On seeing lightning
בָּרוּךְ אַתָּה יְיָ אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם, עוֹשֶׂה מַעֲשֶׂה בְּרֵאשִׁית:
Baruch Ata Adonai, Eloheinu Melech haolam, oseh ma'aseh vereishit.
Blessed are You, Adonai, our God, King of the universe, who performs the work of creation.
On hearing thunder
בָּרוּךְ אַתָּה יְיָ אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם, שֶׁכֹּחוֹ וּגְבוּרָתוֹ מָלֵא עוֹלָם:
Baruch Ata Adonai, Eloheinu Melech haolam, shekocho ugvurato malei olam.
Blessed are You, Adonai, our God, King of the universe, whose strength and power fill the world.