The phrase "a sure indication of" is correct and usable in written English.
It can be used to express that something clearly signifies or points to a particular conclusion or outcome.
Example: "The sudden drop in temperature is a sure indication of the approaching storm."
Alternatives: "a clear sign of" or "a definite signal of".
But that finding wasn't a sure indication of clouds on the planet.
This curious juxtaposition is a sure indication of very muddled thinking.
This is a sure indication of the government's continuing failure to place enough emphasis on the voluntary sector.
A sure indication of stepping back, this official said, was the low-key approach since Secretary Powell returned from Israel last Saturday.
The strength of the story was a sure indication of the emotional chords it struck, illuminating the darkness of our fears and fascinations about video surveillance.
In this unstable atmosphere the air moves freely up and down, following the adiabatic lapse rate, so that the atmospheric lapse rate continually adjusts to G; unstable lapse rates are almost never actually observed in the atmosphere except in the lowest few meters above the surface, and the observation of an adiabatic lapse rate is in fact a sure indication of an unstable atmosphere.
Another is Los Machos Beach, where we found a stray terrier-mix puppy, less than ten pounds, with mangy-looking fur, some scabs and cuts, skinny but with a distended belly -- a pretty sure indication of intestinal worms.
Runs came off his legs, an area that had been barren in previous innings and a sure indication in a change of line from the bowlers.
While this is not always a sure indication, either, if the peel of a mango has developed a few brown spots or speckles, it is likely ripe.
There's no guarantee the features will ever be enabled, but the presence of the code is a sure indication that the new options are being considered.
