Within IFOs
When Weather Makes Shapes in the Sky
Cloud edges, haze, mirages and unusual atmospheric layers can distort ordinary lights into unfamiliar shapes.
On this page
- Haze and low cloud
- Mirage like distortions
- Weather clues investigators use
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Introduction
Clouds, mirages and atmospheric distortion can turn ordinary lights, aircraft, stars, planets and landscapes into convincing UFO reports. The object may be real, but the atmosphere changes how it looks: haze spreads a point of light into a glow, low cloud hides shape and distance, moving cloud edges create false motion, and temperature layers bend light so that distant objects appear stretched, lifted, doubled or displaced. This matters because many IFOs are not “nothing there” cases. They are real observations made through a visually unreliable medium. Project Blue Book explicitly noted that planets seen through haze, light fog, moving clouds or other obscurations had been reported as UFOs, and that stellar mirages were also a source of reports. [whs]esd.whs.milEnterprise Services DashboardEnterprise Services Dashboard
Atmospheric explanations are strongest when they fit the whole setting: weather, viewing angle, horizon position, cloud type, visibility, wind, temperature structure, and whether the supposed object changes with the sky around it. They are weakest when investigators use “weather” as a vague dismissal without matching the sighting to a specific mechanism.
Haze and low cloud make familiar lights look unfamiliar
A bright light in clear air is usually easy to place. A bright light in haze, fog, smoke, thin cloud or humid air can become a different visual problem. Small droplets and particles scatter light, softening edges and making a point source look larger than it is. At night this can turn aircraft landing lights, planets, stars, searchlights, tower lights or ground lights into glowing blobs with no obvious outline or distance cue.
Aviation guidance is useful here because pilots are trained to notice the same visual traps that affect UFO witnesses. The FAA’s Airplane Flying Handbook warns that clouds and visibility restrictions are hard to see at night, especially on dark nights or under overcast, and that lights can gradually disappear or acquire a halo-like glow when fog is present. It also notes that horizontal visibility through clouds, smoke or haze can be much worse than visibility looking down through the same layer from above. [Federal Aviation Administration]faa.gov12 afh ch1112 afh ch11
For UFO reports, the key point is not simply “haze reduces visibility”. It changes interpretation. A witness may report a large luminous object because the light has bloomed in moisture. They may report a silent hovering craft because the actual aircraft is far away, hidden by cloud, or flying almost directly towards the observer. They may report shape-changing because broken cloud repeatedly masks and reveals parts of the light.
Low cloud can also create silhouettes and false edges. A bright Moon behind patchy cloud, aircraft lights seen through a ragged cloud base, or a beam reflected off low cloud can appear as a diffuse disc, cigar, triangle or “windowed” structure. The edge of the cloud becomes part of the perceived object. When the cloud moves, the apparent object may seem to rotate, pulse, divide or accelerate even when the source light is steady.
This is why investigators look for the relationship between the “object” and the weather layer. If the object dims when cloud thickens, brightens through gaps, shares the drift of nearby cloud, or lacks any stable solid outline, haze and low cloud become more plausible. If independent witnesses at different locations see different shapes in the same patch of sky, that also points towards a light being filtered through local atmospheric structure rather than a solid object with a fixed form.
Lenticular clouds are the classic “flying saucer” weather trap
The most visually famous cloud-based IFO is the lenticular cloud. These smooth, lens-like clouds can look artificial because they have clean curves, layered rims and a stationary appearance. The UK Met Office describes lenticular clouds as strange, unnatural-looking clouds that sometimes form downwind of hills or mountains, noting that they resemble the traditional flying saucer shape and are believed to be one of the common explanations for UFO sightings worldwide. [Met Office]weather.metoffice.gov.ukMet Office Unusual cloud formationsMet Office Unusual cloud formations
Their mechanism is straightforward but visually deceptive. When stable air flows over a mountain range or high ground, it can set up standing waves downstream, like ripples in a river after water passes an obstruction. If there is enough moisture, air rising in the wave cools and condenses, forming the cloud; where the air sinks again, the cloud evaporates. The cloud can therefore appear to hover even though air is continually flowing through it. [Met Office]weather.metoffice.gov.ukMet Office Unusual cloud formationsMet Office Unusual cloud formations
That hovering quality is the source of many reports. A witness may see a smooth, bright, saucer-shaped form that remains fixed relative to the landscape while other clouds move. At sunrise or sunset, the cloud may be lit from below or from the side, taking on metallic, orange, pink or pearly tones. If several lenticular layers stack above one another, the result can look like a structured craft with decks or rims.
