"converging upon" is a correct and usable phrase in written English.
It means to move towards a common point or goal from different directions. You can use it when describing a situation where different ideas or thoughts are coming together to form a unified concept or conclusion. Example: The group of scientists were converging upon a solution to the complex equation, each contributing their own expertise and knowledge.
I suppose that people are converging upon Hay from all directions, since thousands are expected, but how are those from London getting there?
After the bitter political warfare of 2010, that is a deal Republicans and Democratic politicians appear to be now converging upon.
If it had been successful, the suit would have facilitated poll watchers from across the state converging upon areas where they suspect, with little evidence, that election fraud may take place.
The computer models forecasting the track of Hurricane Sandy over the next three days are converging upon a landing around southern New Jersey that could create record coastal flooding and a big enough storm surge that state and local officials have ordered mandatory and voluntary evacuations along the coast from Delaware to Connecticut.
A new method is introduced to analyze both the residual stress distribution in a film near its edge and the energy release rate and mode mix for an interface delamination crack emerging from, or converging upon, an edge.
The inner sense for Augustine makes us aware that the disparate information converging upon us from our various senses comes from a common external source (e.g., the smell and taste belong to the same object one is looking at while holding it in one's hand).
Such an intolerably vivid reality converges upon Franco, too.
Even when the bikes and cars seem poised to converge upon you, they won't.
I have laid a fly on the water and seen three wakes converge upon it.
As the parade progressed through central Belgrade, a crowd of 2,000 protesters converged upon it.
Clinton told his driver to pull over, and he allowed the crowds to converge upon him.
