EMWIN is National Weather Service information that is constantly updated on a 24 hour basis.
The service is public information and is free.
The signal originates at the Weather Service Headquarters in Silver Spring, Maryland. It is uplinked to GOES satellites from the transmission site in Wallops Island, Virginia. The signal is encoded and modulated for satellite broadcast.
The Weather Service designation for the data is
"EMWIN", which stands for
"Emergency Managers Weather Information
Network
". The information is distributed as a signal that allows your personal
computer to become a graphics, data, and alarm
terminal.
With appropriate
"Windows" software, the information is displayed in both
text and graphical form. It includes: 
- Local, area, and regional forecasts
- Hourly conditions of NWS reporting stations
- Weather maps
- National radar summaries
- Weather satellite photographs
- Severe weather warnings anywhere in the coverage area take
priority over all other transmissions. The software provides visible and audible alarms when warnings are
transmitted.
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