Lack forerunner of lengthy winter in New York? (9)

I believe the answer is:

shortfall

'lack' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for shortfall that I've seen before include "Deficit of something required" , "what we're lacking" , "lack" , "Not enough money" , "Deficiency" .)

I've seen this clue in The Guardian.

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