TDL Plans for Centralized Statistical Guidance (January 1998)
Attached are two diagrams detailing TDL's plans for development and implementation of the next
generation of MOS guidance. In this context, implementation is defined as provision of the
appropriate products on the AWIPS Satellite Broadcast Network. The first diagram (labeled
Primary) lists activities to be accomplished with currently available resources during the next two
years. The second diagram (labeled Optional) lists additional development to be done as resources
permit. Since TDL is currently involved in writing a new generation of software for developing
and implementing the statistical guidance, implementation of the new MOS guidance is predicated
upon completion of the software system. Termed MOS-2000, this system incorporates modernized
software and better methods of packing the model and observational data. Successful
implementation is also predicated upon efficient staff within TDL. Although TDL has received
requirements for specific weather element guidance from NCEP's Hydrometeorological Prediction
Center and Storm Prediction Center and from OM's efforts to produce probabilistic quantitative
precipitation forecasts, the definitions of most of the elements shown in the diagrams correspond
to past requirements and not to new requirements from OM or OH.
The assumption underlying the primary plan are as follows:
- The initial AVN-based MOS development is designed to provide a package of guidance
comparable to the current NGM MOS guidance. Thus, the initial implementations are
for the 0000 and 1200 UTC runs of the AVN only, and a complete NGM-like package
of AVN MOS guidance will be available by October 1999.
- The AVN-based MOS guidance will satisfy the NWS need for short-range guidance out to day
3 (approximately 72 hours) by including the necessary forecast projections.
- The AVN-based MOS guidance will be available for stations in the CONUS, Alaska, Hawaii, and Puerto Rico.
- The MRF-based MOS guidance will be redeveloped to provide a complete package of guidance
for the 3- to 7-day period. Forecasts will be available for the same set of stations as in the short-range package. Guidance for quantitative precipitation will be added to support ongoing efforts
within OH and OM.
- Development of Eta-based MOS guidance will focus on providing guidance for weather
elements with the greatest impact, namely, thunderstorms, severe thunderstorms, and
- The statistical guidance will be issued in BUFR format for NWS users.
- While a package of AVN MOS guidance issued four times daily is desirable, development of
guidance for the 0600 and 1800 UTC cycles will be deferred until the year 2000 or until
adequate resources become available.
The optional plan essentially provides additional AVN MOS guidance for the 0000 and 1200
UTC cycles, speeds up development of the AVN MOS guidance for the 0600 and 1800 UTC
cycles, and adds weather elements to the Eta MOS package.
Issues that need to be addressed:
- A list must be established to indicate the stations for which the guidance is to be developed.
TDL estimates that guidance could be provided for approximately 1000 sites.
- Requirements specifying the weather elements and the temporal resolution
of the guidance must be provided.
- The current NGM MOS guidance package is available on the Cray at approximately 0400 and 1600
UTC. The proposed AVN MOS guidance package will be available approximately 1 hour later,
based on current run times.
- The assumption that the AVN MOS guidance wili be issued only in BUFR form implies that
non-AWIPS NWS sites may not be able to access the guidance.
- The likelihood of inadequate human resources is high.
- The impact of Y2K issues and the need to move the implementation software to a new
computing platform by the end of 1999 both adversely affect TDL resources.
Reproduced from Western Region Technical Attachment.