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Department of Commerce NOAA National Weather Service NCEP

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.

Model Cycle (UTC)

Global Animations

Atlantic Animations

Pacific Animations

Southern Hemisphere Animations

0000

select

select

select

select

0600

select

select

select

select

1200

select

select

select

select

1800

select

select

select

select


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.

Projection Hour

Global Depiction

Atlantic Depiction

Pacific Depiction

Southern Hemisphere Depiction

03

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

06

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

09

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

12

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

15

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

18

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

21

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

24

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

30

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

36

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

42

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

48

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

54

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

60

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

66

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

72

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

84

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

96

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

108

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

120

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

132

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

144

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

156

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18

168

00 06 12 18

00 06 12 18

00 06 12 18

00 06 12 18


Visibility Forecast Data



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Page last modified: Friday, 07-Aug-2009 11:33:49 EDT