Timing of model runs

Dan Robinson

I'm a little confused about something I feel like I should already know, but I can't find the answer anywhere. What time is the output from a particular model run available? For instance, I'm not seeing the 00Z GFS run available yet on any of the sites I check regularly. 00Z was at 8PM EDT, or almost 5 hours ago. How long does the GFS (and other models) take to run and how soon can you get the output?
The NAM seems to post forecasts 2:15-3:15 hrs after initialization from my experience this year, and the GFS starts posting about 4hrs after initialization. The absolute earliest graphics are usually on the NCEP model site, with RAP/UCAR following shortly thereafter, and CoD showing up after that (with WxCaster closer to the RAP/UCAR timing). Again, this is just from my personal experience.

The WRF-NMM (currently called the NAM-Parallel, which you may have seen in some AFDs) will become operational in mid-June, replacing the NAM-ETA which we've all come know during the past 10 years. At least the NAM-WRF won't have the unfortunate surface dewpoint bug that has plagued the NAM-ETA this year (causing severe overforecasts of surface dewpoints). Speaking of this problem, the EMC is aware of it, and you can read more about it at http://www.emc.ncep.noaa.gov/mmb/research/FAQ-eta.html#nam2

<div class='quotetop'>QUOTE("EMC")</div>
EMC has received much feedback this spring (2006) concerning a high bias in 2-meter dew point temperatures in the operational NAM (Eta) model. This is most likely attributable to a bug in the land-surface physics portion of the NAM that was inadvertently introduced in a May 2005 implementation. This leads to an erroneous excess in surface evaporation over land, particularly during the warm season in non-sparse vegetated regions.[/b]
In my experience, the model files begin transfer shortly after their completion (so transfer might being at 00:30z for the 00Z run). Some of the Local Data Managers (LDM's) and plotting software that is used will wait until most of the model run has completed transfer. This can be a big problem if you're trying to run say the hourly ruc. By the time the file is completely in, you're already 1.5-2hrs into the forecast, not to mention, wait another .5 hr and the next run will be begin coming in. At OU, my group has attempted to write some fancy scripts to do away with waiting. Typically, we can get the first forecast hours out within 2 hrs of the model time.
Let me know if you're interested in this method.

"In my experience, the model files begin transfer shortly after their completion (so transfer might being at 00:30z for the 00Z run)."

Only the RUC is available that quickly - the other models are at the earliest 1:30 after cutoff time. The fastest way of getting data is running LDM/IDD and/or NOAAPORT dish.