J. A comparison of the fire weather characteristics of the Melbourne dust storm (1983) and Black Saturday (2009): a high-resolution ACCESS case study. 20th International Congress on Modelling and Simulation 167-172 (2013). at <http://www.mssanz.org.au/modsim2013/A3/fawcett.pdf>
2013 Conference Proceedings Fawcett, R. J. B., Thurston, W., Kepert, J. D. & Tory, K. J. The Eyre Peninsula Fire of 11 January 2005: an ACCESS case study. 2013 Research Forum (2013). at <http://www.bushfirecrc.com/resources/research-report/eyre-peninsula-fire-11-january-2005-access-case-study>

Posters credited

Improved predictions of severe weather to help reduce community impact


To improve our understanding of and ability to predict severe weather, including for bush fires, tropical cyclones, severe thunderstorms and heavy rainfall, through the use of high-resolution modelling in conjunction with available observations. 

Fire danger indices: Current limitations and a pathway towards better indices


To identify potential new candidate Fire Weather Indices (FWIs) for a New Fire Danger Ratings System.

Mitigating the effects of severe fires, floods and heatwaves through the improvements of land dryness measures and forecasts


This project will improve Australia’s ability to manage extreme events by developing a state of the art, world’s best practice in soil moisture analysis.

The effects of fire plume dynamics on the lateral and longitudinal spread of long-range spotting


High-resolution numerical modelling is used to explore how the dynamics of bushfire plumes under different wind conditions can modify: (1) The distance travelled by firebrands, and (2) The spread in landing positions of firebrands. 

Weather Science to Societal Impact: Opportunities for Australia in the World Meteorological Organisation's High Impact Weather Project


The Bureau of Meteorology seeks Australian collaborators to participate in a new 10-year international high impact weather project to develop improved hazard prediction capabilities. Its aims align on an international level with those of the Bushfire and Natural Hazards CRC.

Modelling the Fire Weather of the Blue Mountains Fires of October 2013


High resolution simulations over the Blue Mountains Region on 17 October 2013 show several interesting meteorological features.

Meteorology of the Sampson Flat Fire in January 2015


In January 2015, the Sampson flat bushfire burnt in the Adelaide hills. it was active for 6 days, burning 12,500 ha, 27 homes, numerous sheds and 900 animals. This study focuses on the meteorological conditions on the day of ignition Friday 2 January. the major fire run occurred the following day.

Key Topics:
Long-Range Spotting by Bushfire Plumes: The Effects of In-Plume Turbulence on Firebrand Trajectory


Large-eddy simulations of bushfire plumes are combined with firebrand trajectory calculations to estimate the effects of in-plume turbulence on firebrand transport.  In-plume turbulence  substantially lengthens the maximum spotting distance AND increases the lateral and longitudinal spread of firebrand landing positions.

Will Thurston Conference Poster 2016


Pyrocumulonimbus clouds have been linked to highly dangerous fire behaviour.

Mika Peace Conference Poster 2016


Coupled fire-atmosphere models show three-dimensional interactions between a fire and the surrounding atmosphere.

Pages

Resources credited

Type Released Title Download Key Topics
Presentation-Slideshow 21 Mar 2014 Improved predictions of severe weather to reduce community impact PDF icon Save (2.77 MB) risk management, severe weather, warnings
Presentation-Slideshow 08 Sep 2014 Modelling the fire weather of the Coonabarabran fire of 13 January 2013 PDF icon Save (10.08 MB) fire weather, modelling
Presentation-Slideshow 08 Sep 2014 The effects of fire plume dynamics on the lateral and longitudinal spread of long-range spotting PDF icon Save (2.25 MB) fire, fire impacts
Presentation-Slideshow 08 Sep 2014 Managing severe weather - progress and opportunities PDF icon Save (2.61 MB)
Presentation-Audio-Video 20 Oct 2014 Managing severe weather - progress and opportunities risk management, severe weather
22 Oct 2014 Managing severe weather: progress and opportunities forecasting, risk management, severe weather
Presentation-Audio-Video 27 Oct 2014 The effects of fire-plume dynamics on the spread of long range spotting fire, modelling
Presentation-Slideshow 02 Sep 2015 The Sydney 2014 Forecasting Demonstration Project A Step from Research to Operations PDF icon Save (1.27 MB) fire impacts, fire weather, severe weather
Presentation-Slideshow 11 Sep 2015 Large-eddy simulations of pyro-convection and its sensitivity to environmental conditions PDF icon Save (1.24 MB) environments, fire weather, modelling
Presentation-Audio-Video 03 Apr 2016 Monitoring and prediction - cluster overview File Save (0 bytes) forecasting, multi-hazard, scenario analysis
Presentation-Slideshow 30 Aug 2016 Why use ensemble prediction? - Jeff Kepert PDF icon Save (4.81 MB) fire weather, forecasting, severe weather
Presentation-Slideshow 30 Aug 2016 The effects of turbulent plume dynamics on long-range spotting - Will Thurston PDF icon Save (2.56 MB) fire, fire severity, fire weather
Presentation-Slideshow 24 Oct 2016 Improved predictions of severe weather to reduce community risk PDF icon Save (9.18 MB) forecasting, modelling, severe weather
Presentation-Slideshow 24 Oct 2016 Coupled fire-atmosphere modelling project PDF icon Save (2.46 MB) fire severity, fire weather, modelling
HazardNoteEdition 25 Oct 2016 Next generation fire modelling PDF icon Save (1.35 MB) fire impacts, fire severity, fire weather
HazardNoteEdition 28 Nov 2016 Monitoring and predicting natural hazards PDF icon Save (853.18 KB) forecasting, modelling, severe weather
HazardNoteEdition 12 Dec 2016 Fire escalation by downslope winds PDF icon Save (1.08 MB) fire impacts, fire severity, fire weather
Presentation-Slideshow 07 Jul 2017 Building bushfire predictive services capability PDF icon Save (9.97 MB) fire, fire weather, modelling
Presentation-Slideshow 07 Jul 2017 Lightning presentation: improved predictions of severe weather PDF icon Save (2.59 MB) communication, fire weather, severe weather
Presentation-Slideshow 07 Sep 2017 Secondary eyewall formation in tropical cyclones PDF icon Save (1.04 MB) cyclone, severe weather, tropical
Presentation-Slideshow 07 Sep 2017 Thermodynamics of pyrocumulus formation PDF icon Save (2.79 MB) fire, fire weather, severe weather
Presentation-Slideshow 31 Oct 2017 Impact forecasting: introducing a new project for 2017-19 PDF icon Save (1.13 MB) emergency management, forecasting, severe weather
Presentation-Slideshow 31 Oct 2017 Improved predictions of severe weather to reduce community impact PDF icon Save (1.93 MB) forecasting, mitigation, severe weather
Presentation-Slideshow 31 Oct 2017 Coupled fire-atmosphere modelling project: ACCESS-Fire PDF icon Save (580.38 KB) fire, fire weather, modelling
Presentation-Audio-Video 16 Apr 2018 Forecasting Impact for Severe Weather PDF icon Save (1.61 MB) coastal, forecasting, severe weather
HazardNoteEdition 14 Jun 2018 Extreme fire behaviour: reconstructing the Waroona fire pyrocumulonimbus and ember storms PDF icon Save (420.52 KB) fire impacts, fire severity, fire weather