
David Flack developed and maintained core diagnostics, data processing, and visualization features for the MetOffice/CSET repository over ten months. He engineered robust Python-based pipelines for meteorological and climate data, introducing new operators for time aggregation, ensemble analysis, and probability visualization. His work included workflow automation, configuration management, and extensive test-driven development, ensuring reliability and scalability for production runs. David improved data ingestion by unifying recipe loaders and enhanced visualization fidelity through colorbar and plotting logic refinements. Leveraging Python, YAML, and Cylc, he delivered maintainable, well-documented solutions that streamlined model evaluation, accelerated feature delivery, and improved analyst productivity.

October 2025 highlights for MetOffice/CSET: Delivered two flagship diagnostics enabling end-to-end model evaluation: Model Temperature Spatial Difference Diagnostics and Fog Presence Diagnostics with Data Loading. Completed workflow integration and configuration templates, improving production readiness and analyst productivity.
October 2025 highlights for MetOffice/CSET: Delivered two flagship diagnostics enabling end-to-end model evaluation: Model Temperature Spatial Difference Diagnostics and Fog Presence Diagnostics with Data Loading. Completed workflow integration and configuration templates, improving production readiness and analyst productivity.
September 2025 performance summary for MetOffice/CSET, focusing on robust data ingestion, extended timeseries support, and enhanced probability visualization that collectively improve reliability, speed, and decision-ready insight. Key features delivered and business value: - Unified Python recipe loader: Converted include files for timeseries, spatial_difference, profile, transect, histogram, and ageofair into the Python recipe loader, enabling a single, testable ingestion pathway across core data products. This reduces maintenance burden and accelerates on-boarding of new datasets. - Timeseries delivery and handling: Added a timeseries recipe and loader, with domain mean timeseries adjustments and removal of domain-average timeseries for probabilistic workflows. Result: more accurate, domain-aware timeseries representations and faster recipe execution. - Expanded probability handling and visualization: Introduced a top-level selector for probabilities at screen level temperature, updated colorbars (two-decimal precision for 1% probabilities), a spatial_field loader for probabilities without a control member, and targeted diagnostics for probability cases, improving diagnosability and user insight. - Stability, quality, and structure improvements: Moved base_model inside if loops in the recipe loader; removed spatial_difference includes; normalized model_ids to lists; preserved colorbars by improving unit handling; updated workflow/rose configuration and directory structures to support new probability-related recipes; comprehensive typo and varname fixes to improve clarity and reduce errors. - Testing, docs, and governance: Added tests for updated collapse.py and colorbar/probability paths; updated GUI and recipe documentation; expanded documentation coverage across collapses, recipes, and general docs; ensemble categorization updates to align outputs with user expectations. Overall impact: Strengthened data ingestion reliability, accelerated feature delivery for probabilistic analyses, improved visualization fidelity, and enhanced maintainability and transparency of the data pipeline. These changes enable faster, more trustworthy insights for critical weather and climate decision-making. Technologies/skills demonstrated: Python, data ingestion pipelines, recipe loader architecture, timeseries processing, probability handling, visualization tuning (colorbars and units), test-driven development, directory restructuring, and documentation governance.
September 2025 performance summary for MetOffice/CSET, focusing on robust data ingestion, extended timeseries support, and enhanced probability visualization that collectively improve reliability, speed, and decision-ready insight. Key features delivered and business value: - Unified Python recipe loader: Converted include files for timeseries, spatial_difference, profile, transect, histogram, and ageofair into the Python recipe loader, enabling a single, testable ingestion pathway across core data products. This reduces maintenance burden and accelerates on-boarding of new datasets. - Timeseries delivery and handling: Added a timeseries recipe and loader, with domain mean timeseries adjustments and removal of domain-average timeseries for probabilistic workflows. Result: more accurate, domain-aware timeseries representations and faster recipe execution. - Expanded probability handling and visualization: Introduced a top-level selector for probabilities at screen level temperature, updated colorbars (two-decimal precision for 1% probabilities), a spatial_field loader for probabilities without a control member, and targeted diagnostics for probability cases, improving diagnosability and user insight. - Stability, quality, and structure improvements: Moved base_model inside if loops in the recipe loader; removed spatial_difference includes; normalized model_ids to lists; preserved colorbars by improving unit handling; updated workflow/rose configuration and directory structures to support new probability-related recipes; comprehensive typo and varname fixes to improve clarity and reduce errors. - Testing, docs, and governance: Added tests for updated collapse.py and colorbar/probability paths; updated GUI and recipe documentation; expanded documentation coverage across collapses, recipes, and general docs; ensemble categorization updates to align outputs with user expectations. Overall impact: Strengthened data ingestion reliability, accelerated feature delivery for probabilistic analyses, improved visualization fidelity, and enhanced maintainability and transparency of the data pipeline. These changes enable faster, more trustworthy insights for critical weather and climate decision-making. Technologies/skills demonstrated: Python, data ingestion pipelines, recipe loader architecture, timeseries processing, probability handling, visualization tuning (colorbars and units), test-driven development, directory restructuring, and documentation governance.
