GRIB data is archived in one of the following spatial coordinate systems :
- Spherical Harmonics (SH) - Upper air fields.
- Gaussian Grid (GG) - Surface and some upper air fields.
- Latitude/Longitude (LL) - other centres, wave data.
| Spectral | Gaussian | Lat/lon |
|---|---|---|
| T63 | N48 | 1.875 |
| TL95 | N48 | 1.875 |
| T106 | N80 | 1.125 |
| TL159 | N80 | 1.125 |
| T213 | N160 | 0.5625 |
| TL255 | N128 | 0.7 |
| TL319 | N160 | 0.5625 |
| TL399 | N200 | 0.450 |
| TL511 | N256 | 0.351 |
| TL639 | N320 | 0.28125 |
| TL799 | N400 | 0.225 |
| TL1023 | N512 | 0.176 |
| TL1279 | N640 | 0.141 |
| TL2047 | N1024 | 0.088 |