Jeg må bytte til vinterdekk før snøstormen kommer.

Må means must / have to, so it expresses necessity or obligation.

• Jeg må bytte til vinterdekk = I have to switch to winter tires
• Jeg skal bytte til vinterdekk = I am going to / I will switch to winter tires
  This sounds more like a plan or intention.
• Jeg vil bytte til vinterdekk = I want to switch to winter tires

So må is the natural choice if the speaker needs to do it, especially because of the coming snowstorm.

Bytte means change / switch / replace, and til often shows what you are changing to.

So:

• bytte dekk = change the tires
• bytte til vinterdekk = switch to winter tires

In this sentence, til is important because it tells you the new type of tires being chosen.

Because Norwegian often leaves out the article when talking about something in a general category after verbs like bytte til.

So bytte til vinterdekk means switch to winter tires, not switch to the winter tires.

Compare:

• Jeg må bytte til vinterdekk. = I need to switch to winter tires.
• Jeg må bytte til de vinterdekkene. = I need to switch to those winter tires.

The sentence is talking about the type of tire, not a specific set already identified.

It is understood as plural in meaning: winter tires.

The reason this may look confusing is that dekk has the same form in singular and indefinite plural:

• et dekk = a tire
• dekk = tires

Since vinterdekk is a compound noun built with dekk, the same pattern applies. In context, when someone changes tires on a car, we naturally understand it as plural.

Because Norwegian usually writes compound nouns as a single word.

So:

• vinter
  • dekk → vinterdekk
• snø
  • storm → snøstorm

This is very common in Norwegian. English often separates these or varies more, but Norwegian strongly prefers one-word compounds.

Norwegian often uses the present tense to talk about future events, especially when the future is clear from context.

So:

• snøstormen kommer literally = the snowstorm comes
• natural English meaning = the snowstorm is coming / arrives

After time words like før (before), this is especially normal. English often does something similar:

• before the storm comes
• not usually before the storm will come

So the Norwegian tense choice is very natural.

Snøstormen is the definite form: the snowstorm.

This suggests a specific snowstorm that the speaker has in mind, probably one expected soon or already mentioned in context.

• før snøstormen kommer = before the snowstorm comes
• før en snøstorm kommer = before a snowstorm comes

Both are possible, but the definite form sounds more like a particular incoming storm.

Før means before and introduces a time clause.

So the sentence has:

• main clause: Jeg må bytte til vinterdekk
• subordinate time clause: før snøstormen kommer

Together: I have to switch to winter tires before the snowstorm comes.

This is a very common structure in Norwegian.

Yes. This is normal subordinate-clause word order.

Here you have:

• før = conjunction
• snøstormen = subject
• kommer = verb

So the clause is simply before the snowstorm comes.

A useful extra point: if the før clause comes first, then the main clause has inversion:

• Før snøstormen kommer, må jeg bytte til vinterdekk.

Notice må jeg instead of jeg må. That is standard Norwegian word order.

Må is usually pronounced with a long vowel, roughly like mo in a stretched-out form, though not exactly like English mow.

A rough learner-friendly guide:

• jeg often sounds like yai or yai/yei, depending on dialect
• må sounds roughly like moh
• bytte has a short y sound, which English speakers often find difficult
• snøstormen has the ø sound, another vowel English does not really have

If pronunciation is your focus, the hardest sounds here are usually y in bytte and ø in snøstormen.

Not in the same way.

• dekk = tire
• hjul = wheel

A wheel includes more than just the tire. In everyday car-related language, if you are specifically talking about switching from summer tires to winter tires, vinterdekk is the correct word.

In some real-life situations people may talk about changing entire wheel sets, but this sentence is clearly about winter tires, so vinterdekk is the best choice.