{
 "generated_utc": "2026-08-14T11:27:31Z",
 "gfs_cycle_utc": "2026-08-14T06:00:00Z",
 "model": {
  "source": "NCEP GFS 0.50 degree",
  "vertical_coordinate": "constant density (isopycnic)",
  "horizon_hours": 491.0,
  "output_interval_min": 30,
  "integration_step_s": 900,
  "wind_field_interval_h": 3
 },
 "staleness": {
  "fresh_seed_max_h": 24.0,
  "served_until_h": 336.0,
  "track_max_age_h": 72.0,
  "region_spread_deg": 60.0,
  "note": "A trajectory is served for 336 h after the last real fix and then the flight disappears. That matches the archive's own bridging limit: 23% of flights go quiet for over a week and are then heard again, so a shorter window drops balloons that are still flying. Past dead_reckoned flights the balloon has not been heard from since seed_time, so its present position is a prediction too -- the silent period is reconstructed from GFS analyses of weather that has already happened, which is why wind_source distinguishes analysis from forecast. Use display_as, not seed_age_h, to decide how to draw a flight: 'track' means the members still agree and a line is meaningful, 'region' means draw the member envelope instead because the nominal member is no better than any other."
 },
 "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_20260814_06Z.csv.gz",
  "trajectories_geojson_gz": "PBA_forecast_20260814_06Z.geojson.gz"
 },
 "counts": {
  "flights": 24,
  "members": 9,
  "rows": 97803
 },
 "flights": [
  {
   "callsign": "AG6NS-23",
   "flight_id": "AG6NS-23_2026-02-07",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 10:38:40",
   "seed_lat": -42.60417,
   "seed_lon": -19.95832,
   "seed_alt_m": 12090.0,
   "seed_age_h": 0.69,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 10:15:00",
    "lat": -41.59673,
    "lon": -64.55192,
    "alt_m": 12323.4
   },
   "member_spread_deg": {
    "lat": 23.88,
    "lon": 70.31
   },
   "member_spread_now_deg": {
    "lat": 0.03,
    "lon": 0.15
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "BSS53",
   "flight_id": "BSS53_2026-03-09",
   "payload_type": "WSPR",
   "seed_time": "2026-08-13 08:30:18",
   "seed_lat": 57.54167,
   "seed_lon": 19.20833,
   "seed_alt_m": 12870.0,
   "seed_age_h": 26.83,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 66.33134,
    "lon": -168.03828,
    "alt_m": 12353.0
   },
   "member_spread_deg": {
    "lat": 27.0,
    "lon": 266.03
   },
   "member_spread_now_deg": {
    "lat": 4.11,
    "lon": 15.73
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "BSS54",
   "flight_id": "BSS54_2026-07-09",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 02:55:18",
   "seed_lat": 49.58333,
   "seed_lon": 145.16667,
   "seed_alt_m": 14330.0,
   "seed_age_h": 8.41,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 57.62011,
    "lon": -120.19964,
    "alt_m": 13798.1
   },
   "member_spread_deg": {
    "lat": 26.99,
    "lon": 307.69
   },
   "member_spread_now_deg": {
    "lat": 1.54,
    "lon": 3.49
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DG2GG-23",
   "flight_id": "DG2GG-23_2026-05-23",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 10:34:00",
   "seed_lat": 51.1875,
   "seed_lon": 13.70833,
   "seed_alt_m": 12920.0,
   "seed_age_h": 0.77,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 10:00:00",
    "lat": 46.71861,
    "lon": -167.87173,
    "alt_m": 12926.7
   },
   "member_spread_deg": {
    "lat": 7.73,
    "lon": 316.76
   },
   "member_spread_now_deg": {
    "lat": 0.04,
    "lon": 0.09
