Can a model trace the UFO's drift?

Introduction

Trajectory modelling is one of the most useful ways to test whether a reported UFO could have been a balloon, lantern or other wind-driven object. Rather than asking only whether winds were present, investigators can use meteorological data to estimate where a drifting object would have travelled if released from a particular location, at a particular time and altitude. When the predicted path resembles the reported movement, a balloon explanation becomes more plausible. When repeated model runs fail to reproduce the sighting, the balloon hypothesis becomes weaker.

The key point is that trajectory models are tests of consistency, not proof. A successful match shows that known winds could have carried an object along a path similar to the reported one. It does not demonstrate that a balloon was actually present. Likewise, a poor match may reflect uncertainty in the starting assumptions rather than a definitive rejection of the balloon explanation. Modern trajectory tools therefore work best when used as probability assessments rather than simple yes-or-no verdicts.[ready.noaa.gov]ready.noaa.govNOAA HYSPLIT Trajectory ModelEach member of the trajectory ensemble is calculated by offsetting the meteorological data by a fixed grid f…

Can a model trace the UFO’s drift?

Trajectory models calculate how an object would move through the atmosphere when carried by changing winds. The most widely used systems, such as NOAA’s Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT), were developed for atmospheric transport studies but are equally useful for reconstructing potential balloon paths. These models combine weather observations and forecast data with assumptions about an object’s location and altitude to generate a projected track.[Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…[American Meteorological Society Journals]journals.ametsoc.orgAmerican Meteorological Society JournalsNOAA's HYSPLIT Atmospheric Transport and Dispersion…by AF Stein · 2015 · Cited by 6803 — HYSPL…

In a suspected balloon sighting, investigators typically compare two tracks:

• The reported path reconstructed from witness observations, photographs or video.
• The modelled path generated from weather data.[aoml.noaa.gov]aoml.noaa.govupper air observationsAir Observations: How Weather Balloons Improve…1 Sept 2017 — Weather balloons, also known as radiosondes, provide detailed and reliabl…

If the directions, speeds and timing broadly agree, the result supports the possibility that the object drifted with the wind. This approach is particularly valuable when witnesses report slow movement, gradual course changes or long-duration visibility, all of which are characteristic of drifting objects rather than powered aircraft.[Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…

A practical example comes from weather-balloon and radiosonde tracking. Thousands of balloon flights are routinely predicted and reconstructed using trajectory software because wind fields largely determine their movement. Balloon-recovery communities and meteorological agencies use these methods to estimate landing zones and flight paths with reasonable success.[Stratoflights]stratoflights.comPredicting the Weather Balloon flight pathThis tool will help you to predict the estimated flight path of your high altitude…[SondeHub]sondehub.orgSondeHub TrackerLive tracking of radiosonde flights. Data via SondeHub v2. Includes weather overlay, predictions, and access to h…

What a trajectory model can and cannot prove

A trajectory model can demonstrate that a reported movement is physically compatible with known atmospheric conditions. It can also identify whether a claimed route would require winds that did not exist at plausible altitudes.[PMC]pmc.ncbi.nlm.nih.govby H Hou · 2023 · Cited by 8 — HYSPLIT calculates forward and backward trajectories of particles based on wind speed, wind direction…

However, the model cannot establish:

A close match between modelled and observed tracks should therefore be treated as supporting evidence rather than conclusive identification. Conversely, a mismatch is not necessarily fatal to the balloon hypothesis if the starting assumptions remain uncertain.[Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…

Start point, time and altitude choices

The most difficult part of trajectory testing is often selecting the starting conditions. Small changes in launch time or altitude can produce substantially different paths because atmospheric winds vary with height and evolve over time.[NASA Open Data Portal]data.nasa.govNASA Open Data PortalWind Profile Data: Radiosonde (FIFE) - Dataset1 Apr 2025 — The wind profile data described in this document were der…

For suspected balloon sightings, investigators commonly explore multiple possibilities:

This matters because a drifting object may pass through several wind layers during a single observation. A balloon released near the ground might initially travel east, then curve north after rising into a different air current. Witnesses sometimes interpret such changes as controlled manoeuvres even when they are consistent with atmospheric transport.[Reddit]reddit.comHow is the spy balloon steerable?r/askscienceFebruary 11, 2023 — Balloons are “steerable” by changing altitude to find winds in a different direction. Altitude change is…Published: February 11, 2023

Altitude assumptions are especially important. NOAA’s trajectory tools include options to test paths from multiple starting heights because atmospheric transport can differ dramatically between layers separated by only a few hundred metres.[Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…

A strong analysis therefore avoids selecting a single preferred altitude and instead examines a range of realistic heights that fit the reported object.

