1 / 16

J. Paul Dallavalle and Valery J. Dagostaro Meteorological Development Laboratory

Objective Interpretation of Numerical Weather Prediction Model Output – A Perspective Based on Verification of Temperature and Precipitation Guidance. J. Paul Dallavalle and Valery J. Dagostaro Meteorological Development Laboratory National Weather Service/NOAA

alicemyers
Download Presentation

J. Paul Dallavalle and Valery J. Dagostaro Meteorological Development Laboratory

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Objective Interpretation of Numerical Weather Prediction Model Output – A Perspective Based on Verification of Temperature and Precipitation Guidance J. Paul Dallavalle and Valery J. Dagostaro Meteorological Development Laboratory National Weather Service/NOAA Symposium on the 50th Anniversary of Operational Numerical Weather Prediction June 14-17, 2004 University of Maryland College Park, MD

  2. Outline • History of NWS verification program • Methodology • Results • Conclusions

  3. History of NWS Verification Program • April 1966 – begins • Initially compared NMC subjective guidance and NWS local forecasts for max/min temperature and PoP • April 1970 –perfect prog max/min guidance replaces NMC guidance • January 1972 – MOS PoP guidance replaces NMC guidance • August 1973 – MOS max/min guidance replaces perfect prog guidance

  4. Max/Min Temperature Probability of Precipitation Local forecast is for daytime max/nighttime min Local forecast is for 1200-0000 UTC (day) and 0000-1200 UTC (night) Forecast Elements

  5. 0000 UTC cycle (* Added in October 1975 for temperature; in Summer 2002 for PoP) 1200 UTC cycle Today Tonight Tomorrow Tomorrow Night * Tonight Tomorrow Tomorrow Night Day after Tomorrow * Forecast Projections

  6. Methodology • 80 CONUS sites • Verification statistics for warm (Apr. - Sept.) and cool (Oct. – Mar.) seasons • “Official” verification observation • “Official” guidance • Fixed climate standard (1961- 90 normals for max/min; 1972- 85 relative frequencies for PoP)

  7. Verification Sites

  8. Verification Measures • Max/Min Temperature • Mean Absolute Error • PoP • Improvement in Brier Score relative to climate

  9. Significant Changes to “Official” Guidance • January 1972 -- PE-based MOS PoP • August 1973 -- PE-based MOS max/min • April 1980 -- LFM-based MOS • November 1985 -- daytime max/nighttime min • June 1993 -- NGM-based MOS • Summer 2002 -- GFS-based MOS

  10. Max Temperature – Cool Season (0000 UTC Cycle)

  11. Max Temperature – Warm Season (0000 UTC Cycle)

  12. Min Temperature – Cool Season (1200 UTC Cycle)

  13. Min Temperature – Warm Season (1200 UTC Cycle)

  14. PoP – Cool Season(0000/1200 UTC Cycles Combined)

  15. PoP – Warm Season(0000/1200 UTC Cycles Combined)

  16. Conclusions • Public weather forecasts and guidance have improved during the period • Quality of day 2 local forecasts now is equal to that of the day 1 forecasts ~ 20 years ago • Quality of day 2 guidance now is equal to that of the day 1 guidance ~ 10 years ago • Skill of PoPs is higher in cool season; errors in max/min are greater in cool season, but so is rate of improvement • High correlation between quality of guidance and local forecasts

More Related