This page allows for download of raw data found within products like this: FD1US1. They contain near term forecasts of temperatures and wind speed aloft. More details on the product can be found with the NWS Directive 10-812.
Backend documentation exists for those wishing to script against this service. The archive dates back to 23 September 2004.
Related: CWSU Center Weather Advisories Graphical AIRMETs PIREPs SIGMETs