Сегодня ветер сильный, поэтому я возьму тёплый шарф.

In Russian, the verb to be is usually omitted in the present tense.

So:

• ветер сильный = the wind is strong
• literally: wind strong

This is completely normal in Russian.
If you were talking about the past or future, a form of быть would appear:

• Вчера ветер был сильный. = Yesterday the wind was strong.
• Завтра ветер будет сильный. = Tomorrow the wind will be strong.

Because сильный is an adjective, and it describes the noun ветер.

• ветер = wind
• сильный = strong

The adjective has to agree with the noun in gender, number, and case.

Here, ветер is:

• masculine
• singular
• nominative

So the adjective is also masculine singular nominative: сильный.

By contrast, сильно is usually an adverb, meaning something like strongly or a lot:

• ветер дует сильно = the wind is blowing strongly

So in this sentence, сильный is the correct form because it describes what the wind is, not how something happens.

You usually learn the gender of a noun together with the noun itself, but the ending often gives you a clue.

ветер ends in a consonant, and nouns ending in a consonant are usually masculine.

So:

• ветер → masculine
• therefore: сильный ветер, тёплый ветер, etc.

This matters because adjectives must match the noun:

• masculine: сильный
• feminine: сильная
• neuter: сильное
• plural: сильные

Because поэтому means therefore / so / that’s why, and here it links two clauses:

• Сегодня ветер сильный
• поэтому я возьму тёплый шарф

Russian normally separates this kind of connection with a comma.

So the structure is:

[statement], therefore [result].

That is why the comma is there.

Поэтому means therefore, so, for that reason, or that’s why.

It introduces a result or consequence of what was said before.

In this sentence:

• Сегодня ветер сильный = the situation
• поэтому я возьму тёплый шарф = the result

A very natural English translation is:

• The wind is strong today, so I’ll take a warm scarf.

It is common in both speech and writing, and it is neutral in style.

Возьму is the 1st person singular future of взять, which is a perfective verb.

That means it refers to a single completed action in the future:

• я возьму шарф = I will take the scarf / I’ll take a scarf

This fits the sentence well, because the speaker is making a decision about one future action.

Compare:

• я беру шарф = I am taking / I take a scarf
  usually present tense, not the best fit here
• я буду брать шарф = I will be taking a scarf
  this sounds more process-oriented or habitual, and is less natural here
• я возьму шарф = most natural for I’ll take a warm scarf

So возьму is used because the speaker means I’ll take one with me as a completed choice/action.

It is in the accusative.

The thing is that for many masculine inanimate nouns, the accusative singular looks exactly the same as the nominative singular.

So:

• nominative: шарф
• accusative: шарф

Since шарф is masculine and inanimate, there is no visible change here.

You can still tell it is the direct object because of its role in the sentence:

• я возьму шарф = I will take a scarf

If the noun were feminine, you would see the case change more clearly:

• я возьму книгу = I will take a book

Because тёплый is an adjective meaning warm, and it must agree with шарф.

Шарф is:

• masculine
• singular
• accusative (same form as nominative because it is inanimate)

So the adjective is also masculine singular in the matching form:

• тёплый шарф = a warm scarf

Compare other genders:

• тёплая куртка = a warm jacket
• тёплое пальто = a warm coat
• тёплые перчатки = warm gloves

Here сегодня functions like an adverb of time, meaning today.

It tells you when the situation applies:

• Сегодня ветер сильный = The wind is strong today

Russian often places time words near the beginning of the sentence, but the word order can vary:

• Сегодня ветер сильный.
• Ветер сегодня сильный.

Both are possible, though the emphasis may shift slightly.

Yes. Russian word order is more flexible than English word order, because case endings help show grammatical roles.

This sentence could be rearranged in different ways, for example:

• Сегодня ветер сильный, поэтому я возьму тёплый шарф.
• Ветер сегодня сильный, поэтому я возьму тёплый шарф.
• Поэтому я возьму тёплый шарф, сегодня ветер сильный.
  grammatically possible, but less natural in this context

The original version is very natural because it presents:

1. the situation first
2. the consequence second

That is a common and clear structure in Russian.

Yes. In Russian, ё is often written as е in normal text, so you may see:

• тёплый
• теплый

They mean the same thing.

However, the pronunciation is different from plain е:

• ё is pronounced like yo in yonder or your, depending on accent approximation

So тёплый is pronounced roughly TYOP-lyy.

For learners, it is helpful to remember the ё even when texts omit it, because it helps with pronunciation and sometimes avoids confusion.

Literally, возьму means I will take.

In context, though, it often implies:

• I’ll take a warm scarf with me
• possibly also I’ll put on / bring a warm scarf, depending on the situation

Russian often uses взять where English might choose take, bring, or even something more context-specific.

If you wanted to say specifically I’ll put on a warm scarf, Russian would more likely use:

• Я надену тёплый шарф.

So in your sentence, возьму emphasizes the decision to take/bring the scarf because of the weather.