NWS PHI -

The Graphical Forecast Editor (GFE) presents gridded forecast fields to meteorologists for editing, and they can select the weather elements, sources, and grids to view, and use a variety of tools to edit the data. The capabilities of the GFE include views of the data with three editors – grid inventory, spatial, and temporal, as well as spatial interpolation and basic and advanced editing tools (Figure 1).

In providing an inventory view of weather elements, the Grid Manager shows the valid time of each grid for each weather element. Using the editing capabilities in the Grid Manager, meteorologists can copy derived model data into the forecast, adjust the valid time of grids, and interpolate data from one grid to another.

The Spatial Editor displays one or more grids with underlying map backgrounds. Meteorologists can control the appearance of the display by varying the color enhancement curves, set of displayed weather elements, and contour intervals. In addition, zoom/pan, overlay, and animation capabilities are provided.

The Temporal Editor provides a view of weather elements in a time-series representation that allows forecasters to quickly view and edit how a weather element changes over time. It also shows the value of multiple weather elements over a point or geographical area depicted on the Spatial Editor (shown in Figure 1).

Figure 1. Grid Manager, Spatial Editor, and Temporal Editor

Figure 1. The GFE includes views of data using three editors: Grid Manager (an inventory of weather elements), Spatial Editor (grids in plan view), and Temporal Editor (a time-series representation of weather elements).

Before a forecast can be completed, it must be defined for all times in the forecast period. The Spatial Interpolation capabilities of the GFE allow the forecaster to "fill-in" and interpolate data from one grid to another. For example, if the forecaster defines a wind grid at 1200 UTC and another at 2000 UTC, the system can provide hourly interpolation for all periods between 1200 and 2000 UTC.

Basic and Advanced Tools – Forecasts are edited through a series of basic and advanced editing tools that allow users to define an area on the Spatial Editor and then apply an editing action to that area. Basic tools are used to assign specific values to that area, slightly adjust existing values up or down, and smooth out gradients. The defined areas on the Spatial Editor need not be drawn by hand, but can be calculated based on other grids. For instance, forecasters may direct the system to select an area where temperatures are below freezing, and if the precipitation type is shown as rain, they can change it to snow.

Advanced tools known as "Smart Tools" add meteorological concepts into the system and have full access to all model and terrain data. Forecasters can enhance the Quantitative Precipitation Forecast (QPF) based on vertical motion. The Smart Tools can be used to calculate the vertical motion from the high-resolution terrain and surface winds, and then apply a correction factor to the QPF. Meteorologists can use these tools to compare a particular forecast field to others and define their relationship. "Smart Scripts" can be used to chain the Smart Tools together for more efficient use.

As mentioned before, configurability is the most important function of Smart Tools. It is impossible to write a fixed set of tools that will work for everyone everywhere. Instead, we have written a basic set of tools and provided a framework in which forecasters can write their own version of Smart Tools in a powerful language called Python. (See a later article on the development of Smart Tools.)

A contour-editing tool is also provided to make small corrections to existing grids by redrawing portions of contours, or to generate a completely new grid from scratch by drawing a series of contours.

Another very needed feature of the GFESuite technology is automatic product generation, the last of the three steps of the IFPS process. To reiterate, the first step in forecast preparation is initialization of the digital database, usually with objective forecasts derived from at least one numerical model. Since the forecast is defined in far greater detail than was possible in the traditional system, comprehensive monitoring and verification systems now alert forecasters of any meteorological inconsistencies, or if the forecast deviates from the observations. In the second step, forecasters interactively modify weather elements from which many products can be automatically composed and formatted. Once the set of gridded forecast elements is defined, products can be generated with little or no forecaster intervention.

The IFPS/GFESuite product suite is tiered in order to accommodate various user levels: high-end users, "modern" users, and low-end users (Figure 2). High-end users could receive gridded products (such as raw forecast numbers) that would be used to generate additional products or serve as input to numerical models. Modern users could access the Web to display imagery and graphics that represent the forecast. Some of these products could be interactive: a click on a map would bring up a forecast tailored to that exact location. Low-end users could only access the digital forecast in the form of simplified text products.

The flexible and tailorable product generation capabilities of the GFESuite provide three types of output products: grids, graphics, and text (Figure 2).

Figure 2. IFPS tiered product suite

Figure 2. IFPS tiered product suite to accommodate different levels of users.

The very detailed gridded datasets can be best viewed in graphical form, which can accurately represent the detail. Graphical products can be customized to provide imagery, contour analysis, time series, domains, and a combination of some or all of these attributes. The graphical output from GFESuite is available as Portable Network Graphics (PNG) imagery, which is compatible with all popular Web browsers. The text capability provides full access to the forecast grids using data sampling techniques. Formatted table-type products that depict weather elements, areas, and times can be constructed with minimal effort. Free-flowing text products can also be generated, and a text language translator will translate the forecasts from English to French and Spanish. Interactive products, available through a Web interface, allow users to query the grids for specific information; for example, users can click on a specific location for a customized worded or graphical forecast.