In the middle of the week, a "significant change in the weather" is expected when a "cold atmospheric front" passes over the country. It will bring "strengthening winds," a "drop in temperatures," and "rainfall," which will be more intense in some places and accompanied by thunderstorms.
Until the arrival of the front, the weather will remain relatively calm – with "broken clouds" and temporary decreases in precipitation at night. In the morning hours, "fog" will form in some low-lying areas, and during the day there will be more "sunny hours," creating the feeling of typical early summer.
In the afternoon, the situation will "destabilize": in "mountainous regions" and in "Northeastern Bulgaria," "cumulonimbus clouds" will develop with brief showers and thunder. Temperatures will remain at "summer values," but the trend will now be toward a gradual decline.
Along the "Black Sea coast," mornings will be mostly sunny, with a temporary increase in cloudiness in the afternoon. "Light rain" is possible on the northern coast, but overall the sea will remain "calm," and conditions will be suitable for walks and the beach with attention to afternoon developments.
In the "mountains," the day will start with sunny weather, but by around noon instability will develop with "local rainfall" and "thunderstorm activity," mainly in the "Rila-Rhodope region" and the western parts of the "Stara Planina." Tourists should plan early treks and avoid higher elevations in the afternoon.
A more significant change is expected on "Friday," when the cold front will cover most of the country. Then the "wind will strengthen" and the "rainfall and thunderstorms" will become more intense. In some places, "significant amounts of rain" are expected in a short time, with a risk of local flooding.
Temperatures will "drop noticeably," especially in the "western part" of the country, where daytime values will approach around "20 degrees." It will remain warmer in the "southeastern regions" – up to about "29–30 degrees," which will maintain a contrast between different parts of the country.
During the "weekend," the rainy conditions will gradually weaken, but the weather will remain "cooler for mid-June." Daytime temperatures will mostly range between "21 and 26 degrees," and the feeling of climatic instability will remain – with fresher mornings and cooler evenings.
Meteorologists remind that such cold fronts at the beginning of summer are typical for the region and urge "increased caution" during travel, outdoor work, and mountain hikes – especially on Friday and in areas with expected more intense storms.