The weather clue is terrain and wind. Lenticular clouds are most likely near hills, mountains, ridges or other features that produce wave flow. The Met Office notes that they are visible signs of mountain waves, that those waves may extend beyond the visible clouds, and that pilots often avoid flying near them because of associated turbulence. [Met Office]weather.metoffice.gov.ukMet Office Unusual cloud formationsMet Office Unusual cloud formations NOAA’s National Weather Service similarly describes lenticular clouds as smooth, saucer-like formations produced when strong winds blow over and around rough terrain, and notes that people have mistaken them for UFOs because of that shape. [National Weather Service]weather.govSource details in endnotes.
Lenticular clouds do not explain reports of small points of light darting across the sky, close encounters, radar tracks or objects seen below a low cloud base. They do explain a narrower but important class of sightings: large, smooth, stationary or slow-changing “craft” near mountainous terrain, especially around dawn, dusk or rapidly changing weather.
Mirage-like distortions bend where things appear to be
A mirage is not just a desert puddle illusion. It is a general optical effect caused by atmospheric refraction: light bends as it passes through layers of air with different density, often because the layers have different temperatures. In a UFO context, mirages matter because they can shift, stretch, duplicate or lift the apparent position of a real distant object.
The World Meteorological Organization’s International Cloud Atlas describes a mirage as an atmospheric optical phenomenon caused by refraction, with inferior mirages displacing a distant object below its true position. [International Cloud Atlas]cloudatlas.wmo.intSource details in endnotes. Superior mirages work the other way: under a temperature inversion, colder air lies below warmer air, light rays bend downwards, and the image can appear above the true object. SKYbrary, an aviation safety resource, notes that superior mirages can make objects below the horizon visible, make objects appear bigger, closer or suspended in air, and produce upright, inverted or mixed distorted images. [Skybrary]skybrary.aeroFata Morgana | SKYbrary Aviation SafetyFata Morgana | SKYbrary Aviation Safety
This is directly relevant to horizon UFO reports. A ship, coastline, island, aircraft, vehicle lights or astronomical object near the horizon can appear in the wrong place or in the wrong shape. A distant light may seem to hover above the sea. A line of lights may appear separated from the ground. A real object below the normal horizon may be optically lifted into view. In more complex cases, a Fata Morgana can stack upright and inverted images, with compressed and stretched zones that change quickly. [Skybrary]skybrary.aeroOpen source on skybrary.aero.
The mechanism also explains why some atmospheric UFO reports feel so uncanny. The witness is not imagining the light. The light is arriving from a real source, but along a bent path. Human vision assumes light travels in straight lines, so the brain places the object along the apparent line of sight rather than at its true position. The result can look like something floating, hovering or standing above the horizon.
Mirage explanations need caution. They are not a magic answer for every strange light. A strong mirage usually requires a low viewing angle and a suitable temperature structure, often over water, ice, hot ground or a sharp inversion. It is more plausible for objects near the horizon than for objects high overhead. It is stronger when weather data, surface temperatures, sea state, inversion reports, or similar mirage observations from the same area support it.
Twinkling, colour flashes and “moving stars”
Some reports begin with a bright point of light that seems to flash red, green, blue or white, wobble in place, or drift slightly. This can happen when stars or planets are low in the sky and their light passes through a long, turbulent path through the atmosphere. NASA explains that stars twinkle because moving air slightly bends starlight on its way to the ground, causing brightness changes, and that stars near the horizon twinkle more because there is more atmosphere between the observer and the star. [StarChild]starchild.gsfc.nasa.govStar Child Why do stars twinkle?Star Child Why do stars twinkle?