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DG2GG-27",
   "flight_id": "DG2GG-27_2026-07-04",
   "payload_type": "WSPR",
   "seed_time": "2026-08-10 00:18:00",
   "seed_lat": 17.10417,
   "seed_lon": -113.33333,
   "seed_alt_m": 14010.0,
   "seed_age_h": 107.03,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-21 05:45:00",
    "lat": 17.05,
    "lon": -111.7158,
    "alt_m": 14060.1
   },
   "member_spread_deg": {
    "lat": 31.37,
    "lon": 125.61
   },
   "member_spread_now_deg": {
    "lat": 29.24,
    "lon": 53.32
   },
   "display_as": "region",
   "display_reason": "seed_age"
  },
  {
   "callsign": "DG2GG-29",
   "flight_id": "DG2GG-29_2026-07-28",
   "payload_type": "WSPR",
   "seed_time": "2026-08-04 04:57:00",
   "seed_lat": 46.91667,
   "seed_lon": 165.25,
   "seed_alt_m": 13380.0,
   "seed_age_h": 246.38,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 39.67072,
    "lon": 7.7051,
    "alt_m": 13359.2
   },
   "member_spread_deg": {
    "lat": 97.1,
    "lon": 277.41
   },
   "member_spread_now_deg": {
    "lat": 66.13,
    "lon": 236.19
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "DG2GG-30",
   "flight_id": "DG2GG-30_2026-08-07",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 03:01:00",
   "seed_lat": 48.25,
   "seed_lon": -163.70833,
   "seed_alt_m": 12760.0,
   "seed_age_h": 8.32,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 52.79544,
    "lon": 50.01652,
    "alt_m": 12403.9
   },
   "member_spread_deg": {
    "lat": 11.28,
    "lon": 196.67
   },
   "member_spread_now_deg": {
    "lat": 3.36,
    "lon": 5.84
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DN3LEO-13",
   "flight_id": "DN3LEO-13_2026-04-12",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 10:53:00",
   "seed_lat": 69.8125,
   "seed_lon": 53.625,
   "seed_alt_m": 12120.0,
   "seed_age_h": 0.45,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 11:00:00",
    "lat": 72.54813,
    "lon": 171.51369,
    "alt_m": 11751.3
   },
   "member_spread_deg": {
    "lat": 24.47,
    "lon": 330.26
   },
   "member_spread_now_deg": {
    "lat": 0.11,
    "lon": 0.11
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "EI6BFW-18",
   "flight_id": "EI6BFW-18_2026-07-25",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 01:53:00",
   "seed_lat": 69.41667,
   "seed_lon": -134.375,
   "seed_alt_m": 12640.0,
   "seed_age_h": 9.45,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 61.22478,
    "lon": -24.56962,
    "alt_m": 12607.0
   },
   "member_spread_deg": {
    "lat": 14.15,
    "lon": 144.63
   },
   "member_spread_now_deg": {
    "lat": 1.81,
    "lon": 12.04
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "K5NOT-11",
   "flight_id": "K5NOT-11_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 00:45:37",
   "seed_lat": 24.99994,
   "seed_lon": -130.04167,
   "seed_alt_m": 13360.0,
   "seed_age_h": 10.57,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:45:00",
    "lat": 18.0567,
    "lon": -65.04762,
    "alt_m": 13476.5
   },
   "member_spread_deg": {
    "lat": 33.29,
    "lon": 156.64
   },
   "member_spread_now_deg": {
    "lat": 3.65,
    "lon": 4.9
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KC3LBR-449",
   "flight_id": "KC3LBR-449_2026-07-06",
   "payload_type": "WSPR",
   "seed_time": "2026-08-13 15:22:33",
   "seed_lat": 50.66667,
   "seed_lon": 25.54167,
   "seed_alt_m": 13700.0,
   "seed_age_h": 19.96,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 65.63309,
    "lon": 66.62854,
    "alt_m": 13448.8
   },
