The most common and most likely answer to this crossword clue is the 5 letter word SIBYL
I've seen this crossword clue in Financial Times
S
I
B
Y
L
More clues leading to the result SIBYL
- Forecaster succeeded by cutting Italian article
- Prophetess lives over by lake
- Forecaster is upset over Times line
- Forecaster is backing Times line
- Forecaster is over beside lake
- Oracle is upset near the top side of lake
- Fortune-teller is back with Bill, we’re told
- Misses faulty-sounding prophetess?
- Fortune-teller is coming back via Luxembourg
- Female seer admitted by holy bishop in retreat
Buddy explains!

The straight part
We know that "Forecaster" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case forecaster = sibyl.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 SIBYL mean?
SIBYL noun- A pagan female oracle or prophetess, especially the Cumaean sibyl.