Month: 2025-08 — MetOffice/CSET: Delivered a focused set of feature-rich enhancements and reliability fixes across diagnostics, data processing, and visualization, with strong testing and documentation coverage. Highlights include: Derived diagnostics naming and structure (renaming process-based diagnostics to derived, placeholders for new sections, clearer naming), Generate_mask cubelist support (cubelist handling and related cube rename, with tests for cubelist), Rain presence diagnostics and workflow integration (recipes and workflow wiring updated), Daily maximum temperature plotting and workflow integration (recipes and plotting added for daily max temp with constraints and tests), and Mask colorbar handling improvements (colorbar updates and tests). These changes improve maintainability, flexibility in data processing, forecast visualization, and reduce risk through tests and documentation updates.
Month: 2025-08 — MetOffice/CSET: Delivered a focused set of feature-rich enhancements and reliability fixes across diagnostics, data processing, and visualization, with strong testing and documentation coverage. Highlights include: Derived diagnostics naming and structure (renaming process-based diagnostics to derived, placeholders for new sections, clearer naming), Generate_mask cubelist support (cubelist handling and related cube rename, with tests for cubelist), Rain presence diagnostics and workflow integration (recipes and workflow wiring updated), Daily maximum temperature plotting and workflow integration (recipes and plotting added for daily max temp with constraints and tests), and Mask colorbar handling improvements (colorbar updates and tests). These changes improve maintainability, flexibility in data processing, forecast visualization, and reduce risk through tests and documentation updates.
July 2025 – MetOffice/CSET: Delivered a broad set of ensemble plotting enhancements and stability fixes that improve visualization quality, reliability, and performance. Key deliverables include memory optimizations for ensemble plotting, support for multi-line ensemble traces, and robust legend/coordinate handling that clearly distinguishes ensemble data from single-member runs. In addition, plotting order and coordinate logic were corrected for both ensemble and deterministic runs, and labeling was moved into the plotting loop to reduce overhead. Expanded testing and documentation underpin ongoing quality: new tests for ensemble timeseries and profiles, plus updated recipe/plot descriptions on the website. These changes reduce memory footprint, accelerate rendering, improve decision confidence, and strengthen developer experience through pre-commit fixes and clearer documentation.
July 2025 – MetOffice/CSET: Delivered a broad set of ensemble plotting enhancements and stability fixes that improve visualization quality, reliability, and performance. Key deliverables include memory optimizations for ensemble plotting, support for multi-line ensemble traces, and robust legend/coordinate handling that clearly distinguishes ensemble data from single-member runs. In addition, plotting order and coordinate logic were corrected for both ensemble and deterministic runs, and labeling was moved into the plotting loop to reduce overhead. Expanded testing and documentation underpin ongoing quality: new tests for ensemble timeseries and profiles, plus updated recipe/plot descriptions on the website. These changes reduce memory footprint, accelerate rendering, improve decision confidence, and strengthen developer experience through pre-commit fixes and clearer documentation.
June 2025 monthly summary for MetOffice/CSET: Stabilized CSET execution by correcting model field processing and enhancing reliability of end-to-end runs. Focused on delivering business value through faster verification, reduced downtime, and robust field handling across pipelines.
June 2025 monthly summary for MetOffice/CSET: Stabilized CSET execution by correcting model field processing and enhancing reliability of end-to-end runs. Focused on delivering business value through faster verification, reduced downtime, and robust field handling across pipelines.
