Thundery showers

i. gök gürültülü sağnak yağış

a phrase akin to "wintry showers" which has crept into the language because many forecasts have severe word constraints. If well-developed and 'vigorous' thunderstorms are expected, then the forecast should say so, but when you only have 4 words to play with, some short-hand phraseology is necessary on a showery day with perhaps some scattered 'rumbles' of thunder.