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TPEX Products: Introduction

There are three basic goals for implementing The Tabular Product Evolution in XML (TPEX) plan. The first is to modernize and improve upon the current tabular product suite. The second is to streamline and automate the generation of the future products. The third is to maximize the role of the NDFD in the generation of the future product suite.

To meet these objectives, four new XML products have been designed. Two Forecasts in XML (FoX) products, one Observations in XML (ObX), and a Temperature Extremes in XML (TEX) will be generated. These products can be used to generate the legacy SCS text product using eXtensible Stylesheet Language Transformation (XSLT) style sheets. In time, we expect users and partners to migrate away from the legacy text products to the new XML products.

TPEX Products

FoX Products

The two FoX products (FOX3 and FOX7) will be generated hourly from the NDFD CSS, and contain forecasts of weather and high/low temperatures for a select number of cities. The first FoX product (FOX3) will contain forecasts for days 1 through 3. The FOX3 product will provide all the forecast data for the same stations and times as in the current SCS and TAV products. The second FoX product (FOX7) will contain forecasts for days 1 through 7. The FOX7 product provides considerably more information than the legacy three day SCS/TAV products, and could be used as a tool for advanced planning that is not available within the current text product suite (SCS and TAV).

The FoX products have several improvements over their legacy tabular counterparts (SCS/TAV/CCF). First, the FoX products will be issued hourly. This increased frequency of issuance will allow for better forecasts as synoptic weather conditions change throughout the course of a given day. Second, there will be improvements to the CoD parameter. The first improvement will be to add character of the night values. The second improvement is to assign a more precise set of weather definitions to CoD. The point-and-click codes will be used as opposed to the old CCF CoD codes, as they contain both daytime and nighttime values, whereas the CCF codes used in the current legacy product suite only have daytime weather values.

ObX Product

The ObX product will be generated and issued hourly by the NCEP NCO. ObX will contain observed maximum/minimum temperatures and observed precipitation for the same cities as in the legacy SCS text product. At the appropriate times of day, the ObX will also contain high and low temperatures "so far today/tonight" in addition to the high and low temperatures for the most recent complete day/night periods. This is one improvement over the observational information contained in the current tabular product suite. In addition, ObX will be issued hourly, providing more accurate values for maximum and minimum temperature than the current SCS product. For many western cities, overnight low and daytime high temperatures reported in the legacy text SCS are not credible since the issuance times are frequently before the temperature has reached its maximum/minimum value. Hourly issuance of the ObX product and the addition of the high/low so far today weather elements will solve this problem.

The following observing period definitions have been created for the ObX product. For maximum and minimum temperatures, the periods have been defined as 7:00 a.m. to 7:00 p.m. and 7:00 p.m. to 8:00 a.m. Local Standard Time (LST) respectively. Precipitation observations are defined as the last four 6-h synoptic times (cumulative). Maximum Temperature "so far today" is defined as the period between 7:00 a.m. to the current hour (not to exceed 6:59 p.m.). Minimum Temperature "so far tonight" is defined as the period between 7:00 p.m. to the current hour (not to exceed 7:59 a.m. the following day).

TEX Product

The TEX product will be generated and issued four times each day at the standard synoptic times (0000, 0600, 1200, 1800 UTC) by the HPC. It will contain the so-called National High/Low Temperatures observed in the CONUS, using the same criteria currently used in the SCS. Due to the flexibility of XML, the TEX could be readily expanded to include extreme values for Outside CONUS (OCONUS) areas as well (e. g., Alaska high and low).

SCS Product

The NDFD-generated SCS Product is designed to replicate the operational legacy SCS text product produced by the HydroMeteorological Prediction Center (HPC). The SCS product will be issued twice a day at approximately 0100 and 1300 Coordinated Universal Time (UTC). The SCS provides basic observations (Temperatures and Precipitation) for the previous day and 2-day forecasts of temperature and Character of Day (CoD) for 163 cities in the United States, Puerto Rico and the U.S. Virgin Islands. The NDFD-generated SCS will become the operational SCS on January 13, 2009 at 12 UTC.