The place I am typing this from is predicted to get yet another pile of snow and ice dumped on it this weekend, and I’m guessing most of the people who read this site are in the same situation.

There are some things to do right now to prepare for the impending Snow Event: make sure you’ve got some salt for the driveway, buy seven dozen eggs and a 55-gallon drum of milk (because, you know, you might not be able to leave the house for a whole 30 hours), and get your snowbound entertainments all lined up (The Shining is fun if you’re brave, or you could splurge on kind-of-expensive board games—Settlers of Catan is awesome if you’ve got three or four players available; I’ve heard there’s a football game on Sunday that a few people are interested in, too).

There are some things you can do while you’re stuck indoors, too, and this weekend, make changing every password you’ve got one of them.

See, there’s been another data breach, from Yahoo! this time. They say an “unspecified” number of accounts have been compromised, which probably will end up meaning all of them. Remember how the Target thing went from 40 million to 110 million? So you need to change your Yahoo! passwords, but there will be more major security breakdowns in the near future. There always are. So even if you’re not going to be stuck inside due to inclement weather this weekend, even if you don’t have a single Yahoo! account, it’s time to just change all your passwords.

Make all your passwords long, very random, don’t use real words, use numbers, upper- and lowercase letters, special characters, and do not use the same password for more than one account. Here’s a quick primer that should teach you everything you need to know about choosing a good password:

Bad Password: 123456
Bad Password: password
Bad Password: trustno1
Good Password: 6ZUNFPtjaWZPk$eAafBt8YhP
Good Password: KjV7$y!92#MqKS&YYSaW3MjtRmSPxR

Now, it’s going to be impossible to remember twenty different passwords (or even one) that look like those last two, so you’re going to have to find a way to record them, whether by carefully writing them in a notebook (that you keep in a different room than your computer), or by using a password manager like LastPass or Keeper (both of which will generate those stupid-long passwords for you). It doesn’t matter what method you use, just do it.

It’s a good idea to change passwords regularly, too. I’m even pretty bad about remembering to do it, but it’s a good idea to at least do it a few times a year. Even a super-strong password that would take a brute-force password guessing script a quadrillion years to guess might as well be “123456” as soon as some goofy company decides to keep its entire database of usernames and passwords in plain-text, unencrypted form, and somebody breaks in and gains access to it. This has happened in the past.

Stay vigilant. And warm.