Autumn Sunset is a vigorous climber that blooms repeatedly all season. Your request for one that is vigorous and repeat blooming but one you can train to a small arbor or trellis will be a tough combo to find.
If vigorous, it'll grow quickly and large and require prunng to keep it in line.
With proper care and water it will grow quite large in your growing zone. I don't spray and mine stays clean all season.

I would recommend Graham Thomas, which I see you have already thought of. In my zone 9 garden it is a moderate climber (the DA literature says it grows to 3-4 feet - don't believe it. In my climate it makes a very nice 8 foot climber, and also puts out some longer canes late in the season. It repeat blooms 10 months of the year here, & loves sun. The color (and the flowers) stays without any fading. It is a dense butter yellow, and is beautiful.

Jackie

I second Autumn Sunset.
Not a pure yellow but a blend.
One fantastic Rose that matures quickly and it's very fragrant to boot.
I don't spray and it's clean all Summer long.

the DA literature says it grows to 3-4 feet - don't believe it. In my climate it makes a very nice 8 foot climber

I believe I've seen Graham Thomas make a very small 5-6 feet climber even up here north of Boston (& then die back to almost nothing during a particularly harsh winter).

milieu serene, are you familiar with the Climbing Tea (vs. "Hybrid Tea") & Noisette roses? They are older roses that often, but not always, have a more relaxed flower form, yet they also often have the advantage of being bred from wild roses that naturally grow in a climate not unlike yours. In fact, the first Noisette rose came from a South Carolina plantation, back in the early 19th Century (or late 18th). They are all dependable rebloomers, even in hot summers, and it's not unusual for them to suffer little from diseases when grown in warm/hot, humid climates (the advantage of being bred from wild roses of the semi-tropics).

If you aren't familiar with them, I encourage you to also take this question of yours over to the Antique Rose Forum. There you're bound to get good answers from other rosarians in the Southeast who can give you good recommendations about yellow Tea & Noisette roses that will handle your climate well. (Oh, and yes, a good number of the Noisette & Tea roses are varying shades of yellow, or yellow with pink &/or orange.)

(The more relaxed flower form of the Teas & Noisettes is akin to what David Austin was going for when he bred his English roses. In your climate you can find "old roses" that do it naturally and have always done it. What Austin was trying to do was create a set of roses that looked like the old ones, including the old ones of Northern Europe that only bloom in June, but bloomed all through the summer like Hybrid Teas & Floribundas, even in the colder climates.

In the Southeast where you live you have access to a whole raft of beautiful reblooming climbing roses I can't grow because they won't tolerate my cold climate, but they'll love yours!)

York_Rose, thank you so much for that information. I am not at all familiar with the Climbing Teas or Noisettes. They do sound like just what I would be looking for.

I will follow your advice and post my request in the Antique Rose Forum.

I planted a new yellow lare flowered climber this spring and it has been terrific.
I got "Roberta Bondar" from Palatine roses so of course the new bareroot was absolutely in perfect condition as were the other two climbers I got--Harlekin and Salita--which are both very nice as well.
All three of my climbers are right at 10' tall this first year.
Roberta Bondar blooms large buttery yellow flowers with a nice licorice type fragrance. The blooms last a long time and are very pretty to look at. The bush is very healthy and so far has not shown any sign of BS or PM.
All in all, if you're looking for a good large flowered yellow climber, "Roberta Bondar" from Palatine Roses in Canada cannot be beat.
John

There are many tea-noisettes that are yellow. One of my favorites is Reve d'Or:
http://www.helpmefind.com/rose/pl.php?n=5197
Other popular ones are Crepuscule:
http://www.helpmefind.com/rose/pl.php?n=1366
William Allen Richardson:
http://www.helpmefind.com/rose/pl.php?n=6578
and Jaune Desprez:
http://www.helpmefind.com/rose/pl.php?n=3472

Good luck. Any of these should meet your needs and your mother's. These roses need little water once established, are healthy- no need to spray, and can take summer heat, tho' they may not bloom during the hot part of summer, especially the first few years.

Jill