\journalname
JGR-Atmospheres
Trends in the predictive performance of raw ensemble weather forecasts
Abstract
\journalname
JGR-Atmospheres
This study applies statistical post-processing to ensemble
forecasts of near-surface temperature, 24-hour
\deleted[date/time, etc.]precipitation,
\addedall totals,
and near-surface wind speed from the global model of the European
Centre for Medium-Range Weather Forecasts (ECMWF). The main objective
is to evaluate the evolution of the difference in skill between the
raw ensemble and the post-processed forecasts. Reliability and
sharpness, and
\replacedhencetherefore skill,
of the former is expected to improve over
time. Thus, the gain by post-processing is expected to decrease. Based
on ECMWF forecasts from January 2002 to March 2014 and corresponding
observations from globally distributed stations we generate
post-processed forecasts by ensemble model output statistics
\addedabbreviated as (EMOS)
for each station and variable. Given the higher average skill of the
post-processed forecasts, we analyse the evolution of the difference
in skill between raw ensemble and EMOS. This skill gap remains almost
constant over time indicating that post-processing will keep adding
skill in the foreseeable future.