Satellite archive: date displayed is incorrect (off by one day)
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Hello,
In the satellite archive, the images displayed for date J are actually for date J+1, for all dates. For example, if I select May 31 at 18:00 Z, the image displayed is actually for June 1 at 18:00 Z; for June 11 at 03:00 UTC, it is actually June 12 at 03:00 Z, etc. See images (left panel is from windy, right panel is from NASA WorldView. Date and time listed at the bottom of each). Can this be fixed? Thank you.
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@rene_ser Can you please share your setup on these NASA pages? I checked our data with other available source and it seems okay to me.
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Hello Ondrej,
Thank you for the follow-up.
I compared again what Windy shows in the satellite archive with the following two web sites (satellite GOES-18 in western Canada). I come again to the conclusion that the satellite imagery displayed in Windy on date J and time X is actually for date J+1 and time X.
NASA WorldView (you can select date and time): https://worldview.earthdata.nasa.gov/?v=-163.2596903805173,19.87913153912618,-45.386860803167735,76.43208837678839&z=4&ics=true&ici=5&icd=10&l=Reference_Labels_15m,Reference_Features_15m,GOES-West_ABI_Band13_Clean_Infrared&lg=true
CIRA RAMMB (you select date and time from the archived imagery option): https://rammb-slider.cira.colostate.edu/?sat=goes-18&sec=full_disk&x=14076&y=1920.2666625976562&z=3&angle=0&im=12&ts=1&st=0&et=0&speed=130&motion=loop&maps[borders]=white&p[0]=band_13&opacity[0]=1&pause=20190703152000&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&draw_color=FFD700&draw_width=6
I'm attaching three images as an example. The image from Windy on June 9 at 21:00 Z/UTC is the same as on June 10, 21:00 Z/UTC in WorldView and CIRA. I know for a fact that the date/time of the Worldview and CIRA images are correct because I looked at these in real-time on June 10.
Thank you.
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@rene_ser Can you let me know which version of Windy you have? And also from what location you access Windy? I am not able to replicate this even on the same date, with same sources and I tested VPN access from US and there are still same images on NASA and Windy.
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I access Windy From Montreal, Canada.The problem I described in windy is only for archived images. The real-time images have the correct date and time.
Here is how to replicate on the same dates: Click on the links I provided in my first message and in NASA Worldview, change date and time at the bottom left. For CIRA, click on Archived Imagery and select date/time.
Thank you.
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@rene_ser I tested it in the same browser and still the same result, can you please test it in an anonymous window or different browser?
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Thank you for the feedback. Much appreciated.
I tried with browsers Chrome and Brave on Windows 10 but no success (Windy date/time still equal to NASA/CIRA date+1/time).
I then tried with the Windy APP on my iPad. There is also a difference between Windy and NASA/CIRA, but it is only four hours with Windy image = NASA image - 4 hours. Given that my local time on iPad and computer are Eastern Daylight Time (EDT = UTC-4), I figured that the differences are likely related to local time versus UTC.
To test this, I changed the clock on my computer (Windows 10) to local time = UTC. This solves the problem! Windy and NASA/CIRA now show the same image at the same time and date. I don't know why a 4-hour difference between local time and UTC results in a 24-hour difference between the Windy archive and NASA/CIRA (that is Windy date=NASA/CIRA date+1) on my computer Windows-10.
Is there a way to adjust Windy on Windows and iPad IOS so that it shows UTC dates/times regardless of local time?
Thank you!
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I tried that on my computer Windows 10 and it doesn't change anything to the display of the satellite archive. I still get display date/time in Windy exactly 24 hours earlier than what it is in NASA and CIRA.
All adding 'display times UTC' does is that the time displayed for forecasts adds UTC time next to the local time (for example 8:00 12:00 UTC).
As mentioned yesterday, the only way I can get Windy on Windows 10 to display the same image on the same date/time as NASA/CIRA is to change the Windows 10 clock time from EDT (UTC-4) to UTC.
My question yesterday (is there a way to MODIFY THE Windy SOFTWARE on Windows and iPad IOS so that it READS UTC dates/times regardless of local time) was to see if Windy could retrieve the date/time in UTC in satellite archive without looking at the local time in Windows 10, which it seems to be doing at the moment.
Thank you.
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@rene_ser, @Ondřej-Šutera, was this ever resolved. I'm seeing the same one-day error as well when I compare archived data to screenshots previously captured live from windy.com on a given day.
