{
 "generated_utc": "2026-07-26T22:15:59Z",
 "gfs_cycle_utc": "2026-07-26T12:00:00Z",
 "model": {
  "source": "NCEP GFS 0.50 degree",
  "vertical_coordinate": "constant density (isopycnic)",
  "horizon_hours": 168.0,
  "output_interval_min": 30,
  "integration_step_s": 900,
  "wind_field_interval_h": 3
 },
 "members": {
  "offsets_m": [
   -2000,
   -1500,
   -1000,
   -500,
   0,
   500,
   1000,
   1500,
   2000
  ],
  "nominal_offset_m": 0,
  "note": "Each member is seeded at the last observed altitude plus its offset and then conserves the density it started with. The ladder is a sensitivity fan, not a probability distribution: adjacent members diverge by roughly 1,200 km over seven days. levels_spanned reports how many GFS levels the fan actually straddles, usually 2 or 3."
 },
 "files": {
  "trajectories_csv_gz": "PBA_forecast_20260726_12Z.csv.gz",
  "trajectories_geojson_gz": "PBA_forecast_20260726_12Z.geojson.gz"
 },
 "counts": {
  "flights": 23,
  "members": 9,
  "rows": 69606
 },
 "flights": [
  {
   "callsign": "AG6NS-23",
   "flight_id": "AG6NS-23_2026-02-07",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 18:53:40",
   "seed_lat": -54.79167,
   "seed_lon": -53.16665,
   "seed_alt_m": 12420.0,
   "seed_age_h": 3.19,
   "float_reliable": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-02 18:30:00",
    "lat": -46.13401,
    "lon": -94.47608,
    "alt_m": 12402.9
   },
   "member_spread_deg": {
    "lat": 29.21,
    "lon": 123.76
   }
  },
  {
   "callsign": "BSS53",
   "flight_id": "BSS53_2026-03-09",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 18:51:19",
   "seed_lat": 45.72917,
   "seed_lon": -35.83333,
   "seed_alt_m": 13110.0,
   "seed_age_h": 3.22,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 18:15:00",
    "lat": 50.83213,
    "lon": 103.93452,
    "alt_m": 12997.7
   },
   "member_spread_deg": {
    "lat": 35.1,
    "lon": 85.04
   }
  },
  {
   "callsign": "BSS54",
   "flight_id": "BSS54_2026-07-09",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:31:18",
   "seed_lat": 40.97917,
   "seed_lon": -137.08333,
   "seed_alt_m": 14080.0,
   "seed_age_h": 0.56,
   "float_reliable": true,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-02 21:30:00",
    "lat": 36.43724,
    "lon": -42.41546,
    "alt_m": 14536.6
   },
   "member_spread_deg": {
    "lat": 38.62,
    "lon": 139.09
   }
  },
  {
   "callsign": "DG2GG-23",
   "flight_id": "DG2GG-23_2026-05-23",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:09:00",
   "seed_lat": 56.75,
   "seed_lon": -176.20833,
   "seed_alt_m": 12950.0,
   "seed_age_h": 0.93,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 20:45:00",
    "lat": 22.64666,
    "lon": -177.50632,
    "alt_m": 13201.8
   },
   "member_spread_deg": {
    "lat": 26.67,
    "lon": 156.53
   }
  },
  {
   "callsign": "DG2GG-27",
   "flight_id": "DG2GG-27_2026-07-04",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 11:28:00",
   "seed_lat": 49.54167,
   "seed_lon": 89.875,
   "seed_alt_m": 13040.0,
   "seed_age_h": 10.61,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 11:30:00",
    "lat": 42.31418,
    "lon": -162.16032,
    "alt_m": 13651.4
   },
   "member_spread_deg": {
    "lat": 20.68,
    "lon": 339.51
   }
  },
  {
   "callsign": "DJ2DS-34",
   "flight_id": "DJ2DS-34_2026-04-22",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:21:00",
   "seed_lat": 52.60417,
   "seed_lon": -107.125,
   "seed_alt_m": 13300.0,
   "seed_age_h": 0.73,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 20:45:00",
    "lat": 44.77445,
    "lon": 11.60537,
    "alt_m": 13580.3
   },
   "member_spread_deg": {
    "lat": 30.46,
    "lon": 173.63
   }
  },
  {
   "callsign": "DL0MZ-493",
