Example Forecasts below were actual forecasts given. They do vary in length, sometimes there is more to say than other times.
That route today would have been occasional to continuous light to moderate possible for most of the flight, but the maps are suggesting a trend towards smoother air. I do believe it's getting smoother. It's looking like you'll be out of the SLC vicinity before weather rolls in over the mountain states, and as you make your way east, that gives time for the air to smooth out even more.
I think for your flight, fairly smooth from SLC to about the Great Lakes states and vicinity, then some occasional to continuous light to moderate through just west of JFK, hopefully smoothing out by then.
Some possible bumps out of LHR at the start, smoothing out quickly. Ocean crossing looks pretty good, a small area of light to moderate bumps as you cross a jet about 1.5 to 2 hours in, and then smooth again. Unfortunately around the area of Newfoundland and through the rest, we've been seeing some bumpy rides. I'm hoping (and the trend is towards smoother air), by the time you make your way to this area it should be smoother, but I wouldn't not be surprised if you ran into some occasional to continuous light to moderate from the area of Newfoundland through Boston.
Light bumps out of Doha due to the jet stream in the area, smoothing out nicely. Should be fairly nice through to the southern tip of India. In the area west of Malaysia, occasional light bumps, maybe a bit of moderate here and there due to widespread but light weather. West of Australia, the bumpiest part of the flight just off the coast due to a turbulent jet stream, continuing a little bit inland as well. Light to moderate over Mainland Australia due to the jet stream. You should get a bit of a break hopefully before you start to descend with light to moderate in to Sydney due to weather. Weather over Sydney peaks eight hours before landing, so hopefully it goes away in time for landing.
So, a little bit of everything, the Australian forecast isn't as smooth as we'd like but I think plenty of room for at least a large part of the flight to be good.
How accurate is this? I look at weather conditions and several different turbulence charts, all of which usually disagree with each other, and I try to summarize the possibilities of what can happen for your specific flight. Rather than predicting exactly what happens, I instead tell you what could happen and the probability of that happening. Sometimes I find that people have already self forecasted and they just want some reassurance or just to talk about the flight, and you get some of that too.
What's your refund policy? No questions asked, I will refund your money, just ask! If I make a mistake and miss your forecast I automatically refund your forecast.
Note, I don't outsource these. I write each and every one, and wrote over 1,700 forecasts in 2017. I've been forecasting turbulence since 2005 when I created this site.
Be sure to check your spam folder for your forecast, they have been going there a lot lately and I don't want you to miss your forecast.
Sounds good, I want a forecast!
Actual testimonial: Thanks for your help!! It is better than therapy. 👍 (from a satisfied customer)