This is the 11191st most frequent Russian word.
грозами
"Грозами" means "with thunderstorms" or "by thunderstorms" (instrumental plural of "гроза").
In this sentence, 'грозами' is instrumental plural, indicating something accompanied or caused by thunderstorms—figurative imagery.
Летний пейзаж загрохотал грозами, приносившими облегчение от жары.
The summer landscape rumbled with thunderstorms, bringing relief from the heat.
Here, 'грозами' again serves as an instrumental plural, describing a state of being surrounded or associated with thunderstorms.
Деревня была окружена грозами в течение всей ночи.
The village was surrounded by thunderstorms throughout the night.
In this context, 'грозами' qualifies the interest focus, being instrumental plural related to thunderstorms as a subject of study.