Celestia and Luna did more buying time for everyone than they have ever done before in a two-parter.

Yeah, pointing Flurry Heart at the clouds probably would’ve bought them at least an hour.

@IceKitsune  
Less “strong enough” (alicorns in raw power are stronger than it) and more “attuned”. Sorta like a hammer vs. a wrench - no matter how strong you are, if all you have is a hammer you cannot tighten a bolt. Crystal Heart is the wrench in this case.
 
Plus, you know, the whole “harmony” thing with Crystal Empire denizens, which can amplify the power of the Heart to the point of not just keeping the storm at bay but actively repelling it.

@JAK0723  
A) it heavily hinted the storm is like everfree forest, can’t truly be stopped, only sealed off (or in the empire case seperate). and b) the crystal heart is made of crystal, and it was discover sound frequency can shatter it, combine with earth pony lung on a alicorn body and wham, one shatter relic (And yes i say earth pony lungs, her horn was glowing when she started that bawling that destroy the heart, which means aspect of earth pony.)

@IceKitsune So what your saying is that the storm is like the everfree in that it can’t truly be tame and the worse a storm the powerful the storm is.

Chinese government last winter.

@JAK0723  
Well we know that baby unicorns have bursts of magic that are far stronger then that of a normal Unicorn. Flurry is a Alicorn and was already stated to be easily above a normal baby Unicorn with her bursts. Also just because a relic is powerfully enough to hold back the storm doesn’t mean it is physically very strong, it was just crystal after all.
 
Also the storm was like that of the Everfree Forest which we know magic doesn’t really effect very well and is dangerous to go into. I think it’s more like the storm is severely resistant to magic but the Crystal heart just happens to be strong enough to hold it back and effect it.

I’m unsure how this episode affects the alicorn lore. Celestia and Luna are unable to control a rogue snowstorm, but a baby alicorn can shatter an ancient powerful relic just by crying?  
Neat work on the frosty wings, though shouldn’t there be buildings around the castle?