{
 "generated_utc": "2026-08-15T05:27:12Z",
 "gfs_cycle_utc": "2026-08-15T00:00:00Z",
 "model": {
  "source": "NCEP GFS 0.50 degree",
  "vertical_coordinate": "constant density (isopycnic)",
  "horizon_hours": 480.5,
  "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_20260815_00Z.csv.gz",
  "trajectories_geojson_gz": "PBA_forecast_20260815_00Z.geojson.gz"
 },
 "counts": {
  "flights": 24,
  "members": 9,
  "rows": 93708
 },
 "flights": [
  {
   "callsign": "AG6NS-23",
   "flight_id": "AG6NS-23_2026-02-07",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 16:58:40",
   "seed_lat": -43.83333,
   "seed_lon": -10.49999,
   "seed_alt_m": 12150.0,
   "seed_age_h": 12.36,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 23:30:00",
    "lat": -53.68963,
    "lon": -34.56942,
    "alt_m": 12468.2
   },
   "member_spread_deg": {
    "lat": 20.38,
    "lon": 54.17
   },
   "member_spread_now_deg": {
    "lat": 1.44,
    "lon": 8.19
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "BSS53",
   "flight_id": "BSS53_2026-03-09",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 04:55:19",
   "seed_lat": 52.9375,
   "seed_lon": 69.04167,
   "seed_alt_m": 12830.0,
   "seed_age_h": 0.41,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-22 05:00:00",
    "lat": 48.58991,
    "lon": -137.07553,
    "alt_m": 13010.8
   },
   "member_spread_deg": {
    "lat": 44.21,
    "lon": 39.46
   },
   "member_spread_now_deg": {
    "lat": 0.07,
    "lon": 0.21
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "BSS54",
   "flight_id": "BSS54_2026-07-09",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 00:19:47",
   "seed_lat": 52.1875,
   "seed_lon": 154.5,
   "seed_alt_m": 14180.0,
   "seed_age_h": 5.0,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
    "lat": 47.32218,
    "lon": -91.33055,
    "alt_m": 14072.6
   },
   "member_spread_deg": {
    "lat": 30.7,
    "lon": 86.42
   },
   "member_spread_now_deg": {
    "lat": 0.61,
    "lon": 2.18
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DG2GG-23",
   "flight_id": "DG2GG-23_2026-05-23",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 15:44:00",
   "seed_lat": 50.4375,
   "seed_lon": 16.625,
   "seed_alt_m": 12880.0,
   "seed_age_h": 13.6,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
    "lat": 40.2842,
    "lon": -161.82148,
    "alt_m": 13061.2
   },
   "member_spread_deg": {
    "lat": 17.76,
    "lon": 335.99
   },
   "member_spread_now_deg": {
    "lat": 1.38,
    "lon": 2.2
   },
   "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": 125.03,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
    "lat": 9.47504,
    "lon": -82.89851,
    "alt_m": 14108.5
   },
   "member_spread_deg": {
    "lat": 37.12,
    "lon": 150.89
   },
   "member_spread_now_deg": {
    "lat": 30.99,
    "lon": 59.11
   },
   "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": 264.38,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:30:00",
    "lat": 41.44721,
    "lon": 51.27556,
    "alt_m": 13328.9
   },
   "member_spread_deg": {
    "lat": 88.19,
    "lon": 265.23
   },
   "member_spread_now_deg": {
    "lat": 69.47,
    "lon": 224.38
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "DG2GG-30",
   "flight_id": "DG2GG-30_2026-08-07",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 02:06:00",
   "seed_lat": 35.66667,
   "seed_lon": -137.58333,
   "seed_alt_m": 13020.0,
   "seed_age_h": 3.23,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-22 01:30:00",
    "lat": 53.48594,
    "lon": 66.50609,
    "alt_m": 12535.1
   },
   "member_spread_deg": {
    "lat": 22.01,
    "lon": 108.7
   },
   "member_spread_now_deg": {
    "lat": 0.93,
    "lon": 1.59
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DG2GG-31",
   "flight_id": "DG2GG-31_2026-08-13",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 15:47:00",
   "seed_lat": 44.10417,
   "seed_lon": 10.33333,
   "seed_alt_m": 13300.0,
