[Stoch] You are invited to download NCEP/GEFS reforecast data

[Tom Hamill]

Hi all,

We are opening up our servers to make available the recently computed 
2nd-generation NCEP Global Ensemble Forecast System (GEFS) reforecast 
data.  For the currently operational version of the GEFS (implemented 
Feb 2012), we now have, for every 00Z initial condition from 1985 to 
2010, 11-member, 16-day ensemble forecast data available.

Details are available at 
http://esrl.noaa.gov/psd/forecasts/reforecast2/README.GEFS_Reforecast2.pdf.

The web page is at http://esrl.noaa.gov/psd/forecasts/reforecast2/.

We will fill in 2011 and 2012 data in the coming months.  A BAMS article 
is in preparation providing a more complete description of the data set 
and potential applications.

We hope and expect that this data set will facilitate both the 
development of improved forecast products and facilitate many 
interesting research projects.  Anticipated applications include:

(1) *Statistical post-processing*.  With 25+ years of reforecasts, even 
with rare events such as heavy precipitation or tropical cyclones, we 
hope to have provided enough samples to allow a useful calibration of 
the forecasts.  The relative merits of addressing model error via 
statistical post-processing vs. via stochastic parameterization and/or 
multi-model approaches may be of interest to this community.

(2) *Understanding the forecastability of common and uncommon 
phenomena*.  Say you are interested in a particular phenomena that 
doesn't happen very often, perhaps major lake effect snowstorms in 
Buffalo.  How well does the model do in forecasting such phenomena?  A 
multi-decadal data set will provide a sufficiently large sample size to 
explore such a question and be able to provide statistically meaningful 
results.

(3) *Initialization of regional reforecasts*.  Perhaps there is an old 
case that you would like to run with WRF at 3-km grid spacing.  You need 
lateral boundary conditions and initial conditions.  The full reforecast 
data set archive on our DOE site (again, see README file) can provide this.

We don't have a large staff dedicated to making this all work.  We don't 
know what will happen should a dozen people try to download a lot of 
data at the same time.  Let us know if you have any problems.  We 
promise to do our best to sort through any issues.

Our online data set is massive, nearing 150 TB in size (the full model 
data set, about 1 PB, is also archived on tape at DOE). Should you be 
interested, say, in accessing precipitation forecasts over a particular 
country, every member, every day, every year, this will involve reading 
and subsetting data from hundreds of thousands of files.  Expect a 
turnaround time for such requests of a day or two.  For smaller amounts, 
the turnaround time will be commensurately faster.  Also, please note 
that we have designed the web-based interface to limit how much data you 
can download in one slug.

Thanks in advance should you choose to try using this data set.  We hope 
this data set is of use to you and your organizations.

Tom Hamill, Jeff Whitaker, Gary Bates, and Don Murray
(with ample assistance from Tom Galarneau, Mike Fiorino, and many others)
NOAA Earth System Research Lab
Boulder, Colorado, USA
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/stoch/attachments/20120826/d3e9f75b/attachment.html