Radar Rainfall Calibration Webinar

Dr Alan Seed

Steve Clark

Dr Alan Seed

Alan Seed, Mark Curtis

Rainfields3

The next generation radar rainfall estimation and nowcasting system

Radar network

Radar and gauge coverage in real-time

Rainfields

Rainfields QC/QPE/QPF

50 radars

1700 rain gauges

10 000 products per hour

NWP wet bulb freezing levels

Forecasters

Public weather

Hydrology

NWP assimilation

Rainfields algorithms Climatology Quality Control QPE

Beam blocking

Probability of echo

Topography

Velocity QC

Target identification

Reflectivity QC Bias correction

Gauge blending

Accumulations

Products

• Quality controlled volume scans (QC added to the

volume scan data)

• Surface radar reflectivity for single and multi-radar

domains

• Instantaneous rain rate (used for accumulations and

nowcasts)

• Rainfall accumulations (6 min to 24 h)

• Ensemble forecasts

• 0-12 h, 10 min update over 500 km domains for

Melbourne, Sydney, Brisbane

• 0-90 min, 6 min update, over 50 radar domains

Key requirements • Flexible

– Heterogeneous radar network

– Diverse and customizable product suite

• Scalable

– Up to full network and product suite

– Down to small research deployments

• Low latency

– Near real-time display for forecasters

– Data assimilation into NWP

• Accessible

– Searchable archive for research

– Standardized product formats

Real-time product dashboard

Configurable QC for each radar

Query portal Read

volume Speckle filter

Dealias

VRAD

Classify

targets

Threshold

DHZH

Generate

VAD Write VAD Publish VAD Write volume ...

C++ implementation

XML configuration

Bayes Target Classification

Doppler moment dealiasing • Various window and sweep approaches

• 4D Dealiasing approach compares aliased velocity with prior scan

Echo tracking • Used to simulate 1-minute data when calculating the 6-min accumulations

• Used to correct the different time stamps when making the mosaic

• Used for the nowcasting products

Dynamic radar quality index

Dynamic bias adjustment • Mean bias at each gauge is monitored

• Real-time adjustment updated using Kalman filter every 30 mins

• Spatial field estimated using Ordinary Kriging every 30 mins

Verification

• 30min gauge versus 30min

radar

• Based on bias corrected

accumulations

– Not gauge merged

• 4 window lengths

– 7, 30, 120 and 365 day

• Updated daily

Mean Error Time Series

Multi-radar mosaic • Use the quality index to calculate the weights for a mosaic product

Typical products

Rainfields3 Summary • Rainfields3 is the next generation operational radar rainfall estimation and

nowcasting system

– Will be fully operational by July 2017

– Processes data from 50 radars

– Uses the STEPS algorithms to generate 30-member nowcast ensemble for

each of the 50 radars (6 min updates)

– Generates 10000 QPE&QPF products an hour

Thank you

Any questions

What is the problem…..

Calibrated RADAR Rainfall Data – A Comparison with Traditional Techniques

Greg Hansell

Water Technology Pty Ltd

Presented at 21st Queensland Water Symposium, 2016

Further contributors include Alister Daly, Andrew Thompson, Blair Filer and Chris Delany

• How does Calibrated RADAR compare to traditional techniques for the January 2011 event:

• Stanley River

• Lockyer Valley

• Murphy’s Creek

• Implications for catchment hydrology

Mt Stapylton RADAR ImageJan 2011 (Source – BoM)

Background

• Thesis project underway by Chris Delany

• Total catchment ~3,000km2 in area

• ~370km2 Murphy’s Creek

• 38 Council rain gauges

• Only 1 in Murphy’s Creek

• ~2-3 day event duration

Analysis

• Fresh TUFLOW build

• Rain on Grid (Inverse Distance Weighting)

with traditional gauge and RADAR input

• Work in progress, however preliminary results

look promising…

Lockyer Valley Case Study Spatial Comparison

Murphy’s Creek: Spatial Comparison

Murphy’s Creek: Hydraulic Model Comparison

Conclusions – Calibrated RADAR Rainfall data

• RADAR - New and innovative approach

• RADAR compares well to traditional catchment hydrology approaches where gauge data is available

• RADAR may provide enhanced results where gauge data is limited/poor

• Effectively turns every 1km2 grid into a “rain gauge”

• Provides complete rainfall catchment coverage (versus rain gauges only)

• Can be enhanced: -

• With inclusion of other rain gauges (HydroNET can do this);

• Optimum calibration outcome

=> Further source of information=> Can add value to hydrologic assessments

http://www.hydronet.com.au/

What is RainMap?• Easy online access to:

– BoM weather forecasts

– BoM weather stations

– BoM radar data

• Tools to enable water professionals– Export to model input files

– Upload shape files for catchment averages

– Generate rainfall reports

– Download long time series

– Access to data back to 1900

How widely is the HydroNet Platform Used?

• 2500 water managers world wide use the radar tools of HydroNET

• These tools are now tailored for the Australian situation during the ESA project in cooperation with 10+ Queensland councils.

What do HydroNet offers……

• We buy the radar data from BoM,

• archive it in the cloud and

• translate it into tools for water managers so that they can easily use radar data for operational and strategic water management: whenever and wherever.

• You just need a web browser.

Upcoming seminars

• The same can be done with forecasts…

More informationwww.hydronet.com.auwww.watertech.com.au

Examples of tools that RainMap provides

• exports into platform agnostic (Tuflow, Mike etc) models for model calibration,

• export to Word document to evaluate rainfall events,

• upload your own catchments to calculate catchment averages, download time series in excel or model formats,

• automatic exports to your databases/systems,

• export to your website to share with the community, we archive it for you

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