For UFO reports, the most important effect is that a steady astronomical source can appear active. Near the horizon, atmospheric turbulence and refraction can make a star or planet brighten, dim, change colour, smear, jump or seem to move. If the observer has no foreground reference, small involuntary eye movements can add to the impression of motion. A camera zoomed in on the source can make the effect look even stranger, because autofocus, digital zoom, exposure shifts and sensor noise enlarge the distorted point into a pulsing disc.
Project Blue Book singled out Venus, Jupiter and Mars as planets that had been reported as UFOs when seen through haze, light fog, moving clouds or unusual conditions. [whs]esd.whs.milEnterprise Services DashboardEnterprise Services Dashboard Enterprise Services Dashboard This is not because witnesses cannot recognise planets under normal conditions. It is because an unusually bright planet low in a murky sky can lose the simple context that makes it recognisable. It may appear too bright, too colourful, too low, or too “responsive” to be a normal celestial object.
The check is usually simple: record the exact time, direction and elevation, then compare it with a sky chart. If the light remains fixed relative to the stars, sets with the sky, or appears night after night in the same celestial position, an astronomical source plus atmospheric distortion becomes far more likely than a structured craft.
Weather clues investigators use
Atmospheric IFO analysis works best when it treats the sky as a scene, not just as a backdrop. The question is not “was there weather?” but “what exact optical mechanism could this weather produce?”
Useful clues include:
- Visibility and obscuration. Fog, mist, haze, smoke, drizzle and dust can enlarge lights, hide outlines and remove distance cues. Aviation weather reporting treats these as operationally important because they affect what pilots can see and how they judge the horizon. [Federal Aviation Administration]faa.gov12 afh ch1112 afh ch11
- Cloud base and cloud type. Low cloud can hide aircraft bodies while leaving lights visible, or reflect beams and city glow. Lenticular clouds point towards mountain-wave conditions and can mimic smooth hovering saucers. [Met Office]weather.metoffice.gov.ukMet Office Unusual cloud formationsMet Office Unusual cloud formations
- Horizon angle. Mirages and strong scintillation are most relevant near the horizon, where light travels through more atmosphere and temperature layering can bend the apparent path.
- Temperature inversions. Inversions can trap haze and pollutants, form fog or low cloud, and produce superior mirages. The FAA’s pilot guidance notes that high relative humidity in an inversion can contribute to clouds, fog, haze or smoke and diminished visibility. [NTSB Data]data.ntsb.govData Pilot's Handbook of Aeronautical KnowledgeData Pilot's Handbook of Aeronautical Knowledge
- Terrain and water. Mountains, ridges, cold seas, hot roads, deserts, lakes and ice fields are all settings where strong temperature or airflow gradients can produce unusual optical effects.
- Time of day. Dawn and dusk are especially productive for false impressions because low sunlight can illuminate high cloud from below, make contrails or cloud edges glow, and leave the ground dark enough to remove scale references.
- Multiple viewpoints. If observers separated by distance report different shapes, or if only those looking through one local cloud bank see the object, an atmospheric explanation gains strength.
Modern UAP analysis increasingly emphasises this kind of contextual data. NASA’s independent UAP study argued that Earth-observing assets can help determine the local atmospheric and environmental conditions coincident with reported UAP, while also warning that many existing reports lack the sensor metadata and baseline data needed for firm conclusions. [NASA Science]science.nasa.govSource details in endnotes. That point applies directly to cloud and mirage cases: without time, direction, elevation, weather, camera settings and comparison data, a strange-looking light may remain unresolved even when a natural mechanism is plausible.
Why atmospheric explanations can be both convincing and incomplete
Weather-based explanations are sometimes unpopular because they can sound dismissive: “it was just a cloud” or “just a mirage”. That wording understates the problem. Atmospheric optics can produce genuinely dramatic appearances. A lenticular cloud can look engineered. A superior mirage can lift a real object into an impossible-looking position. A star low in the sky can flash colours and appear to dance. A light behind fog can become a glowing disc with no visible source.
At the same time, a good investigation should not use atmosphere as a vague catch-all. The explanation should match the reported geometry, duration, motion, colour, weather and location. A lenticular cloud explanation should account for terrain and wind. A mirage explanation should account for a low viewing angle and temperature layering. A haze explanation should explain why the object looked diffuse, why distance was hard to judge, or why other lights in the scene behaved similarly.
