Learn German: Solange der Kontostand hoch ist, ist jede Abbuchung möglich. - As long as the account balance is high, every deduction is possible.

You would replace Solange with Sollte at the very beginning, and change the conjugated verb ist to the infinitive sein at the end of the clause: Sollte der Kontostand hoch sein, ist jede Abbuchung möglich. Note that this changes the meaning slightly from 'as long as' to 'if it should be the case that'.

Is solange considered a conditional word here?

Technically, solange (as long as) is a temporal subordinating conjunction. However, in sentences like this, it functions very much like a condition, meaning 'provided that'. Because it is a subordinating conjunction, it sends the conjugated verb (ist) to the very end of its clause.

Why does the second half of the sentence start with the verb ist?

The entire subordinate clause (Solange der Kontostand hoch ist) counts as the first position of the overall sentence. To keep the main verb in the second position (the V2 rule), the second clause must start immediately with its verb (ist), pushing the subject (jede Abbuchung) right after it.

Could you break down the financial term Abbuchung?