We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byAmelia Powell
Modified over 3 years ago
© Crown copyright Met Office WAFC CAT verification Objective verification of GRIB CAT forecasts Dr Philip G Gill, WAFC Science Meeting, Washington, 20 April 2009
© Crown copyright Met Office Contents This presentation covers the following areas Introduction SIGWX forecast comparison Aircraft data Verification methodology Verification results Summary Further improvements
© Crown copyright Met Office Introduction What – Objective verification of gridded binary (GRIB) and significant weather (SIGWX) Clear Air Turbulence (CAT) forecasts Where – Global verification When – November 2008 to January 2009 Why – To demonstrate the quality of the new GRIB forecasts using objective verification. How – Verification against aircraft observations from the Global Aircraft Data Set (GADS)
© Crown copyright Met Office SIGWX and GRIB CAT forecasts SIGWX chart New GRIB forecast
© Crown copyright Met Office Comparison of SIGWX charts UKUSUK&US
© Crown copyright Met Office SIGWX CAT forecast comparison One month UK-US comparison (January 2009) Average coverage of globe UK ~6%, US ~3% Percentage overlap of all forecasts between UK and US ~20% Areas forecast by both UK and US Areas forecast by UK but not USAreas forecast by US but not UK
© Crown copyright Met Office GRIB forecast comparison produced by HKO
© Crown copyright Met Office Global Aircraft Data Set Archive of aircraft data set up by Joel Tenenbaum (State University of New York) British Airways fleet of Boeing 747-400 aircraft Global coverage, but flights mainly over northern hemisphere Automated aircraft observations every 4 seconds Indicator of turbulence derived from vertical acceleration, aircraft mass, altitude and airspeed called the derived equivalent vertical gust (DEVG).
© Crown copyright Met Office GADS Data coverage 10-19 January 2007
© Crown copyright Met Office Verification methodology
© Crown copyright Met Office Forecast assessment Turbulent/non turbulent event defined on 10min aircraft track ~120km - approx grid size Forecast turbulent event – CAT potential >= Threshold Observed turbulent event - DEVG>=2m/s Construct 2x2 contingency tables for each threshold Sum entries in contingency tables over the verification period Produce a Relative Operating Characteristic (ROC) curve by plotting the Hit rate against False alarm rate for each threshold. Turbulence observed No turbulence observed Turbulence forecast HitFalse alarm No turbulence forecast MissCorrect rejection 2x2 contingency table
© Crown copyright Met Office Results UK GRIB and SIGWX ~ 300 000 events
© Crown copyright Met Office Variation with forecast range ~100 000 events
© Crown copyright Met Office Latitudinal variation UK GRIB 50N to 90N ~120 000 events 50S to 20S ~8 000 events 20N to 50N ~130 000 events 20S to 20N ~37 000 events
© Crown copyright Met Office UK and US Nov 2008 and Jan 2009 ROC curve ~200 000 events
© Crown copyright Met Office UK and US latitudinal variation ~60 000 events
© Crown copyright Met Office UK GRIB and SIGWX ~300 000 events SIGWX Automation (SWAM) - UK automated SIGWX chart production system based on GRIB data
© Crown copyright Met Office Summary of results Both UK and US GRIB products show more skill than the manual SIGWX products. Global UK and US GRIB CAT forecasts score similarly Slight difference in scores as forecast range increases Some differences in scores at individual latitude bands – best performance between 20N and 90N. UK CAT coverage on SIGWX charts greater than the US
© Crown copyright Met Office Further improvements Automate verification process Produce statistics by ICAO and WMO regions Improve consistency of forecasts by analysing verification data and altering production systems. Use verification to test future model upgrades and re- tune algorithms
© Crown copyright Met Office Questions and answers
© Crown copyright Met Office WAFC CAT verification Objective verification of GRIB CAT forecasts Dr Philip G Gill, WAFS Workshop on the use and visualisation.
© Crown copyright Met Office WAFC turbulence and Cb hazard verification Recent results and future plans Dr Philip G Gill WAFSOPSG 7/14, 30 th April 2013.
© Crown copyright Met Office Probabilistic turbulence forecasts from ensemble models and verification Philip Gill and Piers Buchanan NCAR Aviation Turbulence.
© Crown copyright Met Office Verification of forecasts of Cbs Bob Lunnon, Aviation Outcomes Manager, Met Office WAFS Science meeting, Washington, April.
Gridded WAFS Icing Verification System Matt Strahan WAFC Washintgon.
GRIB Visualization of data
Verification has been undertaken for the 3 month Summer period (30/05/12 – 06/09/12) using forecasts and observations at all 205 UK civil and defence aerodromes.
Verification of WAFS Global Icing Products Jennifer Mahoney 1 and Sean Madine 1,2 1 NOAA/Earth System Research Laboratory 2 Cooperative Institute for Research.
1) Verification of individual predictors Development of improved turbulence forecasts for aviation Debi Turp © Crown copyright Met Office and the Met Office.
© Crown copyright Met Office Use of GRIB hazard forecasts in flight planning Bob Lunnon, Aviation Outcomes Manager, Met Office WAFS Science meeting, Washington,
Page 1© Crown copyright 2005 Met Office Verification -status Clive Wilson, Presented by Mike Bush at EWGLAM Meeting October 8- 11, 2007.
© Crown copyright Met Office Scientific background and content of new gridded products Bob Lunnon, Aviation Outcomes Manager, Met Office WAFS Workshop.
MeteoExpert workstation.Visualization of new gridded forecasts MeteoExpert workstation. Visualization of new gridded forecasts.
WMS-IV Wechsler Memory Scale - Fourth Edition
WAFS Workshop on the Use and Visualization of Gridded SIGWX Forecasts September 2009.
Robin Hogan Ewan OConnor University of Reading, UK What is the half-life of a cloud forecast?
© Crown copyright Met Office GA Met provision, UK Met Office Jonathan Dutton, Operations Centre, Met Office, UK.
April 24, 2007 Nihat Cubukcu Utilization of Numerical Weather Forecast in Energy Sector.
© Crown copyright Met Office Regional Temperature and Precipitation changes under high- end global warming Michael Sanderson, Deborah Hemming, Richard.
Verification of Probabilistic Forecast J.P. Céron – Direction de la Climatologie S. Mason - IRI.
© 2017 SlidePlayer.com Inc. All rights reserved.