Séminaire lundi 7 nov 14h00 / Seminar Monday Nov 7 14h00


 Conférencier/Lecturer: Syd Peel
                        DRM/MRB, Downsview

        Sujet/Subject:  Adaptation of the ECMWF Extreme Forecast Index
                        to the Canadian Ensemble Prediction System
               par/by:  Syd Peel et/and Laurie Wilson 

          Presentation: Anglais/English

             Lieu/Room: Grande salle du premier étage CMC
                         
                  iweb: http://iweb.cmc.ec.gc.ca/rpn/SEM

          web: http://collaboration.cmc.ec.gc.ca/science/rpn/SEM/index.php

          --------------------------------------------------


                         RESUME / ABSTRACT


The advent of ensemble forecast systems has accorded us the ability to 
objectively quantify the intrinsic uncertainty in the daily weather 
forecast. However, ensemble prediction systems typically generate 
voluminous output. While ensemble forecasts of meteorological fields such 
as mid-tropospheric control lines can be usefully summarised in 
something like a spaghetti plot, surface fields of weather elements such 
as wind or precipitation do not lend themselves to this kind of 
depiction. We therefore explored the feasibility of adapting the Extreme 
Forecast Index (EFI), developed by Francois Lalaurette for the European 
Centre for Medium-Range Weather Forecasts, to the Canadian ensemble 
forecast system.

In this talk we will motivate and define the EFI and discuss some 
adjustments which we introduced in adapting it to the Canadian ensemble 
system, followed by an examination of its performance for several recent 
heavy precipitation events. The salient characteristics of the index will 
be considered and finally we conclude with some possible directions for 
future work.