   "flight_id": "DL0MZ-493_2026-07-25",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 16:06:01",
   "seed_lat": 49.625,
   "seed_lon": 25.08333,
   "seed_alt_m": 12400.0,
   "seed_age_h": 5.98,
   "float_reliable": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-02 15:30:00",
    "lat": 55.55334,
    "lon": 167.22821,
    "alt_m": 12452.8
   },
   "member_spread_deg": {
    "lat": 17.87,
    "lon": 355.97
   }
  },
  {
   "callsign": "DL0MZ-493e",
   "flight_id": "DL0MZ-493e_2026-07-25",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 16:06:02",
   "seed_lat": 49.63134,
   "seed_lon": 25.11007,
   "seed_alt_m": 12400.0,
   "seed_age_h": 5.98,
   "float_reliable": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-02 15:30:00",
    "lat": 55.52632,
    "lon": 167.08667,
    "alt_m": 12454.6
   },
   "member_spread_deg": {
    "lat": 16.13,
    "lon": 358.59
   }
  },
  {
   "callsign": "DN3LEO-13",
   "flight_id": "DN3LEO-13_2026-04-12",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:23:00",
   "seed_lat": 77.95833,
   "seed_lon": -62.95833,
   "seed_alt_m": 12130.0,
   "seed_age_h": 0.7,
   "float_reliable": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-02 21:30:00",
    "lat": 70.47147,
    "lon": 75.68228,
    "alt_m": 12292.3
   },
   "member_spread_deg": {
    "lat": 21.18,
    "lon": 115.14
   }
  },
  {
   "callsign": "EI6BFW-18",
   "flight_id": "EI6BFW-18_2026-07-25",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 16:10:30",
   "seed_lat": 50.375,
   "seed_lon": 19.75,
   "seed_alt_m": 13020.0,
   "seed_age_h": 5.9,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 15:45:00",
    "lat": 43.09355,
    "lon": 151.20363,
    "alt_m": 12952.7
   },
   "member_spread_deg": {
    "lat": 26.35,
    "lon": 353.37
   }
  },
  {
   "callsign": "K5NOT-11",
   "flight_id": "K5NOT-11_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:25:37",
   "seed_lat": 52.52078,
   "seed_lon": -108.75,
   "seed_alt_m": 12810.0,
   "seed_age_h": 0.65,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 21:30:00",
    "lat": 46.08471,
    "lon": 69.53006,
    "alt_m": 12770.4
   },
   "member_spread_deg": {
    "lat": 13.36,
    "lon": 136.51
   }
  },
  {
   "callsign": "K9YO-23",
   "flight_id": "K9YO-23_2026-07-13",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 09:45:49",
   "seed_lat": 48.3958,
   "seed_lon": 98.3333,
   "seed_alt_m": 12780.0,
   "seed_age_h": 12.32,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 11:30:00",
    "lat": 26.83636,
    "lon": 125.69523,
    "alt_m": 13187.9
   },
   "member_spread_deg": {
    "lat": 32.92,
    "lon": 295.52
   }
  },
  {
   "callsign": "KC3LBR-449",
   "flight_id": "KC3LBR-449_2026-07-06",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:31:33",
   "seed_lat": 77.60417,
   "seed_lon": 33.75,
   "seed_alt_m": 13020.0,
   "seed_age_h": 0.55,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 21:30:00",
    "lat": 64.63291,
    "lon": -118.44517,
    "alt_m": 13059.0
   },
   "member_spread_deg": {
    "lat": 32.83,
    "lon": 188.55
   }
  },
  {
   "callsign": "KC5TRB-1",
   "flight_id": "KC5TRB-1_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 20:15:43",
   "seed_lat": 57.89578,
   "seed_lon": -51.79163,
   "seed_alt_m": 13030.0,
   "seed_age_h": 1.82,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 19:45:00",
    "lat": 57.08627,
    "lon": 94.12569,
    "alt_m": 12950.6
   },
   "member_spread_deg": {
    "lat": 30.35,
    "lon": 93.96
   }
  },
  {
   "callsign": "KE8RES-8",
   "flight_id": "KE8RES-8_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:21:00",
   "seed_lat": 63.72917,
   "seed_lon": -157.625,
   "seed_alt_m": 12600.0,
   "seed_age_h": 0.73,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 20:45:00",
    "lat": 51.64858,