This month delivered robust data normalization and workflow optimizations for MetOffice/CSET, enabling more reliable cross-source processing and scalable execution of the data pipelines. Key fix: standardized model_level_number across data sources with a renaming callback and regression test to guarantee consistency in downstream merges. Major tuning: CSET workflow resource and timing adjustments to improve scalability, reliability, and resource utilization. Memory budgets were increased (aggregation memory limit to 100 GB, per-process memory increased by 1 GB, and process family memory adjustments), walls clock extended to PT2H for aggregation, and directives centralized in flow.cylc with aggregation-focused directives. Overall impact: more robust merges across diverse data sources, reduced runtime variability, and a foundation for handling larger datasets in production. Skills demonstrated: data standardization, testing, Cylc workflow orchestration, memory and performance tuning, and cross-source data integration.
This month delivered robust data normalization and workflow optimizations for MetOffice/CSET, enabling more reliable cross-source processing and scalable execution of the data pipelines. Key fix: standardized model_level_number across data sources with a renaming callback and regression test to guarantee consistency in downstream merges. Major tuning: CSET workflow resource and timing adjustments to improve scalability, reliability, and resource utilization. Memory budgets were increased (aggregation memory limit to 100 GB, per-process memory increased by 1 GB, and process family memory adjustments), walls clock extended to PT2H for aggregation, and directives centralized in flow.cylc with aggregation-focused directives. Overall impact: more robust merges across diverse data sources, reduced runtime variability, and a foundation for handling larger datasets in production. Skills demonstrated: data standardization, testing, Cylc workflow orchestration, memory and performance tuning, and cross-source data integration.
February 2025 (MetOffice/CSET) focused on stabilizing and improving data visualization reliability. Key work centered on colorbar rendering fixes and pressure-level color scales to boost interpretability across meteorological datasets. What changed: - Colorbar Rendering and Data Visualization Bug Fixes: consolidated fixes to ensure unique colorbars, removed non-existent test entries, corrected mappings, and ensured consistent scaling across datasets. - Pressure-Level Specific Colorbar Enhancements: added distinct colorbar ranges and mappings for different pressure levels to improve cross-dataset interpretation. Impact: - Reduced visualization errors and inconsistencies, enabling more accurate and faster interpretation of weather data. Improved test hygiene by aligning test data with actual colorbar configurations. Technologies/Skills demonstrated: - Data visualization correctness, color mapping, and per-dataset scaling strategies - Patch hygiene and pull-request discipline (consolidating fixes across multiple commits) - Meteorological data understanding and visualization ergonomics
February 2025 (MetOffice/CSET) focused on stabilizing and improving data visualization reliability. Key work centered on colorbar rendering fixes and pressure-level color scales to boost interpretability across meteorological datasets. What changed: - Colorbar Rendering and Data Visualization Bug Fixes: consolidated fixes to ensure unique colorbars, removed non-existent test entries, corrected mappings, and ensured consistent scaling across datasets. - Pressure-Level Specific Colorbar Enhancements: added distinct colorbar ranges and mappings for different pressure levels to improve cross-dataset interpretation. Impact: - Reduced visualization errors and inconsistencies, enabling more accurate and faster interpretation of weather data. Improved test hygiene by aligning test data with actual colorbar configurations. Technologies/Skills demonstrated: - Data visualization correctness, color mapping, and per-dataset scaling strategies - Patch hygiene and pull-request discipline (consolidating fixes across multiple commits) - Meteorological data understanding and visualization ergonomics
January 2025 monthly summary for MetOffice/CSET: Delivered a robust set of time-based data-collapsing operators and time-aggregation improvements, enhanced test coverage and documentation, and strengthened data-path/configuration workflows. Key features include new collapse_by_hour_of_day operator; collapse_by_lead_time and collapse_by_validity_time operators; separation of time-aggregation logic into dedicated operators (is_time_aggregatable / is_aggregatable_by_time); significant hour-of-day coordinate handling enhancements; and histogram/lead-time analytics workflow upgrades. Maintenance work centered on test scaffolding, test-suite improvements, and documentation updates. These changes improve correctness of time-based rollups, support more accurate lead-time analyses, and establish scalable foundations for future analytics.
January 2025 monthly summary for MetOffice/CSET: Delivered a robust set of time-based data-collapsing operators and time-aggregation improvements, enhanced test coverage and documentation, and strengthened data-path/configuration workflows. Key features include new collapse_by_hour_of_day operator; collapse_by_lead_time and collapse_by_validity_time operators; separation of time-aggregation logic into dedicated operators (is_time_aggregatable / is_aggregatable_by_time); significant hour-of-day coordinate handling enhancements; and histogram/lead-time analytics workflow upgrades. Maintenance work centered on test scaffolding, test-suite improvements, and documentation updates. These changes improve correctness of time-based rollups, support more accurate lead-time analyses, and establish scalable foundations for future analytics.
