DESCRIPTIONS - This satellite broadcast is carried using the first three virtual channels (PVC 1, 2 and 3) for ICAO aviation meteorologists to meet their operational flight planning needs.

Data to be Broadcast: The U.S., through FAA, support to the NWS is operating the ICAO dissemination of three data types using an ISCS satellite broadcast service for the WAFS:

1. Gridded Binary (WMO GRIB) coded data sets
   
   
2. Alphanumeric data messages (primarily OPMET), and
   
   
3. Graphical T4 coded data (significant weather, wind and temperature and volcanic ash charts).
   
   

WMO GRIB Flight Planning data includes flight planning u and v wind components and temperature field forecasts in support of aircraft operations. Additional meteorological fields are included such as geopotential heights, humidity, vertical velocity and precipitation for Regional Area Forecast Center use in preparing guidance materials such as significant weather chart preparation and general forecast operations.

Resolution:

• Temporal - 12, 18, 24, and 30-hour forecasts from the 0000-UTC and 1200-UTC data bases
• Horizontal - thinned 1.25 x 1.25 degrees (lat/long) at the equator (about 140 kilometers globally)
• Vertical - ICAO required flight levels including maximum wind and tropopause

    Flight level (FL)   Pressure (hPa)

50 850 100 700 180 500 240 400 300 300 340 250 390 200 450 150 TROPOPAUSE (height, wind direction, speed, and height of maximum wind) 530 100 600 70

The GRIB geographical coverage is defined in the range I-P for the 8 octants

1. I=0-90N 30W-60E,
2. J=0-90N 60E-150E,
3. K=0-90N 150E-120W,
4. L=0-90N 120W-30W,
5. M=0-90S 30W-60E,
6. N=0-90S 60E-150E,
7. O=0-90S 150E-120W,
8. P=0-90S 120W-30W

Aeronautical/Operational Meteorological (OPMET) data includes the following data for flight planning.

• METAR, SPECI, TAF and TAF AMD - as available from over 1200 locations listed in the ICAO Regional Air Navigation Plan publications specified as regular and alternate service and general aviation use airports.
• Significant Meteorological (SIGMET) reports.
• Abbreviated plain language route (ROFOR) and area forecasts.
• Aircraft reports (AIREP).
• International NOTAMS [future planned].
• Administrative messages concerning WAFS data and system.

Charts and Graphics data includes the information to satisfy the requirement for generally long-haul international flight documentation. For domestic or short-haul and lower level flights, PCGRIDDS software is envisioned to provide wind and temperature charts and other information.

Specifically, the following are provided:

• Significant Weather Charts - prepared by the U.S. and other ICAO designated Regional Area Forecast Centers.
• Volcanic Ash forecast charts(s) - produced automatically, shortly after WAFC/RAFC Washington is notified of a volcanic eruption.
• Wind and Temperature Charts - global coverage for 5 flight levels (FL-180, FL-240, FL-300, FL-340 and FL-390) for 18-and 24-hour valid times.