Texas Weather Data Online Via OpenGIS Implementation

Gerry Creager
Texas Mesonet
Academy for Advanced Telecommunications and Learning Technology (AATLT)
Texas A&M University
gerry.creager@tamu.edu
Office: 979.458.4020

The National Weather Service (NWS) does not have the mandate or the funds to observe local weather conditions everywhere, or to serve specific applications better handled at the state and local level, by state agencies, or by private consulting meteorologists or industry. Mesonets around the country demonstrate the success of the NWS policy of partnering with local agencies, universities, businesses and individuals in sharing data. (Mesoscale refers to weather systems smaller than those at the continental or oceanic spatial scale, such as migrating cyclones and anticyclones, air masses and fronts, but larger than storm-scale systems, which are generally less than 25 miles across.)

The Texas Mesonet is a regional network of about 300 observing stations (mostly surface stations) designed to observe mesoscale weather features, such as squall lines and large complexes of thunderstorms, and their associated processes. Data are received from over 150 Federal sites (such as the National Weather Service AWOS and FireWeather), over 40 research sites (such as the West Texas Mesonet), and over 150 volunteer weather observation systems, including amateur radio operators and the Citizen Weather Observer Program. The instruments report to a common point for display of the data in near real-time. The data are archived and available to the public and the academic community for research and analysis.

Figure 1: Weather stations

The Texas Mesonet site receives the data automatically from the observing sites using a tool called the Local Data Manager. The data are archived into a PostGIS database. For dissemination over the web, the Texas Mesonet site provides a real-time view of weather using the Minnesota MapServer software with web mapping and data access services that implement the OpenGIS Web Map Service (WMS) and OpenGIS Web Feature Service (WFS) Specifications. Shape files can be created directly from PostGIS. Radar data offerings are currently limited to WMS images, but the Texas Mesonet team hopes to make the actual data available through a server that implements the OpenGIS Web Coverage Service Specification (WCS). Surface observations (Temperature, Dew Point, Barometric Pressure, Winds, Sky Cover, Visibility) are available via WFS. Special projects with the National Weather Service (NWS) have been undertaken to extend the use of the OGC standards, with particular emphasis on the use of open-source tools such as MapServer and the PostGIS database.

Figure 2: Texas weather map with near real-time updates

The citizens of Texas are the direct beneficiaries of the Texas Mesonet's data. The real-time display provides a quick-look capability, while the historical image looping allows the user to get a feeling for the speed of advance of weather as it moves across the state. Making the data available through Web Services also gives GIS users the ability to add a weather dimension to their work. In real-time, emergency management officials can see radar and winds data overlaid on their GIS-based situation and incident maps. For historical work, having the weather data allows better analysis and post-incident critique. In times of severe weather, the site can provide timely information to weather spotters, important members of the NWS team who warn the public of hazards such as wind and hail storms, flash flooding potential, and tornados.