You wouldn’t really see the mushroom cloud, because the shock wave would hit you first and likely kill you. If you’re in the blast zone itself then you’re likely vaporized. And if you’re out of range for the shock wave to be fatal, the flash still probably blinded you…

I think it’s safe to say, you won’t be faced with any situation where you “see a mushroom cloud”

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

You’ll see the bright flash first, at which point you can’t waste time and need to take cover from the coming blast. Which probably includes hurling up with your eyes closed. If you somehow survive the blast you can’t waste time looking at the cloud and need to find shelter from the fallout within 15 minutes. During this time, if you spot the cloud, you’ll probably be speechless and too busy.

I’m gonna parry it

Duck! … And Cover!

https://youtube.com/watch?v=IKqXu-5jw60

If your brain has enough time to process actually seeing a mushroom cloud, well, that means you were far enough away from the blast that you were not evaporated or otherwise fucked up by the initial explosion.

Otherwise, you would have felt or been destroyed by that first, before the mushroom cloud have even formed, before you could have possibly seen it.

So, if you are able to see a mushroom cloud, before you hear or feel a nuclear explosion, that means that you may actually have moments to scramble to find cover, and that may actually protect you from the blast/pressure/heat wave that has not hit you yet, as well as the immense, sucking/updraft winds that will be created by… essentially the hole that a nuclear explosion punches in the atmosphere.

Also, “fun fact”, you wanna know something reported by soldiers at nuclear tests and the Japanese at Hiroshima and Nagasaki?

When the bomb goes off, … even if you close your eyes, look away from the blast… you can still see your own bones, if you’re holding your hands/arms to shield your eyes.

There is so much radiation flying around that you get momentary xray vision.

https://inews.co.uk/inews-lifestyle/nuclear-bomb-bright-bones-fingers-atomic-veterans-2-1930293

“We were told to put on long trousers and a long-sleeved shirt,” he says, “and we had these dark goggles which meant you couldn’t see your hand in front of you. Then we had to go and sit on the football pitch with our backs to the detonation, because if we’d faced it, the fireball would have burned our eyes.

“When the bomb went off, it was so bright that I could see the spine and ribs of the guy sitting a metre in front of me, like an X-ray. I put my hands over my eyes and could see the bones in my fingers, and could see the blood pumping around my hands. It was 4am but the sky turned blue, like it was daytime. The blast was like the sound of a pistol, except 1,000 times louder. After the fireball, a couple of minutes later, you feel the blast and a strong gust of very hot wind – if you had no shirt on it feels like it would burn through your back – then once the fireball starts to dissipate you get the mushroom cloud.”

That’s just one recollection I can find via quick websearch, but there are numerous accounts of this ‘momentary xray vision’ effect happening, UK, US soldiers, Japanese, etc.

EDIT

The … HL2 Mod -> 10+ years of development -> Indie Game G STRING arguably does a fairly decent portrayal of experiencing the effects of a nuclear detonation, in sequence.

It just does a screen flash bang instead of the whole x ray vision thing, but the order of events is roughly correct.

Flash, white out, people screaming from both being irradiated and the shock, gigantic visible second sun …

… lull of time where power transformers are heard exploding due to the EMP …

… massive pressure/blast/heat front hits, random shit is thrown away from the blast, more people screaming as they are now being incinerated …

… then the wind direction changes and random shit is now sucked toward the explosion, which by now has more or less assumed the form of a proper mushroom cloud.

Uh, I guess potential [Content Warning], this may or may not qualify as nightmare fuel.

https://youtube.com/watch?v=X8suBOMnGFQ

I think the scene has been tweaked a bit in the current game since this 4 year old video, but uh yeah.

Spores!

“Mm mm! Nothing says ‘we’re fucked’ like… that (points at the cloud)”. I grab my Game Boy Advance SP and run to the shelter next doors.

Oh here we fucking go

Shit…

“Look everyone! A mushroom cloud!”

“Oh, shitsnacks!”

I was walking along a scenic trail in my city a few years ago. This particular spot had a spectacular eastern view, so I stopped to take in the last of what seemed to be a spectacular sunset.

It took my moronic ass about 15 seconds to remember that the sun usually sets in the west. So what was that red orange glow on the horizon?

A wildfire? No, I’d have heard about that.

Must be a… Nuke? What else would make that much light that fast. It had blown and I was seeing the burning destruction in its wake.

I spent the next minute or so basically shitting myself. Trying to figure out which way the fallout would blow. Thinking about all the emergency drinking water and food I never stocked. Thinking how horrific a death radiation sickness would be.

I was straight up having a panic attack!

Well then the most glorious blood moon I ever seen came up over the horizon. Huge and glowing orange.

I learned a bit about myself that day. Mostly that I am unlikely to thrive in any sort of apocalypse type situation. And that I’m a moron. Moon was cool though!

I’ll say the stupidest swear word I could imagine. Something like “Krankenscheisse”

For context, my apartment is within the blast zone of both the EU and the NATO headquarters… if I see a mushroom cloud I’m assuming for the worst, if it’s not directly on top of my head in the first place