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THERMAL SOARING FORECASTING SkewT Plots, Boundary Layers BLIPMAPS, Models and Methods

RICHARD KELLERMAN SATURDAY , FEBRUARY 21, 2004. THERMAL SOARING FORECASTING SkewT Plots, Boundary Layers BLIPMAPS, Models and Methods. YOU DON’T NEED TO BE A WEATHERMAN 1. YOU DON’T NEED TO BE A WEATHERMAN 2. CONTENT. WHY BOTHER? WHAT I CAN DO WHAT I CAN’T DO. CONTENT (CONT’D). SKEWT’S

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THERMAL SOARING FORECASTING SkewT Plots, Boundary Layers BLIPMAPS, Models and Methods

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  1. RICHARD KELLERMAN SATURDAY , FEBRUARY 21, 2004 THERMAL SOARING FORECASTINGSkewT Plots, Boundary Layers BLIPMAPS, Models and Methods

  2. YOU DON’T NEED TO BE A WEATHERMAN 1

  3. YOU DON’T NEED TO BE A WEATHERMAN 2

  4. CONTENT • WHY BOTHER? • WHAT I CAN DO • WHAT I CAN’T DO

  5. CONTENT (CONT’D) • SKEWT’S • BASIC BL PHYSICS • BLIPMAPS AND THE RUC20 MODEL • MAKING THE FORECAST • EXAMPLES • GETTING THE DATA

  6. WHY BOTHER? • BLIPMAPS DO IT ALL • SOMETIMES • BLIPMAPS EXEMPLIFY THE POWER OF COMPUTER GRAPHICS • BLIPMAPS EXEMPLIFY THE LIMITATIONS ALSO • WHAT’S UNDER THE HOOD? • NOT DEPENDENT ON A SINGLE SOURCE

  7. WHAT I CAN DO(WITHOUT BLIPMAPS) • ANSWER THE FOLLOWING QUESTIONS: • WHEN LIFT WILL START AND END? • HOW HIGH? • HOW STRONG? • WILL THERE BE CU? • WILL THERE BE SPREADOUT? • WILL THERE BE CONVECTIVE O.D?

  8. WHAT I CAN’T DO(WITH OR WITHOUT BLIPMAPS) • HANDLE CIRRUS WELL • LOOK GOOD IN THE VICINITY OF FRONTS • ACCOUNT FOR MICRO-SCALE EVENTS • DEAL WITH WAVE SUPPRESSION • PREDICT STREETING • BE PRECISE ABOUT LIFT STRENGTH • QUANTIFY TERRAIN EFFECTS

  9. WHAT ONLY BLIPMAPS CAN DO • PROVIDE USEFUL INFORMATION OVER A LARGE AREA • DEPICT BETTER AND WORSE CONDITIONS • PROVIDE DETERMINISTIC LIFT STRENGTH PREDICTIONS • DITTO FOR THE BUOYANCY/SHEAR RATIO

  10. WHAT’S THIS?

  11. SKEWT’S • COMPACT DATA DISPLAY (GRAPHS) • BALLOON SOUNDINGS • MODEL SOUNDINGS • CALCULATORS • IDEAL FOR THERMAL SOARING FORECASTS • RECAP

  12. TEMPERATURE AND PRESSURE AXES

  13. ADD DRY ADIABATS

  14. “8 GM/KG” ADD CONSTANT MIXING RATIO LINES DETAILS (SLIDE 1)

  15. MAKING CLOUDS

  16. TEMPERATURE AND DEWPOINT LAPSE RATES • TEMPERATURE LAPSE RATE ~5.3 F o/1,000 FT. • DEWPOINT LAPSE RATE ~0.9 F o/1,000 FT • CLOUDBASE = ((T – DP) / 4.4) * 1,000 FT

  17. LAPSE RATES AND ADIABATS • TEMPERATURE LAPSE RATE • DEWPOINT LAPSE RATE • DRY ADIABATIC LAPSE RATE • SATURATED ADIABATIC LAPSE RATE • T AND DP LAPSE RATES ARE DATA • DALR’S AND SALR’S ARE CALCULATED • THEY ARE RESPECTIVELY ~3C/1,000 FT AND ~2C/1,000 FT • THE “SURFACE ADIABAT” IS THE (DRY) ADIABAT PASSING THROUGH THE SURFACE TEMPERATURE • IN THE CONVECTIVELY MIXED BL: T LAPSE RATE = DALR