   "member_spread_deg": {
    "lat": 31.53,
    "lon": 338.64
   },
   "member_spread_now_deg": {
    "lat": 1.92,
    "lon": 12.82
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KC5TRB-1",
   "flight_id": "KC5TRB-1_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-08-12 11:40:43",
   "seed_lat": 57.39578,
   "seed_lon": 26.00003,
   "seed_alt_m": 12570.0,
   "seed_age_h": 47.66,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:45:00",
    "lat": 57.77242,
    "lon": 72.12571,
    "alt_m": 12426.1
   },
   "member_spread_deg": {
    "lat": 18.26,
    "lon": 258.17
   },
   "member_spread_now_deg": {
    "lat": 11.52,
    "lon": 30.38
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KD7FXO-1",
   "flight_id": "KD7FXO-1_2026-08-02",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 10:35:00",
   "seed_lat": 41.70833,
   "seed_lon": 5.75,
   "seed_alt_m": 13000.0,
   "seed_age_h": 0.75,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 10:00:00",
    "lat": 31.49863,
    "lon": 145.5106,
    "alt_m": 13103.2
   },
   "member_spread_deg": {
    "lat": 25.96,
    "lon": 353.88
   },
   "member_spread_now_deg": {
    "lat": 0.05,
    "lon": 0.14
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KE8RES-8",
   "flight_id": "KE8RES-8_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-08-13 20:31:00",
   "seed_lat": 52.66667,
   "seed_lon": -65.0,
   "seed_alt_m": 12140.0,
   "seed_age_h": 14.82,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 83.93432,
    "lon": 69.9086,
    "alt_m": 11963.1
   },
   "member_spread_deg": {
    "lat": 28.05,
    "lon": 143.59
   },
   "member_spread_now_deg": {
    "lat": 0.91,
    "lon": 2.56
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KE9DAB-11",
   "flight_id": "KE9DAB-11_2026-07-29",
   "payload_type": "WSPR",
   "seed_time": "2026-08-13 21:11:00",
   "seed_lat": 63.66667,
   "seed_lon": 161.54167,
   "seed_alt_m": 10970.0,
   "seed_age_h": 14.15,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 05:45:00",
    "lat": 32.48943,
    "lon": -57.94894,
    "alt_m": 11148.5
   },
   "member_spread_deg": {
    "lat": 49.79,
    "lon": 110.69
   },
   "member_spread_now_deg": {
    "lat": 9.55,
    "lon": 5.92
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KI1TEN-1",
   "flight_id": "KI1TEN-1_2026-07-23",
   "payload_type": "WSPR",
   "seed_time": "2026-08-01 22:55:27",
   "seed_lat": 23.95828,
   "seed_lon": -104.12496,
   "seed_alt_m": 12380.0,
   "seed_age_h": 300.41,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": -22.07699,
    "lon": -86.795,
    "alt_m": 12294.8
   },
   "member_spread_deg": {
    "lat": 56.44,
    "lon": 136.61
   },
   "member_spread_now_deg": {
    "lat": 21.01,
    "lon": 64.63
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "KI6DS-11",
   "flight_id": "KI6DS-11_2026-02-03",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 10:45:45",
   "seed_lat": 78.45828,
   "seed_lon": 94.29169,
   "seed_alt_m": 13240.0,
   "seed_age_h": 0.57,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 10:15:00",
    "lat": 59.73777,
    "lon": -161.13366,
    "alt_m": 12940.2
   },
   "member_spread_deg": {
    "lat": 26.25,
    "lon": 345.33
   },
   "member_spread_now_deg": {
    "lat": 0.02,
    "lon": 0.47
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "SP2ROC-41",
   "flight_id": "SP2ROC-41_2026-01-25",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 05:03:00",
   "seed_lat": 21.10417,
   "seed_lon": 174.5,
   "seed_alt_m": 16470.0,
