NCEP MMAB Global Visibility Guidance based on GFS Model Output
Revised October 26, 2006.This guidance is based on the GFS Model output and uses a modified version of the Stoelinga and Warner algorithm used in the eta mesoscale model. The GRIB output files have output in meters from 0 - 20,000 meters. This graphical display on this web site is designed primarily for the use of mariners. Visibilities at or below 1 km (0.5 n mi) are given in yellow; visibilities > than 1 km, but <= 5.6 km (3.0 n mi) are green, and visibilities > 5.6 km, but <= 13.0 km (7.0 n mi) are in blue anything > 13.0 km and le 20.0 km are white. The animations and still figures are in gif format; the animations are on the order of 2 Mb, while the stills are on the order of 15k each. Model output is available throughout the year.
The GRIB files contains 56 records: one for each projection from 03 to 168 hours at 3-h intervals on a 1 deg x 1 deg global grid. gif files are also available. There are links below that will take you to the ftp sites. Please send questions and comments to Robert.Grumbine@noaa.gov
See "About the NCEP Global Visibility Guidance" to find out the differences between the new and old versions of this product.
GFS Visibility Forecast Animations
Table 1. Animation selection table. Each animation has 56 frames with forecasts from 03- through 168-h at 3 hour intervals. The animation has a size of about 2 Mb and takes about 12 minutes to download with a 28.8 K modem.
Individual Visibility Forecasts for Global and Regional Areas
Table 2. Individual forecast selection table. Within each depiction column are the numbers 00, 06, 12, and 18; these are the model run times for the projection hour.
Visibility Forecast Data