What is Emwin?

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 with equipment developed by Zephyrus.

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.

Software settings permit selection of items to be automatically printed as they are received.

Tulsa based Zephyrus Electronics is the pioneer in development of low-cost satellite data broadcast equipment. Design and production of receiving equipment for the WeatherDirect / EMWIN signal is a natural application of that technology. The GOES satellites are received with Zephyrus WX-12 or WX-13 systems. Installation is normally done by the user and typically takes less than one hour to complete.

In some areas, the Emwin signal is recovered from satellite and retransmitted by FM SCA subcarriers, or by way of a stand-alone VHF signal. Using Zephyrus equipment, VHF signals are now being broadcast at 9600 baud. This is done using a similar technique we provided to the National Weather Service to put the 9600 baud signal on the GOES satellites.

Local retransmission operators can replace data that is trivial to their particular location with information gathered from other sources. This is accomplished with a dedicated computer using "retransmission engine" software. Local transmissions at 1200 baud rate must use the retransmission software to parse selected data of local interest from the 9600 baud satellite transmission.