Grand or gro

Question

If one wants to say "a big storm" should it be "une grosse tempête," "une grande tempête" or is either one acceptable?

Accepted Answer

Hi Andrew, 
You would normally use the word 'grand' when associated with length or impact and 'gros' for big/ fat/ sizeable, so to describe a storm you could say both -
Il y a eu une grosse tempête hier soir = There was a big storm last night 
But to talk of an event like the storm of 1999 we use 'grand' as it was definitely 'impactful'. 
La grande tempête de 1999 = The great storm of 1999
It caused a lot of damage to the 'parc du château de Versailles',  even breaking some windows to the Palace so you would use 'grand' as it was imposing and catastrophic.
Hope this helps!