On May 10, Bulgaria will see mostly cloudy skies with occasional clear spells in the western regions. The south and east will experience significant rainfall throughout the day, with thunderstorms anticipated in the afternoon, particularly in the extreme southwest and southeast as well as in mountainous areas. The southern parts are expected to receive substantial rainfall amounts. Winds will blow from the east-northeast at moderate speeds. Temperatures will range from 14°C to 19°C in most areas, 12°C to 14°C in the northeast, and around 15°C in Sofia.

Along the coast, the weather will remain overcast and rainy, with heavy rainfall and thunderstorms expected in the southern stretches of the coastline. Winds will maintain a moderate east-northeasterly direction, with daytime temperatures ranging between 12°C and 14°C. Sea temperatures will be slightly warmer, hovering around 15°C to 16°C, with waves reaching 2 to 3 degrees on the Douglas scale.

In the mountains, cloudy conditions will persist, with rain falling below 2,000 meters and snow at higher altitudes. Afternoon thunderstorms are anticipated, accompanied by light to moderate north-northeasterly winds, with mountaintops experiencing moderate westerly gusts. Maximum temperatures will reach 11°C at 1,200 meters and 4°C at 2,000 meters.

On May 11, isolated areas will experience reduced visibility in the morning. By noon, cumulus clouds will develop, bringing brief rain showers in the mountains and possibly some thunder. The Danubian Plain will see northwesterly winds picking up to moderate speeds, but precipitation is less likely there. Morning lows will range from 5°C to 10°C, while daytime highs will reach between 16°C and 21°C.