December 2024 monthly summary for MetOffice/CSET: Delivered critical features for data masking, perturbation processing, and energy-based analytics, reinforced by a robust test suite and comprehensive documentation. Key outcomes include: - Mask Operator enhancements: add generate and apply mask operators, update apply mask, and expand test coverage (including tests for generate_mask and apply_mask), plus cleanup of operator code. - Spatial perturbation operator: added spatial perturbation operator to enable perturbation-aware processing. - Perturbation information as cube attribute: introduced perturbation metadata on cubes to support perturbation-aware workflows. - End-to-end DKE calculation: implemented Dynamic Kinetic Energy calculations with full code integration. - Ensemble functionality and full data support: updated generate_levels_constraint for ensemble workflows and reworked data handling to support full u and v data. - Documentation and examples: major documentation updates (WEB_ADDR docs, cube naming, example recipes) and consolidated documentation tidy-ups, plus new examples. - Quality and maintenance: added tests, fixed failing tests, performed code cleanup, and reviewed changes; removed legacy CubeList functionality to streamline the API. Overall, these efforts improve reliability, scalability, and business value by enabling more accurate perturbation analytics, robust forecasting workflows, and faster on-boarding through better documentation and examples.
December 2024 monthly summary for MetOffice/CSET: Delivered critical features for data masking, perturbation processing, and energy-based analytics, reinforced by a robust test suite and comprehensive documentation. Key outcomes include: - Mask Operator enhancements: add generate and apply mask operators, update apply mask, and expand test coverage (including tests for generate_mask and apply_mask), plus cleanup of operator code. - Spatial perturbation operator: added spatial perturbation operator to enable perturbation-aware processing. - Perturbation information as cube attribute: introduced perturbation metadata on cubes to support perturbation-aware workflows. - End-to-end DKE calculation: implemented Dynamic Kinetic Energy calculations with full code integration. - Ensemble functionality and full data support: updated generate_levels_constraint for ensemble workflows and reworked data handling to support full u and v data. - Documentation and examples: major documentation updates (WEB_ADDR docs, cube naming, example recipes) and consolidated documentation tidy-ups, plus new examples. - Quality and maintenance: added tests, fixed failing tests, performed code cleanup, and reviewed changes; removed legacy CubeList functionality to streamline the API. Overall, these efforts improve reliability, scalability, and business value by enabling more accurate perturbation analytics, robust forecasting workflows, and faster on-boarding through better documentation and examples.
Month: 2024-11 | Repository: MetOffice/CSET Key features delivered: - Enhanced Colorbar and Color Scale Visualization: Consolidated and expanded colorbar definitions and color scales to improve data visualization and UI representation. - LFRic Variable Integration and Data Support: Added LFRic variables support to enable processing and integration of LFRic data. Major bugs fixed: - No explicit major bug fixes reported this month. Focused on feature delivery and data integration improvements to enhance stability and usability. Overall impact and accomplishments: - Improved data visualization fidelity and UI consistency, enabling faster, more accurate data interpretation for users. - Broader data support with LFRic integration, enabling end-to-end processing of LFRic datasets. - Improved maintainability through consolidated colorbar definitions, reducing future technical debt. Technologies/skills demonstrated: - Data visualization design and color scale management - LFRic data processing integration - Version control hygiene and incremental feature delivery
Month: 2024-11 | Repository: MetOffice/CSET Key features delivered: - Enhanced Colorbar and Color Scale Visualization: Consolidated and expanded colorbar definitions and color scales to improve data visualization and UI representation. - LFRic Variable Integration and Data Support: Added LFRic variables support to enable processing and integration of LFRic data. Major bugs fixed: - No explicit major bug fixes reported this month. Focused on feature delivery and data integration improvements to enhance stability and usability. Overall impact and accomplishments: - Improved data visualization fidelity and UI consistency, enabling faster, more accurate data interpretation for users. - Broader data support with LFRic integration, enabling end-to-end processing of LFRic datasets. - Improved maintainability through consolidated colorbar definitions, reducing future technical debt. Technologies/skills demonstrated: - Data visualization design and color scale management - LFRic data processing integration - Version control hygiene and incremental feature delivery
Overview of all repositories you've contributed to across your timeline