  18. TEMPERATURE AND DP ALOFT

  19. GOOD DAY WITH CU FORECASTS PM SOUNDING METHOD

  20. GOOD DAY – NO CU SOARING FORECASTS PM SOUNDING METHOD

  21. BAD DAY (MIFFLIN, 2001 5/19)

  22. SOARING FORECASTS“THERMAL INDEX/AM SOUNDING METHOD”(SLIDE 1) • GET AM SOUNDING • GET FORECAST SURFACE TEMPS • CONSTRUCT SURFACE ADIABAT FOR TRIGGER • CONSTRUCT OTHER SURFACE ADIABATS AS DESIRED

  23. SOARING FORECASTS“THERMAL INDEX/AM SOUNDING METHOD”(SLIDE 2) TEMPERATURE EVOLUTION

  24. A DAY IN THE LIFE OF THE CONVECTIVE BL • THE FOLLOWING SEQUENCE SHOWS WHAT ACTUALLY HAPPENED ON SEPTEMBER 10 2003 AT ABE • IT ALSO MAKES VERY CLEAR ONE OF TWO FUNDAMENTAL PROBLEMS WITH THE AM SOUNDING/TI METHOD

  25. 8:00 AM

  26. 11:00 AM

  27. 2:00 PM

  28. 5:00 PM

  29. TEMPERATURE EVOLUTION SOARING FORECASTS, “TI” METHOD (SLIDE 2)

  30. DEWPOINT EVOLUTION

  31. WHEN GOOD CLOUDS GO BAD, SLIDE 1

  32. WHEN GOOD CLOUDS GO BAD, SLIDE 2

  33. NUMERICAL MODELS • RUC20/MAPS • BLIPMAPS • RUC VERSIONS

  34. SOME OF WHAT THE RUC20 MODELS • TERRAIN • SOIL MOISTURE • LAND USE INCLUDING VEGETATION COVER • CLOUD PHYSICS • RADIATIONAL FLUXES • CONVECTION • ADVECTION • 3D PRESSURE

  35. RUC20 VEGETATION CANOPY AND SOIL PHYSICS NOAA Forecast Systems Laboratory, RUC Development Group

  36. RUC20 DATA INPUTS NOAA Forecast Systems Laboratory, RUC Development Group

  37. SOME RUC20 ASSUMPTIONS • 20 KM GRID • 50 LAYER ATMOSPHERE

  38. RUC20 TERRAIN RESOLUTION NOAA Forecast Systems Laboratory, RUC Development Group

  39. RUC20 2M TEMPERATURE PERFORMANCE NOAA Forecast Systems Laboratory, RUC Development Group

  40. RUC20 WIND FORECAST ERRORS NOAA Forecast Systems Laboratory, RUC Development Group

  41. RUC20 RAOB VERIFICATION NOAA Forecast Systems Laboratory, RUC Development Group

  42. RUC20 SCHEDULE

  43. SOARING FORECASTS PM SOUNDING METHOD • GET THE RUC20 PM SOUNDINGS • CONSTRUCT THE SURFACE ADIABAT PASSING THROUGH THE (2M) SURFACE VIRTUAL TEMPERATURE • DETERMINE HEIGHT OF LIFT • ESTIMATE STRENGTH OF LIFT • DETERMINE CLOUDBASE • ASSESS THE CHANCE OF LATERAL OR VERTICAL OD • ASSESS THE SENSITIVITY OF THE FORECAST TO DP AND/OR T ERRORS GOOD DAY – NO CU GOOD DAY WITH CU

  44. MIFFLIN 2001 P2: FORECAST

  45. MIFFLIN 2001 P2: WHAT HAPPENED (SLIDE 1) • STRONG LIFT WITH CU AT 7,000 FT • QV’S AND X’S DAY

  46. MIFFLIN 2001 P2: WHAT HAPPENED (SLIDE 2) • EVERYONE ELSE’S DAY • HEAVY RAIN SHOWERS • BROTHER UNABLE TO LAND • 60 MPH GUST AT THE FIELD • SPREADOUT • DISGRUNTLED PILOTS

  47. BLIPMAPS • SUPPLEMENTS • COMPLEMENTS • PAINTS THE SOUNDING GRID DATA • THERMAL STRENGTH IS DETERMINISTIC (NOT EMPIRICAL)

  48. PREPARING THE FORECAST (SLIDE 1) • SURFACE ANALYSIS • FORECAST DISCUSSIONS • SATELLITE IMAGERY • SURFACE OBSERVATION

  49. PREPARING THE FORECAST (SLIDE 2) • SKEWT PLOTS • BLIPMAP

  50. DETAILS (SLIDE 1) • VIRTUAL TEMPERATURE • TV = T + W/6 • VISIBILITY • WIND SHEAR • CIRRUS ADD CONSTANT MIXING RATIO LINES

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