The blizzard has been canoncial since the 1986 reboot. To the best of my knowledge it's still canonical. It was one of Byrne's better ideas (I never had any problem with throwing out the whole orphanage bit; it's archaic).
I think this is one of the things were Kal-El being adopted formally by the Kents was more straightforward than the blizzard bit, which I have various problems with:
- A multi-month-long relentless blizzard?
- Apparently Smallville, unlike most rural communities in the midwest used to dealing with lots of snowfall, doesn't have any snowplows or experience at dealing with emergency snowstorms.
- Also apparently, the National Guard (or US govt.) didn't investigate this odd weather phenomenon and/or send help to the snowed-in people of Smallville.
- Would think the Kents would've called for help/to see if their neighbors were OK/etc. at *some* point (unless the phone lines were down)... or checked up on TV/radio to see why the heck such a snowstorm was happening.
- Still don't feel the Kents could pass off Kal-El as a newborn---even if he was just "born" when he landed on Earth, that's still 9 months of pregnancy to account for somewhere, which can't fit in (even with the multi-month-long blizzard that doesn't apparently elict concern from the National Weather Service/National Guard/etc.)... esp. since babies grow pretty fast. Would think there'd thus still be questions (even ignoring that Clark doesn't look anything like Jonathan *or* Martha)...
The adoption approach made more sense to me than the above---far as the Langs/Chief Parker/etc. would be concerned, the Kents found an abandoned infant, took him to the authorities who could look for the infant's parents, said infant was offered for adoption by the Kents (once his parents couldn't be found), and the Kents took lil' Clark home. If one feels an orphanage is archaic (which I suppose it might be---assuming Kal-El landed on Earth in the mid-70s by this point in time), substitute "Smallville County Child Services" or whatever in its place. Seems more straightforward to me (and not asking us to accept some stupid-sounding snowstorm/Smallville having incompetent blizzard-handling skills/some improbable pregnancy...).