The phrase "a notably good" is correct and usable in written English.
It can be used to emphasize the quality of something that stands out as particularly good or impressive.
Example: "The restaurant received a review that praised it as a notably good place for family gatherings."
Alternatives: "an exceptionally good" or "a remarkably good".
Her selection is a notably good decision by Orange.
The 1815 port vintage, a notably good one, was christened the Waterloo vintage.
Indeed, the Social Democrats' candidate for the chancellorship, Gerhard Schröder, has been getting a notably good hearing in France.
He told me that Sheikh Mohammed was a keen sportsman, and a notably good horseman, and that his eldest son, Rashid, was a committed football fan.
As noted here before, British Guyanans, their parents raised in a notably good school system, have been conspicuously high-achieving in British society – up to cabinet rank.
Owned by a French couple, the Gate House also has a notably good restaurant (with an excellent wine cellar) for an island with just 1,500 residents.
Twenty-eight winners in five categories were announced in a notably good-natured, fast-paced evening presented by the workshop in association with the Danspace Project and the Joyce Theater.
The nurses were all notably good-looking, and Xu confided that she'd had several procedures.
(Headroom is notably good for such a low-riding machine).
The Hollywood Farmers Market, which is among the biggest, stands out, with notably good produce and a good location for spotting celebrities buying vegetables.
Weinstein released a series of highly successful films most notably Good Will Hunting (1997), Shakespeare in Love (1998; Academy Award for best picture), and The Cider House Rules (1999)—and by the late 1990s his movies had garnered nearly 40 Oscars.
