The following panoramic time lapse video shows the sky over Fairfax County, Virginia USA during the afternoon of 27 February 2026. The sky is most mostly clear except for a few low level cumuliform clouds.
The video was recorded using my GoPro HERO4 Black action camera mounted on an inexpensive "Orbit" two-hour mechanical hose watering timer. The camera was set for "Video" mode / "Time Lapse Video" submode at a resolution of 4K and an interval of two (2) seconds. Approximately 26 minutes of actual recording time resulted in 26 seconds of "raw" time lapse video, given the recording settings I used.
27 February 2026.
"Sky Condition" - cloud amount and height
The following graphic shows an excerpt from the table of three-day weather observations for KDCA on 27 February 2026 nearest the time when I recorded the time lapse video (shown above). The columns labeled "Weather" and "Sky Cond." are highlighted by a red rectangle.
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| Source Credit: KDCA | National Weather Service. |
On 27 February, the "Sky Condition" was reported as "FEW030" and "FEW040" for the two times shown in the table of observations for KDCA, meaning the cloud amount was "FEW" (1/8 to 2/8 of sky coverage) and the cloud height was "3,000" to "4,000" feet. These low level clouds are fair weather cumulus (Cu).
A well defined aircraft condensation trail (contrail) is also visible beginning at the 18 s mark and continuing until near the end of the video. The contrail is much higher than the cumulus clouds.
Average air pressure at sea level is 1013.25 millibars (hPa), or 29.92 inches of mercury (inHg). Cloud formation was suppressed by the relatively high air pressures of 1019.0 and 1018.4 millibars observed at KDCA on 27 February 2026. Hence the mostly clear skies at the time I recorded my video.
Tech Tips
Notice the "lens flare" that appears from the 26 second mark to the end of video. This was caused as the camera rotated counterclockwise toward the Sun in the sky. Please comment on this blog post if you can suggest how to avoid lens flare.
The Backstory
You might be wondering why I went to the roof to capture a SkyLapse© on a nearly cloudless day. Well, I was so eager to field test a new configuration of my "Orbit" panoramic rig that I decided to go despite a less than interesting cloudscape. When I got outside I realized the field test would be a waste of time so I reconfigured the rig slightly and shot a simpler panoramic time lapse than the one I had planned. What was I planning? That will be the subject of a future blog post, to be published whenever the sky cooperates. Please stay tuned.
Related Resources
- Cloud identification - a blog post by Walter Sanford
- Clockwise "Orbit" - another blog post by Walter Sanford
- Post update: Minor modifications of "Orbit" panoramic time lapse rig - yet another blog post by Walter Sanford
Copyright © 2026 by Walter Sanford. All rights reserved.
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