At extended range the day-to-day trajectories are affected by substantially larger uncertainty. Therefore, the evolution of the forecast anomalies is represented by the Probability Distribution Function (PDF) based on daily values of individual member projections verifying a given week.
Test products
Please note that these test products are now operational and are here:https://apps.ecmwf.int/webapps/opencharts/products/extended-2dim-pdf
3 Comments
Nicole Girardot
On the verification plots, you could write the number of the day (ie 29, 30, 31, 1, 2, 3, 4 for week from 29/10 to 04/11) instead of dots ?
Nicole.
Laura Ferranti
Thanks Nicole for your nice comments.
About the verification plot the general idea is to check if the 7 analysis values are within the range of the predicted PDF for that given week. Because at the extended range we don't expect the forecast representing the day-to-day evolution , I was avoiding writing the date of the verifying values. I was using the colours (yellow to brown) just to provide an information about the time evolution of the observed anomalies.
Nicole Girardot
Yes I understand that, you are right.
I asked the question because at the beginning, I did not find the information about the signification of the colours of the dots and I supposed it was for the 7 days of the verification period.