The US National Centers for Environment Prediction (NCEP) produces weather forecasts for the entire world from a model that's updated every 6 hours. The data is made freely available, and with a couple of free tools to convert the data and R you can easily produce am unpdated global weather forecast like this (click to enlarge):
(Check out the heat-wave in Australia!) Physicist and climate scientist Joe Wheatley provides all the details, including R code. All you need is R, the ncdf package to process the data file, and a free command-line tool to convert the file from the format provided by NCEP.
Biospherica: NCEP Global Forecast System