Recent heat watch-warning systems developed for several cities and regions across the US have taken advantage of web technology to facilitate all aspects of the forecasting of oppressive heat. These systems have been designed using a series of UNIX-run scripts and FORTRAN programs to input forecast data real-time and output the forecast mortality information to a password-protected webpage.

The input of forecast data requires two different concerns– the input of the initial forecast data, and how to handle any updates to the forecast. The initial data have come from either AVN-MOS or the new Point- or Area-Forecast Matrix (PFM or AFM) products, taken directly from Internet sites for processing. Updated forecasts can then be obtained either from manual updates typed into specially designed webpages, or the creation of an updated PFM or AFM. As these products are required to be produced by 2004, ultimately all forecast updates will be handled this way.

The output of the data varies according to whether forecasts are provided for an individual city or an entire region. These forecasts are password-protected so that only weather service office personnel and local authorized agencies may view the output.