J12.3
Introduction to the NCEP Very Short Range Ensemble Forecast System (VSREF)
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Presentation PDF (406.8 kB)
specially developed for aviation weather and potential NextGen
applications. Its development was initiated in 2009.
The VSREF system is based on NCEP's operational Rapid Update
Cycle (RUC) and North American Mesoscale (NAM) model runs
using a time-lag technique. The current domain is over the
contiguous US (CONUS). Updated products are generated every
hour with hourly output through 6 hr forecast length. In the
current developing stage, there are ten aviation-weather
related probabilistic products in the VSREF system, including
icing, clear air turbulence (CAT), visibility, fog, ceiling,
low level wind shear, jet stream, surface wind gust, simulated
reflectivity, and freezing height. A convection product will
be added soon and will be based on ESRL/GSD's convection
scheme. There is a web page displaying these products for each
test cycle examples to be shown in the presentation. In this
paper, more detailed information about the NCEP VSREF
including its general structure and algorithms of each product
will be provided.