His name is actually written with only the consonants YHWH.
In the Hebrew writing the vowels are, if at all written, marked with diacritics (additional signs), which is never or only rarely done with YHWH. The reason may be that according to old tradition his name should not be pronounced. One therefore talks about him in indirect ways, such as Adonay = “the Lord”.
For this reason the vowel signs for ADNY are used also for YHWH.
This would actually lead to Yahowah, but it became Yehowah. Why is that? One reason for the “e” could be that Yehu is an alternative name for him (and apparently one that may be pronounced).
The more proper pronunciation will, however, be Yahweh. Ancient text and inscription discoveries  show that the archaic Hebrew religion knew a highest god ’El ’Elyon (the sign ’ is in transliterations used for the Hebrew letter ’aleph and ‘ for the letter ‘ayin), who had 70 sons. One of his sons was Yahweh, who had a consort ’Asherah, i.e., a goddess. Her name is mentioned some 40 times in the Old Testament but it is almost always translated as “grove” or “tree”.
This is because her symbol is a tree or and upright wooden pole. So when the Old Testament states that it is forbidden to plant a tree at the altar of Yahweh it really means that it is forbidden to place a symbol of ’Asherah there (Deut 16:21 – and what sense would it otherwise have to forbid planting a tree there?).
Has Yahweh even rejected her?
The true creator god, the prime creator, was therefore not Yahweh, but ’El ’Elyon. He has obviously created a number of secondary gods as his “sons” – better: deities – of which Yahweh is one (and, of course, also the “daughter” ’Asherah).
Hence, Yahweh is not the prime creator he wants us to believe that he would be, even though he has also produced certain creations. We recognize a noticeable parallel to the Sumerian creation story Enûma Elish (I here simply use the notation “Sumerian” generally without dividing texts up in a more exact ethnological manner as “Sumerian”, “Acadian”, “Assyrian”, etc.).
This tells us about a prime creator pair Apsû and Ti’âmat (who we, in a way, could also regard as the male and female side of the prime creator, resp.), who created a number of deities, from which further deity races arose. One such deity race is the one of the Anunnaki (so called because their ruler and leader has the name Anu).
They separated themselves off from the 2 prime creators and wanted to live and act without them. Enûma Elish tells about a murder of the highest gods. The Anunnaki are told to have killed first Apsû and then Ti’âmat!
Is it possible to kill the prime creators? Of course not!
This merely symbolizes that they turned away from them and didn’t want to have anything to do with them, as if they were dead – that was the fall, the plunge out of the divine light into a relative darkness. Therefore, the Anunnaki are fallen deities. The one who is said to have murdered Ti’âmat is Marduk who also became the lord of the Earth.
The Anunnaki have under his rule created new human beings on our Earth by means of genetic manipulation, and from them to-day’s humanity arose.