Back 
Surah 41. Fussilat
Ayah 15 - 16
15فَأَمَّا عَادٌ فَٱسْتَكْبَرُوا۟ فِى ٱلْأَرْضِ بِغَيْرِ ٱلْحَقِّ وَقَالُوا۟ مَنْ أَشَدُّ مِنَّا قُوَّةً ۖ أَوَلَمْ يَرَوْا۟ أَنَّ ٱللَّهَ ٱلَّذِى خَلَقَهُمْ هُوَ أَشَدُّ مِنْهُمْ قُوَّةً ۖ وَكَانُوا۟ بِـَٔايَـٰتِنَا يَجْحَدُونَ
16فَأَرْسَلْنَا عَلَيْهِمْ رِيحًا صَرْصَرًا فِىٓ أَيَّامٍ نَّحِسَاتٍ لِّنُذِيقَهُمْ عَذَابَ ٱلْخِزْىِ فِى ٱلْحَيَوٰةِ ٱلدُّنْيَا ۖ وَلَعَذَابُ ٱلْـَٔاخِرَةِ أَخْزَىٰ ۖ وَهُمْ لَا يُنصَرُونَ
[15-16] As for the 'Ad, they became arrogant with pride in the land without any right, and said, "Who is stronger than us in might?" Did they not see that God, Who had created them, is stronger than they in might? Yet they continued to deny Our Revelations. Consequently, We sent upon them a stormy wind over a few ill-omened days20 so that We might make them taste a disgraceful scourge in the life of this world,21 but the scourge of the Hereafter is even more disgraceful; there they shall have none to help them.
20"Ill-omened days" does not mean that the days in themselves were ill omened, and the torrent came because the people of Ad met with those ill omened days. If this were the meaning and there were some ill omen in the days themselves, the torment would have visited all the nations of the world. The cornet meaning, therefore, is that since in those days God's torment descended on this nation, the days were ill-omened for the people of 'Ad. It is not cornet to argue on the basis of the verse that some days are ill-omened and some auspicious.
The lexicographers have disputed the meaning of the words rih-an sarsaran, which have been used for the stormy wind. Some say that they imply an intensely hot wind; others say that they imply an extremely cold wind; and some others say that they imply a wind which produces a great noise when it blows. In any cast, they All agree that the words are used for a severe storm.
The details of this torment given at other places in the Qur'an show that this wind continued to rage for seven nights and eight days consecutively. It swept the people off the ground and they fell down dead and lay scattered here and there like hollow trunks of the palm-tree. (AI-Haaqqah: 7). It left rotting everything on which it blew. (Adh-Dhariyat 42). When the people of 'Ad saw it advancing, they rejoiced with the hope that the dense clouds would bring much rain, which would water their withering crops. But when it came it laid waste the entire land." (Al-Ahqaf: 24-25).
21This ignominious torment was an answer to their arrogance and vanity because of which they had assumed greatness in the land without any right, and would boast that there was none more powerful than they on the entire earth. Allah disgraced them and destroyed the major part of their population along with their civilization. The remnant of their population was humbled and debased before those very nations whom they used to overawe by their show of power and might (for the details of the story of 'Ad see AI-A'raf : 65-72; Hud: 50-60; Al Mu'minun: 32-41; Ash-Shua'ra' : 123-140; AI-'Ankabut; 40 and the relevant E.N.'s).