How to Follow a Future ISS Pass Across The Atlantic Ocean.

[+8Nuts MotherGoose]

This post is to instruct you on how to find ISS Path Check Points while crossing the Ocean.
We will be following an ISS Pass from Jacksonville, Florida to Paris, France.
The Pass will be at Jacksonville at May 14, 2020, 21:45 to the SE. You can open a "Heavens Above" web page and set your location for Jacksonville, but in this case, a view from Boston, MA. will also show the Jacksonville area on the Ground Path map.
Open a "Heavens Above" web page and change your observing location for Boston, MA. Click SEARCH, scroll to the bottom of the page and click UPDATE. Now click on ISS and a list of passes show. Just above the list, click on the right arrow button. This will move you forward 10 days in time. Keep clicking the right arrow until May 14 shows in the list. There are several passes for May 14. Click on the one that is closest to time 21:49. A new page shows the night sky and where the ISS will pass through it. Above the right corner of the map, click on GROUND TRACK. Now you see a map of the Earth with the ISS Passing across it as a straight black line. A solid black line means the ISS is lit by the Sun and can be seen. The dotted line is when the ISS is in the Earths shadow and can not be seen. 
Since our goal is also to follow the track across the Ocean, and select Check Points, we will continue with that. In the upper right hand corner of the map, just below DATE is a triangular island. That is Newfoundland, which will be our next Check Point. Look at the time listed on the ISS path closest to Newfoundland and make a note of it. You will need that time later. For Newfoundland, I use the town of Grand Falls. Windsor is next to it, but I always misspell it with an E. Open a new tab for Heavens Above and select your new location as Grand Falls, Newfoundland. Move forward in time until May 14 shows on the list.
Newfoundland has a unique Time Zone. It is 1.5 hours east of Eastern Time where Boston is located. The times listed on the ISS pass line are in Eastern Time. If the time closest to Newfoundland is 21:53, you have to add 1 hour 30 minutes to get Newfoundland Time zone. which would be 23:23. Now go to the list of passes. Because this pass is currently in the Earths shadow, it will not show in the list of visible passes. Above the list you will see "Passes to include: O visible only O all." Click on All. The list gets longer. Now click on the one closest to May 14, 23:23. And then go to the Ground Track. I frequently see a 1 minute time difference between the ground track maps at this location. It is self-correcting on the next map and can be ignored.
Looking at the Ground Track map, we see faint white line running N/S and E/W. Look above at the top of the web page in the URL. we see lat=48.9277&lng=-55.6575. That's N48.9277 W55.6575. Grand Falls is just below the horizontal white line, so that white line is N50.0000. Grand Falls is west of the vertical white line, so that line is W50.0000. Both horizontal and vertical white lines are always 10° apart. Near the right side of the map, you see the ISS pass cross where two white line cross. That location is N50.0000 W40.0000 and it will be our next Check Point.
Because there is no town to use as a Check Point, we have to manually create the new Check Point.
(CHECK POINT CREATION) 
Open a new tab, go to Heavens Above, and Change your Observing Location.
Instead of entering town information in the blanks above the map, scroll to the bottom of the page under the map.
For Latitude, delete what is there and enter 50 (That's same as N50.0000.)
For Longitude, delete what is there and enter -40 (don't forget the negative sign) (That's same as W40.0000.)
No need to adjust Elevation.
For Name, Enter "Ocean N50 W40" (quotes not needed)
To show the proper time, we need to change the Time Zone.
click on the little arrow to the right, scroll down and click on (GMT-3.00) Saint Pierre & Miquelon.
Double check you entries and click on Update.
Go to the list of passes and go to the one closest to May 14, 23:55. and go to the Ground Track. The first thing you will notice is the ISS has come out of the Earths shadow and is lit again (solid line.)
The next thing to notice is the time. Although we changed Time Zones, it's only 30 minutes different from Newfoundland. That's because Newfoundland took that extra half hour.
On the right edge of the map we are seeing Ireland. We could set our next Check Point in a city there and we would not have to manually create a Check Point. BUT, if we are following an ISS path that started in Oklahoma City or farther north, the ISS would be swinging downward toward Spain or Portugal and an Ireland Check Point might miss it. So we will set a Check Point at the east edge of the current visible circle where the two white lines cross. We will call our new Check Point "Ocean N50 W20"
Follow the same instruction as above (CHECK POINT CREATION) and make the following changes:
For Latitude, delete what is there and enter 50.
For Longitude, delete what is there and enter -20 (don't forget the negative sign)
No need to adjust Elevation.
For Name, Enter "Ocean N50 W20" (quotes not needed)
For Time Zone, enter (GMT+0.00) United Kingdom, Ireland 
and hit Update.
Remember that you are now beyond Midnight and have to go to May 15 early morning to find the proper pass in the list. The easiest way is to check for a time minutes in the list that are the same as on the previous map, with only an hour or two difference due to time zone change.

 

A surprise to remember - the Check Points at Newfoundland, Ocean N50 W40, and Ocean N50 W20 can be used every time you are planning a cross-Atlantic ISS Pass. Make a note of each of those Time Zone settings.

Last year, that 10 minute shadow we saw on the path today disappeared less than 1 pass (90 minutes) before the ISS traveled it.

When planning for a future pass, remember the passes slowly move westward and the times change too. Recheck frequently (weekly.) 

[+Max and 99]

Holy cow. I think I'll figure this out on my own.

[+8Nuts MotherGoose]

1 minute ago, Max and 99 said:

Holy cow. I think I'll figure this out on my own.

This is for a new person. Much of it you already know and can slide over.

All you need to do is create the 3 Check Points - Newfoundland, Ocean N50 W40, and Ocean N50 W20

 

[+Max and 99]

Yeah! I did it. I checked my path between OKC and Spain in only a few minutes, with a few checkpoints, and confirmed that there is a solid line the entire way for the pass I chose. Woohoo!