GFE Overview Describe the Forecast Process Forecast Process Example

1. Forecast Process for the GFE John BallyBureau of Meteorology Research CentreMelbourne, Australia

2. GFE Overview • Describe the Forecast Process • Forecast Process Example

3. GFE Overview • Collaboration with NOAA • Grid Based • Smart Tools • Automated Text Generation • Digital Forecast Database • Great Potential for Service Improvements

4. GFE Overview

5. GFE Overview -- scalar, vector & weather grids

6. GFE Overview Aim • Support existing and new text services • Data source for new web/graphics services • Mechanism to implement more systematic forecast process • Enable detailed verification > continuous quality improvement

7. GFE : Forecast Process Assumption • Forecasters add value over NWP • Mesoscale effects • Use of observations • Weather description • Warning decisions • Strategy / risk management • Communicating uncertainty

8. GFE : Forecast Process Principles • Coherent and meteorologically reasonable “story” • NOT dynamically consistent “model” • Common approach, consistency, intersite co-ordination

9. GFE : Forecast Process Sources of Guidance • OCF (surface, downscaled consensus forecast) • Short Term Model (surface and some upper) • Long Term Model (surface and some upper) • MSAS (hrly, 5km mesoscale analysis) • Other Inputs • soil dryness, grass curing • thunderstorm forecast guidance • TC tracks, nowcasts TS areas

10. GFE : Forecast Process Assimilation of Guidance • Always have a grid from yesterday • Value in yesterday’s grid • Smooth evolution of forecast • Effort in defining local effects << < < < <  ^ M

11. GFE : Forecast Process Assimilation of Guidance • Evaluate against new models • Change over guidance • Change of guidance << < < < <  ^ ^ ^ ^ ^ ^ ^ M M M M M M M

12. GFE : Forecast Process Anchor Parameters • Represent main features of forecast policy • Wind, T, Td, Sky, PoP1

13. GFE : Forecast Process Other Parameters – public & marine

14. GFE : Forecast Process More Parameters – uppers, fire wx& others

15. GFE : Forecast Process National Liaison • Policy discussion before guidance choice and adjustment • All grids inter-site co-ordination during and after grid editing

16. GFE : Forecast Process Broadscale Adjustment • Time of change • Adjust wind change • Adjust change intensity • Cyclone vortex

17. GFE : Forecast Process Detailed Adjustment (wind) • Blend in analysis • Seabreezes / landbreezes • Topographic effects (wind-effects tool) • Low level jets / diurnal mixing • Serp tool – fine tune for significant locations

18. GFE : Forecast Process Detailed Adjustment (temp) • Blend in analysis • Create / adjust min / max • Temp effects from sea/ land breezes • “Adjust” tool and “wind effects” to fine tune for topo effects • Cloud – precip effects on temp • Strong / light wind effects on min temp • Serp tool – fine tune for significant locations • “FitToMinMax” to adjust h’ly temp

19. GFE : Forecast Process Detailed Adjustment (PoP1) • P(>= 1mm in 1 hr) • Consistency with current (sat/radar/gauge) • Topo effects / rain shadow “wind Effects” tool • Convective > increase PoP with altitude • Consistency with daily PoP grids

20. GFE : Forecast Process Weather grids • showers, thunderstorms • rain, drizzle, snow, sleet • fog, frost • dust, haze, smoke, volcanic ash

21. GFE : Forecast Process Weather grids • Coverage (area covered or likelyhood) • Intensity

22. GFE : Forecast Process Define Precipitating Weather • Area from PoP1 • Intensity from QPF • Type from stability • Phase from thickness or wet bulb freezing level

23. GFE : Forecast Process Consistency checks • Sky / Precip / PoP / Wx • T / Td / Tmax / Tmin / RH • Wind / Gust • Inter – Site - Coordination

24. GFE : Forecast Process Other Steps • Create Hazards • Run Text Formatters • Populate Digital Forecast Database

25. Existing MaxT

26. Change of Guidance Tool

27. 24 hr change of Guidance

28. Add change

29. Query Tool

30. 75 pc Sky

31. Adjust Tool

32. Adjust Max T down 2

33. Time Series of T

34. Fit to Max Min