The strongest lesson is that the atmosphere is an active optical system. It can mask, magnify, colour, bend, split and animate ordinary sources. For the IFO branch of UFO reports, clouds, mirages and atmospheric distortion occupy an important middle ground: they show how a sincere witness can see something real, unusual and memorable, while the cause remains ordinary once the weather and viewing conditions are reconstructed.
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AMS Weather Book
First published 2013. Subjects: Geography, Life sciences, Earth Sciences, Atmospheric Sciences, Popular Science in Nature and Environment.
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Endnotes
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Title: Enterprise Services Dashboard
Link: https://www.esd.whs.mil/Portals/54/Documents/FOID/Reading%20Room/UFOsandUAPs/proj_b1.pdf?ver=2017-05-22-113513-837 -
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Title: 12 afh ch11
Link: https://www.faa.gov/sites/faa.gov/files/regulations_policies/handbooks_manuals/aviation/airplane_handbook/12_afh_ch11.pdf -
Source: weather.gov
Link: https://www.weather.gov/hfo/lenticular -
Source: skybrary.aero
Title: Fata Morgana | SKYbrary Aviation Safety
Link: https://skybrary.aero/articles/fata-morgana -
Source: starchild.gsfc.nasa.gov
Title: Star Child Why do stars twinkle?
Link: https://starchild.gsfc.nasa.gov/docs/StarChild/questions/question26.html -
Source: faa.gov
Link: https://www.faa.gov/air_traffic/publications/ATpubs/AIM_html/chap7_section_1.html -
Source: data.ntsb.gov
Title: Data Pilot’s Handbook of Aeronautical Knowledge
Link: https://data.ntsb.gov/Docket/Document/docBLOB?FileExtension=.PDF&FileName=FAA+Pilot%27s+Handbook+of+Aeronautical+Knowledge-Master.PDF&ID=40398161 -
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Source: weather.gov
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Title: FAA H 8083 28A FAA Web
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Link: https://skybrary.aero/articles/fog -
Source: nesdis.noaa.gov
Title: types of clouds
Link: https://www.nesdis.noaa.gov/about/k-12-education/atmosphere/types-of-clouds -
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Title: noaa 18895 DS1
Link: https://repository.library.noaa.gov/view/noaa/18895/noaa_18895_DS1.pdf -
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Title: Met Office Unusual cloud formations
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Title: Project Blue Book
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Link: https://en.wikipedia.org/wiki/Twinkling -
Source: metoffice.gov.uk
Title: whats the difference between mist fog and haze
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Title: met office ufo shaped clouds 32355770
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Additional References
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Source: aviationweather.gov
Link: https://aviationweather.gov/help/data/ -
Source: youtube.com
Title: The Science of Optical Illusions in the Sky
Link: https://www.youtube.com/watch?v=9_i1tN063-ISource snippet
Why Stars Twinkle and Planets Don't (Atmospheric Distortion)...
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Source: facebook.com
Link: https://www.facebook.com/DiscoveryChannelIndiaOfficial/posts/a-conspiracy-theory-we-have-could-these-be-ufos-disguised-as-clouds-to-fool-huma/4966295620096980/ -
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Source: primitiveproton.com
Link: https://primitiveproton.com/atmospheric-scintillation-why-stars-twinkle-and-planets-dont/ -
Source: facebook.com
Link: https://www.facebook.com/groups/AstronomyNo1/posts/5192188810826159/ -
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Link: https://www.facebook.com/KDRV12/posts/check-out-the-flying-saucer-above-mount-shasta-this-afternoon-captured-on-our-ne/1532716598860595/ -
Source: facebook.com
Link: https://www.facebook.com/HiddenFactsss/posts/disc-shaped-ufo-seen-floating-above-a-us-town-with-fiery-lights-circling-its-edg/1664336935692939/ -
Source: etlaviation.com
Link: https://www.etlaviation.com/wp-content/uploads/_resources/FAA_Aviation_Weather_for_Pilots_and_Flight_Operations_Personnel_AC_00_6A_1975.pdf -
Source: [geipan]({{ ‘geipan/’ | relative_url }}). fr
Link: https://www.geipan.fr/en/faq-page
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