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Re: [conduit] [ldm-users] GFS change at 1200 UTC 25 September?

You can see the noisiness in the attached gif; just a 500 hPa height field. For comparison, a similar plot from last year shows how things looked with the old postprocessor.
I suspect the change in the post processor, with the stated intention of making the NAM and GFS post processing schemes uniform, has eliminated a smoothing process that has heretofore existed with the 0.5 GFS model output. The "new" look of this field recalls the "noisiness" that we have typically seen with the hi-res NAM output.
Any way to see if the pre-9/25 1200 UTC fields had smoothing built-in to the postprocessor? 
______________________________________________________________________
Kevin Tyle, Systems Administrator               **********************
Dept. of Earth & Atmospheric Sciences           ktyle@xxxxxxxxxxxxxxxx
University at Albany, ES-235                    518-442-4578 (voice)
1400 Washington Avenue                          518-442-5825 (fax)
Albany, NY 12222                                **********************
______________________________________________________________________

On Fri, 28 Sep 2007, David Knight wrote:


But that notice

http://www.nws.noaa.gov/om/notification/tin07-59gfs_upgrade_unifiedpost.txt

says:

"THE PRIMARY IMPACT TO CUSTOMERS RECEIVING THE GFS WILL BE THAT
THE DEFAULT PRECIPITATION TYPE ALGORITHM WILL CHANGE"

and further

"THE PRODUCTS/GRIDS WHICH ARE DISSEMINATED TO NOAAPORT AND/OR THE
SATELLITE BROADCAST NETWORK /SBN/ WILL NOT BE CHANGED IN VOLUME
OR CONTENT."

So there appears to be more to this than that . . .

David

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