The phrase "and flowing in a" is correct and usable in written English.
It can be used in contexts where you are describing something that is moving smoothly or continuously, often in relation to liquids or abstract concepts like ideas or emotions.
Example: "The river was wide and flowing in a gentle curve through the valley."
Alternatives: "and moving in a" or "and streaming in a".
Grand River, river rising near Creston, Union county, south-central Iowa, U.S., and flowing in a southerly direction into Missouri.
Heavy cream has enough fat to coat the proteins, keeping them separate and flowing in a smooth, creamy liquid, but skim milk does not.
Konkouré River, river, rising in the Fouta Djallon plateau of west central Guinea, West Africa, and flowing in a westerly direction to the Atlantic just north of Sangareya Bay.
Paranapanema River, Portuguese Rio Paranapanema, river, rising south of São Paulo in the Serra do Paranapiacaba, southeastern Brazil, and flowing in a west-northwesterly direction for 560 mi (900 km) before entering the Paraná River at Pôrto São José.
Rivers disappear and resurface in this Everglades of the North, the tannin-stained water seeping and flowing in a gigantic aquifer alive and burping, its deep sphagnum sponge spouting methane into clear Northern air.
The words came loose as though liquid and, flowing in a single gush, came to rest on my lips as at the source of a garden as old as several years of drought.
He says that it helps him pinpoint the precise ebbs and flows in a game: a run by a team, a hot streak for a player.
Time ebbs and flows in a sluggish tide; characters dissolve into one another; events occur, retreat and reappear in different guises.
The Nanpan drops about 5,900 feet (1,800 metres) in the first 530 miles (850 km) of its course and flows in a southeasterly direction through Yunnan province.
During much of its upper and middle course, the Cuanza is broken at intervals by rapids and flows in a well-defined valley.
The San Juan River, at Lake Navajo, forms the county's northeastern boundary, then receives the Las Animas River and flows in a long curve through the county.
