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Environmental Modeling Center


Department of Commerce NOAA National Weather Service NCEP

Forecaster Considerations

revised April 2, 2004; reviewed July 2, 2013; graphics retired 15 August 2018

This system is designed to give visibilities that may occur under any condition; the old version tended to follow synoptic systems with their precipitation pattern more than showing realistic depictions of lowered visibilities near the surface. The new version is designed to show more realistic depictions of surface visibilities. but it still doesn't show developing advection or arctic sea smoke fog situations very well because of the course resolution of the product. Under extreme conditions these situations may be depicted, but under nominal synoptic conditions, lowered visibilities due to fog and haze may not show up.

The resolution of the system is 1x1 deg lon/lat, and, therefore will miss small patches of fog and haze. The system gives a good sense of the movement of systems on the animations, but these motions and depictions will only be as good as the model output data that is used to produce the visibility predictions. There is a lot of room for improvement of the product and for value adding the product.

The old system had persistant lowered visibilities over Antarctica which are probably not real, and persistant lowered visibilities over the Arctic during the summer were probably over done. Also, areas of convective rainfall were depicted with lowered visibilities that were also over done. The new system resolves most of these problems, but may have other problems which haven't been noticed yet.

We are very much interested in getting feedback from users, so we can improve the product.

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Page last modified: Thursday, 14-Mar-2019 14:36:02 UTC