A training workshop, particularly aimed at forecasters, will be held on the verification of ensemble forecasts. The workshop is organized by the EMS in collaboration with the Joint WWRP/WGNE Working Group on Verification.


Date & location:
Sunday, 8 September 2013, Reading University, Palmer Building. The workshop will start at 9:30 am and finish around 16:30.


The workshop will focus on the interpretation of verification results for the assessment of ensemble and probability forecasts. Specific topics to be discussed are listed below. Short exercises will be included for each of the main topics, and are designed to stimulate discussion and understanding of the interpretation of the various verification measures. Participants are invited to send examples of verification results for which they have questions about the interpretation. These may be discussed during the workshop.


Topics and schedule

1. Probability and distributions – concept review with application to probability estimation from ensembles (45 min)
-distributions and sampling; types of distributions; pdf and cdf
-estimating probabilities from ensembles

2. Verification of probability forecasts I: Reliability, resolution and sharpness (1.5 h)
-Brier score, factorization
-Brier skill score; sensitivity to underlying climatology
-reliability diagrams as representation of reliability and resolution; sharpness histogram
- Exercise

3. Verification of probability forecasts II: Discrimination and the ROC (1.5 h)
-illustration of concept of discrimination
-Exercise
-ROC: description of computation method
-Interpretation and relationship to other scores (Pierce and 2AFC)
-Sensitivity to underlying climatology
- Exercise

4. Verification of the ensemble-derived distribution (45 min)
-RPS and CRPS, and skill scores
-Rank Histogram
-Local distribution verification: Ignorance score
- Exercise

5. New methods in ensemble verification (30 min)
-ensemble applications of spatial methods; multivariate rank histogram (MST);

6. General discussion and wrap up (30 min)


Teachers
• Wilson, Laurence
• Mittermaier, Marion

Target audience
This workshop is aimed particularly at operational forecasters, who want to extend their understanding of the use of ensemble forecasts, particularly for the prediction of high impact weather. Thus the applicants for the workshop should have substantial experience in operational forecasting and a basic knowledge of statistical concepts.


Registration for the workshop is now open. Please see "Registration" or go directly to http://www.ems2013.net/registration.html

Deadline for registration: 10 July 2013.
Maximum participant number: 30
Minimum participant number: 10
Be aware that the workshop may be cancelled due to too small number of registrations.