{
 "about": "The first three lines of the index beside one ECMWF open-data file (the 12 UTC run of 10 November 2026, step 24 h): each line names one field and where its bytes start and how long they are, so one field (about 0.3 to 0.5 MB) can be fetched with an HTTP range request instead of the whole 90 MB file. We keep the index lines, never the GRIB.",
 "by": "incident.meteorology@web-summit.dinis",
 "updated": "2026-11-11T02:29Z",
 "source": "https://data.ecmwf.int/forecasts/20261110/12z/ifs/0p25/oper/20261110120000-24h-oper-fc.index",
 "read_utc": "2026-11-11T02:29Z",
 "licence": "CC BY 4.0 (ECMWF)",
 "attribution": "ECMWF open data, unmodified index lines",
 "label": "fact",
 "lines": [
  {
   "domain": "g",
   "date": "20261110",
   "time": "1200",
   "expver": "0001",
   "class": "od",
   "type": "fc",
   "stream": "oper",
   "step": "24",
   "levtype": "sfc",
   "param": "lcc",
   "_offset": 0,
   "_length": 500611
  },
  {
   "domain": "g",
   "date": "20261110",
   "time": "1200",
   "expver": "0001",
   "class": "od",
   "type": "fc",
   "stream": "oper",
   "step": "24",
   "levelist": "4",
   "levtype": "sol",
   "param": "vsw",
   "_offset": 500611,
   "_length": 285245
  }
 ]
}