Reference : Hisn al-Muslim 166

اللّهُـمَّ إِنَّـي أَسْـأَلُـكَ خَيْـرَها، 
وَأَعـوذُ بِكَ مِنْ شَـرِّها
Allāhumma innī as'aluka khayrahā, 
wa a`ūdhu bika min sharrihā.


O Allah, I ask You for the good of it, 
and seek refuge in You against its evil.

Reference:
Abu Dawud 4/326, Ibn Majah 2/1228. See also Al-Albani, Sahih Ibn Majah 
2/305.

Chapter: During a wind storm