13:27
Fireball causes a considerable explosion. In-game, this spell has a 10 feet radius (take note this is gameplay-wise, lorewise is almost certainly higher).
https://en.uesp.net/wiki/Oblivion:Destruction_Spells
Using Nukemap again for a radius of 3m and we get a yield of 0.000278 kilotons...
2:52
https://en.uesp.net/wiki/Oblivion:Destruction_Spells
The Weak Fireball spell causes a small explosion, which in terms of gameplay is 5 feet in radius (as you can see above compared with a troll). 5 feet is 1.52400m. Enter this into Nukemap and we have a yield of 0.0000506 kilotons for a...
0:54
Firestorm is the most powerful spell you can learn in Skyrim, and it causes a massive explosion. Although this is gameplay (and thus the actual lore version could be far more impressive), as an ingame spell, it has a range of 100 feet (or 30.48m).
https://en.uesp.net/wiki/Skyrim:Fire_Storm...
25:13
Enemies Explode causes some considerable explosions. At its highest (at least according to gameplay, lore is likely much higher), Enemies Explode has a radius of 20 feet (or 6.09600m).
https://en.uesp.net/wiki/Oblivion:Spells#Destruction
Let's put this through Nuke Map and play around...
1:06
Fireballs explode to do some considerable damage. I'll have to look up to see if there are any examples of how big fireballs can be in the lore, but gameplay-wise, they can reach 15 feet (or 4.57200m) in radius.
https://en.uesp.net/wiki/Skyrim:Fireball
Put this through Nuke Map and mess...
0:39
Several huge fireballs explode, seemingly from Alduin (though perhaps also mages going by the dialogue).
0:11
The average height of a Norwegian man is 179.9cm, or 1.799m (closest equivalent to a Nord I could find).
184 pixels = 1.799m
1 pixel = 1.799m/184 = 0.00977717391m...