Exodus 10:13

13. An east wind All travellers relate that the wind brings the locusts, but an east wind would have brought them from Arabia across the Red Sea, while the locusts usually come to Egypt from the south or southwest . But Denon (quoted by Knobel) describes a locust cloud which he witnessed coming from the east, producing great havoc in Egypt, and then driven back by a west wind, precisely like the one here mentioned .

Niebuhr describes swarms of locusts coming upon Egypt in December and January, and Lepsius and Tischendorf describe them in March, closely corresponding to the time of this narrative as it is fixed by Exodus 9:31-32. After the dreadful destruction by the hail this locust plague must have been fearfully calamitous. This was foreseen by Pharaoh’s counsellors, who looked upon a locust visitation as the destruction of Egypt.