Wind is a vector quantity having both speed and direction. For purposes of comparison, statistical analysis, or computation of averages, the wind vectors have to be broken into their zonal component (east, west) and meridional component (north, south). Here, by convention, an east wind or easterly wind means one that is blowing from the east, and so on.
The Bible contains several references to the power of the wind, its variability and its destructive potential. Besides such allegorical imagery, in many places the wind is referred to in practical terms. Only the four basic directions, east, west, north and south, are talked about, and intermediate directions are rarely mentioned, like for example, the nor’easter encountered by Paul in his final voyage (Acts 27:14).
Out of the four winds of the Bible, the east wind is the one which is mentioned most often and it is generally described as a very strong, hot and dry wind. The book of Genesis (verses 41:6, 41:23, 41:27) talks of the heads of grain that sprouted and then got withered by the scorching east wind. The book of Ezekiel (verses 17:10, 19:12) tells how the strong and tall vine was uprooted and got completely withered and stripped of its fruit by the dry east wind.
The east wind of the Bible is also a fierce wind (Isaiah 27:8, Job 38:24), it can destroy ships on the high seas (Psalm 48:7, Ezekiel 27:26), it can scatter and sweep out people (Job 15:2, 27:21, Jonah 4:8, Jeremiah 18:17).
The book of Exodus describes how God brought in ten different forms of plagues over Egypt. The seventh plague was the plague of hail, and it was followed the next day by the eighth plague which was the plague of locusts (Exodus 10:13). The sequence was such that the massive hailstorms had already rendered the ground wet. The next morning God used the east wind to bring in a swarm of locusts, which found in the wet sandy soil an ideal environment to lay eggs and breed in huge numbers. Whatever had survived the hail, was completely devoured by the locusts. The following day, God changed the direction of the wind to a very strong west wind. It caught up the locusts and carried them into the Red Sea, and not a locust was left anywhere in Egypt (Exodus 10:19).
The strong and dry east wind again played a major role in the parting of the waters of the Red Sea that enabled the Israelites to cross it. God used the strong east wind to drive the sea back, turn it into dry land and divide the waters (Exodus 14:21). The sheer power of the east wind that made all this possible, was remembered for long (Psalm 78:26).
In the book of Hosea, there is a warning for any one who feeds on the wind, pursues the east wind all day, and multiplies lies and violence (12:1). An east wind from the Lord will come, blowing in from the desert; his spring will fail and his well dry up. His storehouse will be plundered of all its treasures (13:15). Hosea speaks of the fruitless deeds of evildoers in these words (8:7): They sow the wind and reap the whirlwind.