Why ensemble paths matter for uncertainty

One of the most common mistakes in UFO investigations is treating a single trajectory line as if it were an exact reconstruction. Atmospheric scientists generally avoid this approach because every trajectory contains uncertainty. Weather observations are incomplete, models have finite resolution and the object’s true starting conditions may be unknown.[Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…

For that reason, many trajectory systems provide ensemble calculations. Instead of producing one path, they generate multiple trajectories by slightly altering the starting position, altitude or meteorological inputs. NOAA’s HYSPLIT ensemble option, for example, automatically computes numerous nearby trajectories to show how sensitive the result is to small changes in assumptions.[ready.noaa.gov]ready.noaa.govREAD YBalloon Flight Forecasting ToolsMay 12, 2025 — HYSPLIT Trajectory Optimization. This program developed at ARL (Draxler, 1996) can be used…Published: May 12, 2025

The difference between a single trajectory and an ensemble can be crucial:

For UFO analysis, the most persuasive result is often not a perfect overlap but a situation where the reported path falls within a realistic envelope of ensemble solutions. That demonstrates compatibility with known winds while honestly acknowledging uncertainty.[Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…

When trajectory matches become meaningful

A trajectory result becomes more informative when independent evidence points in the same direction. Examples include:

Trajectory modelling is strongest when it forms part of a larger evidential picture rather than standing alone. A model that places a potential balloon directly along the reported route at the correct time is far more persuasive when supported by known launch activity or documented atmospheric balloon operations.[SondeHub]sondehub.orgSondeHub TrackerLive tracking of radiosonde flights. Data via SondeHub v2. Includes weather overlay, predictions, and access to h…[2SQ6KXY Radiosonde Tracker]radiosondy.infoSQ6KXY Radiosonde Tracker DatabaseGet Data. Radiosondes of last 48 hours: Show Table. Show Map. Last Status Changes: Number. Type. Launch…

The practical value of trajectory testing

Within investigations of UFO reports, trajectory modelling provides a way to move beyond intuition. Witnesses often estimate motion against a background of unknown distance, uncertain altitude and changing perspective. Wind-based modelling introduces an objective test: could a free-floating object have followed a similar route under the atmospheric conditions that actually existed?

The answer is rarely absolute. Yet when multiple trajectory runs, realistic altitude assumptions and ensemble analyses all point toward the same drifting path, the balloon explanation becomes substantially stronger than a simple visual guess. Equally important, when plausible trajectories repeatedly fail to match the reported movement, investigators gain a clearer understanding of where the balloon hypothesis may fall short.[Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…[Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…

Amazon book picks

Further Reading

Books and field guides related to Can a model trace the UFO's drift?. Use these as the next step if you want deeper reading beyond the article.

Book

The UFO Experience

By Joseph Allen Hynek

Connects model-based drift testing to the broader process of UFO case evaluation.

See on Amazon

Book

The Signal and the Noise

By Nate Silver

Useful for understanding modelling uncertainty, probability and limits of inference.

See on Amazon

Book

How to Lie with Statistics

By Darrell Huff

Reinforces caution about overclaiming from uncertain model outputs.

See on Amazon

Book

The UFO Experience, A Scientific Inquiry

By J. Allen Hynek

First published 1972.

See on Amazon

Browse more on Amazon: The UFO Experience The Signal and the Noise How to Lie with Statistics

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Endnotes

1. Source: ready.noaa.gov
Link:https://www.ready.noaa.gov/hypub-bin/trajtype.pl

2. Source: arl.noaa.gov
Title: Air Resources Laboratory HYSPLIT
Link:https://www.arl.noaa.gov/hysplit/

3. Source: arl.noaa.gov
Title: Air Resources Laboratory HYSPLIT User’s Guide
Link:https://www.arl.noaa.gov/documents/reports/hysplit_user_guide.pdf

4. Source: arl.noaa.gov
Link:https://www.arl.noaa.gov/research/atmospheric-transport-and-dispersion/atd-programs-ready/

5. Source: arl.noaa.gov
Title: balloon flight forecasting tools
Link:https://www.arl.noaa.gov/hysplit/getrun-hysplit/balloon-flight-forecasting-tools/

6. Source: stratoflights.com
Link:https://www.stratoflights.com/en/tutorial/weather-balloon-tools/predicting-the-flight-path/

