National Weather Service United States Department of Commerce

Oppressive Heat Continues; Severe Storms and Heavy Rain

An oppressive and dangerous heat wave continues across a large section of the U.S. with hazy, hot and humid conditions. Widespread excessive heat warnings and heat advisories stretch from the central and southern Plains to the Southeast. Severe thunderstorms and heavy rain are expected in multiple spots, in Montana, parts of the Midwest and from the Ohio and Tennessee Valleys into the Carolinas. Read More >

Frequently Asked Questions (FAQ)


1.What is ISCS?


Response: ISCS is a satellite data distribution system operated by the United States National Weather Service (NWS), providing support to (1) the World Area Forecast System (WAFS), and (2) the Region IV Meteorological Telecommunications Network (RMTN).  ISCS support for WAFS is on behalf of the International Civil Aviation organization (ICAO) and World Meteorological Organization (WMO)

ISCS/WAFS purpose is to provide the worldwide aviation community with operational meteorological forecasts and information about meteorological phenomena required for flight planning and safe, economic, and efficient air navigation. The ISCS operates on a 24-hour/365-day basis.  ISCS support for RMTN is part of a cooperative effort between NWS and WMO to improve the Global Telecommunications System (GTS), in WMO Region IV (North and Central America).


2. Why is the ISCS broadcast being terminated at the end of June 2012?


Response: The WAFS portion of ISCS is moving away from satellite broadcast of aviation related data products, and a WAFS Internet File Service (WIFS) has been established as the replacement. WIFS is currently available for access over the Internet to ISCS/WAFS users.


3. Will the Regional Meteorological Telecommunications Network (RMTN) for WMO Region IV (RA-IV) data continue to be a satellite broadcast?


Response: The ISCS satellite broadcast of both WAFS data and RMTN data will be terminated simultaneously for all users of ISCS the end of June 2012. However, alternative methods will be available to WMO RA-IV users within the next 12 months.


4. When the ISCS broadcast is terminated; how will ISCS users receive ISCS data?


Response: ISCS WAFS users can obtain WAFS related data today by accessing the WAFS Internet File Service (WIFS) over the Internet.

ISCS RA-IV RMTN users can obtain RA-IV related GTS and WAFS data by accessing the Global Telecommunications Internet File Service (GIFS) over the Internet. The GEONetcast-Americas (GNC-A) satellite broadcast is a backup for the NWS GIFS.


5. Are there any differences between WIFS data and GIFS data?


Response: The primary difference between WIFS data GIFS data is that WIFS will provide only WAFS data products. GIFS will provide both WAFS and GTS data products in a fashion similar to the current ISCS broadcast.


6. How do WAFS users obtain access to the WIFS File Service?


Response: WAFS users can register by the Internet for access to WIFS at –


7. How do RA-IV users obtain access to the GIFS File Service?


Response: When GIFS is available; users should contact the ISCS Program Office for access authorization.


8. After June 2012; will ISCS users in RA-IV continue to submit ISCS data over the terrestrial NOAAnet (OPSNet) circuits?


Response: The NWS, ISCS Program Office is planning to migrate away from the NOAAnet (now called OPSNet) circuits provided to RA-IV users by June 2012.  Users will be notified of the plan to move away from these circuits by June 2012.  ISCS users in WMO RA-IV can submit their data by using the Email Data Ingest Service (EDIS) currently available at the NWS Telecommunications Gateway (NWSTG). Users that have not already established an EDIS account with the NWSTG should contact the ISCS Program Office for access authorization. Only text data will be accepted via email from the Users. Users may also FTP their data if they are subscribers to the NWSTG FTP Input (Ingest) Service. Information on the NWSTG FTP Input Service can be found on the Internet at


9. Are WIFS and GIFS the only ways to access ISCS data after end of June 2012, and are other alternatives being developed to replace the ISCS broadcast?


Response: All of the ISCS data (WAFS and WMO RA-IV data) is also available on the GTS and via the Internet from the NWSTG FTP File Service ( In addition; the NWS is also investigating the GEONetcast-Americas (GNC-A) satellite broadcast as a backup for the NWS GIFS.  Additional information on GNC-A can be found on the Internet at