Topic: GFS models and accuracy

[australiasevereweather]

Hi,

I thought given the ominous weather we are having at the moment, we could discuss the GFS models and its accuracy thus far.

I must say that in the last year and a half, the GFS has been playing silly games. Most of the problem seem to be the over forecasting of moisture to near unrealistic levels both here and in the Tornado Alley. Today was another situation once again where surface lifted index was way over forecast based on predicted temperatures. Meso LAPS and other Australian models have a better handle on these situations.

What are your thoughts? Let us know of certain situations you may have experienced where variables on the day were over-forecast or under-forecast.

Regards,

Jimmy Deguara

[Meso]

An interesting post, Jimmy.

Model changes are listed at:
http://www.emc.ncep.noaa.gov/gmb/STATS/html/model_changes.html

If it was 18 months ago, it could be this change:
 05/31/05 12Z:(See TPB - includes changes made 06/14/05 and 07/07/05)

    * Resolution change:
        old: T254L64 to 84h, T170L42 to 180h, T126L28 to 384h
        new: T382L64 to 180h, T190L64 to 384h
    * Increase mountain blocking, decrease vertical diffusion and modify sea ice.

Specifically: http://www.emc.ncep.noaa.gov/gc_wmb/Documentation/TPBoct05/T382.TPB.FINAL.htm
See points 2 and 3 under 'model changes'.

[Meso]

Also, to add to this thread (since it's related to GFS), does anyone generate their own plots using the NCEP/NOAA servers? I've noticed some severe dataflow problems lately, even though their planned server move was weeks ago.

[Meso]

According to user lists for the popular 'nomad' servers within NCEP, the data flow was turned off when the systems were moved to new machines recently, and the NCEP director advised that the data flow will NOT be turned back on. 

As of this morning (AEDT), I've been advised that there will be a meeting with NCEP operations on the data flow tomorrow (nomad3/nomad5/nomad6), and some or all data flow may be allowed at that time. Until then, data will be missing, or copied manually by Jordan and his crew.

Fingers crossed, guys!  If data flow for these servers dies, I'll pen a letter to the director.