Reworked the automatic weather delay using some of @andrew’s suggestions. The system is much more simplified now! It has two options found within settings below the primary settings. The two options are enable/disable rain delay and how long of a rain delay when adverse weather is found.
Now that the system is active I will explain exactly how it works. When enabled, the system checks the weather every hour using Yahoo! services. It retrieves a special weather code defined here: http://developer.yahoo.com/weather/#codes. I then compare the current code against a defined list of adverse codes and reset codes. The selected codes are listed below. If an adverse code matches the current code and the system is enabled, a rain delay is automatically set based on the currently configured automatic rain delay setting (default is 24 hours). If a code matches a defined reset code, the rain delay is immediately removed.
If you need any further explanation let me know. Again, this is disabled by default.