7. Source: sondehub.org
Link:https://sondehub.org/

8. Source: data.nasa.gov
Link:https://data.nasa.gov/dataset/wind-profile-data-radiosonde-fife-bca10

9. Source: arl.noaa.gov
Title: Air Resources Laboratory HYSPLIT
Link:https://www.arl.noaa.gov/documents/workshop/NAQC2007/HTML_Docs/trajerro.html

10. Source: arl.noaa.gov
Title: Air Resources Laboratory HYSPLIT
Link:https://www.arl.noaa.gov/documents/workshop/NAQC2007/HTML_Docs/trajmult.html

11. Source: reddit.com
Title: How is the spy balloon steerable?
Link:https://www.reddit.com/r/askscience/comments/10zoxa0/how_is_the_spy_balloon_steerable/

Published: February 11, 2023

12. Source: aoml.noaa.gov
Title: upper air observations
Link:https://www.aoml.noaa.gov/upper-air-observations/

13. Source: ready.noaa.gov
Title: READ Y
Link:https://www.ready.noaa.gov/READY_balloon.php

Published: May 12, 2025

14. Source: noaa.gov
Link:https://www.noaa.gov/jetstream/upperair/radiosondes

15. Source: noaa.gov
Link:https://www.noaa.gov/

16. Source: ready.noaa.gov
Title: Cheat Sheet 2020
Link:https://www.ready.noaa.gov/documents/ppts/Cheat_Sheet_2020.pdf

17. Source: ready.noaa.gov
Title: HYSPLIT traj
Link:https://www.ready.noaa.gov/HYSPLIT_traj.php

Published: May 2025

18. Source: ready.noaa.gov
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19. Source: www-n-bbs.arl.noaa.gov
Link:https://www-n-bbs.arl.noaa.gov/viewtopic.php?t=2704

20. Source: ready.noaa.gov
Link:https://www.ready.noaa.gov/HYSPLIT.php

Published: May 2025

21. Source: weather.gov
Link:https://www.weather.gov/

22. Source: weather.gov
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23. Source: weather.gov
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25. Source: journals.ametsoc.org
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26. Source: radiosondy.info
Link:https://radiosondy.info/

27. Source: balloonwiki.org
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28. Source: Wikipedia
Title: Weather balloon
Link:https://en.wikipedia.org/wiki/Weather_balloon

29. Source: Wikipedia
Link:https://en.wikipedia.org/wiki/HYSPLIT

30. Source: mce2.org
Link:https://mce2.org/wmogurme/images/workshops/ASEAN/day1/saide/HYSPLIT.pdf

31. Source: www2.atmos.umd.edu
Link:https://www2.atmos.umd.edu/~tcanty/hysplit/today/index.htm

Additional References

32. Source: hurricanescience.org
Link:https://hurricanescience.org/science/observation/landbased/radiosonde/index.html

33. Source: researchgate.net
Link:https://www.researchgate.net/publication/275223272_Investigation_of_the_Effects_of_Considering_Balloon_Drift_Information_on_Radiosonde_Data_Assimilation_Using_the_Four-Dimensional_Variational_Method

34. Source: researchgate.net
Link:https://www.researchgate.net/publication/356315630_Moisture_trajectories_during_heavy_rainfall_events_using_Hybrid_Single-Particle_Lagrangian_Integrated_Trajectory_HYSPLIT_model

35. Source: news.fsu.edu
Link:https://news.fsu.edu/news/expert-pitches/2023/02/15/weather-ballons-and-ufos-fsu-professor-offers-historical-perspective-on-aerial-surveillance/

36. Source: wired.com
Link:https://www.wired.com/story/radiosonde-hunters

37. Source: pmc.ncbi.nlm.nih.gov
Link:https://pmc.ncbi.nlm.nih.gov/articles/PMC9864114/

38. Source: youtube.com
Link:https://www.youtube.com/watch?v=rtMS7_9yNmM

39. Source: instagram.com
Title: NOA A (@noaa) • Instagram photos and videos Official feed for the U.S
Link:https://www.instagram.com/noaa/?hl=en

40. Source: researchgate.net
Link:https://www.researchgate.net/publication/270514931_A_comparison_of_HYSPLIT_backward_trajectories_generated_from_two_GDAS_datasets

41. Source: researchgate.net
Title: 229043431 Global radiosonde balloon drift statistics
Link:https://www.researchgate.net/publication/229043431_Global_radiosonde_balloon_drift_statistics