Mass obscure patterns in redding leading to cloudy skies.

Trailspotter

Senior Member.
Those double dogleg trails are a good match for routes into SFO
Moreover, those double dogleg trails are a very good match to the flight tracks of UAE225 and UAL900. I got both in KML format from Flightaware and displayed them together with previously downloaded KMZ file with Terra satellite image. The corresponding turns in the tracks and the trails are connected with dashed arrows representing the direction of wind. Interestingly, the flight altitudes differed by 2000 ft, UAE225 was at 39,000 ft and UAL900 at 41,000 ft, that may explain the differences in wind directions and speeds. The two flights passed over Redding within two minutes, UAE225 at 19:10 UTC (12:10 PDT) and UAL900 at 19:12 UTC (12:12 PDT):
View attachment 12794
View attachment 12792
The estimated wind speed at 39,000 ft was about twice the forecasted at 250 hPa, so the actual time of the OP photo is near 12:10 PDT. I also looked at the flight tracks from the ground from the actual viewpoint - the UAE225 track matches the curved contrail best. The photo probably was taken before or at the beginning of UAL900 turn, its trail probably was obscured by the cloud:
image.jpg

The KMZ file with trails and tracks comparison is attached.
 

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  • Redding contrails.kmz
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Trailblazer

Moderator
Staff member
Moreover, those double dogleg trails are a very good match to the flight tracks of UAE225 and UAL900. I got both in KML format from Flightaware and displayed them together with previously downloaded KMZ file with Terra satellite image. The corresponding turns in the tracks and the trails are connected with dashed arrows representing the direction of wind. Interestingly, the flight altitudes differed by 2000 ft, UAE225 was at 39,000 ft and UAL900 at 41,000 ft, that may explain the differences in wind directions and speeds. The two flights passed over Redding within two minutes, UAE225 at 19:10 UTC (12:10 PDT) and UAL900 at 19:12 UTC (12:12 PDT):
View attachment 12794
View attachment 12792
The estimated wind speed at 39,000 ft was about twice the forecasted at 250 hPa, so the actual time of the OP photo is near 12:10 PDT. I also looked at the flight tracks from the ground from the actual viewpoint - the UAE225 track matches the curved contrail best. The photo probably was taken before or at the beginning of UAL900 turn, its trail probably was obscured by the cloud:
View attachment 12795

The KMZ file with trails and tracks comparison is attached.
Nicely done. I initially thought it might have been UAL900 but that was only from eyeballing FR24 rather than doing any fancy analysis.
 

Steve Funk

Senior Member.
The weather fit the pattern one often sees following heavy contrails. There was rain in Mount Shasta starting about 11 pm sunday, with thunder late at night and more rain.
 

Trailspotter

Senior Member.
Nicely done. I initially thought it might have been UAL900 but that was only from eyeballing FR24 rather than doing any fancy analysis.
Well, it appears that I messed up this identification of double dogleg contrails. There was a third flight, DLH454, with a similarly shaped track, that matches one of the dogleg trails. Like UAE225, it was an A380 flying at the same altitude, 39,000 ft. What I initially though was UAE225 contrail is the most likely DLH454 contrail, whereas the UAE225 contrail is the one initially proposed for UAL900. It appears that UAL900 flying higher at 41,000 ft left no long trail after all. I forgot to take into account that the distance between the flight's track and its contrail is shorter at the end that is closer to the destination. The DLH454 and UAE225 dogleg trails were formed at the same time and moved away in the same direction with the same speed. Here are the tracks of these flights and yet another A380 ARF84. Highlighted parts are from 19:04 till 19:30 UTC:
Redding_A380_contrails.jpg
The long leg of AFR84 flight track is almost aligned with its contrail suggesting the wind direction at its altitude (38,000 ft). There is a slight difference between this direction and the the wind directions for the two other, slightly higher contrails.
This revision supports the identification of curved trail in the OP photo being from UAE225. It also suggests that in #66 I've matched this photo to a wrong contrail, from DLH454. The newly identified UAE225 contrail also matches the OP photo. There are several linear contrails crossing it, which match the crossing trails in the OP and additional photos. Unfortunately, in the satellite image, these crossing trails are rather weak for making an analogous image to #66.

A revised KMZ file with DLH454 and AFR84 flight tracks is attached.
 

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  • Redding A380 contrails.kmz
    2.3 MB · Views: 327
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