"narrow enough that" is correct and usable in written English.
You can use it when referring to an object or concept being small but not too small. For example, "The opening was just narrow enough that I could squeeze through it."
Even most two-way streets are narrow enough that cars can park only on one side.
"For lower-risk patients, the benefits are narrow enough that they may opt against it," he said.
Bauman's mother, his girlfriend and a few others gathered to watch in a hallway narrow enough that Bauman could reach the railings on each wall.
Will it be enough so that news shows say the GOP is at fault, or narrow enough that they'll say people blame both sides?
It is true that in one or two states, such as Colorado and New Hampshire, Obama's lead is narrow enough that it could be a statistical fluke.
Several said the decision was narrow enough that it was more unlikely now that the Supreme Court, if it accepted the case, would use it to establish a constitutional right to same-sex marriage.
The hole has not changed much, although Pavin said the fairway had been narrowed enough that he believed his second shot from the 18th fairway nine years ago would now be in the first cut of rough.
This study also assumes that the channel is narrow enough so that no frequency selective fading occurs, and that the average power of each substream prior to power control is identical.
It is assumed that the ducts are narrow enough so that the flow is hydrodynamically and thermally fully developed.
However, Schneiderman said Jan . 27that the liability releases in the draft settlement had become narrow enough so that a full investigation by a new mortgage crisis unit that he will help lead could move forward.
For photovoltaic cells, the optimum bandgap for the solar cell material is a compromise between a bandgap wide enough so that not too many electrons are wasted and yet narrow enough so that enough photons can be absorbed to create electron hole pairs[1].
