Question: The Qur'an speaks in various passages about the people of Aad, and about their destruction by terrible tornado as punishment from Allah for their disobedience.
The Qur'an, however, contradicts itself in the number of days this wind endured.
"Lo! We let loose on them a raging wind on a day of constant calamity," [54:19]
"therefore We let loose on them a raging wind in evil days, that We might make them taste the torment of disgrace in the life of the world. And verily the doom of the Hereafter will be more shameful, and they will not be helped." [41:16]
"And as for A'ad, they were destroyed by a fierce roaring wind, Which He imposed on them for seven long nights and eight long days so that thou mightest have seen men lying overthrown, as they were hollow trunks of palm-trees." [69:6-7]
According to Sura 54:19, the wind continued for a single day, while 41:16 uses the plural form indicating at least three days, and 69:7 specifies exactly eight days.
Answer: That is an easy one. If you follow the hurricanes news you find people put it in three stages:
stage 1: The day we discover the hurricane (or God send it)
54:19 For We sent against them a furious wind, on a Day of violent Disaster, إِنَّا أَرْسَلْنَا عَلَيْهِمْ رِيحًا صَرْصَرًا فِي يَوْمِ نَحْسٍ مُّسْتَمِرٍّ
Stage 2: The days the winds gather more force (sent in the verse) or less before it strikes (usually in oceans):
41:16 So We sent against them a furious Wind through days of disaster, that We might give them a taste of a Penalty of humiliation in this life; but the Penalty of a Hereafter will be more humiliating still: and they will find no help.
فَأَرْسَلْنَا عَلَيْهِمْ رِيحًا صَرْصَرًا فِي أَيَّامٍ نَّحِسَاتٍ لِّنُذِيقَهُمْ عَذَابَ الْخِزْيِ فِي الْحَيَاةِ الدُّنْيَا وَلَعَذَابُ الْآخِرَةِ أَخْزَى وَهُمْ لَا يُنصَرُونَ
Stage 3: the days of destruction:
69:6 And the 'Ad, they were destroyed by a furious Wind, exceedingly violent; وَأَمَّا عَادٌ فَأُهْلِكُوا بِرِيحٍ صَرْصَرٍ عَاتِيَةٍ
69:7 He made it rage against them seven nights and eight days in succession: so that thou couldst see the (whole) people lying prostrate in its (path), as they had been roots of hollow palm-trees tumbled down! سَخَّرَهَا عَلَيْهِمْ سَبْعَ لَيَالٍ وَثَمَانِيَةَ أَيَّامٍ حُسُومًا فَتَرَى الْقَوْمَ فِيهَا صَرْعَى كَأَنَّهُمْ أَعْجَازُ نَخْلٍ خَاوِيَةٍ
