A low pressure system developing in central Italy over the weekend will move into the Balkans through early in the new week.
While the low is expected to bring only a few spotty thunderstorms across Italy on Sunday, heavier rain will set up on the eastern side of the low.
Those from Hungary and Croatia into Serbia and Bosnia and Herzegovina need to prepare for periods of heavy rain into Monday.
The core of heavy rain will then shift southward into Albania, Macedonia, Bulgaria and Greece Monday into Tuesday. By Tuesday, even western Turkey will have some heavier thunderstorms.
"Excessive rainfall from the slow-moving showers and thunderstorms may lead to flooding of low-lying and urban areas," AccuWeather Meteorologist Anthony Sagliani said Friday.
Through Tuesday, rainfall amounts of 20 to 40 mm (0.75 to 1.50 inches) is expected. However, locally higher amounts, reaching up to 75 mm (3 inches) is possible, especially in a heavy thunderstorm.
"Landslides and mudslides would be possible along the slopes of higher terrain," Sagliani added.
The amount of rain moving through the region could hinder any migrants fleeing Syria. Many migrants continuing to take a route through the Balkans towards Hungary or Croatia will be battling the heavy rain. Police and officials at country boarders and assisting these migrants will want to bring along the rain gear.
This storm track is similar to what AccuWeather Meteorologist Eric Leister describes in the Fall European Outlook 2015, released by the AccuWeather Long-Range team in late August.
"While the storm systems will quickly move through Spain and France, some of the storms will slow down and spin over Italy and southern Balkans for several days, which will also lead to a higher flooding threat throughout the fall season." Leister said.
Although another wave of wet weather is possible with a quick-moving storm across Western Europe, the same high pressure that will bring a dry weekend with sunny spells across western Europe will move in behind this system bring at least a brief break from the rain across the Balkans.
Sunny spells are expected from the United Kingdom to Portugal, Spain and France throughout the weekend. This high will move eastward into eastern France Monday, pushing showers in central Europe eastward.
For those heading to the start of Oktoberfest in Germany this weekend, conditions will be rather nice. By the end of the 16-day festival, an estimated 6.4 million people will visit Munich for Oktoberfest celebrations, according to the Munich City Guide's website.
For the first few days of the event, sunshine will be fading in and out of clouds. There will be a spotty shower or two across the country through Sunday and Monday, mainly in the afternoon.