This seems to be a declarative sentence. It talks about the reaction of the policeman to a specific thing. His expression is not pleasant. What he might saw is something not good and something to worry about. Other possible thing could be there an heinous crime scene that he faced at that moment. It depends on the situation.<span />
Montag was afraid that Captain Beatty would discover the book he stole from the old lady
Answer:
The weather has been nice but, it may snow again any day.