   "seed_age_h": 6.28,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 6.954,
    "lon": 59.36192,
    "alt_m": 16479.6
   },
   "member_spread_deg": {
    "lat": 38.3,
    "lon": 79.39
   },
   "member_spread_now_deg": {
    "lat": 2.17,
    "lon": 1.57
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "SP6MPL-34",
   "flight_id": "SP6MPL-34_2025-12-03",
   "payload_type": "WSPR",
   "seed_time": "2026-07-31 18:52:00",
   "seed_lat": 74.5625,
   "seed_lon": -160.0,
   "seed_alt_m": 12890.0,
   "seed_age_h": 328.47,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:45:00",
    "lat": 39.47751,
    "lon": -130.92514,
    "alt_m": 13354.2
   },
   "member_spread_deg": {
    "lat": 51.02,
    "lon": 309.01
   },
   "member_spread_now_deg": {
    "lat": 16.59,
    "lon": 345.03
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "SP6MPL-9",
   "flight_id": "SP6MPL-9_2026-08-02",
   "payload_type": "APRS",
   "seed_time": "2026-08-04 04:05:45",
   "seed_lat": 45.52942,
   "seed_lon": 75.286,
   "seed_alt_m": 12836.0,
   "seed_age_h": 247.24,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 48.14345,
    "lon": -149.92824,
    "alt_m": 12986.2
   },
   "member_spread_deg": {
    "lat": 38.17,
    "lon": 338.39
   },
   "member_spread_now_deg": {
    "lat": 39.64,
    "lon": 233.81
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "VE3VRO-36",
   "flight_id": "VE3VRO-36_2026-07-30",
   "payload_type": "WSPR",
   "seed_time": "2026-08-12 22:41:00",
   "seed_lat": 45.875,
   "seed_lon": 142.66667,
   "seed_alt_m": 13600.0,
   "seed_age_h": 36.65,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:45:00",
    "lat": 40.9758,
    "lon": -93.51423,
    "alt_m": 13332.7
   },
   "member_spread_deg": {
    "lat": 18.52,
    "lon": 269.26
   },
   "member_spread_now_deg": {
    "lat": 12.05,
    "lon": 18.73
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "W0RBO-12",
   "flight_id": "W0RBO-12_2026-05-02",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 02:05:23",
   "seed_lat": 54.52078,
   "seed_lon": 141.29169,
   "seed_alt_m": 13630.0,
   "seed_age_h": 9.24,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 05:30:00",
    "lat": 73.8638,
    "lon": -114.60662,
    "alt_m": 12975.1
   },
   "member_spread_deg": {
    "lat": 41.21,
    "lon": 49.04
   },
   "member_spread_now_deg": {
    "lat": 6.34,
    "lon": 9.58
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "ZS6SRC-37",
   "flight_id": "ZS6SRC-37_2026-07-31",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 05:39:00",
   "seed_lat": -23.64583,
   "seed_lon": 119.66667,
   "seed_alt_m": 12290.0,
   "seed_age_h": 5.68,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 05:45:00",
    "lat": -25.70403,
    "lon": 2.63505,
    "alt_m": 12547.6
   },
   "member_spread_deg": {
    "lat": 34.2,
    "lon": 264.65
   },
   "member_spread_now_deg": {
    "lat": 2.45,
    "lon": 3.04
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "ZS6SRC-39",
   "flight_id": "ZS6SRC-39_2026-08-05",
   "payload_type": "WSPR",
   "seed_time": "2026-08-12 06:21:00",
   "seed_lat": -22.16667,
   "seed_lon": 146.45833,
   "seed_alt_m": 15900.0,
   "seed_age_h": 52.98,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-21 05:45:00",
    "lat": -9.27893,
    "lon": -20.89461,
    "alt_m": 15967.5
   },
   "member_spread_deg": {
    "lat": 24.08,
    "lon": 159.42
   },
   "member_spread_now_deg": {
    "lat": 7.98,
    "lon": 352.65
   },
   "display_as": "region",
   "display_reason": "member_spread"
  }
 ]
}