   "seed_age_h": 13.55,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
    "lat": 55.50367,
    "lon": -160.09985,
    "alt_m": 13151.9
   },
   "member_spread_deg": {
    "lat": 15.95,
    "lon": 349.14
   },
   "member_spread_now_deg": {
    "lat": 0.23,
    "lon": 1.26
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DN3LEO-13",
   "flight_id": "DN3LEO-13_2026-04-12",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 04:53:00",
   "seed_lat": 79.10417,
   "seed_lon": 82.66667,
   "seed_alt_m": 11960.0,
   "seed_age_h": 0.45,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-22 05:00:00",
    "lat": 75.81809,
    "lon": 140.66316,
    "alt_m": 11641.0
   },
   "member_spread_deg": {
    "lat": 14.45,
    "lon": 342.62
   },
   "member_spread_now_deg": {
    "lat": 0.28,
    "lon": 0.93
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "EI6BFW-18",
   "flight_id": "EI6BFW-18_2026-07-25",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 00:23:00",
   "seed_lat": 63.79167,
   "seed_lon": -116.41667,
   "seed_alt_m": 12610.0,
   "seed_age_h": 4.95,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-22 00:00:00",
    "lat": 54.86692,
    "lon": -3.7061,
    "alt_m": 12503.4
   },
   "member_spread_deg": {
    "lat": 17.02,
    "lon": 186.61
   },
   "member_spread_now_deg": {
    "lat": 0.69,
    "lon": 4.19
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "K5NOT-11",
   "flight_id": "K5NOT-11_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 23:10:37",
   "seed_lat": 39.08328,
   "seed_lon": -111.83333,
   "seed_alt_m": 13090.0,
   "seed_age_h": 6.16,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
    "lat": 33.00069,
    "lon": -4.50722,
    "alt_m": 13205.9
   },
   "member_spread_deg": {
    "lat": 21.26,
    "lon": 92.31
   },
   "member_spread_now_deg": {
    "lat": 4.11,
    "lon": 3.1
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KC3LBR-449",
   "flight_id": "KC3LBR-449_2026-07-06",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 15:22:33",
   "seed_lat": 50.70833,
   "seed_lon": 58.5,
   "seed_alt_m": 13420.0,
   "seed_age_h": 13.96,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:30:00",
    "lat": 55.67954,
    "lon": 99.77809,
    "alt_m": 13297.6
   },
   "member_spread_deg": {
    "lat": 21.93,
    "lon": 274.31
   },
   "member_spread_now_deg": {
    "lat": 5.98,
    "lon": 6.49
   },
   "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": 65.66,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
    "lat": 61.55323,
    "lon": 73.31236,
    "alt_m": 12535.5
   },
   "member_spread_deg": {
    "lat": 11.54,
    "lon": 275.15
   },
   "member_spread_now_deg": {
    "lat": 30.37,
    "lon": 71.08
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "KD7FXO-1",
   "flight_id": "KD7FXO-1_2026-08-02",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 17:15:00",
   "seed_lat": 40.35417,
   "seed_lon": 8.16667,
   "seed_alt_m": 12920.0,
   "seed_age_h": 12.08,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
    "lat": 35.97965,
    "lon": -175.02658,
    "alt_m": 13007.8
   },
   "member_spread_deg": {
    "lat": 7.83,
    "lon": 331.66
   },
   "member_spread_now_deg": {
    "lat": 0.9,
    "lon": 4.45
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KE8RES-8",
   "flight_id": "KE8RES-8_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-08-14 18:56:00",
   "seed_lat": 55.5625,
   "seed_lon": -55.125,
   "seed_alt_m": 12260.0,
   "seed_age_h": 10.4,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 23:30:00",
    "lat": 68.44329,
    "lon": 16.20364,
    "alt_m": 12082.7
   },
   "member_spread_deg": {
    "lat": 19.78,
    "lon": 17.18
   },
   "member_spread_now_deg": {
    "lat": 2.03,
    "lon": 1.2
   },
   "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": 32.15,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
    "lat": 31.63291,
    "lon": -79.80841,
    "alt_m": 11171.9
   },
   "member_spread_deg": {
