The most common and most likely answer to this crossword clue is the 9 letter word PROGNOSIS
I've seen this crossword clue in The Daily Telegraph
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More clues leading to the result PROGNOSIS
- Circulating air is linked to expert forecast
- Lied maybe about first of inaccuracies in expert’s medical prediction?
- Forecast of programme numbers is to follow
- Professional revealed spiritual knowledge in forecast
- Stormy signs and poor outlook
- Poor signs perhaps for medical forecast
- Air rising is observed after expert forecast
- Outlook for good little relative — no being hugged!
- Forecast for islands — westerly air coming in
- TV show is following numbers in forecast
Buddy explains!

The straight part
We know that "medical forecast" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case medical forecast = prognosis.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PROGNOSIS mean?
PROGNOSIS noun- A forecast of the future course of a disease or disorder, based on medical knowledge.
- The chances of recovery from a disease.
- A forecast of the future course, or outcome, of a situation; a prediction.