J12.3 Introduction to the NCEP Very Short Range Ensemble Forecast System (VSREF) (2010

J12.3

Introduction to the NCEP Very Short Range Ensemble Forecast System (VSREF)

Binbin Zhou, IMSG at EMC/NCEP/NWS/NOAA, Camp Springs, MD; and J. Du and G. DiMego

The NCEP Very Short Range Ensemble Forecast (VSREF) System is

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.