    "lat": 33.4,
    "lon": 78.64
   },
   "member_spread_now_deg": {
    "lat": 5.68,
    "lon": 8.81
   },
   "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": 318.41,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-21 23:30:00",
    "lat": -22.45028,
    "lon": -76.92972,
    "alt_m": 12305.5
   },
   "member_spread_deg": {
    "lat": 38.35,
    "lon": 146.26
   },
   "member_spread_now_deg": {
    "lat": 27.17,
    "lon": 70.67
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "KI6DS-11",
   "flight_id": "KI6DS-11_2026-02-03",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 04:43:15",
   "seed_lat": 76.20828,
   "seed_lon": 108.45835,
   "seed_alt_m": 13240.0,
   "seed_age_h": 0.61,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-22 04:15:00",
    "lat": 81.25886,
    "lon": 164.6073,
    "alt_m": 12856.6
   },
   "member_spread_deg": {
    "lat": 24.93,
    "lon": 347.65
   },
   "member_spread_now_deg": {
    "lat": 0.16,
    "lon": 0.05
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "SP2ROC-41",
   "flight_id": "SP2ROC-41_2026-01-25",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 04:51:00",
   "seed_lat": 16.0625,
   "seed_lon": 163.25,
   "seed_alt_m": 16560.0,
   "seed_age_h": 0.48,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-22 04:15:00",
    "lat": 9.82028,
    "lon": 48.60447,
    "alt_m": 16410.3
   },
   "member_spread_deg": {
    "lat": 35.87,
    "lon": 70.88
   },
   "member_spread_now_deg": {
    "lat": 0.18,
    "lon": 0.06
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "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": 265.24,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:30:00",
    "lat": 36.01108,
    "lon": -157.35452,
    "alt_m": 13125.1
   },
   "member_spread_deg": {
    "lat": 46.5,
    "lon": 353.28
   },
   "member_spread_now_deg": {
    "lat": 32.03,
    "lon": 238.33
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "VE3VRO-36",
   "flight_id": "VE3VRO-36_2026-07-30",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 04:51:00",
   "seed_lat": 49.8125,
   "seed_lon": 151.0,
   "seed_alt_m": 13440.0,
   "seed_age_h": 0.48,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-22 04:15:00",
    "lat": 44.3112,
    "lon": -72.05816,
    "alt_m": 13226.1
   },
   "member_spread_deg": {
    "lat": 35.86,
    "lon": 116.09
   },
   "member_spread_now_deg": {
    "lat": 0.1,
    "lon": 0.31
   },
   "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": 27.24,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-21 23:30:00",
    "lat": 62.35764,
    "lon": -106.87507,
    "alt_m": 13141.2
   },
   "member_spread_deg": {
    "lat": 22.39,
    "lon": 82.18
   },
   "member_spread_now_deg": {
    "lat": 7.93,
    "lon": 358.62
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "ZS6SRC-37",
   "flight_id": "ZS6SRC-37_2026-07-31",
   "payload_type": "WSPR",
   "seed_time": "2026-08-15 04:04:00",
   "seed_lat": -24.3125,
   "seed_lon": 156.91667,
   "seed_alt_m": 12420.0,
   "seed_age_h": 1.27,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-22 03:30:00",
    "lat": -28.8157,
    "lon": 41.03406,
    "alt_m": 12575.5
   },
   "member_spread_deg": {
    "lat": 30.28,
    "lon": 53.12
   },
   "member_spread_now_deg": {
    "lat": 0.45,
    "lon": 1.15
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
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   "flight_id": "ZS6SRC-39_2026-08-05",
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   "seed_lon": 146.45833,
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   "seed_age_h": 70.98,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-21 23:45:00",
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   },
   "member_spread_deg": {
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   "member_spread_now_deg": {
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   "display_as": "region",
   "display_reason": "member_spread"
  }
 ]
}