The faster turn progression, due to the poor weather, means there is now a 10% probability the turn will end.
Is it likely? No. But 10% is not trivial.
More significantly, the Axis have a base 20% chance of ending the turn on their impulse, and each Axis major power that passes (because there are only two of them) increases the probability by 10%. (See note below.)
Do the Allies want to take the chance that the turn won't end before invading France? I don't think so.
Note: If all major powers on a side pass during their impulse, the turn can end on a 20% higher probability than the base probability - as long as a die roll can end the turn. If all major powers on a side but one pass during their impulse, the turn can end on a 10% higher probability than base.
(In the attached picture, you'll see the impulse track shows the die roll to end the turn. Passing can only help when the entry is something other than "NA".)