    "lon": -129.53559,
    "alt_m": 12390.5
   },
   "member_spread_deg": {
    "lat": 34.32,
    "lon": 172.75
   }
  },
  {
   "callsign": "KI1TEN-1",
   "flight_id": "KI1TEN-1_2026-07-23",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:25:27",
   "seed_lat": 31.68746,
   "seed_lon": -118.12496,
   "seed_alt_m": 12300.0,
   "seed_age_h": 0.66,
   "float_reliable": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-02 21:30:00",
    "lat": 33.67988,
    "lon": -104.25375,
    "alt_m": 12315.7
   },
   "member_spread_deg": {
    "lat": 24.59,
    "lon": 89.57
   }
  },
  {
   "callsign": "KI6DS-11",
   "flight_id": "KI6DS-11_2026-02-03",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 21:25:45",
   "seed_lat": 52.81245,
   "seed_lon": -64.91665,
   "seed_alt_m": 13480.0,
   "seed_age_h": 0.65,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 21:30:00",
    "lat": 75.28326,
    "lon": 58.04204,
    "alt_m": 13122.5
   },
   "member_spread_deg": {
    "lat": 25.16,
    "lon": 91.06
   }
  },
  {
   "callsign": "PC4L-11",
   "flight_id": "PC4L-11_2026-07-16",
   "payload_type": "APRS",
   "seed_time": "2026-07-26 12:46:26",
   "seed_lat": 42.93908,
   "seed_lon": 39.39383,
   "seed_alt_m": 11696.0,
   "seed_age_h": 9.31,
   "float_reliable": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-02 12:15:00",
    "lat": 43.39206,
    "lon": 132.00072,
    "alt_m": 12174.4
   },
   "member_spread_deg": {
    "lat": 42.05,
    "lon": 346.03
   }
  },
  {
   "callsign": "SP0LND-6",
   "flight_id": "SP0LND-6_2026-07-25",
   "payload_type": "APRS",
   "seed_time": "2026-07-26 13:19:17",
   "seed_lat": 44.85792,
   "seed_lon": 29.04891,
   "seed_alt_m": 13803.0,
   "seed_age_h": 8.76,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 12:45:00",
    "lat": 61.91649,
    "lon": -176.81855,
    "alt_m": 13540.2
   },
   "member_spread_deg": {
    "lat": 31.72,
    "lon": 354.43
   }
  },
  {
   "callsign": "SP2ROC-41",
   "flight_id": "SP2ROC-41_2026-01-25",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 18:58:00",
   "seed_lat": 47.08333,
   "seed_lon": -33.20833,
   "seed_alt_m": 15770.0,
   "seed_age_h": 3.11,
   "float_reliable": true,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-02 18:30:00",
    "lat": 72.74545,
    "lon": 53.52834,
    "alt_m": 15363.0
   },
   "member_spread_deg": {
    "lat": 27.5,
    "lon": 91.42
   }
  },
  {
   "callsign": "YU9OMT-1",
   "flight_id": "YU9OMT-1_2026-05-24",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 12:50:00",
   "seed_lat": 39.60416,
   "seed_lon": 35.08336,
   "seed_alt_m": 11370.0,
   "seed_age_h": 9.25,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 12:15:00",
    "lat": 66.0999,
    "lon": 136.27853,
    "alt_m": 11466.7
   },
   "member_spread_deg": {
    "lat": 33.82,
    "lon": 342.96
   }
  },
  {
   "callsign": "ZS6SRC-37",
   "flight_id": "ZS6SRC-37_2026-07-15",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 15:49:00",
   "seed_lat": -25.52083,
   "seed_lon": -1.45833,
   "seed_alt_m": 12320.0,
   "seed_age_h": 6.26,
   "float_reliable": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-02 15:15:00",
    "lat": -33.56225,
    "lon": -92.63465,
    "alt_m": 12281.3
   },
   "member_spread_deg": {
    "lat": 14.07,
    "lon": 310.14
   }
  },
  {
   "callsign": "ZS6SRC-84",
   "flight_id": "ZS6SRC-84_2026-07-12",
   "payload_type": "WSPR",
   "seed_time": "2026-07-26 16:15:00",
   "seed_lat": -1.45833,
   "seed_lon": -0.875,
   "seed_alt_m": 12980.0,
   "seed_age_h": 5.83,
   "float_reliable": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-02 15:45:00",
    "lat": -23.29008,
    "lon": 177.21628,
    "alt_m": 12704.0
   },
   "member_spread_deg": {
    "lat": 22.76,
    "lon": 344.54
   }
  }
 ]
}